Abstract:
A telescope has at least one barrel. At least three optical elements, namely an objective lens, an inverting system, and an eyepiece are arranged within the barrel along a longitudinal axis thereof one behind another. Further, means are provided for compensating shaking movements of the barrel by moving at least one of the optical elements relative to the barrel. The objective lens is rigidly connected to the barrel. The inverting system together with the eyepiece constitutes a common assembly. At least a part of the assembly is adapted to be moved relative to the longitudinal axis. As an alternative, the inverting system and the eyepiece are rigidly connected to the barrel and at least a part of the objective lens is adapted to be moved relative to the longitudinal axis.

Description:
FIELD OF THE INVENTION  
       [0001]     The invention, generally, is related to the field of telescopes.  
         [0002]     More specifically, the invention is related to the field of monocular or binocular telescopes having means for compensating shaking movements in order to avoid blurred images.  
         [0003]     Still more specifically, the invention is related to a telescope having at least one barrel, wherein at least three optical elements, namely an objective lens, an inverting system, and an eyepiece are arranged within the barrel along a longitudinal axis thereof one behind another, and comprising means for compensating shaking movements of the barrel by moving at least one of the optical elements relative to the barrel.  
       BACKGROUND OF THE INVENTION  
       [0004]     When a target object is viewed no-handed with a monocular or a binocular telescope, i.e. without a support or stand or the like, there is always the risk of shaking movements blurring the image. The cause for such shaking movements may be in the user, for example due to jitter movements of the hand or due to a general motional unrest after a strenuous physical activity, e.g. during a mountain tour. On the other hand, external influences might likewise result in shaking movements, for example a waving or vibrating base of a terrestrial, nautical, or aerial vehicle, or the force of strong wind.  
         [0005]     All this has the effect that in spite of highly developed optical imaging systems the theoretical resolution and discernability of details on the object under observation may in practice not be fully taken advantage of when there are such factors of trouble.  
         [0006]     It has turned out that from the six possible movements of a telescope, namely the three linear movements along axes of a Cartesian coordinate system as well as the three rotational movements about these axes, essentially only the rotational movements about the two axes orthogonal to the optical axis (direction of vision), i.e. the rotational movements about the vertical axis and about the transverse axis are responsible.  
         [0007]     In order to avoid the problems discussed above, various suggestions have become known. Some known suggestions are based on a concept according to which optical elements are movably supported within the ray path of the telescope, and are stabilized by means of inertial devices, for example by gyros.  
         [0008]     These prior art suggestions have the disadvantage that relative large masses must be provided and moved, respectively. Such telescopes, therefore, are relatively heavy and must be manufactured with high precision.  
         [0009]     For binoculars one has the additional problem that the stabilizing measures in the two barrels must be coordinated.  
         [0010]     More recent suggestions utilize an active stabilization instead of the above discussed purely mechanic and passive stabilization. When doing so, sensors measure the shaking movement of the barrel or barrels, respectively. An electronic position control compensates the barrel movement by means of actuators generating an oppositely directed movement of optical elements within the ray path of the telescope.  
         [0011]     U.S. Pat. No. 4,235,506 discloses a binocular telescope. In this prior art telescope there is an inverting system, namely a prism, arranged within each of the barrels. The two prisms are gimballed.  
         [0012]     This telescope has the disadvantage that a compensation of shaking movements is not always possible in an optimal way.  
         [0013]     German disclosure document DE 15 47 129 A discloses a periscope in a vehicle having means for displacing a prism to compensate vehicle movements. The prism is a unit separate from the eyepiece.  
         [0014]     U.S. Pat. No. 6,078,436 discloses a device for compensating jitter movements in a binocular telescope. The device comprises a movable plate having two lenses. In each of the barrels the inverting system and the eyepiece configure a common assembly, however, for adjusting the pupillary distance only.  
         [0015]     A similar device is disclosed in U.S. Pat. No. 5,917,653.  
         [0016]     U.S. Pat. No. 6,191,888 discloses a binocular telescope with a device for compensating shaking movements in which both the eyepiece and the inverting system are rigidly connected to the barrel, whereas the objective lens is displaceable for compensating such movements.  
         [0017]     Another binocular with an image-vibration compensation system is disclosed in U.S. Pat. No. 6,226,123.  
       SUMMARY OF THE INVENTION  
       [0018]     It is, therefore, an object underlying the invention to provide a telescope of the type specified at the outset which overcomes the above-mentioned disadvantages. In particular, a telescope shall be provided which enables an effective compensation of shaking movements.  
         [0019]     In a first embodiment of a telescope of the type specified at the outset, this object is achieved in that the objective lens is, preferably, rigidly connected to the barrel, that the inverting system together with the eyepiece constitutes a common assembly, and that at least a part of the assembly is adapted to be moved relative to the longitudinal axis.  
         [0020]     In a second embodiment of a telescope of the type specified at the outset, this object is achieved in that the inverting system and the eyepiece are, preferably, rigidly connected to the barrel, and that at least a part of the objective lens is adapted to be moved relative to the longitudinal axis.  
         [0021]     The object underlying the invention is, thus, entirely solved.  
