U.S. patent application number 09/725749 was filed with the patent office on 2001-08-30 for linear transmission member driving unit for endoscope.
Invention is credited to Akiba, Haruo.
Application Number | 20010018552 09/725749 |
Document ID | / |
Family ID | 26577883 |
Filed Date | 2001-08-30 |
United States Patent
Application |
20010018552 |
Kind Code |
A1 |
Akiba, Haruo |
August 30, 2001 |
Linear transmission member driving unit for endoscope
Abstract
In the endoscope configured so as to drive a tip end portion
movable lens for making the observation distance variable by the
linear transmission member and to rotate this linear transmission
member by a motor, a shaft of the motor is connected to a shaft
connecting member, and a sliding guide hole having a predetermined
length is formed on a cylindrical member wall of this shaft
connecting member. And, within this shaft connecting member, a
distal member of the linear transmission member is movably
disposed, and this distal member is provided with a pin engaging
with the sliding guide hole. This apparatus advances and retreats
the linear transmission member in the rotating shaft direction
during the bending operation, and provides a constant load to a
motor rotating shaft, making it possible to obtain a stable
magnification changing operation even though there may be a change
in posture of an endoscope insertion unit. In addition, an outside
diameter of the linear transmission member is formed to be smaller
than a soft portion within an angle portion to reduce a frictional
resistance during rotation.
Inventors: |
Akiba, Haruo; (Omiya-shi,
JP) |
Correspondence
Address: |
Ronald R. Snider
P.O. Box 27613
Washington
DC
20038-7613
US
|
Family ID: |
26577883 |
Appl. No.: |
09/725749 |
Filed: |
November 30, 2000 |
Current U.S.
Class: |
600/146 |
Current CPC
Class: |
F16C 1/02 20130101; A61B
1/00188 20130101 |
Class at
Publication: |
600/146 |
International
Class: |
A61B 001/00 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 3, 1999 |
JP |
11-344842 |
Mar 21, 2000 |
JP |
2000-77876 |
Claims
What is claimed is:
1. A linear transmission member driving unit for an endoscope,
comprising: a linear transmission member which performs a rotary
motion in order to drive an object; a protective tube which
rotationally envelops said linear transmission member; a motor, to
which said linear transmission member is shaft-connected; a chassis
to which said motor is fixed; and a mobile type linear transmission
member shaft coupling mechanism, which couples a shaft of said
motor fixed to said chassis to an end portion of said linear
transmission member, and to which said linear transmission member
is mounted so as to be able to move in a direction of a rotating
shaft of said motor.
2. The linear transmission member driving unit for an endoscope
according to claim 1, wherein said mobile type linear transmission
member shaft coupling mechanism configured by a cylindrical member
coupled and fixed to said motor shaft, and comprises: a shaft
connecting member in which a sliding guide hole having a
predetermined length in the direction of said rotating shaft is
formed; and a distal member of said linear transmission member,
which is disposed so as to move within a cylinder of said shaft
connecting member, and, in which there is provided a pin for
engaging with said sliding guide hole to slide, wherein a pin of
said distal member is caused to be engaged with said sliding guide
hole, whereby it is made possible to transmit rotation of said
motor to said linear transmission member and to move said linear
transmission member concerned in the direction of said rotating
shaft by a predetermined amount.
3. The linear transmission member driving unit for an endoscope
according to claim 1, wherein said motor and said mobile type
linear transmission member shaft coupling mechanism are disposed in
space on a side of an angle operating knob mechanism being mounted,
partitioned by said chassis within an operating unit, and said
motor and said protective tube are caused to be mounted to said
chassis concerned by the use of an integrally formed holding
member.
4. The linear transmission member driving unit for an endoscope
according to claim 1, wherein as said chassis, a plurality of
sheets of plates are superposedly disposed, and the rotating shaft
for said angle operating knob and said holding member are caused to
be mounted onto different plates respectively.
5. The linear transmission member driving unit for an endoscope
according to claim 1, wherein lubricating coat is applied to a
sliding member of said mobile type shaft coupling mechanism.
6. The linear transmission member driving unit for an endoscope
according to claim 2, wherein on an outer periphery of said distal
member, there are formed protruding portions in contact with an
inner wall of said shaft connecting member at two places where said
pin is sandwiched therebetween such that said linear transmission
member is caused to move by sliding of said protruding portions
within said shaft connecting member concerned.
7. A linear transmission member driving unit for an endoscope,
comprising: a movable member disposed on the side of the tip end of
an insertion unit having an angle portion and a soft portion; a
transmission coil, which is a linear transmission member for
transmitting the rotary driving force of said motor to said movable
member, comprising wire spirally wound; and a flexible protective
tube which rotationally envelops said transmission coil, wherein
said transmission coil, whose wire diameters are actually the same,
comprises two coil portions having different outside diameters, has
a small-diameter coil portion having smaller outside diameter
within said angle portion, and a large-diameter coil portion having
a larger outside diameter within said soft portion, these both coil
portions being coupled by a coupling member so as to be able to
integrally rotate at a connecting position between said angle
portion and said soft portion or in the vicinity thereof.
8. The linear transmission member driving unit for an endoscope
according to claim 7, wherein an outside diameter of said
small-diameter coil portion is set so as to be smaller than a size
in a direction of an end shaft when said angle portion goes into a
maximum curved state and said protective tube becomes deformed so
as to be flattened.
9. The linear transmission member driving unit for an endoscope
according to claim 7, wherein said movable member is a movable lens
among an object lens group provided at said tip hard portion.
10. The linear transmission member driving unit for an endoscope
according to claim 7, wherein said transmission coil comprises
bonded coil, and said bonded coil is configured by a double coil
comprising coils wound in opposite directions to each other.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a linear transmission
member driving unit for an endoscope, and more particularly to a
driving unit for rotating a linear transmission member for changing
an observation distance (including also changing depth of field) by
a motor.
