Backlighting construction for use in computer-based display systems having direct and projection viewing modes of operation

• US 5,801,793 A
• Filed: 10/13/1994
• Issued: 09/01/1998
• Est. Priority Date: 04/21/1994
• Status: Expired due to Fees

• Current Assignee: Reveo, Inc.
• Original Assignee: Reveo, Inc.
• Inventors: Tung, Carl, Faris, Sadeg M.
• Primary Examiner(s): Sikes, William L.
• Assistant Examiner(s): Duong, Tai V.
• Application Number:
  US08/322,219
• Time in Patent Office: 1,419 Days
• Field of Search: 359/40, 359/41, 359/48, 359/53, 359/465, 353/122, 353/71, 353/72, 353/119, 353/DIG. 3, 353/DIG. 5, 345/32, 345/104, 362/31, 362/32, 385/129, 385/130, 385/901, 364/231.1, 349/5, 349/15, 349/57, 349/58, 349/62, 349/64, 349/65, 349/68, 349/86, 349/77, 349/96
• US Class Current: 349/5
• 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: G06F 3/045 using resistive elements, e.g. a single continuous surface or two parallel surfaces put in contact
• CPC Class Codes: H04N 13/133 Equalising the characteristics of different image components, e.g. their average brightness or colour balance
• CPC Class Codes: H04N 13/15 for colour aspects of image signals
• CPC Class Codes: H04N 13/156 : Mixing image signals
• CPC Class Codes: H04N 13/161 : Encoding, multiplexing or demultiplexing different image signal components for multi-view video sequence encoding H04N19/597
• CPC Class Codes: H04N 13/167 : Synchronising or controlling image signals
• CPC Class Codes: H04N 13/189 : Recording image signals; Reproducing recorded image signals
• CPC Class Codes: H04N 13/194 : Transmission of image signals
• CPC Class Codes: H04N 13/204 : using stereoscopic image cameras stereoscopic photography G03B35/00
• CPC Class Codes: H04N 13/218 : using spatial multiplexing
• CPC Class Codes: H04N 13/239 : using two 2D image sensors having a relative position equal to or related to the interocular distance H04N13/243 takes precedence
• CPC Class Codes: H04N 13/243 : using three or more 2D image sensors
• CPC Class Codes: H04N 13/246 : Calibration of cameras
• CPC Class Codes: H04N 13/257 : Colour aspects
• CPC Class Codes: H04N 13/275 : from 3D object models, e.g. computer-generated stereoscopic image signals
• CPC Class Codes: H04N 13/279 : the virtual viewpoint locations being selected by the viewers or determined by tracking
• CPC Class Codes: H04N 13/286 : having separate monoscopic and stereoscopic modes
• CPC Class Codes: H04N 13/289 : Switching between monoscopic and stereoscopic modes
• CPC Class Codes: H04N 13/296 : Synchronisation thereof; Control thereof
• CPC Class Codes: H04N 13/324 : Colour aspects
• CPC Class Codes: H04N 13/327 : Calibration thereof
• CPC Class Codes: H04N 13/334 : using spectral multiplexing
• CPC Class Codes: H04N 13/337 : using polarisation multiplexing
• CPC Class Codes: H04N 13/341 : using temporal multiplexing
• CPC Class Codes: H04N 13/344 : with head-mounted left-right displays
• CPC Class Codes: H04N 13/359 : Switching between monoscopic and stereoscopic modes
• CPC Class Codes: H04N 13/363 : using image projection screens volumetric display H04N13/388
• CPC Class Codes: H04N 13/368 : for two or more viewers
• CPC Class Codes: H04N 13/373 : for tracking forward-backward translational head movements, i.e. longitudinal movements
• CPC Class Codes: H04N 13/376 : for tracking left-right translational head movements, i.e. lateral movements
• CPC Class Codes: H04N 13/38 : for tracking vertical translational head movements
• CPC Class Codes: H04N 13/383 : for tracking with gaze detection, i.e. detecting the lines of sight of the viewer's eyes
• CPC Class Codes: H04N 13/398 : Synchronisation thereof; Control thereof
• 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 reconfigurable backlighting construction for use in portable computer-based systems having direct and projection viewing modes of operation. In the illustrative embodiments of the present invention, the backlighting construction is integrated with a LCD display panel, a micropolarization panel, and a touch-screen writing panel to provide several different types of portable computer-based systems including, for example, a portable notebook computer, a computer-driven image display device, and a portable pen-computing device. In general, each of these computer-based systems are capable of selectively displaying color video images on an actively driven display surface, or projecting such video images onto a wall surface or projection screen without the need for a bulky overhead projector, required by all prior art systems. These computer-based systems can be easily reconfigured for projection viewing without physical removal of the light guiding panel and its light diffusing structures. If desired, these computer-based systems can be used to directly view "spatially-multiplexed" images of 3-D objects or imagery during the direct viewing mode, and when desired these spatially-multiplexed images can be projected onto a wall surface or projection screen during the projection viewing mode. When the spatially-multiplexed images are viewed through electrically-passive polarized glasses, the 3-D object is perceived with stereoscopic depth sensation in either mode of viewing. A portable light projection accessory device is provided for use with the portable computer-based systems of the present invention. In the illustrative embodiments, the portable light projection device has first and second housing portions that are interconnected by a foldable structure that permits the first and second housing portions to be selectively reconfigured for simple trouble-free use during the projection viewing mode of operation, and for compact storage during the direct viewing mode of operation.

