U.S. patent application number 11/559101 was filed with the patent office on 2007-12-06 for telescopic sight and method for automatically compensating for bullet trajectory deviations.
This patent application is currently assigned to BUSHNELL PERFORMANCE OPTICS. Invention is credited to JOHN WILLIAM CROSS, WILLIAM C. PERKINS, JORDAN VERMILLION.
Application Number | 20070277421 11/559101 |
Document ID | / |
Family ID | 35597922 |
Filed Date | 2007-12-06 |
United States Patent
Application |
20070277421 |
Kind Code |
A1 |
PERKINS; WILLIAM C. ; et
al. |
December 6, 2007 |
TELESCOPIC SIGHT AND METHOD FOR AUTOMATICALLY COMPENSATING FOR
BULLET TRAJECTORY DEVIATIONS
Abstract
A telescopic sight (10) for automatically compensating for
bullet trajectory deviations is disclosed. The sight (10) includes
a user input (20) and an electronic port (22) for communicating
ballistic, calibration and user preference information to the sight
(10). The sight (10) further includes a ranger finder (24) and an
array of ambient condition sensors (26,28,30,32,34,36) for
automatically generating target distance information and ambient
condition information. A processor (38) uses the ballistic,
calibration, user preference, distance and ambient condition
information to calculate bullet trajectory deviation compensation
information. The processor (38) presents the compensation to the
user in the form of a compensation reticle (48) or a compensation
value (50).
Inventors: |
PERKINS; WILLIAM C.;
(LENEXA, KS) ; CROSS; JOHN WILLIAM; (OVERLAND
PARK, KS) ; VERMILLION; JORDAN; (OVERLAND PARK,
KS) |
Correspondence
Address: |
HOVEY WILLIAMS LLP
2405 GRAND BLVD., SUITE 400
KANSAS CITY
MO
64108
US
|
Assignee: |
BUSHNELL PERFORMANCE OPTICS
9200 CODY
OVERLAND PARK
KS
66214
|
Family ID: |
35597922 |
Appl. No.: |
11/559101 |
Filed: |
November 13, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10867429 |
Jun 14, 2004 |
|
|
|
11559101 |
Nov 13, 2006 |
|
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|
Current U.S.
Class: |
42/122 |
Current CPC
Class: |
F41G 1/38 20130101; F41G
1/473 20130101 |
Class at
Publication: |
042/122 |
International
Class: |
F41G 1/38 20060101
F41G001/38 |
Claims
1. A method of automatically compensating for deviations in a
bullet trajectory, the method comprising the steps of: (a)
receiving target distance information from a range finder; (b)
receiving ambient condition information from an ambient condition
sensor; (c) calculating bullet trajectory compensation information
based on the distance information and ambient condition
information; and (d) presenting the compensation information to the
user by presenting a compensation reticle within a field of view of
a telescopic sight, wherein the compensation reticle is adjusted
according to the compensation information to indicate a point of
impact of the bullet.
2. The method as set forth in claim 1, further comprising the step
of: (e) receiving ballistic information from the user and using the
ballistic information to calculate the compensation
information.
3. The method as set forth in claim 2, step (e) further comprising
the step of receiving a size, weight, shape and grain of a bullet,
a muzzle velocity, and firearm barrel characteristics from the user
to calculate the compensation information.
4. The method as set forth in claim 1, further comprising the step
of: (f) receiving calibration information from the user and using
the calibration information to calculate the compensation
information.
5. The method as set forth in claim 4, step (f) further comprising
the step of receiving from the user a value representing a range at
which a telescopic sight was zeroed and a value representing a
scope-barrel separation distance and using the values to calculate
the compensation information.
6. The method as set forth in claim 1, further comprising the step
of: (g) receiving user preference information from the user and
using the user preference information to calculate the compensation
information and to present the compensation information to the
user.
7. The method as set forth in claim 6, step (g) further comprising
the step of receiving from the user a list of ambient conditions to
include in a trajectory deviation calculation.
8. The method as set forth in claim 7, step (b) further comprising
the step of selectively receiving ambient condition information
from a sensor chosen from the group consisting of an altimeter, a
wind sensor, an inclinometer, a barometer, a thermometer, and a
humidity sensor.
9. The method as set forth in claim 6, step (g) further comprising
the step of receiving from the user a preferred manner of
presenting compensation information to the user, wherein a
compensation reticle may be preferred and a numerical value may be
preferred.
10. The method as set forth in claim 9, further comprising the step
of: (h) presenting the compensation value to the user by presenting
a compensation reticle within the field of view of the telescopic
sight if the user preference information indicates that a
compensation reticle is preferred.
11. The method as set forth in claim 10 further comprising the step
of: (i) presenting the compensation value to the user by presenting
a numerical value within the field of view of the telescopic sight
if the user preference information indicates that a numerical value
is preferred.
12. The method as set forth in claim 1, step (a) further comprising
the step of receiving target distance information from a laser
range finder and using the target distance information to calculate
the compensation information.
