Laser projector and laser transmission cable thereof

Abstract

Provided in the present invention are a laser transmission cable and a laser projector thereof. The laser transmission cable comprises at least one first optical fiber, one second optical fiber, one optical signal transmitting apparatus and one optical signal receiving apparatus. The first optical fiber is configured to receive laser from a laser light source and transmit the laser. The second optical fiber is arranged in parallel with the first optical fiber and is provided with a first end and a second end which are opposite to each other. The optical signal transmitting apparatus is arranged at the first end of the second optical fiber and is configured to input a monitoring signal to the second optical fiber. The optical signal receiving apparatus is arranged at the second end of the second optical fiber and is configured to receive the monitoring signal. The optical signal receiving apparatus is coupled with a switch, and the switch is arranged in a power supply circuit connected to the laser light source. When the optical signal receiving apparatus fails to receive the monitoring signal, the optical signal receiving apparatus is configured to drive the switch to form an open circuit.

Description

Laser projector and laser transmission cable Technical Field

[0001] The present disclosure relates to a laser projector and a laser transmission cable thereof. Background Art

[0002] Optical fibers can be used for laser transmission. However, optical fibers are easily damaged. For example, they may break due to excessive bending or frequent bending. When an optical fiber is damaged, laser energy can overflow from the damaged part of the optical fiber and heat the surrounding objects, which may be dangerous. Therefore, a mechanism for detecting optical fiber damage is needed. The current industry practice is to use a linear heat detection cable (LHDC) to detect optical fiber damage. The linear heat detection cable has the characteristic of short-circuiting when the temperature reaches a certain upper limit. Therefore, the optical fiber damage can be detected by detecting the short-circuit of the linear heat detection cable. However, the linear heat detection cable has many disadvantages, such as: (1) high price, (2) thick outer diameter and hard material, which makes it difficult to thread the cable and may damage the optical fiber during threading, and (3) it is made of metal material and is therefore heavy. Therefore, there is a need to develop new technologies for detecting optical fiber damage.

[0003] Summary of the Invention

[0004] In view of this, an object of the present disclosure is to provide an improved laser projector and a laser transmission cable thereof to solve the above-mentioned problems of the prior art.

[0005] To achieve the above-mentioned objectives, according to some embodiments of the present disclosure, a laser transmission cable includes at least a first optical fiber, a second optical fiber, an optical signal transmitting device, and an optical signal receiving device. The first optical fiber is configured to receive laser light from a laser light source and is configured to transmit laser light. The second optical fiber is arranged in parallel with the first optical fiber and has a first end and a second end relative to each other. The optical signal transmitting device is arranged at the first end of the second optical fiber and is configured to input a monitoring signal to the second optical fiber. The optical signal receiving device is arranged at the second end of the second optical fiber and is configured to receive a monitoring signal. The optical signal receiving device is coupled to a switch, and the switch is arranged in a power supply circuit connected to the laser light source. When the optical signal receiving device does not receive the monitoring signal, the optical signal receiving device is configured to drive the switch to form an open circuit.

[0006] In one or more embodiments of the present disclosure, the first optical fiber comprises a glass optical fiber, and the second optical fiber comprises a plastic optical fiber.

[0007] In one or more embodiments of the present disclosure, the laser transmission cable further includes a limiting sleeve, which is sleeved outside the first optical fiber and the second optical fiber.

[0008] In one or more embodiments of the present disclosure, the limiting sleeve is heat-resistant to at least one hundred and twenty degrees Celsius.

[0009] In one or more embodiments of the present disclosure, the limiting sleeve has a smooth inner surface.

[0010] In one or more embodiments of the present disclosure, the laser transmission cable further includes a metal hose sleeved outside the limiting sleeve.

[0011] In one or more embodiments of the present disclosure, the optical signal transmitting device includes a pulse generator and an optical transmitter. The pulse generator is configured to generate a pulse signal. The optical transmitter is electrically connected to the pulse generator and configured to transmit a monitoring signal according to the pulse signal.

