AU2009201006B2

AU2009201006B2 - Improved "moving red dot" sighting device

Info

Publication number: AU2009201006B2
Application number: AU2009201006A
Authority: AU
Inventors: Rene Joannes
Original assignee: FN Herstal SA
Current assignee: FN Herstal SA
Priority date: 2006-02-08
Filing date: 2009-03-12
Publication date: 2012-12-20
Anticipated expiration: 2027-01-31
Also published as: KR101606209B1; SG164333A1; KR20100092377A; AU2009201006A1; BE1018470A3; PL2221571T3; ZA200901655B; EP2221571B1; HUE033353T2; EP2221571A1; DK2221571T3; TWI387719B; ES2624528T3; TW201033578A

Abstract

Improved "moving red dot" sighting device. Improved "moving red dot" sighting device, characterized in that it comprises a fixed light source (4) and a reflecting 5 blade (17), whereby the light source (4) produces a collimated light beam (5) which is projected onto the reflecting blade (17) so as to obtain a red dot or reticle which is visible to the shooter thanks to the reflection on the reflecting blade (17), whereby the beam (5) is 10 projected onto the reflecting blade (17) by means of a rotating mirror (9) whose inclination angle (B) in relation to the light beam (5) can be adjusted. Figure 1.

Description

Australian Patents Act 1990 - Regulation 3.2 ORIGINAL COMPLETE SPECIFICATION STANDARD PATENT Invention Title: Improved "moving red dot" sighting device The following statement is a full description of this invention, including the best method of performing it known to me: P/00/011 5951 Improved "moving red dot" sighting device. The invention concerns a "moving red dot" sighting device. 5 One of the most frequently used types of sighting devices for firing arms applies what is called the red dot technique, which consists in projecting, through the sighting optics, a light point, or more generally a light reticle, in such a manner that the shooter only has to 10 align this point visually with the target so as to fire precisely without any parallax error. Traditionally, we talk of a "red dot" to indicate the light reticle used in this type of sighting device. 15 The actual color of the reticle may vary, provided it is visible. Moreover, the red dot is not necessarily a dot. 20 In what follows, the term "red dot" will thus be used in the broad sense to indicate the light reticle, whereby the sighting device can use any visible light source whatsoever and any form of reticle. 25 Applying the so-called red dot technique to the firing of ammunitions that have a non-flat ballistic trajectory, as is the case when firing grenades, requires the realization of a moving red dot whose height must be adjusted as a 30 function of the distance of the target, such that the 2 shooter obtains the correct elevation of his fire arm by aligning the displaced dot with the target. What makes it difficult to realize a sighting device with a 5 moving red dot is that the range and angular resolution required for firing grenades up to several hundred meters require expensive and sizeable devices. The so-called "moving red dot" sights with which have been 10 introduced so far for firing ammunitions with a curved trajectory are usually based on the use of an LCD screen or a series of LEDs placed in the focal plane of a lens, whose moving image is superimposed in the sighting field of the shooter by a system of fixed mirror or prism and a 15 beamsplitter. Given the elevation angle to be covered, for example of more than 30 in the case of a low-velocity grenade, and the required angular resolution, such a system takes up 20 tens of millimeters in width and in height, which is quite bulky. A disadvantage of such a bulky sighting device is that it is not very appropriate to be used on an individual light 25 fire arm. Another disadvantage of such a sighting device is that, when it is placed on the upper rail of a gun, it is usually not compatible with the use of an external scope and it 30 cannot be used when aiming with two eyes open.

