JPH0434732A - Optical information recording and reproducing device - Google Patents

Abstract

PURPOSE:To securely prevent malfunction due to off-track, etc., by providing a timing means for changing a gain of a gain changeover means from a prescribed gain at the time of recording reproducing to a desired gain when a coincidence signal to be sent out by a comparison means and a control signal to be sent out by a control means are both inputted. CONSTITUTION:The control signal 56 is inverted by an inverter 58, and is inputted as a control signal to an AND gate 59 by a timing circuit 54. Then, the coincidence signal 55 inverted by an inverter 60 is inputted to a D flip-flop circuit 61, and when a toggle-outputted signal is inputted to the AND gate 59, it is logically multiplied by the AND gate 59, and a timing signal 57 is sent out to gain changeover circuits 48 and 50 to make a gain change. At the time of starting reciprocating motion of an optical card, the gain is set higher at the time of stopping, while the gain is set lower at the time of recording and reproducing data. By this method, malfunction due to transitional vibration caused by the reciprocating motion of a card-like optical information recording carrier, etc., or dust and dirt, etc., on a recording surface can be prevented.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to an optical information recording/reproducing device for optically recording or reproducing information on an optical information recording carrier, and particularly relates to an optical information recording/reproducing device for optically recording or reproducing information on an optical information recording carrier. The present invention relates to an optical information recording/reproducing device suitable for.

(Prior Art) As an optical information recording carrier, there is, for example, a card-shaped recording carrier (hereinafter referred to as an optical card) disclosed in Japanese Patent Application No. 1-287996 filed by the applicant. The structure of an example of this optical card is shown in FIG.

This optical card 1 has storage areas of a predetermined width called tracks arranged in parallel in a plurality of stages in the longitudinal direction (hereinafter referred to as the track direction) of the main surface.

This track 2 is formed by dividing data parts 4a and 4b into two in the track direction, in which pits for recording data are formed, and seek parts 3a and 3b are formed at both ends thereof, and a seek part 3C is formed in the center part. has been done. Further, track numbers are recorded in the seek sections 3a, 3b and 3C, respectively, so that data can be easily searched. Here, the direction perpendicular to the track direction is defined as the theta direction.

Further, above the data section 4a, a card drive pattern 4bl is provided which defines the area width for reciprocating the data section 4b in the track direction, and below the data section 4b, the data section 4a is moved back and forth in the track direction. A card drive pattern 4al is provided that defines the width of the area to be reciprocated.

This optical card 1 records data by irradiating the track 2 with a light beam such as a laser. When reading out the data, the data is read out by irradiating a light beam and converting the presence or absence and strength of the reflected light into electrical signals.

Next, FIG. 5 shows an area A surrounded by dotted lines on the recording surface of FIG. 4, and the structure of track 2 will be explained.

The track 2 is divided into a seek section 3a and a data section 4a. The data section 4a includes a clock pattern 6 recorded in advance in the center of the clock/servo line 5.
Data bits 5A-1 to 5A-16, which can store data 5A of 8 bits each (16 bits in total), are arranged on both sides of the bit.

Next, FIG. 6 shows an optical information recording carrier such as a disk, for example, a compact disk (CoIIlpact disk).
.

For example, an optical information recording/reproducing apparatus for recording or reproducing data on a CD (hereinafter abbreviated as CD) has a structure such as that disclosed in Japanese Patent Application Laid-Open No. 1172-1983 published in the official gazette. This will be explained with reference to a block diagram showing this. Although the present invention uses an optical card as the optical information recording carrier, the configuration and operation of the optical information recording and reproducing apparatus will be explained using an optical information recording and reproducing apparatus suitable for CDs and the like as a conventional example. do.

First, the optical pickup 9 that records or retrieves data from the CD 8 rotated by the rotation drive unit 7 is a general type, and uses a light beam generated from a light source 11 such as a semiconductor laser driven by a light source drive circuit 10. The collimator lens 12 polarizes the light so that it becomes parallel, and after passing through the polarizing beam splitter 13, the objective lens 14
The light is focused and irradiated onto the recording surface of the CD 8 to physically change the recording surface to form bits and the like to record information. The light beam is moved by a drive section 15 that moves the optical pickup 9 itself.

When information recorded on the CD 8 is retrieved, the light reflected from the recording surface is polarized by the polarizing beam splitter 13 and detected by the photodetector 16. The light detected here is converted into an electrical signal and sent to the demodulation circuit 17 as a detection signal. When the detection signal is input, the demodulation circuit 17 generates a reproduction signal 18 which is a recording and reproduction signal.
Output.