[0012] In one or more embodiments of the present disclosure, an optical signal receiving device includes a pulse detector and an optical receiver. The optical receiver is configured to generate a light response signal. The pulse detector is electrically connected to the optical receiver and configured to output a detection signal based on the light response signal, the detection signal indicating whether the optical receiver has received a monitoring signal. A switch is coupled to the pulse detector and configured to switch state based on the detection signal.

[0013] In one or more embodiments of the present disclosure, the laser transmission cable further includes a first connector and a second connector. The first connector includes a first housing, and the second connector includes a second housing. The first and second housings enclose opposite ends of the first optical fiber. The optical signal transmitting device includes a first circuit board assembly disposed in the first housing, the first circuit board assembly including a first circuit board, a pulse generator disposed on the first circuit board, and an optical transmitter. The optical signal receiving device includes a second circuit board assembly disposed in the second housing, the second circuit board assembly including a second circuit board, a pulse detector disposed on the second circuit board, and an optical receiver.

[0014] According to some embodiments of the present disclosure, a laser projector includes a light source system, an image projection component, and the above-mentioned laser transmission cable. The laser transmission cable further includes a first connector and a second connector, wherein opposite ends of a first optical fiber are respectively covered by the first connector and the second connector, and an optical signal transmitting device and an optical signal receiving device are respectively disposed in the first connector and the second connector. The light source system includes a laser light source and a switch, wherein the second connector of the laser transmission cable is connected to the light source system. The image projection component is movably connected to the light source system via the laser transmission cable. The first connector of the laser transmission cable is connected to the image projection component.

[0015] In summary, the laser transmission cable disclosed herein is provided with an additional optical fiber, which is arranged in parallel with one or more optical fibers used to transmit laser light, and is used to transmit monitoring signals. When the optical fiber used to transmit laser light is damaged, the laser energy will overflow from the damaged area and burn the optical fiber used to transmit the monitoring signal, causing the transmission of the monitoring signal to be interrupted. At this time, the optical signal receiving device used to receive the monitoring signal detects the interruption of the monitoring signal transmission, and drives a switch provided in the power supply circuit of the laser light source to form a short circuit, so that the laser light source is automatically shut down to avoid danger. In some embodiments, the optical fiber for transmitting the monitoring signal can use plastic optical fiber, which has the characteristics of light weight, flexibility, and low temperature resistance, and is cheap, making the manufacture and use of the laser transmission cable more convenient, and the production cost of the laser transmission cable can also be lowered. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] To make it more clear and easy to understand, the attached drawings are described as follows:

[0017] FIG1 is a schematic diagram illustrating a laser projector according to an embodiment of the present disclosure.

[0018] FIG. 2 is an enlarged view showing a laser transmission cable of the laser projector shown in FIG. 1 .

[0019] FIG. 3 is a functional block diagram illustrating the laser projector shown in FIG. 1 .

[0020] FIG. 4 is a perspective exploded view showing a first connector of the laser transmission cable shown in FIG. 2 .

[0021] FIG. 5 is a perspective exploded view showing a second connector of the laser transmission cable shown in FIG. 2 .

[0022] FIG. 6 is a schematic top view showing a laser transmission cable according to another embodiment of the present disclosure.

[0023] FIG. 7 is a schematic cross-sectional view of the laser transmission cable shown in FIG. 6 at a line segment 7 - 7 ′.

[0024] FIG. 8 is a schematic top view showing a laser transmission cable according to another embodiment of the present disclosure.

[0025] The figures are marked as follows: 12: laser projector 21: light source system 22: image projection component 23: laser light source 28: power supply circuit 29: switch 30, 40, 80: laser transmission cable 31: first connector 32, 32A, 32B: second connector 33: output port 34: input port 35: metal hose 36: first shell 37: second shell 48: limiting sleeve 49: internal channel 51, 51A, 51B: first optical fiber 52, 52A, 52B: second optical fiber 53: first end 54: second end 60, 60': optical signal transmitting device 63: pulse generator 65: optical transmitter 67: circuit board 70, 70A, 70B: optical signal receiving device 73: pulse detector 75: optical receiver 77: circuit board 90: power supply 96: monitoring signal 97: laser DETAILED DESCRIPTION

[0026] For a more detailed and complete description of the present disclosure, reference is made to the accompanying drawings and the various embodiments described below. The elements in the drawings are not drawn to scale and are provided solely for the purpose of illustrating the present disclosure. Numerous practical details are described below to provide a comprehensive understanding of the present disclosure. However, those skilled in the relevant art will appreciate that the present disclosure may be practiced without one or more of these practical details, and therefore, these details should not be construed as limiting the present disclosure.