13. The method as set forth in claim 1, step (a) further comprising
the step of receiving target distance information from a
triangulation range finder.
14. The method as set forth in claim 1, further comprising the step
of: (j) downloading ballistic information from the Internet to a
computer, wherein the ballistic information includes a size,
weight, shape and grain of a bullet, firearm barrel
characteristics, and muzzle velocity.
15. The method as set forth in claim 14, further comprising the
step of: (k) saving the ballistic information in a computer file on
the computer.
16. The method as set forth in claim 15, further comprising the
step of: (l) adding calibration information to the computer file,
wherein the calibration information includes a distance at which a
telescopic sight was zeroed and a scope-barrel separation
distance.
17. The method as set forth in claim 16, further comprising the
step of: (m) adding user preference information to the computer
file, wherein the user preference information includes a list of
ambient conditions to include in a trajectory deviation calculation
and a preferred manner of presenting compensation information to
the user, wherein a compensation reticle may be preferred and a
numerical value may be preferred.
18. The method as set forth in claim 17, further comprising the
step of: (n) electronically communicating the computer file to the
telescopic sight.
19. The method as set forth in claim 18, further comprising the
step of: (o) storing the computer file in a nonvolatile memory in
the telescopic sight.
20. A method of automatically compensating for deviations in a
bullet trajectory, the method comprising the steps of: (a)
communicating ballistic information to a telescopic sight via a
number pad, wherein the ballistic information includes a size,
weight, shape and grain of a bullet and a muzzle velocity of a
firearm; (b) communicating calibration information to the
telescopic sight via the number pad, wherein the calibration
information includes a range at which a telescopic sight was zeroed
and a scope-barrel separation distance; (c) communicating user
preference information to the telescopic sight via the number pad,
wherein the user preference information includes a list of ambient
conditions to include in a trajectory deviation calculation, and
further includes a preferred manner of presenting compensation
information to the user, wherein a compensation reticle may be
preferred and a numerical value may be preferred; (d) receiving
distance information from a laser range finder, wherein the
distance information includes a distance to a target indicated by a
fixed reticle within a field of view of the sight; (e) receiving
ambient condition information from an ambient condition sensor
housed within the sight if the condition is included in the list of
ambient conditions; (f) storing the ballistic information,
calibration information, user preference information, distance
information, and ambient condition information in a nonvolatile
memory; (g) calculating bullet trajectory deviation compensation
information using the ballistic information, calibration
information, and ambient condition information; (h) presenting the
compensation information to the user by superimposing a
compensation reticle over the fixed reticle within the field of
view of the telescopic sight if the user preference information
indicates that a compensation reticle is preferred, wherein the
compensation reticle indicates a point of impact of the bullet in
light of bullet trajectory deviations; and (i) presenting the
compensation value to the user by superimposing a numerical value
over the field of view of the telescopic sight if the user
preference information indicates that a numerical value is
preferred, wherein the numerical value indicates a distance between
the point of impact indicated by the fixed reticle and an actual
point of impact.
Description
RELATED APPLICATIONS
[0001] The present application is a divisional patent application
and claims priority benefit, with regard to all common subject
matter, of earlier-filed U.S. nonprovisional patent application
titled "TELESCOPIC SIGHT AND METHOD FOR AUTOMATICALLY COMPENSATING
FOR BULLET TRAJECTORY DEVIATIONS," Ser. No. 10/867,429, filed Jun.
14, 2004. The identified earlier-filed application is hereby
incorporated by reference into the present application.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to telescopic sights that
assist a user in compensating for deviations in a bullet
trajectory. More particularly, the present invention relates to a
telescopic sight that uses ballistic information, ambient condition
information, and target distance information to automatically
determine a bullet trajectory deviation.
[0004] 2. Description of Prior Art
[0005] Hunters and other shooters commonly seek to improve their
shooting accuracy by availing themselves of the latest technology,
such as telescopic and holographic sights. Telescopic sights, also
known as "scopes" or "riflescopes," magnify a field of view and
superimpose a reticle, such as a pair of crosshairs, over the
magnified field of view. The reticle indicates a bullet's point of
impact, while the magnified field of view makes distant targets and
surrounding objects appear closer.
[0006] While scopes have effectively helped shooters improve their
accuracy, they are susceptible to inaccuracies, particularly as
shooting range increases. Such inaccuracies arise from several
factors, including scope calibration, ambient factors, and firearm
ballistics.
[0007] The imperfect nature of scope calibration compromises
reticle accuracy at many ranges. When a scope is attached to a
firearm, it must be calibrated so that the reticle accurately
indicates a point of impact of the bullet. Because the line of
sight of a scope does not correspond perfectly with bullet
trajectory, a scope is calibrated so that the reticle indicates the
point of impact of a bullet at a particular distance from the
firearm, a process known as "zeroing." A scope may be zeroed, for
example, at a range of 50 or 100 yards. It will be appreciated that
when a scope is zeroed, the reticle accurately indicates the point
of impact of the bullet only in the absence of arbitrary ambient
conditions that affect the trajectory of the bullet, as described
in greater detail below. Furthermore, at ranges other than the
range at which the firearm was zeroed, particularly ranges well
beyond the zeroing range, the actual point of impact of the bullet
may be different than the point of impact indicated by the reticle
because the line of sight of the scope has diverged from the bullet
trajectory.
