Abstract:
A sight for firearms based on a non-collimating optical system includes a reticle, a lens and a housing for holding the reticle to be centered with the optical axis of the lens, which is parallel to the barrel&#39;s center line of the firearm. The reticle is located axially apart of the lens back focal plane and projected toward the user&#39;s eye, such that the projected reticle appears centered to the lens barrel only when the user eye is on the same lens optical axis.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention is related to a non-collimated beam sight for use with short firearms, long firearms and other projectile launching devices. The invention is also related to a device that permits particularly quick and accurate adjustment of a sight of the fire arm, so as to allow excellent alignment of the sight with the aiming lime to the target. 
       BACKGROUND OF THE INVENTION 
       [0002]    Sighting devices have been known for long time, most of which include a reticle or aiming point, the image of which is collimated with a collimating lens or a concave mirror and projected toward the eye of the viewer along parallel paths. Such collimating sights are advantageous for short range shooting where no magnification is needed, because the image of the reticle is projected out to an infinite point in space and is therefore always on target. Such sights also eliminate parallax with the result that the reticle image stays on the target even if the viewer moves his head. The main disadvantage of such configurations is a very small field of view, left for the shooter to detect the aiming point. It is even worth in case of a hand held pistol, where the hand movement make a very large bowing angle with respect to the shooter line of sight. 
         [0003]    The collimating sights of the prior art are of two general types, both of which are designed for use with a generally short eye relief, and therefore, are usually mounted on the receiver portion of a rifle or a shotgun in close proximity to the eye of the shooter. The first general type of collimator sight of the prior art is disclosed in U.S. Pat. No. 1,442,015, issued in 1919 to E. D. Tillyer. This type of sight includes a collimated reticle within a tube about one to two inches in diameter, with the front end of the tube being opaque. As a result, the sight blocks most, or all, of the target from the field of view of the sighting eye of the shooter, and the sight must be used while both eyes of the shooter are open. Thus, the shooter sees the reticle of the sight with one eye and the target with the other eye and must rely on his own binocular ability to superimpose the two images. When a person uses a sight of this type where one eye looks at the reticle and the other eye looks at the field, the phenomenon of exophoria (the deviation of the visual axis of one eye away from that of the other eye in the absence of visual fusional stimuli) tends to frustrate the effort by causing the reticle image to drift over the field image, or to disappear altogether. Exophoria is a latent inability of one eye to attain binocular vision with the other eye because of imbalance of the extrinsic eye muscles, whereby the visual axes tend outward toward the temple. Thus, the first general type of collimated sights are difficult (if not impossible) to use, except for very quick snap shooting. 
         [0004]    However, these sights are collimated and from their nature, when the user rotates his hand with the pistol and the sight on it, in a small angle, the reticule will disappear. The angle from which the shooter can still see the reticle is known to be the Maximum Noticeable Angle (MNA) of the sight. 
         [0005]    Firearms, particularly hand-held fire arms are conventionally aimed by using a sight installed on the firearm and pointing the sight to the target point. By “target” is meant the object or person that the shooter intends to hit, and by “target point” is meant the point of the target at which the shooter aims the projectile. 
         [0006]    Generally the projectiles may hit any point within an area about the target point. When the sight is aligned, it defines an aim line, and when said aim line passes through the shooter&#39;s aiming eye, the axis of the fire arm barrel should be substantially directed to the target point. 
         [0007]    The accuracy of hand-held guns greatly depends on the relative orientation between the aiming line of the shooter&#39;s eye and the central axis of the gun&#39;s barrel. Since the aiming line coincides with the shooter&#39;s eye and with the target, in order to hit the target accurately, the aiming line and the central axis of the gun&#39;s barrel must be parallel. Otherwise, the bullet may deflect from the target&#39;s center. 
         [0008]    Since any sight is mounted on top of the gun&#39;s slide, in most cases it is not perfectly aligned due to manufacturing and assembly tolerances. Therefore, it should contain an alignment mechanism, which can adjust its orientation with respect to the slide. Generally, the existing mechanisms are complex and expensive due to several alignment mechanical parts needed. Another problem arises when the shooter views the optical indication that is displayed when the sight is aligned. In many cases, the optical indication is an image of an optical fiber, which collects and transmits light to its proximal end (closer to the shooter&#39;s eye) and displays an illuminated dot. However, sometimes this dot is not sufficiently large and therefore, it is more difficult to the shooter to have a clear indication when exactly to shoot. 
