JPH06202006A - Stereoscopic hard endoscope - Google Patents

Abstract

PURPOSE:To enable stereoscopy to be carried out with a desired stereoscopic feeling without reference to the distance to a subject by adjusting the stereoscopic feeling of an obtained image at need. CONSTITUTION:The stereoscopic hard endoscope is equipped with an objective system 11, a relay lens system 12, an image forming lens 13, a focusing lens 14, and a pupil splitting prism 15, and an image which is formed by the objective system 11 and transmitted by the relay lens system 12 is split into two right and left images by the pupil splitting prism 15. A variable stop 16 which varies the interval between the centers of gravity of a right and a left pupil is arranged nearby the pupil splitting prism 15, and the interval between the centers of gravity of the right and left pupils is varied at need by displacing the variable stop 16. Consequently, the stereoscopic feeling can be adjusted by varying the angle of convergence with a body.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stereoscopic rigid endoscope capable of stereoscopically observing an observation site.

[0002]

2. Description of the Related Art Endoscope devices are widely used which are capable of observing an inspected site that cannot be visually observed by inserting an elongated insertion part into a body cavity or the like. In a normal endoscope apparatus, since the site to be examined can be seen only as a plane without perspective, it is difficult to observe, for example, minute irregularities on the surface of the body cavity wall, and diagnosis or endoscopic observation is performed. There was a problem that various treatments could not be performed easily.

Therefore, a plurality of observation optical systems are provided in parallel,
Conventionally, a stereoscopic endoscope device has been proposed in which the observation optical system is arranged so as to have parallax by setting the convergence angle formed by the optical axes of these optical systems, and the observation site can be stereoscopically viewed. ing.

As such a stereoscopic endoscope apparatus, for example, in Japanese Patent Laid-Open No. 57-69839, a pair of image transmission optical systems is internally provided in the insertion portion of the endoscope, and this image transmission optical system is provided. A pair of objective optical system is provided on the tip side, and a pair of eyepiece optical system is provided on the side of the hand operation part, so that the observation site is seen three-dimensionally by adjusting the vergence angle formed by the pair of objective optical systems. A device has been proposed.

FIG. 10 shows a schematic structure of a conventional stereoscopic endoscope. The stereoscopic endoscope 51 includes two objective lens systems 52a and 52b at the distal end portion of the elongated insertion portion, and relay lens systems 53a and 53b that transmit an image formed by the objective lens systems 52a and 52b. The respective images are picked up by solid-state image pickup devices 54a and 54b such as CCD.

In such a stereoscopic endoscope, the convergence angle changes as the distance to the subject changes. Therefore, when the subject is closer, the convergence angle increases as shown by the broken line in FIG. On the other hand, if you go far, the stereoscopic effect becomes weaker. That is, the stereoscopic effect of the obtained image changes depending on the distance to the subject.

[0007] For example, when a stereoscopic endoscope is used in a surgical operation, the operator feels the same feeling by observing the site to be inspected near and far, with almost the same stereoscopic effect. There is a demand to perform a procedure. However, the above-described stereoscopic endoscope cannot satisfy such a requirement because the stereoscopic effect at the near point is large and the stereoscopic effect at the far point is small.

[0008]

As described above, in the conventional stereoscopic endoscope, the convergence angle changes depending on the distance to the subject, and the stereoscopic effect of the obtained image changes, so that the stereoscopic effect is always observed. There was a problem that I could not do it.

On the contrary, there is also a demand for observing at a far point and a near point in a stereoscopic state that is easy to see according to the respective subjects, but it is necessary to adjust so that a desired stereoscopic effect can be obtained at a certain object distance. Was also difficult.

The present invention has been made in view of these circumstances, and the stereoscopic effect of an image obtained can be adjusted as necessary, and stereoscopic viewing can be performed with a desired stereoscopic effect regardless of the distance to the subject. An object is to provide a stereoscopic rigid endoscope that can be performed.

