JPS61253653A - Optical memory card - Google Patents

Abstract

PURPOSE:To obtain an optical memory card having a high recording density for executing stably recording and reproducing operations by providing a guide groove for designating a recording place of information, and a guidance use guide groove extending to an initializing position, so that a recording/ reproducing head is guided to the initializing position. CONSTITUTION:An optical head is set onto a guide groove 21 for guiding a card, and a focal control and a tracking control are applied. The head is moved in parallel to the guide groove 21, and led to a guide groove 22 of an initializing position. Subsequently, the head is moved in the direction parallel to a guide groove 23 in order to enter into the guide groove 23 for recording and reproducing prescribed information, and when it reaches a branch point, a signal is applied so that the head moves a little in the direction vertical to the guide groove 23, so that it goes into the prescribed guide groove 23 in accordance with a sequence which has been stored in advance in a device. By repeating this operation whenever the head reaches the branch point, the head is led into the prescribed guide groove 23, and a state that information can be recorded and reproduced is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an optical memory card that records and reproduces information using a light beam.

<Prior Art> Conventionally, as this type of optical memory card, there is one called Lamer Card J (trade name), for example. For more information on this, see e.g. Proc
eedings of 5PIE Vol, 329 p.
.

61-p., 68. The structure of this conventional optical memory card is shown in FIG.

In the figure, 11 is a transparent substrate, 12 is a recording thin film, 13 is a heat insulating layer for improving the recording sensitivity of the recording thin film 12, and 1
4 is a protective layer for the recording thin film 12 and the heat insulating layer 13, 15 is a laser beam for recording and reproducing, and 16 is a recorded pit.The method of recording and reproducing in this conventional optical memory card will be described below. First, information recording line transparent substrate 11
This is carried out by irradiating the recording thin film 12 with laser light 15t converged through the recording thin film 12 and melting and vaporizing the recording thin film 12. At this time, the rows of pits 16 are formed by blinking the laser beam 15 while moving the optical system including the objective lens.

To form a row of adjacent pits 16, the optical system is moved by the distance between the bit rows, and then the same operation is repeated. On the other hand, to reproduce the recorded information, the output of the laser beam 15 is weakened to an extent that the recording thin film 12 is not melted, and the bit 16 is
This is done by reading the change in the amount of reflected light along the pit row.

<Problems to be Solved by the Invention> In the reproduction of this conventional optical recording card, the positioning of the optical system to the bit string is performed by moving the optical system to the same position as during recording. The irradiation position of the light beam of the Shireda light 15 may deviate from the recorded bit 16 due to deviation from the set position of the optical system for inserting and removing the memory card, and the signal may not be reproduced, or the signal of an adjacent bit string may be detected. Considering that the bits 16 may be damaged, the size of the bits 16 and the interval between the bits 16 cannot be made too small. In other words, the size of bit 16 is 104m, and the interval between pit rows is 50μ.
The lower limit is about m, and the current recording density is about 5 x 106 bits for a card the size of a business card.

SUMMARY OF THE INVENTION In view of the above drawbacks of the prior art, it is an object of the present invention to provide an optical memory card that allows stable recording and reproducing operations and has a high recording density.

<Means for Solving the Problems> The configuration of the present invention that achieves the above object is to provide a guide groove for specifying a recording location of information, and record/reproduce information along the guide groove. Furthermore, by providing a guide groove for guiding the recording/reproducing head to the initial setting position, the recording/reproducing head is easily guided to the initial setting position.

Example of implementation Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

FIG. 1 shows a first embodiment of the present invention, and FIG. 2 shows an enlarged cross-sectional structure thereof. In both figures, 21 is a guide groove for guiding to the initial setting position, 22 is a guide groove for the initial setting position, 23 is a guide groove for the information recording part, 24 is a transparent substrate, 25
2 is a recording thin film, 26 is a heat insulating layer for improving the sensitivity of the recording thin film 25, and 27 is a protective layer for the recording thin film 25 and the heat insulating layer 26.

