Bayonet Mount Optical Axis Alignment via Intermediary Pin

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Solution Overview

Problem

Existing imaging apparatuses face challenges in securely mounting interchangeable lenses due to dimensional tolerance gaps and weight-induced looseness, leading to potential deviations in optical axis alignment and unnatural image capture.

Innovation Solution

The implementation of a bayonet coupling mechanism with specifically angled bayonet claws and recesses on both the camera and lens mounts, ensuring precise alignment and reducing looseness by overlapping certain claws and recesses to prevent incorrect mounting and enhance mechanical stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If bayonet coupling is used to mount interchangeable lenses, then ease of operation is improved, but dimensional tolerance gaps cause looseness and optical axis deviation

Engineering Contradiction:
Improveease of mountingVSAvoidoptical axis alignment
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

A mounting pin acts as an intermediary element that protrudes from the camera body and inserts into a recess in the lens mount. This pin serves as a precise reference that defines the optical axis position, mediating between the camera body and lens to eliminate alignment errors caused by dimensional tolerances in the bayonet coupling surfaces.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The mounting pin is positioned in advance on the camera body at the precise location where the optical axis should be. Before the lens is fully mounted and locked by the bayonet coupling, the pin is already in place to guide and constrain the lens mount, ensuring correct optical axis alignment from the outset of the mounting process.

Inventive Principle:
Principle #10Preliminary action

2Ease of operation

If bayonet coupling is used for lens mounting, then ease of operation is improved, but weight-induced looseness occurs

Engineering Contradiction:
Improveease of mountingVSAvoidmounting stability
Core Design Contradiction:
Ease of operationVSStability of the object's composition

Solution Approach 1:

The mounting pin serves as a stable intermediary that transfers and distributes the mechanical load from the lens weight. By inserting the lens mount recess over the rigid mounting pin, the pin acts as a load-bearing reference that prevents the mounting interface from loosening under the influence of lens weight during camera operation.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Adaptability or versatility

If multiple contacts are provided for power and communication, then adaptability is improved, but device complexity increases

Engineering Contradiction:
Improvecommunication capabilityVSAvoidnumber of contacts
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The mounting pin serves multiple functions: it acts as a mechanical reference for optical axis alignment, a positioning element for the bayonet coupling, and a load-bearing support. This multi-functionality reduces the need for separate components, thereby reducing overall device complexity while maintaining adaptability for power and communication contacts.

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

Data Source

PatentEP3936938A1Imaging apparatus and accessory
Publication Date: 2022.01.12 CANON KK
  • EP3936938A1 patent drawingFigure 1A
  • EP3936938A1 patent drawingFigure 1B
  • EP3936938A1 patent drawingFigure 2A~2B

AI summary

A mount apparatus comprises a second mount arranged to couple with a first mount provided to an accessory; a plurality of claws arranged to be able to engage with a plurality of claws of the accessory; and a plurality of contact pins disposed following a circumferential direction of the second mount, and arranged for electrical connection with a plurality of contact faces disposed following a circumferential direction of the first mount of the accessory. The mount apparatus is arranged to be relatively rotatable as to the accessory, between a first state where the claws of the mount apparatus are each inserted between each of the plurality of claws of the accessory, and a second state where the plurality of claws of the mount apparatus are each engaged with corresponding one of the claws of the accessory in a center axis direction of the second mount. The plurality of contact pins includes a first contact pin which is arranged to come into contact first with the plurality of contact faces, during relative rotation of the mount apparatus from the first state toward the second state. When viewing the second mount from the center axis direction of the second mount, in the circumferential direction of the second mount, the first contact pin is disposed on a same angle range as a first claw of the plurality of claws of the mount apparatus. The first claw is arranged to start engaging with a corresponding claw of the accessory earlier than the first contact pin comes into contact with a contact face of the accessory, during the relative rotation of the mount apparatus from the first state toward the second state.