JPH06333240A - Optical information recording member and recording/ reproducing device - Google Patents

Abstract

(57) [Summary] [Object] To provide a recording member and a recording / reproducing apparatus provided with a guide groove having a high track density, and address information. An optical recording member for recording an information signal by irradiating light on a substrate 5 provided with an uneven guide groove having a high track density, and a part of the guide groove on the grooves G2, G3, G4 is intermittently formed. Address information is thereby formed, and the recording position of the address information is provided in different zones X and Y in the track direction between adjacent tracks, and the address signal is generated by the reflectance change when the light beam 1 is passed over the land portion. Detecting and simultaneously recording or reproducing the information signal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information recording member capable of recording and reproducing information by using a light beam, and more particularly to a recording member capable of obtaining a high track density and a recording / reproducing apparatus thereof.

[0002]

2. Description of the Related Art Conventionally, an optical disk, an optical card, or an optical tape has been known as a medium capable of optically recording or reproducing information. Most of these recording media (recording members) use a system in which information is recorded by irradiating a recording thin film included in the medium with a laser beam that is finely focused through a lens. Among them, the optical disk has a circular substrate having spirally or concentrically formed guide grooves having irregularities, and a recording thin film formed thereon. In this optical disc, recording and reproducing of information is performed by irradiating a laser beam along the guide groove.

A conventional optical disk will be described with reference to FIGS. 17 and 18. Record the signal on the recording member,
Alternatively, in order to reproduce, it is necessary to first search the recordable area of the recording member or obtain the management information indicating the recording position of the intended information signal. For this reason, an address area for managing an information area for recording information is provided on the optical disk at regular intervals of the disk. There are two types of forms of the address area, that is, a form in which the information signal is recorded on the convex surface of the guide groove and a form in which the information signal is recorded on the concave surface. Here, with respect to the incident direction of the light beam, recording on the convex surface of the guide groove is referred to as groove recording, and conversely, recording on the concave surface is referred to as land recording. 17 and 18 show the configurations of representative examples of the respective forms.

FIG. 17A shows an example in which the vicinity of the address area of a recording member used for groove recording is enlarged. (B) shows the AA cross section in (a), (c) shows the BB cross section of the recording track center part of (a). As shown in FIG. 17A, the recording member includes an address area 2 and an information area 3.
Have and. The address area 2 is formed on the information track in a portion separated from the information area 3. FIG. 17 (b)
As can be seen from (c) and (c), the address area 2 and the information area 3 respectively have a groove 141 which is a convex surface and a land 14 which is a concave surface with respect to the incident direction of the light beam 1.
2 has a concavo-convex structure. The recording mark 7 corresponding to the information signal to be recorded is the groove 141 of the information area 3.
Formed on. Address pit 1 which is an address signal
The groove 43 is formed in the address area 2 with the groove 141 intermittently formed.

FIG. 18A shows an example in which the vicinity of the address area of a recording member used for land recording is enlarged. (B) shows the AA cross section in (a), (c) shows the BB cross section of the center part of the recording track of (a). This recording member is also separated into an address area 2 and an information area 3.
Each of the regions 2 and 3 has a concavo-convex structure including a groove 151 that is a convex surface and a land 152 that is a concave surface in the incident direction of the light beam 1. In this case, the recording mark 153 is formed on the land 152 of the concave portion with respect to the laser beam 1. The address pit 154 is
In the address area 2, it is formed as an uneven shape on the same track as the track on which the recording mark 153 is formed.

As shown in FIGS. 17 and 18, address pits 143 and 154 are formed on the center line of a track for recording an information signal in both land recording and groove recording. The demodulation of the information signal is performed by demodulating the change in the reflected light amount due to the uneven pits as address information and specifying the recording position of the information signal on the optical disc. As a result, it is possible to record / reproduce the information signal at the predetermined position.

A method of manufacturing a substrate having address pits indicating the address signal will be described with reference to FIG.
FIG. 19A is a flowchart showing the manufacturing process,
(B) is a schematic diagram showing each step in the case of producing a recording member for groove recording, and (c) is a schematic diagram showing a step of producing a recording member for land recording, showing steps different from those in the case of groove recording It is a figure. The manufacturing process includes a mastering process for making a master having a shape opposite to that of the required substrate and a duplication process for molding a substrate based on the obtained master.

The mastering process will be described. First, the photoresist 162 is applied on the glass flat plate 161, and the photoresist 162 is spirally exposed by irradiating the Ar laser beam 163 while rotating the glass flat plate 161. In the case of the recording member for groove recording shown in FIG. 17, by irradiating a single Ar laser beam 163 with a constant power as shown in FIG.
A guide groove in the information recording area is formed. In the address area, the area corresponding to the address is exposed by modulating the laser power according to a predetermined pattern. In the case of the land recording member, as shown in FIG. 19 (c), it is shifted by 1/2 of the track pitch in the tracking direction.
Two laser beams 164 and 165 are used. A groove for tracking is formed by the first laser beam 164, and an address pit is formed by modulating the second laser beam 165 with a predetermined pattern, thereby recording an address signal. Next, the exposed portions 166, 16 are subjected to a developing process.
7 and 168 are removed, and nickel 169 is added according to the plating process.
Are formed on the surface. Finally, the nickel 169 is peeled off from the glass substrate 161, so that the master 170 having an uneven structure on the surface is obtained.

The duplication process will be described. There are various methods depending on the material of the substrate that constitutes the recording member, but from the viewpoint of high mass productivity, the manufacturing process of the optical disc is
The injection molding method is mainly used. In the injection molding method, the master 170 obtained in the mastering step is mounted on the mold 171 in the injection molding machine, and the resin material 172 is injected to obtain the resin substrate 173 having the predetermined concave and convex grooves. By forming the recording thin film on the resin substrate 173, an optical disk which is a recordable recording member can be obtained.

[0010]

As described above, the address area which is the management information of the optically recordable and reproducible recording member can be formed. However, considering that these optical discs are widely used for recording a large amount of data or image information, it is necessary to further increase the recording density. As a method for increasing the recording density, it is conceivable to shorten the wavelength of the irradiation light or increase the numerical aperture of the lens that condenses the light. By using this method, the spot of condensed light can be made small, so that it is possible to make the track pitch as well as the density in the track direction at the time of recording. The track pitch Tp of the present optical disk is 1.6 μm, the width of the guide groove is about ½ of that, and the depth is a value near 500 nm. However, in order to cope with the high density, it is necessary to reduce the diameter of the spot to be focused and the track pitch accordingly. However, for example, 1.
The following problems arise when attempting to achieve a value in the vicinity of 0 μm or less.

It is possible to manufacture a master having a track pitch of 1.0 μm or less by the above-mentioned mastering process. It is also possible to further increase the density by shortening the wavelength of the photoresist and the laser light for exposing it. When the track pitch of the guide groove is small, the shape required for the substrate from the viewpoint of recording characteristics is that the width of the portion where the recording mark is formed is as large as possible in order to secure the signal amplitude. Therefore, the structure is such that the groove width is kept wide in the case of the groove recording substrate and the land width is kept wide in the case of the land recording substrate. However, in injection molding, it becomes difficult to maintain good transferability as the track pitch becomes smaller. The transferability indicates the degree of reproducibility of the surface shape of the master and the surface shape of the resin substrate obtained as a result of injection molding. Injection molding
The molten resin is poured onto the surface of the mold, and the shape of the master is transferred by the pressure of injection. For this reason, if the width of the portion where the resin is pushed into the master, that is, the width of the land, becomes smaller, the transferability becomes worse.

The problem when the track pitch is reduced will be described with reference to the sectional view of the injection molding machine shown in FIG. Here, an example of a groove recording substrate is shown. As shown in the figure, the land between the grooves, that is, the narrow groove 17 on the master.
4 must be filled with resin. However, if the track pitch Tp is reduced while maintaining the groove width Gw for the above-mentioned reason, there is a problem that a large facility having a very high injection pressure is required to fill the resin.

Similarly, in the land recording compatible substrate, when the track pitch becomes small, the width of the land regions 155 on both sides of the address pit shown in FIG. 18 becomes extremely small, which makes injection molding difficult.

The present invention has been made in view of the above problems of the prior art, and has a guide groove having a high track density,
An object of the present invention is to provide a recording member and a recording / reproducing device provided with address information.

[0015]

The optical information recording member of the present invention has on its surface a track on an uneven surface composed of a first surface and a second surface having different optical positions with respect to the incident direction of a light beam. A recording member having a recording thin film layer that causes a change that can be optically detected by light irradiation on a substrate, wherein the track has an information recording area in the track direction and an address area having management information of the information recording area. The address area is formed of an address pit row formed by isolating a part of the track formed of the first surface according to a predetermined code signal, and the information recording area is formed on at least the guide track formed of the second surface. Is used as an information recording area, and thereby the above-mentioned object is achieved.

