Polarized Light-Reading Element for Compact Optical Sensors

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional optical information-reading devices face challenges in size reduction, high-resolution capabilities, and cost efficiency due to the need for refractive lenses and precise alignment of light-emitting and light-receiving elements, which increases production costs and adjustment man-hours.

Innovation Solution

The proposed solution involves a configuration where a light-emitting element and a light-receiving element are laminated on a glass substrate with a polarizing plate, using a quarter-wave plate to change the polarization of light, allowing for flexible distance settings and eliminating the need for refractive lenses, thereby reducing size and production costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If refractive lenses are provided to refract outgoing light and returning light, then the light can be properly directed between the light-emitting element and light-receiving element, but the cost increases due to the need for expensive refractive lenses

Engineering Contradiction:
Improvelight direction controlVSAvoidproduction cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent extracts and eliminates the refractive lenses from the optical system. Instead of using lenses to refract light, the invention uses a planar configuration where the light-emitting element and light-receiving element are arranged on the same substrate plane, allowing light to travel directly without requiring expensive refractive optical components.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the mechanical/optical system of refractive lenses with a geometric arrangement of light-emitting and light-receiving elements on the same plane. This substitution eliminates the need for complex refractive optics while maintaining the functional requirement of directing light between components.

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

2Reliability

If the light-emitting element and light-receiving element are inclined against the substrate plane to achieve proper light reflection, then light can be guided correctly, but dedicated jigs and inspection devices are required increasing production complexity and cost

Engineering Contradiction:
Improvelight path alignmentVSAvoidproduction setup complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent uses asymmetric arrangement of the light-emitting element and light-receiving element on the substrate plane. By positioning these elements at specific asymmetric locations rather than using symmetric inclined configurations, the design achieves proper light path alignment while maintaining a simple planar structure that does not require complex production jigs or inspection devices.

Inventive Principle:
Principle #4Asymmetry

3Reliability

If the distance between the substrate and read object is increased to accommodate refractive lenses, then proper light refraction can be achieved, but the device size increases which is unfavorable for size reduction requirements

Engineering Contradiction:
Improvelight refraction effectivenessVSAvoiddevice size
Core Design Contradiction:
ReliabilityVSVolume of moving object

Solution Approach 1:

The patent extracts and removes the refractive lenses from the system, eliminating the need for increased distance between the substrate and read object. The planar configuration allows light to travel directly between the light-emitting element and light-receiving element on the same plane, enabling compact device sizing while maintaining effective light transmission.

Inventive Principle:
Principle #2Taking out (Extraction)

4Volume of moving object

If the distance between the light-emitting element and light-receiving element is reduced for size reduction, then device size decreases, but part of the outgoing light directly reaches the light-receiving element causing reading errors

Engineering Contradiction:
Improvedevice sizeVSAvoidreading accuracy
Core Design Contradiction:
Volume of moving objectVSManufacturing precision

Solution Approach 1:

The patent applies local quality by introducing a light-shielding structure at specific locations between the light-emitting element and light-receiving element. This localized shielding blocks the direct path of outgoing light that would otherwise reach the light-receiving element, while allowing reflected light from the read object to reach the sensor, thereby maintaining reading accuracy in the compact configuration.

Inventive Principle:
Principle #3Local quality

5Manufacturing precision

If directional objects or light shielding walls are provided to restrict light directions, then direct light reaching the light-receiving element can be blocked, but the cost increases further

Engineering Contradiction:
Improvelight direction controlVSAvoidproduction cost
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent uses a simple, inexpensive light-shielding structure rather than complex directional objects or expensive light-shielding walls. The shielding is implemented as a basic geometric feature on the substrate or as a simple opaque element that blocks direct light paths without requiring precision manufacturing or expensive materials, thereby controlling light direction while minimizing cost increase.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

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 configuration enables size reduction, flexible distance settings, and improved information-reading accuracy, allowing for high-resolution information capture while reducing production costs and adjustment complexities.

Implementation Method 1

a polarizing plate 11c, and a light-receiving element 11b

Methodology Applied
Scientific EffectPolarization: Polarisation

Implementation Method 2

using a quarter-wave plate to change the polarization of light

Methodology Applied
Scientific EffectPolarization change: Polarisation

Implementation Method 3

a device to which optical reflection has been applied is particularly known

Methodology Applied
Scientific EffectOptical reflection: Reflection

Data Source

PatentEP2963907B1Information-reading component and information-reading device utilizing same
Publication Date: 2018.08.01 SHINANO KENSHI CO LTD
  • EP2963907B1 patent drawingFigure 1~2
  • EP2963907B1 patent drawingFigure 3~4
  • EP2963907B1 patent drawingFigure 5~6

AI summary

The purpose of the present invention is to provide an information-reading element, which can be made small and allows the number of adjustment steps to be reduced, and an information-reading device. An information-reading element (10a) equipped with a light-emitting element (11a), which serves as a polarized light-emitting part for emitting polarized light as outgoing light, and a light-receiving element (11b), which serves as a polarized light-receiving part for receiving the polarized light as returning light after the polarized light is reflected off a reflecting plate (13a), said reflecting plate being a target object from which information is to be read, wherein the light-emitting element 11a and the light-receiving element (11b) have different polarization characteristics from each other.