JP2000348391A - Device and system for inspecting deformation of optical dick - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the device for inspecting the deformation of an optical disk by which the deformation of an optical disk substrate can automatically be inspected. SOLUTION: This device is provided with a two-dimensional CCD camera 12 to fetch the chart image reflected by the optical disk substrate, a picture processing part 11 for deciding the normal/defective condition of the optical disk substrate based on a video signal subjected to photoelectric conversion, and a main processor 10 for transmitting the signal corresponding to the result of the decision.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and a system for inspecting deformation of an optical disk substrate such as a transparent substrate immediately after molding when manufacturing an optical disk such as a CD or DVD.

[0002]

2. Description of the Related Art Conventionally, deformation of an optical disk such as a CD or DVD has been measured by using a reflected light from a reflection film of the optical disk using a tilt measuring device or the like.

[0003]

However, such a conventional method has a problem that it is difficult to measure the vicinity of the spindle because a spindle for rotating the disk is required.

In the conventional measurement method, since the measurement is performed using the light reflected from the reflection film, the deformation of the transparent substrate immediately after molding cannot be measured.

In addition, since the measurement is performed after the reflective film is deposited, there is a problem in that the steps such as the deposition step after forming the transparent substrate of the optical disc are wasted.

Accordingly, an object of the present invention is to provide an optical disk deformation inspection apparatus and an optical disk deformation inspection system capable of automatically inspecting an optical disk substrate for deformation.

[0007]

In order to achieve the above object, the invention of claim 1 comprises a photoelectric conversion means for taking in a chart image reflected on an optical disk substrate, and a photoelectric conversion means for converting an optical disk substrate based on a photoelectrically converted video signal. An optical disc deformation inspection device includes a determination unit for determining pass / fail and a control signal transmission unit for transmitting a signal corresponding to the determination result.

According to a second aspect of the present invention, there is provided a photoelectric conversion unit for capturing a chart image reflected on an optical disk substrate, a determination unit for determining the quality of an optical disk substrate based on a photoelectrically converted video signal, and a determination result. An optical disc deformation inspection system, comprising: a control signal transmitting unit for transmitting a corresponding signal; and a sequencer for inputting a control signal output from the control signal transmitting unit.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an optical disk deformation inspection system including an optical disk deformation inspection device according to one embodiment of the present invention.

As shown in FIG. 1, the optical disk deformation inspection system determines an optical disk deformation and outputs information on the quality of the optical disk, and discharges defective products based on the quality information of the optical disk inspection device. And a sequencer 14 such as a conveyor.

The optical disk inspection apparatus includes a screen 6 for projecting a chart image reflected on the surface of an optical disk substrate to be measured immediately after molding, and a two-dimensional CCD as photoelectric conversion means for inputting an image on the screen 6. Camera 1
2, the image captured by the two-dimensional CCD camera 12 is transferred, the shape of the transferred image is determined, and the area of the shape is calculated.
The image processing unit 11 which determines whether the optical disk substrate belongs to the normal pattern or the defective pattern prepared in advance, that is, the quality of the optical disk substrate, and the determination result of the image processing unit 11 are transferred. Sequencer 14 such as disk transport conveyor via I / O interface 13
And a main processor 10 for transferring the GO-NO signal from the main processor 10, and when the determination is GO, the disk substrate is normally transported, and when the determination is NO, the sequencer 14 that performs defective ejection is operated.

The main processor 10 can timely write the inspection result to the server 15 via the LAN and reflect it in quality control, production control and the like.

The image processing unit 11 determines the shape of the image transferred from the two-dimensional CCD camera 12, calculates the area of the shape, and determines whether the image belongs to a normal pattern or a defective pattern prepared in advance.

In order to project the reflected image of the chart on the screen 6, as shown in FIG. 5, an optical disk substrate conveyed on a conveying means 1 such as a conveyor, in this embodiment, one side of a DVD immediately after molding. A transmission image of a stripe filter 4 which is a chart illuminated by a parallel light source 3 is projected on an optical disk substrate 2 as a disk substrate, and a reflection image reflected on the upper surface of the optical disk substrate 2 is projected on a screen through a transparent plate 5. The transparent plate 5 may be omitted.

FIGS. 6A and 6B are diagrams for explaining a deformation pattern of the optical disk substrate when a stripe filter is used, wherein FIG. 6A is a diagram showing a pattern on the optical disk substrate in the case of a perfect plane, and FIG. (A) is a cross-sectional view of the optical disk substrate corresponding to the pattern, (C) is a diagram showing a pattern on the optical disk substrate in the case of the convex bowl shape, (D) is a cross-sectional view of the optical disk substrate corresponding to the pattern of (C),
(E) is a diagram showing a pattern on the optical disk substrate in the case of concave bowl deformation, (F) is a sectional view of the optical disk substrate corresponding to the pattern of (E), (G) is an optical disk substrate in the case of twist shape deformation The figure which shows the pattern of (H) is (G)
FIG. 3I is a cross-sectional view of an optical disk substrate corresponding to the pattern of FIG.

