JP2698421B2 - Optical card device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical card device for recording and / or reproducing information using an optical card.

[Prior art] An optical card has a storage capacity of several thousand times to 10,000 times that of a magnetic card and cannot be rewritten like an optical disk, but the storage capacity is as large as 1 to 2 Mbytes. A wide application range is considered as a prepaid card used for a bank passbook for use, a map for portable use, shopping, and the like.

Various types of such optical cards have heretofore been proposed, and the present applicant has disclosed it in Japanese Patent Application Laid-Open No. 63-37876.

The optical card 7 shown in FIG. 9 has an ID section 14A in which information indicating an address corresponding to each track is recorded on both ends of an optical recording section 17 having a plurality of tracks 16 parallel to each other so as to be readable from opposite directions. , 14B, and these ID sections 14
The data section 15 is defined between A and 14B. Therefore, for example, when the optical card 7 is moving from left to right in the track direction with respect to the optical head (hereinafter referred to as the forward direction), the optical card 7 is moved from right to left with respect to the optical head. When moving to (the reverse direction), the ID on the right
By reading the section 14B, the track address information corresponding to the track is recognized. Note that the ID portions 14A and 14B are provided at a fixed distance from the end of the card in order to prevent the effects of scratches and dirt on the end of the card and to sufficiently stabilize the relative moving speed of the optical card 7 and the optical head in the track direction. (For example,
4mm) Provided inside.

FIG. 10 shows the overall configuration of a conventional recording / reproducing apparatus using the above-mentioned optical card 7, in which the optical card 7 is moved in the track direction and the optical head 18 is moved in the direction perpendicular to the track to record data. / Reproduction. The optical card 7 is loaded on a shuttle 19 and is reciprocated in the track direction by driving a motor 20. A rotary encoder 21 for detecting the position of the shuttle 19 with respect to the optical head 18 is attached. According to the position information from the rotary encoder 21, the optical card 7
A control command is sent from the controller 22 to the motor servo circuit 23 so that the transport speed is constant between the ID units 14A and 14B.

FIG. 11 shows a circuit configuration of the motor servo circuit 23. When a drive direction signal (a signal indicating a forward direction or a reverse direction) and a drive signal control command are input from the controller 22, the ROM address is determined. I do. Driving data (speed target value) of each address is given to the motor 20, whereby the shuttle 19 is conveyed. The output of the rotary encoder 21 is input to the direction discriminator, and the output signal from the direction discriminator updates the value of the up / down counter indicating the position of the shuttle 19 with respect to the optical head 18, and The difference from the target value is obtained via the F / V converter, and the speed is controlled so that the difference becomes zero.

[Problems to be solved by the invention]

However, in the conventional recording / reproducing apparatus, if the shuttle runs away for some reason, there is a problem that the runaway leads to damage of the peripheral mechanism, and thus the use of the optical card device becomes impossible. As a method of detecting such a runaway and stopping it, JP-B-56-10
As disclosed in Japanese Patent No. 644, an abnormal speed detection circuit,
There is a method that includes an abnormal drive current detection circuit and a drive current detection circuit, and short-circuits the input terminal of the motor so as to stop runaway when at least one of them is detected.
However, these detection circuits are specially provided only for detecting runaway, which leads to an increase in cost.

SUMMARY OF THE INVENTION The present invention has been made in view of such a conventional problem. An optical card device which detects runaway and stops an optical card device without using special detecting means only for detecting runaway. It is an object to provide a card device.

[Means and actions for solving the problem]

In order to achieve the above object, the present invention controls the relative movement between the optical card and the optical head in an optical card device for recording and / or reproducing information by relatively moving the optical card and the optical head. Transport control means, focus detection means for detecting a focused state of the light beam on the optical card by the optical head, and transport control means when the focus detection means detects that the optical beam has deviated from the focused state. And a stop command means for outputting a stop signal.

In this way, the relative movement can be stopped via the conveyance control means for controlling the relative movement between the optical card and the optical head by the focus detection means.

〔Example〕

FIG. 1 shows a main part of an embodiment of the present invention, which is a circuit configuration of a motor servo circuit 2. As shown in FIG. 3, the driving direction signal from the controller 10 (forward direction,
When the control signal of the drive signal is input, the address of the ROM 2A is determined. The address of the ROM 2A corresponds to the position of the shuttle 8 at every 50 μm. Drive data (speed target value) of each address is D / A converter 2
The signal is supplied to the motor 3 via B and the power amplifier 2C, whereby the shuttle 8 is conveyed. The outputs of the A-phase and the B-phase of the rotary encoder 4 on the same axis as the motor 3 are input to the direction discriminator 2D, and an output signal indicating the transport direction of the shuttle from the direction discriminator 2D causes the shuttle 8 to the optical head. The value of the up / down counter 2E indicating the position is updated, and the difference from the target value is obtained via the F / V converter 2F, and the speed is controlled so that the difference becomes zero. It has become.

