Abstract:
A confocal microscope comprises a microlens array having a plurality of microlenses for splitting a ray bundle of illumination light into a plurality of convergent partial ray bundles which illuminate a sample simultaneously at several measuring points; a beam splitter for separating a beam path of the illuminating light and a beam path of sample light originating from the illumination of the sample and captured in an inverse direction with regard to the illumination light; a pinhole diaphragm array having a plurality of pinhole diaphragms arranged in the beam path of the sample light and corresponding to said microlenses of said microlens array splitting the illumination light; and a further microlens array having a plurality of microlenses corresponding to said microlenses of said microlens array splitting the illumination light. Said microlenses of said microlens array splitting the illumination light and said microlenses of said further microlens array are arranged in the beam path of the sample light. Said beam splitter is arranged in an area between said microlens array splitting the illumination light and said further microlens array; and said pinhole diaphragms of said pinhole diaphragm array are not arranged in the area between said microlens array splitting the illumination light and said further microlens array.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application is a continuation of International Patent Application PCT/EP03/04470 filed Apr. 29, 2003 and claiming priority to co-pending European Patent Application No. 02009913.1 filed May 3, 2002, both of which are entitled “Konfokales Mikroskop mit zwei Mikrolinsenarrays und einem Lochblendenarray”. 
     
    
     FIELD OF THE INVENTION  
       [0002]     The invention relates to a confocal microscope with a microlens array for splitting a ray bundle of illumination light into a plurality of convergent partial ray bundles, in order to illuminate a sample simultaneously at several measuring points, a beam splitter for separating the beam path of the illumination light and of the sample light originating from the illumination of the sample and captured in an inverse direction with regard to the illumination light, and a pinhole diaphragm array in the beam path of the sample light which corresponds to the microlens array for splitting the illumination light.  
         [0003]     Inter alia the invention relates to confocal fluorescence light microscopes in which the sample light is emitted by the sample because of a decaying energy state excited by the illumination light.  
         [0004]     Further, the invention particularly relates to such confocal microscopes of the kind described at the beginning in which a scanning device is provided for moving the microlens array and the pinhole diaphragm array synchronously in parallel to their planes of main extension to scan the sample in-plane. Additionally, the sample may also be scanned in the perpendicular z-direction to three-dimensionally record the sample. All further units of the microscope besides the microlens array and the pinhole diaphragm array may be constructed in such a way that they are common to all partial ray bundles of the illumination light and the captured sample light, i.e. that they are neither divide the illumination light into the single partial ray bundles nor the sample light in a corresponding way. Thus, for example, as a rule one common objective is provided for all partial ray bundles. In the same way, any ocular is also common to all parts of the sample light.  
       BACKGROUND OF THE INVENTION  
       [0005]     It is known that the spatial resolution in measuring a sample in z-direction is increased in a confocal microscope by means of a pinhole diaphragm arranged at a point which is equivalent to the desired measuring point. In a microscope of the kind described at the beginning this increase is achieved with regard to all measuring points. I.e. the pinhole diaphragms of the pinhole diaphragm array are arranged in the beam path of the sample light at points which are equivalent to the measuring points. At the same time, the position of the measuring points is defined by the division of the ray bundle of illumination light into the partial ray bundles by means of the microlens array as each measuring point is the projection of a focus of a convergent partial ray bundle into the sample. In so far, the microlens array and its arrangement have to correspond to the pinhole diaphragm array and its arrangement.  
