Endoscope imaging device, endoscope, and ultrasonic endoscope

Abstract

Provided are an endoscope imaging device, an endoscope, and an ultrasonic endoscope that protect an imaging element therein from static electricity with a simple structure. This endoscope imaging device acquires an image of an object being observed and comprises: a holder that holds an imaging lens directly or holds a lens barrel containing the imaging lens; an imaging element; a signal cable that electrically connects to the imaging element; and a coupling member that couples the holder and the signal cable. The holder and the coupling member are composed of a conductor. The signal cable includes a shield layer that covers a plurality of signal lines together and an outer skin that covers the outside of the shield layer. The outer skin covers the shield layer so that a portion of the shield layer is exposed at an end portion of the signal cable on the holder side. The tip end of the shield layer is located closer to the holder than the tip end of the outer skin, and the tip end of the outer skin is located closer to the holder than the rear end of the coupling member. The exposed portion of the shield layer and the coupling member are electrically connected using a connecting member. A second electric resistance between the holder and the coupling member is smaller than a first electric resistance between the holder and the imaging element.

Description

Endoscopic imaging device, endoscope, and ultrasonic endoscope

[0001] The present invention relates to an endoscopic imaging device, an endoscope, and an ultrasonic endoscope that acquire images of an observation target, and more particularly to an endoscopic imaging device, an endoscope, and an ultrasonic endoscope that are provided with anti-static measures.

[0002] In recent years, diagnoses and the like have become commonplace using endoscope systems equipped with an endoscopic light source device, an endoscope (endoscopic scope), and a processor device. The endoscope has an insertion section that is inserted into the body of a subject, and illumination light from the endoscopic light source device is irradiated onto an object of observation via the insertion section. The endoscope captures an image of the object of observation illuminated by the illumination light using an imaging element to generate an image signal. The processor device processes the image signal generated by the endoscope to generate an observation image to be displayed on a monitor. The imaging element is electrically connected to a signal cable via a circuit board such as a flexible wiring board, and the signal cable is electrically connected to the processor device. Countermeasures against static electricity have traditionally been implemented in endoscopes.

[0003] For example, Patent Document 1 describes an endoscope including an insertion section having at least a tip portion to be inserted into an object to be examined, a lens unit provided at the tip portion, an imaging element disposed on the opposite side of the lens unit from the object to be examined, and a linear conductor disposed so that its tip extends toward the lens unit beyond the imaging element and its base end passes inside the insertion section. As shown in Figures 3 and 8 of Patent Document 1, a long, thin linear conductor is provided along a transmission cable from the outside of the lens unit.

[0004] Japanese Patent Application Laid-Open No. 2019-025207

[0005] As described above, the endoscope of Patent Document 1 requires a long, thin linear conductor to be provided along the transmission cable from the outside of the lens unit, resulting in a complex structure. An object of the present invention is to provide an endoscopic imaging device, an endoscope, and an ultrasonic endoscope that have a simple structure and protect the imaging element from static electricity.

[0006] In order to achieve the above-mentioned object, invention [1] is an endoscopic imaging device that acquires an image of an observation target, the endoscopic imaging device comprising: a holder that holds an imaging lens directly or a lens barrel having an imaging lens installed therein; an imaging element that receives light that has passed through the imaging lens and performs photoelectric conversion; a signal cable that is electrically connected to the imaging element; and a connecting member that connects the holder and the signal cable, the holder and the connecting member being made of conductors; the signal cable having a shielding layer that collectively covers a plurality of signal lines and an outer jacket that covers the outside of the shielding layer; at the end of the signal cable facing the holder, the outer jacket has an exposed portion that covers the shielding layer; the signal cable is held by the connecting member; the tip of the exposed portion of the shielding layer on the holder side is closer to the holder than the tip of the outer jacket on the holder side, and the tip of the outer jacket is located closer to the holder than the rear end of the connecting member on the opposite side from the holder; the exposed portion of the shielding layer and the connecting member are electrically connected by a connecting member; and a second electrical resistance between the holder and the connecting member is smaller than a first electrical resistance between the holder and the imaging element.

[0007] Invention [2] is the endoscopic imaging device according to Invention [1], in which the connecting member has a conductive wire wound around the outer peripheral surface of the exposed portion of the shielding layer at least once, and the wound conductive wire is connected to the shielding layer by soldering. Invention [3] is the endoscopic imaging device according to Invention [1] or [2], in which the connecting member has a circuit board electrically connected to the imaging element, the circuit board has a terminal portion, and the shielding layer around which the conductive wire is wound and the terminal portion are electrically connected and fixed by soldering.

[0008] Invention [4] is an endoscopic imaging device according to any one of Inventions [1] to [3], in which the connecting member is joined to the connecting member on the outside of the connecting member. Invention [5] is an endoscopic imaging device according to Invention [4], in which the connecting member has a narrow portion at the rear end opposite the holder, the length of which in the width direction perpendicular to the optical axis of the imaging lens is shorter than the tip end on the holder side, and the connecting member is joined to the connecting member at the narrow portion. Invention [6] is an endoscopic imaging device according to any one of Inventions [1] to [5], in which the connecting member has a tip main body that fixes the holder or the lens barrel. Invention [7] is an endoscopic imaging device according to Invention [6], in which the tip main body is made of resin. Invention [8] is an endoscope having the endoscopic imaging device according to any one of Inventions [1] to [7]. Invention [9] is an ultrasound endoscope having the endoscopic imaging device according to Invention [7].

[0009] According to the present invention, it is possible to provide an endoscopic imaging device, an endoscope, and an ultrasonic endoscope that can protect an imaging element from static electricity with a simple structure.

[0010] FIG. 1 is a schematic diagram showing an example of an endoscopic system according to an embodiment of the present invention. FIG. 2 is a schematic perspective view showing an example of an endoscopic imaging device according to an embodiment of the present invention. FIG. 3 is a schematic perspective view showing a connecting member of an example of an endoscopic imaging device according to an embodiment of the present invention. FIG. 4 is a schematic side view showing an example of an endoscopic imaging device according to an embodiment of the present invention. FIG. 5 is a schematic top view showing an example of an endoscopic imaging device according to an embodiment of the present invention. FIG. 6 is a schematic perspective view showing an enlarged view of a main part of an example of an endoscopic imaging device according to an embodiment of the present invention. FIG. 7 is a schematic perspective view showing an example of a signal cable used in an endoscopic imaging device according to an embodiment of the present invention. FIG. 8 is a schematic diagram showing another example of an endoscopic system according to an embodiment of the present invention. FIG. 9 is a schematic cross-sectional view showing an example of an ultrasonic endoscope according to an embodiment of the present invention.

[0011] The endoscopic imaging device, endoscope, and ultrasonic endoscope of the present invention will be described in detail below based on the preferred embodiments shown in the accompanying drawings. Note that the drawings described below are illustrative for explaining the present invention, and the present invention is not limited to the drawings shown below. Note that in the following, the "to" symbol indicating a range of values ​​includes the values ​​written on both sides. For example, when ε is a value ε α ~Number ε β That is, the range of ε is the number ε α and the number ε β The range includes ε α ≦ε≦ε β In the following description, terms such as "parallel," "perpendicular," and "orthogonal" include a generally acceptable error range in the relevant technical field.

[0012] [Example of Endoscopic System] An endoscopic system irradiates an observation site, such as inside the body of a subject, with illumination light (not shown), captures an image of the observation site, generates a display image of the observation site based on an image signal obtained by capturing the image, and displays the display image. FIG. 1 is a schematic diagram showing an example of an endoscopic system according to an embodiment of the present invention. The endoscopic system 10 includes an endoscope 12, a light source device 14, and a processor device 16. The endoscopic system 10 has the same configuration as a general endoscope, except for an endoscopic imaging device 20 (see FIG. 2 ) of the endoscope 12, which will be described later. The endoscopic system 10 may further include a water tank for storing cleaning water or the like, a suction pump for sucking aspirates (including supplied cleaning water) from within the body cavity, and the like. The endoscopic system 10 may further include a supply pump for supplying cleaning water from the water tank or external gas such as air to a conduit (not shown) within the endoscope.

[0013] The endoscope 12 has an endoscopic imaging device 20 (see FIG. 2). Although not shown in detail, the endoscope 12 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, and the insertion section is composed of a tip section, a bending section that is connected to the tip section, and a flexible section that connects the bending section and the operation section. The endoscopic imaging device will be described later.