In addition, the optical information recording member of the present invention is designed such that an optical track is formed on a substrate having on its surface a track on an uneven surface composed of a first surface and a second surface having different optical positions with respect to the incident direction of the light beam. Is a recording member provided with a recording thin film layer that causes a change that can be optically detected by the irradiation of, and the track has an information recording area in the track direction and an address area having management information of the information recording area, The address area is composed of an address pit row formed by isolating a part of the track formed of the first surface according to a predetermined code signal, and the track pitch of the track formed of the first surface is 1.2 μm.
And the width of the track formed of the first surface is smaller than the width of the track formed of the second surface,
Thereby, the above object is achieved.

The address area may be composed of at least two zones adjacent to each other in the track direction, and the track composed of the first surface may be provided with an address pit row in at least one of the zones.

The track formed of the first surface adjacent to both sides of the track of the address pit row in the vertical direction may have a continuous shape.

In a zone where tracks on the first surface have a continuous shape, and a track vertically adjacent to the track has address pits, the width of the track on the first surface is the information. It may be smaller than the width in the region.

In a zone where tracks on the first surface have a continuous shape and a track vertically adjacent to the track has address pits, the width of the address pits is larger than the width in the information area. May also be increased.

The track on the first surface having the address pit may be convex in the incident direction of the light beam.

An address start zone indicating the start point of address information may be provided at the beginning of the address area, and the start zones may have the same pattern between adjacent tracks.

Further, the optical information recording member of the present invention has a structure in which light is recorded on a substrate having on the surface thereof a track on an uneven surface composed of a first surface and a second surface having different optical positions with respect to the incident direction of the light beam. A recording member provided with a recording thin film layer that causes a change that can be optically detected by irradiation, wherein the track has an information recording area in the track direction and an address area having management information of the information recording area. The area is composed of an address pit row formed by isolating a part of the track formed of the first surface according to a predetermined code signal, and the address area has at least two zones which are adjacent to each other in the track direction. Has the same pattern of address pits in at least one zone on the track consisting of the first surface as the adjacent tracks on the first surface. Serial object is achieved.

The address area has three zones,
In the zone having the address pits of the track formed of the first surface, one track of the adjacent tracks may have the address pits of the same pattern, and the other track may have a continuous shape.

In a zone where tracks on the first surface have a continuous shape and a track vertically adjacent to the track has address pits, the width of the track on the first surface is the information. It may be smaller than the width in the region.

In the zone in which the zones on the track formed by the first surface are continuous and the tracks vertically adjacent to the track have address pits, the width of the address pits is larger than the width in the information area. May be larger.

The address area has two zones,
Both tracks may have address pits in both zones.

The optical information recording member of the present invention has the first surface and the second surface which are different in optical position with respect to the incident direction of the light beam.
A recording thin film layer that produces a change that can be optically detected by irradiation of light is provided on a substrate having a track on the surface of which unevenness is formed, and both the first surface and the second surface of the track are recorded with information. A recording member serving as a recording area, the track including an information recording area and an address area having management information of the information recording area in a track direction, and the track width of the first surface and the track of the second surface. Has a width substantially equal to that of the first area, and the address area is composed of an address pit row formed by isolating a part of the track formed of the first surface in accordance with a predetermined code signal. It

The address area has at least two zones adjacent to each other in the track direction, and the track formed of the first surface has address pit rows in at least one zone, and the zones having the address pit rows have both sides. The track formed of the first surface adjacent to may have a continuous shape.

In the zone in which the tracks on the first surface have a continuous shape, and the tracks vertically adjacent to the track have address pits, the width of the tracks on the first surface is the information. It may be smaller than the width in the region.

In the zone in which the tracks on the first surface have a continuous shape, and the tracks vertically adjacent to the tracks have address pits, the width of the address pits is larger than the width in the information area. May be larger.

The address area has at least two zones adjacent to each other in the track direction, and the address area is
The pattern of the address pits of at least one zone on the track formed of the first surface may be the same as that of the adjacent track of the first surface.

The address area has three zones,
In the zone having the address pits of the track formed of the first surface, one track of the adjacent tracks may have the address pits of the same pattern, and the other track may have a continuous shape.

The address area has two zones,
Both tracks may have address pits in both zones.

An address start zone indicating the start point of address information may be provided at the beginning of the address area, and the start zone may have the same pattern between adjacent tracks.

The optical information recording / reproducing apparatus of the present invention irradiates light onto a substrate having on its surface a track on an uneven surface composed of a first surface and a second surface having different optical positions with respect to the incident direction of the light beam. A recording member provided with a recording thin film layer that causes a change that can be optically detected by the track, the track having an information recording area in the track direction and an address area having management information of the information recording area. Is the first
A device for recording / reproducing an information signal by irradiating a recording member composed of an address pit row formed by isolating a part of a track formed by a surface according to a predetermined code signal, the recording member being formed on the recording member. Light detecting means for detecting the reflected light of the light beam applied to the light beam, and the light beam on the second surface between the first surface provided with the address pit row from the output signal of the light detecting means. A tracking means for following the signal, and an address demodulating means for demodulating the pattern of the address pit string formed in the address area by comparing the output signal of the photodetecting means with a predetermined reference voltage. Therefore, the above object is achieved.

The demodulation means for demodulating the address signal synchronizes the gate signal with the gate reproduction means for generating a gate signal having a plurality of address reproduction gates having a fixed time width. The gate adjusting means and the gate selecting means for selecting a specific gate by comparing the detection level or the error rate of the address signal included in the synchronized gate signal among the plurality of gates. The address information may be specified from the demodulated signal between the selected gates.

The recording member is provided at the beginning of the address area, has the same pattern between adjacent tracks, and has an address start zone indicating the start point of address information. The device has an address start zone recognition means for specifying the address area start zone from the output signal of the light detection means, and has a fixed time width after a fixed time delay from the output signal from the address start zone recognition means. A gate generating unit for generating a gate pulse may be further provided, and the demodulating unit may be configured to demodulate a signal change occurring within the gate pulse period.

The optical information recording / reproducing apparatus of the present invention is
A recording thin film layer that causes a change that can be optically detected by irradiation of light on a substrate having an uneven track formed of a first surface and a second surface having different optical positions with respect to the incident direction of a light beam on the surface. A recording member having an information recording area in the track direction and an address area having management information of the information recording area, and the address area defines a part of the track formed of the first surface. Is a device for recording / reproducing an information signal by irradiating a light beam on a recording member consisting of an address pit row formed independently according to the code signal of the above, the reflected light of the light beam irradiated on the recording member. For detecting the light, the light detecting means divided in the vertical direction of the track, the tracking means for causing the light beam to follow the second surface according to the output signal of the light detecting means, and the light detecting means. Adding means for obtaining the output sum of the output means, differential means for obtaining the output difference of the light detecting means, absolute value means for obtaining the absolute value signal of the output signal of the differential means, and the absolute value An address demodulation means for demodulating address information by comparing the output signal of the means with a first reference level, and a differential signal between the output signal of the adding means and the output signal of the absolute value means is a second reference level. And an information demodulation means for demodulating an information signal formed on the recording thin film by comparison with the above.

Further, the optical information recording / reproducing apparatus of the present invention is
A recording thin film layer that causes a change that can be optically detected by irradiation of light on a substrate having an uneven track formed of a first surface and a second surface having different optical positions with respect to the incident direction of a light beam on the surface. A recording member having an information recording area in the track direction and an address area having management information of the information recording area, and the track width of the first surface and the track width of the second surface. Are substantially equal to each other, and the address area is composed of an address pit row formed by isolating a part of a track composed of the first surface in accordance with a predetermined code signal, and both the first surface and the second surface of the track are formed. A device for recording / reproducing an information signal by irradiating a light beam on a recording member having an information recording area, wherein an optical system for irradiating the light beam on the recording member, Recording material Tracking error detecting means for detecting the amount of deviation between the track on the recording member and the light beam based on the reflected light or the transmitted light of the recording member, and the light beam is detected by the output signal from the tracking control means. Tracking control means for moving the light beam so as to scan over the track, and for inverting the polarity of the tracking control means depending on whether the tracking is performed on the first surface or the second surface of the track. Tracking inversion means, a signal level comparison means whose reference level changes in at least two stages according to the inversion polarity of the tracking means, and a demodulation means for specifying address information by demodulating the signal from the signal level comparison means. And the above-mentioned object is achieved thereby.

[0041]

In the optical information recording member of the present invention, the information recording area for recording the information signal and the address area for recording the address information have different optical positions with respect to the incident direction of the light beam. The address signal is demodulated while keeping the width of the track on which information is recorded large, even when the track pitch is made small, because the tracks are formed on different surfaces of the two concavo-convex tracks. be able to.

The optical information recording / reproducing apparatus of the present invention is
An address signal and an information signal can be demodulated from the information member having the above configuration.

