JPH0526486Y2 - - Google Patents

Description

[Detailed explanation of the idea]

[Industrial Application Field] The present invention is a method for measuring with high accuracy the warp (or flatness) shape of a thin plastic hollow substrate (hereinafter referred to as a disk) used as an optical disk. This invention relates to a warpage measuring device. [Prior art] Conventionally, a non-contact method for measuring warp on the surface of a disc made from transparent and soft plastic material was developed in the Showa era.
Proceedings of the 60th Japan Society of Precision Machinery Autumn Conference Academic Lectures.
As described on pages 711-712, a method has been reported in which an optical head is used as a sensor and the disk is rotated or reciprocated relative to the sensor to measure and record the warped shape of the disk in the diametrical direction. This method of supporting a flaky disc uses an outer periphery holder having a structure in which the outer periphery of the disc 1 is supported on the inner tips of four arms 2, as shown in FIGS. 5a and 5b. Note that FIG. 5a shows a plan view, and FIG. 5b shows a side sectional view. The arm 2 is inserted into a groove formed at four equal positions on the surface circumference of a ring-shaped base 5, and a disk-shaped groove for positioning the outer circumference of the disk 1 is provided on the upper surface of the arm 2. A plate 6 is attached to the bottom surface, and an O ring 4 is attached to the bottom surface, and a set screw 3 is attached.
It is tightened and assembled. At the other end of the arm 2, a knob 7 is attached to the base 5 via an awl ring 8. The base 5 has cutout holes 9 formed at four locations as escapes for attaching and detaching the disc 1 to and from the arm 2 by pinching it with tweezers. To adjust the leveling of the disc 1 relative to the sensor (not shown), rotate the four knobs 7 appropriately to elastically deform the O ring 8 and move the arm 2 up and down. 2
This is done by moving up and down the inner tip of the disc, that is, the part that is in contact with the disc 1. The warped shape of the disk 1 can be measured by installing the base 5 into a moving table (not shown) that rotates or reciprocates with respect to the sensor, and then measuring and recording the gap between the sensor and the disk surface. It will be done. [Problems to be solved by the invention] When measuring the warpage of thin plastic substrates with low rigidity or large-diameter discs, the conventional disc warp measuring device described above tends to bend the center of the disc due to its own weight. The deflection deformation caused by falling becomes extremely large,
It becomes impossible to measure the true warpage (warpage without the influence of its own weight). In addition, optical disks require warpage measurement under the same operating conditions as when the circular hole in the center of the disk is attached to a hub-equipped spindle, but there is also the drawback that conventional equipment cannot measure the warpage. It is an object of the present invention to provide a disk warpage measuring device that can eliminate the above-mentioned drawbacks of the conventional method and measure true warpage or warpage in various support systems. [Means for solving the problem] The disc warp measuring device of the present invention replaces various saucer-shaped support holders that can support the disc on its inner periphery, outer periphery, inner and outer periphery, and hold the spindle. It is characterized by being prepared as possible. [Operation] The present invention solves the conventional problems by adopting the above-mentioned configuration. In other words, by using replaceable support holders prepared for each type of support method, it is not only possible to measure the warpage of the support method that matches the purpose, but also to realize warpage measurement that is almost unaffected by its own weight. effective. [Embodiment] Figures 1a and 1b are a plan view and a sectional side view, respectively, showing a first embodiment of the present invention, and show an apparatus equipped with inner and outer periphery holders. That is, the device of this embodiment differs from the conventional device shown in FIG.
Moreover, an inner and outer peripheral holder 11 is newly interposed between the arms 2. The inner and outer periphery holder 11 has grooves 12 for mounting the four arms 2 at equal quarter positions on the outer periphery of the back surface, and inner and outer protrusions 13 and outer periphery for supporting the inner and outer peripheries of the disk 1 on the front side. It is a hollow saucer-shaped disc with projections 14 formed thereon. FIG. 2 is a side sectional view showing the structure of an inner holder according to a second embodiment of the present invention. The inner circumferential holder 21 is provided with a groove 12a on the back surface, similar to the inner circumferential holder 11 of FIG. It is a hollow saucer-shaped disc. FIG. 3 is a side sectional view showing the structure of the outer holder according to the third embodiment of the present invention.
1 is provided with a groove 12b on the back surface, and an outer peripheral protrusion 14 for supporting only the outer peripheral edge of the disk 1 on the front surface side.
It is a saucer-shaped disc with a. FIG. 4 is a side sectional view showing the structure of a spindle fixing holder according to a fourth embodiment of the present invention. Stepped part 43 for fixing
is a saucer-shaped disc formed in the center. The hub 44 holds the disc 1 in combination with the stepped portion 43 of the fixed holder 41. The fixing screw 45 is a screw for attaching the disk 1 and the hub 44 to the fixing holder 41. The leveling adjustment and warpage shape measurement for the sensor of the disk 1 in FIGS. 1 to 4 are performed in the same manner as shown in FIG. 5, but the method of supporting the disk 1 on the arm 2 is different. By exchanging and using various holders, there is an advantage that measurement according to the purpose can be easily achieved, such as warpage measurement without the influence of own weight or warpage measurement when the spindle is fixed. For example, for an optical disk substrate made of polycarbonate (PC) resin, a 5-inch diameter substrate (outer diameter
130mm, inner diameter 15mm, thickness 1.2mm) and 8-inch diameter board (outer diameter 200mm, inner diameter 30mm, thickness 1.2mm), assuming that the amount of warpage when there is no influence of its own weight is zero, and calculate the relationship between various support methods and warpage. The result is as shown in Table 1. This calculated value can be used, for example, in the Mechanical Design Handbook (round