As shown in FIGS. 6A and 6B, when the reflection image 4a of the stripe filter 4 from the optical disk substrate 2 is parallel, the optical disk substrate 2 is completely flat.

As shown in FIGS. 6C and 6D, when the reflected image 4a of the stripe filter 4 from the optical disk substrate 2 spreads to the periphery, the optical disk substrate 2
Becomes a convex bowl-shaped deformation.

As shown in FIGS. 6 (E) and 6 (F), when the reflection image 4a of the stripe filter 4 from the optical disk substrate 2 becomes narrower toward the periphery, the optical disk substrate 2
Becomes concave bowl-shaped deformation.

As shown in FIGS. 6 (G) and 6 (H), when the reflection image 4a of the stripe filter 4 from the optical disk substrate 2 spreads toward the periphery and is asymmetrical, the optical disk substrate may be twisted. Become.

As shown in FIG. 6 (I), when the reflection image 4a of the stripe filter 4 from the optical disk substrate 2 is parallel at the periphery and at a different interval at the center, a partial deformation occurs. This partial deformation often occurs due to warpage of the optical disk substrate 2 at the position of the stack ring.

In this way, the deformation of the optical disk substrate is projected two-dimensionally on the screen in a pattern. According to the shape of the pattern, the disc can be identified as normal, twisted, or deformed into a bowl shape.

In the present system, the pattern is not viewed by the human eyes, but is image-processed by using a two-dimensional camera to thereby automate the inspection.

As described above, the two-dimensional CCD camera 12
The captured video is transferred to the image processing unit 11. The image processing unit 11 determines the shape of the image, calculates the area of the shape, and determines whether the image belongs to a prepared normal pattern or a defective pattern.

The result is transferred to the main processor 10, and the main processor 10 transfers the GO-NO signal to the sequencer 14 such as a disk conveyor via the I / O interface. The sequencer 14 normally conveys the disc when the judgment is GO, and performs the defective ejection when the judgment is NO. When appropriate, the main processor 10 writes the inspection result to the server 15 via the LAN, and reflects the result on quality control and production control.

FIG. 2 is a diagram showing an inspection algorithm, and FIG.
(A) is a figure which shows a to-be-inspected image, (B) is a figure which shows a reference image. In FIG. 3, e is an edge, and d is a distance between edges. 4A and 4B are diagrams showing a deformation pattern of the chart image, wherein FIG. 4A is a reference pattern, FIG. 4B is a bowl-shaped deformation pattern, FIG. 4C is a twist deformation pattern, and FIG. is there. In FIG. 4, KL indicates an inspection line, C indicates a chart image, and SL indicates a scanning line.

First, in step S1, an inspection image is captured by a two-dimensional CCD camera. Next, in step S2, n inspection lines KL are set. Next, in step S3, the edge e on the inspection line KL is detected. Next, in step S4, the distance d between edges is measured. Next, in step S5, the distance d between edges is compared with a reference value. Next, in step S6, it is determined whether or not it is within the allowable range. If it is within the allowable range, the process proceeds to step S7, and if it is outside the allowable range, the process proceeds to step S8. Next, in step S7, it is determined as a non-defective product and a GO signal is output. next,
In step S8, it is determined to be defective and a NO signal is output.

Next, the system algorithm will be described. First, as shown in FIG. 1, a setting is made so that the screen 6 of the optical disk deformation inspection device is reflected as much as possible to the viewing angle of the two-dimensional CCD camera 12 for performing image processing.

Next, one or more inspection lines are prepared at an arbitrary position in the image. The more inspection lines, the higher the inspection accuracy. Next, the inspection machine scans for an edge on the line. As for the edge condition, a threshold value is set for the gray value of the pixels constituting the inspection line, and the threshold value is equal to or less than the threshold value (dark).
Is determined to be an edge.

Next, the distance between edges is measured. This is possible by counting the pixels between the edges. Next, when the deformation of the optical disk is small, the number of edges (the number of horizontal stripes)
The distance between the edge and the edge is within an arbitrarily determined range. If the optical disk has a large deformation, the number of edges (the number of horizontal stripes) is different, or the distance between the edges is out of an arbitrarily determined range.

Next, the main processor of the inspection system sends the GO to the transport conveyor sequencer or the like based on the result.
-Output a NO signal.

According to the optical disk deformation inspection apparatus described above, the optical disk can be automatically inspected by image processing using a two-dimensional CCD camera, and the optical disk can be classified into non-defective products and defective products based on the inspection results. Also, the amount of deformation can be measured quantitatively.

In addition, a control device having an image processing device is provided, which makes it possible to automate inspection, separate and discharge non-defective / defective products, and make stable determinations based on fixed-valued pass / fail thresholds.

Further, the optical disk deformation inspection apparatus makes it easy to detect the deformation of the optical disk, which has been difficult in the past, before it becomes a product, and it is possible to inspect the optical disk without relying on the human eyes, thereby facilitating automation. In addition, the pass / fail threshold becomes clear, and there is no ambiguity unlike in the case of visually determining.

