JPH0735645A - Apparatus for inspecting liquid crystal panel - Google Patents

Abstract

PURPOSE:To inspect a liquid crystal panel under the same condition as in the actual use. CONSTITUTION:A liquid crystal panel 2 is placed on a rotatable measuring stage 11. A CCD camera 12 is set over the stage 11. The CCD camera 12 is mounted at a moving/rotating part 13. The moving/rotating part 13 is able to move the camera 12 in three dimensional directions, i.e., X, Y and Z directions. Moreover, the part 13 is able to rotate the camera 12 in a rotational direction theta within the mounting plane. The CCD camera 12 is not only moved, but rotated in an inspecting apparatus 11, so that the liquid crystal panel 2 is photographed in the same state as when the panel is actually used. It becomes accordingly possible to detect angles characteristic of the visual angle, the maximum luminance of the whole photographing screen and each pixel, etc. The measuring stage 11 may be adapted to be movable and rotatable.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inspection device capable of inspecting the performance of a liquid crystal panel in a state similar to that during use.

[0002]

2. Description of the Related Art A liquid crystal panel has a viewing angle characteristic, that is, a characteristic that an image looks different depending on a viewing angle of a display surface. That is, there is a characteristic that the image becomes clearest when viewed from a specific direction, and becomes hard to see when viewed from other directions. Therefore, the performance inspection of the liquid crystal panel needs to be performed in consideration of the actual usage state.

[0003]

By the way, a conventional liquid crystal panel inspecting apparatus includes a measuring table on which the liquid crystal panel is mounted,
Imaging means for imaging the display surface of the liquid crystal panel, for example a CCD
A camera or microscope is fixed, and the pass / fail judgment is made by taking an image of the display surface of the liquid crystal panel with an image pickup device to detect the presence or absence of pixel defects such as unevenness, stains, and lines, and by measuring the brightness. Was.

However, when a liquid crystal panel that has passed the inspection device is incorporated into an electronic device such as a personal computer or a word processor, it is not always viewed from the direction in which the image was taken during the inspection, and it can be viewed from all directions. In many cases, a pixel defect that was not detected during inspection was found.

When a CCD camera is used, the focus points of the three primary colors R, G, and B deviate due to the chromatic aberration of the lens, making it difficult to detect the maximum luminance for all colors. In addition, there is a problem that it is difficult to capture an image at the maximum brightness of each pixel over the entire screen because the focus is deviated between the central portion and the peripheral portion of the captured image.

Therefore, the present invention solves the above-mentioned problems, and proposes a liquid crystal panel inspection apparatus capable of performing a performance inspection in the same state as in use.

[0007]

In order to solve the above problems, in the present invention, a measuring table on which a liquid crystal panel is placed, an image pickup means for picking up an image of the display surface of the liquid crystal panel, and a measuring stand and an image pickup means. A movement and a rotation in which both or one of them is moved in a three-dimensional direction, and at the same time, both or one of the measuring table and the image pickup means is rotated to change the angle between the optical axis of the image pickup means and the display surface of the liquid crystal panel. Means and a display means for displaying the output of the imaging means.

[0008]

As shown in FIG. 1, in this liquid crystal panel inspection apparatus 1, a liquid crystal panel 2 is placed on a rotatable measuring table 11, and a CCD camera 12 is arranged above it. The CCD camera 12 is attached to the camera moving and rotating unit 13. The camera moving and rotating unit 13 is shown in FIG.
As shown in FIG.
It is possible to move in the X, Y, and Z directions, and it is possible to rotate the camera 12 in the rotation direction θ within the mounting surface.

In this inspection apparatus 1, as shown in FIG.
By moving and rotating the CD camera 12 in three dimensions, the distance between the CCD camera 12 and the display surface 21 of the liquid crystal panel 2 and the angle β formed by the optical axis 51 of the CCD camera 12 and the display surface 21 are changed. Therefore, it is possible to inspect the performance of the liquid crystal panel 2 in the same state as in actual use. Therefore, it becomes possible to detect the angle of the viewing angle characteristic, the maximum brightness of each pixel, and the like.

As shown in FIG. 4, both the CCD camera 12 and the measuring table 11A can be moved three-dimensionally and can be rotated in the same state as when the liquid crystal panel 2 is used as described above. It becomes possible to inspect. The CCD camera 12 may be fixed, and only the measuring table 11A may be movable and rotatable.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of a liquid crystal panel inspection apparatus according to the present invention will be described in detail with reference to the drawings.