         [0006]     A confocal scanning fluorescence microscope comprising two microlens arrays and a pinhole diaphragm array is known from U.S. Pat. No. 5,717,519 A. Here, the microlens array is realised as a microlens wheel, which is arranged in parallel to a so called Nipkow-disc which forms the pinhole diaphragm array. The microlens wheel and the Nipkow-disc may be rotated about a common rotating axis running perpendicular to their respective planes of main extension so that a scanning device for the sample is realized. A Nipkow-disc is a rotating disc with a spiral-shaped arrangement of pinhole diaphragms around the rotating axis. In the known confocal microscope the ray bundle of illumination light first passes through the microlenses of the microlens wheel. As a result, the illumination light is split up into a plurality of convergent partial ray bundles. The focus of each partial ray bundle is in the area of the passage way of a pinhole diaphragm of the Nipkow-disc. The beam splitter which deviates the sample light coming from the sample through the Nipkow-disc in front of the microlens wheel laterally towards a detector is arranged between the microlens wheel and the Nipkow-disc. Particularly, the beam splitter is a dichroitic mirror, which also results into an undesired deflection of the convergent partial ray beams coming from the microlens wheel. To compensate for this deflection, the microlens array and the Nipkow-disc in the known confocal microscope are tilted by a small angle towards the beam axis of the incident beam bundle of the illumination light coming from a laser. In the known confocal microscope the sample light does not pass through the microlenses of the microlens wheel; instead it is prior to that deflected by the dichroitic mirror laterally towards the detector. The high laborious adjustment of the microlens array with regard to the Nipkow-disc is a disadvantage of the known confocal microscope. If essentially the full illumination light coming from the laser is to be used for illuminating the sample in the measuring points, the Nipkow-disc has to be exactly orientated in such a way, that each focus of each convergent partial ray bundle coming from the microlens array exactly falls in the passage way of a pinhole diaphragm of the Nipkow-disc. This means high demands with regard to the parallelism of the microlens wheel and the Nipkow-disc, with regard to their distance and with regard to their rotational orientation about the common rotation axis. Further, the absolute orientation of this rotation axis has to be adjusted exactly to realize the desired compensation for the deflection of the partial ray bundles by the dichroitic mirror. In all that, it has to be considered that the beam splitter is arranged between the m microlens wheel and the Nipkow-disc and that the beam path of the sample light in radial direction from the common rotation axis of the microlens wheel and of the nipkow-disc should not even temporarily be interrupted.  
         [0007]     A scanning fluorescence microscope is known from WO 98/28775 A in which the pinhole diaphragm array is omitted for avoiding the laborious adjustment of a pinhole diaphragm array with regard to a microlens array. The spatial resolution in z-direction of the known microscopy is realized by means of a simulation of a pinhole diaphragm array in the area of the detector by means of software, or by means of a two-photon-excitation of the sample in the measuring points. However, the effect of a real pinhole diaphragm array increasing the spatial resolution, i.e. the spatial resolution in z-direction of a real confocal arrangement can not be achieved by a simulating of a pinhole diaphragm array in the area of the detector, and the yield of sample light is comparatively low with a two-photon-excitation of a sample.  
         [0008]     Thus, there is a need for a confocal microscope comprising two microlens arrays and a pinhole diaphragm array in which the actual adjustment labour is reduced, and which as a result can be realized at lower cost.  
       SUMMARY OF THE INVENTION  
       [0009]     The invention relates to a confocal microscope comprising a microlens array having a plurality of microlenses for splitting a ray bundle of illumination light into a plurality of convergent partial ray bundles which illuminate a sample simultaneously at several measuring points; a beam splitter for separating a beam path of the illuminating light and a beam path of sample light originating from the illumination of the sample and captured in an inverse direction with regard to the illumination light; a pinhole diaphragm array having a plurality of pinhole diaphragms arranged in the beam path of the sample light and corresponding to said microlenses of said microlens array splitting the illumination light; and a further microlens array having a plurality of microlenses corresponding to said microlenses of said microlens array splitting the illumination light; said microlenses of said microlens array splitting the illumination light and said microlenses of said further microlens array being are arranged in the beam path of the sample light; said beam splitter being arranged in an area between said microlens array splitting the illumination light and said further microlens array; and said pinhole diaphragms of said pinhole diaphragm array being arranged out of the area between said microlens array splitting the illumination light and said further microlens array.  
