JPH09102147A - Disk recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a disk recorder capable of improving reliability when recording data in an optical disk by setting the output of laser beams to a prescribed level immediately after supplying the optical disk and bringing it closer to the level decided, based on the temperature of the optical disk detected by a temperature sensor thereafter. SOLUTION: When a magneto-optical disk 5 is supplied to this disk recorder 1 composed of an optical pickup 2, the temperature sensor 3 and an output power adjustment circuit 4, the output power adjustment circuit 4 selects an initial setting signal S2 in a level switching part 6 by a disk-in signal S1 and controls a laser diode 13 so as to turn the laser beam LA12 for irradiating the magneto-optical disk to power corresponding to the initial setting signal S2. Then, after the prescribed time when the temperature of the magneto-optical disk 5 and the disk recorder 1 almost match, the temperature sensor 3 is selected in the level switching part 6. Thus, the disk recorder 1 capable of improving the reliability when recording the data in the magneto-optical disk 5 is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[Table of Contents] The present invention will be described in the following order. TECHNICAL FIELD The invention belongs to the related art (FIG. 4) Problem to be solved by the invention (FIG. 4) Means for solving the problem (FIG. 1) Embodiment of the invention (FIGS. 1 to 3)

[0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk recording apparatus, and is suitable for application to, for example, a disk recording apparatus using a magneto-optical disk as an optical disk.

[0003]

2. Description of the Related Art Conventionally, a so-called magnetic field modulation system has been used as one of the systems for recording predetermined data on a magneto-optical disk by using this type of disk recording / reproducing apparatus.
That is, the magnetic film formed on the surface of the magneto-optical disk is irradiated with laser light, and the irradiation area of the laser light is heated to a temperature of about 180 ° C. (hereinafter, the coercive force of the magnetic film becomes zero). (It is called Kyrie temperature)) After that, a magnetic field of N pole or S pole is applied to the laser beam irradiation region of the magnetic film (hereinafter, referred to as laser beam irradiation region), and binarization is performed according to the magnetic field of the N pole or S pole. Data of "1" or "0" is recorded.

However, according to this data recording method,
During data recording, if the temperature of the magneto-optical disk itself is relatively high, the area of the magnetic film that is wider than the laser irradiation area will be higher than the Curie temperature. Data is also recorded in the warmed area. As a result, in this magneto-optical disk, data may be overlapped and recorded in adjacent data recording areas (hereinafter referred to as data recording areas).

Further, when the temperature of the magneto-optical disk itself is relatively low, the region heated to the Curie temperature or higher is smaller than the laser light irradiation region in the magnetic film, and therefore the temperature is raised to the Curie temperature or higher. Data is recorded only in the area. As a result, unreadable data may be recorded on the magneto-optical disk because the data recording area is too small.

Therefore, in this disc recording / reproducing apparatus, when the temperature of the magneto-optical disc itself is relatively high or relatively low, duplicated data or unreadable data is recorded in the data recording area of the magneto-optical disc. Therefore, it may be difficult to obtain a sufficient reproduction signal.

Therefore, in this disc recording / reproducing apparatus, a temperature sensor is provided near one surface of the magneto-optical disc,
By detecting the temperature of the magneto-optical disk itself by using this temperature sensor, the output of laser light (hereinafter referred to as output power) is adjusted based on the detected temperature. In other words, this disk recording / reproducing apparatus has a temperature (hereinafter, referred to as a temperature detected by a temperature sensor,
(This is called the sensor detection temperature) is relatively high,
Laser light is output at a level lower than when the sensor detection temperature is the standard temperature. On the other hand, when the sensor detection temperature is relatively low, the laser light is output at a higher level than when the sensor detection temperature is the standard temperature. In this way, by adjusting the output power according to the temperature of the magneto-optical disk, the data is recorded in the optimum state based on the output power.

Here, in actuality, the temperature change inside the disk recording / reproducing apparatus is shown in the graph of FIG. First, the characteristic point group A indicates the temperature change measured at the upper part of the cartridge which is used to protect the magneto-optical disk.
Characteristic point group B represents the temperature change measured at the bottom of the cartridge. Further, the characteristic point group C indicates the temperature change measured by the circuit board arranged above the magneto-optical disk, and the characteristic point group D indicates the temperature change detected by the temperature sensor.

