Light curtain receiving device and light curtain emitting device

Abstract

The application relates to a light curtain receiving device and a light curtain emitting device. In a receiving state, the light curtain receiving device controls each receiving unit to be opened in turn in each round receiving scanning process according to time sequence information in coding information through a receiving processing circuit, so that the receiving unit receives light signals emitted by the light curtain emitting device, then converts the light signals into electric signals, and compares the brightness information of the electric signals with the brightness information of the coding information. In this way, it can be judged whether the light signals received by the receiving unit according to the time sequence information in the coding information are the same as the light signals emitted by the matched light curtain emitting device. If the brightness information of the electric signals is consistent with the brightness information of the coding information, it indicates that the two light curtain devices are matched, and there is no shelter in the light curtain monitoring range. At this time, the receiving processing circuit controls an external output control circuit to output a normal control signal to indicate that the external equipment is normally operated. The light curtain receiving device has high anti-interference performance and can improve the accuracy of light curtain monitoring.

Description

Technical Field

[0001] This application relates to the field of automated safety protection technology, and in particular to a light curtain transmitter and a light curtain receiver. Background Technology

[0002] With the development of industrial technology, potentially dangerous equipment is appearing more and more frequently in modern factories. When operators of this equipment do not follow standard operating procedures, accidents such as operators getting caught in the equipment can easily occur, causing personal injury and death, and resulting in huge economic losses for the company. Existing safety light curtain systems consist of two parts: a light curtain transmitter and a light curtain receiver. The transmitter emits a series of infrared beams, which are received by the receiver. When the receiver successfully receives the infrared light emitted by the transmitter, it outputs a normal signal, allowing the external control unit to control the large equipment normally. When an object obstructs the path between the transmitter and receiver, an abnormal signal is output, prompting the equipment to stop or brake in time.

[0003] In practical industrial applications, multiple light curtain systems are often installed when it is necessary to monitor whether a light curtain is obstructed over a wider area. In this case, the multiple light curtains are positioned close together, such as... Figure 1 As shown, the two light curtain systems (1) and (2) are set to be close to each other. Since the light source is divergent when it is actually output, the receiver of light curtain (2) will be interfered with by the light signal emitted by light curtain (1). This will cause the receiver of light curtain (2) to make a misjudgment, resulting in the loss of the system's safety function. Summary of the Invention

[0004] This application provides an anti-interference light curtain receiving device.

[0005] A light curtain receiving device, the light curtain receiving device comprising:

[0006] Multiple receiving units;

[0007] External output control circuit;

[0008] The receiving and processing circuit is connected to the external output control circuit and each of the receiving units, respectively, and is used in the receiving state:

[0009] According to the timing information in the encoding information, each receiving unit is controlled to turn on in turn during each round of receiving and scanning process, so that the receiving unit receives the light signal emitted by the light curtain transmitting device and converts the light signal into an electrical signal;

[0010] The receiver receives the electrical signal output by the receiving unit. If the brightness information of the electrical signal is consistent with the brightness information of the encoded information, the receiver controls the external output control circuit to output a normal control signal to indicate that the external device is operating normally.

[0011] The light curtain receiving device further comprises:

[0012] A current-voltage conversion circuit is connected with each of the receiving units and the receiving processing circuit, and is configured to convert the electric signal from a current signal to a voltage signal.

[0013] The brightness information of the encoding information comprises a first ordinal number in a current receiving scanning process, and the receiving processing circuit comprises:

[0014] A first threshold comparator is connected with the current-voltage conversion circuit, and is configured to compare the voltage value of the electric signal with a first threshold value to generate a first pulse signal.

[0015] A second threshold comparator is connected with the current-voltage conversion circuit, and is configured to compare the voltage value of the electric signal with a second threshold value to generate a second pulse signal.

[0016] A receiving control unit is connected with the first threshold comparator, the second threshold comparator and the external output control circuit, and is configured to control the external output control circuit to output the normal control signal if the effective pulse of the first pulse signal corresponds to a second ordinal number of the effective pulse of the second pulse signal, and the first ordinal number is consistent; and the first threshold value is greater than the second threshold value.

[0017] The receiving processing circuit further comprises:

[0018] A receiving scanning control unit is connected with the receiving control unit and each of the receiving units.

