KR100194048B1 - Disc determination device and method - Google Patents

Abstract

A disc reproducing apparatus having reproducing systems of CD and DVD having different synchronizing signals, wherein the CD reproducing system includes a CD synchronizing detection unit and the DVD reproducing system includes a DVD synchronizing detection unit, and the output of the synchronizing detection units is inspected after the disc is mounted. When the CD synchronization signal is detected, the CD playback system is selectively driven to perform the CD playback mode. When the DVD synchronization signal is detected, the CD playback system is selectively driven to perform the DVD playback mode.

Description

Disc determination device and method

The present invention relates to an apparatus and method for recording / reproducing a disc, and more particularly, to an apparatus and method for automatically determining the type of a disc to be inserted in a system for playing CDs and DVDs.

Generally, a representative disc as an optical disc for performing a non-contact reading by using a laser beam is a compact disc (hereinafter referred to as a CD). However, the current disc recording and reproducing apparatus is in need of high speed, overwrite, and high density (large capacity). On the other hand, digital image compression technology is also a trend that the MPEG (Moving Picture Experts Group) compression method is practical. Accordingly, digital disc media represented by Digital Video Discs (hereinafter referred to as DVDs) will emerge as a core medium of multimedia storage.

Fig. 1 shows a block configuration of a DVD player, where the disk 20 is a high density optical disk, which can be a DVD. In addition, it is assumed that the pickup unit 111 is a short wavelength optical head, and the numerical aperture of the objective lens is 0.6 and the red semiconductor laser wavelength is used. The signal amplifier 112 converts the optical signal output from the pickup unit 111 into an electrical signal and amplifies the signal. The demodulator and corrector ECC decoder 113 demodulates the modulated signal output from the signal amplifier 112 and corrects an error generated during the reproduction process. The servo controller 114 controls the pickup unit 11 by inputting the output of the signal amplifier 112 (focusing tracking error signal) and the demodulation and correction unit 113 (Contant Linear Velocity control signal). A system decoder 116 decodes a DVD data stream output from the demodulation and correction unit 113 and separately outputs the DVD data stream into a video elementary stream and an audio elementary stream. The video decoder 117 decodes the video data stream output from the system decoder 117 and converts it into a form of playable image data. The encoder 118 encodes video data output from the video decoder 117 in a corresponding video display method (NTSC or PAL) and outputs the video data to the display unit. An audio decoder 119 converts the encoded audio data stream output from the system decoder 116 into original audio data. The D / A converter 120 converts the data output from the audio decoder 119 into an analog audio signal and outputs the analog audio signal.

In the configuration of FIG. 1, a system controller for controlling the overall operation of the disc reproducing apparatus is not shown.

The DVD player having the above structure uses a modulation, error correction, and video encoding method different from that of a general CD player, and thus the signal processing method of the DVD and CD player is completely different. In the disc 20, the pit size and track pitch of the DVD and the CD are different, and the laser wavelength of the pickup unit 11 and the numerical aperture of the objective lens are also different.

It is important to reduce the size of the focusing spot in order to achieve high density in such a DVD recording / reproducing system. As a method of doing this, the wavelength of the first laser is shortened and the numerical aperture of the second objective lens is reduced. (NA) is increased, and the third method is to use a modulation method with excellent coding efficiency. At this time, the DVD uses a red laser semiconductor laser (650nm-635nm) among the above three methods, the numerical aperture (NA) of the objective lens is 0.6, and EFM-Plus is used as a modulation method. (Eight to Fourteen Modulation plus) is used.

