Overlaid Waveguide for Display Sensor Integration

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Solution Overview

Problem

Wearable and portable consumer devices face space constraints due to the integration of optical displays and sensor modules for radiation, leading to increased device size and thickness, as traditional sensing systems compete for space with the display.

Innovation Solution

A planar optical waveguide is overlaid on the display to guide optical radiation in a second wavelength band across the display surface, using diffractive structures to couple radiation between the waveguide and a functional module located outside the display area, allowing for emission and detection of radiation without interfering with the display functionality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If traditional sensor modules are integrated into wearable devices, then sensing functions (illumination, ambient light sensing, gesture recognition) are enabled, but device size and thickness increase due to space constraints

Engineering Contradiction:

Improvesensing functionsVSAvoiddevice size

Core Design Contradiction:

Adaptability or versatilityVSVolume of moving object

Solution Approach 1:

The patent merges the display and sensor modules into a single integrated structure where the waveguide is overlaid on the display. The same optical waveguide that displays images also guides sensor radiation, allowing multiple functions (display and sensing) to share the same physical space without increasing device volume.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent uses different wavelength bands (dimensions) to separate display and sensor functions. The display operates in the visible wavelength band while sensors operate in infrared or ultraviolet bands, allowing both functions to coexist in the same physical space by utilizing different spectral dimensions.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Adaptability or versatility

If sensor modules are added to the device, then additional functionality is provided, but the device thickness increases

Engineering Contradiction:

Improveadditional functionalityVSAvoiddevice thickness

Core Design Contradiction:

Adaptability or versatilityVSLength of stationary object

Solution Approach 1:

The sensor module is nested within the display structure by overlaying the waveguide on the display. The waveguide acts as a common platform that contains both display functionality and sensor functionality, with sensors positioned at edges or within the waveguide structure, effectively nesting one function within another without increasing overall thickness.

Inventive Principle:

Principle #7Nested doll (Nesting)

3Adaptability or versatility

If the waveguide guides infrared or ultraviolet radiation, then sensor functions are enabled, but interference with visible light display may occur

Engineering Contradiction:

Improvesensor radiation guidanceVSAvoiddisplay interference

Core Design Contradiction:

Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The waveguide is designed with different optical properties for different wavelength bands. It is transparent to visible light wavelengths to allow display functionality while being opaque or guiding to infrared and ultraviolet wavelengths for sensor functions. The diffractive structures are engineered to be spectrally selective, affecting only specific wavelength bands.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent exploits the concept of wavelength-dependent optical properties (analogous to color changes). The waveguide and diffractive structures are designed to interact differently with different wavelength bands - transparent to visible light while guiding infrared/ultraviolet radiation, effectively using spectral separation to avoid interference.

Inventive Principle:

Principle #32Color 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 solution enables the performance of functions like illumination, ambient light sensing, and gesture recognition without increasing the device size, as the waveguide operates transparently to visible light and guides infrared or ultraviolet radiation, minimizing interference with the display.

Implementation Method 1

One or more diffractive structures are formed in the planar optical waveguide so as to couple the guided second optical radiation between the planar optical waveguide and a region in front of or behind the display

Methodology Applied

Scientific EffectDiffraction: Diffraction

Implementation Method 2

A planar optical waveguide, which is transparent in the first wavelength band, is overlaid on the display and is configured to guide second optical radiation in a second wavelength band along a direction transverse to the front surface

Methodology Applied

Scientific EffectTotal internal reflection: Total Internal Reflection

Data Source

PatentUS11754767B1Display with overlaid waveguide

Publication Date: 2023.09.12 APPLE INC

AI summary

An optoelectronic device includes a display configured to emit first optical radiation in a first wavelength band through a front surface of the display. A planar optical waveguide, which is transparent in the first wavelength band, is overlaid on the display and is configured to guide second optical radiation in a second wavelength band along a direction transverse to the front surface. One or more diffractive structures are formed in the planar optical waveguide so as to couple the guided second optical radiation between the planar optical waveguide and a region in front of or behind the display.