US5933203A — Apparatus for and method of driving a cholesteric…

Claim 1

Independent Claim 72 words

A method of driving at least a portion of a cholesteric liquid crystal (CLC) panel to a state having a given reflectivity, comprising the steps of: initially driving said portion to a nematic phase; subsequently driving said portion to a cholesteric phase focal-conic state, said cholesteric phase focal-conic state providing a known reference state for subsequent driving of said portion; and thereafter driving said portion to said state having said given reflectivity.

Claim 2

Independent Claim 72 words

A method of driving at least a portion of a cholesteric liquid crystal (CLC) panel to a state having a given reflectivity, comprising the steps of: initially driving said portion to a nematic phase; subsequently driving said portion to a cholesteric phase focal-conic state, said cholesteric phase focal-conic state providing a known reference state for subsequent driving of said portion; and thereafter driving said portion to said state having said given reflectivity.

Claim 3

Dependent Claim 32 words

The method of driving as recited in claim 1 wherein said step of initially driving comprises the step of applying a sequence of pulses to drive said portion to said nematic phase.

Claim 4

Dependent Claim 34 words

The method of driving as recited in claim 1 wherein said step of subsequently driving comprises the step of applying a sequence of pulses to drive said portion to said cholesteric phase focal-conic state.

Claim 5

Dependent Claim 67 words

The method of driving as recited in claim 1 wherein said step of initially driving comprises the step of applying a first sequence of pulses having a first amplitude to drive said portion to said nematic phase and said step of subsequently driving comprises the step of applying a second sequence of pulses having a second amplitude to drive said portion to said cholesteric phase focal-conic state.

Claim 6

Dependent Claim 27 words

The method of driving as recited in claim 4 wherein said first and second amplitudes are a function of a composition of CLC in said CLC panel.

Claim 7

Dependent Claim 25 words

The method of driving as recited in claim 4 wherein said first and second amplitudes are a function of a thickness of said CLC panel.

Claim 8

Dependent Claim 41 words

The method of driving as recited in claim 1 wherein said step of thereafter driving comprises the step of applying a sequence of pulses to drive said portion from said cholesteric phase focal-conic state to said state having said given reflectivity.

Claim 9

Dependent Claim 88 words

The method of driving as recited in claim 1 wherein said state having said given reflectivity is an intermediate state between said cholesteric phase focal-conic state and a cholesteric phase planar state, and wherein said step of thereafter driving said portion to said intermediate state comprises the step of applying a sequence of addressing pulses having a predetermined amplitude to drive said portion from said cholesteric phase focal-conic state to said intermediate state, said given reflectivity being a function of a duration of said sequence of addressing pulses.

Claim 10

Dependent Claim 87 words

The method of driving as recited in claim 8 wherein said step of applying a sequence of addressing pulses having a predetermined amplitude is preceded by the step of applying a first sequence of pulses having an amplitude less than a minimum amplitude necessary to drive the CLC from the focal-conic state, a duration of said first sequence of pulses adjusted such that the sum of said duration of said first sequence of pulses and said duration of said sequence of addressing pulses equals a predetermined value.

Claim 11

Dependent Claim 119 words

A driving apparatus for a cholesteric liquid crystal (CLC) panel, said driving apparatus comprising: a data circuit, couplable to said CLC panel, that selectively applies a first initialization signal and a first addressing signal to said CLC panel; and a scan circuit, couplable to said CLC panel, that selectively applies a second initialization signal and a second addressing signal to said CLC panel, said first and second initialization signals cooperating to drive a CLC in said CLC panel into a nematic phase and subsequently to drive said CLC to a cholesteric phase focal-conic state, said first and second addressing signals cooperating to selectively drive said CLC from said cholesteric phase focal-conic state to a state having a given reflectivity.

Claim 12

Dependent Claim 119 words

A driving apparatus for a cholesteric liquid crystal (CLC) panel, said driving apparatus comprising: a data circuit, couplable to said CLC panel, that selectively applies a first initialization signal and a first addressing signal to said CLC panel; and a scan circuit, couplable to said CLC panel, that selectively applies a second initialization signal and a second addressing signal to said CLC panel, said first and second initialization signals cooperating to drive a CLC in said CLC panel into a nematic phase and subsequently to drive said CLC to a cholesteric phase focal-conic state, said first and second addressing signals cooperating to selectively drive said CLC from said cholesteric phase focal-conic state to a state having a given reflectivity.

