U.S. patent application number 16/265764 was filed with the patent office on 2019-06-06 for micro-endoscope and method of making same.
The applicant listed for this patent is Clear Image Technology, LLC. Invention is credited to Matthias Pfister, Michel Saint-Ghislain, Urban Schnell, Stefan Troller.
Application Number | 20190167072 16/265764 |
Document ID | / |
Family ID | 55347197 |
Filed Date | 2019-06-06 |
![](/patent/app/20190167072/US20190167072A1-20190606-D00000.png)
![](/patent/app/20190167072/US20190167072A1-20190606-D00001.png)
![](/patent/app/20190167072/US20190167072A1-20190606-D00002.png)
![](/patent/app/20190167072/US20190167072A1-20190606-D00003.png)
![](/patent/app/20190167072/US20190167072A1-20190606-D00004.png)
United States Patent
Application |
20190167072 |
Kind Code |
A1 |
Troller; Stefan ; et
al. |
June 6, 2019 |
MICRO-ENDOSCOPE AND METHOD OF MAKING SAME
Abstract
A micro-endoscope and method of making the same includes a
mounting housing, a camera module received within the mounting
housing, and an encapsulation material interposed between the
camera module and the mounting housing for fixedly mounting the
camera module within the mounting housing and/or inhibiting the
passage of light between the camera module and the mounting
housing. The micro-endoscope further includes a light guide having
the mounting housing received therein.
Inventors: |
Troller; Stefan; (Sissach,
CH) ; Schnell; Urban; (Munchenbuchsee, CH) ;
Pfister; Matthias; (Bern, CH) ; Saint-Ghislain;
Michel; (Dudingen, CH) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Clear Image Technology, LLC |
Elyria |
OH |
US |
|
|
Family ID: |
55347197 |
Appl. No.: |
16/265764 |
Filed: |
February 1, 2019 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
14826255 |
Aug 14, 2015 |
|
|
|
16265764 |
|
|
|
|
62039518 |
Aug 20, 2014 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61B 1/0011 20130101;
A61B 1/07 20130101; A61B 1/0607 20130101; A61B 1/051 20130101 |
International
Class: |
A61B 1/00 20060101
A61B001/00; A61B 1/07 20060101 A61B001/07; A61B 1/06 20060101
A61B001/06; A61B 1/05 20060101 A61B001/05 |
Claims
1. An endoscope, comprising: a camera module, with a camera that
receives an image; a scope shaft, having a front portion, where the
camera is mounted to receive the image from the front portion of
the scope shaft; a light guide, having a light receiving end
receiving light, and the light guide guiding the light along the
light guide, the light guide emitting the light at a light
transmitting end at the front portion of the scope shaft, the light
emitted at the light transmitting end illuminating an area of the
image at the front portion, the light guide having a first part
adjacent the light receiving end, that has a hollow and tapered
interior section, where the hollow part of the tapered interior
section narrows in size in a direction away from the camera to
define a conical chamber inside the light guide, and the light
guide terminating at the front portion emitting the light.
2. The endoscope as in claim 1, wherein the light guide at the
front portion forms a hollow cylindrical area which emits the light
in a cylindrical shape, completely around the camera.
3. The endoscope as in claim 2, wherein the light guide at the
light transmitting end surrounds the camera which is inside the
hollow inside section of the light guide.
4. The endoscope as in claim 2, further comprising a cylindrical
mounting tube, wherein the camera is within the cylindrical
mounting tube, and the cylindrical mounting tube is located within
the hollow inside section of the light guide.
5. The endoscope as in claim 4, wherein the light guide has a
second part that has a constant inner diameter, and the camera is
within the second part and is not within the first part.
6. The endoscope as in claim 1, wherein the light receiving end of
the light guide is solid and does not have a hollow portion
therein, and the hollow portion starts at a location spaced from
the light receiving end.
7. The endoscope as in claim 1, wherein the light guide has a
second part that has a constant inner diameter, that leads from the
first part that has a tapered interior section to the light
emitting end, and where the constant inner diameter part forms a
constant diameter hollow cylindrical area.
