JP2017015836A - Perimeter illuminating optical member, and perimeter illuminating optical system for endoscope and perimeter observing endoscope comprising the optical member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a perimeter illuminating optical member, that illuminates an observation object across a lateral perimeter, by using light from illumination light supply means which is eccentrically arranged in an endoscope, with substantially uniform light intensity and high light utilization efficiency and in a bright manner hardly causing halation, and that decreases mirror reflection when observing inside a tube.SOLUTION: The perimeter illuminating optical member includes: a cylindrical part 11 with an aperture, having an inner peripheral surface 11a and an outer peripheral surface 11b that are composed of a transparent medium and respectively formed in a cylindrical shape at a position where they are mutually coaxial or non-coaxial, and having a front end part 11c and a rear end part 11d that are annularly formed and contact the inner peripheral surface and the outer peripheral surface respectively; and a total reflection surface 13 and an emission surface 14a for emitting a portion of the light incident by being directed so as to be capable of being totally reflected when incident on the total reflection surface, outside the cylindrical part with the aperture, in a direction oblique to the total reflection surface, that are alternately formed across a perimeter of the outer peripheral surface of the cylindrical part with the aperture.SELECTED DRAWING: Figure 2

Description

  The present invention provides, for example, an all-around illumination optical member for illuminating an observation object over the entire periphery of the side in an endoscope that observes the entire periphery of the side of a tubular observation object. The present invention relates to an all-around illumination optical system for an endoscope and an endoscope for all-around observation.

  Conventionally, as a technique for illuminating an observation object covering the entire periphery of a side, for example, in an inner surface shape measuring apparatus, a light emitting element (LED element) is provided inside a cylindrical outer peripheral portion having a plurality of slits in the circumferential direction. There is a configuration in which a plurality of slits are arranged side by side in the circumferential direction of the outer peripheral portion and the slit illumination light for measurement is emitted toward the entire periphery (see, for example, Patent Document 1).

JP 2014-149164 A

  By the way, in recent years, an endoscope is required to have a small diameter at the distal end portion of the endoscope. However, in the configuration in which the light emitting elements as described in Patent Document 1 are arranged in the circumferential direction of the cylindrical outer peripheral portion, a large space in the circumferential direction is taken and the diameter of the distal end portion of the endoscope is increased. In order to reduce the diameter of the distal end portion of the endoscope, it is necessary to have a configuration in which light from the illumination light supply means eccentrically arranged at the distal end portion of the endoscope is emitted toward the entire side.

However, it is difficult to illuminate the observation object over the entire side by using the illumination light supply means that is eccentrically arranged at the distal end portion of the endoscope.
As a method of illuminating the observation object over the entire side by using illumination light in the above configuration, it is conceivable to diffuse the illumination light using an optical member filled with a scattering material.
However, if you try to illuminate the observation target evenly over the entire side by using an optical member filled with a scattering material, the scattered light will be emitted in directions other than the observation target. Efficiency will decrease.

  In addition, the configuration of emitting slit illumination light toward the entire circumference described in Patent Document 1 is required to detect the position of the slit light projected on the test object to obtain the inner surface shape of the test object. The direction in which the surrounding specimen is irradiated with illumination light is such that the illumination light specularly reflected by the specimen enters the observation system. However, when the illumination light is used for observing the form of the inner surface of the tube, in the configuration described in Patent Document 1, some of the specularly reflected light causes halation, which hinders detailed image inspection of the inner surface of the tube. There is a fear.

  According to some aspects of the present invention, it is proposed in order to solve the above-described conventional problems, and is eccentrically arranged in an endoscope that observes the entire side of a tubular observation object. The illumination light from the illumination light supply means can be used to illuminate the observation object over the entire circumference of the side, with almost uniform light intensity, and high light utilization efficiency and bright illumination. All-round illumination optical member that can reduce the specular reflection light during in-tube observation and can irradiate illumination light that is easy to observe in the observation system with little halation, and for all-around illumination optical system for endoscopes and all-around observation The purpose is to provide an endoscope.

  In order to achieve the above object, an omnidirectional illumination optical member according to an aspect of the present invention provides light from illumination light supply means that is eccentrically arranged at the distal end portion of the endoscope to the entire periphery on the side of the endoscope distal end portion. An omnidirectional illumination optical member that illuminates toward an inner surface, an inner peripheral surface and an outer peripheral surface made of a transparent medium and formed in a cylindrical shape at positions that are coaxial or non-coaxial with each other, and the inner peripheral surface and the outer peripheral surface, A cylindrical portion with an opening having a front end portion and a rear end portion formed in contact with each other, and a total reflection surface and a total reflection surface formed alternately over the entire circumference of the outer peripheral surface of the cylindrical portion with an opening. And an exit surface that emits a part of the incident light in such a direction that it can be totally reflected when incident, to the outside of the cylindrical portion with the opening in an oblique direction with respect to the total reflection surface.

  An endoscope all-around illumination optical system according to one aspect of the present invention includes an illumination light supply unit, an all-around illumination optical member according to one aspect of the present invention, and a cylindrical shape that covers the periphery of the all-around illumination optical member. Sapphire cover glass.

  An all-around observation endoscope according to an aspect of the present invention includes an all-around illumination optical system according to an aspect of the present invention and a partial lens in the opening of the cylindrical portion with the opening. An objective optical system for observing an observation object over the surroundings is provided at the distal end portion of the endoscope.

  According to the present invention, in an endoscope that observes the entire side of a tubular observation object, the observation object that covers the entire periphery of the side using the illumination light from the eccentrically arranged illumination light supply means is used. , It can illuminate the light intensity almost evenly, can perform bright illumination with high light utilization efficiency, can reduce specular reflection light during in-tube observation, is less likely to cause halation, and is easy to observe in the observation system An omnidirectional illumination optical member capable of irradiating illumination light, an omnidirectional illumination optical system for an endoscope including the same, and an omnidirectional observation endoscope are obtained.

It is explanatory drawing which shows an example of schematic structure of the endoscope for all around observation provided with the all around illumination optical system for endoscopes of each embodiment of this invention. BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the structure of the omnidirectional illumination optical member concerning 1st Embodiment of this invention, (a) is a perspective view which shows the external appearance of the member located inside the cylindrical sapphire cover glass in an omnidirectional illumination optical member. (B) is the top view which looked at the omnidirectional illumination optical member from the incident side of light. It is explanatory drawing which shows the effect | action which diffuses and illuminates the light from an illumination light supply means to the structure of the member located inside the cylindrical-shaped sapphire cover glass in the all-around illumination optical member of FIG. (a) is a plan view seen from the light incident side, and (b) is an explanatory view of the main part seen from the lower side. It is explanatory drawing which shows the function of the output surface with which the all-around illumination optical member shown in FIG. 3 is equipped, (a) is a figure which shows typically the advancing direction of the light which injected into the output surface in the direction which can be totally reflected by a total reflection surface (B) is a diagram schematically showing the traveling direction of the light that is emitted from the emission surface of the all-around illumination optical member toward the observation target across the entire side and is specularly reflected by the observation target, and (c) is (c) As a comparative example of b), the traveling direction of the light that is specularly reflected by the observation target is shown in the omnidirectional illumination optical member in which the emission surface is configured to emit the illumination light in a state substantially perpendicular to the total reflection surface. FIG. The structure of the member located inside the cylindrical sapphire cover glass in the all-around illumination optical member according to the comparative example of the first embodiment is combined with the action of diffusing and illuminating the light from the illumination light supply means to the entire periphery. FIG. 4A is a plan view seen from the light incident side, and FIG. 4B is an explanatory diagram of a main part seen from the side. The structure of the member located inside the cylindrical sapphire cover glass in the all-around illumination optical member according to the second embodiment of the present invention is combined with the action of diffusing and illuminating the light from the illumination light supply means to the entire periphery. (A) is a plan view seen from the light incident side, (b) is a perspective view showing the main part shape of the member located inside the cylindrical sapphire cover glass in the all-around illumination optical member It is. The structure of the member located inside the cylindrical sapphire cover glass in the all-around illumination optical member according to the third embodiment of the present invention is combined with the action of diffusing and illuminating the light from the illumination light supply means to the entire periphery. (A) is a plan view viewed from the light incident side, and (b) is an explanatory diagram of a main part viewed from the lower side. The top view which looked at the structure of the member located inside the cylindrical sapphire cover glass in the omnidirectional illumination optical member concerning 4th Embodiment of this invention from the incident side of light, (a) shows the example FIG. 2B is a diagram showing another example. The top view which looked at the structure of the member located inside the cylindrical sapphire cover glass in the omnidirectional illumination optical member concerning 5th Embodiment of this invention from the incident side of light, (a) shows the example. FIG. 2B is a diagram showing another example. It is explanatory drawing which shows notionally the omnidirectional illumination optical member of the further another example of this invention, (a) is a figure which shows the advancing direction of the light in the omnidirectional illumination optical member in the example, (b) is another figure. The figure which shows the advancing direction of the light in the all-around illumination optical member concerning an example, (c) is the composition of the member located inside the cylindrical sapphire cover glass in the all-around illumination optical member concerning other examples. Conceptual perspective view, (d) is a plan view of the member shown in (c) seen from the side of the illumination light supply means, (e) is a state where the illumination light supply means is arranged on the member shown in (d). (F) is a diagram conceptually showing the configuration of a member located inside a cylindrical sapphire cover glass in an all-around illumination optical member according to still another example, the illumination light supply means It is a side view which shows the state which has arrange | positioned.

  Hereinafter, embodiments of the present invention will be described. The embodiment described below does not unduly limit the contents of the present invention described in the claims. In addition, all the configurations described in the following embodiments are not necessarily essential configuration requirements in the present invention.

  The omnidirectional illumination optical member according to the embodiment of the present invention is an omnidirectional illumination that illuminates light from illumination light supply means eccentrically arranged at the distal end portion of the endoscope toward the entire circumference on the side of the distal end portion of the endoscope. An optical member made of a transparent medium and formed in an annular shape in contact with the inner peripheral surface and the outer peripheral surface, and the inner peripheral surface and the outer peripheral surface, which are formed in a cylindrical shape at coaxial or non-coaxial positions, respectively. A cylindrical portion with an opening having a leading end portion and a rear end portion, and a total reflection surface that is alternately formed over the entire circumference of the outer peripheral surface of the cylindrical portion with the opening, and is totally reflected when incident on the total reflection surface. And a light exit surface that emits a part of the light incident in a direction that can be transmitted to the outside of the cylindrical portion with the opening in an oblique direction with respect to the total reflection surface.

  Like the omnidirectional illumination optical member of the embodiment of the present invention, an inner peripheral surface and an outer peripheral surface, and an inner peripheral surface and an outer peripheral surface, which are made of a transparent medium and are formed in a cylindrical shape at coaxial or non-coaxial positions, respectively. If there is a cylindrical portion with an opening having a tip portion and a rear end portion that are annularly in contact with each other, the light from the illumination light supply means that is eccentrically arranged at the tip portion of the endoscope is transmitted to the inside of the cylinder portion with the opening. By propagating, it becomes possible to illuminate the entire periphery of the endoscope distal end side.

