Photo-sensing pixels adjacent to sub-pixels for biometric sensing

Solution Overview

Problem

Conventional display devices with integrated biometric sensors face challenges in efficiently sensing biometric information due to the placement of photo-sensing pixels on the rear surface of the substrate, leading to reduced sensing ability and increased device thickness.

Innovation Solution

The display device incorporates a design where photo-sensing pixels are positioned adjacent to sub-pixels on the same substrate, with the sub-pixels having polygonal light emitting areas and photo-sensing pixels having quadrilateral light receiving areas, optimizing light incidence and reducing device thickness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If photo-sensing pixels are placed on the rear surface of the substrate, then the sensing function can be implemented, but the sensing ability is reduced and device thickness is increased

Engineering Contradiction:

Improvesensing functionVSAvoidsensing ability

Core Design Contradiction:

ReliabilityVSMeasurement precision

Solution Approach 1:

The patent transitions from placing photo-sensing pixels on the rear surface (one-dimensional placement) to positioning them adjacent to sub-pixels on the same front surface (two-dimensional integration). This dimensional change allows the photo-sensing pixels to be closer to the light source, improving sensing ability while maintaining a thinner device profile.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The patent merges the display function (sub-pixels) and sensing function (photo-sensing pixels) into a single integrated structure on the same substrate. By combining these previously separate components into one unified pixel unit, the patent achieves improved sensing capability without increasing overall device thickness.

Inventive Principle:

Principle #5Merging (Combining)

2Reliability

If photo-sensing pixels are placed on the rear surface of the substrate, then the sensing function can be implemented, but device thickness is increased

Engineering Contradiction:

Improvesensing functionVSAvoiddevice thickness

Core Design Contradiction:

ReliabilityVSLength of stationary object

Solution Approach 1:

The patent merges the display function (sub-pixels) and sensing function (photo-sensing pixels) into a single integrated structure on the same substrate. By combining these previously separate components into one unified pixel unit, the patent achieves improved sensing capability without increasing overall device thickness.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent transitions from placing photo-sensing pixels on the rear surface (one-dimensional placement) to positioning them adjacent to sub-pixels on the same front surface (two-dimensional integration). This dimensional change allows the photo-sensing pixels to be closer to the light source, improving sensing ability while maintaining a thinner device profile.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

3Loss of energy

If light emitting area and light receiving area are spaced apart, then light loss is reduced, but sensing accuracy is compromised

Engineering Contradiction:

Improvelight lossVSAvoidsensing accuracy

Core Design Contradiction:

Loss of energyVSMeasurement precision

Solution Approach 1:

The patent applies different geometric characteristics to different parts of the pixel structure: the light emitting area uses a polygonal shape (e.g., hexagon) optimized for light emission and extraction, while the light receiving area uses a quadrilateral shape optimized for light detection. This local optimization allows each area to perform its function efficiently while maintaining appropriate spacing to reduce light loss.

Inventive Principle:

Principle #3Local quality

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 the sensing capability and recognition rate of biometric information while minimizing device thickness and light loss, improving both light efficiency and sensing accuracy.

Implementation Method 1

each of the sub-pixels includes a light emitting element and a light emitting area from which light is emitted

Methodology Applied

Scientific EffectLight emission: Light Emitting Diode

Implementation Method 2

each of the photo-sensing pixels includes a light receiving area and a light receiving element disposed therein and outputting a sensing signal corresponding to a degree of sensed light

Methodology Applied

Scientific EffectLight sensing: Photoelectric Effect

Data Source

PatentUS20230329020A1Display device including photo-sensing pixels

Publication Date: 2023.10.12 SAMSUNG DISPLAY CO LTD

AI summary

A display device includes a substrate; and a plurality of unit pixels disposed on the substrate and including sub-pixels and photo-sensing pixels. Each of the sub-pixels includes a light emitting element and a light emitting area from which light is emitted. Each of the photo-sensing pixels includes a light receiving area and a light receiving element disposed therein and outputting a sensing signal corresponding to a degree of sensed light. The light emitting area and the light receiving area are spaced apart from each other on the substrate. The light emitting area and the light receiving area each have a polygonal shape. Aa shape of the light emitting area is different from a shape of the light receiving area.