JPH10155731A - Endoscope - Google Patents

Abstract

(57) [PROBLEMS] An endoscope (laparoscopy) capable of uniforming the brightness of the entire image and improving the image quality by extending illumination by light emitted from an optical fiber 4 to a peripheral portion.
I will provide a. SOLUTION: An optical fiber 4 is arranged at a peripheral edge portion in a cylindrical body 2 so that a distal end portion is twisted, and light emitted from the end of the optical fiber 4 is spread to a peripheral portion and emitted. Also,
Most of the optical fibers 4 arranged at the peripheral edge in the cylindrical body 2 are terminated at the tip of the cylindrical body 2 and some of the optical fibers 4
Is terminated before the front end of the cylindrical body 2,
Light from the part of the optical fiber 4 supplements the illumination of the peripheral part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an endoscope used for endoscopy, laparoscopic surgery and the like.

[0002]

2. Description of the Related Art In laparoscopic surgery, several small holes are made in the abdomen of a patient, and a laparoscope, which is a type of endoscope, is inserted. A surgical operation is performed by inserting forceps or the like from another hole while watching.

As shown in FIG. 3, the laparoscope has a long cylindrical body 2 protruding from a main body 1 of the apparatus. The cylindrical body 2 is inserted into the abdomen to image the inside of the abdominal cavity from the tip. It has become. The cylinder 2 has a diameter of 1 cm as shown in FIG.
A large number of optical fibers 4 are bundled and arranged in a ring shape around the periphery of a pipe 3 made of stainless steel, and an imaging unit 5 is provided at the center surrounded by these optical fibers 4. is there. FIG. 4 shows a case where the optical fibers 4 are arranged three times in a pile at the periphery of the pipe 3. However, since the actual optical fibers 4 are extremely thin, about several thousand fibers are arranged in a multiplexed manner. Is done. Each optical fiber 4 is arranged straight and parallel along the axial direction of the cylindrical body 2, the gap is sealed with a resin or the like, and the optical fiber 4 is vertically cut at the tip of the cylindrical body 2 and terminated. And the device body 1
By transmitting light from a light source such as a halogen lamp in the inside and emitting the light from the end, a subject in front of the cylindrical body 2 is illuminated.

[0004] The image pickup section 5 comprises a cover glass 5a, a lens 5b and a CCD image pickup element 5c arranged in a central space surrounded by the optical fibers 4 in the cylindrical body 2. The cover glass 5 a is a transparent flat glass for closing the opening at the distal end of the cylindrical body 2 surrounded by the optical fibers 4 and sealing the inside, and the light from the front object illuminated by the optical fibers 4. And can be taken into the interior of the cylindrical body 2. The lens 5b is a cover glass 5a
This is an optical system for forming an image of light that has entered the cylindrical body 2 through the light-receiving surface of the rear CCD image sensor 5c. CCD
The image sensor 5c is an image sensor that converts an image of a subject formed by the lens 5b into an electric signal and outputs the electric signal as a video signal. Then, the video signal output from the CCD image pickup device 5c is sent to and displayed on an external monitor (not shown) via the apparatus main body 1 through the cable 5d.

[0005] Here, the image pickup section 5 in which the CCD image pickup device 5c is disposed in the cylinder 2 has been described. However, only an optical system including a plurality of lenses and the like is disposed in the cylinder 2, and the apparatus main body is provided. There is a case where the CCD image pickup device 5c is arranged on one side.

[0006]

However, since the optical fiber 4 emits the light almost straight without scattering the light at the end, the illuminance by this light becomes stronger as the front in the emission direction becomes the strongest and becomes closer to the periphery. Weakens. And
In the conventional laparoscope, the cylindrical body 2 passes through these optical fibers 4.
5, light is emitted straight forward from the tip of the optical fiber 4. Therefore, even if all the lights from the large number of optical fibers 4 are combined, the illuminance at the front central portion becomes the strongest and becomes weaker toward the periphery as shown in FIG. Therefore, when the CCD image pickup device 5c of the image pickup unit 5 picks up an image of a subject illuminated by such an optical fiber 4, the central portion of the image becomes extremely bright, but the peripheral portion rapidly becomes dark.

For this reason, in the conventional laparoscope, although the image displayed on the monitor is too bright in the central portion and the color jumps and becomes whitish due to halation, the peripheral portion is dark and the subject cannot be easily identified. This makes it difficult to see the monitor screen.