[0003] 2. Description of the Prior Art
[0004] FIGS. 13A to 13C show a configuration of an endoscope
(scope) to which a mechanism for making the observation distance
(or depth of field) variable is applied, and FIG. 13A shows an
endoscope operating unit 1A, and on the left side of this operating
unit 1A, there are disposed an insertion unit 1B shown in FIG. 13B,
and a tip end portion (hard portion) 1C shown in FIG. 13C. In this
respect, the insertion unit 1B consists of the tip end portion 1C,
an angle portion 1D and a soft portion 1E. Behind the operating
unit 1A, there are disposed an air-supply/water-supply operating
button 2A, a suction operating button 2B, a freeze switch 3A, other
switches 3B and 3C, and an observation distance-variable switch 4
or the like.
[0005] Also, within the operating unit 1A, a motor 7 is mounted
onto a chassis (base) 6 by a holding member 8, and a linear
transmission member 10 formed of a multiple coiled spring is
mounted to this motor 7 through a shaft connector 11. This linear
transmission member 10 is placed within a flexible protective tube
(soft tube) 12 in order to avoid any interference with other
members, and this protective tube 12 is mounted to the chassis 6
with the holding member 13. These linear transmission member 10 and
protective tube 12 are disposed from the operating unit 1A to the
tip end portion 1C through the insertion unit 1B.
[0006] At the tip end portion 1C, there are disposed, as shown in
FIG. 13C, an object lens 15, a movable lens 16 and a prism 17, and
a CCD 18, which is a solid state imaging device, is optically
connected below this prism 17. A holding member 19 of the movable
lens 16 has a female threaded portion on top thereof, and on this
female threaded portion, there is disposed a rotary driving member
20 whose male screwed portion threadably engages with this female
threaded portion, and the linear transmission member 10 is coupled
to the rotary driving member 20.
[0007] According to such a configuration, rotation of the motor 7
is transmitted to the rotary driving member 20 at the tip end
portion 1C through the linear transmission member 10, and the
rotary motion of this rotary driving member 20 is converted into a
linear motion by means of threaded engagement with the holding
member 19. This enables the movable lens 16 to move back and forth,
making it possible to make an observation distance to be set in the
objective optical system variable.
BRIEF SUMMARY OF THE INVENTION
Object of the Invention
[0008] In an endoscope having the above described linear
transmission member driving unit, when an angle portion 1D of the
insertion unit 1B is curved as shown in FIG. 13B, the protective
tube 12 advances and retreats by a length of, for example, L1, and
the linear transmission member 10 advances and retreats by a length
of, for example, L2 in a rotating shaft direction. More
specifically, on focusing attention on a certain point P on the
protective tube 12, it moves forward (toward a position P1) by a
length L1 when the angle portion 1D is bent from a straight state.
Since both end portions of the protective tube 12 are fixed to the
neighborhood of its tip end portion 1C and the holding member 13,
when the insertion unit 1B is set to a just suitable length in a
straight state, the protective tube 12 is pulled during the bending
operation, and as a result, the tip end portion 1C is deviated from
a desired operating direction and tilts, so-called "crooked neck"
occurs. Thus, conventionally, the length of the protective tube 12
has been made a little longer than the armored body, and when it is
being bent, the scope insertion unit 1B is disposed so as to push
it into the protective tube 12.
[0009] On the other hand, one end of the linear transmission member
10 is connected to the rotary driving member 20, and is enveloped
in the protective tube 12, and therefore, when the angle 1D is
bent, the linear transmission member 10 moves backward (from
position P to P2) by, for example, length L2. For this reason,
there occurs an inconvenience that the linear transmission member
10 gives a load caused by pressure to the output shaft of the motor
7, and a change in posture of the insertion unit 1B changes the
moving speed of the movable lens 16, that is, the magnification
changing time. Thus, the linear transmission member 10 is mounted
with reference to the time during the bending operation of the
insertion unit 1B (during the maximum movement toward the motor
side), and when the insertion unit 1B is made straight, a moderate
pulling force is caused by a multiple coiled spring (linear
transmission member 10) which expands and contracts so as to cause
any load of the pressure not to be applied to the motor output
shaft.
[0010] Since, however, the degree of expansion and contraction of
the multiple coiled spring, which is the linear transmission member
10, changes depending upon bending (change in posture) of the
insertion unit 1B including the angle portion 1D even in the above
described configuration, the load to the motor output shaft cannot
be maintained constant, leading to a problem that the posture of
the insertion unit 1B causes variations in the magnification
changing operation (operation of variable power).
[0011] Also, the angle portion 1D configuring the endoscope is used
to point a tip hard portion 1C toward a desired direction, and is
constructed so as to be curved by remote control from an angle
operating device provided on the body operating unit 1A. This angle
portion 1D is curved in order to mainly change the observation
visual field of the endoscope. The insertion unit 1B is inserted
into a narrow body cavity in order to perform inspection and
diagnosis, and the overall length of the angle portion 1D is
desirably made as short as possible in order to smoothly and
reliably change the observation visual field even in the narrow
body cavity or the like. Moreover, in order not to cause any dead
angle in the observation visual field as far as possible, the angle
of curvature must be made as large as possible. Accordingly, when
the angle portion 1D is curved to the maximum angle of curvature,
the radius of curvature is exceedingly small, and yet it is
configured to be able to be abruptly curved such as, for example,
180.degree. or an angle of its vicinity. Also, since an insertion
course within the body cavity has a complicatedly curved shape, the
soft portion 1E coupled to the angle portion 1D has flexibility in
a curved direction, and this soft portion is constructed so as to
be able to be curved in any direction by following the curved
insertion course.
