Side view endoscope

A side view type endoscope includes a front end body having a view window on the side surface thereof, a detachable front end cover which covers the front end body, an opening provided on the side surface of the front end cover, through which the view window is exposed to the exterior, air and/or water supply passages which supply cleaning air and/or water, and a nozzle connected to the air and/or water supply passages to selectively inject air or water toward the view window, wherein the air and/or water supply passages are provided on said front end body and the nozzle is provided on the front end cover.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to an endoscope, and more precisely to a side 
view type endoscope having a view window provided on a side surface of a 
front end body thereof. 
2. Description of Related Art 
There is a known side view type endoscope which is provided, on a side 
surface of a front end body thereof, with a view window and an 
illumination window provided adjacent to the view window. The outer 
surface of the portion of the front end body other than the view window 
and the illumination window is entirely covered by a front end cover. The 
front end body is provided with a nozzle secured thereto, whose front 
injection port opens toward the outer surface of the view window. The 
nozzle selectively injects air or water onto the surface of the view 
window through the injection port to clean the view window. 
In the known side view type endoscope as mentioned above, since the nozzle 
is permanently secured to the front end body, it is difficult or 
troublesome to clean the nozzle and air and water supply passages 
connected to the nozzle. 
An answer to this problem is to provide a nozzle which can be detachably 
attached to the front end body. Heretofore, various front view type 
endoscopes provided with detachable nozzles have been proposed. However, 
it is difficult to provide such a nozzle to a conventional side view type 
endoscope, since the nozzle is disposed on the side surface of the front 
end body. 
SUMMARY OF THE INVENTION 
The primary object of the present invention is to provide a side view type 
endoscope in which the interior of the nozzle and the air and water supply 
passages connected to the nozzle can be easily cleaned. 
To achieve the object mentioned above, according to the present invention, 
there is provided a side view type endoscope including a front end body 
having a view window on the side surface thereof, a detachable front end 
cover which covers the front end body, an opening provided on the side 
surface of the front end cover, through which the view window is exposed 
to the exterior, air and/or water supply passages which supply cleaning 
air and/or water, and a nozzle connected to the air and/or water supply 
passages to selectively inject air or water toward the view window, 
wherein the air and/or water supply passages are provided on the front end 
body and the nozzle is provided on said front end cover. 
Preferably, the side view type endoscope further comprises an engaging 
projection provided on the end cover, and an engaging recess provided on 
the end body, in which the engaging projection is fitted to prevent the 
front end cover from being accidentally disengaged from the front end 
body. 
The engaging projection can be provided with a connecting hole which 
constitutes a part of the nozzle, to which the air supply passage and the 
water supply passage are connected when the engaging projection is fitted 
in the engaging recess. 
The front end cover and said front end body can be provided with a second 
engaging projection and a second engaging recess in which the second 
engaging projection is fitted to prevent the front end cover from being 
accidentally detached from the front end body. 
In an embodiment, the first and second engaging projections are made of a 
resilient material of which the front end cover is made. 
The front end cover can be comprised of an elastically deformable body 
member, and a deformation restricting member whose elasticity is lesser 
than that of the body member, and wherein at least the second engaging 
projection is supported by the deformation restricting member. 
Preferably, the air supply passage and said water supply passage are formed 
adjacent and parallel within the front end body, the connecting hole 
provided in the engaging projection comprises a connecting groove which 
extends in a direction perpendicular to the longitudinal direction of the 
front end body, so that the air supply passage and the water supply 
passage open in to the connecting groove. 
The connecting hole can be provided with a discharge hole which is 
connected at one end thereof to the connecting groove and which opens at 
the other end toward the view window. 
According to another aspect of the invention, there is provided a side view 
type endoscope includes a front end body having a recess which forms an 
end surface perpendicular to an axis of the front end body, air and/or 
water supply passages which supply cleaning air and/or water, an open end 
of the air and/or water supply passages being opened at the end surface of 
the front end body, a detachable front end cover which covers the front 
end body, a nozzle provided on the front end cover, the nozzle being 
connected to the open end of the air and/or water supply passages. 
The present disclosure relates to subject matter contained in Japanese 
patent application Nos. 6-112398 (filed on May 26, 1994) and 6-112399 
(filed on May 26, 1994) which are expressly incorporated herein by 
reference in their entireties.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
An improved side view type endoscope according to a first embodiment of the 
present invention, free from the above-mentioned drawbacks will be 
discussed below with reference to FIGS. 1 through 5. 
