JPS6334751A - Positioning method for recording disk at the time of jointing - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a positioning method when joining two recording disks on which information is recorded.

[Prior Art] In recent years, in order to increase the amount of recorded information on a recording disk, a recording disk in which two recording disks are joined together has been considered.

Conventional methods for joining this type of recording disk include joining the end surfaces together.

In addition, since the above-mentioned recording disk conventionally reads and writes on one side at a time with pickups placed on the upper and lower sides of the disk, it does not require that much positioning accuracy during joining, and the above-mentioned joining method is not accurate. Ta.

[Problems to be Solved by the Invention] However, when attempting to simultaneously read both sides of a bonded recording disk using the two pickups described above, the conventional bonding method described above can only achieve an accuracy of several hundred microns. Since positioning cannot be performed, for example, even if an attempt is made to position the front pickup and the back pickup on the same track, there is a problem in that one of the pickups will not be positioned on the desired track.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a method for positioning recording disks with high joining accuracy.

[Means for Solving the Problems] In order to achieve the above object, the method for positioning when joining recording disks according to the present invention includes an engaging portion provided on a first recording disk and an engaging portion provided on a second recording disk. The relative positions of both recording disks are determined by engaging the engaging portions, and then marks provided on the first recording disk and the second recording disk that are more precise than the positioning accuracy of the engaging portions. It is characterized by determining the relative position of both recording disks when they are joined by matching them.

Action] First, the engaging portion provided on the first recording disk and the engaging portion provided on the second recording disk are engaged. The positioning accuracy of these engaging portions is not very accurate.

Next, in the engaged state, the mark provided on the first recording disk and the mark provided on the second recording disk are made to match. Positioning accuracy with these marks,
is more accurate than the positioning accuracy of the engaging portion.

Therefore, the relative position of both recording disks when they are joined is determined by the positioning accuracy of the marks.

[Example] An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1(a) is a perspective view of a composite CD (compact disc) joined using an embodiment of the present invention, and FIG. 1(b) is a sectional view taken along the line A-A in FIG. 1(a). , is.

As shown in Figure 1, the composite CDI consists of the first CD3 and the second CD3.
It is composed of CD5. 1st CD3 and 2nd CD
5 each has a diameter of 120 mm.

It is a transparent disk made of acrylic with a thickness of 1.2 mm, and has a center hole 7.9 with a diameter of 25 mm in a part of its center. Information such as a music program is recorded in an information recording area 11.13 on the surface of each disc, starting from a position with an inner diameter of 5Q mm from the center of the disc and ending with a position with an outer diameter of 116 mm from the center of the disc. There is an unrecorded area 15.17 on the center side of the information recorded area 11.13.

In the first CD 3 and second CD 5 configured as described above, the unrecorded areas 15.17, which are the constituent parts thereof, have different shapes from each other. '17 as second
This will be explained based on figures (a) and (b).

FIG. 2(a) is a partial perspective view showing the unrecorded section [15] of the first CD3. As shown in the figure, three protrusions 23 extending in the radial direction are arranged at equal intervals on the back surface 21 of the unrecorded area 15 (the surface opposite to the information recording area 11 side of the first CD 3). ing. Furthermore, three cross marks 25 are provided near the middle of each protruding strip 23. Note that the width 23a of the protruding portion 23 is approximately 1 mm. cross mark 25
The marks were added using photography, and the line thickness is 5 microns.

FIG. 2(B) is a partial perspective view showing the unrecorded area 15 of No. 20D5. As shown in the figure, three concave grooves 33 extending in the radial direction are arranged at equal intervals on the back surface 31 of the unrecorded area 17 (the surface opposite to the information recording area 13 side of the second CD 5). There is. Further, three cross marks 35 are provided near the middle of each groove portion 33. Note that the width 33a of the groove portion 33 is approximately 1 mm. The cross mark 35 is attached by photosensing, and the thickness of the line is 1 micron, and the length of each line is the same as the cross mark 25 of No. 10D3.

