KR20040095071A - Apparatus and method for inspecting display device - Google Patents

Abstract

PURPOSE: An apparatus for testing a display device and a testing method using the apparatus are provided to detect a sensing element having a defect and the position of the sensing element. CONSTITUTION: An apparatus(100) for testing a display device(1) having pixels for displaying images and sensing elements(30) each of which is arranged between adjacent pixels to output sense signals in response to external stimulus includes an external stimulus applying unit(200) and a processing unit(600). The external stimulus applying unit applies external stimulus to each of the sensing elements. The processing unit detects the sense signal output from each sensing element in response to the external stimulus to process a defect of each sensing element.

Description

Inspection device for display device and inspection method using same {APPARATUS AND METHOD FOR INSPECTING DISPLAY DEVICE}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inspection apparatus for a display device and an inspection method using the same, and more particularly, to an inspection apparatus for a display device for detecting whether or not the photo-sensing elements formed in a liquid crystal display device are defective and an inspection method using the same.

In general, when a touch screen image display apparatus selects a part of an image displayed on a screen using a human hand or an object, information corresponding to the selected content is displayed on the screen. In the touch screen type image display device, its use is increasing due to the convenience of not requiring separate input devices such as a keyboard and a mouse.

The touch screen image display apparatus further includes a liquid crystal display panel displaying an image and a touch panel detecting a position of an instruction selected by a user.

The touch panel is stacked on the display surface of the liquid crystal display panel on which an image is displayed. The touch panel includes a first substrate, a second substrate spaced apart from the first substrate by a predetermined distance, and first and second transparent electrodes respectively formed on surfaces of the first and second substrates facing each other.

When the touch panel is stacked on the liquid crystal display panel as described above, air is present between the liquid crystal display panel and the touch panel, and the optical characteristics of the touch type image display apparatus are deteriorated due to the air. Then, the thickness of the touch screen type image display apparatus is also increased.

In order to solve this problem, a liquid crystal display panel of a light sensing type has been developed in which a light sensing unit for outputting position information in response to an external stimulus, in particular, light and a pixel unit for displaying an image are formed together.

A photosensitive liquid crystal display panel is largely composed of a TFT substrate, a color filter substrate, and a liquid crystal layer injected into the TFT substrate and the color filter substrate. The TFT substrate includes a pixel portion and a light sensing portion. The pixel portion includes a plurality of gate lines elongated in a first direction of the TFT substrate, data lines elongated in a second direction perpendicular to the gate line, and a first thin film transistor connected to the gate line and the data line. TFT) and a transparent electrode or a reflective electrode connected to the first TFT.

The light sensing unit includes a first sensor line formed in a second direction and outputting a position information signal, a second sensor line formed in a first direction, and a sensing element. The sensing element is constituted by a second TFT and a second TFT electrically connected to a second sensor line and a data line and operated by light provided from the outside, and a third TFT electrically connected to a first sensor line and a gate line. do.

The gate lines are all connected to the first short bar and the data lines are all connected to the second short bar in order to test whether the pixel portion of the liquid crystal display panel of the light sensing type configured as described above is defective.

In this state, as the gate driving voltage is applied to the first short bar, the data driving voltage is applied to the second short bar, and light is applied to the rear surface of the photosensitive liquid crystal display panel, the screen of the photosensitive liquid crystal display panel is changed. It turns white or black. In this case, when a defect occurs in the pixel portion formed at a predetermined position, the defective portion is displayed in its original state, that is, black on a screen that has changed to white and white on a screen that has changed to black. Therefore, the defective pixel portion can be easily detected in the photosensitive liquid crystal display panel.

However, there is a problem in that the reliability of the product is deteriorated because the detection of defective elements formed in the photosensitive liquid crystal display panel cannot be tested.

Accordingly, the present invention has been made in view of such a conventional problem, and a first object of the present invention is to apply an external stimulus to each sensing element formed on a photo-responsive liquid crystal display panel individually and to determine whether each sensing element is defective or not. An inspection apparatus of a display device for detecting the position of the generated sensing element is provided.

