WO2005116711A1

WO2005116711A1 - Aperture converter, illuminating device for an optical observation unit and coupling device for launching light of a light source into the entrance end of a light guide

Info

Publication number: WO2005116711A1
Application number: PCT/EP2005/005778
Authority: WO
Inventors: Peter Reimer; Heinz Abramowsky; Daniel Kolsier
Original assignee: Carl Zeiss Surgical Gmbh
Priority date: 2004-05-26
Filing date: 2005-05-23
Publication date: 2005-12-08
Also published as: DE102004026141B4; DE102004026141A1

Abstract

The invention concerns an optical observation unit comprising: a lamp (11); illuminating optics (31, 32, 35); a light guide (50), which is placed between the lamp (11) and the illuminating optics (31, 32, 35) and which has an entrance end (52) oriented toward the lamp (11) and an exit end oriented toward the illuminating optics (31, 32, 35); a focussing device (13) for producing a ray beam (14), which is comprised of light from the lamp (11) and which is to be launched into the entrance end (52) of the light guide (50), and for launching this ray beam (14) into the light guide (50), and; an aperture converter (70), which serves to convert the aperture of an arising ray beam (14, 33) and which is designed so that light beams of a ray beam (14) passing through the aperture converter are statistically deflected from their original direction by an angle (υ) from a defined angular range. The numeric aperture of the ray beam (14) produced by the focussing device (13) is not matched to the numeric aperture of the light guide (50). The aperture converter (70) is situated between the focussing device (13) and the entrance (52) of the light guide or between the exit (54) of the light guide (50) and the illuminating optics (31, 32, 35).

Description

Aperture converter, lighting device for an optical observation device and coupling device for coupling light from a light source into the entry end of a light guide

The present invention relates to an aperture converter, an illumination device for an optical observation device, in particular for an operating microscope, which comprises a light source, an illumination optics and a light guide arranged between the light source and illumination optics. The invention also relates to a coupling device for coupling light from a light source into the entry end of a light guide.

The lighting systems currently used for optical observation devices, for example surgical microscopes in ophthalmosurgery (eye surgery), usually include halogen lamps as light sources and a fiber-optic light guide for transmitting the light to the illumination optics of the surgical microscope. Such a lighting system is described for example in DE 31 47 998 A1. The light source serves as the primary light source, the light of which is guided to the illumination optics by means of the light guide. The exit end of the light guide then serves as a secondary light source, which is imaged by the illumination optics of the surgical microscope in accordance with the respective requirements in the object field of the microscope in order to illuminate the object. An advantage of such lighting systems is the thermal decoupling of the primary light source, which is a heat source, from the optical one Observation device due to the spatial distance of the primary light source from the optical observation device.

The lighting optics of the lighting device of an optical observation device are generally matched to the emission characteristics of the fiber optic light guide. The numerical aperture of the light guide at its exit end, hereinafter referred to as exit aperture, is of particular importance for the radiation characteristic. The exit aperture determines in particular the opening angle of the illuminating beam emerging from the exit end of the light guide. In other words, the aperture of the illuminating beam depends on the exit aperture of the light guide. The aperture of the illuminating beam is defined as the sine of half the opening angle of the illuminating beam. Half the opening angle is also called the aperture angle

The exit aperture of the light guide is determined on the one hand by the parameters of the light guide itself and on the other hand by the type of coupling of the light into the entry end of the light guide. For example, the numerical aperture at the exit end of a straight cylindrical light guide is equal to the numerical aperture at its entry end.

The coupling of the light into the entry end of the light guide is usually optimized in such a way that the numerical aperture of the entry end of the light guide is used almost completely. The opening angle of the beam of rays coupled into the entry end of the light guide is selected such that its aperture essentially corresponds to the numerical aperture of the entry end of the light guide. If the aperture of the incident beam is larger than the numerical aperture of the entry end of the light guide, part of the beam is no longer totally reflected in the light guide and consequently emerges from the light guide through the cladding. This results in undesired loss of intensity. A too small opening angle of the beam bundle coupled into the entry end, on the other hand, leads to an aperture in the exit end of the fiber optic light guide Illumination beam bundle that is smaller than the maximum possible aperture. However, the lighting optics are generally matched to the maximum possible aperture.