         [0009]    It is therefore, an object of this invention to provide a non-collimating sight for use with a firearm, or the like, which can be used by a shooter with either one eye or both eyes open. 
         [0010]    It is a further object of this invention to provide a sight which is sufficiently small, so as not to obscure the target when the sight is used with only one eye of the shooter open thus making it possible to shoot with one eye or two. 
         [0011]    It is still another object of this invention to provide a much shorter sight compare to the same reticle size, as in the prior art. 
         [0012]    It is yet another object of this invention to provide a sight of the character described which is durable, inexpensive to manufacture, of simple construction, and yet reliable for short range shooting. 
         [0013]    It is therefore needed to provide a simpler and more efficient mechanism, which includes only few moving parts. This is an additional object of the present invention—to provide such mechanism that is simple and that can be easily adjusted to obtain the desired alignment. 
         [0014]    A further object is to provide a sight with a simple and reliable mechanism that allows a shooter to adjust the size of the image displayed by the optical fiber. 
         [0015]    Other purposes and advantages of the invention will appear as the description proceeds. 
       SUMMARY OF THE INVENTION 
       [0016]    The non-collimating sight of this invention is adapted so as to be usable by a shooter with either one eye or both eyes open, and is preferred to be used at a distance of from about 3 to about 4 feet from the eye of the shooter. The sight is sufficiently small as its footprint size over the target, so as not to obscure the target even when only one eye is used by the shooter to sight in on the target. Thus, the sight of this invention has the advantages of having a large MNA while keeping high accuracy for bore sighting. 
         [0017]    To understand the nature of this invention, the meaning of the Maximum Noticeable Angle—MNA will be explained first. In general, the MNA is the maximum angle around a line of sight within which the shooter can see the reticule. The MNA is based on two angles. The first one is the angle which the shooter sees the angle with one eye without moving his head or hand—Instantaneous Field Of View—IFOV and the other angle is that related to the structure of the sight itself—Total Field Of View—TFOV. In more details, this angle—the TFOV depends on the reticle size and location in respect to the lens, the lens diameter, and the system magnification. The sum of the IFOV and the TFOV is the MNA. 
         [0018]    The present invention is directed to a sight for firearms based on a non-collimating optical system, which comprises: 
         [0019]    a) a reticle; 
         [0020]    b) a lens; and 
         [0021]    c) a housing for holding the reticle to be centered with the optical axis of the lens, which is parallel to the barrel&#39;s center line of the firearm, wherein the reticle is located axially apart of the lens back focal plane and being projected toward the user&#39;s eye, such that the projected reticle appears centered to the lens barrel only when the user eye is on the same lens optical axis. 
         [0022]    The distance of the reticle along the lens optical axis may be longer or smaller than the back focal length of the lens. 
         [0023]    The reticle may be a light emitting diode or the end of a florescent optical fiber. 
         [0024]    The lens may be a thick lens having a thickness which is larger or smaller than the side lens back focal length. 
         [0025]    The sight may comprise: 
         [0026]    a) a lens with thickness of grater or smaller than its back focal length, the lens having at least one outer surface with optical power; 
         [0027]    b) a florescentic optical fiber attached to the distal surface of the lens, the proximal end of which is being projected by the lens, to form an image to be seen by the shooter, and located at the opposite side of the outer surface of the lens; and 
         [0028]    c) a housing for holding the florescentic fiber to coincide with the optical axis of the lens, which is parallel to the central axis of the barrel of the firearm, wherein the florescentic fiber is located axially apart of the lens back focal plain and being projected toward the user&#39;s eye, such that the projected florescentic fiber appears centered with the lens only when the user&#39;s eye is aligned with the same lens optical axis. 
         [0029]    The lens may be a thick solid lens made of injection molded plastic material and may include a bore in its distal side opposite to the shooter. The bore has a diameter which is being adapted to receive the optical florescent fiber. 
         [0030]    The optical florescent fiber may be embedded into the injection molded lens, to thereby form a single part. The injection molded lens may include a mounting projection, to be attached to the firearm and an opaque layer for covering a portion of the exterior surfaces of the injection molded lens. 
