Abstract:
A self-adjusting range finding optic system for finding aim for a rifle by acquiring the range to a target, calculating the estimated bullet drop based on the range to the target, adjusting the reticle to compensate for the estimated bullet drop and displaying the adjusted reticle on the optic to allow for an accurate shot.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to apparatus and method for finding aim for a firearm, and more particularly, to self-adjusting rifle-mounted optics. 
       BACKGROUND OF THE INVENTION 
       [0002]    Modern war fighters, i.e., soldiers, snipers, marksman use many different types of rifle-mounted optics to more effectively aim and engage a target while compensating for bullet drop, or the pull of gravity exerted on a bullet in flight that causes the bullet to drop to the ground. Current solutions require a user to compensate for bullet drop by manually lifting the barrel at his/her own discretion to ensure that the round reaches and strikes the target at the desire location. 
         [0003]    Currently, there are numerous rifle-mounted optics that attempt to compensate for bullet drop. Some optics provide reticles that are formed by physical tic marks on the internal optics of the sight, and that allow the user to estimate the effect of bullet drop at an estimated distance. Examples of these can be seen in scout/sniper optics, scopes or telescopic sights. However, the tic marks are oftentimes based off of physical characteristics of the target (i.e. shoulder width) that may drastically vary from target to target or from the user&#39;s point of view. Other common war fighter optics, red-dot sights and popular electro-optic sights utilize a see-through lens with a simple red-dot reticle that a user zeroes in on a target. These sights do not provide tics or any other form of adjustment other than intuition on the user&#39;s behalf. Again the user estimates the distance to the target, i.e., “range distance” and also the effect of bullet drop at that range distance. 
         [0004]    Laser range finders are a common tool utilized by soldiers, snipers, marksman and relate to many aspects of the duties of the war fighter. To date there has been no combination of a range finder and a rifle-mounted optic that provides range finding ability with automated bullet drop compensation. 
       SUMMARY OF THE INVENTION 
       [0005]    Wherefore, it is an object of the present invention to overcome the above mentioned shortcomings and drawbacks associated with the prior art. 
         [0006]    A further object of the present invention is to provide rifle-mounted optics having a range finding capability to detect the distance to the target and automatically adjust the reticle to compensate for the bullet-drop. 
         [0007]    Yet another object of the present invention is to enable automated calculation of estimated bullet drop and the real-time visual projection of an adjusted reticle onto the display of the optic, thereby enhancing the accuracy and efficiency of shooting by quick and accurate range-to-target identification, reticle adjustment and shot placement assistance. By providing the technology to calculate for bullet drop and an auto adjusting reticle on the optic, the user only has to focus on placing the fixed reticle on the center-mass of the target. This is a significant advantage to war fighters and increases the chances that soldiers may more safely and effectively engaged enemies. 
         [0008]    A further object of the present invention is to enable any soldier equipped with this self-adjusting rifle-mounted optic system to call in close air support (CAS) and indirect fire (including mortars and artillery) quicker and with greater accuracy than the current need for manual estimation, decreasing the need for additional weight bearing equipment designed and currently utilized to provide this ability. 
         [0009]    The present invention relates to a method for finding aim for a rifle comprising the steps of: acquiring a range to a target; calculating an estimated bullet drop based on the range to the target; adjusting a reticle to compensate for the estimated bullet drop; and displaying the adjusted reticle on the optic to allow for an accurate shot. 
         [0010]    The present invention also relates to a self-adjusting optic system for mounting on a firearm that comprises a range finder for acquiring a range to a target. A processor which calculates an estimated bullet drop based on the acquired range to the target. A reticle which is adjustable so as to compensate for the estimated bullet drop based on the acquired range to the target. An optic having a display device on which the adjustable reticle is displayed to facilitate an accurate shot with the firearm. 
