An endoscope according to an embodiment includes an elongated insertion section including a bending section configured to bend in at least an up-down direction by internally-disposed two or more wires being towed, an operation section including a grasping section, the operation section, a bending operation unit including a joystick for bending the bending section and provided in the operation section, two actuators respectively including turning shafts, the two turning shafts being internally disposed in the grasping section in a longitudinal direction of the grasping section, the two actuators being disposed side by side along a plane parallel to an operation direction of an operation member for bending the bending section in the up-down direction, and a conversion mechanism including a rotation torque transmission mechanism and a tensile force transmission mechanism, the conversion mechanism converting the rotation torque into the tensile force.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an endoscope in which a bending operation of a bending section is possible by an actuator.

2. Description of Related Art

An endoscope is widely used in a medical field and an industrial field. The endoscope includes an elongated insertion section, and an observation optical system is provided at a distal end portion of the insertion section. Further, some endoscope includes a bending section in a distal end side portion of the insertion section. The bending section enables the distal end portion of the insertion section to bend in upward and downward two directions or upward, downward, left, and right four directions. By providing the bending section in the insertion section, it is possible to achieve improvement of insertability into a subject and change a visual field direction to perform a wide-range observation.

An operation member provided in an operation section is operated by a user of the endoscope, whereby bending of the bending section is performed. For example, International Publication No. 2016/147457 discloses an endoscope in which an operation member is, for example, a joystick. In the endoscope, proximal ends of four wires inserted through an insertion section are fixed to four arm members fixed to a proximal end portion of the joystick. Distal ends of the respective wires are connected to predetermined positions of bending pieces of a bending section. A user tilts the joystick, whereby the four wires inserted through the insertion section are towed and slacked and the bending section bends.

There has also been proposed an endoscope in which a towing and slacking operation of the four wires is performed using an actuator such as a motor. For example, Japanese Patent Application Laid-Open Publication No. 2013-158612 discloses an endoscope in which four wires are towed using a motor.

SUMMARY OF THE INVENTION

An endoscope according to an aspect of the present invention includes: an elongated insertion section including a bending section configured to bend in at least an up-down direction by internally-disposed two or more strip-shaped members being towed; an operation section including a grasping section grasped by a hand, the operation section being disposed on a proximal end side of the insertion section; a bending operation unit including an operation member for bending the bending section and provided in the operation section; two actuators each including turning shafts, the two turning shafts being internally disposed in the grasping section in a longitudinal direction of the grasping section, the two actuators being disposed side by side along a plane parallel to an operation direction of the operation member for bending the bending section in the up-down direction; and a conversion mechanism including a rotation torque transmission mechanism to which rotation torque of the two turning shafts is transmitted and a tensile force transmission mechanism configured to transmit a tensile force for pulling the two or more strip-shaped members, the conversion mechanism converting the rotation torque into the tensile force.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT

An embodiment of the present invention is explained below with reference to the drawings.

Configuration of an Endoscope Apparatus

FIG.1is a configuration diagram showing a configuration of an endoscope apparatus according to the present embodiment. An endoscope apparatus1includes an endoscope2, a main body apparatus3. and a monitor4.

The endoscope2includes an elongated insertion section5, an operation section6, and a connection cord7. The connection cord7extends from a side portion of the operation section6, and various signal lines and the like are inserted through the connection cord7. The connection cord7includes a connector7aat one end. The connector7ais configured to be connectable to a connector (not shown) of the main body apparatus3.

The insertion section5includes a distal end portion11, a bending section12, and a flexible tube section13in order from a distal end. The distal end portion11includes an observation window21(FIG.2) and an illumination window. illumination light is emitted from the illumination window, and reflected light from a subject is received by an image pickup device23b(FIG.2) in the distal end portion11through the observation window21.

The operation section6is disposed on a proximal end side of the insertion section5. The operation section6includes a grasping section6ato be grasped by a surgeon, who is a user of the endoscope2, with one hand and an operation main body section6bprovided on a proximal end side (an upper side inFIG.1) of the grasping section6a. The grasping section6ais a portion grasped by a hand of the surgeon. A bending operation unit36includes a joystick14functioning as an operation member for bending the bending section12and is provided in the operation main body section6b. The joystick14is an operation member for bending the bending section12in an up-down direction and a left-right direction.

