Patent ID: 8477125

Claim:
A photo sensor in a non-pixel region of a display device, the photo sensor comprising: a plurality of PIN photo diodes connected to one another in parallel, each PIN photo diode including an intrinsic region between an N-type doping region and a P-type doping region, bottom surfaces of the intrinsic region and the N-type and P-type doping regions in each PIN photo diode being coplanar, wherein: the plurality of PIN photo diodes are configured to absorb light emitted from an organic light-emitting diode in a pixel region of the display device and to convert the absorbed light into a corresponding electrical signal that represents an actual luminance value of the organic light-emitting diode to compare the actual luminance value to a predetermined luminance value, the plurality of PIN photo diodes in the photo sensor are capable of maintaining a constant luminance of light generated in the organic light-emitting diode by converting the absorbed light into the corresponding electrical signal such that the actual luminance value is generated by the plurality of PIN photo diodes for comparing with the predetermined luminance value, when the electrical signal outputted from the photo sensor is lower than the predetermined luminance value, a luminance of light emitted by the organic light-emitting diode is increased, and when the electrical signal outputted from the photo sensor is higher than the predetermined luminance value, the luminance of light emitted by the organic light-emitting diode is reduced.