JPH0658972A - Quality inspecting apparatus for liquid crystal display - Google Patents

Abstract

PURPOSE:To allow quality inspection of a liquid crystal display employing flexible film without depending on visual confirmation. CONSTITUTION:Terminal parts 5, 6, opposite to transparent electrode terminal parts 2, 3, of a liquid crystal display 1 connected with a drive circuit 4, are extended to provide inspection terminal parts. Inspection terminal parts 5, 6 are arranged at an appropriate pitch in order to realize probing common for various types of liquid crystal display 1. The inspection terminal parts 5, 6 thus arranged are then brought into contact with probe pins and driving signals are captured sequentially at respective terminal parts through a scanner 7 and then compared with a standard waveform by means of an analog function tester 9 thus checking the display quality. The inspection terminal parts 5, 6 are eventually cut off and removed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a quality inspection device for a liquid crystal display device using a flexible film.

[0002]

2. Description of the Related Art In a liquid crystal display device, a defect such as a disconnection or a short circuit of a display wiring can be clearly determined by turning on / off an electric signal. Conventionally, the display quality inspection such as delicate brightness of the display screen near the feeding point and the terminal end due to the resistance difference of the ITO film, and the shading of the screen due to the difference in the individual output impedances of the liquid crystal drive circuit is performed at the drive circuit connection terminal part. A drive signal for testing is applied or a drive circuit is connected and then actually driven to visually check the display screen, or a display screen is captured by using an image processing device to compare with the appearance sample. , Judgment of superiority or inferiority.

[0003]

However, there are differences between individuals in the visual judgment of human beings, it takes a lot of time to perform checking work by looking at the screen, and a large number of personnel are required for mass inspection. There's a problem. Further, when the image processing device is used, a very large storage capacity is required to capture the entire screen in the memory, and it is difficult to make the screen photographing environment uniform and reproducible.

The present invention has been made in view of the above conventional problems, and an object of the present invention is to provide a liquid crystal display inspecting apparatus which is not affected by the working environment and has good mass productivity.

[0005]

In order to achieve the above object, a liquid crystal display quality inspecting device according to the present invention has an electrode terminal portion to which a drive circuit of a matrix type liquid crystal display device is connected by extending a part of the inspection terminal. And the inspection probe can be brought into contact with the terminal portion, and means for detecting a drive signal applied to each pixel and the inspection signal and the standard signal are compared to automatically inspect the display quality of the liquid crystal display. And a means.

The liquid crystal display quality inspection device according to the present invention may be arranged such that the detection means detects a drive signal applied to each pixel.

The liquid crystal display quality inspecting apparatus according to the present invention may have a structure in which the extended inspection terminal portions are arranged at a constant interval or are put together in a specific shape to be common.

The liquid crystal display quality inspecting apparatus according to the present invention may be configured such that the extended liquid crystal display quality inspecting apparatus is used and the extended electrode terminal portion is cut after the inspection.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view of a liquid crystal display device to be inspected in the liquid crystal display quality inspection device according to the present invention. In the figure, 1 is a liquid crystal display to be inspected, and 2 and 3 are transparent electrode terminal portions for connecting an actual drive circuit 4. The terminal portions 5 and 6 on the opposite side of the transparent electrode terminal portions 2 and 3 to which the drive circuit 4 is connected are extended by, for example, 5 mm from the bonding portion, and are arranged at a pitch of, for example, 0.25 mm in order to make probing common to each type. As an inspection terminal section. When anisotropic conductive rubber is used, it is preferable to arrange it in a pitch of about 0.35 mm. The probe pins are brought into contact with the arranged inspection terminal portions 5 and 6, and the drive signals of the respective terminal portions are sequentially captured by the scanner.

FIG. 2 shows a block diagram of a liquid crystal display quality inspection device according to the present invention. A scanner 7 and a waveform shaping circuit 8 are connected to the inspection terminal units 5 and 6, respectively, and the waveform captured by the scanner 7 is sequentially compared with a standard waveform by an analog function tester 9. In the figure, 10 is a drive signal generator, and 11 is a control computer.

The segment signal waveform applied to the liquid crystal display 1 by the drive signal generator 10 is as shown in FIG. 3 at the input portion in the case of the simple matrix liquid crystal, and this waveform is the ITO film of the segment wiring. The waveform becomes as shown in FIG. 4 at the terminal end due to the resistance, the capacitance of the liquid crystal material sandwiched between the common electrode of the opposite panel and the like. Here, the rise time, the fall time, and the voltage difference at a certain time appear in the waveform. This rounding of the waveform causes a difference in effective value and affects the display quality. This also applies to common signals.

