Patent ID: 7207679

Claim:
A projection type video display that optically modulates light emitted from a light source by a light valve and projects a video, the projection type video display comprising: means for generating data representing an average picture level of a video on the basis of a video signal; control means for controlling an amount of light emitted from the light source based on the data representing the average picture level; and a lamp driver to drive the light source, wherein the control means includes a look-up table having a plurality of addresses respectively addressing a plurality of control data for controlling the amount of light emitted from the light source, and the data representing the average picture level is used to address the look-up table causing the look-up table to output to the lamp driver corresponding control data for controlling the amount of light output by the light source, and wherein the control data output by the look-up table is n-bit data representing 2 n levels of dimmer data used to control 2 n levels of brightness of the light source, and the control data is output to the lamp driver to drive the light source.