         [0022]     The afore-mentioned arrangements of optical elements being movable for compensating purposes have turned out to be particularly effective. They are relatively simple to manufacture and have a low weight.  
         [0023]     In preferred embodiments of the invention, the assembly or the objective lens, respectively, are gimballed about a transverse axis and about a vertical axis, in particular in a pivotal point being located on the longitudinal axis which, further preferably, being located in the center point of the objective lens or in the area of the objective lens, respectively, in particular on the side of the eyepiece facing away from the inverting system.  
         [0024]     Within the scope of the present invention one may use passive as well as active systems. The movement of the at least one optical element may, therefore, be effected passively by inertial forces, or actively by actuators.  
         [0025]     Further advantages will become apparent from the description and the enclosed drawing.  
         [0026]     It goes without saying that the features mentioned before and those that will be discussed hereinafter may not only be used in the particularly given combination but also in other combinations, or alone, without leaving the scope of the present invention.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0027]     Embodiments of the invention are shown in the drawing and will be discussed in further detail throughout the subsequent description.  
         [0028]      FIG. 1  shows an extremely schematic and perspective representation of a telescope as may be used in the context of the present invention;  
         [0029]      FIG. 2  shows a side elevational view of a first embodiment of the optical elements of the telescope of  FIG. 1  being of importance in the context of the present invention, in a non-disturbed state;  
         [0030]      FIG. 3  shows the view of  FIG. 2 , however, in a state disturbed by shaking movements;  
         [0031]      FIG. 4  shows a side elevational view of a second embodiment of the optical elements of the telescope of  FIG. 1  being of importance in the context of the present invention, in a non-disturbed state;  
         [0032]      FIG. 5  shows the view of  FIG. 4 , however, in a state disturbed by shaking movements;  
         [0033]      FIG. 6  shows a side elevational view of a third embodiment of the optical elements of the telescope of  FIG. 1  being of importance in the context of the present invention, in a non-disturbed state; and  
         [0034]      FIG. 7  shows the view of  FIG. 6 , however, in a state disturbed by shaking movements. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0035]     In  FIG. 1  reference numeral  10  as a whole designates a telescope. Telescope  10  may be a monocular telescope, as indicated with solid lines, or it may be a binocular telescope, as indicated additionally by dashed lines. The following description of embodiments of the invention is based on a monocular telescope, however, without thereby limiting the scope of the invention.  
         [0036]     Telescope  10  has a barrel indicated at  11 . Barrel  11  has a longitudinal axis  12 , also designated as z-axis.  
         [0037]      FIG. 1  shows an undisturbed state of telescope  10  in which there is no shaking movement. In that state an optical axis  13  coincides with longitudinal axis  12 . At least three optical elements are arranged along axes  12 ,  13  one after another, namely, as seen from the object side, an objective lens  14 , an inverting system  16 , and an eyepiece  18 . In all embodiments shown, inverting system  16  is, as an example, configured as a Pechan prism arrangement. In further embodiments of the invention one may still provide a fourth optical element, namely one more prism (not shown), between inverting system  16  and eyepiece  18 , for allowing a variation of the eyepiece distance.  
         [0038]     Besides the already mentioned longitudinal or z-axis  12 ,  FIG. 1  further shows a transverse or x-axis  20  as well as a vertical or y-axis  22 . With regard to these axes, telescope  10  may effect linear movements along these three Cartesian coordinate axis directions. Further, there are three rotational movements about said axes  12 ,  20 , and  22 , as indicated by arrows  24 ,  26 , and  28 . In practice it are essentially the rotational movements about x-axis  20  and y-axis  22 , indicated by arrows  26  and  28  which are noticeable with regard to malfunctions caused by shaking movements.  
         [0039]      FIGS. 2 and 3  show a first embodiment of the invention.  
         [0040]     A telescope  30  has a barrel as schematically indicated at  31 . Barrel  31  has a longitudinal axis shown at  32 . An optical axis is designated  33 . An objective lens  34  is again positioned within barrel  31 . Objective lens  34  is rigidly connected to barrel  31  by means of a connecting element  35 , being, for example, and appropriate mount. Behind objective lens  34  there is positioned an inverting system  36  and, again, an eyepiece  38 .  
         [0041]     Inverting system  36  and eyepiece  38  together configure an assembly  40 , i.e. they are rigidly connected one with the other and are movable together. In this embodiment, assembly  40  with inverting system  36  and eyepiece  38  define the optical axis  33 .  
         [0042]     Assembly  40  is seated in a pivotal point  42  by means of a lever (not shown). Pivotal point  42  is located on longitudinal axis  32 , namely in the center point of objective lens  34 . The seating within pivotal point  42  is gimballed and allows a rotation of assembly  40  both about x-axis  20  and about y-axis  22 . Assembly  40 , however, may also be gimballed only partially, for example with respect to all components of inverting system  36  and of eyepiece  38 , except the last individual lens.  
