SECURITY SYSTEM FOR A WIRELESS POWER TRANSMISSION SYSTEM

Description

[0001] Field of invention

[0002] The present invention relates to a security system for a wireless energy transmission system, in particular for energy transmission via a laser beam.

[0003] State of the art

[0004] Wireless energy transfer technology involves the use of a laser beam transmission and reception system to achieve long-distance transmission of electrical energy without the need for physical connections, such as pylons and wiring.

[0005] In particular, the energy transmission system comprises at least one transmitter, configured to generate a laser beam, and an opposing receiver, configured to receive the laser beam generated by the transmitter. The receiver includes within it an energy conversion element, for example a photovoltaic element, for the conversion of the radiant energy of the laser beam into electrical energy.

[0006] This technology has numerous advantages, including the possibility of transmitting and distributing energy even in remote or inaccessible areas, as well as a reduction in the environmental impact that can be generated by the energy generation and transfer infrastructure.

[0007] For a wireless energy transmission system configured in this way, it is necessary to provide a safety system that reduces or eliminates the risk that the laser beam transmitted between the transmitter and receiver could cause damage, for example to people who inadvertently cross the laser beam.

[0008] There is also a need to provide a safety system with a high rapid response in dangerous conditions and which at the same time has reduced construction costs and complexity.

[0009] Solution

[0010] The aim of the present invention is to provide a security system for a wireless energy transmission system, in particular for energy transmission via a laser beam, more efficient than the known art.

[0011] A further particular aim of the present invention is to provide a safety system for a wireless energy transmission system, in particular for the transmission of energy via a laser beam, featuring a high response rate in dangerous conditions and which at the same time has reduced construction costs and complexity.

[0012] These and further objects are achieved by a security system for a wireless energy transmission system, in particular for energy transmission via a laser beam, according to independent claim 1.

[0013] The dependent claims refer to preferred and advantageous embodiments of the present invention.

[0014] Figure

[0015] To better understand the invention and appreciate its advantages, some of its exemplary and non-limiting embodiments will be described below, with reference to the attached figure, in which:

[0016] - Figure 1 is a front view of an emitter of a security system, according to an embodiment of the invention;

[0017] - Figure 2 is a front view of a security system emitter, according to a further embodiment of the invention;

[0018] - Figure 3 is a front view of a receiver of a security system, according to an embodiment of the invention;

[0019] - Figure 4 is a perspective view of a security system, showing visible and non-visible details, according to one embodiment of the invention;

[0020] - Figure 5 is a perspective view of components of a security system, according to an embodiment of the invention.

[0021] Description of some preferred embodiments

[0022] In this description, a safety system is generally designated by the reference number 1.

[0023] The security system 1 is suitable for integration into a wireless energy transmission system 2.

[0024] The safety system 1 comprises a transmitter 3 and a receiver 4.

[0025] The emitter 3 comprises an emission wall 7. The emitter 3 is configured to emit a collimated laser beam of power 5. In particular, the emitter 3 is configured to emit the laser beam of power 5 from the emission wall 7 in the direction of the receiver 4.

[0026] The laser beam of power 5 is configured to transmit electromagnetic radiation power.

[0027] The receiver 4 comprises a receiving wall 8. The receiver 4 is configured to receive the laser beam of power 5 emitted by the emitter 3. In particular, the receiver 4 is configured to receive such laser beam of power 5 on the receiving wall 8.

[0028] The laser beam of power 5 defines a transmission axis 6 extending between the emitter 3 and the receiver 4. The laser beam of power 5 is substantially coaxial with the transmission axis 6.

[0029] The transmission axis 6 intersects the emission wall 7 at a central emission point 9.

[0030] Furthermore, the transmission axis 6 intersects the receiving wall 8 at a central receiving point 10.

[0031] The security system 1 comprises an electronic processing unit, a plurality of first photosensitive sensors 11, a plurality of second photosensitive sensors 12 and a plurality of third photosensitive sensors 13.