Further, like the all-round illumination optical member of the embodiment of the present invention, when the light is incident on the total reflection surface and the total reflection surface that are alternately formed over the entire circumference of the outer peripheral surface of the cylindrical portion with the opening, the total reflection is performed. If there is an exit surface that emits part of the incident light in a possible direction to the outside of the cylindrical portion with the aperture, the light from the illumination light supply means that is eccentrically arranged at the distal end portion of the endoscope is the cylindrical portion with the aperture The incident light from the illumination light supplying means is incident from the direction of the imaginary line passing through the cylindrical shape of the inner peripheral surface of the cylindrical portion with the opening and the cylindrical shape of the outer peripheral surface. The outer periphery of the cylindrical portion with the opening is repeated by repeating the reflection action of the total reflection surface formed over the entire circumference of the outer peripheral surface of the cylindrical portion with the opening when it is supplied to the inside of the cylindrical portion with the opening. All of the sides while diffusing light around the entire surface It is possible to perform illumination to observation target toward the circumference.
In addition, if the total reflection surface and the exit surface are alternately formed over the entire circumference of the outer peripheral surface of the cylindrical portion with an opening, it is often increased from the outer peripheral surface in the vicinity of the incident position of light from the light guide arranged eccentrically at the distal end portion of the endoscope. It becomes easy to emit a certain amount of light over the entire circumference of the outer peripheral surface of the cylindrical portion with the opening without emitting the light. As a result, illumination with a uniform amount of light can be performed toward the entire periphery on the side of the distal end portion of the endoscope.
In addition, when the exit surface is incident on the total reflection surface, a part of the incident light in such a direction that it can be totally reflected is emitted to the outside of the cylindrical portion with the opening in an oblique direction with respect to the total reflection surface. In this case, the light exiting from the exit surface becomes light that illuminates the observation target across the entire side, and the specular reflected light from the observation target passes through the incident end of the side observation system of the endoscope. It becomes easy to come off. As a result, the specular reflection light at the time of in-tube observation can be reduced, and illumination light that can be easily observed by the observation system can be irradiated.
This point will be further explained. The omnidirectional illumination optical member of the embodiment of the present invention is premised on being applied to an endoscope for observing an observation object over the entire circumference on the side. In an endoscope that observes an observation object that covers the entire periphery of the side, the observation system enters light from the observation object that covers the entire periphery of the side, and forms an image as an observation image. On the other hand, the illumination system illuminates the observation target from an oblique direction. Here, when the illumination light specularly reflected by the observation target enters the observation system, some strong light may cause halation, which may hinder detailed image inspection of the inner surface of the tube. However, if the exit surface is configured like the omnidirectional illumination optical member of the embodiment of the present invention, oblique illumination can be performed on the observation target over the entire periphery of the side, so that the illumination light that is specularly reflected by the observation target Does not enter the observation system, an observation image with little halation can be obtained, and a detailed image inspection of the inner surface of the tube is facilitated.

  In addition, if the omnidirectional illumination optical member of the embodiment of the present invention is used, unlike the configuration using the optical member filled with the scattering material, the scattered light emitted in the direction other than the observation target is Since it does not occur, the light use efficiency is increased accordingly.

For this reason, according to the omnidirectional illumination optical member of the embodiment of the present invention, in the endoscope that observes the entire side of the tubular observation object from the illuminating light supply means arranged eccentrically, Illumination light can be used to illuminate the observation target over the entire side of the side with almost uniform light intensity, high light utilization efficiency and bright illumination, and specular reflection during tube observation Therefore, it is possible to irradiate illumination light that is less likely to cause halation and is easy to observe with an observation system.
In the omnidirectional illumination optical member of the embodiment of the present invention, the illumination light supply means eccentrically arranged at the endoscope distal end may be a light guide member such as a light guide that guides light from the illumination light source. Alternatively, an illumination light source such as an LED may be used.

Moreover, in the all-around illumination optical member of embodiment of this invention, Preferably, the inside of the said cylindrical part with an opening provided in the said internal peripheral surface of the said cylindrical part with an opening, the said front-end | tip part, and the said rear-end part. And a first reflecting portion that reflects light incident on the inner peripheral surface, the tip portion, and the rear end portion.
In this way, the incident light from the illumination light supply means is made to deviate from the direction of the imaginary line passing through the respective axes of the cylindrical shape of the inner peripheral surface and the cylindrical shape of the outer peripheral surface of the cylindrical portion with the opening. When the inside of the attached cylindrical portion is supplied, by repeating the reflection action of the first reflecting portion and the total reflection surface respectively formed over the entire circumference of the outer peripheral surface of the attached cylindrical portion, It is possible to illuminate the observation target toward the entire periphery on the side while diffusing light over the entire periphery of the outer peripheral surface. Moreover, the light from the illumination light supply means eccentrically arranged at the endoscope front end portion can be directed to the outer peripheral surface without leaking from the inner peripheral surface, the front end portion, and the rear end portion of the cylindrical portion with the opening. . As a result, it is possible to perform high-efficiency and bright illumination with little loss of the amount of illumination light toward the entire periphery on the side of the distal end portion of the endoscope.

Moreover, in the omnidirectional illumination optical member of the embodiment of the present invention, preferably, the light from the illumination light supply means is transmitted into the cylindrical shape of the inner peripheral surface and the cylindrical shape of the outer peripheral surface of the columnar portion with the opening. An illumination light guide unit is provided to be supplied to the inside of the cylindrical part with the opening so as to deviate from the direction of the imaginary line passing through each axis.
In this way, the light supplied to the inside of the cylindrical portion with the opening is made obtuse to the incident angle of the light with respect to the inner peripheral surface and the outer peripheral surface in the vicinity of the illumination light supply position from the illumination light supply means. While suppressing the ratio of light emitted from the region to the outside of the cylindrical portion with the opening, the light can be deflected in the direction in which the light propagates over the entire periphery of the cylindrical portion with the opening.

In the omnidirectional illumination optical member according to the embodiment of the present invention, preferably, the illumination light guide part includes a region facing the emission part of the illumination light supply means at the tip of the cylindrical part with an opening. Light that is formed in a predetermined region and is supplied to the inside of the cylindrical portion with the opening by the illumination light supply means and travels in the direction toward the tip of the cylindrical portion with the opening is transmitted to the inner peripheral surface of the cylindrical portion with the opening. It consists of a 2nd reflection part which reflects in the direction which deviates from the direction of the virtual line which passes through each axis | shaft of cylindrical shape and the cylindrical shape of the said outer peripheral surface.
Alternatively, in the omnidirectional illumination optical member according to the embodiment of the present invention, preferably, one of the front end and the rear end of the cylindrical portion with the opening is between the front end and the rear end. A spiral surface formed so that the wall thickness varies along the circumferential direction, and a step is formed on the spiral surface that intersects the spiral surface and exits from the exit portion of the illumination light supply means. A step-forming surface for introducing light in a direction deviating from the direction of the imaginary line passing through the cylindrical shape of the inner peripheral surface of the cylindrical portion and the cylindrical shape of the outer peripheral surface and guiding the light into the cylindrical portion with the opening. And the illumination light guide part is formed of the step forming surface.
Alternatively, in the omnidirectional illumination optical member according to the embodiment of the present invention, preferably, one of the front end and the rear end of the cylindrical portion with the opening is between the front end and the rear end. A spiral surface formed so that the wall thickness varies along the circumferential direction, and a step is formed on the spiral surface crossing the spiral surface, and the light emitted from the emission part of the illumination light supply means is incident thereon. A step forming surface that guides the inside of the cylindrical portion with the opening, and the illumination light guide portion transmits the light emitted from the emission portion of the illumination light supply means to the inner peripheral surface of the cylindrical portion with the opening. It consists of the 3rd reflection part which reflects in the direction which deviates from the direction of the virtual line which passes through each axis | shaft of cylindrical shape and the cylindrical shape of the said outer peripheral surface, and injects into the said level | step difference formation surface.

  If it carries out like these, the incident angle of the light with respect to the inner peripheral surface and outer peripheral surface of the illumination light supply position vicinity area | region from the illumination light supply means by the light supplied by the illumination light guide part inside the cylindrical part with an opening With the obtuse angle, the effect of deflecting light in the direction of propagating light over the entire circumference of the cylindrical portion with the opening can be realized while suppressing the ratio of the light emitted from the region on the outer peripheral surface to the outside of the cylindrical portion with the opening.

Moreover, in the omnidirectional illumination optical member of embodiment of this invention, Preferably, it has a cylindrical sapphire cover glass which covers further the perimeter of the said outer peripheral surface of the said cylindrical part with an opening.
In a normal endoscope that observes the front, the side surface of the endoscope tip is covered with a metal barrel, but in an endoscope that observes the entire periphery of the side, a metal barrel is used. If you cover the side with, you can not observe. However, when the cylindrical part with an opening is provided at the distal end of the endoscope in a bare state, the cylindrical part with the opening comes into contact with the observation target, and moisture adheres to the outer peripheral surface of the cylindrical part with the opening. There is a possibility that the total reflection condition will change and adversely affect the illumination over the entire side.
However, if the entire periphery of the outer peripheral surface of the cylindrical portion with the opening is covered with a cylindrical cover glass as in the omnidirectional illumination optical member of the embodiment of the present invention, the outer peripheral surface of the cylindrical portion with the opening is formed. An air layer can be secured between the total reflection surface and the cylindrical cover glass, and the total reflection conditions on the total reflection surface on the outer peripheral surface of the cylindrical portion with the opening can be maintained.
Further, when performing all-around side observation, the cylindrical cover glass is often in direct contact with an object positioned outside the distal end portion of the endoscope, such as the surface to be observed, and is easily scratched.
However, if the material of the cylindrical cover glass is made of sapphire, like the omnidirectional illumination optical member of the embodiment of the present invention, scratches due to contact with an object located outside the endoscope distal end can be prevented. Can be prevented.

In the omnidirectional illumination optical member of the embodiment of the present invention, it is preferable that the second reflecting portion has a cylindrical shape of the inner peripheral surface and a cylindrical shape of the outer peripheral surface of the columnar portion with the opening. The cross section is composed of a V-shaped surface having two reflecting surfaces inclined in different directions with a virtual line passing through the axis as a boundary.
If it does in this way, the light which entered from the position biased to the inside of the cylindrical part with an opening by a light guide member will be the cylinder of the inner peripheral surface of the cylindrical part with an opening by each reflective surface which constitutes the 2nd reflective part. The reflected light is reflected in two directions deviating from the direction of the imaginary line passing through the respective axes of the cylindrical shape and the outer peripheral surface, and each light reflected by each reflective surface is divided into a uniform amount of light and Propagation is made between the inner peripheral surface and the outer peripheral surface in different directions over the entire circumference, so that the speed of propagating the inside of the cylindrical portion with the opening is increased. Moreover, since the angle which injects into the internal peripheral surface and outer peripheral surface of the cylindrical part with an opening of each light reflected by each reflective surface can be made into an obtuse angle, the light from the light guide member in the cylindrical part with an opening is made. The amount of light emitted outside without being totally reflected by the total reflection surface of the light incident on the outer peripheral surface in the vicinity of the incident position can be suppressed, and as a result, uniform light can be easily propagated over the entire periphery.