PWPDOCS\AGspeficaionsUU463675 FN HERSTAL DIVdoc-I /14/210 -3 Yet another disadvantage is that the existing sighting devices of this type are usually not fully ambidextrous. The invention aims to remedy one or several of the above-mentioned disadvantages and 5 to provide an improved sighting device with a moving red dot which is compact and which can be used on an individual fire arm. The aim is reached according to the invention by an improved "moving red dot" sighting device, characterized in that it comprises a fixed light source and a reflecting means, 10 whereby the light source produces a collimated light beam which is projected onto the reflecting means so as to obtain a red dot or reticle which is visible to the shooter thanks to the reflection on the reflecting means, whereby the beam is projected onto the reflecting means by means of a rotating mirror whose inclination angle in relation to the light beam can be adjusted. 15 In order to aim at a target, the shooter observes the target while searching the right elevation for his fire arm at which the red dot is aligned with the target, which is a sign that the fire arm is situated in the right firing position. 20 The shooter can aim with two eyes open by observing directly the target with the non aiming eye and the red dot projected onto the reflecting means with the aiming eye. However, the reflecting means is preferably a semi-transparent beamsplitter plate, which enables the shooter C \NRPonbl\DCC\L GL\47)K6I)-_ DOC-21/l l /2012 -4 to observe the target as well as the red dot through the beamsplitter with the aiming eye, while the shooter can also aim with two eyes open, whatever he prefers. 5 The sighting device preferably comprises a device to adjust the inclination angle of the rotating mirror in relation to the light beam, which makes it possible to adjust the sighting device by adjusting the angle of the mirror as a function of the distance of the target and the type of 10 ammunition. According to one aspect, the present invention provides a "moving red dot" firearm sighting device, including a single, fixed, quasi punctual light source, a collimator 15 comprising a convergent lens having a focal point, the light source located at the focal point, a reflecting element, and a mirror located between the collimator and the reflecting element, said mirror being rotatable about an inclination adjusting axis, wherein the light source and collimator 20 project a collimated light beam along an optical axis which is projected onto the reflecting element via the rotatable mirror so as to produce a red dot or reticle which is visible to a shooter due to the reflection of the collimated light beam on the reflecting element, and wherein an 25 inclination angle of the optical axis of the light beam projected onto the reflecting element is adjustable by rotation of the mirror about the inclination adjusting axis. For clarity's sake, a few embodiments of an improved "moving 30 red dot" sighting device according to the invention are described hereafter as an example only without being limitative in any way, with reference to the accompanying C \NRPorb\DCCMGLW(.6'"9_1 DOC-2111 V/2012 -4A drawings, in which: figure 1 is a schematic side view of an improved sighting device according to the invention; 5 figure 2 is a section according to line II-II in figure 1; figure 3 represents the sighting device from figure 1, but in a firing position; figure 4 represents a variant of a sighting device 10 according to the invention; figures 5 and 6 represent views in the respective directions of the arrows F5 and F6 in figure 4; figure 6 corresponds to figure 5, but for another position of the fire arm; P.\WPDOCS\AGspeciations\20463675 FN HERSTAL DIV doc- I 1/4121M -5 figures 7 and 8 are two views similar to those in figures 1 and 2, but for a variant of a sighting device according to the invention; figure 9 is a view similar to that in figure 5, but for a sighting device according to figures 7 and 8; 5 figure 10 is another variant of figure 1; figure 11 is a view according to arrow F 11 in figure 10; figures 12 and 13 are figures similar to figure 11; but for targets at a larger distance; figure 14 is a variant of figure 11; 10 figure 15 is a variant showing a prism as the reflecting means. Figures 1 and 2 represent an improved "moving red dot" sighting device I which comprises a case 2 to be mounted on a fire arm 3, whereby the case 2 extends longitudinally, mainly parallel to the axis of the barrel of the fire arm 2. 15 Inside the case 2 is situated a fixed light source 4, producing a collimated light beam 5 whose optical axis X-X' is in this case parallel to the axis of the barrel of the fire arm 3. In the given example, the light source 4 is a collimator composed of a converging lens 6 20 and of a lamp or another luminous source 7 of quasi punctual shape with reduced dimensions, for example in the order of one tenth of a millimeter, situated in the focal point 8 of the lens 6 and producing the red dot.

6 The collimated light beam 5 has a diameter A in the order of 15 to 20 millimeters, which offers the advantage that the cross dimensions of the width and the height of the sighting device 1 are reduced in relation to the known 5 sighting devices. A mirror 9 is placed in the collimated beam 5 at an angle B in relation to the optical axis X-X' of the produced light beam 5. 10 The mirror 9 is mounted in a rotating manner in the case 2 and it is fixed to that end on a transversal shaft 10 mounted in a rotating manner between the side walls 11 of the case 2. 15 One far end 12 of the shaft 10 of the mirror 9 goes through one of the lateral walls 11 of the case 2 and is provided with an adjusting device 13 for the inclination angle B of the rotating mirror 9 in relation to the produced light 20 beam 5, for example in the form of a turning knob with which the shooter can position the mirror 9 as a function of the distance of the target. The above-mentioned control button 14 will be provided with 25 a scale 15 to that end, representing the distance of the target. In order to make the adjustment more precise, one can add a mechanical demultiplication to the device, such that a 30 rotation of the button 14 results in a smaller rotation of the mirror 9.

P \WPDOCS\AG2008\Spec.cations\2463675 FN HERSTAL DIV do-3/10/2009 -7 Different adjusting buttons comprising scales that are appropriate to different types of ammunition can be realized so as to take the ballistic characteristics thereof into account. The light beam 5 is projected through a window 16 in the case 2 onto a reflecting means 5 17 so as to produce a red dot or reticle, visible to the shooter in the reflecting means 17 which is mounted on a far end 18 of the case 2. In one embodiment (see figs I to 14) the reflecting means is a semi-transparent beam splitter plate (17A) at a fixed angle C of for example 450, in relation to the optical axis X-X' of the produced light beam 5. 10 In one example, the reflecting meansl7 is mounted on the case 2 by means of a rotary hinge 19 which makes it possible to flip down the reflecting blade 17 on the case 2 of the sighting device I when the latter is not operational, such that the whole becomes more compact. 15 Another embodiment (see fig 15) has the reflecting means as a prism 35. In this embodiment the light beam projected onto the prism is deviated upon entering and exiting the prism due to the refraction of light at the air to prism interface 36. Between entering and exiting the prism, the light beam 5 is at least partially internally reflected by a reflecting surface. The reflecting surface is at a fixed angle C, for example 45', in relation 20 to the optical axis X-X' of the produced light beam 5. The deviation of light at the air-prism interface allows for the prism to protrude a distance H from the case 2 that is advantageously less than that of the embodiment where a beam splitter plate is used as the reflecting means. The use of prism therefore provides a more 25 compact sighting device. The use and working of the sighting device I are as follows. When in rest, i.e. when aiming along the axis of the fire arm 3 with an elevation E that is 30 zero, as represented in figure 1, the initial angle B of the mirror 9 is preferably 45'. The angle D is at that time 0".

P\WPDOCS\AG Tspe cicns\2<M63 FNHERSTAL DIV doc-I I/4/2WS -8 The shooter 18 estimates the distance of the target and sets the appropriate inclination B of the mirror 9 by means of the graded control button 14. 5 The light beam 5 is projected onto the reflecting means 17 and is reflected towards the shooter so as to produce a red dot or reticle that the shooter can observe to infinity when the eye of the shooter is situated in the light beam 5 reflected by the reflecting means 17. As the mirror 9 turns, the deviation of the angle D of the beam amounts to two times 10 that of the angle B of the mirror 9. In other words, when the mirror 9 turns for example 150 in relation to the position of rest of 450, the angle D increases from 0' to 300. The inclination B of the mirror, which is a function of the distance of the target, thus determines the angle D at which the red dot can be seen by the shooter, and thus the 15 elevation angle E that is provided to the fire arm 3, as represented in figure 3, when the shooter aligns the red dot or the reticle with the target 21 which, in the case where the reflecting means 17 is a semi-transparent beamsplitter, is visible through said reflecting means 17. 20 If the reflecting means is not semi-transparent, the shooter will have to aim with both eyes open in order to observe the target with one eye and the red dot with the other. Also, it the back of the semi-transparent reflecting means is dirty and cannot be aimed through, the shooter can always aim with both eyes open. 25 An advantage of the sighting device I according to the invention is that, since quasi punctual luminous source 7 is always situated in the focal point 8 of the lens 6 of the collimator, geometrical aberrations are minimized, and the lens 6 may have a small opening and thus a relatively small diameter and focal distance. 30 The cross dimensions of the sighting device 1, determined by the diameter A of the P \WPDOCS\AGsccificanons\2)(461675 FN HERSTAL DIV doc-I I1/4/2(Xn1 -.9 collimated beam, may thus be small. In another embodiment of the sighting device 1, the adjusting device 13 for positioning the mirror 9 consists of a motor controlled by a ballistic calculator, not represented in 5 the figures, for an automatic adjustment. This calculator, when the distance of the target 21 is transmitted thereto, calculates the angle B to provide to the mirror 9 and activates the positioning motor. 10 The calculator can perform the ballistic calculation to determine the elevation angle E, taking into account the properties of the ammunitions that are being fired. Moreover, the calculator can be combined with a range finder that automatically measures the distance of the target 21 when it is activated by the shooter. 15 The sighting device I as represented is disadvantageous in that the collimator, and thus the collimated beam, has a small diameter, which has for a result that it may be difficult for the shooter to find the angle E which guides the eye 20 into the beam 5, in other words to find the red dot. 20 To remedy this problem, the sighting device 1 can be adapted in the following manner. A first adaptation consists in placing a fore-sight 22 in the point of convergence 23 of the axes of the reflected beams on the reflecting means 17, as indicated in figure 4. 25 When the inclination angle B of the mirror 9 changes, the axis 24 of the light beam reflected on the reflecting means 17 will still go through said point of convergence 23, irrespective of the inclination B of the mirror. 30 The point of convergence 23 actually corresponds to the symmetrical position of the axis of rotation 10 in relation to the reflecting means.

