US5699074A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Addressing device and method for rapid video response in a bistable liquid crystal display
Assignee: Symbol Technologies LLC
•
Filing: 1995-03-24
•
Granted: 1997-12-16
•
Expires: 2015-03-24
Abstract
Abstract A front-lit, non-gray scale liquid crystal display device (10) including a polymer stabilized cholesteric liquid crystalline material has two optical states stable in the absence of an electric field. In a reflecting optical state incident illumination is directly reflected by the liquid crystal, producing a light pixel. In a scattering optical state incident illumination is absorbed by a black surface on the rear of the display, producing a dark pixel. A method employing a plurality of display control signals having the same polarity and differing phase relationships permits the fast video response of the display, notwithstanding that the average time to switch from a scattering optical state to a reflecting optical state is about 30 milliseconds, requiring about fifteen seconds to update a typical 480-row liquid crystal display using conventional array sequencing techniques. Several routines are presented for determining when to update such a display for a variety of applications.
Inventors
- 👤 Jeffrey W. Sutherland
- 👤 Timothy P. O'Hagan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 20:00
CPC Classifications
G; G06; G06F; G06F1/00; G06F1/16; G06F1/1613; G06F1/1633; G06F1/1637; G06F1/1626; G09; G09G; G09G3/00; G09G3/20; G09G3/34; G09G3/36; G09G3/3611; G09G3/3622; G09G3/3629; G09G2300/00; G09G2300/04; G09G2300/0469; G09G2300/0478; G09G2300/0482; G09G2300/0486; G09G2310/00; G09G2310/04; G09G2310/06
Claims Analysis
Total Claims: 41
Claim 1
Independent Claim
111 words
A method for modifying a liquid crystal display comprised of an array of pixels arranged in a plurality of rows and a plurality of columns, said pixels have a first optical state and a second optical state, both optical states stable in the absence of an electric field, wherein control signals are applied to the array of pixels to modify the optical state thereof, said method comprising: simultaneously applying selective control signals to the plurality of rows having pixels requiting a change to the first optical state; and sequentially applying selective control signals to one or more rows of pixels having at least one pixel requiring a change in optical state.
Claim 2
Independent Claim
111 words
A method for modifying a liquid crystal display comprised of an array of pixels arranged in a plurality of rows and a plurality of columns, said pixels have a first optical state and a second optical state, both optical states stable in the absence of an electric field, wherein control signals are applied to the array of pixels to modify the optical state thereof, said method comprising: simultaneously applying selective control signals to the plurality of rows having pixels requiting a change to the first optical state; and sequentially applying selective control signals to one or more rows of pixels having at least one pixel requiring a change in optical state.
Claim 3
Dependent Claim
20 words
A method according to claim 1, wherein said first optical state is reflecting and said second optical state is scattering.
Claim 4
Dependent Claim
49 words
A method according to claim 1, wherein said array of pixels includes a plurality of row conductors respectively associated with rows of pixels, and a plurality of column conductors respectively associated with columns of pixels, said plurality of row and column conductors selectively applying a voltage across each pixel.
Claim 5
Dependent Claim
72 words
A method according to claim 3, wherein said step of simultaneously applying selective control signals includes the steps of: applying a select row signal to every row conductor associated with a row having at least one pixel requiring a change from a scattering optical state to a reflecting optical state; and applying a reflect signal to each column conductor associated with a pixel that is to be in a reflecting optical state.
Claim 6
Dependent Claim
108 words
A method according to claim 3, wherein step of sequentially applying selective control signals includes the steps of: applying a select row signal to the row conductor associated with a select row having at least one pixel requiring a change in optical state; applying a non-select row signal to the row conductors associated with the remaining rows; applying a reflect signal to each column conductor associated with a pixel in said select row that is to be in the reflecting optical state; and applying a scatter signal to each column conductor associated with a pixel in said select row that is to be in the scattering optical state.
Claim 7
Dependent Claim
44 words
A method according to claim 1, wherein one of said control signals has a first phase differing from that of all other of said control signals and a first polarity the same as that of all other of said plurality of said control signals.
Claim 8
Dependent Claim
12 words
A method according to claim 1, wherein said control signals are squarewaves.
Claim 9
Dependent Claim
23 words
A method according to claim 1, wherein said control signals provide the appropriate voltages to the liquid crystal to control its optical state.
Claim 10
Dependent Claim
16 words
A method according to claim 1, wherein said liquid crystal is a polymer stabilized liquid crystal.
Claim 11
Dependent Claim
24 words
A method according to claim 9, wherein said control signals provide appropriate voltages to the polymer stabilized liquid crystal to control its optical state.
