JP3302433B2 - Observation device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a medical observation apparatus such as an endoscope or an observation apparatus used for observing structures and internal structures of various devices.

[0002]

2. Description of the Related Art A medical endoscope or an observation apparatus such as a borescope or an image scope used for observing the internal structure of a structure or various devices is, for example, a gradient index image transmission body, an image fiber or a relay. It has a thin part including an elongated image transmitting body such as an image transmitting body having a lens structure, and the thin part is inserted into a body or the inside of a device for observation. Therefore, the thinner part is one of the performance factors of these observation devices.

[0003] These observation apparatuses generally have a self-illumination system using a light fiber bundle along a narrow portion as a light guide, and the quality of the illumination system greatly affects the performance. Specifically, for example, it is required that a necessary portion can be illuminated accurately and efficiently. For this reason, high precision is required for the processing of the lighting end of the light guide, and as a result, the processing cost is increased.

Furthermore, in the case of medical endoscopes and the like, if possible to prevent infection and the like, a part which may come into contact with human tissues or body fluids, that is, a thin part is made into a detachable unit to be a disposable type. Is strongly desired. However, in conventional endoscopes and the like, since the self-illuminating light guide has a structure that is mechanically integrated with the slender part, it is difficult to make the slender part detachable unit. Even if it is possible, the price of the unit cannot be avoided, and it becomes difficult to dispose it.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances. For an observation apparatus having a thin portion including an elongated image transmitting body, the thin portion can be made thinner. In addition, a structure that enables more accurate and efficient illumination of a necessary part, makes it easier to attach / detach the slender part, and can process the detachable unit at a low cost suitable for disposable is provided. Things.

[0006]

According to the present invention, there is provided an observation apparatus including an elongated image transmitting body for capturing an image of an observation object and an illumination system for illuminating the observation object. The provided illumination light is condensed on the exit end face of the image transmission body and made incident on the image transmission body, and the illumination system is arranged so that the illumination light incident on the image transmission body is irradiated on an observation object by propagation in the image transmission body. Therefore, as one structure, a light source system is formed by a light emitting source and a plurality of optical fibers for guiding illumination light from the light emitting source, and a plurality of optical fibers are provided in an appropriate number. A unit bundle is provided, and while the tips of the unit bundles are arranged in a ring, a condensing lens is provided corresponding to the ring arrangement of the unit bundle, and illumination from an optical fiber is performed by the condensing lens in the ring arrangement. Light is emitted around the exit end face of the image transmitter. In order to converge annularly on the portion, as another structure, it includes an elongated small diameter portion and a large diameter portion integrally formed at one end of the small diameter portion, and includes a small diameter portion and a large diameter portion. In the meantime, a refractive index distribution type optical transmission body having a diameter continuously changing and having a continuous diameter changing portion accompanied by a continuous change of a refractive index distribution state corresponding to the continuous change of the diameter is used as a light source. In this system, illumination light from a light emitting source, which is incident on the optical transmission body from the end face of the large-diameter portion, is applied to the emission end face of the image transmission body from the end face of the small-diameter portion.

In each of these structures, an image transmission body, which is an image transmission path, is also used as an illumination light transmission path.
Illumination light incident from the exit end face of the image transmission body propagates through the image transmission body in a direction opposite to that of the image light, exits from the entrance end face of the image transmission body, and illuminates the observation object. As a result, the image capturing range and the illumination range match, and more accurate and efficient illumination of a necessary part is enabled. In addition, there is no need to make the light guide of the illumination system along the slender part as in the past,
The slender part can be made thinner. Furthermore, in the case of the detachable unit of the slender part, the main element is only the image transmission body, so that the detachable unit can be easily formed and the cost can be reduced.

In particular, in the case of a structure in which an optical fiber and a condensing lens are combined, it is possible to send more powerful illumination light into the image transmission body without causing interference that may hinder the image transmission system. it can. That is, since the illumination light from the optical fiber is converged annularly on the periphery of the exit end face of the image transmission body by the condensing lens in the annular arrangement, the periphery of the image transmission body is effectively used, The strong illumination light can be sent into the image transmission body without affecting the image light emitted from the exit end face of the image transmission body.

