U.S. patent application number 09/996815 was filed with the patent office on 2002-08-29 for method and system for automatic handling of optical assemblies.
Invention is credited to Maganti, Srikanth S., Nadeau, Mary J., Scott, Dane, Stackhouse, Duane S., Wolf, Robert K..
Application Number | 20020117571 09/996815 |
Document ID | / |
Family ID | 27402331 |
Filed Date | 2002-08-29 |
United States Patent
Application |
20020117571 |
Kind Code |
A1 |
Scott, Dane ; et
al. |
August 29, 2002 |
Method and system for automatic handling of optical assemblies
Abstract
Systems and methods are used for automatic handling of optical
fibers and transporting the same, as well as automatic assembly of
the optical fibers into optical devices and transportation of the
same. A spool facilitates handling, storing, and transporting of
the optical fiber. A cassette receives an electronic module and the
optical fiber, with or without a corresponding spool, and presents
the fiber in a manner that facilitates automatic assembly of
optical assemblies. The cassette also facilitates handling,
storing, and transporting of the optical assemblies.
Inventors: |
Scott, Dane; (Daylestown,
PA) ; Maganti, Srikanth S.; (Drifton, PA) ;
Wolf, Robert K.; (Fleetwood, PA) ; Stackhouse, Duane
S.; (Coopersburg, PA) ; Nadeau, Mary J.;
(Alburtis, PA) |
Correspondence
Address: |
DANIEL H. GOLUB
1701 Market Street
Philadelphia
PA
19103
US
|
Family ID: |
27402331 |
Appl. No.: |
09/996815 |
Filed: |
November 30, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60270980 |
Feb 23, 2001 |
|
|
|
60270979 |
Feb 23, 2001 |
|
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|
Current U.S.
Class: |
242/388 ;
191/12.2R; 242/400.1 |
Current CPC
Class: |
G02B 6/4453 20130101;
G02B 6/4219 20130101; G02B 6/4457 20130101 |
Class at
Publication: |
242/388 ;
242/400.1; 191/12.20R |
International
Class: |
B65H 075/38 |
Claims
What is claimed is:
1. A spool assembly used in connection with automatic assembly
equipment for capturing a length of optical fiber comprising: a
drum for receiving said length of optical fiber, said length of
optical fiber comprising a first end and a second end; and a spool
base, coupled to said drum, comprising at least two fiber end areas
for retaining said first end and said second end.
2. A spool assembly used in connection with automatic assembly
equipment for capturing a length of optical fiber comprising: a
drum for receiving said length of optical fiber, said length of
optical fiber comprising a first end and a second end; and a spool
base, coupled to said drum, comprising: a fiber connector area for
retaining said first end and presenting said first end for
connection to a light source or light sensor; and a module
connection area for retaining said second end and presenting said
second end for automatic connection to an electronic module.
3. The spool of claim 1 or 2 wherein said drum and said spool base
comprise a single unit.
4. The spool of claim 1 or 2 wherein said drum comprises a central
axis and wherein a plurality of said spools are coupled along said
central axis.
5. The spool of claim 2 wherein at least a portion of said fiber
connector area is formed as an insert for coupling to said spool
base.
6. The spool of claim 2 wherein said fiber connector area comprises
a connector clip for capturing said first end.
7. The spool of claim 2 wherein at least a portion of said module
connection area is formed as an insert for coupling to said spool
base.
8. The spool of claim 2 wherein said module connection area
comprises a fiber end cover.
9. The spool of claim 2 wherein said module connection area
comprises a fiber end latch for capturing said second end.
10. The spool of claim 9 wherein, upon deactivating said fiber end
latch, said second end is released for attachment to said
electronic module.
11. The spool of claim 1 or 2 wherein said spool is configured to
facilitate automatic alignment of said length of optical fiber.
12. The spool of claim 1 or 2 wherein said spool facilitates
transportation of said length of optical fiber.
13. The spool of claim 1 or 2 wherein said spool facilitates
manipulation of said length of optical fiber by automatic assembly
equipment.
14. The spool of claim 1 or 2 wherein said spool facilitates
storage of said length of optical fiber.
15. The spool of claim 1 wherein at least a portion of at least one
of said fiber end areas are formed as inserts for coupling to said
spool base.
16. A cassette that facilitates automatic assembly of an
electro-optical device, wherein said device comprises at least one
length of optical fiber and an electronic module, comprising: an
electronic module receiving area that receives said electronic
module; and a fiber receiving area comprising a drum for receiving
said at least one length of optical fiber, said length of optical
fiber having a first end and a second end; wherein said fiber
receiving area comprises a fiber connector area for receiving said
first end and for presenting said first end for connection to a
light source or light sensor and a module connection area for
receiving said second end and for presenting said second end for
automatic connection to said electronic module.
