Liquid Crystal Lens for Adjustable Depth VR Displays

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Solution Overview

Problem

Current VR and AR devices have large, inflexible designs due to fixed focal length imaging lenses, which limit spatial depth adjustment and complicate mechanical structure design.

Innovation Solution

A display apparatus incorporating a liquid crystal lens with multiple adjustable focal lengths, comprising a first and second transparent electrode layer with a liquid crystal layer in between, and a light guide module to guide light and form virtual images with varying depths of field.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a fixed focal length imaging lens is used, then the device structure is simple, but the spatial depth of imaging is not adjustable and the device size is large

Engineering Contradiction:

Improvespatial depth adjustmentVSAvoiddevice structure

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies a liquid crystal lens whose focal length can be dynamically adjusted by changing voltage. This allows the imaging system to switch between different focal lengths (e.g., 17mm, 28mm, 50mm, 85mm, 135mm, 200mm) without mechanical movement, enabling spatial depth adjustment while maintaining a compact fixed structure.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes the optical parameter (focal length) by adjusting the voltage applied to the liquid crystal lens. By varying the voltage, the refractive index of the liquid crystal changes, which directly alters the focal length of the lens, enabling multi-focal imaging capability in a single device.

Inventive Principle:

Principle #35Parameter changes

2Adaptability or versatility

If multiple lenses with different focal lengths are used, then spatial depth adjustment is enabled, but the device size increases and mechanical structure design becomes difficult

Engineering Contradiction:

Improvespatial depth adjustmentVSAvoiddevice size

Core Design Contradiction:

Adaptability or versatilityVSVolume of moving object

Solution Approach 1:

The patent makes a single imaging lens multi-functional by equipping it with variable focal length capability. The same lens can perform multiple imaging functions (wide-angle, standard, telephoto) by adjusting its focal length through voltage control, eliminating the need for multiple separate lenses and reducing device volume.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent replaces the mechanical lens system (multiple physical lenses or moving lens elements) with an electro-optical system. The focal length adjustment is achieved through electrical voltage control of the liquid crystal material rather than mechanical movement or assembly of multiple lenses, enabling compact device design.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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

Enables the formation of virtual images with multiple spatial depths, facilitating a more compact and flexible device design by allowing adjustable focal lengths and improved imaging capabilities.

Implementation Method 1

a liquid crystal layer between the first transparent electrode layer and the second transparent electrode layer

Methodology Applied

Scientific EffectLiquid crystal refractive index modulation: Liquid Crystals

Implementation Method 2

the first transparent electrode layer is of a plate-like structure, the first electrode sub-layer includes N concentric first annular electrodes, and the second electrode sub-layer includes N concentric second annular electrodes

Methodology Applied

Scientific EffectElectric field effect on liquid crystal: Electric Field

Implementation Method 3

the light guide module is configured to guide light emergent from the liquid crystal lens to propagate in a direction from the light incident region to the light emergent region within the light guide module

Methodology Applied

Scientific EffectLight propagation guidance: Waveguide (optics)

Implementation Method 4

a liquid crystal lens with multiple adjustable focal lengths, arranged between the display module and the light guide module and corresponding to the light incident region of the light guide module and configured to form virtual images with different depths of field

Methodology Applied

Scientific EffectLens focusing: Lens

Implementation Method 5

configured to form virtual images with different depths of field for the images displayed on the display module

Methodology Applied

Scientific EffectVirtual image formation: Focusing

Data Source

PatentUS11231537B2Display apparatus and method for controlling the same

Publication Date: 2022.01.25 BOE TECHNOLOGY GROUP CO LTD

AI summary

A display apparatus and a method for controlling the same are provided. The display apparatus includes: a light guide module comprising a light incident region and a light emergent region; a display module, arranged corresponding to the light incident region of the light guide module and configured to display images; and a liquid crystal lens with a plurality of adjustable focal lengths, arranged between the display module and the light guide module and corresponding to the light incident region of the light guide module, and configured to form virtual images with different depths of field for the images displayed on the display module. The light guide module is configured to guide light exited from the liquid crystal lens to propagate in a direction from the light incident region to the light emergent region within the light guide module.