Projection Lens Asymmetric Axis Shift for Wide Angle Control
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Solution Overview
Problem
Existing projection lenses face challenges in maintaining a wide angle of view without increasing size and minimizing distortion, particularly in projection applications where a wide angle is required, such as in automotive dashboards projecting images onto windshields.
Innovation Solution
A projection lens design with an optical system that includes an incidence lens and an emission lens, where the incidence optical axis is shifted orthogonally to the center of the electrooptic element's screen, and the emission optical axis is tilted to maintain a projection angle less than 90 degrees, using a reflecting part to deflect the optical axis and adjust the tilt angle, thereby controlling distortion and size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the projection lens uses a wide angle of view (ω≥60°), then the field of view is improved, but the distortion increases and the size increases
Solution Approach 1:
The patent applies parameter changes by optimizing the projection angle to be less than 90 degrees and controlling the PA value within a specific range (0.1-7). This adjusts the optical parameters to achieve a wide field of view while maintaining acceptable distortion levels and controlling the lens size.
Solution Approach 2:
The patent employs asymmetry by shifting the incidence optical axis orthogonally to the center of the electrooptic element's screen. This asymmetric optical axis configuration allows the lens to achieve wide-angle performance while controlling distortion characteristics that would otherwise be problematic in symmetric wide-angle designs.
2Adaptability or versatility
If the projection lens uses a wide angle of view (ω≥60°), then the field of view is improved, but the size of the lens increases
Solution Approach 1:
The patent controls lens size by adjusting the PA parameter to fall within the range of 0.1 to 7 and setting the projection angle to less than 90 degrees. These parameter changes enable the optical system to achieve wide-angle performance without requiring an excessively large lens diameter or focal length.
Solution Approach 2:
The patent shifts the incidence optical axis in a direction orthogonal to the center of the electrooptic element's screen. This dimensional change in the optical path configuration allows the system to achieve wide field of view without proportionally increasing the lens size, as the light path is redirected through a different spatial dimension.
3Manufacturing precision
If the projection angle is reduced to less than 90 degrees, then the distortion is suppressed, but the optical path becomes more complex
Solution Approach 1:
The patent incorporates asymmetry by shifting the incidence optical axis orthogonally to the center of the electrooptic element's screen. This asymmetric configuration, combined with the projection angle less than 90 degrees, suppresses distortion while the complexity is managed through systematic optical design.
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 design effectively suppresses both the increase in size and distortion of the projection lens while maintaining a wide angle of view, achieving a balance between optical performance and practical installation constraints.
Implementation Method 1
a reflecting part that deflects an optical axis, in which the reflecting part deflects the optical axis on an incidence side of the reflecting part toward the emission optical axis
Data Source
AI summary
A projection lens having an optical system includes: an incidence lens on which light from an electrooptic element is incident; and an emission lens positioned closest to a magnification side and emits an image toward a projection surface, in which an incidence optical axis of the incidence lens is shifted in a first direction orthogonal to the incidence optical axis with respect to a center of a screen of the electrooptic element, a projection angle, which is an angle of an emission optical axis of the emission lens with respect to the projection surface, is less than 90°, and assuming an effective diameter of the emission lens is DE, a focal length of an entire optical system including the emission lens is f, and a half angle of view of the entire optical system is ω, ω is ≥60°, and a value of PA defined by Expression (1)≥0.1 and ≥7. PA=DE/(f×tan ω) (1).