Claim 12
Dependent Claim
116 words
A display device comprising: display means including an array of pixels arranged in a plurality of rows and a plurality of columns, said pixels have a first optical state and a second optical state, both optical states stable in the absence of an electric field; and control means for generating a plurality of control signals for application to the array of pixels to modify the optical state thereof, said control means simultaneously applying selective control signals to the plurality of rows having pixels requiting a change to the first optical state, and thereafter sequentially applying selective control signals to one or more rows of pixels having at least one pixel requiring a change in optical state.
Claim 13
Dependent Claim
116 words
A display device comprising: display means including an array of pixels arranged in a plurality of rows and a plurality of columns, said pixels have a first optical state and a second optical state, both optical states stable in the absence of an electric field; and control means for generating a plurality of control signals for application to the array of pixels to modify the optical state thereof, said control means simultaneously applying selective control signals to the plurality of rows having pixels requiting a change to the first optical state, and thereafter sequentially applying selective control signals to one or more rows of pixels having at least one pixel requiring a change in optical state.
Claim 14
Dependent Claim
21 words
A display device according to claim 11, wherein said first optical state is reflecting and said second optical state is scattering.
Claim 15
Dependent Claim
50 words
A display device according to claim 11, wherein said array of pixels includes a plurality of row conductors respectively associated with rows of pixels, and a plurality of column conductors respectively associated with columns of pixels, said plurality of row and column conductors selectively applying a voltage across each pixel.
Claim 16
Dependent Claim
49 words
A display device according to claim 11, wherein one of said plurality of control signals has a first phase differing from that of all other of said plurality of control signals and a first polarity the same as that of all other of said plurality of said control signals.
Claim 17
Dependent Claim
15 words
A display device according to claim 11, wherein said plurality of control signals are squarewaves.
Claim 18
Dependent Claim
26 words
A display device according to claim 11, wherein said plurality of control signals provide the appropriate voltages to the liquid crystal to control its optical state.
Claim 19
Dependent Claim
16 words
A display device according to claim 11, wherein said display means is a liquid crystal display.
Claim 20
Dependent Claim
18 words
A display device according to claim 17, wherein said liquid crystal display is a polymer stabilized liquid crystal.
Claim 21
Dependent Claim
22 words
A display device according to claim 11, wherein said control means generates the plurality of control signals in response to display data.
Claim 22
Dependent Claim
40 words
A display device according to claim 19, wherein said display device further comprises: processor means for generating the display data to display information on said display means; and memory means for storing the display data generated by the processor means.
Claim 23
Dependent Claim
15 words
A display device according to claim 19, wherein said control means includes display driver means.
Claim 24
Independent Claim
185 words
A method for modifying a liquid crystal display comprised of an array of pixels arranged in a plurality of rows and a plurality of colas, said pixels have a first optical state and a second optical state, both optical states stable in the absence of an electric field, wherein control signals are applied to the array of pixels to modify the optical state thereof, said method comprising: determining a number of rows having pixels requiring a change in optical state; and determining whether the number of rows has reached a threshold value, wherein: (a) if the number of rows has not reached the threshold value, sequentially applying selective control signals to one or more rows of pixels having at least one pixel requiring a change in optical state, and (b) if the number of rows has reached the threshold value, simultaneously applying selective control signals to the plurality of rows having pixels requiring a change to the first optical state, and thereafter sequentially applying selective control signals to one or more rows of pixels having at least one pixel requiring a change in optical state.
Claim 25
Independent Claim
185 words
A method for modifying a liquid crystal display comprised of an array of pixels arranged in a plurality of rows and a plurality of colas, said pixels have a first optical state and a second optical state, both optical states stable in the absence of an electric field, wherein control signals are applied to the array of pixels to modify the optical state thereof, said method comprising: determining a number of rows having pixels requiring a change in optical state; and determining whether the number of rows has reached a threshold value, wherein: (a) if the number of rows has not reached the threshold value, sequentially applying selective control signals to one or more rows of pixels having at least one pixel requiring a change in optical state, and (b) if the number of rows has reached the threshold value, simultaneously applying selective control signals to the plurality of rows having pixels requiring a change to the first optical state, and thereafter sequentially applying selective control signals to one or more rows of pixels having at least one pixel requiring a change in optical state.
Claim 26
Dependent Claim
49 words
A method according to claim 22, wherein said array of pixels includes a plurality of row conductors respectively associated with rows of pixels, and a plurality of column conductors respectively associated with columns of pixels, said plurality of row and column conductors selectively applying a voltage across each pixel.
Claim 27
Dependent Claim
120 words
A method according to claim 23, wherein step (a) of sequentially applying selective control signals includes the steps of: applying a select row signal to the row conductor associated with a row having at least one pixel requiring a change in optical state; applying a non-select row signal to the row conductors associated with the remaining rows; applying a reflect signal to each column conductor associated with a pixel in said row having at least one pixel requiring a change in optical state, wherein the change in optical state is to reflecting; and applying a scatter signal to each column conductor associated with the remaining pixels in said row having at least one pixel requiting a change in optical state.
