Abstract:
A tilting mirror for optical devices is described, in particular microscopes, which is retained in precision-mounted fashion in a carrier in a working position. For that purpose, the carrier has a three-surface support.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
   The inventor claims priority of the German patent application 101 28 965.0 filed on Jun. 15, 2001, which is incorporated by reference herein in its entirety. 
   BACKGROUND OF THE INVENTION 
   The invention relates generally to the field of optical beam deflection in an optical device, and more particularly, to a tilting mirror for selectable switching into and out of an optical beam path of an optical device. 
   Arrangements are known in which a mirror is tilted in order to direct a beam on different paths through a multifunctional optical device. With a tilting mirror in a microscope, for example, the radiation proceeding from the specimen can be conveyed selectably to the observer&#39;s eye or to a documentation medium. If a mirror switches between only two light paths, then arrangements are selected, for example, in which in the one position the mirror is arranged in the beam path in order to deflect the light (working position), and in the second position is placed outside the light path. Such arrangements require high angular accuracy and reproducibility in terms of the mirror location in the working position. 
   DE Patent 2,029,850, for example, teaches a photometer for microscopes in which a reciprocating magnet brings about the pivoting into and out of the beam path. 
   Another DE Unexamined Application 2,341,038 teaches a tilting mirror in the 45° position, which in that position blocks the vertical imaging beam path in a macro microscope and reflects into the eyepiece system a reflected-in beam path arranged at right angles thereto. 
   DE Unexamined Application teaches a microphotographic light measurement device in which a deflection mirror can be introduced into an optical beam path in such a way that the deflection mirror is slid into the working position by means of a manually actuable carrier. 
   Also known are solutions in which a pivotable holder is mounted on a mechanical tilting shaft which receives the mirror on its back side or side surface. Accurate angular deflection is defined by the arrangement of the tilting shaft and by contact of the mirror or the holder against a stop. The stop and/or the tilting shaft are configured alignably so that the most accurate possible angular deflection can be set even for different mirror thicknesses and manufacturing tolerances. To ensure that the tilting mirror can return to its original angular position after each tilt, stringent requirements are therefore placed on the bearing of the tilting shaft; in addition, the mirror position in the working position must be aligned. 
   SUMMARY OF THE INVENTION 
   It is therefore an object of the present invention to eliminate the aforesaid disadvantages of known designs and/or other problems found within the prior art, and to present a precision-mounted tilting mirror arrangement that can be produced economically and can be used in a wide variety of optical devices. 
   This object is achieved by a tilting mirror having a mount for selectable deflection or passage of a beam in an optical device wherein the tilting mirror is arranged on a carrier that comprises a three-surface support for precision mounting of the tilting mirror in the working position. 
   According to one aspect of the present invention, a tilting mirror having a mount for selectably deflecting or allowing passage of a beam in an optical device is provided, the tilting mirror being arranged on a carrier comprising at least a three surface support for precision mounting of the tilting mirror in a working position. 
   According to another aspect of the present invention, an optical alignment device is provided comprising a carrier member including a plurality of deflector supports projecting from a top surface, and a rotatable deflector coupled to the carrier member in such a way as to engage the plurality of deflector supports when positioned in a working position. 
   According to another aspect of the present invention, a method of deflecting beams in an optical device is provided comprising rotating a mirror from a propagation position to a working position, and supporting the mirror in the working position via a plurality of mirror supports on a carrier member. 
   According to another aspect of the present invention, an optical alignment device is provided comprising a carrier member including a plurality of deflector supports projecting from a top surface and lying substantially in the same plane, a rotatable deflector coupled to the carrier member in such a way as to engage the plurality of deflector supports when positioned in a working position, and at least one cylinder about which the rotatable deflector rotates. 
   Advantages of this tilting mirror according to the present invention include the aspect that only one plane, constituted by three precision-machined surface elements, is necessary for high positioning accuracy and reproducibility, and that alignment of the functional position is superfluous. A specially configured mechanical tilting shaft and a precise bearing system for such a shaft are not necessary. The demands in terms of design placed on the mechanism—i.e. on the stop geometry for limiting any lateral motions of the mirror—are not great. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention will now be described with reference to the Figures. 
       FIG. 1   a  is a block diagram of a tilting mirror according to an embodiment of the present invention; 
       FIG. 1   b  is a block diagram of a carrier belonging to the tilting mirror shown in  FIG. 1   a ; 
       FIG. 2  is an “exploded”side view of a tilting mirror in a working position according to an embodiment of the present invention; 
       FIG. 3   a  is a block diagram of a tilting mirror with associated carrier out of the working position according to an embodiment of the present invention; 
       FIG. 3   b  is a block diagram of a tilting mirror resting precisely at or on a carrier in the working position according to an embodiment of the present invention; 
       FIG. 4   a  is a block diagram of a tilting mirror according to an embodiment of the present invention; 
       FIG. 4   b  is an “exploded”side view of the tilting mirror shown in  FIG. 4   a  with a carrier part indicated according to an embodiment of the present invention; 
       FIG. 5   a  is a plan view of a tilting mirror with a carrier located below it according to an embodiment of the present invention; 
       FIG. 5   b  is a side view of the tilting mirror shown in  FIG. 5   a  with the carrier part resting precisely in the three-surface support according to an embodiment of the present invention. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Reference will now be made in detail to exemplary embodiments of the invention. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. 
     FIG. 1   a  shows a tilting mirror  1  that has on its underside a mirror-like reflective region  2 . Located at its end region is a cylindrical part  4  whose axis coincides with tilt axis  14  of tilting mirror  1 . It is evident that cylindrical part  4  is “extended”on either side of tilting mirror  1 , thereby forming projections  4   a  and  4   b . Cylindrical part  4  can be a separate piece apart from and added to tilting mirror  1 , or can be integrally formed with tilting mirror  1 . This tilting mirror can be pivoted or tilted about its axis  14  with, for example, a manually actuable lever  3 . 
