Endoscope having provision for repositioning a video sensor to a location which does not provide the same cross-sectionally viewed relationship with the distal end

An endoscope has a video device arranged at the distal end of the endoscope shaft. The video device is connected by means of a transmission system to a supply unit arranged at the proximal end of the endoscope shaft. The video device is provided with a lens for imaging an object field and an illumination unit. The lens and the image recorder are combined into a video unit which is held in such a movable manner at the endoscope shaft that the outer contour of the cross-section of the video unit lays essentially within the outer contour of the cross-section of the distal end of the endoscope shaft when being introduced into the cavity to be examined. After termination of the introduction procedure, the video unit can be moved in relation to the distal end of the endoscopic shaft beyond the outer contour of the cross-section and/or longitudinal section.

BACKGROUND AND SUMMARY OF THE INVENTION 
The present invention relates to an endoscope with a video device, which is 
arranged at the distal end of an endoscope shaft and is connected by means 
of a transmission system to a supply unit arranged at the proximal end 
thereof and is provided with a lens, which images an object field 
illuminated by an illumination unit onto an image recorder. 
Endoscopes serve to inspect cavities for the purpose of examination and/or 
manipulation and have found a great number of applications in technology 
and medicine. 
Conventional endoscope have a so called image forwarder arranged at the 
distal end, which "forwards" the image produced by the lens from the 
distal end to the proximal end, where it is examined by means of an 
eyepiece. In "rigid" endoscopes, the image forwarder is composed of 
so-called relay lens sets and in flexible endoscopes of fiber bundles. 
Small-sized video image recorders, as by way of illustration CCD chips, 
have been available for some time. For this reason, it has often been 
proposed instead of using an image forwarder, to provide an image recorder 
in the image plane of the lens at the distal end, which is connected via a 
transmission system to a supply unit provided at the proximal end. See for 
example U.S. Pat. Nos. 4,253,447 and 4,261,344, in which an "upright" 
semiconductor image recorder, i.e. an image recorder standing at a 
90.degree. angle to the axis of the endoscope, is arranged in the image 
plane of the lens provided at the distal end. 
With this kind of an arrangement of the image-recorder chip, however, 
problems occur, particularly in medical endoscopes, as presently 
image-recording chips are relatively large compared to the size of medical 
endoscopes. The size of the image-recording chip is especially 
inconvenient in endoscopes which are employed not only for examination of 
a cavity, but also for manipulation therein, and have for this purpose 
leading from the distal end to the proximal end a main duct, into which, 
by way of illustration, scissors, tweezers, etc. can be inserted. In order 
that the image, recording chip, not limit too severely the lumen available 
for the main duct, it has been suggested, by way of illustration, in the 
German published patent applications 35 29 026 and 37 20 624 to arrange 
the image-recording chip in a "reclining" manner, i.e. parallel to the 
longitudinal axis of the endoscope. 
Except for this special arrangement of the image-recording chip at the 
distal end piece of the endoscope, the hitherto proposed "video 
endoscopes" differ from conventional ones only in that an image conducting 
system (e.g.,--the relay-lens system), is replaced by an image recorder 
with an electric transmission system arranged thereafter. The construction 
of the rest of the endoscope however, (that is, the lens arrangement 
provided at the distal end, the arrangement of the illumination unit and 
of the ducts, if any, provided for the tweezers, scissors, and the like) 
remains practically unchanged. Such devices yield no new examination or 
treatment possibilities. 
Furthermore, the significance of this simple replacing of an 
image-forwarding system with an image recorder in the state of the art is 
that the overall lumen of the endoscope, i.e. the required cross-section 
area, continues to be essentially determined by the "addition" of various 
lumens, which are needed for the unaltered built-in lens, the ducts for 
the rinse fluids, tweezers, scissors, etc. 
The object of the present invention is to design an endoscope having a 
video device arranged at the distal end thereof in such a manner that new 
examination and treatment possibilities are yielded and that, in 
particular, the overall lumen of the endoscope is no longer determined by 
the addition of various, single lumens needed for the individual 
components, such as lens, rinse and manipulation ducts, illumination 
device, etc. 
