Endoscope

Abstract

To provide an endoscope which has a simple structure and can prevent co-rotations of an external cable.SOLUTION: A fixing member 110 rotating integrally with a knob 36 in a direction B around an axis is arranged inside an operation unit body 22, and a part of a light guide 28 in a longitudinal direction is fixed by a fixing part 112 of the fixing member 110. A light guide insertion space 70 is formed between the fixing part 112 and a distal end side opening portion 78A inside the operation unit body 22. A light guide 28B is inserted into and arranged in the light guide insertion space 70 so that tension is not applied to the light guide 28B between the fixing part 112 and the distal end side opening portion 78A even in a case where the fixing member 110 is rotated in the direction B around the axis by the knob 36.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to an endoscope having an insertion section. [Background technology]

[0002] Rigid endoscopes are known as endoscopes used in endoscopic surgery and the like. Among these rigid endoscopes, oblique endoscopes are known, whose viewing direction (observation direction) is diagonally forward relative to the insertion axis of the insertion section. The oblique endoscope comprises an insertion section that is inserted into the subject, and an operating section main body that is connected to the base end of the insertion section. Patent documents 1 and 2 describe such oblique endoscopes that are capable of changing the viewing direction.

[0003] The oblique endoscope described in Patent Document 1 has a shaft (insertion section), a handle (main operating section), and a rotating swivel. An objective lens is located at the distal end of the shaft. To change the direction of view, the rotating swivel is held and the shaft is rotated around its axis using the handle. This causes the direction of view of the objective lens to rotate around the axis of the shaft.

[0004] The oblique endoscope described in Patent Document 2 has an insertion section, an operation section main body, and a rotation operation ring. A distal optical system is located at the distal end of the insertion section. To change the direction of view, the rotation operation ring provided on the operation section main body is rotated to rotate the insertion section in a direction around its axis. This causes the direction of view of the distal optical system to rotate around the axis of the insertion section. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Special Publication No. 2021-510103 [Patent Document 2] U.S. Patent No. 5,621,830 Summary of the Invention [Problem to be solved by the invention]

[0006] In the oblique endoscope described in Patent Document 1, in order to change the direction of view by rotating the outer tube of the insertion section together with the tip optical system (objective lens) around the axis, the operating section main body must be rotated while holding the rotating swivel provided on the tip side of the operating section main body, which poses a problem of difficulty in operation.

[0007] On the other hand, the oblique endoscope described in Patent Document 2 employs a configuration in which the outer tube of the insertion section is rotated around the axis together with the distal optical system by rotating a rotation operation ring provided on the operation section main body. This configuration has the advantage of being easier to operate to change the field of view compared to the oblique endoscope described in Patent Document 1.

[0008] Incidentally, the oblique endoscope described in Patent Document 2 employs a configuration in which a distal optical fiber and a proximal optical fiber are connected to each other so as to be rotatable relative to each other using a rotary joint in order to prevent twisting (co-rotation) of the optical fiber and the external cable when the outer jacket is rotated. However, this configuration requires that the distal optical fiber and the proximal optical fiber be evenly arranged in a ring shape inside the operation unit main body, which can lead to a problem of a complex structure. As a result, the operation unit main body becomes larger, which is a factor that deteriorates operability.

[0009] Therefore, there is a need for the development of an oblique viewing scope that has a simple structure and can prevent co-rotation of external cables.

[0010] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an endoscope that has a simple structure and is capable of preventing co-rotation of an external cable. [Means for solving the problem]

[0011] An endoscope for achieving the object of the present invention comprises an outer tube constituting an insertion section, a tubular operation section main body connected to the base end side of the outer tube and supporting the outer tube rotatably in a direction around the axis of the insertion section, an annular rotation operation member fixed to the base end side of the outer tube and rotating the outer tube in a direction around the axis relative to the operation section main body, an outer tube inserted into the outer tube and rotatable integrally with the outer tube, a tip optical system provided on the tip side of the outer tube, a flexible light guide disposed in the space between the outer tube and the outer tube and having a light emitting end on the tip side of the outer tube, an inner tube inserted into the outer tube and rotatable in a direction around the axis relative to the outer tube, and a tip optical system provided on the tip side of the inner tube. the operating unit body has a fixing portion that fixes a portion of the light guide in the longitudinal direction and is rotatable around the axis integrally with the rotating operating member; a light guide insertion space is formed inside the operating unit body between the fixing portion and the tip-side opening, and the light guide is inserted into the light guide insertion space in a state where no tension is applied to the light guide between the fixing portion and the tip-side opening when the fixing member is rotated around the axis by the rotating operating member.

[0012] An endoscope for achieving the object of the present invention comprises a tubular operating section main body connected to the base end side of the outer tube and supporting the outer tube rotatably in a direction around the axis of an insertion section; an annular rotating operating member fixed to the base end side of the outer tube and rotating the outer tube in a direction around the axis relative to the operating section main body; an outer tube inserted into the outer tube and rotatable integrally with the outer tube; a distal optical system provided at the distal end side of the outer tube; a flexible light guide disposed in the space between the outer tube and the outer tube and having a light emitting end at the distal end side of the outer tube; an inner tube inserted into the outer tube and rotatable in a direction around the axis relative to the outer tube; the operating unit body includes an imaging unit that images light that has passed through the distal optical system, an external cable that is connected to the base end side of the operating unit body and through which a light guide is inserted from the distal opening into the interior, and a fixed member that is arranged inside the operating unit body and has a fixed part that fixes a part of the longitudinal direction of the light guide and is rotatable in a direction around the axis integrally with the rotating operating member, and inside the operating unit body, a light guide insertion space is formed between the fixed part and the distal opening, and the light guide that is inserted and arranged in the light guide insertion space has a length that is longer than the straight-line distance connecting the base end of the fixed part and the center of the distal opening.

[0013] According to one aspect of the present invention, the fixing member is preferably connected to the base end side of the outer cylinder and is rotatable about the axis integrally with the outer cylinder.

[0014] According to one aspect of the present invention, the fixing member is preferably formed of a ring-shaped member connected to the base end side of the outer cylinder, and has a fixing portion at a part of the circumference of the ring-shaped member.

[0015] According to one aspect of the present invention, it is preferable to provide a rotation stopper that restricts the range of rotation of the fixed member around the axis.

[0016] According to one aspect of the present invention, the light guide preferably has a length that allows the light guide to maintain a deflected state between the fixed portion and the distal end opening in the axial direction of the insertion portion within the range of rotation defined by the rotation stopper.

[0017] According to one aspect of the present invention, the rotary operation member is preferably provided on the distal end side of the operation portion main body and is configured as an annular member that is rotatable in an axial direction relative to the operation portion main body.

[0018] According to one aspect of the present invention, it is preferable that the external cable has a signal cable connected to the imaging unit and inserted through the inner cylinder, and the signal cable is inserted into the interior of the external cable from the tip-side opening.

[0019] According to one aspect of the present invention, the signal cable is preferably a plurality of separate wires.

[0020] According to one aspect of the present invention, the device comprises a tubular case connected to the base end side of the outer tube inside the operating unit main body and positioned closer to the axial tip side of the insertion unit than the light guide insertion space, a partition wall provided inside the case and perpendicular to the insertion axis of the insertion unit, and a magnetic coupling having a first magnet provided on the axial tip side and a second magnet provided on the axial base side with the partition wall between them, the first magnet being connected to the base end side of the inner tube, and it is preferable that the magnetic coupling and the case are rotatable relative to each other in the axial direction.

