Patent US4709995A successfully refreshed from Google Patents.
US4709995A
Expired / Lapsed
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Ferroelectric display panel and driving method therefor to achieve gray scale
Assignee: Canon Inc
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Filing: 1985-08-07
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Granted: 1987-12-01
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Expires: 2005-08-07
Abstract
Abstract A display panel comprising a liquid crystal device comprising a plurality of picture elements arranged in a plurality of rows and columns, each picture element comprising a ferroelectric crystal under bistability condition showing either a first or a second orientation state; means for orienting the ferroelectric liquid crystal to either one of the first and second orientation states at respective picture elements; and means for controlling the duration of the first or second orientation state at respective picture elements.
Inventors
- 👤 Masaki Kuribayashi
- 👤 Toshihiko Nakazawa
- 👤 Junichiro Kanbe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 12:16
CPC Classifications
G; G09; G09G; G09G3/00; G09G3/20; G09G3/34; G09G3/36; G09G3/3611; G09G3/3622; G09G3/3629; H; H04; H04N; H04N3/00; H04N3/10; H04N3/12; H04N3/127; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/1333; G02F1/1343; G02F1/134309; G02F1/134336; G02F1/137; G02F1/139; G02F1/141; G02F2203/00; G02F2203/30; G09G2310/00; G09G2310/02; G09G2310/0202; G09G2310/0205; G09G2310/06; G09G2310/061; G09G2320/00; G09G2320/02; G09G2320/0204; G09G3/2007; G09G3/2018; G09G3/3614
Claims Analysis
Total Claims: 79
Claim 1
Independent Claim
80 words
A display panel, comprising: a liquid crystal device comprising a plurality of picture elements arranged in a plurality of rows and columns, each picture element comprising a ferroelectric crystal under bistability condition showing either a first or a second orientation state, means for orienting the ferroelectric liquid crystal to either one of the first and second orientation states at respective picture elements, and duration-controlling means for controlling the duration of the first or second orientation state at respective picture elements.
Claim 2
Dependent Claim
80 words
A display panel, comprising: a liquid crystal device comprising a plurality of picture elements arranged in a plurality of rows and columns, each picture element comprising a ferroelectric crystal under bistability condition showing either a first or a second orientation state, means for orienting the ferroelectric liquid crystal to either one of the first and second orientation states at respective picture elements, and duration-controlling means for controlling the duration of the first or second orientation state at respective picture elements.
Claim 3
Dependent Claim
28 words
The display panel according to claim 1, wherein said ferroelectric liquid crystal under bistability condition is a liquid crystal of a chiral smectic phase having a non-spiral structure.
Claim 4
Dependent Claim
27 words
The display panel according to claim 2, wherein said chiral smectic phase is a chiral smectic C phase, H phase, J phase, F phase or G phase.
Claim 5
Dependent Claim
45 words
The display panel according to claim 1, wherein said duration-controlling means comprises means for controlling the duration of the first or second orientation state at respective picture elements for each of a plurality of field periods comprised of a frame period for displaying one picture.
Claim 6
Dependent Claim
22 words
The display panel according to claim 4, wherein said frame period is divided into a plurality of field periods having different periods.
Claim 7
Dependent Claim
34 words
The display panel according to claim 5, wherein said frame period is divided into n+1 field periods having duration ratios of 1:2:4: . . . 2 n , wherein n is a positive integer.
Claim 8
Dependent Claim
24 words
The display panel according to claim 4, wherein said frame period is divided into a plurality of field periods respectively having the same duration.
Claim 9
Dependent Claim
101 words
A display panel, comprising: a liquid crystal device comprising a plurality of picture elements arranged in a plurality of rows and columns, each picture element comprising a ferroelectric crystal under bistability condition showing either a first or a second orientation state, signal-application means for applying signals comprising a first signal for orienting the ferroelectric liquid crystal to the first orientation state and a second signal for orienting the ferroelectric liquid crystal to the second orientation state at respective picture elements on a row, and duration-controlling means for controlling the duration of the first or second orientation state at respective picture elements.
