JP2005043205A - Lighting aging test system for flat-panel display - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lighting aging test system for a flat-panel display. <P>SOLUTION: This lighting aging test system electrically connected to a plurality of flat-panel displays has a constitution including a signal generator 11 for generating a power signal and the first control signal, one or more signal adjusting circuits 12 electrically connected to the signal generator 11 in order to adjust the first control signal to the second control signal corresponding to a test condition, and one or more booster circuits 13 electrically connected to the signal adjusting circuits 12 in order to improve the signal level and the driving performance of the power signal and the second control signal. The plurality of flat-panel displays 14 are driven by the boosted power signal, and the lighting aging test of the plurality of flat-panel displays 14 is performed by the second control signal. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a lighting aging test system for flat panel displays.

  With the trend of mass production and consumption, the market demands for the quality of electrical products are becoming more and more stringent. So, for example, designers and manufacturers of liquid crystal displays (LCDs) are not only paying much attention to product design recently, but must also take new steps to improve production efficiency and manufacturing yield. It must be gone. For flat panel display manufacturers, particularly liquid crystal display (LCD) manufacturers, product life is an important issue, and manufacturers are constantly striving to extend their life.

  With the adoption of burn-in testing, LCD manufacturers can now guarantee product quality. Therefore, it can be said that the burn-in test is effective in enhancing the reliability of the product and provides a reliable means. Products that pass the burn-in test are guaranteed high reliability and long life. Of particular importance is that factory-delivered products that pass the burn-in test can guarantee a low defect rate.

  The liquid crystal panel will fail after an unspecified period during use. Therefore, a lighting aging test apparatus has been proposed as a means for improving such drawbacks. In order to accelerate the aging of the defective LCD during the burn-in test and selectively remove the defective products during the test, the lighting aging test is indispensable. In particular, it is a bastion that ensures the reliability of products, so that manufacturers can provide guarantees they are satisfied with to clients and end users. From such a point of view, the results of the aging test are considered to be the most effective data for obtaining a reliable means for improving the manufacturing process.

  With significant advancement in technology, small-sized low-temperature polysilicon thin film transistor liquid crystal modules (LTPS TFT-LCMs) have become indispensable components for everyday appliances. For example, LTPS TFT-LCM is applied to information appliances (IA) such as digital still cameras and mobile phones. According to the lighting aging test, the test of the aging state of the LTPS TFT-LCM in various operating environments and operating conditions is possible under various environmental conditions. Further, according to the lighting aging test, the aging of the LTPS TFT-LCM is promoted and the aging period is shortened, so that the aging test can be performed during the manufacturing test. The data obtained by the aging test is also used for statistical analysis in order to study the aging process of LTPS TFT-LCM.

  Recently, conventional aging systems for flat panel displays have been applied to testing field programmable gate arrays (FPGAs) mounted on printed circuit boards. In that case, the printed circuit board is set in an environmental test container, and the flat panel display is electrically connected, thereby sending a signal necessary for driving the flat panel display and applying a voltage to the flat panel display. The lighting aging test is performed.

  Up to now, among various system architectures related to information home appliances developed by manufacturers, the problem related to non-uniformity remains unresolved and has not yet been standardized. Standards for signal sources used in flat panel displays are derived from a variety of perspectives, making them suitable for medium or large LCD panels. Thus, until now, no appropriate standard has been set for the signal source used in LTPS TFT-LCM.

  Therefore, LTPS TFT-LCM manufacturers must design dedicated FPGA devices that are compatible with the signal source and drive voltage used in LTPS TFT-LCM. Further, since the driving capability of a signal source that conforms to one existing FPGA is limited, it is only possible to drive a single flat panel display rather than driving a plurality of flat panel displays. In addition, the price of FPGA is high.

  Due to the drawbacks mentioned above, the lighting aging test system is expensive and the test equipment has insufficient driving capability, so it is impossible to further improve the test efficiency and manufacturing yield of flat panel displays. It is.

  The main object of the present invention is to provide a lighting aging test system for a flat panel display in which the flat panel display is driven by an output signal of one field programmable gate array (FPGA) device.