Halogen lamps are frequently used in the lighting devices described. However, if instead of a halogen lamp, for example, a high-pressure discharge lamp with a light output similar to that of the halogen lamp, such as a xenon lamp of the XBO type, is used, the numerical aperture of the entry end of the light guide is generally only partially used. The reason for this is the typically smaller radiation area of the high-pressure discharge lamp compared to the halogen lamp. If the light of the high-pressure discharge lamp is therefore coupled into the entry end of the light guide with the same coupling device as the light of the halogen lamp, the coupled-in beam has a smaller aperture than the beam of the halogen lamp. As already mentioned above, this leads to a change in the aperture of the illuminating beam at the exit end of the fiber-optic light guide, so that the aperture of the illuminating beam and the illuminating optics are no longer optimally matched to one another.

It is now possible to adapt the illumination optics of the optical observation device to the radiation characteristics of the light guide that have changed due to a change in the primary light source. However, this means that different lighting optics must also be provided for different light sources. Alternatively, there is the possibility of adapting the optical elements, for example reflectors and / or lenses, used to couple the light emanating from the primary radiation source into the light guide, so that the coupling again takes place in such a way that at the exit end of the fiber optic light guide the there is an optimally adapted radiation pattern. However, this means that different reflectors and / or lenses have to be used for different light sources. Both options are therefore complex and particularly difficult to implement in a single lighting device. It is known from WO 00/67057 to optimize the coupling of light from a light source into a light guide by means of an aperture transducer arranged in front of the entry end of the light guide. Cone-shaped light guides, parabolic hollow tubes with a mirrored inside and diverging lenses are mentioned as possible aperture converters. Similar elements are also described in US Pat. No. 5,680,257. However, these aperture converters, which additionally have to be introduced into the beam path before the entry end of the fiber optic light guide bundle, lead to an increase in the dimensions of the illumination device. They are therefore particularly unsuitable for retrofitting, because their length means that they cannot be integrated into existing lighting devices, or only with great difficulty.

The object of the present invention is therefore to create an alternative aperture converter.

Another object of the invention is to provide an illumination device for an optical observation device, in particular for an operating microscope, which can be adapted to different light sources in particular by simple means.

It is another object of the present invention to provide an optical observation device with an improved lighting device.

It is also an object of the present invention to provide an improved coupling device for coupling light from a light source into the entry end of a light guide with a certain numerical aperture.

The first task is solved by an aperture transducer according to claim 1, the second task by a lighting device according to claim 4 or a lighting device according to claim 7, the third task by an optical observation device according to claim 8 and the fourth object by a coupling device for coupling light from a light source into the entry end of a light guide according to claim 10. The dependent claims contain advantageous developments of the invention.

An aperture transducer according to the invention is designed in such a way that it statistically deflects light rays of a beam of rays passing through it by angles of a defined angular range from their original direction. In particular, the aperture transducer can be designed such that the angles around which the deflection takes place form a Gaussian distribution. The half-width of the Gaussian distribution can then serve as the defined angular range.

The scattering optical element is an aperture converter that can be produced inexpensively. One factor in the cost reduction is the fact that there is only diffuse scattering in a defined solid angle range. Precisely machined lenses or mirror surfaces are therefore not necessary.

The aperture transducer according to the invention can in particular be implemented as a diffuser, also called a diffuser. In this case, the overall length of the aperture converter can be kept very small. The diffusing screen can therefore also be retrofitted into beam paths, for example of lighting devices, without great effort, in order to ensure an aperture adjustment.