[0021] According to one aspect of the present invention, the distal end side of the external cable is preferably connected to the proximal end side of the second magnet via a beam-shaped connecting member extending in the axial direction within the light guide insertion space.

[0022] According to one embodiment of the present invention, the magnet has a signal cable connected to the imaging unit and inserted into the inner tube, and it is preferable that the first magnet and the second magnet are formed in a disk shape perpendicular to the insertion axis and each have an insertion hole through which the signal cable is inserted.

[0023] According to one aspect of the present invention, the fixing member is preferably fixed to the outer peripheral surface of the case, and the fixing portion of the fixing member is preferably positioned axially further towards the tip side than the insertion hole formed in the second magnet.

[0024] According to one aspect of the present invention, the peripheral edge of the opening at the tip end of the external cable is preferably formed into a rounded surface shape.

[0025] According to one embodiment of the present invention, it is preferable that the inner tube is provided with a proximal optical system at the tip end side, which guides light that has passed through the distal optical system to an imaging unit, the imaging unit is provided with an imaging element that images the light that has entered through the proximal optical system and outputs an imaging signal to a signal cable, and the distal optical system is rotatable around an axis relative to the proximal optical system and the imaging element. [Effects of the Invention]

[0026] The present invention has a simple structure and can prevent the external cable from rotating together. [Brief explanation of the drawings]

[0027] [Figure 1] FIG. 1 is a configuration diagram of an endoscope system equipped with an oblique endoscope. [Figure 2] FIG. 2 is an enlarged cross-sectional view of the tip of the insertion section. [Figure 3] FIG. 2 is a cross-sectional view of the operation unit main body. [Figure 4] FIG. 2 is a cross-sectional view of the outer cylinder and the case. [Figure 5] FIG. 2 is an enlarged cross-sectional view of the case and the cylindrical portion. [Figure 6] FIG. 2 is a front view of the first magnet and the second magnet as viewed from the partition wall side. [Figure 7] FIG. 2 is a side view of the first magnet and the second magnet. [Figure 8] FIG. 2 is a diagram showing the internal structure of the operation unit main body, illustrating the fixing member. [Figure 9] 10 is an explanatory diagram showing the posture of a light guide in a light guide insertion space. FIG. [Figure 10] 10 is an explanatory diagram showing the posture of a light guide in a light guide insertion space. FIG. [Figure 11] 10 is an explanatory diagram showing the posture of a light guide in a light guide insertion space. FIG. [Figure 12] 10 is an explanatory diagram showing the length of a light guide in a light guide insertion space. FIG. [Figure 13] FIG. 4 is a schematic diagram showing the configuration of a rotation stopper. DETAILED DESCRIPTION OF THE INVENTION

[0028] Fig. 1 is a configuration diagram of an endoscope system 12 that includes an oblique endoscope 10. As shown in Fig. 1, the endoscope system 12 includes the oblique endoscope 10, a processor device 14, a monitor 16, and a light source device 18. The oblique endoscope 10 is an example of the endoscope of the present invention.

[0029] The oblique endoscope 10 shown in Fig. 1 is a so-called rigid endoscope, and includes an insertion section 20 and an operation section main body 22. The insertion section 20 is an example of the insertion section of the present invention. The operation section main body 22 is a part that is held by a practitioner (not shown) when operating the oblique endoscope 10, and is configured in a cylindrical shape. The operation section main body 22 is an example of the operation section main body of the present invention.

[0030] The insertion section 20 is configured in a generally tubular (cylindrical) shape and is inserted into the body of a patient. The insertion section 20 has a distal end, a proximal end, and an insertion axis Ax.

[0031] The insertion section 20 includes an outer tube 30 that constitutes the insertion section 20. The operation section main body 22 supports the outer tube 30 rotatably in the axial direction around the insertion axis Ax (the circumferential direction indicated by arrow B of the insertion section 20; hereinafter simply referred to as the "axial direction B"). The outer tube 30 is an example of an outer tube of the present invention.

[0032] An annular knob 36 is fixed to the base end side of the outer tube 30. The knob 36 is a member that rotates the outer tube 30 in the direction B around the axis relative to the operation unit main body 22. By rotating the outer tube 30 with the knob 36, the field of view (observation direction, see optical axis OA in Figure 2) of the oblique endoscope 10 can be rotated in the direction B around the axis. The knob 36 is an example of a rotation operation member of the present invention.

[0033] A camera unit 24, which will be described later, is provided at the tip of the insertion section 20. A first signal cable 26 and a light guide 28 are inserted inside the insertion section 20.

[0034] The first signal cable 26, together with the second signal cable 27 described below, connects the camera unit 24 and the processor device 14. That is, the tip end of the first signal cable 26 is connected to the camera unit 24, and the base end of the first signal cable 26 is connected to the tip end of the second signal cable 27 inside the operation unit main body 22. The base end of the second signal cable 27 is connected to the processor device 14. The first signal cable 26 and the second signal cable 27 are examples of signal cables of the present invention. Note that in this example, the first signal cable 26 and the second signal cable 27 are exemplified as multi-core cables in which a plurality of wires (signal lines) are bundled together and surrounded by a shield conductor, and these are housed in a tubular outer sheath.

[0035] Light guide 28 has a light emitting end 28C (see FIG. 2) at its tip end, and light emitting end 28C is disposed at the tip end of outer tube 30. Light guide 28 also has a light incident end (not shown) at its base end, and this light incident end is connected to light source device 18. Light guide 28 may be, for example, a flexible light guide having a configuration in which multiple optical fibers are bundled into a single optical cable. Light guide 28 is an example of the light guide of the present invention.

[0036] The operation unit main body 22, which will be described in detail later, has an airtight space and a non-airtight space therein, and the base end side of the first signal cable 26 and the tip end side of the second signal cable 27 are connected at the boundary between the two spaces (see FIG. 3). This electrically connects the camera unit 24 and the processor device 14 via the first signal cable 26 and the second signal cable 27.

[0037] The processor device 14 generates an observation image (moving image) of the inside of the patient's body based on the imaging signal input from the camera unit 24 via the first signal cable 26 and the second signal cable 27, and displays this observation image on the monitor 16.

[0038] The light source device 18 supplies illumination light to the light guide 28. As a result, the illumination light is emitted from a light emitting end 28C (see FIG. 2) of the light guide 28 provided on the tip side of the outer tube 30.

[0039] Fig. 2 is an enlarged cross-sectional view of the tip of the insertion section 20. As shown in Fig. 2, the insertion section 20 includes a substantially tubular outer tube 30 parallel to the insertion axis Ax, an outer cylinder 32, and an inner cylinder 34. The outer tube 30 forms the outer peripheral wall of the insertion section 20. An opening on the tip side of the outer tube 30 is tilted from a position perpendicular to the insertion axis Ax.

[0040] The outer tube 32 is inserted into the outer tube 30. A distal end optical system 40 of the camera unit 24 is provided on the distal end side of the outer tube 32. The proximal end side of the outer tube 32 is connected to a tubular case 74 (see FIG. 3) inside the operation portion main body 22, as will be described in detail later. Furthermore, a space 31 for arranging a light guide 28 is formed between the inner peripheral surface of the outer tube 30 and the outer peripheral surface of the outer tube 32. The light guide 28 is inserted into the space 31 and fixed to the inner peripheral surface of the outer tube 30 and the outer peripheral surface of the outer tube 32. The outer tube 32 is an example of an outer tube of the present invention.

