JP3220633B2 - Crosstalk inspection method and crosstalk inspection apparatus for liquid crystal display device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inspection method and an inspection apparatus for inspecting the display quality of a transmission type or reflection type liquid crystal display device.

[0002]

2. Description of the Related Art A liquid crystal display device has a structure in which a liquid crystal is sandwiched between transparent electrodes of a glass substrate facing each other, and an externally incident light is modulated by applying an electric signal between the electrodes. And displays information. Liquid crystal display devices are attracting attention as next-generation display devices because of their lower power consumption, thinner and lighter than CRT (Cathode-Ray Tube), and their production is increasing year by year. It is in. Since the production yield of the liquid crystal display device is not originally 100%, it is necessary to sufficiently inspect the display quality.

One of the display defects of the liquid crystal display device is a so-called crosstalk. This phenomenon is caused by TFT
In the case of an active matrix type liquid crystal display device having a switching element such as an MIM or an MIM, such a problem may occur when the ON / OFF characteristic of the switching element is poor, or when the resistance of a counter electrode facing the element side substrate is high. . Further, even in an STN type liquid crystal display device having no switching element, it is liable to occur remarkably due to its operation principle.

Hereinafter, the crosstalk phenomenon will be described with reference to FIGS. FIG. 6 shows a state in which there is no crosstalk phenomenon, and shows an active matrix type liquid crystal display device (hereinafter referred to as a TF) having a TFT as a switching element.
A black square pattern 103 is displayed in a white background display 102 on a T-LCD 101. here,
Reference numeral 104 denotes a source side circuit board, and 105 denotes a gate side circuit board. Note that the TFT-LCD 101 in FIG.
It is assumed that a non-selected pixel is a normally white type in which white display is performed. At this time, the originally black square pattern 1
03 is displayed in white, but if there is a crosstalk phenomenon, as shown in FIG. 7, a thin line 1 vertically or horizontally around the black square pattern 103 is formed.
06 is displayed.

Therefore, conventionally, in order to inspect the presence or absence of the crosstalk phenomenon, as shown in a flow chart of FIG. 8, a liquid crystal display device is set in the inspection device, and the above-described pattern is displayed on the liquid crystal display device. An operator visually inspected the presence or absence of a crosstalk phenomenon to determine pass / fail.

[0006]

However, when such an inspection is visually performed by an operator, the quality judgment criterion is not quantified, and the criterion is not constant even for the same operator. Accurate testing was not possible because the standards varied among individuals.
In addition, there is a problem that labor costs increase due to the inspection by the worker, which leads to an increase in cost.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and a liquid crystal display which automatically performs a crosstalk inspection of a liquid crystal display device, numerically manages quality judgment criteria, and efficiently performs a highly accurate inspection. It is an object of the present invention to provide an apparatus inspection method and an inspection apparatus.

[0008]

In order to achieve the above object, the present invention provides the following configuration and means.

The method for inspecting a liquid crystal display device according to the present invention comprises the steps of: displaying the entire liquid crystal display device in white; and measuring the luminance of a predetermined portion of the liquid crystal display device in which the entire display is performed in white.
In the background white display, do not include the predetermined portion where the luminance is measured.
A step of displaying a black pattern of a predetermined shape have a step of measuring the luminance of the predetermined portion in the vicinity of the black pattern, the luminance of the predetermined portion when the are all white display,
Digitizing the luminance of the predetermined portion near the black pattern when displaying the black pattern, and storing the numerical value;
A step of comparing and calculating the stored plurality of numerical values; and a step of determining acceptability of the liquid crystal display device based on the comparison result.

In the above-mentioned method for inspecting a liquid crystal display device, the black pattern has a rectangular shape having two sides parallel to a scanning signal line and a data signal line arranged on a panel of the liquid crystal display device, and A predetermined portion of the liquid crystal display device for measuring the distance is on a perpendicular line of each side of the square.

