JP3367474B2 - Plasma display panel inspection apparatus, plasma display panel back plate manufacturing method, and plasma display panel - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma display panel inspection apparatus and manufacturing method, and more particularly,
RGB formed on the back plate of the plasma display panel
The present invention relates to an apparatus for inspecting unevenness of coating of a phosphor and a method for manufacturing a desired plasma display panel back plate using the inspecting apparatus.

[0002]

2. Description of the Related Art Usually, R (red), G (green), and B (blue) phosphors are repeatedly applied in stripes on the back plate of a plasma display panel. If the body is not applied uniformly, color unevenness may occur with uneven brightness and color tone of the display, or a color mixture in which a phosphor of a certain color mixes with the color of the adjacent phosphor layer, or Due to the omission, problems such as the presence of dark spots that cannot be placed in a light emitting state occur.

In order to prevent the back plate having such a defect in the phosphor coating state from being stuck to the front plate,
In addition, if a problem occurs in the coated state, it is necessary to perform a reliable inspection with the back plate alone in order to immediately correct the defective part in the manufacturing process and prevent the production of defective products. .

In this inspection, normally, ultraviolet rays are applied to the back plate of the plasma display panel coated with each phosphor,
This is performed by receiving the light that the phosphor layer is excited and emitted. For example, Japanese Patent Laid-Open No. 11-16498 discloses a method of irradiating ultraviolet rays from above the back plate to inspect and inspect the light emitted from the phosphor layer and emitted from above.

However, the method disclosed in Japanese Patent Application Laid-Open No. 11-16498 has a problem that color unevenness cannot be detected accurately. That is, the color unevenness is caused by the nonuniform shape of the phosphor layer, but the above method cannot detect the shape change of the phosphor layer with high sensitivity. Because,
When the shape of the phosphor layer is changed, the light emission amount is likely to change on the thin side surface portion of the phosphor layer, but the light emission amount is hardly changed on the thick bottom surface portion of the phosphor layer. This is because the bottom surface of the phosphor, which has a small change in the amount of emitted light, is mainly imaged.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above problems of the prior art and to inspect the phosphor formed on the back plate of the plasma display panel, which can detect color unevenness with high accuracy. And a method of manufacturing a back plate of a plasma display panel using the inspection apparatus.

[0007]

In order to solve the above problems, a plasma display panel inspection apparatus according to the present invention is provided with an R formed on a back plate of a plasma display panel.
An apparatus for inspecting a coated state of a GB phosphor, which is RGB
An ultraviolet ray irradiating means for irradiating the phosphor layer with ultraviolet rays is disposed, and an angle between the image pickup direction and the back plate is 5 to 45 degrees, and the light emission from the side surface of the RGB phosphor layer is detected to generate a video signal. It is characterized in that it has an image pickup means for outputting and a processing means for comparing the video signal with a predetermined reference value and judging whether the coating state of the RGB phosphor is good or not based on the difference with the reference value.

Further, in the inspection device according to the present invention,
RGB formed on the back plate of the plasma display panel
A plurality of phosphor layers are arranged in parallel lines, the ultraviolet irradiation means is composed of a means for emitting light in a rod shape, the longitudinal direction is arranged along the phosphor layer, and the image pickup means is a one-dimensional light receiving element. It is also possible to adopt a configuration in which the means is arranged so that the image can be output one-dimensionally along the phosphor layer.

Further, in order to detect not only the color unevenness but also the color mixture and the dark spot, the image pickup means is required to pick up the light emitted from the side portions on both sides of the RGB phosphor layer.
Both are arranged two, it is preferable that at least one positioned to image the light emission of the bottom portion of the RGB phosphor layers.

Further, in the inspection device according to the present invention,
The angle between the ultraviolet irradiation direction and the back plate is 5 to 45 degrees, 7
The ultraviolet irradiation means for irradiating the RGB phosphor layer with ultraviolet rays are respectively arranged at positions of 0 to 110 degrees and 135 to 175 degrees, and the angle between the imaging direction and the back plate is 70 to 11.
An image pickup unit which is arranged so as to be 0 degree and which detects a light emission from the RGB phosphor layer and outputs a video signal, and compares the video signal with a predetermined reference value.
It is also possible to adopt a configuration having a processing means for judging whether or not the coating state of the phosphor is good. When the ultraviolet light emitted by the ultraviolet irradiation device has no directivity, the ultraviolet irradiation direction is the direction from the ultraviolet irradiation position to the imaging position.

