JP6055691B2 - Endoscope - Google Patents

Description

  The present invention relates to an endoscope, and more particularly to a small-diameter endoscope specialized for observation that does not have channels as used as a nasopharyngeal scope.

  This type of small-diameter endoscope has, as its basic configuration, a cylindrical observation optical unit that faces the distal end of the insertion portion, and an illumination light that is located on the outer periphery of the cylindrical observation optical unit and that exits from the emission end surface of the distal end. And a light guide fiber that emits light. The conventional product has a problem that the light guide fiber exit end face is exposed at the tip of the insertion section, which may cause damage to the light guide fiber exit end face, and a desired light distribution characteristic cannot be obtained. It was.

  In order to solve this problem, in Patent Document 1, a distal end cover made of a transparent resin having an annular shape portion covering the emission end face of the light guide fiber is provided at the distal end portion of the insertion portion. However, in order to fix the distal end cover to the distal end portion of the insertion portion, a peripheral body portion extending from the outer peripheral edge of the annular portion in the longitudinal direction of the insertion portion is provided, and this peripheral body portion is arranged along the outer peripheral side of the light guide fiber. Therefore, the diameter of the insertion portion is increased. In addition, the illumination light emitted from the exit end face of the light guide fiber is blocked by the outer peripheral surface (non-translucent insulating member) of the cylindrical observation optical unit, so that the amount of illumination light is reduced and the light distribution range is also narrowed. End up.

  In Patent Document 2, the distal end rigid portion is made of a transparent member that can transmit illumination light, and a fiber insertion hole is provided in the distal end rigid portion for inserting and holding the light guide fiber. At the tip of the fiber insertion hole, there is a concave surface (lens surface) for diffusing / condensing illumination light emitted from the emission end face of the light guide fiber, and the periphery of the emission end face of the light guide fiber arranged so as to surround the concave face. A contact surface to which the part is applied is formed. However, since it is essential to form the abutting part at the tip of the fiber insertion hole, the design of the concave surface (lens surface) is limited, and the light guide fiber exit end face applied to the abutting part Since the illumination light emitted from the peripheral edge of the lens does not pass through the concave surface (lens surface), a sufficient diffusion / condensing effect cannot be obtained.

Japanese Patent No. 4704386 JP 2009-207529 A

  The present invention has been completed based on the above awareness of the problem, and prevents damage to the exit end face of the light guide fiber, reduces the diameter of the insertion portion, and the amount of illumination light from the light guide fiber. An object of the present invention is to obtain an endoscope capable of realizing a desired light distribution characteristic by securing a light distribution range and sufficiently diffusing / condensing the light.

  The endoscope of the present invention is a cylindrical observation optical unit facing the distal end portion of the insertion portion of the endoscope, and is located in the outer periphery of the cylindrical observation optical unit, and emits illumination light from the emission end face of the distal end. In an endoscope provided with a light guide fiber, a fiber holding cylinder that is positioned outside the cylindrical observation optical unit and holds the light guide fiber with its exit end face exposed, and A flange-shaped covering portion that is located at the distal end and covers the emission end face of the light guide fiber held by the fiber holding tube, and a cylindrical fitting that protrudes in the longitudinal direction of the insertion portion from the inner peripheral edge of the flange-shaped covering portion And a cover member that distributes illumination light emitted from the emission end face of the light guide fiber to the field of view of the cylindrical observation optical unit, and an outer periphery of the distal end of the cylindrical observation optical unit A cylindrical fitting space is formed between the inner periphery of the tip end portion of the fiber holding cylinder, and the cylindrical fitting portion of the cover member is fitted into the cylindrical fitting space. It is said.

  It is preferable that the light guide fiber is provided with a pair facing each other with the cylindrical observation optical unit sandwiched from the radial direction.

  The fiber holding cylinder has an outer cylinder that is long in the longitudinal direction, and an inner support ring that is shorter in the longitudinal direction than the outer cylinder and fits inside the tip of the outer cylinder, and the outer cylinder and the inner support ring It is preferable that a pair of fiber insertion holes for inserting the pair of light guide fibers is formed between them.

  It is preferable that the flange-shaped covering portion of the cover member is provided with a lens surface, a diffusion surface, or a diffusion plate for diffusing / condensing illumination light emitted from the emission end surfaces of the pair of light guide fibers.