[0027] Please refer to Figure 1. Figure 1 is a schematic diagram of a laser projector 12 according to an embodiment of the present disclosure. The laser projector 12 includes at least one light source system 21, at least one image projection component 22, and at least one laser transmission cable 30. The laser projector 12 adopts a design in which the light source system 21 and the image projection component 22 (or called a projection head) are separated, and the light source system 21 and the image projection component 22 are connected by a laser transmission cable 30. Specifically, the light source system 21 is configured to provide laser light, and the image projection component 22 is movably connected to the light source system 21 through the laser transmission cable 30, and is configured to use the laser light provided by the light source system 21 to project an image. The laser transmission cable 30 is configured to transmit the laser light provided by the light source system 21 from the light source system 21 to the image projection component 22. The laser transmission cable 30 is a flexible cable to facilitate placing the image projection component 22 in a suitable position for projection.

[0028] As shown in FIG1 , the laser transmission cable 30 includes a first connector 31 and a second connector 32. The first connector 31 and the second connector 32 are disposed at opposite ends of the laser transmission cable 30 and are configured to connect to the image projection component 22 and the light source system 21, respectively. For example, the image projection component 22 and the light source system 21 may have slots for connecting to the laser transmission cable 30, and the first connector 31 and the second connector 32 may be inserted into the slots of the image projection component 22 and the light source system 21, respectively.

[0029] As shown in FIG1 , the light source system 21 includes a laser light source 23 configured to generate laser light and transmit the generated laser light to a laser transmission cable 30 via a second connector 32 . Specifically, the laser light source 23 is configured to generate high-energy laser light that can be used to project an image. The laser transmission cable 30 may include one or more optical fibers for transmitting the laser light. The optical fibers of the laser transmission cable 30 will be described further below.

[0030] As shown in FIG1 , the light source system 21 is connected to a power supply 90 configured to power the laser light source 23 and other electrical components of the light source system 21. In some embodiments, the laser light source 23 comprises at least one laser diode. In some embodiments, the light source system 21 may further include one or more optical elements (not shown, such as lenses, reflectors, and beam splitters) for directing the laser light generated by the laser light source 23 to the laser transmission cable 30.

[0031] In the embodiment shown in FIG1 , the light source system 21 and the image projection component 22 are configured one-to-one, meaning a single light source system 21 provides laser light to a single image projection component 22. However, laser projectors are not limited to a one-to-one configuration. For example, the light source system 21 and the image projection component 22 may also be configured one-to-many, meaning a single light source system 21 provides laser light to multiple image projection components 22. Alternatively, the light source system 21 and the image projection component 22 may be configured many-to-one, meaning multiple light source systems 21 provide laser light to a single image projection component 22.

[0032] Please refer to Figure 2. Figure 2 is an enlarged view of the laser transmission cable 30 of the laser projector shown in Figure 1, in which the internal structure is represented by dotted lines. Specifically, the laser transmission cable 30 includes at least one first optical fiber 51, the first optical fiber 51 extends from the first connector 31 to the second connector 32, and the two ends of the first optical fiber 51 are respectively covered by the first connector 31 and the second connector 32. The first optical fiber 51 is configured to receive laser light from the laser light source 23 of the light source system 21 (see Figure 1) and is configured to transmit laser light. In some embodiments, the laser transmission cable 30 includes a plurality of first optical fibers 51, and the ends of the plurality of first optical fibers 51 can be fused and fixed to each other to form a fiber bundle.

[0033] As shown in FIG2 , the laser transmission cable 30 further includes at least one second optical fiber 52. The second optical fiber 52 extends from the first connector 31 to the second connector 32 and is arranged in parallel with the first optical fiber 51. The second optical fiber 52 can be arranged on one side of the first optical fiber 51. Alternatively, when the laser transmission cable 30 includes multiple first optical fibers 51 forming an optical fiber bundle, the second optical fiber 52 can be arranged on one side of the optical fiber bundle or within the optical fiber bundle.