   This tilting mirror arrangement corresponds to carrier  5  depicted in  FIG. 1   b , which is configured as a plate that has an opening  8  for the incident beam that is reflected or allowed to pass. Also evident are precision surface elements  6   a-   6   c , surface elements  6   b  and  6   c  constituting precision support surfaces for projections  4   a  and  4   b , respectively, of cylindrical part  4 . Located at the other edge region of carrier  5  is a precision stop surface  6   a , the design being executed in such a way that surfaces  6   a  and  6   b  and  6   c  together implement a “three-surface support” 6   a-   6   c  for tilting mirror  1 . To protect the tilting mirror from unintentional lateral offsetting, support surfaces  7   a-   7   d  are located in a right-angled arrangement with respect to precision support surfaces  6   b  and  6   c . 
     FIG. 2  depicts a working position of tilting mirror  1  in an exploded view. It is evident that the underside of tilting mirror  1  having reflective region  2  lies on a fictitious plane E 1 , and cylindrical part  4  and its projections  4   a  and  4   b also lie on plane E 1 . In mathematical terms, this means that the extension of fictitious plane E 1  tangentially touches the circular cross section of cylindrical part  4 . This configuration can be achieved in precise fashion with a single production operation. For example, cylindrical part  4  and tilting mirror  1 , resting on a common support, can be immovably joined to one another. This can be done, for example, by adhesive bonding, cementing, or welding. On the other hand it would also be possible to configure tilting mirror  1  in one piece together with cylindrical part  4 , the underside of the tilting mirror being removed in plane-parallel fashion, for example by precision material-removing machining or injection molding, until the two parts ( 1  and  4 ) come to rest on fictitious plane E 1 .  FIG. 2  shows the columnar precision stop surface  6   a  and precision surface element  6   c , which conceals the associated surface element  6   b . It is evident that the surfaces of precision surface elements  6   a-   6   c  also lie in one fictitious plane E 2 . As already mentioned, in the working position of the tilting mirror these two fictitious planes E 1  and E 2  coincide, so that E 1 ≡E 2 . 
     FIG. 3   a  shows tilting mirror  1  together with its carrier  5  in a non-working position, so that beam  13  can pass unimpeded through opening  8 . 
   In  FIG. 3   b , tilting mirror  1  is in the working position, so that incident beam  9  is reflected at reflective region  2  and is deflected as reflected beam  10 . The Figure shows in purely schematic fashion that a force vector  11  acts on lever  3  and brings about the precise tilting of tilting mirror  1 . The force presses against the three surface elements  6   a-   6   c . To switch tilting mirror  1  out, what acts instead of the force  11  is a counterforce  12  (the corresponding force vector  12 ) whose direction of action lies well outside the supporting triangle formed by surfaces  6   a  through  6   c . In order to switch in and maintain the working position of tilting mirror  1 , a force is exerted on lever  3  such that vector  11  intersects the support plane of tilting mirror  1  inside the three support points or support surfaces  6   a-   6   c . If tilting mirror  1  is to be moved out of its working position (as depicted in  FIG. 3   a ), the direction of action of the force is modified in such a way that its vector  12  intersects the supporting plane well outside the triangle formed by the three aforesaid points or surfaces  6   a-   6   c . As a result, tilting mirror  1  is moved away from the supporting three-surface plane; advantageously, the travel relative to two of the three regions to be supported is limited, so that the tilting mirror executes a kind of rolling or tilting motion. Any lateral displacement that occurs in this context in some circumstances is not detrimental in terms of function, and is effectively limited by suitable means, for example lateral projections or recesses on the tilting mirror and stop surfaces opposite them on the carrier part. 
     FIG. 4   a  depicts a minor variation of tilting mirror  1 , or more precisely a variation of the projections of cylindrical part  4 . It is evident that cylindrical extensions  4   c  and  4   d  have flattened areas  4   c ′and  4   d ′. These flattened areas lie in coplanar fashion in plane E 1  together with the underside of tilting mirror  1 . This is illustrated in  FIG. 4   b . This variant of the tilting mirror design has the advantage in terms of production engineering that plane E 1  can be created with a single material-removing precision machining operation. Flattened regions  4   c′  and  4   d′ merely represent narrow “lands”, so as not to impair the translational or tilting or rolling operation in a manner untypical of the motion. 
     FIGS. 5   a  and  5   b  depict a further embodiment of a tilting mirror  1   a  and of the corresponding carrier.  FIG. 5   a  shows tilting mirror  1   a  in a plan view, while the actual principal portion of the carrier located below it is not visible. Instead, carrier parts  5 a are pivot-mounted on either side onto the actual carrier. It is evident that these are angled arm-shaped carrier parts  5   a  that carry a cylindrical stop and roller element  5   b  at or on each of their end regions. This can be one continuous cylindrical element. It is also possible to provide two cylindrical sub-elements instead of one integral cylindrical element  5   b . 
     FIG. 5   b  is a side view along section {overscore ( Vb—Vb )} of  FIG. 5   a . It is evident that tilting mirror has in its end region a recess  15  that can be designed, for example, as a continuous groove. This groove receives stop and roller element or elements  5   b .  FIG. 5   b  shows that in the working position, tilting mirror  1   a  is positioned so that the upper part of recess  15  does not contact element(s)  5   b . This therefore ensures that tilting mirror  1   a  rests precisely only at or on a three-surface support  6   a-   6   c . The function of cylindrical element  5   b  is to serve as a stop and roller element as tilting mirror  1   a  is brought out of the working position. The cross-sectional shape of recess  15  can exhibit a number of variants. In this variant embodiment of tilting mirror  1   a , precision support surfaces  6   b  and  6   c  are configured in such a way that they are rounded off on their portion facing toward stop and roller element  5   b . This improves the combined translational, tilting, and rolling operation of tilting mirror  1   a . 
   It is of course also possible to provide a number of further variants for the tilting of tilting mirror  1   a . For example, it would be conceivable for the tilting mirror to have, instead of a continuous recess, merely two blind holes in its rear region, into which corresponding pegs (i.e. cylindrical parts) of carrier  5  engage. 
   It is also possible for the actual carrier  5  and carrier parts  5   a  and  5   b  to be configured integrally. 
   Suitable materials for the tilting mirror with integrated cylindrical parts  4 ,  4   c ,  4   d ,  4   c′ , and  4   d′ and for tilting mirror  1   a  and/or for carrier  5  inclusive of carrier parts  5   a  and  5   b  are glass, glass ceramic, or ceramic material. 
   The advantages of the present invention are that only one plane (E 1 ≡E 2 ) constituted by three precision-machined surface elements is required for high positioning accuracy and reproducibility, and that subsequent alignment of the functional position is superfluous. A specially configured mechanical tilting shaft and a precise bearing system for such a shaft are not necessary. No substantial design demands are required on the mechanism (i.e. the stop geometries) in order to limit any lateral motions of the tilting mirror. 
   The foregoing description of various embodiments of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed, and modifications and variations are possible in light of the above teachings or may be acquired from practice of the invention. The embodiments were chosen and described in order to explain the principles of the invention and its practical application to enable one skilled in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims appended hereto, and their equivalents. 
   
