Heater Voltage Drop Detection for Fixing Device Abnormality
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Solution Overview
Problem
Conventional image forming apparatuses cannot reliably distinguish between failures in the heater and sensor of the fixing device, leading to unclear determination of the actual cause for a non-functioning fixing device.
Innovation Solution
The apparatus includes a control section that detects voltage changes when the heater is turned on and off, determining abnormality based on a threshold value, distinguishing between heater and sensor failures by measuring voltage drop and temperature detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If temperature monitoring method is used to detect fixing device damage, then damage detection capability is improved, but ability to distinguish heater failure from sensor failure deteriorates
Solution Approach 1:
The failure detection method is segmented into two independent detection dimensions: temperature monitoring (via temperature sensor) and power consumption monitoring (via voltage sensor). This segmentation allows the system to independently evaluate both the thermal state and electrical state of the heater, enabling differentiation between heater failures (affecting power consumption) and sensor failures (affecting temperature readings)
2Device complexity
If conventional temperature monitoring is used, then simplicity of detection method is improved, but diagnostic precision between heater and sensor failure deteriorates
Solution Approach 1:
The control unit is designed to perform multiple functions: it controls the heater operation, monitors temperature via the temperature sensor, monitors voltage via the voltage sensor, and performs diagnostic analysis by comparing both data streams. This multi-functionality allows a single control unit to provide both operational control and precise failure differentiation without adding separate dedicated diagnostic hardware
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
Accurately determines abnormalities in the heater or temperature sensor, allowing for timely notification and maintaining the apparatus in a usable state by differentiating between the two potential causes of failure.
Implementation Method 1
a heat generation section (heat generator) generates heat when the heater is turned on
Data Source
AI summary
An image forming apparatus includes a heater, a fixing device, and a controller. The heater includes a heat generator that generates heat when the heater is turned on. The fixing device may fix a developer image on a surface of an image forming medium using the heat from the heat generator. The controller detects a voltage of a power supply for supplying electric power to the heater, and determines an occurrence of an abnormality in the heater if a voltage drop amount at the time the heater is turned on as compared to a case in which the heater is turned off is smaller than a first threshold value.