Fixing Section Cooling via Variable Conveyance Speed
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional image forming apparatuses fail to effectively cool the fixing section to a safe temperature during standby, leading to deformation or damage of roll sheets and increased waste due to prolonged natural cooling.
Innovation Solution
An image forming apparatus and method that control the fixing section to switch between press-contact and separated states, using rapid cooling by conveying the roll sheet at a first speed to dissipate heat and then natural cooling by reducing the conveying speed, allowing the fixing section to cool down efficiently.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the fixing section is kept at high temperature during standby, then the sheet can be quickly heated and pressurized for fixing during printing, but the sheet will deform or discolor due to prolonged exposure to heat
Solution Approach 1:
The patent applies periodic action by intermittently driving the conveying roller pair during standby periods. The roller drives the sheet through the fixing section at specified intervals (e.g., every 1-5 minutes) for short durations (e.g., 1-10 seconds), then stops. This periodic movement prevents continuous heat exposure while maintaining the sheet in a controlled state, preventing deformation and discoloration during standby without compromising quick fixing capability when needed.
2Object-affected harmful factors
If the temperature of the fixing section is decreased to prevent sheet deformation during standby, then the sheet will not deform or discolor, but the fixing section will take longer to cool down naturally
Solution Approach 1:
The patent applies continuity of useful action by using the sheet itself as a cooling medium. During standby, the sheet continuously passes through the fixing section while the conveying roller pair drives it at controlled intervals. This continuous passage allows the sheet to absorb heat from the fixing section and carry it away, providing active cooling rather than passive natural cooling. The process continues until the fixing section reaches a safe temperature, significantly reducing cooling time compared to natural cooling methods.
3Loss of time
If the conveying roller pair is driven at high speed during standby to cool the fixing section quickly, then the cooling effect is enhanced, but the sheet may become slack and deform
Solution Approach 1:
The patent applies dynamics by controlling the conveying roller pair to operate at variable speeds and intermittent intervals rather than continuous high speed. The roller drives the sheet through the fixing section at controlled speeds for short durations, then stops or reduces speed. This dynamic control maintains sheet tension and stability during cooling operations, preventing slack and deformation while still achieving effective heat transfer from the fixing section to the sheet for rapid cooling.
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
Combines rapid and natural cooling to rapidly decrease the fixing section's temperature, reducing waste generation and preventing sheet deformation, thereby improving operational efficiency and reducing waste.
Implementation Method 1
convey the recording medium at a first conveying speed from after completion of printing until a predetermined timing while the fixing section is being kept in the press-contact state, which makes heat of the fixing section transferred to the recording medium through thermal conduction
Data Source
AI summary
To provide an image forming apparatus and an image forming method which can rapidly decrease (cool) the temperature of a fixing section. The image forming apparatus of the invention includes a fixing section fixing a toner image on a sheet, and a controller performing switching control of press-contact state/separated state of the fixing section, and conveyance control of the sheet. The controller, after completion of printing, rapidly cools the fixing section while keeping it in the press-contact state by conveying the sheet at a first conveying speed. The controller naturally cools the fixing section by bringing it into the separated state at a predetermined timing to convey the sheet at a second conveying speed slower than the first conveying speed, and stops conveying it when the temperature of the fixing section becomes not higher than a predetermined temperature.