Patent ID: 7705986
Filing Date: 2010-04-27
Classification: G09G

Abstract:
1. An image display apparatus which presents an image to an observer, comprising: an image modulation unit which produces modulated light modulated according to an image signal; a polarization rotation liquid crystal cell which is capable of rotating a direction of polarization of the modulated light produced by the image modulation unit; a birefringent plate which receives the modulated light from the polarization rotation liquid crystal cell; a display optical unit which presents the modulated light from the birefringent plate to the observer; a sensor unit configured to measure a response characteristic of the polarization rotation liquid crystal cell, the sensor unit including a measurement light source which emits measurement light, a first polarization plate which has a first polarization direction and receives the measurement light from the measurement light source to output measurement light having the first polarization direction to the polarization rotation liquid crystal cell, a second polarization plate which has a second polarization direction and receives measurement light passed through the polarization rotation liquid crystal cell, a light receiving unit which receives measurement light passed through the second polarization plate, and a measurement unit which determines a response characteristic of the polarization rotation liquid crystal cell on the basis of a drive signal of the polarization rotation liquid crystal cell and the amount of measurement light received by the light receiving unit; and a liquid crystal cell drive unit which drives the polarization rotation liquid crystal cell by a drive signal adjusted on the basis of the response characteristic determined by the measurement unit.