It is a second object of the present invention to provide an inspection method of a display device that inspects the presence or absence of defective sensing elements by using the inspection device of the display device.

1 is a plan view of an inspected display apparatus to which an inspecting apparatus of a display apparatus according to the present invention is applied.

2 is a cross-sectional view taken along the line A-A of FIG. 1.

3 is an equivalent circuit diagram of each pixel and the light sensing unit of the TFT substrate.

4 is a block diagram of an inspection apparatus of a display device according to the present invention.

5 is a cross-sectional view of an optical supply apparatus according to a first exemplary embodiment of the present invention installed on an upper surface of a display device to be inspected.

FIG. 6 is an enlarged cross-sectional view of the light supply device and the test target display device illustrated in FIG. 5.

7 is an equivalent circuit diagram of a TFT substrate of the light supply apparatus according to the first embodiment of the present invention.

8 is a cross-sectional view of an optical supply apparatus according to a second exemplary embodiment of the present invention installed on an upper surface of a display device to be inspected.

9 is a perspective view of a light supply apparatus according to a second embodiment of the present invention.

10 is a perspective view of an optical supply apparatus according to a third exemplary embodiment of the present invention, installed on an upper surface of a display device to be inspected.

11 is a flowchart illustrating a display device inspection method according to the present invention.

12 is a view for explaining a method of testing the sensing elements of the display device under test using the test device according to the present invention.

In order to implement the first object of the present invention, the present invention provides a method for inspecting an inspected display device including pixels for displaying an image and sensing elements disposed between the pixels and outputting a sensing signal by an external stimulus. A display unit including external stimulus applying means for individually applying an external stimulus to each sensing element, and a processing unit for detecting whether or not each sensing element is defective by detecting a sensing signal output from each sensing element by the external stimulus Provide an inspection device for the device.

In order to implement the second object of the present invention, the present invention provides a device for inspecting an inspected display device including pixels for displaying an image and sensing elements disposed between the pixels and outputting a sensing signal by an external stimulus. A method of inspecting a display device, the method comprising individually applying an external stimulus to the sensing elements and determining whether the sensing elements are defective by detecting a sensing signal output from each sensing element by the external stimulus. do.

According to the present invention, when an external stimulus applying device is installed on a photosensitive liquid crystal display panel and an external stimulus is individually applied to each sensing element, a signal is output only to the sensing element receiving the external stimulus and input to the processing unit. Therefore, the processing unit can detect the presence or absence of the failure of each sensing element, can identify the position of the sensing element in which the failure occurs, thereby improving the reliability of the liquid crystal display panel of the light sensing method.

Hereinafter, for convenience of description, the structure of a light sensing type liquid crystal display panel (hereinafter referred to as an inspection target display device) will be described before describing the inspection device of the display device according to the present invention.

1 is a plan view of a test target display device to which the test apparatus of the display device according to the present invention is applied. 2 is a cross-sectional view taken along the line A-A of FIG. 1.

1 and 2, the liquid crystal display panel 1 includes a TFT substrate 10, a color filter substrate 60 facing the TFT substrate 10, and a TFT substrate 10 between the color filter substrate 60. The liquid crystal layer 70 is interposed therebetween.

3 is an equivalent circuit diagram of each pixel and the light sensing unit of the TFT substrate.

2 and 3, the pixel unit 20, the light sensing unit 30, and the transparent electrode 40 are formed on the TFT substrate 10. The pixel portion 20 and the light sensing portion 30 are arranged in a matrix form on the TFT substrate 10. In this case, it is preferable that one optical sensing unit 30 is formed for each of the plurality of pixel units 20. The light sensing units 30 are formed one by one at intervals of about 2 mm on the TFT substrate.

The pixel portion 20 includes a plurality of gate lines 22, a plurality of data lines 24, and a first TFT 26 disposed at an intersection of the gate lines 22 and the data lines 24.

The gate line 22 is formed long along the first direction of the TFT substrate 10. The data lines 24 are formed long along the second direction of the TFT substrate 10 orthogonal to the gate lines 22.

