WO2025164062A1 - Connection unit - Google Patents

Abstract

This connection unit comprises: a unit housing; and at least 10 trays supported by the unit housing so as to be slidable in a longitudinal direction. Each of the at least 10 trays has a first introduction part for introducing a first optical fiber group into the tray, a second introduction part for introducing a second optical fiber group into the tray, and a connection part holding region for holding a fusion splicing part of the first optical fiber group and the second optical fiber group. The dimension in the vertical direction of the one unit housing is 128 mm, and the at least 10 trays are arranged in the vertical direction.

Description

Connection Unit

The present disclosure relates to a connection unit.
This application claims priority based on Japanese Patent Application No. 2024-015077, filed February 2, 2024, the contents of which are incorporated herein by reference.

Patent Document 1 discloses an optical cabinet for constructing an optical network. Inside the optical cabinet, a connection unit for connecting optical fibers is located.

U.S. Pat. No. 1,086,6378

Such connection units require increased optical fiber packing density.

This disclosure has been made in consideration of these circumstances, and aims to provide a connection unit that increases the optical fiber packing density.

In order to solve the above problem, the connection unit according to aspect 1 of the present disclosure comprises a unit housing and at least 10 trays supported by the unit housing so as to be slidable in the front-to-rear direction, each of the at least 10 trays having a first introduction section for introducing a first optical fiber group into the inside of the tray, a second introduction section for introducing a second optical fiber group into the inside of the tray, and a connection section holding area for holding the fusion spliced sections of the first optical fiber group and the second optical fiber group, the vertical dimension of one unit housing being 128 mm, and the at least 10 trays being arranged side by side in the vertical direction.

Aspect 2 of the present disclosure is a connection unit according to aspect 1, wherein the unit housing has an openable/closable unit door, the at least 10 trays each have a tray operation unit that protrudes forward, and the unit door has insertion holes that extend in the vertical direction, and when the unit door is closed, the tray operation units protrude forward of the unit door through the insertion holes.

Aspect 3 of the present disclosure is a connection unit according to aspect 1 or 2, in which the thickness of each of the at least 10 trays in the vertical direction is 7.7 mm or less.

The above aspects of the present disclosure make it possible to provide a connection unit with increased optical fiber packing density.

1 is a schematic configuration diagram of an optical wiring system according to an embodiment of the present invention. FIG. 2 is a diagram of the optical cabinet of FIG. 1 with the cabinet door and optical cables omitted. FIG. 3 is an enlarged view of FIG. 2. FIG. 4 is a perspective view of a portion IV in FIG. 3 . 5 is a cross-sectional view taken along the line VV in FIG. 4. FIG. 4 is a perspective view of the connection unit of FIG. 3 . 7 is a view showing the connection unit of FIG. 6 with the unit door open and one tray pulled out. FIG. 8 is a perspective view of the tray of FIG. 7 alone. FIG. 8 is an enlarged cross-sectional view of part IX in FIG. 7. FIG. 2 is a perspective view of the patch panel of FIG. 1; 11 is a cross-sectional view taken along the line XI-XI in FIG. 10. 12 is a cross-sectional view taken along the arrows XII-XII in FIG. 10. FIG. 10 is a diagram of a tray according to a modified example.

The optical cabinet, patch panel, connection unit, and optical wiring system including these components of this embodiment will be described below.
1, the optical wiring system 1 includes an optical cabinet 2 and a plurality of patch panels 3. An optical cable C1 is introduced into the optical cabinet 2. The optical cabinet 2 and the plurality of patch panels 3 are connected by a plurality of optical cables C2. The optical cabinet 2 and the patch panels 3 do not need to be located in the same room or building.

<Direction definition>
In the figure, the Z axis represents the up-down direction, the X axis represents the left-right direction, and the Y axis represents the front-to-back direction. The +Z side is the top and the -Z side is the bottom. The +X side is the right and the -X side is the left. The +Y side is the front and the -Y side is the rear. Typically, a user performs operations from the front of the optical cabinet 2 or the front or rear of the patch panel 3. However, the left-to-right direction X and the front-to-back direction Y do not need to coincide between the optical cabinet 2 and the patch panel 3.

