Zoom Lens System with Fixed Intermediate Image Formation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Wide-angle zoom lens systems face challenges in achieving a compact design while maintaining sharp images and minimizing aberrations, particularly in forming intermediate images that do not fluctuate during zooming, which can lead to issues like scratches and dust contamination in the final image.
Innovation Solution
A zoom lens system comprising a fixed first optical system forming an intermediate image and a moving second optical system, where the first optical system includes a negative meniscus lens closest to the object side with a convex surface oriented towards the object side, and the second optical system includes a variator lens group, ensuring the intermediate image position remains fixed during zooming. This configuration allows for a compact design with reduced overall length and simplified zooming mechanisms, effectively correcting chromatic and distortion aberrations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a wide-angle zoom lens system uses a moving first optical system during zooming, then the zooming mechanism is simpler, but the intermediate image position fluctuates causing scratches and dust to appear in the final image
Solution Approach 1:
The lens system is divided into two independent optical systems: a fixed first optical system that forms the intermediate image, and a second optical system that moves during zooming. This segmentation allows the intermediate image position to remain stable while still achieving zoom functionality through the moving second optical system.
2Reliability
If the first optical system is fixed during zooming, then the intermediate image position is stable, but the overall lens system length increases
Solution Approach 1:
The zooming function is achieved by moving the second optical system along the optical axis while keeping the first optical system fixed. This dimensional arrangement allows the intermediate image to remain at a stable position in space, and the compact design is achieved by optimizing the spacing and focal lengths of the two optical systems.
3Device complexity
If the zooming mechanism is concentrated in the first optical system, then the second optical system is simpler, but the intermediate image position fluctuates during zooming
Solution Approach 1:
The fixed first optical system acts as an intermediary that creates a stable intermediate image plane. This intermediate image serves as a stable reference for the second optical system, which then performs the zooming function without affecting the intermediate image position.
4Ease of manufacture
If the back focus of the first optical system is increased, then the intermediate image can be formed more easily, but the overall lens system length increases
Solution Approach 1:
The design optimizes the back focus length of the first optical system and the focal lengths of both optical systems to achieve a balance between ease of intermediate image formation and compact overall length. By carefully selecting these optical parameters, the system achieves both manufacturability and compactness.
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 the creation of a compact, wide-angle zoom lens system capable of forming sharp images across the zoom range without intermediate image fluctuation, reducing the risk of scratches and dust contamination, and effectively correcting aberrations, thus enhancing image quality and system reliability.
Implementation Method 1
a first negative meniscus lens that is disposed closest to the object side and whose convex surface is oriented toward the object side... This lens group guides the light flux that has passed the first meniscus lens across the opposite side to the optical axis and forms an inverted image as an intermediate image
Implementation Method 2
the second optical system includes a variator lens group that moves during zooming... the second optical system includes a variator lens group, ensuring the intermediate image position remains fixed during zooming
Implementation Method 3
the first optical system consists of a fixed lens group that does not move during zooming... Since the first optical system that forms the intermediate image is fixed, it is possible to also fix the formation position (imaging position) of the intermediate image
Data Source
AI summary
A zoom lens system includes: a primary image forming lens group that forms light from an object side into an intermediate image and a relay lens group that forms light from the intermediate image into a final image. The primary image forming lens group includes, in order from the object side, a first fixed lens group G1 with negative refractive power, a stop St, and a second fixed lens group G2 with positive refractive power, and the relay lens group includes, in order from the object side, a third fixed lens group G3 with negative refractive power, a first moving lens group G4 with positive refractive power, and a second moving lens group G5 with positive refractive power.