In order to reproduce information on a high density optical disc, the optical pickup unit 111 must be able to form a small optical focus. The diameter of the optical focus is proportional to the wavelength of light λ as shown in FIG. 2 and inversely proportional to the numerical aperture NA of the objective lens. As described above, the present semiconductor laser wavelength has a lower limit of about 635 nm. In general, DVD uses a laser wavelength of 650nm as standard, and CD uses a 780nm laser wavelength. On the other hand, in the numerical aperture NA of the objective lens, since the CD is 0.45 while the DVD is 0.6, the optical focal diameter of the DVD is about 60% or more of the optical focal diameter of the CD. Thus, the DVD can obtain a reproduction signal equivalent to that of a CD on an optical disc of about 2.6 times the recording density of the CD. The DVD can realize the improvement of the reproduction waveform by the actual circuit processing, so that the DVD can have a recording density of about 4.2 times that of the CD as shown in FIG.

The characteristics between the DVD and the CD having the above characteristics are shown in Table 1 below.

CD DVD Remarks Disc diameter 120 mm 120 mm DVD is double sided multi layer Disc thickness 1.2 mm 0.6mm Recording capacity 640Mbyte 4.7Gbyte For single-sided tomography Laser wavelength 780 nm 650 nm Numerical aperture of the objective lens 0.45 0.6 Minimum fitting size 0.9 μm 0.4 μm Track pitch 1.6 μm 0.74μm Modulation method EFM EFM-plus Error correction method CIRC RS-PC

In Table 1, it can be seen that the CD and DVD having the same disc diameter have many differences. However, since the accumulation of the vast soft resources of the CD cannot be ignored, compatibility with the CD and the DVD is very important. One of the major reasons that the compatibility between the DVD and the CD is hindered is that a separate optical pickup must be used. In other words, in order to reproduce the information on the disk, a part of the optical system is configured according to the thickness of the disk. Therefore, the object lens is designed according to the thickness of the disk. Therefore, when the thickness of the disk deviates from the design value, spherical aberration occurs and convergence of the optical focus is lowered. In other words, this means that the DVD has a thickness of 0.6 mm while the CD has a thickness of 1.2 mm, so that two discs cannot be played by one pickup unit. Therefore, a problem arises in that a separate optical pickup unit must be used for the compatibility of the CD player and the DVD player.

In order to solve the above problems, a two-focal two-way optical pickup unit of CD and DVD has been proposed. The optical pickup unit as shown in FIG. 4 solves the problem caused by the disc thickness difference by forming both the optical focus for the DVD and the optical focus for the CD at an optical axis direction. The principle of the two-way optical pickup as shown in FIG. 4 is to overlap two types of lens operations using a hologram. The objective lens numerical aperture of the pick-up apparatus is 0.6 in accordance with the DVD standard. However, a hologram is arranged in which a part of the light in the center portion thereof is refracted like a lens by diffraction. Therefore, the light that is not diffracted in the hologram is converged by an objective lens having a numerical aperture of 0.6 to form an optical focus of the DVD, and the diffracted light has a composite lens numerical aperture of 0.4 with the hologram and the object and a CD having a thickness of about 1.2 mm. The hologram is formed to suit.

Therefore, when using the optical pickup as shown in FIG. 4, the optical focus for the CD is formed at a position farther than the optical focus for the DVD. In this case, the photodetector is disposed on the photodetector so that a reflection image of the optical focus converged on the disk can be formed. Therefore, when the DVD is reproduced, the optical focus for DVD is converged on the disc, and the optical focus for CD is shifted, resulting in a blurry image in which the focus is not matched. Thus, although the image of the optical focus for the DVD is formed on the photodetector, the reflected light at the optical focus for the CD is diffused to a wide range so as not to give external impact to the reproduction of the DVD. In addition, at the time of CD playback, the DVD is reversed.

However, in the case of a system having a pickup device capable of simultaneously playing a DVD and a CD in an optical disc player or a pickup device capable of independently playing a DVD and a CD, the type of disc to be inserted can be determined. Must be able to operate in Discrimination of the DVD and the CD can be implemented in various ways. That is, there may be a method of determining whether the inserted disc is a DVD or a CD by comparing the magnitude of the focus error detection signal of the optical focus reproduced by the optical pickup or by comparing the magnitude of the RF signal according to the pit size.

