Distal end part of endoscope, endoscope, and method for manufacturing distal end part of endoscope

Abstract

The present invention comprises: an imaging unit (40) for imaging in a second direction intersecting a first direction (AX) which is the longitudinal direction of an insertion part (2) of an endoscope (1); a holder (52) that has a first groove (52a) provided adjacent to the imaging unit and formed along the first direction, a second groove (52b) provided along the second direction and formed on the distal side of the first groove, and a third groove (52c) the proximal end of which is connected to the first groove and the distal side of which is connected to the second groove; a plurality of optical fibers (51) that have, in order from the proximal side, a first portion (51a), a bendable flexible portion (51c), and a second portion (51b), the first portion being disposed in the first groove, the second portion being fixed to the second groove with an adhesive (60), and the flexible portion being disposed in the third groove; and a gas that fills the third groove and comes into contact with the plurality of optical fibers.

Description

Endoscopic tip, endoscope, method for manufacturing an endoscopic tip

[0001] This invention relates to the internal structure of an endoscopic tip, an endoscope to which this tip is applied, and a method for manufacturing an endoscopic tip, and more particularly to the arrangement structure of a lighting unit disposed inside the tip of a side-viewing endoscope in a single-use endoscope.

[0002] Conventionally, endoscopes have been widely used in, for example, the medical field and industrial field. A medical endoscope used in the medical field includes a tip portion including an imaging unit, a lighting unit, etc., and a bending portion connected to this tip portion, and is configured to have an insertion portion having an overall elongated tube shape. Then, this insertion portion is inserted into the body cavity of a living body as a subject, and image data of an object (for example, a lesion portion, etc.) inside an organ or the like is acquired. The image data thus acquired is used for image diagnosis or the like by observing or inspecting the object (lesion portion, etc.).

[0003] As such a conventional form of an endoscope, for example, in addition to a direct-viewing endoscope that observes an object existing in the direction along the long axis of the insertion portion, a side-viewing endoscope that observes an object existing in the direction intersecting the long axis of the insertion portion, etc. are generally put into practical use.

[0004] Among these, in a side-viewing endoscope that includes a side region of the tip portion in the observation field, a configuration is adopted in which an observation window of the imaging unit and a lighting window of the lighting unit are arranged on the side surface of the tip portion. Here, in order to arrange the lighting window of the lighting unit on the side surface of the tip portion, a device is made to fix and arrange the optical fiber bundle (optical fiber band) of the lighting unit in a curved shape inside the tip portion.

[0005] With such a configuration, in a side-viewing endoscope, it is possible to irradiate illumination light toward an observation object existing in the side region of the tip portion, and to acquire image data of the observation object. Here, the optical fiber bundle refers to a form in which a plurality of optical fiber strands are bundled. This optical fiber bundle functions as a light guide (light guiding member) that guides light emitted from a light source device (not shown).

[0006] Incidentally, in conventional endoscopes, optical fiber bundles formed using glass optical fiber strands made from optical glass material have been put into practical use and are widely adopted, and are applied to the illumination unit.

[0007] Generally, fiber optic bundles made of glass fiber strands have the advantage of being particularly heat-resistant. For this reason, glass fiber strands are widely used in so-called reusable endoscopes, which are designed for repeated use after sterilization, disinfection, and cleaning in high-temperature and high-pressure environments. In this type of reusable endoscope, since sterilization, disinfection, and cleaning are assumed to be performed, measures are also needed to ensure that the area around the fiber optic bundle is waterproof.

[0008] Therefore, various configurations have been disclosed, for example in Japanese Patent Publication No. 61-219923, that can maintain the positioning and waterproof state of the tip region of the optical fiber bundle within the tip of a conventional side-viewing endoscope by devising the arrangement structure of the optical fiber bundle of the illumination unit at the tip.

[0009] The tip of a conventional side-viewing endoscope disclosed in the above-mentioned Japanese Patent Publication No. 61-219923, etc., is formed such that, for example, a through-hole is provided on the base end surface, an opening is provided on the side surface, and a space is provided inside through which the through-hole and the opening communicate.

[0010] In this case, the space has a continuous internal space region that extends from the through hole in a direction along the long axis, then curves and extends in a direction intersecting the long axis, and reaches an opening. Then, the optical fiber bundle is inserted and positioned along this internal space region, and then adhesive is filled into the gaps between the optical fiber bundle and the space.

[0011] With this configuration, the curved optical fiber bundle is positioned and fixed by adhesive within the internal space at its tip, while also ensuring waterproofing around the optical fiber bundle.

[0012] On the other hand, in recent years, efforts have been made to reduce the manufacturing costs of endoscopes and lower the price of products by using less expensive plastic optical fiber strands in the illumination units of endoscopes.

[0013] Japanese Patent Application Laid-open No. 61-219923

[0014] However, plastic optical fiber strands have problems with heat resistance, making them difficult to apply to reusable endoscopes that undergo sterilization, disinfection, and cleaning processes in high-temperature, high-pressure environments.

[0015] On the other hand, in recent years, in the field of medical endoscopes, so-called single-use endoscopes that are disposed of after a single use have been put into practical use and are becoming widely adopted, for example, due to considerations such as infection control.

[0016] This type of single-use endoscope eliminates the need for the post-use sterilization, disinfection, and cleaning procedures performed in conventional reusable endoscopes. Therefore, applying plastic optical fiber strands to the illumination unit of a single-use endoscope poses no problem, and its practical application is highly desirable.

[0017] However, when arranging a bundle of plastic optical fibers at the tip of an endoscope, it has been found that if the conventional configuration disclosed in Japanese Patent Publication No. 61-219923, etc., is applied as is, a problem arises in that a large amount of light loss occurs in the bending region of the optical fiber bundle (the region where adhesive is filled around it).

[0018] Specifically, in a configuration where adhesive is applied around the bent region of a plastic optical fiber bundle, if the refractive index of the adhesive is set to be higher than that of the cladding, the light guided by the core will leak out of the cladding, resulting in a loss of light intensity.

[0019] Furthermore, plastic optical fibers are thicker in diameter than glass optical fibers. Therefore, plastic optical fibers have greater resilience when bent. Consequently, when a bundle of plastic optical fibers is arranged inside the tip in a curved state, there is a tendency for variations in the arrangement and orientation of the tip surfaces of each optical fiber. This means that variations occur in the direction of the illumination light emitted from each optical fiber.

[0020] If the direction of light emission from each optical fiber strand varies, it can lead to a decrease in the light output of the lighting unit or prevent the desired light distribution characteristics from being achieved. Therefore, in order to stabilize the light output and light distribution characteristics of the lighting unit, it is necessary to precisely align the tip faces of each optical fiber strand to the desired positions.

[0021] The present invention aims to provide a single-use endoscope, particularly a tip of a side-viewing endoscope, that ensures good optical performance of the illumination unit (such as desired light intensity and optimal light distribution characteristics), while also providing good assembly workability and appropriate placement of the illumination unit, by devising a structure for arranging an illumination unit made of plastic optical fiber strands inside the tip of the endoscope, the endoscope, and a method for manufacturing the tip of the endoscope.

[0022] To achieve the above objective, the tip of an endoscope according to one aspect of the present invention comprises: an imaging unit that images a second direction intersecting a first direction which is the longitudinal direction of the insertion portion of the endoscope; a holder provided adjacent to the imaging unit and having a first groove formed along the first direction, a second groove provided along the second direction and formed distal to the first groove, and a third groove whose proximal end is connected to the first groove and distal end is connected to the second groove; a plurality of optical fibers having, in order from the proximal end, a first portion, a bendable flexible portion, and a second portion, wherein the first portion is placed in the first groove, the second portion is fixed in the second groove with adhesive, and the flexible portion is placed in the third groove; and a gas that fills the third groove and comes into contact with the plurality of optical fibers.

[0023] An endoscope according to one aspect of the present invention includes: an imaging unit that images a second direction intersecting a first direction which is the longitudinal direction of the insertion portion of the endoscope; a holder provided adjacent to the imaging unit and having a first groove formed along the first direction, a second groove provided along the second direction and formed distal to the first groove, and a third groove whose proximal side is connected to the first groove and whose distal side is connected to the second groove; a plurality of optical fibers having, in order from the proximal side, a first portion, a bendable flexible portion, and a second portion, wherein the first portion is arranged in the first groove, the second portion is fixed in the second groove with adhesive, and the flexible portion is arranged in the third groove; and a gas that fills the third groove and comes into contact with the plurality of optical fibers.