17. A cassette that facilitates automatic assembly of an
electro-optical device, wherein said device comprises at least one
length of optical fiber and an electronic module, comprising: an
electronic module receiving area that receives said electronic
module; and a spool receiving area that receives at least one spool
for carrying said length of optical fiber, said length of optical
fiber having a first end and a second end; wherein said at least
one spool comprises a fiber connector area for receiving said first
end and for presenting said first end for connection to a light
source or light sensor and a module connection area for receiving
said second end and for presenting said second end for automatic
connection to said electronic module.
18. The cassette of claim 17 wherein said electronic module
receiving area facilitates automatic connection of said electronic
module to an electrical power source.
19. The cassette of claim 17 wherein said electronic module
receiving area comprises an electronic module cover for securing
said electronic module.
20. The cassette of claim 17 wherein said fiber connector area is
configured to facilitate automatic alignment of said length of
optical fiber.
21. The cassette of claim 20 wherein said automatic alignment
facilitates testing of said length of optical fiber.
22. The cassette of claim 17 wherein said cassette facilitates
storage of said electro-optical device.
23. The cassette of claim 17 wherein said cassette facilitates
shipping of said electro-optical device.
24. A method for automatically assembling a spool that transports
of a length of optical fiber, said length of optical fiber having a
first end and a second end, wherein said spool comprises a drum and
a spool base, wherein said spool base comprises at least two fiber
end areas for retaining said first end and said second end, said
method comprising the steps of: (A) retaining said first end in one
of said fiber end areas; (B) winding said length of optical fiber
around said drum; and (C) retaining said second end in a second of
said fiber end areas.
25. A method for automatically assembling a spool that transports
of a length of optical fiber, said length of optical fiber having a
first end and a second end, wherein said spool comprises a drum and
a spool base, wherein said spool base comprises a fiber connector
area, wherein said fiber connector area comprises a connector clip,
and a module connection area, wherein said module connection area
comprises a fiber end latch, said method comprising the steps of:
(A) inserting said first end into said connector clip; (B) winding
said length of optical fiber around said drum; and (C) inserting
said second end in said fiber end latch.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional
Application Serial No. 60/270,980 entitled "Fiber Cassette" and
U.S. Provisional Application Serial No. 60/270,979 entitled
"Optical Fiber Spool and Cassette", both filed Feb. 23, 2001.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to systems and methods for
automatic handling of optical fibers, transporting the fibers, and
automatically assembling the optical fibers into optical devices,
including attaching the fibers to electro-optical modules. The
present invention also relates to automatic handling of optical
assemblies and their transportation.
[0004] 2. Description of the Background
[0005] In the production of optical systems including
electro-optical systems, certain components must be optically
connected to other components. This optical connection is typically
accomplished by using flexible optical fibers with connectors on
their ends. The use of a connector in such systems, however,
generates a degradation of the signal either in a reduction of
power or in added distortion. This is referred to as insertion
loss. In many optical devices, therefore, one end of the fiber is
connected directly to an electronic unit in order to eliminate one
connector and reduce the system's insertion loss. This is normally
done by the use of flexible optical fibers such as pigtails.
Pigtails are glass fibers with specified coatings and have
connectors installed on one end. They are normally obtained in
lengths from a few inches to several feet. These fibers can be
obtained with many different end terminations and are typically
very fragile. Most of these fibers, for instance, cannot be bent in
a curve with a radius that is less than 1.5 inches without
suffering significant damage. The weight of typical end
terminations on most pigtails presents a substantial risk of fiber
damage during transportation and assembly. Also, the bare ends of
fibers that are subject to direct connection are very fragile and
must be protected from contact with any external surface at all
times.
[0006] In order to assemble electro-optical systems, optical fibers
are initially shipped from a fiber manufacturer. In connection with
the shipping process, optical fibers undergo multiple manual
processes. Optical fibers are normally air coiled, placed
individually in plastic bags, and shipped from a vendor to a module
manufacturer. There, the individual optical fiber is again
subjected to numerous manual processes. The fiber packaging is
opened manually. The optical fibers are uncoiled manually. The
optical fibers are placed into equipment for manual assembly. These
manual processes, particularly the shipping process and the
assembly process, present a strong risk of damage to optical
fibers. The fragile nature of pigtails, in particular, requires
operator dexterity and does not lend itself to handling equipment
normally used in automated assembly.
[0007] Once incorporated into an electro-optical assembly, in which
a fiber is attached to an electronic module, the fiber is handled
and shipped again. Once the fiber has been attached to an
electronic module, however, its exposure to a substantial risk of
damage increases. Handling the device, while these delicate fibers
are hanging freely, and making connections to the attached fiber
numerous times for fiber alignment and unit testing, generates a
high probability of fiber fracture. Thus, the shipping of the
finished device, with its attached fibers, typically requires
manual manipulation of the fibers in properly sized loops and some
method of immobilizing the fibers with respect to the body of the
module. The device and the attached optical fibers must be placed
in properly designed packing material. Fiber motion during shipment
to the end user can generate defective units that may appear to be
of high quality, but will not function properly in service.