The present invention is based on the fundamental concept that there are 
substantially more design possibilities by employing an image-recorder 
arranged at the distal end of an endoscope than with conventional 
endoscopes with "fixed", integrated image-giving systems, regardless 
whether they are provided with a video device or an image-forwarder for 
transmitting the image from the distal end to the proximal end. 
The above object is achieved in accordance with the present invention by 
combining the lens and the image recorder in a video unit, which is 
connected to the endoscope shaft in such a moveable manner that the outer 
contour of the cross-section of the video unit lies essentially within the 
outer contour of the cross-section of the distal end of the endoscope 
shaft when introduced into the cavity to be examined following termination 
of the introduction procedure, the video unit is flexible in relation to 
the distal end of the endoscope shaft to such an extent that the contour 
of the cross-section and/or longitudinal section of the video unit is 
moved beyond the corresponding outer contour of the endoscope shaft. 
In other words, the overall inventive concept consists of no longer 
designing the distal video-examination system as parts fixedly connected 
to the endoscope and integrated in the endoscope structure, as is the case 
in the state of the art, but rather to combine the lens and the image 
recorder and, if need be, the illumination unit for the object field of 
the lens into a video unit, which is moveable as a whole in relation to 
the distal end of the endoscope shaft after being introduced into the 
cavity to be examined. 
This fundamental concept of the present invention can be realized in a 
so-called rigid endoscope as well as in a flexible endoscope. The invented 
design results in a video-endoscope, which has a number of advantages 
compared to prior art endoscopes having a video device arranged in a 
"rigid" manner at the distal end thereof, i.e. fixedly integrated in the 
structure of the endoscope, or the endoscope shaft: 
According to an illustrative embodiment hereto, according to which the 
video unit can be swung about an axis, which is parallel to the axis of 
the shaft of the endoscope and eccentric in relation to the front face of 
the video unit. The video unit can be "swung out" of the endoscope shaft, 
or in the case of an arrangement "before the shaft", out of the 
"cross-section contour" of the endoscope shaft. This permits not only 
examination of the cavity under a different angle of vision, but rather 
especially in an endoscope with at least one main duct for rinsing fluids, 
instruments, etc. has the advantage of improved utilization of the 
available lumen so that the individual lumens, i.e. the cross-section 
areas of the individual components combined are larger than the entire 
cross-section area of the endoscope during introduction into the cavity: 
For this purpose (by way of illustration), the video unit is arranged 
during introduction into and withdrawal from the cavity in such a manner 
that it at least partially covers the duct opening. Following introduction 
into the cavity, the video unit is brought into the examination position, 
in which it clears the main duct. In this manner, the cross-section of the 
endoscope is no longer dictated by addition of the required cross-section 
areas for the duct or ducts and the cross-section area of the lens 
including the video unit, but rather only by the largest lumen of the 
various single lumens. This advantage is also yielded by other 
embodiments, which are described in more detail in the following section. 
In another embodiment the outer diameter of the cross-section of the video 
unit is almost as large as that of the endoscope shaft. This permits a 
comparatively large video unit and thereby the use of a large and 
therefore a fast lens, including the use of an image recorder, (such as, a 
solid image convertor with a large light-sensitive surface). without the 
diameter of the endoscope becoming unacceptably large during the 
introduction and withdrawal phase. 
The swinging movement of the video unit moveably joined at the distal end 
of the endoscope can be carried out in various ways, such as by 
micro-mechanical actuators, by axes running from the distal to the 
proximal end, etc. In a preferred embodiment, a pulling cable running from 
the proximal end to the distal end and back is provided for executing the 
swinging movement according to claim 4 hereto. This embodiment has the 
advantage that the pulling cable can be easily run into the "unused" areas 
of the cross-section of the shaft. 