Further, in the inspection device according to the present invention,
It has a means for transmitting and irradiating ultraviolet rays through an optical fiber,
Ultraviolet irradiation means for irradiating the RGB phosphor layer with ultraviolet rays;
Outputs video signal by detecting light emission from RGB phosphor layer
Image pickup means, and compare the video signal with a predetermined reference value.
Based on the difference with the value, it is possible to judge the quality of the coated state of the RGB phosphor.
It is also possible to adopt a configuration having a processing means for disconnecting. Further, in the inspection apparatus according to the present invention, the RGB phosphor layers formed on the plasma display panel back plate are arranged in a plurality of parallel lines, and the image pickup means is a means in which the light receiving elements are one-dimensionally arranged. The ultraviolet irradiating means has means for transmitting and irradiating the ultraviolet light through an optical fiber, the angle between the ultraviolet irradiating direction and the back plate is 5 to 45 degrees, and the back irradiating direction is imaged by the imaging means. It is also possible to adopt a configuration in which the angle with the upper line segment is 40 to 50 degrees. In order to detect the shape change of the phosphor layer with high sensitivity, the image pickup means takes an image by using a focus position where the signal amplitude width of the output video signal is 30 to 70% of the focused point on the upper surface of the back plate. Is preferred.

In order to detect the shape change of the phosphor layer with high sensitivity, the image pickup means uses the focus position where the signal amplitude width of the output video signal is 30 to 70% of the focus at the upper surface of the back plate. It is preferable to take an image.

Further, a shape measuring means is further provided, and the R
It is preferable to measure at least one surface shape of each color of the GB phosphor layer.

In the method of manufacturing a plasma display panel according to the present invention, the coating state of the RGB phosphors formed on the back plate of the plasma display panel is inspected by using the above-described inspection device, and the obtained defect information is obtained. The method is characterized by discriminating between a non-defective product and a defective product based on.

Further, in the method for manufacturing a plasma display panel according to the present invention, the coating state of the RGB phosphors formed on the back plate of the plasma display panel is in-line inspected by using the above-mentioned inspection device to obtain the result. Based on the defect information thus obtained, the RGB phosphor paste is printed on the back plate, then dried and fired while the phosphor physical property adjustment conditions, printing conditions, drying conditions, or firing conditions are optimally controlled. The method is characterized by that.

The plasma display panel according to the present invention is characterized by using the back plate manufactured by the above manufacturing method.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a plasma display panel inspection apparatus according to an embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a back plate of a plasma display panel (hereinafter, also abbreviated as PDP) to be inspected. The PDP back plate 1 has a back plate 1 as shown in FIG. R (red), G (green), B (blue) phosphor 305, 306,
307 are applied repeatedly in a striped pattern.

As the plasma display panel 300, as shown in FIG. 3, RGB phosphors 305, 306 and 307 are provided on the rear glass substrate 301, on the dielectric layer 303 on which the address electrodes 302 are arranged, and between the partition walls 304. Above the PDP back plate 1 in which stripes are repeatedly coated in sequence, a front plate 308 having a dielectric layer 310 on which the display electrodes 309 are arranged and a protective film 311 are provided. A discharge gas is enclosed in a space with the front plate.

The discharge gas is turned into plasma by the voltage applied between the display electrode 309 and the address electrode 302, and ultraviolet rays are generated, whereby the phosphor layer at the selected position is colored and the color of each phosphor is colored. A desired color is displayed by a combination of the above.

Plasma is generated in the space between the phosphor layer and the front plate, and the amount of ultraviolet rays generated, that is, the amount of display light, changes depending on the shape of this space. That is,
If the shape of the phosphor is not uniform, color unevenness may occur. Therefore, it is necessary to make the shape of the phosphor layer uniform and keep the shape of the space uniform.

RGB phosphor 305 on the PDP back plate 1,
The coating of 306 and 307 is performed by screen printing as shown in FIG. 4, for example. As shown in the side view of FIG. 5, the screen printing is performed by first opening the opening 40 of a predetermined width.
3, the mask screen 402 provided at a pitch three times the pitch p is aligned with the PDP back plate 1, and is arranged so as to face the space 404 between the partition walls.

Next, as shown in FIG. 5a, a phosphor paste 405 in which a phosphor of a predetermined emission color and a binder are mixed is dropped into the space 404 between the partition walls through the opening as shown in FIG. 5a. At this time, as the phosphor paste 405, in order to provide the space where plasma is generated as described above, the solid content concentration is 10 to 50%.
Use the one that The squeegee is moved in the direction of the arrow in order to push this phosphor paste from the opening toward the glass substrate. In addition, here, conditions such as the moving speed, the angle, and the pushing amount of the squeegee are set so that the space between the partition walls is almost completely filled with the phosphor paste as shown in FIG. 5b.

Next, the phosphor paste 405 is dried and baked to remove the binder component and form a phosphor layer having a predetermined shape.