[0041] The inner tube 34 is inserted into the outer tube 32. The first signal cable 26 is inserted inside the inner tube 34. The proximal optical system 50 and the imaging section 60 that constitute the camera unit 24 are provided on the distal end side of the inner tube 34. The proximal end side of the inner tube 34 is connected to a connecting member 90 (see FIG. 3) inside the operation section main body 22, as will be described in detail later. The inner tube 34 is an example of an inner tube of the present invention.

[0042] 2, the camera unit 24 includes a distal optical system 40, a proximal optical system 50, and an imaging section 60. The symbol OA in the figure denotes the optical axis of the optical system of the camera unit 24.

[0043] The distal end optical system 40 is provided on the distal end side of the outer tube 32. The distal end optical system 40 is an oblique optical system that refracts light incident from a direction inclined with respect to the insertion axis Ax in a direction parallel to the insertion axis Ax and guides the light to the proximal end optical system 50. The distal end optical system 40 includes a distal end main body 42 and a distal end lens barrel 44 provided on the distal end main body 42. The distal end optical system 40 is an example of a distal end optical system of the present invention.

[0044] The tip portion body 42 constitutes the tip portion of the insertion portion 20 (outer cylinder 32) and is a cap that covers the tip portion barrel 44. The tip portion body 42 is formed in a generally tubular shape that is parallel to the insertion axis Ax. Furthermore, a cover glass 46 that is inclined to match the inclination angle of the objective lens 48a in the tip portion barrel 44 is provided at the opening on the tip side of the tip portion body 42.

[0045] Furthermore, the tip portion main body 42 is fixed to the inner peripheral surface of the outer tube 30. As a result, when the outer tube 30 is rotated in the direction B around the axis, the tip optical system 40 and the outer tube 32 rotate integrally with the outer tube 30 in the direction B around the axis.

[0046] The distal end barrel 44 houses an objective lens 48a, a prism 48b, and a lens 48c. The objective lens 48a is tilted from a position perpendicular to the insertion axis Ax and faces the cover glass 46. The objective lens 48a emits light incident through the cover glass 46 toward the prism 48b. The prism 48b refracts the light incident from the objective lens 48a, i.e., light incident from a direction tilted with respect to the insertion axis Ax, in a direction parallel to the insertion axis Ax, and then emits the light toward the lens 48c. The lens 48c is oriented perpendicular to the insertion axis Ax and emits the light incident from the prism 48b toward a lens 56 in the proximal end barrel 52 of the proximal optical system 50.

[0047] The configuration of the optical system within the distal barrel 44 is not particularly limited as long as it is possible to guide light incident from a direction inclined with respect to the insertion axis Ax into the proximal barrel 52 .

[0048] A cylindrical portion 45 extending toward the base end side of distal end barrel 44 is formed on distal end barrel 44. Cylindrical portion 45 is fitted onto the distal end of proximal end barrel 52 so as to be rotatable relative to the distal end in direction B around axis. This allows proximal end barrel 52 to be fitted onto distal end barrel 44 so as to be rotatable relative to the distal end in direction B around axis.

[0049] The proximal optical system 50 is provided on the distal end side of the inner tube 34, and guides light incident from the distal lens barrel 44 to the imaging unit 60. The proximal optical system 50 includes a proximal lens barrel 52, a holder 54, and a prism 55. The proximal optical system 50 is an example of the proximal optical system of the present invention.

[0050] The base end side of base end barrel 52 is fixed to the tip side of inner tube 34 via holder 54. As described above, the tip side of base end barrel 52 is fitted into the opening on the base end side of tubular portion 45 so as to be rotatable relative to the opening in direction B around axis. This allows one of tip end barrel 44 and base end barrel 52 to rotate relative to the other in direction B around axis. As a result, inner tube 34 inserted into outer tube 32 can rotate relative to outer tube 32 in direction B around axis.

[0051] A plurality of lenses 56 having an optical axis OA parallel to the insertion axis Ax are provided inside the base end lens barrel 52. Each lens 56 emits light incident from the tip end lens barrel 44 toward the prism 55.

[0052] The holder 54 is formed in a generally tubular shape parallel to the insertion axis Ax, and is fixed to the tip side of the inner tube 34. The holder 54 is also fitted onto and fixed to the base end side of the base end barrel 52. This connects the inner tube 34 and the base end barrel 52 by the holder 54, so that the inner tube 34, the holder 54, and the base end barrel 52 can rotate together relative to the outer tube 32 in the direction B around the axis.

[0053] A prism 55 is held in the opening on the base end side of holder 54, and an imaging unit 60 is further held via prism 55. Therefore, imaging unit 60 can rotate relative to outer cylinder 32 in direction B around axis via holder 54 and prism 55, integrally with inner cylinder 34 and base-end lens barrel 52.

[0054] The prism 55 refracts the incident light by 90 degrees after passing through the proximal lens barrel 52. Note that the prism 55 may be replaced by a mirror.

[0055] The imaging unit 60 captures an image of light (observation image) that passes through the distal optical system 40 and the proximal optical system 50 and is reflected by the prism 55. The imaging unit 60 includes an imaging element 64 and a circuit board 66. The imaging unit 60 is an example of the imaging unit of the present invention.

[0056] The imaging element 64 is mounted on a circuit board 66 and fixed to the prism 55, and is attached to the holder 54 via the prism 55. The imaging element 64 captures an image of light refracted by the prism 55 and outputs an imaging signal. The imaging element 64 may be a CCD (Charge Coupled Device) type image sensor or a CMOS (Complementary Metal Oxide Semiconductor) type image sensor. The imaging element 64 is an example of the imaging element of the present invention.

[0057] The circuit board 66 controls the driving of the imaging element 64. The distal end of the first signal cable 26 is connected to the circuit board 66 via a connector 68. The circuit board 66 outputs an imaging signal from the imaging element 64 to the first signal cable 26 via the connector 68.

[0058] Fig. 3 is a cross-sectional view of the operation portion main body 22. As shown in Fig. 3, the operation portion main body 22 is configured in a tubular shape parallel to the insertion axis Ax.

[0059] An annular knob 36 fixed to the base end of the outer tube 30 is provided on the distal end side of the operation unit body 22. The knob 36 is, for example, rotatably provided on the outer peripheral surface of the distal end side of the operation unit body 22 via a seal ring 38. As a result, the knob 36 is configured as an annular member that is rotatable in the direction B around the axis relative to the operation unit body 22. By rotating the knob 36 in the direction B around the axis, the outer tube 30 is rotated in the direction B around the axis relative to the operation unit body 22, and the outer tube 32 and the distal end optical system 40 (see FIG. 2; the distal end body 42 and the distal end lens barrel 44) are rotated in the same direction via the outer tube 30. This makes it possible to change the field of view (observation direction) of the oblique endoscope 10.

[0060] The base ends of the outer tube 32 and the inner tube 34 are inserted from an opening on the tip side of the operation unit body 22 to the inside of the operation unit body 22. An external cable 72, which will be described later, is connected to the base end side of the operation unit body 22. A light guide insertion space 70, which will be described later, is formed inside the operation unit body 22. A case 74 is also provided inside the operation unit body 22. The case 74 is located closer to the tip side than the light guide insertion space 70.

[0061] The distal end of the external cable 72 is connected to the proximal end of the operation unit main body 22, and the external cable 72 is provided integrally with the operation unit main body 22. The external cable 72 has a cable main body 76 that forms an outer sheath, and a connection tube 78 that is inserted and disposed inside the cable main body 76. The external cable 72 is an example of the external cable of the present invention.

