EP0258927A2
Expired / Lapsed
EP
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Display system
Assignee: Koninklijke Philips NV
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Filing: 1987-08-18
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Granted: —
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Expires: 2007-08-18
Abstract
Abstract The present invention is directed to display systems, useful for projection video and television systems, performing with high efficiency and good color rendition. In these systems, color may be provided, as one example, by various light valves, such as liquid crystal displays, each of which are positioned at equal path distances from an illuminating subsystem, as well as having equal path distances from the light valves to a projection subsystem. This enables optimum illumination of each of the light valves. Various embodiments of arranging the light valves, as well as providing illumination are described.
Inventors
- 👤 Thomas Stewart Mc Kechnie
- 👤 Jill Forer Goldenberg
- 👤 Joshua Daniel Eskin
- 👤 Jeffry Arthur Shimizu
- 👤 Ralph Hampton Bradley, Jr.
- 👤 William Francis Guerinot
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-26 12:26
CPC Classifications
H; H04; H04N; H04N9/00; H04N9/12; H04N9/31; H04N9/3102; H04N9/3105; H04N9/3141; H04N9/315; H04N9/3164
Claims Analysis
Total Claims: 31
Claim 1
Independent Claim
46 words
A display system comprising an illumination subsystem, a modulation subsystem, and a projection subsystem, wherein said modulation subsystem includes at least two transmission light valves having equal path lengths from said illumination substage to said light valves and from said light valves to said projection subsystem.
Claim 2
Dependent Claim
46 words
A display system comprising an illumination subsystem, a modulation subsystem, and a projection subsystem, wherein said modulation subsystem includes at least two transmission light valves having equal path lengths from said illumination substage to said light valves and from said light valves to said projection subsystem.
Claim 3
Dependent Claim
19 words
A display system according to Claim 1, wherein at least three light valves are included in said modulation subsystem.
Claim 4
Dependent Claim
29 words
A display system according to Claim 1 or 2, wherein said illumination subsystem includes an elongated light source having a length in the range of 0.3 to 1.5 inches.
Claim 5
Dependent Claim
21 words
A display system according to Claim 3, wherein said elongated light source has a length of at most about 1.06 inches.
Claim 6
Dependent Claim
18 words
A display system according to Claim 3 or Claim 4, wherein said light source is an elongated arc.
Claim 7
Dependent Claim
57 words
A display system according to claim 1, 2, 3, 4 or 5, wherein said light valves in said modulation subsystem include three transmission liquid crystal displays, a first of said liquid crystal displays modulating red light, a second of said liquid crystal displays modulating green light, and a third of said liquid crystal displays modulating blue light.
Claim 8
Dependent Claim
46 words
A display system according to Claim 6, wherein said modulation subsystem further includes a series of dichroic filters and mirrors for passing the respective light through a respective one of said three liquid crystal displays and for recombining each of said light before said projection subsystem.
Claim 9
Dependent Claim
34 words
A display system according to Claim 7, wherein said liquid crystal displays, said dichroic filters, and said mirrors are interchanged to change entrance and exit locations of said illumination subsystem and said projection subsystem.
Claim 10
Dependent Claim
58 words
A display system according to Claim 8, wherein said dichroic filters and mirrors at an entrance side of said modulation subsystem are arranged parallel to said dichroic filters and mirrors at an exit side of said modulation subsystem, said first, second and third liquid crystal displays being individually arranged between said parallel rows of dichroic filters and mirrors.
Claim 11
Dependent Claim
47 words
A display system according to Claim 7 or 8, wherein said dichroic filters and mirrors are arranged at Brewster's angle to the path of light in said modulation subsystem, and wherein said first, second and third liquid crystal displays are perpendicular to the path of said light.
Claim 12
Dependent Claim
38 words
A display system according to Claim 7, 8, 9 or 10, wherein lens portions of said projection subsystem are inserted into said modulation subsystem, said lens portions being color corrected for respective ones of said liquid crystal displays.