[0043]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1A is an enlarged plan view of an address area of an optical information recording member of the present invention, and FIG.
3 is a cross-sectional view of the address area of FIG. (C)
Shows a reproduced signal waveform obtained when the light beam 1 passes on the track T2 shown in (a), and a signal waveform when binarized.

The surface of the substrate 5 which is optically transparent to the wavelength of the light beam 1 for recording or reproducing an information signal is provided with a guide groove formed of irregularities having planes whose positions are different from each other in the incident direction of the light beam 1. It has a different configuration. The shapes of the grooves G1 to G4 forming the unevenness shown here are the same as those of the substrate used for the conventional groove recording. The recording member has an address area 2 and an information area 3. The address area 2 is provided at regular intervals so that the amount of information that can be recorded in the information area therebetween is constant. The address area 2 is composed of a zone X and a zone Y. The address pits 4 are formed by intermittently forming grooves in a zone having different track-direction positions between adjacent tracks in a pattern according to a predetermined code signal. The groove G1 and G3 are provided with an address pattern in the area of the zone X, and the grooves G2 and G4 between them are provided with an address pattern in the area of the zone Y.

FIG. 1C shows a reproduction output obtained when the light detector 1 detects the reflected light from the light irradiation portion when the light beam 1 passes over the track T2 of the land portion of the recording member. Shows the change of. Similar to the information area 3, in the address area 2, on the point P1 where the grooves G2 and G3 exist on both sides, the light incident on the reproducing optical system becomes low due to the diffraction effect of the grooves G2 and G3 on both sides, so the reproduction output is V2. Becomes On the other hand, the point P where only one side is the groove G3
2, the amount of reflected light is at point P1 because there is little diffraction of incident light.
A voltage V3, which is larger than the reflected light amount of V2 and higher than V2, is obtained. The address signal is reproduced by demodulating the signal of the light amount change.

As described above, the present invention forms an address by intermittently providing a groove without forming an address pit in the land area. Therefore, it is possible to manufacture a substrate compatible with land recording by the mastering process using a single laser beam used in conventional groove recording. Further, the width of the land region, which is a problem in the injection molding shown in the conventional example, can be dealt with by making it relatively large even when the track pitch is made small, that is, by making the width of the groove Gw small.

The present invention exhibits a remarkable effect under the narrow track condition where the track pitch is 1.2 μm or less. This effect will be described with reference to FIG. FIG. 2 shows the track pitch dependency of the transferability of the substrate obtained by injection molding.
The transferability is indicated by the ratio of the groove depth after injection molding to the groove depth of the master. In FIG. 2, (a), (b), (c)
Indicates that the relationship between the groove width Gw and the land width Lw is Gw = Lw + 0.1 (μm), Gw = Lw, Gw =
The measurement result when Lw-0.1 (μm) is shown.
(A) corresponds to the groove recording of the conventional example, and has a configuration in which the width of the track for recording information is kept large even when the track pitch is reduced. (C) is a case where the present invention is applied, in which the width of the groove forming the address is set small and the width of the land for recording information is set large.

Here, a substrate is formed by injection molding a polycarbonate resin, and a master is produced by a mastering process using an exposure apparatus using a single Ar laser light source shown in the conventional example. Generally, when the refractive index of the material used for injection molding is n and the wavelength of light used for recording and reproduction is λ, the groove depth d is set to be approximately equal to λ / (8n). This is because the servo signal used for tracking control becomes maximum at this depth, which is preferable. Specifically, the wavelength of light used was 780 nm, the refractive index of the polycarbonate resin was 1.6, and the groove depth of the master was 50 nm.

In FIG. 2, when the transferability is set to 95% as a reference, the track pitch of 1.2 μm is the limit in the conventional groove recording shown in (a), whereas it is shown in (c). In the present invention, it can be seen that the track pitch can be molded up to 1.0 μm. As described above, the present invention exhibits a remarkable effect under the track condition where the track pitch is 1.2 μm or less. If the difference between the groove width Gw and the land width Lw is further increased, this tendency becomes more remarkable.

An identifier for identifying the recording member according to the present invention and the conventional recording member is provided in a specific area of the disc. When this recording member is attached to the recording / reproducing apparatus, the polarity of tracking can be determined by checking the identifier. As the method of forming the identifier, firstly, it is provided in a part of the cartridge used for protecting the optical disc, and secondly, it is formed in the same manner as the address pits in the inner or outer peripheral side of the information area on the optical disc. The pit pattern may be used to provide the identifier. With this identifier, it is confirmed that the recording member has an address formed in a pattern different from that of conventional groove recording or land recording, that the address area is composed of multiple zones, and that the land side is an information track. To be done.

Here, the method of forming the address pits by intermittently forming convex grooves in the light incident direction has been described, but conversely, by intermittently forming the land portions to form the address pits, information is formed on the grooves. The same effect can be obtained for recording.

Further, by making the width of the groove and the width of the land equal to each other, it is possible to simultaneously demodulate the address signal on both tracks of the groove and the land and simultaneously record the signal on both tracks. Becomes

The present invention will be described in detail by showing a concrete configuration example. (Example 1) As a substrate material, polycarbonate, polymethylmethacrylate (PMMA), glass, etc.
A material that is optically transparent to the wavelength of the light beam used for recording and reproduction is desirable. Here, using polycarbonate for the substrate 5, the substrate having the configuration shown in FIG. 1 is formed. The groove has a track pitch Tp = 1.1 μm, a groove width Gw = 0.4 μm, and a depth d = 50 nm.
A master is prepared by a mastering process using an exposure apparatus using a single Ar laser light source shown in the conventional example, and an injection molding machine is used to form a substrate having the above configuration. Zn on the surface
Dielectric layer made of S-SiO2 110nm, GeSb
25 nm of phase change recording layer made of Te, ZnS-SiO
The recording layer 6 is provided by sequentially laminating a dielectric layer made of 2 to 20 nm and a reflective layer made of Au to 50 nm. The initial reflectance from the recording layer 6 is 30%, and when the recording mark 7 is formed, the reflectance is 10%.

FIG. 3 shows the configuration of a signal recording / reproducing apparatus formed according to the present invention. This recording / reproducing apparatus includes a laser drive circuit 20, a laser light source 21 (wavelength 780 nm),
It has an optical system including the objective lens 22 (NA = 0.55). The optical member irradiates the rotating recording member 23 with a light beam. Specifically, the laser light source 21 radiates a constant output (1 mW) light beam by the laser driving circuit 21, and the radiated light beam is condensed by the objective lens 22 and irradiated on the recording member 23.

This recording / reproducing apparatus further comprises a photodetector 24.
And a differential amplifier 25 to which the output of the photodetector 24 is input
And a tracking control unit 26 to which the output of the differential amplifier 25 is input, and an amplifier 2 to which the output of the photodetector 24 is input.
7, a comparator 28 connected to the amplifier 27, and a comparator 2
8 and a system controller 30 connected to the demodulator 29. Photodetector 24
Is divided into two in the direction perpendicular to the track and detects the reflected light from the recording member 23. 2 of photodetector 24
The difference between the two outputs is amplified by the differential amplifier 25, and the tracking control unit 26 is operated based on this differential signal, whereby the light beam can be tracked onto the land portion of the recording member 23. . As a result, it becomes possible to detect a change in the amount of reflected light from a specific track.
Note that the photodetector 24 is used by being further divided according to the focus servo system. On the other hand, the photodetector 24
The sum signal from is amplified by the amplifier 27, whereby the reflected light amount change corresponding to the recording mark 7 is obtained from the information area 3 as shown in FIG.
Changes the amount of reflected light corresponding to the address pit 4, and as a result, the reproduction signal S27 is obtained as an output signal.

In the information area 3, the change between the output V2 for the reflected light in the unrecorded state and the output V1 corresponding to the recording mark 7 when there are grooves on both sides is shown. By demodulating this level change, the information signal recorded in the information area 3 can be reproduced. On the other hand, the signal level of the reproduced signal S27 from the address area 2 is compared with the comparator 2
By comparing with the reference value Vs1 by 8, the binarized signal S28 is obtained. The reference value Vs1 is set to an intermediate level between the voltage V2 when grooves are present on both sides and the voltage V3 when only one side is a groove. Since the binarized signal S28 includes the information of the address pits 4 of the grooves G2 and G3 on both sides of the track, the demodulator 29 demodulates the address information for each zone X and Y,
The address of the track T2 is specified by comparing or adding the two demodulated signals by the system controller 30. For example, when using addition, the groove G2
Is "10", groove G3 is "11", groove G4
Is "12", the track T2 is "2".
1 "and" 23 "are obtained as the address information for the track T3. Information can be recorded by irradiating the predetermined track with light whose intensity is modulated by the semiconductor laser light source 21 based on the obtained address information. Also, the recorded information can be reproduced.

