Light-Shielding Layer for Optical Fingerprint Recognition Accuracy

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Solution Overview

Problem

Existing display apparatuses using optical fingerprint recognition technology face accuracy issues due to stray light entering the fingerprint recognition unit, which does not reflect fingerprint information, interfering with the recognition process.

Innovation Solution

A display module with a light-shielding layer positioned on the side of the photosensitive semiconductor layer close to the underlay substrate, ensuring its projection completely covers the semiconductor layer, and a length at least twice that of the sub-pixels, effectively blocking stray light from entering the fingerprint recognition unit.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a light source is used for fingerprint recognition, then fingerprint recognition function is enabled, but stray light enters the fingerprint recognition unit affecting accuracy

Engineering Contradiction:

Improvefingerprint recognition functionVSAvoidfingerprint recognition accuracy

Core Design Contradiction:

Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

A light-shielding layer is introduced as an intermediary component between the light source and the fingerprint recognition unit. This layer selectively blocks stray light while allowing reflected light containing fingerprint information to pass through, thereby resolving the contradiction between enabling fingerprint recognition and maintaining recognition accuracy.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The light-shielding layer is positioned specifically at locations where stray light would interfere with the fingerprint recognition unit, rather than uniformly shielding the entire display. This localized approach maintains the versatility of the display while improving recognition accuracy by blocking only the harmful stray light paths.

Inventive Principle:

Principle #3Local quality

2Measurement precision

If the light-shielding layer completely covers the photosensitive semiconductor layer, then stray light is effectively blocked, but the structure becomes more complex

Engineering Contradiction:

Improvefingerprint recognition accuracyVSAvoidstructure complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The light-shielding layer is integrated with existing display structures, such as being formed on the same substrate as other display components or combining multiple functions into a single layer. This merging approach blocks stray light effectively while minimizing the increase in overall structural complexity.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The light-shielding layer is divided into multiple segments or regions, each covering specific areas of the photosensitive semiconductor layer where stray light interference occurs. This segmentation allows for effective stray light blocking while simplifying the manufacturing process and reducing overall structural complexity compared to a single large shielding layer.

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 configuration significantly improves the accuracy of fingerprint recognition by preventing interference from stray light, ensuring only reflected light with fingerprint information is processed, thereby enhancing recognition accuracy.

Implementation Method 1

The first light-shielding layer is located on a side of the photosensitive semiconductor layer close to the underlay substrate... a length of the first light-shielding layer along the first direction is larger than or equal to twice a length of each of the plurality of sub-pixels along the first direction

Methodology Applied

Scientific EffectLight shielding: Absorption (EM radiation)

Data Source

PatentUS11594063B2Display module including light-shielding layer, and display apparatus

Publication Date: 2023.02.28 XIAMEN TIANMA MICRO ELECTRONICS

AI summary

Provided are a display module and a display apparatus. The display module includes: sub-pixels arranged in an array along a first direction and a second direction; and an array substrate including an underlay substrate, a fingerprint recognition unit, and a first light-shielding layer. The fingerprint recognition unit includes a photosensitive semiconductor layer, and an orthographic projection of the photosensitive semiconductor layer on a plane of the underlay substrate is located between two adjacent sub-pixels along the second direction. The first light-shielding layer is located on a side of the photosensitive semiconductor layer close to the underlay substrate, and an orthographic projection of the first light-shielding layer on a plane of the photosensitive semiconductor layer completely covers the photosensitive semiconductor layer, and along the first direction, a length of the first light-shielding layer is larger than or equal to twice a length of each of the plurality of sub-pixels.