Claims

1. A reconfigurable backlighting construction installed in a computer-based system having a transportable housing, first and second modes of operation, and first and second light transmission apertures formed in said transportable housing, said backlighting construction comprising

light producing means installed in said transportable housing, for producing light in the direction of a projection axis during said first mode;

a thin lens panel mounted in said transportable housing along said projection axis;

a light guiding panel having first and second end portions, and first and second light guiding surfaces between which said produced light can be totally internally reflected;

first support means mounted to said first end portion of said light guiding panel, for pivotally supporting said light guiding panel adjacent said thin lens panel during said first mode, and at a preselectable angle with respect to said thin lens panel during said second mode;

a rear housing panel having an interior surface and first and second end portions and a spatial extent sufficient for covering a substantial portion of said first light transmission aperture during said first mode;

a light reflective surface adjacent the interior surface of said rear housing panel;

second support means connected between said second end portion of said light guiding panel and said first end portion of said rear housing panel, for pivotally supporting said rear housing panel adjacent said light guiding panel and said light guiding panel adjacent said thin lens panel during said first mode, and for supporting said rear housing panel adjacent said light guiding panel and said light reflective surface at said preselected angle with respect to said thin lens panel during said second mode;

a light diffusing structure operably associated with said light guiding panel, for scattering light within said light guiding panel during said first mode;

wherein during said first mode, light is produced from said light producing means and is reflected and scattered within said light guiding panel and a portion of said scattered light is transmitted through said first light guiding surface of said light guiding panel along said projection axis, and

wherein during said second mode, light is produced from an external source and is reflected off said light reflective surface and transmitted through said thin lens panel along said projection axis.

2. The reconfigurable backlighting construction of claim 1, wherein said light guiding panel further comprises a first light conducting edge through which light produced from said light producing means can be transmitted into said light guiding panel for total internal reflection between said first and second light guiding surfaces.

3. The reconfigurable backlighting construction of claim 1, wherein said light diffusing structure comprises first and second light diffusing layers disposed adjacent said first and second light guiding surfaces respectively for selectively scattering light within said light guiding panel so that a substantially uniform light intensity distribution emanates therefrom in the direction of said thin lens panel during said first mode.

4. The reconfigurable backlighting construction of claim 1, wherein said light guiding panel is made from an optically transparent plastic, and said thin lens panel is selected from the group consisting of a Fresnel lens panel and a holographic lens panel.

