Patent Publication Number: US-2022221250-A1

Title: Rifle Scope With Dual Canting Indicators

Description:
TECHNICAL FIELD OF INVENTION 
     The embodiments of the present invention relate to a new mechanism that adds a control dimension to the precision and accuracy of a scoped target. In particular, the present invention is applicable for indicating canting, or axial tilt, of a rifle being aimed at target through a scope. More specifically, the present invention provides a mechanical and a separate electrical control measurement of rifle canting when targeting through a rifle scope, allowing an operator to rely on one or both of the indicators. 
     BACKGROUND OF THE INVENTION 
     Since the early invention of the earliest firearms there has been a never-ending pursuit of more accurate firearms at longer ranges. This necessity is primarily for military use, but also for sport. Clearly, the side with the better firearms that are more accurate, with longer range, and deadly, is at an enormous advantage. Historically, technology generally wins every war. 
     As firearms evolved in their accuracy and range, it became necessary to develop optics that could cite the firearm at ranges further than the human eye could focus. For this purpose, optics were employed in the form of rifle scopes. As firearm and bullet technology continued to evolve, it became necessary to further evolve rifle scopes to compensate for such things as distance (elevation), magnification, wind, and parallax. Eventually, electronic illumination was added for shooting in shadowed or lowlight environments. Digital imaging is also available, but total reliance on a portable power source and operating electronics is a significant disadvantage. 
     While measurements and adjustments have been designed for the cartesian coordinates and built into adjustments within rifle scopes, often neglected is the canting of the rifle itself. This being the possibility that the rifle was slightly rotated about the centerline of its barrel. It has been found that even slight rotation can severely affect the accuracy of longer shots. 
     In response, products are now available that provide a bubble level as an aftermarket product that can be fastened to a scope system. A primary problem with these devices is that they require leveling themselves during installation. If improperly installed or moved and not level, they provide a false indication of the canting of the rifle. A second primary disadvantage of these devices is that they require looking outside of the scope and target to determine if the rifle is canted. On a critical shot, the target can move when the operator takes his eye off the reticle. 
     Digital products are now available that include numerous numerical outputs within the scope, including a digital measure of tilt angle. These designs permit the operator to determine the cant or tilt of the rifle without looking external to an ocular lens—as long as there is electrical power. However, these products suffer the significant disadvantage of requiring the operator to take his or her eye off the reticle-target interface to recognize the representation among other digital outputs, to read it, and then to decide if the displayed number represents an appropriate amount of tilt. A targeted shot at significant distance can easily be lost in this interval, and long-distance shooting is the primary application of the scope&#39;s anti-canting feature. 
     Another disadvantage of these devices is that the numbers are necessarily very small, requiring a heightened level of focus to read them. Another disadvantage of these scopes is that they rely exclusively on electrical power to provide anti-canting functions. The failure of electronics and eventual depletion of the power supply can leave the operator defenseless. 
     As a result, there remains a need for a control parameter for measuring and canting of a scoped rifle that allows the operator to keep his or her full focus of the reticle target interface. There is also a need for a rifle scope system that allows the operator to immediately determine if the rifle is acceptably aligned without looking exterior of the ocular lens. There is also a need for a rifle scope system that allows the operator these benefits in the absence or failure of system electronics. 
     SUMMARY OF THE INVENTION 
     The present invention provides a substantially improved rifle scope. In particular, the present invention provides a rifle scope with dual canting indicators. The first level is a mechanical fluid canting indicator that is readable within the optics of the scope. The second level is an electronic “go” illumination within the optics of the scope. 
     In one embodiment, a rifle scope is provided, comprising an eyepiece assembly on one end of a body tube. An objective bell extends from the opposite end of the body tube extends from the objective bell. A plurality of lenses is positioned within the scope and permit visual acuity and magnification adjustments. 
     In one embodiment, an objective lens is mounted in the objective bell. An ocular lens is mounted within the body tube proximate the eyepiece assembly. A focus lens is mounted between the objective lens and the ocular lens. A reticle is located between the focus lens and the ocular lens. A level is located between the reticle and the ocular lens. A canting turret extends from a first side of the body tube. The canting turret comprises a circuit board connectable to a battery power source. An accelerometer is connected to the circuit board. 
