KR20000046767A - Checking device of liquid crystal display module - Google Patents

Abstract

PURPOSE: A checking device of a liquid crystal display module is provided to easily measure the product reliability by automatically carrying out the check of the test pattern displayed on a TFT-LCD module. CONSTITUTION: A transmitter(300) outputs video signals for displaying a test pattern on plural TFT-LCD modules. Plural receivers(200) receives video signals outputted from the transmitter(300) and transmits the received video signals to each TFT-LCD module. An interface unit(400) transmits the signals of the receivers(200) to corresponding TFT-LCD modules. A computer measures the current and voltage when driving the plural TFT-LCD modules, judges the defects of the TFT-LCD modules, and controls the operations of the system.

Description

Inspection device of liquid crystal display module

The present invention relates to an inspection apparatus for a liquid crystal display module (hereinafter referred to as TFT-LCD) composed of a thin film transistor, and more particularly, to an inspection apparatus for a liquid crystal display module capable of performing a life test simultaneously with the performance inspection of a TFT-LCD. will be.

In general, as a final step in the production line of the TFT-LCD module, the quality of the product is inspected to prevent defective products from being sold to consumers. In particular, a process of checking a display quality by driving a specific test pattern, a process of inspecting a defect such as an overload or a short, and a process of checking the life of a product are absolutely necessary to improve the reliability of the product.

At this time, the inspection of the TFT-LCD module is made in a constant temperature and humidity chamber, and the inspection one by one takes a lot of work time, which causes a problem of lowering productivity. Therefore, equipment for enabling the inspection of multiple TFT-LCD modules at the same time is provided.

1 is a block diagram showing the configuration of a TFT-LCD module inspection system according to the prior art.

Referring to Fig. 1, twelve tests are carried out on a jig 2 in which twelve TFT-LCD modules 1 are fixedly mounted at the same time, and on each of the TFT-LCD modules 1 under the control of a PC operated by a user. VGA card 3 for outputting a drive signal for displaying a pattern, pattern display means 4 for monitoring a test pattern while a test pattern is displayed in the TFT-LCD module 1, and the VGA card 3 Transmitter 5 for converting the digital image signal for the test pattern output from the TTL (Transistor-Transistor Logic) level signal to the signal of the ECL (Emitter Coupled Logic) level, and output from the VGA card (3) Distribution unit 6 for distributing the signals converted by the transmission unit 5 into 12 signals for input to the 12 TFT-LCD modules 1, and 28 digital signals transmitted from the distribution unit 6; Receive image signals and input them to each TFT-LCD module 1 A receiving unit 7 for displaying the same test pattern on all the TFT-LCD modules 1, an interface unit 8 connecting the distribution unit 6 and the receiving unit 7, and the 12 TFT-LCD modules And a power supply 11 for supplying driving power to each part of the system as a whole.

At this time, the transmitter 5, the distribution unit 6 and the receiver 7 is made of a TTL IC or CMOS IC, the jig 2 and the receiver 7 is a constant temperature and humidity chamber 12 for the accuracy of operation ), The VGA card 3, the pattern display means 4, the transmission section 5, the distribution section 6, the current display window 9, the voltage display window 10 and the power supply 11 are control racks. (control rack) (13).

The operation of the prior art having the above configuration will be described with reference to the flowchart of FIG. 2.

First, the twelve TFT-LCD modules 1 are mounted on the jig 2 to be connected to the receiver 7 (S1), and the power supply 11 of the control rack 13 is turned on to drive necessary for operation of the system. Power is applied (S2), and a PC (not shown) is operated to execute software for displaying a test pattern on each TFT-LCD module 1 (S3).

According to the execution of the software, in the VGA card 3, digital image signals for 28 test patterns are generated in the TFT-LCD module 1 (S4). In this case, the digital video signal includes RGB horizontal and vertical synchronization signals.

Thereafter, the digital video signal is inputted to the transmitter 5, in which the TTL level signal is converted into an ECL level signal (S5). The converted ECL level signals are distributed (S6) into twelve signals in the distribution section 5 so as to be input to the twelve TFT-LCD modules 1, respectively. That is, 28 test pattern signals are distributed to 12 each.

The divided signal is inputted to the TFT-LCD module 1 via the interface unit 12 and the receiving unit 8 (S7) and displayed in a test pattern (S8). In this case, all the TFT-LCD modules 1 ), The same test pattern is displayed, and 28 test patterns are sequentially displayed.

While the test pattern is displayed, the total current and voltage flowing through the twelve TFT-LCD modules 1 are displayed on the current display window 9 and the voltage display window 10. At this time, the user checks the defects of the twelve TFT-LCD modules 1 by the values of the current and the voltage of the current display window 9 and the voltage display window 10 (S9). That is, it is determined whether the displayed current and voltage are within a predetermined range.