[0034] As shown in FIG. 2 , in some embodiments, the laser transmission cable 30 further includes a metal hose 35 . The metal hose 35 is sleeved outside the first optical fiber 51 and the second optical fiber 52 to provide protection for the first optical fiber 51 and the second optical fiber 52 .

[0035] Please also refer to Figure 3, which is a functional block diagram of the laser projector 12 shown in Figure 1. As shown in Figures 2 and 3, the light source system 21 further includes a power supply circuit 28 and a switch 29. The power supply circuit 28 connects the laser light source 23 and a power supply 90. The power supply 90 can supply power to the laser light source 23 via the power supply circuit 28. The switch 29 is disposed in the power supply circuit 28 and can be switched between an off state and an on state. When the switch 29 is in the off state, the power supply 90 does not supply power to the laser light source 23. When the switch 29 is in the on state, the power supply 90 is configured to supply power to the laser light source 23.

[0036] As shown in Figures 2 and 3, the laser transmission cable 30 further includes an optical signal transmitter 60 and an optical signal receiver 70. The second optical fiber 52 has a first end 53 and a second end 54, opposite each other. The optical signal transmitter 60 and the optical signal receiver 70 are disposed at the first end 53 and the second end 54 of the second optical fiber 52, respectively. The optical signal transmitter 60 is configured to input a monitoring signal 96 (indicated by an arrow) into the second optical fiber 52. The monitoring signal 96 is an optical signal configured to be transmitted through the second optical fiber 52. When the monitoring signal 96 reaches the second end 54, it is received by the optical signal receiver 70. The optical signal receiver 70 is coupled to the switch 29. When the optical signal receiver 70 does not receive the monitoring signal 96, the optical signal receiver 70 is configured to activate the switch 29 to open a circuit.

[0037] With the above configuration, if the first optical fiber 51 used to transmit laser light 97 (indicated by an arrow) is damaged, laser energy will leak out of the damaged area and burn the second optical fiber 52 located next to the first optical fiber 51 and used to transmit the monitoring signal 96, causing the transmission of the monitoring signal 96 to be interrupted. At this time, the optical signal receiving device 70 detects the interruption in the transmission of the monitoring signal 96 and activates the switch 29 provided in the power supply circuit 28 of the laser light source 23 to open the circuit, automatically disconnecting the laser light source 23 and shutting it down, thus preventing any danger.

[0038] As shown in Figures 2 and 3, in some embodiments, the optical signal transmitting device 60 and the optical signal receiving device 70 are respectively disposed in the first connector 31 and the second connector 32. When the second connector 32 is connected to the light source system 21, the optical signal receiving device 70 disposed in the second connector 32 can be coupled to the switch 29 of the light source system 21 (for example, by electrically connecting the electrical contacts disposed on the second connector 32 to corresponding electrical contacts disposed in the slot of the light source system 21), so that the optical signal receiving device 70 can drive the switch 29 to switch to the off state at the appropriate time. In addition, when the second connector 32 is connected to the light source system 21, the power supply 90 can also power the optical signal receiving device 70.

[0039] In some embodiments, the first optical fiber 51 comprises a glass optical fiber. In some embodiments, the second optical fiber 52 comprises a plastic optical fiber. Compared to LHDC (Low-Heavy Duct) used in cables currently on the market, plastic optical fiber has the following advantages: (1) low price, approximately one-seventh the price of LHDC; (2) relatively soft and flexible, which is less likely to damage the first optical fiber 51 during threading (e.g., threading the plastic optical fiber into the metal hose 35), thereby improving production yield; (3) light weight, approximately one-fifth the weight of LHDC. However, the second optical fiber 52 is not limited to a plastic optical fiber; in other embodiments, the second optical fiber 52 may comprise a glass optical fiber.

[0040] As shown in Figures 2 and 3, in some embodiments, the optical signal transmitting device 60 includes a pulse generator 63 and a light emitter 65. The pulse generator 63 is configured to generate a pulse signal (e.g., a pulsed current). The light emitter 65 is electrically connected to the pulse generator 63 and configured to receive the pulse signal. The light emitter 65 is also configured to transmit a monitoring signal 96 based on the pulse signal. Therefore, in this embodiment, the monitoring signal 96 is a pulsed light signal. In some embodiments, the light emitter 65 may include a light emitting diode (LED) or a laser diode.

