JP2004214147A - Inspection method and inspection device for spacer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inspection method and an inspection device capable of easily and accurately inspecting the arrangement state of spacers. <P>SOLUTION: In inspecting the arrangement state of the plurality of spacers arranged on a setting face, an inspection light is radiated tward the spacers 30a by a light source in a direction slanted by 0 to 20 degrees against the setting face, and scattered light scattered by the spacers is imaged by an imaging device 54 fitted against the setting face to inspect the arrangement state of the spacer by an image obtained. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a spacer inspection method and an inspection apparatus for inspecting an arrangement state of a spacer used in an image display device.
[0002]
[Prior art]
In recent years, a field emission display (FED), a plasma display (PDP), and the like have been known as image display devices. As one type of FED, a surface conduction electron-emitting device (hereinafter, referred to as SED) has been developed. The SED includes a front substrate and a rear substrate that are opposed to each other with a predetermined gap. These substrates have their peripheral edges joined to each other via rectangular frame-shaped side walls, and constitute a vacuum envelope by evacuating the inside. Phosphor layers of three colors are formed on the inner surface of the front substrate, and a number of electron-emitting devices corresponding to each pixel are arranged on the inner surface of the rear substrate as electron emission sources for exciting the phosphor layers.
[0003]
A plate-like grid is provided between the front substrate and the rear substrate. A large number of beam passage holes are formed in the grid in a positional relationship aligned with the electron-emitting devices. Further, between the front substrate and the rear substrate, a plurality of columnar spacers for maintaining a gap between the front substrate and the rear substrate are provided.
[0004]
In such an SED, an electron beam emitted from the electron-emitting device impinges on a desired phosphor layer through a corresponding beam passage hole of the grid. As a result, the phosphor is excited to emit light, and an image is displayed.
[0005]
In the SED, a high degree of vacuum is required for the space closed by the front substrate, the rear substrate, and the side wall, that is, the inside of the vacuum envelope. When the degree of vacuum is low, the life of the electron-emitting device and, consequently, the life of the device are reduced. Further, since a vacuum is applied between the front substrate and the rear substrate, atmospheric pressure acts on the front substrate and the rear substrate. Therefore, a number of plate-shaped or columnar spacers are arranged between the front substrate and the rear substrate to prevent destruction of the substrate due to an atmospheric pressure load, and to maintain a constant gap between the substrates. I have.
In order for a plurality of spacers to effectively perform the above-described function, it is necessary that a desired number of these spacers are provided at predetermined positions. If the spacers are not properly arranged at the specified intervals, the atmospheric pressure may cause damage to the vacuum envelope, or the front and rear substrates may be distorted, preventing normal image display. There is. Therefore, it is desirable to check whether the spacers are properly arranged in the SED manufacturing process.
[0006]
As a method of inspecting such a spacer, a human inspection with the naked eye or a method using an imaging device such as a CCD camera can be considered. For example, in Patent Document 1, in a PDP manufacturing process, a predetermined width region is photographed by a CCD licensor camera or the like from a direction substantially perpendicular to the rear substrate, and barriers on the rear substrate and defects between the barriers are detected based on photographed image data. A method for detecting is disclosed.
[0007]
[Patent Document 1]
Japanese Patent Application Laid-Open No. 2000-162139
[Problems to be solved by the invention]
However, since a large number of spacers are provided, an inspection using a human method such as the naked eye requires a great deal of labor. Also, in inspections using an imaging device, coaxial incident illumination, ring illumination, etc., the spacers are minute compared to the area of the front substrate and the rear substrate, so that the pattern on the installation surface on which the spacers are provided, dust, etc. It is difficult to distinguish between the spacer and the spacer for accurate inspection.