In addition, in the drawing, for the sake of simplicity, the number of guide grooves 21 for guidance is 5.
However, it was confirmed that the more guide grooves 21 there are, the more stable the tracking operation can be, and that tracking is possible if ten guide grooves 21 are formed at a pitch of 5 μm. In addition, the guide groove 23 for information recording is shown in the drawing.
For simplicity, we set 16 branches, but if we provide n stages of branches, we will have 2 branches.
If m guide grooves 23 can be formed and the pitch is 1.6 μm, more than 30,000 guide grooves can be formed on a card the size of a business card.

Next, a method for manufacturing an optical memory card of the present invention will be described below. The method of manufacturing an optical memory card of the present invention is similar to the method of manufacturing a conventional optical disc. That is,
First, a photoresist groove is formed on the glass plate,
Prepare a groove master plate. More specifically, 7 Otoresist is applied to a predetermined thickness on a glass plate using a spin coat (K). Next, the glass plate Kll! The guide groove forming position of the coated photoresist is exposed with a focused laser beam. By developing this, guide grooves can be formed and a groove original plate is produced. Next, after depositing silver or nickel for electrodes on this grooved master plate, a stamper is produced by nickel electroforming. Next, using this stamper, the grooves are transferred onto a plastic material such as acrylic resin by a method such as injection molding or 2P (7-oto-polymer) method to obtain a transparent substrate 24 of an optical memory card.

Next, a recording thin film 25 made of Te or To compound, etc.
form. Finally, a heat insulating layer 26 made of a material with low light absorption and low thermal conductivity such as C81 and a protective layer 27 made of a plastic material such as acrylic photocurable resin are formed.

Next, a method for recording and reproducing information using the optical memory card of the present invention will be described. The method of recording and reproducing information on the optical memory card of the present invention is similar to the recording and reproducing method of conventional optical discs, and is based on focusing control and trunking control of an optical head using a semiconductor laser. Let's do it. In either case of recording session playback,
First, when an optical memory card is installed, the optical head is set on the guide groove 21 for guiding the card, and focus control and tracking control are applied. At this time,
Since the head is tracked by one of the guide grooves 21 for guidance, if the head is moved parallel to the guide groove 21, it will be guided to the guide groove 22 at the initial setting position. Next, K enters the guide groove 23 where predetermined information is recorded and reproduced.
Further, the head is moved in a direction parallel to the guide groove 23.

When the branch point is reached, a signal is applied so that the head moves slightly in a direction perpendicular to the guide groove 23 so that the head enters the predetermined guide groove 23 according to the nine sequences previously stored in the device. By repeating this operation every time a branch is reached, the spatula P is introduced into the predetermined guide groove 23,
It becomes possible to record and reproduce information. The above tracking operation is performed by weakening the output of the laser beam to such an extent that the recording thin film 25 does not melt and evaporate, as in the case of reproduction described later.
When recording, the head is moved along the guide groove 23 from the front according to the recording signal /'? Bits are formed on the recording thin film by increasing the output of the laser beam in a lasing pattern. In the case of reproduction, while moving the head along the guide groove 23, changes in the amount of reflected light due to the bits are read.

Next, specific examples of the present invention will be described. After coating a glass plate with a 700mm photoresist using a spin code, the guide grooves 21 and 2 with a width of 00-6a and a depth of 700A are formed by exposing and developing with focused argon laser light.
2°23 was formed. The number of guide grooves 21 for guiding to the initial setting position was 10 at a pitch of 5 μm.

Further, the guide grooves 23 for information recording were provided with 12 stages of branches, with 4096 lines at a pitch of 2.5 μm. Next, nickel was vacuum-deposited on this groove master plate, and a stun groove was produced by nickel electroforming. Next, by injection molding, the grooves were transferred to a polycarnate substrate to produce a business card-sized transparent substrate 24 measuring 90 cm x 55 m. Next, C8tφT was applied as the recording thin film 25 to the guide groove forming portion.

