JPH0294143A - Optical record carrier - Google Patents

Abstract

PURPOSE:To prevent the surface of light incident of an optical record carrier from being directly brought into contact with the surface of a desk, etc., so that no cassette is required for the carrier by forming an air layer structure by means of a spacer section and at the same time, by causing rod pillar members to protrude from the surface of light incident of the carrier. CONSTITUTION:A spacer section 11 protruding from the internal section is integrally provided in at least one marginal side section of a backing and transparent base plates. Recording or reproduction of information is performed concentrically or spirally in or from a recording area 10 and the area 10 is scanned relatively to a laser beam spot while the area 10 rotates. This rectangular optical record carrier has an air layer structure formed by the spacer section 11 and its backing and transparent base plates are integrated by means of rod pillars 12 which protrude from the surface of light incidence of the carrier. Therefore, opportunities of the surface of light incidence for being directly brought into contact with other matters can be reduced and the necessity of a cassette to the carrier is eliminated.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an optical record carrier, and in particular to an optical record carrier, in which information is recorded by irradiation with a laser beam, and the recorded information can be optically reproduced. Concerning the structure of the record carrier.

[Conventional technology]

In recent years, research, development, and commercialization of optical information recording and reproducing systems such as compact discs, write-once discs, erasable magneto-optical discs, and optical discs using phase change materials have been actively conducted. Recently, a cart-shaped record carrier in the form of a card has been proposed, and a compact disc with a diameter of 8 cm called a CD single has also been announced, indicating that optical record carriers are becoming smaller and moving toward shapes that are more advantageous for collaboration. .

A typical example of a conventional optical disc will be explained using FIG. 5.

The structure of a conventional optical disk consists of a back plate 1, a spacer 2, and a transparent substrate 3 on one side of which information tracks are arranged concentrically or spirally and an optical recording material 4 is coated on the tracks.

An air layer 5 of approximately 0.4 mm exists on the recording surface between the back plate 1 and the transparent substrate 3 due to spacers 2. The air layer 5 is provided to prevent the recording sensitivity from decreasing when the back plate 1 comes into contact with the optical recording material 4. Further, the center pole 6 is provided for passing the optical disk through the shaft of the spindle motor and rotating it.

Usually, the spacer 2 is fixed to the back plate 1 and the transparent substrate 3 with an adhesive. In particular, when an inorganic optical recording material is used, it is required to seal it quite strictly with the spacer 2 in order to prevent its characteristics from changing due to moisture.

However, recently, organic optical recording materials have been developed, and this strictness is not necessarily required for organic recording materials.

In such an optical record carrier, a laser beam is made incident from the side of the transparent substrate 3 and focused on a spot of approximately 1 to 2-2 on the surface of the optical recording material to record and reproduce information. Scratches and dirt on surface 7 have a negative effect. Dirt can be removed by washing or wiping, but it is necessary to take some measures to prevent scratches.

For this reason, most conventional optical discs are placed in a protective box (protective case) called a heart cassette and handled as a cassette.

[Invention or problem to be solved]

However, as mentioned above, there has been a recent trend toward requiring smaller and more easily portable structures.
In other words, there is a need for a record carrier that can be easily used by anyone. From this point of view, conventional optical discs have the following drawbacks.

1. To prevent scratches, a cassette is essential;
The price will be higher.

2. Due to the use of a cassette, the thickness is increased (conventionally approximately 10 mm), which is disadvantageous for portability, storage, etc.

3. Complete sealing of the air layer causes high costs.

The present invention aims to provide an optical record carrier that overcomes the following drawbacks.

(Means for Solving the Problems) That is, in the present invention, the periphery of at least one of the back plate and the transparent substrate is a part of a spacer that protrudes from the inside thereof, and both plates are provided with a third member at a corresponding position. A sealed air layer structure can be easily realized by providing a hole through which a bar member passes and fitting the bar member into the hole, or by fusing the bar member with heat or the like. In addition, by protruding the bar member from the light incident surface of the optical recording medium, it is possible to prevent the light incident surface from inadvertently coming into direct contact with the surface of a desk, etc., making it possible to use it without a cassette. .

Hereinafter, the present invention will be explained in more detail with reference to the drawings.

FIG. 1 shows an embodiment of the present invention. The optical record carrier of this example has a rectangular outer shape. Its - side is approximately 10
It is desirable that the diameter be 0 mm or less in consideration of compatibility. Furthermore, the rectangular shape makes handling easier for users who are accustomed to floppy disks and the like. Recording area 1
0, information can be recorded or reproduced concentrically or spirally, and as explained later, is scanned relative to the laser beam spot by rotational movement. A rectangular optical record carrier is
The spacer portion 11 forms an air layer structure, and the back plate and transparent substrate are integrated by a bar 12, which protrudes from the light incident surface. In order to clarify the structure of the optical record carrier of the present invention, the manufacturing method will be explained using FIG. 2.