[0019] The receiving control unit is further configured to output a receiving driving signal according to the timing information in the encoding information.

[0020] The receiving scanning control unit is further configured to control each of the receiving units to be turned on in turn in each round receiving scanning process according to the receiving driving signal.

[0021] The receiving unit comprises:

[0022] A photodiode, an anode of the photodiode being connected with a first end of the current-voltage conversion circuit.

[0023] A receiving controller, a control end of the receiving controller being connected with the receiving scanning control unit, a first connection end of the receiving controller being connected with a cathode of the photodiode, and a second connection end of the receiving controller being connected with a second end of the current-voltage conversion circuit.

[0024] The receiving scanning control unit is further configured to control the receiving controller to turn on a conductive path between the first connection end and the second connection end according to the receiving driving signal, so that the receiving unit is turned on.

[0025] The light curtain receiving device further comprises:

[0026] A first amplification circuit is connected with the current-voltage conversion circuit, the first threshold comparator and the second threshold comparator respectively, and is configured to amplify the electrical signal.

[0027] The light curtain receiving device further comprises:

[0028] A first communication circuit is connected with the receiving processing circuit, and is configured to receive the emission end parameter information sent by the light curtain emitting device and transmit the emission end parameter information to the receiving processing circuit.

[0029] The receiving processing circuit is further configured to enter the receiving state if the emission end parameter information is consistent with the receiving end parameter information.

[0030] The receiving processing circuit is further configured to exit the receiving state if the brightness information of the electrical signal is inconsistent with the brightness information of the encoding information, and send a system control instruction to the light curtain emitting device through the first communication circuit to instruct the light curtain emitting device to exit the emitting state.

[0031] The receiving processing circuit is further configured to send the receiving end parameter information to the light curtain emitting device through the first communication circuit.

[0032] The receiving processing circuit is further configured to send the encoding information to the light curtain emitting device through the first communication circuit in the receiving state.

[0033] The light curtain receiving device further comprises:

[0034] A first safety indication circuit is connected with the receiving processing circuit.

[0035] The receiving processing circuit is further configured to control the first safety indication circuit to output first abnormal prompt information if the brightness information of the electrical signal is inconsistent with the brightness information of the encoding information.

[0036] A light curtain emitting device for emitting light signals to the light curtain receiving device of any one of claims 1 to 11, the light curtain emitting device comprising:

[0037] A plurality of light emitting units.

[0038] The emission processing circuit is connected with each of the light emitting units, and is configured to control each of the light emitting units to emit light signals with varying brightness in each of the receiving scanning processes in the emission state according to the timing information and the brightness information in the encoding information, and each of the light emitting units emits the light signals with varying brightness in each of the receiving scanning processes in the process of controlling the light emitting units to emit light signals.

[0039] The light emitting unit comprises:

[0040] a light emitting diode;

[0041] an emission controller, a first connection end of the emission controller is connected with the cathode of the light emitting diode, and a second connection end of the emission controller is connected with a ground end;

[0042] The emission processing circuit comprises:

[0043] an emission scanning control unit, which is connected with a control end of each of the emission controllers;

[0044] an emission control unit, which is connected with the emission scanning control unit and the anode of the light emitting diode, and is configured to output a brightness control signal to the light emitting diode according to the brightness information in the encoding information, and output an emission driving signal to the emission scanning control unit according to the timing information in the encoding information, so as to drive the emission scanning control unit to control the emission controller to turn on a conductive path between the first connection end and the second connection end, so that the light emitting diode emits light.

[0045] The light curtain emission device further comprises:

[0046] a digital-to-analog conversion circuit, which is connected with the emission control unit and the anode of the light emitting diode, and is configured to convert the brightness control signal from a digital signal to an analog signal.

[0047] The light curtain emission device further comprises:

[0048] a second amplification circuit, which is connected with the digital-to-analog conversion circuit and the anode of the light emitting diode, and is configured to amplify the brightness control signal.

[0049] The light curtain emission device further comprises:

[0050] a second communication circuit, which is connected with the emission processing circuit, and is configured to receive receiving end parameter information sent by the light curtain receiving device, and transmit the receiving end parameter information to the emission processing circuit.