5. The reconfigurable backlighting construction of claim 1, wherein said light guiding panel has first and second light conducting edges, and wherein said light producing means comprises first and second fluorescent tubes disposed along said first and second light conducting edges, respectively, said first and second fluorescent tubes producing and transmitting light through said first and second light conducting edges during said first mode.

6. The reconfigurable backlighting construction of claim 5, which further comprises first and second light focusing elements disposed in proximity with said first and second fluorescent tubes, respectively, for focusing light produced from said first and second fluorescent tubes and directing said focused light across said first and second light conducting edges and into said light guiding panel.

7. The reconfigurable backlighting construction of claim 1, in combination with a programmable spatial light mask affixed to said thin lens panel.

8. The reconfigurable backlighting construction of claim 7, which further comprises a micropolarization panel affixed to said programmable spatial light mask.

9. The reconfigurable backlighting construction of claim 1, wherein said preselectable angle is about 45 degrees.

10. An image display device having direct and projection viewing modes of operation, said image display device comprising:

a transportable housing having first and second light transmission apertures formed therethrough;

light producing means installed in said transportable housing, for producing light along a projection axis during said direct viewing mode;

a thin lens panel mounted in said transportable housing along said projection axis;

a light guiding panel having first and second end portions, and first and second light guiding surfaces between which said produced light can be totally internally reflected;

first support means mounted to said first end portion of said light guiding panel, for pivotally supporting said light guiding panel adjacent said thin lens panel during said direct viewing mode, and for pivotally supporting said light guiding panel at a preselectable angle with respect to said thin lens panel during said projection viewing mode;

a rear housing panel having an interior surface and first and second end portions and a spatial extent sufficient for covering a substantial portion of said first light transmission aperture during said direct viewing mode;

a light reflective surface disposed adjacent the interior surface of said rear housing panel;

second support means connected between said second end portion of said light guiding panel and said first end portion of said rear housing panel, for pivotally supporting said rear housing panel adjacent said light guiding panel and said light guiding panel adjacent said thin lens panel during said direct viewing mode, and for supporting said rear housing panel adjacent said light guiding panel and said light reflective surface at a preselectable angle with respect to said thin lens panel during said projection viewing mode;

a light diffusing structure operably associated with said light guiding panel, for scattering light within said light guiding panel during said direct viewing mode;

a programmable spatial light mask, disposed in said transportable housing, and having a display surface and means for spatially modulating the intensity of light transmitted through said programmable spatial light mask during said projection viewing mode;

wherein during said direct viewing mode, light is produced from said light producing means and is reflected within said light guiding panel and scattered by said light diffusing structure and a portion of said scattered light is transmitted through said first light guiding surface and said programmable spatial light mask, whereupon said transmitted light is spatial-intensity modulated so as to form a light image on the display surface of said programmable spatial light mask, and

wherein during said projection viewing mode, light is produced from an external source and is reflected off said light reflective surface and transmitted through said thin lens panel and said programmable spatial light mask, whereupon said transmitted light is focused and spatial-intensity modulated so as to form a light image on a viewing surface disposed at a distance from said programmable spatial light mask.

11. The image display device of claim 10, which further comprises means for displaying on said display surface, a composite pixel pattern representative of a spatially multiplexed image composed of first and second spatially modulated perspective images of a 3-D object, said first spatially modulated perspective image consisting of a first pixel pattern representative of a first perspective image of said 3-D object spatially modulated according to a first spatial modulation pattern, said second spatially modulated perspective image consisting of a second pixel pattern representative of a second perspective image of said 3-D object spatially modulated according to a second spatial modulation pattern, and said second spatial modulation pattern being a logical complement of said first spatial modulation pattern, and

wherein said image display device further comprises a micropolarization panel comprising a optically transparent sheet mounted onto said display surface of said programmable spatial light mask, said optically transparent sheet having first and second optically transparent patterns permanently formed in first optically transparent sheet, said first optically transparent pattern spatially corresponding to and being spatially aligned with said first pixel pattern so as to impart a first polarization state P₁ to said first pixel pattern, and said second optically transparent pattern spatially corresponding to and being spatially aligned with said second pixel pattern so as to impart a second polarization state P₂ to said second pixel pattern, said second polarization state P₂ being different than said first polarization state P₁.

