Fingerprint Sensor Opening Step Design for Display Visibility

Solution Overview

Problem

The integration of a fingerprint sensing unit into electronic devices often results in a visible rear surface phenomenon, which compromises outdoor visibility and display characteristics, especially when the fingerprint sensor is positioned on the rear surface of a display panel.

Innovation Solution

The electronic device incorporates a cover panel with a defined opening part that accommodates a fingerprint sensor, an adhesive member, and a lower panel, where the opening part has a step and different sizes for the first and second openings, minimizing interference and light leakage, and includes a light-absorbing rear surface cover layer to reduce visible phenomena.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a fingerprint sensor is disposed on the rear surface of a display panel, then fingerprint sensing function is achieved, but rear surface visibility and display characteristics are compromised

Engineering Contradiction:

Improvefingerprint sensing functionVSAvoidoutdoor visibility

Core Design Contradiction:

Adaptability or versatilityVSIllumination intensity

Solution Approach 1:

The opening part is divided into a first opening part and a second opening part with different planar sizes, creating a stepped structure that segments the light path and reduces rear surface visibility while maintaining fingerprint sensing function

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The invention introduces a depth dimension by creating a stepped structure with different opening sizes at different levels, transforming a two-dimensional opening into a three-dimensional stepped configuration that blocks rear surface visibility

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Adaptability or versatility

If a fingerprint sensor is disposed on the rear surface of a display panel, then fingerprint sensing function is achieved, but display characteristics are compromised

Engineering Contradiction:

Improvefingerprint sensing functionVSAvoiddisplay characteristics

Core Design Contradiction:

Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The opening part is divided into a first opening part and a second opening part with different planar sizes, creating a stepped structure that segments the light path and reduces rear surface visibility while maintaining fingerprint sensing function

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The adhesive member is selectively disposed in specific regions (first region and second region) with different configurations, providing localized adhesion and optical control to maintain display characteristics while enabling fingerprint sensing

Inventive Principle:

Principle #3Local quality

3Illumination intensity

If the opening part has a step with different sizes for first and second openings, then rear surface visibility is reduced, but device complexity increases

Engineering Contradiction:

Improverear surface visibilityVSAvoidcover panel structure

Core Design Contradiction:

Illumination intensityVSDevice complexity

Solution Approach 1:

The opening part is divided into a first opening part and a second opening part with different planar sizes, creating a stepped structure that segments the light path and reduces rear surface visibility while maintaining fingerprint sensing function

Inventive Principle:

Principle #1Segmentation

Data Source

PatentUS11508175B2Electronic device

Publication Date: 2022.11.22 SAMSUNG DISPLAY CO LTD

AI summary

An electronic device includes a display panel including a base substrate and a plurality of pixels disposed on a front surface of the base substrate to display an image, a cover panel in which an opening part is defined, a fingerprint sensor spaced by a predetermined gap from the cover panel and accommodated in the opening part, and an adhesive member accommodated in the opening part and disposed between the fingerprint sensor and the display panel, and the opening part includes a side surface having a step.