Illumination systems for eyeglass and facemask display systems

• US 6,724,354 B1
• Filed: 05/30/2000
• Issued: 04/20/2004
• Est. Priority Date: 06/21/1999
• Status: Expired due to Term

• Current Assignee: Google LLC (Alphabet Inc.)
• Original Assignee: MicroOptical Corporation
• Inventors: Spitzer, Mark B., Crawford, John O.
• Primary Examiner(s): Saras, Steven
• Assistant Examiner(s): Jorgensen, Leland R.
• Application Number:
  US09/580,138
• Time in Patent Office: 1,421 Days
• Field of Search: 345/8, 345/9, 345/102, 345/7, 345/87, 345/88, 345/89, 345/90-99, 345/100, 345/101, 345/103, 345/104, 345/32, 348/51, 348/52, 348/53, 348/54, 348/55, 348/56, 348/57, 348/58, 348/59, 348/60, 349/11, 349/61, 349/62, 349/63, 359/385
• US Class Current: 345/32
• CPC Class Codes: G02B 27/017 Head mounted
• CPC Class Codes: G02B 27/0172 characterised by optical features
• CPC Class Codes: G02B 27/1066 for enhancing image performance, like resolution, pixel numbers, dual magnifications or dynamic range, by tiling, slicing or overlapping fields of view
• CPC Class Codes: G02B 27/283 used for beam splitting or combining
• CPC Class Codes: G09G 2310/0235 Field-sequential colour display
• CPC Class Codes: G09G 2320/064 by time modulation of the brightness of the illumination source
• CPC Class Codes: G09G 3/3413 Details of control of colour illumination sources

Abstract

A display illumination and viewing system has an illumination optical path and a viewing optical path coinciding along a portion of their lengths. A display is located at one end of the coinciding path portion. A first lens system is located on the coinciding path portion and a second lens system is located on the viewing optical path. An illumination assembly is located on the illumination optical path and off the coinciding path portion. The illumination assembly is spaced from the first lens system by a distance corresponding to a focal length of the first lens system. A reflective and transmissive element is located at an opposite end of the coinciding path portion to reflect light from the illumination assembly onto the coinciding path portion toward the display and to transmit light from the display along the viewing optical path. In another aspect of the invention, the image display system is operable in a color mode and a monochrome mode. Illumination circuitry is in communication with an illumination source and includes a switch operative to switch the illumination source between the color mode to provide a color display and the monochrome mode to provide a monochrome display.

Claims

1. A display illumination and viewing system comprising:

an illumination optical path and a viewing optical path, at least a portion of the illumination optical path coinciding with at least a portion of the viewing optical path to form a coinciding path portion;

a display comprising an active matrix liquid crystal display located at one end of the coinciding path portion;

a first lens system located on the coinciding path portion and having a first focal length, the first lens system providing an image plane on the viewing optical path;

a second lens system located on the viewing optical path;

an illumination assembly located on the illumination optical path and off the coinciding path portion, the illumination assembly spaced from the first lens system by a same length as the first focal length of the first lens system; and

a reflective and transmissive element located at an opposite end of the coinciding path portion to reflect light from the illumination assembly onto the coinciding path portion toward the display and to transmit light from the display along the viewing optical path.

2. The display illumination and viewing system of claim 1, wherein the illumination assembly comprises red, green, and blue light emitting diodes.

3. The display illumination and viewing system of claim 1, wherein the illumination assembly comprises red, green, and blue laser diodes.

4. The display illumination and viewing system of claim 1, further comprising a further optical element on the illumination optical path.

5. The display illumination and viewing system of claim 4, wherein the further optical element comprises a diffuser.

6. The display illumination and viewing system of claim 1, wherein the reflective and transmissive element comprises a beam splitter.

7. The display illumination and viewing system of claim 6, wherein the beam splitter comprises a polarization beam splitter.

8. The display illumination and viewing system of claim 6, wherein the beam splitter comprises thin film multilayers or a thin film metal layer or a half silvered mirror or a beam splitting cube.

9. The display illumination and viewing system of claim 1, further comprising a housing, the display, the first lens system, the illumination assembly, and the reflective and transmissive element supported within the housing.

10. An eyewear assembly comprising:

a head-mountable frame;

an eyewear lens supported by the frame in front of a user'"'"'s eye; and

the display illumination and viewing system of claim 1 disposed to transmit light along the viewing optical path into an optical path through the lens.

11. The eyewear assembly of claim 10, further comprising a housing supported on the head-mountable frame, the display, the first lens system, the illumination assembly, and the reflective and transmissive element supported by the housing;

and

wherein the second lens system is affixed to the eyewear lens.