JP3932115B2 - LCD panel inspection equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a liquid crystal panel inspection apparatus that can perform focusing at high speed.
[0002]
[Prior art]
FIG. 2 is a diagram illustrating a configuration of a conventional example that is generally used, and is disclosed in, for example, Japanese Patent Laid-Open No. 11-174398.
In the figure, reference numeral 2 denotes a lamp for irradiating the liquid crystal panel 1 to be inspected with light.
[0003]
Reference numeral 4 denotes a projection optical unit that projects the light transmitted through the liquid crystal panel 1 onto a screen 3 installed at a predetermined position.
The projection optical unit 4 includes a lens 401 alone or a combination of a plurality of lenses, and is configured to project transmitted light that has been transmitted (modulated) through the liquid crystal panel 1 onto the screen 3.
[0004]
Reference numeral 5 denotes a CCD camera having a viewing angle す る which detects the luminance distribution of the image on the screen 3. An inspection pattern generator 6 drives the liquid crystal panel 1 with a predetermined inspection pattern.
Reference numeral 7 denotes a defect determination unit that determines whether or not there is a point defect in the liquid crystal panel 1 by referring to the inspection pattern and the detection result by the CCD camera 5.
[0005]
In the above configuration, the liquid crystal panel 1 that is the inspection target irradiated with the light from the lamp 2 has a predetermined inspection pattern (on / off pattern for each pixel) based on the control signal from the inspection pattern generator 6. The light from the lamp 2 is modulated so that
[0006]
The on / off pattern formed by the liquid crystal panel 1 driven based on this control signal is projected onto the screen 3 by the lens 401 (projection optical unit 4).
The CCD camera 5 captures the projection image on the screen 3 as luminance information and gives it to the defect determination unit 7.
[0007]
The defect determination unit 7 compares the given luminance information with the inspection pattern, determines whether or not the liquid product panel 1 is configured to form a predetermined pattern, and projects the predetermined pattern onto the screen 7. If it is, it is determined as normal.
[0008]
On the other hand, when the predetermined pattern is not projected on the screen 7, the liquid crystal panel 1 to be inspected is inspected as abnormal, that is, a defective pixel is present.
[0009]
[Problems to be solved by the invention]
However, such an apparatus has the following problems.
(1) It is necessary to accurately form an image of the element to be inspected on the screen surface. For example, the distance between the projection lens and the element to be inspected needs to be adjusted to a reference value of about ± 5 μm.
[0010]
(2) A mechanism for inserting the element to be inspected into the inspection apparatus is necessary, but it is difficult for the insertion mechanism to mechanically maintain the above-described accuracy and reproducibility.
(3) Due to variations in the glass thickness of the liquid crystal panel 1, the position of the liquid crystal panel portion in the optical axis direction is shifted.
[0011]
(4) Therefore, a mechanism for focusing the projection lens is necessary.
(5) On the other hand, in order to detect even a single pixel defect, the resolution of the CCD camera 5 for image quality inspection needs to be at least four times (twice vertically and horizontally) the resolution of the liquid crystal panel to be inspected.
For example, it is necessary to use a CCD camera with 4 million pixels for inspection of an XGA (1024 × 768 pixels) liquid crystal panel.
[0012]
The time required for capturing from the CCD camera 5 to the defect determination unit (computer) 7 is proportional to the number of pixels.
In the case of a 4 million pixel camera, it takes about 1 second for exposure and data capture.
[0013]
(6) Usually, since it is necessary to capture about 10 images for focusing, the focusing time needs about 10 seconds.
(7) In the production line, speeding up the inspection is very important, and there is a demand to reduce the above time as much as possible.
[0014]
An object of the present invention is to solve the above-described problems and to provide a liquid crystal panel inspection apparatus that can perform focusing at high speed.
That is, an object of the present invention is to provide a liquid crystal panel inspection apparatus that can perform focusing at high speed by using a camera that captures images at high speed for focus adjustment.
[0015]
[Means for Solving the Problems]
In order to achieve such an object, according to the present invention, in the liquid crystal panel inspection apparatus according to claim 1,
A light source that irradiates light onto the liquid crystal panel to be inspected, a pattern generation unit that forms a predetermined inspection image on the liquid crystal panel, and a projection optical unit that projects light optically modulated by the liquid crystal panel onto the screen And a liquid crystal panel inspection apparatus comprising a first camera for detecting an image on the screen,
A second camera that captures at least a part of an image on the screen and has a higher frame rate than the first camera, and a focus adjustment unit that adjusts the focus of the projection optical unit based on a signal from the second camera It was characterized by comprising.
[0016]
According to a second aspect of the present invention, in the liquid crystal panel inspection apparatus according to the first aspect of the present invention, the first camera is rotated with a rotational deviation within the screen surface of the image provided on the first camera. It is characterized by having a rotation adjusting unit for adjusting the position.
[0017]
In Claim 3 of this invention, in the liquid crystal panel test | inspection apparatus of Claim 1 or Claim 2,
A zoom adjustment unit is provided in the first camera and adjusts the size of the image on the screen.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the drawings.
FIG. 1 is an explanatory view of the main part configuration of an embodiment of the present invention.
In the figure, the same symbol structure as in FIG. 2 represents the same function.
Only the differences from FIG. 2 will be described below.
[0019]
Reference numeral 11 denotes a second camera that captures at least a part of an image on the screen 3 and has a higher frame rate than the first camera 5.
In this case, an NTSC camera is used.
[0020]
Reference numeral 12 denotes a focus adjustment unit that adjusts the focus of the projection optical unit 4 based on a signal from the second camera 11.