[0014] An endoscopic imaging device 20 (see FIG. 2 ) having an illumination optical system that emits illumination light to illuminate the observation site, or an imaging element and imaging optical system that capture images of the observation site, is provided at the distal end 12 a of the endoscope 12. The bending section is configured to be bendable in a direction perpendicular to the longitudinal axis of the insertion section, and the bending operation of the bending section is controlled by the 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.

[0015] The operation section is provided with buttons for operating the imaging operation of the endoscopic imaging device 20 (see FIG. 2) at the tip section 12a, knobs for operating the bending operation of the bending section, etc. The operation section is also provided with an introduction port through which a treatment tool such as an electric scalpel is introduced, and a treatment tool channel is provided inside the insertion section that extends from the introduction port to the tip section and through which a treatment tool such as forceps is inserted.

[0016] A connector is provided at the end of the universal cord, and the endoscope 12 is connected via the connector to a light source device 14 that generates illumination light emitted from an illumination optical system at the tip, and a processor device 16 that processes video signals acquired by an endoscopic image pickup device 20 (see FIG. 2) at the tip 12a. At least one of signals and power is transmitted between the endoscopic image pickup device 20 (see FIG. 2) and the processor device 16 via a group of electric wires.

[0017] The processor unit 16 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 16 may be configured by a processor such as a personal computer.

[0018] The light source device 14 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), and supplies it 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 of the insertion section of the endoscope 12 to illuminate the area to be observed within the body cavity, in order to capture an image of the area to be observed within the body cavity using the endoscopic imaging device 20 (see Figure 2) of the endoscope 12 and obtain an image signal of the area to be observed.

[0019] A light guide or a group of electric wires (signal cables) is housed inside the insertion section, the operation section, and the universal cord. Illumination light generated by the light source device 14 is guided to the illumination optical system of the distal end portion 12a via the light guide, and the light is emitted from the distal end surface 12b of the distal end portion 12a.

[0020] [Example of Endoscopic Imaging Device] FIG. 2 is a schematic perspective view showing an example of an endoscopic imaging device according to an embodiment of the present invention, and FIG. 3 is a schematic perspective view showing a connecting member of the example of the endoscopic imaging device according to an embodiment of the present invention. FIGS. 4 and 5 are schematic side views showing an example of an endoscopic imaging device according to an embodiment of the present invention. FIG. 6 is a schematic top view showing an example of an endoscopic imaging device according to an embodiment of the present invention, and FIG. 7 is a schematic perspective view showing an enlarged view of a main portion of the example of the endoscopic imaging device according to an embodiment of the present invention. Note that FIG. 5 shows the endoscopic imaging device 20 of FIG. 4 with the arm portion 40c and the holding portion 40b on one side of the connecting member 40 removed. The endoscopic imaging device 20 shown in FIG. 2 is mounted on the distal end portion 12a of the endoscope 12 of the endoscopic system 10 shown in FIG. 1. The endoscopic imaging device 20 is also referred to as a camera head. The distal end surface 12b of the distal end portion 12a of the endoscope 12 shown in FIG. 1 is the surface 50a (see FIG. 4) of the distal end body 50 (see FIG. 4) of the endoscopic imaging device 20.

[0021] The endoscopic imaging device 20 shown in Fig. 2 acquires an image of an observation target. The endoscopic imaging device 20 includes, for example, an imaging lens 23, a lens barrel 22 that holds the imaging lens 23, a holder 24, an imaging element 25, a circuit board 26, a prism 27, and a signal cable 28. The endoscopic imaging device 20 also includes a connecting member 40. Here, the direction parallel to the optical axis C of the imaging lens 23 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 endoscopic imaging device 20, and the Z direction corresponds to the height direction of the endoscopic imaging device 20.

[0022] The imaging element 25 and electronic components 30, 30a are mounted on the circuit board 26. Mounting refers to being electrically connected. As shown in FIG. 5 , the circuit board 26 has at least 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, and the second planar portion 26c is inclined with respect to the optical axis C. In other words, the second planar portion 26c is inclined at an angle with respect to the optical axis C of the imaging lens 23, and is not parallel to the optical axis C. For example, the second planar portion 26c is inclined so that the second bent portion 26d is higher in the Z direction than the first bent portion 26b. A signal cable 28 is electrically connected to a back surface 26h of the third flat surface 26e that faces the second flat surface 26c. More specifically, the circuit board 26 has a plurality of connection terminals (not shown) on the back surface 26h through which signals or power are input and output to and from the image sensor 25 and the electronic components 30, 30a. A signal line 28a of the signal cable 28 is electrically connected to the connection terminals. By configuring the circuit board 26 as described above, the height of the endoscopic image pickup device 20 in the Z direction can be reduced, and the endoscopic image pickup device 20 can be made more compact.

[0023] 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 also 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, and the optical member is not limited to prism 27. The arrangement of prism 27 is also 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 be used.

[0024] 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.

[0025] The lens barrel 22 is a cylindrical member, and has one or more imaging lenses 23 disposed therein. The lens barrel 22 holds the one or more imaging lenses 23. The lens barrel 22 holds the imaging lenses 23 so that the optical axis C of the imaging lenses 23 is perpendicular to the incident surface 27a (see FIG. 5 ) of the prism 27. The endoscopic imaging device 20 has, for example, three imaging lenses 23, which are held by the lens barrel 22.

[0026] 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 a single imaging lens 23, or may be a two or four or more imaging lenses 23. Furthermore, each imaging lens 23 may be a convex lens or a concave lens.

[0027] 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 a CCD (Charge Coupled Device) image sensor or a CMOS (Complementary Metal Oxide Semiconductor) image sensor can be used.

[0028] The imaging element 25 is disposed on the opposite side of the holder 24 from the lens barrel 22. As shown in FIG. 4 , the imaging element 25 is electrically connected to the surface 26 f of the first flat portion 26 a of the circuit board 26 via, for example, conductive bumps 34. Also as shown in FIG. 4 , the imaging element 25 is mounted on the circuit board 26 so that the light-receiving surface 25 a is parallel to the optical axis C of the imaging lens 23. Note that "mounted" means electrically connected. 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.

[0029] The bumps 34 are made of a metal or alloy. More specifically, the bumps 34 are made of solder. A bump 34 made of solder is also called a solder ball. The bumps 34 are not limited to solder, 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 directly electrically connected. The underfill layer relieves stress that occurs at the joint between the imaging element 25 and the circuit board 26, for example, at the bumps 34, due to differences in the thermal expansion coefficients of the imaging element 25 and the circuit board 26. The underfill layer firmly connects the imaging element 25 and the circuit board 26, improving the reliability of the electrical connection and resulting in a highly reliable endoscopic imaging device 20. The underfill agent constituting the underfill layer is not particularly limited, and any agent commonly used as a sealing resin between the imaging element 25 and the circuit board 26 can be used as appropriate. For example, a one-component heat-curing epoxy resin can be used as the underfill agent. In this case, after the underfill agent is supplied, it is heated and maintained at a predetermined temperature to form an underfill layer.

[0030] The circuit board 26 is a board on which the imaging element 25 is mounted. In addition to the imaging element 25, for example, electronic components 30, 30a 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. The circuit board 26 is made up of, for example, a flexible substrate, such as a flexible printed circuit board.

[0031] The first bent portion 26b and the second bent portion 26d of the circuit board 26 are both curved. The radii of curvature of the first bent portion 26b and the second bent portion 26d may be the same or different. As shown in FIG. 5 , the first bent portion 26b has a larger radius of curvature than the second bent portion 26d. By adjusting the radii of curvature of the first bent portion 26b and the second bent portion 26d, 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 can be adjusted. The first bent portion 26b and the second bent portion 26d are not limited to being composed of only curved surfaces as long as they have a curved surface; for example, they may have a flat surface and a curved surface. The radii of curvature can be obtained as follows. First, an image of the circuit board 26 from the side is acquired. Using the acquired image, the locations corresponding to the radii of curvature of the first bent portion 26b and the second bent portion 26d are identified. A curve is fitted to the relevant portion, and the radius of curvature of the curve is measured using a ruler. The measured value is the radius of curvature. Note that the measurement of the radius of curvature described above also includes importing the acquired image of the circuit board 26 into a computer and measuring the radius of curvature of the first bent portion 26b and the second bent portion 26d using software. Fitting a curve to the relevant portion corresponding to the radius of curvature and measuring the radius of curvature of the curve using a ruler also includes performing the process using software on a computer.