The insertion section5is inserted into the subject from the distal end portion11. For example, the surgeon, who is the user of the endoscope2, holds the insertion section5with a right hand and performs advancing and retracting operation to and from an inside of the subject and grasps the grasping section6awith a left hand, operates the joystick14with a thumb of the left hand, and operates various operation buttons with other fingers.

The main body apparatus3is a video processor that controls an operation of the entire endoscope apparatus1and performs image processing for generating an endoscopic image. The main body apparatus3includes a processor3afor operation control and image generation processing. A signal of the generated endoscopic image is outputted to the monitor4connected to the main body apparatus3.

For example, when the surgeon presses a recording button of the operation main body section6b, a signal indicating that the recording button is pressed is transmitted to the processor3a. The processor3astores, based on the signal, a movie or a still image of the endoscopic image in a storage apparatus (not shown).

Accordingly, the surgeon can perform inspection of the inside of the subject by, for example, observing the inside of the subject and recording a necessary endoscopic image while viewing the endoscopic image displayed on the monitor4.

Configuration of the Distal End Portion of the Insertion Section

FIG.2is a sectional view of the distal end portion11and the bending section12. The observation window21, the illumination window (not shown), and an opening22are provided on a distal end face of the distal end portion11. The opening22is a distal end side opening of a treatment instrument insertion channel24provided in the insertion section5. A treatment instrument and the like can be inserted through the treatment instrument insertion channel24, the surgeon is capable of projecting and retracting a distal end portion of the treatment instrument from the opening22.

An image pickup unit23is incorporated in the distal end portion11. The image pickup unit23includes a lens group23aand the image pickup device23b. A plurality of signal lines extending from the image pickup device23bare electrically connected to the main body apparatus3through the insertion section5, the operation section6, and the connection cord7.

The distal end portion11includes a distal end rigid member25, the image pickup unit23is fixed to the distal end rigid member25.

A distal end of the bending section12is connected to a proximal end of the distal end portion11. In the distal end portion11, a substantially cylindrical distalmost bending piece26configuring the bending section12is fixed to the proximal end side of the distal end rigid member25. An outer circumference of the distalmost bending piece26is covered by bending rubber27. Four wire fixing sections (not shown) are provided in a circumferential direction on an inner circumference of the distalmost bending piece26. A distal end of one wire28inserted through the insertion section5is fixed to the respective wire fixing sections. Proximal ends of four wires28reach an inside of the operation section6.

On the proximal end side of the distalmost bending piece26, a plurality of bending pieces29are consecutively connected along a longitudinal axis CX of the insertion section5. Each of the bending pieces29is connected to an adjacent bending piece29by two rivets29a. More specifically, the plurality of bending pieces29are coupled such that two bending pieces29adjacent to each other along the longitudinal axis CX are turnable around an axis formed by the two rivets29aIn other words, a turning axis of the two bending pieces29adjacent to each other is defined by the two rivets29a. The plurality of bending pieces29are turnably coupled by a plurality of rivets29aalong the longitudinal axis CX such that two turning shafts adjacent to each other are different by 90° in a circumference direction.

In this way, the bending section12bends in the up-down direction and the left-right direction by towing the wires28, which are internally-disposed strip-shaped members.

Configuration of the Operation Section

FIG.3is a front view of the operation section6.FIG.4is a sectional view taken in a longitudinal direction of the operation section6.FIG.5is a sectional view of the operation section6taken along a V-V line inFIG.4.

As explained above, the operation section6includes the grasping section6aand the operation main body section6b. A connecting section31, to which a proximal end of the insertion section5is connected, is provided at a distal end of the grasping section6a. A bend preventing member32made of resin covering a part of the connecting section31and a proximal end portion of the insertion section5is provided at a distal end of the connecting section31.

The grasping section6aincludes a tubular exterior member33made of resin. The grasping section6ahas a shape slightly thinned from the operation main body section6bside toward the connecting section31side.

As shown inFIG.5. a cross section of the grasping section6aorthogonal to a longitudinal axis OX (FIG.3) of the grasping section6ahas a substantially partially elliptical shape. The cross section of the grasping section6ahas a shape extending in a direction of a longitudinal axis LO of a substantially partial ellipse.

in other words, the grasping section6ahas a shape extending in a longitudinal direction (a direction of the longitudinal axis OX), and a sectional shape of the grasping section6aorthogonal to the longitudinal direction has anisotropy.

