A distress device, a distress system and a distress method in a mine rescue

Abstract

The application relates to a distress device, a distress system and a distress method in mine rescue. The distress device utilizes optical fibers laid in a mine to perform bidirectional communication with a controller end, and the distress device comprises a power supply, a shooting unit, a preprocessing unit, a coding and decoding unit and a signal output unit. The power supply provides power. The shooting unit shoots light transmitted in the optical fibers, and the light is emitted by a visible light generator of the controller end and carries information from the controller end. The preprocessing unit pre-processes each frame of image shot by the shooting unit. The coding and decoding unit decodes information pre-processed by the signal preprocessing unit. The signal output unit generates distress personnel identifiable information from the decoded information and outputs the information or converts information on the distress personnel side into a signal recognizable by the optical fibers and outputs the signal. By utilizing the distress device, accurate and reliable communication between underground distress personnel and overground rescue personnel can be realized.

Description

Technical Field

[0001] This invention relates to the technical field of mine rescue, and more particularly to a distress call device and method for mine rescue. Background Technology

[0002] In the past, during mine accident rescues, fiber optic cables laid in the mine could transmit sound from the location where they were laid to the ground control system. However, rescuers on the ground could not transmit messages via fiber optic cables. Summary of the Invention

[0003] This invention provides a distress call device, distress call system, and distress call method for mine rescue, which enables accurate and reliable communication between personnel calling for help underground and personnel rescuing on the surface.

[0004] In a first aspect, embodiments of the present invention provide a distress call device that utilizes optical fibers laid in a mine for bidirectional communication with a controller. The distress call device includes: a power supply for providing power; a shooting unit for shooting light transmitted in the optical fiber, wherein the light is emitted by a visible light generator at the controller and carries information from the controller; a preprocessing unit for preprocessing each frame of the image shot by the shooting unit; an encoding / decoding unit for decoding the preprocessed information; and a signal output unit for generating recognizable information for the distress caller from the decoded information and outputting it, or converting the information from the distress caller's side into a signal recognizable by the optical fiber and outputting it.

[0005] In the aforementioned distress call device, the signal preprocessing unit performs ROI cropping on each frame of image acquired by the capturing unit; converts the cropped image from RGB color space to HSV or YCrCb color space; and retains the brightness information of predetermined color components of the image while removing other color components. The encoding / decoding unit calculates the average brightness value for the image region after ROI cropping and obtains the brightness and time curves; performs smoothing filtering on the brightness and time curves; extracts features of flicker period, duty cycle, and continuous mode based on the smoothed and filtered curves; and performs STFT time-domain analysis based on the extracted features for decoding.

[0006] In the aforementioned distress call device, the signal output unit converts the decoded information into information recognizable by the distress caller based on a pre-stored lookup table before outputting it.

[0007] The aforementioned distress call device further includes: a storage unit that pre-stores predetermined information as information for the distress caller; and a distress call button that, when pressed, can transmit the predetermined information to the signal output unit, so that the signal output unit transmits the information to the optical fiber.

[0008] In the aforementioned distress call device, the optical fiber can recognize signals including vibration signals, and the distress call device also includes a retractable contact rod that can be directly connected to the optical fiber to transmit the vibration signals.

[0009] In the aforementioned distress call device, the optical fiber can recognize signals including voice signals, and the signal output unit is a sound playback unit for playing the voice signals.

[0010] The aforementioned distress call device also includes: a direction indicator unit for indicating direction; and a map storage / viewing unit for storing a plan view of the mine, which the distress caller can view.

[0011] In a second aspect, embodiments of the present invention provide a distress call system, including the distress call device described in the first aspect above; and an optical fiber for bidirectional communication between the distress call device and a controller.

[0012] In a third aspect, embodiments of the present invention provide a method for calling for help, which utilizes optical fibers laid in the mine to conduct bidirectional communication with a controller, including the following steps: the optical fiber transmits vibration or sound information from the person calling for help to the controller; and the person calling for help obtains the information transmitted by the rescuers based on the optical signal transmitted by the optical fiber.