In the omnidirectional illumination optical member according to the embodiment of the present invention, it is preferable that the second reflecting portion be inclined in different directions around a virtual axis on the optical axis of the illumination light supply unit. It consists of a pyramid-shaped surface having the above reflecting surfaces.
If it does in this way, it will be made to reflect in three or more directions which deviate from the direction of the imaginary line which passes through the axis of each of the cylindrical shape of the inner peripheral surface of a column part with an opening, and the cylindrical shape of an outer peripheral surface by each reflective surface. While making the incident angle of each light incident on the inner and outer peripheral surfaces of the cylindrical portion obtuse, the entire amount of space between the inner peripheral surface and the outer peripheral surface of the cylindrical portion with the opening is divided into multiple uniform amounts of light. The light can be propagated in different directions over the periphery, and more uniform light can be easily propagated over the entire periphery.

Moreover, in the all-around illumination optical member of embodiment of this invention, Preferably, the said outer peripheral surface of the said cylindrical part with an opening is formed with the convex part by which the cross section was formed in multiple numbers at intervals over the perimeter. And the exit surface is a tapered surface in a convex portion having a trapezoidal cross section.
By doing so, a plurality of deflection surfaces deviating from the orientation of the imaginary line passing through the respective axes of the cylindrical shape of the inner peripheral surface and the cylindrical shape of the outer peripheral surface of the cylindrical portion with the opening due to the respective reflecting surfaces constituting the second reflecting portion. Each tapered surface formed in a trapezoidal convex portion is reflected in the direction and propagates in different directions over the entire circumference between the inner peripheral surface and the outer peripheral surface of the cylindrical portion with an opening Thus, the light can enter and exit at an angle smaller than the critical angle. As a result, uniform light can be emitted over the entire circumference of the outer peripheral surface of the cylindrical portion with the opening.

  Moreover, in the omnidirectional illumination optical member according to the embodiment of the present invention in which the second reflecting portion is composed of a plurality of reflecting surfaces, preferably, each of the above-mentioned individual formed over the entire circumference of the outer peripheral surface of the cylindrical portion with the opening. The exit surface is formed over the entire circumference of the outer peripheral surface of the cylindrical portion with the opening, and the individual output surfaces are cylinders of the inner peripheral surface of the cylindrical portion with the opening on the outer peripheral surface of the cylindrical portion with the opening. The light reflected by the second reflecting portion propagates through the inside of the cylindrical portion with the opening in each half-circumferential region that is divided into two with the virtual line passing through the respective axes of the shape and the cylindrical shape of the outer peripheral surface as a boundary. In each direction, the arrangement interval becomes shorter as the distance from the first incident region of the light reflected by the second reflecting portion increases.

Since a large amount of light is incident on the first incident area of the light reflected by the second reflecting portion on the outer peripheral surface of the cylindrical portion with the opening, the amount of light to be emitted tends to increase. Further, the outer peripheral surface of the cylindrical portion with the opening is light reflected by the second reflecting portion along each direction in which the light reflected by the second reflecting portion propagates through the inside of the cylindrical portion with the opening. As the distance from the first incident region increases, the amount of incident light decreases by the amount of light that has exited from the outer peripheral surface up to that point, and the amount of emitted light tends to decrease accordingly.
However, as in the omnidirectional illumination optical member of the embodiment of the present invention, the arrangement interval of the individual exit surfaces formed over the entire circumference of the outer peripheral surface of the cylindrical portion with the opening is set to the opening on the outer peripheral surface of the cylindrical portion with the opening. The light reflected by the second reflecting portion in each half-circumferential region divided into two with the imaginary line passing through the respective axes of the cylindrical shape of the inner peripheral surface and the cylindrical shape of the outer peripheral surface as a boundary. If the distance from the first incident area of the light reflected by the second reflecting section is reduced along each direction propagating through the inside of the section, it is divided into two with the virtual line as a boundary. In each of the half-circumferential regions, it is possible to suppress the light emission frequency from the region with a large amount of incident light on the outer peripheral surface of the cylindrical portion with the opening and increase the light emission frequency from the region with a small amount of incident light. As a result, the amount of emitted light over each half-circumferential region divided into two with the virtual line as a boundary can be made uniform, and the amount of emitted light over the entire circumference of the outer peripheral surface of the cylindrical portion with openings can be made uniform.

Moreover, in the omnidirectional illumination optical member according to the embodiment of the present invention in which the second reflecting portion is composed of a plurality of reflecting surfaces, preferably, each of the above-mentioned individual formed over the entire circumference of the outer peripheral surface of the cylindrical portion with the opening. The exit surface is divided into two on the outer peripheral surface of the cylindrical portion with the opening, with the virtual line passing through the respective axes of the cylindrical shape of the inner peripheral surface of the cylindrical portion with the opening and the cylindrical shape of the outer peripheral surface as boundaries. In the half-circumferential region, first of the light reflected by the second reflecting portion along each direction in which the light reflected by the second reflecting portion propagates through the inside of the cylindrical portion with the opening The area increases as the distance from the incident region increases.
In this way, in each half-circumferential area divided into two with the imaginary line as a boundary, the amount of light emitted from the region with a large amount of incident light on the outer peripheral surface of the cylindrical portion with an opening is suppressed, and the amount of light emitted from a region with a small amount of incident light Can be increased. As a result, the amount of emitted light over each half-circumferential region divided into two with the virtual line as a boundary can be made uniform, and the amount of emitted light over the entire circumference of the outer peripheral surface of the cylindrical portion with openings can be made uniform.

  In the omnidirectional illumination optical member according to the embodiment of the present invention, preferably, the second reflecting portion is supplied to the inside of the cylindrical portion with the opening by the illumination light supply means, and the cylindrical portion with the opening is provided. The light traveling in the distal direction is directed to one of two directions with a virtual line passing through the respective axes of the cylindrical shape of the inner peripheral surface and the cylindrical shape of the outer peripheral surface of the columnar portion with the opening as a boundary. The outer peripheral surface of the cylindrical portion with the opening is formed of a plurality of inclined surfaces having different inclination angles with respect to the total reflection surface, which are formed in the same direction at intervals over the entire periphery. The cross section has convex portions having a substantially triangular shape, and the emission surface is an inclined surface having a large inclination angle with respect to the total reflection surface among the two inclined surfaces in the convex portions having a substantially triangular cross section.

  Like the omnidirectional illumination optical member of the embodiment of the present invention, the second reflecting portion is supplied to the inside of the cylindrical portion with the opening by the illumination light supply means, and the light traveling in the tip direction of the cylindrical portion with the opening is opened. It is composed of a single reflecting surface that reflects in any one of two directions with a virtual line passing through the axis of the inner peripheral surface of the attached cylindrical portion and the cylindrical shape of the outer peripheral surface as a boundary. For example, it is reflected in one direction deviating from the direction of the imaginary line passing through the respective axes of the cylindrical shape of the inner peripheral surface and the cylindrical shape of the outer peripheral surface of the cylindrical portion with the opening by one reflecting surface constituting the second reflecting portion. Because the angle at which light is incident on the inner peripheral surface and outer peripheral surface of the cylindrical portion with an opening can be made obtuse, the incident light enters the outer peripheral surface in the vicinity of the incident position of light from the light guide member in the cylindrical portion with an opening. The amount of light emitted to the outside without being totally reflected by the total reflection surface It can, as a result, it is easy to propagate even light over the entire circumference.

  In addition, as in the omnidirectional illumination optical member of the embodiment of the present invention, the outer peripheral surface of the cylindrical portion with an opening is formed in plural in the same direction at intervals over the entire periphery, and the inclination angles with respect to the total reflection surface are different. The cross section having one inclined surface is configured to have a substantially triangular convex portion, and the output surface is configured by an inclined surface having a large inclination angle with respect to the total reflection surface, of the two inclined surfaces in the convex portion having a substantially triangular cross section. Then, it is reflected in one direction deviating from the direction of the imaginary line passing through the respective axes of the cylindrical shape of the inner peripheral surface and the cylindrical shape of the outer peripheral surface of the cylindrical portion with the opening by one reflecting surface constituting the second reflecting portion. The light that propagates in one direction over the entire circumference between the inner and outer peripheral surfaces of the cylindrical portion with an opening is an inclined surface having a large inclination angle with respect to the total reflection surface, and an angle smaller than the critical angle. Can enter and exit

  In the omnidirectional illumination optical member according to the embodiment of the present invention in which the second reflecting portion is formed of a single reflecting surface, preferably, each of the above-described individual formed over the entire circumference of the outer peripheral surface of the cylindrical portion with the opening. The exit surface is a region where light reflected by the second reflecting portion is first incident along a direction in which the light reflected by the second reflecting portion propagates inside the cylindrical portion with the opening. As the distance from the distance increases, the arrangement interval becomes shorter.

Since a large amount of light is incident on the first incident area of the light reflected by the second reflecting portion on the outer peripheral surface of the cylindrical portion with the opening, the amount of light to be emitted tends to increase. Further, the outer peripheral surface of the cylindrical portion with the opening is the first of the light reflected by the second reflecting portion along the direction in which the light reflected by the second reflecting portion propagates through the inside of the cylindrical portion with the opening. As the distance from the incident area increases, the amount of incident light decreases by the amount of light that has exited from the outer peripheral surface, and the amount of emitted light tends to decrease accordingly.
However, like the omnidirectional illumination optical member of the embodiment of the present invention, the light that is reflected by the second reflecting portion on the arrangement interval of the individual emission surfaces formed over the entire circumference of the outer peripheral surface of the cylindrical portion with the opening. As the distance from the first incident area of the light reflected by the second reflecting portion decreases along the direction of propagation through the inside of the cylindrical portion with the opening, the outer periphery of the cylindrical portion with the opening It is possible to suppress the light emission frequency from the region with a large amount of incident light on the surface and increase the light emission frequency from a region with a small amount of incident light. As a result, the amount of emitted light can be made uniform over the entire circumference of the outer peripheral surface of the cylindrical portion with the opening.

In the omnidirectional illumination optical member according to the embodiment of the present invention in which the second reflecting portion is formed of a single reflecting surface, preferably, each of the above-described individual formed over the entire circumference of the outer peripheral surface of the cylindrical portion with the opening. The exit surface is a region where light reflected by the second reflecting portion is first incident along a direction in which the light reflected by the second reflecting portion propagates inside the cylindrical portion with the opening. The area increases as you move away from.
If it does in this way, the emitted light quantity from the area | region with much incident light quantity in the outer peripheral surface of a cylindrical part with an opening can be suppressed, and the emitted light quantity from the area | region with small incident light quantity can be increased. As a result, the amount of emitted light can be made uniform over the entire circumference of the outer peripheral surface of the cylindrical portion with the opening.

In the omnidirectional illumination optical member of the embodiment of the present invention, in which the illumination light guide portion includes a step forming surface or a third reflecting portion that is incident on the step forming surface, preferably, the outer periphery of the cylindrical portion with the opening The surface has a plurality of inclined surfaces with two inclined surfaces with different inclination angles with respect to the total reflection surface, which are formed in the same direction at intervals over the entire circumference, and have a substantially triangular projection, and the emission surface is Of the two inclined surfaces of the convex portion having a substantially triangular cross section, the inclined surface has a large inclination angle with respect to the total reflection surface.
If it does in this way, it will enter from a level | step difference formation surface, and is supplied to one direction which deviates from the direction of the imaginary line which passes through each axis | shaft of the cylindrical shape of the internal peripheral surface of a cylindrical part with an opening, and the cylindrical shape of an outer peripheral surface, and opening. The light propagating in one direction over the entire circumference between the inner and outer peripheral surfaces of the attached cylindrical part is incident on an inclined surface having a large inclination angle with respect to the total reflection surface at an angle smaller than the critical angle. Can be emitted.

In the omnidirectional illumination optical member of the embodiment of the present invention, in which the illumination light guide portion includes a step forming surface or a third reflecting portion that is incident on the step forming surface, preferably, the outer periphery of the cylindrical portion with the opening Each of the exit surfaces formed over the entire circumference of the surface is configured such that the light incident from the step forming surface travels along the direction in which the light incident from the step forming surface propagates inside the cylindrical portion with the opening. As the distance from the first incident region in the cylindrical portion with the opening increases, the arrangement interval becomes shorter.
In this way, it is possible to suppress the light emission frequency from the region with a large amount of incident light on the outer peripheral surface of the cylindrical portion with the opening, and to increase the light emission frequency from a region with a small amount of incident light. As a result, the amount of emitted light can be made uniform over the entire circumference of the outer peripheral surface of the cylindrical portion with the opening.

In the omnidirectional illumination optical member of the embodiment of the present invention, in which the illumination light guide portion includes a step forming surface or a third reflecting portion that is incident on the step forming surface, preferably, the outer periphery of the cylindrical portion with the opening Each of the exit surfaces formed over the entire circumference of the surface is configured such that the light incident from the step forming surface travels along the direction in which the light incident from the step forming surface propagates inside the cylindrical portion with the opening. The area increases as the distance from the first incident region inside the cylindrical portion with the opening increases.
If it does in this way, the emitted light quantity from the area | region with much incident light quantity in the outer peripheral surface of a cylindrical part with an opening can be suppressed, and the emitted light quantity from the area | region with small incident light quantity can be increased. As a result, the amount of emitted light can be made uniform over the entire circumference of the outer peripheral surface of the cylindrical portion with the opening.

  If the omnidirectional illumination optical system for an endoscope is configured to include illumination light supply means and the omnidirectional illumination optical member of any of the embodiments of the present invention described above, the above-described implementation of the present invention will be described. An omnidirectional illumination optical system for an endoscope having an effect of the omnidirectional illumination optical member of the form can be realized.

  In addition, the all-around observation endoscope has a part of lenses in the opening of the all-around illumination optical member and the cylindrical portion with the opening of any of the embodiments of the present invention described above, and covers the entire periphery of the side. If an endoscope is provided with an objective optical system for observing an observation target, an all-around observation endoscope having the effect of the all-around illumination optical member of the above-described embodiment of the present invention can be realized. .

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is an explanatory diagram illustrating an example of a schematic configuration of an all-around illumination optical system for an endoscope and an all-around observation endoscope provided with the all-around illumination optical member according to any of the embodiments of the present invention.
1 has an observation optical system 4 for observing an observation object over the entire periphery of the side, and an omnidirectional illumination optical system 20 for illuminating the observation object over the entire periphery of the side. ing.
The observation optical system 4 includes an objective optical system 2 and an imaging optical system 3.
In the example of FIG. 1, the objective optical system 2 includes, in order from the object side, a cylindrical sapphire cover glass 2a, lenses 2b, lenses 2c and 2d, cover glass 2e, and the like. The imaging optical system 3 includes an imaging optical system including a cover glass 3a and lenses 3b and 3c, an imaging element 3d, and the like. The lens 2b deflects in the longitudinal direction of the endoscope by reflecting twice the light around the entire side that has entered through the cover glass 2a.
The omnidirectional illumination optical system 20 includes, in order from the light source side, a light source (not shown), a light guide 21, a cover glass 22, and the omnidirectional illumination optical member 10 of any of the embodiments of the present invention. In FIG. 1, reference numeral 15 denotes a light guide member such as a rod rod that guides light from the light guide 21 to the inside of a cylindrical part 11 with an opening, which will be described later, which forms one member of the all-around illumination optical member 10, and 18 The housing 19 is a cylindrical sapphire cover glass that forms one member of the all-around illumination optical member 10. In the example of FIG. 1, the housing 18 holds a cylindrical sapphire cover glass 2a at the outer periphery of the tip, a lens 2b at the tip, and lenses 2c and 2d and a cover glass 2e inside, as well as the lenses 2c and 2d. The cylindrical portion 11 with an opening and the light guide member 15 are held at the outer periphery of the portion that holds the light. Further, the light guide 21 and the light guide member 15 in the example of FIG. 1 constitute illumination light supply means in the present invention, and are eccentrically arranged at the distal end portion of the endoscope. The light guide member 15 is a light guide in order to fill a gap from the cylindrical portion 11 with an opening provided in the housing 18 to the end surface on the light guide 22 side of the housing 18 in an adapter attached to the distal end portion of the endoscope including the light guide 21. It arrange | positions between 21 and the cylinder part 11 with an opening.

With such a configuration, the omnidirectional observation endoscope 1 illuminates the observation object over the entire periphery of the side via the omnidirectional illumination optical system 20, and the side of the endoscope 1 for the omnidirectional observation via the observation optical system 4. Acquire an image of the observation object over the entire circumference.
More specifically, light from an illumination light source (not shown) enters the light guide member 15 through the light guide 21 and the cover glass 22, and is guided to the inside of the cylindrical portion 11 with the opening through the light guide member 15. . The light guided to the inside of the columnar part 11 with the opening is emitted from the outer peripheral surface of the columnar part 11 with the opening, passes through the cover glass 19, and illuminates the observation target over the entire side from the oblique direction.
The light from the observation object over the entire circumference on the side illuminated from the oblique direction by the all-around illumination optical system 20 enters the lens 2b through the cover glass 2a. The light incident on the lens 2b is reflected twice through the incident lens 2b to be deflected and emitted in the longitudinal direction of the endoscope, and enters the cover glass 3a through the lenses 2c and 2d and the cover glass 2e. . The light incident on the cover glass 3a forms an image on the image pickup surface of the image pickup device 3 through the lenses 3b and 3c. The image pickup device 3 picks up an image of an observation target that covers the entire periphery of the formed side.
In the endoscope of FIG. 1, the lens 2b may be configured so that an image from a front observation object can be observed in the central region. In that case, an image of the front observation object is obtained at the center through the imaging optical system 3, and an image of the observation object is obtained all around the side around the image.

First Embodiment FIG. 2 is a view showing the configuration of an omnidirectional illumination optical member according to the first embodiment of the present invention. FIG. 2 (a) is a diagram of a member located inside a cylindrical cover glass in the omnidirectional illumination optical member. FIG. 5B is a perspective view showing an appearance, and FIG. 5B is a plan view of the omnidirectional illumination optical member viewed from the light incident side. FIG. 3 is an explanatory view showing both the structure of the member located inside the cylindrical cover glass in the all-around illumination optical member of FIG. 2 and the action of diffusing and illuminating the light from the illumination light supply means to the entire periphery. (A) is a plan view seen from the light incident side, (b) is an explanatory view of the main part seen from the lower side. FIG. 4 is an explanatory view showing the function of the exit surface provided in the all-around illumination optical member shown in FIG. 3, and (a) schematically shows the traveling direction of light incident on the exit surface in a direction that can be totally reflected by the total reflection surface. (B) is a diagram schematically showing the traveling direction of light that is emitted from the emission surface of the all-around illumination optical member toward the observation target on the entire side and is specularly reflected by the observation target. ) Is a comparative example of (b), the progress of the light that is specularly reflected by the observation target in the omnidirectional illumination optical member whose outer peripheral surface is configured so that the illumination light is emitted almost perpendicular to the total reflection surface. It is a figure which shows a direction.

As shown in FIGS. 2 and 3, the omnidirectional illumination optical member 10 of the first embodiment includes a cylindrical portion 11 with an opening, a first reflection portion 12, a total reflection surface 13, an exit surface 14 a, Two reflecting portions 16 and a cylindrical cover glass 19. 2 and 3, reference numeral 15 denotes a light guide member such as a rod bar that guides light from the light guide 22 shown in FIG.
The cylindrical portion 11 with an opening is made of a transparent medium, and has an inner peripheral surface 11a, an outer peripheral surface 11b, a front end portion 11c, and a rear end portion 11d.
The inner peripheral surface 11a and the outer peripheral surface 11b are each formed in a cylindrical shape at positions that are coaxial or non-coaxial with each other. 2 and 3, the inner peripheral surface 11a and the outer peripheral surface 11b are formed at positions that are not coaxial with each other, and the cylindrical inner opening that forms the inner peripheral surface 11a forms the outer peripheral surface 11b. It is eccentric with respect to the cylindrical shape.
The front end portion 11c and the rear end portion 11d are formed in an annular shape that comes into contact with the inner peripheral surface 11a and the outer peripheral surface 11b, respectively.
Further, the cylindrical inner opening forming the inner peripheral surface 11a in the columnar portion 11 with the opening has a size capable of arranging a part of the lenses of the objective optical system as shown in FIG.
The 1st reflection part 12 is comprised by the reflective film with which the inner peripheral surface 11a, the front-end | tip part 11c, and the rear-end part 11d of the cylindrical part 11 with an opening were equipped. In addition, the 1st reflection part 12 is a reflection surface which contact | connects the inner peripheral surface 11a of the cylinder part 11 with an opening, the front-end | tip part 11c, and the rear-end part 11d in the housing 18 which accommodates the cylinder part 11 with an opening shown in FIG. It may be configured. And the 1st reflection part 12 reflects the light which entered the internal peripheral surface 11a, the front-end | tip part 11c, and the rear-end part 11d through the inside of the cylinder part 11 with an opening.

The total reflection surface 13 and the emission surface 14a are alternately formed over the entire periphery of the outer peripheral surface 11b of the cylindrical portion 11 with an opening.
Specifically, the outer peripheral surface 11b has a plurality of convex portions 14 each having a trapezoidal cross section formed at intervals over the entire periphery.
The exit surface 14a is formed by a tapered surface of the convex portion 14 having a trapezoidal cross section. For example, as shown in FIG. 4A, the incident surface 14a can be totally reflected when incident on the total reflection surface 13. (In FIG. 4A, a part of the light incident in the direction a) is emitted in an oblique direction with respect to the total reflection surface 13 to the outside of the cylindrical portion 11 with an opening. For convenience, FIG. 4A shows light incident on the right tapered surface 14a in FIG. 4A while propagating through the inside of the cylindrical portion 11 with an opening in the direction of arrow A in FIG. 4, the light incident on the left tapered surface 14 a in FIG. 4 while propagating through the inside of the cylindrical portion 11 with the opening in the direction of the arrow B in FIG. 3, the left tapered surface 14 a in FIG. In the same manner as described above, the light is emitted obliquely with respect to the total reflection surface 13 to the outside of the cylindrical portion 11 with the opening. In addition, as shown in FIG. 4B, “oblique direction with respect to the total reflection surface” here is emitted from the all-around illumination optical member 10 toward the tubular observation target, and the inner periphery of the observation target. This means a direction inclined with respect to the total reflection surface 13 to such an extent that the light specularly reflected by the surface deviates from the objective optical system 2 of the observation optical system 4 shown in FIG.
As shown in FIG. 2B, the cylindrical sapphire cover glass 19 is configured to cover the entire periphery of the outer peripheral surface 11b of the columnar part 11 with an opening, and on the outer peripheral surface of the columnar part 11 with an opening. An air layer is secured between the formed total reflection surface.
The light guide member 15 has a cylindrical region of the inner peripheral surface 11a and a cylindrical shape of the outer peripheral surface 11b of the cylindrical portion 11 with the openings O1, O2 in a partial region at the rear end portion 11d of the cylindrical portion 11 with the opening. Is provided such that the optical axis O3 is in contact with the imaginary line L1 passing through and the outer periphery is covered with a reflecting member.
The second reflecting portion 16 corresponds to the illumination light guiding portion in the present invention, and as shown in FIGS. 3 (a) and 3 (b), the light guide member 15 at the tip portion 11c of the cylindrical portion 11 with an opening. A cross section having two reflecting surfaces 16a and 16b formed in a predetermined region including a region facing the emission surface and inclined in different directions (left and right directions in FIG. 3A) with a virtual line L1 as a boundary. It consists of a letter-shaped surface.
The second reflecting portion 16 is guided to the inside of the cylindrical portion 11 with an opening by the light guide member 15 and proceeds in the distal direction of the cylindrical portion 11 with the opening, and is incident on the two reflecting surfaces 16a and 16b, respectively. Reflected in two directions deviating from the direction of the virtual line L1.

Illumination of the observation target over the entire circumference on the side using the all-around illumination optical member 10 of the first embodiment configured as described above is performed as follows.
The light from the light guide 21 shown in FIG. 1 passes through the light guide member 15 and is guided to the inside of the cylindrical portion 11 with an opening. The light that has been guided to the inside of the cylindrical portion 11 with an opening and traveled in the direction of the tip of the cylindrical portion 11 with the opening is deviated from the direction of the virtual line L1 by the two reflecting surfaces 16a and 16b (see FIG. 3 (a)). ) In the left-right direction). The respective lights reflected in the two directions deviating from the direction of the virtual line L1 by the reflecting surfaces 16a and 16b are repeatedly reflected between the outer peripheral surface 11b of the cylindrical portion 11 with the opening and the inner peripheral surface 11a. Propagating the inside of the cylindrical portion 11 with an opening in a direction away from the first incident region of the light reflected by the second reflecting portion 16 (in the example of FIG. 3, the direction of the arrow A and the direction of the arrow B). go. In this process, light incident on each total reflection surface 13 formed on the outer peripheral surface 11b at an angle smaller than the critical angle is emitted from the total reflection surface 13 to the outside of the cylindrical portion 11 with the opening, and is larger than the critical angle. Light incident at an angle is reflected by the total reflection surface 13. In addition, a part of the incident light in a direction that can be totally reflected when entering the total reflection surface 13 on each of the emission surfaces 14a formed on the outer peripheral surface 11b from the emission surface 14a. The light is emitted obliquely with respect to the total reflection surface 13.
As a result, most of the illumination light is emitted in an oblique direction with respect to the outer peripheral surface 11b from the side of the cylindrical portion 11 with the opening to the entire periphery. Most of the illumination light emitted from the cylindrical portion 11 with the opening illuminates the observation target from an oblique direction through the cylindrical sapphire cover glass 19.

  According to the omnidirectional illumination optical member 10 of the first embodiment, the inner peripheral surface 11a, the outer peripheral surface 11b, and the inner peripheral surface 11a, which are made of a transparent medium and are respectively formed in a cylindrical shape at coaxial or non-coaxial positions. Since it has the cylindrical part 11 with an opening which has the front-end | tip part 11c and the rear-end part 11d which were each formed in the cyclic | annular form which touches the outer peripheral surface 11b, the illumination light supply means eccentrically arranged at the endoscope front-end | tip part shown in FIG. By propagating the light from the light guide 21 and the light guide member 15 through the inside of the cylindrical portion 11 with the opening, it is possible to illuminate the entire periphery on the side of the distal end portion of the endoscope.

  Further, according to the omnidirectional illumination optical member 10 of the first embodiment, the inner circumferential surface 11a, the front end portion 11c, and the rear end portion 11d of the columnar portion 11 with an opening pass through the inside of the columnar portion 11 with an opening. Since the first reflecting portion 12 that reflects the light incident on the inner peripheral surface 11a, the front end portion 11c, and the rear end portion 11d is provided, the illumination light supply means eccentrically arranged at the front end portion of the endoscope shown in FIG. Light from the light guide 21 and the light guide member 15 can be directed to the outer peripheral surface 11b without leaking from the inner peripheral surface 11a, the front end portion 11c, and the rear end portion 11d of the cylindrical portion 11 with the opening. As a result, it is possible to perform high-efficiency and bright illumination with little loss of the amount of illumination light toward the entire periphery on the side of the distal end portion of the endoscope.

Moreover, according to the all-around illumination optical member 10 of 1st Embodiment, when it injects into the total reflection surface 13 and the total reflection surface 13 alternately formed over the perimeter of the outer peripheral surface 11b of the cylindrical part 11 with an opening. 1 has an exit surface 14a for emitting a part of the light incident in a direction that can be totally reflected to the outside of the cylindrical portion 11 with the opening, so that the illumination light is eccentrically arranged at the distal end portion of the endoscope shown in FIG. Even if light from the supply means (light guide 21 and light guide member 15) is incident on the inside of the cylindrical portion 11 with an opening, the reflection action of the total reflection surface 13 and the first reflection portion 12 is repeated. Thus, it is possible to illuminate the observation target toward the entire periphery on the side while diffusing light over the entire periphery of the outer peripheral surface 11b of the cylindrical portion 11 with the opening.
Further, since the total reflection surface 13 and the emission surface 14a are alternately formed over the entire circumference of the outer peripheral surface 11b of the cylindrical portion 11 with the opening, the light from the light guide 21 arranged eccentrically at the distal end portion of the endoscope shown in FIG. A large amount of light is not emitted from the outer peripheral surface 11b in the vicinity of the incident position, and a certain amount of light is easily emitted over the entire periphery of the outer peripheral surface 11b of the cylindrical portion 11 with an opening. As a result, illumination with a uniform amount of light can be performed toward the entire periphery on the side of the distal end portion of the endoscope.
In addition, when the exit surface 14a is incident on the total reflection surface 13, a part of the incident light is emitted to the outside of the cylindrical portion 11 with an opening in an oblique direction with respect to the total reflection surface. As shown in FIG. 4B, the light emitted from the emission surface 14a is obliquely applied to the observation target over the entire side, and the specular reflection light from the observation target is obtained. Is easily removed from the entrance end of the side observation system of the endoscope (for example, the cylindrical sapphire cover glass 2a of the objective optical system 2 constituting the observation optical system 4 in the endoscope of FIG. 1). As a result, specular reflection light during in-tube observation can be reduced, and illumination light that is less likely to cause halation and can be easily observed in the observation system can be irradiated.
As shown in FIG. 1, the omnidirectional illumination optical member according to each embodiment of the present invention is premised on being applied to an endoscope that observes an observation target over the entire periphery on the side. . In an endoscope that observes an observation object that covers the entire periphery of the side, the observation system enters light from the observation object that covers the entire periphery of the side, and forms an image as an observation image. On the other hand, the illumination system illuminates the observation target from an oblique direction. Here, as shown in FIG. 4 (c) as a comparative example, when the outer peripheral surface is configured so that the illumination light specularly reflected by the observation target is incident on the observation system, some strong light causes halation, and the inside of the tube There is a risk of hindering detailed image inspection of the surface. However, if the exit surface 13 is configured like the all-around illumination optical member 10 of the first embodiment, oblique observation can be performed on the observation target over the entire periphery on the side, and therefore, as shown in FIG. As described above, the illumination light specularly reflected by the observation target does not enter the observation system, and an observation image with less halation can be obtained, which facilitates detailed image inspection of the inner surface of the tube.

  Moreover, according to the all-around illumination optical member 10 of 1st Embodiment, the predetermined | prescribed including the area | region which opposes the output part (output surface of the light guide member 15) of the illumination light supply means in the front-end | tip part 11c of the cylindrical part 11 with an opening. A second light that is guided to the inside of the cylindrical part 11 with the opening by the light guide member 15 and is incident on the tip of the cylindrical part 11 with the opening formed in the region is reflected in a direction deviating from the direction of the virtual line L1. Therefore, the light guided to the inside of the cylindrical portion 11 with the opening by the light guide member 15 is transmitted to the inner peripheral surface 11a and the outer peripheral surface 11b in the vicinity of the light guide position from the light guide member 15. Can be deflected in the direction in which the light is propagated over the entire circumference of the cylindrical portion 11 with the opening while suppressing the ratio of the light emitted from the region on the outer peripheral surface 11b to the outside of the cylindrical portion 11 with the opening.

  Moreover, according to the omnidirectional illumination optical member 10 of 1st Embodiment, the cross section which has the two reflective surfaces 16a and 16b which incline the 2nd reflection part 16 in a different direction respectively on the virtual line L1 as a boundary is V. Since it is configured with a letter-shaped surface, light incident from a position biased into the cylindrical portion 11 with the opening by the light guide member 15 is virtually reflected by the respective reflecting surfaces 16 a and 16 b constituting the second reflecting portion 16. Each light reflected in two directions deviating from the direction of the line L1 and reflected by the respective reflecting surfaces 16a and 16b is divided into a uniform amount of light, and is formed between the inner peripheral surface 11a and the outer peripheral surface 11b of the cylindrical portion with an opening. Since it propagates in different directions over the entire circumference, the speed of propagation through the inside of the cylindrical portion 11 with an opening becomes faster. Moreover, since the angle which injects into the internal peripheral surface 11a and the outer peripheral surface 11b of the cylindrical part 11 with an opening of each light reflected by each reflective surface 16a, 16b can be made into an obtuse angle, in the cylindrical part 11 with an opening, The amount of light emitted to the outside without being totally reflected by the total reflection surface 13 of the light incident on the outer peripheral surface 11b in the vicinity of the incident position of the light from the light guide member 15 can be suppressed, and as a result, uniform light over the entire circumference. Can be easily propagated.