Further, the detection signal from the CD 8 is input to the demodulation circuit 17, and is also sent to a tracking control system and a focus control system, and is used for tracking control and focus control, respectively.

In the tracking control system, first, a tracking error signal (hereinafter referred to as TES) detection circuit 19 receives the detection signal from the photodetector 16, and sends a tracking error signal 20 to a gain control circuit 21 and a control circuit 22.

The gain control circuit 21 is a circuit that has a plurality of gains and switches the gains so that the input tracking error signal 20 has a predetermined output level.

The control circuit 22 is a circuit that controls the gain value switching operation of the gain control circuit 21 according to the input level of the tracking error signal 20.

Next, the tracking error signal 20 at a predetermined output level is sent to the phase compensation circuit 23, and after compensating the phase, it is input to the drive circuit 24.

Based on the phase-compensated tracking error signal 20, the drive circuit 24 drives the objective lens 1 using a tracking coil 25 provided in the optical pickup 9.
4 in the seek direction (in this case, in the direction perpendicular to the tangent to the track), the deviation in the irradiation position is corrected so that the light beam irradiates along the tracks of the rotating CD.

In the focus control system, first, a focus error signal (hereinafter referred to as FES) detection circuit 26 receives the detection signal of the photodetector 16 and sends out a focus error signal 27 to the gain control circuit 28 and the control circuit 22. do. This gain control circuit 28 includes the gain control circuit 21
It is equivalent to

Therefore, similarly to the tracking control described above, the focus error signal 27 at a predetermined output level is transmitted to the phase compensation circuit 29.
After the phase is compensated, the signal is input to the drive circuit 30.

Based on the focus error signal 27, the drive circuit 30 drives the objective lens 14 back and forth in a direction perpendicular to the recording surface of the CD 8 using a focus coil 31 provided in the optical pickup 9, so that the recording surface Focus the light beam on.

Gain control in this optical information recording and reproducing device is as follows:
In general, the higher the gain, the higher the resistance to vibration, and the less likely malfunctions will occur; however, malfunctions may occur due to dust, dirt, scratches, etc. attached to the recording surface of the CD8.

On the other hand, if the gain is lowered, malfunctions will not occur due to dust or the like adhering to the recording surface, but malfunctions will occur due to vibrations. Therefore, by switching the gain, an appropriate gain can be set depending on the situation.

Next, FIGS. 7a and 7b show the structure of a conventional drive device for reciprocating the optical card 1 as seen from the front and side.

In this device, a seek motor 36 is provided on a main body frame 35, and a lead screw 38 is connected via a drive transmission section 37.
Rotate. An optical pickup 9 is attached to the lead screen L-38, and the above-mentioned theta direction f
make a reciprocating motion.

Furthermore, a guard motor 39 is provided on the main body frame 35, and rubber rollers 41a, 41 are connected via a drive transmission section 40.
b is rotated, and the optical card 1 mounted so as to be in contact with these is reciprocated in the track direction e, and data for one stage of the track 2 is read by the light beam 42 of the optical pickup 9. This can be expressed as the theta direction f
By combining this with the reciprocating movement of , the data divided into two parts of the optical card 1 placed on the main body frame 35 can be read by the first pickup 9 .

Furthermore, this drive device requires shortening the length of the seek section in order to increase the capacity of the data section 4 of the optical card 1.
Starts up and stops quickly.

(Problem 8 to be solved by the invention) However, the conventional optical information recording/reproducing device shown in FIG.
This is not necessarily suitable for an optical information recording/reproducing device having a drive unit for reciprocating an optical card as shown in the figure.

That is, after a CD or the like is fixed to a drive system and starts rotating, data is recorded or reproduced while driving at a constant speed without stopping midway. In other words, when the gain must be controlled, it is mainly for vibrations caused by external disturbances and dirt and scratches that adhere to the storage surface. This gain control is started after a problem such as vibration occurs.

Therefore, the vibrations generated by the above-mentioned disturbances are vibrations that are applied to the entire apparatus, and there are very few cases where the CD itself, which is fixed to the drive system, vibrates and directly changes the distance between the recording surface and the pickup.

However, in an optical information recording/reproducing device in which recording or reproduction is performed by reciprocating an optical card, the vibrations generated at the start and stop of the reciprocating motion directly change the distance between the recording surface of the optical card and the pickup. , a focus error signal and a tracking error signal including large overcurrent are generated,
Even if gain switching is performed after a problem occurs in the gain control described above, an overcurrent may already flow, damaging the coil that drives the objective lens.