[0012] The angle portion 1D is constructed so as to be curved
larger than the soft portion 1E, and even in the protective tube 12
to be disposed within these, the inside of the angle portion 1D is
curved larger so that the soft protective tube 12 becomes deformed
as if it were crushed. Therefore, within this angle portion 1D, the
frictional resistance of the linear transmission member 10 and the
protective tube 12 becomes larger than the soft portion 1E,
resulting in irregularity of the rotary driving force of the linear
transmission member 10, and there is a problem that the driving
force lowers.
[0013] Further, in a state in which the angle portion 1D has been
curved to the maximum, the protective tube 12 may become deformed
so as to become flat, but since the linear transmission member 10
on the one hand has high rigidity, and a change in the sectional
shape is small, the linear transmission member 10 goes into a state
in which the linear transmission member 10 is pressed into contact
with the protective tube 12. Thus, when the linear transmission
member 10 is caused to be rotated in this state, there is a problem
that the frictional resistance due to rotation becomes large,
resulting in a greater motor load.
[0014] The present invention has been achieved in the light of the
above described problems, and is aimed to provide a linear
transmission member driving unit for an endoscope capable of
improving the transmission efficiency of a rotary driving force of
the linear transmission member, reducing the load onto the motor,
and maintaining operations such as magnification changing constant
even if there may be a change in the posture of the endoscope
insertion unit.
SUMMARY OF THE INVENTION
[0015] In order to attain the above described object, a linear
transmission member driving unit for an endoscope according to the
present invention is provided with: a linear transmission member
which performs a rotary motion in order to drive an object; a
protective tube which rotationally envelops this linear
transmission member; a motor, to which the linear transmission
member is shaft-connected; a chassis to which this motor is fixed;
and a mobile type linear transmission member shaft coupling
mechanism, which couples the shaft of the motor fixed to this
chassis to an end portion of the linear transmission member, and to
which this linear transmission member is mounted so as to be able
to move in a direction of the rotating shaft of the motor.
[0016] The mobile type linear transmission member shaft coupling
mechanism consists of a cylindrical member coupled and fixed to the
motor shaft, and comprises: a shaft connecting member in which a
sliding guide hole having a predetermined length in the direction
of the rotating shaft is formed; and a distal member of the linear
transmission member, which is disposed so as to move within a
cylinder of this shaft connecting member, and, in which there is
provided a pin for engaging with the sliding guide hole to slide,
and a pin of this distal member is caused to be engaged with the
sliding guide hole, whereby it is made possible to transmit
rotation of the motor to the linear transmission member and to move
the linear transmission member concerned in the direction of the
rotating shaft by a predetermined amount.
[0017] According to the above described invention, it becomes
possible for the distal member of the linear transmission member to
move in the direction of the rotating shaft by the length of the
sliding guide hole within the cylinder of the shaft connecting
member, and this linear transmission member advances or retreats in
the direction of the rotating shaft in response to the angle
bending operation, and therefore, the linear transmission member
consisting of a multiple coiled spring or the like does not expand
nor contract any longer (even if it expands or contracts, its
degree becomes small), but the load to be applied to the motor
rotating shaft becomes substantially constant. Therefore, even if
the insertion unit changes its posture, the magnification changing
operation or the like can be executed by the stable rotary driving
force.
[0018] In addition, the motor and the mobile type linear
transmission member shaft coupling mechanism are disposed in space
on the side of an angle operating knob mechanism being mounted,
partitioned by the chassis within an operating unit, and the motor
and the protective tube can be mounted to the chassis concerned by
the use of an integrally formed holding member. Thereby, the space
can be efficiently utilized, and any interference of the motor and
the mobile type linear transmission member shaft coupling mechanism
with various contents within the operating unit can be avoided. In
other words, within the displacement space at a side opposite to
the angle operating knob mechanism partitioned by the central
chassis within the operating unit, there are disposed contents such
as various conduit lines, light guides, and signal lines, and if
the driving mechanism were disposed here, there would be such
inconvenience that damage or the like to the contents occurs due to
the interference. Thus, the influence on such contents can be
avoided. Also, it becomes easy to position such that the motor
driving shaft coincides with the central position of the protective
tube.
[0019] Further, if as the above described chassis, a plurality of
sheets of plates are superposedly disposed, it will be possible to
mount the rotating shaft for the angle operating knob and the
holding member onto different plates respectively, and in this
case, there is an advantage that it becomes difficult for vibration
during rotation of the motor to transmit to the angle operating
knob.
[0020] It is preferable to apply lubricating coat to the sliding
member of the mobile type shaft coupling mechanism, and in this
case, it is capable of securing a smooth sliding operation by the
lubricating coat, and improving the abrasion resistance.
[0021] On the outer periphery of the distal member, there are
formed protruding portions in contact with the inner wall of the
shaft connecting member at two positions where the pin is
sandwiched therebetween such that the linear transmission member
can be moved by sliding of these protruding portions within the
shaft connecting member concerned. Thereby, it is possible to
realize a smooth moving operation of the linear transmission member
without the distal member tilting from the motor shaft direction
(while maintaining parallelism) even though a force for tilting
(falling) in a direction perpendicular to the moving direction may
be exerted on the linear transmission member and the distal
member.
[0022] A linear transmission member driving unit for an endoscope
according to another invention is provided with: a movable member
disposed on the side of the tip end of an insertion unit having an
angle portion and a soft portion; a transmission coil comprising
wire spirally wound, which is a linear transmission member for
transmitting the rotary driving force of the motor to this movable
member; and a flexible protective tube which rotationally envelops
this transmission coil. The transmission coil, whose wire diameters
are actually the same, consists of two coil portions having
different outside diameters, and has a small-diameter coil portion
having smaller outside diameter within the angle portion, and a
large-diameter coil portion having larger outside diameter within
the soft portion. These both coil portions are coupled by a
coupling member so as to be able to integrally rotate at a
connecting position between the angle portion and the soft portion
or in the vicinity thereof.