In addition to the above method, there may be a method of determining the type of the mounted disc using the synchronization pattern. Since the CD and the DVD use different sync codes, the CD and DVD can automatically determine the type of the inserted disc by analyzing the sync codes detected in the specific mode.

Accordingly, an object of the present invention is to provide an apparatus and method for automatically determining the type of a disc inserted in a system for reproducing a plurality of disc types.

Another object of the present invention is to detect and analyze a sync pattern of a mounted disc in an initial driving mode in a system for playing DVDs and CDs, to determine the type of mounted disc, and to automatically set a mode for playing the determined disc. It is to provide an apparatus and method that can be.

Disc reproducing apparatus according to an embodiment of the present invention for achieving the above object comprises a reproduction system of the CD and DVD having different synchronization signals, the CD reproduction system and the DVD reproduction system has a synchronization detection unit, When the CD sync signal is detected after mounting detection, the CD playback system is selectively driven to perform the CD playback mode, and when the DVD sync signal is detected, the DVD playback system is selectively driven to perform the DVD playback mode.

1 is a diagram showing the configuration of a digital video disc reproducing apparatus;

2 is a view for explaining the relationship between the wavelength of light, the numerical aperture of the objective lens, and the optical focal diameter in the disc reproducing apparatus;

3 is a diagram for explaining the relationship between bits and optical focus for digital video discs and compact discs;

4 is a diagram for explaining the principle of a bifocal two-way optical pickup.

5 is a diagram showing a configuration for determining the type of a disc loaded in a playback apparatus according to an embodiment of the present invention;

FIG. 6 is a diagram illustrating a characteristic of detecting a CD frame synchronization signal in order to determine the type of disc in the embodiment of FIG.

FIG. 7 is a diagram showing a sector format of data recorded on a DVD and DVD sync patterns.

FIG. 8 is a diagram showing a characteristic of detecting a DVD frame synchronization signal in order to determine the type of a disc in the embodiment of FIG.

9 is a diagram illustrating a configuration for detecting a frame synchronization signal in the embodiment of FIG.

10A and 10B are flowcharts showing the operation of determining the type of the disc loaded in the disc reproducing apparatus according to the embodiment of the present invention.

FIG. 5 is a diagram showing a configuration for automatically determining the type of a disc mounted in a disc system according to an embodiment of the present invention, which includes a CD player and a DVD player. In this case, it is assumed that the optical pickup 111 uses an optical pickup unit for both CD and DVD. The RF receiver 512 amplifies and outputs the weak optical signal reproduced by the optical pickup 111. At this time, the RF signal output from the RF receiver 512 is a signal reproduced from a CD or DVD.

First, referring to the CD reproduction system, referring to the CD reproduction system, the CD equalizer 513 equalizes and outputs an RF signal of a CD band from an RF signal output from the RF receiver 512. The CD signal processor 514 demodulates the modulated data stream output from the CD equalizer 513, and corrects and outputs an error generated in this process. The audio processor 515 signals and outputs the data output from the CD signal processor 514.

Second, referring to the DVD playback system, the DVD equalizer 516 filters the DVD signal RF signal from the received RF signal and then outputs the equalized signal. At this time, the DVD band is a broadband including a CD band. The DVD signal processor 517 receives the data stream of the DVD band output from the DVD equalizer 516, demodulates the modulated data, and corrects an error generated in this process. The DVD signal processor 517 corresponds to the demodulation and correction unit 113 of FIG. The A / D decoder 518 separates the video data and the audio data from the data output from the DVD signal processor 517 and performs signal processing to output the same. The A / V decoder 518 corresponds to the system decoder 116, the video decoder 117 and the audio decoder 119 of FIG.

As described above, the disc reproducing apparatus according to the embodiment of the present invention has a CD player and a DVD player, and the optical pickup 111 uses a two-way optical pickup unit capable of playing CDs and DVDs. Therefore, when a disc is mounted in the disc reproducing apparatus, it is necessary to determine whether the mounted disc is a CD or a DVD and selectively drive the corresponding reproducing system. To this end, a CD sync detector 521 is provided inside the CD signal processor 514 and a DVD sync detector 522 is provided inside the DVD signal processor 517. The control unit 511 determines the type of the loaded disc according to whether the CD frame sync pattern or the DVD frame sync pattern output from the CD sync detector 521 or the DVD sync detector 522 detects and drives the corresponding playback system.