Next, a procedure for joining the first CD 3 and second CD 5 configured as described above will be explained.

First, apply adhesive to the back side of No. 20D5, then apply adhesive to the back of No. 20D5, and then
The back surface of the 0D3 and the back surface of the second CD 5 are made to face each other. Next, the first CD 3 and the second CD 5 are pressed so that the protrusions 23 of the first CD 3 fit into the grooves 33 of the second CD 5.

Next, before the adhesive is completely fixed, the first CD3 and the second CD5 are moved relative to each other, so that the cross mark 35 of the second CD3 is completely aligned with the cross mark 25 of the first CD5, as shown in FIG. to roughen. The above cross mark 25.35
The superposition work is performed using a microscope or the like. This completes the positioning for bonding, and after adhering with the adhesive, the composite CD1 is completed.

The method of positioning the recording disks when joining the recording disks of this embodiment described in detail above is based on the 10D3 and 20D5 positions with an accuracy of several tens of microns by fitting the convex stripes 23 and the grooves 25.
It is also possible to join the cross mark 25.3.
5 allows positioning during bonding to be performed with an accuracy of 0.5 microns or less. Therefore, the first CD 3 and the second CD 5 are positioned and joined with high precision.

Therefore, even when pickups are provided on both sides of the composite CD 1 and reading and writing are performed simultaneously from both sides, the pickups can always be positioned on desired tracks, and simultaneous reading and writing from both sides is possible. Furthermore, the tracking control during simultaneous reading and writing on both sides can be performed by one of the pickups, and the other pickup can be configured to follow the tracking control, so that the reading device can have a simple configuration.

Incidentally, in the above embodiment, the convex portion 23 and the concave groove portion 33
The disk has a shape extending in the radial direction with a width of 1 mm, but it may also be configured by, for example, a cylindrical convex portion and a circular concave portion, and holes may be provided in both disks. It is also possible to have a configuration in which they are inserted into each other and fitted together.

Furthermore, the cross marks 25 and 35 in the above embodiment may be changed to marks of other shapes, and the marks may be used for the pins 1 of both recording disks.

Effects of the Invention As detailed above, the positioning method for joining recording disks of the present invention involves engaging an engaging portion provided on a first recording disk and an engaging portion provided on a second recording disk. let me,
Next, highly accurate marks provided on the first recording disk and the second recording disk are made to match each other. For this reason, the relative position of both recording disks when they are joined can be determined with high precision.

Therefore, even when a composite disk bonded using the positioning method for bonding recording disks of the present invention is provided with pickups on both sides and read and written from both sides at the same time, the pickups are always positioned at the desired track. It is possible to read and write on both sides simultaneously. Further, the tracking control during simultaneous reading and writing on both sides can be performed by one of the pickups, and the other pickup can be configured to follow the tracking control,
The reading device requires a simple configuration.

[Brief Description of the Drawings] Figure 1 (A) is a perspective view of a composite CD (compact disc) joined using an embodiment of the present invention, and Figure 1 (B) is a perspective view of Figure 1 (A). FIG. 2(a) is a partial perspective view showing the unrecorded area of the first CD, and FIG.
Figure (b) is a partial perspective view showing the unrecorded area of the second CD, and Figure 3 is an explanatory view showing a state in which the cross marks provided on each CD match. 1... Composite CD (compact disc) 3... 1st
CD 5...Second CD 15.17...Unrecorded area 23...Convex strip 33...Concave groove 25.35...Cross mark

Claims (1)

[Claims] By engaging the engaging part provided on the first recording disk and the engaging part provided on the second recording disk, the relative positions of both recording disks are determined, and then the first recording disk and the second recording disk A method for positioning when joining recording disks, characterized by determining the relative position of both recording disks when joining by matching marks provided on the disks that are more precise than the positioning accuracy of the engaging portion. .