Although the case where the phase change material is used for the recording member has been described here, the present invention can be applied to all recording members having an optically detectable recording state, and the type of recording material is It does not limit the invention. Further, the shape of the groove, in particular, the groove depth, the angle of the region of the slope of the boundary between the land and the groove, and the like have not been described in detail, but these are not the restrictions of the present invention. However, it is possible to optimally select the respective values in consideration of the quality of the signal to be recorded, especially the signal amplitude, crosstalk, and the like.

As a method of detecting the address signal, a method of comparing the reproduced signal with a fixed reference level is used.
Detection using a differentiating circuit is also possible. Most of the signal demodulation is represented by an analog circuit, but the signal immediately after the photodetector is digitally converted by the A / D converter, and thereafter, the function shown in this embodiment is calculated to perform a predetermined address signal. It is also possible to obtain and information signals.

(Embodiment 2) In Embodiment 1, address pits are formed only on one side of a track consisting of lands.
Compared with the conventional groove recording shown in FIG. 18, the signal amplitude in the address area 2 is small. Therefore, in the second embodiment, in order to keep the signal amplitude of the address signal large,
A method of forming address pits having the same pattern in the grooves on both sides of the land will be described. The conditions other than the address pattern are basically the same as those in the first embodiment.

FIG. 4A shows an enlarged plan view of the vicinity of the address area of the optical information recording member of the present invention, and FIG.
The signal waveform S27 of the reproduction output obtained when the light beam 1 passes over the track T22 and the signal waveform obtained during the binarization process are shown in FIG. This recording member has an address area 2 and an information area 3 for groove recording. The recording mark 7 on the information area 3 shown in the first embodiment is omitted here for the sake of simplicity.

The address area 2 has a zone X, a zone Y and a zone Z which are close to each other on the groove. The address pits 4 are formed by intermittently forming grooves in any two zones in a pattern according to a predetermined code signal. The groove G21 has an address pattern P1x.
And P1z. The adjacent groove G22 is P
P2x having the same pattern as that of P1x is provided in a region adjacent to 1x, and P2y is provided in a region that is not adjacent to P1x and P1z. Similarly, groove G23
Also in the subsequent steps, as shown in the figure, the address patterns having the same pattern as the adjacent tracks are sequentially arranged.

The address signal reading operation in this recording member will be described with reference to the circuit diagram of FIG. 5 together with FIG.

The reproduced signal S27 obtained when the light spot 1 passes through the track T22 on the recording member is, as shown in FIG. 4B, grooves G22, G23 on both sides.
Is present at the point P1 where the groove G23 is present, and at the point P2 where the groove G23 is present on only one side, the output V3 is shown.
At the point P3 where there are no grooves on both sides, diffraction due to the grooves disappears, and the incident light is reflected according to the reflectance of the substrate surface, the amount of light increases, and the output V4 is obtained.
In this embodiment, the address information is detected by using the reproduction signal from the area sandwiched between P2y and P3y having the same pattern. That is, a signal amplitude equivalent to that of the conventional address pit 4 can be obtained from the address area 2 of this embodiment.

The demodulation of the address signal is performed by selecting the signal in the zone where the address pits 4 of the same pattern are present on both sides and binarizing it. In the circuit configuration for this demodulation, the part of the comparator 28 shown in the first embodiment is shown in FIG.
It can be obtained by replacing the circuit with the configuration shown in.
This circuit includes a comparator 31 to which the reproduction signal S27 is input,
36, an LPF (Low Pass Filter) 33, and a gate generator 32 to which the output signal S31 of the comparator 31 is input.
And a comparator 34 to which the output of the LPF 33 is input, a selector 35 to which the outputs of the gate generator 32 and the comparator 34 are input, and an AND circuit 37 to which the outputs of the selector 35 and the comparator 36 are input. Have and.

The address signal demodulation operation will be described below. First, the binarized signal S31 is obtained by the comparator 31 that compares the reference value Vs1 and the level of the reproduction signal S27.
The reference value Vs1 is set to a value between the level of the output V2 of the reproduction signal S27 and the level of the output V3. Preferably, in consideration of the level fluctuation of the reproduction signal S27 and the like, the value is set to an approximately intermediate value between both levels as in the present embodiment. The gate generator 32 includes an address region 2 formed on the substrate.
Width W2 corresponding to the width of each zone X, Y, Z
The gate signals S32 of 1, W22 and W23 are applied to the interval D21,
It occurs at D22. As shown in FIG. 4B, the gate signal S32 is converted into a binary signal S31 by the gate generator 32.
It occurs in synchronization with the rising edge of.

On the other hand, by passing the reproduced signal S27 through the LPF 33, the signal S33 as shown in FIG. 4B is obtained. The comparator 34 has a reference value Vs3, uses this reference value Vs3 to specify the zones where the address pits 4 exist on both sides, and outputs "1". This is because in the zone where the address pits 4 exist on both sides, the average amount of reflected light is
It is possible because it is larger than the average amount of reflected light in the zone where the address pits 4 do not exist on one side or both sides.
3 is set between the highest level of the signal S33 in the zone where the address pits 4 are present on both sides and the highest level of the signal S33 in the zone where the address pits 4 are present on only one side. Preferably, it is set to a value approximately halfway between both levels.

The selector 35 uses the 3 from the gate generator 32.
The gate when the output of the comparator 34 indicates "1" is selected from the two gates, and thus the selection gate signal S35 is selected.
To get

Further, the reproduced signal S27 is converted into a signal S as shown in FIG. 4B by the comparator 36 having the reference value Vs2.
Get 36. The reference value Vs2 is set to a level of about 1/2 of the output voltage V4 when the address pits 4 are present on both sides. The AND circuit 37 uses the selection gate signal S3.
5 and the signal S36 outputs a binarized signal S28.
In this way, the address signal from the zone having the address pits 4 on both sides can be obtained.

As described above, since the comparator 36 for obtaining the binarized address signal can be set to operate at the reference value Vs2 higher than the reference value Vs1 of the first embodiment, the reproduction signal It becomes possible to secure high reliability against level fluctuations or level fluctuations of reference values.

(Third Embodiment) In the second embodiment, an address signal having a large amplitude is obtained by separating the address area 2 into three zones. However, here, the address signal from the land portion is used in only two zones. The method for identifying FIG. 6A shows a plan view in the vicinity of the address area,
(B) shows a reproduced signal and a binarized signal obtained when the light beam passes over the track T32. The address area 2 is composed of two zones X and Y which are adjacent to each other. Each groove G31, G32, G33, G34,
In order for the pattern of the address pits 4 in either zone X or Y to be the same pattern as the adjacent groove,
The tracks are arranged so that the zones change alternately for each track.
The shape of each groove is the same as that of the first embodiment.

The reproduced signal S27 obtained when the track T32 of this recording member is reproduced has a large amplitude change from the zone Y because the pattern of the address pits 4 on both sides is the same as in the second embodiment. . In the zone X, since the address patterns on both sides are different, the amplitude change as large as that in the zone Y cannot be obtained. By utilizing the difference, the zone Y in which the address information corresponding to the track T32 is recorded is specified.

However, even in the zone X, a large amplitude change is observed in a region where the planes of the adjacent grooves G32 and G33 overlap each other. Therefore, the false pulse 31 is generated also in the binarized signal S28. However, these erroneous pulses are judged as an error address area in the error correction stage of the process of demodulating the address information and can be ignored. For example, if the address pit 4 has a form provided with a plurality of address information and a parity for error correction, by comparing the error amount of the parity when reproducing the address information and selecting a zone with a small error amount, It is possible to specify the target address zone.

As described above, according to the present embodiment, it is possible not only to obtain the address reproduction signal having a large amplitude change as in the second embodiment but also to reduce the width of the address area 2 and the information area of the recording member. The area of 3, that is, the recording capacity can be increased.

(Embodiment 4) Here, in order to improve the accuracy of demodulation of an address signal divided into a plurality of zones, a recording member provided with an area indicating the start of the address area and a reproducing method thereof will be described. explain. Figure 7
(A) is a plan view of the vicinity of the address area of the recording member,
(B) shows a reproduced signal and a binarized signal. The recording member of this embodiment has a groove G51 in the front part of the address area 2.
The address start zone 51 is composed of G to G54 intermittently. In the address start zone 51, the same pattern as that of the adjacent grooves G51 to G54 is always formed. The pattern of the subsequent address pits 4 can be applied to any of the first to third embodiments described above. Here, the pattern of Example 1 is shown.

Signal reproduction from the recording member will be described with reference to the circuit shown in FIG. 8 and the signal waveform shown in FIG. 7B. The address demodulation is performed by the comparator 28 of FIG.
This is possible by changing only the function of the above, and FIG. 8 shows only the contents of the circuit to be changed. This circuit includes two comparators 61 and 6 to which the reproduced signal S27 from the amplifier 27 is input.
2, a gate generator 63 to which the output signal S61 of the comparator 61 is input, and an AND circuit 64 to which the output signals S62 and S63 of the comparator 62 and the gate generator 63 are input.