8. The endoscope as in claim 7, wherein an outer diameter of the
light guide has a tapered exterior diameter in an area of the first
part.
9. The endoscope as in claim 8, wherein the outer diameter of the
light guide has a constant exterior diameter in areas other than
the first part.
10. An endoscope comprising: an endoscope tube; a camera, located
in the endoscope tube and having an optical portion extending to
image an imaging area at a first end of the endoscope tube; a light
guide, having a first end which receives light, and having a second
end which is exposed to illuminate the imaging area at the first
end of the endoscope tube, lighting an area on the first end of the
endoscope tube, where the second end of the light guide surrounds
the camera and forms a hollow cylindrical area surrounding the
camera; the first end of the light guide which receives the light
being a filled, non-hollow, cylindrical area, the light guide
having a conical section adjacent the first end, wherein the
conical section of the light guide is hollow, and a diameter of the
hollow section of the light guide increases towards the second end,
to form the conical section, where the conical section leads to a
constant diameter section, which forms the hollow cylindrical area
that has a constant diameter, wherein the camera is located within
the hollow cylindrical area which has the constant diameter.
11. The endoscope as in claim 10, further comprising a cylindrical
mounting tube, and wherein the camera is mounted within the
cylindrical mounting tube, and wherein the cylindrical mounting
tube is located within the hollow interior section of the light
guide.
12. The endoscope as in claim 10, wherein an outer diameter of the
light guide tapers in exterior diameter in an area of the first
part, getting larger in exterior diameter as the hollow conical
section also increases in diameter.
13. The endoscope as in claim 11, further comprising encapsulation
material inside the cylindrical mounting tube, preventing light
from receiving reaching the camera.
14. A method of imaging using an endoscope, comprising: receiving
an image into a camera portion of a scope shaft of an endoscope,
the scope shaft, having a front portion, where the camera receives
the image from the front portion of the scope shaft; guiding
illuminating light for the camera on a light guide, having a light
receiving end receiving light, and the light guide guiding the
light along the light guide, the light guide emitting the light at
a light transmitting end at the front portion of the scope shaft,
the light emitted at the light transmitting end illuminating an
area of the image at the front portion, guiding the light through
the light guide through a first part adjacent the light receiving
end, that has a hollow and tapered interior section, where the
hollow part of the tapered interior section narrows in size in a
direction away from the camera to define a conical chamber inside
the light guide, the light exiting the light guide at the front
portion emitting the light.
15. The method as in claim 14, wherein the emitting from the light
guide at the front portion is in a hollow cylindrical area which
emits the light in a cylindrical shape, completely around the
camera.
16. The method as in claim 15, wherein the light guide at the light
transmitting end surrounds the camera which is inside the hollow
inside section of the light guide.
17. The method as in claim 15, further comprising mounting parts in
a cylindrical mounting tube, wherein the camera is within the
cylindrical mounting tube, and the cylindrical mounting tube is
located within the hollow inside section of the light guide.
18. The method as in claim 17, wherein the light guide has a second
part that has a constant inner diameter, and the mounting the
camera is within the second part and is not within the first
part.
19. The method as in claim 14, wherein the light receiving end of
the light guide is solid and does not have a hollow portion therein
and the solid portion receives the light, and the hollow portion
starts at a location spaced from the light receiving end and the
light is transmitted through the hollow portion.
Description
[0001] The present application claims priority to U.S. Prov. App.
Ser. No. 62/039,518, filed Aug. 20, 2014, the entity of which is
expressly incorporated herein by reference.
BACKGROUND
[0002] The present disclosure generally relates to medical devices,
and more particularly relates to a micro-endoscope and a method of
making the same. Micro-endoscopes are a type of endoscope having a
very small cross-sectional dimension. This can present unique
manufacturing challenges for the micro-endoscope. By way of
example, a micro-endoscope can have an outside diameter that is
less than about 4.0 mm. This small size inhibits easy manufacture
of the micro-endoscope and makes it difficult to position an image
capturing device, such as a camera, near the distal end of the
micro-endoscope.
