Patent US447486A successfully refreshed from Google Patents.
Patent US5654784A successfully refreshed from Google Patents.
US5654784A
Expired / Lapsed
US
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Liquid crystal devices comprising a multitude of domains having different threshold voltages for switching liquid crystals
Assignee: Sony Corp
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Filing: 1993-10-22
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Granted: 1997-08-05
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Expires: 2013-10-22
Abstract
Abstract A liquid crystal device comprises a pair of substrates and a liquid crystal provided between the paired substrates wherein domains whose threshold voltages are different from one another are finely distributed throughout the liquid crystal. In particular, the respective substrates each has a transparent electrode and an alignment film formed thereon in this order and the substrates are assembled to establish a given space therebetween, and a ferroelectric liquid crystal being injected into the given space wherein domains are finely distributed as set out above, thereby providing a a liquid crystal display device. The fine distribution is such that when a transmittance through inverted domains is 25%, the number of domains (microdomains) having a size of larger than 2 mu m phi in a field of 1 mm2 is not smaller than 300, preferably not smaller than 600, and the width of the threshold voltage within the domains is not smaller than 2 volts within a transmittance range of from 10 to 90%. The liquid crystal device, particularly the display device, keeps a high contrast and can easily, reliably realize an analog gray-scale display at low costs.
Inventors
- 👤 Akio Yasuda
- 👤 Keiichi Nito
- 👤 Eriko Matsui
- 👤 Hidehiko Takanashi
- 👤 Yang Ying Bao
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 15:00
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/137; G02F1/139; G02F1/141; G02F1/133; G02F1/1333; G02F1/1337; G02F1/133707; G02F1/133711; G02F1/133734; G09; G09G; G09G3/00; G09G3/20; G09G3/34; G09G3/36; G09G3/3611; G09G3/3648; G09G3/3651; G02F1/133796; G02F2203/00; G02F2203/30
Claims Analysis
Total Claims: 29
Claim 1
Independent Claim
81 words
A liquid crystal device of the type which comprises a pair of substrates, each having a planar conductor, and a liquid crystal provided between the paired substrates, fine domains whose threshold voltages for switching the liquid crystal are different from one another being finely distributed in said liquid crystal, wherein a temperature dependence of a cone angle of liquid crystal molecules constituting a plurality of domains whose threshold voltages are different from one another is smaller than that of a monodomain.
Claim 2
Dependent Claim
81 words
A liquid crystal device of the type which comprises a pair of substrates, each having a planar conductor, and a liquid crystal provided between the paired substrates, fine domains whose threshold voltages for switching the liquid crystal are different from one another being finely distributed in said liquid crystal, wherein a temperature dependence of a cone angle of liquid crystal molecules constituting a plurality of domains whose threshold voltages are different from one another is smaller than that of a monodomain.
Claim 3
Dependent Claim
84 words
A liquid crystal device of the type which comprises a pair of substrates, each having a planar conductor, and a liquid crystal provided between the paired substrates, fine domains whose threshold voltages for switching the liquid crystal are different from one another being finely distributed in said liquid crystal wherein fine particles are added to said liquid crystal, so that fine domains whose threshold voltages are different from one another are formed, and wherein said fine particles are surface treated to improve dispersability thereof.
Claim 4
Dependent Claim
84 words
A liquid crystal device of the type which comprises a pair of substrates, each having a planar conductor, and a liquid crystal provided between the paired substrates, fine domains whose threshold voltages for switching the liquid crystal are different from one another being finely distributed in said liquid crystal wherein fine particles are added to said liquid crystal, so that fine domains whose threshold voltages are different from one another are formed, and wherein said fine particles are surface treated to improve dispersability thereof.
Claim 5
Dependent Claim
84 words
A liquid crystal device of the type which comprises a pair of substrates, and a liquid crystal provided between the paired substrates, fine domains whose threshold voltages for switching the liquid crystal are different from one another being finely distributed in said liquid crystal, wherein an alignment film formed on at least one of the substrates is an obliquely evaporated film consisting of a multitude of rhombic columns wherein at least a part of a conductive material is intervened in between adjacent rohmbic columns.
