Patent JPS4925126A successfully refreshed from Google Patents.
US5984478A
Expired / Lapsed
US
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Dynamic optical compensation for color sequential projection display
Assignee: International Business Machines Corp
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Filing: 1998-07-29
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Granted: 1999-11-16
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Expires: 2018-07-29
Abstract
Abstract A display for displaying a color image formed of a plurality of color light components is provided, wherein each color light component has a focal length and a magnification. The display has a light source for providing polarized light of a first polarization and a color filter wheel having segments of different color filters for sequentially separating the polarized light into a plurality of different color lights. Also provided is a directing means for directing the different color lights having the first polarization to a light valve and for directing respective color light components of a second polarization transmitted from the light valve towards a screen. A dynamic focus element is provided in the display for adjusting the focal length and/or magnification of each color light component to minimize chromatic variations between the color light components. Lastly, a lens is provided for magnifying and projecting the adjusted color light components onto the screen to produce the color image. In variations of the present invention, the dynamic focus element are various mechanical and electro-optical devices.
Inventors
- 👤 Fuad Elias Doany
- 👤 James Anthony Misewich
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 15:44
CPC Classifications
H; H04; H04N; H04N9/00; H04N9/12; H04N9/31; H04N9/3102; H04N9/3111; H04N9/3114; G; G02; G02B; G02B26/00; G02B26/007; G02B26/008; G02B26/06; G02B27/00; G02B27/28; G02B27/283; G02B2207/00; G02B2207/117
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
143 words
A display for displaying a color image formed of a plurality of color light components, each color light component having a focal length and a magnification, the display comprising: a light source for providing polarized light of a first polarization, a color filter wheel having segments of different color filters for sequentially separating the polarized light into a plurality of different color lights, directing means for directing the different color lights having the first polarization to a light valve and for directing respective color light components of a second polarization transmitted from the light valve towards a screen, a dynamic focus element for adjusting the focal length and/or magnification of each color light component to minimize chromatic variations between the color light components, and a lens for magnifying and projecting the adjusted color light components onto the screen to produce the color image.
Claim 2
Dependent Claim
143 words
A display for displaying a color image formed of a plurality of color light components, each color light component having a focal length and a magnification, the display comprising: a light source for providing polarized light of a first polarization, a color filter wheel having segments of different color filters for sequentially separating the polarized light into a plurality of different color lights, directing means for directing the different color lights having the first polarization to a light valve and for directing respective color light components of a second polarization transmitted from the light valve towards a screen, a dynamic focus element for adjusting the focal length and/or magnification of each color light component to minimize chromatic variations between the color light components, and a lens for magnifying and projecting the adjusted color light components onto the screen to produce the color image.
Claim 3
Dependent Claim
53 words
The display of claim 1, wherein the directing means comprises a polarization beamsplitter cube positioned such that the different color lights of the first polarization are directed towards the light valve, and the transmitted color light components of the second polarization from the light valve are reflected back towards the polarization beamsplitter cube.
Claim 4
Dependent Claim
46 words
The display of claim 1, wherein the directing means comprises first and second polarizing films oriented 90° to one another and sandwiching the light valve, such that only the transmitted color light components of the second polarization from the light valve are transmitted towards the lens.
Claim 5
Dependent Claim
21 words
The display of claim 1, wherein the color filter wheel comprises equally sized segments of red, blue, and green color filters.
Claim 6
Dependent Claim
46 words
The display of claim 1, wherein the dynamic focus element comprises control means for adjusting and controlling the relative position of the light valve and lens with respect to each other wherein a given relative position corresponds to a color segment on the color filter wheel.
Claim 7
Dependent Claim
83 words
The display of claim 5, wherein the control means comprises: a motor rotatably connected to the color filter wheel, a piezo drive stage connected to the light valve and/or lens for adjusting the relative position of the light valve and lens with respect to each other, and a processor for synchronizing the motor and piezo drive stage to achieve the proper adjustment in relative position between the light valve and lens for each of the different color segments on the color filter wheel.
Claim 8
Dependent Claim
83 words
The display of claim 5, wherein the control means comprises: a motor rotatably connected to the color filter wheel, a motor driven stage connected to the light valve and/or lens for adjusting the relative position of the light valve and lens with respect to each other, and a processor for synchronizing the motor and motor driven stage to achieve the proper adjustment in relative position between the light valve and lens for each of the different color segments on the color filter wheel.
Claim 9
Dependent Claim
41 words
The display of claim 1, wherein the dynamic focus element comprises an index modulation means disposed between the directing means and lens for changing the index of refraction of the dynamic focus element for each of the different color light components.
Claim 10
Dependent Claim
78 words
The display of claim 8, wherein the index modulation means comprises: first and second transmissive wedges, arranged such that relative motion between the wedges causes their overall thickness to increase or decrease wherein a given overall thickness corresponds to a color segment on the color filter wheel, and a control means for causing the relative motion between the wedges and for synchronizing the overall thickness of the wedges with the corresponding color segment on the color filter wheel.
Claim 11
Dependent Claim
57 words
The display of claim 9, wherein the first wedge is fixed and the second wedge translates over the first wedge, and wherein the control means comprises a first motor rotatably connected to the color filter wheel, a motor driven stage connected to the second wedge, and a processor for synchronizing the first motor and motor driven stage.