[0024] A method for manufacturing the tip of an endoscope according to one aspect of the present invention involves arranging an imaging unit to image in a second direction intersecting a first direction which is the longitudinal direction of the insertion portion of the endoscope; arranging a plurality of optical fibers in a holder having a first groove provided along the first direction, a second groove provided along the second direction and located distal to the first groove, and a third groove whose proximal side is connected to the first groove and whose distal side is connected to the second groove; maintaining a state in which the flexible portion of the plurality of optical fibers arranged in the third groove is in contact with a gas; bonding and fixing the plurality of optical fibers to the second groove with an adhesive; and arranging the holder adjacent to the imaging unit.

[0025] The tip of an endoscope according to another aspect of the present invention comprises: an optical fiber bundle having a first row in which at least two optical fibers are arranged side by side and a second row having at least one optical fiber arranged adjacent to the first row; a holder having a first groove provided along a first direction, a second groove provided along a direction intersecting the first direction and provided distal to the first groove, and a third groove whose proximal side is connected to the first groove and whose distal side is connected to the second groove, wherein the optical fiber bundle is arranged in the first groove, the second groove and the third groove; a flat portion formed in the second groove, to which the side surfaces of the tips of at least two optical fibers of the first row abut; an adhesive provided in the second groove proximal to the flat portion along the longitudinal axis of the optical fiber bundle, for fixing the optical fiber bundle to the holder; and a bending portion which is a part of the optical fiber bundle and is arranged in the third groove, and the restoring force generated by bending the optical fiber bundle presses the side surfaces of the tips of at least two optical fibers of the first row against the flat portion.

[0026] According to the present invention, it is possible to provide a single-use endoscope, particularly a tip of a side-viewing endoscope, that ensures good optical performance of the illumination unit (such as desired light intensity and optimal light distribution characteristics), while also providing good assembly workability and appropriate placement of the illumination unit, by devising a structure for arranging an illumination unit made of plastic optical fiber strands inside the tip of the endoscope, an endoscope, and a method for manufacturing the tip of the endoscope.

[0027] Figure 10 shows a schematic external perspective view of the entire endoscope, including the tip of the endoscope, an exploded perspective view of the endoscope tip of Figure 1, an enlarged perspective view of only the tip components of the endoscope tip of Figure 1, a perspective view mainly showing the base end of the tip components of Figure 4, a front view showing the base end surface of the tip components of Figure 4, an enlarged longitudinal section view of the main part of the tip of the endoscope tip of Figure 1, an enlarged cross-sectional view of the main part of the tip of the endoscope tip of Figure 1, an enlarged exploded perspective view of the main part showing the lifting platform and lifting wire provided at the tip of the endoscope tip of Figure 1, a partially exploded perspective view showing only the illumination unit provided at the tip of the endoscope tip of Figure 1 with some components (illumination lens) disassembled, an enlarged side view of the illumination unit of Figure 9, and the direction of arrow Y1 in Figure 10. Figure 15 shows a simplified plan view of the plane as seen from the front, a first modified example of the lighting unit, a simplified plan view of the lighting unit when it is configured with nine optical fiber bundles as seen from the direction of arrow Y1 in Figure 10, a second modified example of the lighting unit, a simplified plan view of the lighting unit when it is configured with three optical fiber bundles as seen from the direction of arrow Y1 in Figure 10, a schematic diagram showing in chronological order the process of heat-treating the exit end faces of the optical fiber bundles using a heated mirror plate, a conceptual diagram showing the configuration of the connection part between the endoscope and the processor in this embodiment, a diagram conceptually showing the connection state between the optical fiber bundle on the connector side and the optical fiber bundle on the adapter side in Figure 15, showing the state in which the connector and adapter are disconnected. A diagram showing the state in which the connector and adapter are connected after the state in Figure 16.

[0028] The present invention will be described below with reference to the illustrated embodiments. The drawings used in the following description are schematic. Therefore, in these drawings, each component is shown at a size that is recognizable on the drawing. For this reason, the dimensional relationships and scales of each component may differ on the drawing. The present invention is not limited to the illustrated forms with respect to the quantity, shape, size ratio, relative positional relationships, etc., of each component shown in each drawing.

[0029] First, before describing in detail the tip of the endoscope according to one embodiment of the present invention, the overall configuration of the endoscope, including this tip, will be briefly described below using Figure 1 and other figures.

[0030] Figure 1 is an external perspective view showing the schematic configuration of the entire endoscope, including the tip of the endoscope, according to one embodiment of the present invention. Figure 2 is an exploded perspective view showing the tip of the endoscope in Figure 1 in an exploded state. Figure 3 is an enlarged perspective view showing only the tip components of the endoscope in Figure 1. Figure 4 is a perspective view mainly showing the base end side of the tip components in Figure 4. Figure 5 is a front view showing the base end side surface of the tip components in Figure 4. Figure 6 is an enlarged longitudinal cross-sectional view of the main part of the tip of the endoscope in Figure 1. Figure 7 is an enlarged transverse cross-sectional view of the main part of the tip of the endoscope in Figure 1. Figure 8 is an enlarged exploded perspective view showing the lifting platform and lifting wire provided at the tip of the endoscope in Figure 1 in an exploded state. Figure 9 is a partially exploded perspective view showing only the illumination unit provided at the tip of the endoscope in Figure 1, with some components (illumination lens) disassembled. Figure 10 is an enlarged side view of the illumination unit in Figure 9. Figure 11 is a simplified plan view showing the plane as seen from the direction of arrow Y1 in Figure 10. Figure 12 shows a first modified example of the lighting unit, a simplified plan view of the lighting unit with nine optical fiber bundles, as seen from the direction of arrow Y1 in Figure 10. Figure 13 shows a second modified example of the lighting unit, a simplified plan view of the lighting unit with three optical fiber bundles, as seen from the direction of arrow Y1 in Figure 10. Note that the pressing jig is also shown in Figures 11, 12, and 13. Figure 14 is a schematic diagram showing the process of heat-treating the exit end faces of the optical fiber bundles using a heated mirror plate, arranged in chronological order.

[0031] Endoscope 1 is an insertion device that has a portion for insertion into a subject. The subject may be a living organism such as a person or animal, or a non-living object such as a machine or building.

[0032] Endoscope 1 is configured, for example, as a single-use device and is disposed of after a single use; that is, it is collected by the manufacturer or recycling company after one use and then disassembled or disposed of.

[0033] The endoscope 1 comprises an insertion section 2, an operating section 3, and a universal cable 4. The endoscope 1 is configured, for example, as a side-viewing type electronic endoscope.

[0034] The insertion portion 2 is a part configured to be inserted into the subject. The insertion portion 2 is formed along the longitudinal axis AX.

[0035] Here, the direction along the longitudinal axis AX is the longitudinal direction of the insertion portion 2. In the following description, the longitudinal direction of the insertion portion 2 (the direction along the longitudinal axis AX; see Figure 1) will be referred to as the first direction. Furthermore, among the directions intersecting the first direction (longitudinal axis AX), the direction in which the lifting base 30 (described later) at the tip portion 5 rises will be referred to as the second direction.

[0036] The insertion portion 2 comprises, in order from the tip end to the base end, a tip portion 5, a curved portion 6, and a flexible tube portion 7.

[0037] As will be described later, the tip section 5 is equipped with a lifting platform 30, an imaging unit 40, an illumination unit 50 (see Figure 2, etc.), and the like.

[0038] The curved section 6 is a part that can be actively curved in any two directions, for example, up and down or left and right, or in four directions: up, down, left, and right. Here, the four directions of up, down, left, and right refer to the directions perpendicular to the longitudinal axis AX (first direction), in which the lifting base 30 at the tip section 5 rises (second direction), which is called the up direction. Of these, the side on which the observation window, illumination lens, etc. are arranged is considered the up direction, with the longitudinal axis AX as the reference, and the direction opposite to this up direction is considered the down direction.

[0039] Furthermore, among the directions perpendicular to the longitudinal axis AX (first direction), the direction perpendicular to the direction in which the lifting platform 30 is raised (second direction) (the width direction of the tip portion 5) is referred to as the left-right direction. Of these, when viewing the tip portion 5 from the base end side to the tip end side with the longitudinal axis AX as the reference, the side where the observation window, illumination lens, etc. are arranged is referred to as the left direction, and the direction opposite to the left direction (the side where the lifting platform 30 is arranged) is referred to as the right direction.

[0040] The flexible tube section 7 is a tubular section that is flexible. Here, we give an example where the endoscope 1 is a flexible endoscope having a flexible tube section 7. However, the endoscope 1 may also be a rigid endoscope in which the part corresponding to the flexible tube section 7 is rigid.

[0041] The operation unit 3 is disposed on the proximal end side of the insertion unit 2. The operation unit 3 is a part for the user to operate the endoscope 1. The operation unit 3 includes a gripping unit 8, a treatment tool insertion port 9, a bending operation knob 10, a plurality of operation buttons 11, and a treatment tool lifting lever 12.

