JPH05290376A - Optical information recording and reproducing device - Google Patents

Abstract

PURPOSE:To provide an optical information recording and reproducing device which can perform stable recording and/or reproducing and having versatility for various optical information recording medium. CONSTITUTION:Information is recorded by irradiating a optical information recording medium 202 with a laser beam, and/or information is reproduced by irradiating with the laser beam and detecting a reflected light from the optical information recording medium 202 with sensors 28-30. Also, this device is provided with means 208, 209, and 210 in which the reflected light from the prescribed position on the optical information recording medium 202 is detected with the sensors 28-30, and power control of a laser beam irradiating means 204 is performed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical information recording / reproducing apparatus for recording and / or reproducing information on an optical information recording medium. In particular, the present invention relates to an apparatus suitable for an optical card recording / reproducing apparatus that records / reproduces information while reciprocally moving an optical head and various optical cards.

[0002]

2. Description of the Related Art Conventionally, various types of media such as optical disks, cards, and optical tapes have been known as a form of a medium for recording and reproducing information by using light. Each of these has its own characteristics, and they are used properly according to their purpose and application. Among them, the optical card is easy to manufacture, has good portability,
It is expected that applications will become more and more widespread in the future by taking advantage of features such as good accessibility.

In these optical cards, a plurality of tracking tracks are provided in parallel with the long side of the card, and it is general that an information track for recording information is provided between the two tracking tracks. The tracking track is used as a guide for auto-tracking (AT) that controls so as not to deviate from a predetermined information track when scanning a light spot for recording / reproducing information at the time of recording / reproducing information. In actual recording / reproduction of information, auto focus (AF) is also used to control the light spot so that the light spot is correctly focused on the surface of the recording medium. These AT and AF are general techniques that have been widely used in the past in devices that record and reproduce information using light.

FIG. 8 is a schematic plan view of such an optical card 101, in which 102 is an information recording area, 103 is an information track, 104 and 104 'are track selection areas respectively, and 105 is a home position of a light spot. ..

FIG. 4 is a block diagram showing a schematic configuration of a conventional example of an information recording / reproducing apparatus for recording information on the optical card 1 and reproducing the information recorded on the optical card as described above. ..

In FIG. 4, reference numeral 19 denotes a recording / reproducing device, to which a CPU 9 as a host control device is connected. In the recording / reproducing apparatus 19, 14 introduces the optical card 1 into the recording / reproducing apparatus via a transport mechanism (not shown),
It is a drive motor for reciprocating in the R direction at a predetermined recording / reproducing position and further discharging it to the outside of the apparatus.

Reference numeral 17 denotes a light beam irradiation optical system including a light source, which forms a light spot on the optical card 1 at the time of recording and reproducing information. Three light spots are formed on the optical card 1. 28 to 30 are photodetectors,
The reflected lights of the three light spots on the optical card 1 can be received respectively. 15 is a light beam irradiation optical system 1
An AF actuator for performing AF by driving a part of 7 to move the focal position of the light spot on the optical card surface in the Z direction, that is, the direction perpendicular to the optical card surface.
Reference numeral 6 is an AT for driving a part of the optical system 17 of the light beam irradiation system to move the light spot on the optical card surface in the Y direction, that is, in the direction orthogonal to both the R direction and the Z direction to perform AT. It is an actuator.

The light beam irradiation optical system 17 and the photodetector 2
The optical head 18 includes 8 to 30, the AF actuator 15 and the AT actuator 16. Reference numeral 13 denotes a drive motor for moving the optical head in the Y direction to access the light spot to a desired track on the optical card.

The drive motors 13 and 14 are controlled by a microprocessor (MPU) 10. Reference numeral 71 is an encoder coupled to the drive motor 14, and outputs a pulse every time the drive motor 14 rotates by a predetermined angle. Since the rotation angle of the drive motor and the amount of movement of the optical card 1 in the R direction have a constant relationship, the position of the light spot on the optical card in the R direction can be detected by counting the output pulses of the encoder 71. You can Reference numeral 72 denotes a waveform shaping circuit, which shapes the output pulse of the encoder 71 so that the MPU 10 can receive it.