The light emitted from the optical fiber 4 tends to spread to the periphery because the light component (blue light) having a shorter wavelength has a larger refraction angle, and the peripheral portion becomes bluish like a donut. Moreover, since the optical axes of the light emitted from the large number of optical fibers 4 are at most about 1 cm apart from each other at the extreme ends, the bluish donut-shaped light of each optical fiber 4 overlaps with a slight deviation. The illumination of the peripheral portion in front of the cylindrical body 2 also becomes bluish. For this reason, the conventional laparoscope has a problem in that the peripheral portion of the image is bluish in a donut shape and the monitor screen is difficult to see.

Further, in order to solve the above problem, CC
By processing the video signal imaged by the D image sensor 5c with a computer, the technology of suppressing the halation at the center and increasing the signal brightness at the peripheral portion to make the brightness of the entire image uniform and then displaying it on a monitor has long been available. Proposed. However, when such computer processing is performed, a problem arises in that the edge of the subject is excessively emphasized at the center, and a black border-like false image appears. Further, in the peripheral portion, even if the brightness is increased, the roughness of the image due to insufficient exposure does not disappear, so that there is a problem that the texture of the subject cannot be displayed accurately.

The above problem is common to not only laparoscopes but also endoscopes in general.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an endoscope which can uniformly improve the brightness of the entire image and improve the image quality by sufficiently expanding the illumination by the optical fiber to the peripheral portion. It is intended to provide a mirror.

[0012]

That is, according to the first aspect of the present invention, at least each of the optical fibers of the cylindrical distal end is twisted and arranged in the same rotational direction, so that the optical fiber from the distal end of the cylindrical distal end is disposed. The emitted illumination light is emitted obliquely with respect to the cylindrical axis. Moreover, since the light emitted from the optical fibers arranged symmetrically with respect to the cylindrical axis is emitted in the opposite oblique directions, the light for illumination as a whole is emitted from the cylindrical tip. Irradiation spreads to the periphery. Accordingly, the cylindrical front subject is sufficiently illuminated not only in the central part but also in the peripheral part, so that the periphery of the image captured by the imaging unit does not become dark, and the entire subject has uniform brightness. Image can be obtained.

According to a second aspect of the present invention, by terminating a part of the optical fiber at a position closer to the front side than the cylindrical tip,
Light for illumination from the front end is emitted to the periphery. That is, when the optical fiber terminates closer to the front than the cylindrical tip, light emitted toward the front and light emitted inward from the end is blocked by the cylindrical tip, so that The light is emitted only to the peripheral portion. Therefore, the subject in front of the cylindrical shape is illuminated only in the central portion by the original light emitted from the end of the optical fiber at the cylindrical tip, and the peripheral portion is illuminated by the light from the front end. Also, the illumination is supplemented, so that the periphery of the image captured by the imaging unit does not become dark, and an image with uniform brightness can be obtained as a whole.

The optical fiber terminated before the cylindrical distal end has a terminal surface cut obliquely or a distal end bent outward so that emitted light can be efficiently disposed in a peripheral portion. Can be emitted.

[0015]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a first embodiment of the present invention, and shows a side view showing an arrangement state of an optical fiber by removing a pipe portion from a distal end portion of a cylindrical body of a laparoscope and illuminance characteristics. FIG. Components having the same functions as those of the conventional example shown in FIGS. 3 to 5 are denoted by the same reference numerals.

In this embodiment, a laparoscope will be described, but the present invention can be similarly applied to other endoscopes. The apparatus main body 1 of the laparoscope, the pipe 3 of the cylindrical body 2 and the imaging unit 5 have the same configuration as the conventional example shown in FIGS. The optical fibers 4 are also arranged in a ring shape in a bundle at the peripheral portion in the pipe 3, the gap is sealed with a resin or the like, and the optical fiber 4 is terminated at the tip of the cylindrical body 2. But,
As shown in FIG. 1, these optical fibers 4 are arranged at the distal end of the cylindrical body 2 so as to be twisted in the same rotational direction about the axis of the cylindrical body 2. That is, in FIG. 1, for example, the distal end of the optical fiber 4 arranged on the near side faces obliquely upward, and the optical fiber arranged 180 ° away from the back side of the drawing, which is not visible behind the optical fiber 4 on the near side. The distal end of the optical fiber 4 faces obliquely downward, the distal end of the upper optical fiber 4 faces obliquely rearward, and the distal end of the lower optical fiber 4 faces obliquely forward. Although FIG. 1 shows a case where these optical fibers 4 are arranged in a straight line along the axial direction except for the distal end portion of the cylindrical body 2, the optical fibers 4 may be twisted similarly to the distal end portion. . The optical fiber 4 in which at least the tip is twisted as described above transmits light from a light source such as a halogen lamp in the apparatus main body 1,
Light is emitted from the front end of the cylindrical body 2 by emitting the light from the end of the cylindrical body 2 that faces obliquely.

