U.S. patent application number 14/250007 was filed with the patent office on 2015-10-15 for optical transceiver installing mt ferrule to mate with mpo connector.
This patent application is currently assigned to Sumitomo Electric Industries, Ltd.. The applicant listed for this patent is Sumitomo Electric Industries, Ltd.. Invention is credited to Kuniyuki ISHII, Hideaki KAMISUGI, Hiromi KURASHIMA, Takashi MATSUI, Kazushige OKI, Jignesh SHAH, Lin ZHANG.
Application Number | 20150293315 14/250007 |
Document ID | / |
Family ID | 54149581 |
Filed Date | 2015-10-15 |
United States Patent
Application |
20150293315 |
Kind Code |
A1 |
OKI; Kazushige ; et
al. |
October 15, 2015 |
OPTICAL TRANSCEIVER INSTALLING MT FERRULE TO MATE WITH MPO
CONNECTOR
Abstract
A pluggable optical transceiver with the CFP type and the MT
ferrule is disclosed. The optical transceiver provides in a rear of
the optical receptacle a mechanism to push frontward the MT ferrule
set in the optical receptacle and to shield the inside of the
optical transceiver. Inner fibers connecting the MT ferrule with
another MT ferrule assembled with optical devices pass the
mechanism, which may be a metal plate with the elastic function
and/or a coil spring combined with a holder to hold the MT
ferrule.
Inventors: |
OKI; Kazushige;
(Yokohama-shi, JP) ; MATSUI; Takashi;
(Yokohama-shi, JP) ; ISHII; Kuniyuki;
(Yokohama-shi, JP) ; KAMISUGI; Hideaki;
(Yokohama-shi, JP) ; KURASHIMA; Hiromi;
(Yokohama-shi, JP) ; SHAH; Jignesh; (San Jose,
CA) ; ZHANG; Lin; (San Jose, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Sumitomo Electric Industries, Ltd. |
Osaka-shi |
|
JP |
|
|
Assignee: |
Sumitomo Electric Industries,
Ltd.
Osaka-shi
JP
|
Family ID: |
54149581 |
Appl. No.: |
14/250007 |
Filed: |
April 10, 2014 |
Current U.S.
Class: |
385/92 |
Current CPC
Class: |
G02B 6/403 20130101;
G02B 6/4246 20130101; G02B 6/4201 20130101; G02B 6/3885 20130101;
G02B 6/4292 20130101; G02B 6/4261 20130101 |
International
Class: |
G02B 6/40 20060101
G02B006/40 |
Claims
1. An optical transceiver, comprising: an optical assembly
including an optical device; an optical receptacle coupled with an
external fiber secured in a multiple-fiber push-on (MPO) connector
by receiving the MPO connector therein; an inner fiber coupled with
the optical assembly by a mechanical transfer (MT) ferrule and with
the optical receptacle by another MT ferrule; a mechanism to push
the another MT ferrule toward the optical receptacle and to shield
an inside of the optical transceiver; and a housing configured to
install the optical assembly, the optical receptacle, the inner
fiber, and the mechanism therein, the housing being made of
electrically conductive material.
2. The optical transceiver of claim 1, wherein the mechanism is an
electrically conductive plate and the housing provides a pocket to
receive a portion of the plate, the plate pushing the another MT
ferrule toward the optical receptacle.
3. The optical transceiver of claim 2, wherein the plate provides a
plane portion and two legs forming a cut between the legs, and the
housing provides two pockets and a terrace behind the optical
receptacle, and wherein the legs are inserted into respective
pockets such that the cut of the plate strides across the
terrace.
4. The optical transceiver of claim 3, wherein the inner fiber
passes through a gap formed between the terrace and the plate.
5. The optical transceiver of claim 3, wherein each of legs of the
plate is bent several times to form a U-shaped cross section to
induce a repulsive force against another MT ferrule.
6. The optical transceiver of claim 5, wherein the bent portion of
the plate abuts against the rear wall of the pocket, and the plane
portion pushes rear surface of another MT ferrule.
7. The optical transceiver of claim 3, wherein the plate further
provides a circular opening arrange in parallel with the cut, the
opening passing a guide pin extending from another MT ferrule.
