HUD Optical Element Moves Partial Video to Adjust Light Path
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Solution Overview
Problem
Conventional head-up display systems face a decrease in virtual image resolution due to the need to increase the depth of focus of the optical system, which results in reduced image clarity when projecting information at different distances from the driver in a vehicle.
Innovation Solution
A display device comprising a video display, optical elements, and a projector, where the optical elements move partial videos on the display surface to different positions in the projection direction, allowing the projector to project virtual images with improved resolution by adjusting the light path and reducing the depth of focus, thereby enhancing the clarity of images at various distances.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple screens are disposed at different distances from the projection target member to form virtual images at different distances, then virtual images at different distances can be formed, but the depth of focus of the optical system increases, reducing image resolution
Solution Approach 1:
The patent divides the single projection system into multiple independent projection units, each projecting to a separate screen at a different distance. This segmentation allows each optical system to maintain a fixed, optimized focal length for its specific screen distance, avoiding the need for a large depth of focus and thereby maintaining high image resolution across multiple virtual image distances
Solution Approach 2:
The patent transitions from a single-dimensional approach (one screen at one distance) to a multi-dimensional approach by arranging multiple screens at different distances along the optical axis. This spatial arrangement in multiple dimensions enables the formation of virtual images at different distances while each screen maintains its own optimized focal point, resolving the contradiction between adaptability and resolution
2Adaptability or versatility
If the depth of focus of the optical system is increased to accommodate multiple screen distances, then virtual images at different distances can be projected, but scattered light increases and image clarity decreases
Solution Approach 1:
By segmenting the projection system into multiple independent units, each projecting to a specific screen at a fixed distance, the patent eliminates the need for a large depth of focus. This segmentation confines light paths to specific focal planes, reducing scattered light and improving image clarity while still enabling virtual images at different distances
Solution Approach 2:
The patent introduces multiple screens as intermediary elements at different distances between the projection units and the driver's eye. Each screen acts as an intermediary that captures and redirects light at a specific focal distance, preventing light from scattering across multiple focal planes and thereby reducing scattered light while enabling multi-distance virtual image projection
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 improves the resolution of virtual images projected at different distances, reducing the depth of focus and minimizing scattered light, resulting in clearer and more distinct virtual images for the driver, while maintaining a compact design without the need for multiple screens at different distances.
Implementation Method 1
The at least one optical element moves a partial video, which is a part of the video displayed on the video display surface, to a position distant from the video display in a projection direction in which the video is projected
Implementation Method 2
The projector projects a virtual image viewed by a user by projecting light output from the video display and the at least one optical element to a reflecting member
Data Source
AI summary
A display device includes: a video display that displays a video for projecting a virtual image onto a target space on a video display surface; an optical element; and a projector. The optical element moves a partial video, which is a part of the video displayed on the video display surface, to a position distant from the video display in a projection direction in which the video is projected. The projector projects a virtual image viewed by a user by projecting light output from the video display and the optical element to a reflecting member. The optical element has an incident surface on which the partial video is incident, and an emitting surface from which the partial video incident on the incident surface emits. The incident surface and the emitting surface are parallel to each other.