In this case, the temperature of the magneto-optical disk itself is 26
When this magneto-optical disk is supplied to the inside of the disk recording / reproducing apparatus at time T = 0 at about [° C.], the characteristic point groups A and B gradually approach the characteristic point group C. This means
It shows that the temperature of the upper part of the cartridge and the temperature of the lower part of the cartridge increase with the passage of time so as to approach the temperature of the circuit board.

On the other hand, since the temperature sensor detects the temperature of the magnetic film of the magneto-optical disk without making contact with the magneto-optical disk, the temperature detected by the sensor is about 36 [° C.] at time T = 0, that is, the disk. This indicates the temperature inside the recording / reproducing apparatus, which is higher than that of the magneto-optical disk of about 26 ° C. Further, after the time T = 4 after the magneto-optical disk is supplied to the inside of the disk recording / reproducing apparatus, the characteristic point group D comes to follow the intermediate position between the characteristic point groups A and B. This means that the temperature detected by the sensor is almost the same as the temperature of the magneto-optical disk.

In this disk recording / reproducing apparatus, for example, when the temperature detected by the sensor is about 50 [° C.], the magneto-optical disk of about 25 [° C.] is supplied to the inside of the disk recording / reproducing apparatus immediately after the magneto-optical disk is supplied. Until the temperature of the disk itself and the temperature detected by the sensor match, data can be recorded with the output power adjustment range in the optimum state.

[0012]

By the way, according to the results of such an experiment, in this disk recording / reproducing apparatus, immediately after the magneto-optical disk is supplied to the inside of the apparatus,
It becomes difficult for the temperature sensor to accurately detect the temperature of the magneto-optical disk itself, which causes an error in the temperature of the magneto-optical disk with respect to the sensor detection temperature, which may result in an error in the adjustment of the output power. is there. On the other hand, immediately after the supply of the magneto-optical disc, after the time T = 4, the sensor detection temperature and the temperature of the magneto-optical disc itself substantially match, so that the output power is optimized based on the sensor detection temperature. Can be adjusted.

Therefore, in this disc recording / reproducing apparatus, for example, when the temperature detected by the sensor is about 50 [° C.], immediately after the magneto-optical disc having a temperature of about 0 [° C.] is supplied to the inside of the disc recording / reproducing apparatus. , The temperature difference between the sensor detection temperature and the temperature of the magneto-optical disk is too large even if the data is recorded on the magneto-optical disk, and it becomes difficult to adjust the output power within the range in which the data can be optimally recorded. There was a problem.

Further, in this disk recording / reproducing apparatus, immediately after the magneto-optical disk having a temperature higher than the sensor detection temperature is supplied into the disk recording / reproducing apparatus, the temperature between the sensor detection temperature and the temperature of the magneto-optical disk. If the difference is larger than the predetermined standard value, it becomes difficult to adjust the output power within the range in which data can be optimally recorded, as described above.

Therefore, in this disk recording / reproducing apparatus, during data recording, from immediately after the magneto-optical disk is supplied to the inside of the disk recording / reproducing apparatus until the temperature of the magneto-optical disk and the sensor detection temperature match. There was still a problem in recording data on the magneto-optical disk while maintaining a stable state.

The present invention has been made in consideration of the above points, and it is an object of the present invention to propose a disk recording apparatus capable of improving the reliability when recording data on an optical disk.

[0017]

In order to solve such a problem, according to the present invention, a laser light source for outputting a laser beam, a temperature detecting means for detecting the temperature of an optical disk, and a detection result of the temperature detecting means are used. Output power adjusting means for adjusting the output power of the laser light is provided, and the output power adjusting means sets the output power of the laser light to a predetermined first level immediately after the supply of the optical disk, and thereafter. The output power of the laser light is controlled to approach the second level determined based on the detection result of the temperature detecting means.

Immediately after the supply of the optical disc, the output power adjusting means sets the output power of the laser light output from the laser light source to a predetermined first level, and based on the output power from the laser light source at the first level. Second laser light is output by the laser light source, and then the output power of the laser light output from the laser light source is determined based on the detection result of the temperature detecting means.
By controlling so as to approach the level of the optical disc, even if the temperature difference between the temperature of the optical disc itself and the temperature detected by the temperature detecting means is large immediately after the supply of the optical disc, the conventional disc It is possible to minimize the error between the optimum output power as compared with the recording apparatus and the output power adjusted based on the detection result of the temperature detecting means.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings.