  The lens surface, the diffusing surface, or the diffusing plate is provided with a pair corresponding to the emission end surfaces of the pair of light guide fibers, and the pair of lens surfaces, diffusing between the fiber holding cylinder and the cover member. It is preferable that a positioning unit is provided to make the phases in the circumferential direction of the surface or the diffusing plate and the emission end faces of the pair of light guide fibers coincide with each other so as to face each other.

  The pair of lens surfaces can have a concave surface or a convex surface directed toward the emission end surfaces of the pair of light guide fibers.

  The outer peripheral surface of the flange-shaped covering portion of the cover member may be a straight shape having substantially the same diameter in the longitudinal direction, or a tapered shape that is reduced in diameter toward the distal end side of the insertion portion.

  According to the present invention, the emission end face of the light guide fiber is prevented from being damaged, the diameter of the insertion portion is reduced, and the amount of illumination light from the light guide fiber and the light distribution range are secured to sufficiently diffuse / collect the light. An endoscope capable of realizing a desired light distribution characteristic by causing light to be emitted can be obtained.

It is a sectional side view which shows the front-end | tip part of the insertion part of the endoscope by this invention. It is sectional drawing which follows the II-II line of FIG. It is a perspective view which shows the state before fitting a cover member in the front-end | tip part of an insertion part. It is a sectional side view corresponding to FIG. 1 which shows the effect of the endoscope by this invention. FIG. 6 is a side sectional view corresponding to FIG. 1 showing another embodiment of the endoscope according to the present invention. It is a figure which shows another embodiment of the endoscope by this invention. FIG. 7A is a view showing still another embodiment of the endoscope according to the present invention, and FIG. 7A is a view showing an embodiment in which a pair of convex lens surfaces are provided on the flange-shaped covering portion of the cover member, and FIG. B) is a view showing an embodiment in which a pair of diffusion plates is provided on the flange-shaped covering portion of the cover member. It is a figure which shows another embodiment of the endoscope by this invention, and FIG. 8 (A) is sectional drawing corresponding to FIG. 2 which shows the engagement recessed part of a fiber holding cylinder, and the engagement convex part of a cover member. FIG. 8 (B) is a front view of the single structure of the cover member as seen from the rear.

  Hereinafter, an embodiment of an endoscope (electronic endoscope) 10 according to the present invention will be described with reference to FIGS. 1 to 4. The endoscope 10 of the present embodiment is a small-diameter endoscope specialized for observation that does not have channels that are used as, for example, a nasopharyngeal scope.

  The endoscope 10 has a long insertion portion 11 having flexibility. The outer surface of the insertion portion 11 is covered with an insulating outer skin portion 12. In the front-rear direction in this specification, the distal end side of the insertion portion 11 is “front”, and the proximal end side of the insertion portion 11 is “rear”.

  Inside the insertion portion 11, a cylindrical observation optical unit 20 facing the distal end portion of the insertion portion 11 is provided. The cylindrical observation optical unit 20 is configured by holding an objective lens group 22 on a cylindrical member 21 made of a non-translucent insulating material. An image sensor 23 and a drive circuit 24 are sequentially positioned behind the cylindrical observation optical unit 20, and a signal cable 25 including a plurality of signal lines is connected to the image sensor 23 and the drive circuit 24. The image sensor 23, the drive circuit 24, and the signal cable 25 are configured to have a front end portion as a package portion molded with an adhesive, and the outside of the package portion is covered with a shield ring 26. A subject image is formed on the imaging surface of the image sensor 23 by the cylindrical observation optical unit 20 (objective lens group 22), and an image signal obtained by photoelectric conversion is sent to an image processing device (not shown) via the signal cable 25. The subject image is displayed or recorded. O in FIG. 1 is the optical axis of the cylindrical observation optical unit 20 (objective lens group 22). The image pickup surface of the image pickup device 23 has a horizontally long rectangle, the arrow L in FIGS. 1 and 3 is the long side direction of the image pickup surface of the image pickup device 23, and the arrow S in FIG. The side direction.

