Low vibration resonant scanning unit for miniature optical display apparatus
US5009473A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 13, 1989 |
| Grant date | Apr 23, 1991 |
| Priority date | — |
| Expiry date | Nov 13, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06K7/10653
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A resonant scanning unit utilizes a "tuning fork" design with a mirror mounted on one arm of the tuning fork and a counterbalance mass mounted on the other arm. A voice coil electromagnetic motor mounted between the arms causes the arms to move in opposite directions. Light generated by a line of LEDs is reflected from the oscillating mirror to generate a raster display. Reaction forces generated by the motions of the mirror and counterbalance mass cancel at the device base, reducing vibration. In addition, the inventive structure allows placement of the mirror pivot point away from the center of the mirror which allows display devices constructed with the structure to be reduced in size. A second embodiment is disclosed in which molded construction reduces assembly cost and time and allows precise tuning of the reaction forces.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.