Patent US5864374A successfully refreshed from Google Patents.
EP0504813A2
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EP
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Method for projecting an image obtained by using liquid crystal panels and display apparatus for realizing the same
Assignee: Hitachi Ltd
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Filing: 1992-03-17
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Granted: —
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Expires: 2012-03-17
Abstract
Abstract In a projection-type display apparatus using light scattering type liquid crystal devices (15), light from a light source (11) is reflected by a reflecting mirror (12) through a collecting lens (13); reflected light is converted by a lens (16) into a parallel light beam, which is injected into liquid crystal devices (15) disposed on three sides through a dichroic mirror (14), the liquid crystal devices coloring an image in red, green and blue; the image is projected on a screen through again the dichroic mirror (14), the collecting lens (16) and an enlarging lens (17). Further a photodetector (1704) is disposed at a focal point of the collecting lens (16) and a function of adjusting the position of the light source on the basis of a result of this detection is added. <IMAGE>
Inventors
- 👤 Yoshiharu Nagae
- 👤 Yuji Mori
- 👤 Yoshiro Mikami
- 👤 Hideo Sato
- 👤 Minoru Hoshino
- 👤 Kyohei Fukuda
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-10 02:31
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/015; H; H04; H04N; H04N9/00; H04N9/12; H04N9/31; H04N9/3102; H04N9/3105; H04N9/312; H04N9/3141; H04N9/315; H04N9/3155; H04N9/3179; H04N5/00; H04N5/74; H04N5/7416; H04N5/7441
Claims Analysis
Total Claims: 29
Claim 1
Independent Claim
138 words
A projection type display apparatus comprising: optical signal generating means (11, 11a, 12, 13, 14; 15, 16; 201, 202, 204, 205, 207, 208) responsive to a plurality of electric signals, for generating a plurality of optical signals having different spectra corresponding to said plurality of electric signals, respectively; control means (18; 213) responsive to an inputted electric image signal representing an image, for generating the plurality of electric signals to output the generated electric signals to said optical signal generating means and for controlling said optical signal generating means; a combining optical system (14; 210) for visually combining the plurality of optical signals to obtain an optical image signal so as to provide said image; and projecting means (16, 17; 211) for focusing said optical image signal to project an enlarged image of said image on a screen.
Claim 2
Dependent Claim
40 words
A display apparatus according to Claim 1, wherein said optical signal generating means includes a plurality of liquid crystal panels (15-R, 15-G, 15-B) provided in correspondence with said different spectra, the liquid crystal panels being of a light scattering type.
Claim 3
Dependent Claim
35 words
A display apparatus according to Claim 2, wherein each of said liquid crystal panels includes liquid crystal of a polymer-dispersed type having a structure in which nematic liquid crystal is contained in an organic material.
Claim 4
Dependent Claim
24 words
A display apparatus according to Claim 2, wherein each of said liquid crystal panels includes encapsulated nematic liquid crystal contained in an organic material.
Claim 5
Dependent Claim
20 words
A display apparatus according to Claim 2, wherein each of said liquid crystal panels includes smectic A phase liquid crystal.
Claim 6
Dependent Claim
161 words
A display apparatus according to Claim 2, wherein said optical signal generating means comprises: a light source (11, 11a) for emitting light; a first lens (13) for focusing the light from said light source; a reflecting mirror (12) for reflecting the light focused by said first lens; a second lens (16) for converting the light reflected by said reflecting mirror into substantially parallel light; a separating optical system (14) for separating the parallel light from said second lens into a plurality of light components having said different spectra, said separating optical system being identical to said combining optical system; and said plurality of liquid crystal panels (15-R, 15-G, 15-B) of reflecting type provided for said different spectra and responsive to the plurality of electric signals from said control means, for generating the plurality of optical signals to output the same to said combining optical system, by using the plurality of light components having said different spectra from said separating optical system.
Claim 7
Dependent Claim
79 words
A display apparatus according to Claim 6, wherein said projecting means (16, 17) includes: said second lens (16) for focusing the optical image signal from said combining optical system; and a third lens (17) for enlarging and projecting on a screen, said image corresponding to the optical image signal focused by said second lens, an optical axis of the light reflected by said reflecting mirror being different from that of the optical image signal focused by said second lens.
Claim 8
Dependent Claim
152 words
A display apparatus according to Claim 2, wherein said optical signal generating means comprises: a light source (162) for emitting light; a first lens (163) for converting the light emitted by said light source into substantially parallel light; a half mirror (161) for reflecting a part of the parallel light from said first lens; a separating optical system (164) for separating the parallel light part reflected by said half mirror into a plurality of light components having said different spectra, said separating optical system being said combining optical system; and said plurality of liquid crystal panels (165-R, 165-G, 165-B) of a reflecting type, provided for said different spectra, and responsive to the plurality of electric signals from said control means, for generating the plurality of optical signals to output the same to said combining optical system, by using the plurality of light components having said different spectra from said separating optical system.