The outputs of the photodetectors 28 to 30 are AT / A.
It is input to the F control circuit 11, and based on this, the control circuit uses the AF actuator 15 and the AT actuator 16 described above.
To perform AF and AT. The photodetector 28-
The output of 30 is also input to the modulation / demodulation circuit 12, the read information is demodulated, and the demodulated signal is sent to the MPU 10. Further, the modulation / demodulation circuit 12 is the MPU 10 described above.
The information signal sent from the optical modulator is modulated, and the light beam irradiation optical system 17 is driven according to the modulated signal to record information. The MPU 10 is controlled by the CPU 9 and exchanges data with the CPU 9.

FIG. 5 is a perspective view showing details of the optical head portion of FIG.

As shown in FIG. 5, a beam emitted from a light source 20 such as a semiconductor laser is collimated by a collimator lens 21 and divided into three beams by a diffraction grating 23. These beams are imaged by the objective lens 26 on the tracking track 37, the information track 39, and the tracking track 38 on the optical card 19 as shown in FIG. 6, and the beam spots S1, S2, S3 are respectively formed.
To form.

Here, the optical card 19 is moved in the arrow direction (R direction) by a driving means (not shown), and is scanned by the beam spot in the extending direction of the tracking track. Beam spot S1, S2, S3
The reflected light of (1) again passes through the objective lens 26, is reflected by the beam splitter 24, and is projected onto the photodetectors 28, 29, 30 by the condenser lens system 27, respectively.

The condenser lens system 27 is an astigmatism system, and is an example in which it is arranged so that it can be performed by the astigmatism method well known in autofocusing. These photo detectors
As shown in FIG. 7, the arrangement is shown.

In FIG. 5, 22 is a prism for converting the cross-sectional distribution of the collimated light beam emitted from the semiconductor laser from an ellipse to a circle, and 25 is a mirror for guiding the light beam to the objective lens 26. The photodetector 29 has a light-receiving surface divided into four, as indicated by A, B, C, and D in FIG.

FIG. 9 is a block diagram for explaining an example of a conventional AF and AT control loop circuit.

In FIG. 9, photodetector 28 and photodetector 30 are tracking tracks 37 and 38 shown in FIG.
The light beams reflected from the photodetector 28 and the photodetector 30 are output from the current-voltage converter 6.
And 5 to be sent to the tracking control circuit 110. The tracking control circuit 110 takes the difference between the above two outputs and applies the tracking error signal to the tracking actuator 16 shown in FIG. 4, which is a driving means for the beam spot, to form a negative feedback loop.

Similarly, the photodetector 29 detects the light beam reflected from the information track, and converts the sum signal of A and D and the sum signal of B and C of the four-division sensor into current-voltage conversion. It is sent to the focusing control circuit 111 via the devices 3 and 4. Here, the difference between the two signals is taken and becomes a so-called focusing error signal. This error signal is applied to the focusing actuator 15 shown in FIG. 4, which is a means for driving the beam spot, and forms a negative feedback loop.

Here, the voltage-current converters 3 to 6 each have a structure in which only two feedback resistors Rr and Rw are switched by a switch, and the voltage-current converters 3 to 6 are responsive to a recording information signal (WD) output from the modulation / demodulation circuit 12. Change the gain. As a result, fixed gains for recording and reproducing are switched.

To reproduce the recorded information, the center beam S2 of the three beams shown in FIG. 6 is applied to the information pit, the reflected light is received by the four-division sensor 29, and the voltage change is performed via the current-voltage converter. It is based on the original. In addition, in the four-division sensor 29, the sum signal of (A + B + C + D) is used as the reproduction signal.

