JPH04366438A - Stamper reproduction inspecting device - Google Patents

Abstract

PURPOSE:To accurately perform required inspections on signal errors, etc., and, at the same time, to efficiently manufacture an optical disk so as to avoid problems in advance by providing a transmissive plate to an optical disk reproducing pickup. CONSTITUTION:After an optical disk to be inspected is set on a turntable 10, the optical disk is displaced in parallel to a pickup section by sliding the table 10, etc., as they are. The pickup section is provided with two kinds of pickups, a pickup 20 for CD/LD used for reproducing compact disks and laser disks and another pickup 22 for MO used for reproducing magneto-optical disks, and the head sections of the pickups are respectively fitted to positioning feed stages 24 and 26. In addition, since a transmissive plate 90 for compensation is provided to each head section, the surface of a stamper 100 is accurately focused and error checking can be performed on the stamper 100 itself. Therefore, occurrence of unacceptable products can be prevented and causes of errors can be investigated.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reproduction inspection apparatus for a stamper used in the manufacture of optical discs.

0002

2. Description of the Related Art Optical discs such as compact discs, laser discs, and magneto-optical discs are mass-produced by injection molding using stampers as molds. A stamper is a copy of the recording surface of a master disc for injection molding, and after forming the master disc, vapor deposition and nickel plating are applied to the recording surface of the master disc, and the unevenness of the recording surface is transferred to form the stamper. The optical disc is manufactured by setting this stamper in a molding machine and performing injection molding. Therefore, if there is a scratch on the stamper, a signal error, or a signal input error, this will be reflected on the disk product, causing product defects. Since the stamper plays an extremely important role in the optical disc manufacturing process, the stamper is checked for scratches and the like before injection molding.

By the way, since optical disks are used for data processing, products are required to have extremely high reliability. Therefore, it is necessary to strictly check for signal errors, signal input errors, etc. Conventionally, such error checks have been performed on products that have been actually injection molded using a stamper and have been provided with a reflective film or the like. That is, the product is attached to an optical disc playback device. If, for example, the guide groove of the magneto-optical disk is found to be cut during the product check, measures are taken to protect the defective sector from being used.

0004

[Problems to be Solved by the Invention] However, checking the product at the final product stage as in the past involves a large waste of process. Injection molding involves working in a certain number of lots, so if there is a fundamental problem with the stamper, all of the molded products manufactured may be defective. Therefore, during manufacturing, it is desirable to carry out necessary inspections on the stamper itself before molding with the stamper before proceeding with manufacturing. Conventionally, the reason why optical discs are first inspected at the production stage is because there is no equipment that can accurately inspect the stamper itself, and inspections have to be carried out using conventional optical disc playback equipment.

[0005]Furthermore, as an essential problem with the conventional inspection method as described above, since the product is inspected after undergoing processes such as injection molding, signal errors, signal input errors, mechanical scratches, etc. When a problem occurs, it may not be possible to easily determine whether the problem is caused by the stamper itself, a problem during injection molding, or another manufacturing process after that. As a result, there was a problem in that it was not possible to take appropriate measures to solve the problem. Therefore, the present invention has been made to solve the above-mentioned problems, and its purpose is to accurately perform necessary inspections such as signal errors on the stamper itself used in manufacturing optical discs such as compact discs. The object of the present invention is to provide a stamper regeneration inspection device that can eliminate waste in the production of optical discs and prevent problems in advance.

[0006]

Means for Solving the Problems The present invention has the following configuration to achieve the above object. That is, it is a stamper regeneration inspection device for regenerating a stamper used in the manufacture of optical discs and inspecting the product for signal errors, etc., which includes a turntable for setting an object to be tested on the stamper, a motor for driving the turntable, etc. a set section having a set section, a pickup section for checking signals etc. on the recording surface of the object according to the type of optical disk, and an analysis for analyzing the detection signal by the pickup section and outputting for predetermined inspection items. It is characterized by having a display section. Further, the present invention is characterized in that it is provided with a pickup section capable of detecting signals for objects such as compact discs, laser discs, and magneto-optical discs. Further, the pickup section is characterized in that a pickup for reproducing an optical disk is provided with a transmission plate for compensating the optical distance of a transparent film portion formed on the recording surface of the optical disk.

