HUD Picture Generator Double-Funnel Reflector for Edge Brightness

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Solution Overview

Problem

Existing head-up display systems face issues with reduced brightness and non-uniformity of light at the outer edges, particularly in daylight conditions, due to the design of the housing funnel and diffuser angles, leading to inadequate visibility for drivers.

Innovation Solution

A double funnel structure with a filleted outermost edge and optimized internal optical surfaces, including a first and second funnel design, enhances light uniformity and brightness by guiding and mixing light from multiple sources uniformly onto the LCD.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single funnel structure with diffuser is used, then the device complexity is low, but the light uniformity and brightness at the outer edges deteriorate

Engineering Contradiction:
Improvefunnel structure complexityVSAvoidlight uniformity and brightness
Core Design Contradiction:
Device complexityVSIllumination intensity

Solution Approach 1:

The single funnel structure is divided into two separate funnels (first funnel and second funnel) with different orientations. The first funnel has its optical axis inclined at angle α relative to the normal of the light source, while the second funnel has its optical axis inclined at angle β. This segmentation allows each funnel to independently optimize light collection from different angles, resulting in improved light uniformity and brightness at the outer edges of the LCD without significantly increasing device complexity.

Inventive Principle:
Principle #1Segmentation

2Ease of manufacture

If the diffuser angle differs from the LCD angle, then the ease of manufacture is improved, but the light uniformity deteriorates due to refraction

Engineering Contradiction:
Improveassembly easeVSAvoidlight uniformity
Core Design Contradiction:
Ease of manufactureVSIllumination intensity

Solution Approach 1:

The system uses two separate funnels with differently oriented optical axes to compensate for the angle mismatch between diffuser and LCD. The first funnel collects light at angle α and the second funnel collects light at angle β, allowing the system to maintain manufacturing simplicity while achieving uniform light distribution across the LCD surface despite the angular difference between diffuser and LCD components.

Inventive Principle:
Principle #1Segmentation

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 achieves improved brightness of 16,186 cd/m² or more and uniformity of 72% or higher, ensuring enhanced visibility and consistent light distribution across the entire display area.

Implementation Method 1

The internal optical surface 120 may include a first funnel 122 and a second funnel 124... guide optical beams from the plurality of light sources to the display unit

Methodology Applied
Scientific EffectLight reflection: Reflection

Implementation Method 2

the outermost edge of the internal optical surface 120 is formed in a fillet shape... the brightness of light emitted to an outermost edge of an LCD may be improved

Methodology Applied
Scientific EffectLight refraction: Refraction

Data Source

PatentEP4393744B1Picture generating apparatus for use in head-up display
Publication Date: 2025.10.22 HYUNDAI MOBIS CO LTD
  • EP4393744B1 patent drawingFigure 1A~1B
  • EP4393744B1 patent drawingFigure 2
  • EP4393744B1 patent drawingFigure 3

AI summary

An apparatus for generating pictures for a head-up display includes: a printed circuit board (PCB) including a plurality of light sources; a liquid crystal display (LCD) disposed in front of the plurality of light sources and forming display images based on light emitted from the plurality of light sources; a funnel reflector including an internal optical surface including a double funnel structure and disposed between the PCB and the LCD to guide the light to the LCD; a housing including a space for accommodating the funnel reflector and including, on an upper surface thereof, an LCD seat for accommodating the LCD and a diffuser seat formed at the same angle as the LCD seat; and a diffuser accommodated in the diffuser seat, wherein the funnel reflector includes a tapered top surface and the top surface is formed at an angle corresponding to an angle of the diffuser seat to maintain a uniform distance from the diffuser.