<Optical Cabinet 2>
As shown in FIG. 1 , the optical cabinet 2 has a cabinet housing 100. The cabinet housing 100 is divided into an upper section 101 and a lower section 102. The lower section 102 is provided with a plurality of inlets 102a. Some of the inlets 102a are covered by panels 102b. In FIG. 1 , an optical cable C1 is introduced from the front inlet 102a, and an optical cable C2 is introduced from the side inlet 102a. However, to introduce the optical cables C1 and C2 into the cabinet housing 100, only the side inlet 102a or only the front inlet 102a may be used.

Two cabinet doors 103 are provided on the upper portion 101. Figure 2 is a front view of the optical cabinet 2, omitting the cabinet doors 103 and optical cables C1 and C2. As shown in Figure 2, the interior of the cabinet housing 100 is divided into four areas A1 to A4 by a first imaginary line O1 and a second imaginary line O2. The first imaginary line O1 extends in the up-down direction Z, and the second imaginary line O2 extends in the left-right direction X, perpendicular to the first imaginary line O1. The first imaginary line O1 is located at the center of the cabinet housing 100 in the left-right direction X. The first area A1 and the second area A2 are located to the left of the first imaginary line O1. The third area A3 and the fourth area A4 are located to the right of the first imaginary line O1. The first area A1 and the third area A3 are located above the second imaginary line O2. The second area A2 and the fourth area A4 are located below the second imaginary line O2.

Two ducts 104 are provided inside the cabinet housing 100. The two ducts 104 extend in the vertical direction Z and overlap the entire areas A2 and A4 in the vertical direction Z. The two ducts 104 are also arranged side by side in the horizontal direction X near the second imaginary line O2 (near the center of the cabinet housing 100).

The duct 104 is located between the second area A2 and the fourth area A4 in the left-right direction X. While optical cables C1 and C2 are not shown in Figure 2, optical cables C1 and C2 may include optical lines from multiple telecommunications carriers. In this embodiment, optical lines from different telecommunications carriers can be assigned to the four areas A1 to A4. For example, the optical line of the telecommunications carrier corresponding to the first area A1 is introduced into the first area A1 from the inlet 102a through the duct 104 on the left. Similarly, the optical line of the telecommunications carrier corresponding to the third area A3 is introduced into the third area A3 from the inlet 102a through the duct 104 on the right. In this way, using the duct 104 can prevent crosstalk between different telecommunications carriers.

Each of the four areas A1 to A4 is provided with an area cover 107. Figure 3 is an enlarged view of area A1 with the area cover 107 removed. As shown in Figure 3, multiple connection units 4 (four in the figure) are arranged in the first area A1. Although not shown, multiple connection units 4 are also arranged in areas A2 to A4. At least a portion of the optical cable C2 is inserted inside the duct 104. The optical cable C2 includes multiple wiring W. The "wiring W" is, for example, an optical cord including multiple optical fibers. In Figure 3, the paths of some of the wiring W are indicated by dashed double-dashed lines. A curved guide 105 and a holding member 106 are provided inside the cabinet housing 100 and above the duct 104. Some of the wiring W is held by the curved guide 105 and introduced into the connection unit 4. Some of the wiring W is held by the curved guide 105 and the holding member 106 and introduced into the connection unit 4. Some of the wiring W may not be held by the curved guide 105, but may be held by the holding member 106 and introduced into the connection unit 4.

Figure 4 is an enlarged perspective view of portion IV in Figure 3. As shown in Figure 4, the curved guide 105 has an attachment portion 105a, a plate portion 105b, a curved surface 105c, a clamp 105d, and a guide wall 105e. The attachment portion 105a is the portion that is attached to the cabinet housing 100. The plate portion 105b extends forward from the attachment portion 105a and is plate-shaped and parallel to the front-rear direction Y and the up-down direction Z. The plate portion 105b supports the curved surface 105c and the clamp 105d. The curved surface 105c is convex upward and protrudes from the plate portion 105b in the left-right direction X. The guide wall 105e is plate-shaped and parallel to the plate portion 105b. The curved surface 105c is sandwiched between the guide wall 105e and the plate portion 105b.

As shown in FIG. 4, the holding member 106 has an attachment portion 106a, a plate portion 106b, and a holding portion 106c. The attachment portion 106a is the portion that is attached to the cabinet housing 100. The plate portion 106b extends forward from the attachment portion 106a and is a plate-like member that is parallel to the front-to-rear direction Y and the up-to-down direction Z. The plate portion 106b supports the holding portion 106c. The holding portion 106c can hold the wiring W between itself and the plate portion 106b.

