GB2040064A

GB2040064A - Improvements in or relating to endoscopes including an articulated optical system

Info

Publication number: GB2040064A
Application number: GB7940174A
Authority: GB
Original assignee: Richard Wolf GmbH
Current assignee: Richard Wolf GmbH
Priority date: 1978-11-27
Filing date: 1979-11-21
Publication date: 1980-08-20
Also published as: FR2442039A1; DE2851251A1

Abstract

An endoscope is fitted with an additional observation tube, which is twistable with respect to the endoscope, a beam splitter the optical path of the endoscope transmitting an image to an articulated optical system connected to the observation tube, with the articulated optical system consisting of tubes R1, R2, R3, (R4) and (R5) in parallel planes and containing optical elements and joints which consist of two joint caps, extending at right angles to the tubes, with reflector means S, P mounted in the caps, the articulated optical system proximally terminating in a tube comprising a reversing prism UP and an ocular lens OK. The tubes R1-R5 are geared together as shown and the net result is that the image presented at OK remains the correct way up despite movement in the articulated tube. <IMAGE>

Description

SPECIFICATION Improvements in or relating to endoscopes including an articulated optical system The present invention relates to endoscopes incorporating a beam splitter and including articulated optical system connected thereto.

Endoscopes comprising a beam splitter and an articulated optical system connected thereto are eliciting ever increasing interest for observation and examination of an object within body cavities, since a section of a body cavity detected by the optical system of the endoscope may be viewed and examined direct not only by the doctor but also by a co-observer.

Due to the actuation of the joints of the articulated optical system, the image available to the observer is turned sideways or upside-down, i.e. an image reversal occurs, so that the co-observer is frequently unable to see which image section is situated at the top, side or bottom. To circumvent this, mechanical, optical or electrical markings have hitherto been provided, it being necessary to place these markings in coincidence to enable the co-observer to detect which section of the image is truly uppermost.

It is an object of the invention to ensure that a correctly oriented picture is always available to the co-observer, i.e. that the image is automatically turned right side up for the observer, without his having to place any markings in coincidence.

Accordingly the invention consists in an endoscope of the kind comprising an observation tube which is twistable with respect to the endoscope a beam splitter in said observation tube, an articulated optical system connected to said observation tube, said articulated optical system consisting of tubes in parallel planes and containing optical elements and joints which consist of two joint caps, extending at right angles to said tubes, with reflector means mounted in said caps, said articulated optical system proximally terminating in a tube comprising a reversing prism and an ocular lens, wherein said joint caps containing said reflectors, are turnable to cause image reversal in said articulated optical system, resulting in mechanical turning of the following tubes of said articulated optical system, and the image reversal in each said joint being cancelled by a correspondingly turned reversing prism in each instance or merely by a reversing prism contained in said ocular tube.

Due to this construction, the co-observer is given the opportunity of observng an upright picture at all times, notwithstanding how and how farthe joint caps are turned with respect to the articulated tubes containing the optical lenses, or the articulated tubes are turned with respect to each other.

In order that the invention may be more clearly understood, reference will now be made to the accompanying drawings, which show two embodiments thereof by way of example and in which: Figure 1 shows an endoscope comprising a known articulated optical system, with indication of the reflectors situated within the joint heads, in diagrammatical sideview, Figure 2 shows an enlarged view of an articulated optical system connected to an endoscope in a first embodiment of the invention in diagrammatical longitudinal cross-section, with a part of the articulated optical system removed, and Figure 3 shows an enlarged part view of an articulated optical system of a second embodiment of the invention in diagrammatical longitudinal cross-section and part of the articulated optical system removed.

Referring now to drawings Figure 1 shows a known endoscope fitted with a rotatable observation tube BS containing a beam splitter St, to which is rigidly connected the first tube R1 of an articulated optical system containing optical elements, which tube is then followed by four joints comprising the joint caps or terminations A - B, C - D, E - F and G - H for interconnecting the optical tubes R2, R3, R4 and RSwhich contain lenses which are not illustrated and which lie in parallel planes. Each joint cap has installed in it a reflector means such as a deflector prism P or mirror S which reflector means beam the image of an object of a body cavity picked up by the endoscope and intended to be observed direct by the doctor, to a co-observer via the beam splitter St.

and the tubes R and finally via the reversing prism UP to the ocular OK.

The joint caps A to H, together with the reflectors P or S co-ordinated with them, may be turned with respect to each other at the extremities of the tubes R and within each joint around the joint axis extending at right angles to the tubes.

In a particular adjusted position of the articulated optical system, an upright image of the object of a body cavity also becomes visible to the co-observer.

As soon as a turning displacement of the joint caps A to H and a pivotal displacement of the optical tubes R in parallel planes are required for the co-observer however, an image reversal occurs in the case of a known instrument according to Figure 1.