Therefore, by switching the gain before a foreseeable problem such as vibration occurs, it is possible to protect the coil more safely and more reliably prevent malfunctions due to off-track.

Accordingly, the present invention aims to protect the card-shaped optical information recording carrier from vibrations generated during reciprocating motion and transient large currents without causing malfunction, and provides an optical system suitable for the card-shaped optical information recording carrier. The purpose of the present invention is to provide an information recording and reproducing device that can be used to record and reproduce information.

(Means for Solving the Problems) In order to achieve the above object, the present invention reciprocates a card-shaped optical information recording carrier to optically record information on the card-shaped optical information recording carrier. an optical pickup means for reproducing, a tracking servo means for controlling a light beam irradiated onto an optical information recording carrier to follow a track, a gain switching means for changing a servo gain sent out by the tracking servo means, and the pickup means. a counting means for counting clock signals based on information on the clock signal; and a comparing means for comparing the count number of the clock signal of the counting means with a plurality of predetermined count numbers and sending out a match signal when the numbers become the same; a control means for sending out a control signal based on the reciprocating drive of the card-shaped optical information recording carrier; and the gain switching means when both the coincidence signal sent from the comparison means and the control signal sent from the control means are input. It is possible to provide an optical information recording/reproducing apparatus including timing means for changing the gain of the optical information from a predetermined gain during recording/reproducing to a desired gain.

(Function) By using the optical information recording and reproducing device configured as above,
It is possible to reliably set the gain high when starting and stopping the reciprocating movement of the optical card, and set the gain low when the optical card is at constant speed, that is, when recording and reproducing data.

Furthermore, transient overcurrent can be cut off by the driving means that stops servo driving when a track servo abnormality or a focus servo abnormality is detected on the input side of the driving circuit for driving the objective lens.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of an optical information recording/reproducing apparatus according to an embodiment of the present invention. Here, the same reference numerals are given to the same members as in the conventional optical information recording/reproducing device, and detailed explanation thereof will be omitted.

This optical information recording/reproducing apparatus is provided with a card motor drive system 44 for reciprocating the optical card 1 in the track direction as described above in FIG. 7, and a seek motor drive system for similarly driving the optical pickup 9 in the theta direction. A system 45 is provided, each of which is controlled and driven by a control circuit 46. The control circuit 46 also receives a card drive signal 47 from the card motor drive system 44 that indicates the speed state at which the card 1 is being driven.

In this optical information recording and reproducing apparatus, the tracking control system includes a TES detection circuit 19 connected to a gain switching circuit 48, and when a detection signal from the photodetector 16 is input manually, a tracking error is detected from the TES detection circuit 19. Signal 20 is sent to gain switching circuit 48.

This gain switching circuit 48 is a circuit that switches the gain and outputs a predetermined value so that the input tracking error signal 20 becomes a predetermined output level. , normal (L) level gain switching operation is controlled.

Next, the gain switching circuit 48 is connected to the phase compensation circuit 23, and the phase compensation circuit 23 is further connected to the analog switch 4.
It is connected to the drive circuit 24 via 9.

From this, the tracking error signal 20 at a predetermined level is sent to the phase compensation circuit 23 , and after the phase is compensated for, it is input to the drive circuit 24 via the analog switch 49 .

The drive circuit 24 drives the objective lens 14 in the theta direction within the linear range of the tracking error signal 20 by a tracking coil 25 provided in the optical pickup 9 based on the phase-compensated tracking error signal 20. Then, when the optical card 1 is driven in the track direction, the irradiation position of the light beam is corrected so that the light beam is irradiated along the track 2. The analog switch 49
is connected to a control circuit 46 to control its on/off operation.

In the focus control system, first, the FES detection circuit 26 is connected to a gain switching circuit 50, and a focus error signal 27 is sent to the gain switching circuit 50 from the FES detection circuit 26 into which the detection signal of the photodetector 16 is manually input. be done.

This gain switching circuit 50 includes the gain switching circuit 4
8, and the input focus error signal 27
This circuit switches and outputs the gain value so that the output level becomes a predetermined output level, and the gain switching operation between H and L levels is controlled by a timing circuit 54, which will be described later.

Next, the gain switching circuit 50 is connected to a phase compensation circuit 29, and the phase compensation circuit 29 is further connected to the analog switch 5.
1 to the drive circuit 30.

Therefore, the focus error signal 27 at a predetermined level is sent to the phase compensation circuit 29 to compensate for the phase, and then input to the drive circuit 30 via the analog switch 51.