[0042] The gripping unit 8 is a part where the user grips the endoscope 1 with the palm.

[0043] The treatment tool insertion port 9 is an opening on the proximal end side of the treatment tool channel. A treatment tool (not shown) such as forceps is inserted into the treatment tool channel from the treatment tool insertion port 9. The tip of the treatment tool is guided into a storage chamber 26 (see FIG. 2 etc.) communicating with the distal end side of the treatment tool channel. The tip of the treatment tool is placed on a lifting table 30 provided in the storage chamber 26 and protrudes into the subject. Various treatments on the subject are performed using the protruding tip of the treatment tool.

[0044] The bending operation knob 10 is an operation device for operating the bending of the bending unit 6. The bending operation knob 10 is operated, for example, using the thumb of the hand gripping the gripping unit 8. When the bending operation knob 10 is operated, a bending operation wire (not shown) is pulled, and the bending unit 6 is bent.

[0045] When the bending unit 6 is bent, the direction of the distal end portion 5 changes. Then, the imaging direction by the imaging unit 40 and the irradiation direction of the illumination light from the illumination unit 50 change. Also, the bending unit 6 is bent to improve the insertability of the insertion unit 2 in the subject.

[0046] The plurality of operation buttons 11 include, for example, an air / water supply button, a suction button, and buttons related to imaging.

[0047] The air / water supply button is a button for the operation of supplying air and water to an observation window provided on the front end surface of the imaging unit 40 at the distal end portion 5. The observation window is cleaned by liquid supply, and the liquid after cleaning is wiped off by air supply. Air supply and water supply are performed via an air / water supply channel.

[0048] The suction button is a button for the operation of sucking from the tip portion 5 into the subject. The suction from the subject is performed, for example, via a treatment tool channel that also serves as a suction channel. When the suction operation is performed, for example, liquid or mucosa is sucked from the subject.

[0049] The button related to imaging is, for example, a button switch for the release operation.

[0050] The treatment tool raising lever 12 is a lever for operating the raising and inversion of the raising table 30 (see Fig. 2 etc.) inside the tip portion 5.

[0051] The universal cable 4 extends from the side surface, for example, on the proximal end side of the operation unit 3. A connector 13 is provided at the extending end of the universal cable 4. The connector 13 connects the endoscope 1 to a processor, a light source device, a suction pump, a water supply tank, etc., not shown.

[0052] Note that, as an example of the light source device in the endoscope 1, a configuration example in which it is an external device connected through the connector 13 is illustrated, but it is not limited to this configuration example. As a configuration example of the light source device, separately from the above configuration example, for example, a light source device using an LED or the like may be arranged inside the operation unit 3.

[0053] Next, the configuration of the tip portion 5 of the endoscope 1 will be described below. The tip portion 5 includes a tip configuration member 20, a raising table 30, an imaging unit 40, a lighting unit 50, a light guide cover 61, and a tip cover 62.

[0054] A treatment tool insertion tube 14, a fluid tube 15, and a raising sheath 16 are connected to the tip configuration member 20.

[0055] The treatment tool insertion tube 14 has a treatment tool channel formed inside the tube, and a treatment tool is inserted therethrough. The treatment tool insertion tube 14 is connected to a through hole 25 (see Fig. 4, Fig. 5, etc.) provided in the tip configuration member 20.

[0056] The fluid tube 15 has a gas supply and water supply channel formed inside the tube, and fluid (for example, gas such as air or liquid such as physiological saline) is sent therethrough.

[0057] The tip component 20 is equipped with a storage chamber 26 for housing the lifting base 30. The through hole 25 communicates with the storage chamber 26. Therefore, the treatment instrument inserted through the treatment instrument insertion tube 14 is guided through the through hole 25 to the lifting base 30 stored in the storage chamber 26.

[0058] The storage chamber 26 is connected to the outside, and the lifting platform 30 can be raised toward the outside. The lifting platform 30 is made of resin. By forming the lifting platform 30 from resin, the manufacturing cost of the lifting platform 30 can be reduced compared to when it is formed by cutting metal.

[0059] A lifting wire 17 is connected to the lifting platform 30. The lifting wire 17 is inserted through the lifting sheath 16 and mechanically connected to the treatment instrument lifting lever 12 (see Figure 1). When the treatment instrument lifting lever 12 is operated, the lifting wire 17 is pulled. By pulling the lifting wire 17, the lifting platform 30 is displaced in a direction intersecting the longitudinal axis AX, changing the direction in which the treatment instrument (not shown) is guided.

[0060] The tip component 20 has an imaging aperture 27. An observation window 43 and a portion of the imaging unit 40 in which the imaging lens 41 is located are fitted into the imaging aperture 27. The imaging lens 41 is constructed, for example, by stacking multiple lenses (see Figure 6, etc.).

[0061] The observation window 43 is made of a cover glass or the like that protects the imaging lens 41, and light from the subject enters it. The optical axis OA (see Figure 6) of the imaging lens 41 and the observation window 43 is set to be tilted at a slight angle (greater than 90° with respect to the tip direction of the longitudinal axis AX) toward the proximal end with respect to the orthogonal direction of the direction that intersects the longitudinal axis AX (the second direction). With this configuration, the imaging unit 40 images the second direction that intersects the first direction (the direction along the longitudinal axis AX), which is the longitudinal direction of the insertion part 2 of the endoscope 1.

[0062] The optical axis OA of the observation window 43 intersects the central axis O of the conduit 21 when the central axis O of the conduit 21 is extended (see Figure 6). In particular, the position of the observation window 43 and the conduit 21 is optimized so that the end face on the base side of the observation window 43 intersects the extension of the central axis O of the conduit 21.

[0063] By adopting this configuration, the fluid discharged from the pipeline 21 flows from the base end of the observation window 43 along the entire surface of the observation window 43. In this way, the entire observation window 43 is properly cleaned, ensuring cleanability.

[0064] In this embodiment, an example is described in which an observation window 43 is provided on the outside of the imaging lens 41. However, the optical performance of the imaging lens 41 is not significantly impaired during the single use of the endoscope 1. For this reason, if the endoscope 1 is a single-use type, the observation window 43 may be omitted. By omitting the observation window 43, the number of parts can be reduced, and manufacturing costs can be further suppressed.

[0065] The imaging unit 40 has an image sensor 42 at a position where an optical image of the subject is formed by the imaging lens 41 (see Figure 6). The image sensor 42 generates an imaging signal by photoelectric conversion (imaging) of the optical image of the subject. Examples of the image sensor 42 include, but are not limited to, a CCD (Charge Coupled Device) image sensor and a CMOS (Complementary Metal-Oxide Semiconductor) image sensor. An imaging cable 18 is connected to the imaging unit 40. The imaging signal generated by the image sensor 42 is transmitted to a processor (not shown) via the imaging cable 18.

[0066] The tip component 20 has an illumination opening 28 into which the illumination lens 53 of the illumination unit 50 is fitted. The illumination unit 50 is connected to an optical fiber bundle 51 that passes through the inside of the light guide cable 19.

[0067] The lifting platform 30, imaging unit 40, and lighting unit 50 are incorporated into the tip component 20. A light guide cover 61 is attached to the tip component 20, which incorporates the lifting platform 30, imaging unit 40, and lighting unit 50, from below, and a tip cover 62 is attached from the tip side.

[0068] The tip cover 62 has a first opening 62a on the base end side and a second opening 62b on the upper side (the side in a second direction intersecting the longitudinal axis AX). The first opening 62a is an opening for inserting the tip end of the tip component 20 into the tip cover 62 in a first direction along the longitudinal axis AX. The second opening 62b is an opening that allows light from the subject to enter the imaging unit 40, illuminates the subject with illumination light from the illumination unit 50, and allows the lifting platform 30 to rise and the tip of the treatment instrument to protrude.

[0069] The tip component 20 has a conduit 21 formed as a through-hole that penetrates the tip component 20. The tip of the connecting pipe 15a is inserted into the base end of the conduit 21. The fluid tube 15 is connected to the base end of the connecting pipe 15a. By using the connecting pipe 15a, the process of connecting the fluid tube 15 to the conduit 21 can be easily carried out.

[0070] With this configuration, the fluid supplied from the fluid tube 15 flows into the pipeline 21 via the connecting pipe 15a, and the fluid flowing in the pipeline 21 comes into direct contact with the tip component 20.

[0071] As shown in Figure 7, the central axis O of the conduit 21 is not parallel to the longitudinal axis AX of the insertion section 2, nor does it intersect with the longitudinal axis AX of the insertion section 2 (at the tip side). Specifically, as shown in Figure 7, the conduit 21 is arranged at an angle such that the central axis O approaches the side as it approaches the tip.

[0072] Furthermore, the tip component 20 has a through hole 24 (Figures 4, 5, and 7) into which the tip of the lifting sheath 16 is inserted.

