Patent ID: 8018450

Claim:
An electrooptic device comprising: a display panel; an illuminating unit that emits light onto the display panel; an ambient-light measuring unit that measures an illuminance of ambient light; a luminance control unit including a light control profile for obtaining an optimum surface luminance of the display panel, the luminance control unit obtaining the optimum surface luminance on the basis of the measured illuminance of the ambient light using the light control profile, and controlling the luminance of the light to be emitted from the illuminating unit to provide the display panel with the optimum surface luminance, wherein: the light control profile is set such that light-emitting brightness of the illuminating unit becomes large when irradiation of a surrounding environment light is large, and the light-emitting brightness of the illuminating unit becomes small when irradiation of the surrounding environment light is small, and the light control profile has a relationship in which the optimum surface luminance forms a concave quadratic curve with respect to a logarithm of the illuminance of the ambient light; a display-mode switching unit that switches the display panel to a transmission display mode when the illuminance of the ambient light measured by the ambient-light measuring unit is lower than a predetermined illuminance, and switches the display panel to a reflection display mode when the illuminance of the ambient light is higher than the predetermined illuminance; and a storage unit that stores a gamma value for a transmission display for the transmission display mode and a gamma value for a reflection display for the reflection display mode as a plurality of tables; wherein when the display panel is switched to the transmission display mode by the display-mode switching unit, the gamma value for the transmission display is obtained from the plurality of tables stored in the storage unit, and the gamma value for the transmission display is applied; and when the display panel is switched to the reflection display mode by the display-mode switching unit, the gamma value for the reflection display is obtained from the plurality of tables stored in the storage unit, and the gamma value for the reflection display is applied.