In a first embodiment variant of the lighting device according to the invention, it comprises a light source, a lighting optics, a light guide arranged between the light source and the lighting optics with an entry end directed towards the light source and an exit end directed towards the lighting optics, a coupling device for generating a beam of rays to be coupled into the entry end of the light guide the light from the light source and for coupling the beam into the light guide and an aperture converter for converting the aperture of a beam of rays occurring in the beam path of the lighting device. The light guide can be designed, for example, as a liquid light guide, as a single light-guiding fiber or as a fiber bundle composed of a plurality of light-guiding fibers. In the case of a fiber bundle, the light-conducting fibers can also run in an ordered or disordered manner. Concave mirrors and lenses are particularly suitable as the coupling device. The lighting device according to the first embodiment of the invention is characterized in that the aperture transducer is designed as an aperture transducer according to the invention.

The lighting device according to the invention can in particular be easily adapted to different light sources. When changing the light source, only the scattering optical element has to be replaced. If, for example, the lighting device is optimized for a halogen lamp, but is operated with a high-pressure discharge lamp, an appropriately selected aperture converter according to the invention, i.e. an aperture converter according to the invention with a suitable scattering angle range, so that the illuminating beam can optimally illuminate the object to be illuminated without having to change the illuminating optics or the reflector and / or the lens for coupling the light emitted by the light source into the light guide. If a different type of lamp is now to be used, the aperture converter according to the invention only needs to be replaced - or if a return to the halogen lamp takes place - to be removed in order to ensure the optimal illumination of the object to be illuminated.

In a first embodiment of this embodiment variant, the aperture converter according to the invention is arranged between the coupling device and the entry end of the light guide and can be regarded as part of the coupling device. By means of the aperture transducer according to the invention, the opening angle of the coupled beam can be adapted to the numerical aperture of the entry end of the light guide, for example in the case described above Change from a halogen lamp to a high-pressure discharge lamp. Without the aperture converter according to the invention, such a change would lead to poorer utilization of the numerical aperture of the entry end of the light guide and thus to a radiation characteristic that is no longer optimal at the exit end of the light guide.

In an alternative embodiment of the first embodiment variant, the aperture converter according to the invention is arranged between the exit end of the light guide and the illumination optics. The aperture angle of the beam emerging from the exit end of the light guide can then be influenced by means of the aperture transducer according to the invention. For example, when the transition from a halogen lamp to a high-pressure discharge lamp is no longer optimal, the radiation characteristic of the exit end of the light guide leads to an illuminating beam with an aperture angle that is too low for optimal illumination of the object to be illuminated with the illumination optics. This aperture angle can be increased by means of the aperture transducer according to the invention, so that it is optimally adapted to the illumination optics again.

In a second embodiment variant of the illumination device according to the invention, it comprises a light source, an illumination optics, a light guide arranged between the light source and the illumination optics with an inlet end directed towards the light source and an outlet end directed towards the illumination optics, a coupling device for generating a beam to be coupled into the entry end of the light guide Light from the light source and for coupling the beam into the entry end of the light guide and an aperture converter for converting the aperture of a beam occurring in the beam path of the lighting device. The light guide and the coupling device can have the same configuration as the light guide and the coupling device in the first embodiment. According to the second embodiment variant, the lighting device is characterized in that the aperture transducer is arranged between the light guide and the lighting optics. Arranging the aperture converter between the exit end of the light guide and the illumination optics offers the advantage over arranging between the entry end and the coupling device that the aperture converter is thermally decoupled from the light source. Materials which can not be exposed to the temperatures prevailing in the vicinity of the lamp can therefore also be used as materials for the aperture converter.

In the second embodiment variant, an aperture transducer according to the invention, for example a diffusing screen, can also be used as the aperture transducer. With the aperture converter, the radiation characteristic of the exit end of the light guide can be adapted to the illumination optics, as described above. In the second embodiment variant, however, instead of the aperture converter according to the invention, other types of aperture converters can also be arranged as aperture converters between the exit end of the light guide and the illumination optics. For example, conical light guide elements, conical or parabolic sleeves with mirrored inner surfaces or lenses are conceivable.

An optical observation device according to the invention comprises an illumination device according to the first or the second embodiment variant of the invention. The optical observation device can in particular be designed as a surgical microscope, for example for ophthalmic surgery and neurosurgery.

