Liquid crystal apparatus with temperature compensation control circuit

Claim 2

A liquid crystal apparatus, comprising: (a) a liquid crystal device comprising scanning electrodes, data electrodes disposed opposite to and intersecting with said scanning electrodes so as to form an electrode matrix, and a ferroelectric liquid crystal disposed between said scanning electrodes and data electrodes; (b) first means for applying a scanning selection signal having a duration of one scanning selection period 1H to said scanning electrodes and applying data signals to said data electrodes in synchronism with the scanning selection signal so as to apply a drive voltage having an amplitude V OP to said liquid crystal; and (c) control means for controlling said first means so as to change the one scanning selection period 1H by a change Δ1H and the drive voltage amplitude V OP by a change ΔV OP corresponding to a change in ambient temperature, the changes Δ1H and ΔV OP satisfying the following formula (1): -0.8≧Δlog 1H/Δlog V.sub.OP ≧-1.4 (1), wherein Δlog 1H =log (1H 1 +Δ1H)-log 1H 1 , and Δlog V OP =log(V OP1 +ΔV OP )-log V OP1 , 1H 1 being one scanning selection period before the change, V OP1 being the drive voltage amplitude before the change.

Claim 3

An apparatus according to claim 1, wherein said control means includes means for re-setting the changed drive voltage amplitude caused by the change in temperature to the drive voltage amplitude before the change thereof due to the change in temperature after a prescribed number of vertical scanning operations.

Claim 4

An apparatus according to claim 1, wherein the magnitude of the change Δ1H caused by a temperature change is preliminarily set for each prescribed temperature-changing point.

Claim 5

An apparatus according to claim 1, wherein the magnitude of the change ΔV OP caused by a temperature change is preliminarily set for each prescribed temperature-changing point.

Claim 6

A liquid crystal apparatus, comprising: (a) a liquid crystal device comprising X scanning electrodes, Y data electrodes disposed intersecting said scanning electrodes to form an X-Y electrode matrix, and a ferroelectric liquid crystal disposed between said scanning electrodes and data electrodes, X and Y being positive integers; (b) scanning electrode drive means for applying a scanning selection signal having a duration of one scanning selection period 1H to said scanning electrodes N electrodes apart(N: a positive integer) in one vertical scanning and applying the scanning selection signal to said X scanning electrodes in N+1 times of vertical scanning; (c) data electrode drive means for applying data signals to said data electrodes in parallel and in synchronism with the scanning selection signal so as to apply a drive voltage having an amplitude V OP to said liquid crystal; and (d) control means for controlling said scanning electrode drive means and data electrode drive means so as to change the one scanning selection period 1H by a change Δ1H and the drive voltage amplitude V OP by a change ΔV OP corresponding to a change in ambient temperature, the changes Δ1H and ΔV OP satisfying the following formula (1):

Claim 7

A liquid crystal apparatus, comprising: (a) a liquid crystal device comprising X scanning electrodes, Y data electrodes disposed intersecting said scanning electrodes to form an X-Y electrode matrix, and a ferroelectric liquid crystal disposed between said scanning electrodes and data electrodes, X and Y being positive integers; (b) scanning electrode drive means for applying a scanning selection signal having a duration of one scanning selection period 1H to said scanning electrodes N electrodes apart(N: a positive integer) in one vertical scanning and applying the scanning selection signal to said X scanning electrodes in N+1 times of vertical scanning; (c) data electrode drive means for applying data signals to said data electrodes in parallel and in synchronism with the scanning selection signal so as to apply a drive voltage having an amplitude V OP to said liquid crystal; and (d) control means for controlling said scanning electrode drive means and data electrode drive means so as to change the one scanning selection period 1H by a change Δ1H and the drive voltage amplitude V OP by a change ΔV OP corresponding to a change in ambient temperature, the changes Δ1H and ΔV OP satisfying the following formula (1):

Claim 8

-0. 8≧Δlog 1H/Δlog V OP ≧-1.4 (1), wherein Δlog 1H=log (1H 1 +Δ1H)-log 1H 1 , and Δlog V OP =log(V OP1 +ΔV OP )-log V OP1 , 1H 1 being one scanning selection period before the change, V OP1 being the drive voltage amplitude before the change.

Claim 9

-0. 8≧Δlog 1H/Δlog V OP ≧-1.4 (1), wherein Δlog 1H=log (1H 1 +Δ1H)-log 1H 1 , and Δlog V OP =log(V OP1 +ΔV OP )-log V OP1 , 1H 1 being one scanning selection period before the change, V OP1 being the drive voltage amplitude before the change.