[0032] As shown in FIG. 4 , the imaging element 25 is mounted on the surface 26f of the first planar portion 26a. Electronic components 30 are also mounted on the surface 26f of the first planar portion 26a. Electronic components 30, 30a are mounted on the back surface 26g of the second planar portion 26c, which faces the surface 26f of the first planar portion 26a. Because the second planar portion 26c is inclined with respect to the first planar portion 26a, a large space is created between the first planar portion 26a and the second planar portion 26c. This allows for the mounting of larger electronic components 30a. For example, on the back surface 26g of the second planar portion 26c, the electronic components 30a mounted on the second bent portion 26d side are taller than the electronic components 30a mounted on the first bent portion 26b side. In this way, electronic components of various sizes can be mounted, enabling effective use of the space in the endoscopic imaging device 20. As described above, connection terminals (not shown) are provided on the back surface 26h of the third flat surface portion 26e, which faces the second flat surface portion 26c. Electronic components 30 are mounted on the front surface 26i of the third flat surface portion 26e. The arrangement of the image sensor 25, electronic components 30, 30a, connection terminals, etc. on the circuit board 26 is not particularly limited.

[0033] A signal line 28a (see FIG. 4) of the signal cable 28 is electrically connected to a connection terminal (not shown) provided on the back surface 26h (see FIG. 5) of the third flat surface 26e of the circuit board 26, electrically connecting the image sensor 25 and the signal cable 28. The image sensor 25 converts light into an electrical signal, which is then transmitted via the signal cable 28. The signal cable 28 is inserted through the insertion section, operation section, universal cord, etc. of the endoscope and electrically connected to the processor device 16 (see FIG. 1). The circuit board 26 also has a planar terminal portion 63 provided on the back surface 26h of the third flat surface 26e, on the opposite side of the holder 24 from the connection terminal (not shown). The planar terminal portion 63 has a trapezoidal shape when viewed from the front surface 26i of the third flat surface 26e, for example, but the shape is not particularly limited. The terminal portion 63 is also electrically connected to a ground layer (not shown) of the circuit board 26. The terminal portion 63 is called a pad. The terminal portion 63 is electrically connected to the shield layer 28c of the signal cable 28 via a connecting member 60, as described below. Therefore, the terminal portion 63 is preferably provided at a position facing an exposed portion 28e of the shield layer 28c of the signal cable 28, as described below.

[0034] As shown in FIG. 5 , the signal cable 28 includes, for example, a plurality of signal wires 28a, a coating layer 28b that coats each of the signal wires 28a, a shielding layer 28c that is provided around the entirety of the signal wires 28a coated with the coating layer 28b and collectively covers the signal wires 28a, and an outer jacket 28d that coats the shielding layer 28c. The signal cable 28 is a multi-core cable in which the signal wires 28a are bundled together, the shielding layer 28c is provided around the signal wires 28a, and the signal wires 28a are housed within a cylindrical outer jacket 28d. The shielding layer 28c is, for example, grounded. As described above, the outer jacket 28d forms the outer periphery of the signal cable 28. The coating layer 28b, the shielding layer 28c, and the outer jacket 28d are, for example, cylindrical. The shielding layer 28c of the signal cable 28 is also referred to as a shield. The signal cable 28 includes, for example, five signal wires 28a. The number of signal lines 28a depends on the configuration of the endoscopic imaging device 20 and is not particularly limited, and may be two, three, four, six or more. At the end 29 of the signal cable 28 on the holder 24 side, the outer sheath 28d is provided with an exposed portion 28e and covers the shielding layer 28c. The shielding layer 28c has the exposed portion 28e on the end 29 side. The holder 24 side refers to the imaging lens 23 side, that is, the side of the surface 50a of the tip body 50 shown in FIG. 4.

[0035] The signal cable 28 is held by and housed within the coupling member 40. In this state, a tip 29b of the exposed portion 28e of the shield layer 28c of the signal cable 28 on the holder 24 side is closer to the coupling member 40 than a tip 29a of the outer sheath 28d of the signal cable 28 on the holder 24 side. The tip 29a of the outer sheath 28d of the signal cable 28 on the holder 24 side is located closer to the coupling member 40 than a rear end 40j of the coupling member 40 on the opposite side from the holder 24. In this case, the outer sheath 28d of the signal cable 28 is housed within an interior 41d of the coupling member 40. The exposed portion 28e of the shield layer 28c of the signal cable 28 and the coupling member 40 are electrically connected by a connecting member 60. In this case, the coupling member 40 and the coupling member 40 are made of conductors, as described below, and the coupling member 40 and the holding member 24 are electrically connected by the connecting member 60.

[0036] In the endoscopic imaging device 20, the second electrical resistance between the holder 24 and the connecting member 40 is smaller than the first electrical resistance between the holder 24 and the imaging element 25. Therefore, static electricity flows preferentially between the holder 24 and the connecting member 40, where the electrical resistance is smaller, rather than between the holder 24 and the imaging element 25. This prevents static electricity from flowing to the imaging element 25, thereby protecting the imaging element 25 from static electricity. Furthermore, the imaging element 25 can be protected from static electricity with a simple structure in which the exposed portion 28e of the shield layer 28c is electrically connected to the connecting member 40 by the connecting member 60. The first electrical resistance between the holder 24 and the imaging element 25 and the second electrical resistance between the holder 24 and the connecting member 40 are measured using a tester. Specifically, the connecting member 60 is provided on the shield layer 28c, and the connecting member 60 will be described later.

[0037] 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 image sensor 25 to the light receiving surface 25a of the image sensor 25. The prism 27 bends the light that has passed through the image sensor 23 held in the lens barrel 22 by, for example, 90° at its inclined surface 27c, i.e., its reflective surface, 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 image sensor 23 enters the prism 27, is reflected by the inclined surface 27c, i.e., the reflective surface, of the prism 27, and is then incident on 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 used. Alternatively, the image sensor 25 may be bonded to the holder 24 instead of the prism 27.

[0038] The holder 24 is a member that holds the lens barrel 22 and the prism 27, and is made of a conductor. The conductor that makes up the holder 24 is, for example, a metal or an alloy. 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. Various known adhesives that are 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.

[0039] The holder 24 has a polygonal flange portion 24b on the end surface of the base end side of the mounting tube portion 24a. A restricting member 24d is provided on each end of the flange portion 24b in the Y direction. The restricting member 24d is, for example, a convex member. The restricting member 24d has, for example, a rectangular outer shape. As described below, the arm portion 40c of the connecting member 40 engages with the restricting member 24d. The prism 27 is disposed between the restricting members 24d, and the incident surface 27a abuts against the flange portion 24b while sandwiched between the restricting members 24d. This positions the prism 27 in the X direction. The holder 24 holds the lens barrel 22 and the prism 27 in predetermined positions, thereby fixing the relative positions of the lens barrel 22 and the prism 27, i.e., the relative positions of the lens barrel 22 and the light receiving surface 25a of the image sensor 25. The exit surface 27b of the prism 27 faces the image sensor 25. The lens barrel 22 is adhesively fixed to the holder 24 after the relative position of the lens barrel 22 with respect to the holder 24 in the direction of the optical axis C of the image sensor 23 is adjusted so that the focus is on the light receiving surface 25a of the image sensor 25. The direction of the optical axis C is the direction in which the optical axis C of the image sensor 23 extends. The direction of the optical axis C of the image sensor 23 is parallel to the X direction.

[0040] The connecting member 40 connects the holder 24 and the signal cable 28 and is made of a conductor. The conductor that makes up the connecting member 40 is, for example, a metal or an alloy. There are no particular limitations on the metal material that makes up the connecting member 40, but a metal material with high thermal conductivity is preferred. Considering processability, availability, strength, etc., stainless steel and copper alloys are preferred for the connecting member 40. Considering electrical resistance, copper alloys with low electrical resistance are preferred for the connecting member 40.

[0041] The connecting member 40 holds and houses the signal cable 28 in an interior 41d. The connecting member 40 is a member formed by bending a single plate material, for example, as shown in Fig. 3. Specifically, the connecting member 40 has a shape in which a single plate material is bent at two bending portions 40k, 40m extending in the direction of the optical axis C. Therefore, the cross section of the connecting member 40 perpendicular to the direction of the optical axis C is approximately C-shaped.

