JP2002365660A - Liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily confirm output waveforms of an arbitrary source driver IC chip or an arbitrary gate driver IC chip. SOLUTION: Test electrode pads 11 which are connected to the test terminals of a source driver IC chip 4, are formed on a pixel electrode glass substrate 2. Each chip 4 has a function to select arbitrary terminals by an external test command so as to easily confirm the output waveforms of the output terminals and the cause of a failure is quickly and accurately found.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device used as a display device for video equipment such as a television monitor and a car navigation system, or for information equipment such as a computer.

[0002]

2. Description of the Related Art In recent years, in various applications such as audio / visual equipment, office equipment, in-vehicle equipment, and information communication equipment, the ratio of liquid crystal display devices is rapidly expanding. There is an increasing demand for thinner, lighter, and lower cost devices, and in order to meet this demand, a source driver IC for driving liquid crystal on a glass substrate on which active elements are formed.
CO that has been made more compact in the thickness direction by directly mounting the chip and the gate driver IC chip
A G (chip-on-glass) type liquid crystal display device is becoming popular.

The role of the source driver IC chip is as follows.
R, G, and B video signals are received, and signals for one horizontal line are output line-sequentially to each source line of the liquid crystal panel. The operation is described with reference to FIGS.
This will be briefly described with reference to the timing chart shown in FIG.

In FIG. 5A, OEH is a signal applied to an output enable terminal, and outputs a video signal sampled and held during a period of one horizontal cycle immediately before the rising edge. FIG. 5B shows a sample start input signal STH1, and FIG. 5C shows a sample start output signal STH2, which inputs and outputs as a video signal sampling start signal. , STH2, two sampling start input / output signal terminals, and when the signal displayed on the screen shifts from left to right, the STH1 terminal becomes the input terminal of the start pulse signal, and the STH2 terminal becomes the carry-out signal output terminal. Becomes When the shift direction is set to the opposite direction, the STH2 terminal becomes a start pulse signal input terminal, and the STH1 terminal becomes a carry-out signal output terminal. To simplify the following description of the operation, the shift direction is limited to the case from left to right.

[0005] CLK1 in FIG. 5D and CL in FIG.
K2 and CLK3 in FIG.
These three-phase pulses are shifted from each other, and are pulses for sampling the R signal, the G signal, and the B signal, respectively.
R, G, and B are R (red), G (green), and B (blue), respectively.
Signal. First, the start pulse signal STH1 is input, taken in in synchronization with the 0th rising edge of CLK1, and starts from the first rising edge of CLK1.
1 until the second rising edge of the analog signal R1
And the next output enable signal OEH
Is held until the rise of. Similarly, CL
At the rise of K2 and CLK3, the analog signals G1, B
1 is also sampled and held for a period until the next rise of the output enable signal OEH. Less than,
At the rising edges of CLK1, CLK2 and CLK3, the analog signals R2, G2, B2,... Are sequentially sampled and held for a period until the next rising edge of OEH. Then, at the 79th rising edge of CLK1, the carry-out signal STH2 is output.

When driving a large screen, the carry-out signal STH2 of the first stage of the source driver IC chip is connected to the start pulse signal input terminal of the next stage of the source driver IC chip, so that the liquid crystal drive output terminal can be easily operated. The number can be expanded. Thus, one horizontal line of RGB data is displayed on the screen.

Hereinafter, the configuration of a conventional liquid crystal display device will be described with reference to the drawings.

FIG. 3 is a structural view of a conventional liquid crystal display device, and FIG.
4 is an enlarged view of an output block A portion of the source driver IC chip shown in FIG. 3, 1 is a counter electrode glass substrate, 2 is a pixel electrode glass substrate, 3 is a gate driver IC chip,
4 is a source driver IC chip, 5 is a power supply and various control signal wirings, 6 is an output wiring of the gate driver IC chip 3 and the source driver IC chip 4, 7 is a flexible wiring board, 8 is a sample hold circuit, and 9 is an output buffer group. It is.