8. The optical transceiver of claim 1, wherein the mechanism
includes a holder and a spring, the housing providing a hollow to
set the mechanism therein, wherein the holder holds the another MT
ferrule, the spring being coupled with the holder and pushing the
another MT ferrule against the optical receptacle.
9. The optical transceiver of claim 8, wherein the spring is a coil
spring, the inner fiber extracted from another MT ferrule passing
inside the coil spring and a cut provided in the wall forming the
hollow.
10. The optical transceiver of claim 1, further including a number
of optical assemblies, wherein each of optical assemblies provides
a plurality of optical devices, the MT ferrule, and a lens assembly
configured to couple the optical devices with the MT ferrule
collectively.
11. The optical transceiver of claim 8, wherein another MT ferrule
set in the optical receptacle secures a plurality of inner fibers
whose total count is equal to the number of optical devices.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present application relates to an optical transceiver,
in particular, the present application relates to an optical
transceiver that provides an MT ferrule to be mated with an
external MPO (Multiple-fiber Push-ON) connector.
[0003] 2. Background Arts
[0004] MPO connectors have been well known in the field of optical
communication. A Japanese Patent Application laid open No.
H10-123366A has disclosed an inner configuration of an MPO
connector. The MPO connector connects fibers in one side with
fibers in other sides; that is, the MPO connector optically couples
a plurality of fibers collectively.
[0005] On the other hand, one type of multi-source agreements (MSA)
has defined details of a pluggable optical transceiver called as
Centum (100) gigabit From-factor Pluggable (hereafter denoted as
CFP). The CFP transceiver in an original specification thereof
provides an optical receptacle types of, what is called, the LC
connector, the SC connector, and so on.
[0006] Recently, as the transmission speed of the optical
communication system increases, where the speed reaches and
sometimes exceeds 25 Gbps, the electro-magnetic interference (EMI)
radiation becomes further important subject. As the transmission
speed increase, namely, the frequency of the signals increases,
which means the wavelength of the signals become shorter, the EMI
noises with higher frequencies easily leak from gaps and/or spaces
with smaller dimensions left in the housing of the optical
transceiver. Moreover, an optical transceiver has been applied from
the field of the trunk line and the subscriber lines to the field
of the data center where data in many channels are sent in parallel
and collectively. Accordingly, recent optical transceivers are
requested to install an optical connector that secures many
transmission fibers, typically, an MT connector. The present
application is to provide an optical transceiver that installs the
MT connector and lowers the EMI noises.
SUMMARY OF THE INVENTION
[0007] An aspect of the present application relates to an optical
transceiver that comprises an optical assembly, and optical
receptacle, an inner fiber, a housing, and a mechanism not only to
secure an optical coupling between the optical receptacle with an
external optical connector but to shield an inside of the optical
transceiver reliably. The optical assembly includes an optical
device. The optical receptacle couples with an external fiber
through an MPO connector by receiving the MPO connector. The inner
fiber couples with the optical assembly by an MT ferrule also with
the optical receptacle by another MT ferrule. That is, the inner
fiber provides MT ferrules in both ends thereof to couple optically
with the optical assembly and the optical receptacle. The housing
installs the optical assembly, the optical receptacle, the inner
fiber, and the mechanism. A feature of the present application is
that the mechanism pushes another MT ferrule toward the optical
receptacle without degrading the EMI tolerance.
[0008] The mechanism may be a plate, typically made of metal, set
behind the optical receptacle and has a U-shape cross section.
Inserting the plate into a pocket provided in the housing, the
plate pushes another MT ferrule against the optical receptacle so
that the other end of the plate contact to the housing.
[0009] Another arrangement of the mechanism may be a combination of
a holder and a spring, and a hollow provided in the housing to set
the combination therein. The holder, which is typically made of
metal, holds a rear portion of another MT ferrule, while, the
spring is set between the holder and the rear wall of the hollow to
push another MT ferrule against the optical receptacle via the
holder. The spring may be a coil spring. The inner fiber extending
from the rear of another MT ferrule pierces the holder, passes
inside of the coil spring and the cut formed in a wall constituting
the hollow.
