Camera module and endoscope

Abstract

To provide a camera module capable of suppressing disconnection due to twisting of a cable.SOLUTION: An endoscopic camera module 20 comprises: an imaging module; a cable 28 connected to the imaging module, and having a plurality of signal lines 28a and covering members (a shield 28c and an outer skin 28d) that cover the signal lines 28a; and at least one fixing member 35 provided on an outer periphery of the covering members at a connection part between the cable 28 and the imaging module, and crimping the cable 28. When a diameter of the cable 28 is denoted as d and a volume of the fixing member 35 is denoted as v, V / d2>0.35 is satisfied.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present invention relates to a camera module and an endoscope. [Background technology]

[0002] Patent Document 1 describes an endoscopic imaging device that has a lens barrel with an imaging lens inside, an imaging element that receives light that has passed through the imaging lens and performs photoelectric conversion, a holder that holds the lens barrel, a cable that is electrically connected to the imaging element and has an outer sheath that forms the outer periphery, and a connecting member that connects the holder and the cable, wherein the cable is covered with a first tube and a second tube that overlap each other, the tip of the first tube and the tip of the second tube are housed in the connecting member, and the rear end of the first tube is closer to the connecting member than the rear end of the second tube. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2023-151016 Summary of the Invention

[0004] One embodiment of the technique of the present disclosure provides a camera module and an endoscope that can prevent cable breakage due to twisting. [Means for solving the problem]

[0005] (1) A camera module for an endoscope, An imaging module; a cable connected to the imaging module, the cable including a plurality of conductors and a covering member covering the plurality of conductors; at least one fixing member provided on an outer periphery of the covering member at a connection portion between the cable and the imaging module, and configured to crimp the cable; Equipped with When the diameter of the cable is d and the volume of the fixing member is V, V / d2 > 0.35 is satisfied. Camera module.

[0006] (2) The camera module according to (1), The fixing member is covered with a cured adhesive and is fixed to the housing of the imaging module by the adhesive. Camera module.

[0007] (3) The camera module according to (1) or (2), Satisfying V / d2 > 0.4, Camera module.

[0008] (4) The camera module according to any one of (1) to (3), When the diameter of the circumscribed circle of the fixing member caulked with the cable is OD, OD > d is satisfied. Camera module.

[0009] (5) The camera module according to any one of (1) to (4), The covering member includes a shield covering the plurality of conductors and an outer skin covering the shield. When the diameter of the inscribed circle of the fixing member caulked with the cable is ID and the diameter of the outer peripheral portion of the shield is sd, ID < sd is satisfied. Camera module.

[0010] (6) The camera module according to any one of (1) to (5), The fixing member is an annular member. Camera module.

[0011] (7) The camera module according to (6), The fixing member is a metal ring. Camera module.

[0012] (8) The camera module according to any one of (1) to (7), The diameter of the cable is 2.5 mm or less. Camera module.

[0013] (9) The camera module according to any one of (1) to (8), the fixing member has a shape that is substantially point-symmetrical with respect to the center of the cable when viewed in the axial direction of the cable; Camera module.

[0014] (10) The camera module according to any one of (1) to (9), the plurality of conductors are arranged substantially point-symmetrically with respect to the center of the cable when viewed in the axial direction of the cable; Camera module.

[0015] (11) A camera module according to any one of (1) to (10), a portion of the plurality of conducting wires that is exposed from an end of the covering member and connected to a terminal of the imaging module is covered with a hardened adhesive; Camera module.

[0016] (12) An endoscope, An insertion portion; a camera module according to any one of (1) to (11) provided in the insertion section; An endoscope comprising: [Effects of the Invention]

[0017] According to the present invention, it is possible to provide a camera module and an endoscope that can prevent cable breakage due to twisting. [Brief explanation of the drawings]

[0018] [Figure 1] FIG. 1 is a schematic diagram illustrating an example of a camera system according to an embodiment of the present invention. [Figure 2] 1 is a cross-sectional view showing a tip portion 12a and a bending portion 12b of an endoscope 12 having a camera module 20 according to an embodiment of the present invention. [Figure 3] 1 is a perspective view showing an example of a camera module 20 according to an embodiment of the present invention. [Figure 4] FIG. 4 is a side view of the camera module 20 shown in FIG. [Figure 5] FIG. 4 is a bottom view of the camera module 20 shown in FIG. [Figure 6] 10A and 10B are diagrams showing modified examples of fixing members attached to the cable 28. [Figure 7] 2 is a cross-sectional view showing an example of a cable 28 and a fixing member 35 cut perpendicularly to the axial direction of the cable 28. FIG. [Figure 8] FIG. 2 is a cross-sectional view showing an example of a cable 28 cut along its axial direction. DETAILED DESCRIPTION OF THE INVENTION

[0019] An example of an embodiment of the present invention will be described below with reference to the drawings. In this embodiment, the terms "parallel," "perpendicular," and "orthogonal" are used, but these terms include the error range generally accepted in the relevant technical field.

[0020] <Camera system> The camera system is an endoscopic camera system that irradiates an observation area, such as the inside of a subject, with illumination light (not shown), captures an image of the observation area, generates a display image of the observation area based on the image signal obtained by capturing the image, and displays the display image.