3 and 4, the pixel electrode glass substrate 2 is a substrate on the TFT array side, and a counter electrode glass substrate 1 is arranged opposite to the pixel electrode glass substrate 2. , 2 is filled with liquid crystal to form a display area. A non-display area is formed between the outer circumference of the display area and the outer circumference of the pixel electrode glass substrate 2, and the gate driver IC chip 3 and the source driver IC chip 4 are mounted on the non-display area. This gate driver I
The C chip 3 and the source driver IC chip 4 are also connected to electrodes in the display area via output wirings 6 of the gate driver IC chip and the source driver IC chip. The input side of the gate driver IC chip 3 is connected via a power supply and various control signal wirings 5, and the source driver IC chip 4
A flexible wiring board 7 is connected to an input side of the gate driver IC through an ACF (anisotropic conductive film) composed of conductive particles and an adhesive via a power supply and various control signal wirings 5. Chip 3, source driver IC
A signal for driving the chip 4 and a power supply voltage are supplied, and characters or images are displayed on the liquid crystal display cells to which the outputs of the gate driver IC chip 3 and the source driver IC chip 4 are connected.

In the liquid crystal display device having such a configuration,
As shown in FIG. 4, from the output block of the source driver IC chip 4, analog signals R, G, and B are output from the sample and hold circuit 8 as described with reference to FIG. Through source driver IC
It is sent to the output wiring 6 of the chip 4.

[0011]

However, as shown in FIG. 4, the output wiring 6 of the source driver IC chip 4 has a wiring width of 10 μm and a distance between the wirings of 20 μm. If the cause is caused by the source driver IC chip, even if the prober is set up directly on the output wiring 6 for analysis, the tip of the prober is wider, so that the A short circuit occurs and the output signal from the source driver IC chip 4 cannot be confirmed. In addition, even if an abnormal waveform can be confirmed without a rare occurrence of a short circuit, it is determined whether the failure is due to a contact failure when mounting the source driver IC chip or an output abnormality of the source driver IC chip itself. Can not do it.

Even if electrode pads for confirmation are arranged for each of the output wirings 6, a width of at least about 150 μm is required for erecting a prober, and the current distance between wirings cannot be increased. In addition, it is not possible to arrange an electrode pad for confirmation for each wiring. As a result, some problems occur in the liquid crystal panel, and the cause is caused by the source driver IC.
In the case of a chip, there is a problem that it is difficult to specify what number output is abnormal and what the cause is.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned conventional problem. In an output terminal group in an output block of a source driver IC chip or a gate driver IC chip, an output waveform from an arbitrarily selected output terminal is provided. To provide a liquid crystal display device capable of measuring the liquid crystal display.

[0014]

In order to achieve the above object, according to the first aspect of the present invention, there is provided a display area section comprising:
A liquid crystal driving source driver IC chip composed of at least two or more elements that scan in the horizontal direction and output data to the display area after sampling, and a liquid crystal driving gate that scans the display area in the vertical direction A driver IC chip, a non-display area in which power sources of the source driver IC chips and the gate driver IC chips, various control signal wirings, and output wirings of the source driver IC chips and the gate driver IC chips are arranged; And a flexible wiring board on which bus lines for supplying various control signals and power supply voltage to the source driver IC chip are provided.
An additional output terminal connected through switching means for selecting any one output from a large number of output terminals of the C chip;
A test electrode pad to which the additional output terminal is connected is provided, and it is possible to measure an output waveform arbitrarily selected in the output terminal group of the source driver IC chip.

According to a second aspect of the present invention, in the liquid crystal display device according to the first aspect, any one output from a group of output terminals of the source driver IC chip by a test command from the outside as a switching means. And an analog switch group for switching between a normal output and a test output, and an analog switch control circuit for performing an external command control.
In the output terminal group of the C chip, it is possible to measure an output waveform arbitrarily selected by switching an analog switch.