The first TFT 26 includes a gate electrode 26a branched from the gate line 22, a source electrode 26b branched from the data line 24, and a drain electrode 26c connected to the transparent electrode 40.

The light detector 30 detects light input from the outside of the display apparatus 1 to output a predetermined signal. 2 and 3, the light detector 30 includes a first sensor line 32, a second sensor line 34, and a sensing element 35.

The first sensor line 32 is spaced apart from the data line 24 and is formed long in the first direction of the TFT substrate 10. The first sensor line 32 is formed on the same layer as the data line 24 and is electrically insulated from the data line 24.

The second sensor line 34 is spaced apart from the gate line 22 and formed long in the second direction of the TFT substrate 10. The second sensor line 34 is formed on the same layer as the gate line 22 and is electrically insulated from the gate line 22.

The sensing element 35 is composed of a second TFT 36 and a third TFT 38.

The second TFT 36 is driven by the light L provided from the outside. The second TFT 36 is a gate electrode 36a branched from the second sensor line 34, a source electrode 36b branched from the data line 24, and a drain electrode 36c connected to the third TFT 38. ).

The third TFT 38 branches from the gate electrode 38a branched from the gate line 22, the source electrode 38b connected to the drain electrode 36c of the second TFT 36, and the first sensor line 32. Provided drain electrode 38c.

Referring to FIG. 2, the transparent electrode 40 is formed on the organic film 39 covering the first to third TFTs 26, 36, and 38, and the drain electrode 26c of the first TFT 26. It is electrically connected to the first TFT 26 through a contact hole CON exposing the light.

Referring to FIG. 2, the reflective electrode 50 is formed on the transparent electrode 40, and a part of the transparent electrode 40 and a portion corresponding to the second TFT 36 of the reflective electrode 50 are opened. The reflective electrode 50 formed as described above covers the first and third TFTs 26 and 38 to prevent the first and third TFTs 26 and 38 from reacting to light input from the outside. When the reflective electrode 50 is not formed, the third TFT 38 blocks light from being incident by a separate layer.

In FIG. 1, reference numeral 80 is a first short bar connecting all of the second sensor lines 34 to test the pixel unit 20 and the light sensing unit 30. In FIG. 1, reference numeral 90 denotes a second short bar connecting all of the first sensor lines 32. The first and second short bars 80 and 90 are removed when the test of the pixel unit 20 and the light detector 30 is completed.

In the present exemplary embodiment, the short bars for testing the pixel unit 20 are the same as in the prior art and are omitted for convenience of description. When the light sensing unit 30 is tested, all the data lines and the gate lines are the same for the test. Drive voltage is applied.

Hereinafter, exemplary embodiments of an inspection apparatus for a display device according to the present invention will be described in detail with reference to the accompanying drawings.

4 is a block diagram of an inspection apparatus of a display device according to the present invention.

Referring to FIG. 4, the inspection apparatus 100 for testing the light sensing element 30 of the inspected display apparatus 1 includes a light supply apparatus 200, a processing unit 600, and a display unit 700. .

The light supply device 200 is electrically connected to the processing unit 600 and individually applies an external stimulus to the light sensing element 30 under the control of the processing unit 600. In more detail, the light supply device 200 is a light supply device for applying light corresponding to the position of each sensing element 30.

The processing unit 600 is electrically connected to the first and second short bars 80 and 90 to apply a driving signal to the display device 1 under test as in the related art, and receives an external stimulus. As illustrated in FIG. 3, the sensing signal output from the sensing signal is detected through the first sensor line 32 and the second sensor line 34 to detect whether each sensing element is defective. The processing unit 600 includes a data storage unit 610 and a calculation module 620.

The data storage unit 610 stores the position data of the photosensitive device 30 to which the external stimulus is applied and whether the photosensitive device 30 to which the external stimulus is applied is defective. The calculation module 620 determines the failure of the sensing element by using the position data and the defect data.

Meanwhile, the processing unit 600 may control the light supply apparatus 200 to generate light only at a predetermined portion corresponding to the sensing element 30 to be inspected.

