Head-Up Display Laser Optical System for Driver Visibility

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Solution Overview

Problem

Existing head-up display (HUD) systems in vehicles often cause image overlap with objects at or near the same position as the displayed image, reducing driver visibility and increasing eye strain due to the short focal distance of the virtual image.

Innovation Solution

The HUD system is designed to display virtual images at a distance of at least 5 meters from the driver, using a laser scanning type optical system that includes red, green, and blue laser light sources, collimator lenses, dichroic mirrors, and a micro-lens array to project a magnified image on the windshield, allowing for reduced eye movement and improved focus adjustment time, while preventing non-image segments from being irradiated to maintain visibility of the forward landscape.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a HUD displays virtual images at a short focal distance to enable compact design, then the device complexity is reduced, but the viewer's visibility deteriorates and eye strain increases

Engineering Contradiction:
Improveoptical system complexityVSAvoideye strain and visibility reduction
Core Design Contradiction:
Device complexityVSObject-affected harmful factors

Solution Approach 1:

The patent uses a combiner (intermediary optical element) to redirect and project the virtual image at a distance of 5 meters or more, allowing the HUD system to maintain compact design while eliminating eye strain by presenting the image at the driver's far point of focus

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent extends the virtual image distance from the traditional short focal distance to 5 meters or more by utilizing the windshield as a projection surface, effectively changing the spatial dimension of image presentation from near-field to far-field display

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

2Loss of information

If a HUD projects an image at a position that overlaps with objects in the forward view, then the information delivery is enhanced, but the visibility of both the image and objects deteriorates

Engineering Contradiction:
Improveinformation delivery effectivenessVSAvoidimage overlap with objects
Core Design Contradiction:
Loss of informationVSObject-affected harmful factors

Solution Approach 1:

The patent dynamically adjusts the image display position and parameters based on detected object information, allowing the HUD to adaptively avoid overlapping with objects in the driver's forward view while maintaining effective information delivery

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent uses object detection feedback from the vehicle's sensing system to control the HUD image positioning, creating a closed-loop system that prevents image-object overlap by continuously adjusting display parameters based on the forward environment

Inventive Principle:
Principle #23Feedback

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 configuration enhances driver visibility by reducing eye strain and improving recognition time of virtual images, allowing for better perception of distance and depth, and effectively prevents image overlap with objects, thereby enhancing the overall information delivery to the driver.

Implementation Method 1

red, green, and blue laser light sources

Methodology Applied
Scientific EffectLaser: Laser

Implementation Method 2

collimator lenses

Methodology Applied
Scientific EffectCollimation: Lens

Implementation Method 3

dichroic mirrors

Methodology Applied
Scientific EffectDichroic reflection: Dichroic Filter

Implementation Method 4

micro-lens array to project a magnified image

Methodology Applied
Scientific EffectLens focusing: Lens

Implementation Method 5

project a magnified image on the windshield

Methodology Applied
Scientific EffectPartial reflection: Reflection

Data Source

PatentEP3416377B1Image display apparatus and image display method
Publication Date: 2021.06.16 RICOH CO LTD
  • EP3416377B1 patent drawingFigure 1
  • EP3416377B1 patent drawingFigure 2
  • EP3416377B1 patent drawingFigure 3

AI summary

An image display apparatus includes a display section configured to display an image; a detecting section configured to detect an object at the same position as or near a position of the image; and a control section configured to control the image in response to determining overlap of the object with the image when viewed from a position of a visual point of a viewer viewing the image.