Claim 6
Dependent Claim
84 words
A liquid crystal device of the type which comprises a pair of substrates, and a liquid crystal provided between the paired substrates, fine domains whose threshold voltages for switching the liquid crystal are different from one another being finely distributed in said liquid crystal, wherein an alignment film formed on at least one of the substrates is an obliquely evaporated film consisting of a multitude of rhombic columns wherein at least a part of a conductive material is intervened in between adjacent rohmbic columns.
Claim 7
Dependent Claim
31 words
A liquid crystal device according to claim 3, wherein said conductive material has an electric conductivity which is higher than an electric conductivity of the evaporated film and/or said liquid crystal.
Claim 8
Dependent Claim
22 words
A liquid crystal device according to claim 3, wherein said conductive material has an electric conductivity not smaller than 1×10 -12 S/cm.
Claim 9
Dependent Claim
85 words
A liquid crystal device of the type which comprises a pair of substrates, and a liquid crystal provided between the paired substrates, fine domains whose threshold voltages for switching the liquid crystal are different from one another being finely distributed, in said liquid crystal, wherein said liquid crystal has angles of layer inclination which are different from each other at regions in the vicinity of an alignment film formed on at least one of said substrates and at bulk regions other than the first-mentioned regions.
Claim 10
Dependent Claim
85 words
A liquid crystal device of the type which comprises a pair of substrates, and a liquid crystal provided between the paired substrates, fine domains whose threshold voltages for switching the liquid crystal are different from one another being finely distributed, in said liquid crystal, wherein said liquid crystal has angles of layer inclination which are different from each other at regions in the vicinity of an alignment film formed on at least one of said substrates and at bulk regions other than the first-mentioned regions.
Claim 11
Dependent Claim
24 words
A liquid crystal device according to claim 6, wherein peaks of the X-ray diffraction intensity have a half width of not smaller than 8°.
Claim 12
Dependent Claim
160 words
A liquid crystal device of the type which comprises a pair of substrates, each having a planar conductor, and a liquid crystal provided between the paired substrates, fine domains whose threshold voltages for switching the liquid crystal are different from one another being finely distributed in said liquid crystal wherein said device comprises a pair of substrates each having a transparent electrode and an alignment film formed thereon in this order, the paired substrates being arranged to have a given space therebetween so that the respective alignment films are facing each other, and a ferroelectric liquid crystal being injected into the given space, wherein the number of domains having a size larger than 2 μmφ in a field of 1 mm 2 is not smaller than 300, and a transmittance through inverted domains is 25%, and the width of the threshold voltage within the domains is not smaller than 2 volts within a transmittance range of from 10 to 90%.
Claim 13
Dependent Claim
160 words
A liquid crystal device of the type which comprises a pair of substrates, each having a planar conductor, and a liquid crystal provided between the paired substrates, fine domains whose threshold voltages for switching the liquid crystal are different from one another being finely distributed in said liquid crystal wherein said device comprises a pair of substrates each having a transparent electrode and an alignment film formed thereon in this order, the paired substrates being arranged to have a given space therebetween so that the respective alignment films are facing each other, and a ferroelectric liquid crystal being injected into the given space, wherein the number of domains having a size larger than 2 μmφ in a field of 1 mm 2 is not smaller than 300, and a transmittance through inverted domains is 25%, and the width of the threshold voltage within the domains is not smaller than 2 volts within a transmittance range of from 10 to 90%.
Claim 14
Dependent Claim
205 words
A liquid crystal device of the type which comprises a pair of substrates, each having a planar conductor, and a liquid crystal provided between the paired substrates, fine domains whose threshold voltages for switching the liquid crystal are different from one another being finely distributed in said liquid crystal wherein said device comprises a pair of substrates each having a transparent electrode and an alignment film formed thereon in this order, the paired substrates being arranged to have a given space therebetween so that the respective alignment films are facing each other, and a ferroelectric liquid crystal being injected into the given space, wherein the number of domains having a size larger than 2 μmφ in a field of 1 mm 2 is not smaller than 300, and a transmittance through inverted domains is 25%, and the width of the threshold voltage within the domains is not smaller than 2 volts within a transmittance range of from 10 to 90%, wherein when said liquid crystal is subjected to measurement of x-ray diffraction, two or more highest peaks of an x-ray diffraction intensity which exhibit angles of the layer inclination exist at an incident angle of x-ray not higher than 90° or not lower than 90°.
