JPH11183861A - LCD panel inspection equipment - Google Patents

Abstract

(57) [Problem] To provide an inspection apparatus for a liquid crystal panel which can efficiently perform an inspection including an operation margin of a liquid crystal panel and can be developed independently of a circuit board. SOLUTION: A driving signal generating device 11 outputs a driving signal to a liquid crystal driver IC 12 to output a liquid crystal driver I.
C12 is directly controlled and the LCD driver IC12
Turns on and displays the liquid crystal panel 14, and the CCD camera unit 16 includes the drive signal generator 11, the liquid crystal driver IC
A panel lighting circuit composed of 12 and an inspection probe 13 and a liquid crystal panel 14 lit and displayed by a backlight 15
Of the liquid crystal panel 14 read by the CCD camera unit 16 to detect a defect.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal panel inspection apparatus for performing a display inspection of a transmission type or reflection type liquid crystal panel, and more particularly to an inspection including an operation margin of the liquid crystal panel and independent of a circuit board. The present invention relates to a liquid crystal panel inspection device that can be developed.

[0002]

2. Description of the Related Art Conventionally, when manufacturing a liquid crystal panel, there is a case where adjacent wiring patterns are electrically connected to each other in an etching process or the like, so that a defect inspection is often performed on the liquid crystal panel. When an IC for a liquid crystal driver (hereinafter referred to as “liquid crystal driver IC”) is not mounted on the liquid crystal panel, the liquid crystal driver I
Either use a drive test for directly inputting an external signal to the liquid crystal panel without using C and perform a display test of the panel, or use an actual drive test for driving a liquid crystal driver IC and perform a display test of the panel. Will be inspected.

In this actual driving test, as shown in FIG.
An input signal generator 51 generates an input signal required for actual driving and lighting of the liquid crystal panel 58, a drive signal controller 52 controls the timing of the input signal and generates a drive signal for a liquid crystal driver IC 53, and the liquid crystal driver IC 53 The panel 58 is lit and displayed, and the inspection probe 57 contacts the terminal of the liquid crystal panel 58 with the output of the liquid crystal driver IC 53. Then, the backlight 59 is turned on to display a screen on the liquid crystal panel 58. The CCD camera unit is operated by the CCD camera controller 54 to control the liquid crystal panel 58.
Is imaged and read, and a signal on the display screen imaged by the defect detection device 55 is subjected to image processing to detect a defect, or is visually inspected by a person. Here, for example, the driving circuit of the TFT liquid crystal panel has the same configuration as the driving circuit of the mounted liquid crystal panel module unit, and the timing control of the input signal generator 51 and the liquid crystal driver IC 53
A drive signal control circuit board that is incorporated in a drive circuit of a liquid crystal panel module unit, which is a mounted product, is used as it is for the drive signal control device 52 that generates the drive signal.

[0004]

However, if the mounted drive signal control circuit board is used as it is as the drive signal control device, the signal level and the timing of the control signal are fixed, so the liquid crystal panel However, there arises a problem that the inspection including the operation margin cannot be performed. Therefore, even if the liquid crystal panel is determined to be non-defective by the inspection of the liquid crystal panel, there is a possibility that the liquid crystal panel will be defective at the final inspection stage as the liquid crystal panel module.

Further, since the shape and configuration of the drive signal control circuit board vary depending on the size of the liquid crystal panel and user specifications, the drive signal control circuit board may be changed for each model of liquid crystal panel.

Further, when the development of a drive signal control circuit board is accompanied by the new development of a liquid crystal panel, the drive signal control circuit board is incorporated into an inspection device, and after the shape and configuration of the liquid crystal panel are determined, the integrated portion of the circuit board is determined. Therefore, it is necessary to develop an inspection head, which delays the development period of the inspection apparatus.

[0007] Therefore, in the actual driving test of a liquid crystal panel, it is necessary to efficiently perform a test including an operation margin of the liquid crystal panel and to realize a liquid crystal panel test apparatus which can be developed independently of a circuit board. It is an important issue.

It is an object of the present invention to solve the above-mentioned problems and to provide an inspection apparatus for a liquid crystal panel which can efficiently perform an inspection including an operation margin of a liquid crystal panel and can be developed independently of a circuit board. .

[0009]

In order to achieve the above object,
According to a first aspect of the present invention, there is provided an inspection of a liquid crystal panel having at least a liquid crystal panel and a liquid crystal driver IC for lighting and displaying the liquid crystal panel, and supplying a driving signal to the liquid crystal driver IC to inspect a display state of the liquid crystal panel. The device is characterized in that it comprises a drive signal generating means for supplying a power and a control signal to the liquid crystal driver IC and directly controlling the liquid crystal driver IC.

According to a second aspect of the present invention, the drive signal generating means variably controls a power source for driving the liquid crystal driver IC and a level and timing of a control signal in order to inspect an operation margin of the liquid crystal panel. Features.

