JPS61283032A - Optical information recording and reproducing device - Google Patents

Abstract

PURPOSE:To prevent an error signal in an inoperable state from being written and to record and reproduce exactly signal without fail by saving a scanning light beam to an area out of a recording area on a recording medium other than at recording or reproducing. CONSTITUTION:When the titled device executes recording and reproducing, a motor 21 and a stepping motor 28 are driven by the control of a CPU 27, and the light beam leaves its home position 6 and scans in the recording area. At this time, the light beam 32 from a semiconductor laser 11 has always a power of PWL or PR on an optical card, and modulation is carried out between the power PWH at recording in accordance with a recording signal inputted from a terminal C1. At reproducing a reproduction signal is outputted from a terminal C2. When the action ends, the motor 21 stops, and the light beam stops in a track selecting area as it has the power PWL or PR. Continuously the stepping motor 28 is driven according to the control of the CPU 27 to shift an optical head 16 in the direction of an arrow (d), and the light beam 32 is saved from the recording area 2 on the optical card 1 and is waited in a still state at the home position 6.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to an optical information recording and reproducing device, and particularly relates to a device used for a card-shaped optical information recording medium. It refers to a device that records information on a medium, a device that reproduces information recorded on a medium, and a device that performs both recording and reproduction.

[Prior art]

Conventionally, information has been recorded using light, and the recorded information has been read out in the form of a disk.

Various types such as card-shaped, tape-shaped, etc. are known. Among these, card-shaped optical information recording media (hereinafter referred to as optical cards) are expected to be in great demand as mediums with large storage capacities that are small, lightweight, and convenient to carry.

The above-mentioned optical card generates an optically detectable recording pit array by scanning a recording track within a preset recording area on the card with a light beam that is modulated according to recording information and focused on a minute spot. Information is recorded. At this time, in order to accurately record information without causing problems such as crossing of recording bit strings, it is necessary to control the irradiation position of the light beam in a direction perpendicular to the scanning direction (auto tracking, hereinafter referred to as AT). ) was necessary. Also,
Focus control (
Autofocusing (hereinafter referred to as AF) was also performed. Therefore, in order to obtain a tracking signal and a focusing signal from the recording track, the modulated light beam was set to have a predetermined power that would not cause writing on the card even at the minimum level. . In addition, when reproducing recorded information, the above-mentioned recorded pit array is scanned with a light beam having a constant power at a level that does not allow information to be written on the optical card.

On the other hand, the information reproducing means of the optical card as described above performs scanning of the light beam by relatively moving the optical card and the light beam during recording or reproducing operations. Furthermore, since the recording tracks on the optical card are provided in a plurality of straight lines, the above-mentioned scanning is performed intermittently, and the light beam is kept stationary during non-operation.

However, in such conventional devices, if the light beam remains stationary for a long time, erroneous signals may be written due to the accumulation of energy even with the light beam at a level that does not allow writing as described above. there were.

Such false signals are still detected by the light beam,
This caused a major problem when accessing trucks.

[Summary of the invention]

It is an object of the present invention to provide an optical information recording/reproducing apparatus which solves the drawbacks of the conventional apparatus, prevents writing of erroneous signals by a light beam during non-operation, and is capable of always performing accurate recording or reproducing operations. It is in.

The above object of the present invention is achieved by evacuating a light beam outside the recording area on the recording medium in an optical information recording/reproducing device when recording or reproducing is not in progress.

〔Example〕

Hereinafter, the present invention will be explained in detail using the drawings.

FIG. 2 is a schematic plan view showing an example of the position of an optical card used in the device of the present invention. In FIG. It is provided. In this recording area, a recording layer is formed in which information is recorded by unevenness or changes in reflectance by irradiation with a light beam. Further, reference numeral 3 indicates a plurality of recording tracks formed in a straight line in the recording area 2. Reference numeral 4 indicates a data area of the recording area where the light beam is scanned at a predetermined speed, and 5 indicates a track of the recording area where a desired track is searched. The selection area 6 is a home position provided outside the recording area. The light beam is initially stationary at home position 6. During recording or reproduction, the light beam first moves the track selection area 5 a.
Navigate in the direction and find the track you want to record or play. Then, the light beam is transmitted to the data area 4 of the truck.
The light beam is scanned in the direction of the arrow to perform recording or reproduction. When recording or reproduction is completed, the light beam moves to the track selection area 5.
Stop within. By repeating this operation, a predetermined amount of data is recorded or reproduced.

FIG. 3 is a diagram illustrating the power of a light beam on an optical card during recording and reproduction, where (A) is the power during recording and CB) is the power during reproduction. In addition, the horizontal axis of the figure shows the position on the track, and the vertical axis shows the optical power P. During recording, the light beam is transmitted in the scanning range Ew corresponding to the data area as shown in (A).
Minimum power PI required to prevent recording pits from being formed and to obtain tracking and focusing signals.
The optical card is always illuminated with IL. Then, according to the recording signal, the power PWH is modulated as much as necessary for recording, and recording pits are formed only in the portions irradiated with the power PjlH. Also, during reproduction, a light beam is irradiated with a constant power PR at which no recorded pits are formed in the scanning range ER, and the aforementioned recorded pits are read.

