Fingerprint Sensor Light Guiding Structure

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional concealed biological identification devices lack a touch guiding function in darkness and have a large, thick design, which does not meet consumer preferences for diversity and security in biological identification.

Innovation Solution

A sensor apparatus with a transparent cover, ink layer, light-emitting module, and reflecting layers to guide users in the dark, integrated with a biological sensor for fingerprint or heart rate detection, featuring a compact and simple structure with a light shielding layer and flexible printed circuit board for enhanced functionality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If a thick backlight module is used to implement uniform light transmission, then the light guiding function is improved, but the product thickness increases and becomes unsuitable for compact sensor devices

Engineering Contradiction:
Improvelight guiding functionVSAvoidproduct thickness
Core Design Contradiction:
Illumination intensityVSLength of stationary object

Solution Approach 1:

The patent merges the backlight module with the fingerprint sensor into a single integrated structure. The light-emitting component and light-receiving component are positioned on opposite sides of the fingerprint sensing area, eliminating the need for separate thick backlight modules while achieving both illumination and sensing functions in a compact form factor

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The integrated module serves multiple functions: it provides illumination for the fingerprint sensor, acts as the sensing structure itself, and guides user interaction through light patterns. This multi-functionality eliminates the need for separate dedicated backlight components, reducing overall device thickness

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

2Reliability

If a conventional concealed biological identification device structure is used, then the biological identification function is achieved, but the device lacks touch guiding function in darkness and has limited functionality

Engineering Contradiction:
Improvebiological identification functionVSAvoidtouch guiding function and functionality diversity
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The device integrates multiple functions into a single system: fingerprint recognition, heart rate detection, and touch guidance. The same light-emitting and light-receiving components serve both illumination for sensing and visual guidance for users, enhancing versatility without adding separate functional modules

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

Solution Approach 2:

The device uses different light colors to indicate different operational states and provide touch guidance. By changing light color, the system communicates with users in dark environments and provides feedback without requiring additional display components, maintaining compactness while enhancing adaptability

Inventive Principle:
Principle #32Color changes

3Measurement precision

If separate structures are used for light emission and sensing, then the biological identification accuracy is maintained, but the device complexity and size increase

Engineering Contradiction:
Improvebiological identification accuracyVSAvoidstructure complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent combines the light-emitting module and light-receiving module into a single integrated fingerprint sensing device. Both components are positioned in close proximity with their optical axes aligned, maintaining measurement precision while significantly reducing structural complexity compared to separate discrete components

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The light-emitting and light-receiving components are positioned on opposite sides of the fingerprint sensing area in a vertical arrangement. This dimensional configuration allows optical paths to cross without interference while maintaining compact form factor and simplifying overall device structure

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

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

The sensor apparatus provides a touch guiding function, improves user experience in dark environments, and enhances security through liveness detection and compact design suitable for mobile terminals.

Implementation Method 1

at least one light-emitting module, the light-emitting module being arranged as parallel to the sensor

Methodology Applied
Scientific EffectLight emission: Light Emitting Diode

Implementation Method 2

an upper reflecting layer and a lower reflecting layer configured to reflect light emitted from the at least one light -emitting module

Methodology Applied
Scientific EffectLight reflection: Reflection

Implementation Method 3

a light transmitting glue layer, the light transmitting glue layer being arranged between the upper reflecting layer and the lower reflecting layer

Methodology Applied
Scientific EffectLight transmission: Refraction

Implementation Method 4

a lower surface of the cover being provided with an ink layer, the ink layer configured to shield the ligh

Methodology Applied
Scientific EffectLight absorption: Absorption (EM radiation)

Implementation Method 5

a biological sensor configured to collect biological information of the users, the sensor being arranged below the cover

Methodology Applied
Scientific EffectOptical detection: Photoelectric Effect

Data Source

PatentEP3340108B1Sensor device and mobile terminal
Publication Date: 2020.12.09 SHENZHEN GOODIX TECH CO LTD
  • EP3340108B1 patent drawingFigure 1a~1b
  • EP3340108B1 patent drawingFigure 2~3

AI summary

The present application provides a sensor apparatus and a mobile terminal. The sensor apparatus includes: a cover, a lower surface of the cover being provided with an ink layer; a sensor, the sensor being arranged below the cover; at least one light-emitting module, the light-emitting module being arranged as parallel to the sensor; an upper reflecting layer and a lower reflecting layer, the upper reflecting layer being arranged on a lower surface of the ink layer, and the lower reflecting layer being arranged on an upper surface of the sensor; and a light transmitting glue layer, the light transmitting glue layer being arranged between the upper reflecting layer and the lower reflecting layer. The light emitted by the sensor apparatus may form a preset bright shape or pattern via a background color and the opening of the ink layer so as to guide operations of the users in a dark environment, and improve use experience of the users. The sensor apparatus is in a simple structure and in a small volume, and may further implement such biological recognition functions as fingerprint detection, heart rate detection and the like.