Abstract:
An endoscopic system with at least one light source for generating at least partially coherent light, for exciting fluorescent light, with at least one light-conducting element, where the at least one light source and the at least one light-conducting element are positioned in a proximal supply unit. It is further provided with an optical radiance transmission link in an insertion part and with at least one fluorescence converter for conversion into white light. According to the invention, at least one actuator is present, which is coupled with at least one light-conducting element and/or with the at least one light source and/or with the at least one fluorescence converter. With the help of the actuator, perturbations or fluctuations concerning the at least one light-conducting element and/or the at least one light source and/or the at least one fluorescence converter are generated and thereby reduce the speckles in the endoscopic image.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    The present application claims priority of German patent application No. 10 2009 017 940.2 filed on Apr. 17, 2009, the content of which is incorporated herein by reference. 
       FIELD OF THE INVENTION 
       [0002]    The invention relates to an endoscopic or microscopic system for illuminating a surgical area. 
       BACKGROUND OF THE INVENTION 
       [0003]    An endoscopic system of this type is known from patent application JP-2005-205195. 
         [0004]    Endoscopes and microscopes constitute in medicine, by now, an indispensable aid for certain diagnostic and therapeutic questions. In particular, in the context of minimally invasive surgery they make possible a mild alternative to conventional open surgery. The brightest possible illumination of the examination area is an urgent necessity in exploring the examination area, which normally is completely dark, with the help of the observation system of an endoscope, which can take the form of a classical relay-lens system, a fiber image conductor, or an electronic image sensor chip (CMOS, CCD) for video image reception 
         [0005]    In addition to their use in human or veterinary medicine, endoscopic or microscopic examinations have proven themselves as well in technical areas, such as for examining hollow cavities in turbines and engines. Even in these applications, good illumination of the area of investigation can be indispensable for an accurate depiction by the observation system of the endoscope, and should also provide a quantitative measure of fissure lengths. 
         [0006]    The examination area is normally illuminated by a light conductor with a small cross-section, consisting of an optic fiber or a fiber bundle by which light is conducted from an external light source into the examination area. 
         [0007]    The light source must therefore convey light with a high capacity or capacity density, in order to ensure sufficient illumination of the hollow areas. 
         [0008]    For this purpose, arc lamps such as high-pressure xenon short-arc lamps are generally used. These arc lamps radiate incoherent light, which in some cases is imaged or focused onto the light entry end of the optic fibers or of the fiber bundle by means of an appropriate diaphragm or lens system. 
         [0009]    Increasingly, however, light diodes and lasers, in particular laser diodes (LD), are coming into use. Laser diodes comprise higher light densities than light arc lamps. Laser light sources, in addition, have a long lifetime. Laser light can be easily transmitted by thin probes and cables. 
         [0010]    Among possible laser light sources for endoscopes and OP microscopes are laser-pumped fluorescent light sources, continually modulated or pulsed (IR) lasers, blue or UV lasers for fluorescent excitation, continually modulated or pulsed blue or UV lasers, RGB/RGBA white light laser light sources, supercontinuum white light laser sources, or IR lasers. 
         [0011]    The light that is usually emitted by a laser comprises narrow spectral bands. Because of this spectral purity, laser light can preferably be used, in particular, for fluorescent excitations, because this makes it easy to filter out the excitation light. For color reproduction, however, it is optimal to use a white illuminating light with a spectral characteristic as close as possible to a black body radiance. 
         [0012]    In patent application JP 2005-205195, therefore, a fluorescence converter is positioned in the illuminating beam path to generate white light, on the additive color mixing principle, from the blue excitation light of a laser and the yellow light portions arising in a fluorescence converter. The light radiated from an LED or a laser diode (LD) in the blue spectral range is fed by a condenser device into a thin multimode glass fiber. The other end of the glass fiber is equipped with a wavelength transformer element. This element consists of an output portion on the end of the glass fiber, which is encased with fluorescent material. Because of the white light generation concentrated on the distal end of the glass fiber, the embodiment is especially suited for endoscopic applications. By selecting the laser emission wavelengths and the composition of the fluorescent material, a range of color shades is possible in the fluorescence conversion and color mixing. 
         [0013]    The radiated light from lasers is coherent because of the process of its production, whereas the fluorescent light emitted by the fluorescent body because of the excitation with laser light is incoherent. 
         [0014]    The fluorescence converter is also called a fluorescent body in order to emphasize its property as a diffuser body that diffuses the passed-through excitation light in all spatial directions. The diffusion occurs because of the diffuser centers mounted in the volume of the fluorescent body and because of structural effects on the surface. Here the diffuser centers can at the same time also be fluorophores. Because of their dimensions, the diffuser centers selectively can preferably diffuse the short wavelengths. 
         [0015]    Because of the illumination of a surface with at least partial coherent light, so-called speckle patterns can develop on the illuminated area, which can be seen in images of the illuminated area taken with a video camera. 
         [0016]    The speckles are frequently characterized by a granular, bumpy or sandpaper-type texture. The appearance of a speckle can resemble a surface that is sprinkled with fine particles. 
         [0017]    The formation of speckles is less conspicuous and disturbing with moveable, hand-held endoscopic instruments than with stationary instruments or systems, for instance an operation microscope. Because of the stationary, immobile position of the operation microscope or of the target object, the speckles are not transmitted temporally by any hand-shaking motion (tremor) and thus are substantially more recognizable. Thus, also with OP microscopes in addition to the aforementioned endoscopes, a reduction of the speckles is very important. 