[0008] In order to minimize the above-referenced risks, extreme
care in handling during shipping and assembling is required.
Nevertheless, small fractures can occur in the optical fibers that
may not reveal themselves until the fracture grows sufficiently
large to degrade the passage of light. This results in a reduction
in the lifetime of the electro-optical assembly with the necessity
of early unit replacement and resultant cost implications. Thus,
there exists a need for a system and method for handling,
transporting, and assembling optical fibers and optical assemblies,
including electro-optical assemblies, that overcome the problems
present in the prior art.
BRIEF SUMMARY OF THE INVENTION
[0009] The present invention is directed to a spool assembly to be
used in connection with automatic assembly equipment, which
captures a length of optical fiber having a first end and a second
end. The spool includes a drum for receiving the optical fiber. The
spool also includes a spool base, coupled to the drum, which
includes at least two fiber end areas for retaining the first and
second ends. The present invention is also directed to a spool
assembly to be used in connection with automatic assembly
equipment, which captures a length of optical having a first end
and a second end. The spool includes a drum for receiving the
length of optical fiber and a spool base, coupled to the drum. The
spool base includes a fiber connector area, for retaining the first
end and presenting the first end for connection to a light source
or light sensor, and a module connection area, for retaining the
second end and presenting the second end for automatic connection
to an electronic module.
[0010] The present invention is also directed to cassette that
facilitates automatic assembly of an electro-optical device that
includes at least one length of optical fiber (having a first end
and a second end) and an electronic module. The cassette includes
an electronic module receiving area that receives the electronic
module and a fiber receiving area that includes a drum for
receiving the length of optical fiber. The fiber receiving area
includes a fiber connector area, for receiving the first end and
for presenting the first end for connection to a light source or
light sensor, and a module connection area, for receiving the
second end and for presenting the second end for automatic
connection to the electronic module.
[0011] The present invention is further directed to a cassette that
facilitates automatic assembly of an electro-optical device that
includes at least one length of optical fiber (having a first end
and a second end) and an electronic module. The cassette includes
an electronic module receiving area that receives the electronic
module and a spool receiving area that receives at least one spool
for carrying the length of optical fiber. The at least one spool
includes a fiber connector area, for receiving the first end and
for presenting the first end for connection to a light source or
light sensor, and a module connection area, for receiving the
second end and for presenting the second end for automatic
connection to the electronic module.
[0012] The present invention is also directed to a method for
automatically assembling a spool that transports of a length of
optical fiber that has a first end and a second end. The spool
includes a drum and a spool base, wherein the spool base includes
at least two fiber end areas for retaining the first end and the
second end. The method includes retaining the first end in one of
the fiber end areas; winding the length of optical fiber around the
drum; and retaining the second end in a second of the fiber end
areas.
[0013] The present invention is also directed to a method for
automatically assembling a spool that transports of a length of
optical fiber having a first end and a second end. The spool
includes a drum and a spool base. The spool base includes a fiber
connector area, which includes a connector clip, and a module
connection area, which includes a fiber end latch. The method
includes inserting the first end into the connector clip; winding
the length of optical fiber around the drum; and inserting the
second end into the fiber end latch.
BRIEF DESCRIPTION OF FIGURES
[0014] The accompanying drawings, wherein like reference numerals
are employed to designate the same or similar parts or steps, are
included to provide a further understanding of the invention, are
incorporated in and constitute a part of this specification, and
illustrate embodiments of the invention that, together with the
description, serve to explain the principles of the invention:
[0015] FIG. 1 shows a preferred embodiment of a spool assembly in
accordance with the present invention.
[0016] FIG. 2 is an isometric, partially exploded view of a spool
assembly in accordance with a preferred embodiment of the present
invention.
[0017] FIG. 3 is an isometric view of a preferred embodiment of a
spool assembly in accordance with the present invention.
[0018] FIG. 4 is an isometric, exploded view of a preferred
embodiment of a spool assembly in accordance with the present
invention.
[0019] FIG. 5 is an isometric view of a preferred embodiment of a
spool assembly in accordance with the present invention.
[0020] FIG. 6 is an isometric view of a preferred embodiment of a
spool assembly in accordance with the present invention.
[0021] FIG. 7 is an isometric view of a preferred embodiment of a
two-spool assembly with one spool assembly partially exposed, in
accordance with the present invention.
[0022] FIG. 8 is an isometric, exploded view of a preferred
embodiment of a cassette assembly in accordance with the present
invention.
[0023] FIG. 9 is an isometric, exploded view of a preferred
embodiment of a cassette assembly in accordance with the present
invention.
[0024] FIG. 10 is an isometric view of a preferred embodiment of a
cassette assembly in accordance with the present invention.
[0025] FIG. 11 is an isometric, exploded view of a preferred
embodiment of a cassette assembly in accordance with the present
invention.