The endoscope may be provided with (at least) one transmission duct, in 
which elements generating the swinging movement of the video unit, such as 
the previously mentioned (axes also referred to as moving elements 
hereinafter), including, if need be, the transmission system for the video 
signals, are conducted from the distal to the proximal end. 
It is preferable if the transmission duct is connected to the main duct by 
a slit running in the direction of the axis of the endoscope shaft, which 
permits removal of the transmission system from the transmission duct and 
thereby a separation of the video unit from the actual endoscope. Also, 
when the outer contour of the cross-section of the video unit is adapted 
to the inner contour of the main duct, such a connecting slit facilities 
pushing the video unit forward from the proximal to the distal end, or 
pushing the unit back. In this way, the video unit can, by way of 
illustration, be replaced with another video unit having, for example, a 
different focal length and therefore a different field of vision, or with 
a different examination or treatment system, such as a conventional 
examination optics having a lens and image conveyor, without needing to 
remove the endoscope shaft from the cavity. 
Because the video according to the invention unit clears at least the 
largest part of the main duct, an additional conventional examination 
optics having an image conveying system can also be utilized in the main 
duct. 
In any case, it is preferable if the transmission duct also serves as a 
conductor for the element or elements which generate the motion of the 
video unit. 
Naturally, the moving element may also be arranged in the main duct. This 
arrangement is particularly advantageous is a thrust rod serving as a 
moving element is attached to the video unit eccentrically in relation to 
the cross-section of the video unit. This embodiment has the advantage 
that after pushing the video unit forward beyond the distal end of the 
shaft, the video unit is brought into a position, in which it clears the 
greater part of the cross-section of the duct solely by gravity without 
requiring additional measures. 
In a further embodiment of the invention, the contour of the longitudinal 
section of the video unit is designed in such a manner that there is an 
edgeless, smooth transition from the maximum cross-section of the video 
unit to the cross-section of the thrust rod, which ensures that the video 
unit can be drawn back into the main duct by simply pulling back the 
thrust rod thereby permitting easy withdrawal of the endoscope. 
In any case, to achieve to optimum exploitation of the available lumen it 
is advantageous if the moving element, such as the axis or the thrust rod, 
is hollow and the transmission system is run in the moving element. The 
moving element may in this event depending on the design of the endoscope 
(rigid or flexible) be a rigid hollow pipe or a flexible axle. 
Furthermore, the required "pulling cables" may be provided with an 
additional function even in conventional, flexible endoscopes so that, by 
way of illustration, swinging occurs by additionally turning these 
"pulling cables". Moreover, a transparent plastic cylinder, which 
simultaneously serves as the light conductor for the illumination light, 
may be utilized as the element for transmitting the swinging movement. In 
a further embodiment, in the home position, i.e. in the position in which 
the endoscope can be introduced into or withdrawn from the cavity, the 
video unit can be swung completely into the shaft, thus providing optimal 
protection from damage. 
The fundamental concept of the present invention to at least combine the 
lens and the image recorder into a compact unit, which can be swung "out 
of the endoscope shaft" following introduction into the cavity, moreover, 
permits providing not only one swingable unit, but rather several 
swingable units, of which at least one is a video unit. 
It is preferred if the moveable and, in particular, the swingable units are 
arranged in a row at the endoscope shaft at least in the "swung-in 
position", as in that case the available lumen is optimally utilized for 
introduction and the withdrawal procedures. Furthermore, it is also an 
advantage if the units are arranged in a plane which is perpendicular to 
the longitudinal axis of the endoscope, following being swung out. This 
may, by way of illustration, be realized by all the units being initially 
arranged in a row and being "swung into the endoscope shaft". After 
swinging out the units, those units which are arranged behind the front 
most unit are pushed forward into their respective, allocated transmission 
ducts by shifting of their moving elements until they are in the same 
plane as the front most unit. Accordingly, the front units may also be 
correspondingly drawn back. 
Employing video units for all the units permits stereo examination with a 
relatively large stereo base. Accordingly it would also be possible to 
perform a more extensive, redundant depth analysis of the cavity to be 
examined with more than two video units. 
