US 11,837,186 B2
Liquid crystal projector
Daigo Hokazono, Suwa (JP); Toru Aoki, Shiojiri (JP); and Kazuhisa Mizusako, Shiojiri (JP)
Assigned to SEIKO EPSON CORPORATION, Tokyo (JP)
Filed by SEIKO EPSON CORPORATION, Tokyo (JP)
Filed on Apr. 21, 2022, as Appl. No. 17/726,188.
Claims priority of application No. 2021-072400 (JP), filed on Apr. 22, 2021.
Prior Publication US 2022/0343869 A1, Oct. 27, 2022
Int. Cl. G09G 3/36 (2006.01); G09G 3/00 (2006.01); G09G 3/20 (2006.01)
CPC G09G 3/36 (2013.01) [G09G 3/002 (2013.01); G09G 3/2003 (2013.01); G09G 3/2007 (2013.01); G09G 3/3648 (2013.01); G09G 2320/0252 (2013.01); G09G 2320/0257 (2013.01); G09G 2320/0261 (2013.01); G09G 2320/0285 (2013.01); G09G 2320/0666 (2013.01)] 5 Claims
OG exemplary drawing
 
1. A liquid crystal projector, comprising:
a display control circuit configured to process image data of a first color, of image data specifying a gray scale level of a pixel and output the image data of the first color as a first data signal, and to process image data of a second color different from the first color, of the image data and output the image data of the second color as a second data signal;
a first liquid crystal panel including a first liquid crystal element to which a voltage is applied in accordance with the first data signal, the first liquid crystal element emitting incident light of the first color as first emission light at a ratio corresponding to an applied voltage;
a second liquid crystal panel including a second liquid crystal element to which a voltage is applied in accordance with the second data signal, the second liquid crystal element emitting incident light of the second color as second emission light at a ratio corresponding to an applied voltage; and
a prism configured to synthesize the first emission light and the second emission light, and emit the synthesized emission light as synthesized light, wherein
the display control circuit
includes a gray scale level converter for, when a voltage applied to the first liquid crystal element corresponding to a gray scale level specified by the image data of the first color is less than a first threshold value, correcting the first data signal, to increase a voltage applied to the first liquid crystal element to be higher than a voltage corresponding to the gray scale level, and when a voltage applied to the second liquid crystal element corresponding to a gray scale level specified by the image data of the second color is less than a second threshold value, correcting the second data signal, to increase a voltage applied to the second liquid crystal element to be higher than a voltage corresponding to the gray scale level,
does not perform overdrive processing for the first liquid crystal element when a voltage applied to the first liquid crystal element decreases due to a change in a gray scale level specified by the image data of the first color, and
performs overdrive processing for the second liquid crystal element when a voltage applied to the second liquid crystal element decreases due to a change in a gray scale level specified by the image data of the second color;
the overdrive processing includes
a first correction for increasing an applied voltage to the first liquid crystal element or the second liquid crystal element, and
a second correction for decreasing an applied voltage to the second liquid crystal element; and
the display control circuit
performs the first correction for the first liquid crystal element, when a voltage applied to the first liquid element is increased due to a change in a gray scale level specified by the image data of the first color,
performs the first correction for the second liquid crystal element, when a voltage applied to the second liquid element is increased due to a change in a gray scale level specified by the image data of the second color, and
performs the second correction for the second liquid crystal element, when a voltage applied to the second liquid crystal element is decreased.