JPH07140329A - Wide-angle lighting device - Google Patents

Abstract

(57) [Abstract] [Purpose] To obtain a wide-angle illumination device capable of uniformly illuminating a wide range of illumination targets by using a thin light guide bundle. [Structure] The irradiation directions of two or more light guides 3 and 7 are changed, and their illumination ranges a and b are adjacent to each other. At this time,
A means 9 for changing the irradiation direction is provided at the tip of one or more light guides 7. The means for changing the irradiation direction is bending of the light guide tip, oblique polishing, a reflecting mirror 9 installed at the light guide tip, or a prism.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wide-angle illuminating device, and more particularly to a wide-angle illuminating device such as an endoscope which is capable of uniformly illuminating a wide range of illumination targets by using a thin light guide bundle.

[0002]

2. Description of the Related Art In a remote observation device such as an endoscope, in general, a light source such as a light bulb is provided directly at the tip of an objective part or a flexible light guide is used to illuminate an observation target. Is used. Of these, the method of directly arranging a light source such as a light bulb at the tip can be used for wide-angle illumination, but since the tip has an electric system instrument, the aperture is large and it is not possible to reduce the diameter of the objective part. In addition, there is a risk of damage to the objective lens device and the object to be observed due to heat generation, and further damage of the light bulb or electric leakage or sparks. Especially for medical use, it is difficult to adopt for all the above reasons. On the other hand, if a light guide is used, a special device is not required at the tip portion, so that the diameter of the objective portion can be reduced, and there is no danger of heat generation or electric leakage at the tip portion. Therefore, recently, a light guide is often used for illumination in a remote observation device such as an endoscope.

[0003]

In a remote observation apparatus, the objective section is often inserted through a thin, non-linear insertion port, so the light guide used for this is usually a bundle of many optical fibers. , Is formed to have flexibility. Since the illumination light travels in each of these optical fibers while repeating interface reflection, and is emitted from the tip,
The illuminating light emitted from the light guide generally has a diverging irradiation angle, and the irradiation range of the illumination target is larger than the aperture of the light guide. However, since the diameter of the optical fiber is small, this irradiation angle is usually as narrow as about 50 ° or less. Therefore, for example, even if a plurality of light guides are annularly arranged around the objective lens, it is difficult to uniformly illuminate the range of the observation target that can be received by the wide-angle objective lens.

Therefore, as shown in FIG. 5, a plurality of light guides 14 are annularly arranged around the image fiber 1 having the objective lens 2 mounted on the tip portions thereof, and the tip portions of the respective light guides 14 are A method has been proposed in which a wide-angle lens system 15 is provided to increase the irradiation angle. But,
In this method, the diameter of the tip of the light guide is increased because the lens system 15 is attached, and in the end, it does not contribute much to the reduction of the diameter of the objective portion of the remote observation device. Further, since the wide-angle lens system 15 is provided in each of the light guides 14, it becomes expensive.

Further, as shown in FIG. 6, a minute lens ring 17 is formed by integrally forming minute lenses 16 in parallel with each other at the tips of a plurality of light guides 14 arranged in an annular shape around the image fiber 1. The method of attaching is also proposed. However, this method uses each microlens 1 of the microlens ring.
Not only is it necessary to pay close attention to aligning the optical axes of 6 with the optical axes of the corresponding light guides 14, but it is also inconvenient because the production of such a minute lens ring itself requires a high cost. Is. Further, in any of the above methods, widening the irradiation angle of the light guide with the wide-angle lens causes a decrease in illuminance. The present invention has been made to solve the above problems, and an object thereof is to provide a wide-angle illumination device capable of uniformly illuminating a wide range of illumination targets by a simple means.

