JPH1139686A - Optical information recording device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform simultaneous verification with recording without generating a pseudo signal at the time of binarizing a verifying signal by reducing a spike noise in the verifying signal. SOLUTION: By supplying a gain changeover signal delayed by a prescribed time by means of a delay circuit 67 to a gain changeover circuit 65 removing a power modulation component due to the modulation of a recording spot by changing a gain for amplifying the output signal of a photodetector 31, a spike noise due to the delay of output of a LD driver 61 is reduced. When recording is performed by dividing one track into plural sectors, non-recording power is turned off except the objective sector to be recorded.

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 apparatus for optically recording information on an information recording medium such as an optical card.

[0002]

2. Description of the Related Art Conventionally, various types of recording media for optically recording information or reproducing recorded information, such as a disk, a card, and a tape, are known. Among these information recording media, there are those that can be recorded and reproduced and those that can only be reproduced. In recording information on a recordable recording medium, information is recorded as an optically detectable information pit array by scanning a light beam in the form of a minute spot modulated according to the recording information on an information track. .

When information is reproduced from a recording medium, an information pit array of an information track is scanned with a light spot having a constant power enough to prevent recording on the recording medium, and reflected light or transmitted light from the recording medium is read. Is detected, and the recorded information is reproduced based on the obtained detection signal. An optical head used for recording and reproducing information on and from such a recording medium is configured to be movable relative to the recording medium in the information track direction and in the direction across the track. The spot accesses a desired information track, and the information track is scanned to record or reproduce information.

An optical head is provided with a focusing lens for narrowing a light beam, and an objective lens is used as this lens. As such an objective lens,
The optical head body is held so as to be independently movable in the optical axis direction (focus direction) and the direction (tracking direction) orthogonal to the information track of the recording medium in each direction. Such an objective lens is generally held through an elastic member, and the focus and the movement of the objective lens in the tracking direction are generally driven by an actuator utilizing magnetic interaction.

FIG. 11 is a schematic plan view of an optical card.
On the information recording surface of the optical card 1, a large number of information tracks 2
Are arranged in parallel to the LF direction. On the information recording surface of the optical card 1, a home position 3 serving as a reference position for accessing the information track 2 is provided. Information track 2 is 2
-1, 2-2, 2-3...

As shown in FIG. 12, tracking tracks 4-1 and -4 are located adjacent to the information tracks 2 respectively.
4-2, 4-3... These tracking tracks are used as guides for auto tracking (hereinafter abbreviated as AT) for controlling the light spot so as not to deviate from the information track during light spot scanning during information recording and reproduction.

Such an AT control detects an offset (AT error) of a light spot from an information track and uses the detected information to control a tracking actuator for driving an objective lens in a tracking direction. It is controlled by returning to. That is, the servo control circuit moves the objective lens in the tracking direction (D direction) according to the AT error, thereby controlling the light spot so as not to deviate from the target information track.

In addition, when scanning an information track with an optical spot at the time of information recording and reproduction, an auto lens with respect to an objective lens is formed in order to form (focus) a light beam on the optical card surface into a spot of an appropriate size. Focus (hereinafter, AF
Is abbreviated). Such AF control detects a deviation (AF error) of a light spot from a focused state,
The detection signal is controlled by feeding it back to an AF control circuit for controlling a focus actuator for moving the objective lens in the optical axis direction. That is, by moving the objective lens in the focus direction according to the AF error, the control is performed so that the light spot is focused on the optical card surface (recording layer).

Here, in FIG. 12, S1, S2, S
3, S4 and S5 show light spots irradiated on the information tracks of the optical card. Among them, the light spot S partially covering the tracking tracks 4-2 and 4-3
AT control is performed using steps S1 and S5. Also, AF control using the light spot S3, creation of information pits during recording,
And read out information pits during reproduction. Further, the information pits immediately after recording are verified using the light spots S2 and S4. In the figure, 5-1 and 5-2 are light spots S.
The information pit 5-1 is a pit recorded by scanning the light spot in the L direction, and the information pit 5-2 is a pit recorded by scanning the light spot in the F direction.

FIG. 13 is a block diagram showing an optical information recording / reproducing apparatus using an optical card as an information recording medium. In FIG. 13, reference numeral 21 denotes a semiconductor laser as a light source, which emits a laser beam having a wavelength of 830 nm polarized in a direction perpendicular to a track, for example. 23 is a collimator lens, 50 is a diffraction grating having a two-dimensional grating for splitting a light beam, and 26 is a polarization beam splitter. 27 is a quarter-wave plate, 28 is an objective lens,
29 is a spherical lens, 30 is a cylindrical lens, 31
Is a photodetector. As shown in FIG. 14, the photodetector 31 includes light receiving elements 31a, 31b, 31d, and 31e, and one four-divided light receiving element 31c. Each of the above optical elements is integrated as an optical head,
It is configured so that a desired information track of the optical card 1 can be accessed. 61 is a laser driver (hereinafter, LD)
Reference numeral 62) denotes an MPU.

Here, when information is recorded on the optical card 1 by the optical head, a drive current at a recording level is supplied to the semiconductor laser 21 by the LD driver 61 in accordance with a recording command from the MPU 62. When reproducing information, M
A current at a reproduction level is supplied to the semiconductor laser 21 by the LD driver 61 in accordance with a reproduction command from the PU 62. The semiconductor laser 21 is driven in this manner, and the light beam emitted from the semiconductor laser 21 enters the collimator lens 23 as a divergent light beam. Then, after being collimated by the collimator lens 23, the light is incident on the two-dimensional diffraction grating 50, and is split by the diffraction grating 50 into five effective light beams (0th-order diffraction light and ± 1st-order diffraction light in two directions).

The five split light beams enter the polarization beam splitter 26 as a P-polarized light beam, pass through the light beam, enter the quarter-wave plate 27, and pass through the quarter-wave plate 27. Is converted into circularly polarized light. The five light beams converted into the circularly polarized light are narrowed down to a minute light spot by the objective lens 28, and are irradiated onto the optical card 1. The irradiated light is light spots S1, S2 (+ 1st order diffracted light), S3 (0th order diffracted light), S4, S5 (-1st order diffracted light) as shown in FIG. As described above, the light spot S3 is used for recording, reproduction and AF control, S1 and S5 are used for AT control, and S2 and S4 are used for verifying information pits immediately after recording. As shown in FIG. 12, light spots S1 and S5 are located on adjacent tracking tracks, and light spots S2, S3 and S4 are located on information tracks between the tracking tracks.

In this manner, the light spot is irradiated onto the optical card 1, and a part of the light spot is reflected on the optical card surface and enters the objective lens 28. This reflected light passes through the objective lens 28 again to become a parallel light flux, and further passes through the quarter-wave plate 27 to be converted into a light beam whose polarization direction has been rotated by 90 ° from that at the time of incidence. Then, the polarization beam splitter 26
, As an S-polarized beam, is reflected toward the detection optical system by its characteristics, and is separated from the incident light beam from the semiconductor laser 21.