As described above, the CD and the DVD have different types of frame synchronization patterns. Therefore, the disc reproducing system including the CD reproducing system and the DVD reproducing system can determine the type of disc by examining the frame synchronization pattern recorded on the disc. Here, the characteristics of the CD frame sync pattern and the DVD frame sync pattern will be described.

First, a frame synchroinzation pattern of the CD uses a pattern not used for modulated data. This synchronization method can reliably synchronize as long as no bit error occurs. The data recorded on the CD is modulated by EFM (Eight to Fourteen Modulation) method, which converts 8-bit data into 14-bit data and combines patterns of the shortest 3-bit (3T) and the maximum 11-bit (11T) lengths. This is possible. Thus, the sync pattern of the CD uses 1000000000010000000000100 _B (11T + 11T + 2T) as in FIG. 6A, which is not used as data. The CD frame sync pattern as shown in FIG. 6A is recorded on the CD in the form as shown in FIG. 6B or 6C. The format of data recorded on the CD is configured as shown in 6d of FIG. In this case, when the CD frame format is configured as shown in 6d of FIG. 6, the CD sync detector 521 detects and outputs a CD frame sync signal in a sync pattern period as shown in 6e of FIG. do. The CD sync detector 521 having the configuration as shown in FIG. 9 outputs a CD frame sync signal to the controller 511 when the frame sync pattern is detected.

Second, referring to the DVD frame sync pattern, the DVD frame sync pattern also uses a pattern that is not generated in the modulated data. The modulation method used for the DVD uses EFM-plus (Eight to Fourteen Modulation plus). In the DVD playback system using the EFM-plus modulation scheme as described above, the pattern of pure data is 11T (100000000001 _B ) at maximum. Therefore, the DVD frame sync pattern commonly uses a pattern that is not used in the pure data, and in such a case, the above pattern should exceed at least 12T. In addition, a plurality of sync patterns are used in the DVD, and these sync patterns are combined and used in an appropriate manner. At this time, these sync patterns have a specific pattern that does not use the data pattern as described above.

In the embodiment of the present invention, it is assumed that a pattern commonly used for the synchronization synchronization patterns is 14T (hereinafter referred to as a synchronization pattern), and these common patterns are assumed to be located at the lower 14-bit positions of each synchronization pattern.

FIG. 7 illustrates one sector format as an example in which a frame sync pattern and data of a DVD are stored. In FIG. 7, SP denotes synchronization patterns, and D1-Dn denotes pure data. In addition, in FIG. 7, a1-a2 indicates the length of a sync pattern, b1-b2 indicates the length of data, and c1-c2 indicates the length of a sync frame. , E denotes two sync frame lengths. The data length b has a length b >> a which is much larger than the length a of the sync pattern. In FIG. 7, F denotes the number of columns of two frame sinks constituting a sector. Accordingly, it can be seen that the size of one sector of the DVD becomes F * E [= 2c * F = 2 (a + b) * F].

The sector format recorded on the DVD has the form as shown in FIG. 7, wherein the synchronization pattern in the sector format is configured as shown in FIG. 8A. Here, the length of the sync pattern is composed of a bit, and the lower bits of the sync pattern have 14T in common as described above. Therefore, the plurality of synchronization patterns used for the DVD have the lower 14 bits having the same value, and the upper bits except for this have different values. As shown in 8b and 8c of FIG. 8, the data transfer time between the DVD frame sync pattern and the DVD frame sync pattern is 1.2 ms.