Claim 10
Dependent Claim
101 words
A display panel, comprising: a liquid crystal device comprising a plurality of picture elements arranged in a plurality of rows and columns, each picture element comprising a ferroelectric crystal under bistability condition showing either a first or a second orientation state, signal-application means for applying signals comprising a first signal for orienting the ferroelectric liquid crystal to the first orientation state and a second signal for orienting the ferroelectric liquid crystal to the second orientation state at respective picture elements on a row, and duration-controlling means for controlling the duration of the first or second orientation state at respective picture elements.
Claim 11
Dependent Claim
20 words
The display panel according to claim 8, wherein said first and second signals have mutually opposite directions of electric field.
Claim 12
Dependent Claim
17 words
The display panel according to claim 8, wherein said first and second signals have mutually opposite polarities.
Claim 13
Dependent Claim
60 words
The display panel according to claim 8, wherein said signal-application means applies said first signal to a selected first group of picture elements on a row at a first phase and said second signal to the remaining second group of picture elements on the same row at a second phase, said first and second signals being applied row by row.
Claim 14
Dependent Claim
20 words
The display panel according to claim 11, wherein said first and second phases are different in time from each other.
Claim 15
Dependent Claim
19 words
The display panel according to claim 12, wherein said second signal is applied after said first signal is applied.
Claim 16
Dependent Claim
89 words
The display panel according to claim 8, wherein said signal-application means applies said first signal to the whole or a part of the picture elements on a row to clear the picture elements by orienting the ferroelectric liquid crystal thereat to the first orientation state, and said second signal to a selected picture element among the cleared picture elements to write in the selected picture element by orienting the ferroelectric liquid crystal thereat to the second orientation state, said first and second signals being sequentially applied row by row.
Claim 17
Dependent Claim
67 words
The display panel according to claim 8, wherein said signal-application means applies said first signal to the whole or a part of the picture elements on a row ((N+1)th row) subsequent to a writing row (Nth row) at a first phase, and said second signal to a selected picture element on the writing row (Nth row), said first and second signals being respectively applied row by row.
Claim 18
Dependent Claim
18 words
The display panel according to claim 15, wherein said first and second phases are simultaneous with each other.
Claim 19
Dependent Claim
45 words
The display panel according to claim 8, wherein said duration-controlling means comprises means for controlling the duration of the first or second orientation state at respective picture elements for each of a plurality of field periods comprised of a frame period for displaying one picture.
Claim 20
Dependent Claim
22 words
The display panel according to claim 17, wherein said frame period is divided into a plurality of field periods having different periods.
Claim 21
Dependent Claim
34 words
The display panel according to claim 18, wherein said frame period is divided into n+1 field periods having duration ratios of 1:2:4: . . . 2 n , wherein n is a positive integer.
Claim 22
Dependent Claim
24 words
The display panel according to claim 17, wherein said frame period is divided into a plurality of field periods respectively having the same duration.
Claim 23
Dependent Claim
137 words
A display panel, comprising: a liquid crystal device comprising a plurality of picture elements arranged in a plurality of rows and columns, each picture element comprising a ferroelectric crystal under bistability condition showing either a first or a second orientation state, signal-application means for applying a first signal for orienting the ferroelectric liquid crystal to the first orientation state picture elements constituting the whole or a part of a picture thereby to clear the picture elements, and a second signal for orienting the ferroelectric liquid crystal to the second orientation state a selected picture element among the cleared picture elements to write a display state based on the second orientation state, said second signal being applied row by row, and duration-controlling means for controlling the duration of the first or second orientation state at respective picture elements.
