EP0177365A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Liquid crystal device for time-division driving
Assignee: Canon Inc
•
Filing: 1985-10-04
•
Granted: —
•
Expires: 2005-10-04
Abstract
Abstract A liquid crystal device for time-division driving comprising a plurality of picture elements arranged in a plurality of rows. Each picture element is composed of opposite electrodes, a layer of a ferroelectric liquid crystal having a volume resistivity of 1 x 10 9 Ω.cm or larger, disposed between the opposite electrodes and placed under bistability condition, and an insulating layer disposed on at least one of the opposite electrodes. The liquid crystal device is adapted to driving according to a time-division driving scheme wherein a writing signal is applied row by row and cyclically to the picture elements, and a particular row of picture elements to which the writing signal has been applied in a writing cycle retain their written states until a writing signal is applied to the particular row in a subsequent writing cycle.
Inventors
- 👤 Shinjiro Okada
- 👤 Junichiro 948 Minaminagatsuda-Danchi Kanbe
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-05 15:35
CPC Classifications
G; G09; G09G; G09G3/00; G09G3/20; G09G3/34; G09G3/36; G09G3/3611; G09G3/3622; G09G3/3629; C; C09; C09K; C09K19/00; C09K19/02; C09K19/0225; C09K19/04; C09K19/06; C09K19/08; C09K19/10; C09K19/20; C09K19/2007; C09K19/2021; C09K19/24; C09K19/26; G09G3/3648; G09G3/3651; G09G2310/00; G09G2310/06; Y; Y10; Y10S; Y10S359/00; Y10S359/90
Claims Analysis
Total Claims: 29
Claim 1
Independent Claim
136 words
A liquid crystal device for time-division driving comprising a plurality of picture elements arranged in a plurality of rows; each picture element comprising opposite electrodes, a layer of a ferroelectric liquid crystal disposed between the opposite electrodes and placed under bistability condition, and an insulating layer disposed on at least one of the opposite electrodes; said liquid crystal device being adapted to driving according to a time-division driving scheme wherein a writing signal is applied row by row and cyclically to said picture elements, and a particular row of picture elements to which the writing signal has been applied in a writing cycle retain their written states until a writing signal is applied to said particular row in a subsequent writing cycle; said ferroelectric liquid crystal having a volume resistivity of 1x10 9 Ω.cm or larger.
Claim 2
Dependent Claim
136 words
A liquid crystal device for time-division driving comprising a plurality of picture elements arranged in a plurality of rows; each picture element comprising opposite electrodes, a layer of a ferroelectric liquid crystal disposed between the opposite electrodes and placed under bistability condition, and an insulating layer disposed on at least one of the opposite electrodes; said liquid crystal device being adapted to driving according to a time-division driving scheme wherein a writing signal is applied row by row and cyclically to said picture elements, and a particular row of picture elements to which the writing signal has been applied in a writing cycle retain their written states until a writing signal is applied to said particular row in a subsequent writing cycle; said ferroelectric liquid crystal having a volume resistivity of 1x10 9 Ω.cm or larger.
Claim 3
Dependent Claim
26 words
A liquid crystal device according to Claim 1, wherein said ferroelectric liquid crystal has volume resistivity of 1x10 10 Ω. c m to 1x10 13 Ω.cm.
Claim 4
Dependent Claim
25 words
A liquid crystal device according to Claim 1, wherein said ferroelectric liquid crystal has a volume resistivity of 1x10 11 Ω.cm to 1x10 13 Ω.cm.
Claim 5
Dependent Claim
25 words
A liquid crystal device according to Claim 1, wherein said ferroelectric liquid crystal has a volume resistivity of 1x10 12 Ω.cm to 1x10 13 Ω.cm.
Claim 6
Dependent Claim
20 words
A liquid crystal device according to Claim 1, wherein said insulating layer is a film of an inorganic insulating material.
Claim 7
Dependent Claim
55 words
A liquid crystal device according to Claim 5, wherein said inorganic insulating material is at least one member selected from the group consisting of silicon nitride, silicon nitride containing hydrogen, silicon carbide, silicon carbide containing hydrogen, silicon oxide, boron nitride, boron nitride containing hydrogen, cerium oxide, aluminum oxide, zirconium oxide, titanium oxide and magnesium fluoride.
Claim 8
Dependent Claim
20 words
A liquid crystal device according to Claim 1, wherein said insulating layer is a film of an organic insulating material.
Claim 9
Dependent Claim
50 words
A liquid crystal device according to Claim 7, wherein said organic insulating material is at least one member selected from the group consisting of polyvinyl alcohol, polyimide, polyamide-imide, polyester-imide, polyparaxylylene, polyester, polycarbonate, polyvinylacetal, polyvinyl chloride, polyvinyl acetate, polyamide, polystyrene, cellulose resin, melamine resin, urea resin, acrylic resin and photoresist resins.
Claim 10
Dependent Claim
24 words
A liquid crystal device according to Claim 1, wherein said insulating layer provides a capacitance of 5.5 x 10 3 pF/cm 2 or above.
Claim 11
Dependent Claim
29 words
A liquid crystal device according to Claim 1, wherein said insulating layer provides a capacitance of 5.5 x 10 3 to 3.0 x 10 5 p F/cm 2 .
