Vehicle Head-Up Display Optical Path Merging for Compact Projection
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Solution Overview
Problem
Head-up display devices for vehicles face limitations in enlarging display images while minimizing the enlargement of the optical system's displacement space, particularly in vertical directions, which restricts the ability to increase the display image size without significantly expanding the optical system's dimensions, making it challenging to fit within limited dashboard spaces.
Innovation Solution
A display device configuration that includes a projector with a beam splitter and mirrors, where the projector emits two images with different paths, allowing the beam splitter to transmit one image and reflect the other, enabling the projection of these images onto a windshield as a virtual image, thereby enlarging the display image while sharing light paths to minimize the optical system's enlargement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of moving object
If the display image size is enlarged, then the visibility and information density are improved, but the optical system's displacement space and dimensions are significantly increased
Solution Approach 1:
The patent combines the projection paths for different color components (R, G, B) into a shared optical path after the liquid crystal panels. The light guiding members (beam splitters and mirrors) merge the separate projection paths, allowing multiple images to be projected through a common optical system, thereby enlarging the display image without proportionally increasing the optical system dimensions.
Solution Approach 2:
The patent utilizes the vertical space dimension by arranging liquid crystal panels and light guiding members in a stacked configuration. The beam splitters and mirrors are positioned at different vertical levels, allowing light paths to be folded and merged in the vertical dimension, which enables compact horizontal footprint while achieving large display image size.
2Area of moving object
If the optical system dimensions are increased to enlarge the display image, then the display image size is improved, but the device becomes difficult to fit within limited dashboard spaces
Solution Approach 1:
The patent implements a nested arrangement where light guiding members (beam splitters and mirrors) are positioned within and between the liquid crystal panel assemblies. The optical components are integrated into the vertical stack, with each layer containing both display elements and optical guiding elements, creating a compact nested structure that minimizes overall volume.
Solution Approach 2:
The optical system utilizes vertical stacking to accommodate multiple light paths and optical components. By folding the light paths in the vertical dimension using beam splitters and mirrors positioned at different heights, the system achieves large display image area without requiring proportional increases in horizontal or overall volumetric dimensions.
3Manufacturing precision
If separate projection paths are used for different color components, then color accuracy is improved, but the optical system complexity and space requirements increase
Solution Approach 1:
The patent uses beam splitters to separate and then recombine light paths for different color components. Each liquid crystal panel processes a specific color component (R, G, or B) independently to maintain color accuracy, but the light guiding members merge these separate paths into a common projection path, reducing overall system complexity compared to completely separate projection systems for each color.
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
This configuration effectively enlarges the display image in both horizontal and vertical directions without significantly increasing the optical system's size, enhancing visibility and information density while maintaining a compact optical system, suitable for vehicle dashboards.
Implementation Method 1
The beam splitter projects the image to a display medium by transmitting the incident first image and reflecting the incident second image
Implementation Method 2
The first mirror projects the incident first image to the display medium by reflecting the incident first image
Data Source
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AI summary
This display device is provided with a display unit, a beam splitter, and a first mirror. The display unit emits a first image and a second image. The beam splitter has, incident thereon, the first image and the second image which are emitted from the display unit. The beam splitter transmits the incident first image and reflects the incident second image to project the first image and the second image on a display medium. The first mirror has, incident thereon, the first image which has been transmitted through the beam splitter. The first mirror reflects the incident first image to project the first image on the display medium.