[0032] The first photosensitive sensors 11 are configured to detect the laser beam of power 5, in particular to detect the electromagnetic radiation of the laser beam of power 5.

[0033] The first photosensitive sensors 11 are positioned in correspondence with the receiver 4.

[0034] The first photosensitive sensors 11 are positioned around the central receiving point 10, at a first radial distance R1 from the central receiving point 10.

[0035] The first radial distance R1 defines, in particular in combination with the drive axis 6, a first cylinder C1 coaxial with the drive axis 6.

[0036] “Radial distance” refers to the distance measured in the radial direction to the drive axis 6.

[0037] The second photosensitive sensors 12 are configured to detect the laser beam of power 5, in particular to detect the electromagnetic radiation of the laser beam of power 5.

[0038] The second photosensitive sensors 12 are positioned in correspondence with the receiver 4.

[0039] The second photosensitive sensors 12 are positioned around the central reception point 10, at a second radial distance R2 from the central reception point 10.

[0040] The second radial distance R2 defines a second cylinder C2 coaxial to the transmission axis 6.

[0041] The third photosensitive sensors 13 are configured to detect electromagnetic radiation, for example electromagnetic radiation from the laser beam of power 5 or from a further source of electromagnetic radiation, in particular to detect electromagnetic radiation from the laser beam of power 5.

[0042] The third photosensitive sensors 13 are positioned in correspondence with the receiver 4.

[0043] The third photosensitive sensors 13 are positioned around the central receiving point 10, at a third radial distance R3 from the central receiving point 10.

[0044] The third radial distance R3 defines a third cylinder C3 coaxial to the transmission axis 6.

[0045] The second radial distance R2 is greater than the first radial distance R1. Furthermore, the third radial distance R3 is greater than the second radial distance R2.

[0046] The electronic processing unit is configured to deactivate the emission of the laser beam of power 5 if the laser beam of power 5 is not detected by at least a first photosensitive sensor 11.

[0047] Furthermore, the electronic processing unit is configured to:

[0048] - detecting the entry of a foreign body into the third cylinder C3, by means of at least a third photosensitive sensor 13, in particular in correspondence with an interruption in the detection of electromagnetic radiation by at least a third photosensitive sensor 13;

[0049] - determine, by means of at least a first and / or a second and / or a third photosensitive sensor 11, 12, 13, or by means of a plurality of first and / or second and / or third photosensitive sensors 11, 12, 13, or by means of a plurality of second and / or third photosensitive sensors 12, 13, whether the foreign body is directed along a direction not incident on the second cylinder C2, and in this case not deactivate the laser beam of power 5;

[0050] - determine, by means of at least a first and / or a second and / or a third photosensitive sensor 11, 12, 13, or by means of a plurality of first and / or second and / or third photosensitive sensors 11, 12, 13, or by means of a plurality of second and / or third photosensitive sensors 12, 13, whether the foreign body is directed along a direction incident on the second cylinder C2, but not incident on the first cylinder C1, and in this case deactivate the emission of the laser beam of power 5 in the event that the presence of the foreign body is detected inside the second cylinder C2 for an uninterrupted and predetermined non-zero period of time;

[0051] - determine, by means of at least a first and / or a second and / or a third photosensitive sensor 11, 12, 13, or by means of a plurality of first and / or second and / or third photosensitive sensors 11, 12, 13, or by means of a plurality of second and / or third photosensitive sensors 12, 13, whether the foreign body is directed along a direction incident on the first cylinder C1, and in this case deactivate the emission of the laser beam of power 5 upon failure to detect the laser beam of power 5 by at least a second photosensitive sensor 12.

[0052] Advantageously, a safety system 1 configured in this way is more efficient than the known art. In particular, the safety system 1 configured in this way is equipped with a very rapid response in dangerous conditions and at the same time allows for the recognition of any cases of "false positives".

