Roll-Fed Recording Apparatus with Splice-Aware Pre-Ejection Conveyance

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Solution Overview

Problem

Existing recording apparatuses generate excessive waste sheets due to the conveyance of sheets to avoid recording on spliced portions, which can damage the recording head and reduce conveyance accuracy.

Innovation Solution

Implementing a pre-ejection conveyance control mechanism that sets the amount of sheet to be conveyed before ejection based on splice detection and door status during jam clearing operations, ensuring no spliced portion is present in the recording path when ejection starts.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the sheet is conveyed to avoid recording on the spliced portion, then the recording head is protected from damage, but the amount of waste sheet increases

Engineering Contradiction:
Improverecording head protectionVSAvoidwaste sheet amount
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The system performs preliminary detection of spliced portions using an optical sensor before the recording head reaches them. When a splice is detected, the conveyance unit pre-conveys the sheet by a calculated amount to reposition the splice away from the recording head's path, preventing damage while minimizing waste by only conveying the necessary distance

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The optical sensor continuously monitors the sheet for spliced portions and provides feedback to the control unit. Based on this feedback, the system dynamically adjusts the conveyance amount to precisely position the sheet so that the splice is located at an optimal position away from the recording head, reducing unnecessary sheet waste while ensuring protection

Inventive Principle:
Principle #23Feedback

2Reliability

If a fixed amount of sheet is conveyed each time a splice is detected, then the recording head is protected, but conveyance accuracy deteriorates

Engineering Contradiction:
Improverecording head protectionVSAvoidconveyance accuracy
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

Instead of using a fixed conveyance amount, the system dynamically calculates the conveyance distance based on the actual position of the detected splice relative to the recording head. The control unit adjusts the conveyance amount in real-time to precisely position the splice at an optimal location, maintaining high conveyance accuracy while protecting the recording head

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP4640439A1Recording apparatus and control method thereof
Publication Date: 2025.10.29 CANON KK
  • EP4640439A1 patent drawingFigure 1
  • EP4640439A1 patent drawingFigure 2
  • EP4640439A1 patent drawingFigure 3

AI summary

A sheet supplied from a roll is conveyed by a first conveyance unit and a second conveyance unit located on a downstream side of the first conveyance unit. The sheet is conveyed by a first conveyance amount while being inspected by a sensor for a spliced portion, which is a splice between sheets, and in a case where the spliced portion is not detected while the sheet is conveyed by the first conveyance amount, the first conveyance amount is changed in a control operation of causing a head to start ejecting liquid onto the sheet.