SYSTEM FOR AUGMENTED REALITY

Abstract

A system for augmented reality comprises a helmet and a container body within which a video unit is housed that comprises a device for acquiring images of a real scene and a display device for displaying at least the aforementioned images. A support body is, furthermore, provided configured to engage the container body to the helmet. The container body and the support body are provided with respective first and second engagement members configured to selectively and alternatively removably engage the container body to the support body in a first engagement position, in which the device for acquiring images is arranged to acquire images with a first predetermined field of view and the display device is positioned within the field of view of the user, and at least a second engagement position, in which the device for acquiring images is arranged to acquire images with a second predetermined field of view.

Claims

1. A system for augmented reality comprising: a helmet configured to be worn by a user; a container body arranged to house a video unit, said video unit comprising: a device for acquiring images configured to acquire images of a real scene; a display device configured to display at least said images of said real scene acquired by said device for acquiring images; a support body configured to engage said container body to said helmet; a transmission unit configured to transmit said images acquired by said device for acquiring images to a remote location; said system being characterized in that said container body and said support body are provided with respective first and second engagement members configured to selectively and alternatively removably engage said container body to said support body in a first predetermined engagement position, in which said device for acquiring images is arranged to acquire images of said real scene with a first predetermined field of view (FoV1) and said display device is positioned in the field of view of the user, and at least a second predetermined engagement position, in which said device for acquiring images is arranged to acquire images of said real scene with a second predetermined field of view (FoV2), and said display device is positioned externally to the field of view of the user and in that said transmission unit is arranged to transmit said images of said real scene acquired by said device for acquiring images, to said remote location also when said container body is positioned in said second predetermined engagement position.

2. System for augmented reality, according to claim 1, wherein said container body and said support body comprise respective first and second engagement surfaces respectively provided with said respective first and second engagement members, said first and second engagement surfaces being arranged to selectively and alternatively reversibly engage with each other, by said first and second engagement members to position said container body in said first, or in said second, predetermined engagement position with respect to said support body.

3. System for augmented reality, according to claim 2, wherein said first engagement surface and said second engagement surface of said container body form an angle α of predetermined amplitude, said angle α being comprised between −10° and 10°, i.e.: −10°≤α≤10°.

4. System for augmented reality, according to claim 1, wherein said support body comprises: a base portion arranged to be engaged a said helmet; a movable portion hinged a said base portion, said movable portion being configured to rotate about a rotation axis with respect to said base portion, in such a way to allow to adjust the inclination of container body with respect to the base portion and, therefore, with respect the user, when said container body is arranged to engage said support body in said first predetermined engagement position.

5. System for augmented reality, according to claim 2, wherein at least said container body, at said respective first and second engagement surfaces is, furthermore, provided with respective guide portions configured to guide the positioning of said container body with respect to said support body, up to engaging said first, or second, engagement member.

6. System for augmented reality, according to claim 5, wherein said, or each, guide portion comprises a recessed portion provided at least in one between said first and second engagement surfaces of said container body, said, or each, recessed portion being configured to house said first, or said second, engagement surface of said support body.

7. System for augmented reality, according to claim 1, wherein said first and second engagement members are configured to magnetically engage said container body and said support body with each other.

8. System for augmented reality, according to claim 7, wherein at least said second engagement members of said container body and of said support body are of magnetic type and comprise a respective neodymium magnet, in such a way to provide a self-centering of said second engagement members owing to the high magnetic force and, therefore, a correct positioning of said container body with respect to said support body.

9. System for augmented reality, according to claim 1, wherein said first engagement members of said container body and of said support body comprise, respectively, a magnet and at least a portion made of paramagnetic material, in such a way to allow an axial movement between said container body and said support body before engaging said first engagement members with each other at said first predetermined engagement position.

10. System for augmented reality, according to claim 2, wherein said first and second engagement surfaces are configured in such a way that said first predetermined field of view (FoV1) is substantially equal to said second predetermined field of view (FoV2).

11. System for augmented reality, according to claim 1, wherein a tightening group is, furthermore, provided configured to engage said, or each, container body to said helmet.

