Super-Wide-Angle Zoom Lens with Fixed Negative-Power Unit
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing super-wide-angle zoom lenses face challenges in sufficiently suppressing aberrational fluctuations during zooming and reducing the weight of the movable lens unit.
Innovation Solution
A zoom lens design with a first lens unit having negative refractive power, fixed for zooming, and subsequent lens units that move to adjust the distance between them, adhering to specific inequalities to ensure lightweight and maintain excellent optical performance across the zoom range.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of moving object
If the focal length is set short to acquire entire circumference fisheye image, then the angle of view is improved, but aberrational fluctuations during zooming significantly increase
Solution Approach 1:
The zoom lens is divided into multiple lens units with different functions: a first lens unit with negative refractive power that remains fixed during zooming, and subsequent lens units that move to change magnification. This segmentation allows the negative refractive power portion to stay stationary, stabilizing aberrations while other units adjust for zooming.
Solution Approach 2:
Instead of moving the lens unit with negative refractive power during zooming (conventional approach), this patent inverts the approach by keeping the negative refractive power lens unit fixed and moving other lens units. This reversal stabilizes the retrofocus structure and reduces aberrational fluctuations.
2Weight of moving object
If the movable lens unit weight is reduced for electric driving, then the ease of operation is improved, but the ability to suppress aberrational fluctuations deteriorates
Solution Approach 1:
The lens system is segmented into a fixed first lens unit containing the negative refractive power elements and subsequent movable lens units. This allows the heavy negative lens unit to be stationary (improving aberration stability) while lighter subsequent units are moved electrically (reducing driving weight requirements).
Solution Approach 2:
The subsequent lens units act as intermediaries that perform the zooming function without requiring the heavy first lens unit to move. These intermediary units change the distance between adjacent lens units to achieve magnification variation while keeping the main negative power unit stationary.
3Area of moving object
If the retrofocus type refractive power arrangement is used for super-wide-angle lens, then the angle of view is improved, but the aberrational fluctuations during zooming increase
Solution Approach 1:
The patent inverts the conventional retrofocus zooming approach by keeping the negative refractive power lens unit fixed and moving other lens units. This inversion maintains the retrofocus structure's wide-angle capability while eliminating the harmful effect of moving the negative power elements during zooming.
Solution Approach 2:
The first lens unit with negative refractive power is predetermined to remain fixed during zooming operations. This preliminary designation of the negative power unit as stationary prevents aberrational fluctuations before they occur, while subsequent units are prepared to handle all movement for zooming.
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
The design achieves reduced weight of the movable lens unit and minimizes aberrational fluctuations, providing excellent optical performance throughout the zoom range.
Implementation Method 1
a first lens unit having negative refractive power; and a plurality of subsequent lens units
Data Source
AI summary
A zoom lens includes, in order from an object side to an image side, a first lens unit having negative refractive power, and a plurality of subsequent lens units. The zoom lens further includes an aperture stop. For zooming, the first lens unit is fixed, and the plurality of subsequent lens units move to change a distance between adjacent lens units. Predetermined inequalities are satisfied.