JPH03147525A - Optical card device - Google Patents

Abstract

PURPOSE:To stably perform the recording/reproduction of information by detecting the average speed of the relative movement of an optical card with an optical head in a prescribed area, and controlling the relative movement of the optical card with the optical head so as to obtain coincidence between the average speed and targeted speed in the area based on the comparison of the average speed with the targeted speed set in advance. CONSTITUTION:The averaged speed of the relative movement of the optical card with the optical head in the prescribed area is detected. And detected average speed is compared with the targeted speed set in advance. Then, the relative movement of the optical card with the optical head is controlled based on comparison output so as to obtain the coincidence between the average speed and the targeted speed in the prescribed area. In other words, the speed of a shuttle is corrected and is conformed to the targeted speed without being affected by offset or drift, etc., by detecting deviation between the average speed of the shuttle detected at a speed detection circuit 41 and the targeted speed set in advance with a controller, and outputting a speed correction signal to a D/A converter 42. Thereby, it is possible to stably perform the recording/ reproduction of the information.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an optical card device that records and/or reproduces information using an optical card.

[Conventional technology]

Optical cards have a storage capacity several thousand to ten thousand times larger than magnetic cards, and like optical disks, they cannot be rewritten, but because of their large storage capacity of 1 to 2 MB, they are often used for bank passbooks, etc. A wide range of applications are being considered, such as portable maps or prepaid cards used for shopping.

Various types of such optical cards have been proposed in the past, and the applicant has also proposed one as shown in FIG. 2 in Japanese Patent Laid-Open No. 63-37876.

The optical card 11 shown in FIG. 2 has an ID section 14 in which information indicating an address corresponding to each track is recorded at both ends of an optical recording section 13 having a plurality of tracks 12 parallel to each other so as to be read from opposite directions. ^.

14B, and a data section 15 is defined between these 10 sections 14A and 14B. Therefore, for example, when the optical card 11 is moving from left to right in the track direction with respect to the optical head (hereinafter referred to as forward direction), the 10 parts 14 on the left side
When the optical card 11 is moving from right to left with respect to the optical head (hereinafter referred to as the reverse direction), A is 10 parts 1 on the right side.
By reading 4B, track address information corresponding to the track can be recognized. Note that the 10 parts 14A and 14B are placed at a certain distance (for example, 4mm) provided on the inside.

FIG. 3 shows the overall configuration of a conventional optical card device using the optical card 11 described above, in which the optical card 11 is moved in the track direction and the optical head 21 is moved in a direction perpendicular to the track to record/record data. It performs regeneration. The optical card 11 is loaded onto a shuttle 24 provided at a predetermined position on a conveyor belt 23 that is passed between pulleys 22A and 22B, and is transported back and forth in the track direction by driving a motor 26 by a motor servo circuit 25. ing.

A rotary encoder 27 for detecting the position of the shuttle 24 with respect to the optical head 21 is attached to the motor 26, and the rotary encoder 27 outputs a pulse every time the shuttle 24 moves by 50 μm, for example. ing. The output of this rotary encoder 27 is supplied to the motor servo circuit 25, and the 10 parts 14A, 14 of the optical card 11 are controlled based on the position information.
The controller 28 controls the transport speed to be constant between B and B.
A control command is sent from the motor servo circuit 25 to the motor servo circuit 25.

FIG. 4 shows the circuit configuration of the motor servo circuit 25. A drive signal and a drive direction signal are supplied from the controller 28 to the ROM 25^, and the motor 26 is switched between position control and speed control by the drive signal from the controller 28. The addresses of this ROM 25A correspond to positions of the shuttle 24 every 50 μm, and when the drive signal is not active, data for positioning with addresses corresponding to the positions of both ends of the optical card 11 is output, and the drive When the signal is active, data for forward drive or reverse drive is output in accordance with the drive direction signal. That is, when the drive direction signal is set to the forward level and the drive signal is activated, the drive data (speed target value) of each address is transferred from the ROM 25A to the D/A converter 25B and the power amplifier 2.
The signal is applied to the motor 26 via 5G, thereby transporting the shuttle 24 in the forward direction.

