Active matrix display circuit substrate, display panel including the same, inspection method thereof, and inspection device thereof

• US 20060267625A1
• Filed: 01/28/2004
• Published: 11/30/2006
• Est. Priority Date: 02/07/2003
• Status: Abandoned Application

• Current Assignee: Agilent Technologies, Inc.
• Original Assignee: Agilent Technologies, Inc.
• Inventors: Kaneko, Yasuhisa
• Application Number:
  US10/543,229
• Publication Number:
  US 20060267625A1
• Time in Patent Office: Days
• US Class Current: 324/760.20
• CPC Class Codes: G02F 1/1362 Active matrix addressed cells G02F1/134336, G02F1/134363 take precedence
• CPC Class Codes: G02F 1/136254 Checking; Testing
• CPC Class Codes: G09G 3/006 Electronic inspection or testing of displays and display drivers, e.g. of LED or LCD displays testing individual LED's G01R31/2635; testing lamps G01R31/44; testing of optical features of LCD displays G02F1/1309
• CPC Class Codes: G09G 3/3225 using an active matrix

Abstract

An abstract matrix circuit substrate for liquid crystal or EL display having a drive circuit for each of the pixels. In the proximity of each drive circuit, there is provided an optical control switch for performing control so that a current path between the drive circuit and an external wiring is provided when the ON state is set in. During inspection, light is applied to a predetermined optical control switch so as to turn ON the optical control switch and evaluation is performed by measuring the current passing through the optical control switch.

Claims

1. An active matrix display circuit substrate, wherein the optical control switches for providing control such that a current path is provided between drive circuits corresponding to each pixel and external wiring when the display is ON are disposed near each drive circuit on an active-matrix display circuit substrate for liquid crystal or EL displays having drive circuits corresponding to each pixel.

2. The active-matrix display circuit substrate according to claim 1, wherein said optical control switches are connected in-series to the active elements in the drive circuits and a drive circuit at a predetermined position is actuated and the corresponding optical control switch is turned on by light from the outside so that the drive current can pass through the optical control switch and the current passing through the switch can be measured in order to check the operation of predetermined active elements in the drive circuit.

3. The active-matrix display circuit substrate according to claim 1, wherein said active-matrix display circuit substrate is a substrate for EL displays and the optical control switches are used as detection elements for directly detecting light from EL emission elements disposed on the active-matrix display circuit substrate.

4. The active-matrix display circuit substrate according to claim 1, wherein said active-matrix display circuit substrate is a substrate for EL displays and the optical control switches are used as detection elements for detecting reflected light by allowing light from the EL emission elements disposed on the active-matrix display circuit substrate to be reflected by an external object.

5. The active-matrix display circuit substrate according to claim 1, wherein said optical control switches in the active-matrix display circuit substrate are used as detection elements for detecting the emission of light from an external pointing apparatus.

6. The active-matrix display circuit substrate according to claim 2, wherein said optical control switches are made such that their output is applied to any wiring disposed in a drive circuit corresponding to another pixel unit adjacent to the pixel unit to which the optical control switch in question is assigned.

7. The active-matrix display circuit substrate according to claim 2, wherein said optical control switches are made such that their output is applied to the gate line in the drive circuit corresponding to another pixel unit adjacent to the pixel unit to which the optical control switching in question is assigned.

8. The active-matrix display circuit substrate according to claim 1, wherein said optical control switches are made such that their output is applied to wiring added to the drive circuit.

9. The active-matrix display circuit substrate according to claim 1, wherein said optical control switches are photoconductive switches.

10. The active-matrix display circuit substrate according to claim 1, wherein said optical control switches are made such that resistance is applied in-series.

11. The active-matrix display circuit substrate according to claim 1, wherein said optical control switches comprise a semiconductor layer, the base of which is the same semiconductor material as the drive circuit.

12. The active-matrix display circuit substrate according to claim 11, wherein said semiconductor material is amorphous silicon or polycrystalline silicon.

13. A display panel which comprises:

an active matrix display circuit substrate, wherein the optical control switches for providing control such that a current path is provided between drive circuits corresponding to each pixel and external wiring when the display is ON are disposed near each drive circuit on an active-matrix display circuit substrate for liquid crystal or EL displays having drive circuits corresponding to each pixel; and

an EL material layer disposed on the circuit substrate.

14. A method for inspecting the operation of a pixel drive circuit disposed on an active-matrix display circuit substrate for liquid crystal or EL displays, said method comprising:

providing current to drive circuits corresponding to each pixel unit of the circuit substrate prior to injection of liquid crystals or application of an EL material, with this current being large enough to confirm the operation of a predetermined active element in a drive circuit;

exposing to light an optical control switch connected to a predetermined position on the drive circuit and turning on the optical control switch; and

measuring the current passing through the optical control switch when the optical control switch has been turned on.

15. The method according claim 14, wherein the step for applying current to the drive circuit, the step for exposing the optical control switch to light, and the step for measuring current are performed in succession on the drive circuit such that the light scans the circuit substrate.

16. The method according to claim 14, wherein the light is converged light that is to be irradiated onto an optical control switch corresponding to one pixel unit only.

17. The method according to claim 14, wherein the light is irradiated onto optical control switches of the drive circuits corresponding to a plurality of pixel units in one row or a plurality of rows corresponding to pixel units in matrix form.

18. The method according to claim 14, wherein the light irradiation time is set such that a charge can pass through the active elements, with this charge being large enough to confirm that the active elements are driven via exposure to light within a unit of time.

19. An apparatus for inspecting an active-matrix display circuit substrate for a liquid crystal or EL display, said apparatus comprising:

a support member for supporting the active matrix display circuit substrate before liquid crystals are injected or an EL material is applied;

a power source for applying a current to each pixel drive circuit on the display circuit substrate, with this current being large enough to confirm the operation of pre-determined active elements in a pixel drive circuit;

a light source for exposing to light optical control switches obtained by connection to each pixel drive circuit on the display circuit substrate; and

a measurement means for measuring the electrical properties when the optical control switches have been exposed to light and turned on.

20. The inspection apparatus according to claim 19, wherein said light source is a laser light source.

21. The inspection device according to claim 19, wherein said measurement means is made such that the current flowing through the optical control switches is measured.