A coupling device according to the invention for coupling light from a light source into the entry end of a light guide with a specific numerical aperture comprises a focusing device, for example a concave mirror, a lens or a combination of mirrors and / or lenses, for generating a beam directed towards the entry end of the light guide with a certain aperture. The coupling device according to the invention also comprises an aperture transducer arranged between the bundling device and the light guide to influence the aperture of the beam to be coupled into the light guide. The coupling device according to the invention is characterized in that the aperture transducer is designed as an aperture transducer according to the invention.

The aperture converter according to the invention represents a cost-effective means for aperture conversion in a coupling device. By simply exchanging the aperture converter according to the invention, the coupling device according to the invention can be inexpensively adapted to the respective light source during operation with different light sources, which result in different apertures of the light beam to be coupled in.

Further features, properties and advantages of the present invention result from the following description of exemplary embodiments with reference to the attached figures.

Fig. 1 shows a first embodiment for the lighting device according to the invention.

2 shows an aperture converter according to the invention.

FIG. 3 shows the angular distribution of the intensity of a parallel beam after passing through the aperture converter from FIG. 2.

FIG. 4 shows a first possibility for the arrangement of the aperture transducer according to the invention from FIG. 2 in the beam path.

FIG. 5 shows a second possibility for the arrangement of the aperture transducer according to the invention from FIG. 2 in the beam path.

6 shows a second exemplary embodiment of the lighting device according to the invention. FIG. 1 shows a lighting device for a surgical microscope as a first exemplary embodiment of the lighting device according to the invention. The illumination device comprises a light source unit 10, which is generally arranged at a distance from the surgical microscope, an illumination optical unit 30 arranged directly on the surgical microscope, and a light guide 50 for guiding the light from the light source unit 10 to the illumination optics unit 30. One end 52 of the light guide 50 is located in the light source unit 10 and serves as the entry end for the light generated by the light source unit 10. The other end 54 of the light guide 50 is arranged in the illumination optical unit 30 and serves as an exit end for the light transmitted by the light guide 50. The exit end 54 forms the secondary light source of the lighting device.

The light source 11 of the illumination device is located in the light source unit 10 which is arranged remote from the illumination optics unit 30, in order to avoid excessive heating of sensitive parts of the surgical microscope. In addition to the light source 11, which in the present exemplary embodiment is designed as a high-pressure discharge lamp, the light source unit 10 comprises a coupling unit designed as a reflector 13, which reflects light emanating from the high-pressure discharge lamp 11 as a convergent beam 14 in the direction of the entry end 52 of the light guide 50, in order to to couple the light guide 50. In order to avoid transmitting infrared radiation through the light guide, the light source unit 10 also comprises an infrared filter 15, which is arranged between the reflector 13 and the entry end 52 of the light guide 50. In addition, an attenuator 17 can be present between the reflector 13 and the entry end 52 of the light guide 50, which attenuates a possibly too high intensity of the beam 14.

The light beam coupled into the entry end 52 is guided from the light guide 50 to the illumination optics unit 30, where it emerges as a divergent beam 34 from the exit end 54 of the light guide 50. The illumination optics unit 30 comprises a first illumination optics lens 31, which can also be designed as a lens group. It also includes a second illumination optical lens 35, which is formed by the main objective lens 35 of the surgical microscope. Although the main objective lens 35 is shown as an individual lens in FIG. 1, it can in particular also be designed as a lens group. The illumination optics unit 30 further comprises a partially transparent reflecting surface in the form of a partially transparent mirror 32, with which the illuminating beam 33 is deflected in the direction of the main objective lens 35. The illuminating beam 33 passes through the main objective lens 35 to the observation object 37 to be illuminated. The light reflected by the illuminated observation object 37 can then pass through the main objective lens 35 and the partially transparent mirror 32 into the observation beam path (not shown) of the microscope.

