Zoom Lens Focusing Mechanism for Compact Optical Systems
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing zoom image pickup systems for optical instruments, such as endoscopes, microscopes, and binoculars, face challenges in achieving high focusing speed and compactness due to the need for large lens movements and focusing mechanisms, which complicates image size adjustment and increases costs with multiple adapter requirements.
Innovation Solution
A zoom image pickup apparatus with a lens configuration that includes a first positive refractive power lens unit, a second negative refractive power lens unit as the focusing lens, and a third positive refractive power lens unit, where the third and fourth lens units move during zooming, and the second lens unit moves during focusing, optimizing focusing sensitivity and reducing aberration fluctuations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a zooming optical system is used to adjust image size, then the user can achieve desired image size, but a focusing mechanism becomes necessary when diopter scales differ, increasing device complexity
Solution Approach 1:
The second lens unit serves dual functions: it acts as a negative lens unit in the zooming optical system and simultaneously functions as a focusing lens unit. This multi-functionality eliminates the need for a separate focusing mechanism, resolving the technical contradiction between adaptability and device complexity
Solution Approach 2:
The patent combines the focusing function with the negative lens unit of the zooming system by setting the second lens unit as both. This merging of functions reduces the number of components and eliminates the need for additional focusing mechanisms when diopter scales differ
2Ease of operation
If the whole zooming optical system is moved for focusing, then focusing can be achieved, but the optical system and overall image pickup apparatus become large
Solution Approach 1:
The patent segments the focusing function from the entire zooming optical system and assigns it specifically to the second lens unit. This segmentation allows only a portion of the system to move during focusing, reducing the overall size and mass that needs to be moved compared to moving the entire zooming system
3Ease of operation
If a zooming optical system with focusing mechanism is provided, then focusing can be achieved, but the number of parts increases and cost becomes high
Solution Approach 1:
The second lens unit is designed to serve multiple purposes: it functions as part of the zooming optical system and simultaneously as the focusing lens unit. This multi-functionality reduces the total number of parts by eliminating the need for separate focusing mechanisms
Solution Approach 2:
The patent merges the focusing function with the existing negative lens unit (second lens unit) of the zooming system. This combination reduces the number of components and simplifies the overall structure, lowering cost and complexity
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 enhances focusing speed, reduces lens movement, and minimizes aberration fluctuations, allowing for precise image size adjustment and compact system design while maintaining high optical performance.
Implementation Method 1
a first lens unit having a positive refractive power, a second lens unit having a negative refractive power, a third lens unit having a positive refractive power
Data Source
AI summary
A zoom image pickup apparatus includes a mount portion, a zoom lens which forms an image of light incident from the mount portion, and an image pickup element which is disposed at an image forming position. The zoom lens includes in order from an image side, a first lens unit having a positive refractive power, a second lens unit having a negative refractive power, a third lens unit having a positive refractive power, and a lens unit having a negative refractive power. The second lens unit is a focusing lens unit. At the time of zooming from a wide angle end to a telephoto end, the third lens unit and the lens unit having a negative refractive power positioned on an object side of the third lens unit move, and the following conditional expression (1) is satisfied:ϕL1<ϕ3GL1 (1).