[0021] Fig. 1 is a schematic diagram showing an example of a camera system according to an embodiment of the present invention. As shown in Fig. 1, the camera system 10 includes an endoscope 12, a light source device 13, and a processor device 14. The camera system 10 has the same configuration as a general endoscope, except for the camera module 20 (see Figs. 2 and 3) in the endoscope 12.

[0022] The endoscope 12 has a camera module 20 (see FIGS. 2 and 3). Although not shown in detail, the endoscope 12 also has an insertion section that is inserted into the subject, an operation section that is connected to the insertion section, and a universal cord that extends from the operation section. The insertion section is composed of a tip section 12a (see FIG. 2), a bending section 12b (see FIG. 2) that is connected to the tip section 12a, and a flexible section that connects the bending section 12b and the operation section. The camera module 20 will be described in detail with reference to FIGS. 2 and 3.

[0023] The distal end 12a (see FIG. 2) of the endoscope 12 is provided with an illumination optical system that emits illumination light to illuminate the observation site, and a camera module 20 (see FIGS. 2 and 3) that has an imaging element and imaging optical system for imaging the observation site. The bending section 12b (see FIG. 2) is configured to be bendable in a direction perpendicular to the longitudinal axis of the insertion section. While FIG. 2 shows a configuration in which the bending section 12b bends in two directions, it normally bends in four directions as described below. The bending operation of the bending section 12b is controlled by an operating section. The flexible section is configured to be relatively flexible enough to be deformable to follow the shape of the insertion path of the insertion section. The endoscope 12 is, for example, a flexible endoscope having angles that can be bent in the UDLR directions (up / down / left / right directions) or a flexible endoscope having an insertion section that can be bent and rotated in the UD direction (up / down direction).

[0024] The operation unit is provided with buttons for operating the image capturing operation of the camera module 20 (see FIGS. 2 and 3) of the distal end portion 12a (see FIG. 2), knobs for operating the bending operation of the bending portion 12b (see FIG. 2), etc. The operation unit is also provided with an introduction port through which a treatment tool such as an electric scalpel is introduced. The insertion portion is provided with a treatment tool channel inside that extends from the introduction port of the operation unit to the distal end portion and through which a treatment tool such as forceps is inserted.

[0025] The universal cord has a connector at its end. The endoscope 12 is connected via the connector to a light source device 13 that generates illumination light emitted from an illumination optical system at the tip. The endoscope 12 is also connected via the connector to a processor device 14 that processes video signals acquired by a camera module 20 (see FIGS. 2 and 3) at the tip 12a (see FIG. 2).

[0026] The processor unit 14 processes the input video signal to generate video data of the observed region, and displays the generated video data on a monitor (not shown) or records it on a storage medium such as a hard disk. The processor unit 14 may be configured by a processor such as a personal computer.

[0027] The light source device 13 generates illumination light such as white light or light of a specific wavelength composed of three primary colors of light, such as red light (R), green light (G), and blue light (B). The light source device 13 supplies the illumination light to the endoscope 12, where it propagates through a light guide or the like within the endoscope 12 and is emitted from an illumination optical system at the tip (see FIG. 2) of the insertion section of the endoscope 12. The illumination light from the light source device 13 is used as light for capturing an image of an observation target site within a body cavity using the camera module 20 (see FIGS. 2 and 3) of the endoscope 12 to obtain an image signal of the observation target.

[0028] A light guide or a group of electric wires (cable) is housed inside the insertion section, the operation section, and the universal cord. The light guide guides illumination light generated by the light source device 13 to the illumination optical system in the distal end portion 12a (see FIG. 2). The group of electric wires transmits at least one of a signal and power between the camera module 20 (see FIGS. 2 and 3) in the distal end portion 12a (see FIG. 2) and the processor device 14.

[0029] The camera system 10 may also include a water tank for storing cleaning water, a suction pump for sucking up the suction material (including the supplied cleaning water) from within the body cavity, etc. The camera system 10 may further include a supply pump for supplying cleaning water from the water tank and gas such as external air to a conduit (not shown) within the endoscope 12.

[0030] Fig. 2 is a cross-sectional view showing the tip portion 12a and bending portion 12b of an endoscope 12 having a camera module 20 according to an embodiment of the present invention. As shown in Fig. 2, the endoscope 12 of the camera system 10 shown in Fig. 1 has the bending portion 12b connected to the tip portion 12a. The camera module 20 is disposed inside the tip portion 12a of the endoscope 12 as shown in Fig. 2. The camera module 20 is also referred to as a camera head.

[0031] The bending portion 12b is a cylindrical body having angles 15 with multiple joints. The angles 15 are connected to each other by connecting pins 16 and can rotate relative to each other. The connecting pins 16 form the joints in the bending portion 12b. Furthermore, an operating wire 17 is provided at the outer end of each angle 15 along the direction in which the angle 15 is arranged. The bending portion 12b is bent by pushing and pulling the operating wire 17. Note that there is another angle (not shown) connected by a connecting pin (not shown) that is perpendicular to the connecting pin 16 shown in FIG. 2. This angle (not shown) is also provided with an operating wire as described above. As a result, the bending portion 12b can be bent in four directions by operating the operating wire 17.