[0053] In fact, the arrangement of first, second and third photosensitive sensors 11, 12, 13 at different radial distances R1, R2, R3, allows to distinguish between critical or immediate danger conditions, which require immediate deactivation of the laser beam of power 5, alert or possible danger conditions, which do not require immediate deactivation of the laser beam of power 5, and non-dangerous or “false positive” conditions.

[0054] In particular, in the case in which a body passes through the innermost portion of the laser beam of power 5, interrupting the detection of the laser beam of power 5 by at least one first photosensitive sensor 11, the emission of the laser beam of power 5 would be immediately interrupted.In fact, in the innermost portion of the 5-watt laser beam, the electromagnetic radiation of the 5-watt laser beam has a higher intensity and can therefore be particularly dangerous, for example for a human eye.

[0055] Advantageously, the security system 1 thus configured is also more robust to false negatives, since system 1 does not rely on a single ring of sensors whose malfunction would not allow it to detect obstacles in the transmission.

[0056] The electromagnetic radiation of the laser beam of power 5 has maximum intensity in correspondence with the transmission axis 6, and decreases in a direction radially external to the transmission axis 6, for example with a Gaussian or multimode trend.

[0057] Conversely, in the event that a body passes through a peripheral portion of the laser beam, in particular inside the third cylinder C3, interrupting the detection of electromagnetic radiation by at least a third photosensitive sensor 13, the electronic processing unit is configured to distinguish three cases:

[0058] - a first case, in which the passing body is directed along a direction entering the first cylinder C1;

[0059] - a second case, in which the passing body is directed along a direction entering the second cylinder C2, but not entering the first cylinder C1;

[0060] - a third case, in which the passing body is directed along a direction not entering the second cylinder C2. In particular, this distinction is preferably effected by means of second and third photosensitive sensors 12, 13.

[0061] In the first case, the laser beam of power 5 is interrupted when the body stops detecting the electromagnetic radiation of at least a second sensor 12. In fact, this condition represents a danger since the body is directed towards the area with the highest electromagnetic density, i.e. the first cylinder C1, and therefore the most dangerous. Therefore, the laser beam of power 5 is interrupted before the body can enter the most dangerous area, the first cylinder C1, but is interrupted preventively as soon as it enters the second cylinder C2. This prevents the engagement of the internal ring, where the high-danger area is closest and therefore the risk is greater, mitigating the risk.

[0062] In the second case, the laser beam of power 5 is interrupted following a predetermined, non-zero period of time, during which the body remains or transits in the second cylinder C2, without therefore entering the first cylinder C1. In fact, the area of ​​the second cylinder C2 is potentially dangerous, for example for a human eye, only if the exposure to the electromagnetic radiation of that area persists for a certain period of time, but does not present a danger such as to require an immediate interruption of the laser beam of power 5. Consequently, the safety system 1 configured in this way avoids an unwanted interruption of the laser beam of power 5 in the event that a body passes or remains in the second cylinder C2, without entering the first cylinder C1, for a period of time shorter than the predetermined period of time, or a period of time such as not to generate danger, for example for a human eye.

[0063] Finally, in the third case, in which it is determined that the body has not entered the areas of high or potential danger, i.e. the first and second cylinders C1, C2, but is instead transiting or stationary within the area of ​​substantially zero danger, i.e. the third cylinder C3, the laser beam of power 5 is not interrupted. Consequently, the third cylinder C3 allows the presence of a foreign body to be detected in the vicinity of the laser beam of power 5, and in particular in the vicinity of the most dangerous area of ​​the laser beam of power 5, but determines an interruption of the laser beam of power 5 only in the event of real danger, avoiding an interruption in the event of a false positive.

[0064] According to one embodiment, the emitter 3 comprises a plurality of additional laser devices 14.

[0065] The additional laser devices 14 are configured to emit an additional laser beam 15 detectable by the third photosensitive sensors 13.

[0066] Specifically, the additional laser beam 15 emitted by each additional laser beam device 14 is directed against a respective third photosensitive sensor 13.

