HK1144595A - Improved sight with mobile red dot - Google Patents

Description

The invention relates to an improved mobile red dot sight.

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It is a sight intended to be mounted on a weapon for firing ammunition with an unstressed ballistic trajectory, for example, grenade firing, which requires firing with a certain elevation angle to the weapon, depending on the distance to the target.

In this type of sight, a point or a light reticle is projected to infinity with a pointing angle such that, relative to the weapon, the shooter obtains the correct elevation of his weapon by aligning this point or reticle with the target when aiming.

The red-point moving sight according to document EP 1.818.645 comprises a fixed light source; a rotating mirror; a flat reflecting blade or more generally a reflecting surface, the light source generating a collimated light beam which is projected onto the reflecting surface to make a red or reticulated point visible to the shooter by reflection on the reflecting surface, the beam being projected onto the reflecting surface by means of the rotating mirror whose angle of inclination relative to the light beam generated is adjustable to adjust the angle of view under which the red point is observed by the shooter in a reference direction of the target and within a minimum range of angles between a target and a target.

The sight thus made allows the shooter to adjust the angle of the rotating mirror according to the type of ammunition used and the distance to the target, which can be measured or estimated by the shooter.

The angle of the rotating mirror is set, for example, by a control knob with a calibrated scale adjustment according to the distance to the target or by an actuator controlled by a calculation system to calculate the angle to be given to the rotating mirror according to the distance and possibly according to the type of ammunition chosen.

Once the angle of the rotating mirror is established, the shooter simply observes the target and looks for the elevation of his weapon for which the red dot is aligned on the target, indicating that the weapon is in the correct firing position.

A disadvantage of this type of viewfinder is that the maximum viewing angle is limited by the length of the reflecting surface in the plane of the light beam, as the longer the reflecting surface, the greater the angle of view to be achieved.

However, to use the maximum range of a ballistic projectile, it is necessary to be able to fire at angles of 40° or more, which requires a relatively long reflective surface, which adversely affects the size of the sight.

The purpose of the invention is to avoid the abovementioned drawbacks and to make it possible to make a movable red dot sight with a reflecting or semi-reflecting mirror of a reduced size which allows angles of vision close to or greater than 40°.

This purpose is achieved according to the invention by a red-point moving sight of the above type, which comprises at least one optical element located in the path of the light beam between the rotating mirror and the eye of the shooter so that the light beam is deflected on its path between the rotating mirror and the eye of the shooter, the shape of this element being such that the deflections it causes on the light beam have the effect of reducing the path travelled by it between the rotating mirror and the reflecting surface for the same angle of view, at least in part of the above range of viewing angles and preferably at least in the region of the viewing angles close to the maximum angle of view.

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Because of this effect, angles of view of the order of 40° or more can be achieved with a smaller reflective surface length relative to a viewfinder without this optical element of the invention.

Such a sight is therefore less cumbersome than sight of the same type with a flat reflective blade and without these additional optical means.

For clarity, some examples of the construction of a red dot sight improved according to the invention are described below for illustrative and non-restrictive purposes, referring to the attached drawings in which: Figure 1 is a schematic side view of a viewfinder according to the state of the art, shown in a resting position;Figure 2 is a cut according to line II-II of Figure 1;Figure 3 represents the viewfinder of Figure 1, but for a different setting of the view angle;Figure 3B represents the viewfinder of Figure 3A but in a firing position;Figure 4 represents the path taken by the light beam in the viewfinder of Figure 1, for different view angles;Figures 5 to 11 represent views similar to those of Figure 4, but for other implementations of a viewfinder according to the invention.

Figures 1 and 2 show a viewfinder as described in EP 1.818.645.

It is a mobile red dot sight 1 that includes a case 2 designed to be mounted on a weapon 3, the case 2 extending longitudinally essentially parallel to the axis of the gun 3.

Inside the housing 2 is a fixed light source 4 generating a collimated light beam 5 with a 5' central radius whose optical axis X-X' is in this case parallel to the axis of the gun 3.

In the example shown, the light source 4 is a focus composed of a convergent lens 6 and a lamp or other near-point light source 7 of reduced dimensions, e.g. of the order of one tenth of a millimeter, located at the focus 8 of the lens 6 and generating the red dot.