  Therefore, according to the omnidirectional illumination optical member 10 of the first embodiment, the light guide arranged eccentrically as shown in FIG. 1 in the endoscope that observes the entire side of the tubular observation object. Illumination light from 21 can be used to illuminate the observation object over the entire side of the side with almost uniform light intensity, high light utilization efficiency, and bright illumination. Specular reflection light can be reduced, and it is possible to irradiate illumination light that is less likely to cause halation and is easy to observe in an observation system.

  Moreover, according to the omnidirectional illumination optical member 10 of the first embodiment, the cylindrical cover glass 19 covers the entire periphery of the outer peripheral surface 11b of the columnar part 11 with the opening. 11 can contact, and it can prevent that a water | moisture content adheres to the outer peripheral surface 11b of the cylinder part 11 with an opening. As a result, an air layer can be secured between the total reflection surface 13 formed on the outer peripheral surface 11b of the cylindrical portion 11 with the opening and the cylindrical cover glass 19, and the total reflection surface on the outer peripheral surface 11b of the cylindrical portion 11 with the opening. The total reflection condition at 13 can be maintained. Further, since the material of the cylindrical cover glass 19 is made of sapphire, it is possible to prevent the occurrence of scratches due to contact with an object located outside the endoscope distal end.

Comparative Example FIG. 5 shows the structure of the member located inside the cylindrical sapphire cover glass in the all-around illumination optical member according to the comparative example of the first embodiment and diffuses the light from the illumination light supply means to the entire periphery. It is explanatory drawing which shows the effect | action which illuminates together, (a) is the top view seen from the incident side of light, (b) is principal part explanatory drawing seen from the side. In addition, about the structure similar to 1st Embodiment, the same code | symbol is attached | subjected to a structural member and detailed description is abbreviate | omitted.

  In the omnidirectional illumination optical member 10 ′ of the comparative example, the second reflecting portion 16 ′ is a light guide at the distal end portion 11 c of the cylindrical portion 11 ′ with an opening, as shown in FIGS. 5 (a) and 5 (b). An imaginary line that passes through the respective axes O1 and O2 of the cylindrical shape of the inner peripheral surface 11a and the cylindrical shape of the outer peripheral surface 11b of the cylindrical portion 11 ′ with an opening formed in a predetermined region including a region facing the emission surface of the member 15. Two reflecting surfaces 16a ′ and 16b ′ that are perpendicular to L1 and are inclined in different directions (vertical direction in FIG. 5A) with a virtual line L2 passing through the optical axis O3 of the light guide member 15 as a boundary. The cross section is formed of a V-shaped surface.

In the all-around illumination optical member 10 ′ of the comparative example, the light that is guided to the inside of the cylindrical portion 11 ′ with the opening and proceeds toward the tip of the cylindrical portion 11 ′ with the opening enters the two reflecting surfaces 16a ′ and 16b ′. Thus, the light is reflected in two directions along the direction of the virtual line L1, and is incident on the inner peripheral surface 11a or the outer peripheral surface 11b at a small incident angle. And the light which injected with the small incident angle with respect to the outer peripheral surface 11b is radiate | emitted from the total reflection surface 13 to the exterior of cylindrical part 11 'with an opening. Further, the light incident on the inner peripheral surface 11a is reflected, is incident on the total reflection surface 13 at a small incident angle, and is almost from the total reflection surface 13 to the outside of the cylindrical portion 11 ′ with an opening with respect to the total reflection surface 13. The light is emitted in the vertical direction. Most of the illumination light emitted from the columnar portion 11 ′ with the opening illuminates the observation target in a substantially vertical direction through a cylindrical sapphire cover glass (not shown in FIG. 5).
For this reason, in the all-around illumination optical member 10 ′ of the comparative example, the ratio of light emitted from the vicinity of the light guide position from the light guide member 15 to the outside of the cylindrical portion 11 ′ with the opening on the outer peripheral surface 11b is very high. Therefore, uniform light cannot be illuminated over the entire circumference. Moreover, in the all-around illumination optical member 10 ′, as shown in FIG. 5 (a), most of the illumination light is emitted in a direction substantially perpendicular to the total reflection surface 13, and the observation target is oriented almost perpendicularly. In order to illuminate, as shown in FIG. 4 (c), most of the illumination light that is specularly reflected from the observation object enters the observation system. As a result, some strong light may cause halation, which may hinder detailed image inspection of the inner surface of the tube.

Second Embodiment FIG. 6 shows the structure of a member located inside a cylindrical sapphire cover glass in an all-around illumination optical member according to a second embodiment of the present invention and diffuses light from the illumination light supply means to the entire periphery. (A) is a plan view seen from the light incident side, (b) is a view of the member located inside the cylindrical sapphire cover glass in the all-around illumination optical member It is a perspective view which shows the principal part shape. In addition, about the structure similar to 1st Embodiment, the same code | symbol is attached | subjected to a structural member and detailed description is abbreviate | omitted.

In the omnidirectional illumination optical member 10 ″ of the second embodiment, the four reflecting surfaces 16a in which the second reflecting portions 16 ″ are inclined in four different directions around the virtual axis on the optical axis O3 of the light guide member 15. It is composed of a quadrangular pyramid surface having ", 16b", 16c ", 16d".
Other configurations are substantially the same as those of the omnidirectional illumination optical member 10 of the first embodiment shown in FIGS.

According to the omnidirectional illumination optical member 10 ″ of the second embodiment, the cylindrical shape and the outer peripheral surface of the inner peripheral surface 11a of the columnar portion 11 ″ with the opening are the respective reflecting surfaces 16a ″, 16b ″, 16c ″, 16d ″. Angles of incident light on the inner peripheral surface 11a and the outer peripheral surface 11b of the cylindrical portion 11 ″ with an opening that are reflected in four directions deviating from the direction of the virtual line L1 passing through the respective axes O1 and O2 of the cylindrical shape 11b. Can be propagated in different directions over the entire circumference between the inner peripheral surface 11a and the outer peripheral surface 11b of the cylindrical portion 11 '' with an opening while making the obtuse angle an even amount of light. It becomes easier to propagate more uniform light.
Other functions and effects are substantially the same as those of the omnidirectional illumination optical member 10 of the first embodiment shown in FIGS.
The second reflecting portion 16 ″ may be any pyramid-shaped surface as long as it has a pyramid-shaped surface having three or more reflecting surfaces that are inclined in different directions around the virtual axis on the optical axis O3. For example, you may be comprised by the surface of a triangular pyramid shape, a pentagonal pyramid shape, or a hexagonal pyramid shape.

Third Embodiment FIG. 7 shows the structure of a member located inside a cylindrical sapphire cover glass in an all-around illumination optical member according to a third embodiment of the present invention and diffuses light from the illumination light supply means to the entire periphery. FIG. 4 is an explanatory view showing the action of illuminating together, where (a) is a plan view seen from the light incident side, and (b) is a main part explanatory view seen from the lower side. In addition, about the structure similar to 1st Embodiment, the same code | symbol is attached | subjected to a structural member and detailed description is abbreviate | omitted.

In the all-around illumination optical member 10 ″ ′ of the third embodiment, the second reflecting portion 16 ″ ′ is guided by the light guide member 15 to the inside of the cylindrical portion 11 ″ ′ with the opening, and the cylindrical portion 11 ″ with the opening. The light traveling in the direction of the tip end of 'is two directions with the imaginary lines passing through the respective axes of the cylindrical shape of the inner peripheral surface 11a and the cylindrical shape of the outer peripheral surface 11b of the columnar portion 11''' as shown in FIG. ) In one horizontal direction (left direction in the example of FIG. 7A).
In addition, the outer peripheral surface 11b of the cylindrical portion 11 "'with an opening has a substantially triangular cross section having a plurality of inclined surfaces with different inclination angles with respect to the total reflection surface 13, which are formed in the same direction at intervals over the entire circumference. Convex portion 14 '.
Outgoing surface 14a ′ is formed of an inclined surface having a large inclination angle with respect to total reflection surface 13 among two inclined surfaces of convex portion 14 ′ having a substantially triangular cross section.
Other configurations are substantially the same as those of the omnidirectional illumination optical member 10 of the first embodiment shown in FIGS.

Illumination of the observation object over the entire circumference on the side using the all-around illumination optical member 10 ″ ′ of the third embodiment configured as described above is performed as follows.
The light from the light guide 21 shown in FIG. 1 passes through the light guide member 15 and is guided to the inside of the cylindrical portion 11 ″ ′ with the opening. The light is guided to the inside of the cylindrical portion 11 ″ ′ with the opening and the cylindrical with the opening. The light that travels in the tip direction of the portion 11 ″ ′ enters the cylindrical shape and the outer peripheral surface of the inner peripheral surface 11a of the columnar portion 11 ″ ′ with the opening by one reflecting surface constituting the second reflecting portion 16 ″ ′. 11b is reflected in one direction (left direction in the example of FIG. 7A) deviating from the direction of the imaginary line L1 passing through the respective cylindrical axes O1 and O2 of 11b. The second reflecting portion 16 ″ ′ is formed. The light reflected in one direction deviating from the direction of the imaginary line L1 by one reflecting surface is repeatedly reflected between the outer peripheral surface 11b of the cylindrical portion 11 ″ ′ with the opening and the inner peripheral surface 11a, Of light reflected by one reflecting surface constituting the reflecting portion 16 "' It propagates through the inside of the cylindrical portion 11 ″ ′ with an opening in a direction away from the region (in the example of FIG. 7, the rotation direction in the direction of arrow C). In the process, each total reflection surface 13 formed on the outer peripheral surface 11b. Is incident on the total reflection surface 13 to the outside of the cylindrical portion 11 ′ ′ having an opening, and light incident at an angle larger than the critical angle is reflected by the total reflection surface 13. It is done. In addition, when the light is incident on the total reflection surface 13 on each of the output surfaces 14a ′ formed on the outer peripheral surface 11b, a part of the light incident in a direction that can be totally reflected is emitted from the output surface 14a ′ to a cylinder with an opening. The light is emitted obliquely with respect to the total reflection surface 13 to the outside of the portion 11 ″ ′.
As a result, most of the illumination light is emitted in an oblique direction with respect to the outer peripheral surface 11b from the side of the cylindrical portion 11 "'with the opening to the entire periphery. Most of the illumination light emitted from the cylindrical portion 11"' with the opening. The light illuminates the observation target from an oblique direction through a cylindrical sapphire cover glass (not shown in FIG. 7).

  According to the omnidirectional illumination optical member 10 ″ ′ of the third embodiment, the second reflecting portion 16 ″ ′ is guided by the light guide member 15 to the inside of the cylindrical portion 11 ″ ′ with the opening, and the cylindrical portion with the opening. Since the light traveling in the tip direction of 11 ″ ′ is configured by one reflecting surface that reflects light toward one of the two directions with the virtual line L1 as a boundary, the second reflecting portion 16 ″ ′ The angle at which the light that is reflected in one direction deviating from the direction of the imaginary line L1 is incident on the inner peripheral surface 11a or the outer peripheral surface 11b of the cylindrical portion 11 ″ ′ with an opening can be made an obtuse angle. Therefore, it is possible to suppress the amount of light emitted outside without being totally reflected by the total reflection surface 13 of the light incident on the outer peripheral surface 11b in the vicinity of the incident position of the light from the light guide member 15 in the cylindrical portion 11 ″ ′ with the opening. As a result, it can propagate uniform light over the entire circumference. Kunar.

