Medium Feed Roller Speed Control for Reliable Sequential Feeding
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Solution Overview
Problem
Existing medium conveying apparatuses face challenges in reducing the time required for medium feeding while efficiently managing stoppage and resumption of feeding due to insufficient storage space or short media distances, particularly in devices like scanners.
Innovation Solution
A medium conveying apparatus with a feed roller system controlled by a motor, sensors, and a processor to adjust rotation speeds based on detected media edges, employing constant, first, and second speeds for sequential feeding of media.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If the feed roller rotates at a constant high speed throughout the feeding process, then the medium feeding time is reduced, but medium separation reliability deteriorates because the front edge of subsequent media has not reached the nip position
Solution Approach 1:
The feed roller rotation speed is dynamically adjusted based on the feeding stage. During the separation period when the front edge of subsequent media has not reached the nip position, the feed roller rotates at a first rotation speed. After the front edge reaches the nip position, the system switches to a second rotation speed that is higher than the first speed, thereby reducing overall feeding time while maintaining reliable separation.
2Productivity
If the feed roller rotates at a high speed to reduce feeding time, then productivity improves, but medium separation reliability deteriorates when the front edge of subsequent media has not reached the nip position
Solution Approach 1:
The system implements dynamic speed adjustment where the feed roller operates at a lower first rotation speed during the critical separation period and transitions to a higher second rotation speed after separation is confirmed, thereby achieving both high productivity and reliable separation.
Solution Approach 2:
The control unit monitors the position of the front edge of subsequent media relative to the nip position and uses this feedback information to determine when to switch from the first rotation speed to the second rotation speed, ensuring separation reliability while maximizing feeding efficiency.
3Reliability
If the feed roller rotates at a low speed to ensure medium separation, then medium separation reliability improves, but the time required for medium feeding increases
Solution Approach 1:
The system uses dynamic speed adjustment to overcome the time loss. During the separation period, the feed roller rotates at a moderate first speed to ensure reliability. Once the front edge of subsequent media reaches the nip position, the system accelerates to a second speed higher than the first speed, thereby compensating for the initial slower pace and reducing overall feeding time while maintaining separation reliability.
Data Source
AI summary
A medium conveying apparatus includes a loading tray to place media, a feed roller to separate and sequentially feed the media placed on the loading tray, a motor to drive the feed roller, a sensor located on a downstream side of the feed roller in a medium conveying direction to detect a medium, and a processor to control the motor. In a separation period from a start of medium feeding by the feed roller to detection of a front edge of the first medium by the sensor, when feeding a first medium of a plurality of media placed on the loading tray, the processor controls the motor to rotate the feed roller at a constant speed, and when feeding a second or subsequent medium, the processor controls the motor to rotate the feed roller at a first speed and then at a second speed higher than the first speed.