Zoom Lens Extender Unit Segmentation for Compact High-Ratio Design

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Solution Overview

Problem

There is a demand for a zoom lens with a high zooming ratio and high optical performance that is also compact, lightweight, and portable, particularly for outdoor image capturing applications, where the incorporation of an extender lens can increase the effective diameters of lenses, making it difficult to downsize while maintaining high optical performance.

Innovation Solution

The zoom lens design includes a configuration with a first lens unit that does not move for zooming, variator lens units that move for zooming, and an extender lens unit that can be inserted or removed to change the focal length range, with specific inequalities defining the relationships between the effective diameters, transverse magnification, and focal lengths to optimize downsizing and optical performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If an extender lens unit is incorporated to increase the focal length range, then the zooming ratio is improved, but the effective diameters of lenses increase making downsizing difficult

Engineering Contradiction:
Improvezooming ratioVSAvoidlens effective diameter
Core Design Contradiction:
Adaptability or versatilityVSVolume of moving object

Solution Approach 1:

The patent divides the optical system into multiple lens units (first lens unit, second lens unit, third lens unit, and extender lens unit) with distinct functions. The extender lens unit is separated as an independent component that can be inserted or removed, allowing the main lens body to remain compact while achieving extended focal length capability when needed.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements a dynamic configuration where the extender lens unit can be inserted into or removed from the optical path. This dynamic adjustment allows the lens to adapt between a compact state (without extender) and an extended focal length state (with extender), resolving the contradiction between size and zooming ratio.

Inventive Principle:
Principle #15Dynamics

2Area of stationary object

If an extender lens unit is incorporated to achieve a large image circle, then the image circle is improved, but the lens effective diameters increase making the lens larger

Engineering Contradiction:
Improveimage circleVSAvoidlens effective diameter
Core Design Contradiction:
Area of stationary objectVSVolume of moving object

Solution Approach 1:

The patent segments the optical system so that the extender lens unit, which contributes to the large image circle, is separated from the main lens body. This allows the main lens to remain compact while the extender provides the additional optical power needed for large image circle coverage when inserted.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The extender lens unit serves multiple functions: it extends the focal length range and simultaneously enables large image circle coverage. By making this component optional and insertable, the system achieves multi-functionality without permanently increasing the base lens size.

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

3Adaptability or versatility

If an extender lens unit is incorporated to extend focal length range, then the adaptability is improved, but the device complexity increases

Engineering Contradiction:
Improvefocal length rangeVSAvoidlens unit configuration
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent uses a dynamic, insertable extender lens unit that can be added or removed from the optical path. This dynamic configuration allows the system to switch between different focal length ranges without requiring a permanently complex multi-component structure, simplifying the base design while maintaining adaptability.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The extender lens unit is designed to be nested within or integrated with the existing lens unit structure when inserted. This nesting approach allows the extender to combine with the main lens units to form a cohesive optical system, reducing the overall complexity compared to having completely separate systems.

Inventive Principle:
Principle #7Nested doll (Nesting)

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 allows for a zoom lens with a large image circle, high optical performance, and compact size, satisfying various inequalities to ensure effective diameter and transverse magnification ratios, achieving a balance between downsizing and aberration correction.

Implementation Method 1

an extender lens unit to be inserted or removed into or from an optical path between the R1 lens unit and the R2 lens unit for changing a focal length range

Methodology Applied
Scientific EffectLens: Lens

Implementation Method 2

a first relay lens unit R1 and a second relay lens unit R2 that do not move for zooming; In order from an object side to an image side, the first lens unit, the plurality of zooming lens units, the aperture stop, the R1 lens unit, the extender lens unit, and the R2 lens unit

Methodology Applied
Scientific EffectRefraction: Refraction

Data Source

PatentEP3816695B1Zoom lens and image pickup apparatus
Publication Date: 2024.10.23 CANON KK
  • EP3816695B1 patent drawingFigure 1
  • EP3816695B1 patent drawingFigure 2A~2C
  • EP3816695B1 patent drawingFigure 2D~2F

AI summary

A zoom lens including in order from an object side to an image side: a first lens unit (U1) configured not to move for zooming; a plurality of zooming lens units (U2, U3, U4) configured to move in zooming; a front relay lens unit (UR1) configured not to move for zooming; an extender lens unit (UEXT) insertable into and removable from an optical path for changing a focal length range of the zoom lens; and a rear relay lens unit (UR2) configured not to move for zooming, wherein the first lens unit, the plurality of zooming lens units, the front relay lens unit, the extender lens unit and the rear relay lens unit satisfy a specific inequality.