Claim 28
Dependent Claim
72 words
A method according to claim 23, wherein step (b) of simultaneously applying selective control signals includes the steps of: applying a select row signal to every row conductor associated with a row having at least one pixel requiring a change from a scattering optical state to a reflecting optical state; and applying a reflect signal to each column conductor associated with a pixel that is to be in a reflecting optical state.
Claim 29
Dependent Claim
109 words
A method according to claim 23, wherein step (b) of sequentially applying selective control signals includes the steps of: applying a select row signal to the row conductor associated with a select row having at least one pixel requiring a change in optical state; applying a non-select row signal to the row conductors associated with the remaining rows; applying a reflect signal to each column conductor associated with a pixel in said select row that is to be in the reflecting optical state; and applying a select signal to each column conductor associated with a pixel in said select row that is to be in the scattering optical state.
Claim 30
Dependent Claim
189 words
A display device comprising: display means including an array of pixels arranged in a plurality of rows and a plurality of columns, said pixels have a first optical state and a second optical state, both optical states stable in the absence of an electric field; means for determining a number of rows having pixels requiring a change in optical state; means for determining whether the number of rows has reached a threshold value; and control means for generating a plurality of control signals for application to the array of pixels to modify the optical state thereof, wherein: (a) if the number of rows has not reached the threshold value, sequentially applying selective control signals to one or more rows of pixels having at least one pixel requiring a change in optical state, and (b) if the number of rows has reached the threshold value, simultaneously applying selective control signals to the plurality of rows having pixels requiting a change to the first optical state, and thereafter sequentially applying selective control signals to one or more rows of pixels having at least one pixel requiring a change in optical state.
Claim 31
Dependent Claim
189 words
A display device comprising: display means including an array of pixels arranged in a plurality of rows and a plurality of columns, said pixels have a first optical state and a second optical state, both optical states stable in the absence of an electric field; means for determining a number of rows having pixels requiring a change in optical state; means for determining whether the number of rows has reached a threshold value; and control means for generating a plurality of control signals for application to the array of pixels to modify the optical state thereof, wherein: (a) if the number of rows has not reached the threshold value, sequentially applying selective control signals to one or more rows of pixels having at least one pixel requiring a change in optical state, and (b) if the number of rows has reached the threshold value, simultaneously applying selective control signals to the plurality of rows having pixels requiting a change to the first optical state, and thereafter sequentially applying selective control signals to one or more rows of pixels having at least one pixel requiring a change in optical state.
Claim 32
Dependent Claim
21 words
A display device according to claim 27, wherein said first optical state is reflecting and said second optical state is scattering.
Claim 33
Dependent Claim
50 words
A display device according to claim 27, wherein said array of pixels includes a plurality of row conductors respectively associated with rows of pixels, and a plurality of column conductors respectively associated with columns of pixels, said plurality of row and column conductors selectively applying a voltage across each pixel.
Claim 34
Dependent Claim
49 words
A display device according to claim 27, wherein one of said plurality of control signals has a first phase differing from that of all other of said plurality of control signals and a first polarity the same as that of all other of said plurality of said control signals.
Claim 35
Dependent Claim
15 words
A display device according to claim 27, wherein said plurality of control signals are squarewaves.
Claim 36
Dependent Claim
26 words
A display device according to claim 27, wherein said plurality of control signals provide the appropriate voltages to the liquid crystal to control its optical state.
Claim 37
Dependent Claim
16 words
A display device according to claim 27, wherein said display means is a liquid crystal display.
Claim 38
Dependent Claim
18 words
A display device according to claim 33, wherein said liquid crystal display includes a polymer stabilized liquid crystal.
Claim 39
Dependent Claim
22 words
A display device according to claim 27, wherein said control means generates the plurality of control signals in response to display data.
Claim 40
Dependent Claim
40 words
A display device according to claim 35, wherein said display device further comprises: processor means for generating the display data to display information on said display means; and memory means for storing the display data generated by the processor means.
Claim 41
Dependent Claim
15 words
A display device according to claim 27, wherein said control means includes display driver means.
References Cited (Backward Citations)
US5296953A
Cited
US4908613A
Cited
US4901066A
Cited
US4870398A
Cited
US5506600A
Cited
US5250789A
Cited
US5251048A
Cited
US5570216A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2000-12-15 | 2001-06-16 | 2001-12-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-12-15 | 2005-06-16 | 2005-12-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-12-15 | 2009-06-16 | 2009-12-16 | $7700.00 | Window Closed / Lapsed |