Dual Image Sensor for Reflected and Transmitted Light Detection

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Solution Overview

Problem

Existing image sensor devices for reading objects with both reflective and transmissive light portions require dedicated components for each type of light, leading to increased size and cost, as well as potential paper jams due to gaps and level differences between sensors and lighting units.

Innovation Solution

A compact image sensor device design featuring two identical image sensors rotated 180° relative to each other, with shared light guides and photoelectric conversion elements, allowing simultaneous detection of reflected and transmitted light information from both sides of the object, while maintaining a short conveying direction and minimizing space occupation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If dedicated lighting systems are installed for both reflected light information and transmitted light information, then detection capability is improved, but device size and cost increase

Engineering Contradiction:
Improvedetection capabilityVSAvoiddetector size
Core Design Contradiction:
Adaptability or versatilityVSVolume of stationary object

Solution Approach 1:

The patent merges the lighting system for reflected light reading and transmitted light reading into a single integrated lighting unit. The light guide serves dual purposes: illuminating the object for reflected light detection and providing transmission light for transmitted light detection. This consolidation eliminates the need for separate dedicated lighting systems, thereby reducing device size while maintaining full detection capability for both reflected and transmitted light information.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The lighting system is designed with multi-functionality to serve both reflected light reading and transmitted light reading operations. The same light guide and light source are utilized for both detection modes, making the lighting system universal rather than dedicated to a single function. This multi-functional design reduces the overall number of components and decreases the detector size while preserving adaptability for various detection specifications.

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

2Measurement precision

If dedicated lighting units are arranged on both sides of the object-to-be-read, then reading accuracy is improved, but gaps and level differences cause paper jams

Engineering Contradiction:
Improvereading accuracyVSAvoidconveying quality
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent combines multiple lighting units into a single integrated lighting system positioned on one side of the object-to-be-read. This merged structure eliminates the gaps and level differences that exist between separate dedicated lighting units arranged on both sides, thereby preventing paper jams while maintaining reading accuracy through the unified optical path and coordinated illumination.

Inventive Principle:
Principle #5Merging (Combining)

3Measurement precision

If separate detection mechanisms are installed for reflected light and transmitted light, then detection precision is improved, but device complexity and cost increase

Engineering Contradiction:
Improvedetection precisionVSAvoiddetector complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent merges the detection mechanisms for reflected light and transmitted light into a single integrated detection system. The image sensor and processing unit handle both reflected light information and transmitted light information from a single lighting system, reducing device complexity while maintaining detection precision through unified optical paths and coordinated signal processing.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The detection system is designed with universality to handle both reflected light and transmitted light detection functions. The same image sensor and processing unit are configured to process information from both detection modes, eliminating the need for separate dedicated detection mechanisms while preserving detection precision through multi-functional capability.

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

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 a small-sized, versatile image sensor device capable of detecting both reflected and transmitted light information from both sides of an object without increasing the size of the reader apparatus, reducing the risk of paper jams and improving conveying quality.

Implementation Method 1

a light guide 2, 3 having a circular cross section to emit light toward the object-to-be-read 17

Methodology Applied
Scientific EffectLight transmission: Light

Implementation Method 2

a light scattering portion 21, 22, 23 formed over a part of an outer periphery of the light guides 2, 3

Methodology Applied
Scientific EffectLight scattering: Scattering

Implementation Method 3

a photoelectric conversion element array 6 to convert the imaged optical information into an electrical signal

Methodology Applied
Scientific EffectPhotoelectric conversion: Photoelectric Effect

Data Source

PatentEP2911379B1Image sensor and image sensor device
Publication Date: 2020.02.26 MITSUBISHI ELECTRIC CORP
  • EP2911379B1 patent drawingFigure 1~2
  • EP2911379B1 patent drawingFigure 3A~4B
  • EP2911379B1 patent drawingFigure 5

AI summary

In order to obtain a small-sized and highly versatile image sensor and an image sensor device that are capable of obtaining reflected light information of both sides of an object-to-be-read and transmitted light information from the both sides of the object-to-be-read and have a short length in conveying direction while ensuring conveying quality, the image sensor and the image sensor device include: a lighting portion extending in a main scanning direction and emitting light to the object-to-be-read; a rod lens array for imaging light from the object-to-be-read; and a light receiving portion for converting the light imaged by the rod lens array to an electric signal. The lighting portion emits a normally directed light from the normal direction of the object-to-be-read to irradiate a first irradiation region of the object-to-be-read, and an inclined light inclined by a predetermined angle from the normal direction of the object-to-be-read to irradiate a second irradiation region being apart from the first irradiation region in a sub-scanning direction.