EP0509630A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
A high efficiency light valve projection system
Assignee: Individual
•
Filing: 1992-02-21
•
Granted: —
•
Expires: 2012-02-21
Abstract
Abstract A light valve such as an active matrix LCD between crossed polarizers, utilizing, for instance, individual transistors to control each "pixel area" of the LCD and storage elements to store video signal data for each pixel, with optically shielded "dead spaces" between pixels to eliminate electric field crosstalk and non-information-bearing light bleed through, is illuminated with a bright independent light source which creates a video image projected via specialized projection optics onto an internal or external screen without distortions, regardless of the angle of projection onto the screen. Use of heat sinks, IR reflective coatings, heat absorbing optics, optional fluid and a thermistor controlled pixel transistor bias voltage injection servo circuit stabilizes image performance, maintaining accurate color and contrast levels as the LCD changes temperature. In one embodiment of the invention, use of a multi-color LCD with a stepped cavity, producing different thicknesses of LCD for the different wavelengths that pass through it, allows a linear correspondence between the wavelengths passing through the LCD to produce true black, high contrast and CRT-like color rendition. A dichroic mirror arrangement is used to overlap differently colored pixels in the projected image. Use of striped mirrors duplicate pixels, where necessary, eliminating spaces between pixels, creating a continuous image with no apparent stripes or dots. A special venetian-blind type of screen is also disclosed and methods for using the system to view three-dimensional video are also explained.
Inventors
- 👤 Eugene Dolgoff
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-04 18:49
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/1333; G02F1/133382; G09; G09G; G09G3/00; G09G3/001; H; H04; H04N; H04N13/00; H04N13/30; H04N13/302; H04N13/305; H04N13/332; H04N13/337; H04N13/363; H04N9/00; H04N9/12; H04N9/31; H04N9/3102; H04N9/3105; H04N9/3108; H04N13/10; H04N13/106; H04N13/111; H04N13/189; H04N13/194; H04N13/20; H04N13/204; H04N13/239; H04N13/261; H04N13/286; H04N13/31; H04N13/324
Claims Analysis
Total Claims: 61
Claim 1
Independent Claim
65 words
An electronic image projection system, comprising: a light source; a light valve for forming an image on which information can be represented as pixels or lines, said light valve including dead spaces between pixels or lines; means for projecting the image formed by said light valve onto a viewing area; and means to substantially eliminate perceived spaces between pixels or lines in the projected image.
Claim 2
Dependent Claim
65 words
An electronic image projection system, comprising: a light source; a light valve for forming an image on which information can be represented as pixels or lines, said light valve including dead spaces between pixels or lines; means for projecting the image formed by said light valve onto a viewing area; and means to substantially eliminate perceived spaces between pixels or lines in the projected image.
Claim 3
Dependent Claim
53 words
The electronic image projection system of Claim 1, further comprising: a pixel storage element associated with each pixel for storing a respective pixel signal; and control means associated with said pixel storage elements for controlling the operation thereof, said control means, pixel storage elements and light valve forming an active matrix light valve.
Claim 4
Dependent Claim
44 words
The electronic image projection system of Claim 1, wherein said control means associated with each pixel includes a transistor, said transistor when turned on by a gate signal, conducts a voltage of a specific value associated with the desired brightness at its respective pixel.
Claim 5
Dependent Claim
18 words
The electronic image projection system of Claim 1, further comprising a light-blocking covering positioned between pixels or lines.
Claim 6
Dependent Claim
42 words
The electronic image projection system of Claim 1, further comprising a heat sensing device for sensing heat in proximity to the active matrix light valve, wherein said device monitors temperature and biases the active matrix, light valve to counter temperature fluctuation effects.
Claim 7
Dependent Claim
32 words
The electronic image projection system of Claim 1, further comprising a plurality of light valves to project multiple images onto the viewing area to produce a black and white or colored image.
Claim 8
Dependent Claim
38 words
The electronic image projection system of Claim 1, further comprising dichroic optics, wherein said dichroic optics overlap differently colored light valve projected images permitting said images to be focussed onto a screen with a single projection lens system.
Claim 9
Dependent Claim
28 words
The electronic image projection system of Claim 1, further comprising a mirror system to duplicate the image of the pixels into the dead spaces between pixels or lines.
Claim 10
Dependent Claim
20 words
The electronic image projection system of Claim 1, further comprising lenses to fill the dead spaces between pixels or lines.
Claim 11
Dependent Claim
26 words
The electronic image projection system of Claim 1, wherein said light valve is a full-color light valve, comprising pixels or lines of a plurality of colors.