[0008] Ambient, or external, factors also have an increasing effect
on the trajectory of a bullet as shooting range increases. One such
factor is gravity, which causes "bullet drop." Bullet drop is
characterized by a bullet path which curves toward the earth over
long ranges as the bullet falls to the ground. To hit a target at
long range, therefore, it is necessary to compensate for bullet
drop by elevating the barrel of the firearm, and, thus, the aiming
point. Wind is another ambient factor that can influence bullet
trajectory. Wind can cause the bullet to drift to the left or to
the right of the central path of the bullet over a long range. Such
effects are commonly referred to as "windage" effects. To hit a
target at long range, therefore, it may be necessary to compensate
for windage effects by moving the barrel of the firearm slightly to
the left or to the right to compensate for bullet drift. Other
ambient factors that may affect the trajectory of a bullet include
firearm inclination, barometric pressure, humidity, altitude and
temperature.
[0009] Ballistics, or the internal actions and characteristics of
the firearm, also affect bullet trajectory and must be compensated
for at long ranges. Ballistics include such factors as the weight,
size (caliber), shape and grain of the bullet; firearm barrel
characteristics; and muzzle velocity, or the speed at which the
bullet leaves the muzzle of the firearm. It will be appreciated
that these factors vary from one firearm to another, and from one
type of bullet to another.
[0010] When using a scope, then, a shooter must attempt to
compensate for inaccuracies by estimating a distance to a target,
estimating the effect of calibration, ambient conditions and
ballistics on the bullet trajectory, and use these estimates to
properly position the barrel of the firearm prior to squeezing the
trigger. It will be appreciated that the inaccuracies described
above may be significant enough at extreme ranges to entirely
compromise the benefits of using a scope.
[0011] Devices that assist shooters in compensating for these
inaccuracies are well known in the art. Laser range finders, for
example, such as the YARDAGE PRO.TM. series of range finders sold
by BUSH NELL.TM., assist shooters by accurately determining target
range--thus eliminating the uncertainty inherent in guessing the
range. With a laser range finder, the shooter merely needs to aim
the rangefinder at the target, press a button, and read a range
display.
[0012] Telescopic sights that assist a user in compensating for
inaccuracies are also known in the art. The "mildot" reticle, for
example, uses small, evenly-spaced dots to assist a shooter in
determining a target range. The mildot reticle requires a shooter
to know the approximate size of the target, and to know and apply a
mathematical formula for determining the range. Once the range is
determined, the shooter must estimate the amount of compensation
necessary to compensate for deviations in the bullet trajectory.
More sophisticated telescopic sights go further in helping the
shooter to compensate for such deviations.
[0013] U.S. Pat. No. 6,269,581 (the '581 patent), for example,
discloses a telescopic sight that employs an integral laser range
finder and processor to calculate the amount of compensation
necessary to correct for deviations in the bullet trajectory. The
sight of the '581 patent requires the user to manually enter an
altitude value and a muzzle velocity, while the sight determines a
target range using the laser range finder. Using the values
manually entered by the user and the target range, the sight
calculates a compensation and presents a second set of crosshairs
that assist the user in compensating for bullet trajectory
deviations by indicating the point of impact of the bullet in light
of the trajectory deviations.
[0014] The prior art laser range finders and scopes are subject to
several undesirable limitations. First, they fail to include
factors that may contribute to deviations in the bullet trajectory.
The telescopic sight of the '581 patent, for example, does not
compensate for such ambient factors as barometric pressure,
windage, or humidity; nor does it compensate for scope calibration.
Second, they require a shooter to be aware of and/or manually
submit certain pieces of information. To effectively use the
telescopic sight of the '581 patent, for example, a user must be
aware of his or her altitude and submit altitude information to the
sight. It will be appreciated that these limitations may result in
a delayed or missed shot.
[0015] Thus, a need exists for a telescopic sight that can assist a
user in compensating for deviations in a bullet trajectory arising
from firearm calibration, ambient factors, and firearm ballistics
by eliminating the need for the user to estimate or calculate
deviation information prior to shooting. Furthermore, a need exists
for a firearm scope that does not require the user to be aware of
or communicate to the sight ambient condition information and
target distance information.
SUMMARY OF THE INVENTION
[0016] The present invention provides an improved telescopic sight
for automatically compensating for bullet trajectory deviations
that does not suffer from the problems and limitations of the prior
art described above. Particularly, the present invention provides a
telescopic sight with integral range finder and ambient condition
sensors, wherein the sight can automatically calculate bullet
trajectory deviation compensation information based on a target
range and ambient conditions acquired by the sight, and calibration
and ballistic information submitted by a user. The sight presents
the compensation information to the user in a convenient way to
allow the user to compensate for bullet trajectory deviations. The
improved sight thus eliminates the need for the user to be aware of
ambient condition information or target distance information, or
communicate the information to the sight.