[0042] As shown in FIG. 3 , the connecting member 40 includes a flat bottom portion 40a formed by bending a single plate material, and a flat holding portion 40b continuous with the bottom portion 40a. The holding portion 40b side of the connecting member 40 is defined as a rear end 41a. The rear end 41a is the opposite end of the holder 24. The signal cable 28 is held inside the holding portion 40b. The flat holding portions 40b, which face each other across an opening in the holding portion 40b, each include an arm portion 40c. The connecting member 40 includes a pair of arm portions 40c. The arm portions 40c are bent outward from the holding portion 40b at the rear end 41a side and then extend linearly. Therefore, the pair of arm portions 40c are spaced farther apart at the front end 41b than at the rear end 41a, and this spacing is determined appropriately to match the restricting member 24d of the holder 24 shown in FIG. 2 . Each arm 40c has an opening 40d at its tip 41b. The maximum length in the Y direction from the outside of one arm 40c to the outside of the other arm 40c is the maximum width of the connecting member 40.

[0043] The connecting member 40 has a narrow portion 41c at its rear end 41a opposite the holder 24. The narrow portion 41c has a length in the width direction perpendicular to the optical axis C of the imaging lens 23, i.e., a length in the Y direction, that is shorter than the length of the tip 41b on the holder 24 side. The holding portion 40b facing in the Y direction is bent at a bent portion 40k on the tip 41b side, widens in the width direction, and connects to the arm portion 40c. The bent portion 40k is the connection between the holding portion 40b and the arm portion 40c. The holding portion 40b is bent at a bent portion 40m on the rear end 41a side, and has a surface 40p on the rear end 41a side that is parallel to the optical axis C. The parallel surface 40p faces the Y direction. The opposing parallel surface 40p and the bottom 40a form the narrow portion 41c. For example, the holding portion 40b has a window portion 40n that extends from the bottom 40a to partway in the Z direction. The window 40n is an opening that penetrates the holding portion 40b and is provided in a range that includes the bent portion 40m.

[0044] In the connecting member 40, an opening 40d of the arm portion 40c engages with the restricting member 24d of the holder 24. The opening 40d is formed, for example, by cutting out a portion of the arm portion 40c in a rectangular shape. The opening 40d may be the same in size and shape as the outer shape of the restricting member 24d. The above-described definition of the opening 40d being the same in size and shape as the outer shape of the restricting member 24d includes a tolerance range generally accepted in the relevant technical field. Therefore, the opening 40d and the restricting member 24d may be a clearance fit, a transition fit, or an interference fit. In the following description, the definition of "same in size and shape" includes a tolerance range generally accepted in the relevant technical field, as described above.

[0045] Each arm portion 40c has, for example, an edge 40e parallel to the second planar portion 26c of the circuit board 26. The edge 40e is located higher in the Z direction than the second planar portion 26c, so that the second planar portion 26c of the circuit board 26 is exposed when the connecting member 40 covers the circuit board 26 from above. Each arm portion 40c also has, for example, a cover portion 40f. As shown in FIG. 6 , the cover portions 40f are not connected to each other in the Y direction, leaving a gap 40g. The cover portion 40f is partially provided in the X direction, with an opening 40h on the tip 41b side of the cover portion 40f. The cover portion 40f is a member disposed on the surface 26i of the third planar portion 26e of the circuit board 26. The gap 40g and the opening 40h in the cover portion 40f prevent contact with the electronic component 30 disposed on the surface 26i of the third planar portion 26e. The connecting member 40 covers a part of the third flat portion 26e of the circuit board 26, the prism 27, and the tip end of the signal cable 28, and also serves as a cover member for the circuit board 26, the prism 27, and the signal cable 28. Furthermore, the connecting member 40 also functions as a protective member for the circuit board 26, the prism 27, and the signal cable 28. Note that the connecting member 40 is not particularly limited to the configuration shown in Fig. 3, and may have no cover portion 40f, or the gap 40g of the cover portion 40f may be wider.

[0046] As described above, the configuration including the engagement portions 41 that engage the openings 40d of the pair of arm portions 40c with the restricting members 24d of the holder 24 allows the openings 40d to fit into the convex restricting members 24d, thereby shortening the length of the endoscopic imaging device 20 in the Y direction perpendicular to the optical axis C and preventing the size of the endoscopic imaging device 20 from increasing. Furthermore, a strong fixation between the holder 24 and the connecting member 40 can be achieved. Furthermore, by matching the thickness of the arm portions 40c with the height of the restricting members 24d, when the openings 40d of the pair of arm portions 40c are engaged with the restricting members 24d of the holder 24, the length of the endoscopic imaging device 20 in the Y direction perpendicular to the optical axis C can be further shortened. This configuration allows the endoscopic imaging device 20 to be made more compact.

[0047] In the connecting member 40, the pair of arm portions 40c are preferably bent so that the front ends 41b of the arm portions 40c are closer to each other than the rear ends 41a. That is, the pair of arm portions 40c are preferably bent in a closing direction. This allows the openings 40d of the arm portions 40c to fit into the restricting members 24d of the holder 24 by simply spreading the arm portions 40c, facilitating assembly. As described above, the pair of arm portions 40c are preferably bent so that the front ends 41b are closer to each other than the rear ends 41a of the arm portions 40c, but this may be the case in the state of the components before assembly. Furthermore, although the arm portions 40c are provided with through-hole openings 40d, this is not limited thereto and may be recesses with a bottom rather than through-holes. The signal cable 28 is attached and held inside the holding portion 40b of the connecting member 40. The method of attaching the signal cable 28 is not particularly limited as long as the signal cable 28 does not come off the holding portion 40b and the signal line 28a does not come off when the endoscope is in use, and for example, the signal cable 28 can be attached to the connecting member 40 using an adhesive as described below.

[0048] In the holder 24, the two restricting members 24d have the same size and shape, i.e., are congruent, as described above, but may have different sizes and shapes. Furthermore, the shape of the restricting member 24d (protrusion) in the holder 24 is not particularly limited to the above-described quadrangle, but may be a circle, an ellipse, or a polygon such as a triangle, pentagon, or hexagon, or a shape formed by combining these shapes. Furthermore, instead of a single shape, multiple pieces of the same shape may be arranged, or a specific pattern may be formed. In the engaging portion 41, one protrusion and one recess engage at one location, but the number of engaging locations is not limited to one, and one protrusion may have multiple engaging locations.

[0049] The size of the convex portion of the holder 24 is preferably large enough to cover at least a portion of the side surface 27d of the prism 27. By making the convex portion large enough to cover at least a portion of the side surface 27d of the prism 27, the prism 27 can be more stably clamped and fixed, allowing for stable positioning. Furthermore, the convex portion can be used to position the prism in the Y direction relative to the holder during assembly. The upper limit of the size of the convex portion of the holder 24 can be set to a size that completely covers the side surface 27d of the prism 27. Furthermore, by providing two opposing restricting members 24d in the holder 24, the prism 27 and the circuit board 26 are surrounded by the arm portion 40c. This stabilizes the engagement between the holder 24 and the connecting member 40 and also protects the prism 27 and the circuit board 26. While the holder 24 is configured with two restricting members 24d, this is not limited to this, and three or more convex portions may be provided as long as the size is not increased. In other words, the number of engaging portions can be three or more.

[0050] The connecting member 40 connects the holder 24 and the signal cable 28, respectively, and prevents the connection between the connection terminal on the circuit board 26 and the signal line 28a of the signal cable 28 from being pulled, for example, and causing the connection between the connection terminal and the signal line 28a to be broken.

[0051] The arm portion 40c of the connecting member 40 and the restricting member 24d of the holder 24, as well as the holding portion 40b of the connecting member 40 and the outer sheath 28d of the signal cable 28, are adhesively fixed together using, for example, an adhesive. In this case, for example, the interior 41d of the connecting member 40 is filled with adhesive to adhesively fix the connecting member 40, the circuit board 26, and the signal cable 28 together. When adhesively fixed together, the adhesive is in a hardened state. For example, an epoxy resin adhesive, a silicone adhesive, or an acrylic adhesive can be used as the adhesive. By providing the above-mentioned window portion 40n in the connecting member 40, the adhesive adheres to the inner periphery of the window portion 40n, thereby making the above-mentioned adhesive fixation more solid.

[0052] Furthermore, a fixing member 35 may be provided on the outer sheath 28d of the signal cable 28. The fixing member 35 is provided on the outer sheath 28d of the signal cable 28 and fastens the outer sheath 28d to the signal wires 28a of the signal cable 28 by tightening. The fixing member 35 is, for example, an annular member. After the annular member is passed through the outer sheath 28d of the signal cable 28, the annular member is compressed from the periphery and crimped to fasten the fixing member 35 and fix it to the outer sheath 28d of the signal cable 28. The fixing member 35 is not limited to being annular as long as it can be fixed to the outer sheath 28d of the signal cable 28, and may be an annular member having a polygonal shape. The fixing member 35 is made of, for example, a metal or an alloy.

