Scanned display with plurality of scanning assemblies

• US 6,433,907 B1
• Filed: 08/05/1999
• Issued: 08/13/2002
• Est. Priority Date: 08/05/1999
• Status: Expired due to Fees

• Current Assignee: Microvision, Inc.
• Original Assignee: Microvision, Inc.
• Inventors: Tegreene, Clarence T., Lippert, Thomas M.
• Primary Examiner(s): Spyrou, Cassandra
• Assistant Examiner(s): Amari, Alessandro V.
• Application Number:
  US09/369,672
• Time in Patent Office: 1,104 Days
• Field of Search: 359/201, 359/204, 359/223, 359/224, 348/756, 348/757
• US Class Current: 359/201.1
• CPC Class Codes: G02B 26/08 for controlling the direction of light in light guides G02B6/35

Abstract

A display apparatus includes a scanning assembly that scans about two or more axes, typically in a raster pattern. A plurality of light sources emit light from spaced apart locations toward the scanning assembly such that the scanning assembly simultaneously scans more than one of the beams. The scanning assembly includes a plurality of mirrors that sweep their respective beams through respective regions of an image field. The regions are immediately adjacent so that an overall image is produced by “tiling” of the regions. Because sweeps of the scanning assembly scan a plurality of tiles simultaneously the resolution and/or field of view of a display for a given scan angle and mirror size is increased relative to a single mirror sweeping a single beam. In alternative embodiments, tiling is used for imaging. Also, various approaches to controlling the frequency responses of the various scanners are described, including active control of MEMs scanners and passive frequency tuning.

Claims

1. A display device responsive to an image signal to produce a displayed image having first and second portions in respective first and second immediately adjacent image fields, comprising:

a first light source responsive to a first input signal to emit a first beam of modulated light along a first optical path;

a first scanning assembly positioned to receive the first beam of light and configured to scan the first beam of light into the first image field;

a second light source responsive to a second input signal to emit a second beam of modulated light along a second optical path;

a second scanning assembly different from the first scanning assembly, the second scanning assembly being positioned to receive the second beam of light and configured to scan the second beam of light into the second image field; and

an electronic controller having a signal input that receives the image signal, the electronic controller being responsive to the image signal to produce the first and second input signals;

wherein the first and second scanning assemblies each include a plurality of separate scanners.

2. The display device of claim 1 wherein each of the scanners in each plurality of scanners is a MEMs scanner.

3. A display device responsive to an image signal to produce a displayed image having first and second portions in respective first and second immediately adjacent image fields, comprising:

a first light source responsive to a first input signal to emit a first beam of modulated light along a first optical path;

a first scanning assembly positioned to receive the first beam of light and configured to scan the first beam of light into the first image field;

a second light source responsive to a second input signal to emit a second beam of modulated light along a second optical path;

a second scanning assembly different from the first scanning assembly, the second scanning assembly being positioned to receive the second beam of light and configured to scan the second beam of light into the second image field; and

an electronic controller having a signal input that receives the image signal, the electronic controller being responsive to the image signal to produce the first and second input signals;

wherein the first and second scanning assemblies each include a respective biaxial scanner.

4. A display device responsive to an image signal to produce a displayed image having first and second portions in respective first and second immediately adjacent image fields, comprising:

a first light source responsive to a first input signal to emit a first beam of modulated light along a first optical path;

a first scanning assembly positioned to receive the first beam of light and configured to scan the first beam of light into the first image field;

a second light source responsive to a second input signal to emit a second beam of modulated light along a second optical path;

a second scanning assembly different from the first scanning assembly, the second scanning assembly being positioned to receive the second beam of light and configured to scan the second beam of light into the second image field;

an electronic controller having a signal input that receives the image signal, the electronic controller being responsive to the image signal to produce the first and second input signals; and

a position sensor having a sensing input coupled to the first mirror and a sensing output coupled to the electronic controller, the position sensor being responsive to movement of the first mirror to produce an electrical signal at the sensing output corresponding to the position of the first mirror.

5. The display device of claim 4 wherein the first scanning assembly includes a first resonant device having a first resonant frequency and the second scanning assembly includes a second resonant device having a second resonant frequency.

6. The display device of claim 5 wherein the first and second resonant frequencies are substantially identical.