WO2018198712A1

WO2018198712A1 - Distal end section for endoscope

Info

Publication number: WO2018198712A1
Application number: PCT/JP2018/014603
Authority: WO
Inventors: 健太郎河野
Original assignee: オリンパス株式会社
Priority date: 2017-04-25
Filing date: 2018-04-05
Publication date: 2018-11-01

Abstract

This distal end section for an endoscope comprises: an element frame 31; a lens frame 22; a case 40; a pair of crescent-shaped sections 51 provided between the pair of flat surface sections of the element frame 31 and a first range 40n1 of a first inner peripheral surface 40n of the case 40 and having a crescent-like cross-sectional shape; a light emission end section 52 provided continuously with the distal end side of the pair of crescent-shaped sections 51 and configured such that a second inner peripheral surface and a second outer peripheral surface are formed in similar circular arc shapes, the second inner peripheral surface being disposed outside the lens frame 22 in a radial direction R, the maximum outer diameter R7 of the light emission end section 52 being smaller than the maximum outer diameter R8 of the crescent-shaped sections 51; and a light guide fiber bundle for emitting illuminating light from the light emission end section 52.

Description

End of the endoscope

The present invention relates to a distal end portion of an endoscope including a light guide fiber bundle that irradiates illumination light from a light emitting end portion.

In recent years, endoscopes are widely used in the medical field. An endoscope used in the medical field can observe an organ in a body cavity by inserting an elongated insertion portion into a body cavity as a subject and using an objective lens unit and an imaging unit provided at a distal end portion of the insertion portion. it can.

In the objective lens unit, an optical system composed of an objective lens exposed at the distal end surface of the distal end portion of the insertion portion and one or a plurality of optical lenses positioned behind the objective lens is held in a lens frame. The main part is constituted by.

In addition, the imaging unit is held in the element frame, and an imaging element such as a CCD or CMOS that images the inside of the subject via the optical system, and is electrically connected to the imaging element and mounted with electronic components The main part is composed of a substrate and a cable that is electrically connected to the substrate and transmits and receives an electrical signal to the substrate.

Furthermore, in addition to the objective lens unit and the imaging unit described above, a light guide fiber bundle for supplying illumination light into the subject is inserted in the insertion portion, and the light emitting end portion of the light guide fiber bundle is a tip portion. It is being fixed so that it may be exposed to the front end surface.

By the way, in an endoscope used in, for example, otolaryngology, there is a demand for reducing the diameter of the insertion portion in order to reduce pain when the insertion portion is inserted into a subject.

Also, a configuration in which the outer diameter of the insertion portion is determined by the outer diameter of the element frame that holds the image sensor is well known. Therefore, a configuration in which the diameter of the insertion portion is reduced by downsizing the image sensor is well known, but downsizing of the image sensor has a technical limit.

Furthermore, endoscopes are required to have higher observation performance, and the image sensor has been further increased in the number of pixels. However, when the image sensor is reduced in size, the pixel pitch is reduced and the light receiving area of one pixel is reduced. There was a problem that would decrease.

Therefore, although the number of pixels of the image sensor is increasing, the sensitivity characteristics of the current image sensor that has been reduced in size are supplied from the light guide fiber bundle in the subject to compensate for the decrease in the amount of light received per unit image sensor. It is necessary to increase the amount of illumination light to be emitted.

However, in order to increase the amount of illumination light, it is necessary to increase the total area of the light guide fiber bundle inserted into the insertion portion, that is, it is necessary to increase the number of fibers. There was a problem of becoming.

In view of such a problem, Japanese Patent No. 5112575 discloses a cross section between a notch and a case covering the outer periphery of the element frame by notching a pair of opposing portions on the outer peripheral surface of the element frame. A configuration of an endoscope distal end portion is disclosed in which a crescent-shaped light guide fiber bundle is arranged so that the total area can be made larger than that of a light guide fiber having a circular cross section. Further, an endoscope capable of increasing the total area of the light guide fiber bundle without increasing the diameter of the insertion portion by arranging the light guide fiber bundle in the excess space in the case formed by the notch. The structure of the tip portion of is disclosed.

Here, at the distal end portion of the insertion portion of the endoscope, in order to improve the insertability of the distal end portion into the subject, a range closer to the distal end than the imaging unit, that is, a range where the objective lens unit is provided. There is a demand for smaller diameters.