The detection optical system comprises a spherical lens 29, a cylindrical lens 30, and a photodetector 31, and performs AF control by an astigmatism method by a combination of the spherical lens 29 and the cylindrical lens 30. The five light beams reflected from the optical card 1 are detected by a light detector 31 including a plurality of light receiving elements. The respective light receiving signals of the plurality of light receiving elements of the photodetector 31 are sent to a recording / reproducing gain switching circuit 65. The recording / reproduction gain switching circuit 65 is a circuit for correcting the fluctuation of the signal level of each light receiving element caused by the modulation of the recording light spot, that is, the change of the recording power and the reproduction power, and keeping it at a substantially constant signal level. . That is, the gain for amplifying the signal is switched in accordance with the recording / reproduction gain switching signal output from the MPU 62, and the signal of each light receiving element is maintained at a constant signal level.

The output signal of the recording / reproduction gain switching circuit 65 is sent to an addition / subtraction circuit 63, a subtraction circuit 64, and a selection switch 66. The addition and subtraction circuit 63 includes an AF control signal (focus error signal),
And an information reproduction signal RF, and an AT control signal (tracking error signal) is generated in the subtraction circuit 64.
Sent to PU62. The selection switch 66 selects a verifying signal according to a moving direction signal (a signal indicating the scanning direction of the light spot) from the MPU 62 as described later. The MPU 62 drives a focus actuator and a tracking actuator (not shown) based on the AF control signal and the AT control signal, and
Is displaced in the focus direction and the tracking direction to perform focus control and tracking control. At the time of information reproduction, the MPU 62 performs predetermined signal processing on the information reproduction signal RF to generate reproduction data. Further, at the time of recording information, the selection switch 66
The verifying signal selected in step (1) is binarized, and this is compared with the recording signal to perform verifying at the same time as recording, that is, direct verifying.

FIG. 15 shows a schematic view of the diffraction grating 50. The diffraction grating 50 has two diffraction regions for AT, AF, and verification. By arranging the diffraction grating in the irradiation optical system, it is possible to form an image of five minute light spots on the optical card 1. The diffraction grating 50 has a recording spot S3.
Is set to a recording power, and diffraction conditions are set so that the other AT spots S1 and S5 and the verifying spots S2 and S4 have a non-recording power that cannot be recorded.

FIG. 16 is a specific circuit configuration diagram of the LD driver 61. In FIG. 16, reference numeral 201 denotes a current source that outputs a driving current corresponding to recording light power, and 202 denotes a current source that outputs a driving current corresponding to reproduction light power. Reference numeral 203 denotes a switch for superimposing a recording light current on a reproduction light current in accordance with a recording signal. Reference numeral 21 denotes a cathode ground semiconductor laser. At the time of reproduction, the recording signal is off, and a current corresponding to the reproduction light power is supplied to the semiconductor laser 21 by the current source 20.
Supplied from 2.

On the other hand, at the time of information recording, the recording signal is on, the switch 203 is turned on or off in accordance with the recording signal WD, and the semiconductor laser 21 has the switch 20 on the reproduction light current.
3, the recording light current from the current source 201 is supplied in a superimposed state. Here, as is apparent from FIG. 16, since the semiconductor laser 21 is driven using only the positive power supply _Vcc , the switch 203 is of a PNP transistor type. In order to stabilize the optical power for reproduction and recording, a semiconductor laser 2 is generally used.
APC (automatic power control) for monitoring a part of the light output of No. 1 and applying feedback.

FIG. 14 shows the photodetector 31, the recording / reproduction gain switching circuit 65, the addition / subtraction circuit 63,
The subtraction circuit 64 and the selection switch 66 are shown in detail.
First, reference numeral 31 denotes a photodetector, and light receiving elements 31a, 31b, 31
d, 31e and a four-divided light receiving element 31c.
The light spot on the light receiving surface of each light receiving element indicates the reflected light of the light spot applied to the information track in FIG. A
The reflected light from the light spots S1 and S5 for T control is
1a, 31e, the reflected light from the AF control, recording, and reproducing light spot S3 is a four-divided light receiving element 31c, and the reflected light from the verifying light spots S2, S4 is the light receiving elements 31b, 3
The light is received at 1d.

The output signals of the light receiving elements 31a to 31e of the photodetector 31 are input to the corresponding gain switching circuits 101 to 108 of the recording / reproduction gain switching circuit 65. That is,
The output signal of the light receiving element 31a is input to the gain switching circuit 101, the output signal of the light receiving element 31b is input to the gain switching circuit 102, and the output signals of the four light receiving element pieces of the four-divided light receiving element 31c are input to the gain switching circuits 103 to 106, respectively. Is done.
Also, the output signal of the light receiving element 31d is
7. The output signal of the light receiving element 31e is supplied to the gain switching circuit 108.
Is input to These gain switching circuits 101 to 108
Represents the gain for amplifying the signal as described above.
1, the output signals of the light receiving elements 31a to 31e are held at constant signal levels by the gain switching operation of each gain switching circuit.

FIG. 17 shows the configuration of the gain switching circuits 101 to 108. A feedback resistor Rr for determining a gain at the time of reproduction is connected between the minus input and the output of the operational amplifier 204, and a series circuit of an analog switch 205 switched by a recording / reproduction gain switching signal and a feedback resistor Rw is connected in parallel with the feedback resistor Rr. Here, the recording / reproduction gain switching signal is a recording signal WD which is turned on / off corresponding to a pit to be recorded.
Is used. When the recording / reproduction gain switching signal is turned on, the analog switch 205 is turned on and the feedback resistor R
The parallel resistance of r and the feedback resistance Rw is set to the gain at the time of recording. The feedback resistor Rr is determined to have an appropriate gain so that the output of the operational amplifier is not saturated with the light receiving element signal during reproduction.

The output signals of the gain switching circuits 101 and 108 are output to a subtraction circuit 64, and the subtraction circuit 64 detects the difference to generate an AT control signal. The gain switching circuits 103 to 106 correspond to the four light receiving element pieces of the four-divided light receiving element 31c.
Output signals of the gain switching circuits 103 and 105 corresponding to the light receiving element pieces in the diagonal directions, and the gain switching circuit 104
And 106 output signals are added to adders 117 and 118, respectively.
Is added. The difference between the output signals of the addition circuits 117 and 118 is detected by the subtraction circuit 120 and output as an AF control signal. The output signals of the adders 117 and 118 are added by the adder 121 to generate a sum signal of the four-divided light receiving element 31c. The sum signal of the four divided light receiving elements is output as an information reproduction signal RF.

The output signals of the gain switching circuits 102 and 107 are output to a selection switch 66, and one of the DV (direct verify) signals is selectively output according to the moving direction signal from the MPU 62. Specifically,
If the scanning direction of the light spot is the F direction as shown in FIG. 12, the selection switch 66 is connected to the F side,
The signal on the e side is output to the MPU 62 as a verifying signal. On the other hand, if the scanning direction of the light spot is the L direction, the selection switch 66 is connected to the L side, and a signal on the light receiving element 31b side is output to the MPU 62 as a verifying signal. That is, since the verifying light spots S2 and S4 are radiated to both sides of the recording light spot S3, when the scanning direction of the light spot changes between the forward path and the return path of the optical card, the recording light spot is correspondingly changed. After that, the verifying signal reproduced by the light spot to be scanned is selected.
The MPU 62 performs verification at the same time as recording using the selected verification signal.

