Patent Document

RELATED APPLICATIONS 
   This application claims priority of the German patent application 10 2004 034 847.2 which is incorporated by reference herein. 
   FIELD OF THE INVENTION 
   The invention concerns a microscope with an adjustable optical element. 
   BACKGROUND OF THE INVENTION 
   U.S. Pat. No. 4,678,291 discloses an optical apparatus for microscopes. The apparatus makes possible a rapid changeover between two different observation methods of the microscope. The apparatus encompasses a dovetail guide on which the Bertrand lens is guided. The Bertrand lens can be shifted in the beam path by way of a threaded spindle. The threaded spindle makes possible accurate positioning of the Bertrand lens. It must be noted here, however, that the Bertrand lens is continuously positioned in the beam path, and in the case of the apparatus described here no provision is made for pivoting the Bertrand lens in and out. 
   GB Patent 590,665 describes an improvement for microscopes, in which the Bertrand lens is provided in the beam path of the microscope between the objective and the eyepieces. The Bertrand lens is secured at opposite ends in a ring-like holding element, and the holding element can be pivoted into the beam path of the microscope. Also associated with the Bertrand lens is a diaphragm that, in an embodiment of the invention, can be adjusted from outside. Adjustments of the diaphragm associated with the Bertrand lens can be performed irrespective of the position of the annular holder, i.e. an adjustment is possible even when the Bertrand lens is not in the beam path. 
   SUMMARY OF THE INVENTION 
   It is the object of the invention to create a microscope in which an alignment opening in the stand is closed off in dust- and light-tight fashion, and opens only when an element requiring alignment is placed in the beam path of the microscope. A further object of the invention is to prevent damage to optical components in the interior of the microscope that might result from improper use of tools through holes that might be present in the microscope. 
   The aforesaid object is achieved by way of a microscope comprising: an optical element, wherein the optical element is displaceable into an optical axis determined by the microscope, the microscope further comprises a stand and a tube which can be connected to the stand; an adjustment element is connected with the optical element, wherein the optical element and the adjustment element are arranged in the interior of the stand; and a closure element is provided that enables access to the adjustment element when the optical element is positioned in the optical axis of the microscope. 
   The invention has the advantage that the optical element and the adjustment mechanism are arranged in the interior of the stand. Also provided is a closure element that enables access to the adjustment mechanism when the optical element is arranged in the beam path of the microscope. 
   The optical element is arranged on a slider movable in the horizontal direction. The optical element is a Bertrand lens. Embodied in the stand of the microscope is an opening behind which the closure element is provided. In addition to the optical element—which, as already mentioned, is a Bertrand lens—at least one prism is additionally arranged on the slider, the slider being actuatable from outside the stand of the microscope. The adjustment mechanism is an alignment screw that is actuatable through the opening in the stand by means of a tool. 
   The closure element is impinged upon by a tension spring. The adjustment element actuates the closure element in order thereby to enable access to the adjustment element. The tension spring acts on the closure element in such a way that access to the adjustment element is blocked when the adjustment element is not coacting with the closure element. 
   The closure element is a plate-shaped component that is mounted pivotably about a shaft. The plate-shaped component possesses a rounded protrusion on the side opposite to the opening embodied in the stand. In addition, a first and a second parallel rib are embodied on either side of the shaft, the two being separated by a trench. The first rib is longer than the second rib. The adjustment element of the optical component coacts with the first rib of the closure element, and as a result the closure element is pivoted about the shaft in such a way that the opening in the stand of the microscope aligns with an adjustment screw in the closure element. 
   The part of the microscope stand that is embodied with the opening is additionally equipped with a cover. The cover also serves, among other purposes, to enclose any structural elements of the stand, and to impart to the entire microscope a smoother appearance and a smoother outer skin which is substantially easier to clean and less susceptible to soiling. 
   A push/pull rod with which the slider having the optical components is actuatable projects from the microscope stand. By pulling or pushing, the particular optical component required can be introduced into the beam path of the microscope. In a preferred embodiment of the invention, the tube of the microscope possesses a lateral port. The push/pull rod projects out of the microscope stand in the region of the lateral port. Arranged on the slider, in addition to the optical component, is at least one prism that, by displacement of the slider, can be introduced into the beam path of the microscope, thus shifting the beam path to the port. 