At this time, it is determined whether a failure occurs (S10), and if a failure occurs, all 12 TFT-LCD modules 1 are treated as a failure (S11). At this time, the twelve TFT-LCD modules 1 are separately retested to determine which TFT-LCD module has a failure. If the failure does not occur in the above, the user performs a test for a life of 2000 hours (S12).

The prior art as described above is performed by visual inspection to check the test pattern displayed on the TFT-LCD module 1 by the operator entering the constant temperature and humidity chamber 12, so that the reliability of the product cannot be determined systematically. There is a problem that it is difficult to do, because the current consumption and voltage display of each TFT-LCD module 1 is not made, there is a problem that it is difficult to determine the state of each module.

In addition, the thermo-hygrostat 12 and the control rack 13 are usually two to three meters apart, but the transmission part 5, the distribution part 6 and the receiving part 7 are made of a TTL IC or a CMOS IC. There is a problem that time delay and noise occur during transmission and remote transmission.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and its object is to provide a plurality of receivers and interface units to correspond to a plurality of TFT-LCD modules so that the distribution and transmission of digital video signals are made separately. An object of the present invention is to provide an inspection apparatus for a liquid crystal display module capable of increasing reliability in evaluating quality.

In addition, another object of the present invention is to configure the transmitter, the distribution unit and the receiver using an ECL (Emitter Coupled Logic) IC to prevent signal delay and noise inflow due to high frequency transmission to facilitate the detection of product defects The present invention provides an inspection apparatus for a liquid crystal display module.

1 is a view showing the configuration of an inspection system of a liquid crystal display module according to the prior art;

2 is a flowchart showing an inspection operation according to the prior art;

3 is a view showing the configuration of an inspection system for a liquid crystal display module according to the present invention;

4 is a flowchart showing an inspection operation according to the present invention;

A main feature of the present invention for achieving the above object is a transmitter for separately outputting a video signal for displaying a test pattern on a plurality of TFT-LCD modules, and receiving the video signals output from the transmitter, respectively A plurality of receivers for individually inputting to a TFT-LCD module, an interface unit for transmitting signals of the respective receivers to respective TFT-LCD modules corresponding thereto, and individually when driving the plurality of TFT-LCD modules A computer that determines the failure of each TFT-LCD module by measuring current and voltage and controls the operation of the system, and a warning that informs the user according to the control signal of the computer when a failure occurs in a plurality of TFT-LCD modules. It includes a display unit.

As an additional feature of the present invention for achieving the above object, the transmitter is a pattern generating means for outputting a video signal for a plurality of test patterns, and the image signal output from the pattern generating means TTL (Transistor-Transistor Logic) Level conversion means for converting the ECL (Emitter Coupled Logic) level to the ECL level, and distribution means for distributing the signals converted by the level conversion means into a plurality of signals for input to the plurality of TFT-LCD modules.

Another additional feature of the present invention for achieving the above object is that the level converting means, distribution means and the receiving unit is configured using an ECL (Emitter Coupled Logic) IC.

Another additional feature of the present invention for achieving the above object is a shielded twisted pair cable (shielded & twisted pair cable) so that the connection between the transmitter and the receiver can block the signal attenuation by the distance and the inflow of noise It is done using.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

3 is a view showing the configuration of an inspection system of a liquid crystal display module according to the present invention, and is composed of a measurement unit 200, an inspection unit 300, and an interface unit 400.

The inspection unit 300 uses a computer, inside the computer, a VGA card 310 for generating a digital video signal of the LCD module and a digital input / output board 330 for remote control of the LCD module in the constant temperature and humidity chamber, module failure When it occurs is made of AD board 320 to obtain the values displayed in the module power control and measurement unit.

In addition, a warning light is also provided at the top of the shelf so that the user can easily detect a defect by sending a signal through the digital input / output board 330 by inspecting the values of the AD board 320 in the software of the computer.

In addition, the measurement unit 200 performs a function of power control and measurement for each module in a 1: 1 manner for each of the 12 LCD modules. The measurement unit 200 displays current and voltage values for each module, and the user can limit the limits thereof. By setting, if the value is larger than the setting value, the warning light and the buzzer are provided to emit light and warning sound, and the corresponding message is displayed on the computer.

In addition, the total time control of the test pattern, the timer function of the specific pattern, and the remote control function can be controlled from the software. In addition, by using ECL (Emitter Coupled Logic) IC to cope with high frequency, stable distribution of signal is possible, and shielded & twisted pair cable is used to block attenuation of signal and distance of noise by distance.

Referring to Figure 4 attached to the preferred operation example of the inspection apparatus of the liquid crystal display module according to the present invention configured as described above are as follows.

