JP2003178493A - Inspection device for optical disk - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inspection device for an optical disk, which inspects the printed face of a label 111 using transparent or fluorescent ink of an optical disk such as a CD, inspects the state of a protective coating film 113, or inspects the lamination and adhesion state of a laminated DVD or the like. <P>SOLUTION: The inspection device 200 for the optical disk is equipped with an LED illumination unit 4 to illuminate the surface of an optical disk to be inspected with near UV rays from a near UV LED 8, near IR rays from a near IR LED 9, and visible rays from a visible ray LED 10 at a time, with a beam splitter 3 to spectrally divide the reflected light of the rays from the optical disk 110 into near UV rays and visible rays from near IR rays, with a near IR camera 1 to photograph the visible light and the near IR rays spectrally divided by the beam splitter 3, and with a near UV camera 2 to photograph the near UV rays spectrally divided by the beam splitter 3. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disc inspection device for inspecting a finished state of an optical disc.
For more details, compact discs (hereinafter referred to as CDs)
For example, the present invention relates to an optical disc inspection device that comprehensively inspects defects on the printing surface, inspection for the presence or absence of a protective coating film, and inspection of the bonding state of bonded disks.

2. Description of the Related Art Conventionally, as an inspection device for inspecting an optical disk 110, there is an inspection device 100 as shown in FIG. The inspection apparatus 100 includes an LED illumination unit 120 that illuminates the optical disc 110 with illumination light, and an area camera 1 that captures the illumination light reflected from the optical disc 110.
It is composed of thirty. The optical disc 110 is
With the surface to be inspected facing upward, the area camera 130 is mounted on an inspection table (not shown) with its center aligned with the optical axis X. L
The ED lighting unit 120 is arranged with the light emitting portion of the LED facing the surface to be inspected of the optical disc 110 (in the figure), between the optical disc 110 and the area camera 130, centered on the optical axis X, and reflected at the central portion. It has a ring shape with an opening through which light passes. In the area camera 130, the portion to be inspected of the optical disc 110 is a camera lens (not shown).
Is arranged at the focal length of. The operation of the conventional optical disc inspection apparatus 100 will be described. Illumination light emitted (incident) from the LED illumination unit 120 is reflected by the surface to be inspected of the optical disc 110, and an image of the surface to be inspected is obtained by the area camera 130. The image is formed on the lens (not shown). The state of the surface to be inspected of the optical disk 110 is inspected by taking an image of this surface to be inspected by the area camera 130 and processing the captured image.

