Electronic viewfinder having means for turning off a display device

摘要

The user observes a liquid crystal display panel screen positioned within a lens barrel through a lens. An infrared LED that emits pulses of light and a phototransistor are positioned in an eyecup against which the user's eye is pressed. An ambient light detecting circuit provides a control signal showing whether or not the user's eye is pressed against the eyecup and a control signal showing the amount of ambient light on the basis of the output signal of the phototransistor. A control circuit controls the luminance of a backlight unit according to the control signals. When the user's eye is not pressed against the eyecup, the display luminance is reduced to zero and the display is turned off. The display luminance is enhanced only when the amount of ambient light is large. Thus, needless power consumption can be avoided, and the screen can be satisfactorily observed even if a large quantity of light enters into the ocular part where the ambient light is bright.