Image Forming Device Sheet Conveyance Speed Control
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Solution Overview
Problem
In image forming devices, the conveyance rollers often fail to absorb the impact of thicker or larger sheets, leading to sheet slipping and abnormal noise during the aligning process.
Innovation Solution
Implementing a high-speed control mechanism where the conveyance speed of the second conveyance unit exceeds that of the first conveyance unit, generating a deflection in the sheet to absorb the impact when it collides with the resist rollers, thereby preventing slipping and noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the conveyance rollers operate at normal speed during aligning, then the alignment process is simple and straightforward, but the conveyance rollers cannot absorb the impact of thicker or larger sheets, causing sheet slipping and abnormal noise
Solution Approach 1:
The patent applies dynamics by making the conveyance speed variable rather than fixed. The conveyance rollers dynamically adjust their rotation speed based on the sheet type being conveyed. For thicker or larger sheets, the system automatically increases the conveyance speed to generate sufficient impact absorption capability, while maintaining normal speed for standard sheets. This dynamic adjustment resolves the contradiction by enabling reliable impact absorption without requiring a permanently complex high-speed mechanism.
Solution Approach 2:
The patent changes the operational parameter (conveyance speed) of the rollers based on detected sheet characteristics. By detecting whether the sheet is thick or large and accordingly adjusting the rotation speed parameter, the system achieves reliable impact absorption for problematic sheets while maintaining efficient operation for normal sheets. This parameter change approach allows the same hardware to handle varying conditions without requiring multiple specialized components.
2Object-affected harmful factors
If the conveyance speed is increased to absorb impact, then sheet slipping and noise are prevented, but the conveyance system becomes more complex requiring high-speed control
Solution Approach 1:
The patent implements feedback by detecting sheet characteristics (thickness, size) and using this information to control the conveyance roller speed. The detection unit provides real-time feedback about the sheet type, and the control unit adjusts the roller speed accordingly. This feedback mechanism prevents sheet slipping and noise by automatically increasing speed when needed, while avoiding unnecessary complexity by only activating high-speed mode when the feedback indicates problematic sheet conditions.
Solution Approach 2:
The system performs preliminary detection of sheet characteristics before the aligning process begins. By identifying whether the sheet is thick or large in advance, the control system can pre-adjust the conveyance roller speed to an appropriate level. This preliminary action prevents sheet slipping and noise from occurring in the first place, rather than requiring complex real-time corrections during the aligning operation.
3Reliability
If the conveyance rollers operate at high speed continuously, then impact absorption is maximized for all sheet types, but energy consumption increases and normal operation efficiency decreases
Solution Approach 1:
The patent applies local quality by tailoring the conveyance speed to the specific requirements of each sheet type. Instead of operating at high speed continuously for all sheets, the system uses high speed only locally when needed (for thick or large sheets) and maintains normal speed for standard sheets. This selective application of high-speed operation maximizes impact absorption reliability for problematic sheets while minimizing energy consumption during normal operation, resolving the contradiction between universal reliability and energy efficiency.
Data Source
AI summary
An image forming device and a sheet conveyance method are provided. An image forming device includes a feeder, a first conveyor, a second conveyor, and a conveyance controller. The feeder aligns a sheet and feeds the sheet to a transfer system that transfers an image to the sheet. The first conveyor is arranged at a first position on an upstream side of the feeder in a sheet conveyance direction and conveys the sheet to the feeder. The second conveyor is arranged at a second position on an upstream side of the first conveyor in the sheet conveyance direction and conveys the sheet to the first conveyor. The conveyance controller performs high-speed control for causing a conveyance speed of the second conveyor to exceed a conveyance speed of the first conveyor when a specific sheet different from a normal sheet is fed by the feeder.