Infrared touch panel
US4868912A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 28, 1988 |
| Grant date | Sep 19, 1989 |
| Priority date | — |
| Expiry date | Jul 28, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F3/0421
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A touch panel system having enhanced touch detection which distinguishes between deliberate actuations of the touch system and accidental and other false actuations. The system has a display surface surrounded by a multiplicity of light emitting elements and light receiving elements that define a grid of intersecting light paths. The display surface is scanned by sequentially enabling selected pairs of the light emitting and light receiving elements. False actuation rejection involves the use of one or more of three techniques: ignoring touches which fail to block a minimum number of contiguous beams in both axes, ignoring touches which block in excess of a specified maximum number of contiguous beams in either axis, and ignoring touches which are of a duration of less than a minimum specified time. The minimum and maximum size constraints on the size of the object touching the screen, and the minimum contact time are programmable. These criteria enable the system to distinguish many types of false hits or accidental touchings of the screen from deliberate touchings by a person selecting an item on the touch panel. An additional feature of the present invention is beam fault tolera…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.