However, in the configuration disclosed in Japanese Patent No. 5112575, the light guide fiber bundle is inserted to the tip surface while maintaining a crescent-shaped cross section.

For this reason, there is a problem in that the outer circumference of the range in which the objective lens unit to which the distal end hard member, the distal end of the case, the outer sheath distal end of the insertion portion, etc. are fixed is provided in addition to the lens frame. there were.

Such a problem can be solved by reducing the cross-sectional area of the light guide fiber bundle, that is, the number of fibers, but in this case, the amount of illumination light supplied into the subject is reduced.

The present invention has been made in view of the above problems, and an endoscope having a configuration capable of increasing the amount of illumination light supplied from the light guide fiber bundle into the subject while realizing a reduction in diameter. The object is to provide a tip.

The distal end portion of the endoscope according to one aspect of the present invention has a first outer peripheral surface formed by a pair of opposed arc portions and a pair of flat portions that are continuous with the arc portions and are opposed to each other. And a cylindrical member having an outer diameter smaller than the outer diameter of the pair of arc portions, and is provided on the distal end side of the first frame member and is incident on the imaging element A second frame member in which an optical member through which light passes is provided, the first frame member and the second frame member are provided therein, and at least the first frame on the first inner peripheral surface A third frame member formed as a cylindrical surface having a first diameter in which a first range in which the member is provided is larger than the arc portion; and the pair of plane portions and the first inner peripheral surface. A pair of cross sections formed between the first range and a crescent shape The second inner peripheral surface is formed in a similar circular arc with the second inner peripheral surface and the second outer peripheral surface being connected to the tip side of the sun-moon shaped portion and the pair of crescent-shaped portions. A light guide fiber that is disposed on the outer side in the radial direction of the second frame member and has a light emission end portion whose maximum outer diameter is smaller than that of the crescent moon shape portion, and irradiates illumination light from the light emission end portion And a bundle.

The fragmentary perspective view which shows the endoscope which comprises the front-end | tip part of the endoscope of this Embodiment in the front end side of an insertion part. The fragmentary sectional view of the front-end | tip part of the insertion part in the endoscope of FIG. Partial sectional view of the tip along the line III-III in FIG. Partial sectional view of the tip along the line IV-IV in FIG. The partial perspective view which expands and shows the objective lens unit of FIG. 2, an imaging unit, and a light guide fiber bundle The fragmentary sectional view of the front-end | tip part which shows the modified example by which the inclined surface which spreads on the outer side of radial direction was provided in the base end side of the front-end | tip hard member of FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The drawings are schematic, and it should be noted that the relationship between the thickness and width of each member, the ratio of the thickness of each member, and the like are different from the actual ones. Of course, the part from which the relationship and ratio of a mutual dimension differ is contained.

FIG. 1 is a partial perspective view showing an endoscope provided with the distal end portion of the endoscope of the present embodiment on the distal end side of the insertion portion.
As shown in FIG. 1, the endoscope 1 includes an insertion portion 2 that is elongated along the longitudinal axis direction N and has flexibility, an operation portion 3 provided on the proximal end side of the insertion portion 2, The main part is composed of a universal cord 5 extending from the operation unit 3 and a connector (not shown) connected to an image processing device and a light source device (not shown) provided at the extension end of the universal cord.

The insertion portion 2 includes, in order from the distal end side, a distal end portion 11 in which an objective lens unit 20 and an imaging unit 30 (see FIG. 2) described later are provided, and a plurality of insertion portions 2 provided on the proximal end side of the distal end portion 11. The main part is composed of a bending portion 12 that can be bent in two directions, for example, two directions, and a flexible flexible tube portion 13 provided on the proximal end side of the bending portion 12.

Further, on the proximal end side of the operation unit 3, a remote switch 14 for performing image control instructions such as freeze and release, a bending operation lever 15 for bending operation of the bending unit 12, and the like are provided.
Next, the configuration of the tip 11 will be described with reference to FIGS. 2 is a partial cross-sectional view of the distal end portion of the insertion portion in the endoscope of FIG. 1, FIG. 3 is a partial cross-sectional view of the distal end portion along the line III-III in FIG. 2, and FIG. FIG. 5 is a partial perspective view showing the objective lens unit, the imaging unit, and the light guide fiber bundle in FIG. 2 in an enlarged manner.

As shown in FIG. 2, a distal end rigid member 28, an objective lens unit 20, an imaging unit 30, a case 40 that is a third frame member, and a light guide fiber bundle 50 are provided in the distal end portion 11. It has been.

