US4391492A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thermally addressed cholesteric-smectic liquid crystal device
Assignee: 3M Co
•
Filing: 1981-04-06
•
Granted: 1983-07-05
•
Expires: 2001-04-06
Abstract
Abstract A visual display device is featured which uses a new thermal addressing technique to provide a dark image upon a lighter background. The display is capable of being multiplexed to a large number of rows. The device comprises a cholesteric-smectic liquid crystal material mixed with a pleochroic dye of high order parameter. When the material experiences a transition from a higher to a lower, smectic thermal phase, two different textures or light states are developed; a transparent state and a light absorbing state. The transparent state is developed by applying a sensitizing voltage to certain portions of the medium. The pleochroic dye absorbs the light passing through the unsensitized portions of medium to provide the dark image. The row electrodes are made diffusely reflective so as to provide a double light pass through the medium to improve contrast.
Inventors
- 👤 Sun Lu
- 👤 David B. Chung
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 03:09
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/132; Y; Y10; Y10S; Y10S359/00; Y10S359/90
Claims Analysis
Total Claims: 147
Claim 1
Independent Claim
145 words
A thermally addressed visual device which provides a dark image against a lighter background comprising: A liquid crystal medium including at least one liquid crystal cholesteric compound mixed with at least one pleochroic dye of high order parameter and having dielectric anisotropy, said medium being thermally sensitive and having a transition between at least two thermal phases, an upper thermal phase being a cholesteric phase and a lower thermal phase being a smectic phase, said medium having two possible light modulating states in said smectic phase, a first light state being normally substantially light absorbing and a second light state being substantially transparent; and means to apply a sensitizing voltage to address portions of said medium to develop said second light transparent state when said medium passes rapidly into said smectic phase, the remaining portions of said medium developing said first substantially light absorbing state.
Claim 2
Dependent Claim
145 words
A thermally addressed visual device which provides a dark image against a lighter background comprising: A liquid crystal medium including at least one liquid crystal cholesteric compound mixed with at least one pleochroic dye of high order parameter and having dielectric anisotropy, said medium being thermally sensitive and having a transition between at least two thermal phases, an upper thermal phase being a cholesteric phase and a lower thermal phase being a smectic phase, said medium having two possible light modulating states in said smectic phase, a first light state being normally substantially light absorbing and a second light state being substantially transparent; and means to apply a sensitizing voltage to address portions of said medium to develop said second light transparent state when said medium passes rapidly into said smectic phase, the remaining portions of said medium developing said first substantially light absorbing state.
Claim 3
Dependent Claim
15 words
The thermally addressed visual device of claim 1, wherein said pleochroic dye is light stable.
Claim 4
Dependent Claim
26 words
The thermally addressed visual device of claim 1, wherein at least one liquid crystal compound comprises a smectic "A" liquid crystal material in said lower phase.
Claim 5
Dependent Claim
18 words
The thermally addressed visual device of claim 1, wherein said liquid crystal medium comprises an alkyl cyano biphenyl.
Claim 6
Dependent Claim
29 words
The thermally addressed visual device of claim 1, wherein said medium passes rapidly through two transitions between isotropic and cholesteric phases, and rapidly between cholesteric and smectic "A" phases.
Claim 7
Dependent Claim
54 words
The thermally addressed visual device of claim 1, wherein said medium passes rapidly through two transitions between isotropic and cholesteric phases, and rapidly between cholesteric and smectic "A" phases, and further comprising means for passing said medium between a lower and an upper phase including at least one heating electrode disposed adjacent said medium.
Claim 8
Dependent Claim
29 words
The thermally addressed visual device of claim 6, wherein said heating electrodes are disposed adjacent said medium and diffusely reflect light passing through said medium back through said medium.
Claim 9
Dependent Claim
34 words
The thermally addressed visual device of claim 1, wherein said means for sensitizing portions of said medium comprises at least one electrode for applying a sensitizing voltage to said addressed portions of said medium.
Claim 10
Dependent Claim
23 words
The thermally addressed visual device of claim 1, wherein said liquid crystal medium comprises a mixture of at least two liquid crystal compounds.
Claim 11
Dependent Claim
176 words
A thermally addressed visual device which provides a dark image against a lighter background, said dark image being observable from the same side as a light source passing light through said device, comprising: a liquid crystal medium including at least one liquid crystal cholesteric compound mixed with at least one coloring agent and having dielectric anisotropy, said medium being thermally sensitive and having a transition between at least two thermal phases, an upper thermal phase being a cholesteric phase and a lower thermal phase being a smectic phase, said medium having two possible light modulating states in said smectic phase, a first light state being normally substantially light absorbing and a second light state being substantially transparent; means disposed adjacent said medium for diffusely reflecting light passing through said medium back through said medium; and means to apply a sensitizing voltage to address portions of said medium to develop said second light transparent state when said medium passes rapidly into said smectic phase, the remaining portions of said medium developing said first substantially light absorbing state.
Claim 12
Dependent Claim
176 words
A thermally addressed visual device which provides a dark image against a lighter background, said dark image being observable from the same side as a light source passing light through said device, comprising: a liquid crystal medium including at least one liquid crystal cholesteric compound mixed with at least one coloring agent and having dielectric anisotropy, said medium being thermally sensitive and having a transition between at least two thermal phases, an upper thermal phase being a cholesteric phase and a lower thermal phase being a smectic phase, said medium having two possible light modulating states in said smectic phase, a first light state being normally substantially light absorbing and a second light state being substantially transparent; means disposed adjacent said medium for diffusely reflecting light passing through said medium back through said medium; and means to apply a sensitizing voltage to address portions of said medium to develop said second light transparent state when said medium passes rapidly into said smectic phase, the remaining portions of said medium developing said first substantially light absorbing state.
Claim 13
Dependent Claim
18 words
The thermally addressed visual device of claim 10, wherein at least one coloring agent comprises a pleochroic dye.
Claim 14
Dependent Claim
17 words
The thermally addressed visual device of claim 11, wherein said pleochroic dye is of high order parameter.
Claim 15
Dependent Claim
15 words
The thermally addressed visual device of claim 11, wherein said pleochroic dye is light stable.
