Head-Up Display Using Polarization Control for Distance Projection

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Solution Overview

Problem

Existing head-up display systems are complex, require a large number of mirrors, and have high energy consumption, limiting their efficiency and practicality for automotive applications.

Innovation Solution

A display apparatus that includes a display unit and an image processing unit capable of changing polarization direction and selectively scattering or transmitting light to project images at different distances, utilizing a first polarization conversion element, a birefringent lens, a liquid crystal dispersing element, and a control unit to simplify the structure and reduce energy consumption, eliminating the need for multiple mirrors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If traditional head-up display systems use multiple mirrors to project images at different distances, then multiple virtual images can be displayed simultaneously, but the device complexity and energy consumption increase significantly

Engineering Contradiction:
Improvedisplay distance flexibilityVSAvoidnumber of mirrors
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent changes the optical parameters of a single beam splitter by adjusting its tilt angle to control the projection distance of virtual images. By tilting the beam splitter at different angles, the system can display virtual images at different distances without requiring multiple mirrors, thus resolving the contradiction between display adaptability and device complexity

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The beam splitter is designed to perform multiple functions: it acts as both a beam splitting element and a distance control element. By adjusting the beam splitter's tilt angle, the same component can project virtual images at various distances, eliminating the need for separate mirrors for each distance, thereby reducing device complexity while maintaining versatility

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Adaptability or versatility

If traditional head-up display systems use multiple mirrors for different projection distances, then multiple virtual images can be displayed, but energy consumption increases

Engineering Contradiction:
Improveprojection distance controlVSAvoidenergy consumption
Core Design Contradiction:
Adaptability or versatilityVSUse of energy by stationary object

Solution Approach 1:

The system controls projection distance by changing the tilt angle parameter of the beam splitter rather than using multiple energy-consuming mirror assemblies. This parameter adjustment approach reduces energy consumption while maintaining the ability to display virtual images at different distances

Inventive Principle:
Principle #35Parameter changes

3Device complexity

If a single beam splitter is used with tilt angle adjustment, then device complexity is reduced, but the ability to display multiple virtual images simultaneously may be limited

Engineering Contradiction:
Improvebeam splitter configurationVSAvoidmultiple virtual image display
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The beam splitter is designed with dynamic tilt angle adjustment capability, allowing it to change its orientation during operation. This dynamic adjustment enables a single beam splitter to perform the work of multiple static mirrors, maintaining the ability to display multiple virtual images at different distances while reducing device complexity

Inventive Principle:
Principle #15Dynamics

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

The solution simplifies the structure, reduces energy consumption, and allows for flexible display modes, enabling images to be projected at different distances without overlapping, enhancing user experience and safety by reducing the complexity and power requirements of head-up displays.

Implementation Method 1

a first polarization conversion element configured to change a polarization direction of light for the display image into a first polarization direction or a second polarization direction

Methodology Applied
Scientific EffectPolarization conversion: Polarisation

Implementation Method 2

a birefringent lens configured to deflect the light of the first polarization direction and not to change direction of the light of the second polarization direction

Methodology Applied
Scientific EffectBirefringence: Birefringence

Implementation Method 3

a liquid crystal dispersing element configured to scatter the light of the first polarization direction and transmit the light of the second polarization direction

Methodology Applied
Scientific EffectLiquid crystal scattering: Liquid Crystals

Implementation Method 4

a beam splitter configured to receive the light of the first polarization direction transmitted by the liquid crystal dispersing element or the light of the second polarization direction transmitted by the liquid crystal dispersing element, and to cause an exit direction of the light of the first polarization direction to be different from an exit direction of the light of the second polarization direction

Methodology Applied
Scientific EffectPolarization-dependent beam splitting: Polarisation

Data Source

PatentEP3746836B1Display apparatus, display method thereof, and head-up display apparatus
Publication Date: 2024.02.21 BOE TECHNOLOGY GROUP CO LTD
  • EP3746836B1 patent drawingFigure 1
  • EP3746836B1 patent drawingFigure 2
  • EP3746836B1 patent drawingFigure 3A

AI summary

A display apparatus includes a display unit (2) and an image processing unit (3). The display unit may be configured to project light for a display image. The image processing unit may be configured to change polarization direction of the light for the display image and to selectively scatter or transmit the light for the display image based on the polarization direction of the light for the display image.