[0073] The lifting platform 30 has a pivot axis RA (see Figures 2 and 8). The lifting platform 30 rotates and displaces around the pivot axis RA while stored in the storage chamber 26.

[0074] As shown in Figures 2 and 3, a regulating member 23 is integrally provided on the tip component 20. The regulating member 23 contacts the lifting base 30 when the lifting base 30 rotates and is in the raised position, and defines the angle at which the lifting base 30 is raised. Although not shown in the figures, a structure that defines the angle when the lifting base 30 is inverted is also integrally provided on the tip component 20.

[0075] Since the tip component 20 is made of resin, the restricting member 23 is also made of resin. By integrally providing the restricting member 23 with the tip component 20, the number of parts can be reduced, and the process of attaching the restricting member 23 to the tip component 20 can be omitted, thereby suppressing manufacturing costs.

[0076] In the above-described configuration example, the restricting member 23 is integrally attached to the tip component 20, which is made of resin, but the invention is not limited to this. For example, the restricting member 23 may be formed as a separate component from ceramic or the like and attached to the tip component 20.

[0077] As shown in Figure 8 and other figures, the tip of the lifting wire 17 is fixed to the shaft portion 39a of the wire stopper 39 by a crimping process. The wire stopper 39 has a shaft portion 39a and a head portion 39b provided on the tip side of the shaft portion 39a. The head portion 39b has a larger diameter than the shaft portion 39a.

[0078] The lifting base 30 has a through hole 31 having an axis CA parallel to the pivot axis RA. The lifting wire 17 is inserted through the through hole 31 from the base end, and after the lifting wire 17 has been inserted, the wire stopper 39 to which the tip of the lifting wire 17 is fixed is inserted. Then, the large-diameter head 39b prevents the wire stopper 39 from coming out of the through hole 31.

[0079] Alternatively, the wire stopper 39 may be inserted through the through hole 31 by itself, and then the tip of the lifting wire 17 may be fixed to the shaft portion 39a of the wire stopper 39.

[0080] Furthermore, if the endoscope 1 is a single-use type, the reprocessing treatment performed on reusable endoscopes is unnecessary. Therefore, when inserting the wire stopper 39 through the through hole 31, an O-ring or the like is not provided between the through hole 31 and the wire stopper 39, which simplifies the waterproofing function.

[0081] The lifting platform 30 is raised or lowered by pulling or releasing the lifting wire 17, with the pivot axis RA as the fulcrum and axis CA as the point of force application.

[0082] In the above-described configuration example, a lifting platform 30 that rotates around the pivot axis RA to raise itself was illustrated. However, a lifting platform 30 that is raised by an elastic member such as a spring may also be used, in addition to this configuration example.

[0083] As shown in Figures 6, 9, and 10, the lighting unit 50 includes an optical fiber bundle 51, a light guide holder 52, and an illumination lens 53.

[0084] The optical fiber bundle 51 is an optical fiber bundle (optical fiber bundle) formed by bundling together multiple optical fiber strands (plastic) made of, for example, plastic resin.

[0085] Plastic optical fibers are thicker in diameter than glass optical fibers and have a strong restorative force that causes them to return to their original shape when bent. In addition to these properties, plastic optical fibers are cheaper than glass optical fibers, so adopting plastic optical fibers can be expected to reduce the cost of lighting units and endoscopes that use them.

[0086] Therefore, in this embodiment, the optical fiber bundle 51 is configured as a resin fiber bundle, which is made by bundling together multiple strands of transparent resin fiber (plastic).

[0087] In this embodiment, the optical fiber bundle 51 applied to the tip portion 5 of the endoscope 1 is composed of individual optical fiber strands with an outer diameter of, for example, 0.2 mm to 0.8 mm.

[0088] The light guide holder 52 is a holding member (holder) for holding the optical fiber bundle 51 and fixing it in a predetermined shape. The light guide holder 52 is located inside the tip portion 5, adjacent to the imaging unit 40.

[0089] The light guide holder 52 has a first groove 52a provided along a first direction along the longitudinal axis AX, a second groove 52b provided along a second direction intersecting the longitudinal axis AX and located distal to (towards the tip) the first groove 52a, and a third groove 52c whose proximal end (base end) is connected to the first groove 52a and whose distal end (tip end) is connected to the second groove 52b.

[0090] These first groove 52a, second groove 52b, and third groove 52c open toward one side of the light guide holder 52 (the surface exposed in Figures 9 and 10).

[0091] Furthermore, the first groove 52a, the second groove 52b, and the third groove 52c are formed continuously so that the optical fiber bundle 51 can be inserted and arranged through them, as will be described later. The first groove 52a, the second groove 52b, and the third groove 52c have a substantially rectangular cross-sectional shape perpendicular to the longitudinal axis AX. In this case, it is sufficient that at least the cross-sectional shape of the second groove 52b is substantially rectangular. Generally, a rectangle means a quadrilateral in which two opposite sides are parallel and all four angles are 90 degrees. The substantially rectangular shape referred to here includes not only general rectangles but also shapes in which only the corners differ from a rectangle, such as circular arcs or tapered shapes, instead of the four corners of a rectangle.

[0092] Furthermore, in the light guide holder 52, a first opening 52e is formed at the base end of the first groove 52a, oriented in a direction along the longitudinal axis AX. A second opening 52f is formed at the tip end of the second groove 52b, oriented in a direction substantially perpendicular to the longitudinal axis AX.

[0093] As described above, the optical fiber bundle 51 consists of multiple optical fiber strands. In this embodiment, the optical fiber bundle 51 is shown as being composed of, for example, four optical fiber strands bundled together (see Figure 11, etc.), but it is not limited to this example, and it is sufficient if it is composed of two or more optical fiber strands bundled together.

[0094] As described above, the endoscope 1 illustrated in this embodiment is a side-viewing type. Therefore, as shown in Figures 6, 9, and 10, the optical fiber bundle 51 in the side-viewing endoscope 1 is fitted into predetermined areas (grooves 52a, 52b, and 52c) of the light guide holder 52 with a portion of its tip bent.

[0095] Here, the optical fiber bundle 51 has, in order from the proximal side (root end side), a first portion 51a, a flexible portion 51c which is a bendable portion, and a second portion 51b.

[0096] The first portion 51a is positioned in the first groove 52a. The second portion 51b is positioned in the second groove 52b and fixed by adhesive 60 (see Figure 10). The flexible portion 51c is positioned in the third groove 52c.

[0097] Here, it is preferable that the flexible portion 51c is set to, for example, a radius of curvature R of about 1.0 to 5.5 mm.

[0098] Furthermore, in this case, a gap exists between the third groove 52c and the outer surface of the flexible portion 51c that is positioned within the third groove 52c. That is, the third groove 52c is filled with gas. Therefore, the flexible portion 51c positioned within the third groove 52c is in an environment exposed to gas.

[0099] Furthermore, if light leakage occurs from the flexible portion 51c, this may result in a decrease in illumination light intensity. As a measure to suppress such a decrease in light intensity due to light leakage, for example, a reflective coating of silver, aluminum, or the like may be applied to the outside of the cladding of the optical fiber strands. Such a reflective coating may be applied to the entire length of the optical fiber strands, or it may be applied to a part of the optical fiber strands, such as the flexible portion, where light leakage is particularly likely to occur.

[0100] In addition to the above configuration, the first portion 51a may also be fixed using adhesive 60 when positioned in the first groove 52a (see the area indicated by the dotted line in Figure 10).

[0101] The adhesive 60 used to bond and fix the optical fiber bundle 51 is, specifically, an ultraviolet-curing or thermosetting epoxy adhesive.

[0102] The adhesive is preferably one whose viscosity, as measured by a Type B viscometer at a rotation speed of 100 rpm in a 23-degree Celsius environment, is 250 to 4000 mPa·s, and whose thixotropic ratio is 3.0 to 8.0.

[0103] Here, the adhesive 60 fixes the second portion 51b positioned in the second groove 52b, as described above. In this case, a portion of the adhesive 60 may protrude from the base end of the second portion 51b and adhere to the flexible portion 51c. In this case, it is desirable that the allowable range of adhesive 60 protruding onto the flexible portion 51c be within 30% of the axial length of the flexible portion 51c.

[0104] Similarly, with respect to the adhesive 60 that fixes the first portion 51a positioned in the first groove 52a, it is permissible for it to protrude up to 30% of the axial length relative to the flexible portion 51c.

[0105] As described above, the second portion 51b of the optical fiber bundle 51 is positioned in the second groove 52b. At this time, the tip of the second portion 51b of the optical fiber bundle 51 is positioned in a manner that is tilted backward (towards the base end) by a predetermined angle θ2 (see Figure 10) with respect to the direction perpendicular to the longitudinal axis AX (arrow Y direction in Figure 10).

