Imaging Apparatus Communication Control for Interchangeable Lens

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Solution Overview

Problem

Existing camera systems face communication delays and potential breakdowns due to the need for time management in switching communication masters between the camera main body and interchangeable lens, which can lead to collisions and increased power consumption when adding new channels is not feasible.

Innovation Solution

The system switches between communication modes to optimize data exchange by allowing or forbidding BUSY signals, enabling high-speed data transfer without adding new channels by using existing communication channels efficiently.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the communication master is switched by time management between the camera main body and the interchangeable lens, then communication collision is prevented, but communication delay increases due to communication-invalid time

Engineering Contradiction:

Improvecommunication reliabilityVSAvoidcommunication delay

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent eliminates communication-invalid time by allowing continuous data transmission from the interchangeable lens to the camera main body without stopping the clock signal. The lens continuously outputs data while the camera main body controls reception timing, enabling uninterrupted communication and eliminating the time loss associated with master switching.

Inventive Principle:

Principle #20Continuity of useful action

Solution Approach 2:

The patent inverts the traditional master-slave relationship by making the interchangeable lens the active data source that continuously transmits data, while the camera main body becomes the controlled receiver. This inversion allows the lens to maintain continuous transmission without being constrained by master switching timing.

Inventive Principle:

Principle #13The other way round (Inversion)

2Ease of operation

If a new channel is added for communication standby request signals, then communication control is improved, but electric power consumption increases

Engineering Contradiction:

Improvecommunication controlVSAvoidelectric power consumption

Core Design Contradiction:

Ease of operationVSUse of energy by moving object

Solution Approach 1:

The patent makes the clock signal channel multi-functional by using it for both clock synchronization and data transmission from the interchangeable lens to the camera main body. This eliminates the need for a separate communication standby request channel, reducing the number of channels while maintaining effective communication control.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent merges the clock signal channel and the data transmission channel into a single channel. The clock signal serves dual purposes: providing synchronization timing and carrying data from the lens to the camera main body, thereby consolidating multiple functions into one channel and reducing power consumption.

Inventive Principle:

Principle #5Merging (Combining)

3Loss of information

If data amount increases for advanced imaging technology, then imaging quality is improved, but communication speed requirement increases

Engineering Contradiction:

Improvelens information data amountVSAvoidcommunication speed

Core Design Contradiction:

Loss of informationVSSpeed

Solution Approach 1:

The patent enables continuous data transmission from the interchangeable lens to the camera main body without interruption for master switching. This continuous transmission mode allows large amounts of lens information data to be communicated efficiently at high speeds, meeting the requirements of advanced imaging technology.

Inventive Principle:

Principle #20Continuity of useful action

4Reliability

If communication master switching is implemented, then communication collision is prevented, but device complexity increases

Engineering Contradiction:

Improvecommunication reliabilityVSAvoidcommunication system complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent simplifies the communication system by inverting the traditional master-slave architecture. Instead of the camera main body controlling all communication timing as master, the interchangeable lens becomes the active transmitter with continuous data output, while the camera main body controls reception. This inversion reduces the complexity of master switching mechanisms.

Inventive Principle:

Principle #13The other way round (Inversion)

Data Source

PatentEP3438738B1Accessory device, imaging device, and communication control program

Publication Date: 2023.06.28 CANON KK

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AI summary

An imaging apparatus 200 that provides, between itself and an accessory device 100, a notification channel used for notification from the imaging apparatus to the accessory device, a first data communication channel used in data transmission from the accessory device to the imaging apparatus, and a second data communication channel used in data transmission from the imaging apparatus to the accessory device. An accessory control unit 111 transmits data via the first data communication channel in response to having received a transmission request signal via the notification channel, and selectively adds, to the data, a communication standby request for keeping a transmission request signal from being transmitted from the imaging apparatus to the accessory device.