[0013] In a third aspect, embodiments of the present invention provide a distress call method that utilizes optical fibers laid in a mine for bidirectional communication with a controller, comprising: a shooting step, shooting the light transmitted in the optical fiber, the light being emitted by a visible light generator at the controller and carrying information from the controller; a preprocessing step, preprocessing each frame of the shot image; an encoding / decoding step, decoding the preprocessed information; and a signal output step, generating and outputting information recognizable by rescuers from the decoded information, or converting the information from the distress caller's side into a signal recognizable by the optical fiber and outputting it.

[0014] The calling device, calling system, and calling method provided by the present invention enable accurate and reliable communication between downhole rescue personnel and surface rescue personnel. Attached Figure Description

[0015] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the embodiments of the present invention will be briefly introduced below. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 A schematic diagram of a distress call device according to an embodiment of the present invention is shown; Figure 2This is a schematic diagram showing the structure of a distress call device for receiving signals; Figure 3 This is a flowchart illustrating an example of a preprocessing unit performing preprocessing; Figure 4 This is a flowchart illustrating an example of how the encoding / decoding unit decodes preprocessed information; Figure 5 A schematic diagram of another example of a distress call device according to an embodiment of the present invention is shown; Figure 6 This is a flowchart illustrating an example of the distress call method of the present invention. Detailed Implementation

[0017] The features and exemplary embodiments of various aspects of the present invention will now be described in detail. To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only configured to explain the present invention and are not configured to limit the present invention. For those skilled in the art, the present invention can be practiced without some of these specific details. The following description of the embodiments is merely intended to provide a better understanding of the present invention by illustrating examples of the invention.

[0018] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0019] In mines, optical fibers used include grating fibers, interferometric fibers, and Rayleigh scattering-based fibers. Grating fibers work by utilizing the slight deformation of the grating caused by external sound waves or vibrations, resulting in changes in the frequency, phase, and amplitude of the reflected light. By demodulating the corresponding parameters and using a sound reconstruction algorithm, the sound information of the environment at each grating point can be obtained. Interferometric fiber optic acoustic sensing (IFOS) is a high-sensitivity sensing technology that converts sound wave or vibration signals into measurable optical signals based on the interference effect of light and the sensing characteristics of optical fibers. The original sound wave information is then reconstructed using a demodulation algorithm. Rayleigh scattering-based fibers use a single ordinary optical fiber simultaneously as both a "sensing medium" and a "transmission medium." By detecting the coherent changes in the backscattered Rayleigh light within the fiber, distributed, blind-zone-free monitoring of acoustic / vibration signals along the entire fiber length is achieved.

[0020] This invention proposes a distress call device for mine rescue operations. Trapped personnel in the mine carry the distress call device and can use it to communicate two-way with personnel on the surface via optical fiber.

[0021] Example 1 Figure 1 This is a schematic diagram illustrating the structure of an example of a distress call device according to an embodiment of the present invention. The distress call device 1 utilizes an optical fiber laid in the mine for bidirectional communication with a controller. The distress call device 1 includes: a power supply 11 for providing power; a shooting unit 12 for shooting the light transmitted in the optical fiber, the light being emitted by a visible light generator at the controller and carrying information from the controller; a preprocessing unit 13 for preprocessing each frame of the image captured by the shooting unit; an encoding / decoding unit 14 for decoding the preprocessed information; and a signal output unit 15 for generating recognizable information for the distress caller from the decoded information and outputting it, or for converting the information from the distress caller's side into a signal recognizable by the optical fiber and outputting it.

[0022] The distress call device 1 is a portable device. Mine workers carry the distress call device into the mine. When an accident occurs in the mine and rescue is needed, such as a water seepage or collapse, and rescuers need to wait for rescue from the surface, communication between the surface rescuers and the person calling for help can improve rescue efficiency and ensure the safety of personnel.

[0023] In the past, when optical fibers were laid in mines, miners could emit sound or vibration signals to transmit these signals to the surface via optical fibers, thus relaying their location to surface rescuers. In this invention, miners can also use a distress signaling device and optical fibers to communicate two-way with surface rescuers.

[0024] The distress call device 1 includes a power supply 11, which provides power to each unit within the distress call device to enable it to function properly. The interface between the power supply and other units is explosion-proof.

