JP3087098B2 - Method for detecting position and rotation angle of display pixel of liquid crystal display panel - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for detecting a position and a rotation angle of a display pixel formed on a liquid crystal display panel.

[0002]

2. Description of the Related Art Conventionally, when a lighting inspection of a liquid crystal display panel is performed using a CCD camera, the entire liquid crystal display panel is
When it is within the field of view of the CD camera, the alignment mark printed on the liquid crystal display panel is taken in by the CCD camera, the difference from the reference position previously input to the image processing device is calculated, and XYθ is calculated based on the result. This is performed after driving the table (inspection table) and setting the liquid crystal display device at the reference position. If the liquid crystal display panel does not fit within the field of view of the CCD camera, an alignment mark is provided for each area within the field of view of the CCD camera, and the above-described alignment is repeated for each area.

[0003]

However, in each of the conventional methods, a process of printing and drying the alignment mark is required, and drive control of the XYθ table (inspection table) takes time. Was inefficient. In addition, the driving of the XYθ table (inspection table) has a drawback that errors are increased due to the influence of mechanical accuracy.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional drawbacks, and aims to provide a method capable of efficiently and accurately detecting the position and rotation angle of a display pixel of a liquid crystal display panel. Is what you do.

[0005]

One of the methods for detecting the position and rotation angle of a display pixel of a liquid crystal display panel according to the present invention is a liquid crystal display in which display pixels are arranged at predetermined intervals in a row direction and a column direction. A lighting signal is supplied to the panel to illuminate a plurality of alignment display pixels including at least a diagonal corner area of the liquid crystal display panel, and the lit position is imaged by a CCD camera and captured by an image processing device. Based on a previously input lighting position of the alignment display pixel, and the number of display pixels between the alignment display pixels or the interval between the display pixels, the position and rotation angle of each display pixel formed on the liquid crystal display panel are determined. Saishi to seek,

[0006] Before Symbol display pixel alignment, when put that one in the CCD camera field of view, display pixels for other alignment is outside the field of view of the CCD camera, turn-on position of the one of the alignment display pixels Then, at least one of the liquid crystal display panel and the CCD camera may be moved in the X-axis direction or the Y-axis direction by a predetermined amount to capture the lighting position of another alignment display pixel.

In addition, another one of the methods for detecting the position and rotation angle of a display pixel of a liquid crystal display panel according to the present invention is a liquid crystal display panel in which display pixels are arranged at predetermined intervals in a row direction and a column direction. A plurality of alignment display pixels are lit in a visual field section obtained by dividing the display area of the liquid crystal display panel into a plurality of visual field ranges of the CCD camera, and the lit position is imaged by the CCD camera. Each of the displays formed on the liquid crystal display panel based on the lighting positions of the alignment display pixels input in advance and the number of display pixels between the alignment display pixels or the interval of each display pixel number. The position and the rotation angle of the pixel are obtained.

[0008]

According to the above method, since the display pixels for alignment can use the display pixels of the liquid crystal display panel, it is not necessary to form an alignment mark by printing.
In addition, since there is a possibility that it is possible to omit driving control of the liquid crystal display panel to match the reference position, efficiency and accuracy can be improved.

That is, the present invention can be applied to a case where the entire liquid crystal display panel does not fall within the field of view of the CCD camera.
Even on a large screen, the position and the rotation angle of the display pixel of the liquid crystal display panel can be detected efficiently and with high accuracy.

[0010] Incidentally, these methods are both but is intended to light the alignment display pixels at a plurality of locations including a corner region on at least a diagonal of the liquid crystal display panel, contrast, claim 2 The described method is different in that a plurality of alignment display pixels are turned on in a visual field section obtained by dividing a display area of a liquid crystal display panel into a plurality of visual field ranges of a CCD camera. The position and rotation angle of the display pixel can be detected with high accuracy.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment according to the present invention will be described below with reference to the drawings. FIG. 1 shows an apparatus and a circuit configuration suitable for implementing the present invention. The inspection table 1 is mounted so as to be slidable in two X and Y directions orthogonal to each other and to be rotatable in a horizontal rotation angle θ direction, and a liquid crystal display panel 5 is mounted on an upper surface thereof. Note that the inspection table 1 is provided with an opening 1 a at a portion corresponding to the display area of the liquid crystal display panel 5, and a backlight 2 is disposed below the inspection table 1. Light is applied to the liquid crystal display panel 5 through the opening 1a of the inspection table 1.