[0011]

A stereoscopic rigid endoscope according to the present invention is formed by an objective lens system having a single optical axis and arranged coaxially with the objective lens system. At least one relay lens system for transmitting an object image, a pupil position of the relay lens system or in the vicinity thereof, or a pupil division means for dividing the pupil into a plurality of positions, and the pupil division A plurality of pupils, which are arranged in the vicinity of the means or at a conjugate position thereof and change the center-of-gravity distances of the plurality of pupils; An image forming optical system for forming an object image and an image pickup means for receiving each of the object images are provided.

[0012]

The pupil distance converting means changes the distance between the centers of gravity of the plurality of pupils divided by the pupil dividing means to change the vergence angle.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 4 relate to a first embodiment of the present invention, FIG. 1 is an explanatory diagram showing a configuration of a main part of a stereoscopic rigid endoscope, and FIG. 2 is an explanatory diagram showing an external configuration of a stereoscopic rigid endoscope. FIG. 3 is an explanatory diagram showing a first configuration example of the variable aperture, and FIG. 4 is an explanatory diagram showing a second configuration example of the variable aperture.

As shown in FIG. 2, a stereoscopic rigid endoscope 1
(Hereinafter, also simply referred to as an endoscope) has an elongated and hard insertion portion 2, and a grip portion 3 is connected to a proximal end portion of the insertion portion 2. A cable 4 extends from the grip portion 3, and the stereoscopic rigid endoscope 1 is connected to the signal processing device 5 via the cable 4. The signal processing device 5 has a CR
A display device 6 such as a T monitor is connected so that the left and right two observation images obtained by the endoscope 1 are processed by the signal processing device 5 and displayed on the display device 6 as a stereoscopic endoscopic image. It has become. For example, by displaying the left and right two images on the display device 6 alternately and observing them with polarizing glasses,
It is possible to observe a subject image having a stereoscopic effect.

The main part including the optical system of the stereoscopic rigid endoscope 1 is configured as shown in FIG. One objective lens system 11 is provided at the tip of the endoscope 1, and a relay lens system 12 for transmitting a subject image formed by the objective lens system 11 is coaxially provided behind the objective lens system 11. It is arranged. Behind the relay lens system 12, the imaging lens 1
3 and a focusing lens 14 are provided, and a pupil division prism 15 is provided behind the focusing lens 14 at a position conjugate with the pupils of the objective lens system 11 and the relay lens system 12. That is, an image formed by the objective lens system 11 having a single optical axis is transferred to the relay lens system 12
And the pupil splitting prism 15 splits the pupil into two left and right images.

In the optical path near the pupil division prism 15,
A variable diaphragm 16 is provided as a pupil distance conversion means for changing the distance between the centers of gravity of the pupils. Then, the pupil division prism 15
Mirrors 1 that respectively reflect the light beams split by
7 and 18 are provided, and solid-state image pickup devices 19 and 20 such as CCDs are provided at the imaging positions of the imaging lens 13 behind the mirrors 17 and 18, respectively. Solid-state image sensor 19, 2
0 captures an image by subjecting the subject images formed on the image capturing surface to photoelectric conversion, and outputs the captured image as an image capturing signal. The image pickup signal of this output is sent to the signal processing device 5, various image signal processing is performed so that it can be displayed on the display device 6, and the endoscopic image of the subject is displayed on the display device 6. There is.

In the optical system of the stereoscopic rigid endoscope 1, the relay lens system 12 is composed of an equal-magnification afocal relay lens or the like. Here, two lens systems are shown for simplicity. Further, the pupil division prism 15 is arranged so that its apex is located at a position conjugate with the pupils of the objective lens system 11 and the relay lens system 12. A variable diaphragm 16 is disposed near the pupil division prism 15 to change the position of the passing light beam to displace the pupil or change the pupil diameter to change the distance between the centers of gravity of the pupils.

The pupil division prism 15 is not limited to the position conjugate with the pupils of the objective lens system 11 and the relay lens system 12, and may be arranged at the pupil position or in the vicinity thereof. Further, the imaging lens 13 may include a zoom lens system or the like. The variable diaphragm 16 is arranged not only in the vicinity of a position conjugate with the pupils of the objective lens system 11 and the relay lens system 12 but also in the pupil position of the objective lens system 11 and the relay lens system 12.
It may be arranged at the pupil position.

