Display Window Optical Layer for Biometric Sensing

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Solution Overview

Problem

Existing display devices face challenges in achieving both improved biometric data recognition and high light receiving efficiency, particularly in effectively guiding and managing light for biometric sensing while minimizing visible light emission.

Innovation Solution

The display device incorporates a window with a specific geometric configuration, including inclined surfaces and layers, an optical layer with a lower refractive index than the window, and light-blocking layers that transmit infrared light and reflect visible light, allowing for total internal reflection and enhanced light guidance within the window to improve biometric data recognition sensitivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a conventional window structure is used, then the device structure is simple, but light receiving efficiency and biometric data recognition sensitivity are insufficient

Engineering Contradiction:

Improvebiometric data recognition sensitivityVSAvoidwindow structure complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The window is divided into multiple functional regions including a transmission region, a light-blocking region, and an inclined region. This segmentation allows each region to perform its specific function optimally, improving biometric data recognition sensitivity while maintaining reasonable structural complexity through functional zoning.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the window are assigned different optical properties: the transmission region allows light passage for sensing, the light-blocking region blocks visible light to prevent emission, and the inclined region guides light through total internal reflection. This local differentiation of properties enhances overall performance without requiring complete restructuring of the entire window.

Inventive Principle:

Principle #3Local quality

2Object-generated harmful factors

If light-blocking layers are added to prevent visible light emission, then visible light emission is reduced, but device complexity increases

Engineering Contradiction:

Improvevisible light emissionVSAvoidlayer structure complexity

Core Design Contradiction:

Object-generated harmful factorsVSDevice complexity

Solution Approach 1:

The light-blocking layer is integrated with the window structure itself, combining the functions of structural support and light blocking in a single component. This merging approach reduces the need for separate structural elements while achieving effective visible light emission prevention.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The window structure serves multiple functions simultaneously: it provides structural support, guides light through total internal reflection, blocks visible light emission, and enables biometric sensing. This multi-functionality reduces the need for additional separate components, thereby limiting the increase in device complexity.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Loss of energy

If an optical layer with lower refractive index is introduced, then total internal reflection and light guidance are enhanced, but device complexity increases

Engineering Contradiction:

Improvelight guidance efficiencyVSAvoidoptical layer structure

Core Design Contradiction:

Loss of energyVSDevice complexity

Solution Approach 1:

The optical layer is designed with a specific refractive index lower than that of the window material. This parameter change enables total internal reflection at the window-optical layer interface, significantly enhancing light guidance efficiency. The refractive index parameter is carefully selected to optimize the balance between light guidance and structural simplicity.

Inventive Principle:

Principle #35Parameter changes

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 enhances light receiving efficiency and biometric data recognition sensitivity by ensuring infrared light is effectively used for sensing while preventing visible light from being emitted, thus improving the overall performance of the display device.

Implementation Method 1

allowing for total internal reflection and enhanced light guidance within the window

Methodology Applied

Scientific EffectTotal internal reflection: Total Internal Reflection

Implementation Method 2

light-blocking layers that transmit infrared light and reflect visible light

Methodology Applied

Scientific EffectSelective transmission and reflection of electromagnetic radiation: Filter (optical)

Data Source

PatentUS20230337509A1Display device

Publication Date: 2023.10.19 SAMSUNG DISPLAY CO LTD

AI summary

A display device may include a window including a top surface, a bottom portion facing the top surface, and a side portion connecting the top surface to the bottom portion and the window including a transmission region and a light-blocking region, a light-blocking layer disposed below the window and overlapping the light-blocking region in a plan view, a light source spaced apart from the bottom portion in a direction in a plan view, and a display panel disposed below the window. The display panel may include a light sensing device, and may include a display region overlapping the transmission region.