Head-Up Display Optical Layout for Compact 3D Stray Light Control
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Solution Overview
Problem
Existing head-up displays are large in size and struggle to effectively inhibit stray light caused by outside light, especially with the emergence of three-dimensional virtual images.
Innovation Solution
A head-up display configuration that includes a display device, a projection optical system with a first optical element to condense light, a first lens to condense light, and a second optical element to diffuse light, arranged in a telephoto arrangement to form an intermediate image, reducing the size of the display while inhibiting stray light.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If a conventional head-up display configuration is used, then the display can project images, but the device becomes large in size
Solution Approach 1:
The projection optical system is divided into multiple discrete optical elements (first optical element, first lens, second optical element) arranged in sequence. Each element performs a specific function: the first optical element condenses light, the first lens further condenses and focuses light, and the second optical element diffuses light. This segmentation allows for compact arrangement while maintaining effective stray light inhibition through coordinated action of the elements
Solution Approach 2:
The first lens acts as an intermediary element between the first optical element and the second optical element. It receives condensed light from the first optical element, further condenses and focuses it to form an intermediate image, and then directs it to the second optical element for diffusion. This intermediary function enables compact system design while effectively managing light paths to inhibit stray light
2Volume of moving object
If the head-up display size is reduced, then compactness is achieved, but stray light inhibition becomes difficult
Solution Approach 1:
Each optical element in the projection system is designed with specific local properties: the first optical element has light-condensing properties, the first lens has both condensing and focusing properties with specific focal length, and the second optical element has light-diffusing properties. These localized quality assignments allow the compact system to effectively manage light paths and inhibit stray light through the coordinated optical properties of each element
Solution Approach 2:
The optical elements are arranged in an asymmetric configuration optimized for compactness and stray light inhibition. The first optical element, first lens, and second optical element are positioned at specific asymmetric locations along the optical path, with the first lens having a specific focal length relationship to the distance between elements. This asymmetric arrangement enables effective stray light management in a reduced-size configuration
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 configuration provides a less distorted virtual image and effectively inhibits stray light, achieving a reduction in size of the head-up display without adding additional components.
Implementation Method 1
a first optical element configured to condense light
Implementation Method 2
a first lens configured to condense light
Implementation Method 3
a second optical element configured to diffuse light
Implementation Method 4
The projection optical system is configured to form the image as an intermediate image
Data Source
AI summary
A head-up display is configured to project an image on a transparent reflection member to cause an observer to visually recognize a virtual image, and includes a display device configured to display the image, and a projection optical system configured to project the image displayed by the display device as the virtual image for the observer. The projection optical system is configured to form the image as an intermediate image, and includes a first optical element configured to condense light, a first lens configured to condense light, and a second optical element configured to diffuse light. The first optical element, the first lens, and the second optical element are disposed in this order along an optical path from the display device.