Recording Medium Conveyance Speed Control for Continuous Image Forming

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Solution Overview

Problem

Existing image forming apparatuses experience a decrease in productivity when the type of recording medium is changed during printing due to interruptions in the image forming process.

Innovation Solution

The apparatus includes a conveyance section, a recording medium detector, and a controller that maintains the conveyance speed based on the information of the first recording medium, even when the type of the second recording medium differs, by using a first detection mode to set the initial conveyance speed and a second detection mode to adjust as necessary.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the image forming process is interrupted when the type of recording medium is changed, then the image forming conditions can be adjusted to match the new medium type, but productivity decreases due to the interruption

Engineering Contradiction:
Improveimage forming condition matchingVSAvoidproductivity
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The controller detects the recording medium type in advance before the conveyance speed needs to be adjusted. By detecting the medium type beforehand and pre-calculating the appropriate conveyance speed based on stored medium information, the system avoids interruptions and maintains continuous operation, thus resolving the contradiction between reliable condition matching and productivity

Inventive Principle:
Principle #10Preliminary action

2Reliability

If the conveyance speed is adjusted to match the detected recording medium type, then the image forming conditions can be optimized, but productivity decreases due to speed changes during printing

Engineering Contradiction:
Improveimage forming condition optimizationVSAvoidproductivity
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The system performs medium type detection before the conveyance speed adjustment is needed. The controller stores medium information (including optimal conveyance speeds) in advance and uses this pre-stored data to determine the correct speed without needing to change speed during the printing process, thus maintaining both optimization and productivity

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system dynamically selects the conveyance speed based on the detected medium type while maintaining the detected speed during the printing process. This allows the system to adapt to different medium types through dynamic selection of pre-determined speeds rather than changing speeds during operation, resolving the contradiction between optimized conditions and maintained productivity

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP4407377B1Image forming apparatus, method for controlling conveyance of recording medium, and program
Publication Date: 2025.08.06 KONICA MINOLTA INC
  • EP4407377B1 patent drawingFigure 1
  • EP4407377B1 patent drawingFigure 2~3
  • EP4407377B1 patent drawingFigure 4

AI summary

An image forming apparatus (1) includes a conveyance section (71a, 71b) that conveys a recording medium (M), a recording medium detector (91, 92, 1 00b) that detects information relating to the recording medium (M), and a controller (100) that causes the recording medium detector (91, 92, 100b) to detect information relating to a first recording medium (M) conveyed first by the conveyance section (71a, 71b) and to detect information relating to a recording medium (M) conveyed by the conveyance section (71a, 71b) after the first recording medium (M), causes the conveyance section (71a, 71b) to operate such that the recording media (M) are conveyed at a conveyance speed based on the information relating to the first recording medium (M), and causes the conveyance section (71a, 71b) to operate such that the recording media (M) are conveyed at the conveyance speed maintained even when the information relating to the recording medium (M) after the first recording medium (M) is detected to be different from the information relating to the first recording medium (M).