Belt Deviation Detection with Preventing Member

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Solution Overview

Problem

Conventional image forming apparatuses face challenges in accurately detecting belt member deviation in the belt width direction, particularly at high speeds, due to twisting or waving of the belt member, which leads to inaccurate detection and potential damage from contact with other units.

Innovation Solution

A belt device with a detecting unit that includes a swaying member with a curved contact surface and a preventing member to prevent deviations in directions other than the belt width and rotation directions, ensuring accurate detection and correction of belt member deviations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a swaying member with a large area contact portion is used to detect belt deviation, then the detection structure is simple, but the detection accuracy decreases due to additional deviation components in perpendicular directions

Engineering Contradiction:

Improvedetection structure complexityVSAvoidbelt deviation detection accuracy

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

The invention segments the contact interaction by introducing a preventing member that separates the detection function from the support function. The preventing member with line contact isolates the swaying member's contact portion, allowing it to detect only belt width direction deviation without being influenced by perpendicular direction movements, thus resolving the accuracy issue while maintaining structural simplicity.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The preventing member acts as an intermediary between the belt and the swaying member. It prevents the belt from deviating in directions other than the belt width direction at the detection position, ensuring that the swaying member only responds to relevant deviation components and improving measurement precision without complicating the overall detection structure.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Productivity

If the belt member moves at high speed, then productivity increases, but the belt waves in the perpendicular direction causing inaccurate detection

Engineering Contradiction:

Improveimage forming speedVSAvoidbelt deviation detection accuracy

Core Design Contradiction:

ProductivityVSMeasurement precision

Solution Approach 1:

The preventing member applies preliminary anti-action by restraining the belt from waving in the perpendicular direction before the swaying member can detect it. This preventive measure eliminates the source of detection errors that would otherwise occur at high speeds, allowing accurate detection to be maintained throughout the high-speed operation.

Inventive Principle:

Principle #9Preliminary anti-action

Solution Approach 2:

The invention replaces the mechanical constraint approach (physically restricting belt movement) with a detection-focused approach. Instead of trying to mechanically eliminate all belt movements, the preventing member selectively constrains only the harmful perpendicular direction waves while allowing the belt to move freely in the rotation direction, maintaining high-speed operation accuracy.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Stability of the object's composition

If the swaying member contacts the belt over a large area, then the attachment is stable, but chronological changes in detection accuracy occur due to fraying and wear

Engineering Contradiction:

Improveswaying member attachment stabilityVSAvoiddetection accuracy consistency

Core Design Contradiction:

Stability of the object's compositionVSMeasurement precision

Solution Approach 1:

The preventing member creates a local quality change by providing a specific line contact geometry that concentrates the interaction between the swaying member and belt. This localized contact reduces the overall contact area, minimizing wear and fraying while maintaining stable attachment, thus preserving detection accuracy consistency over time.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The preventing member's line contact geometry (curved surface) creates a specific contact pattern that reduces friction and wear compared to large area contact. The curved line contact allows the swaying member to maintain stable attachment while experiencing minimal wear, preventing chronological changes in detection accuracy.

Inventive Principle:

Principle #14Spheroidality (Curvature)

4Adaptability or versatility

If variable attachment angles of the swaying member are used, then adaptability to different belt positions is improved, but detection accuracy varies

Engineering Contradiction:

Improveattachment angle flexibilityVSAvoiddetection accuracy consistency

Core Design Contradiction:

Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The preventing member creates an equipotential condition by providing a line contact that maintains a consistent geometric relationship between the swaying member and belt regardless of attachment angle variations. This standardized contact geometry ensures that detection accuracy remains consistent even when the swaying member is attached at different angles, resolving the trade-off between adaptability and precision.

Inventive Principle:

Principle #12Equipotentiality

Data Source

PatentUS8391759B2Belt device, belt deviation detecting device, and image forming apparatus

Publication Date: 2013.03.05 RICOH CO LTD

AI summary

A belt device includes a belt member, a detecting unit, and a preventing member. The belt member is stretched over a plurality of rollers and moves in a predetermined moving direction. The detecting unit detects deviation of the belt member in a belt width direction of the belt member. The preventing member is arranged near the detecting unit and prevents deviation of the belt member in a direction other than the moving direction and the belt width direction.