Patent ID: 8587755

Claim:
A display apparatus comprising: at least one display cell having a display circuit; at least one light receiving cell including a light receiving element; at least one reference cell having a configuration substantially equivalent to a configuration of the light receiving cell and having a shield structure that blocks light from the light receiving element of the reference cell; and a signal processing circuit performing differential signal processing of an output signal of the light receiving cell and an output signal of the reference cell, and further wherein the display apparatus is comprised of a plurality of the display cells arranged in a matrix and a plurality light receiving cells and reference cells mixed within the matrix of light receiving cells, and further wherein there are a plurality of light receiving cells and reference cells and a black mask is provided as a layer above the light receiving cells and the reference cells with an opening in the black mask for the light receiving cells and further wherein each pair of a plurality of adjacent light receiving cells and reference cells have an output connected directly to an input of an operational amplifier of the signal processing circuit such that each operational amplifier has an input from a reference cell and a light receiving cell.