In the conventional optical information recording / reproducing apparatus described above, the recording medium to be used is limited. Therefore, the device does not need to deal with various recording media. Therefore, the AF / AT control gains and the reproduction gains are fixed values. Further, the semiconductor laser, which is a light source, is driven by binary driving, that is, the injection current for reproduction and the injection current for recording are fixed, and these are switched depending on the purpose.

Next, it is widely known that there are various kinds of information recording media usable for the optical information recording / reproducing apparatus. For example, the recording layer may be a metal film of tellurium, bismuth, etc., an organic film of polystyrene, nitrocellulose, etc., a dye film of cyanines, etc., or a tellurium low oxide film utilizing phase transition. These recording materials are so-called DRAW (direct read after write) media that can be "read immediately after writing" without the need for development processing after recording information, and high density recording is possible. Additional recording is also possible.

[0023]

Although these various recording media are useful as recording media in their respective optical or chemical characteristics, they are not always necessary in consideration of a combination with a conventional optical information recording / reproducing apparatus. Not everything is useful. Because, in terms of the optical characteristics of various recording media,
First, each has a wavelength characteristic with respect to light, and even if the same wavelength light is irradiated, the respective reflectances are different.

Further, in terms of chemical characteristics, the degree of deformation or discoloration due to heat is different. Therefore, it is the current situation that the recording medium is limited as described above and an apparatus that matches the characteristics of the medium is being developed, and there is a problem that the existing optical information recording / reproducing apparatus cannot support various recording media. is there.

Here, in the conventional optical information recording / reproducing apparatus,
A case where a recording medium having optical characteristics other than that designated by the device is inserted will be described. The reflectance of the recording medium is n times that of the designated recording medium. When such a recording medium is inserted, the amount of light received by each sensor becomes n times, so that each control signal level after the current-voltage converter also naturally becomes n times. However, since each control gain of the device is fixed, each control sensitivity becomes n times.

This will be described with reference to FIG. The waveform shown in FIG. 10 is a so-called S-shaped signal for AF control. A waveform A is an AFS S-shaped signal of a recording medium designated by the device, and a waveform B is an AFS-shaped signal of a recording medium other than the device designated with a reflectance of n times. The amplitude of the waveform B is n times that of the waveform A. The AF control controls the AF actuator based on this waveform. Since the control gain is fixed here, the amount of movement of the objective lens having the waveform B with respect to the same voltage value is 1 / n times the waveform A, which is n times the control sensitivity. This also applies to the AT control and reproduction system.

It is desirable that the control sensitivity is constant in order to always perform stable control as a device. However, when a recording medium having a different reflectance is inserted, the control sensitivity changes, and a stable AT, It becomes difficult to control and reproduce each AF, and at worst, AT and AF are not applied at all.

In addition, the inability to access a recording medium other than the designated one causes a problem that the versatility of the system is impaired.

(Object of the Invention) The present invention has been made in view of the above problems, and provides a versatile optical information recording / reproducing apparatus capable of stable recording and / or reproducing on various recording media. The purpose is that.

[0030]

[Means and Actions for Solving the Problems]

(Means and Action A) According to the present invention, the sensor detects the reflected light from the area where no information is recorded on the optical information recording / reproducing medium, and the power of the laser light to be emitted according to the output of the sensor is determined. By controlling the optical information recording / reproducing apparatus, stable recording / reproducing / controlling can be performed on various recording media having different reflectances.

(Means and Action B) Further, according to the present invention, the sensor detects the reflected light from the area where the information is not recorded on the optical information recording / reproducing medium, and the AT / By performing AF gain control and reproduction gain control, it is possible to realize an optical information recording / reproducing apparatus capable of performing stable recording / reproduction / control on various recording media having different reflectances.

[0032]

【Example】

(Example A) Examples of the present invention will be specifically described below. FIG. 1 is a schematic block diagram of a semiconductor laser power control unit of an optical card recording / reproducing apparatus which is an optical information recording / reproducing apparatus of the present invention. The optical card and the sensor are the same as in the conventional example, and will be described with reference to the schematic configuration diagrams of FIGS. 8 and 7, respectively.