[0041] It should be noted that the optical transmitter 65 is only used to send the monitoring signal 96 , so the energy of the light emitted by the optical transmitter 65 is less than the energy of the laser 97 emitted by the laser light source 23 . In other words, the energy transmitted by the second optical fiber 52 is less than the energy transmitted by the first optical fiber 51 .

[0042] As shown in Figures 2 and 3, in some embodiments, the optical signal receiving device 70 includes a pulse detector 73 and an optical receiver 75. The optical receiver 75 is configured to generate a light response signal upon receiving light of a specific wavelength (e.g., the wavelength of the monitoring signal 96). The pulse detector 73 is electrically connected to the optical receiver 75 and configured to receive the light response signal. The pulse detector 73 is also configured to output a detection signal based on the light response signal. The detection signal indicates whether the optical receiver 75 has received the monitoring signal 96. The switch 29 is coupled to the pulse detector 73 and configured to switch state based on the detection signal provided by the pulse detector 73. Specifically, when the detection signal indicates that the optical receiver 75 has received the monitoring signal 96, the switch 29 remains in the on state. Conversely, when the detection signal indicates that the optical receiver 75 has not received the monitoring signal 96, the switch 29 switches to the off state, thereby de-energizing the laser light source 23. In some embodiments, the optical receiver 75 may include a photodiode.

[0043] Please refer to Figure 4. Figure 4 is a perspective exploded view of the first connector 31 of the laser transmission cable 30 shown in Figure 2. In some embodiments, the optical signal transmitting device 60 can be implemented as a circuit board assembly and mounted in the first connector 31. In some embodiments, the first connector 31 includes a first housing 36. The optical signal transmitting device 60 includes a first circuit board assembly disposed in the first housing 36. The first circuit board assembly includes a first circuit board 67, and a pulse generator 63 and a light emitter 65 disposed on the first circuit board 67. The pulse generator 63 and the light emitter 65 can be electrically connected to each other via conductive traces disposed on or within the first circuit board 67.

[0044] As shown in FIG4 , the end of the first optical fiber 51 (only a portion is shown) is enclosed by the first housing 36 . Specifically, the first optical fiber 51 extends into the interior of the first housing 36 and passes through one side of the optical signal transmitting device 60 . The first optical fiber 51 is connected to the output port 33 of the first housing 36 to output laser light through the output port 33 .

[0045] Please refer to Figure 5. Figure 5 is a perspective exploded view of the second connector 32 of the laser transmission cable 30 shown in Figure 2. In some embodiments, the optical signal receiving device 70 can be implemented as a circuit board assembly and mounted in the second connector 32. In some embodiments, the second connector 32 includes a second housing 37. The optical signal receiving device 70 includes a second circuit board assembly disposed in the second housing 37. The second circuit board assembly includes a second circuit board 77, a pulse detector 73, and a light receiver 75 disposed on the second circuit board 77. The pulse detector 73 and the light receiver 75 can be electrically connected to each other via conductive traces disposed on or within the second circuit board 77.

[0046] As shown in FIG5 , the end of the first optical fiber 51 (only a portion is shown) is enclosed by the second housing 37. That is, the first optical fiber 51 extends into the interior of the second housing 37 and passes through one side of the optical signal receiving device 70. The first optical fiber 51 is connected to the input port 34 of the second housing 37 to receive laser light through the input port 34.

[0047] Please refer to Figures 6 and 7. Figure 6 is a schematic top view of a laser transmission cable 40 according to another embodiment of the present disclosure, wherein the internal structure is indicated by dashed lines. Figure 7 is a schematic cross-sectional view of the laser transmission cable 40 shown in Figure 6 at the line segment 7-7'. Compared to the previous embodiment, the laser transmission cable 40 of this embodiment further includes a limiting sleeve 48, which is disposed over the first optical fiber 51 and the second optical fiber 52. The limiting sleeve 48 has an internal channel 49, through which the first optical fiber 51 and the second optical fiber 52 extend.

