Miniature optical scanner for a two axis scanning system

• US 5,751,465 A
• Filed: 06/13/1996
• Issued: 05/12/1998
• Est. Priority Date: 10/26/1994
• Status: Expired due to Term

• Current Assignee: University of Washington
• Original Assignee: University of Washington
• Inventors: Furness, Thomas A. III, Melville, Charles D., Tidwell, Michael R.
• Primary Examiner(s): Phan, James
• Application Number:
  US08/664,103
• Time in Patent Office: 698 Days
• Field of Search: 359/196, 359/201, 359/202, 359/209, 359/212-215, 359/199, 347/225, 347/256-260
• US Class Current: 359/213.1
• 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 7/1821 for rotating or oscillating mirrors

Abstract

A miniature optical scanner includes an electromagnetic drive having stationary magnets and stationary drive coils to minimize the rotational inertia of the scanner and increase the scanner'"'"'s resonant frequency. The scanner is such that the resonant frequency is manually tunable as well as automatically adjustable to compensate for variables causing frequency drift. The optical scan angle is increased by employing a multiplying mirror with the optical scanner. For a two axis scanning system, the multiplying mirror may be formed of a second optical scanner to increase the optical scan angle relative to both of the axes.

Claims

1. An optical scanning system for scanning a light beam from a source of light comprising:

a multiplying mirror for reflecting a light beam;

a first optical scanning mirror for reflecting a light beam from said source, said first optical scanning mirror oscillating about an axis of rotation through a mechanical first scan angle to provide a first optical scan angle and said multiplying mirror being positioned relative to said first optical scanning mirror to reflect the reflected light beam from said first optical scanning mirror back onto said first optical scanning mirror such that the light beam is reflected by said first optical scanning mirror a multiple number of times before being output from the scanning system to cause said first optical scanning mirror to scan said light beam through an output scan angle that is greater than said first optical scan angle by a factor that is equal to said multiple number of times.

2. An optical scanning system as recited in claim 1 wherein said first optical scanning mirror and multiplying mirror are positioned relative to each other to form a retro-reflective scanning system.

3. An optical scanning system as recited in claim 1 wherein said first optical scanning mirror and multiplying mirror are positioned relative to each other to form a trans-reflective scanning system.

4. An optical scanning system as recited in claim 1 wherein said multiplying mirror is stationary.

5. An optical scanning system as recited in claim 1 wherein said multiplying mirror is a scanning mirror.

6. An optical scanning system as recited in claim 1 wherein said first optical scanning mirror scans light relative to a first axis and said multiplying mirror is a scanning mirror that scans said light relative to a second axis that is orthogonal to said first axis.

7. An optical scanning system as recited in claim 1 wherein said light beam is reflected off of said first optical scanning mirror a multiple number of times that is greater than two.