[0067] Advantageously, the additional laser beams 15 reinforce the detection of electromagnetic radiation by the third photosensitive sensors 13, by emitting further electromagnetic radiation in addition to that emitted by the laser beam of power 5, thus further reducing the risk of an unwanted interruption in the event of a false positive. In fact, the third photosensitive sensors 13 are positioned so as to detect electromagnetic radiation from the laser beam of power 5 of minimal intensity, which is difficult to detect by the third photosensitive sensors 13. The presence of the additional laser devices 14 allows the correct functioning of the third photosensitive sensors 13 to be preserved, ensuring that, in the absence of the passage of a foreign body in the laser beam of power 5, they are nevertheless constantly exposed to electromagnetic radiation.

[0068] In one embodiment, the additional laser beam 15 generated by each additional laser beam device 14 is a laser that is harmless to the eye.

[0069] Advantageously, this configuration allows to increase the efficiency of the safety system 1 while avoiding the generation of a danger, in particular for the human eye.

[0070] The additional laser devices 14 are positioned at the emitter 3.

[0071] According to one embodiment, the additional laser devices 14 are positioned around the central emission point 9, at a radial distance from the central emission point 9 equal to the third radial distance R3.

[0072] Advantageously, the additional laser devices 14 are positioned facing corresponding third photosensitive sensors 13.

[0073] According to one embodiment, the additional laser beams 15 are all parallel to each other and parallel to the transmission axis 6. Consequently, the additional laser beams 15 define and delimit the cylindrical surface of the third cylinder C3.

[0074] According to one embodiment, the additional laser devices 14 are positioned only at a radial distance from the central emission point 9 equal to the third radial distance R3 (Fig. 2). According to one embodiment, the additional laser devices 14 are positioned both at a radial distance from the central emission point 9 equal to the first radial distance R1, and at a radial distance from the central emission point 9 equal to the second radial distance R2, and at a radial distance from the central emission point 9 equal to the third radial distance R3 (Fig. 1), that is, additional laser devices 14 are present on all three circumferences defined by the first, second and third radial distances R1, R2, R3.

[0075] According to one embodiment, the safety system 1 comprises a plurality of photosensitive sensors 11, 12, 13 positioned in correspondence with the emitter 3.

[0076] In accordance with this embodiment, the safety system 1 comprises a plurality of reflectors 16 positioned at the receiver 4.

[0077] The reflectors 16 are configured to reflect the power laser beam 5 and / or the additional laser beam 15 in the direction of a respective photosensitive sensor 11, 12, 13 positioned on the emitter 3.

[0078] Advantageously, this arrangement of photosensitive sensors 11, 12, 13 also on the emitter 3 increases the efficiency of the safety system 1 and reduces the possibility of system malfunctions or detection of false positives. In fact, in the event that the photosensitive sensors positioned on the transmitter were to be subject to malfunction, detection would still be ensured by the additional photosensitive sensors present.

[0079] According to one embodiment, the reflectors 16 are positioned substantially along the same circumferences defined on the receiver 4 along which the first photosensitive sensors 11, the second photosensitive sensors 12 and the third photosensitive sensors 13 are positioned.

[0080] According to one embodiment, the reflectors 16 and the photosensitive sensors 11, 12, 13 are arranged alternately on each circumference. Thus, each reflector 16 is positioned between two adjacent photosensitive sensors 11, 12, 13, and vice versa.

[0081] According to one embodiment, the photosensitive sensors 11, 12, 13 positioned on the emitter 3 are positioned facing respective reflectors 16.

[0082] According to one embodiment, the first photosensitive sensors 11 positioned on the emitter 3 are positioned along a circumference centered at the central emission point 9 and having a radius equal to the first radial distance R1.

[0083] According to one embodiment, the second photosensitive sensors 12 positioned on the emitter 3 are positioned along a circumference centered at the central emission point 9 and having a radius equal to the second radial distance R2.