In a third aspect, the liquid crystal panel includes:
A panel in which a thin film transistor is formed for lighting display, wherein a writing time for turning on the thin film transistor and a holding time for holding writing data are variably controlled to inspect a defect and a characteristic defect of the liquid crystal panel. Features.

[0012]

Embodiments according to the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a schematic configuration of a liquid crystal panel inspection apparatus used in the present embodiment. As shown in FIG. 1, the liquid crystal panel inspection device includes a driving signal generator 11 and a liquid crystal driver IC.
It comprises an inspection probe 13, a liquid crystal panel 14, a backlight 15, a CCD camera unit 16, a defect detection device 17, and a CCD camera control device 18.

The driving signal generator 11 outputs a driving signal to the liquid crystal driver IC 12 to output the driving signal to the liquid crystal driver IC 12.
It is a device that directly controls C12 and plays a role of an input signal generator and a drive signal controller in the conventional configuration shown in FIG. The drive signal generator 11
Will be described later in detail.

The liquid crystal driver IC 12 is connected to the liquid crystal panel 1.
The inspection probe 13 is an IC for lighting and displaying No. 4.
The output of the liquid crystal driver IC is brought into contact with the terminal of the liquid crystal panel 14. The CCD camera unit 16 is an optical unit for imaging and reading a display screen of the liquid crystal panel 14 illuminated and displayed by the backlight 15 and a panel lighting circuit including the drive signal generator 11, the liquid crystal driver IC 12, the inspection probe 13, and the like. is there. The CCD camera control unit 18 is a control unit that controls the CCD camera unit 16, and the defect detection unit 17 is a processing unit that performs image processing on the display screen of the liquid crystal panel 14 read by the CCD camera unit 16 to detect defects. As described above, the liquid crystal panel inspection apparatus used in the present embodiment is different from the conventional apparatus shown in FIG. 4 in that the input signal generator and the drive signal controller are eliminated, and the drive signal generator for directly controlling the liquid crystal driver IC 12 is provided. The configuration is such that the device 11 is provided.

Next, the drive signal generator 11 shown in FIG. 1 will be specifically described. Here, a case where a TFT liquid crystal driver IC is used is shown. FIG.
FIG. 3 is a diagram illustrating a configuration of a drive circuit of a TFT liquid crystal panel module unit. As shown in the figure, two types of liquid crystal driver ICs, a gate line liquid crystal driver 22 and a data line liquid crystal driver 23, are required to light the TFT liquid crystal panel 21. Therefore, the drive signal generator 11 can light the TFT liquid crystal panel 21 by supplying a power supply and a control signal necessary for driving the liquid crystal driver 22 for the gate line and the liquid crystal driver 23 for the data line. .

The signals input to the gate lines and data lines of the TFT liquid crystal panel 21 are determined by power and control signals supplied to the gate line liquid crystal driver 22 and the data line liquid crystal driver 23. For this reason, the drive signal generator 11 changes the level and timing of the signals supplied thereto to change the lighting signal fixed in the conventional actual drive test.

As described above, the drive signal generator 11
By supplying a power supply and a control signal for driving the liquid crystal driver IC using, and performing appropriate level setting and timing setting, the operation margin of the TFT liquid crystal panel 21 can be inspected.

Next, the inspection of the operation margin of the TFT liquid crystal panel 21 will be described. The display driving of a cathode ray tube television is a dot sequential driving method in which a screen is scanned from upper left to lower right in accordance with a scanning line running from top to bottom of the screen to form a screen of one frame or one field. A driving method called line-sequential driving is used as the driving method 21. That is, in a CRT television, 1
Since the scanning line time is about 60 μs, if the number of pixels in the horizontal direction is 600, the scanning time per pixel is 100n.
However, in the case of the TFT liquid crystal panel 21, since it is not possible to follow up under such conditions, line sequential driving in which data writing to pixels by the data line liquid crystal driver 23 is simultaneously sent for each scanning line (one gate line) is performed. Adopted.

In the line-sequential driving of the TFT liquid crystal panel 21, the time for writing data to the picture element of the TFT liquid crystal panel 21 for each gate line, that is, the ON time of the TFT is about 25 μs in the case of SVGA. In the case of XGA, the time is about 20 μs, and therefore, in the conventional actual driving inspection device, the inspection is performed with this writing time fixed.
However, as a specification of the mounted liquid crystal panel module, there is a case where the writing time is specified with a width above and below the fixed value and the writing time is changed on the user side. Therefore, the drive signal generator 11 performs level setting and timing setting so as to allow the width of the writing time indicated by the specification of the liquid crystal panel module, and inspects the operation margin of the TFT liquid crystal panel 21.

In the TFT liquid crystal panel 21, once written data must be held until data is written again after scanning one entire screen. This data retention time is also specified in the specification, similarly to the write time. For this reason, the drive signal generator 11 sets the level and the timing so as to allow the width of the data holding time indicated by the specification of the liquid crystal panel module, and inspects the operation margin of the TFT liquid crystal panel 21.