Claim 12
Dependent Claim
28 words
The electronic image projection system of Claim 10, wherein light emanating from one of the colored pixels or lines overlaps light emanating from another colored pixel or lines.
Claim 13
Dependent Claim
19 words
The electronic image projection system of Claim 11, wherein image is replicated to fill the dead spaces between pixels.
Claim 14
Dependent Claim
34 words
The electronic image projection system of Claim 11, wherein light emanating from each of the plurality of colored pixels or lines is individually optically expanded, to fill the dead spaces between pixels or lines.
Claim 15
Dependent Claim
51 words
The electronic image projection system of Claim 1, further comprising a projection lens system, wherein said lens system trapezoidally predistorts the image to compensate for keystone distortion resulting from projection of the image onto a surface such that the surface is not normal to the optical axis of the projection lens.
Claim 16
Dependent Claim
55 words
The electronic image projection system of Claim 1, wherein said system projects onto a surface which is not normal to the optical axis of the projection optics, wherein the light valve and projection optics are tilted so that their planes intersect at a line which also intersects the plane of the surface being projected upon.
Claim 17
Dependent Claim
32 words
The electronic image projection system of Claim 1, further comprising a plurality of projection means, wherein the projection means project polarized stereoscopically-related images onto a non-depolarizing screen to be viewed in 3-D.
Claim 18
Dependent Claim
39 words
The electronic image projection system of Claim 1, further comprising a plurality of projection means, wherein said projection means projects images emanating therefrom onto a screen comprising two lenticular lenses positioned back-to-back, restricting angle of view of each image.
Claim 19
Dependent Claim
19 words
The electronic image projection system of Claim 1, further comprising a sound suppression system for eliminating system cooling noise.
Claim 20
Dependent Claim
33 words
The electronic image projection system of Claim 1, wherein the image enters one of two ends of a coherent fiber-optic bundle and is subsequently viewed at the other end of the fiber-optic bundle.
Claim 21
Dependent Claim
28 words
The electronic image projection system of Claim 1, wherein the means for projecting further comprises a means to expand the pixel images to substantially eliminate said dead spaces.
Claim 22
Dependent Claim
29 words
The electronic image projection system of Claim 1, wherein the means for projecting duplicates all or part of the pixel or line images to substantially eliminate said dead spaces.
Claim 23
Dependent Claim
119 words
An electronic image projection system, comprising: a light source; a light valve having a plurality of pixels or lines arranged in a matrix for forming an image; a solid state pixel or line storage element associated with each pixel or line for storing a respective pixel or line control signal; control means associated with said solid state pixel or line storage elements for controlling the operation thereof, said control means, pixel or line storage elements and light valve forming an active matrix light valve, said active matrix light value including dead spaces between pixels or lines; and means for projecting the image formed by said light valve onto a viewing area such that the dead spaces are substantially eliminated.
Claim 24
Dependent Claim
119 words
An electronic image projection system, comprising: a light source; a light valve having a plurality of pixels or lines arranged in a matrix for forming an image; a solid state pixel or line storage element associated with each pixel or line for storing a respective pixel or line control signal; control means associated with said solid state pixel or line storage elements for controlling the operation thereof, said control means, pixel or line storage elements and light valve forming an active matrix light valve, said active matrix light value including dead spaces between pixels or lines; and means for projecting the image formed by said light valve onto a viewing area such that the dead spaces are substantially eliminated.
Claim 25
Dependent Claim
27 words
An electronic image projection system of Claim 1, further comprising a means for coloring the image, wherein said means for coloring is external to the light valve.
Claim 26
Dependent Claim
23 words
The electronic image projection system of Claim 1, wherein a single light valve is divided into sections, each addressed with different image information.
Claim 27
Dependent Claim
23 words
The electronic image projection system of Claim 23 wherein each of said different sections are addressed with information corresponding to a different color.
Claim 28
Dependent Claim
17 words
The electronic image projection system of Claim 1, wherein said light valve is a liquid crystal display.
Claim 29
Dependent Claim
19 words
The electronic image projection system of Claim 1, comprising dichroic optics, wherein said dichroic optics overlap differently colored images.
Claim 30
Dependent Claim
26 words
The electronic image projection system of Claim 1, comprising dichroic optics, wherein said dichroic optics divides light produced by a light source into differently colored beams.
Claim 31
Dependent Claim
71 words
The electronic image projection system of Claim 1, wherein the pixels or lines of a multi- colored light valve are addressed, such that each pixel or line is given data whose value corresponds to the amount of one color of the light present in the image at that particular location, creating a system of color monads, instead of color triads as is normally done, to represent the color of an image.