         [0010]     In the new microscope the microlens array for splitting the illumination light is also arranged in the beam path of the sample light. To compensate for the effects of the microlens array on the sample light, a second equivalent microlens array is provided. In the new confocal microscope, the sample light thus passes through two microlens arrays. This means that the microlenses of the microlens array have to have good optical properties, to the end of the measuring points in the sample being imaged by the sample light without distortion. However, microlens arrays having optical properties which are sufficient for that are available. By using them, it is possible to arrange the beam splitter for separating the beam path of the illumination light and of the sample light captured in an inverse direction with regard to the illumination light between the microlens arrays. Particularly, if the ray bundle of the illumination light is a parallel ray bundle, this area is much less critical than the area between the microlens array and the pinhole diaphragm array which is used for arranging the beam splitter in the prior art. Particularly, the distance of both microlens arrays is not critical. So far as the ray bundle of the illumination light is a parallel ray bundle, this distance may theoretically even be unlimited because the sample light running in an inverse direction with regard to the illumination light is also formed into parallel partial ray beams by the microlens array splitting the illumination light. This already results from the fact that the optical path of the illumination light and of the sample light viewed from the sample is the same up to behind the first microlens array. The arrangement of both microlens arrays in the new confocal microscope is comparatively insensitive even with regard to other inaccuracies of the adjustment. The pinhole diaphragm array has additionally to be adjusted with regard to the microlens arrays, but in this step it is not necessary to care for any beam splitter arranged in between.  
         [0011]     Particularly with regard to the further microlens array, it is preferred, if all microlenses have the same focus length. This is not absolutely necessary with regard to the first microlens array used for splitting the illumination light. With microlenses of different focal lengths the sample can even be scanned in z-direction. By means of a same focal length of the further microlens array, however, these measuring points are imaged into one plane.  
         [0012]     Further, it is preferred, if the two microlens arrays are arranged in parallel to each other, the beam splitter deviating the ray bundle of the illumination light out of the beam path of the sample light. Whereas in the prior art, the illumination light essentially runs straight through the arrangement of the pinhole diaphragm array and the microlens array passing the beam splitter, in the new confocal microscope, the sample light preferably passes the beam splitter without deviation.  
         [0013]     Viewing from the sample, the pinhole diaphragm array may either be arranged in front of the microlens array for splitting the illumination light or behind the further microlens array in the new confocal microscope. In any case the pinhole diaphragm array is arranged on a side of one of the microlens arrays pointing away from the beam splitter. The pinhole diaphragm array may thus be directly connected with the respective microlens array over its entire plane. Preferred is an actual embodiment in which the microlens array and the pinhole diaphragm array are formed at two surfaces of one body of refractive material facing away from each other. In this way, a later adjustment of the pinhole diaphragm array with regard to the respective microlens array is not necessary. Instead, the position of the pinhole diaphragm array with regard to the microlens array is fixed by the common body of refractive material.  
         [0014]     In the preferred embodiment of the new confocal microscope, a scanning device is provided which synchronously moves both microlens arrays and the pinhole diaphragm array in parallel to their planes of main extension. The two microlens arrays and the pinhole diaphragm array are particularly provided as rotating discs, i.e. as wheels.  
         [0015]     To vary the effective size of the aperture of the pinhole diaphragms of the pinhole diaphragm array, a further diaphragm array corresponding to the first diaphragm array may be provided, which is arranged directly in front of or behind the first diaphragm array and which may be moved in parallel to the first diaphragm array. The maximum size of the common passageway cross-section of both pinhole diaphragm arrays is given when the pinhole diaphragm arrays coincide. Upon increasing movement with regard to each other, the size of the common passageway cross-section decreases so that the effective diaphragm aperture of the pinhole diaphragms of the pinhole diaphragm arrays decreases. For example, the diaphragm aperture may be maximized, when the new confocal microscope is used for a two-photon-excitation of the sample in which the spatial resolution in z-direction is already achieved for other reasons. Vice versa, the diaphragm apertures may be minimizes, when the spatial resolution in z-direction should be particularly high in a special case.  