[0017] In one embodiment, the invention features a telescopic sight
for automatically compensating for deviations in a bullet
trajectory. The sight comprises a range finder for generating
target distance information, a sensor for generating ambient
condition information, a processor for calculating bullet
trajectory compensation information using the target distance
information and the ambient condition information, and an optical
scope. The optical scope receives the compensation information from
the processor, presents a magnified view of a target area to the
user, and presents the compensation information to the user.
[0018] In another embodiment, the sight includes a keypad for
receiving ballistic information and calibration information from
the user and an electronic port for receiving the ballistic
information and calibration information from an external electronic
device. A laser range finder generates target distance information,
wherein the distance information indicates a distance between the
sight and a target. A wind sensor generates windage information,
wherein the windage information includes a wind direction and a
wind speed. A processor calculates bullet trajectory compensation
information using the ballistic information, calibration
information, target distance information, and windage information.
Finally, an optical scope magnifies a view of a target area and
presents a compensation reticle within the magnified view, wherein
the compensation reticle is adjusted according to the compensation
information to indicate a point of impact of the bullet.
[0019] In another embodiment, the sight includes a keypad for
receiving ballistic information, calibration information, and user
preference information from the user. The ballistic information
includes a size, shape, grain and weight of a bullet, a muzzle
velocity, and firearm barrel characteristics. The calibration
information includes a range at which the sight was zeroed and a
scope-barrel separation distance. The user preference information
includes a list of ambient conditions to include in a bullet
trajectory compensation calculation and a preferred manner of
presenting compensation information to the user. An electronic port
receives the ballistic information, the calibration information,
and the user preference information from an external electronic
device. A laser range finder generates target distance information,
wherein the distance information indicates a distance between the
sight and a target.
[0020] The sight may further include ambient condition sensors,
including an altimeter for generating altitude information; a
barometer for generating barometric pressure information; a
thermometer for generating temperature information; a humidity
sensor for generating humidity information; and a wind sensor for
generating windage information, wherein the windage information
includes a wind direction and a wind speed. A processor calculates
bullet trajectory compensation information using the ballistic
information, calibration information, and ambient condition
information. The processor selectively uses the target distance
information, altitude information, barometric pressure information,
temperature information, humidity information, and windage
information according to the user preference information. A
nonvolatile memory element receives information from the processor,
stores the information, and communicates the information to the
processor. Finally, an optical scope magnifies a view of a target
area and presents a compensation reticle within the magnified view,
wherein the compensation reticle is adjusted according to the
compensation information to indicate a point of impact of the
bullet.
[0021] In another aspect, the invention features a method of
assisting a user in compensating for deviations in a bullet
trajectory. The method comprises the steps of receiving target
distance information from a range finder, receiving ambient
condition information from an ambient condition sensor, calculating
bullet trajectory compensation information based on the distance
information and ambient condition information, and presenting the
compensation information to the user by presenting a compensation
reticle within a field of view of a telescopic sight, wherein the
compensation reticle is adjusted according to the compensation
information to indicate a point of impact of the bullet.
[0022] In another embodiment, the method comprises the steps of
communicating ballistic information to a telescopic sight via a
number pad, communicating calibration information to the telescopic
sight via the number pad, and communicating user preference
information to the telescopic sight via the number pad. The
ballistic information includes a bullet size, weight, shape and
grain, a muzzle velocity, and firearm characteristics. The
calibration information includes a range at which a telescopic
sight was zeroed and a scope-barrel separation distance. The user
setting information includes a list of ambient conditions to
include in a trajectory deviation calculation, and further includes
a preferred manner of presenting compensation information to the
user, wherein a compensation reticle may be preferred and a
numerical value may be preferred.
[0023] The method may further comprise the steps of receiving
distance information from a laser range finder, wherein the
distance information includes a distance to a target indicated by a
fixed reticle within a field of view of the sight, and receiving
ambient condition information from an ambient condition sensor
housed within the sight if the condition is included in the list of
ambient conditions. The method further comprises the steps of
storing the ballistic information, calibration information, user
preference information, distance information, and ambient condition
information in a nonvolatile memory; calculating a bullet
trajectory deviation compensation value based on the information
solicited; and presenting the compensation value to the user by
superimposing a compensation reticle over the fixed reticle within
the field of view of the telescopic sight if the user preference
information indicates that a compensation reticle is preferred,
wherein the compensation reticle indicates a point of impact of the
bullet in light of bullet trajectory deviations. Finally, the
method comprises the step of presenting the compensation value to
the user by superimposing a numerical value over the field of view
of the telescopic sight if the user preference information
indicates that a numerical value is preferred, wherein the
numerical value indicates a distance between the point of impact
indicated by the fixed reticle and an actual point of impact.