     The circuit board is electrically connected to a reticle LED positioned to illuminate the reticle. The circuit board is electrically connected to a level LED positioned to illuminate the level. An activation switch is electrically connected to the canting turret. 
     In another embodiment, the level is a fluid level having an arc radius in which a bubble in the fluid indicates the true vertical. The fluid may be colored for readability. In one embodiment, the bubble is sized to represent a known angle of arc, such that the amount of tilt of the rifle is measurable against the reticle position as viewed against the bubble. 
     In another embodiment, indicia are located on the level on either side of the bubble (when level) and a known angle of arc, such that the amount of tilt of the rifle is measurable by the bubble&#39;s position relative to the indicia on the level. 
     In another embodiment, the level assembly comprises a level frame. The level and the level LED are mounted to the level frame. In another embodiment, a backing ring is connected to the level frame. 
     In another embodiment, an illumination control switch is located on the exterior of the canting turret, and electrically connected to the circuit board to increase or decrease the illumination of the reticle and/or level LED. 
     In another embodiment, an increase illumination switch and a decrease illumination switch are located on the exterior of the canting turret and are each connected to the circuit board. 
     In another embodiment, a timer is electrically connected to the circuit board, and is initiated by the activation switch. The timer initiates a sleep mode and terminates electrical power to the reticle LED and the level LED at the expiration of a first predetermined amount of time. 
     In another embodiment, a movement sensor for detecting movement of the scope is electrically connected to the circuit board. The movement sensor reactivates the last active mode and levels of illumination to the level LED and the reticle LED after power termination by initiation of the sleep mode by the timer. In one embodiment, the movement sensor is an accelerometer. In another embodiment, the movement sensor function is performed by the same accelerometer that measures inclination of the scope. 
     In another embodiment, a plurality of activation modes is provided. In a first activation mode, power is supplied to the level LED and not to the reticle LED. In a second activation mode, power is supplied to the reticle LED and the level LED. In a third activation mode, power is supplied to the reticle LED and not to the level LED. In a fourth activation mode, power is supplied to the timer and the movement sensor, but not to the reticle LED or the level LED. In a fifth mode, the circuit board is unpowered and deactivated. This is the “power off” mode. 
     In another embodiment, the accelerometer detects the angle of canting of the rifle scope, and the circuit board conditions illumination of the level LED upon the detected angle of canting being less than a predetermined amount. 
     In another embodiment, the level LED is green to indicate the rifle is not excessively canted. In another embodiment, a different colored LED may indicate the rifle is excessively canted. 
     In another embodiment, an erector assembly including magnifying lenses is located between the reticle and the ocular lens. 
     In another embodiment, the battery power source is replaceable or rechargeable through a battery cap located on the canting turret. 
     As will be understood by one of ordinary skill in the art, the assembly disclosed may be modified and the same advantageous result obtained. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an isometric view of an embodiment of the rifle scope  10  of the present invention. 
         FIG. 2  is a left side view of an embodiment of the rifle scope of the embodiment of  FIG. 1 . 
         FIG. 3  is a top view of an embodiment of the rifle scope of the present invention. 
         FIG. 4  is a right side view of an embodiment of the rifle scope of the present invention. 
         FIG. 5  is a top cross-sectional view of an embodiment of the rifle scope of the present invention. 
         FIG. 6  is a side cross-sectional view of an embodiment of the canting turret of the present invention. 
         FIG. 7  is a side cross-sectional view of an embodiment of the level assembly of the present invention. 
         FIG. 8  is an isometric exploded view of the embodiment of the level assembly of  FIG. 7 . 
         FIG. 9  is an isometric view of the embodiment of the level assembly of  FIGS. 7 and 8 . 
         FIG. 10  is a summary operations chart of an embodiment of the circuit board. 
         FIG. 11  is a flow chart representing an embodiment of the modes of operation activated by the operator and the modes of operation automatically activated by the rifle scope. 
         FIG. 12  is a front view of an embodiment of the rifle scope of the present invention. 
         FIG. 13  is a rear view of an embodiment of the rifle scope of  FIG. 12 . 
         FIG. 14  is a rear view of the embodiment disclosed in  FIG. 12  in which the rifle scope is tilted (canted) clockwise. 
         FIG. 15  illustrates the view through the eyepiece when the scope is in a non-powered (or fourth “sleep state”) mode of an embodiment of the invention, in which the level indicates a non-canted inclination. 
