EP0326323A2
Expired / Lapsed
EP
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Multiple image-forming apparatus
Assignee: Rockwell Collins ElectroMechanical Systems Inc
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Filing: 1989-01-24
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Granted: —
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Expires: 2009-01-24
Abstract
Abstract A head-up display (HUD)/head-down display (HDD) system capable of projecting monochromatic or multicolour images employs cholesteric liquid crystal elements (72,74,80,84,88,92), two-state liquid crystal devices (78,82,86,90), an image source (70), a beam splitter (76), and a combiner (94) to, in sequence, generate HUD and HDD images. The cholesteric liquid crystal elements, together with associated LCDs, act as an image shutter to selectively transmit or block portions of an image to an observer. The switching frequency of the LCD-cholesteric liquid crystal element is above the flicker-fusion frequency, such that both the HUD and HDD displays appear to the observer to be simultaneously and continuously operating.
Inventors
- 👤 Arthur Louis Berman
- 👤 Thomas M Lewis
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-24 03:13
CPC Classifications
G; G09; G09G; G09G3/00; G09G3/001; G09G3/002; G02; G02B; G02B27/00; G02B27/01; G02B5/00; G02B5/30; G02B5/3016; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/1333; G02F1/1335; G02F1/133528; G02F1/1347; G02F1/13471; G09B; G09B9/00; G09B9/02; G09B9/08; G09B9/30; G09B9/32; G09B9/326; G02B27/0101; G02B2027/0118; G02B27/0149; G02B2027/0165; G02F2201/00; G02F2201/34; G02F2201/343
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
120 words
An image forming apparatus for forming a plurality of different images at a plurality of viewing positions using a single image source such that the images appear to be formed simultaneously, characterised by: an image source forming, one at a time, images in a bandwidth around one or more selected primary wavelengths, the images to be written at said plurality of viewing positions; means for directing the images produced by the image source into a plurality of paths; optic means for selectively imparting a predetermined circular polarization to each said image; and cholesteric liquid crystal element means located in each said path for reflecting the image having a first circular polarization while transmitting the image having a second circular polarization.
Claim 2
Dependent Claim
120 words
An image forming apparatus for forming a plurality of different images at a plurality of viewing positions using a single image source such that the images appear to be formed simultaneously, characterised by: an image source forming, one at a time, images in a bandwidth around one or more selected primary wavelengths, the images to be written at said plurality of viewing positions; means for directing the images produced by the image source into a plurality of paths; optic means for selectively imparting a predetermined circular polarization to each said image; and cholesteric liquid crystal element means located in each said path for reflecting the image having a first circular polarization while transmitting the image having a second circular polarization.
Claim 3
Dependent Claim
48 words
An image forming apparatus as claimed in claim 1, wherein said optic means comprises: means for imparting to said images circular polarization of a first rotary sense; and means for selectively converting the rotary sense of said images from said first rotary sense to a second rotary sense.
Claim 4
Dependent Claim
30 words
An image forming apparatus according to claim 2, wherein said means for imparting to said images circular polarization of a first rotary sense comprises cholesteric liquid crystal element means (54).
Claim 5
Dependent Claim
38 words
An image forming apparatus according to claim 2 or 3, wherein said means for selectively converting the rotary sense of said images from said first rotary sense to the second rotary sense comprises a liquid crystal device (56).
Claim 6
Dependent Claim
38 words
An image forming apparatus according to claim 2, 3 or 4, further comprising means (64) in one or more of said image paths for directing an image in said path into the line of sight of an observer.
Claim 7
Dependent Claim
30 words
An image forming apparatus according to claim 2, 3, 4 or 5, further comprising timing means for controlling said selective rotation means (56) in conjunction with said image forming apparatus.
Claim 8
Dependent Claim
123 words
An image forming apparatus as claimed in claim 1, wherein: said image source comprises a multicolour image source (70) forming images within one of a plurality of bandwidths, each bandwidth being centered around a selected primary wavelength; and wherein said optic means comprises: means for imparting to said images circular polarization of a first rotary sense; and means located in each said image path for selectively converting the rotary sense of said images from a first rotary sense to a second rotary sense and from the second rotary sense to the first rotary sense; and wherein said cholesteric liquid crystal element means is reflective to an image in one of said bandwidths having the first rotary sense, and transmissive to all other images.
Claim 9
Dependent Claim
25 words
An image forming apparatus according to claim 7, wherein said means for imparting to said images circular polarization comprises cholesteric liquid crystal element means (72,74).
Claim 10
Dependent Claim
29 words
An image forming apparatus according to claim 7 or 8, wherein said means for selectively converting the rotary sense of said images are liquid crystal element means (72,82; 86,90).
Claim 11
Dependent Claim
38 words
An image forming apparatus according to claim 7, 8 or 9, further comprising means (94) in one or more of said image paths for directing an image in said path into the ine of sight of an observer.
Claim 12
Dependent Claim
29 words
An image forming apparatus according to claim 7, 8, 9 or 10, further comprising timing means for controlling said selective rotation means in conjunction with said image forming apparatus.
Claim 13
Dependent Claim
81 words
An image forming apparatus as claimed in claim 3, wherein said means for selectively converting the rotary sense of said images from said first rotary sense to the second rotary sense comprises a liquid crystal device, and said apparatus further comprises: means in one or more of said image paths for directing an image in said path into the line of sight of an observer; and timing means for controlling said selective converting means in conjunction with said image forming apparatus.
Claim 14
Dependent Claim
71 words
An image forming apparatus as claimed in claim 8, wherein said means for collectively converting the rotary sense of said images are liquid crystal element means, and said apparatus further comprises: means in one or more of said image paths for directing an image in said path into the line of sight of an observer; and timing means for controlling said selective converting means in conjunction with said image forming apparatus.
Claim 15
Independent Claim
111 words
A method for forming distinct images at a plurality of viewing positions utilizing a single image source such that the images appear to be continuously and simultaneously produced, characterised by the steps of: forming an image on an image source; imparting said image with circular polarization of a first rotary sense; directing said image into a plurality of image paths; selectively converting the plant of circular polarization of said image in each image path; selectively transmitting or reflecting said image in each image path based on its circular polarization; and transmitting to an observer said image in one of said image paths while blocking said image in all other image paths.
Claim 16
Independent Claim
111 words
A method for forming distinct images at a plurality of viewing positions utilizing a single image source such that the images appear to be continuously and simultaneously produced, characterised by the steps of: forming an image on an image source; imparting said image with circular polarization of a first rotary sense; directing said image into a plurality of image paths; selectively converting the plant of circular polarization of said image in each image path; selectively transmitting or reflecting said image in each image path based on its circular polarization; and transmitting to an observer said image in one of said image paths while blocking said image in all other image paths.
References Cited (Backward Citations)
No citation records indexed.
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