         [0011]    The present invention also relates to method for finding aim for a firearm comprising steps of: initially aiming the firearm to align a fixed reticle in an optical scope of the firearm with a desired point of impact of a bullet on the target; actuating a range finder with a pressure switch to acquire a range to the target; transmitting the acquired range to the target to a processor; calculating, with the processor, a bullet drop based on the acquired range to the target; determining, with the processor, a position on a display device at which an adjusted reticle is to be displayed in the optical scope based on the calculated bullet drop; displaying the adjusted reticle on the display device in the optical scope in the determined position, the adjusted reticle defining an actual point of impact of the bullet on the target; and realigning the firearm such that the adjusted reticle is aligned with the desired point of impact of the bullet on the target. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         [0012]    The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate various embodiments of the invention and together with the general description of the invention given above and the detailed description of the drawings given below, serve to explain the principles of the invention. The invention will now be described, by way of example, with reference to the accompanying drawings in which: 
           [0013]      FIG. 1  is a diagrammatic view of a firearm on which a self-adjusting range finding optic system according to the invention is mounted; 
           [0014]      FIG. 2  is a plan view of the self-adjusting range finding optic system according to the invention and a portion of the firearm; 
           [0015]      FIG. 3  is diagrammatic view of the self-adjusting range finding optic system according to the invention; 
           [0016]      FIG. 4  is a diagram illustrating a line of sight through the self-adjusting range finding optic system and a target while range is being acquired; 
           [0017]      FIG. 4A  is a diagram of the view field of an optical scope from shooter&#39;s point of with the firearm oriented as shown in  FIG. 4  while range is being acquired; 
           [0018]      FIG. 5  is a diagram illustrating the line of sight through the self-adjusting range finding optic system as shown in  FIG. 4  with reticle adjustment; 
           [0019]      FIG. 5A  is a diagram of the view field of an optical scope from shooter&#39;s point of with the firearm aimed as shown in  FIG. 5  with reticle adjustment; 
           [0020]      FIG. 6  is a diagram illustrating the line of sight through the self-adjusting range finding optic system following user adjustment; 
           [0021]      FIG. 6A  is a diagram of the view field of an optical scope from shooter&#39;s point of with the firearm aimed as shown in  FIG. 5  following user adjustment; and 
           [0022]      FIG. 7  is schematic diagram illustrating a method for using a self-adjusting range finding optic system. 
       
    
    
       [0023]    It should be understood that the drawings are not necessarily to scale and that the disclosed embodiments are sometimes illustrated diagrammatical and in partial views. In certain instances, details which are not necessary for an understanding of this disclosure or which render other details difficult to perceive may have been omitted. It should be understood, of course, that this disclosure is not limited to the particular embodiments illustrated herein. 
       DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0024]    The present invention will be understood by reference to the following detailed description, which should be read in conjunction with the appended drawings. It is to be appreciated that the following detailed description of various embodiments is by way of example only and is not meant to limit, in any way, the scope of the present invention. 
         [0025]    Turning now to  FIGS. 1-3 , a brief description concerning the various components of the present invention will now be briefly discussed. As can be seen,  FIG. 1  depicts a firearm  2  including a trigger  4  which can be actuated by a user to fire a bullet through a barrel  6  and along a trajectory towards a target. A magazine  8  holds a number of cartridges such that when a bullet is discharged from the cartridge located in the firing chamber  10  at the end of the barrel  6 , the now empty cartridge is ejected from the firing chamber  10  and a new cartridge is transferred from the magazine  8  and loaded into the firing chamber  10 . Cartridges hold the bullet and enclose an amount of propellant, also called load which is ignited to shoot the bullet from the firearm  2 . A sight  12  is mounted to the firearm  2  and comprises a self-adjusting range finding optic system  13  having a sight housing  14 , an optical scope  16 , a range finder  18 , a display screen  20 , a processor  22 , a memory unit  24 , a power switch  26 , a source of electrical power  28 , a user input device  30 , an electronic port  32 , and variety of different sensors and instrumentation, which will be described in more detail below. 
