JP3749693B2 - Phosphor paste discharge state inspection apparatus and inspection method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an inspection apparatus and an inspection method for inspecting a discharge state of a coating nozzle including discharge ports arranged in a straight line for discharging a phosphor paste.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, there is a display device called a plasma display that displays an image by causing a phosphor to emit light by irradiating ultraviolet rays onto an arbitrary portion of a display plate made of a back plate and a glass panel filled with the phosphor. The back plate is formed with a plurality of grooves at a constant pitch by convex ribs extending in one direction, and each of the grooves is alternately filled with the phosphors corresponding to red, blue and green. ing. As an apparatus for filling the back plate of the plasma display with a phosphor, a coating nozzle having a plurality of ejection holes arranged in a row is used to eject a paste-like phosphor from each ejection hole and to move the nozzle along the groove. There has been known a phosphor layer filling device that moves in a different direction and fills a groove on a back plate with a phosphor paste. As shown in FIG. 13, the coating nozzle used for filling the phosphor paste has a large number of pipe-like discharge ports 2 arranged in the arrangement direction X. The coating liquid made of the phosphor paste is pumped in the direction indicated by the arrow 91 from the inlet of the pipe 90 and discharged from each outlet 2 in the direction indicated by the arrow 92. For the quality of the plasma display, it is necessary that the predetermined amount of phosphor is uniformly and uniformly filled in the phosphor paste filling operation.
[0003]
Conventionally, for the inspection of the filling state of the phosphor layer formed on the back plate of the plasma display panel, after forming the phosphor layer on the back plate, the phosphor is emitted by irradiating ultraviolet rays, and a spectrophotometer, etc. A method of detecting defects such as unevenness of the phosphor layer and color mixing by analyzing the emission spectrum using the above is generally known.
[0004]
[Problems to be solved by the invention]
However, in the method as described above, since defects are detected after the phosphor layer is actually formed on the back plate, there is a problem in that the defective back plate must be repaired or discarded and the production efficiency is lowered. is there.
[0005]
The present invention solves the above-described problem, and a phosphor paste discharge state inspection apparatus and inspection method for inspecting a discharge state from a coating nozzle before performing a phosphor layer forming process on a back plate The purpose is to provide.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the invention of claim 1 is directed to an inspection apparatus for inspecting a discharge state of a phosphor paste discharged from an application nozzle constituted by a plurality of discharge ports arranged in a straight line. A rotatable roller for receiving the phosphor paste discharged from the surface, an ultraviolet irradiation means for irradiating the phosphor paste discharged on the roller with ultraviolet rays, and a phosphor paste discharged on the roller and irradiated with ultraviolet rays. And a camera for measuring the amount of light emission.
[0007]
In the discharge state inspection apparatus having the above-described configuration, the discharge state of the phosphor paste from the application nozzle can be reproduced by rotating the roller, and the phosphor paste that is continuously discharged and applied is irradiated with ultraviolet rays. By measuring the amount of light emitted by using a camera, it is possible to inspect the discharge state from the application nozzle in advance and adjust the application nozzle and the phosphor paste without using an actual back plate. A line sensor camera is suitable as the camera.
[0008]
According to a second aspect of the present invention, there is provided an inspection apparatus for inspecting a discharge state of a paste discharged from an application nozzle constituted by a plurality of discharge ports arranged in a straight line, and a rotatable roller for receiving the paste discharged from the application nozzle And a displacement sensor for measuring the surface state of the paste discharged on the roller, and a moving means for moving the displacement sensor in the direction of arrangement of the discharge ports.
[0009]
In the discharge state inspection apparatus having the above-described configuration, the discharge state of the phosphor paste from the coating nozzle can be reproduced by rotating the roller, and the phosphor paste that is continuously discharged and applied is arranged in the arrangement direction of the discharge ports. By using a displacement sensor having a moving means that can move and measuring the cross-sectional shape of the swelled portion of the phosphor paste while scanning, it is possible to obtain the same operation as that of the above-described inspection apparatus. As the displacement sensor, a laser displacement sensor is suitable.
