JP2699349B2 - Optical disk test disk and method of manufacturing the same - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a test disk of an optical disk capable of recording, reproducing or erasing digital signals such as a video disk, a digital audio disk (for example, a compact disk), a still image and a document file, and the like. The present invention relates to the manufacturing method. 2. Description of the Related Art In general, optical disks are regarded as promising as information media because of their extremely high information density, high S / N ratio, and low noise, and have been commercialized as video disks and digital audio disks to record digital signals. In recent years, research and development have been performed on optical discs for reproduction. FIG. 3 shows an outline of a compact disk which is a conventional general digital audio disk. This is a PC
The M-converted digital signal is recorded in a pit array on a resin substrate and reproduced by a semiconductor laser beam. In FIG. 3, reference numeral 1 denotes a disk, 2 denotes a resin substrate, 3 denotes a digital signal portion in the form of pits provided on the resin substrate 2, 4 denotes a reflection film formed on the surface thereof, and 5 denotes a reflection film 4 coated thereon. The reference numeral 6 denotes a label printing film provided on the protective film 5, and 7 denotes a semiconductor laser beam for reproduction.
The reflective film 4 is required for reproducing digital signals, the protective film 5 is required for protecting the reflective film, and the label printing film 6 is required for disc identification. In the case of conventional optical discs, if there is a defect due to a scratch on the disc reading surface, the optical disc player cannot reproduce the digital signal normally and may cause reproduction abnormalities such as track jumps and noise. is there. It was very difficult to simulate these flaws, and no good optical disk test disk existed. Further, as a conventional example, a method of attaching a scratch on a disk reading surface by a method such as marking has been attempted. Problems to be Solved by the Invention However, in the above-described configuration, it is difficult to keep the size and depth of the scratches constant when the scratches are adhered on the disk reading surface by a method such as marking, so that the test is difficult. There are problems that the reproducibility cannot be obtained as a disc and that the same scratch can be attached in a large amount. The present invention has been made in view of the above problems, and provides an optical disk test disk that can be simulated as an actual scratch and that can be reproduced in large quantities with good reproducibility, and a method of manufacturing the same. Means for Solving the Problems In order to solve the above problems, the test disk of the optical disk of the present invention is formed by molding on a disk reading surface on the side opposite to the side on which the pit row signal portion of the resin substrate is formed. The cross-section is characterized by providing a depression simulating a concave or V-shaped flaw. Further, a method of manufacturing a test disk for an optical disk includes providing a projection having a convex or mountain-shaped cross section on the reading surface side of a molding die, forming a resin substrate by an injection or compression molding method, On the disk reading surface on the side opposite to the side on which the pit row-shaped signal portion is formed, a cross-section having a shape opposite to the protrusion is formed to simulate a concave or V-shaped scratch. It is a feature. According to the present invention, there is provided a disk on which a reproduction laser beam input to a reproduction apparatus on a side opposite to a side on which a pit row signal portion of a resin substrate is formed by a user when handling the disk by the above-described configuration. A test disk that simulates actual scratches on the reading surface is formed by molding, so it can be provided with good reproducibility, in large quantities and at low cost. It can measure and evaluate the playability of optical disc players. Embodiment An optical disk test disk and a method of manufacturing the same according to an embodiment of the present invention will be described below with reference to the drawings. FIGS. 1a and 1b show a plan view and a sectional view of an optical disk test disk 8 according to an embodiment of the present invention. FIG. 1a
Numeral 9 indicates a simulated flaw provided on the reading surface side of the resin substrate 2 by molding, and its cross section is formed in a V shape as shown in FIG. 1b. In this case, the cross-sectional shape may be concave, that is, it suffices that there is a recessed portion simulated as a flaw in molding. Next, a method for manufacturing the optical disk test disk of the present invention will be described. FIG. 2 shows a sectional view of the manufacturing method. The stationary mold 10 is provided with a projection 11 having a convex or mountain-shaped cross section for forming a simulation flaw. The movable mold 12 is provided with a stamper 13 on which a signal is formed, and a resin melted from a resin inlet 15 is injected into a cavity 14 between the fixed mold 10 and the movable mold 12 to be molded. In this case, a concave portion having a shape opposite to the shape of the protrusion 11 is formed on the fixed mold surface side of the resin substrate, that is, on the reading surface side of the disk. According to the method shown in this embodiment, a simulation flaw corresponding to this is easily formed by arbitrarily changing the shape of the projection, and a large number of optical discs having simulation flaws having extremely stable shapes are formed by the molding method. It is possible to produce. Effect of the Invention As described above, the test disk of the optical disk of the present invention has a concave or V-shaped cross section on the disk reading surface opposite to the side on which the pit-pit-row signal portion of the resin substrate is formed. Providing a depression that simulates a scratch on the shape, and also providing a projection with a convex or mountain-shaped cross section on the reading surface side of the molding die, forming a resin substrate by injection or compression molding, A recess is formed on the disk reading surface of the resin substrate opposite to the side on which the pit row signal portion is formed, the recess having a cross section having a shape contradictory to the protrusion and having a concave or V-shaped scratch. By doing so, the user can read the laser beam for reproduction of the reproducing apparatus on the side opposite to the side on which the signal portion in the form of pits of the resin substrate formed in handling the disk is formed. Since the test disk that simulates the actual scratches is formed by molding, the test disk is highly reproducible and highly reliable, and can be provided in large quantities at low cost. Can be measured and evaluated for the playability of the optical disc player. Also, a desired simulation flaw can be obtained by arbitrarily changing the shape of the protrusion of the molding die.

BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1a and 1b are a plan view and a sectional view of an optical disk test disk according to an embodiment of the present invention, FIG. 2 is a sectional view showing a method of manufacturing the optical disk test disk, and FIG. a, b, c
FIG. 1 is a plan view, a sectional view, and an enlarged view of a main part of a compact disk which is a kind of an optical disk. 2 ... resin substrate, 8 ... optical disk test disk, 9
... Simulation scratch, 10 ... Fixed mold, 11 ... Protrusion, 12 ... Movable mold, 13 ... Stamper, 14 ... Cavity, 15 ... Resin inlet.

Claims (1)

(57) [Claims] An optical disk test disk having a concave portion or a V-shaped scratch formed on a disk reading surface of a resin substrate on a side opposite to a side on which a pit row signal portion is formed by simulating a concave or V-shaped scratch. . 2. A protruding portion having a convex or mountain-shaped cross section was provided on the reading surface side of the molding die, a resin substrate was formed by injection or compression molding, and a pit row signal portion of the resin substrate was formed. A method for manufacturing an optical disk test disk, comprising: forming a recess on the disk reading surface opposite to the side simulating a concave or V-shaped scratch whose cross section is opposite to the protrusion.