4 is a view illustrating an operation process of the inspection apparatus of the liquid crystal display module according to the present invention.

First, in step S101, the operation preparation is made before placing the TFT-LCD module on the jig. Looking at the operation preparation process, first of all, check that all the power supplies are off and that each connector of the system is properly connected.

Subsequently, the process proceeds to step S102, all the switches of the interface unit (the I / F unit inside the constant temperature and humidity chamber of FIG. 3B) are turned off, and then the LCD module is mounted on the jig, and in step S103, the main power supply is turned on. In addition, the module switch, the distribution switch, and the reception switch attached to the control shelf are all turned on by the process of step S104.

Through the process of step S104 described above, turn on the power supply for each module to which each LCD module is connected and the power of the measurement unit, and turn on the backlight power switch, logic power switch, and signal power switch of the interface unit in order, and then for each module. After adjusting the voltage and current limits in the power supply control and measurement unit, select the logic and signal voltages of the 12 LCD modules to be driven, and after the power is turned on, proceed to step S105 to determine the measured value, that is, the voltage and current. Check if there is any.

If the overcurrent and overvoltage are displayed in step S105, the LCD module is replaced or the connector is re-checked. If the execution of the hardware is completed through the above-described process, the process proceeds to step S106 to start the software on the PC. The user inputs the sequence and time of the test pattern and the total driving time to drive the test pattern.

Then, the VGA card generates 28 digital video signals (R, G, B, horizontal synchronization, vertical synchronization) through the process of step S107, converts the TTL level, which is the VGA card output, into the ECL level, and transmits it to the distribution unit.

The distribution unit distributes the received signals into 12 signals to distribute 28 digital signals input through the process of step S108 to 12 LCD modules to be driven. The reason for the conversion to the ECL level is that the distance between the control shelf and the constant temperature / humidity chamber is 2 to 3m away, resulting in phase delay and noise depending on the distance.

Therefore, the system uses ECL ICs to cope with high frequency signals, enabling safe distribution of signals, and shielded & twisted pair cables to block signal attenuation and distance from noise.

In addition, ECL ICs provide logic such as TTL and CMOS types, but have very fast switching times, making it easy to handle high-speed digital signals, and when the signals such as clocks are transmitted over long distances, they are out of phase with each other. It is easy to transmit differential signals at the same time. It carries switching limit information from the source to the load, making it insensitive to losses in the transmission line and changes in the power supply.

Thereafter, there are 28 signals required for driving the LCD module in each of the 12 identical signals distributed through the process of step S108, and each of these signals is transmitted from the receiving unit to the LCD through the process of steps S109 and S110. The test pattern is driven to the module.

At this time, if the user detects higher or lower than the voltage and current set by the power control and measurement unit for each module in the driving LCD module, that is, it is determined that an error has occurred in the normal operation checking step of Step S111, the AD in the inspection unit 300. The buzzer, such as a warning light, sounds through the digital input / output board 330 by obtaining data from the board 320.

After that, the on / off time of the backlight / logic / signal voltage set by software is automatically performed through the digital input / output board in the PC.

By providing an inspection apparatus of the liquid crystal display module according to the present invention operating as described above, the operator automatically enters the constant temperature and humidity chamber and checks the inspection method made by visual inspection to check the test pattern displayed on the TFT-LCD module. The performance has the effect of providing ease for measuring the reliability of the product.

In addition, since the current consumption and voltage of each TFT-LCD module 1 can be displayed, it is easy to grasp the state of each module.

Claims (4)

A transmitter for separately outputting video signals for displaying a test pattern on a plurality of TFT-LCD modules, a plurality of receivers for receiving the video signals output from the transmitter and inputting them individually to each TFT-LCD module; Determining the failure of each TFT-LCD module by measuring the current and voltage separately when the interface unit for transmitting the signal of each receiving unit to each TFT-LCD module corresponding to each of the plurality of TFT-LCD modules And a computer for controlling the operation of the system, and a warning display unit for informing a user according to a control signal of the computer when a failure occurs in a plurality of TFT-LCD modules. The method of claim 1, The transmitter generates a pattern generating means for outputting video signals for a plurality of test patterns, and a level conversion for converting the video signal output from the pattern generating means from a TTL (Transistor-Transistor Logic) level to an ECL (Emitter Coupled Logic) level. Means and distribution means for distributing the signals converted by the level converting means into a plurality of signals for input to the plurality of TFT-LCD modules. The method of claim 1, And said level converting means, distributing means and receiving portion are configured by using an ECL (Emitter Coupled Logic) IC. The method of claim 1, The transmitter and the receiver are connected to each other using a shielded twisted pair cable to shield a signal from a distance and influx of noise.