[0007]

[Operation] The test object of the stamper is set on the turntable of the setting section, the pickup section detects the playback signal and measurement signal of the test object, and the analysis display section analyzes the playback signal and measurement signal for the required inspection items. and output it. By providing a pickup unit for compact discs, laser discs, and magneto-optical discs, any optical disc can be tested in a general manner. By providing the transmission plate in the pickup section, it becomes possible to reproduce and inspect the stamper itself.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the stamper regeneration inspection apparatus according to the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 shows a block diagram of a stamper regeneration inspection device. The stamper regeneration inspection device of the embodiment checks errors by regenerating the stamper itself, and includes a setting section for setting the stamper, a pickup section for detecting the reproduction signal, and control and signal processing of the pickup section and the setting section. The main component is the control section that performs the operations.

The setting section includes a turntable 10 for setting the stamper, a servo motor 12 for rotationally driving the turntable 10, and a drive section 1 for the servo motor 12.
4 and a controller 16 that controls the drive unit 14.
has. In the embodiment, after an optical disc to be examined is placed on the turntable 10 and set, the turntable 10 and the like are slid and moved in parallel to the pickup section. 18 is a loading stage for this slide movement.

The pickup section includes a CD/LD pickup 20 used for reproducing compact discs and laser discs, and an MO pickup 20 used for reproducing magneto-optical discs.
There are two types of pickups 22 for use. The head portion of the CD/LD pickup 22 and the head portion of the MO pickup 22 are respectively attached to feed stages 24 and 26 for moving and positioning to predetermined positions relative to the subject. 28 and 29 are scales for positioning. The CD/LD pickup 20 and the MO pickup 22 are connected to the focus servo control section 3.
Optical focus control and signal processing are performed by signal processing units 34 and 36.

The control section comprehensively controls the setting section and the pickup section, and outputs inspection results for the optical disk object based on the detection results of the pickup section. Control units 30, 32, signal processing units 34, 36
It is provided with a control unit 40 for controlling the above, an output terminal 42 for test results, and a control panel 44.

The stamper reproducing inspection apparatus having the above structure is characterized in that it inspects the stamper in the same manner as an optical disc reproducing apparatus, and by placing the stamper to be inspected on the turntable 10 and setting it, the recording surface of the stamper is inspected. It scans and outputs inspection results for required inspection items such as signal errors and signal input errors. In actual use, the stamper is set on the turntable 10 and inspection is performed by performing predetermined operations on the control panel 44. The subject is automatically moved to the pickup section, a turntable is driven, and an error check is performed using a predetermined pickup in the same manner as when playing back an optical disc. The testing apparatus of the embodiment tests compact discs, laser discs, and magneto-optical discs, and can test any stamper with simple operations.

FIGS. 2 and 3 are explanatory diagrams of a specific embodiment of the stamper regeneration inspection apparatus. FIG. 2 shows the arrangement of each part when the device is viewed from the front, and FIG. 3 shows the schematic arrangement of each part when viewed from the plane. As shown in Figure 2, the inspection device is box-shaped, with a door 5 in the center of the front that opens and closes left and right.
0 is set. The turntable 10 is placed inside the device with the opening/closing door 50 open. The stamper of the test object is tested by opening the opening/closing door 50 and setting it on the turntable 10.

The turntable 10 is supported by a slide base 52 whose longitudinal direction is in the left-right direction when viewed from the front, and the slide base 52 is supported by a loading slide unit 54 that moves the slide base 52 in the front-back direction. A loading slide guide 56 is a guide for moving the slide base 52 back and forth. A servo motor 12 that drives the turntable 10 is supported below the slide base 52. 58 is turntable 10
It is an air bearing that supports the 60 is a magnet plate provided on the top surface of the turntable 10. The magnet plate 60 is used to magnetically attract and support the subject to the turntable 10. The turntable 10, servo motor 12, etc. are mounted on the slide base 5.
2, and moves back and forth with the movement of the slide base 52.