The shape of the phosphor varies depending on the amount of the phosphor paste dropped between the partition walls, the positional relationship between the openings and the partition walls, the drying and firing conditions, and the like. For example, in FIG.
601a shows a cross-sectional view immediately after printing when the paste amount is appropriate. This phosphor paste is dried and fired to form 601 in FIG. Similarly, FIG. 602a shows a cross-sectional view immediately after printing when the paste amount is too large, FIG. 603a shows a small paste amount, and FIG. 604a shows a sectional view immediately after printing when the opening is not located at the center between the partition walls. Further, similarly, FIGS. 603, 603, and 604 show cross-sectional views after drying and firing.

By the way, since only the phosphor from the surface to a certain depth emits light in the phosphor layer irradiated with ultraviolet rays, when ultraviolet rays having a constant intensity are given, the phosphor layer is thick when it is thin. The amount of emitted light also increases in proportion to this, but when the thickness exceeds a certain value, the amount of emitted light does not increase any further. The film thickness at which the amount of emitted light does not increase is about 20 to 30 μm, although it varies depending on the type of phosphor.

On the other hand, the film thickness of each part of the phosphor layer after drying and firing is 30 μm or more at the bottom surface part, and the film thickness becomes thinner toward the upper part of the side surface part, and most part of the film thickness is 30 μm or less. Is. Therefore, when the shape of the phosphor layer changes,
The amount of light emitted from the bottom surface hardly changes, but the amount of light emitted from the side surface changes as the film thickness changes.

Therefore, when the shape of the phosphor layer changes, it is possible to perform a highly accurate inspection by detecting only the light emission from the side surface.

Further, as another defect generated in the phosphor forming step, as shown in FIG.
In the arrangement of Nos. 06 and 307, the portion 7 in which the phosphor of one color partially protrudes into the phosphor portion of the next color to cause color mixture 7
01, or a portion that has become a dark spot 702 due to missing coating may occur. In order to detect these defects, it is necessary to inspect the entire surface of the phosphor layer, so imaging from above is desirable.

The phosphor layer forming step is not limited to the screen printing method, and can be applied to a back plate manufactured by another method such as a nozzle coating method.

RGB phosphor 305 on the PDP back plate 1,
The above defects in the coating of 306 and 307 are inspected by the inspection apparatus shown in FIG. Again with reference to FIG. 1, the PDP back plate 1 is transported by the transport device 3 including the transport rollers 2 and the transport device 3 is controlled by the drive control device 4.

An ultraviolet irradiation device 5 is provided above the transfer device 3.
And imaging devices 6a, 6b, 6c are arranged. The carrying device 3 is for scanning the imaging range of the imaging device 6 over the entire surface of the PDP back plate 1, and carries the PDP back plate 1 at a constant speed. The ultraviolet ray irradiating device 5 is for exciting and emitting the phosphor coated on the PDP rear plate 1, and irradiates the PDP rear plate 1 with ultraviolet rays.

The image pickup devices 6a to 6c divide a certain range on the PDP back plate 1 into pixels, measure the brightness of each pixel, convert the video signals into video signals, and send them to the image processing device 8.
In these image pickup devices, light-receiving elements are arranged in a one-dimensional manner and built-in, and it is possible to output a one-dimensional image along the stripe direction of the RGB phosphors. R
In order to obtain the respective images of the GB phosphor, the image pickup device 6
It is preferable to use color line sensor cameras as a to 6c because the optical system can be simplified. The image pickup devices 6a and 6b are for inspecting color unevenness, and detect light emission from the side surface of the phosphor layer. Therefore, the angle between the imaging direction and the PDP back plate 1 is preferably in the range of 5 to 45 degrees. Further, when the partition wall height is h and the partition wall interval is P, the angle θ obtained by the following formula (1) is more preferable. θ = tan ⁻¹ (p / h) (1) The image pickup device 6c is for detecting a color mixture or a dark spot, and the angle between the image pickup direction and the PDP back plate 1 is 70 to 11.
A range of 0 degrees is preferred.

In this embodiment, the output signals from the image pickup devices 6a to 6c are sent to the image processing device 8 via the RGB signal amplification devices 9a to 9c, respectively. The RGB signal amplifying devices 9a to 9c preliminarily output the image signals of the respective colors in order to make the signal intensities to be transmitted to the image processing device 8 uniform even when the emission intensity ratios of the RGB phosphors obtained by the imaging device 6 are different. It is amplified at the set magnification and transmitted to the image processing device 8. Therefore, the RGB signal amplifiers 9a to 9c can input the RGB signal intensities to the image processing device 8 with the same signal intensity, and the processing accuracy is improved. The adjustment of the signal intensity ratio of each RGB is
You may attach a color correction filter to an imaging device, and it may perform.