Claim 13

Dependent Claim 64 words

The driving apparatus as recited in claim 10 wherein each of said first and second initialization signals comprises a first sequence of pulses having a first amplitude and a second sequence of pulses having a second amplitude, said first sequence of pulses driving said CLC into said nematic phase and said second sequence of pulses driving said CLC to said cholesteric phase focal-conic state.

Claim 14

Dependent Claim 26 words

The driving apparatus as recited in claim 11 wherein said first amplitude and second amplitudes are a function of a composition and thickness of said CLC.

Claim 15

Dependent Claim 23 words

The driving apparatus as recited in claim 11 wherein said first and second sequence of pulses have a frequency of about 14.3 kHz.

Claim 16

Dependent Claim 34 words

The driving apparatus as recited in claim 11 wherein said first sequence of pulses has a duration of about 2 ms and said second sequence of pulses has a duration of about 4 ms.

Claim 17

Dependent Claim 52 words

The driving apparatus as recited in claim 10 wherein each of said first and second addressing signals comprises a sequence of addressing pulses having a predetermined amplitude, said driving apparatus operative to drive said CLC to said state having said given reflectivity by varying a duration of said sequence of addressing pulses.

Claim 18

Dependent Claim 23 words

The driving apparatus as recited in claim 15 wherein said predetermined amplitude is a function of a composition and thickness of said CLC.

Claim 19

Dependent Claim 23 words

The driving apparatus as recited in claim 15 wherein said first and second sequence of pulses have a frequency of about 14.3 kHz.

Claim 20

Dependent Claim 78 words

The driving apparatus as recited in claim 15 wherein said sequence of addressing pulses having a predetermined amplitude is preceded by a first sequence of pulses having an amplitude less than a minimum amplitude necessary to drive said CLC from the focal-conic state, a duration of said first sequence of pulses varied such that the sum of the duration of the first sequence of pulses and the duration of the sequence of addressing pulses has a constant value.

Claim 21

Dependent Claim 26 words

The driving apparatus as recited in claim 10 wherein said first and second initialization signals and said first and second addressing signals comprise bipolar electrical waveforms.

Claim 22

Dependent Claim 129 words

A driving apparatus for a cholesteric liquid crystal (CLC) panel having first and second electrodes coupled to opposing sides thereof, said driving apparatus comprising: a data circuit couplable to said first electrode for selectively applying a first initialization signal and a first addressing signal to said CLC panel; and a scan circuit couplable to said second electrode for selectively applying a second initialization signal and a second addressing signal to said CLC panel, said first and second initialization signals cooperating to drive a CLC in said CLC panel into a nematic phase and subsequently to drive said CLC to a cholesteric phase focal-conic state, said first and second addressing signals cooperating to selectively drive said CLC from said cholesteric phase focal-conic state to a state having a given reflectivity.

Claim 23

Dependent Claim 129 words

A driving apparatus for a cholesteric liquid crystal (CLC) panel having first and second electrodes coupled to opposing sides thereof, said driving apparatus comprising: a data circuit couplable to said first electrode for selectively applying a first initialization signal and a first addressing signal to said CLC panel; and a scan circuit couplable to said second electrode for selectively applying a second initialization signal and a second addressing signal to said CLC panel, said first and second initialization signals cooperating to drive a CLC in said CLC panel into a nematic phase and subsequently to drive said CLC to a cholesteric phase focal-conic state, said first and second addressing signals cooperating to selectively drive said CLC from said cholesteric phase focal-conic state to a state having a given reflectivity.

Claim 24

Dependent Claim 64 words

The driving apparatus as recited in claim 20 wherein each of said first and second initialization signals comprises a first sequence of pulses having a first amplitude and a second sequence of pulses having a second amplitude, said first sequence of pulses driving said CLC into said nematic phase and said second sequence of pulses driving said CLC to said cholesteric phase focal-conic state.

Claim 25

Dependent Claim 25 words

The driving apparatus as recited in claim 21 wherein said first and second amplitudes are a function of a composition and thickness of said CLC.

Claim 26

Dependent Claim 23 words

The driving apparatus as recited in claim 21 wherein said first and second sequence of pulses have a frequency of about 14.3 kHz.

Claim 27

Dependent Claim 34 words

The driving apparatus as recited in claim 21 wherein said first sequence of pulses has a duration of about 2 ms and said second sequence of pulses has a duration of about 4 ms.