The CD synchronous detection unit 521 for detecting the CD frame synchronization pattern as described above and the DVD synchronous detection unit 522 for detecting the DVD frame synchronization pattern can be configured as shown in FIG. Referring to FIG. 9, the CD sync detector 521 stores a CD frame sync pattern as shown in FIG. 6A in the reference register 92, and the DVD sync detector 522 stores a DVD frame as shown in FIG. 8 in the reference register 92. Common data of the synchronization pattern is stored. The data stream is input to the input register 91 and shifted out.

The comparator 93 for comparing the parallel output bit data of the input register 71 and the parallel output bit data of the reference register 92 outputs a result of the comparison in bit units. Then, the synchronization signal detection unit 94 generates a signal for determining whether or not a frame synchronization signal is detected by logically combining the comparison data output from the comparator 93. In this case, the synchronization signal detection unit 94 may use a gate circuit. When all of the comparators 93 output high logic signals during synchronization detection, the synchronization signal detection unit 94 may use an AND gate.

When the controller 511 detects the initial disk mounting, the controller 511 sets the initial driving mode. In this case, the control unit 511 becomes the CD mode or the DVD mode. At this time, if the control unit 511 sets the CD mode to the initial operation mode, the CD frame synchronization pattern can be detected normally when the mounted disc is a CD. However, if the DVD is loaded while the CD mode is set, the CLV servo is applied but the frame synchronizing signal cannot be detected. Then, the control unit 511 converts the initial operation mode to the DVD mode, and in this case, the DVD synchronous detection unit 522 can detect the DVD frame synchronization signal.

In contrast to the above, that is, if the initial operation mode is set to the DVD mode, the DVD frame synchronization pattern can be detected normally when the loaded disc is a DVD. However, if the CD is loaded while the DVD mode is set, the CLV servo is applied but the frame synchronizing signal cannot be detected. In this case, the control unit 511 converts the initial operation mode to the CD mode, and in this case, the CD synchronization detection unit 521 can detect the CD frame synchronization signal.

In the embodiment of the present invention, when the disc is loaded, the initial operation mode is set to the CD mode, the CD frame synchronization pattern is detected, and the CD playback mode is continuously detected when the CD frame synchronization pattern is detected, and the CD frame synchronization pattern is not detected. In this case, it is assumed that the DVD playback mode is continuously executed by detecting the DVD frame synchronization pattern by converting to the DVD mode.

10A and 10B are flowcharts illustrating a process in which the controller 511 determines a type of a disc and selects and plays a corresponding play mode according to an embodiment of the present invention.

Referring to FIG. 10A, the controller 511 checks whether a disk is mounted. First, the controller 511 checks the state of the input unit 510 to check the on / off state of the tray. That is, when the tray is turned on / off, the controller 511 detects this in steps 1011 and 1013 of FIG. 10A and determines that the disk is mounted. The controller 511 controls the servo controller (not shown) in step 1015 to perform the focusing operation of the optical pickup 111. In this case, since the optical pickup 111 is a two-way optical pickup unit that can be used for both CD and DVD, the optical pickup 111 controls the servo controller to perform a CD pickup function. In step 1015, the controller 511 turns the focus of the optical pickup 111 up and down, and checks whether a focus lock is performed in step 1017. In this case, if the focus lock is not performed, the controller 511 detects this in step 1017, and determines that the disc is not loaded in step 1019 and processes it. In this case, the tray is turned on / off without the user loading the disc.

However, if it is detected that the focus lock is made in step 1017, since the disk is mounted on the tray, the control unit 511 rotates the mounted disk by controlling the servo control unit in steps 1021 and 1025. tracking servo) and CLV servo on. At this time, the servo controller rotates the disk by driving a spindle motor under the control of the controller 511 and performs a tracking servo so that the optical pickup 111 can accurately follow the track of data. At this time, when the tracking servo is completed, the rotation speed of the disk is controlled by controlling the spindle motor to the CLV mode of the CD playback mode. In this state, the CD CLV mode is set to prepare for the CD frame synchronization signal detection operation.