The collimated beam 5 has a diameter A of 15 to 20 mm, which makes it advantageous to have transverse dimensions of width and height of the viewfinder 1 reduced compared to other viewfinders.

A mirror 9 is placed in collimated beam 5 at an angle B to the X-X' optical axis of the light beam 5 generated.

The mirror 9 is mounted in a rotating manner in box 2 and is fixed for this purpose on a transverse axis 10 mounted in a rotating manner between the side walls 11 of box 2.

A 12 end of the 10 axis of mirror 9 passes through one of the 11 side walls of the 2 case and carries a device 13 to adjust the angle of inclination B of the rotary mirror 9 in relation to the light beam generated by 5, e.g. in the form of a rotary adjustment button, possibly equipped with a multiplication mechanism, which will allow the shooter to position mirror 9 according to the distance from the target 14.

The control knob may be equipped with a grading 15 representing the distance from the target 14 or different gradings for different types of ammunition, taking into account the ballistic characteristics of the ammunition.

The light beam 5 is projected through an aperture 16 in box 2 onto a reflecting surface 17 in the form of a reflecting blade 17 to make a red dot or reticle visible to the shooter on the surface 17 of the reflecting blade which is mounted on a end 18 of the box 2 at a fixed angle C, e.g. 45°, to the optical axis X-X' of the light beam generated 5.

The use of sight 1 is as follows.

At rest, i.e. when aiming at the axis of the weapon 3 with an elevation E which is zero, so with the weapon in the horizontal position as shown in Figure 1, the angle of rest B of mirror 9 is for example 45°. The aiming angle D is at this point 0°, this angle being the angle between the light beam 5 reflected on the reflecting surface 17 and the optical axis X-X' or axis of the weapon 3.

Shooter 19 estimates the distance from target 14 and adjusts the appropriate tilt B of mirror 9 using the distance-graduated adjustment device 13.

The light beam 5 is projected onto the reflecting surface 17 and is reflected as shown in Figure 3 towards the shooter 19 to materialize a red or reticulated point which the shooter 19 can observe indefinitely when the shooter's eye is in the light beam 5 reflected by the reflecting surface 17.

When mirror 9 rotates as shown in Figure 3A, the deviation of the beam angle D is twice that of mirror 9 angle B. In other words, if mirror 9 rotates, for example, 15° from the resting position of 45°, the angle D goes from 0° to 30°.

The tilt B of mirror 9, as a function of the distance from target 14, therefore determines the angle D from which the red dot is seen by the shooter 19, and therefore the elevation angle E that is given to weapon 3, as shown in Figure 3B, when the shooter aligns the red dot or reticle on target 14 that is seen next to or through the reflective surface 17.

Figure 4 shows the paths of the 5' central radius of the collimated beam 5 for four different values of the angle B of the rotating mirror 9 and therefore for four corresponding values of the angle of view D, in particular for angles of view D of 0°, 10°, 20°, 30° and 38° respectively as shown in the figure.

The point I of incidence of the 5' centre beam of the 5' light beam on the reflecting surface 17 is at point I0 for a viewing angle D of 0°, while the point I of incidence for a viewing angle D of 38° is at point I38 near the distal end of the 17' reflecting surface.

The length L of the reflecting surface 17 in the plane of the light beam 5 is therefore determined by the distance between the extreme points of incidence I38 and I0 and therefore by the maximum angle of view D to be obtained, which in the case of Figure 4 is close to 40°.

In the case of Figure 4 the L-length of the reflecting surface is relatively large.

The purpose of the invention is to limit the L-length of the reflecting surface 17 without compromising the maximum angle of view D and thus to achieve angles of view D of 40° or more.

This is achieved by introducing between the rotating mirror 9 and the eye of the shooter 19 one or more optical elements 20 of a suitable shape which deflect the rays of the collimated light beam 5 and alter their impact on the reflecting mirror 9 in relation to a situation with the same angle of view D but without this optical element 20.

In the case of Figure 5, the optical element 20 is made as a transparent element 21 of rectangular section in the plane of the beam and located between the rotating mirror 9 and the reflecting surface 17 and positioned parallel to the optical axis X-X'.

The transparent optical element 21 is determined in such a way that the refractions it causes on the rays of beam 5 decrease the OI path length of the latter between the rotating mirror 9 and the point of impact I on the reflecting surface 17 as can be seen by comparing Figures 4 and 5, respectively without and with optical element 20, and this all the more so since the refractive index of the optical element 20 is high.