The drive circuit 30 is connected to a tracking coil 31 provided in the optical pickup 9, and drives the tracking coil 31 based on the phase-compensated focus error signal 27.
By driving the optical card, the objective lens 14 is driven in a direction perpendicular to the recording surface of the optical card, and the light beam is focused on the recording surface. Further, the analog switch 51 is connected to the control circuit 4.
6 to control the on/off operation.

Next, a counter 52 is connected to the demodulation circuit 17 and counts the number of clocks of the clock signal 18b generated according to the clock pattern 6 shown in FIG.

The counter 52 is connected to the P terminal of the comparator circuit 53 and sends a count number P of data. and the comparison circuit 5
3, the count numbers M and N designated from the Q terminal are recorded in advance, and when the count number P matches the set count numbers M and N, the output terminal of this comparison circuit 53 It sends a coincidence signal 55 to the timing circuit 54 connected to it.

Here, the count number M indicates the number of clocks corresponding to a sufficient distance from the activation start position of the optical card 1 to the data section 4 until it is driven at a constant speed, and the count number N indicates the number of clocks corresponding to a sufficient distance from the activation start position of the optical card 1 to the data section 4. It shows the tarok number corresponding to the distance to the stop position of card 1.

Further, the control circuit 46 is connected to the input terminal of the timing circuit 54, and a control signal 56 is input thereto.

This timing circuit 54 is connected to the gain switching circuit 48.
．． 50 respectively, the coincidence signal 55 and the control signal 5
By timing signal 57 based on 6, gain H, L
Level gain switching is performed.

Next, the gain switching operation of the optical information recording/reproducing apparatus configured as described above will be explained with reference to the timing chart of FIG. 2.

In such an optical information recording/reproducing apparatus, after performing focus servo, the optical pickup 9 is moved in the theta direction by the seek motor drive system 45, detects a target track, and stops. At the same time, in order to start tracking control, the control circuit 46 outputs a control signal 56a, turns on the analog switch 49, and closes the tracking servo loop. Further, the control signal 56a is also sent to the timing circuit 54, and changes the timing signal 57a from L level to H level as shown. Due to this change in timing signal 57, the gain of gain switching circuit 48 is set to H level.

Next, when the card motor drive system 44 is started and the optical card 1 is driven in the track direction, the clock signal 18b is generated together with the card drive signal 47a, and the counter 52 counts the number of clocks of the clock signal 18b. The number P is sent to the comparator 53.

Then, when the count number P becomes the same as the preset count number M, the comparator 53 controls the timing circuit 5
4, and sends the match signal 55a to the next clock signal 18.
The input of signal b stops sending out the coincidence signal 55a and returns to the H level.

In response to this coincidence signal 55a, a timing signal 57b is sent from the timing circuit 54 to the gain switching circuit 48, the gain is returned from the H level to the L level (normal level), and data recording/reproduction is performed. .

Next, before reaching the seek section on the opposite side, when the count number P counted by the counter 52 becomes the same as the preset count number N, the comparator 53 sends a match signal 55b to the timing circuit 54. Then, the next clock signal 1
8b, the transmission of the L level match signal 55b is stopped and returns to the H level.

In response to this coincidence signal 55b, a timing signal 57c is sent from the timing circuit 54 to the gain switching circuit 48, and the gain is changed from the L level to the H level. Thereafter, when the light beam irradiation position reaches the seek section on the opposite side of the first card 1, the card motor drive system 44 stops and the card drive signal 47b disappears.

When a series of data recording/reproducing drive operations are completed, the control circuit 46 sends an H-level control signal 56b to the analog switch 49 to turn off the switch and open the tracking servo loop, and at the same time A control signal 56b is sent to the circuit 54. Then, the timing circuit 54 sends a timing signal 57d at L level (initialization) to the gain switching circuit 48, and the gain changes from the H level to the L level.
becomes normal level.

Also, although the tracking control system has been explained, the gain switching circuit 50 and analog switch 5 of the focus control system
1 also performs the same operation as the tracking control system.

Next, a specific example of the timing circuit 54 is shown in FIG.

In the configuration of this timing circuit, first, the output terminal of the inverter 58 to which the control signal 56 is input is connected to one input terminal of the AND gate 59. The inverter 60 to which the coincidence signal 55 is input has its output terminal connected to the input terminal of a D flip-flop circuit 61. Furthermore, the output terminal of the D flip-flop circuit 61 is connected to the other input terminal of the AND gate 59. The output terminal of the AND gate 59 is connected to a gain switching circuit 48°50.
(not shown) and sends out a timing signal 57.