[0106] In this case, the angle θ2 is defined by the shape of the second groove 52b of the light guide holder 52, as shown in Figure 10. Furthermore, the tip region of the second portion 51b of the optical fiber bundle 51 is defined by the position of the second groove 52b of the light guide holder 52.

[0107] Here, the first direction (longitudinal axis AX) can be defined as the direction in which the first portion 51a of the optical fiber bundle 51 extends. The second direction includes the raising direction of the support base 30 and is a direction that intersects the longitudinal axis AX. In the configuration example of this embodiment, as shown in Figure 10, it refers to the inclination direction of the second portion 51b of the optical fiber bundle 51.

[0108] Therefore, in the configuration example of this embodiment, it is preferable to set the first direction and the second direction to intersect at an angle of approximately 60 to 100 degrees. Here, the intersection angle of the first direction and the second direction corresponds to the angle θ1 shown in Figure 10.

[0109] Furthermore, when the first portion 51a of the optical fiber bundle 51 is positioned in the first groove 52a, the second portion 51b is positioned in the second groove 52b, and the flexible portion 51c is positioned in the third groove 52c (see the state shown in Figure 10), the optical fiber bundle 51 is subjected to a force due to the restoring force of the flexible portion 51c, in a direction along the longitudinal axis AX and along the arrow X1 shown in Figure 10.

[0110] To this end, a flat portion 52g is formed on the inner surface of the tip region of the second groove 52b, which abuts against one side surface 51g of the tip region of the second portion 51b of the optical fiber bundle 51. As a result, one side surface 51g of the tip region of the second portion 51b of the optical fiber bundle 51 abuts against the flat portion 52g on the inner surface of the tip region of the second groove 52b and is pressed with a predetermined force by the restoring force of the flexible portion 51c. As a result, the tip region of the second portion 51b of the optical fiber bundle 51 is positioned within the tip region of the second groove 52b. Then, the second portion 51b, positioned in this state, is bonded and fixed within the second groove 52b with adhesive 60.

[0111] In other words, the flexible portion 51c, which is the bent part of the optical fiber bundle 51, is positioned in the third groove 52c, and the restoring force generated by bending the optical fiber bundle 51 presses one side surface 51g of the tip of at least two optical fiber strands (first row; see Figure 11) against the flat portion 52g.

[0112] Here, the adhesive 60 is provided in the second groove 52b located proximal (towards the base end) to the planar portion 52g along a second direction intersecting the longitudinal axis AX of the optical fiber bundle 51, and fixes the optical fiber bundle 51 to the light guide holder 52 (the second groove 52b).

[0113] In this case, the optical fiber bundle 51 has at least two optical fiber strands with one side surface 51g in contact with the flat portion 52g. In other words, the flat portion 52g is formed in the second groove 52b, and the ends of at least two optical fiber strands (first row) have one side surface 51g in contact with it.

[0114] In this embodiment, the optical fiber bundle 51 is formed by having four optical fiber strands, as described above. In this case, the optical fiber bundle 51 comprises a first row in which two optical fiber strands are arranged side by side, and a second row adjacent to the first row in which two optical fiber strands are arranged side by side (see Figure 11). Of these, one side surface 51g of the two optical fiber strands in the first row is in contact with the flat portion 52g (see Figure 11).

[0115] In order to ensure and maintain such a configuration, it is necessary that the multiple optical fiber strands in the region from the flexible portion 51c to the second portion 51b are arranged without twisting and that the positional relationship between each strand does not change.

[0116] Furthermore, the optical fiber bundle 51 is not limited to a configuration of four optical fiber strands; it can consist of multiple strands. For example, the optical fiber bundle 51 can have a configuration of three strands or nine strands.

[0117] Here, for example, if the optical fiber bundle 51 is composed of four strands as described above, then at least the multiple optical fiber strands in the region from the flexible portion 51c to the second portion 51b are arranged in two columns and two rows (see Figure 11).

[0118] Furthermore, for example, if the optical fiber bundle 51 consists of nine strands, as shown in Figure 12, the configuration should be such that there is a first row in which three optical fiber strands are arranged side by side, a second row in which three optical fiber strands adjacent to the first row are arranged side by side, and a third row in which three optical fiber strands adjacent to the second row are arranged side by side (3 rows and 3 columns), and one side surface 51g of the three optical fiber strands in the first row is in contact with the flat portion 52g.

[0119] Furthermore, for example, when the optical fiber bundle 51 is configured with three strands, as shown in Figure 13, the three strands are arranged in a roughly equilateral triangle by forming a first row in which two optical fiber strands are arranged vertically, and a second row in which one optical fiber strand is arranged adjacent to the first row. Accordingly, a protrusion 52j is provided in a part of the flat portion 52g that projects inward toward the second groove 52b. In this case, the inward-facing wall surface of the protrusion 52j is defined as the flat portion 52hg. Then, one side surface 51g1 of the first row of optical fiber strands is brought into contact with the flat portion 52g, and one side surface 51g2 of the second row of optical fiber strands is brought into contact with the flat portion 52hg. With this configuration, the three-strand optical fiber bundle 51 can be stably arranged inside the second groove 52b by receiving the restoring force of the flexible portion 51c.

[0120] Thus, the optical fiber bundle 51 comprises a first row in which at least two optical fiber strands are arranged side by side, and a second row adjacent to the first row having at least one optical fiber strand. Note that the configuration is slightly different in the case of a three-strand configuration.

[0121] Furthermore, as shown in the figures, in optical fiber bundles 51 with four strands (see Figure 11) or nine strands (see Figure 12), it is preferable to have the same number of optical fiber strands in the first row (two or three) as the number of optical fiber strands in the second row (two or three). Such a configuration is made easier by making the cross-sectional shape of the second groove 52b rectangular.

[0122] With this configuration, the force generated by the restoring force of the flexible portion 51c is applied equally to approximately the center of each optical fiber strand. This prevents the load on each optical fiber strand from becoming unevenly distributed.

[0123] Incidentally, in the state described above, where the second portion 51b of the optical fiber bundle 51 is positioned in the second groove 52b, the optical fiber bundle 51 is in a state where one side surface 51g is in contact with and pressed against the flat portion 52g due to the restoring force of the flexible portion 51c in the direction of arrow X1 in Figure 11.

[0124] In this case, if there is a gap between the optical fiber bundle 51 and, for example, the other plane 52h within the second groove 52b, it cannot be said to be in a stable state.

[0125] Therefore, in this embodiment, by using a pressing jig 100 as shown in Figures 11 to 13, the gap between the optical fiber bundle 51 in the second groove 52b and the other plane 52h is eliminated.

[0126] As shown in Figure 11, the pressing jig 100 has a convex portion 100a that can engage with the side opening 52k of the second groove 52b. This convex portion 100a is a W-direction position adjustment jig that, when inserted from the side opening 52k of the second groove 52b in the direction of arrow W1 in Figure 11, presses the second portion 51b (the tip region) of the optical fiber bundle 51, which is positioned in the second groove 52b, in the same W1 direction, thereby bringing the side portion 51h of the optical fiber bundle 51 into contact with the other plane 52h.

[0127] By using this pressing jig 100, the optical fiber bundle 51 can be stably positioned within the second groove 52b. Then, in this state, the second portion 51b of the optical fiber bundle 51 is fixed in the second groove 52b by applying adhesive 60 to a predetermined area of ​​the second portion 51b.

[0128] Furthermore, it is desirable that the leading surface of the optical fiber bundle 51, which is the end surface from which the illumination light is emitted, is formed to be substantially flush with a predetermined surface of the light guide holder 52 when in this state. To achieve this, for example, first, the optical fiber bundle 51 is assembled to the light guide holder 52 as shown by reference numeral [14A] in Figure 14. In this state, the second portion 51b of the optical fiber bundle 51 has one side surface 51g in contact with and pressed against the flat portion 52g by the restoring force of the flexible portion 51c.

[0129] In this manner, when positioning the second portion 51b of the optical fiber bundle 51 into the second groove 52b of the light guide holder 52, the tip of the second portion 51b of the optical fiber bundle 51 is positioned to protrude outward from the plane 52m of the peripheral edge of the second opening 52f of the second groove 52b. In this case, the amount A of the protrusion of the tip of the second portion 51b is, for example, about 0.1 to 0.2 mm.

[0130] Next, as shown by the reference numeral [14B] in Figure 14, a heat treatment process is performed on the end face of the tip (protruding portion) of the second portion 51b of the optical fiber bundle 51 by pressing a heated mirror plate (hot plate 70) against it. Here, the hot plate 70 is made of a metal substrate or a glass substrate, or the like.