[0023] The outside diameter of the small-diameter coil portion is
preferably set so as to be smaller than the size in the direction
of the end shaft when the angle portion goes into a maximum curved
state and the protective tube becomes deformed so as to be
flattened. According to this another invention, it becomes possible
to efficiently transmit the rotary driving force by reducing the
frictional resistance.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] FIG. 1A shows a linear transmission member driving unit for
an endoscope according to a first embodiment of the present
invention, and is a side view obtained by enlarging a portion of
the mobile type linear transmission member shaft coupling mechanism
of FIG. 2B;
[0025] FIG. 1B is a sectional view taken on a line I-I in FIG.
1A;
[0026] FIG. 2A is a top view showing a linear transmission member
for an endoscope according to the first embodiment;
[0027] FIG. 2B is a side view showing the sectional view of one
portion of FIG. 2A;
[0028] FIG. 3A is an exploded view showing a distal member of the
linear transmission member according to the first embodiment;
[0029] FIG. 3B is a sectional view showing a portion obtained by
cutting off the distal member of the annular protruding portion of
the linear transmission member (including a shaft connecting
member);
[0030] FIG. 4A is a view showing layout of each member on the side
on which the angle operating knob mechanism has been disposed in
the operating unit according to the first embodiment;
[0031] FIG. 4B is a view showing the side on which various conduit
lines, signal cable or the like are disposed, on the opposite side
to the operating unit of FIG. 4A;
[0032] FIG. 5 is a schematic structural view showing an endoscope
according to a second embodiment of the present invention;
[0033] FIG. 6 is an external view showing a tip end surface of the
insertion unit of the endoscope of FIG. 5;
[0034] FIG. 7 is a longitudinal sectional view showing the vicinity
of the tip end of the insertion unit;
[0035] FIG. 8 is a longitudinal sectional view showing a driving
mechanism for a movable lens of an observation portion;
[0036] FIG. 9 is a sectional view similar to FIG. 8, showing a
state in which the movable lens has been advanced;
[0037] FIG. 10 is an exploded perspective view showing a lens
assembly;
[0038] FIG. 11 is a sectional view showing a transmission coil
according to a second embodiment;
[0039] FIG. 12 is a sectional view showing states of the linear
transmission member and the protective tube when the angle portion
is curved;
[0040] FIG. 13A is a partially exploded view showing the operating
unit of the endoscope to which a mechanism for making a
conventional observation distance variable has been applied;
[0041] FIG. 13B is a view showing a configuration of a conventional
insertion unit of the endoscope; and
[0042] FIG. 13C is a view showing a configuration of a conventional
tip portion of the endoscope.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0043] First Embodiment
[0044] FIGS. 1 to 3 show a linear transmission member driving unit
for an endoscope (motor-side driving unit to be disposed in the
endoscope operating unit) according to a first embodiment, and FIG.
1A is an enlarged view showing the shaft coupling mechanism of FIG.
2B. In FIGS. 1 and 2, a chassis 22 comprises two sheets of plates
superimposed, is disposed at the center within the operating unit,
and the supporting shaft 23 of an angle operating knob is fitted in
and fixed to an upper side plate 22A of this chassis 22 [FIG. 2B].
Although detail of this fixation is not shown, the lower portion of
the supporting shaft 23 is fitted into a mounting hole 22AA of the
upper side plate 22A, and the supporting member of the angle
operating knob is fixed to the upper side plate 22A by a screw.
This angle operating knob curves the angle portion and the tip
portion through wire by rotation of a left-right angle operating
knob (45A) and an upper-lower angle operating knob (45B) to be
described later in FIG. 4.
[0045] A holding member 24 for the motor and the protective tube is
mounted to the lower side plate 22B of the chassis 22 by means of
two screws 25. More specifically, the holding member 24 of the
motor-side driving unit is mounted to a lower side plate 22B, which
is different from the upper side plate 22A, on which the supporting
shaft 23 of the angle operating knob has been mounted, whereby
vibration or the like during the motor driving are prevented from
transmitting to the angle operating knob side. Also, since the
entire driving unit shifts downward, space within the operating
unit can be effectively utilized in order to dispose other
members.
[0046] In this holding member 24, a tip screw portion G of the
motor 27 is threadably engaged with, and is fixed to a threaded
portion G within an annular portion 24A in the rear holding portion
and the protective tube 28 is held and fixed by means of combined
cylindrical portions 24B to 24D in the front holding portion. More
specifically, the screw portion G for threadably engaging with a
contact surface between the cylindrical portions 24B and 24C is
formed, and an outer periphery on the side of tip end of this
cylindrical portion 24B and an inner circumference of the
cylindrical portion 24D are made into a tapered surface
respectively, and between these tapered surfaces, there is provided
space for sandwiching the protective tube 28 therebetween.
Therefore, the cylindrical member 24C is threadably engaged with
and coupled with the cylindrical portion 24B in a state in which
the protective tube 28 is sandwiched between the cylindrical
portions 24B and 24D, thereby the protective tube 28 can be
reliably held and fixed.
[0047] On the other hand, the shaft 30 of the motor 27 is mounted
to the shaft connecting member 31. More specifically, the shaft 30
is inserted into the mounting hole 31A of this shaft connecting
member 31, and a D-cut surface of this shaft 30 is fastened by two
screws 32, whereby the motor shaft 30 is fixed to the shaft
connecting member 31. This shaft connecting member 31 has a
cylindrical member as the main body, and has a sliding guide hole
34 formed along the rotating shaft direction 100 at two places (may
be one place or the like) which, for example, oppose to each other
on the wall of the cylindrical member, and a stopper ring 35 is
mounted to its tip end with adhesive. The length of this sliding
guide hole 34 is set to be slightly longer than a spring
displacement (movement in the rotating shaft direction 100) of the
linear transmission member 37 when the angle portion has been
curved.
[0048] The end portion of the linear transmission member 37
consisting of a multiple coiled spring or the like disposed within
the protective tube 28 is inserted into the distal member (for
example, sleeve) 38 and fixed by soldering or the like, this distal
member 38 is constructed so as to slide within the cylindrical
member of this shaft connecting member 31, and the pin 40 is
mounted with a screw 41. FIG. 3 shows a state before the pin 40 is
mounted, and the distal member 38 shown is formed with a mounting
hole 38A in a direction perpendicular to the rotating shaft
direction 100, the pin 40 is inserted into this mounting hole 38A,
and a sharp point of the screw 41 is screwed in so as to apply to a
concave portion 40A in the pin 40, whereby the pin 40 is mounted to
the distal member 38.
[0049] As shown in FIG. 3A, annular projections 38B and 38C are
formed at two places before and after a pin mounting hole 38A on
the outer periphery of the distal member 38 concerned so as for the
distal member 38 to be able to smoothly slide without tilting and
with reduced frictional resistance within the shaft connecting
member 31. Further, lubricating plating is applied to the surfaces
of movable members such as the shaft connecting member 31, the
distal member 38 and the pin 40. More specifically, the above
described movable members are made of stainless steel, and their
surfaces will be coated with lubricating plating using plating
liquid containing Teflone (trade name). This coating provides
excellent abrasion resistance and slip properties to the movable
portions.
[0050] As shown in FIG. 3B, in the engagement between the sliding
guide hole 34 and the pin 40 in the shaft connecting member 31, the
width of the shaft connecting member 31 and the outside diameter of
the pin 40 are set to dimensions to cause no play in the rotating
direction to such a degree that the sliding is not prevented. This
setting enables the response on transmitting the rotation of the
motor 27 to the linear transmission member 37 to be made
excellent.
[0051] In the mobile type linear transmission member shaft coupling
mechanism using such a shaft connecting member 31, the distal
member 38 moves in the rotating shaft direction 100 within the
shaft connecting member 31 within a range in which the pin 40
slides within the sliding guide hole 34, and the engagement between
the sliding guide hole 34 and the pin 40 causes the linear
transmission member 37 and the distal member 38 to be fixed to the
shaft connecting member 31 in the rotating direction, and the
rotation of the motor 27 is transmitted to the linear transmission
member 37 through the motor shaft 30 and the shaft connecting
member 31.
[0052] FIGS. 4A and 4B show the disposition of each member in the
endoscope operating unit, and in an operating unit 44, there are,
as shown, disposed a left-right angle operating knob (rotational
member) 45A and an upper-lower angle operating knob 45B together
with an air-supply and water-supply operating button 2A, a suction
operating button 2B, a freeze switch 3A. The interior of the
operating unit 44 is divided into two spaces by a chassis 22
mounted at the central portion, and as shown in FIG. 4A, in the
space in which the angle operating knob mechanism is disposed, an
angle wire sliding portion 46 is mounted to the chassis 22, and
together with the angle wire sliding portion 46, there are provided
a motor 27, which is the mobile type linear transmission member
shaft coupling mechanism, a shaft connecting member 31, the
protective tube 28 which envelops the linear transmission member
37, or the like.
[0053] On the other hand, as shown in FIG. 4B, in the opposite-side
space to this operating unit 44, there are provided an air
supply/water-supply tube 48, a suction tube 49, signal cable 50, a
light guide bundle 51, a water jet tube 52 or the like. Such
disposition effectively utilizes the space within the operating
unit 44, and prevents the mobile type linear transmission member
shaft coupling mechanism from exerting influences such as vibration
upon other members.
[0054] The first embodiment has the above described configuration,
and as described above, the protective tube 28 is surely fixed to
the chassis 22 by the holding member 24 with a predetermined amount
to be pushed in. More specifically, when curving the insertion unit
(1B) including the angle portion (1D), the protective tube 28 is
pushed in and is disposed allowing for room, whereby when this
insertion unit is made straight, the protective tube 28 can be
prevented from being crushed by being pulled. On the other hand,
the linear transmission member 37 can be movably mounted in the
rotating shaft direction 100 by means of the mobile type shaft
coupling mechanism of the distal member 38 and the shaft connecting
member 31. Therefore, when the angle portion is curved by the angle
operating knobs 45A and 45B, the linear transmission member 37 is
to move in the rotating shaft direction 100.
[0055] FIG. 2B shows a state in which the linear transmission
member 37 and the distal member 38 have moved a little from the
positions of FIG. 1A, and when the angle portion, which has been,
for example, curved, is returned straight, the linear transmission
member 37 is pulled so that the distal member 38 thereof moves
forward (the left side of the figure) within the shaft connecting
member 31 as shown. Conversely, when it is curved, the distal
member 38 of the linear transmission member 37 moves backward
(right side of the figure).
[0056] As described above, the linear transmission member 37 moves
in the rotating shaft direction 100 in response to the angle
portion curving operation or the curving of the insertion unit
(change in posture), and therefore, it will not rotate in an
expanded state, but even if it may expand or contract, the amount
of expansion or contraction becomes small. Therefore, the load to
be applied to the motor shaft 30 becomes substantially constant,
and stable magnification changing operation is performed
irrespective of the change in posture of the scope insertion
unit.
[0057] The movement operation of the distal member 38 within the
shaft connecting member 31 is smoothly performed without rattling
by means of the lubricating plating and the existence of annular
projections 38B and 38C at two places. Further, since the holding
member 24 for the motor 27 and the protective tube 28 has been
mounted to a chassis plate (22B), which is different from a chassis
plate (22A), to which the supporting shaft 23 for the angle
operating knob has been fixed, it becomes difficult for vibration
caused by driving of the motor 27 and vibration caused by the
rotation of the linear transmission member 37 to transmit to the
angle operating knob, and there is an advantage that the operation
is caused not to perceive those vibrations.
