Zoom Lens Intermediate Image Re-imaging Wide Angle Small F Number
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Solution Overview
Problem
Existing zoom lenses for projection display devices have limitations in terms of angle of view and F number, failing to provide high optical performance with a wide angle and small F number.
Innovation Solution
A zoom lens configuration that forms an intermediate image and re-images it, comprising a 4-group optical system with specific refractive power distributions and movements during zooming, ensuring a wide angle and small F number while maintaining high optical performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional optical systems with intermediate image formation are used, then zooming function is achieved, but angle of view and F number are insufficient
Solution Approach 1:
The optical system is divided into multiple lens groups (first through fourth lens groups) with specific refractive powers. The second optical system contains four lens groups arranged in sequence, where the second and third lens groups move during zooming while the fourth lens group remains stationary. This segmentation allows independent optimization of each group's function to achieve both wide angle and small F number simultaneously.
Solution Approach 2:
The patent implements dynamic movement of specific lens groups during zooming operations. The second and third lens groups change their positions relative to each other and to the stationary fourth lens group, enabling the system to adjust focal length while maintaining optimal optical performance across the zoom range, achieving both wide angle capability and small F number.
2Adaptability or versatility
If conventional optical systems are used, then zooming function is achieved, but angle of view is limited
Solution Approach 1:
The optical system is segmented into multiple lens groups with specific refractive powers. The second optical system contains four lens groups where the second group has positive refractive power and the third group has positive or negative refractive power. This segmentation enables the system to achieve wide angle of view while maintaining zooming functionality through coordinated movement of these groups.
Solution Approach 2:
Different lens groups are assigned specific refractive powers and movement characteristics optimized for their local function. The fourth lens group remains stationary with positive refractive power to provide stable image formation, while the second and third lens groups move to enable zooming and wide angle coverage, allowing each part to contribute optimally to the overall performance.
3Reliability
If existing zoom lens configurations are used, then basic imaging is achieved, but optical performance with wide angle and small F number is not attained
Solution Approach 1:
The optical system is divided into first and second optical systems, with the second optical system containing four specifically configured lens groups. This segmentation allows precise control over aberration correction and image quality while maintaining reliable imaging function across the zoom range with wide angle and small F number.
Solution Approach 2:
The patent specifies particular refractive power relationships and movement parameters for each lens group. The fourth lens group maintains positive refractive power and remains stationary, while the second and third lens groups move with specific displacement relationships. These parameter optimizations ensure high optical performance is achieved reliably across the entire 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 achieves a wide angle with a small F number, effectively correcting aberrations and ensuring high optical performance, suitable for projection display devices and imaging applications.
Implementation Method 1
a second optical system closer to the reduction side than the intermediate image, the second optical system including, in order from the magnification side, a first lens group having a positive refractive power, a second lens group having a positive refractive power, a third lens group having a positive or negative refractive power, and a fourth lens group having a positive refractive power
Data Source
AI summary
In the zoom lens, a first optical system is formed on the magnification side, and a second optical system is formed on the reduction side, with the intermediate image formed between the first optical system and the second optical system. The second optical system consists of, in order from the magnification side, a first lens group that has a positive power, a second lens group that has a positive power, a third lens group that has a positive or negative power, and a fourth lens group that has a positive power. During zooming, the second lens group and the third lens group are moved by changing spacings between the groups adjacent to each other in a direction of an optical axis, and the fourth lens group remains stationary with respect to the reduction side imaging plane.