Head-Up Display Virtual Image Projection Distance Adjustment

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Solution Overview

Problem

Existing head-up display devices face challenges in rapidly varying the projection distance of virtual images, which limits their ability to adapt to changing vehicle speeds and driver eye positions, resulting in reduced visibility and increased eye movement.

Innovation Solution

A head-up display device incorporating a display, a beam splitter, a movable mirror, and an adjuster that adjusts the distance between the movable mirror and the beam splitter to change the projection distance of the virtual image, allowing for high-speed adjustment of the image's position relative to the driver's viewpoint.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If the projection distance is varied using conventional methods, then the virtual image position can be adjusted, but the adjustment speed is slow and cannot adapt rapidly to changing vehicle speeds and driver eye positions

Engineering Contradiction:
Improveadjustment speed of virtual image projection distanceVSAvoidadaptability to changing vehicle speeds and driver eye positions
Core Design Contradiction:
SpeedVSAdaptability or versatility

Solution Approach 1:

The patent applies the dynamics principle by making the optical system adjustable and adaptable to changing conditions. Specifically, the optical system includes adjustable optical elements that can dynamically change the projection distance of the virtual image to adapt to varying vehicle speeds and driver eye positions, transforming a static system into a dynamic one that responds to real-time requirements.

Inventive Principle:
Principle #15Dynamics

2Adaptability or versatility

If the projection distance is adjusted to maintain visibility at different speeds, then adaptability improves, but device complexity increases

Engineering Contradiction:
Improveadaptability to different driving conditionsVSAvoidcomplexity of optical adjustment mechanism
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies the universality principle by designing an optical system that performs multiple functions through integrated components. The optical elements serve both to form the virtual image and to adjust its projection distance, eliminating the need for separate adjustment mechanisms and reducing overall system complexity while maintaining adaptability to different driving conditions.

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

3Reliability

If the image position is maintained relative to the driver's eye at different speeds, then visibility improves, but the size and weight of the display device increase

Engineering Contradiction:
Improvevisibility of virtual imageVSAvoidweight of head-up display device
Core Design Contradiction:
ReliabilityVSWeight of moving object

Solution Approach 1:

The patent applies the flexible shells and thin films principle by using thin-film optical elements that can dynamically adjust their properties to maintain virtual image visibility at different speeds. These thin-film components provide the necessary optical functionality with minimal added weight, ensuring reliability of image visibility without significantly increasing the overall device weight.

Inventive Principle:
Principle #30Flexible shells and thin films

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 rapid variation of the virtual image projection distance, improving visibility by maintaining the image's position relative to the driver's eye at different speeds and reducing eye movement, while also reducing the size and weight of the display device.

Implementation Method 1

a light separator which is an optical member that reflects light or through which light is transmitted, and that reflects light emitted from the display

Methodology Applied
Scientific EffectReflection: Reflection

Implementation Method 2

a first optical member that reflects light reflected off the light separator

Methodology Applied
Scientific EffectReflection: Reflection

Implementation Method 3

one or more second optical members that reflect light transmitted through the light separator after being reflected off the first optical member, or through which the light transmitted through the light separator is transmitted, to project a virtual image

Methodology Applied
Scientific EffectReflection: Reflection

Data Source

PatentEP3264159B1Headup display device and vehicle
Publication Date: 2020.03.25 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD
  • EP3264159B1 patent drawingFigure 1
  • EP3264159B1 patent drawingFigure 2
  • EP3264159B1 patent drawingFigure 3

AI summary

A head-up display device 1 includes a display element 110, a beam splitter 120, a movable mirror 130, first and second mirrors 150, 160, and a movable unit 140. The display element 110 emits light to form a display image. The beam splitter 120 being an optical member that reflects light or through which light is transmitted, reflects light emitted from the display element 110. The movable mirror 130 reflects light reflected off the beam splitter 120. The first and second mirrors 150, 160 that reflect light transmitted through the beam splitter 120 after being reflected off the movable mirror 130, or through which the light transmitted through the beam splitter 120 is transmitted, project a virtual image. The movable unit 140 adjusts a distance between the movable mirror 130 and the beam splitter 120 to adjust a projection distance of the virtual image.