Moreover, only one unit may be a video unit and the other may be provided 
with a light emitter. In this manner, by way of illustration, 
triangulation measuring can be realized. 
Furthermore, in addition to the video unit another image giving recorder 
may be used, by way of illustration, an ultrasonic image recorder. 
The fundamental concept of the present invention to combine the lens and 
the image recorder including, if need be, the illumination unit into a 
compact video unit permits not only swinging this video unit, but also 
moving the video unit in relation to the distal end of the endoscope 
shaft. 
This movement can be oblique, diagonal to the endoscope axis or in the 
direction of the endoscope axis. In particular, a telescopically designed 
moving element may be provided which permits moving the video unit in 
relation to the distal end after completing the introduction and drawing 
back procedures of the unit prior to beginning the withdrawal procedure. 
This telescopic moving element may be run in the main duct or in the 
transmission duct of the shaft. 
The fundamental concept of the present invention to create a compact video 
unit, which is not structurally integrated in the endoscope shaft, 
moreover, permits detaching the video unit from the distal end of the 
endoscope shaft. In this event, the video unit is only connected to the 
proximal supply unit via the transmission system in such a manner that it 
can be employed as a video probe in the cavity. 
In this case, it is an advantage if the video unit designed as a video 
probe can be reattached to the endoscope shaft prior to beginning the 
withdrawal procedure. Furthermore, it is preferred if the video probe can 
be moved forward out of the endoscope shaft (claim 25). A suitable design 
of the "proximal end part" of the video probe even permits removing the 
latter from the hollow organ without an instrument solely by simply 
"pulling it out". 
Another possible movement of the video unit in accordance with the present 
invention, within the overall inventive concept, is a rotation or a 
swinging, of the unit about at least one axis, which is perpendicular to 
the axis of the endoscope shaft. By this means, by way of illustration, a 
video unit, which was "initially lying along the shaft", can be "emplaced" 
following introduction into the cavity. 
Furthermore, images of an object to be examined can be taken from different 
angles of vision. The different possible movements set forth in the claims 
may be employed singly or in combination: thus the video unit can, by way 
of illustration, first be swung out of the endoscope shaft about an axis, 
which is parallel to the axis of the endoscope and eccentric in relation 
to the front face of video unit, and subsequently moved in the direction 
of the endoscope shaft by a telescopically designed moving element. 
Moreover, moving obliquely or diagonally to the axis as well as swinging 
the video unit about an axis, which is perpendicular to the axis of the 
endoscope, is also contemplated foreseen. Naturally, these movements can 
be realized not only by mechanical means. The motions may also be realized 
with suitably designed drive elements, by way of illustration, 
micro-mechanically produced motors, etc. 
The video device, which in accordance with the present invention is set up 
as a unit separated from the actual endoscope, may be set up in the known 
manner. In particular, the image recorders may be arranged perpendicular 
to the axis of the endoscope shaft and parallel to the axis of the 
endoscope shaft. Furthermore, two image recorder with respective lenses or 
one image recorders with two lenses, the image of which can be selectively 
aimed at the image recorder, may also be provided. This embodiment 
permits, by way of illustration, with a 180.degree. lens arrangement, 
examining a substantially larger object field than is possible with a 
conventional lens. So-called straight-vision lenses and so-called 
oblique-vision lenses may also be used. 
As a substantially larger lumen is available for the video unit during the 
introduction and withdrawal procedures due to the fundamental concept of 
the present invention than is the case with conventional video endoscopes, 
an image convertor may, moreover, be provided for each color take, i.e. 
for each primary color, with a dichroic deflection system dividing the 
image of the lens correspondingly. 
Furthermore, the output signals of the image-recorder chip may naturally be 
transmitted "wirelessly" to the proximal end. Preferable, however, with 
regard to the size of the construction, the transmission system is 
realized with connection lines for the electric and/or optical 
transmission of energy and signals. The individual lines may preferably be 
combined to a single connection line which may be employed to push the 
probe forward via the endoscope shaft and to draw back the probe. 