[0051] The emission processing circuit is further configured to enter the emission state if the receiving end parameter information is consistent with the emission end parameter information.

[0052] The second communication circuit is also configured to receive system control instructions and transmit the system control instructions to the transmission processing circuit;

[0053] The transmission processing circuit is also configured to exit the transmission state according to the system control instructions.

[0054] The light curtain transmission device further comprises:

[0055] A second safety indication circuit is connected to the transmission processing circuit;

[0056] The transmission processing circuit is also configured to control the second safety indication circuit to output second abnormal prompt information according to the system control instructions.

[0057] The transmission processing circuit is also configured to send the transmission end parameter information to the light curtain receiving device through the second communication circuit.

[0058] The transmission processing circuit is also configured to receive the encoding information sent by the light curtain receiving device through the second communication circuit.

[0059] The light curtain receiving device receives the light signals transmitted by the light curtain transmission device through the receiving processing circuit in the receiving state, and then converts the light signals into electrical signals, and compares the brightness information of the electrical signals with the brightness information of the encoding information. In this way, it can be determined whether the light signals received by the receiving unit according to the timing information in the encoding information are the same as the light signals transmitted by the matched light curtain transmission device. If the brightness information of the electrical signals is consistent with the brightness information of the encoding information, it indicates that the two light curtain devices are matched, and there is no obstruction in the light curtain monitoring range. At this time, the receiving processing circuit controls the external output control circuit to output a normal control signal to indicate that the external device is running normally. The light curtain receiving device has high anti-interference performance and can improve the accuracy of light curtain monitoring and ensure the safe operation of the external device. BRIEF DESCRIPTION OF DRAWINGS

[0060] Figure 1 An abnormal situation diagram when the light curtain is monitored;

[0061] Figure 2 A structure diagram of the light curtain receiving device of an embodiment of the present application;

[0062] Figure 3 A structure diagram of the light curtain receiving device of another embodiment of the present application;

[0063] Figure 4 A structure diagram of the light curtain receiving device of another embodiment of the present application;

[0064] Figure 5Timing diagram of the emission of the light curtain emitting device according to an embodiment of the present application;

[0065] Figure 6 Timing diagram of the encoding of the light curtain emitting device according to an embodiment of the present application;

[0066] Figure 7 Timing diagram of the reception of the light curtain receiving device according to an embodiment of the present application;

[0067] Figure 8 Waveform diagram of the analog current signal obtained by converting the light signal according to an embodiment of the present application;

[0068] Figure 9 Comparison diagram of the analog current signal obtained by converting the light signal under normal and abnormal conditions;

[0069] Figure 10 Structure diagram of the light curtain receiving device according to another embodiment of the present application;

[0070] Figure 11 Structure diagram of the light curtain receiving device according to another embodiment of the present application;

[0071] Figure 12 Structure diagram of the receiving scanning control unit according to an embodiment of the present application;

[0072] Figure 13 Structure diagram of the light curtain receiving device according to another embodiment of the present application;

[0073] Figure 14 Flow diagram of the light curtain monitoring method of the light curtain receiving device according to an embodiment of the present application;

[0074] Figure 15 Block diagram of the light curtain emitting device according to an embodiment of the present application;

[0075] Figure 16 Block diagram of the light curtain emitting device according to another embodiment of the present application;

[0076] Figure 17 Block diagram of the light curtain emitting device according to another embodiment of the present application;

[0077] Figure 18 Block diagram of the light curtain emitting device according to another embodiment of the present application;

[0078] Figure 19 Block diagram of the light curtain emitting device according to another embodiment of the present application;

[0079] Figure 20 Block diagram of the light curtain emitting device according to another embodiment of the present application. Embodiment

[0080] It should be understood that the specific embodiments described herein are merely exemplary and do not limit the application.

[0081] The technical solutions in the embodiments of the present application will be clearly and completely described with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative effort fall within the protection scope of the present application.

[0082] It should be understood that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present application are only used to explain the relative positional relationship, movement condition, etc. between components in a certain posture (as shown in the drawings), and if the certain posture changes, the directional indications also change accordingly. The connection can be direct connection or indirect connection.

