Image display system having direct and projection viewing modes

• US 6,414,728 B1
• Filed: 02/18/2000
• Issued: 07/02/2002
• Est. Priority Date: 04/21/1994
• Status: Expired due to Fees

• Current Assignee: Reveo, Inc.
• Original Assignee: Reveo, Inc.
• Inventors: Faris, Sadeg M., Li, Le
• Primary Examiner(s): Sikes, William L.
• Assistant Examiner(s): Duong, Tai V.
• Application Number:
  US09/507,244
• Time in Patent Office: 865 Days
• Field of Search: 349/10, 349/15, 349/61, 349/64, 349/65, 349/68, 349/77, 349/86, 349/96, 353/122, 353/DIG.5, 353/DIG.2, 353/DIG.3, 353/71, 353/119, 348/758, 348/766
• US Class Current: 349/10
• CPC Class Codes: G02B 27/0093 with means for monitoring data relating to the user, e.g. head-tracking, eye-tracking
• CPC Class Codes: G02B 30/25 using polarisation techniques
• CPC Class Codes: G02F 1/1334 based on polymer dispersed liquid crystals, e.g. microencapsulated liquid crystals
• CPC Class Codes: G02F 1/133538 with spatial distribution of the polarisation direction
• CPC Class Codes: G02F 1/1336 Illuminating devices
• CPC Class Codes: G02F 1/133627 Projection-direct viewing
• CPC Class Codes: G03B 21/132 Overhead projectors, i.e. capable of projecting hand-writing or drawing during action epidiascopic projectors G03B21/08
• CPC Class Codes: G03B 21/30 adapted to collapse or fold, e.g. for portability
• CPC Class Codes: G06F 1/1616 with folding flat displays, e.g. laptop computers or notebooks having a clamshell configuration, with body parts pivoting to an open position around an axis parallel to the plane they define in closed position
• CPC Class Codes: G06F 1/1626 with a single-body enclosure integrating a flat display, e.g. Personal Digital Assistants [PDAs]
• CPC Class Codes: G06F 1/1632 External expansion units, e.g. docking stations
• CPC Class Codes: G06F 1/1639 the display being based on projection
• CPC Class Codes: G06F 1/1645 the display being suitable to be used in combination with an external overhead projector
• CPC Class Codes: G06F 1/1654 the display being detachable, e.g. for remote use
• CPC Class Codes: G06F 3/011 Arrangements for interaction with the human body, e.g. for user immersion in virtual reality blind teaching G09B21/00
• CPC Class Codes: G06F 3/041 Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: H04N 19/597 specially adapted for multi-view video sequence encoding
• CPC Class Codes: H04N 5/7441 the modulator being an array of liquid crystal cells
• CPC Class Codes: H04N 5/7491 of head mounted projectors
• CPC Class Codes: H04N 9/3141 : Constructional details thereof details not peculiar to the presence of an electronic spatial light modulator G03B21/14

Abstract

A transportable image display system having direct and projection viewing modes of operation. The image display system comprises a spatial light modulation structure for spatially modulating the intensity of light produced from a light source, and light diffusing panel of electro-optical construction having a light scattering state in which light being transmitted therethrough is scattered in a diffusive manner, and a light transmission state in which light being transmitted therethrough is transmitted without substantial scattering. In the illustrative embodiments, the spatial light modulation structure can be an electrically-addressable LCD panel, or slide-film structures to be viewed. During the direct viewing mode, light produced from the light source is scattered by the light diffusing panel and spatial intensity modulated by the spatial light modulation structure to form a first image for direct viewing. During the projection viewing mode, light produced from the light source is transmitted through the light diffusing panel without substantial scattering and spatial intensity modulated by the spatial light modulation structure to form a second image for projection onto a projection display surface for projection viewing.