Claim 32
Dependent Claim
23 words
The electronic image projection system of Claim 1, wherein one or more wedges are used to cause pixel or line images to overlap.
Claim 33
Dependent Claim
45 words
The electronic image projection system of Claim 1, wherein an optical filtering means is utilized between the image forming plane of the light valve and the surface on which the image is projected to reduce the visibility of pixels or lines in the projected image.
Claim 34
Dependent Claim
29 words
The electronic image projection system of Claim 1, further comprising: a condenser means; and a subsystem for superimposing red, green and blue images to form a full color image.
Claim 35
Dependent Claim
31 words
The electronic image projection system of Claim 1, further comprising a lens positioned after the light valve to correct for path length differences between the light valves and the projection lens.
Claim 36
Dependent Claim
71 words
The electronic image projection system of Claim 1, further comprising: a lens array to create real images of at least 2 differently colored pixels or lines from the image to be projected; and wherein said means for projecting includes a projection lens, wherein said lens produces an image of the image plane of the system and blurring the real images of the colored pixels or lines produced by the lens array.
Claim 37
Dependent Claim
77 words
The electronic image projection system of Claim 1, further comprising a lens array, wherein said array contains more lenslets than there are pixels or lines in the image to be displayed; and a second lens array comprising lenslets wherein said second array creates individual pixel or line images that do not display individual red, green and blue pixels or lines or components within any pixel or line image created by any lenslet of the second lens array.
Claim 38
Dependent Claim
32 words
The electronic image projection system of Claim 1, further comprising a means for cooling including a tube with an orifice, wherein said tube directs a high velocity, high pressure stream of air.
Claim 39
Dependent Claim
20 words
The electronic image projection system of Claim 1, further comprising a spatial filter to eliminate the appearance of dead spaces.
Claim 40
Dependent Claim
41 words
The electronic image projection system of Claim 1, further comprising wedges to create at least one extra image on the viewing area, wherein said extra image fills spaces between pixels or lines in the other image projected to the viewing area.
Claim 41
Dependent Claim
110 words
The electronic image projection system of Claim 1, wherein light from said source is separated into a multiplicity of differently colored beams which address the light valve during a first period of time; color filters, wherein said filters are moved into a different position during a second period of time; wherein the multiplicity of colored beams produced illuminates the light valve differently than in the first time period with the information addressing the light valve electronically selected accordingly such that the proper color of light illuminates the proper place on the light valve so that the proper information is projected to a viewing surface and the motion is repeated periodically.
Claim 42
Dependent Claim
85 words
The electronic image projection system of Claim 1, wherein a full color light valve forms a full color image and further comprising a displacing means to displace the image projected to the viewing area wherein over a period of time, red data from one image is superimposed on green data from another image which is superimposed on blue data from another image, creating the appearance of a full color image without the appearance of individual red, green and blue pixels or lines in the image.
Claim 43
Dependent Claim
49 words
The electronic image projection system of Claim 1, utilizing the technique of "time share scanning" in which the image projected onto the viewing area has discrete pixels or lines and wherein different elements of the image are projected to different sections of the viewing area at different time segments.
Claim 44
Dependent Claim
56 words
The electronic image projection system of Claim 1, further comprising additional light valves, wherein the light valves modulate light which is subsequently projected onto the viewing area, wherein presentation of data from the multiplicity of light valves on the viewing area creates a higher resolution image than would be displayed without the multiplicity of light valves.
Claim 45
Dependent Claim
78 words
The electronic image projection system of Claim 1, wherein said light valve is a single full color light valve, wherein said light valve is addressed such that each pixel on the light valve corresponds to a different pixel in the actual scene, thereby displaying information about only one color in any one pixel in the scene, instead of utilizing a triad consisting of one red, one green, and one blue pixel to represent each pixel in the scene.
Claim 46
Dependent Claim
27 words
The electronic image projection system of Claim 1, further comprising at least a second light source, wherein at least two of the light sources are used simultaneously.
Claim 47
Dependent Claim
40 words
The electronic image projection system of Claim 1, where he light source is powered by a circuit which contains a triac which cuts out part of the duty cycle of AC current to supply the bulb with the proper voltage.
Claim 48
Dependent Claim
26 words
The electronic image projection system of Claim 1, further comprising 1 wherein multiple condenser paths to transmit light from the light source into the projection system.