[0083] In addition, the description such as “first”, “second” and the like in the present application is only for the purpose of description, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features defined as “first”, “second” can explicitly or implicitly include at least one of the features. In addition, the technical solutions of various embodiments can be combined with each other, but it must be based on the realization of a person of ordinary skill in the art, and when the combination of technical solutions contradicts each other or cannot be realized, it should be considered that the combination of technical solutions does not exist, and is not within the protection scope of the present application.

[0084] Figure 2 The structural block diagram of the light curtain receiving device of an embodiment is shown in Figure 2 The light curtain receiving device includes a plurality of receiving units 110, an external output control circuit 130 and a receiving processing circuit 120; the receiving processing circuit 120 is connected with the external output control circuit 130 and each receiving unit 110, and is used for, in a receiving state: controlling each receiving unit 110 to be turned on in each round of receiving scanning processes according to the time sequence information in the encoding information, so that the receiving unit receives the light signal emitted by the light curtain emitting device and converts the light signal into an electric signal; receiving the electric signal output by the receiving unit 110, and if the brightness information of the electric signal is consistent with the brightness information of the encoding information, controlling the external output control circuit 130 to output a normal control signal to indicate the external device to operate normally.

[0085] It can be understood that the receiving state can be a state allowing the receiving processing circuit 120 to perform certain actions. In the embodiment, in the receiving state, the receiving processing circuit 120 can control the receiving units 110 to be turned on, so that the receiving units 110 receive the light signals emitted by the light curtain emitting device, convert the light signals into electrical signals, and determine whether the brightness information of the light signals is consistent with the brightness information of the coded information.

[0086] In one aspect, when the receiving processing circuit 120 controls the receiving units 110, the receiving processing circuit 120 controls the receiving units 110 to be turned on in turn in each round of receiving scanning process according to the timing information in the coded information, so that only one receiving unit 110 is turned on at each moment to receive the light signals, and further convert the light signals into electrical signals. Therefore, the electrical signals carry the timing information of the receiving units 110, i.e., the timing information in the coded information. In another aspect, since the light signals are emitted by the emitting end according to the timing information and the brightness information in the specific coded information, the light signals carry the timing information and the brightness information in the specific coded information. When the light curtain is monitored, the receiving units 110 of the light curtain receiving device receive according to the emission of the light curtain emitting device matched therewith. The coded information on which the light curtain emitting device and the light curtain receiving device are based should be consistent. Therefore, only when the timing of the turning on of the receiving units 110 is consistent with the timing of the emission of the light signals by the light curtain emitting device, and there is no occlusion in the monitoring range between the light curtain emitting device and the light curtain receiving device, the receiving units 110 can completely receive the light signals emitted by the light curtain emitting device. By comparing the brightness information of the electrical signals with the brightness information of the coded information, if the brightness information of the electrical signals is consistent with the brightness information of the coded information, it indicates that the receiving end and the emitting end are based on the same coded information, i.e., the two light curtain devices are matched, and there is no occlusion in the monitoring range of the light curtain. At this time, the receiving processing circuit 120 can control the external output control circuit 130 to output a normal control signal to inform the external device that there is no obstacle at this time, and instruct the external device to operate normally. If the brightness information is not consistent, it indicates that at least one of the following two situations occurs: the receiving end and the emitting end are based on different coded information, i.e., the two light curtain devices are not matched, and there is an occlusion in the monitoring range of the light curtain. At this time, the receiving processing circuit 120 can control the external output control circuit 130 to output an abnormal control signal to instruct the external device to stop operating.

[0087] In one embodiment, the brightness information of the coded information can include the light signal information of the light curtain received by each receiving unit 110 in each round of receiving scanning process; specifically, the light curtain emitting device matched with the light curtain receiving device can include a plurality of light emitting units, and the light curtain emitting device can light up each light emitting unit in turn in each round of emitting scanning process; in each round of emitting scanning process, the brightness information of the coded information can include the light signal information of the light curtain emitted by each light emitting unit in turn, for example, the first light emitting unit emits a high-brightness light signal at time t1, the second light emitting unit emits a low-brightness light signal at time t2, the third light emitting unit emits a high-brightness light signal at time t3, and so on; in this case, if the brightness information of the electrical signal is consistent with the brightness information of the coded information, which is also the light signal information of the light curtain received by each receiving unit 110 in each round of receiving scanning process, it indicates that the two light curtain devices are matched, and there is no obstruction in the monitoring range of the light curtain.

