Camera Body Lens Synchronization for Autofocus Wobbling Control

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Solution Overview

Problem

Existing camera systems lack a method to synchronize the operations between the camera body and interchangeable lens for wobbling control of the focus lens during through-image display or moving-image capture, which is essential for maintaining image focus and quality.

Innovation Solution

A camera system that includes a camera body with a CCD image sensor and a controller generating synchronizing signals to control the interchangeable lens, allowing for wobbling operations of the focus lens at frequencies independent of the exposure synchronizing signal, enabling precise synchronization and autofocus control.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If the camera body and interchangeable lens operate independently without synchronization, then device complexity is reduced, but autofocus precision and image quality deteriorate

Engineering Contradiction:
Improvecontrol system complexityVSAvoidautofocus precision
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent merges the control functions of the camera body and interchangeable lens by introducing a synchronizing signal transmission mechanism. The body controller generates synchronizing signals that are sent to the lens controller, coordinating the operations of both components. This integration ensures that the focus lens wobbling control and image capture operations are synchronized, maintaining autofocus precision while managing system complexity through structured signal-based coordination.

Inventive Principle:
Principle #5Merging (Combining)

2Speed

If the focus lens is controlled to perform wobbling operations at high frequency, then autofocus speed is improved, but power consumption increases

Engineering Contradiction:
Improveautofocus speedVSAvoidpower consumption
Core Design Contradiction:
SpeedVSUse of energy by moving object

Solution Approach 1:

The patent implements periodic wobbling control of the focus lens, where the lens performs minute back-and-forth movements at controlled frequencies. The lens controller receives synchronizing signals from the body controller and executes wobbling operations at appropriate frequencies. This periodic action enables the system to achieve fast autofocus when needed while allowing the lens to remain stationary during stable conditions, thereby reducing overall power consumption.

Inventive Principle:
Principle #19Periodic action

3Reliability

If the camera body continuously sends synchronizing signals to the interchangeable lens, then operational synchronization is improved, but communication overhead and energy consumption increase

Engineering Contradiction:
Improveoperational synchronizationVSAvoidcommunication energy
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The patent establishes continuous synchronizing signal transmission from the body controller to the lens controller during through-image display and moving-image capture operations. This continuous communication ensures reliable operational synchronization, allowing the lens to perform focus lens wobbling control in coordination with the camera body's image capture cycle. The system maintains this continuous synchronization only during active operations, enabling efficient power management by switching to asynchronous mode during idle periods.

Inventive Principle:
Principle #20Continuity of useful action

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

The system effectively controls the wobbling operation of the focus lens at appropriate frequencies, ensuring accurate autofocus and image quality during both through-image display and moving-image capture, while allowing for efficient power management by switching between synchronous and asynchronous modes.

Implementation Method 1

a lens assembly detachably attached to a camera for photo-electrically converting incident light to sense an image and output an image signal

Methodology Applied
Scientific EffectPhotoelectric conversion: Photoelectric Effect

Data Source

PatentEP2290948B1Camera system
Publication Date: 2020.01.22 PANASONIC HOLDINGS CORP
  • EP2290948B1 patent drawingFigure 1
  • EP2290948B1 patent drawingFigure 2
  • EP2290948B1 patent drawingFigure 3(a)~3(d)

AI summary

A camera system includes a camera body (100) and an interchangeable lens (200). The camera body includes an imaging unit that captures a subject image formed by the interchangeable lens in a predetermined capturing cycle to generate image data, a body controller that generates a synchronizing signal having a first cycle correlated with the capturing cycle, and a sending unit that sends the generated synchronizing signal to the interchangeable lens. The body controller further sends information indicating a second cycle different from the first cycle to the interchangeable lens. The interchangeable lens includes a focus lens (230), a drive unit (233) that drives the focus lens along an optical axis, a receiving unit (250) that receives the synchronizing signal and the information indicating the second cycle sent from the camera body, and a lens controller (240) that controls an operation of the interchangeable lens. The lens controller controls the drive unit to perform, in the second cycle, a minute back and forth driving which minutely moves the focus lens back and forth along the optical axis, and performs other control in the first cycle in the interchangeable lens than the control of the minute back and forth driving.