Sensor Apparatus for Recording Paper Brand Identification

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Solution Overview

Problem

Conventional image forming apparatuses face difficulties in precisely identifying the brand of recording paper due to variations in smoothness, thickness, and other properties, leading to suboptimal image formation and increased user complexity in setting appropriate conditions.

Innovation Solution

The implementation of a sensor apparatus with a third detection unit and a mechanical thickness sensor, utilizing a surface emitting laser array and multiple photosensors to measure regular and diffuse reflection light, as well as transmission light, to determine the brand of recording paper by analyzing three-dimensional coordinates of signal values, thereby improving identification accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional reflection optical sensors are used to identify recording material, then the identification process is simple, but the identification precision is insufficient to distinguish paper brands with similar smoothness but different thickness

Engineering Contradiction:
Improveidentification precisionVSAvoidsensor structure complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent divides the detection function into multiple independent detection units: first detection unit for regular reflection light, second detection unit for diffuse reflection light, and third detection unit for transmission light. Each unit uses separate photosensors to measure specific optical properties, allowing precise differentiation of paper brands through combined analysis of multiple measurement dimensions.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent transitions from two-dimensional detection (regular and diffuse reflection only) to three-dimensional detection by adding transmission light measurement. This dimensional expansion creates a more comprehensive measurement space that can distinguish paper brands with similar surface properties but different thickness or density characteristics.

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

2Measurement precision

If multiple detection units are added to improve identification accuracy, then the measurement precision increases, but the device complexity increases

Engineering Contradiction:
Improvebrand identification accuracyVSAvoidnumber of detection units
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent designs each detection unit to serve multiple purposes: the regular reflection detection identifies surface glossiness, the diffuse reflection detection identifies surface smoothness, and the transmission light detection identifies paper density and thickness. By combining these universal detection capabilities, the system achieves comprehensive paper brand identification without requiring specialized sensors for each property.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent merges the detection functions of multiple optical measurement units into a single integrated sensor apparatus. The controller combines signals from all detection units to perform comprehensive analysis, reducing the need for separate independent systems while achieving high-precision multi-parameter measurement for accurate paper brand identification.

Inventive Principle:
Principle #5Merging (Combining)

3Reliability

If detailed conditions are set for every paper brand to achieve high-quality image formation, then the image quality improves, but the user operation becomes complicated and time-consuming

Engineering Contradiction:
Improveimage qualityVSAvoidsetting operation complexity
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent enables the image forming apparatus to automatically identify the paper brand by analyzing optical properties through multiple detection units. The controller autonomously determines the appropriate image formation conditions based on the identified paper type, eliminating the need for manual setting by the user and ensuring optimal quality without requiring user knowledge of paper specifications.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system implements automatic feedback control by measuring the actual optical properties of the loaded paper through multiple detection units and adjusting the image formation conditions accordingly. This closed-loop approach ensures that the correct settings are applied for each paper brand, maintaining high image quality while simplifying user operation through automated adaptation.

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

This solution enables precise identification of recording paper brands, enhancing image quality by accounting for thickness, smoothness, and density, and simplifying user settings, reducing errors and manual complexity in image formation.

Implementation Method 1

a first photosensor arranged on an optical path of light that has been emitted from the light source and then is reflected by regular reflection on the recording paper

Methodology Applied
Scientific EffectReflection: Reflection

Implementation Method 2

a third photosensor arranged on an optical path of light that has passed through the recording paper

Methodology Applied
Scientific EffectLight transmission: Light

Data Source

PatentEP2843475B1Sensor apparatus and image forming apparatus incorporating same
Publication Date: 2022.01.12 RICOH CO LTD
  • EP2843475B1 patent drawingFigure 1
  • EP2843475B1 patent drawingFigure 2
  • EP2843475B1 patent drawingFigure 3~4

AI summary

A sensor apparatus (100, 200, 300, 2245) includes an irradiation system (11, 12) with a light source (11) configured to emit linearly polarized light of a first polarization direction onto a sheet-like object (M), in a direction oblique to a direction orthogonal to a surface of the object (M), a first photodetector (15) arranged on an optical path of light that is emitted from the irradiation system (11, 12) and then is reflected at the object (M) by regular reflection, a first optical element (14), arranged on an optical path of light reflected by diffuse reflection from an incidence plane of the object (M), configured to transmit linearly polarized light of a second polarization direction that is orthogonal to the first polarization direction, a second photodetector (13) configured to receive light passed through the first optical element (14), and a detection unit (13t) configured to detect at least one of basis weight and thickness of the object (M).