JPS63246795A - Display tester - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a testing device for a two-dimensional display device.

(Prior Art) When testing a display device, it is important to first determine whether the display function of the device is good or bad. One guideline for determining the quality of this display function is to measure the screen brightness and contrast. Conventionally, in this type of measurement, brightness or contrast tests were performed manually, that is, by inspectors, and a large number of inspectors were required for the test. Furthermore, when testing is done manually, variations in test results and errors in measuring brightness, etc. occur, which ultimately causes a decline in the quality or reliability of the display device. In order to eliminate these shortcomings,
As an example of a highly reliable display test system that can minimize human intervention, there is a device disclosed in Japanese Patent Laid-Open No. 60-53987 and another example in Japanese Patent Laid-Open No. 58-118697. there were. FIGS. 2a and 2b are perspective views of a display test system of one example and another example shown in Japanese Unexamined Patent Publication No. 60-53987 as a prior art. Both sides are test devices that automatically display a test pattern on a display device, measure the display state on the display screen, and are equipped with means for notifying the measurement results to the display device, and the common parts are are given the same symbols.

FIG. 2a shows an example of a display device 1 equipped with a brightness and contrast adjusting hole IJ and -mura, as a device under test. That is, in the example of Figure 2a, this ? Testing machine 3 equipped with an adjustment mechanism 5 and a luminance meter 4 for adjusting the rex-muro
will be established. This makes it possible to adjust the polygon and -me from the tester 3 side, and in addition to automatic measurement of brightness using the brightness meter 4, it is also possible to perform display tests that include the quality of the brightness and contrast adjustment functions of the display device 1. becomes. Testing machine 3 and display device 1
means an external device (not shown) that the display device 1 has.
electrically connected via an interface with the Reference numeral 2 denotes a main body in which a control section of the display device 1 is housed.

Is there another example of the screen in Figure 2 for adjusting brightness, etc.? This shows a configuration for testing the display device 1 without using a frame. In this case, the tester 3 includes only the luminance meter 4.

First, a test display/mother turn display instruction is given from the test machine 3 side via the interface line. The brightness of the main turn displayed on the screen of the display device 1 as a result is measured by the brightness meter 4.

Based on this measurement result, the tester 3 is configured to determine whether the brightness test is good or bad, and to notify the display device 1 of the result.

FIG. 2C is a block diagram showing still another example of a display testing apparatus, which is the apparatus disclosed in the above-mentioned Japanese Patent Application Laid-open No. 118697/1983. The example shown in FIG. 2C is an example of the configuration of an inspection apparatus for a liquid crystal display gray, which is one of the new displays replacing the conventional CRT display gray in recent years. The display test device shown in FIG. 2C displays pixels corresponding to each vertical and horizontal matrix signal line line by line on the image display panel 11 of the matrix display panel. The brightness of the display channel and the brightness when not displayed are photoelectrically converted by the photoelectric conversion element 14 through the condensing lens 13 and compared as electrical signals, and the presence or absence of defects in the displayed pixel portion is automatically determined. In order to determine the actual location, the test signal generator 12 of the four display channels 11 automatically drives the IJ signal lines in sequence, and compares and determines the brightness of the screen to determine the position of the location. It is configured to check the presence or absence of defects and output the results.

FIG. 2d shows an electrical equivalent circuit of the entire liquid crystal display panel. To write the TV image signal to the storage capacitor co of each pixel, select video signal line X, %Xn, f-) signal line Yl-%-Yn according to the location of the screen, and switch This is done by opening and closing the transistor Tr. The voltage of the storage capacitor co of each pixel becomes the applied voltage of the liquid crystal cell LC of each pixel. -vss is the potential of the display silicon integrated circuit substrate, and VCOM is the potential of the common electrode serving as the transparent electrode.