[0003] In one known micro-endoscope, a camera module is painted
with a black paint and installed within an optical light guide near
the distal end of the micro-endoscope. In particular, lateral sides
of the camera module are painted with a thin coat of black paint
and the camera module is fit via an interference fit within the
light guide. Then, both the camera module and the light guide are
received with in a steel outer sheath.
[0004] There are a number of potential drawbacks with this
arrangement. For example, the dimensions of the camera module alone
and/or the camera module with the black paint thereon can be too
inconsistent resulting in problems when inserting the camera in the
light guide tube. Also, the attachment of a ribbon cable to the
back of the camera module can be susceptible to failure due to the
connection being maintained by only relatively weak solder
connections. Additionally, the micro-endoscope can suffer from
decreased optical output due to stray light passing by the camera
module. Further, the black paint can sometimes interfere with the
optics of the camera module and it is possible for parasitic paint
particles to develop due to local detachment of the black
paint.
SUMMARY
[0005] According to one aspect, a micro-endoscope device for
insertion into a body includes a camera module received within a
mounting tube and an encapsulation material interposed between the
camera module and the mounting tube. The micro-endoscope device
further includes a light guide tube annularly disposed around the
mounting tube for transmitting light axially past the camera module
and the mounting tube.
[0006] According to another aspect, a micro-endoscope with an
encapsulated camera includes a mounting housing, a camera module
received within the mounting housing, and an encapsulation material
interposed between the camera module and the mounting housing for
fixedly mounting the camera module within the mounting housing
and/or inhibiting the passage of light between the camera module
and the mounting housing. The micro-endoscope further includes a
light guide having the mounting housing received therein.
[0007] According to a further aspect, a method of making a
micro-endoscope includes inserting a camera module into a mounting
housing and at least partially encapsulating the camera module with
an encapsulation material interposed between the camera module and
the mounting housing for fixedly mounting the camera module within
the mounting housing and/or inhibiting the passage of light between
the camera module and the mounting housing. The method further
includes inserting the mounting housing into a light guide
tube.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a partial perspective view of a micro-endoscope
with an encapsulated camera according to an exemplary
embodiment.
[0009] FIG. 2 is an axial cross-section of the micro-endoscope of
FIG. 1 taken along the line 2-2 of FIG. 1.
[0010] FIG. 3 is a front elevation view of the micro-endoscope of
FIG. 1.
[0011] FIG. 4 is an isolated perspective view of a mounting tube of
the micro-endoscope of FIG. 1.
[0012] FIG. 5 is an isolated perspective view of a light guide tube
of the micro-endoscope of FIG. 1.
[0013] FIG. 6 is an isolated perspective view of a light guide tube
according to an alternate exemplary embodiment.
[0014] FIG. 7 is a perspective view similar to FIG. 6 but showing a
cone complementarily received within the light guide tube according
to a further alternate exemplary embodiment.
[0015] FIG. 8 is a schematic cross-section view similar to FIG. 2
but shown schematically and shown including a disc or puck shaped
member according to an exemplary embodiment.
[0016] FIG. 9 is a process flow diagram illustrating a method of
making a micro-endoscope according to an exemplary embodiment.
[0017] FIG. 10 is a further process flow diagram further
illustrating a method of making a micro-endoscope according to an
exemplary embodiment.