FIG. 1 shows the structure of a liquid crystal panel inspection apparatus 1 according to the present invention. The inspection apparatus 1 includes a measurement table 11 on which a liquid crystal panel 2 is mounted, a CCD camera 12 for capturing an image of a display surface 21 of the liquid crystal panel 2, and an X direction, a Y direction, and a Z direction indicated by arrows in the CCD camera 12. It has a camera moving and rotating unit 13 capable of moving in a three-dimensional direction, and rotating in a plane orthogonal to the θ direction, that is, the X direction. As the CCD camera 12, it is possible to use one having various functions such as a zoom function, and the output thereof is supplied to the monitor 14 and displayed on the screen.

The output of the CCD camera 12 is also supplied to the control and analysis section 15, where the data is analyzed to detect the brightness of the entire screen or each pixel, for example, or a predetermined pattern is compared with a measurement image. The pass / fail judgment is made. The analysis result is displayed on the analysis monitor 16. The control / analysis unit 15 includes a measurement table 11 and a camera moving / rotating unit 1.
3 is also controlled, and a program and various data required for control are input from the keyboard 17. Each of these parts 11 to 17 is stably mounted on the base 18.

FIG. 2 shows the construction of the measuring table 11 and the camera moving and rotating section 13. A disc-shaped fixing portion 31 is provided below the measuring table 11 and is fixed to the base 18.
On the upper side of the fixed portion 31, a rotating portion 32 having the same size as the fixed portion 31 is attached rotatably in the α direction in the figure. The rotating portion 32 is rotationally driven by a stepping motor 33 attached to the side surface of the fixed portion 31.
The rotating portion 32 is provided with clamp portions 34 for fixing the liquid crystal panel 2 at four positions. The clamp part 34 is movable in the radial direction of the rotating part 32 and can fix the liquid crystal panels 2 having different sizes. Further, a backlight 35 (FIG. 3) for illuminating the liquid crystal panel 2 is attached inside the fixed portion 31, and an opening 36 for passing illumination light is provided in the rotating portion 32.

The camera moving and rotating unit 13 includes a base 18
It is fixed to a plate-shaped mounting portion 19 which is provided upright.
The camera moving / rotating unit 13 may be one commonly used for moving a measuring jig or the like in a three-dimensional direction and rotating it in the mounting surface. Then, as described above, the CCD camera 12
Is used to move in the X, Y, and Z directions and rotate in the θ direction. The camera moving and rotating unit 1
In a general device that can be used as 3, the loading direction of each moving unit is usually called the Z direction, and the two directions orthogonal to this are usually called the X direction and the Y direction, but in this example,
The name of the moving direction is set based on the CCD camera 12.

In the camera moving / rotating unit 13, a Z moving base 41, a Y moving base 42, an X moving base 43, and a rotary base 44 are sequentially stacked. Z moving base 41 and Y
The moving table 42 includes the fixed portions 41A and 42A and the fixed portion 41.
In the recesses 41B and 42B of A and 42A in the Z direction,
Moving units 41C and 42 slidably arranged in the Y direction
C and stepping motors 41D and 42D that slide-drive the moving portions 41C and 42C. The fixed portion 41A of the Z moving base 41 is fixed to the mounting portion 19, and
The fixed portion 42A of the moving base 42 is the moving portion 41 of the Z moving base 41.
It is fixed to C.

The X moving table 43 is a moving part 4 of the Y moving table 42.
The fixed portion 43A fixed to 2C, the moving portion (not shown) movable in the direction orthogonal to the mounting surface of the fixed portion 43A, that is, the X direction, and the stepping motor 43D that slides and drives the moving portion. It is configured. A rotating table 44 is attached to the moving part of the X moving table 43. Figure 2
Moves the rotary base 44 from the fixed portion 43A of the X moving base 43 to X1.
It shows the state where it is moved.

The rotary table 44 has a fixed portion 44A fixed to the moving portion of the X moving table 43 and a mounting surface of the fixed portion 44A.
That is, the rotary unit 44C is rotatable in the θ direction and the stepping motor 44D that rotationally drives the rotary unit 44C. A mounting shaft 44E is provided upright on the rotating portion 44C, and the CCD camera 12 is fixed to the tip thereof.

In this inspection apparatus 1, since the camera moving and rotating unit 13 can move the CCD camera 12 in the X direction, Y direction and Z direction which are orthogonal to each other as described above, the CCD camera 12 is underneath. It is possible to capture an image of the entire display surface 21 of the liquid crystal panel 2 on the side. Further, the distance between the display surface 21 and the CCD camera 12 can be changed appropriately.