The A-phase and B-phase outputs of the rotary encoder 27 coaxial with the motor 26 are input to a direction discriminator 25D, and an output signal indicating the transport direction of the shuttle 24 from the direction discriminator 25D causes the optical radar 21 to The value of the up/down counter 25H indicating the position of the shuttle 24 is updated, and the difference between the target value and the D/A converter 25B is calculated via the F/V converter 25F. The speed is controlled so that it becomes zero.

The output data of the ROM 25^ changes from acceleration data to constant speed data when the shuttle 24 passes the acceleration region (the left end of the ID section 14A), and passes through the constant speed region (10 section 14A, data section 15 and 10 section 14B). The constant speed data becomes deceleration data. The controller 28 switches the drive signal from speed control to position control to stop transport of the shuttle 24 when the shuttle position signal output from the up/down counter 25E reaches a predetermined value. Note that when the level of the drive direction signal is inverted to make the drive signal active, the shuttle 24 is transported in the opposite direction.

In FIG. 3, an optical head 21 directs writing or reading light from a laser diode 21A to a prism 21.
The light is projected onto the optical card 11 through the prism 21B, and the reflected light is made to enter the detector 21C through the prism 21B. The output of the detector 21C is supplied to a demodulation circuit 29, where a read signal is obtained, and a focus/track servo circuit 30
A focus error signal and a tracking error signal are detected, and the optical head 21 is driven in the focusing and tracking directions to drive the optical card 1.
The incident light is controlled so that it always follows one track in a focused state.

Furthermore, when reproducing information, the controller 28 causes the laser diode 21A to output a low-power reading light via the laser drive circuit 31, and drives the motor servo circuit 25, demodulation circuit 29, and focus/track servo circuit 30. control, the track address information demodulated by the demodulation circuit 29 is used to seek to a desired track and read information, and when writing information, after seeking on the desired track to be written in the same manner as above, the laser The laser diode 21A modulates and outputs high-power writing light from the laser diode 21A via the drive circuit 31 according to the information to be recorded, thereby writing the information on the track.

[Problem to be solved by the invention]

However, in the above-mentioned optical card device, the D/
A: If there is offset or drift in the 17 park 25B or F/v converter 25F, the shuttle 24 in the ID sections 14A and 14B of the optical card 11 and the data section 15
Since the speed of the shuttle 24 greatly differs from the target speed, there is a problem that during playback, the pit interval read differs greatly from the design value of the device, making playback impossible.Also, during recording, especially when the speed of the shuttle 24 is If the speed is faster than the specified speed, a very serious problem may occur in which the ID section is written out.

This invention was made by focusing on these conventional problems, and it is possible to always match the relative speed between the optical card and the optical head with the target speed without being affected by offset, drift, etc. Therefore, it is an object of the present invention to provide an optical card device suitably configured to be able to stably record/reproduce information.

[Means and operations for solving the problem] In order to achieve the above object, the present invention provides an optical card device that records and/or reproduces information while relatively moving an optical card and an optical head. speed detection means for detecting the average speed of relative movement between the card and the optical head in a predetermined region; and comparison means for comparing the average speed detected by the speed detection means with a preset target speed;
Conveyance control means for controlling the relative movement of the optical card and the optical head so that the average speed in the predetermined area detected by the speed detection means matches the target speed based on the output of the comparison means. and

〔Example〕

FIG. 1 shows the configuration of a main part of an embodiment of the present invention. In this embodiment, a speed detection circuit 41, a D/A converter 42, and an analog switch 43 are added to the optical card device shown in FIG. The speed detection circuit 41 includes a counter 41A and an address decoder 41.
B, a clock generator 41C and an AND circuit 410. The output of the up/down counter 25B is supplied to the address decoder 41B, and when the output value of the up/down counter 25E is in the constant speed region (rD section 14A, data section 15, and ID section 14B), A high level signal is supplied to one input terminal of the AND circuit 410. AND circuit 4
A clock from a clock generator 41C is supplied to the other input terminal of 10, and the output of this AND circuit 410 is supplied to a clock terminal of a counter 41A. Make the clock count from . In addition, counter 4
A drive signal from the controller 28 is supplied to the clear terminal 1A so that the counter 41A is cleared when the shuttle 24 switches from position control to speed control.

