Image Forming Apparatus Duplex Speed Control
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Solution Overview
Problem
Existing electrophotographic image forming apparatuses face issues with temperature-related malfunctions and reduced printing quality due to high in-apparatus temperatures, particularly during duplex printing, where the heat retained by sheets leads to increased internal temperatures, necessitating frequent cooling operations that hinder printing efficiency.
Innovation Solution
The apparatus employs a dual-temperature sensing system with a first sensor inside and a second sensor outside the apparatus to differentiate between simplex and duplex printing modes, adjusting the conveyance speed accordingly, with higher speeds for simplex printing and lower speeds for duplex printing to manage temperature and reduce cooling operation frequency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If duplex printing is performed to increase productivity, then printing volume per unit time increases, but in-apparatus temperature rises more easily due to heat retained by sheets
Solution Approach 1:
The patent applies dynamics by making the sheet conveyance speed variable rather than fixed. The controller dynamically adjusts the conveyance speed based on real-time temperature sensor readings, reducing speed when temperature is high to minimize heat accumulation, and increasing speed when temperature is low to maintain productivity. This dynamic adjustment resolves the contradiction between maintaining high printing volume and controlling temperature rise.
Solution Approach 2:
The patent changes the parameter of sheet conveyance speed according to temperature conditions. By modifying this physical parameter (speed) based on temperature sensor feedback, the system can adapt to thermal conditions, reducing heat accumulation during duplex printing without permanently sacrificing printing volume. This parameter change allows the system to maintain both high productivity and temperature control.
2Reliability
If cooling operation is executed frequently to prevent temperature-related malfunctions, then reliability improves, but printing operation is restricted and productivity decreases
Solution Approach 1:
The patent applies preliminary action by proactively controlling sheet conveyance speed before temperature reaches critical levels that would trigger cooling operations. By continuously monitoring temperature and adjusting speed in advance, the system prevents temperature-related malfunctions from occurring in the first place, thereby maintaining both reliability and productivity without needing to execute frequent cooling operations that would restrict printing.
Solution Approach 2:
The patent implements feedback control by using temperature sensors to continuously monitor in-apparatus temperature and feeding this information back to the controller. The controller then adjusts sheet conveyance speed based on this feedback, creating a closed-loop system that maintains temperature within safe operating ranges. This feedback mechanism ensures reliability by preventing temperature-related malfunctions while maintaining productivity by avoiding unnecessary cooling operations.
3Temperature
If sheet conveyance speed is reduced to manage temperature during duplex printing, then temperature control improves, but printing time increases
Solution Approach 1:
The patent resolves this contradiction through dynamic speed adjustment. During duplex printing, when temperature rises, the controller reduces conveyance speed to manage heat accumulation. However, when temperature decreases or printing segments complete, the speed increases again to minimize total printing time. This dynamic approach ensures effective temperature control during critical thermal periods while maintaining overall printing efficiency.
Solution Approach 2:
The patent applies periodic action by implementing cyclic monitoring and adjustment of conveyance speed based on temperature fluctuations during duplex printing. The system periodically checks temperature conditions and adjusts speed accordingly, allowing temporary speed reductions for temperature control followed by speed increases to compensate for time loss. This periodic adjustment balances temperature management with printing throughput.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach effectively manages temperature fluctuations, minimizing the need for cooling operations and maintaining printing efficiency by optimizing sheet conveyance speeds based on printing modes, thus preventing temperature-related malfunctions and improving overall productivity.
Implementation Method 1
a first temperature sensor disposed inside a space between the plurality of frames, the first temperature sensor being configured to detect a first temperature inside the space between the plurality of frames by outputting a signal corresponding to the first temperature
Implementation Method 2
a second temperature sensor disposed outside the space between the plurality of frames, the second temperature sensor being configured to detect a second temperature outside the space between the plurality of frames by outputting a signal corresponding to the second temperature
Implementation Method 3
in at least one of a case where the first temperature is equal to or less than the inside threshold temperature and a case where the second temperature is equal to or less than the outside threshold temperature, control the image forming assembly to perform image formation on the sheet while conveying the sheet at the first conveyance speed
Data Source
AI summary
An image forming apparatus including a first temperature sensor inside a space between frames, a second temperature sensor outside the space between the frames, and a controller that, in a case where a first temperature by the first temperature sensor is higher than an inside threshold temperature, and a second temperature by the second temperature sensor is higher than an outside threshold temperature, performs simplex image formation at a first speed when simplex image formation is specified, and performs duplex image formation at a second speed lower than the first speed when duplex image formation is specified, and in at least one of a case where the first temperature is equal to or less than the inside threshold temperature and a case where the second temperature is equal to or less than the outside threshold temperature, performs image formation at the first speed.