JPH0638247A - Test pattern signal generator for liquid crystal panel - Google Patents

Abstract

PURPOSE:To provide the test pattern signal generator for a liquid crystal display panel executing semi-quantitative evaluation in which dispersion of the evaluation caused by the dispersion 'in the skill of an operator evaluating the characteristic of the liquid crystal display panel is not almost in existence. CONSTITUTION:A display pattern A of a triangle as a base is generated, and the display pattern A having a triangle as a base is driven at an optional speed or at a prescribed set speed. A brightness of the display pattern A and a brightness of a background B are controlled to be an optional brightness or set to a prescribed value. The display pattern A having a triangle as a base has a measure.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal panel test pattern signal generator, and more particularly to a liquid crystal panel test pattern signal generator for easily and semi-quantitatively evaluating response characteristics of a liquid crystal panel.

[0002]

2. Description of the Related Art A conventional example of the present invention will be described. Conventional test pattern signal generators for liquid crystal panels have been adapted to test cathode ray tubes and generate test patterns that evaluate linearity, circularity and resolution.

A test pattern signal generator of this type and a test pattern generated will be described with reference to FIG. As an example, there is a test pattern signal generator that generates a test pattern as shown in FIG. 4A (for example, Test Pattern Signal Generator LCG-406 manufactured by Leader Electronics Co., Ltd.). This displays a black line pattern on a white background, or a white line pattern on a black background. It is provided with a structure for driving the displayed pattern vertically or horizontally. However, the drive speed is not changed. A plurality of line pattern widths are prepared and are variable. The white level voltage and the black level voltage are fixed.

When the displayed pattern is driven rightward, for example, the left side of the pattern is blurred as shown in FIG. 4 (b). The degree of this blur indicates the response characteristics of the liquid crystal panel. As another example, there is a test pattern signal generator that generates a test pattern as shown in FIG. 4C (for example, a test pattern signal generator CB57D manufactured by Shibasoku Co., Ltd.). This is 100% on a black background
It displays a white window pattern. The window pattern to be displayed is driven vertically or horizontally. However, the drive speed is not changed. Do not change the size of the window pattern. The background is only black.

If the displayed window pattern is driven rightward, for example, the left side of the window pattern is blurred as shown in FIG. 4B, as shown in FIG. 4D. The degree of this blur indicates the response characteristic of the liquid crystal panel as in the case of the previous example.

[0006]

In the liquid crystal panel for televisions as well as the liquid crystal panel for OA, the display of moving images is indispensable. Therefore, in the case of testing a liquid crystal panel, it is particularly important to evaluate the response characteristics, and it is desired to evaluate the response characteristics of the liquid crystal panel in the liquid crystal panel assembly line without using complicated optical measurement. Of.

In each of the above examples, when the pattern is driven, a tailing phenomenon occurs on the rear side in the traveling direction, and it is determined how much the tailing phenomenon is during the driving of the pattern. is there. The length of the tail, the shape of the tail, and the degree of the tailing phenomenon are recognized differently by the observer because there is no objective criterion for judgment. The recognition and judgment made by the observer are qualitative and not quantitative. It is difficult to set the judgment standard by using a video signal of a normal moving image or by moving a line as described above or a simple pattern such as a square, a circle or the like.

The present invention provides a test pattern signal generator for a liquid crystal panel which solves the above problems.

[0009]

A display pattern A based on a triangle is provided, and the display pattern A based on a triangle is set at an arbitrary speed or at a set constant speed. The display pattern A based on a triangle is provided with a structure for driving, and a structure for controlling the brightness of the display pattern A and the brightness of the background B to arbitrary values or setting them to a certain constant value. A test pattern signal generator for a liquid crystal panel with a memory was constructed.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described with reference to FIG. A test pattern signal generator for a liquid crystal panel according to the present invention is configured to generate a display pattern A based on a triangle as shown in FIGS. 1 (a), 1 (b) and 1 (c). It has. The display pattern A based on the triangle is driven at an arbitrary speed or at a set constant speed. Also,
This test pattern signal generator also has a configuration for controlling the brightness of the display pattern A and the brightness of the background B to arbitrary values or setting them to a certain constant value. Further, the display pattern A based on the triangle is provided with a memory as a standard for semi-quantification.