Claim 12
Dependent Claim
30 words
A liquid crystal device according to Claim 1, wherein said insulating layer provides a capacitance of 9.0 x 10 3 to 5. 5 x 10 4 p F/cm 2 .
Claim 13
Dependent Claim
18 words
A liquid crystal device according to Claim 1, wherein said ferroelectric liquid crystal is a smectic liquid crystal.
Claim 14
Dependent Claim
19 words
A liquid crystal device according to Claim 1, wherein said ferroelectric liquid crystal is a chiral smectic liquid crystal.
Claim 15
Dependent Claim
31 words
A liquid crystal device according to Claim 13, wherein said chiral smectic liquid crystal is in C phase, H phase, I phase, J phase, K phase, G phase and F phase.
Claim 16
Dependent Claim
19 words
A liquid crystal device according to Claim 13, wherein said chiral smectic liquid crystal is in a non-spiral structure.
Claim 17
Dependent Claim
31 words
A liquid crystal device according to Claim 1, wherein an alternating voltage for preventing reversal phenomenon is applied to a picture element to which said writing signal is not being applied.
Claim 18
Dependent Claim
16 words
A liquid crystal device according to Claim 16, wherein said alternating voltage is an AC voltage.
Claim 19
Dependent Claim
146 words
A driving method for a liquid crystal device comprising a plurality of picture elements arranged in a plurality of rows; each picture element comprising opposite electrodes, a layer of a ferroelectric liquid crystal having a volume resistivity of 1x10 9 Ω.cm or larger disposed between the opposite electrodes and having a first orientation state and a second orientation state, and an insulating layer disposed on at least one of the opposite electrodes; said driving method comprising: applying row by row, sequentially and selectively to the picture elements a first writing signal for orienting the ferroelectric liquid crystal to the first orientation state and a second writing signal for orienting the ferroelectric liquid crystal to the second orientation state, and applying an alternating voltage for preventing reversal phenomenon to the picture elements during a period when said writing signals are not applied to the picture elements concerned.
Claim 20
Dependent Claim
146 words
A driving method for a liquid crystal device comprising a plurality of picture elements arranged in a plurality of rows; each picture element comprising opposite electrodes, a layer of a ferroelectric liquid crystal having a volume resistivity of 1x10 9 Ω.cm or larger disposed between the opposite electrodes and having a first orientation state and a second orientation state, and an insulating layer disposed on at least one of the opposite electrodes; said driving method comprising: applying row by row, sequentially and selectively to the picture elements a first writing signal for orienting the ferroelectric liquid crystal to the first orientation state and a second writing signal for orienting the ferroelectric liquid crystal to the second orientation state, and applying an alternating voltage for preventing reversal phenomenon to the picture elements during a period when said writing signals are not applied to the picture elements concerned.
Claim 21
Dependent Claim
23 words
A driving method according to claim 18 wherein said first and second signals are applied in different phases and have mutually opposite polarities.
Claim 22
Dependent Claim
124 words
A driving method for a liquid crystal device comprising a plurality of picture elements arranged two-dimensionally; each picture element comprising opposite electrodes, a layer of a ferroelectric liquid crystal having a volume resistivity of 1x10 9 it.cm or larger and disposed between the opposite electrodes and having a first display state and a second display state; said driving method comprising: applying a first writing signal of a polarity for producing a first display state and a holding signal of a reverse polarity for holding the first display state respectively to a selected first group of picture elements among said plurality of picture elements, and applying a second writing signal for producing a second display state respectively to a remaining second group of picture elements.
Claim 23
Dependent Claim
124 words
A driving method for a liquid crystal device comprising a plurality of picture elements arranged two-dimensionally; each picture element comprising opposite electrodes, a layer of a ferroelectric liquid crystal having a volume resistivity of 1x10 9 it.cm or larger and disposed between the opposite electrodes and having a first display state and a second display state; said driving method comprising: applying a first writing signal of a polarity for producing a first display state and a holding signal of a reverse polarity for holding the first display state respectively to a selected first group of picture elements among said plurality of picture elements, and applying a second writing signal for producing a second display state respectively to a remaining second group of picture elements.
Claim 24
Dependent Claim
32 words
A driving method according to claim 20 wherein an alternating voltage for preventing reversal of display states is applied to a picture element to which said writing signals are not being applied.
Claim 25
Dependent Claim
18 words
A driving method according to claim 18, 20 or 21, wherein said alternating voltage is an AC voltage.
Claim 26
Dependent Claim
27 words
A driving method according to claim 18 or claim 20 wherein said ferroelectric liquid crystal has a volume resistivity of 1x10 10 Ω.cm to 1x10 13 Ω.cm.
Claim 27
Dependent Claim
27 words
A driving method according to claim 18 or claim 20 wherein said ferroelectric liquid crystal has a volume resistivity of 1x10 11 Ω.cm to 1x10 13 Ω.cm.
Claim 28
Dependent Claim
27 words
A driving method according to claim 18 or claim 20 wherein said ferroelectric liquid crystal has a volume resistivity of 1x10 12 Ωcm to 1x10 13 Ω.cm.
Claim 29
Dependent Claim
21 words
A driving method according to claim 18 or claim 20 wherein said ferroelectric liquid crystal state is placed under bistability condition.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.