When the CD CLV servo is turned on, the controller 511 receives the output of the CD sync detector 521 in step 1027 and checks whether a CD frame sync signal is detected. In this case, the CD synchronous detection unit 521 inputs the filtered and equalized data streams into the CD band, and compares the input data stream with previously stored CD frame sync pattern data. At this time, the CD frame synchronization pattern stored in the reference register 92 is a unique pattern (11T + 11T + 2T) having a different form from the data in the data area recorded on the CD. Accordingly, the CD synchronization detecting unit 521 compares the CD frame synchronization pattern with the received data stream and outputs the CD frame synchronization signal when the pattern having the same value is detected.

In this case, when the loaded disc is a CD, the form of the synchronization signal output from the CD sync detection unit 521 is generated at a 13.3 ms period as shown in 6e of FIG. 6. Then, the controller 511 detects that the CD frame synchronization signal is detected in step 1027 and repeats this operation until the number of CD frame synchronization signals set in steps 1029 and 1031 are detected. The number of times of detecting the CD frame synchronizing signal is set to the number of times to determine that the loaded disc is a CD. When the set number of CD frame synchronization signals is detected, the control unit 511 sets the optical pickup 111 as a CD pickup unit in step 1033 and resets the CLV servo for CD playback, and then in step 1035 the DVD signal processor 517. And the A / V decoder 518 to deactivate the DVD playback system, and to control the CD signal processing section 514 and the audio processing section 515 to activate the CD playback system and perform the CD playback mode.

However, if the CD frame synchronization signal is not detected in step 1027, the controller 511 checks whether the set time has elapsed in step 1037. After the CD CLV servo is turned on, the controller 511 waits for the CD frame synchronization signal to be detected for a predetermined time. If the CD frame synchronization signal is not detected during this time, the controller 511 determines whether the loaded disc is a DVD. . In this case, the setting time may be a time for detecting several CD frame synchronization signals.

If the CD frame synchronization signal is not received during the set time, the control unit 511 controls the optical pickup 111 to play the information on the DVD disc by changing to the DVD mode in step 1039 of FIG. 10B. Subsequently, after performing steps 1049 and 1051 of FIG. 10B to control the focusing servo and tracking servo by controlling the servo control unit, the DVD CLV servo is turned on in step 1053. The servo controller then controls the spindle motor in the DVD CLV mode to control the rotational speed of the disc. In the above state, the DVD CLV mode is set when the disc is loaded, and it is assumed that the inserted disc is a DVD, and then the frame sync signal detection operation is prepared.

When the DVD CLV servo is turned on, the controller 511 receives the output of the DVD sync detector 522 in step 1055 to check whether a DVD frame sync signal is detected. In this case, the DVD synchronous detection unit 522 inputs a data stream filtered by the DVD band and equalized, and compares the input data stream with a pre-stored DVD frame sync pattern. In this case, the reference data stored in the reference register 92 is a unique pattern 14T having the DVD frame synchronization patterns in common and having a different form from the data in the data area recorded on the DVD. Accordingly, the DVD synchronous detection unit 522 compares the sync pattern with the received data stream and outputs it as a DVD frame sync signal when detecting a pattern having the same value.

In this case, when the loaded disc is a DVD, the type of the synchronization signal output from the DVD synchronous detection unit 521 is generated in a 1.2 ms period as shown in 8c of FIG. 8. Then, the controller 511 detects that the DVD frame sync signal is detected in step 1055 and repeats this operation until the number of DVD frame sync signals set in steps 1057 and 1059 are detected. The number of times of detecting the DVD frame synchronizing signal is set to the number of times to determine that the loaded disc is a DVD. When the set number of DVD synchronization signals is detected, the control unit 511 sets the optical pickup 111 as a pickup unit for DVD in step 1061, resets the CLV servo for DVD playback, and the like, in step 1063. The A / V decoder 518 is controlled to activate the DVD playback system to perform the DVD playback mode, and the CD signal processor 514 and the audio processor 515 are controlled to deactivate the CD playback system.