[0032] The tip of the operating wire 17 is fixed to the angle 15 by brazing, adhesive bonding, crimping, or the like. The angle 15, connecting pin 16, and operating wire 17 are made of, for example, stainless steel. The bending portion 12b is provided with an angle net (not shown) that covers the outer surface of the angle 15, and a soft bending portion outer skin (not shown) that covers the outer surface of the angle net. The angle net is made of metal wire such as stainless steel or copper, or a net woven with carbon fiber, or the like. The tip portion 12a is provided with a forceps outlet 21 in addition to the camera module 20. The tip portion 12a is also provided with a lighting device, an air supply nozzle, a water supply nozzle, and the like, although not shown.

[0033] <Camera Module 20> Fig. 3 is a perspective view showing an example of camera module 20 according to an embodiment of the present invention. Fig. 4 is a side view of camera module 20 shown in Fig. 3. Note that in Fig. 4, the illustration of connecting member 29 is partially omitted.

[0034] 3 and 4, camera module 20 has imaging lens 23, lens barrel 22, holder 24, imaging element 25, circuit board 26, prism 27, cable 28, and connecting member 29. Camera module 20 acquires an image of an object to be observed. Imaging lens 23, lens barrel 22, holder 24, imaging element 25, circuit board 26, and prism 27 are an example of the "imaging module" of the present invention.

[0035] Prism 27 is, for example, a right-angle prism in which incident surface 27a and exit surface 27b are orthogonal to each other. Prism 27 has an inclined surface 27c connecting incident surface 27a and exit surface 27b. Inclined surface 27c is a reflective surface of prism 27. Prism 27 is an example of an optical member arranged between lens barrel 22 and image sensor 25. However, the optical member is not limited to prism 27. Furthermore, the arrangement of prism 27 is not particularly limited. Furthermore, prism 27 may not be necessary depending on the arrangement position of image sensor 25, and a configuration in which another optical member is arranged may also be used. In this example, a prism is used to bend light by 90 degrees, but a configuration in which light is made to enter a sensor directly without using a prism may also be used.

[0036] The imaging lens 23 is an optical element that forms an image of light incident on the imaging lens 23 on a light receiving surface 25a of the imaging element 25. The imaging lens 23 is held by the lens barrel 22.

[0037] Lens barrel 22 is a cylindrical member that holds one or more imaging lenses 23 therein. Lens barrel 22 holds imaging lenses 23 so that optical axes C of imaging lenses 23 are perpendicular to incident surface 27a of prism 27. Camera module 20 has, for example, three imaging lenses 23, which are held by lens barrel 22.

[0038] Here, the direction parallel to the optical axis C is defined as the X direction. Of the two directions perpendicular to the optical axis C, one is defined as the Y direction and the other is defined as the Z direction. The Y direction corresponds to the width direction of the camera module 20, and the Z direction corresponds to the height direction of the camera module 20.

[0039] There are no particular limitations on the configuration of the imaging lens 23 and the lens barrel 22. For example, the imaging lens 23 may be configured to have one imaging lens 23, or two, or four or more imaging lenses 23. Furthermore, each imaging lens 23 may be a convex lens or a concave lens.

[0040] The imaging element 25 is an imaging element that captures an image by converting light focused by the imaging lens 23 into an electrical signal through photoelectric conversion. The imaging element 25 is a conventionally known imaging element, and may be, for example, a CCD (Charge Coupled Device) image sensor or a CMOS (Complementary Metal Oxide Semiconductor) image sensor.

[0041] The imaging element 25 is disposed on the opposite side of the holder 24 from the lens barrel 22. The imaging element 25 is electrically connected to the surface 26f of the first flat portion 26a of the circuit board 26, for example, via conductive bumps 34. The imaging element 25 is mounted on the circuit board 26 so that the light receiving surface 25a is parallel to the optical axis C of the imaging lens 23. An underfill layer (not shown) may be provided between the imaging element 25 and the circuit board 26 to firmly connect the imaging element 25 and the circuit board 26.

[0042] The bumps 34 are made of a metal or an alloy. Specifically, the bumps 34 are made of solder. Bumps 34 made of solder are also called solder balls. The bumps 34 are not limited to solder or the like as long as they can electrically connect the imaging element 25 and the circuit board 26. The imaging element 25 and the circuit board 26 may also be electrically connected directly.

[0043] The circuit board 26 is a board on which the imaging element 25 is mounted. In addition to the imaging element 25, electronic components 30, 30a, for example, are also mounted on the circuit board 26. The electronic components 30, 30a are used to drive the imaging element 25, and include, but are not limited to, a voltage regulator, a resistor, and a capacitor. The voltage regulator is a device that stabilizes the voltage to the imaging element 25 and outputs a constant voltage to the imaging element 25.

[0044] In the illustrated example, the circuit board 26 has a first planar portion 26a, a second planar portion 26c connected to the first planar portion 26a by a first bent portion 26b, and a third planar portion 26e connected to the second planar portion 26c by a second bent portion 26d. The first planar portion 26a and the third planar portion 26e are parallel to the optical axis C of the imaging lens 23. The second planar portion 26c is tilted at an angle with respect to the optical axis C of the imaging lens 23. The second planar portion 26c is not parallel to the optical axis C. The second planar portion 26c is tilted so that the second bent portion 26d is higher in the Z direction than the first bent portion 26b.