In the laparoscope having the above-described structure, the illuminance of the light from each optical fiber 4 is the strongest in front of the light emitting direction and becomes significantly weaker toward the periphery, as shown in FIG. However, since the end of each optical fiber 4 is directed obliquely toward the front side, the back side, or the upper and lower sides according to the respective arrangement positions, light is emitted in a direction that spreads around the axis of the cylinder 2 around the axis. I do. Therefore, when all the lights from these many optical fibers 4 are combined, as shown in FIG. 1, the illuminance due to the light from each optical fiber 4 greatly shifts and overlaps, and the region with high illuminance as a whole spreads to the periphery. become. That is, for example, in the case of the conventional laparoscope shown in FIG. 5, the angle range in which the illuminance has a peak half value is θ, and the torsion angle of each optical fiber 4 in the case of the laparoscope of the present embodiment shown in FIG. Then, in this case, the angle range in which the illuminance due to the light from all the optical fibers 4 is half the peak is widened to about θ + 2α. Further, even if the peripheral portion of the light from each optical fiber 4 becomes bluish in a donut shape, the light from each of the optical fibers 4 largely shifts and overlaps, so that the bluish color is not noticeable.

For this reason, when the laparoscope of the present embodiment captures an image of the subject illuminated by the optical fiber 4 with the CCD image pickup device 5c of the image pickup section 5, the entire image becomes uniform in brightness and the central portion is illuminated. The image quality can be improved because the image is not too bright or the peripheral portion is not darkened.

Since the pipe 3 is for protecting the optical fiber 4 and the image pickup unit 5, other materials may be used if necessary, or the pipe 3 may be omitted and the optical fiber 4 and the image pickup unit 5 may be omitted. It is also possible to constitute the cylindrical body 2 only by itself.

FIG. 2 shows a second embodiment of the present invention, and is a longitudinal sectional side view showing an arrangement state of optical fibers at a distal end portion of a tubular body of a laparoscope and a diagram showing illuminance characteristics. Note that components having the same functions as those of the first embodiment shown in FIG. 1 are denoted by the same reference numerals, and description thereof is omitted.

In this embodiment, a laparoscope will be described, but the present invention can be similarly applied to other endoscopes. The apparatus main body 1 of the laparoscope and the imaging section 5 of the cylindrical body 2 have the same configuration as that of the first embodiment shown in FIG. Also, the optical fiber 4 is arranged in a ring shape by bundling a large number of them at the peripheral portion in the pipe 3, the gap is sealed with a resin or the like, and light from a light source such as a halogen lamp in the apparatus main body 1 is blocked. The same is true for transmission and emission from the end. However, most of the optical fibers 4a are terminated by reaching the tip of the cylindrical body 2, but only the outermost optical fiber 4b is terminated by the front side of the distal end of the cylindrical body 2, and the end faces thereof are respectively. It is cut diagonally to face the outside. The pipe 3 that covers the entire periphery of the optical fiber 4 has a configuration in which a transparent resin pipe 3a is arranged only around the end of the outermost optical fiber 4b, and the front and rear portions are connected by stainless steel pipes 3b, 3b. Has become.

In the laparoscope having the above structure, the light from the optical fiber 4a that terminates at the tip of the cylindrical body 2 has the highest intensity at the front central portion and the weaker peripheral portion, as shown in FIG. Become. However, the outermost optical fiber 4b emits light from the end on the near side of the tip of the cylindrical body 2, and the pipe 3
The light is emitted only to the outer peripheral side through the resin pipe 3a.
Therefore, when the light from these two optical fibers 4a and 4b is combined, as shown in FIG. 2, the light from the optical fiber 4a at the outermost periphery is surrounded by the light from the optical fiber 4a that terminates at the tip of the cylindrical body 2. The light overlaps, and the illuminance in the peripheral portion is supplemented, so that an area with high illuminance expands. Further, even if the peripheral portion of the light from the optical fiber 4a that terminates at the tip of the cylindrical body 2 becomes bluish in a donut shape, the light from the outermost optical fiber 4b overlaps here, so that the bluish color is conspicuous. No more.