A first example of the configuration of the variable diaphragm 16 is shown in FIG. The diaphragm 21 of the first example is composed of two diaphragm plates 21a and 21b each having a circular diaphragm hole. The diaphragm plates 21a and 21b are displaced with respect to each other or one of them in a direction perpendicular to the optical axis. , The distance between the apertures is changed.

A second example of the variable diaphragm 16 is shown in FIG. A plurality of diaphragms 22 in this second example (here, six)
The diaphragm blade is configured so that the diaphragm diameter is changed by displacing the diaphragm blade.

In any of the diaphragms of the first and second examples, the distance between the centers of gravity of the two pupils to be divided can be changed by changing the distance between the diaphragm holes or the diameter of the diaphragm. it can.

Now, the distance between the centers of gravity of the two divided left and right pupils will be described. When the pupil is divided by the pupil division prism 15 to obtain two left and right images with parallax, the center-of-gravity interval is, for example, in the case of a circular pupil,
It is defined as the distance between the center of gravity position of one semicircular pupil and the position of the center of gravity of the other semicircular pupil after division. That is,
It is defined by the distance between the center of gravity positions of each pupil after division.

A factor that determines the stereoscopic effect obtained with a stereoscopic endoscope is the vergence angle of the left and right optical systems. The larger the vergence angle, the stronger the stereoscopic effect, and the smaller the vergence angle, the weaker the stereoscopic effect. . The image formed by one objective lens system
In a pupil-splitting optical system that divides into two, it is appropriate to consider that what corresponds to the optical axis that determines the vergence angle (inward angle of the left and right optical systems) is a ray that passes through the center of gravity of each divided pupil. In this case, the distance connecting the positions of the centers of gravity of these pupils is considered to be the distance between the left and right optical axes. Therefore, the stereoscopic effect changes depending on the distance between the centers of gravity of the respective pupils after the division.

In the present embodiment, the distance between the centers of gravity is changed so that the distance between the centers of gravity becomes smaller in the case of a near point and becomes larger in the case of a far point so that the distance between the centers of gravity changes. The diaphragm 16 is varied so that a constant stereoscopic effect can always be obtained regardless of the distance to the subject.

In order to realize this, the diaphragm 21 of the first example of FIG. 3 or the diaphragm 22 of the second example of FIG. 4 is used.

In the first example, two diaphragm plates 21a, 21
When one or both of b are displaced in the direction perpendicular to the optical axis, the distance between the aperture holes changes, and the left and right pupil positions move. Along with this, the distance between the centers of gravity of the pupils changes. For example,
When observing a near point, the distance between the centers of gravity of the pupils is narrowed to d1 as shown in FIG. 3 (a), and when observing a far point, as shown in FIG. Widen the center of gravity to d2. When observing the far point after observing the near point, the distance between the centers of gravity of the pupils is changed so as to expand from d1 to d2.

Further, in the second example, the diaphragm diameter is changed by the displacement of the plurality of diaphragm blades. Since the diaphragm aperture is almost circular and the left and right pupils are always divided at the center, the distance between the centers of gravity of the pupils changes according to the change in the diaphragm diameter. For example, when observing a near point, the aperture diameter is narrowed to narrow the center of gravity of the pupil as shown in FIG. 4A, and when observing a far point, FIG. As shown in, open the diaphragm diameter to widen the distance between the centers of gravity of the pupils. When observing the far point after observing the near point, the diaphragm is opened and the state is changed from (a) to (b) of FIG.

By using such a variable diaphragm 16, it is possible to change the distance between the centers of gravity of the divided left and right pupils, and it is possible to adjust the stereoscopic effect by changing the vergence angle. Therefore, when observing a far point, the angle of convergence is widened to enhance the three-dimensional effect, and when observing a near point, the angle of convergence is narrowed to reduce the three-dimensional effect.
It is possible to perform stereoscopic viewing with a constant stereoscopic effect regardless of the distance to the subject. It is also possible to adjust the stereoscopic effect by changing the distance between the centers of gravity of the left and right pupils as necessary so that a desired stereoscopic effect can be obtained at an arbitrary observation distance.