[0045] The circuit board 26 also has a plurality of connection terminals (not shown) on a back surface 26h of the third flat surface 26e facing the second flat surface 26c, through which signals or power are input and output to and from the image sensor 25 and the electronic components 30, 30a. A plurality of signal lines 28a arranged within the cable 28 are electrically connected to the connection terminals. The signal lines 28a connected to the connection terminals are exposed after the shield 28c and outer sheath 28d have been removed. The signal lines 28a are an example of a "conductor" in the present invention. The connection terminals are electronic contacts of the circuit board 26. The circuit board 26 is made of, for example, a flexible substrate. The circuit board 26 is made of, for example, a flexible printed circuit board.

[0046] The first bent portion 26b and the second bent portion 26d are both formed of curved surfaces, for example. The radii of curvature of the first bent portion 26b and the second bent portion 26d may be the same or different. In the illustrated example, the radius of curvature of the first bent portion 26b is larger than that of the second bent portion 26d. By adjusting the radii of curvature of the first bent portion 26b and the second bent portion 26d, it is possible to adjust the space between the first flat portion 26a and the second flat portion 26c and the space between the second flat portion 26c and the third flat portion 26e.

[0047] The imaging element 25 is mounted on the front surface 26f of the first flat portion 26a. An electronic component 30 is also mounted on the front surface 26f of the first flat portion 26a. Electronic components 30 and 30a are mounted on the back surface 26g of the second flat portion 26c, which faces the front surface 26f of the first flat portion 26a. Because the second flat portion 26c is inclined with respect to the first flat portion 26a, a large space is formed between the first flat portion 26a and the second flat portion 26c. This allows a large electronic component 30a to be mounted. For example, on the back surface 26g of the second flat portion 26c, the electronic component 30a mounted on the second bent portion 26d side is taller than the electronic component 30 mounted on the first bent portion 26b side.

[0048] A signal line 28a of the cable 28 is electrically connected to a connection terminal provided on the back surface 26h of the third flat surface 26e of the circuit board 26, and the imaging element 25 is electrically connected to the cable 28. Light formed as an image by the imaging lens 23 is converted into an electrical signal by the imaging element 25, and this electrical signal is transmitted via the cable 28. The cable 28 is inserted into the insertion section, operation section, universal cord, etc. of the endoscope 12, and is electrically connected to the processor device 14.

[0049] The cable 28 includes, for example, multiple signal wires 28a, a coating layer 28b that coats the multiple signal wires 28a, a shield 28c that surrounds the entire multiple signal wires 28a covered by the coating layer 28b, and an outer sheath 28d that coats the shield 28c. The outer sheath 28d forms the outer periphery of the cable 28. The cable 28 is a multi-core cable in which the multiple signal wires 28a are bundled together and surrounded by the shield 28c, and housed within the cylindrical outer sheath 28d. The diameter of the cable 28 is 2.5 mm or less. The cable 28 includes, for example, five signal wires 28a. The number of signal wires 28a depends on the configuration of the camera module 20 and is not limited to two, three, four, six, or more. The signal wires 28a are single wires, and include, for example, normal wires, coaxial wires, and twin-ax wires. The bundled signal wires 28a are wound, for example, in a spiral shape. The covering layer 28b, the shield 28c, and the outer jacket 28d are, for example, cylindrical. The "covering member" of the present invention is a member configured to include the shield 28c and the outer jacket 28d.

[0050] The prism 27 is disposed between the lens barrel 22 and the image sensor 25 via a cover glass 31. The prism 27 guides light that has passed through the imaging lens 23 to the light receiving surface 25a of the image sensor 25. The prism 27 bends the light that has passed through the imaging lens 23 held in the lens barrel 22 at an inclined surface 27c (reflecting surface) by, for example, 90° to change the optical path, and guides the light to the light receiving surface 25a of the image sensor 25. The transmitted light that has passed through the imaging lens 23 enters the prism 27, is reflected by the inclined surface 27c of the prism 27, and then enters the light receiving surface 25a of the image sensor 25. For example, the prism 27 is disposed so that the incident surface 27a faces the surface on the base end side of the lens barrel 22. The prism 27 is disposed so that the exit surface 27b faces the light receiving surface 25a of the image sensor 25. In this case, the prism 27 is disposed on the cover glass 31 with the exit surface 27b facing the cover glass 31. The cover glass 31 is disposed on the light receiving surface 25a of the image sensor 25 to protect the light receiving surface 25a. The prism 27 and the cover glass 31 are bonded together with, for example, a photo-curing adhesive. Note that the cover glass 31 may not be provided.

[0051] The holder 24 is a member that holds the lens barrel 22 and the prism 27. The holder 24 is a substantially cylindrical member, and the lens barrel 22 is fitted into the interior of the cylindrical portion to hold the lens barrel 22. The inner surface of the holder 24 and the outer peripheral surface of the lens barrel 22 are adhesively fixed together. Any of a variety of known adhesives used in conventional endoscopes can be used as the adhesive that bonds the holder 24 and the lens barrel 22 together. The same applies to adhesives that bond other components together.

