EP0336351A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Controlled color filter for use in information display applications
Assignee: Honeywell Inc
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Filing: 1989-04-04
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Granted: —
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Expires: 2009-04-04
Abstract
Abstract An electronic color filter system for controlling a picture element color signal includes three filter regions (32, 34, 36) which selectively control spectral components of light transmitted sequentially therethrough. Each filter region has a liquid crystal host material and a dye guest component. The orientation of the liquid crystal host, determined by an electric field applied to the filter material, determines the absorption coefficient of the dye guest component to polarized light. By appropriate selection of the guest dye component and control of the electric fields applied to the host liquid crystal, the transmitted light can have a selected radiation spectrum. The transmitted light of a multiplicity of picture elements can be used to provide a full-color visual image display.
Inventors
- 👤 Louis D. Silverstein
- 👤 Anthony J. Bernot
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-02 14:34
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/1333; G02F1/1347; G02F1/13475; G02F1/1335; G02F1/133524
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
217 words
A color filter for controlling transmission of applied light to provide a selected output color signal characterized by a) a first filter (32) including a1) a first dye material cell (32B) having an absorption coefficient in a first preselected spectral range determined by an electric field strength applied thereto, a2) first electrodes positioned to apply an electric field to said first dye material having an electric field strength determined by a first voltage applied across said first electrodes; b) a second filter (34) including b1) a second dye material cell (34B) having an absorption coefficient in a second preselected spectral range determined by an electric field strength applied thereto. b2) second electrodes positioned to apply an electric field to said first dye material having an electric field strength determined by a second voltage applied across said second electrodes; c) a third filter (36) including c1) a third dye material cell (36B) having an absorption coefficient in a third preselected spectral range determined by an electric field strength applied thereto, c2) third electrodes positioned to apply an electric field to said third dye material having an electric field strength determined by a third voltage applied across said third electrodes; and d) voltage means for providing said first, second and third voltages resulting in said selected output color signal.
Claim 2
Dependent Claim
217 words
A color filter for controlling transmission of applied light to provide a selected output color signal characterized by a) a first filter (32) including a1) a first dye material cell (32B) having an absorption coefficient in a first preselected spectral range determined by an electric field strength applied thereto, a2) first electrodes positioned to apply an electric field to said first dye material having an electric field strength determined by a first voltage applied across said first electrodes; b) a second filter (34) including b1) a second dye material cell (34B) having an absorption coefficient in a second preselected spectral range determined by an electric field strength applied thereto. b2) second electrodes positioned to apply an electric field to said first dye material having an electric field strength determined by a second voltage applied across said second electrodes; c) a third filter (36) including c1) a third dye material cell (36B) having an absorption coefficient in a third preselected spectral range determined by an electric field strength applied thereto, c2) third electrodes positioned to apply an electric field to said third dye material having an electric field strength determined by a third voltage applied across said third electrodes; and d) voltage means for providing said first, second and third voltages resulting in said selected output color signal.
Claim 3
Dependent Claim
27 words
The filter of claim 1, characterized in that said first, second and third dyes (32B, 34B, 36B) include a dichroic guest dye coupled to a liquid crystal.
Claim 4
Dependent Claim
21 words
The filter of claim 1 or 2, characterized by a polarizing element (31) to polarize radiation applied to said color filter.
Claim 5
Dependent Claim
46 words
The filter of one of the preceding claims, characterized in that said color filter (30) includes a multiplicity of sets of aligned first, second and third cells (32, 34, 36); each set of aligned cells controlling transmission of light in a preselected region of said filter.
Claim 6
Dependent Claim
22 words
The filter of claim 4, characterized in that each of said preselected regions is a segment of a segmented display (Fig. 4A).
Claim 7
Dependent Claim
20 words
The filter of claim 4, characterized in that each of said preselected display regions is a pixel region (Fig. 4B).
Claim 8
Dependent Claim
131 words
An electronically controlled color display characterized by a) a broad band source of radiation; and b) color filter means responsive to electronic signals for controlling transmission of light therethrough, said filter means including; at least a first plurality of liquid crystal cells, each of said first liquid crystal cells controlling transmission of light through a selected portion of said color display said liquid crystal cell having a first dye material incorporated therein, each of said first liquid crystal cells having electrodes coupled thereto for applying an electric field across said liquid crystal and first dye material, each said first liquid crystal cells absorbing a first spectral component of said transmitted light by an amount determined by an electric field applied thereto, said first spectral component determined by said first dye material.