When the video signal line X1 is set to a high level and X2 to Xn are set to a low level, and the r-) signal lines Y1 to Yn are input with vertical scanning signals, x1*y, , Xl・Y, as shown in FIG.
2...The liquid crystal cells in the Xl and Yn portions are driven along the video signal line X (hatched portion).

The method of inspecting pixels along this video signal line It is possible to determine whether there is a defect in the video signal line.

To inspect the image display panel 11, first, since this display panel is of a reflective type, the light source 19 is irradiated from an oblique direction and set at a position with the best contrast. For example, when a high-level signal is input to the video signal line Xl by the drive signal generator 12, the vertical scanning circuit operates normally, and the pixels along the video signal line X1 are also driven. Shining white. This light is collected by condensing lens 1
3, the photoelectric conversion element 14 converts the light into an electrical signal, the amplification section 15 amplifies the light, and sends it to the storage/comparison section 16. The comparison result is sent to the printer 18 as a judgment output, and the video signal line number in this case is received from the line number generation section 17, and written and outputted by the grid/tar 18.

With this configuration, by measuring and comparing the optical signal rail of a known video signal line with and without a drive signal, it is possible to determine whether there is a line defect in that video signal line, and this determination method can be automated. Number of video signal lines
By repeating this process n times, it is possible to automatically detect line defects in the video signal line. Also, fix the vertical scanning signal to some known dart signal line,
In this state, all of the video signal lines X1-Xn are switched to high level and low level, and by comparing the optical signal levels at this time, it is possible to determine whether there is a defect in the dirt signal line.

(Problem to be solved by the invention) As explained above, the conventional method can relatively stably detect line defects and area defects consisting of long lines of multiple pixels due to human visual characteristics. However, it is easy to overlook random defects in pixel units.

This is fine for the final Go/NOGO test, but if you want to feed back the inspection results to the manufacturing process or design process at the early development stage, detailed and statistical data is required. The drawback was that it was difficult to obtain such data.

(Means for Solving the Problems) In order to solve these conventional drawbacks, the present invention collects detailed data for each pixel of a display device, and uses the analysis results of the data to evaluate each pixel. The display device was designed to uniformly scan the entire surface of the display using a sensor having an appropriate resolution.

In other words, the display test device includes a display section, an input/output interface section for exchanging display data with an external device, an instruction input means for instructing the display section to display a test display pattern, and 14 turns for one display. A sensor unit for measuring display conditions including brightness or contrast, a position control unit for changing the relative position between the display unit and the sensor unit, an illumination unit for photographing the display unit, and a test It is equipped with a processing section for displaying 4 turns of display, controlling the entire display, and analyzing the measurement results, and compares the measurement results of 5 display states with preset evaluation criteria to determine whether there is a defect in the display section. In a display testing device, one display section is divided into a plurality of small areas, and a test tJ? is applied to each of the small areas. a means for displaying a turn, a means for photographing with a sensor having a desired resolution smaller than the minimum display unit (pixel) of the display section, and a means for obtaining display state data of the display section, the pixel and a plurality of pixels The structure is configured to have means for automatically determining the presence or absence of defects in each case.

(Function) Since the present invention is configured as described above, the conventional drawbacks are solved, detailed data is collected for each pixel of the display device, and the analysis result of the data is used to evaluate each pixel at an appropriate resolution. By uniformly scanning the entire surface of the display using a sensor with a sensor, it is possible to inspect random defects in pixel units without missing them.

(Example) An embodiment of the present invention will be described with reference to the drawings.