[0025] During rescue operations, ground rescuers can use a red light pen or a modulated laser source to emit fixed light signals. The flashing frequency of the light signal can be used to transmit information. For example, when the light source emits a light signal at a frequency of 1Hz, it indicates that ground rescuers have responded; when it emits a light signal at a frequency of 2Hz, it indicates that the rescue has begun; and when it emits a light signal at a frequency of 5Hz, it indicates that the person calling for help should remain still. Alternatively, information can also be transmitted by varying the length of the light emission. For example, when the light source emits light at intervals of three short flashes followed by one long flash, it indicates that rescue equipment is being lowered.

[0026] In an emergency, at the rescue end of the mine, rescuers can strip the outer sheath of the optical fiber S laid at their location to expose the light-transmitting portion S'. Light from this portion S' can then pass through to the outside mine. Rescuers can directly observe the light emission from the optical fiber to assess the rescue situation on the surface based on predefined criteria.

[0027] In addition, the shooting unit 12 is installed on the distress call device 1. The person calling for help can aim the shooting unit 12 of the distress call device 1 at the light-transmitting part S' of the optical fiber to take a picture. Figure 2 This is a schematic diagram illustrating the structure of a distress call device for receiving signals. In the event of an accident, due to the urgency of the situation, the person calling for help can strip the outer sheath of the optical fiber S laid at their location to obtain the light-transmitting portion S' of the fiber. At this time, the light in the light-transmitting portion S' of the fiber can pass through to the outside mine. The person calling for help uses the shooting unit 12 of the distress call device 1 to shoot at the light-transmitting portion S' of the fiber to obtain video of the light signal in the fiber. This light signal can be emitted by a visible light generator K at the controller end, such as a red light pen or a laser generator, and carries information from the controller end. This information may be information that ground rescuers need to ask the person calling for help.

[0028] Here, the imaging unit 12 of the distress call device is, for example, a camera. As the core component for image acquisition, the performance of the camera directly affects the accuracy of subsequent flicker detection and decoding. To ensure clear capture of downhole flicker signals, this distress call device uses a camera with a frame rate ≥ 30fps. This frame rate avoids missing flicker signals due to excessively low frame rates. Preferably, the distress call device uses a camera with a frame rate of 60fps, as the optimal frame rate of 60fps further improves the real-time performance and completeness of signal capture. Additionally, the camera in this distress call device can use a camera with a resolution ≥ 640×480. This resolution ensures image clarity, meeting the requirements for flicker signal recognition, while avoiding excessive image processing pressure and response delays caused by excessively high resolution. Furthermore, the camera supports manual exposure and gain lock. Due to the complex lighting environment downhole, manual exposure allows adjustment of exposure parameters according to the actual light intensity, while gain lock prevents abnormal image brightness caused by light fluctuations, ensuring the accuracy of subsequent brightness analysis.

[0029] The preprocessing unit 13 of the distress call device 1 is used to optimize the raw images captured by the camera, remove useless information, highlight the characteristics of the flickering signal, and provide high-quality image data for subsequent flickering detection and decoding. Figure 3 This is a flowchart illustrating an example of preprocessing performed by the preprocessing unit. First, in step S31, the preprocessing unit 13 performs ROI cropping on each frame of the image acquired by the capturing unit. ROI cropping is used to select areas in the image where flicker signals may exist, remove irrelevant background areas, reduce the amount of data processed, and improve processing efficiency. Then, in step S32, the cropped image is converted from the RGB color space to the HSV or YCrCb color space because the RGB color space is greatly affected by light, while the HSV or YCrCb color space can better separate brightness and color information, facilitating the subsequent extraction of brightness features of the flicker signal. Finally, in step S33, other color components are removed, retaining only the brightness information of predetermined color components of the image, such as retaining the brightness information of the red component. This is because flicker signals in underground rescue are mostly red and rely on brightness changes to convey information; retaining this type of component can further highlight the flicker signal, suppress irrelevant color interference, and ensure the accuracy of subsequent brightness analysis.