         [0018]    U.S. Pat. No. 4,011,403A discloses a laser-illumination and observation system in which means are available for periodic excitation of the system for purposes of speckles reduction. 
         [0019]    Reducing the speckle pattern is indispensable for a reliable evaluation of the image information. Thus, for instance in industrial applications like the inspection of hollow engine spaces, the apparently rough texture of the speckle artifacts can be mistaken for corrosion, impurities, or deposits. 
         [0020]    In medical applications, confusion of the speckle pattern with the appearance of lesions, for instance, could lead to misdiagnoses in medical examinations. 
         [0021]    It is consequently the task of this invention to further develop an endoscopic or microscopic system of the aforementioned type so that it efficiently provides an illumination of the examination area that is as free as possible of speckles. 
       SUMMARY OF THE INVENTION 
       [0022]    With respect to the aforementioned endoscopic or microscopic system, the task is solved in that an aperiodic disturbance of the at least one light-conducting element and/or of the at least one light source by means of an actuator is used to achieve the most effective and efficient possible reduction of speckles. 
         [0023]    The term “disturbance” in the context of the invention encompasses the aperiodic, chaotic, and stochastic use of a physical magnitude as well as modifications in a physical magnitude that include otherwise random components in their time span. The term “disturbance” is to be understood as including in particular mechanical motions, deflections, vibrations, oscillations, or trembling motions. The mechanical motions can include aperiodic, chaotic, irregular, unforeseeable time sequences or those involving other accidental components. The time sequence of a mechanical motion can also be composed of aperiodic, recurring portion and of a portion that is aperiodic, chaotic, irregular, unforeseeable, or involving other accidental components, and consequently can be aperiodic as a whole. As a result, according to the invention a disturbance is produced having a broad range of frequency and amplitude excitation, leading to a highly efficient reduction of speckles. 
         [0024]    The disturbances can cause a modification of the index of refraction of the propagation medium in which the light is transported. With mechanical vibrations, mechanical differences in tension arise, which cause modifications of the index of refraction. Consequently the phase of the light is modulated, so that its coherence can be reduced. In using a Pocker or Kerr cell, by applying tension to the electrodes of the cell an electrical field is produced that can lead to a modification of the index of refraction. As a result of these modifications of the index of refraction of the propagation medium, in turn, the phase of the coherent light can be modulated and its coherence can be reduced. The reduced coherence allows a temporal alignment of the speckles, so that their occurrence and intensity are reduced. 
         [0025]    The term “actuator” in the context of the invention refers to a converter that converts electrical signals, for instance, into mechanic motion. Actors can directly influence physical magnitudes such as temperature, pressure and density of gasses, position and motion of bodies in space. They can also cause electromagnetic effects such as, for instance, electromagnetic waves and impulses. 
         [0026]    Actors can also include, for instance, electrical motors, electrodynamic converters, and electrostrictive, magnetostrictive, or piezoelectric actuators, in particular low volt piezo actuators. Preferred electrical motors include vibration motors that are installed in mobile telephones to trigger the tactile alarm. Because of their economical size, they are ideally suited for use in an endoscopic system. In addition, mass production makes them cost-effective. Actors that influence electrical fields as physical magnitudes can be, for instance, the electrodes of a Pockel or Kerr cell. 
         [0027]    The terms “light-conducting element” or “light conductor” according to the invention include all means known to specialists that can be applied for transmitting the light from the light source to the distal end of an endoscope or microscope. They include, for instance, optic fibers, single-mode fibers, multi-mode fibers, fiber bundles, light-conducting cables, lenses, rod lenses, pulses, filters, light conversion elements, light plugs, mirrors, fiber cones, glass cones, glass bodies, crystal bodies, light boxes, as well as light couplers for connecting the light-conducting fiber(s) to the light source. 
         [0028]    The term “coupling” according to the invention designates every connection that ensures at least partial transmission of energy produced by the actuator. Coupling can be produced as a rigid connection, in particular as a material, form, or power locking connection with the help of a coupling element, allowing a permanent transmission of mechanical motion energy. Coupling can also take the form of a loose connection that exists only at times and causes no complete transmission of mechanical energy from the actuator. It can also be configured as a coil that picks up electromagnetic impulses and thus electromagnetic energy. 
         [0029]    Light sources used according to the terms of this invention to produce at least partly coherent light can also include spectral portions of the UV or IR spectral range of the electromagnetic spectrum. 
         [0030]    In a first embodiment of the invention, the light source and actuator are mounted together on a cooling body, which causes both the off-loading of the heat output of the light source as well as the transmission of the actuator&#39;s mechanical excitations to the light source. The cooling body applied elastically for this purpose thus also serves as a coupling element in addition to its original function. The actuator is thus provided with a control switch that feeds the actuator with a chaotic input signal. The actuator converts the electrical input signal into corresponding mechanical motions, which possess the time sequence of the chaotic input signal. The mechanical motions are transmitted by the cooling body to the light source and stimulate the latter to chaotic motions with low deflection around their resting position. 
         [0031]    As a result of these measures, there is advantageously no longer a necessity for an additional component for coupling the actuator to the light source, thus saving material costs. 
         [0032]    An additional advantage of positioning the actuator on the cooling body is that it becomes possible to carry out an exchange of the actuator and of the related control electronics in a manner that is especially simple and timesaving. Because the actuator and the control electronics are positioned on the cooling body to be freely accessible, no additional time is required during repairs for removing or installing the cooling body. 
