Display matrix substrate, production method of the same and display matrix circuit

• US 6,259,424 B1
• Filed: 03/03/1999
• Issued: 07/10/2001
• Est. Priority Date: 03/04/1998
• Status: Expired due to Fees

• Current Assignee: JVC Kenwood Corporation
• Original Assignee: Victor Company of Japan Limited (JVC Kenwood Corporation)
• Inventors: Kurogane, Hideo
• Primary Examiner(s): Shalwala, Bipin
• Assistant Examiner(s): Said, Mansour M.
• Application Number:
  US09/261,425
• Time in Patent Office: 860 Days
• Field of Search: 345/90, 345/92, 345/93, 345/94, 345/98, 345/99, 345/904, 345/87, 345/208, 345/205
• US Class Current: 345/93
• CPC Class Codes: G02F 1/13624 having more than one switching element per pixel
• CPC Class Codes: G02F 1/136268 Switch defects
• CPC Class Codes: G02F 1/1368 in which the switching element is a three-electrode device G02F1/136277 takes precedence
• CPC Class Codes: G09G 2330/08 Fault-tolerant or redundant circuits, or circuits in which repair of defects is prepared
• CPC Class Codes: G09G 3/3648 using an active matrix G09G3/367 - G09G3/3696 take precedence
• CPC Class Codes: Y10S 345/904 Display with fail/safe testing feature

Abstract

A display matrix substrate capable of minimizing an adverse effect of a defective switching element developed in the display matrix substrate. On a substrate 10 plural pixel electrodes 2A, 2B are formed in a matrix form. Switching elements 1A, 1B are provided corresponding to the respective plural pixel electrodes 2A, 2B. Voltage is applied to the pixel electrodes 2A, 2B to display an image on the display matrix substrate by successively operating the switching elements. Defective switching element 1A among the plural switching elements is preliminarily detected in a production process. A pixel electrode 2A of the defective switching element 1A is electrically connected to a pixel electrode 2B of a normal switching element 1B adjacent to the defective switching element 1A. Thereby, it is possible to minimize the adverse effect of the defective switching element 1A to a displayed image by making the pixel electrode of the defective switching element 1A operate together with the pixel electrode of the normal switching element 1B adjacent thereto.

Claims

1. A display matrix substrate used for displaying an image, the display matrix substrate comprising a substrate, a plurality of pixel electrodes arranged in a matrix form on the substrate, and a plurality of switching elements arranged corresponding to the plurality of pixel electrodes, wherein the image is displayed by successively driving the switching elements so as to apply voltages to the plurality of pixel electrodes, the display matrix substrate further comprising:

a first pixel electrode provided to a defective switching element preliminarily detected among the switching elements by driving the switching elements in a production process, the first pixel electrode electrically connected to a second pixel electrode provided to a normal switching element residing adjacent to the defective switching element in the production process.

2. A display matrix circuit for driving a display matrix substrate comprising a substrate, a plurality of pixel electrodes arranged in a matrix form on the substrate, and a plurality of switching elements arranged corresponding to the plurality of pixel electrodes, the plurality of pixel electrodes including a first pixel electrode provided to a defective switching element among the plurality of the switching elements and a second pixel electrode provided to a normal switching element residing adjacent to the defective switching element, the first pixel electrode being electrically connected to the second pixel electrode, wherein the image is displayed by successively driving the plurality of switching elements so as to apply voltages to the plurality of pixel electrodes, the display matrix circuit comprising:

defective-pixel memory means for storing positional information of the defective switching element;

temporary memory means for storing a first video signal intended to drive the defective switching element on a basis of the positional information stored in the defective-pixel memory means; and

signal conversion means for generating a second video signal to drive the normal switching element on a basis of a third video signal to be originally intended to drive the normal switching element and the first video signal read out from the temporary memory means when the normal switching element is driven.

3. A display matrix circuit for driving a display matrix substrate comprising a substrate, a plurality of pixel electrodes arranged in a matrix form on the substrate, and a plurality of switching elements arranged corresponding to the plurality of pixel electrodes, the plurality of pixel electrodes including a first pixel electrode provided to a defective switching element among the plurality of the switching elements and a second pixel electrode provided to a normal switching element residing adjacent to the defective switching element, the first pixel electrode being electrically connected to the second pixel electrode, wherein the image is displayed by successively driving the plurality of switching elements so as to apply voltages to the plurality of pixel electrodes, the display matrix circuit comprising:

defective-pixel memory means for storing positional information of the defective switching element;

temporary memory means for storing a first video signal intended to drive the defective switching element on a basis of the positional information stored in the defective-pixel memory means;

status judging means for judging a level state of video signals driving peripheral switching elements arranged adjacent to the defective switching element, and

signal conversion means for generating a second video signal to drive the normal switching element on a basis of a result obtained from the status judging means and of a third video signal originally intended to drive the normal switching element and of the first video signal read out from the temporary memory means when the normal switching element is driven.

4. A display matrix circuit as claimed in claim 3, wherein the second video signal is obtained by adding the first video signal to a the third video signal originally intended to drive the normal switching and dividing a sum of the first and third video signals by 2 when the result obtained from the status judging means indicates a neutral level.

5. A display matrix circuit as claimed in claim 3, wherein the first video signal read out from the temporary memory means is arranged to drive the normal switching element when a result from the status judging means indicates other levels than a neutral level.

6. A production method of a display matrix substrate used for displaying an image, the display matrix substrate comprising a substrate, a plurality of pixel electrodes arranged in a matrix form on the substrate, and a plurality of switching elements arranged corresponding to the plurality of pixel electrodes, wherein the image is displayed by successively driving the switching elements so as to apply voltages to the plurality pixel electrodes, the production method comprising the steps of:

a first process for forming the plurality of the switching elements on the substrate, wherein the plurality of switching elements contains at least a normal switching element and a defective switching element;

a second process for detecting the defective switching element prior to forming the plurality of pixel electrodes of the plurality of switching elements; and

a third process for electrically connecting a pixel electrode of the normal switching element to a pixel electrode of the defective switching element detected in the second process, wherein the normal switching element resides adjacent to the defective switching element.

7. A production method of a display matrix substrate as claimed in claim 6, wherein the third process further includes;

a fourth process for forming an insulation layer on the plurality of switching elements;

a fifth process for forming an opening on the insulation layer at a position corresponding to the normal switching element;

a sixth process for forming a thin layer of pixel electrode on the insulation layer, and

a seventh process for selectively etching the thin layer of pixel electrode so that the pixel electrode of the defective switching element is electrically connected to the pixel electrode of the normal switching element through the opening formed in the fifth process.