12. The image display device of claim 11, wherein said thin lens panel is selected from the group consisting of a Fresnel lens panel and a holographic lens panel.

13. The image display device of claim 10, wherein said light guiding panel has first and second light conducting edges, and wherein said light producing means comprises first and second fluorescent tubes disposed along said first and second light conducting edges, respectively, said first and second fluorescent tubes producing and transmitting light through said first and second light conducting edges during said direct viewing mode.

14. The image display device of claim 13, which further comprises first and second light focusing elements disposed in proximity with said first and second fluorescent tubes, respectively, for focusing light produced from said first and second fluorescent tubes and directing said focused light across said first and second light conducting edges and into said light guiding panel.

15. A portable computer-based system having direct and projection viewing modes of operation, comprising:

a transportable housing of compact construction and having first and second light transmission apertures formed therein and aligned with each other;

data storage means, disposed in said transportable housing, for storing data representative of one or more light images to be displayed;

a reconfigurable backlighting construction disposed in said transportable housing and having direct and projection viewing modes of operation, said reconfigurable backlighting construction including

light producing means installed in said transportable housing, for producing light in the direction of a projection axis during said direct viewing mode,

a thin lens panel mounted in said transportable housing along said projection axis,

a light guiding panel having first and second end portions, and first and second light guiding surfaces between which said produced light can be totally internally reflected,

first support means mounted to said first end portion of said light guiding panel, for pivotally supporting said light guiding panel adjacent said thin lens panel during said direct viewing mode, and for pivotally supporting said light guiding panel at a preselectable angle with respect to said thin lens panel during said projection viewing mode,

a rear housing panel having an interior surface and first and second end portions and a spatial extent sufficient for covering a substantial portion of said first light transmission aperture during said direct viewing mode,

a light reflective surface disposed adjacent the interior surface of said rear housing panel,

second support means connected between said second end portion of said light guiding panel and said first end portion of said rear housing panel, for pivotally supporting said rear housing panel adjacent said light guiding panel and said light guiding panel adjacent said thin lens panel during said direct viewing mode, and for supporting said rear housing panel adjacent said light guiding panel and said light reflective surface at said preselectable angle with respect to said thin lens panel during said projection viewing mode, and

a light diffusing structure operably associated with said light guiding panel, for scattering light within said light guiding panel during said direct viewing mode;

a programmable spatial light mask, disposed adjacent said thin lens panel, and having a display surface and means for spatially modulating the intensity of light transmitted through said programmable spatial light mask;

wherein during said direct viewing mode, light is produced from said light producing means and is reflected within said light guiding panel and scattered by said light diffusing structure, and a portion of said scattered light is transmitted through said first light guiding surface and said programmable spatial light mask, whereupon said transmitted light is spatial-intensity modulated so as to form a light image on the display surface of said programmable spatial light mask, and

wherein during said projection viewing mode, light is produced from an external source and is reflected off said light reflective surface and transmitted through said thin lens panel and said programmable spatial light mask, whereupon said transmitted light is focused and spatial-intensity modulated so as to produce a light pattern on a viewing surface disposed at a distance from said programmable spatial light mask.

16. The portable computer-based system of claim 15, wherein said preselectable angle is about 45 degrees.

17. The portable computer-based system of claim 16, wherein said light guiding panel further comprises a first light conducting edge through which light produced from said light producing means can be transmitted into said light guiding panel for total internal reflection between said first and second light guiding surfaces.