         [0026]    The sight housing  14  is generally mounted at the top of the firearm  2  in the illustrated manner such that the line of sight  34  through the optical scope  16  (illustrated as a dashed line) and the axis of the barrel  36  (illustrated as a solid line) are at least substantially parallel. The sight housing  14  according to the current invention houses the elements of the self-adjusting range finding optic system  13  including the optical scope  16 , processor  22 , the display screen  20  and the electronic port  32 . The range finder  18 , power switch  26 , power source  28 , user input device  30  as well as the variety of different sensors and instrumentation can either be housed within or integrated on the sight housing  14 . It is however possible that one or more of these elements can be independent of the&#39;self-adjusting range finding optic system  13  and connected to thereto through the sight housing  14  by means of an input connection  38  which accepts simple communication, for example a USB connection. 
         [0027]    An electrical power source  28  can be either located within the sight housing  14  and connected, via electrical leads, to the elements arranged within the sight housing  14  or can be located outside the sight housing  14  and connected to the self-adjusting range finding optic system  13  by means of a power cable that can be received by a power port  42 . The power source  28  is formed by one or more removable batteries, the number and electrical power of which is generally based upon the configuration of the self-adjusting range finding optic system  13 , It is to be appreciated that the power source  28  can comprise a permanently enclosed battery that can be recharged via the power port  42 . 
         [0028]    The supply of electrical power to the self-adjusting range finding optic system  13  can be controlled by a power switch  26  such as a pressure switch  26 ′. As switches  26 ,  26 ′ for selectively connecting a power source  28  to an electrical consumer are generally well known, the electrical connections between the electrical power source  28  and the self-adjusting range finding optic system  13  will not be discussed in further detail here. In one variation of the self-adjusting range finding optic system  13 , the power switch  26  is arranged on the sight housing  14 . In another variation, the power switch  26 ′ is arranged at a location remote from the sight housing  14 . It is beneficial to position the power switch  26  at a location that does not necessitate the user from diverting his/her view from the target so as to activate the switch  26 ′ for example at a position adjacent the trigger guard  25 . In either case the electrical power switch  26 ,  26 ′ connects the power source  28  to the elements of the self-adjusting range finding optic system  13 . In another variation, a pair power switches  26 ,  26 ′ can be connected to the self-adjusting range finding optic system  13 . In this case, the self-adjusting range finding optic system  13  can have a first power switch located  26  located on the sight housing  14  which is utilized to initially “power up” the self-adjusting range finding optic system  13 . The second power switch  26 ′ is formed as a pressure switch which communicates with the self-adjusting range finding optic system  13  by way of a communication line  5 . The pressure switch  26 ′ is utilized to “wake up” the self-adjusting range finding optic system  13  from a “sleep mode.” A sleep mode of type of operation is utilized in a manner to conserve electrical energy when the self-adjusting range finding optic system  13  is not actively functioning. The pressure switch  26 ′ can be arranged near the trigger  4  within reach of the trigger finger on the firearm  2  so as to “wake up” the self-adjusting range finding optic system  13  at a time when the user is preparing to engage a target  48 . In this case, the pressure switch  26 ′ is located adjacent the trigger guard  25  such that when the user lifts and initially aims the firearm  2  in preparation for engaging the target  48 , the user is able to press the pressure switch  26 ′ with his/her trigger finger to activate the self-adjusting range finding optic system  13  without significant movement of the hand from it&#39;s current position. The pressure switch  26 ′ can communicate with signaling unit  44  such when the pressure switch  26 ′ is actuated, the signaling unit  44  issues an indicator signal to notify the user, for example, by means of a visual, audible or tactile signal that the self-adjusting range finding optic system  13  has been powered on. That is to say, when the pressure switch  26 ′ is actuated, a light can be illuminated or a beep or click can be produced. 
