Patent ID: 6409350
Filing Date: 2002-06-25
Classification: H04N

Abstract:
An LCD projector comprising:a power source (11, 20); an image data input for producing an image data; a light source (30) which is capable of emitting light with R, G, B components and to provide different levels of power; wherein the change in output power of the power source (20) is used to change the output power of the light source (30); a LCD panel (50) for modifying light rays from the light source (30) in accordance with said image data to produce light rays of an image; a projecting lens (60) for projecting the light rays from the LCD panel (50) onto a screen (70) through enlargement; a control circuit (81) for controlling an output of the power source so as to selectively set an output power: a correcting circuit (100) for correcting image data before being supplied to the LCD panel (50) so as to compensate the disturbance of the white balance caused by the change of the power of the light source (30), a counter (61) for counting an integrated on-state period of the light source; and a memory (51 ) for storing the integrated on-state period of the light source, which is connected to the counter and the control circuit; wherein the control circuit (81) changes the output of the power source (20) upon lapse of the integrated on-state period of the light source (30) stored by the memory (51) so as to keep luminance of the light source (30) constant.