In FIG. 1, reference numeral 1 denotes a disk recording apparatus according to the embodiment as a whole, which comprises an optical pickup 2, a temperature sensor 3 and an output power adjusting circuit 4. At the time of data recording, in the output power adjusting circuit 4, the disk recording apparatus 1 whose internal temperature is, for example, about 50 [° C.]
When the magneto-optical disk 5 having a temperature of, for example, 0 [° C.] is supplied to the inside, a disk detecting section (not shown) sends a disk-in signal S1 to the level switching section 6.

The level switching unit 6 has a temperature switching unit 7, and a 2-input terminal 7A provided in the temperature switching unit 7
One of the input terminals 7A and 7B is connected to the temperature sensor 3 via a resistor R1 having a predetermined resistance value, and the other input terminal 7B is connected to a temperature setting unit (not shown). An output power correction unit 8 is connected to the output terminal 7C of the temperature switching unit 7, and one end of the capacitor C1 having a predetermined electrostatic capacity is grounded between the output terminal 7C and the output power correction unit 8. The other end is connected.

In this case, when the disc-in signal S1 is input from the disc detecting unit, the temperature-switching unit 7 of the level-switching unit 6 switches the contact to the input terminal 7A side based on the disc-in signal S1 so that the temperature is changed. The setting unit and the output power correction unit 8 are electrically connected. As a result, the temperature setting unit sends an initial setting signal S2 having a voltage value corresponding to the initial setting temperature to the output power correction unit 8.

On the other hand, in this state, the initial setting signal S2
The capacitor C1 is charged by the
1 is charged to steady state. At this time, the detection unit (not shown) detects the steady state of the capacitor C1 and then sends this to the temperature switching unit 7 as a detection signal. The temperature switching unit 7 switches a contact to the input terminal 7B side based on the detection signal and connects the other end of the capacitor C1 to the resistor R1 to form an integrating circuit.

In this integrating circuit, at this time, the voltage value according to the initial set temperature of about 25 [° C.] is increased with the passage of time so that the voltage value may match the voltage value according to the sensor detected temperature after a predetermined time. The voltage value according to the sensor detection temperature is changed based on a time constant (hereinafter, simply referred to as a time constant) determined by the capacitor C1 and the resistor R1 of the integration circuit. Here, the temperature change according to the actually changed voltage value is shown in the graph of FIG. In this case, the characteristic curve X shows the sensor detection temperature, and the characteristic curve Y shows the change over time of the initial set temperature.
It shows that the initial set temperature of about [° C.] rises with the passage of time, and coincides with the sensor detected temperature after the time determined based on the time constant.

As shown in FIG. 3, the characteristic curve Z has an internal temperature of the disk recording apparatus 1 of about 50 [° C.] and a light of about 25 [° C.] supplied to the inside of the disk recording apparatus 1. The time variation of the error from the temperature of the magnetic disk 5 itself is shown, which is affected by the internal temperature of the disk recording apparatus 1 and the temperature of the magneto-optical disk 5 itself rises with the passage of time. The temperature of the magneto-optical disk 5 itself coincides with the internal temperature of the disk recording apparatus 1 about 6 [minutes] after being supplied into the disk recording apparatus 1. Practically, in this integrating circuit, the time constant is selected based on the temperature characteristic which changes with the passage of time as shown by the characteristic curve Z.

When the magneto-optical disk 5 is supplied to the inside of the disk recording apparatus 1, the temperature switching section 7 of the level switching section 6 first receives the disk-in signal S1 from the disk detecting section, and the disk-in signal S1. The contact is switched to the input terminal 7A based on As a result, the temperature switching unit 7 is set to, for example, 25
An initial setting signal S2 having a voltage value according to the initial setting temperature of about [° C.] is input to the input terminal 7A. After that, the temperature switching unit 7 sends the initial setting signal S2 to the output power correction unit 8 via the capacitor C1.

The output power correction unit 8 uses the initial setting signal S2.
On the basis of the voltage value of, the target voltage value that provides the output power corresponding to the voltage value is obtained from the output power data table (not shown) provided inside, and the correction signal S3 having the target voltage value is subtracted. It is sent to the phase compensation unit 10 via the unit 9.

