Patent ID: 7600875

Claim:
An image display apparatus for projecting a video on a projection plane, comprising: a chart image signal generation unit which is supplied with chart display information designating a display position and a display size, on the projection plane, of a chart image for measuring a distance to the projection plane, and which generates a chart image signal in which the display position and the display size of the chart image are set based on the supplied chart display information; a projection unit which converts the chart image signal generated by the chart image signal generation unit into projection light to project the chart image as a part of a projection video on the projection plane based on the display position and the display size designated by the chart display information supplied to the chart image signal generation unit; a sensor unit which receives light from the chart image projected as part of the projection video on the projection plane, and which obtains sensor data regarding the distance to the projection plane based on an image imaged on an imaging surface thereof; and a chart display information supply unit which determines a viewable range of the sensor unit, sets the display position and the display size of the chart image on the projection plane based on the determined viewable range of the sensor unit, and supplies the chart display information designating the set display position and display size to the chart image signal generation unit.