Claim 28

Dependent Claim 52 words

The driving apparatus as recited in claim 20 wherein each of said first and second addressing signals comprises a sequence of addressing pulses having a predetermined amplitude, said driving apparatus operative to drive said CLC to said state having said given reflectivity by varying a duration of said sequence of addressing pulses.

Claim 29

Dependent Claim 23 words

The driving apparatus as recited in claim 25 wherein said predetermined amplitude is a function of a composition and thickness of said CLC.

Claim 30

Dependent Claim 23 words

The driving apparatus as recited in claim 25 wherein said first and second sequence of pulses have a frequency of about 14.3 kHz.

Claim 31

Dependent Claim 78 words

The driving apparatus as recited in claim 25 wherein said sequence of addressing pulses having a predetermined amplitude is preceded by a first sequence of pulses having an amplitude less than a minimum amplitude necessary to drive said CLC from the focal-conic state, a duration of said first sequence of pulses varied such that the sum of the duration of the first sequence of pulses and the duration of the sequence of addressing pulses has a constant value.

Claim 32

Dependent Claim 26 words

The driving apparatus as recited in claim 20 wherein said first and second initialization signals and said first and second addressing signals comprise bipolar electrical waveforms.

Claim 33

Dependent Claim 151 words

A driving apparatus for a cholesteric liquid crystal (CLC) display having a plurality of controllable display elements, said CLC display having a matrix of row and column electrodes that define each of said controllable display elements, said driving apparatus comprising: a data circuit couplable to said column electrodes for selectively applying a first initialization signal and a first addressing signal to each of said display elements; and a scan circuit couplable to said row electrodes for selectively applying a second initialization signal and a second addressing signal to each of said display elements, said first and second initialization signals cooperating to drive said controllable display elements into a nematic phase and subsequently to drive said controllable display elements to a cholesteric phase focal-conic state, said first and second addressing signals cooperating to selectively drive said controllable display elements from said cholesteric phase focal-conic state to a state having a given reflectivity.

Claim 34

Dependent Claim 151 words

A driving apparatus for a cholesteric liquid crystal (CLC) display having a plurality of controllable display elements, said CLC display having a matrix of row and column electrodes that define each of said controllable display elements, said driving apparatus comprising: a data circuit couplable to said column electrodes for selectively applying a first initialization signal and a first addressing signal to each of said display elements; and a scan circuit couplable to said row electrodes for selectively applying a second initialization signal and a second addressing signal to each of said display elements, said first and second initialization signals cooperating to drive said controllable display elements into a nematic phase and subsequently to drive said controllable display elements to a cholesteric phase focal-conic state, said first and second addressing signals cooperating to selectively drive said controllable display elements from said cholesteric phase focal-conic state to a state having a given reflectivity.

Claim 35

Dependent Claim 75 words

The driving apparatus as recited in claim 30 wherein each of said first and second initialization signals comprises a first sequence of pulses having a first amplitude and a second sequence of pulses having a second amplitude, said first sequence of pulses driving selected ones of said controllable display elements into said nematic phase and said second sequence of pulses driving said selected ones of said controllable display elements to said cholesteric phase focal-conic state.

Claim 36

Dependent Claim 25 words

The driving apparatus as recited in claim 31 wherein said first and second amplitudes are a function of a composition and thickness of said CLC.

Claim 37

Dependent Claim 23 words

The driving apparatus as recited in claim 31 wherein said first and second sequence of pulses have a frequency of about 14.3 kHz.

Claim 38

Dependent Claim 34 words

The driving apparatus as recited in claim 31 wherein said first sequence of pulses has a duration of about 2 ms and said second sequence of pulses has a duration of about 4 ms.

Claim 39

Dependent Claim 53 words

The driving apparatus as recited in claim 30 wherein said first and second addressing signals comprise a sequence of addressing pulses having first and second predetermined amplitudes, respectively, said driving apparatus operative to drive said CLC to said state having said given reflectivity by varying a duration of said sequence of addressing pulses.

Claim 40

Dependent Claim 26 words

The driving apparatus as recited in claim 35 wherein said first and second predetermined amplitudes are a function of a composition and thickness of said CLC.

Claim 41

Dependent Claim 23 words

The driving apparatus as recited in claim 35 wherein said first and second sequence of pulses have a frequency of about 14.3 kHz.

Claim 42

Dependent Claim 74 words

The driving apparatus as recited in claim 35 wherein said sequence of addressing pulses is preceded by a first sequence of pulses having an amplitude less than a minimum amplitude necessary to drive said CLC from the focal-conic state, a duration of said first sequence of pulses varied such that the sum of the duration of the first sequence of pulses and the duration of the sequence of addressing pulses has a constant value.