In this manner, the speed detection circuit 41 measures the time (count value) during which the shuttle 24 passes through the constant speed region for each transport, and supplies the measured time to the controller 28 as a speed detection signal. Therefore, the shorter the output of the counter 41A, that is, the measurement time, the faster the average speed at which the shuttle 24 passes through the constant speed region;
4, the average speed at which it passes through the constant speed region is slow.

On the other hand, the controller 28 is set in advance as a target value for the passing time when the shuttle 24 passes through the constant speed region at a target speed, and the controller 28 uses the target value and the speed detection signal from the speed detection circuit 41 as the target value. Based on this, the deviation between the average speed of the shuttle 24 in the constant speed region and the target speed is detected. Here, if the speed detection signal (count value) is smaller than the target value, the average speed of the shuttle 24 in the constant speed region is faster than the target speed, and conversely, if the speed detection signal is larger than the target value, the shuttle 24's average speed is higher than the target speed. The average speed in the constant speed region is slower than the target speed. Based on this detected speed difference, the controller 28 instructs the shuttle 24 to speed up if the average speed is slow during the next transport in the same direction (for the forward direction speed difference, the next forward direction). A speed correction signal is sent to the motor servo circuit 2 via the D/A converter 42 and the analog switch 43.
5 servo loop. The analog switch 43 is configured to supply the output of the D/A converter 42 to the servo loop of the motor servo circuit 25 only when it is active, that is, during speed control, in response to a drive signal from the controller 28. Therefore, during speed control, D
/^Output of converter 25B and D/A converter 4
The difference between the summed output of the two outputs and the output of the F/V converter 25F is calculated, and the speed is controlled so that the difference becomes zero. Here, the increase/decrease in the output of the mouth/A converter 42 is:
Since this is the same as increasing or decreasing the output of the D/A converter 25B, which is the speed target value, it is possible to correct the speed of the shuttle 24 by increasing or decreasing the output of the 0/A converter 42. Note that the reason why the speed correction is performed only during speed control is to have no effect on position control.

In this way, the speed detection circuit 4 in the controller 28
The D/A converter 2
Even if the average speed differs greatly from the target speed due to offset or drift of the F/V converter 25F or the F/V converter 25F, the speed of the shuttle 24 can be corrected to match the target speed, making it possible to stably record/reproduce information. It can be carried out.

In the above-described embodiment, one speed detection circuit detects the average speed of the constant speed region, but a plurality of speed detection circuits are provided to divide the constant speed region and detect the average speed of each divided region. It is also possible to calculate the speed and control the speed for each divided area. In this way, more accurate correction can be performed. Further, in the embodiment described above, the rotary encoder 27
Although the position relative to is detected, this can also be done using a linear encoder. Further, in the above embodiment, the shuttle 24 is moved in the track direction, but the optical head 21 may also be moved in the track direction.

〔Effect of the invention〕

As described above, according to the present invention, the average speed of relative movement between the optical card and the optical head in a predetermined area is detected, and a predetermined speed is determined based on a comparison between the average speed and a predetermined target speed. The relative movement between the optical card and the optical head is controlled so that the average speed in the area matches the target speed, so information can be recorded/played stably without being affected by offsets, drifts, etc. can be done.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of essential parts of an embodiment of the present invention, and FIGS. 2, 3, and 4 are diagrams for explaining conventional techniques. 11... Optical card 12... Track 13
...Optical recording section 14A, 14B...10
Section 15...Data section 21...Optical hand 22^, 22B...Pulley 23...Transport belt 24...Shuttle 25...Motor servo circuit 26...Motor 27...Rotary encoder 28... Controller 29... Demodulation circuit 30
...Focus track servo circuit 31...Laser drive circuit 41...Speed detection circuit 41A...Counter 41B...Address decoder 41C.
... Clock generator 42 ... D/A converter 43
...Analog switch Figure 1 Figure 4

Claims (1)

[Claims] 1. In an optical card device that records and/or reproduces information while relatively moving an optical card and an optical head, detecting the average speed of relative movement between the optical card and the optical head in a predetermined area. a speed detection means for comparing the average speed detected by the speed detection means with a preset target speed, and a predetermined area detected by the speed detection means based on the output of the comparison means. an optical card device comprising: a transport control means for controlling relative movement between the optical card and the optical head so that an average speed at the optical head matches the target speed.