12. System for augmented reality, according to claim 11, wherein said tightening group comprises: a tightening cable arranged to be constrained to said, or each, container body at a respective constraining portion; a stretching device configured to move from a rest configuration, in which is not arranged to apply a traction force on said tightening cable, to a stretching configuration, in which said stretching device is arranged to apply a determined traction force on said tightening cable, in such a way to cause said tightening cable to move from a positioning configuration, in which said tightening cable is slack and can be, therefore, positioned around said helmet, and a tightening configuration, in which said tightening cable is subject to said determined traction force per cui is arranged to tighten said, or each, constraining portion to said external surface of said helmet to firmly engage said, or each, container body a said helmet, at a respective predetermined engagement position.

13. System for augmented reality, according to claim 1 wherein is, furthermore, provided a second container body is, furthermore, provided arranged to house a supply unit operatively connected to at least one between said device for acquiring images and said images display device to supply electric power.

14. System for augmented reality, according to claim 12, wherein said stretching device comprises a fixed portion arranged to engage said helmet and a movable portion rotatably connected to said fixed portion, said movable portion being configured to rotate about a rotation axis with respect to said fixed portion in a first direction of rotation to cause said tightening cable to be wound around a winding shaft in such a way to apply said traction force on said tightening cable, and in a second direction of rotation, opposite to the first, to unwind said tightening cable from said winding shaft and to reduce said traction force and wherein a first engagement body is, furthermore, provided having a first engagement portion configured to engage said edge of said helmet, and wherein first supplementary engagement members are provided configured to removably engage said fixed portion of said stretching device and said first engagement body, said first supplementary engagement members being configured in such a way to allow said movable portion to rotate with respect to said fixed portion.

15. (canceled)

16. System for augmented reality, according to claim 14, wherein are furthermore provided: a second engagement body associated to said first container body, said second engagement body being provided with a first constraining portion and a second engagement portion configured to engage said second engagement body a said edge of said helmet at said first predetermined engagement position; second supplementary engagement members configured to removably engage said first container body and said second engagement body.

17. System for augmented reality, according to claim 15, wherein are, furthermore, provided: a third engagement body associated to said second container body, said third engagement body being provided with said second constraining portion and a third engagement portion configured to engage said second container body a said edge of said helmet at said second position; third supplementary engagement members configured to removably engage said second container body and said third engagement body.

18-21. (canceled)

22. System for augmented reality, according to claim 12, wherein at least one among said first, second and third engagement portion comprises at least an end portion configured to resiliently move from a closing configuration, to an opening configuration in which is arranged to form an introduction mouth through which said edge is arranged to be introduced at a shaped engagement portion, and then to go back in said closing configuration, in which is arranged to close, at least partially, said introduction mouth, trapping said edge into said shaped engagement portion and wherein said shaped engagement portion is an undercut.

23. (canceled)

24. System for augmented reality according to claim 1, wherein said first and said second engagement members are configured to move from said first predetermined engagement position to said second predetermined engagement position, or vice versa, passing through an intermediate engagement position, in which said container body is mechanically disengaged from said support body.

25. System for augmented reality according to claim 1, wherein said container body is arranged to house said transmission unit.

26. A system for augmented reality comprising: a helmet configured to be worn by a user said helmet being provided with an external surface and an internal surface linked by an edge; a container body arranged to house at least a video device selected from the group comprising: a device for acquiring images configured to acquire images of a real scene; a display device configured to display images of a real scene; said system being characterized in that a tightening group is, furthermore, provided configured to engage said, or each, container body to said helmet, said tightening group comprising: a tightening cable arranged to be constrained to said, or each, container body at a respective constraining portion; a stretching device configured to move from a rest configuration, in which is not arranged to apply a traction force on said tightening cable, to a stretching configuration, in which said stretching device is arranged to apply a determined traction force on said tightening cable, in such a way to cause a movement from a positioning configuration, in which said tightening cable is slack and is, therefore, possible to position the same around said helmet, and a tightening configuration, in which said tightening cable is subject to said determined traction force per cui is arranged to tighten said, or each, constraining portion to said external surface of said helmet to firmly engage said, or each, container body to said helmet, at a respective engagement position.