After forming a thin film to a thickness of 4oof by plasma polymerization, a C8 thin film was formed to a thickness of 2oooX by plasma polymerization as a heat insulating layer. Further, as a protective layer 27, an epoxy-based photocurable resin was formed to a thickness of 30 μm. When the optical memory card obtained in this way was attached to a recording/reproducing device using a semiconductor laser and a tracking experiment was attempted, it was found that the head was reliably guided to the initial setting position and that the guide groove for recording was properly guided. I confirmed that it was tracked on 23. It was also confirmed that the tracking operation was stable even when the optical memory card was inserted and removed, and that the predetermined guide groove 23 could be reliably detected. Next, when I tried to record a signal on the recording guide groove 23, the racer hower was 6mW1 pulse width 1 on the card.
A bit with a diameter of about 1 μm is formed at 00 n5ec,
We confirmed that 1.6XIO" bits of information can be recorded on the optical memory card of the present invention.Furthermore, when we tried recording and reproducing code information, we found that tracking operation and recording and reproducing along the track The operation was confirmed and a reproduction signal of good quality was obtained.

FIG. 3 is a diagram showing a second embodiment of the present invention. In the same figure, 41 is a guide groove for guiding to the initial setting position;
4 is a guide groove for the initial setting position, and 43 is a guide groove for recording information. The optical memory card of this embodiment is different from the first embodiment in that the guiding groove 41 is two meandering paths, but the cross-sectional structure and manufacturing method are the same as the first embodiment. be. The method of tracking the optical memory card of this embodiment will be described below. First, the optical memory card
When the optical disk is attached, the optical spatula P is set on the two guiding grooves 41, and focus control and tracking control are applied. Next, if the head is moved in a direction parallel to the recording guide groove 43, the tracking will be directed to either of the two guiding guide grooves 41, and the head will be guided to the guide groove 42 at the initial film constant position. . The reason why the guide groove 41 for guidance is a meandering path is to facilitate tracking by providing a component parallel to the guide groove 43 for recording. The method of tracking from the guide groove 42 at the initial setting position to the recording guide groove 43 and the recording/reproducing method are the same as in the first embodiment.

Next, specific examples will be described. An optical memory card was produced by the same method as in the first example.

However, the guiding grooves 41 are two meandering paths, and the interval between the two guiding grooves 41 at the end of the optical memory card is 10.
The amplitude and period of the 0 μm meandering were both 5 μm.

When the optical memo IJ-card thus obtained was subjected to a tracking experiment similar to that in the first embodiment, it was found that the head was reliably guided to the initial setting position and furthermore was tracked to the predetermined recording guide groove 43. I was sure that. In addition, the tracking operation is stable even when the optical memory card is inserted or removed, and it is ensured that the predetermined guide groove 43
It was confirmed that it could be detected. Next, when we tried the same recording and playback as in the first example, we confirmed the tracking operation and the recording and playback operation along the track, and
A reproduced signal of good quality was obtained.

<Effects of the Invention> As specifically explained above in conjunction with the embodiments, according to the optical memory card of the present invention, since information is recorded and reproduced along the guide groove, tracking operation is easy and high-density recording is possible. Not only is this possible, but the tracking operation can be performed stably and reliably since a guide groove is provided to guide the user to the initial setting position.

[Brief explanation of drawings]

FIG. 1 is a structural diagram of the first embodiment of the present invention, and FIG. 2 is a structural diagram of the first embodiment of the present invention.
FIG. 3 is a structural diagram of a second embodiment of the present invention, and FIG. 4 is a partial sectional view showing the structure of a conventional optical memory card. In the drawings, 11...Transparent substrate, 12...Recording thin film, 1
3... Heat insulation layer, 14... Protective layer, 15... Laser light, 16... Pit, 21... Guide groove for guidance, 2
2... Guide groove for initial setting position, 23... Guide groove for recording, 24... Transparent substrate, 25... Recording thin film, 26
... Heat insulation layer, 27 ... Protective layer, 41 ... Guide groove for guidance, 42 ... Guide groove for initial setting position, 43 ...
This is a guide groove for recording.

Claims (3)

[Claims] (1) An optical memory card characterized in that a guide groove for specifying a recording location, a guide groove for guiding to an initial setting position, and a recording thin film are formed on a card-shaped base. (2) The optical memory card according to claim 1, wherein the guide groove for guiding to the initial setting position is a plurality of branch paths. (3) The optical memory card according to claim 1, wherein the guide groove for guiding to the initial setting position is a meandering path.