The output data of the ROM 2A changes from acceleration data to constant speed data when the shuttle 8 passes through the acceleration area, that is, when the value of the up / down counter 2E exceeds the distance value of the acceleration area, and decelerates from constant speed data when the shuttle 8 enters the deceleration area. When the value of the up / down counter 2E reaches a predetermined value after the data, the zero speed data is output to stop the transport of the shuttle 8. In order to transport the shuttle 8 in the opposite direction, the level of the driving direction signal may be inverted and a driving signal may be given.

Next, the runaway stop circuit 1 short-circuits the input terminal of the motor so as to stop the motor when the controller 10 outputs the runaway stop signal.

FIG. 2 is an example of the runaway stop circuit 1. Runaway stop circuit 1 has a relay 1A and a relay drive circuit 1B that are linked in two circuits. When the runaway stop signal is not output from the controller 10, the relay drive coil 1Ag is driven by the output of the relay drive circuit 1B to connect the contacts 1Aa and 1Ac and the contacts 1Ad and 1Af to supply the output of the power amplifier 2C to the motor 3. . Relay drive circuit when runaway stop signal is output from controller
1B drives the relay drive coil 1Ag in the opposite direction to
Ab and 1Ac and contacts 1Ae and 1Af are connected, so power amplifier 2C
Is not supplied to the motor 3, the input terminal of the motor 3 is short-circuited, and the shuttle 8 can be stopped immediately.

Next, a method of detecting runaway of the shuttle 8 will be described. During normal operation, the shuttle 8 is reciprocated so that the light beam does not come off the optical card 7. In other words, when the transport is controlled normally, the focus / track servo circuit 12 controls the optical beam to always follow the track of the optical card 7 in a focused state. Always obtained.

Here, if the shuttle 8 runs out of control for some reason, the light beam deviates from the optical card 7, so that no focus error signal is obtained and no focus detection signal is obtained. That is, the runaway of the shuttle 8 can be detected when the focus detection signal is not obtained after the focus servo is turned on.

Therefore, when the focus detection signal cannot be obtained after turning on the focus servo, the controller 10 detects that the shuttle 8 has runaway and outputs a runaway stop signal to the runaway stop circuit 1 to promptly operate the shuttle 8. Can be stopped.

After the runaway is stopped, the controller 10 resets the abnormal control mode to return the shuttle 8 to the predetermined reference position, that is, the home position.

In some cases, the focus error signal may not be obtained even if dust or the like is present on the optical card. However, if the focus servo comes off, the optical card must be stopped and the focus servo drawn in again. Therefore, there is no problem caused by returning the shuttle 8 to the home position.

FIG. 3 shows the overall configuration of an optical card device using the above-described optical card 7. The optical card 7 is moved in the track direction and the optical head 9 is moved in the direction perpendicular to the track to record / reproduce data. Do. Optical card 7 is pulley 5a, 5
The transport belt 6 is loaded on a shuttle 8 provided at a predetermined position of the transport belt 6 and is reciprocated in the track direction by driving the motor 3 by the motor servo circuit 2. The motor 3 includes an optical head 9 of the shuttle 8.
Rotary encoder 4 for detecting the position with respect to
Is attached. One pulse of the rotary encoder 4 is, for example, 50 pulses of the shuttle 8 with respect to the optical head 9.
It corresponds to the position of μm. According to the position information from the rotary encoder 4, the ID part of the optical card is
A control command is sent from the controller 10 to the motor servo circuit 2 so that the transport speed is constant between 14A and 14B. Here, the optical system of the optical head 9 is a so-called “off-axis method”.

The light beam emitted from the laser diode 9a is converted into a parallel beam by a collimator lens 9b, and then split into three beams by a diffraction grating 9c, and is incident on a position shifted from the center axis C of the objective lens 9d. The three beams focused by the objective lens 9d form three fine beams on the signal surface of the optical card 7 as shown in FIG. These three beams are arranged in a row along the longitudinal direction while slightly intersecting the guide track 14a, with the main beam 15 having the main optical axis disposed in the center, and the sub-beams 16a and 16b having the sub-optical axes disposed on both sides. Are focused on the optical card surface in a line. Optical card 7
The reflected beam from passes through the objective lens 9d again, and
The direction of the beam is changed by 90 degrees by 9e, and an image is formed on the photodetector 9g by the imaging lens 9f.

FIG. 5 is an enlarged view of the photodetector 9g. The photodetector 9g is provided with photodetectors 9g-1 and 9g-2 for detecting a focus error signal composed of two divided elements at the center. This photo detector
On both sides of 9g-1 and 9g-2, photodetectors 9g-3 and 9g-4 for detecting a tracking error signal are provided. The main beam which is the reflected light of the center main beam 15 among the three reflected beams
15-1 is irradiated on the photodetectors 9g-1 and 9g-2, and the sub-beams 16a-1 and 16-b are reflected light of the sub-beams 16a and 16b on both sides.
b-1 is irradiated to the photodetectors 9g-3 and 9g-4, respectively.