[0052] The holder 24 has a polygonal flange portion 24b on the end surface of the base end side of the mounting tube portion 24a. Restricting members 24c are provided on both ends of the flange portion 24b in the Y direction. The prism 27 is disposed between the restricting members 24c, and its incident surface 27a abuts against the flange portion 24b while sandwiched between the restricting members 24c. This determines the position of the prism 27 in the X direction. The holder 24 holds the lens barrel 22 and the prism 27 in a predetermined position, thereby fixing the relative position between the lens barrel 22 and the prism 27, i.e., the relative position between the lens barrel 22 and the light receiving surface 25a of the image sensor 25. This positions the exit surface 27b of the prism 27 opposite the image sensor 25. The lens barrel 22 is adhesively fixed to the holder 24 after the relative position of the imaging lens 23 with respect to the holder 24 in the optical axis C direction is adjusted so that the light receiving surface 25a of the image sensor 25 is focused.

[0053] The connecting member 29 connects the holder 24 and the cable 28. The connecting member 29 holds the cable 28 inside. The connecting member 29 is a member formed, for example, by bending a single plate material. Specifically, the connecting member 29 has a shape obtained by bending a single plate material at two bending portions extending in the optical axis C direction. Therefore, the cross section of the connecting member 29 perpendicular to the optical axis C direction is approximately C-shaped. The connecting member 29 is arranged so that the connection terminals (connection points with the cable 28) on the circuit board 26 are enclosed inside the approximately C-shape. That is, the connecting member 29 has a base portion 29b that covers the circuit board 26 from above in the Z direction and a side portion 29c formed by bending an end of the base portion 29b. The side portion 29c has, for example, an edge 29g that is parallel to the second flat portion 26c of the circuit board 26. Edge 29g is located closer to base 29b than second flat surface 26c, and when connecting member 29 covers circuit board 26 from above, second flat surface 26c of circuit board 26 is exposed.

[0054] The connecting member 29 covers a part of the third flat portion 26e of the circuit board 26, the prism 27, and the tip end of the cable 28, and also serves as a cover member for the circuit board 26, the prism 27, and the cable 28. Furthermore, the connecting member 29 also functions as a protective member for the circuit board 26, the prism 27, and the cable 28.

[0055] The connecting member 29 also has a pair of arm portions 29a on the tip side. Tip portions 29h of the pair of arm portions 29a are each bent parallel to the Y direction and form claw portions. The pair of arm portions 29a sandwich the flange portion 24b of the holder 24, and the tip portions 29h of the arm portions 29a engage with each other, thereby fixing the connecting member 29 to the holder 24. The connecting member 29 also has a holding portion 29d that holds the cable 28 on the base end side of the side portion 29c. The holding portion 29d is bent along the outer sheath 28d of the cable 28, and its width in the Y direction narrows from the arm portions 29a toward the holding portion 29d. The cable 28 is fixed and held inside the holding portion 29d. The holding portion 29d is a member that is continuous with the side portion 29c.

[0056] The connecting member 29 connects the holder 24 and the cable 28, thereby preventing breakage of the signal line 28a at the connection point between the connection terminal on the circuit board 26 and the signal line 28a of the cable 28, for example, when the cable 28 is pulled. There are no particular restrictions on the material from which the connecting member 29 is made, but a metal material with high thermal conductivity is preferable. Examples of materials that can be used for the connecting member 29 include stainless steel and copper alloys.

[0057] Cable 28 is covered by an overlapping inner tube 36 (see FIG. 5) and an outer tube 37. Inner tube 36 is the inner tube. Outer tube 37 is the outer tube. Inner tube 36 and outer tube 37 protect cable 28, prevent cable 28 from bending, and prevent signal line 28a from breaking. Cable 28 is also provided with a fixing member 35. Fixing member 35 fixes cable 28, suppresses movement of signal line 28a within cable 28, and prevents signal line 28a from breaking.

[0058] FIG. 5 is a bottom view of the camera module 20 shown in FIG. 3. As shown in FIG. 5, the inner tube 36 and the outer tube 37, which are covered by the cable 28, have their respective tip ends 36a and 37a housed within the connecting member 29. For example, the tip end 36a of the inner tube 36 and the tip end 37a of the outer tube 37 are located closer to the lens barrel 22 than the rear end face 29e of the connecting member 29 on the side opposite to the lens barrel 22, and are positioned inside the holding portion 29d. The tip end 36a of the inner tube 36 and the tip end 37a of the outer tube 37 refer to the end of each tube on the lens barrel 22 side. The inner tube 36 and the outer tube 37 are, for example, heat-shrinkable tubes. Examples of materials for the inner tube 36 and the outer tube 37 include polyolefin, silicone, and fluororesin.

[0059] The fixing member 35 is provided at the tip of the cable 28 on the connecting member 29 side. The tip of the cable 28 is a connection portion between the cable 28 and the imaging module (circuit board 26). The fixing member 35 is a cable compression member that compresses and fixes the cable 28 from the outer periphery of the outer sheath 28d of the cable 28 toward the center of the cable 28. The fixing member 35 is, for example, an annular member, and is attached to the outer sheath 28d of the cable 28 and compresses it toward the center of the cable 28, that is, tightens it by crimping, thereby fixing the outer sheath 28d to the signal wires 28a of the cable 28. Crimping the cable 28 means fixing the covering member (the outer sheath 28d and the shield 28c) to the side of the multiple signal wires 28a in a compressed state.