An unloader 3 for removing the measured liquid crystal display panel 5 from the inspection table 1 and a loader for mounting a new measurement liquid crystal display panel 5 on the inspection table 1 are provided on the left and right sides of the inspection table 1. Further, a prober 6 for turning on the liquid crystal display panel 5 connected to the connection terminal of the liquid crystal display panel 5 is disposed on the side of the inspection table 1. Above, a CCD with photo cells arranged in a matrix
A camera 7 is arranged, which captures the lighting brightness of the liquid crystal display panel 5.

The CCD camera 7 has an AC or AD
An image processing device 8 having a converter 9, an arithmetic circuit 10, an image memory 11, and a display circuit 12 is connected. Thus, the other CCD cameras 7 except the liquid crystal display panel 5
The image processing device 8 and the like are mounted in relation to each other so as to constitute one lighting inspection device. Next, the liquid crystal display panel 5 will be described.
Is a full color display and an active matrix type,
As is well known, a thin-film transistor arranged in a matrix, a transparent pixel electrode connected to a source electrode of each thin-film transistor, and a data line and a gate line connected to a gate electrode and a drain electrode of each thin-film transistor are formed. A liquid crystal is sealed between one transparent substrate and another transparent substrate on which R, G, and B color filters and a common electrode are arranged in a mosaic shape corresponding to each transparent pixel electrode. ing.

Each of the transparent pixel electrodes serves as a display pixel for one dot. The pixel electrodes located at four corners on both diagonal lines of the liquid crystal display panel 5 are used as alignment cover pixels. As will be described later, when detecting the position and the rotation angle of the display pixel, only the four alignment display pixels are turned on, and the other display pixels are turned off.

Next, a method of detecting a display pixel will be described.
The liquid crystal display panel 5 is supplied thereon and is set at a predetermined position. Thereafter, a prober 6 is connected to the liquid crystal display panel 5 to supply a drive signal for turning on only four alignment display pixels. FIG. 2 shows a state where the alignment display pixels M1 to M4 are turned on. The alignment display pixels M1 to M4 are turned on and off together with other display pixels during normal display, but may be turned on only at the time of detection. The colors of the illuminated display pixels M1 to M4 are R (red), G (green), B
(Blue), and different colors may be lit instead of the same color. However, in any case, it is important to prevent misalignment by forming all the display pixels at the same time using the same mask, both for alignment and for others.

The lighting of the alignment display pixels M1 to M4 is captured by the CCD camera 7. in this case,
The liquid crystal display panel 5 is set at a predetermined position on the inspection table 1 by the loader 4 so as to be within the field of view of the CCD camera 7. Alignment display pixel M1
M4 is turned on when the alignment display pixels M1 to M4 are turned on.
Is sent to the image processing device 8 as a video signal via the photocell of the CCD camera 7 located corresponding to the image data.

In the image processing device 8, the sent video signal is digitized by the AC or AD converter 9 and stored in the image memory 11. Then, the image memory 11 is directly accessed by the arithmetic circuit 10 and the image memory 1 is accessed.
The position of the alignment display pixel is determined based on the timing stored in 1. Further, the rotation angle of the liquid crystal display panel 5 is calculated by calculation based on the position information.

Alignment display pixels M1, M2, M
The distance between M3 and M4, that is, the reference distance X0 in the X direction and the reference distance Y0 in the Y direction are input to the image processing device 8 in advance, and are compared with the measured value X1 in the X direction and the measured value Y1 in the Y direction. Is used to calculate the rotation angle θ of the liquid crystal display panel 5. At this time, as described above, the alignment display pixels and the other display pixels are formed using the same mask, and the distance between the alignment display pixels M1 to M4 does not change. Determined with high precision.