The inspection apparatus for a liquid crystal display device according to the present invention comprises a transporting means for transporting the liquid crystal display device to an inspection position, and a liquid crystal for inspecting a display state by inputting a drive signal to the liquid crystal display device at the inspection position. In the inspection device for a display device, an inspection signal generating means for displaying the liquid crystal display device conveyed to the inspection position on the entire surface in white or displaying a black pattern in the center of the background white screen, and the white display on the liquid crystal display device
A luminance measuring means for measuring the luminance of a predetermined portion of the area; a storage means for quantifying the luminance when displaying the entire white and the luminance when displaying the black pattern; and a comparing means for comparing and calculating the plurality of stored numerical values. A calculating means; and a judging means for judging pass / fail of the liquid crystal display device based on a result of the comparing / calculating means.

Further, in the inspection device for a liquid crystal display device, the black pattern has a rectangular shape having two sides parallel to a scanning signal line and a data signal line arranged on a panel of the liquid crystal display device, and A predetermined portion of the liquid crystal display device for measuring the distance is on a perpendicular line of each side of the square.

In the inspection apparatus for a liquid crystal display device, a cassette for the liquid crystal display device before the inspection, a loader for setting the liquid crystal display device before the inspection at the inspection position from the cassette, and a non-defective product after the inspection. A liquid crystal display device cassette, a liquid crystal display device cassette determined to be defective after inspection, and an unloader for storing the inspected liquid crystal display device in each cassette based on the result of the determination means from the inspection position. , Is provided.

Hereinafter, the operation of the above configuration will be described.

The method for inspecting a liquid crystal display device according to the present invention comprises the steps of: displaying the entire liquid crystal display device in white; and measuring the luminance of a predetermined portion of the liquid crystal display device in which the entire display is performed in white.
In the background white display, do not include the predetermined portion where the luminance is measured.
A step of displaying a black pattern of a predetermined shape have a step of measuring the luminance of the predetermined portion in the vicinity of the black pattern, the luminance of the predetermined portion when the are all white display,
Digitizing the luminance of the predetermined portion near the black pattern when displaying the black pattern, and storing the numerical value;
A step of comparing and calculating the stored plurality of numerical values; and a step of determining the quality of the liquid crystal display device based on the result of the comparison. The determination can be digitized, and the display inspection can be performed efficiently.

In the above-mentioned method for inspecting a liquid crystal display device, the black pattern has a rectangular shape having two sides parallel to a scanning signal line and a data signal line disposed on a panel of the liquid crystal display device, and Since the predetermined portion of the liquid crystal display device for measuring the position is on the perpendicular to each side of the square, the area where the crosstalk is likely to occur can be measured, so that a highly accurate inspection can be performed.

The inspection apparatus for a liquid crystal display device according to the present invention comprises a transporting means for transporting the liquid crystal display device to an inspection position, and a liquid crystal for inspecting a display state by inputting a driving signal to the liquid crystal display device at the inspection position. In the inspection device for a display device, an inspection signal generating means for displaying a liquid crystal display device conveyed to the inspection position on the entire surface in white or displaying a black pattern in the center of a background white screen, and a white display on the liquid crystal display device
A luminance measuring means for measuring the luminance of a predetermined portion of the area; a storage means for quantifying the luminance when displaying the entire white and the luminance when displaying the black pattern; and a comparing means for comparing and calculating the plurality of stored numerical values. The above-described inspection of the liquid crystal display device can be performed by including the calculating unit and the determining unit that determines the quality of the liquid crystal display device based on the result of the comparing / calculating unit.

In the inspection apparatus for a liquid crystal display device, the black pattern has a rectangular shape having two sides parallel to a scanning signal line and a data signal line arranged on a panel of the liquid crystal display device, and The above-mentioned inspection accuracy of the liquid crystal display device can be improved because the predetermined portion of the liquid crystal display device for measuring the position is on a perpendicular line of each side of the rectangular shape.

In the inspection apparatus for a liquid crystal display device, a cassette for the liquid crystal display device before the inspection, a loader for setting the liquid crystal display device before the inspection at the inspection position from the cassette, and a non-defective product after the inspection. A liquid crystal display device cassette, a liquid crystal display device cassette determined to be defective after inspection, and an unloader for storing the inspected liquid crystal display device in each cassette based on the result of the determination means from the inspection position. , It is possible to send the liquid crystal display device determined to be good or bad to the next step without mistake.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to FIGS.