         [0029]    The sight  12  can be implemented using a layout that is common to many current war fighters and can include a telescopic sight such as scout/sniper sight which provides a fixed power magnification level, e.g., 3× magnification. The self-adjusting range finding optic system  13  can include a multifunction laser/illumination device, which can be connected to or rather integrated within the telescopic sight for enhancing precise aiming of the firearm  2 , target acquisition and illumination of a target and/or specific area. The multifunction laser device can include a red light laser and/or an IR laser. A red light laser is visible and can therefore assist the user with aiming the firearm when sighting the target with the naked eye. To sight the target in this manner, the user turns on the red laser light and points the firearm at the target. When viewed through the sight, the user is able to clearly see and align a red laser dot at the target. If properly calibrated for distance to the target, the red laser dot viewed on the target signifies the point of impact. One drawback of the red light laser is that it is visible by the target, thus providing the target with a warning of the impending shot. As the red light laser is visible, the position of the user may also easily be detected and therefore compromised. The IR laser on the other hand emits infra-red laser light which is generally not visible. The IR laser can be used in combination with a night-vision system which enables the infra-red light to be seen by the user. The IR laser/night-vision system together make it possible to illuminate targets in low light conditions without the target detecting visible light. Such a multifunction laser device can be integrated with the telescopic sight within the sight housing  14  or can be remote from the telescopic sight. If a remote multifunction laser device is utilized with the self-adjusting range finding optic system  13 , the laser device will include an output cable or the like that is able to be connected to the telescopic sight by way of the input connection  38 . The multifunction laser/illumination device further includes a floodlight which can be used in dark or rather low-light situations to assist in identifying targets. 
         [0030]    An important aspect of the self-adjusting range finding optic system  13  is the range finder  18 . As indicated above the range finder  18  can be arranged within or remote from the sight housing  14 , but in either case the range finder  18  is connected to or integral with the processor  22 . It is to be appreciated that the range finder  18  can also comprise the processor  22 . If the range finder  18  is remote from the sight housing  14 , the range finder  18  will communicate with the processor  22  by way of the input connection  38 . The range finder  18  can be a laser range finder which is utilized in conjunction with the multifunction laser device described above or the range finder  18  can be used instead the multifunction laser device. In the case that the range finder is utilized in conjunction with the multifunction laser device, the processor  22  communicates with and coordinates the function of both, such that the multifunction laser device will be controlled so as to emit coded-laser pulses  46 , while the range finder  18  is controlled by the processor  22  to detect the reflected laser light pulses  46 ′ and start and stop a timer  48  as discussed below in further detail. If the multifunction laser device is however not used in combination with the range finder  18 , the range finder  18  will perform both of these functions. In general, the laser range finder  18  can be actuated by the pressure switch  26 ′ when the user initially aims the firearm  2  at the target  48 . 
         [0031]    When actuated the laser range finder  18  directs focused coded pulses of laser light  46  at the target  48  and simultaneously starts a connected timer  48 . Upon striking the target  48 , the pulses of laser light  46  reflect off the target  48  and are directed back toward the user. That is to say, when the pulses of laser light hit  46  the target  48 , a portion of the laser light is reflected back to the laser range finder  18  mounted on the firearm  2 . The laser range finder  18  has a light sensor  50  which detects the reflected pulses of laser light  46 ′. Upon detecting the reflected laser light  46 ′, the laser range finder  18  stops the timer  48  and records the amount of time that has lapsed from the time the pulses of laser light  46  were emitted by the laser range finder  18  to the time the reflected pulses of laser light  46 ′ were detected by the light sensor  50 . As the speed at which light travels is known, the laser range finder  18  can calculate the distance to the target  48  based on the amount of time that had lapsed from the time the pulses of laser light  46  were emitted by the laser range finder.  18  to the time reflected pulses of laser light  46 ′ were detected by the light sensor  50 . The distance from the range finder  16 , i.e. the user, to the target  48  is hereinafter referred to as the “range distance”. 
         [0032]    It is to be appreciated that the range finder  18  can determine the range distance at a time selected by the user by actuating the pressure switch  26 ,  26 ′, or at certain intervals of time (for example, every second) or the range distance can be determined continuously. In the case that the range distance is continuously determined, the range distance will automatically change as the user aims the firearm at different targets. 
         [0033]    The inventive self-adjusting range finding optic system  13  utilizes an optical scope  16  having a fixed reticle  52  and a display screen  20  which is able to display a variable reticle  54 . The position at which the variable reticle  54  is displayed on the display screen  20  is controlled by the processor  22 , such that the position of the variable reticle  54  in the view field of the optical scope can be adjusted automatically depending on determined range distance range distances and, optionally, based on a number of other factors to be discussed below. 
