Patent ID: 8866709

Claim:
A projection display apparatus that displays an image according to image data, comprising: a light source; a spatial light modulator configured to modulate, according to given control data, light emitted from the light source into image projection light to project an image; a data adjuster configured to generate the control data according to the image data; a light amount adjuster configured to adjust an upper limit of brightness of the image projection light; a light sensor configured to detect brightness of the image projection light adjusted by the light amount adjuster; an image analyzer configured to analyze the image data and to determine, according to analysis result of the image data, a target value for the brightness detected by the light sensor, the image analyzer repeatedly determining the target value each time the image data changes; a brightness restricting unit configured to control the light amount adjuster to cause the brightness detected by the light sensor to approach the target value; and a projection lens system configured to project the image projection light, wherein the projection lens system includes a first optical element and a second optical element disposed at a projected image side of the first optical element, the projection lens system has a convergence point at which the image projection light converges between the first and the second optical elements, and the light sensor receives light from at least one of the first and the second optical elements.