US5585950A
Expired / Lapsed
US
⏱️ 0.0 years remaining
STN LCD device displaying multiple colors in response to different voltages which includes a retardation plate
Assignee: Casio Computer Co Ltd
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Filing: 1994-04-05
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Granted: 1996-12-17
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Expires: 2014-04-05
Abstract
Abstract A pair of polarizing plates are disposed on two sides of an STN type liquid crystal cell constituted by a liquid crystal twist-aligned at a twist angle of 180 DEG to 270 DEG . A retardation plate is disposed between one of the polarizing plates and the liquid crystal cell in such a manner that the optical axis of the retardation plate crosses the transmission axis of the adjacent polarizing plate at 35 DEG to 55 DEG . The pair of polarizing plates are arranged such that their transmission axes are parallel to each other. The liquid crystal cell is arranged such that the optical axis of the retardation plate crosses the aligning direction of the liquid crystal molecules on the substrate side adjacent to the retardation plate at a predetermined angle. A driving circuit is connected to the liquid crystal cell. This circuit serves to apply a voltage to the liquid crystal in accordance with display data having color information to change the polarized state of elliptically polarized light transmitted through the liquid crystal to change the color of emerging light.
Inventors
- 👤 Toshiharu Nishino
- 👤 Toshihiko Mori
- 👤 Yasushi Nishida
- 👤 Kazuyoshi Arai
- 👤 Yukikazu Tanaka
- 👤 Hideshi Sato
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 17:08
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/137; G02F1/139; G02F1/1396; G02F1/1397; G02F1/133; G02F1/1333; G02F1/1335; G02F1/13363; G02F2203/00; G02F2203/34
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
240 words
A color liquid crystal display apparatus comprising: a pair of substrates having opposing surfaces, electrodes respectively formed on the opposing surfaces, and aligning films respectively formed to cover said electrodes, said aligning films having undergone aligning treatment in predetermined directions; a liquid crystal layer formed between said pair of substrates and having liquid crystal molecules aligned to be twisted at a twist angle of 180° to 270° from one substrate to the other substrate; a pair of polarizing plates disposed outside said pair of substrates to sandwich said substrates and respectively having transmission axes for linearly polarizing incident light; a retardation plate having a maximum refraction index direction which is within a plane parallel to a surface of said retardation plate and having a value of retardation for coloring light transmitted through the liquid crystal display apparatus, in combination with the Δn·d of the liquid crystal layer, said retardation plate being disposed between said pair of polarizing plates such that an angle defined by said maximum refractive index direction, and the transmission axis of an adjacent one of said polarizing plates is 35° to 55°; and driving means, connected to said electrodes, for applying a voltage to said liquid crystal layer to change a polarized state of light transmitted through said liquid crystal layer so as to change a color of light transmitted through said polarizing plate on an exit side into plural colors including at least two chromatic colors.
Claim 2
Dependent Claim
240 words
A color liquid crystal display apparatus comprising: a pair of substrates having opposing surfaces, electrodes respectively formed on the opposing surfaces, and aligning films respectively formed to cover said electrodes, said aligning films having undergone aligning treatment in predetermined directions; a liquid crystal layer formed between said pair of substrates and having liquid crystal molecules aligned to be twisted at a twist angle of 180° to 270° from one substrate to the other substrate; a pair of polarizing plates disposed outside said pair of substrates to sandwich said substrates and respectively having transmission axes for linearly polarizing incident light; a retardation plate having a maximum refraction index direction which is within a plane parallel to a surface of said retardation plate and having a value of retardation for coloring light transmitted through the liquid crystal display apparatus, in combination with the Δn·d of the liquid crystal layer, said retardation plate being disposed between said pair of polarizing plates such that an angle defined by said maximum refractive index direction, and the transmission axis of an adjacent one of said polarizing plates is 35° to 55°; and driving means, connected to said electrodes, for applying a voltage to said liquid crystal layer to change a polarized state of light transmitted through said liquid crystal layer so as to change a color of light transmitted through said polarizing plate on an exit side into plural colors including at least two chromatic colors.
Claim 3
Dependent Claim
18 words
An apparatus according to claim 1, further comprising another retardation plate disposed between said pair of polarizing plates.
Claim 4
Dependent Claim
29 words
An apparatus according to claim 2, wherein said another retardation plate is disposed between said retardation plate and one of said pair of polarizing plates which is adjacent thereto.
Claim 5
Dependent Claim
38 words
An apparatus according to claim 2, wherein said another retardation plate is disposed to be adjacent to one of said substrates which is on an opposite side to the other substrate to which said retardation plate is adjacent.
Claim 6
Dependent Claim
20 words
An apparatus according to claim 1, further comprising a reflection plate disposed outside one of said pair of polarizing plates.
Claim 7
Dependent Claim
18 words
An apparatus according to claim 5, further comprising another retardation plate disposed between said pair of polarizing plates.
Claim 8
Dependent Claim
23 words
An apparatus according to claim 6, wherein said another retardation plate is disposed between said retardation plate and said polarizing plate adjacent thereto.