Claim 16
Dependent Claim
26 words
The thermally addressed visual device of claim 10, wherein at least one liquid crystal compound comprises a smectic "A" liquid crystal material in said lower phase.
Claim 17
Dependent Claim
18 words
The thermally addressed visual device of claim 10, wherein said liquid crystal medium comprises an alkyl cyano biphenyl.
Claim 18
Dependent Claim
28 words
The thermally addressed visual device of claim 10, wherein said medium passes rapidly through two transitions between isotropic and cholesteric phases, and between cholesteric and smectic "A" phases.
Claim 19
Dependent Claim
53 words
The thermally addressed visual device of claim 10, wherein said medium passes rapidly through two transitions between isotropic and cholesteric phases, and between cholesteric and smectic "A" phases, and further comprising means for passing said medium between a lower and an upper phase including at least one heating electrode disposed adjacent said medium.
Claim 20
Dependent Claim
29 words
The thermally addressed visual device of claim 17, wherein said heating electrodes are disposed adjacent said medium and diffusely reflect light passing through said medium back through said medium.
Claim 21
Dependent Claim
33 words
The thermally addressed visual device of claim 10, wherein said means for sensitizing portions of said medium comprises at least one electrode for applying a sensitizing voltage to said portions of said medium.
Claim 22
Dependent Claim
24 words
The thermally addressed visual device of claim 10, wherein said means for diffusely reflecting said light comprises at least one light diffusing reflective electrode.
Claim 23
Dependent Claim
33 words
The thermally addressed visual device of claim 10, wherein said means for diffusely reflecting said light and said means for heating said medium are comprised in at least one diffusely reflective heating electrode.
Claim 24
Dependent Claim
23 words
The thermally addressed visual device of claim 10, wherein said liquid crystal medium comprises a mixture of at least two liquid crystal compounds.
Claim 25
Dependent Claim
169 words
A thermally addressed visual device which provides a dark image against a lighter background, comprising: a liquid crystal medium including at least one liquid crystal cholesteric compound mixed with at least one pleochroic dye of high order parameter and having dielectric anisotropy, said medium being thermally sensitive and having a transition between an upper and a lower thermal phase, said upper thermal phase being a cholesteric phase and said lower thermal phase being a smectic phase, said medium having two possible light modulating states in said smectic phase characterized by development of respective light absorbing and homeotropic textures in said medium, said light absorbing texture being normally substantially light absorbing and said homeotropic texture being substantially transparent, and means to apply a sensitizing voltage to address portions of said medium to develop said light transparent texture when said medium passes rapidly into said smectic phase, said unaddressed portions of said medium developing said light absorbing texture wherein said dye absorbs light passing through said unaddressed portions of said medium.
Claim 26
Dependent Claim
169 words
A thermally addressed visual device which provides a dark image against a lighter background, comprising: a liquid crystal medium including at least one liquid crystal cholesteric compound mixed with at least one pleochroic dye of high order parameter and having dielectric anisotropy, said medium being thermally sensitive and having a transition between an upper and a lower thermal phase, said upper thermal phase being a cholesteric phase and said lower thermal phase being a smectic phase, said medium having two possible light modulating states in said smectic phase characterized by development of respective light absorbing and homeotropic textures in said medium, said light absorbing texture being normally substantially light absorbing and said homeotropic texture being substantially transparent, and means to apply a sensitizing voltage to address portions of said medium to develop said light transparent texture when said medium passes rapidly into said smectic phase, said unaddressed portions of said medium developing said light absorbing texture wherein said dye absorbs light passing through said unaddressed portions of said medium.
Claim 27
Dependent Claim
15 words
The thermally addressed visual device of claim 23, wherein said pleochroic dye is light stable.
Claim 28
Dependent Claim
26 words
The thermally addressed visual device of claim 23, wherein at least one liquid crystal compound comprises a smectic "A" liquid crystal material in said lower phase.
Claim 29
Dependent Claim
18 words
The thermally addressed visual device of claim 23, wherein said liquid crystal medium comprises an alkyl cyano biphenyl.
Claim 30
Dependent Claim
29 words
The thermally addressed visual device of claim 23, wherein said medium passes rapidly through two transitions between isotropic and cholesteric phases, and rapidly between cholesteric and smectic "A" phases.
Claim 31
Dependent Claim
54 words
The thermally addressed visual device of claim 23, wherein said medium passes rapidly through two transitions between isotropic and cholesteric phases, and rapidly between cholesteric and smectic "A" phases, and further comprising means for passing said medium between a lower and an upper phase including at least one heating electrode disposed adjacent said medium.
Claim 32
Dependent Claim
34 words
The thermally addressed visual device of claim 23, wherein said means for sensitizing portions of said medium comprises at least one electrode for applying a sensitizing voltage to said addressed portions of said medium.
Claim 33
Dependent Claim
29 words
The thermally addressed visual device of claim 23, wherein said heating electrodes are disposed adjacent said medium and diffusely reflect light passing through said medium back through said medium.
Claim 34
Dependent Claim
23 words
The thermally addressed visual device of claim 23, wherein said liquid crystal medium comprises a mixture of at least two liquid crystal compounds.
Claim 35
Dependent Claim
182 words
A thermally addressed visual device which provides a dark image against a lighter background, comprising: a liquid crystal medium including at least one liquid crystal cholesteric compound mixed with at least one coloring agent and having dielectric anisotropy, said medium being thermally sensitive and having a transition between an upper and a lower thermal phase, said upper thermal phase being a cholesteric phase and said lower thermal phase being a smectic phase, said medium having two possible light modulating states in said smectic phase, characterized by development of respective light absorbing and homeotropic textures in said medium, said light absorbing texture being normally substantially light absorbing and said homeotropic texture being substantially transparent; means disposed adjacent said medium for diffusely reflecting light passing through said medium back through said medium; and means to apply a sensitizing voltage to address portions of said medium to develop said homeotropic texture when said medium passes rapidly into said smectic phase, said unaddressed portions of said medium developing said light absorbing texture wherein said coloring agent absorbs light passing through said unaddressed portions of said medium.