  A pair of light guide fibers 30 formed by bundling a plurality of optical fibers is provided inside the insertion portion 11 so as to be positioned outside the cylindrical observation optical unit 20. The pair of light guide fibers 30 guides illumination light from a light source device (not shown) and emits the light from the emission end face 31 at the tip. As shown in FIGS. 1 and 3, the pair of light guide fibers 30 are spaced apart in the direction of the long side L of the image pickup surface of the image pickup device 23 and extend along the direction of the optical axis O. Cylindrical observation Opposing the optical unit 20 from the radial direction. In addition, the emission end faces 31 of the pair of light guide fibers 30 are elongated in the direction of the short side S of the imaging surface of the imaging element 23 to form a crescent shape, and have a symmetrical shape with the optical axis O as the center. . More specifically, the emission end faces 31 of the pair of light guide fibers 30 have a shape obtained by cutting an arc centered on the optical axis of the cylindrical observation optical unit 20 with a line segment parallel to the short side S in front view. doing. By arranging the pair of light guide fibers 30 in this manner, the display area of the horizontally long monitor having an aspect ratio of 5: 4, 4: 3, 16: 9, for example, is fully used, and the layout of the insertion portion 11 is wasted. It is possible to reduce the diameter and reduce the loss of illumination light.

  A fiber holding cylinder 40 is provided inside the insertion portion 11 so as to be positioned outside the cylindrical observation optical unit 20. The fiber holding cylinder 40 holds a predetermined length near the tips of the pair of light guide fibers 30 with the emission end face 31 exposed. The fiber holding cylinder 40 includes an outer cylinder 41 that is long in the longitudinal direction, and an inner support ring 42 that is shorter in the longitudinal direction than the outer cylinder 41 and fits inside the distal end portion of the outer cylinder 41. A pair of fiber insertion holes 43 for inserting a pair of light guide fibers 30 is formed between the outer cylinder 41 and the inner support ring 42. The tip portions of the pair of light guide fibers 30 are inserted into the pair of fiber insertion holes 43 and fixed by bonding. A through hole 44 is formed in the inner support ring 42, and the cylindrical observation optical unit 20 (cylindrical member 21) is fixed in the fiber holding cylinder 40 in a state of protruding forward from the through hole 44.

  As shown in FIG. 1, a cylindrical fitting space is provided between the outer periphery of the distal end portion of the cylindrical observation optical unit 20 (cylindrical member 21) and the inner periphery of the distal end portion of the fiber holding tube 40 (inner support ring 42). 50 is formed.

  The distal end portion of the insertion portion 11 is a light-transmitting and insulating material that distributes illumination light emitted from the emission end faces 31 of the pair of light guide fibers 30 to the field of view of the cylindrical observation optical unit 20 (objective lens group 22). A cover member 60 is provided. The cover member 60 includes a flange-shaped covering portion 61 that covers the emission end face 31 of the pair of light guide fibers 30 held by the fiber holding tube 40, and the longitudinal direction of the insertion portion 11 from the inner peripheral edge of the flange-shaped covering portion 61. It has a rotationally symmetric shape having a protruding cylindrical fitting portion 62. The flange-shaped covering portion 61 is orthogonal to the longitudinal direction of the insertion portion 11, and the outer peripheral surface thereof forms a straight portion 61a having substantially the same diameter in the longitudinal direction. The cover member 60 fits the tubular fitting portion 62 into the tubular fitting space 50, and the rear end portion outer periphery of the flange-shaped covering portion 61, the distal end portion outer periphery of the fiber holding tube 40 (outer tube 41), and By applying the adhesive b over the outer periphery of the distal end portion of the outer skin portion 12, it is fixed to the distal end portion of the insertion portion 11.

  In the endoscope 10 configured as described above, as shown in FIG. 4, the flange-shaped covering portion 61 of the cover member 60 covers and protects the emission end faces 31 of the pair of light guide fibers 30. Further, it is possible to prevent the emission end face 31 of the pair of light guide fibers 30 from being damaged.

  Moreover, since the cover member 60 is made of an insulating material and the cylindrical fitting portion 62 is fitted in the cylindrical fitting space 50, the circumferential space inside the insertion portion 11 is effectively used. Therefore, it is not necessary to provide a component corresponding to the peripheral body portion of Patent Document 1 described above, and the diameter of the insertion portion 11 can be reduced. That is, the “length A” in FIG. 4 can be made as small as possible.