         [0034]    The display screen  20  enables the user to view the variable reticle  54  in the optical scope  16  in addition to various other data and information that may be relevant to precise aiming of the firearm  2  on the target  48 . In one variation of the self-adjusting range finding optic system  13 , a “honeycomb” attachment of a telescopic sight or scope could be used as a display screen  20  on which the variable reticle  54  as well as other data and information, e.g., distance, direction and/or location are projected. Such a display screen  20  enables the user to view the variable reticle  54  and pertinent other data and information while at the same time maintaining a view of the target  48 . Another variation of the self-adjusting range finding optic system  13  may utilize an electro-optical sight having a 3× attachment as the sight  12  which allows the user to look through the optical scope  16  and adjust the aim of the firearm  2  based on the position of the variable reticle  54  in the view field of the optical scope  16 . A further variation may combine an electro-optical sight with a small prism which are used in combination to reflect the variable reticle  54 , data and information from a base onto the display screen  20 . In yet a further variation of the self-adjusting range finding optic system  13 , digital optics may be used to digitally project a variable reticle  54  in the sight picture. 
         [0035]    In any case a fixed reticle  52 , which may include a vertical crosshair  56  and horizontally aligned tick marks  58 , is permanently imprinted on or etched in the optics of the optical scope  16 . The variable reticle  54  on the other hand is projected as a red dot onto the display screen  20  and can be automatically adjusted in the manner described below so as to compensate for bullet drop based on the determined range distance as well as other factors that are known to cause changes in the trajectory  60  of a bullet. Although the figures illustrate the variable reticle  54  as a solid colored dot, it is to be appreciated that the variable reticle  54  can be displayed in any other form and color, for example crosshairs or an arrow head. The important aspect of the variable reticle  54  is that it be distinctly visible within the view field. 
         [0036]    Before describing the process of automatically adjusting the variable reticle  54 , a number of other factors will be discussed that can impact the trajectory  60  of a bullet and therefore negatively impact aiming of the firearm  2  based on the range distance. Such factors can include ballistic information, environmental information and geographic information. In addition to these factors, it is further possible to project system status information onto the display screen  20  such as the remaining supply of power in the power source  28  or the location coordinates of the target  48 . 
         [0037]    As briefly noted above, ballistic information can be taken into consideration when adjusting the variable reticle  54  in relation to the target  48  or rather aiming the firearm  2  on the target  48 . Ballistic information can include the size, shape, weight and grain of a bullet, the muzzle velocity, and perhaps characteristics of the barrel  6 . According to the invention such ballistic information can be input into the processor  22  of the self-adjusting range finding optic system  13  by a user input device  30 . The user input device  30  can include a keyboard, a number pad, and/or a touchpad and can facilitate communicating such information to the processor  22  as well as the other components of the self-adjusting range finding optic system  13 . An external user input device can communicate with the processor  22  by the input connection  38  located in the sight housing  14 . In another variant as shown in FIG.  2 , the user input device  30  is integrated into the sight housing  14  and comprises a series of buttons  62  which are pressed in correlation to the image shown on an interface screen  64 , such as an LCD that is located on the exterior of the sight housing  14 . 
         [0038]    The self-adjusting range finding optic system  13  can further include environmental instrumentation  66  such as sensors that respectively detect environmental and geographic information which might further alter the trajectory of a bullet. Such instrumentation  66  can communicate with the processor  22  and can include a barometer for measuring barometric pressure, a thermometer for measuring atmospheric temperature, a hygrometer for measuring the amount of humidity in the atmosphere, a wind vane and anemometer for measuring wind direction and speed, and an altimeter which can detect the altitude or rather the distance above sea level. External instrumentation (not shown) can transmit associated readings, data and information to the processor  22  via the input connection  38  or they may be integrally associated within the sight housing  14  of the self-adjusting range finding optic system  13 . 