When bending the bending section12in the up-down direction, the surgeon moves the joystick14in a direction indicated by an arrow UDA of an alternate long and short dash line inFIG.4. Accordingly, as shown inFIG.5, in the sectional shape orthogonal to the longitudinal direction of the grasping section6a, a dimension L1 in a direction parallel to a plane parallel to an operation direction of the joystick14for bending the bending section12in the up-down direction is larger than a dimension L2 in a direction perpendicular to the plane.

As shown inFIG.4. the grasping section6aincludes a treatment instrument insertion section34. The treatment instrument insertion section34includes a treatment instrument insertion opening34ainto which various treatment instruments (not shown) can be inserted. The treatment instrument insertion opening34ais a proximal end side opening of the treatment instrument insertion channel24.

The operation main body section6bincludes an exterior member35fixed to a proximal end portion (a portion on an upper side inFIG.4) of the exterior member33. The bending operation unit36including the joystick14is disposed in and fixed to. via a cover member35a, an opening provided in a part of the exterior member35.

The bending operation unit36includes the joystick14, which is an operation member, a detection apparatus36afixed to the cover member35a, and a skirt member36bcovering a lower part periphery of the joystick14. The cover member35ais a member fixed to the exterior member35to cover a part of the exterior member35. The detection apparatus36ais provided at a proximal end portion of the joystick14and includes a circuit board36a1that detects a tilting direction and a tilting angle in a tilting operation of the joystick14and outputs a tilting signal including information concerning the detected direction (tilting direction) and the detected angle (tiling angle). One end of a signal cable36a2is connected to the circuit board36a1. The signal cable36a2is inserted through the connection cord7. The other end of the signal cable36a2is electrically connected to the processor3aof the main body apparatus3. The signal cable36a2includes a plurality of signal lines for transmitting the tilting signal indicating the tilting direction and the tilting angle of the joystick14and a control signal from the processor3a

Further, a plurality of signal lines36a3(FIG.6) also extend from the circuit board36a1. One ends of the respective signal lines36a3are connected to the circuit board36a1. The other ends of the respective signal lines36a3are connected to one motor52. The circuit board36a1outputs, via the plurality of signal lines36a3, driving signals for driving two motors52to the two motors52. The respective motors52are actuators that operate according to a control signal from the circuit board36a1.

The tilting signal of the joystick14is transmitted to the processor3aof the main body apparatus3via the signal cable36a2. The processor3agenerates, based on the tilting signal, a control signal for controlling operations of the two motors52and outputs the control signal to the circuit board36a1via a control signal line included in the signal cable36a2. The circuit board36a1generates, based on the received control signal, driving signals for driving the respective motors52and outputs the driving signals to a plurality of motors52via the plurality of signal lines36a3.

Note that a plurality of signal lines for driving the plurality of motors52may be inserted through the connection cord7, the processor3aand the plurality of motors52may be directly connected. In that case, the processor3agenerates, based on the tilting signal received from the circuit board36a1. driving signals for driving the respective motors52and outputs the driving signals to the respective motors52.

The bending operation unit36is provided on an opposite side of the treatment instrument insertion section34with respect to the longitudinal axis OX of the grasping section6a. More specifically, as shown inFIG.4, when the operation section6is viewed to face the joystick14of the bending operation unit36, the treatment instrument insertion section34is provided on a distal end side (a lower side inFIG.4) of the grasping section6aon an opposite side (a left side inFIG.4) of the joystick14with respect to the longitudinal axis OX.

When bending the bending section12in the up-down direction, the surgeon moves the joystick14in the direction indicated by the arrow UDA of the alternate long and short dash line inFIG.4. Accordingly, a movement of a distal end portion of the joystick14at the time when the bending section12is bent in the up-down direction is a movement in a plane including the longitudinal axis LO of the cross section of the grasping section6a.

When bending the bending section12in the left-right direction, the surgeon tilts the joystick14in a direction orthogonal to the direction indicated by the arrow UDA of the alternate long and short dash line inFIG.4. In other words, a movement of the distal end portion of the joystick14at the time when the bending section12is bent in the left-right direction is a movement in a direction orthogonal to the longitudinal axis LO of the cross section of the grasping section6a.

