Variable Power Optical System Aberration Control

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional variable magnification optical systems face challenges in achieving high optical performance due to difficulties in correcting aberrations caused by varying magnification and focusing.

Innovation Solution

The proposed variable magnification optical system comprises a configuration with a first lens group, an intermediate lens group, a first focusing lens group, and a rear lens group, where the lens groups are moved along specific trajectories and intervals to satisfy certain focal length ratios, incorporating at least one intermediate lens group with negative refractive power, which helps in correcting aberrations and achieving high optical performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional variable magnification optical systems are used, then the basic zoom function is achieved, but high optical performance cannot be attained due to aberration variations

Engineering Contradiction:
Improveoptical performanceVSAvoidaberration variations
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The optical system is divided into multiple lens groups (first lens group, first focusing lens group, second focusing lens group, rear lens group) with distinct functions. The focusing lens groups are further segmented to move along different trajectories, allowing independent correction of aberrations at different stages of light propagation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different lens groups are assigned specific refractive power characteristics (positive or negative) and movement patterns tailored to their local optical function. The intermediate lens group with negative refractive power is strategically positioned to correct specific aberrations, while focusing lens groups have different movement trajectories optimized for their respective focal lengths.

Inventive Principle:
Principle #3Local quality

Solution Approach 3:

The optical system employs dynamic movement of lens groups during both zooming and focusing operations. The first lens group moves to vary magnification, while the focusing lens groups move along different trajectories to dynamically correct aberrations. The intervals between lens groups are continuously adjusted to maintain optimal optical performance across varying magnification states.

Inventive Principle:
Principle #15Dynamics

2Reliability

If multiple lens groups are added to correct aberrations, then optical performance improves, but device complexity increases

Engineering Contradiction:
Improveoptical performanceVSAvoidlens group configuration
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The lens groups serve multiple functions: the first lens group contributes to both zooming and aberration correction, the focusing lens groups simultaneously perform focusing and aberration compensation, and the rear lens group aids in both image formation and aberration control. This multi-functionality reduces the need for additional dedicated correction elements.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The zooming function and aberration correction function are merged into the same lens group movements. The focusing lens groups that move along different trajectories simultaneously achieve focusing and aberration correction, eliminating the need for separate correction mechanisms.

Inventive Principle:
Principle #5Merging (Combining)

3Reliability

If lens groups are moved along different trajectories for focusing, then aberration correction improves, but manufacturing precision requirements increase

Engineering Contradiction:
Improveaberration correctionVSAvoidtrajectory control
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The different trajectories of the focusing lens groups follow curved paths rather than straight lines, allowing for smoother transitions and more gradual changes in optical parameters. This curved movement pattern reduces the abruptness of trajectory changes, thereby lowering the precision requirements for mechanical control while maintaining effective aberration correction.

Inventive Principle:
Principle #14Spheroidality (Curvature)

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 effectively suppresses variations in aberrations across different magnification states and focal lengths, resulting in a high optical performance and compact lens barrel design.

Implementation Method 1

at least one intermediate lens group (Gm) having negative refractive power between said first lens group (G1) and said first focusing lens group (Ga)

Methodology Applied
Scientific EffectRefraction: Refraction

Data Source

PatentEP3176625B1Variable power optical system, optical device, and manufacturing method for variable power optical system
Publication Date: 2019.09.25 NIKON CORP
  • EP3176625B1 patent drawingFigure 1
  • EP3176625B1 patent drawingFigure 2A~2B
  • EP3176625B1 patent drawingFigure 3A~3B

AI summary

A variable magnification optical system of the present application comprises a first lens group (G1) disposed at a most object side, a first focusing lens group (Ga) disposed at an image side of the first lens group, a second focusing lens group (Gb) disposed at an image side of the first focusing lens group, and a rear lens group (Gr) disposed at an image side of the second focusing lens group; upon varying magnification, the first lens group being moved, and an interval between the first lens group and the first focusing lens group, an interval between the first focusing lens group and the second focusing lens group, and an interval between the second focusing lens group and the rear lens group being varied; upon focusing, the first focusing lens group and the second focusing lens group being moved along the optical axis with different trajectories from each other; and a given conditional expression being satisfied.