Generally, as shown in FIG. 3, a manufacturer's name, song title, performer's name, etc. are printed on the mirror surface of the optical disc 110 such as a CD for displaying recorded contents. Has been done. (Hereinafter, referred to as a label.) As a technique for inspecting whether or not the printing state of the label 111 is defective, the label 111 is illuminated by the LED illumination unit 120, and the reflected light from the label 111 is applied to the area camera 130. Image input, and the reference image obtained from the label 111 that has been printed without problems in advance,
A method of detecting a defect of the label 111 by comparing the image to be inspected obtained from the label of the disc to be inspected 110 has been used. Many of the defects that occur on the label 111 are color spots that occur when color inks are overprinted (overprinting), ink fading, and blurring, bleeding, and chipping of characters and figures. Such a defect could be dealt with by a conventional visible area camera. However, these days, disc makers are using label 111
In addition, transparent or semi-transparent ink or fluorescent ink is used to differentiate the ink. Since this transparent ink or fluorescent ink is transparent or semi-transparent, it is not possible to determine the presence or absence of ink and the printing state with a conventional area camera in the visible light region. Further, when the area camera 130 photographs the label 111, the label is photographed under illumination with a constant intensity and the photographed image is inspected. Therefore, the defect detection capability varies depending on the ink color, and it is not possible to secure a stable defect detection capability on the entire label surface. In particular, in a label (printing) in which two colors of white and black are mixed at the same time, if the optical system is set for white, the expected defect detection ability can be obtained in the white portion, but the expected defect detection ability can be obtained in the black portion. Can't get In other words, the black portion has insufficient illuminance and becomes a dark imaged image, and the printing defect cannot be detected. On the contrary, if the optical system is set for black, the white portion cannot obtain the expected detection ability. In other words, the white part has too much illumination,
Halation occurs, a captured image cannot be obtained, and printing defects cannot be detected. For this reason, an optical system was first set for the camera to capture an image, and then an image was captured after resetting the optical system for black. That is, in the case of a white type, the illuminance was lowered, and in the case of a black type, the illuminance was increased to inspect. Further, as shown in FIG. 4, an optical disc 110 such as a CD has a transparent protective coating film on its upper surface in order to prevent oxidation of the reflection film 112 because aluminum is vapor-deposited on the molded signal forming surface as a reflection film 112. 113 is applied. Conventionally, it has been difficult to determine whether or not the protective coat film 113 is uniformly applied, by inspecting with the area camera 130 in the visible light region because the protective coat film 113 is transparent.
In addition, as shown in FIGS. 5 and 6, a DVD 110 that has two discs attached in recent years to double the amount of information to be stored
a is being developed. In this DVD 110a, two disks 114a and 114b are made of an adhesive material 1 such as UV resin.
It is attached by 15. In order to inspect the bonded state of the disc, it is determined whether or not the adhesive state is good by inspecting whether or not the adhesive material 115 is uniformly adhered to the transparent portion 117 on the inner peripheral side of the recording layer 116. . Figure 5
A through hole 11 is formed in the center as shown in FIG.
8 and the recording layer 1 is concentric with the through hole 118 on the outer peripheral side.
16, the inner circumference of which is a transparent portion 117 made of polycarbonate resin. As shown in FIG. 6, the two disks 114a and 114b are attached to each other with an adhesive material 115 such as UV resin. Through hole 1
18, a groove 119 is formed concentrically with the adhesive material 115.
The groove 119 prevents the groove from protruding to the inner circumference from the groove 119. However, when the adhesive material 115 is adhered, the adhesive material 115 is excessive or insufficient, so that the adhesive material 115 protrudes from the groove 119 (A), or the adhesive material 115 becomes unfilled and bubbles (B).
Occurs. The disk 114 is inspected for the protrusion (A) and air bubbles (B) of the adhesive 115 on the transparent portion 117.
Since a, 114b and the adhesive 115 are transparent, it is difficult to inspect with an area camera in the visible light region. The present invention has been made in view of such circumstances, and reliably captures an image in the optical disc 110 in which transparent ink or fluorescent ink is used for the label, or in which white and black print colors are mixed. An object of the present invention is to provide an optical disk inspection device capable of detecting a printing defect and surely inspecting the presence or absence of application of a protective coating film or the application state. Also, D
An object of the present invention is to provide an optical disc inspection device capable of surely inspecting the bonding state of a bonded disc such as the VD 110a.

