Image Sensor Load Circuit Reducing Area and Power

Solution Overview

Problem

There is a need to minimize the size and power consumption of CMOS image sensors used in electronic devices, as they continue to be integrated into thinner and more power-efficient products.

Innovation Solution

The design includes a column signal line connected to pixel sensors, a comparator circuit for signal comparison, an ADC circuit for digital conversion, and a load circuit acting as a common device for the pixel sensors and comparator circuit, with a PMOS transistor and active load circuit configurations, enabling efficient signal processing and power management.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a separate load circuit is provided for each pixel sensor and comparator circuit, then signal processing reliability is improved, but device area and power consumption increase

Engineering Contradiction:

Improvesignal processing reliabilityVSAvoiddevice area

Core Design Contradiction:

ReliabilityVSArea of stationary object

Solution Approach 1:

The load circuit is designed to serve multiple functions simultaneously: it acts as a load device for the comparator circuit and as a load device for the pixel sensor. This multi-functional design eliminates the need for separate load circuits for each component, thereby reducing the overall device area while maintaining signal processing reliability through proper signal loading and biasing for both circuits.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent merges the load circuit functions into a single shared circuit that is commonly connected to both the comparator circuit and the pixel sensor. This consolidation combines what would traditionally be separate circuits into one unified structure, reducing the total number of components and circuit area while preserving the necessary signal processing capabilities for both the comparator and pixel sensor operations.

Inventive Principle:

Principle #5Merging (Combining)

2Reliability

If a separate load circuit is provided for each pixel sensor and comparator circuit, then signal processing reliability is improved, but power consumption increases

Engineering Contradiction:

Improvesignal processing reliabilityVSAvoidpower consumption

Core Design Contradiction:

ReliabilityVSUse of energy by stationary object

Solution Approach 1:

The load circuit is designed to serve multiple functions simultaneously: it acts as a load device for the comparator circuit and as a load device for the pixel sensor. This multi-functional design eliminates the need for separate load circuits for each component, thereby reducing the overall device area while maintaining signal processing reliability through proper signal loading and biasing for both circuits.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent merges the load circuit functions into a single shared circuit that is commonly connected to both the comparator circuit and the pixel sensor. This consolidation combines what would traditionally be separate circuits into one unified structure, reducing the total number of components and circuit area while preserving the necessary signal processing capabilities for both the comparator and pixel sensor operations.

Inventive Principle:

Principle #5Merging (Combining)

3Area of stationary object

If the load circuit is configured as a common load device, then device area and power consumption are reduced, but circuit complexity increases

Engineering Contradiction:

Improvedevice areaVSAvoidcircuit complexity

Core Design Contradiction:

Area of stationary objectVSDevice complexity

Solution Approach 1:

The load circuit is designed to serve multiple functions simultaneously: it acts as a load device for the comparator circuit and as a load device for the pixel sensor. This multi-functional design eliminates the need for separate load circuits for each component, thereby reducing the overall device area while maintaining signal processing reliability through proper signal loading and biasing for both circuits.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This configuration reduces the size and power consumption of image sensors while maintaining effective signal conversion and processing capabilities, enhancing the performance of electronic devices.

Implementation Method 1

a photoelectric conversion device configured to generate charges corresponding to an incident light

Methodology Applied

Scientific EffectPhotoelectric conversion: Photoelectric Effect

Data Source

PatentUS9374527B2Image sensor and image processing apparatus using the same

Publication Date: 2016.06.21 SAMSUNG ELECTRONICS CO LTD

AI summary

An image sensor senses object information and converts the sensed object information into an electrical signal. An image processing apparatus uses the image sensor. The image sensor includes a column signal line connected to output terminals of a plurality of pixel sensors, a comparator circuit configured to output a signal corresponding to a comparison result of a signal output to the column signal line and a reference signal, an ADC circuit configured to convert an analog signal corresponding to an optical signal sensed by the pixel sensor selected from the plurality of pixel sensors connected to the column signal line into digital data based on the signal output from the comparator circuit and, a load circuit connected in series to the comparator circuit between the column signal line and a ground terminal, wherein the load circuit is configured as a common load device of the plurality of pixel sensors connected to the column signal line and the comparator circuit.