[0010] Thus, the mechanism has the enhancement of the reliability
of the optical coupling with the external connector, even the
external connector is an MPO connector with an MT ferrule, to be
consistent with the EMI tolerance.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The foregoing and other purposes, aspects and advantages
will be better understood from the following detailed description
of a preferred embodiment of the invention with reference to the
drawings, in which:
[0012] FIG. 1 is an outer appearance of an optical transceiver
according to an embodiment of the present application;
[0013] FIG. 2 is a perspective view of an inside of the optical
transceiver;
[0014] FIG. 3 is a perspective view of a sub-board that mounts
optical assemblies thereon;
[0015] FIG. 4 is also a perspective view of the sub-board shown in
FIG. 3 but lens assembly appearing in FIG. 3 is removed;
[0016] FIG. 5 is a plan view of a circuit board;
[0017] FIG. 6 is a perspective view of the inside of the optical
transceiver, where the circuit board shown in FIG. 5 mounts
electronic circuits and sub-boards thereon;
[0018] FIG. 7 is a perspective view of an optical receptacle where
an MT ferrule therein is set therein;
[0019] FIG. 8 shows an assembly including the optical receptacle
with the MT ferrule, where the assembly is set in the preset
position of the bottom body of the housing;
[0020] FIG. 9 is an exploded view of the bottom body of the
housing, the optical receptacle, and the MT ferrule;
[0021] FIG. 10 shows the assembly of the optical receptacle and the
MT ferrule, where the assembly is viewed from the front side of the
optical transceiver;
[0022] FIG. 11 is a perspective view showing a plate set within
pockets provided in the housing;
[0023] FIG. 12 is a perspective view of the plate shown in FIG.
11;
[0024] FIG. 13 is a plan view of the inside of the optical
transceiver having a mechanism to push the MT ferrule frontward
according to the second embodiment of the present application;
and
[0025] FIG. 14 magnifies the mechanism provided in the rear of the
MT ferrule to push the MT ferrule frontward.
DESCRIPTION OF EMBODIMENTS
[0026] Next, some embodiments according to the present application
will be described as referring to drawings. In the description of
the drawings, numerals or symbols same or similar to each other
will refer to elements same or similar to each other without
duplicated explanations.
First Embodiment
[0027] An optical transceiver 1 of the present application, as
illustrated in FIG. 1, has a type of, what is called, the CFP
following one of multi-source agreements (MSA) relating to optical
transceivers. The optical transceiver 1, which is primarily
installed in a data center, outputs and receives a plurality of
optical signals via a plurality of optical fibers whose lengths are
several hundred meters at most. The optical transceiver 1
implements with a plurality of vertical cavity surface emitting
laser diodes (hereafter denoted as VCSEL) each emitting an optical
signal with a wavelength shorter than one (1) micron as optical
signal sources. The optical transceiver 1 comprises a housing 2,
two screws 3, and a front cover 4. The housing 2 includes a top
body 5 and a bottom body 6.
[0028] FIG. 2 is a perspective view of an inside of the optical
transceiver 1. As shown in FIG. 2, the optical transceiver 1
encloses between two bodies, 5 and 6, three sub-boards 11 and a
circuit board 12. The sub-boards 11 are electrically connected to
the circuit board 12 with respective flexible printed circuit
boards (hereafter denoted as FPC) 13. Each of the sub-boards 11
mounts optical devices; while, the circuit board 12 mounts an
electronic circuit to drive the optical devices and control the
whole of the optical transceiver 1. The circuit board 12 provides
an electrical plug 12A in a rear end thereof to communicate with
the host system and to be provided with power supplies from the
host system. The description below assumes the directions of
"front", "rear", "top" and "bottom" merely for the explanation
sake. A side where the front cover 4 is provided is the front;
while, another side where the electrical plug 12A is provided is
the rear. Also, a side where the top body 5 is provided is the top;
while, the other side where the bottom body 6 is provided is the
bottom. These directions are only for the explanation sake, and do
not restrict a scope of the present invention.