Claim 9
Dependent Claim
38 words
An apparatus according to claim 6, wherein said another retardation plate is disposed outside one of said pair of substrates which is located on an opposite side to the other substrate to which said retardation plate is adjacent.
Claim 10
Dependent Claim
70 words
An apparatus according to claim 1, wherein said retardation plate is a retardation plate which satisfies n X >n Z >n Y where n X , n y , and n Z are refractive indexes in an X direction in which the refractive index is the maximum, a Y direction perpendicular to the X direction within a plane parallel to said retardation plate, and a Z direction of thickness, respectively.
Claim 11
Dependent Claim
33 words
An apparatus according to claim 1, wherein liquid crystal molecules of said liquid crystal layer are aligned to be twisted from one substrate to the other substrate at a twist angle of 250°.
Claim 12
Dependent Claim
51 words
An apparatus according to claim 1, wherein said pair of substrates include a plurality of electrodes formed on the opposing surfaces thereof to extend in orthogonal directions, and portions where electrodes respectively formed on the opposing surfaces oppose form a plurality of display dots arranged in the form of a matrix.
Claim 13
Dependent Claim
60 words
An apparatus according to claim 11, wherein said driving means includes driving voltage generating means for generating a plurality of voltages having different magnitudes, display signal generating means for generating a display signal corresponding to color data to be displayed, and display driving means for selecting a driving voltage in accordance with the display signal and forming a driving waveform.
Claim 14
Dependent Claim
76 words
An apparatus according to claim 1, wherein said driving means comprises means for generating a plurality of signal voltages corresponding to a plurality of predetermined different display colors, and applied voltage control means for selecting one of the plurality of signal voltages for each frame in accordance with color to be displayed in one period constituted by a predetermined number of frames, and applying a voltage corresponding to a display color to said liquid crystal layer.
Claim 15
Dependent Claim
75 words
An apparatus according to claim 1, further comprising pixel electrodes regularly arranged on one of said pair of substrates, and thin-film transistors arranged in correspondence with said respective pixel electrodes, each of said thin-film transistors having a source electrode connected to a corresponding one of said pixel electrodes, a drain electrode connected to a signal line for supplying a display signal, and a gate electrode connected to a scanning line for supplying a scanning signal.
Claim 16
Dependent Claim
239 words
A color liquid crystal display apparatus comprising:: a pair of substrates having opposing surfaces, electrodes respectively formed on the opposing surfaces, and aligning films respectively formed to cover said electrodes, said aligning films having undergone aligning treatment in predetermined directions; a liquid crystal layer formed between said pair of substrates and having liquid crystal molecules aligned to be twisted at a twist angle of 180° to 270° from one substrate to the other substrate; a polarizing plate disposed outside one of said pair of substrates and having a transmission axis for linearly polarizing incident light; a reflection plate disposed on an opposite side to said polarizing plate with respect to said pair of substrates; a retardation plate having a maximum refractive index direction which is within a plane parallel to a surface of said retardation plate and having a value of retardation for coloring light transmitted through the liquid crystal display apparatus, in combination with the Δn·d of the liquid crystal layer, said retardation plate being disposed between said polarizing plate and said reflection plate such that an angle defined by said maximum refractive index direction, and the transmission axis of said polarizing plate is 35° to 55°; and driving means, connected to said electrodes, for applying a voltage to said liquid crystal layer to change a polarized state of light transmitted through said polarizing plate on an exit side into plural colors including at least two chromatic colors.
Claim 17
Dependent Claim
239 words
A color liquid crystal display apparatus comprising:: a pair of substrates having opposing surfaces, electrodes respectively formed on the opposing surfaces, and aligning films respectively formed to cover said electrodes, said aligning films having undergone aligning treatment in predetermined directions; a liquid crystal layer formed between said pair of substrates and having liquid crystal molecules aligned to be twisted at a twist angle of 180° to 270° from one substrate to the other substrate; a polarizing plate disposed outside one of said pair of substrates and having a transmission axis for linearly polarizing incident light; a reflection plate disposed on an opposite side to said polarizing plate with respect to said pair of substrates; a retardation plate having a maximum refractive index direction which is within a plane parallel to a surface of said retardation plate and having a value of retardation for coloring light transmitted through the liquid crystal display apparatus, in combination with the Δn·d of the liquid crystal layer, said retardation plate being disposed between said polarizing plate and said reflection plate such that an angle defined by said maximum refractive index direction, and the transmission axis of said polarizing plate is 35° to 55°; and driving means, connected to said electrodes, for applying a voltage to said liquid crystal layer to change a polarized state of light transmitted through said polarizing plate on an exit side into plural colors including at least two chromatic colors.
Claim 18
Dependent Claim
20 words
An apparatus according to claim 15, further comprising another retardation plate disposed between said polarizing plate and said reflection plate.
Claim 19
Dependent Claim
21 words
An apparatus according to claim 16, wherein said another retardation plate is disposed between said retardation plate and said polarizing plate.
