Patent ID: 6697114
Filing Date: 2004-02-24
Classification: H04N

Abstract:
An active pixel sensor disposed on a semiconductor substrate comprising:a first capacitive storage element having a first terminal connected to a fixed potential and a second terminal; a second capacitive storage element having a first terminal connected to a fixed potential and a second terminal; a first photodiode having a first terminal connected to a fixed potential and a second terminal, said first photodiode having a first size; a second photodiode having a first terminal connected to a fixed potential and a second terminal, said second photodiode having a second size smaller than said first size; a first semiconductor reset switch having a first terminal connected to said second terminal of said first photodiode and a second terminal connected to a first reset potential that reverse biases said first photodiode; a second semiconductor reset switch having a first terminal connected to said second terminal of said second photodiode and a second terminal connected to a second reset potential that reverse biases said second photodiode; a first semiconductor transfer switch having a first terminal connected to said second terminal of said first photodiode and a second terminal connected to said second terminal of said first capacitive storage element; a second semiconductor transfer switch having a first terminal connected to said second terminal of said second photodiode and a second terminal connected to said second terminal of said second capacitive storage element; a first semiconductor source-follower amplifier having an input connected to said second terminal of said first capacitive storage element and an output; a second semiconductor source-follower amplifier having an input connected to said second terminal of said second capacitive storage element and an output; said first and second semiconductor reset switches and said first and second semiconductor transfer switches each having a control element connected to a control circuit for selectively activating said first and second semiconductor reset switches and said first and second semiconductor transfer switches.