  Further, according to the omnidirectional illumination optical member 10 ″ ′ of the third embodiment, a plurality of outer peripheral surfaces 11b of the cylindrical portion 11 ″ ′ with openings are formed in a plurality of the same directions at intervals over the entire periphery. The cross section having two inclined surfaces with different inclination angles with respect to 13 has a structure having a convex portion 14 'having a substantially triangular shape, and the exit surface 14a' is defined as the two inclined surfaces in the convex portion 14 'having a substantially triangular shape in cross section. Since it is constituted by an inclined surface having a large inclination angle with respect to the total reflection surface, it is reflected in one direction deviating from the direction of the imaginary line L1 by one reflecting surface constituting the second reflecting portion 16 ″ ′, and a cylinder with an opening The light propagating in one direction over the entire circumference between the inner peripheral surface 11a and the outer peripheral surface 11b of the portion 11 ″ ′ is an inclined surface having a large inclination angle with respect to the total reflection surface 13 and at an angle smaller than the critical angle. Enter and exit Can.

Fourth Embodiment FIG. 8 is a plan view of the configuration of a member located inside a cylindrical sapphire cover glass in an all-around illumination optical member according to a fourth embodiment of the present invention, as viewed from the light incident side. (a) is a diagram showing an example, and (b) is a diagram showing another example. In addition, about the structure similar to 1st Embodiment and 3rd Embodiment, the same code | symbol is attached | subjected to a structural member and detailed description is abbreviate | omitted.

  The omnidirectional illumination optical member 10 ″ ″ in the example of FIG. 8A is a modification of the omnidirectional illumination optical member 10 of the first embodiment shown in FIG. In the all-around illumination optical member 10 "", the individual exit surfaces 14a formed over the entire periphery of the outer peripheral surface 11b of the cylindrical portion 11 "" with the opening are provided with openings on the outer peripheral surface 11b of the cylindrical portion 11 "" with the opening. In each half-circumferential region that is divided into two with a virtual line L1 connecting the respective axes O1 and O2 of the cylindrical shape of the inner peripheral surface 11a and the cylindrical shape of the outer peripheral surface 11b of the columnar part 11 "" as a boundary, the second reflecting part 16 The spacing between the light reflected by the second reflecting portion 16 and the first incident region is increased along the direction in which the light reflected by the second propagating portion 11 "" propagates in the cylindrical portion 11 "" with the opening. Is shorter.

Since a large amount of light is incident on the first incident region of the light reflected by the second reflecting portion 16 on the outer peripheral surface 11b of the cylindrical portion 11 "" with the opening, the amount of emitted light tends to increase. In addition, the outer peripheral surface 11b of the cylindrical portion 11 "" with the opening is in the second direction along each direction in which the light reflected by the second reflecting portion 16 propagates inside the cylindrical portion 11 "" with the opening. As the light reflected by the reflecting portion 16 moves away from the first incident region, the amount of light that has exited from the outer peripheral surface 11b so far becomes smaller, so the amount of light that is emitted tends to decrease accordingly. .
However, according to the omnidirectional illumination optical member 10 "" in the example of FIG. 8 (a), in each half-circumferential region divided into two with the virtual line L1 as a boundary on the outer peripheral surface 11b of the cylindrical portion 11 "" with the opening, It is possible to suppress the light emission frequency from the region with a large amount of incident light on the outer peripheral surface 11b of the cylindrical portion 11 "" with the opening, and to increase the light emission frequency from a region with a small amount of incident light. As a result, on the outer peripheral surface 11b of the cylindrical part 11 "" with the opening, the light quantity of the emitted light over each half-circumferential region divided by the virtual line L1 as a boundary is made uniform, and the outer peripheral surface 11b of the cylindrical part 11 "" with the opening The amount of emitted light over the entire circumference can be made uniform.

  An omnidirectional illumination optical member 10 ″ ″ ′ in the example of FIG. 8B is a modification of the omnidirectional illumination optical member 10 ″ ′ of the third embodiment shown in FIG. In “′”, each of the light exit surfaces 14 a ′ formed over the entire circumference of the outer peripheral surface 11 b of the cylindrical portion 11 ′ ′ with the opening has the light reflected by the second reflecting portion 16 ″ ′. As the distance from the first incident region of the light reflected by the second reflecting portion 16 ″ ′ increases along the direction of propagation through the inside of “”, the arrangement interval becomes shorter.

Since a large amount of light is incident on the first incident region of the light reflected by the second reflecting portion 16 ″ ′ on the outer peripheral surface 11b of the cylindrical portion 11 ″ ″ ′ with the opening, the amount of light to be emitted also increases. In addition, the outer peripheral surface 11b of the cylindrical portion 11 ""'with the opening propagates the light reflected by the second reflecting portion 16 "' in the second cylindrical portion 11""'with the opening. As the distance from the first incident area of the light reflected by the second reflecting portion 16 ″ ′ increases, the incident amount corresponds to the amount of light emitted from the outer peripheral surface 11b. Since the amount of light decreases, the amount of emitted light tends to decrease accordingly.
However, according to the omnidirectional illumination optical member 10 ″ ″ ′ in the example of FIG. 8B, the frequency of light emission from the region with a large amount of incident light on the outer peripheral surface 11b of the cylindrical portion 11 ″ ″ ′ with the opening is suppressed. The frequency of light emission from a region with a small amount of incident light can be increased. As a result, the amount of emitted light can be made uniform over the entire circumference of the outer peripheral surface 11b of the cylindrical portion 11 ""'with the opening.

Fifth Embodiment FIG. 9 is a plan view of the configuration of a member located inside a cylindrical sapphire cover glass in an all-around illumination optical member according to a fifth embodiment of the present invention, as viewed from the light incident side. (a) is a diagram showing an example, and (b) is a diagram showing another example. In addition, about the structure similar to 1st Embodiment and 3rd Embodiment, the same code | symbol is attached | subjected to a structural member and detailed description is abbreviate | omitted.

  The omnidirectional illumination optical member 10 "" "in the example of FIG. 9A is a modification of the omnidirectional illumination optical member 10 of the first embodiment shown in FIG. Then, the individual exit surfaces 14a formed over the entire circumference of the outer peripheral surface 11b of the cylindrical portion 11 "" "with the opening are the cylindrical portions 11" "" with the opening on the outer peripheral surface 11b of the cylindrical portion 11 "" "with the opening. The light reflected by the second reflecting portion 16 in each half-circumferential region divided into two with a virtual line connecting the cylindrical axes of the inner peripheral surface 11a and the cylindrical shape of the outer peripheral surface 11b as a boundary is an open column. The area increases as the distance from the first incident region of the light reflected by the second reflecting portion 16 increases along each direction propagating through the inside of the portion 11 ″ ″ ″.

  According to the omnidirectional illumination optical member 10 "" "in the example of FIG. 9A, in each half-circumferential region divided into two with the virtual line L1 as a boundary, the outer peripheral surface 11b of the cylindrical portion 11" "" with an opening The amount of light emitted from a region with a large amount of incident light can be suppressed, and the amount of light emitted from a region with a small amount of incident light can be increased. As a result, the amount of emitted light over each half-circumferential region divided into two with the virtual line L1 as a boundary can be made uniform, and the amount of emitted light over the entire circumference of the outer peripheral surface 11b of the cylindrical portion 11 "" "with opening can be made uniform.

  The omnidirectional illumination optical member 10 "" "" in the example of FIG. 9B is a modification of the omnidirectional illumination optical member 10 "" of the third embodiment shown in FIG. In the all-around illumination optical member 10 ″ ″ ″ ′, the individual exit surfaces 14a ′ formed over the entire periphery of the outer peripheral surface 11b of the cylindrical portion 11 ″ ″ ″ ′ with the opening are reflected by the second reflecting portion 16 ″ ′. As the distance from the first incident region of the light reflected by the second reflecting portion 16 "'increases along the direction in which the light to be propagated propagates through the inside of the cylindrical portion 10" ""' with the opening, the area Is getting bigger.

  According to the omnidirectional illumination optical member 10 "" "'in the example of FIG. 9B, the amount of light emitted from a region with a large amount of incident light on the outer peripheral surface 11b of the cylindrical portion 11" ""' with an opening is suppressed and incident. The amount of light emitted from a region with a small amount of light can be increased. As a result, the amount of emitted light can be made uniform over the entire periphery of the outer peripheral surface 11b of the cylindrical portion 11 "" "" with the opening.

  As mentioned above, although embodiment of this invention and its modification were demonstrated, this invention is not limited to a structure as described in each embodiment and its modification, In the implementation stage, the summary of invention is changed. The constituent elements can be modified and embodied within a range not to be performed. In addition, various inventions can be derived by appropriately combining a plurality of constituent elements described in each embodiment or its modification. For example, some constituent elements may be deleted from all the constituent elements described in each embodiment or its modification, or the constituent elements described in different embodiments or its modifications may be appropriately combined. Thus, various modifications and applications are possible without departing from the scope of the invention.

For example, in the omnidirectional illumination optical member of the embodiment and the modified example thereof, the first reflecting portion is provided on the entire inner peripheral surface, front end portion, and rear end portion of the cylindrical portion with the opening. In the omnidirectional illumination optical member of the modified example, the first reflecting portion is not provided, and only the total reflection surface 13 provided on the outer peripheral surface 11b is repeatedly reflected as shown in FIGS. 10 (a) and 10 (b). By doing so, it may be configured to perform all-around illumination.
In the omnidirectional illumination optical member of the above-described embodiment and its modified example, the illumination light guide portion includes a second reflection portion that includes a region facing the exit surface of the light guide member at the tip of the cylindrical portion with an opening. Although the second reflecting portion is provided in the region, the illumination light guiding portion may be configured without using the second reflecting portion.

  For example, as shown in FIGS. 10 (c) and 10 (d), a cylindrical portion with an opening is formed on one of the front end portion 11c and the rear end portion 11d, and between the front end portion 11c and the rear end portion 11d. A spiral surface 17a formed to have different thicknesses in the circumferential direction, a step formed on the spiral surface intersecting with the spiral surface 17a, and exiting from the exit portion of the illumination light supply means. There is a step forming surface 17b that enters the light in a direction deviating from the direction of the imaginary line L1 passing through the respective axes O1 and O2 of the cylindrical shape of the inner peripheral surface and the cylindrical shape of the outer peripheral surface, and guides the light into the cylindrical portion with the opening. The step forming surface 17b is used for the illumination light guiding portion. In this case, as shown in FIG. 10 (e), the emission part of the illumination light source such as the LED 22 as the illumination light supply means is disposed opposite to the step forming surface 17b, or is not shown in FIG. 10 (e). By arranging the exit end face of the light guide member such as a light guide as the illumination light supply means so as to face the step forming surface 17b, it is uniform over the entire circumference of the outer peripheral surface of the cylindrical portion with the opening as in the other embodiments. Light can be illuminated.