In the present exemplary embodiment, a partially transparent mirror 32 arranged in the observation beam path serves to deflect the illuminating beam 33 in the direction of the main objective lens 35, which represents the second illuminating optical lens. In a modification of the exemplary embodiment, at least one reflecting surface which is not arranged in the observation beam path can also be used to deflect the illuminating beam 33 in the direction of the second illuminating optical lens 35. For example. In a stereomicroscope with a common “large” main objective lens for the two partial beam paths of the observation beam path, the reflecting surface for deflecting the illuminating beam 33 in the direction of the main objective lens can be arranged between the two partial beam paths of the stereomicroscope. The reflecting surface then does not impair the observation beam path the entire illumination intensity is deflected in the direction of the main objective. If there is no common main objective for the partial beam paths of the observation beam path or if this should not be used for the illumination, the second illuminating optical lens can also be designed as an independent lens or lens combination.

In the exemplary embodiment, the optical axes of the illumination beam path and the observation beam path also coincide between the observation object 37 and the partially transparent mirror 32. In a further modification of the exemplary embodiment, however, it is also possible for the optical axes of the observation beam path and of the illumination beam path to be inclined relative to one another by up to approximately 10 °, in particular by 2 ° to 6 °. In this case, one or more reflecting surfaces can be arranged laterally offset to the observation beam path, which deflect the observation beam in the direction of the main objective lens. As in the first modification, the reflecting surfaces then do not interfere with the observation beam path, and the entire illumination intensity can also be deflected in the direction of the main lens. In this modification, too, one or more independent lenses or lens combinations can be used as the second illumination optical lens (s) instead of the main objective.

In the exemplary embodiment and its modifications, the reflecting surface can be designed as a mirror surface, for example also as a prism surface.

In the present exemplary embodiment, the reflector 13, the light guide 50 and the optical elements 31, 32, 35 of the illumination optical unit 30 are coordinated with one another in such a way that the observation object 37 is optimally illuminated when using a halogen lamp as the light source 11. For this purpose, the reflector 13 is designed such that it generates a beam 14 with an aperture that essentially corresponds to the numerical aperture of the entry end 52 of the light guide 50. In addition, the optical elements 31, 32, 35 of the illumination optical unit 30 and the radiation characteristic at the outlet end 54 of the light guide 50 are matched to one another in such a way that they have the maximum possible aperture illuminate the observation object 37 optimally at the exit end 54 of the light guide 50.

In the present exemplary embodiment, however, a high-pressure discharge lamp is used instead of a halogen lamp. However, since a high-pressure discharge lamp generally has a smaller radiation area than a halogen lamp of the same power, the reflector 13 is no longer optimally matched to the light guide 50 used. As a result, the opening angle of the convergent beam 14 reflected on the entry end 52 of the light guide 50 is smaller than when using the halogen lamp, so that the numerical aperture of the entry end 52 of the light guide 50 is no longer optimally used. Accordingly, the aperture of the beam transmitted through the light guide 50 and emerging from the exit end 54 of the light guide 50 is smaller than when the halogen lamp is used, so that the radiation characteristic of the exit end 54 - in particular the opening angle of the divergent illumination beam 33 emerging from the exit end 54 - and that optical elements 31, 32, 35 of the illumination optical unit 30 are no longer optimally matched to one another.

In order to nevertheless ensure optimal illumination of the observation object 37, a diffusing screen 70 is arranged in the illumination optics unit 30 immediately behind the outlet end 54 of the light guide 50 as an aperture transducer according to the invention, which increases the opening angle of the illuminating beam 33 to such an extent that the opening angle and the optical elements 31, 32, 35 of the illumination optical unit 30 are optimally adapted to one another again.

The structure and the function of the aperture transducer according to the invention are explained below with reference to FIGS. 2 and 3 using a diffusing screen 70 as an example. The diffusing screen 70 has a flat surface 72 and a surface 74 opposite the flat surface 72 with an irregular surface structure. A beam of light falling through the flat surface 72 into the diffusing screen 70 is emitted statistically deflected from the lens 70 through the side 74 with an irregular surface structure from its original direction. The deflection angles θ are statistically distributed essentially in an angular range from -θFWhM to + θFWh, the distribution depending on the structure of the irregular surface of the side 74 of the lens 70.

