REDUCED PIXEL AREA IMAGE SENSOR

• US 20110122307A1
• Filed: 01/26/2011
• Published: 05/26/2011
• Est. Priority Date: 03/15/2007
• Status: Active Grant

• Current Assignee: Omnivision Technologies Incorporated (Will Semiconductor Co., Ltd. Shanghai)
• Original Assignee: Omnivision Technologies Incorporated (Will Semiconductor Co., Ltd. Shanghai)
• Inventors: Parks, Christopher
• Granted Patent: US 8,294,187 B2
• Time in Patent Office: Days
• US Class Current: 348/308
• CPC Class Codes: H01L 27/14603 Special geometry or disposition of pixel-elements, address-lines or gate-electrodes
• CPC Class Codes: H01L 27/14609 Pixel-elements with integrated switching, control, storage or amplification elements scanning details of imagers (circuitry of solid-state image sensors H04N25/00); circuitry of imagers H04N25/70
• CPC Class Codes: H01L 27/14641 Electronic components shared by two or more pixel-elements, e.g. one amplifier shared by two pixel elements
• CPC Class Codes: H04N 25/00 Circuitry of solid-state image sensors [SSIS]; Control thereof
• CPC Class Codes: H04N 25/778 comprising amplifiers shared between a plurality of pixels, i.e. at least one part of the amplifier must be on the sensor array itself

Abstract

An image sensor that includes a plurality of pixels disposed on a substrate, each pixel includes at least one photosensitive region that collects charges in response to incident light; a charge-to-voltage conversion node for sensing the charge from the at least one photosensitive region and convening the charge to a voltage; an amplifier transistor having a source connected to an output node, having a gate connected to the charge-to-voltage conversion node and having a drain connected to at least a portion of a power supply node; and a reset transistor connecting the output node and the charge-to-voltage conversion node.

Claims

1. A method for reading out charge from a row of pixels in an image sensor, wherein each pixel in the row includes a photodetector, a floating diffusion, and each column output line in the image sensor is connected to a load transistor, the method comprising:

turning off the load transistors;

setting the column output lines to a first voltage level;

resetting the floating diffusions by pulsing the reset transistors in the pixels in the row to be read out;

turning on the load transistors and set the column output lines to a second voltage level; and

reading out signals from the pixels in the row.

2. The method as in claim 1, wherein reading out signals from the pixels in the row comprises:

reading out reset signals on the floating diffusions in the row;

transferring charge from the photodetectors to the floating diffusions in the row by pulsing the transfer gates in the row;

reading out image signals on the floating diffusions in the row; and

turning on the reset transistors in the pixels in the row.