Claim 43

Dependent Claim 27 words

The driving apparatus as recited in claim 30 wherein said first and second initialization signals are applied simultaneously to each of said plurality of controllable display elements.

Claim 44

Dependent Claim 55 words

The driving apparatus as recited in claim 30 wherein said first and second initialization signals are applied to at least a first selected row of said plurality of controllable display elements, said first and second addressing signals being applied simultaneously therewith to at least a second selected row of said plurality of controllable display elements.

Claim 45

Dependent Claim 26 words

The driving apparatus as recited in claim 30 wherein said first and second initialization signals and said first and second addressing signals comprise bipolar electrical waveforms.

Claim 46

Independent Claim 192 words

A method of driving a cholesteric liquid crystal (CLC) display having a plurality of controllable display elements, said CLC display having a matrix of row and column electrodes that define each of said controllable display elements, said method of driving comprising: selectively initializing at least one of said controllable display elements by applying a first initialization signal to at least one of said column electrodes and a second initialization signal to at least one of said row electrodes, said first and second initialization signals cooperating to drive said at least one of said controllable display elements into a nematic phase and subsequently to drive said at least one of said controllable display elements to a cholesteric phase focal-conic state; and selectively addressing said at least one of said controllable display elements by applying a first addressing signal to said at least one of said column electrodes and a second addressing signal to said at least one of said row electrodes, said first and second addressing signals cooperating to selectively drive said at least one of said controllable display elements from said cholesteric phase focal-conic state to a state having a given reflectivity.

Claim 47

Independent Claim 192 words

A method of driving a cholesteric liquid crystal (CLC) display having a plurality of controllable display elements, said CLC display having a matrix of row and column electrodes that define each of said controllable display elements, said method of driving comprising: selectively initializing at least one of said controllable display elements by applying a first initialization signal to at least one of said column electrodes and a second initialization signal to at least one of said row electrodes, said first and second initialization signals cooperating to drive said at least one of said controllable display elements into a nematic phase and subsequently to drive said at least one of said controllable display elements to a cholesteric phase focal-conic state; and selectively addressing said at least one of said controllable display elements by applying a first addressing signal to said at least one of said column electrodes and a second addressing signal to said at least one of said row electrodes, said first and second addressing signals cooperating to selectively drive said at least one of said controllable display elements from said cholesteric phase focal-conic state to a state having a given reflectivity.

Claim 48

Dependent Claim 76 words

The method of driving as recited in claim 42 wherein each of said first and second initialization signals comprises a first sequence of pulses having a first amplitude and a second sequence of pulses having a second amplitude, said first sequence of pulses driving selected ones of said controllable display elements into said nematic phase and said second sequence of pulses driving said selected ones of said controllable display elements to said cholesteric phase focal-conic state.

Claim 49

Dependent Claim 30 words

The method of driving as recited in claim 43 wherein said first and second amplitudes are a function of a composition and thickness of a CLC in said CLC display.

Claim 50

Dependent Claim 24 words

The method of driving as recited in claim 43 wherein said first and second sequence of pulses have a frequency of about 14.3 kHz.

Claim 51

Dependent Claim 35 words

The method of driving as recited in claim 43 wherein said first sequence of pulses has a duration of about 2 ms and said second sequence of pulses has a duration of about 4 ms.

Claim 52

Dependent Claim 62 words

The method of driving as recited in claim 42 wherein said first and second addressing signals comprise a sequence of addressing pulses having first and second predetermined amplitudes, respectively, said step of selectively addressing comprising the step of driving ones of said controllable display elements to said state having said given reflectivity by varying a duration of said sequence of addressing pulses.

Claim 53

Dependent Claim 31 words

The method of driving as recited in claim 47 wherein said first and second predetermined amplitudes are a function of a composition and thickness of a CLC in said CLC display.

Claim 54

Dependent Claim 24 words

The method of driving as recited in claim 47 wherein said first and second sequence of pulses have a frequency of about 14.3 kHz.

Claim 55

Dependent Claim 75 words

The method of driving as recited in claim 47 wherein said sequence of addressing pulses is preceded by a first sequence of pulses having an amplitude less than a minimum amplitude necessary to drive said CLC from the focal-conic state, a duration of said first sequence of pulses varied such that the sum of the duration of the first sequence of pulses and the duration of the sequence of addressing pulses has a constant value.

