JP3581408B2 - Stereoscopic rigid endoscope - Google Patents

Description

[0001]
[Industrial applications]
The present invention relates to a rigid stereoscopic endoscope for stereoscopically observing and photographing an object using a rigid endoscope, and more particularly, to an improvement in illumination means of the rigid stereoscopic endoscope.
[0002]
[Prior art]
The stereoscopic rigid endoscope includes an objective lens that forms an object image, a relay lens that transmits the image, a pupil splitting unit that splits the image transmitted by the relay lens into left and right, and observes the two split images, Alternatively, it is provided with an imaging means, and is used for medical use for observing a site in a body cavity, or for industrial use for observing the inside of a machine such as an engine.
[0003]
The endoscope requires illumination means for illuminating an object, and the illumination means has a configuration in which a light flux from a light source provided on the observation unit side is guided to the distal end of the insertion unit by a light guide fiber bundle or the like. Widely used.
[0004]
For example, in U.S. Pat. No. 4,364,629, the cross-sectional shape of an objective lens and a relay lens arranged in an insertion portion is made elliptical so as to cover only a portion through which a light beam used for stereoscopic vision is transmitted, and a short side is provided. A configuration in which a fiber for illumination is arranged in a space in a direction is disclosed.
[0005]
[Problems to be solved by the invention]
However, in the above-described conventional stereoscopic rigid endoscope, it is necessary to separately provide an optical system for transmitting an image and a light guide fiber bundle for transmitting illumination light. In addition, when an elliptical lens is used so that the diameter of the insertion portion does not increase, the manufacturing cost of this lens is higher than that of a normal circular lens, so that there is a problem that the cost of the entire endoscope becomes higher. is there.
[0006]
[Object of the invention]
The present invention has been made in view of the above-described problems of the related art, and has a stereoscopic view capable of transmitting illumination light to a distal end of an insertion section without disposing a light guide fiber bundle for illumination in the insertion section. An object of the present invention is to provide a rigid endoscope.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, a stereoscopic rigid endoscope according to the present invention has a primary optical system having an objective lens system and a relay lens system arranged in order from the object side, and a primary optical system disposed at a pupil position of the primary optical system. Pupil dividing means for dividing the luminous flux in the pupil into two regions, a pair of secondary optical systems for observing respective images formed by the luminous fluxes divided by the pupil dividing means, and secondary optics in the pupil Illumination means arranged so that illumination light enters the primary optical system from a region other than the observation target region by the system.
[0008]
【Example】
Hereinafter, an embodiment of a stereoscopic rigid endoscope according to the present invention will be described. As shown in FIG. 1, the stereoscopic rigid endoscope according to the embodiment includes a tubular insertion portion 1 inserted into a narrow space such as a body cavity, and an observation portion connected to a proximal end side of the insertion portion 1. Unit 2.
[0009]
Inside the insertion section 1, a first relay lens system 12 including a three-piece objective lens system 11 for forming an image of an object and a plurality of lenses for transmitting an image formed by the objective lens system 11 is provided. And a second relay lens system 13 forming an exit pupil are arranged in order from the object side, and these lens systems constitute the primary optical system 10.
[0010]
In the observation section 2, a roof mirror 21 as pupil splitting means is arranged so as to coincide with the pupil Ep of the primary optical system 10, and each of the left and right optical paths split by the roof mirror 21 is provided with an imaging lens 22 respectively. , A mirror 23, and an eyepiece 24, a pair of secondary optical systems 20a and 20b are arranged.
[0011]
In this specification, the optical system on the object side of the pupil dividing means is defined as a primary optical system, and the optical system on the observation side is defined as a secondary optical system.
[0012]
In the observation unit 2, illumination means 30 is arranged so that illumination light enters the second relay lens system 13 from a region other than the observation target region by the secondary optical systems 20 a and 20 b in the pupil Ep. The illumination means 30 includes a light source 31, a condenser lens 32, and a light guide fiber bundle 33.
[0013]
The light L0 from the object passes through the objective lens system 11, the first relay lens system 12, and the second relay lens system 13 of the primary optical system 10 to the position of the pupil Ep, as shown by the broken line in FIG. Reach. When observing with one eye, an object can be observed by placing an eye at the position of the pupil Ep of the primary optical system 10.
[0014]
In the stereoscopic rigid endoscope of the embodiment, a roof mirror 21 for dividing the pupil Ep is arranged at the position of the pupil Ep, and a secondary optical system having an imaging lens 22 and an eyepiece 24 in each of the divided optical paths. The arrangement of 20a and 20b enables observation with both eyes. In the embodiment, the observer observes the image by directly looking into the eyepiece lens 24. However, an image sensor such as a CCD is arranged on the image plane of the imaging lens 22, and the photographed image is observed on the display. It can also be configured to be.
[0015]
In order to enable stereoscopic vision, it is necessary to observe one object from different directions, and for that purpose, it is necessary to guide the light beams passing through different regions in the pupil to the secondary optical systems 20a and 20b. is there. Therefore, in the embodiment, the pupil is divided right and left by the roof mirror 21, and the optical axes Ax0 of the primary optical system 10 and the optical axes Ax1 and Ax2 of the secondary optical systems 20a and 20b are shifted before and after the division. ing.