[0048] The limiting sleeve 48 limits the distance between the first optical fiber 51 and the second optical fiber 52, ensuring that the first and second optical fibers 51, 52 are sufficiently close to each other so that, if the first optical fiber 51 transmitting the laser is damaged, the second optical fiber 52 can be promptly burned out, triggering the protection mechanism (i.e., the aforementioned step of shutting off the laser light source 23). When the first and second optical fibers 51, 52 are enclosed by the limiting sleeve 48, the distance between them is limited to not exceed the diameter of the internal channel 49 of the limiting sleeve 48. The limiting sleeve 48 is flexible, facilitating bending of the laser transmission cable 40.

[0049] In some embodiments, the limiting sleeve 48 is heat-resistant to at least 120 degrees Celsius (e.g., the limiting sleeve 48 does not melt or burn below 120 degrees Celsius). In addition to its limiting function, the limiting sleeve 48 can also prevent laser energy from escaping from the first optical fiber 51 if the first optical fiber 51 is damaged, thereby preventing objects near the laser transmission cable 40 from being heated and causing burns or even fire. In some embodiments, the limiting sleeve 48 comprises polytetrafluoroethylene (PTFE).

[0050] In some embodiments, the limiting sleeve 48 has a smooth inner surface (that is, the inner surface of the limiting sleeve 48 has a low friction coefficient), so that the first optical fiber 51 and the second optical fiber 52 can smoothly penetrate into the limiting sleeve 48 .

[0051] As shown in Figures 6 and 7, in some embodiments, the laser transmission cable 40 further includes a metal hose 35 sheathed over a limiting sleeve 48. Specifically, the limiting sleeve 48 is located between the metal hose 35 and the first optical fiber 51 and the second optical fiber 52. The metal hose 35 can protect the limiting sleeve 48 and prevent it from being worn.

[0052] Please refer to Figure 8. Figure 8 is a schematic top view of a laser transmission cable 80 according to another embodiment of the present disclosure, wherein the internal structure is represented by dashed lines. The laser transmission cable 80 of this embodiment is a Y-shaped cable suitable for a two-to-one laser projector, that is, a laser projector designed with two light source systems providing laser light to a single image projection component. The laser transmission cable 80 includes a first connector 31 and two second connectors 32A and 32B. The first connector 31 is configured to connect to an image projection component (such as the aforementioned image projection component 22), while the two second connectors 32A and 32B are each configured to connect to a light source system (such as the aforementioned light source system 21).

[0053] As shown in FIG8 , the laser transmission cable 80 further includes at least one first optical fiber 51A and at least one first optical fiber 51B, wherein the first optical fiber 51A extends from the first connector 31 to the second connector 32A to transmit laser light from one of the light source systems to the image projection component, and the first optical fiber 51B extends from the first connector 31 to the second connector 32B to transmit laser light from the other light source system to the image projection component. The laser transmission cable 80 further includes at least one second optical fiber 52A and at least one second optical fiber 52B, wherein the second optical fiber 52A extends from the first connector 31 to the second connector 32A to transmit a monitoring signal from the first connector 31 to the second connector 32A, and the second optical fiber 52B extends from the first connector 31 to the second connector 32B to transmit a monitoring signal from the first connector 31 to the second connector 32B.

[0054] As shown in FIG8 , the laser transmission cable 80 further includes an optical signal transmitter 60 ′ and two optical signal receivers 70A and 70B. The optical signal transmitter 60 ′ is disposed in the first connector 31 , while the two optical signal receivers 70A and 70B are disposed in the two second connectors 32A and 32B, respectively. In some embodiments, the optical signal transmitter 60 ′ may include two optical transmitters, each of which is connected to the two second optical fibers 52A and 52B and configured to input monitoring signals to the second optical fibers 52A and 52B, respectively.