The phase compensator 10 phase-compensates the correction signal S3 and sends it to the voltage-current converter (hereinafter referred to as V / I converter) 11. The V / I converter 11 uses the correction signal S
The target voltage value based on 3 is converted into a laser input signal S4 having a current value corresponding to the target voltage value, and the laser input signal S4 is sent to the automatic laser power control (hereinafter referred to as ALPC) 12. The ALPC 12 is driven and controlled on the basis of the current value of the laser input signal S4, and causes the laser diode 13 of the optical pickup 2 to emit the laser light LA1 so as to have an output power of about 25 [° C.] according to the initial setting temperature.

In this case, in the optical pickup 2,
A laser beam LA11 having a light amount of several [%] of the laser beam LA1 having a predetermined light amount emitted from the laser diode 13 is incident on the output power detector 15 via the beam splitter 14. On the other hand, laser light LA1
After passing through the beam splitter 14, the laser beam LA12 having a light amount substantially equal to the light amount of the above is condensed by the objective lens 16 and the surface of a magnetic film (not shown) formed on one surface of the magneto-optical disk 5. To the laser beam with a predetermined beam diameter. Thus, the ALPC 12 adjusts the laser light LA12 emitted from the laser diode 13 so as to have an output power according to a temperature of about 25 [° C.], and irradiates a predetermined region of the magnetic film of the magneto-optical disk 5.

The output power detector 15 of the optical pickup 2 detects the light amount of the received laser light LA11,
A current value based on the light quantity of the laser light LA11 (that is, the laser light LA emitted from the laser diode 13).
The light reception signal S5 having the output power of 11) is sent to the current-voltage converter (hereinafter, referred to as I / V converter) 17 of the output power adjusting circuit 4. The I / V converter 17 converts the received light signal S5 into an output power signal S6 having a voltage value corresponding to the current value of the received light signal S5 and sends it to the subtractor 9.

In this case, in the output power adjusting circuit 4, a signal based on the temperature of the magneto-optical disk 5 is constantly sent from the level switching section 6, and the temperature switching section 7 of the level switching section 6 is initialized. When the signal S2 is sent, the detection signal of the capacitor C1 charged to the steady state by the initial setting signal S2, which has detected the steady state, is input. The temperature switching unit 7 switches the contact to the input terminal 7B side based on the input detection signal. As a result, the temperature sensor 3 provided near one surface of the magneto-optical disk 5 always detects the temperature near the magnetic film of the magneto-optical disk 5, and the temperature information signal S7 having a voltage value based on this sensor detected temperature. Is sent to the level switching unit 6.

The level switching unit 6 changes the voltage value based on the temperature information signal S7 based on the time constant, and sends the temperature signal S8 having the changed voltage value to the output power correction unit 8. Based on the voltage value of the temperature signal S8, the output power correction unit 8 obtains a target voltage value that gives an output power corresponding to the voltage value from the output power data table, and subtracts the correction signal S3 having the target voltage value. It is sequentially sent to the section 9. The subtraction unit 9 subtracts the voltage value based on the output power signal S6 from the target voltage value based on the correction signal S3, and outputs the control signal S9 having a voltage value for controlling the ALPC 12 so that the subtraction result becomes “0”. It is sent to the phase compensation unit 10.

The phase compensating section 10 phase-compensates the control signal S9 and sends it to the V / I converting section 11, and the V / I converting section 11
Converts the voltage value based on the control signal S9 into an output power control signal S10 having a current value corresponding to the voltage value, and
It is sent to the LPC 12. As a result, the ALPC 12 is drive-controlled based on the current value of the output power control signal S10, and the output power of the laser light LA1 emitted from the laser diode 13 of the optical pickup 2 is the target voltage value obtained by the output power correction unit 8. The laser light LA is adjusted to the laser diode 13 by adjusting the output power according to
Eject 1.

Further, the subtraction unit 9 is always input with the output power signal S6 corresponding to the output power of the laser beam LA11 emitted from the laser diode 13, and the correction signal S3 is input from the output power correction unit 8. Has been done,
The subtraction unit 9 changes the correction signal S3 to the output power signal S6.
Is subtracted and the control signal S9 based on this result is transmitted.