[0016]
As shown in FIG. 2A, the roof mirror 21 has a split line that is arranged so as to coincide with the optical axis Ax0 of the primary optical system 10, whereas the split beams of the secondary optical systems 20a and 20b are split. The axes Ax1 and Ax2 are shifted so as to coincide with the centers of the pupils E1 and E2 of the secondary optical system to be divided. Therefore, when the optical axes Ax1 and Ax2 of the secondary optical systems 20a and 20b are traced to the object side in reverse, it can be understood that one object can be observed with a parallax from different directions by the secondary optical systems 20a and 20b. Therefore, stereoscopic viewing is possible by looking at one of the secondary optical systems with the left eye and the other with the right eye.
[0017]
When the pupil is divided by the roof mirror 21 in this manner, if the pupil Ep of the primary optical system 10 and the pupils E1 and E2 of the secondary optical systems 20a and 20b are all circular as shown in FIG. The diameters of the pupils E1 and E2 of the secondary optical systems 20a and 20b are half of the diameter of the pupil Ep of the primary optical system 10 at the maximum, and a region which does not overlap with the pupils E1 and E2 in the pupil Ep is It will not contribute to transmission.
[0018]
The illuminating means 30 is arranged so that the illuminating lights L1 and L2 are incident from a region on the pupil Ep that does not contribute to observation. In this embodiment, the end face of the light guide fiber bundle 33 that guides the illumination light is formed so as to coincide with the incident area of the illumination lights L1 and L2, and is arranged adjacent to the roof mirror 21.
[0019]
Illumination light that has entered the primary optical system 10 from the pupil Ep is transmitted to the object side via the second relay lens system 13, the first relay lens system 12, and the objective lens system 11. Since the luminous flux from all points in the observation visual field has reached each point in the pupil Ep of the primary optical system 10, conversely, the luminous flux incident from the pupil Ep reaches all the areas in the visual field. This will be illuminated.
[0020]
FIG. 3A shows another embodiment of the stereoscopic rigid endoscope according to the present invention. Since the primary optical system 10 is the same as that of the above embodiment, only the second relay lens system 13 located closest to the image is shown.
[0021]
In this embodiment, a pair of separator lenses 25, 25 for re-forming an image of an object are arranged at the position of the pupil Ep of the primary optical system 10 as pupil dividing means, and are incident on the image planes of these separator lenses 25, 25. Image guide fiber bundles 26, 26 are provided so that the end faces coincide with each other, and eyepiece lenses 27, 27 for observing an image formed on the exit side end surface of the image guide fiber bundles 26, 26 are provided. I have.
[0022]
The illuminating means 30 includes a light source 31, a condenser lens 32, and a light guide fiber bundle 33 as in the above-described embodiment, and is arranged so that the illuminating light enters from the pupil Ep of the primary optical system 10.
[0023]
As shown in FIG. 3 (B), the separator lenses 25, 25 are provided so as to circumscribe each other and to be inscribed in the pupil Ep. Are arranged so as to enter the primary optical system 10 from a region other than the region where the separator lens is disposed.
[0024]
【The invention's effect】
As described above, according to the present invention, the illumination light is transmitted using the portion of the primary optical system through which the light beam used for observation does not pass, so that a separate unit such as a light guide fiber bundle is used. Without reducing the number of parts, the illumination light can be transmitted without reducing the cost of the rigid endoscope, and the diameter of the insertion portion can be reduced without using a conventional elliptical lens. Can be kept.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram of an entire optical system showing one embodiment of a stereoscopic rigid endoscope according to the present invention.
FIG. 2A is an enlarged view of a roof mirror portion in FIG. 1, and FIG. 2B is an explanatory diagram showing a positional relationship of a light beam on a pupil.
3A and 3B show another embodiment of a stereoscopic rigid endoscope according to the present invention, wherein FIG. 3A is an explanatory view of a part of an optical system, and FIG. 3B is an explanatory view showing a positional relationship of a light beam on a pupil. FIG.
[Explanation of symbols]
Reference Signs List 1 Insertion unit 2 Observation unit 10 Primary optical system 11 Objective lens system 12 First relay lens system 13 Second relay lens system 20a, 20b Secondary optical system 21 Dach mirror 30 Illuminating means 31 Light source 32 Condenser lens 33 Light guide fiber bundle

Claims (3)

A primary optical system having an objective lens system and a relay lens system arranged in order from the object side,
Pupil dividing means arranged at a pupil position of the primary optical system and dividing a light beam in the pupil into two regions;
A pair of secondary optical systems for observing each image formed by the light flux split by the pupil splitting means,
A stereoscopic hard endoscope, comprising: an illumination unit arranged to cause illumination light to enter the primary optical system from a region other than a region to be observed by the secondary optical system in the pupil. The stereoscopic rigid endoscope according to claim 1, wherein the pupils of the primary optical system and the secondary optical system are all circular. The stereoscopic rigidity according to claim 1 , wherein the primary optical system is shared for transmitting an image of the object and transmitting illumination light from the illumination unit. Endoscope.

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