         [0039]    The self-adjusting range finding optic system  13  can also have geographical instrumentation  68  such as an inclinometer which determines the incline/decline of the firearm  2  with respect to horizontal. As is known, shooting at a target  48  that is located at an incline or a decline from horizontal with respect to the shooter can alter the range distance. It is therefore desirable that an inclinometer be used in conjunction with the laser range finder  18  so as to more accurately calculate the range distance. When detected by the inclinometer, the angle of incline/decline with respect to horizontal is transmitted to the processor  22  and utilized in the range distance calculation. The geographical instrumentation  68  may also include a GPS and/or digital compass which can provide the self-adjusting range finding optic system  13  with geographic information such as location coordinates and direction orientation that can be relayed by the user when calling in close air support or indirect fire such as mortars and artillery. 
         [0040]    The method of using the self-adjusting range finding optic system  13  will now be described with reference to  FIGS. 4-6A .  FIGS. 4A ,  5 A, and  6 A depict a series of point-of-view diagrams (according to one embodiment) from the user&#39;s perspective looking down the optical scope  16 . Although  FIGS. 4A ,  5 A, and  6 A illustrate this embodiment as being implemented on scout/sniper type sight comprising the fixed reticle  52  as described above, it is to be appreciated that the self-adjusting range finding optic system  13  may be implemented for example on any other common war fighter optics, red-dot sights or an electro-optical sight. 
         [0041]    In the following description of the method of adjusting a range finding optic system  13 , it is to be understood that the axis of the barrel  36  and the line of sight  34  through the optical scope  16  always extend from the firearm  2  parallel with respect to each other. Further the fixed reticle  52  is permanently set in position in the view field of the optical scope  16 . That is to say the fixed reticle  52  does not move in relation to the line of sight  34  through the optical scope  16  and is therefore also fixed in position with respect to the axis of the barrel  36  of the firearm  2 . 
         [0042]    To initiate the method, the user raises the firearm  2  and looks through the optical scope  16  so as to identify the target  48  and adjust the firearm  2  such that the vertical crosshair  56  and horizontal tick marks  58  of the fixed reticle  52  are approximately centered horizontally on the target  48  as seen in  FIG. 4A . The user in addition aims the fixed reticle  52  at the target  48  such that the fixed reticle  52  is generally aligned with a desired point of impact  63  on the target  48  in accordance to what the user was trained to zero in on so as to eliminate the target  48 . The desired point of impact  63  on the target  48  is identified in the  FIGS. 4-5A  by means of an open dot. It is also to be appreciated that the user may view the target  48  through an optic with target identification. Although  FIG. 4A  indicates that the laser range finder  18  has not been yet been activated, as the variable reticle  54  is not shown in the view field of the optical scope  16 , it is to be understood that the laser range finder  18  may alternatively be activated prior to the initial identification of the target  48  and alignment of the fixed reticle  52  on the target  48 . The variable reticle  54  first appears in the view field the optical scope  16  when the self-adjusting range finding optic system  13  is actuated and the range distance is determined. 
         [0043]    The user then “wakes up” or rather activates the laser range finder  18  by actuating the pressure switch  26  in STEP  1 . As described above in more detail, upon being activated, the laser range finder  18  emits focused, coded pulses of laser light  46  at the target  48  which then strike the target  48  and reflect back toward the laser range finder  18 . The reflected pulses of laser light  46 ′ are then detected by the light sensor  50  of the laser range finder  18  at which point, in STEP  2 , the laser range finder  18  determines the distance to the target  48 , i.e., range distance based on the amount of time that it takes for the pulses of laser light  46  to travel to and return from the target  48 . The laser range finder  18  transmits the determined range distance to the processor  22  in STEP  3 . 