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides an optical disc LE having a printing surface.
In the printing surface inspection apparatus that detects a defect on the printing surface by irradiating light with D illumination, capturing the reflected light from the optical disk with the camera, and recognizing the image captured by the camera, the LED illumination and the camera are It is characterized in that it corresponds to the near-ultraviolet region and visible light and near-infrared region. Another aspect of the present invention is to print an optical disc having a printing surface by illuminating light with LED illumination, capturing reflected light from the optical disc with a camera, and recognizing an image captured by the camera. In the printing surface inspection device that detects defects of
The LED illumination for irradiating the optical disc with near-ultraviolet rays, visible light, and near-infrared rays, which is arranged on the optical disc coaxially with the axis of the optical disc, a prism arranged on the LED illumination, A near-infrared region compatible camera, which is arranged above, for observing visible light and near-infrared light is arranged in order, and is provided with a near-ultraviolet region compatible camera that faces the prism and images near-ultraviolet light from the prism. It is characterized by. Further, the LED illumination is characterized in that a visible light region compatible LED, a near infrared region compatible LED, and a near ultraviolet region compatible LED are evenly provided on a substrate.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram of an optical disc inspection apparatus 200 according to an embodiment of the present invention,
FIG. 2 is a schematic explanatory diagram illustrating the configuration of the LED illumination of the present invention. FIG. 1 shows an optical disc inspection apparatus 200 of the present invention.
It is a schematic block diagram of one Example. The optical disc inspection device 200 includes a near infrared region compatible camera 1, a near ultraviolet region compatible camera 2, a beam splitter 3, and an LED illumination unit 4. Near infrared region compatible camera 1
Is a near-infrared camera compatible with light having a wavelength from the visible light region to the near-infrared region, and the optical axis X is the optical disk 11
It is fixed so that it is coaxial with 0. The beam splitter 3 is arranged between the near infrared ray region compatible camera 1 and the optical disk 110, and is arranged coaxially with the optical axis X. The beam splitter 3 is fixed so that the refraction angle (in the figure) forms an angle of 45 ° with the optical axis X, and the beam splitter 3 causes the reflected light from the optical disk 110 to
Spectral so that light with a wavelength from the visible light region goes straight in the optical axis X direction, and light with a wavelength in the near ultraviolet region goes straight in the optical axis L direction forming 45 ° with the optical axis X. To be done. The near-ultraviolet region compatible camera 2 faces the beam splitter 3 and its optical axis is arranged coaxially with the optical axis L, and photographs the light having a wavelength in the near-ultraviolet region dispersed from the beam splitter 3 in the optical axis L direction. . As shown in FIG. 2, the LED lighting unit 4 includes an LED assembly 5 and a frame body 6 that fixes the LED assembly 5. The frame 6 has a ring shape having an opening 6a toward the lower surface (in the drawing), and has a ring-shaped opening 6b formed in the center with an inner diameter sufficient for the reflected light from the optical disk 110 to pass through. The frame 6
An LED assembly 5 having a large number of LEDs mounted therein is fixed with the light emitting surface of each LED facing downward (in the drawing). The LED assembly 5 is fixed inside the frame 6, has the same ring shape as the frame, and has an LED outer diameter sufficient to illuminate the optical disk 110. LED assembly 5
Is near UV (ultraviolet ray)
s) LED 8 and near infrared ray (IR: infrar)
ed rays) area compatible LED 9 and visible light compatible LED
10 is provided side by side on the substrate 7 so that a uniform illuminance distribution can be obtained. The visible light LED 10 is the red LED 10
a, white LED 10b, blue LED 10c, yellow LED
A plurality of 10d and green LEDs 10e are prepared, and they are provided side by side so as to be uniformly distributed on the substrate 7. These red LED 10a, white LED 10b, blue LE
The D10c, the yellow LED 10d, and the green LED 10e are simultaneously turned on by a power source (not shown). Next, the operation of the optical disc inspection apparatus 200 having the above-mentioned configuration will be described. As shown in FIG. 1, all the LEDs 8, 9, 10 are turned on all at once in order to inspect the optical disc 110. Near UV rays are radiated from near UV LEDs 8, near infrared rays are radiated from near infrared LEDs 9, and visible rays (red light, white light, blue light, yellow light) are emitted from visible light LEDs 10, which are evenly provided in the LED assembly 5. Light, green light) is emitted all at once toward the optical disk 110 (epi-illumination),
The entire surface to be inspected of the optical disk 110 is irradiated. This light is reflected upward from the label surface 111 of the optical disk 110 (in the figure) and enters the beam splitter 3. As for the reflected light that has entered the beam splitter 3, visible light and light having a wavelength in the near-infrared region are dispersed in the optical axis X direction,
Light having a wavelength in the near-ultraviolet region is dispersed in the optical axis L direction. X