[0088] In another embodiment, the brightness information of the encoding information can include the light signal information of the light-emitting units in the same round of the emission scanning process, and the light signal information of the non-target light-emitting units in the same round of the emission scanning process, wherein the non-target light-emitting units are the light-emitting units other than the light-emitting units emitting the light signal with the brightness change; wherein the light curtain emitting device matched with the light curtain receiving device can include a plurality of light-emitting units, and in each round of the emission scanning process, the light-emitting units can be turned on according to the timing information and the brightness information in the encoding information, and the light-emitting units can emit the light signal with the brightness change in each round of the emission scanning process, and the other light-emitting units in the same round of the emission scanning process can emit the light signal with the specific brightness, and the light signal with the specific brightness can be one of the low-brightness light signal, the non-light signal, or the high-brightness light signal; for example, in the first round of the emission scanning process, the first light-emitting unit emits the low-brightness, non-light, and high-brightness light signals in sequence at tx1, and the other light-emitting units emit the low-brightness light signal in turn at other time points, the second light-emitting unit emits the low-brightness light signal at tx2, the third light-emitting unit emits the low-brightness light signal at tx3, and so on; in the second round of the emission scanning process, the first light-emitting unit emits the low-brightness light signal at tz1, the second light-emitting unit emits the low-brightness, non-light, and high-brightness light signals in sequence at tz2, and the other light-emitting units emit the low-brightness light signal in turn at other time points; and the light-emitting mode of the light-emitting units in other rounds of the emission scanning process is similar. In this case, if the brightness information of the electrical signal is consistent with the brightness information of the encoding information, and the light signal information of the light-emitting units in each round of the emission scanning process and the light signal information of the non-target light-emitting units in the same round of the emission scanning process are received by the receiving units 110, it indicates that the two light curtain devices are matched, and there is no obstruction in the light curtain monitoring range, so that the receiving timing of the receiving end is controlled, and the light signal brightness is encoded, the interference of the non-matched light curtain emitting device on the light curtain receiving device can be excluded, and the accuracy of the light curtain monitoring is improved.

[0089] The light curtain receiving device controls each receiving unit 110 to be turned on in each round of receiving scanning process according to the timing information in the encoding information in the receiving state through the receiving processing circuit 120, so that the receiving unit 110 receives the light signal emitted by the light curtain emitting device, and then converts the light signal into an electric signal, and compares the brightness information of the electric signal with the brightness information of the encoding information. In this way, it can be determined whether the light signal received by the receiving unit 110 according to the timing information in the encoding information is the same as the light signal emitted by the matched light curtain emitting device. If the brightness information of the electric signal is consistent with the brightness information of the encoding information, it indicates that the two light curtain devices are matched, and there is no obstruction in the light curtain monitoring range. At this time, the receiving processing circuit 120 controls the external output control circuit 130 to output a normal control signal to indicate that the external device is running normally. The light curtain receiving device has high anti-interference performance and can improve the accuracy of light curtain monitoring and ensure the safe operation of the external device.

[0090] In one embodiment, the light curtain receiving device further comprises a current-voltage conversion circuit 140, as shown in Figure 3 The current-voltage conversion circuit 140 is connected with each receiving unit 110 and the receiving processing circuit 120 respectively, and is used to convert the electric signal from a current signal to a voltage signal.

[0091] It can be understood that the current-voltage conversion circuit 140 can be connected between the receiving unit 110 and the receiving processing circuit 120. The electric signal converted by the receiving unit 110 can be a current signal. In order to facilitate the processing of the receiving processing circuit 120, the current signal can be converted into a voltage signal through the current-voltage conversion circuit 140.

[0092] In one embodiment, the brightness information of the encoding information includes a first ordinal number in the current round of receiving scanning process, as shown in Figure 4 The receiving processing circuit 120 comprises a first threshold comparator 121, a second threshold comparator 122 and a receiving control unit 123. The first threshold comparator 121 is connected with the current-voltage conversion circuit 140, and is used to compare the voltage value of the electric signal with a first threshold to generate a first pulse signal; the second threshold comparator 122 is connected with the current-voltage conversion circuit 140, and is used to compare the voltage value of the electric signal with a second threshold to generate a second pulse signal; the receiving control unit 123 is connected with the first threshold comparator 121, the second threshold comparator 122 and the external output control circuit 130 respectively, and is used to control the external output control circuit 130 to output the normal control signal if the second ordinal number corresponding to the valid pulse of the first pulse signal is consistent with the first ordinal number; the first threshold is greater than the second threshold.