[0009]
The present invention has been made in view of the above points, and an object of the present invention is to provide a spacer inspection method and an inspection apparatus capable of easily and accurately inspecting a spacer arrangement state.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, a method for inspecting a spacer according to the present invention is directed to a method for inspecting the arrangement of a plurality of spacers provided on an installation surface, wherein the spacer is inclined at 0 to 20 degrees with respect to the installation surface. The spacer is irradiated with inspection light from a direction, scattered light scattered by the spacer is detected, and the arrangement state of the spacer is inspected based on the detected scattered light.
[0011]
Further, the spacer inspection apparatus according to the present invention is a spacer inspection apparatus for inspecting an arrangement state of a plurality of spacers provided on an installation surface, wherein the spacer is inspected from a direction inclined from 0 to 20 degrees with respect to the installation surface. A light source that irradiates inspection light, an imaging device that is provided to face the installation surface, and captures scattered light scattered by the spacer, and an image processing device that processes an image of the spacer captured by the imaging device And, it is characterized by having.
[0012]
According to the inspection apparatus and the inspection apparatus method for the spacer configured as described above, the spacer is irradiated with the inspection light from a direction inclined from 0 to 20 degrees with respect to the installation surface. At this time, since the spacer to be inspected protrudes from the installation surface, the detection light is scattered by the spacer, and the portion of the spacer is illuminated brighter than its surroundings. Then, by detecting the scattered light scattered by the spacer, the spacer can be accurately inspected by distinguishing it from the pattern or dust on the installation surface. Thereby, the arrangement state of the spacer can be easily and accurately inspected, and the human burden can be reduced.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a method and an apparatus for inspecting a spacer according to an embodiment of the present invention will be described in detail with reference to the drawings. First, an SED will be described as an example of an image display device including a spacer to be inspected by the inspection method and the inspection device.
[0014]
As shown in FIGS. 1 to 3, the SED includes a front substrate 10 and a rear substrate 12 each formed of a rectangular glass plate, and these substrates are opposed to each other with a gap of about 1 to 2 mm. The front substrate 10 and the rear substrate 12 are joined to each other via a rectangular side wall 14 made of glass to form a flat vacuum envelope 15 having a vacuum inside.
[0015]
On an inner surface of the front substrate 10, a phosphor screen 16 functioning as an image display surface is formed. The phosphor screen 16 is configured by arranging red, blue, and green phosphor layers R, G, and B, and a light shielding layer 11, and these phosphor layers are formed in a stripe shape or a dot shape. A metal back 17 made of aluminum or the like is formed on the phosphor screen 16.
[0016]
On the inner surface of the rear substrate 12, a number of surface conduction electron-emitting devices 18 each emitting an electron beam are provided as electron sources for exciting the phosphor layer of the phosphor screen 16. These electron-emitting devices 18 are arranged in a plurality of columns and a plurality of rows corresponding to each pixel. Each of the electron-emitting devices 18 includes an electron-emitting portion (not shown), a pair of device electrodes for applying a voltage to the electron-emitting portion, and the like. On the inner surface of the back substrate 12, a number of wirings 21 for supplying a potential to the electron-emitting devices 18 are provided in a matrix shape, and the ends of the wirings 21 are drawn out of the vacuum envelope 15.
[0017]
The side wall 14 functioning as a joining member is sealed to the peripheral portion of the front substrate 10 and the peripheral portion of the rear substrate 12 by a sealing material 20 such as a low-melting glass, a low-melting metal, or the like. are doing.
[0018]
As shown in FIGS. 2 to 4, the SED includes a spacer structure 22 provided between the front substrate 10 and the rear substrate 12. In the present embodiment, the spacer structure 22 is composed of a grid 24 made of a rectangular metal plate, and a number of columnar spacers integrally provided on both sides of the grid.
[0019]
More specifically, the grid 24 has a first surface 24a facing the inner surface of the front substrate 10 and a second surface 24b facing the inner surface of the rear substrate 12, and is arranged in parallel with these substrates. A large number of electron beam passage holes 26 are formed in the grid 24 by etching or the like. The electron beam passage holes 26 are arranged to face the electron-emitting devices 18, respectively, and transmit the electron beams emitted from the electron-emitting devices.