The objective lens unit 20 transmits a lens frame 22 that is a second frame member, an objective lens 21 that is an optical member that transmits light incident on an image sensor 34 described later, and light incident on an image sensor 34 described later. The main part is composed of a plurality of optical systems 23 to 27 as optical members.

As shown in FIG. 4, the lens frame 22 is composed of a cylindrical member having an outer diameter R3 (R3 <R2) smaller than an outer diameter R2 of a pair of arc portions 31a (see FIG. 3) described later. The distal end side is fitted and fixed in a through hole 28n formed so as to penetrate the hard member 28 in the longitudinal axis direction N.

In addition, an objective lens 21 and a plurality of optical systems 23 to 27 are provided in the lens frame 22 in order from the front end side.

The imaging unit 30 includes an element frame 31 that is a first frame member,

cover glasses

32 and 33 that transmit light incident on the imaging element 34, an objective lens 21, a plurality of optical systems 23 to 27, a cover glass 32, The main part is composed of an image sensor 34 that images the inside of the subject via 33.

As shown in FIG. 3, the element frame 31 has a first outer peripheral surface 31g having a pair of arc portions 31a having an outer diameter R2 and facing each other, and a pair of plane portions 31b continuing to and facing the arc portions 31a. Is formed.

Further, as shown in FIG. 2, the front end side of the element frame 31 is fitted to the rear half of the outer periphery of the lens frame 22.

Further, a cover glass 32 is provided in the base end side of the element frame 31, and the front end face of the cover glass 33 attached to the front end face of the image sensor 34 is attached to the base end face of the cover glass 32. Has been. That is, the image sensor 34 is provided in the element frame 31.

The case 40 is made of a cylindrical member and covers the outer periphery of the objective lens unit 20 and the imaging unit 30 as shown in FIGS. That is, the element frame 31 and the lens frame 22 are provided in the case 40.

As shown in FIGS. 2 and 3, in the case 40, the first range 40n1 in which at least the element frame 31 is provided on the first inner peripheral surface 40n is larger than the outer diameter R2 of the arc portion 31a. It is formed on a cylindrical surface having a first diameter R1 (R1> R2).

Further, as shown in FIGS. 2 to 4, the case 40 has a lens frame on the first inner peripheral surface 40n as compared with the first diameter R1 of the first range 40n1 on the first inner peripheral surface 40n. The second diameter R4 of the second range 40n2 in which 22 is inscribed is formed to be small (R4 <R1).

Further, the case 40 has a second lens frame 22 provided in the third diameter R5 in the first range 40g1 in which the element frame 31 of the third outer peripheral surface 40g of the case 40 is provided. The fourth diameter R6 in the range 40g2 is formed small (R6 <R5).

That is, the case 40 is inclined in the radial direction R of the element frame 31 between the range in which the element frame 31 is installed and the range in which the lens frame 22 is installed, as it goes toward the tip side. It has a shape squeezed through the surface 43.

As a result, the third outer peripheral surface 40g of the case 40 is covered with the outer skin 70 whose front end is thread-bonded to the outer peripheral surface of the distal end rigid member 28 and the second range 40g2 of the third outer peripheral surface 40g of the case 40. In this case, the inclined surface 43 can prevent the outer skin 70 from being stepped.

Further, the outer diameter of the outer end of the outer skin 70 and the outer diameter of the bobbin adhering portion is prevented from protruding outside in the radial direction R from the outer diameter of the outer skin 70 covered on the outer periphery of the first range 40g1. .

The light guide fiber bundle 50 is inserted into the insertion portion 2, the operation portion 3, the universal cord 5, and a connector (not shown).

Further, as shown in FIGS. 2 to 5, the light guide fiber bundle 50 includes a pair of crescent-shaped portions 51 that transmit the illumination light supplied from the illumination device to the distal end portion 11 side, and the illumination light in the subject. The main part is comprised including the light emission end part 52 which irradiates, and the inclination part 53 which connects the crescent moon-shaped part 51 and the light emission end part 52 to the longitudinal direction N.

As shown in FIG. 5, the light guide fiber bundle 50 includes a circular portion 54 having a circular cross section, for example, at a rear portion of the crescent-shaped portion 51.

As shown in FIG. 3, the pair of crescent-shaped portions 51 is provided between the pair of flat surface portions 31b and the first range 40n1 on the first inner peripheral surface 40n, and has a crescent-shaped cross section. Each has a cross-sectional area A.