In FIG. 1, 201 is an optical card recording / reproducing device, 202 is an optical card, 203 is an optical head, 204 is a semiconductor laser, 28 to 30 are sensors, 206 is an AT actuator, 207 is an AF actuator, and 208 is a current voltage. The conversion circuit, 209 is a microprocessor (MP
U) and 210 are laser drivers having a voltage-current conversion function. In the optical card recording / reproducing apparatus 201, the recording power and the reproducing power are initially set as reference powers according to the optical characteristics of the designated optical card 202. Here, the reference power of the reproduction power is the initial setting power Pi.

An optical card recording / reproducing apparatus 201 according to FIG.
The semiconductor laser power control method in 1) will be described.

First, the case where the designated optical card 202 is inserted into the optical card recording / reproducing apparatus 201 will be described. Immediately after inserting the optical card 202, the laser driver 210 causes the semiconductor laser 20 to emit the reproduction initial setting power Pi.
Inject current into 4. The reproduction light of the initial setting power Pi is
The optical head 203 illuminates the optical card 202.
The light irradiation position at this time is the home position 105 of an unrecorded area where information is not recorded, other than the recording area 102 of the optical card shown in FIG.

The light is reduced to a light amount according to the reflectance of the designated optical card 202, and is received by the sensors 28-30.
The output currents of the sensors 28 to 30 are converted into current-voltage conversion circuits 208.
Is converted into a voltage by means of which the AF control is carried out. AT control is not performed at the home position without the tracking track. In the optical card recording / reproducing device 201, the AT control uses the three-beam method and the AF control uses the astigmatism method. Further, the sensors 28 to 30 have the same configuration as the sensor of FIG. 7 shown in the conventional example as described above.

The output voltage level from the current-voltage conversion circuit 208 is judged by the MPU 209. In this case, it is determined that the voltage level is from the optical card specified by the device, and M
Since the [injection current amount change command] is not issued from the PU 209 to the laser driver 210, the semiconductor laser 20
The light emission power of No. 4 remains the initial setting power Pi. The voltage level from the predetermined optical card is Si.

Next, a case where an optical card 202 'having a reflectance different from that of the designated optical card is inserted into the optical card recording / reproducing apparatus 201 will be described.

First, immediately after the optical card 202 'is inserted, the laser driver 210 injects a current into the semiconductor laser 204 so that the reproduction power becomes the initial setting power Pi. The AF is pulled in the same process as when the designated optical card 202 is inserted. At this time, the output voltage level from the current-voltage conversion circuit 208 becomes S.

The MPU 209 compares the voltage level S with the voltage level Si at the initial setting power Pi, and the semiconductor laser 204 is set so that the setting power P in the semiconductor laser 204 becomes P = (Si / S) × Pi. The injection current amount I is calculated. The injection current amount I can be calculated from the relationship between I (injection current) and P (power) of the semiconductor laser shown in FIG. That is, assuming that the threshold current of the semiconductor laser is It and the injection current at the initial setting power is Ii, I = Ii + (P-Pi) / A where A = Pi / (Ii-It). Based on this, the MPU 209 issues an [injection current change command] to the laser driver 210,
The driver 210 drives the semiconductor laser 204 with the injection current I. FIG. 3 shows the relationship between the output voltage S of the current-voltage conversion circuit 208 and the set power P at this time.

According to the laser power control method of the present invention described above, the amount of light received by each control sensor is always constant even if optical cards having different reflectances are inserted, so that the output from the current-voltage conversion circuit is constant. The voltage level is naturally constant. That is, in the optical card recording / reproducing apparatus with fixed control system gains, the control sensitivities of the AF control, AT control, and reproducing system can always be kept constant even if optical cards having different reflectances are inserted. As a result, the versatility of the system can be enhanced, and an optical card recording / reproducing apparatus that enables more stable control can be achieved.

