Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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TITLE OF THE INVENTION
SPLATTER INDICATOR SIGHT FOR FIREARMS
FIELD OF THE INVENTION
The present invention relates to a splatter indicator sight for firearms. More
specifically, the present invention is concerned with an indicator device for
processing data regarding variables affecting the bullet trajectory and
creating
a visual map of all of the probable hit zones after the user has aimed the
firearm at the target, thereby allowing the user to evaluate the risk of
hitting the
wrong target before shooting.
BACKGROUND OF THE INVENTION
Firearms, such as handguns (single-shot pistols, revolvers, and semi-automatic
pistols), long guns (rifles, carbines or shotguns) and machine guns or the
like
are aimed at their targets with greater accuracy by using sights. Many sights
can be mounted onto firearms, for example, telescopic sights (or scopes), iron
sights, red dot sights, and laser sights.
Despite these existing sighting systems, aiming errors still occur. Those
errors
depend to some degree on the skill of shooter, but also the quality and
caliber
of the firearm and other exterior conditions such as the range to the target,
the
movement of the target, the ambient light, and the wind. The aiming error
becomes a considerable issue when the firearm is used by security forces in
civilian zones where there exists a risk of hitting an innocent bystander or
other
friendly by accident.
The prior art reveals processing of data affecting the bullet trajectory in
order to
correct the aim or provide warnings to the user (where data received from
sensors mounted onto the firearm or entered by the user is processed and
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provides for the automatic adjustment of aim, stabilization as well as the
display
of data related to aiming error) these existing aids focus on perfecting the
aim.
Potential for error still exists, however, and a shot fired might fall within
an area
surrounding the point of aim. Therefore, there is a need for a device that
will
clearly and quickly indicate the probable hit zones around the aiming point to
let
the user better decide whether or not to shoot.
SUMMARY OF THE INVENTION
The object of the present invention is to provide firearms with a splatter
indicator sight which will take many important variables affecting the bullet
trajectory into consideration to create a risk zone map of the different zones
which can be hit after the user has aimed the firearm at a target. In
embodiments of the invention, the boundaries of the most probable hit zones
can be quickly indicated to the user by the risk zone map. The risk zone map
is
illustratively created by projecting a laser beam directly on the target.
There is also provided a splatter indicator sight for attachment to a firearm.
The
sight comprises a risk zone map and a laser for displaying at least a portion
of
the risk zone map on a target. The risk zone map defines a first region within
which a projectile issued from the firearm will strike with a first
predetermined
probability.
There is additionally disclosed a method for supporting a decision to fire a
projectile from a firearm pointed at a target. The method comprises providing
a
risk zone map, the risk zone map defining a region within which a projectile
issued from the firearm will strike with a predetermined probability,
providing a
laser for emitting the risk zone map and displaying the risk zone map on the
target.
There is furthermore provided a firearm comprising a barrel arranged along an
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axis and a laser aligned with said axis, said laser emitting a risk zone map.
When displayed on a surface, the risk zone map defines a region within which
a bullet issued from said barrel will strike with a predetermined probability.
Additionally, the splatter indicator sight will allow the user to evaluate the
risk of
hitting an innocent or other friendly instead of the intended target before
shooting and could also be used to provide a visual indication to a target
that
he has been targeted when the luminous risk zone map is projected on him.
Other objects, advantages and features of the present invention will become
more apparent upon reading of the following non-restrictive description of
specific embodiments thereof, given by way of example only with reference to
the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
In the appended drawings:
Figure 1 discloses a laser sight mounted on a firearm and used to project the
risk zone map on the target in accordance with an illustrative embodiment of
the present invention;
Figure 2A discloses a risk zone map projected on a flat surface by the
splatter
indicator sight in accordance with an illustrative embodiment of the present
invention;
Figure 2B discloses the risk zone map of Figure 2A projected on a target;
Figure 2C discloses the risk zone map of Figure 2A projected on a target
located in a crowd of innocents or friendlies;
Figure 3A and Figure 3B disclose a risk zone map in accordance with a first
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alternative embodiment of the present invention;
Figure 4A and Figure 4B disclose a risk zone map in accordance with a second
alternative embodiment of the present invention;
Figure 5A and Figure 5B disclose a risk zone map in accordance with a third
alternative embodiment of the present invention;
Figure 6A and Figure 6B disclose a risk zone map in accordance with a fourth
alternative embodiment of the present invention; and
Figure 7 is a block diagram of the splatter indicator sight components in
accordance with an illustrative embodiment of the present invention.
DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS
The present invention is illustrated in further details by the following non-
limiting
examples.
Referring now to Figure 1, and in accordance with an illustrative embodiment
of
the present invention, a firearm comprising a splatter indicator sight, and
generally referred to using the reference numeral 10, will now be described.
The firearm 10 comprises a splatter indicator sight 12 comprising a laser (not
shown) emitting a laser beam 14 co-aligned with the muzzle 16. The indicator
sight 12 is illustratively mounted within the chamber 18 which also houses the
recoil spring (not shown). Alternatively, the indicator sight 12 could be
positioned on top of a firearm 10 or below the barrel on a dovetail, MIL-STD-
1913 Picatinny rail or similar mount.
Still referring to Figure 1, many aiming errors are directly caused by the
user.
For example, parallax is created when the user moves in relation to the sight
12. Additionally, normal shaking of the hand holding the firearm 10 can be
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amplified when the user finds himself within a stressful situation. Also, when
a
shot is fired, recoil can further amplify the movement of the hand holding the
firearm 10.
5 Referring now to Figure 2A in addition to Figure 1, in an illustrative
embodiment
of the present invention, the laser beam 14 emitted or projected by the
indicator
sight 12 forms a pattern 20, or risk zone map, when projected on a surface
located in front of the firearm 10 and surrounding the point being aimed at
22.
The contour(s) 24 defined by the risk zone map 20 can adopt various shapes
according to the values of the different data taken into account. In the
present
illustrative embodiment the contour(s) 24 are represented by an oval shape
since the aiming error will presumably be greater relative to the upper/lower
axis A of the firearm 10. The risk zone map 20 defines the limits of the most
probable hit zones (in other words, a predetermined level of probability that
a
projectile issued from the firearm will strike within a defined region)
according to
calculations which will be described in more detail hereinbelow.
Referring now to Figure 2B, when the firearm 10 is aimed at a target 26, the
risk zone map 20 is projected onto the target 26 surrounding the point being
aimed at 22. In the context of Figure 2B, the risk zone map 20 indicates that
there is less risk of shooting an innocent or other friendly as only the
target 26
is found within the risk zone map 20.
On the other hand, and referring now to Figure 2C, the risk of hitting an
innocent or other friendly by accident is increased as, although the point
being
aimed at 22 falls on a target 26, innocents or other friendlies as in 28 also
fall
within the risk zone map 20.
Referring now to Figure 3A and Figure 3B, in a first alternative illustrative
embodiment the risk zone map 20 is characterized by a central point 30
surrounded by a circle 32 indicating a region within which the risk of
accidentally shooting an innocent is high. In this regard, and as will now be
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understood by a person of ordinary skill in the art, the circle 32 is
projected as a
cone such that the diameter of the circle 32 increases with an increase in
distance between the indicator sight (reference 12 in Figure 1) and the target
26.
Referring now to Figure 4A and Figure 4B, in a second alternative illustrative
embodiment the risk zone map 20 is characterized by a target-like series of
concentric circles as in 34. The risk of accidentally hitting an innocent
decreases with an increase in the relative diameter of a given circle as in
34.
Each of the increasing circles as in 34, for example, could represent an
incremental increase of the Minute of Arc (MOA).
Referring now to Figure 5A and Figure 5B, in a third alternative illustrative
embodiment the risk zone map 20 is characterized by a cross-hair comprising a
pair of crossing elements as in 36 arranged at right angles to one another.
Referring now to Figure 6A and Figure 6B, in a fourth alternative illustrative
embodiment the risk zone map 20 is characterized by a cross-hair reticule
comprising a pair of crossing elements as in 36 arranged at right angles to
one
another and with the addition of cross-hatch as in 38 on each of the pair of
crossing elements as in 36. Illustratively, and similar to that as described
above
in regards to Figure 4A and Figure 4B, the relative distance of the cross-
hatch
as in 38 from the point of crossing 40 of the crossing elements as in 36 could
represent a relative increase or decrease in the MOA.
A variety of approaches may be used for generating and projecting the risk
zone map 20 on a target 26 using a laser 14.