         [0043]      FIG. 2  shows the undisturbed sate in which optical axis  33  coincides with longitudinal axis  32  of barrel  31 .  FIG. 3 , in contrast, shows the disturbed stat in which a shaking movement has caused a rotation of barrel  31  about x-axis  20 . An angle of rotation is indicated at  44  and may, for example, amount to about 2°. In  FIG. 3 , as well as in  FIGS. 5 and 7 , the disturbed state is symbolized by the addition of an apostrophe to the reference numerals of the components involved.  
         [0044]     Due to the rotation, telescope  30  with its barrel  31  makes a downward tipping movement at its front end about angle  44 , as indicated by an arrow  46 . Thereby, longitudinal axis  32  is pivoted to  32 ′. Assembly  40  with inverting system  36  and eyepiece  38 , however, being gimballed within pivotal point  42 , maintains its orientation, and, thereby, compensates the shaking movement.  
         [0045]     According to a first alternative of this embodiment this is achieved passively by resiliently seating corresponding inertial masses, such that assembly  40  maintains its orientation already due to this mass inertia.  
         [0046]     According to a second alternative, however, the shaking movement is measured by appropriate sensors (not shown) and processed. By means of actuators, one of which being indicated at  48  in  FIGS. 2 and 3 , a movement compensation is effected for assembly  40 , as indicated by an arrow  49 .  
         [0047]     The active and the passive approaches may also be combined as appropriate.  
         [0048]      FIGS. 4 and 5  show a second embodiment of the invention.  
         [0049]     A telescope  50  has a barrel as schematically indicated at  51 . Barrel  51  has a longitudinal axis shown at  52 . An optical axis is designated  53 . An objective lens  54  is again positioned within barrel  51 . Behind objective lens  54  there is an inverting system  56 , and behind inverting system  56 , there is again an eyepiece  58 .  
         [0050]     In this embodiment, objective lens  54  is not rigidly connected to barrel  51 . However, it does define optical axis  53  for this embodiment. Inverting system  56  and eyepiece  58  again configure a common assembly  60 . Assembly  60  is rigidly connected with barrel  51  via a connecting element  61 .  
         [0051]     Objective lens  54  is seated in a pivotal point  62  by means of a lever (not shown). Pivotal point  62  is located on longitudinal axis  52 , namely in the area of eyepiece  58 , preferably on the side of eyepiece  58  facing away from inverting system  56 . The seating within pivotal point  62  is gimballed and allows a rotation of objective lens  54  about x-axis  20  and y-axis  22 . For this embodiment it holds likewise true that the gimballed element, being objective lens  54  for this embodiment, may be gimballed only partially. If, for example, objective lens  54  consists of two individual lenses, then it may be sufficient to gimbal only one of these two lenses.  
         [0052]      FIG. 4  shows the undisturbed state in which optical axis  53  coincides with longitudinal axis  52  of barrel  51 .  FIG. 5 , in contrast, shows a disturbed state in which a shaking movement has effected a rotation of barrel  51  about x-axis  20 . An angle of rotation is indicated at  64  and may also here amount to about 2°.  
         [0053]     Due to the rotation, telescope  50  with its barrel  51  makes a downward tipping movement at its front end about angle  64 , as indicated by an arrow  66 . Thereby, longitudinal axis  52  is pivoted to  52 ′. Objective lens  54 , however, being gimballed within pivotal point  62 , maintains its orientation, and, thereby, compensates the shaking movement.  
         [0054]     In this embodiment, too, one may compensate passively or actively. The actuators for rotating objective lens  54 , required for the second option, are indicated at  68 ,  69 .  
         [0055]      FIGS. 6 and 7 , finally, show a third embodiment of the invention.  
         [0056]     A telescope  70  has a barrel as schematically indicated at  71 . Barrel  71  has a longitudinal axis shown at  72 . An optical axis is designated  73 . An objective lens  74  is again positioned within barrel  71 . Behind objective lens  74  there is an inverting system  76 , and behind inverting system  76 , there is again an eyepiece  78 .  
         [0057]     In this embodiment, objective lens  74  and eyepiece  78  together configure a common assembly  80 . Assembly  80  is rigidly connected to barrel  71  by means of a connecting element  81 . In this embodiment, assembly  80  defines the optical axis  83 . Inverting system  76  is positioned within a department  82  of assembly  80 .  
         [0058]     Inverting system  76  is slidingly seated within department  82 . The seating allows a displacement of inverting system  76  along x-axis  20  and along y-axis  22 .  
         [0059]      FIG. 6  shows the undisturbed state in which optical axis  73  coincides with longitudinal axis  72  of barrel  71 .  FIG. 7 , in contrast, shows a disturbed state in which a shaking movement has effected a rotation of barrel  71  about x-axis  20 . An angle of rotation is indicated at  84  and may also amount to about 2°.  
         [0060]     Due to the rotation, telescope  70  with its barrel  71  makes a downward tipping movement at its front end about angle  84 , as indicated by an arrow  86 . Thereby, longitudinal axis  72  is pivoted to  72 ′. Inverting system  76  is now displaced along the x- and/or y-directions, and, thereby, compensates the shaking movement.  
         [0061]     In this embodiment, too, one may compensate passively or actively. The actuators for displacing inverting system  76 , required for the second option, are indicated at  88 ,  89 .