Auto Document Feeder Motor Control for Paper Pickup
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Solution Overview
Problem
Auto document feeders (ADFs) face challenges in stably picking up various types of sheets of paper, leading to repeated paper feeding operations and eventual error messages when the paper is not picked up within a maximum number of attempts, which hinders convenient scanning and reading.
Innovation Solution
An ADF system with a retry controller that adjusts the motor speed and current to increase torque for picking up sheets, including a motor current controller, motor speed controller, and paper distance controller, to stabilize paper feeding by varying the motor's speed and current supply based on sensor detection, ensuring successful pickup and scanning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the feeder repeatedly performs paper pickup operation with constant motor speed and current, then the pickup mechanism moves between positions to attempt pickup, but the sheet of paper is not normally picked up and error message is displayed
Solution Approach 1:
The patent applies dynamics by making the motor speed and current variable rather than constant. The retry controller dynamically adjusts motor parameters based on pickup attempts: initially using constant speed/current, then switching to variable speed with increasing current for retry attempts. This dynamic adjustment allows the system to adapt to different paper conditions and successfully pickup sheets that would otherwise fail, resolving the contradiction between pickup reliability and scanning efficiency.
Solution Approach 2:
The patent changes motor operating parameters (speed and current) based on the pickup attempt status. For the first pickup attempt, the motor runs at constant speed with constant current. For retry attempts, the system increases motor current and adjusts speed to optimize torque for difficult pickups. This parameter change strategy enables successful pickup of various paper types while maintaining overall system productivity by reducing error messages.
2Force
If the motor speed is decreased and current is increased for retry pickup, then the torque increases to pick up difficult sheets, but the scanning speed must be adjusted to match the feeding speed
Solution Approach 1:
The patent implements feedback control where the retry controller monitors pickup status and adjusts motor parameters accordingly. When a pickup fails, the system receives feedback and responds by increasing current and adjusting speed for the next attempt. After successful pickup, the system detects the sheet position and adjusts scanning speed to match the actual paper feeding speed, ensuring proper synchronization between scanning and feeding operations.
Solution Approach 2:
The system dynamically adjusts both motor speed and scanning speed based on operational conditions. During retry pickup, motor speed decreases while current increases to maximize torque. After successful pickup, the scanning speed is dynamically adjusted to match the paper feeding speed, ensuring proper synchronization. This dynamic speed adjustment resolves the contradiction between generating sufficient torque and maintaining appropriate scanning speed.
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 stabilizes paper feeding, allowing for efficient and high-quality scanning of various paper types by adjusting motor parameters to ensure successful pickup and matching scanning speed with feeding speed, reducing errors and enhancing user convenience.
Implementation Method 1
a motor for driving the feeder
Data Source
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AI summary
Provided are an auto document feeder (ADF), a scanner including the ADF, and a method of controlling auto document feeding. The ADF includes: a feed unit picking up a sheet of paper and carrying the sheet of paper to a scan unit; a feed control unit controlling the feed unit; and a retry control unit. If a sheet of paper is not normally picked up by the feed unit, the retry control unit decreases a speed of a motor driving the feed unit or increases a current supplied to the motor for picking up the sheet of paper. Therefore, although sheets of paper are not normally fed when a user intends to use various kinds of sheets of paper with the ADF, the retry control unit may stabilize feeding of the feeding of the sheets of paper. Thus, efficient, convenient, and high-quality paper feeding may be possible.