Optical device containing a liquid crystal element for changing optical characteristics of a lens element

• US 5,815,233 A
• Filed: 10/14/1997
• Issued: 09/29/1998
• Est. Priority Date: 03/31/1993
• Status: Expired due to Term

• Current Assignee: Citizen Holdings Co., Ltd.
• Original Assignee: Citizen Watch Co Limited (Citizen Electronics Company Limited)
• Inventors: Takaki, Yasuhiro, Morokawa, Shigeru
• Primary Examiner(s): Sikes, William L.
• Assistant Examiner(s): NGUYEN, TIEP HUU
• Application Number:
  US08/949,815
• Time in Patent Office: 350 Days
• Field of Search: 359/39, 359/40, 359/41, 359/94, 349/200, 349/57
• US Class Current: 349/200
• CPC Class Codes: G02F 1/13 based on liquid crystals, e.g. single liquid crystal display cells
• CPC Class Codes: G02F 1/1393 the birefringence of the liquid crystal being electrically controlled, e.g. ECB-, DAP-, HAN-, PI-LC cells G02F1/1396, G02F1/141 take precedence
• CPC Class Codes: G02F 1/1396 the liquid crystal being selectively controlled between a twisted state and a non-twisted state, e.g. TN-LC cell G02F1/141 takes precedence
• CPC Class Codes: G02F 1/29 for the control of the position or the direction of light beams, i.e. deflection
• CPC Class Codes: G02F 1/294 Variable focal length devices
• CPC Class Codes: G02F 2203/28 focussing or defocussing
• CPC Class Codes: G02F 2203/50 Phase-only modulation

Abstract

A liquid crystal active lens having, in combination, a fixed-focal-point lens having a high index of refraction and a phase modulation element comprising two-dimensionally arranged fine pixels, and having power and being capable of electrically controlling the lens characteristics as a function of space. An electrically controlled optical system can be realized without having a moving portion. Owing to the combination of the liquid crystal element for modulating space phase and the high-power lens of a fixed focal length, it is possible to electronically control the focal length and to electronically control the lens in a spatially split manner.

Claims

1. An optical device for electrically controlling optical characteristics, comprising:

an electrically controlled phase modulation liquid crystal element having a plurality of fine image pixels with a variable refractive force, said fine image pixels being positioned relative to one another in two dimensions for modulating a phase of transmitted light waves;

a plurality of drive electrodes, including timing and data electrodes, coupled to the phase modulation liquid crystal element for driving each of said fine image pixels by time division, and

a lens with a fixed focus and having either a positive or negative refractive force larger than the refractive force of the fine image pixels optically coupled to the phase modulation liquid crystal element to define an optical system.

2. An optical device according to claim 1, wherein the liquid crystal element is a parallel-oriented nematic liquid crystal element.

3. An optical device according to claim 1, wherein the liquid crystal element is a nematic liquid crystal element having a twisted structure.

4. An optical device according to claim 1, wherein the phase modulation liquid crystal element comprises:

a glass substrate,

said plurality of drive electrodes forming an integral structure on said glass substrate;

an integrated circuit mounted to said glass substrate and coupled to the plurality of drive electrodes; and

a drive circuit mounted on the glass substrate coupled to and driven by the integrated circuit for driving the fine image liquid crystal pixels.

5. An optical device according to claim 1, further comprising an amplitude modulation element of the time-division driven fine liquid crystal pixels for removing or suppressing optical noise components.

6. An optical device according to claim 1, wherein the electrically controlled phase modulation element of the time-division driven fine liquid crystal pixels and the lens in combination control the focal length of the optical device.

7. An optical device according to claim 1, wherein the electrically controlled phase modulation element varies magnification while maintaining a fixed focal length.

8. An optical device according to claim 1, wherein the electrically controlled phase modulation element controls an image-forming position of the lens on a plane at right angles to an optical axis.

9. An optical device according to claim 1, wherein the electrically controlled phase modulation element controls tracing of focal length of the optical system for transmitting an image near a preset image focusing position to a pupil location to mask light over areas where no image is formed.

10. An optical device according to claim 4, wherein the electrically controlled phase modulation element corrects distortion of the optical system.

11. An optical device according to claim 1, wherein the electrically controlled phase modulation element electrically corrects astigmatic spectacles and prebyopia in a composite manner.

12. An optical device according to claim 1, wherein the electrically controlled phase modulation element identifies an image by image information, said image information being separately set or identification confirmed and judged.

13. An optical device according to claim 1, further comprising, a color filter disposed on the fine liquid crystal pixels, said color filter and electrical control of the pixels being operative to correct a color aberration of an image, to separate a color, or to change the color in a time division manner.

14. An optical device according to claim 1 wherein the electrically controlled phase modulation element forms an optical interconnection, said optical interconnection coupling first multi-point optical information terminals and second multi-point optical information terminals while maintaining an image-forming relationship with the phase modulation element.

15. An optical device according to claim 1 wherein the electrically controlled phase modulation element forms a neural network, said neural network employing an optical interconnection, said optical interconnection coupling first multi-point optical information terminals and second multi-point optical information terminals while maintaining an image-forming relationship with the phase modulation element.