27-37. (canceled)

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0061] The invention will now be shown with the following description of its exemplary embodiments, exemplifying but not limitative, with reference to the attached drawings in which:

[0062] FIG. 1A diagrammatically shows a side elevation view of a first embodiment of a system, according to the invention, for augmented reality;

[0063] FIG. 1B diagrammatically shows a side elevation view of a first alternative embodiment of the system for augmented reality of FIG. 1A;

[0064] FIG. 2 diagrammatically shows a side elevation view of the video unit of the system according to the invention in the first predetermined engagement position;

[0065] FIG. 3 diagrammatically shows a side elevation view of video unit of the system according to the invention in the second predetermined engagement position;

[0066] FIG. 4 diagrammatically shows the functioning of the system for augmented reality according to the invention, when the video unit is positioned in the first predetermined engagement position;

[0067] FIG. 5 diagrammatically shows the functioning of the system for augmented reality according to the invention, when the video unit is positioned in the second predetermined engagement position;

[0068] FIG. 6 diagrammatically shows a side elevation view of a possible embodiment of the system according to the invention, in the first predetermined engagement position;

[0069] FIG. 7 diagrammatically shows a side elevation view of another possible embodiment of the system according to the invention, in the first predetermined engagement position;

[0070] the FIGS. 8 and 9 diagrammatically show, respectively, a perspective view from the above, and a perspective view from below, of an embodiment provided for the container body of the video unit of the system according to the invention;

[0071] FIG. 10 diagrammatically shows a side elevation perspective view of a possible embodiment of the system, according to the invention, for augmented reality;

[0072] FIG. 11 shows a possible scheme of functioning alternative to that one of FIG. 4 of the system, according to the invention, for augmented reality;

[0073] FIG. 12 shows a plan view of the system for augmented reality in a rest configuration;

[0074] FIG. 13 shows a side elevation view of the actuation of the stretching device by a user for applying a traction force on the tightening cable of the system of FIG. 12;

[0075] FIG. 14 shows a plan view of the system for augmented reality of FIG. 12 in the stretching configuration;

[0076] FIGS. 15 and 16 show side elevation perspective view of the stretching device, respectively disengaged from and engaged with the first engagement body;

[0077] FIG. 17A diagrammatically shows a perspective view from the above of the second engagement body provided by the invention;

[0078] FIG. 17B diagrammatically shows side elevation perspective view of the movement of the end portion of the engagement portion from a closing configuration to an opening configuration and vice versa;

[0079] FIG. 18 diagrammatically shows a side elevation perspective view of the third engagement body according to the invention;

[0080] FIGS. 19 and 20 diagrammatically show, respectively, side elevation perspective views of further embodiments of the hook member foreseen by the system for augmented reality according to the present invention.

DETAILED DESCRIPTION OF SOME EXEMPLARY EMBODIMENTS OF THE INVENTION

[0081] As diagrammatically shown in FIG. 1A, a system 1, according to the invention, for augmented reality comprises a helmet, or head armor, 50 configured to be worn by a user 200 (see FIGS. 4 and 5), a container body 15 arranged to house a video unit 10. This can provide a device for acquiring images 11, in particular a digital video camera, configured to acquire the images 301 of a real scene 300, and/or a display device 12 configured to display at least the aforementioned images 301 acquired by the device for acquiring images 11. In the preferred embodiment shown for example in FIG. 1, the video unit 10 comprises both the device for acquiring images 11 and the display device 12. More in detail, the container body 15 can be provided with only one lens 13, and, therefore, be a monocular visor. Preferably, the container body 15 of system 1 is provided with a first and a second lens 13 and, therefore, is a binocular visor. Through the, or each, lens 13 the user 200 can watch the display device 12 installed within the container body 15. The system 1, furthermore, comprises a support body 40 configured to engage the container body 15 to the helmet 50, preferably at the front edge 58 of the same. According to the invention, the container body 15 and the support body 40 are provided with respective first engagement members 31a, 32a, and second engagement members 31b, 32b configured to selectively and alternatively removably engage the container body 15 to the support body 40 in a first predetermined engagement position, in which the device for acquiring images 11 is arranged to acquire images of the real scene 300 with a first predetermined viewing angle φ1, and the display device 12 is positioned in the field of view of the user 200, and at least a second predetermined engagement position, in which the device for acquiring images 11 is arranged to acquire images 301 of the real scene 300 with a second predetermined viewing angle φ2 and the display device 12 is positioned outside of the field of view of the user 200. The first and the second predetermined engagement positions are, advantageously, predetermined positions in which the container body 15 can be positioned with respect to the support body 40. In this way, the user 200 is, in particular, able to reach the container body 15 without looking away from the real scene 300 to bring the same back from the second position to the first position.