Claims

1. An image display system having direct and projection viewing modes, comprising;

a light producing structure for producing light during said direct and projection viewing modes;

an electro-optical light diffusing panel having a light scattering state in which light being transmitted therethrough is scattered in a diffusive manner, and a light transmission state in which light being transmitted therethrough is transmitted without substantial scattering;

a spatial light intensity modulation structure for spatially modulating the intensity of light produced from said light producing means during said direct viewing mode and during said projection viewing mode; and

a state selection structure for selecting the light scattering state of said electro-optical light-diffusing panel during said direct viewing mode, and the light transmission state of said electro-optical light-diffusing panel during said projection viewing mode;

wherein during said direct viewing mode, light produced from said light producing structure is scattered by said electro-optical light diffusing panel and spatial intensity modulated by said spatial light intensity modulation structure to form a first image for direct viewing; and

wherein during said projection viewing mode, light produced from said light producing structure is transmitted through said electro-optical light diffusing panel without substantial scattering and spatial intensity modulated by said spatial light intensity modulation structure to form a second image for projection onto a projection display surface for projection viewing.

2. The image display system of claim 1, wherein said spatial light modulation structure is an electrically-addressable spatial light intensity modulation panel that is mounted closely adjacent said light diffusing panel.

3. The image display system of claim 2, wherein said light diffusing panel is disposed between said light producing device and said electrically-addressable spatial light modulation panel.

4. The image display system of claim 3, wherein said light diffusing panel and said electrically-addressable spatial light intensity modulation panel are mounted together to form an integrated display panel assembly.

5. The image display system of claim 4, which further comprises a micropolarization panel mounted onto said electrically-addressable spatial light intensity modulation panel for micropolarizing spatially multiplexed images displayed in either said direct or projection viewing mode.

6. The image display system of claim 2, wherein said electro-optical light diffusing panel comprises a polymer-dispersed liquid crystal (PDLC) panel having optically transparent electrode surfaces.

7. The image display system of claim 2, which further comprises a thin light focusing panel disposed closely adjacent to said electrically-addressable spatial light intensity modulation panel, for focusing spatial intensity modulated light onto said projection display surface located at a predetermined focal plane during said projection viewing mode.

8. The image display panel of claim 7, wherein said thin light focusing panel comprises an optical element selected from the group consisting of a holographic lens panel and a Fresnel lens panel.

9. The image display system of claim 2, wherein said electrically-addressable spatial light intensity modulation panel comprises an active-matrix LCD panel.

10. The image display system of claim 9, wherein said light producing structure produces light having a polarization state which is employed by said active-matrix LCD panel.

11. The image display system of claim 1, wherein said spatial light modulation structure is disposed near said light producing structure.

12. The image display system of claim 11, wherein said spatial light intensity modulation structure is an electrically-addressable spatial light intensity modulation panel disposed between said light producing structure and said electro-optical light diffusing panel.

13. The image display system of claim 11, which further comprises a variable-focus projection lens system disposed near said spatial light intensity modulation structure, said variable-focus projection lens system having at least a first focal distance for focusing spatial intensity modulated light from said spatial light intensity modulation panel onto said electro-optical light diffusing panel during said projection viewing mode, and a second focal distance for projecting spatial intensity modulated light from said spatial light intensity modulation structure through said electro-optical light diffusing panel, onto said projection display surface located at said second focal distance, during said projection viewing mode.

14. The image display system of claim 12, which further comprises a micropolarization panel mounted onto said electrically-addressable spatial light intensity modulation panel for micropolarizing spatially multiplexed images displayed in either said direct or projection viewing mode.

15. The image display system of claim 14, wherein said electrically-addressable spatial light intensity modulation panel and said micropolarization panel are mounted together to form an integrated electro-optical structure.

16. The image display system of claim 13, wherein said electro-optical light diffusing panel comprises a polymer-dispersed liquid crystal (PDLC) panel having optically transparent electrode surfaces.

17. The image display system of claim 12, wherein said electrically-addressable spatial light intensity modulation panel comprises an active-matrix LCD panel.

18. The image display system of claim 17, wherein said light producing structure produces light having a polarization state which is employed by said active-matrix LCD panel.

19. The image display system of claim 1, which further comprises a transportable housing of compact construction having an interior volume within which the components of said image display system are enclosed, and a light transmission aperture through which spatial intensity modulated light can be transmitted during said direct and projection viewing modes.

20. The image display system of claim 11, wherein said spatial light intensity modulation structure is a slide-film structure to be viewed.