Patent ID: 7532319

Claim:
An apparatus for calibrating displacement of reflective parts in a diffractive optical modulator, comprising: a diffractive optical modulator for, when test voltage is applied thereto, diffracting incident light based on the applied test voltage and emitting linear diffracted light having a plurality of diffraction orders; a light intensity measurement unit disposed near one side of the diffractive optical modulator and configured to measure and output intensity of incident linear diffracted light having a predetermined diffraction order; a projection unit for causing diffracted light having a first predetermined diffraction order, which belongs to the diffracted light having a plurality of diffraction orders, emitted from the diffractive optical modulator, to enter the light intensity measurement unit, and directing diffracted light having a second predetermined diffraction to a screen; and display electronics for applying the test voltage to the diffractive optical modulator, calculating calibration voltage by comparing the intensity of light that is measured by the light intensity measurement unit with intensity of light that is expected to be measured for the diffracted light having a first predetermined diffraction order when the test voltage is applied to the diffractive optical modulator, and determining subsequent driving voltage based on the calibration voltage.