[0062] The tip side of the connecting tube 78 is formed in a funnel shape, and the second signal cable 27 and the light guide 28 are inserted into the connecting tube 78 from its expanded diameter tip side opening 78A. The peripheral edge of the tip side opening 78A is formed in a rounded surface shape, which prevents the second signal cable 27 and the light guide 28 from being damaged when they come into contact with the tip side opening 78A. The tip side opening 78A is an example of a tip side opening of the present invention.

[0063] A tubular metal fitting 77 is fixed to the inner peripheral surface of the tip side of the cable main body 76, and a connecting pipe 78 is fixed to the inner peripheral surface of this metal fitting 77 via an O-ring 79. As will be described in detail later, the connecting pipe 78 is connected to the magnetic coupling 102 via a connecting beam 100 and a bearing support member 96. The above is the configuration of the external cable 72, but this configuration is one example. For example, as another configuration of the external cable 72, a configuration in which a tip side opening 78A is formed on the tip side of the cable main body 76 without providing the connecting pipe 78 is also applicable.

[0064] Next, a configuration for inserting and arranging the first signal cable 26 and the second signal cable 27 inside the operation unit main body 22 will be described.

[0065] As shown in FIG. 3 , the case 74 is generally tubular and parallel to the insertion axis Ax, and is formed with a diameter smaller than the inner diameter of the operation unit main body 22. The case 74 is housed inside the operation unit main body 22. The case 74 is supported in the internal space of the operation unit main body 22 by the outer tube 32, the external cable 72, and the like. The distal end side of the case 74 is connected to the proximal end of the outer tube 32. As a result, when the outer tube 30 is rotated in the axial direction B relative to the operation unit main body 22, this rotational force is transmitted to the distal optical system 40, the outer tube 32, and the case 74. As a result, the case 74 is rotated in the same direction as the outer tube 30. The case 74 is an example of a case of the present invention.

[0066] The base end side of the inner tube 34 and the base end side of the first signal cable 26 are disposed inside the case 74. Furthermore, a partition wall 74a perpendicular to the insertion axis Ax is provided inside the case 74, for example, in the opening on the base end side of the case 74. The partition wall 74a closes the opening on the base end side of the case 74. The partition wall 74a is an example of a partition wall of the present invention.

[0067] Furthermore, a cylindrical portion 74b parallel to the insertion axis Ax is provided on the base end side of the case 74. The cylindrical portion 74b is formed to have the same diameter as the case 74, but may be formed to have a diameter different from that of the case 74. The cylindrical portion 74b may also be formed integrally with the case 74. In this case, the base end side of the case 74 functions as the cylindrical portion 74b. Inside the case 74 and the cylindrical portion 74b, in addition to a part of the connecting portion 84 described below, the tip side of the second signal cable 27 is arranged.

[0068] 4 is a cross-sectional view of the outer cylinder 32 and the case 74. As shown in FIG. 4, an enclosed space 80 (airtight space) is formed inside the outer cylinder 32 and the case 74, and the inner cylinder 34, the imaging unit 60 (see FIG. 2), the first signal cable 26, etc. are disposed in the enclosed space 80. The distal end side of the enclosed space 80 is defined by the distal optical system 40. The proximal end side of the enclosed space 80 is defined by the partition wall 74a. This improves the moisture resistance of the camera unit 24 and prevents fogging.

[0069] 5 is an enlarged cross-sectional view of the case 74 and the cylindrical portion 74b. As shown in FIGS. 3 to 5, the case 74 and the cylindrical portion 74b are provided with the partition wall 74a, the airtight connector 82, and the connecting portion 84.

[0070] The airtight connector 82 is provided to be rotatable relative to the partition wall 74a in the direction B around the axis so as to penetrate between the inside and outside of the sealed space 80. The airtight connector 82 electrically connects the base end side of the first signal cable 26 inside the case 74 (inside the sealed space 80) and the tip side of the second signal cable 27 inside the tubular portion 74b (outside the sealed space 80). This allows the first signal cable 26 and the second signal cable 27 to be inserted and disposed inside the operation unit main body 22. Note that if the first signal cable 26 and the second signal cable 27 are torsionally deformable in the direction B around the axis, for example, if the first signal cable 26 and the second signal cable 27 are each made up of a plurality of separate wires, the airtight connector 82 may be fixed to the partition wall 74a.

[0071] The coupling portion 84 is provided inside the case 74 and the cylindrical portion 74b so as to be rotatable relative to the case 74 and the cylindrical portion 74b in the direction around the axis B. The first signal cable 26 and the second signal cable 27 are inserted inside the coupling portion 84. The coupling portion 84 magnetically couples (connects) the base end side of the inner tube 34 inside the case 74 (inside the sealed space 80) to the tip end side of the external cable 72 (see FIG. 3 ) outside the sealed space 80, with the partition wall 74a sandwiched therebetween.

[0072] The coupling portion 84 has a connecting member 90, a bearing support member 92, and a bearing 94. In addition to the above members, the coupling portion 84 also has a bearing support member 96, a bearing 98, a coupling beam 100, and a magnetic coupling 102.

[0073] The connecting member 90 and the bearing receiving member 92 are provided inside the case 74 (inside the sealed space 80) and are formed in a generally tubular shape parallel to the insertion axis Ax. The first signal cable 26 is inserted through the connecting member 90 and the bearing receiving member 92.

[0074] The connecting member 90 connects the base end side of the inner tube 34 and the tip side of the bearing receiving member 92 inside the case 74 (inside the sealed space 80). As a result, the tip side of the bearing receiving member 92 is connected to the base end side of the inner tube 34 via the connecting member 90.

[0075] The bearing support member 92 has its tip end connected to the connecting member 90 as described above, and its base end fixed to the first magnet 103 of the magnetic coupling 102. A bearing 94 that is inscribed in the case 74 is fixed to the outer circumferential surface of the bearing support member 92. This allows the bearing support member 92 and the first magnet 103 to be held within the case 74 so as to be rotatable relative to the case 74 in the direction B around the axis. The bearing 94 may be any of various known radial bearings, such as a ball bearing or a roller bearing.

[0076] Furthermore, the rolling elements (balls or rollers) that are components of the bearing 94 are made of a non-magnetic material. By making the rolling elements of the bearing 94 from a non-magnetic material, it is possible to prevent the magnetic force of the first magnet 103 from acting on the rolling elements. As a result, the bearing support member 92 and the first magnet 103 can rotate smoothly relative to the case 74. Examples of non-magnetic materials include ceramics, non-magnetic metals (e.g., stainless steel), and resins. It should be noted that not only the rolling elements but also other components of the bearing 94 (inner ring, outer ring, cage) may be made of a non-magnetic material.

[0077] The bearing receiving member 96 is provided inside the cylindrical portion 74b (outside the sealed space 80). The bearing receiving member 96 is formed in a generally tubular shape parallel to the insertion axis Ax, and the second signal cable 27 is inserted inside the bearing receiving member 96.

[0078] The bearing support member 96 has a tip end fixed to the second magnet 104 of the magnetic coupling 102 inside the cylindrical portion 74b, and a base end connected to the connecting beam 100. A bearing 98 inscribed in the cylindrical portion 74b is fixed to the outer circumferential surface of the bearing support member 96. This allows the bearing support member 96 and the second magnet 104 to be held within the cylindrical portion 74b so as to be rotatable relative to the cylindrical portion 74b in the direction B around the axis. As with the bearing 94, various known radial bearings may be used for the bearing 98.