[0029] Each of sub-boards 11 may be made of, what is called, FR-4
(Flame Retardant Type 4). As shown in FIG. 3, the sub-board 11
provides electrodes 20, interconnections 21, and a lens assembly 22
including two guide pins 23, a Tx port 24, and an Rx port 25. FIG.
4 removes a shell of the lens assembly 22 to show optical devices,
28 and 29, and electrical devices, 26 and 27. Specifically, the
arrayed VCSEL 28 integrates four active elements each driven by the
driver 26; while, an arrayed photodiode (hereafter denoted as
arrayed PD) 29 also integrates four active elements.
[0030] The interconnections 21 are formed on a surface of the
sub-board 11. A portion of the interconnection 21 mounts the
arrayed VCSEL 28 thereon. Each of device elements integrated in the
arrayed VCSEL 28 is independently driven by the driver 26. While,
the pre-amplifier 27 independently amplifies each of photocurrents
generated by respective PD elements in the arrayed PD 29. Those
devices of the driver 26, the pre-amplifier 27, the arrayed VCSEL
28 and the arrayed PD 29 are electrically connected mutually and to
the interconnections 21 by bonding wires. Metal ribbons may be
replaced with the bonding wires. Also, the flip-chip bonding and so
on without using any bonding wires and ribbons are applicable to
the present embodiment.
[0031] The sub-board 11 may also provide alignment marks formed
concurrently with the interconnection 21 by a material same with
the interconnection 21. The alignment mark facilitates the mounting
of the arrange VCSEL 28 and the arrayed PD 29 on the sub-board 11.
An adhesive and conductive resin may fix the optical devices, 28
and 29, to the surface of the sub-board 11. After the mount of the
optical devices, 28 and 29, on the surface of the sub-board 11 and
the electrical connection to the interconnections 21, a lens
assembly 22 shown in FIG. 3, which may be made of resin transparent
to light subject to the optical devices, 28 and 29, typically those
named as ULTEM.TM., covers the optical devices, 28 and 29, and is
mounted on the sub-board 11.
[0032] The lens assembly 22 integrates on a surface thereof a
plurality of lenses each corresponding to respective active element
in the arrayed VCSEL 28 and those in the arrayed PD 29. Optical
beams generated by respective elements in the arrayed VCSEL 28
enter the lens assembly 22 via first lenses, which are collimating
lenses. The optical beams entering the lens assembly 22 are
internally reflected toward the Tx port 24 at a surface with an
angle of 45.degree. with respect to the primary surface of the
sub-board 11. Second lenses, concentrating lenses, are provided
between the reflecting surface and the Tx port 24 to concentrate
the optical beams onto the ends of the internal fiber F.
[0033] The guide pin 23 guides an MT ferrule 15. Specifically, the
guide pins 23 provided in respective sides of the front surface of
the lens assembly 22 are inserted into bores provided in the MT
ferrule 15 such that the inner fibers F secured in the MT ferrule
15 align with the lenses provided within the front hollow of the
lens assembly 22. Also, the alignment of the lens assembly 22 with
the optical devices, 28 and 29, mounted on the surface of the
sub-board 11 is performed by mating pins provided in the bottom
surface of the lens assembly 22 into the holes 11A provided in
immediate sides of the optical devices, 28 and 29. Or, the optical
alignment between the lens assembly 22 and the optical devices, 28
and 29, may be carried out by mating a temporal MT ferrule with the
guide pins 23 and practically activating the optical devices, 28
and 29, such that the optical beams detected via the optical fibers
secured in the temporal MT ferrule become optimum. After the
optical alignment between the lens assembly 22 and the optical
devices, 28 and 29, on the sub-board 11, the lens assembly 22 is
permanently fixed to the sub-board 11 by, for instance, epoxy
resin.
[0034] FIG. 5 is a plan view of the circuit board 12. The circuit
board 12 includes three portions, 31 to 33, namely, the fiber
disposing region 31, the circuit region 32, and the plug region 33.
The circuit board 12 further provides holes 34 for fastening clips
to fasten the fiber thereby and an opening 35 into which the
sub-boards 11 are set. The opening 35 is provided between the fiber
disposing region 31 and the circuit region 32.
