Head-Up Projection Optics With Dual Diffusers for Sun Reflection Control

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing head-up display systems face challenges in achieving uniform illumination of projected information and preventing unwanted reflections from external light sources, particularly the sun, which hinder visibility and readability.

Innovation Solution

A projection device for head-up displays uses two diffusers with distinct optical diffusion characteristics, separated by a distance, and an imaging screen, where the second diffuser is inclined relative to the light beam, to enhance diffusion flexibility and prevent unwanted reflections.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a conventional dashboard layout is used, then the driver can access control elements, but the driver's field of vision is blocked and attention must be diverted from the road

Engineering Contradiction:
ImproveDriver access to control elementsVSAvoidDriver attention and field of vision
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent projects the dashboard interface from the traditional horizontal plane onto a vertical plane (the windshield), transforming the spatial dimension of information display. This allows the driver to view controls and information in the peripheral vision area without diverting attention from the road, resolving the contradiction between ease of operation and driving safety.

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

2Ease of operation

If the dashboard is positioned closer to the driver, then control accessibility improves, but the space available for mounting the dashboard decreases

Engineering Contradiction:
ImproveControl accessibilityVSAvoidDashboard mounting space
Core Design Contradiction:
Ease of operationVSArea of stationary object

Solution Approach 1:

The patent introduces a projection system as an intermediary between the driver and the dashboard controls. Instead of physically relocating the dashboard, the projection system creates a virtual interface on the windshield, allowing close positioning of physical controls while maintaining full accessibility through the projected overlay.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Area of stationary object

If the dashboard is positioned farther from the driver, then more mounting space is available, but control accessibility and visibility deteriorate

Engineering Contradiction:
ImproveDashboard mounting spaceVSAvoidControl visibility and accessibility
Core Design Contradiction:
Area of stationary objectVSEase of operation

Solution Approach 1:

By projecting the dashboard interface onto the vertical windshield surface, the patent extends the effective display area without consuming additional horizontal mounting space. This dimensional transformation allows the dashboard to be positioned optimally for mounting while maintaining full control visibility through the projection.

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

4Ease of operation

If traditional dashboard controls are used, then the driver can interact with controls, but the driver must divert attention from the road to the dashboard

Engineering Contradiction:
ImproveDriver interaction with controlsVSAvoidDriver focus on road
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent transforms the dashboard from a horizontal surface requiring direct gaze to a vertical projection on the windshield that falls within the driver's natural field of vision. This allows drivers to interact with controls while maintaining road focus, eliminating the need to divert attention.

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

Solution Approach 2:

The projection system uses luminous or illuminated elements that stand out against the windshield background, making controls visible without requiring the driver to actively search or shift focus. The visual properties of the projection ensure detectability within the existing field of vision.

Inventive Principle:
Principle #32Color changes

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 ensures uniform illumination and minimizes unwanted reflections, improving visibility and readability of projected information by directing light beams effectively to the driver's field of view.

Implementation Method 1

a projection system for projecting an image onto the windshield

Methodology Applied
Scientific EffectProjection:

Data Source

PatentEP3807680B1Projecting apparatus and associated head-up viewing system
Publication Date: 2026.04.29 VALEO COMFORT & DRIVING ASSISTANCE
  • EP3807680B1 patent drawingFigure 1

AI summary

The invention relates to a projecting apparatus (2) intended for a head-up viewing system (1) for a driver (9) of a vehicle. The projecting apparatus (2) includes, from upstream to downstream of a luminous display path toward the driver (9), at least one device (3) for generating a light beam (12, 13, 14, 15), a first diffuser (4) having a first scattering optical indicatrix, a second diffuser (5) having a second scattering optical indicatrix and an imager screen (6), the first diffuser (4) and the second diffuser (5) being separated by a determined distance. The first scattering optical indicatrix is different from the second scattering optical indicatrix. A head-up viewing system is also proposed.