         [0033]    In an additional preferred embodiment the actuator is connected directly with a light-conducting element. For this purpose the actuator can include, for instance, a linear power drive or a crank mechanism with drive rod, having a hole-like aperture, for instance as a bore-hole, perpendicular to the drive direction, through which a light-conducting fiber or a fiber bundle as a light-conducting element can be form-locked or loosely fed in. 
         [0034]    As a result of this measure, it is possible to avoid disadjustment of the light source, its imaging lens, as well as other imaging optic components within the endoscopic or microscopic system because of mechanical disturbances caused by the actuator in the endoscopic or microscopic system. 
         [0035]    In a preferred embodiment, a coupling element that can be excited to rotating motions connects the actuator with the light conductor. 
         [0036]    This measure can advantageously be achieved easily, because a coupling that can be excited to rotating motions in the form of an Unruh is a mass-produced item in the watch industry and thus can be obtained easily and cost-effectively. In addition, Unruhs and their actuators are available in miniaturized form thanks to the steady developments of the watch industry, and are adjusted to the requirements of space reduction for use in an endoscope or microscope. 
         [0037]    In another preferred embodiment, the coupling element comprises an attenuator. 
         [0038]    This measure has the advantage that the excitation energy transmitted by the coupling element can be limited in its effect in order to avoid unintended reinforcement of disturbances in the endoscopic or microscopic system, such as in the form of a resonance catastrophe. 
         [0039]    In another preferred embodiment, the actuator comprises an imbalance. 
         [0040]    As an advantageous result of this measure, it is possible to dispense with a separate control switch, which for instance causes a chaotic input signal for the actuator. Instead, the actuator can be operated with a customary direct or alternating current. The actuator produces aperiodic modulated excitation energy, which because of its property converts the light element into a chaotic mechanical motion. Consequently this avoids the cost and complexity for an electronic control switch, which produces a random component. The random component, which is transmitted as a disturbance to the endoscopic or microscopic system, arises because of the mechanical configuration of the coupling. It requires no control function that includes a random component. Because of the random component, in addition there arises a disturbance with a broad frequency and amplitude range, which advantageously allows an efficient reduction of speckles. 
         [0041]    The actuator can advantageously be configured as a cooling ventilator with imbalance, so that the imbalance of the cooling ventilator is produced by localized weighting or removal of part of one blade of the cooling ventilator, especially by break-off. 
         [0042]    As a result of this measure, a cost-effective, easily constructed, and replaceable actuator is made available with imbalance as a compact component. 
         [0043]    In an especially preferred embodiment, by means of the coupling a loose connection is produced between actuator and light conductor. A belt, ring, noose, eyelet, drive rod with borehole, or a screw-shaped curved wire, for instance, can serve as coupling element. The light conductor is guided through the aperture in the coupling element. The light conductor can move freely in lateral direction inside the space surrounded by the edges of the coupling element. The actuator executes mechanical motions, for instance, whose deflections are greater than or equal to the maximum diameter of the cross-section of the aperture of the coupling element. The light conductor also experiences a force, such as a blow, upon the deflection of the coupling element by the actuator, if the distance from the light conductor to the edges of the aperture is smaller than the deflection of the coupling element. Relatively small deflections, for instance, then cause an excitation blow if the light conductor touches the coupling element or is pressed against the light conductor with an insignificantly small force. Because the relative position between the light conductor and the edges of the aperture of the coupling element continually changes in unforeseeable manner, the light conductor experiences a series of blows of purely random character. To produce a random excitation blow requires no control that would contain a random component. Another advantage of this configuration of the coupling is that it can be produced particularly cost-effectively and simply and in addition allows an aperiodic disturbance. 
         [0044]    In an additional embodiment the light source, the optic light element, and the actuator are positioned in the proximal supply unit. 
         [0045]    This measure has the advantage that the endoscopic or microscopic system comprises a compact structure that is technically simple to produce. In addition, this embodiment of the endoscopic or microscopic system proves to be advantageous during the operation because the endoscopic or microscopic system comprises only the housing portion of the proximal supply unit, rather than consisting of several housing parts, so that when the endoscopic or microscopic system is set in motion, for instance, no difficulties can arise that would result from a structure with several housing parts. 
         [0046]    In an additional preferred embodiment, the optic conductor element is configured so that it is electrically and/or thermally insulating. 
         [0047]    This measure has the advantage that no flow of current can be conducted from the light source that is electrically charged to the optic light-conducting element, that is to the light-conducting cable and housing. This increases the safety for the person using the endoscopic or microscopic system, for instance during a medical examination. In addition, the light-conducting element cannot heat up from the inflowing current, so that is not adversely affected by heat in its functioning. 
         [0048]    In another preferred embodiment, the optic light-conducting element is configured as a glass body, in particular as a lens. 
         [0049]    This measure makes possible, advantageously, an embodiment of the optic light-conducting element that is sufficiently known from the state of the art in order to collect light emitted by the light source and, in some cases, to couple it in additional light-conducting elements such as fiber cones, glass cones, light-conducting fibers, and light-conducting cables. In addition, a glass body is especially cheap to produce and because of its low electrical conducting capacity ensures an electrical insulation between the light source and the light-conducting cable. The light-conducting element can also be configured, for instance, as a compound elliptical concentrator (CED) or as a compound hyperbolic concentrator (CHC). 
         [0050]    In an additional alternative embodiment, the optic light-conducting element is made of optic light-conducting fibers. 
         [0051]    This measure likewise offers an advantageous configuration of the optic light-conducting element. The use of light-conducting fibers avoids costly surface shape of the glass body for light-conducting, because the light rays emitted by the light source are conducted by the alignment of the optic light-conducting fibers by the optic light-conducting element. In addition the use of light-conducting fibers allows the exploitation of the entire surface of the distal end area of the light-conducting element that faces the front side of a possibly adjoining positioned light-conducting cable, in order to couple the light rays into the light-conducting cable. 
