JPS61145742A - Optical disk - Google Patents

Abstract

PURPOSE:To produce easily an optical disk that has no recording/reproduction error despite the large number of using times, by providing a projected part of an adhesive tape at the outer circumferential part of a circular substrate containing a recording layer at the opposite side to said recording layer. CONSTITUTION:A projected part 10 is formed by attaching an adhesive tape at the outer circumferential part of a substrate having a recording layer at the opposite side to said recording layer. A surface 11 has no rub owing to the presence of the part 10. Thus, this optical disk has no recording/reproduction error despite of the large number of using times. In addition, the cost reduction is attained with use of the adhesive tape. The part 10 can have a continuous annular form or an annular form having a notched part.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to the structure of an optical disk used in an optical disk storage device.

(Prior art and its problems) Optical disk storage devices record and reproduce information by irradiating a rotating disk with laser light. The optical disk used for this purpose is made by laminating together two circular substrates each having a recording layer on at least one inner surface of which information can be recorded using a laser beam. This structure prevents the surface of the recording layer from being scratched or dusted, which would adversely affect recording and reproduction.

Conventionally, when such optical discs are used many times, errors in recording and reproducing information occur, which has been a problem.

FIG. 3 is a diagram showing the cross-sectional shape of a conventional optical disc.

A recording layer 2 is provided on one side of the resin substrate 1, and an inner peripheral spacer 4 is provided to form a hollow portion 3 with the recording layer 2 inside.
It has a structure in which a substrate 1 is bonded with an outer peripheral spacer 5 interposed therebetween. Recording and reproduction are performed by condensing and irradiating the recording layer with a laser beam through a substrate on which the recording layer is provided. Conventionally, when such optical discs are used many times, errors occur in the recording and reproduction of information, which has been a problem.6 The inventor investigated the cause of this problem and found that it was difficult to store the optical disc. When automatically transported from the stocker to the accessor to the recording/playback station,
Or, when the disc is automatically transported from the recording/playback station to the stocker, the surface of the substrate on which the laser beam is incident (the surface opposite to the surface on which the recording layer is provided) may be scratched by rubbing against other optical discs or mechanical parts. It turned out that it was because of this.

(Object of the Invention) An object of the present invention is to provide an inexpensive optical disc that is free from errors in recording and reproduction even when used many times.

(Structure of the Invention) The optical disc of the present invention is an optical disc in which a plurality of circular substrates having at least one circular substrate having a recording layer of 9j/l on the surface thereof are laminated together with the recording layer inside.
The present invention is characterized in that a protruding portion of the adhesive tape is provided on the outer periphery of the surface of the circular substrate having the recording layer on the side opposite to the recording layer.

(Detailed Description of Configuration) The present invention solves the problems of the prior art by adopting the above-mentioned configuration.

The present invention will be explained below with reference to the drawings.

FIG. 1 is a diagram showing the cross-sectional shape of the optical disc of the present invention. A protrusion 10 is formed by pasting an adhesive tape on the outer periphery of the surface of the substrate having the recording layer on the side opposite to the recording layer. By forming the protrusion 10, the surface 11 will not be rubbed, so it will not be scratched even if it is used many times, and errors in recording and reproducing information will not occur. In the present invention, the protrusions are formed by applying adhesive tape, so that they can be easily realized at low cost.

Note that the protrusion may be a continuous annular body, but
It may be an annular body with an entry.

FIG. 2 is a diagram showing the cross-sectional shape of another optical disc according to the present invention. A substrate 1 having a recording layer 2 and a substrate 12 are directly bonded together with an adhesive, and a protrusion 20 is formed on the outer periphery of a surface 13 opposite to the recording layer by applying an adhesive tape. This optical disc also provides the same effect as the optical disc shown in FIG. IS1.

(Example) Examples of the present invention will be described below.

5-amino-8-(P-ethoxyanilino)-2,3-dicyano-1,4 is placed in the area from φ45mm to φ114mm of the acrylic resin disk substrate with a guide groove of inner diameter 15mmrn1 outer diameter 120mm and thickness L 2mm. - An 800X thick organic thin film containing 90% or more of naphthoquinone dye was formed as a recording layer. These two single disks are φ120mm x φ115mm and φ33mmX with the recording layer inside.
An air sand inch optical disk was prepared by bonding an acrylic resin spacer with a diameter of 16 mm and a thickness of 0.5 mm using an acrylic ultraviolet curing resin.

After that, the outer circumference of the disk is φ115mm to φ120.
An annular protrusion was provided by pasting an adhesive tape with a tape thickness of 2 to 70 mm and 1 m+n to an area of mm.

After repeating the cycle of transporting the optical disc created in this way from the stocker to the recording/playback stage and back to the stocker 170,000 times, there was no error when the first recorded part was played back. The surface of the optical disk without the protrusion was scratched, resulting in error 9.

(Effects of the Invention) As is clear from the above embodiments, according to the present invention, it is possible to easily obtain an optical disc without recording/reproducing errors even when used many times.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an optical disk according to an embodiment of the present invention, and FIG.
This figure is a cross-sectional view of an optical disk according to another embodiment of the present invention, and FIG. 3 is a cross-sectional view of a conventional air sandwich type optical disk. In the figure, 1.12 is a substrate, 2 is a recording layer, 3 is a hollow part, 4 is an inner peripheral spacer part, 5 is an outer peripheral spacer, 10.
20 indicates a protrusion.

Claims (1)

[Claims] In an optical disc in which a plurality of circular substrates each including at least one circular substrate having a recording layer on its surface are bonded together with the recording layer inside, the surface of the circular substrate having the recording layer opposite to the recording layer is An optical disc characterized by having a protrusion of adhesive tape on the outer periphery.