Claim 56

Dependent Claim 33 words

The method of driving as recited in claim 42 wherein said step of selectively initializing comprises simultaneously applying said first and second initialization signals to each of said plurality of controllable display elements.

Claim 57

Dependent Claim 55 words

The method of driving as recited in claim 42 wherein said step of selectively initializing is performed on at least a first selected row of said plurality of controllable display elements while said step of selectively addressing is performed simultaneously therewith on at least a second selected row of said plurality of controllable display elements.

Claim 58

Dependent Claim 27 words

The method of driving as recited in claim 42 wherein said first and second initialization signals and said first and second addressing signals comprise bipolar electrical waveforms.

Claim 59

Dependent Claim 154 words

A cholesteric liquid crystal (CLC) display system comprising: a CLC panel having a plurality of controllable display elements, said CLC panel having a matrix of row and column electrodes that define each of said controllable display elements; a data circuit coupled to said column electrodes for selectively applying a first initialization signal and a first addressing signal to each of said plurality of controllable display elements; and a scan circuit coupled to said row electrodes for selectively applying a second initialization signal and a second addressing signal to each of said plurality of controllable display elements, said first and second initialization signals cooperating to drive said controllable display elements into a nematic phase and subsequently to drive said controllable display elements to a cholesteric phase focal-conic state, said first and second addressing signals cooperating to selectively drive said controllable display elements from said cholesteric phase focal-conic state to a state having a given reflectivity.

Claim 60

Dependent Claim 154 words

A cholesteric liquid crystal (CLC) display system comprising: a CLC panel having a plurality of controllable display elements, said CLC panel having a matrix of row and column electrodes that define each of said controllable display elements; a data circuit coupled to said column electrodes for selectively applying a first initialization signal and a first addressing signal to each of said plurality of controllable display elements; and a scan circuit coupled to said row electrodes for selectively applying a second initialization signal and a second addressing signal to each of said plurality of controllable display elements, said first and second initialization signals cooperating to drive said controllable display elements into a nematic phase and subsequently to drive said controllable display elements to a cholesteric phase focal-conic state, said first and second addressing signals cooperating to selectively drive said controllable display elements from said cholesteric phase focal-conic state to a state having a given reflectivity.

Claim 61

Dependent Claim 78 words

The CLC display system as recited in claim 54 wherein each of said first and second initialization signals comprises a first sequence of pulses having a first amplitude and a second sequence of pulses having a second amplitude, said first sequence of pulses driving selected ones of said plurality of controllable display elements into said nematic phase and said second sequence of pulses driving said selected ones of said controllable display elements to said cholesteric phase focal-conic state.

Claim 62

Dependent Claim 63 words

The CLC display system as recited in claim 54 wherein said first and second addressing signals comprise a sequence of addressing pulses having first and second predetermined amplitudes, respectively, said CLC display system operative to drive said controllable display elements from said cholesteric phase focal-conic state to said state having said given reflectivity by varying a duration of said sequence of addressing pulses.

Claim 63

Dependent Claim 75 words

The CLC display system as recited in claim 56 wherein said sequence of addressing pulses is preceded by a first sequence of pulses having an amplitude less than a minimum amplitude necessary to drive said CLC from the focal-conic state, a duration of said first sequence of pulses varied such that the sum of the duration of the first sequence of pulses and the duration of the sequence of addressing pulses has a constant value.

Claim 64

Dependent Claim 28 words

The CLC display system as recited in claim 54 wherein said first and second initialization signals are applied simultaneously to each of said plurality of controllable display elements.

Claim 65

Dependent Claim 56 words

The CLC display system as recited in claim 54 wherein said first and second initialization signals are applied to at least a first selected row of said plurality of controllable display elements, said first and second addressing signals being applied simultaneously therewith to at least a second selected row of said plurality of controllable display elements.

Claim 66

Dependent Claim 27 words

The CLC display system as recited in claim 54 wherein said first and second initialization signals and said first and second addressing signals comprise bipolar electrical waveforms.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	2002-08-02	2003-02-01	2003-08-03	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	2006-08-02	2007-02-01	2007-08-03	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2010-08-02	2011-02-01	2011-08-03	$7700.00	Window Closed / Lapsed

Apparatus for and method of driving a cholesteric liquid crystal flat panel display

Abstract

Inventors

Bibliographic Details

Claims Analysis

References Cited (Backward Citations)

USPTO Annuity & Maintenance Windows

Assigned Categories & Tags

Assign Category Tag