[0035] The fiber disposing region 31 sets the inner fibers F
therein; while, the circuit region 32 mounts circuit components on
the top and back surfaces of the circuit board 12. The circuit
region in the front end thereof facing the opening 35 provides a
plurality of electronic pads 32A for the FPC board 13 connecting
the circuit board 12 with the sub-board 11. The plug region 33 in
the rear end of the circuit board 12 provides electronic plugs 12A
also in the top and back surfaces, where FIG. 5 removes the plugs
explicitly.
[0036] The inner fibers F are arranged in the fiver disposing
region 31 so as to secure the bending curvature larger than 15 mm.
Clips set in the holes 34 may assist the arrangement of the inner
fiber F in the fiber disposing region 31 by fastening them.
[0037] FIG. 6 is a perspective view showing an inside of the
optical transceiver 1, where the top body 5 is removed to show the
inside. The space 40 formed between the top and bottom bodies, 5
and 6, are roughly divided into three portions, 41 to 43, namely, a
receptacle portion 41, an active portion 42, and a fitting portion
43. The receptacle portion 41 provides in the bottom body 6 thereof
an optical receptacle 60 that receives an external MPO connector
(Multiple-fiber Push-ON) and is made of resin, typically,
ULTEM.TM..
[0038] FIGS. 7 to 9 explain details of the optical receptacle 60
and structures of the bottom body 6 around the optical receptacle
60. The optical receptacle 60 provides a rectangular opening 61 in
the rear thereof that receives an MT ferrule 50 secured in another
end of the inner fibers F. While, the front of the optical
receptacle 60 provides another opening 62 that receives the
external MPO connector which is not explicitly illustrated in the
figures. The shape of the front opening 62 traces the outer shape
of the MPO connector. The MT ferrule 50 to be mated with the
optical receptacle 60 secures a plurality of inner fibers F.
Specifically, as shown in FIGS. 2 and 6, the present optical
transceiver 1 provides three optical subassemblies each mounted on
the sub-boards 11. Two of sub-assemblies output four optical beams
and receive also four optical beams; while, the rest of
sub-assemblies outputs two optical beams and receives two optical
beams, where each of the optical beams is carried on an inner fiber
F. That is, the optical transceiver 1 provides ten (10) inner
fibers F for transmitting optical beams and other ten (10) inner
fibers F for receiving optical beams. The MT ferrule 50 secures
these twenty (20) inner fibers F and the inner fibers F are
disposed in the fiber disposing region 31 and spaces provided in
both sides of the optical receptacle 60 so as to secure the
curvature greater than 15 mm.
[0039] Referring to FIG. 7 that shows the rear of the optical
receptacle 60, the optical receptacle 60 provides in both sides
thereof a flange 63 extending in substantially perpendicular to the
optical axis of the optical receptacle 60. The flange 63 has two
projections 63a in the top and the bottom thereof, that is, the
optical receptacle 60 provides total four (4) projections 63a in
respective sides thereof. These projections 63a are set in the
guides 41A formed in the bottom body 6. Thus, the optical
receptacle 60 is positioned with respect to the bottom body 6.
[0040] The flange 63 further provides, between up and bottom
projections 63a, a tab 64 extending rearward and outward, which
induces a repulsive force when the optical receptacle 60 is set in
a space 41B by abutting against the side wall 41a surrounding the
space 41B. Thus, the optical receptacle 60 is stably set within the
space 41B even when the external MPO connector is set within the
optical receptacle 60.
[0041] The MT ferrule 50, when it mates with the optical receptacle
60, abuts in rear surface thereof against the terrace 41C provided
in the rear end of the space 41B to position of the optical
receptacle 60 along the optical axis securely. That is, the terrace
41C assists to securely determine the optically reference surface,
which is the front surface of the MT ferrule 50 with an enough
accuracy.