Claim 36
Dependent Claim
182 words
A thermally addressed visual device which provides a dark image against a lighter background, comprising: a liquid crystal medium including at least one liquid crystal cholesteric compound mixed with at least one coloring agent and having dielectric anisotropy, said medium being thermally sensitive and having a transition between an upper and a lower thermal phase, said upper thermal phase being a cholesteric phase and said lower thermal phase being a smectic phase, said medium having two possible light modulating states in said smectic phase, characterized by development of respective light absorbing and homeotropic textures in said medium, said light absorbing texture being normally substantially light absorbing and said homeotropic texture being substantially transparent; means disposed adjacent said medium for diffusely reflecting light passing through said medium back through said medium; and means to apply a sensitizing voltage to address portions of said medium to develop said homeotropic texture when said medium passes rapidly into said smectic phase, said unaddressed portions of said medium developing said light absorbing texture wherein said coloring agent absorbs light passing through said unaddressed portions of said medium.
Claim 37
Dependent Claim
18 words
The thermally addressed visual device of claim 32, wherein at least one coloring agent comprises a pleochroic dye.
Claim 38
Dependent Claim
17 words
The thermally addressed visual device of claim 33, wherein said pleochroic dye is of high order parameter.
Claim 39
Dependent Claim
15 words
The thermally addressed visual device of claim 33, wherein said pleochroic dye is light stable.
Claim 40
Dependent Claim
26 words
The thermally addressed visual device of claim 32, wherein at least one liquid crystal compound comprises a smectic "A" liquid crystal material in said lower phase.
Claim 41
Dependent Claim
18 words
The thermally addressed visual device of claim 32, wherein said liquid crystal medium comprises an alkyl cyano biphenyl.
Claim 42
Dependent Claim
29 words
The thermally addressed visual device of claim 32, wherein said medium passes rapidly through two transitions between isotropic and cholesteric phases, and rapidly between cholesteric and smectic "A" phases.
Claim 43
Dependent Claim
54 words
The thermally addressed visual device of claim 32, wherein said medium passes rapidly through two transitions between isotropic and cholesteric phases, and rapidly between cholesteric and smectic "A" phases, and further comprising means for passing said medium between a lower and an upper phase including at least one heating electrode disposed adjacent said medium.
Claim 44
Dependent Claim
29 words
The thermally addressed visual device of claim 39, wherein said heating electrodes are disposed adjacent said medium and diffusely reflect light passing through said medium back through said medium.
Claim 45
Dependent Claim
33 words
The thermally addressed visual device of claim 32, wherein said means for sensitizing portions of said medium comprises at least one electrode for applying a sensitizing voltage to said portions of said medium.
Claim 46
Dependent Claim
24 words
The thermally addressed visual device of claim 32, wherein said means for diffusely reflecting said light comprises at least one light diffusing reflective electrode.
Claim 47
Dependent Claim
33 words
The thermally addressed visual device of claim 32, wherein said means for diffusely reflecting said light and said means for heating said medium are comprised in at least one diffusely reflective heating electrode.
Claim 48
Dependent Claim
23 words
The thermally addressed visual device of claim 32, wherein said liquid crystal medium comprises a mixture of at least two liquid crystal compounds.
Claim 49
Dependent Claim
201 words
A thermally addressed visual device which provides a dark image against a lighter background, said dark image being observable from the same side as a light source passing light through said device, comprising: a liquid crystal medium including at least one liquid crystal cholesteric compound mixed with at least one pleochroic dye of high order parameter and having dielectric anisotropy, said medium being thermally sensitive and having a transition between an upper and a lower thermal phase, said upper thermal phase being a cholesteric phase and said lower thermal phase being a smectic phase, said medium having two possible light modulating states in said smectic phase, characterized by development of respective light absorbing and heomeotropic textures in said medium, said light absorbing texture being normally substantially light absorbing and said homeotropic texture being substantially transparent; means for passing said medium through said transition between said upper and said lower phase; and means to apply a sensitizing voltage to address portions of said medium to develop said homeotropic texture when said medium passes rapidly into said smectic phase, said unaddressed portions of said medium developing said light absorbing texture wherein said dye absorbs light passing through said unaddressed portions of said medium.
Claim 50
Dependent Claim
201 words
A thermally addressed visual device which provides a dark image against a lighter background, said dark image being observable from the same side as a light source passing light through said device, comprising: a liquid crystal medium including at least one liquid crystal cholesteric compound mixed with at least one pleochroic dye of high order parameter and having dielectric anisotropy, said medium being thermally sensitive and having a transition between an upper and a lower thermal phase, said upper thermal phase being a cholesteric phase and said lower thermal phase being a smectic phase, said medium having two possible light modulating states in said smectic phase, characterized by development of respective light absorbing and heomeotropic textures in said medium, said light absorbing texture being normally substantially light absorbing and said homeotropic texture being substantially transparent; means for passing said medium through said transition between said upper and said lower phase; and means to apply a sensitizing voltage to address portions of said medium to develop said homeotropic texture when said medium passes rapidly into said smectic phase, said unaddressed portions of said medium developing said light absorbing texture wherein said dye absorbs light passing through said unaddressed portions of said medium.
Claim 51
Dependent Claim
15 words
The thermally addressed visual device of claim 45, wherein said pleochroic dye is light stable.
Claim 52
Dependent Claim
26 words
The thermally addressed visual device of claim 45, wherein at least one liquid crystal compound comprises a smectic "A" liquid crystal material in said lower phase.
Claim 53
Dependent Claim
18 words
The thermal addressed visual device of claim 45, wherein said liquid crystal medium comprises an alkyl cyano biphenyl.
Claim 54
Dependent Claim
29 words
The thermally addressed visual device of claim 45, wherein said medium passes rapidly through two transitions between isotropic and cholesteric phases, and rapidly between cholesteric and smectic "A" phases.
Claim 55
Dependent Claim
53 words
The thermally addressed visual device of claim 45, wherein said medium passes rapidly through two transitions between isotropic and cholesteric phases, and rapidly between cholesteric and smectic "A" phases, and said means for passing said medium between a lower and an upper phase comprises at least one heating electrode disposed adjacent said medium.
