Lens Apparatus Backlash Control Single Biasing Member

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Solution Overview

Problem

Existing lens apparatuses require two sets of biasing members to control backlash, increasing size and complexity when a lens barrel inside another is hung using a roller, necessitating control of backlash between the cam follower and the cam groove, as well as the roller and the base barrel.

Innovation Solution

A lens apparatus configuration that includes a lens holding member, a first movement member, a guide member with a straight groove, a cam member with a cam groove, and a biasing member to bias the cam follower into the straight and cam grooves, allowing for relative rotation and movement in the optical-axis direction, thereby controlling backlash with a single set of biasing members.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If two sets of biasing members are used to control backlash between the cam follower and cam groove, as well as the roller and base barrel, then backlash control is improved, but the size and complexity of the lens apparatus increases

Engineering Contradiction:

Improvebacklash controlVSAvoidnumber of biasing members

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines the functions of two separate biasing members into a single biasing member. This single biasing member simultaneously biases the cam follower against the cam groove and controls backlash in the roller-base barrel interface, thereby reducing component count while maintaining effective backlash control for both engagement points

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The single biasing member is designed to perform multiple functions: it provides biasing force for the cam follower-cam groove engagement while also controlling backlash for the roller-base barrel engagement. This multi-functional design eliminates the need for separate biasing members for each interface

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Manufacturing precision

If two sets of biasing members are used to control backlash, then precision of movement is improved, but the lens apparatus size increases

Engineering Contradiction:

Improvemovement precisionVSAvoidlens apparatus size

Core Design Contradiction:

Manufacturing precisionVSVolume of moving object

Solution Approach 1:

By merging the backlash control functions into a single biasing member, the patent reduces the overall volume occupied by biasing components while maintaining the precision required for both cam follower and roller engagements. The compact design of the unified biasing mechanism prevents excessive lens apparatus size increase

Inventive Principle:

Principle #5Merging (Combining)

3Adaptability or versatility

If a lens barrel inside another is hung using a roller, then adaptability is improved, but backlash control complexity increases

Engineering Contradiction:

Improvelens barrel configuration flexibilityVSAvoidbacklash control mechanism

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The single biasing member is designed to handle multiple engagement scenarios simultaneously - it provides biasing for the cam follower-cam groove interface while also controlling backlash in the roller-base barrel interface. This universal approach maintains adaptability for nested lens barrel configurations without increasing control mechanism complexity

Inventive Principle:

Principle #6Universality (Multi-functionality)

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 controls backlash between the lens holding member and the guide member, reducing the size and complexity of the lens apparatus while maintaining precise optical-axis movement, enhancing the stability and durability of the lens system.

Implementation Method 1

a biasing member configured to bias the lens holding member to the second movement member so that the cam follower is biased to the straight groove and the cam groove

Methodology Applied

Scientific EffectElasticity: Elasticity

Data Source

PatentUS20230314758A1Lens apparatus and imaging apparatus

Publication Date: 2023.10.05 CANON KK

AI summary

A lens apparatus includes a lens holding member holding a lens, a first movement member, a guide member having a straight groove, a second movement member, a biasing member, and a cam member that has a cam groove and rotates relative to the guide member. The first movement member holds the lens holding member and moves in an optical-axis direction together with the lens holding member. The first movement member includes a cam follower that engages with the straight groove and the cam groove and that moves in the optical-axis direction by relative rotation of the cam member to the guide member. The second movement member moves in the optical-axis direction together with the lens holding member and the first movement member. The biasing member biases the lens holding member to the second movement member so that the cam follower is biased to the straight groove and the cam groove.