[0060] The fixing member 35 is not limited to a circular ring shape, and may be a polygonal ring-shaped member, as long as it can fix the outer sheath 28d to the signal line 28a of the cable 28. Furthermore, the fixing member 35 does not have to be strictly ring-shaped, and may have a gap between the two, such as a C-shaped ring. In this case, the separated ends are brought closer together by crimping, thereby reducing the opening of the fixing member 35 and fixing the outer sheath 28d to the signal line 28a of the cable 28. Furthermore, the fixing member 35 may be, for example, a metal ring made of metal. The metal ring may be hollow, for example. Examples of metals that can be used for the fixing member 35 include stainless steel, brass, copper, aluminum, nickel-copper alloys, copper-zinc alloys, copper-tin alloys, and aluminum alloys.

[0061] In addition, the inner tube 36 and the outer tube 37 are covered on the outer periphery of the cable 28 so that a gap 39 is provided between the end 35b of the connecting member 29 on the holding portion 29d side of the fixing member 35 and the tip end 36a of the inner tube 36 and the tip end 37a of the outer tube 37.

[0062] Furthermore, the connecting member 29 has a recess 29f that protrudes inward of the connecting member 29 toward, for example, the cable 28 held therein. The recess 29f is provided so as to overlap at least a portion of a fixing member 35 that is provided on the cable 28. The recess 29f is formed, for example, by locally narrowing a side surface portion 29c of the connecting member 29. The recess 29f and the fixing member 35 are provided so that the narrowest portion of the recess 29f, i.e., the portion with the narrowest width, overlaps the fixing member 35. Specifically, the position of the narrowest portion of the recess 29f in the direction of the optical axis C of the imaging lens 23 overlaps with any position in the width of the fixing member 35 in the same direction of the optical axis C.

[0063] The holding portion 29d of the connecting member 29 and the outer sheath 28d of the cable 28 are fixed together with, for example, an adhesive 38. Similarly, the holding portion 29d of the connecting member 29 and the fixing member 35 attached to the outer sheath 28d are fixed together with the adhesive 38. Furthermore, among the multiple signal wires 28a of the cable 28, the signal wires 28a are fixed together with the adhesive 38 at portions exposed from the end of the covering member (the shield 28c and the outer sheath 28d) and connected to the connection terminals of the circuit board 26 (see FIG. 4).

[0064] When these members are fixed with adhesive 38, the adhesive 38 is in a hardened state. Therefore, the fixing member 35 attached to the outer cover 28d is circumferentially covered with the hardened adhesive 38 and fixed to the connecting member 29 by the hardened adhesive 38. The connecting member 29 is an example of the "housing" of the imaging module of the present invention. Similarly, the outer cover 28d of the cable 28 is circumferentially covered with the hardened adhesive 38 and fixed to the connecting member 29 by the hardened adhesive 38. Furthermore, the portions (see FIG. 4) of the multiple signal wires 28a exposed from the ends of the covering members (shield 28c and outer cover 28d) are entirely covered with the hardened adhesive 38, fixing the signal wires 28a to each other.

[0065] When the inner tube 36 and the outer tube 37 are fixed using the adhesive 38, it is preferable that the inner tube 36 and the outer tube 37 are softer than the adhesive 38 in a cured state. If the inner tube 36 and the outer tube 37 are softer than the adhesive 38 in a cured state, the inner tube 36 and the outer tube 37 can bend easily, and the load acting on the cable 28 at the holding portion 29d of the connecting member 29 can be reduced. If the inner tube 36 and the outer tube 37 are made of a fluororesin such as PTFE (polytetrafluoroethylene), for example, an epoxy resin-based adhesive is used as the adhesive 38. Instead of an epoxy-based adhesive, for example, a silicone-based adhesive or an acrylic-based adhesive may be used as the adhesive 38.

[0066] <Modifications of the fixing member 35> FIG. 6 is a diagram showing a modified example of a fixing member attached to cable 28. As shown in FIG. 6, a plurality of fixing members (two in this example) may be provided on cable 28. In this modified example, in addition to fixing member 35A provided in the same manner as fixing member 35 described in FIG. 5, fixing member 35B is provided. Fixing member 35B is disposed on the opposite side of imaging lens 23 from fixing member 35A. Fixing member 35B is provided along optical axis C of imaging lens 23, similar to fixing member 35A. Specifically, fixing member 35B is provided between fixing member 35A and tip end portion 36a of inner tube 36 and tip end portion 37a of outer tube 37.

[0067] In this modification, only the recess 29f overlapping the fixing member 35A is provided as the recess 29f of the connecting member 29, but this is not limited to this. For example, the recess 29f may be provided so as to overlap the fixing member 35B. In this case, the inner tube 36 and the outer tube 37 are arranged to cover the outer periphery of the cable 28 so that a gap 39 is provided between the end 35b of the fixing member 35B on the holding portion 29d side of the connecting member 29 and the tip end 36a of the inner tube 36 and the tip end 37a of the outer tube 37.

[0068] <Specific Configuration of Fixing Member 35> FIG. 7 is a cross-sectional view showing an example of the cable 28 and the fixing member 35 cut perpendicularly to the axial direction of the cable 28. As shown in FIG.

[0069] 7, cable 28 accommodates a plurality of (15 in this example) signal wires 28a. A cylindrical shield 28c is provided around the entirety of the plurality of signal wires 28a, and a cylindrical outer sheath 28d is provided around shield 28c. The 15 signal wires 28a within shield 28c are arranged substantially point-symmetrically with respect to the center of cable 28 when viewed in the axial direction of cable 28. However, the arrangement of signal wires 28a is not limited to the arrangement in this example, as long as it is point-symmetric with respect to the center of cable 28.