FIG. 1A is a schematic view of the entire inspection apparatus for a liquid crystal display device according to the present invention as viewed from above, and FIG.
Fig. 2 is a schematic view of the inspection device as viewed from the side.

As shown in FIG. 1, the inspection apparatus for a liquid crystal display device according to the present embodiment inspects the loader 3 for transporting the liquid crystal display device 2 into an inspection box 5 and the liquid crystal display device 2 after the inspection. And an unloader 7 that discharges outside the box 5. A loader-side shutter 4 and an unloader-side shutter 6 are provided on the loader 3 side and the unloader 7 side of the inspection box 5, respectively.

The shutters 4 and 6 are provided to prevent dust and the like from entering the inspection box 5 and to keep the inside of the inspection box 5 in a dark room.

Reference numeral 1 denotes a cassette for accommodating the liquid crystal display device before inspection. The loader 3 sucks the liquid crystal display device 2 before inspection from the cassette 1 and transports the liquid crystal display device 2 into the inspection box 5. Has become. On the other hand, reference numerals 8 and 9 denote cassettes for accommodating the liquid crystal display device after the inspection, and the unloader 7 sucks the liquid crystal display device 2 after the inspection and discharges it to the outside of the inspection box 5, and the cassettes 8, 9
Can be transported to

As described above, a plurality of cassettes accommodating the liquid crystal display device after the inspection are prepared because the inspected liquid crystal display device can be replaced with a non-defective one based on the result of the inspection. The reason is to sort those having possible defects, those having irreparable defects, and the like.

FIG. 2 is a schematic view of the inside of the inspection box 5 in FIG. In the inspection box 5, the loader 3
Is provided with a suction board 10 for fixing the liquid crystal display device 11 conveyed by the device at a predetermined position.

A prober mounting board 1 provided with a prober 12 in contact with an electrode terminal provided on the liquid crystal display device 11 around the suction board 10.
3 are provided. An inspection signal generating means (not shown) is provided in the suction board 10, and a signal from the signal generating means is input to each electrode terminal of the liquid crystal display device 11 via the prober 12, whereby the liquid crystal display The device 11 is driven.

Air cylinders 14 are provided below the prober mounting board 13, respectively. The air cylinders 14 move the prober 12 and the prober mounting board 13 up and down to turn on the driving of the liquid crystal display device 11. / OFF is switched. When the liquid crystal display device 11 on the suction board 10 is replaced, the prober 12 and the prober mounting board 13 are raised by the air cylinder 14 to a position separated from the liquid crystal display device 11.

Although the air cylinder 14 is used in this embodiment as a method for moving the prober 12 and the prober mounting board 13 up and down, a drive mechanism such as a motor may be used.

Further, inside the suction board 10,
A backlight (not shown) that irradiates light from the back of the liquid crystal display device 11 when performing a display test is provided. The light emitted by the backlight is transmitted to the liquid crystal display device 11.
, The ON / OFF state of the voltage applied to the liquid crystal display device 11 can be confirmed.

Further, above the suction board 10 in the inspection box 5, a CCD camera (brightness measuring means) 1 for collectively measuring the brightness of a predetermined portion of the liquid crystal display device 11 is provided.
5 are provided. In place of the CCD camera 15, a luminance meter may be provided at a position corresponding to each measurement point, and means for separately measuring the luminance at each measurement point may be provided.

Further, outside the inspection box 5, the C
A storage unit 16 connected to the CD camera 15, a comparison / calculation unit 17 connected to the storage unit 16, and a determination unit 18 connected to the comparison / calculation unit 17 are provided. The storage means 16 performs a process of digitizing and storing the luminance measured by the CCD camera 15, and the comparing / calculating means 17 compares and calculates a plurality of numerical values stored in the storing means 16. Processing is performed,
The determination unit 18 performs a process of determining the quality of the liquid crystal display device 11 based on the calculation result performed by the comparison / calculation unit 17. Further, the judging means 18 is connected to the unloader 7, and it is determined whether the liquid crystal display device after the inspection is to be stored in any one of the cassettes 8 and 9 based on the pass / fail result of the liquid crystal display device 11. You.

Next, the inspection method of the liquid crystal display device of the present invention and the operation of the inspection device of the liquid crystal display device of the present invention will be described in detail below.

