Light Guide Member Illumination Uniformity Assembly

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Solution Overview

Problem

Conventional image capturing apparatuses face challenges in miniaturization and easy assembly due to the need for multiple light-emitting devices and distance sensors, which increases size, complexity, and assembly time, while also being costly and prone to defects.

Innovation Solution

The design incorporates a ring-shaped light guide member to direct light from peripheral light-emitting devices to an image capturing range, combined with a compact optical unit and a hood to block extraneous light, allowing for a miniaturized and easily assembled apparatus with fewer adhesive points, using a single circuit board for all components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If multiple light-emitting devices and distance sensors are disposed apart from each other to achieve uniform illumination and accurate distance measurement, then illumination uniformity and measurement accuracy are improved, but device size and structural complexity increase

Engineering Contradiction:
Improveillumination uniformityVSAvoidstructural complexity
Core Design Contradiction:
Illumination intensityVSDevice complexity

Solution Approach 1:

The patent combines multiple light-emitting devices (first and second light-emitting devices) and the distance sensor into a single integrated housing structure. The light guide member integrates light from multiple sources while the hood provides unified external protection, reducing structural complexity while maintaining illumination uniformity and measurement accuracy

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The housing serves multiple functions simultaneously: it houses the light-emitting devices, supports the light guide member, provides structural framework for the hood, and enables both uniform illumination and distance measurement functions within a single component

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

2Reliability

If multiple separate components are used for light emission and distance measurement, then functional performance is improved, but assembly time and defect rates increase

Engineering Contradiction:
Improvefunctional performanceVSAvoidassembly efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent merges multiple functional components into integrated assemblies that can be mounted as single units on the circuit board, reducing the number of assembly steps and potential defect points while maintaining the functional performance of multiple light-emitting devices and distance sensor

Inventive Principle:
Principle #5Merging (Combining)

3Illumination intensity

If light-emitting devices are disposed nearer to the object than the photoelectric conversion device, then uniform light intensity in the image capturing range is achieved, but the apparatus size increases and miniaturization becomes difficult

Engineering Contradiction:
Improvelight intensity uniformityVSAvoidapparatus size
Core Design Contradiction:
Illumination intensityVSVolume of moving object

Solution Approach 1:

The patent nests the light guide member within the hood structure, with the light guide member positioned inside the housing and the hood providing external protection. This nested arrangement allows the light-emitting devices to be positioned optimally for uniform illumination while maintaining a compact overall apparatus size through space-efficient structural integration

Inventive Principle:
Principle #7Nested doll (Nesting)

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 a compact, cost-effective, and efficient image capturing apparatus with reduced assembly time and defect rates, achieving uniform illumination and accurate image capture while minimizing the need for adhesives.

Implementation Method 1

a light guide member for guiding the light of the plurality of light-emitting devices to an image capturing range (image capture zone), and illuminating the image capturing range

Methodology Applied
Scientific EffectLight guiding: Optical Fibre

Implementation Method 2

an optical unit accommodated inside the light guide member and for guiding the reflected light of the object in the illuminated image capturing range to the image sensor

Methodology Applied
Scientific EffectLight reflection: Reflection

Implementation Method 3

an optical filter disposed on an object side of the optical unit and the light guide member and being installed to a case

Methodology Applied
Scientific EffectOptical filtering: Filter (optical)

Implementation Method 4

a hood for cutting out light outside of the image capturing range of the optical unit

Methodology Applied
Scientific EffectLight blocking: Absorption (EM radiation)

Implementation Method 5

an image sensor for receiving the reflected light

Methodology Applied
Scientific EffectPhotoelectric conversion: Photoelectric Effect

Data Source

PatentEP1830565B1Image capturing apparatus
Publication Date: 2016.09.28 FUJITSU LTD
  • EP1830565B1 patent drawingFigure 1
  • EP1830565B1 patent drawingFigure 2~3
  • EP1830565B1 patent drawingFigure 4~5

AI summary

An image capturing apparatus for illuminating and capturing an image of an object using reflected light therefrom, having a miniaturized construction and simplified assembly. A plurality of light-emitting devices (22, 24) is mounted around an image sensor (30), and a light guide member (10) guides the light of the light-emitting devices to an image capture zone for illumination. The apparatus is assembled by attaching a projection on the light guide member (10) to the lower end of a hood (78) for excluding external light from the image capture zone and by attaching the upper end of the hood to a filter (76). Thus, it becomes possible to assemble the apparatus with fewer adhesion points and to improve the ease of assembly of the image capturing apparatus, improving production yield efficiency. The apparatus may be employed in biometric readings for identification purposes.