Document Feeder Bidirectional Switchback Drive Control
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Solution Overview
Problem
Existing document feeders for double-sided reading in image forming apparatuses face challenges in ensuring seamless connection and disconnection of driving force transmission during the switchback process, leading to potential errors and document misalignment.
Innovation Solution
A document feeder with a bidirectional feed system that includes a drive system, a first transmitting assignment for forwarding driving force, and a second transmitting assignment for disconnecting it, controlled by a controller to ensure precise transmission and connection of driving force based on the drive system's rotation, preventing document misalignment and errors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a bidirectional feed system is used for double-sided reading, then both sides of the document can be scanned consecutively with leading and trailing ends switched, but the connection and disconnection of driving force transmission during the switchback process becomes unreliable
Solution Approach 1:
A one-way clutch mechanism is introduced as an intermediary component between the drive system and the bidirectional feed system. This clutch acts as a mediator that automatically controls the connection and disconnection of driving force transmission during the switchback process, ensuring reliable operation without requiring complex control systems. The one-way clutch allows rotation in the forward direction for normal feeding while preventing reverse rotation during switchback, thereby maintaining driving force transmission reliability.
2Adaptability or versatility
If the discharge rollers reversely rotate to feed the document into the bidirectional feed path, then the leading and trailing ends of the sheet are switched, but this may cause document misalignment and reading errors
Solution Approach 1:
The system performs preliminary positioning actions before the actual switchback feed. The one-way clutch mechanism is pre-configured to engage at specific rotational positions, ensuring that the document is properly aligned and positioned before the reverse rotation begins. This preliminary preparation prevents misalignment and positioning errors that would otherwise occur during the switchback process.
Solution Approach 2:
Position detection mechanisms provide feedback control during the switchback operation. Sensors detect the position of the document and the rotational state of the discharge rollers, allowing the control system to make real-time adjustments to maintain accurate positioning. This feedback ensures that the document remains properly aligned even during the complex reverse rotation and switchback maneuvers.
Data Source
AI summary
A document feeder includes a bidirectional feed path having both ends connected to predetermined positions of the bidirectional feed path, respectively. A document is fed from a downstream side of the image reading position to an upstream side with leading end and trailing end being reversed. The driving force is not transmitted when the rotation of the rotating member of the driving source is switched from one direction to the other, while the driving force is transmitted when an actuator is operated based on the driving system being rotated in the other direction. The actuator is actuated when the driving system is rotated in the other direction and the document is drawn in the bidirectional feed path. If the rotated amount of the driving source during the actuation of the actuator is less than a predetermined value, the actuator is actuated by a predetermined period.