         [0052]    In another preferred embodiment, the optic light-conducting element tapers in the direction of the light source. 
         [0053]    This measure has the advantage that the cross-section surface of the first end area of the optic light-conducting element can be optimally adjusted to the cross-section surface of the light source or of the fluorescence converter, and consequently an efficient coupling of the light into the optic light-conducting element becomes possible. In addition, the light rays in the optic light-conducting element are widened because of its configuration that widens toward a possibly adjoining light-conducting element, so that the front side of the possibly adjoining light-conducting element, which comprises a greater diameter than the active surface of the light source or of the fluorescence converter, is optimally illuminated. 
         [0054]    In another preferred embodiment, the at least one coherent light source is configured as a semiconducting laser, in particular a diode laser. 
         [0055]    This measure has the advantage that with the development of constantly more economical and higher-capacity diode lasers, they can be used as efficient light sources in the field of endoscopy or microscopy. 
         [0056]    In another preferred embodiment, the light source includes several diode lasers, which emit light of varying wavelength in various ranges of the electromagnetic spectrum, in particular in the visible range. 
         [0057]    This measure has the advantage that the coupling of laser light of various wavelengths makes possible a spectral adjustment to the requirements for observing the scenery in the examination area. 
         [0058]    In another preferred embodiment, a fluorescence converter is positioned on the distal end of the insertion part and is excited to oscillations, according to the invention, by means of an actuator to reduce speckles. 
         [0059]    This measure has the advantage that the effect of the fluorescence converter can be exploited in advantageous manner as a diffuser body. Emitted fluorescent light from the fluorescence converter is sent out in every direction. In addition the fluorescence converter is appropriate as a diffuser body for the at least partially coherent light of the at least one light source and can diffuse this light in all directions. Consequently it is possible to achieve a more uniform illumination of hollow cavities. 
         [0060]    In another preferred embodiment, the fluorescence converter is positioned in the proximal supply unit. 
         [0061]    This measure has the advantage that, as a result, a good cooling of the fluorescence converter can be achieved in the proximal supply unit that can be used as a separate illuminating unit. Because of this modular structure, the proximal supply unit can also be used with various insertion parts, thereby increasing flexibility in the assembly and structure of an endoscopic or microscopic system. 
         [0062]    In another preferred embodiment, the actuator is configured as a vibration motor, which is usually employed to trigger the tactile alarm in mobile telephones. 
         [0063]    This measure has the advantage that such vibration motors are economically available. 
         [0064]    In another preferred embodiment, the actuator is an electromechanical converter, as is used for powering an Unruh in a watch. 
         [0065]    This measure has the advantage that electromechanical converters used in the watch industry have a miniaturized structure, which is particularly suited for insertion in the proximal operating part, for instance of an endoscope, because of the necessity of compressed size. 
         [0066]    In another preferred embodiment, the actuator is a ventilator. 
         [0067]    This measure has the advantage that, in addition to mechanical excitations that are coupled by the ventilator and can be used to produce disturbances in the endoscopic or microscopic system, the system&#39;s airflow can also be used to cool the light source. 
         [0068]    In another preferred embodiment, the actuator is a customary commercial speaker with an upstream-mounted frequency generator. 
         [0069]    This measure has the advantage that speakers can be purchased economically and easily built into a housing. Signals with frequencies greater for instance than 20 kHz can be produced by the upstream-mounted frequency generator. These frequencies cannot be perceived by the human ear. The speaker is fed with signals having frequencies greater than 20 kHz. Consequently the membrane of the speaker excited to oscillations with frequencies that are substantially greater than 20 kHz. 
         [0070]    In an alternative embodiment, the speaker is excited at lower frequencies in the 10 to 1000 Hz range. As a result, a greater oscillation amplitude can be produced with substantially greater power, so that improved alignment and thus reduction of the speckles can be achieved. 
         [0071]    An especially advantageous embodiment of the speaker is possible if the speaker is open. 
         [0072]    With an open configuration of the speaker, the pressure waves produced on the front side of the speaker membrane are essentially compensated by counterpressure of the membrane rear side. As a result, at low frequencies, such as frequencies that are below or equal to the quotient of the speed of sound and speaker diameter, sound is emitted that is scarcely audible. Thus the emission of sound disturbances is favorably reduced, which contributes to keeping the impact of ambient noise at low levels. 
         [0073]    With the open construction of the speaker, pressure waves produced on the front side of the speaker membrane are essentially compensated by counterpressure on the membrane rear side. Consequently, scarcely audible sound is emitted at low frequencies, that is, those below or equal to the quotient of the speed of sound and speaker diameter. Thus, the emission of disturbance noise is minimized in favorable manner, contributing to keeping the impact of ambient noise low. 
         [0074]    In an additional preferred embodiment, the proximal supply unit of the endoscopic system comprises an electrically insulating holder element in which the optic light-conducting element is positioned. 
         [0075]    This measure advantageously allows additional insulation of the light source that is impacted with tension from the optic light-conducting element and housing of the proximal supply unit, so that risk to persons is likewise reduced. 
         [0076]    In another preferred embodiment, the proximal supply unit of the endoscopic or microscopic system comprises an electrically insulating and noise dampening holder element in which the actuator is positioned. 
