JPH03141316A - Light guide fiber cable - Google Patents

Abstract

PURPOSE:To eliminate unequal illumination in distributed light and to enable an observation screen to be brightly observed when the fiber cable is inserted into an endoscope, etc., by providing the fibers disposed at the exit end face on the front end side where the number of fibers is little in the position where the illumination light entering from the end face of a connector side is communicated with the fiber near the central part. CONSTITUTION:This cable is arranged with the fibers relatively more with the number of the light guide fibers near the sectional center 40b on the side 32b where the number of the light guide fibers in the forced or branched exit ends on the front end side is little in the fiber terminal part 40 on the side to be connected to a light source device 41. The illumination light is nearly evenly distributed even to the side 32b where the number of fibers is little on the forked or branched front end side of the light guide fiber cable and, therefore, the unequal illumination is lessened. A shadow is made by the illumina tion light at the time of projecting forceps when this cable is used for an endo scope, etc., having a forceps channel but the shadow is inconspicuous as the intensity of the illumination light is nearly uniformized.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a light guide fiber cable that guides illumination light emitted from a light source device to a light guide fiber of an endoscope or the like.

[Conventional technology]

There are two types of endoscopes: fiberscopes, which use an eyepiece to observe through an image guide fiber, and electronic scopes, which use a solid-state image sensor to observe on a monitor. Built-in light guide fiber. The respective tips of the image guide fiber, the solid-state image sensor, and the light guide fiber are guided and arranged near the end surface of the distal end of the insertion section. These are designed to be arranged so that the limited area on the end surface of the distal end of the insertion section can be used effectively, but in particular, as shown in FIG. 4, the light guide fiber 1 for illumination is One end is provided on the end surface 6 of the distal end section 5 of the insertion section 4 extending from the section 3, and the other end is fixed to the end surface 9 of the connector section 8 via the universal cord 7 from the operation section 3. By connecting this connector section 8 to the light source device 10, illumination light is emitted from the end surface of the light guide fiber 1 via the end surface 6 of the distal end section 5 of the insertion section 4. This light source device 10 includes a fifth
As shown in the figure, a light source 11 made of a halogen lamp, a xenon lamp, or the like is disposed with a condenser mirror 12 covered with an elliptical mirror, a parabolic mirror, or the like. Connector part 8 is a light source! 10, the illumination light from this light source 11 is focused on the end face 9 of the connector portion 8 either directly or by being reflected by the condenser mirror 12, and the illumination light is incident on the light guide fiber 1. 9 At this time, the illuminance distribution of the illumination light focused on the end face 9 of the connector part 8 is as shown in Figure 6.The illuminance of the illumination light is highest near the center of the optical axis and increases as the distance increases toward the periphery. It becomes darker as it goes, and shows a distribution that is rotationally symmetrical about the optical axis.

For this reason, there are some devices in which the incident light having a biased light intensity distribution at the input end face is outputted from the output end face to become a luminous flux with a uniform light intensity distribution.

For example, as disclosed in Japanese Patent Application Laid-Open No. 62-17705, fiber strands are twisted so that the arrangement on the output end surface is irregularly dispersed with respect to the arrangement of the fiber strands on the input end surface on the connector side, and It is configured such that the incident light beam is divided into a plurality of parts and uniformly distributed on the other end face.

On the other hand, in order to increase the amount of illumination light and improve the resolution, there is a light guide fiber in which the rear end portion of the light guide fiber is branched into two. This is shown in FIG. 7, and in this case, one of the illumination light output ends 13
is shown with a larger diameter than the other output end 14. However, since the light amount of the light guide fiber 1 is distributed only by the number of fiber strands, the amount of illumination light is greater at the output end 13 than at the output end 14.

[Problem that the invention seeks to solve]

However, if you want to equalize the brightness at both output ends, you can increase the number of fiber strands, but when the tip side of the light guide fiber is branched into two, the light guide fiber becomes thicker. In particular, with endoscopes, etc., if the tip is not made as thin as possible, it will be painful when inserted into the patient's body cavity.Therefore, there are restrictions when incorporating the light guide fiber into the insertion part of the endoscope, and the illumination light Since the number of fiber strands at the output end of the apparatus is often changed, there is a problem in that the amount of output light becomes uneven, resulting in uneven illumination in the observed image.