Claim 13
Dependent Claim
21 words
A display system according to Claim 11, wherein two separate lens portions are provided relative to a respective liquid crystal display.
Claim 14
Dependent Claim
43 words
A display system according to Claim 7, 8, 9, 10, 11, or 12, wherein at least one further dichroic filter is inserted into said modulation subsystem, said further filter being rotatable to vary wavelengths of said light passed by said liquid crystal displays.
Claim 15
Dependent Claim
21 words
A display system according to Claim 1, 2 or 6, wherein each of said light valves is tilted from the normal.
Claim 16
Dependent Claim
23 words
A display system according to Claim 14, wherein a prism is provided to eliminate trapezoidal distortion of an image of said light valve.
Claim 17
Dependent Claim
44 words
A display system according to Claim 15, wherein said prism is located adjacent said light valve, said prism having an angle B given by where A is the angle of tilt of said light valve and N is the refractive index of said prism.
Claim 18
Dependent Claim
54 words
A display system according to Claim 15, wherein said prism is located adjacent an image of said light valve, said prism having an angle B given by where A is the angle of tilt of said light valve, N is the refractive index of said prism, and M is the magnification of said image.
Claim 19
Dependent Claim
30 words
A display system according to Claim 1, 2 or 6, wherein said illumination subsystem provides one of critical illumination, Kohler illumination, or a combination of critical illumination and Kohler illumination.
Claim 20
Dependent Claim
65 words
A display system according to Claim 1, 2 or 6, wherein said illumination subsystem includes a light source, at least one reflector means for collecting light not passing to said modulation subsystem, and a condenser lens system for passing light to said modulation subsystem, said at least one reflector means redirecting said light not previously passing to said modulation subsystem to said condenser lens system.
Claim 21
Dependent Claim
70 words
A display system according to Claim 19, wherein said light source includes an inner and an outer envelope with plane mirrors within said outer envelope to direct reflected light to at least one image position adjacent said light source, and wherein said reflector means includes reflectors to collect and redirect light to at least one of said light source or said image position for passage through said condenser lens system.
Claim 22
Dependent Claim
52 words
A display system according to Claim 19, wherein said light source directs light radially in substantially all directions including through said condenser lens system, and wherein said reflector means are provided to redirect light not previously passing through said condenser lens system in a direction for passing through said condenser lens system.
Claim 23
Dependent Claim
69 words
A display system according to Claim 20, wherein said light source has only one envelope with plane mirrors being inside or outside said envelope to direct reflected light to at least one image position adjacent said light source, and wherein said reflector means includes reflectors to collect and redirect light to at least one of said light source or said image position for passage through said condenser lens system.
Claim 24
Dependent Claim
28 words
A display system according to Claim 1, 2 or 6, wherein said illumination subsystem includes at least one metal halide lamp or at least one xenon arc lamp.
Claim 25
Dependent Claim
21 words
A display system according to Claim 23, wherein said illumination subsystem has at least two elongated lamps provided side by side.
Claim 26
Dependent Claim
25 words
A display system according to Claim 23, wherein said illumination subsystem has a single lamp with at least two elongated arcs provided side by side.
Claim 27
Dependent Claim
16 words
A projection TV system provided with a display system according to one of the preceding Claims.
Claim 28
Dependent Claim
19 words
An illumination device for application in a display system according to one of the Claims 19, 20, or 21.
Claim 29
Dependent Claim
43 words
An illumination device for application in a display system comprising a single lamp with at least two arcs for supplying uniform illumination in two dimensions and wherein a condensor lens system images said illumination and reflector means are provided for increasing said illumination.
Claim 30
Dependent Claim
43 words
An illumination device for application in a display system comprising a single lamp with at least two arcs for supplying uniform illumination in two dimensions and wherein a condensor lens system images said illumination and reflector means are provided for increasing said illumination.
Claim 31
Dependent Claim
28 words
An illumination device according to Claim 28, wherein said reflector means directs light between said arcs so that said condensor lens system images twice as many arc images.
References Cited (Backward Citations)
No citation records indexed.
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