[Effect of idea]

As explained above, the disc warp measuring device of the present invention is capable of replacing the conventional four
It is possible to evaluate the warping of the inner peripheral support, inner and outer peripheral support, and spindle fixing method, which was difficult to measure when supporting the outer peripheral of a book arm.In addition, it is possible to apply a support method that can ignore the warping caused by the own weight, so it is possible to This is extremely effective for measuring warpage.

[Brief explanation of the drawing]

FIG. 1 is a diagram illustrating a disk warpage measuring device equipped with an inner and outer periphery holder, which is the first embodiment of the present invention, in which a is a partially cutaway plan view of the disk, b is a side sectional view, Figures 2 to 4 are side sectional views illustrating the structures of the inner holder, outer holder, and spindle fixing holder, which are the second to fourth embodiments of the present invention, respectively, and Figure 5 shows the warpage of the conventional disc. FIG. 2 is a side sectional view illustrating a measuring device. 1... Disc, 2... Arm, 3... Set screw,
4 and 8... O-ring, 5... Base, 6... Washer, 7... Knob, 9... Notch hole, 11...
...Inner and outer periphery holders, 12 and 12a to 12c...
Grooves, 13 and 13a... Inner peripheral protrusions, 14 and 14a...
...Outer circumference protrusion, 21...Inner circumference holder, 31...Outer circumference holder, 41...Fixed holder, 43...Stepped portion, 44...Hub, 45...Fixing screw.

Claims (1)

[Scope of Claim for Utility Model Registration] It has a holder on which a thin disc to be measured for warpage is mounted, and a frame having a larger diameter than the disc and a flat top surface, and the above-mentioned from the inside of the frame. A plurality of arms extend radially along the surface, and the tip of each arm has a holder locking part that engages with the groove of the holder. a base having means for adjusting;
A disc warpage measuring device for measuring the warp shape of the disc, which has a movable stage that rotates or reciprocates the base with respect to the sensor, and has a measuring element such as an optical head sensor, and the arm It consists of a combination of a holder configured as shown in (a) to (d) below at the tip, and a holder holding device consisting of an arm for mounting the holder and a base, and it is possible to prevent warpage in any state of the disc. Depending on what you are measuring
A disk warpage measuring device comprising at least one of the holders (a) to (d). (a) An inner circumferential holder with an inner circumferential protrusion for supporting the inner circumferential portion of the disk at the center of the upper surface and a groove that matches the arm tip on the outer circumferential portion of the lower surface; (b) A circular protrusion on the outer circumferential edge of the upper surface. (c) An outer circumference holder in which an outer protrusion for supporting the outer circumference of the plate is formed with a groove on the outer circumference of the lower surface that matches the tip of the arm; (d) An inner and outer periphery holder with a groove formed on the outer periphery of the lower surface to match the tip of the arm, and (d) a hub and a fixing screw provided at the center of the upper surface; A spindle fixing holder with a stepped part for fixing the inner periphery of the disc, and a groove on the outer periphery of the lower surface that matches the tip of the arm.