JPH07128186A - Inspection instrument for liquid crystal display - Google Patents

Abstract

PURPOSE:To achieve accurate and efficient evaluation of visual angle characteristic of a liquid crystal display quantitatively with a compact construction. CONSTITUTION:Light condensed from a display section of a liquid crystal display 2 with a lens array 4 made up of lens elements arranged in parallel in the main scanning direction of a onedimensional image sensor 5 undergoes a photoelectric conversion with the image sensor 5. The lens array 4 and the image sensor 5 are supported rotatably with respect to the liquid crystal display 2. A rotating shaft 0 is parallel with the main scanning direction of the image sensor 5 and runs through a display section of the liquid crystal display 2 and a condensing area range of the lens array 4 pertaining to the sub scanning direction of the image sensor 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inspection device suitable for evaluating the viewing angle characteristics of a liquid crystal display.

[0002]

2. Description of the Related Art As a device for inspecting a luminance distribution and a pixel defect of a display portion of a matrix type liquid crystal display, FIG.
As shown in, a two-dimensional CCD camera 102 that captures an image of the display unit of the matrix type liquid crystal display 101 is used. In addition, as shown in FIG.
The image sensor 104 includes a unit lens array 103 including a large number of lens elements focused on the display unit 01, and a one-dimensional image sensor 104 that senses light collected by each lens element. There is used a liquid crystal display 101 which is sent in the scanning direction and inspects the luminance distribution and pixel defects of the display portion.

[0003]

In a liquid crystal display, due to the anisotropy of the refractive index of the liquid crystal and the twisted orientation of the TN liquid crystal, for example, the viewing angle for viewing the display unit as shown in FIG. When the surface normal direction is 0 °), the contrast also changes. Therefore, it is also necessary to inspect the change characteristic of the contrast with respect to the change of the viewing angle of the display unit, that is, the viewing angle characteristic.

However, since the conventional liquid crystal display inspecting apparatus inspects from the direction normal to the surface of the display unit, it cannot inspect the visual angle characteristics, and therefore the visual angle cannot be inspected by the human eye. The characteristics were being evaluated. However, it was difficult to evaluate the visual angle characteristics quantitatively and accurately by the inspection with human eyes, and the work efficiency was also poor.

Therefore, as shown in FIG. 5, a two-dimensional CCD is used.
Liquid crystal display 101 imaged by camera 102
It is conceivable to rotate and tilt the stage 105 that supports the stage, but if the liquid crystal display 101 becomes large, the stage rotation and tilt device becomes large. In addition, since the distance between the two-dimensional CCD camera 102 and the display surface of the liquid crystal display 101 is large, the two-dimensional CC
When the D camera 102 itself is rotated and tilted, the display unit of the liquid crystal display 101 is out of the image capturing area.

An object of the present invention is to provide a liquid crystal display inspection device which can solve the above problems.

[0007]

The present invention comprises a one-dimensional image sensor and a lens array composed of lens elements arranged in parallel in the main scanning direction of the image sensor.
In a liquid crystal display inspection device that photoelectrically converts light condensed from a display unit of a liquid crystal display by the lens array by means of an image sensor, means for rotatably supporting the lens array and the image sensor with respect to the liquid crystal display is provided. , Its axis of rotation is parallel to the main scanning direction of the image sensor, passes through the display section of the liquid crystal display, and passes through the center of the condensing area width of the lens array in the sub scanning direction of the image sensor. It is characterized by

[0008]

According to the structure of the present invention, the lens array and the image sensor are arranged parallel to the main scanning direction of the image sensor with respect to the liquid crystal display, pass through the display section of the liquid crystal display, and pass through the sub-unit of the image sensor. By rotating around the axis passing through the center of the condensing area width of the lens array with respect to the scanning direction, the contrast of the liquid crystal display is quantitatively measured from the direction inclining at an arbitrary angle with respect to the normal to the display surface of the liquid crystal display. You can ask. Further, since it is not necessary to rotate and tilt the stage that supports the liquid crystal display, the size of the device does not increase.

[0009]

Embodiments of the present invention will be described below with reference to the drawings.

The inspection apparatus 1 shown in FIGS. 1 and 2 includes a support stage 3 for a matrix type liquid crystal display 2, an erecting equal-magnification lens array 4, and a one-dimensional image sensor 5. The lens array 4 and the image sensor 5 are fixed in their relative positions by being mounted inside the housing 9.

A pulse motor 8 for rotating the stage 3 about a vertical axis 7 via a reduction gear mechanism 6 is provided, whereby the liquid crystal display 2 supported by the stage 3 is provided.
Can be rotationally positioned about the axis 7 perpendicular to the surface of the display unit in 90 ° increments. The reduction gear mechanism 6 is linearly movably attached to the base 10 via a guide rail 16, whereby the liquid crystal display 2 supported by the stage 3 is movable in the sub-scanning direction of the image sensor 5. .

As shown in FIG. 4, for example, the lens array 4 is composed of a large number of lens elements 4a arranged in parallel in two rows along the main scanning direction of the image sensor 5, and between the lens elements 4a in one row. The lens element 4a in the other row is arranged in the. As shown in FIG. 3, the focal point F of each lens element 4 a is aligned with the display section of the liquid crystal display 2 supported by the stage 3 and the photoelectric conversion section of the image sensor 5. The specific focal position of each lens element 4a in the display unit of the liquid crystal display 2 is
In the state where the optical axis of each lens element 4a is perpendicular to the surface of the display section, the position may be, for example, the position of the black matrix which is a component of the display section of the liquid crystal display 2. The lens array 4 collects light from a backlight (not shown) that passes through the display section of the liquid crystal display 2.