         [0044]    Depending at least on the determined range distance and the alignment of the fixed reticle  52  in relation to the target  48 , the processor  22  determines the appropriate location at which the variable reticle  54  is projected and set into position on the display screen  20  of the optical scope  16 . Once the variable reticle  54  is set in position with respect to the fixed reticle  52 , the variable reticle  54  and the fixed reticle  52  remain fixed in this arrangement until the bullet is shot, the user reactivates the laser range finder  18 , or it is detected that the range distance has changed. When activated, the variable reticle  54  is recognized as being the same as the actual point of impact of the bullet on the target  48  in STEP  4  and is illustrated in  5 - 6  as being a lack dot.  FIGS. 5 and 6  show the trajectory  60  of the bullet based on the determined range distance. As illustrated, the trajectory  60  of the bullet drops due to the pull of gravity as well as other factors generally described herein. As shown in  FIG. 5A , with the fixed reticle  52  being aligned on the target  48  in the manner described above in relation to  FIG. 5 , if the user were to take this shot without adjustment or realignment of the firearm  2  so as to compensate for bullet drop, the target  48  would have a higher chance of survival than a shot to center mass, thus leaving the user susceptible to the threat. In other words, if the bullet were shot while the firearm  2  was aligned using only the fixed reticle  52 , the actual point of impact of the bullet would not match the desired point of impact  63  of the bullet. The actual point of impact shown in  FIGS. 5 and 5A  and identified by the variable reticle  54  is significantly lower than the desired point of impact  63  as identified by the fixed reticle  52 . As stated above the trajectory  60  of a bullet can be impacted by a number of factors such as ballistic information, environmental information and geographic information for example. For this reason, the processor  22  communicates with the associated sensors and/or instruments and receives signals therefrom and subsequently considers these signals when determining the distance to the target  48 . To effectively utilize these factors when determining the range distance, the processor  22  is connected to a memory unit  24  which for example can store characteristic tables. It should be appreciated that the term “memory unit” herein is intended to include various types of suitable data storage media, whether permanent or temporary, such as transitory electronic memories, non-transitory computer-readable medium and/or computer-writable medium, With the variety of data and information that can be detected by the associated sensors and instrumentation, the processor  22  can access and utilize the characteristic tables so as to increase the accuracy of setting the position of the variable reticle  54  based on the detected range distance. As an example, one characteristic table can relate to the effect that the shape of the bullet has on the bullet trajectory or another characteristic table can relate to the effect that bullet weight has on the bullet trajectory. Thus with the ballistics information input by the user, the processor  22  accesses these ballistic characteristic tables to determine the measures by which bullet shape and/or weight alters the trajectory of the bullet over the detected range distance. The processor  22  then factors in the information gathered from the characteristic tables and the determined range distance when controlling the location at which the variable reticle  54  is projected and set on the display screen  20  of the optical scope  16 . 
         [0045]    Once the position of the variable reticle  54  is set in the view field in relation to the fixed reticle  52 , as in  FIG. 5A , the user then realigns the aim of the firearm  2  so as to compensate for the amount of bullet drop over the determined range distance. The user realigns the firearm  2  until the actual point of impact  54  matches the desired point of impact  63  as shown in  FIGS. 6 and 6A . In the illustrated example, the user lifts the end of the barrel  6  so as to raise the axis  36  of the barrel  6  and line of sight  34  through the optical scope  16 . As the variable reticle  54  is now set in position with respect to the fixed reticle  52 , both the fixed and variable reticles  52 ,  54  are also raised in relation to the target  48  when the user raises the view field. In  FIGS. 6 and 6A , the firearm  2  and the view field have been lifted such that the actual point of impact, as demarcated by the adjustable reticle  54 , is aligned with the desired point of impact  63  on the target  48 . In short, the user realigns his/her sight picture to utilize the variable reticle  54  when taking aim and engaging the target  48  in STEP  5 . 
         [0046]    While many varieties and/or embodiments of the present invention have been described in detail, it is apparent that various modifications and alterations of those embodiments will occur to and be readily apparent to those skilled in the art. However, it is to be expressly understood that such modifications and alterations are within the scope and spirit of the present invention, as set forth in the appended claims. Further, the self-adjusting range finding optic system described herein is capable of other embodiments and of being practiced or of being carried out in various other related ways. In addition, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having,” and variations thereof herein, is meant to encompass the items listed thereafter and equivalents thereof as well as additional items while only the terms “consisting of” and “consisting only of” are to be construed in a limitative sense.