         FIG. 16  illustrates the view through the eyepiece when the scope is in a first activation mode, in which the level indicates a non-canted inclination, and in which the level LED is illuminated to further indicate a non-canted inclination. 
         FIG. 17  illustrates the view through the eyepiece when the scope is in a first activation mode, where the level indicates a left canted inclination, and in which the level LED is not illuminated to further indicate an excessively canted inclination. 
         FIG. 18  illustrates the view through the eyepiece when the scope is in a second activation mode of an embodiment of the invention, in which the level indicates a non-canted inclination, and in which the level LED is illuminated to further indicate a non-canted inclination. The reticle is illuminated to assist with low light level shooting. 
         FIG. 19  illustrates the view through the eyepiece when the scope is in a second activation mode of an embodiment of the invention, in which the level indicates a canted inclination, and in which the level LED is not illuminated to further indicate a canted inclination. The reticle is illuminated to assist with low light level shooting. 
         FIG. 20  illustrates the view through the eyepiece when the scope is in a third activation mode of an embodiment of the invention, in which the level indicates a non-canted inclination. The level LED is not powered in this mode. The reticle is illuminated to assist with low light level shooting. 
     
    
    
     The objects and features of the invention will become more readily understood from the following detailed description and appended claims when read in conjunction with the accompanying drawings in which like numerals represent like elements. 
     The drawings constitute a part of this specification and include exemplary embodiments to the invention, which may be embodied in various forms. It is to be understood that in some instances various aspects of the invention may be shown exaggerated or enlarged to facilitate an understanding of the invention. 
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The following description is presented to enable any person skilled in the art to make and use the invention and is provided in the context of a particular application and its requirements. Various modifications to the disclosed embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other embodiments and applications without departing from the spirit and scope of the present invention. Thus, the present invention is not intended to be limited to the embodiments shown but is to be accorded the widest scope consistent with the principles and features disclosed herein. 
       FIG. 1  is an isometric view of an embodiment of rifle scope  10  of the present invention. A canting turret  50  extends from the left side of scope  10 . 
       FIG. 2  is a left side view of the embodiment of rifle scope  10  illustrated in  FIG. 1 . Rifle scope  10  has a body tube  12 . An eyepiece assembly  20  is located on one end of body tube  12 . An objective bell  30  is located at the opposite end of body tube  12 . 
     Eyepiece assembly  20  has a diopter adjustment  22  and a magnification (or power) adjustment  24 . A turret housing  40  is located on body tube  12 . Canting turret  50  is located on the turret housing  40 . 
       FIG. 3  is a top view of the embodiment of rifle scope  10  of  FIG. 1 . As seen in  FIG. 3 , turret housing  40  is located between eyepiece assembly  20  and objective bell  30 . A windage turret  42  extends from the right side of turret housing  40 . An elevation turret  44  extends from the top of turret housing  40 . A parallax turret  46  extends from the left side of turret housing  40 . 
     Unique to the present invention, canting turret  50  extends outward from parallax turret  46 . This has proven extremely convenient for the shooter to access and control. This is significant, as less convenient controls necessarily distract the shooter from maintaining focus on the target. In the embodiment illustrated, canting turret  50  comprises an activation switch  52 , an illumination up switch  54 , and an illumination down switch  56 . A battery cap  58  is secured to the end of canting turret  50  to provide ready access to replace a battery  62  (shown in  FIG. 6 ) which, in place, is electrically connected to a circuit board  60 . 
       FIG. 4  is a right side view of the embodiment of rifle scope  10  shown in  FIGS. 1-3 . 
       FIG. 5  is a top cross-sectional view of the embodiment of  FIGS. 1-3 . As seen in  FIG. 5 , the interior of rifle scope  10  comprises a series of lenses. An ocular lens  70  is located in eyepiece  20 . An objective lens  72  is located in objective bell  30 . A focus lens  74  is located interior to body tube  12 . Magnifying lenses  76  and  78  are located in an erector assembly  75  (not shown) which is subject to lateral repositioning by windage adjustment  42  and to vertical repositioning by elevation adjustment  44 . 
     A reticle  80  is located between ocular lens  70  and objective lens  72 . Reticle  80  has a reticle LED  82  positioned to illuminate reticle  80  when power is transmitted to a second electrical connector  84  which is electrically connected to canting turret  50 . 
