Fixing Device Standby Temperature Control for Image Formers
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Solution Overview
Problem
The suspension standby mode in image forming apparatuses with locally heated fixing devices results in a slow increase in fixing device temperature when transitioning from standby to printing, leading to increased First Print Output Time (FPOT) and First Copy Output Time (FCOT).
Innovation Solution
Setting the standby temperature in the suspension standby mode higher than the printing temperature, and implementing a printing preparation mode where the heat source is kept on and the fixing motor rotates at a slower speed to rapidly increase the fixing device temperature.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If suspension standby is employed with local heating, then operating noise is reduced and degree of silence is improved, but the temperature of the fixing device cannot be increased in a short period of time
Solution Approach 1:
The patent applies preliminary action by pre-heating the fixing device to a standby temperature (100°C to 150°C) before printing operations begin. This preliminary heating maintains the fixing belt at a temperature closer to the printing temperature, so when printing starts, the temperature needs to be increased from a higher baseline rather than from ambient temperature, significantly reducing the time to reach printing temperature while still allowing the motor to remain stopped during standby.
2Use of energy by stationary object
If the heat application source heats the fixing device locally during suspension standby, then power consumption is reduced, but heat is radiated from non-heated portions causing temperature decrease
Solution Approach 1:
The patent applies parameter changes by optimizing the standby temperature range (100°C to 150°C) and the heating power range (30% to 70% of maximum power). By carefully selecting these parameters, the system maintains enough heat in the fixing belt during local heating to minimize temperature drop from radiation, while keeping power consumption low. The control unit adjusts heating power based on elapsed time and temperature conditions to balance these competing requirements.
3Speed
If rotation standby is used to warm the whole fixing device, then temperature increase speed is improved, but operating noise is generated due to continuous rotation
Solution Approach 1:
The patent resolves this contradiction by performing preliminary heating of the fixing device before printing operations. During standby, the motor remains stopped (no noise) but the fixing belt is heated to 100°C to 150°C through local heating. When printing begins, the motor starts and rapidly increases temperature from this elevated baseline. This preliminary action eliminates the need for continuous rotation during standby while still achieving fast temperature increase when needed.
4Use of energy by stationary object
If suspension standby with local heating is used, then power consumption during standby is reduced, but FPOT and FCOT increase due to slow temperature increase
Solution Approach 1:
The patent applies preliminary action by maintaining the fixing belt at a standby temperature of 100°C to 150°C during suspension standby with local heating. This preliminary maintenance of elevated temperature reduces the temperature differential that needs to be overcome when printing starts. Combined with applying 30% to 70% heating power during standby, this ensures that when printing begins, the temperature can be rapidly increased from this intermediate state, reducing FPOT and FCOT while maintaining low standby power consumption.
Solution Approach 2:
The patent applies parameter changes by optimizing the standby temperature range (100°C to 150°C) and heating power range (30% to 70%). These parameter adjustments balance the competing requirements of low power consumption during standby versus fast temperature increase when printing begins, directly addressing the FPOT and FCOT issue while maintaining energy efficiency.
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 allows for a quicker temperature increase of the fixing device from standby to printing, thereby reducing FPOT and FCOT, and improving overall printing efficiency.
Implementation Method 1
heat application source heats a fixing device locally
Implementation Method 2
heat application source heats a portion of fixing belt 51
Implementation Method 3
heat source 56 heats a portion of fixing belt 51
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A fixing device (17) of an image forming apparatus includes: a fixing belt (51); a heat source (56) that heats a portion of the fixing belt (51); and a pressure roller (58) that forms a nip between the pressure roller (58) and the fixing belt (51) and that transports a sheet. In the heat source (56), a standby temperature (setting temperature in a suspension standby mode) in a standby state in which rotation of the fixing belt (51) is suspended is set to be higher than a printing temperature in a printing state.