In order that this image reversal may be prevented or corrected so that an upright image always appears to the co-observer, the articulated optical system corresponding to the embodiment of Figure 2 in accordance with the invention is constructed in the following manner.

The first optical tube R1 which is pivotable together with the beam splitter St, rigidly and precisely installed in it, around the axis of the endoscope E, is fitted at its free end and within the joint cap A which is rotatable with respect to the tube R1 by means of a peripheral denticulation Z1 which engages in a peripheral denticulation Z2 at one extremity of a hollow shaft HW1,that is to say with a transmission ratio of 1 :1. The other extremity of the hollow shaft HW1 is in engagement via a peripheral denticulation Z3 with a peripheral denticulation Z4 of the second tube R2 of the articulated optical system, also with a transmission ratio of 1:1.

This structure of the first joint A-B is repeated for the other joints D-C, E-F between the tubes R2-R3, R3-R4. The final joint G-H between the tubes R4 and R5 is constructed in practically the same manner, but in this case, the transmission ratio between the denticulation ZX and the denticulation ZY of the final tube R5 is equal to 1:2. In known manner, a reversing prism UP is installed in the final tube R5 before the proximal ocular section OK which may however be turned with respect to the tube R5, so that for example upon coupling a camera, the pivoting and turning of the tube R5 are not impeded.

After calibration in a particular position of the articulated optical system, the reflectors S or P are secured in the articulated optical system. The peripheral denticulations Z are generally gearwheels, and preferably, bevel gears.

In the constructin of a somewhat more complex design according to Figure 3, the peripheral denticulation Z1 on the extremity of the first tube R1 of the articulated optical system is in engagement with the peripheral denticulation Z2 of a mounting F1 for a reversing prism UP, but then in the transmission ratio of 1:2. The joint cap A or its casing, is rigidly connected to a tube stub parallel to the joint axis, said tube stub at the free extremity being in engagement via a peripheral denticulation Z3 in a peripheral denticulation Z4 of a mounting F2 rotatably housed in the second tube R2 and comprising a reversing prism UP, equally with the transmission ratio 1:2.

This structure of the first joint A-B in combination with the tubes R1 and R2 of the articulated system is repeated for all the joints D-D, E-F and G-H, the rotatable ocular section OK again being connected to the final tube R5.

The image reversal is cancelled automatically in both embodiments by rotary displacement of the joint caps or terminations with respect to each other and under pivotal displacement of the articulated tubes, so that an upright image is always passed to the co-observer.

Although use has been made of the term "coobserver" in the foregoing, such a person may be replaced by a film or television camera.

Claims

1. An endoscope comprising an observation tube which is twistable with respect to the endoscope and having a beam splitter therein, an articulated optical system connected to the observation tube, which articulated optical system consists of tubes in parallel planes and containing optical elements and joints which consist of two joint caps, extending at right angles to the tubes, with reflector means mounted in the caps, the articulated optical system proximally terminating in a tube comprising a reversing prism and an ocular lens, wherein the joint caps containing the reflectors, are turnable to cause image reversal in the articulated optical sytem, resulting in mechanical turning of the foilowing tubes of the articulated optical system, and the image reversal in each said joint is cancellable by a correspondingly turned reversing prism in each instance, or a reversing prism contained in the ocular tube.

2. An endoscope as claimed in claim 1, wherein a first one of said tubes is rigidly connected to the beam splitter and engages within a first joint cap of the first joint by means of a peripheral denticulation with a ration 1:1 in a peripheral denticulation on one extremity of a tubular section, at whose other extremity and within said second joint cap a peripheral denticulation engages in a peripheral denticulation of the second parallel tube, also having a transmission ratio of 1:1, and these denticulations and transmission ratios are repeated in all joints, whereas the last peripheral denticulation of the tubular section of the final joint cap is in engagement with a transmission ratio of 1:2 with the peripheral denticulation of the last tube containing a reversing prism and the ocular.

3. An endoscope as claimed in claim 1, wherein the first tube rigidly connected to the beam splitter is engaged within its joint cap by means of a peripheral denticulation and with a ratio of 1:2 in a denticulation of a lens mounting containing a reversing prism, the joint cap engaging in the second joint cap via a peripheral denticulation with a ratio of 1:2 in a peripheral denticulation of a lens mounting which is freely rotatable in the second tube and contains a reversing prism, and these denticulated connections are repeated in the joints between the second and third tubes, from the third to fourth tubes and so on up to the final oculartube.

4. An endoscope as claimed in claim 1, wherein the denticulations of the parallel tubes, of the joint caps and of the mounting containing reversing prisms, consist of bevel gears.

5. An endoscope substantially as hereinbefore described with reference to Figures 1 and 2 of the accompanying drawings.

6. An endoscope substantially as hereinbefore described with reference to Figures 1 and 3 of the accompanying drawings.