Under-Display Optical Sensor Layout for Full-Screen Proximity Sensing

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Solution Overview

Problem

The integration of proximity and ambient-light sensors in electronic devices requires a large hole in the cover plate, compromising the screen-to-body ratio and aesthetics, especially in devices with full-screen displays and ultra-narrow bezels, which reduces reliability and space utilization.

Innovation Solution

An optical sensor design featuring a base plate with an emitter coupled to it and a receiver surrounding the emitter, positioned below a light-permeable display screen, allowing for infrared and visible light communication without the need for a hole in the bezel, thus enhancing space utilization and reliability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a large hole is provided in the cover plate for sensor integration, then sensor reliability is improved, but screen-to-body ratio deteriorates and aesthetics worsen

Engineering Contradiction:
Improvesensor reliabilityVSAvoidscreen-to-body ratio
Core Design Contradiction:
ReliabilityVSArea of stationary object

Solution Approach 1:

The patent transitions from a planar sensor arrangement requiring a hole in the cover plate to a three-dimensional arrangement where the receiver is positioned below the display screen. This vertical dimensionality change allows the optical sensor to function without compromising the front surface area, thereby maintaining screen-to-body ratio while ensuring sensor reliability through proper optical path configuration.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The optical sensor components are nested within the display structure, with the receiver positioned below the display screen and the emitter arranged to communicate through the light-permeable display. This nesting approach integrates the sensor system within the existing device architecture without requiring additional holes or external openings.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Reliability

If a large hole is provided in the cover plate for sensor integration, then sensor reliability is improved, but aesthetics deteriorate

Engineering Contradiction:
Improvesensor reliabilityVSAvoidaesthetics
Core Design Contradiction:
ReliabilityVSShape

Solution Approach 1:

By moving the receiver to a position below the display screen and utilizing the vertical space, the invention eliminates the need for visible holes in the front cover plate. This dimensional repositioning preserves the aesthetic appearance of the device front surface while maintaining sensor functionality through the light-permeable display medium.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Volume of stationary object

If the emitter and receiver are positioned to communicate through the display screen, then space utilization is improved, but manufacturing complexity increases

Engineering Contradiction:
Improvespace utilizationVSAvoidmanufacturing complexity
Core Design Contradiction:
Volume of stationary objectVSEase of manufacture

Solution Approach 1:

The patent divides the optical sensor system into distinct functional modules: the emitter positioned above the display screen and the receiver positioned below it. This segmentation allows each component to be manufactured and tested independently before assembly, reducing overall manufacturing complexity despite the three-dimensional configuration. The base plate structure further segments the receiver assembly for easier integration.

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 design enables accurate distance detection and ambient light sensing without compromising the screen-to-body ratio or aesthetics, improving user experience and battery life by preventing misoperations and optimizing internal space.

Implementation Method 1

an emitter arranged on the base plate and facing the second surface of the light-permeable display screen. The emitter is configured to emit an infrared light through the light-permeable display screen

Methodology Applied
Scientific EffectInfrared radiation: Infrared Radiation

Implementation Method 2

a receiver surrounding the emitter and configured to communicate with the emitter... The receiver is configured to receive the infrared light

Methodology Applied
Scientific EffectReflection: Reflection

Implementation Method 3

positioned below a light-permeable display screen, allowing for infrared and visible light communication without the need for a hole in the bezel

Methodology Applied
Scientific EffectLight transmission: Light

Data Source

PatentEP3537171B1Optical sensor and electronic device
Publication Date: 2023.08.23 GUANGDONG OPPO MOBILE TELECOMMUNICATIONS CORP LTD

AI summary

An optical sensor and an electronic device are provided. The electronic device 100 includes a light-permeable display screen 13, an optical sensor 16, and a housing 20. The light-permeable display screen 13 has a first surface 131 and a second surface 132, and the first surface 131 faces away from the second surface 132. The optical sensor 16 is arranged opposite to the second surface 132 of the light-permeable display screen 13. The optical sensor 16 includes a base plate 1614, an emitter 1611 arranged on the base plate 1614 and a receiver 1612 surrounding the emitter 1611. The emitter 1611 faces the second surface 132 of the light-permeable display screen 13 and is configured to emit an infrared light through the light-permeable display screen 13. The receiver 1612 is configured to receive the infrared light. When the infrared light emitted by the emitter 1611 encounters an obstacle in a detection direction, a part of the infrared light will be reflected back, passes through the light-permeable display screen 13 and finally is received by the receiver 1612, and thus a distance from the electronic device 100 to the obstacle can be determined by a processor calculating a time of the infrared light from being emitted to being reflected back, such that a corresponding adjustment can be made. For example, when the electronic device 100 is moved towards the user's head, the emitter 1611 emits the infrared light, and the receiver 1612 receives the infrared light reflected back from the head. After the processor calculates the time of the infrared light from being emitted to being reflected, an instruction is generated to turn off the display screen's backlight. The receiver 1612 has functions of receiving both the infrared light and the visible light, such that a reserved position for disposing a ambient-light receiver is saved. In conclusion, the optical sensor 16 can be arranged below the light-permeable display screen 13 with the full-screen display. Moreover, the receiver surrounds the emitter to further reduce the occupied portion of the electronic device 100, thus improving the space utilization of the electronic device 100. Preferably, the optical sensor 16 includes a proximity sensor and an ambient-light sensor, and the ambient-light receiver is integrated with the proximity receiver. The electronic device 100 further includes a light-permeable touch panel 12 and a light-permeable cover plate 11.