JP3201007B2 - Inspection apparatus and inspection method for liquid crystal display device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inspection apparatus and an inspection method for a liquid crystal display.

[0002]

2. Description of the Related Art In an active matrix type liquid crystal display device, a plurality of pixels are arranged in a plane, and an image is displayed by selectively driving the pixels. An inspection device is used to detect a defect in a pixel of the liquid crystal display device. The inspection device includes a movable table on which a liquid crystal display device is mounted, an imaging device for capturing an image displayed on the liquid crystal display device, and a lens system. The lens system spatially converts the image displayed on the liquid crystal display device to the same size, that is, expands or reduces the image spatially without changing the aspect ratio of the image, and outputs the image to the imaging device. I do. The imaging device is usually composed of a CCD camera, and its aspect ratio is, for example, 4: 3. Normal CCD
The camera has up to about 400,000 CCD elements.

One pixel of a liquid crystal display device has one or two Cs.
When only a CD element is supported, the following problem occurs. (A) CCD cameras typically have a significant number of defective CCs.
D element is included. Therefore, a defect of a pixel of the liquid crystal display device may not be detected in some cases. (B) Depending on the position of the pixel of the liquid crystal display device mounted on the movable table, the positional relationship between the pixel and the CCD element becomes inappropriate, and the CCD element corresponding to the whole image of one pixel is captured. May not be.

Therefore, in order to detect a defect in a pixel of a liquid crystal display device, it is necessary that as many CCD elements as possible correspond to one pixel of the liquid crystal display device. Also,
The greater the number of CCD elements in the imaging device, the higher the accuracy of the liquid crystal display device as an inspection device.

As a high-resolution CCD camera, HDVS
(High Definition Vision System) type CCD cameras are known. This type of CCD camera has about 10
It has 0 to 2 million CCD elements, and its aspect ratio is 16: 9.

[0006]

SUMMARY OF THE INVENTION CCD of HDVS system
When the camera is used as an imaging device for an inspection device of a liquid crystal display device, the aspect ratio of the liquid crystal display device and the aspect ratio of the imaging device are different. Therefore, as shown schematically in FIG. In the area 30, there is a portion 34 where the image 32 displayed on the liquid crystal display device is not projected.
Occurs. Therefore, part 34 of the effective area of the imaging device
However, there is a problem that the capability of a high-resolution imaging device cannot be utilized.

[0007] Further, it is desired to further improve the resolution of an image displayed on a liquid crystal display device picked up by the image pickup device.

Accordingly, it is an object of the present invention to provide an inspection apparatus and an inspection method for a liquid crystal display device which can effectively utilize an imaging device having an aspect ratio different from that of an image displayed on the liquid crystal display device. It is in.

[0009]

The above objects are achieved by (a) an image pickup device for picking up an image displayed on a liquid crystal display device, and (b) a liquid crystal display device disposed between the liquid crystal display device and the image pickup device. A conversion unit for spatially converting an image displayed on the device into a non-uniform magnification and outputting the converted image to an image pickup device, which can be achieved by the inspection apparatus for a liquid crystal display device of the present invention.

In a preferred embodiment of the inspection apparatus of the present invention, the aspect ratio of the image displayed on the liquid crystal display device is A
_When the aspect ratio of the image pickup device is A ₂ : 1
The conversion means multiplies the image displayed on the liquid crystal display device by m times in one direction and m (A ₂ / A ₁ ) in a direction perpendicular to the direction.
Double and spatially convert and output to the imaging device.

[0011] The conversion means can be composed of, for example, a collimator lens or a cylindrical lens.

Another object of the present invention is to provide a method for inspecting a liquid crystal display device by imaging an image displayed on the liquid crystal display device with an image pickup device for inspecting a liquid crystal display device. The image displayed on the liquid crystal display device is spatially converted to non-equal magnification so that the aspect ratio of the image matches the aspect ratio of the imaging device, and the image is captured by the imaging device for inspection of the liquid crystal display device. The present invention can be achieved by the method for testing a liquid crystal display device according to the present invention.

