Image sensors with output noise reduction mechanisms

Abstract

An image sensor having readout noise reduction mechanisms is disclosed. The image sensor can include a first sampling transistor, a second sampling transistor connected to the first sampling transistor, an averaging transistor electrically connecting the first and second sampling transistors in series, a reset sampling transistor connected to the first and second sampling transistors, and a differential device connected to the reset sampling transistor and the first and / or second sampling transistors.

Description

technical field [0001] The present disclosure relates to image sensors with readout noise reduction mechanisms. In particular, aspects of the present disclosure relate to complementary metal oxide silicon (CMOS) image sensors with analog output averaging mechanisms. Background technique [0002] Unlike traditional cameras, which use film to capture and store images, today's digital cameras use solid-state image sensors to acquire images. Such image sensors are typically disposed on a fingernail-sized silicon chip containing millions of optoelectronic devices (eg, photodiodes) arranged in an array of pixels. During exposure, each optoelectronic device records the intensity, or brightness, of incident light by converting light energy into accumulated electrical charges. The brightness recorded by each optoelectronic device can then be read out and stored as a digital signal. [0003] FIG. 1 illustrates a representative solid-state image sensor 100 for acquiring images. Ima...

AI Technical Summary

Problems solved by technology

However, there are a number of disadvantages associated with this conventional technique

First, the additional on-chip / off-chip storage required to store successive frames during processing can greatly increase the required chip area and associated manufacturing costs

Second, averaging two consecutive frames reduces the available frame rate by 50%

Therefore, imaging setups implementing this technique may not be ideal for high-speed imaging applications

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