Image Forming Apparatus Positional Displacement Correction

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Solution Overview

Problem

Image forming apparatuses that cannot freely adjust the transport velocity of a medium relative to the rotational velocity of an image carrier face challenges in correcting positional displacement between the image and the medium.

Innovation Solution

An image forming apparatus with a control unit that adjusts the image forming timing based on the variation in the ratio of the rotation velocity of the transfer unit to the rotation velocity of the image carrier, ensuring the image forming timing is synchronized with the transport velocity of the medium, thereby correcting positional displacement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the transport velocity of the medium is not freely adjustable relative to the rotational velocity of the image carrier, then the device structure is simpler, but positional displacement between the image and the medium cannot be corrected

Engineering Contradiction:

Improvepositional accuracy of image transferVSAvoidcomplexity of velocity adjustment mechanism

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

Instead of adjusting the transport velocity of the medium to match the image carrier rotation, the patent inverts the approach by adjusting the image forming timing to match the medium transport. The control unit changes when the image is formed on the image carrier based on the ratio between transfer unit rotation velocity and image carrier rotation velocity, allowing positional accuracy to be corrected without complex velocity adjustment mechanisms.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent changes the timing parameter of image formation rather than changing the velocity parameter of medium transport. By adjusting the image forming timing in accordance with variation in the velocity ratio, the system achieves positional displacement correction through a simple timing parameter change without requiring complex mechanical velocity adjustment mechanisms.

Inventive Principle:

Principle #35Parameter changes

2Manufacturing precision

If the image forming timing is fixed, then the control system is simpler, but positional displacement between image and medium occurs when medium thickness varies

Engineering Contradiction:

Improvepositional accuracy of image transferVSAvoidcomplexity of timing control system

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The control unit continuously monitors the ratio between the rotation velocity of the transfer unit and the rotation velocity of the image carrier, and adjusts the image forming timing based on this feedback. This closed-loop control ensures that positional displacement is corrected automatically in response to variations in medium thickness or velocity fluctuations, maintaining high positional accuracy with a relatively simple control system.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The patent dynamically adjusts the image forming timing parameter in response to changes in the velocity ratio, which varies with medium thickness. This parameter change approach allows the system to adapt to different operating conditions without requiring complex mechanical adjustments, achieving high positional accuracy through intelligent timing control.

Inventive Principle:

Principle #35Parameter changes

3Manufacturing precision

If the transport velocity of the medium is adjusted to match image carrier rotation, then positional accuracy is improved, but the device requires complex velocity adjustment mechanisms

Engineering Contradiction:

Improvepositional accuracy of image transferVSAvoidease of velocity synchronization

Core Design Contradiction:

Manufacturing precisionVSEase of operation

Solution Approach 1:

The patent inverts the conventional approach by not adjusting the medium transport velocity to match the image carrier rotation. Instead, it adjusts the image forming timing to match the medium transport, achieving the same positional accuracy goal without requiring complex velocity adjustment mechanisms or sensors for medium thickness detection.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The system uses the existing velocity relationship between the transfer unit and image carrier to automatically determine the appropriate image forming timing. The control unit calculates the timing based on the measurable velocity ratio, allowing the system to self-adjust without external intervention or complex mechanical adjustment mechanisms, improving ease of operation.

Inventive Principle:

Principle #25Self-service

Data Source

PatentUS11567434B1Image forming apparatus capable of correction of positional displacement between an image and a medium

Publication Date: 2023.01.31 FUJIFILM BUSINESS INNOVATION CORP

AI summary

An image forming apparatus includes an image carrier that is capable of holding an image on a surface thereof while rotating, an image forming unit that forms the image on the image carrier, a transfer unit that transfers the image from the image carrier to a medium while rotating, a transport unit that circulates as the transfer unit rotates and that transports the medium to a transfer region while holding the medium, and a control unit that changes a timing at which the image forming unit forms the image in accordance with variation in a ratio of a rotation velocity of the transfer unit to a rotation velocity of the image carrier.