Claim 20
Dependent Claim
38 words
An apparatus according to claim 16, wherein said another retardation plate is disposed to be adjacent to one of said substrates which is on an opposite side to the other substrate to which said retardation plate is adjacent.
Claim 21
Dependent Claim
70 words
An apparatus according to claim 15, wherein said retardation plate is a retardation plate which satisfies n X >n Z >n Y where n X , n Y , and n Z are refractive indexes in an X direction in which the refractive index is the maximum, a Y direction perpendicular to the X direction within a plane parallel to said retardation plate, and a Z direction of thickness, respectively.
Claim 22
Dependent Claim
32 words
An apparatus according to claim 15, wherein said liquid crystal layer has liquid crystal molecules aligned to be twisted from one substrate to the other substrate at a twist angle of 250°.
Claim 23
Dependent Claim
51 words
An apparatus according to claim 15, wherein said pair of substrates include a plurality of electrodes formed on the opposing surfaces thereof to extend in orthogonal directions, and portions where electrodes respectively formed on the opposing surfaces oppose form a plurality of display dots arranged in the form of a matrix.
Claim 24
Dependent Claim
60 words
An apparatus according to claim 21, wherein said driving means includes driving voltage generating means for generating a plurality of voltages having different magnitudes, display signal generating means for generating a display signal corresponding to color data to be displayed, and display driving means for selecting a driving voltage in accordance with the display signal and forming a driving waveform.
Claim 25
Dependent Claim
76 words
An apparatus according to claim 15, wherein said driving means comprises means for generating a plurality of signal voltages corresponding to a plurality of predetermined different display colors, and applied voltage control means for selecting one of the plurality of signal voltages for each frame in accordance with color to be displayed in one period constituted by a predetermined number of frames, and applying a voltage corresponding to a display color to said liquid crystal layer.
Claim 26
Dependent Claim
75 words
An apparatus according to claim 15, further comprising pixel electrodes regularly arranged on one of said pair of substrates, and thin-film transistors arranged in correspondence with said respective pixel electrodes, each of said thin-film transistors having a source electrode connected to a corresponding one of said pixel electrodes, a drain electrode connected to a signal line for supplying a display signal, and a gate electrode connected to a scanning line for supplying a scanning signal.
Claim 27
Dependent Claim
247 words
A color liquid crystal display apparatus for changing a display color in accordance with an applied voltage, comprising: a pair of substrates having opposing surfaces, electrodes respectively formed on the opposing surfaces, and aligning films respectively formed to cover said electrodes, said aligning films having undergone aligning treatment in predetermined directions; a liquid crystal layer formed between said pair of substrates and having liquid crystal molecules aligned to be twisted at a twist angle of 180° to 270° from one substrate to the other substrate; a pair of polarizing plates disposed outside said pair of substrates to sandwich said substrates and respectively having transmission axes for linearly polarizing incident light; a retardation plate having a maximum refractive index direction which is within a plane parallel to a surface of said retardation plate and having a value of retardation for coloring light transmitted through the liquid crystal display apparatus, in combination with the Δn·d of the liquid crystal layer, said retardation plate being disposed to be adjacent to one of said pair of polarizing plates which is located on an incident side, for elliptically polarizing linearly polarized light transmitted through said one of said pair of polarizing plates; and driving means, connected to said electrodes, for applying at least three different voltages to said liquid crystal layer to change a polarized state of light transmitted through said liquid crystal layer so as to change a display color to at least three colors including at least two chromatic colors.
Claim 28
Dependent Claim
247 words
A color liquid crystal display apparatus for changing a display color in accordance with an applied voltage, comprising: a pair of substrates having opposing surfaces, electrodes respectively formed on the opposing surfaces, and aligning films respectively formed to cover said electrodes, said aligning films having undergone aligning treatment in predetermined directions; a liquid crystal layer formed between said pair of substrates and having liquid crystal molecules aligned to be twisted at a twist angle of 180° to 270° from one substrate to the other substrate; a pair of polarizing plates disposed outside said pair of substrates to sandwich said substrates and respectively having transmission axes for linearly polarizing incident light; a retardation plate having a maximum refractive index direction which is within a plane parallel to a surface of said retardation plate and having a value of retardation for coloring light transmitted through the liquid crystal display apparatus, in combination with the Δn·d of the liquid crystal layer, said retardation plate being disposed to be adjacent to one of said pair of polarizing plates which is located on an incident side, for elliptically polarizing linearly polarized light transmitted through said one of said pair of polarizing plates; and driving means, connected to said electrodes, for applying at least three different voltages to said liquid crystal layer to change a polarized state of light transmitted through said liquid crystal layer so as to change a display color to at least three colors including at least two chromatic colors.
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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) | 1999-12-17 | 2000-06-17 | 2000-12-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-12-17 | 2004-06-17 | 2004-12-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-12-17 | 2008-06-17 | 2008-12-17 | $7700.00 | Window Closed / Lapsed |