DETAILED DESCRIPTION
[0018] Referring now to the drawings wherein the showings are for
purposes of illustrating one or more exemplary embodiments and not
for purposes of limiting the same, FIG. 1 illustrates a
micro-device adapted for insertion into a body (e.g., a human body)
and generally designated by reference 10. As also described in more
detail herein, the micro-device 10 is a micro-endoscope with an
encapsulated camera in the illustrated embodiment. The
micro-endoscope 10 can be part of an endoscope system (e.g., an
arthroscopic system or some other scope system) that additionally
includes a reusable hand piece, a display/console, appropriate
software and image enhancement algorithms, etc. (none of foregoing
are shown in the illustrated embodiment). In one configuration, the
micro-endoscope 10 can be provided in a package for use as a
single-use item (i.e., the micro-endoscope 10 can be a disposable
endoscope designed for single use). By way of example, the outside
diameter of the illustrated micro-endoscope can be less than 3 mm,
preferably less than 2.5 mm, and more preferably approximately 2.2
mm, though other dimensions could be used. In the illustrated
embodiment, the cross-section of the micro-endoscope is circular or
round but this is not required (e.g., the micro-endoscope 10 could
have a oval cross-section, rectangular cross-section, octagonal
cross-section, etc.).
[0019] With additional reference to FIGS. 2 and 3, the
micro-endoscope 10 can include a mounting housing 12 and a camera
module 14 (schematically illustrated) received within the mounting
housing 12. As shown in the illustrated embodiment, the mounting
housing 12 is in the form of, and is alternately referred to herein
as, a mounting tube. By way of example, the camera module 14 can be
a micro-CMOS camera module having optics 16 (e.g., camera lens)
disposed on a forward facing imaging surface 14a of the camera
module 14. A ribbon cable 18 (e.g., a bundle of wires carrying
power and data) can be operatively connected to the camera module
14 at a rearward facing surface 14b of the camera module 14. For
example, the ribbon cable 18 can be soldered to connections (not
shown) provided on the rearward facing surface 14b. As used herein,
the directional terms forward and rearward are relative to a distal
end 10a of the micro-endoscope 10 such that forward facing is in a
direction toward the distal end 10a and rearward facing is in a
direction facing away from the distal end 10a.
[0020] The micro-endoscope 10 further includes an encapsulation
material 20 and a light guide 22. The encapsulation material 20 is
interposed between the camera module 14 and the mounting tube 12
for fixedly mounting the camera module 14 within the mounting tube
12 and/or inhibiting the passage of light between the camera module
14 and the mounting housing 12. The light guide 22 has the mounting
housing 12 received or accommodated therein with the camera module
14 received within the mounting tube 12. In the illustrated
embodiment, the light guide 22 is in the form of, and alternately
referred to herein as, a light guide tube. The light guide tube 22
is annularly disposed around the mounting tube 12 for transmitting
light axially past the camera module 14 and the mounting tube 12.
In particular, glue or some other adhesive (not shown) can fixedly
secure the mounting tube 12 and the light guide 22 together. In one
embodiment, the light guide 22 can be formed of a light
transmissive plastic.
[0021] Advantageously, the encapsulation material 20 and the
inclusion of the mounting tube 12 overcome many of the drawbacks of
known micro-endoscopes. In particular, providing the camera module
14 in an encapsulated state within the mounting tube 12 allows for
good installation of the mounting tube 12 into the light guide 22.
More specifically, the outer dimensions of the mounting tube 12 can
be more precisely controlled than those of the camera module and/or
the camera module with black paint added thereon. This enables a
repeatable interference fit between the mounting tube 12 and the
guide tube 22 that often failed in the known arrangement.
Additionally, the use of the encapsulation material 20 instead of
paint enables filling of any gaps between the camera module 14 and
the surrounding mounting tube 12 and light guide 22. In contrast
with the known arrangement that used paint, the use of the
encapsulation material 20 better inhibits or reduces stray light
from passing between the light and the camera (i.e., instead, light
can only pass physically through the light guide). Further,
adherence of the encapsulation material 20 is much greater than
paint so the problem with parasitic paint particles is greatly
reduced or eliminated.
[0022] The camera module 14 of the illustrated embodiment includes
the forward facing imaging surface 14a and lateral walls 14c
orthogonally extending rearwardly from the forward facing imaging
surface 14a. The encapsulation material 20 is interposed between
the lateral walls 14c and an inner radial surface 12a of the
mounting tube 12. More particularly, the camera module 14 of the
illustrated embodiment is generally cuboid shaped, though this is
not required, and includes the rearward facing surface 14b opposite
and spaced apart from the forward facing imaging surface 14a with
the lateral walls 14c extending therebetween. The camera module 14
is arranged so as to form, at least in part, the distal end 10a of
the micro-endoscope 10.