[0093] It is understood that the light curtain transmitter matched with the light curtain receiver may include multiple light-emitting units. During each round of transmission scanning, the light curtain transmitter can turn on each light-emitting unit in turn. The brightness information in the encoded information can instruct each light-emitting unit to emit light signals with varying brightness in each round of transmission scanning, and non-target light-emitting units in the same round of transmission scanning to emit low-brightness light signals. Non-target light-emitting units are those other than the light-emitting units emitting light signals with varying brightness. The transmission timing of the light-emitting units in the light curtain transmitter is referenced... Figure 5 As shown, taking an example with 8 light-emitting units, signals LD1 to LD8 represent the turn-on timing of each light-emitting unit, and signal "illum" represents the brightness of the light signal emitted when each light-emitting unit is turned on. In the first round of emission scanning process T1, during the time period from t10 to t12, the first light-emitting unit successively emits three types of light signals: low brightness (at the initial time of t10), no brightness (at the initial time of t11), and high brightness (at the initial time of t12). At the initial time of each of the other time periods, other light-emitting units take turns emitting low brightness light signals. t13 Initially, the second emitting unit emits a low-brightness light signal; at t14, the third emitting unit emits a low-brightness light signal, and so on. In the second round of emission scanning process T2, the first emitting unit emits a low-brightness light signal during time period t20; from t21 to t23, the second emitting unit successively emits three light signals: low brightness (at the initial time of t21), no brightness (at the initial time of t22), and high brightness (at the initial time of t23). At the initial time of each other time period, other emitting units take turns emitting low-brightness light signals. When there are 8 emitting units, there are 8 possible signal "illum" states, representing 8 encoding methods. (See reference...) Figure 6 As shown, in encoding method E1, the first light-emitting unit emits light signals during time periods a1 to a3, with a1 being low brightness, a2 being off, and a3 being high brightness. The remaining time periods a4 to a10 are emitted by the other seven light-emitting units, each emitting low brightness light signals. In encoding method E2, the second light-emitting unit emits light signals during time periods a2 to a4, with a2 being low brightness, a3 being off, and a4 being high brightness. The remaining time periods a1 and a5 to a10 are emitted by the other seven light-emitting units, each emitting low brightness light signals. The light emission patterns for other encoding methods can be determined according to... Figure 6 Similarly, these will not be elaborated upon here. The emission mode of the light-emitting unit in each emission scanning process can be determined according to... Figure 6 Each encoding method is executed.

[0094] The optical signals include high-brightness, low-brightness, and no-brightness signals. Among the electrical signals obtained by photoelectric conversion by the receiving unit 110, the current value converted from the high-brightness signal is the highest, followed by the low-brightness signal, and finally the no-brightness signal. When the light-emitting unit in the light curtain emitting device... Figure 5 When transmitting the optical signal according to the transmission timing shown, the current signal received by the current-to-voltage conversion circuit 140 can be referenced. Figure 7 The received analog signal Re is shown; where the received scan process T3 corresponds to Figure 5 The transmit scan period T1 and receive scan process T4 correspond to the transmit scan period T1 and receive scan process T4, respectively. Figure 5 The emission scan period is T2.

