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US4930875A Expired / Lapsed US ⏱️ 0.0 years remaining

Scanning driver circuit for ferroelectric liquid crystal device

Assignee: Canon Inc
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Filing: 1989-06-27
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Granted: 1990-06-05
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Expires: 2009-06-27
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Abstract

Abstract A driving apparatus includes a scanning driver circuit connected to scanning electrodes and a signal driver circuit connected to signal electrodes. The scanning driver circuit includes: (1) a drive signal voltage generating unit which includes a first signal voltage generating unit for generating a scanning selection signal voltage supplied to a first bus, and a second signal voltage generating unit for generating a scanning nonselection signal voltage supplied to a second bus, (2) a switching circuit unit for selectively supplying the scanning selection signal or the scanning nonselection signal to a scanning electrode, and (3) a switching signal generating unit for supplying a switching control signal to the switching circuit unit.

Inventors

  • 👤 Hiroshi Inoue
  • 👤 Yoshiyuki Osada
  • 👤 Yutaka Inaba

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-28 18:36
CPC Classifications
G; G09; G09G; G09G3/00; G09G3/20; G09G3/34; G09G3/36; G09G3/3611; G09G3/3696; G09G3/3622; G09G3/3629; G09G3/3685; G09G3/3692; G09G2310/00; G09G2310/06; G09G2310/061; G09G2320/00; G09G2320/02; G09G2320/0209