Claim 15
Dependent Claim
205 words
A liquid crystal device of the type which comprises a pair of substrates, each having a planar conductor, and a liquid crystal provided between the paired substrates, fine domains whose threshold voltages for switching the liquid crystal are different from one another being finely distributed in said liquid crystal wherein said device comprises a pair of substrates each having a transparent electrode and an alignment film formed thereon in this order, the paired substrates being arranged to have a given space therebetween so that the respective alignment films are facing each other, and a ferroelectric liquid crystal being injected into the given space, wherein the number of domains having a size larger than 2 μmφ in a field of 1 mm 2 is not smaller than 300, and a transmittance through inverted domains is 25%, and the width of the threshold voltage within the domains is not smaller than 2 volts within a transmittance range of from 10 to 90%, wherein when said liquid crystal is subjected to measurement of x-ray diffraction, two or more highest peaks of an x-ray diffraction intensity which exhibit angles of the layer inclination exist at an incident angle of x-ray not higher than 90° or not lower than 90°.
Claim 16
Dependent Claim
31 words
A liquid crystal device according to claim 8, wherein fine particles added to said liquid crystal have a specific gravity which is 0.1 to 10 times that of said liquid crystal.
Claim 17
Dependent Claim
39 words
A liquid crystal device according to claim 8, further comprising a film formed on each of said alignment films and made of a material selected from the group consisting of charge transfer complexes, organic pigments, metals, oxides and fluorides.
Claim 18
Dependent Claim
15 words
A liquid crystal device according to claim 11, wherein said material is a conductive material.
Claim 19
Dependent Claim
23 words
A liquid crystal device according to any of claim 3 and 5 to 21, wherein said alignment film is annealed after vacuum deposition.
Claim 20
Dependent Claim
21 words
A liquid crystal device according to claim 8, wherein said respective alignment films is a vacuum deposition film of silicon oxide.
Claim 21
Dependent Claim
44 words
A liquid crystal device according to claim 8 or 9, wherein a distribution width of an apparent pretilt angle of liquid crystal molecules constituting a plurality of domains whose threshold voltages are different from one another is not less than 6° in one pixel.
Claim 22
Dependent Claim
30 words
A liquid crystal device according to claim 8 or 9, wherein said device is applied with two or more levels of voltages whereby two or more gray-scale levels are obtained.
Claim 23
Dependent Claim
27 words
A liquid crystal device according to claim 8 or 9, wherein fine particles added to said liquid crystal have surfaces whose pH is not smaller than 2.
Claim 24
Dependent Claim
29 words
A liquid crystal device according to claim 8 or 9, wherein fine particles are added to said liquid crystal in an amount of not larger than 50 wt %.
Claim 25
Dependent Claim
28 words
A liquid crystal device according to claims 8 or 9, wherein fine particles added to said liquid crystal are comprised of carbon black obtained by a furnace process.
Claim 26
Dependent Claim
24 words
A liquid crystal device according to claims 8 or 9, wherein fine particles added to said liquid crystal are comprised of amorphous titanium oxide.
Claim 27
Dependent Claim
31 words
A liquid crystal device according to claim 8 or 9, wherein fine particles added to said liquid crystal have has a controlled size distribution whereby a gray-scale display characteristic is controlled.
Claim 28
Dependent Claim
26 words
A liquid crystal device according to claim 21, wherein said size distribution of said fine particles has a standard deviation of not smaller than 9 nm.
Claim 29
Dependent Claim
47 words
A liquid crystal device according to claim 8 or 9, wherein an apparent tilt angle of liquid crystal molecules constituting a plurality of domains whose threshold voltages are different from one another is varied within a range not less than +1° from that of a monodomain state.
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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) | 2000-08-04 | 2001-02-03 | 2001-08-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-08-04 | 2005-02-03 | 2005-08-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-08-04 | 2009-02-03 | 2009-08-05 | $7700.00 | Window Closed / Lapsed |