[0023] As shown, the encapsulation material 20 fully surrounds the
camera module 14 and fills any gap between the camera module 14 and
an interior (i.e., the inner radial surface 12a) of the mounting
tube 12. The rearward facing surface 14b is axially spaced apart
from a rear axial end 12b of the mounting tube 12 to define a first
rearward area RA1 axially rearwardly of the rearward facing surface
14b. The encapsulation material 20 also fills the area RA2 so the
encapsulation material 20 is disposed axially between the rearward
facing surface 14b of the camera module 14 and the rear axial end
12b of the mounting tube 12 to fully encapsulate the rearward
facing surface 14b of the camera module 14. Additionally, the
encapsulation material 20 in this area secures the connection of
the ribbon cable 18 to the camera module 14.
[0024] More specifically, the ribbon cable 18 is electrically
connected to the camera module 14 (e.g., via soldered connections,
not shown). In an known micro-endoscope, the soldered connections
between a ribbon cable and the associated camera module are
susceptible to failure. In the exemplary embodiment described and
illustrated herein, encapsulation via the encapsulation material 20
enhances the connection of the ribbon cable 18 to the camera module
14 to inhibit inadvertent breakage or failure of the soldered
connection between the ribbon cable 18 and the camera module 14. In
an exemplary embodiment, the encapsulation material both fixedly
mounts the camera module 14 within the mounting tube 12 and
inhibits light transmission between the camera module 14 and the
mounting tube 12. This arrangement also provides extra rigidity to
the ribbon cable 18 by causing any force transmitted at that
location to be imparted into the encapsulation material 20 instead
of being handled by soldered connections between the ribbon cable
18 and the camera module 14. This provides increased mechanical
robustness for the micro-endoscope 10 because strain relief for the
ribbon cable 18 is provided.
[0025] In one exemplary embodiment, the encapsulation material 20
can be an adhesive that is optically black. Additionally, the
encapsulation material 20 can be bio-compatible. For example, the
encapsulation material 20 can be formulated to meet USP Class VI
and ISO 10993 standards for use in the body. Additionally, or in
the alternative, the encapsulation material 20 can be formulated
such that it is stable against a wide variety of chemicals normally
found in medical settings. In one specific exemplary embodiment,
the encapsulation material 20 can be formed as a mixture of a two
component epoxy adhesive and a colorant. One such exemplary two
component epoxy has a specific gravity of about 1.16, a viscosity
of about 30 Pas at 25 degrees Celsius, a cure time of about 5 hours
to reach more than 10 Mpa of lap shear strength and about 23 hours
to reach more than 1 MPa of lap shear strength. The epoxy can be
transparent/color free and solvent free. A specific exemplary two
component epoxy is sold under the trade name ARALDITE.RTM. CRYSTAL
by Huntsman Advanced Materials (of Switzerland). The colorant can
be a concentrated black colorant or pigment. A specific exemplary
colorant is sold under the trade name EPO-TEK #11 by Epoxy
Technology, Inc. (of Billerica, Mass.). An exemplary mixture ratio
is 5-7% by weight of the colorant is added to the two-part epoxy.
Alternately, another exemplary encapsulation material is an
optically black adhesive (no colorant needed). a specific exemplary
such adhesive is sold under the trade name EPO-TEK 320-3M by Epoxy
Technology, Inc. (of Billerica, Mass.).
[0026] In the same or another exemplary embodiment, the mounting
tube 12 can be selected from a thin material (e.g., a metallic
material) that is not light transmissive and/or has a high
reflectivity across the visible spectrum. For example, the mounting
tube 12 can be formed from a material that has a light reflectivity
greater than about 80%. Additionally, or in the alternative, the
mounting tube can be selected from a material that has high
ductility. By way of a specific example, the mounting tube 12 can
be formed of a very thin (e.g., about 59 .mu.m) aluminum or an
aluminum alloy for preventing light transmission therethrough and
providing high reflectivity across the visible spectrum (e.g.,
greater than 80%) to increase light transmission through the light
guide tube 22.