Here, the recording sensitivity S of the normal optical card is determined by the irradiation power P and irradiation time T of the light beam.

Therefore, when the spot of the light beam is scanned from 72 to 71 at a relative velocity V as shown in Fig. 4, if the spot diameter is Φ, if ■ is greater than Φ/T, it will not be recorded.However, as mentioned above, If the light beam is waiting in a stationary state, if this state continues for a long time, even if the optical power is <Pwt or PR as described above, it will be recorded incorrectly.
In order to prevent such erroneous recording, the present invention evacuates the irradiation position of the light beam on the optical card outside the recording area except when recording or reproducing is being performed.

FIG. 1 is a schematic diagram showing an embodiment of optical information recording and reproduction based on the present invention. Here, l is an optical card as shown in FIG. 2, and is placed on a storage stand 17 fixed to a belt 20. The belt 24 is passed around the pulleys 19 and 1B, and is moved in the direction of arrow C by the motor 21, and the optical card 1 is also moved in the C direction accordingly. Therefore, on the optical card, the light beam 32 irradiated from the optical head 16 is scanned in the direction b in FIG. 2. The optical head 16 includes a semiconductor laser 11. Collimator lens 12. Beam splitter 13. It is composed of an objective lens 14 and a photodetector 15. The light beam 32 is emitted from the semiconductor laser 11 and is focused onto the optical card 1 by the objective lens 14 as a minute spot. Further, the light beam 32 reflected by the optical card passes through the objective lens 14 again, is separated from the incident light by the -beam splitter 13, and is detected by the photodetector 15. The signal detected by this photodetector 15 is transmitted to the signal demodulation circuit 22. Tracking control circuit 23. The signal is sent to the focus control circuit 24, and the focus control circuit 24 and tracking control circuit 23 move the objective lens 14 in the optical axis direction and in the direction perpendicular to the optical axis, respectively, and perform AF and AT.

Reference numeral 28 denotes a stepping motor that moves the optical head 16 in a direction perpendicular to the plane of the paper, thereby moving the irradiation position of the light beam in the direction a in FIG. 2 for track access (seek operation).
The motor 21 is controlled by a motor drive circuit 25 to move and stop the optical card.
Signal demodulation circuit 22. Stepping motor 28. Motor drive circuit 25. The laser drive circuits 31 are each connected to a central processing unit (CPU) 27 via an interface z6.

In this device, when performing a recording or reproducing operation, the motor 21 and the stepping motor 28 are driven under the control of the CPU 27, and the light beam leaves the home position 6 and enters the recording area as explained in FIG. scan. At this time, the light beam 32 from the semiconductor laser 11
always has the power of FIG. 3 PIIL or PR on the optical card.

During recording, further modulation is performed between the power PjlH and the recording signal input from the terminal CI. Furthermore, during reproduction, a reproduction signal is output from terminal C2. When the operation is completed, the motor 21 stops.

The light beam stops within the track selection area while having power PWL or pa+. Subsequently, the stepping motor 28 is driven under the control of the CPU 27 to move the optical head 16 in the direction of arrow d as shown in FIG.
is evacuated from the recording area 2 on the optical card l and made to stand by in a stationary state within the home position 6. When starting the operation again, the above-described operation is repeated, and the light beam 32 moves from the home position 6 to the recording area 2 to perform recording or reproduction.

In the above example, the light beam is evacuated to the home position except when recording or reproducing, but it may be configured to be evacuated to another position as long as it is outside the recording area. When the light beam is outside the recording area, it is possible to temporarily stop oscillation of the semiconductor laser and wait, but in this case, if you want to start oscillating again, it is desirable to do it outside the recording area. It is possible to prevent erroneous recording in the recording area due to overshoot of the laser beam intensity at the start or stop of laser oscillation, which occurs rarely.

〔Effect of the invention〕

As explained above, the optical information recording/reproducing apparatus of the present invention is designed to evacuate the light beam from the recording area except when recording or reproducing, so that it may be possible to accidentally record data in the standby state of operation. This has the effect of preventing malfunctions such as when searching for a track.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram showing an embodiment of the optical information recording/reproducing device of the present invention, FIG. 2 is a schematic plan view showing an example of an optical card used in the device of the present invention, FIG. 3(A), (B) is a diagram explaining the optical power on the optical card during recording and reproduction, respectively, FIG. 4 is a schematic diagram showing how the spot of the light beam is scanned on the optical card, and FIG. FIG. 3 is a schematic perspective view illustrating the movement of the optical head after reproduction is completed. 1-m-optical card, 2-m-recording area, 3-m-
Recording track, 4m-data area, 5--) rack selection area, 6-- home position.

Claims (1)

[Claims] (1) Other than when recording or reproducing information in an optical information recording/reproducing device that scans a recording area provided in a part of a card-shaped optical information recording medium with a light beam to record or reproduce information. An optical information recording/reproducing apparatus characterized in that the light beam is evacuated outside a recording area on the recording medium.