Head-Up Display Projection Adjustment via Mirror Rotation
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Solution Overview
Problem
Existing head-up display devices face challenges in adjusting the projection position of display light based on the observer's viewpoint height without vertically moving the virtual image, leading to issues such as image deviation and reduced brightness.
Innovation Solution
A head-up display device with a concave mirror and two driving mechanisms, where the concave mirror's inclination and the case's longitudinal position are adjusted using stepping motors and control means to maintain the virtual image's vertical position while adjusting the projection point based on the observer's viewpoint height.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a plane mirror is used to adjust the projection position of display light, then the projection position can be adjusted, but the incident position and incident angle to the front glass are uniquely determined, causing the virtual image to vertically move and deviate
Solution Approach 1:
The patent employs dynamic control of the plane mirror's inclination angle through a driving mechanism, allowing independent adjustment of the projection position while maintaining virtual image stability. The mirror angle is dynamically changed based on detected observer height, enabling the system to adapt to different viewing conditions without causing vertical image displacement.
2Manufacturing precision
If the display and concave mirror are moved along an arc to adjust projection position, then the virtual image position can be maintained, but space is required in longitudinal and vertical directions, increasing the device size
Solution Approach 1:
Instead of moving components along an arc in longitudinal and vertical directions, the patent changes the adjustment dimension by rotating the plane mirror around a fixed axis. This angular adjustment in a different dimensional space achieves the same projection position variation without requiring large physical displacement space, thereby reducing device volume.
3Manufacturing precision
If a semitransparent reflection mirror is used to adjust projection position, then the projection position can be adjusted without moving the virtual image, but the mirror decreases brightness of the virtual image
Solution Approach 1:
The patent changes the key parameter of the reflecting surface from semitransparent to fully reflective. By using a regular plane mirror with high reflectivity instead of a semitransparent mirror, the system maintains the ability to adjust projection position while significantly improving the brightness of the virtual image, as all incident light is reflected rather than partially transmitted.
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
Enables adjustment of the display light projection position according to the observer's height without vertically moving the virtual image, reducing the device's size and maintaining image brightness by eliminating the need for a semi-transparent mirror.
Implementation Method 1
a display 20, a concave mirror 30 that reflects the display light L emitted from the display 20 toward a front glass 201 of the vehicle 200
Data Source
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AI summary
Provided is a head up display device with which it is possible to adjust the projection location of display light depending on the height of the observer's point of view, without moving the virtual image in the vertical direction. This head up display device (100) is provided with: a case (10) which retains a display (20) and a concave mirror (30) in a prescribed positional relationship; a first driving means (40) which rotates the concave mirror (30); a second driving means (50) which moves the case (10) frontward and rearward; and a control means which operates the first and second drive means (40, 50) in accordance with information about the viewpoint position of the observer, and adjusts the projection location of display light (L) on front glass (201) depending on the height of the observer's point of view.