The image processing device 8 as the signal processing means is
This is for detecting defects that occur in the phosphor, and the image signals of the RGB phosphors imaged by the imaging device 6 are input, and image analysis is performed by a known image processing technique to detect defects. That is, the video signals from the RGB signal amplifying devices 9a to 9c are compared with a predetermined reference value, and the coating state of the RGB phosphor is determined based on the difference with the reference value.

The control device 10 is connected to the transport device 3, the lighting control device 7, and both image processing devices 8, and the transport operation of the transport device 3 and the lighting control device 7 are performed based on a predetermined procedure.
The operation command is given to the ultraviolet irradiation operation by the ultraviolet irradiation device 5 via the, and the imaging and signal processing operations by the imaging devices 6a to 6c and the image processing device 8. A display device 11 is connected to the image processing device 8, and the display device 11 is for displaying each defect information detected by both image processing devices 8.

In the plasma display panel inspection apparatus having the above-described structure, the PD from the upstream side apparatus is used.
When the P back plate 1 is loaded into the transport device 3, the transport device 3 gives a back plate loading signal to the control port 10 to start transporting the back plate 1. The control device 10 operates the ultraviolet irradiation device 5 when the back plate input signal is input. Transport device 3
When the rear plate 1 is conveyed to the image pickup position, the rear plate detection sensor (not shown) incorporated therein gives a rear plate entry signal to the control device 10. When the back plate approach signal is input, the control device 10 gives an image capturing start signal to the image processing device 8, and the image processing device 8 starts capturing the image signals output from the imaging devices 6a to 6c. The RGB signal amplifying devices 9 a to 9 c amplify the image signals input from the image capturing devices 6 a to 6 c, respectively, by amplifying the RGB signals at a magnification determined for each product type, and output the amplified signals to the image processing device 8. The image processing device 8 stores the image signal and detects a defect occurring in the PDP back plate 1 by a known image processing technique. The image processing device 8 gives an image capture end signal to the control device 10 after the image capture is completed, and the control device 10 causes the lighting control device 7 to operate.
The ultraviolet irradiation device is stopped via.

In particular, in the present invention, in the case of the configuration of imaging from an oblique direction, the influence of the bottom portion where the amount of emitted light hardly changes when the shape of the phosphor layer changes is eliminated, and the change in film thickness is suppressed. Since the side surface portion where the light emission amount changes can be imaged in detail, highly accurate inspection can be performed. Furthermore, arrange the imaging devices so that they face each other diagonally,
The deviation of the phosphor layer can be detected by detecting the light emission on both sides of the phosphor layer. Further, when the processing means integrates the video signals in the substrate scanning direction, the shape change of the phosphor layer can be detected with higher sensitivity, so that a more accurate inspection can be performed. Further, the same effect can be obtained when the image pickup unit uses a focus position where the signal amplitude width of the output video signal is 30 to 70% of the focus at the upper surface of the back plate. Furthermore, using a shape measuring device such as a laser displacement meter,
By measuring the shape of each layer of the GB phosphor at least at one place, it is possible to evaluate in what shape the phosphor layer of each color is uniformly formed.

By using such an inspection device, the coating state of the RGB phosphors formed on the PDP back plate 1 is inspected, and whether the PDP back plate 1 is a good product or not is based on the obtained defect information. It is possible to determine whether the product is defective. In addition, the in-line inspection can be performed, and the manufacturing conditions of the RGB phosphor layer can be immediately corrected based on the obtained defect information.

FIG. 8 shows another embodiment of the present invention, which shows a configuration in which ultraviolet rays are obliquely irradiated and images are obliquely imaged. Here, the back plate and the phosphor layer extend in the direction perpendicular to the paper surface, and as the image pickup device, a one-dimensional array of light receiving elements extends in the direction perpendicular to the paper surface, The ultraviolet irradiation means extends in a rod shape in a direction perpendicular to the paper surface. The angle between the imaging direction and the back plate is 5-4
It is arranged so as to be 5 degrees. Further, the ultraviolet irradiation direction and the back plate are arranged so that the angle between them is 5 to 60 degrees. According to this configuration, even when the transmittance of the partition wall 304 is high, only the side surface portion on the side to be inspected can emit light, so that the inspection can be performed with higher accuracy. Also in the embodiment of FIG. 1, the same effect can be obtained by turning on the two ultraviolet light sources separately and capturing an image with the imaging device on the turned-on side.

