Patent ID: 9250459
Filing Date: 2016-02-02
CPC Classification: G02F,G09G

Claim Text:
1. A spatial light modulation device which modulates a phase of incident light for each of a plurality of pixels one-dimensionally or two-dimensionally arrayed, the device comprising: a liquid crystal layer modulating a phase of the incident light according to a level of an applied electric field; a temperature sensor generating a temperature signal which is a signal corresponding to a temperature of the liquid crystal layer; a plurality of pixel electrodes which are provided for each of the plurality of pixels and apply a voltage for generating the applied electric field to the liquid crystal layer; and a voltage generation unit providing the voltage to the plurality of pixel electrodes, wherein the voltage generation unit has storage means storing in advance one or a plurality of coefficients included in a function expressing a correlation between a temperature change amount with respect to a reference temperature of the liquid crystal layer and a variation in phase modulation amount in the liquid crystal layer, and a look up table for correcting nonlinearity between a level of the voltage and the phase modulation amount at the reference temperature, and carries out a calculation for correcting the level of the voltage to be applied to each pixel electrode by correcting a control input value S for controlling the level of the voltage by use of a temperature indicated by the temperature signal provided from the temperature sensor and the one or plurality of coefficients, and determining the level of the voltage based on the corrected control input value S by use of the look up table.