[0006]

[Means for Solving the Problems] The above problem is to change the irradiation directions of two or more light guides and to make the respective illumination ranges adjacent to each other so that a uniform illuminance can be obtained for a wide range of illumination targets. This can be solved by providing a wide-angle lighting device. Here, the “irradiation direction” means the direction of the central optical axis of the illumination light emitted from the light guide.
The "illumination range" refers to an illumination range in which substantially uniform illuminance is obtained on the illumination target surface. In the above, it is preferable that the wide-angle illumination device is provided with a means for changing the irradiation direction at the tip of one or more illumination light guides. Here, it is preferable that the means for changing the irradiation direction is bending of the tip portion of the light guide. The means for changing the irradiation direction is preferably oblique polishing of the tip. Alternatively, the means for changing the irradiation direction is preferably a reflecting mirror installed at the tip. Alternatively, the means for changing the irradiation direction is preferably a prism installed at the tip.

[0007]

Even if the irradiation angles of the individual light guides are narrow, if the irradiation directions of the two or more light guides are changed and the illumination ranges of the respective light guides are arranged so as to be adjacent to each other, they will be respectively Will illuminate adjacent sections of each other that are illuminated. Therefore, by setting the number and arrangement of the light guides according to the size and pattern of the illumination target, it is possible to illuminate the illumination target in a desired range with uniform illuminance. As a means for changing the irradiation direction, there is also a method of arranging two or more linear light guides inclined with respect to the illumination target, but when the light guides are flexible, at least some of the light guides are If a means for changing the irradiation direction is provided at the tip end, it is possible to combine two or more light guides into a small-diameter bundle and achieve the above-mentioned object.

There are various means for changing the irradiation direction of the tip portion. For example, the tip of the flexible light guide may be bent. As a result, the irradiation direction of the light guide changes. Also, the tip may be obliquely polished. As a result, the irradiation direction changes to the direction of the polished slope. A reflector may be provided at the tip of the light guide. Thereby, the irradiation direction is changed unless the incident angle of the light from the light guide with respect to the reflecting mirror is 0 or right angle. Furthermore, even if a prism is provided at the tip of the light guide,
Similarly, the irradiation direction changes.

[0009]

EXAMPLES Next, the present invention will be described in more detail by way of examples. (Embodiment 1) The embodiment shown in FIG. 1 is an endoscope, and has a wide-angle illumination device of the present invention in which the tip end of a light guide is bent to change the irradiation direction. In FIG. 1, an image fiber 1 passes through the axis of the endoscope 21, and an objective lens 2 is attached to the tip of the objective part of the endoscope 21. The image fiber 1 and the objective lens 2 form an image transmission system. There is. The wide-angle illumination device of the present invention is mounted around the image transmission system.

This wide-angle illuminating device includes a plurality of linear light guides 3 arranged in a ring around the image transmission system, and an annular wedge 4 fitted to the outer periphery of the tip portion and increasing in diameter toward the tip portion. The linear light guide 3 has a plurality of bent light guides 5 which are arranged in parallel on the outer periphery of the linear light guide 3 and whose tip portions are bent along the inclination of the annular wedge 4. Therefore, the plurality of bent light guides 5 have a trumpet shape whose diameter increases in the direction of the tip along the inclination formed by the annular wedge 4. Each of the linear light guide 3 and the bent light guide 5 is configured by bundling a large number of optical fibers, and the rear end portions thereof are each optically connected to a light source system, although not shown.

Illumination light that has entered the linear light guide 3 from the light source system is emitted from the tip of the light guide at a constant irradiation angle of about 50 °, and on the observation target surface of the image transmission system, that is, the illumination target surface X, A constant illumination range a is formed. The optical axis 3a of this illumination light is parallel to the optical axis of the image transmission system.