Here, the relationship between the incident light of the main beam on the optical card 7, the reflected light, and the photodetector 9g is as shown in FIG. When the surface of the optical card 7 is in the in-focus state X, two photo detectors 9g
The difference between the outputs of -1, 9g-2 is zero. On the other hand optical card 7
Is displaced to the position Y, the output of the photodetector 9g-1 is 9g-2.
When the optical card 11 is displaced to the position Z, the output of the photodetector 9g-1 is larger than the output of 9g-2. The optical card 7 based on the above calculation
And the amount of displacement can be detected. When the distance between the optical card 7 and the objective lens 9d approaches or goes away, the main beam 15-1 is turned on by the arrow F on the photodetector 9g in FIG.
Displace in the direction. Here, the main beam 15-1 at the time of focusing
Is adjusted so that the center of is located at the boundary between the photodetectors 9g-1 and 9g-2, and the focus error signal is detected by detecting the difference between the output values of the photodetectors 9g-1 and 9g-2. Obtainable. On the other hand, the tracking error signal is
It is determined from the output difference between 9g-3 and 9g-4. By driving the objective lens 9d such that the output difference is always zero, the main beam can always follow the information track.

FIG. 7 shows a change in each signal. FIG. 7A shows a focus error signal based on the displacement of the optical card 7 and the objective lens 9d in the optical axis direction. Detection that a certain objective lens 9d is near the focal point is performed by:
It detects that the output sum signal of the photodetectors 9g-1 and 9g-2 (FIG. 7B) has exceeded a predetermined reference signal level and outputs a focus detection signal (FIG. 7C).

FIG. 8 shows the configuration of the focus / track servo circuit 12. The tracking servo obtains the output difference between the photodetectors 9g-3 and 9g-4 by the computing unit 12a and drives the objective lens 9d in the tracking direction by the power amplifier 12b so that the difference becomes zero. On the other hand, the focus servo is
c, the output difference between the photodetectors 9g-1 and 9g-2 is obtained, and the objective lens 9 is set by the power amplifier 12d so that the difference becomes zero.
Drive d in the focus direction. As for the focus detection signal, the output sum of the photodetectors 9g-1 and 9g-2 is obtained by the arithmetic unit 12e, and the focus detection signal is outputted to the controller 10 when it becomes larger than the comparison level 12g by the comparator 12f. The controller 10 moves the objective lens 9d in the focus direction when pulling in the focus servo, and turns on the focus servo loop when this focus detection signal is obtained.

In FIG. 3, the output of the photodetector 9g is supplied to a demodulation circuit 11, where a read signal is obtained.
Further, as described above, the focus error signal and the tracking error signal are detected from the output of the photodetector 9g, whereby the objective lens 9d is driven in the focusing and tracking directions, so that the incident light is always focused on the track of the optical card 7. It is controlled to follow in the state. In reproducing data, the controller 10 outputs a low-output reading light beam from the laser diode 9a via the laser driving circuit 13, and drives the motor servo circuit 2, the demodulation circuit 11, and the focus / track servo circuit 12. And seeks data to a desired track based on the track address information demodulated by the demodulation circuit 11 to read data. In writing data, after seeking on a desired track to be written in the same manner as described above, a high-power write light beam is modulated from the laser diode 9a through the laser drive circuit 13 by data to be recorded. The data is output and written to the track.

It should be noted that the present invention is not limited to the above-described embodiment, and various modifications or changes can be made. For example, in the above-described embodiment, the shuttle 8 is driven by the motor 3, but may be driven by a linear motor.
In the above-described embodiment, the position with respect to the optical head 9 is detected by the rotary encoder 4.
This can be done using a linear encoder.

In the above-described embodiment, the shuttle 8 is moved in the track direction. However, the optical head 9 may be moved in the track direction.

〔The invention's effect〕

As described above, according to the present invention, when the light beam from the optical head is out of focus on the optical card, the relative movement between the optical card and the optical head is stopped. The runaway can be quickly detected and stopped without using any special detecting means. Therefore, it is possible to safely record and reproduce information without causing damage to the mechanism due to runaway of the shuttle.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a main part according to an embodiment of the present invention, FIG. 2 is a circuit diagram of the main part, FIG. 3 is a schematic diagram showing the whole, FIG. FIG. 9 is an embodiment diagram of an optical card, and FIGS. 10 and 11 are an overall schematic diagram and a main block diagram showing a conventional example. 1 ... runaway stop circuit 2 ... motor servo circuit 3 ... motor 4 ... rotary encoder

Claims (1)

(57) [Claims] 1. An optical card device for recording and / or reproducing information by relatively moving an optical card and an optical head, comprising: transport control means for controlling the relative movement between the optical card and the optical head; Focus detection means for detecting the focus state of the light beam on the optical card by the optical head, and outputting a stop signal to the transport control means when the focus detection means detects that the focus state has deviated from the focus state. An optical card device provided with a stop command means for performing a stop command.