[0131] By performing this processing using the hot plate 70, the protruding tip of the second portion 51b of the optical fiber bundle 51 becomes substantially flush with the plane 52m of the peripheral edge of the second opening 52f of the light guide holder 52, as shown by the reference numeral [14C] in Figure 14. In this case, when the amount of protrusion A of the optical fiber bundle 51 becomes less than 0.1 mm, it is considered to be substantially flush.

[0132] The flat surface at the tip of the optical fiber bundle 51 formed in this way becomes the light-emitting end face 51m of the optical fiber bundle 51.

[0133] As described above, by performing end-face heat treatment, the height of the exit end face 51m of the optical fiber bundle 51 relative to the plane of the light guide holder 52 is stabilized. This stabilizes the optical performance (light intensity and light distribution characteristics, etc.) of the lighting unit 50 using the optical fiber bundle 51. Furthermore, since the exit end face 51m of the optical fiber bundle 51 is smoothed by this end-face heat treatment, it can contribute to further improvement in light intensity.

[0134] The illumination lens 53 is positioned and mounted to cover the second opening 52f of the light guide holder 52. To this end, the illumination lens 53 has a positioning projection 53a, which is pin-shaped and protrudes downward, as shown in Figures 6 and 10. Correspondingly, a positioning recess 52d is formed in the light guide holder 52.

[0135] The illumination lens 53 is positioned by the positioning projection 53a fitting into the positioning recess 52d, thereby positioning it relative to the light guide holder 52.

[0136] Thus, the relative position and angle between the optical fiber bundle 51 and the illumination lens 53 are determined by mounting the optical fiber bundle 51 and the illumination lens 53 on the light guide holder 52. Therefore, with this configuration, the positioning of the optical fiber bundle 51 and the illumination lens 53 can be completed simply by performing the manufacturing and assembly work, and the adjustment process for positioning can be omitted. Therefore, it can contribute to reducing the manufacturing process and manufacturing costs.

[0137] Next, the general outline of the manufacturing method for the tip portion 5 of the endoscope 1 in this embodiment will be briefly described below.

[0138] First, an imaging unit 40 is positioned at a predetermined location inside the tip 5 of the insertion section 2 of the endoscope 1, so as to enable imaging in a second direction that intersects the first direction (longitudinal axis AX direction), which is the longitudinal direction of the insertion section 2.

[0139] Next, the optical fiber bundle 51 is positioned at a predetermined location inside the light guide holder 52. Here, the predetermined location inside the holder is the region including the first groove 52a, the second groove 52b, and the third groove 52c. The optical fiber bundle 51 is positioned so as to connect each of the grooves (52a, 52b, 52c) of the light guide holder 52.

[0140] Furthermore, at this time, the flexible portion 51c of the optical fiber bundle 51, which is positioned in the third groove 52c, is kept in contact with the gas, and the second portion 51b is bonded and fixed to the second groove 52b using adhesive 60.

[0141] Finally, the light guide holder 52 is positioned adjacent to the imaging unit 40 at the tip 5. In this way, the tip 5 of the endoscope 1 of this embodiment is assembled.

[0142] As described above, according to the above embodiment, in a single-use side-view endoscope, in a configuration in which a plastic optical fiber is applied to the optical fiber bundle 51 included in the illumination unit 50, a part of the optical fiber bundle 51 is configured as a bendable flexible portion 51c, and this flexible portion 51c is arranged inside the tip portion 5 in a state where it is curved toward a second direction intersecting the first direction (longitudinal axis AX).

[0143] In this configuration, the tip portion 5 has a third groove 52c in which the flexible portion 51c of the optical fiber bundle 51 is placed, and the third groove 52c is filled with gas, and the outer surface of the flexible portion 51c is kept in contact with the gas.

[0144] Furthermore, in the second groove 52b where the second portion 51b of the optical fiber bundle 51 is positioned, the restoring force of the flexible portion 51c causes one side surface 51g of the tip region of the second portion 51b to abut and press against the flat surface 52g of the inner surface of the tip region of the second groove 52b. In this state, the second portion 51b is bonded and fixed to the second groove 52b using adhesive 60.

[0145] This configuration makes it possible to suppress variations in the arrangement of the tip faces of the multiple optical fibers constituting the optical fiber bundle 51 and in the direction of emission of illumination light. At the same time, it is possible to suppress light leakage that may occur in the flexible portion 51c. Therefore, in the tip portion 5 of the endoscope 1 of this embodiment, light intensity loss or reduction in light intensity can be suppressed.

[0146] Therefore, the tip portion 5 of the endoscope 1 in this embodiment can be equipped with an illumination unit 50 that can ensure good optical performance, and thus, optimal light distribution characteristics can be obtained that can maintain a light intensity suitable for observation and uniformly illuminate an illumination range suitable for observation.

[0147] In general, it is known that the illumination range of the illumination unit 50 used in the endoscope 1 changes significantly depending on the positional relationship between the center of the exit end face of the optical fiber bundle 51 and the center of the illumination lens 53. Therefore, the positioning of the exit end face of the optical fiber bundle 51 relative to the illumination lens 53 must be performed with high precision.

[0148] In addition, in side-view endoscopes, the optical fiber bundle 51 is generally positioned at an angle of approximately 0 to 15 degrees toward the proximal end with respect to the central axis of the illumination lens 53 (see θ2 in Figure 10). In this case, if the angle of inclination (referred to as the attitude angle of the optical fiber bundle 51) deviates from the desired set angle, illumination light directed towards the desired irradiation range cannot be obtained, and the amount of illumination light becomes uneven. Therefore, setting the attitude angle of the optical fiber bundle 51 with high precision is important in order to obtain the desired optimal light distribution characteristics.

[0149] Even under these circumstances, there is always a demand for cost reduction in single-use endoscopes. Therefore, the lighting unit 50 applied to them requires high assembly efficiency, allowing for quick and easy assembly.

[0150] Therefore, in the endoscope of this embodiment, which is a single-use side-view endoscope, in a configuration in which a plastic optical fiber is applied to the optical fiber bundle 51 included in the illumination unit 50, the optical fiber bundle 51 is configured in a state in which the bent state of the flexible portion 51c is maintained.

[0151] This configuration makes it possible to suppress variations in the position of each exit end face of the multiple optical fiber strands constituting the optical fiber bundle 51 and the angle of the exit direction, thereby ensuring good optical performance (light quantity and light distribution characteristics suitable for observation).

[0152] [Disclosure of Invention 1] However, if damage occurs to the surface of an optical fiber strand, its mechanical properties and transmission performance may deteriorate. Furthermore, when forming an optical fiber bundle by bundling multiple optical fiber strands together, it is necessary to maintain the bundled state of each optical fiber strand.

[0153] Therefore, taking these factors into consideration, in conventional, for example, reusable endoscopes, a configuration has been put into practical use in which the optical fiber strands or optical fiber bundles (hereinafter abbreviated as optical fiber bundles, etc.) used in the illumination unit are protected on the outside by being inserted into a tubular protective member. In this case, the protective tube used is generally a silicone rubber protective tube that uses a friction reducer such as a solid lubricant.

[0154] However, considering factors such as the assembly process in a cleanroom for endoscopes and the need for cost reduction, there is a desire to avoid using anti-friction agents as much as possible. In particular, there is always a strong demand for cost reduction in single-use endoscopes, which have been rapidly gaining popularity in recent years. Therefore, adopting the same configuration as reusable endoscopes in single-use endoscopes would make cost reduction difficult and cannot be easily implemented.

[0155] Furthermore, in the case of single-use endoscopes, it may not be necessary to ensure watertightness or airtightness of the control section. In such cases, a configuration is required that allows for ethylene oxide gas sterilization (EOG sterilization) of the internal components of the control section.

[0156] However, in conventional configurations, for example, with silicone rubber protective tubes used for optical fiber bundles, there is a problem in that EOG sterilization cannot be performed in a short time because it takes time for the sterilization gas to penetrate into the tube. In addition, during gas sterilization, the silicone rubber tube expands due to the effect of negative pressure, and depending on the grade of the silicone rubber tube, it may deteriorate.

[0157] Therefore, in order to improve the sterilization of optical fiber bundles and other components in single-use endoscopes, a protective tube made of a material with superior sterilization properties is required, for example, to replace conventional silicone tubes.

[0158] Taking these factors into consideration, the following configuration example discloses a protective tube, such as an optical fiber bundle, that is particularly suitable for single-use endoscopes and offers better sterilization.

[0159] In this configuration example, a mesh tube, which is a cylindrical tube made by weaving together resin fibers, is used as a protective tube to cover the outer surface of an optical fiber bundle, which is made by bundling together multiple plastic optical fiber strands.

