LCD touch screen
US5105186A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 25, 1990 |
| Grant date | Apr 14, 1992 |
| Priority date | — |
| Expiry date | May 25, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02F1/13338
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A touch screen includes a liquid crystal display (LCD) having a viewing surface through which light passes into and out of the display and a back surface comprising a transflector such as transflective film. The transflector reflects some of the light back through the display and viewing surface and transmits some of the light. An array of light dependent resistors (LDRs) or equivalent light detecting devices underlie the transflector and detect a change in the transmitted light caused by a touching of the viewing surface. The light detecting array may be integrated into a keyboard interface. Keys are then displayed on the viewing surface opposite LDRs in the array to indicate where the viewing surface must be touched to actuate a key.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.