LCD temperature sensing
AssigneeTelefonaktiebolaget LM Ericsson (publ)
InventorSturla Lutnaes
Life of this patent
Estimating the term…
Abstract
The temperature of a liquid crystal display (LCD), for example provided in a mobile telephone, is measured by covering the LCD with a conductive touch screen bottom sheet having a known resistance-temperature relationship. A temperature-stable resistor is connected to the touch screen bottom sheet, and a voltage is applied across the resistor and the sheet. The voltage signal between the resistor and the touch screen bottom sheet is measured and converted to digital representation by an A/D-converter. The measured voltage signal is used to calculate the temperature of the touch screen bottom sheet, which is substantially equal to the temperature of the LCD.
Claims15
A device for measuring a temperature of a liquid crystal display (LCD), comprising:
- a touch screen applied to the LCD, the touch screen including a transparent bottom conductive layer arranged in a heat-conducting relationship with a top plate of the LCD to have substantially the same temperature distribution as the top plate of the LCD, an electrical conducting characteristic of the transparent bottom conductive layer thereby being dependent on a temperature of the top plate of the LCD;
- and
- means for measuring the electrical conducting characteristic of the transparent bottom conductive layer of the touch screen to determine a corresponding estimation of the temperature of the LCD.
A mobile telephone having a LCD and a device for measuring a temperature of the LCD, the device comprising:
- a touch screen applied to the LCD, the touch screen including a transparent bottom conductive layer arranged in a heat-conducting relationship with a top plate of the LCD to have substantially the same temperature distribution as the top plate of the LCD, an electrical conducting characteristic of the transparent bottom conductive layer thereby being dependent on a temperature of the top plate of the LCD;
- and
- means for measuring the electrical conducting characteristic of the transparent bottom conductive layer of the touch screen to determine a corresponding estimation of the temperature of the LCD.
A portable computer having a LCD and a device for measuring a temperature of the LCD, the device comprising:
- a touch screen applied to the LCD, the touch screen including a transparent bottom conductive layer arranged in a heat-conducting relationship with a top plate of the LCD to have substantially the same temperature distribution as the top plate of the LCD, an electrical conducting characteristic of the transparent bottom conductive layer thereby being dependent on a temperature of the top plate of the LCD;
- and
- means for measuring the electrical conducting characteristic of the transparent bottom conductive layer of the touch screen to determine a corresponding estimation of the temperature of the LCD.
Dependencies are inferred from the claim text.