[0010]
The invention of claim 3 comprises a plurality of discharge ports arranged in a straight line by using a rotatable roller, ultraviolet irradiation means for irradiating ultraviolet light, and a camera for measuring the amount of light emitted from the phosphor. In the inspection method for inspecting the discharge state of the phosphor paste discharged from the coating nozzle, the phosphor paste discharged from the coating nozzle is received by the roller while rotating the roller, and ultraviolet light is applied to the phosphor paste discharged on the roller. Ultraviolet light is irradiated from the irradiation means, the amount of light emitted from the phosphor paste discharged onto the roller and irradiated with the ultraviolet light is measured by the camera, and the discharge state of the paste is inspected based on the measured value. In this configuration, the same operation as that of the inspection apparatus of claim 1 can be obtained.
[0011]
According to a fourth aspect of the present invention, there is provided a paste discharged from an application nozzle constituted by a plurality of discharge ports arranged in a straight line by using a rotatable roller, a displacement sensor, and a moving means for moving the displacement sensor. In the inspection method for inspecting the discharge state, the paste discharged from the coating nozzle is received by the roller while rotating the roller, and the displacement sensor is discharged onto the roller by moving the displacement sensor in the array direction of the discharge ports. The height and width of the swelled paste are measured, and the paste discharge state is inspected by obtaining the cross-sectional area of the paste based on the measured values. In this configuration, the same operation as that of the inspection apparatus according to the second aspect can be obtained.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a discharge state inspection apparatus for a phosphor paste application nozzle according to an embodiment of the present invention will be described with reference to FIGS. 1 to 7. Common members in the drawings are denoted by the same reference numerals, and redundant description is omitted. As shown in FIG. 1, the discharge state inspection apparatus 100 includes a roller 3 at the center, an ultraviolet lamp (ultraviolet irradiation means) 4 that illuminates the roller 3 from above, a line sensor camera 5 that desires the surface of the roller 3 irradiated with ultraviolet rays, A squeegee 7 whose tip is in contact with the roller surface below the roller 3 and a liquid barrier 71 containing the roller 3 and the squeegee 7 are provided. Further, as shown in FIG. 2, a roller motor 8 is connected to the roller 3, whereby the roller 3 is rotated at a predetermined rotational speed in the direction of the arrow in FIG. Although omitted in FIG. 2, the ultraviolet lamp 4 and the line sensor camera 5 are installed in parallel with the longitudinal direction of the roller. Above the roller 3, a coating nozzle 1 used for inspection is installed in parallel to the roller 3 with the distance between the discharge port 2 and the roller 3 being a predetermined distance.
[0013]
With the above configuration, the phosphor paste 6 is continuously ejected from the plurality of ejection openings 2 arranged in a straight line onto the rotating roller 3 to reproduce the actual phosphor filling operation. Then, the fluorescent paste is emitted from the fluorescent paste 6 by irradiating the fluorescent paste 6 discharged onto the roller 3 with ultraviolet rays from the ultraviolet lamp 4. At this time, the length of the ultraviolet lamp 4 is longer than the length of the roller 3 so that uniform ultraviolet rays are irradiated in the longitudinal direction of the roller 3 or the entire length of the roller 3 is ejected. An ultraviolet ray having an intensity sufficient for the fluorescence emission of the phosphor paste is irradiated. Next, the amount of fluorescent light is detected by the line sensor camera 5 and recorded or displayed. The phosphor paste 6 for which the light amount measurement by the line sensor camera 5 is completed in the rotation direction of the rotating roller is scraped off by the squeegee 7. When the surface of the roller 3 is located immediately below the discharge port 2, the roller 3 is not affected by the previous phosphor paste 6.
[0014]
FIG. 3 shows changes in the amount of light in the nozzle width direction detected by the line sensor camera 5. Since the amount of light is determined by the amount of the phosphor paste 6 discharged from each discharge port 2, if the detected light amount is outside the range determined by the preset upper limit value and lower limit value, the light amount The discharge port 2 corresponding to the measurement portion is determined to be in a defective state. In this example, in the nozzle width direction, it is determined that the discharge amount corresponding to the portion a where the light emission amount is smaller than the lower limit value is small due to clogging or the like. In this way, it is possible to continuously inspect the discharge state of the phosphor paste discharged from the coating nozzle.