         [0077]    This measure advantageously allows a minimization of the mechanical disturbances that can be transmitted unintentionally to other parts of the endoscopic or microscopic system than the light-conducting element that is to be excited. In addition, because of this measure it is possible to produce a sound damping of the undesired incidental noises that can arise upon operating the actuator. 
         [0078]    In another preferred embodiment, the proximal supply unit of the endoscopic or microscopic system comprises a low-friction holder element in which the coupling element is positioned. 
         [0079]    Because of this measure, the greatest possible loss-free transmission of energy from the actuator to the light-conducting element is advantageously achieved. 
         [0080]    Additional advantages or properties can be seen from the following description and the appended illustrations. It is understood that the aforementioned properties, and those yet to be elucidated, can be applied not just in the specifically indicated combination but also in other combinations or in isolation without departing from the context of the present invention. 
         [0081]    Embodiments of the invention are depicted in the illustrations and are disclosed in greater detail in the following parts of the patent description. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0082]      FIG. 1  shows a schematic depiction of an endoscopic system. 
           [0083]      FIG. 2  shows a schematic depiction of the proximal supply unit of  FIG. 1 . 
           [0084]      FIG. 3  shows a detailed depiction of the proximal supply unit of  FIG. 1 . 
           [0085]      FIG. 4  shows a schematic depiction of a supply unit with proximally mounted fluorescence converter. 
           [0086]      FIG. 5  shows an actuator with preferred coupling element and light-conducting element. 
           [0087]      FIG. 6  shows another depiction of an actuator with coupling element and light-conducting element. 
           [0088]      FIG. 7  shows an actuator coupled in material connection to a light-conducting element. 
           [0089]      FIG. 8  shows a schematic depiction of suspension of the actuator. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0090]      FIG. 1  shows schematically an endoscopic system  1  with eyepiece  2  and insertion part  3 . The insertion part  3  can be configured as a rigid tube or flexibly. Ahead of or instead of the eyepiece with optic transmission of the observed image, a video camera can be provided with the observed image depicted on a monitor. Mounted in a supply unit  10  is an excitation beam source  5 , which contains a laser diode  14  and a coupling lens  7  for feeding the excitation light into a light conductor  13 , which is configured as a glass fiber. The coupling of the excitation light can also occur directly without insertion of a coupling lens by quasi-contacting the surface of the chip of the laser diode with the proximal end of the glass fiber  13 , where if necessary a minimum distance to the output mirror of the laser chip must be guaranteed for sufficient recoupling into the laser medium. It is also possible of course to provide additional laser diodes with emission of additional wavelengths, whose radiance can likewise be fed into the light conductor  13  or into additional glass fibers. Thus, for instance, spectral weaknesses of the white light can be compensated. The laser diodes can be battery-operated or provided with energy by a network part. 
         [0091]    The glass fiber  13  is passed through a coupling element  19  configured as a metallic eyelet. The metallic eyelet  19  is soldered onto the housing  6  of the actuator  11 , which is configured as vibration motor. The vibration motor  11  is positioned on a holder element  21 , which is secured on the housing  12  of the supply unit  10 . The holder element  21  is at least partly made of materials that possess high elasticity and/or a high damping effect. Through a corresponding appropriate selection of material components of the holder element  21 , it is possible to reduce any transmission of mechanic motions, caused by the vibration motor  11 , onto the housing  12  of the supply unit  10 . The holder element  21  exerts an effect that is comparable to a shock absorber in automotive technology. The eyelet  19  is struck against the glass fiber  13  by means of the motions of the vibration motor  11 . The reserve length of the glass fiber  13  can be formed into a spiral. This allows a great part of the glass fiber  13  to be excited to mechanical motions, without at the same time necessarily raising the amplitudes of the vibration motions of the vibration motor  11 . In  FIG. 1  the double arrow indicates the direction of motions caused by the actuator  11  in the illustrated embodiment. 
         [0092]    To connect the supply unit  10  with the endoscopic system  1 , a light-conducting cable  24  is provided, which can be connected to the supply unit  10  by special or commercially produced plug-in connection on the endoscope or for instance with a light-conducting plug  15 . Other types of connection are also possible, such as demonstrated in the detail in  FIG. 2 . The plug-in connections can, in particular, be produced as autoclavable and laser-protected. The glass fiber  8  is usually fed through the insertion part  3  to the distal end, either loose or in a separate illumination channel or in a protective casing. At the distal end a fluorescence converter  4  is positioned, in which the conversion occurs in white light. The fluorescence converter  4  can be functionally replaceable or integrated into a replaceable exchange head on the distal end of the insertion part. The imaging lens is not further illustrated here. 
         [0093]    The supply unit  10  of the endoscopic system  1  is shown in  FIG. 2 . The supply unit  10  comprises a housing  12  in which a light source  14 , a light conductor  13 , an actuator  11 , coupling element  19 , and a cooling device  18  are positioned. 
         [0094]    The light source  14  is thermally conducting in connection with the cooling device  18 ; that is, with a heat conductible cooling body  20 , where a thermally conducting connection is understood as a direct or indirect thermal coupling of both components. The cooling body  20  is positioned on a side of the light source  14  turned away from the optic light conductor  13 , where the light source  14  is mounted preferably directly on the cooling body  20 , so that heat produced by the light source  14  can be given off directly to the cooling body  20  and removed by it. The cooling body  20 , in addition, is thermally conducting in connection with the housing  12 , so that heat absorbed by the cooling body can be diverted to the housing  12 . The cooling body  20  in terms of its dimensions is configured to be large in comparison to the light source  14 , so that the cooling body  20  can efficiently absorb and remove heat produced by the light source  14 . 