[0026] FIG. 12 is an isometric view of a preferred embodiment of a
cassette assembly in accordance with the present invention.
[0027] FIG. 13 is a view of a preferred embodiment of a cassette
assembly in accordance with the present invention.
[0028] FIG. 14A is an isometric view of a preferred embodiment of a
cassette assembly in accordance with the present invention.
[0029] FIG. 14B is an isometric view of a preferred embodiment of a
cassette assembly in accordance with the present invention.
[0030] FIG. 15 is an isometric view of a preferred embodiment of a
cassette assembly in accordance with the present invention.
[0031] FIGS. 16A and 16B are flow charts illustrating a method for
automatically assembling an electro-optical device in accordance
with a preferred embodiment of the present invention.
[0032] FIGS. 17A, 17B and 17C are flow charts illustrating a method
for automatically assembling an electro-optical device in
accordance with a preferred embodiment of the present
invention.
[0033] FIG. 18 is a flow chart illustrating a method for assembling
a spool in accordance with a preferred embodiment of the present
invention.
DETAILED DESCRIPTION
[0034] Reference will now be made in detail to the preferred
embodiments of the present invention, examples of which are
illustrated in the accompanying drawings. It is to be understood
that the Figures and descriptions of the present invention included
herein illustrate and describe elements that are of particular
relevance to the present invention while eliminating, for purposes
of clarity, other elements.
[0035] In one aspect of the present invention, a spool facilitates
automatic handling of one or more lengths of optical fiber and can
be used for storing, shipping, and further processing of the
optical fibers, including facilitating manipulation of the optical
fibers by automatic assembly equipment. With reference to FIG. 1, a
spool assembly (1) is shown, which captures a length of optical
fiber (2). Spool assembly (1) includes a drum (3) that receives the
length of optical fiber (2). The length of optical fiber (2) has a
first end (4) and a second end (5). Spool assembly (1) also
includes a spool base (6), coupled to the drum (3). Spool base (6)
includes at least two fiber end areas, fiber end area (7) and fiber
end area (8), which retain the first end (4) and the second end (5)
and prevent the length of optical fiber (2) from unspooling. At
least a portion of fiber end area (7) and/or fiber end area (8) can
be formed as inserts to accommodate various different types of
fiber end configurations. Spool assembly (1) is sized and configure
such that it is capable of being used in connection with automatic
assembly equipment.
[0036] The general configuration of the spool described with
reference to FIG. 1 can be used to accommodate many different types
of assemblies. For example, this general configuration may
accommodate an optical fiber with a connector or electronic element
(such as a laser, lamp, diode, or sensor) on one end while leaving
the other end bare. Alternatively, the spool may be configured to
accommodate an optical fiber with connectors/electronic elements on
each of its ends or, conversely, an optical fiber with two bare
ends. Thus, the spool may be configured to accommodate fibers that
are already connected to electronic elements; fibers that are
connected to other fibers by splicing; or fibers that simply must
be prevented from tangling in subsequent operations or during use.
These accommodations may be easily achieved by changing the
configuration of fiber end area (7) and/or fiber end area (8).
Forming at least a portion of fiber end area (7) and/or fiber end
area (8) as inserts is particularly advantageous in this
regard.
[0037] The following describes some specific preferred embodiments
of the invention. As shown in FIG. 2, spool assembly (101)
comprises a drum (120) and a spool base (150). The drum (120),
which is used for receiving optical fibers, is coupled to the spool
base (150) along the drum central axis (122) and the spool base
central axis (152). The drum (120) and the spool base (150) can be
formed as two separate units or, as shown in FIG. 3, as a single
integrated unit. When made as separate units, as shown in FIG. 2, a
drum molding (151) is used for coupling the drum (120) to the spool
base (150). Drums, such as drum (120), can be constructed in
different sizes to accommodate optical fibers of different lengths
and diameters and coupled to the spool base (150) using the drum
molding (151). In addition, this design allows for the substitution
of different types of spool bases and corresponding fiber end
entrapments, as discussed in more detail with reference to FIGS. 3
and 4.
[0038] As shown in FIG. 3, the spool assembly (102) includes a
length of optical fiber (10). The drum (120) has flanges (121) to
maintain the length of optical fiber (10) securely on the drum
(120). In another embodiment, shown in FIG. 4, the drum (123) has a
concave surface (125) on its outer diameter that retains the length
of optical fiber. One end of the length of optical fiber (10) is
held by a connector (15). The length of optical fiber (10) is wound
around the drum (120) and the connector (15) is inserted in the
connector clip (131) and held by connector locks (132). The
connector clip (131) may be integral with the spool base (150) or
may be formed as an insert, which allows for the use of different
connector end configurations by inserting the particular connector
clip that matches the desired connector end configuration. The
spool assembly of the present invention, therefore, is versatile
and enables accommodation of different pigtail terminations. The
connector (15) is presented in fiber connector area (130) in a
manner that allows for connection of connector (15) to a light
sensor (if the electrical unit to which the fiber is to be
connected is a transmitter) or a light source (if the electrical
unit to which the fiber is to be connected is a receiver).
