JP3283084B2 - Stereoscopic rigid endoscope - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rigid stereoscopic endoscope which allows a part to be observed to be observed three-dimensionally.

[0002]

2. Description of the Related Art An endoscope apparatus has been widely used in which an elongated insertion portion can be inserted into a body cavity or the like so as to observe a test site that cannot be directly viewed. With a normal endoscope, it is difficult to observe a test site only as a flat surface without perspective, so it is difficult to observe, for example, minute irregularities on the surface of a body cavity wall. There was a problem that various treatments could not be easily performed.

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

[0004] As such a stereoscopic endoscope apparatus, for example, Japanese Patent Application Laid-Open No. 57-69839 and the like include a pair of image transmission optical systems provided inside an insertion portion of an endoscope. A pair of objective optical systems were provided on the distal end side of the camera, and a pair of eyepiece optical systems were provided on the hand operation unit side, so that the convergence angle formed by the pair of objective optical systems was adjusted so that the observation site could be viewed three-dimensionally. A device has been proposed.

FIG. 10 shows a schematic configuration of a conventional stereoscopic endoscope. The stereoscopic endoscope 51 includes two objective lens systems 52a and 52b and relay lens systems 53a and 53b for transmitting an image formed by the objective lens systems 52a and 52b at the distal end of the elongated insertion portion. Each image is picked up by a solid-state image sensor 54a, 54b such as a CCD.

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

[0007] For example, when using a stereoscopic endoscope in a surgical operation, the operator can observe the test site with almost the same three-dimensional effect when observing the site near and far away, so that the operator can feel the same feeling. There is a request to perform a procedure. However, the stereoscopic endoscope as described above cannot satisfy such a demand because the stereoscopic effect is large at the near point and the stereoscopic effect is small at the far point.

[0008]

As described above, in the conventional stereoscopic endoscope, the angle of convergence changes depending on the distance to the subject, and the stereoscopic effect of the obtained image changes. There was a problem that it was not possible.

Conversely, there is also a demand for observing in a three-dimensional state that is easy to see according to the respective objects at the far point and the near point. However, it is necessary to perform adjustment so as to obtain a desired three-dimensional effect at a certain object distance. Was also difficult.

The present invention has been made in view of these circumstances, and can adjust the stereoscopic effect of an obtained image as needed, so that stereoscopic vision can be achieved with a desired stereoscopic effect regardless of the distance to the subject. An object of the present invention is to provide a stereoscopic rigid endoscope capable of performing the operation.

[0011]

SUMMARY OF THE INVENTION A stereoscopic rigid endoscope according to the present invention includes an objective lens system having a single optical axis, and is arranged coaxially with the objective lens system and formed by the objective lens system. At least one relay lens system for transmitting an object image, a pupil position of the relay lens system or at or near the pupil position, or a conjugate position thereof, and pupil division means for dividing the pupil into a plurality; A pupil interval conversion unit arranged near the unit or at a conjugate position thereof, for changing a center of gravity of the plurality of pupils, receiving a light beam emitted from the relay lens system, and cooperating with the pupil division unit to form a plurality of pupil division units; The apparatus comprises an imaging optical system for forming an object image, and imaging means for receiving each of the object images.

[0012]

The pupil interval conversion means changes the center of gravity interval of a plurality of pupils divided by the pupil division means to change the convergence 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 view showing a configuration of a main part of a stereoscopic rigid endoscope, and FIG. 2 is an explanatory view showing an external configuration of the stereoscopic rigid endoscope. FIGS. 3 and 3 are explanatory diagrams 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, the stereoscopic rigid endoscope 1
(Hereinafter, simply referred to as an endoscope) has an elongated and hard insertion portion 2, and a grip portion 3 is continuously provided at a base end portion of the insertion portion 2. A cable 4 extends from the grip portion 3, and the rigid stereoscopic 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, and two left and right 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 endoscope image. It has become. For example, by displaying the left and right images alternately on the display device 6 and observing the images with polarized glasses,
A subject image having a three-dimensional effect can be observed.

A main part including an optical system and the like of the rigid stereoscopic endoscope 1 is configured as shown in FIG. One objective lens system 11 is provided at the distal end of the endoscope 1, and a relay lens system 12 for transmitting a subject image formed by the objective lens system 11 is provided coaxially 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, and a pupil splitting prism 15 is disposed at a position conjugate with the pupils of the objective lens system 11 and the relay lens system 12 behind the focusing lens 14. That is, the image formed by the objective lens system 11 having a single optical axis is transferred to the relay lens system 12.
, And the pupil is split by the pupil splitting prism 15 so as to form two left and right images.

