Display device for electronic desk calculator

Claim 2

In an electronic desk calculator, the improvement which comprises a pair of spaced plates, at least one of which is transparent; a common conductive electrode mounted on the inside surface of one of said plates; a segmented electrode mounted on the inner surface of the other of said plates in facing relation to said common electrode, said segmented electrode including a plurality of segments, various combinations of which defines the numbers zero-nine in at least two columns, the one of said common and segmented electrodes mounted on said transparent plate being transparent; nematic liquid crystal material retained between said plates and selected to cause an activated state when a predetermined voltage is applied between said common and segmented electrodes; driving circuit means connected to at least one of said segmented electrodes and said common electrode, each said driving circuit means including gate means for controlling the application of an alternating voltage between said electrodes when the region of said liquid crystal adjacent said segmented electrode is to be rendered visible, said gate means having a pair of inputs for receiving a display actuation signal when the region of the segmented electrode to which said gate means is connected is to be rendered visible, and an intermittent pulse signal.

Claim 3

An electronic desk calculator as recited in claim 1, including driving circuit means connected to at least one of said segmented electrodes and said common electrode, each said driving circuit means including gate means for controlling the applicaton of an alternating voltage between said electrodes when the region of said liquid crystal adjacent said segmented electrode is to be rendered visible.

Claim 4

An electronic desk calculator as recited in claim 2, wherein said gate means has a pair of inputs for receiving a display actuation signal when the region of the segmented electrode to which said gate means is connected is to be rendered visible and an intermittent pulse signal.

Claim 5

In an electronic desk calculator, the improvement which comprises a pair of spaced plates, at least one of which is transparent; a common conductive electrode mounted on the inside surface of one of said plates; a segmented electrode mounted on the inner surface of the other of said plates in facing relation to said common electrode, said segmented electrode including a plurality of segments, various combinations of which defines the numbers zero-nine in at least two columns, the one of said common and segmented electrodes mounted on said transparent plate being transparent; nematic liquid crystal material retained between said plates and selected to cause an activated state when a predetermined voltage is applied between said common and segmented electrodes; driving circuit means connected to at least one of said segmented electrodes and said common electrode, each said driving circuit means including gate means for controlling the application of an alternating voltage between said electrodes when the region of said liquid crystal adjacent said segmented electrode is to be rendered visible, said gate means having a pair of inputs for receiving a display actuation signal When the region of the segmented electrode to which said gate means is connected is to be rendered visible, and an intermittent pulse signal; and a DC voltage source, said gate means further including an AND gate incorporating said pair of inputs, and having an output; and switch means adapted for selective placement in either a conductive or non-conductive state in response to the signal from said AND gate output, said switch means being placed in a conductive state by the intermittent pulse signal passed by said AND gate when said display actuation signal is applied to one input of said AND gate and being placed in a non-conductive state in response to the absence of an output signal from said AND gate in the absence of a display actuation signal applied to said AND gate, said segmented and common electrodes being connected in parallel to said switch means, so that an alternating voltage is applied to said electrodes in response to said display actuation signal.

Claim 6

In an electronic desk calculator, the improvement which comprises a pair of spaced plates, at least one of which is transparent; a common conductive electrode mounted on the inside surface of one of said plates; a segmented electrode mounted on the inner surface of the other of said plates in facing relation to said common electrode, said segmented electrode including a plurality of segments, various combinations of which defines the numbers zero-nine in at least two columns, the one of said common and segmented electrodes mounted on said transparent plate being transparent; nematic liquid crystal material retained between said plates and selected to cause an activated state when a predetermined voltage is applied between said common and segmented electrodes; driving circuit means connected to at least one of said segmented electrodes and said common electrode, each said driving circuit means including gate means for controlling the application of an alternating voltage between said electrodes when the region of said liquid crystal adjacent said segmented electrode is to be rendered visible, said gate means having a pair of inputs for receiving a display actuation signal When the region of the segmented electrode to which said gate means is connected is to be rendered visible, and an intermittent pulse signal; and a DC voltage source, said gate means further including an AND gate incorporating said pair of inputs, and having an output; and switch means adapted for selective placement in either a conductive or non-conductive state in response to the signal from said AND gate output, said switch means being placed in a conductive state by the intermittent pulse signal passed by said AND gate when said display actuation signal is applied to one input of said AND gate and being placed in a non-conductive state in response to the absence of an output signal from said AND gate in the absence of a display actuation signal applied to said AND gate, said segmented and common electrodes being connected in parallel to said switch means, so that an alternating voltage is applied to said electrodes in response to said display actuation signal.

Claim 7

An electronic desk calculator as recited in claim 4, wherein said switch means includes a transistor having a base, emitter and collector, said AND gate output being connected to the base of said transistor, the emitter-collector path of said transistor being connected in parallel with said segmented and common electrodes and in series with said DC voltage source.

Claim 8

An electronic calculator as recited in claim 5, including capacitor means in series with said common and segmented electrodes, said series connection being in parallel with said transistor emitter-collector path.

Claim 9

An electronic calculator as recited in claim 5, including resistor means connected in parallel with said segmented and common electrodes, said resistor means being of a value selected to lower the high internal impedance of the liquid crystal.

Claim 10

In an electronic desk calculator, the improvement which comprises a pair of spaced plates, at least one which is transparent; a common conductive electrode mounted on the inside surface of one of said plates; a segmented electrode mounted on the inner surface of the other of said plates in facing relation to said common electrode, said segmented electrode including a plurality of segments, various combinations of which defines the numbers zero-nine in at least two columns, the one of said common and segmented electrodes mounted on said transparent plate being transparent; nematic liquid crystal material retained between said plates and selected to cause an activated state when a predetermined voltage is applied between said common and segmented electrodes; and driving circuit means connected to at least one of said segmented electrodes and said common electrode, each said driving circuit means including gate means for controlling the application of an alternating voltage between said electrodes when the region of said liquid crystal adjacent said segmented electrode is to be rendered visible, said gate means having a pair of inputs for receiving a display actuation signal when the region of the segmented electrode to which said gate means is connected is to be rendered visible, and an intermittent pulse signal, said gate means further including an exclusive OR gate including said pair of inputs and having an output connected to one of said common and segmented electrodes, the other of said common or segmented electrodes being connected to receive said intermittent pulse signal, so that an alternating voltage is supplied to said electrodes in response to said display actuation signal.

Claim 11

In an electronic desk calculator, the improvement which comprises a pair of spaced plates, at least one which is transparent; a common conductive electrode mounted on the inside surface of one of said plates; a segmented electrode mounted on the inner surface of the other of said plates in facing relation to said common electrode, said segmented electrode including a plurality of segments, various combinations of which defines the numbers zero-nine in at least two columns, the one of said common and segmented electrodes mounted on said transparent plate being transparent; nematic liquid crystal material retained between said plates and selected to cause an activated state when a predetermined voltage is applied between said common and segmented electrodes; and driving circuit means connected to at least one of said segmented electrodes and said common electrode, each said driving circuit means including gate means for controlling the application of an alternating voltage between said electrodes when the region of said liquid crystal adjacent said segmented electrode is to be rendered visible, said gate means having a pair of inputs for receiving a display actuation signal when the region of the segmented electrode to which said gate means is connected is to be rendered visible, and an intermittent pulse signal, said gate means further including an exclusive OR gate including said pair of inputs and having an output connected to one of said common and segmented electrodes, the other of said common or segmented electrodes being connected to receive said intermittent pulse signal, so that an alternating voltage is supplied to said electrodes in response to said display actuation signal.