[0082] In particular, the first and the second engagement members 31a, 32a, 31b, 32b can be configured to move from the first predetermined engagement position to the second predetermined engagement position, or vice versa, passing through an intermediate engagement position in which the container body 15 is mechanically disengaged from the support body 40.

[0083] In a preferred embodiment of the invention, diagrammatically shown in FIG. 1B, the system 1 comprises, preferably, also a transmission unit 80, for example housed within the container body 15, operatively connected to the video unit 10 and configured to send the aforementioned images 301 of the real scene 300 acquired by the device for acquiring images 11 to a remote location 250. In particular, at the remote location 250 can be, advantageously, positioned an expert worker who guides, by the system 1, the actions of user 200 who wears the helmet 50. More in particular, when the container body 15 is positioned in the second predetermined engagement position, the device for acquiring images 11 is advantageously arranged to acquire images 301 of the real scene 300. More in particular, the acquired images 301 are, then, transmitted by the transmission unit 80 to the remote location 250 in such a way that the actions of the user are, anyway, monitored and/or recorded in order to verify that they are correct.

[0084] In particular, the transmission unit 80, for example comprising a WIFI card, can be, furthermore, configured to receive a series of supplementary images 302, for example virtual images, or annotations, which can be displayed on the display device 12 together with, or alternatively to, the aforementioned images 301 of the real scene 300. In particular, the aforementioned supplementary images 302 can be generated by the expert worker, for example by a PC, a tablet, or another electronic device, and sent, for example via internet to the transmission unit 80. The supplementary images 302 can be, therefore, processed, for example, to be decoded, by a local processing unit that is not shown for reasons of simplicity, provided on board of the helmet 50, in order to be, then, displayed on display device 12.

[0085] In particular, if on the display device 12 are displayed at the same time both the images 301 and the supplementary images 302, for example superimposed on one another, complex images 303 are obtained. In a possible alternative embodiment of the invention, the remote location 250 can be configured to generate the aforementioned supplementary images 302, or directly the complex images 303 comprising the aforementioned images 302 and the aforementioned images 301, for example superimposed on one another, and to send them to the transmission unit 80.

[0086] In particular, the aforementioned supplementary images 302, can comprise contents as for example written instructions, or annotations, can be displayed on the aforementioned display device 12 to guide the user 200 who is wearing the helmet 50, during some works, both in mechanical field, for example to assembly together the parts of a machine, and in electric field, for example during an ordinary, or extraordinary maintenance intervention, on an electronic control unit, but also in surgical field to carry out an operation, etc.

[0087] According to an alternative embodiment, the aforementioned supplementary images 302 can be generate from a local processing unit, not shown for reasons of simplicity, for example, housed within the container body 15.

[0088] In an embodiment of the invention, diagrammatically shown in FIG. 5, a second container body 25 can be provided, for example engaged to the helmet 50 at a rear portion, within which at least a supply unit 150 can be housed, for example comprising at least a battery, preferably a rechargeable battery, arranged to supply electric power to the video unit 10 and to the transmission unit 80. Advantageously, in the aforementioned intermediate engagement position, the video unit 10 is operatively connected, for example by cable, not shown in the figure for simplicity reasons, to the aforementioned supply unit 150.

[0089] In particular, the second container body 25 can be engaged to helmet 50 by a supplementary support body 40′ provided with an engagement portion configured to engage the helmet 50 and with the engagement members for engaging the supplementary support body 50′, not shown in the figure for reasons of simplicity.

[0090] The system 1, according to the invention, can advantageously comprise, furthermore, an audio unit 60, preferably engaged to the aforementioned helmet 50, for example in a lateral position 51 and comprising, in particular an audio transmission device 61, as for example a microphone, and an audio receiving device 62.

[0091] More in particular, as diagrammatically shown in FIG. 4, the audio unit 60 can be connected to the supply unit 150, and to a respective audio transmission unit 160, for example housed within the second container body 25, in such a way that the user 200 can also verbally communicate with the expert worker positioned in the aforementioned remote location 250. In particular, at least one between the video unit 10 and the audio unit 60 can be connected to the respective transmission unit 80 and 160 by a wireless connection, for example, by Bluetooth connection, or WIFI connection. As diagrammatically shown in FIG. 10, furthermore, the video unit 10 and the audio unit 60 can be connected to the supply unit 150 by respective wires 6 and 7.