Two button switches37and38are provided in the operation main body section6b. and the respective button switches37and38are switches to which any functions are allocated out of various functions concerning the endoscope apparatus1. As shown inFIG.4, the two button switches37and38are provided on an opposite side of the bending operation unit36with respect to the longitudinal axis OX of the grasping section6a. In other words, the two button switches37and38are provided on the same side as the treatment instrument insertion section34with respect to the longitudinal axis OX of the grasping section6a. The two button switches37and38are disposed at an interval in the direction of the longitudinal axis OX of the grasping section6aon the exterior member35.

Two signal lines37aand38aextending from the two button switches37and38are electrically connected to the processor3aof the main body apparatus3through the connection cord7.

Further, a cylinder39. to which a suction button (not shown) is detachably attachable, is provided in the operation main body section6b. The surgeon can perform suction of blood and the like from the opening22of the distal end portion11of the insertion section5by pressing the suction button attached to the cylinder39. One end of a suction tube40is connected to the cylinder39. The other end of the suction tube40is connected to a branch connector42via another tube41.

The branch connector42includes an internal channel branching in a Y shape. An opening on the insertion section5side of the branch connector42communicates with the treatment instrument insertion channel24. Further, in the branch connector42, the treatment instrument insertion opening34aand the treatment instrument insertion channel24communicate. Further, the cylinder39and the treatment instrument insertion channel24also communicate. Each of the treatment instrument insertion section34, the tube41, and the treatment instrument insertion channel24is connected to the branch connector42by a connection member44such as a pipe sleeve.

A connecting section6cfor connection to the connection cord7is provided on a side surface of the operation main body section6b.

In the operation section6, a driving unit43including two motors for towing and slacking the four wires28and bending the bending section12is incorporated.

Configuration of the Driving Unit

FIG.6is a front view of the driving unit43provided in the operation section6.FIG.7is a perspective view of the driving unit43provided in the operation section6.FIG.6is a view of the bending operation unit36and the driving unit43viewed from a rear side of the bending operation unit36.

The driving unit43includes a support plate51. The support plate51is made of metal such as stainless steel and has a shape obtained by partially cutting an elongated plate member and bending various portions of the plate member. The support plate51is fixed to the exterior member35by screws51a(FIG.5).

A fixing plate53for supporting and fixing the two motors52is fixed to the support plate51. A latch plate52afor the respective motors52is fixed to the fixing plate53by a screw53a, whereby the two motors52are fixed to the fixing plate53. The fixing plate53has a shape bent in a crank shape, and one end of the fixing plate53is fixed to the support plate51by a screw51b. The two motors52are fixed to the other end of the fixing plate53to sandwich the fixing plate53.

As shown inFIG.4. the two motors52are disposed on an upper side (that is, a side close to the joystick14) of the grasping section6asuch that, when the surgeon grasps the grasping section6a. the two motors52are located on an inner side of a palm of a hand grasping the grasping section6a.

One end side portion (an upper side portion ofFIG.6) of the support plate51is a pulley fixing section51A. The pulley fixing section51A is bent in an angular U shape. Two pulley shafts61aof two pulleys61are fixed to the pulley fixing section51A. The two pulley shafts61aare disposed to be monoaxial between two plate sections formed by being bent in a U shape. The respective pulleys61are provided in the pulley fixing section51A of the support plate51to be turnable around the pulley shafts61aThe respective pulley shafts61ainclude bevel gears61b, which are turning members. The respective pulleys61are made of metal such as stainless steel. The respective pulleys61include pulley grooves in outer circumferential portions, and wires28aare laid in the pulley grooves and are towed by a tensile force by the turning.

Bevel gears52c. which are turning members, are provided at distal end portions of turning shafts52bof the respective motors52. The bevel gears52cturn according to the turning of the turning shafts52b. The respective motors52and the respective pulleys61are disposed such that the turning shafts52bof the respective motors52are orthogonal to the pulley shafts61aof the respective pulleys61and the respective bevel gears61bscrew with one bevel gear52c. The respective turning shafts52band the respective bevel gears52care made of metal such as stainless steel.

A fixing member71that turnably fixes the two turning shafts52bof the two motors52is fixed to the support plate51. A latch member71a(FIG.7) is fixed to the fixing member71, and the latch member71ais fixed to the support plate51by screws71b.