The statistical distribution of the deflection angle θ is shown in FIG. 3. The figure shows the intensity I measured for a beam 75 (FIG. 2) incident perpendicularly on the flat surface 72 of the diffusing screen 70 after passing through the diffusing screen 70 as a function of the deflection angle θ. The intensity I is related to the intensity lo, which is measured after the passage in the original direction of the incident beam 75. The distribution of the deflection angles θ, with which the light beams of the beam 75 have been deflected from their original direction when passing through the diffusing screen 70, results from the intensity distribution. It can be seen that the intensity maximum lies in the original direction of the incident beam 75. In contrast to the incident beam 75, however, a not inconsiderable intensity can also be measured in directions which deviate from the original direction of the incident beam 75. At a deflection angle θ of approximately 5.5 °, the intensity of the beam emerging from the diffusing screen 70 is still approximately half of the intensity l ₀ measured in the original direction of the beam 75. The intensity distribution shown in FIG. 3 essentially represents a Gaussian distribution with a half-width (FWhM, filling width of half maximum) of approximately 5.5 °. The larger the half-width of this Gaussian curve, the more divergent is the flat surface 72 The beam 75 impinging on the diffuser after passing through the diffuser 70, in other words, the more pronounced the aperture conversion for the incident beam 75. By changing the surface structure of the surface 74, the half-width θpwh _{M of} the intensity distribution can be increased or decreased. A beam of rays passing through an aperture transducer according to the invention does not have a sharply defined aperture after it has passed through. For a certain aperture angle, it can only be said how high is the proportion of the original intensity that falls within the angular range given by an "aperture angle". If, for example, θπ _{Λ / hM is} determined as the aperture angle, 68% of the original intensity falls in the Angular range from -θFWhM to + θπΛ / hM. If the aperture angle chosen is -2θFWhM, then over 95% of the original intensity falls within the angular range from -2θ _F W _h .vι to + 2θFw _hM . In other words, for each specified percentage a defined angular range can be specified which leads to a corresponding portion of the original intensity falling within this angular range.

The specific choice of the half-value width θπ _/ v _h M and the defined angular range depends on how much of the intensity of the beam is to be coupled into the entry surface 52 of the light guide 50. If the half-value width ΘFW _{h is} chosen too large, the proportion of the intensity present before the aperture conversion that can be coupled into the entrance surface 52 after the aperture conversion is small, since the Gaussian curve then has a large proportion of large scattering angles θ, which at one time Leading exceeding the numerical aperture of the entrance surface 52. On the other hand, if the half-width ΘFWI _I M is too small, the numerical aperture is not optimally used, since only a small part of the intensity before the aperture conversion is noticeably deflected from the original direction. The half-value width OHM _{IM of} the aperture transducer should therefore be chosen with regard to the desired proportion of the intensity to be coupled in as well as with regard to the aperture of the beam before the aperture conversion and the numerical aperture of the entrance surface 52.

Although the operation of the diffusing screen 70 was explained on the basis of an incident parallel bundle of rays, there is no change in the quality of the observation if the incident bundle of rays is a divergent or convergent bundle of rays. Also for divergent or convergent bundles of rays as they pass through the diffusing screen 70, the aperture is enlarged (see FIGS. 4 and 5), which is based on a statistically distributed deflection of the individual beams from their original direction.

The same effect that can be achieved with the lens can also be achieved with any optical element that statistically deflects a light beam passing through it by a certain angle from its original direction. In principle, any optical element which is designed such that it deflects an incident light beam with a statistically distributed probability by an angle θ from its original direction is suitable as the aperture converter according to the invention. As described above, the defined angular range can then be given, for example, by the half-value width of the distribution. However, it is also possible to define the angular range in which the scattering takes place differently. For example, the angular distribution need not be a Gaussian distribution. Depending on the configuration of the irregular surface of the diffusing screen, there may also be a different distribution, for example a more or less rectangular intensity distribution depending on the deflection angle θ. In the case of a rectangular distribution, the defined scattering angle range could be given, for example, by the range of constant intensity if the intensity distribution is plotted against the deflection angle θ from the original direction.

The diffusing screen shown in FIG. 4 has an irregular surface only on its exit side 74. However, the irregular surface can also be arranged on the input side. In addition, it is also possible that both the entry surface and the exit surface each have an irregular surface.