[0024]

In the above-mentioned prior art, the recording / reproduction gain switching circuit 65 modulates the recording light spot, that is, the signal level of each light-receiving element caused by a change in recording light power and reproduction light power. Is compensated for. However, when the gain is switched in synchronization with the recording signal, spike noise is generated along with the gain switching, and the waveform of the verifying signal is disturbed. 18A shows a recording signal, FIG. 18B shows an optical power modulation waveform, and FIG. 18C shows a recording / reproduction gain switching signal. FIG. 18D shows an output signal waveform of the gain switching circuit 102 (or 107) for verification when there is no pit on the information track. When there is no information pit, the power modulation component is originally removed by the gain switching operation, so that the signal level becomes constant. However, spike noise is generated in accordance with the gain switching timing.

This is because, when the gain is switched in synchronization with the rise of the recording signal, the optical power is changed to the LD as shown in FIG.
This occurs because the recording light power has not been reached due to the delay of the output of the driver 61. That is, while the gain of the gain switching circuit has been switched to a low gain corresponding to the recording power, the optical modulation waveform has not risen to the recording power, so the output of the gain switching circuit is as shown in FIG. Low level, which appears as spike noise.

Similarly, when the gain is switched in synchronization with the fall of the recording signal, the optical power is not completely reduced to the reproduction light power due to the delay of the output of the LD driver at the moment when the gain is switched to the reproduction gain. FIG. 18 (d)
As a result, spike noise is generated in the output of the gain switching circuit. In addition, the spike noise is generated due to the delay of the output of the gain switching circuit, or is generated by combining the delay of the output of the LD driver and the output of the gain switching circuit.

FIG. 18E shows a verifying signal when only a modulation component due to an information pit is received.
Originally, if spike noise does not occur at the time of gain switching, the verifying signal has a waveform as shown in FIG. 18 (e), and when this is binarized, a binary signal corresponding to the recording signal is obtained as shown in FIG. 18 (h). Signal can be obtained. Actually, however, the verifying signal is the signal of FIG.
Since the noise of (d) is superimposed, the waveform is as shown in FIG. Therefore, when this is binarized, FIG.
As shown in (g), a thin pulse-like pseudo signal due to spike noise is generated in the binary signal.

Even if binarization is performed using a binarization circuit having hysteresis as shown in FIG. 18 (f), there is no effect on large spike noise, and a pseudo signal is generated. Since the pulse width of the pseudo signal increases in accordance with the magnitude of the spike noise, when the pulse width of the pseudo signal increases, the information signal width of the information pit of the binary signal also changes. Therefore, there is a problem that the waveform becomes different from the recording signal, and even when the information can be recorded correctly, a verification error occurs and an erroneous verification is performed. In order to solve this problem, it is conceivable to use a high-speed LD driver with a small output delay, that is, an NPN-type switch as the switch. There was a problem that it was difficult to control.

Further, the present inventors have proposed an optical information recording apparatus for reducing a delay in response of an amplifier of a gain switching circuit or a spike noise generated by turning on / off an analog switch of an LD driver. Has been filed as Japanese Patent Application No. 9-162584. Hereinafter, the device of the prior application will be described. First, the overall configuration of the apparatus is the same as that shown in FIG. 13 except for the number of light spots applied to the optical card 1 and the configuration of the photodetector 31, LD driver 61, recording / reproduction gain switching circuit 65, and the like. I have.

FIG. 19 shows a light spot applied to the optical card. In FIG. 19, the laser beam of the semiconductor laser 21 is divided into seven light beams by the diffraction grating 50,
The divided light beams are irradiated as light spots S1 to S7. The difference from FIG. 12 is that the light spots S6 and S7 are increased, and the other points are the same as FIG. The light spots S1 and S5 are for AT control, S3 is recording, AF control,
Reproduction, S2 and S4 are used for verification, and S6 and S7 are used for reproduction.

FIG. 20 is a schematic diagram of the diffraction grating 50. In the drawing, reference numeral 50a denotes an AT diffraction grating forming unit for generating an AT control light beam that becomes the spots S1 and S5; 50b, a DV diffraction grating forming unit that generates a direct verification light beam that becomes the spots S2 and S4; Spot S6
, RFR for generating an information reproduction light flux to be S7
An L diffraction grating forming unit 301 is an incident light beam. Here, the diffraction angle θn of the diffracted light is determined by θn = n · λ / d (where n is the order) from the grating pitch d and the wavelength λ of the incident light beam. The diffraction direction is determined by the inclination δ of the grating with respect to the incident light beam, and the direction is substantially perpendicular to the grating. The diffracted light beam and the zero-order light beam that are diffracted are irradiated as light spots S1 to S7 on an optical card as shown in FIG. 19 via an objective lens or the like.

Further, the light power ratio of each light spot is such that the recording spot S3 (0-order diffracted light) is emitted when the recording light is emitted.
Is a recording light power for generating a recording pit, and a light spot S3.
The light power of the other spots is determined so that the recording pit is not generated. The light power ratio of each spot can be determined by setting the diffraction efficiency of each diffraction grating. That is, the light power of the light spot S3 is the sum of the zero-order light of each diffraction grating, and the light power of the other spots is set by the diffraction efficiency of the diffraction grating that generates the spot.

FIG. 21 shows the configuration of the signal processing circuit. The photodetector 31 includes light receiving elements 31f and 31g in addition to the light receiving elements 31a to 31e. Light receiving element 31f
Represents the reflected light of the light spot S6, and the light receiving element 31g detects the reflected light of the light spot S7. The recording / reproduction gain switching circuit 65 has gain switching circuits 109 and 110 in addition to the gain switching circuits 101 to 108. The gain switching circuit 109 amplifies the output signal of the light receiving element 31f, and the gain switching circuit 110 amplifies the output signal of the light receiving element 31g.
Output as R, RFL. However, the light receiving elements 31f, 3
Since 1g is used only during reproduction, the gain switching circuit 10
Reference numerals 9 and 110 perform only amplification without performing gain switching.
Other configurations are the same as those in FIG.

FIG. 22 shows the structure of the LD driver 61. In FIG. 22, reference numeral 21 denotes a semiconductor laser having a cathode ground. Reference numeral 801 denotes a current source that supplies a drive current corresponding to the recording power Pw to the semiconductor laser 21; 804, a current source that supplies a drive current corresponding to a power Pv that is not recorded during non-recording to the semiconductor laser 21; It is a current source that supplies a drive current corresponding to the power for reproduction Pr to the semiconductor laser 21. A switch 803 is driven according to the recording signal WD, and a switch 805 is turned on and off according to the recording / reproduction gain switching signal SG2. The recording / reproduction gain switching signal SG2 is a signal that turns on in the recording area and turns off in other cases. The recording signal WD and the recording / reproduction gain switching SG2 are supplied from the MPU 62 to the LD driver 61.

The MPU 62 sets the recording signal WD and the recording / reproduction gain switching signal SG2 to off during the information reproducing operation, and the switches 803 and 805 are off. Therefore, since only the current Ir of the current source 802 is supplied to the semiconductor laser 21, the semiconductor laser 21 emits reproduced light having a power Pr corresponding to the current Ir. The power Pr is a power at which the reflectivity does not become lower than a predetermined level even if the track of the optical card is scanned many times, that is, the reproduction light does not cause a problem.

Next, during the recording operation, the recording signal WD changes between on (high level) and off (low level), and when the recording signal WD is on, information pits are recorded on the optical card. The case where the recording signal WD is off is called a non-recording mode, and the case where it is on is called a recording mode. The MPU 62 turns on the recording / reproduction gain switching signal SG2 and turns on the switch 805 in the non-recording mode. Thereby, the current Ir of the current source 804 is added to the current Ir of the current source 802 in the semiconductor laser 21.
A current in which v is superimposed is supplied, and non-recording light with a power Pv corresponding to this current is emitted. This power Pv is a power at which the reflectance does not become lower than a predetermined level even when the track on the optical card is scanned about once. The non-recording power Pv is the power Pr at which no pit is formed on the optical card.
Higher power.