[0160] This protective tube corresponds to the outer sheath of the light guide cable 19 (see Figure 2). In other words, this protective tube is positioned on the outer surface of the light guide cable 19, which extends from the connector 13 connected to the light source device (not shown) as an external device, or from the light source device (not shown) inside the operating unit 3, and is routed to near the base end of the light guide holder 52 of the lighting unit 50.

[0161] In this manner, the protective tube is positioned on the outer surface of the optical fiber bundle 51. In other words, the optical fiber bundle 51 is inserted and positioned inside the protective tube. With this configuration, the protective tube covers the outer surface of the optical fiber bundle 51. In this state, the ends of the protective tube are reduced in diameter and fixed with adhesive.

[0162] To this end, the end of the protective tube is first positioned in a designated location on a special jig (not shown). At this point, adhesive is applied to the end of the protective tube.

[0163] Next, a special jig is pressed against the end of the protective tube to reduce its diameter. The adhesive is then allowed to harden in this state. After that, the special jig is released. As a result, the end of the protective tube is bonded and fixed in a reduced diameter state at a predetermined location on the optical fiber bundle 51.

[0164] For the mesh tube used as a protective tube, for example, polyamide fiber, polyester fiber, or acrylic fiber can be used. This ensures good sliding properties and flexibility.

[0165] Furthermore, the outer diameter of the fibers constituting the protective tube (mesh tube) affects its flexibility (the thicker the fibers, the lower the flexibility). Therefore, considering the flexibility of the protective tube, it is preferable to use fibers with an outer diameter of 25% or less of the outer diameter of the optical fiber strand.

[0166] Furthermore, the length of the protective tube (mesh tube) is approximately 3.1m when used in an endoscope. Considering the length of the protective tube, it is preferable to have a thermal shrinkage rate of 15% or less. If the thermal shrinkage rate exceeds 15%, stress is more likely to occur in the optical fiber bundle placed inside.

[0167] Furthermore, the inner diameter D1 of the protective tube (mesh tube) is preferably set to 1.2 times or more D2, where D2 is the bundle diameter of the optical fiber bundle when multiple optical fiber strands are closely packed in two dimensions to prevent movement of the optical fiber bundle inserted into the protective tube, and d2 is the outer diameter of the optical fiber strands. This ensures good ease of inserting the optical fiber bundle into the protective tube.

[0168] Specifically, for example, when inserting a bundle of optical fibers with a total length of 3.3 m and an outer diameter d2 = Φ0.5 mm, consisting of four bundled plastic optical fiber strands with a bundle diameter D2 = Φ1.21 mm, into a protective tube with a total length of 3.1 m, an inner diameter D1 = Φ1.8 mm, and a wall thickness of 0.3 mm, it can be inserted without any particular problems.

[0169] On the other hand, for example, when inserting a bundle of optical fibers with a total length of 3.3 m, an inner diameter D1 = Φ1.4 mm, and a wall thickness of 0.3 mm into a protective tube, the insertion resistance becomes too great midway through, making insertion impossible.

[0170] Furthermore, it is preferable that the protective tube (mesh tube) has a wall thickness of 0.8 mm or less. If it exceeds 0.8 mm, for example, the required flexibility cannot be obtained. It is even more preferable that the wall thickness be around 0.3 mm.

[0171] Furthermore, it is preferable that the protective tube (mesh tube) is set so that its bending force (flexibility) is 30 gf・cm² or less ([^] represents exponentiation). It is even more preferable that the bending force (flexibility) be around 13 to 23 gf・cm².

[0172] Furthermore, it is preferable that the protective tube (mesh tube) be set to have a braiding ratio of 50% or more. Sterilization is also ensured even with a braiding ratio of 100%. On the other hand, if the braiding ratio falls below 50%, it will be difficult to insert the optical fiber bundle through the protective tube, and good workability cannot be ensured. Specifically, for example, problems may occur such as the optical fiber protruding from the protective tube during the insertion of the optical fiber bundle.

[0173] Furthermore, it is preferable that the length of the reduced diameter portion at the end of the protective tube (mesh tube) be 1 mm or more. With this configuration, even if a load is applied to the light guide cable 19 when it is mounted on the endoscope or used, displacement of the protective tube can be suppressed, and interference with other components can be prevented.

[0174] Furthermore, it is preferable that the outer diameter of the end of the protective tube (mesh tube) is reduced by 15% or more compared to the outer diameter of the protective tube. More preferably, the reduction ratio of the outer diameter of the end is 17% to 30%.

[0175] Furthermore, it is preferable that the inner diameter of the end of the protective tube (mesh tube) is reduced by 10% or more compared to the inner diameter of the protective tube. It is even more preferable that the reduction in the inner diameter of the end be between 15% and 23%.

[0176] Furthermore, adhesive is used to secure the ends of the protective tube (mesh tube) to the optical fiber strands or bundle of optical fibers. Using adhesive as a means of joining the materials together allows for space savings.

[0177] In this case, it is preferable to use an adhesive with a glass transition temperature of 100 degrees Celsius or higher to fix the end of the protective tube (mesh tube) to the optical fiber strand or optical fiber bundle. This setting ensures sufficient adhesive strength against changes in ambient temperature.

[0178] Furthermore, it is preferable to use an epoxy adhesive or an acrylic adhesive to fix the ends of the protective tube (mesh tube) to the optical fibers or optical fiber bundle. This is because these types of adhesives have good adhesion to the protective tube material (braided material). Epoxy adhesives are more preferable as the adhesive.

[0179] With this type of protective tube, the assembly process does not require the use of anti-friction agents, and the tube has properties (for example, flexibility, sliding properties, bending properties, stretchability, adhesive properties, etc.) that allow for easy insertion of optical fiber bundles and the like into the protective tube.

[0180] Furthermore, the protective tube is made of a mesh tube. This configuration allows sterilization gas to easily penetrate and pass through the mesh tube during EOG sterilization. Therefore, the optical fiber bundle 51 can be sterilized effectively and reliably, ensuring good sterilization performance.

[0181] At the same time, because the protective tube is a mesh tube, it can suppress the expansion and rupture of the tube.

[0182] Furthermore, since the ends of the mesh tube are reduced in diameter and fixed with adhesive, even if a load is applied to the light guide cable 19 during installation on the endoscope or during use, displacement of the mesh tube can be suppressed, and interference with other components can be prevented.

[0183] Furthermore, it is possible to ensure advantageous characteristics that allow for the efficient arrangement of internal components within the internal space of the tip portion 5.

[0184] [Disclosure of the Invention 2] As described above, the endoscope 1 of the above embodiment is connected to the processor through a connector 13 provided at the extended end of the universal cable 4. The configuration of this connection part will be explained in more detail as shown in Figure 15.

[0185] Figure 15 is a conceptual diagram showing the configuration of the connection between the endoscope and the processor in this embodiment. Figures 16 and 17 are conceptual diagrams showing the connection state between the optical fiber bundle on the connector side and the optical fiber bundle on the adapter side in Figure 15. Of these, Figure 16 shows the state in which the connector and the adapter are disconnected. Figure 17 shows the state in which the connector and the adapter are connected.

[0186] As shown in Figure 15, the front panel of the processor 80 has an opening which is a connector receptacle 81 (on the processor side). Inside the connector receptacle 81, there is a light guide receptacle 81b and electrical contacts 81c (on the processor side), etc.

[0187] Furthermore, a light emission section (not shown) is provided at the rear of the light guide receiving section 81b for emitting illumination light from the light source device. The processor-side electrical contact 81c is a metal contact provided for electrically connecting the processor 80 and the endoscope 1.

[0188] The connector 13 is connected to this connector socket 81 through the adapter 82. That is, the adapter 82 is first fitted and connected to the connector socket 81.

[0189] The adapter 82 has an opening at its base that serves as a connector receiving opening 82a. The adapter 82 has a first light guide base 82b and an electrical contact 82c (on the adapter side) at its tip.

[0190] As shown in Figures 16 and 17, the first light guide socket 82b has a cylindrical socket member 82t and a rod lens 82r. The rod lens 82r is a columnar optical member and light guide member for uniformly transmitting illumination light from the light source device. The rod lens 82r is provided inside the cylindrical socket member 82t.

[0191] Here, the first light guide socket 82b is positioned opposite the light guide receiver 81b when the adapter 82 is fitted into the connector socket 81. Also, when the adapter 82 is fitted into the connector socket 81, the electrical contact 82c makes contact with the electrical contact 81c on the processor side, ensuring an electrical connection.

[0192] Furthermore, the adapter 82 has a first optical fiber bundle 83 arranged in a predetermined position inside. The first optical fiber bundle 83 is formed by bundling together multiple glass optical fiber strands.

