Optical scanning system with correction

• US 7,098,871 B1
• Filed: 09/20/1999
• Issued: 08/29/2006
• Est. Priority Date: 08/05/1998
• Status: Expired due to Term

• Current Assignee: Microvision, Inc., Montana State University, The Research and Development Institute At Montana State University
• Original Assignee: Microvision, Inc.
• Inventors: Tegreene, Clarence T., Dickensheets, David L.
• Primary Examiner(s): Hjerpe, Richard
• Assistant Examiner(s): Nguyen, Kevin M.
• Application Number:
  US09/400,350
• Time in Patent Office: 2,535 Days
• Field of Search: 345/7, 345/8, 345/166, 345/84, 345/85, 359/201, 359/199, 359/388, 359/385, 359/334, 359/368, 359/560, 359/230, 359/618, 359/202, 359/213, 359/291, 382/312, 382/313, 382/314, 358/475, 358/509, 358/480, 250/234, 250/235, 250/236, 250/201.5, 348/770, 348/771, 348/755, 348/756, 348/764, 348/768
• US Class Current: 345/7
• CPC Class Codes: G02B 2027/011 comprising device for correcting geometrical aberrations, distortion
• CPC Class Codes: G02B 2027/014 comprising information/image processing systems
• CPC Class Codes: G02B 26/10 Scanning systems
• CPC Class Codes: G02B 26/101 with both horizontal and vertical deflecting means, e.g. raster or XY scanners colour television using laser beams scanning a display screen H04N9/3129
• CPC Class Codes: G02B 27/0031 for scanning purposes
• CPC Class Codes: G02B 27/01 Head-up displays
• CPC Class Codes: G02B 27/0101 characterised by optical features G02B27/0172 takes precedence
• CPC Class Codes: G09G 3/02 by tracing or scanning a light beam on a screen
• CPC Class Codes: H04N 1/047 Detection, control or error compensation of scanning velocity or position H04N1/0402 and H04N1/17 take precedence
• CPC Class Codes: H04N 2201/0471 using dedicated detectors
• CPC Class Codes: H04N 2201/04744 by detecting the scanned beam or a reference beam
• CPC Class Codes: H04N 2201/0476 using an optical, electro-optical or acousto-optical element

Abstract

A scanning system device has a predetermined aberration as it scans or switches light along selected optical paths. A deformable membrane receives the light and introduces an inverse “aberration” that offsets that of the scanning system. In one embodiment the scanning system includes a torsion arm that supports an oscillatory body. The torsion arm and/or body can be machined from metal, micromachined in silicon or formed in a variety of other ways. Alternatively, the scanning system may include a rotating polygonal scanner or other type of optical scanner. In another approach, an optical switch replaces the scanner.

Claims

1. A scanning apparatus, comprising:

a primary mirror that moves through a predetermined scan path at a selected scan rate having a scanning period that defines a scanning frequency; and

a resonant reflector aligned to the primary mirror and being of the type that moves resonantly through a movement path at a resonant frequency, wherein the resonant frequency is an integral multiple of the scanning frequency; and

wherein the resonant reflector comprises a deformable microelectromechanical (MEMS) reflective membrane aligned to reflect light reflected from the primary mirror and wherein the movement path includes deformation of the membrane.