Fingerprint Sensor Selective Region Powering

Solution Overview

Problem

Conventional large-area fingerprint sensors require driving all sensing units and reading out signals from multiple units, leading to inefficient fingerprint sensing and image acquisition due to the need to power and read all sensing regions simultaneously.

Innovation Solution

The fingerprint sensor selectively provides power to only the sensing regions corresponding to the current fingerprint sensing area, allowing for efficient fingerprint sensing by only activating and reading the necessary sensing units, thereby reducing the overall sensing time and energy consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If all sensing units are driven to perform sensing in each fingerprint sensing operation, then the fingerprint sensing coverage area is ensured, but the sensing time and energy consumption increase

Engineering Contradiction:

Improvefingerprint sensing coverage areaVSAvoidsensing time

Core Design Contradiction:

Area of stationary objectVSLoss of time

Solution Approach 1:

The sensing array is divided into multiple sensing regions, each capable of independent operation. The control circuit selectively activates only the sensing region where the fingerprint is detected, rather than driving all sensing units simultaneously. This segmentation allows the system to maintain full coverage capability while reducing active sensing time and energy consumption.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The system dynamically adjusts which sensing regions are activated based on real-time fingerprint detection. The control circuit receives touch information, determines the appropriate sensing region, and selectively powers on only that region for fingerprint sensing. This dynamic activation pattern enables the system to adapt to different fingerprint positions and reduce overall sensing time.

Inventive Principle:

Principle #15Dynamics

2Area of stationary object

If all sensing units are driven to perform sensing in each fingerprint sensing operation, then the fingerprint sensing coverage area is ensured, but the energy consumption increases

Engineering Contradiction:

Improvefingerprint sensing coverage areaVSAvoidenergy consumption

Core Design Contradiction:

Area of stationary objectVSUse of energy by stationary object

Solution Approach 1:

The sensing array is divided into multiple sensing regions, each capable of independent operation. The control circuit selectively activates only the sensing region where the fingerprint is detected, rather than driving all sensing units simultaneously. This segmentation allows the system to maintain full coverage capability while reducing active sensing time and energy consumption.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The system dynamically adjusts which sensing regions are activated based on real-time fingerprint detection. The control circuit receives touch information, determines the appropriate sensing region, and selectively powers on only that region for fingerprint sensing. This dynamic activation pattern enables the system to adapt to different fingerprint positions and reduce overall sensing time.

Inventive Principle:

Principle #15Dynamics

3Area of stationary object

If sensing results of multiple sensing units are read out through a multiplexer in a time-sharing manner, then the full sensing array is covered, but the image acquisition efficiency decreases

Engineering Contradiction:

Improvesensing array coverageVSAvoidimage acquisition efficiency

Core Design Contradiction:

Area of stationary objectVSProductivity

Solution Approach 1:

The sensing array is divided into multiple sensing regions with dedicated readout circuits for each region. Instead of using a single multiplexer to time-share reading across all sensing units, each active sensing region has its own dedicated readout path. This eliminates the time-sharing bottleneck and allows parallel reading of sensing results from multiple regions simultaneously, significantly improving image acquisition efficiency.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The readout architecture transitions from a single-dimensional time-sharing approach (one region read at a time through MUX) to a multi-dimensional parallel readout approach where multiple sensing regions can be read simultaneously through dedicated circuits. This dimensional change in the readout structure enables parallel processing of fingerprint data from different regions, boosting overall acquisition speed.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Data Source

PatentUS11126812B2Fingerprint sensor

Publication Date: 2021.09.21 EGIS TECH

AI summary

The invention provides a fingerprint sensor including a sensing array. The sensing array includes a plurality of sensing units to form a plurality of sensing regions arranged in an array. Each of the plurality of sensing regions includes at least one column of sensing units. A first part of the plurality of sensing regions receives a power signal to perform fingerprint sensing. A second part of the plurality of sensing regions does not receive a power signal. Therefore, the fingerprint sensor of the invention can provide a fast and energy-saving large-area fingerprint sensing effect.