Compact Zoom Lens System with Inverted Power Arrangement
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Solution Overview
Problem
Conventional zoom lens systems with negative lens units closest to the object side face challenges in reducing overall length while maintaining optical performance, making it difficult to achieve compact and lightweight designs.
Innovation Solution
A zoom lens system comprising a first lens unit with negative optical power, a second lens unit with positive optical power, a third lens unit with negative optical power, and a fourth lens unit with positive optical power, where the first lens unit moves along the optical axis, and the fourth lens unit is fixed relative to the image surface, satisfying the condition 0.8 < |f1/fW| < 1.4, allowing for a compact and lightweight design with excellent optical performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a negative lens unit is located closest to the object side in a zoom lens system, then optical performance is maintained, but the overall length of the lens system increases
Solution Approach 1:
The patent inverts the conventional arrangement by placing a positive lens unit closest to the object side instead of a negative lens unit. This reversal of the traditional negative-positive-negative-positive sequence enables compact design while maintaining optical performance through the specific four-unit construction and movement mechanism where the first and third units move together and the second and fourth units move together during zooming.
2Reliability
If multiple lens units are used to achieve variable magnification, then optical performance is improved, but device complexity increases
Solution Approach 1:
The patent employs dynamic movement of lens units during zooming, where the first and third lens units move together along the optical axis, and the second and fourth lens units move together. This coordinated dynamic movement enables variable magnification with a compact four-unit construction, reducing complexity compared to conventional multi-unit systems while maintaining excellent optical performance across the zoom range.
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 solution enables a compact and lightweight zoom lens system with reduced overall length, improved optical performance, and effective image blur compensation, while preventing dust entry and simplifying the lens barrel configuration.
Implementation Method 1
a first lens unit having negative optical power, a second lens unit having positive optical power, a third lens unit having negative optical power, and a fourth lens unit having positive optical power
Implementation Method 2
the fourth lens unit is fixed relative to an image surface, in zooming from a wide-angle limit to a telephoto limit
Data Source
AI summary
A zoom lens system, in order from an object side to an image side, comprising a first lens unit having negative optical power, a second lens unit having positive optical power, a third lens unit having negative optical power, and a fourth lens unit having positive optical power, wherein the first lens unit moves along an optical axis, and the fourth lens unit is fixed relative to an image surface, in zooming from a wide-angle limit to a telephoto limit at the time of image taking, and the condition: 0.8<|f1/fW|<1.4 (f1: a composite focal length of the first lens unit, fW: a focal length of the entire system at a wide-angle limit) is satisfied; an interchangeable lens apparatus; and a camera system are provided.