Optical fiber insertion unit and method for assembling the optical fiber insertion unit

Abstract

To provide an optical fiber insertion unit that suppresses reduction of performance due to thermal expansion.SOLUTION: An optical fiber insertion unit comprises a ferrule, a lens, and a lens sleeve having a lens housing hole for housing the lens in a tip end side and having a ferrule insertion hole for inserting the ferrule in a back end side. The ferrule includes an insertion portion inserted into the lens sleeve, and a grasping portion located in a back end side of the insertion portion and having a flange portion larger than the insertion portion in a radial direction. A length between a back end portion of the lens and the back end portion of the lens sleeve is shorter than a length between a tip end of the ferrule and a surface of the flange portion on the tip end side.SELECTED DRAWING: Figure 1

Claims

1. Ferrule and, Lens and, A lens sleeve having a lens housing hole at the front end for housing the lens and a ferrule insertion hole at the rear end for inserting the ferrule, An optical fiber insertion unit comprising, The aforementioned ferrule is, An insertion portion that is inserted into the aforementioned lens sleeve, It has a gripping portion located on the rear end side of the insertion portion, which includes a flange portion that is radially larger than the insertion portion, The flange portion is provided on the outer side of the tip of the gripping portion. The distance between the tip of the ferrule and the tip-side surface of the flange portion is longer than the distance between the rear end of the lens and the rear end of the lens sleeve, and even when the tip of the insertion portion is in contact with the rear end of the lens, a gap is created between the rear end of the lens sleeve and the tip-side portion of the gripping portion. The thermal expansion coefficient of the lens sleeve is greater than that of the insertion portion. The outer diameter around the ferrule insertion hole of the lens sleeve is smaller than the outer diameter around the lens housing hole of the lens sleeve. The outer diameter of the insertion portion of the ferrule is larger than the inner diameter of the ferrule insertion hole of the lens sleeve, and when the insertion portion is inserted into the ferrule insertion hole, the outer diameter of the lens sleeve around the ferrule insertion hole expands. The tip of the lens sleeve is formed with a light-passing hole, and the inner diameter of the light-passing hole is smaller than the inner diameter of the lens housing hole. A fiber optic insertion unit characterized by the following features.

2. Ferrule and, Lens and, A lens sleeve having a lens housing hole at the front end for housing the lens and a ferrule insertion hole at the rear end for inserting the ferrule insertion portion, An optical fiber insertion unit comprising, The outer diameter around the ferrule insertion hole of the lens sleeve is smaller than the outer diameter around the lens housing hole of the lens sleeve. The outer diameter of the insertion portion of the ferrule is larger than the inner diameter of the ferrule insertion hole of the lens sleeve, and when the insertion portion is inserted into the ferrule insertion hole, the outer diameter of the lens sleeve around the ferrule insertion hole expands. The thermal expansion coefficient of the lens sleeve is greater than that of the insertion portion. The tip of the lens sleeve has a light-passing hole formed therein, and the inner diameter of the light-passing hole is smaller than the inner diameter of the lens housing hole. A fiber optic insertion unit characterized by the following features.

3. A refractive index matching agent is provided between the lens and the ferrule. The optical fiber insertion unit according to claim 1 or 2, characterized in that it is as described above.

4. A method for assembling an optical fiber insertion unit according to any one of claims 1 to 3, The process involves inserting the tip of the optical fiber into the ferrule, The steps include inserting the lens into the lens housing hole of the lens sleeve, The steps include inserting the insertion portion of the ferrule into the ferrule insertion hole and bringing the tip of the ferrule into contact with the lens, including, How to assemble an optical fiber insertion unit.

5. The step of inserting the ferrule into the insertion hole of the lens sleeve and bringing the tip of the ferrule into contact with the lens is characterized by being performed by press-fitting using a servo press. A method for assembling the optical fiber insertion unit described in claim 4.

6. An optical fiber insertion unit according to any one of claims 1 to 3, A shell having a unit insertion hole for inserting the optical fiber insertion unit, and a split sleeve for fixing the lens sleeve of the optical fiber insertion unit within the unit insertion hole, A retaining plate having a through hole that communicates with the optical fiber insertion hole of the ferrule of the optical fiber insertion unit, An optical connector characterized by including [this].

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