JPH03148077A - Apparatus for inspecting driving ic for liquid crystal display - Google Patents

Abstract

PURPOSE:To execute highly reliable inspection automatically at a high speed by projecting light on the picture elements of a driven liquid crystal display panel, and computing the light transmittance of each picture element for the output signal of an IC under inspection. CONSTITUTION:When n picture elements 41 on one line of a liquid crystal panel 4 are driven by n X driving signals outputted from a liquid-crystal-display driving IC 1 which is the IC under inspection through an electrode 12 and the signals from a Y driver 6, the entire group of the picture elements 41 are uniformly illuminated with a lighting system 7. The images of the transmitted light beams 7 are formed on a CD sensor 82 through an image forming lens 81. The sensor 82 decomposes the transmitted light for every picture element 41 and converts it to electrical signals. The electrical signals are sent into a data processing device 9. The device 9 receives the data with regard to the power source level for the IC 1 and the combination of the driving level signals from a signal generator 3, computes the light transmittance of each picture element 41, compares the transmittance with a predetermined standard value and judges the quality of the IC 1. When the inspection is finished, a carrier tape 11 is automatically sent, and the next IC 1 is inspected.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to an inspection device for a liquid crystal display drive (c).

(Prior Art) In recent years, the spread of liquid crystal displays has been remarkable, and liquid crystal displays are widely used as display devices for word processors, personal computers, liquid crystal televisions, and the like. Along with this, the IC that drives the liquid crystal display
Increasingly, advanced performance is required. In particular, drive ICs for liquid crystal televisions are required to have high performance IC characteristics because subtle changes in their output appear in image quality.

By the way, liquid crystal display panels, which are liquid crystal displays, are generally manufactured with drive ICs bonded to them, so
In the manufacturing process, it is necessary to avoid the introduction of defective ICs as much as possible. Therefore, the IC before bonding to the liquid crystal display panel
inspection will play an important role. And conventionally,
The following two methods were used to test this drive IC.

The first method is to use a general-purpose IC tester that electrically checks the drive output of the IC. The second method is to input the drive output of the IC to a liquid crystal display panel of the same type as the liquid crystal display panel to be driven, and visually check the image quality.

The first method allows testing to be performed fully automatically and at high speed, but is expensive. Furthermore, as mentioned above, due to the recent demand for higher image quality, it has recently become necessary to test IC characteristics to a degree that cannot be checked even with an IC tester. That is, it is necessary to check the rise characteristics of the output waveform of the IC, but the rise characteristics vary greatly depending on the connected load.

This load is a capacitive load specific to liquid crystal display panels.
Since the load varies depending on the type of liquid crystal display panel and internal design specifications, it is extremely difficult to test an IC under the same load as when it is actually used. Furthermore, since there are hundreds of output points, it is not economical to check the fast rise characteristics of each output because it takes too much testing time.

The second method is superior to the first method in that it is cheaper and can be inspected under actual usage load conditions, but since it is determined by human visual inspection, its reliability and inspection speed are limited. There is a big drawback.

(Problems to be Solved by the Invention) As mentioned above, in the test method for drive ICs for liquid crystal displays, the first method using a general-purpose IC tester is expensive, and the
However, the second method, which visually checks the image quality by inputting the IC drive output to a liquid crystal display panel, is inexpensive and can be inspected under actual usage load conditions. Although it has the advantage of being able to do so, it lacks reliability and has the problem of slow inspection speed.

The present invention aims to solve these problems, and provides an inexpensive drive IC for liquid crystal display that can automatically perform high-speed and highly reliable inspection while ensuring the advantages of the second method. The purpose of this invention is to provide an inspection device for the following.

[Structure of the invention]

(Means for Solving the Problems) In order to achieve the above object, the testing device for a drive IC for a liquid crystal display according to the present invention includes a contactor that directly or indirectly probes an electrode of an IC to be tested, and a contactor that directly or indirectly probes an electrode of an IC to be tested. A signal generation source including a power source that drives the IC to be tested through the signal source, the level of the power source and the level of the signal being switchable at appropriate stages and freely combining them in accordance with inspection standards. A generator, a two-dimensional or one-dimensional monochrome liquid crystal display panel in which n pixels arranged in a straight line are driven by n (n is a natural number) output signals of the test target tC; An illumination system that irradiates light to driven pixels among the pixels of the liquid crystal display panel, a photoelectric conversion device that photoelectrically converts the transmitted light from the pixels irradiated by this illumination system, and each output from this photoelectric conversion device. and a data processing device that inputs a photoelectric conversion signal for each pixel and determines the quality of the IC to be inspected by calculating the light transmittance of each pixel of the liquid crystal display panel with respect to the output signal of the IC to be inspected. It is something that