         [0031]    The present invention is also directed to an optical aiming device for presenting a clear and distinctive image to a shooter with a controlled size and compensation capability, which comprises: 
         [0032]    a) a housing that is mounted to the slide of the firearm; 
         [0033]    b) a rotatable lid (which may be cylindrical) terminating the distal end of the housing, the rotatable lid having an external part with a similar diameter as the tubular housing that gathers light and an internal cylindrical part that is inserted into the distal end of the tubular housing, wherein the internal cylindrical part has smooth external face that is adjacent to the internal face of the tubular housing and both faces have a matching circumferential groove, into which a mating ring is inserted, so as to keep the rotatable lid attached to the tubular housing, and the internal cylindrical part has threaded internal face to receive a mating screw; 
         [0034]    c) a mating screw, which has a bore with diameter similar to the diameter of an optical fiber along its central axis, the mating screw is screwed into the threaded face, while its head has a projection that enters a mating groove along the internal face of the tubular housing; 
         [0035]    d) an optical fiber that is inserted into the bore and fixed to the screw, such that its distal end extends outwardly into the cavity formed by the internal face of the rotatable, so as to gather light; 
         [0036]    e) a sphere with a bore slightly larger than the diameter of the optical fiber, such that the bore coincides with the central axis of the tubular housing and the opposing end of the optical fiber penetrates the bore, is free to move along the bore, and extends outwardly from the sphere, while coinciding all the time with the central axis of the tubular housing, wherein the sphere has a groove that mates a corresponding opening in the wall of the tubular housing, for receiving a mating lever for rotating the sphere in any desired direction; 
         [0037]    f) a lens at the proximal end of the tubular housing for receiving an image of the optical fiber and for projecting the image to a point which is closer to the shooter&#39;s eye and coincides with the aiming line, to form an illuminated dot with a controllable diameter, depending on the length of the optical fiber that extends out of the sphere towards the shooter&#39;s eye, 
         [0038]    wherein when the rotatable lid rotates, the screw moves linearly along the aiming line, while the proximal end of the optical fiber extends more or less outwardly from the sphere. 
         [0039]    Whenever the sphere is rotated vertically, the fiber is twisted such that its proximal end deflects from the central axis of the tubular housing in a direction that compensates for misalignment of the aiming device as desired. 
         [0040]    The tubular housing may be mounted to the slide of the firearm by a dovetail joint. The groove may be in the form of a semi-circle, into which a mating O-ring is inserted. 
         [0041]    These and other objects and advantages of the sighting device of this invention will become more readily apparent from the following detailed disclosure of several preferred embodiments thereof along with the accompanying drawings 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0042]    In the drawings: 
           [0043]      FIGS. 1A and 1B  show a visual illustration of the term Maximum Noticeable Angle (MNA); 
           [0044]      FIG. 2  is a schematic drawing of a prior art collimated sight; 
           [0045]      FIG. 3  describes a schematic explanation for the MNA of a preferred embodiment; 
           [0046]      FIG. 4  is a cross sectional view of a preferred embodiment of a non-collimating sight; 
           [0047]      FIGS. 5A  and B show the whole scenario of a preferred embodiment in bore-sight position, and the silhouette of what the shooter will see; 
           [0048]      FIGS. 6A and 6B  show the whole scenario of a preferred embodiment out of bore-sight position, and the silhouette of what the shooter will see; 
           [0049]      FIG. 7  is a cross sectional view of a second preferred embodiment; 
           [0050]      FIGS. 8A and 8B  show the whole scenario of the second preferred embodiment in bore-sight position, and the silhouette of what the shooter will see; 
           [0051]      FIGS. 9A and 9B  show the whole scenario of the second preferred embodiment out of bore-sight position and the silhouette of what the shooter will see; 
           [0052]      FIG. 10  describes another embodiment of the invention; 
           [0053]      FIGS. 11-13  describe other embodiments that allow reducing the manufacturing cost of the sight; 
           [0054]      FIG. 14  illustrates a cross-sectional view of the proposed aiming device which includes an arrangement that is installed on the slide of a gun and allows presenting a clear and distinctive image to the shooter, at a controlled size that is optimal for him; and 
           [0055]      FIGS. 15-19  illustrate several cross-sectional views of the proposed aiming device shown in  FIG. 14 . 
       
    
    
     DESCRIPTION OF EMBODIMENTS 
       [0056]    In  FIGS. 1A and 1B  one can see the meaning of the Maximum Noticeable Angle—MNA.  FIG. 1A  shows a shooter using a small MNA sight and  FIG. 1B  shows the shooter using a large MNA sight. Its easy to understand that in case the shooter have a larger MNA, its easier for him to see the reticule and rapidly aim to the target, while when the MNA is small, it will take him more time just to find the reticule in the reign of interest field of view, and just then to aim his weapon toward the target. 
