Interchangeable Lens Autofocus Control via Driving Method Information

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Solution Overview

Problem

Existing camera systems cannot precisely control interchangeable lenses during autofocus operations, as they lack information on the driving methods supported by the lens, leading to potential malfunctions when unsupported driving methods are instructed.

Innovation Solution

The camera body obtains and stores driving method information from the interchangeable lens, allowing it to determine and use only supported autofocus control methods, preventing malfunctions by avoiding unsupported driving methods.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the camera body performs autofocus control without obtaining driving method information from the interchangeable lens, then the autofocus operation can be executed, but the lens unit cannot be precisely controlled and may malfunction when unsupported driving methods are instructed

Engineering Contradiction:
Improveautofocus control reliabilityVSAvoiddriving method information
Core Design Contradiction:
ReliabilityVSLoss of information

Solution Approach 1:

The camera body obtains driving method information from the interchangeable lens before executing autofocus control. This preliminary acquisition of information allows the camera to determine supported driving methods in advance, ensuring that only compatible autofocus operations are instructed to the lens unit, thereby preventing malfunctions and improving control reliability

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The camera body receives feedback from the interchangeable lens in the form of driving method information that indicates which driving methods are supported. This feedback mechanism enables the camera to adjust its autofocus control strategy based on the actual capabilities of the attached lens, ensuring precise and reliable control without attempting unsupported operations

Inventive Principle:
Principle #23Feedback

2Measurement precision

If the camera body obtains and stores driving method information from the interchangeable lens, then precise control during autofocus operations is enabled, but additional communication and processing steps are required

Engineering Contradiction:
Improvefocus control precisionVSAvoidcontrol system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The camera body is designed with universal compatibility to work with multiple types of interchangeable lenses. By obtaining driving method information from the lens, the camera can adapt its control approach to match the specific capabilities of each lens type, enabling precise control across diverse lens configurations without requiring complex lens-specific control circuits

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

Solution Approach 2:

Driving method information acts as an intermediary between the camera body and the interchangeable lens. This information layer enables the camera to understand lens capabilities and adjust its control commands accordingly, achieving precise focus control without direct complex interaction between the camera's control circuit and the lens's driving mechanism

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP2270571B1Interchangeable lens, camera body, and camera system
Publication Date: 2017.05.31 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD
  • EP2270571B1 patent drawingFigure 1
  • EP2270571B1 patent drawingFigure 2A~2C
  • EP2270571B1 patent drawingFigure 3

AI summary

An interchangeable lens includes a drive unit (233) that drives a focus lens (230) back and forth along an optical axis, a storage unit (242) that stores driving method information indicating a driving method for autofocus control which is supported by the interchangeable lens, a sending unit (240) that sends the driving method information to the camera body, and a lens controller (240) that controls an operation of the interchangeable lens. A camera body (100, 140) determines control on the interchangeable lens by referring to the driving method information obtained from the interchangeable lens to generate a control signal. The lens controller (240) of the interchangeable lens controls the drive unit according to the driving method instructed by the control information received from the camera body, when autofocus control is performed.