FIG. 3 is a flowchart showing the outline of the inspection method of the liquid crystal display device of the present invention. As can be seen from FIG.
In the inspection method for a liquid crystal display device according to the present invention, the liquid crystal display device, which is a non-inspection object, is first entirely displayed in white, and the luminance of a predetermined portion (hereinafter referred to as first luminance) is measured. A black pattern is displayed at the center, the luminance at a predetermined location (hereinafter, referred to as second luminance) is measured, and the first luminance and the second luminance are compared and calculated to determine whether the liquid crystal display device as a non-inspection object is good or bad. Is automatically performed.

Next, an operation of inspecting a liquid crystal display device using the inspection device for a liquid crystal display device of the present invention will be described.

First, a liquid crystal display device before inspection is set in the cassette 1 on the loader side shown in FIG. Then, the liquid crystal display device 2 before inspection is taken out by the loader 3 and transported to a position before the loader side shutter 4 attached to the inspection box 5 on the loader side. Thereafter, the loader-side shutter 4 is opened, and the liquid crystal display device 2 is transported into the inspection box 5 by the loader 3.

Thereafter, as shown in FIG. 2, the liquid crystal display device is set at a predetermined position on the suction board 10 by the loader 3, and the loader 3 is retracted from the inspection box 5 and attached to the inspection box 5. The loader side shutter 4 closes. Next, the prober mounting board 13 is operated by an air cylinder to bring the prober 12 mounted on the prober mounting board 13 into contact with the electrode terminal of the liquid crystal display device 11. Thereafter, the inspection signal generated by the inspection signal generation means (not shown) provided in the suction board 10 is transmitted to the prober 1.
2 and simultaneously drive the backlight (not shown) provided on the suction board 10 to illuminate the liquid crystal display device 11 from the back, thereby displaying the liquid crystal display device 11 in white. Let it.

Then, as shown in FIG. 4, the luminances a ₁ , a ₂ , a ₃ , and a ₄ at the measurement points A ₁ , A ₂ , A ₃ , and A ₄ are measured by the CCD camera 15 and stored in a memory or the like. Is temporarily stored in the storage means 16. Next, as shown in FIG. 5, a square black pattern 1
9 is displayed, and the same locations B ₁ , B ₂ ,
The luminances b ₁ , b ₂ , b ₃ , and b ₄ at B ₃ and B ₄ are measured by the luminance measuring means 15 and are temporarily stored in the storage means 16.

At this time, the black pattern 19 has a rectangular shape having two sides parallel to the scanning signal lines and the data signal lines of the liquid crystal display device, and the measurement points A ₁ , A ₂ , A ₃ ,
A ₄ , B ₁ , B ₂ , B ₃ , and B ₄ need to be as close as possible to the black pattern and on the perpendicular to each side of the pattern. This is because the crosstalk phenomenon occurs in the upper, lower, left, and right directions with respect to the black pattern, and a region closer to the black pattern has a property of being more noticeable. The measurement points A ₁ , A ₂ , A ₃ , A ₄ , B ₁ , B ₂ ,
The size of each of B ₃ and B ₄ is preferably one pixel or more including three picture elements of red, green and blue.

Next, the first luminances a ₁ , a ₂ , a ₃ , a ₄ stored in the storage means 16 by the comparing / calculating means 17 are shown.
And the second luminances b ₁ , b ₂ , b ₃ , b ₄ are substituted into the following conditional expressions, and based on the result, the quality of the liquid crystal display device 11 is determined by the determination means 18.

[0041]

(Equation 1)

Here, X in the conditional expression represents a margin for judging a non-defective product, and the relationship between the amount of crosstalk and the defect level can be determined by setting this value. In other words, if the amount of crosstalk is slight, if it is determined that the product is good, the value of X should be set to a relatively large value.

When the inspection of the liquid crystal display device is completed as described above, the unloader-side shutter 6 of the inspection box 5 is opened, and the unloader 7 enters the inspection box 5 from the unloader-side shutter 6 and The liquid crystal display device 11 is lifted and pulled out of the inspection box 5, the unloader side shutter 6 is closed, and the liquid crystal display device after inspection is transported to the cassette 8 or 9 by the unloader 7.

