JPH0778909B2 - Optical disc test disc - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a test disc of an optical disc capable of recording, reproducing or erasing digital signals such as video discs, digital audio discs (eg compact discs), still image / document files and the like. It is a thing.

2. Description of the Related Art In general, optical discs are promising as information media due to their extremely high information density, high S / N ratio, and low noise, and have been commercialized as video discs and digital audio discs to record digital signals. In recent years, research and development has also been carried out as an optical disc for reproduction.

FIG. 5 shows an outline of a compact disc which is a conventional general digital audio disc. This is PCM
The converted digital signal is recorded on the resin substrate in the form of pit rows and reproduced by the semiconductor laser light.

In FIG. 5, 1 is a disk, 2 is a resin substrate, 3 is a digital signal portion in the form of pits provided on the resin substrate 2,
Reference numeral 4 is a reflective film formed on the surface of the protective film, 5 is a protective film coated on the reflective film 4, 6 is a label printing film provided on the protective film 5, and 7 is a semiconductor laser beam for reproduction. Since the reflection film 4 reproduces a digital signal, the protective film 5 protects the reflection film, and the label printing film is necessary for disc identification.

Regarding a conventional optical disc, if there is a defect on the disc reading surface due to scratches, the optical disc player may not be able to properly reproduce the digital signal and may cause a reproduction abnormality such as track jump or noise generation. is there. It was extremely difficult to simulate these scratches, and there was no good test disc for the optical disc. However, there is a conventional example in which a scratch is adhered in a direction orthogonal to the track and a scratch is adhered by a certain width. FIG. 3 shows a plan view of a conventional test disc of an optical disc. Reference numeral 1 is a disk, and 8 is a scratch formed in a direction orthogonal to the track direction.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention However, in the above configuration, scratches are adhered in a direction orthogonal to the track direction of the disk, and the scratches are completely generated during a certain track length, so that the area of the laser beam missing portion is large. There were problems such as too much and not being a simulation of actual scratches.

In view of the above problems, the present invention provides a test disc that is an optical disc that simulates scratches that may adhere during actual handling.

Means for Solving the Problems In order to solve the above-mentioned problems, the test disk of the optical disk of the present invention has a line of each printed film on the disk reading surface that is orthogonal to the radial direction and is substantially parallel to the track direction. By providing a plurality of print films having the same width, length, and depth, a scratch disk is simulated.

With the above-described structure, the present invention provides a plurality of print films having the same line width, length, and depth on the disk reading surface in the direction orthogonal to the radial direction and substantially parallel to the track direction. By simulating an actual scratch, it is possible to reliably obtain a test disk of an optical disk for measuring the playability of the optical disk player.

Embodiment A test disk, which is an optical disk according to an embodiment of the present invention, will be described below with reference to the drawings. FIG. 1 is a plan view of a test disc, which is an optical disc according to the first embodiment of the present invention. In FIG. 1, three print films 9 having a line width of 50 μm, a length of 2 mm, and a depth of 100 μm are attached in parallel with the track direction in a direction orthogonal to the radial direction to form a first scratch simulation 10. As described above, the provision of the three print films 9 substantially parallel to the track direction means that
When reproducing a digital signal, it is possible to obtain missing information that is approximately proportional to the length of the scratch, and for a time of several tens of seconds, missing parts and normal parts exist alternately. In addition, the first flaw simulation 10 is very close to the actual flaw.

FIG. 4 shows an RF waveform which is an electric characteristic seen from the reproduction player of the first scratch simulation 10. Here, FIG. 4a shows an RF waveform when an actual scratched disc is reproduced, and FIG. 4b shows an RF waveform when the first printed film simulation 10 according to one embodiment of the present invention is reproduced. For reference, FIG. 4c shows an RF waveform when the scratched disc shown in FIG. 3 which is a conventional example is reproduced. Thus, the first
It is clear from the electrical characteristics that the flaw simulation 10 of 10 is very close to the actual flaw.

A second embodiment of the present invention will be described below with reference to the drawings. FIG. 2 is a plan view of a test disc, which is an optical disc according to the second embodiment of the present invention. Second
In the figure, in the direction orthogonal to the radial direction of the optical disc,
Line width 50μm, depth 100μ, almost parallel to the track direction
3 sets of 3 print films each having m and a pitch of 300 μm are provided, and the lengths thereof are changed to 5 mm, 3 mm and 2 mm, respectively, and the first scratch simulation 10, the second scratch simulation 11 and the third scratch simulation 12 are performed. To do. According to this, by providing a plurality of scratch simulations in one optical disc, it is possible to make the optical disc optimal as a test disc for measuring the playability of the reproducing optical disc player.

It is also possible to obtain a test disk having the same effect by making the line width, the depth and the length the same and changing only the pitch of the printed film.

As described above, according to the present invention, a plurality of print films having the same line width, length, and depth are formed on the disc reading surface and are substantially parallel to the track direction in the direction orthogonal to the radial direction. By providing the scratches, a scratch simulation similar to an actual scratch can be performed, and the playability of the playback optical disk player can be measured. In addition, by freely changing the pitch and length of the printed film to form multiple scratch simulations within one disc, we provide a test disc of a highly reliable optical disc for playability measurement of a playback optical disc player. can do.

[Brief description of drawings]

FIG. 1 is a plan view of a test disc of an optical disc according to the first embodiment of the present invention, FIG. 2 is a plan view of a test disc of an optical disc according to the second embodiment of the present invention, and FIG. 3 is a conventional optical disc. FIG. 4 is a plan view of the test disc, FIG. 4 shows an RF waveform of electric characteristics in the reproduction optical disc player, FIG. 4a is an RF waveform diagram of an actual scratch disc, and FIG. 4b is the first embodiment of the present invention. Fig. 4c is an RF waveform diagram of a test disc of an optical disc, Fig. 4c is an RF waveform diagram of a conventional test disc, and Figs. 5a, 5b, and 5c are plan views, cross-sectional views, and main parts of a compact disc, which is a type of optical disc. FIG. 1 ... Disk, 9 ... Printed film, 10 ... First flaw simulation, 11 ... Second flaw simulation, 12 ...
Third scratch simulation.

Claims (3)

[Claims] 1. A line width, a length, and a line width on a disk reading surface which are substantially parallel to the track direction in a direction orthogonal to the radial direction
A test disc of an optical disc, comprising a plurality of printed films having the same depth. 2. The printed film has a line width of 20 to 100 μm and a length of 1 to 1
The test disc of the optical disc according to claim 1, wherein the test disc is 0 mm, the depth is 20 to 500 μm, and the pitch is 50 to 500 μm. 3. The line width and depth of each print film, which is substantially parallel to the track direction in the direction orthogonal to the radial direction on one disk reading surface, are the same, and only the pitch or the length is sequentially changed. A test disc of an optical disc having a scratch simulation shape formed by a plurality of printed films.