The light exit area of the illumination unit may either be arranged 
"fixedly" to the endoscope shaft or to the video unit. 
The fundamental concept of the present invention, moreover, allows greater 
freedom in the design of the illumination unit. Thus one or several 
miniature filament lamps, strobe lamps, light diodes and/or semiconductor 
lasers may be provided in the video unit. Naturally, however the 
illumination light source may also be arranged proximally in the 
conventional manner and the light of the illumination light source may be 
conducted by means of light conductors to the light exit area, where it 
then emerges. The light conductors may be conventional fiber bundles, or 
rigid rods, which simultaneously serve as moving elements. 
The energy supply of the image recorder and, if need be, of the 
illumination light source, may be realized by providing opto-electric 
and/or electro-magnetic transducers in the video unit, which convert the 
optical or high-frequency electric, respectively inductively coupled-in 
energy into electric energy suited for the image recorder. In reverse, the 
output signal of the video unit can also be translated by an 
electro-optical signal convertor into an optical signal and this signal 
can be transmitted to the proximal end. 
In a further embodiment of the invention, the end area of the video unit 
facing the proximal end tapers and the distal end area of the endoscope 
shaft is designed to compliment it. This arrangement permits sure 
"self-centering" utilization of the video unit or video probe, in the 
endoscope shaft in the version in which the video unit can be moved beyond 
the distal end area prior to beginning the withdrawal procedure, 
particularly a withdrawal of the video probe without it previously having 
been provided on the endoscope shaft. 
In yet another embodiment, chambers which can be filled with fluid, are 
provided, which upon filling stiffen the endoscope against lateral forces, 
thus making the flexible endoscope shaft sufficiently rigid that the 
element can be moved transversely to the endoscope shaft. Moreover, 
partial filling of the chambers results in the endoscope shaft bending. 
The video unit may be separated from the endoscope shaft. In addition, by 
means of an element which can be magnetically influenced, the video probe 
may be positioned independently of the endoscope shaft, for example, from 
outside the body. 
Because connection lines have plugs, the cross-section of which is smaller 
than or the same size as the connection cord, which for its part is 
substantially smaller than the maximum cross-section of the video unit, 
the video unit may be separated from the shaft by just pulling out the 
connection line. 
If need be, the video unit can also have a rinsing duct, which by way of 
illustration can be employed for cleaning the front lens of the objective. 
The cross-section of the endoscope shaft may, of course, be round like 
prior art shafts, whereby the cross-section of the video unit may be round 
but does not have to be. However, the cross-section of the shaft and the 
video unit may be designed in the same manner, not round, but rather by 
way of illustration oval. Clearing the ducts, (for example, tweezer ducts) 
provided in the shaft can occur by turning the video unit 90.degree. in 
relation to the shaft.

DETAILED DESCRIPTION OF THE DRAWINGS 
FIG. 1 shows a first preferred embodiment of the present invention, in 
which a video unit 1 can be swung about an axis 3, which is parallel to 
the axis 2' of the endoscope shaft 2, shown by way of example as a rigid 
shaft. The endoscope shaft is provided in a known manner with a main duct 
4, which by way of illustration can be used for rinsing with rinsing 
fluids or into which instruments such as scissors, tweezers, etc. can be 
inserted. The main duct 4 connects the distal end depicted in FIG. 1, i.e. 
the end of the shaft 2, which can be inserted into the cavity to be 
examined, to the proximal end-(not shown), i.e. the end remaining outside 
of the cavity. 