As shown in FIG. 7B, the track T52
Address reproduction signal S27 when the light beam 1 passes above
Shows a large optical output V4 because the both sides are flat in the address start zone 51, and the amplitude change of the optical output V3 shows in the portion where one side is a plane in the subsequent address area 2. The comparator 61 outputs a level Vs that is an intermediate level between the optical output V3 and the optical output V4.
Set the reference voltage to 2. As a result, from the comparator 61, only from the portion corresponding to the address start zone 51,
The binarized signal S61 is output. Corresponding to the rising of S61, the gate generator 63 generates gate signals G1 and G2 having a predetermined width from a timing delayed by a constant delay time D1 from S61. This delay time D1,
The times of the gate signals G1 and G2 and the gate interval D2 can be set in advance in the gate generator 63 according to the setting conditions of the zone of the address area used in the mastering process of the recording member.

On the other hand, the comparator 62 sets the reference signal Vs1 to the middle of V2 and V3 as in the first embodiment, and as a result, the binarized signal S62 is obtained. Next, the AND circuit 64 obtains the signal S28 by taking the logical product of the signal S61 and the signal S62. The signal S28 is 2 in the first embodiment.
The pattern is the same as that of the binarized signal S26, and thereafter, the address signal can be demodulated by the same circuit.

With the above configuration, the address start zone 5
From No. 1, reproduction is always performed at the same position and at the same timing with respect to the rotation of the recording member, and the patterns of adjacent tracks are also the same, so that the position of the address area can be stably detected. As a result, as in the present invention, it is possible to demodulate address signals generated from different zones at a plurality of places with high accuracy. Although not described in detail here, it is clear that the patterns corresponding to the second and third embodiments also have the same effect.

(Embodiment 5) As shown in FIG. 9A, in the address patterns shown in Embodiments 1, 2 and 4, there is a zone where one side of the track is a continuous groove. For this reason,
The differential output S25 from the differential amplifier 25 used for the tracking control shown in FIG.
As shown in (b) and (c), depending on which side the address pit 4 exists in the traveling direction of the track,
Indicates a level change. However, since there is a frequency band that can be followed by the control system, malfunction does not easily occur when the rotation speed of the optical disk is high. However, in the case of a low rotation speed, the signal change in the address area 2 approaches the control frequency band and the control signal becomes as shown in FIG. 9C, which may cause the tracking control to malfunction.

In order to deal with this, FIG. 9 is used in this embodiment.
As shown in (d), the groove G75 of the zone G75x adjacent to the zone G74x in which the address pit 4 exists.
The groove width Gw2 is smaller than the groove width Gw of the information area 3. That is, when one side is a continuous groove and the other side is a zone in which address information is recorded, it is possible to equalize the influence of diffraction on the light beam 1 from the grooves G74 and G75 on both sides. When the light beam 1 passes over the track T74 having such an address area 2,
As shown in (e), the differential signal S25 has a minute change centered on OV. Since the change of the signal S25 is a change that cannot be followed in the band of the tracking servo, it becomes a control signal with little fluctuation as shown in FIG. 9 (f). As a result, stable tracking servo operation becomes possible.

The address area 2 obtained in this case
The signal level obtained from the address pit 4 of the reproduction signal obtained from the above-mentioned embodiment becomes smaller than that of the first and second embodiments. This case can be dealt with by lowering the reference level relatively.

As another method, stable tracking control can be performed by using the address pits 4a having a pattern as shown in FIG. In this method, the address pit 4a
Is set to be larger than the width Gw of the groove G78, thereby canceling the increase in the amount of reflected light at the point P7 between the address pits 4a. That is, in the portion where the wide address pit 4a is present, the amount of reflected light is reduced due to the diffraction effect of the light beam 1, and the increased amount is canceled by the reduced amount.

Although the method of forming the address pits based on the pattern of the first embodiment is used here, the method of forming the address pits of the same pattern on the adjacent tracks shown in the second embodiment can also be applied. . In the case of the second embodiment, it is applied to a portion where one side of the address pit is a continuous groove, and a method of making the groove width of the continuous groove smaller than the width of the address pit, or the width of the address pit of the groove Any method of making the width larger than the width can be applied.

(Embodiment 6) The embodiments and the conventional optical discs described so far are of the type in which the address area and the information area are separately recorded in the circumferential direction, but here, the address areas overlapping each other are used. A method of recording and reproducing information in and from the information area will be described. FIG. 11A shows a configuration diagram of the optical disc of this embodiment, and FIG. 11B shows a reproduced signal waveform.

As shown in FIG. 11A, the address pattern of the optical disk substrate of this embodiment has the same form as that of the first embodiment, and the information area 3 for recording the information signal overlaps the address area 2 and the land The only difference is that recording marks 7 are continuously formed on the top. The process of irradiating the track T81 with the light beam 1 and demodulating the reproduction signal obtained as a result will be described with reference to the signal demodulation system of FIG. 12 and the signal waveform of FIG. 11B. Note that the input signal in FIG.
The photodetector 24 divided vertically in the track indicated by
Amplifier output S27 of the sum signal and differential amplifier output S25
To use.

As shown in FIG. 11B, the amplified signal S27 of the sum signal shows a waveform in which the reflectance change due to the recording mark 7 and the diffraction effect due to the address pit pattern are combined. On the other hand, the differential amplifier output S25 shows a change corresponding to the presence or absence of the address pit 4 adjacent to the track T81.
The polarity is inverted depending on whether or not the

FIG. 12 shows a block diagram of an address signal and information signal demodulation circuit. This demodulation circuit includes an attenuator 90 to which the amplifier output S27 is input, a differential amplifier 91 to which the output of the attenuator 90 and the differential amplifier output S25 are input, and an absolute input to which the output of the differential amplifier 91 is input. The value circuit 92 and the comparator 96 to which the output of the absolute value circuit 92 is input
A differential amplifier 97 to which the amplifier output S27 and the output of the absolute value circuit 92 are input, and a comparator 98 to which the output of the differential amplifier 97 is input. The operation of the demodulation circuit having such a configuration will be described below.

The operation amplified signal S25 is affected by the waveform distortion due to the difference in reflectance caused by the presence or absence of the recording mark 7. In order to reduce this effect, the sum signal S27 is differentiated by the differential amplifier 91 by using the signal S90 and the differential signal S25 which are attenuated by the attenuator 90 exhibiting a constant attenuation rate according to the degree of reflectance change. The signal S91 is obtained. Differential signal S9
The absolute value circuit 92 converts 1 into an amplitude change only in the positive direction to obtain a signal S92. More specifically, the absolute value circuit 9
In 2, the two diodes 93a and 93b are used to change the amplitude in only one direction, the negative amplitude is inverted by the differential amplifier 94, and the amplifier 95 outputs the output signal S93a of the diode 93a and the output signal S94 of the differential amplifier 94. A signal S92 is obtained by amplifying the sum of the above. This signal S9
From 2, the binarized signal S96 is obtained by comparing the level with a predetermined reference value by the comparator 96 in the same manner as in the first embodiment. The track can be specified by demodulating the address signal based on the signal S96.

On the other hand, the sum signal S27 corresponding to the change in reflectance of the recording mark 7 causes waveform distortion due to the influence of the adjacent address signal. This waveform distortion can be suppressed by subtracting the absolute value circuit output S95 from the sum signal S27 using the differential amplifier 97. That is, the diffraction amount of light when there are grooves on both sides is larger than the diffraction amount when there are address pits 4, and the change in this diffraction amount is
It can be said that it is proportional to the difference in the amount of light on the two photodetectors. The output signal S97 obtained as a result shows the reproduction amplitude corresponding to the shape of the recording mark 7 in which the amplitude change due to the address pit is suppressed. Then, by passing S97 through a comparator 98 having a reference level VS4 intermediate between voltages V1 and V2,
A binarized signal S98 corresponding to the pattern of the recording mark 7 is obtained. In order to remove the influence of the address pit 4 with higher accuracy, the amplitude of S95, which is the input signal to the differential amplifier 97, can be finely adjusted according to the groove shape.

As described above, the address signal and the reproduction signal from the recording mark 7 can be independently demodulated in the recording member in which the address area 2 and the recording area 3 are superposed by the substrate and the reproduction system of this structure. Is possible.

(Embodiment 7) In Embodiments 1 to 6, the method of recording a signal only on the land portion is described. From now on, a method of recording information on both the land and the groove will be described.