18. The portable computer-based system of claim 17, which further comprises:

means for displaying on said display surface, a composite pixel pattern representative of a spatially multiplexed image composed of first and second spatially modulated perspective images of a 3-D object, said first spatially modulated perspective image consisting of a first pixel pattern representative of a first perspective image of said 3-D object spatially modulated according to a first spatial modulation pattern, said second spatially modulated perspective image consisting of a second pixel pattern representative of a second perspective image of said 3-D object spatially modulated according to a second spatial modulation pattern, said second spatial modulation pattern being a logical complement of said first spatial modulation pattern; and

a micropolarization panel comprising an optically transparent sheet mounted onto said display surface of said programmable spatial light mask, said optically transparent sheet having first and second optically transparent patterns permanently formed in said optically transparent sheet, said first optically transparent pattern spatially corresponding to and being spatially aligned with said first pixel pattern so as to impart a first polarization state P₁ to said first pixel pattern, and said second optically transparent pattern spatially corresponding to and being spatially aligned with said second pixel pattern so as to impart a second polarization state P₂ to said second pixel pattern, said second polarization state P₂ being different than said first polarization state P₁.

19. The portable computer-based system of claim 15, which further comprises a display control means for controlling the spatial intensity of light emerging from said programmable spatial light mask, and

wherein said programmable spatial light mask comprises a liquid crystal display panel comprising an array of electrically addressable pixels, each said pixel having a light transmittance that is controllable by said display control means.

20. The portable computer-based system of claim 15, wherein said light guiding panel is made from a optically transparent plastic.

21. The portable computer-based system of claim 16, wherein said light guiding panel comprises first and second light conducting edges, and wherein said light producing means comprises first and second fluorescent tubes disposed along said first and second light conducting edges, respectively, said first and second fluorescent tubes producing and transmitting light through said first and second light conducting edges during said direct viewing mode.

22. The portable computer-based system of claim 21, wherein said reconfigurable backlighting construction further comprises

first and second light focusing elements disposed in proximity with said first and second fluorescent tubes, respectively, for focusing light produced from said first and second fluorescent tubes and directing said focused light across said first and second light conducting edges and into said light guiding panel.

23. An image display device having direct and projection viewing modes of operation, comprising:

a transportable housing having first and second light transmission apertures formed therein and aligned with each other;

light producing means installed in said transportable housing, for producing light in the direction of a projection axis during said direct viewing mode;

a thin lens panel mounted in said transportable housing along said projection axis;

a light guiding panel having first and second light guiding surfaces between which said produced light can be totally internally reflected;

a rear housing panel for covering a substantial portion of said first light transmission aperture during said direct viewing mode, and having an interior surface;

a light reflective surface disposed on said interior surface of said rear housing panel;

a light diffusing structure operably associated with said light guiding panel, for scattering light within said light guiding panel during said direct viewing mode;

a programmable spatial light mask disposed adjacent said thin lens panel, having a display surface and means for spatially modulating the intensity of light transmitted through said thin lens panel during said projection viewing mode;

wherein during said direct viewing mode, light is produced from said light producing means and is reflected within said light guiding panel and scattered by said light diffusing structure, and a portion of said scattered light is transmitted through said first light guiding surface and said programmable spatial light mask, whereupon said transmitted light is spatial-intensity modulated so as to form a light image on the display surface of said programmable spatial light mask; and

wherein during said projection viewing mode, light is produced from an external source and is transmitted through said thin lens panel and said programmable spatial light mask, whereupon said transmitted light is focused and spatial-intensity modulated so as to form a light image on a viewing surface disposed at a distance from said programmable spatial light mask.

