Sliding Fingerprint Sensor Layout for Multi-Direction Recognition

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Solution Overview

Problem

Existing sliding fingerprint recognition devices can only detect fingerprints if the finger slides in a specific direction, limiting their application and requiring long distance sliding for full fingerprint detection.

Innovation Solution

A fingerprint recognition device with a matrix arrangement of rectangle-shaped recognition areas, where electrodes are aligned diagonally across each area, allowing detection in multiple directions and increasing sensitivity with fewer electrodes, reducing cost.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If electrodes are arranged in a single direction (1×N) for sliding type fingerprint recognition, then the device saves space, but the finger can only slide in a specific direction and full fingerprint detection requires long distance sliding

Engineering Contradiction:
Improvedevice sizeVSAvoidsliding direction flexibility
Core Design Contradiction:
Volume of moving objectVSAdaptability or versatility

Solution Approach 1:

The patent transitions from a one-dimensional linear electrode arrangement (1×N) to a two-dimensional matrix arrangement (M×N) of electrodes. This dimensional change enables the electrode array to detect fingerprint patterns regardless of the sliding direction, as the multi-directional electrode coverage captures ridge patterns whether the finger slides horizontally, vertically, or diagonally across the sensor surface.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The matrix arrangement of electrodes creates a universal detection system that functions for multiple sliding directions simultaneously. Unlike the directional 1×N arrangement that only works for one specific sliding path, the M×N matrix provides omnidirectional detection capability, making the device adaptable to various user sliding behaviors without requiring separate detection mechanisms for different directions.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Device complexity

If electrodes are arranged in a single direction (1×N) for sliding type fingerprint recognition, then the device structure is simplified, but full fingerprint detection requires long distance sliding

Engineering Contradiction:
Improveelectrode arrangement complexityVSAvoidfingerprint detection completeness
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

By expanding from one-dimensional linear arrangement to two-dimensional matrix arrangement, the patent increases the detection coverage area. This dimensional expansion allows the electrode array to capture complete fingerprint patterns within a shorter sliding distance, as the multi-row electrode structure intercepts ridge patterns across different positions simultaneously, eliminating the need for long-distance sliding to achieve full fingerprint capture.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Measurement precision

If N×N electrodes are arranged for pressing type fingerprint recognition, then full fingerprint information can be captured, but the device requires pressing action and occupies more space

Engineering Contradiction:
Improvefingerprint information completenessVSAvoiddevice size
Core Design Contradiction:
Measurement precisionVSVolume of moving object

Solution Approach 1:

The patent segments the large N×N electrode array into multiple smaller M×N matrix blocks arranged in a larger matrix configuration. This segmentation approach maintains the comprehensive fingerprint detection capability of the original N×N design while enabling a sliding recognition mode that requires less contact pressure and reduces the effective sensing area needed at any given moment, thereby reducing the perceived device size and enabling portable applications.

Inventive Principle:
Principle #1Segmentation

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

Enables full fingerprint recognition without directional restrictions and enhances sensitivity by allowing finger sliding in any direction, expanding the device's application scope while reducing the number of electrodes needed.

Implementation Method 1

EP 0 942 259 A1 discloses a distance sensor having a first capacitor plate which is positioned facing a second capacitor plate whose distance is to be measured. In the case of fingerprinting, the second capacitor plate is defined directly by the skin surface of the finger being printed

Methodology Applied
Scientific EffectCapacitance: Capacitance

Data Source

PatentEP3249573B1Fingerprint recognition device and touch apparatus
Publication Date: 2022.04.27 BOE TECHNOLOGY GROUP CO LTD
  • EP3249573B1 patent drawingFigure 1~2
  • EP3249573B1 patent drawingFigure 3~4a
  • EP3249573B1 patent drawingFigure 4b

AI summary

A fingerprint recognition device and a touch apparatus comprise a plurality of fingerprint recognition areas (100) with a rectangle shape arranged in a matrix. Each of the fingerprint recognition areas (100) comprises a plurality of mutually independent fingerprint recognition electrodes (110) arranged along a diagonal direction of the fingerprint recognition area (100). Arrangement directions of the fingerprint recognition electrodes (110) in the respective fingerprint recognition areas (100) are same. Because the fingerprint recognition electrodes (110) in the respective fingerprint recognition areas (100) are arranged in a same diagonal direction, the fingerprint recognition electrodes (110) belonging to a same or adjacent fingerprint recognition area(s) (100) can detect full fingerprint information when a finger slides on the fingerprint recognition device in any one of a plurality of directions, so that the fingerprint is recognized. The sliding type fingerprint recognition device is not restricted by the sliding direction of the finger, and thus an application scope of the sliding type fingerprint recognition device can be expanded.