  It is another object of the present invention to provide a lighting aging test system for a flat panel display having an increased driving performance by one field programmable gate array (FPGA) device and a plurality of signal conditioning circuits. Yes. The plurality of signal conditioning circuits meet the demand for driving more flat panel displays with high yield and low cost.

  The lighting aging test system according to the present invention is electrically connected to a plurality of flat panel displays that perform a lighting aging test. The lighting aging test system according to the present invention includes a signal generator for generating a power signal and a first control signal, and the first control signal is adjusted to the second control signal according to a test condition. At least one signal conditioning circuit electrically connected to a signal generator and electrically connected to the signal conditioning circuit to increase signal levels of the power signal and the second control signal to improve driving performance; A plurality of flat panel displays driven by the boosted power signal, and a lighting aging test of the plurality of flat panel displays by the second control signal. Is to do.

  In the lighting aging test system, the signal generator is preferably a field programmable gate array (FPGA) device for generating the power signal and the first control signal.

  Moreover, it is preferable that said lighting aging test system is installed in an environmental test container.

  In the lighting aging test system, it is preferable that the signal generator further generates a first reference signal necessary for an internal circuit of the flat panel display.

  Furthermore, it is preferable that the signal generator includes an operational amplifier circuit that adjusts the level of the first reference signal in order to output the second reference signal.

  The signal generator further includes a current amplification circuit that adjusts a current gain of the first control signal so as to increase a maximum allowable number of flat panel displays that can be driven by the lighting aging test system. It is preferable to provide.

  The booster circuit is preferably a DC / DC converter.

  The flat panel display is preferably a low temperature polysilicon thin film transistor liquid crystal module.

  The lighting aging test system preferably includes 10 sets of signal adjustment circuits and one booster circuit.

  Each of the signal adjustment circuit and the booster circuit is preferably capable of driving at least six flat panel displays.

  The features and advantages of the lighting aging test system according to the present invention will become more apparent from the following description with reference to the related drawings.

  FIG. 1 is a block diagram showing a circuit configuration of a lighting aging test system for a flat panel display according to the present invention. The lighting aging test system according to the preferred embodiment shown in FIG. 1 has sufficient capability to drive 60 flat panel displays, and illustrates the configuration and principle of the system according to the present invention. It is used as one means. However, it should be understood that the lighting aging test system according to the embodiment does not limit the technical scope included in the present invention. On the other hand, if it is an expert with ordinary knowledge in the technical field according to the present invention, based on the technical idea disclosed here, lighting for flat panel displays corresponding to their needs It is possible to design an aging test system. Further, the number of the lighting aging test system that drives the flat panel display can be arbitrarily changed.

  As shown in FIG. 1, a lighting aging test system 10 for a flat panel display according to the present invention is electrically connected to 60 flat panel displays 14, whereby a lighting aging test of the flat panel display 14 is performed. Is done. The lighting aging test system 10 according to the present invention includes one signal generator 11, at least one signal adjustment circuit 12, and at least one booster circuit 13. The lighting aging test system 10 and the flat panel display 14 are disposed in an environmental test container (not shown).

In the case of this preferred embodiment, the signal generator 11 may be constituted by an FPGA device designed by a chip designer to meet predetermined test conditions. The FPGA device includes a power signal Sp, a first control signal Sc1, and a first reference signal (Vcom). in) can be generated. Further, each of the signal adjustment circuits 12 is connected to the signal generator 11, and each signal adjustment circuit 12 mainly includes an operational amplifier circuit and a current amplifier circuit.

Both the operational amplifier circuit and the current amplifier circuit can be actually designed by circuit design methods well known in the art. FIG. 2 is a circuit diagram showing an operational amplifier circuit in the signal conditioning circuit shown in FIG. As shown in FIG. 2, the operational amplifier circuit 20 includes a first reference signal (Vcom) supplied from the signal generator 11. in) is adjusted by the variable resistors R1 and R3, the fixed resistor R2 and the operational amplifier 21 according to different test conditions, and the second reference signal (Vcom) for output to the flat panel display 14 is adjusted. out).