(Embodiment B) Another embodiment of the present invention will be specifically described below. FIG. 11 shows an AT / AF of an optical card recording / reproducing apparatus which is an optical information recording / reproducing apparatus of the present invention.
It is a schematic block diagram of a gain control unit and a reproduction gain control unit.

The optical card and the sensor are the same as in the conventional example, and will be described with reference to the schematic configuration diagrams of FIGS. 8 and 7, respectively.

In FIG. 11, 301 is a CPU, 302
Is an optical card recording / reproducing device, 303 is an optical card, 304 is an MPU, 305 is an AT / AF control circuit, 306 is a current-voltage converter, 307 is a modulation / demodulation circuit, 308 is an optical head, 3
09 is a semiconductor laser, 328 to 330 are sensors, 311
Is an AT actuator and 312 is an AF actuator.

In the optical card recording / reproducing device 302, the reproducing power is adjusted in accordance with the optical characteristics of the designated optical card 303.
Reference conversion constants Gi and AT / of the current-voltage converter 306
Each constant of the AF control circuit 305 is initialized.

Here, the reproducing power and the recording power are determined by the optical characteristics and chemical characteristics of the optical card 303 designated by the apparatus, and are fixed values respectively. Further, each control gain in the AT / AF control circuit is also a fixed value (constant).

Optical card recording / reproducing apparatus 30 according to FIG.
The AT / AF gain control and reproduction gain control method in 2 will be described.

First, the case where the designated optical card 303 is inserted into the optical card recording / reproducing apparatus 302 will be described. Immediately after inserting the optical card 303, the semiconductor laser 309 is driven for reproduction power. The light irradiation position at this time is the home position 105 of an unrecorded area where information is not recorded, other than the recording area 102 shown in FIG. Light is a designated light card 3
Sensor 328-3 is dimmed to a light amount according to the reflectance of 03.
Received at 30.

The light is photoelectrically converted by the sensors 328 to 330 and converted into a voltage by the current-voltage converter 306. The conversion constant at this time is defined as a reference conversion constant Gi. The AF control signal of the control signals is input to the AT / AF control circuit 305, and the output signal controls the AF actuator 312. The reproduction signal is passed through the modulation / demodulation circuit 307 and the MPU3.
It is input to 04.

The MPU 304 determines that the reproduction signal is at the voltage level of the optical card designated by the device, and the [conversion constant change command] from the MPU 304 to the current-voltage converter 306 is not performed.

Although AT control is not performed at the home position where there is no tracking track, the objective lens is fixed at a neutral position of the AT actuator drive range in consideration of safety. Further, the reproduction signal voltage level from the designated optical card is Va, and the sensor output at that time is Si.

Next, a case will be described in which an optical card 303 'having a reflectance different from that of the designated optical card is inserted into the optical card recording / reproducing device 302. First, the optical card 30
Immediately after the 3'is inserted, the semiconductor laser 309 is driven with the reproducing power. AF is pulled in the same process as when the designated optical card 303 is inserted. The reproduced signal voltage level Vb at this time and the sensor output at that time are S.

The MPU 304 compares the voltage level Vb with the reproduction signal voltage level Va of the designated card 303. At this time, since Va: Vb = (Si × Gi) :( S × Gi) = Si: S, Vb is determined to be (S / Si) times Va. Therefore, the setting conversion constant G is calculated so that the determined setting conversion constant G is G = (Si / S) × Gi. MPU304
Performs [conversion constant change command] which is the set conversion constant G to the current-voltage converter 306. MP in current-voltage converter 306
Based on the information of U304, switch the constant changeover switch.

As a result, the current-voltage conversion constant which is the set conversion constant G is switched. That is, the current-voltage converter 30
6, the voltage level of each signal output to the AT / AF control circuit 305 and the modulation / demodulation circuit 307 is the optical card 3 designated by the device.
It becomes the same level as 03, and a constant voltage level can always be obtained.