P:\WPDOC\AGpcifitions 463675 FN RERSTAL DIV doc.) I/4/flX)B - 10 A second adaptation is illustrated by means of figure 5 and consists in providing a narrow reflecting means 17, placed in a matt, diffusing frame with two lateral strips 25', in such a manner that the incident part of the light beam on the reflecting means 17 which overflows 5 the reflecting means 17 will be diffused by the frame 25 and will appear as a reference 26 in the form of a red spot that can be 11 seen by the shooter, irrespective of the position of the latter's eye 20. Thanks to both adaptations, the shooter will only have to 5 align the reference formed by the spot 26 with the fore sight 22 to find the red dot or reticle, which enables him to aim at the target 21 without any parallax or azimuth errors occurring, as represented in figure 6 in the case of a semi-transparent beamsplitter. Figures 7 and 8 show a variant of a sighting device 1 according to the invention, in which the point of reference 26 is made brighter by concentrating or condensing the lateral edges of the collimated beam S in the frame 25, for 15 example by making the beam 5 go through two cylindrical lenses 27 positioned on either side of the optical axis X X' of the beam 5, or through any other optical device. By concentrating lateral edges of the produced beam, the 20 point of reference 26 is also made narrower, as illustrated in figure 9, which makes it easier to align it with the fore-sight 22. An alternative solution to concentrate the luminous point 25 of reference 26 is provided by the beam of a laser diode or laser pointer, situated in the same horizontal plane as the luminous source 7 of the red dot, and projected parallel to the optical axis X-X' of the collimator onto the frame of diffusion 25 of the sighting device 1. 30 12 This laser beam can be laterally expanded by an appropriate optical device, so as to form a linear spot or a line which constitutes the luminous reference (26). 5 This alternative is interesting in that the size of the reference 26 stays constant, irrespective of the angle of the mirror 9. Figure 10 represents another variant in which the luminous 10 source 7 of the collimator for producing the red dot or reticle consists of a LED 28 with an appropriate intensity and emission angle, placed behind a mask 29 situated in the focal point 8 of the collimator and in which is formed a circular hole 30 or a hole of any other shape at the 15 optical axis X-X'. This variant makes it possible to realize a luminous source 7 with limited dimensions, which is important in view of the precision of the sighting device 1. 20 Indeed, the angle at which the red dot is projected to infinity and thus its apparent size at a given distance, is in proportion to the size of the luminous source 7 of the collimator and inversely proportional to the focal distance 25 of the latter. For example, in the case of a focal length of 40 mm, a circular luminous source 7 having a radius of 0.5 mm will produce a red dot whose apparent radius is: 30 0.5 x 100 / 40 = 1.25 m at 100 m 0.5 x 300 / 40 = 3.75 m at 300 m 13 Thus, the luminous source 7 must have limited dimensions, in order to provide a red dot with an apparent size which is compatible with the aimed target 21, which means that it 5 must have a radius in the range of 0.1 to 0.2 mm. It should be noted, however, that the dimensions of the luminous source 7 determine the quantity of light gathered by the lens 6 of the collimator, and consequently, the 10 brightness of the luminous points of reference 26 projected onto the diffusing frame 25 of the sighting device 1. Hence, there is a conflict