  In addition, since the cylindrical fitting portion 62 of the cover member 60 serves as an insulating ring, the number of parts can be reduced without providing an insulating ring as a separate member, and the flange-shaped covering portion 61 of the cover member 60 can be reduced. The illumination light can be emitted in a wide range from (a loss of illumination light can be reduced). That is, the “angle α” in FIG. 4 can be increased to the limit. If an insulating ring is provided as a separate member between the cylindrical observation optical unit 20 (cylindrical member 21) and the fiber holding cylinder 40 (inner support ring 42), the number of parts increases and a pair of light guides is provided. When the illumination light emitted from the emission end face 31 of the fiber 30 is blocked by the insulating ring, the amount of illumination light is reduced and the light distribution range is narrowed.

  FIG. 5 shows another embodiment of an endoscope 10 according to the present invention. In this embodiment, the outer peripheral surface of the flange-shaped covering portion 61 forms a tapered portion 61 b whose diameter decreases toward the distal end side of the insertion portion 11. As a result, the insertion portion 11 of the endoscope 10 can be easily inserted into the nostril or pharyngeal hole of the subject to reduce the burden on the subject, and the operator (doctor) has excellent workability. ing.

  FIG. 6 shows yet another embodiment of an endoscope 10 according to the present invention. In this embodiment, a pair of lens surfaces 63 for diffusing illumination light emitted from the emission end faces 31 of the pair of light guide fibers 30 is formed on the flange-shaped covering portion 61 of the cover member 60. The pair of lens surfaces 63 is a concave lens surface having a concave surface directed toward the emission end surface 31 of the pair of light guide fibers 30.

  According to this embodiment, since it is not necessary to provide a component corresponding to the contact surface of Patent Document 2 described above, the illumination light emitted from the entire area of the emission end face 31 of the pair of light guide fibers 30 is a concave lens without leakage. A sufficient diffusion effect can be obtained through the surface 63, and the degree of freedom in designing the concave lens surface 63 can be increased.

  FIGS. 7A and 7B show still another embodiment of the endoscope 10 according to the present invention. In the embodiment of FIG. 7A, the flange-shaped covering portion 61 of the cover member 60 has a convex surface directed toward the emission end face 31 of the pair of light guide fibers 30 instead of the pair of concave lens surfaces 63 of FIG. A pair of convex lens surfaces 64 are provided so that illumination light emitted from the emission end surface 31 is condensed. In the embodiment of FIG. 7B, a pair of fitting recesses 65 are formed in the flange-shaped covering portion 61 of the cover member 60 instead of the pair of concave lens surfaces 63 of FIG. A pair of diffusing plates 66 are fitted into each other. Whether the concave lens surface 63, the convex lens surface 64, or the diffusion plate 66 is provided on the flange-shaped covering portion 61 of the cover member 60 is determined according to the nature (requirement) of the endoscope 10.

  Although not shown, a pair of diffusion surfaces for diffusing illumination light emitted from the emission end faces 31 of the pair of light guide fibers 30 may be formed on the flange-shaped covering portion 61 of the cover member 60. Good.

  8A and 8B show still another embodiment of the endoscope 10 according to the present invention. In this embodiment, an arcuate engagement recess (positioning means) 45 is formed in a part of the inner support ring 42 of the fiber holding cylinder 40 in the circumferential direction, and the circumference of the cylindrical fitting portion 62 of the cover member 60 is formed. An arc-shaped engaging convex portion (positioning means) 67 is formed in a part of the direction. As a result, the relative rotation between the fiber holding cylinder 40 and the cover member 60 is restricted only by engaging the engagement convex portion 67 with the engagement concave portion 45, and a pair of flange portions 61 formed on the cover member 60 is formed. The concave lens surface 63, the convex lens surface 64, the fitting concave portion 65, the diffusion plate 66 or the diffusion surface, and the light emitting fiber end face 31 of the pair of light guide fibers 30 can be made to coincide with each other to face each other.

  In the above embodiment, the case where the endoscope 10 of the present invention is applied to a small-diameter endoscope specialized for observation that does not have channels that are used as a nasopharyngeal scope has been described as an example. However, the present invention can be similarly applied to an endoscope having various channels such as a treatment instrument insertion channel and an air / water supply channel.

