Abstract: A bobbin for winding optical fiber includes: a body around which an optical fiber is wound; a flange that extends in a radial direction from the body; and a seal that is bonded to an axially outer side surface of the flange. The flange has a void penetrating the flange. A part of the seal covers at least a part of the void. At least a part of a portion of the seal is non-adhesive. The portion covers the void.

Abstract: An optical fiber winding bobbin includes: a main winding body portion having an outer circumferential surface around which an optical fiber is wound; and a main winding flange that is disposed on one end portion of the main winding body portion in an axial direction and that protrudes radially outward. The main winding flange includes: an inner circumferential edge portion connected to the main winding body portion; a central portion; and an outer circumferential portion having a thin portion and positioned outward from the central portion in a radial direction. An axial thickness of the thin portion is smaller than an axial thickness of the inner circumferential edge.

Abstract: An optical fiber winding bobbin includes: a main winding body portion having an outer circumferential surface around which an optical fiber is wound; and a main winding flange that is disposed on one end portion of the main winding body portion in an axial direction and that protrudes radially outward. The main winding flange includes: an inner circumferential edge portion connected to the main winding body portion; a central portion; and an outer circumferential portion having a thin portion and positioned outward from the central portion in a radial direction. An axial thickness of the thin portion is smaller than an axial thickness of the inner circumferential edge.

Abstract: An optical fiber terminal fixing tool includes: a disc-shaped substrate having a plate surface; a holding surface which is provided on the plate surface and interposes the terminal portion of the optical fiber between the holding surface and the first flange portion; and a protrusion which continues in a circumferential direction with a larger diameter than an outer diameter of the first flange portion in an outer circumferential portion on the plate surface while protruding toward the bobbin in a state where the fixing tool is mounted on the rotating shaft of the optical fiber winding machine.

Abstract: An optical fiber terminal fixing tool includes: a disc-shaped substrate having a plate surface; a holding surface which is provided on the plate surface and interposes the terminal portion of the optical fiber between the holding surface and the first flange portion; and a protrusion which continues in a circumferential direction with a larger diameter than an outer diameter of the first flange portion in an outer circumferential portion on the plate surface while protruding toward the bobbin in a state where the fixing tool is mounted on the rotating shaft of the optical fiber winding machine.