         [0057]      FIG. 2  is a schematic drawing of a prior art collimated sight describing the small MNA. The reticle  1  is placed at the focal plane of lens  2 , and thus the chief ray  333  and the marginal ray  444  have the same angle with respect to the optical axis  555  after being refracted by the lens  2 . The magnification of the lens is very high so that the rays coming out of the sight have a small TFOV  3 . Normally, the TFOV is the Arc-Tangent of the ratio between the reticle size/Lens focal length. In most of the optical sights, the TFOV is about 1 deg or even smaller. The IFOV  5  is the angle of a cone with its base laying on the lens diameter  2  and its heights equivalent to the distance between the shooters eye  4  and the lens  2 . In this case, the MNA is given by: 
         [0000]      MNA=TFOV+IFOV 
         [0058]    In most of the collimating sights, the TFOV is smaller than the IFOV, otherwise, the projected reticle will be larger than the lens diameter and that will cause losses of accuracy of bore-sighting. Since the MNA is small, it will make the shooter more time to find the projected sight on the target. 
         [0059]      FIG. 3  describes a schematic explanation for the MNA of a preferred embodiment. A lens  6  relays the reticule  7  toward the shooter&#39;s eye  8  at the image plane  9 . A marginal ray  10  exits the upper side of the reticle and is refracted by the lens  6  as ray  11 . The same applies for ray  12  which is refracted by the lens  6  as ray  13 . The angle between ray  11  and  13  is the TFOV  14 . If the size of the reticle  7  is much smaller with respect to the focal length of lens  6 , it can be assumed that angle  14  is given by: 
         [0000]      Angle 14=2×Arcsin(NA Image )
 
         [0060]    NA Image  is the Sine of the half angle of the cone of light at the image space. 
         [0061]    The NA in the image space is the NA in the object space multiplied by the magnification M. 
         [0000]      NA Image =M×NA Object  
 
         [0062]    So that the TFOV is given by: 
         [0000]      TFOV=M×2Arcsin(NA Object )
 
         [0063]    And the MNA is: 
         [0000]      MNA=×2Arcsin(NA Object )+IFOV
 
         [0064]    Since the magnification of this embodiment is much smaller than the one in the collimating sight, it defiantly enlarges the TFOV of the sight. The IFOV  15  stays the same as for the collimated sight that makes the MNA of this embodiment much larger than the one describes in the prior art. 
         [0065]      FIG. 4  shows a cross section of the preferred embodiment of a non-collimating sight. The sight body  20  is attached by a dove-tail  21  to the slide of gun  22 . The sight body  20  comprises a lens  23 , the optical axis  152  of which is parallel to the gun&#39;s barrel  150  “center line”  151 , and a reticle  24 , which is centered to coincide with the lens optical axis  152 . The lens  23  projects a real magnified image of the reticle  24 , to the image plane  26  located between the lens  23  and the shooter&#39;s eye  27 . In this case, the reticle  24  is the end of a florescent fiber  25 . The TFOV  28  of this configuration is the angle between the two marginal rays  29  and  30 . Since the magnification is much smaller than in the one of the prior art, its mean that the MNA is much larger. 
         [0066]      FIG. 5A  shows the whole scenario of the preferred embodiment of shooter&#39;s eye  40 , the gun  41 , the sight  42  and the target  43 , so that the line of sight  44  to the target and the gun&#39;s line of sight  45  are parallel. 
         [0067]      FIG. 5B  shows the silhouette of what the shooter will see when the line of sight will be aligned with the bore sight. He will be able to see the target  50 , which is placed far from him, the silhouette of the gun and the sight  51  and a projected reticle  52  located between the sight and the shooter&#39;s eye and being centered to the sight lens. 
         [0068]      FIG. 6A  show the whole scenario of the gun  61  and the sight  62  when they are not in bore sight with the shooter&#39;s eye  60  and the target. In this case, the line of sight  65  to the target  63  is not parallel to the gun line of sight  64 , so the projected reticle  66  will not be centered on the target  63 . 
         [0069]      FIG. 6B  shows the silhouette of what the shooter will see when the gun and the sight will not be in bore sight with the target. In this case, the target  70  is placed far from him, the silhouette of the gun and the sight  71  and the projected reticle  72  located between the sight and the shooter&#39;s eye and not being centered to the sight. 