FIG. 1a is a perspective view of an embodiment of the present invention. 21
is a display section of the display, and the display section 21 of the display has a built-in input/output interface section for exchanging display data with an external device. 22 is a display instruction input means, and the display instruction input means 22 is an instruction input means for instructing the display section 21 of the display to display a test display pattern. 23 is a sensor section; sensor section 23.
is a sensor unit for measuring the display state including the brightness or contrast of the displayed main turn. 24 is a position control section, and the position control section 24 is a position control section for changing the relative position between the display section 21 and the sensor section 23. Reference numeral 25 denotes an illumination section, and the illumination section 25 is an illumination section for photographing the display section 22 and obtaining a stable video signal. 26 is a processing section, and the processing section 26 is a processing section for displaying a positioning pattern, controlling the entire system, and analyzing measurement results. In this type of display test equipment, display testing is performed using the display section 2 during the test/mother turn.
1, and this display portion is displayed on the entire surface or part of the display section 21.
The sensor unit 23 having a desired resolution smaller than the minimum display unit (pixel) converts the image into electricity, and compares it with a preset evaluation standard to automatically determine whether there is a defect in the display part. .

FIG. 1C is a front view of an embodiment of the present invention, and FIG.
is also a side view. As mentioned above, in each figure, reference numeral 21 is the display section of the display, and sensor section 23 is for measuring the display state including the brightness or contrast of the displayed pattern.

The position control unit 24 is a position control unit for changing the relative position between the display unit 21 and the sensor unit 23, and includes a sample mounting stage 31 having a function of adjusting the display surface and sensor surface of the test sample parallel to each other. and a rotating part 3 for rotating the sample mounting table 31.
2 and the two orthogonal axes on the two-dimensional plane parallel to the sensor surface are x
, a stage A33 for transferring the sample in the X-axis direction, and a stage B34 for transferring the sample in the Y-axis direction, when the y-axis is
It consists of a surface plate 35 necessary for stable operation of stages A33 and B34. The illumination section 25 is for photographing the display section 21 to obtain a stable video signal, and includes a concentric light emitting section 41 and a shade section 4 for obtaining scattered light.
It consists of 2. Reference numeral 27 denotes a sensor mounting section, and the distance between the sensor mounting section 27 and the sample mounting table 31 can be adjusted. The shielding box 28 is provided to block external light and to set illumination conditions for the sample. The test method for displays using such equipment generally consists of the following initial settings →
Data collection→data processing→disgray evaluation is performed in this order.

(1) Initial settings: Here, as preparations necessary to carry out automatic measurement, the magnification setting of the sensor 23, stage A3
3 and T334 within the movable range, the inclination of the sample mounting table 31 is adjusted, the illumination conditions are set, etc. so that the sample is in focus even when moved within the movable range.

(2) Data collection: The entire surface of the sample is scanned with the effective field of view of the sensor 23 to obtain a video signal for the display unit 21.

Specifically, as shown in FIG. 3, the entire surface of the sample is mapped by mapping the effective field of view 5zaxb (hatched portion) of the sensor 23 to m x n. Furthermore, Fig. 4 shows the relationship between display pixels and sensor elements. If the pitch between the sensor elements is t, the resolution of the sensor is (a/1) x (b/l
). In FIG. 4, 52 represents a disgray pixel, and the size is PxP. Moreover, the broken line represents the pitch (t) between sensor elements.

(3) Data processing: C/The video signal already captured is A.
/D converted and stored in the memory of a processing device (not described or shown here), and at the same time compared with a reference value prepared in advance, it is evaluated by comparison with a threshold value, and the result is also stored. be done.

Various evaluation results are output after being statistically processed and graphed as necessary. In addition, if P/l is not an integer, or due to the alignment position of the sensor element and pixel, etc., there may be a sensor element that only corresponds to a part of the pixel, as shown in the hatched area on the outer periphery of the pixel shown in Figure 4. There are cases where correct evaluation cannot be made. For this reason, in data processing, measures such as an evaluation method using only a stable area excluding the outer periphery of the pixel are taken.

(4) Display evaluation: GO/N0 of Disgray is determined by setting appropriate criteria and selecting data processing results.
Perform GO evaluation, etc.

