Head-Up Display LCD Offset Layout for Glare-Safe Image Uniformity

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Solution Overview

Problem

Existing head-up displays are susceptible to damage from external light, which can cause non-uniform images and potential eye damage due to reflected light, and existing solutions do not adequately address these issues.

Innovation Solution

The LCD is rotated to be offset from the incident optical axis, with the light source and optical path control unit configured to maintain image uniformity and prevent direct light exposure, using a Fresnel lens to adjust light paths.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the LCD is rotated to be offset from the incident optical axis to prevent external light damage, then component protection and glare prevention are improved, but image uniformity deteriorates due to varying distances from the light source

Engineering Contradiction:
Improvecomponent protectionVSAvoidimage uniformity
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The patent applies asymmetry by intentionally offsetting the LCD from the incident optical axis to create an asymmetric configuration. This asymmetric arrangement prevents external light from directly entering the PGU and damaging components, while also preventing reflected light from reaching the driver's eye. The asymmetric positioning is the core design that resolves the contradiction between protection and image quality.

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The patent resolves the image uniformity issue by adding another dimension to the system - introducing an optical path control unit (such as a microlens array or light guide plate) that operates in the optical path dimension. This additional component compensates for the non-uniform light distribution caused by the offset LCD positioning, thereby maintaining image uniformity while preserving the protective asymmetric configuration.

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

2Object-affected harmful factors

If the LCD is rotated to be offset from the incident optical axis to prevent reflected light from reaching the user's eye, then driver safety is improved, but image uniformity deteriorates

Engineering Contradiction:
Improvereflected light to driver's eyeVSAvoidimage uniformity
Core Design Contradiction:
Object-affected harmful factorsVSManufacturing precision

Solution Approach 1:

The asymmetric offset positioning of the LCD relative to the incident optical axis is designed to redirect reflected external light away from the driver's line of sight. This asymmetric configuration ensures that even when external light enters the system, its reflection follows a path that does not reach the driver's eye, thereby improving driver safety while maintaining acceptable image quality through the optical path control unit.

Inventive Principle:
Principle #4Asymmetry

3Manufacturing precision

If the light source and LCD are arranged parallel to each other when offset from the incident optical axis, then image uniformity is improved, but light path control becomes more complex

Engineering Contradiction:
Improveimage uniformityVSAvoidoptical path control
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent merges the light source and LCD into a parallel arrangement when both are offset from the incident optical axis. This merging of their orientations simplifies the overall optical path control by creating a more regular, predictable light path geometry. The parallel configuration allows for more straightforward design of the optical path control unit, as the light travels in a more uniform manner from source to display panel.

Inventive Principle:
Principle #5Merging (Combining)

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

Prevents component damage and ensures uniform image projection by offsetting the LCD from the optical axis, maintaining image quality and user safety by avoiding direct light exposure and distortion.

Implementation Method 1

an optical path control unit, such as a Fresnel lens, is used to change the light path

Methodology Applied
Scientific EffectLight refraction: Refraction

Implementation Method 2

an optical path control unit, such as a Fresnel lens, is used to change the light path

Methodology Applied
Scientific EffectFresnel lens effect: Fresnel Lens

Data Source

PatentEP4312074B1Picture generation apparatus and head-up display including same
Publication Date: 2026.05.06 HYUNDAI MOBIS CO LTD
  • EP4312074B1 patent drawingFigure 1
  • EP4312074B1 patent drawingFigure 2
  • EP4312074B1 patent drawingFigure 3

AI summary

A picture generation apparatus including: a printed circuit board (PCB) on which one or more light sources are disposed; a Liquid Crystal Display (LCD) configured to emit an image using light transmitted from the one or more light sources; and an optical path control unit disposed between the PCB and the LCD, and configured to control a travel path of light, wherein the LCD is disposed to be offset from an incident optical axis of external light, and wherein the PCB is disposed to be parallel to the LCD.