[0070] Furthermore, the fixing member 35 crimped to the cable 28 has a shape that is substantially point-symmetrical with respect to the center of the cable 28 when viewed in the axial direction of the cable 28. In this example, the fixing member 35 is crimped into a regular hexagonal shape that is point-symmetrical with respect to the center of the cable 28.

[0071] 8 is a cross-sectional view showing an example of cable 28 cut along the axial direction. Note that signal line 28a inside cable 28 is not shown.

[0072] As shown in FIG. 8, if the diameter of the cable 28 is d and the volume of the fixing member 35 is, for example, V, the relationship between the diameter d and the volume V is V / d 2 >0.35. Preferably, V / d 2 >0.4. The diameter of cable 28 refers to the diameter of the portion crimped by fixing member 35 before being crimped by fixing member 35. The diameter of cable 28 is equal to the diameter of outer jacket 28d. In this example, there is a single fixing member 35, but if there are multiple fixing members as shown in Figure 6, for example, the volume V of the fixing members is the total volume of the multiple fixing members. However, if fixing member 35 is hollow, the hollow is excluded.

[0073] Also, if the diameter of the circumscribed circle of the fixing member 35 caulking the cable 28 is OD, the relationship between the diameter OD of the circumscribed circle of the fixing member 35 and the diameter d of the cable 28 satisfies OD > d. The circumscribed circle of the fixing member 35 is a circle that circumscribes the fixing member 35 as viewed from the axial direction of the fixing member 35.

[0074] Also, if the diameter of the inscribed circle of the fixing member 35 caulking the cable 28 is ID and the diameter of the outer peripheral portion of the shield 28c is sd, the relationship between the diameter ID of the inscribed circle of the fixing member 35 and the diameter sd of the shield 28c satisfies ID < sd. The inscribed circle of the fixing member 35 is a circle that is inscribed in the fixing member 35 as viewed from the axial direction of the fixing member 35.

[0075] As described above, in the camera module 20 of the present embodiment, the diameter d of the cable 28 and the volume V of the fixing member 35 satisfy V / d 2 > 0.35, and preferably, V / d 2 > 0.4. According to this configuration, it is possible to sufficiently secure the length (width) of the fixing member 35 in the axial direction of the cable 28 or the thickness of the fixing member 35 having an annular shape. Therefore, even if the cable 28 is twisted due to the fastening force when the fixing member 35 is caulked, the signal line 28a in the cable 28 can be fixed so as not to move in the axial direction of the cable 28 with respect to the covering members (shield 28c and outer skin 28d). As a result, disconnection of the signal line 28a connected to the circuit board 26 (imaging module) can be suppressed.

[0076] Particularly, in the case of a flexible endoscope having an angle that can be bent in the UDLR direction or a flexible endoscope having an insertion portion that can be bent in the UD direction and rotated, for example, if a plurality of signal lines 28a accommodated in the cable 28 are wound in a spiral shape, when the cable 28 is twisted, the signal lines 28a wound in a spiral shape are likely to move in the axial direction of the cable 28. Even for a cable 28 having such a structure, the relationship between the diameter d of the cable 28 and the volume V of the fixing member 35 is V / d 2By making it greater than 0.35, the signal line 28a can be fixed to the covering member by the fixing member 35 so as not to move in the axial direction of the cable 28.

[0077] Furthermore, camera module 20 is configured so that diameter ID of the inscribed circle of fixing member 35 that crimps cable 28 is smaller than diameter sd of the outer periphery of shield 28c. This allows signal line 28a in cable 28 to be more firmly fixed with the fastening force generated when fixing member 35 is crimped so that signal line 28a does not move in the axial direction of cable 28 relative to the covering member.

[0078] Furthermore, according to camera module 20, fixing member 35, which is attached by crimping to cable 28, is covered with hardened adhesive 38, and fixing member 35 is fixed to connecting member 29 by hardened adhesive 38. Therefore, cable 28, which is crimped to fixing member 35, can be fixed to connecting member 29, and even if a tensile force is applied to cable 28 in the axial direction, cable 28 can be prevented from being pulled out of connecting member 29.

[0079] Furthermore, camera module 20 is configured so that the diameter OD of the circumscribing circle of fixing member 35 that crimps cable 28 is larger than the diameter d of cable 28. Therefore, the protruding portion of fixing member 35 that protrudes outward from the outer periphery of cable 28 catches on hardened adhesive 38 provided around fixing member 35 and cable 28, so that cable 28 can be further prevented from being pulled out of connecting member 29 even if a tensile force is applied to cable 28 in the axial direction.

[0080] Furthermore, according to camera module 20, the shape of fixing member 35 after crimping is configured to be approximately point symmetric with respect to the center of cable 28. Therefore, pressure caused by crimping fixing member 35 can be applied uniformly to cable 28, and damage to cable 28 can be suppressed.

[0081] Furthermore, according to camera module 20, multiple signal lines 28a in cable 28 are arranged so as to be approximately point symmetric with respect to the center of cable 28. Therefore, when fixing member 35 is crimped, the pressure caused by the crimping can be applied approximately uniformly to each signal line 28a, and damage to cable 28 can be suppressed.