FIG. 9 shows another embodiment of the present invention, in which ultraviolet irradiation devices 502a and 502 which can be separately turned on.
b and 502c. The extending direction of the partition walls and the phosphor layer of the back plate, the arrangement direction of the light receiving elements of the image pickup device, and the extending direction of the ultraviolet irradiation means are the same as those in FIG. The ultraviolet irradiation means 502a and 502b are arranged so that the angle between the irradiation direction and the back plate is 5 to 45 degrees, and the irradiation direction of the ultraviolet irradiation means 502c is between 70 and 90 degrees. According to this configuration, the ultraviolet irradiation devices 502a, 502b, and 502c are sequentially turned on each time the substrate is scanned, and if scanning is performed three times, all defects generated in the phosphor can be inspected by one imaging device, which is inexpensive. Can be inspected.

FIG. 10 shows another embodiment of the present invention, which has an ultraviolet irradiation device 12 using an optical fiber. The extending direction of the partition walls and the phosphor layer of the back plate, the arrangement direction of the light receiving elements of the image pickup device, and the extending direction of the ultraviolet irradiation means are the same as those in FIG. FIG. 11 shows a top view of this embodiment. According to this configuration, the ultraviolet irradiation devices 503a, 503b, and 503c are turned on in turn every time the substrate is scanned, and the PDP back plate 1 of FIG. 2 or P of FIG.
It is possible to inspect in any case of the DP back plate 103.

FIG. 12 shows another embodiment of the present invention, in which the PDP back plate 1 is fixed and the image pickup devices 601a, 601a, 6b.
01b, 601c, and the ultraviolet irradiation device 501 are moved by the XY gantry stage 201, and an example of an inspection device for inspecting the entire surface of the PDP back plate 101 is shown.

FIG. 13 shows still another embodiment of the present invention, in which the image pickup device 602 is mounted on the PDP back plate 102.
a, 602b, 602c are arranged in a line, and the imaging device 30
2. For the ultraviolet irradiation device 502, P by the transfer device 202
An example of an inspecting device is shown which inspects the entire surface when the DP rear plate 103 is conveyed.

In the present invention, a grid-shaped partition wall, for example, as shown in FIG. 15, is used, except that the R, G, B phosphors shown in FIGS. 2 and 13 are purely and repeatedly applied in stripes. It is also possible to deal with the inspection of the back plate having the block-shaped phosphor layer formed therebetween.

[0046]

Example (Example 1) A back plate was prepared. PD2
An address electrode was prepared by using a photosensitive silver paste. A line width of 50 μm, a thickness of 3 μm, and a pitch of 250 after applying a photosensitive silver paste, drying, exposing, developing, and baking steps.
A μm address electrode was formed.

Next, a dielectric layer was formed. The dielectric paste was applied by screen printing to a thickness of 20 μm so as to cover the address electrodes in the display area, and then baked at 570 ° C. for 15 minutes to form a back dielectric layer.

Partition walls were formed on the dielectric layer by a photosensitive paste method. After applying the photosensitive paste, it was exposed using a photomask with a line width of 30 μm in the opening, and then developed in an aqueous solution of ethanolamine, and further exposed to 1 ° C at 560 ° C.
By firing for 5 minutes, pitch 250 μm, line width 3
A partition wall having a thickness of 0 μm and a height of 130 μm was formed.

Next, phosphor paste was applied between the partition walls in the order of RGB by screen printing. After drying, baking is performed to form a phosphor layer so that the thickness of the bottom surface portion becomes 40 μm,
A back plate was produced.

Example 2 A test was conducted using the apparatus shown in FIG. The ultraviolet irradiation device 5 uses an excimer lamp having a lighting frequency of 2 MHz, an emission length of 600 mm, and an irradiation ultraviolet central wavelength of 222 nm. Two excimer lamps are arranged in parallel with the phosphor layer at a position 50 mm from the upper surface of the PDP back plate prepared in Example 1. installed. A 2048-pixel color line sensor camera was used for the imaging devices 6a and 6b, and a 5000-pixel color line sensor was used for the imaging device 6c. Imaging device 6a, 6
b is arranged so as to face the position where the angle between the back plate and the imaging direction is 30 degrees, and the lens is selected so that one pixel corresponds to 300 μm on the PDP back plate. The imaging device 6c is arranged at a position where the angle between the back plate and the imaging direction is 90 degrees,
The lens was selected such that one pixel corresponds to 120 μm on the PDP back plate. The PDP back plate 1 has color unevenness, dark spots,
7m / mi by the transfer device 3 using the substrate containing mixed colors
It was conveyed by n and inspected.

As a result, it was possible to accurately detect color unevenness, dark spots, and color mixture of the RGB phosphors.

