LCD having temperature detection elements provided on an active-substrate

• US 6,414,740 B1
• Filed: 05/31/2000
• Issued: 07/02/2002
• Est. Priority Date: 06/01/1999
• Status: Expired due to Term

• Current Assignee: Vista Peak Ventures LLC (Dominion Harbor Enterprises, LLC)
• Original Assignee: NEC Corporation
• Inventors: Hosoyamada, Shunichi
• Primary Examiner(s): Ton, Toan
• Application Number:
  US09/583,730
• Time in Patent Office: 762 Days
• Field of Search: 349/161, 349/20, 349/21, 349/22
• US Class Current: 349/161
• CPC Class Codes: G02F 1/133382 Heating or cooling of liquid crystal cells other than for activation, e.g. circuits or arrangements for temperature control, stabilisation or uniform distribution over the cell
• CPC Class Codes: G02F 1/133388 with constructional differences between the display region and the peripheral region
• CPC Class Codes: G09G 2320/041 Temperature compensation
• CPC Class Codes: G09G 3/3648 using an active matrix G09G3/367 - G09G3/3696 take precedence

Abstract

In a black mask light blocking region within a liquid-crystal display panel formed by a TFT substrate, a color filter substrate, and a liquid-crystal layer disposed in a space between the TFT substrate and the color filter substrate, a temperature detection element is formed, simultaneously with process step that forms a switching element such as a thin-film transistor on the TFT substrate, thereby enabling detection of the temperature of the liquid-crystal layer without the influence of outside air or the like.

Claims

1. A liquid crystal display comprising:

a first substrate having formed on a first surface thereof a plurality of scanning lines and a plurality of signal lines disposed perpendicularly to the scanning lines, and a plurality of pixel electrodes respectively associated with intersections of said scanning lines and signal lines and connected to said signal lines by respective switching elements;

a second substrate opposed to the first surface of the first substrate;

a liquid crystal disposed between the first substrate and the second substrate;

a plurality of temperature detection elements provided on the first surface of the first substrate within a light blocking region at an outer periphery of a display region of the liquid crystal display; and

a scanning line driving circuit and a signal line driving circuit, each providing drive voltages to the scanning lines and the signal lines, respectively, in accordance with signals from the plurality of temperature detection elements.

2. The liquid crystal display claimed in claim 1, wherein the scanning line driving circuit and signal line driving circuit provide respective driving voltages in accordance with an average of outputs of the temperature detection elements.

3. The liquid crystal display claimed in claim 1, wherein the scanning line driving circuit and signal line driving circuit provide respective driving voltages in accordance with a selected one of outputs of the temperature detection elements.

4. The liquid crystal display claimed in claim 1, wherein the scanning line driving circuit and signal line driving circuit provide respective driving voltages in accordance with a range within which more than one of outputs of the temperature detection elements occurs.

5. The liquid crystal display claimed in claim 1, further comprising:

a temperature detection circuit coupled to said plurality of temperature detection elements; and

a temperature control circuit receiving an output signal of the temperature detection circuit and providing output signals to the scanning line driving circuit and signal line driving circuit for setting respective drive voltages thereof.

6. The liquid crystal display claimed in claim 1, wherein the switching elements comprise thin film transistors, and wherein the temperature detection elements comprise thin film transistors.

7. The liquid crystal display claimed in claim 1, wherein the switching elements comprise thin film transistors, and wherein the temperature detection elements comprise one of thin film diodes and thin film constant voltage diodes.

8. The liquid crystal display claimed in claim 1, wherein a semiconductor layer of the switching elements and a semiconductor layer of the temperature detection elements comprise amorphous silicon.

9. The liquid crystal display claimed in claim 1 wherein the signal line driving circuit is provided on a tape carrier package and wherein output terminals of the temperature detection elements are coupled to wirings on the tape carrier package.