In the optical path near the pupil splitting prism 15,
A variable stop 16 is provided as pupil interval conversion means for changing the center of gravity of the pupil. And the pupil splitting prism 15
1 that reflects the light beams split by the mirror 1
7 and 18 are provided, and solid-state imaging devices 19 and 20 such as CCDs are provided at image forming positions of the image forming lens 13 behind the mirrors 17 and 18, respectively. Solid-state imaging device 19, 2
Numeral 0 captures an image by subjecting the subject image formed on the imaging surface to photoelectric conversion, and outputs the captured image as an imaging signal. The output imaging signal is sent to the signal processing device 5, where various image signal processing is performed so that the image signal can be displayed on the display device 6, and the endoscope image of the subject is displayed on the display device 6. I have.

In the optical system of the stereoscopic rigid endoscope 1, the relay lens system 12 is composed of an equal-magnification afocal relay lens and the like, and is shown here with two lens systems for simplicity. The pupil splitting prism 15 is disposed so that the vertex is located at a position conjugate with the pupils of the objective lens system 11 and the relay lens system 12. In the vicinity of the pupil splitting prism 15, a variable stop 16 for changing the distance between the centers of gravity of the pupils by displacing the pupil by changing the position of the passing light beam or changing the pupil diameter is arranged.

The pupil splitting prism 15 is not limited to a position conjugate with the pupils of the objective lens system 11 and the relay lens system 12, but 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. Further, the variable stop 16 is provided not only in the vicinity of a position conjugate with the pupil 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.
May be arranged at the position of the pupil.

FIG. 3 shows a first example of the configuration of the variable stop 16. The diaphragm 21 of the first example is composed of two diaphragm plates 21a and 21b each having a circular diaphragm hole, and the diaphragm plates 21a and 21b are displaced in a direction perpendicular to the optical axis or to one another. The distance between the apertures is changed.

FIG. 4 shows a second example of the variable stop 16. The number of apertures 22 in the second example is plural (here, six).
The aperture diameter is changed by displacing the aperture blade.

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

Here, the center-of-gravity interval between the divided left and right pupils will be described. In a case where the pupil is divided by the pupil dividing prism 15 and two images having parallax are obtained, the center-of-gravity interval is, for example, a circular pupil.
It is defined by the distance between the center of gravity of one semicircular pupil after division and the center of gravity of the other semicircular pupil. That is,
It is defined by the interval between the positions of the centers of gravity of the respective pupils after division.

The factors that determine the stereoscopic effect obtained by the stereoscopic endoscope include the convergence angles of the left and right optical systems. The larger the convergence angle, the stronger the stereoscopic effect, and the smaller the convergence angle, the weaker the stereoscopic effect. . The image formed by one objective lens system is
In the pupil division optical system that divides the pupil into two, it is appropriate to consider an optical axis that determines the convergence angle (the inward angle of the left and right optical systems) as a light beam that passes through the position of the center of gravity of each of the divided pupils. In this case, the distance connecting the positions of the centers of gravity of these pupils is considered to be the interval between the left and right optical axes. Therefore, the stereoscopic effect changes according to the center of gravity interval of each pupil after division.

In this embodiment, the distance between the centers of gravity is variable in the direction of decreasing the distance between the centers of gravity in the case of the near point and in the direction of increasing the distance of the centers of gravity in the case of the far point so that the distance between the centers of gravity changes in accordance with the distance to the subject. The aperture 16 is varied so that a constant stereoscopic effect is always obtained regardless of the distance to the subject.

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

In the first example, two aperture plates 21a, 21
When one or both of b is displaced in a direction perpendicular to the optical axis, the distance between the apertures changes, and the left and right pupil positions move. Along with this, the center of gravity of the pupil changes. For example,
When observing the near point, the distance between the centers of gravity of the pupils is reduced to d1 as shown in FIG. 3A, and when observing the far point, the pupil of the pupil is observed as shown in FIG. The distance between the centers of gravity is increased to d2. When observing the far point after observing the near point, the center of gravity of the pupil is changed so as to increase from d1 to d2.

In the second example, the diaphragm diameter changes due to the displacement of the plurality of diaphragm blades. Since the aperture opening is substantially 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 aperture diameter. For example, when observing the near point, as shown in FIG. 4A, the aperture diameter is reduced to narrow the center of gravity of the pupil, and when observing the far point, FIG. The aperture diameter is widened to widen the center of gravity of the pupil as shown in FIG. When observing the far point after observing the near point, the stop is opened and the state is changed from (a) to (b) in FIG.

By using such a variable stop 16, the distance between the centers of gravity of the divided left and right pupils can be changed, and the stereoscopic effect can be adjusted by changing the angle of convergence. Therefore, at the far point observation, the convergence angle is widened to enhance the stereoscopic effect, and at the near point observation, the convergence angle is narrowed to reduce the stereoscopic effect,
Regardless of the distance to the subject, stereoscopic viewing can always be performed with a constant stereoscopic effect. In addition, it is also possible to change the center of gravity of the left and right pupils and adjust the three-dimensional effect as needed so that a desired three-dimensional effect can be obtained at an arbitrary observation distance.

