Virtual stereographic display system

• US 4,870,486 A
• Filed: 07/20/1988
• Issued: 09/26/1989
• Est. Priority Date: 02/17/1986
• Status: Expired due to Term

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Tsubota, Kojiro, Nakagawa, Kenichi, Yamamoto, Kunihiko
• Primary Examiner(s): Britton, Howard W.
• Application Number:
  US07/221,601
• Time in Patent Office: 433 Days
• Field of Search: 358/88, 358/92, 350/132, 350/350 S
• US Class Current: 349/15
• CPC Class Codes: G02B 30/24 involving temporal multiplexing, e.g. using sequentially activated left and right shutters
• CPC Class Codes: G02F 1/141 using ferroelectric liquid crystals
• CPC Class Codes: G03B 35/24 using apertured or refractive resolving means on screens or between screen and eye
• CPC Class Codes: H04N 13/00 Stereoscopic video systems; Multi-view video systems; Details thereof
• CPC Class Codes: H04N 13/337 using polarisation multiplexing
• CPC Class Codes: H04N 13/341 using temporal multiplexing
• CPC Class Codes: H04N 13/398 Synchronisation thereof; Control thereof

Abstract

A virtual stereographic display system which includes a display image surface, a polarizer disposed before the display image surface, a liquid crystal cell in which ferroelectric smectic liquid crystal is aligned, and disposed before the polarizer, a driving circuit connected to the liquid crystal cell so as to apply AC voltage synchronized with the frame signal of the image on the display image surface to the liquid crystal cell and to switch over the polarization axes of the display light proceeding from the display image surface through the polarizer and liquid crystal cell by time division, and polarizing glasses having different polarization axes for the left eye and right eye for viewing the display light.

Claims

1. A virtual stereographic display system comprising:

a display image surface;

a polarizer disposed adjacent to said display image surface;

a liquid crystal cell having a ferroelectric smectic liquid crystal aligned therein and being disposed adjacent to said polarizer;

a driving circuit connected to said liquid crystal cell for applying an AC voltage synchronized with a frame signal of an image on said display image surface to said liquid crystal cell and for switching polarization axes of display light developed from said display image surface through said polarizer and said liquid crystal cell by time division; and

polarizing glasses having a first polarization axis for the left eye and a second polarization axis for the right eye for viewing the display light.

2. A virtual stereographic display system as claimed in claim 1, wherein said liquid crystal cell has retardation in the range of 0.1 to 0.15 micron and rotational angles of an optical axis due to polarity inversion of said AC voltage in the range of 70°

to 110°

with a general coincidence between a middle line of bi-directional axes which can be taken as the optical axis and the polarization axis of said polarizer, said polarizing glasses having polarizing plates which are circular polarizing plates or elliptic polarizing plates for developing a polarizing efficiency close to circularly polarized light.

3. A virtual stereographic display system as claimed in claim 1, wherein said liquid crystal cell has retardation in the range of 0.2 to 0.3 micron and rotational angles of an optical axis due to polarity inversion of said AC voltage in the range of 35°

to 55°

with a general coincidence between one axis of bi-directional axes which can be taken as the optical axis and the polarization axis of said polarizer, said polarizing glasses having polarizing plates which are plane-polarizing plates.

4. A virtual stereographic display system as claimed in claim 1, wherein said liquid crystal cell has retardation in the range of 0.2 to 0.3 micron and rotational angles of an optical axis due to polarity inversion of said AC voltage in the range of 35°

to 55°

with a general coincidence between one axis of bi-directional axes which can be taken as the optical axis and the polarization axis of said polarizer, said display system further including a quarter-wave plate disposed in front of said liquid crystal cell to form the optical axis in the range of 35°

to 55°

with respect to the polarization axis of said polarizer, said polarizing glasses having polarizing plates which are circular polarizing plated or elliptic polarizing plates for developing a polarizing efficiency close to circularly polarized light.

5. A virtual stereographic display system comprising:

a display image surfce;

a liquid crystal cell having ferroelectric smectic liquid crystal mixed with dichroic dye enclosed therein and being disposed adjacent to said display image surface;

a driving circuit connected to said liquid crystal cell for applying an AC voltage synchronized with a frame signal of an image on said display image surface to said liquid crystal cell and for switching polarization axes of display light developed from said display image surface through said liquid crystal cell by time division; and

polarizing glasses having a first polarization axis for the left eye and a second polarization axis for the right eye for viewing the polarized display light.

6. A virtual stereographic display system as claimed in claim 5, wherein the polarization of said polarized glasses is of a plane-polarization.

7. A virtual stereographic display system as claimed in claim 5, wherein a quarter-wave plate is disposed adjacent to said liquid crystal cell, said polarizing glasses being of circular polarization or elliptic polarization for developing the polarization close to the circular polarization.

8. A virtual stereographic display system comprising:

a display image surface for alternately displaying a right eye image and a left eye image; and

observation glasses for observing said display image surface, said observation glasses having light valve means arranged to alternately open and close the right and left eye portions thereof in response to voltages in a waveform synchronized with a frame signal of said right and left eye images, said light valve means having liquid crystal cells in which ferroelectric smectic liquid crystal is enclosed therein, said liquid crystal cells being in a transparent state when a DC voltage is applied thereto, and said liquid crystal cells being in a transient light scattering state when the polarity of said DC voltage is reversed.

9. A virtual stereographic display system as claimed in claim 8, wherein said display image surface comprises a display surface from a television set.

10. A virtual stereographic display system as claimed in claim 8, wherein said display image surface comprises a screen on which said right and left eye images are projected by a film projector.

11. A virtual stereographic display system comprising:

a display image surface for alternately displaying a right eye image and a left eye image; and

means for observing a light signal from said right and left eye images with a light valve function that is driven in response to voltages having a waveform synchronzed with a frame signal of said right and left eye images, and a brightness variation signal is produced by an output signal from a photosensor which detects brightness variations on the display image surface and said brightness variation signal is synchronized with said frame signal.

12. A virtual stereographic display system as claimed in claim 11, whrein a brightness signal develops a different brightness in response to said right and left eye images is displayed in a predetermined region for said right and left eye images, said brightness signal being judged whether said brightness signal corresponds to said right or left eye images in response to said brightness variation signal as detected by said photosensor.