  Furthermore, the above-described current amplification circuit (not shown) can be configured by a plurality of transistors that increase the current gain of the first control signal Sc1 supplied from the signal generator 11 and generate the second control signal Sc2. . With such a configuration, the lighting aging test system 10 can drive more flat panel displays. Since the circuit design of the current amplifier circuit is well known in this technical field, a detailed description is omitted here.

  As shown in FIG. 1, the plurality of booster circuits 13 are electrically connected to one of the corresponding signal adjustment circuits 12. Each booster circuit 13 is electrically connected to a plurality of flat panel displays 14 in order to perform a lighting aging test. One preferred arrangement is to drive six flat panel displays 14 simultaneously by combining each booster circuit 13 and corresponding signal conditioning circuit 12. Each booster circuit 13 is a DC / DC converter that is used to increase the signal level and drive performance of the power signal Sp and the second control signal Sc2 supplied from the signal adjustment circuit 12. Note that the increase in signal level is, for example, from 3.3 V to 12 V required for the flat panel display 14. The boosted power signal is output to drive the flat panel display 14, and the second control signal Sc2 is input to the flat panel display 14 to complete the lighting aging test.

  As is apparent from the above description, the lighting aging test system 10 according to the present invention basically uses a signal source supplied from a field programmable gate array (FPGA). For example, in order to improve the drive performance, the signal adjustment circuit 12 includes 10 sets of signal adjustment circuits 12 and one booster circuit 13 that adjust and raise a signal supplied from the FPGA.

  Accordingly, each of the signal adjustment circuit 12 and the booster circuit 13 can drive six flat panel displays, and the lighting aging test system 10 according to the present invention drives a total of 60 flat panel displays 14. Can be made. Of course, the flat panel display 14 to which the lighting aging test system 10 according to the present invention is applied is mainly LTPS TFT-LCM.

  In conclusion, the lighting aging test system 10 according to the present invention substantially includes a signal source and generates a voltage necessary for the lighting aging test of the flat panel display 14. Further, the maximum allowable number of flat panel displays 14 that can simultaneously perform the lighting aging test can be increased depending on the signal level and the driving performance. The lighting aging test system 10 according to the present invention only needs to use one FPGA device to perform the lighting aging test of the plurality of flat panel displays 14 at a low manufacturing cost and a high yield.

  The above description discloses an example that is presently the most practical and considered a preferred embodiment. However, it should be understood that the present invention is not limited to the above-described embodiments. On the contrary, the invention is intended to cover various modifications and similar arrangements, and the appended claims correspond to a broad description so as to encompass all such modifications and similar arrangements. The technical idea of the invention described in the scope of the invention and its scope are included. Therefore, the above disclosure and description should not be taken as limiting the scope of the invention which is defined by the appended claims.

It is a block diagram which shows the circuit structure of the lighting aging test system for flat panel displays which concerns on this invention. FIG. 2 is a circuit diagram showing an operational amplifier circuit in the signal conditioning circuit shown in FIG. 1.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Lighting aging test system 11 Signal generator 12 Signal adjustment circuit 13 Booster circuit 14 Flat panel display

Claims (5)

A lighting aging test system electrically connected to a plurality of flat panel displays in order to perform a lighting aging test of a plurality of flat panel displays,
A signal generator for generating a power signal and a first control signal;
At least one signal conditioning circuit electrically connected to the signal generator to adjust a first control signal to a second control signal, depending on test conditions;
In order to increase the signal level of the power signal and the second control signal and improve the driving performance, it includes at least one booster circuit electrically connected to the signal adjustment circuit,
The lighting aging test system further comprises driving the plurality of flat panel displays with the boosted power signal and performing a lighting aging test on the plurality of flat panel displays with the second control signal.   The lighting aging test system of claim 1, wherein the signal generator is a field programmable gate array (FPGA) device.   The lighting aging test system according to claim 1, wherein the signal generator further generates a first reference signal that is a reference signal for an internal circuit of the plurality of flat panel displays.   The lighting aging test system according to claim 3, wherein the signal adjustment circuit includes an operational amplifier circuit that adjusts the first control signal to the second control signal. The signal adjustment circuit further includes a current amplification circuit that adjusts the current gain of the first control signal so that the number of flat panel displays that can be driven by the lighting aging test system can be increased. The lighting aging test system according to claim 1.

Images