The pickup section is installed at a position slightly above the turntable 10 at the back of the inspection apparatus. 62
is a CD/LD pickup head, and 64 is a CD/L pickup head.
This is the control unit for the D pickup. 66 is an MO pickup head, and 68 is a control unit for the MO pickup. The CD/LD pickup head 62 and the MO pickup head 66 are attached to a pickup head elevating slide unit 70 and are movable in the vertical direction. Pickup head elevating slide unit 70
is fixed to the pickup head unit fixing arm 72. The pickup head unit fixing arm 72 is installed so as to span in the left and right direction at an upper position when viewed from the front, and is supported by a pickup head switching slide unit 74 at the left and right base positions, and is movable in the front and back direction. That is, the pickup head is positioned vertically by the pickup head elevating and lowering slide unit 70, and positioned in the front and rear direction by the pickup head switching slide unit 74.

A touch panel type operation panel 76 and an oscilloscope 78 are arranged on the front side of the inspection apparatus, and a connector terminal 80 for signal output is arranged on the side part. In FIG. 2, 82 is a servo drive unit used to drive each part, and 84 is a power supply section.

The stamper reproducing inspection apparatus of this embodiment employs a configuration different from that of a pickup head used in conventional optical disc reproduction so that the stamper can be reproduced as is. FIG. 4 shows an example of the configuration of the pickup head in this embodiment. FIG. 4(a) is an example.
(b) shows the configuration of a conventional example. The difference in structure between this embodiment and the conventional example is that in the case of this embodiment, a compensation transmission plate 90 is added to the head portion of the conventional example. This transmission plate 90 is provided to inspect the stamper 100 itself, and as shown in FIG. 4(b), the optical disc 1
10, a transmission film 112 is provided in front of the recording surface 110a, so using a conventional pickup head cannot focus and inspect the recording surface of the stamper 100. The above-mentioned transmission plate 90 is a transmission film 112
By providing the stamper 1 so as to compensate for the
It is possible to accurately focus on the test surface of 00, making it possible to check for errors on the stamper itself.

The stamper regeneration inspection apparatus of the above embodiment is handled in the following manner. That is, the stamper to be tested is placed on an aluminum plate with a thickness of 1 to 1.5 mm, and set on the magnet plate 60 of the turntable 10. The purpose of the aluminum plate is to hold the stamper of the test object so that it will not be distorted when it is set on the turntable. The opening/closing door 50 is closed, and the type of subject to be examined is selected and input using the touch panel operation panel 76. The loading slide unit 54 slides the slide base 52 to below the pickup section and stops, and the subject is positioned below the pickup section. The pickup head switching slide unit 74 operates to set the CD/LD pickup head 62 or the MO pickup head 66 at a predetermined position, and the pickup head elevating slide unit 70 operates to lower the pickup head to a predetermined position.

Next, the servo motor 12 is driven, the turntable 10 is rotated, and reproduction inspection by the pickup head is started. The pickup section focuses on the object surface of the stamper as shown in FIG. 4(a), and reproduces the image while controlling tracking. In the inspection device of the example, a gallium-arsenic-aluminum laser diode (0
．． 78 μm) laser beam with a diameter of 1 mm using a condenser lens.
A ~2 μm spot is focused on the stamper surface. The focus of the laser spot irradiated onto the stamper surface is controlled so that the focus accuracy is within ±0.1 μm even if there is waviness on the stamper surface, and the center of the track is controlled to within ±0.1 μm.
Tracking control is performed to trace with an accuracy within the range of 100 to 1000, and the reproduced signal and measurement signal are detected and processed.