         [0070]      FIG. 7  shows a cross section of the second preferred embodiment of a non-collimating sight. The sight body  80  is attached by a dove-tail  81  to the gun  82 . The sight body  80  comprises a lens  83 , which its optical axis  162  is parallel to the gun&#39;s barrel  161  “center line”  152 , and a reticle  84  is centered to the “lens optical axis”  162 . The lens  83  projects a virtual and magnified image of the reticle  84 , to an image plane  86  located at the same side of the reticle  84  side. In this case, the reticle  24  is the end of a florescent fiber  85 . The TFOV  87  of this configuration is the angle between the two marginal rays  89  and  90 . Since the magnification is much smaller than in the one of the prior art, its mean that the MNA is much larger. 
         [0071]      FIG. 8A  show the whole scenario of the second preferred embodiment of a shooter&#39;s eye  97 , the gun  91 , the sight  92  and the target  93 , are all bore-sighted on line so that the “target line of sight”  94  and the “gun line of sight”  95  are parallel. 
         [0072]    In  FIG. 8B  one can see the silhouette of the scenario as described in  FIG. 8A . The shooter will see the silhouette of the gun and the sight  99  on the target  98  background while the projected reticle  100  will be centered to the sight&#39;s silhouette. 
         [0073]      FIG. 9A  shows the whole scenario of the second preferred embodiment of a shooter&#39;s eye  109 , the gun  101 , the sight  102  and the target  103 , are all not in bore-sighted so that the “target line of sight”  104  and the “gun line of sight”  105  are not being parallel. 
         [0074]    In  FIG. 9B  one can see the silhouette of the scenario as described in  FIG. 9A . The shooter will see the silhouette of the gun and the sight  106  on the target  107  background, while the projected reticle  108  will not be centered to the sight&#39;s silhouette. 
         [0075]      FIG. 10  describes another embodiment of the invention. In this figure one can see a the sight housing  111 , containing a transparent cover  113 , a thick lens  110  made of injection molded plastic material, a florescent optic fiber  112 , where its proximal end  115  is being projected by the lens  110 , to form an image  114  to be seen by the shooter. 
         [0076]      FIG. 11  describes another embodiment that allows reducing the manufacturing cost of the sight. The sight is built of only 3 parts, the body  120 , the injection molded lens  121  so that at the opposite side to the shooter, there is a bore  122  in such a diameter to allow inserting the florescent fiber optic  113 . 
         [0077]      FIG. 12  describes another embodiment of the invention that allows reducing the manufacturing cost of the sight even more as describe in  FIG. 11 . In this embodiment, the sight can be build by only two parts, the body  133 , and the lens  130 . The lens  130  and the florescent fiber optic  131  are made as one part, using an injection molding technology. 
         [0078]      FIG. 13  describes another embodiment of the invention that allows reducing the manufacturing cost of the sight even more. In this embodiment, the sight can be build by only single transparent injection plastic element  140 , which contains the lens front surface  141 , the florescent fiber  141  a “dove tail” 143  to connect the sight to the weapon. Since the material of the whole sight is transparent, some of the exterior surfaces  144  must be opaque, except for the front lens surface  141  and at least one zone  145  close to the florescent fiber  142 , which should remain transparent. 
         [0079]      FIG. 14  illustrates a cross-sectional view of the proposed aiming device which includes an arrangement that is installed on the slide of a gun and allows presenting a clear and distinctive image to the shooter, at a controlled size that is optimal for him. The aiming device includes a tubular housing  4  that is mounted to the slide of the firearm by a “dovetail” joint  7 . The distal end of the tubular housing  4  is terminated by a cylindrical rotatable lid  1  with an external cylindrical part (in a similar diameter as the tubular housing  4 ) that gathers light and an internal cylindrical part that is inserted into the distal end of the tubular housing  4 . The internal cylindrical part has smooth external face that is adjacent to the internal face of the tubular housing  4 . In addition, both faces have a matching circumferential groove in the form of a semi-circle, into which a mating O-ring is inserted, so as to keep the rotatable lid  1  attached to the tubular housing  4 . The internal cylindrical part has threaded internal face to receive a mating screw  2 . 