(Embodiment 3) In mass production of a back plate having the same specifications as in Embodiment 1, an in-line inspection was performed with the apparatus shown in FIG. The same ultraviolet irradiation device and imaging device as those used in Example 1 were used. as a result,
We were able to detect defects that occurred in the phosphor with high accuracy, and even if defects frequently occurred, we could minimize the production of defective products by immediately identifying the cause and correcting it from the defect information. . Therefore, the manufacturing cost could be reduced. Further, as a result of panel-assembling the PDP back plate and front plate judged to be non-defective, a plasma display panel having good display performance was obtained.

Example 4 A test was carried out using the apparatus shown in FIG. Ultraviolet irradiation device 502a, 502b, 503c
Uses a low-pressure mercury lamp with a lighting frequency of 20 kHz, an emission length of 600 mm, and an irradiation ultraviolet center wavelength of 254 nm, and the angle between the PDP back plate and the ultraviolet irradiation direction is 20 degrees, 80 degrees, 1
It was set so that it would be 00 degrees and 160 degrees. As the image pickup device 6, one color line sensor camera of 5000 pixels was used, and it was installed at a position where the angle between the PDP back plate and the image pickup direction was 90 degrees. Moreover, one pixel has 12 pixels on the back plate of the PDP.
The lens was chosen to correspond to 0 μm. As the PDP back plate 1, a substrate including color unevenness, dark spots, and color mixture was used, the substrate was transported by the transport device 3 at 7 m / min, and the entire substrate was scanned three times for inspection.

As a result, it was possible to accurately detect color unevenness, dark spots, and color mixture of the RGB phosphors.

Example 5 A test was conducted using the apparatus shown in FIG. The ultraviolet irradiation device 503a has a lighting frequency of 20.
A mercury lamp having a center wavelength of 254 nm for irradiation ultraviolet light of kHz was used as an ultraviolet light source, and the quartz optical fiber was used to transmit and irradiate the ultraviolet light. The angle between the UV irradiation direction and the PDP back plate is 25.
Degree, UV irradiation direction and PDP imaged by the imaging means
The angle with the line segment on the back plate was 45 degrees.
The ultraviolet irradiation device 503b used the same ultraviolet light source as 503a, used the same quartz optical fiber as 503a, and was installed so as to face 503a, as shown in FIGS. 10 and 11. The ultraviolet ray irradiating device 503c shares the ultraviolet ray source with 503a, the quartz optical fiber forms an angle of 80 degrees between the ultraviolet ray irradiating direction and the PDP rear plate, and the ultraviolet ray irradiating direction and the line segment on the PDP rear plate imaged by the imaging means. The angle was set to 90 degrees. The imaging device 6 includes
One 5000-pixel color line sensor camera was used and installed at a position where the angle between the PDP back plate and the imaging direction was 90 degrees. Also, one pixel is 120 on the back plate of the PDP.
The lens was chosen to correspond to μm. As the PDP back plate, two types of PDP back plate 103 and PDP back plate 104 shown in FIG.
7m / mi by the transfer device 6 using the substrate containing mixed colors
The inspection was carried out by transporting with n and scanning the entire substrate three times.

As a result, it was possible to accurately detect the color unevenness, the dark spots, and the color mixture of the R, G, and B phosphors even on the substrates having different phosphor layer stripe directions.

[0057]

The present invention is arranged so that the angle between the direction of UV irradiation and the back plate is 5 to 110 degrees, and the RGB
Since the phosphor layer is arranged such that the ultraviolet ray irradiating unit irradiates the ultraviolet ray and the angle between the image pickup direction and the back plate is 5 to 45 degrees, it is possible to accurately inspect the color unevenness.

Further, the ultraviolet irradiating means is a means for emitting light in a rod shape, the longitudinal direction is arranged in the direction along the phosphor layer, and the imaging means is a means for arranging the light receiving elements one-dimensionally. Since it is arranged so that an image can be output one-dimensionally along the phosphor layer, even if a plurality of RGB phosphor layers formed on the back panel of the plasma display panel are arranged in parallel lines, color unevenness will occur. Can be inspected accurately.

[0059] Further, the imaging means is arranged both two least <br/> rather to image light emission from the respective opposite sides side portion of the RGB phosphor layers, imaging the light emission of the bottom portion of the RGB phosphor layers If at least one of them is arranged as described above, color unevenness, color mixture, and dark spots can be inspected.

