Sheet Conveying Device Timing Correction Mechanism

Solution Overview

Problem

Existing sheet conveying devices struggle to promptly return to the reference position after correcting positional deviations during high-speed continuous sheet conveyance, leading to inefficiencies in image formation due to delayed preparation for subsequent sheets.

Innovation Solution

Incorporating a detector to timing the separation of the correcting member from the sheet, allowing it to move immediately to the reference position, ensuring timely correction and preparation for the next sheet.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the correcting member waits until after sheet conveyance to return to the reference position, then it can avoid interfering with sheet conveyance, but it cannot return to the reference position in time for high-speed continuous conveyance

Engineering Contradiction:

Improvepositional correction accuracyVSAvoidsheet conveyance speed

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The correcting member returns to the reference position before the sheet conveyance begins. The detector detects the timing of sheet arrival, and the control unit commands the correcting member to return to the reference position in advance, ensuring it is ready for the next correction operation without interfering with the current sheet conveyance.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

A detector is introduced to detect the timing of sheet arrival and separation. This feedback information is used by the control unit to precisely control when the correcting member should return to the reference position, enabling synchronized operation that maintains both high speed and accuracy.

Inventive Principle:

Principle #23Feedback

2Productivity

If the correcting member moves to the reference position while holding the sheet, then it can be ready for the next sheet, but it causes positional deviation of the current sheet

Engineering Contradiction:

Improvepreparation timing for next sheetVSAvoidsheet position accuracy

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The correcting member returns to the reference position before the sheet conveyance begins. The detector detects the timing of sheet arrival, and the control unit commands the correcting member to return to the reference position in advance, ensuring it is ready for the next correction operation without interfering with the current sheet conveyance.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The correcting member's position is dynamically adjusted based on real-time detection. During sheet conveyance, the correcting member maintains its corrective position, and only returns to the reference position after detecting sheet separation, enabling adaptive positioning that maintains precision while preparing for the next operation.

Inventive Principle:

Principle #15Dynamics

3Productivity

If the correcting member returns to the reference position immediately after sheet separation, then it prepares in time for high-speed continuous conveyance, but requires precise timing detection

Engineering Contradiction:

Improvecontinuous conveyance efficiencyVSAvoidseparation timing detection

Core Design Contradiction:

ProductivityVSDifficulty of detecting and measuring

Solution Approach 1:

A detector is introduced to detect the timing of sheet arrival and separation. This feedback information is used by the control unit to precisely control when the correcting member should return to the reference position, enabling synchronized operation that maintains both high speed and accuracy.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The detector automatically detects the sheet separation timing and triggers the correcting member's return to the reference position without requiring external intervention. The system self-regulates the timing based on actual sheet conveyance conditions, enabling precise coordination in high-speed operation.

Inventive Principle:

Principle #25Self-service

Data Source

PatentEP3492411B1Sheet conveying device and image forming apparatus incorporating the sheet conveying device

Publication Date: 2024.02.14 RICOH CO LTD

Figure 1
Figure 2A~2B
Figure 3A~3B

AI summary

A sheet conveying device (30), which is included in an image forming apparatus (1), includes a pair of rotary bodies (32) configured to convey a sheet (P) and correct a positional deviation of the sheet (P), a pair of downstream side sheet conveying bodies (33, 13, 18) disposed downstream from the pair of rotary bodies (32) and configured to convey the sheet (P), and a detector (40) configured to detect separation of the pair of rotary bodies (32). The pair of rotary bodies (32) moves the sheet (P) by moving from a home position on a sheet conveyance passage. The pair of rotary bodies (32) moves to the home position while the pair of downstream side sheet conveying bodies (33, 13, 18) is conveying the sheet (P), in response to detection of the separation of the pair of rotary bodies (32) by the detector (40).