[0058] As described above, according to the first embodiment, the
linear transmission member advances or retreats in the rotating
shaft direction in response to the angle curving operation, and
will not advance or retreat and yet the load onto the motor shaft
becomes constant. Therefore, even if there maybe a change in
posture of the insertion unit of the endoscope, stable operation,
for example, magnification changing speed or the like can be
obtained.
[0059] In addition, effective utilization of the space within the
operating unit improves the assembly property, and enables any
interference of the motor and the mobile type linear transmission
member shaft coupling mechanism with various contents within the
operating unit to be avoided. Also, since the motor and the
protective tube have been mounted to the integrally formed holding
member, it becomes easy to position so as to cause the driving
shaft of the motor to coincide with the center position of the
protective tube.
[0060] Further, since if as the chassis, a plurality of plates are
superposedly disposed, and the rotating shaft for the angle
operating knob and the holding member for the motor-side driving
portion have been mounted onto different plates respectively, there
is an advantage that it becomes difficult for vibration during
rotation of the motor to transmit to the angle operating knob.
[0061] Also, a smooth sliding operation can be secured by the
lubricating coat, the abrasion resistance is also improved, and
even when a force for tilting in a direction perpendicular to the
moving direction is exerted on the linear transmission member and
the distal member, the distal member does not tilt from the motor
shaft direction, but the linear transmission member can be smoothly
moved.
[0062] Second Embodiment
[0063] Next, with reference to FIGS. 5 to 12, the description will
be made of the configuration of a second embodiment according to
the present invention.
[0064] First, FIG. 5 shows the schematic configuration of the
entire endoscope. As seen from FIG. 5, the endoscope 101 is
generally constructed by providing the insertion unit 103 for the
body cavity or the like contiguous to the body operating unit 102,
and drawing a universal cord 104 from the body operating unit 102.
The insertion unit 103 provided contiguous to the body operating
unit 102 is divided into a tip hard portion 103A, an angle portion
103B and a soft portion 103C in order from the tip end side in
terms of the function and structure.
[0065] The tip hard portion 103A is made of a hard member, and on
its tip end surface, there are, as shown in FIG. 6, provided an
illumination portion 110, an observation portion 111, a treatment
tool guiding portion 112 and a washing nozzle 113. Further, a jet
water-supply portion 114 is opened. The angle portion 103B is
configured such that the tip hard portion 103A provided with the
observation portion 111 can be curved in various directions such as
up and down, and left and right by means of an angle knob 105
provided on the body operating unit 102 in order to turn the tip
hard portion 103A in a desired direction. Further, the soft portion
103C accounts for the greater part of the length of the insertion
unit 103, has flexibility in the curving direction, and is
constructed to have resistance to collapse, and therefore, it can
be bent in any direction along the insertion course.
[0066] FIG. 7 shows a section for a portion of the insertion unit
103 on the tip end side. As apparent from this drawing, the tip
hard portion 103A has a body block 120 made of, for example, metal,
and this body block 120 is formed with through holes which
penetrate in the axial direction at needed places. On the tip end
surface of the body block 120, there is mounted an insulating cap
121, which is fixed to the body block 120 with a set screw 122. The
angle portion 103B has a ring joint structure in which a
multiplicity of angle rings 123 are successively pivotally mounted
by means of pivot pins 124, and on the outer periphery of the ring
joint structure consisting of angle rings 123, there is provided a
covering member 125 including a metallic net and an external layer
consisting of fluororubber, EPDM, urethane rubber or the like.
Further, four pieces of operating wires 126 are extended from the
interior of the angle portion 103B toward the soft portion 103C,
and these operating wires 126 make a pair of upper and lower ones,
and of left and right ones respectively. When one of the pair of
upper and lower operating wires is pulled, and the other is let
out, the angle portion 103B is curved in the up-and-down direction,
while when one of the pair of left and right operating wires is
pulled, and the other is let out, the angle portion 103B is curved
in the right-and-left direction.
[0067] The angle portion 103B is curved up or down, left or right,
but the angle portion 103B is curved in this manner in order to
turn the tip hard portion 103A in a desired direction. Thereby, the
tip hard portion 103A of the insertion unit 103 can be turned in
the desired direction within the insertion course, which is curved
or branches. Also, when the insertion unit 103 has been disposed at
a position to perform observation or diagnosis within a body
cavity, the angle portion 103B is also curved on changing the
direction of the observation visual field. As regards the degree of
curvature when the angle is being operated in order to change the
observation direction, it is curved at a very large angle of
curvature such as 108.degree. or more as the maximum curved angle.
And yet since the angle is curved to the maximum angle of curvature
within the narrow body cavity, the length dimension of the angle
portion 103B is made very short as compared with the full length of
the soft portion 103C, and therefore, the angle portion 103B is to
be abruptly curved in the maximum angle of curvature state.
[0068] Of a multiplicity of angle rings 123 coupled with one
another constituting the angle portion 103B, a tip ring 123A
located at the extreme tip is coupled to the body block 120.
Therefore, in the insertion unit 103, a portion between the tip
surface of the insulating cap 121 and the tip ring 123A of the
angle portion 103B, and a pivotally-mounted portion with another
angle ring 123 to be pivotally mounted thereon is the hard
portion.
[0069] As regards the configuration of the observation portion 111
provided at the tip end portion of the tip hard portion 103A, the
description will be made with reference to FIGS. 8 to 10. In these
figures, reference numeral 130 denotes a lens assembly constituting
an objective optical system provided in an observation portion
mounting portion 111A (See FIG. 7) provided in the body block 120,
and this lens assembly 130 has an object lens group 131, and an
optical path from this object lens group 131 is to be bent with
90.degree. turned downward by means of a prism 132. At an image
focusing position of the object lens group 131, there is disposed a
solid state imaging device assembly 133 consisting of a solid state
imaging device 133A combined with the prism 132 and a substrate
133B thereof. Also, between the object lens group 131 and the prism
132, there is provided a filter 134 having a desired
characteristic, and further a beam limiting device (not shown) or
the like are provided in addition.
