Light Deflector Mirror Diameter for HUD Brightness and Resolution
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Display systems, such as heads-up displays (HUDs), face challenges in maintaining image brightness without reducing resolution, especially when projecting information onto curved surfaces like vehicle windshields, where the image quality can be affected by the curvature and the need for wide viewing angles.
Innovation Solution
The display system incorporates a light deflector that scans light in both main and sub-scanning directions to form an intermediate image, which is then projected onto a free-form surface mirror and windshield, using a microlens array to diverge light and maintain image quality by optimizing the effective diameter of the mirror and the image size ratio, ensuring the beam spot diameter is controlled relative to the lens diameter.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If the beam diameter is increased to maintain image brightness, then the image brightness is improved, but the resolution deteriorates because the beam diameter becomes larger than the pitch of micromirror array or microlens array elements
Solution Approach 1:
The optical system is divided into multiple microlens arrays or micromirror arrays with specific pitches. By segmenting the light beam into multiple discrete elements rather than using a single continuous beam, the system can maintain resolution while improving brightness through additive light contribution from multiple elements.
Solution Approach 2:
The patent optimizes the beam diameter to be equal to or greater than the pitch P but less than twice the pitch P (P ≤ D < 2P). This parameter optimization allows the beam to cover multiple elements effectively for brightness while maintaining sufficient separation for resolution, resolving the contradiction between brightness and resolution.
2Adaptability or versatility
If the image size is increased to provide wide viewing angles, then the viewing angle is improved, but the image brightness decreases due to light spreading over a larger area
Solution Approach 1:
The patent introduces a sub-scanning direction in addition to the main scanning direction, creating two-dimensional light deflection. This dimensional expansion allows the system to achieve wide viewing angles through angular distribution rather than spatial expansion, maintaining brightness while improving viewing angle.
Solution Approach 2:
The light deflector dynamically scans light in both main and sub-scanning directions to form intermediate images, creating a dynamic optical path that adapts to different viewing positions. This dynamic scanning approach maintains concentrated light intensity while expanding the effective viewing area.
3Use of energy by moving object
If the effective diameter of the mirror is increased to improve light collection, then the light utilization efficiency is improved, but the device size increases
Solution Approach 1:
The mirror in the light deflector serves multiple functions: it reflects light for scanning, forms intermediate images, and controls beam direction. By making the mirror multi-functional rather than dedicated to a single purpose, the system achieves high light utilization efficiency with a compact mirror size, avoiding the need for larger single-purpose optical elements.
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 configuration maintains image brightness and resolution while allowing for wide viewing angles, reducing coherent noise and improving light utilization efficiency, thus enhancing the overall display quality on curved surfaces.
Implementation Method 1
an optical device through which light diverges
Implementation Method 2
a light deflector configured to scan a light emitted from a light source in a main scanning direction and a sub-scanning direction orthogonal to the main scanning direction to form an intermediate image on the optical device
Implementation Method 3
using a microlens array to diverge light and maintain image quality
Implementation Method 4
an imaging optical system configured to project diverging light diverging through the optical device to form an image
Data Source
AI summary
A display system, a mobile object, and an optical element. The display system includes an optical device through which light diverges, a light deflector configured to scan a light emitted from a light source in a main scanning direction and a sub-scanning direction orthogonal to the main scanning direction to form an intermediate image on the optical device, and an imaging optical system configured to project diverging light diverging through the optical device to form an image. An effective diameter a of a mirror of the light deflector for the intermediate image and a ratio c of a size of an image formed by the imaging optical system to the effective diameter a satisfy a condition in an equation given below.2≥0.007a−2c2+0.75a−0.75c+0.5a−0.5 The mobile object includes the display system, and the reflector is a front windshield. The optical element is used for the display system.