Dynamic Fixing Temperature Control for Image Forming Apparatus

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Solution Overview

Problem

Existing image forming apparatuses face productivity issues due to delayed start times in print operations caused by the time-consuming rasterizing process needed to set the fixing temperature for thermal fixing, which results in excessive energy consumption and reduced productivity, especially during high-volume print jobs.

Innovation Solution

An image forming apparatus that analyzes Page Description Language (PDL) data to acquire character number, spacing, and size information, allowing for early judgment on fixability at lower temperatures, thereby setting the fixing temperature promptly to reduce energy consumption while ensuring fixability, by comparing these parameters with reference values to determine if thermal fixing at a lower temperature will maintain image quality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the fixing temperature is set to the target temperature to ensure fixability under all print conditions, then fixability is improved, but electrical power consumption increases

Engineering Contradiction:
ImprovefixabilityVSAvoidelectrical power consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The fixing temperature is made dynamic rather than fixed. The control unit adjusts the fixing temperature based on the printing rate calculated from PDL data. When the printing rate is high (more toner deposited), the fixing temperature is set to the target temperature to ensure fixability. When the printing rate is low (less toner deposited), the fixing temperature is reduced to save energy. This dynamic adjustment resolves the contradiction between ensuring fixability and reducing power consumption.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The fixing temperature parameter is changed based on print conditions. Instead of using a single target temperature for all cases, the system calculates the printing rate from PDL data and adjusts the fixing temperature parameter accordingly. This allows the system to use lower temperatures for low-density prints (reducing power consumption) while maintaining the target temperature for high-density prints (ensuring fixability).

Inventive Principle:
Principle #35Parameter changes

2Use of energy by moving object

If the rasterizing process is performed to calculate printing rate for setting fixing temperature, then energy saving is improved, but start time of print operation is delayed

Engineering Contradiction:
Improveenergy savingVSAvoidstart time delay
Core Design Contradiction:
Use of energy by moving objectVSLoss of time

Solution Approach 1:

The system performs preliminary analysis of PDL data to calculate the printing rate before the actual print operation starts. By analyzing the PDL data structure (which contains information about image density and toner deposition) in advance, the control unit can determine the appropriate fixing temperature beforehand. This preliminary action allows the system to avoid time-consuming rasterizing processes during the print operation, thus reducing start time delay while still enabling energy-saving temperature control.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The invention extracts only the necessary information from PDL data (such as image region details and toner deposition patterns) to calculate the printing rate, rather than performing complete rasterization. By extracting key parameters from the PDL data structure directly, the system can estimate the printing rate quickly without converting the entire PDL data to raster format, thus reducing the time delay while maintaining energy saving benefits.

Inventive Principle:
Principle #2Taking out (Extraction)

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 approach enables earlier start times for print operations, preventing productivity decreases and achieving energy savings by promptly setting the fixing temperature based on PDL data analysis, ensuring both fixability and reduced energy consumption.

Implementation Method 1

thermally fixes the toner image

Methodology Applied
Scientific EffectThermal fixing: Heating

Data Source

PatentEP2829921B1Image forming apparatus, temperature control method, and temperature control program
Publication Date: 2019.10.16 KONICA MINOLTA INC
  • EP2829921B1 patent drawingFigure 1
  • EP2829921B1 patent drawingFigure 2
  • EP2829921B1 patent drawingFigure 3

AI summary

An image forming apparatus (1) forms a toner image of text on a recording sheet (S) based on PDL data prescribing text data and one or more print conditions thereof, and thermally fixes the toner image, and includes: condition acquisition unit (605) analyzing the PDL data to acquire, as the conditions, one or more of character number, character spacing, and line spacing from the PDL data; judgment unit (60) judging for each condition, by comparing the condition with reference value, the judgment indicating whether the condition is suitable for ensuring fixability of the toner image if thermally fixed at a temperature that is lower than predetermined temperature; and temperature control unit (80), when the judgment unit judges negatively for at least one condition, setting a fixing temperature for thermally fixing the toner image to the predetermined temperature, when the judgment unit judges affirmatively for all conditions, setting the fixing temperature to the lower temperature.