According to a third aspect of the present invention, there is provided a source driver for driving a liquid crystal, comprising: a display area; and at least two or more elements which scan in a horizontal direction, sample data, and output the data to the display area. An IC chip, a gate driver IC chip for driving a liquid crystal for scanning the display area in the vertical direction, a power supply for each of the source driver IC chip and the gate driver IC chip, various control signal wirings, a source driver IC chip and a gate What is claimed is: 1. A liquid crystal display device comprising: a non-display area in which an output wiring of a driver IC chip is arranged; and a flexible wiring board in which bus wiring for supplying various control signals and a power supply voltage to each driver IC chip is arranged. , The gate driver IC near the output terminal group in the gate driver IC chip.
An additional output terminal connected through switching means for selecting any one output from a large number of output terminals of the C chip;
A test electrode pad to which the additional output terminal is connected is provided, and it is possible to measure an arbitrarily selected output waveform in the output terminal group of the gate driver IC chip.

According to a fourth aspect of the present invention, in the liquid crystal display device according to the third aspect, any one output from a group of output terminals of the gate driver IC chip by a test command from the outside as a switching means. , And an analog switch group for switching between a normal output and a test output, and an analog switch control circuit for performing an external command control.
In the output terminal group of the C chip, it is possible to measure an output waveform arbitrarily selected by switching an analog switch.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a liquid crystal display device according to an embodiment of the present invention will be specifically described with reference to the drawings.

FIG. 1 is a configuration diagram of a liquid crystal display device according to an embodiment of the present invention. FIG. 2 is an enlarged view of an output block A portion of the source driver IC chip shown in FIG. Is a pixel electrode glass substrate, 3 is a gate driver IC chip, 4 is a source driver IC chip, 5 is a power supply and various control signal wirings, 6 is an output wiring of the gate driver IC chip and the source driver IC chip, 7 is a flexible wiring board, 8 is a sample and hold circuit, 9 is an output buffer group, 10 is an analog switch group, 11 is a test electrode pad, and 12 is an analog switch control circuit.

In FIG. 1 and FIG. 2, the pixel electrode glass substrate 2 is a substrate on the TFT array side, and the opposing electrode glass substrate 1 is disposed so as to face the pixel electrode glass substrate 2. , 2 is filled with liquid crystal to form a display area. A non-display area is formed between the outer circumference of the display area and the outer circumference of the pixel electrode glass substrate 2, and the gate driver IC chip 3 and the source driver IC chip 4 are mounted on the non-display area. The gate driver IC chip 3 and the source driver IC chip 4 are also connected to electrodes in the display area via the output wiring 6 of the gate driver IC chip 3 and the source driver IC chip 4.

The input side of the gate driver IC chip 3 is connected to a power supply and various control signal wirings 5, and the input side of the source driver IC chip 4 is connected to a power supply and various control signal wirings 5.
, The flexible wiring board 7 is connected by an ACF (anisotropic conductive film) composed of conductive particles and an adhesive, respectively, and drives the gate driver IC chip 3 and the source driver IC chip 4 from outside. A signal and a power supply voltage are supplied, and characters or images are displayed on the liquid crystal display cells to which the outputs of the gate driver IC chip 3 and the source driver IC chip 4 are connected.

In the liquid crystal display device of this embodiment, the output blocks of the source driver IC chip 4 output the analog signals R, G, and B from the sample and hold circuit 8 as described with reference to FIG. A control signal is sent from the analog switch control circuit 12 to an arbitrarily selected analog switch by an external test command through an output buffer group 9 and a test command from the outside. 2 is turned to the side in FIG. 2, and at the time of failure analysis, the output wiring 6 of the source driver IC chip 4 is turned to the analog switch group 10 to select a test terminal. And
At the time of failure analysis, an output waveform arbitrarily selected can be easily confirmed by setting a prober on the test electrode pad 11.

In this embodiment, the source driver IC
Although the output terminal group of the chip has been described as an object, the above configuration can be similarly applied to a gate driver IC chip.

Further, it is needless to say that the display area can be implemented in an active matrix type, a simple matrix type, or other types of panels. Although the shape of the formed test electrode pad is square, other shapes such as a round shape and a triangular shape may be used as long as the prober can be set up. It can be anywhere on the glass substrate.