Connector (15) may be connected to the light source/sensor by
automatic assembly equipment. Alternatively, in some embodiments,
connector (15) may be precisely positioned in fiber connector area
(130) such that connection to a light source/sensor can be made
without need for automatic assembly equipment.
[0039] As shown in FIG. 4, in module connection area (140) of the
spool assembly (103), the assembly end (12) of the optical fiber
(10) can be asserted into the fiber end latch (141). In particular,
the bend limiter (13) on the assembly end (12) may be held in the
fiber end latch (141) such that ferrule (14) is available for
gripping by an assembly machine prior to its release from the latch
(141) during optical assembly. Exerting pressure on tab (143)
allows for release of the assembly end (12) from the latch (141).
Upon its release, fiber end (16) can be, if required, automatically
connected to an electronic module by an assembly machine. When
maintained in the fiber end latch (141), the fiber end (16) is
protected by the fiber end cover (142). The fiber end latch (141)
may be constructed as an insert, which allows for the use of
different end terminations by inserting the particular fiber end
latch that matches the desired end termination.
[0040] In accordance with the present invention, the spool
assembly, such as that shown in FIG. 4, facilitates bonding of the
optical fiber end to an electronic module (although, as stated
previously, the invention covers spool systems that do not include
electronic elements). For example, as shown in FIG. 4, the optical
bench adapter (145) may be used to facilitate epoxy bonding during
electro-optical assembly. The fiber end (16) held in the fiber end
latch (141) may be released upon exerting pressure on the tab (143)
of the fiber end latch (141). Upon release, as shown in FIG. 5,
fiber end (16) may be inserted into optical bench (146), which is
held in optical bench adapter (145). The optical bench adapter
(145) may be constructed as an insert, which allows for the use of
different bonding methods by inserting the desired optical bench
adapter (145) into module connection area (140).
[0041] FIG. 6 depicts an alternate embodiment of the spool assembly
of the present invention that provides for a different arrangement
of module connection area (140), thereby facilitating a second type
of optical fiber bonding. Module connection area (140) of spool
assembly (104) is designed to facilitate assembly by laser welding.
Electronic unit (148) is typically held by assembly equipment in a
fixture appropriate for laser welding. The assembly end (12) held
in the fiber end latch (141) is released upon exerting pressure on
the tab (143). Automatic assembly equipment then properly positions
fiber end (16) (not shown) with respect to the fixtured electronic
unit (148), perform the weld, and removes the electronic unit (148)
from the fixture with the fiber attached. The assembly equipment
then deactivates latch (147) and inserts the electronic module
(148) with the fiber end (16) attached into module adapter (149).
Once the electronic module (148) and the attached fiber are in
place, the latch (147) is activated, securely holding them in
place. As shown in the FIG. 6, latch (147) may also be constructed
as an insert, thereby providing for additional versatility.
[0042] The ability to form different portions of the spool
assemblies of the present invention as inserts results in great
versatility and enables accommodation of different connections
and/or bonding methods.
[0043] Two or more spools can be coupled together for use in
handling or transporting optical fibers and assembling such optical
fibers into optical assemblies (such as, for example, modulators,
comb filters, multiplexers, frequency multipliers, amplifiers and
other similar optical systems), in accordance with the present
invention. As shown in FIG. 7, two spools (106A & 106B) are
coupled to each other along the central axes (119A & 119B) of
their respective drums (190A & 190B). Each connector (15A &
15B) is inserted into its respective connector clip (131A &
131B), thereby positioned for automatic connection to assembly
equipment, if necessary. Each ferrule (14A & 14B) is positioned
for automatic pickup by assembly equipment.
[0044] Once an optical fiber has been captured on a spool, the
spool can be used to store the optical fiber and to ship the
optical fiber, for example, from a vendor to an assembly facility
where the optical fiber will be automatically integrated into an
optical assembly. In addition, the spool serves to maintain and
align the fiber during testing operations at which time light is
propagated through the fibers, without manual manipulation.
[0045] A multiple-spool assembly, such as that shown in FIG. 7, or
a single spool assembly, such as those shown in FIGS. 1-6, can be
inserted into a cassette, as described more fully with reference to
FIGS. 8-10, 14B, 14A and 15. As shown in FIG. 8 illustrating
cassette assembly (201), a cassette (200) is designed to capture
and retain an electronic module (221) and, in the illustrated
embodiment, two spools (107A & 107B). The cassette (200)
facilitates assembly and transportation of optical assemblies
(comprising, in this illustration, two optical fibers (10A &
10B) and an electronic module (221)). Thus, the cassette assembly
(201) performs double duty as a fixture for retaining the
electronic module (221), bonding fiber ends (16A and 16B) to
electronic module (221), and presenting the fiber connectors (15A
& 15B) for connection to a light source/sensor, as well as a
protective device for shipment of finished assemblies.
