Miniaturized Spectral Colorimeter with Adjustable Linear Sensor

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Solution Overview

Problem

Image forming apparatuses face challenges in maintaining color consistency due to variations in drum sensitivity, toner charge capacity, and paper type, leading to tint deviations in color images, which are difficult to correct with existing spectral colorimetric systems due to the complexity of miniaturizing the apparatus while ensuring accurate positioning and orientation of optical components.

Innovation Solution

A miniaturized spectral colorimetric apparatus with a configuration that includes a light-emitting diode, light guide optical member, concave surface reflection type diffraction grating, and linear sensor, where the linear sensor is held outside the housing to allow for precise adjustment and bonding to the housing, ensuring accurate detection and correction of color tint deviations without compromising productivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If the illumination optical system, light guide optical system, and dispersing optical system are contained in one housing to miniaturize the apparatus, then the apparatus size is reduced, but the space for tool insertion and multi-axial adjustment becomes narrowly limited, making adjustment operations difficult and reducing productivity

Engineering Contradiction:
Improveapparatus sizeVSAvoidproductivity
Core Design Contradiction:
Volume of moving objectVSProductivity

Solution Approach 1:

The apparatus is divided into a housing and a separate detector unit. The detector unit can be adjusted independently outside the housing, allowing tool insertion and multi-axial adjustment without spatial constraints from other optical members. This segmentation enables both miniaturization of the main housing and efficient adjustment operations.

Inventive Principle:
Principle #1Segmentation

2Manufacturing precision

If the detector is fixed to a level baseplate with pre-positioning devices, then the detector is positioned in a defined position, but the detector cannot be adjusted for multi-axial positioning and orientation with high accuracy

Engineering Contradiction:
Improvepositioning accuracyVSAvoidadjustability
Core Design Contradiction:
Manufacturing precisionVSEase of operation

Solution Approach 1:

The detector unit is designed to be dynamically adjustable through multi-axial rotation mechanisms. The unit can be rotated around multiple axes to achieve precise orientation and positioning. After adjustment, the detector unit is fixed to the housing, combining the benefits of adjustability during operation with stability during use.

Inventive Principle:
Principle #15Dynamics

3Volume of moving object

If the spectral colorimetric apparatus is miniaturized, then the apparatus size is reduced, but the accuracy of adjustment of position and orientation of optical members becomes more difficult to achieve

Engineering Contradiction:
Improveapparatus sizeVSAvoidadjustment accuracy
Core Design Contradiction:
Volume of moving objectVSManufacturing precision

Solution Approach 1:

The adjustment process utilizes multi-axial rotation to provide additional degrees of freedom for positioning. By adjusting the detector unit's orientation around multiple axes, high positioning accuracy is achieved even in a miniaturized apparatus configuration. The multi-dimensional adjustment space compensates for the reduced physical size.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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

The solution enables precise color calibration and maintenance of color consistency in image formation by allowing for accurate adjustment and bonding of optical components, enhancing the productivity and accuracy of the spectral colorimetric apparatus while maintaining miniaturization.

Implementation Method 1

a light guide optical member for guiding to a diffraction grating a light beam reflected from a test surface

Methodology Applied
Scientific EffectLight guidance: Optical Fibre

Implementation Method 2

a dispersing optical system including a concave surface reflection type diffraction grating for acquiring a spectral intensity distribution by dispersing the guided light beam

Methodology Applied
Scientific EffectDiffraction: Diffraction

Implementation Method 3

a dispersing optical system including a concave surface reflection type diffraction grating

Methodology Applied
Scientific EffectReflection: Reflection

Implementation Method 4

a spectral colorimetric apparatus that detects a light beam dispersed using a reflection type diffraction element, using a plurality of photoelectric conversion elements arranged in an array

Methodology Applied
Scientific EffectPhotoelectric conversion: Photoelectric Effect

Data Source

PatentEP2869047B1Spectral colorimetric apparatus and image forming apparatus including the same
Publication Date: 2019.01.30 CANON KK
  • EP2869047B1 patent drawingFigure 1
  • EP2869047B1 patent drawingFigure 2A~2B
  • EP2869047B1 patent drawingFigure 3A~3B

AI summary

A spectral colorimetric apparatus includes a concave surface reflection type diffraction element configured to disperse an incident light beam; a sensor including a plurality of photoelectric conversion elements, wherein the plurality of photoelectric conversion elements is arranged in a direction parallel to a tangential line of a Rowland circle of the concave surface reflection type diffraction element, each photoelectric conversion elements being configured to receive the light beam dispersed by the concave surface reflection type diffraction element; a housing configured to support the concave surface reflection type diffraction element and the sensor; and a bonding portion provided on the housing, wherein the sensor is fixed to the housing with an adhesive provided between the bonding portion and the sensor. The bonding portion is provided only at a position corresponding to a center of the plurality of photoelectric conversion elements of the sensor in the direction in which the plurality of photoelectric conversion elements is arranged.