     As best seen in  FIG. 3 , activation switch  52  is located on the top of canting turret  50 . Illumination up switch  54  is located on the ocular lens  70  side of canting turret  50 . Illumination down switch  56  is located on the objective lens  72  side of canting turret  50 . 
     Circuit board  60  is located inside canting turret  50 . Battery power source  62  is located inside canting turret  50  and electrically connected to circuit board  60 . Circuit board  60  is electrically connected to activation switch  52 , illumination up switch  54 , and illumination down switch  56 . Circuit board  60  is further electrically connected to reticle LED  82  and to a level LED  92 . 
     A level assembly  90  is located between ocular lens  70  and objective lens  72 . Level assembly  90  has a level LED  92  positioned to illuminate level assembly  90  when power is transmitted to a first electrical connector  94  which is electrically connected to canting turret  50 . 
       FIG. 6  is a cross-sectional top view of the embodiment of canting turret  50  illustrated in  FIG. 5 . Illumination up switch  54  is located on the operator side of canting turret  50 . Illumination down switch  56  is located on the rifle muzzle side of canting turret  50 . 
     Circuit board  60  is located inside canting turret  50 . Battery power source  62  is located inside canting turret  50  and electrically connected to circuit board  60 . Circuit board  60  is further electrically connected to activation switch  52 , illumination up switch  54 , and illumination down switch  56 . As was seen in  FIG. 5 , circuit board  60  is electrically connected to reticle LED  82  and to level LED  92  by electrical connectors  84  and  94 , respectively. Battery cap  58  may secure battery  62  in electrical connection to circuit board  60  by means of a spring or compressible battery pad  64 . 
       FIG. 7  is a side cross-sectional view of an embodiment of level assembly  90  of rifle scope  10 . As seen in  FIG. 7 , level assembly  90  comprises a level frame  96 . A level  98  is mounted in level frame  96  above level LED  92 . As seen in  FIG. 7 , level  98  is positioned directly above level LED  92  such that when power is transmitted through first electrical connector  94 , level LED  92  will illuminate level  98 . 
       FIG. 8  is an isometric exploded view of the embodiment of level assembly  90  of  FIG. 7 . In one embodiment, level  98  is an arced and fluid-filled level that includes a bubble  100 . Level  98  may be filled with a colored fluid to provide contrast to the air or gas of bubble  100 . In one embodiment, the volume, and thus the length of bubble  100 , is precisely controlled to represent a predetermined angle of arc within level  98 . 
     In this embodiment, should the electrical power be lost, the operator can still see the intersection of the lower section of reticle  80  with bubble  100  as seen within ocular lens  70 . As long as they intersect, the rifle is positioned within the predetermined amount of allowable tilt, and the operator need not look external of the scope optics. In another embodiment, reticle  80  intersects bubble  100  only within the same predetermined angular amount of canting required to illuminate level LED  92 . 
     In one embodiment, the length of bubble  100  represents two degrees of angle within level  98 , such that intersection of bubble  100  with reticle  80  will indicate canting within a predetermined allowable angle of one degree. 
     In another embodiment, indicia  102  are inscribed on level  98  on either side of bubble  100  (when level) at a predetermined angle of arc, such that the amount of tilt of scope  10  (and thus the rifle) is measurable by the bubble&#39;s  100  position relative to indicia  102  on level  98 . 
     In one such embodiment, a pair of indicia  102  is inscribed on level  98  and separated by a distance equal to the length of bubble  100  plus two times the predetermined angular amount of allowable canting, such that bubble  100  is located between the pair of indicia  102  when scope  10  is within the same predetermined angular amount of canting required to illuminate level LED  92 . In another embodiment, indicia  102  are located at one degree of angle beyond each end of bubble  100  when oriented level. 
     As seen in  FIG. 8 , level frame  96  has a slot  110  for receiving level  98 . A platform  112  is provided for receiving level LED  92 . In one embodiment, a backing ring  114  secures level  98  inside level frame  96 .  FIG. 9  is an isometric view of the embodiment of level assembly  90  of  FIGS. 7 and 8  shown as assembled. 