[0046] With reference to FIG. 9, illustrating an exploded view of a
cassette assembly (202), cassette (200) comprises a spool receiving
area (250) for receiving one or more spools (108A & 108B). The
spools (108A & 108B) may be retained securely in the spool
receiving area (250) by spool latches (251). The fiber connector
(15B) may be inserted into the connector clip (131B) and the fiber
end (16B) of the assembly end (12B) may be inserted into the fiber
end latch (141B). The connector clip (131B) and the fiber end latch
(141B) may be inserted in the spool (108B) at connector clip insert
(1310 B) and fiber end latch insert (1410B), respectively.
Furthermore, the optical bench adapter (145B) may be inserted in
the spool (108B) at optical bench adapter insert (1450B).
Similarly, fiber connector (15A) may be inserted into the connector
clip (131A) and the fiber end (16A) of the assembly end (12A) may
be inserted into the fiber end latch (141A). The connector clip
(131A) and the fiber end latch (141A) may be inserted in the spool
(108A) at connector clip insert (1310A) and fiber end latch insert
(1410A), respectively. The optical bench adapter (145A) may be
inserted in the spool (108A) at optical bench adapter insert
(1450A). Typically, optical bench (146) is obtained from a storage
device by automatic assembly equipment and placed into a fixture.
Assembly end (12A) is taken from fiber end latch (141A) by the
assembly equipment, aligned to the fixtured optical bench (146),
and epoxied. The completed assembly comprising the optical bench
(146) and the fiber is then placed into the optical bench adapter
(145A). In alternate embodiments, however, the optical bench (146)
remains in the cassette (200) while being epoxied to the assembly
end (12A).
[0047] As shown further in FIG. 9, the height (designated by "h")
of the cassette (200) may be designed to accommodate any given
number of spools (in this embodiment, two spools (108A & 108B))
consistent with the number of optical fibers desired in the
cassette assembly (202). The spool assembly hole (252) (also shown
in FIG. 10) provides access to fiber connectors (1 5A & 15B) by
automatic assembly equipment, if required. With further reference
to FIG. 9, the cassette (200) further comprises an electronic
module receiving area (220) for receiving an electronic module
(221). The electronic module (221) is retained securely by module
latches (223). The design of module latches (223) may be variable
depending on the physical design of electronic module (221). The
module assembly hole (225) located in the electronic module
receiving area (220) provides access to the electronic module (221)
by assembly equipment. The positioning of the electronic module
(221) in electronic module receiving area (220) facilitates
automatic connection of the fiber ends (16A & 16B) of the
optical fibers (10A & 100B), respectively, to the electronic
module (221). Once the spools (108A & 108B) and the electronic
module (221) are properly loaded in the cassette (200), the
cassette assembly (202) can be used to ship the electro-optical
device and/or for further processing of optical assemblies.
[0048] FIG. 10 shows a two-spool assembly that has been inserted
into a cassette and has had the ends of its optical fibers secured
to an electronic module, as described with reference to FIG. 9.
[0049] In another preferred embodiment of the present invention, as
shown in FIGS. 11, 12, and 13, a cassette (210) receives the
lengths of optical fiber (10A & 10B) directly, without use of
the separate spool(s) described herein. In the cassette assembly
(207) of FIG. 14, the cassette (210) and spool drum (257) are a
single, integral unit. The cassette (210) comprises an electronic
module receiving area (270) for receiving an electronic module
(221). The electronic module (221) may be inserted in the
electronic module receiving area (270) and retained by electronic
module latches (271), shown in FIG. 12. With reference to FIG. 11,
the cassette (210) also comprises a fiber receiving area (260) on
the underside of cassette (210), that receives the lengths of
optical fiber (10A & 10B).
[0050] Spool drum (257) includes one or more stepped concentric
rings around which individual fibers may be wound. As shown in FIG.
13, which shows the underside of cassette (210) spool drum (257)
includes two stepped rings (257A & 257B) for receiving optical
fibers (10A & 10B). Molded cuts in the rings allow the fibers
from inner rings to pass to the exterior of the largest ring.
Molded depressions in the floor of the cassette (210) allow the
fibers from the inner ring (257A) to pass under fibers wound the
larger diameter ring (257B). To ensure that the optical fibers (10A
& 10B) do not commingle and/or entangle, a retainer (253) is
snapped onto cassette (210) over spool drum (257). Retainer (235)
includes cutouts (295) to preclude crimping of the optical fibers
as they cross over fibers wound on larger rings. To eliminate
stress on the fiber that may occur during manipulation during
assembly, the cassette (210) includes draw areas (300A & 300B),
which allow for some excess fiber to be loosely held between fiber
end latches (256A & 256B) and fiber holder (260).