Claim 24
Dependent Claim
137 words
A display panel, comprising: a liquid crystal device comprising a plurality of picture elements arranged in a plurality of rows and columns, each picture element comprising a ferroelectric crystal under bistability condition showing either a first or a second orientation state, signal-application means for applying a first signal for orienting the ferroelectric liquid crystal to the first orientation state picture elements constituting the whole or a part of a picture thereby to clear the picture elements, and a second signal for orienting the ferroelectric liquid crystal to the second orientation state a selected picture element among the cleared picture elements to write a display state based on the second orientation state, said second signal being applied row by row, and duration-controlling means for controlling the duration of the first or second orientation state at respective picture elements.
Claim 25
Dependent Claim
29 words
The display panel according to claim 21, wherein said first signal is applied row by row to the picture elements constituting said whole or a part of a picture.
Claim 26
Dependent Claim
39 words
The display panel according to claim 21, wherein said duration-controlling means comprises means for controlling the duration of the second orientation state for each of a plurality of field periods comprised of a frame period for displaying one picture.
Claim 27
Dependent Claim
22 words
The display panel according to claim 23, wherein said frame period is divided into a plurality of field periods having different periods.
Claim 28
Dependent Claim
34 words
The display panel according to claim 24, wherein said frame period is divided into n+1 field periods having duration ratios of 1:2:4: . . . 2 n , wherein n is a positive integer.
Claim 29
Dependent Claim
24 words
The display panel according to claim 23, wherein said frame period is divided into a plurality of field periods respectively having the same duration.
Claim 30
Dependent Claim
142 words
A display panel, comprising: a liquid crystal device comprising a plurality of picture elements arranged in a plurality of rows and columns, each picture element comprising a ferroelectric crystal under bistability condition having a first orientation state and a second orientation state, writing means for writing a display state based on the first orientation state of the ferroelectric liquid crystal in a selected first group of picture elements row by row on the whole or a part of a picture in a first stage, and writing a display state based on the second orientation state of the ferroelectric liquid crystal in a selected second group of picture elements row by row on the whole or a part of a picture in a second stage, and duration-controlling means for controlling the duration of the first or second orientation state at respective picture elements.
Claim 31
Dependent Claim
142 words
A display panel, comprising: a liquid crystal device comprising a plurality of picture elements arranged in a plurality of rows and columns, each picture element comprising a ferroelectric crystal under bistability condition having a first orientation state and a second orientation state, writing means for writing a display state based on the first orientation state of the ferroelectric liquid crystal in a selected first group of picture elements row by row on the whole or a part of a picture in a first stage, and writing a display state based on the second orientation state of the ferroelectric liquid crystal in a selected second group of picture elements row by row on the whole or a part of a picture in a second stage, and duration-controlling means for controlling the duration of the first or second orientation state at respective picture elements.
Claim 32
Dependent Claim
45 words
The display panel according to claim 27, wherein said duration-controlling means comprises means for controlling the duration of the first or second orientation state at respective picture elements for each of a plurality of field periods comprised of a frame period for displaying one picture.
Claim 33
Dependent Claim
22 words
The display panel according to claim 28, wherein said frame period is divided into a plurality of field periods having different periods.
Claim 34
Dependent Claim
34 words
The display panel according to claim 29, wherein said frame period is divided into n+1 field periods having duration ratios of 1:2:4: . . . 2 n , wherein n is a positive integer.
Claim 35
Dependent Claim
24 words
The display panel according to claim 28, wherein said frame period is divided into a plurality of field periods respectively having the same duration.
Claim 36
Dependent Claim
40 words
In a method for driving a display panel of the type comprising a plurality of picture elements arranged two-dimensionally; the improved method comprising controlling display duty in a unit time period for each picture element thereby to provide a gradation.
Claim 37
Dependent Claim
40 words
In a method for driving a display panel of the type comprising a plurality of picture elements arranged two-dimensionally; the improved method comprising controlling display duty in a unit time period for each picture element thereby to provide a gradation.
Claim 38
Dependent Claim
39 words
The method according to claim 32, wherein each picture element comprises a pair of opposite electrodes, and a ferroelectric liquid crystal interposed between the opposite electrodes and placed under bistability condition showing either a first or second orientation state.
