# US 12,222,574 B2 · Optical fiber unit and optical fiber unit manufacturing method

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- Number: US 12,222,574 B2
- Document ID: US12222574B2
- Status: Granted
- Kind: B2
- Application number: 18/012,371
- Filed: 2021-06-22
- Published: 2023-08-24
- Granted: 2025-02-11
- Earliest claimed: 2020-07-01
- Assignees: Fujikura Ltd.
- Applicants: Fujikura Ltd.
- Inventors: Noriaki Yamashita; Akira Namazue; Ken Osato
- Web page: https://patentgrep.com/patent/US12222574B2

## CPC

- G02B 6/4403: {with ribbon structure (G02B6/4429, G02B6/4439, G02B6/4479 take precedence)}
- G02B 6/448: {Ribbon cables}
- G02B 6/4404: {Multi-podded}
- G02B 6/4482: {Code or colour marking}
- G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS

## Abstract

An optical fiber unit according to the present disclosure includes a plurality of intermittently-connected optical fiber ribbons. At least one of the optical fiber ribbons includes a plurality of optical fibers including a first optical fiber, and a second optical fiber that is longer than the first optical fiber. Conditions (AA) and c<0.05 are satisfied, where b is an interval, in a length direction, between connection parts that connect the first optical fiber and the second optical fiber, c (%) is a fiber length difference of the second optical fiber with respect to the first optical fiber, and Y is an interval between the optical fibers in a ribbon width direction. (AA): C > 100 × { ( 2 ⁢ Y b ) 2 + 1 - 1 }

## Claims

### Claim 1

An optical fiber unit comprising:
intermittently-connected optical fiber ribbons, wherein:
at least one of the intermittently-connected optical fiber ribbons comprises optical fibers including:
a first optical fiber, and
a second optical fiber that is longer than the first optical fiber;
the second optical fiber deforms in a thickness direction of the intermittently-connected optical fiber ribbons with respect to the first optical fiber, and
the following conditions are satisfied:
C
>
100
×
{
(
2
⁢
Y
b
)
2
+
1
-
1
}
and
c<0.05, where
b is an interval, in a length direction, between connection parts that connect the first optical fiber and the second optical fiber,
c (%) is a fiber length difference of the second optical fiber with respect to the first optical fiber, and
Y is an interval between the optical fibers in a ribbon width direction.

### Claim 2 (depends on 1)

The optical fiber unit according to claim 1, further comprising a bundling member that bundles the intermittently-connected optical fiber ribbons.

### Claim 3 (depends on 1)

The optical fiber unit according to claim 1, wherein the second optical fiber is disposed asymmetrically with respect to the ribbon width direction of the intermittently-connected optical fiber ribbons.

### Claim 4 (depends on 3)

The optical fiber unit according to claim 3, wherein:
a first optical fiber ribbon and a second optical fiber ribbon are disposed with respective ribbon surfaces facing one another; and
when viewing the first optical fiber ribbon and the second optical fiber ribbon from the length direction, a position, in the ribbon width direction, of said second optical fiber in the first optical fiber ribbon is different from a position, in the ribbon width direction, of said second optical fiber in the second optical fiber ribbon.

### Claim 5

An optical fiber unit manufacturing method comprising:
preparing an intermittently-connected optical fiber ribbon comprising optical fibers, including: a first optical fiber and a second optical fiber that is longer than the first optical fiber, wherein
the second optical fiber deforms in a thickness direction of the intermittently-connected optical fiber ribbons with respect to the first optical fiber, and
the following conditions are satisfied:
C
>
100
×
{
(
2
⁢
Y
b
)
2
+
1
-
1
}
and
c<0.05, where
b is an interval, in a length direction, between connection parts that connect the first optical fiber and the second optical fiber,
c (%) is a fiber length difference of the second optical fiber with respect to the first optical fiber, and
Y is an interval between the optical fibers in a ribbon width direction; and
assembling intermittently-connected optical fiber ribbons including said intermittently-connected optical fiber ribbon including said second optical fiber.