[0051] As shown in FIGS. 11 and 12, the fiber connectors (15A &
15B), into which one end of each length of optical fiber (10A &
10B) has been inserted, may be inserted into connector channels
(254A & 254B), respectively. The assembly ends (12A & 12B)
may be inserted into fiber end latches (256A & 256B) and
inserted into fiber end latch receiving areas (259A & 259B). An
electronic module cap (258) may be coupled to the cassette (210)
such that it covers all or part of electronic module (221). The
electronic module cap (258) may include a hole (262) to allow for
protrusion of power connector (261) of electronic module (221).
This design facilitates connection of the electronic module (221)
to a power supply.
[0052] As shown in FIG. 12, the placement of the connector channels
(254A & 254B) facilitates automatic connection of the fiber
connectors (15A & 15B) to assembly equipment, if required.
Further, the placement of the electronic module (221) in relative
location to fiber end latch receiving areas (259A & 259B), into
which fiber end latches (256A & 256B) have been inserted,
facilitates automatic connection of the assembly ends (12A &
12B) to the electronic module (221).
[0053] Thus, the system shown in FIGS. 11, 12 and 13 facilitates
shipment of fibers to a manufacturing area, retaining an electronic
module while presenting the fibers for assembly, and protecting the
finished assemblies during storage and shipment.
[0054] The specific preferred embodiments described herein, and all
of those embodiments that fall within the scope of the present
invention, may be used to facilitate automatic assembly of optical
devices. In particular, an optical fiber may be captured on a spool
of the present invention, as described with reference to FIGS. 1-7,
by automatic assembly equipment. Then, an electronic module and a
desired number of spools may be loaded into a cassette by automatic
assembly equipment. For example, with reference to FIG. 14A, an
electronic module (221), covered by electronic module cover (224),
and two spools (111A & 111B) have been loaded into cassette
(200) to form the cassette assembly (205). The assembly equipment
may, if required, automatically connect to the connectors (15A
& 15B) retained in the connector clips (131A & 131B)
through the spool assembly hole (252) (also shown in FIG. 10) in
the cassette (200). Alternatively, connectors (15A & 15B) are
precisely positioned in cassette (200) such that connection to a
light source/sensor can be made without use of assembly
equipment.
[0055] As further shown in FIG. 14A, the placement of the
electronic module (221) and the spools (111A & 111B) in
cassette (200) allows automatic assembly equipment to grip the
optical fibers (hidden here), by releasing ferrules (14A & 14B)
from the fiber end latches (141A & 141B) (as shown in FIG. 9)
by having the automatic assembly equipment exert pressure on their
respective tabs (143A & 143B), and to position the fiber ends
(16A & 16B) (as shown in FIG. 8) towards the electronic module
(221) for assembly. The tab (143A) of the spool (111A) can be
accessed through the tab access hole (231) in the underside of the
cassette (200), as shown in FIG. 9. The tab (143B) of spool (111B)
can be accessed through a tab access notch (153B) of spool (111A),
as shown in FIG. 14A. An alternative embodiment of a cassette
assembly (206), as shown in FIG. 15, allows direct access to the
fiber end latch (141B) of the spool (112B), thereby eliminating any
need for a tab access notch. FIG. 14B shows cassette assembly (301)
and includes electronic module (302) without a cover. Thus, bonding
area (303) of electronic module (302) is open and allows for an
assembly machine to grip the ferrules (304A & 304B) upon their
release, move them to the bonding area (303), and bond the fiber
ends (not shown) to the electronic module (302). Thus, both FIGS.
14B and 15 show embodiments in which fiber ends have been bonded to
electronic module (221). In alternative embodiments, the electronic
module (221) is held in a fixture, outside the cassette, during the
bonding process and placed back into cassette by automatic assembly
equipment upon completion.
[0056] As shown in FIG. 15, the design of the electronic module
receiving area (220) allows further processing as desired while
securely retaining both the electronic module (221) and the spools
(112A & 112B). The design also allows access to the internals
of the electronic module (221) either from above or from beneath
the electronic module (221), through the module assembly hole
(225), shown in FIG. 9. In some embodiments, an electronic module
cover (224), as shown in FIG. 15, is used to cover electronic
module (221). As also shown in FIG. 15, a power source can be
connected to electronic module (221) by automatic assembly
equipment via power connector (310). While these assembly steps are
described above as being performed automatically by assembly
equipment, one or more of these steps may be performed
manually.
[0057] A cassette assembly of the present invention can be used in
further handling and processing of the optical fibers and the
electronic module without need for any additional packaging or
carriers. Furthermore, the cassette assembly may serve as a
shipping container. The cassette assembly may be inserted into
packaging material or wrapped in shrink material for transporting
to the end user who may, in order to use the fibers and electronic
module in an optical assembly, remove the electronic module (221)
from the cassette (200), remove the spools (109A & 109B),
unclip the fiber connectors (15A & 15B) and remove the optical
fibers from the spools (109A & 109B) as shown, for example, in
FIG. 10.
