Zoom Lens Rear Unit Blur Compensation and Focusing

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Solution Overview

Problem

Existing zoom lens systems face challenges in achieving size and weight reduction while maintaining high image formation performance and blur compensation functionality, as they often require a large number of lens elements and increased driving force for blur compensation, leading to increased size and weight.

Innovation Solution

A zoom lens system comprising a front lens unit with negative optical power and a rear lens unit divided into two sub-units, where the rear A lens unit moves perpendicular to the optical axis for blur compensation and the rear B lens unit moves along the optical axis to adjust focusing, allowing for reduced lens element count and simplified construction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a large number of lens elements are used to compensate aberration in each lens unit for achieving blur compensation function, then image formation performance is improved, but size and weight of the lens system increase

Engineering Contradiction:

Improveimage formation performanceVSAvoidweight of lens system

Core Design Contradiction:

ReliabilityVSWeight of moving object

Solution Approach 1:

The lens system is divided into multiple lens units (first lens unit with positive power, second lens unit with negative power, third lens unit with positive power, and fourth lens unit with positive power). Each lens unit is optimized to contribute to overall aberration compensation, allowing the system to achieve high image formation performance without requiring excessive elements in any single unit. The segmentation enables distributed aberration control throughout the optical path.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The lens units are designed to serve multiple functions simultaneously. For example, the third lens unit serves both as a zooming element (changing intervals with other lens units to vary magnification) and as a blur compensation element (moving perpendicular to the optical axis). This multi-functionality reduces the total number of lens elements needed while maintaining both zoom and blur compensation capabilities.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Reliability

If driving force of blur compensation actuator is increased to move heavy blur compensation lens unit, then blur compensation function is improved, but volume of actuator and overall device size increase

Engineering Contradiction:

Improveblur compensation functionVSAvoidvolume of actuator

Core Design Contradiction:

ReliabilityVSVolume of moving object

Solution Approach 1:

The blur compensation function is assigned to a specific lens unit (the third lens unit) rather than requiring all lens units to be heavy and capable of blur compensation. By segmenting the blur compensation task to a single, optimized lens unit with fewer elements, the mass requiring actuation is reduced, allowing for a smaller, lighter actuator.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The optical power distribution among lens units is optimized so that the blur compensation lens unit (third lens unit) has appropriate optical characteristics that reduce its effective mass and movement requirements. By adjusting the optical parameters (focal lengths, positions) of individual lens units, the system achieves effective blur compensation with reduced actuator force and volume requirements.

Inventive Principle:

Principle #35Parameter changes

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 achieves size and weight reduction while maintaining high image formation performance and blur compensation functionality, enabling a compact and lightweight imaging optical device with improved aberration compensation.

Implementation Method 1

drive control is performed such that at least a part of the lens system is moved in a direction perpendicular to the optical axis so as to deflect the shooting view angle such as to cancel the deflection of the shooting view angle caused by blur

Methodology Applied

Scientific EffectBlur compensation through lens unit movement:

Implementation Method 2

focusing adjustment during variation of the object distance is achieved by changing the interval between the rear A lens unit and the rear B lens unit

Methodology Applied

Scientific EffectFocusing adjustment through lens unit movement:

Implementation Method 3

magnification change is performed by changing an interval between the individual lens units

Methodology Applied

Scientific EffectMagnification change through interval adjustment:

Data Source

PatentUS7724447B2Zoom lens system and imaging optical device employing the same

Publication Date: 2010.05.25 PANASONIC HOLDINGS CORP

AI summary

The present zoom lens system comprises a plurality of lens units including at least: a front lens unit having negative optical power; and a rear lens unit having positive optical power, arranged on the image side of the front lens unit, and composed of a plurality of lens elements; wherein magnification change is performed by changing an interval between the individual lens units, wherein the rear lens unit comprises: a rear A lens unit capable of moving in a direction perpendicular to an optical axis; and a rear B lens unit that is arranged on the image side of the rear A lens unit and that can move in an optical axis direction in such a manner that an interval relative to the rear A lens unit in the optical axis direction is changed, and wherein focusing adjustment during variation of the object distance is achieved by changing the interval between the rear A lens unit and the rear B lens unit.