In FIG. 2(a), the back plate 13 has a spacer portion 11 and a through hole 18. These structures can be easily realized by various plastic molding methods. Moreover, the center hole 16 is also formed at the same time or provided later.

The transparent substrate 14 is provided with group grooves 15 or optical spot guide patterns in a sampling manner using any applicable technique such as injection, compression or 2P method. Further, the through holes 8 of the transparent substrate 14 are also provided corresponding to the number and position of the through holes 18 of the back plate. The material of the transparent substrate 14 is preferably polycarbonate, polymethyl methacrylate, etc., which have optical precision, because the laser beam passes therethrough.

An optical recording material 17 is coated on the group groove 15. Preferred as the optical recording material 17 are anthraquinone derivatives,
Dioxazine compounds and their derivatives, triphuedideazine compounds, phenanthrene derivatives, cyanine compounds, merocyanine compounds, pyrylium compounds, xanthine compounds, triphenylmethane compounds, croconium dyes, azo dyes, crocones, azines, indigoids Desirable examples include methine dyes, azulenes, squalium derivatives, etc. These optical recording materials 17 are relatively resistant to changes in characteristics due to moisture.

As shown in FIG. 2(b), the back plate 13 and the transparent substrate 14 are positioned and integrated using the rod 12 and the through hole 18. At this time,
The tip of the rod portion 12 should protrude slightly from the laser beam projection surface 20 of the transparent substrate 14 (0.5 mm to 3 m).
By determining the length (preferably about 100 m), the entrance surface 2
0 can be prevented from coming into direct contact with, for example, a desk. In addition,
In view of the purpose of the present invention, it is preferable that the entrance surface 20 be coated with a hard coat layer cured with modified acrylic or the like.

Note that when the back plate 13 and the transparent substrate 14 are integrated, the spacer 11, the bar rod portion 12, or the through hole portion 18 may be hardened using an adhesive, but the rod portion 12 protruding from the entrance surface 20 may be A record carrier having an air layer 19 can be easily realized by spot-bonding the tip and the incident surface 20 around it using heat or the like.

FIG. 3 shows a method for recording information on or reproducing information from the record carrier.

The recording carrier 21 can be rotated by passing the spindle portion of the motor 23 through the center hole 22.

Further, the optical head 24, which is composed of components such as a semiconductor laser, an objective lens, an actuator, a photodetector, a mirror, and a beam splitter, is moved by a screw 26 by a motor 25.
and a guide 27, and is movable in the radial direction of the optical record carrier (or in the direction orthogonal to the group), and information is recorded on or reproduced from an arbitrary information track.

The information signal to be recorded is transmitted to the modulation circuit 28, for example, by MFM.
, Fly! , NRZI, etc., and sent to a laser drive circuit 29 that emits laser light. This (No. 3) is sent to the racer in the optical head 24, and records information on the optical recording material with a laser beam spot narrowed to φ1 to 2 press spots on the recording surface. A laser beam is emitted.

The reflected light from the optical record carrier enters the photodetector in the optical head 24, and the electrical signal is amplified by the amplifier circuit 30.
The signal is returned to the original signal in the demodulation circuit 31 and becomes reproduction information.

On the other hand, electrical signals necessary for autofocusing and autotracking are processed by the servo circuit 32 and then sent to the actuator in the optical head 24, so that a minute laser beam spot can always scan the information track during recording or reproduction.

In the first embodiment, an optical record carrier having a rectangular outer shape has been described, but it may also be a conventional one having a circular shape. An example is shown in FIG. 4, in which each component is designated by the same number as in FIG. 1.

〔Effect of the invention〕

As described in detail above, in the present invention, 1) an optical recording medium having an air layer structure can be easily obtained;

2) By making the tip of the rod protrude from the light entrance surface,
This reduces the chance of other objects inadvertently touching the light incident surface, makes it possible to omit the cassette, makes it easier to handle compared to conventional optical discs, and because the thickness is only the optical recording medium. , and requires less storage space.

There are other effects.

[Brief explanation of the drawing]

FIG. 1 and FIG. 2 are diagrams each showing an embodiment of the present invention,
FIG. 3 is a schematic diagram of an apparatus for recording and reproducing information on an optical record carrier, FIG. 4 is a diagram showing another embodiment of the present invention, and FIG. 5 is a diagram showing a conventional optical record carrier. . 10: Recording part 11 Ni spacer part 12: Rod part 15 Nigel loop groove 16. Center hole 17: Optical recording layer 18/Through hole 19: Air layer

Claims (1)

[Claims] 1) In an optical recording carrier having a back plate and a transparent substrate sandwiching an optical recording material, at least one of the back plate and the transparent substrate,
A spacer portion protruding from the inside is integrally provided in the peripheral portion, the back plate and the transparent substrate are integrated with a rod member, and the rod member protrudes from the light incident surface. An optical record carrier characterized by: