SECURITY SYSTEM FOR A WIRELESS POWER TRANSMISSION SYSTEM

Description

“Security system for a wireless power transmission system”

[0001] Field of invention

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

[0003] State of the art

[0004] Wireless energy transfer technology involves the use of a system for transmitting and receiving a laser beam to achieve a transmission of electricity over long distances without the need for physical connections, such as pylons and wiring.

[0005] In particular, the power 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 comprises inside it an energy conversion element, for example an element photovoltaic, for the conversion of the radiant energy of the laser beam into electrical energy.

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

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

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

[0009] Solution

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

[0011] A further particular object of the present invention is to provide provision of a security system for a wireless energy transmission system, in particular for the transmission of energy via a laser beam, equipped with a high rapid response in dangerous conditions and which at the same time presents costs and complexity reduced construction costs.

[0012] These and other purposes are achieved by means of a security system for a wireless power transmission system, especially for power transmission by means of a laser beam, according to independent claim 1.

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

[0014] Figure

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

[0016] – Figure 1 is a front view of a security system emitter, 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 security system receiver, 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 an 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 security system is generally referred to as with reference number 1.

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

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

[0025] The emitter 3 comprises an emitting 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 emitting wall 7 in direction of the receiver 4.

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

[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 wall of reception 8.

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

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

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

[0031] The safety system 1 comprises an electronic processing unit, a 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 at the receiver 4.

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

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

[0036] “Radial distance” refers to the distance measured in the direction radial 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 at the receiver 4.

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

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

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

[0042] The third photosensitive sensors 13 are positioned at the receiver 4.

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

[0044] The third radial distance R3 defines a third cylinder C3 coaxial to the axis of transmission 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 disable the emission of the laser beam of power 5 when the laser beam of power 5 is not detected by of at least one first photosensitive sensor 11.

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

[0048] – detect the entry of a foreign body into the third cylinder C3, by means of at least a third photosensitive sensor 13, in particular at an interruption in the detection of electromagnetic radiation by at least one 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 a plurality of second and / or third photosensitive sensors 12, 13, if the foreign body is directed along a non-direction accident to the second cylinder C2, and in that case do 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 a plurality of second and / or third photosensitive sensors 12, 13, if the foreign body is directed along an incident direction to the second cylinder C2, but does not affect the first cylinder C1, and in that case deactivate the emission of the laser beam of power 5 in case the presence of the body is detected foreign inside the second cylinder C2 for an uninterrupted period of time and predetermined not null;

[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 a plurality of second and / or third photosensitive sensors 12, 13, if the foreign body is directed along an incident direction to the first cylinder C1, and in this case deactivate the emission of the laser beam of power 5 to failure to detect the 5 power laser beam for at least one second photosensitive sensor 12.

[0052] Advantageously, a security system 1 configured in this way is more efficient than the known art. In particular, the safety system 1 so configured is equipped with a high rapid response in dangerous conditions and at at the same time it allows us to recognise 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 conditions or of immediate danger, requiring immediate deactivation of the laser beam power 5, conditions of alert or possible danger, which do not require immediate deactivation of the 5 power laser beam, and non-dangerous or “false positive” conditions.

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

[0055] Advantageously, the safety system 1 configured in this way is more robust even to false negatives, since System 1 does not rely on a single sensor ring whose malfunction would not allow the detection of obstacles in the transmission.

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

[0057] Conversely, in the case in which a body passes through a peripheral portion of the beam laser, particularly inside the third cylinder C3, interrupting the detection of electromagnetic radiation from at least one third photosensitive sensor 13, the unit electronic processing 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 non-directional entering the second cylinder C2. In particular, this distinction is preferably can be performed by means of second and third photosensitive sensors 12, 13.

[0061] In the first case, the laser beam of power 5 is interrupted at the moment in which the body interrupts the detection of electromagnetic radiation for at least one second sensor 12. In fact, this condition represents a danger since the body is directed towards the area with the highest electromagnetic density, that is the first cylinder C1, and therefore more dangerous. Therefore, the 5 power laser beam is interrupted before the body can enter the most dangerous area, the first cylinder C1, but it is interrupted in advance upon entry into the second cylinder C2. This prevents the engagement of the inner ring, where the high-danger zone 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 stationary or in transit 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 exposure to electromagnetic radiation from that area persists for a certain period of time period of time, but does not present a danger sufficient to require an interruption immediate release of the 5 power laser beam. Consequently, the safety system 1 so configured prevents unwanted interruption of the 5 power laser beam in case a body transits or stops in the second cylinder C2, without entering the first cylinder C1, for a period of time less than the predetermined period of time, i.e. a period of a time that does not generate danger, for example to a human eye.

[0063] Finally, in the third case, where it is determined that the body did not enter the high or potential danger areas, i.e. the first and second cylinders C1, C2, but is instead transiting or stationary within the substantially dangerous area nothing, that is, the third cylinder C3, the laser beam of power 5 is not interrupted. consequently, the third cylinder C3 allows the detection of the presence of a foreign body in the vicinity of the 5 power laser beam, and in particular in the vicinity of the area more dangerous than the 5 power laser beam, but can cause an interruption of the 5 power laser beam only in case of real danger, avoiding an interruption in false positive case.

[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 a laser beam additional 15 detectable by third photosensitive sensors 13.

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

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

[0068] According to 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 hazard, in particular to the human eye.

[0070] The additional laser devices 14 are positioned at of 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 point emission center 9 equal to the third radial distance R3.

[0072] Advantageously, the additional laser devices 14 are positioned facing each other to 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 laser beams additional 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 laser devices additional 14 are positioned both at a radial distance from the central point of emission 9 equal to the first radial distance R1, either at a radial distance from the point emission center 9 equal to the second radial distance R2, both at a radial distance from the central emission point 9 equal to the third radial distance R3 (fig. 1), or they are 14 additional laser devices are present on all three circumferences defined by the first, second and third radial distance R1, R2, R3.

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

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

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

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

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

[0080] According to one embodiment, the reflectors 16 and the photosensitive sensors 11, 12, 13 are arranged alternately on each circumference. Therefore, 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 emitter 3 are positioned along a circumference centered at the central point of emission 9 and having 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 point emitting center 9 and having radius equal to the second radial distance R2.

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

[0085] According to one embodiment, the photosensitive sensors 13 positioned on emitter 3 at 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 around the transmission axis 6.

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

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

[0089] According to one embodiment, the second radial distance R2 is between 120 mm and 100 mm, preferably 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 around the transmission axis 6.

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

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

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

[0094] According to a further aspect of the invention, a method for actuating a security system 1 as previously described, comprises the following phases realizations:

[0095] – have a security system 1 as previously described;

[0096] – deactivate, by means of the electronic processing unit, the emission of the laser beam of power 5 when the laser beam of power 5 is not detected by of at least one first photosensitive sensor 11, and / or

[0097] – detect, by means of at least a third photosensitive sensor 13, an input of a foreign body in the third cylinder C3;

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

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

[00100] – determine, by means of at least a first or a second or a third sensor photosensitive 11, 12, 13, or by means of a plurality of first or second or third sensors photosensitive 11, 12, 13, if 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 to failure to detect the 5 power laser beam for at least one second photosensitive sensor 12.

[00101] Of course, the person who is expert in the field will be able to contribute modifications or adaptations to the present invention, without however departing from the scope of the claims reported 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).;