Figure 5 is a cross-sectional view taken along the V-V line in Figure 4. In Figure 5, the wiring W supported by the curved guide 105 is indicated by a two-dot chain line. The curved surface 105c supports the wiring W from below. Furthermore, the clamp 105d clamps the wiring W supported by the curved surface 105c. The plate portion 105b and the guide wall 105e can regulate the position of the wiring W in the left-right direction X.

As shown in Figure 3, a portion of the wiring W included in the optical cable C1 is introduced into the connection unit 4 via the curved guide 105. For example, the wiring W is passed through the space between the curved surface 105c and the mounting portion 105a (see Figure 5), placed on the curved surface 105c, and hangs down in front of the curved surface 105c due to its own weight. At this time, the bending radius of the wiring W is determined by the curved surface 105c. In other words, bending of the wiring W at a radius smaller than that of the curved surface 105c is restricted. This makes it possible to prevent localized lateral pressure from acting on the optical fiber. Therefore, it is possible to prevent an increase in transmission loss in the optical fiber.

Furthermore, a portion of the wiring W included in the optical cable C2 is introduced into the connection unit 4 via the holding member 106. At this time, the position of the wiring W in the front-to-rear direction Y is restricted by the holding portion 106c. This prevents the wiring W from being positioned further forward than the predetermined position and coming into contact with the cabinet door 103, for example.

<Connection unit 4>
As shown in FIG. 6 , the connection unit 4 includes a unit housing 10 and multiple trays 20. The multiple trays 20 are arranged side by side in the vertical direction Z and are slidable in the front-to-rear direction Y. The unit housing 10 includes an upper wall 11, two side walls 12, a lower wall 13, a unit door 14, two unit hinges 15, and two knobs 16. The upper wall 11 and the lower wall 13 are plate-shaped extending in the left-to-right direction X and the front-to-rear direction Y and are spaced apart in the vertical direction Z. The two side walls 12 are spaced apart in the left-to-right direction X. Note that the left (−X side) side wall 12 is not shown in FIG. 6 . The two side walls 12 slidably support both ends of the tray 20 in the left-to-right direction X. As will be described in detail later, multiple openings 12b (see FIG. 7 ) are formed in the front wall (front lateral wall 12a) of the side wall 12. The number of openings 12 b corresponds to the number of trays 20 included in the connection unit 4 .

The two unit hinges 15 are positioned between the lower end of the unit door 14 and the front end of the bottom wall 13. The unit door 14 can rotate around the unit hinges 15. Figure 7 shows the unit door 14 rotated around the unit hinges 15 and opened. Also in Figure 7, the lowest tray 20 has been pulled out forward. Two insertion holes 14a are formed in the unit door 14. The two insertion holes 14a extend in the vertical direction Z and are spaced apart in the left-right direction X. In other words, when the unit door 14 is closed, the insertion holes 14a extend in the vertical direction Z.

As shown in FIG. 8, a first optical fiber group F1 and a second optical fiber group F2 are introduced into the tray 20. For example, the first optical fiber group F1 is the optical fiber included in the optical cable C1, and the second optical fiber group F2 is the optical fiber included in the optical cable C2 (see FIG. 1). The tray 20 serves to hold the fusion spliced portion of the optical fibers F1 and F2. In other words, the connection unit 4 serves to hold the spliced portion of the optical cables C1 and C2.

The tray 20 has a first introduction section 21, a second introduction section 22, a tray front wall 23, two rails 24, two restricting pieces 25, two locking pieces 26, a tray bottom wall 27, and multiple retaining ribs 28. The first introduction section 21 is a section for introducing the first optical fiber group F1 into the tray 20. The second introduction section 22 is a section for introducing the second optical fiber group F2 into the tray 20. The first introduction section 21 and the second introduction section 22 are located at both ends of the tray 20 in the left-right direction X. The first introduction section 21 and the second introduction section 22 each have multiple partitions, and the optical fibers F1 and F2 are passed between the partitions.

The tray front wall 23 is located in front of the first introduction section 21 and the second introduction section 22, and extends in the left-right direction X. Two tray operation sections 23a are formed on the tray front wall 23. The tray operation sections 23a are spaced apart in the left-right direction X and protrude forward from the tray front wall 23. The tray operation section 23a is a rectangular plate extending in the left-right direction X and the front-rear direction Y. When pulling the tray 20 forward relative to the unit housing 10, the user can pinch and operate the tray operation section 23a. By using a tray operation section 23a with this shape, the thickness of the tray 20 in the up-down direction Z can be reduced, allowing more trays 20 to be included in multiple connection units 4.