[0042] As illustrated in FIGS. 9 and 10, the MT ferrule 50 provides
guide pins 51 piercing the body thereof to mate and align optically
with the external MPO connector. That is, the external MPO
connector provides holes to receive the guide pins 51. Inserting
the guide pins 51 into those holes in the MPO connector, the inner
fibers F secured in the MT ferrule 50 and exposed in the surface of
the MT ferrule 50 may optically couple with external fibers secured
in the MPO connector. The front surface of the MT ferrule 50, at
which the inner fibers F expose, becomes the optical reference
plane. The guide pins 51 protruding rearward of the body of the MT
ferrule 50 assists the positioning of the MT ferrule 50 in the
space 41B. As described above, the MT ferrule 50 optically couples
with the external MPO connector by setting the guide pins 51 into
the holes of the MPO connector. Specifically, the MPO connector
provides an MT ferrule therein with a female type, namely, having
holes to receive guide pins. Inserting the MT ferrule 50 into the
MPO connector, the guide pins 51 mate with the female holes in the
other MT ferrule in the MPO connector and the optical fibers
exposed in the front surface of the MT ferrule 50 may optically
couple with the external fibers secured in and exposed at the
surface of the other MT ferrule in the MPO connector. As described
above, the MT ferrule 50 secures a plurality of fibers, 20 fibers
are secured and expose at the surface of the MT ferrule 50 in the
present embodiment. The other MT ferrule in the MPO connector also
secures 20 external fibers. In order to couple these 20 fibers in
the MT ferrule 50 stably with external fibers in the MPO connector,
the front surface of the MT ferrule 50 and that of the external MT
ferrule are necessary to be abutted evenly and homogeneously in the
whole front surface. Accordingly, the MT ferrules are preferably to
be elastically abutted.
[0043] The optical transceiver 1 of the present embodiment provides
a plate 70 not only to induce an elastic force against the MT
ferrule 50 but to shield the inside of the optical transceiver 1
electrically. FIGS. 11 and 12 explain details of the plate 70 and
structures around the plate 70 provided in the bottom body 6.
Referring to FIG. 11, the plate 70 is set within the pocket 41D
formed behind the space 41B for the optical receptacle 60. That is,
the housing 2 provides two pockets 41D putting the terrace 41C
therebetween. The plate 70 is set in the pockets 41D so as to
stride over the terrace 41C. The plate 70 set in the pocket 41D is
put between the rear surface of the MT ferrule 50 and the rear wall
of the pocket 41D, by which the inside of the optical transceiver 1
where the optical and electrical devices are enclosed may be
electrically isolated from the outside.
[0044] Referring to FIG. 12, the plate 70 includes a plane portion
71, and two legs 72 extending from the lower edge of the plane
portion 71. These two legs 72 and the plane portion 71 forms a cut
70A between legs 72. The top edge of the cut 70A further provides a
cut 71A to pass the inner fibers F and other cuts 71B in respective
sides of the former cut 71A to pass the guide pin 51. The latter
cut 71B has two portions, one of which 71a extends upwardly from
the top edge of the cut 70A as narrowing a span thereof, and a
circular opening 71b continuous from the former portion 71a. The
root of the leg 72 and bent portions, 72A to 72C, form a U-shaped
cross section. The circular portion 71b has a diameter slightly
smaller than the diameter of the guide pin 51.
[0045] The legs 72 are bent three times. Specifically, the legs 72
are first bent rearward at the outer edge thereof to form the first
portion 72A, bent inwardly to form the second portion 72B, and
further bend inwardly to form the third portion 72C. The third
portion 72C extends substantially in parallel to the plane portion
71. The height of the second portion 72B gradually decreases toward
the third portion 72C, and the third portion 72C is substantially
rectangular.
[0046] Thus, the plate 70, when it is set in the pocket 41D such
that the plane portion 71 strides across the terrace 41C, the third
portion 72C abuts against the rear wall of the pocket 41D, the
plane portion 71 pushes the rear surface of the MT ferrule 50
frontward. Moreover, because the plate 70 is formed only by cutting
and bending a metal sheet without using soldering, welding and so
on, the plate 70 becomes a cost effective component.
[0047] Thus, the optical transceiver 1 of one of embodiments of the
present application is described in detail. The optical transceiver
1 has a feature that it provides the plate 70 set in the rear end
of the optical receptacle 60 to shield the space S and the inside
where the optical and electrical devices are installed. The
electro-magnetic interference EMI is effectively suppressed.