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It therefore reduces the L-length of the reflecting surface 17 required to provide the maximum viewing angle.

For the compression effect to allow a considerable reduction in the L-length of the reflecting surface 17, the thickness of the optical element 20 must of course be sufficient.

It should be noted that the rectangular shape of the compression optical element 20 shown in Figure 5 is only one example and that other shapes may be used, as shown in Figure 6, which represents a compression optical element 22 with a triangular section.

It is shown in Figure 5 that the refraction produced on hypotenuse 23 changes the relationship between the angle B of the rotating mirror 9 and the angle of view obtained D and that the mirror adjustment law must therefore be adapted according to the angle of view to be obtained, i.e. according to the distance from the target, and also that for weak angles of view the OI path of the beam between the rotating mirror 9 and the reflecting surface 17 is slightly increased, while for large angles the OI path is however reduced, which allows the desired effect to be achieved, i.e. the reduction of the length of the reflecting surface 17 required to provide the maximum viewing angle.

The triangular element 22 in Figure 6 is not a common standard optical component, unlike the rectangular element 21 in Figure 5, but it has the advantage over it of being less bulky, and therefore less heavy, which may be of interest in a light weapon application.

In the examples in Figures 5 and 6, the optical element 20 is placed between the rotating mirror 9 and the reflecting surface. This optical element 20 may also be placed at the exit of the viewfinder 1, i.e. between the reflecting surface 17 and the shooter's eye 19, as shown in Figure 7. Here again, the refractions on beam 8 by the optical element 20 reduce the path OI has travelled between the rotating mirror 9 and the reflecting surface 17, resulting in the desired effect, i.e. reduction of the length L of the reflecting surface required to provide the maximum viewing angle.

In the example in Figure 7 it is shown that the L-length reduction is important, but this advantage is partially lost by the bulk of the optical element 20.

It is of course possible to combine optical compression elements between the rotating mirror 9 and the reflecting surface 17 with optical compression elements between the reflecting surface 17 and the shooter's eye 19.

According to an advantageous embodiment of the invention, the optical element 20 used for the compression of the trajectories of beam 5 is a right isosceles prism 24 whose hypotenuse 25 acts as the reflecting surface 17, as shown in Figure 8.

It should be noted that the prism 24 is located between the rotating mirror 9 and the reflecting surface 17 which is its hypotenuse 25, and between this surface 17 and the eye of the shooter 19. In addition to combining the optical compression element 20 and the reflecting surface 17 into a single component, this configuration has the advantage of maximizing the portion of the path of the light beam 5 through the prism glass and thus maximizing the compression effect described above.

However, because of the reflective surface 17 formed by the hypotenuse 25, the prism is not transparent, as it fully reflects rays from target 14, as shown in Figure 9.

To solve this problem, the prism 24 can be replaced by a separator cube 26, i.e. an assembly of two straight prisms joined by their hypotenuse 25, the latter being covered with a glue or a suitable coating which makes the reflective surface formed by the hypotenuse 25 semi-transparent and the set 26 as shown in Figure 10.

Another variant of an optical element according to the invention is shown in Figure 11 which shows an optical element 20 in the form of the reflecting surface 17 made as a curved surface whose convexity is turned towards the rotating mirror 9.

It is obvious that the invention is by no means limited to the examples described above but that many modifications can be made to the red dot movable sights described above without going beyond the scope of the invention as defined in the following claims.

Claims (14)

