Image Quality Stabilization in Printers After Energy-Save Mode

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Solution Overview

Problem

Conventional image forming apparatuses often force users to wait unnecessarily and consume image forming agents wastefully due to unnecessary imaging condition setting controls, which are triggered by short energy save mode periods, leading to reduced lifespan of visible image forming means and unstable image quality.

Innovation Solution

An image forming apparatus that executes imaging condition setting control only when significant environmental fluctuations are detected, using a CPU to assess temperature, humidity, and time differences to determine if a full or simplified process control is needed, thereby optimizing the measurement of imaging performance and reducing unnecessary process executions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If imaging condition setting control is executed immediately after power source ON or energy save mode reversion, then image quality stability is improved, but user wait time increases and image forming agents are consumed wastefully

Engineering Contradiction:
Improveimage quality stabilityVSAvoiduser wait time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The system performs preliminary assessment of environmental conditions (temperature, humidity) and power supply history before executing the full imaging condition setting control. This preliminary action filters out unnecessary controls by detecting when environmental conditions are stable and power cutoff was brief, thereby avoiding wasteful execution while maintaining quality stability when needed.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The invention changes the decision parameters for executing imaging condition setting control from a fixed time-based approach to a multi-parameter assessment including temperature, humidity, and power supply duration. By dynamically adjusting control execution based on these parameter changes, the system reduces unnecessary operations while maintaining image quality stability.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If imaging condition setting control is executed after medium power cutoff time, then environmental fluctuations are accounted for, but user wait time increases unnecessarily

Engineering Contradiction:
Improveimage quality stabilityVSAvoiduser wait time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The system dynamically adjusts its control execution strategy based on the duration of power cutoff and current environmental conditions. Instead of a fixed threshold approach, the control logic adapts its behavior by assessing whether the power cutoff duration and environmental changes warrant a full imaging condition setting control, thereby reducing unnecessary wait times while maintaining quality stability when environmental fluctuations occur.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system incorporates feedback from environmental sensors (temperature, humidity) and power supply history to determine whether imaging condition setting control is necessary. This feedback mechanism allows the system to detect when environmental conditions remain stable even after medium power cutoff, and accordingly skip unnecessary controls to reduce user wait time while maintaining image quality stability.

Inventive Principle:
Principle #23Feedback

3Reliability

If imaging condition setting control is executed after short energy save mode period, then imaging performance is maintained, but image forming agents are consumed wastefully

Engineering Contradiction:
Improveimaging performanceVSAvoidimage forming agents consumption
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The system performs preliminary assessment of power supply duration and environmental conditions before executing imaging condition setting control. When the power cutoff period is short and environmental conditions are stable, the preliminary assessment triggers a skipped control execution, thereby preventing wasteful consumption of image forming agents while maintaining imaging performance through alternative means.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

Instead of always executing the full imaging condition setting control, the system applies partial action by skipping the control when power cutoff is brief and environmental conditions are stable. This selective execution avoids excessive action (unnecessary control runs) that would waste image forming agents, while still maintaining sufficient imaging performance through the simplified approach.

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentEP1804129B1Control of image quality adjustment at warm-up after energy-saving modus in an image froming apparatus
Publication Date: 2008.10.15 RICOH CO LTD
  • EP1804129B1 patent drawingFigure 1
  • EP1804129B1 patent drawingFigure 2
  • EP1804129B1 patent drawingFigure 3~4

AI summary

A printer in which, while achieving a stabilization of image quality by process control processing, the generation of unnecessary wait time to the user, shortening of lifespan of the apparatus and needless consumption of toner caused by unnecessary execution of the process control processing can be better suppressed than in the prior art. An NVRAM (104d) serving as non-volatile information storage device in which stored information is retained even if the supply of power from an engine unit power source circuit (105) is cutoff is provided in an engine unit (104), and timing signal information output from a timing circuit (106c) when the process control processing is executed is stored in the NVRAM, the engine unit (104) being configured so as to judge, when power supply from the engine unit power source circuit (105) starts, whether or not process control processing is to be executed in accordance with the timing signal information stored in the NVRAM and the timing signal output from the timing circuit (106c).