   The microscope can be embodied as an inverted microscope. 
   Further advantageous embodiments of the invention may be inferred from the dependent claims. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The subject matter of the invention is depicted schematically in the drawings and will be described below with reference to the Figures, in which: 
       FIG. 1  is a perspective view of an inverted microscope into which the invention is integrated; 
       FIG. 2  is a frontal view of the region of the inverted microscope around the tube; 
       FIG. 3  is an enlarged depiction of the region of the inverted microscope around the tube, the cover on the end surface of the inverted microscope having been removed; 
       FIG. 4  is an enlarged depiction of the region of the inverted microscope around the tube, the cover on the end surface of the inverted microscope having been removed and the position of the closure element being such that access to the adjustment element is possible; 
       FIG. 5  is a plan view of the slider and the closure element that are arranged in the interior of the microscope stand; 
       FIG. 6  is a plan view of the slider and the closure element that are arranged in the interior of the microscope stand, the closure element having a position such that access to the adjustment element is enabled; 
       FIG. 7  is an enlarged depiction of the closure element which is in the closed position; and 
       FIG. 8  is an enlarged depiction of the closure element which is in the open position. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1  shows an embodiment of microscope  1  in which the present invention is implemented. As depicted here, microscope  1  is an inverted microscope, which in no way is to be construed as a limitation of the invention. It is self-evident to anyone skilled in the art that the present invention can also be used in an upright microscope. Microscope  1  comprises a base stand part  3  that supports an illumination stand part  5 . Sitting on base stand part  3  is a revolving nosepiece  7  with which the user can pivot various objectives (not depicted) into the beam path of the microscope in motorized fashion. The end of base stand part  3  facing toward the user carries a tube  9  that is equipped with an eyepiece  10 . A port  11  is also mounted on tube  9 . Base stand part  3  comprises a first lateral surface  3   a , a second lateral surface  3   b , and a front surface  3   c  facing toward the user. Distributed over first lateral surface  3   a , front surface  3   c , and second lateral surface  3   b  are multiple actuation elements  12  with which the user can actuate motorized microscope functions. Base stand part  3  possesses a wedge-shaped extension  14  facing toward the user. Inset into wedge-shaped extension  14  is a display  15  with which the user can read off the settings of microscope  1 . 
     FIG. 2  is a frontal view of microscope  1  in which not all parts of microscope  1  are depicted. Front surface  3   c  is equipped with a cover  17 . Tube  9  is set in place above cover  17 . In the embodiment depicted here, tube  9  possesses an eyepiece  10  and a port  11 . Port  11  is equipped with a flange  18  on which, for example, a camera can be placed. Also provided on port  11  is a push/pull rod  19  with which, for example, a beam path  20  of microscope  1  can be switched over to port  11 . Flange  18  of port  11  likewise defines a beam path  21 . The elements in the interior of microscope  1  that are actuated by push/pull rod  19  are explained in more detail in  FIGS. 5 and 6 . Embodied in cover  17  that is mounted on front surface  3   c  of microscope  1  is an opening  25  through which access to the interior of microscope  1  is possible. 
     FIG. 3  is a detail view of tube  9  that can be placed onto microscope  1 . As already mentioned, the tube possesses an eyepiece  10  with which the user can visually observe or view the image of a specimen. Tube  9  and microscope  1  define optical axis  20 . A port  11  is also mounted on tube  9 . Port  11  furthermore possesses a flange or thread or bayonet closure onto which a camera (not depicted) can be attached. Flange  18  likewise defines an optical axis  21 . A movable push/pull rod  19  is provided on port  11 . Push/pull rod  19  acts on a slider (see  FIGS. 5 and 6 ), provided in tube  9 , with which a closure element  26  is actuatable. Tube  9  possesses, in the region of closure element  26 , a cutout  27  which enables access to closure element  26  from outside tube  9 . Tube  9  possesses a tubular extension  28  and several mounting screws  29  that coact with base stand part  3  of microscope  1 , in order to ensure secure mounting of tube  9  on base stand part  3 . As is evident from  FIG. 3 , optical axis  20  of the microscope extends centrally through tubular extension  28 . 
