Patent ID: 9135847
Filing Date: 2015-09-15
Classification: G02B,G03H,G09G

Abstract:
1. An image display apparatus, comprising: a light source which emits coherent light; a spatial modulation element which diffracts the coherent light by displaying a diffraction grating pattern corresponding to an input image and which displays a virtual image by the diffracted light; and a control unit which calculates a total brightness representing a sum total of brightnesses of all pixels of the input image, and controls at least one of the light source and the spatial modulation element in such a manner that, if the total brightness has decreased, the virtual image is displayed at a lower brightness than a reference virtual image displayed when the input image is used directly, wherein, when the total brightness has decreased, the control unit adds a control pattern, which includes an image different from the input image, to the input image in such a manner that the virtual image is displayed at a lower brightness than the reference virtual image, and controls the spatial modulation element so as to display a diffraction grating pattern corresponding to the input image to which the control pattern has been added.