The fixing member71includes two bearings71c(FIG.4) that support the two turning shafts52b. The respective turning shafts52bare inserted through holes of the bearings71cto thereby be fixed to the support plate51to be turnable.

The respective bevel gears52cturning according to the turning of the turning shafts52bof the respective motors52are screwed with the bevel gears61bof the pulleys61. Therefore, when the turning shafts52bof the respective motors52turn, the pulleys61also turn.

As explained above, the respective motors52. which are the actuators, include the turning shafts52b. The two turning shafts52bof the two motors52are internally disposed in the grasping section6ain the direction of the longitudinal axis OX of the grasping section6a. The two motors52are disposed side by side along the plane parallel to the operation direction (the direction indicated by the arrow UDA) of the joystick14for bending the bending section12in the up-down direction.

The bevel gears52cprovided in the respective turning shafts52band the bevel gears61bprovided in the pulleys61configure a rotation torque transmission mechanism to which rotation torque of the turning shafts52bis transmitted. As shown inFIG.4, the four bevel gears52cand61bconfiguring the rotation torque transmission mechanism are disposed on the bending operation unit36side in the operation section6. One bevel gear52cand one bevel gear61bscrewing with the bevel gear52cconfigure one torque conversion mechanism. The respective motors52transmit rotation torque to the one torque conversion mechanism. The operation section6includes two torque conversion mechanisms.

In one of the two pulleys61, one end of each of two wires28afor up-down bending is fixed in the pulley groove. In the other of the two pulleys61, one end of each of the two wires28afor left-right bending is fixed in the pulley groove. The two wires28aare fit in the grooves of the pulleys61such that one of the two wires28ais towed and the other of the two wires28ais slacked by the turning of the respective pulleys61.

When the respective pulleys61turn in one direction, the respective pulleys61tow one of the two wires28aand slack the other. When the respective pulleys61turn in the opposite direction, the respective pulleys61slack one of the two wires28aand tow the other.

Accordingly, the pulleys61, in which the respective bevel gears61bare provided, configure a tensile force transmission mechanism that transmits a tensile force for pulling the wires28a. The four bevel gears52cand61band the two pulleys61configure a conversion mechanism that converts rotation torque of the two motors52into a tensile force for the two wires28a.

Two guide members81are fixed to the support plate51by screws (not shown) to sandwich the two motors52. Each of the guide members81includes two holes81a. One wire28ais inserted through one hole81a. Accordingly, as shown inFIGS.6and7, four wires28aare inserted through four holes81aof the two guide members81fixed to the support plate51.

A guide member82is also fixed to the support plate51by screws82a. Proximal end portions of the four wires28inserted through the insertion section5are inserted through four holes82bformed in the guide member82. One wire28is inserted through one hole82b.

Proximal ends of the four wires28and distal ends of the four wires28aare connected by four coupling members84between the two guide members81and the guide member82. The respective coupling members84also include mechanisms that connect the proximal ends of the wires28and the distal ends of the wires28aand adjust length between the two wires28and28a.

The branch connector42is fixed by screws42aon an opposite side of the pulley fixing section51A of the support plate51.

Effects

In general, operation of an operation member such as a joystick is performed by a finger (for example, a thumb) of one hand (for example, a left hand) of a user who grasps the operation section6of the endoscope2. Accordingly, when towing of the respective wires28is performed by a mechanical mechanism, if an operation amount of force in tilting operation of the joystick increases, a large load is applied to the hand or the finger of the user to be a burden for the user.

In the case of the joystick, an operation amount of force for the joystick is determined according to a bending angle or the like of the bending section12. In order to reduce the operation amount of force, it is necessary to increase a size of an arm member to which proximal ends of the respective wires are connected. However, if the arm member increases in size, a size of the operation section6itself increases. If the size of the operation section6itself increases, it is difficult to grasp the operation section6. and operability for the user is thus lowered.

Therefore, in order to tow the respective wires with electric means, actuators such as motors can be used. However, depending on a way of disposition of two actuators in the operation section6, the size of the operation section6increases, the user cannot stably grasp the operation section6with one hand, and the operability of the operation section6is lowered.

