JPH09274163A - Inspection method for liquid crystal panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make the detecting of after-images of a liquid crystal panel quick and correct by arrabging black display areas and white display areas in a chequered pattern in the screen of the liquid crystal panel and detecting after- images on the screen while inverting receptive display areas on the screen alternately. SOLUTION: After-images on the screen of the liquid crystal panel are detected by displaying black simply areas being minimum multilevel colors and white display areas being maximum multilevel colors as the chequered pattern on the screen of the liquid crystal panel and by inverting the black display areas and the whit display areas on the screen of the liquid crystal panel. In this case, in the dot matrix liquid crystal panel, one pixel is constituted on three dots of red(R), green(G), blue(B) and the three dots of R, G, B are constituted in a stripe shape and the white display areas and the black display areas are arranged in the chequered pattern and they are alternately inverted. Moreover, a changeover for inverting the black display areas and the white display areas on the screen of the liquid crystal panel is performed in an arbitrary timing.

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 inspection method for inspecting an afterimage on the screen of a liquid crystal panel.

[0002]

2. Description of the Related Art FIG. 5 is a schematic diagram showing a structure of a liquid crystal panel on which a column driving integrated circuit, a row driving integrated circuit and a printed circuit board are mounted. In FIG. 5, a mother substrate (liquid crystal panel substrate) 1 is a TAB (Tape Automated Bonding) 2a-
2j is connected to the column driving integrated circuits 3a to 3j,
The column driving integrated circuits 3a to 3j are connected to the printed boards 4a and 4b via the TABs 2a to 2j, and the column driving integrated circuits 3a to 3e send the column signals of odd columns to the column driving integrated circuit 3.
f to 3j respectively supply the column signals of even columns to the mother substrate 1. The mother board 1 is TAB5.
The row driving integrated circuits 6a and 6b are connected via a and 5b, and the row driving integrated circuits 6a and 6b are connected to the printed circuit board 7 via TABs 5a and 5b.
Reference numerals a and 6b respectively supply row signals to the mother board 1. A liquid crystal panel is formed with the above configuration. In this liquid crystal panel, as described above, the column drive integrated circuits 3a ...
3j and one or more row driving integrated circuits 6a, 6b
A column drive signal having a number of L0 (where L0 is a positive integer) gradation display capability is supplied for each column from above or below, or from either the above or below.

FIG. 6 is a schematic view showing an example of a pixel array (dot array of red (R), green (G), blue (B)) of a dot matrix liquid crystal panel. In FIG. 6, line (i) is used as an example.
18 rows (X1 to X18) of dots are shown in the direction, and 18 rows (S1 to S18) of dots are shown in the column (j) direction, that is, 18 × 18 dots. The R, G, and B symbols shown in each dot indicate the color of the color filter corresponding to each dot. In this dot matrix liquid crystal panel, one pixel is composed of three dots of R, G and B, and three dots of R, G and B are formed in a stripe shape.

[0004]

In recent years, the liquid crystal panel market as described above has been expanding rapidly, and each company is making efforts to reduce costs and further improve production efficiency. In particular, the issue of improving production efficiency is the inspection process of liquid crystal panels, which currently depends on human beings such as visual inspection by inspectors. It is a situation where they are seeking or improving their abilities.

Among the inspection methods for such a liquid crystal panel,
A detection method for detecting the afterimage phenomenon of a liquid crystal panel has not been established, which has led to a significant increase in inspection man-hours, and there has been a demand for a new inspection method with improved detection ability without increasing the inspection man-hours. The afterimage phenomenon of the liquid crystal panel means that in the liquid crystal panel, each dot is changed from a white display state shown in FIG. 3 (a stripe-shaped RGB dot is driven to the maximum gradation) to a black display state shown in FIG. When the display changes to (a state where each stripe-shaped RGB dot is driven with the minimum gradation), an inverse tilt domain is formed in the liquid crystal layer around each dot that constitutes a pixel, and A white display area remains in some pixels, that is, for each dot, most of the dot area and the minimum gradation are changed when the maximum gradation drive state is changed to the minimum gradation drive state. It means that the state changes to a driving state (black display state) but remains in a part (peripheral portion) of the dot area in a state other than the minimum gradation driving. In FIG. 4, a portion is a black display area and b portion is an afterimage portion.

