Sheet Conveyance Roller Direction Switching During Guide Movement

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Solution Overview

Problem

In image forming apparatuses, the existing sheet conveyance systems face productivity reductions due to delays in switching the rotation direction of discharge reverse conveyance rollers during duplex printing, as the driving force is not input to these rollers while the moving member is switching positions.

Innovation Solution

A sheet conveyance apparatus with a roller that rotates in two directions, a guide member that moves between positions, and a drive switching unit that outputs driving force to the roller while the guide member moves, allowing simultaneous rotation direction switching of the roller and guide member position change.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the driving force is not input to the discharge reverse conveyance roller while the moving member is moving, then the moving member can switch positions reliably, but the rotation direction switching of the roller is delayed and productivity is reduced

Engineering Contradiction:

Improvemoving member position switchingVSAvoidduplex printing speed

Core Design Contradiction:

Ease of operationVSProductivity

Solution Approach 1:

The roller begins rotating in the reversed direction before the moving member completes its position switching, so that when the moving member finishes switching, the roller is already in the correct rotation state for duplex conveyance, eliminating idle time and improving productivity

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system dynamically controls the timing of driving force input to the roller, allowing the roller to start rotating in the reversed direction during the moving member's position switching process, rather than waiting for the switching to complete

Inventive Principle:

Principle #15Dynamics

2Reliability

If the roller rotation direction is switched only after the moving member movement is completed, then the moving member can reliably guide the sheet, but it takes time to switch the rotation direction

Engineering Contradiction:

Improvesheet guidance reliabilityVSAvoidrotation direction switching time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The roller starts rotating in the reversed direction during the moving member's position switching process, so that the rotation direction switching is completed before the moving member finishes its movement, reducing the total time loss while maintaining reliability

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The roller maintains continuous rotation during the entire process, switching direction mid-motion rather than stopping and restarting, which eliminates idle time while the moving member completes its position switching

Inventive Principle:

Principle #20Continuity of useful action

Data Source

PatentUS12006174B2Sheet conveyance apparatus and image forming apparatus

Publication Date: 2024.06.11 CANON KK

AI summary

A sheet conveyance apparatus includes a conveyance section, the conveyance section including a roller rotatable in a first rotation direction and a second rotation direction, a guide member configured to move between a first position and a second position, a drive source, a drive switching unit including an input unit, an output unit, and a switching unit, a drive interruption unit configured to transition between a transmission state and a non-transmission state. The roller is configured to rotate by the driving force output from the output unit of the drive switching unit while the guide member moves between the first position and the second position.