[0058] Methods for carrying out the objects of the present
invention are described with reference to FIGS. 16A, 16B, 17A, 17B,
17C and 18. With reference to FIGS. 16A and 16B, a preferred
embodiment of a method for automatically assembling an
electro-optical device is illustrated. The electro-optical device
includes a cassette, one or more spools, and an electronic module.
In step 1601, one or more spools are loaded into a spool receiving
area of the cassette. The spools each capture a length of optical
fiber, which includes a first end and a second end. In step 1602,
the electronic module is loaded into an electronic module receiving
area of the cassette. In step 1603, the cassette is loaded into
assembly equipment. In step 1604, the first end of the fiber is
maintained for connection to a light source/sensor, with or without
use of automatic assembly equipment. In step 1605, the first end of
the fiber is connected to a light source/sensor and the electronic
module is connected to a power supply, if required. In step 1606,
the second end of the fiber is connected to the electronic module
by automatic assembly equipment. In some embodiments, this step is
performed while the electronic module is not retained in the
cassette (i.e., either before it is loaded into the cassette or it
is removed from the cassette for the connection procedure). In the
preferred embodiment, connecting the second end of the fiber to the
electronic module is accomplished by, first, bonding the second end
of the fiber to an electronic unit (using a very accurate and
precise connection) and, then, bonding the electronic unit to the
electronic module. In alternate embodiments, the electronic unit is
bonded to the electronic module and, then, the second end of the
fiber is bonded to the electronic unit. In step 1607, it is
determined whether the assembly includes additional
fibers/electronic units to be bonded to the electronic module. If
so, it is determined in step 1610 whether the fist ends are
maintained separately. If so, the process repeats from step 1604
and, if not, the process repeats from step 1606. If it is
determined that the assembly does not include additional
fibers/electronic units to be bonded to the electronic module, in
step 1608, any electronic and optical connections are detached and,
in step 1609, the cassette is removed from the assembly
equipment.
[0059] With reference to FIG. 17A, a preferred embodiment of a
method for automatically assembling an electro-optical device is
illustrated. The electro-optical device includes a cassette, one or
more lengths of optical fiber, and an electronic module. In step
1701, the lengths of optical fiber (each including a first end and
a second end) are loaded into an optical fiber receiving area of
the cassette and a cover is placed over the area to retain the
fiber. In step 1702, an electronic module is loaded into an
electronic module receiving area of the cassette. In step 1703, the
cassette is loaded into assembly equipment. In step 1704, the first
end of the fiber is maintained for connection to a light
source/sensor, with or without use of automatic assembly equipment.
In step 1705, the first end of the fiber is connected to a light
source/sensor and the electronic module is connected to a power
supply, if required. In step 1706, the second end is picked up by
assembly equipment and bonded to the electronic module. In one
embodiment the second end is positioned in the electronic module on
the electronic unit and bonded to the electronic unit installed in
the electronic module receiving area of the cassette. In step 1707,
it is determined whether the assembly includes additional fiber
ends to be bonded to the electronic module. If so, it is determined
in step 1710 whether the first ends are maintained separately. If
so, the process repeats from step 1704 or, if not, the process
repeats from step 1706. If it is determined that the assembly does
not include additional fiber ends to be bonded to the electronic
module, in step 1708, any electronic and optical connections are
detached and, in step 1709, the cassette is removed from the
equipment.
[0060] In certain embodiments, the cassette further includes a
drum, a fiber connector area and a module connection area. In this
embodiment, step 1701 includes, as shown in FIG. 17C, releasably
securing the first end in the fiber connector area in step 1710;
winding the length of optical fiber around the drum in step 1720;
and releasably securing the second end in the module connection
area in step 1730. In other embodiments, the lengths of optical
fiber are pre-loaded into the optical fiber receiving area of said
cassette and step 1701 is not necessary.
[0061] With reference to FIG. 18, a method for automatically
assembling a spool that transports of a length of optical fiber
(including a first end and a second end) is shown. The spool
includes a drum and a spool base, which may be separate pieces or
comprise a single unit. The spool base includes at least two fiber
end areas. In some embodiments, one fiber end area is a fiber
connector area (which includes a connector clip) and a second fiber
end area is a module connection area (which includes a fiber end
latch). In step 1801 of the method, the first end of the fiber is
maintained in one fiber end area (for example, is inserted into the
connector clip). In step 1802, the length of optical fiber is wound
around the drum by automatic assembly equipment. In step 1803, the
second end is maintained in a second fiber end area (for example,
is inserted into the fiber end latch).
[0062] While the invention has been described in detail and with
reference to specific embodiments thereof, it will be apparent to
one skilled in the art that various changes and modifications can
be made therein without departing from the spirit and scope
thereof. Thus, it is intended that the present invention cover the
modifications and variations of this invention provided they come
within the scope of the appended claims and their equivalents.
* * * * *