[0020]
The grid 24 is formed of, for example, an iron-nickel-based metal plate to a thickness of 0.1 to 0.25 mm, and has on its surface an oxide film made of an element constituting the metal plate, for example, Fe ₃ O. ₄ , an oxide film made of NiFe ₂ O ₄ is formed.
[0021]
On the first surface 24a of the grid 24 functioning as an installation surface, a first spacer 30a is integrally erected and is located between the adjacent electron beam passage holes 26. The extended end of the first spacer 30a is in contact with the inner surface of the front substrate 10 via the metal back 17 and the light shielding layer 11 of the phosphor screen 16. A second spacer 30b is integrally provided on the second surface 24b of the grid 24 functioning as another installation surface, and is located between the adjacent electron beam passage holes 26. The extending end of the second spacer 30b is in contact with the inner surface of the back substrate 12. Here, the extending end of each second spacer 30 b is located on the wiring 21 provided on the inner surface of the rear substrate 12.
[0022]
The first and second spacers 30a and 30b are arranged at predetermined intervals, and are provided in a predetermined array over the entire area of each surface of the grid 24. The first and second spacers 30a and 30b are located in alignment with each other with the grid 24 interposed therebetween, and are formed integrally with the grid 24. Each of the first and second spacers 30a and 30b is formed in a tapered shape having a smaller diameter from the grid 24 side toward the extending end. The first and second spacers 30a and 30b are made of, for example, glass as a main component.
[0023]
The spacer structure 22 configured as described above is disposed between the front substrate 10 and the rear substrate 12. The first and second spacers 30a and 30b contact the inner surfaces of the front substrate 10 and the rear substrate 12 to support the atmospheric pressure load acting on these substrates and maintain the distance between the substrates at a predetermined value. are doing.
[0024]
The SED includes a voltage supply unit (not shown) that applies a voltage to the grid 24 and the metal back 17 of the front substrate 10. For example, a voltage of 12 kV is applied to the grid 24 and a voltage of 10 kV is applied to the metal back 17.
[0025]
In the SED, when displaying an image, the electron emission element 18 is driven via the wiring 21 to emit an electron beam from an arbitrary electron emission element, and an anode voltage is applied to the phosphor screen 16 and the metal back 17. Apply. The electron beam emitted from the electron-emitting device 18 is accelerated by the anode voltage, passes through the electron beam passage hole 26 of the grid 24, and collides with the phosphor screen 16. Thereby, the phosphor layer of the phosphor screen 16 is excited to emit light, and an image is displayed.
[0026]
Next, a description will be given of a spacer inspection method and an inspection apparatus for inspecting the arrangement state of the spacers constituting the spacer structure 22 in the process of manufacturing the SED configured as described above.
As shown in FIGS. 5 and 6, the inspection device for the spacer includes a support base 50 that supports the spacer assembly 22 on which the first and second spacers 30 a and 30 b are formed, and an illumination device 52 that irradiates the spacer assembly with inspection light. , An image capturing device 54 for capturing an image of the spacer structure, and an image processing device 56 for performing image processing on an image captured by the image capturing device.
[0027]
At the time of inspection, the spacer structure 22 is supported on the support base 50 with one surface of the grid 24 positioned horizontally. The illuminating device 52 has an elongated linear light source 58 provided horizontally and a case 60 covering the linear light source. In the case 60, a slit 62 extending horizontally and facing the linear light source 58 is formed. The illuminating device 52 is arranged on the side of the spacer structure 22 supported by the support base 50 and is arranged so as to irradiate the surface of the spacer structure 22 with the inspection light at the irradiation angle θ. . The irradiation angle θ is set to 0 to 20 degrees. The irradiation angle θ is preferably closer to 0 degrees, and the illumination device 52 irradiates the inspection light toward the spacers of the spacer structure from a direction substantially parallel to the surface of the spacer structure 22.