FIG. 5 is an explanatory view showing the constitution of the main part of the stereoscopic rigid endoscope according to the second embodiment of the present invention.

The second embodiment is an example in which the adjustment of the stereoscopic effect and the focusing control in the first embodiment are linked.

In the stereoscopic endoscope of the second embodiment, a variable diaphragm 31 similar to the variable diaphragm 16 of the first embodiment is arranged in the optical system behind the imaging lens 13 and near the pupil division prism 15. Focusing lenses 32 and 33 for focusing are provided on the left and right sides in the optical path after the pupil division by the pupil division prism 15. The configuration of the other optical systems is the same as that of the first embodiment, and the description is omitted.

Driving devices 34, 35 and 36 are connected to the variable diaphragm 31 and the focusing lenses 32 and 33, respectively, and these driving devices 34, 35 and 36 are connected.
Is operated by receiving an instruction input from the control means 37 for instructing the variable amount of the focus position and the variable amount of the diaphragm.

The control means 37 sets a variable amount up to the focus position according to the position of the subject, and outputs a lens drive signal for instructing the movement of the focusing lenses 32, 33 so that the focusing state is achieved. Further, in accordance with this focusing control, an aperture drive signal for driving the variable aperture 31 by a predetermined amount is output to change the distance between the centers of gravity of the left and right pupils divided according to the focal length. In this way, in conjunction with focusing control, the variable diaphragm 31 is driven according to the distance to the subject to be focused to change the distance between the centers of gravity of the left and right pupils so that the convergence angle is always constant.

For example, it is assumed that the left and right images are in focus at a point A at a certain distance, and the respective optical axes that match the left and right centroids of the entrance pupil intersect at a point A. in this case,
The left and right optical axes have parallax with a certain convergence angle, and the left and right images are stereoscopically observed. From this state, in order to stereoscopically view the object at the point B closer than the point A, it is possible to change the focal length by moving the focusing lenses 32 and 33 and bring the object at the near point into focus.

At this time, if the distance between the centers of gravity of the left and right entrance pupils is constant, the vergence angle changes, resulting in a different stereoscopic effect. In this case, the subject moves to the near point, and the stereoscopic effect becomes strong. In view of this, in the present embodiment, the variable diaphragm 31 that changes the distance between the centers of gravity of the left and right pupils and the focusing lenses 32 and 33 that perform focusing work together to make the convergence angle constant regardless of the distance to the subject. It is possible to obtain almost the same stereoscopic effect from the far point to the near point.

As described above, according to this embodiment, it is possible to perform stereoscopic vision by focusing on a desired distance without changing the stereoscopic effect of the obtained image. It is also possible to adjust the vergence angle so that a desired stereoscopic effect can be obtained at a certain predetermined distance after focusing.

FIGS. 6 to 8 relate to a third embodiment of the present invention, FIG. 6 is an explanatory view showing the structure of the main part of a stereoscopic rigid endoscope, and FIG. 7 is a diagram showing light passing from a pupil division prism through a variable diaphragm. FIG. 8 is a perspective view showing a schematic configuration of a variable diaphragm.

The third embodiment is an example in which variable diaphragms are arranged in the optical paths after pupil division by the pupil division prism.

In the stereoscopic endoscope according to the second embodiment, variable diaphragms 39 and 40 are provided on the left and right sides of the optical path after pupil division by the pupil division prism 15 in the optical system. The other structure is the same as that of the second embodiment, and the description thereof is omitted.