On the other hand, the illumination light that has entered the bent light guide 5 from the light source system is bent along the bending of the light guide and is emitted from the tip. Therefore, this illumination light has an optical axis 5b that is not parallel to the optical axis 3a, and forms an illumination range b outside the illumination range a. The illumination ranges a and b are adjusted by adjusting the inclination angle formed by the annular wedge 4.
Since they can be adjacent to each other, both illumination ranges can be continuous so that a wide range of illumination targets can be illuminated with uniform illuminance. That is, in this wide-angle illuminator, a plurality of linear light guides 3 arranged in a ring around the image transmission system have their respective illumination ranges adjacent to each other so that a circular illumination including the axis of the image transmission system is provided. A plurality of bent light guides 5 that form a range and are annularly arranged side by side on the outer circumference of the linear light guide 3 and whose tip ends are bent outward are annular illumination ranges adjacent to the periphery of the circular illumination range. Is formed, which enables wide-area illumination as a whole.

(Embodiment 2) Embodiment 2 shown in FIG. 2 has a wide-angle illuminator in which the tip end portion of a light guide is obliquely polished to change the irradiation direction. In FIG. 2, an endoscope 22 includes a plurality of linear light guides 3 arranged in an annular shape around an image transmission system composed of an image fiber 1 and an objective lens 2 arranged in an axial center portion, The linear light guide 3 has a plurality of slanting polishing light guides 6 arranged in an annular shape on the outer circumference thereof. The tip end of each of the oblique polishing light guides 6 is obliquely polished, and each of the oblique polishing light guides 6 is arranged so that the polishing surface thereof faces outward with respect to the axis of the image transmission system. ing. Each of the linear light guide 3 and the slanted polishing light guide 6 is configured by bundling a large number of optical fibers, and the rear end portions thereof are optically connected to the light source system, although not shown. .

The illumination light incident on the linear light guide 3 is radiated from the tip of the light guide at a constant irradiation angle of about 50 °, as in the case of the first embodiment, and is illuminated on the surface X to be illuminated. A range a is formed. The optical axis 3a of this illumination light is parallel to the optical axis of the image transmission system.

On the other hand, the illumination light incident on the oblique polishing light guide 6 is the same as the light emitted from the vicinity of the top 6c of the polishing surface.
Since the light emitted from the vicinity of the bottom portion 6d has a different distance to reach the illumination target surface X, an elliptical illumination range b is formed on the surface X, and its optical axis 6b is a direction away from the optical axis of the image transmission system. Turn to. That is, the irradiation direction of the light guide 6 is changed by the oblique polishing. The illumination ranges a and b can be adjacent to each other by adjusting the inclination angle of oblique polishing. Therefore, by doing so, both illumination ranges can be made continuous so that uniform illuminance can be obtained on the illumination target surface X in a wide range. Since the plurality of linear light guides 3 and the slanted polishing light guides 6 are formed in an annular shape around the image transmission system, respectively, by arranging the respective illumination ranges adjacent to each other, the axis center of the image transmission system is made as a whole. A wide range of lighting around the center becomes possible.

(Embodiment 3) Embodiment 3 shown in FIG. 3 has a wide-angle illumination device in which a reflecting mirror is installed at the tip of a light guide to change the irradiation direction. In FIG.
The endoscope 23 includes the image fiber 1 disposed in the axial center portion.
A plurality of linear light guides 3 arranged in an annular shape around the image transmission system including the objective lens 2 and a plurality of light guides 7 with reflecting mirrors arranged in an annular shape on the outer periphery of the linear light guide 3. And have. The light guide 7 with a reflecting mirror is provided with a reflecting mirror 9 for reflecting the illumination light emitted from the end surface 8 of the light guide 7 in the direction of the illumination target surface X at the tip thereof.

The reflecting mirror 9 has its mirror surface tilted at an angle of 65 ° with respect to the end face 8 of the light guide, and is fixed to a pedestal 10 made of synthetic resin by adhesion. The gap 11 between the end face 8 of the light guide and the reflecting mirror 9 is filled with transparent plastic in order to maintain watertightness. The void may also be covered with a plastic or glass window instead of being filled with plastic. As the reflecting mirror 9, a metal mirror plated with nickel was used, but a metal plated with silver or a metal deposited with metal may be used. Each of the linear light guide 3 and the light guide 7 with a reflecting mirror is configured by bundling a large number of optical fibers, and the rear end portions thereof are optically connected to a light source system (not shown). There is.