[0084] According to one embodiment, the third photosensitive sensors 13 positioned on the emitter 3 are positioned along a circumference centered at the central emission point 9 and having a radius equal to the third radial distance R3.

[0085] According to one embodiment, the photosensitive sensors 13 positioned on the emitter 3 at the radial distance R3 from the central emission point 9 are positioned adjacent to the additional laser devices 14.

[0086] According to one embodiment, the first photosensitive sensors 11 are positioned along a circumference of radius equal to the first radial distance R1, axisymmetric about the transmission axis 6.

[0087] According to one embodiment, the first radial distance R1 is between 90 mm and 80 mm, preferably it is 85 mm.

[0088] According to one embodiment, the second photosensitive sensors 12 are positioned along a circumference equal to the second radial distance radius R2, axisymmetric about the transmission axis 6.

[0089] According to one embodiment, the second radial distance R2 is between 120 mm and 100 mm, preferably it is 110 mm.

[0090] According to one embodiment, the third photosensitive sensors 13 are positioned along a circumference of radius equal to the third radial distance R3, axisymmetric about the transmission axis 6.

[0091] According to one embodiment, the third radial distance R3 is between 140 mm and 130 mm, preferably it is 135 mm.

[0092] According to one embodiment, the power laser beam 5 has a wavelength between 1,500 nm and 1,600 nm, preferably equal to 1,550 nm.

[0093] According to one embodiment, the photosensitive sensors 11, 12, 13 and / or the additional laser devices 14 are positioned at, or on, the emitting wall 7 and / or receiving wall 8.

[0094] According to a further aspect of the invention, a method for operating a safety system 1 as previously described comprises the following construction steps:

[0095] - have a safety system 1 as previously described;

[0096] - deactivate, by means of the electronic processing unit, the emission of the laser beam of power 5 in the event of failure to detect the laser beam of power 5 by at least one first photosensitive sensor 11, and / or

[0097] - detect, by means of at least a third photosensitive sensor 13, the entry of a foreign body into the third cylinder C3;

[0098] - determine, by means of at least one first or second or third photosensitive sensor 11, 12, 13, or by means of a plurality of first or second or third photosensitive sensors 11, 12, 13, whether the foreign body is directed along a direction not incident on the second cylinder C2, and in this case not deactivate the laser beam of power 5; and / or

[0099] - determine, by means of at least one first or second or third photosensitive sensor 11, 12, 13, or by means of a plurality of first or second or third photosensitive sensors 11, 12, 13, whether the foreign body is directed along a direction incident on the second cylinder C2, but not incident on the first cylinder C1, and in this case deactivate the emission of the laser beam of power 5 in the event that the presence of the foreign body is detected inside the second cylinder C2 for an uninterrupted and predetermined non-zero period of time; and / or

[00100] - determining, by means of at least a first or a second or a third photosensitive sensor 11, 12, 13, or by means of a plurality of first or second or third photosensitive sensors 11, 12, 13, whether the foreign body is directed along a direction incident on the first cylinder C1, and in this case deactivating the emission of the laser beam of power 5 upon failure to detect the laser beam of power 5 by at least a second photosensitive sensor 12.

[00101] Naturally, the person skilled in the art will be able to make modifications or adaptations to the present invention, without however departing from the scope of the claims set out below. List of references: 1. Security system 2. Wireless energy transmission system 3. Emitter 4. Receiver 5. Power laser beam 6. Drive axle 7. Emission wall 8. Reception wall 9. Central point of emission 10. Central reception point 11. First photosensitive sensor 12. Second photosensitive sensor 13. Third photosensitive sensor 14. Additional laser device 15. Additional laser beam 16. Reflector R1. First radial distance R2. Second radial distance R3. Third radial distance C1. First cylinder C2. Second cylinder C3. Third cylinder