Claim 56
Dependent Claim
29 words
The thermally addressed visual device of claim 50, wherein said heating electrodes are disposed adjacent said medium and diffusely reflect light passing through said medium back through said medium.
Claim 57
Dependent Claim
34 words
The thermally addressed visual device of claim 45, wherein said means for sensitizing portions of said medium comprises at least one electrode for applying a sensitizing voltage to said addressed portions of said medium.
Claim 58
Dependent Claim
23 words
The thermally addressed visual device of claim 45, wherein said liquid crystal medium comprises a mixture of at least two liquid crystal compounds.
Claim 59
Dependent Claim
24 words
The thermally addressed visual device of claim 45, wherein said means for passing said medium through said thermal transition comprises at least one electrode.
Claim 60
Dependent Claim
201 words
A thermally addressed visual device which provides a dark image against a lighter background, said dark image being observable from the same side as a light source passing light through said device, comprising: A liquid crystal medium including at least one liquid crystal cholesteric compound mixed with at least one coloring agent and having dielectric anisotropy, said medium being thermally sensitive and having a transition between an upper and a lower thermal phase, said upper thermal phase being a cholesteric phase and said lower thermal phase being a smectic phase, said medium having two possible light modulating states in said smectic phase characterized by development of respective light absorbing and homeotropic textures in said medium, said light absorbing texture being normally substantially light absorbing and said homeotropic texture being substantially transparent; means disposed adjacent said medium for diffusely reflecting light passing through said medium back through said medium; and means to apply a sensitizing voltage to address portions of said medium to develop said homeotropic texture when said medium passes rapidly into said smectic thermal phase, said unaddressed portions of said medium developing said light absorbing texture wherein said coloring agent absorbs light passing through said unaddressed portions of said medium.
Claim 61
Dependent Claim
201 words
A thermally addressed visual device which provides a dark image against a lighter background, said dark image being observable from the same side as a light source passing light through said device, comprising: A liquid crystal medium including at least one liquid crystal cholesteric compound mixed with at least one coloring agent and having dielectric anisotropy, said medium being thermally sensitive and having a transition between an upper and a lower thermal phase, said upper thermal phase being a cholesteric phase and said lower thermal phase being a smectic phase, said medium having two possible light modulating states in said smectic phase characterized by development of respective light absorbing and homeotropic textures in said medium, said light absorbing texture being normally substantially light absorbing and said homeotropic texture being substantially transparent; means disposed adjacent said medium for diffusely reflecting light passing through said medium back through said medium; and means to apply a sensitizing voltage to address portions of said medium to develop said homeotropic texture when said medium passes rapidly into said smectic thermal phase, said unaddressed portions of said medium developing said light absorbing texture wherein said coloring agent absorbs light passing through said unaddressed portions of said medium.
Claim 62
Dependent Claim
18 words
The thermally addressed visual device of claim 55, wherein at least one coloring agent comprises a pleochroic dye.
Claim 63
Dependent Claim
17 words
The thermally addressed visual device of claim 56, wherein said pleochroic dye is of high order, parameter.
Claim 64
Dependent Claim
15 words
The thermally addressed visual device of claim 56, wherein said pleochroic dye is light stable.
Claim 65
Dependent Claim
26 words
The thermally addressed visual device of claim 55, wherein at least one liquid crystal compound comprises a smectic "A" liquid crystal material in said lower phase.
Claim 66
Dependent Claim
18 words
The thermally addressed visual device of claim 55, wherein said liquid crystal medium comprises an alkyl cyano biphenyl.
Claim 67
Dependent Claim
29 words
The thermally addressed visual device of claim 55, wherein said medium passes rapidly through two transitions between isotropic and cholesteric phases, and rapidly between cholesteric and smectic "A" phases.
Claim 68
Dependent Claim
54 words
The thermally addressed visual device of claim 55, wherein said medium passes rapidly through two transitions between isotropic and cholesteric phases, and rapidly between cholesteric and smectic "A" phases, and further comprising means for passing said medium between a lower and an upper phase including at least one heating electrode disposed adjacent said medium.
Claim 69
Dependent Claim
29 words
The thermally addressed visual device of claim 62, wherein said heating electrodes are disposed adjacent said medium and diffusely reflect light passing through said medium back through said medium.
Claim 70
Dependent Claim
34 words
The thermally addressed visual device of claim 55, wherein said means for sensitizing portions of said medium comprises at least one electrode for applying a sensitizing voltage to said addressed portions of said medium.
Claim 71
Dependent Claim
24 words
The thermally addressed visual device of claim 55, wherein said means for diffusely reflecting said light comprises at least one light diffusing reflective electrode.
Claim 72
Dependent Claim
33 words
The thermally addressed visual device of claim 55, wherein said means for diffusely reflecting said light and said means for heating said medium are comprised in at least one diffusely reflective heating electrode.
Claim 73
Dependent Claim
23 words
The thermally addressed visual device of claim 55, wherein said liquid crystal medium comprises a mixture of at least two liquid crystal compounds.
Claim 74
Dependent Claim
215 words
A thermally addressed visual device which provides a dark image against a lighter background, said dark image being observable from the same side as a light source passing light through said device, comprising: a liquid crystal medium including at least one liquid crystal cholesteric compound mixed with at least one coloring agent and having dielectric anisotropy, said medium being thermally sensitive and having a transition between an upper and a lower thermal phase, said upper thermal phase being a cholesteric phase and said lower thermal phase being a smectic phase, said medium having two possible light modulating states in said smectic phase, characterized by development of respective light absorbing and homeotropic textures in said medium, said light absorbing texture being normally substantially light absorbing and said homeotropic texture being substantially transparent; means for passing said medium through said transition between said cholesteric and said smectic phase; means disposed adjacent said medium for diffusely reflecting light passing through said medium back through said medium; and means to apply a sensitizing voltage to address portions of said medium to develop said homeotropic texture when said medium passes rapidly into said smectic phase, said unaddressed portions of said medium developing said light absorbing texture wherein said coloring agent absorbs light passing through said unaddressed portions of said medium.