As an example of the display pattern A based on a triangle, a display pattern as shown in FIG. 2 can be adopted. This example shows 3 when the figure is observed microscopically.
Although there is no prismatic part, it can be assumed that the whole is triangular when macroscopically observed. When the macroscopic triangle is viewed in the horizontal direction, it is considered that the place where the width changes stepwise corresponds to the memory.

Next, with reference to FIG. 3, a method of evaluating the response characteristic of the liquid crystal panel for a television by the test pattern signal generator of the present invention will be described. The liquid crystal panel for television has a screen size of 120 mm in width × 60 mm in length and is composed of a matrix of 480 × 240 dots. The pitch between dots is 0.25mm (120mm
÷ 480).

Here, the display pattern A of 100% white level which is basically a triangle with respect to the background B of black level is 1 cm.
I tried driving from left to right at a speed of / sec. This 1 cm
Even during driving at a speed of / sec, the display pattern A based on the triangle did not deform until reaching the tip. Since the display pattern A is driven at a speed of 1 cm / sec, it means that the display pattern A is driven at 0.025 sec = 25 msec in terms of a pitch between dots of 0.25 mm. The display pattern A based on the triangle did not deform until the tip even during the driving of
After all, it can be seen that the response characteristic in this case is 25 msec or less.

This time, the display pattern A of white gray of 50% white based on the triangle is driven from the left to the right at the same speed of 1 cm / sec as described above against the background B of the dark gray of 10% white. I tried. In this case, a part of the upper end of the display pattern A was missing during driving, and it was not possible to recognize the memory for 3 dots. This response characteristic is 25msec × 3 = 75ms
You can see that it has decreased to about ec.

With respect to the display pattern A shown in FIG. 3, the response characteristic can be determined by observing the size of the square to disappear.

[0016]

As described above, according to the present invention, by adopting the display pattern based on the triangle, the amount of disappearance of the acute-angled portion of the triangle or macroscopically increases as the display pattern driving speed increases. Since the disappearance amount of the quadrangle forming the triangle increases, the response characteristics can be evaluated semi-quantitatively by focusing on this disappearance amount. And 3
By adding a memory to the display pattern based on the prism, the evaluation becomes easier and more reliable. Also, the response characteristics in various gradation regions can be evaluated by changing the background brightness and the display pattern brightness level.

The present invention particularly employs a display pattern based on a triangle and evaluates the characteristics of the liquid crystal panel from the relationship between the driving speed of the pattern and the shape change of the driven pattern. It is possible to carry out a semi-quantitative evaluation with almost no variation in the evaluation due to the variation in the skill level.

[Brief description of drawings]

FIG. 1 is a diagram showing a display pattern based on a triangle according to the present invention.

FIG. 2 is a diagram showing another example of a display pattern based on a triangle according to the present invention.

FIG. 3 is a diagram for explaining how to evaluate response characteristics by the test pattern signal generator of the present invention.

FIG. 4 is a diagram showing a conventional example of a test pattern.

[Explanation of symbols]

 A Triangle-based display pattern

Claims (3)

[Claims] 1. A structure for generating a display pattern based on a triangle is provided, and a structure for driving the display pattern based on a triangle at an arbitrary speed or at a set constant speed is provided. A liquid crystal panel test pattern signal generator characterized in that 2. The test pattern signal generator for a liquid crystal panel according to claim 1, wherein the brightness of the display pattern and the brightness of the background are controlled to arbitrary values or set to a certain constant value. A test pattern signal generator for a liquid crystal panel, comprising: 3. A test pattern signal generator for a liquid crystal panel according to claim 1 or 2, wherein a display pattern based on a triangle is provided with a memory. Generator.