[0028]
The imaging device 54 is configured by, for example, a CCD camera, is disposed above the spacer structure 22, and faces the surface of the spacer structure. As described later, the image processing device 56 includes a RAM 61 storing various data including reference data indicating a correct arrangement state of the spacer, and a CPU 63 configuring a data comparison unit, a determination unit, and a control unit. I have. The CPU 63 is connected to the imaging device 54 via the interface 64, and is also connected to the monitor 66 via the output unit 67 and the interface 65.
[0029]
For example, when inspecting the arrangement state of the spacers 30 a of the spacer structure 22, the spacer structure is placed on the support 50 with the spacer 30 a facing up. Subsequently, the illumination device 52 irradiates inspection light to the spacer 30a from a direction inclined by 0 to 20 degrees with respect to the upper surface of the spacer structure 22. At this time, the inspection light applied to the spacer 30a is scattered by the spacer and becomes scattered light.
[0030]
In this state, the scattered light from the spacer 30a is detected, and the arrangement state of the spacer is inspected based on the detected scattered light. Here, the upper surface of the spacer structure 22 including the spacer 30a is imaged by the imaging device 54. The image of the spacer 30a captured by the imaging device 54 is sent to the image processing device 56 as image data, and stored in the RAM 61. The CPU 63 compares the reference data stored in the RAM 61 as a data storage unit with the image data input from the imaging device 54, and determines whether the arrangement state of the spacer 30a is correct. Then, the CPU 63 sends the image of the spacer 30a captured by the image capturing device 54 and the above-described determination result to the monitor 66 and displays it. Thereby, the operator can confirm the arrangement state of the spacers from the image of the spacer 30a displayed on the monitor or the determination result. The data displayed on the monitor 66 may be either the image of the spacer 30a or the determination result.
[0031]
After inspecting the arrangement state of the spacers 30a as described above, the spacer structure 22 is turned over and placed on the support base 50, and the arrangement state of the spacers 30b is inspected by the same steps as described above.
[0032]
When the number of spacers to be inspected is large, a method may be adopted in which the installation surface of the spacers is divided into a plurality of regions and inspected. As shown in FIG. 7, for example, when inspecting the spacer of the spacer structure 22 used for a 30-inch SED, the surface of the spacer structure is divided into 16 regions 60a in the longitudinal direction and 5 regions in the width direction. In a state where the inspection light is emitted from the illumination device 52 to the spacer 30a of the spacer structure 22, the imaging device 54 sequentially captures an image of each region 60a. Subsequently, the obtained image data for each area is synthesized by the image processing device 56, and the synthesized image data thus synthesized is compared with the reference data to determine the arrangement state of the spacer. Then, at least one of the obtained composite image and the determination result is sent to the monitor 66 and displayed. Thereby, the operator can confirm the arrangement state of the spacers from the image of the spacer 30a displayed on the monitor or the determination result.
[0033]
According to the inspection method and the inspection apparatus for the spacer configured as described above, the inspection light is applied to the spacer from a direction inclined by 0 to 20 degrees with respect to the installation surface. Thereby, the reflected light reflected on the installation surface and reaching the imaging device 54 can be reduced as much as possible. Further, since the spacer to be inspected projects from the installation surface, the detection light is scattered by the spacer, and the portion of the spacer shines brighter than its surroundings. Then, by detecting the scattered light scattered by the spacer, the spacer can be accurately inspected by distinguishing it from the pattern or dust on the installation surface. Thereby, the arrangement state of the spacer can be easily and accurately inspected, and the human burden can be reduced. As a result, it is possible to efficiently perform the inspection process of the spacer and improve the manufacturing efficiency of the SED. At the same time, it is possible to improve the yield of SEDs manufactured using spacers.