[0079] Furthermore, the rolling elements (balls or rollers) that constitute the bearing 98 are also made of a non-magnetic material, just like the bearing 94. By making the rolling elements of the bearing 98 out of a non-magnetic material, it is possible to prevent the magnetic force of the second magnet 104 from acting on the rolling elements. As a result, the bearing support member 96 and the second magnet 104 can rotate smoothly relative to the cylindrical portion 74b. Examples of non-magnetic materials include ceramics, non-magnetic metals (e.g., stainless steel), and resins. It should be noted that not only the rolling elements but also other constituent members of the bearing 98 (inner ring, outer ring, cage) may be made of a non-magnetic material.

[0080] Based on the above configuration, the endoscope 10 of the embodiment includes an outer tube 32 that constitutes the insertion portion 20, a tubular case 74 connected to the base end side of the outer tube 32, a distal end optical system 40 that is provided at the distal end of the outer tube 74 and that defines the distal end side of a sealed space 80 formed inside the outer tube 32 and the case 74, a partition wall 74a that is provided inside the case 74 and is perpendicular to the insertion axis Ax of the insertion portion 20 and defines the proximal end side of the sealed space 80, and a partition wall 74b that is inserted inside the outer tube 32 and is parallel to the insertion axis Ax with respect to the outer tube 32. The magnetic coupling 102 includes an inner cylinder 34 that is rotatable relative to the case 74 in the axial direction B, an imaging unit 60 that is provided at the tip of the inner cylinder 34 and captures an image of light that has passed through the tip optical system 40, and a magnetic coupling 102 that has a first magnet 103 provided within the sealed space 80 and a second magnet 104 provided outside the sealed space 80 with a partition wall 74a in between, the first magnet 103 being connected to the base end side of the inner cylinder 34, and the magnetic coupling 102 and the case 74 are configured to be rotatable relative to the case 74 in the axial direction B. The rolling element of a bearing 94 that supports the first magnet 103 rotatably relative to the case 74, and the rolling element of a bearing 98 that supports the secondary magnet 104 rotatably relative to the cylindrical portion 74b are each made of a non-magnetic material.

[0081] As shown in FIG. 3 , the connecting beam 100 is configured as a beam extending in the axial direction of the insertion axis Ax within the light guide insertion space 70 (described later). The connecting beam 100 has a ring portion 100a at its distal end and a ring portion 100b at its proximal end, with the ring portion 100a fitted onto the proximal end of the bearing support member 96 and the ring portion 100b fitted onto the distal end of the metal fitting 77. As a result, the proximal end of the second magnet 104 is connected via the bearing support member 96 to the distal end of the external cable 72 via the metal fitting 77 via the connecting beam 100. In other words, the distal end of the external cable 72 is connected to the proximal end of the second magnet 104 via the connecting beam 100. The connecting beam 100 is an example of a connecting member of the present invention.

[0082] The magnetic coupling 102 is composed of a first magnet 103 provided inside the case 74 (inside the sealed space 80) with the partition wall 74a sandwiched therebetween, and a second magnet 104 provided inside the cylindrical portion 74b (outside the sealed space 80). The magnetic coupling 102 is a magnetic coupling member that magnetically couples the bearing support member 92 (inner cylinder 34) and the bearing support member 96 (external cable 72), and is an example of the magnetic coupling of the present invention. The first magnet 103 is an example of the first magnet of the present invention, and the second magnet 104 is an example of the second magnet of the present invention.

[0083] Fig. 6 is a front view of the first magnet 103 and the second magnet 104 as seen from the partition wall 74a side. Fig. 7 is a side view of the first magnet 103 and the second magnet 104. As shown in Fig. 6, the first magnet 103 and the second magnet 104 have a disk shape (ring shape) parallel to the partition wall 74a (perpendicular to the insertion axis Ax). An insertion hole 103a through which the first signal cable 26 is inserted is formed in the center of the first magnet 103, and an insertion hole 104a through which the second signal cable 27 is inserted is formed in the center of the second magnet 104. The first magnet 103 and the second magnet 104 are so-called single-sided multi-pole magnets, and multiple pairs of N poles and S poles are formed at equal angular intervals around the axis on the surface facing the partition wall 74a.

[0084] The first magnet 103 and the second magnet 104 are not limited to a single-sided multi-pole type, but may be a double-sided multi-pole type, and the number of poles is not particularly limited as long as it is 2 or more. The shape of the first magnet 103 and the second magnet 104 is not limited to a disk shape, but may be any shape, such as a polygonal shape parallel to the partition wall 74a.

[0085] 7, the first magnet 103 and the second magnet 104 are arranged with the partition wall 74a sandwiched between them so that the individual north poles of one of them face the individual south poles of the other and the individual south poles of one face the individual north poles of the other. As a result, the first magnet 103 and the second magnet 104 are magnetically coupled in the thrust direction of the insertion axis Ax (a direction parallel to the insertion axis Ax) with the partition wall 74a sandwiched between them. As a result, the inner tube 34 and the external cable 72 are magnetically coupled via the magnetic coupling 102.

[0086] By magnetically coupling the inner tube 34 and the external cable 72 with the magnetic coupling 102, torque (static torque, rotational torque) can be transmitted from the external cable 72 to the inner tube 34. As a result, when the practitioner rotates the outer tube 30 using the knob 36, the inner tube 34 (the proximal optical system 50 and the imaging unit 60) is prevented from rotating (co-rotating) together with the outer tube 32 in the direction around the axis B; in other words, the magnetic coupling 102 maintains the orientation of the inner tube 34 in the direction around the axis B.

[0087] Next, a configuration for inserting and arranging the light guide 28 inside the operation portion main body 22 will be described.

[0088] 3, a fixing member 110 is disposed inside the operation unit main body 22. The fixing member 110 has a fixing portion 112 that fixes a part of the light guide 28 in the longitudinal direction.

[0089] Fig. 8 is a diagram showing the internal structure of the operation unit main body 22, illustrating the configuration of the fixed member 110. As shown in Fig. 8, the fixed member 110 is configured as a ring-shaped member, and is connected to the outer peripheral surface of the case 74, which is connected to the base end side of the outer tube 32 (see Fig. 3). As a result, the fixed member 110 is connected to the outer tube 32 via the case 74, and rotates integrally with the outer tube 32 and the case 74 in the direction B around the axis. The fixed member 110 is an example of a fixed member of the present invention.

[0090] The fixing member 110 has a fixing portion 112 at a portion of its circumference. The fixing portion 112 is configured as a tubular member into which the light guide 28 can be inserted, and is fixed by a screw 113 in a gap between a pair of flanges 111, 111 protruding from the outer circumferential surface of the fixing member 110. As a result, the fixing portion 112 is arranged so that its central axis C is approximately parallel to the insertion axis Ax. By inserting the light guide 28 into the fixing portion 112, a portion of the light guide 28 in the longitudinal direction is fixed by the fixing portion 112. The fixing portion 112 is an example of a fixing portion of the present invention.

[0091] Although the present embodiment has been described with reference to a ring-shaped member as the fixing member 110, the shape of the fixing member 110 is not particularly limited as long as it is rotatable integrally with the outer tube 32 in the axial direction B. Similarly, the present embodiment has been described with reference to a tubular member as the fixing portion 112, but the shape of the fixing portion 112 is not particularly limited as long as it is capable of fixing a portion of the light guide 28 in the longitudinal direction. Furthermore, the present embodiment has been described with reference to a configuration in which the fixing member 110 and the fixing portion 112 are separate bodies, but the fixing member 110 and the fixing portion 112 may be integrally configured. Furthermore, the present embodiment has been described with reference to a configuration in which the fixing member 110 is connected to the base end side of the outer tube 32 via the case 74, but the fixing member 110 may be directly connected to the base end side of the outer tube 32.