Here, the afterimage phenomenon of the liquid crystal panel is not directly related to the color display by RGB, so that it will be explained using a general liquid crystal panel. In other words, a liquid crystal panel is like an optical shutter that controls the amount of light transmitted from a light source by displaying the liquid crystal molecules horizontally or vertically between electrodes corresponding to one dot. , The afterimage phenomenon is explained on the premise of the operation.

An object of the present invention is to provide a method for inspecting a liquid crystal panel which can detect an afterimage phenomenon of the liquid crystal panel without significantly increasing the number of inspection steps.

[0008]

A liquid crystal panel inspecting method according to claim 1 is a dot matrix liquid crystal panel in which one pixel is composed of three dots of red (R), green (G) and blue (B). , R, G, B 3 dots are formed in a stripe shape,
Having one or more column driving integrated circuits and one or more row driving integrated circuits, a column driving signal having a display capability of L0 (where L0 is a positive integer) gradation is provided for each column from above or below or from above. A method of inspecting a liquid crystal panel for detecting an afterimage of a liquid crystal panel supplied from either of the above and the lower side, wherein a black display area and a maximum gradation color which are the minimum gradation colors are displayed on the screen of the liquid crystal panel. The white display area is displayed in a checkered pattern, and the black display area and the white display area on the screen of the liquid crystal panel are reversed to detect an afterimage on the screen of the liquid crystal panel.

According to this method, the white display region and the black display region of the liquid crystal panel are arranged in a checkered pattern, and the white display region and the black display region are alternately inverted. When observing the afterimage of the liquid crystal panel by visually inverting it to the black display state, the afterimage inspection becomes easier and the detection capability and reliability are higher than when inverting the entire screen from the white display state to the black display state. Can improve and reduce the outflow of defective products to the market.

A method for inspecting a liquid crystal panel according to claim 2 is
In a dot matrix liquid crystal panel, one pixel is composed of three dots of red (R), green (G), and blue (B), and R,
3 dots of G and B are formed in a stripe shape, and have one or more column driving integrated circuits and one or more row driving integrated circuits, and L
A liquid crystal that detects afterimages of a liquid crystal panel to which a column drive signal having a display capability of 0 (where L0 is a positive integer) gradation is supplied from above or below, or from above or below for each column. A method for inspecting a panel, wherein N is a column display unit of n columns in a column direction, and M is a row display unit of m rows in a row direction (where m, n, M, and N are positive integers), and N The display unit of is divided into i0 (where i0 is a positive integer) display area in the column direction, and the display unit of M is divided into j0 (where j0 is a positive integer) display area in the row direction. , Any M
The same gradation is displayed in the display unit of × N, and any M (j) is displayed.
× N (i) and M (j + 1) × N (i + 1) (however,
i and j are black display, which is the minimum gradation color for a display unit of 1 ≦ i ≦ i0, a positive integer satisfying 1 ≦ j ≦ j0, and M (j + 1) × N (i) and M (j ) × N (i +
1) (where i and j are positive integers that satisfy 1 ≦ i ≦ i0 and 1 ≦ j ≦ j0), a state in which white, which is the maximum gradation color, is displayed, and an arbitrary M (j) × N (i) and M (j +
1) × N (i + 1) (where i and j are 1 ≦ i ≦ i0,
The maximum gradation color of white is displayed for a display unit of (1 ≦ j ≦ j0) and M (j + 1) × N.
(I) and M (j) × N (i + 1) (where i and j are 1
An afterimage is detected by alternately switching a display unit of ≦ i ≦ i0, a positive integer satisfying 1 ≦ j ≦ j0 and a state of displaying black which is a minimum gradation color.

According to this method, the white display area and the black display area of the liquid crystal panel are arranged in a checkered pattern, and the white display area and the black display area are alternately inverted. When observing the afterimage of the liquid crystal panel by visually inverting it to the black display state, the afterimage inspection becomes easier and the detection capability and reliability are higher than when inverting the entire screen from the white display state to the black display state. Can improve and reduce the outflow of defective products to the market.