FIG. 5 is an explanatory view showing a configuration of a main part of a stereoscopic rigid endoscope according to a 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 stop 31 similar to the variable stop 16 of the first embodiment is disposed in the optical system behind the imaging lens 13 and near the pupil splitting prism 15. Focusing lenses 32 and 33 for focusing on the optical path after the pupil division by the pupil division prism 15 are disposed on the left and right sides, respectively. The other configuration of the optical system is the same as that of the first embodiment, and the description is omitted.

The variable diaphragm 31 and the focusing lenses 32, 33 are provided with driving devices 34, 35, 36, respectively, and these driving devices 34, 35, 36 are connected to each other.
Operates in response to an instruction input from the control means 37 for instructing the variable amount of the focus position and the variable amount of the aperture.

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

For example, it is assumed that the focus of the left and right images coincides with a point A at a certain distance, and the respective optical axes coincident with the left and right centroids of the entrance pupil intersect at the point A. in this case,
The left and right optical axes have parallax at 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 to the point A, it is possible to change the focal length by moving the focusing lenses 32 and 33 to bring the near object into focus.

At this time, if the distance between the centers of gravity of the left and right entrance pupils is constant, the convergence angle changes, resulting in a different stereoscopic effect. In this case, the three-dimensional effect is enhanced because the subject has moved to the near point. Therefore, in the present embodiment, the convergence angle is made constant regardless of the distance to the subject by interlocking the variable aperture 31 that changes the center of gravity between the left and right pupils and the focusing lenses 32 and 33 that perform focusing. Thus, almost the same stereoscopic effect can be obtained from the far point to the near point.

As described above, according to the present embodiment, it is possible to perform stereoscopic vision by focusing on a desired distance without changing the stereoscopic effect of the obtained image. Further, it is also possible to adjust the convergence angle so that a desired three-dimensional effect can be obtained at a predetermined distance where focusing has been performed.

FIGS. 6 to 8 relate to a third embodiment of the present invention. FIG. 6 is an explanatory view showing a configuration of a main part of a stereoscopic rigid endoscope. FIG. FIG. 8 is a perspective view showing a schematic configuration of a variable stop.

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

In the stereoscopic endoscope according to the third embodiment, variable apertures 39 and 40 are disposed 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 configuration is the same as that of the second embodiment, and the description is omitted.

As shown in FIGS. 7 and 8, the variable diaphragms 39 and 40 are each formed of a diaphragm plate having a diaphragm hole, and the diaphragm hole is moved by displacement, thereby displacing the position of the pupil. It has become. For example, light fluxes indicated by oblique lines in FIG. 7 pass through the variable diaphragms 39 and 40, and when the variable diaphragms 39 and 40 move, the position of the pupil is displaced, and the center of gravity between the left and right pupils changes. .
At this time, as shown in FIG. 8, the variable apertures 39 and 40 are connected to each other or the drive unit is interlocked, and the two aperture plates are configured to move together.

When the variable diaphragms 39 and 40 are moved forward with respect to the optical axis of the optical system before pupil division, the distance between the left and right pupils, that is, the distance between the centers of gravity of the pupils becomes narrow, and the three-dimensional 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 is increased, and the stereoscopic effect of the obtained image is enhanced. 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 aperture is arranged in the optical path after the pupil division, the center of gravity of the left and right pupils can be adjusted similarly to the first and second embodiments, regardless of the distance to the subject. It is possible to perform stereoscopic viewing so that a constant stereoscopic effect is always obtained.

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

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

The stereoscopic endoscope according to the fourth embodiment includes a focusing lens 41 behind the imaging lens 13 in the optical system.
Is provided, and a variable stop 42 is provided near the pupil splitting prism 15.
Is arranged. The other configuration of the optical system is the same as that of the first embodiment, and the description is omitted. As the variable stop 42, for example, the stop 22 that changes the stop diameter in the second example of the first embodiment is used.

Driving devices 43 and 44 are connected to the focusing lens 41 and the variable diaphragm 42, respectively. These driving devices 43 and 44 are provided with a variable amount of focus position and a diaphragm provided in the signal processing device 5. It operates in response to an instruction input from the control means 45 for instructing the variable amount. Further, the signal processing device 5 is provided with a brightness detecting means 46, and the solid-state imaging devices 19 and 20 are provided.
The brightness of the image is detected on the basis of the output from. 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 to perform observation, and the brightness of the image changes depending on the distance to the subject due to the illumination. For this reason, the light intensity of the light source device is controlled by the automatic light control means so that the brightness of the image is detected and a constant brightness is obtained. You can know the distance of. That is, if the subject is at a short distance, the image becomes bright, and if the subject is at a long distance, the image becomes dark. Therefore, the distance to the subject can be detected from the brightness of the image.