[0015]
In the above description, the discharge port 2 is described as a pipe shape. However, the same effect as described above can be obtained as long as the discharged phosphor paste has a streak shape. Further, as shown in FIGS. 4 and 5, the discharge state can be similarly inspected in the slit-like discharge port 21 having a continuous discharge port shape. In this case, the phosphor paste 61 is discharged in the form of a sheet, and when a discharge failure such as clogging occurs in the discharge port 21, a defective portion 22 is generated. In the light amount measurement at that time, as shown in FIG. b appears. Since subtle changes in the discharge state, which cannot be obtained by visual inspection of the discharge state, are measured and displayed as numerical data, the discharge state is effectively inspected.
[0016]
In the above description, the light amount emitted from the phosphor paste 6 is collectively detected using the fixed line sensor camera 5. However, as another method, the light amount detection is performed while moving the line sensor camera 5. FIG. 7 shows a case where the above is performed. This inspection apparatus includes a base 12 parallel to the longitudinal direction of the roller 3 and a rail 11 on the base 12. A slide block 14 is slidably connected to the rail 11. Further, the line sensor camera 5 is attached to the upper end of the column 13 whose lower end is fixed to the slide block 14. Further, the ball screw 10 is connected to the slide block 14, and the slide block 14 moves on the rail 11 by rotating the ball screw 10 by the moving motor 15. In this way, the line sensor camera 5 can detect the amount of light emitted by the phosphor paste 6 on the roller 3 over the entire region in the arrangement direction of the discharge ports 2 while moving in a direction parallel to the roller 3. . According to this apparatus, the visual field width of the line sensor camera 5 can be narrowed to increase the resolution, and the change in the amount of light can be detected with higher accuracy than when the entire area is collectively measured.
[0017]
Next, a discharge state inspection apparatus for a phosphor paste application nozzle according to another embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 8, the discharge state inspection device 100 has a roller 3 at the center, a laser displacement sensor 9 set to measure the surface of the roller 3 on the side of the roller 3, and a tip of the roller 3 below the roller 3. And a squeegee 7 in contact with the roller 3, and a liquid barrier 71 containing the roller 3 and the squeegee 7. Further, as shown in FIG. 9, a roller motor 8 is connected to the roller 3, whereby the roller 3 is rotated in the direction of the arrow in FIG. 8 at a predetermined rotational speed. The laser displacement sensor 9 is used after being scanned by a scanning mechanism described below. That is, the rail 11 is provided on the base 12 provided in parallel with the longitudinal direction of the roller 3. A laser displacement sensor 9 is attached to the upper end of a support column 13 having a lower end fixed to a slide block 14 slidably connected to the rail 11. Further, the ball screw 10 is connected to the slide block 14, and the slide block 14 moves on the rail 11 when the ball screw 10 is rotated by the moving motor 15. In this way, the laser displacement sensor 9 scans the surface of the roller 3 over the entire area in the arrangement direction of the discharge ports 2. In addition, above the roller 3, a coating nozzle 1 used for inspection is installed in parallel to the roller 3 with a distance between the discharge port 2 and the roller 3 being a predetermined distance.
[0018]
With the above configuration, the phosphor paste 6 is continuously ejected from the plurality of ejection ports 2 arranged in a straight line onto the rotating roller 3, and the actual phosphor filling operation is reproduced. Then, using the laser displacement sensor 9, for example, a displacement amount based on the surface of the roller 3, that is, a rising amount of the phosphor paste 6 is detected while being scanned and recorded or displayed. The other operations of the squeegee 7 are the same as those in the above-described embodiment, and the description is omitted. The displacement with respect to the reference value in the nozzle width direction has a continuous peak corresponding to the rising of the discharged phosphor paste, as shown in FIG. In the inspection of the discharge state, a reference value is determined for the detected displacement amount, and an area S surrounded by the reference value and the peak of the displacement amount is obtained to obtain a cross-sectional area of the phosphor paste 6 discharged from each discharge port 2. And By comparing the area S thus obtained with the upper limit value and the lower limit value set in advance, the quality of the discharge state of the corresponding discharge port 2 is determined.
[0019]
In the discharge state inspection apparatus using the laser type displacement sensor 9 described above, since the thickness of the paste applied by displacement or discharge is directly measured, the property of the fluorescent substance that emits fluorescence is not necessary. It can also be applied to other coating solutions. Similarly, when the sheet is continuously discharged in the width direction of the application nozzle, the discharge state can be inspected by measuring the change in the application thickness of the discharge liquid.
