Patent · US Expired

Liquid crystal display integrated with hall effect pointing device

US5389951A · kind A · utility

54Cited by
3References
13Claims
0Family size

Assignee

Inventor

Key dates

Filing dateJul 21, 1993
Grant dateFeb 14, 1995
Priority date
Expiry dateJul 21, 2013

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG02F1/1368
  • WIPO fieldComputer technology
  • WIPO sectorElectrical engineering

Abstract

A liquid crystal display (LCD) is constructed in layers including an integrated circuit layer containing thin film transistors (TFTs) for controlling activation of individual liquid crystal cells, and selectively actuatable Hall effect elements (HEEs) for controlling operation of the TFTs. The display operates in different modes including operating solely as an output device, or as an input device, or both. Each HEE and TFT is contained in a cell circuit that further includes a switch operable in a plurality of modes in accordance with the settings of mode control signals and cell selection signals. A magnetic actuator produces a magnetic field for selectively actuating cells. Cell circuits produce output signals dependent on the polarity of the actuating magnetic field. An alternate cell circuit allows a cell to be actuated by a field of one polarity and deactuated by a second field of the opposite polarity.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.