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

The brightness detecting means 46 includes the solid-state image sensor 1
The brightness of the image is detected by an integrating means or the like for integrating the output image signals from the image processing units 9 and 20, and the brightness detection signal is output to the control means 4.
Output to 5 The control means 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 aperture 42 associated therewith in accordance with the distance, and A drive signal is output to 44. As a result, similarly to the second embodiment, focusing control according to the distance to the subject and adjustment of the center of gravity of the left and right pupils in conjunction with this control are performed, and the stereoscopic effect is adjusted.

Since the relationship between the object distance and the size of the convergence angle is determined in advance by the optical system, the amount of movement of the focusing lens 41 and the amount of change of the variable aperture 42 associated therewith are stored in a memory or the like. And can be controlled to work together.

Also, when observing the near point, a variable aperture 42 capable of changing the aperture diameter in order to reduce the distance between the centers of gravity of the left and right pupils.
When the aperture is reduced, the brightness of the image can be suppressed by reducing the aperture diameter. That is, the adjustment of the stereoscopic effect and the adjustment of the brightness of the image can be performed in conjunction with each other. The controller 45 outputs a light amount adjustment signal to the light source device 47 in accordance with the displacement of the variable stop 42 to adjust the light amount of the light source.

As described above, according to this embodiment, the automatic light control, the focusing control, and the adjustment of the three-dimensional effect can be performed in an interlocked manner. Furthermore, by narrowing the aperture diameter by the variable aperture 42 at the time of near point observation, it is possible to observe the depth of field deeply in an image which was conventionally a shallow depth of field.

The relay optical system according to the present embodiment is not limited to one having a single optical axis, but splits a transmitted image halfway,
Further, it may be configured to transmit the divided images. Further, an image forming lens, a zoom lens, and the like may be arbitrarily provided in the optical system.

[0054]

As described above, according to the present invention, the stereoscopic effect of the obtained image can be adjusted as required.
There is an effect that stereoscopic vision can be performed with a desired stereoscopic effect regardless of the distance to the subject.

[Brief description of the drawings]

FIG. 1 to FIG. 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.

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 stop.

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

FIG. 6 to FIG. 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 stop from a pupil division prism.

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

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 splitting prism 16 ... Variable aperture 19, 20 ... Solid-state image sensor

Claims (8)

(57) [Claims] An objective lens system having a single optical axis; at least one relay lens system disposed 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 its vicinity, or a conjugate position thereof, and a pupil dividing unit that divides the pupil into a plurality, and is disposed near the pupil dividing unit or a conjugate position thereof,
A pupil interval conversion unit that changes a center of gravity interval of the plurality of pupils, an imaging optical system that receives a light beam emitted from the relay lens system and cooperates with the pupil division unit to form a plurality of object images, An imaging means for receiving each of the object images; 2. A stereoscopic rigid endoscope according to claim 1, wherein a focusing lens is arranged before said pupil dividing means. 3. The imaging optical system includes a focusing lens movable along an optical axis, and the movement of the focusing lens and the change of the center of gravity of a plurality of pupils divided and formed by the pupil interval conversion unit. The stereoscopic rigid endoscope according to claim 1, wherein the endoscope is linked with the stereoscopic rigid endoscope. 4. The pupil distance conversion means includes:
And two diaphragm plates, and the two diaphragm plates are
Or one of them is displaced in the direction perpendicular to the optical axis,
Changing the distance and changing the center of gravity between the two pupils
The stereoscopic rigid endoscope according to claim 1, characterized in that: 5. The pupil distance conversion means includes a plurality of aperture blades.
And displacing the plurality of aperture blades to reduce the aperture.
Changing the diameter of the pupil and the distance between the centers of gravity of the two pupils
The stereoscopic rigid endoscope according to claim 1, characterized in that: 6. When observing the near point, the distance between the centers of gravity of the pupils is reduced.
When observing a distant point, be sure to increase the distance between the pupils' centers of gravity.
The three-dimensional object according to any one of claims 1 to 5, characterized in that:
A rigid endoscope. 7. When observing the near point, reduce the aperture diameter.
Reduce the distance between the centers of gravity of the pupils, and open the aperture when observing the far point.
And widening the distance between the centers of gravity of the pupils.
The stereoscopic rigid endoscope according to the above. 8. A brightness detecting means, comprising: a brightness detecting means.
Focusing based on the brightness detection signal output by the stage
Control and the control of the pupil interval conversion means interlocked therewith.
The stereoscopic rigidity according to claim 3, wherein the control is performed.
Endoscope.