Temperature sensor for liquid crystal display device
US7492344B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Aug 13, 2004 |
| Grant date | Feb 17, 2009 |
| Priority date | — |
| Expiry date | Mar 20, 2026 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG09G2320/041
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A temperature sensing apparatus for a liquid crystal display device is disclosed. The apparatus can measure the device temperature without the existence of a conventional PN junction. The temperature sensing apparatus comprises at least one thin-film transistor (TFT) cell, a variable current source, a buffer and a sensing circuit. Each TFT cell has its respective drain and gate coupled together and a source coupled to a ground. The variable current source is coupled to the drain of the TFT cell. The buffer has an input coupled to the drain of the TFT cell. The sensing circuit has an input coupled to an output of the buffer and an output to produce a voltage output signal. The temperature of the TFT cell is determined by inputting two currents at a sub-saturation region of the TFT cell and measuring voltage output signal difference.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.