Light from the visible light region to the near-infrared region, which is spectrally dispersed in the axial direction, enters the near-infrared region compatible camera 1, and light in the near-ultraviolet region wavelength that is spectrally dispersed in the optical axis L direction corresponds to the near-ultraviolet region. It is incident on the camera 2. Then, the near-infrared region compatible camera 1 captures an image of light having a wavelength from the visible light region to the near-infrared region, processes the captured image, and inspects the optical disc 110 to be inspected. Further, the near-ultraviolet region compatible camera 2 captures an image with a wavelength in the near-ultraviolet region, the captured image is image-processed, and the optical disc 110 to be inspected is inspected. In the case where the optical disc inspection apparatus 200 of the present invention inspects the print surface of the label 111 such as a CD for defects, the label 111 is printed with transparent or translucent ink, fluorescent ink, or the like. In the case of using, the near-ultraviolet LED 10 of the LED lighting unit 4 emits light having a wavelength in the near-ultraviolet region to the surface of the label 111 of the CD, and the reflected light is split by the beam splitter 3 into light having a wavelength in the near-ultraviolet region. By photographing with the near-ultraviolet region compatible camera 2, an image in which there is a clear difference between a portion with ink and a portion without ink is obtained. By processing this image, the label 111 using transparent ink or fluorescent ink is obtained. It is possible to inspect the printed surface for defects. Also, label 111
If white and black are mixed on the printed surface of the
Is emitted to the surface of the label 111 with an illuminance that does not cause halation in the white part, and the reflected light is split into light of wavelengths in the visible light region and the near infrared region by the beam splitter 3, and the near infrared region compatible camera 1 is used. Take a picture. That is, although black has a dark illuminance in the visible light region, it can be clearly photographed with light having a wavelength in the near infrared region. By processing this captured image, halation does not occur in white, and black is also black. A clear image can be captured, and defects on the printing surface of the label 111 can be detected. Further, the optical disc inspection apparatus 200 of the present invention
In, the following inspection of the optical disc 110 can be performed. 1. As shown in FIG. 4, it is possible to inspect whether the optical disc 110 such as a CD is coated with the protective coating film 113 or whether the protective coating film 113 is uniformly coated. That is,
The near-ultraviolet LED 8 of the LED lighting unit 4 emits light having a wavelength in the near-ultraviolet region to the surface of the protective coat film 113 of the CD 110, and the reflected light is split into light having a wavelength in the near-ultraviolet region by the beam splitter 3, and the near-ultraviolet region is irradiated. Compatible camera 1
By taking a picture at
Alternatively, the coating state can be inspected. 2. As shown in FIGS. 5 and 6, it is possible to inspect the state of the adhesive material 115 of the DVD 110a in which two sheets of polycarbonate resin are bonded. That is, the transparent portion 117 inside the recording layer 116 of the DVD 110 a is irradiated with light having a wavelength in the near-ultraviolet region emitted by the near-ultraviolet LED 8 of the LED lighting unit 4, and the reflected light is reflected by the beam splitter 3 in the near-ultraviolet region. By separating the light into wavelengths and photographing it with the near-ultraviolet region compatible camera 2, defects such as protrusion (A) inside the groove 119 of the adhesive 115 and bubbles (B) generated inside the adhesive are detected. be able to. In the above-described embodiment of the present invention, the near-ultraviolet LED 8, the near-infrared LED 9 and the visible light LED 1 of the LED lighting unit 4 are used.
Although all 0s are lit simultaneously, it may be more effective to illuminate them individually depending on the surface to be inspected. For example, since the inspection of the presence or absence of the protective coat film 113 and the adhesion state of the bonded DVD 110a are not effective with light having a wavelength in the visible light or near infrared region, only the near ultraviolet LED 8 may be irradiated alone.
However, the print surface state inspection of the label 111 of the CD 110 and the presence / absence inspection of the protective coat film are often inspected at the same time, so it is more efficient to inspect them by turning them on all at once. However, in the case of the laminated DVD 110a,
Since the adhesion state inspection and the presence / absence inspection of the protective coat film 113 are often performed after the discs are bonded together and before the printing of the label 111, the near-ultraviolet LED 1 is used.
After turning on 0, the adhesion state and the presence or absence of the protective coat film are inspected by the near-ultraviolet region compatible camera 1, and after the printing of the label is completed, the printed surface is inspected and the visible light LED 12 and the near infrared LED 11 are turned on. Then, it may be inspected by photographing with a near infrared compatible camera. Needless to say, all LEDs
8、9、10 、 Adhesion condition and protective coat film presence inspection,
Then, it may be turned on every time the label printing surface is inspected, or may be turned on continuously. Further, it is possible to detect the deformation of the surface of the inspection object without hindering the conventional inspection method using visible light. In addition, it is possible to inspect the internal state of the inspection object. That is, the states of the protective coat film and the bonding adhesive can be inspected without disturbing the conventional label printing inspection method using visible light.