between the requirement of a small red dot and the necessity to obtain references 26 that are sufficiently bright for the preliminary alignment 15 of the aiming axis with the fore-sight 22. In order to reconcile both restrictions, it is advantageous to use, instead of a circular dot to be positioned on the target, a mark or reticle with a larger surface, inside of 20 which the shooter has to visually place the target 21. It may be formed, for example, of two pointers 31 framing the target 21, as illustrated in figures 11 to 12, which figures represent the perception of the reticle and the target 21 by a shooter who is aiming at a target at 25 different distances, for example at 100, 200 and 300 meters respectively. According to yet another variant, as represented in figure 14, also additional scales or marks 32, 33 can be included 30 in the reticle, which enable the shooter to shift his firing axis so as to correct, when firing at long range, 14 the trajectory error due to the rotation of the ammunition around its axis, better known as the Magnus effect. Figure 14 shows an example of a reticle which comprises an 5 additional scale 33 on a horizontal axis 34, to be used when firing over more than 300 meters in the case of low velocity grenades. Instead of providing an additional scale 33 on the fixed 10 reticle, one can also make sure that a simple reticle such as the one of figure 11 is automatically moved in the lateral direction by a device controlled by the ballistic calculator as a function of the type of ammunition used and the distance of the target, such that the deviation of the 15 trajectory of the ammunition due to the Magnus effect is corrected. The position of the reticle can also be moved perpendicularly to the optical axis by an adjusting device, 20 so as to harmonize the sighting device with the launcher. The use of a reticle with a marked horizontal axis 34 offers an additional advantage in that it forms a line of reference that helps the shooter, when aiming, to maintain 25 his fire arm in a strictly vertical position, thus avoiding what are called "cant" errors which occur when the fire arm is laterally inclined. This effect can be multiplied by making use of a mask which 30 is free to pivot round the optical axis X-X' of the collimator, and which is ballasted with an unbalanced mass, 15 which has for an effect that the reticle is kept at level, "in the manner of a plumb-line". The inclination of the reticle in relation to the vertical 5 axis of the frame of diffusion will make a possible error in the vertical position of the fire arm more noticeable to the shooter while aiming. Moreover, if the sighting device 1 is controlled by a 10 ballistic calculator equipped with an inclinometer which instantly measures the vertical deflection of the fire arm, this calculator may provoke, by means of an appropriate mechanism or device, an inclination of the reticle or of a horizontal line of reference round the optical axis of the 15 collimator in proportion to the vertical deflection of the fire arm, possibly amplified with regard to the latter, such that it will be better perceived by the shooter while aiming. 20 The masks 29 which correspond to these various reticles can be realized by means of photolithography, which makes it possible to obtain dimensions in the order of one tenth of a millimeter, with resolutions of one hundredth of a millimeter. 25 It is clear that the reticles must not necessarily be red, but that reticles having another color, for example yellow green, may also give a good contrast. 30 A non-monochromatic light source or "white" light can also be used.