[0082] Furthermore, according to camera module 20, among the multiple signal wires 28a of cable 28, the signal wires 28a at the portions exposed from the ends of the covering members (shield 28c and outer jacket 28d) and connected to the connection terminals of circuit board 26 (see FIG. 4) are covered and fixed to each other with adhesive 38. Therefore, when a force is applied to cable 28 in a direction that causes it to be pulled out from connecting member 29, it is possible to prevent the pulling force from being applied only to a single signal wire 28a, and to prevent breakage of signal wire 28a.

[0083] Furthermore, according to camera module 20, connecting member 29 is provided with recessed portion 29f that protrudes inward, so that when connecting member 29 and cable 28 are fixed with adhesive 38, recessed portion 29f of connecting member 29 catches on hardened adhesive 38, thereby further firmly fixing cable 28. Furthermore, recessed portion 29f makes it easy to position the center of connecting member 29 and the center of cable 28.

[0084] Furthermore, according to the camera module 20, a gap 39 is provided between the end 35b of the fixing member 35 and the tip 36a of the inner tube 36 and the tip 37a of the outer tube 37, thereby increasing the adhesive area of the filled adhesive 38 and enabling the cable 28 to be firmly fixed to the connecting member 29.

[0085] Next, the results of an evaluation of the resistance of cable 28 to disconnection from connecting member 29 will be described. Similar to the example described above, cable 28 was created by sequentially covering 15 signal wires 28a with shield 28c and outer jacket 28d. Fixing member 35 was attached to the outer periphery of cable 28 by crimping, and V / d, which shows the relationship between the diameter d of cable 28 and the volume V of fixing member 35, was calculated.2 The value of was changed as shown in Table 1, and the cable 28 was evaluated for its difficulty in coming off.

[0086] [Table 1]

[0087] The evaluation results were divided into three levels: ◎, ◯, and △, with ◎ being the cable that did not come off the connecting member 29, ◯ being difficult to come off, and △ being easy to come off.

[0088] From the above evaluation results, V / d 2 It was confirmed that by making V / d larger than 0.35, it was possible to make it difficult for the cable 28 in the camera module 20 to come off the connecting member 29. 2 It was confirmed that by making V / d in Table 1 larger than 0.4, it is possible to make it more difficult for the cable 28 to come off the connecting member 29. 2 =0.63 is the result when two fixing members are provided as shown in FIG. [Explanation of symbols]

[0089] 10 Camera System 12 Endoscopy 12a,29h,37a Tip 12b Curved section 13 Light source device 14 Processor unit 15 Angle 16 connecting pin 17 Control wire 20 Camera Module 21 Forceps exit 22 Lens barrel 23 Imaging lens 24 Holder 24a Mounting tube 24b flange 24c Regulatory Material 25 Image sensor 25a Photosensitive surface 26 Circuit Board 26a First flat portion 26b First bend 26c Second flat section 26d Second bend 26e Third plane 26f surface 26g,26h back side 27 Prism 27a Entrance plane 27b Output surface 27c slope 28 Cable 28a signal line 28b Covering layer 28c shield 28d Hull 29 Connecting members 29a Arm section 29b base 29c Side part 29d Holding part 29e Rear end surface 29f recess 29g edge 30,30a Electronic Components 31 Coverslip 34 Bump 35, 35A, 35B fixing member 35b end 36 Inner tube 37 Outer tube 38 Adhesive 39 Gap

Claims

1. A camera module for an endoscope, An imaging module; a cable connected to the imaging module and including a plurality of conductors and a covering member covering the plurality of conductors; at least one fixing member provided on an outer periphery of the covering member at a connection portion between the cable and the imaging module, the fixing member crimping the cable; Equipped with When the diameter of the cable is d and the volume of the fixing member is V, V / d ２ > 0.35, Camera module.

2. 2. The camera module according to claim 1, the fixing member is covered with a hardened adhesive and fixed to a housing of the imaging module by the adhesive; Camera module.

3. 2. The camera module according to claim 1, V / d ２ > 0.4, Camera module.

4. 2. The camera module according to claim 1, When the diameter of the circumscribing circle of the fixing member that crimps the cable is defined as OD, OD>d is satisfied. Camera module.

5. 2. The camera module according to claim 1, the covering member includes a shield covering the plurality of conductors and an outer cover covering the shield, When the diameter of the inscribed circle of the fixing member that crimps the cable is defined as ID and the diameter of the outer circumferential portion of the shield is defined as sd, ID<sd is satisfied. Camera module.

6. 2. The camera module according to claim 1, The fixing member is an annular member. Camera module.

7. 7. The camera module according to claim 6, The fixing member is a metal ring. Camera module.

8. 2. The camera module according to claim 1, The diameter of the cable is 2.5 mm or less. Camera module.

9. 2. The camera module according to claim 1, the fixing member has a shape that is substantially point-symmetrical with respect to the center of the cable when viewed in the axial direction of the cable; Camera module.

10. 2. The camera module according to claim 1, the plurality of conductors are arranged substantially point-symmetrically with respect to the center of the cable when viewed in the axial direction of the cable; Camera module.

11. 2. The camera module according to claim 1, a portion of the plurality of conducting wires that is exposed from an end of the covering member and connected to a terminal of the imaging module is covered with a hardened adhesive; Camera module.

12. An endoscope, An insertion portion; a camera module according to any one of claims 1 to 11, which is provided in the insertion section; An endoscope comprising:

Images