For example, the tray operation unit 23a may be provided with an identification unit for identifying the optical fibers F1, F2. A specific example of the identification unit is the wiring number of the telecommunications carrier to which the optical fibers F1, F2 belong. The identification unit may be engraved on the tray operation unit 23a. Alternatively, a sticker or the like serving as the identification unit may be adhered to the tray operation unit 23a. As shown in FIG. 6, even when the unit door 14 is closed, the tray operation unit 23a protrudes forward through the insertion hole 14a. Therefore, the user can see the tray operation unit 23a and the identification unit even when the unit door 14 is closed.

As shown in Figure 8, two rails 24 extend rearward from the first introduction section 21 and the second introduction section 22. Each rail 24 is passed through the inside of an opening 12b formed in the lateral front wall 12a (see Figure 7). One regulating piece 25 and one locking piece 26 are formed for each rail 24. The regulating piece 25 is located at the rear end of the rail 24, and the locking piece 26 is located at the front end of the rail 24. A regulating protrusion 25a is formed at the rear end of the regulating piece 25. The regulating piece 25 is elastically deformable in the vertical direction Z, with the front end of the regulating piece 25 as the base point. A locking protrusion 26a is formed at the front end of the locking piece 26. The locking piece 26 is elastically deformable in the vertical direction Z, with the rear end of the locking piece 26 as the base point.

Figure 9 is an enlarged cross-sectional view of part IX in Figure 7 taken along a plane perpendicular to the left-right direction X. As shown in Figure 9, the restricting protrusion 25a has a flat surface (contact surface) that extends in the up-down direction Z and faces forward. When the tray 20 is pulled forward, the contact surface of the restricting protrusion 25a contacts the lateral front wall 12a. This prevents the tray 20 from moving forward beyond a predetermined position. In addition, the tray 20 can be removed from the unit housing 10 by elastically deforming the restricting piece 25 downward.

As shown in Figure 9, the locking protrusion 26a has an upwardly convex curved surface. That is, the locking protrusion 26a has an upwardly convex curved surface when viewed from the left-right direction X. When the tray 20 is stored in the unit housing 10 (Figure 6), the locking protrusion 26a is located behind the lateral front wall 12a. When the tray 20 is moved forward from this state, the locking protrusion 26a abuts against the lateral front wall 12a. This prevents the tray 20 from sliding forward due to vibration or the like. When the tray 20 is pulled out forward, a forward force is applied to the tray 20, causing the locking piece 26 to elastically deform downward. This allows the locking protrusion 26a to climb over the lateral front wall 12a forward, allowing the tray 20 to be pulled out.

As shown in Figure 8, the tray bottom wall 27 is plate-shaped and extends in the front-to-back direction Y and the left-to-right direction X. The space above the tray bottom wall 27 is divided into a slack storage area 20a and a splice holding area 20b. A plurality of holding ribs 28 are arranged in the splice holding area 20b. The multiple holding ribs 28 protrude upward from the tray bottom wall 27 and are arranged side by side in the front-to-back direction Y. The fusion spliced portions of the optical fibers F1, F2 are held between the holding ribs 28. The slack storage area 20a is the portion of the space above the tray bottom wall 27 excluding the splice holding area 20b. The slack storage area 20a stores the slack of the optical fibers F1, F2 on the tray 20.

In this embodiment, the height dimension Lz1 (see Figure 6) of the unit housing 10 in the vertical direction Z is equivalent to 128 mm. The height of the space between the upper wall 11 and the lower wall 13 of the unit housing 10 is 103.3 mm. Ten trays 20 are stored in this space. In order to store such a large number of trays 20, the thickness Lz2 (see Figure 8) of the tray 20 in the vertical direction Z is set to 7.7 mm or less.

<Patch Panel 3>
10 and 11 , the patch panel 3 includes a patch panel housing 30, an optical cable C2, a fusion sleeve holder 40, a plurality of adapters 50, a long cover 60, and a plurality of small doors 70. As shown in Fig. 11 , the patch panel 3 is configured to branch an optical fiber F2 included in the optical cable C2 and connect it to an optical fiber F4 via an optical fiber F3. As shown in Fig. 11 and 12 , the patch panel housing 30 includes a bottom wall 31, an inner bottom 32, a bottom front wall 33, a plurality of front wall portions 34, and a plurality of rear wall portions 35.