Thus, in this disk recording apparatus 1, from the time immediately after the magneto-optical disk 5 is supplied to the inside of the disk recording apparatus 1 until the temperature of the magneto-optical disk 5 and the temperature detected by the sensor are substantially equal to each other, the conventional method is used. Compared to the disk recording / reproducing apparatus described above, the error between the optimum output power for recording data on the magneto-optical disk 5 and the output power adjusted according to the sensor detection temperature can be minimized.

In the above structure, the disk recording apparatus 1 first emits the laser light LA12 based on the output power according to the initial set temperature immediately after the magneto-optical disk 5 is supplied to the inside of the disk recording apparatus 1. Magnetic disk 5
After setting the initial setting temperature, the initial setting temperature is changed to match the sensor detection temperature after a predetermined time determined based on the time constant, and the output power is changed according to the changed temperature. The magneto-optical disk 5 is irradiated with the base laser light LA12.

In this case, the disc recording apparatus 1 minimizes the error between the optimum output power and the output power adjusted according to the sensor detection temperature when recording data as compared with the conventional disc recording / reproducing apparatus. be able to.

According to the above structure, immediately after the magneto-optical disk 5 is supplied, the magneto-optical disk 5 is irradiated with the laser beam LA12 based on the output power according to the initial setting temperature to set the initial setting temperature. After that, the magneto-optical disk 5 is irradiated with the laser light LA12 based on the output power corresponding to the temperature that is changed so that the initial set temperature matches the sensor detection temperature after a predetermined time. Immediately after the magneto-optical disk 5 is supplied to the inside, even if the temperature difference between the temperature of the magneto-optical disk 5 and the sensor detection temperature is large, the optimum output power and the sensor detection are better than those of the conventional disk recording / reproducing apparatus. The error with the output power adjusted according to the temperature can be minimized, thus improving the reliability when recording data on the optical disk. It is possible to realize a Isku recording apparatus.

In the above-described embodiment, the case where the initial setting signal S2 initially set to the temperature of about 25 [° C.] is input to the temperature switching unit 7 of the level switching unit 6 during data recording will be described. However, the present invention is not limited to this, and the magneto-optical disk 5 to be recorded is used as the disk recording apparatus 1
The user is made to preset the initial temperature each time it is supplied to the inside, and the initial setting signal S2 corresponding to the initial setting temperature set by the user is input to the temperature switching unit 7 of the level switching unit 6. May be.

Further, in the above-mentioned embodiment, in the case of recording the data, the temperature switching section 7 of the level switching section 6 is supplied with the initial setting signal S2 which is initially set to a temperature of about 25 ° C. As mentioned above, the present invention is not limited to this, and the temperature switching unit 7 of the level switching unit 6 may be set to various preset temperatures such as preset initial setting temperatures within the guaranteed operating temperature range of the disk recording apparatus 1. The initial setting signal S2 corresponding to the above may be input.

Further, in the above-described embodiment, the output power correction unit 8 uses the voltage values of the input initial setting signal S2 and temperature signal S8 to set the target voltage value such that the output power corresponds to the voltage value. However, the present invention is not limited to this, and the output power correction unit 8 outputs an output according to the voltage values of the initial setting signal S2 and the temperature signal S8 by a predetermined correction formula. You may make it obtain | require the target voltage value used as power.

Further, in the above-mentioned embodiment, the case where the present invention is applied to the disk recording apparatus 1 for recording data on the magneto-optical disk 5 by using the magnetic field modulation method has been described, but the present invention is applied to this. The present invention is not limited to this, and may be applied to a disk recording device that records data on the magneto-optical disk 5 using an optical modulation method.

Further, in the above-described embodiment, when the temperature switching unit 7 switches the contact to the input terminal 7B side, the initial setting signal S2 charges the capacitor C1 to a steady state, and at this time, the detection unit detects the capacitor C1. The steady state of is detected and sent to the temperature switching unit 7 as a detection signal, so that the temperature switching unit 7 switches the contact to the input terminal 7B side based on the detection signal. However, the present invention is not limited to this, and for example, the output power correction unit 8, the subtraction unit 9, the phase compensation unit 10, the V / I conversion unit 11, and the ALPC 1 of the output power adjustment circuit 4.
When the initial setting signal S2 or the signal related to the initial setting signal S2 is input to any one of the two, it is detected that the initial setting signal S2 or the signal related to the initial setting signal S2 is input. Then, this may be sent to the temperature switching unit 7 as a detection signal, and the temperature switching unit 7 may switch the contact to the input terminal 7B side.