Claim 75
Dependent Claim
215 words
A thermally addressed visual device which provides a dark image against a lighter background, said dark image being observable from the same side as a light source passing light through said device, comprising: a liquid crystal medium including at least one liquid crystal cholesteric compound mixed with at least one coloring agent and having dielectric anisotropy, said medium being thermally sensitive and having a transition between an upper and a lower thermal phase, said upper thermal phase being a cholesteric phase and said lower thermal phase being a smectic phase, said medium having two possible light modulating states in said smectic phase, characterized by development of respective light absorbing and homeotropic textures in said medium, said light absorbing texture being normally substantially light absorbing and said homeotropic texture being substantially transparent; means for passing said medium through said transition between said cholesteric and said smectic phase; means disposed adjacent said medium for diffusely reflecting light passing through said medium back through said medium; and means to apply a sensitizing voltage to address portions of said medium to develop said homeotropic texture when said medium passes rapidly into said smectic phase, said unaddressed portions of said medium developing said light absorbing texture wherein said coloring agent absorbs light passing through said unaddressed portions of said medium.
Claim 76
Dependent Claim
18 words
The thermally addressed visual device of claim 68, wherein at least one coloring agent comprises a pleochroic dye.
Claim 77
Dependent Claim
17 words
The thermally addressed visual device of claim 69, wherein said pleochroic dye is of high order, parameter.
Claim 78
Dependent Claim
15 words
The thermally addressed visual device of claim 69, wherein said pleochroic dye is light stable.
Claim 79
Dependent Claim
26 words
The thermally addressed visual device of claim 68, wherein at least one liquid crystal compound comprises a smectic "A" liquid crystal material in said lower phase.
Claim 80
Dependent Claim
18 words
The thermally addressed visual device of claim 68, wherein said liquid crystal medium comprises an alkyl cyano biphenyl.
Claim 81
Dependent Claim
29 words
The thermally addressed visual device of claim 68, wherein said medium passes rapidly through two transitions between isotropic and cholesteric phases, and rapidly between cholesteric and smectic "A" phases.
Claim 82
Dependent Claim
53 words
The thermally addressed visual device of claim 68, wherein said medium passes rapidly through two transitions between isotropic and cholesteric phases, and rapidly between cholesteric and smectic "A" phases, and said means for passing said medium between an upper and a lower phase comprises at least one heating electrode disposed adjacent said medium.
Claim 83
Dependent Claim
29 words
The thermally addressed visual device of claim 75, wherein said heating electrodes are disposed adjacent said medium and diffusely reflect light passing through said medium back through said medium.
Claim 84
Dependent Claim
33 words
The thermally addressed visual device of claim 68, wherein said means for sensitizing portions of said medium comprises at least one electrode for applying a sensitizing voltage to said portions of said medium.
Claim 85
Dependent Claim
24 words
The thermally addressed visual device of claim 68, wherein said means for diffusely reflecting said light comprises at least one light diffusing reflective electrode.
Claim 86
Dependent Claim
33 words
The thermally addressed visual device of claim 68, wherein said means for diffusely reflecting said light and said means for heating said medium are comprised in at least one diffusely reflective heating electrode.
Claim 87
Dependent Claim
23 words
The thermally addressed visual device of claim 68, wherein said liquid crystal medium comprises a mixture of at least two liquid crystal compounds.
Claim 88
Dependent Claim
24 words
The thermally addressed visual device of claim 68, wherein said means for passing said medium through said thermal transition comprises at least one electrode.
Claim 89
Dependent Claim
244 words
A thermally addressed, multiplexed, visual device which provides a dark image against a lighter background, said dark image being observable from the same side as a light source passing light through said device, comprising: a liquid crystal medium including at least one liquid crystal cholesteric compound mixed with at least one coloring agent and having dielectric anisotropy, said medium being thermally sensitive and having a transition between an upper and a lower thermal phase, said upper thermal phase being a cholesteric phase and said lower thermal phase being a smectic phase, said medium having two possible light modulating states in said smectic phase, characterized by development of respective homeotropic and light absorbing textures in said medium, a first light state being normally substantially light absorbing and a second light state being substantially transparent; means for passing said medium through said transition between said cholesteric and said smectic phase; means disposed adjacent said medium for diffusely reflecting light passing through said medium back through said medium; and means to sequentially apply sensitizing voltages to address portions of said medium to develop said second substantially light transparent state when said medium passes rapidly into said smectic phase, said medium developing said homeotropic texture in said addressed portions, the remaining unaddressed portions of said medium developing said first substantially light absorbing state, said unaddressed portions of said medium developing said light absorbing texture wherein said coloring agent absorbs light passing through said unaddressed portions of said medium.
Claim 90
Dependent Claim
244 words
A thermally addressed, multiplexed, visual device which provides a dark image against a lighter background, said dark image being observable from the same side as a light source passing light through said device, comprising: a liquid crystal medium including at least one liquid crystal cholesteric compound mixed with at least one coloring agent and having dielectric anisotropy, said medium being thermally sensitive and having a transition between an upper and a lower thermal phase, said upper thermal phase being a cholesteric phase and said lower thermal phase being a smectic phase, said medium having two possible light modulating states in said smectic phase, characterized by development of respective homeotropic and light absorbing textures in said medium, a first light state being normally substantially light absorbing and a second light state being substantially transparent; means for passing said medium through said transition between said cholesteric and said smectic phase; means disposed adjacent said medium for diffusely reflecting light passing through said medium back through said medium; and means to sequentially apply sensitizing voltages to address portions of said medium to develop said second substantially light transparent state when said medium passes rapidly into said smectic phase, said medium developing said homeotropic texture in said addressed portions, the remaining unaddressed portions of said medium developing said first substantially light absorbing state, said unaddressed portions of said medium developing said light absorbing texture wherein said coloring agent absorbs light passing through said unaddressed portions of said medium.
Claim 91
Dependent Claim
18 words
The thermally addressed visual device of claim 82, wherein at least one coloring agent comprises a pleochroic dye.
Claim 92
Dependent Claim
17 words
The thermally addressed visual device of claim 83, wherein said pleochroic dye is of high order, parameter.
Claim 93
Dependent Claim
15 words
The thermally addressed visual device of claim 83, wherein said pleochoric dye is light stable.