24. The image display device of claim 23, which further comprises

means for displaying on said display surface, a composite pixel pattern representative of a spatially multiplexed image composed of first and second spatially modulated perspective images of a 3-D object, said first spatially modulated perspective image consisting of a first pixel pattern representative of a first perspective image of said 3-D object spatially modulated according to a first spatial modulation pattern, said second spatially modulated perspective image consisting of a second pixel pattern representative of a second perspective image of said 3-D object spatially modulated according to a second spatial modulation pattern, said second spatial modulation pattern being a logical complement of said first spatial modulation pattern, and

a micropolarization panel comprising an optically transparent sheet mounted onto said display surface of said spatial light mask, said optically transparent sheet having first and second optically transparent patterns permanently formed in said optically transparent sheet, said first optically transparent pattern spatially corresponding to and being spatially aligned with said first pixel pattern so as to impart a first polarization state P₁ to said first pixel pattern, and said second optically transparent pattern spatially corresponding to and being spatially aligned with said second pixel pattern so as to impart a second polarization state P₂ to said second pixel pattern, said second polarization state P₂ being different than said first polarization state P₁.

25. The image display device of claim 24 in combination with electrically-passive polarization glasses.

26. The image display device of claim 23, wherein said light guiding panel has first and second light conducting edges, and wherein said light producing means comprises first and second fluorescent tubes disposed along said first and second light conducting edges, respectively, said first and second fluorescent tubes producing and transmitting light through said first and second light conducting edges during said direct viewing mode.

27. The image display device of claim 26, which further comprises first and second light focusing elements disposed in proximity with said first and second fluorescent tubes, respectively, for focusing light produced from said first and second fluorescent tubes and directing said focused light across said first and second light conducting edges and into said light guiding panel.

28. The image display device of claim 23, which further comprises an optically transparent touch-screen panel disposed adjacent said programmable spatial light mask.

29. A portable computer-based system having direct and projection viewing modes of operation, comprising:

(A) a transportable housing of compact construction and having first and second light transmission apertures formed therein and aligned with each other;

(B) data storage means, disposed in said transportable housing, for storing data representative of one or more light images to be displayed;

(C) a backlighting construction disposed in said transportable housing, having direct and projection viewing modes of operation, and including

(1) light producing means installed in said transportable housing, for producing light in the direction of a projection axis during said direct viewing mode,

(2) a thin lens panel mounted in said transportable housing along said projection axis,

(3) a light guiding panel having first and second end portions, and first and second light guiding surfaces between which said produced light can be totally internally reflected,

(4) a rear housing panel having a spatial extent sufficient for covering a substantial portion of said first light transmission aperture during said direct viewing mode,

(5) a light reflective surface disposed adjacent the interior surface of said rear housing panel, and

(6) a light diffusing structure operably associated with said light guiding panel, for scattering light within said light guiding panel during said direct viewing mode;

(D) a programmable spatial light mask, disposed adjacent said thin lens panel, having a display surface and means for spatially modulating the intensity of light transmitted through said programmable spatial light mask;

wherein during said direct viewing mode, light is produced by said light producing means and is reflected within said light guiding panel and scattered by said light diffusing structure, and a portion of said scattered light is transmitted through said first light guiding surface and said programmable spatial light mask, whereupon said transmitted light is spatial-intensity modulated so as to form a light pattern on the display surface of said programmable spatial light mask, and

wherein during said projection viewing mode, light is produced from an external source and is reflected off said light reflective surface and transmitted through said thin lens panel and said programmable spatial light mask, whereupon said transmitted light is focused and spatial-intensity modulated so as to form a light image on a viewing surface at a distance from said programmable spatial light mask.

30. The portable computer-based system of claim 29, wherein said light guiding panel further comprises a first light conducting edge through which light produced from said light producing means can be transmitted into said light guiding panel for total internal reflection between said first and second light guiding surfaces.