[0027] As best shown in FIG. 2, a rearward axial end 22a of the
light guide tube 22 can be axially spaced apart from the rear axial
end 12b of the mounting tube 12 to form a second rearward area RA2.
Accordingly, the rearward axial end 22a of light guide tube 22 is
also axially spaced apart from the rearward facing surface 14b of
the camera module 14. An adhesive 38 can fill the area RA2 radially
within the light guide tube 22 adjacent or at the rearward axial
end 22a, and axially rearward of the mounting tube 12 and the
encapsulation material 20 disposed therein. The adhesive 38 can be
a clear or light transmissive adhesive, such as an optically clear
epoxy. In one exemplary embodiment, the adhesive 38 can use the
same epoxy used to mix with a colorant to form the encapsulation
material described above. As a specific example, the adhesive 38
could be a two component epoxy such as the one sold under the trade
name ARALDITE.RTM. CRYSTAL by Huntsman Advanced Materials (of
Switzerland). Alternatively, the adhesive 38 could be a reflective
epoxy. For example, a reflective epoxy can be optically clear but
with the inclusion of light scattering particles, such as metallic
flakes. In one exemplary example, the light scattering particles
can be aluminum or formed form another material with a reflective
coating thereon.
[0028] As also shown and mentioned above, the forward facing
imaging surface 14a of the camera module 14 and a forward axial end
12c of the mounting tube form the distal end 10a of the
micro-endoscope 10. Additionally, the light guide tube 22 has a
forward axial end 22b axially aligned with the forward facing
imaging surface 14a of the camera module 14 and the forward axial
end 12c of the mounting tube 12. Thus, the light guide tube 22, and
particularly the forward axial end 22b thereof, also forms the
distal end 10a of the micro-endoscope. As shown in the illustrated
embodiment, the forward axial end 22b of the light guide 22 can
include a chamfered edge 30 (see FIG. 1) for controlling light
distribution as is known and understood by those skilled in the
art. In one embodiment, the chamfered edge 30 is formed using a
hand miller with a curved attachment and/or has a convex arc
between 60 and 90 degrees.
[0029] The micro-endoscope 10 can additionally include a tubular
scope shaft 32 annularly disposed around the light guide 22. In
particular, a forward axial end 32a of the tubular scope shaft 32
can be axially spaced apart rearwardly from the forward facing
imaging surface 14a of the camera module 14 and from the forward
axial end 12c of the mounting tube 12. By way of example, the
tubular scope shaft 32 can be formed of a metal, such as stainless
steel. Still further, the micro-endoscope 10 can include an optical
fiber 34 abutting the rearward axial end 22a of the light guide
tube 22 and housed within the tubular scope shaft 32. The adhesive
38 can optionally fixedly secure the optical fiber 34 to the light
guide 22.
[0030] With additional reference to FIG. 4, the mounting tube 12
can include an axial slit 26 for increasing dimensional tolerance
of the camera module 14. In particular, the axial slit 26 can
provide some dimensional flexibility for the mounting tube 12 thus
enabling adjustment of its diameter. More specifically, the axial
slit 26 acts as a tolerance compensator (i.e., spring effect) and
ensures a good fitting of the camera module 14. Accordingly, the
mounting tube 12 can better accommodate camera modules that are
dimensionally out of spec so insertion into the light guide tube 22
and the tubular scope shaft 32 is more repeatable, with camera
positioning being more consistent.
[0031] With reference to FIG. 5, the light guide tube 22 includes
or defines a notch 36 for accommodating the ribbon cable 18. In
particular, in the illustrated embodiment, the ribbon cable 18
extends from the rearward facing surface 14b of the camera module
14 and then extends axially at or near an axial centerline of the
micro-endoscope 10 until reaching about the rearward axial end 22a
of the light guide tube 22. At this location, the ribbon cable 18
makes a ninety degree turn and passes through the notch 36 before
entering an axial recess 32b defined radially into an
circumferential surface of the optical fiber 34 and defined along
an axial extent of the optical fiber 34.