[0070] A part (one or a plurality) of lens 131A constituting the
object lens group 131 are movable lenses which are movable in the
optical axis direction, and the remaining lenses 131B are
stationary lenses. The stationary lens 131B is fixedly mounted to a
lens supporting frame 135 constituting a stationary lens frame 136,
and this lens supporting frame 135 is joined with the surface of
the prism 132. The movable lens 131A is mounted to a movable lens
frame, and this movable lens frame 136 is caused to slide along the
inner surface of the lens supporting frame 135, whereby the movable
lens 131A is to move in the optical axis direction between the
position indicated in FIG. 4 and the position indicated in FIG. 5.
This movable lens 131A is a movable member provided at the tip end
of the insertion unit 3.
[0071] As shown in FIG. 10, in order to cause the optical axis of
the movable lens 131A to accurately coincide with that of the
stationary lens 131B, the movable lens frame 136, in which the
movable lens 131A has been provided, is movable in the optical axis
direction within the lens supporting frame 135, and is fixedly held
in any other directions than it, that is, a direction perpendicular
to the optical axis and in the falling direction.
[0072] An arm portion 137 is provided contiguous to the movable
lens frame 136, and this arm portion 137 is conducted to the
outside through a slit 135A provided on the lens supporting frame
135 along the optical axis direction, and contiguous to a tip end
portion thereof, there is provided a nut portion 138. The dimension
of the arm portion 137 in the widthwise direction is substantially
the same as the groove width of the slit 135A, whereby the movement
of the movable lens frame 136 in the rotating direction is
regulated.
[0073] The above described configuration substantially regulates
any other movement of the movable lens frame 136 than in the
optical axis direction. The nut portion 138 is caused to move in a
direction parallel to the optical axis along the threaded shaft
140, whereby the movable lens frame 136 is to move in the optical
axis direction. The movable lens 131A has been made to be movable
in the optical axis direction in order to make, variable, at least
one of the observation depth, focusing multiplying factor and angle
of visibility or the like. Therefore, this movable lens 131A is a
movable member provided at the tip end of the insertion unit
103.
[0074] The movable lens 131A is movable by means of remote control
from the body operating unit 102. For this reason, a protruding
portion 135B is provided contiguous to the lens supporting frame
135, and a shaft branch portion 139, which has been formed in a
substantially cylinder shape, is provided contiguous to this
protruding portion 135B. The threaded shaft 140 comprises a
threaded lever portion 140A and a rotating shaft portion 140B, and
the rotating shaft portion 140B is inserted and fitted in an
insertion hole 139A formed in the shaft branch member 139 so as to
be able to freely rotate but not to move. The threaded lever
portion 140A projects from the shaft branch member 139 by a
predetermined length, and the nut portion 138 is threadably engaged
with the protruded portion of this threaded lever portion 140A.
[0075] Reference numeral 141 denotes a control cable, which is
constructed by inserting a transmission coil 143 through the
flexible protective tube 142. The tip end of the transmission coil
143 is coupled to the threaded shaft 140 through a coupling member
144. This coupling member 144 has the transmission coil 143, the
tip end portion of which has been inserted and fitted therein, and
is configured by a cylindrical portion 144A to be fixed by
soldering, brazing or the like, and the threaded lever portion 144B
to be threadably inserted into the threaded shaft 140. The threaded
lever portion 144B is threadably inserted into the threaded shaft
140, and is fixed with adhesive or the like. Therefore, the
flexible end of the transmission coil 143 becomes the proximal end
of the cylindrical portion 144A. On the other hand, the tip end of
the protective tube 142 is inserted and is fitted in a connecting
ring 145 threadably engaged with the proximal end of the shaft
branch member 39, is fixed by means such as bonding, and on the
side of the outer periphery of the protective tube 142, a clamping
ring 146 is fitted in, and is fixed by using adhesive or the like.
Therefore, the flexible end of the protective tube 142 is located
at the position of the proximal end of the connecting ring 145 and
the clamping ring 146. In this respect, if the connecting ring 145
and the clamping ring 146 differ in position of the end portion,
the position of the end portion of the member located closer to the
proximal end side becomes the position of the flexible end of the
protective tube 142.
[0076] When the proximal end of the transmission coil 143 is
rotated around the shaft within the protective tube 142, its
rotating force is transmitted to the threaded shaft 140, and this
threaded shaft 140 is rotated to move the nut portion 138 and the
movable lens frame 136 coupled thereto. During this period of time,
since the threaded shaft 140 is fixed so as not to move axially,
the outside diameter of the coupling member 144 is larger than the
hole diameter of the insertion hole 139A, and the rotating shaft
portion 140B of the threaded shaft 140 is formed with a flange
portion 140C. The coupling member 144 and the flange portion 140C
abut upon the end surfaces before and after the insertion hole 139A
respectively.
[0077] The control cable 141 is extended from the insertion unit
103 within the body operating unit 102, and is coupled to the
rotary driving unit described in the first embodiment.
[0078] As shown in FIG. 11, the transmission coil 143 has different
coil diameters in a portion within the angle portion 103B, and in a
portion within the soft portion 103C although the line diameter of
metallic wire constituting the transmission coil 143 is the same.
More specifically, between the connecting portion to the coupling
member 144 to be coupled to the threaded shaft 140 and the interior
of the angle portion 103B, there is a small-diameter coil portion
143A having a small coil diameter, while between the distal member
38 and the soft portion 103C, there is a large-diameter coil
portion 143B having a large coil diameter. These small-diameter
coil portion 143A and large-diameter coil portion 143B are coupled
with each other through a joint member 157 provided at the position
of a coupling portion between the angle portion 103B and the soft
portion 103C.