(Function) In the test device for a liquid crystal display drive tC of the present invention, when testing a liquid crystal display drive IC, a contactor is probed to the electrode of the IC to be tested, and a signal generator is connected to the test object via the contactor. Power is supplied to the IC, and a signal for driving the IC to be tested is input. At this time, the power supply level and signal level are appropriately switched and combined in accordance with the inspection standard. As a result, n pixels arranged in a straight line on the liquid crystal display panel are driven by n signals output from the IC to be tested. Along with this,
The illumination system irradiates the driven pixels with light. and,
A photoelectric conversion device photoelectrically converts the transmitted light from the irradiated pixel, and a data processing device inputs the photoelectric conversion signal for each pixel output from this photoelectric conversion device, and converts each pixel to the output signal of the IC to be inspected. The quality of the IC to be inspected is determined by calculating the light transmittance of the IC. In this way, the output abnormality of the liquid crystal display drive IC is checked.

(Example) Hereinafter, an example of an inspection apparatus for a drive IC for a liquid crystal display according to the present invention will be described with reference to FIG.

This testing device includes a contactor 2 for probing a liquid crystal display drive IC 1, which is an IC to be tested;
A signal generator 3, a black and white liquid crystal display panel (monochrome LCD) 4, a flexible printed circuit board (FPC) 5,
It consists of a Y driver 6, a lighting system 7, a photoelectric conversion device 8, a data processing device 9, a control device (not shown), and the like.

Note that the drive ICI in this embodiment is an X driver,
That is, it drives pixels in the horizontal direction of the liquid crystal display panel.

The ICI has a carrier tape 11 that is intermittently conveyed.
TAB (Tape Automated B) is successively ILB (inner lead bonded) and resin sealed.
onding) IC, and the carrier tape 1
1, TAB-ICs are joined at equal intervals. and,
The TAB-IC has n (n is a natural number) drive output lines 12 and power supply/signal source lines 13 as electrodes.

The contactor 2 is connected to the drive output line 1 of the IC1.
2 and the power supply and signal source lines 13 directly or indirectly, and has groups of probers 21 and 22 that contact the drive output line 12 and the power supply and signal source lines I3 so as to be able to move up and down, respectively. ing. The group of probers 21 that come into contact with the drive output line 12 are connected to the liquid crystal display panel 4 through the flexible wiring board 5. Further, the contactor 2 is mechanically controlled by a control device (not shown), and is capable of automatically feeding and positioning the carrier tape 11, and the prober 21.2.
It performs a series of operations such as moving the second group up and down, marking defective ICIs, and drilling holes.

The signal generator 3 is a signal generation source that includes a power source that drives the ICI via the contactor 2, and is capable of switching the level of the power source and the level of the signal at appropriate stages, as well as being capable of inspection. They can be combined appropriately according to standards. The output end of the signal generator 3 is electrically connected to the prober group 22 of the contactor 2 via a wiring 31. Further, the signal generator 3 is controlled by a control signal generated by a control device (not shown).

The liquid crystal display panel 4 has n pixels 41 arranged linearly driven by the n output signals of the ICI, and has pixels arranged two-dimensionally.
The number of pixels in the horizontal direction is n or more. One end of the flexible wiring board 5 is connected in advance to a part of the group of X drive side extraction electrodes 42 of the liquid crystal display panel 4.

As a result, the n drive output lines 1 of the above ■C1
2 are electrically connected to the n X drive side lead-out electrodes 42 of the liquid crystal display panel 4 via the prober 21 group and the flexible wiring board 5, respectively. Further, one of the output signal lines 61 of the Y driver 6 is electrically connected to one Y drive side extraction electrode of the liquid crystal display panel 4 in advance. therefore,
Only 41 groups of pixels in one row of the liquid crystal display panel 4 have the above-mentioned ICI.
It will be driven by

The illumination system 7 irradiates light to n driven pixels 41 among the pixels of the liquid crystal display panel 4, and is composed of a light source 71, a condensing lens 72, a collector lens 73, etc. . In particular, this collector lens 73 is for uniformly illuminating the n pixels 41.

0 The photoelectric conversion device 8 separates and photoelectrically converts transmitted light from the n pixels 41 irradiated by the illumination system 7 for each pixel 41, and includes an imaging lens 81 and a group of photoelectric conversion elements. It is composed of a CCD sensor 82 and the like. Note that the illumination system 7 is masked for illumination so that parts other than the driven pixel group 41 are not illuminated. The imaging lens 81 includes the pixel 41
Upon receiving the transmitted light from the group, this pixel 41 group is
This is to form an image on the sensor surface of the sensor 82. Further, this CCD sensor 82 has sufficient resolution to be able to separately detect each pixel of the pixel 41 group.