[0092] When a portion of light guide 28 is fixed by fixing portion 112 inside operation unit main body 22 as in this example, light guide 28 is divided into light guide 28 (hereinafter referred to as "light guide 28A") that is arranged facing the distal end side (insertion unit 20 side) across fixed portion 112, and light guide 28 (hereinafter referred to as "light guide 28B") that is arranged facing the proximal end side (external cable 72 side) across fixed portion 112. Note that this example will be described taking as an example a configuration in which one light guide 28 is divided into light guide 28A and light guide 28B across fixed portion 112, but a configuration in which two light guides 28A and 28B are used and the proximal end side of light guide 28A and the distal end side of light guide 28B are connected via fixed portion 112 is also applicable.

[0093] Here, the light guide 28A is fixed to the inner circumferential surface of the outer tube 30 and the outer circumferential surface of the outer cylinder 32, so when the outer tube 30 and the outer cylinder 32 are rotated, the light guide 28A rotates integrally with the outer tube 30 and the outer cylinder 32 together with the fixing member 110 (fixing portion 112). As a result, the light guide 28A is not rubbed against the inner circumferential surface of the outer tube 30 and the outer circumferential surface of the outer cylinder 32 during rotation, preventing damage caused by rubbing.

[0094] Meanwhile, the light guide 28B is inserted and disposed in a light guide insertion space 70 formed between the fixed part 112 and the distal end opening 78A inside the operation unit main body 22 (see FIG. 3). When the fixed member 110 is rotated in the direction B about the axis by the knob 36, the light guide 28B is inserted and disposed in the light guide insertion space 70 without applying tension to the light guide 28B. Hereinafter, the insertion and arrangement of the light guide 28B in the light guide insertion space 70 will be specifically described.

[0095] 9, 10, and 11 are explanatory diagrams showing the insertion and arrangement forms (hereinafter also referred to as "postures") of the light guide 28B within the light guide insertion space 70. That is, FIG. 9 shows the posture of the light guide 28B when the fixed portion 112 is located at the center position of the rotation range of the fixed member 110, which will be described later. FIG. 10 shows the posture of the light guide 28B when the fixed member 110 (fixed portion 112) has rotated leftward (counterclockwise) when the fixed member 110 is viewed from the base end side of the operation unit main body 22. FIG. 11 shows the posture of the light guide 28B when the fixed member 110 (fixed portion 112) has rotated rightward (clockwise) when the fixed member 110 is viewed from the base end side of the operation unit main body 22.

[0096] As shown in Figures 9 to 11, the posture of the light guide 28B within the light guide insertion space 70 differs depending on the rotational position of the fixing portion 112, but the light guide 28B remains in a state where it is not under tension within the light guide insertion space 70 regardless of the posture.

[0097] In order for the light guide 28B to be maintained in this bent state, the light guide 28B has a length that allows the bent state to be maintained between the fixed portion 112 and the distal end opening 78A in the direction of the insertion axis Ax within the rotation range of the fixed member 110. In other words, as shown in the explanatory diagram of FIG. 12 that shows the length of the light guide 28B within the light guide insertion space 70, the light guide 28B inserted and disposed within the light guide insertion space 70 has a length that is longer than the linear distance L connecting the base end 112A of the fixed portion 112 and the center 78B of the distal end opening 78A. This allows the light guide 28B to be maintained in a bent state within the light guide insertion space 70 within the rotation range of the fixed member 110. As a result, no twisting occurs in the light guide 28B within the rotation range of the fixed member 110.

[0098] 9 to 11, the connecting beam 100, which is disposed in the light guide insertion space 70 together with the light guide 28B, is formed in the shape of a beam extending in the insertion axis Ax direction in the light guide insertion space 70. This makes it possible to reduce the proportion (space) occupied by the connecting beam 100 in the light guide insertion space 70. As a result, the light guide 28B can change its position in a bent state without being hindered by the connecting beam 100. Note that it is preferable that the surface of the connecting beam 100 has a rounded shape. This makes it possible to prevent the light guide 28B from being damaged when it comes into contact with the connecting beam 100.

[0099] Here, "a state without tension" means that the additional tension (maximum tension) applied to the light guide 28B in association with the rotation of the fixing member 110 is approximately 0 (zero). In other words, if the initial tension (including tension due to the weight of the light guide 28B) generated in the light guide 28B before the rotation of the fixing member 110 is T0 and the additional tension applied to the light guide 28B after the rotation of the fixing member 110 is T1, then a total tension of T0 + T1 acts on the light guide 28B after the rotation of the fixing member 110. In the oblique endoscope 10 of this embodiment, the light guide 28B is accommodated in the light guide insertion space 70 in a bent state, and the additional tension T1 applied to the light guide 28B after the rotation of the fixing member 110 is approximately 0. Therefore, the total tension T0 + T1 generated in the light guide 28B before and after the rotation of the fixing member 110 is approximately constant, preventing excessive tension from being generated in the light guide 28B. The additional tension T1 applied to the light guide 28B after the rotation of the fixing member 110 is not necessarily limited to 0 (zero), but may be an additional tension T1 of a magnitude that does not induce co-rotation of the external cable 72.

[0100] Furthermore, in the oblique endoscope 10 of this embodiment, the light guide 28B is accommodated in the light guide insertion space 70 in a bent state, and within the rotation range of the fixing member 110, excessive torsional force is not applied to the light guide 28B when the fixing member 110 is rotated. In other words, even when the fixing member 110 is rotated, large tension (total tension) and torsional force are not applied to the light guide 28B, and damage (cutting, etc.) to the light guide 28B can be prevented.

[0101] In this example, the light guide 28B is inserted and disposed in a wave-shaped bent state within the light guide insertion space 70 as an example of a configuration in which tension is not applied to the light guide 28B. However, it is also possible to insert and dispose the light guide 28B in a loop-shaped state within the light guide insertion space 70. However, because the light guide 28B is generally a strong member, if the light guide 28B is disposed in a loop-shaped state, excessive tension is applied to the light guide 28B, which may result in damage to the light guide 28B. This problem can be solved by increasing the diameter of the loop to reduce the tension, but this is undesirable because it increases the size of the operation unit main body 22. From this perspective, it is preferable to insert and dispose the light guide 28B in a wave-shaped bent state within the light guide insertion space 70. This prevents damage to the light guide 28B and enables the operation unit main body 22 to have a smaller diameter.

[0102] 3, in the oblique endoscope 10 of this example, the fixing portion 112 of the fixing member 110 is disposed closer to the distal end in the direction of the insertion axis Ax than the proximal side surface 96a of the bearing receiving member 96. This allows the length of the light guide 28B in the light guide insertion space 70 to be longer than the length of the second signal cable 27. As a result, it is possible to reduce stress applied to the light guide 28B when the fixing member 110 rotates. Note that, as another embodiment, in a configuration in which the second magnet 104 and the connecting beam 100 are connected without using the bearing receiving member 96, the fixing portion 112 only needs to be disposed closer to the distal end in the direction of the insertion axis Ax than the insertion hole 104a (see FIG. 5) formed in the second magnet 104. As a result, the same effects as those described above can be obtained.

[0103] 9 to 11 rotates integrally with the case 74 when the knob 36 is rotated, but if the fixed member 110 is allowed to rotate freely (infinitely), this is not preferable because the light guide 28B would become entangled in the connecting beam 100. Therefore, the oblique view mirror 10 of this example is provided with a rotation stopper 120 (see FIG. 3) that restricts the range of rotation of the fixed member 110 in the direction B around the axis.

