Image Forming Apparatus Power Control via Memory Copy and Frequency Scaling

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Solution Overview

Problem

Current image forming apparatuses face challenges in reducing power consumption, particularly in standby mode, as they continue to consume power even when not actively performing tasks, which is becoming a regulatory concern due to increasing demands for energy efficiency.

Innovation Solution

The apparatus operates using volatile memory in normal mode and switches to power-saving modes by stages based on external signal input, duplicating information from volatile memory to internal memory, and adjusting operating frequencies to minimize power usage, with multiple power-saving modes allowing for progressive reduction in power consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If the image forming apparatus operates in normal mode using volatile memory, then processing speed and performance are maintained, but power consumption increases

Engineering Contradiction:
Improveprocessing speedVSAvoidpower consumption
Core Design Contradiction:
SpeedVSUse of energy by moving object

Solution Approach 1:

The apparatus dynamically switches between normal mode and multiple power saving modes based on external signal input status. The control part adjusts operating frequency and memory usage patterns in real-time, transitioning from high-performance volatile memory operations to low-power internal memory operations when no external signals are received within predetermined time periods

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes operational parameters by switching between different operating frequencies and memory configurations. In power saving modes, the apparatus operates at reduced frequencies and uses internal memory instead of volatile memory, thereby reducing power consumption while maintaining the ability to return to high-performance mode when needed

Inventive Principle:
Principle #35Parameter changes

2Use of energy by moving object

If the apparatus switches to power saving mode to reduce power consumption, then energy efficiency improves, but system responsiveness and performance decrease

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

Solution Approach 1:

The power management system is segmented into multiple distinct power saving modes (first, second, and third power saving modes) with progressively lower power consumption. This segmentation allows the apparatus to select the appropriate level of power reduction based on external signal activity, rather than forcing a single power saving state that would always compromise performance

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The control part monitors external signal input status in advance and switches to power saving modes before significant performance degradation occurs. By detecting periods of no external signal activity and proactively transitioning to lower-power modes, the system reduces power consumption while maintaining responsiveness during active operation

Inventive Principle:
Principle #10Preliminary action

3Use of energy by moving object

If multiple power saving modes are implemented with progressive frequency reduction, then power consumption is reduced, but device complexity increases

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

Solution Approach 1:

The control part continuously monitors external signal input status and uses this feedback to determine appropriate power saving mode transitions. The predetermined time period measurements provide feedback loops that automatically trigger frequency reduction and mode switching, reducing the need for complex manual control logic while achieving progressive power savings

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP2299681B1Image forming apparatus and power control method thereof
Publication Date: 2019.05.15 HP PRINTING KOREA CO LTD
  • EP2299681B1 patent drawingFigure 1
  • EP2299681B1 patent drawingFigure 2
  • EP2299681B1 patent drawingFigure 3

AI summary

An image forming apparatus includes a volatile memory and an SoC part. The SoC part includes an internal memory, a CPU for accessing the volatile memory in the normal mode; an interface part for receiving a external signal, and a control part for, when the interface part has no input during a first preset time, copying information stored to the volatile memory to the internal memory and converting to a first power saving mode to lower an operating frequency of the volatile memory and an operating frequency of the CPU, and when a normal mode switch signal is not input during a second preset time in the first power saving mode, controlling the CPU to access the information copied to the internal memory and converting to a second power saving mode to change the volatile memory to a self-refresh mode.