[0025]

As described above, according to the present invention,
A liquid crystal display device in which an analog signal output from a liquid crystal driving IC chip can externally select an arbitrary output terminal and an output waveform can be confirmed using a test electrode pad is realized.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a liquid crystal display device according to an embodiment of the present invention.

FIG. 2 is an enlarged view of an output block A of the source driver IC chip shown in FIG. 1;

FIG. 3 is a configuration diagram of a conventional liquid crystal display device.

FIG. 4 is an enlarged view of an output block A of the source driver IC chip shown in FIG. 3;

FIG. 5 is a timing chart of a sampling start input / output signal and a clock, wherein (a) an output enable signal: OEH, (b) a sample start input signal: STH1, (c) a sample start output signal: STH2, and (d) a sampling clock. : CLK1 (e) Sampling clock: CLK2 (f) Sampling clock: CLK3 (g) Analog input signal (red): R (h) Analog input signal (green): G (i) Analog input signal (blue): B

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Counter electrode glass substrate 2 Pixel electrode glass substrate 3 Gate driver IC chip 4 Source driver IC chip 5 Power supply and various control signal wirings 6 Gate driver IC chip and source driver I
Output wiring of C chip 7 Flexible wiring board 8 Sample hold circuit 9 Output buffer group 10 Analog switch group 11 Test electrode pad

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) G09F 9/30 330 G09F 9/30 330Z 5G435 G09G 3/20 621 G09G 3/20 621M 670 670N 3/36 3 / 36 F term (reference) 2H088 FA12 HA08 MA20 2H092 JB77 MA57 MA58 5C006 BB16 BC11 BC20 BC24 BF24 EB01 5C080 AA10 BB05 DD28 FF11 JJ02 JJ04 5C094 AA43 BA43 CA19 DB03 EA03 EA04 EA07 EB03 EB04 EB04 EB04

Claims (4)

[Claims] 1. A source driver IC for driving a liquid crystal, comprising: a display area; and at least two pixels which scan in the horizontal direction, sample data, and output the data to the display area.
A chip, a gate driver IC chip for driving a liquid crystal for scanning the display area in the vertical direction, a power supply for each of the source driver IC chip and the gate driver IC chip, various control signal wirings, a source driver IC chip and a gate driver A liquid crystal display device comprising: a non-display area in which output wiring of an IC chip is arranged; and a flexible wiring board in which bus wiring for supplying various control signals and a power supply voltage to each of the driver IC chips is provided. An additional output terminal connected in the vicinity of an output terminal group of each of the source driver IC chips through a switching means for selecting an arbitrary output from a large number of output terminal groups of each of the source driver IC chips; And a test electrode pad connected to the liquid crystal display. 2. An analog switch group for selecting a normal output or a test output by selecting an arbitrary output from a group of output terminals of the source driver IC chip according to an external test command as the switching means and an external switch 2. The liquid crystal display device according to claim 1, further comprising an analog switch control circuit for performing the command control. 3. A source driver IC for driving a liquid crystal, comprising: a display area; and at least two or more elements that scan in the horizontal direction, sample data, and output the data to the display area.
A chip, a gate driver IC chip for driving a liquid crystal for scanning the display area in the vertical direction, a power supply for each of the source driver IC chip and the gate driver IC chip, various control signal wirings, a source driver IC chip and a gate driver A liquid crystal display device comprising: a non-display area in which output wiring of an IC chip is arranged; and a flexible wiring board in which bus wiring for supplying various control signals and a power supply voltage to each of the driver IC chips is provided. An additional output terminal is connected near an output terminal group of the gate driver IC chip through a switching means for selecting an arbitrary output from a large number of output terminals of the gate driver IC chip, and the additional output terminal is connected. A liquid crystal display device comprising: a test electrode pad to be tested. 4. An analog switch group for selecting a normal output or a test output by selecting any one output from a group of output terminals of the gate driver IC chip according to an external test command as the switching means, and an external switch. 4. The liquid crystal display device according to claim 3, further comprising an analog switch control circuit for performing the command control.