FIG. 13A is an enlarged plan view showing the vicinity of the address area of the optical information recording member of the present invention, and FIG.
Shows a sectional view of the address area 2 in FIG. In FIG. 13C, the light beam 1 has a track L on the land.
The reproduced output signal waveform obtained when the signal passes through 102 and the signal waveform when binarized are shown. Conversely, the reproduced output from the groove G on track G103 and the binarized signal are shown in (d). Shown in. The shape of the guide groove shown here is the same pattern as that of FIG. 1, but the width Gw of the groove portion and the width Lw of the land portion in the direction perpendicular to the track are set to substantially the same value. The grooves G101 and G103 are provided with an address pattern in the zone X area, and the grooves G102 and G104 between them are provided with an address pattern in the zone Y area.

In the address area 2, the land L102
When the light beam 1 passes above, the point P10 where the grooves G102 and G103 exist on both sides as in the information area 3
1 there is a diffraction effect of the grooves on both sides, and there is a reproduction signal SL119.
Becomes a voltage V102. On the other hand, the groove G1 only on one side
On point P102 where 02 does not exist, one side is a flat surface, so that the diffraction of incident light is reduced and the amount of light is increased, so that voltage V103 is obtained. By comparing this light amount change signal with the reference voltage, address information from the two zones X and Y is obtained, and by demodulating this, the address of the track L102 through which the light beam 1 is passing is specified. be able to.

On the other hand, when the light beam 1 passes over the groove, a change in the amount of reflected light corresponding to the address pit 104 is observed as in the conventional groove recording. That is, in the area where the address pits 104 are present, the amount of reflected light is equal to that of the groove portion, and the reproduction signal SG119 is the voltage V105, whereas in the area where the address pits 104 are not present, the amount of reflected light is increased and the voltage V106 is can get.
The address information is reproduced by demodulating the signal of the change in the light amount.

With the above configuration, even when the address from the land portion is reproduced, the address information is detected by detecting the change in the diffraction amount of the reflected light due to the address pits 104 formed by the intermittent grooves. Obtainable. Therefore, the substrate corresponding to the land recording can be prepared by the mastering process using the single laser beam used in the conventional groove recording.

The structure of the guide groove is as described above.
It is desirable that the vertical groove width Gw and the land width Lw of the track be substantially equal. That is, when each of the land portion and the groove portion is irradiated with the light beam 1 and the reflected light is measured, the value changes depending on the groove width. By making the widths of both parts equal, it is possible to keep the amount of reflected light on the photodetector constant. Therefore, it is possible to obtain the same signal amplitude from the signals recorded in either the land portion or the groove portion. From the above viewpoints, it is desirable that Gw / Lw is in the range of 0.7 to 1.3 as the range of the groove width.

As described above, the depth d of the guide groove is generally set in the vicinity of λ / (8n) or an odd multiple thereof so that the tracking signal is maximized. However, when an information signal is recorded on both the land and the groove, the reproduced signal from the recording mark 107 recorded on both the land and the groove is affected by the change in the adjacent recording mark 107 (also referred to as crosstalk). It is necessary to set the depth d so that the amount of talk is minimized. As a result of experimenting the amount of this crosstalk by using the substrate with the groove depth d changed,
There was a tendency that the recording signal was large and the crosstalk amount was small in the vicinity of λ / (5n) which is between λ / (8n) and λ / (4n). As described above, when recording a signal on both the land and the groove, it is necessary to make both the groove widths the same and to select the groove depth optimally, as compared with the case of recording the groove on one side. , They can experimentally find the optimum value according to the required signal quality.

For the substrate having the structure shown here, a master was prepared by the mastering process using the exposure apparatus using the single Ar laser light source shown in the conventional example, and the substrate having the above structure was formed by the injection molding machine. . A thin film corresponding to a recording method in which the optical characteristics of the thin film are changed by irradiation of light shown in the conventional example, for example, deformation recording, phase change recording, magneto-optical recording, photon mode recording, etc., can be applied to the surface. The recording member shown in FIG. 13 is an example in which a phase change thin film capable of reproducing a signal by changing the reflectance is provided as a recording layer, and the recording mark 107 obtained by laser irradiation is different from the initial state in the initial state. The reflectance decreases.

FIG. 14 shows the configuration of a signal recording / reproducing apparatus formed according to the present invention. The structure and operation of this recording / reproducing apparatus will be described below.

This recording / reproducing apparatus has a laser light source 110.
And a light beam from the laser light source 110 is recorded on the recording member 112.
And the recording member 11
An optical system including a photodetector 113 for detecting the reflected light from the optical pickup 2, a voice coil 116 supporting the objective lens 111, a differential amplifier 114 to which the output of the photodetector 113 is input, and a differential amplifier. The inverter 118 to which the output of the amplifier 114 is input, the tracking control unit 115 to which the output from the inverter 118 is input, and the system controller 11
7 and 7.

The optical system uses a laser light source 110 and an objective lens 111 to irradiate a rotating recording member 112 with light, and uses a photodetector 113 having a plurality of light receiving surfaces for reflected light to perform focus control and tracking control. I do. The tracking control uses output signals from the light receiving surface divided in the direction perpendicular to the tracks of the photodetector 113, a level difference between these output signals is amplified by a differential amplifier 114, and this differential signal is Based on the tracking control unit 115
The voice coil 11 that directs the objective lens 111 by
By operating 6 the light beam is tracked in the guide groove on the recording member 112. It should be noted that which surface of the land or groove of the guide groove of the recording member is subjected to tracking control is driven by the inverter 118 which inverts the polarity of the output of the differential amplifier 114 according to the setting of the system controller 117. To be selected.

This recording / reproducing apparatus has an amplifier 119 to which the output from the photodetector 113 is input, and a comparator L120 and a comparator G122 to which the output of the amplifier 119 is input.
And a demodulator L121 and a demodulator G12 to which outputs from the comparator L120 and the comparator G122 are input, respectively.
3 is further provided.

The sum signal at the output of the photodetector 114 is the amplifier 1
In the case of a land, as shown in FIG.
3 (c), in the case of a groove, as shown in FIG. 3 (d), a change in reflected light amount corresponding to the recording mark 107 from the information area 3 and the address pit 104 from the address area 2 is obtained.

When the light beam 1 scans the land L2, the signal SL119 corresponding to the change in the amount of reflected light is obtained from the amplifier 119 as shown in FIG. 13C. In the information area 3, a voltage V102 corresponding to the reflectance when there are grooves on both sides and an output V10 corresponding to the recording mark 107.
The change from 1 is shown. Playback signal SL from address area 2
The signal level of 119 is set to the reference value VS by the comparator L120.
Compare with 101. The reference value VS101 is set to an intermediate level between the voltage V102 when the groove exists on both sides and the voltage V103 when the groove exists on one side. Two
Since the binarized signal S120 includes the information of the address pits 107 of the grooves G102 and G103 on both sides of the track L102, the address information is demodulated by the demodulator L121 for each zone X and Y, and two demodulated signals are generated by the system controller. At 117, the address of the land L102 is specified by comparison or addition. For example, when using addition, the groove G102 is "1".
0 ", groove G103 is" 11 ", groove G104
Is "12", the land L102 is "2".
1 "and the land L103" 23 "are obtained as address information.

On the other hand, the reproduction signal SG1 of the groove G102.
As shown in FIG. 13D, reference numeral 19 shows a change in the output V105 with respect to the reflected light in the unrecorded state on the groove in the information area 3 and the output V104 corresponding to the recording mark 107.
By demodulating this level change, the information signal from the information area 3 can be reproduced. On the other hand, by comparing the signal level of the reproduction signal SG119 from the address area 2 with the reference value Vs102 by the comparator G122, the binarized signal S122 is obtained, and based on this signal, the demodulator G123 Demodulate the address signal.

From the obtained address information, the current position of the light beam 1 is specified, and the position of the light beam 1 is moved by the tracking drive means in accordance with the difference from the target track. It becomes possible to follow. For this track, the semiconductor laser light source 11
By modulating the intensity of 1, it is possible to record an information signal or reproduce a prerecorded information signal. That is, from the recording mark 107 formed on the land L102, the signal SL119 is compared by using a third comparator with an intermediate level between the voltage V101 and the voltage V102 as a reference level, and demodulated to obtain an information signal. Can be played. Information reproduction on the groove can be reproduced by the same method.

As described above, the address can be specified from the track on either side of the land or groove, and information can be recorded or reproduced on any track.

(Embodiment 8) In the case where the address pits are alternately provided in different zones on the groove as in the embodiment 7, the address reproduction amplitude when tracking to the land is more than that when the groove is reproduced. It is getting smaller. This embodiment describes a method of forming address pits having the same pattern in the grooves on both sides of the land in order to keep the signal amplitude of the address signal large even when reproducing the groove. The conditions other than the address pattern are basically the same as those in the seventh embodiment.

