Optical Fiber Ribbon With Recessed Fibers for Core Alignment

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Solution Overview

Problem

Existing optical fiber ribbons with circular cross-sections face challenges in aligning the disposition of cores due to difficulty in rotating individual fibers, making it hard to achieve precise alignment during ribbonization.

Innovation Solution

The optical fiber ribbon features a recessed surface portion in the cross-section of each fiber, allowing for easier alignment of rotation angles and core disposition by forming recessed surface portions in the secondary resin layer, which does not affect light transmission characteristics.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If optical fibers with circular cross-section are used, then the structure is simple and easy to manufacture, but aligning the disposition of cores becomes difficult

Engineering Contradiction:
Improveease of manufactureVSAvoidalignment precision
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent applies asymmetry by forming a recessed surface portion in the coating layer of each optical fiber, transforming the previously symmetric circular cross-section into an asymmetric shape. This recessed portion serves as a alignment mark that enables precise orientation of optical fibers during ribbon formation, solving the alignment difficulty while maintaining manufacturing simplicity

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The recessed surface portion is formed in advance during the coating process, before the optical fibers are assembled into a ribbon. This preliminary formation of alignment marks allows for easy and precise alignment during subsequent ribbonization without requiring complex alignment procedures

Inventive Principle:
Principle #10Preliminary action

2Manufacturing precision

If recessed surface portions are formed in the coating layer, then alignment of core disposition becomes easy, but light transmission characteristics may be affected

Engineering Contradiction:
Improvealignment precisionVSAvoidlight transmission
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The recessed surface portion is formed only in the coating layer (secondary resin layer) and not in the glass fiber core or cladding. This local modification ensures that the alignment function is provided without affecting the light transmission properties of the optical fiber, as the recess is confined to the outermost layer

Inventive Principle:
Principle #3Local quality

3Manufacturing precision

If optical fibers are aligned by rotating individual fibers, then core disposition can be adjusted, but the process becomes complex and difficult

Engineering Contradiction:
Improvealignment precisionVSAvoidprocess complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The recessed surface portions act as self-aligning features that automatically guide the optical fibers into the correct orientation during ribbon formation. The alignment marks on each fiber self-align with corresponding marks on adjacent fibers, eliminating the need for complex rotation and adjustment operations

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP4703782A1Optical fiber ribbon
Publication Date: 2026.03.04 SUMITOMO ELECTRIC INDUSTRIES LTD
  • EP4703782A1 patent drawingFigure 1
  • EP4703782A1 patent drawingFigure 2
  • EP4703782A1 patent drawingFigure 3

AI summary

An optical fiber ribbon according to one embodiment includes a plurality of optical fibers aligned along a first direction and extending along a second direction intersecting the first direction; and a ribbon material that covers the plurality of optical fibers. In a cross-section orthogonal to the second direction, each of the optical fibers includes a recessed surface portion that is recessed with respect to an imaginary extension plane extending along an outer peripheral surface of the optical fiber.