[0053] Furthermore, as described above, the signal cable 28 used in the endoscopic imaging device 20 has a structure in which multiple signal wires 28a are bundled by the outer sheath 28d. Because the signal wires 28a are easily damaged, they need to be protected by the outer sheath 28d or the connecting member 40. As described above, the connecting member 40 is made of metal or the like, and the rigidity of the connecting member 40 changes abruptly at the rear end 40j of the connecting member 40, resulting in a large load being concentrated on the signal cable 28. For this reason, if the outer sheath 28d shifts due to bending of the endoscope or sliding against other contents, exposing the signal wires 28a outside the connecting member 40, the signal wires 28a will be damaged near the rear end 40j of the connecting member 40. However, by fixing the outer sheath 28d of the signal cable 28 with the fixing member 35, the fixing strength of the outer sheath 28d of the signal cable 28 can be increased. When the signal cable 28 is fixed to the connecting member 40 by overlapping it, the adhesive area of ​​the outer sheath 28d of the signal cable 28 is reduced, but this reduction can be compensated for by the fixing strength of the fixing member 35. This increases the joint strength of the signal cable 28 and improves the joint reliability of the signal cable 28. It is more preferable to provide the window 40n in a position facing at least a portion of the fixing member 35. In other words, it is more preferable to provide the window 40n in a position where at least a portion of the fixing member 35 is visible from the outside of the connecting member 40. This allows for even stronger adhesive fixation when adhesive is filled into the interior 41d of the connecting member 40 to adhesively fix the connecting member 40, the circuit board 26, and the signal cable 28.

[0054] In the endoscopic imaging device 20, the observation image captured by the imaging element 25 through the imaging lens 23 is focused on the light receiving surface 25a of the imaging element 25 and converted into an electrical signal. This electrical signal is output to the processor unit 16 (see Figure 1) via the signal cable 28, converted into a video signal, and the observation image is displayed on a monitor connected to the processor unit 16.

[0055] In the endoscopic imaging device 20, as shown in Fig. 5, the inclined surface 27c of the prism 27 faces the second bent portion 26d. When viewed in a direction perpendicular to the light receiving surface 25a of the imaging element 25, that is, in the Z direction in Fig. 5, it is preferable that at least a portion of the second bent portion 26d of the circuit board 26 overlaps the inclined surface 27c of the prism 27. This results in the second bent portion 26d fitting into the space on the inclined surface 27c side of the prism 27, and by effectively utilizing the space on the inclined surface 27c side of the prism 27, the length of the endoscopic imaging device 20 in the optical axis C direction can be shortened, thereby making the endoscopic imaging device 20 more compact in the optical axis C direction.

[0056] In the endoscopic imaging device 20, a portion of the inclined surface 27c of the prism 27 and a portion of the second bent portion 26d of the circuit board 26 are preferably connected with a photocurable adhesive (not shown), and a portion of the first bent portion 26b and / or a portion of the second flat portion 26c are preferably connected with a portion of the signal cable 28 and / or a portion of the third flat portion 26e with a photocurable adhesive (not shown). This allows the shape of the circuit board 26 to be maintained and shortens the manufacturing time of the endoscopic imaging device 20. The photocurable adhesive is, for example, an adhesive that cures with ultraviolet light having a wavelength of approximately 100 nm to 400 nm, visible light having a wavelength of more than 400 nm and less than 780 nm, or infrared light having a wavelength of approximately 780 nm to 1 mm. The photocurable adhesive is, for example, an epoxy resin-based photocurable adhesive, an acrylic resin-based photocurable adhesive, or a silicone-based photocurable adhesive. Alternatively, an adhesive that combines photocuring and heat curing may be used. This photo-curing adhesive can also be used to bond the prism 27 and the cover glass 31 together.

[0057] FIG. 8 is a schematic perspective view showing an example of a signal cable used in the endoscopic imaging device according to an embodiment of the present invention. FIG. 8 shows an example of a signal cable 28 provided with a connecting member 60. In FIG. 8, the solder connecting the conductive wire 61 to the exposed portion 28e of the shield layer 28c is not shown. The connecting member 60 described above includes, for example, a conductive wire 61. The conductive wire 61 is wound around the outer surface of the exposed portion 28e of the shield layer 28c at least once. The conductive wire 61 wound around the exposed portion 28e of the shield layer 28c is connected to the shield layer 28c with solder (not shown). This electrically connects the connecting member 60 to the exposed portion 28e of the shield layer 28c. The conductive wire 61 may be strip-shaped instead of linear. As long as the conductive wire 61 is wound around at least one turn, electrical connection between the connecting member 60 and the shield layer 28c can be ensured. Therefore, the number of turns of the conductive wire 61 is not particularly limited as long as it is at least one turn. The number of turns of the conductive wire 61 is determined as appropriate based on the wire diameter of the conductive wire 61, the length of the exposed portion 28e in the optical axis direction, and other factors. For example, as shown in FIG. 5 , the conductive wire 61 is wound around the entire outer periphery of the exposed portion 28e of the shield layer 28c. The conductive wire 61 wound around the exposed portion 28e of the shield layer 28c is connected to the shield layer 28c with solder (not shown). This prevents cracking of the shield layer 28c. The conductive wire 61 is made of, for example, a metal or alloy, and more specifically, copper, a copper alloy, aluminum, or an aluminum alloy. The conductive wire 61 is preferably made of copper because of its low electrical resistance and excellent workability.

[0058] As shown in FIGS. 6 and 8 , the connecting member 60 has an extending portion 61a arranged along the outer sheath 28d of the signal cable 28. For example, the extending portion 61a extends in the optical axis direction. The connecting member 60 has a curved portion 61b that is continuous with the extending portion 61a and extends from the interior 41d of the coupling member 40 around the rear end 40j to lead the conductive wire 61 to the exterior of the coupling member 40. The connecting portion 61c is continuous with the curved portion 61b and is arranged outside the holding portion 40b of the coupling member 40 along the holding portion 40b. For example, the connecting portion 61c extends in the optical axis direction. For example, the extending portion 61a and the connecting portion 61c are parallel to each other. The configuration of the connecting member 60 is not limited to that shown in FIGS. 6 and 8 .

[0059] As shown in FIG. 7 , the connection portion 61c of the connection member 60 is joined to the holding portion 40b outside the holding portion 40b using, for example, solder 64. In this way, the connection member 60 is joined to the connecting member 60 outside the linking member 40. The linking member 40, the solder 64, and the connection member 60 are all electrically conductive. This allows the exposed portion 28e of the shield layer 28c and the linking member 40 to be electrically connected by the connection member 60. By joining the connection member 60 to the connecting member 60 outside the linking member 40, for example, when joining using solder, the soldering operation itself and the flux removal operation can be facilitated, improving the joining workability. Furthermore, the narrow portion 41c to which the connection member 60 is joined is located closer to the optical axis C than the arm portion 40c of the linking member 40, as shown in FIG. 6 , and is lowered toward the optical axis C relative to the arm portion 40c. Even if the connecting member 60 is joined to the outside of the holding portion 40b that constitutes the narrow width portion 41c, the connecting member 60 is located closer to the optical axis C in the Y direction than the arm portion 40c. For this reason, by joining the connecting member 60 to the narrow width portion 41c, the space of the endoscopic imaging device 20 can be used effectively.

[0060] 5, the shield layer 28c around which the conductive wire 61 is wound and the terminal portion 63 are electrically connected and fixed by solder 65. By sandwiching the solder 65 between the shield layer 28c and the circuit board 26 in this manner, one side will not come off while the other side is being soldered. This improves the ease of soldering between the shield layer 28c and the circuit board 26.

[0061] Furthermore, for example, the endoscopic imaging device 20 has a distal end body 50 (see FIG. 4 ) that fixes the holder 24 or the lens barrel 22. More specifically, as shown in FIG. 4 , the distal end body 50 has a through-hole 50b that penetrates in the optical axis direction. The lens barrel 22 is inserted into and fixed in the through-hole 50b. The distal end body 50 is made of, for example, resin, metal, or alloy. As described above, the surface 50a of the distal end body 50 is the distal end surface 12b of the distal end portion 12a of the endoscope 12. Here, as described above, in the endoscopic imaging device 20, the exposed portion 28e of the shield layer 28c and the connecting member 40 are electrically connected by the connecting member 60, and the second electrical resistance between the holder 24 and the connecting member 40 is smaller than the first electrical resistance between the holder 24 and the imaging element 25. Therefore, when a current caused by static electricity or the like flows through the tip body 50, the current flows preferentially through a path with lower electrical resistance from the tip body 50 through the holder 24 to the coupling member 40, the connection member 60, and the shield layer 28c of the signal cable 28, rather than flowing from the tip body 50 through the holder 24 to the image sensor 25. In this way, the current flowing through the tip body 50 is prevented from flowing to the image sensor 25, thereby protecting the image sensor 25 from static electricity. Note that in FIG. 4, the tip body 50 is configured to fix the lens barrel 22, but the present invention is not limited to this. For example, the tip body 50 may be configured to fix the holder 24.