As described above, in the embodiment of the present invention, when a disc is loaded in a disc reproducing system capable of simultaneously reproducing a CD and a DVD, a CD reproducing mode is first performed to check whether a disc detects a CD frame synchronizing signal of the disc, and to synchronize a CD frame. An embodiment in which a DVD frame synchronizing signal is detected when no signal is detected is described assuming.

However, as another embodiment of the present invention, the DVD play mode may be first performed to check the presence or absence of a DVD frame synchronization signal of a disc, and to detect a CD frame synchronization signal when the DVD frame synchronization signal is not detected. In this case, when the DVD frame synchronizing signal is detected, the loaded disc is judged to be DVD, and the DVD playback system is activated to perform the DVD playback mode. If the DVD frame synchronizing signal is not detected during the set time, the DVD drive mode is changed to CD mode, the CD frame synchronizing signal is detected, the mounted disc is regarded as a CD, and the DVD playback system is activated to activate the DVD play mode. Just do it.

In addition, in the embodiment of the present invention, a single pickup device capable of playing both CD and DVD by the optical pickup unit is described as an example, but a disc playback system including a CD-only pickup device and a DVD-only pickup device is provided separately. The same can be applied. In this case, when the disc is loaded, it first analyzes the received data stream generated from the CD-only pickup device and checks whether the CD frame sync signal is detected. In this case, if the CD frame sync signal is detected, the CD play mode is performed. If the synchronization signal is not detected during the set time, the DVD playback mode may be performed by activating the DVD dedicated pickup device and selecting the DVD playback system.

As described above, the type of the disc to be inserted can be automatically determined by the apparatus for reproducing the plurality of discs. In particular, it is possible to accurately determine the type of the disc by detecting the presence or absence of a synchronization signal of the mounted disc, and there is an advantage in that the disc play mode can be automatically performed according to the determination progress.

Claims (4)

A disc reproducing apparatus having reproducing systems of CD and DVD having different synchronizing signals, wherein the CD reproducing system and the DVD reproducing system each have a synchronizing detection unit, and detect a synchronizing signal output from the synchronizing detection units when a disc is mounted. When the CD synchronization signal is detected, the CD playback system is selectively driven to perform a CD playback mode, and when the DVD synchronization signal is detected, the DVD playback system is selectively driven to perform a DVD playback mode. Optical disc player. In a disc reproducing apparatus having a two-focus optical pickup capable of reproducing CDs and DVDs having different synchronization signals and a CD reproducing system and a DVD reproducing system, the CD reproducing system and the DVD reproducing system each have a synchronous detecting unit, When the disc is detected, the optical pickup is controlled exclusively for the CD and the output of the CD sync detection unit is inspected to perform the CD play mode when the CD sync signal is detected, and when the CD sync signal is not detected for a predetermined time, And controlling a pickup exclusively for DVD, inspecting the output of the DVD synchronous detection unit, and performing a DVD playback mode upon detecting the DVD synchronous signal. In a disc reproducing apparatus having a two-focus optical pickup capable of reproducing CDs and DVDs having different synchronization signals and a CD reproducing system and a DVD reproducing system, the CD reproducing system and the DVD reproducing system each have a synchronous detecting unit, When the disc is detected, the optical pickup is controlled for DVD only and the output of the DVD synchronous detection unit is inspected to perform a DVD play mode when the DVD sync signal is detected, and when the DVD sync signal is not detected for a predetermined time, And controlling the pickup exclusively for the CD, checking the output of the CD sync detector, and performing a CD play mode upon detecting the CD sync signal. A two-focus optical pickup capable of reproducing CDs and DVDs having different synchronization signals, a CD player system and a DVD player system, wherein the CD player system and the DVD player system each have a synchronization detector. And analyzing a sync signal detected when a disc is loaded, performing a CD play mode by selectively driving a CD player when the CD sync signal is detected, and performing the CD play mode when the DVD sync signal is detected. An optical disc playback method, characterized in that the drive mode is selectively driven to perform a DVD playback mode.