Duplex Printing Roller Control for Interference-Free Paper Movement
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Solution Overview
Problem
Conventional image forming apparatuses experience prolonged print times due to the need to keep a second sheet of paper on standby while the duplex printing process is completed for a first sheet, leading to inefficiencies in the printing process.
Innovation Solution
The apparatus incorporates a control unit that manages the rotational direction of a driving roller to seamlessly move the first sheet between rollers while simultaneously moving the second sheet without interference, utilizing separate discharge and reversal paths and a sensor to guide the papers through different paths, allowing for continuous duplex printing without standby time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a single discharge roller is used to feed paper through the duplex print path, then the device complexity is reduced, but the productivity decreases due to standby time required for duplex printing
Solution Approach 1:
The discharge unit is segmented into multiple independent roller pairs (first discharge roller pair and second discharge roller pair) that can operate simultaneously and independently. This allows the first sheet to be fed through the duplex path while the second sheet is prepared, eliminating standby time and improving productivity without requiring complex coordinated control of a single roller system
Solution Approach 2:
The second sheet is preliminarily positioned and ready to be fed while the first sheet is still being processed through the duplex print path. The multiple roller pairs enable the second sheet to be prepared in advance and immediately fed when the first sheet completes its cycle, eliminating idle time and improving overall printing productivity
2Loss of time
If the second sheet is kept on standby during duplex printing of the first sheet, then the device complexity is minimized, but the loss of time increases
Solution Approach 1:
The printing process maintains continuity by using multiple discharge roller pairs that enable overlapping operations. While the first sheet undergoes duplex printing, the second sheet is simultaneously prepared and positioned, ensuring that the printing action continues without interruption or standby time, thereby improving productivity
Data Source
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AI summary
An image forming apparatus and an image forming method using the same. The image forming apparatus includes a discharge unit which has a driving roller rotating in forward and reverse directions and first and second driven rollers engaged with the driving roller to rotate together therewith, a duplex print unit which feeds the paper again to a developing unit so that the paper printed on a first surface is subsequently printed on a second surface, and a control unit which controls a rotational direction of the driving roller so as to move a first sheet of paper between the driving roller and the first driven roller and move a second sheet of paper between the driving roller and the second driven roller. Accordingly, the image forming apparatus is capable of controlling the forward movement of the second sheet of paper without interference with the reverse movement of the first sheet of paper, thereby decreasing a time required to perform duplex printing.