As described above, by capturing the reflected image 4a on the optical disk substrate 2 by the two-dimensional CCD camera, the deformation pattern of the optical disk substrate 2 can be measured and inspected objectively.

Since the deformation of the optical disk substrate 2 immediately after molding can be inspected, a spindle for rotating the disk is not required, the inspection near the spindle is also possible, and the optical disk substrate 2 including the vicinity of the easily deformable disk center hole can be inspected. There is an advantage that deformation of the entire surface can be inspected.

Further, since the chart image is projected on the surface of the optical disk substrate 2 and the inspection is performed by the reflected light from the surface of the optical disk substrate 2, there is no need to use the reflected light from the reflective film, and the deformation of the optical disk substrate 2 immediately after the molding is performed. Can be inspected.

Further, since the deformation of the optical disk substrate 2 immediately after the molding can be inspected, the optical disk substrate having a large deformation can be removed, and a post-process such as a vapor deposition process can be performed on the optical disk substrate having a large deformation. This has the advantage that the production efficiency is improved.

The present invention is not limited to the above embodiment. That is, various modifications can be made without departing from the gist of the present invention. For example, in the above embodiment, a two-dimensional CCD camera is used, but another two-dimensional sensor, a line sensor, a four-division sensor, or the like may be used. In addition to the optical disk substrate immediately after molding, the present invention can be applied to a disk on which a reflective film is deposited.

In the above embodiment, a stripe filter is used as a chart, but a mesh filter may be used instead of a stripe filter.

In the above embodiment, the case where the optical disk substrate 2 is inspected as one-sided disk substrate of the DVD has been described. However, other optical disk substrates such as a CD can be inspected. It can also be used for deformation inspection such as.

Further, since the present invention can be applied to any kind of disk holding, it can be easily connected to a production line.
Further, the inspection time is relatively short, which is suitable for mass production and the like. Moreover, it can be applied to any disc.

In the above embodiment, the image projected on the screen is taken in by the two-dimensional CCD camera for convenience of explanation.
The image may be directly captured by a three-dimensional CCD camera.

[0043]

As described above, according to the present invention, the deformation of the optical disk substrate can be inspected objectively and automatically, and the entire optical disk substrate can be inspected. It is not necessary to use the reflected light of the optical disk, it is possible to inspect the deformation of the optical disk substrate immediately after molding,
There is an advantage that an optical disk substrate having a large deformation can be removed, a post-process can be prevented from being performed on an optical disk substrate having a large deformation, and production efficiency is improved.

Further, since deformation of the optical disk substrate can be inspected without rotating the optical disk, there is an advantage that a spindle for rotating the disk is not required, and inspection near the spindle is also possible.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an optical disk deformation inspection system including an optical disk deformation inspection device according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating an inspection algorithm.

3A is a diagram illustrating an image to be inspected, and FIG. 3B is a diagram illustrating a reference image.

FIG. 4 is a diagram showing a deformation pattern of a chart image;
(A) is a reference pattern, (B) is a bowl-shaped deformation pattern, (C) is a twist deformation pattern, and (D) is a partial deformation pattern.

FIG. 5 is a view for explaining a screen provided in the optical disk deformation inspection device according to one embodiment of the present invention.

FIG. 6 is a diagram for explaining a deformation pattern of an optical disk substrate when a stripe filter is used;
(A) is a diagram showing a pattern on the optical disk substrate in the case of a perfect plane, (B) is a cross-sectional view of the optical disk substrate corresponding to the pattern of (A), (C) is a diagram on the optical disk substrate in the case of a convexly-curved deformation. (D) is a cross-sectional view of the optical disk substrate corresponding to the pattern of (C), (E) is a diagram showing a pattern on the optical disk substrate in the case of the concave bowl shape, (F) is a diagram of (E). Sectional view of the optical disc substrate corresponding to the pattern, (G) is a view showing the pattern on the optical disc substrate in the case of the torsional deformation, (H) is a sectional view of the optical disc substrate corresponding to the pattern of (G), and (I) is a part. FIG. 4 is a diagram showing a pattern on an optical disk substrate in the case of deformation.

[Explanation of symbols]

 2 optical disk substrate 10 main processor 11 image processing unit 12 two-dimensional CCD camera 13 interface 14 sequencer

Claims (2)

[Claims] 1. A photoelectric conversion unit for capturing a chart image reflected on an optical disk substrate, a determination unit for determining the quality of the optical disk substrate based on a photoelectrically converted video signal,
An optical disk deformation inspection device, comprising: a control signal transmitting unit that transmits a signal corresponding to a determination result. 2. A photoelectric conversion means for capturing a chart image reflected by an optical disk substrate, a determination means for determining the quality of an optical disk substrate based on a photoelectrically converted video signal, and a control for transmitting a signal corresponding to the determination result Signal sending means;
An optical disk deformation inspection system, comprising: a sequencer for inputting a control signal output from the control signal transmitting means.