[0012]

Embodiments of the present invention will be described with reference to the drawings. This liquid crystal panel inspection method is a dot matrix liquid crystal panel as shown in FIG. 5 and FIG. 6, and 3 dots of red (R), green (G), and blue (B)
Pixels are formed, three dots of R, G, and B are formed in a stripe shape, one or more column driving integrated circuits and one or more row driving integrated circuits are provided, and L0 (where L0 is a positive integer) A method of inspecting a liquid crystal panel, which detects afterimages of a liquid crystal panel supplied from above or below, or from above or below, for each column of a column drive signal having a gradation display capability. Display a black display area that is the minimum gradation color and a white display area that is the maximum gradation color on the screen in a checkered pattern,
An afterimage on the screen of the liquid crystal panel is detected by reversing the black display area and the white display area on the screen of the liquid crystal panel. Switching for inverting the black display region and the white display region on the screen of the liquid crystal panel is performed at an arbitrary timing. This residual image is visually detected to determine whether the liquid crystal panel is good or bad.

In this case, the checkered pattern display on the liquid crystal panel is as follows. That is, in this liquid crystal panel, the column display unit of n columns in the column direction on the screen of FIG. 6 is N, and the row display unit of m lines in the row direction on the screen is M (where m, n, M, (N is a positive integer), the display unit of N is i0 in the display area in the column direction.
(Where i0 is a positive integer), the display unit of M is divided into j0 (where j0 is a positive integer) display area in the row direction, and the same for any M × N display unit. Display gradation.

Then, any M (j) × N (i) and M
(J + 1) × N (i + 1) (where i and j are 1 ≦ i ≦
i0, a positive integer that satisfies 1 ≦ j ≦ j0) is displayed as black, which is the minimum gradation color, and M (j + 1)
× N (i) and M (j) × N (i + 1) (where i, j
Is a state in which white, which is the maximum gradation color, is displayed for a display unit of 1 ≦ i ≦ i0 and 1 ≦ j ≦ j0, and an arbitrary M (j) × N (i) and M (j + 1). ) × N (i + 1)
(However, i and j are positive integers satisfying 1 ≦ i ≦ i0 and 1 ≦ j ≦ j0), white is displayed as the maximum gradation color, and M (j + 1) × N (i) is displayed. M (j) × N
(I + 1) (where i and j are 1 ≦ i ≦ i0, 1 ≦ j ≦
By visually observing the screen of the liquid crystal panel while alternately switching the state of displaying black, which is the minimum gradation color, with respect to the display unit of (a positive integer satisfying j0) at an arbitrary interval,
Detect the afterimage on the LCD panel.

Hereinafter, in order to detect the afterimage of the liquid crystal panel, when the white display region and the black display region of the liquid crystal panel are arranged in a checkered pattern and the white display region and the black display region are alternately inverted, An example of the screen of the liquid crystal panel will be described based on FIGS. 1 and 2. 1 and 2 show the row side 9
It is a figure which shows the example of an afterimage when the inversion switching of the gradation display by this invention is performed with respect to each dot of the pixel of the liquid crystal panel comprised by the column and the 6 rows side.

In FIG. 1, there are i0 (where i0 is a positive integer) display areas in the row direction according to the display unit indicated by two rows (= N) in the row direction and two columns (= M) in the column direction. , J0 (where j0 is a positive integer) in the column direction, and the same gray scale is displayed in any M × N display unit, and any M (j) × N (i ) And M (j + 1) ×
N (i + 1) (where i and j are 1 ≦ i ≦ i0, 1 ≦ j
A minimum gradation color of black is displayed for a display unit of ≦ j0, and M (j + 1) × N (i) and M (j) × N (i + 1) (where i and j are 1 ≦ i ≦ i
It shows a state in which white, which is the maximum gradation color, is displayed for a display unit of 0,1 ≦ j ≦ j0.

In FIG. 2, a state in which the white display region and the black display region are inverted is the same as that in FIG. 1, that is, an arbitrary M (j) × N.
(I) and M (j + 1) × N (i + 1) (where i, j
Is a positive gradation that satisfies 1 ≦ i ≦ i0 and 1 ≦ j ≦ j0), and white is displayed as the maximum gradation color.
Minimum gradation for display units of (j + 1) × N (i) and M (j) × N (i + 1) (where i and j are positive integers satisfying 1 ≦ i ≦ i0 and 1 ≦ j ≦ j0) It shows a state of displaying a black color. FIG. 2 shows a screen in which a white display portion b remains in a part of the black display area a due to the afterimage phenomenon and an abnormality is detected.