         [0016]     With regard to the pinhole diaphragms of each microlens array it is preferred, if there are square, the pinhole diaphragms being moveable with regard to each other in the direction of a square diagonal starting from a full coincidence. The common passageway cross-sections are then always square with decreasing size of the squares. As long as the diaphragm aperture is in total smaller than the focus cross section of the partial ray beam focussed on the diaphragm aperture, the shape of the limitation of the passageway cross-section does not matter.  
         [0017]     The adjusting labour required by the new confocal microscope is further reduced in that a beam splitter is used as the beam splitter, which lets the sample light pass through without offset, or which is compensated for offset. These properties of the beam splitter have only to be present for partial ray beams which are totally or essentially parallel and in form of which the sample light is present between the two microlens arrays. Thus, the beam splitter may for example be a beam splitter cube, the additional cube boundary surfaces besides the beam splitting diagonal surface of which would be rather critical in a confocal microscopy according to the prior art. An offset compensation for a semi-transmitting mirror may, for example, be realized by an additional optical plate with plane-parallel surfaces and with a tuned thickness being arranged at an angle of 90° with regard to the semi-transmitting mirror. With regard to the parallel partial beams of the sample light in the area of the beam splitter the different surfaces of the optical arrangement between the two microlens arrays are also not critical here. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0018]     The invention can be better understood with reference to the following drawings. The components in the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the present invention. In the drawings, like reference numerals designate corresponding parts throughout the several views.  
         [0019]      FIG. 1  is a strongly simplified overview over the units of a first embodiment of the confocal microscope.  
         [0020]      FIG. 2  shows an actual embodiment of the microscope according to  FIG. 1  being a fluorescence light microscope.  
         [0021]      FIG. 3  is a view on a microlens wheel of the microscope according to  FIG. 2 .  
         [0022]      FIG. 4  shows different possibilities of z-direction scanning a sample with the microscope according to  FIG. 2 .  
         [0023]      FIG. 5  shows an actual embodiment of the microscope according to  FIG. 1  being a reflection light microscope.  
         [0024]      FIG. 6  shows a variant of the microscope according to  FIG. 2 .  
         [0025]      FIG. 7  shows a diagram of the realization of a pinhole diaphragm array with a variable diaphragm aperture.  
         [0026]      FIG. 8  shows a second basic embodiment of the confocal microscope; and  
         [0027]      FIG. 9  shows a detail of an alternative embodiment with regard of a microscope according to  FIG. 8 . 
     
    
     DETAILED DESCRIPTION  
       [0028]      FIG. 1  shows the basic construction of a confocal microscope  1  for simultaneously measuring a sample  2  in a plurality of measuring points  3 . In each of the measuring points, the sample  2  is illuminated by illumination light  4 . The illumination light  4  comes from a light source  5  typically being a laser  6 . The illumination light coming from the laser  6  is a parallel ray bundle  7 . The parallel ray bundle  7  is deviated by a beam splitter  8  towards a microlens wheel  9 . The microlens wheel  9  has a microlens array  10  consisting of a plurality of microlenses  11  arranged side by side. The microlens array  10  splits the ray bundle  7  into a plurality of convergent partial ray bundles  12  only one of which being depicted here. Via a tube lens  13  and a microscope objective  14  each partial ray bundle  12  is focussed in one of the measuring points  3 . The tube lens  13  and the microscope objective  14  are common to all partial ray bundles  12 . In the measuring points  3  the sample  2  is excited for the emission of sample light, if the microscope  1  is a fluorescence microscope, or the sample reflects or scatters the illumination light in the measuring points  3 . In any case, the sample light  15  gets to the beam splitter  8  on the same way through the microscope objective, the tube lens  13  and the microlenses  11  of the microlens wheel  9  as the illumination light  4  but in an opposite direction. The