[0013]

In the inspection apparatus for a liquid crystal display device according to the present invention,
Conversion means for spatially converting an image displayed on the liquid crystal display device into a non-equal magnification and outputting the converted image to an imaging device is provided. Therefore, it is possible to effectively use an effective area where the image can be captured by the imaging apparatus.

[0014]

FIG. 1 schematically illustrates an inspection apparatus for a liquid crystal display device according to the present invention. The inspection apparatus 1 includes a movable table 18 on which the liquid crystal display device 10 is mounted, a light source 16 for illuminating the liquid crystal display device, a conversion unit 12 including a cylindrical lens and a normal lens group, and an HDVS CCD camera. It is composed of an imaging device 14. In addition, a driving circuit for controlling and driving the liquid crystal display device and the imaging device 14
The device for controlling, processing and displaying the output from is not shown.

The liquid crystal display device 10 to be inspected is, for example,
The display effective area is 16 × 12 mm (aspect ratio is 4:
3, ie, A ₁ = 1.33), and 25 × 37.5 μm
m, composed of 480 × 240 pixels. The imaging device 14 has, for example, an imaging effective area of 32 × 18 mm
(The aspect ratio is 16: 9, that is, A ₂ = 1.78), and is composed of 1920 × 960 CCD elements.

The conversion means 12 includes a cylindrical lens whose front and rear surfaces are cylindrical surfaces having generatrix parallel to each other. The cylindrical lens has no refraction in the plane including the generatrix direction,
It has a refracting action in a plane perpendicular to the generatrix. Conversion means 12
The magnification of the cylindrical lens is A ₂ / A ₁ in a plane perpendicular to the generating line.
= 1.33 times. The image emitted from the cylindrical lens is magnified 1.5 times by the lens group (that is, m = 18/1).
2) The light is incident on the imaging device.

With this configuration, nine CCD elements correspond to one pixel. That is, as compared with the case where the image displayed on the liquid crystal display device is spatially magnified to the same magnification as in the related art and imaged by the imaging device,
The triple CCD elements correspond to the pixels of the liquid crystal display device. In addition, inspection of 480 × 240 pixels can be performed in one imaging.

This state is schematically shown in FIGS. 2, 3 and 4. In the liquid crystal display device, pixels are arranged as shown in a plan view in FIG. As shown in FIG. 3A, in a conventional inspection apparatus and inspection method, an image displayed on a liquid crystal display device is spatially converted to the same magnification. FIG. 3A shows the state of this image (for example, an image after one-pixel conversion of one pixel).
At 22. The CCD element is indicated by 24. On the other hand, as shown in FIG. 3B, in the inspection device and the inspection method of the present invention, the image 20 (one pixel is indicated by a broken line) displayed on the liquid crystal display device is spatially non-display. It is converted to the same size. The state of this image (an image of one pixel after the non-uniform conversion) is indicated by reference numeral 22 in FIG. As apparent from FIGS. 3A and 3B, even if the size of the image displayed on the liquid crystal display device is the same, the image captured by the imaging device is 1.33 in the horizontal direction of the drawing. Because it is doubled, the number of CCD elements corresponding to such an image also increases. In FIG. 3, for simplification of the drawing, 6 pixels per pixel are used.
The illustration shows that the CCD elements correspond to each other.

Further, as shown in FIG. 3B, even when the CCD element corresponds to the edge of the image 20 (one pixel is indicated by a broken line) displayed on the liquid crystal display device, such an image is displayed. Is spatially converted to non-uniform magnification, so that the number of CCDs corresponding to the image 22 of one pixel after non-uniform conversion may increase. Further, as shown in FIG. 4A, even when the arrangement of CCD elements corresponding to the pixels of each liquid crystal display device is different for each pixel of the liquid crystal display device, the image of such pixels is spatially non-uniform. By performing the conversion, as shown in FIG. 4B, the arrangement of the CCD elements corresponding to each pixel of each liquid crystal display device can be made the same.

Although the present invention has been described based on the preferred embodiment, the present invention is not limited to this embodiment. The number of pixels, the size of the effective display area, and the aspect ratio of the liquid crystal display device, or the number of CCD elements, the size of the effective image area, and the aspect ratio of the imaging device are examples and can be changed as appropriate.