Claim 9
Dependent Claim
164 words
A display apparatus according to Claim 2, wherein each of said liquid crystal panels comprises: a silicon layer (60) provided a circuit, which includes a transistor (63) disposed for each of a plurality of pixels of said each liquid crystal panel, for driving said each liquid crystal panel; a pixel electrode (64) disposed for each pixel on said silicon layer, connected to a source of said corresponding transistor, and functioning to reflect the light component from said separating optical system having the spectrum corresponding to said each liquid crystal panel; a light-scattering-type liquid crystal layer (61) disposed on said pixel electrode and said a silicon layer; a transparent electrode (65) disposed on said liquid crystal layer for transmitting the light component from said separating optical system and reflected light from said pixel electrode as the optical signal; and a glass layer (62) disposed on said transparent electrode, for transmitting the light from said separating optical system and the reflected light from said pixel electrode.
Claim 10
Dependent Claim
37 words
A display apparatus according to Claim 9, wherein a normal to a surface of said glass layer opposite to said transparent electrode is not coincident with an optical axis of the light from said separating optical system.
Claim 11
Dependent Claim
157 words
A display apparatus according to Claim 2, wherein each of said liquid crystal panels includes: a power supply section (V(on), V(off)) for supplying a display voltage to each of marix-like pixels of said each liquid crystal panel; a driving circuit (71) for selectively driving each of rows of the pixels; a supply circuit (72) for receiving the corresponding electric signal and selectively driving each of columns of the pixels in accordance with the corresponding electric signal; and a switching element (111) disposed for each of the pixels, for selectively supplying the display voltage to the pixel in accordance with the drives by the driving circuit and the supply circuit, a first control terminal of said switching element being connected to said driving circuit, a second control terminal being connected to said supply circuit, an output terminal being connected to the pixel, and other terminals being connected to the power supply section so that the pixel is driven.
Claim 12
Dependent Claim
99 words
A display apparatus according to Claim 2, wherein each of said liquid crystal panels includes: a driving circuit (71) for generating row signals to selectively drive each of rows of matrix-like pixels of said each liquid crystal panel; a supply circuit (72) for selectively generating column signals to drive each of columns of the pixels in response to the corresponding electric signal inputted thereto; and a sample hold circuit (S/H) disposed for each of the pixels, for sampling and holding the corresponding column signal from said supply circuit in response to the corresponding row signal from said driving circuit.
Claim 13
Dependent Claim
73 words
A display apparatus according to Claim 9, wherein said circuit for driving said each liquid crystal panel includes: a matrix driving circuit (132) for driving a plurality of pixels disposed in a matrix form in said each liquid crystal panel; a frame memory (133) for storing display information for one image; and a control circuit (134) for controlling said matrix driving circuit in accordance with the display information stored in said frame memory.
Claim 14
Dependent Claim
51 words
A display apparatus according to Claim 2, wherein said combining optical system (14) includes a dichroic prims (141), which is electrically connected with each of said liquid crystal panels including a monocrystal silicon substance (142) through solder bumps and with an external circuit by a flexible flat cable through solder bumps.
Claim 15
Dependent Claim
59 words
A display apparatus according to Claim 7, further comprising: a photodetector (1704) for detecting a light amount; and Photodetector driving means (1705, 1706) for moving said photodetector to a focal point of said second lens in exchanging said light source such that a position of said light source can be adjusted based on a detecting result by said photodetector.
Claim 16
Dependent Claim
96 words
A display apparatus according to Claim 15, wherein said adjusting means (1705) further includes: light source driving means (1702) for moving said light source; and adjusting means (1703) for storing previously an optimum light amount region for every kind of lamps used as said light source and driving said light source driving means in accordance with the optimum light amount region and the detected light amount by said photodetector so that the light amount detected by said detector is in said optimum light amount region for the kind of the lamp used as said light source.
Claim 17
Dependent Claim
72 words
A display apparatus according to Claim 1, wherein said optical signal generating means comprises: a plurality of cathode ray tubes (202, 205, 208) for generating a plurality of light components having the different spectra, respectively; and a plurality of liquid crystal panels (201, 204, 207) for selectively allowing the plurality of light components to pass therethrough in accordance with the plurality of electric signals to generate the plurality of optical signals, respectively.
Claim 18
Dependent Claim
35 words
A display apparatus according to Claim 17, wherein each of said cathode ray tubes (202, 205, 208) has an interference film (301, 302, 303) suitable to the light component emitted thereby on a surface thereof.
Claim 19
Dependent Claim
35 words
A display apparatus according to Claim 2, wherein a beam diameter of each of said cathode ray tubes (202, 205, 208) is greater than that of each of pixels of said each cathode ray tube.