Claim 39
Dependent Claim
27 words
The method according to claim 33, wherein said ferroelectric liquid crystal under bistability condition is a liquid crystal of a chiral smectic phase having a non-spiral structure.
Claim 40
Dependent Claim
26 words
The method according to claim 34, wherein said chiral smectic phase is a chiral smectic C phase, H phase, I phase, F phase or G phase.
Claim 41
Dependent Claim
36 words
The method according to claim 32, wherein said display duty in a unit time period is the ratio of a field period providing a bright or dark state to a frame period for displaying one picture.
Claim 42
Dependent Claim
82 words
In a method for driving a display panel of the type comprising a plurality of picture elements arranged in a plurality of rows and columns, each picture element comprising a ferroelectric liquid crystal under bistability condition showing either a first or a second orientation state, either one of the first and second orientation states being written in respective picture elements to effect a display; the improved method comprising controlling the duration of the first or second orientation state at respective picture elements.
Claim 43
Dependent Claim
82 words
In a method for driving a display panel of the type comprising a plurality of picture elements arranged in a plurality of rows and columns, each picture element comprising a ferroelectric liquid crystal under bistability condition showing either a first or a second orientation state, either one of the first and second orientation states being written in respective picture elements to effect a display; the improved method comprising controlling the duration of the first or second orientation state at respective picture elements.
Claim 44
Dependent Claim
35 words
The method according to claim 37, wherein the duration of the first or second orientation state is controlled for each of a plurality of field periods comprised of a frame period for displaying one picture.
Claim 45
Dependent Claim
15 words
The method according to claim 38, wherein said plurality of field periods have different periods.
Claim 46
Dependent Claim
33 words
The method according to claim 39, wherein said frame period is divided into n+1 field periods having duration ratios of 1:2:4: . . . :2 n , wherein n is a positive integer.
Claim 47
Dependent Claim
16 words
The method accordin9 to claim 38, wherein said plurality of field periods have the same duration.
Claim 48
Dependent Claim
131 words
In a method for driving a display panel of the type comprising a plurality of picture elements arranged in a plurality of rows and columns, each picture element comprising a ferroelectric liquid crystal under bistability condition showing either a first or a second orientation state, either one of the first and second orientation states being written in respective picture elements to effect a display; the improvement comprising: applying row by row a first signal for orienting the ferroelectric liquid crystal to the first orientation state at a selected picture element on a row and a second signal for orienting the ferroelectric liquid crystal to the second orientation state at the remaining picture elements on the row, and controlling the duration of the first or second orientation state at respective picture elements.
Claim 49
Dependent Claim
131 words
In a method for driving a display panel of the type comprising a plurality of picture elements arranged in a plurality of rows and columns, each picture element comprising a ferroelectric liquid crystal under bistability condition showing either a first or a second orientation state, either one of the first and second orientation states being written in respective picture elements to effect a display; the improvement comprising: applying row by row a first signal for orienting the ferroelectric liquid crystal to the first orientation state at a selected picture element on a row and a second signal for orienting the ferroelectric liquid crystal to the second orientation state at the remaining picture elements on the row, and controlling the duration of the first or second orientation state at respective picture elements.
Claim 50
Dependent Claim
19 words
The method according to claim 42, wherein said first and second signals are applied in different phases of time.
Claim 51
Dependent Claim
15 words
The method according to claim 42, wherein said first and second signals are applied sequentially.
Claim 52
Dependent Claim
35 words
The method according to claim 42, wherein the duration of the first or second orientation state is controlled for each of a plurality of field periods comprised of a frame period for displaying one picture.
Claim 53
Dependent Claim
15 words
The method according to claim 45, wherein said plurality of field periods have different periods.
Claim 54
Dependent Claim
33 words
The method according to claim 46, wherein said frame period is divided into n+1 field periods having duration ratios of 1:2:4: . . . :2 n , wherein n is a positive integer.
Claim 55
Dependent Claim
16 words
The method according to claim 42, wherein said plurality of field periods have the same duration.