The present invention has been made by focusing on the above-mentioned problems.1. The purpose is to provide a light guide fiber cable that can provide uniform illumination light at the output end even if the number of light guide fiber strands for illumination is uneven on the two-pronged end side. shall be.

(Means and effects for solving the problems) In order to solve the above problems, the present invention guides illumination light emitted from a light source device to a light guide fiber, and branches it into two at the output end side of the illumination light. In a light guide fiber cable in which the number of light guide fiber strands is divided unevenly, the number of light guide fiber strands near the center of the cross section at one end of the fiber on the side connected to the light source device is on the tip side. A relatively large number of light guide fibers are arranged at the output end of the bifurcated output end where the number of light guide fibers is smaller.

Therefore, since the illumination light is almost evenly distributed even on the end side of the light guide fiber cable where the number of fiber wires is smaller, uneven illumination is reduced. Furthermore, when used in an endoscope or the like having a forceps channel, a shadow is formed by the illumination light when the forceps are protruded, but the intensity of the illumination light can be made approximately equal, so that the shadow becomes less noticeable.

〔Example〕

Hereinafter, the present invention will be specifically explained with reference to the drawings.

1 and 2 show a first embodiment of the present invention. FIG. 2 shows the structure of the distal end side of the insertion section of the endoscope, in which a rigid distal end component 20 is formed at the distal end, and a curved section (not shown) in the rear portion adjacent to the distal end component 20. is formed, and the curved portion can be bent by rotating a curved knob formed on the operating portion.

A tip component 21 formed into a columnar shape from a hard member such as metal is disposed in the tip component 20, and an imaging unit insertion hole 22 for capturing an observation image is disposed within the tip component 21.
and illumination insertion hole 23.2 for illuminating the observation area.
4 is provided.

An objective lens system 25 and an imaging section 26 are fixed to the imaging unit insertion hole 22 via a lens frame 27. Also, an illumination lens 22 is fixed to the tip side of the illumination insertion holes 23 and 24.
8.29 are fixed via lens frames 30.31. Behind the illumination lenses 28 and 29, a light guide fiber 32 as shown in FIG. .36 and is fixed as a light guide cable 37.

Further, the front end surface and the outer periphery of the tip component 21 are covered with an insulating cover 38, and the outer periphery of the tip component 21 on the rear end side of the cover 38 is covered with a flexible resin 39. Furthermore, although not shown in the figure, an air/water supply nozzle, an air/water channel tube, a treatment instrument channel, etc. are arranged in the distal end component 21 from the distal end side.

The light guide fiber 32b on the distal end side of the fiber 32 of the light guide fiber cable 37 shown in FIG.
The number of fiber strands is 32 light guide fibers.
It is less than a.

Further, the light guide fiber 32 is integrated on the connector side, and the number of fiber strands divided into light guide fibers 32b on the tip side at the end face 40 on the connector side is arranged at the center part 40b, and divided into light guide fibers 32a. The number of fiber strands is arranged in the peripheral portion 40a.

During endoscopic observation, the end face 40 of the light guide fiber 32 on the connector side is connected to the light source device 41 so that the light source 42 such as a halogen lamp or xenon lamp provided in the light source device 41 and the condenser mirror 43 The light is focused.

Next, the effect of irradiating the observation region with the illumination light of the light guide fiber cable 37 will be explained.