This will be described with reference to FIG. In FIG. 12, both waveforms A and B are reproduction signals, which are obtained by (A + D + B + C) of the 4-division sensor 29 shown in FIG. A waveform A is a reproduction signal when the optical card 303 is designated by the device, and a waveform B is an optical card 30 having a reflectance different from that of the optical card 303.
It is a reproduction signal at the time of 3 '. Here, the purpose is to make the voltage level Vb of the waveform B equal to the voltage level Va of the waveform A. That is, since V = Si × Gi = S × G = constant, the current-voltage converter 306 may control the conversion constant so that G = (Si / S) × Gi. The relationship between the sensor output S and the setting constant G at this time is shown in FIG. Although not shown, the AT and AF signals can be made to have a constant voltage level by the same conversion constant control.

By the way, the current-voltage converter 306 requires at least one conversion constant changeover switch, that is, as many switches as the number of recording media that may be inserted. Since the reflectance of a recording medium is almost determined by the recording material and the manufacturing method, the number of changeover switches is naturally determined if the reflectance of the existing optical card is known.

According to the AT / AF gain control and reproduction gain control methods of the present invention described above, it is possible to set the current-voltage conversion constant of the sensor output according to the output of the sensor. It is possible to achieve an optical card recording / reproducing apparatus capable of performing stable recording / reproduction / control on various recording media having different reflectances while keeping the AT / AF control gain of the / AF control circuit constant.

As another embodiment, instead of each gain control using a changeover switch, an automatic gain controller (A
Even if GC) is used, the same effect as in the above embodiment can be achieved. Since the gain can be continuously controlled in the AGC, not only can various recording media be dealt with, but also variations in reflectance that occur during manufacturing can be dealt with, and the reliability of the device can be further improved.

Further, in the above-mentioned Examples A and B, the light irradiation position during the laser power control and the AT / AF gain control was set to the home position 105, but information is recorded at a portion having a recording layer. If it is an area that is not covered, there is no problem other than the home position.

The area in which information is recorded cannot be distinguished because it cannot be distinguished whether the sensor output change during control is due to recorded information or due to a difference in medium type.

Further, it is desirable to perform AT control at the portion where the tracking track exists.

[0062]

【The invention's effect】

(Effect A) As described above, in the optical information recording / reproducing apparatus for recording and / or reproducing information, the sensor detects the reflected light from the area where the information is not recorded on the optical recording medium, and By controlling the power of the laser beam according to the sensor output, it is possible to always maintain a constant control sensitivity for information recording media having different reflectances, and to perform stable AT control, AF control, and reproduction. be able to.

(Effect B) Further, as described above, in the optical information recording / reproducing apparatus for recording and / or reproducing information, the reflected light from the area where the information is not recorded on the optical recording medium is sensed. By performing the current-voltage conversion constant control of the sensor output according to the sensor output, stable AT control, AF control, and reproduction can be always performed even for information recording media having different reflectances.

[Brief description of drawings]

FIG. 1 is a schematic block diagram showing an embodiment of the present invention.

FIG. 2 is an IL characteristic diagram of a semiconductor laser.

FIG. 3 is a relationship diagram between an output voltage S and a set power P in the present invention.

FIG. 4 is a schematic block diagram of a conventional optical information recording / reproducing apparatus.

FIG. 5 is a perspective view of an optical head.

FIG. 6 is a layout diagram of a light beam.

FIG. 7 is a configuration diagram of a sensor.

FIG. 8 is a schematic plan view of an optical card.

FIG. 9 is an electric circuit diagram of a conventional example.

FIG. 10 is a control signal waveform diagram of a conventional example.

FIG. 11 is a schematic block diagram showing another embodiment of the present invention.

FIG. 12 is a reproduction signal waveform diagram immediately after the recording medium of the present invention is inserted.

FIG. 13 is a relationship diagram between a sensor output and a set conversion constant.

