Patent ID: 9703182
Date: 2017-07-11
CPC Classifications: G02B,G03B,H03K,H04N

Claim:
1. A projection apparatus comprising: an optical device configured to diffuse coherent light beams; an irradiation unit configured to irradiate coherent light beams to the optical device so that the coherent light beams scan the optical device; a light modulator configured to generate a modulated image using coherent light beams incident on and diffused at respective points of the optical device from the irradiation unit; and a projection optical system configured to project a modulated image generated by the light modulator onto a scattering plane, the modulated image being a two-dimensional image, wherein the light modulator comprises: a plurality of micromirrors provided for each pixel, configured to switch a reflection angle of each coherent light beam from the optical device; and a reflection angle controller including a pulse width modulation generator and a random number generator configured to adjust a reflection angle of each of the plurality of micromirrors for each frame period so that each timing at which the modulated image is begun to be projected onto the scattering plane is random for each frame period, the frame period being a time unit to generate the modulated image, wherein the pulse width modulation generator comprises a plurality of image gradient storages which store image gradient data in accordance with the modulated image, each image gradient storage being provided corresponding to a different pulse width, the random number generator generates the random number for each frame period, the plurality of image gradient storages are reordered at random based on the random number for each frame period, and the reflection angle controller adjusts the reflection angle of each of the plurality of micromirrors based on a pulse width modulation signal generated by the image gradient data stored in the plurality of image gradient storages read out on an alignment order of the plurality of image gradient storages for each frame period and the pulse widths corresponding to each of the plurality of image gradient storages.