  In the above embodiment, the case where the pair of front crescent-shaped light guide fibers 30 facing each other with the cylindrical observation optical unit 20 in the radial direction is described as an example, but the front of the pair of light guide fibers 30 is described. The shape is not limited to the crescent shape, and instead of arranging a pair, a front annular light guide fiber surrounding the cylindrical observation optical unit 20 can be used.

  In the above embodiment, the case where the pair of lens surfaces 63 and 64, the diffusion plate 66, or the diffusion surface (not shown) are provided corresponding to the emission end surfaces 31 of the pair of light guide fibers 30 has been described as an example. However, a mode in which the lens surface, the diffusion plate, or the diffusion surface is continuously formed in the circumferential direction is also possible.

DESCRIPTION OF SYMBOLS 10 Endoscope 11 Insertion part 12 Outer part 20 Cylindrical observation optical unit 21 Cylindrical member 22 Objective lens group 23 Imaging element 24 Drive circuit 25 Signal cable 26 Shield ring 30 Light guide fiber 31 Output end face 40 Fiber holding cylinder 41 Outer cylinder 42 Inner support ring 43 Fiber insertion hole 44 Through hole 45 Engaging recess (positioning means)
50 cylindrical fitting space 60 cover member 61 flange-shaped covering portion 61a straight portion 61b tapered shape portion 62 cylindrical fitting portion 63 concave lens surface 64 convex lens surface 65 fitting concave portion 66 diffuser plate 67 engaging convex portion (positioning means)

Claims (7)

An internal observation optical unit that faces the distal end of the insertion portion of the endoscope, and a light guide fiber that is positioned outside the cylindrical observation optical unit and emits illumination light from the exit end face of the distal end In the endoscope,
A fiber holding cylinder that is located in the outer periphery of the cylindrical observation optical unit and holds the light guide fiber in a state in which its emission end face is exposed; and
A flange-shaped covering portion that is positioned at the distal end portion of the insertion portion and covers the emission end face of the light guide fiber held by the fiber holding tube, and projects from the inner peripheral edge of the flange-shaped covering portion in the longitudinal direction of the insertion portion. And a cover member that distributes illumination light emitted from the emission end face of the light guide fiber to the field of view of the cylindrical observation optical unit,
A cylindrical fitting space is formed between the outer periphery of the distal end of the cylindrical observation optical unit and the inner periphery of the distal end of the fiber holding cylinder, and the cylindrical fitting space of the cover member is formed in the cylindrical fitting space. An endoscope characterized in that a joint is fitted. The endoscope according to claim 1, wherein
The said light guide fiber is an endoscope provided with a pair which opposes on both sides of the said cylindrical observation optical unit from radial direction. The endoscope according to claim 2, wherein
The fiber holding cylinder has an outer cylinder that is long in the longitudinal direction, and an inner support ring that is shorter in the longitudinal direction than the outer cylinder and fits inside the tip of the outer cylinder, and the outer cylinder and the inner support ring An endoscope in which a pair of fiber insertion holes for inserting the pair of light guide fibers is formed therebetween. The endoscope according to claim 2 or 3,
An endoscope in which the flange-shaped covering portion of the cover member is provided with a lens surface, a diffusion surface, or a diffusion plate for diffusing / condensing illumination light emitted from the emission end surfaces of the pair of light guide fibers. The endoscope according to claim 4, wherein
The lens surface, the diffusing surface or the diffusing plate is provided with a pair corresponding to the emission end surfaces of the pair of light guide fibers,
Positioning between the fiber holding cylinder and the cover member so that the phase in the circumferential direction of the pair of lens surfaces, the diffusing surface or the diffusing plate and the emitting end surface of the pair of light guide fibers is matched to face each other Endoscope provided with means. The endoscope according to claim 5, wherein
The pair of lens surfaces is an endoscope in which a concave surface or a convex surface is directed toward an emission end surface of the pair of light guide fibers. The endoscope according to any one of claims 1 to 6,
An endoscope in which an outer peripheral surface of the flange-shaped covering portion of the cover member has a straight shape with substantially the same diameter in the longitudinal direction or a tapered shape with a diameter decreasing toward the distal end side of the insertion portion.