beam splitter  8  being a beam splitter cube  16  here transmits the sample light, and thus separates the sample light  15  from the illumination light  4 . In the area of the beam splitter  8 , the sample light  4  consists of parallel partial ray bundles  17  which reach a second microlens wheel  18 . The second microlens wheel  18  has a microlens array  19  made of microlenses  20  which are arranged in equivalent positions to the microlenses  11  of the microlens wheel  9 . The microlenses  20  focus the partial ray bundles  17  onto pinhole diaphragms  21  of a pinhole diaphragm array  22  on a pinhole diaphragm wheel  23 . Each partial ray bundle  17  is exactly focussed into the diaphragm aperture of one pinhole diaphragm  21 . The pinhole diaphragm  21  is confocally arranged with regard to the respective measuring point  3  from which the sample light  15  originates. From the pinhole diaphragm  21  the sample light  15  gets to a detector  27  through a lens  24 , via a beam splitter  25  and through a further lens  26 , which detector may be a camera  23 , or directly into the eye  30  of a person viewing the sample  2  with the microscope  1  through the lens  24 , the beam splitter  24  and an ocular  29 . Upon synchronously rotating the microlens wheels  9  and  18  and the pinhole aperture wheel  23  about a common rotation axis  31 , resulting into scanning the sample  2  with the measuring points  3 , a two-dimensional image of the sample  2  is produced. For realizing the adjustment of the microlens wheels  9  and  18  with regard to each other, they may only have a connection  32  to each other in the area of the rotation axis  31 , because the beam splitter  3  is arranged between the microlens wheels  9  and  18 . The microlens wheel  18 , however, may also have a connection  33  to the pinhole diaphragm wheel  23  in the area of its circumference. Thus, there may be a particular stabile unit consisting of the microlens wheel  18  and the pinhole diaphragm wheel  23 .  
         [0029]     The more concrete picture of the microscope  1  according to  FIG. 2  relates to the embodiment of the microscope  1  being a fluorescence light microscope and comprises various additional optical elements. In contrast to  FIG. 1 , a mirror  34  which may be tilted into the beam path of the sample light  15  is provided instead of the beam splitter  25 , which mirror  34  either lets the sample light  15  pass to the eye  30  or deviates the sample light  15  towards the detector  27 . As an additional detail,  FIG. 2  comprises a telescope  35  for expanding the illumination light  4  coming from the laser  6 . The expanded illumination light  4  passes through a colour filter  36 , and, then, the boundary area of the illumination light  4  is cut off with a diaphragm  37 . The core area forms the parallel ray bundle  7  which is incident on the beam splitter  8 . The beam splitter  8  is a dichroitic beam splitter cube  38  here, which deviates light with a wave length of the illumination light  4  and which lets light with the wave length of the sample light  15  pass through. Correspondingly, a colour filter  39  is arranged in the beam path of the sample light  15 . Further,  FIG. 2  shows the important detail that the microlens wheel  18  and the pinhole diaphragm wheel  23  are combined to a unit being continuous in the direction of the beam path of the sample light  15 . Actually, a body  40  of refractive material is provided, the microlenses  20  being formed at the one surface of which, and the pinhole diaphragms  21  being formed at the opposite surface of which. Thus, a defined spatial arrangement of the pinhole diaphragms  21  is given with regard to the microlenses  20 , in which the pinhole diaphragms  21  are exactly at the focus of the microlenses  20 . Adjusting the rotatable wheels  9 ,  18  and  23  with regard to the fixed units of the microscope  1  is thus reduced to adjusting two units. Here, the distance of both microlens wheels  9  and  18  is not critical, because the illumination light  15  has the form of parallel partial ray bundles  17  here.  
         [0030]      FIG. 3  shows a front view onto the microlens wheel  9 . Here, the microlens array  10  and its arrangement of microlenses  11  are well visible. Further, a rotational direction of the microlens wheel  9  is indicated by an arrow  41 . The single microlenses  11  are arranged on spiral paths, one of which being high lightened by a dashed line  42 . In the area of the microlens array  10 , the sample  2  is fully two-dimensionally scanned by turning the microlens wheel  9 .  