[0062] Furthermore, although the endoscopic imaging device 20 is configured to hold the imaging lens 23 by the lens barrel 22, the present invention is not limited to this. For example, the holder 24 may directly hold the imaging lens 23. In the endoscopic imaging device 20, a ceramic plate may be provided on the back surface of the first flat surface portion 26a of the circuit board 26.

[0063] Although the endoscopic imaging device 20 is configured such that the light receiving surface 25a of the imaging element 25 is arranged parallel to the optical axis C, the configuration is not limited to this as long as the exposed portion 28e of the shield layer 28c of the signal cable 28 and the coupling member 40 are electrically connected by the connecting member 60. For example, the light receiving surface 25a of the imaging element 25 may be arranged perpendicular to the optical axis C. In this case, a cover glass 31 may or may not be placed on the light receiving surface 25a of the imaging element 25.

[0064] [Another Example of an Endoscopic System] Figure 9 is a schematic diagram showing another example of an endoscope system according to an embodiment of the present invention. In Figure 9, components that are the same as those in the endoscope system 10 shown in Figure 1 are designated by the same reference numerals, and detailed descriptions thereof will be omitted. The endoscope system 10a shown in Figure 9 has an ultrasonic endoscope 13. The endoscope system 10a includes the ultrasonic endoscope 13, an ultrasonic processor device 70, an endoscope processor device 71, a light source device 72, and a monitor 73. The endoscope system 10a also includes a water tank 74 that stores cleaning water or the like, and a suction pump 75 that aspirates material from within the subject, for example, from within a body cavity.

[0065] The ultrasonic endoscope 13 has an insertion section 76 that is inserted into a subject, for example, a body cavity, an operation section 77 that is connected to the proximal end of the insertion section 76 and that is used by the surgeon to perform operations, and a universal cord 78 that has one end connected to the operation section 77. A distal end surface 76b of a distal end section 76a of the insertion section 76 corresponds to the distal end surface 12b of the distal end section 12a of the endoscope 12 shown in Fig. 1. As described above, the distal end surface 12b of the distal end section 12a is the surface 50a (see Fig. 4) of the distal end body 50 (see Fig. 4) of the endoscopic imaging device 20 (see Fig. 4).

[0066] The operation unit 77 is provided with an air / water supply button 79a for opening and closing an air / water supply line (not shown) from the water supply tank 74, and a suction button 79b for opening and closing an suction line (not shown) from the suction pump 75. The operation unit 77 also has a pair of angle knobs 79c and a treatment tool insertion port 79d.

[0067] The other end of the universal cord 78 is provided with a connector 80a connected to the ultrasonic processor device 70, a connector 80b connected to the endoscope processor device 71, and a connector 80c connected to the light source device 72. The ultrasonic endoscope 13 is detachably connected to the ultrasonic processor device 70, the endoscope processor device 71, and the light source device 72 via these connectors 80a, 80b, and 80c. The connector 80c also has an air / water supply tube 81 connected to the water supply tank 74 and a suction tube 82 connected to the suction pump 75.

[0068] The insertion section 76 has, in order from the distal end, a distal rigid section 85 having an endoscopic observation section 83 and an ultrasonic transducer 84, a bending section 86 connected to the proximal end side of the distal rigid section 85, and a flexible section 87 connecting the proximal end side of the bending section 86 to the distal end side of the operation section 77. The distal rigid section 85, bending section 86, and flexible section 87 are arranged along the longitudinal axis A of the elongated insertion section 76. The bending section 86 has multiple bending pieces 97 (see FIG. 10) connected to it, and is configured to be freely bendable. The flexible section 87 is elongated and flexible.

[0069] The bending portion 86 is remotely bent by rotating a pair of angle knobs 79c provided on the operation portion 77. This allows the distal rigid portion 85 to be oriented in a desired direction. Note that Figure 10, which will be described later, shows a plurality of bending pieces 97 that constitute the bending portion 86 and a plurality of bending operation wires 98 (two in Figure 10). The distal ends of these bending operation wires 98 are connected to the bending pieces 97, and the proximal ends are connected to the pair of angle knobs 79c.

[0070] The ultrasonic processor device 70 shown in Figure 9 generates ultrasonic signals for generating ultrasonic waves in multiple ultrasonic vibrators 92 (see Figure 10) that make up the ultrasonic transducer 84, and supplies the ultrasonic signals to the ultrasonic vibrators 92 (see Figure 10). Ultrasonic waves are emitted from the multiple ultrasonic vibrators 92 toward the observation target area. The ultrasonic processor device 70 receives and acquires echo signals (reflected waves) reflected from the observation target area using the ultrasonic vibrators 92, and performs various signal processing on the acquired echo signals to generate an ultrasonic image. The generated ultrasonic image is displayed on the monitor 73.

[0071] The observation target area is illuminated by illumination light from the light source device 72 in the endoscopic observation section 83. The endoscopic processor device 71 receives and acquires image signals acquired from the observation target area, and performs various signal processing and image processing on the acquired image signals to generate an endoscopic image. The generated endoscopic image is displayed on the monitor 73.

[0072] The monitor 73 displays an ultrasound image and an endoscopic image in response to the video signals generated by the ultrasound processor device 70 and the endoscopic processor device 71. The monitor 73 can be switched to display only one of the ultrasound images and the endoscopic image, or both images can be displayed simultaneously.

[0073] [An Example of an Ultrasonic Endoscope] Next, the ultrasonic endoscope 13 will be described in more detail. Fig. 10 is a schematic cross-sectional view showing an example of an ultrasonic endoscope according to an embodiment of the present invention. In Fig. 10, the same components as those in the endoscopic imaging device 20 shown in Fig. 2 are designated by the same reference numerals, and detailed description thereof will be omitted. Fig. 10 shows the tip portion of the ultrasonic endoscope 13, i.e., the tip portion 76a of the insertion section 76, and shows a state in which the above-mentioned endoscopic imaging device 20 is provided within the tip portion 76a of the insertion section 76.

[0074] As described above, the distal end hard portion 85 has, in order from the distal end, the endoscopic observation unit 83 and the ultrasonic transducer 84. The distal end hard portion 85 is provided with the endoscopic observation unit 83 for acquiring endoscopic images, and the proximal end is provided with the ultrasonic transducer 84 for acquiring ultrasonic images.

[0075] The distal rigid portion 85 has a distal cap 88 disposed distally of the ultrasonic transducer 84, and a proximal ring 89 disposed proximal to the ultrasonic transducer 84. The distal cap 88 secures the lens barrel 22 of the endoscopic imaging device 20. The distal cap 88 may also be configured to secure the holder 24 of the endoscopic imaging device 20. The distal cap 88 and the proximal ring 89 are exterior members. A distal surface 88a of the distal cap 88 is the distal surface 76b of the distal end 76a of the insertion section 76. The distal cap 88 corresponds to the distal body 50 (see FIG. 4) of the endoscopic imaging device 20 described above, and the distal surface 88a of the distal cap 88 corresponds to the surface 50a (see FIG. 4) of the distal body 50. The distal cap 88 and the proximal ring 89 are made of a resin such as a hard resin, and are made of an insulating material that has electrical insulation properties. By making the distal cap 88 out of an insulating material such as a hard resin, discharge and leakage are suppressed when an ultrasonic signal is supplied to the ultrasonic vibrator 92 in the form of a voltage.

[0076] A metal ring 90 is connected to the proximal end side of the distal cap 88. The endoscopic imaging device 20, the signal cable 28, the forceps conduit 91, etc. are arranged inside the metal ring 90. The ultrasonic transducer 84 is arranged outside the metal ring 90. The metal ring 90 is a cylindrical conductive member that supports the ultrasonic vibrator 92 and is made of, for example, stainless steel.