Claim 94
Dependent Claim
26 words
The thermally addressed visual device of claim 82, wherein at least one liquid crystal compound comprises a smectic "A" liquid crystal material in said lower phase.
Claim 95
Dependent Claim
18 words
The thermally addressed visual device of claim 82, wherein said liquid crystal medium comprises an alkyl cyano biphenyl.
Claim 96
Dependent Claim
29 words
The thermally addressed visual device of claim 82, wherein said medium passes rapidly through two transitions between isotropic and cholesteric phases, and rapidly between cholesteric and smectic "A" phases.
Claim 97
Dependent Claim
53 words
The thermally addressed visual device of claim 82, wherein said medium passes rapidly through two transitions between isotropic and cholesteric phases, and rapidly between cholesteric and smectic "A" phases, and said means for passing said medium between a lower and an upper phase comprises at least one heating electrode disposed adjacent said medium.
Claim 98
Dependent Claim
29 words
The thermally addressed visual device of claim 89, wherein said heating electrodes are disposed adjacent said medium and diffusely reflect light passing through said medium back through said medium.
Claim 99
Dependent Claim
33 words
The thermally addressed visual device of claim 82, wherein said means for sensitizing portions of said medium comprises at least one electrode for applying a sensitizing voltage to said portions of said medium.
Claim 100
Dependent Claim
24 words
The thermally addressed visual device of claim 82, wherein said means for diffusely reflecting said light comprises at least one light diffusing reflective electrode.
Claim 101
Dependent Claim
33 words
The thermally addressed visual device of claim 82, wherein said means for diffusely reflecting said light and said means for heating said medium are comprised in at least one diffusely reflective heating electrode.
Claim 102
Dependent Claim
23 words
The thermally addressed visual device of claim 82, wherein said liquid crystal medium comprises a mixture of at least two liquid crystal compounds.
Claim 103
Dependent Claim
24 words
The thermally addressed visual device of claim 82, wherein said means for passing said medium through said thermal transition comprises at least one electrode.
Claim 104
Dependent Claim
202 words
A thermally addressed, multiplexed, visual display device which provides a dark image against a lighter background comprising: A liquid crystal medium including at least one liquid crystal cholesteric compound mixed with at least one pleochoric dye of high order parameter and having dielectric anisotropy, said medium being thermally sensitive and having a transition between at least two thermal phases, said medium having two possible light modulating states in a lower thermal phase, an upper thermal phase being a cholesteric phase and said lower thermal phase being a smectic phase, a first light state being normally substantially light absorbing and a second light state being substantially transparent; and a matrix of electrodes disposed about said medium, a number of said matrix electrodes defining rows and a number of said matrix electrodes defining columns, said row electrodes heating said medium to cause said medium to pass through a thermal transition between said lower and said upper phase, and said column electrodes for applying sequential sensitizing voltages to address portions of said medium to develop said second light transparent state when said medium rapidly cools and passes into said smectic phase, the remaining unaddressed portions of said medium developing said first substantially light absorbing state.
Claim 105
Dependent Claim
202 words
A thermally addressed, multiplexed, visual display device which provides a dark image against a lighter background comprising: A liquid crystal medium including at least one liquid crystal cholesteric compound mixed with at least one pleochoric dye of high order parameter and having dielectric anisotropy, said medium being thermally sensitive and having a transition between at least two thermal phases, said medium having two possible light modulating states in a lower thermal phase, an upper thermal phase being a cholesteric phase and said lower thermal phase being a smectic phase, a first light state being normally substantially light absorbing and a second light state being substantially transparent; and a matrix of electrodes disposed about said medium, a number of said matrix electrodes defining rows and a number of said matrix electrodes defining columns, said row electrodes heating said medium to cause said medium to pass through a thermal transition between said lower and said upper phase, and said column electrodes for applying sequential sensitizing voltages to address portions of said medium to develop said second light transparent state when said medium rapidly cools and passes into said smectic phase, the remaining unaddressed portions of said medium developing said first substantially light absorbing state.
Claim 106
Dependent Claim
15 words
The thermally addressed visual device of claim 96, wherein said pleochroic dye is light stable.
Claim 107
Dependent Claim
26 words
The thermally addressed visual device of claim 96, wherein at least one liquid crystal compound comprises a smectic "A" liquid crystal material in said lower phase.
Claim 108
Dependent Claim
18 words
The thermally addressed visual device of claim 96, wherein said liquid crystal medium comprises an alkyl cyano biphenyl.
Claim 109
Dependent Claim
29 words
The thermally addressed visual device of claim 96, wherein said medium passes rapidly through two transitions between isotropic and cholesteric phases, and rapidly between cholesteric and smectic "A" phases.
Claim 110
Dependent Claim
38 words
The thermally addressed visual device of claim 96, wherein said medium passes rapidly through two transitions between isotropic and cholesteric phases, and rapidly between cholesteric and smectic "A" phases, and wherein said electrodes are disposed adjacent said medium.
Claim 111
Dependent Claim
222 words
A thermally addressed, multiplexed, visual display device providing a dark image against a lighter background, comprising: A liquid crystal medium including at least one liquid crystal cholesteric compound mixed with at least one pleochroic dye of high order parameter and having dielectric anisotropy, said medium being thermally sensitive and having a transistion between at least two thermal phases, said medium having two possible light modulating states in a lower thermal phase, an upper thermal phase being a cholesteric phase and said lower thermal phase being a smectic phase, a first light state being normally substantially light absorbing and a second light state being substantially transparent; and a matrix of electrodes disposed about said medium, a number of said matrix electrodes defining rows and a number of said matrix electrodes defining columns, said column electrodes being substantially at right angles to, and disposed in another plane with respect to said row electrodes, said row electrodes for heating said medium to cause said medium to pass rapidly through a thermal transition between said lower and said upper phase, and said column electrodes for applying sequential sensitizing voltages to address portions of said medium to develop said second light transparent state when said medium cools and passes into said smectic phase, the remaining unaddressed portions of said medium developing said first substantially light absorbing state.