         [0080]    The mating screw  2 , which has a bore with diameter similar to the diameter of an optical fiber  3  along its central axis, is screwed into the threaded face while its head has a projection that enters a mating groove along the internal face of tubular housing  4 . This projection prevents screw  2  from rotating. As a result, while rotatable lid  1  rotates, screw  2  moves linearly back and forth within tubular housing  4 , depending on the rotation direction. Optical fiber  3  is inserted into the bore and fixed to screw  2  (e.g., by gluing it) such that its distal end extends outwardly into the cavity formed by the internal face of rotatable lid  1 , so as to gather light. The opposing end of optical fiber  3  penetrates a sphere  5  with a bore slightly larger than its diameter, such that this bore coincides with the central axis of the tubular housing  4  and optical fiber  3  is free to move along this bore. The proximal end of optical fiber  3  extends outwardly from the sphere, while coinciding all the time with the central axis of tubular housing  4 . Sphere  5  has a rectangular groove  10  that mates a corresponding opening in the wall of the tubular housing  4 , so as to receive a mating lever for slightly rotating the sphere in any desired direction. 
         [0081]    The optical concept is to include a lens  8  at the proximal end of tubular housing  4  that receives an image of an input object (in this example, optical fiber  3 ) at a point  6 , which may be located at a distance from the lens  8 , which may be longer or shorter that the focal length of the lens. This way, the image of the input object is projected to point  9 , which is closer to the shooter&#39;s eye and coincides with the aiming line. In this situation, the gathered light will be projected by the optical fiber as an illuminated dot with a controllable diameter, depending on the length of the optical fiber that extends out of sphere  5  towards the shooter&#39;s eye. 
         [0082]      FIG. 15  illustrates a cross-sectional view of the proposed aiming device shown in  FIG. 14  above, after the shooter rotates the rotatable lid  1  in a direction that causes screw  3  to move linearly towards the shooter&#39;s eye. As a result, the proximal end of optical fiber  3  extends more outwardly from the sphere, while coinciding all the time with the central axis of tubular housing  4 . The image (dot) is now projected by lens  8  to a point  9 , which closer to the shooter&#39;s eye and therefore, the shooter sees a magnified dot. If the shooter wishes to see less magnified dot, he should rotate the rotatable lid  1  in the opposite direction, so as to allow the proximal tip of optical fiber  3  to move towards the target and extends from sphere  5  less than before. 
         [0083]      FIG. 16  illustrates a cross-sectional side view of the proposed aiming device shown in  FIG. 14  above, after the shooter rotates the sphere  5  vertically in a counterclockwise direction. As a result, the fiber  3  is slightly twisted, such that its proximal end deflects downwardly from the central axis of tubular housing  4 . This deflection compensates for misalignment of the aiming device upwardly as desired, without needing any mechanical adjustment of the mounting mechanism of the aiming device. 
         [0084]      FIG. 17  illustrates a cross-sectional side view of the proposed aiming device shown in  FIG. 14  above, after the shooter rotates the sphere  5  vertically in a clockwise direction. As a result, the fiber  3  is slightly twisted, such that its proximal end deflects upwardly from the central axis of tubular housing  4 . This deflection compensates for misalignment of the aiming device downwardly as desired, without needing any mechanical adjustment of the mounting mechanism of the aiming device. 
         [0085]      FIG. 18  illustrates a cross-sectional top view of the proposed aiming device shown in  FIG. 14  above, when the aiming device and sphere  5  are horizontally aligned with the aiming line to the target. In this case, the lever position keeps fiber  3  linear, while it&#39;s proximal end is aligned with the central axis of tubular housing  4 , such that the image of the proximal tip of optical fiber  3  is projected by lens  8  on the aiming line without deflection. If compensation is needed, the shooter can rotate the lever in the appropriate direction. 
         [0086]      FIG. 19  illustrates a cross-sectional top view of the proposed aiming device shown in  FIG. 14  above, after the shooter rotates the sphere  5  horizontally in a clockwise direction. As a result, the fiber  3  is slightly twisted, such that its proximal end deflects laterally (to the left) from the central axis of tubular housing  4 . This deflection compensates for misalignment of the aiming device laterally (to the right) as desired, without needing any mechanical adjustment of the mounting mechanism of the aiming device. 
         [0087]    The above examples and description have of course been provided only for the purpose of illustration, and are not intended to limit the invention in any way. As will be appreciated by the skilled person, the invention can be carried out in a great variety of ways, employing more than one technique from those described above, all without exceeding the scope of the invention.