Fingerprint Sensor with Integrated LED Feedback Surface

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Solution Overview

Problem

Current fingerprint recording devices face challenges in providing intuitive feedback for correct finger positioning and contact pressure, leading to increased user effort and potential errors due to separate display units and complex mechanical components.

Innovation Solution

A device with light-emitting elements arranged in a second pixel grid, capable of emitting light in a transparent frequency range, providing visual and haptic feedback directly on the contact surface, allowing for real-time correction of finger placement and pressure, integrated with a spectral filter and light-sensitive sensor elements for accurate image capture.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a prism is used for optical fingerprint recording, then image quality meets high standards, but device size and mass increase

Engineering Contradiction:
Improveimage qualityVSAvoiddevice mass
Core Design Contradiction:
Measurement precisionVSWeight of stationary object

Solution Approach 1:

The patent removes the prism from the optical system entirely, replacing it with a flat contact surface and direct LED illumination. This extraction of the bulky optical component achieves miniaturization while maintaining fingerprint recording capability through alternative optical principles.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the mechanical/optical prism system with a simplified planar structure using LEDs and a flat sensor surface. This substitution eliminates complex mechanical components while achieving the same fingerprint detection function through direct optical contact.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Measurement precision

If a prism is used for optical fingerprint recording, then image quality meets high standards, but device complexity increases

Engineering Contradiction:
Improveimage qualityVSAvoidcomponent complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts and removes the complex prism assembly and associated mechanical adjustment mechanisms, replacing them with a simple flat contact surface and fixed LED array, thereby dramatically reducing device complexity.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent merges the illumination function and sensor function into a single integrated planar structure, eliminating the need for separate optical paths and alignment mechanisms that would increase complexity.

Inventive Principle:
Principle #5Merging (Combining)

3Ease of operation

If display information is shown on a separate screen, then user guidance is provided, but user effort and recording time increase

Engineering Contradiction:
Improveuser guidanceVSAvoidrecording time
Core Design Contradiction:
Ease of operationVSLoss of time

Solution Approach 1:

The patent combines the display function with the fingerprint sensor surface itself, using the same contact surface to both capture fingerprints and provide visual feedback through LEDs, eliminating the need for separate display screens and reducing user effort.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent uses LEDs integrated into the sensor surface as an intermediary that provides visual guidance directly at the point of contact, eliminating the need for users to shift their gaze between separate display screens and the fingerprint surface.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Measurement precision

If a prism is used for optical fingerprint recording, then image quality meets high standards, but assembly and adjustment time increases

Engineering Contradiction:
Improveimage qualityVSAvoidassembly time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent removes the prism and its associated complex assembly and adjustment mechanisms, replacing them with a simple planar structure that requires minimal assembly and no complex optical alignment, thereby reducing assembly time.

Inventive Principle:
Principle #2Taking out (Extraction)

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

Enhances user experience by reducing recording time and errors through intuitive feedback, improving the accuracy of fingerprint capture while maintaining a compact and user-friendly design.

Implementation Method 1

A plurality of light-emitting elements are arranged next to one another in a second pixel grid, are designed to emit light in a frequency range for which the layered body is at least partially transparent, so that the light can be coupled through the contact surface in the direction of a skin area

Methodology Applied
Scientific EffectLight emission and transmission: Light

Implementation Method 2

a layered body with a sensor layer in which light-sensitive sensor elements with predetermined lateral dimensions are arranged in a first pixel grid

Methodology Applied
Scientific EffectPhotoelectric detection: Photoelectric Effect

Implementation Method 3

a spectral filter, for example a long-pass filter, whose limit wavelength is predetermined as a function of the optical absorption behavior of the blood-perfused skin areas

Methodology Applied
Scientific EffectSpectral filtering: Filter (optical)

Data Source

PatentEP3142043B1Device and method for optical recording of areas of skin with blood flowing through
Publication Date: 2023.03.22 JENETRIC GMBH
  • EP3142043B1 patent drawingFigure 1a~1b
  • EP3142043B1 patent drawingFigure 2
  • EP3142043B1 patent drawingFigure 3~5

AI summary

The invention relates to a device and a method for taking impressions of vascularized skin areas of human autopodia or parts thereof. Such a device, suitable for carrying out the method, comprises, viewed from the direction of a skin area to be placed on it, a contact surface (3) for supporting at least one skin area, a layered body containing a sensor layer (6) with light-sensitive sensor elements (7) of predetermined lateral dimensions arranged in a first pixel grid, and light-emitting elements (8, 13). The light-emitting elements (8, 13) are arranged side by side in a grid pattern in a second pixel grid. They emit light in a frequency range for which the layered body, and in particular the sensor layer (6) contained in the layered body, is at least partially transparent, so that light emitted from the contact surface (3) in the direction of a skin area can be coupled into it.The light-emitting elements (8, 13) can also be controlled individually or in groups and thus switched on and off, so that, depending on intensity values ​​determined by the light-sensitive sensor elements (7), these light-emitting elements (8, 13) can be controlled to display visual information, which is shown on the surface (3). The distance of each light-sensitive element (7) to the surface (3) is less than the pixel pitch of the first pixel grid.