Claims

1. A security system (1) for a wireless energy transmission system (2), said security system (1) comprising an emitter (3) and a receiver (4), wherein the emitter (3) comprises an emission wall (7) and is configured to emit a power laser beam (5) collimated by the emission wall (7) in the direction of the receiver (4), and wherein the receiver (4) comprises a reception wall (8) and is configured to receive on the reception wall (8) the power laser beam (5) emitted by the emitter (3), wherein the power laser beam (5) defines a transmission axis (6) extending between the emitter (3) and the receiver (4), and wherein the power laser beam (5) is substantially coaxial with the transmission axis (6), wherein the transmission axis (6) intersects the emission wall (7) at a central emission point (9), and intersects the reception wall (8) at a central point of reception (10),wherein the safety system (1) comprises: - an electronic processing unit; - a plurality of first photosensitive sensors (11), configured to detect the power laser beam (5), wherein the first photosensitive sensors (11) are positioned at the receiver (4), around the central reception point (10) and at a first radial distance (R1) from the central reception point (10), wherein the first radial distance (R1) defines a first cylinder (C1) coaxial to the transmission axis (6); - a plurality of second photosensitive sensors (12), configured to detect the power laser beam (5), wherein the second photosensitive sensors (12) are positioned at the receiver (4), around the central reception point (10) and at a second radial distance (R2) from the central reception point (10),wherein the second radial distance (R2) defines a second cylinder (C2) coaxial to the transmission axis (6); - a plurality of third photosensitive sensors (13), configured to detect electromagnetic radiation, wherein the third photosensitive sensors (13) are positioned in correspondence with the receiver (4), around the central reception point (10) and at a third radial distance (R3) from the central reception point (10), wherein the third radial distance (R3) defines a third cylinder (C3) coaxial to the transmission axis (6); wherein the second radial distance (R2) is greater than the first radial distance (R1), wherein the third radial distance (R3) is greater than the second radial distance (R2), wherein the electronic processing unit is configured to deactivate the emission of the power laser beam (5) upon failure to detect the power laser beam (5) by at least one first photosensitive sensor (11),and wherein the electronic processing unit is further configured to: - detect an entry of a foreign body into the third cylinder (C3), by means of at least one third photosensitive sensor (13), in correspondence with an interruption of detection of electromagnetic radiation by at least one third photosensitive sensor (13); - determine, by means of at least one first and / or one second and / or one third photosensitive sensor (11, 12, 13) whether the foreign body is directed along a direction not incident on the second cylinder (C2), and in this case not deactivate the power laser beam (5); - determine, by means of at least one first and / or one second and / or one third photosensitive sensor (11, 12, 13) whether the foreign body is directed along a direction incident on the second cylinder (C2), but not incident on the first cylinder (C1),and in this case deactivate the emission of the power laser beam (5) in the event that the presence of the foreign body is detected inside the second cylinder (C2) for an uninterrupted and predetermined period of time which is not null; - determine, by means of at least a first and / or a second and / or a third photosensitive sensor (11, 12, 13) whether the foreign body is directed along a direction incident on the first cylinder (C1), and in this case deactivate the emission of the power laser beam (5) in the event that the power laser beam (5) is not detected by at least a second photosensitive sensor (12)., 2. A safety system (1) according to claim 1, wherein the emitter (3) comprises a plurality of additional laser devices (14) configured to emit an additional laser beam (15) detectable by the third photosensitive sensors (13), preferably wherein the additional laser beam (15) emitted by each additional laser beam device (14) is directed against a respective third photosensitive sensor (13), and wherein the additional laser beam (15) generated by each additional laser beam device (14) is an eye-safe laser.

3. Safety system (1) according to claim 2, wherein the additional laser devices (14) are positioned around the central emission point (9), at a radial distance from the central emission point (9) equal to the third radial distance (R3), preferably facing corresponding third photosensitive sensors (13), and / or wherein the additional laser beams (15) are all parallel to each other and parallel to the transmission axis (6).