[Explanation of symbols]

 201 optical card recording / reproducing device 202 optical card 203 optical head 204 semiconductor laser 206 AT actuator 207 AF actuator 208 current / voltage conversion circuit 209 MPU 210 laser driver 28-30 sensor 105 home position 301 CPU 302 optical card recording / reproducing device 303 optical card 304 MPU 305 AT / AF control circuit 306 Current-voltage converter 307 Modulation / demodulation circuit 308 Optical head 309 Semiconductor laser 311 AT actuator 312 AF actuator 328-330 Sensor

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location G11B 19/02 S 7525-5D

Claims (14)

[Claims] 1. A card-shaped optical information recording medium is irradiated with a laser beam to record information, and / or a laser beam is irradiated, and reflected light from the optical information recording medium is detected by a sensor. In an optical information recording / reproducing apparatus for reproducing information, the reflected light from an area where information is not recorded on the card-shaped optical recording medium is detected by the sensor, and the laser light is output according to the sensor output. An optical information recording / reproducing apparatus having means for controlling the power of the irradiation means. 2. The setting power determined by the power control is P, the initial setting power is Pi, and the initial setting power P is
When the sensor output in the case of i is Si and the sensor output of the reflected light is S, the power control of the laser light irradiation means is performed so as to satisfy P = (Si / S) × Pi. Item 1. The optical information recording / reproducing apparatus according to item 1. 3. The optical information recording / reproducing apparatus according to claim 1, wherein the power control controls an injection current of a semiconductor laser serving as the laser light irradiation means. 4. The setting power P determined by the power control, the initial setting power Pi, and the initial setting power P
The injection current in the case of i is Ii, the threshold current of the semiconductor laser is It, and the injection current in the case of the set power P is I
Then, the injection current I of the semiconductor laser is controlled so that I = Ii + (P-Pi) / A [where A = Pi / (Ii-It)] is satisfied. Optical information recording / reproducing device. 5. The optical information recording / reproducing apparatus according to claim 1, wherein the area is an unrecorded area other than the information recording area. 6. The power control is performed immediately after setting the optical information recording medium at a predetermined position of the optical information recording / reproducing apparatus.
The optical information recording / reproducing apparatus described in 1. 7. A card-shaped optical information recording medium is irradiated with a laser beam to record information, and / or a laser beam is irradiated to detect reflected light from the optical information recording medium with a sensor. In an optical information recording / reproducing apparatus that reproduces information by using the optical disc and performs auto-focusing (hereinafter referred to as AF) / auto-tracking (hereinafter referred to as AT). An optical information recording / reproducing apparatus having means for detecting the reflected light with the sensor and controlling AT / AF gain and reproducing gain according to the sensor output. 8. When the setting constant determined by the AT / AF gain control and the reproduction gain control is G, the initial setting reference constant is Gi, the reference sensor output is Si, and the sensor output of the reflected light is S, G = 8. The optical information recording / reproducing apparatus according to claim 7, wherein the AT / AF gain control and the reproduction gain control are performed so as to satisfy (Si / S) × Gi. 9. The optical information recording / reproducing apparatus according to claim 7, wherein the AT / AF gain control and the reproduction gain control are performed by a current-voltage converter connected to the sensor output. 10. The optical information recording / reproducing according to claim 7, wherein the AT / AF gain control and the reproduction gain control are performed by switching at least one changeover switch included in the current-voltage converter. apparatus. 11. The optical information recording / reproducing apparatus according to claim 7, wherein the AT / AF gain control and the reproduction gain control are performed by a command from a microprocessor (MPU) based on a reproduction signal. 12. The automatic gain controller (hereinafter referred to as AG
The optical information recording / reproducing apparatus according to claim 7, wherein the optical information recording / reproducing apparatus is performed in C). 13. The optical information recording / reproducing apparatus according to claim 7, wherein the area is an unrecorded area other than the information recording area. 14. The gain control is performed immediately after setting the optical information recording medium at a predetermined position of the optical information recording / reproducing apparatus.
The optical information recording / reproducing apparatus described in 1.