Claim 112
Dependent Claim
222 words
A thermally addressed, multiplexed, visual display device providing a dark image against a lighter background, comprising: A liquid crystal medium including at least one liquid crystal cholesteric compound mixed with at least one pleochroic dye of high order parameter and having dielectric anisotropy, said medium being thermally sensitive and having a transistion between at least two thermal phases, said medium having two possible light modulating states in a lower thermal phase, an upper thermal phase being a cholesteric phase and said lower thermal phase being a smectic phase, a first light state being normally substantially light absorbing and a second light state being substantially transparent; and a matrix of electrodes disposed about said medium, a number of said matrix electrodes defining rows and a number of said matrix electrodes defining columns, said column electrodes being substantially at right angles to, and disposed in another plane with respect to said row electrodes, said row electrodes for heating said medium to cause said medium to pass rapidly through a thermal transition between said lower and said upper phase, and said column electrodes for applying sequential sensitizing voltages to address portions of said medium to develop said second light transparent state when said medium cools and passes into said smectic phase, the remaining unaddressed portions of said medium developing said first substantially light absorbing state.
Claim 113
Dependent Claim
15 words
The thermally addressed visual device of claim 102, wherein said pleochroic dye is light stable.
Claim 114
Dependent Claim
26 words
The thermally addressed visual device of claim 102, wherein at least one liquid crystal compound comprises a smectic "A" liquid crystal material in said lower phase.
Claim 115
Dependent Claim
18 words
The thermally addressed visual device of claim 102, wherein said liquid crystal medium comprises an alkyl cyano biphenyl.
Claim 116
Dependent Claim
29 words
The thermally addressed visual device of claim 102, wherein said medium passes rapidly through two transitions between isotropic and cholesteric phases, and rapidly between cholesteric and smectic "A" phases.
Claim 117
Dependent Claim
38 words
The thermally addressed visual device of claim 102, wherein said medium passes rapidly through two transitions between isotropic and cholesteric phases, and rapidly between cholesteric and smectic "A" phases, and wherein said rows are disposed adjacent said medium.
Claim 118
Dependent Claim
253 words
A thermally addressed, multiplexed, visual display device providing a dark image against a lighter background, said image being observable from the same side as a light source passing light through said device, comprising: A liquid crystal medium including at least one liquid crystal cholesteric compound mixed with at least one coloring agent and having dielectric anisotropy, said medium being thermally sensitive and having a transition between at least two thermal phases, said medium having two possible light modulating states in a lower thermal phase, an upper thermal phase being a cholesteric phase and said lower thermal phase being a smectic phase, a first light state being normally substantially light absorbing and a second light state being substantially transparent; and a matrix of electrodes disposed about said medium, a number of said matrix electrodes defining rows and a number of said matrix electrodes defining columns, said column electrodes being substantially transparent to light passing through said medium, said row electrodes being substantially diffusely reflective for heating said medium to cause said medium to pass through a thermal transistion between said lower and said upper phases, said column electrodes for applying sequential sensitizing voltages to address portions of said medium to develop said second light transparent state when said medium rapidly cools and passes into said smectic phase, the remaining portions of said medium developing said first substantially light absorbing state, said row electrodes being disposed behind said medium and having means to diffusely reflect the light passing through the medium back through said medium.
Claim 119
Dependent Claim
253 words
A thermally addressed, multiplexed, visual display device providing a dark image against a lighter background, said image being observable from the same side as a light source passing light through said device, comprising: A liquid crystal medium including at least one liquid crystal cholesteric compound mixed with at least one coloring agent and having dielectric anisotropy, said medium being thermally sensitive and having a transition between at least two thermal phases, said medium having two possible light modulating states in a lower thermal phase, an upper thermal phase being a cholesteric phase and said lower thermal phase being a smectic phase, a first light state being normally substantially light absorbing and a second light state being substantially transparent; and a matrix of electrodes disposed about said medium, a number of said matrix electrodes defining rows and a number of said matrix electrodes defining columns, said column electrodes being substantially transparent to light passing through said medium, said row electrodes being substantially diffusely reflective for heating said medium to cause said medium to pass through a thermal transistion between said lower and said upper phases, said column electrodes for applying sequential sensitizing voltages to address portions of said medium to develop said second light transparent state when said medium rapidly cools and passes into said smectic phase, the remaining portions of said medium developing said first substantially light absorbing state, said row electrodes being disposed behind said medium and having means to diffusely reflect the light passing through the medium back through said medium.
Claim 120
Dependent Claim
18 words
The thermally addressed visual device of claim 108, wherein at least one coloring agent comprises a pleochroic dye.
Claim 121
Dependent Claim
17 words
The thermally addressed visual device of claim 109, wherein said pleochroic dye is of high order parameter.
Claim 122
Dependent Claim
15 words
The thermally addressed visual device of claim 109, wherein said pleochroic dye is light stable.
Claim 123
Dependent Claim
26 words
The thermally addressed visual device of claim 108, wherein at least one liquid crystal compound comprises a smectic "A" liquid crystal material in said lower phase.
Claim 124
Dependent Claim
18 words
The thermally addressed visual device of claim 108, wherein said liquid crystal medium comprises an alkyl cyano biphenyl.
Claim 125
Dependent Claim
29 words
The thermally addressed visual device of claim 108, wherein said medium passes rapidly through two transitions between isotropic and cholesteric phases, and rapidly between cholesteric and smectic "A" phases.
Claim 126
Dependent Claim
133 words
In a thermally addressed visual display device having a liquid crystal medium including at least one liquid crystal cholesteric compound mixed with at least one coloring agent, the method of displaying a dark image against a lighter background, comprising the steps of: (a) passing said medium rapidly through a thermal transition from an upper thermal, cholesteric phase to a lower thermal, smectic phase; (b) sensitizing certain portions of said medium defining a background to develop a substantially light transparent state in said background when said medium passes rapidly into said lower thermal, smectic phase, the remaining unsensitized portions of said medium developing a light absorbing state; (c) passing light through said medium; and (d) absorbing light in said unsensitized portions of said medium to provide a dark image upon said lighter sensitized background.