The data processing device 9 inputs the photoelectric conversion signal of each pixel 41 outputted from the COD sensor 82 and calculates the light transmittance of each pixel 41 of the liquid crystal display panel 4 with respect to the output signal of the ICI. The quality of this ICI is determined by this. That is, the photoelectric conversion device 8 and the data processing device 9 constitute a photodetection system, and the COD is connected to the input terminal of the data processing device 9.
The output end of the sensor 1 sensor 82 is connected via a wiring 83.

The data processing device 9 is also connected to the signal generator 3 via a wiring 32, and the combination of the power level and drive signal level supplied from the signal generator 3 to the ICI is determined. information.

Note that a peripheral circuit control device (not shown) generates signals other than the output of IC1 necessary to drive the n pixels 41, such as the output signal of the Y driver 6. .

Next, the operation of the inspection apparatus of the above embodiment will be explained.

Each time the carrier tape 11 on which TAB-ICs are joined at equal intervals is conveyed by the contactor 2, the carrier tape 11 is probed with a liquid crystal display drive 1C1, and these ICs 1 are inspected one by one.

When testing one ICI, first, the groups of probers 21 and 22 of the computer 2 come into contact with the drive output line 12 and the power supply/signal source line 13 of this ICI, respectively. Then, power is supplied from the signal generator 3 to the ICI via the contactor 2, and a signal for driving the IC1 is input. At this time, the power supply level and signal level are appropriately switched and combined in accordance with the inspection standard. In this state, the liquid crystal display panel 4 is normally driven. That is, n pixels 41 in one row of the liquid crystal display panel 4 are driven by n X drive signals output from the ICI via the drive output line 12 and Y drive signals output from the Y driver 6. be done.

At the same time, the illumination system 7 uniformly illuminates the entire group of driven pixels 41, as shown by the dashed line. and,
The imaging lens 81 forms an image of the transmitted light from the irradiated pixel group 41 on the sensor surface of the CCD sensor 82 . This C
The CD sensor 82 decomposes the transmitted light into each pixel 41, performs photoelectric conversion, and outputs a photoelectric conversion signal to the data processing device 9.

This data processing device 9 inputs the optical three-electric conversion signal for each pixel 41, and also inputs the signal from the signal generator 3 to the IC.
It receives information about the combination of the power supply level and drive signal level to I, and calculates the light transmittance of each pixel 41 of the pixel 41 group for these. That is, for example IC1
The average transmittance level of the liquid crystal pixels and the variation (deviation) in the transmittance of each pixel 41 are calculated for the drive signal level of the IC.
Determine whether 1 is good or bad.

When one ICI has been tested, the probers 21 and 22 are separated from the carrier tape 11, the carrier tape 11 is automatically fed, and the next ICI is tested.

If there is an output abnormality in the inspected ICI, the information provided from the data processing device 9 is sent to the contactor 2 when the ICI is transferred to a defective marking position provided separately from the blobbing position of the contactor 2. In response, the control device drives the marking mechanism of the contactor 2 to perform marking (or drilling holes 4, etc.) on the defective ICI on the carrier tape 11.

In this way, in this inspection device, the liquid crystal display panel 4
Since an actual load is applied to the ICI and changes in image quality when incorporated into an actual liquid crystal display panel 4 are directly inspected, accurate IC inspection can be performed. In other words, a comprehensive characteristic test including the delicate rise characteristics of ICI can be performed.

Furthermore, since the image quality is inspected by the photoelectric conversion device 8 and the data processing device 9 rather than by human visual inspection, the inspection reliability is high and the inspection speed is fast. Of course, it is also advantageous to perform the entire inspection automatically in terms of speeding up the inspection.

Further, due to its configuration, this testing device dedicated to testing drive ICIs for liquid crystal displays can be made considerably cheaper than conventional IC testers.

Next, another embodiment of the present invention will be described based on FIG. 2.

In the previous embodiment, the illumination system 7 uniformly illuminates the n pixels 41, but in this embodiment, the illumination system 7a uniformly illuminates the 5n pixels in one row of the liquid crystal display panel 4. 41 is scanned and illuminated with a light beam. Correspondingly, the photoelectric conversion device 8a detects the amount of transmitted light from the pixel 41 in synchronization with the scan beam.

The illumination system 71 includes a laser 75 as a light source, a fine light beam optical system 76 that is incorporated into the laser 75 and converts the laser beam into a light beam with a width smaller than the inter-pixel interval of the pixel group 41, and light emitted from the laser beam 75. and a polygon mirror 78 that rotates as shown by the arc-shaped arrow and reflects the reflected light from this mirror 77 toward each pixel 41.
and a lens 79 that refracts the reflected light from the polygon mirror 78 so as to be perpendicular to the liquid crystal display panel 4.

