Six-Group Zoom Lens for Compact High-Brightness Imaging
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Solution Overview
Problem
Conventional zoom lenses for film making and broadcasting cameras face challenges in achieving high performance with small F-numbers and compactness, particularly under low illumination conditions, while maintaining image quality and preventing size increases.
Innovation Solution
A zoom lens system comprising six lens groups with specific refractive power arrangements and movements, including fixed and movable groups, to achieve a small F-number and improved performance without increasing the lens system's size, with conditional expressions governing the distances and focal lengths between lens groups.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If the number of lenses is increased to achieve higher performance and smaller F-number, then imaging performance and brightness are improved, but the size of the apparatus increases
Solution Approach 1:
The zoom lens is divided into six lens groups with specific refractive power arrangements (positive, negative, negative, negative, positive, positive). This segmentation allows for better control of light paths and aberrations, enabling smaller F-numbers without proportionally increasing the overall apparatus size.
Solution Approach 2:
During magnification change from wide angle to telephoto end, specific distances between lens groups are dynamically adjusted: the distance between the first and second lens groups increases, while distances between other lens groups change. This dynamic adjustment optimizes the optical path to maintain small F-numbers across different focal lengths without requiring a proportional increase in apparatus size.
2Reliability
If more lens groups are added to improve imaging performance, then image quality is enhanced, but the complexity of the lens system increases
Solution Approach 1:
The lens system is segmented into six distinct lens groups with specific refractive power signs arranged in a particular sequence (positive, negative, negative, negative, positive, positive). This segmentation enables sophisticated aberration correction and high image quality while maintaining a manageable structural complexity through systematic arrangement.
Solution Approach 2:
The lens system employs dynamic movement of lens groups during magnification change. Specifically, the distance between the first and second lens groups increases, while other inter-group distances change, allowing the system to adapt its configuration to maintain optimal performance across different focal lengths without requiring excessive complexity.
3Volume of moving object
If the lens system is made compact for portability, then ease of carrying is improved, but achieving small F-number and high performance becomes difficult
Solution Approach 1:
The compact zoom lens achieves small F-numbers through dynamic adjustment of inter-lens-group distances during magnification change. The distance between the first and second lens groups increases from wide to telephoto end, while other distances change accordingly, optimizing the optical path length and light gathering capability within a compact form factor.
Solution Approach 2:
The lens system utilizes changes in refractive power distribution across six lens groups and dynamic adjustment of distances between them to maintain small F-numbers. By carefully controlling the signs and magnitudes of refractive powers and their spatial relationships, the system achieves high performance in a compact configuration.
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 allows for high-quality imaging under low illumination conditions while maintaining compactness and suppressing aberration fluctuations during magnification changes, achieving a high zoom ratio and excellent aberration correction.
Implementation Method 1
a zoom lens consists essentially of six lens groups of, in order from the object side, a first lens group having positive refractive power, a second lens group having negative refractive power, a third lens group having negative refractive power, a fourth lens group having negative refractive power, a fifth lens group having positive refractive power, and a sixth lens group having positive refractive power
Data Source
AI summary
A zoom lens consists of, in order from the object side, a positive first lens group, a negative second lens group, a negative third lens group, a negative fourth lens group, a positive fifth lens group, and a positive sixth lens group. The first lens group and the sixth lens group are fixed with respect to an image plane, and a distance between the first lens group and the second lens group increases, a distance between the second lens group and the third lens group changes, and a distance between the third lens group and the fourth lens group changes, and a distance between the fourth lens group and the fifth lens group changes, and a distance between the fifth lens group and the sixth lens group changes during magnification change from a wide angle end to a telephoto end.