Next, the position of each display pixel is detected. After the rotation angle θ of the liquid crystal display panel 5 is calculated, the position of each display pixel is calculated and corrected with reference to the Xa axis and the Ya axis rotated by θ from the X axis and the Y axis. Therefore, the number of display pixels disposed between the alignment display pixels M1 to M4, the length of one side of each display pixel, the interval, and the like are input to the image processing device 8. After detecting the rotation angle of the liquid crystal display panel 5 and the position of each display pixel in this way, if necessary, a photocell corresponding to each display pixel of the photocell of the CCD camera 7 corresponding to each display pixel is calculated. Is determined by This is very important for accurately performing a lighting test or the like of each display pixel.

In the first embodiment described above, the entire liquid crystal display panel 5 is within the field of view of the CCD camera 7. However, in order to detect the position and the rotation angle of the surface pixels with high precision, the CCD camera is required. It is necessary to reduce the reduction ratio of the condenser lens of No. 7. However, in this case, the entire liquid crystal display panel 5 does not fit within the field of view of the CCD camera 7. In such a case, the detection method according to the present invention
The present invention is also applicable to a case where the entire liquid crystal display panel 5 does not fit within the field of view of the CCD camera 7, and such a second embodiment will be described below.

Reference numeral 15 in FIG. 3 denotes a display area of the liquid crystal display panel 5. The length of the display area 15 in the row and column directions is four times as long as the field of view of the CCD camera 7. doing. In order to detect the position and the rotation angle of the display pixel of the liquid crystal display panel 5, first, the liquid crystal display panel 5
Is set in the field of view of the CCD camera 7. Then, the lit alignment display pixel M1 is captured by the CCD camera 7. Next, the liquid crystal display panel 5 or the CCD camera 7 is relatively moved by X0 so that the visual field section 15B is within the visual field of the CCD camera 7, and the lit alignment display pixel M2 is captured. Further, the liquid crystal display panel 5 or the CCD camera 7 is relatively Y
0, the field of view section 15C is moved into the field of view of the CCD camera 7, and the lit alignment display pixel M4 is captured.

As a result, the positions of the alignment display pixels M1, M2, and M4 captured by the CCD camera 7 can be detected, and the actually measured values X1 and Y1 with respect to the reference distances X0 and Y0 are obtained. Similarly to the above, the position and the rotation angle of each display pixel can be detected. Then, after that, a predetermined visual field section of the liquid crystal display panel 5 is positioned within the visual field of the CCD camera 7, and a lighting inspection is performed.
Inspection of uneven display is performed.

In this embodiment, the inspection table 1
Although the drive is controlled in the direction and the Y direction, the drive is performed only once and the drive of the rotation angle is not required, so that it is much more efficient than in the past. It should be noted that the alignment display pixels can be lit only at two diagonal points M2 and M4. Further, in the above-described embodiment, the liquid crystal display panel 5 is a full-color display. However, the measurement method of the present invention can be applied to a monochrome or monochrome display and also to a reflection type.

Next, a third embodiment will be described.
In this example, as shown in FIG. 4, a plurality of display areas 15 of the liquid crystal display panel 5 are divided into a plurality of fields of view of the CCD camera 7 (for example, within a field of view 15A). Alignment display pixels (for example,
The four alignment display pixels M11 to M14) are turned on, the lighted positions are imaged by the CCD camera 7 and taken into the image processing device 8, and the lighting positions of the alignment display pixels input in advance and the alignment display pixels The position and the rotation angle of each display pixel formed on the liquid crystal display panel 5 are obtained based on the number of display pixels between them or the interval between the numbers of display pixels.

That is, the first visual field section 15 A of the liquid crystal display panel 5 is set within the visual field of the CCD camera 7. Then, the alignment display pixels M11 to M14 in the lighting state are captured by the camera 7, and each display pixel is detected. As a result, the positions of the alignment display pixels M11 to M14 captured by the CCD camera 7 are detected, and the actual measurement values X1 and Y1 with respect to the reference distance are obtained. The position and the rotation angle can be detected.