31. The portable computer-based system of claim 29, which further comprises:

means for displaying on said display surface, a composite pixel pattern representative of a spatially multiplexed image composed of first and second spatially modulated perspective images of a 3-D object, said first spatially modulated perspective image consisting of a first pixel pattern representative of a first perspective image of said 3-D object spatially modulated according to a first spatial modulation pattern, said second spatially modulated perspective image consisting of a second pixel pattern representative of a second perspective image of said 3-D object spatially modulated according to a second spatial modulation pattern, said second spatial modulation pattern being a logical complement of said first spatial modulation pattern; and

a micropolarization panel comprising a optically transparent sheet mounted onto said display surface of said programmable spatial light mask, said optically transparent sheet having first and second optically transparent patterns permanently formed in said optically transparent sheet, said first optically transparent pattern spatially corresponding to and being spatially aligned with said first pixel pattern so as to impart a first polarization state P₁ to said first pixel pattern, and said second optically transparent pattern spatially corresponding to and being spatially aligned with said second pixel pattern so as to impart a second polarization state P₂ to said second pixel pattern, said second polarization state P₂ being different than said first polarization state P₁.

32. The portable computer-based system of claim 29, which further comprises

a display control means for controlling the spatial intensity of light emerging from said programmable spatial light mask, and

wherein said programmable spatial light mask comprises a liquid crystal display panel comprising an array of electrically addressable pixels, each said pixel having a light transmittance that is controllable by said display control means.

33. The portable computer-based system of claim 29, wherein said light guiding panel is made from a optically transparent plastic.

34. The portable computer-based system of claim 29, wherein said light guiding panel comprises first and second light conducting edges, and wherein said light producing means comprises first and second fluorescent tubes disposed along said first and second light conducting edges, respectively, said first and second fluorescent tubes producing and transmitting light through said first and second light conducting edges during said direct viewing mode.

35. The portable computer-based system of claim 29, wherein said backlighting construction further comprises

first and second light focusing elements disposed in proximity with said first and second fluorescent tubes, respectively, for focusing light produced from said first and second fluorescent tubes and directing said focused light across said first and second light conducting edges and into said light guiding panel.

36. An image display device having direct and projection viewing modes of operation, comprising:

a transportable housing having first and second light transmission apertures formed therein and aligned with each other;

light producing means installed in said transportable housing, for producing light along a projection axis during said direct viewing mode;

a thin light focusing element mounted in said transportable housing along said projection axis;

a rear housing panel having an interior surface and a spatial extent sufficient for covering a substantial portion of said first light transmission aperture during said direct viewing mode;

a light guiding panel attached to said rear housing portion, and having first and second light guiding surfaces between which said produced light can be totally internally reflected, said light guiding panel having first and second light conducting edges;

said light producing means including first and second fluorescent tubes disposed along said first and second light conducting edges, respectively, and said first and second fluorescent tubes producing and transmitting light through said first and second light conducting edges during said direct viewing mode;

means for hingedly connecting said light guiding panel or said rear housing panel to said transportable housing;

first and second light focusing elements disposed in proximity with said first and second fluorescent tubes, respectively, for focusing light produced from said first and second fluorescent tubes and directing said focused light across said first and second light conducting edges and into said light guiding panel;

a light reflective surface disposed between said light guiding panel and the interior surface of said rear housing panel;

a light diffusing structure operably associated with said light guiding panel, for scattering light within said light guiding panel during said direct viewing mode; and

a programmable spatial light mask disposed adjacent said thin lens panel, and having a display surface and means for spatially modulating the intensity of light transmitted through said programmable spatial light mask during said projection viewing mode;

wherein during said direct viewing mode, light is produced from said light producing means and is reflected within said light guiding panel and scattered by said light diffusing structure, and a portion of said scattered light is transmitted through said first light guiding surface and said programmable spatial light mask, whereupon said transmitted light is spatial-intensity modulated so as to form a light image on the display surface of said programmable spatial light mask; and

wherein during said projection viewing mode, light is produced from an external source and is transmitted through said thin light focusing element and said programmable spatial light mask, whereupon said transmitted light is focused and spatial-intensity modulated so as to form a light image on a viewing surface disposed at a distance from said programmable spatial light mask.