Patent ID: 9741290
Date: 2017-08-22
CPC Classifications: G06F,G09G

Claim:
1. A multi-mode display, comprising: an array of light sensing and emitting units (LSEUs); a decoder configured to generate addresses for accessing one or more LSEUs in the array of LSEUs; and a controller configured to control the array of LSEUs using the addresses, wherein each LSEU in the array of LSEUs comprises a light sensing and emitting component (LSEC), an emitting circuit configured to generate light using the LSEC, and a sensing circuit configured to detect light using the LSEC, wherein the sensing circuit includes a read driver, wherein a gate terminal of the read driver is directly connected to a diode in the LSEC and a cathode terminal of the diode is directly connected to a power source through a drain terminal of a pull up transistor and a source terminal of the pull up transistor is directly connected to the power source, wherein an anode terminal of the diode is directly connected to a circuit ground, and wherein the gate terminal of the read driver is controlled in part by a voltage drop caused by the light detected by the sensing circuit, and wherein a current through the read driver is proportional to a square of a difference between a gate-to-source voltage modified by the voltage drop and a threshold voltage of the read driver, wherein the sensing circuit comprises a first switch and a first sensing capacitor configured to sample a first leakage current during an initialization phase of a light sensing operation of the LSEC, and the sensing circuit further comprises a second switch and a second sensing capacitor configured to sample a second leakage current during a sensing phase of the light sensing operation of the LSEC, wherein a difference between the first leakage current and the second leakage current is used to detect an image on the multi-mode display.