Electronic light pen system
US6377249B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Nov 9, 1998 |
| Grant date | Apr 23, 2002 |
| Priority date | — |
| Expiry date | Nov 9, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F3/03542
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
An electronic light pen used in conjunction with a video display permits the position of the light pen to be determined with respect to the video display by the particular color or grey scale value of light emitted by the video display and received by the electronic light pen. The light from the video display is separated into three primary colors for a color display, namely red, blue, and green, and separated into grey scale shades for a monochrome display. Positional information of the light pen is calculated based on the relation of the color measured to the color previously programmed and presently displayed on that area of the screen, at any instant in time. The light pen has a focusing system that focuses light from the display to its optical detectors. The optical detectors have red, green, and blue filters to determine the brightness of each color. A grey scale value may be determined if the display is monochrome. An optional telephoto lens attachment allows the light pen to be aimed at displays from a distance, or to be used with projection displays. A display can be written with color information to preprogrammed locations on the screen. The colors at each area of the dis…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.