FIG. 15A is an enlarged plan view showing the vicinity of the address area of the optical information recording member of the present invention, and FIG.
Shows a signal waveform of reproduction output and a binarized signal waveform obtained when the light beam 1 passes over the land L122,
(C) shows a reproduction output and a binarized signal waveform obtained when the light beam 1 passes over the groove G123. The recording marks in the information area 3 are omitted here for the sake of simplicity.

The address area 2 has a zone X, a zone Y and a zone Z which are close to each other on the groove. The address pits 104 are formed by intermittently forming grooves in any two zones in a pattern according to a predetermined code signal. The groove G121 has the address pits 104 in the zones X and Z. Adjacent groove G122 has address pits 104 in the same pattern as zone X of G121 in zone X, and
Has an address pit 104 of a new address pattern. Zone Z is a continuous groove. Similarly, groove G12
As shown in the figure, the address patterns of the same patterns as those of the adjacent tracks are sequentially arranged for the third and subsequent tracks.

For the demodulation of the address signal, the one having substantially the same configuration as that of the seventh embodiment is used. Land L of the above recording member
The reproduced signal SL119 from the 122 is the groove G on both sides.
At the point P101 where 122 and G123 exist, the information area 3
Shows the same output V102 as that of the groove G12 on only one side.
An output V103 is shown from a point P102 where 3 exists. At the point P103 where there is no groove on both sides, diffraction due to the grooves disappears, and the incident light is reflected according to the reflectance of the substrate surface, and the amount of light is increased to output V107. In this land L122, the address information is detected using the reproduction signal from the point P103, that is, the zone Y. From the address area 2, if the width of the address pit is equal to the width of the land portion, a signal amplitude similar to that of the groove can be obtained.

Therefore, when demodulating the address reproduction signal SL119, the binary signal S120 is obtained by setting the comparator L120 to operate at the reference value Vs103 higher than that of the seventh embodiment. Further, in the case of the substrate of this configuration, by setting the reference level Vs103 by using the comparators L120 and G122 as independent comparators, it is possible to binarize the address signal from the land and the groove.

It should be noted that the reproduction signal S using the reference value Vs103.
Although L119 is binarized, it is conceivable that the amplitude of the address pit 104 on one side becomes larger than this value due to the formation state of the address pit 104, the fluctuation of the reproducing device, and the like. In order to eliminate this, address pits 104 are formed on both sides immediately after the amplifier 119, as in the second embodiment.
It is possible to provide a gate selection circuit that selects only the zone in which there is a. This gate selection circuit includes a gate generator that generates three gates at a time corresponding to the width of the zone used in advance in the mastering process of the substrate, and a phase that matches the timing of the gate signal with the amplitudes of the reproduction signals SL119 and SG119. The amplitude of the reproduction signal in each gate is compared with that of the lock circuit, and the gate having the maximum amplitude is specified. The reproduced signal in the obtained gate is compared with the comparator L12.
By inputting 0 and G122, a highly accurate address signal can be obtained from a plurality of address pit signals.

On the other hand, the address reproduction signal of the groove G123 is obtained from the zone Y and the zone Z in which the address pits 104 are present. The two addresses are demodulated respectively, and the demodulated result is used by the system controller 117 in the first embodiment. By performing the same calculation as in the case of land, the address of the track can be specified.

(Embodiment 9) In the embodiment 8, the address area is set to 3
A method of obtaining an address signal having a large amplitude from the land by separating the zones into two zones has been described. Here, a method using two zones will be described. FIG. 16A shows a plan view in the vicinity of the address area, and FIG. 16B shows a reproduction signal obtained when the light beam 1 passes over the land L132,
And a binarized signal. The address area 2 is composed of two zones X and Y which are adjacent to each other. Each groove is
In order for the pattern of the address pits 104 in any of the zones X and Y to be the same pattern as the adjacent groove,
The tracks are arranged so that the zones change alternately for each track.
The shape of each groove was the same as in Example 7.

The reproduction signal SL119 obtained when the land L132 is reproduced has a large amplitude change from the zone Y because the pattern of the address pits 104 on both sides is the same as in the eighth embodiment. In the zone X, since the address patterns on both sides are different, the amplitude change as large as that in the zone Y cannot be obtained. By utilizing the difference, the zone Y in which the address information corresponding to the track T132 is recorded is specified.

However, even in the zone X, a large amplitude change is observed in the area where the planes of the adjacent grooves G132 and G133 overlap. Therefore, the binarized signal S12
Even at 0, the false pulse 121 is generated. However, these false pulses 121 are determined as an error address area in the error correction stage of the process of demodulating the address information,
It can be ignored.

The address reproduction signal of the groove G132 is
As in the eighth embodiment, two addresses are obtained corresponding to the two zones, the two addresses are respectively demodulated, and the demodulated result is calculated by the system controller 117 in the same manner as in the case of the land of the seventh embodiment. The address can be specified.

As described above, according to this embodiment, the same high address reproduction signal is secured as compared with the eighth embodiment, and
The width of the address area can be reduced, and the area of the information area of the recording member, that is, the recording capacity can be increased.

Although not described in the seventh to ninth embodiments, the method of providing an area indicating the start of the address area prior to the address area shown in the fourth embodiment is a method of recording a signal on both the land and the groove. Can be similarly applied. Further, in the method of reducing the groove width of the continuous groove adjacent to the address pits or the method of increasing the width of the address pits larger than the width of the groove as shown in the fifth embodiment, signals are recorded on both the land and the groove. The method can be similarly applied.

[0121]

As is apparent from the above description, according to the optical information recording member of the present invention, it is possible to realize the guide groove having a high track density and the address information.
According to the recording / reproducing apparatus of the present invention, it is possible to record information on such a recording member and stably reproduce the address information and the recorded information from the recording member.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration diagram in the vicinity of an address area of an optical information recording member of Example 1 of the invention and a diagram showing a reproduced signal waveform

FIG. 2 is a characteristic diagram showing track pitch dependency of Example 1.

FIG. 3 is a block diagram showing a configuration of a recording / reproducing apparatus according to a first embodiment.

FIG. 4 is a diagram showing a configuration diagram and a reproduction signal waveform in the vicinity of an address area of an optical information recording member of Example 2.

FIG. 5 is a block diagram showing a configuration of a comparison circuit of the recording / reproducing apparatus of the second embodiment.

FIG. 6 is a diagram showing a configuration diagram and a reproduction signal waveform in the vicinity of an address area of an optical information recording member of Example 3;

FIG. 7 is a diagram showing a configuration diagram and a reproduction signal waveform in the vicinity of an address area of an optical information recording member of Example 4.

FIG. 8 is a block diagram showing a configuration of a comparison circuit of the recording / reproducing apparatus according to the fourth embodiment.

FIG. 9 is a diagram showing a configuration diagram in the vicinity of an address area and a reproduced signal waveform of an optical information recording member of Example 5.

FIG. 10 is a diagram showing a configuration diagram and a reproduction signal waveform in the vicinity of an address area of the optical information recording member of Example 5.

FIG. 11 is a diagram showing a configuration diagram and a reproduction signal waveform in the vicinity of an address area of an optical information recording member of Example 6.

FIG. 12 is a block diagram showing an address detection circuit and a data detection circuit of a recording / reproducing apparatus of Example 6.

FIG. 13 is a diagram showing a configuration diagram and a reproduction signal waveform in the vicinity of an address area of an optical information recording member of Example 7.

FIG. 14 is a block diagram showing the configuration of a recording / reproducing apparatus of Example 7.

FIG. 15 is a diagram showing a configuration diagram in the vicinity of an address area of an optical information recording member of Example 8 and a reproduction signal waveform.

FIG. 16 is a diagram showing a configuration diagram and a re-signal waveform in the vicinity of an address area of the optical information recording member of Example 9.

FIG. 17 is a diagram showing a configuration diagram and a reproduction signal waveform in the vicinity of an address area of conventional groove recording.

FIG. 18 is a diagram showing a configuration diagram and a reproduction signal waveform in the vicinity of an address area of conventional land recording.

FIG. 19 is a flowchart showing a conventional manufacturing process of a grooved substrate.

FIG. 20 is a cross-sectional view showing a state of injection molding of a substrate having a groove having a narrow width.

