Patent ID: 9588410
Date: 2017-03-07
CPC Classifications: G02B,G03B,H04N

Claim:
1. A projection type display device comprising: a lamp; a light valve configured to modulate input light from the lamp; a dimming unit which is provided between the lamp and the light valve and configured to mechanically shield light from the lamp; a projection unit configured to project light which is modulated by the light valve; a control unit configured to determine an input light amount which is caused to be input to the light valve on the basis of an input image signal which shows an image to be displayed, output an output image signal which is the decompressed input image signal according to the input light amount to the light valve, and determine a first dimming rate as a dimming rate of the lamp, and a second dimming rate as a dimming rate of the dimming unit based on the input light amount; a lamp driving unit configured to drive the lamp on the basis of the first dimming rate; and a dimming driving unit configured to drive the dimming unit on the basis of the second dimming rate, wherein when the maximum dimming rate in which a halogen cycle in the lamp normally functions is set to a first reference dimming rate and a maximum light amount input to the light valve by setting the first dimming rate and the second dimming rate to zero is set to the maximum light amount, the control unit increases the first dimming rate by setting the second dimming rate to zero until the first dimming rate reaches the first reference dimming rate and increases the second dimming rate after the first dimming rate has reached the first reference dimming rate, as the input light amount is decreased from the maximum light amount.