     
       
             
           
             
             
           
         
             
                 
             
             
               FIGURE LABELS 
             
             
                 
             
           
           
             
                 
             
           
        
         
             
               1, 1a 
               Tilting mirror 
             
             
               2 
               Reflective region of (1), (1a) 
             
             
               3 
               Lever 
             
             
               4 
               Cylindrical part of (1) 
             
             
               4a, 4b 
               Projections of (4) 
             
             
               4c, 4d 
               Cylindrical extensions on (1) 
             
             
               4c′, 4d′ 
               Flattened region(s) of (4c), (4d) 
             
             
               5 
               Carrier for (1) 
             
             
               5a, 5b 
               Carrier part(s) for (1a) 
             
             
               5a 
               Angled arm-shaped carrier part(s) for (5b) 
             
             
               5b 
               Cylindrical stop and roller elements for (1a) 
             
             
               6a-6c 
               Precision surface element(s) 
             
             
               6a 
               Precision stop surface 
             
             
               6b, 6c 
               Precision support surface(s) 
             
             
               7a-7d 
               Support surface(s) 
             
             
               8 
               Opening for beam path (9), (13) 
             
             
               9 
               Incident beam 
             
             
               10 
               Reflected beam 
             
             
               11 
               Force vector (bringing into working position) 
             
             
               12 
               Force vector (bringing out of working position) 
             
             
               13 
               Beam passing through 
             
             
               14 
               Tilt axis 
             
             
               15 
               Recess in (1a) for precise execution of tilting motion of (1a) 
             
             
               E1 
               Common plane of (2) and (4), (4c′, 4d′) 
             
             
               E2 
               Common plane of (6a), (6b), and (6c)