[0020]
Next, a method for inspecting the discharge state of the phosphor paste application nozzle according to an embodiment of the present invention will be described with reference to the flowchart of FIG. 11 and FIGS. 1 and 2. First, the roller 3 is rotated, the phosphor paste 6 is ejected onto the roller 3, and the phosphor paste 6 from which ultraviolet rays are ejected by the ultraviolet lamp is irradiated, and this state is filled into the actual panel back plate. A continuous state to be reproduced is maintained (# 1). Next, the distribution of the amount of emitted light from the entire area of the phosphor paste discharged from the discharge ports 2 arranged in a straight line is measured by the line sensor camera 5 (# 2). The light quantity measurement result is checked to determine whether the light quantity is within a range determined by a preset upper limit value and lower limit value. If the light quantity is outside, it is determined that the discharge port 2 corresponding to the light quantity measurement portion is in a defective state. Thus, the ejection state is inspected (# 3). If it is determined that the inspection cannot be completed because the quality of the discharge state cannot be determined, the two steps # 2 and # 3 are repeated (NO in # 4). As a result of the inspection, if it is determined that the inspection is finished because there is no problem in the discharge state or there is an obvious problem and the discharge port 2 needs to be checked (YES in # 4), the paste discharge is stopped and the roller is rotated. Stop and stop UV irradiation (# 5), and finish the discharge state inspection.
[0021]
Next, an ejection state inspection method for an application nozzle according to another embodiment of the present invention will be described with reference to the flowchart of FIG. 12 and FIGS. 8 and 9. First, the roller 3 is rotated, and the phosphor paste 6 is discharged onto the roller 3, and this state is maintained as a continuous steady state that reproduces the actual filling operation on the back panel of the panel (# 1). Next, the laser displacement sensor 9 measures the displacement from the surface of the roller 3, that is, the distribution of the amount of swelling of the phosphor paste 6 while scanning the entire area of the phosphor paste discharged from the discharge ports 2 arranged in a straight line. (# 2). The area S surrounded by the predetermined reference value and the peak of the displacement amount is obtained from the measurement result of the displacement amount, and is set as the cross-sectional area of the phosphor paste 6 discharged from each discharge port 2, and the area S thus obtained is obtained. Then, by comparing the upper limit value and the lower limit value set in advance, the discharge state inspection for judging whether the discharge state of the discharge port 2 is good or not is performed (# 3). If it is determined that the inspection cannot be completed because the quality of the discharge state cannot be determined, the two steps # 2 and # 3 are repeated (NO in # 4). As a result of the inspection, if it is determined that the inspection is finished because there is no problem in the discharge state or there is an obvious problem and the discharge port 2 needs to be checked (YES in # 4), the paste discharge is stopped and the roller is rotated. Stop (# 5) and finish the discharge state inspection.
[0022]
The present invention is not limited to the above-described configuration, and various modifications can be made. For example, a more detailed inspection can be performed by using a laser displacement sensor in combination with a combination of an ultraviolet lamp and a line sensor camera and using both data. In addition, the sample collection paper is wrapped around the rotating roller, and after the phosphor paste is applied, the paper is unwound without passing through the squeegee, and this is used as a sample for other inspections or stored. May be. Further, a groove that reproduces the actual configuration of the rear panel of the panel may be provided on the surface of the rotating roller, and the squeegee may have a comb-like structure that removes the phosphor paste in the groove. Further, a roller cleaning device may be provided in order to reliably remove the phosphor paste that has been inspected on the rotation direction of the roller and behind the squeegee.
[0023]
【The invention's effect】
As described above, according to the first aspect of the present invention, by applying the phosphor paste from the discharge port of the application nozzle to the rotating roller, the discharge state can be reproduced without using the back plate as a product. In addition, the amount of light emitted from each discharge port of the application nozzle and application are measured by irradiating the phosphor paste continuously discharged and applied with ultraviolet rays and measuring the amount of light emitted by the phosphor paste using a line sensor camera. It is possible to know the shapes and their distribution, and without using an actual back plate, it is possible to inspect the discharge state in advance and adjust the application nozzle and the phosphor paste.