[0077] The ultrasonic transducer 84 is configured by arranging a plurality of ultrasonic vibrators 92 that transmit and receive ultrasonic waves in the circumferential direction of the outer peripheral wall of the metal ring 90. That is, the ultrasonic transducer 84 is a radial type ultrasonic transducer in which a plurality of ultrasonic vibrators 92 are arranged along the circumferential direction around the longitudinal axis A. An ultrasonic vibrator array 92a is configured with a plurality of ultrasonic vibrators 92 arranged in a cylindrical shape along the circumferential direction around the longitudinal axis A, for example, a multi-channel array of 48 to 192 channels, including 48 to 192 rectangular parallelepiped ultrasonic vibrators 92. More specifically, the ultrasonic vibrator array 92a is configured such that a plurality of ultrasonic vibrators 92 are arranged, for example, in a cylindrical two-dimensional array at a predetermined pitch.

[0078] The ultrasonic transducers 92 are each connected to a cable (not shown). A plurality of cables are connected to the ultrasonic transducers 92. The cables connected to the ultrasonic transducers 92 are housed in, for example, an ultrasonic shielded cable and inserted from the bending portion 86 through the flexible portion into the operation unit 77 (see FIG. 9). The cables are then inserted from the operation unit into a universal cord 78 (see FIG. 9) and connected to an ultrasonic connector 80a (see FIG. 9). The ultrasonic connector 80a is connected to the ultrasonic processor device 70 (see FIG. 9). Ultrasonic signals (not shown) generated by the ultrasonic processor device 70 are supplied to the ultrasonic transducers 92 via a plurality of cables. For example, the ultrasonic signals are supplied to the ultrasonic transducers 92 in the form of voltage. The ultrasonic transducers 92 are configured, for example, with electrodes formed on the bottom surface of a thick piezoelectric film made of PZT (lead zirconate titanate) or PVDF (polyvinylidene fluoride).

[0079] Each of the multiple ultrasonic transducers 92 is provided with an individual electrode 110a and a common electrode 110b. The individual electrode 110a is provided on the inside of the ultrasonic transducer 92. The common electrode 110b is provided on the outside of the ultrasonic transducer 92. The common electrode 110b is an electrode common to all of the ultrasonic transducers 92, and is, for example, a ground electrode. A flexible wiring board (FPC) 115 is connected to the common electrode 110b. The flexible wiring board 115 is attached to the side surface on the base end side of the backing material layer 112. The flexible wiring board 115 is electrically connected to an ultrasonic connector 80a (see FIG. 9) of the ultrasonic processor device 70 (see FIG. 9) by a shielded cable (not shown).

[0080] A backing material layer 112 is provided between the common electrode 110b of the ultrasonic transducer 92 and the metal ring 90. The backing material layer 112 supports each ultrasonic transducer 92 of the ultrasonic transducer array 92a from the common electrode 110b side. An acoustic matching layer 113 is provided on the ultrasonic transducer 92. The acoustic matching layer 113 is used to achieve acoustic impedance matching between a subject such as a human body and the ultrasonic transducer 92, and is provided on the outer periphery of the ultrasonic transducer array 92a. An acoustic lens 114 is attached on the outer periphery of the acoustic matching layer 113. The acoustic lens 114, acoustic matching layer 113, ultrasonic transducer 92, and backing material layer 112 are layered in this order from the outside to the inside of the tip portion 76a of the insertion section 76.

[0081] The backing material constituting the backing material layer 112 functions as a cushioning material that flexibly supports each ultrasonic transducer 92 of the ultrasonic transducer array 92a. For this reason, the backing material is made of a rigid material such as hard rubber, with an ultrasonic attenuation material (ferrite, ceramics, etc.) added as needed. The acoustic lens 114 is used to focus the ultrasonic waves emitted from the ultrasonic transducer array 92a toward the observation target area. The acoustic lens 114 is made of, for example, a silicone-based resin (e.g., millable silicone rubber (HTV rubber), liquid silicone rubber (RTV rubber)), butadiene-based resin, polyurethane-based resin, etc. The acoustic matching layer 113 matches acoustic impedance between the subject and the ultrasonic transducer 92 and increases the transmittance of ultrasonic waves. Therefore, powders such as titanium oxide, alumina, or silica are mixed into the acoustic lens 114 as needed.

[0082] A balloon 100 surrounding the ultrasonic transducer 84 is detachably attached to the distal end rigid portion 85. An ultrasonic transmission medium (not shown) is supplied to the interior 100a of the balloon 100. The ultrasonic transmission medium is, for example, water or oil. Here, ultrasonic waves and echo signals are attenuated in air. Therefore, water is supplied to the interior 100a of the balloon 100 to inflate it, and the inflated balloon 100 is brought into contact with the observation target area to remove air from between the ultrasonic transducer 84 and the observation target area. This suppresses the attenuation of ultrasonic waves and echo signals, thereby enabling the acquisition of a good ultrasonic image. The balloon 100 will be described later.

[0083] The endoscopic observation section 83 has a treatment tool outlet 93, an observation window 94, an illumination window (not shown), a nozzle (not shown), and the like, which are opened in the distal end surface 88a of the distal cap 88. In other words, the ultrasonic endoscope 13 is a direct-view type ultrasonic endoscope that has an observation window 94 in the distal end surface 88a of the rigid distal end section 85. Note that a pair of illumination windows (not shown) are provided, for example, on either side of the observation window 94.

[0084] A forceps conduit 91 is connected to the treatment instrument outlet 93. The forceps conduit 91 has a forceps pipe 95 whose distal end is connected to the treatment instrument outlet 93, and a forceps tube 96 whose distal end is connected to the proximal end of the forceps pipe 95. The forceps tube 96 extends from the inside of the bending portion 86 to the proximal end of the flexible portion, and the proximal end of the forceps tube 96 is connected to a treatment instrument insertion port 79d (see FIG. 9 ) of the operation portion. A treatment instrument (not shown), such as forceps, is inserted into the forceps tube 96 from the treatment instrument insertion port 79d and is led out of the treatment instrument outlet 93 via the forceps pipe 95.

[0085] The endoscopic imaging device 20 is disposed behind (toward the proximal end of) the observation window 94. The configuration of the endoscopic imaging device 20 is as described above, and therefore a detailed description thereof will be omitted. The reflected light from the observation target area that enters through the observation window 94 is captured by the imaging lens 23 of the endoscopic imaging device 20, and the optical path is bent at a right angle by the prism 27 (see FIG. 5), forming an image on the light receiving surface 25 a (see FIG. 5) of the imaging element 25 (see FIG. 5).

[0086] The bending portion 86 is remotely bent by rotating a pair of angle knobs 79c (see FIG. 9) provided on the operation portion 77 (see FIG. 9). This allows the distal rigid portion 85 to be oriented in a desired direction. Note that the bending portion 86 is made up of a plurality of bending pieces 97 and a plurality of bending operation wires 98 (two in FIG. 10). The distal ends of these bending operation wires 98 are connected to the bending pieces 97 and the proximal ends are connected to the pair of angle knobs 79c.

[0087] To efficiently and safely dissipate heat from the multiple ultrasonic transducers 92 and the backing material layer 112 transferred (thermally conducted) to the metal ring 90 to the distal bending piece 97 of the endoscope structure, an insulating heat-conducting member, i.e., an insulating heat-conducting member 120, is sandwiched between the metal ring 90, which is a heat-conducting member, and the distal bending piece 97. The insulating heat-conducting member 120 may be, for example, a heat-dissipating silicone rubber or a heat-dissipating sheet. Furthermore, if thermally conductive, a ceramic member, a heat-dissipating pad, or an insulating coating such as a DLC (diamond-like carbon) coating or a paraffin coating may also be used. The insulating heat-conducting member 120 preferably has a withstand voltage of 1.5 kV or higher. Furthermore, the distal bending piece 97 and the metal ring 90 are fixed to each other by resin screws 121, sandwiching a resin proximal ring 89 between them.

[0088] The ultrasonic signals for generating ultrasonic waves in the multiple ultrasonic vibrators 92 that make up the ultrasonic transducer 84 are generated and supplied by an ultrasonic processor 70 (see FIG. 9). Ultrasonic waves are emitted from the multiple ultrasonic vibrators 92 toward the observation target area. The ultrasonic processor 70 receives and acquires echo signals (reflected waves) reflected from the observation target area using the ultrasonic vibrators 92, and performs various signal processing on the acquired echo signals to generate an ultrasonic image. The generated ultrasonic image is displayed on a monitor 73 (see FIG. 9).