       FIG. 10  is a general schematic of an embodiment of circuit board  60 . Circuit board  60  is connected to battery power source  62 . Circuit board  60  is electrically connected to accelerometer  66 , or other movement detecting sensor, and a timer. Circuit board  60  is connected to activation switch  52 , illumination up switch  54  and illumination down switch  56 . 
     Circuit board  60  includes an LED driver  68  which controls the intensity of the LED brightness in response to signals received from illumination up switch  54  and illumination down switch  56 . Circuit board  60  is thereby electrically connected to level LED  92  and reticle LED  82 . 
       FIG. 11  is a flow chart representing an embodiment of modes of operation. In the embodiment illustrated, four modes (Modes  1 ,  2 ,  3  and  0 ) are selectable by the operator by pressing activation switch  52 . Mode  0  being the off, or unpowered mode, in which scope  10  remains functional. 
     In this same embodiment, five modes (Modes  1 ,  2 ,  3 ,  4 , and  0 ) are activated automatically by circuit board  60 . Circuit board  60  selects a mode based on either 1) the expiration of a first predetermined time period, 2) the expiration of a second predetermined time period, or 3) in response to sensor  66  detecting movement of scope  10  prior to the expiration of the second predetermined time period. 
     Referring to the top of the center column of  FIG. 11 , a non-powered mode, designated Mode  0 , is the resting state of scope  10 . All electrical power is conserved and scope  10  is “turned off”. Important to the present invention, in a non-powered mode, scope  10  is functional for shooting and provides an indication of allowable canting that is visible through eyepiece  22 , as seen in  FIG. 15 . This capability prevents the operator from being defenseless or unable to align an accurate long-distance shot in the absence of electrical power. 
     From Mode  0 , the operator activates Mode  1  by pressing activation switch  52  (see  FIG. 11 , input box  1 ). This provides power from battery source  62  to circuit board  60 . In Mode  1 , level LED  92  is activated. As such, when rifle scope  10  is not canted or within the predetermined range of allowable canting, level LED  92  will illuminate level  98 . In one embodiment, the allowable range of canting is 1°. 
     Once activated, the operator may cycle through Mode  1 , Mode  2 , and Mode  3  and back to Mode  1  by momentarily pressing activation switch  52 . This capability is indicated by input boxes  52  that are internally numbered as  1 ,  2 , and  3 . 
     From each of Modes  1 ,  2 , and  3 , the operator can select Mode  0 , which is to turn the power to scope  10  off, by a quick press and release of activation switch  52  (see  FIG. 11 , input boxes  5 ). Circuit board  60  distinguishes the duration of a quick press and release of activation switch  52  from a momentary pressing of activation switch  52 , thus allowing activation switch  52  to perform the two separate functions. 
     To activate Mode  2 , the operator presses activation switch  52  once from Mode  1  (see  FIG. 11 , input box  2 ). In Mode  2 , level LED  92  is powered when accelerometer  66  indicates that rifle scope  10  is level within the predetermined angular tolerance, and reticle LED  82  is also powered. 
     To activate Mode  3 , the operator presses activation switch  52  once from Mode  2 . In Mode  3 , only reticle LED  82  is powered (see  FIG. 11 , input box  3 ). From Mode  3 , the operator presses activation switch  52  once again to reenter Mode  1  (see  FIG. 11 , input box  4 ). 
     In each of the Modes  1 ,  2 , and  3 , the operator can increase or decrease the intensity of the illuminated level LED  92  or reticle LED  82  of that mode by pressing illumination up switch  54  or illumination down switch  56 , as seen in  FIG. 3 . 
     In each of the Modes  1 ,  2 , and  3 , activation initiates the timer to run for a first predetermined amount of time. In one embodiment, the first predetermined amount of time is 3 minutes. Each detection of movement of rifle scope  10  by sensor  66  restarts the timer. In this manner, each of Modes  1 ,  2 , and  3  remain activated as long as there is any movement detected by sensor  66  within the first predetermined period of time. 
     As shown on the right side of  FIG. 11 , [AUTO NON-MOVEMENT TIME-OUT], in the absence of any detection of movement by sensor  66  before the expiration of the first predetermined period of time, circuit board  60  will automatically shift scope  10  into a fourth mode (Mode  4 ), which is a “sleep” mode. In Mode  4 , power to level LED  92  and reticle LED  82  is terminated, and battery power  62  is substantially (mostly) conserved. 