[0024] Other aspects and advantages of the present invention will
be apparent from the following detailed description of the
preferred embodiments and the accompanying drawing figures.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] A preferred embodiment of the present invention is described
in detail below with reference to the attached drawing figures,
wherein:
[0026] FIG. 1 is a perspective view of a telescopic sight for
automatically compensating for bullet trajectory deviations
constructed in accordance with a preferred embodiment of the
present invention;
[0027] FIG. 2 is a side elevation view of the telescopic sight
illustrated in FIG. 1;
[0028] FIG. 3 is a schematic of components of the telescopic sight
illustrated in FIG. 1;
[0029] FIG. 4 is a fragmented view of a field of view presented by
the telescopic sight illustrated in FIG. 1, wherein a fixed reticle
is visible;
[0030] FIG. 5 is a fragmented view of a field of view presented by
the telescopic sight illustrated in FIG. 1, wherein the fixed
reticle and a trajectory compensation reticle are visible;
[0031] FIG. 6 is a fragmented view of a field of view presented by
the telescopic sight illustrated in FIG. 1, wherein the fixed
reticle and a trajectory compensation value are visible; and
[0032] FIG. 7 is a flowchart of steps involved in a method of
automatically compensating for bullet trajectory deviations.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0033] Referring to FIG. 1, a telescopic sight 10 is shown
constructed in accordance with a preferred embodiment of the
present invention and shown attached to a firearm 11. The sight
generally assists a user in compensating for variations in a bullet
trajectory by receiving calibration and ballistic information,
generating ambient condition information and target distance
information, calculating bullet trajectory compensation
information, and presenting the compensation information to the
user. As illustrated in FIGS. 2-3, the sight 10 comprises a housing
12; a power switch 18, a user input 20; an electronic port 22; a
range finder 24; ambient condition sensors 26,28,30,32,34,36; a
processor 38; a nonvolatile memory 40; a display 42; an optical
scope 44; and a power source.
[0034] The housing generally encloses and protects the other
components of the sight 10, and provides a means of attaching the
sight 10 to the firearm 11. Turning now to FIG. 2, the illustrated
housing 12 is substantially cylindrical in shape and is preferably
constructed of plastic, aluminum or other lightweight and sturdy
material. The housing 12 is large enough to contain the other
components of the sight 10 but small enough to conveniently attach
to a rifle or other firearm without interfering with the use or
transport of the firearm 11. The housing 12 is preferably
waterproof or water resistant and as such may include one or more
gaskets or seals (not shown). Mounting brackets 14,16 on the
housing 12 secure the sight 10 to the firearm 11 in a manner
commonly known in the art. Although the illustrated housing 12 is
shown and described as being substantially cylindrical in shape, it
will be appreciated that the housing may be of various shapes and
sizes intended for utility, aesthetic, or ergonomic purposes,
including, for example, a substantially rectangular shape.
[0035] The power switch generally allows the user to activate the
electronic components of the sight 10 by connecting those
components to the power source, and further allows the user to
deactivate the electronic components of the sight 10 by
disconnecting those components from the power source. The
electronic components powered by the power source collectively
comprise a trajectory compensation system, which compliments the
traditional functions of the telescopic sight 10 by presenting
trajectory compensation information to the user, as explained below
in greater detail. The illustrated power switch 18 has an "on"
state and an "off" state, wherein switching the power switch to the
"on" state activates the compensation system, and switching the
power source to the "off" state deactivates the compensation
system.
[0036] Referring also to FIG. 3, the user input generally provides
a means whereby a user may communicate information, such as
ballistic or calibration information, to the processor 38 and other
components of the sight 10. The illustrated user input 20 includes
a number pad that allows a user to communicate numerical values and
other messages to the processor 38 by depressing buttons on the
pad. The user input 20 may cooperate with other components of the
sight 10, such as the display 42, to facilitate communications
between the user and the processor 38, as explained below in
greater detail. It will be appreciated that the user input may
include a keypad or other type of human input device in place of or
in addition to the illustrated number pad.
[0037] The electronic port generally provides means to
communicatively connect the sight 10 to an external electronic
device so that the sight 10 and the external device may
electronically share information, such as calibration and ballistic
information. The illustrated electronic port 22 comprises a
Universal Serial Bus (USB) port of the type commonly found in
modern computers and other electronics. The USB provides serial
data communications between two devices, typically a computer and a
computer peripheral device. The USB is convenient to use because
devices may be connected to and removed from the bus without the
need to turn off any device on the bus, a process known as "hot
swapping." It will be appreciated that various types of electronic
ports may be used in place of or in addition to the USB port,
including, for example, an IEEE 1394 (commonly referred to as
"Firewire") port, or a Bluetooth or WiFi wireless port.
[0038] The electronic port 22 greatly facilitates the communication
of information to the sight 10. For example, a user may download
ballistic information relating to a particular firearm or a
particular type of bullet from the Internet or other computer
network to a computer. The user then connects the sight 10 to the
computer via the electronic port 22 and downloads the ballistic
information to the sight 10. Furthermore, the user may create and
store a data file on the computer that includes calibration
information manually submitted by the user as well as the ballistic
information downloaded from the Internet. The user may save the
file, change it, and communicate it to the sight 10 via the
electronic port 22 at the user's convenience.
