Optical Image Stabilization Sensitivity Control for Walking

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Solution Overview

Problem

Conventional optical image stabilization methods fail to provide satisfactory image stabilization during walking shooting due to frequent changes in object distance and sensitivity, leading to unstable correction amounts for the correction lens, especially on the wide side of the lens system where the depth of field is large and focus lens positions are dense, resulting in low precision object distance detection and frequent sensitivity variations.

Innovation Solution

An optical apparatus with a correction optical system that includes a zoom lens, focus lens, focal length detection, object distance detection, shake detection, and a sensitivity generation unit that limits object distance or focal length to stabilize sensitivity when walking shooting is determined, allowing for precise calculation and control of the correction amount for the shift lens to maintain image stabilization.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If object distance is detected from focus lens position on the wide side, then object distance detection is performed, but precision of object distance detection becomes low due to dense focus lens positions

Engineering Contradiction:

Improveobject distance detection precisionVSAvoidfocus lens position density

Core Design Contradiction:

Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The patent changes the parameter used for object distance detection from focus lens position to zoom lens position. This parameter substitution resolves the precision problem because zoom lens position has a more stable relationship with object distance, especially on the wide side where focus lens positions are densely packed and provide poor detection precision.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent introduces zoom lens position as an intermediary parameter to indirectly determine object distance. Instead of directly using focus lens position (which has poor precision on the wide side), the system uses zoom lens position as a mediator that provides more reliable object distance information.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Adaptability or versatility

If sensitivity is calculated based on frequent object distance changes during walking shooting, then sensitivity varies frequently, but this causes unstable correction amounts for the correction lens

Engineering Contradiction:

Improvesensitivity adjustment responsivenessVSAvoidcorrection amount stability

Core Design Contradiction:

Adaptability or versatilityVSStability of the object's composition

Solution Approach 1:

The patent changes the basis for sensitivity calculation from object distance (which varies frequently during walking shooting) to focal length (which is more stable). This parameter substitution reduces unnecessary sensitivity variations while maintaining the necessary adaptability for different shooting conditions.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

Instead of calculating sensitivity based on object distance changes (the conventional approach that causes instability), the patent inverts the approach by calculating sensitivity based on focal length. This inversion resolves the contradiction by using a more stable parameter while still maintaining adaptability through the focal length-sensitivity relationship.

Inventive Principle:

Principle #13The other way round (Inversion)

3Ease of operation

If focus lens position is frequently adjusted during walking shooting, then focus adjustment is maintained, but object distance detection precision deteriorates due to large changes in object distance

Engineering Contradiction:

Improvefocus adjustment capabilityVSAvoidobject distance detection precision

Core Design Contradiction:

Ease of operationVSMeasurement precision

Solution Approach 1:

The patent uses zoom lens position as an intermediary parameter to detect object distance, independent of focus lens position adjustments. This allows focus adjustment to proceed freely for ease of operation while object distance detection maintains precision through the stable zoom lens position parameter.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent separates the functions of focus adjustment and object distance detection. Focus lens position is used solely for focus adjustment (maintaining ease of operation), while zoom lens position is used for object distance detection (maintaining precision). This functional segmentation resolves the contradiction between the two requirements.

Inventive Principle:

Principle #1Segmentation

Data Source

PatentUS9170429B2Optical apparatus and image capturing apparatus, and method of controlling the same and storage medium

Publication Date: 2015.10.27 CANON KK

AI summary

An optical apparatus includes an imaging optical system, an image capturing unit, a focal length detection unit, an object distance detection unit, a walking shooting determination unit, a sensitivity generation unit configured to generate sensitivity of the correction optical system, a correction amount calculation unit configured to calculate a correction amount of the correction optical system based on the shake amount and the sensitivity, and a control unit configured to drive the correction optical system based on the correction amount. The sensitivity generation unit generates the sensitivity by limiting the object distance or the focal length, or a range of the sensitivity when it is determined that the user of an image capturing apparatus is walking.