Patent ID: 8217927

Claim:
A display unit that has a display area having a switching element for each pixel on a substrate, the display unit comprising: a light intensity detector that includes a first photodetector having a first ambient light photosensor, a second photodetector having a second ambient light photosensor, and an ambient light photosensor reader, and outputs as a light intensity signal a light intensity detected by the first photodetector and the second photodetector; and a light-reducing unit formed in a region that overlies at least one of the first ambient light photosensor and the second ambient light photosensor in a plane view, and differentiates the amount of incident light on the first ambient light photosensor and the second ambient light photosensor; the first photodetector including a first photodetection circuit that outputs a first output signal based on incident light entering the first ambient light photosensor to the ambient light photosensor reader; the second photodetector including a second photodetection circuit that outputs a second output signal based on incident light entering the second ambient light photosensor to the ambient light photosensor reader; and the ambient light photosensor reader including: a photodegradation factor calculator that: calculates a measurement ratio that is a ratio between the first output signal and the second output signal, and calculates a photodegradation reparation factor that is a ratio between the measurement ratio and an initial ratio that is the measurement ratio obtained in a prearranged initial state, the photodegradation reparation factor indicating an amount of photodegradation of the first and second ambient light photosensors; a photodegradation rate calculator that derives a photodegradation rate of the first or second output signal based on the photodegradation reparation factor; and a light signal output unit that outputs a light intensity signal based on the first or second output signal in an initial state determined from the photodegradation rate.