[0039] The range finder generally determines a distance to a target
and communicates that distance to the processor 38 or to the user.
The illustrated range finder 24 is contained within the housing 12
and uses laser range finding technology to measure a distance to a
target that is within the field of view of the optical scope 44 and
indicated by a reticle of the scope 44, as explained below in
greater detail. The range finder 24 measures the distance upon
receiving a distance information request from the processor 38 and
communicates distance information to the processor 38 or to the
user.
[0040] The range finder 24 may communicate distance information to
the processor 38, for example, by electronically communicating to
the processor 38 an integer value representative of the distance
between the sight 10 and a target in meters or yards. The range
finder 24 may communicate distance information to the user, for
example, by communicating an electronic signal to the display 42
that enables the display 42 to show the distance in a human
readable form. It will be appreciated that the range finder may
include functionality not set forth above and may use various range
finding technologies or methods without departing from the scope of
the present invention. For example, the range finder may use
triangulation to measure the distance instead of laser range
finding technology.
[0041] The ambient condition sensors generally sense a variety of
ambient conditions that may affect the trajectory of a bullet, and
communicate ambient condition information to the processor 38 or to
the user. The illustrated ambient condition sensors include an
altimeter 26, a wind sensor 28, an inclinometer 30, a barometer 32,
a thermometer 34, and a humidity sensor 36. The altimeter 26
generates altitude information relating to the sight 10, such as a
value representing feet above see level. The wind sensor 28
generates windage information, such as a wind vector, wherein the
vector includes both a wind direction and wind speed. The
inclinometer 30 generates inclination information, such as an angle
at which a barrel of the firearm 11 deviates from a level position
relative to the earth's surface. The barometer 32 generates
barometric pressure information, such as a value in inches
representing an ambient barometric pressure. The thermometer 34
generates temperature information, such as a value representing an
ambient temperature at the location of the sight 10 in degrees
Fahrenheit. The humidity sensor 36 generates humidity information,
such as a value representing relative or absolute ambient
humidity.
[0042] Each sensor preferably generates and communicates
information in response to an ambient condition information request
communicated by the processor 38. Limiting the operation of the
ambient condition sensors in this way preserves energy that
otherwise would be lost through unneeded operation of the sensors
and prolongs the life of the power source of the sight 10. It will
be appreciated that the list of ambient sensors described and shown
is not comprehensive, and that other sensors may be used to
generate information relating to ambient conditions affecting
bullet trajectory.
[0043] The processor generally receives information, such as the
calibration information, ballistic information, and the ambient
condition information, generates bullet trajectory compensation
information, and communicates the information to the user. The
illustrated processor 38 is a digital computer processor and
includes integral clock and memory elements (not shown) and may be
a model that is commercially available. The processor 38 is
operable to receive information from the user input 20 and from the
electronic port 22, and to communicate information to the
electronic port 22. The processor 38 is further operable to request
information from the range finder 24 and from each of the ambient
condition sensors 26,28,30,32,34,36. The processor 38 is further
operable to store information in the nonvolatile memory 40, and to
retrieve the information from the nonvolatile memory 40. The
processor 38 is further operable to communicate information to the
optical scope 44 and to the display 42, wherein the information is
presented to the user in a human-readable form.
[0044] The nonvolatile memory generally receives and stores data,
wherein the data persists while power is removed from the memory.
The illustrated nonvolatile memory 40 is Flash memory and is
operable to receive and store data from the processor 38, and
communicate the information to the processor 38. Because the
integrity of the data persists indefinitely even when power is not
applied to the memory 40, the user may communicate information to
the telescopic sight 10 days or weeks before using it. The
nonvolatile memory 40 is preferably integral with the sight 10 and
contained within the housing 12. Alternatively, the nonvolatile
memory 40 may be removable.
[0045] The display generally allows the processor 38 to communicate
information to the user. The illustrated display 42 is a liquid
crystal display (LCD), but it will be appreciated that the display
may be of any type suitable for presenting information to the user
in human-readable form, such as, for example, a seven-segment LED
array. The display 42 cooperates with the user input 20 in
communicating with the user. For example, the display 42 may
display a message prompting the user to submit a value via the user
input 20, and then reflect the input that the user submits. It will
be appreciated that the user input 20 and the display 42 may be
combined in, for example, an LCD touchscreen.
[0046] The optical scope generally magnifies a field of view and
presents the bullet trajectory deviation compensation information
to the user. The illustrated optical scope 44 magnifies the field
of view in a manner known in the art and superimposes a fixed
reticle 46 over the field of view, as illustrated in FIG. 4. In the
illustrated embodiment the fixed reticle 46 is a set of crosshairs.
With respect to the fixed reticle 46, the sight 10 provides means
(not shown) to calibrate, or zero, the fixed reticle in a
traditional manner.