Further, the ultraviolet ray irradiating means is arranged such that the angle between the ultraviolet ray irradiating direction and the back plate is 5 to 45 degrees, 70 to 110 degrees,
When the image pickup means are arranged at positions of 135 to 175 degrees such that the angle between the image pickup direction and the back plate is 70 to 110 degrees, the color unevenness of one image pickup means, Color mixing and dark spots can be detected, and inspection can be performed at low cost. In addition, the UV irradiation means
If you have a means to transmit and irradiate ultraviolet rays
The substrate with different stripe direction of the phosphor layer,
However, the color unevenness, dark spots, and color mixture of each of the RGB phosphors
Can be detected accurately.

Further, the image pickup means is composed of one-dimensionally arranged light receiving elements, and the ultraviolet ray irradiation means has a means for transmitting and irradiating the ultraviolet rays through an optical fiber, and the angle between the ultraviolet ray irradiation direction and the back plate. Is 5 to 45 degrees, and the angle between the ultraviolet irradiation direction and the line segment on the back plate imaged by the imaging means is 40 to 50 degrees, so that the RGB phosphor layers are parallel lines. It is possible to inspect a plurality of plasma display panel rear plates arranged in a line, regardless of the orientation of the phosphor layer stripes.

Further, when the image pickup means picks up an image by using the focus position where the signal amplitude width of the output video signal is 30 to 70% of the focused point on the upper surface of the rear plate, the shape change of the phosphor layer is changed. Can be detected with high sensitivity, and color unevenness can be accurately inspected.

Further, a shape measuring means is further provided, and the R
When measuring at least one surface shape of each layer of the GB phosphor, it is possible to evaluate in which shape the phosphor layers of each color are uniformly formed. The shape of can be guaranteed to the user.

Further, when the inspection apparatus of the present invention is applied to the manufacturing process of the plasma display panel back plate, it is possible to surely judge whether the product is a good product or a defective product and prevent the defective product from flowing out to the customer. Further, since the defective portion can be immediately corrected, the production of defective products can be minimized and the production cost can be reduced.

Furthermore, when a plasma display panel is manufactured by using the PDP back plate judged to be non-defective by the inspection device of the present invention, a plasma display panel having good display performance can be obtained.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a plasma display panel inspection apparatus according to an embodiment of the present invention.

FIG. 2 is a schematic plan view of a back plate of a plasma display panel.

FIG. 3 is a partial vertical sectional view of a plasma display panel.

FIG. 4 is a perspective view showing an example of phosphor printing on a plasma display panel rear plate.

FIG. 5 (a) is a vertical cross-sectional view showing an example of phosphor printing on the back plate of the plasma display panel. FIG. 3B is a partial vertical cross-sectional view immediately after the printing process of the back panel of the plasma display panel. (C) A partial vertical cross-sectional view of the plasma display panel rear plate after drying and firing.

FIG. 6A is a partial vertical cross-sectional view immediately after the printing process of the back plate of the plasma display panel. (B) It is a partial longitudinal cross-sectional view after drying and baking of a plasma display panel back plate.

FIG. 7 is a partial plan view of a plasma display panel rear plate showing another example of a defective coating state of RGB phosphors.

FIG. 8 is a configuration diagram of a plasma display panel inspection apparatus according to another embodiment of the present invention.

FIG. 9 is a configuration diagram of a plasma display panel inspection apparatus according to still another embodiment of the present invention.

FIG. 10 is a configuration diagram of a plasma display panel inspection apparatus according to still another embodiment of the present invention.

11 is a partial plan view of the embodiment shown in FIG.

FIG. 12 is a schematic perspective view of a plasma display panel inspection apparatus according to still another embodiment of the present invention.

FIG. 13 is a schematic perspective view of a plasma dispanel inspection apparatus according to yet another embodiment of the present invention.

FIG. 14 is a schematic plan view showing another example of the back plate of the plasma display panel.

FIG. 15 is a schematic plan view showing another example of the back plate of the plasma display panel.

[Explanation of symbols]

1, 101, 102, 103, 104 Plasma display panel 2 Conveying device 4 Drive control device 5, 501, 502, 503, 504, 505 Ultraviolet irradiation device 6, 601 Imaging device 7 Lighting device 8 Image processing device 9 RGB signal amplification device 10 control device 11 display device 301 back glass substrate 302 address electrode 303 dielectric layer 304 partition wall 305 phosphor (R color) 306 phosphor (G color) 307 phosphor (B color) 308 front glass substrate 309 display electrode 310 dielectric Layer 311 Protective film 312 Plasma 401 Squeegee 402 Printing screen 403 Opening 404 of printing screen 405 Partition walls 405 Phosphor paste 601 Coating section 602 when the amount of phosphor paste is appropriate A coating when the amount of phosphor paste is too large Landing surface 603 The amount of phosphor paste is too small Kino the coating section 701 mixing portion 702 dark point portion when the opening center of the coating section 604 printing screen is deviated from the center between the barrier ribs