As shown in FIGS. 7 and 8, the variable diaphragms 39 and 40 are composed of diaphragm plates each having a diaphragm hole. When the diaphragms are displaced, the diaphragm holes are moved and the position of the pupil is displaced. It is like this. The variable diaphragms 39 and 40 allow, for example, a light beam in a shaded portion in FIG. 7 to pass therethrough, and when the variable diaphragms 39 and 40 move, the positions of the pupils are displaced and the distance between the centers of gravity of the left and right pupils is changed. .
At this time, as shown in FIG. 8, the variable diaphragms 39 and 40 are connected to each other or the driving portions are interlocked with each other, and the two diaphragm plates are configured to move in conjunction with each other.

When the variable diaphragms 39 and 40 are moved to the front side with respect to the optical axis of the optical system before the pupil division, the distance between the left and right pupils, that is, the distance between the centers of gravity of the pupils is narrowed, and the stereoscopic effect of the obtained image is weakened. Become. On the other hand, when the variable diaphragms 39 and 40 are moved rearward with respect to the optical axis of the optical system before the pupil division, the distance between the left and right pupils becomes wide, and the stereoscopic effect of the obtained image becomes strong. At this time, as in the second embodiment, the variable diaphragms 39 and 40 and the focusing lenses 32 and 33 are linked.

As described above, even when the variable diaphragm is arranged in the optical path after pupil division, the distance between the centers of gravity of the left and right pupils can be adjusted as in the first and second embodiments, regardless of the distance to the subject. It is possible to perform stereoscopic vision so that a constant stereoscopic effect is always obtained.

FIG. 9 is an explanatory view showing the structure of the main part of a stereoscopic rigid endoscope according to the fourth embodiment of the present invention.

The fourth embodiment is an example in which a distance detecting means for detecting the distance to the object is provided and the variable diaphragm and the focusing lens are controlled according to the detected distance.

In the stereoscopic endoscope of the fourth embodiment, the focusing lens 41 is provided behind the imaging lens 13 in the optical system.
Is disposed, and the variable diaphragm 42 is provided near the pupil division prism 15.
Are arranged. The configuration of the other optical systems is the same as that of the first embodiment, and the description is omitted. As the variable diaphragm 42, for example, the diaphragm 22 for varying the diaphragm diameter of the second example in the first embodiment is used.

Driving devices 43 and 44 are connected to the focusing lens 41 and the variable diaphragm 42, respectively, and these driving devices 43 and 44 are provided for the signal processing device 5 so that the focus position is variable and the diaphragm is variable. It operates so as to receive an instruction input from the control means 45 for instructing a variable amount. Further, the signal processing device 5 is provided with a brightness detecting means 46, and the solid-state image pickup devices 19 and 20.
The brightness of the image is detected based on the output from the. Further, the control means 45 and the brightness detection means 46 constitute an automatic light control means for adjusting the light quantity of the light source device 47.

At the time of observation with an endoscope, the observation site is irradiated with illumination light for observation, and the brightness of the image changes depending on the distance to the subject due to this illumination. For this reason, the automatic light control unit detects the brightness of the image and controls the light amount of the light source device so that a constant brightness is obtained. You can know the distance. That is, the image becomes bright when the subject is at a short distance and dark at a long distance, so that the distance to the subject can be detected from the brightness of the image.

In this embodiment, the brightness of the image is detected by the brightness detecting means 46, and the distance to the object is detected by the control means 45. Here, the reflectance of the object, the brightness of the image corresponding to the illumination light amount of the light source device 47,
Also, it is assumed that the distance to the subject corresponding thereto is known in advance and stored in a memory or the like.

The brightness detecting means 46 is the solid-state image pickup device 1.
The brightness of the image is detected by an integrating means or the like that integrates the output image signals from 9, 20, and the brightness detection signal is controlled by the controlling means 4.
Output to 5. The control unit 45 detects the distance to the subject based on the brightness detection signal, determines the amount of movement of the focusing lens 41 and the amount of change of the variable diaphragm 42 that is linked to the movement amount of the focusing lens 41 in accordance with the distance, and drives the driving devices 43, The drive signal is output to 44. As a result, similarly to the second embodiment, focusing control is performed according to the distance to the subject, and the distance between the centers of gravity of the left and right pupils is adjusted in association with this to adjust the stereoscopic effect.

Since the relationship between the object distance and the size of the vergence angle is predetermined by the optical system, the moving amount of the focusing lens 41 and the changing amount of the variable diaphragm 42 linked with this are stored in a memory or the like. It can be controlled to interlock every time.

Further, when observing the near point, the variable diaphragm 42 which can change the diaphragm diameter in order to narrow the distance between the centers of gravity of the left and right pupils.
By narrowing the aperture, the brightness of the image can be suppressed by reducing the aperture diameter. That is, it becomes possible to perform the adjustment of the stereoscopic effect and the adjustment of the brightness of the image in conjunction with each other. In accordance with the displacement of the variable diaphragm 42, the control means 45 outputs a light amount adjustment signal to the light source device 47 to adjust the light amount of the light source.

As described above, according to this embodiment, automatic light control, focusing control, and stereoscopic effect adjustment can be performed in conjunction with each other. Further, by narrowing the diaphragm diameter by the variable diaphragm 42 at the time of near-point observation, it is possible to observe a deep depth of field, which was conventionally an image having a shallow depth of field.

The relay optical system of this embodiment is not limited to the one having a single optical axis, but the transmitted image may be divided on the way,
It may be configured such that each of the divided images is transmitted. Further, an image forming lens, a zoom lens, etc. may be optionally provided in the optical system.

[0054]

As described above, according to the present invention, it is possible to adjust the stereoscopic effect of the obtained image, if necessary.
There is an effect that stereoscopic viewing can be performed with a desired stereoscopic effect regardless of the distance to the subject.

[Brief description of drawings]

FIG. 1 to FIG. 4 relate to a first embodiment of the present invention, and FIG. 1 is an explanatory view showing a configuration of a main part of a stereoscopic rigid endoscope.

FIG. 2 is an explanatory diagram showing an external configuration of a stereoscopic rigid endoscope.

FIG. 3 is an explanatory diagram showing a first configuration example of a variable aperture.

FIG. 4 is an explanatory diagram showing a second configuration example of a variable aperture.

FIG. 5 is an explanatory diagram showing a configuration of a main part of a stereoscopic rigid endoscope according to a second embodiment of the present invention.

6 to 8 relate to a third embodiment of the present invention,
FIG. 6 is an explanatory diagram showing a configuration of a main part of a stereoscopic rigid endoscope.

FIG. 7 is an explanatory diagram showing light passing through a variable diaphragm from a pupil division prism.

FIG. 8 is a perspective view showing a schematic configuration of a variable diaphragm.

FIG. 9 is an explanatory diagram showing a configuration of a main part of a stereoscopic rigid endoscope according to a fourth embodiment of the present invention.

FIG. 10 is an explanatory diagram showing a configuration example of a conventional stereoscopic endoscope.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Stereoscopic rigid endoscope 11 ... Objective lens system 12 ... Relay lens system 13 ... Imaging lens 14 ... Focusing lens 15 ... Pupil division prism 16 ... Variable diaphragm 19, 20 ... Solid-state image sensor

Claims (3)

[Claims] 1. An objective lens system having a single optical axis, and at least one relay lens system arranged coaxially with the objective lens system for transmitting an object image formed by the objective lens system. A pupil position of the relay lens system or the vicinity thereof, or a conjugate position thereof is arranged, and a pupil division unit that divides the pupil into a plurality, and a pupil division unit is arranged near the pupil division unit or a conjugate position thereof.
A pupil-spacing conversion unit that changes the center-of-gravity interval of the plurality of pupils; an image-forming optical system that receives a light beam emitted from the relay lens system and cooperates with the pupil-splitting unit to form a plurality of object images; A stereoscopic rigid endoscope, comprising: an image pickup unit that receives each of the object images. 2. The stereoscopic rigid endoscope according to claim 1, further comprising a focusing lens arranged in front of the pupil dividing means. 3. The image forming optical system includes a focusing lens movable along an optical axis, and movement of the focusing lens and change of a center-of-gravity interval of a plurality of pupils formed by the pupil-spacing conversion means. The stereoscopic rigid endoscope according to claim 1, wherein and are linked.