[0034]
The present invention is not limited to the above-described embodiment, and can be variously modified in an implementation stage without departing from the gist of the invention. Further, the embodiments include inventions at various stages, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent elements. For example, even if some components are deleted from all the components shown in the embodiments, the problem described in the column of the problem to be solved by the invention can be solved and described in the column of the effect of the invention. When the effect is obtained, a configuration from which this configuration requirement is deleted can be extracted as an invention.
[0035]
For example, in the above-described embodiment, the captured image may be displayed, the image may be observed manually, and the arrangement state of the spacer may be inspected. Further, the inspection method of the present invention is not limited to the above-described SED, but can be applied to the inspection of a spacer used in another image display device such as an FED or a PDP. The spacer is not limited to the columnar shape, and a plate-like spacer can be inspected in the same manner as described above.
[0036]
In the above-described embodiment, an example in which the spacer provided on the grid is inspected has been described. However, the present invention is not limited to this, and can be applied to the inspection of the spacer provided on another installation surface such as a substrate. It is. The light source is not limited to a linear light source, and can be variously selected as needed. Similarly, the imaging device is not limited to the CCD camera and can be appropriately selected.
[0037]
【The invention's effect】
As described above in detail, according to the present invention, it is possible to provide a spacer inspection method and an inspection apparatus capable of easily and accurately inspecting a spacer arrangement state.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an SED provided with a spacer to be inspected.
FIG. 2 is a perspective view of the SED taken along a line AA in FIG. 1;
FIG. 3 is an enlarged sectional view showing the SED.
FIG. 4 is a perspective view showing a spacer structure of the SED.
FIG. 5 is a side view showing a spacer inspection apparatus according to the embodiment of the present invention.
FIG. 6 is a perspective view showing the inspection device.
FIG. 7 is a plan view schematically showing a method of inspecting the installation surface of the spacer by dividing the installation surface into a plurality of sections.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... front board | substrate, 12 ... rear board | substrate 14 ... side wall, 15 ... vacuum envelope 16 ... phosphor screen, 18 ... electron emission element 22 ... spacer structure, 24 ... grid 30a ... 1st spacer, 30b ... 2nd spacer
52: lighting device, 54: imaging device,
56 ... Image processing device

Claims (6)

In a spacer inspection method for inspecting an arrangement state of a plurality of spacers provided on an installation surface,
Irradiating the spacer with inspection light from a direction inclined from 0 to 20 degrees with respect to the installation surface,
Detecting the scattered light scattered by the spacer,
A method of inspecting a spacer, comprising inspecting an arrangement state of the spacer based on the detected scattered light. The installation surface and the spacer are imaged under the irradiation of the inspection light, and the obtained image data is compared with reference data indicating a correct arrangement state of the prepared spacer to determine the arrangement state of the spacer. The method for inspecting a spacer according to claim 1, wherein: The method for inspecting a spacer according to claim 2, wherein an image of the spacer is taken by an image pickup device provided to face the installation surface. The installation surface is divided into a plurality of regions, an image is taken for each of the regions, image data for each of the obtained regions is combined, and the combined image data thus combined is compared with the reference data to determine the arrangement state of the spacer. The method for inspecting a spacer according to claim 3, wherein the determination is performed. In a spacer inspection device that inspects the arrangement state of a plurality of spacers provided on an installation surface,
A light source for irradiating the spacer with inspection light from a direction inclined from 0 to 20 degrees with respect to the installation surface;
An imaging device that is provided to face the installation surface and captures scattered light scattered by the spacer,
An inspection device for a spacer, comprising: An image processing device that processes an image of the spacer captured by the imaging device; the image processing device includes a data storage unit storing reference data indicating a correct arrangement state of the spacer; and an image captured by the imaging device. A data comparing unit for comparing the image data of the spacer with the reference data, and a determining unit for determining an arrangement state of the spacer according to a comparison result by the data comparing unit. Item 5. An inspection device for a spacer according to Item 4.

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