Moreover, the plate 70 shows the repulsive force against the MT
ferrule 50 set in the optical receptacle 60 when the plate 70 is
set in the pocket 41D, which effectively abuts the front surface of
the MT ferrule 50 against the front surface of the external MT
ferrule secured in the MPO connector. Thus, the inner fibers F may
be stably and evenly coupled with the external fibers.
[0048] The plate 70 provides the cut 71A to pass the inner fibers F
therethrough, and other cuts 71B provided in respective sides of
the former cut 71A to pass the guide pins 51 extending from the MT
ferrule 50. These cuts, 71A and 71B, form openings combined with
the terrace 41C provided in the rear of the pocket 41D. Moreover,
the openings attributed to two cuts, 71A and 71B, have areas
narrower as possible to enhance the EMI shielding.
Second Embodiment
[0049] Next, another optical transceiver 101 according to the
second embodiment of the present application will be described as
referring to FIGS. 13 and 14.
[0050] FIG. 13 is a plan view showing the inside of the optical
transceiver 101 of the second embodiment. The optical transceiver
101 provides another bottom body 106 that includes a modified
receptacle portion 141 with a mechanics 170 to push the MT ferrule
50 in the optical receptacle 60 instead of the plate 70 in the
former embodiment. Other arrangements of the modified optical
transceiver 101 are substantially same as those of former
embodiment 1.
[0051] The receptacle portion 141 of the present embodiment shown
in FIGS. 13 and 14, removes the terrace 41C. Instead of the terrace
41C, the receptacle portion 141 provides a hollow 141D to receive
the mechanism 170 therein. The mechanism 170 includes a holder 171
with a rectangular shape to hold the MT ferrule 50 and a spring 172
to push the holder 171 against the MT ferrule 50. The holder 171,
which covers the rear portion of the body of the MT ferrule 50,
provides the first opening 171A to pass the inner fibers F
therethrough and the second openings 171B to pass the guide pins 51
in respective sides of the former opening 171A.
[0052] The spring 172 is set in the hollow 141D in a state slightly
offset from an equilibrium condition, namely, the spring 172 is set
in a slightly compressed state. The inner fibers F extracting from
the MT ferrule 50 pass the opening 171A of the holder 171, the
spring 172, and the cut 141E provided in the rear wall of the
hollow 141D to be drawn within the inner space of the optical
transceiver 101. Because the elastic constant of the spring 172 is
usually greater than that of the leaf spring of the legs 72, the
spring 172 may give a greater force to push the MT ferrule 50
forward, which enhances the performance of the optical coupling
between two front faces of the MT ferrules. The MPO connector set
in the optical receptacle 60 has a spring therein to push the MT
ferrule forwardly. The elastic member, 72 or 172, in the optical
transceiver, 1 or 101, is necessary to counter the force caused by
the MPO connector. The spring 172, namely, the coil spring may
effectively meet the force induced by the MPO connector.
[0053] The MT ferrule 50, when it is held by the mechanism 170 and
this mechanism 170 is set in the hollow 141D, is pushed forward to
abut against the optical receptacle 60. The hollow 141D has a depth
greater than the diameter of the spring 172, which effectively
prevents the spring 172 from slipping out from the hollow 141D.
[0054] Referring to FIG. 14, the optical transceiver 101 of the
present embodiment further provides a gasket 141F arranged around
the hollow 141D. The gasket 141F, which is made of electrically
conductive and elastic material such as conductive rubber, is
arranged so as to trace the edges of the hollow 141D. Accordingly,
the arrangement of the mechanism 170 with the gasket 141F not only
makes the performance of the MPO connector, namely, the optical
coupling between many fibers, but secures the electrical shielding
function.
[0055] In the foregoing detailed description, the optical
transceiver of the present application has been described with
reference to specific exemplary embodiments thereof. It will,
however, be evident that various modifications and changes may be
made thereto without departing from the broader spirit and scope of
the present invention. The present specification and figures are
accordingly to be regarded as illustrative rather than
restrictive.
* * * * *