[0092] In a preferred embodiment, the container body 15 and the support body 40 comprise respective first and second engagement surfaces 16, 17, and 46, 47, respectively, provided with the aforementioned respective first and second engagement members 31a, 32a, and 31b, 32b. More in detail, the first and the second engagement surfaces 16, 17, 46, and 47 are arranged to selectively and alternatively removably engage, by the aforementioned first and second engagement members 31a, 32a, and 31b, 32b, to move the container body 15 in the first, or the second predetermined engagement position, with respect to the aforementioned support body 40.

[0093] In an embodiment of the invention, diagrammatically shown for example in FIG. 3, the support body 40 comprises a base portion 41 configured to be engaged to the helmet 50, and a movable portion 42 hinged to the base portion 41. More in particular, the movable portion 42 is arranged to rotate about a rotation axis 142 with respect to the base portion 41, in order to allow the user to adjust the inclination of the container body 15 and, in particular, of the display device 12, with respect to the base portion 41, when the video unit 10 is engaged to the support body 40 in the first position. In particular, the aforementioned movable portion 42 can be hinged to the aforementioned base portion 41 by a constant friction hinge. More in particular, in this way the rotation of the movable portion 42 with respect to the base portion 41 can be adjusted in such a way that the angle which is formed between them does not exceed a predetermined range of values, for example comprised between 10° and 70°, preferably comprised between 20° and 60°.

[0094] More in detail, the support body 40 comprises an engagement portion 43 configured to engage the base portion 41 of the support body 40 to the helmet 50, in particular at the front edge 58. For example, the engagement portion 43 can provide one or more shaped portions, for example curved, such as one, or more clip portions, able to deform in a controlled way in order to engage the edge of the aforementioned front edge 58.

[0095] Preferably, the first and the second engagement members 31a, 32a, 31b, 32b are configured to provide a magnetic engagement between the container body 15 and the support body 40.

[0096] In particular, at least the second engagement members 31b and 32b of magnetic type of the container body 15 and the support body 40 provide a respective neodymium magnet. This particular solution allows to provide a self-centering of the two magnets 32a, and 32b with respect to each other and, therefore, a correct positioning of the container body 15 with respect to the support body 40 in the second position, owing to the high magnetic force that this kind of material is able to exert.

[0097] In a possible embodiment of the invention, diagrammatically shown in FIG. 7, the first engagement members 31a and 32a of the container body 15 and of the support body 40 comprise, respectively, a magnet 31a, for example a neodymium magnet, and at least a portion made of paramagnetic material 32a. In this way, the magnetic force applied between the two parts allows to carry out a movement, in particular an axial movement, between the container body 15 and the support body 40, before carrying out the aforementioned engagement between the same by the first engagement members 31a and 32a, at the first predetermined engagement position. This solution allows, therefore, to the user 200 to adjust the distance of the video unit 10.

[0098] In a preferred embodiment, the aforementioned first and second engagement surfaces 16, 17, 46 and 47 and/or the first and the second engagement members 31a, 32a, 31b, 32b, can be configured in such a way that the field of view FoV1 of the device for acquiring images 11 in the first predetermined engagement position, is, advantageously, substantially equal to the field of view Fov2 of the device for acquiring images 11 in the second predetermined engagement position (see FIG. 5).

[0099] In this way, expert worker point of view at the remote location does not change according to the changing of the predetermined engagement position between the container body 15 and the support body 40.

[0100] As diagrammatically shown for example in the FIGS. 2 and 3, the first engagement surface 16 and the second engagement surface 17 of the container body 15 can be substantially parallel to each other. Advantageously, also the first engagement surface 46 and the second engagement surface 47 of the support body 40 are substantially parallel to each other.

[0101] More in detail, the aforementioned first engagement surface 16 and the aforementioned second engagement surface 17 of the container body 15 can be slightly inclined one with respect to the other, in such a way to form an angle α comprised between −10° and 10°, i.e. −10°≤α≤10°, advantageously comprised between −5° and 5°, i.e. −5°≤α≤5°, preferably comprised between 0° and 5°, i.e. 0°≤α≤5°. Analogously, the aforementioned first engagement surface 46 and the aforementioned second engagement surface 47 of the support body 40 can form an angle β, of predetermined amplitude. In particular, the aforementioned angle β, can be comprised between −20° and 20°, i.e.: −20°≤β≤20°, advantageously the angle β, can be comprised between −10° and 10°, i.e.: −10°≤β≤10°, preferably comprised between −5° and 5° i.e.: −5°≤β≤5°.