Claim 56
Dependent Claim
146 words
In a method for driving a display panel of the type comprising a plurality of picture elements arranged in a plurality of rows and columns, each picture element comprising a ferroelectric liquid crystal under bistability condition showing either a first or a second orientation state, either one of the first and second orientation states being written in respective picture elements to effect a display; the improvement comprising: applying row by row a first signal for orienting the ferroelectric liquid crystal to the first orientation state at the whole or a part of the picture elements on a row to clear the picture elements and a second signal for orienting the ferroelectric liquid crystal to the second orientation state at a selected picture element among the cleared picture elements on the row, and controlling the duration of the first or second orientation state at respective picture elements.
Claim 57
Dependent Claim
146 words
In a method for driving a display panel of the type comprising a plurality of picture elements arranged in a plurality of rows and columns, each picture element comprising a ferroelectric liquid crystal under bistability condition showing either a first or a second orientation state, either one of the first and second orientation states being written in respective picture elements to effect a display; the improvement comprising: applying row by row a first signal for orienting the ferroelectric liquid crystal to the first orientation state at the whole or a part of the picture elements on a row to clear the picture elements and a second signal for orienting the ferroelectric liquid crystal to the second orientation state at a selected picture element among the cleared picture elements on the row, and controlling the duration of the first or second orientation state at respective picture elements.
Claim 58
Dependent Claim
35 words
The method according to claim 49, wherein the duration of the first or second orientation state is controlled for each of a plurality of field periods comprised of a frame period for displaying one picture.
Claim 59
Dependent Claim
15 words
The method according to claim 50, wherein said plurality of field periods have different periods.
Claim 60
Dependent Claim
33 words
The method according to claim 51, wherein said frame period is divided into n+1 field periods having duration ratios of 1:2:4: . . . :2 n , wherein n is a positive integer.
Claim 61
Dependent Claim
16 words
The method according to claim 50, wherein said plurality of field periods have the same duration.
Claim 62
Dependent Claim
157 words
In a method for driving a display panel of the type comprising a plurality of picture elements arranged in a plurality of rows and columns, each picture element comprising a ferroelectric liquid crystal under bistability condition showing either a first or a second orientation state, either one of the first and second orientation states being written in respective picture elements to effect a display; the improvement comprising: applying row by row a first signal for orienting the ferroelectric liquid crystal to the first orientation state at the whole or a part of the picture elements on a row ((N+1)th row) subsequent to a writing row (Nth row) to clear the picture elements and a second signal for orienting the ferroelectric liquid crystal to the second orientation state at a selected picture element among the cleared elements on the writing row (Nth row), and controlling the duration of the first or second orientation state at respective picture elements.
Claim 63
Dependent Claim
157 words
In a method for driving a display panel of the type comprising a plurality of picture elements arranged in a plurality of rows and columns, each picture element comprising a ferroelectric liquid crystal under bistability condition showing either a first or a second orientation state, either one of the first and second orientation states being written in respective picture elements to effect a display; the improvement comprising: applying row by row a first signal for orienting the ferroelectric liquid crystal to the first orientation state at the whole or a part of the picture elements on a row ((N+1)th row) subsequent to a writing row (Nth row) to clear the picture elements and a second signal for orienting the ferroelectric liquid crystal to the second orientation state at a selected picture element among the cleared elements on the writing row (Nth row), and controlling the duration of the first or second orientation state at respective picture elements.
Claim 64
Dependent Claim
35 words
The method according to claim 54, wherein the duration of the first or second orientation state is controlled for each of a plurality of field periods comprised of a frame period for displaying one picture.
Claim 65
Dependent Claim
15 words
The method according to claim 55, wherein said plurality of field periods have different periods.
Claim 66
Dependent Claim
33 words
The method according to claim 56, wherein said frame period is divided into n+1 field periods having duration ratios of 1:2:4: . . . :2 n , wherein n is a positive integer.
Claim 67
Dependent Claim
16 words
The method according to claim 55, wherein said plurality of field periods have the same duration.