Front page continuation (58) Fields surveyed (Int.Cl. ⁷ , DB name) H01J 9/42 H01J 9/227 H01J 11/02

Claims (9)

(57) [Claims] 1. An apparatus for inspecting a coating state of RGB phosphors formed on a rear plate of a plasma display panel, comprising: ultraviolet irradiating means for irradiating the RGB phosphor layer with ultraviolet rays; an imaging direction; and the rear plate. Is arranged so that the angle is 5 to 45 degrees, and an image pickup unit that detects light emission from the side surface of the RGB phosphor layer and outputs a video signal, compares the video signal with a predetermined reference value, and And a processing unit that determines whether the coating state of the RGB phosphors is good or bad based on the difference between the above. 2. A plurality of RGB phosphor layers formed on a back plate of a plasma display panel are arranged in parallel lines, and an ultraviolet irradiation means is a means for emitting light in a rod shape, and the longitudinal direction is along the phosphor layer. 2. The plasma according to claim 1, wherein the plasma is arranged in a vertical direction, and the image pickup unit is formed by a unit in which light receiving elements are arranged in a one-dimensional manner, and is arranged so as to output a one-dimensional image along the phosphor layer. Display panel inspection device. 3. At least two image pickup means are provided for picking up light emitted from side surfaces on both sides of the RGB phosphor layer.
3. The plasma display panel inspection apparatus according to claim 1, wherein at least one of the RGB phosphor layers is arranged so as to capture an image of light emitted from the bottom surface of the RGB phosphor layer. 4. An apparatus for inspecting a coating state of RGB phosphors formed on a rear plate of a plasma display panel, wherein an angle between an ultraviolet ray irradiation direction and the rear plate is 5 to 45.
, 70 to 110 degrees, and 135 to 175 degrees, respectively, and the angle between the ultraviolet irradiation means for irradiating the RGB phosphor layer with ultraviolet rays and the imaging direction and the back plate is 70 degrees.
An image pickup unit which is arranged so as to have an angle of ~ 110 degrees and which detects a light emission from the RGB phosphor layer and outputs a video signal, compares the video signal with a predetermined reference value, and based on the difference between the reference value and RGB fluorescence, An apparatus for inspecting a plasma display panel, comprising: a processing unit that determines whether or not the body is in a coated state. 5. An apparatus for inspecting the coating state of RGB phosphors formed on a back panel of a plasma display panel, comprising means for transmitting and irradiating ultraviolet rays through an optical fiber, and the ultraviolet rays are applied to the RGB phosphor layer. Ultraviolet irradiation means for irradiating, and an imaging means arranged so that an angle between the imaging direction and the back plate is 5 to 45 degrees, and detecting light emission from the side surface of the RGB phosphor layer to output a video signal. An apparatus for inspecting a plasma display panel, comprising: a processing unit that compares the video signal with a predetermined reference value and determines whether the coating state of the RGB phosphor layer is good or bad based on the difference from the reference value. 6. A plurality of RGB phosphor layers formed on a back plate of a plasma display panel are arranged in parallel lines, and an imaging means is a means in which light receiving elements are arranged in one dimension.
The ultraviolet irradiating means has means for transmitting and irradiating the ultraviolet light through an optical fiber, the angle between the ultraviolet irradiating direction and the back plate is 5 to 45 degrees, and the back irradiating direction is imaged by the imaging means. The angle with the upper line segment is 40-50
The inspection device for a plasma display panel according to claim 4, wherein the inspection device is arranged so as to be arranged at regular intervals. 7. A plurality of RGB phosphor layers formed on a back plate of a plasma display panel are arranged in parallel lines, and an imaging means is a means in which light receiving elements are arranged in one dimension.
The ultraviolet ray irradiating means has a means for transmitting and irradiating the ultraviolet ray through an optical fiber, and is arranged so that the angle between the ultraviolet ray irradiating direction and the line segment on the back plate imaged by the image capturing means is 40 to 50 degrees. The plasma display panel inspection device according to claim 4 or 5. 8. The coating state of the RGB phosphors formed on the back plate of the plasma display panel is inspected by using the inspection device according to claim 1, and based on the obtained defect information. A method for manufacturing a back panel of a plasma display panel, which is characterized by discriminating between a good product and a defective product. 9. An in-line inspection of the coating state of the RGB phosphors formed on the back plate of the plasma display panel using the inspection device according to claim 1, and the defect information obtained is obtained. On the basis of the above, the RGB phosphor paste is printed on the back plate and then dried and fired while optimally controlling the conditions for adjusting the physical properties of the phosphor, the printing conditions, the drying conditions, or the firing conditions. Manufacturing method of back plate of plasma display panel.