         [0095]    The actuator  11  sits on an elastic carrier element  23  that is secured onto a holder element  21 . The holder element is directly connected with the housing  12 . A motor  27  with an imbalance element  29  is positioned in the housing  25  of the actuator  11 . When the motor  27  is in operation, the imbalance element, configured in the form of an eccentric disc, rotates around the motor shaft  31 . The housing  25  of the actuator  21  is deflected by the rotary motion of the imbalance element. These deflections are transmitted directly onto the coupling elements  19 , which are in material connection with the housing  25 . The elastic carrier element  23  prevents transmission of the deflections onto the holder element  21 , whereby the deflections could spread themselves to the housing  12  and thus in the entire supply unit and would lead to unintended disturbances of the endoscopic system  1 . 
         [0096]    The light-conducting element  11  is configured as light-conducting fiber. It is in a light-conducting connection by a light-conducting connector  15  with the light source  14 , which is configured in the form of a diode laser. The light-conducting element  13  is conducted through by the larger openings of the coupling elements  19 , which are configured in the form of metal rings. The coupling elements  19 , when the motor  27  is in operation, strike from time to time unforeseeably against the light-conducting element  13  because the eccentric disc  29 , which rotates around the motor axis  31 , deflects the housing  25  of the actuator  11  and the coupling elements mounted on it. As a result, the course of the beam path is modified in the light-conducting fiber, so that the coherence of the light of the laser diode  14  on the distal transition of the light fiber  13  to the optic light-conducting coupling element  17  is destroyed. The light-conducting coupling element  17  produces a light-conducting connection between the light-conducting fiber  13  and the optic light-conducting element  16 . 
         [0097]    A proximal end  22  of a light-conducting cable  24 , which is connected with an insertion part (compare  FIG. 1 ), can be inserted into the housing  12  through a cylinder  28  mounted in an aperture  26  of the housing  12 , or the proximal end  22  of the light-conducting cable  24  can be mounted, once inserted, firmly in the supply unit  10 . The proximal end  22  of the light-conducting cable  24  comes to rest in the housing  12  in such a way that a front surface  30  of the proximal end  22  of the light-conducting cable  24  points in the direction of the light source  14  and is positioned at a close distance from it. Mounted between the front surface  30  of the proximal end  22  of the light-conducting cable  24  and the light source  24  is the electrically insulating optic light-conducting element  16 , which is held by an electrically insulating holder element  32  in the housing  12 . 
         [0098]    According to  FIG. 3 , the cylinder  28  is positioned in the opening  26  in order to insert the proximal end  22  of the light-conducting cable  25  into the housing  12  of the supply unit  10 . The cylinder  28  is configured as a short, cylindrical hollow tube with a ring-shaped widening  34  that serves to secure the cylinder  28  on the housing  12 . Mounted in material connection in the cylinder  28  is a frame  36 , which likewise is configured as a cylindrical hollow tube. A first end area  38  of the frame  36 , which is positioned outside the cylinder  28 , that is, outside the housing  12  and is inserted through the proximal end  22  of the light-conducting cable  24  into the housing  12 , is widened in a ring shape. A second end area  40  of the frame  36  comprises a fully surrounding recess  42 , whose diameter is greater than an interior diameter of the frame  36 . A first segment  44  of a disc  46  is enclosed, in material connection, in the recess  42 . A second ring-shaped segment  48  of the disc  46  comprises a greater outer diameter than the first segment  44  of the disc  46  and than the frame  36 , so that it extends beyond the frame  36 . The disc  46  also comprises a cylindrical passage  50  whose inner diameter corresponds approximately to an inner diameter of the frame  36 . The optic light-conducting element  16  is mounted in the passage  50  of the disc  46 . 
         [0099]    The holder element  32  shown in  FIG. 2  is configured here as the frame  36  and the disc  46 , where both components are produced from an electrically insulating material such as plastic. 
         [0100]    The light source  14  is positioned at a distance from the a front side  52  of the second segment of the disc  46  and connected backwards with the cooling body  20  by at least one screw  54 , where the at least one screw  54  can be configured, for instance, as an M3 thread. 
         [0101]    A light-conducting fiber  13  is in a light-conducting connection with the light source  14  by way of a light-conducting plug connector  15 . The distal end of the light-conducting fiber  13  is in light-conducting connection with the optic light-conducting element  16 , which is positioned in the cylindrical passage  50 , by means of a light-conducting coupling element  17 . 
         [0102]    The light-conducting fiber  13  is surrounded by the coupling element  19 , which is configured for instance as a metallic ring. In the embodiment of  FIG. 2 , no material or form-locking connection exists between the coupling element  19  and the light-conducting fiber  13 . 
         [0103]    The coupling element  19  is in material connection with the actuator  11 , which takes the form of a vibration motor in the embodiment illustrated in  FIG. 2 , as it is used for tactile signaling in mobile telephones. The actuator  11  is connected, by non-illustrated connecting connections, with a control can be operated by a switch and regulator on the front side (not illustrated) of the supply unit  10 . The actuator  11  in particular can be switched on and off, so that more complex switchings of the powering of the actuator  11  can also be arranged. 
         [0104]    The actuator  11  is positioned on an elastic carrier element  23 , which is mounted on a holder element  21  that is secured on the inside of the housing  12  of the illumination system  10 . The elastic carrier element is configured in such a way that as few vibrations as possible of the actuator  11  are transmitted to the housing  12 . 