P \WPDOCS\AGspecificanos\2I463675 FN HERSTAL DIV doc-I /4/2WX - 16 It is also clear that the case 2 may have any shape whatsoever. Instead of mounting the reflecting means 17 in a matt frame 25, the frame 25 can also be replaced by one or two lateral diffusion strips 25'. 5 It is clear that the invention is by no means limited to the examples described above, but that many modifications can be made to the above-described "moving red dot" sighting devices while still remaining within the scope of the invention as defined in the following claims. 10 The reference in this specification to any prior publication (or information derived from it), or to any matter which is known, is not, and should not be taken as, an acknowledgement or admission or any form of suggestion that that prior publication (or information derived from it) or known matter forms part of the common general 15 knowledge in the field of endeavour to which this specification relates. Throughout this specification and the claims which follow, unless the context requires otherwise, the word "comprise", and variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated integer or step or group of 20 integers or steps but not the exclusion of any other integer or step or group of integers or steps. The reference numerals in the following claims do not in any way limit the scope of the respective claims.

Claims

1. A "moving red dot" firearm sighting device, including a single, fixed, quasi punctual light source, a collimator 5 comprising a convergent lens having a focal point, the light source located at the focal point, a reflecting element, and a mirror located between the collimator and the reflecting element, said mirror being rotatable about an inclination adjusting axis, wherein the light source and collimator 10 project a collimated light beam along an optical axis which is projected onto the reflecting element via the rotatable mirror so as to produce a red dot or reticle which is visible to a shooter due to the reflection of the collimated light beam on the reflecting element, and wherein an 15 inclination angle of the optical axis of the light beam projected onto the reflecting element is adjustable by rotation of the mirror about the inclination adjusting axis.

2. The sighting device according to claim 1, wherein the 20 reflecting element is a semi-transparent beamsplitter.

3. The sighting device according to claim 1, wherein the sighting device is intended for use with a firearm shooting a given type of ammunition along a ballistic trajectory, 25 comprising an adjusting device arranged to enable adjustment of the inclination angle of the mirror as a function of the distance of a target and of the given type of ammunition.

4. The sighting device according to claim 3, wherein the 30 adjusting device includes a scale representing the distance of the target. C \NRPonblDCC\LGLW760x69_ I DOC-21/ 1/2012 - 18

5. The sighting device according to claim 4, wherein the adjusting device includes several scales for different given types of ammunition. 5

6. The sighting device according to claim 3, wherein the adjusting device comprises a motor arranged to adjust the inclination angle of the mirror and a ballistic calculator controlling said motor enabling calculating and setting a required inclination angle of the mirror as a function of 10 the distance of the target and/or of the given type of ammunition used.

7. The sighting device according to claim 6, wherein the ballistic calculator includes a range finder which is 15 arranged to automatically communicate a distance of the target to the range finder when a calculation of the inclination angle is requested by a shooter.

8. The sighting device according to claim 1, wherein the 20 diameter of the collimated light beam is about 15 mm or less.

9. The sighting device according to claim 1, said light source including a LED disposed behind a mask located at the 25 focal point of the collimator lens, said mask having a hole located along the optical axis through which light from the LED projects to the collimator lens.

10. The sighting device according to claim 1, including a 30 fore-sight placed at a point of convergence of axes of beams reflected on the reflecting element. C \NRPortbI\DCC\LGL\4760)69 I DOC-21II/ 12012 - 19

11. The sighting device according to claim 1, including a lateral diffusion strip at one or both sides of the reflecting element onto which a luminous reference is projected parallel to the optical axis of the collimated 5 beam.

12. The sighting device according to claim 11, wherein the luminous reference is formed by the collimated beam itself. 10

13. The sighting device according to claim 11, wherein the luminous reference is formed by condensing the exterior parts of the collimated beam by means of an optical device.

14. The sighting device according to claim 11, wherein the 15 luminous reference is formed by a beam of a laser pointer having an axis extending mainly parallel to the optical axis of the collimated beam.

15. The sighting device according to claim 14, wherein the 20 beam of the laser pointer is laterally expanded by an appropriate optical device so as to form a line which defines the luminous reference.

16. The sighting device according to claim 3, wherein the 25 reticle includes several marks which correspond, each for a determined distance of the target, to the required sighting correction so as to take into account the deviation of the trajectory of the given type of ammunition due to Magnus effect. 30 C WRPortbIWlCCU.GLW7N6 9_1 DOC-21/1 1/2012 -20

17. The sighting device according to claim 3, wherein the position of the reticle is automatically movable in a lateral direction by a device controlled by the ballistic calculator as a function of the given type of ammunition 5 used and the distance of the target, so as to correct the deviation of the trajectory of the ammunition due to Magnus effect.

18. The sighting device according to claim 6, wherein the 10 reticle includes at least a horizontal reference and the ballistic calculator includes an inclinometer arranged to measure a vertical deflection of the firearm, wherein the calculator is arranged to adjust the inclination of the reference or of the reticle relative to the optical axis in 15 proportion to the vertical deflection of the firearm, such that the reference or reticle will be better perceived by a shooter of the firearm while aiming.

19. The sighting device according to claim 1, wherein the 20 sighting device includes a case supporting the light source, collimator, mirror and reflecting element, the reflecting element extending upwardly relative to the case during use, and wherein the reflecting element is collapsible downwardly relative to the case to reduce of the height of the sighting 25 device.

20. A "moving red dot" firearm sighting device, substantially as herein described with reference to the accompanying figures. 30