The illumination light incident on the linear light guide 3 is emitted at an irradiation angle of about 50 ° from the tip of the light guide, as in the case of the first embodiment, and a constant illumination range a on the illumination target surface X is obtained. To form. Optical axis 3a of this illumination light
Is parallel to the optical axis of the image transmission system.

On the other hand, since the illumination light incident on the light guide 7 with a reflecting mirror is reflected by the reflecting mirror 9 at a shallow angle of 25 °, an elliptical illumination range b is formed on the surface X and its optical axis 7b is formed. Bends away from the optical axis of the image transmission system. That is, the irradiation direction of the light guide 7 is changed by 50 ° by the reflecting mirror 9. By arranging the illumination ranges a and b adjacent to each other, it is possible to apply a uniform illuminance to the illumination target surface X in a range of approximately 100 °. This total irradiation angle can be changed by adjusting the tilt angle of the reflecting mirror 9. Since the plurality of linear light guides 3 and the light guide 7 with the reflecting mirror are formed in an annular shape around the image transmission system, by adjoining the respective illumination ranges, the axis center of the image transmission system as a whole can be obtained. A wide range of lighting around the center becomes possible.
In particular, since the wide-angle illuminator having the light guide 7 with the reflecting mirror can illuminate a very wide area by adjusting the inclination angle of the reflecting mirror 9, it is necessary for wide-angle observation of the inner spherical surface such as a gastric camera. It is suitable for lighting.

(Embodiment 4) Embodiment 4 shown in FIG. 4 has a wide-angle illuminator in which a prism is installed at the tip of a light guide to change the irradiation direction. In FIG. 4, an endoscope 24 includes a plurality of linear light guides 3 arranged in an annular shape around an image transmission system composed of an image fiber 1 and an objective lens 2 arranged in an axial center portion, The linear light guide 3 has a plurality of prism-shaped light guides 12 arranged in an annular shape on the outer periphery of the linear light guide 3. The light guide 12 with the prism has an optical axis 12 of the illumination light emitted from the end surface 8 of the light guide 12 at the tip thereof.
A prism 13 that refracts b in a direction away from the optical axis of the image transmission system is installed.

Each of the linear light guide 3 and the light guide 12 with a prism is constructed by bundling a large number of optical fibers, and the rear ends thereof are not shown in the drawing but are optically connected to the light source system. Has been done.

The illumination light incident on the linear light guide 3 is emitted at an irradiation angle of about 50 ° from the tip of the light guide, as in the case of the first embodiment, and a constant illumination range a on the illumination target surface X is obtained. To form. Optical axis 3a of this illumination light
Is parallel to the optical axis of the image transmission system.

On the other hand, the illumination light incident on the light guide 12 with prism is radiated from the end face 8 and then the prism 1
Optical axis 12b which is refracted by 3 and is not parallel to the optical axis 3a
And an illumination range b is formed outside the illumination range a. The illumination ranges a and b can be adjacent to each other by adjusting the inclination angle of the prism 13. Therefore, it is possible to make both illumination ranges continuous and illuminate a wide range of illumination target surface with uniform illuminance. That is, in this wide-angle illuminator, a plurality of linear light guides 3 arranged in a ring around the image transmission system form an inner circular illumination range by adjoining the respective illumination ranges, and the linear light guide 3 is linear. A plurality of light guides 12 with prisms, which are arranged in an annular shape on the outer circumference of the light guide 3 and whose optical axis 12b is bent outward, form an annular illumination range adjacent to the circumference of the circular illumination range. As a wide range of lighting is possible.