Claim 20
Dependent Claim
86 words
A display apparatus according to Claim 1, wherein said optical signal generating means comprises a plurality of cathode ray tubes (202, 205, 208) for generating a plurality of light signals having the different spectra according to a plurality of electric signals and said combining optical means comprises a light combining section (201) for transmitting or reflecting a light signal from each of said plurality of cathode ray tubes and a liquid crystal section (401), which transmits a plurality of light signals in an order previously determined.
Claim 21
Dependent Claim
35 words
A display apparatus according to Claim 20, wherein each of said cathode ray tubes (202, 205, 208) has an interference film (301, 302, 303) suitable to the light component emitted thereby on a surface thereof.
Claim 22
Dependent Claim
35 words
A display apparatus according to Claim 20, wherein a beam diameter of each of said cathode ray tubes (202, 205, 208) is greater than that of each of pixels of said each cathode ray tube.
Claim 23
Dependent Claim
230 words
A display apparatus according to Claim 2, wherein said optical signal generating means comprises: a half mirror (161) for transmitting about a half of a substantially parallel incident light and reflecting a remaining half; a separating optical system (164 and 164') for separating each of the transmitted light and the reflected light from said half mirror into a plurality of light components having the different spectra, said separating optical system being identical to said combining optical system; and said plurality of liquid crystal panels of a reflecting type, disposed for the different spectra for each of the transmitted light and the reflected light, for generating and outputting to said synthesizing optical means, the plurality of light signals in response to the plurality of electric signals from said control means, respectively, and wherein one of the transmitted light and the reflected light corresponds to electric signals for odd scanning lines among electric image signals, while the other corresponds to electric signals for even scanning lines, said combining optical system synthesizes an even scanning line optical image signal and an odd scanning line optical image signal from the plurality of light signals by use of said separating optical system separately for each of the transmitted light and the reflected light, and synthesizes the optical image signal from said odd and even scanning line optical image signals by use of said half mirror.
Claim 24
Dependent Claim
50 words
A display apparatus according to Claim 6, wherein said reflecting mirror (12) is provided to have a reflecting surface taking 45 degrees with respect to an optical axis of said second lens (16) and an incident angle from said first lens to said reflecting mirror is more than 45 degrees.
Claim 25
Independent Claim
97 words
A method for projecting an enlarged image on a screen comprising the steps of: separating an electric image signal representing the image into a plurality of electric color image signals corresponding different spectra and a sync signal; generating optical signals having the different spectra corresponding to the electric color image signals by using the plurality of electric color image signals and the sync signal; synthesizing an optical image signal from the optical signals by using a synthesizing optical system so as to provide visually said image; and enlarging and projecting the optical image signal on a screen.
Claim 26
Dependent Claim
112 words
A method according to Claim 25, wherein said step of generating optical signals comprises the steps of: converting a light emitted by a light source into a parallel light by a first lens; separating the parallel light from the first lens into a plurality of light components having the different spectra by a separating optical system, said separating optical system being said synthesizing optical system; and generating the optical signals from the electric color image signals, the sync signal, and the light components having the different spectra by use of liquid crystal panels, said liquid crystal panels being of a reflecting type, disposed for the different spectra, and including light-scattering-type liquid crystal.
Claim 27
Dependent Claim
81 words
A method according to Claim 22, wherein said step of projecting the optical image signal comprises the steps of: collecting the optical image signal from the synthesizing optical system by a first lens; and projecting the image corresponding to the optical image signals collected by said first lens on the screen by using a second lens, an optical axis of the parallel light from said first lens being different from that of the optical image signal from the synthesizing optical system.
Claim 28
Dependent Claim
123 words
A method according to Claim 21, wherein said step of generating optical signals comprises the steps of: generating a substantially parallel light from a light emitted from a light source; reflecting a part of the parallel light beam by a half mirror; separating the reflected light by the half mirror into a plurality of light components having the different spectra by the separating optical system, the separating optical system being identical to said synthesizing optical system; and generating the optical signals from the electric color image signals, the sync signal, and the light components having the different spectra by use of liquid crystal panels, said liquid crystal panels being of a reflecting type, disposed for the different spectra, and including light-scattering-type liquid crystal.
Claim 29
Dependent Claim
111 words
A method according to Claim 21, wherein said step of generating optical signals comprises the steps of: generating a substantially parallel light from a light emitted from a light source; generating a plurality of light components having the different spectra from a plurality of cathode ray tubes in response to the sync signal; and generating the plurality of optical signals by selectively allowing the plurality of light components to pass therethrough by a plurality of liquid crystal panels in accordance with the plurality of electric color image signals and the sync signal, the liquid crystal panels being of a transmitting type, disposed for the different spectra, and including light-scattering-type liquid crystal.
References Cited (Backward Citations)
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