Sheet Feeder Controller with Dynamic Retry Limits

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing sheet feeders are ineffective in accurately detecting error states, such as no sheet to be fed, which can lead to motor and transmission mechanism damage during retry attempts, and struggle to differentiate between error types for appropriate retry strategies.

Innovation Solution

A sheet feeder system with a tray, roller, motor, first sensor for rotational quantity detection, and second sensor for sheet position detection, along with a controller that adjusts retry limits based on accumulated rotational quantity and error state likelihood, to prevent damage and enhance error state resolution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If retry to perform sheet feeding is executed in response to detecting an error state, then the error state can be eliminated, but the motor and transmission mechanism may be damaged when the error state is no sheet to be fed

Engineering Contradiction:

Improveerror state eliminationVSAvoidmotor and transmission mechanism damage

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The system performs preliminary detection of the error state type before executing retry. By detecting whether the error state is caused by no sheet to be fed or other issues, the system can determine in advance whether retry is appropriate, thereby preventing motor damage while maintaining error elimination capability

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system uses feedback from error state detection to control retry execution. The detection unit provides information about the error state type, and the control unit uses this feedback to decide whether to permit retry, creating a closed-loop control system that prevents harmful retry while enabling beneficial retry

Inventive Principle:

Principle #23Feedback

2Reliability

If retry upper limit is set to a high value to ensure error elimination, then more retry attempts are available, but the risk of motor damage increases when no sheet is present

Engineering Contradiction:

Improveerror state resolutionVSAvoidmotor damage risk

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

The system applies different retry upper limit values based on the local condition of error state type. When no sheet to be fed is detected, a low retry upper limit (first value) is applied. When other error states are detected, a high retry upper limit (second value) is applied, optimizing both error resolution and damage prevention for each specific condition

Inventive Principle:

Principle #3Local quality

3Loss of energy

If retry upper limit is set to a low value to prevent motor damage, then energy loss is reduced, but the ability to resolve certain error states is compromised

Engineering Contradiction:

Improvemotor damage preventionVSAvoiderror state resolution capability

Core Design Contradiction:

Loss of energyVSReliability

Solution Approach 1:

The retry upper limit is made dynamic rather than fixed. The control unit changes the retry upper limit value based on the detected error state type, allowing the system to adapt the retry strategy to the specific situation, thereby preventing motor damage in no-sheet conditions while maintaining full error resolution capability in other conditions

Inventive Principle:

Principle #15Dynamics

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 system effectively eliminates sheet feeding errors without damaging the feeder, by setting appropriate retry limits and ensuring accurate error state detection, thereby preventing motor and transmission damage and improving sheet conveyance to the image recorder.

Implementation Method 1

a first sensor configured to detect a rotational quantity of the roller

Methodology Applied

Scientific EffectRotational detection:

Implementation Method 2

a second sensor configured to detect that the sheet reaches a particular position on the conveyance path

Methodology Applied

Scientific EffectPosition detection:

Implementation Method 3

a motor configured to generate a driving force to rotate the roller in the particular direction

Methodology Applied

Scientific EffectElectromagnetic conversion:

Data Source

PatentUS10118782B2Sheet feeder, image recording apparatus having the sheet feeder, and computer-readable medium therefor

Publication Date: 2018.11.06 BROTHER KOGYO KK

AI summary

A sheet feeder includes a controller configured to perform a driving process of supplying a motor with an electric current to rotate a roller, perform a stopping process of stopping supplying the electric current in response to determining that the motor has not rotated before a second sensor detects a sheet, when an accumulated rotational quantity of the roller is less than a threshold, set a retry upper limit to a first value, the accumulated rotational quantity being detected by a first sensor in the driving process performed for a first time, when the accumulated rotational quantity of the roller is equal to or more than the threshold, set the retry upper limit to a second value more than the first value, and repeatedly perform the driving process and the stopping process until a number of retries reaches the retry upper limit or until the second sensor detects the sheet.