| 摘要 |
Difference values that are defined as values representing a magnitude of an influence exerted upon an illuminance of an ambient environment according to a brightness component of an input video signal and are set so as to correspond to the brightness component based on a result of measuring the magnitude of the influence previously, a plurality of illuminance ranges set by dividing an extent of the illuminance of the ambient environment, and brightness correction characteristic data for correcting the brightness component according to each of the illuminance ranges are stored. The brightness component is detected, so that the difference values are selected based on the detected value (S101), an illuminance sensor measures the illuminance of the ambient environment repeatedly (S102), one of the illuminance ranges is selected based on illuminance detection values obtained by previous and current measurements and the selected difference values (S103), and the brightness correction characteristic data according to the selected illuminance range is selected, so that the brightness component of the input video signal is corrected (S104). By reflecting the influence of reflected light from a screen due to image projection based on the input video signal, the brightness can be corrected stably according to a change in the brightness of the use environment. |
