JPH01176342A - Optical recording medium - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an optical recording medium on which information is written and read using light.

(b) Prior Art There are card-shaped and disk-shaped media on which information is written and read using light.

In both of these methods, information is written by irradiating the recording film with laser light to cause optical changes such as refractive index and reflectance in minute parts of the recording film, and reading information is performed using a laser beam with lower power. This is done by using light to read changes in reflectance and transmittance of minute recording areas.

During such readout, it is necessary to accurately track the spot of the readout laser light onto the row of information pits, and conventionally, for example, the method shown in Figure 3 has been adopted ("
Japanese Science and Technology 81/Laser IP73J).

In this method, in addition to the laser beam for recording and reproducing signals, a pair of laser beams are projected slightly shifted from the center of the information track, and the reflected beams are received by a pair of photodetectors 2 to detect both the inner and outer edges of track 1. It was designed to do so. Due to the track displacement, the diffraction of the pair of light beams by the information bit becomes unbalanced, and an output difference appears in the negative pair of photodetectors 2. The track following mirror 3 is driven by this differential output, and tracking is performed with an accuracy of 0.1 μm. Mirror 3. The optical disk was driven using a servo mechanism.

- (C) Problems to be Solved by the Invention Conventionally, optical recording media have been in the form of cards or disks, so there has been a problem in that it is not easy to position the writing or reading head when writing or reading information.

Therefore, as shown in FIG. 3, an auxiliary bare beam system is adopted to drive the track following mirror, but with this system, not only the optical system but also the driving system become complicated. Furthermore, it is not necessarily suitable for high-speed tracking.

B) Means for Solving the Problems The optical recording medium of the present invention is characterized in that the hollow part or inner wall surface of the hollow fiber made of a transparent material is filled or coated with a substance that causes a physical or chemical change when irradiated with light. shall be.

Examples of substances that undergo physical and chemical changes due to light radiation include heat mode materials such as chill, tellurium compounds, and bismuth, and photon mode materials such as spiropyran.

The optical recording medium of the present invention is completed by filling the hollow portion of the hollow fiber or coating the material on the inner wall surface of the hollow fiber and arranging the material on a transparent flat substrate such as glass or plastic.

The number of arrayed optical recording media is approximately 2,000 arrayed in parallel depending on the area of the plane, and the optical recording medium is fixed to the flat substrate using an adhesive.Since the optical recording medium has unevenness on the plane,
A light detection means such as a photodiode array is installed on this unevenness (optical recording material).

Perform tracking.

(e) Function In the present invention, first, light is irradiated from the substrate side or the material side of a flat substrate on which optical recording materials are arranged to write on the optical recording materials.

After writing is completed, a light detection means is installed on the side of the optical recording material having unevenness and reading is performed.

(f) Example An example of the present invention is shown in FIG. FIG. 1(a) shows an optical recording material to be arranged on a flat substrate. This optical recording material is made by filling a glass hollow fiber with a diameter of 5 μm and a length of 5 Q mm with a substance 12 that undergoes a chemical change when irradiated with light, such as spiropyran.

FIG. 1(b) shows an optical recording medium constructed by arranging 2000 pieces of the optical recording material shown in FIG. 1(a) in parallel on a transparent substrate 13 such as glass. The optical recording material R is fixed to the transparent substrate 13 using an adhesive.

The optical recording materials R are arranged in close contact with each other to produce the same level of unevenness.

In the optical recording medium configured as described above, when writing information, a laser beam is irradiated from the substrate side 13 or the optical recording material R side to cause a change in the substance 12 filled in the glass hollow fiber 11.

When reading information, a photodiode array 14e is installed on the optical recording material R (1111) as shown in FIG. Detect.

Reliable tracking operation is possible by placing the needle-like protrusions 15 fixed on the photodiode array on the unevenness of the surface of the optical recording material and moving them in parallel.

Further, during detection, if the photodiode array 14 is installed so as to cover the entire surface of the parallel fiber sheet, it becomes possible to read out all the information at once.

(g) Effects According to the present invention, since the optical recording material itself is completely isolated from the outside air, long-term stabilization is attempted.

Further, tracking can be performed without a complicated servo mechanism.

[Brief explanation of the drawing]

FIG. 1(a) shows an optical recording material according to the present invention.
b) shows an optical recording medium in which the optical recording materials shown in Fig. 1(a) are arranged in parallel, Fig. 2 shows the device configuration for reading information, and Fig. 3 shows the conventional tracking method. FIG. 11...Glass hollow fiber 13--Planar substrate 1
4...Photodiode array 15...Acicular projection

Claims (1)

[Claims] 1. An optical recording medium in which a plurality of optical recording materials, each of which has hollow fibers made of a transparent material filled with a substance that causes physical and chemical changes when irradiated with light, are arranged on a flat substrate. . 2. The optical recording medium according to claim 1, wherein the hollow fibers made of a transparent material are glass fibers.