As described above, according to the optical disc printing inspection apparatus of the present invention, the LED illumination and the camera are adapted to correspond to the light having the wavelengths in the near ultraviolet region, the visible light region and the near infrared region. In addition, it is possible to reliably capture images and perform defect inspections on optical disc labels that use transparent ink or fluorescent ink, or those that have a mixture of white and black print colors. The presence or absence or the applied state can be surely inspected. In addition, the bonded state of a bonded disc such as a DVD can be surely inspected.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an optical disk print state inspection apparatus 200 according to an embodiment of the present invention.

2 is a cross-sectional view illustrating the LED lighting unit 4 of FIG. 1 and an enlarged view of a portion D of an LED assembly 5. FIG.

FIG. 3 is a configuration diagram of an optical disc inspection apparatus 100 which is an example of a conventional optical disc.

FIG. 4 is a cross-sectional view illustrating a protective coat film 113 of the optical disc 110.

FIG. 5 is a plan view illustrating a bonded DVD 110a.

FIG. 6 is a sectional view taken along the line C-C ′ of FIG.

[Explanation of symbols]

111 label (print side) 8, 9, 10 CD (optical disc) 111a DVD (optical disc) 4 LED lighting unit (LED lighting) 1 Near infrared region compatible camera (camera) 2 Near UV region compatible camera (camera) 200 Optical disc inspection system 3 Beam splitter (prism) 1 Near infrared camera 2 Near UV range camera 10 LED for visible light range 10a Red (visible light area LED) 10b White (visible light area LED) 10c Blue (visible light range LED) 10d yellow (visible light area LED) 10e Green (visible light area LED) 8 Near-UV region compatible LED 9 Near infrared LED

Claims (3)

[Claims] 1. A defect on the printing surface by irradiating an optical disk having a printing surface with light by LED illumination, capturing the reflected light from the optical disk with a camera, and recognizing the image captured by the camera. In the printing surface inspection device for detecting the above, the LED illumination and the camera correspond to a near ultraviolet region and visible light and near infrared regions. 2. A defect on the printing surface by irradiating an optical disk having a printing surface with light by LED illumination, capturing the reflected light from the optical disk with a camera, and recognizing the image captured by the camera. In the printing surface inspection device for detecting, coaxial with the axis of the optical disc,
LED illumination for irradiating the optical disc with near-ultraviolet rays, visible light, and near-infrared rays, disposed on the optical disc, a prism disposed on the LED illumination, and disposed on the prism Further, a near-infrared region compatible camera for imaging visible light and near-infrared light is arranged in order, and the near-ultraviolet region compatible camera for imaging the near-ultraviolet light from the prism is provided so as to face the prism. Optical disc inspection device. 3. The LED lighting is characterized in that a visible light region compatible LED, a near infrared region compatible LED and a near ultraviolet region compatible LED are evenly provided on a substrate. Optical disc inspection device.