A second exemplary embodiment of the lighting device according to the invention is shown in FIG. The lighting device of the second exemplary embodiment differs from that of the first exemplary embodiment only in that the diffusing screen 70 takes place is arranged between the exit end 54 of the light guide 50 and the lens 31 of the illumination optical unit 30 between the attenuator 17 of the light source unit 10 and the entry end 52 of the light guide 50. The arrangement of the diffusing screen 70 in front of the entry end 52 of the light guide 50 means that a convergent beam of rays coming from the reflector 13, the aperture of which is not optimally matched to the numerical aperture of the entry end 52, can be matched to the numerical aperture (see FIG. 4). At the exit end 54 of the light guide 50, the beam then emerges with an aperture that corresponds to the optimal aperture for the optical elements 31, 32, 35 of the illumination optics unit 30, so that the observation object 37 can be optimally illuminated.

The lighting device of the second exemplary embodiment need not necessarily be designed as a unit. In particular, the lighting device can comprise, as independent units, a light guide, a lighting optical unit, a lamp and a coupling device for coupling the light coming from the lamp into the light guide. The coupling device then comprises at least one focusing device, for example at least one reflector and / or at least one lens, which focuses the light emanating from the light source and directs it towards the entry end of the light guide, and an aperture transducer according to the invention, for example the one described above lens. By inserting a suitable aperture transducer according to the invention, i.e. of an aperture transducer according to the invention with a suitable defined angular range, the coupling device can be adapted to different lamps and / or light guide characteristics without having to replace complex optical elements such as reflectors or lenses.

In the exemplary embodiments, it was shown that, according to the invention, a statistically scattering optical element with a defined scattering angle area can be used advantageously as an aperture converter in lighting devices and coupling devices.

In the first embodiment, a lens 70 is provided as the aperture converter. Instead of the lens 70, however, another aperture converter can also be used in the first exemplary embodiment. Aperture converters in the form of parabolic or conical sleeves with mirrored inner sides, lenses, in particular diverging lenses, or conical light guides are conceivable, for example. However, the aperture transducer according to the invention and in particular the diffusing screen are extremely advantageous due to the possibility of the small overall length.

Claims

claims

1. Optical observation device with a. a lamp (11), b. lighting optics (31, 32, 35), c. a light guide (50) arranged between the lamp (11) and the illumination optics (31, 32, 35) with an inlet end (52) directed towards the lamp (11) and an outlet end directed towards the illumination optics (31, 32, 35), d. a bundling device (13) for generating a beam (14) to be coupled into the entry end (52) of the light guide (50) from light from the lamp (11) and for coupling the beam (14) into the light guide (50), and e. an aperture transducer (70) for converting the aperture of a beam of rays (14, 33) which occurs in such a way that light beams of a beam of rays (50) passing through it are statistically deflected from their original direction by an angle (θ) from a defined angular range marked, f. that the numerical aperture of the beam (14) generated by the focusing device (13) is not adapted to the numerical aperture of the light guide (50) g. and that the aperture converter (70) is arranged between the bundling device (13) and the input (52) of the light guide or between the output (54) of the light guide (50) and the illumination optics (31, 32, 35).

2. Optical observation device according to claim 1, characterized in that the angles (θ) around which the deflection by the aperture transducer (70) takes place form a Gaussian distribution and the half width of the Gaussian distribution forms the defined angular range.

3. Optical observation device according to claim 1 or 2, characterized in that the aperture transducer is a lens (70).

4. Optical observation device according to one of the preceding claims, characterized in that the aperture converter (70) is arranged between the coupling device (13) and the inlet end (52) of the light guide (54).

5. Optical observation device according to one of the preceding claims, characterized in that the aperture converter (70) is arranged between the outlet end (54) of the light guide (50) and the illumination optics (31, 32, 35).

6. Optical observation device according to one of claims 1 to 5, characterized by its configuration as a surgical microscope.

