Power Supply Cooling Control in Sleep-Mode Image Forming Units
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Solution Overview
Problem
Existing image forming apparatuses face challenges in protecting the power source device from overcurrent conditions during power off or sleep modes without increasing cost or space, especially when using a single AC-DC converter system.
Innovation Solution
The apparatus includes a power source device that switches between first and second output modes, utilizing a temperature detecting means to control a cooling means and signal output circuit, allowing for efficient cooling and overcurrent protection without additional space or cost, by switching to a lower voltage mode when temperature exceeds a threshold.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an overcurrent protection circuit is provided on the secondary side to protect during power off/sleep modes, then device protection is improved, but cost and space increase
Solution Approach 1:
The existing primary side overcurrent protection circuit is made to serve dual purposes: protecting during normal operation mode and protecting during power off/sleep modes. The control unit leverages the same protection circuitry to detect abnormal currents regardless of operational mode, eliminating the need for separate protection circuits.
Solution Approach 2:
The control unit continuously monitors the output current through the existing protection circuit and uses this feedback information to determine whether to switch between operation mode and power off mode. This feedback mechanism enables the system to respond to overcurrent conditions dynamically without requiring additional hardware.
2Use of energy by moving object
If the AC-DC converter output is reduced to medium voltage in power off/sleep modes for energy saving, then energy consumption is reduced, but overcurrent protection capability is lost
Solution Approach 1:
The system dynamically switches between two operational states: during normal operation, the AC-DC converter operates at high voltage (24V) for full performance; during power off/sleep modes, it switches to medium voltage (6-12V) for energy saving. The control unit manages this dynamic transition and ensures protection functionality is maintained in both states.
Solution Approach 2:
The output voltage parameter of the AC-DC converter is changed based on operational mode. In power off/sleep modes, the voltage is reduced from 24V to 6-12V to decrease power consumption. The control unit monitors current conditions and can switch back to high voltage mode when protection is needed, demonstrating parameter-based adaptive operation.
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 configuration effectively protects the power source device from overcurrent conditions during power off or sleep modes, ensuring safety and preventing device failure while maintaining cost-effectiveness and space efficiency.
Implementation Method 1
a cooling means configured to cool the power source device
Implementation Method 2
a temperature detecting means disposed in the secondary side of the power source device and configured to detect a temperature of the power source device
Implementation Method 3
a power source device configured to convert an AC voltage of a primary side to a DC voltage and supply to a load of a secondary side
Data Source
AI summary
An image forming apparatus operable in a first mode operated in a first voltage and in second mode operated in a second voltage lower than the first voltage. The apparatus includes a power source device, cooling fan, temperature detector, controller and a recovery circuit. The recovery circuit outputs a signal when a detected temperature of the temperature detector is equal to a predetermined temperature or higher. The controller includes a port for detecting the signal outputted from the recovery circuit in the second mode. Upon detecting that the signal is inputted to the port from the recovery circuit in the second mode, the controller switches the power source device to in a first output mode for outputting the first voltage from in a second output mode for outputting the second voltage and operates the cooling fan to cool the power source device.