Further, in the above-mentioned embodiment, the case where the optical pickup 2 is used as the laser light source for outputting the laser light has been described, but the present invention is not limited to this, and a laser capable of recording data on the optical disk. Various other laser light sources may be used as long as they can output light.

Further, in the above-mentioned embodiment, the case where the temperature sensor 3 is used as the temperature detecting means for detecting the temperature of the optical disk has been described, but the present invention is not limited to this, and the inside of the disk recording apparatus 1 is described. Magneto-optical disk 5
Various other temperature detecting means may be used as long as they can be arranged in the vicinity and the temperature of the magnetic film formed on the magneto-optical disk 5 can be detected.

Further, in the above embodiment, the output power adjusting circuit 4 is used as the output power adjusting means for adjusting the output power of the laser light based on the detection result of the temperature detecting means.
However, the present invention is not limited to this, and various other output power adjusting means may be used if the output power of the laser light can be adjusted based on the detection result of the temperature detecting means. You may do it.

Further, in the above-mentioned embodiment, the case where the magneto-optical disk 5 is used as the optical disk has been described, but the present invention is not limited to this, and one surface is irradiated with laser light according to the recording data. If the recording data can be recorded by the above method, various other optical disks may be applied.

[0048]

As described above, according to the present invention, immediately after the supply of the optical disk, the output power adjusting means sets the output power of the laser light output from the laser light source to a predetermined first level, and The laser light is output from the light source based on the output power of the first level, and then the output power of the laser light output from the laser light source is brought close to the second level determined based on the detection result of the temperature detecting means. As a result, even if the temperature difference between the temperature of the optical disc itself and the temperature detected by the temperature detection means is large immediately after the supply of the optical disc, the disc recording device is more likely to be compared with the conventional disc recording device. The error between the optimum output power and the output power adjusted based on the detection result of the temperature detection means can be minimized, and thus, when data is recorded on the optical disk. It is possible to realize a disk recording apparatus capable of improving the reliability.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the configuration of a disk recording apparatus according to an embodiment of the present invention.

FIG. 2 is a graph showing temperature characteristics of a temperature that changes after setting an initial temperature and a temperature detected by a temperature sensor according to an embodiment of the present invention.

FIG. 3 is a graph showing changes in temperature difference between the temperature of the magneto-optical disk and the temperature detected by the temperature sensor according to the embodiment of the present invention.

FIG. 4 is a graph showing temperature characteristics inside a conventional disk recording / reproducing apparatus.

[Explanation of symbols]

1 ... Disk recording device, 2 ... Optical pickup, 3 ...
... Temperature sensor, 4 ... Output power adjustment circuit, 5 ... Opto-magnetic disc, 6 ... Level switching unit, 7 ... Temperature switching unit, 8 ... Output power correction unit, 9 ... Subtraction unit, 10 ...
Phase compensation unit, 11 ... V / I conversion unit, 12 ... ALP
C, 13 ... Laser diode, 14 ... Beam splitter, 15 ... Output power detector, 16 ... Objective lens, 17 ... I / V converter, R1 ... Resistor, C1 ...
... capacitors.

Claims (2)

[Claims] 1. A disk recording apparatus for recording the recording data on the one surface of the optical disk by irradiating the one surface of the optical disk with laser light according to the recording data, and a laser light source for outputting the laser light. The output power adjusting means comprises: temperature detecting means for detecting the temperature of the optical disk; and output power adjusting means for adjusting the output power of the laser light based on the detection result of the temperature detecting means. Immediately after the supply of the optical disk, the output power of the laser light is set to
And the output power of the laser beam is controlled so as to approach a second level determined based on the detection result of the temperature detecting means. 2. The output power adjusting means has an integrating circuit composed of a capacitor and a resistance, and the first level is changed to the second level based on a time constant determined by the capacitor and the resistance. The disk recording apparatus according to claim 1, wherein a time for approaching the disk is determined.