[0089] The observation target area is illuminated by illumination light from a light source device 72 (see FIG. 9) in the endoscopic observation section 83. The endoscope processor device 71 (see FIG. 9) receives and acquires image signals acquired from the observation target area, and performs various signal processing and image processing on the acquired image signals to generate an endoscopic image. The generated endoscopic image is displayed on a monitor 73 (see FIG. 9).

[0090] The nozzle (not shown) is connected to the distal end of an air / water supply conduit (not shown). The air / water supply conduit extends from the insertion section 76 to the operating section 77 and is inserted from the operating section 77 into a universal cord 78 (see FIG. 9 ). The proximal end of the air / water supply conduit is connected to a light source connector 80c (see FIG. 9 ). This connects the proximal end of the air / water supply conduit to the water tank 74 (see FIG. 9 ) via the connector 80c and an air / water supply tube 81 (not shown). Water in the water tank 74 is supplied from the air / water supply tube 81 through the connector 80c to the air / water supply conduit and sprayed from the nozzle toward the observation window 94 and the illumination window. Air from an air pump (not shown) is supplied to the air / water supply conduit, and the air is sprayed from the nozzle toward the observation window 94 and the illumination window via the air / water supply conduit.

[0091] Next, the balloon 100 will be described. An attachment groove 102 for attaching the base end side of the balloon 100 and an attachment groove 104 for attaching the tip end side of the balloon 100 are formed on the outer peripheral surface of the tip rigid portion 85. These attachment grooves 102, 104 are formed along the circumferential direction around the longitudinal axis A on the outer surface of the tip rigid portion 85.

[0092] A supply port (not shown) is formed on the outer surface of the rigid tip portion 85, between the mounting groove 102 and the mounting groove 104, for supplying water to the interior 100a of the balloon 100 and discharging water from the interior 100a of the balloon 100. The supply port is also formed between the mounting groove 102 and the ultrasonic transducer 84. The distal end of a balloon conduit (not shown) is connected to the supply port. The balloon 100 is made of an elastic material such as rubber. The balloon 100 has a ring-shaped band portion 106 at one end and a ring-shaped band portion 107 at the other end of the balloon 100. The band portion 106 is elastically attached to the mounting groove 102 of the rigid tip portion 85, and the band portion 107 is elastically attached to the mounting groove 104.

[0093] In particular, in the ultrasonic endoscope 13, voltage is input as an ultrasonic signal to generate ultrasonic waves to the multiple ultrasonic transducers 92, and therefore the distal cap 88 is made of an electrically insulating material. Therefore, when voltage is supplied to the ultrasonic transducers 92 to generate ultrasonic waves, the distal cap 88 is easily charged, and static electricity is generated due to the charging of the distal cap 88. The static electricity generated in the distal cap 88 flows to the holder 24. In this case, as described above, in the endoscopic imaging device 20, the second electrical resistance between the holder 24 and the connecting member 40 is smaller than the first electrical resistance between the holder 24 and the imaging element 25. Therefore, static electricity generated due to charging of at least one of the distal cap 88 and the proximal ring 89 flows preferentially between the holder 24 and the connecting member 40, which has a lower electrical resistance, than between the holder 24 and the imaging element 25. This makes it possible to suppress the flow of static electricity to the imaging element 25 in the ultrasonic endoscope 13, thereby protecting the imaging element 25 from static electricity. The static electricity that flows from the holder 24 to the connecting member 40 flows from the connecting member 40 to the shield layer 28c of the signal cable 28 via the connecting member 60, which electrically connects the connecting member 40 and the shield layer 28c of the signal cable 28. In this way, the effects of static electricity generated in the ultrasonic endoscope 13 can also be suppressed.

[0094] The present invention is basically configured as described above. Although the endoscopic imaging device, endoscope, and ultrasonic endoscope of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various improvements and modifications may be made without departing from the spirit and scope of the present invention.

[0095] 10, 10a Endoscope system 12 Endoscope 12a, 76a Tip portion 12b, 76b, 88a Tip surface 13 Ultrasonic endoscope 14, 72 Light source device 16 Processor device 20 Endoscope imaging device 22 Lens barrel 23 Imaging lens 24 Holder 24a Mounting tube portion 24b Flange portion 24d Regulating member 25 Imaging element 25a Light receiving surface 26 Circuit board 26a First flat portion 26b First bent portion 26c Second flat portion 26d Second bent portion 26e Third flat portion 26f, 26i Front surface 26g, 26h Back surface 27 Prism 27a Incident surface 27b Emitting surface 27c Inclined surface 27d Side surface 28 Signal cable 28a Signal line 28b Covering layer 28c Shield layer 28d Outer cover 28e Exposed portion 29 End portion 29a, 29b Tip 30, 30a Electronic component 31 Cover glass 34 Bump 35 Fixing member 40 Connecting member 40a Bottom portion 40b Holding portion 40c Arm portion 40d, 40h Opening 40e Edge 40f Cover portion 40g Gap 40j Rear end 40k, 40m Bent portion 40n Window portion 41 Engagement portion 41a Rear end 41b Tip 41c Narrow portion 41d Interior 50 Tip body 50a Surface 50b Through hole 60 Connecting member 61 Conductive wire 61a Extension portion 61b Curved portion 61c Connection portion 63 Terminal portion 64, 65 Solder 70 Ultrasonic processor 71 Endoscope processor 73 Monitor 74 Water tank 75 Suction pump 76 Insertion section 77 Operation section 78 Universal cord 79a Air / water supply button 79b Suction button 79c Angle knob 79d Treatment tool insertion port 80a, 80b, 80c Connector 81 Air / water supply tube 82 Suction tube 83 Endoscope observation section 84 Ultrasonic transducer 85 Hard tip section 86 Bending section 87 Flexible section 88 Tip cap 89 Base end ring 90 Metal ring 91 Forceps channel 92 Ultrasonic vibrator 92a Ultrasonic vibrator array 93 Treatment tool outlet 94 Observation window 95 Forceps pipe96 Forceps tube 97 Bending piece 98 Bending operation wire 100 Balloon 100a: Interior 102, 104 Mounting groove 106, 107 Band portion 110a Individual electrode 110b Common electrode 112 Backing material layer 113 Acoustic matching layer 114 Acoustic lens 115 Flexible wiring board 120 Insulating heat conducting member 121 Screw A Longitudinal axis C Optical axis

Claims

1. An endoscopic imaging device for acquiring an image of an observation object, a holder that holds an imaging lens directly or a lens barrel in which the imaging lens is provided; an imaging element that receives light that has passed through the imaging lens and performs photoelectric conversion; a signal cable electrically connected to the imaging element; a connecting member that connects the holder and the signal cable, the holder and the connecting member are made of a conductor, the signal cable includes a shielding layer that collectively covers a plurality of signal lines and an outer jacket that covers the outside of the shielding layer, and the outer jacket covers the shielding layer with an exposed portion at an end of the signal cable that is on the holder side; the signal cable is held by the connecting member, a tip of the exposed portion of the shielding layer on the holder side is closer to the holder than a tip of the outer jacket on the holder side, and the tip of the outer jacket is located closer to the holder than a rear end of the connecting member on the opposite side to the holder, the exposed portion of the shielding layer and the coupling member are electrically connected by a connecting member, a second electrical resistance between the holder and the connecting member is smaller than a first electrical resistance between the holder and the imaging element; An endoscopic imaging device, wherein the connecting member is joined to the connecting member outside the connecting member.

2. The connection member has a conductive wire, the conductive wire is wound around the outer circumferential surface of the exposed portion of the shield layer at least once, The endoscopic imaging device according to claim 1 , wherein the wound conductive wire is connected to the shield layer by soldering.

3. a circuit board electrically connected to the imaging element, the circuit board having a terminal portion; The endoscopic imaging device according to claim 2 , wherein the shield layer around which the conductive wire is wound and the terminal portion are electrically connected and fixed by soldering.

4. the connecting member has a narrow portion at a rear end opposite to the holder, the narrow portion having a length in a width direction perpendicular to the optical axis of the imaging lens that is shorter than the tip end on the holder side; The endoscopic imaging device according to claim 1 , wherein the connecting member is joined to the coupling member at the narrow portion.

5. 4. The endoscopic imaging device according to claim 1, further comprising a distal end body for fixing said holder or said lens barrel.

6. The endoscopic imaging device according to claim 5 , wherein the distal end body is made of resin.

7. Further, the optical element has a prism, The endoscopic imaging device according to claim 1 , wherein the holder and the imaging element are connected via the prism.

8. An endoscope comprising the endoscopic imaging device according to any one of claims 1 to 3.

9. An ultrasonic endoscope comprising the endoscopic imaging device according to claim 6.