As the axis of rotation 3 of the video unit 1 is arranged eccentrically in 
relation to the front face of the video unit, the video unit can be swung 
from the position depicted in FIG. 1a, in which it is swung into the main 
duct 4 of the endoscope shaft, in the direction of the arrow 5 into a 
position, in which it completely clears the main duct 4 (FIG. 1b). The 
dimensions of the video unit 1 and of the shaft and the arrangement of the 
axis of rotation 3 are selected in such a manner that the outer contour of 
the video unit lies completely within the outer contour of the shaft when 
the former is in a swung-in state during examination in the direction of 
the longitudinal axis. The "outer contour of the cross-section" of the 
video unit does not extend beyond the corresponding contour of the shaft 
until after a rotation of the video unit about the axis of rotation 3. In 
addition the video unit 1 can be moved along an arrow 6, i.e. parallel to 
the axis 2', permitting not only an alteration of the object field of the 
video unit, but also the insertion of instruments, such as tweezers, 
scissors in the main duct 4, which can be bent to a very great degree at 
the distal end without the bending being hindered by the video unit. 
Naturally, conventional endoscope optics with a lens and an image 
transmission system may be used as an additional examination system in the 
main duct 4. 
In order to realize the rotation and the movement, an element 7 is attached 
to the video unit, the element being run in a transmission duct 8, which 
is provided on the outer circumference of shaft 2. In the embodiment 
depicted in FIGS. 1a to 1c, the movement-transmitting element 7 (moving 
element) is a light conducting rod made of a transparent material. This 
transparent light conducting rod terminates at a light exit surface 7' at 
the front side of the video unit 1. In addition, further light conductors 
9, which are "rigidly" integrated in the structure of the shaft and which 
by way of illustration may be conventional fiber bundles, are provided in 
the illustrated embodiment. 
FIGS. 1d and 1e show another preferred embodiment of the rotation movement 
transmitting element 7. The video unit 1 is moveably joined to the shaft 2 
by means of a shaft 71 in such a manner that it can be swung about the 
axis 3. A pulling line 72 running from the proximal end to the distal end 
of the shaft 2 and back is provided for turning shaft 71, with two rollers 
73 arranged at both sides of the shaft 71 turning the pulling line. Thus 
moving pulling line 72 by a actuating element (not shown) arranged at the 
proximal end results in turning the video unit about the axis 3. 
The video unit 1 is provided with a lens 10 image recorder chip 11 (both 
schematically depicted in FIGS. 1a to 1c). The image recorder chip 11 is 
connectd to a supply unit arranged at the proximal end via the connection 
lines 12. In the preferred embodiment depicted in FIGS. 1a to 1c, the 
connection lines 12 are wound about the rod 7. However, the moving element 
7 may, naturally, also be designed as a hollow pipe, in which the lines 12 
and, if need be, light conducting fibers are run. 
In the preferred embodiment depicted in FIGS. 1a to 1c, the video unit 1 
with the lens 10 and the image recorder 11 provided therein as well as the 
light exit area 7' of an illumination unit can be swung out of a position, 
in which the video unit is essentially arranged at the side of the 
endoscope shaft 2, into the endoscope shaft 2, which is provided for this 
purpose with a corresponding projection 21, which is depicted dark in FIG. 
1c. 
Naturally, the video unit may however be also be arranged before the 
endoscope shaft 2 and accordingly swung before the endoscope shaft 2. This 
is shown in a representation corresponding to FIG. 1a in FIG. 2, in which 
moreover the same designations are used for the same elements as in FIG. 1 
thus obviating another description. 
The preferred embodiment depicted in FIG. 2 also differs from the preferred 
embodiment illustrated in FIG. 1 in that the image recorder 11 is not 
arranged perpendicular to the longitudinal axis 2' of the endoscope, but 
rather parallel thereto. Correspondingly a deflection prism 13 is 
provided, which deflects the image of the lens 10, which, without the 
intention of limiting the scope and spirit of the present invention, is a 
so-called "straight-vision lens" in both preferred embodiments, onto the 
light-sensitive area of the image recorder 11. A so-called oblique-vision 
lens may, of course, also be employed. 
By virtue of the fundamental concept of the present invention to swing the 
video unit 1 before or in the main duct 4 during introduction and 
withdrawal of the endoscope, a substantially larger lumen is available for 
the video unit than in conventional video endoscopes. As a result, not 
only larger lenses and image convertors can be employed than in 
conventional video endoscopes, but also a construction, in which three 
image recorders for the three primary colors, can be provided. 