         [0105]    The cooling device  18  is configured as a passive cooling in this preferred embodiment and functions by heat conduction between the light source  14  and the cooling body  20 . It comprises the heat conducting cooler body  20  that serves for conducting heat produced by the light source  14  and is positioned on the side of the light source  14  turned away from the optic light-conducting element  13 . The cooling body  20  also comprises raised ribs  58  to increase heat deflection, which taper toward their free ends. The ribs are spaced apart in such a way that screws  62  are positioned in the intervening surfaces  60  and serve to secure the cooling body  20  to the housing  12 . 
         [0106]    Heat produced by the light source  14  is transferred to the cooling body  20  by the direct contact between the light source  14  and the cooling body  20  as well as by the at least one screw  54 . Heat conducted to the cooling body  20  is distributed along the cooling body  20  and is conducted by it onto the housing  12 . 
         [0107]    The cooling device  18  can likewise be configured as a heat pipe, where the cooling body  20  is configured for this purpose, for instance as a closed-off hollow body of a heat-conducting material such as aluminum. A capillary-acting, wick-like material is positioned on an inside surface of the hollow body. The hollow body is also filled with a liquid under its own pressure or possibly under a reduced pressure. If heat is conveyed from the light source  14  to a surface of the heat pipe, then the liquid in the interior of the heat pipe starts to boil and converts to steam by absorbing heat energy. This steam is distributed in the hollow body and condensed while emitting heat to a cooler place on the inner wall of the heat pipe. The capillary acting, wick-type material again absorbs the condensed liquid and transports it back to a place on the heat pipe on which heat is conveyed. The heat pipe therefore forms a closed cooling circuit by which the illuminating system  10  can be cooled efficiently. 
         [0108]    The proximal end  22  of the light-conducting cable  24  can be held in the frame  36  by a fixing mechanism. For this purpose a locking lever  64  is positioned on the frame  36 , by means of which the proximal end  22  of the light-conducting cable, for instance, can be clamped shut. 
         [0109]      FIG. 4  shows a proximal supply unit  10  in which a fluorescence converter  4  is already positioned. The fluorescence converter  4  closes off the three-legged housing  9  of the excitation ray source  5 . The light source  14  is configured as a laser chip whose active surface is turned toward the fluorescence converter  4  and illuminates said converter. The laser chip  14  is positioned on a cooling body or heat conducting body  20 . The heat conducting body  20  is mounted on the housing  9 . The heat is emitted from the laser chip  12  onto the heat conducting body  20  and then to the housing  9  and from there is conveyed onward to the supply unit  12  by cooling sheet metal that is not shown and by fixing elements. 
         [0110]    The laser chip  14 , which in this example supplies excitation light in the blue spectral range, excites the fluorescence converter  4 . The fluorescent radiance of the fluorescence converter  4  and the transmitted excitation light of the laser chip  14  form a white light. This white illuminating light is radiated in a wide angle of the space (not shown) in the direction of the light-conducting element  16 , which in this example takes the form of conical glass conical stump. Between the cover surface of the glass conical stump  16  and the fluorescence converter  4 , compensating media, not illustrated, can be provided for flexible compensation of the index of refraction. 
         [0111]    The glass conical stump  16  is secured on a socket-shaped elastic carrier element  23  made of rubber. The carrier element  23  is positioned on a holder element  21 , which is installed in the housing  12  of the supply unit  10  in the form of a metal plate or circuit board. Situated beside it is an actuator  11 . The motor  27  of the actuator  11  is mounted on an additional elastic carrier element  23 ′. The rotary motor  27  comprises an imbalance  29 , which is secured on its motor axis. 
         [0112]    The coupling element  19 , which is formed from an open, three-member chain of ring-shaped links, is secured on the housing  25  of the motor  27  and on the glass conical stump  16 . A connection for power transmission between the motor  27  and the glass conical stump  16  is thereby produced. The rotary motions of the motor  27 , because of the imbalance  29 , set the motor housing  25  in vibrations, which are transmitted by the individual chain members of the coupling element  19  onto the glass conical stump  16 , so that the loose configuration of the transmission chain modifies the time sequence of the vibrations. The resulting disturbances cause tension modifications in the glass conical stump  16 , which lead to corresponding time changes in the index of refraction of the glass conical stump. The oscillations of the index of refraction modulate the phase of the electromagnetic light, which is conducted by the glass conical stump  16 . The temporal coherence of the excitation radiance is conveyed with the oscillations of the phase induced by the temporal variations of the index of refraction, so the index coherence is reduced and in the best case is realigned. 
         [0113]    The front side  30  of a class fiber bundle  8  is positioned at a close distance essentially parallel to the ground surface of the glass conical stump  16 . The intermediate space formed thereby can in turn comprise compensating media (not illustrated) for flexible compensation of the index of refraction in order to keep the light losses at this coupling site of the light conduction as low as possible. The glass fiber bundle  8  runs inside a light-conducting cable  25  whose distal end, not illustrated, is connected to the light-conducting connection of an endoscope. The light-conducting cable  24  includes on its proximal end  22  a plug-in connection  15 , which is inserted form-locked into the connection cylinder  28  of the housing  12  of the supply unit  10 . 
         [0114]    The actuator  11  can, as shown for example in  FIG. 5 , also take the form of a commercially available speaker  310 . The speaker housing  312  is secured on the housing  12  of the illuminating system  10  (not shown). The coupling element  19  is cemented onto the speaker membrane  320  and is configured as a plastic ring. The light fiber  13  is conducted through the plastic ring  19  and is in light-conducting connection with the light source  14 , which takes the form of a diode laser (not shown). The connecting lines  335  and  336  connect the speaker  310  with the frequency generator  340  by means of the connector cylinders  336  and  338 . The frequency generator has available a regulator  342  and a frequency monitor  344 . The speaker membrane can be impacted with signals of the frequency generator that can no longer be perceived by the human ear. These signals deflect the speaker membrane  320 , which in turn deflects the cemented-on plastic ring  19 , which pushes against the light-conducting fiber  13  and thus causes disturbances of the ray path in the light-conducting fiber  13 . 