4. Safety system (1) according to claim 3, wherein the additional laser devices (14) are positioned only at a radial distance from the central emission point (9) equal to the third radial distance (R3), or wherein the additional laser devices (14) are positioned both at a radial distance from the central emission point (9) equal to the first radial distance (R1), and at a radial distance from the central emission point (9) equal to the second radial distance (R2), and at a radial distance from the central emission point (9) equal to the third radial distance (R3).

5. A safety system (1) according to any of the preceding claims, comprising a plurality of photosensitive sensors (11, 12, 13) positioned at the emitter (3), wherein the safety system (1) further comprises a plurality of reflectors (16) positioned at the receiver (4), wherein the reflectors (16) are configured to reflect the power laser beam (5) and / or the additional laser beam (15) in the direction of a respective photosensitive sensor (11, 12, 13) positioned at the emitter (3).

6. Security system (1) according to claim 5, wherein the reflectors (16) are positioned substantially along the same circumferences defined on the receiver (4) along which the first photosensitive sensors (11), the second photosensitive sensors (12) and the third photosensitive sensors (13) are positioned.

7. Safety system (1) according to claim 5 or 6, wherein the reflectors (16) and the photosensitive sensors (11, 12, 13) are arranged alternately on each circumference.

8. Security system (1) according to one of claims 5 to 7, wherein the first photosensitive sensors (11) positioned on the emitter (3) are positioned along a circumference centred on the central emission point (9) and having a radius equal to the first radial distance (R1), and / or wherein the second photosensitive sensors (12) positioned on the emitter (3) are positioned along a circumference centred on the central emission point (9) and having a radius equal to the second radial distance (R2), and / or wherein the third photosensitive sensors (13) positioned on the emitter (3) are positioned along a circumference centred on the central emission point (9) and having a radius equal to the third radial distance (R3).

9. Security system (1) according to any of the preceding claims, wherein the photosensitive sensors (13) positioned on the emitter (3) at the radial distance (R3) from the central emission point (9) are positioned adjacent to additional laser devices (14), and / or wherein the first radial distance (R1) is between 90 mm and 80 mm, preferably is 85 mm, and / or wherein the second radial distance (R2) is between 120 mm and 100 mm, preferably is 110 mm, and / or wherein the third radial distance (R3) is between 140 mm and 130 mm, preferably is 135 mm, and / or wherein the power laser beam (5) has a wavelength between 1,500 nm and 1,600 nm, preferably is 1,550 nm.

10. A method for operating a safety system (1) according to any of the preceding claims comprises the following construction steps: - providing a safety system (1) according to any of the preceding claims; - deactivating, by means of the electronic processing unit, the emission of the power laser beam (5) upon failure to detect the power laser beam (5) by at least one first photosensitive sensor (11), and / or - detecting, by means of at least one third photosensitive sensor (13), an entry of a foreign body into the third cylinder (C3); - determining, by means of at least one first or a second or a third photosensitive sensor (11, 12, 13), or by means of a plurality of first or second or third photosensitive sensors (11, 12, 13), whether the foreign body is directed along a direction not incident on the second cylinder (C2), and in that case not deactivating the power laser beam (5);and / or - determine, by means of at least a first or a second or a third photosensitive sensor (11, 12, 13), or by means of a plurality of first or second or third photosensitive sensors (11, 12, 13), whether the foreign body is directed along a direction incident on the second cylinder (C2), but not incident on the first cylinder (C1), and in this case deactivate the emission of the power laser beam (5) in the event that the presence of the foreign body is detected inside the second cylinder (C2) for an uninterrupted and predetermined non-zero period of time;and / or - determine, by means of at least a first or a second or a third photosensitive sensor (11, 12, 13), or by means of a plurality of first or second or third photosensitive sensors (11, 12, 13), whether the foreign body is directed along a direction incident on the first cylinder (C1), and in this case deactivate the emission of the power laser beam (5) upon failure to detect the power laser beam (5) by at least a second photosensitive sensor (12).;