[0102] Generally, the geometry of the container body 15 and the support body 40 are such to keep the field of view FoV of the device for acquiring images 11 substantially unchanged between the first and the second predetermined engagement position. In this way, in the second predetermined engagement position the user 200 can directly look at the real scene 300 to work more precisely on the mechanical, or electrical, parts or of any other type, while the expert worker positioned at the remote location can have the same field of view of the real scene 300 avoiding to lose the reference points.

[0103] In particular, as shown in detail in the embodiment diagrammatically shown in the FIGS. 8 and 9, at least one between the container body 15 and the support body 40, at least one of the aforementioned engagement surfaces 16, or 17, or 46, or 47, can be provided with a guide portion 18, or 48. More in particular, the, or each, guide portion 18a, or 48a, is configured to guide the engagement of the container body 15 with the support body 40, in the first, or in the second, position. In a preferred embodiment, at least one between the container body 15 and the support body 40, at both the aforementioned engagement surfaces 16 and 17, or 46 and 47, can be provided with a guide portion 18a and 18b, or 48a and 48b. For example, the, or each, guide portion 18a, or 18b, or 48a, or 48b, can provide a recessed portion, in particular grooved, or a protruding portion. More precisely, the, or each guide portion 18a, or 18b, can be laterally delimited by walls 19a and 19b arranged to guide the correct positioning of the container body 15 with respect to the support body 40 up to the engagement of the same in the first, or the second engagement position by first, or second, engagement members 31a, 31b, 32a, 32b. In an embodiment of the invention, at least the size of one between the first and the second engagement surfaces 46 and/or 47 of the support body 40 can be chosen in such a way to have a width substantially equal to the width of the aforementioned guide portion 18a, or 18b, of the first and/or the second engagement surface 16 and/or 17 of the container body 15. In this case, the correct positioning of the container body 15 with respect to the support body 40 in the first and/or in the second engagement position, is caused both by the magnetic force exerted by magnets 31a, 31b and 32a, 32b and by the, or each, guide portion 18a, or 18b.

[0104] The system 1 can, furthermore, provide a detection group, not shown in figure, comprising one, or more sensors, in particular at least a position sensor and/or an accelerometer, in case, in addition to a GPS unit, for determining the position and the spatial orientation of the user 200 with respect to the real scene 300 acquired by the device for acquiring images 11.

[0105] As diagrammatically shown in the figures from 10 to 20, the system 1, according to the invention, can comprise, furthermore, a tightening group 70 configured to engage the, or each, container body 15, and/or 25, to helmet 50, in particular at an edge 55. More in particular, the edge 55 can have a thickness greater than the other parts of helmet 50, and have, for example, a curvilinear section. In particular, the tightening group 70 can provide a tightening cable 5 arranged to engage the, or each, container body 15 at a respective constraining portion 35. The tightening group 70 can, furthermore, comprise a stretching device 100 configured to apply a determined traction force to the tightening cable 5. More precisely, the stretching device 100 can be arranged to move, preferably gradually, from a rest configuration, in which is not arranged to apply a traction force to the tightening cable 5, or to apply a low traction force, to a stretching configuration, in which the stretching device 100 is arranged to apply a determined traction force to the tightening cable 5. In this way, the stretching device 100 is arranged to cause the tightening cable 5 to move, preferably gradually, between a positioning configuration, in which the tightening cable 5 is slack and is, therefore, possible to position the same around the helmet 50 (see FIG. 12), and a tightening configuration, in which the tightening cable 5 is subject to the aforementioned determined traction force and is arranged to tighten the, or each, constraining portion 35 to the external surface 56 of helmet 50 in order to firmly engage the, or each, container body 15 and/or 25 to the helmet 50 (see FIG. 14).

[0106] Advantageously, the stretching device 100, according to the present invention, can comprise a blocking member arranged to avoid that, when the tightening device 100 is positioned in the aforementioned stretching configuration, can accidentally go back to the rest configuration, reducing, even to zero, the aforementioned traction force on the tightening cable 5. Therefore, the stretching device 100 is configured in such a way to be blocked by itself in the stretching configuration.