         [0115]    In the preferred embodiment shown in  FIG. 6 , a metallic flywheel  400  serves as coupling element between the actuator  11  and the light-conducting element  13 . The flywheel is mounted rotatably on the axle  404  that is secured to the fixing rod  470 . The fixing rod  470  is positioned on the elastic carrier element  23 . 
         [0116]    The flywheel  400  comprises, in addition to the central borehole  402  for the rotary axle  404  an outer axial borehole  430  through which the light conductor  13  is passed in form-locking connection. The light conductor  13  here can in addition be in a material connection with the flywheel, for instance by an appropriate cement or a molding mass that is inserted into the bore-hole  430  between the flywheel  400  and the light conductor  13 . 
         [0117]    The inner end of a spiral spring  440  is connected on the rotary axle  402  with the flywheel  400 . The outer end of the spiral spring  440  engages in a borehole  442  of a lever  450 , in which borehole the outer end of the spiral spring  440  is secured. The lever  440  is rotatably connected on the rotary axle  402  and rotatably connected with the drive rod  420  by a pin  444 , which is surrounded by a borehole of the lever in form-locking connection. 
         [0118]    The actuator  11  comprises an eccentric disc  410 , which rotates around the rotary axle  412  of the motor  27 . The drive rod  420  is form-locked through a borehole with the pin  446 , which is secured on the eccentric disc  410 . The rotary motion of the eccentric disc, which is set off by the motor  27 , is transformed into a rotary motion of the flywheel  400  by means of the transmission chain, which is made up of the drive rod  420 , the lever  450 , and the spiral spring  440 . 
         [0119]    A permanent magnet  460  is positioned on the elastic carrier element  23 . Upon the rotation of the metallic flywheel  400 , induction currents are set off by the permanent magnet  460  and their magnetic field works against the magnetic field of the permanent magnet, so that the motion of the flywheel  400  is braked. 
         [0120]    An imbalance  29  can, in addition, be positioned on the flywheel  400 . 
         [0121]    The motion of the flywheel  400  can be described by the angle that is formed by the axles  480  and  490 . 
         [0122]    The motion of the flywheel be described by a differential equation of the type 
         [0000]      θ″+ a 1 *θ′+a 2*θ +a 3*sin(θ)= a 4*sin(ω* t ) 
         [0123]    where the high-placed vertical line signifies the derivation over time. The horizontal rule ω designates the motor&#39;s rotation frequency. The constants a1, a2, a3, and a4 are linked with the moment of inertia of the flywheel  400 , the mass of the imbalance  29 , the gravity acceleration, the spring constant of the spiral spring  440 , and the damping constant, which is a result of the braking effect of the permanent magnet  460  on the metallic flywheel  400 . The values of these magnitudes can be attuned in such a way that a chaotic course is derived for the angle θ as a function of time, as can be seen in the book  Nonlinear Dynamics and Chaos , by J. M. T. Thomson and H. B. Steward (New York: John Wiley and Sons, 1986). 
         [0124]    In a chaotic deflection of the flywheel  400 , the course of the ray path inside the light-conducting fiber  13  is perturbed in corresponding manner, so that the coherence of light is perturbed and this works against the occurrence of speckles at the distal end of the endoscopic system  1 . 
         [0125]      FIG. 7  shows an especially simple embodiment of the coupling of an actuator  11  with a light conductor  13 . The actuator  11 , which is configured as an electromotor, is positioned on a holder element  21 , which is configured as a socket. The light conductor  13  in the form of a glass fiber is cemented directly on the housing  6  of the electromotor  11  by a drop of cement. The electromotor  11  sets an imbalance element  29  in motion by a drive shaft  500 , as shown by the bent arrow in  FIG. 6 . The housing  6  of the electromotor  11  is set in motion through the rotation of the imbalance element  29 , so that the directions of rotation are shown by the double arrow. The rotations are transmitted directly onto the glass fiber  13  by the material-locked connection, which is produced by the drop of cement. 
         [0126]    An especially favorable suspension of the actuator  11  is shown in  FIG. 8 . The holder element  21  of the actuator  11  is configured as a circuit board, which comprises a right-angle recess  600 . The circuit board  21  is built into the housing  12  (not illustrated) of the supply unit  10 . The recess  600  has on its longer sides slit-shaped fixers  612 ,  614 ,  616 , and  618 , which are placed opposite one another in pairs. The motor  27  of the actuator  11  is held in shaking motion in the right-angle recess  600  of the circuit board  21  by O rings  622 ,  624 ,  626 , and  628 . The O rings surround the housing  25  of the motor  27  and are secured in the fixers  612 ,  624 ,  616 ,  618 . The surface of the motor housing  25  includes grooves for better control of the O rings. The imbalance  29  is secured on the rotary axle of the motor  27 . A coupling element  19  is soldered onto the motor housing  25  in the form of a metal ring  19 . The metal ring  19  surrounds a light-conducting element  13 , which is configured as a laser fiber. 
         [0127]    As a result of the shifting suspension of the motor  27 , the transmission of motor vibrations onto the housing  12  or other components of the proximal supply unit  10  is kept small, so that unintended disturbances of the endoscopic system are to the greatest possible extent avoided.