     As shown on the left side of  FIG. 11 , [AUTO MOVEMENT REACTIVATION] when in Mode  4 , detection of movement by sensor  66  before the expiration of a second predetermined period of time will cause scope  10  to revert to the last mode of operation (Modes  1 ,  2 , or  3 ) and to the illumination settings activated prior to automatically switching to Mode  4 . 
     In Mode  4 , the absence of detection of movement by sensor  66  before expiration of the second predetermined period of time will cause circuit board  60  to automatically power off scope  10  (Mode  0 ). See [AUTO NON-MOVEMENT SHUTDOWN]. When unpowered, no timers are running, no LEDs are powered, and battery power  62  is fully conserved. No movement of rifle scope  10  will cause it to power back up. It is then necessary to press activation switch  52  to cause scope  10  to power up in Mode  1 . 
     It will be understood to a person of ordinary skill in the art that the precise number and sequence of the modes of operation illustrated herein can be varied without departing from the novelty of the disclosure of the invention. 
       FIG. 12  is a front view of the embodiment of rifle scope  10  illustrated in  FIG. 1 . In this view, looking towards objective bell  30 , rifle scope  10  is shown in a level and non-canted position. 
       FIG. 13  is a rear view of the embodiment of rifle scope  10  illustrated in  FIG. 12 . This is the operator&#39;s view of rifle scope  10 . In this view, looking towards eyepiece assembly  20 , rifle scope  10  is shown in a level and non-canted position. 
     As seen in this view, and is conventional for rifle scopes, windage turret  42  is located on the operator&#39;s right side of rifle scope  10 . Elevation turret  44  is located on the top of rifle scope  10 . A parallax turret  46  is located on the left side of rifle scope  10 . Unique to the present invention is canting turret  50 , which extends from parallax turret  46 . 
       FIG. 14  is a rear view of the embodiment of rifle scope  10  illustrated in  FIG. 13  in which rifle scope  10  is shown in a non-level, canted position. Accelerometer  66  on circuit board  60  detects angle α. Circuit board  60  determines angle α to be within or in excess of the predetermined allowable canting angle (for example, 1°) and only illuminates level LED  92  when angle α is within the allowable canting angle. 
       FIGS. 15-20  illustrate the operator&#39;s view through ocular lens  70  of eyepiece  20  in accordance with one embodiment of the invention.  FIG. 15  illustrates a view of reticle  80  and level assembly  90  of rifle scope  10  in a non-powered mode (Mode  0 ). In this mode, reticle LED  82  and level LED  92  are not activated for illumination. As seen in this view, although not illuminated, the intersection of reticle  80  with bubble  100  indicates a non-canted inclination of rifle scope  10 . 
     This is extremely advantageous in that rifle scope  10  is operative even when its electrical power source is depleted. As long as reticle  80  intersects bubble  100 , the rifle is positioned within the predetermined amount of allowable tilt, and the operator need not look external to scope  10  for that determination. This is achieved by the precise design of the arc length of bubble  100  to represent the allowed angle of canting, and the positioning of level  98  is visible within optical lens  70  in alignment with reticle  80 . 
       FIG. 16  illustrates reticle  80  and level assembly  90  of rifle scope  10  in Mode  1 . In Mode  1 , only level LED  92  is activated for illumination, and level LED  92  only illuminates when rifle scope  10  is in a non-canted inclination. As illustrated, level  98  indicates a non-canted inclination, and level LED  92  is thus illuminated. In one embodiment, level LED  92  is colored green to indicate “go”. In one embodiment, the allowable amount of canting is less than one degree. 
       FIG. 17  illustrates rifle scope  10  still in Mode  1 , as in  FIG. 16 . However, in  FIG. 17 , rifle scope  10  is excessively canted to the left such that LED  92  is not illuminated. Reticle  80  does not intersect bubble  100 , confirming an excessively canted inclination. 
       FIG. 18  illustrates reticle  80  and level assembly  90  of rifle scope  10  in Mode  2 . In Mode  2 , level LED  92  remains active as in activation Mode  1 . In addition, LED  82  illuminates reticle  80 , regardless of the canting angle. This mode is most useful in low light shooting. This condition is associated with dusk and dawn, which are prime hunting hours. As illustrated in  FIG. 18 , rifle scope  10  is not canted in excess of the allowable limit (e.g., one degree) such that reticle  80  and level  98  are both illuminated. 