[0047] The optical scope 44 further presents the bullet trajectory
compensation information to the user. The scope 44 selectively
presents the compensation information to the user as a compensation
reticle 48, illustrated in FIG. 5, or as a compensation value 50,
illustrated in FIG. 6. The compensation reticle 48 is superimposed
over the magnified field with the fixed reticle 46, and indicates
the point of impact of the bullet in light of the compensation
information generated by the processor 38. The compensation value
50 is also superimposed over the magnified field of view and
indicates, for example, a distance in inches that an actual point
of impact of the bullet deviates from the point of impact indicated
by the fixed reticle 46.
[0048] In use, the user communicates ballistic information and
calibration information to the telescopic sight 10. The sight 10
senses ambient conditions to generate ambient condition information
and, using the information communicated by the user as well as the
ambient condition information, presents bullet trajectory
compensation information to the user. The user then adjusts his or
her aim of the firearm 11 according to the compensation information
presented by the sight 10.
[0049] It will be appreciated that the user may choose to use the
sight 10 without the aide of the trajectory compensation system and
rely entirely on the fixed reticle 46. To do so the user leaves the
power switch 18 in the "off" position, thus leaving the
compensation system deactivated. In that state, the fixed reticle
46 is visible in the field of view of the optical scope 44 and
indicates a point of impact of the bullet according to the
calibration of the scope 44. A user may desire to use the sight 10
without the aide of the compensation system if, for example, he or
she is shooting at close ranges only. As explained above in the
section entitled "DESCRIPTION OF PRIOR ART," however, the accuracy
of the fixed reticle 46 may be compromised by scope calibration,
ambient factors and firearm ballistics, particularly at longer
ranges.
[0050] Turning now to FIG. 7, to use the trajectory compensation
system of the telescopic sight 10, the user first activates the
compensation system by switching the power switch 18 to the "on"
position. The telescopic sight 10 then allows the user to
communicate ballistic information to the sight 10, as depicted in
block 52. The user communicates the information to the sight 10 via
the user input 20, and the ballistic information may include a
size, weight, shape and grain of a bullet; firearm barrel
characteristics; and/or a muzzle velocity.
[0051] The sight 10 then allows the user to communicate calibration
information to the sight 10, as depicted in block 54. The
calibration information includes a distance at which a telescopic
sight 10 was zeroed and a scope-barrel separation distance. As
described above in the section entitled "DESCRIPTION OF PRIOR ART,"
the distance at which the scope 44 was zeroed is the distance from
the firearm at which the fixed reticle 46 of the optical scope 44
accurately indicates the point of impact of the bullet absent
ambient conditions which may arbitrarily influence the bullet's
path, such as wind. This distance may be known by the user, or
obtained from the manufacturer of the firearm or other person who
calibrated the sight 10. The scope-barrel separation distance is
the distance between the line of sight of the optical scope 44 and
the path of the bullet as it leaves the muzzle of the firearm.
Together, the distance at which the sight 10 was zeroed and the
scope-barrel separation distance can be used to determine the rate
at which the line of sight of the optical scope 10 and the
trajectory of the bullet converge and diverge.
[0052] The sight 10 then allows the user to communicate user
preference information to the sight 10, as depicted in block 56.
The user preference information includes a list of ambient
conditions to include in a trajectory deviation calculation, and
further includes a preferred manner of presenting compensation
information to the user. Thus, the user can control which ambient
conditions the sight 10 will automatically compensate for by
including only those conditions in the list. For example, a user
may wish to use the wind sensor 28 only when there is a reliable
indication that the wind conditions are uniform between the user
and the target.
[0053] The preferred manner of presenting compensation information
may be via the compensation reticle 48, via the numerical value 50,
or both. The compensation reticle 48 indicates a point of impact of
the bullet taking into account the bullet trajectory compensation
information calculated by the processor 38. The compensation
reticle 48, preferably a set of crosshairs, has the advantage of
being very convenient and easy to use. To further facilitate use,
the compensation reticle 48 may be, for example, of a different
color than the fixed reticle 46.
[0054] The numerical value 50 communicates to the user a distance
between the point of impact of the bullet indicated by the fixed
reticle 46 and an actual point of impact of the bullet. The value
"3," for example, displayed in FIG. 6, may indicated that the
actual point of impact of the bullet will be three inches below the
point of impact indicated by the fixed reticle 46. It will be
appreciated that there are various ways of numerically representing
the trajectory deviation value that are within the scope of the
invention. The numerical value may be positive or negative, for
example, wherein a positive number represents a distance above a
point indicated by a horizontal crosshair or to the right of a
point indicated by a vertical crosshair, and a negative number
represents a distance below the point indicated by the horizontal
crosshair or to the left of the point indicated by the vertical
crosshair, or vice versa. Furthermore, a first numerical value may
be placed near the horizontal crosshair to represent a distance
from the point indicated by the horizontal crosshair, and a second
numerical value may be placed near the vertical crosshair to
represent a distance from the point represented by the vertical
crosshair.