[0030] The encoding / decoding unit 14 receives each frame of image preprocessed by the preprocessing unit 12 and decodes the preprocessed information. Figure 4This is a flowchart illustrating an example of the encoding / decoding unit decoding preprocessed information. In the encoding / decoding unit 14, firstly, in step S41, the average brightness value of the preprocessed ROI region is calculated and a brightness-time curve is generated, thereby converting the spatial brightness information of the image into a brightness change curve in the time dimension, intuitively reflecting the time change pattern of the flicker signal; in step S42, smoothing filtering is performed on the brightness and time curves. Smoothing filtering is used to eliminate brightness fluctuations caused by image noise, and peak detection is used to accurately identify peak points in the brightness curve, thereby determining the periodic characteristics of the flicker signal; in step S43, features of flicker period, duty cycle, and continuous mode are extracted based on the smoothed curve, thereby extracting the key features of the flicker signal; in step S44, STFT (Short-Time Fourier Transform) time-domain analysis is performed based on the extracted features for decoding. Compared with traditional time-domain decoding methods, STFT can simultaneously take into account time resolution and frequency resolution, accurately identify the frequency characteristics of the flicker signal, and achieve accurate decoding of time-series signals.

[0031] Optionally, anti-interference design can also be implemented. Considering that electromagnetic interference and light interference in the downhole environment may cause slight fluctuations in the flicker signal frequency, for example, a frequency deviation of ±20% is allowed. This deviation range can adapt to actual interference scenarios while avoiding misinterpretations due to excessive deviation.

[0032] Alternatively, the decoding result can be confirmed for N consecutive cycles, where N is between 3 and 10 and can be adaptively adjusted. To further suppress misinterpretations and ensure the reliability of the decoding result, when the downhole interference is strong, the value of N can be increased to raise the confirmation threshold of the decoding result; when the interference is weak, the value of N can be decreased to improve the decoding response speed. The above-mentioned anti-interference design limitations are all to adapt to the complex downhole interference environment and achieve accurate decoding.

[0033] The signal output unit 15 can convert the decoded information into information recognizable by the caller based on a pre-stored lookup table before outputting it. That is, the signal output unit generates recognizable information for rescue personnel to transmit the information from the caller's side to the controller via the optical fiber. This recognizable information can be any of text, images, or voice.

[0034] In addition, the signal output unit 15 can convert the information from the person calling for help into a signal that can be recognized by optical fiber. In the mine, the person calling for help can directly emit a sound signal to be transmitted through optical fiber. However, when the noise in the mine is high or the person calling for help is in a critical situation and cannot shout, the signal output unit 15 of the distress call device 1 can output a sound signal in a frequency band that is easy to recognize, thereby outputting a signal that is easier to be recognized by the controller end through optical fiber.

[0035] According to the aforementioned distress call device 1, two-way communication can be realized between the distress caller in the mine and the rescuer above the ground. Thus, the distress caller can transmit the situation at the mine accident site to the rescuer, and the rescuer above the ground can transmit predetermined information to the distress caller in the mine based on a pre-arranged agreement.

[0036] Example 2 Figure 5 A schematic diagram of another emergency call device according to an embodiment of the present invention is shown. This emergency call device 10 includes a power supply 11, a shooting unit 12, a preprocessing unit 13, an encoding / decoding unit 14, and a signal output unit 15. The structure is the same as in Embodiment 1, and will not be repeated here. The difference from Embodiment 1 is that the emergency call device 10 in Embodiment 2 also includes a retractable contact rod 16. In a mining environment with high noise levels, sound signals are significantly affected by noise when propagating through the air to the optical fiber. The inclusion of the retractable contact rod 16 in the emergency call device 10 allows it to be extended from the device when necessary, connecting to the optical fiber S, and outputting a sound signal in a frequency band easily identifiable by speech through the information output unit 15 of the emergency call device 10. This sound signal is transmitted to the optical fiber via the retractable contact rod 16, reducing interference from external noise and enabling the controller to obtain a clearer sound signal.

[0037] Optionally, in the above embodiments, the distress call device may further include: a storage unit that pre-stores predetermined information as information for the person making the distress call; and a distress call key that, when pressed, can transmit the predetermined distress call information to the signal output unit, so that the signal output unit can transmit it to the optical fiber. Thus, an easily identifiable distress signal can be emitted through the distress call device without complex operations.