FIG. 3 shows a corresponding preferred embodiment with the three image 
convertors 11.sub.1 to 11.sub.3. A dichroic image element 14 divides the 
light of the lens 10 into the three image convertors 11.sub.1 to 11.sub.3. 
Other than that, the third preferred embodiment depicted in FIG. 3 
corresponds to the preferred embodiment shown in FIG. 2. 
In the preferred embodiments described in connection with FIGS. 1 to 3, 
only one video unit 1 is provided, which accommodates the lens 10, the 
image recorder 11 and, if need be, the light exit area 7' of an 
illumination unit, and which is moveable following introduction into the 
cavity as a whole in relation to the distal end of the endoscope shaft 2. 
Naturally, more than one video unit can also be provided: 
FIG. 4 shows a fourth preferred embodiment, in which the two video units 1' 
and 1" are provided, the moving elements 7' and 7" of which are run 
coaxially in a transmission duct 8. Other than that, the elements depicted 
in FIG. 4 with the same designations as in the previous figures correspond 
to the elements described, thus obviating another description. 
However, the moving elements 7 for the individual video units can, of 
course, also be run not coaxially but--as shown in a top view in FIG. 
5--in different ducts 8' and 8". If at least one of the two video units 1 
or 1' is designed in such a manner that it can be moved in the direction 
of the longitudinal axis of the endoscope shaft, after swinging out the 
two video units 1' and 1" can be arranged in the same plane perpendicular 
to the longitudinal axis of the endoscope. In this manner, by way of 
illustration, a stereoscopic image is possible. 
Naturally, in the preferred embodiments shown in FIGS. 4 and 5 it is not 
necessary that both units are video units. By way of illustration, one of 
the two units 1', or 1", may accommodate a light source as, by way of 
illustration, a miniature light bulb, a light diode or a laser diode. 
Furthermore, one of the units may also accommodate another image giving 
recorder, as by way of illustration, an ultrasound array. Finally, another 
endoscopic measuring system, such as two laser diodes, may be integrated 
in units 1' and 1" and the examination may be conducted with an 
examination unit, a conventional optical system 1"' or a video unit, 
introduced into the central main duct 4 (FIG. 5b). 
In the preferred embodiments shown in FIGS. 1 to 5, the video unit 1 can be 
swung about an axis 3, which is parallel to the axis 2' of the endoscope 
shaft 2 and eccentric in relation to the front area of the video unit 1. 
In addition, if need be, a movement in the direction of the axis 3 may 
occur. 
FIGS. 6a to 6c depict a sixth preferred embodiment of the present 
invention, in which the video unit 1 can be swung about an axis 20, which 
is perpendicular to the axis 2' of the endoscope shaft 2. Furthermore, in 
this preferred embodiment, the video unit 1 is provided with two lenses 
10' and 10", the optical axes of which enclose a 180.degree. angle, as 
well as two image recorders 11' and 11". 
In the "0.degree. position" shown in FIG. 6a the video unit 1 is folded 
before the endoscope shaft 2, whereas in the 180.degree. position shown 
FIG. 6c it lies parallel to the endoscope shaft 2 and, by way of 
illustration, clears the opening of a duct 4, which is not shown in more 
detail, in the endoscope shaft. FIG. 6b shows corespondingly the 
90.degree. position, in which an examination of the lateral area, such as 
of an operation area, is possible. 
In addition, the video unit may also be swung about an axis 3, which is 
parallel to the axis 2', according to the preferred embodiments shown in 
FIGS. 1 to 5. 
