Multifocal Head-Up Display Mirror Using Segmented Optical Paths
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Solution Overview
Problem
Existing head-up displays in vehicles are expensive due to the need for multiple components to achieve multifocal projection, limiting their availability to high-end vehicles.
Innovation Solution
A head-up display system with a single imaging unit, motor, and mirror that projects multiple image streams onto reflective areas with varying optical paths, allowing different depths of field, achieved through a motor-driven rotation synchronized by an angular sensor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If multiple collimating lenses and mirrors are used to achieve multifocal projection, then the display quality is improved, but the device complexity and manufacturing cost increase
Solution Approach 1:
The patent combines multiple optical functions (collimation and reflection) into a single mirror component with different reflective areas. Each reflective area has a different optical path length, enabling multifocal projection without requiring multiple separate collimating lenses and mirrors. This merging reduces device complexity while maintaining display quality.
Solution Approach 2:
The single mirror serves multiple functions: it acts as both a reflector and a collimator, and its different reflective areas provide different focal lengths simultaneously. This multi-functionality eliminates the need for separate optical components for each function, reducing overall system complexity.
2Adaptability or versatility
If multiple parts are used to achieve multifocal head-up display, then the projection capability is improved, but the production cost increases
Solution Approach 1:
The patent merges multiple optical components into a single mirror assembly with different reflective areas. This reduces the number of parts that need to be manufactured, assembled, and aligned, thereby reducing production costs while maintaining multifocal projection capability.
Solution Approach 2:
The mirror is segmented into multiple reflective areas, each with different optical path lengths. This segmentation allows the single mirror to provide multiple focal lengths, achieving multifocal capability without requiring multiple separate components, thus reducing manufacturing cost.
3Device complexity
If a single imaging unit is used to project multiple image streams, then the device complexity is reduced, but the projection speed and precision requirements increase
Solution Approach 1:
The single imaging unit projects image streams periodically by rotating to different positions to illuminate different reflective areas of the mirror. This periodic rotation enables the single imaging unit to serve multiple focal planes sequentially, reducing device complexity while maintaining projection speed through synchronized rotation and image capture.
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
Reduces production costs by simplifying the system to a single imaging unit and mirror, enabling multifocal projection without the need for multiple parts, making it accessible to a wider range of vehicles.
Implementation Method 1
a mirror comprising a plurality of reflective areas; and a combiner; and wherein each reflective area returns an image stream from the plurality of image streams to the combiner
Implementation Method 2
An aspherical lens or mirror decomposes the diverging LED light into parallel rays
Data Source
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AI summary
A head-up display system for a motor vehicle comprises: • an imaging unit (205) adapted to project a plurality of image streams onto; • a mirror (211) comprising a plurality of reflective areas (213-1, 213-2, 213-3); and • a combiner (215); and wherein • each reflective area returns an image stream from the plurality of image streams to the combiner, the optical path between the imaging unit and the combiner associated with a reflective area is of a different length from those of the optical paths associated with the other reflective areas so as to form on the combiner, planes (219-1, 219-2, 219-3) with different depths of field for each projected image stream; and the imaging unit is mobile in rotation around an axis (207) and driven by a motor (209) synchronized with the imaging unit to successively project each image stream onto a determined reflective area.A motor vehicle incorporating the system is also described.