Claims Analysis

Total Claims: 26
Claim 1
Independent Claim 187 words
A driving apparatus, comprising a scanning driver circuit connected to scanning electrodes and a signal driver circuit connected to signal electrodes, said scanning driver circuit comprising: (1) a driver signal voltage generating unit which includes: a first signal voltage generating unit comprising: a first circuit for generating a scanning selection signal including a sequence of three voltages comprising a voltage of one polarity, a voltage of the other polarity, and zero voltage, and means for controlling said first circuit so as to generate the sequence of three voltages in different phases and for continuously supplying the scanning selection signal comprising the sequence of three voltages to a first bus, the polarities and the zero level of the voltages being defined with respect to a scanning nonselection signal voltage, and a second signal voltage generating unit for generating a scanning nonselection signal voltage continuously supplied to a second bus; (2) a switching circuit unit for selectively supplying the scanning selection signal or the scanning nonselection signal to a scanning electrode; and (3) a switching signal generating unit for supplying a switching control signal to the switching circuit unit.
Claim 2
Dependent Claim 187 words
A driving apparatus, comprising a scanning driver circuit connected to scanning electrodes and a signal driver circuit connected to signal electrodes, said scanning driver circuit comprising: (1) a driver signal voltage generating unit which includes: a first signal voltage generating unit comprising: a first circuit for generating a scanning selection signal including a sequence of three voltages comprising a voltage of one polarity, a voltage of the other polarity, and zero voltage, and means for controlling said first circuit so as to generate the sequence of three voltages in different phases and for continuously supplying the scanning selection signal comprising the sequence of three voltages to a first bus, the polarities and the zero level of the voltages being defined with respect to a scanning nonselection signal voltage, and a second signal voltage generating unit for generating a scanning nonselection signal voltage continuously supplied to a second bus; (2) a switching circuit unit for selectively supplying the scanning selection signal or the scanning nonselection signal to a scanning electrode; and (3) a switching signal generating unit for supplying a switching control signal to the switching circuit unit.
Claim 3
Dependent Claim 28 words
An apparatus according to claim 1, wherein said switching signal generating unit generates a switching control signal for sequentially supplying the scanning selection signal to the scanning electrodes.
Claim 4
Dependent Claim 14 words
An apparatus according to claim 1, wherein said switching circuit unit comprises a transistor.
Claim 5
Dependent Claim 19 words
An apparatus according to claim 3, wherein the transmitter in the switching circuit unit comprises a field effect transistor.
Claim 6
Dependent Claim 16 words
An apparatus according to claim 4, wherein said field effect transistor comprises a thin film transistor.
Claim 7
Dependent Claim 22 words
An apparatus according to claim 5, wherein said thin film transistor comprises a semiconductor film of amorphous silicon, polysilicon, CdSe or ZnSe.
Claim 8
Dependent Claim 19 words
An apparatus according to claim 1, wherein said switching signal generating circuit includes a shift register and an inverter.
Claim 9
Dependent Claim 15 words
An apparatus according to claim 7, wherein said shift register is a dynamic shift register.
Claim 10
Dependent Claim 242 words
A driving apparatus for a display panel of a type comprising matrix electrodes formed by scanning electrodes and signal electrodes arranged to intersect with the scanning electrodes, wherein a contrast at each intersection of the scanning electrodes and the signal electrodes is discriminated depending on the direction of an electric field applied to the intersection, said scanning electrodes being connected to a scanning driver circuit and said signal electrodes being connected to a signal driver circuit, said scanning driver circuit comprising: (1) a driver signal voltage generating unit which includes: a first signal voltage generating unit comprising: a first circuit for generating a scanning selection signal including a sequence of three voltages comprising a voltage of one polarity, a voltage of the other polarity, and zero voltage, and means for controlling said first circuit so as to generate the sequence of three voltages in different phases and for continuously supplying the scanning selection signal comprising the sequence of three voltages to a first bus, the polarities and the zero level of the voltages being defined with respect to a scanning nonselection signal voltage, and a second signal voltage generating unit for generating a scanning nonselection signal voltage continuously supplied to a second bus; (2) a switching circuit unit for selectively supplying the scanning selection signal or the scanning nonselection signal to a scanning electrode; and (3) a switching signal generating unit for supplying a switching control signal to the switching circuit unit.
Claim 11
Dependent Claim 242 words
A driving apparatus for a display panel of a type comprising matrix electrodes formed by scanning electrodes and signal electrodes arranged to intersect with the scanning electrodes, wherein a contrast at each intersection of the scanning electrodes and the signal electrodes is discriminated depending on the direction of an electric field applied to the intersection, said scanning electrodes being connected to a scanning driver circuit and said signal electrodes being connected to a signal driver circuit, said scanning driver circuit comprising: (1) a driver signal voltage generating unit which includes: a first signal voltage generating unit comprising: a first circuit for generating a scanning selection signal including a sequence of three voltages comprising a voltage of one polarity, a voltage of the other polarity, and zero voltage, and means for controlling said first circuit so as to generate the sequence of three voltages in different phases and for continuously supplying the scanning selection signal comprising the sequence of three voltages to a first bus, the polarities and the zero level of the voltages being defined with respect to a scanning nonselection signal voltage, and a second signal voltage generating unit for generating a scanning nonselection signal voltage continuously supplied to a second bus; (2) a switching circuit unit for selectively supplying the scanning selection signal or the scanning nonselection signal to a scanning electrode; and (3) a switching signal generating unit for supplying a switching control signal to the switching circuit unit.
Claim 12
Dependent Claim 28 words
An apparatus according to claim 9, wherein said switching signal generating unit generates a switching control signal for sequentially supplying the scanning selection signal to the scanning electrodes.
Claim 13
Dependent Claim 40 words
An apparatus according to claim 9, wherein said scanning nonselection signal voltage comprises a constant voltage, and wherein said scanning selection signal voltage comprises a positive-polarity voltage and a negative-polarity voltage respectively with reference to the scanning nonselection signal voltage.
Claim 14
Dependent Claim 47 words
An apparatus according to claim 9, wherein said scanning nonselection signal voltage is a constant voltage, and wherein said scanning selection signal voltage comprises a positive-polarity voltage, a negative polarity voltage and a voltage of the same level, respectively, with reference to the scanning nonselection signal voltage.
Claim 15
Dependent Claim 30 words
An apparatus according to claim 9, further comprising synchronizing means for synchronizing the scanning selection signal with a data signal supplied from said signal driver circuit to a signal electrode.
Claim 16
Dependent Claim 14 words
An apparatus according to claim 9, wherein said switching circuit unit comprises a transistor.
Claim 17
Dependent Claim 19 words
An apparatus according to claim 14, wherein the transistor in the switching circuit unit comprises a field effect transistor.
Claim 18
Dependent Claim 16 words
An apparatus according to claim 15, wherein said field effect transistor comprises a thin film transistor.
Claim 19
Dependent Claim 22 words
An apparatus according to claim 16, wherein said thin film transistor comprises a semiconductor film of amorphous silicon, polysilicon, CdSe or ZnSe.
Claim 20
Dependent Claim 19 words
An apparatus according to claim 9, wherein said switching signal generating circuit includes a shift register and an inverter.
Claim 21
Dependent Claim 15 words
An apparatus according to claim 18, wherein said shift register comprises a dynamic shift register.
Claim 22
Dependent Claim 24 words
An apparatus according to claim 9, wherein a ferroelectric liquid crystal is disposed at the intersections of the scanning electrodes and the signal electrodes.
Claim 23
Dependent Claim 17 words
An apparatus according to claim 20, wherein said ferroelectric liquid crystal comprises a chiral smectic liquid crystal.
Claim 24
Dependent Claim 38 words
An apparatus according to claim 21, wherein said chiral smectic liquid crystal is disposed in a layer thin enough to release the helical structure inherent to the chiral smectic liquid crystal in the absence of an electric field.
Claim 25
Dependent Claim 19 words
An apparatus according to claim 9, wherein said switching circuit is disposed on a substrate constituting said display panel.
Claim 26
Dependent Claim 28 words
An apparatus according to claim 9, wherein said switching circuit, switching signal generating unit, first bus, and second bus are disposed on a substrate constituting said display panel.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1993-06-04 1993-12-04 1994-06-05 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1997-06-04 1997-12-04 1998-06-05 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2001-06-04 2001-12-04 2002-06-05 $7700.00 Window Closed / Lapsed

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