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US3891306A Expired / Lapsed US ⏱️ 0.0 years remaining

Method for driving liquid cell display panel

Assignee: Hitachi Ltd
•
Filing: 1973-07-20
•
Granted: 1975-06-24
•
Expires: 1993-07-20
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Abstract

Abstract A method for driving a liquid cell in a scanning liquid cell display panel in which the liquid cell is interposed between two scanning electrode groups comprises the step of applying a DC voltage and an AC voltage having a frequency above the limiting frequency of the liquid crystal to said two scanning electrode groups during a period of semi-selection of the scanning while applying said DC voltage thereto during a period of full selection, an amplitude ratio of said AC to DC voltages during said period of semi-selection ranging from 1 to 2.

Inventors

  • 👤 Isamu Mitomo
  • 👤 Tetsunori Kaji
  • 👤 Masakazu Fukushima

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-25 02:02
CPC Classifications
G; G09; G09G; G09G3/00; G09G3/20; G09G3/34; G09G3/36; G09G3/3611; G09G3/3622

Claims Analysis

Total Claims: 7
Claim 1
Independent Claim 168 words
A method for driving a liquid cell display panel including a plurality of first electrodes arranged in parallel to each other, a plurality of second electrodes respectively intersecting with each of said first electrodes and arranged in parallel to each other, and liquid cells of nematic type disposed at the respective intersections of said first electrodes with said second electrodes, said method comprising the step of applying a voltage to a predetermined liquid cell of said liquid cells through said first and second electrodes to drive said predetermined liquid cell, wherein said voltage includes a DC voltage and a high frequency voltage superimposed thereon during periods of two types of semi-selection of said liquid cell and said voltage includes at least a DC voltage during a period of full selection thereof, an amplitude ratio of said high frequency voltage to DC voltage during the period of at least one of said two types of semi-selection being in the range of at least 1 and not more than 2.
Claim 2
Independent Claim 168 words
A method for driving a liquid cell display panel including a plurality of first electrodes arranged in parallel to each other, a plurality of second electrodes respectively intersecting with each of said first electrodes and arranged in parallel to each other, and liquid cells of nematic type disposed at the respective intersections of said first electrodes with said second electrodes, said method comprising the step of applying a voltage to a predetermined liquid cell of said liquid cells through said first and second electrodes to drive said predetermined liquid cell, wherein said voltage includes a DC voltage and a high frequency voltage superimposed thereon during periods of two types of semi-selection of said liquid cell and said voltage includes at least a DC voltage during a period of full selection thereof, an amplitude ratio of said high frequency voltage to DC voltage during the period of at least one of said two types of semi-selection being in the range of at least 1 and not more than 2.
Claim 3
Dependent Claim 20 words
A driving method as set forth in claim 1, wherein a low frequency voltage is substituted for said DC voltage.
Claim 4
Dependent Claim 44 words
A driving method as set forth in claim 1 including applying a DC voltage having a high frequency voltage superimposed thereon to a first electrode or a second electrode associated with a respective liquid cell during the period of semi-selection of said liquid cell.
Claim 5
Dependent Claim 33 words
A driving method as set forth in claim 1, wherein the DC voltage and the high frequency voltage are applied during the entire period of semi-selection so as to provide said amplitude ratio.
Claim 6
Dependent Claim 24 words
A driving method as set forth in claim 1, wherein the amplitude ratio of the high frequency voltage to the DC voltage is 2.
Claim 7
Dependent Claim 32 words
A method as set forth in claim 1, wherein the amplitude ratio of high frequency voltage to DC voltage is in the range of more than 1 and not more than 2.

References Cited (Backward Citations)

US3575492A Cited
US3786486A Cited
US3740717A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1978-06-23 1978-12-23 1979-06-24 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1982-06-23 1982-12-23 1983-06-24 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1986-06-23 1986-12-23 1987-06-24 $7700.00 Window Closed / Lapsed

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