At this time, the unloader 7 automatically sorts the liquid crystal display device after the inspection into the non-defective cassette 8 and the defective cassette 9 based on the judgment result made by the judgment means 18. Has become.

In the inspection apparatus for a liquid crystal display device according to the present invention, it is possible to change the position of a preset black pattern and the position of each measurement point so as to be compatible with liquid crystal display devices of various sizes. You may do it.

Further, in the present embodiment, the liquid crystal display device is in a panel state before mounting the drive circuit. However, even in a module state after the drive circuit is mounted, the liquid crystal display device does not need to be mounted on the drive circuit. If an inspection signal is generated, an inspection can be performed using the inspection device for a liquid crystal display device of the present invention.

Further, instead of the above conditional expression 1, the quality of the liquid crystal display device may be determined by comparing and calculating the luminance of each portion as in the following conditional expression 2. At this time, the inspection accuracy can be improved as compared with the case where the conditional expression 1 is used.

[0048]

(Equation 2)

If a plurality of values of X are prepared as in the following conditional expression 3, it is possible to rank defective products.

[0050]

(Equation 3)

[0051]

As described above, in the method for inspecting a liquid crystal display device according to the present invention, the step of displaying the entire surface of the liquid crystal display device and the measurement of the luminance of a predetermined portion of the liquid crystal display device where the entire white display is performed are measured. Process and the brightness in the white background display
A step of displaying a black pattern of a predetermined shape not including the predetermined portion of the measurement of the previous vicinity of the black pattern
A step of measuring the luminance of the serial predetermined portion, the luminance of the predetermined portion when the are all white display, digitizes the luminance of the predetermined portion in the vicinity of said black pattern when displaying the black pattern, The method includes a step of storing, a step of comparing and calculating the stored plurality of numerical values, and a step of judging the quality of the liquid crystal display device based on the result of the comparison. This makes it possible to digitize the pass / fail judgment, which has been possible, so that the display inspection can be performed efficiently. Furthermore, since the labor cost can be reduced, there is an effect that the cost can be reduced.

In the above-mentioned method for inspecting a liquid crystal display device, the black pattern is a quadrangular shape having two sides parallel to a scanning signal line and a data signal line arranged on a panel of the liquid crystal display device, and Since the predetermined portion of the liquid crystal display device for measuring the position is on the perpendicular of each side of the rectangular shape, it is possible to measure the area where the crosstalk is likely to occur, so that a highly accurate inspection can be performed.
This has the effect.

The inspection apparatus for a liquid crystal display device according to the present invention comprises a transporting means for transporting the liquid crystal display device to an inspection position, and inputs a driving signal to the liquid crystal display device at the inspection position to check the display state. In the inspection device for a display device, an inspection signal generating means for displaying a liquid crystal display device conveyed to the inspection position on the entire surface in white or displaying a black pattern in the center of a background white screen, and a white display on the liquid crystal display device
A luminance measuring means for measuring the luminance of a predetermined portion of the area; a storage means for quantifying the luminance when displaying the entire white and the luminance when displaying the black pattern; and a comparing means for comparing and calculating the plurality of stored numerical values. The provision of the calculating means and the judging means for judging the quality of the liquid crystal display device based on the result of the comparing / calculating means provides an effect that the above-described inspection of the liquid crystal display device can be performed. .

Further, in the inspection device for a liquid crystal display device, the black pattern has a rectangular shape having two sides parallel to a scanning signal line and a data signal line disposed on a panel of the liquid crystal display device, and Since the predetermined portion of the liquid crystal display device for measuring the position is on a perpendicular line of each side of the rectangular shape, there is an effect that the inspection accuracy of the liquid crystal display device described above can be increased.

In the inspection apparatus for the liquid crystal display device, a cassette for the liquid crystal display device before the inspection, a loader for setting the liquid crystal display device before the inspection at the inspection position from the cassette, and a non-defective product after the inspection. A liquid crystal display device cassette, a liquid crystal display device cassette determined to be defective after inspection, and an unloader for storing the inspected liquid crystal display device in each cassette based on the result of the determination means from the inspection position. , It is possible to send the liquid crystal display device determined to be good or bad to the next process without mistake, and it is possible to perform an efficient display inspection.

