Image sensor with gain control

Abstract

An image sensor having a plurality of pixels; each pixel includes one or more photosensitive elements that collect charge in response to incident light; one or more transfer mechanisms that respectively transfer the charge from the one or more photosensitive elements; a charge-to-voltage conversion region having a capacitance, and the charge-to-voltage region receives the charge from the one or more photosensitive elements; a first reset transistor connected to the charge-to-voltage conversion region; a second reset transistor connected to the first reset transistor, which in combination with the first reset transistor, selectively sets the capacitance of the charge-to-voltage conversion regions from a plurality of capacitances.

1 . An image sensor having a plurality of pixels;
 each pixel comprising:
 (a) one or more photosensitive elements that collect charge in response to incident light; 
 (b) one or more transfer mechanisms that respectively transfer the charge from the one or more photosensitive elements; 
 (c) a charge-to-voltage conversion region having a capacitance, and the charge-to-voltage region receives the charge from the one or more photosensitive elements; 
 (d) a first reset transistor connected to the charge-to-voltage conversion region; 
 (e) a second reset transistor connected in series to the first reset transistor, which in combination with the first reset transistor, selectively sets the capacitance of the charge-to-voltage conversion regions from a plurality of capacitances; and 
 (f) one or more additional transistors connected either in series or parallel to the first reset transistor for further selectively setting the capacitance of the charge-to-voltage conversion regions from a plurality of capacitances. 
   
   
   
       2 . The image sensor as in  claim 1 , wherein the charge-to-voltage conversion region is a floating diffusion. 
   
   
       3 . The image sensor as in  claim 1 , wherein the image sensor is included in an image capture device.