As shown in FIG. 11, the interior of the patch panel housing 30 is partitioned into a first storage area B1, a second storage area B2, a third storage area B3, and a fourth storage area B4. The storage areas B1 to B4 are arranged side by side in the left-right direction X. The first storage area B1 and the fourth storage area B4 are located on the outside in the left-right direction X, while the second storage area B2 and the third storage area B3 are located on the inside in the left-right direction X. In the left-right direction X, each storage area B1 to B4 is partitioned by a partition wall 36. A front wall portion 34 is located at the front end of each storage area B1 to B4. A rear wall portion 35 is located at the rear end of each storage area B1 to B4.

The front wall portions 34 of storage areas B2 and B3 are located further forward than the front wall portions 34 of storage areas B1 and B4. In other words, the storage areas B1 and B4, which are located on the outer sides in the left-right direction X, are offset rearward relative to the storage areas B2 and B3, which are located on the inner sides.

As shown in FIG. 11, optical cable C2 is introduced into first storage area B1 through an opening provided in the rear wall portion 35 of first storage area B1. Multiple optical fibers F2 included in optical cable C2 are connected to multiple optical fibers F3 in a fusion sleeve holding portion 40. The fusion sleeve holding portion 40 holds the fusion spliced portion of optical fibers F2, F3. The fusion sleeve holding portion 40 is disposed within first storage area B1. In other words, first storage area B1 serves as a so-called breakout kit that branches optical cable C2.

The optical fibers F3 extend rearward from the rear wall 35 of the first storage area B1 toward storage areas B2 to B4. The optical fibers F3 are introduced into storage areas B2 to B4 through openings provided in the rear wall 35 of each of the storage areas B2 to B4. The optical fibers F3 introduced into storage areas B2 to B4 form a ribbon fiber T. As an example, the ribbon fiber T includes four optical fibers F3, and two ribbon fiber T are introduced into each of storage areas B2 to B4. In this case, eight optical fibers F3 are introduced into each of storage areas B2 to B4, and the total number of optical fibers F2 included in the optical cable C2 is 24.

A branching section S is located within each of the storage areas B2 to B4. Multiple adapters 50 are attached to the front wall 34 of each of the storage areas B2 to B4. At the branching section S, multiple optical fibers F3 included in the ribbon fiber T are branched and individually connected to the adapters 50. In this way, a so-called fan-out structure that branches the ribbon fiber T is provided within the storage areas B2 to B4. An optical fiber F4 is connected to each adapter 50 from the front. In this way, the patch panel 3 connects the optical fiber F2 (first optical fiber) of the optical cable C2 to the optical fiber F4 (second optical fiber) via the optical fiber F3 (relay fiber).

As shown in FIG. 10, the four small doors 70 are arranged in positions corresponding to the four storage areas B1 to B4 (see FIG. 11) in the left-right direction X. Because storage areas B1 and B4 are offset rearward relative to storage areas B2 and B3, the small doors 70 corresponding to storage areas B1 and B4 are also offset rearward relative to the small doors 70 corresponding to storage areas B2 and B3. The long cover 60 is located forward of the four small doors 70 and is arranged so as to straddle these small doors 70 in the left-right direction X. The long cover 60 serves to protect the optical fiber F4 routed in the space forward of the small doors 70. The long cover 60 is rotatably supported by multiple hinges 61. The small doors 70 are rotatably supported by multiple hinges 72. A knob 71 is provided on the small doors 70.

When operating the patch panel 3, the user first opens the long cover 60. Next, they open the small door 70 corresponding to the storage area B2-B4 that will be the target of the work. Then, they switch the connection destination of the optical fiber F4 by inserting or removing the connector attached to the tip of the optical fiber F4 into or from the adapter 50.

Figure 12 is a cross-sectional view taken along the XII-XII line in Figure 10. Figure 12 is a cross-sectional view corresponding to the third storage area B3. However, the other storage areas B1, B2, and B4 also have similar structures for the bottom wall 31, inner bottom 32, and bottom front wall 33. Storage areas B1 to B4 have a double-bottom structure. More specifically, the inner bottom 32 is provided above the bottom wall 31 of the patch panel housing 30. The bottoms of storage areas B1 to B4 are defined by the inner bottom 32. The bottom front wall 33 is located between the bottom wall 31 and the inner bottom 32 in the vertical direction Z. The front wall 34 extends upward from the front end of the inner bottom 32.

