Image Forming Apparatus Power Management via Segmented Supply

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Solution Overview

Problem

Conventional image forming apparatuses face challenges in managing power efficiently, as they typically control power on/off for the entire system at once, leading to unnecessary power consumption and difficulties in low power operation, with the control unit always active even in power save mode, and reset signals generated by hardware can cause system lock-ups.

Innovation Solution

The image forming apparatus incorporates a power management unit that divides power supply to each function unit and control unit based on operation modes, using a switching unit to selectively turn on/off power to specific components, allowing for power saving by cutting off power to unnecessary units and reducing standby power to less than 1W.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If power is supplied to all components simultaneously in conventional image forming apparatus, then the system can be simplified in control structure, but power consumption increases and low power operation becomes difficult

Engineering Contradiction:
Improvepower consumptionVSAvoidcontrol structure
Core Design Contradiction:
Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The power supply system is segmented into multiple independent power sources, each dedicated to specific function units. The power management unit controls each power source separately, allowing individual components to be powered on or off based on operational needs, thereby reducing overall power consumption while maintaining functional independence.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The power supply configuration is made dynamic through the power management unit, which can adaptively adjust the power supply state of each function unit based on the current operation mode. This dynamic control enables the system to transition between different power states (full power, partial power, standby) without requiring complete system reconfiguration.

Inventive Principle:
Principle #15Dynamics

2Use of energy by moving object

If the control unit remains always active to control overall functions, then the system responds quickly to operations, but power consumption cannot be reduced in power save mode

Engineering Contradiction:
Improvepower consumptionVSAvoidsystem response
Core Design Contradiction:
Use of energy by moving objectVSSpeed

Solution Approach 1:

The control functionality is segmented and distributed to individual function units, each equipped with its own control capability. This allows the main control unit to be powered down or placed in low-power mode while individual function units can still operate independently or be quickly activated when needed, maintaining system responsiveness without continuous full-power operation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Function units are pre-configured with local control logic and can initiate operations independently without requiring constant communication with the main control unit. This preliminary preparation enables quick activation and operation even when the main control unit is in a low-power state, reducing the power-con responsiveness trade-off.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If hardware generates reset signals based on power supply output levels, then reset functionality is automatically provided, but system lock-up may occur

Engineering Contradiction:
Improvereset functionalityVSAvoidsystem lock-up
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The power management unit serves as an intermediary between the power supply and the function units, including the reset mechanism. Instead of direct hardware-based reset signal generation that can cause lock-up, the power management unit mediates the reset process by controlling the power supply to the reset unit, ensuring reset signals are generated only when power conditions are appropriate and stable, thereby preventing system lock-up while maintaining reliable reset functionality.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Ease of operation

If power is controlled on/off only for the power source converting basic DC to secondary DC, then the power supply structure is simplified, but efficient power management for individual components cannot be achieved

Engineering Contradiction:
Improvepower managementVSAvoidpower consumption
Core Design Contradiction:
Ease of operationVSUse of energy by moving object

Solution Approach 1:

The power supply system is divided into multiple independent power sources, with each power source dedicated to specific function units. This segmentation enables the power management unit to control power supply to individual components or groups of components independently, allowing efficient power management where only necessary components remain powered during partial operations or standby modes.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The power management unit provides universal control capability across all function units, managing multiple power sources and function units through a unified control interface. This multi-functional power management system can adapt to different operation modes and selectively power appropriate components, achieving both ease of operation and reduced power consumption.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP2312402B1Image forming apparatus and method of controlling power thereof
Publication Date: 2018.09.19 HP PRINTING KOREA CO LTD
  • EP2312402B1 patent drawingFigure 1
  • EP2312402B1 patent drawingFigure 2A
  • EP2312402B1 patent drawingFigure 2B

AI summary

An image forming apparatus includes a power supply unit to generate DC power, a plurality of function units to perform the functions of the image forming apparatus, a control unit to control the operation of a plurality of function units, a switching unit to receive DC power of the power supply unit and switch power provided to the control unit and each of a plurality of function units, and a power management unit to receive DC power of the power supply unit and to control a switching operation of the switching unit according to an operation mode of the image forming apparatus.