  Also, for example, as shown in FIG. 10 (f), the cylindrical portion with the opening is formed on either the front end portion 11c or the rear end portion 11d, and the thickness between the front end portion 11c and the rear end portion 11d is the circumference. A spiral surface 17a formed to be different along the direction, a step is formed on the spiral surface intersecting the spiral surface 17a, and the light emitted from the exit portion of the illumination light supply means is incident to the cylindrical surface with the opening. And forming the illumination light guide part into a shape having a step forming surface 17b that leads to the inside of the part, the light emitted from the emission part of the illumination light supply means, the cylindrical shape and the outer periphery of the inner peripheral surface of the cylindrical part with an opening The third reflecting portion 17c is reflected in a direction deviating from the direction of the imaginary line passing through each cylindrical axis of the surface and is incident on the step forming surface 17b. In this case, the light emitted from the light emitting end surface is incident on the third reflecting portion 17c such as the light guide 21 (or the light guide member that guides light from the light guide 21) as the illumination light supply means. Although not shown in FIG. 10 (f), the emission part of an illumination light source such as an LED as illumination light supply means is connected to the third reflection part 17c. By arranging so as to be incident, it is possible to illuminate uniform light over the entire periphery of the outer peripheral surface of the cylindrical portion with the opening as in the other embodiments.

  The omnidirectional illumination optical member of the present invention, the omnidirectional illumination optical system for an endoscope provided with the omnidirectional illumination optical endoscope, and the omnidirectional observation endoscope are fields in which observation over the entire circumference of the side is required for a tubular observation object. Useful for.

DESCRIPTION OF SYMBOLS 1 Endoscope for whole periphery observation 2 Objective optical system 2a, 19 Cylindrical sapphire cover glass 2b, 2c, 2d, 3b, 3c Lens 2e, 3a, 22 Cover glass 3 Imaging optical system 3d Imaging element 10, 10 ' 10 ", 10"', 10 "", 10 ""', 10 """,10"""'All-round illumination optical member 11, 11', 11 ", 11"', 11 "", 11 ""',11""", 11 """" Cylindrical portion 11a with opening Inner peripheral surface 11b Outer peripheral surface 11c Front end portion 11d Rear end portion 12 First reflecting portion 13 Total reflecting surface 14, 14' Convex portions 14a, 14a 'Exit surface 15 Light guide member 16, 16', 16 ", 16"'Second reflective portion 16a, 16b, 16a', 16b ', 16a ", 16b", 16c ", 16d" Reflective surface 17a Spiral surface 17b Step forming surface 17c Third reflecting portion 18 Housing 20 All around Meiko Science system 21 light guide 22 LED

Claims (20)

An omnidirectional illumination optical member that illuminates light from illumination light supply means eccentrically arranged at the endoscope distal end toward the entire circumference on the side of the endoscope distal end,
An inner peripheral surface and an outer peripheral surface that are made of a transparent medium and are formed in a cylindrical shape at coaxial or non-coaxial positions, and an annular front end and a rear end that are in contact with the inner peripheral surface and the outer peripheral surface, respectively. A cylindrical part with an opening having a part;
A part of light incident in a direction that can be totally reflected when incident on the total reflection surface and the total reflection surface, which are alternately formed over the entire circumference of the outer peripheral surface of the cylindrical portion with the opening, To the outside of the attached cylindrical portion, an emission surface that emits in an oblique direction with respect to the total reflection surface, and
An all-around illumination optical member comprising:   Provided on the inner peripheral surface, the front end portion and the rear end portion of the cylindrical portion with the opening, and enters the inner peripheral surface, the front end portion and the rear end portion through the inside of the cylindrical portion with the opening. The omnidirectional illumination optical member according to claim 1, further comprising a first reflecting portion that reflects light.   The light beam from the illumination light supply means deviates from the direction of an imaginary line passing through the respective axes of the cylindrical shape of the inner peripheral surface and the cylindrical shape of the outer peripheral surface of the column portion with the opening, and the column with the opening. The omnidirectional illumination optical member according to claim 1, further comprising an illumination light guide unit that is supplied to the inside of the unit.   The illumination light guide portion is formed in a predetermined region including a region facing the emission portion of the illumination light supply means at the tip of the cylindrical portion with the opening, and the cylindrical portion with the opening is formed by the illumination light supply means. The direction of the imaginary line passing through the respective axes of the cylindrical shape of the inner peripheral surface and the cylindrical shape of the outer peripheral surface of the cylindrical portion with the opening is supplied to the inside of the cylindrical portion with the opening and travels in the direction toward the tip of the cylindrical portion with the opening The omnidirectional illumination optical member according to claim 3, comprising a second reflecting portion that reflects in a direction deviating from the omnidirectional illumination member. Either one of the front end part and the rear end part in the cylindrical part with the opening is a spiral surface formed so that the thickness between the front end part and the rear end part varies along the circumferential direction; Each of the cylindrical shape of the inner peripheral surface and the cylindrical shape of the outer peripheral surface of the cylindrical portion with the opening that intersects the spiral surface and forms a step on the spiral surface and is emitted from the emitting portion of the illumination light supply means. Having a step forming surface that guides light in a direction deviating from the direction of an imaginary line passing through the axis of
The omnidirectional illumination optical member according to claim 3, wherein the illumination light guide portion includes the step forming surface. Either one of the front end part and the rear end part in the cylindrical part with the opening is a spiral surface formed so that the thickness between the front end part and the rear end part varies along the circumferential direction; Having a step forming surface that intersects the spiral surface and forms a step on the spiral surface, enters the light emitted from the emitting portion of the illumination light supply means, and guides the light into the cylindrical portion with the opening;
The illuminating light guide part emits light emitted from the emitting part of the illuminating light supply means to a virtual line passing through the respective axes of the cylindrical shape of the inner peripheral surface and the cylindrical shape of the outer peripheral surface of the cylindrical part with the opening. The omnidirectional illumination optical member according to claim 3, comprising a third reflecting portion that reflects in a direction deviating from the direction and enters the step forming surface.   Furthermore, it has a cylindrical-shaped sapphire cover glass which covers the perimeter of the said outer peripheral surface of the said column part with an opening, The all-around illumination optical member in any one of Claims 1-6 characterized by the above-mentioned.   5. The subordinate according to claim 4, wherein the second reflecting portion has two reflecting surfaces inclined in different directions with the virtual line as a boundary, and has a V-shaped cross section. The omnidirectional illumination optical member according to claim 7.   The said 2nd reflection part consists of a pyramid-shaped surface which has three or more reflective surfaces each inclined in a different direction centering | focusing on the virtual axis on the optical axis of the said illumination light supply means. The omnidirectional illumination optical member according to claim 7, which is dependent on 4 or claim 4. The outer peripheral surface of the cylindrical portion with the opening has a plurality of convex portions having a trapezoidal cross section formed at intervals over the entire circumference,
The omnidirectional illumination optical member according to claim 8 or 9, wherein the emission surface is a tapered surface of a convex portion having a trapezoidal cross section.   Each of the emission surfaces formed over the entire periphery of the outer peripheral surface of the cylindrical portion with the opening is in each half-circumferential region of the outer peripheral surface of the cylindrical portion with the opening divided into two with the virtual line as a boundary, The light reflected by the second reflecting part moves away from the first incident area of the light reflected by the second reflecting part along each direction in which the light propagates through the inside of the cylindrical part with the opening. Therefore, the arrangement | positioning space | interval is shortened, The all-around illumination optical member in any one of Claim 7, which depends on Claim 4, 8, 9, 10, and Claim 4.   Each of the emission surfaces formed over the entire periphery of the outer peripheral surface of the cylindrical portion with the opening is in each half-circumferential region of the outer peripheral surface of the cylindrical portion with the opening divided into two with the virtual line as a boundary, The light reflected by the second reflecting part moves away from the first incident area of the light reflected by the second reflecting part along each direction in which the light propagates through the inside of the cylindrical part with the opening. Accordingly, the omnidirectional illumination optical member according to any one of claims 4, 8, 9, 10, and 7 according to claim 4, wherein the area is large. The second reflection portion is supplied to the inside of the cylindrical portion with the opening by the illumination light supply means and travels in the tip direction of the cylindrical portion with the opening, in two directions with the virtual line as a boundary. It consists of one reflective surface that reflects in either direction,
The outer peripheral surface of the cylindrical portion with the opening is a convex portion having a plurality of inclined surfaces with different inclination angles with respect to the total reflection surface, which are formed in the same direction at intervals over the entire circumference. Have
5. The subordinate to claim 4, wherein the emission surface is an inclined surface having a large inclination angle with respect to the total reflection surface among the two inclined surfaces of the convex portion having a substantially triangular cross section. The all-around illumination optical member according to claim 7.   The individual exit surfaces formed over the entire circumference of the outer peripheral surface of the cylindrical portion with the opening are along the direction in which the light reflected by the second reflecting portion propagates inside the cylindrical portion with the opening. 14. The omnidirectional illumination optical member according to claim 13, wherein the arrangement interval becomes shorter as the distance from the first incident region of the light reflected by the second reflecting portion increases.   The individual exit surfaces formed over the entire circumference of the outer peripheral surface of the cylindrical portion with the opening are along the direction in which the light reflected by the second reflecting portion propagates inside the cylindrical portion with the opening. The omnidirectional illumination optical member according to claim 13, wherein the area increases as the distance from the first incident region of the light reflected by the second reflecting portion increases. The outer peripheral surface of the cylindrical portion with the opening is a convex portion having a plurality of inclined surfaces with different inclination angles with respect to the total reflection surface, which are formed in the same direction at intervals over the entire circumference. Have
The said output surface consists of an inclined surface with a large inclination | tilt angle with respect to the said total reflection surface among the said 2 inclined surfaces in the convex part with the said substantially triangular cross section. Or the all-around illumination optical member according to claim 7, which is dependent on 6.   Each of the emission surfaces formed over the entire circumference of the outer peripheral surface of the cylindrical portion with the opening is along the direction in which light incident from the step forming surface propagates inside the cylindrical portion with the opening, The omnidirectional illumination optical member according to claim 16, wherein the arrangement interval is shortened as the distance from the first incident region inside the cylindrical portion with the opening of the light incident from the step forming surface increases.   Each of the emission surfaces formed over the entire circumference of the outer peripheral surface of the cylindrical portion with the opening is along the direction in which light incident from the step forming surface propagates inside the cylindrical portion with the opening, The omnidirectional illumination optical member according to claim 16, wherein the area increases as the distance from the first incident region inside the cylindrical portion with the opening of the light incident from the step forming surface increases. Illumination light supply means;
The all-around illumination optical member according to any one of claims 1 to 18,
An omnidirectional illumination optical system for endoscopes.   An objective optical system that has a part of lenses in the opening of the all-around illumination optical system according to claim 19 and the cylindrical portion with the opening, and that observes an observation object that extends all around the side is provided at the distal end of the endoscope. An all-around observation endoscope.

Images