[0104] Fig. 3 shows an example of a rotation stopper 120. As shown in Fig. 3, the rotation stopper 120 has a stopper groove 122 formed on the operation unit main body 22 side and a stopper pin 124 protruding on the knob 36 side. The rotation stopper 120 is an example of a rotation stopper of the present invention.

[0105] FIG. 13 is a schematic diagram showing the configuration of the rotation stopper 120 when the knob 36 is viewed from the base end side of the operation unit main body 22. As shown in FIG. 13, the stopper groove 122 is formed on the outer peripheral surface of the distal end side of the operation unit main body 22. The stopper groove 122 has a groove portion 122a, a wall portion 122b formed on one end side of the groove portion 122a, and a wall portion 122c formed on the other end side of the groove portion 122a. The groove portion 122a is formed in an arc shape centered on the central axis D of rotation of the knob 36 relative to the operation unit main body 22 on a plane perpendicular to the insertion axis Ax. The wall portions 122b and 122c are each formed as stopper surfaces protruding in a direction normal to the groove portion 122a. Meanwhile, the stopper pin 124 is provided on the inner peripheral surface of the knob 36 and protrudes toward the central axis D of rotation and is inserted into the groove portion 122a.

[0106] Below, we will explain the positional relationship between the rotation stopper 120 (stopper pin 124) shown in Figure 13 and the fixed member 110 (fixed portion 112) shown in Figures 9 to 11, and will also explain an example of the rotation range of the fixed member 110 that is regulated by the rotation stopper 120.

[0107] As shown in FIG. 9 , when the fixed portion 112 is located at the center of the rotation range of the fixed member 110, the stopper pin 124 is located at the center of the groove 122a in the longitudinal direction E, as indicated by the solid line in FIG. 13 . Thereafter, when the knob 36 is rotated counterclockwise F, the stopper pin 124 moves in the same direction along the groove 122a, and the fixed portion 112 rotates counterclockwise from the position shown in FIG. 9 to the position shown in FIG. 10 . When the stopper pin 124 abuts against the wall portion 122b, the fixed portion 112 stops at the position shown in FIG. 10 . This restricts the counterclockwise rotation of the fixed member 110. When the knob 36 is rotated clockwise G from this state, the stopper pin 124 moves in the same direction along the groove 122a, and the fixed portion 112 rotates clockwise from the position shown in FIG. 10 to the position shown in FIG. 11 . Then, when the stopper pin 124 abuts against the wall portion 122c, the fixed portion 112 stops at the position shown in FIG. 11. This restricts the clockwise rotation of the fixed member 110. As described above, the rotation range of the fixed member 110 is restricted (defined) by the rotation stopper 120. By restricting the rotation range of the fixed member 110 in this manner, problems such as the light guide 28B becoming entangled in the connecting beam 100 can be resolved.

[0108] 13, the range of rotation of fixing member 110 restricted by rotation stopper 120 is represented by angle θ. From the viewpoint of preventing the above-mentioned entanglement, angle θ is preferably at least 350 degrees or less, and may be 300 degrees or less, or may be 200 degrees or less. Furthermore, angle θ may be set depending on the type of oblique viewing mirror.

[0109] In this example, the rotation stopper 120 is described as having a stopper groove 122 formed on the operation unit main body 22 side and a stopper pin 124 protruding from the knob 36 side, but any configuration that can regulate the rotation range of the fixed member 110 is applicable. For example, the rotation stopper 120 can also be configured as having a stopper groove 122 formed on the inner peripheral surface of the operation unit main body 22 and a stopper pin 124 protruding from the outer peripheral surface of the case 74.

[0110] On the other hand, the light guide 28B has a length that allows the light guide 28B to maintain a bent state between the fixed portion 112 and the distal end opening 78A in the direction of the insertion axis Ax within the rotation range (angle θ) of the fixing member 110. As an example, the length of the light guide 28B between the fixed portion 112 and the distal end opening 78A is preferably 1.2 to 1.5 times the linear distance L connecting the base end 112A of the fixing portion 112 and the center 78B of the distal end opening 78A, as shown in Fig. 12. This allows the light guide 28B to maintain a wave-shaped bent state within the light guide insertion space 70 without being subjected to tension or bent into a loop within the rotation range (angle θ) of the fixing member 110.

[0111] Next, the operation of the oblique endoscope 10 of this embodiment will be described.

[0112] In the oblique endoscope 10 of this embodiment, a practitioner holds the operation unit main body 22 and inserts the insertion section 20 into the patient's body. Thereafter, to change the direction of view, the practitioner rotates the knob 36 in the direction around the axis B. This causes the outer tube 30 and the outer cylinder 32, which rotate integrally with the knob 36, to rotate in the same direction, thereby enabling the direction of view to be directed in the desired direction. Furthermore, when the practitioner rotates the outer tube 30 using the knob 36, the inner cylinder 34 (the proximal optical system 50 and the imaging unit 60) is prevented from rotating (co-rotating) in the direction around the axis B together with the outer cylinder 32. In other words, because the magnetic coupling 102 maintains the orientation of the inner cylinder 34 in the direction around the axis B, rotation of the observation image observed on the monitor 16 is prevented even when the direction of view is changed, improving the operability of the oblique endoscope 10.

[0113] Furthermore, in the oblique endoscope 10 of this embodiment, when the knob 36 is rotated, the light guide 28A on the distal side relative to the fixed portion 112 rotates integrally with the outer tube 30 and the outer cylinder 32 together with the fixed member 110 (fixed portion 112). On the other hand, the light guide 28B on the proximal side relative to the fixed portion 112 remains bent within the light guide insertion space 70 even when the fixed member 110 rotates. This allows the light guide 28B to remain inserted into the external cable 72 from the distal opening 78A without being twisted. As a result, when the practitioner holding the operation unit main body 22 rotates the outer tube 30, the practitioner does not receive a reaction force due to torsion from the light guide 28B and the external cable 72, making it easier to perform an operation to change the field of view.

[0114] As described above, the oblique endoscope 10 of this embodiment has a configuration in which the fixing member 110, which rotates in the direction B about the axis together with the knob 36, is disposed inside the operation unit main body 22, the fixing portion 112 of the fixing member 110 fixes a portion of the longitudinal direction of the light guide 28, the light guide insertion space 70 is formed inside the operation unit main body 22, and the light guide 28B is inserted and disposed in the light guide insertion space 70 so that no tension is applied to the light guide 28B between the fixing portion 112 and the tip-end opening 78A even when the fixing member 110 is rotated in the direction B about the axis by the knob 36. This results in a simple structure and makes it possible to prevent co-rotation of the external cable 72.

[0115] Furthermore, in the oblique endoscope 10 of this embodiment, the operation unit main body 22 is easily held in the optimal observation direction position because no reaction force is applied to the operation unit main body 22 due to twisting of the light guide 28 and the external cable 72. As a result, the operability of the oblique endoscope 10 is significantly improved.

[0116] Other Embodiments In the above embodiment, the first signal cable 26 and the second signal cable 27 are described as multi-core cables each including a plurality of element wires (signal wires), a shield conductor, and an outer sheath. However, this is not limiting. For example, in another embodiment, the first signal cable 26 and the second signal cable 27 may each be configured with a plurality of separate element wires. In this case, even if a torsional force (torque) acts on the first signal cable 26 and the second signal cable 27, the torque can be reduced, thereby preventing breakage of the first signal cable 26 and the second signal cable 27. Furthermore, if the second signal cable 27 is configured with the above element wires, the element wires may come into contact with the periphery of the tip-side opening 78A shown in FIG. 3. However, since the periphery of the tip-side opening 78A is formed in a rounded shape, breakage of the element wires can be prevented.