First, the illumination light emitted by the light source 42 provided in the light source device 41 is focused by the condenser ff 143 and enters the end face 40 of the light guide fiber 32 on the connector side. At this time, the illuminance distribution of the illumination light on the end face 40 on the connector side is brightest at the center and becomes darker toward the periphery. The incident light from the end face 40 is transmitted through the cotton of the light guide fiber 32, and the light with high illuminance is transmitted to the central part 40.
b is sent to the light guide fiber 32b on the distal side, which has a small number of branched fiber strands, and the relatively weak illumination light in the peripheral area 40a is sent to the light guide fiber 32b on the distal side, which has a large number of branched fiber strands. 32a
is sent to and emitted. Therefore, the output end surface 3 of the light guide fiber 32b on the tip side where the number of fibers is small.
4, illumination light with high illumination intensity is emitted, and illumination light with relatively low illumination intensity is emitted from the output end face 33 of the light guide fibers 32a on the distal end side, which has a large number of light guide fibers. However, due to the relationship between the numbers of light guide fibers 32a and 32b, the amount of illumination light emitted from each of the re-emission end faces 33 and 34 is approximately equal.

Even in the case of an endoscope with a light guide fiber cable branched into two branches with different numbers of fibers, the amount of illumination light emitted from the re-emission end face on the distal end side is approximately equal, so it is possible to illuminate the observation area. By irradiating light and uniformly brightening the viewing screen, a beautiful screen with even illumination can be obtained.

FIG. 3 shows a second embodiment of the invention. This embodiment differs from the first embodiment in the distribution of fibers on the end face of the light guide fiber on the connector side. The other configurations are the same as those in the first embodiment, and will therefore be omitted. A part of the peripheral part 40b from the vicinity of the center on the end face 44 on the connector side of the light guide fiber is the light guide fiber 32.
The peripheral portion 44a is disposed on the fiber 32b on the distal end side where the number of fiber strands branched into two is small, and the peripheral portion 44a is disposed on the fiber 32a on the distal side where the number of fiber strands is large.

By doing this, as in the first embodiment, the distribution of the illumination light amount is strong near the center, so that the two-pronged fiber has a substantially uniform light distribution on the tip side.

Therefore, a beautiful image without uneven illumination at the output end can be obtained.

It goes without saying that such a light guide fiber cable can be implemented in other types of equipment that can similarly utilize fiber cables for illumination, including fiberscopes such as endoscopes and electronic scopes.

〔Effect of the invention〕

As explained above, in the present invention, in a light guide fiber cable whose distal end is branched into two, illumination light incident from the end face on the connector side is transmitted to the center of the fiber arranged at the output end face on the distal end side where the number of fiber strands is small. Since it is installed in a position that communicates with nearby fibers, the illuminance of the light distribution near the center becomes stronger, and the illumination light on the output end side is almost averaged with the output end side with a large number of fibers/wires, resulting in a uniform light distribution. There is no uneven illumination, and a beautiful image with an evenly bright viewing screen can be observed, especially when inserted into an endoscope or the like.

[Brief explanation of the drawing]

L7 (not shown in Figure 1) Figure 2 shows the first embodiment of the present invention. Figure 1 is a perspective view of a light guide fiber cable whose distal end is branched into two, and Figure 2 is a perspective view of the distal end of an endoscope. FIG. 3 is a cross-sectional view of the light guide fiber cable incorporated in the second embodiment of the present invention, and FIG. 3 is an end view of the light guide fiber cable on the connector side, and FIGS. Figure 4 is an overall view of the light guide fiber cable installed in the endoscope, Figure 5 is a sectional view of the connector side of the light guide fiber cable connected to the light source device, and Figure 6 is one end surface of the light guide fiber in Figure 5. FIG. 7 is a sectional view of the distal end of the light guide fiber cable branched into two. 1.32-... Light guide fiber 32a
--- (many in number) light guide fiber 32b -- (in small number) light guide fiber 37 --- light guide fiber cable 10,
41-Light source device 40, 44-111 Connector side end face 40a, 44a--One peripheral portion 40tl-Central portion 44b--Near the center 0 2332a Also 2 I; 732 Bow light counterfeit

Claims (1)

[Claims] A light guide fiber is connected to a light guide fiber and a light source device, and the illumination light irradiated from the light source device is guided to the light guide fiber, and the light guide fiber is bifurcated into two with the number of fibers being divided unevenly at the output end side of the fiber. A light guide fiber cable, characterized in that, in the cable, an array near the center of the cross section of the end portion of the fiber on the side connected to the light source device is connected to an array with a smaller number of fibers on the tip side of the two prongs.