Frequency tunable resonant scanner with auxiliary arms
US6654158B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 1, 2002 |
| Grant date | Nov 25, 2003 |
| Priority date | — |
| Expiry date | Nov 27, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B26/0841
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A MEMs scanning device has a variable resonant frequency. In one embodiment, the MEMs device includes a flexible arm that extends from an oscillatory body. An electrical field applies a force to the flexible arm, thereby bending the flexible arm to change the moment of inertia of the oscillatory body and a secondary mass carried by the flexible arm. The shifted combined center of mass changes the resonant frequency of the MEMs device. In another embodiment, an absorptive material forms a portion of a torsional arm that supports the oscillatory body. The mechanical properties of the absorptive material can be varied by varying the concentration of a gas surrounding the absorptive material. The varied mechanical properties change the resonant frequency of the scanning device. A display apparatus includes the scanning device and the scanning device scans about two or more axes, typically in a raster pattern. Various approaches to controlling the frequency responses of the scanning device are described, including active control of MEMs scanners and passive frequency tuning.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.