The image sensor 5 has photoelectric conversion elements 5a such as amorphous silicon diodes and CCDs arranged in parallel in a row, and each photoelectric conversion element 5a outputs a signal by sensing the light condensed by the lens array 4. Are taken out through the analog switch 5b and the amplifier 5c.

It is not necessary that the number of pixels of the liquid crystal display 2 per unit length, the number of photoelectric conversion elements 5a per unit length, and the number of lens elements 4a per unit length match. Then, the number of lens elements 4a per unit length is made smaller than the number of pixels and photoelectric conversion elements 5a per unit length, and the number of pixels per unit length and the number of photoelectric conversion elements 5a per unit length are substantially equal to each other. Are made equal. By disposing the lens element 4a of the other row between the lens element 4a of the one row, as shown in FIG. 3, each lens of the image sensor 5 in the display section of the liquid crystal display 2 in the direction of the main runner. The condensing area width E of the element 4a partially overlaps with the condensing area width E of the adjacent lens element 4a, so that there is no omission in inspection.

The housing 9 to which the lens array 4 and the image sensor 5 are attached is rotatably supported by a pair of columns 12a and 12b via a pair of support shafts 11a and 11b, and each column 11a and 11b is the base. It is fixed at 10. Each support shaft 11a,
The axis O of 11b is common, is parallel to the main scanning direction of the image sensor 5, passes through the display section of the liquid crystal display 2,
As shown in FIG. 4, it is supposed to be located at the center between a line O ′ connecting the focal points of the lens elements 4a in one row and a line O ″ connecting the focal points of the lens elements 4a in the other row. Thereby, the lens array 4 and the image sensor 5 are parallel to the main scanning direction of the image sensor 5, pass through the display part of the liquid crystal display 2, and the condensing area width of the lens array 4 in the sub scanning direction of the image sensor 5. It is rotatable about an axis O passing through the center of R. One of the support shafts 1
A pulse motor 14 is connected to 1a via a reduction gear mechanism 13, and the rotation of the pulse motor 14 enables the lens array 4 and the image sensor 5 to be rotationally positioned about an axis O. Positionable rotation angle range θ
Is ± 6 when the state in which the optical axis of each lens element 4a is parallel to the normal line L to the surface of the liquid crystal display 2 is ± 6.
It is preferably 0 ° or more.

As the lens array 4 rotates about the axis O of the support shafts 11a and 11b, the focal position of each lens element 4a is such that the optical axis of each lens element 4a is the surface of the display portion of the liquid crystal display 2. Since the lens element 4a is displaced from a position perpendicular to the lens element 4a, the diameter of each lens element 4a is reduced to reduce the distance between the optical axis of the lens element 4a in one row and the optical axis of the lens element 4a in the other row. Therefore, it is preferable to reduce the displacement distance as much as possible to prevent the condensing performance of the lens array 4 from being deteriorated.

According to the above inspection device 1, it is possible to inspect the luminance distribution and the pixel defect of the display portion of the liquid crystal display 2 as in the conventional inspection device. Further, the lens array 4 and the image sensor 5 are connected to the respective support shafts 11a, 1a.
By rotating with respect to the liquid crystal display 2 about the axis O of 1b, the contrast of the liquid crystal display 2
It can be quantitatively obtained from the direction inclining at an arbitrary angle with respect to the normal line of the surface of the liquid crystal display 2.

The present invention is not limited to the above embodiment. For example, although the liquid crystal display is moved in the sub scanning direction of the image sensor in the above embodiment, the lens array and the image sensor may be moved in the sub scanning direction of the image sensor. Further, as the lens array, one having a large number of lens elements arranged in parallel in three or more rows may be used.

[0019]

According to the present invention, the viewing angle characteristics of a liquid crystal display can be quantitatively, accurately and efficiently evaluated with a compact structure.

[Brief description of drawings]

FIG. 1 is a side view for explaining the configuration of an inspection device according to an embodiment of the present invention.

FIG. 2 is a front view of the inspection device according to the embodiment of the present invention.

FIG. 3 is an explanatory diagram of a configuration of an inspection device according to an embodiment of the present invention.

FIG. 4 is a partial plan view of a lens array according to an embodiment of the present invention.

FIG. 5 is a diagram showing a problem of the prior art.

FIG. 6 is a perspective view of a conventional inspection device.

FIG. 7 is a perspective view of a conventional inspection device.

FIG. 8 is a diagram showing viewing angle characteristics of a liquid crystal display.

[Explanation of symbols]

 2 liquid crystal display 4a lens element 4 lens array 5 image sensor O rotation axis

Claims (1)

[Claims] 1. A one-dimensional image sensor, and a lens array composed of lens elements arranged in parallel in the main scanning direction of the image sensor. The lens array images light collected from a display unit of a liquid crystal display. In a liquid crystal display inspection device that photoelectrically converts by a sensor, means for rotatably supporting the lens array and the image sensor with respect to the liquid crystal display is provided,
The rotation axis is parallel to the main scanning direction of the image sensor, and passes through the display section of the liquid crystal display,
In addition, the inspection device for a liquid crystal display is characterized in that it passes through the center of the condensing region width of the lens array in the sub-scanning direction of the image sensor.