The oscilloscope 78 displays the test signal, and connects the connector terminal 80 and the oscilloscope 7.
8 is used by connecting it with a probe. The inspection apparatus of this embodiment uses compact disks, laser disks, and magneto-optical disks as objects to be inspected, and the following are specific inspection items for these objects. Inspection items for CD/LD include (video dropout), (C1, C2, Cu error), (PQ code)
, (RF signal, DC reading conversion), (tracking, focusing OFF, crosstalk inspection), (jitter measurement), etc. MO inspection items include (C1, C2, burst error), (tracking, focusing OFF,
crosstalk inspection), (dropout at CCF signal level), (SN ratio), (RF signal, DC reading conversion),
(Various measurements related to ID preformat signals) etc. FIG. 5 shows an explanatory diagram of inspection methods for various inspection items. 91 is an optical head, 92 is a high frequency amplifier, and 93 is an LD.
APC, 94 is an oscilloscope, 95 is a bit error analyzer, 96 is a flaw analyzer, 97 is a spectrum analyzer for analyzing CNR and crosstalk, 98 is a digital oscilloscope for analyzing jitter, etc., 9
9 is a circuit for measuring reflectance.

After the test is completed, by issuing a loading out command from the operation panel, the pickup elevating slide unit 70 is activated, the pickup head is raised, and the slide base 52 is moved to the front side, allowing the specimen to be taken out. . As described above, the stamper reproducing inspection apparatus of this embodiment can inspect a stamper using the same procedure as that used for reproducing an optical disc in the same way as a conventional optical disc reproducing apparatus. This makes it possible to test the stamper with extremely simple operations, and to perform efficient testing by sequentially replacing the test objects. By checking the quality of the stamper or errors in the stamper at the stage before injection molding, we can screen out stampers that cannot be used for optical disc manufacturing, prevent the occurrence of defective products, and eliminate manufacturing waste. becomes possible.

[0022]

[Effects of the Invention] As described above, according to the stamper re-inspection device according to the present invention, it is possible to easily perform inspections that were not conventionally performed at the stamper stage, and the stamper can be inspected efficiently. In addition, by finding stamper scratches, signal errors, signal input errors, etc. in advance, it is possible to prevent the occurrence of defective products. It is also effective in that it can be effectively used to investigate the cause of errors at the product stage, such as whether or not they are caused by the stamper.

[Brief explanation of drawings]

FIG. 1 is a device block diagram of a stamper regeneration inspection device.

FIG. 2 is a front view of the stamper regeneration inspection device.

FIG. 3 is a plan view of the stamper regeneration inspection device.

FIG. 4 is an explanatory diagram showing the configuration of a pickup section.

FIG. 5 is an explanatory diagram showing an inspection method.

[Explanation of symbols]

10 Turntable 12 Servo motor 18 Loading stage 20 CD/LD pickup 22 MO pickup 30, 32 Focus control section 34, 36 Signal processing section 40 Control section 52 Slide base 54 Loading slide unit 60 Magnet plate 62 CD/LD pickup Head 66 MO
Pickup head 70 Pickup head elevating slide unit 72
Pickup head switching slide unit 76
Touch panel operation panel 78 Oscilloscope 90 Transmission plate 100 Stamper 110 Optical disk

Claims (3)

[Claims] 1. A stamper regeneration inspection device for regenerating a stamper used in the manufacture of optical disks and inspecting the product for signal errors, etc., comprising: a turntable for setting an object to be tested on the stamper; and a motor for driving the turntable. a set section having a drive section such as a set section, a pickup section for checking signals etc. on the recording surface of the object depending on the type of optical disc, and an analysis of the detection signal by the pickup section and regarding predetermined inspection items. 1. A stamper regeneration inspection device, comprising: an analysis display section for outputting data. 2. A stamper reproducing inspection device comprising a pickup section capable of detecting signals from compact discs, laser discs, and magneto-optical discs. [Claim 3] The pickup section is characterized in that the pickup section is a pickup for reproducing an optical disk provided with a transmission plate for compensating the optical distance of a transparent film portion formed on the recording surface of the optical disk. The stamper regeneration inspection device according to claim 1 or 2.