[0038] Optionally, in the distress call device of the above embodiments, the signals that the optical fiber can recognize include vibration signals. The distress call device can transmit the vibration signals by directly connecting the retractable contact rod to the optical fiber.

[0039] Optionally, in the distress call device of the above embodiments, the signal that the optical fiber can recognize includes a voice signal, and the signal output unit can be a sound playback unit for playing the voice signal.

[0040] Optionally, in the distress call device of the above embodiments, the distress caller's identifiable information includes at least one of voice information, text information, and image information, and the distress call device also includes a display and a speaker.

[0041] Optionally, the distress call device in the above embodiments further includes: a direction indicator unit for indicating direction; and a map storage / viewing unit for storing a plan view of the mine, which the distress caller can view. The direction indicator unit is used to indicate the basic direction in the event of a mine accident or getting lost, such as using a compass. The map storage / viewing unit can store and view the corresponding mine plan view, which can assist trapped personnel in escaping and identifying routes.

[0042] The present invention also provides a distress call system, which may include: the aforementioned distress call device; and an optical fiber for bidirectional communication between the distress call device and a controller. This distress call system enables bidirectional communication during rescue operations using optical fiber. As an example, the optical fiber can be a Rayleigh scattering-based DAS (Distributed Acoustic Sensing) optical fiber.

[0043] This invention also provides a method for calling for help, which utilizes optical fibers laid in the mine for bidirectional communication with a controller. The method includes the following steps: the optical fiber transmits vibration or sound information from the person calling for help to the controller; and the person calling for help obtains the information transmitted by the rescuers based on the light signal transmitted through the optical fiber. In emergency situations such as mine disasters, the person calling for help can strip the outer sheath of the optical fiber S laid at their location to obtain the light-transmitting portion S' of the fiber. Light from this portion S' can then pass through to the outside mine. The person calling for help can directly observe the light emission state of the optical fiber to determine the rescue situation on the surface based on predefined criteria. For example, information can be predefined based on changes in the brightness or duration of light emission, and the person calling for help underground can interpret the rescue situation on the surface based on the state of the transmitted light.

[0044] This invention also provides another method for calling for help. Figure 6 This is a flowchart illustrating an example of the distress call method of the present invention. The distress call method includes: a capturing step S61, capturing light transmitted in the optical fiber, the light being emitted by a visible light generator at the controller end and carrying information from the controller end; a preprocessing step S62, preprocessing each captured frame; an encoding / decoding step S63, decoding the preprocessed information; and a signal output step S64, generating distress-identifiable information from the decoded information and outputting it, or converting the distress-identifier's information into a signal recognizable by the optical fiber and outputting it. The description of each step is related to... Figure 1 The descriptions of each unit are basically the same, so the descriptions are omitted here.

[0045] Based on the above-mentioned distress call method, two-way communication can be achieved between surface rescuers and underground distress callers during mine rescue operations.

[0046] The following explanation uses Rayleigh scattering-based optical fiber rescue as an example. In Rayleigh scattering, a single ordinary optical fiber serves as both a "sensing medium" and a "transmission medium." By detecting the coherent changes in the backscattered Rayleigh light within the fiber, distributed, blind-zone-free monitoring of acoustic / vibration signals across the entire fiber's length is achieved. The quartz material of the optical fiber contains nanoscale refractive index inhomogeneities. When laser light propagates through the fiber, it collides with these inhomogeneities, generating backscattered Rayleigh light—that is, some light is reflected back to the light source in the opposite direction to the incident light. In the event of an accident in a mine, underground personnel can transmit a distress signal to the surface controller via optical fiber by emitting a predetermined knocking sound. In emergencies, underground personnel can remove the outer sheath of the optical fiber. Surface personnel, upon hearing the distress call from underground, send back an optical signal carrying predetermined information. Underground personnel can interpret the information transmitted by the rescue personnel by observing the optical signal on the exposed portion of the optical fiber. In addition, personnel calling for help underground can use their own portable distress signaling devices to capture the light emitted by the fiber optic cable. These devices can then preprocess and decode the light signal as described above, thereby obtaining information recognizable by underground rescuers. The distress signaling device enables accurate and reliable two-way communication between surface and underground rescue personnel.