Claim 49
Dependent Claim
49 words
The electronic image projection system of Claim 1, further comprising: at least two more light valves, wherein one light valve requires input light of a different polarization than the other light valves in the system; and a half-wave plate to provide that differently polarized light for that light valve.
Claim 50
Dependent Claim
52 words
The electronic image projection system of Claim 1, further comprising: a condensing system to collect light from the light source, said condensing system comprising: a spherical mirror; a condenser lens; and a section of a parabolic mirror surrounding the light source to collimate light which would not pass through the condenser lens.
Claim 51
Dependent Claim
22 words
An electronic image projection system wherein multiple condenser paths are used to transmit light from a light source into the projection system.
Claim 52
Dependent Claim
22 words
An electronic image projection system wherein multiple condenser paths are used to transmit light from a light source into the projection system.
Claim 53
Dependent Claim
66 words
The electronic image projection system of Claim 1, comprising a light source; a light collection system, wherein said collection system comprises: an elliptical reflector around the light source; a condenser lens to collimate light emanating from a second focus of said elliptical reflector and a second lens to capture and collimate light which misses the elliptical reflector and therefore does not pass through the condenser lens.
Claim 54
Dependent Claim
67 words
The electronic image projection of Claim 1, comprising: a light source; a light collection system, said collection system comprising an elliptical reflector around the light source; a condenser lens to collimate light emanating from the second focus of the elliptical reflector and a section of a parabolic mirror to capture and collimate light which misses the elliptical mirror and therefore does not pass through the condenser lens.
Claim 55
Dependent Claim
95 words
The electronic image projection system of Claim 1, further comprising: three light valves, each of which modulates light of a different color; a combiner cube utilized to combine the three colored images produced by the three light valves, said combiner cube having four equilateral triangular prisms whose faces are appropriately coated with dichroic coatings and said light valves all requiring input light of the same polarization; and a halfwave plate after the light valve whose light is to be transmitted through the prism cube to maximize efficiency based on polarization produced by Brewster's angle effects.
Claim 56
Dependent Claim
75 words
The electronic image projection system of Claim 1, further comprising a light collection means, comprising: an elliptical mirror with a light source placed at the first focus of said elliptical mirror; a collimating lens placed at a second focus of the ellipse to focus light originating from the light source which misses the elliptical mirror; and a collimating lens beyond the second focus of the elliptical mirror to collimate light coming from the second focus.
Claim 57
Dependent Claim
125 words
The electronic image projection system of Claim 1, further comprising: a light collection means; said light collection means including an elliptical mirror with the light source placed at the first focus of the elliptical mirror; a focusing lens which gathers light emanating from a second focus of the elliptical mirror and brings it to a third focus; a second elliptical surface to capture light that missed the first elliptical surface, said second elliptical surface curved to bring light that hits it coming from the first focus of the first ellipse to the place in space where the focusing lens comes to a focus; and a collimating lens beyond the third focus to collimate light emanating from the focusing lens and from the second elliptical surface.
Claim 58
Dependent Claim
83 words
The electronic image projection system of Claim 1, comprising: a light source; a light collection means, comprising: a light source; a "Fresnel parabolic reflector," said light source at the focus of the parabola, said Fresnel parabolic reflector: multiple segments of a parabola, side by side forming sawtooth surfaces, some of which acts like a standard parabolic reflector while the diameter of the opening at the end of the Fresnel parabolic reflector can remain much smaller than the diameter of a standard parabolic reflector.
Claim 59
Dependent Claim
91 words
A display system according to Claim 1 comprising a light source and light collection means, said light collection means consisting of a light source and a "Fresnel elliptical reflector" with the light source at the focus of the parabola, said Fresnel elliptical reflector consisting of multiple segments of a parabola side by side forming sawtooth surfaces, some of which acts like a standard elliptical reflector while the diameter of the opening at the end of the Fresnel elliptical reflector can remain much smaller then the diameter of a standard elliptical reflector.
Claim 60
Dependent Claim
40 words
The electronic image projection system of Claim 1, further comprising: a non-imaging concentrator wherein light sent into the concentrator is funneled down to an opening which is smaller than the size of the filament or arc in the light source.
Claim 61
Dependent Claim
71 words
The electronic image projection system of Claim 1, wherein said light valve makes use of polarized light and further comprising: a MacNeill prism to polarize light in the system for use by said light valve; mirrors to rotate the plane of polarization of one of the beams exiting the MacNeill prism by 90 degrees so that its new plane of polarization matches that of the second beam exiting the Macneille prism.
References Cited (Backward Citations)
No citation records indexed.
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