Claim 9
Dependent Claim
131 words
An electronically controlled color display characterized by a) a broad band source of radiation; and b) color filter means responsive to electronic signals for controlling transmission of light therethrough, said filter means including; at least a first plurality of liquid crystal cells, each of said first liquid crystal cells controlling transmission of light through a selected portion of said color display said liquid crystal cell having a first dye material incorporated therein, each of said first liquid crystal cells having electrodes coupled thereto for applying an electric field across said liquid crystal and first dye material, each said first liquid crystal cells absorbing a first spectral component of said transmitted light by an amount determined by an electric field applied thereto, said first spectral component determined by said first dye material.
Claim 10
Dependent Claim
60 words
The display of claim 7, characterized by a second plurality of liquid crystal cells with a second dye material incorporated therein, each of said second plurality of liquid crystal cells being aligned with a one of said first plurality of liquid crystal cells, each of said second plurality of liquid crystal cells controlling transmission of a second spectral component therethrough.
Claim 11
Dependent Claim
30 words
The display of claim 8, characterized in that each of said first liquid crystal cells and said aligned second liquid crystal cell is a segment of a segmented color display.
Claim 12
Dependent Claim
30 words
The display of claim 8, characterized in that each of said first liquid crystal cells and said aligned second liquid crystal cell is a pixel of a matrix color display.
Claim 13
Dependent Claim
74 words
The display of claim 8, 9 or 10, characterized by a third plurality of liquid crystal cells with a third dye material incorporated therein, each of said third plurality of liquid crystal cells being aligned with a one of said first plurality of liquid crystal cells and a one of said second plurality of liquid crystal cells, each of said third plurality of liquid crystal cells controlling transmission of a third spectral component therethrough.
Claim 14
Dependent Claim
33 words
The display of claim 11, characterized in that said first spectral component is a yellow component, said second spectral component is a cyan component and said third spectral component is a magenta component.
Claim 15
Dependent Claim
26 words
The filter or display according to one of the preceding claims, characterized in that said liquid crystal material is a positive anisotropic nematic or smectic material.
Claim 16
Dependent Claim
23 words
The display of one of the claims 11 to 13, characterized by means (72) for using transmitted spectral components in a projection display.
Claim 17
Dependent Claim
35 words
The filter or display according to one of the claims 1 to 13, characterized by a polarizer (31, 33, 35) provided at the light incident side in front of each filter cell (32, 34, 36).
Claim 18
Dependent Claim
22 words
The filter or display according to claim 15, characterized in that cell polarizers (31, 33, 35) have the same direction of polarisation.
Claim 19
Independent Claim
133 words
A method for providing an output radiation signal having a predetermined color spectrum characterized by the steps of: a) positioning a first (32), a second (34) and a third (36) liquid crystal filter cell in a manner that an input radiation signal passes through each cell; b) coupling a first, a second and a third dye material (32B, 34B, 36B) to a host liquid crystal in said first, second and third liquid crystal filter cell, each dye having selected spectral absorption properties, a strength of each absorption coefficient determined by a voltage applied to a cell; and c) applying a voltage to each of said liquid crystal filter cells, the magnitude of each of said voltages being determined by spectral components to be removed from said input radiation to obtain said output radiation.
Claim 20
Independent Claim
133 words
A method for providing an output radiation signal having a predetermined color spectrum characterized by the steps of: a) positioning a first (32), a second (34) and a third (36) liquid crystal filter cell in a manner that an input radiation signal passes through each cell; b) coupling a first, a second and a third dye material (32B, 34B, 36B) to a host liquid crystal in said first, second and third liquid crystal filter cell, each dye having selected spectral absorption properties, a strength of each absorption coefficient determined by a voltage applied to a cell; and c) applying a voltage to each of said liquid crystal filter cells, the magnitude of each of said voltages being determined by spectral components to be removed from said input radiation to obtain said output radiation.
Claim 21
Dependent Claim
33 words
18 The method of claim 17, characterized by said coupling step including the step of coupling first, second and third dichroic dye molecules to said first, second and third host liquid crystal molecules.
References Cited (Backward Citations)
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