Infrared Multi-feed Detection in Reading Devices

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Solution Overview

Problem

Conventional reading devices face challenges in accurately detecting multi-feed states, particularly when sheets of paper are stacked, as the accuracy of detecting such states decreases when using visible wavelength regions.

Innovation Solution

A reading device that illuminates objects with invisible light, captures images using invisible wavelength ranges, and detects states based on differences between reading values and reference values, enhancing the detection of multi-feed conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If visible wavelength light is used for illumination and image capture, then the reading device can capture images in the visible spectrum, but the accuracy of detecting multi-feed states decreases

Engineering Contradiction:

Improvedetection accuracy of multi-feed stateVSAvoidwavelength range limitation

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent changes the wavelength parameter of the light used for illumination and image capture from visible wavelength to invisible wavelength (specifically infrared wavelength of 700nm or more). This parameter change enables sufficient difference in reflectance levels between single-feed and multi-feed states, thereby improving detection accuracy without increasing device complexity

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent extends the detection capability from the visible wavelength dimension to the invisible wavelength dimension (infrared region). By operating in this additional spectral dimension, the system achieves better differentiation of paper stack states that are not distinguishable in the visible range

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Measurement precision

If invisible wavelength light is used for illumination and image capture, then the accuracy of detecting multi-feed states improves, but the reading device requires capability to handle invisible wavelengths

Engineering Contradiction:

Improvedetection accuracy of multi-feed stateVSAvoidwavelength range capability

Core Design Contradiction:

Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The patent modifies the operational parameter of the reading device by changing the wavelength range from visible to invisible (infrared). This enables the device to detect multi-feed states with high accuracy while maintaining compatibility with standard reading device architectures

Inventive Principle:

Principle #35Parameter changes

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 effectively improves the accuracy of detecting multi-feed states by utilizing invisible wavelengths, which provides a sufficient difference in reflectance levels, allowing for precise identification even when visible wavelength methods fail.

Implementation Method 1

an imaging device to capture an image of the light reflected from the object to be read

Methodology Applied

Scientific EffectReflection: Reflection

Data Source

PatentUS11770487B2Reading device, image forming apparatus, and state detection method to detect a multi-feed state of an object using reflected light in a visible wavelength and an invisible wavelength and comparing reading value results to references associated with the invisible and visible wavelength reference values

Publication Date: 2023.09.26 RICOH CO LTD

AI summary

A reading device includes an illuminator, an imaging device, a memory, and a detector. The illuminator illuminates an object to be read with light in an invisible wavelength range. The imaging device captures an image of the light reflected from the object to be read, within the invisible wavelength range. The memory holds a reference value of the object to be read. The detector detects a state of the object to be read, based on a difference between a level of a reading value of an invisible image captured within the invisible wavelength range and a level of the reference value.