Conveyance Apparatus Speed Fluctuation Detection

Solution Overview

Problem

Existing image forming systems face challenges in accurately processing target images due to abrupt and large fluctuations in conveyance speed, leading to image defects such as uneven image density and distortion, caused by the switching of conveyance forces and loads from multiple conveyors during the image reading process.

Innovation Solution

An image forming system with a conveyance apparatus that includes multiple conveyors and an image reader, where the circuitry controls the image reader to detect and correct for large abrupt speed fluctuations by reading pattern images at specific timings, such as when the trailing edge of a recording material exits an upstream conveyor and the leading edge enters a downstream conveyor, ensuring accurate image processing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If multiple conveyors are used to convey recording materials, then conveyance capability and productivity are improved, but abrupt speed fluctuations occur during conveyor switching causing image defects

Engineering Contradiction:

Improveconveyance capabilityVSAvoidconveyance speed stability

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The system performs preliminary detection of conveyance speed fluctuations by reading pattern images at specific timings before normal image processing. The control unit detects speed changes based on pattern image read results and prepares correction actions in advance, preventing image defects before they occur during normal operation.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system establishes a feedback loop where the reading device continuously monitors pattern images on recording materials, the control unit analyzes the read data to detect conveyance speed fluctuations, and the system adjusts subsequent reading operations based on detected fluctuations. This closed-loop control ensures conveyance stability while maintaining high productivity.

Inventive Principle:

Principle #23Feedback

2Measurement precision

If pattern images are read continuously during conveyance, then image quality monitoring is improved, but conveyance speed fluctuations cause false defect detection

Engineering Contradiction:

Improveimage quality monitoringVSAvoidfalse defect detection

Core Design Contradiction:

Measurement precisionVSLoss of information

Solution Approach 1:

The system performs preliminary detection of conveyance speed fluctuations by reading pattern images at specific timings before normal image processing. The control unit detects speed changes based on pattern image read results and prepares correction actions in advance, preventing image defects before they occur during normal operation.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system establishes a feedback loop where the reading device continuously monitors pattern images on recording materials, the control unit analyzes the read data to detect conveyance speed fluctuations, and the system adjusts subsequent reading operations based on detected fluctuations. This closed-loop control ensures conveyance stability while maintaining high productivity.

Inventive Principle:

Principle #23Feedback

3Reliability

If reading timing is adjusted to avoid conveyor switching, then conveyance stability is improved, but reading accuracy during speed fluctuations deteriorates

Engineering Contradiction:

Improveconveyance stabilityVSAvoidreading accuracy

Core Design Contradiction:

ReliabilityVSMeasurement precision

Solution Approach 1:

The system performs preliminary detection of conveyance speed fluctuations by reading pattern images at specific timings before normal image processing. The control unit detects speed changes based on pattern image read results and prepares correction actions in advance, preventing image defects before they occur during normal operation.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system dynamically changes reading parameters based on detected conveyance conditions. When speed fluctuations are detected, the control unit adjusts reading timing and position parameters to compensate for the fluctuations, maintaining reading accuracy despite varying conveyance speeds during pattern image reading.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentEP3769969B1Conveyance apparatus, image defect detection device, and image forming system

Publication Date: 2023.02.22 RICOH CO LTD

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Figure 3A~3B

AI summary

A conveyance apparatus (30; 40; 50; 60) includes a plurality of conveyors (33; 34; 41; 42; 55; 56; 61) to convey recording materials including a recording material (P1) and a succeeding recording material (P2) following the recording material (P1), an image reader (51) to read a pattern image on each of the recording materials being conveyed, and circuitry (200) to control the image reader (51) to read the pattern image on the recording material (P1) in a period including a timing, for example, at which a trailing edge of the recording material (P1) being conveyed by at least two of the plurality of conveyors (33; 34; 41; 42; 55; 56; 61) exits an upstream conveyor among the at least two of the plurality of conveyors (33; 34; 41; 42; 55; 56; 61) in a direction of conveyance of the recording materials (P1; P2).