[0032] With reference to FIG. 6, another light guide tube 22' is
shown according to an alternate embodiment. The light guide tube
22' of FIG. 6 can replace the light guide tube 22 in the embodiment
shown in FIGS. 1-5, though the tubular shaft 32 would be modified
to accommodate the non-linear shape of the light guide 22'.
Advantageously, the rearward axial end 22a' of the light guide tube
22' is closed and has a tapered interior that narrows in a rearward
direction away from the camera module 14 to define a conical
chamber 40. This allows less clear adhesive 38 to be used and
increases the amount of light transferred through the light guide
tube 22'. In all other aspects, the light guide tube 22' can be
used and arranged in the same manner as the light guide tube
22.
[0033] With additional reference to FIG. 7, the light guide 22' can
optionally be used with a cone 42 received complementarily within
the conical chamber 40 for absorbing heat coming from the camera
module 14 (e.g., via heat transfer through the encapsulation
material 20 and/or through the mounting tube 12) and/or for
reflecting light away from the camera module 14 and/or the
encapsulation material 20 surrounding the camera module 14. In one
embodiment, the cone 42 is formed of a material (e.g., a metal,
such as aluminum) having good heat conducting properties. In
addition, or in the alternative, the cone 42 can be formed from, or
coated with, a material having high light reflectivity (e.g.,
greater than about 80%). In one embodiment, the cone 42 is formed
as a metallic object, optionally with a reflective coating, so as
to absorb heat from the camera module 14 and to reflect light
radially away from the camera module 14. When absorbing heat, the
temperature at the distal end 10a of the micro-endoscope 10 is
reduced. When the cone 42 is included within the light guide 22',
the adhesive 38 can be accommodated within the light guide 22'
axially rearward of the cone 42 in area RA3. Though not shown, a
light reflecting and/or heat absorbing member (e.g., disc or puck
shaped member 44 of FIG. 8) could be used in the embodiment shown
in FIG. 2 that functions the same or similar to the cone 42 of FIG.
7. For example, with reference to FIG. 8, disc or puck shaped
member 44 could be axially adjacent the encapsulation material 20
in the area RA2 while leaving an axial rearward portion of the area
RA2 available for receiving the adhesive 38. The disc or puck
shaped member 44 could absorb heat coming from the camera module 14
(e.g., via heat transfer through the encapsulation material 20
and/or through the mounting tube 12) and/or reflect light away from
the camera module 14 and/or the encapsulation material 20
surrounding the camera module 14.
[0034] Instead of the cone 42, a high thermal conductivity material
(e.g., a thermal gel) could be used in the light guide 22' or,
instead of the disc or puck shaped member 44, a high thermal
conductivity material could be used in the light guide 22 in FIG.
2. The high thermal conductivity material could also be used to
replace some amount of the adhesive 38 in the light guide 22' of
FIG. 7 or in the light guide 22 of FIG. 2. The high thermal
conductivity material could be used to absorb heat from the camera
module 14 (e.g., in the same manner that the cone 42 absorbs heat).
In one embodiment, the high thermal conductivity material could be
a gel or semi-gel that dissipates heat from the camera module 14.
The high thermal conductivity material could function in the same
manner as the cone 42 or the member 44 to absorb heat and reduce
the temperature at the distal end 10a of the micro-endoscope 10. In
an exemplary embodiment, the high thermal conductivity material has
a thermal conductivity that is about 10 times greater than a light
polycarbonate, such as for example a thermal conductivity of about
1 W/m-K. The adhesive 38 would be added axially rearward of the
high thermal conductivity material to seal in the material within
the light guide 22 or 22'. For example, referring to FIG. 8, the
high thermal conductivity material could replace the member 44 and
would be sealed within the light guide 22 by the adhesive 38.