The front end body 1 of the side view type endoscope is made of a generally 
circular metal rod having a partially flat surface portion 1b, as shown in 
FIGS. 1 and 3. The front end body 1 is provided on the flat surface 
portion 1b thereof with a view window 4, an illumination window 5, and a 
treatment tool insertion opening 6 (FIG. 2). The flat surface portion is 
defined by the remaining circular rod portion (extruding portion) 1a which 
is located behind (right side of the flat surface portion 1b in FIG. 1) 
the flat surface portion 1b. The front end body 1 including the extruding 
portion 1a is fitted in a front opening 2 of a flexible endoscope for 
attaching the front end body 1 to the endoscope. A flexible rubber tube 3 
seals the outer periphery of the front opening 2 of the endoscope, as 
shown in FIG. 1. 
As can be seen in FIG. 1, the illumination window 5 is provided with an 
orientation lens 13 made of a concave lens fitted and secured therein for 
diffusing the illumination light incident thereto. A bundle of optical 
fibers (optical fiber bundle) 14 is provided below the orientation lens 13 
for transmitting illumination light to the orientation lens 13. The 
emission end of the fiber bundle 14 is opposed to the orientation lens 13. 
The view window 4 is provided with a cover lens 15 for a viewing optical 
system secured thereto. The front end body 1 includes a prism 16 located 
below the cover lens 15 to deflect the optical axis of the viewing optical 
system by 90 degrees, an objective lens 18 and a solid state image pickup 
device 19. The objective lens 18 and the solid state image pickup device 
19 are provided in a lens barrel 17. The solid state image pickup device 
19 is comprised of, for example, a charge coupled device (CCD) and has a 
light receiving surface located at an image forming position in which an 
object image is formed by the objective lens 18. The CCD 19 is connected 
to an operating portion (not shown) through a signal cable 20 which 
extends rearward within the endoscope. 
The front end body 1 is provided with a recessed groove 22 having a flat 
bottom surface, located behind the cover lens 15, as shown in FIGS. 1, 2 
and 3. The recessed groove 22 has a lateral width substantially identical 
to the width of the flat surface portion 1b of the front end body 1 and a 
predetermined length in the longitudinal direction of the endoscope. 
The recessed groove 22 is defined by a vertical rear end wall 22a which is 
provided with an air supply passage 25 and a water supply passage 26. The 
air supply passage 25 and the water supply passage 26, both of which open 
into the recessed groove 22 are connected to an air supply pipe 23 and a 
water supply pipe 24, respectively. 
The portion of the front end body 1 other than the view window 4, the 
illumination window 5, and the treatment tool insertion opening 6 is 
entirely covered by a front end cover 30 which is made of a water-tight 
resilient material, such as resilient fluororubber. The front end cover 30 
is in the form of a cap having a closed front end and an open rear end. 
The front end cover 30 is provided with an opening 31 corresponding to the 
view window 4, the illumination window 5, and the treatment tool insertion 
opening 6. 
The front end cover (end cap) 30 is attached to the front end of the front 
end body 1, while expanding the diameter of the front end cover 30. The 
front end cover 30 is provided on the rear end thereof with a first 
engaging projection in the form of an inner peripheral flange 32 which 
slightly projects inwardly. The inner peripheral flange 32 is fitted in a 
peripheral first engaging recess or groove 7 formed on the extruding 
portion 1a of the front end body 1 when the front end cover 30 is attached 
to the front end of the front end body 1, so as to prevent the accidental 
detachment of the front end cover 30 from the front end body 1. The end 
cap 30 is provided on the front end thereof with a hole 33 having a spot 
facing in which a machine screw 8 is inserted to be screwed in a 
corresponding threaded hole of the front end body 1 to firmly attach the 
end cap 30 to the front end body 1. 
The end cap 30 is also provided with a projection 35 providing a second 
engaging projection corresponding to the recessed groove 22 of the front 
end body 1 which provides a second engaging recess, so that when the end 
cap 30 is attached to the front end body 1, the projection 35 is 
airtightly fitted in the recessed groove 22. The projection 35 has a flat 
bottom surface (inner surface) that faces inwardly. Consequently, when the 
engaging projection 35 is fitted in the engaging recessed groove 22, the 
flat bottom surface of the projection 35 comes into contact with the 
bottom surface of the recessed groove 22, thereby, preventing the relative 
rotation of the end cap 30 and the front end body 1 from taking place. 
The front end cover 30 is provided with an elongated connecting groove 36 
formed in the latter half of the projection 35 and extending in a 
direction perpendicular to the longitudinal axis of the endoscope. The air 
supply passage 25 and water supply passage 26 are formed adjacent and 
parallel and open into a discharge passage 42 of the connecting groove 36 
when the front end cover 30 is attached to the front end body 1. 