The photoelectric conversion device 81 includes a photocell 85, a lens 86 that refracts transmitted light from each pixel 41 toward the photocell 85, and the like.

The photocell 85 may be a photomultiplier tube or C
Any photoelectric converter can be used, such as a d1i sensor.

6 Then, when inspecting the liquid crystal display drive ■C1, the light beam emitted from the laser 75 having the fine light beam optical system 76 passes through the reflecting mirror 77 as shown by the straight arrow.
After being reflected by the polygon mirror 78, the light is reflected again by the polygon mirror 78, and is irradiated to one pixel 41 of the n pixels 41 of the liquid crystal display panel 4 via the lens 79. Then, as the polygon mirror 78 rotates, the path of the light beam changes continuously from the one shown by the solid arrow to the one shown by the chain line, and each pixel 41 in the group of pixels 41 is irradiated one by one.

Furthermore, the light beam that has passed through each pixel 41 is focused on a photocell 85 via a lens 86 and photoelectrically converted.

Thereby, the amount of transmitted light from each pixel 41 is detected.

Then, a data processing device (not shown) calculates the light transmittance for each pixel 41 of the pixel 41 group one by one in conjunction with, for example, the rotation of the polygon mirror 78.

In the above embodiments, a two-dimensional flat panel was used as the liquid crystal display panel 4, but if the load conditions permit, the liquid crystal display 7 panel may be a dedicated one-dimensional panel, in which liquid crystal pixels are arranged in a single row. Of course, panels arranged side by side may also be used.

Furthermore, in the above description of the embodiment, the X driver IC1
Although the test has been described above, it is clear that the test for the Y driver IC can also be performed in the same way, so a description of the test for the Y driver IC will be omitted.

〔Effect of the invention〕

According to the present invention, there is provided a contactor for probing an IC to be tested, a signal generator that can be controlled as appropriate to drive the IC to be tested via this contactor, and a liquid crystal display driven by an output signal of the IC to be tested. A panel, an illumination system that irradiates light to the driven pixels, a photoelectric conversion device that photoelectrically converts transmitted light from the pixels, and a light transmittance of each pixel in response to the output signal of the IC to be inspected by inputting the photoelectric conversion signal. Since it is equipped with a data processing device that determines the quality of the IC to be tested by calculating the
Inspecting image quality using a photoelectric conversion device and data processing device rather than human visual inspection improves the reliability of the inspection, and with the ability to perform the entire inspection automatically, the inspection speed becomes faster. By applying an actual load to the IC under test using a liquid crystal display panel and directly inspecting changes in image quality when it is installed in an actual liquid crystal display panel, a comprehensive and accurate test including subtle rise characteristics can be obtained. A characteristic test of the test tC can be performed.

[Brief explanation of the drawing]

FIG. 1 is an explanatory perspective view showing one embodiment of the inspection device for a drive IC for a liquid crystal display according to the present invention, and FIG. 2 is an explanatory plan view of the illumination system and charging conversion device portion showing another embodiment of the present invention. be. 1. LCD drive I which is the IC to be tested
C12... Contactor 3... Signal generator, 4... Liquid crystal display panel, 7.71... Illumination system, 8.81... Photoelectric conversion device, 9... Data processing 9 device, 12... IC to be tested Drive output line as an electrode of 13. Power source and signal source line as an electrode of the IC to be inspected; 41. Pixel. Invented on November 6, 1989 Inventor: Etsushi Suzuki

Claims (1)

[Claims] (1) A signal generation source including a contactor for probing the electrodes of the IC to be tested, and a power source for driving the IC to be tested via this contactor, which adjusts the level of the power source and the signal to appropriate levels. and a signal generator that can be switched at any time and can be freely combined according to inspection standards, and n (n is a natural number) of the above-mentioned IC to be tested.
a black-and-white liquid crystal display panel in which n pixels arranged in a straight line are driven by output signals; an illumination system that irradiates light to driven pixels among the pixels of this liquid crystal display panel; a photoelectric conversion device that photoelectrically converts transmitted light from the pixels irradiated by the system; and the liquid crystal display panel into which a photoelectric conversion signal for each pixel output from the photoelectric conversion device is input, and the output signal of the IC to be inspected corresponds to the output signal of the IC to be inspected. An inspection device for a drive IC for a liquid crystal display, comprising: a data processing device that determines the quality of the IC to be inspected by calculating the light transmittance of each pixel.