In each of the above embodiments, the typical means for changing the irradiation direction at the tip of the light guide has been described, but it goes without saying that other means or a combination of these means can also be used advantageously. Yes. For example, in the means for bending the tip portion outward in Example 1, the tip portion has a large diameter. Therefore, if this is combined with the oblique polishing as shown in the second embodiment, it is possible to obtain a wide-angle illuminating device capable of illuminating a wider angle without increasing the diameter of the tip portion. Further, each of the above embodiments is an endoscope, but the present invention is not limited to this,
It can be widely applied to wide-angle illumination such as other remote observation devices or various displays.

[0025]

Since the wide-angle illumination device of the present invention changes the irradiation direction of two or more light guides and the illumination ranges are adjacent to each other, even if the illumination range of the light guide itself is narrow, it is wide. The illumination target can be illuminated with a uniform illuminance. At this time, if a means for changing the irradiation direction is provided at the tip of one or more light guides, the illumination range can be expanded using a bundle of light guides having a small diameter. If the means for changing the irradiation direction at this time is the bending of the tip of the light guide, it is possible to obtain a wide-angle illumination device that is extremely easy and inexpensive to manufacture. If the means for changing the irradiation direction at this time is oblique polishing of the light guide tip, a wide-angle illumination device can be obtained without increasing the diameter of the light guide tip and without requiring any special additional device. Further, if the means for changing the irradiation direction at this time is a reflecting mirror installed at the tip of the light guide, the bending angle of the irradiation direction can be largely changed by changing the inclination angle of this reflecting mirror, and thus the ultra wide angle A wide-angle lighting device that can be illuminated is obtained. Furthermore, if the means for changing the irradiation direction is a prism installed at the tip of the light guide, it is possible to change the bending angle of the irradiation direction in a wide range as in the case of a reflecting mirror, and a wide-angle lens capable of ultra-wide-angle illumination. A lighting device is obtained.

[Brief description of drawings]

FIG. 1 is a sectional view (a) showing an embodiment of a wide-angle lighting device of Embodiment 1 and a side view (b) viewed from the side of an illumination target.

FIG. 2 is a cross-sectional view showing an embodiment of a wide-angle illumination device of Example 2.

FIG. 3 is a cross-sectional view showing an embodiment of a wide-angle illumination device of Example 3.

FIG. 4 is a cross-sectional view showing an embodiment of a wide-angle illumination device of Example 4.

FIG. 5 is a sectional view showing an embodiment of a conventional example of a wide-angle lighting device.

FIG. 6 is a cross-sectional view (a) showing another embodiment of the conventional wide-angle illumination device and a side view (b) viewed from the side of the illumination target.

[Explanation of symbols]

3, 5, 6, 7, 12 ... Light guide, 9 ... Reflector, 1
3 ... Prism, 3a, 5b, 6b, 7b, 12b ... Light guide optical axis, a, b ... Illumination range, X ... Illumination target surface.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Ryo Tatekawa 1-5-1, Kiba, Koto-ku, Tokyo Fujikura Ltd. (72) Inventor Masayuki Otomo 4-83 33, Shibaura, Minato-ku, Tokyo KANDENKO (72) Inventor Hideo Kawasaki 4-83-3 Shibaura, Minato-ku, Tokyo KANDENKO Co., Ltd.

Claims (6)

[Claims] 1. A wide-angle illumination device in which the irradiation directions of two or more illumination light guides are changed and the respective illumination ranges are adjacent to each other so that uniform illumination can be obtained for a wide range of illumination targets. 2. The wide-angle lighting device according to claim 1, wherein a means for changing the irradiation direction is provided at the tip of one or more light guides for lighting. 3. The wide-angle lighting device according to claim 2, wherein the means for changing the irradiation direction is bending of the tip of the light guide. 4. The wide-angle illumination device according to claim 2, wherein the means for changing the irradiation direction is oblique polishing of the tip portion of the light guide. 5. The wide-angle illumination device according to claim 2, wherein the means for changing the irradiation direction is a reflecting mirror installed at the tip of the light guide. 6. The wide-angle lighting device according to claim 2, wherein the means for changing the irradiation direction is a prism installed at the tip of the light guide.