Vehicle HUD Optical Unit with Diffractive Grating

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Solution Overview

Problem

Existing head-up display systems for vehicles face challenges in adjusting and integrating optical components in the driver's field of vision, leading to insufficient transparency and limited luminance, which compromises driving safety and comfort due to the technology used, such as holograms or semi-reflecting mirrors, failing to meet safety standards and readability requirements.

Innovation Solution

An optical unit with a first component that enlarges and increases the depth of field of the object image and a second transparent lenticular component with a diffractive grating for precise positioning of the virtual image in a vertical plane, ensuring high transparency and luminance without distorting the external scene, along with adjustable mechanisms for easy installation and alignment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If holograms or semi-reflecting mirrors are used for the optical component in the driver's field of vision, then the head-up display functionality is achieved, but the transparency is insufficient and driving safety is compromised

Engineering Contradiction:
Improvedriving safetyVSAvoidtransparency
Core Design Contradiction:
ReliabilityVSIllumination intensity

Solution Approach 1:

The optical component is segmented into multiple functional layers: a transparent substrate layer and a diffractive grating layer. This segmentation allows the substrate to maintain high transparency for safety while the grating layer provides the necessary optical modulation for head-up display functionality.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The diffractive grating is applied locally to specific regions of the transparent substrate rather than covering the entire component. This local quality approach ensures that transparency is maintained in areas where it is critical for safety, while optical modulation is provided only where needed for displaying vehicle parameters.

Inventive Principle:
Principle #3Local quality

2Loss of information

If the virtual image is made sufficiently large and luminous, then readability of vehicle parameters is improved, but the driver's attention to the external environment is disturbed

Engineering Contradiction:
Improvereadability of vehicle parametersVSAvoiddistraction from external environment
Core Design Contradiction:
Loss of informationVSObject-affected harmful factors

Solution Approach 1:

The virtual image is positioned in a third dimension (depth) above the dashboard rather than on the two-dimensional dashboard surface. This dimensional placement allows the image to be large and luminous for good readability while being optically separated from the driver's direct line of sight to the road, reducing distraction.

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

Solution Approach 2:

The diffractive grating acts as an intermediary that modulates light to create the virtual image. It enables the projection of large, luminous images while maintaining transparency, thus balancing readability requirements with the need to minimize distraction from the external environment.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Ease of operation

If existing head-up display systems are installed from the outset during vehicle construction, then optimal positioning and adjustment are achieved, but the complexity and cost of vehicle manufacturing increase

Engineering Contradiction:
Improveadjustment and positioningVSAvoidvehicle manufacturing complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The optical component design is universal and can be applied to various vehicle models and dashboard configurations. The compact optical unit with integrated adjustment mechanisms can be installed in different vehicles without requiring custom design for each model, reducing manufacturing complexity while maintaining ease of adjustment.

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

Solution Approach 2:

The optical component includes adjustable mechanisms that allow dynamic positioning and alignment after installation. This dynamic capability enables optimal adjustment during installation and potential re-adjustment later, eliminating the need for complex pre-adjustment procedures during vehicle manufacturing.

Inventive Principle:
Principle #15Dynamics

4Adaptability or versatility

If independent head-up display equipment is installed a posteriori by the user, then flexibility and ease of installation are improved, but the adjustment difficulty and integration challenges increase

Engineering Contradiction:
Improveflexibility of installationVSAvoidadjustment difficulty
Core Design Contradiction:
Adaptability or versatilityVSEase of operation

Solution Approach 1:

The optical component is pre-assembled as a compact integrated unit with all necessary adjustment mechanisms pre-configured. This preliminary assembly simplifies user installation to a single modular component while maintaining full adjustability capabilities, eliminating the need for complex post-installation adjustments.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The optical component includes self-adjusting features and user-friendly adjustment mechanisms that enable the end-user to perform alignment and positioning without requiring specialized skills or tools. The design allows users to easily optimize the display for their specific viewing conditions.

Inventive Principle:
Principle #25Self-service

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 provides a compact, easily adjustable optical unit that enhances the visibility and positioning of virtual images in the driver's field of vision, ensuring compliance with safety standards and improving the readability of vehicle parameters without degrading the external view, thus enhancing driving safety and comfort.

Implementation Method 1

a diffractive grating for positioning the final virtual image, said shape and the diffractive grating being provided so as not to deform the external scene visible to the driver through the second component

Methodology Applied
Scientific EffectDiffraction: Diffraction

Implementation Method 2

a first optical component reflecting the incident light rays coming from the headlamp in direction of a second optical component placed in the driver's field of vision

Methodology Applied
Scientific EffectReflection: Reflection

Implementation Method 3

the first component enlarges the object image and increases its depth of field and the second component positions the virtual image in a vertical plane

Methodology Applied
Scientific EffectLens refraction: Lens

Data Source

PatentEP2572229B1Head up display device
Publication Date: 2018.02.28 DELPHI TECHNOLOGIES INC
  • EP2572229B1 patent drawingFigure 1~2
  • EP2572229B1 patent drawingFigure 3
  • EP2572229B1 patent drawingFigure 4~5

AI summary

The invention relates to an independent optical unit for a head-up display system for a motor vehicle, for displaying, in the driver's (8) field of vision, a virtual image obtained from an object image (3) from a projector (9, 12). Said unit comprises a first optical component (1) reflecting the incident light beams from the projector (9, 12) towards a second optical component (2) placed in the driver's (8) field of vision, for the positioning of a final virtual image (7). The unit is provided with means for regulating the relative position of the components.