On the other hand, in the recording mode, the MPU 62
Turns on the recording / reproduction gain switching signal SG2, turns on the recording signal WD, and supplies the semiconductor laser 21 with a current obtained by superimposing the current Iw of the current source 801 on the current Ir of the current source 802 and the current Iv of the current source 804. Then, the recording light with the power Pw corresponding to the current is emitted. The power Pw is a level at which the reflectance is sufficiently reduced when the light is irradiated onto the optical card, that is, the power at which pits are formed on the optical card.
Power higher than v. In this case, the positive power supply V
_Since the semiconductor laser 21 is driven using only _cc , the switches 803 and 805 use PNP transistor type switches. Although not shown, in order to further stabilize the optical power for reproduction and recording, APC (auto power control) for monitoring a part of the optical output of the semiconductor laser 21 and applying feedback is performed.

FIG. 23 shows the gain switching circuits 101 to 108.
Is shown. In the following description, the output voltage / input voltage (that is, feedback resistance) is expressed as a gain. In FIG. 23, first, a feedback resistor Rr is connected between the (-) input and the output of the operational amplifier 701. The feedback resistor Rw connected in series with the analog switch 704 driven by the gain switching signal SG1 and the feedback resistor Rv connected in series with the analog switch 706 driven by the recording / reproduction gain switching signal SG2 are feedback resistors. Rr is connected in parallel. Here, the recording / reproduction gain switching signal SG
Reference numeral 1 denotes a signal which is turned on / off in accordance with a recording signal, and a recording / reproduction gain switching signal SG2 is a signal which is turned on when a recording area is set. These signals are supplied from the MPU 62, respectively.

Here, the recording / reproduction gain switching signal SG
When both SG1 and SG2 are turned off, the analog switch 704 is turned off.
And 706 are turned off, so that the gain is set only by the feedback resistor Rr. The gain at this time is a gain Gr corresponding to the power at the time of reproduction, and the feedback resistance Rr is set to an appropriate value so that the output of the operational amplifier 701 is not saturated with the light receiving element signal in the reproduction mode. Next, when the recording / reproduction gain switching signal SG2 is turned on and the recording / reproduction gain switching signal SG1 is turned off, the analog switch 706 is turned on and the analog switch 704 is turned off, so that the gain is determined by the parallel resistance of the feedback resistor Rr and the feedback resistor Rv. Is set. The gain at this time is a gain Gv corresponding to the power in the non-recording mode, and the parallel resistance value of the feedback resistor Rr and the feedback resistor Rv is the signal of the light receiving element in the non-recording mode and the output of the operational amplifier 701 is in the reproduction mode. Is determined to be the same value as in the case of.

When the recording / reproduction gain switching signal SG2 is turned on and the recording / reproduction gain switching signal SG1 is turned on, both of the analog switches 704 and 706 are turned on, so that the feedback resistors Rr, Rw, Rv The gain is set by the parallel resistance of. The gain at this time becomes a gain Gw corresponding to the power in the recording mode, and the feedback resistance R
r, the feedback resistance Rw and the parallel resistance value of the feedback resistance Rv are:
The output of the operational amplifier 701 is determined by the signal of the light receiving element at the time of recording so as to be the same output as at the time of reproduction. For example, when the ratio of the recording power Pw, the non-recording power Pv, and the reproduction power Pr is about 1: 10: 100, the gain at the time of reproduction, non-recording, and recording is set to 100: 10: 1.

FIG. 24 shows the configuration of the gain switching circuits 109 and 110. A feedback resistor Rf that determines an appropriate gain that does not saturate the operational amplifier with a light receiving element signal during reproduction is connected between the − input and the output of the operational amplifier 901. In this case, the gain switching is unnecessary as described above.

FIG. 25 shows the structure of the MPU 62.
Two MPUs 62-1 and 62-2 are used because an inexpensive MPU is used and the control is complicated. The MPU 62-1 mainly includes a scanning motor and an A
Control of hardware such as T and AF actuators, format information for recording one track from the host computer 1001 by dividing it into a plurality of sectors, and information from an encoder attached to a scanning motor (not shown) Pulse signal E indicating relative position information of the light spot
Processing such as generation of a recording / reproduction gain switching signal SG2 based on the NC is performed.

The MPU 62-2 generates a recording signal WD (= recording / reproduction gain switching signal SG1) corresponding to an information pit string corresponding to the format information and recording data from the host computer 1001, and generates a gain switching signal SG2. And output it so that it can be recorded in a desired sector. Further, the MPU 62-2 performs predetermined signal processing on the information reproduction signal at the time of reproduction to generate reproduction data, and transfers the reproduction data to the host computer 1001. Further, at the time of recording, the verifying signal is binarized, and this is compared with the recording signal to perform verification at the same time as recording.

FIG. 26 shows the operation in the case where one track is divided into a plurality of sectors and recorded in the above-described prior-art apparatus. FIG. 26A shows the relative moving speed of the optical card and the recording spot. The front and rear inclined portions are an acceleration region and a deceleration region, and a constant speed region is between them. Performs recording and playback in the constant speed area. When recording information, the host computer 1001 sends format information such as the number of sectors of a track to the MPU 62-1 and the format information and recording data to the MPU 62-2. The MPU 62-1 outputs the gain switching signal SG corresponding to the recording area of each sector of the optical card based on the format information as shown in FIG.
2 is output. In FIG. 26B, one track is divided into three sectors.

The MPU 62-2 generates a recording signal WD from the format information and the recording data.
It is output after detecting the rising of the gain switching signal SG2 as shown in FIG. FIG. 26C shows a recording signal WD when recording is performed in the first sector of the recording area divided into three. FIG. 26D shows a light emission waveform when the semiconductor laser 21 is driven by the LD driver of FIG. Information is recorded by switching between the non-recording light power Pv and the reproducing light power Pr with the gain switching signal SG2 and switching between the non-recording light power Pv and the recording light power Pw according to the recording signal WD. Here, the non-recording light power is provided between the reproducing light power and the recording light power, and this is for lowering the gain of the gain switching circuit during recording and non-recording. As a result, noise generated at the time of gain switching is reduced, and the S / N of the AT, AF control signal, and verification signal is improved. In particular, since the AT and AF control signals are differential signals, the influence of noise is low. However, the verifying signal is not a differential signal, and the effect of noise remains unchanged.

FIG. 26E shows a reproduced signal when the pits recorded in this manner are reproduced. When the pit is recorded, the reflectance of the optical card decreases, and FIG.
A reproduced signal as shown in (e) is obtained. In areas other than the recording pits, the reflectance does not decrease. FIG. 26 (f) shows a recording signal for recording in the center sector of the three divided recording areas, and FIG. 26 (g) shows a recording signal for recording in the last sector. When information is individually recorded in three sectors, scanning is performed at least three times, and each of the three divided sectors is irradiated with non-recording light power at least three times.