The display unit 700 is electrically connected to the processing unit 600, and the defects of the light sensing elements 30 on the screen can be used so that an operator can check whether the sensing elements 30 are defective or where the defects are generated. Indicates presence

Embodiments of Optical Supply Device

Example 1

5 is a cross-sectional view of an optical supply apparatus according to a first exemplary embodiment of the present invention installed on an upper surface of a display device to be inspected. FIG. 6 is an enlarged cross-sectional view of the light supply device and the test target display device illustrated in FIG. 5.

5 to 6, the light supply device 200 is a liquid crystal display device including a liquid crystal display panel 210 and a light source 300.

The liquid crystal display panel 210 includes a TFT substrate 220, a color filter substrate 280 attached to face the TFT substrate 220, and a liquid crystal layer 290 interposed between the TFT substrate 220 and the color filter substrate 280. )

7 is an equivalent circuit diagram of a TFT substrate of the light supply apparatus according to the first embodiment of the present invention.

6 and 7, the TFT substrate 220 includes a plurality of gate lines 230, a plurality of data lines 240, a plurality of TFTs 250, and a plurality of pixel regions 260 in a matrix form. Is arranged.

The gate lines 230 are spaced apart from each other and formed to extend along the first direction of the TFT substrate 220. The data lines 240 are spaced apart from each other by a predetermined distance, and are formed long along the second direction of the TFT substrate 220 perpendicular to the gate lines 230.

The TFT 250 includes a gate electrode 252 branched from the gate line 230, a source electrode 254 branched from the data line 240, and a drain electrode 256 connected to the pixel region 260.

The pixel areas 260 are formed in portions corresponding to the second TFTs 36 of the display device 1 under test. Referring to FIG. 6, a transparent electrode 270 is covered in the pixel region 260, and the transparent electrode 270 is formed on an insulating film covering the TFT 250, and the drain electrode 256 of the TFT 250. It is electrically connected to the TFT 250 through a contact hole CON exposing the light. Light for testing whether the sensing elements 30 are defective is emitted through the pixel region 260 formed as described above, and the light emitted through the pixel region 260 is the second TFT of the display device 1 to be inspected. Is applied to (36).

The light source 300 is installed on the rear surface of the liquid crystal display panel 210 facing the TFT substrate 220, and supplies light for driving the liquid crystal display panel 210.

In addition to the liquid crystal device described above, an organic electroluminescent device, a plasma display device, a CRT device, and the like may be used as the ball supply device 200 that individually applies light to each sensing element 30 formed in the display device 1 under test. .

As in the present exemplary embodiment, when pixel regions 260 in which light is emitted are formed in portions corresponding to the second TFT 36 among the inspection elements 30 formed in the display apparatus 1 under test, the pixels are sequentially The region 260 can be driven to apply light to one second TFT 36 at a time. In addition, all of the pixel regions 260 formed in a portion corresponding to the second TFTs 36 connected to different first sensor lines 32 are simultaneously driven to apply light to the plurality of second TFTs 36 at one time. Can shorten the test time of the sensing elements 30.

Example 2

8 is a cross-sectional view of an optical supply apparatus according to a second exemplary embodiment of the present invention installed on an upper surface of a display device to be inspected. 9 is a perspective view of a light supply apparatus according to a second embodiment of the present invention.

8 and 9, the light supply device 200 includes an array substrate 400, a plurality of light emitting diodes 410, and a connection portion 420.

The array substrate 400 is formed in the same shape as the display device 1 to be inspected, and light emitting diodes 410 are provided on a surface facing the test display device 1.

As shown in FIG. 8, the light emitting diodes 410 are respectively provided in portions of the array substrate 400 corresponding to the second TFT 36 of the display device 1 under test. The light emitting diodes 410 generate light, and emit the generated light to the second TFT 36 of the display device 1 to drive the second TFT 36.

The connection unit 420 connects each of the light emitting diodes 410 and the processing unit () to transfer the driving signal output from the processing unit () to the light emitting diode 410.

