Sheet Feed Speed Detection Based on Lifted Stack Timing

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Solution Overview

Problem

Existing sheet conveying devices in image forming apparatuses experience a decrease in the accuracy of conveying speed measurement due to sheets being pulled from the stack before the lift mechanism fully engages, leading to inaccurate speed calculations.

Innovation Solution

The solution involves acquiring speed information only when the stack of sheets is lifted by the lift portion, using the detection portion to measure the conveying speed of the sheet supply portion, and setting initial speed information based on specific conditions to enhance accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If speed information is acquired continuously without checking lift portion status, then the acquisition process is simple and fast, but the measurement precision deteriorates due to inaccurate speed calculations when sheets are pulled from the stack

Engineering Contradiction:

Improveconveying speed measurement accuracyVSAvoidacquisition processing complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The acquisition processing portion checks whether the lift portion has lifted the stack of sheets before acquiring speed information. This preliminary action ensures that speed measurement is only performed when the sheet stack is properly positioned and stable, preventing inaccurate measurements from sheets being pulled from the stack.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system uses feedback from the lift portion status to control the speed information acquisition process. By continuously monitoring whether the lift portion has successfully lifted the sheet stack and using this feedback to determine when to acquire speed data, the system ensures measurement accuracy while maintaining efficient operation.

Inventive Principle:

Principle #23Feedback

2Measurement precision

If speed information is acquired only when the stack is lifted by the lift portion, then the measurement precision improves, but the productivity decreases due to fewer measurement opportunities

Engineering Contradiction:

Improveconveying speed measurement accuracyVSAvoidspeed measurement frequency

Core Design Contradiction:

Measurement precisionVSProductivity

Solution Approach 1:

The acquisition processing portion continuously monitors the lift portion status and uses this feedback to determine optimal moments for speed information acquisition. This ensures that measurements are taken at the highest possible frequency during valid conditions (when the stack is properly lifted), maximizing both accuracy and productivity.

Inventive Principle:

Principle #23Feedback

Data Source

PatentUS20250388422A1Sheet conveying device capable of suppressing lowering of acquisition accuracy of sheet conveying speed, image forming apparatus, and acquisition method

Publication Date: 2025.12.25 KYOCERA DOCUMENT SOLUTIONS INC

AI summary

A sheet conveying device includes a lift portion, a sheet supply portion, a detection portion, and an acquisition processing portion. The lift portion lifts a stack of sheets. The sheet supply portion includes a conveying member which rotates while being in contact with an upper surface of the stack of sheets lifted by the lift portion, and supplies a sheet that comes into contact with the conveying member to a conveying path. The detection portion detects the sheet supplied by the sheet supply portion on the conveying path. The acquisition processing portion acquires, only when the stack of sheets is lifted by the lift portion, speed information related to a conveying speed of the sheet by the sheet supply portion using the detection portion.