FIG. 27 shows the relationship between the number of irradiations when the same area of the organic recording medium is irradiated with the non-recording light power and the reflectance of the recording medium. As is clear from FIG. 27, the reflectance does not change when the number of irradiations is one, but the reflectance gradually decreases as the number of irradiations increases. Therefore, when an organic recording medium is used, if the non-recording power is irradiated three times, the reflectivity is reduced accordingly and the S / N of the reproduced signal is deteriorated. That is, as shown by the broken line in FIG. 26 (h), there is a problem that the level of the reproduction signal decreases in accordance with the decrease in the reflectance, and the S / N of the reproduction signal deteriorates. Also, 1
When a track is divided into three or more sectors, the number of times of non-recording light power irradiation also increases, and there is a problem that the S / N of the reproduction signal further deteriorates.

The present invention has been made in view of the above-mentioned conventional problems, and has as its object to provide an optical information recording apparatus capable of reducing noise generated at the time of gain switching and performing correct verification simultaneously with recording. .

Another object of the present invention is to provide an optical information recording apparatus in which the reflectance does not decrease even if the same track of the recording medium is scanned any number of times.

[0050]

SUMMARY OF THE INVENTION An object of the present invention is to provide a light source, means for dividing a light beam emitted from the light source into a plurality of light beams, and recording one of the divided light beams. Means for irradiating the recording medium as a verifying spot at a position following the other one of the recording spots with respect to the recording spot, modulating the recording spot according to a recording signal, and modulating the modulated recording spot. Means for recording information by scanning on an information track of a recording medium, a photodetector for receiving a signal of the verifying spot through the recording medium, and a gain switch for amplifying an output signal of the photodetector. Gain switching means for removing a component due to modulation of a recording spot by switching in accordance with a signal, and based on a verifying signal and a recording signal output from the gain switching means. Means for performing verification at the same time as recording, wherein the gain switching means switches a gain in accordance with an output signal of a delay means for delaying the gain switching signal. .

Another object of the present invention is to provide one light source, a first current source for supplying a current corresponding to a predetermined reproducing power to the light source, and a second current source for supplying a current corresponding to a recording power.
And a third current source for supplying a current corresponding to a non-recording power higher than the reproduction power and lower than the recording power, and the third current source is turned on in a recording area, and the third current source is turned on in response to a recording signal. Driving means for driving the light source by turning on and off a second current source; and recording information by scanning an information track on a recording medium with a light beam emitted from the light source and modulated by the driving means. Means for recording information by dividing an information track of the recording medium into a plurality of sectors, the non-recording power in an area other than a recording area of a target sector to be recorded. This is achieved by an optical information recording device having means for turning off the light.

[0052]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows the configuration of an optical information recording apparatus according to a first embodiment of the present invention.
In FIG. 1, the same parts as those of the conventional apparatus of FIG. That is, the semiconductor laser 21, the collimator lens 23, the diffraction grating 50, the polarization beam splitter 26, the quarter-wave plate 27, the objective lens 28, the spherical lens 29, the cylindrical lens 30, and the photodetector 31 are all the same as those in FIG. Is the same. The optical card 1 is shown in FIG.
The optical card 1 is mounted on a carriage (not shown). The carriage reciprocates in the information track direction by a drive mechanism (not shown), whereby the optical head and the optical card 1 reciprocate relatively in the track direction, and the light beam from the optical head scans the information track to thereby cause the information track to move. Recording or reproduction of recorded information.

The LD driver 61, MPU 62, addition and subtraction circuit 63, subtraction circuit 64, recording / reproduction gain switching circuit 65, and selection switch 66 are the same as those in FIG. The LD driver 61 shown in FIG. 16 is used, and the semiconductor laser 21 is driven by a positive power supply as in the conventional case. Therefore, the switch 203 uses a PNP transistor type. Each of the gain switching circuits 101 to 108 of the recording / reproduction gain switching circuit 65 uses the circuit of FIG. 17 and switches the gain according to the recording signal at the time of recording information, thereby outputting the output signal of each light receiving element of the photodetector 31. Are removed.

Further, in this embodiment, a delay circuit 67 for delaying the recording / reproduction gain switching signal output from the MPU 62 is provided. The delay circuit 67 is used to reduce spike noise generated at the time of gain switching by delaying the gain switching signal for a predetermined time as described later in detail. FIG. 2 shows a photodetector 3
1 shows a signal processing circuit that creates a verifying signal, an AT / AF control signal, and an information reproduction signal based on the output signal of No. 1. The signal processing circuit is exactly the same as the circuit of FIG. 14, and includes a photodetector 31, a recording / reproduction gain switching circuit 65, a selection switch 66, and addition and subtraction circuits (addition circuits 117, 118,
121, a subtraction circuit 120) 63, and a subtraction circuit 64. However, a gain switching signal is supplied from the delay circuit 67 to each of the gain switching circuits 101 to 108 in the recording / reproduction gain switching circuit 65.

FIG. 3 shows a specific example of the delay circuit 67. 3, 210 denotes a buffer for impedance conversion, R _D and C _D are resistors and capacitors for determining the delay time, 211 and 212 is a comparator. The comparator 211, a resistor R _D and a capacitor C _D consisting compares the output signal with a reference value V _ra of the low-pass filter, a comparator 212 the output signal of the low-pass filter and the reference value V
Compare _rb . The output signal of the comparator 212 is ORed with the recording signal WD by the OR gate 213 and input to the clear input (active low) of the D-type flip-flop 214. The output signal of the comparator 211 is input to the clock input (active at the rising edge) of the flip-flop 214.

FIG. 4 shows signals of various parts of the delay circuit 67. 4A shows a gain switching signal (recording signal WD) supplied from the MPU 62, and FIG. 4B shows a resistor _RD.
That the output signal of the low-pass filter comprising a capacitor C _D. The output signal of the low-pass filter is compared with a reference value V _ra (shown by a broken line in FIG.
It is output as _a binary signal WDa as shown in (c). 2
Valued signal WD _a rise time with respect to the recording signal TD
_a is late. The output signal of the low-pass filter is binarized by comparison with a reference value V _rb (shown in FIG. 4B) by a comparator 212 and output to an OR gate 213. In the OR gate 213, the comparator 212
Synthesizes and outputs the recording signal WD, and outputs a logical sum signal WD _b as shown in FIG. 4 (d). The signal WD _b falling to the recording signal WD is delayed by the time TD _b.

The output signal of the flip-flop 214 is shown in FIG.
High level at the rising edge of the signal WD _a (e), the changes to low level at the falling edge of the signal WD _b, the recording signal WD rise is delayed by the time TD _a relative time with respect to the fall of a recording signal WD TD _b the only delay the signal. Delay time TD _a, TD _b is the time constant of the resistor R _D and a capacitor C _D, the reference value V _ra, V
It can be set arbitrarily by adjusting _rb . In this way, gain switching signals delayed for a predetermined time are obtained and supplied to the respective gain switching circuits 101 to 108 of the recording / reproduction gain switching circuit 65.

Next, the operation at the time of recording information according to the present embodiment will be described with reference to FIG. The signal level due to the reflected light from the recording spot from the optical card 1 is A ₁₀ , the signal level due to the reflected light from the verifying spot is A ₁₁ , the power modulation degree of the semiconductor laser 21 during recording is W, and the modulation is due to the information pit. The degree will be described as P, and the influence of the transient response due to the gain switching of the recording / reproduction gain switching circuit 65 will be described as K. Further, when information is recorded, as shown in FIG.
1 to S5 are scanned on the optical card 1, information is recorded on the recording spot S3, and recorded information is reproduced on the verifying spot S2 or S4. Perform simultaneous verification.