By reversing the state shown in FIG. 2 to the state shown in FIG. 1, it is possible to detect the afterimage of the white display area in the state shown in FIG. According to this embodiment, the black display area and the white display area are arranged in a checkered pattern on the screen of the liquid crystal panel, and the black display area and the white display area are alternately inverted on the screen. When visually inspecting the afterimage above, the afterimage is easier to see and the afterimage inspection is easier than when switching the entire screen to the black display area and the white display area.As a result, the detection capability and reliability are improved. Moreover, the inspection man-hours can be reduced, and the outflow of defective products to the market can be further reduced.

[0019]

According to the liquid crystal panel inspection method of the present invention, the black display regions and the white display regions are arranged in a checkered pattern on the screen of the liquid crystal panel, and the black display regions and the white display regions are formed on the screen. Since the method of alternately inverting and detecting the afterimage on the screen is adopted, the afterimage of the liquid crystal panel can be detected quickly and accurately, and the inspection method is simple.
Very useful in practice.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing an image evaluation pattern for image inspection of a liquid crystal panel according to an embodiment of the present invention.

FIG. 2 is a schematic diagram showing an image evaluation pattern when an abnormality is detected in the image inspection of the liquid crystal panel according to the embodiment of the present invention.

FIG. 3 is a schematic view showing dots of a liquid crystal panel in a white display state of a conventional liquid crystal panel.

FIG. 4 is a schematic diagram showing dots in which an afterimage occurs when switching from a white display state to a black display state.

FIG. 5 is a schematic diagram showing a structure of a liquid crystal panel.

FIG. 6 is a schematic diagram showing a pixel array of a liquid crystal panel.

[Explanation of symbols]

 1 Mother board 2a-2j TAB 3a-3j Column drive integrated circuit 4a, 4b Printed circuit board 5a, 5b TAB 6a, 6b Row drive integrated circuit 7 Printed circuit board

Claims (2)

[Claims] 1. A dot matrix liquid crystal panel, wherein one pixel is composed of three dots of red (R), green (G) and blue (B), and three dots of R, G and B are formed in a stripe shape,
Having one or more column driving integrated circuits and one or more row driving integrated circuits, a column driving signal having a display capability of L0 (where L0 is a positive integer) gradation is provided for each column from above or below or from above. A method of inspecting a liquid crystal panel for detecting an afterimage of the liquid crystal panel supplied from either of the above and the lower side, in which a black display area and a maximum gradation color which are the minimum gradation colors are displayed on the screen of the liquid crystal panel. A liquid crystal panel characterized by displaying a white display area in a checkered pattern, and detecting an afterimage on the screen of the liquid crystal panel by inverting the black display area and the white display area on the screen of the liquid crystal panel. Inspection method. 2. A dot matrix liquid crystal panel, wherein one pixel is composed of three dots of red (R), green (G) and blue (B), and three dots of R, G and B are formed in a stripe shape,
Having one or more column driving integrated circuits and one or more row driving integrated circuits, a column driving signal having a display capability of L0 (where L0 is a positive integer) gradation is provided for each column from above or below or from above. A method for inspecting a liquid crystal panel, which detects afterimages of a liquid crystal panel supplied from either of the lower side and the lower side, wherein n is a column display unit of n columns in a column direction, and m is a row display unit of a row direction. Is M (where m, n, M, and N are positive integers), and the display unit of N is divided into i0 (where i0 is a positive integer) display area in the column direction, and the display unit of M is The display area is divided into j0 (where j0 is a positive integer) in the row direction, the same gray scale is displayed in any M × N display unit, and any M (j) × N (i) and M are displayed. (J + 1) × N (i +
1) (where i and j are positive integers that satisfy 1 ≦ i ≦ i0 and 1 ≦ j ≦ j0), the minimum gradation color is displayed in black, and M (j + 1) × N (i ) And M (j)
× N (i + 1) (where i and j are 1 ≦ i ≦ i0, 1 ≦
(a positive integer that satisfies j ≦ j0), a state in which white, which is the maximum gradation color, is displayed, and an arbitrary M (j) × N (i)
And M (j + 1) × N (i + 1) (where i and j are 1 ≦
White as the maximum gradation color is displayed for a display unit of i ≦ i0 and a positive integer satisfying 1 ≦ j ≦ j0, and M (j +
1) × N (i) and M (j) × N (i + 1) (however,
i and j are positive integers that satisfy 1 ≦ i ≦ i0 and 1 ≦ j ≦ j0), and the state of displaying black, which is the minimum gradation color, is switched alternately to display on the screen of the liquid crystal panel. A method for inspecting a liquid crystal panel, which comprises detecting an afterimage of