JPS6134585Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an optical disc that optically records or reproduces information using laser light.

Optical disks are made by irradiating a light-reflecting layer on the base with focused laser light to form a surface area of several micrometers to several tens of micrometers on the light-reflecting layer.
Information is optically recorded by forming pits on the order of μm, or information is optically reproduced by irradiating the formed pits with converged laser light. In order to irradiate the light reflective layer of the optical disc with laser light that is converged to a constant diameter, the distance from the lens surface that converges the laser light to the light reflective layer must be kept strictly constant. Therefore, a focus control system for making the distance from the lens surface to the top of the light reflective layer constant in advance is provided in an optical disk recording/reproducing device. However, the surface of the optical disk is affixed with a label that displays, for example, an index for classifying the information content, and the thickness of the adhesive layer applied to the label is generally uneven, and the label is made of paper. When this happens, the thickness of the label itself becomes uneven due to moisture absorption. Then, in the focus control system, even if the distance from the lens surface to the light reflective layer of the optical disk is set constant in advance, when the optical disk is placed on the turntable via the label, the adhesive Due to non-uniform changes in the thickness of the agent or the paper label itself, a problem arises in that information cannot be accurately recorded or reproduced on the optical disk.

This idea was made in view of the above circumstances, and the light reflection layer of the optical disk has a thickness of several micrometers to several tens of micrometers.
Focus control that maintains the distance between the light reflective layer and the lens surface at a constant value in advance in order to record information by forming pits of the order of . It is an object of the present invention to provide an optical disk in which recording and reproduction of information is not obstructed by a label attached when the optical disk is loaded into an apparatus equipped with a system.

Next, an embodiment of this invention will be described with reference to the drawings. FIG. 1 is a perspective view showing an embodiment of this invention.

In the figure, an optical disc 1 is attached to an annular label 2 whose inner diameter is a diameter D0 larger than the diameter of the turntable on which it is placed, and the optical disc 1 is lighted so that the center of the ring coincides with the center of the optical disc. It is configured by pasting it on the surface of the disk body. In addition,
In this case, the optical disc main body may have any structure as long as it is formed into a disk shape for optically recording and reproducing information. Further, the label 2 may be made of any material such as paper, plastic, metal foil, etc.

The operation of the optical disc 1 configured as described above will be explained. FIG. 2 is a sectional view showing how the optical disc 1 is used.

In the figure, an optical disk 1 to which a label 2 according to the invention is attached is placed on a turntable 5 driven by a motor 6, and a presser member 7 is held on the optical disk 1 by a central shaft protrusion 5A of the turntable 5. is fitted. Then, the laser beam 4 is focused onto the light reflective layer of the optical disc 1 by the lens 3, and information is recorded and reproduced. In this case, the label 2 does not come into contact with the turntable 6, and the surface of the optical disk 1 is in direct contact with the turntable 6, so there may be uneven thickness of the label or the adhesive layer that adheres the label. Accurate recording and reproduction of information will not be hindered by the non-uniform thickness.

Although one embodiment of this invention has been described above, it goes without saying that various modifications are included as long as the gist of this invention is not changed.

As a modification, for example, as shown in FIG. 3, an optical disc 1 is provided in which a fan-shaped label 2' is attached to the optical disc body so that the inner diameter part of the label 2' is located outside the mounting surface of the turntable. ' can be mentioned.

According to this invention, even if the thickness of the adhesive layer that adheres the label is uneven, or even if the thickness of the label itself is uneven, the optical disk will not be placed on the turntable through the label. So,
This improves the mounting accuracy of the optical disk, and makes it possible to record and reproduce information more accurately.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an optical disk as an embodiment of the invention, FIG. 2 is a sectional view showing the optical disk in use, and FIG. 3 is a perspective view showing another embodiment of the invention. be. 1... Optical disk, 2... Label, 5... Turntable.

Claims (1)

[Claims for Utility Model Registration] (1) An optical disc having an outer diameter larger than the outer diameter of a turntable, characterized in that a label is affixed to the outside of the turntable mounting surface of the optical disc body. (2) The optical disk according to claim 1 of the utility model registration claim, in which the label is annular. (3) The optical disk according to claim 1 of the utility model registration claim, wherein the label is fan-shaped.