First, FIG. 5A shows a recording signal waveform, and FIG.
(B) is a power modulation waveform of the recording spot. Since the light beam of the semiconductor laser 21 is divided into a plurality,
Other light spots are also subjected to similar power modulation.
FIG. 5C shows the gain switching signal WDD output from the delay circuit 67 of FIG. The gain switching signal time than the rise of the recording signal TD _a as described above, is delayed by time TD _b than falling. FIG. 5D shows the waveform of the verifying signal reproduced at the verifying spot preceding the recording spot. In order to make it easier to understand the noise reduction effect according to the present embodiment, a signal waveform reproduced from a preceding spot having no recording pit on an information track is shown.

FIG. 6 is an enlarged view of the signal of FIG. FIGS. 5A to 5D correspond to FIGS. 6A to 6D, respectively. In FIG. 6D, a signal shown by a broken line is a verifying signal waveform in the case of the conventional device, that is, a verifying signal waveform in the case where the delay circuit 67 is not provided. In this case, since FIG. 6D shows a signal reproduced at a spot preceding the recording spot, the modulation component due to the information pit is not included, and the verifying signal has a constant level by the gain switching operation. Signal
Become the only signal A ₁₁ by the reflected light of the spot for verification is ideal. However, in the case of the conventional device, a spike-like noise of K occurs in the verifying signal due to the delay of the output of the LD driver 61 as shown by a broken line in FIG. 6D. Note that the actual spike noise changes depending on the shape of the light modulation waveform, the ratio between the reproduction light and the recording light, and the rise and fall of the recording signal. However, in FIG. The spike-like noise is made the same at the falling edge.

On the other hand, in FIG. 6D, a signal indicated by a solid line indicates a verifying signal when the gain switching signal is delayed by the delay circuit 67. Here, when the gain is switched at the time of rising of the recording signal (switching from the reproduction light to the recording light), the light modulation waveform does not reach the recording power due to the delay of the LD driver 61 as shown in FIG. , the gain switching operation of the gain switching circuit is delayed by the amount of time TD _a gain of the gain switching circuit maintains the gain at the time of reproduction power. Therefore, the period of time TD _a even if no optical modulated waveform reaches to the recording power, since the delayed gain switching operation of the gain switcher, not the output signal of the light receiving elements of the photodetector 31 is reduced As shown in FIG. 6D, spike noise can be reduced. In this case, the delay circuit 67
The delay time of the gain switching signal due to the above is the verifying signal level A at the time when the gain is switched as shown in FIG.
_It is desirable to set so that the upper and lower peak values of the spike noise are the same around ₁₁ or the areas of the positive and negative spike noises are the same. By doing so, spike noise can be minimized.

[0062] Furthermore, when at the fall of a recording signal (switching from recording light to the reproducing light) switching the gain, as well the gain switching of the gain switching circuit is delayed by a time TD _b, the output of the LD driver 61 Even if the optical power does not reach the reproducing power due to the delay, the gain of the gain switching circuit maintains the gain at the recording power. Therefore, the period of time TD _b is the gain is low, never verifying signal is high, it is possible to reduce the spike noise as shown in FIG. 6 (d). Again,
Delay time TD of gain switching signal by delay circuit 67
_It is desirable that _b is set so that the upper and lower peak values of the spike noise are the same or the upper and lower areas are the same around the signal level of the verifying signal at the gain switching timing as shown in FIG. .

Returning to FIG. FIG. 5E shows a verifying signal when only the modulation component due to the information pit is received. When this is binarized, a binarized signal corresponding to the recording signal can be obtained as shown in FIG. FIG. 5F shows a verifying signal reproduced at a verifying spot subsequent to the recording spot. The verifying signal includes a modulation component due to information pits recorded in the recording spot and a noise component reduced as shown in FIG. The verifying signal is sent to the MPU 62 and binarized as shown in FIG. In binarization, the slice level has a hysteresis width corresponding to the residual noise as shown in FIG. In the MPU 62, the recording signal and the verification signal
The digitized signals are compared, and verification is performed simultaneously with recording.

In the present embodiment, the delay circuit 67 is provided to delay the gain switching signal.
1 can reduce spike noise due to the delay of the output. Therefore, a pseudo signal due to noise does not occur in the binary signal obtained by binarizing the verifying signal, and the information signal width corresponding to the information pit does not change. A binary signal can be obtained. As a result, it is possible to prevent a situation in which a verify error occurs even though information is accurately recorded, and verify can be performed accurately.

Next, a second embodiment of the present invention will be described. In the first embodiment, the gain switching signal is delayed at both the rise and fall of the recording signal.
Depending on the characteristics of the LD driver 61, output of only one of the rising edge and the falling edge may be delayed. For example, there is a delay at the rise of the light modulation waveform due to heat generated by a drive current in the LD driver, but there is no delay at the fall. Further, since the gain ratio between recording and reproduction is large, spike-like noise hardly occurs at the rising edge of the optical modulation waveform, but large spike-like noise may occur at the falling edge.

FIG. 7 shows a configuration of the delay circuit 67 applicable to such a case. In FIG. 7, 210
Is a buffer for impedance conversion, and R _D and C _D are a resistor and a capacitor that determine the delay time. The comparator 211 binarizes the output of the low-pass filter composed of the resistor R _D and the capacitor C _{D with} the intermediate value of the output voltage, and the binarized signal is ORed with the recording signal WD by the OR gate 215. At 216, the logical product is calculated with the recording signal WD.

FIG. 8 shows signals of various parts of the delay circuit of FIG. FIG. 8A shows a recording signal (gain switching signal).
WD, FIG. 8B shows an output signal of the low-pass filter. The output signal of the low-pass filter is output to an intermediate value V by a comparator 211.
_r and is output as a binary signal WDD as shown in FIG. The output signal of the comparator 211 is combined with the recording signal WD by the OR gate 215, and as shown in FIG. 8D, a signal WDDF whose only falling edge is delayed by the time TD from the recording signal is output. Also, comparator 2
The output signal 11 is ANDed with the recording signal by the AND gate 216, and a signal WDDR whose rising edge is delayed by the time TD from the recording signal is output as shown in FIG.

Therefore, when the gain switching signal is delayed only at the time of falling of the recording signal due to the characteristics of the LD driver 61, the output signal WDDF of the OR gate 215 is used as a gain switching signal and is output to each gain switching circuit. When the gain switching signal is delayed only at the time of rising of the recording signal, the output signal WD of the AND gate 216 is output.
DR is used as a gain switching signal and output to each gain switching circuit. FIG. 8F shows a verifying signal when the gain switching signal is delayed at the rise of the recording signal, and FIG. As described above, in the present embodiment, the gain switching signal is delayed by delaying only one of the rising edge and the falling edge of the recording signal.
It is possible to reduce spike noise generated in the verifying signal according to the characteristics of the D driver.

In the first and second embodiments, when the frequency component of the spike noise is higher than the frequency component of the verifying signal, filtering is performed by a low-pass filter that reduces the spike noise component. Then, by performing binarization, the reliability of verification can be further increased. In the above embodiment, the gain switching signal is delayed by using the low-pass filter. However, the gain switching signal may be delayed by a predetermined time by using a clock oscillator and a counter that counts clocks.
With such a configuration, the delay time can be set with high accuracy with respect to environmental changes and temporal changes.

