Vehicle Head-Up Display with Microlens Array and MEMS Scanning

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing display devices for mobile bodies, such as vehicles, face challenges in maintaining image quality due to factors like vibration and curvature of the windshield, which can lead to distortion and reduced image clarity.

Innovation Solution

A display system comprising a light source device, a light deflecting device, and a screen unit, where the screen unit is detachably attached to a housing with a microlens array, and the light deflecting device uses MEMS mirrors for scanning, ensuring high-contrast image formation and adjustment for different windshield curvatures, while the housing design minimizes vibration impact.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a display device is mounted on a mobile body (vehicle), then the display can be integrated into the mobile body structure, but vibration and curvature of the windshield cause image distortion and reduced image quality

Engineering Contradiction:
Improveintegration into mobile bodyVSAvoidimage quality
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The display device is divided into separate functional modules: a housing unit, a screen unit with microlens array, and a light deflecting device. This segmentation allows each component to be optimized independently and facilitates detachable attachment to the mobile body, reducing the impact of vibration and curvature on overall image quality.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A microlens array is introduced as an intermediary optical element between the light source and the windshield. The microlens array focuses and corrects the light paths, compensating for the curvature of the windshield and minimizing distortion caused by vibration, thereby maintaining image quality while enabling integration into the mobile body.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of repair

If the screen unit is detachably attached to the housing, then ease of maintenance and replacement is improved, but the structural stability may be reduced

Engineering Contradiction:
Improvemaintenance and replacementVSAvoidstructural stability
Core Design Contradiction:
Ease of repairVSStability of the object's composition

Solution Approach 1:

The display device is segmented into a housing unit and a screen unit that can be detachably attached. This segmentation enables easy maintenance and replacement of the screen unit without affecting the entire display system, while the detachable connection mechanism is designed to maintain sufficient structural stability during operation.

Inventive Principle:
Principle #1Segmentation

3Measurement precision

If MEMS mirrors are used for light deflecting, then scanning precision and image contrast are improved, but device complexity increases

Engineering Contradiction:
Improvescanning precisionVSAvoiddevice complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

Traditional mechanical scanning systems are replaced with MEMS (Micro-Electro-Mechanical Systems) mirrors, which use electrostatic actuation to deflect light at high precision. This substitution achieves superior scanning precision and image contrast while reducing the mechanical complexity of the scanning mechanism through miniaturization and integration.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

4Reliability

If the housing is designed to minimize vibration impact, then image quality is maintained, but the housing structure becomes more complex

Engineering Contradiction:
Improveimage qualityVSAvoidhousing structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The display device is segmented into a housing unit and a screen unit, allowing the housing to be designed with vibration-minimizing features while keeping the overall structure relatively simple. The detachable connection between units enables the housing to incorporate damping and isolation features without significantly increasing overall device complexity.

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 system maintains high image quality and reduces the occupied space, effectively suppressing image distortion caused by vibrations and curvature variations, enhancing the display's reliability and adaptability.

Implementation Method 1

a screen unit (300) including a microlens array

Methodology Applied
Scientific EffectLight transmission and focusing: Lens

Implementation Method 2

the light deflecting device uses MEMS mirrors for scanning

Methodology Applied
Scientific EffectLight reflection and deflection: Reflection

Data Source

PatentEP3660577B1Display device and mobile body
Publication Date: 2023.02.22 RICOH CO LTD
  • EP3660577B1 patent drawingFigure 1~2
  • EP3660577B1 patent drawingFigure 3
  • EP3660577B1 patent drawingFigure 4

AI summary

A display device (10) and a mobile body (1A). The display device (10) includes a light source (11), an image forming unit (13) configured to receive irradiation light emitted from the light source (11) and emit image light for forming an image, a screen (15) on which the image light forms an image, a housing (10A) configured to contain the light source (11) and the image forming unit (13), and a holding member (300) configured to hold the screen (15) and attached to the housing (10A). The mobile body (1A) includes the display device (10), and the screen (15) is configured to diffuse and project the image light. The mobile body (1A) further includes a front glass (50) configured to reflect the image light, and an image-forming optical system (30) configured to project, toward the front glass (50), the image light projected from the screen (15).