Subsequently, the CCD camera 7 is moved without driving the inspection table 1 to move a predetermined field section of the liquid crystal display panel 5 (for example, a field section adjacent to the right side of the field section 15A) with the CCD camera. 7 and then similarly, the position and the rotation angle of the display pixel in each of the visual field sections are successively detected, and lighting inspection, display unevenness inspection, and the like can be performed.

When positioning a predetermined field section of the liquid crystal display panel 5 in the field of view of the CCD camera 7, C
Although the inspection table 1 may be driven without moving the CD camera 7, it is preferable to move the CCD camera 7 without driving the inspection table 1, thereby enabling efficient and highly accurate detection. I do. Note that at least two alignment display pixels are lit in each field section.
, For example, M12 and M14, M11 and M14, M11
And M12, etc.

[0028]

As described above, since the present invention utilizes the display pixels for alignment, the steps of printing and drying the alignment marks can be omitted. Further, in the case of using the alignment display pixels at least in the corner regions on the diagonal line of the liquid crystal display panel, even if a step of driving and controlling the liquid crystal display panel to be aligned with the reference position is required, it is performed only once. Therefore, the position and the rotation angle of the display pixel of the liquid crystal display panel can be efficiently and accurately detected.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a schematic configuration of an apparatus for detecting a position and a rotation angle of a display pixel formed on a liquid crystal display panel of the present invention.

FIG. 2 is a plan view showing a lighting state of an alignment display pixel of the liquid crystal display panel shown in FIG.

FIG. 3 is a diagram for explaining a detection method when the entire liquid crystal display panel shown in FIG. 1 does not fit in the CCD camera.

FIG. 4 shows a plurality of alignment display pixels M in a visual field section.
It is a top view which shows the aspect which lights 11-M14.

[Explanation of symbols]

Reference Signs List 1 inspection table 2 liquid crystal display panel 7 CCD camera 8 image processing device 11 image memory 15 display area of liquid crystal display panel M1 to M4 alignment display pixel M11 to M14 alignment display pixel 15A to 15C

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Masanori Akita 1-45-1, Oe, Otsu City, Shiga Prefecture Toray Engineering Co., Ltd. (72) Inventor Takashi Masuda 5 Casio Computer at 2951 Ishikawacho, Hachioji City, Tokyo (56) References JP-A-64-2096 (JP, A) JP-A-5-27704 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G02F 1 / 13 101

Claims (2)

(57) [Claims] 1. Display images at predetermined intervals in a row direction and a column direction.
A lighting signal is supplied to the liquid crystal display panel on which the elements are arranged,
At least a corner area on a diagonal line of the liquid crystal display panel
Illuminates multiple alignment display pixels, including
The lighting position of is captured by a CCD camera and captured by the image processing device.
Lighting of the alignment display pixels input in advance
Position, and the number of display pixels between the display pixels for alignment or
Formed on the liquid crystal display panel based on the interval between each display pixel
When calculating the position and the rotation angle of each of the displayed display pixels, when one of the alignment display pixels is within the field of view of the CCD camera, the other alignment display pixel is C
After capturing the lighting position of the one alignment display pixel that is outside the field of view of the CD camera, at least one of the liquid crystal display panel and the CCD camera is moved by a predetermined amount in the X-axis direction or the Y-axis direction, and position and rotation angle detecting method of the display pixel of the liquid crystal display panel you characterized by incorporating the lighting position of the alignment display pixels. 2. A lighting signal is supplied to a liquid crystal display panel in which display pixels are arranged at predetermined intervals in a row direction and a column direction,
A plurality of alignment display pixels are turned on in a field of view obtained by dividing the display area of the liquid crystal display panel into a plurality of fields of view of a CCD camera, and the lighting position is captured by a CCD camera and taken into an image processing device. A position and a rotation angle of each display pixel formed on the liquid crystal display panel are obtained based on a lighting position of the alignment display pixel input in advance and the number of display pixels between the alignment display pixels or an interval between the display pixels. A method of detecting a position and a rotation angle of a display pixel of a liquid crystal display panel.