Aspheric Combiner Head-Up Display for Vehicle Virtual Image

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Solution Overview

Problem

Conventional head-up display (HUD) systems for vehicles are bulky, expensive, and suffer from image quality deterioration due to vibration, limited magnification, and require cooling systems, while also restricting the driver's field of view with VGA resolution.

Innovation Solution

A compact head-up display device using an aspheric combiner with specific optical ratios between the panel and combiner to create a large-sized virtual image with high magnification power without distortion, incorporating a panel with higher resolution than the displayed data to expand the driver's visible region.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional HUD components (panel, fold mirror, concave mirror) are used to create a virtual image, then driving data can be displayed to the driver, but the device volume increases and the product becomes expensive

Engineering Contradiction:
Improvedriving data transmissionVSAvoidHUD device volume
Core Design Contradiction:
ReliabilityVSVolume of moving object

Solution Approach 1:

The patent combines the panel and combiner into an integrated head-up display device, eliminating the need for separate fold mirrors and concave mirrors. The combiner performs both reflection and magnification functions that were previously handled by multiple separate components, thereby reducing device volume while maintaining the virtual image display function.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The combiner is designed to perform multiple functions simultaneously: it reflects image data from the panel, magnifies the image, and projects it to create a virtual image. This multi-functional design replaces several dedicated components (fold mirror, concave mirror) with a single element, reducing overall device complexity and volume.

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

2Reliability

If conventional HUD components are used to create a virtual image, then driving data can be displayed, but the number of components increases and manufacturing cost increases

Engineering Contradiction:
Improvedriving data transmissionVSAvoidnumber of components
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges multiple optical components (fold mirror, concave mirror) into a single combiner element, reducing the total number of components from three or more to two (panel and combiner). This simplification maintains the virtual image display function while reducing manufacturing complexity and cost.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The combiner is designed as a multi-functional component that performs reflection, magnification, and virtual image projection simultaneously. This eliminates the need for separate dedicated components for each function, thereby reducing device complexity and manufacturing cost.

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

3Reliability

If conventional HUD components are used, then a virtual image can be created, but image quality deteriorates due to vibration accumulation

Engineering Contradiction:
Improvevirtual image creationVSAvoidimage quality
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The patent removes the fold mirror from the optical path, eliminating an additional reflection surface that would accumulate vibration-induced image shaking. By using a direct optical path from panel to combiner to windshield, the system reduces the accumulation of vibration effects on image quality.

Inventive Principle:
Principle #2Taking out (Extraction)

4Quantity of substance

If a large-sized panel is used to display driving data, then more data can be transmitted, but the device requires a cooling system

Engineering Contradiction:
Improvedriving data capacityVSAvoidcooling system requirement
Core Design Contradiction:
Quantity of substanceVSDevice complexity

Solution Approach 1:

The patent eliminates the cooling system by using a combiner design that does not generate excessive heat. The optical design allows efficient light transmission and image projection without the thermal management requirements that would necessitate a cooling system, thereby reducing device complexity.

Inventive Principle:
Principle #2Taking out (Extraction)

5Quantity of substance

If VGA resolution panel is used, then driving data can be displayed, but the driver's visible region is limited

Engineering Contradiction:
Improvedriving data displayVSAvoiddriver's visible region
Core Design Contradiction:
Quantity of substanceVSArea of stationary object

Solution Approach 1:

The patent changes the resolution parameter of the panel from VGA to higher resolution (such as WXGA or Full HD). This parameter change allows the display of more driving data while the combiner's magnification function expands the visible region, enabling the driver to see more information within the same field of view.

Inventive Principle:
Principle #35Parameter 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 provides a compact, reliable, and high-quality HUD system with increased magnification power, minimizing distortion and maintaining image clarity, thus enhancing driver safety by keeping critical driving data within the driver's primary visual field without the need for cooling systems.

Implementation Method 1

a combiner, which magnifies and reflects the image data displayed on the panel

Methodology Applied
Scientific EffectReflection: Reflection

Implementation Method 2

an aspheric combiner, which magnifies the driving data displayed on the panel and thus creates a virtual image

Methodology Applied
Scientific EffectMagnification: Lens

Data Source

PatentEP1990675B1Head-up display device for vehicles
Publication Date: 2016.04.27 LG ELECTRONICS INC
  • EP1990675B1 patent drawingFigure 1~2
  • EP1990675B1 patent drawingFigure 3~4
  • EP1990675B1 patent drawingFigure 5~6

AI summary

Disclosed is a head-up display device for vehicles. The display device for vehicles includes a panel, on which driving data of a vehicle are displayed; and an aspheric combiner, which magnifies the driving data displayed on the panel and thus creates a virtual image, and has a ratio of DISC to CRC satisfying the below expression (here, 0<|DISC/CRC|<1.0, DISC representing the distance on an optical route between the panel and the combiner, and CRC representing the radius of curvature of the combiner).