A great number of photosensors employing various kinds of photo detecting materials (photosensor elements) have been developed. Photosensor apparatus is utilized in a variety of circumstances including the controlling of movement of passenger and freight elevators, automatic warehouse handling systems, etc. A
semiconductor photosensor device provides a linear output according to its ambient illumination (lightness), and mainly in a portable terminal unit. A semiconductor photosensor which converts an optical signal to an electric signal comprises a photosensor and a signal processing circuit. It is used as a sensor which reduces unnecessary power consumption, for example, by turning off the backlight and the LED of the key operation section when its surroundings are light. A line image sensor is one type of photosensor for detecting a one dimensional image and is typically used in facsimile machines.