Further, in this inspection apparatus 1, the CCD camera 1
2 can be rotated in the θ direction, the optical axis 51 of the CCD camera 12 and the liquid crystal panel 2 can be rotated as shown in FIG.
It is possible to change the angle β formed by the display surface 21 of. At this time, it is possible to image the same inspection portion 22 of the display surface 21 while changing the angle β, for example, from the direction on the right side of the inspection portion 22 at the angle β1, and then from directly above the inspection portion 22. It is possible to take an image, and then from the left side of the inspection portion 22 at an angle β3.

As described above, when the same inspection portion 22 is imaged at different angles, the CCD camera 12 may be moved in the Y direction and then the CCD camera 12 may be rotated. If the CCD camera 12 is moved in the Z direction, the inspection part 2
It is possible to appropriately adjust the distance from 2. Further, by rotating the measuring table 11, the liquid crystal panel 2 can be imaged from any angle and the same inspection as described above can be performed.

In this inspection apparatus 1, as described above, it is possible to change the angle β formed between the display surface 21 of the liquid crystal panel 2 and the optical axis 51 of the CCD camera 12 and take an image. When it is installed in an electronic device such as a word processor or a word processor, the display surface 21 is imaged from the actual viewing direction,
By displaying this on the monitor 14, it becomes possible to detect pixel defects such as unevenness, stains, and streaks, and to analyze other inspection items.

At this time, the display surface 21 and the CCD camera 12
By gradually changing the angle β formed by the optical axis 51 of the liquid crystal panel 1, the brightness of the display surface 21 of the liquid crystal panel 2 is measured, and the data is supplied to the control and analysis unit 15 for analysis.
It is possible to obtain the angle of the viewing angle characteristic. Then, the result can be displayed on the analysis monitor 16.

In the above embodiment, the CCD camera 12
The case where the CCD camera 12 and the measuring table 11A are moved and rotated in the three-dimensional direction has been described. However, as shown in FIG. 4, the CCD camera 12 and the measuring table 11A are attached to the moving and rotating parts 13A and 13B, respectively.
Both of them may be moved and rotated in the three-dimensional direction. Alternatively, the CCD camera 12 may be fixed, and only the measuring table 11A may be moved and rotated in the three-dimensional direction. As a result, it becomes possible to inspect the liquid crystal panel 2 in the same state as in use, as described above.

[0025]

As described above, the present invention makes it possible to move the image pickup means such as a CCD camera and / or the measurement stand in a three-dimensional direction, and display the optical axis of the image pickup means and the liquid crystal panel. The angle formed by the planes is changeable, and the image pickup result by the image pickup means is displayed on the monitor.

Therefore, according to the present invention, the performance of the liquid crystal panel can be inspected under the same conditions as in actual use, and thus the angle of the viewing angle characteristic can be obtained.
It is possible to eliminate the blur of the focus due to the chromatic aberration of the lens, and it is possible to detect the maximum brightness over the entire screen and the maximum brightness of each pixel.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a liquid crystal panel inspection device 1 according to the present invention.

FIG. 2 is a configuration diagram of a measuring table 11 and a camera moving / rotating unit 13.

FIG. 3 is a diagram illustrating a method of adjusting an angle β formed by an optical axis 51 of a camera 12 and a display surface 21 of a liquid crystal panel 2.

FIG. 4 is a diagram illustrating another embodiment.

[Explanation of symbols]

 1 Liquid crystal panel inspection device 2 Liquid crystal panel 11, 11A Measuring stand 12 CCD camera 13 Camera moving / rotating part 13A, 13B Moving / rotating part 14 Camera monitor 15 Control and analysis part 16 Analysis monitor 17 Keyboard 21 Display surface 35 Back Light 41 Z moving table 42 Y moving table 43 X moving table 44 Rotating table 51 Optical axis of CCD camera 12

Claims (1)

[Claims] 1. A measuring table on which a liquid crystal panel is mounted, an image pickup means for picking up an image of the display surface of the liquid crystal panel, and both or one of the measuring stand and the image pickup means
Moving and rotating means for moving in the dimensional direction and changing either or both of the measuring table and the image pickup means to change the angle between the optical axis of the image pickup means and the display surface of the liquid crystal panel, An inspection device for a liquid crystal panel, comprising: a display unit for displaying an output of the image pickup unit.