Therefore, the operation of the timing circuit begins with the control signal 56.
A control signal inverted by an inverter 58 is input to an AND gate 59. Similarly, the coincidence signal inverted by the inverter 60 is manually input to the D flip-flop circuit 61, and the signal output as a torge is output to the AND gate 5.
9, an AND gate 59 performs a logical product and sends a timing signal 57 to a gain switching circuit 48, 50 (not shown) to switch the gain.

The optical information recording/reproducing device having the above configuration sets the gain high when starting and stopping the reciprocating movement of the optical card, thereby preventing malfunctions due to vibrations generated during starting and stopping or vibrations from external disturbances. At constant speed, that is, when recording and reproducing data, the gain can be set to the normal state (low) to eliminate malfunctions due to dirt or scratches on the recording surface of the optical card, and to maintain the optimal state. .

Furthermore, transient overcurrent can also be cut off by a driving means that stops servo driving when a track servo abnormality or a focus servo abnormality is detected on the input side of the driving circuit for driving the objective lens.

In this embodiment, the gain setting value is set to one predetermined high level with respect to the normal level, but the gain setting value is not limited to this and may be set to a plurality of levels.

Further, the present invention is not limited to the above-mentioned embodiment, and may be applied to other card-shaped record carriers.

It is also suitable for optical recording or reproducing by repeatedly driving at a constant speed and repeatedly stopping, and it goes without saying that various modifications and applications are possible without departing from the gist of the invention.

(Effects of the Invention) As described in detail above, according to the present invention, there is no malfunction due to transient vibrations generated due to reciprocating movement of a card-shaped optical information recording carrier, and there is no possibility of malfunction during data recording. During playback, the optimum gain is set, and focus control and tracking control can be performed without malfunctioning due to dust, dirt, etc. on the recording surface.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of an optical information recording/reproducing apparatus according to an embodiment of the present invention, FIG. 2 is a timing chart showing a gain switching operation of the optical information recording/reproducing apparatus of FIG. 1, and FIG. 3 is a circuit diagram showing the configuration of a specific example of the timing circuit shown in FIG. 2, FIG. 4 is a diagram showing the structure of an example of a conventional optical card, and FIG. 5 is a part of the optical card shown in FIG. 4. FIG. 6 is a block diagram showing the configuration of an optical information recording/reproducing device for recording and reproducing data on a conventional disk, etc., and FIG. 7a is a conventional drive for reciprocating an optical card. FIG. 7 is a front view showing the structure of the device, and FIG. 7 is a side view showing the structure of the drive device of FIG. 7a. DESCRIPTION OF SYMBOLS 1... Optical card, 9... Optical pickup, 14-path objective lens, 16... Optical pressure detector, 17... Demodulation circuit,
Objective lens, 16... Prior voltage detector, 17... Demodulation circuit, 18b... Clock signal, 19... Tracking error signal pressure detection circuit, 20... Tracking error signal, 21... Gain control Circuit, 22... control circuit,
30... Drive circuit, 31... Tracking coil,
44... Card motor drive system 44.45... Seek motor drive system, 46... Control circuit, 47... Card drive signal, 48; 50... Gain switching circuit, 49°51... Analog switch, 52... Counter, 5
3... Comparison circuit, 54... Timing circuit.

Claims (1)

[Claims] A light beam is irradiated onto a card-shaped optical information recording carrier in which a plurality of tracks are formed parallel to each other and is driven back and forth relative to the card-shaped optical information recording carrier. an optical pickup and means for detecting response light from the card-shaped optical information recording carrier in order to optically record/reproduce information; and a reproduction signal of the information based on a detection signal detected by the optical pickup means. demodulating means for demodulating and a synchronization signal; focus error signal generating means for generating a focus error signal based on the detection signal detected by the optical pickup means; and focus error signal generation means for generating a focus error signal based on the detection signal detected by the optical pickup means. tracking error signal generation means for generating a tracking error signal; focus servo means for controlling a light beam irradiated on the optical information recording carrier to a focused state based on the focus error signal; tracking servo means for controlling an irradiated light beam to a track following state based on the tracking error signal; a counting means for counting synchronization signals demodulated by the demodulation means; and a count number of the synchronization signals of the counting means and the a comparison means for outputting a coincidence signal when a preset reference value corresponding to a predetermined position of the card-shaped optical information recording carrier matches; and a focus servo system and a focus servo system in response to the coincidence signal from the comparison means. 1. An optical information recording/reproducing apparatus comprising: gain changing means for changing the gain of at least one of the tracking servo systems to be higher than a normal gain.