(Effects of the Invention) As explained above, according to the present invention, detailed luminance data can be obtained for each pixel of the display, and arbitrary evaluation can be performed for each pixel as necessary, providing feedback to the design process and manufacturing process. We have started providing detailed data for the purpose of testing, and can also perform macroscopic sensory tests. Further, the present invention has the effect of providing a general-purpose test device that can be used for evaluating entire display devices such as CRTs and flat displays, as well as two-dimensional images.

[Brief explanation of drawings]

Fig. 1a is a perspective view of the configuration of an embodiment of the present invention, Fig. 1 is a front view of an embodiment of the invention, Fig. 1C is a side view, and Fig. 2a is an example of the prior art. FIG. 2 is a perspective view of the structure of a display test device according to another example of the prior art; FIG. 2C is a perspective view of a display test device of still another example of the prior art. , Fig. 2 d is an electrical equivalent circuit diagram of the entire liquid crystal surface panel of another conventional example, Fig. 2 e is an explanatory diagram showing the positional relationship between the IJ sock line and display pixels, and Fig. 3 is an illustration of the present invention. FIG. 4 is an explanatory diagram showing the relationship between the field of view of the sensor of one embodiment and the entire surface of the sample. FIG. 4 is an explanatory diagram showing the resolution of the sensor of one embodiment of the present invention. 1...Display device, 2...Control unit, 3...Testing machine,
4... Brightness meter, 5... Adjustment mechanism, 6... Brightness & contrast adjustment? Reumu, 11...Image display!
12... Test signal generation unit, 13... Condenser lens, 14... Photoelectric conversion element, 15... Amplification unit, 1
6... Memory/comparison section, 17... Line number generation section,
18... Printer, 19... Light source, 20... Display direction, 21... Display section of display, 22...
Display instruction input means, 23...sensor unit, 24...position control unit, 25...illumination unit, 26...processing unit, 27
...Sensor installation part, 28...Shielding box, 3
DESCRIPTION OF SYMBOLS 1... Sample mounting stand, 32... Rotating part, 33... Stage A, 34... Stage B, 35... Surface plate, 4
1... Luminous body part, 42... Shade part, 51...
Effective field of view of the sensor, 52...pixels. 2o: Display direction 21: Display section 22 of display: Display instruction input means 23: Sensor section 24: Position control section 25: Illumination section 26: Processing section Perspective view of the configuration of an embodiment of the present invention Fig. 1 (0) Book Front view of an embodiment of the invention FIG. 1(b) Side view of an embodiment of the invention FIG. 1(C) A perspective view of the structure of a display test device as an example of the prior art FIG. 2(0) Figure (b) Test signal generating unit A block diagram showing still another example of the display test device of the prior art.
Figure 2 (C) Video line Figure 2 (d) Explanatory diagram showing the positional relationship between matrix signal lines and display pixels Figure 2 (Le)

Claims (3)

[Claims] (1) A display unit, an input/output interface unit for exchanging display data with an external device, an instruction input means for instructing the display unit to display a test display pattern, and a control unit for controlling the brightness or brightness of the displayed pattern. consists of a sensor unit for measuring display conditions including contrast, a position control unit for changing the relative position between the display unit and the sensor unit, an illumination unit for photographing the display unit, and a test display pattern display unit. In a display testing device, which is equipped with a processing unit for controlling the display, overall control, and analyzing the measurement results, and compares the measurement results of the display state with preset evaluation standards to determine the presence or absence of defects in the display unit, means for dividing a display section into a plurality of small areas and displaying a test pattern in each of the small areas; a means for photographing with a sensor having a desired resolution smaller than the minimum display unit (pixel) of the display section; and the display section. 1. A display testing apparatus comprising: means for determining display state data of the pixel, and means for automatically determining the presence or absence of a defect for each of the pixels and for each of a plurality of pixels. (2) The display testing device according to claim (1), further comprising means for shielding the optical system from external light as an illumination section. (3) The display test device according to claim (1), characterized in that the illumination section includes an illumination section of concentric light emitters.