Paper Feed System Speed Control for Uniform Sagging
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional paper feed systems in printers face issues with uneven paper sagging due to fluctuations in paper waiting positions, leading to inconsistent image formation and reduced productivity, as they do not account for variations in paper lengths and transfer speeds.
Innovation Solution
A paper feed system with a first and second mechanism, where a paper edge detector is used to control the speed of paper transfer, adjusting the speed based on detected paper edges and using image forming pulse signals to synchronize paper delivery, allowing for uniform sagging and improved productivity by optimizing paper intervals and transfer speeds.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the paper feed rollers are driven to rotate for only a predetermined angle to match printing speed, then the paper transfer timing is controlled, but the waiting positions of papers fluctuate causing non-uniform sagging and image position shifts
Solution Approach 1:
The system performs preliminary action by rotating the paper feed rollers before the resist roller starts rotating, causing the paper to sag in advance. This preliminary sagging compensates for the oblique feed and ensures uniform paper positioning despite variations in waiting positions, thereby maintaining consistent image formation.
Solution Approach 2:
The system uses a paper position detector to detect the waiting position of each paper and provides feedback to the control unit. The control unit then adjusts the rotation angle of the paper feed rollers based on this feedback, ensuring that each paper is fed at the correct angle to achieve uniform sagging and consistent image positioning.
2Manufacturing precision
If the resist roller transfers paper at a constant speed equal to image forming section speed, then image formation is synchronized, but paper intervals are widened when printing speed is slow, reducing productivity
Solution Approach 1:
The resist roller's rotation angle is made dynamic rather than fixed. The control unit adjusts the rotation angle of the resist roller based on the detected waiting position of each paper and the printing speed requirements. This dynamic adjustment allows the system to maintain synchronization with the image forming section while optimizing paper intervals for different printing speeds, thereby improving productivity without sacrificing image formation quality.
3Shape
If paper feed rollers rotate for a while before resist roller starts to overcome paper inclination, then paper sagging occurs to correct oblique feed, but paper supply timing varies causing image position shifts
Solution Approach 1:
The paper position detector detects the actual waiting position of each paper and provides feedback to the control unit. Based on this feedback, the control unit precisely controls the rotation angle of the paper feed rollers, ensuring that each paper sags by the correct amount to achieve proper alignment without causing variations in paper supply timing, thereby maintaining consistent image positioning.
Solution Approach 2:
The system changes the rotation angle parameter of the paper feed rollers based on the detected paper waiting position. By adjusting this parameter dynamically, the system ensures that each paper is fed at the optimal angle to achieve uniform sagging and correct alignment, preventing image position shifts while maintaining proper paper orientation.
Data Source
AI summary
In a paper feed system where a first paper feed mechanism takes out and transfers one by one a plurality of papers placed on a paper feed table in a stack and a second paper feed mechanism transfers the papers transferred by the first paper feed mechanism to an image forming section at a predetermined timing. A paper edge detector is provided between the first and second paper feed mechanisms to detect an edge of the paper, and the first paper feed mechanism is controlled to transfer the papers at a first speed and then at a second speed not higher than the first speed when the paper edge detector detects the leading edge of the paper, the second speed being determined on the basis of the timing at which the leading edge of the paper is detected.