[0107] In particular, the stretching device 100 which can be used by the system 1, according to the present invention, can be structurally similar to the stretching devices described in US2008/0066346, US2015/0230560, or US2015/0076272 used in the field of shoes with different purposes with respect to the present invention.

[0108] In the case that is diagrammatically shown as an example in the figures from 10 to 14, the system 1 provides a first and a second container body 15 and 25. More in detail, the first container body 15 can be arranged to house both the device for acquiring images 11 arranged to acquire the images 301 of the real scene 300, and the display device 12 arranged to display the aforementioned images 301. The second container body 25 can be arranged to house the supply unit 150 configured to supply electric power to the device for acquiring images 11 and to the display device 12. In particular, the first container body 15 is provided with a first engagement portion 35, and the second container body 25 is provided with a second engagement portion 45. More precisely, the first container body 15 is tightened to the helmet 50 at a first engagement position 51, preferably the front portion of the helmet 50, while the second container body 25 is tightened to the helmet 50 at a second engagement position 52, preferably the rear position of the helmet 50.

[0109] As diagrammatically shown in FIG. 13, the actuation of the stretching device 100 in order to subject the tightening cable 5 to the aforementioned traction force can be caused by acting on an actuation portion 105, for example an actuation knob.

[0110] In a preferred embodiment of the invention, the stretching device 100 can comprise a fixed portion 101 engaged to the helmet 50, and a movable portion 102 rotatably connected to the fixed portion. More in detail, as diagrammatically shown in the FIGS. 15 and 16, the movable portion 102 can be configured to rotate around a rotation axis 120 with respect to the fixed portion 101, in a first direction of rotation 121 to cause the tightening cable 5 to be wound around a winding shaft 126 in such a way to apply the aforementioned traction force on the tightening cable 5, or in a second direction of rotation 122, opposite to the first, to unwind the tightening cable 5 from the aforementioned winding shaft 126 and to reduce, in this way, the traction force up to reaching the aforementioned positioning configuration in which the tightening cable 5 is slack. In a foreseen embodiment, the aforementioned stretching device 100 can be associated to a first engagement body 115. The aforementioned rotation of the movable portion 102 with respect to the fixed portion 101 can be obtained by acting on the aforementioned actuation portion 105, for example an actuation knob. More in detail, the first engagement body 115 can be provided with a first engagement portion 133 configured to engage the edge 55 of helmet 50, shown in transparency in FIG. 15, for example forming an undercut. The first engagement body 115 and the stretching device 100 can be provided with first supplementary engagement members 110 configured to removably engage the aforementioned fixed portion 101 of the stretching device 100 and the first engagement body 115. More in particular, the first supplementary engagement members 110 are configured in such a way to allow the movable portion 102 to rotate with respect to the fixed portion 101. In the embodiment diagrammatically shown in the FIGS. 15 and 16, the first supplementary engagement members 110 comprise first engagement walls 111 at the engagement body 115 and second engagement walls 112 at the fixed portion 101. As described above, the engagement walls 111 and 112 are configured to engage the fixed portion 101 to the first engagement body 115 and, therefore, to the helmet 50, and, anyway, to allow the movable portion 102 to rotate about the rotation axis 120.

[0111] As diagrammatically shown in FIG. 17A, a second engagement body 30 can be provided associated to container body 15. More in detail, the second engagement body 30 can be provided with the aforementioned constraining portion 35 and with a second engagement portion 33 configured to engage the second engagement body 30 to the edge 55 of helmet 50, in particular at the first engagement position 51. In particular, second supplementary engagement members 130 are, furthermore, provided configured to removably engage the container body 15 and the second engagement body 30.

[0112] In the example that is diagrammatically shown in FIG. 17A, the second supplementary engagement members 130 comprise a second engagement member 131a at the second engagement body 30, for example at a fixing protruding portion 135 of the same, arranged to engage the engagement member 31a (see FIG. 8) of container body 15. In a preferred embodiment, at least one between the engagement member 131a and the engagement member 31a is a magnet, preferably a neodymium magnet, and the other engagement member 31a, or 131a, is an element made of a paramagnetic material. In an alternative embodiment of the invention, the first and the second engagement member 31a and 131a are two magnets, for example two neodymium magnets.