In contrast, according to the embodiment explained above, since the two motors52having a relatively large weight are disposed side by side in the longitudinal axis LO direction in the grasping section6a, the grasping section6adoes not increase in size, the grasping section6acan be stably grasped, and the user can easily grasp the grasping section6a. As a result, the operability of the operation section6is high for the surgeon.

In particular, as shown inFIG.4, the two motors52are provided in the grasping section6asuch that the respective turning shafts52bare parallel or substantially parallel to the longitudinal axis OX. The two motors52are disposed side by side along a plane including the tilting direction (the direction indicated by the arrow UDA) of the joystick14in order to bend the bending section12in the up-down direction.

Therefore, according to the embodiment explained above, it is possible to realize an endoscope with an improved grasping property of an operation section for endoscope that performs a bending operation using actuators.

In the present embodiment, since the two pulleys61are disposed on the same axis, an outer diameter of the respective pulleys61can be increased in a possible range in the operation main body section6b.

In the respective modifications explained below, a configuration of an entire endoscope apparatus is the same as the configuration in the embodiment explained above. Therefore, the same components as the components in the embodiment explained above are denoted by the same reference numerals and signs and explanation of the components is omitted. Different components are mainly explained.

In the embodiment explained above, the two pulleys are disposed turnably on the same axis. However, in a modification 1, the two pulleys turn around axes different from each other.

FIGS.8and9are schematic configuration diagrams of the operation section6showing disposition of actuators in the operation section6according to the modification 1. InFIGS.8and9, only two motors52and two pulleys62are indicated by solid lines. An exterior member, a joystick, and the like other than the two motors52and the two pulleys62are indicated by alternate long and two short dashes lines.

An operation section6A shown inFIGS.8and9has a shape of a so-called grip type including an elongated rectangular parallelepiped grasping section6Aa. A proximal end of a flexible tube section13is connected to a distal end side (a lower side inFIG.8) of the grasping section6Aa. The connection cord7extends from a side surface of the grasping section6Aa.

FIG.8is a diagram of the operation section6A viewed from a palm side of the right hand when the surgeon grasps the grasping section6Aawith, for example, the right hand.FIG.9is a diagram of the operation section6A viewed from a joystick14A side with respect to a longitudinal axis OX1of the grasping section6Aawhen the surgeon grasps the grasping section6Aawith, for example, the right hand. The surgeon can operate the joystick14A with a thumb of the right hand while grasping the grasping section6Aawith the right hand.

The joystick14A is disposed in a slope section6Abformed on a proximal end side (an upper side inFIG.8) of the grasping section6Aa.

As shown inFIGS.8and9, the two motors52are disposed side by side along a side surface6Aa1of the grasping section6Aain the grasping section6Aa. A cross section of the grasping section6Aaorthogonal to the longitudinal axis OX1of the grasping section6Aahas a substantially rectangular shape. Accordingly, the two motors52are disposed in the longitudinal axis LO direction of the grasping section6Aa, the cross section of which is substantially rectangular.

Further, the turning shafts52bextending from the respective motors52tilt by a predetermined angle θ with respect to the longitudinal axis OX1such that an interval of the two bevel gears52cis larger than an interval of the two motors52.

At this time, as shown inFIG.8, a plane PL1orthogonal to one turning shaft52bof the two turning shafts52band a plane PL2orthogonal to the other turning shaft52bof the two turning shafts52bare not parallel, and cross at an angle 2θ.

In this way, each of the two motors52are disposed such that the turning shaft52btilts by the angle θ with respect to the longitudinal axis OX1. Consequently, it is possible to bring the two motors52close to each other. As a result, it is possible to effectively use a space in the grasping section6Aa.

According to the modification 1 as well, since the two motors52having a relatively large weight are disposed in the longitudinal axis LO direction in the grasping section6Aa, the cross section of which is rectangular, the grasping section6Aadoes not increase in size and the user can easily grasp the operation section6A. As a result, the operability of the operation section6A is high for the surgeon.

The operation section6A in the modification 1 explained above has the shape of the so-called grip type. However, an operation section in a modification 2 has a shape of a so-called gun grip type.

FIGS.10and11are schematic configuration diagrams of the operation section showing disposition of actuators in the operation section according to the modification 2. InFIGS.10and11, only two motors52and two pulleys62are indicated by solid lines. An exterior member, a joystick, and the like other than the two motors52and the two pulleys62are indicated by alternate long two short dashes lines.