[0035] With reference now to FIG. 9, a method of making a
micro-endoscope will be described. In particular, the method of
FIG. 9 will be described in association with the micro-endoscopes
discussed hereinabove, though this is not required and it is to be
appreciated that the method can be used with other
micro-endoscopes. In the method, at S100, the camera module 14 is
inserted into the mounting housing 12. At S102, the camera module
14 is at least partially encapsulated with the encapsulation
material 20 interposed between the camera module 14 and the
mounting housing 12 for fixedly mounting the camera module 14
within the mounting housing 12 and/or inhibiting the passage of
light between the camera module 14 and the mounting housing 12.
[0036] In one embodiment, the encapsulation material 20 is inserted
inside the mounting housing 12, such as via an applicator with a
fine tip. Optionally, heat can be applied, such as by a heat gun,
to decrease the viscosity of the encapsulation material 20 and
ensure that the encapsulation material 20 fills in all gaps around
the camera module 14. With the camera module 14 fully installed or
inserted into the mounting housing 12, further encapsulation
material 20 can be injected into or added to the mounting housing
12 so that the rear facing surface 14b of the camera module 14 is
fully encapsulated and the ribbon cable 18 is fully encapsulated
particularly where the ribbon cable 18 connects to the camera
module 14. As already mentioned herein, the encapsulation material
20 can be selected so that the material functions to both fix the
camera module 14 within the mounting housing 12 and blocks the
transmission of light thereby so that no light can pass between the
camera module 14 and the inner radial surface 12a of the mounting
housing 12.
[0037] Next, at S104, the mounting housing 12, with the camera
module 14 already inserted therein, can be itself inserted into the
light guide 22 (or into the light guide 22'). This can include the
application of a glue or other adhesive to fix the mounting housing
to the light guide 22 or 22'. The method could end after S104 such
as in the case where the sub-assembly including the mounting
housing 12, the camera module 14 and the light guide 22 is to be
shipped remotely before being fully assembled into the
micro-endoscope 10.
[0038] In the alternative, with additional reference to FIG. 10,
the method can continue at 106. In particular, after the mounting
housing 12 is inserted into the light guide 22 22' in S104, the
adhesive 38 can be added at S106 within the light guide 22 or 22'
rearward of the camera module 14, mounting housing 12, and
encapsulation material 20. Then, at S108, the light guide 22 or 22'
can be inserted into the tubular scope shaft 32 and, at S110, the
optical fiber 34 can be arranged within the tubular scope shaft 32
in abutting contact with the rearward axial end 22a of the light
guide 22 (or light guide 22').
[0039] Before or after steps S106, S108 and S110, the light guide
22 (or light guide 22'), and particularly the forward axial end 22b
thereof, can be chamfered, as is known and understood by those
skilled in the art, so as to provide chamfered edge 30 (FIG. 1) on
the light guide for controlling light distribution. As indicated
above, in one embodiment, the chamfered edge 30 is formed using a
hand miller with a curved attachment and/or has a convex arc
between 60 and 90 degrees. The chamfering step can include the
removal of any excess encapsulation material 20 from the camera
module. In addition, or in the alternative, cleaning of the camera
module 14 can occur at any time (and multiple times) before or
between steps S100-S110. In one embodiment, the camera module 14 is
cleaned using isopropyl alcohol and a cotton swab to remove any
residues (e.g., encapsulation material 20 flowing onto the camera
module 14).
[0040] Optionally, a light reflecting and/or heat absorbing member,
such as cone 42 or member 44 can be installed in the appropriate
light guide 22' or 22 prior to the adhesive 38 being added.
Alternatively, a high thermal conductivity material could be used
instead of the cone or member 44.
[0041] It will be appreciated that various of the above-disclosed
and other features and functions, or alternatives or varieties
thereof, may be desirably combined into many other different
systems or applications. Also that various presently unforeseen or
unanticipated alternatives, modifications, variations or
improvements therein may be subsequently made by those skilled in
the art which are also intended to be encompassed by the following
claims.
* * * * *