As a conversion means, instead of a cylindrical lens,
Any means can be used as long as the means can spatially convert the image to a non-equal magnification, such as a collimator lens.

Although the arrangement pattern of the color filters has been described as a triangle type, the present invention is not limited to this, and may be a mosaic type, a stripe type, or a four-pixel arrangement type. The driving method of the liquid crystal display device is arbitrary.

Depending on the size of the display effective area of the liquid crystal display device, the size of the imageable effective area of the image pickup device, and the image conversion magnification of the conversion means, how many times a single liquid crystal display device is inspected by the inspection device. Is determined.

[0024]

According to the present invention, even if an image pickup device having an aspect ratio different from the aspect ratio of an image displayed on the liquid crystal display device is used, the effective area in which the image pickup device can take an image can be effectively used. Even when the aspect ratio of the image displayed on the liquid crystal display device varies widely depending on the liquid crystal display device, it is only necessary to change the conversion means, and it is always possible to perform imaging with the aspect ratio of the imaging device. Therefore,
The size of the image to be imaged can be made constant without depending on the liquid crystal display device, and the software for testing the liquid crystal display device can be unified.

When the liquid crystal display device is applied to a television, the number of scanning lines in the vertical direction is constant (for example, 240 × (R
GB)), the number of pixels in the vertical direction of the liquid crystal display device is constant. However, for example, in a clear vision system, the number of pixels in the horizontal direction tends to increase.
When the number of pixels in the horizontal direction increases, the present invention can further exert its effect by converting the image displayed on the liquid crystal display device to non-uniform magnification in the horizontal direction.

[Brief description of the drawings]

FIG. 1 is a schematic view of an inspection device for a liquid crystal display device of the present invention.

FIG. 2 is a diagram illustrating an example of an arrangement pattern of color filters of a liquid crystal display device.

FIG. 3 is a diagram showing a relationship between an image picked up by an image pickup device and a CCD element in the present invention and a conventional inspection device and inspection method.

FIG. 4 is a diagram showing a relationship between an image picked up by an image pickup device and a CCD element in the present invention and a conventional inspection device and conventional inspection method.

FIG. 5 is a diagram for explaining a problem in a conventional inspection device for a liquid crystal display device.

[Explanation of symbols]

 Reference Signs List 1 inspection device for liquid crystal display device 10 liquid crystal display device 12 conversion means 14 imaging device 16 light source 18 movable table 20 one pixel 22 displayed on liquid crystal display device 22 image after one pixel is spatially converted 24 CCD element Reference Signs List 30 Effective area that can be imaged by imaging device 32 Image displayed on liquid crystal display device 34 Portion that does not contribute to imaging by imaging device

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G02F 1/13 101 G06T 1/00

Claims (3)

(57) [Claims] (A) An image of an image displayed on a liquid crystal display device.
An imaging device having an aspect ratio different from the spectration ratio and capturing an image displayed on the liquid crystal display device; and (b) an image display device arranged between the liquid crystal display device and the imaging device for displaying the image displayed on the liquid crystal display device. spatially converted into non-equal-magnification, liquid
Multiple CCD elements correspond to one pixel of the crystal display device
A conversion device for emitting light to an imaging device as described above . 2. When the aspect ratio of the image displayed on the liquid crystal display device is A ₁ : 1 and the aspect ratio of the image pickup device is A ₂ : 1, the conversion means converts the image displayed on the liquid crystal display device. , M times in one direction, m (A ₂
2. The inspection apparatus for a liquid crystal display device according to claim 1, wherein the light is spatially converted by a factor of / A ₁ ) and emitted to an imaging device. 3. A method for inspecting a liquid crystal display device by imaging an image displayed on the liquid crystal display device with an imaging device for inspecting a liquid crystal display device, wherein the aspect ratio of the image displayed on the liquid crystal display device is determined. The image displayed on the liquid crystal display device is spatially converted to non-equal magnification so as to match the aspect ratio of the imaging device, and the liquid crystal display
A liquid crystal display device inspection method, wherein an image is taken by a liquid crystal display device inspection imaging device so that a plurality of CCD elements correspond to one pixel of the device.