FIG. 7 depicts a seventh preferred embodiment, in which the video unit 1 is 
attached via a ball-and-socket joint 31 to a telescope carrier formed by 
one of the two elements 32 and 33. The telescope carrier for its part is 
again moveably joined to the distal end of endoscope shaft 2. By means of 
this embodiment version, video unit 1 can be pushed forward beyond the 
distal end of the endoscope shaft 2, thereby permitting more extensive 
examination. Moreover, the ball-and-socket joint 31 provided at the front 
end of the telescope, permits examination under different angles of 
vision. 
All the above described preferred embodiments have in common that the video 
unit 1 remains connected via suitable elements to the endoscope shaft 2 
during movement. 
Naturally, the video unit 1 may also be designed in such a manner that in a 
certain position it can be separated from the endoscope shaft 2 or that it 
may be freely inserted into the duct 4, with the connection to the 
proximal end being retained by a thrust element. 
FIG. 8 shows schematically a preferred embodiment, in which the video unit 
1 is connected to the endoscope shaft only via a connection line 12 and 
can be moved by it over the distal end of the shaft in such a manner that 
the video unit can be employed as a video probe. If the proximal end of 
the video unit 1 and the distal end of the endoscope shaft 2 are designed 
in a complimentary manner, the video probe (video unit 1) after having 
been drawn back by means of the line 12, can be easily inserted into the 
corresponding recess in the endoscope shaft 2 once more. 
FIGS. 9a and 9b show a preferred embodiment, in which the video unit 1 is 
only inserted in the main duct 4 of shaft 2 in such a manner that the 
video unit can be moved therein. A thrust rod 7', which is eccentric in 
relation to the cross-section of the video unit and which is also arranged 
in the main duct 4, is provided at the video unit 1. This version has the 
advantage that after the video unit has been moved beyond the distal end, 
the video unit is brought into a position, in which it clears the largest 
part of the cross-section of the duct, without further measures, solely 
due to gravity (FIG. 9b). In the illustrated preferred embodiment, the 
contour of the longitudinal section of the video unit 1 is designed to 
provide an edgeless, smooth transistion from the maximum cross-section of 
the video unit 1 to the cross-section of the thrust rod 7'. In this way, 
it is ensured that by simply drawing back the thrust rod, the video unit 
can be drawn back into the main duct so that in the position depicted in 
FIG. 9a, in which the video unit 1 is arranged in the main duct 4, easy 
withdrawal of the endoscope is possible. 
In the previous section, the present invention has been described using 
preferred embodiments without the intention of limiting the scope and 
spirit of the present invention, within which the most varied and 
different modifications are possible. 
Although the invention has been described and illustrated in detail, it is 
to be clearly understood that the same is by way of illustration and 
example, and is not to be taken by way of limitation. The spirit and scope 
of the present invention are to be limited only by the terms of the 
appended claims. 
In particular, the different possible movements described in the preferred 
embodiments can be combined with each other: 
Thus, a telescopic moving element, at the end of which the video unit is 
joined in such a manner that it can be swung about an axis, which is 
parallel to the axis of the endoscope shaft 2, and rotated about an axis, 
which is perpendicular thereto, may be provided in the transmission duct 
8. Furthermore, a possible means of moving the video unit in one or 
several directions may be provided, which enclose an angle unequal to 
0.degree. with the axis of the endoscope shaft, thus to provide an 
"oblique movement". Furthermore, the endoscope shaft may be designed in 
such a manner that it can be folded open or it may be provided with a slit 
so that the video unit can be withdrawn from the shaft together with the 
connection line attached thereto. For this purpose, a slit may also be 
provided between the main duct 4 and the transmission duct 8. The 
afore-described possibilities, of course, may also be employed to the same 
degree in rigid and flexible endoscopes. In flexible endoscopes it may be 
necessary "to stiffen" the endoscopes by means of fluid chambers, which 
can be so that they become semi-flexible in order to realize the various 
possible movements. 
Furthermore, it may be an advantage to compensate the distal turning in the 
video representation unit arranged at the proximal end by means of prior 
art image processing methods so that, by way of illustration, "up" and 
"down" are not reversed for the observer when the unit is swung. If need 
be, mechanical compensation by turning the image recorder may also occur.