Optical transducer for endoscope, endoscope, and manufacturing method for optical transducer for endoscope

1. An optical transducer for endoscope comprising:

at least one optical element configured to generate an optical signal;

at least one optical fiber configured to transmit the optical signal; and

a fiber holding member including a first holding member made of a nontransparent material, the first holding member including a first principal surface and a second principal surface on an opposite side of the first principal surface, and a second holding member made of a transparent material, the second holding member including a third principal surface and a fourth principal surface on an opposite side of the third principal surface, the third principal surface being disposed to face the second principal surface, at least one through-hole being formed in the first holding member, the optical fiber being inserted into the first through-hole, the fiber holding member including, on the fourth principal surface, a bonded electrode on which the optical element is mounted, wherein

at least one trench connected to the first through-hole and including openings respectively on two parallel side surfaces is formed on the second principal surface of the first holding member,

only a part of a distal end portion of the optical fiber inserted into the first through-hole is observable from the openings of the trench, and

the optical fiber is fixed to the fiber holding member by transparent resin disposed in the first through-hole and the trench.

2. The optical transducer for endoscope according to claim 1 , wherein the second principal surface and the third principal surface are bonded.

3. The optical transducer for endoscope according to claim 1 , wherein the optical transducer for endoscope comprises:

a plurality of optical elements;

a plurality of optical fibers; and

the first holding member in which a plurality of first through-holes are formed.

4. The optical transducer for endoscope according to claim 1 , further comprising a third holding member including a fifth principal surface bonded to the second principal surface and a sixth principal surface bonded to the third principal surface, the third holding member being made of a nontransparent material, at least one second through-hole having a same center as a center of the first through-hole being formed in the third holding member.

5. The optical transducer for endoscope according to claim 4 , wherein

the optical fiber includes an element wire for transmitting the optical signal and a coating layer covering the element wire,

the element wire covered by the coating layer is inserted into the first through-hole of the first holding member, and

the element wire, from which the coating layer is detached, is inserted into the second through-hole of the third holding member.

6. The optical transducer for endoscope according to claim 4 , wherein the optical transducer for endoscope comprises:

a plurality of optical elements;

a plurality of optical fibers;

the first holding member in which a plurality of first through-holes are formed; and

the third holding member in which a plurality of second through-holes are formed.

7. The optical transducer for endoscope according to claim 1 , wherein the trench is not formed in a region facing the bonded electrode in the second principal surface.

8. A manufacturing method for an optical transducer for endoscope, the optical transducer for endoscope including:

at least one optical element configured to generate an optical signal;

at least one optical fiber configured to transmit the optical signal; and

a fiber holding member including a first holding member made of a nontransparent material, the first holding member including a first principal surface and a second principal surface on an opposite side of the first principal surface, and a second holding member made of a transparent material, the second holding member including a third principal surface and a fourth principal surface on an opposite side of the third principal surface, the third principal surface being disposed to face the second principal surface, at least one through-hole being formed in the first holding member, the optical fiber being inserted into the first through-hole, the fiber holding member including, on the fourth principal surface, a bonded electrode on which the optical element is mounted,

at least one trench connected to the first through-hole and including openings respectively on two parallel side surfaces being formed on the second principal surface of the first holding member,

only a part of a distal end portion of the optical fiber inserted into the first through-hole being observable from the openings of the trench,

the optical fiber being fixed to the fiber holding member by transparent resin disposed in the first through-hole and the trench,

the manufacturing method comprising:

manufacturing the holding member;

injecting the transparent resin uncured into at least one of the first through-hole or the trench;

inserting the optical fiber into the first through-hole and bringing a distal end face of the optical fiber into contact with the third principal surface; and

curing the transparent resin in a state in which the distal end face is in contact with the third principal surface.

9. The manufacturing method for the optical transducer for endoscope according to claim 8 , wherein, when the optical fiber is inserted, illumination light that does not cure the transparent resin is made incident from one opening of the trench and the contact of the distal end face with the third principal surface is confirmed from another opening.

10. The manufacturing method for the optical transducer for endoscope according to claim 8 , wherein, when the optical fiber is fixed, ultraviolet light for curing the transparent resin is made incident from at least one of the openings of the trench.

11. An endoscope comprising an optical transducer for endoscope,

the optical transducer for endoscope including:

at least one optical element configured to generate an optical signal;

at least one optical fiber configured to transmit the optical signal; and

a fiber holding member including a first holding member made of a nontransparent material, the first holding member including a first principal surface and a second principal surface on an opposite side of the first principal surface, and a second holding member made of a transparent material, the second holding member including a third principal surface and a fourth principal surface on an opposite side of the third principal surface, the third principal surface being disposed to face the second principal surface, at least one through-hole being formed in the first holding member, the optical fiber being inserted into the first through-hole, the fiber holding member including, on the fourth principal surface, a bonded electrode on which the optical element is mounted, wherein

at least one trench connected to the first through-hole and including openings respectively on two parallel side surfaces is formed on the second principal surface of the first holding member,

only a part of a distal end portion of the optical fiber inserted into the first through-hole is observable from the openings of the trench, and

the optical fiber is fixed to the fiber holding member by transparent resin disposed in the first through-hole and the trench.