     FIG. 4  is a frontal view of tube  9  according to the present invention, in which push/pull rod  19  has been pulled out of port  11 . As a result of the displacement of push/pull rod  19 , closure element  26  is also displaced in the interior of tube  9 . The displacement of closure element  26  enables access to an adjustment element  30 . Adjustment element  30  is a screw that can be actuated using a tool (not depicted). Adjustment element  30  acts on an optical element that is arranged on a slider. The optical element is thereby introduced into optical axis  20  of the microscope, and can be aligned more accurately within optical axis  20  by means of screw  30 . 
     FIG. 5  is a detail view of a slider  40  in the interior of tube  9 . Slider  40  carries multiple optical elements  41 . In the embodiment depicted in  FIG. 5 , three optical elements  41  are arranged on slider  40 . One optical element can be, for example, a prism, and another optical element  41  is a Bertrand lens. A further prism  43 , which receives the light beam from the prism arranged on the slider and deflects it into optical axis  21  of flange  18  of port  11 , is arranged in port  11 . Optical element  41 , which is the Bertrand lens, is connected to an adjustment element  45 . Also arranged in the interior of tube  9  is a closure element  26  that is mounted rotatably about a shaft  47 . Slider  40  is partially surrounded by a housing wall  50  of tube  9 . Cutout  27  through which closure element  26  partially protrudes is embodied in housing wall  50 . Shaft  47  of closure element  26  is also supported in housing wall  50 . A pin that provides an engagement point for a tension spring  52  is arranged in the interior of housing wall  50 . A further engagement point for tension spring  52  is embodied on closure element  26 . 
     FIG. 6  shows the position of push/pull rod  19  in which the Bertrand lens is positioned in the optical axis of microscope  1  and of tube  9 . Attached to the Bertrand lens is an adjustment element  45  that, in this position, coacts with closure element  26 . Tension spring  52  is also tensioned between pin  51  and adjustment element  26 . Adjustment element  26  is embodied with a trench  58  that, in the position depicted in  FIG. 6 , aligns with opening  25  in cover  17  for tube  9  and for end surface  3   c  of the microscope. 
     FIG. 7  is a detailed depiction of closure element  26  in the closed position. Closure element  26  is embodied in the form of a plate-shaped component. Closure element  26  is mounted rotatably about a shaft  47 . Closure element  26  has a rounded protrusion  60  on the side that is opposite to opening  25  in cover  17 . A first rib  61  and a second rib  62  are shaped on either side of shaft  47  of closure element  26 . First rib  61  and second rib  62  are separated from one another by trench  58 . Engagement point  63  for tension spring  52  is embodied on closure element  26 . Adjustment element  45  encompasses a bushing  70  in which adjustment screw  30  is guided. Bushing  70  of adjustment element  45  coacts with second rib  62 , which is longer than first rib  61 . 
     FIG. 8  is likewise an enlarged depiction of closure element  26  that coacts with adjustment element  45 . When push/pull rod  19  has been pulled out of tube  9  or port  11 , bushing  70  comes into working engagement with second rib  62 , with the result that closure element  26  is rotated about shaft  47 . The trench configured in the closure element now aligns with opening  25  in cover  17  and with adjustment screw  30  provided in bushing  70  of adjustment element  45 . As already mentioned, in this position tension spring  52  is tensioned, and thus exerts a return force on closure element  26 . When adjustment element  45  is no longer in a working relationship with closure element  26 , the tensioned tension spring  52  then exerts a return force on the adjustment element and closes off opening  25  embodied in cover  17 . In the position depicted in  FIG. 8 , end  75  of adjustment element  45  facing away from adjustment screw  30  coacts with the Bertrand lens (optical element  41 ). Displacement of adjustment screw  30  causes end  75  of the adjustment element to press onto optical element  41 , positioning the latter correspondingly in the optical axis of microscope I and tube  9 . Also shown in  FIG. 8  is cutout  27  in housing wall  50  of tube  9 , through which closure element  26  engages and in which closure element  26  is free to pivot. 
   The invention has been described with reference to a particular embodiment. It is self-evident, however, that changes and modifications can be made without thereby leaving the range of protection of the claims below.

Technology Category: 3