Granted Patent B2

US 12,449,587 · App. 18/087,788 · Granted Oct 21, 2025

Inventors: Koki Mitsuno (Nagoya, JP); Satoshi Matsuba (Nagoya, JP); Kenji Hiramoto (Nagoya, JP)

Assignee: Toray Industries, Inc.

G02B6/02033C08L33/08G02B6/03622G02B6/03633A61B1/0017A61B1/07

Abstract

Claims (41)

1. A plastic optical fiber having a multilayer structure that comprises

a core (X),

a first cladding (Y), and

a second cladding (Z),

wherein the core is made of an organic polymer material having

a water-absorbing ratio of not less than 0.001% and not more than 0.29% and

a total light transmittance of not less than 80% and

containing not less than 0.01% by weight and not more than 10% by weight of a plasticizer;

a relationship between a refractive index of the core (X) and a refractive index of the first cladding (Y) is defined by inequality: X−Y>0.01, and

a relationship between the refractive index of the first cladding (Y) and a refractive index of the second cladding (Z) is defined by inequality: Y−Z>0.05,

wherein the plastic optical fiber satisfies inequalities (1) and (2):

2

≤

x

≤

18

,

(

1

)

wherein x is represented by formula: (thickness of the first cladding)×100/(diameter of the fiber) (%); and

5

≤

y

,

(

2

)

wherein y is represented by formula: (thickness of the second cladding)×100/(diameter of the fiber) (%).

2. The plastic optical fiber according to claim 1 , wherein the core (X) is made of a polymer mainly composed of any of styrene, cycloolefin, and methyl pentene.

3. The plastic optical fiber according to claim 1 , wherein the first cladding (Y) is made of a polymer of methyl methacrylate and/or of a copolymer mainly composed of methyl methacrylate and containing not less than 0.1% by weight and not more than 12% by weight of at least one copolymerization component, selected from the group consisting of methyl acrylate, ethyl acrylate, and butyl acrylate.

4. The plastic optical fiber according to claim 1 , wherein the second cladding (Z) has a water-absorbing ratio of not less than 0.001% and not more than 0.29% and an elastic modulus of not less than 100 MPa and not more than 2,000 MPa.

5. The plastic optical fiber according to claim 1 , wherein the second cladding (Z) contains not less than 0.03% by weight and not more than 5.0% by weight of carbon black.

6. The plastic optical fiber according to claim 1 , wherein a value R (dB/km) of optical transmission loss measured at a wavelength of 660 nm and a value I (dB/km) of optical transmission loss measured at a wavelength of 800 nm satisfy inequality: R<I.

7. The plastic optical fiber according to claim 1 , wherein a value R (dB/km) of optical transmission loss measured at a wavelength of 660 nm and a value I (dB/km) of optical transmission loss measured at a wavelength of 800 nm satisfy inequality: 0.2<R/I<1.

8. The plastic optical fiber according to claim 1 , wherein the core (X) has a melt mass flow rate of not less than 1 g/10 min and not more than 200 g/10 min (at a temperature of 230° C. under a load of 3.8 kg).

9. The plastic optical fiber according to claim 1 , wherein a diameter of the fiber is not less than 100 μm and not more than 500 μm.

10. A medical lighting device comprising the plastic optical fiber according to claim 1 .

11. A medical sensor device comprising the plastic optical fiber according to claim 1 .

12. A medical phototherapy device comprising the plastic optical fiber according to claim 1 .

13. A plastic optical fiber cord comprising at least one coating layer in an outer layer over the plastic optical fiber according to claim 1 .

Assignments (1)

Priority Claims (2)

Continuity (1)

References Cited (37)