[Brief description of the drawings]

FIG. 1 is a schematic view of an entire inspection device for a liquid crystal display device of the present invention.

FIG. 2 is a schematic view of the inspection box in FIG. 1;

FIG. 3 is a flowchart schematically showing an inspection method of the liquid crystal display device of the present invention.

FIG. 4 is a diagram showing points at which luminance is measured when the entire surface of the liquid crystal display device according to the inspection method of the liquid crystal display device of the present invention is white-displayed.

FIG. 5 is a diagram showing points at which luminance is measured when a black pattern is displayed on the liquid crystal display device according to the liquid crystal display device inspection method of the present invention.

FIG. 6 is a diagram showing a display screen of the liquid crystal display device when there is no crosstalk phenomenon.

FIG. 7 is a diagram showing a display screen of the liquid crystal display device when there is a crosstalk phenomenon.

FIG. 8 is a flowchart showing an outline of a conventional inspection method for a liquid crystal display device.

[Explanation of symbols]

Reference Signs List 1 cassette 2 liquid crystal display device 3 loader 4 loader side shutter 5 inspection box 6 unloader side shutter 7 unloader 8 cassette 9 cassette 10 suction board 11 liquid crystal display device 12 prober 13 prober mounting board 14 air cylinder 15 brightness measurement means 16 storage means 17 comparison operating means 18 judging unit 19 black pattern A ₁ to A ₄ luminance measurement points B ₁ .about.B ₄ luminance measurement points

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G01M 11/00-11/02 G02F 1/13-1/137

Claims (5)

(57) [Claims] 1. A test method for inspecting the display quality of the liquid crystal display device, a step of all white display of the liquid crystal display device, a step of measuring the luminance of a predetermined portion of the total white display is a liquid crystal display device, background In the white display, do not include the predetermined location where the luminance was measured.
A step of displaying a black pattern of a predetermined shape have a step of measuring the luminance of the predetermined portion in the vicinity of the black pattern, the luminance of the predetermined portion of the time that is all white display, and displaying the black pattern In front of the vicinity of the black pattern at the time
Digitizing and storing the brightness of the predetermined location, comparing and calculating the stored plurality of numerical values, and determining the acceptability of the liquid crystal display device based on the comparison result. Of a liquid crystal display device characterized by including
Crosstalk inspection method. 2. The liquid crystal display device according to claim 2, wherein the black pattern has a rectangular shape having two sides parallel to a scanning signal line and a data signal line disposed on a panel of the liquid crystal display device. 2. The crosstalk inspection method for a liquid crystal display device according to claim 1, wherein the vertical axis is on a perpendicular line of each side of the quadrangular shape. Wherein a conveying means for conveying the liquid crystal display device in the testing position, by inputting a driving signal to the liquid crystal display device in the testing position, the testing device of a liquid crystal display apparatus for inspecting a display state, the test The liquid crystal display device transported to the position is displayed entirely in white,
Alternatively, an inspection signal generating means for displaying a black pattern at the center of the background white screen, a luminance measuring means for measuring the luminance of a predetermined portion of the white display area of the liquid crystal display device, Storage means for digitizing and storing the brightness of the liquid crystal display; comparison / calculation means for comparing / calculating the plurality of stored numerical values; and determining whether the liquid crystal display device is good or bad based on the result of the comparison / calculation means. And a crosstalk inspection device for a liquid crystal display device. 4. The liquid crystal display device according to claim 1, wherein the black pattern has a rectangular shape having two sides parallel to a scanning signal line and a data signal line arranged on a panel of the liquid crystal display device. 4. The crosstalk inspection device for a liquid crystal display device according to claim 3, wherein the vertical axis is on a perpendicular line of each side of the quadrangular shape. 5. A cassette for a liquid crystal display device before inspection, a loader for setting the liquid crystal display device before inspection at the inspection position from the cassette, a cassette for liquid crystal display device determined to be non-defective after inspection, A liquid crystal display device cassette determined to be a post-defective product, and an unloader configured to store the inspected liquid crystal display device in each cassette based on a result of the determination unit from the inspection position. Item 5. A crosstalk inspection device for a liquid crystal display device according to item 3 or 4.