[0024]
Further, according to the invention of claim 2, the discharge state can be reproduced without using the back plate which is a product, similarly to the inspection apparatus of claim 1 above. In addition, while scanning the cross-sectional shape of the swelled portion of the phosphor paste using a laser-type displacement sensor having moving means for moving the phosphor paste in the array direction of the discharge ports for the phosphor paste that is continuously discharged and applied By measuring, it is possible to know the discharge amount from each discharge port of the application nozzle, the application shape, and their distribution, and without using an actual back plate, the same operation as the inspection apparatus of claim 1 is performed. Obtainable.
[0025]
According to the invention of claim 3, the same action as the inspection apparatus of claim 1 can be obtained, and according to the invention of claim 4, the action similar to that of the inspection apparatus of claim 2 is obtained. be able to.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a discharge state inspection apparatus according to an embodiment of the present invention.
FIG. 2 is a side view of the inspection apparatus.
FIG. 3 is a view showing a received light amount distribution from a phosphor paste measured by the inspection apparatus.
FIG. 4 is a cross-sectional view showing an example in which the inspection apparatus is applied to another application nozzle.
FIG. 5 is a side view of the inspection apparatus.
FIG. 6 is a view showing a received light amount distribution from a phosphor paste measured by the inspection apparatus.
FIG. 7 is a cross-sectional view of an ejection state inspection apparatus according to another embodiment of the present invention.
FIG. 8 is a cross-sectional view of a discharge state inspection apparatus according to still another embodiment of the present invention.
FIG. 9 is a side view of the inspection apparatus.
FIG. 10 is a view showing a displacement amount distribution of a phosphor paste coating thickness measured by the inspection apparatus.
FIG. 11 is a flowchart showing an inspection method according to an embodiment of the present invention.
FIG. 12 is a flowchart showing an inspection method according to another embodiment of the present invention.
FIG. 13 is a perspective view of a coating nozzle that is an application target of the discharge state inspection apparatus of the present invention.
[Explanation of symbols]
1 Coating nozzle 2 Discharge port 3 Roller 4 UV lamp (UV irradiation means)
5 Line sensor camera (camera)
6 Phosphor paste 9 Laser displacement sensor (displacement sensor)

Claims (4)

In the inspection apparatus for inspecting the discharge state of the phosphor paste discharged from the application nozzle constituted by a plurality of discharge ports arranged in a straight line,
A rotatable roller for receiving the phosphor paste discharged from the coating nozzle;
Ultraviolet irradiation means for irradiating the phosphor paste discharged on the roller with ultraviolet light;
A discharge state inspection apparatus comprising: a camera that measures the amount of light emitted from the phosphor paste discharged onto the roller and irradiated with the ultraviolet rays. In the inspection apparatus for inspecting the discharge state of the paste discharged from the application nozzle constituted by a plurality of discharge ports arranged in a straight line,
A rotatable roller for receiving a paste discharged from the application nozzle;
A displacement sensor for measuring the state of the paste surface discharged on the roller;
A discharge state inspection apparatus comprising: a moving means for moving the displacement sensor in the direction in which the discharge ports are arranged. Fluorescence discharged from an application nozzle composed of a plurality of linearly arranged discharge ports using a rotatable roller, ultraviolet irradiation means for irradiating ultraviolet rays, and a camera for measuring the amount of light emitted from the phosphor. In the inspection method for inspecting the discharge state of body paste,
The phosphor paste discharged from the application nozzle is received by the roller while rotating the roller,
Irradiating ultraviolet rays from the ultraviolet irradiation means to the phosphor paste discharged on the roller,
A discharge state inspection method comprising: measuring a light emission amount from a phosphor paste discharged onto the roller and irradiated with ultraviolet rays by the camera, and inspecting a discharge state of the paste based on the measured value. Inspection for inspecting the discharge state of the paste discharged from the application nozzle composed of a plurality of discharge ports arranged in a straight line by using a rotatable roller, a displacement sensor, and a moving means for moving the displacement sensor In the method
Receiving the paste discharged from the application nozzle on the roller while rotating the roller;
While the displacement sensor is moved in the direction of arrangement of the discharge ports, the height and width of the paste discharged onto the roller by the sensor are measured, and the cross-sectional area of the paste is obtained based on the measured value. A discharge state inspection method characterized by inspecting a discharge state.

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