[Explanation of symbols]

 1 light beam 2 address area 3 information area 4 address pit 7 recording mark

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shinji Ohno 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (26)

[Claims] 1. A change that can be optically detected by irradiating light on a substrate having a track on an uneven surface having a first surface and a second surface having different optical positions with respect to the incident direction of a light beam. A recording member having a recording thin film layer for generating the information, wherein the track has an information recording area in the track direction and an address area having management information of the information recording area, and the address area is a track formed of the first surface. Is an optical information recording member in which a part of each of the information recording areas is formed so as to be isolated according to a predetermined code signal, and the information recording area has an information recording area on at least a guide track formed of the second surface. 2. A change which can be optically detected by irradiating light on a substrate having a track on an uneven surface composed of a first surface and a second surface having different optical positions with respect to the incident direction of a light beam. A recording member having a recording thin film layer for generating the information, wherein the track has an information recording area in the track direction and an address area having management information of the information recording area, and the address area is a track formed of the first surface. Of the address pits, which are isolated from each other in accordance with a predetermined code signal, and the track pitch of the tracks formed on the first surface is 1.2 μm.
An optical information recording member smaller than m and having a width of a track formed of the first surface smaller than a width of a track formed of the second surface. 3. The optical information recording according to claim 2, wherein the address area is composed of at least two zones adjacent to each other in the track direction, and the track composed of the first surface is provided with an address pit row in at least one of the zones. Element. 4. The optical information recording member according to claim 3, wherein the tracks formed of the first surface adjacent to both sides of the track of the address pit row in the vertical direction are continuous. 5. In a zone in which a track on the first surface has a continuous shape and a track vertically adjacent to the track has address pits, the width of the track on the first surface is The optical information recording member according to claim 4, wherein the width is smaller than the width in the information area. 6. In a zone where tracks on the first surface have a continuous shape and a track vertically adjacent to the track has address pits, the width of the address pits in the information area is The optical information recording member according to claim 4, which is larger than the width. 7. The optical information recording member according to claim 2, wherein the track on the first surface having the address pit is convex in the incident direction of the light beam. 8. The optical information according to claim 2, wherein an address start zone indicating a start point of address information is provided at a head portion of the address area, and the start zones have the same pattern between adjacent tracks. Recording member. 9. A change that can be optically detected by irradiating light on a substrate having a track on the surface of which unevenness is formed by a first surface and a second surface having different optical positions with respect to the incident direction of a light beam. A recording member having a recording thin film layer for generating the information, wherein the track has an information recording area in the track direction and an address area having management information of the information recording area, and the address area is a track formed of the first surface. Of the address pits, which are isolated from each other in accordance with a predetermined code signal, and the address areas are at least 2 adjacent to each other in the track direction.
An optical information recording member having two zones, wherein the pattern of address pits of at least one zone on the track formed of the first surface is the same as that of the adjacent track of the first surface. 10. In the zone where the address area has three zones and the address pits of the track formed of the first surface, one track of adjacent tracks has the same pattern of address pits and the other track of the other track has the same area. The optical information recording member according to claim 9, wherein the track has a continuous shape. 11. In a zone in which a track on the first surface has a continuous shape and a track vertically adjacent to the track has an address pit, the width of the track on the first surface is The optical information recording member according to claim 10, which is smaller than the width in the information area. 12. In a zone in which a zone of a track formed of the first surface is continuous and a track vertically adjacent to the track has an address pit, the width of the address pit is in the information area. The optical information recording member according to claim 10, which is larger than the width. 13. The optical information recording member according to claim 9, wherein the address area has two zones, and in each track, address pits are provided in both zones. 14. A change which can be optically detected by irradiating light on a substrate having a track on an uneven surface composed of a first surface and a second surface having different optical positions with respect to the incident direction of a light beam. Is a recording member having a recording thin film layer for generating information, and having both the first surface and the second surface of the track as information recording areas, the track being an information recording area in the track direction and management of the information recording area. An address area having information, wherein the track width of the first surface and the track width of the second surface are substantially equal to each other, and the address area defines a part of the track formed of the first surface by a predetermined code signal. An optical information recording member consisting of a row of address pits formed separately according to the above. 15. The address area has at least two zones that are adjacent to each other in the track direction, the track formed of the first surface has an address pit row in at least one zone, and the zone having the address pit row has The track formed of the first surface adjacent to both sides has a continuous shape.
4. The optical information recording member described in 4. 16. The width of a track formed by the first surface is a zone in which a track formed by the first surface has a continuous shape and a track vertically adjacent to the track has an address pit. The optical information recording member according to claim 15, wherein the width is smaller than the width in the information area. 17. In a zone in which a zone of a track formed of the first surface is continuous and a track vertically adjacent to the track has an address pit, the width of the address pit is in the information area. The optical information recording member according to claim 15, which is larger than the width. 18. The address area has at least two zones adjacent to each other in the track direction, and the address area has a pattern in which address pits of at least one zone on the track formed of the first surface are adjacent to each other. 15. The optical information recording member according to claim 14, which is the same as the track on one surface. 19. In the zone where the address area has three zones and the address pits of the track formed of the first surface, one track of adjacent tracks has the same pattern of address pits, and the other track of the other tracks has the same area. 19. The optical information recording member according to claim 18, wherein the track has a continuous shape. 20. The optical information recording member according to claim 18, wherein the address area has two zones, and both tracks have address pits in both zones. 21. The optical information according to claim 14, wherein an address start zone indicating a start point of address information is provided at a head portion of the address area, and the start zone has the same pattern between adjacent tracks. Recording member. 22. A change which can be optically detected by irradiating light on a substrate having a track on the surface of which unevenness is formed by a first surface and a second surface having different optical positions with respect to the incident direction of the light beam. Is a recording member having a recording thin film layer, the track having an information recording area in the track direction and an address area having management information of the information recording area, the address area being a track formed of the first surface. Is a device for recording / reproducing an information signal by irradiating a light beam on a recording member composed of a series of address pits which are formed by isolating a part of them in accordance with a predetermined code signal. Light detecting means for detecting reflected light of the beam, and for making the light beam follow the second surface between the first surfaces provided with the address pit row from the output signal of the light detecting means An optical information recording / reproducing apparatus including tracking means and address demodulating means for demodulating a pattern of an address pit string formed in the address area by comparing an output signal of the photodetecting means with a predetermined reference voltage. . 23. Gate demodulating means for demodulating the address signal, which generates a gate signal having a plurality of address reproducing gates having a constant time width, and the gate signal and the address reproducing signal are synchronized with each other. And a gate selecting means for selecting a specific gate by comparing a detection level or an error rate of the address signal included in the synchronized gate signal among the plurality of gates. 23. The optical information recording / reproducing apparatus according to claim 22, wherein address information is specified from the demodulated signal between the selected gates. 24. An address start zone, wherein the recording member is arranged at a head portion of the address area and has the same pattern between tracks adjacent to each other, the address start zone indicating a start point of address information, The recording / reproducing apparatus includes an address start zone recognition means for specifying the address area start zone from the output signal of the light detection means, and a constant time width after a certain time delay from the output signal from the address start zone recognition means. 23. The optical information recording / reproducing apparatus according to claim 22, further comprising: a gate generating unit for generating a gate pulse having the signal, the demodulating unit demodulates a signal change occurring within the gate pulse period. 25. A change that can be optically detected by irradiating light on a substrate having a track on the surface of which unevenness is formed by a first surface and a second surface having different optical positions with respect to the incident direction of the light beam. Is a recording member having a recording thin film layer, the track having an information recording area in the track direction and an address area having management information of the information recording area, the address area being a track formed of the first surface. Is a device for recording / reproducing an information signal by irradiating a light beam onto a recording member consisting of a series of address pits formed in isolation according to a predetermined code signal. A light detecting means for detecting the reflected light of the light beam, which is divided in the vertical direction of the track, and a track for causing the light beam to follow the second surface according to an output signal of the light detecting means. Means, an adding means for obtaining a sum of outputs of the light detecting means, a differential means for obtaining an output difference of the light detecting means, and an absolute value for obtaining an absolute value signal of an output signal of the differential means. Means, address demodulating means for demodulating address information by comparing the output signal of the absolute value means with a first reference level, and a differential signal between the output signal of the adding means and the output signal of the absolute value means. And an information demodulating means for demodulating an information signal formed on the recording thin film by comparing the signal with a second reference level. 26. A change which can be optically detected by irradiating light on a substrate having a track on an uneven surface composed of a first surface and a second surface having different optical positions with respect to the incident direction of a light beam. A recording member provided with a recording thin film layer, the track having an information recording area in the track direction and an address area having management information of the information recording area, and the track width of the first surface and the second area. The track width of the surface is substantially equal, and the address area is composed of an address pit row formed by isolating a part of the track formed of the first surface according to a predetermined code signal. A device for recording / reproducing an information signal by irradiating a light beam on a recording member having both the second surfaces as information recording areas, the optical system for irradiating the light beam on the recording member, The light bee A tracking error detecting means for detecting a deviation amount between the track and the light beam on the recording member based on the reflected light or the transmitted light from the recording member, and an output signal from the tracking error detecting means. Tracking control means for moving the light beam so that the light beam scans the track, and the tracking control means depending on whether the tracking is performed on the first surface or the second surface of the track. Tracking inversion means for inverting the polarity of the tracking level, signal level comparison means for changing the reference level in at least two steps according to the inversion polarity of the tracking inversion means, and demodulating the signal from the signal level comparison means. An optical information recording / reproducing apparatus having a demodulation unit for specifying address information.