Claim 68
Dependent Claim
140 words
In a method for driving a display panel of the type comprising a plurality of picture elements arranged in a plurality of rows and columns, each picture element comprising a ferroelectric liquid crystal under bistability condition showing either a first or a second orientation state, either one of the first and second orientation states being written in respective picture elements to effect a display; the improvement comprising: applying a first signal for orienting the ferroelectric liquid crystal to the first orientation state to picture elements constituting the whole or a part of a picture thereby to clear the picture elements, and a second signal for orienting the ferroelectric liquid crystal to the second orientation state to a selected picture element among the cleared picture elements, and controlling the duration of the first or second orientation state at respective picture elements.
Claim 69
Dependent Claim
140 words
In a method for driving a display panel of the type comprising a plurality of picture elements arranged in a plurality of rows and columns, each picture element comprising a ferroelectric liquid crystal under bistability condition showing either a first or a second orientation state, either one of the first and second orientation states being written in respective picture elements to effect a display; the improvement comprising: applying a first signal for orienting the ferroelectric liquid crystal to the first orientation state to picture elements constituting the whole or a part of a picture thereby to clear the picture elements, and a second signal for orienting the ferroelectric liquid crystal to the second orientation state to a selected picture element among the cleared picture elements, and controlling the duration of the first or second orientation state at respective picture elements.
Claim 70
Dependent Claim
35 words
The method according to claim 59, wherein the duration of the first or second orientation state is controlled for each of a plurality of field periods comprised of a frame period for displaying one picture.
Claim 71
Dependent Claim
15 words
The method according to claim 60, wherein said plurality of field periods have different periods.
Claim 72
Dependent Claim
33 words
The method according to claim 61, wherein said frame period is divided into n+1 field periods having duration ratios of 1:2:4: . . . :2 n , wherein n is a positive integer.
Claim 73
Dependent Claim
16 words
The method according to claim 60, wherein said plurality of field periods have the same duration.
Claim 74
Dependent Claim
160 words
In a xethod for driving a display panel of the type comprising a plurality of picture elements arranged in a plurality of rows and columns, each picture element comprising a ferroelectric liquid crystal under bistability condition showing either a first or a second orientation state, either one of the first and second orientation states being written in respective picture elements to effect a display; the improvement comprising: applying a first signal for orienting the ferroelectric liquid crystal to the first orientation state to a selected first group of picture elements row by row on the whole or a part of a picture in a first stage, applying a second signal for orienting the ferroelectric liquid crystal to the second orientation state to a selected second group of picture elements row by row on the whole or a part of a picture in a second stage, and controlling the duration of the first or second orientation state at respective picture elements.
Claim 75
Dependent Claim
160 words
In a xethod for driving a display panel of the type comprising a plurality of picture elements arranged in a plurality of rows and columns, each picture element comprising a ferroelectric liquid crystal under bistability condition showing either a first or a second orientation state, either one of the first and second orientation states being written in respective picture elements to effect a display; the improvement comprising: applying a first signal for orienting the ferroelectric liquid crystal to the first orientation state to a selected first group of picture elements row by row on the whole or a part of a picture in a first stage, applying a second signal for orienting the ferroelectric liquid crystal to the second orientation state to a selected second group of picture elements row by row on the whole or a part of a picture in a second stage, and controlling the duration of the first or second orientation state at respective picture elements.
Claim 76
Dependent Claim
35 words
The method according to claim 64, wherein the duration of the first or second orientation state is controlled for each of a plurality of field periods comprised of a frame period for displaying one picture.
Claim 77
Dependent Claim
15 words
The method according to claim 65, wherein said plurality of field periods have different periods.
Claim 78
Dependent Claim
33 words
The method according to claim 66, wherein said frame period is divided into n+1 field periods having duration ratios of 1:2:4: . . . :2 n , wherein n is a positive integer.
Claim 79
Dependent Claim
16 words
The method according to claim 65, wherein said plurality of field periods have the same duration.
References Cited (Backward Citations)
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