In the conventional actual driving inspection apparatus, such an operation margin cannot be inspected. Therefore, if the writing time or the data holding time is changed on the user side, the TFT liquid crystal panel 21 does not light up normally. there is a possibility.

Next, the data writing time and the data holding time will be briefly described. FIG. 3 is a diagram showing an equivalent circuit of the TFT liquid crystal panel 21 shown in FIG. Here, the writing time means the auxiliary capacitance C _CS and the liquid crystal capacitance C _LC
To charge the signal input from the data line 23a during the time when the TFT is turned on, that is, the charging time.

On the other hand, the data holding time means that the charge charged in the auxiliary capacitor _CCS and the liquid crystal capacitor _CLC , that is, the write data, when the charge is completed by the writing and the TFT is turned off after the writing time is completed. Means the time to be held. The writing time and the data holding time are determined not only by the defect of the TFT liquid crystal panel 21 but also
It also changes due to variations in characteristics. Therefore, if the writing time and the data holding time are made variable, it is possible to detect a defect and a characteristic defect of the liquid crystal panel.

As described above, in the present embodiment,
Since the drive signal generation device 11 capable of changing the level setting and the timing setting of the power supply and the control signal supplied to the liquid crystal driver IC 12 is provided, the liquid crystal panel 1
4 can be performed. In addition, by this operation margin inspection, defects that are potentially present in the liquid crystal panel 14 can be made obvious, and defective products can be eliminated early.
The drive signal generator 11 does not necessarily need to be newly developed, but is a signal generator having a specification capable of controlling a liquid crystal driver IC such as a commercially available multi-channel output signal generator or a controller capable of outputting a control signal. Is fine.

[0025]

As described above in detail, the first aspect of the present invention is configured such that the power supply and the control signal are supplied to the liquid crystal driver IC, and the drive signal generating means for directly controlling the liquid crystal driver IC is provided. The following effects can be obtained. 1) By inspecting the operation margin of the liquid crystal panel, a potential defect in the liquid crystal panel can be revealed, and defective products can be eliminated at an early stage. 2) The development period of an inspection head, that is, the development period as an inspection device, which has conventionally been required to incorporate a drive signal control circuit board used to control a liquid crystal driver IC into the inspection device, has been shortened, and thus new. This can contribute to the early mass production of liquid crystal panels.

In the second invention, the power supply for driving the liquid crystal driver IC and the level and timing of the control signal are variably controlled in order to inspect the operation margin of the liquid crystal panel. It can be checked whether or not the displayed operation can be performed.

A third invention is a liquid crystal driver IC
A driving signal generating means for supplying a power supply and a control signal to the liquid crystal driver IC, and variably controlling a writing time for turning on the TFT and a holding time for holding the writing data. Since the panel is configured to be inspected for defects and characteristic defects, the operation margin inspection of the TFT liquid crystal panel can be performed efficiently.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a schematic configuration of a liquid crystal panel inspection apparatus used in the present embodiment.

FIG. 2 is a diagram showing a configuration of a drive circuit of a TFT liquid crystal panel module unit.

FIG. 3 is a diagram showing an equivalent circuit of the TFT liquid crystal panel shown in FIG.

FIG. 4 is a diagram showing an example of the configuration of a conventional liquid crystal panel inspection device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 ... Drive signal generator 12 ... Liquid crystal driver IC 13 ... Inspection probe 14 ... Liquid crystal panel 15 ... Backlight 16 ... CCD camera unit 17 ... Defect detection device 18 ... CCD camera control device 21 ... TFT liquid crystal panel 22 ... Gate line liquid crystal Driver 22a: Gate line 23: LCD driver for data line 23a: Data line

Claims (3)

[Claims] 1. An inspection apparatus for a liquid crystal panel having at least a liquid crystal panel and a liquid crystal driver IC for lighting and displaying the liquid crystal panel, wherein a driving signal is supplied to the liquid crystal driver IC to inspect a display state of the liquid crystal panel. In the above, a power supply and a control signal are supplied to the liquid crystal driver IC,
An inspection apparatus for a liquid crystal panel, comprising: a driving signal generating means for directly controlling the liquid crystal driver IC. 2. The liquid crystal display according to claim 1, wherein the driving signal generator variably controls a power source for driving the liquid crystal driver IC and a level and timing of a control signal in order to inspect an operation margin of the liquid crystal panel. Inspection device for liquid crystal panel as described 3. The liquid crystal panel according to claim 1, wherein the liquid crystal panel is a panel in which a thin film transistor is formed for lighting display, and the liquid crystal panel variably controls a writing time for turning on the thin film transistor and a holding time for holding write data. 2. The liquid crystal panel inspection device according to claim 1, wherein the inspection is performed for defects and characteristic defects.