Resin Protection Cover Aspherical Surface Distortion Correction
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Solution Overview
Problem
Existing optical systems for surveillance cameras face challenges in achieving a wide angle of view while maintaining compactness and low distortion, often requiring an increased number of lenses which enlarges the system.
Innovation Solution
The optical system incorporates a protection cover made of resin with an aspherical surface that continuously changes from the optical axis to the peripheral portion, correcting distortion and allowing for a wide angle of view while keeping the system small, using a configuration where the protection cover is part of the lens configuration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the number of lenses is increased to correct distortion, then distortion correction is improved, but the size of the entire system increases
Solution Approach 1:
The invention merges the protection cover function with the optical lens function by forming an aspherical surface directly on the protection cover. This integration eliminates the need for separate distortion correction lenses, reducing the total number of optical elements while achieving effective distortion correction through the aspherical geometry of the unified structure.
Solution Approach 2:
The invention applies aspherical curvature to the protection cover surface, replacing traditional spherical or flat surfaces. This aspherical shape is specifically designed to correct distortion aberrations in wide-angle optical systems, allowing distortion correction without adding multiple corrective lenses that would increase system size.
2Area of moving object
If a negative lead type optical system is used to achieve wide angle of view and compactness, then angle of view and system size are improved, but distortion occurs in the peripheral part of the image
Solution Approach 1:
The invention introduces an aspherical surface on the protection cover to counteract the distortion inherent in negative lead type wide-angle optical systems. The aspherical curvature is specifically designed to compensate for barrel distortion in peripheral areas, maintaining straight lines and geometric accuracy while preserving the wide angle of view and compact system dimensions.
Solution Approach 2:
The aspherical surface applies localized optical correction specifically where distortion occurs (in peripheral regions) while maintaining the overall wide-angle performance. The curvature varies across the surface, providing targeted distortion correction in areas where it is most needed without compromising the central image quality or system compactness.
3Reliability
If a protection cover is provided closest to the object side to protect the optical system, then protection is improved, but distortion correction becomes more difficult
Solution Approach 1:
The invention combines the protection cover and optical correction elements into a single integrated component. The aspherical surface is formed directly on the protection cover, allowing it to simultaneously provide mechanical protection and optical distortion correction. This eliminates the need for additional corrective lenses that would be required if the protection cover had a simple flat or spherical surface.
Solution Approach 2:
The protection cover is designed to perform multiple functions: mechanical protection of the optical system, optical focusing, and distortion correction through its aspherical surface. This multi-functional design allows the single component to replace what would traditionally require multiple separate elements, maintaining protection while achieving effective distortion correction.
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 solution effectively corrects distortion and maintains high optical performance across the zoom range, reducing the system's size and minimizing distortion, especially in the peripheral areas of the image.
Implementation Method 1
The protection cover includes an aspherical surface whose shape changes continuously from an optical axis to a peripheral portion
Data Source
AI summary
Provided is an optical system according to the present invention, comprising a protection cover made of resin and a lens portion arranged in order from an object side to an image side, in which the protection cover includes an aspherical surface whose shape changes continuously from an optical axis to a peripheral portion, and where an effective diameter of the aspherical surface is represented as 2×ha, a distance sag1 in a direction of the optical axis between the aspherical surface and a reference spherical surface of the aspherical surface at a position where the height from the optical axis is ha, and a thickness tc of the protection cover on the optical axis are appropriately set.