Sheet Conveyance Apparatus with Opening Detection for High-Speed Registration

Solution Overview

Problem

Existing sheet conveyance systems in image reading and forming apparatuses often damage sheets with punch holes during registration control, especially when high-velocity operation is required, as they struggle to balance conveyance speed with the need to prevent bending and skew correction.

Innovation Solution

A sheet conveyance apparatus equipped with an opening detector to identify punch holes, a registration device for posture correction, and a dual velocity system that maintains high-speed conveyance without stopping sheets with detected holes, allowing continuous operation at regular or higher velocities based on hole presence and location.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If registration control is performed to correct sheet tilt posture, then sheet alignment precision is improved, but sheet damage (bending) occurs at the front end

Engineering Contradiction:

Improvesheet alignment precisionVSAvoidsheet damage

Core Design Contradiction:

Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The opening detector performs preliminary detection of punch holes at the sheet front end before registration control is executed. Based on this advance detection, the system decides whether to perform registration control, thereby preventing sheet damage before it occurs.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system uses feedback from the opening detector to control the registration device. When a punch hole is detected, the registration control is cancelled; when no punch hole is detected, registration control is performed. This feedback mechanism resolves the contradiction by adapting the registration control to sheet conditions.

Inventive Principle:

Principle #23Feedback

2Object-affected harmful factors

If simple avoidance control is used to prevent sheet damage, then sheet damage is reduced, but processing speed decreases and high-velocity operation cannot be achieved

Engineering Contradiction:

Improvesheet damageVSAvoidprocessing speed

Core Design Contradiction:

Object-affected harmful factorsVSProductivity

Solution Approach 1:

The system applies different control strategies to different sheet types locally. Sheets with punch holes at the front end receive avoidance control (no registration control), while sheets without front-end punch holes receive normal registration control. This local differentiation maintains high processing speed while preventing damage to vulnerable sheets.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The system changes the registration control parameter (whether to perform registration control or not) based on the detected sheet condition. This parameter change allows the system to optimize between sheet protection and processing speed for different sheet types.

Inventive Principle:

Principle #35Parameter changes

3Manufacturing precision

If registration control is performed on sheets with punch holes, then alignment correction is achieved, but front end bending occurs due to weak sheet structure

Engineering Contradiction:

Improvealignment correctionVSAvoidsheet front end strength

Core Design Contradiction:

Manufacturing precisionVSStrength

Solution Approach 1:

The opening detector performs preliminary detection of punch holes at the sheet front end before registration control is executed. Based on this advance detection, the system decides whether to perform registration control, thereby preventing sheet damage before it occurs.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system uses feedback from the opening detector to control the registration device. When a punch hole is detected, the registration control is cancelled; when no punch hole is detected, registration control is performed. This feedback mechanism resolves the contradiction by adapting the registration control to sheet conditions.

Inventive Principle:

Principle #23Feedback

Data Source

PatentUS10961069B2Sheet conveyance apparatus

Publication Date: 2021.03.30 SHARP KK

AI summary

When an open hole is detected at the front end of a sheet at a conveyance start position, a registration operation to correct a tilt posture of the sheet is avoided, and the present velocity is retrained to convey the sheet without temporarily stopping the sheet having the tilt posture.