As shown in FIG. 4, the light emitting end portion 52 is connected to the distal end side of the pair of crescent-shaped portions 51 via inclined portions 53, and the distal end hard member 28 has a radius larger than that of the lens frame 22. The hole 28m is formed in an elongated and ring shape along the longitudinal axis direction N outside the direction R.

In addition, the light emitting end 52 is formed in a similar circular arc with the second inner peripheral surface 52n and the second outer peripheral surface 52g, and the second inner peripheral surface 52n is outside the radial direction R of the lens frame 22. It is provided in the semi-ring shaped hole 28m so as to be arranged.

Furthermore, as shown in FIGS. 4 and 5, the light emitting end portion 52 constitutes a pair of tip portions of a light guide fiber bundle 50 provided to face each other in the radial direction R. That is, in the present embodiment, the light emitting end portion 52 is constituted by a pair.

Further, as shown in FIGS. 2 to 5, the light emitting end portion 52 is formed in a semi-ring shape that is smaller in the radial direction R than the crescent-shaped portion 51 and is longer in the circumferential direction C. Yes. That is, the pair of light emitting end portions 52 are disposed so as to surround the outer periphery of the lens frame 22.

Accordingly, even if the light emitting end portion 52 is formed smaller in the radial direction R than the crescent moon-shaped portion 51, it is formed longer in the circumferential direction C. Therefore, the cross-sectional area A ′ of the light emitting end portion 52 is Is equal to the cross-sectional area A of the crescent-shaped portion 51.

That is, the number of fibers inserted into the light exit end 52 can be increased with the number of fibers inserted into the crescent-shaped portion 51 as an upper limit.

Note that the light emitting end portion 52 may be formed in a ring shape instead of a pair. According to this, even if the light emitting end portion 52 is made further smaller in the radial direction R than in FIG. 4, since it extends in the circumferential direction C, the cross-sectional area A ′ can be secured. The range in which the lens frame 22 is installed can be reduced.

Furthermore, as shown in FIGS. 2, 4, and 5, the light emitting end portion 52 is positioned narrower inward in the radial direction R than the crescent moon-shaped portion 51 via the inclined portion 53.

As a result, as shown in FIGS. 2 and 4, the light emitting end portion 52 has a semi-ring-shaped hole so that the maximum outer diameter R7 is smaller than the maximum outer diameter R8 of the crescent moon-shaped portion 51 (R7 <R8). It is provided at 28m.

In addition, since the structure of the front-end | tip part 11 of the other endoscope 1 is the same as the past, the detailed description is abbreviate | omitted.

As described above, in the present embodiment, the light guide fiber bundle 50 includes a pair of crescent-shaped portions 51, a light emitting end portion 52, and an inclined portion 53, and the main portion is configured. Further, the light emitting end portion 52 is positioned so as to be narrower inward in the radial direction R than the crescent-shaped portion 51 via the inclined portion 53, so that the maximum outer diameter R7 is the maximum outer diameter of the crescent-shaped portion 51. It was shown that it was formed smaller than R8.

The pair of crescent-shaped portions 51 are provided between the pair of flat surface portions 31b and the first range 40n1 on the first inner peripheral surface 40n, and the cross section is formed in a crescent shape. It was.

Further, the light emitting end portion 52 is formed in a semi-ring shape having a smaller size in the radial direction R and longer in the circumferential direction C than the crescent-shaped portion 51, and a second inner peripheral surface 52n is formed. It has been shown that it is provided in the half ring-shaped hole 28m so as to be arranged outside the lens frame 22 in the radial direction R.

Moreover, it was shown that the cross-sectional area A ′ of the light emitting end 52 is equal to the cross-sectional area A of the crescent moon-shaped part 51.

According to this, between the outer peripheral surface 31g of the element frame 31 and the first range 40n1 of the first inner peripheral surface 40n of the case 40, the pair of plane portions 31b and the first inner peripheral surface 40n A pair of crescent shaped portions 51 is provided between the first range 40n1. From this, the light guide fiber bundle 50 can be arranged without increasing the diameter of the distal end portion 11 around the imaging unit 30 as in the conventional case.