A nozzle 37 which is directly connected to the connecting groove 36 opens 
into the front wall of the projection 35 of the front end cover 30. The 
nozzle 37 is located in the vicinity of the cover lens 15 so that when the 
front end cover 30 is attached to the front end body 1, the front end of 
the nozzle 37 faces the outer surface of the cover lens 15. Consequently, 
air or water fed through the air supply pipe 23 or the water supply pipe 
24 is injected from the nozzle 37 through the connecting groove 36 onto 
the outer surface of the cover lens 15. 
A remote-control type treatment tool 9 is provided within the treatment 
tool inserting opening 6 to which a front end of a treatment tool 
insertion channel 11 (FIG. 3) formed in the front end body 1 is connected. 
As shown in FIG. 3, an operation wire 12 is provided within the front end 
cover 30 so as to swing the treatment tool 9 by a remote control (not 
shown) during treatment. 
In using the endoscope as constructed above, the cleaned front end cover 
(end cap) 30 is attached to the cleaned front end body 1. Upon attachment, 
the inner peripheral flange 32 and the projection 35, etc., are 
elastically deformed (expanded) due to the elasticity of the front end 
cover 30. When the front end cover 30 is securely attached to the front 
end body 1, the inner peripheral flange 32 and the projection 35, etc., 
are returned to their initial state due to the elastic restoring force, so 
that the inner peripheral flange 32 and the projection 35 are firmly 
engaged in the peripheral groove 7 and the recessed groove 22, 
respectively. Thereafter, the machine screw 8 is inserted in the hole 33 
of the front end cover 30 and screwed in the threaded hole of the front 
end body 1 to steadfastly secure the front end cover 30 to the front end 
body 1. 
In this state, the view window 4, the illumination window 5, and the 
treatment tool insertion opening 6 are exposed to the outside through the 
opening 31; the nozzle 37 faces the outer surface of the cover lens 15; 
and, the air supply passage 25 and the water supply passage 26 are 
connected to the connecting groove 36. 
To wash or clean the endoscope after use, the machine screw 8 is loosened 
and disengaged from the hole 33 the front end cover 30 is slid rearward 
with respect to the front end body 1 while expanding the rear end thereof. 
Consequently, the front end cover 30 is detached from the front end body 
1. Thereafter, a cleaning brush 40 is inserted into the air supply passage 
25 or the water supply passage 26, that is exposed by removing the front 
end cover 30 to brush and clean the air supply pipe 23 or the water supply 
pipe 24. as can be seen in FIG. 5. Furthermore, the nozzle 37 which is 
formed in the removed front end cover 30 can be easily cleaned from the 
front end side or rear end side thereof. 
As can be understood from the above discussion, according to the present 
invention, the nozzle 37 which is adapted to inject a cleaning fluid 
toward the outer surface of the view window 4 is formed in the front end 
cover 30 which is detachably attached to the front end body 1 of the 
endoscope, the nozzle formed in the front end cover 30 and the fluid 
supply passages (air/water supply passages 25/26 and air water supply 
pipes 23/24) formed in the front end body 1 can be easily and completely 
cleaned or washed when the front end cover 30 is removed from the front 
end body 1 after the endoscope is used. 
Moreover, since the relative position of the front end cover 30 to the view 
window 4 of the front end body 1 is automatically determined when the 
front end cover 30 is attached to the front end body 1, no adjustment of 
the orientation of the nozzle 37, during assembling, is necessary, thus 
resulting in a simple assembling operation. 
FIGS. 6 through 9 show a second embodiment of an endoscope according to the 
present invention. 
In the second embodiment, the front end cover 30 is formed of two different 
materials, unlike the first embodiment. The other structure of the 
endoscope in the second embodiment is substantially identical to that of 
the endoscope according to the first embodiment, and accordingly, the 
elements corresponding to those in the first embodiment are designated 
with like reference numerals, and no detailed explanation thereof will be 
given herein. 
In FIG. 6, the end cap (front end cover) 30 is comprised of a main body 301 
formed of a resilient elastically deformable material such as 
fluororubber, and a partial cover frame 302 provided on a part of the 
inner surface of the main body 301 to restrict the deformation of the main 
body 301. The cover frame 302 is provided only on the portion of the inner 
surface of the main body 301 that would otherwise contact the inner 
surface of the front end body 1. As shown in FIG. 9, the cover frame 302 
is in the form of a ring at the rear end thereof (left side in FIG. 9), 
and the remaining portion of the cover frame 302 is generally "C"-shaped 
to define an upper opening corresponding to the view window 4. 