[0055] In summary, the laser transmission cable disclosed herein is provided with an additional optical fiber, which is arranged in parallel with one or more optical fibers used to transmit laser light, and is used to transmit monitoring signals. When the optical fiber used to transmit laser light is damaged, the laser energy will overflow from the damaged area and burn the optical fiber used to transmit the monitoring signal, causing the transmission of the monitoring signal to be interrupted. At this time, the optical signal receiving device used to receive the monitoring signal detects the interruption of the monitoring signal transmission, and drives a switch provided in the power supply circuit of the laser light source to form a short circuit, so that the laser light source is automatically shut down to avoid danger. In some embodiments, the optical fiber for transmitting the monitoring signal can use plastic optical fiber, which has the characteristics of light weight, flexibility, and low temperature resistance, and is cheap, making the manufacture and use of the laser transmission cable more convenient, and the production cost of the laser transmission cable can also be lowered.

[0056] Although the present disclosure has been disclosed in the form of embodiments as described above, it is not intended to limit the present disclosure. Those skilled in the art may make various changes and modifications without departing from the spirit and scope of the present disclosure. Therefore, the scope of protection of the present disclosure shall be determined by the appended claims.

Claims

1. A laser transmission cable comprising: at least one first optical fiber configured to receive a laser from a laser light source and configured to transmit the laser; a second optical fiber, disposed in parallel with the at least one first optical fiber, and having a first end and a second end opposite to each other; an optical signal transmitting device, disposed at the first end of the second optical fiber and configured to input a monitoring signal to the second optical fiber; and An optical signal receiving device is disposed at the second end of the second optical fiber and is configured to receive the monitoring signal, wherein the optical signal receiving device is coupled to a switch, which is disposed in a power supply circuit connected to the laser light source. When the optical signal receiving device does not receive the monitoring signal, the optical signal receiving device is configured to drive the switch to form an open circuit.

2. The laser transmission cable as claimed in claim 1, wherein the at least one first optical fiber comprises at least one glass optical fiber, and the second optical fiber comprises a plastic optical fiber. 3 . The laser transmission cable as claimed in claim 1 , further comprising a limiting sleeve, wherein the limiting sleeve is sleeved outside the at least one first optical fiber and the second optical fiber. 4 . The laser transmission cable as claimed in claim 3 , wherein the limiting sleeve is heat-resistant at least 120 degrees Celsius. The laser transmission cable as claimed in claim 3 , wherein the limiting sleeve has a smooth inner surface. 6 . The laser transmission cable as claimed in claim 3 , further comprising a metal hose, wherein the metal hose is sleeved outside the limiting sleeve.

7. The laser transmission cable as claimed in claim 1, wherein the optical signal transmitting device comprises a pulse generator and an optical transmitter, the pulse generator is configured to generate a pulse signal, and the optical transmitter is electrically connected to the pulse generator and configured to transmit the monitoring signal according to the pulse signal.

8. The laser transmission cable of claim 7 , wherein the optical signal receiving device comprises a pulse detector and an optical receiver, the optical receiver being configured to generate a light response signal, the pulse detector being electrically connected to the optical receiver and being configured to output a detection signal based on the light response signal, the detection signal indicating whether the optical receiver has received the monitoring signal, wherein the switch is coupled to the pulse detector and being configured to switch a state based on the detection signal.

9. The laser transmission cable as described in claim 8 further comprises a first connector and a second connector, the first connector comprising a first housing, the second connector comprising a second housing, the opposite ends of the at least one first optical fiber being respectively covered by the first housing and the second housing, wherein the optical signal transmitting device comprises a first circuit board assembly disposed in the first housing, the first circuit board assembly comprising a first circuit board, and the pulse generator and the optical transmitter disposed on the first circuit board, and the optical signal receiving device comprises a second circuit board assembly disposed in the second housing, the second circuit board assembly comprising a second circuit board, and the pulse detector and the optical receiver disposed on the second circuit board.

10. A laser projector comprising: A laser transmission cable according to any one of claims 1 to 8, further comprising a first connector and a second connector, wherein opposite ends of the at least one first optical fiber are respectively covered by the first connector and the second connector, and the optical signal transmitting device and the optical signal receiving device are respectively disposed in the first connector and the second connector; a light source system comprising the laser light source and the switch, wherein the second connector of the laser transmission cable is connected to the light source system; and An image projection component is movably connected to the light source system via the laser transmission cable, wherein the first connector of the laser transmission cable is connected to the image projection component.

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