Claim 12
Dependent Claim
60 words
The display of claim 8, wherein the index modulation means comprises: a transmissive thickness wheel having a plurality of segments, each segment having a different thickness and corresponding to a color segment on the color filter wheel, and a control means for synchronizing the color segments on the color filter wheel to the corresponding thickness segment on the thickness wheel.
Claim 13
Dependent Claim
39 words
The display of claim 11, wherein the control means comprises a first motor rotatably connected to the color filter wheel, a second motor rotatably connected to the thickness wheel, and a processor for synchronizing the first and second motors.
Claim 14
Dependent Claim
65 words
The display of claim 8, wherein the index modulation means comprises an electro-optic device in which its index of refraction varies in proportion to an applied potential difference wherein a given potential difference corresponds to a color segment on the color filter wheel, and a control means for synchronizing the amount of applied potential difference with the corresponding color segment on the color filter wheel.
Claim 15
Dependent Claim
69 words
The display of claim 13, wherein the electro-optic device comprises an electro-optic material sandwiched between two transmissive electrodes, and wherein the control means comprises: a motor rotatably connected to the color filter wheel, a power source for applying the potential difference across the two transmissive electrodes, and a processor for synchronizing the amount of applied potential difference from the power source with the motor of the color filter wheel.
Claim 16
Dependent Claim
17 words
The display of claim 1, wherein the directing means and dynamic focus element are of integral construction.
Claim 17
Dependent Claim
88 words
The display of claim 15, wherein the directing means and dynamic focus element comprise a polarizing beamsplitter cube made of an electro-optic material sandwiched between two transmissive electrodes in which the index of refraction of the polarized beamsplitter cube varies in proportion to a potential difference applied between the two electrodes wherein a given potential difference corresponds to a color segment on the color filter wheel, and a control means for synchronizing the amount of applied potential difference with the corresponding color segment on the color filter wheel.
Claim 18
Dependent Claim
55 words
The display of claim 16, wherein the control means comprises: a motor rotatably connected to the color filter wheel, a power source for applying the potential difference across the two transmissive electrodes, and a processor for synchronizing the amount of applied potential difference from the power source with the motor of the color filter wheel.
Claim 19
Dependent Claim
138 words
A display for displaying a color image formed of a plurality of color light components, the display comprising: a light source for providing polarized light of a first polarization, a color filter wheel having segments of different color filters for sequentially separating the polarized light into a plurality of different color lights, directing means for directing the different color lights having the first polarization to a light valve and for directing respective color light components of a second polarization transmitted from the light valve towards a screen, a dynamic optical compensation means disposed between the directing means and the light valve for minimizing any residual polarization transmitted by the light valve for each of the different color lights, and a lens for magnifying and projecting the adjusted color light components onto the screen to produce the color image.
Claim 20
Dependent Claim
138 words
A display for displaying a color image formed of a plurality of color light components, the display comprising: a light source for providing polarized light of a first polarization, a color filter wheel having segments of different color filters for sequentially separating the polarized light into a plurality of different color lights, directing means for directing the different color lights having the first polarization to a light valve and for directing respective color light components of a second polarization transmitted from the light valve towards a screen, a dynamic optical compensation means disposed between the directing means and the light valve for minimizing any residual polarization transmitted by the light valve for each of the different color lights, and a lens for magnifying and projecting the adjusted color light components onto the screen to produce the color image.
Claim 21
Dependent Claim
53 words
The display of claim 18, wherein the directing means comprises a polarization beamsplitter cube positioned such that the different color lights of the first polarization are directed towards the light valve, and the transmitted color light components of the second polarization from the light valve are reflected back towards the polarization beamsplitter cube.
Claim 22
Dependent Claim
46 words
The display of claim 18, wherein the directing means comprises first and second polarizing films oriented 90° to one another and sandwiching the light valve, such that only the transmitted color light components of the second polarization from the light valve are transmitted towards the lens.
Claim 23
Dependent Claim
21 words
The display of claim 18, wherein the color filter wheel comprises equally sized segments of red, blue, and green color filters.
Claim 24
Dependent Claim
72 words
The display of claim 18, wherein the dynamic optical compensation means comprises a polarization retardation wheel having a plurality of waveplate segments corresponding to the color segments of the color filter wheel for minimizing any residual polarization transmitted by the light valve for each of the different color lights, and a control means for synchronizing each segment of the color filter wheel with the corresponding waveplate segment on the polarization retardation wheel.
Claim 25
Dependent Claim
40 words
The display of claim 22, wherein the control means comprises a first motor rotatably connected to the color filter wheel, a second motor rotatably connected to the polarization retardation wheel, and a processor for synchronizing the first and second motors.
Claim 26
Dependent Claim
66 words
The display of claim 18, wherein the dynamic optical compensation means comprises an electro-optic device in which its index of refraction varies in proportion to an applied potential difference wherein a given potential difference corresponds to a color segment on the color filter wheel, and a control means for synchronizing the amount of applied potential difference with the corresponding color segment on the color filter wheel.
Claim 27
Dependent Claim
69 words
The display of claim 24, wherein the electro-optic device comprises an electro-optic material sandwiched between two transmissive electrodes, and wherein the control means comprises: a motor rotatably connected to the color filter wheel, a power source for applying the potential difference across the two transmissive electrodes, and a processor for synchronizing the amount of applied potential difference from the power source with the motor of the color filter wheel.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2002-11-15 | 2003-05-17 | 2003-11-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-11-15 | 2007-05-17 | 2007-11-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-11-15 | 2011-05-17 | 2011-11-16 | $7700.00 | Window Closed / Lapsed |