       FIG. 19  illustrates rifle scope  10  still in activation Mode  2 , as in  FIG. 18 . However, in  FIG. 19 , rifle scope  10  is excessively canted to the right such that level LED  92  is not illuminated. Level  98  confirms a right canted inclination in that reticle  80  does not intersect bubble  100 . LED  82  continues to illuminate reticle  80  for low light targeting. 
       FIG. 20  illustrates reticle  80  and level assembly  90  of rifle scope  10  in a third activation mode, or Mode  3 . In Mode  3 , LED  82  illuminates reticle  80 , as in Mode  2 . However, level LED  92  is not activated for illumination in Mode  3 . Lighting of reticle  80  with reticle LED  82  is desired for targeting in early morning or early evening when external lighting is reduced. The operator may still rely on level  98  for inclination. 
     In one embodiment, LED  82  is preferably a different color than level LED  92 . In one embodiment, level LED  82  is colored red to prevent confusion with level LED  92 , which is preferably green. 
     In operation, rifle scope  10  operates similar to a telescope. As light from the target is received through objective lens  72 , the image converges at a first focal plane reticle  80 . At the first focal plane, the image is inverted. The image passes through a picture reversal assembly and reaches a second focal plane in eyepiece assembly  20 . The magnification of the image is adjusted at the second focal plane. Eyepiece assembly  20  includes a diopter adjustment  22  to accommodate the operator&#39;s visual acuity, similar to the eyepiece on binoculars. 
     Reticle  80  can be located in front (front focal plane reticle) or behind (second focal plane reticle) the magnifying lens  24 . 
     To adjust magnification, the operator turns magnification adjustment  24 . A magnification lens moves toward objective lens  72  to increase magnification. The magnification lens moves toward ocular lens  70  to decrease magnification. 
     Windage turret  42  permits horizontal adjustments for wind. Elevation turret  44  permits vertical adjustments to compensate for the distance of the shoot. Parallax turret  46  permits focal length correction for long shots, bringing reticle  80  into focus with the target. 
     Unique to the present invention, canting turret  50  extends from parallax turret  46  to provide a conveniently controllable and reliable indication of proper level, or tilt of the rifle to which scope  10  is attached. This indication is provided both mechanically and electrically, and by viewing the level  98  or green level LED  92  as seen inside rifle scope  10 , and thus without interference with sighting of the target. Level  98 , in combination with reticle  80 , or indicia  102 , provides a non-electrically reliant indication of proper level. Illumination of level LED  92  provides a positive, “no look” indication the rifle is level and within the predetermined limit of canting. 
     As illustrated, the invention provides a unique solution to the engineering constraints and challenges of providing a rapid identification of any undesirable canting in the rifle position while targeting. The disclosed embodiments provide the advantage of allowing the operator to know if the cant of the rifle is acceptable while keeping full focus on the reticle  80 —target interface. In addition, the present embodiments allow the operator to determine if the cant of the rifle is acceptable without looking exterior of ocular lens  70  in the absence of an electrical power source  62  to scope  10 . 
     As will be appreciated by a person of ordinary skill in the art, the sequence of the modes disclosed above may be reordered in any desired sequence without adversely affecting the overall operation of rifle scope  10 , and without departing from the novelty and spirit of the disclosed invention. For example, the first and third modes could be reversed in order of operation. As another example, the second and third modes may be reversed in order of operation. 
     As used herein, the term “accelerometer” is intended for construction as meaning an instrument or sensor for measuring inclination and/or movement of the scope. 
     As used herein, the term “substantially” is intended for construction as meaning “more so than not”. 
     As used herein, the term “circuit board” is intended for construction as meaning a printed circuit board or microcomputer with sufficient electrical elements and programming to perform the functions disclosed herein. 
     Having thus described the present invention by reference to certain of its preferred embodiments, it is noted that the embodiments disclosed are illustrative rather than limiting in nature and that a wide range of variations, modifications, changes, and substitutions are contemplated in the foregoing disclosure and, in some instances, some features of the present invention may be employed without a corresponding use of the other features. Many such variations and modifications may be considered desirable by those skilled in the art based upon a review of the foregoing description of preferred embodiments. Accordingly, it is appropriate that the appended claims be construed broadly in a manner consistent with the scope of the invention.