The light generated from the light emitting diodes 410 installed in the light supply device 200 according to the present exemplary embodiment is the same as the light applied from the outside by the user when the user uses the display device 1 under test. Therefore, when the presence or absence of failure of the sensing elements 30 is tested using the light supply device 200 according to the present embodiment, the test reliability is higher than when the presence or absence of failure of the sensing elements 30 is tested using the first embodiment. This can be improved.

Example 3

10 is a perspective view of an optical supply apparatus according to a third exemplary embodiment of the present invention, installed on an upper surface of a display device to be inspected.

Referring to FIG. 10, the light supply device 200 includes a laser beam scanning device 500 and a transport device 520.

The laser beam scanning device 500 applies the laser beam 510 to the second TFT 36. The laser beam scanning apparatus 500 is composed of an exit port (not shown in the drawing) formed on the lower surface of the body 502 facing the body 502 and the inspection target display device 1. The width of the laser beam 510 emitted through the exit port should be smaller than the size of the second TFT 36.

Although not shown, the focal point of the laser beam 510 is formed inside the body 502 such that the laser oscillation unit generating the laser beam 510 and the width of the emitted laser beam 510 are smaller than the size of the second TFT 36. A focusing lens group for adjusting the speed is provided. The focusing lens group is provided between the laser oscillation unit and the exit port.

At least one laser beam scanning device 500 configured as described above is installed in the transfer device 520.

The transfer apparatus 520 may include a first guide bar 530 for moving the laser beam scanning apparatus 500 in the x-axis direction, a second guide bar 540 for moving the laser beam scanning apparatus 500 in the y-axis direction, and And a driving unit (not shown) for driving the first and second guide bars 530 and 540.

When the laser beam scanning device is used as the light supplying device as in the present embodiment, the laser beam scanning device continuously scans the laser beam and passes the inspection target display device. In this case, the signal is not output to the processing unit because the display device under test does not respond to the laser beam in the absence of the sensing element, but the laser beam scanning device moves while continuously scanning the laser beam, and then the laser is formed in the portion where the sensing element is formed. When the beam is positioned, the sensing element outputs a predetermined signal to the processing unit in response to the laser beam.

Embodiment of display device inspection method

11 is a flowchart illustrating a display device inspection method according to the present invention. 12 is a view for explaining a method of testing the sensing elements of the display device under test using the test device according to the present invention.

Referring to FIG. 11 or 12, an optical supply device is positioned on a display surface of a display device under test in which sensing elements are formed. Then, the first and second short bars and the processing unit formed in the test target display device are electrically connected to the light supply device and the processing unit.

As such, when the processing unit is electrically connected to the display device and the light supply apparatus under test, a driving signal is applied to the light supply device, a first signal is applied to the first short bar, and a second signal is applied to the second short bar. Is approved.

Here, as described in the first and second embodiments, in the case of using an optical supply device in which a pixel region or a light emitting diode is disposed in a portion corresponding to the second TFT of the display device under test, the pixel region selected by the driving signal of the processing unit Alternatively, light is generated from the light emitting diodes. Then, light is individually applied only to the second TFT formed at a position corresponding to the pixel region or the light emitting diode where light is generated (S10).

In the optical supply device, only one sensing element may be tested at a time by driving only one pixel area or light emitting diode sequentially, and a portion corresponding to the second TFTs 36 connected to different first sensor lines 32. Light may be applied to the plurality of second TFTs 36 at a time by driving all the pixel regions 260 formed at the same time.

On the other hand, when the laser beam scanning device is used as the light supply device as in the third embodiment, the laser beam scanning device continuously passes the laser beam scanning device while scanning the laser beam. In this case, when the display device to be inspected does not respond to the laser beam at the portion where there is no sensing element, and the laser beam is positioned at the portion where the sensing element is formed, only the second TFT formed at the portion where the laser beam is located responds to the laser beam.

