Concave Mirror Head-Up Display Aligning Light Paths
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Solution Overview
Problem
Existing head-up display systems experience double image issues due to light beams reflecting off the front and rear surfaces of transparent objects like windshields, which requires special processing of the windshield into a wedge shape to align reflections, but a method is needed to prevent double images without such processing.
Innovation Solution
A display apparatus and method using a concave mirror to reflect light beams from a display surface toward a transparent member, ensuring that first and second light beams incident on the transparent member from a single point are parallel, and adjusting the concave mirror's curvature or distance to align their optical paths post-reflection, allowing the transparent member to present a virtual image without needing a wedge shape.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the transparent member is processed into a wedge shape to prevent double image, then the double image is suppressed, but the manufacturing complexity and cost increase
Solution Approach 1:
A beam splitter is introduced as an intermediary component between the image display unit and the transparent member. The beam splitter divides the light beam into a first light beam (reflected toward the user) and a second light beam (transmitted through the transparent member). This intermediary device enables precise control of light paths without requiring wedge-shaped processing of the transparent member, thereby suppressing double images while maintaining manufacturing simplicity.
Solution Approach 2:
The invention changes the optical parameters by using a beam splitter with specific reflection and transmission characteristics. By adjusting the optical path lengths and angles through the beam splitter, the light beams are controlled to converge at the same virtual image position, eliminating double images without modifying the physical shape parameters of the transparent member.
2Manufacturing precision
If the transparent member is processed into a wedge shape to align light beams, then the optical path alignment is improved, but the device complexity increases
Solution Approach 1:
The beam splitter serves as a mediating optical element that precisely controls the division and redirection of light beams. It enables accurate optical path alignment by reflecting one portion of the light and transmitting another portion, allowing both beams to converge at the correct virtual image position without requiring complex wedge-shaped processing of the transparent member.
Solution Approach 2:
The light beam is segmented into two separate paths by the beam splitter - a first light beam reflected toward the user and a second light beam transmitted through the transparent member. This segmentation allows independent optimization of each optical path, achieving precise alignment while keeping the overall device structure simple and the transparent member unprocessed.
3Reliability
If a beam splitter is used to divide light beams, then the virtual image presentation is improved, but the device complexity increases
Solution Approach 1:
The beam splitter performs multiple functions simultaneously: it divides the light beam into reflected and transmitted portions, controls optical path lengths, and ensures convergence of both beams at the virtual image position. By consolidating these functions into a single component, the device achieves reliable virtual image presentation without proportionally increasing complexity.
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 approach effectively suppresses the occurrence of double images in head-up displays when the transparent member is not processed into a wedge shape, reducing costs and complexity by using standard transparent members.
Implementation Method 1
a concave mirror configured to reflect light beams from the display surface toward a transparent member
Implementation Method 2
a transparent member reflecting some of the light beams that have been input thereto and transmitting the remaining light beams
Implementation Method 3
transmitting the remaining light beams that have been input thereto
Data Source
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AI summary
A display apparatus (1) includes: a display surface (10) configured to display an image; and a concave mirror (11) configured to reflect light beams from the display surface (10) toward a transparent member (2) reflecting some of the light beams that have been input thereto and transmitting the remaining light beams that have been input thereto, in which a virtual image of the image is presented by the transparent member (2). An optical path after a first light beam (L1) is reflected in the transparent member (2) coincides with an optical path after a second light beam (L2) is reflected in the transparent member (2) by the reflection in the concave mirror, the first light beam (L1) reaching the transparent member (2) from one point on the display surface (10) and reflecting on a front surface (21) of the transparent member (2), and the second light beam (L2) reaching the transparent member (2) from the one point and reflecting on a rear surface (22) of the transparent member (2).