[0047] It should be clarified that the present invention is not limited to the specific configurations and processes described above and shown in the figures. For the sake of brevity, detailed descriptions of known methods are omitted here. In the above embodiments, several specific steps are described and shown as examples. However, the method process of the present invention is not limited to the specific steps described and shown. Those skilled in the art can make various changes, modifications, and additions, or change the order of steps, after understanding the spirit of the present invention.

[0048] It should also be noted that the exemplary embodiments mentioned in this invention describe methods or systems based on a series of steps or apparatus. However, this invention is not limited to the order of the steps described above; that is, the steps can be performed in the order mentioned in the embodiments, or in a different order, or several steps can be performed simultaneously.

[0049] The above description is merely a specific embodiment of the present invention. It should be understood that the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and such modifications or substitutions should all be covered within the scope of protection of the present invention.

Claims

1. A distress call device, utilizing optical fibers laid in a mine for bidirectional communication with a controller, the distress call device comprising: Power source, providing electricity; The imaging unit captures images of the light transmitted in the optical fiber. The light is emitted by a visible light generator at the controller end and carries information from the controller end. The preprocessing unit performs preprocessing on each frame of images captured by the shooting unit; The encoding / decoding unit decodes the information preprocessed by the preprocessing unit. as well as The signal output unit generates and outputs information that can be recognized by the caller after decoding, or converts the information from the caller's side into a signal that can be recognized by optical fiber and outputs it.

2. The distress call device according to claim 1, wherein, The preprocessing unit The ROI is cropped for each frame of image acquired by the shooting unit; Convert the cropped image from the RGB color space to the HSV or YCrCb color space; as well as Preserve the luminance information of predetermined color components of the image while removing other color components. The encoding / decoding unit Calculate the average brightness value for the image region after ROI cropping and obtain the brightness and time curves; Smoothing filters are applied to the brightness and time curves; Based on the smoothed and filtered curve, features of flicker period, duty cycle and continuous mode are extracted. as well as Decoding is performed based on STFT time-domain analysis of the extracted features.

3. The distress call device according to claim 1 or 2, wherein, The signal output unit converts the decoded information into information that can be recognized by the person calling for help based on a pre-stored lookup table before outputting it.

4. The distress call device according to claim 1, further comprising: A storage unit, wherein the storage unit pre-stores predetermined information as information for the person calling for help; When pressed, the distress button transmits the predetermined information to the signal output unit, which then transmits the information to the optical fiber.

5. The distress call device according to claim 1 or 2, wherein, The optical fiber can recognize signals including vibration signals. The distress call device also includes a retractable contact rod that can be directly connected to the optical fiber to transmit the vibration signal.

6. The distress call device according to claim 1 or 2, wherein, The optical fiber can recognize signals including sound signals. The signal output unit is a sound playback unit used to play the sound signal.

7. The distress call device according to claim 1 or 2, wherein, Also includes: Direction indicating unit, used to indicate direction; and The map storage / viewing unit stores a plan view of the mine, which can be viewed by rescue personnel.

8. A distress call system, wherein, Includes the distress call device as described in any one of claims 1 to 7; as well as Optical fiber is used to enable bidirectional communication between the distress call device and the controller.

9. A distress call method, utilizing optical fibers laid in a mine for bidirectional communication with a controller, comprising the following steps: The optical fiber transmits vibration or sound information from the person calling for help to the controller; and The person calling for help obtains the information transmitted by the rescuers based on the optical signal transmitted through the optical fiber.

10. A distress call method, utilizing optical fibers laid in the mine for bidirectional communication with a controller, comprising: The shooting step involves capturing images of the light transmitted in the optical fiber. The light is emitted by a visible light generator at the controller end and carries information from the controller end. The preprocessing step involves preprocessing each frame of the captured image. The encoding and decoding steps involve decoding the preprocessed information. as well as The signal output step involves either generating recognizable information for the person calling for help from the decoded information and outputting it, or converting the information from the person calling for help into a signal recognizable by the optical fiber and outputting it.

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