Fingerprint Image Sensor Averaging Circuit for Low-Power Integration

Solution Overview

Problem

Existing image sensors face challenges in reducing area and power consumption, particularly when performing signal combination and averaging, which leads to increased complexity and resource utilization.

Innovation Solution

The image sensor design includes a pixel circuit array with an output circuit that simultaneously receives and averages output signals from multiple pixel circuits, reducing the number of output circuits and sampling circuits, and incorporates a sampling circuit for collecting signal average values, along with a photodiode, parasitic capacitor, and transistors for efficient signal processing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a separate fingerprint sensor is added to detect fingerprint information, then fingerprint detection capability is improved, but device complexity and space occupation increase

Engineering Contradiction:

Improvefingerprint detection capabilityVSAvoiddevice complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The imaging sensor is designed to perform both imaging functions and fingerprint detection functions using the same hardware components. By utilizing the existing light source, lens, and image sensor for both purposes, the patent eliminates the need for a separate fingerprint sensor, thereby reducing device complexity while maintaining fingerprint detection capability

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent merges the fingerprint detection function with the imaging sensor system. The imaging sensor captures both regular images and fingerprint information through the same optical path, combining multiple functions into a single integrated system rather than using separate components

Inventive Principle:

Principle #5Merging (Combining)

2Adaptability or versatility

If a separate fingerprint sensor is added to detect fingerprint information, then fingerprint detection capability is improved, but the sensor occupies additional space in the device

Engineering Contradiction:

Improvefingerprint detection capabilityVSAvoidsensor space occupation

Core Design Contradiction:

Adaptability or versatilityVSArea of stationary object

Solution Approach 1:

The imaging sensor is designed to perform both imaging functions and fingerprint detection functions using the same hardware components. By utilizing the existing light source, lens, and image sensor for both purposes, the patent eliminates the need for a separate fingerprint sensor, thereby reducing device complexity while maintaining fingerprint detection capability

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent merges the fingerprint detection function with the imaging sensor system. The imaging sensor captures both regular images and fingerprint information through the same optical path, combining multiple functions into a single integrated system rather than using separate components

Inventive Principle:

Principle #5Merging (Combining)

3Measurement precision

If the imaging sensor continuously operates in full resolution mode to improve detection accuracy, then detection precision is improved, but power consumption increases

Engineering Contradiction:

Improvedetection precisionVSAvoidpower consumption

Core Design Contradiction:

Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The imaging sensor dynamically adjusts its resolution based on the detection needs. When fingerprint detection is required, the sensor operates at full resolution to ensure accurate fingerprint capture. For regular imaging or when fingerprint detection is not needed, the sensor can operate at lower resolution, thereby reducing power consumption while maintaining detection precision when required

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes the operational parameters of the imaging sensor based on the detection mode. By adjusting resolution, exposure time, and other parameters dynamically according to whether fingerprint detection or regular imaging is being performed, the system optimizes power consumption while ensuring high detection precision when fingerprint detection is required

Inventive Principle:

Principle #35Parameter changes

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 design significantly reduces the area and power consumption of the image sensor while enabling efficient signal combination and averaging, improving performance by eliminating reset noise through correlated double sampling.

Implementation Method 1

the imaging sensor may include a first unit configured to obtain a first image of a fingerprint

Methodology Applied

Scientific EffectReflection: Reflection

Data Source

PatentEP3985555B1Image sensor, fingerprint detection apparatus, and electronic device

Publication Date: 2023.10.11 SHENZHEN GOODIX TECH CO LTD

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AI summary

An image sensor, a fingerprint detection apparatus, and an electronic device are provided. The image sensor includes a pixel circuit array, wherein each pixel circuit is configured to generate an output signal according to a received light signal; and an output circuit is configured to simultaneously receive output signals of a plurality of pixel circuits in the pixel circuit array, and output a signal average value of the output signals of the plurality of pixel circuits. The image sensor has a small area and power consumption.