In the case of using an optical transmission body having a continuous diameter changing portion, a very strong illumination light can be provided with a simple structure,
Moreover, the light can be sent into the image transmission body without causing interference that may interfere with the image transmission system. That is, this optical transmission body has a self-focusing function by its continuous diameter change portion, and enables light collection at a magnification corresponding to the ratio of the cross-sectional area of the large-diameter portion to the cross-sectional area of the small-diameter portion, For example, the diameter of the large diameter part is cm
By setting the diameter of the small-diameter portion on the order of mm or less, it is possible to supply illumination light with a condensing power of several hundred to several thousand times. Also, if the small-diameter portion is extremely thin, such as not more than mm, even if the small-diameter portion covers the exit end face of the image transmission body, the effect on the image light emitted from the exit end face of the image transmission body is ignored. Therefore, it is possible to adopt the simplest structure of irradiating illumination light into the image transmission body with the end face of the narrow diameter part directly facing the center of the emission end face of the image transmission body. Become.

In both of the structure using the condensing lens and the structure using the self-condensing type optical transmitter, it is preferable to use a gradient index type image transmitter as the elongated image transmitter. In addition to the refractive index distribution type image transmitter, for example, the above-mentioned image fiber or relay type image transmitter can be used.

[0011] The image transmission body of the refractive index distribution type includes an elongated small diameter portion and a large diameter portion integrally formed at one end of the small diameter portion. By using a refractive index distribution type image transmission body having a continuous diameter changing portion with a continuously changing diameter and a continuously changing refractive index distribution state corresponding to the continuous change of the diameter, More preferred. That is, according to such a refractive index distribution type image transmission body, since the diameter of the exit end face is large, more illumination light can be efficiently incident, and a stronger illumination power can be obtained.

The above-described refractive index distribution type optical transmission body having a different diameter structure can be formed by an interfacial gel polymerization method when a polymer material is used. The basic process of this interfacial gel polymerization method is as follows.

That is, in the interfacial gel polymerization method, a mixture of a plurality of monomers or unreacted molecules, each having a different refractive index and a different molecular size, is converted into a material having high affinity for the monomers and unreacted molecules in the mixture, For example, polymerization is performed in a specific direction by using the gel effect in a polymerization tube formed of a specific monomer or unreacted molecule of the mixed solution or a polymer raw material of the same type as the mixed solution itself. The refractive index distribution in the radial direction is obtained by mixing and distributing a plurality of monomers or unreacted molecules having different refractive indexes at different ratios from the central axis to the periphery of the polymerization tube due to the difference in the diffusivity of the molecules. (For example, Japanese Patent Laid-Open No. 4-97302).
No. JP-A-4-97303).

As a method for carrying out such an interfacial gel polymerization method, there are, for example, an injection method and a dropping method. The injection method is
This is a method in which a required amount of a mixture of monomers or unreacted molecules is injected all at once into a polymerization tube, and then polymerization is performed while rotating the polymerization tube. On the other hand, the dropping method is a method in which a predetermined amount of a mixed solution of a monomer or unreacted molecules is dropped into a polymerization tube, the polymerization is advanced for each drop, and the polymerization tube is finally filled with a polymer solid. .

The following two methods are possible for forming the optical transmission body according to the present invention using the above-described interfacial gel polymerization method. One is a pure drawing method, which is a method to which a method commonly used as a conventional optical fiber manufacturing method is applied. Specifically, first, an intermediate (also referred to as a preform) is formed into a columnar shape having a uniform thickness by using an injection method or a dropping method, and then one end side of the intermediate is heated and softened and partially stretched. Thereby, an elongated narrow diameter portion is formed. Here, what is important as the present invention is to leave a part of the intermediate having a large diameter as a large diameter portion and to leave it integrally with the small diameter portion, and to expand the diameter between the large diameter portion and the small diameter portion by stretching. The purpose is to form a continuous diameter change portion in which the state of change is controlled. As described above, in the continuous diameter changing portion controlled to a predetermined state, the refractive index distribution state in the intermediate body continuously changes in a similar manner in a manner corresponding to the continuous change in the diameter.

The other is a mixing method, which differs from the pure stretching method in that a molding element is incorporated into the processing of an intermediate.
Specifically, an intermediate is formed by using a polymerization tube molded into a preliminary shape serving as a skeleton of the shape of the optical transmission body to be finally obtained, and the intermediate is formed in the same manner as in the pure stretching method described above. Processing to obtain the desired optical transmitter. In this case, a dropping method is used for forming the intermediate. That is, a polymer solid is formed while a mixture of monomers or unreacted molecules is sequentially dropped under a predetermined control condition into a polymerization tube formed in a preliminary shape. In this process, in the continuous diameter changing portion of the polymerization tube provided in advance, the mixed solution of the monomer or unreacted molecule which is sequentially dropped forms polymerization under the condition of a different diameter for each drop, and in this polymerization, The mixing distribution ratio of different monomers or unreacted molecules differs according to the difference in the diameter condition, and the mixture ratios are stacked to obtain a continuous change in the refractive index distribution state.

The following can be used as the polymer raw material that can be used in the interfacial gel polymerization method. M
MA (Methyl Methacrylate, molecular size; 104.4, refractive index; 1.492), BBP (Benzyl n-Butyl Phthalate, molecular size; 301.1, refractive index; 1.541), BzMA (Benzyl Meth
acrylate, molecular size; 180.0, refractive index; 1.562), VB (V
inyl Benzoate, molecular size; 145.9, refractive index; 1.578),
PhMA (Phenyl Methacrylate, molecular size; 162.8, refractive index; 1.570), VPAc (Vinyl Phenylacetate, molecular size; 163.2, refractive index; 1.567).

[0018]

Embodiments of the present invention will be described below. This embodiment is an example relating to a video-type observation apparatus including an imaging device 1 shown in FIG. 1 using a solid-state imaging device and a monitor display (not shown) for reproducing and displaying an image of an observation object captured by the imaging device 1. The imaging device 1 including the features of the present invention includes a main body 2 and an image transmission unit 3.

The main body 2 has a cylindrical shape and incorporates a camera unit 4 therein, a light source system unit 5 forming a light source system which is a part of an illumination system, and a signal from the imaging unit 4. A light source cable 8 in which a large number of optical fibers 7, 7,... Included in the cable 6 and the light source system unit 5 are bundled extends to the outside.

As shown in FIG. 2, the image pickup unit 4 has apertures 11, 11 for preventing a solid-state image pickup device 10 and a flare of a camera unit inside a light-shielding tube 9 having a conically narrow front end portion. , ..., etc. are provided.

The light source system unit 5 has a number of optical fibers 7, 7,... For guiding illumination light from an external light source, and emits light from the distal end surface of the optical fibers 7, 7,. The illumination light to be emitted is transmitted to an exit end face 1 of an image transmission body 19 described later.
The light-collecting system unit 12 forms an annular image on the periphery of the light-receiving surface 9i and collects light.

The condensing system unit 12 is formed by assembling an appropriate number of imaging lenses 13 and a collimator lens 14 provided corresponding to each of the imaging lenses 13 to a frame body (not shown). , Each collimator lens 14
, An optical fiber bundle 7b in units of an appropriate number of optical fibers 7, 7,... Then, the illumination light L imaged by the light collecting unit 12
Is incident on the image transmission body 19 from the periphery of the exit end face 19i, propagates through the inside, and irradiates the observation object M.

The image transmission unit 3 includes an elongated protective cylinder 16.
A cover glass 17, an objective lens 18,
In addition, an image transmission body 19 of a refractive index distribution type is arranged, and a screw member 20 is attached to the base end of the protective tube 16 so that the screw member 20 can be attached to and detached from the main body 2 via the screw member 20. Have been.

FIG. 3 shows an example in which a gradient index image transmission body 30 having a special structure is used as a modification of the above embodiment. That is, the end face of the image transmission body 30 is the exit end face 3.
1 and a large-diameter portion 32 whose end face is the incident end face 33
A continuous diameter changing portion 35 whose diameter continuously decreases from the large-diameter portion 32 side to the small-diameter portion 34 side is formed between the small-diameter portion 34 and the elongated small-diameter portion 34.

The image transmission body 30 transmits an image along an optical path trajectory T 'as shown by a one-dot chain line in FIG.
In the case of, the image incident from the incident end face 33 is transmitted at the same magnification as in the ordinary refractive index distribution type image transmission body, but gradually expands from the continuous diameter changing portion 35 to the large diameter portion 32, and finally, Is formed on the light receiving surface 10f of the solid-state imaging device 10 as an image having a magnification corresponding to the ratio of the diameter of the exit end surface 31 to the diameter of the incident end surface 33.

On the other hand, the illuminating light L from the light condensing system unit 12 which enters the image transmission body 30 from the exit end face 31 propagates through the image transmission body 30 in the opposite direction to the above-described image transmission and from the incidence end face 33. The observation object is irradiated. In other words, the illumination light incident from the large-diameter exit end face 31 is
The object is irradiated from the small-diameter incident end face 33 while being focused. According to such an image transmission body 30, the illumination light from the light condensing system unit 12 can be efficiently incident, and since the image transmission body 30 itself has a condensing power, an extremely strong illumination power can be obtained. Can be.

In this example, the image forming surface of the image transmission body 30 is formed on the light receiving surface 10f of the solid-state image pickup device 10 located at a position away from the exit end surface 31, but the incident end surface 33 is provided.
By adjusting the relationship between the distance between the light source and the exit end face 31 and the pitch number of the optical path locus T ′, an image plane can be formed on the exit end face 31. However, in that case, it is necessary to provide an imaging system between the solid-state imaging device 10 and the solid-state imaging device 10. Further, the large-diameter portion 32 having a certain length is formed in the image transmission body 30 in this example, but it is not always necessary to provide such a large-diameter portion 32, and one end of the continuous diameter changing portion 35 is provided. A structure that provides the emission end face 31 is also possible.

FIG. 4 shows an example in which an optical transmission body 40 having the same structure as the image transmission body 30 in the second embodiment is used as a light-collecting system. That is, the light transmitting body 40 used for the light condensing system has a short large-diameter portion 42 having a first end face 41 (corresponding to the exit end face 31 of the image transmitting body 30) having a diameter of about 1 cm, and about 0.5 mm. A continuous diameter changing portion 45 is formed between the elongated portion 44 having a second end surface 43 (corresponding to the incident end surface 33 of the image transmission body 30) having a diameter of In the same manner as described above, the illumination light is condensedly transmitted.

The light transmitting body 40 is formed by bending the small diameter portion 44 by the flexibility of the first end face 41.
Faces the exit end face of the optical fiber bundle 47, while the second
The end face 43 is disposed between the exit end face of the optical fiber bundle 47 and the exit end face 19i of the image transmission body 19 with the end face 43 facing a substantially central portion of the exit end face 19i of the image transmission body 19. That is, the illumination light L from the optical fiber bundle 47 is incident on the optical transmission body 40 from the first end face 41 and is converted into a strong illumination light that is condensed about 400 times by the simple calculation in the continuous diameter changing section 45. The light is emitted from the second end face 43 to the emission end face 19i of the image transmission body 19, and further propagates in the image transmission body 19 to irradiate the observation object.

FIG. 5 shows a modification of the embodiment shown in FIG. 4, in which an optical transmission body 50 having a sufficiently long narrow portion 54 is used as a light source system. That is, in this example, the large diameter portion 52 of the light transmission body 50 directly faces the external light source Ls, unlike the light transmission body 40 in the embodiment of FIG. After the illumination light L from the light emitting source Ls incident from the first end face 51 of the large diameter portion 52 is collected by the continuous diameter changing portion 55, the image transmission body 19 is formed by the sufficiently small diameter portion 54. Is guided to the emission end face 19i.

In each of the embodiments described above, a gradient index type image transmitting member is used as the image transmitting member. Alternatively, for example, a well-known image fiber or a relay having a relay structure as shown in FIG. An image transmitting body 60, that is, an image transmitting body or the like that transmits an image by repeating the same-magnification imaging with a plurality of lenses 61a and 61b arranged in series can be used.

[0032]

As described above, the observing device according to the present invention uses the elongated image transmitting body, which is the image transmitting path, also as the transmitting path for the illumination light, so that the required portion can be more accurately determined. In addition, efficient illumination is possible, the slender part can be made thinner, and the slender part can be made into a detachable unit at low cost. In particular, by using a structure combining an optical fiber and a condensing lens and a structure using an optical transmission body having a continuous diameter changing portion, more powerful illumination light may be an obstacle to the image transmission system. Since the image can be fed into the image transmission body without causing interference, the above advantages can be more effectively exhibited.

[Brief description of the drawings]

FIG. 1 is a side view including a partial cross section of an imaging device according to an embodiment of the present invention.

FIG. 2 is a partially enlarged cross-sectional view of the imaging device of FIG.

FIG. 3 is a partial configuration diagram of an imaging device according to a second embodiment of the present invention.

FIG. 4 is a partial configuration diagram of an imaging device according to a third embodiment of the present invention.

FIG. 5 is a partial configuration diagram of an imaging device according to a fourth embodiment of the present invention.

FIG. 6 is a sectional view of an image transmission body according to another example.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 imaging device 2 main body unit 3 image transmission unit 5 light source system unit 7 optical fiber 7 b optical fiber bundle (unit bundle) 10 imaging element 10 f light receiving surface 13 imaging lens 19 image transmission unit 19 i emission end face 30 image transmission unit 31 emission End face 33 Incident end face 35 Continuous diameter changing part 40 Optical transmission body 41 First end face 43 Second end face 45 Continuous diameter changing part M Observation object L Illumination light

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G02B 23/26 A61B 1/06

Claims (4)

(57) [Claims] An illumination system for illuminating an observation object is provided. The illumination system is provided with an illumination system for illuminating the observation object. An observation apparatus which is formed so as to collectively enter an image transmission body from an exit end face of the transmission body and irradiate an illumination object incident on the image transmission body to an observation object by propagation in the image transmission body. A light source system is formed by a light emitting source and a plurality of optical fibers for guiding illumination light from the light emitting source, and a plurality of optical fibers are formed into an appropriate number of unit bundles, and the ends of each unit bundle are arranged in a ring. On the other hand, a condensing lens is provided corresponding to the annular arrangement of the unit bundle, and the illumination light from the optical fiber is annularly formed on the periphery of the exit end face of the image transmission body by the condensing lens having the annular arrangement. An observation apparatus characterized in that light is condensed. 2. An illumination system for illuminating an observation object, comprising an elongated image transmission body for capturing an image of the observation object, and an illumination system for illuminating the observation object. An observation apparatus which is formed so as to collectively enter an image transmission body from an exit end face of the transmission body and irradiate an illumination object incident on the image transmission body to an observation object by propagation in the image transmission body. , An elongated narrow portion and a large diameter portion integrally formed at one end of the small diameter portion, wherein the diameter continuously changes between the small diameter portion and the large diameter portion and the diameter is continuously changed. Using a refractive index distribution type optical transmission body having a continuous diameter change portion with a continuous change of the refractive index distribution state corresponding to the change in the light source system,
An observation apparatus characterized in that illumination light from a light emitting source, which is made incident on the light transmitting body from the end face of the large diameter part, is emitted from the end face of the small diameter part to the emission end face of the image transmitting body. 3. The observation device according to claim 1, wherein a refractive index distribution type image transmission body is used as the image transmission body. 4. An image transmission body of a refractive index distribution type includes an elongated small diameter portion and a large diameter portion integrally formed at one end of the small diameter portion, and a portion between the small diameter portion and the large diameter portion. 4. The observation apparatus according to claim 3, further comprising a continuous diameter changing portion having a continuously changing diameter and a continuous change in a refractive index distribution state corresponding to the continuous change in the diameter. .