When light is applied to any one or a plurality of sensing elements thus selected, the applied second TFT which is light is driven in response to the light. When the second TFT T2 is driven, the second signal provided to the source electrode of the second TFT T2 through the second short bar and the data line DL is output to the drain electrode of the second TFT.

Thereafter, in the state where the third TFT T3 is driven by the first signal provided to the first short bar and the gate line GL, the second signal output from the drain electrode of the second TFT T2 is the third TFT. A source electrode of T3 is provided. Accordingly, the second signal is output to the drain electrode of the third TFT (T3), and the second signal is output through the first sensor line SL1 connected to the drain electrode of the third TFT (T3).

The processing unit detects the second signal transmitted via the first sensor line (step 20).

Then, the processing unit determines whether each sensing element to which light is applied is normally driven or a defect is generated based on the input signal (step 30).

Here, when the second signal is input to the processing unit through the first sensor line, it is determined that the sensing device is normally driven, and when the second signal is not output through the first sensor line, it is determined that a failure occurs in the sensing device. . As described above, even when light is applied to each of the plurality of sensing elements at one time, light is applied through different first sensor lines.

If there is one sensing element to which light is applied or a sensing element which is determined to have a fault among a plurality of sensing elements to which light is applied, the position information of the sensing element having a fault is stored in the data storage unit (step 40 ).

Then, a signal indicating a position of a sensing element in which a failure has occurred and an electrical signal indicative of a position of a sensing element normally operating are transmitted to the display unit (step 50).

Then, after the display unit inputs the electrical signal transmitted from the processing unit, as shown in FIG. 12, the display unit divides the position of the sensing element from which the defect has occurred and the sensing element that normally operates so that the user can easily recognize the position on the screen. Mark on.

As described in detail above, the liquid crystal display device having the light sensing element can easily recognize whether the light sensing element is defective and thus it is easy to determine whether the light sensing element is defective.

In the detailed description of the present invention described above with reference to a preferred embodiment of the present invention, those skilled in the art or those skilled in the art having ordinary knowledge in the scope of the invention described in the claims to be described later It will be understood that various modifications and variations can be made in the present invention without departing from the scope of the present invention.

Claims (11)

In order to inspect a display device including pixels for displaying an image and sensing elements disposed between the pixels and outputting a sensing signal by an external stimulus, the external stimulus may be individually applied to the sensing elements. External stimulus applying means for applying; And And a processing unit for detecting whether the respective sensing elements are defective by detecting the sensing signals output from the respective sensing elements by the external stimulus. 2. The inspection apparatus of claim 1, wherein the external stimulus is light, and the external stimulus applying means is a light supply device for applying the light corresponding to the position of each sensing element. The inspection apparatus of claim 2, wherein the light supply device sequentially applies light to the sensing elements. The display device according to claim 2, wherein the light supply device is a light generating device selected from the group consisting of a liquid crystal device, an organic electroluminescent device, a plasma display device, and a CRT device for applying the light to the sensing elements. Inspection device of the device. The inspection apparatus of claim 2, wherein the light supply device comprises a light emitting diode array substrate including a light emitting diode to supply the light to a position corresponding to each sensing element. The inspection apparatus of claim 2, wherein the light is a laser beam, and the light supply device is a laser beam scanning device that scans the laser beam to each sensing element. The data storage unit of claim 1, wherein the processing unit stores the position data of the sensing element to which the external stimulus is applied and whether or not the sensing element to which the external stimulus is applied is defective, the position data and the defect data. And an arithmetic module for determining a failure of the sensing element by using a light emitting device. The inspection apparatus of claim 1, wherein a display unit for displaying whether the sensing elements are defective is connected to the processing unit. In order to inspect a display device including pixels for displaying an image and sensing elements disposed between the pixels and outputting a sensing signal by an external stimulus, the external stimulus may be individually applied to the sensing elements. Applying; And And detecting whether the sensing elements are defective by detecting the sensing signals output from the sensing elements by the external stimulus. The method of claim 9, wherein applying the external stimulus sequentially applies light to the sensing element. The method of claim 9, wherein the applying of the external stimulus comprises sequentially applying a laser beam to the sensing element.