Conveyance Apparatus Synchronization for Sheet Ejection

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Solution Overview

Problem

Existing image forming apparatuses face challenges in reliably detecting and ejecting remaining sheets from the drum surface due to air suction and the inability to install photosensors, leading to potential jamming issues during the initialization process.

Innovation Solution

A conveyance apparatus with a bearing rotator, entrance rotator, exit rotator, and a recording medium detector, where the first driver rotates these components and the downstream conveyor to ensure the remaining sheet is conveyed to the detector, allowing for reliable ejection by controlling the rotation and conveyance operations to align with the sheet's movement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Difficulty of detecting and measuring

If a photosensor is attached to the drum surface to detect remaining sheets, then detection capability is improved, but the sheet cannot be properly adhered to the drum surface at the hole position

Engineering Contradiction:
Improveremaining sheet detection capabilityVSAvoidsheet adhesion to drum surface
Core Design Contradiction:
Difficulty of detecting and measuringVSReliability

Solution Approach 1:

A transparent window is introduced as an intermediary structure that allows light to pass through the drum surface for photosensor detection without compromising the drum's ability to adhere sheets. The window acts as a mediator between the detection requirement and the adhesion requirement, enabling both functions to coexist.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Device complexity

If the image forming device and fixing device are controlled independently with separate initialization processes, then device independence is improved, but the remaining sheet may not be conveyed to the fixing device in time

Engineering Contradiction:
Improveindependent device controlVSAvoidremaining sheet ejection reliability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The image forming device performs its initialization process first to eject any remaining sheets from the drum surface before the fixing device starts its initialization. This preliminary action ensures that the fixing device receives no remaining sheets to handle, preventing potential jamming while maintaining independent device control.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system uses detection signals from the fixing device's sheet detector to coordinate the initialization processes. When no sheet is detected, the fixing device knows the image forming device has successfully ejected remaining sheets, creating a feedback mechanism that ensures reliable operation.

Inventive Principle:
Principle #23Feedback

3Reliability

If the drum surface is made opaque to maintain sheet adhesion, then sheet adhesion is improved, but remaining sheet detection becomes impossible

Engineering Contradiction:
Improvesheet adhesion to drum surfaceVSAvoidremaining sheet detection capability
Core Design Contradiction:
ReliabilityVSDifficulty of detecting and measuring

Solution Approach 1:

The drum surface is designed with a local difference: most of the surface remains opaque for sheet adhesion, while a specific localized area (the window) is transparent to allow light transmission for photosensor detection. This local quality change enables both functions to coexist without compromising either.

Inventive Principle:
Principle #3Local quality

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

This solution enables reliable detection and ejection of remaining sheets, minimizing recovery time and preventing jamming by synchronizing the rotation and conveyance operations to ensure the sheet is properly conveyed and detected, thus enhancing the initialization process efficiency.

Implementation Method 1

a bearing rotator that rotates to convey a recording medium

Methodology Applied
Scientific EffectRotation:

Implementation Method 2

an entrance rotator that receives a recording medium fed from upstream at a receiving position and delivers the recording medium to the bearing rotator while rotating to convey the recording medium

Methodology Applied
Scientific EffectRotation:

Implementation Method 3

an exit rotator that receives a recording medium conveyed by rotation of the bearing rotator and delivers the recording medium at a delivery position downstream in a recording medium conveyance direction while rotating to convey the recording medium

Methodology Applied
Scientific EffectRotation:

Implementation Method 4

a downstream conveyor that receives a recording medium conveyed by rotation of the exit rotator at the delivery position and conveys the recording medium downstream in a recording medium conveyance direction

Methodology Applied
Scientific EffectConveyance:

Data Source

PatentEP4124459B1Conveyance apparatus
Publication Date: 2024.10.16 RICOH CO LTD
  • EP4124459B1 patent drawingFigure 1
  • EP4124459B1 patent drawingFigure 2
  • EP4124459B1 patent drawingFigure 3

AI summary

A conveyance apparatus (1, 1a) includes a bearing rotator (31), an entrance rotator (34), an exit rotator (35), a first driver (212), a downstream conveyor (41), a second driver (213), and a recording medium detector (43). The entrance rotator receives a recording medium at a first position. The downstream conveyor receives the medium at a second position. As a process of removing the medium, the first driver starts rotation operation after the second driver starts driving the downstream conveyor and rotates the rotators for not less than a period of time for the medium to be conveyed from the first position to the second position. The second driver continues driving the downstream conveyor for not less than a period of time for the medium to be conveyed from the second position to a position at which the medium is detected after the rotation operation of the first driver is stopped.