         [0031]      FIG. 4  sketches different possibilities to additionally scan the sample  2  in z-direction, i.e. in the direction of the beam path of the microscope  1 . To this end, the focus lengths A of the microlenses  11  of the microlens wheel  9  may be different. The microlens wheel  9  may also, as a whole, be moved in the direction of a double arrow B in the direction of its rotation axis  31  to achieve scanning the sample  2  in z-direction. Further possibilities are moving a lens  43  of a pair of lenses  43  and  44  in the direction of a double arrow C. Of course, the sample  2  may also be moved in the direction of a corresponding double arrow D in z-direction. Further,  FIG. 4  clearly indicates the arrangement of the pinhole diaphragms  21  at the focus points of the microlenses  20  of the microlens wheel  18 . The parallel partial ray bundles  17  of the sample light  15  are focussed by the microlenses  20  at these focus points. At the same time, the pinhole diaphragms  21  are confocally arranged with regard to the measuring points on the sample  2 .  
         [0032]     The microscope  1  according to  FIG. 5  is constructed as a reflection or scatter light microscope in which the sample light  15  is illumination light  4  reflected by the measuring points  3  of the sample  2  so that the sample light has the same or at least nearly the same wavelength as the illumination light. Correspondingly, other means for separating the sample light  15  and the illumination light  4  than in the microscope  1  depicted in  FIG. 2  are provided here. The beam splitter  8  is a polarization beam splitter cube  45  here, which deviates illumination light  4  linearly polarized in a certain direction towards the sample  2 . A lambda-quarter-plate  46  arranged between the tube lens  13  and the microscope objective  14  changes the polarization of the illumination light  4  into a circular polarization of a certain rotation direction. Because of the reflection of the illumination light  4  in the measuring points  3 , the sample light  15  coming back from the sample  2  has a phase altered by 180°, i.e. a circular polarisation having an opposite rotation direction with regard to the illumination light  4 , which circular polarization is amended by the lambda-quarter-plate  46  into a linear polarization having a direction turned by 90° as compared to the illumination light  4  prior to the lambda-quarter-plate. Thus, the sample light  5  passes through the polarisation beam splitter cube  45  unaffected. The colour filters  36  and  37  are not provided in the embodiment of the microscope according to  FIG. 5 . Further, the polarization elements  45  and  46  are not essential for the function of the reflection microscope according to  FIG. 5 , but they enhance the achievable brightness contrast.  
         [0033]      FIG. 6  shows the microscope  1  which is again constructed as a fluorescence microscope and based on a dichroitic beam splitter cube  38 . Here, a further beam splitter cube  47  and a deviation prism  48  are additionally provided between the microlens wheel  9  and the microlens wheel  18 . These are also dichroitic units which are topped by two colour filters  39 ′ and  39 ″. In this way, sample light of different wave lengths coming from the sample  2  may be separated between the two microlens wheels  9  and  18  and be imaged through different areas of the microlens array  19  and of the pinhole diaphragm array  22  onto the detector  17 . Further, a telescope  49  is connected in series to collect the separated colours of the sample light to such an extent that they may be projected onto the detector  27  side by side. The detector  27  thus comprises an image with two or more areas corresponding to different colours of the sample light.  