Reference numeral 13 denotes a rotation adjustment unit that is provided in the first camera 5 and adjusts the rotational deviation of the image on the screen 3 within the screen surface by rotating the first camera 5.
[0021]
A zoom adjustment unit 14 is provided in the first camera 5 and adjusts the size of an image on the screen 3.
[0022]
In the above configuration, the focus adjustment is performed while the projection video is captured by the second camera 11 having a high frame rate instead of the high-resolution camera 5 for inspection.
[0023]
For example, an NTSC camera or the like is used as the second camera 11. An NTSC camera takes about 1/30 second to capture an image.
The NTSC camera is installed so that a part or the whole of the projected image can be captured, and is adjusted in advance so that the screen 3 is in focus.
[0024]
A signal is given to the device under test (liquid crystal panel) from the test pattern generator 6 to project an image with high contrast (such as displaying a white bright spot on a black background) onto the screen 3.
The rotation adjustment unit 13 moves the focus ring of the projection lens 401 little by little, finds a position where the contrast of the captured image of the NTSC camera is maximized, and fixes the projection lens 401 at that position.
[0025]
It is also possible to adjust the zoom of the projection lens 401, the position of the image on the screen, rotation, and the like.
At the time of zoom adjustment, for example, dots are displayed at the four corners, and the zoom adjustment unit is rotated so that the distance between each point on the captured image becomes a specified value.
[0026]
When the projected image is rotated within the screen 3, the image input by the high-resolution camera 5 can be numerically rotated by image processing. The rotation process requires a processing time of several seconds to several tens of seconds for calculation. In order to shorten the time, the high resolution camera 5 is rotated by a motor or the like by the rotation adjusting unit 13 and adjusted by the rotation of the high resolution camera 5 itself.
[0027]
As a result,
(1) When focusing is performed by the image inspection camera 5, for example, adjustment takes 10 seconds or more. However, according to the present invention, a liquid crystal panel inspection apparatus capable of focusing within 1 second is obtained.
Therefore, a liquid crystal panel inspection apparatus that can perform focusing at high speed can be obtained.
[0028]
(2) Since the first camera 5 is provided with the rotation adjustment unit 13 that rotates the first camera 5 to adjust the rotational deviation of the image on the screen 3 within the screen 3 surface. A liquid crystal panel inspection apparatus capable of performing rotation adjustment at high speed is obtained.
[0029]
(3) Since the zoom adjustment unit 14 that is provided in the first camera 5 and adjusts the size of the image on the screen 3 is provided, a liquid crystal panel inspection device capable of performing zoom adjustment at high speed is obtained.
[0030]
In the above-described embodiments, the liquid crystal panel is described as the element to be inspected. However, the present invention is not limited to this, and a projection type display element inspection device or a projection type display element is used. Of course, the present invention can also be applied to the inspection of a projector apparatus.
Furthermore, it is of course applicable to digital mirror devices and CRT projector devices.
[0031]
The above description merely shows a specific preferred embodiment for the purpose of explanation and illustration of the present invention. Therefore, the present invention is not limited to the above-described embodiments, and includes many changes and modifications without departing from the essence thereof.
[0032]
【The invention's effect】
As described above, according to the first aspect of the present invention, the following effects can be obtained.
A liquid crystal panel inspection apparatus capable of performing focusing at high speed is obtained.
[0033]
According to claim 2 of the present invention, there are the following effects.
A rotation adjustment unit that is provided in the first camera and adjusts the rotation deviation of the image on the screen within the screen surface by rotating the first camera is provided, so that the rotation adjustment can be performed at high speed. A liquid crystal panel inspection device can be obtained.
[0034]
According to claim 3 of the present invention, there are the following effects.
Since the zoom adjustment unit provided in the first camera and adjusts the size of the image on the screen is provided, a liquid crystal panel inspection apparatus capable of performing zoom adjustment at high speed can be obtained.
[0035]
Therefore, according to the present invention, it is possible to realize a liquid crystal panel inspection apparatus that can perform focusing at high speed.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram of a main part configuration of an embodiment of the present invention.
FIG. 2 is an explanatory diagram of a main part configuration of a conventional example generally used conventionally.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Liquid crystal panel 2 Lamp 3 Screen 4 Projection optical part 401 Lens 5 CCD camera 6 Inspection pattern generation part 7 Defect determination part 11 Second camera 12 Focus adjustment part 13 Rotation adjustment part 14 Zoom adjustment part

Claims (3)

A light source for irradiating the liquid crystal panel to be inspected,
A pattern generator for forming a predetermined inspection image on the liquid crystal panel;
A projection optical unit that projects light optically modulated by the liquid crystal panel onto a screen;
In a liquid crystal panel inspection apparatus comprising a first camera for detecting an image on the screen,
A second camera that captures at least a portion of the image on the screen and has a higher frame rate than the first camera;
A liquid crystal panel inspection apparatus comprising: a focus adjustment unit that performs focus adjustment of the projection optical unit based on a signal from the second camera. The rotation adjustment part provided in the said 1st camera, The rotation adjustment part which rotates the said 1st camera and adjusts the rotation shift in the said screen surface of the image on the said screen was comprised. LCD panel inspection equipment. 3. The liquid crystal panel inspection apparatus according to claim 1, further comprising a zoom adjustment unit that is provided in the first camera and adjusts a size of an image on the screen.

Images