1. A red dot viewfinder, consisting of a fixed light source (4); a rotating mirror (9); a reflecting surface (17), the light source (4) generating a collimated light beam (5) which is projected onto the reflecting surface (17) to make a red or reticulated point visible to the shooter (19) by reflection onto the reflecting surface (17), the beam (5) being projected onto the reflecting surface (17) by means of the rotating mirror (9) whose inclination angle (B) relative to the light beam (5) is adjustable to adjust the angle of view (D) relative to the red point under which the shooter (19) is observed from a reference direction (X-X') and this angle is within a minimum angle between the target and a target angle,characterised by the sight (1) comprising at least one optical element (20) located in the path of the light beam (5) between the rotating mirror (9) and the eye of the shooter (19) so that the light beam (5) is deflected along its path between the moving mirror (9) and the eye of the shooter (19), the shape of this element (20) being such that the deflections it causes on the light beam (5) have the effect of reducing the path (OI) travelled by it between the rotating mirror (9) and the reflecting surface (17) for the same angle of view,at least in part of the above range of angles of vision.
2. A viewfinder according to claim 1, characterised by the shape of this element (20) such that the deviations it causes from the light beam (5) have the effect of reducing the path (OI) travelled by the light beam between the rotating mirror (9) and the reflecting surface (17) for the same viewing angle, at least in the region of the viewing angles close to the maximum viewing angle (D).
3. A viewfinder according to claim 1 or 2, characterised by the optical element (20) comprising at least one transparent element (21,22,24,26) which is located in the path of the light beam (5) between the rotating mirror (9) and the shooter's eye (19) and which deflects, by refraction, the rays of the collimated light beam (5) and alters their impact on the reflecting mirror (9) in relation to a situation with the same angle of view (D) but without this optical element (20).
4. A viewfinder according to claim 3, characterised by the optical element (20) being located in the path of the light beam (5) between the rotating mirror (9) and the reflecting surface (17).
5. A viewfinder according to claim 3 or 4, characterised by the optical element (20.21) being rectangular in cross-section in the plane of the beam (5).
6. A viewfinder according to claim 3 or 4, characterised by the optical element (20.22) being triangular in cross-section in the plane of the beam (5).
7. A viewfinder according to claim 3 or 4, characterised by the optical element (20) comprising an isosceles (24) straight prism with the hypotenuse (25) acting as a reflecting surface (17).
8. Visor according to any of the above claims, characterised by the reflective surface (17) being a semi-transparent surface.
9. Visor according to figure 8, characterised by the optical element (20) comprising a separating cube (26), i.e. a set of two prisms (24) joined with their hypotenuse (25) against each other, the contact surface of which is covered by an appropriate glue or coating which makes the set (26) semi-transparent.
10. A viewfinder according to any of the above claims, characterised by the optical element (20) having a curved surface (17).
11. The optical element (20) is formed by the above reflective surface (17) as a curved surface with the convexity turned towards the rotating mirror (9).
12. A viewfinder according to any of the above claims, characterised by a maximum angle of view of the order of 40° or more.
13. A movable red-point viewfinder, comprising a fixed light source (4); a rotating mirror (9); a reflecting surface (17), the light source (4) generating a collimated light beam (5) which is projected onto the reflecting surface (17) to make a red or reticulated point visible to the shooter (19) by reflection onto the reflecting surface (17), the beam (5) being projected onto the reflecting surface (17) by means of the rotating mirror (9) whose incision angle (B) relative to the light beam generated (5) is adjustable to adjust the angle of incision (Dau) to reduce the red point below which the light beam is observed (19) in a reference direction (X-X') (17) to achieve the maximum angle of incidence of light in the direction of the reflecting surface (5), so that the maximum angle of incision (L) is within the range of the optical distance required to reach the objective (L) (5) in order to achieve the maximum angle of incidence of light in the direction of the reflecting surface (5), which is the maximum distance between the objective and the reflecting surface of the objective.
14. A red dot viewfinder, consisting of a fixed light source (4); a rotating mirror (9); a reflecting surface (17), the light source (4) generating a collimated light beam (5) which is projected onto the reflecting surface (17) to make a red or reticulated point visible to the shooter (19) by reflection onto the reflecting surface (17), the beam (5) being projected onto the reflecting surface (17) by means of the rotating mirror (9) whose inclination angle (B) relative to the light beam (5) is adjustable to adjust the angle of view (D) relative to the red point under which the shooter (19) is observed from a reference direction (X-X') and this angle is within a minimum angle between the target and a target angle,characterised by the sight (1) comprising at least one optical element (20) located in the path of the light beam (5) between the rotating mirror (9) and the eye of the shooter (19) so that the light beam (5) is deflected on its path between the rotating mirror (9) and the eye of the shooter (19), the shape of this optical element (20) being such that the deflections it causes on the light beam (5) have the effect of reducing the path travelled by the point of incidence of the light beam (5) on the reflecting surface (17) by rotation of the rotating mirror (9) between two angles of view,at least in part of the above range of angles of vision.