         [0034]      FIG. 7  is a diagram with regard to the possibility to vary the effective free passageway cross-section of the pinhole diaphragm array  22  and thus of the diaphragm aperture of the confocal pinhole diaphragms. To this end, a further pinhole diaphragm array  52  consisting of pinhole diaphragms  53  is provided, the in-plane arrangements of the pinhole diaphragms  51  and  53  of the pinhole diaphragm arrays  52  and  52  being the same, but may be moved with regard to each other. The free passageway cross-section  54  results from the coincidence of the diaphragm apertures of one pinhole diaphragm  21  and one pinhole diaphragm  53 . Actually, the diaphragm apertures of the pinhole diaphragms  51  and  53  are each delimited by squares here, and it is intended to move them with regard to each other in direction of a square diagonal. In the middle of  FIG. 7  the arrangement of the pinhole diaphragm arrays  22  and  52  with regard to each other is depicted, which results into free passageway cross-sections  54  of middle size. By moving the pinhole diaphragm arrays  22  in the direction of arrow  55 , which actually corresponds to turning the two pinhole diaphragm wheels with regard to each other in an arrangement of both pinhole diaphragm arrays  22  and  52  on pinhole diaphragm wheels, the coincidence of the pinhole diaphragms  21  and  53  is finally lost, which case is depicted on the right hand side of  FIG. 7 . Here, there is no free passageway cross-section  54  left. By movement in the opposite direction of an arrow  56 , the free passageway cross-sections  54  increase until the pinhole diaphragms  21  and  53  are exactly coincident, which case is depicted on the left hand side of  FIG. 7 . In any case, the free passageway cross-section  54  is smaller than the focus area  57  projected onto the respective pinhole diaphragms  21  and  53 , so that the shape of the limitation of the free passageway cross-section  54  by means of a square is not critical. Instead, the shape of the pinhole diaphragms  21  and  53  according to  FIG. 7  is advantageous as even in moving them with regard to each other the free passageway cross-section  54  is always delimited by a square and only varies in size.  
         [0035]      FIG. 8  shows a variant of the embodiment of the microscope  1  according to  FIG. 2 , the pinhole diaphragm array  22  on the pinhole diaphragm wheel  53  being arranged in front of the microlens array  9  instead of behind the microlens array  18 . In this way, the illumination light  4  also passes through the pinhole diaphragms  21 . Further, the pinhole diaphragm array  22  is comparatively farer away from the detector  27  or the eye  30 . However, there are no principal differences in the function of the microscope  1 . In this embodiment there may also be a body  40 , the microlenses  11  of the microlens array  10  of the microlens wheel  9  are formed at the one surface of which, and the pinhole diaphragms  21  of the pinhole diaphragm array  21  are positioned at its opposite surface.  
         [0036]      FIG. 9  sketches the use of a dichroitic mirror  50  between the microlens wheels  9  and  18  instead of the beam splitter cube  16  in the microscope according to  FIG. 8 . To compensate for the resulting beam offset caused by the dichroitic mirror  50  with regard to the sample light  50  passing through, an optical plate  51  having plane-parallel surfaces and a tuned thickness is provided in an orthogonal direction with regard to the dichroitic mirror  50 . The optical plate  51  reduces the beam offset caused by the dichroitic mirror  50  down to zero.  
       LIST OF REFERENCE NUMERALS  
       [0000]    
       
           1  microscope  
           2  sample  
           3  measuring point  
           4  illumination light  
           5  light source  
           6  laser  
           7  ray bundle  
           8  beam splitter  
           9  microlens wheel  
           10  microlens array  
           11  microlens  
           12  partial ray bundle  
           13  microscope objective  
           14  tube lens  
           15  sample light  
           16  beam splitter cube  
           17  partial ray bundle  
           18  microlens wheel  
           19  microlens array  
           20  microlens  
           21  pinhole diaphragm  
           22  pinhole diaphragm array  
           23  pinhole diaphragm wheel  
           24  lens  
           25  beam splitter  
           26  lens  
           27  detector  
           28  camera  
           29  ocular  
           30  eye  
           31  rotation axis  
           32  connection  
           33  connection  
           34  mirror  
           35  telescope  
           36  colour filter  
           37  diaphragm  
           38  dichroitic beam splitter cube  
           39  colour filter  
           40  body  
           41  arrow  
           42  dashed line  
           43  lens  
           44  lens  
           45  polarization beam splitter  
           46  lambda-quarter-plate  
           47  beam splitter cube  
           48  deviation prism  
           49  telescope  
           50  dichroitic mirror  
           51  plate  
           52  pinhole diaphragm array  
           53  pinhole diaphragm  
           54  passageway cross-section  
           55  arrow  
           56  arrow  
           57  focus area