Patent ID: 9148602
Filing Date: 2015-09-29
Classification: H01L,H04N

Abstract:
1. An image sensor comprising: a pixel array including a plurality of unit pixels, each unit pixel having a photodiode, a transfer transistor, a reset transistor, a drive transistor, a select transistor, a first capacitor, a sensing node, and a first switch between the first capacitor and the sensing node; an analog to digital converter comprising a second switch and a second capacitor in parallel with a third switch and a third capacitor, the analog to digital converter configured to sample first and second analog sensing signals from the pixel array, store the first analog sensing signal in the second capacitor and the second analog sensing signal in the third capacitor, and convert the sampled the first and second analog sensing signals into a digital sensing signal; and a timing controller configured to (i) activate a transfer signal which turns on the transfer transistor after sampling the first analog sensing signal, (ii) inactivate the transfer signal before sampling the second analog sensing signal in a low illuminance environment, (iii) inactivate the transfer signal after sampling the second analog sensing signal in a high illuminance environment, (iv) turn on the first switch before sampling the second analog sensing signal in the high illuminance environment, and (v) store the first analog sensing signal before activating the transfer signal and store the second analog sensing signal after activating the transfer signal in both low and high illuminance environments.