Optical fiber unit, optical fiber cable, connector-equipped cable, and method for connecting optical fiber unit
An optical fiber unit includes a plurality of optical fibers, a fibrous filler disposed along the plurality of optical fibers, and a resin film covering the plurality of optical fibers and the fibrous filler from outside. In the optical fiber unit, the resin film has a film thickness smaller than a diameter of the fibrous filler.
1 . An optical fiber unit comprising:
a plurality of optical fibers;
a fibrous filler disposed along the plurality of optical fibers; and
a resin film covering the plurality of optical fibers and the fibrous filler,
wherein the resin film has a film thickness smaller than a diameter of the fibrous filler,
only a part of the fibrous filler is embedded in the resin film,
a remaining part of the fibrous filler is exposed inside from an inner periphery of the resin film,
more than 50 percent of the fibrous filler is exposed inside from the inner periphery of the resin film in a cross-sectional view of the optical fiber unit, and
an exposed surface of the fibrous filler directly faces the plurality of optical fibers.
2 . The optical fiber unit according to claim 1 ,
wherein the fibrous filler is provided on an inner surface of the resin film along a longitudinal direction of the optical fibers.
3 . The optical fiber unit according to claim 1 ,
wherein the plurality of optical fibers is formed by stranding a plurality of single-core optical fibers or a plurality of bundles of a plurality of optical fibers.
4 . The optical fiber unit according to claim 1 ,
wherein the plurality of optical fibers is an intermittent-connection-type optical fiber ribbon, and in the intermittent-connection-type optical fiber ribbon, some or all of the plurality of optical fibers each includes, intermittently in the longitudinal direction of the plurality of optical fibers, a connection portion at which adjacent optical fibers are connected and a non-connection portion at which adjacent optical fibers are not connected in a state in which the plurality of optical fibers is arranged in parallel in a direction orthogonal to the longitudinal direction.
5 . The optical fiber unit according to claim 4 ,
wherein the plurality of optical fibers is formed by stranding a plurality of the intermittent-connection-type optical fiber ribbons.
6 . The optical fiber unit according to claim 1 ,
wherein the resin film includes an inorganic filler.
7 . The optical fiber unit according to claim 1 ,
wherein the fibrous filler includes a water-absorbent fiber.
8 . The optical fiber unit according to claim 1 ,
wherein the fibrous filler is a PET monofilament.
9 . An optical fiber cable comprising:
a plurality of the optical fiber units according to claim 1 ; and
a sheath covering the plurality of optical fiber units.
10 . The optical fiber cable according to claim 9 , further comprising:
a slot rod having a groove that accommodates at least one of the plurality of optical fiber units inside the sheath.
11 . A connector-equipped cable comprising:
the optical fiber unit according to claim 1 ; and
at least one multi-core connector provided at one end of the optical fiber unit.