By adopting this double-bottom structure, space is secured in front of the front wall 34 for the optical fiber F4 to bend downward. This allows for a large bending radius for the optical fiber F4 when it is bent in the left-right direction X in front of each storage area B2 to B4, as shown in Figure 11. This prevents localized bending stress from occurring in the optical fiber F4, while also preventing cross-connection between the optical fibers F connected to the storage areas B2 to B4.

As described above, the connection unit 4 of this embodiment comprises a unit housing 10 and at least ten trays 20 supported by the unit housing 10 so as to be slidable in the front-to-rear direction Y. Each of the trays 20 has a first introduction section 21 for introducing the first optical fiber group F1 into the inside of the tray 20, a second introduction section 22 for introducing the second optical fiber group F2 into the inside of the tray, and a splice holding area 20b for holding the fusion splices of the first optical fiber group F1 and the second optical fiber group F2. The dimension of one unit housing 10 in the vertical direction Z is 128 mm, and at least ten trays 20 are arranged vertically. With this configuration, more optical fiber groups F1 and F2 can be connected using one connection unit 4, thereby increasing the optical fiber packing density.

The unit housing 10 also has an openable and closable unit door 14, and each of the multiple trays 20 has a tray operation unit 23a that protrudes forward. The unit door 14 has an insertion hole 14a that extends in the vertical direction Z. When the unit door 14 is closed, the multiple tray operation units 23a protrude forward of the unit door 14 through the insertion hole 14a. With this configuration, the tray operation units 23a can be seen even when the unit door 14 is closed. Therefore, operability is improved when an identification unit for a communication carrier or the like is provided on the tray operation unit 23a.

Furthermore, the thickness Lz2 in the vertical direction Z of each of the multiple trays 20 is 7.7 mm or less. This configuration allows the unit housing 10 to be equipped with a large number of trays 20.

The technical scope of this disclosure is not limited to the above-described embodiments, and various modifications may be made without departing from the spirit of this disclosure.

For example, in the patch panel 3 of the above embodiment, the first storage area B1 was used as a so-called breakout kit. However, like the second storage area B2, the first storage area B1 may also be used as an area for connecting the optical fiber F3 and the optical fiber F4.

The shape of the tray 20 may also be changed. For example, as shown in FIG. 13, the tray 20 may have multiple lid portions 81, 82, and 84. The lid portion 81 is rotatable around a hinge 81a and has a locking portion 81b. The locking portion 81b of the lid portion 81 is locked to a main body side locking portion 81c provided on the main body of the tray 20, preventing the lid portion 81 from floating up. In this case, the lid portion 81 covers the connection portion holding area 20b from above, thereby protecting the connection portion holding area 20b.

Similarly, the lids 82, 84 are rotatable around hinges 82a, 84a and have locking portions 82b, 84b. The locking portions 82b, 84b are locked to main body locking portions 82c, 84c provided on the main body of the tray 20, preventing the lids 82, 84 from lifting up. At this time, the lids 82, 84 cover part of the slack storage area 20a from above, preventing the optical fiber from lifting up from the slack storage area 20a.

Furthermore, within the scope of the spirit of this disclosure, the components in the above-described embodiments may be replaced with well-known components, and the above-described embodiments and variations may be combined as appropriate.

4...Connection unit 10...Unit housing 14...Unit door 14a...Insertion hole 20...Tray 20b...Connection holding area 21...First entry section 22...Second entry section 23a...Tray operation section A1-A4...Area Y...Front-to-back direction Z...Up-to-down direction

Claims (3)

A unit housing;
At least ten trays are supported by the unit housing so as to be slidable in the front-rear direction,
each of the at least ten trays has a first introduction section for introducing a first optical fiber group into the inside of the tray, a second introduction section for introducing a second optical fiber group into the inside of the tray, and a splice holding area for holding a fusion splice of the first optical fiber group and the second optical fiber group;
The vertical dimension of one unit housing is 128 mm,
The at least ten trays are arranged in a line in the vertical direction. The unit housing has an openable and closable unit door,
Each of the at least 10 trays has a tray operating portion protruding forward,
The unit door has an insertion hole extending in the vertical direction,
The connection unit according to claim 1 , wherein the tray operation portions protrude forward of the unit door through the insertion holes when the unit door is closed. The connection unit described in claim 1 or 2, wherein the thickness of each of the at least 10 trays in the vertical direction is 7.7 mm or less.