Spectrometer Window Dirtiness Detection in Printers

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing image forming apparatuses face a reduction in color measurement precision due to ink residue on the color measurement sensor, which is not effectively detected and addressed.

Innovation Solution

An image forming apparatus equipped with a spectrometer that includes a window section, a dispersing element, and a light receiving element, which detects dirtiness on the window section by measuring light variations across multiple wavelengths and using reference values to determine ink residue and subsequent cleaning mechanisms to maintain precision.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If ink is ejected from the recording head, then image recording is achieved, but ink mist is generated and adheres to the color measurement sensor, reducing measurement precision

Engineering Contradiction:
Improveimage recording precisionVSAvoidcolor measurement precision
Core Design Contradiction:
Manufacturing precisionVSMeasurement precision

Solution Approach 1:

The patent extracts the detection function from the color measurement sensor by introducing a separate dirt detection sensor that specifically detects ink residue on the window section. This allows the color measurement sensor to focus on its primary function while the dedicated detection sensor monitors contamination, resolving the contradiction between image recording and measurement precision.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces a window section as an intermediary element between the light source and color measurement sensor. This window acts as a sacrificial surface that collects ink residue, protecting the color measurement sensor from direct contamination. The window can be cleaned separately without affecting the sensor, thus maintaining measurement precision while enabling continuous image recording.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Adaptability or versatility

If the color measurement sensor is exposed to ink mist, then it can detect color information, but ink adheres to the sensor and reduces measurement precision

Engineering Contradiction:
Improvecolor detection capabilityVSAvoidcolor measurement precision
Core Design Contradiction:
Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The window section serves as an intermediary barrier that the light beam passes through on its way to the color measurement sensor. Ink residue accumulates on this window rather than on the sensor itself, allowing the sensor to maintain its color detection capability while being protected from direct ink contamination.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces direct optical contact between the sensor and measurement target with an indirect system using a window section. This substitution allows the sensor to remain in a protected environment while still acquiring color information through the window, preventing ink adhesion to the sensor elements.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Measurement precision

If a cleaning mechanism is added to remove ink residue, then measurement precision is maintained, but device complexity increases

Engineering Contradiction:
Improvecolor measurement precisionVSAvoidsystem complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent uses a light detection approach to monitor ink residue, creating an optical copy or representation of the window's contamination state. By measuring changes in light transmission through the window, the system can detect dirt accumulation without physical contact, avoiding the need for complex mechanical cleaning mechanisms while maintaining measurement precision.

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The patent implements a feedback mechanism where the dirt detection sensor continuously monitors the window section's contamination level and provides information to the control unit. This feedback loop allows the system to maintain measurement precision by detecting when cleaning is needed, without requiring constant mechanical intervention or complex preventive mechanisms.

Inventive Principle:
Principle #23Feedback

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

Effectively detects and removes ink residue on the window section, thereby maintaining color measurement precision and preventing reductions in image quality.

Implementation Method 1

a spectrometer configured to disperse incident light

Methodology Applied
Scientific EffectDispersion: Dispersion (of waves)

Implementation Method 2

a window section that transmits the light

Methodology Applied
Scientific EffectLight transmission: Light

Implementation Method 3

a light receiving element that receives the light which is dispersed by the dispersing element

Methodology Applied
Scientific EffectPhotoelectric detection: Photoelectric Effect

Data Source

PatentEP3067673B1Image forming apparatus and dirtiness detection method
Publication Date: 2019.03.06 SEIKO EPSON CORP
  • EP3067673B1 patent drawingFigure 1
  • EP3067673B1 patent drawingFigure 2
  • EP3067673B1 patent drawingFigure 3

AI summary

A printer includes a printing section that ejects an ink, and a spectrometer that disperses incident light. The spectrometer includes a window section that transmits the light, an optical filter device, and a light receiving section. The optical filter device includes a variable wavelength interference filter as a dispersing element that disperses light transmitted by the window section. The light receiving section receives the light which is dispersed by the variable wavelength interference filter. A dirtiness of the window section is detected based on measured values corresponding to each of a plurality of wavelengths obtained by spectrally measuring light from a reference object, and reference values corresponding to each of the plurality of wavelengths.