Further, in the above embodiment, the apparatus using an optical card as a recording medium has been described as an example, but the present invention can be applied to an apparatus using an optical disk, a magneto-optical disk or the like as a recording medium. In this case, since the rotating direction of the disk recording medium is constant and the scanning direction of the light spot is one direction, the selection switch is not necessary. This is the same when information is recorded by scanning the optical spot in one direction in the optical card. In the above embodiments, the spike noise generated due to the delay of the output of the LD driver is described as being reduced. However, the present invention may also be applied to the noise generated by the delay of the output of the gain switching circuit and the gain switching circuit. By setting the delay time to an optimum value, it is possible to reduce the charge injection noise generated by turning on and off the analog switch inside the switch.

Next, a third embodiment of the present invention will be described. The present embodiment is intended to prevent the reflectance of the optical card from decreasing due to the irradiation of the non-recording light power as described above. The overall configuration of the optical information recording apparatus of the present embodiment is the same as that of FIG. 13, and the optical card of FIG. 11 is used as a recording medium. However, the light beam of the semiconductor laser 21 is divided into seven light beams using the diffraction grating 50 of FIG.
As shown in FIG. 19, seven light spots S1 to S
Irradiation 7 is used to perform recording, reproduction, and verification at the same time as recording. Further, the circuit of FIG. 21 is used as the signal processing circuit, the circuit of FIG. 22 is used as the LD driver 61, and the circuit of FIG. 23 is used as the gain switching circuits 101 to 108 in the recording / reproduction gain switching circuit 65. 24 are used as the switching circuits 109 and 110, and when recording information, the semiconductor laser 21 is switched between recording light power and non-recording light power to record information.

FIG. 9 shows the configuration of the MPU 62 used in this embodiment. In FIG. 9, the same parts as those in FIG. 25 are denoted by the same reference numerals. In FIG. 9, the MPU 62 is 62-1,
62-2, which is composed of two MPUs.
Reference numeral 1 indicates a recording area on the optical card 1 by controlling hardware, counting format information from a host computer 1001 of a higher-level control device, and counting pulse signals ENC of an encoder attached to a scanning motor (not shown). A recording area signal WZ is generated. MPU62-2,
A recording signal WD (= recording / reproduction gain switching signal SG1) corresponding to the information pit string is generated according to the format information and recording data from the host computer 1001,
In addition, a recording signal WD is output so that recording can be performed in a desired sector with reference to the recording area signal WZ from the MPU 62-1. The MPU 62-2 further performs predetermined signal processing on the information reproduction signal at the time of information reproduction, generates reproduction data, transfers the data to the host computer 1001, binarizes the verifying signal reproduced at the same time as recording at the time of information recording, This is compared with the recording signal to perform verification at the same time as recording.
And other processes.

Reference numeral 1002 denotes a D-type flip-flop. The D terminal is fixed at a high level. The recording signal WD is input to the clock terminal (CLK), and the recording area signal WZ is input to the clear terminal (CLR). Flip-flop 1
An output Q of 002 indicates a selected recording area of the optical card 1, and is output as a gain switching signal SG2. That is, when the flip-flop 1002 detects the rising edge of the recording signal WD, the output Q is at a high level, that is, the gain switching signal SG2 is turned on. When the recording area signal WZ is turned off, the output Q operates at a low level, that is, SG2 is turned off. The gain switching signal SG2 is sent to the switch 805 of the LD driver in FIG. 22 and the analog switch 706 of the gain switching circuits 101 to 108 in FIG.

Next, the operation of this embodiment will be described in detail with reference to FIG. In this embodiment, one track of the optical card 1 is divided into three sectors, and information is recorded in the first sector among them. First, FIG.
(A) shows the relative moving speed of the optical head and the optical card 1 in the track direction. The horizontal axis represents the distance of the optical card 1 in the track direction, and the vertical axis represents the relative scanning speed. MPU62
-1 receives a recording instruction from the host computer, moving controls the scanning motor starts acceleration of the optical card 1 from the stop position L _0, the optical card 1 when L ₁ reaches a predetermined speed at a constant speed Speed control. At this time, MP
U62-1 counts the pulse signals ENC of the encoder to measure the moving distance from the stopping position L _0.

Further, the MPU 62-1 generates a recording area signal WZ based on the moving distance and the format information from the host computer, and as shown in FIG. 10B, L ₂ − corresponding to the recording area of three sectors. L ₃ , L ₄ −L ₅ ,
The recording area signal WZ is set to a high level between L _{6 and} L ₇ .
Here, during the period of L ₀ -L ₂ , the gain switching signal SG2 is off as shown in FIG.
Switches 803 and 805 of the semiconductor laser 21 are turned off.
, Only the current Ir of the current source 802 is supplied, and the semiconductor laser 21 emits light with the reproduction light power Pr as shown in FIG. Next, when the recording area signal WZ is turned on first, L ₂
, The output of the flip-flop 1002 becomes high level, and the gain switching signal SG2 becomes the level shown in FIG.
It turns on like this. In the MPU 62-2, L ₂
When the rise of WZ is detected at the position of, the recording data transferred from the host computer 1001 is
As shown in (c), a recording signal WD corresponding to the information pit string is generated and output to the LD driver 61.

When the gain switching signal SG2 is turned on, L
The switch 805 of the D driver is kept on, and the switch 801 is turned on and off in accordance with the recording signal WD.
While the recording signal WD is off, the current I
v and Ir and the currents Iv and I while the recording signal WD is on.
The total current of r and Iw is supplied. As a result, the semiconductor laser 21 outputs the recording signal WD as shown in FIG.
Is off at non-recording light power Pv, and when the recording signal WD is on, light is emitted at the recording power Pw, and information is recorded by scanning this recording spot on the head sector of the track of the optical card 1. On the other hand, the gain switching signal SG
1 and SG2 are supplied to the respective gain switching circuits 101 to 108, and switches 704 and 70 are provided in accordance with SG1 and SG2.
6, the power modulation component due to the modulation of the recording spot is removed, and an AT, AF control signal, and a verification signal are generated. As described above, the MPU 62-2 binarizes the verifying signal and compares it with the recording signal to perform verifying at the same time as recording.

[0077] MPU62-1 after the output of the recording signal WD, detects that it has reached the position of L _3, is determined to have reached the end of the recording area of the first sector, recording as shown in FIG. 10 (b) The area signal WZ is turned off. When WZ is turned off, the output of the flip-flop is cleared.
The gain switching signal SG2 turns off as shown in FIG. As a result, the switch 805 of the LD driver is turned off,
Since only the current Ir is supplied to the semiconductor laser 21, the semiconductor laser emits light with the reproduction light power Pr as shown in FIG. Next, when MPU62-1 detects the position of L _4, is determined to have reached the recording area of the second sector, although on the WZ as in FIG. 10 (b), except the first sector in the scanning , The MPU 62-2 does not output a recording signal. Therefore, the gain switching signal SG2
Is not turned on, and as shown in FIG. 10E, in the section between L _{4 and} L ₅ , the semiconductor laser 21 emits light not with the non-recording light power but with the reproduction light power Pr.

