Automatic alignment of cathode ray tube video displays in local magnetic fields
US6130505A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 8, 1997 |
| Grant date | Oct 10, 2000 |
| Priority date | — |
| Expiry date | Aug 8, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J9/44
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A system and method for dynamic adjustment of video images on a cathode ray tube in diverse geographic local magnetic fields. The present invention uses a CRT magnetometer that accurately senses differences in the strength and direction of a local magnetic field in three axes, i.e., the x, y, and z axes. The cathode ray tube includes a digital monitor board or monitor circuitry that has a processor and memory and is capable of retrieving correction factor data and magnetic correction data generated by a vision system. The digital monitor board receives CRT magnetometer signals and uses the signals with magnetic correction data to adjust the correction factor data to generate locale specific correction factor data for the sensed local magnetic field. The digital monitor board is capable of decoding the locale specific correction factor data using DACs, PDMs, PWMs, and interpolation engines to generate correction signals that are used to adjust the video image to correct for magnetically induced distortion.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.