Adapter and optical connection structure
An adapter includes a tubular body having a tubular shape and surrounding a pair of ferrules over half a circumference or more with a ling along a first direction as an axis. The tubular body includes a guide extending in the first direction and engaging with side surfaces of the ferrule, and a slit formed from one end to the other end in the first direction.
1 . An optical connection structure comprising:
an adapter that holds a pair of ferrules facing each other, the adapter comprising:
a tubular body having a substantially rectangular tubular shape and surrounding the pair of ferrules such that the tubular body surrounds half or more of an outer peripheral length of each of the ferrules having a longitudinal axis along a first direction,
wherein the tubular body includes:
a first inner peripheral surface,
a second inner peripheral surface that is parallel to the first inner peripheral surface and faces the first inner peripheral surface along a second direction that is orthogonal to the first direction,
a third inner peripheral surface that is orthogonal to the first inner peripheral surface and to the second inner peripheral surface,
a fourth inner peripheral surface that is parallel to the third inner peripheral surface that faces the third inner peripheral surface along a third direction orthogonal to the first direction and the second direction,
a first guide that protrudes from the first inner peripheral surface toward the second inner peripheral surface, and
a second guide that protrudes from the second inner peripheral surface toward the first inner peripheral surface,
wherein a top surface of the tubular body and the third inner peripheral surface define an upper wall of the tubular body, and
wherein a slit is formed in the upper wall and extends in the first direction from a first end to a second end opposite the first end of the tubular body; and
the pair of ferrules held in the tubular body of the adapter, wherein;
each of the pair of ferrules has a first engaging portion on a first side surface and a second engaging portion on a second side surface opposing the first side surface,
the first engaging portion of each of the pair of ferrules engages with the first guide,
the second engaging portion of each of the pair of ferrules engages with the second guide, and
the pair of ferrules are biased in a direction in which the ferrules face each other via a pair of springs respectively disposed on a rear end side of each of the ferrules.
2 . The optical connection structure according to claim 1 , wherein the tubular body of the adapter is made of resin.
3 . The optical connection structure according to claim 1 , wherein the first guide and the second guide each protrude inward from the respective first and second inner peripheral surfaces of the tubular body, such that the first guide and the second guide protrude directly toward each other along the second direction orthogonal to the first direction and to the third direction.
4 . The optical connection structure according to claim 1 , wherein when viewed in the first direction, each of the first guide and the second guide has an arc shape.
5 . The optical connection structure according to claim 1 , wherein when viewed in the first direction, the tubular body has a substantially rectangular frame shape, and
the first and second inner peripheral surfaces are a pair of wall bodies forming short sides of the rectangular frame shape formed by the tubular body when viewed in the first direction.
6 . The optical connection structure according to claim 1 ,
the first and second engaging portions are grooves that are respectively formed in the first side surface and the second side surface of each of the pair of ferrules, and
the first and second engaging portions extend in the first direction.
7 . The optical connection structure according to claim 6 ,
wherein a cross-sectional shape of the grooves that intersects with the first direction is a V shape.
8 . The optical connection structure according to claim 1 ,
wherein a force with which the first guide and the second guide press the pair of ferrules is smaller than spring loads with which the pair of springs bias the pair of ferrules.
9 . The optical connection structure according to claim 1 , wherein
each of the pair of ferrules has a rear end surface that is opposite a front end surface facing each other,
the rear end surface of each of the pair of ferrules has a pair of projections that project in the first direction or a direction opposite the first direction,
the pair of projections are provided on both ends of the rear end surface in the second direction orthogonal to the first direction.
10 . The optical connection structure according to claim 9 , wherein
the pair of springs that bias the pair of ferrules in the direction in which the ferrules face each other, are disposed between the pair of projections.
11 . The optical connection structure according to claim 1 , wherein
when viewed in the first direction, in a no-load state, a shortest distance from a tip of the first guide to a tip of the second guide along the second direction is smaller than a shortest distance between the first and second engaging portions on each of the pair of ferrules, and
when viewed in the first direction, in a load state where the pair of ferrules are held inside the tubular body, the tubular body elastically deforms to be expanded in the third direction orthogonal to the first direction and the second direction such that the slit in the upper wall is widened.