Liquid crystal diplay device

• US 20030189536A1
• Filed: 03/08/2001
• Published: 10/09/2003
• Est. Priority Date: 03/14/2000
• Status: Active Grant

• Current Assignee: TPO Hong Kong Holding Limited (InnoLux Corporation)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Ruigt, Adolphe Johannes Gerardus
• Granted Patent: US 6,894,672 B2
• Time in Patent Office: Days
• US Class Current: 345/87
• CPC Class Codes: G09G 2320/029 by monitoring one or more pixels in the display panel, e.g. by monitoring a fixed reference pixel
• CPC Class Codes: G09G 2320/041 Temperature compensation
• CPC Class Codes: G09G 3/3622 using a passive matrix G09G3/3674 - G09G3/3696 take precedence

Abstract

Compensation, e.g. temperature compensation of the operating voltage of an LCD is obtained by using the V₅₀ point of a test cell via the differentiated AC current (switching current of the test cell as a control parameter).

Claims

1. A liquid crystal display device comprising a first substrate provided with electrodes and a second substrate provided with electrodes, and a twisted nematic liquid crystal material between the two substrates, in which, viewed perpendicularly to the substrates, overlapping parts of the electrodes define pixels, characterized in that the display device is provided with means for adjusting the operating voltage of the liquid crystal display device in dependence upon the switching behavior of a measuring element.

2. A liquid crystal display device as claimed in claim 1, characterized in that the means for adjusting the operating voltage of the display device comprise means for measuring the switching current of the measuring element.

3. A liquid crystal display device as claimed in claim 2, characterized in that the means for adjusting the operating voltage of the display device comprise means for raising the operating voltage and simultaneously measuring the switching current in the measuring element.

4. A liquid crystal display device as claimed in claim 2, characterized in that the means for adjusting the operating voltage of the display device comprise means for raising the operating voltage and measuring the peak current in the measuring element.

5. A liquid crystal display device as claimed in claim 1, characterized in that the means for adjusting the operating voltage of the display device comprise means for measuring the capacitance of the measuring element.

6. A liquid crystal display device as claimed in claim 1, characterized in that the measuring element comprises a pixel.