[0078] Further, at the position of L _6, is determined to have reached the recording area of the third sector, is to turn on the WZ, does not record other than the first sector in the same manner, the recording signal is not output. Therefore, SG2 does not turn on similarly,
In the section L ₆ -L ₇ , the semiconductor laser 21 emits light with the reproduction light power Pr. Then, MPU62-1 comes to the position of L _8, to begin deceleration of the optical card and controls the scanning motor, is stopped at the position of L ₉ to end the recording of the sector of the section L ₂ -L _3. Further, when the sector recorded in this manner is scanned with the reproducing light power Pr, FIG.
A reproduced signal as shown in (f) can be obtained.

Next, when a recording command is issued again from the host computer, the MPU 62-1 starts scanning on the same track and outputs a recording area signal WZ as shown in FIG. Further, when the recording data in MPU62-2 is transferred, the sector of the section L ₂ -L ₃ is already recorded, in order to perform recording in a sector of the next interval L ₄ -L _5, two WZ Detect eye rising. Upon detection of the rising at the position of L _4, two by 10 the output of the recording signal WD starts as (g), it switches the semiconductor laser 21 to the non-recording power and the recording power in accordance with a recording signal eye The recording is performed on the sector. The gain switching signal SG2 even during scanning is turned only in the section L ₄ -L _5, and in the other regions reproducing light power is radiated.

[0080] Further, when a recording command from the host computer is issued, the recording signal WD in the next section L ₆ -L ₇ as shown in FIG. 10 (h) is outputted from the MPU62-2, gain switching signal SG2 also section It turns on only at L ₆ -L ₇ . As a result, recording is performed in the sector of the section L ₆ -L ₇ . Also in this case, since SG2 is turned on only between L _{6 and} L ₇ , the reproducing light power is irradiated in other areas. As described above, in the present embodiment, since the gain switching signal SG2 is turned on only in the area of the sector to be recorded, the non-recording light power is not irradiated to the area other than the sector to be recorded. Therefore, even if the same track is scanned a plurality of times and recorded in each sector, the reflectance of the optical card does not decrease, and a normal reproduction signal can be obtained as shown in FIG. / N can be prevented from deteriorating.

In the above embodiment, the D-type flip-flop is used to generate the gain switching signal SG2 for selecting the recording area of the desired sector.
It is also possible to generate them directly by the PU 62-2. Also,
The operation when one track is divided into a plurality of sectors and information is recorded in one of the sectors has been described, but it is also possible to record in a plurality of sectors by one scan. In this case, upon receiving a recording command and format information from the host computer, the MPU 62-1 starts scanning a target track, and outputs a plurality of recording area signals according to the format information. On the other hand, MPU62-
In step 2, a rising edge of the recording area signal is detected, recording areas of a plurality of sectors to be recorded are selected, and a recording signal is output. By outputting a plurality of recording signals in this manner, it is possible to record on a plurality of sectors by one scan.

[0082]

As described above, according to the present invention, since the gain is switched by delaying the gain switching signal, spike-like noise of the verifying signal can be reduced, whereby the verifying signal can be reduced. No pseudo signal is generated when binarizing is performed, and the verify at the same time as the recording can be correctly performed. When recording information by dividing an information track into a plurality of sectors,
By turning off the non-recording power in an area other than the recording area of the target sector, even if the same track is scanned a plurality of times, the reflectance of the recording medium does not decrease, and the S / N of the reproduction signal is prevented from deteriorating. it can. In particular, when an organic recording medium is used, it is effective because the reflectance does not decrease even after scanning many times.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a first embodiment of an optical information recording apparatus of the present invention.

FIG. 2 is a circuit diagram showing a signal processing circuit of the embodiment of FIG.

FIG. 3 is a circuit diagram showing a delay circuit according to the embodiment of FIG. 1;

FIG. 4 is a diagram showing signals of respective parts of the delay circuit of FIG. 3;

FIG. 5 is a time chart for explaining the operation of the embodiment of FIG. 1;

FIG. 6 is an enlarged view of a part of the signal of FIG. 5;

FIG. 7 is a circuit diagram showing a delay circuit used in a second embodiment of the present invention.

FIG. 8 is a diagram showing signals of respective parts of the circuit of FIG. 7;

FIG. 9 is a diagram illustrating a configuration of an MPU used in a third embodiment of the present invention.

FIG. 10 is a time chart for explaining the operation of the embodiment in FIG. 9;

FIG. 11 is a plan view of the optical card.

FIG. 12 is a view showing a light spot applied to the optical card of FIG. 11;

FIG. 13 is a diagram showing a conventional optical information recording / reproducing apparatus.

FIG. 14 is a diagram showing a signal processing circuit of the device of FIG.

FIG. 15 shows a diffraction grating of the apparatus of FIG.

FIG. 16 is a circuit diagram of an LD driver of the device of FIG.

FIG. 17 is a circuit diagram of a gain switching circuit of the device of FIG.

FIG. 18 is a diagram for explaining a problem of the device of FIG. 13;

FIG. 19 is a diagram showing a light spot irradiated on an optical card in the device of the prior application.

FIG. 20 is a diagram showing a diffraction grating used in the device of the prior application.

FIG. 21 is a diagram showing a signal processing circuit of the device of the prior application.

FIG. 22 is a circuit diagram of an LD driver of the device of the prior application.

FIG. 23 is a circuit diagram of a gain switching circuit of the device of the prior application.

FIG. 24 is a circuit diagram of a gain switching circuit for RFR and RFL of the device of the prior application.

FIG. 25 is a diagram showing a configuration of an MPU of the device of the prior application.

FIG. 26 is a diagram for explaining a problem of the device of the prior application.

FIG. 27 is a diagram showing characteristics of an organic recording medium.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Optical card 21 Semiconductor laser 28 Objective lens 31 Photodetector 61 LD driver 62, 62-1, 62-2 MPU 65 Recording / reproduction gain switching circuit 67 Delay circuit

Claims (4)

[Claims] 1. A light source, means for splitting a light beam emitted from the light source into a plurality of light beams, one of the split light beams for a recording spot, and the other for a recording spot Means for irradiating the recording medium as a verifying spot at a position following the spot, modulating the recording spot according to a recording signal, and scanning the modulated recording spot on an information track of the recording medium. Means for recording information, a photodetector for receiving a signal of the verifying spot through a recording medium, and a recording spot by switching a gain for amplifying an output signal of the photodetector in accordance with a gain switching signal. Gain switching means for removing a component due to modulation of the signal, and means for simultaneously performing recording and verification based on a verifying signal and a recording signal output from the gain switching means. Wherein the gain switching means comprises:
An optical information recording apparatus, wherein a gain is switched according to an output signal of a delay means for delaying the gain switching signal. 2. The optical information recording apparatus according to claim 1, wherein said delay means delays the rise and fall of the gain switching signal independently of each other. 3. The optical information recording apparatus according to claim 1, wherein said delay means delays one of a rising edge and a falling edge of the gain switching signal. 4. One light source, a first current source for supplying a current corresponding to a predetermined reproducing power to the light source, a second current source for supplying a current corresponding to a recording power, and a larger power than the reproducing power. A third current source for supplying a current corresponding to a non-recording power smaller than the recording power; turning on the third current source in a recording area; turning on the second current source in response to a recording signal; Optical information comprising: driving means for driving the light source by turning off the light source; and means for recording information by scanning an information track on a recording medium with a light beam emitted from the light source and modulated by the driving means. In a recording apparatus, when information is recorded by dividing an information track of the recording medium into a plurality of sectors, the non-recording power is erased in an area other than a recording area of a target sector to be recorded. An optical information recording device comprising means for lighting.