Duty Cycled Halogen Lamp Image Fixing Roller Temperature Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Image forming apparatuses face challenges in stabilizing the temperature of a fixing roller, particularly when dealing with varying heat requirements for different paper types, leading to flicker and potential filament damage due to inadequate control of halogen lamp heaters.
Innovation Solution
The apparatus employs two halogen lamp heaters with the same light distribution, a temperature sensor, and a controller that adjusts the duty cycle of the AC power supply to maintain a stable heat output, switching between the heaters based on detected temperature thresholds to prevent flicker and filament damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of stationary object
If the duty cycle of the application pattern is limited to a predetermined value or more to prevent chemical attack, then the life of the halogen lamp heater is extended, but the heater cannot be kept ON and needs to be turned off at appropriate timing to make the heat amount close to the required heat amount, which cannot stabilize the temperature of a fixing roller
Solution Approach 1:
The patent divides the heating function into multiple halogen lamp heaters (first heater, second heater, third heater) with different heat generation capacities. This segmentation allows the system to select appropriate heaters based on required heat amounts, enabling both prolonged heater life through duty cycle control and stable temperature maintenance by keeping at least one heater continuously ON or frequently cycling.
Solution Approach 2:
The patent changes the operational parameters of multiple heaters differently - the first heater operates with a duty cycle of a predetermined value or more to extend life, while the second and third heaters operate with different duty cycles to provide additional heat when needed. This parameter differentiation resolves the contradiction between extending heater life and maintaining temperature stability.
2Temperature
If multiple heaters are used in combination to continuously generate a predetermined heat amount, then the temperature of a fixing roller can be stabilized, but frequent switching between heaters may occur which causes flicker
Solution Approach 1:
The patent introduces a standby period after switching between heaters, during which no heater switching occurs. This preliminary action prevents frequent switching by establishing a minimum time interval between switchings, thereby eliminating flicker while maintaining temperature stability through the combined heat output of multiple heaters.
3Use of energy by moving object
If the number of selected half-waves of the AC waveform is small, then the effective value of drive voltage is smaller, but the temperature of a filament becomes low and chemical attack occurs on the filament
Solution Approach 1:
The patent segments the heating function across multiple heaters with different power ratings. By distributing the heating load among first, second, and third heaters, the system can operate each heater at adequate power levels (preventing chemical attack) while still achieving the required total heat output, thus resolving the contradiction between energy efficiency and filament protection.
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 solution effectively stabilizes the temperature of the fixing roller, reduces flicker, and extends the lifespan of the halogen lamp heaters by optimizing heat distribution and preventing chemical attack.
Implementation Method 1
a halogen lamp heater is used as a fixing heater
Implementation Method 2
a temperature sensor which detects a temperature of the fixing member
Data Source
AI summary
An image forming apparatus includes first and second heaters and a controller. The first and second heaters have a same light distribution and heat a roller of an image fixing unit. The second heater generates a less heat amount than the first heater. The controller applies a drive voltage to a heater of the heaters. When a heat amount generated by the second heater has increased to a first threshold value by the controller controlling the drive voltage, the controller switches the drive-voltage-applied heater from the second heater to the first heater. When a heat amount generated by the first heater has decreased to a second threshold value smaller than the first threshold value by the controller controlling the drive voltage, the controller switches the drive-voltage-applied heater from the first heater to the second heater.