[0055] The user may communicate the ballistic information, the
calibration information, and the user preference information to the
sight 10 just before shooting, or may communicate the information
well in advance of using the sight 10. A user may desire to
communicate the information to the sight 10 on the night before a
hunt, for example, or even days or weeks before the hunt. In that
case the user activates the compensation system of the sight 10 and
communicates the information to the sight 10, as described above,
and then turns off the compensation system. The information is
stored in the nonvolatile memory 40 and therefore is available when
the system is activated again. Furthermore, while it is preferred
that the user submit the ballistic, calibration, and preference
information, it will be appreciate that such information is not
necessary to the operation of the sight 10 and the sight may be
used without submitting such information, although accuracy may be
at least partially compromised if the information is omitted.
[0056] When the user is targeting an object, the sight 10 acquires
target distance information and ambient condition information for
use in calculating the bullet trajectory deviation. The processor
38 first solicits target distance information from the range finder
24, as depicted in block 58. This may be done, for example, by
communicating an electronic signal to the range finder 24. Upon
receiving the request for target distance information, the range
finder 24 acquires a distance to the target indicated by the fixed
reticle 46 of the optical scope 44, as explained above in greater
detail. Upon acquiring the target distance information, the range
finder 24 communicates the information to the processor 38 via an
electronic signal.
[0057] The processor 38 also solicits ambient condition information
from one or more of the ambient condition sensors
26,28,30,32,34,36, as depicted in block 60. The processor 38
reviews the list of sensors included in the user preference
information and solicits information only from those sensors
included in that list. The processor 38 solicits the information
from the sensors by communicating an electronic signal to each of
the sensors included in the list. Each of the sensors that is
solicited senses an ambient condition according to the
functionality explained above. Upon acquiring the ambient condition
information, each sensor communicates the information to the
processor 38 via an electronic signal.
[0058] After receiving the ballistic information, the calibration
information, the user preference information, the target distance
information, and the ambient condition information, the processor
38 stores all of the information in the nonvolatile memory 40, as
depicted in block 62. It will be appreciated that the processor 38
need not store the information in the nonvolatile memory 40 to
perform the calculations, as the information may be stored in a
memory (not shown) integral with the processor 38 for faster
processing. Storing the information in the nonvolatile memory 40,
however, ensures that the information will be available even after
the sight 10 is turned off or there is otherwise a disruption of
power to the processor 38.
[0059] After all of the information has been received, the
processor 38 calculates bullet trajectory deviation compensation
information based on the information, as depicted in block 64. The
compensation information indicates a distance or distances from the
point of impact of a bullet indicated by the fixed reticle the
actual impact will be, in light of the various pieces of
information generated by the sensors and communicated by the user.
The compensation information preferably includes two values, a
horizontal distance and a vertical distance. The horizontal
distance is the distance in inches the actual point of impact will
be on the target above or below a horizontal crosshair, while the
vertical distance is the distance in inches the actual point of
impact will be on the target to the left or to the right of a
vertical crosshair. Alternatively, the compensation information may
include a vector, such as a direction and a distance, wherein the
direction is a direction of the actual point of impact from the
point of impact indicated by the fixed reticle 44 and the distance
is the distance between the two points.
[0060] Methods of calculating bullet trajectory deviation
information from ballistic, calibration and ambient condition
information are known in the art. The processor 38 may use
algorithms corresponding to any of the methods to calculate the
compensation information.
[0061] After calculating the compensation information, the
processor 38 presents the information to the user, as depicted in
block 66. The compensation information may be presented to the user
as a compensation reticle 48, a compensation value 50, or both. The
compensation reticle 48, illustrated in FIG. 5, is a second reticle
superimposed over the field of view of the optical scope 44 that
indicates a point of impact of the bullet in light of the
compensation information. In FIG. 5, the user would aim the firearm
to place the compensation over the desired point of impact. The
compensation value 50 is also presented to the user within the
field of view of the optical scope 44 and is depicted in FIG. 6.
Alternatively, the compensation value may be presented to the user
via the display 42. It will be appreciated that the compensation
reticle 48 and the compensation value 50 may take various forms and
be presented to the user in various manners. The compensation
reticle, for example, need not be a set of crosshairs, but may be
another type of reticle, such as a circle-x.
[0062] Use of the telescopic sight 10 has been described as
requiring the user to manually submit various pieces of information
via the user input 20. Alternatively, the ballistic information,
calibration information, and the user preference information may be
stored in a computer file and communicated to the sight 10
electronically via the electronic port 22. For example, a user may
download ballistic information relating to a particular firearm or
a particular type of bullet to a computer and store the information
in a computer file. The user may then add calibration information
and user preference information to the file and save the file to a
storage medium within the computer. The user could then update the
file with new information or communicate the file to the sight 10
at the user's convenience.
[0063] Although the invention has been described with reference to
the preferred embodiments illustrated in the attached drawings, it
is noted that equivalents may be employed and substitutions made
herein without departing from the scope of the invention as recited
in the claims. It will be appreciated, for example, that the
telescopic sight 10 may include switches on the housing 12
dedicated to user preferences, thus eliminating the need to
communicate the preferences via the user input 20 or the electronic
port 22.
[0064] Having thus described the preferred embodiment of the
invention, what is claimed as new and desired to be protected by
Letters Patent includes the following:
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