Collimator-Based Fingerprint Sensing in Display Devices

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Solution Overview

Problem

Current display devices for fingerprint identification have a limited user interface area, leading to a poor user experience due to the small region available for fingerprint input, which restricts the effectiveness and convenience of fingerprint recognition.

Innovation Solution

A display device with a photosensitive layer and collimators that allow light signals to pass through light-passing holes, enabling the acquisition of images for fingerprint identification over a larger area of the display face, thereby enhancing user experience by allowing fingerprint input across a greater proportion of the display region.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If the fingerprint identification module is stacked below the display module with a small touch area, then the device structure is compact, but the user experience deteriorates due to limited fingerprint input area

Engineering Contradiction:
Improvefingerprint input areaVSAvoiddisplay structure complexity
Core Design Contradiction:
Area of stationary objectVSDevice complexity

Solution Approach 1:

The display module serves dual functions: it acts as both the display screen and the fingerprint sensing area. The entire display region can be used for fingerprint identification, eliminating the need for a separate dedicated fingerprint module and expanding the usable area while maintaining structural simplicity

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

Solution Approach 2:

The fingerprint sensing function is merged with the display module by placing photosensitive units behind the display face, allowing the display structure itself to perform both display and biometric authentication functions simultaneously

Inventive Principle:
Principle #5Merging (Combining)

2Reliability

If light signals are allowed to pass through the display face for fingerprint recognition, then fingerprint identification capability is improved, but display quality may deteriorate due to light interference

Engineering Contradiction:
Improvefingerprint recognition accuracyVSAvoiddisplay brightness uniformity
Core Design Contradiction:
ReliabilityVSIllumination intensity

Solution Approach 1:

The light-shielding member is positioned at specific locations (between adjacent display units) rather than covering the entire display face, allowing light to pass through the display face for fingerprint sensing while blocking light only where necessary to prevent interference between adjacent pixels

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The light-shielding member divides the display face into separate light-shielding areas and light-transmitting areas, with light-passing holes positioned precisely to align with photosensitive units while maintaining display quality in other regions

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

This solution allows for improved fingerprint identification by expanding the input area, enriching verification methods and scenarios, and providing a better user experience by enabling fingerprint recognition across a larger display area.

Implementation Method 1

the collimators defining light-passing holes aligned with the photosensitive units, wherein the light-passing holes are capable of allowing light signals to pass through to reach the photosensitive units

Methodology Applied
Scientific EffectLight transmission: Light

Implementation Method 2

a photosensitive layer including a plurality of photosensitive units... receiving imaging light signals including a target light signal, wherein the target light signal sequentially passes through the display face, the light-passing holes, and reaches the photosensitive layer

Methodology Applied
Scientific EffectPhotoelectric detection: Photoelectric Effect

Implementation Method 3

The substrate includes a plurality of display units and a light-shielding member, the light-shielding member is disposed to space apart every two adjacent ones of the plurality of display units

Methodology Applied
Scientific EffectLight shielding: Absorption (EM radiation)

Data Source

PatentEP3757666B1Display device, electronic apparatus, and image acquisition method
Publication Date: 2023.01.18 GUANGDONG OPPO MOBILE TELECOMMUNICATIONS CORP LTD
  • EP3757666B1 patent drawingFigure 1~2
  • EP3757666B1 patent drawingFigure 3~4
  • EP3757666B1 patent drawingFigure 5~6

AI summary

The present disclosure provides a display device (100) including a display face (91) and a bottom face (11) facing away from each other. Between the display face (91) and the bottom face (11), the display device (100) further includes: a substrate (60); a photosensitive layer (40) including a plurality of photosensitive units (41), the plurality of photosensitive units being disposed on the substrate (60); and a plurality of collimators (71) disposed between the photosensitive layer (40) and the display face (91), the collimators defining light-passing holes (711) aligned with the photosensitive units. The light-passing holes are capable of allowing light signals to pass through to reach the photosensitive units. The present disclosure further provides an image acquisition method.