Image Processing Apparatus Toner Weight Control

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Solution Overview

Problem

Conventional color material control methods for color printers, such as those using cyan/magenta/yellow/black toners, fail to accurately manage toner amounts when the consumption varies across colors for the same density value, leading to potential image quality degradation and apparatus damage.

Innovation Solution

An image processing apparatus and method that utilize 1D-LUTs and toner weight concepts to dynamically adjust the toner amounts for each color, ensuring the total toner amount remains within safe limits while minimizing quality degradation, by using profiles like ICC profiles for color conversion and introducing 'toner weight' to account for varying consumption characteristics.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If the conventional color material control method is used, then the total toner amount can be controlled, but the control accuracy deteriorates when toner consumption varies across colors for the same density value

Engineering Contradiction:
Improvetotal toner amountVSAvoidtoner amount control accuracy
Core Design Contradiction:
Quantity of substanceVSMeasurement precision

Solution Approach 1:

The patent applies local quality by introducing color-specific toner weight values (C, M, Y, K) that reflect the actual toner consumption characteristics of each color. Instead of using a uniform toner weight assumption, the system uses different weight values for each color component to accurately calculate and control the total toner amount, thereby resolving the contradiction between controlling total toner quantity and maintaining control accuracy when colors have different consumption rates.

Inventive Principle:
Principle #3Local quality

2Reliability

If the toner amount is decreased to prevent fixing failure, then the reliability improves, but the image quality deteriorates

Engineering Contradiction:
Improvetoner fixing reliabilityVSAvoidimage quality
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The patent applies parameter changes by dynamically adjusting the toner amount for each color component based on its specific consumption characteristics. The system calculates the total toner amount using color-specific weight values and selectively adjusts the toner amount for each color, particularly increasing K (black) toner when the total approaches the limit, rather than uniformly decreasing all colors. This selective parameter adjustment maintains image quality while preventing fixing failures.

Inventive Principle:
Principle #35Parameter changes

3Quantity of substance

If the toner amount is uniformly decreased for all colors, then the total toner amount is controlled, but the image quality deteriorates due to unnecessary changes in C, M, and Y

Engineering Contradiction:
Improvetotal toner amountVSAvoidimage quality
Core Design Contradiction:
Quantity of substanceVSManufacturing precision

Solution Approach 1:

The patent applies segmentation by dividing the toner control into separate color-specific adjustments rather than a uniform approach. The system calculates and adjusts the toner amount for each color component (C, M, Y, K) independently based on its specific consumption characteristics, allowing selective adjustment of K toner while maintaining C, M, and Y at appropriate levels. This segmented control approach resolves the contradiction by controlling total toner quantity without unnecessarily degrading image quality through uniform decreases.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP2463719B1Image processing apparatus, image processing method and storage medium storing program thereof
Publication Date: 2020.04.01 CANON KK
  • EP2463719B1 patent drawingFigure 1
  • EP2463719B1 patent drawingFigure 2
  • EP2463719B1 patent drawingFigure 3

AI summary

Each pixel value which forms image data is converted into color material amount data using a color component-specific color material amount conversion LUT generated using information indicating that the amount of a color material consumed for the same density value varies in each individual color component. The sum of the converted color material amount data, and the limit value of the amount of the color material are compared, and the color material amount data is decreased so that the sum of the color material amount data becomes equal to or smaller than the limit value in a case where the sum of the color material amount data is larger than the limit value.