[0079] The joint member 157 is used to couple such that the
large-diameter coil portion 143B and the small-diameter coil
portion 143A are integrally rotated, and a coupling side to the
small-diameter coil portion 143A is a small-diameter rod portion
157A which substantially coincides with the inside diameter of this
small-diameter coil portion 143A, while a coupling side to the
large-diameter coil portion 143B is a large-diameter rod portion
157B which substantially coincides with the inside diameter of this
large-diameter coil portion 143B. A shift portion between the
small-diameter rod portion 157A and the large-diameter coil portion
143B is a flange portion 157C whose size does not exceed the
outside diameter of the large-diameter coil portion 143B. The
small-diameter rod portion 157A is inserted into the proximal end
of the small-diameter coil portion 143A, and the large-diameter rod
portion 157B is inserted into the tip end portion of the
large-diameter coil portion 143B, and in such a state, they are
fixed by means such as soldering respectively.
[0080] In this case, the transmission coil 143 at the coupling
portion between the small-diameter coil portion 143A and the
large-diameter coil portion 143B is to be made hard by a length
corresponding to that of the joint portion 157 provided. As shown
in FIG. 7, however, the coupling ring 158 has been provided at the
coupling portion between the angle portion 103B and the soft
portion 103C, and a length H along which the coupling ring 158 has
been positioned becomes a hard portion. Therefore, if the length of
the joint portion 157 is such a size as not to actually protrude
from this coupling ring 158, the flexibility of the insertion unit
103 in the bending direction will not be particularly affected even
if the transmission coil 143 becomes hard in this position.
[0081] The movable lens 131A is moved in the optical axis direction
not always when the angle portion 103B has been made straight, but
also the above-described movement may be performed even when this
angle portion 103B has been curved. Therefore, at this time, the
transmission coil 143 is to slide along the inner surface of the
protective tube 142. Therefore, at least the inner surface of the
protective tube 142 is made slippery, whereby the sliding
resistance is restrained to a minimum, but still when the
transmission coil 143 is strongly pressed against the protective
tube 142, the sliding resistance may be increased to cause
transmission unevenness in rotation, or to cause a locked state in
a serious case. When it is abruptly curved, the protective tube 143
becomes deformed so as to become flat against its shape retention.
Particularly when the angle portion 103B is curved to the maximum
angle of curvature, the protective tube 142 becomes deformed most
large. In this case, when the protective tube 142 is given rigidity
to such a degree as not to be easily bent in order to reduce the
degree of becoming flat, there arises inconvenience that the
bending rigidity of the entire insertion unit 103 is increased to
worsen the insertion ability.
[0082] From the foregoing, as shown in FIG. 12, in a state in which
no bending force is exerted on the protective tube 142, it is held
in a circular shape as indicated by an imaginary line, and when the
angle portion 103B is curved to the maximum angle of curvature, it
is assumed that it becomes deformed so as to become flat as
indicated by a solid line in FIG. 12. Even if it becomes most flat,
space to such a degree that any movement within the protective tube
142 of the transmission coil 143 is not restrained as far as
possible is secured. Therefore, assuming D.sub.1 of FIG. 12 to be
an outside diameter of the small-diameter coil portion 143A of the
transmission coil 143, and D.sub.2 to be a dimension of a minor
axis when the protective tube 142 has been most flattened, D.sub.2
is made equal to D.sub.1 or to be a larger dimension. Thereby, even
when the angle portion 103B is curved to the maximum angle of
curvature, the transmission coil 143 is caused to have space in
which the transmission coil 143 is capable of still moving within
the section of the protective tube 142. In other words, however the
protective tube 142 maybe flattened, a sufficient difference in
diameter is allowed between the inside diameter of the protective
tube 142 and the outside diameter of the transmission coil 143 so
as to secure at least larger space than the outside diameter of the
transmission coil 143. In the transmission coil 143, a portion
located within the angle portion 103B has been set to the
small-diameter coil portion 143A for this reason. Therefore, the
smaller the outside diameter of the small-diameter coil portion
143A is, the transmission coil 143 can be smoothly rotated with a
light load even when the angle portion 103B has been curved.
[0083] In the soft portion 103C, its curvature is gentle even if it
is curved along the insertion course, and therefore, in a state in
which it is inserted into a body cavity, there is no possibility
that the protective tube 142 becomes deformed so as to be flattened
within this soft portion 103C, and therefore, it is not necessary
to make a difference in diameter between the outside diameter of
the transmission coil 143 and the inside diameter of the protective
tube 142 much large. For this reason, of the transmission coils
143, a portion located within the soft portion 103C is set to the
large-diameter coil portion 143B, whereby the difference in
diameter with the inside diameter of the protective tube 142 is
made into a minimum size required. Since the soft portion 103C has
a much longer size than the angle portion 103B, the difference in
diameter between the transmission coil 143 and the protective tube
142 in this portion is made small, whereby the fluctuation width in
the length of conduction of the transmission coil 143 from the
protective tube 142 can be restricted to a minimum when the
insertion unit 103 is narrow.
[0084] According to the second embodiment, there is exhibited an
effect on driving a movable member provided at the tip end of the
insertion unit that the frictional resistance between the
transmission coil and the protective tube can be restricted to a
minimum.
[0085] In this respect, in each embodiment described above, the
description has been made of a member for moving a part of an
object lens group constituting an objective optical system of an
electronic endoscope in the optical axis direction, but the movable
member provided at the endoscope and the tip end portion of the
insertion unit thereof is not limited thereto. Also, the linear
transmission member has been driven by a motor, but the structure
can be arranged so as to drive by manual operation or the like.
* * * * *