Claim 10

An apparatus according to claim 5, wherein said control means includes means for re-setting the changed drive voltage amplitude caused by the change in temperature to the drive voltage amplitude before the change thereof due to the change in temperature after a prescribed number of vertical scanning operations.

Claim 11

An apparatus according to claim 5, wherein the magnitude of the change Δ1H caused by a temperature change is preliminarily set for each prescribed temperature-changing point.

Claim 12

An apparatus according to claim 5, wherein the magnitude of the change ΔV OP caused by a temperature change is preliminarily set for each prescribed temperature-changing point.

Claim 13

A liquid crystal apparatus, comprising: (a) a liquid crystal device comprising scanning electrodes, data electrodes disposed intersecting said scanning electrodes to form an electrode matrix, and a ferroelectric liquid crystal disposed between said scanning electrodes and data electrodes; (b) scanning electrode drive means for applying to a selected scanning electrode a scanning selection signal having a duration of one scanning selection period 1H and comprising a first voltage of one polarity and a second voltage of the other polarity with reference to the voltage level of a non-selected scanning electrode; (c) data electrode drive means for applying, to a selected data electrode, a first voltage signal providing a first drive voltage causing one orientation state of the ferroelectric liquid crystal in combination with said voltage of one polarity and a second voltage signal providing a second drive voltage causing the other orientation state of the ferroelectric liquid crystal in combination with said voltage of the other polarity, and to a non-selected data electrode, a third voltage signal providing a third voltage causing the one orientation state of the ferroelectric liquid crystal in combination with said voltage of one polarity and a fourth voltage signal providing a fourth voltage not changing the orientation state of the ferroelectric liquid crystal; and (d) control means for controlling said scanning electrode drive means and data electrode drive means so as to change the one scanning selection period 1H by a change Δ1H and the first, second and third drive voltages by an amplitude change ΔV OP corresponding to a change in ambient temperature satisfying the following formula (1):

Claim 14

A liquid crystal apparatus, comprising: (a) a liquid crystal device comprising scanning electrodes, data electrodes disposed intersecting said scanning electrodes to form an electrode matrix, and a ferroelectric liquid crystal disposed between said scanning electrodes and data electrodes; (b) scanning electrode drive means for applying to a selected scanning electrode a scanning selection signal having a duration of one scanning selection period 1H and comprising a first voltage of one polarity and a second voltage of the other polarity with reference to the voltage level of a non-selected scanning electrode; (c) data electrode drive means for applying, to a selected data electrode, a first voltage signal providing a first drive voltage causing one orientation state of the ferroelectric liquid crystal in combination with said voltage of one polarity and a second voltage signal providing a second drive voltage causing the other orientation state of the ferroelectric liquid crystal in combination with said voltage of the other polarity, and to a non-selected data electrode, a third voltage signal providing a third voltage causing the one orientation state of the ferroelectric liquid crystal in combination with said voltage of one polarity and a fourth voltage signal providing a fourth voltage not changing the orientation state of the ferroelectric liquid crystal; and (d) control means for controlling said scanning electrode drive means and data electrode drive means so as to change the one scanning selection period 1H by a change Δ1H and the first, second and third drive voltages by an amplitude change ΔV OP corresponding to a change in ambient temperature satisfying the following formula (1):

Claim 15

-0. 8≧Δlog 1H/Δlog V OP ≧-1.4 (1), wherein Δlog 1H=log (1H 1 +Δ1H)-log 1H 1 , and Δlog V OP =log(V OP1 +ΔV OP )-log V OP1 , 1H 1 being one scanning selection period before the change, V OP1 being the drive voltage amplitude before the change.

Claim 16

-0. 8≧Δlog 1H/Δlog V OP ≧-1.4 (1), wherein Δlog 1H=log (1H 1 +Δ1H)-log 1H 1 , and Δlog V OP =log(V OP1 +ΔV OP )-log V OP1 , 1H 1 being one scanning selection period before the change, V OP1 being the drive voltage amplitude before the change.

Claim 17

An apparatus according to claim 9, wherein said control means includes means for re-setting the changed drive voltage amplitude caused by the change in temperature to the drive voltage amplitude before the change thereof due to the change in temperature after a prescribed number of vertical scanning operations.

Claim 18

An apparatus according to claim 9, wherein the magnitude of the change Δ1H caused by a temperature change is preliminarily set for each prescribed temperature-changing point.

Claim 19

An apparatus according to claim 9, wherein the magnitude of the change ΔV OP caused by a temperature change is preliminarily set for each prescribed temperature-changing point.