The material of the cover frame 302 is not formed of a material having high 
resiliency like rubber, but instead the cover frame 302 is formed of a 
metal or plastic to exhibit a slight elastic deformability. The main body 
301 is aligned with the cover frame 302 integrally adhered thereto. 
The main body 301 and the cover frame 302 of the front end cover 30 are 
provided on the rear ends thereof with inner peripheral flanges 321 and 
322 that are fitted in the peripheral groove 7 formed on the front end 
body 1 so as to prevent the front end cover 30 from being accidentally 
disengaged from the front end body 1 when the front end cover 30 is 
attached to the front end body 1. 
The inner peripheral flange 321 and the inner peripheral flange 322 are 
formed of the same material as that of the main body 301 and the cover 
frame 302, respectively. Therefore, the inner peripheral flange 321 has 
the same resiliency as the main body 301 and the inner peripheral flange 
322 has the same elasticity as the cover frame 302. The resilient inner 
peripheral flange 321 is supported by the hard inner peripheral flange 
322. The cover frame 302 is provided on the annular rear end thereof with 
a pair of diametrically opposed slits 303 which open at the rear ends. The 
slits 303 facilitate the attachment of the front end cover 30 to the front 
end body 1. 
The nozzle 37 connected to the connecting groove 36 opens into the front 
end wall of the projection 35 of the main body 301 of the front end cover 
30, similar to the first embodiment. 
When the endoscope as constructed above is used, the cleaned front end 
cover (end cap) 30 is attached to the cleaned front end body 1. Upon 
attachment, the inner peripheral flanges 321 and 322 and the projection 
35, etc., are elastically deformed (expanded) due to the elasticity of the 
front end cover 30. When the front end cover 30 is secured to the front 
end body 1, the inner peripheral flanges 321, 322 and the projection 35, 
etc., are returned to their initial state due to the elastic restoring 
force, so that the inner peripheral flanges 321, 322 and the projection 35 
are firmly engaged in the peripheral groove 7 and the recessed groove 22, 
respectively. 
It should be noted that upon deformation, the cover frame 302 prevents the 
main body 301 from being excessively deformed. Specifically, an adequate 
deformation of the front end cover 30 takes place when the latter is 
attached to the front end body 1, thereby, ensuring that the front end 
cover 30 is securely attached to the front end body 1. When the front end 
cover 30 is attached to the front end body 1, the inner peripheral flanges 
321 and 322 of the front end cover 30 are engaged in the peripheral groove 
7 of the front end body 1. Thus, the front end cover 30 can be firmly 
secured to the front end body 1 without being accidentally detached 
therefrom. 
Thereafter, the machine screw 8 is inserted in the hole 33 of the front end 
cover 30 and screwed in the threaded hole of the front end body 1 to 
steadfastly secure the front end cover 30 to the front end body 1. 
In this state, the view window 4, the illumination window 5, and the 
treatment tool insertion opening 6 are exposed to the outside through the 
opening 31; the nozzle 37 faces the outer surface of the cover lens 15; 
and, the air supply passage 25 and the water supply passage 26 are 
connected to the connecting groove 36. 
Since the air and water supply passages between the connecting groove 36 
and the outlet port of the nozzle 37 are air-tight and water-tight sealed 
by the resilient main body 301 with respect to the front end body 1, there 
is no leakage of air or water therethrough. 
As can be understood from the above discussion, according to the present 
invention, since the front end cover 30 is provided with the main body 301 
formed of a resilient material and the cover frame 302 defining a 
deformation restricting member which restricts the elastic deformation of 
the main body 301, no excess deformation of the main body occurs upon 
attachment of the front end cover 30 to the front end body 1 of the 
endoscope. Consequently, an adequate elastic deformation of the main body 
necessary to attach the front end cover 30 to the front end body 1 takes 
place, so that the front end cover 30 can be securely attached to the 
front end body 1. 
Moreover, according to the present invention, since the nozzle 37 which is 
adapted to inject a cleaning fluid toward the outer surface of the view 
window 4 is formed in the front end cover 30 which is detachably attached 
to the front end body 1 of the endoscope, the nozzle 37 formed in the 
front end cover 30 and the fluid supply passages (air/water supply 
passages 25/26 and air/water supply pipes 23/24) formed in the front end 
body 1 can be easily and completely cleaned or washed when the front end 
cover 30 is removed from the front end body 1 after the endoscope is used. 
Although the invention has been described with reference to particular 
means, materials and embodiments, it is understood that the invention is 
not limited to the illustrated embodiments but extends to all equivalents 
within the scope of the following claims.