LIQUID CRYSTAL DISPLAY DEVICE
First Claim
1. In an arrangement for locally modifying the optical properties of an indicating medium sandwiched between first and second electrodes, wherein a control voltage is applied acroSs said electrodes, the improvement wherein at least one of said electrodes is in the form of a plurality of separate electrode members, a plurality of rectifier means, means for producing a potential gradient along said first electrode, and means for individually connecting said rectifier means to said electrode members with like polarity for substantially blocking current between the respective electrode member and the other electrode, at least one rectifier means being allocated to each electrode member.
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Accused Products
Abstract
An optical film, for example, of the so called nematic liquid crystal type is sandwiched between two electrodes forming a device of which at least one electrode is segmented. One electrode provides an equipotential plane while the other electrode has a surface resistance which provides a potential gradient therealong. The segmented electrodes are connected to a voltage supply by series or shunt rectifiers. The device may be used, for example, for indicating a measured value such as a voltage by a visible line or bar which represents an interface or a boundary between differing optical states and which bar or line travels through the device along a scale which thus represents direct readings of the measured value.
19 Citations
8 Claims
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1. In an arrangement for locally modifying the optical properties of an indicating medium sandwiched between first and second electrodes, wherein a control voltage is applied acroSs said electrodes, the improvement wherein at least one of said electrodes is in the form of a plurality of separate electrode members, a plurality of rectifier means, means for producing a potential gradient along said first electrode, and means for individually connecting said rectifier means to said electrode members with like polarity for substantially blocking current between the respective electrode member and the other electrode, at least one rectifier means being allocated to each electrode member.
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2. The arrangement according to claim 1, wherein said means providing a potential gradient comprises means applying different potentials to said electrode members.
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3. The arrangement according to claim 1, comprising one electrode which includes n-electrode members, a voltage source, a series connection of resistor means comprising a chain of n-1 resistors with junction points between adjacent resistors, and with first and second end terminals, means for connecting said voltage source to said end terminals in parallel to said resistor chain, said rectifier means comprising a plurality of rectifier elements, means for connecting one end of said rectifier elements in the same polarity sense to said junction points and to said end terminals and the opposite end to a respective one of said electrode members whereby each electrode member is connected to said resistor chain through its respective rectifier element, a further electrode for establishing an equipotential plane, said further electrode being arranged opposite and in register with said one electrode, input terminals, and means for connecting one of said input terminals to said further electrode and another input terminal to said first end terminal of said resistor chain.
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4. The arrangement according to claim 1, wherein said means for providing a potential gradient comprises a resistive layer having a surface resistance of 10 to 100k Ohms on said first electrode, and wherein the second electrode which is located opposite said first electrode is subdivided to comprise n-electrode members.
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5. The arrangement according to claim 4, further comprising first and second contact means arranged at two opposite sides of said potential gradient providing electrode, a d.c. voltage source, means for connecting said contact means to said d.c. voltage source, n-diodes, means for connecting the cathodes of said diodes to said n-electrode members, means for connecting the anodes of all of said diodes together to form a common terminal representing an input terminal, said first contact means representing another input terminal to which one side of said potential gradient providing electrode is connected.
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6. The arrangement according to claim 5, wherein said potential gradient providing electrode has such a shape that between said contact means a staircase potential gradient is obtained.
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7. The arrangement as claimed in claim 1, wherein one of said two electrodes comprises a plurality of n-electrode members, said arrangement further comprising a voltage source, a series connection of n-resistors with first and second end terminals and junctions between adjacent resistors, means for connecting said voltage source to said first and second end terminals, further resistor means for connecting said n-electrode members individually to a respective point along said series connection of n-resistors, a plurality of diodes, means for connecting each of said n-electrodes to a respective one of said diodes in equal polarity sense, means for further connecting said diodes to the other of said two electrodes which acts as an equipotential electrode, and input terminal means connected to said first end terminal of said resistor series connection and to said equipotential electrode.
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8. In an apparatus for locally modifying the optical properties of a liquid crystal layer sandwiched between a pair of electrodes, including a source of control potential, means aPplying said control potential between said electrodes, and means for producing a potential gradient along one of said electrodes;
- the improvement wherein one of said electrodes is separated to form a plurality of separate electrode segments, and further comprising a separate rectifier for each segment and having one electrode connected to the respective segment, each of said rectifiers being connected with the same polarity, and means connectng the other electrodes of said rectifiers to substantially inhibit the application of potentials of one polarity between the respective segment and the other electrode.
Specification