In addition, the light emitting end provided in the semi-ring-shaped hole 28m between the objective lens unit 20 and the second range 40n2 of the case 40 has a radial direction R through the inclined portion 53 rather than the crescent-shaped portion 51. It is located on the inside. Accordingly, the diameter of the distal end portion 11 around the objective lens unit 20 is set to the second range 40g2 on the outer peripheral surface of the distal end hard member 28 or the third outer peripheral surface 40g of the case 40, and the front end side of the outer skin 70 is wound with a bobbin. Even if it is done, the diameter can be made substantially the same as or smaller than the distal end portion 11 around the imaging unit 30.

Furthermore, the light emitting end portion 52 is formed in a semi-ring shape that is smaller in the radial direction R than the crescent-shaped portion 51 and is formed longer in the circumferential direction C. For this reason, even if the light emitting end portion 52 is arranged so as to surround the objective lens unit 20, it is possible to prevent an increase in diameter, and the light emitting end portion 52 is formed to be long in the circumferential direction C. Can be made equal to the cross-sectional area A of the crescent moon shaped portion 51.

For this reason, even if the light emitting end portion 52 is reduced in diameter in the radial direction R, it is possible to prevent a decrease in the amount of illumination light emitted from the light emitting end portion 52.

From the above, it is possible to provide the distal end portion 11 of the endoscope 1 having a configuration capable of increasing the amount of illumination light supplied from the light guide fiber bundle 50 into the subject while reducing the diameter.

In addition, hereinafter, a modification is shown using FIG. FIG. 6 is a partial cross-sectional view of the distal end portion showing a modified example in which an inclined surface extending radially outward is provided on the proximal end side of the distal end hard member of FIG. 2.

In the above-described embodiment, the case 40 is illustrated with an example in which the inclined surface 43 is formed.

Not limited to this, as shown in FIG. 6, an inclined portion 28k extending outward in the radial direction R is formed on the proximal end side of the distal end hard member 28, and on the outer periphery of the portion 28e proximal to the inclined portion 28k, Even if it is the structure which the front end side of case 40 which has a linear cylindrical shape fits, the effect similar to this Embodiment mentioned above can be acquired.

This application is filed on the basis of the priority claim of Japanese Patent Application No. 2017-086184 filed in Japan on April 25, 2017, and the above contents include the description, claims and drawings of the present application. Is quoted in

Claims

A first frame member in which a first outer peripheral surface is formed by a pair of opposing arc portions and a pair of opposing flat portions that are continuous to the arc portion and in which an image sensor is provided;
An optical member that is a cylindrical member having an outer diameter smaller than the outer diameter of the pair of arc portions and is provided on the distal end side of the first frame member and through which light incident on the imaging element is transmitted. A second frame member;
The first frame member and the second frame member are provided inside, and a first range in which at least the first frame member is provided on the first inner peripheral surface is larger than the arc portion. A third frame member formed as a cylindrical surface of a diameter of
A pair of crescent-shaped portions provided between the pair of flat surface portions and the first range of the first inner peripheral surface and having a cross-section formed in a crescent shape; and distal ends of the pair of crescent-shaped portions And the second inner peripheral surface and the second outer peripheral surface are formed in a similar arc, and the second inner peripheral surface is disposed on the outer side in the radial direction of the second frame member. And a light guide fiber bundle for illuminating illumination light from the light exit end, and having a light exit end having a maximum outer diameter smaller than the crescent-shaped portion,
An endoscope distal end portion characterized by comprising:
The third frame member has the first inner peripheral surface as compared to the first diameter in the first range in which the first frame member is provided in the first inner peripheral surface. The second diameter of the second range in which the second frame member is installed is small,
The fourth diameter of the second range on the third outer peripheral surface is smaller than the third diameter of the first range on the third outer peripheral surface of the third frame member. The distal end portion of the endoscope according to claim 1, wherein:
2. The endoscope according to claim 1, wherein the light emitting end portions are a pair of end portions of the light guide fiber bundle provided to face each other in the radial direction of the second frame member. Tip.
2. The inner side according to claim 1, wherein the light emitting end portion is smaller in size in the radial direction than the crescent-shaped portion and is longer in a circumferential direction of the second frame member. The tip of the endoscope.
The distal end portion of the endoscope according to claim 4, wherein a cross-sectional area of the crescent moon-shaped portion is equal to a cross-sectional area of the light emitting end portion.
5. The internal view according to claim 4, wherein a part of the second inner peripheral surface of the light emitting end portion is positioned so as to be narrowed inward in the radial direction with respect to the crescent moon-shaped portion. The tip of the mirror.