Information holding device

Claim 2

An information holding device comprising: a pair of substrates (230, 240) having a first electrode (210) and a second electrode (220) oppositely formed on opposing surfaces thereof; a dielectric material (250) disposed between said pair of substrates; means (350, 360, 370) for changing a capacitance of that portion of said dielectric material disposed between said first electrode and said second electrode; and capacitance detecting means (310, 320) for detecting the capacitance of said dielectric material portion disposed between said first electrode and said second electrode.

Claim 3

An information holding device according to Claim 1, wherein said capacitance detecting means includes a circuit (310) for applying a predetermined voltage to said first electrode and a circuit (320) for detecting a current flowing through said second electrode.

Claim 4

An information holding device comprising: a pair of electrodes (33, 34) having a plurality of first electrodes (33) and a plurality of second electrodes (34) oppositely formed on opposing surface thereof; a dielectric material (35) disposed between said pair of substrates; means (21, 22, 23, 24) for changing a capacitance of those portions of said dielectric material disposed between said plurality of first electrodes and said plurality of second electrodes; a circuit (83) for selectively applying a predetermined voltage to at least one of said plurality of first electrodes and maintaining the rest of said plurality of first electrodes to the same potential as that of said plurality of second electrodes; and a circuit (91, 92, 93) for detecting a current flowing through said second electrodes.

Claim 5

An information holding device comprising: a pair of electrodes (33, 34) having a plurality of first electrodes (33) and a plurality of second electrodes (34) oppositely formed on opposing surface thereof; a dielectric material (35) disposed between said pair of substrates; means (21, 22, 23, 24) for changing a capacitance of those portions of said dielectric material disposed between said plurality of first electrodes and said plurality of second electrodes; a circuit (83) for selectively applying a predetermined voltage to at least one of said plurality of first electrodes and maintaining the rest of said plurality of first electrodes to the same potential as that of said plurality of second electrodes; and a circuit (91, 92, 93) for detecting a current flowing through said second electrodes.

Claim 6

An information holding device according to Claim 1, wherein said dielectric material has a capacitance thereof changed by the application of an electric field or a heat and stored for a predetermined time after the removal of the electric field or the heat.

Claim 7

An information holding device according to Claim 3, wherein said dielectric material has a capacitance thereof changed by the application of an electric field or a heat and stored for a predetermined time after the removal of the electric field or the heat.

Claim 8

An information holding device according to Claim 4 wherein said dielectric material is a liquid crystal having a smectic A phase.

Claim 9

An information holding device according to Claim 5 wherein said dielectric material is a liquid crystal having a smectic A phase.

Claim 10

An information holding device according to Claim 1, wherein said means for changing the capacitance of the dielectric material portions is means for heating said dielectric material.

Claim 11

An information holding device according to Claim 3, wherein said means for changing the capacitance of the dielectric material portions is means for heating said dielectric material.

Claim 12

An information holding device according to Claim 8, wherein said means for heating said dielectric material is optical means.

Claim 13

An information holding device according to Claim 9, wherein said means for heating said dielectric material is optical means.

Claim 14

An information holding device according to Claim 3 wherein said predetermined voltage is selected to a voltage which does not cause a substantial change in the static capacitance of said dielectric material.

Claim 15

An information holding device according to Claim 2, wherein said predetermined voltage is selected to a voltage which does not cause a significant change in the capacitance of said dielectric material.