An operation section6B shown inFIGS.10and11includes an elongated rectangular parallelepiped grasping section6Ba. The grasping section6Baincludes, on a distal end side, an extending section6Bbextending while tilting by an angle θ1 with respect to a longitudinal axis OX2of the grasping section6Ba. The proximal end of the flexible tube section13is connected to a distal end side (a left side inFIG.10) of the extending section6Bb. The connection cord7extends from a proximal end of the grasping section6Ba.

FIG.10is a diagram of the operation section6B viewed from a side facing the palm of the right hand when the surgeon grasps the grasping section6Bawith, for example, the right hand.FIG.11is a diagram of the operation section6B viewed from a joystick14B side with respect to a longitudinal axis OX2of the grasping section6Bawhen the surgeon grasps the grasping section6Bawith, for example, the right hand. The surgeon can operate the joystick14B with the thumb of the right hand while grasping the grasping section6Bawith the right hand.

The joystick14B is disposed on a surface portion on a distal end side (an upper side inFIG.10) of the grasping section6Ba. In other words, a bending operation unit including the joystick14B is disposed at an end portion on the insertion section5side of the grasping section6Ba.

As shown inFIGS.10and11, the two motors52are disposed side by side along a side surface6Ba1of the grasping section6Bain the grasping section6Ba. A cross section of the grasping section6Baorthogonal to the longitudinal axis OX2direction of the grasping section6Bahas a substantially rectangular shape. Accordingly, the two motors52are disposed in the longitudinal axis LO direction of the grasping section6Ba, the cross section of which is substantially rectangular.

InFIG.10, the two motors52are disposed in the grasping section6Basuch that the extending two turning shafts52bare parallel.

Note that, in the modification 2, as in the modification 1, the respective motors52may be disposed to tilt, by the angle θ with respect to the longitudinal axis OX2, the two turning shafts52bextending from the two motors52such that the interval of the two bevel gears52cis larger than the interval of the two motors52.

According to the modification 2 as well, since the two motors52having a relatively large weight are disposed side by side in a direction of a long diameter in a cross section orthogonal to the longitudinal axis OX2of the rectangular grasping section6Bain the grasping section6Ba, the grasping section6Badoes not increase in size and the user can easily grasp the grasping section6Ba. As a result, the operability of the operation section6B is high for the surgeon.

As explained above, according to the embodiment and the respective modifications explained above, it is possible to provide an endoscope with an improved grasping property of an operation section for endoscope that performs a bending operation using actuators.

Note that, in the embodiment and the respective modifications explained above, the operation section includes the joystick as the operation member for performing the bending operation. However, the operation member does not have to be the joystick. For example, the operation member may be a disk-like knob turnable around an axis or a cross key tiltable in upward, downward, left, and right directions.

Furthermore, according to the embodiment and the respective modifications explained above, the wires28a, which are the strip-shaped members, are laid in the pulley grooves on the outer circumferences of the pulleys61. However, gears or sprockets may be used instead of the pulleys. Roller chains meshing with the gears or the sprockets may be used instead of the wires.

In the embodiment and the respective modifications explained above, the endoscope2includes the bending section12bendable in the upward, downward, left, and right directions. One of the two motors52is for up-down direction bending and the other is for left-right direction bending. However, in the case of the endoscope2having a configuration in which the bending section12is bendable only in the up-down direction, one of the two motors52may be for upward direction bending and the other of the two motors52may be downward direction bending.

In other words, in the embodiment and the respective modifications explained above, the bending section12is bendable in the upward, downward, left, and right four directions. However, the bending section12may be bendable only in upward and downward two directions.

In that case, one of the two motors52tows or slacks the wires28aand28for upward direction bending via the turning shaft52band a bevel gear2c. The other of the two motors52tows or slacks the wires28aand28for downward direction bending via the turning shaft52band the bevel gear2c.

For example, the processor3acontrols the turning of the two motors52not to simultaneously pull the wires28aand28for upward direction bending and downward direction bending and, when the wires28aand28for upward direction bending are pulled, slack the wires28aand28for downward direction bending.

The present invention is not limited to the embodiment explained above. Various changes, alterations, and the like are possible within a range not changing the gist of the invention.