Claim 127
Dependent Claim
133 words
In a thermally addressed visual display device having a liquid crystal medium including at least one liquid crystal cholesteric compound mixed with at least one coloring agent, the method of displaying a dark image against a lighter background, comprising the steps of: (a) passing said medium rapidly through a thermal transition from an upper thermal, cholesteric phase to a lower thermal, smectic phase; (b) sensitizing certain portions of said medium defining a background to develop a substantially light transparent state in said background when said medium passes rapidly into said lower thermal, smectic phase, the remaining unsensitized portions of said medium developing a light absorbing state; (c) passing light through said medium; and (d) absorbing light in said unsensitized portions of said medium to provide a dark image upon said lighter sensitized background.
Claim 128
Dependent Claim
41 words
The method of claim 115, wherein said dark image is observable from the same side as the light passing through said medium, and comprising the further step of: (e) diffusely reflecting the light passing through said medium back through said medium.
Claim 129
Dependent Claim
51 words
The method of claim 115, wherein said medium has dielectric anisotropy and further wherein the sensitized portions of said medium are sensitized by the further step of: (e) applying a voltage to said certain portions of said medium in order to sensitize said certain portions into developing said light transparent state.
Claim 130
Dependent Claim
22 words
The method of claim 117, wherein said voltage is applied in a given chronological sequence to said certain portions of said medium.
Claim 131
Dependent Claim
17 words
The method of claim 115, wherein said sensitized portions of said medium are sensitized in chronological sequence.
Claim 132
Dependent Claim
33 words
The method of claim 115, further comprising the step of: (e) passing said medium through said transition from said lower thermal, smectic phase to said upper thermal, cholesteric phase prior to step (a).
Claim 133
Dependent Claim
16 words
The method of claim 120, wherein said transition step (e) is accomplished by heating said medium.
Claim 134
Dependent Claim
17 words
The method of claim 115, wherein said transition step (a) is accomplished by rapidly cooling said medium.
Claim 135
Dependent Claim
29 words
The method of claim 115, wherein said medium passes rapidly through two thermal transitions rapidly between an upper isotropic phase, an intermediate cholesteric phase, and a lower smectic phase.
Claim 136
Dependent Claim
18 words
The method of claim 115, wherein said light passing through said medium in step (c) comprises ambient light.
Claim 137
Dependent Claim
218 words
In a thermally addressed visual display device having a liquid crystal medium including at least one liquid crystal cholesteric compound mixed with at least one pleochroic dye of high order parameter and having dielectric anisotropy, said medium being thermally sensitive and having a transition between an upper and a lower thermal phase, said upper thermal phase being a cholesteric phase and said lower thermal phase being a smectic phase, said medium having two possible light modulating states in said lower thermal, smectic phase characterized by development of respective light absorbing and homeotropic textures in said medium, said light absorbing texture being normally substantially light absorbing and said homeotropic texture being substantially transparent, the method of displaying a dark image against a lighter background, comprising the steps of: (a) rapidly passing said medium through said transition from said upper thermal, cholesteric phase to said lower thermal, smectic phase; (b) sensitizing certain portions of said medium defining a background to develop said second substantially light transparent state in said background when said medium passes rapidly into its lower thermal, smectic phase, the remaining unsensitized portions of said medium developing said light absorbing state; (c) passing light through said medium; and (d) absorbing light in said unsensitized portions of said medium to provide a dark image upon said lighter sensitized background.
Claim 138
Dependent Claim
218 words
In a thermally addressed visual display device having a liquid crystal medium including at least one liquid crystal cholesteric compound mixed with at least one pleochroic dye of high order parameter and having dielectric anisotropy, said medium being thermally sensitive and having a transition between an upper and a lower thermal phase, said upper thermal phase being a cholesteric phase and said lower thermal phase being a smectic phase, said medium having two possible light modulating states in said lower thermal, smectic phase characterized by development of respective light absorbing and homeotropic textures in said medium, said light absorbing texture being normally substantially light absorbing and said homeotropic texture being substantially transparent, the method of displaying a dark image against a lighter background, comprising the steps of: (a) rapidly passing said medium through said transition from said upper thermal, cholesteric phase to said lower thermal, smectic phase; (b) sensitizing certain portions of said medium defining a background to develop said second substantially light transparent state in said background when said medium passes rapidly into its lower thermal, smectic phase, the remaining unsensitized portions of said medium developing said light absorbing state; (c) passing light through said medium; and (d) absorbing light in said unsensitized portions of said medium to provide a dark image upon said lighter sensitized background.
Claim 139
Dependent Claim
41 words
The method of claim 125, wherein said dark image is observable from the same side as the light passing through said medium, and comprising the further step of: (e) diffusely reflecting the light passing through said medium back through said medium.
Claim 140
Dependent Claim
43 words
The method of claim 126, wherein the sensitized portions of said medium are sensitized by the further step of: (e) applying a voltage to said certain portions of said medium in order to sensitize said certain portions into developing said light transparent state.
Claim 141
Dependent Claim
22 words
The method of claim 127, wherein said voltage is applied in a given chronological sequence to said certain portions of said medium.
Claim 142
Dependent Claim
17 words
The method of claim 126, wherein said sensitized portions of said medium are sensitized in chronological sequence.
Claim 143
Dependent Claim
33 words
The method of claim 126, further comprising the step of: (e) passing said medium through said transition from said lower thermal, smectic phase to said upper thermal, cholesteric phase prior to step (a).
Claim 144
Dependent Claim
16 words
The method of claim 130, wherein said transition step (e) is accomplished by heating said medium.
Claim 145
Dependent Claim
17 words
The method of claim 126, wherein said transition step (a) is accomplished by rapidly cooling said medium.
Claim 146
Dependent Claim
28 words
The method of claim 126, wherein said medium passes rapidly through two thermal transitions between an upper isotropic phase, an intermediate cholesteric phase, and a lower smectic phase.
Claim 147
Dependent Claim
18 words
The method of claim 126, wherein said light passing through said medium in step (c) comprises ambient light.
References Cited (Backward Citations)
US3114836A
Cited
US3529156A
Cited
US3524726A
Cited
US3792915A
Cited
US3796999A
Cited
US4219255A
Cited
US4202010A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-07-04 | 1987-01-03 | 1987-07-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-07-04 | 1991-01-03 | 1991-07-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-07-04 | 1995-01-03 | 1995-07-05 | $7700.00 | Window Closed / Lapsed |