[0117] 〔others〕 In the above embodiment, the annular knob 36 was used as an example of a rotation operating member, but it is also possible to use a member formed on part of the outer surface of the outer tube 30 that is easy for the practitioner's fingers to grip, such as a convex member or a sawtooth member.

[0118] Although examples of the endoscope according to the present invention have been described above, the present invention may be improved or modified in several ways without departing from the gist of the present invention. [Explanation of symbols]

[0119] 10 Oblique scope 12 Endoscopy System 14 Processor unit 16 monitors 18 Light source device 20 Insertion section 22 Operation unit main body 24 Camera Unit 26 First signal cable 27 Second signal cable 28 Light Guide 28A Light Guide 28B Light Guide 28C Light output end 30 Exterior pipe 31 Space 32 outer cylinder 34 Inner cylinder 36 Knob 38 Seal ring 40 Advanced optical system 42 Tip body 44 Front lens barrel 45 Cylindrical part 46 Coverslips 48a Objective Lens 48b Prism 48c lens 50 Proximal optical system 52 Base end barrel 54 Holder 55 Prism 56 Lens 60 Imaging unit 64 image sensor 66 Circuit Board 68 Connector 70 Light guide insertion space 72 External Cable 74 cases 76 Cable body 78 Connecting Pipe 78A Tip side opening 77 Metal fittings 79 O-ring 80 Closed space 82 Airtight Connector 84 Connecting part 90 Connecting member 92 Bearing support member 94 bearings 96 Bearing support member 96a Proximal side 98 Bearings 100 Connecting beam 100a ring part 100b Ring part 102 Magnetic Coupling 103 First Magnet 103a Insertion hole 104 Second Magnet 104a Insertion hole 110 Fixing member 111 flange 112 Fixed part 113 Screw 120 rotation stopper 122 Stopper groove 122a Groove 122b Wall section 122c wall 124 Stopper pin Ax Insertion axis OA optical axis B axis direction C center axis D Rotational axis E Lengthwise F Counterclockwise G Clockwise L straight line distance

Claims

1. an outer tube that constitutes the insertion portion; a tubular operating portion main body connected to a base end side of the outer tube and supporting the outer tube rotatably in a direction around the axis of the insertion portion; an annular rotation operation member fixed to a base end side of the outer tube and configured to rotate the outer tube relative to the operation portion main body in a direction around the axis; an outer cylinder inserted into the outer tube and rotatable integrally with the outer tube; a tip optical system provided on the tip side of the outer tube; a flexible light guide disposed in a space between the outer tube and the external cylinder and having a light emitting end on a tip side of the outer tube; an inner cylinder that is inserted into the outer cylinder and is rotatable relative to the outer cylinder in a direction around the axis; an imaging unit provided at the tip side of the inner tube and configured to capture an image of light that has passed through the tip optical system; an external cable connected to the base end side of the operation unit body, the light guide being inserted into the cable from a tip end side opening; a fixing member disposed inside the operation unit body, the fixing member having a fixing portion that fixes a part of the light guide in the longitudinal direction and that is rotatable around the axis integrally with the rotation operation member; Equipped with a light guide insertion space is formed between the fixed portion and the distal end opening inside the operation portion body, When the fixed member is rotated in the axial direction by the rotation operation member, the light guide is inserted and disposed in the light guide insertion space in a state where no tension is applied to the light guide between the fixed portion and the tip-end side opening. Endoscope.

2. an outer tube that constitutes the insertion portion; a tubular operating portion main body connected to a base end side of the outer tube and supporting the outer tube rotatably in a direction around the axis of the insertion portion; an annular rotation operation member fixed to a base end side of the outer tube and configured to rotate the outer tube relative to the operation portion main body in a direction around the axis; an outer cylinder inserted into the outer tube and rotatable integrally with the outer tube; a tip optical system provided on the tip side of the outer tube; a flexible light guide disposed in a space between the outer tube and the external cylinder and having a light emitting end on a tip side of the outer tube; an inner cylinder that is inserted into the outer cylinder and is rotatable relative to the outer cylinder in a direction around the axis; an imaging unit provided at the tip side of the inner tube and configured to capture an image of light that has passed through the tip optical system; an external cable connected to the base end side of the operation unit body, the light guide being inserted into the cable from a tip end side opening; a fixing member disposed inside the operation unit body, the fixing member having a fixing portion that fixes a part of the light guide in the longitudinal direction and that is rotatable around the axis integrally with the rotation operation member; Equipped with a light guide insertion space is formed between the fixed portion and the distal end opening inside the operation portion body, the light guide inserted and disposed in the light guide insertion space has a length longer than a linear distance connecting a base end of the fixing portion and a center of the tip side opening; Endoscope.

3. the fixing member is connected to a base end side of the outer cylinder and is rotatable around the axis integrally with the outer cylinder; The endoscope according to claim 1 or 2.

4. the fixing member is a ring-shaped member connected to a base end side of the outer cylinder, and has the fixing portion at a part in a circumferential direction of the ring-shaped member; The endoscope according to claim 3 .

5. a rotation stopper that restricts the rotation range of the fixed member around the axis; The endoscope according to any one of claims 1 to 4.

6. the light guide has a length that allows the light guide to be maintained in a deflected state between the fixing portion and the distal end opening in the axial direction of the insertion portion within the rotation range caused by the rotation stopper. The endoscope according to claim 5.

7. the rotary operation member is provided on the distal end side of the operation unit body and is configured as an annular member rotatable in the direction around the axis relative to the operation unit body; The endoscope according to any one of claims 1 to 6.

8. a signal cable connected to the imaging unit and inserted through the inner cylinder; The signal cable is inserted into the external cable from the tip-side opening. The endoscope according to any one of claims 1 to 7.

9. The signal cable is a plurality of separate wires. The endoscope according to claim 8.

10. a tubular case connected to a base end side of the outer cylinder inside the operation portion main body and disposed on a distal end side of the insertion portion in the axial direction relative to the light guide insertion space; a partition wall provided inside the case and perpendicular to the insertion axis of the insertion portion; a magnetic coupling including a first magnet provided on a distal end side in the axial direction with the partition wall interposed therebetween and a second magnet provided on a proximal end side in the axial direction, the first magnet being connected to the proximal end side of the inner cylinder; Equipped with The magnetic coupling and the case are relatively rotatable in the direction around the axis. The endoscope according to any one of claims 1 to 9.

11. a distal end side of the external cable is connected to a proximal end side of the second magnet via a beam-shaped connecting member extending in the axial direction within the light guide insertion space; The endoscope according to claim 10.

12. a signal cable connected to the imaging unit and inserted into the inner cylinder; the first magnet and the second magnet are formed in a disk shape perpendicular to the insertion axis, and each has an insertion hole through which the signal cable is inserted; The endoscope according to claim 10 or 11.

13. the fixing member is fixed to an outer peripheral surface of the case, the fixing portion of the fixing member is disposed on a tip side in the axial direction relative to the insertion hole formed in the second magnet, The endoscope according to claim 12.

14. The peripheral edge of the tip-side opening of the external cable is formed into an R-surface shape. The endoscope according to any one of claims 1 to 13.

15. a proximal optical system provided at a distal end side of the inner tube and guiding light that has passed through the distal optical system to the imaging unit; the imaging unit includes an imaging element that captures an image of light incident through the proximal optical system and outputs an imaging signal to a signal cable; the distal end optical system is rotatable in a direction around the axis relative to the proximal end optical system and the imaging element; The endoscope according to any one of claims 1 to 14.

Images