For example, in a first illustrative embodiment of same, the actual lasing
action
can be used to set the desired beam divergence. In other configurations a
laser
will generate a beam with a given divergence (typically on the order of 0.5-10
mrad) and then the desired spread angle will be set with external collimating
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optics. Lasing action in the laser cavity can be controlled to some degree
with
the configuration of the laser cavity, adjusting parameters such as mirror
curvature, spacing, selection of location of the beam waist, inter-cavity
apertures, bore diameter, etc.. Specifically, in semiconductor (diode) lasers,
an
apparent point source can be generated by ion milling (or similar) a convex
high reflector mirror into the diode laser's cavity.
In a second illustrative embodiment divergence of the laser can be introduced
using a collimating telescope. In this regard, a single, solid cone of light
is
generated from a single laser source and a Galilean or Keplerian telescope is
placed in the beam to collimate, or decollimate, the emitted laser beam. These
telescopes may use two or more optics. Adjustment between the separation
distance of these two optics in either telescope (focus) can provide for a
change in the divergence angle of the emitted beams.
In the above two embodiments, it may also be desirable to utilize a beam
diffuser, of which a number of known types exist, to generate a more uniform
beam profile (top hat), prior to adjusting the beam divergence. This provides
for
much more uniform laser spot illumination assisting visibility and more
carefully
defining the edge of the desired spot.
In a third illustrative embodiment a diffuser may be used in conjunction with
the
laser 14 to generate a cone angle. Rather than using a telescope to change the
natural divergence of the generated beam, a diffuser may be designed and
used to generate a cone of light of the desired angle. Although "opal glass"
or
rough surface glass diffusers are common and could potentially be used, a
Holographic Optical Element (HOE) diffuser is preferable.
In a fourth illustrative embodiment, HOEs are designed and used to shape light
to precise shapes and patterns as they provide a low cost and optically
efficient
means to make complex projection patterns. In particular, both binary and
diffractive optics, which are closely related, are included here. Employment
of a
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custom pattern/angle HOE or other phase mask may be used for some
implementations.
In a fifth illustrative embodiment, rear illumination and subsequent
collimation of
a window or mask pattern can be used. This would typically be a glass or
plastic window with a pattern applied opaquely, such as chrome on glass, a
chemically etched or laser cut stainless steel stencil or similar. A lens or
lens
system is used downstream of the window to gather light and collimate to the
desired angle of divergence. The pattern disc may be somewhat diffuse in
nature.
In a sixth illustrative embodiment, the risk zone map 20 is the result of a
vector
scan which traces the desired image or pattern using a rapidly moving spot.
Scanning of simple patterns such as circles can be achieved with a spinning
off
axis mirror, wedge cut refractive optic or the like. Complex patterns can be
achieve by spinning HOE scanner optics, or more conventionally with XY
galvanometer scanners. The same result might also be achieved with MEMs
scanning devices such a DLPs, GLVs and related technologies.
In a seventh illustrative embodiment, areas can be delineated with the use of
multiple static spots rather than full vector or filled patterns. This is
discussed
more below as an additional claim as a way to increase the image brightness.
The visibility of the laser light on a target is determined by the energy
density at
the target location reflected back to the viewer's location. Even low power
laser
light may be quite visible when viewed at a significant distance if it remains
in a
small spot. However, if the angle of divergence is significant, and/or the
spot is
large, as it may be at long distances, practical and/or safe levels of laser
light
may not be as visible as would be desirable when the spot spreads to a large
diameter. In order to address this problem, one solution is to delineate the
diameter of an imaginary circle or box with two or more individual low
divergence (small diameter) beams to maintain brightness with low levels of
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power. These multiple beams could be generated with multiple lasers, or with
discrete optics or HOE, diffractive or binary optics to generate multiple
beams
from a single input beam (single laser).
As discussed above, the effect of the offset and/or parallax between the path
of
the bullet and the path of the laser light can affect can vary from moderate
to
insignificant depending on the distance from the firearm to the target.
Indeed, if
the laser is simply a cone of light being emitted from a device mounted, for
example, to the top of the barrel of the firearm, for example like a riffle
scope,
there is offset between the origin of the path of the laser light and the path
of
the projectile (bullet). If the natural fall of the bullet is not taken into
account,
both the laser light and the bullet will travel a straight path, separated by
1-2
inches. If the target is at a significant distance, this offset is likely
insignificant
due to the inherent spread pattern or error in the bullets flight path.
However, if
the target is close to the weapon there will be offset, or alternately
parallax.
In order to address this problem, the end of the barrel can be fitted with a
mechanism such that the beam or beams are emitted uniformly around or
directly down the axis of the barrel. This can be achieved in a couple of
different manners.