[0193] The tip of the first optical fiber bundle 83 is connected to the base end face of the rod lens 82r inside the first light guide socket 82b (see reference numeral [C1] in Figures 16 and 17). The base end of the first optical fiber bundle 83 is positioned so that its end face is exposed to the connector receiving opening 82a (see reference numeral [C2] in Figures 16 and 17).

[0194] As described above, the connector 13 is provided at the extended end of the universal cable 4 and is a connecting member for connecting the endoscope 1 to the processor 80. In this case, in the example configuration illustrated in this embodiment, the connector 13 is connected to the processor 80 via an adapter 82.

[0195] The tip of the connector 13 has a second light guide socket 13a and a mating projection 13b. As shown in Figures 16 and 17, an optical fiber bundle 51 is arranged inside the second light guide socket 13a. In this case, the tip surface of the second light guide socket 13a and the tip surface of the optical fiber bundle 51 are formed on substantially the same plane.

[0196] The mating projection 13b is the part that fits into the connector receiving opening 82a of the adapter 82. The mating projection 13b is formed to be hollow. Inside the mating projection 13b, a second light guide base 13a, an air supply / water supply conduit (not shown), and electrical contacts (not shown) are arranged.

[0197] The tip of the second light guide socket 13a is positioned opposite the base end of the first optical fiber bundle 83 when the connector 13 is fitted into the connector opening 82a (see reference numeral [C2] in Figure 17). At this time, the tip surface of the second light guide socket 13a and the base end surface of the first optical fiber bundle 83 are positioned in near-contact with a small gap (approximately 0.1 mm) in between.

[0198] The light guide cable 19 has an optical fiber bundle 51 inserted and arranged inside. The optical fiber bundle 51 is formed by bundling together multiple strands of plastic optical fiber.

[0199] When connecting the connector 13 to the adapter 82 configured in this way, the mating projection 13b of the connector 13 is fitted toward the connector receiving opening 82a of the adapter 82 (see the direction of arrow P in Figures 16 and 17).

[0200] As a result, the first optical fiber bundle 83 is connected to the optical fiber bundle 51. Then, by fitting the adapter 82 into the connector socket 81 of the processor 80, a light guide path is formed from the light guide cable 19 (optical fiber bundle 51) through the first optical fiber bundle 83 and the first light guide socket 82b to the processor 80.

[0201] The present invention is not limited to the embodiments described above, and various modifications and applications can be implemented without departing from the spirit of the invention. Furthermore, the above embodiments include inventions at various stages, and various inventions can be extracted by appropriate combinations of the multiple components disclosed. For example, if the problem that the invention aims to solve can be solved and the effects of the invention can be obtained even if some components are deleted from all the components shown in one embodiment, then the configuration with these components deleted can be extracted as an invention. Furthermore, components from different embodiments may be combined as appropriate. This invention is not limited by any particular embodiment other than being limited by the appended claims.

[0202] 1...Endoscope 2...Insertion section 3...Operation section 4...Universal cable 5...Tip section 6...Bending section 7...Flexible tube section 8...Grip section 9...Instrument insertion port 10...Bending operation knob 11...Operation button 12...Instrument lifting lever 13...Connector 13a...Second light guide socket 13b...Matching projection 14...Instrument insertion tube 15...Fluid tube 15a...Connecting pipe 16...Lifting sheath 17...Lifting wire 18...Imaging cable 19...Light guide cable 20...Tip component 21...Conduit 23...Regulating member 26...Storage chamber 27...Imaging aperture 28...Illumination aperture 30...Lifting platform 40...Imaging unit 41...Imaging lens 42...Image sensor 43...Observation window 50...Illumination unit 51...Optical fiber bundle 51a...First section 51b...Second section 51c...Flexible part 51g...One side 51h...Side part 51m...Ejection end face 52...Light guide holder (holder) 52a...First groove 52b...Second groove 52c...Third groove 52g...Flat part 52j...Convex part 52h...Other flat part 52k...Side opening 52m...Flat part 53...Illumination lens 60...Adhesive 61...Light guide cover 62...Tip cover 70...Hot plate 80...Processor 81...Connector receptacle 81b...Light guide receptacle 81c...Electrical contact 82...Adapter 82a...Connector receptacle opening 82c...Electrical contact 100...Pressing jig 100a...Convex shape

Claims

1. The tip of an endoscope comprising: an imaging unit that images a second direction intersecting a first direction which is the longitudinal direction of the insertion portion of the endoscope; a holder provided adjacent to the imaging unit and having a first groove formed along the first direction, a second groove provided along the second direction and formed distal to the first groove, and a third groove whose proximal end is connected to the first groove and distal end is connected to the second groove; a plurality of optical fibers having, in order from the proximal end, a first portion, a bendable flexible portion, and a second portion, wherein the first portion is positioned in the first groove, the second portion is fixed in the second groove with adhesive, and the flexible portion is positioned in the third groove; and a gas that fills the third groove and comes into contact with the plurality of optical fibers.

2. The tip portion of the endoscope according to claim 1, characterized in that the first portion is fixed in the first groove with the adhesive.

3. The tip portion of the endoscope according to claim 1, characterized in that the adhesive is an ultraviolet-curing adhesive.

4. The tip portion of the endoscope according to claim 1, characterized in that the adhesive is a thermosetting adhesive.

5. The tip portion of the endoscope according to claim 1, characterized in that the second groove has a flat portion on the inner surface of the tip region into which one side surface of the second portion of the plurality of optical fibers abuts due to the restoring force of the flexible portion.

6. The tip portion of the endoscope according to claim 1, characterized in that at least two of the optical fibers have sides in contact with the flat portion.

7. The tip of the endoscope according to claim 1, characterized in that it has four optical fibers, and the sides of two of the four optical fibers are in contact with the flat surface.

8. The tip of the endoscope according to claim 1, characterized in that the plurality of optical fibers are made of plastic.

9. The tip of the endoscope according to claim 1, characterized in that the plurality of optical fibers have an outer diameter of 0.2 mm to 0.8 mm.

10. The tip of the endoscope according to claim 1, characterized in that the cross-sectional shape of the second groove is substantially rectangular.

11. The tip of the endoscope according to claim 1, characterized in that the area to which a portion of the adhesive adheres to the flexible portion is within 30% of the flexible portion.

12. An endoscope characterized by comprising the tip portion of an endoscope as described in claim 1.

13. A method for manufacturing the tip of an endoscope, characterized by arranging an imaging unit to image in a second direction intersecting a first direction which is the longitudinal direction of the insertion portion of the endoscope; arranging a plurality of optical fibers in a holder having a first groove provided along the first direction, a second groove provided along the second direction and provided distal to the first groove, and a third groove whose proximal side is connected to the first groove and whose distal side is connected to the second groove; maintaining a state in which the flexible portion of the plurality of optical fibers arranged in the third groove is in contact with a gas; bonding and fixing the plurality of optical fibers to the second groove with an adhesive; and arranging the holder adjacent to the imaging unit.

14. The method for manufacturing the tip of an endoscope according to claim 13, characterized in that the ends of the plurality of optical fibers are pressed against a hot plate to form a flat surface.

15. The tip of an endoscope comprising: an optical fiber bundle having a first row in which at least two optical fibers are arranged side by side, and a second row having at least one optical fiber arranged adjacent to the first row; a holder having a first groove provided along a first direction, a second groove provided along a direction intersecting the first direction and provided distal to the first groove, and a third groove whose proximal side is connected to the first groove and whose distal side is connected to the second groove, wherein the optical fiber bundle is arranged in the first groove, the second groove, and the third groove; a flat portion formed in the second groove, to which the side surfaces of the tips of at least two optical fibers of the first row abut; an adhesive provided in the second groove proximal to the flat portion along the longitudinal axis of the optical fiber bundle, for fixing the optical fiber bundle to the holder; and a bending portion which is a part of the optical fiber bundle and is arranged in the third groove, wherein the restoring force generated by bending the optical fiber bundle presses the side surfaces of the tips of at least two optical fibers of the first row against the flat portion.

16. The tip of the endoscope according to claim 15, characterized in that the number of optical fibers in the first row is the same as the number of optical fibers in the second row.

17. The tip of the endoscope according to claim 16, characterized in that the number of optical fibers in the first row and the number of optical fibers in the second row are two.

18. The tip of the endoscope according to claim 15, characterized in that the first and second rows of optical fibers are made of plastic.

19. The tip of the endoscope according to claim 18, characterized in that the first and second rows of optical fibers have an outer diameter of 0.2 mm to 0.8 mm.

20. The tip portion of the endoscope according to claim 15, characterized in that the adhesive is an ultraviolet-curing adhesive.

21. The tip portion of the endoscope according to claim 15, characterized in that the adhesive is a thermosetting adhesive.

22. The tip of the endoscope according to claim 15, characterized in that the first direction and the second direction intersect at an angle of 60 to 100 degrees.

Images