Registers – Coded record sensors – Particular sensor structure
Reexamination Certificate
2002-11-22
2004-08-03
Lee, Diane I. (Department: 2876)
Registers
Coded record sensors
Particular sensor structure
C235S454000, C235S462360, C310S309000
Reexamination Certificate
active
06769616
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to micro-electro-mechanical systems (MEMS), and more particularly to MEMS scanning mirrors.
DESCRIPTION OF RELATED ART
Various electrostatic designs for MEMS scanning mirrors have been proposed. Their applications include barcode readers, laser printers, confocal microscopes, fiber-optical network components, projection displays for projectors, rear projection TVs, wearable displays, and military laser tracking and guidance systems. Typically a MEMS scanning mirror is driven at its. main resonance to achieve a high scan angle. Invariably the manufacturing processes produce MEMS scanning mirrors with dimensional inconsistencies that vary the natural frequencies of the individual devices. If the main natural frequency of a minority of the MEMS scanning mirrors is too low or too high, the minority devices will not produce the proper scan speed and the proper scan angle under an alternating current (AC) drive voltage selected for a majority of the MEMS scanning mirrors. Thus, an apparatus and a method are needed to tune the main natural frequency of the MEMS scanning mirrors to improve the manufacturing yield of these devices.
SUMMARY OF THE INVENTION
In one embodiment of the invention, a MEMS structure includes a first electrode, a second electrode, and a mobile element. The first electrode is coupled to a first voltage source. The second electrode is coupled to a second voltage source. The mobile element includes a third electrode coupled to a third voltage source (e.g., an electrical ground). A steady voltage difference between the first electrode and the third electrode is used to tune the natural frequency of the structure to a scanning frequency of an application. An oscillating voltage difference between the second electrode and the third electrode at the scanning frequency of the application is used to oscillate the mobile element. In one embodiment, the mobile element is a mirror.
REFERENCES:
patent: 5963367 (1999-10-01), Aksyuk et al.
patent: 6088145 (2000-07-01), Dickensheets et al.
patent: 6155490 (2000-12-01), Ackley
patent: 6535318 (2003-03-01), Wood et al.
patent: 6612029 (2003-09-01), Behin et al.
US patent application Publlication No. US 2002/0158548 A1, Publication Date: Oct. 31, 2002.
D. Kee et al., “High-Resolution, High-Speed Microscanner In Single-Crystalline Silicon Actuated By Self-Aligned Dual-Mode Vertical Electrostatic Combdrive With Capability For Phased Array Operation”, Transducers '03, the 12thInternational Conference on Solid State Sensors, Actuators and Microsystems, Boston, Jun. 8-12, 2003, pp. 576-579.
Robert A. Conant et al., “A Flat High-Frequency Scanning Micromirror”, Berkeley Sensor & Actuator Center, University of California, Berkeley, Berkeley, CA, 4 pages.
Harald Schenk et al., Large Deflection Micromechanical Scanning Mirrors for Linear Scans and Pattern Generation, IEEE Journal of Selected Topics in Quantum Electronics, vol. 6, No. 5, Sep./Oct. 2000, pp 715-721.
Pamela R. Patterson et al., “A Scanning Micromirror With angular Comb Drive Actuation”, Electrical engineering Department, University of California at Los Angeles, Los Angeles, CA; Institute of Industrial Science, University of Tokyo, Tokyo, Japan, pp 544-547.
Meng-Hsiung Kiang et al., “Micromachined Polysilicon Microscanners for Barcod Readers”, IEEE Photonics Technology Letters, vol. 8, No. 12, Dec. 1996, pp 1707-1709.
Osamu Tsuboi et al., “A Rotational Comb-Driven Micromirror With A Large deflection Angle And Low Drive Voltage”, Fujitsu Laboratories Ltd., pp 532-535.
Hiroshi Miyajima et al., “Product Development Of A Mems Optical Scanner For A Laser Scanning Microscope”, Olympus Optical Co., Ltd., Tokyo Japan pp 552-555.
Jin-Ho Lee et al., “Design And Fabrication of Scanning Mirror For Laser Display”, 2002 Elsevier Science B.V., pp 223-230.
Clark T.-C Nguyen, “Frequency-Selective MEMS for Miniaturized Communications Devices”, 1998 IEEE, Department of Electrical Engineering and Computer Science University of Michigan, pp 445-460.
Faiz Sherman et al., “In-Plane Microactuator For fluid Control Application”, Electrical Engineering Department University of California, Los Angeles, 6 pages.
Fu Yee-Chung
Kuo Ting-Tung
Advanced Nano Systems
Hsia David C.
Lee Diane I.
Lee Seung H
Patent Law Group LLP
LandOfFree
Bidirectional MEMS scanning mirror with tunable natural... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Bidirectional MEMS scanning mirror with tunable natural..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Bidirectional MEMS scanning mirror with tunable natural... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3320235