Firstly, a reflector can be placed at some angle at the end of the barrel
(typically 45 degrees). This reflective optic, such as a flat mirror will have
a hole
in the center to allow the passage of the projectile, while still allowing
reflection
of the light in a path concentric with the projectile.
Secondly, an optic can be used to collimate the light around the path of the
projectile which is not a planar (flat) mirror, but may be a concave optic
such as
an off axis parabola. These approaches would also have a hole in the center,
through which the projectile can pass.
Thirdly, a diffractive, holographic, binary or phase grating can be used to
shape
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the light into the desired collimated pattern without a concave shape/curved
surface.
Depending on the use environment, front surface mirrors may be desired.
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Alternatively, one beam could be emitted above or below the barrel and one to
the right or left of the barrel. In this way, the user imagines the
intersection of a
horizontal and vertical line as the center of emission, and then uses the
location
of the two beam spots to construct a square or circle which represents the
risk
10 zone map.
Also, for special single use conditions, a pellicle beam splitter can be
placed
directly over the end of the barrel at some angle, typically 45 degrees. The
pellicle beams splitter is made from a very thin optically reflective layer of
cellulous, mylar or similar material. The thickness of this material can be
just a
few microns such that it is an extremely thin weak film which will be pierced
with milligrams of force and thus not affect the projectile, thereby allowing
the
emitted laser light to be aligned precisely with the bore of the weapon with
zero
offset or parallax. It can be noted that the pellicle beam splitter is
effectively a
tympanic membrane and will respond to acoustic vibrations (sound), this may
limit its use in some situations. Alternately, a solid but very thin glass
beam
splitter could be used and shatter upon use.
Referring now to Figure 7, an illustrative embodiment of the electronics 42
used
to drive the laser beam 14 will now be described. The electronics 42 comprises
a CPU 44 which receives data from one or more sensors as in 46, processes
the data according to a program (not shown) stored in a Read Only Memory
(ROM) 48 and/or Random Access Memory (RAM) 50 as well as user inputs
(also now shown) received via a user interface (I/O) 52 and illustratively
stored
in the RAM 50. In this regard the user interface 52 could be provided by one
of
a number of means including user selectable buttons (not shown), infrared,
USB or the like. The CPU 44 provides control signals to a laser driver 54
which
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drives the laser beam 14 to project the risk zone map (reference 20 in Figure
1). Additionally, a source of power 56, such as a battery or the like, is
provided
to power the electronics 42 and the laser beam 14. Referring back to Figure 1
in addition to Figure 7, control of power supplied by the source of power 56
to
the electronics 42 and the laser beam 14 can be controlled, for example, by
slightly depressing the trigger 58 or through provision of a switch (not
shown) or
the like.
Still referring to Figure 7, the sensors as in 46 may comprise one or more of
a
variety commercially-available electronic sensors such as accelerometers or
the like. Listed below are examples of data that can be taken into
consideration
for calculating the risk zone map 20:
= target data: distance, height, speed;
= meteorological data: wind direction and speed, temperature,
pressure, humidity;
= spatial data: movement of firearm (banking, rotation, lateral, up-
down);
= ammunition data: cartridge info, bullet weight, ballistic coefficient;
= weapon data: weapon length (farthest distance to which an
averagely-trained soldier can hit a man-sized target).
Still referring to Figure 7, one parameter of interest which can be used as a
basis for determining the proportions of the risk zone map 20 is the maximum
effect range. In this regard, firearm manufacturers typically determine for
each
firearm a distance at which an averagely trained soldier using the particular
firearm is able to hit a man-sized target (typically 46cm x 91cm or 18" x 36).
Some typical values for some known firearms are provided below:
= M9 9mm Glock / Berrette 50m
= M4 5.56mm Carbine 200m
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Another parameter of interest (discussed briefly above) and which may also be
used to determine the proportions of the risk zone map 20 is the MOA. MOA is
a unit of angular measurement equal to one sixtieth (1/60) of one degree. One
(1) MOA is one inch at 100 yards (91 meters). MOA is often used when
characterizing the accuracy of rifles and indicates that, under ideal
conditions,
the firearm in question is capable of repeatedly producing a group of shots
whose center points (center-to-center) fit within a circle, the diameter of
which
can be subtended by that amount of arc.
Although the present invention has been described hereinabove by way of
specific embodiments thereof, it can be modified, without departing from the
spirit and nature of the subject invention as defined in the appended claims.