Therefore, when the laparoscope of the present embodiment captures an image of a subject illuminated by the optical fibers 4a and 4b with the CCD image pickup device 5c of the image pickup unit 5, the entire image becomes uniform in brightness. The image quality can be improved because the central portion is not too bright or the peripheral portion is not darkened.

The optical fiber 4b that terminates on the front side of the distal end of the cylindrical body 2 only needs to be a part of the entire optical fiber 4 disposed at the peripheral portion in the pipe 3, and is not necessarily required as in this embodiment. The optical fiber 4b is not limited to the outermost optical fiber 4b.
Further, in the present embodiment, the light is efficiently emitted to the outer peripheral side by obliquely cutting the end surface of these optical fibers 4b.
The same effect can be obtained even if the tip of b is disposed so as to face the outer periphery. Moreover, some of these optical fibers 4
Even if the end of b is arranged straight and the end face is cut vertically, the light utilization rate decreases, but it is possible to supplement the illuminance of the peripheral part in front of the cylinder 2. Pipe 3
As long as the light from the ends of these optical fibers 4b can be emitted to the outer peripheral side, it is not always necessary to combine the resin pipe 3a and the stainless steel pipes 3b, 3b as in the present embodiment. The pipe 3 can be omitted.

Further, in the present embodiment, the CC
Since the imaging unit 5 in which the D imaging element 5c is arranged is used, only the cable 5d is arranged in the center of the cylindrical body 2 closer to the apparatus main body 1 than the CCD imaging element 5c, so that a space is provided. Therefore, the same number of optical fibers 4a as in the prior art are terminated at the tip of the cylindrical body 2, and the outer circumference of the bundle of these optical fibers 4a is narrowed closer to the apparatus body 1 than the CCD image pickup device 5c. The optical fiber 4b is additionally provided. However, it is needless to say that the same number of optical fibers 4a and 4b as those in the related art may be arranged straight over the entire length, and a part of the optical fibers 4a and 4b may be terminated on the front side of the distal end of the cylindrical body 2.

[0027]

As is clear from the above description, according to the endoscope of the first aspect, by arranging the tip of each optical fiber by twisting, the light from these optical fibers is transmitted to the peripheral portion. Since the light is emitted so as to spread and sufficiently illuminates not only the central part but also the peripheral part, the image captured by the image capturing unit can be made uniform in brightness as a whole and the image quality can be improved.

Further, according to the endoscope of the present invention, a part of the optical fiber is terminated before the front end, so that the light from the optical fiber terminated on the front side illuminates the peripheral portion. Therefore, the image captured by the image capturing unit can be made uniform in brightness as a whole to improve the image quality.

[Brief description of the drawings]

FIG. 1 is a side view showing a first embodiment of the present invention, in which a pipe portion is removed from a distal end portion of a cylindrical body of a laparoscope, showing an arrangement state of an optical fiber and a diagram showing illuminance characteristics. is there.

FIG. 2, showing a second embodiment of the present invention, is a longitudinal sectional side view showing an arrangement state of optical fibers at a distal end portion of a tubular body of a laparoscope and a diagram showing illuminance characteristics.

FIG. 3 is an overall perspective view showing a configuration of a laparoscope.

FIG. 4 shows a conventional example, and is a longitudinal sectional side view and a front view showing a structure of a distal end portion of a tubular body of a laparoscope.

FIG. 5 is a side view showing a conventional example, in which a pipe portion is removed from a distal end portion of a cylindrical body of a laparoscope, showing a state of arrangement of optical fibers and a diagram showing illuminance characteristics.

[Explanation of symbols]

 2 cylindrical body 4 optical fiber 5 imaging unit

Claims (2)

[Claims] 1. An image pickup section for picking up an optical image incident from the cylindrical tip is provided at a central portion of the cylindrical shape, and an illumination portion is provided on a peripheral portion of the cylindrical shape from an end of the cylindrical distal end. In an endoscope in which a number of optical fibers that emit light are arranged, at least each of the optical fibers at the cylindrical tip is twisted and arranged in the same rotational direction about the cylindrical axis. An endoscope characterized by the following. 2. An image pickup unit for picking up an optical image incident from the tip of the tube is provided at the center of the tube, and an illumination unit is provided on the periphery of the tube from the end on the tip side of the tube. An endoscope in which a large number of optical fibers for emitting light are arranged, wherein some of the optical fibers are terminated at a position closer to a front side than a cylindrical distal end.