Cursor apparatus for interactive graphic display system
US4354102A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 13, 1980 |
| Grant date | Oct 12, 1982 |
| Priority date | — |
| Expiry date | Nov 13, 2000 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F3/038
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Graphic data entry in an interactive graphic display system is achieved by means of an apparatus that provides automatic centering of a pointing laser beam on a hand held cursor. The graphic display system provides a means for displaying and comparing through superposition full size overlaid graphical data and projected graphical data on a common display screen. It includes a steerable pointing laser the beam of which scans the display screen in response to a laser beam deflection circuit. The system also includes laser beam position sensing and indicating circuits which accurately measure the laser beam position. Centering of the laser beam on the cursor at the display screen is accomplished by dithering the beam uniformly about its average position in a discrete dither pattern and utilizing the dither pattern to determine misalignment of the beam's average position with respect to the center of the cursor. The cursor includes photo detector elements that are geometrically configured to conform to the dither pattern so that signals derived from an eccentric relationship of the beam dither pattern and the photo detector element configuration can be processed to provide beam misalig…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.