7. A method for adapting an optical observation device with a lamp (11), an illumination optics (31, 32, 35), a light guide (50) arranged between the lamp (11) and the illumination optics (31, 32, 35), which one the inlet end (52) directed towards the lamp (11) and an outlet end directed towards the illumination optics (31, 32, 35), when the lamp (11) is changed, in which a generation of a light guide (50) into the inlet end (52) beam bundle (14) to be coupled in, from the light of the lamp (11), the beam bundle (14) is coupled into the light guide (50) by means of a bundling device (13) and the beam bundle (33) transmitted through the light guide (50) is coupled out marked, a. that the bundling device (13) generates a beam (14) which has a numerical aperture which is not matched to the numerical aperture of the light guide (50), and b. that an adaptation of the aperture of the beam (14) entering the light guide (50) to the numerical aperture of the The light guide (50) or an adaptation of the aperture of the beam (14) emerging from the light guide (50) to the numerical aperture of the illumination optics (31, 32, 35) is carried out by means of an aperture converter (70) which is designed such that it emits light rays of a ray bundle (50) passing through it deflects statistically by an angle (θ) from a defined angular range from its original direction.

8. The method according to claim 7, characterized in that the angle (θ) around which the deflection by the aperture transducer (70) takes place form a Gaussian distribution and the half width of the Gaussian distribution forms the defined angular range.

9. The method according to claim 7 or 8, characterized in that a lens (70) is used as the aperture converter.

10. Aperture transducer characterized by its configuration such that light rays of a beam bundle (50) passing through the aperture transducer are statistically deflected from their original direction by an angle (θ) from a defined angular range.

11. Aperture converter according to claim 10, characterized in that the angles (θ) around which the deflection takes place form a Gaussian distribution and the half width of the Gaussian distribution forms the defined angular range.

12. Aperture converter according to claim 10 or 11, characterized by its configuration as a diffusing screen (70).

13. Illumination device with - a light source (11), - an illumination optics (31, 32, 35), - a light guide (50) arranged between the light source (11) and the illumination optics (31, 32, 35) with a to the light source ( 11) directed entry end (52) and an exit end directed towards the illumination optics (31, 32, 35), - a bundling device (13) for generating a beam (14) to be coupled into the entry end (52) of the light guide (50) from light from the light source (11 ) and for coupling the beam (14) into the light guide (50), and - at least one aperture converter (70) for converting the aperture of a beam (14, 33) occurring in the beam path of the lighting device, characterized in that the at least one aperture converter (70) is an aperture transducer according to one of claims 10 to 12.

14. Lighting device according to claim 13, characterized in that the aperture transducer (70) is arranged between the coupling device (13) and the inlet end (52) of the light guide (54).

15. Illumination device according to claim 13, characterized in that the aperture transducer (70) is arranged between the outlet end (54) of the light guide (50) and the illumination optics (31, 32, 35).

16. Illumination device with - a light source (11), - an illumination optics (31, 32, 35), - a light guide (50) arranged between the light source (11) and the illumination optics (31, 32, 35) with a to the light source ( 11) directed entry end (52) and an exit end directed towards the illumination optics (31, 32, 35), - a bundling device (13) for generating a beam (14) to be coupled into the entry end (52) of the light guide (50) from light from the light source (11) and for coupling the beam (14) into the entry end (52) of the light guide (50), and - An aperture converter (70) for converting the aperture of a beam (33) occurring in the beam path of the lighting device, characterized in that the aperture converter (70) is arranged between the light guide and the illumination optics (31, 32, 35).

17. Optical observation device with an illumination device according to one of claims 13 to 16.

18. Optical observation device according to claim 17, characterized by its configuration as a surgical microscope.

19. Coupling device for coupling light from a light source (11) into the entry end (52) of a light guide (50) with a specific numerical aperture with - a focusing device (13) for generating a directed towards the entry end (52) of the light guide (50) Beam bundle with a specific aperture, and - an aperture converter (70) arranged between the bundling device (13) and the entry end (52) of the light guide (50) for influencing the aperture of the beam bundle (14) to be coupled into the light guide (50), characterized in that that the at least one aperture transducer (70) is an aperture transducer according to one of claims 10 to 12.