[0113] As shown in FIG. 11, in an embodiment provided by the invention, the system 1 can, furthermore, provide a third engagement body 40′ associated to the second container body 25. The third engagement body 40′ can be provided with the second constraining portion 45 and a third engagement portion 43 configured to engage the edge 55 of helmet 50. In particular, third supplementary engagement members 140 can be furthermore provided configured to removably engage the second container body 25 and the third engagement body 40′. For example, the third supplementary engagement members 140 can provide a first engagement hole 141 at a fixing portion 145 of the third engagement body 40, a second engagement hole 142 at the second container body 25 and an elongated member 145 arranged to engage in the first and in the second engagement hole 141 and 142. In particular, the first and the second engagement hole 141 and 142 and the elongated member 145 can be threaded in such a way to provide a threaded coupling. In particular, in the examples of FIGS. 9 and 11, the first and the second constraining portion 35 and 45, respectively, of the second and the third engagement body 30 and 40′, are provided with respective passageways 34 and 44. In particular, each passageway 34, or 44, is arranged to cross the first, or the second, constraining portion 35, or 45, between a first and a second side. More in particular, the aforementioned tightening cable 5 is arranged to be constrained to the first, or the second, constraining portion 35, or 45, at the aforementioned passageway 34, or 44.

[0114] In the embodiment shown as an example in the FIGS. 17A and 17B, the engagement body 30 comprises at least a second engagement portion 33. More in particular, the, or each, second engagement portion 33 comprises a respective end portion 36 configured to resiliently move from a closing configuration (indicated in FIG. 17B with an unbroken line) to an opening configuration (indicated in FIG. 17B with a broken line) in which forms a respective introduction mouth 37. More precisely, through the aforementioned introduction mouth 37, the edge 55 of helmet 50 can be positioned at a respective shaped engagement portion 38, for example forming an undercut. Then, the, or each, end portion 36, that is not anymore subjected to the force that has caused the aforementioned elastic deformation, is arranged to go back in the aforementioned closing configuration, in which closes, at least partially, the respective introduction mouth 38, practically, trapping the edge 55 of helmet 50 in the shaped engagement portion 38.

[0115] As diagrammatically shown in the FIGS. 19 and 20, the tightening group according to the invention can, furthermore, comprise at least a hook member 90 arranged to engage the edge 55 of helmet 50 at least a portion of the aforementioned tightening cable 5 at a third engagement position 53, in particular interposed between the first and the second engagement position 51 and 52. In the example of FIGS. 12 and 13, the hook member 90 is configured to engage the helmet 50, in addition to the tightening cable 5, also to the connection cable 6 arranged to connect the, or each, audio device 11, or 12, to the supply unit 150. According to an embodiment that is not shown in the figures, the, or each, hook member 90 can be arranged to engage the helmet 50 only at connection cable 6.

[0116] In this way, it is possible to avoid that portions of the tightening cable and/or the connection cable 6 can be free to dangle along the respective trajectory around the helmet 50. More precisely, the hook member 90 can be provided with a respective engagement portion 93 arranged to engage the edge 55 of helmet 50, for example having the characteristics described above with reference to FIG. 9B for the secondo engagement body 30. Furthermore, as diagrammatically shown in FIG. 20, the hook member 90 can be provided with a first passageway 94a arranged to house, in use, the tightening cable 5, and a second passageway 94b arranged to house, in use, the aforementioned connection cable 6.

[0117] According to an embodiment of the invention, the second container body 25 in addition to the supply unit 150, can be arranged to house a sound card, and/or a video card, not shown for simplicity reasons, respectively connected to the audio unit 60 and to the, or each, video device 11, or 12.

[0118] The system 1 can, furthermore, provide a detection group, not shown in figure, comprising one, or more sensors, in particular at least a position sensor and/or a accelerometer, in addition to a possible GPS unit, for determining the position and the spatial orientation of the user 200 with respect to the real scene 300 acquired by the device for acquiring images 11.

[0119] The foregoing description exemplary embodiments of the invention will so fully reveal the invention according to the conceptual point of view, so that others, by applying current knowledge, will be able to modify and/or adapt for various applications such embodiment without further research and without parting from the invention, and, accordingly, it is therefore to be understood that such adaptations and modifications will have to be considered as equivalent to the specific embodiments. The means and the materials to realize the different functions described herein could have a different nature without, for this reason, departing from the field of the invention. It is to be understood that the phraseology or terminology that is employed herein is for the purpose of description and not of limitation.