Paper Feed Device with Sensor-Based Jam Detection

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Solution Overview

Problem

Existing paper feed devices in image forming apparatuses face challenges in accurately detecting paper presence and preventing unnecessary retry processing due to wear or slippery paper conditions, leading to potential misdetctions of paper jam.

Innovation Solution

A paper feed device with a set-state sensor, paper feed unit, transport unit, and control unit that detects paper presence using a sensor system, performs intermittent paper feed retries, and determines non-feed jams based on sensor outputs, preventing wasteful retry processing and misdetctions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If retry processing is performed repeatedly to handle paper feed failures, then the system can recover from temporary feed issues, but it causes wasteful operations and may misdetect non-feed jams as actual jams

Engineering Contradiction:

Improvepaper feed reliabilityVSAvoidwasteful retry processing time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The control unit checks paper presence in advance before each retry operation. By performing this preliminary check, the system avoids executing retry processing when no paper is present, thereby eliminating wasteful operations and preventing misdetetection of non-feed jams as actual jams.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system continuously monitors paper presence status and uses this feedback information to dynamically control the retry processing. When the sensor detects that paper is not present, the control unit receives this feedback and immediately terminates further retry operations, adapting the system behavior based on real-time conditions.

Inventive Principle:

Principle #23Feedback

2Productivity

If the system performs intermittent paper feed retries to handle slippery paper or worn rollers, then paper feed success rate improves, but unnecessary retries occur when paper is already exhausted

Engineering Contradiction:

Improvepaper feed success rateVSAvoidunnecessary retry operations

Core Design Contradiction:

ProductivityVSObject-generated harmful factors

Solution Approach 1:

Before executing each intermittent paper feed retry, the control unit performs a preliminary check to determine whether paper is present on the paper tray. This preliminary action prevents unnecessary retry operations from occurring when paper is already exhausted, thereby eliminating harmful waste operations while preserving beneficial retries when paper is actually present.

Inventive Principle:

Principle #10Preliminary action

3Reliability

If retry processing is implemented without checking paper presence, then the system handles feed failures robustly, but it cannot distinguish between actual jams and empty tray conditions

Engineering Contradiction:

Improveerror handling reliabilityVSAvoidjam detection accuracy

Core Design Contradiction:

ReliabilityVSMeasurement precision

Solution Approach 1:

The control unit continuously receives feedback from the paper presence sensor during retry processing. This feedback mechanism enables the system to distinguish between actual paper jams (where paper is present but won't feed) and empty tray conditions (where no paper is present), thereby improving jam detection accuracy while maintaining robust error handling.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The system replaces purely mechanical retry operations with an intelligent control system that uses sensor feedback to make decisions. Instead of blindly repeating mechanical feed attempts, the control unit substitutes mechanical action with sensor-based detection and conditional logic, enabling precise distinction between different failure conditions.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The solution effectively reduces wasteful retry processing and misdetctions of non-feed jams by accurately detecting paper presence and terminating retries when no paper is detected, improving operational efficiency and user experience.

Implementation Method 1

The set-state sensor includes an actuator that is configured to move when paper is set. The set-state sensor is arranged at a position where any set paper can be detected, and outputs different values depending on the position of the actuator.

Methodology Applied

Scientific EffectWeight detection:

Implementation Method 2

The paper feed sensor is configured to detect that the paper has been sent out of the paper tray by the paper feed operation of the paper feed unit.

Methodology Applied

Scientific EffectOptical detection:

Data Source

PatentUS9670019B2Paper feed device, and document transport device and image forming apparatus including the same

Publication Date: 2017.06.06 KYOCERA DOCUMENT SOLUTIONS INC

AI summary

A paper feed device includes a paper tray, a set-state sensor, a paper feed unit, and a control unit. The control unit checks an output from the set-state sensor each time before the start of the intermittent paper feed. In the case where no paper feed is detected even after the prescribed number of times of the intermittent paper feed, the control unit determines that a non-feed jam has occurred. In the case where it is detected that there is no paper on the paper tray before the number of repetition of the intermittent paper feed reaches the prescribed number of times, the control unit causes the paper feed unit to terminate the retry processing and determines that, with no paper on the paper tray, it is not the non-feed jam.