Patent ID: 7960679

Claim:
A photo detector device configured for use with a display device, the photo detector device comprising: a photosensitive transistor formed on a substrate of the display device, the photosensitive transistor being capable of detecting an optical signal and converting the optical signal into a current signal; a converter formed on the substrate of the display device, the converter being capable of receiving the current signal on a first conductive line and converting the current signal into a voltage signal, the voltage signal being used to determine the position of an optical source, the converter comprising: a first resistive device coupled between the first conductive line and a reference voltage line, wherein the first resistive device includes a first transistor, the first transistor including a gate coupled to the first conductive line, a drain coupled to the first conductive line, and a source coupled to the reference voltage line; and a first capacitive device coupled in parallel with the first resistive device between the first conductive line and the reference voltage line.