Therefore, first, the terminal waveform of the display having good display quality is sampled together with the segment wiring and the common electrode and registered in the analog function tester 9 as a standard waveform (for example, the waveform of FIG. 5). The ideal waveform may be calculated and used as a standard waveform. If only the level waveforms of the ON and OFF parts of the segment waveform are extracted by the waveform shaping circuit 8 and only the selected and non-selected level waveforms of the common signal are extracted for comparison, time and voltage can be compared finely.

If the basic waveform deviates from a certain range, it is determined that the display quality is poor. For example, wiring ITO
When the resistance value of the film is partially high, the ON signal waveform is as shown in FIG.
The standard waveform, voltage, and time difference appear. For example, in a liquid crystal display device of 640 × 400 dots, 1/200 duty display, when a liquid crystal driver with an ITO resistance value of 30Ω □ and an output impedance of 1 kΩ is connected and driven, it depends on the process and the liquid crystal material, but the display quality is good or bad. The potential difference of light and shade to be judged is about 100m
Since it is about V, 50% of the rise time (Tr) (Tr
If the potential difference of 50) is 100 mV or more from the standard signal, or if the potential difference of V100 (%) is 100 mV or more, it is determined that the display quality is poor. This is displayed lighter than the whole in the full lighting display state. In addition to the standard waveform, the same comparison may be made for adjacent waveforms to make a determination.

The liquid crystal display, which has completed the lighting display quality inspection, does not require an inspection terminal portion and is cut (FIG. 7). As a result, the display quality after connecting the liquid crystal driving LSI is LS
I and the resistance of the panel connection part can be inspected automatically without visual inspection.

[0015]

As described above, the liquid crystal display quality inspecting apparatus according to the first aspect of the present invention makes the drive signal detecting portion contact a part of the drive circuit wiring of the liquid crystal display terminal portion and inputs the signal of each terminal portion, Since the judgment is made by comparison with the basic waveform or each drive signal, it is possible to eliminate errors due to individual differences as in the case of visual inspection, and the visual inspection process is reduced to achieve an inspection process with good mass productivity. The effect is that you will be able to.

According to the liquid crystal display quality inspecting device of the second aspect, the drive signal applied to each pixel is detected and inspected. Therefore, there is an effect that more detailed automatic inspection can be performed.

The liquid crystal display quality inspecting apparatus according to the third aspect has an effect that it is possible to suppress the increase in the number of inspecting apparatuses by sharing the inspection terminal section.

In the liquid crystal display quality inspecting apparatus of the fourth aspect, the inspection terminal portion is cut after the inspection, so that there is an effect that the outer shape of the liquid crystal display does not become large.

[Brief description of drawings]

FIG. 1 is a perspective view of a liquid crystal display device to be inspected in a liquid crystal display quality inspection device according to the present invention.

FIG. 2 is a block diagram of a liquid crystal display quality inspection device according to the present invention.

FIG. 3 is a waveform diagram of segment signals applied to a liquid crystal display by a drive signal generator in the case of a simple matrix liquid crystal.

FIG. 4 is a terminal waveform diagram of the segment signal waveform of FIG.

FIG. 5 is a standard waveform diagram in which a terminal waveform of a liquid crystal display device having a good display quality is sampled.

FIG. 6 is an observed waveform diagram of a terminal waveform of a liquid crystal display to be inspected.

FIG. 7 is a perspective view corresponding to FIG. 1 showing cutting of the inspection terminal portion.

[Explanation of symbols]

 1 liquid crystal display 2, 3 transparent electrode terminal part 4 drive circuit 5, 6 inspection terminal part 7 scanner 8 waveform shaping circuit 9 analog function tester 10 drive signal generator 11 computer for control

Claims (4)

[Claims] 1. An inspection terminal portion is formed by extending a part of an electrode terminal portion connected to a drive circuit of a matrix type liquid crystal display device, an inspection probe can be contacted with the terminal portion, and the inspection terminal portion is added to each pixel. A liquid crystal display quality inspecting apparatus comprising: a means for detecting a drive signal; and a means for automatically inspecting a display quality of a liquid crystal display by comparing the inspection signal with a standard signal. 2. The detecting means detects a drive signal applied to each pixel.
LCD display quality inspection device. 3. The liquid crystal display quality inspection device according to claim 1 or 2, wherein the extended inspection terminal portions are arranged at a constant interval or are put together in a specific shape and made common. 4. The liquid crystal display quality inspection device according to claim 1, wherein the extended electrode terminal portion can be cut after the inspection.