[0095] Specifically, when the matched light curtain transmitter emits a light signal, the receiving unit 110 converts the received light signal into an analog current signal during each receiving and scanning process, which can be referred to as... Figure 8 As shown, the current-to-voltage conversion circuit 140 is only used to convert electrical signals from current signals to voltage signals, therefore it does not change the waveform of the electrical signal. The waveform of the converted voltage signal is the same as... Figure 8 Consistent. By Figure 8 It can be seen that the amplitude of the electrical signal has three values: low amplitude, medium amplitude, and high amplitude. Taking the receiving scanning process L1 as an example, the voltage amplitude of the electrical signal is low during time period b2, high during time period b3, and medium during the remaining time periods. The first threshold comparator 121 is a high threshold comparator, used to compare the voltage value of the electrical signal with the first threshold. The first threshold is greater than the medium amplitude and less than the high amplitude. Therefore, the first pulse signal outputs a high-level pulse during time period b3 and a low-level pulse during the remaining time periods. The waveform of the first pulse signal is shown in the reference diagram. Figure 7 The signal C1 shown is a second threshold comparator 122, which is a low threshold comparator used to compare the voltage value of the electrical signal with the second threshold. The second threshold is greater than the low amplitude and less than the medium amplitude. Therefore, the second pulse signal b2 outputs a low-level pulse during its time period and a high-level pulse during the remaining time periods. The waveform of the second pulse signal is shown in the reference diagram. Figure 7 The signal C2 shown. The effective pulse of the second pulse signal is a high-level pulse, with... Figure 7 Taking the receiving scanning process T3 as an example, the second ordinal number of the effective pulse of the first pulse signal corresponding to the effective pulse of the second pulse signal is 2. Assuming that the first ordinal number of the current receiving scanning process is 2, the second ordinal number is the same as the first ordinal number, the light curtain transmitter and the light curtain receiver are matched, and there are no obstructions in the monitoring area, at this time the external output control circuit 130 can be controlled to output a normal control signal.

[0096] When monitoring light curtains, if interference from adjacent light curtains exists, the analog current signal converted by the receiving unit 110 can be used as a reference.Figure 9 The signal S2 shown, wherein the signal S1 is the signal when the reception is normal. In addition to the interference of the adjacent light curtain, there can be a very high brightness spot, such as a flying electric spark, a welding spark, a high-temperature debris, a laser beam, etc., as shown in (3). The shadow is a flying high-brightness spot, and when part of the receiving area is blocked, but the light signal emitted by the bright spot is received by the receiving end of the light curtain, the receiving end receives an error signal and cannot determine whether the signal is a bright spot or a normal signal, resulting in a false judgment, causing the system safety function to be lost. In this case, the analog current signal converted by the receiving unit 110 can refer to the signal S3 shown. Figure 1 In addition, there can be a short time of very high brightness, such as when the steel is in a molten state in a steel mill, and when the flying sparks occur, the entire operating environment will appear a short time of very high brightness, as shown in (4). In this case, whether the receiving area is blocked or not, the receiving end can always receive a saturated signal, and the system cannot determine whether the protection area is blocked. In this case, the analog current signal converted by the receiving unit 110 can refer to the signal S4 shown. Figure 9 Figure 1 Figure 9

[0097] Therefore, the low-amplitude and medium-amplitude signals in the electrical signal are filtered by the first threshold comparator 121 to obtain the first pulse signal, and the low-amplitude signals in the electrical signal are filtered by the second threshold comparator 122 to obtain the second pulse signal. Then, the receiving control unit 123 determines the second ordinal number of the valid pulse of the first pulse signal corresponding to the valid pulse of the second pulse signal, and compares it with the preset first ordinal number in the current round of receiving scanning process. If the comparison result is consistent, it indicates that the light curtain emitting device and the light curtain receiving device are matched, and there is no shielding object in the monitoring area. At this time, the external output control circuit 130 can be controlled to output a normal control signal.

[0098] In one embodiment, as shown in Figure 10 The receiving processing circuit 120 further includes a receiving scanning control unit 124. The receiving scanning control unit 124 is connected with the receiving control unit 123 and each receiving unit 110. The receiving control unit 123 is further configured to output a receiving driving signal according to the timing information in the encoding information. The receiving scanning control unit 124 is further configured to control each receiving unit 110 to be turned on in turn in each round of receiving scanning process according to the receiving driving signal.

[0099] It can be understood that the receiving scanning control unit 124 can directly control each receiving unit 110, which can include a plurality of switches. After receiving the receiving driving signal of the receiving control unit 123, one of the receiving units 110 can be controlled to be turned on according to the receiving driving signal.

[0100] In one embodiment, as shown in Figure 11 ​​​As shown, the receiving unit 110 includes a photodiode and a receiving controller 1101, an anode of the photodiode is connected with a first end of the current-voltage conversion circuit 140; a control end of the receiving controller 1101 is connected with the receiving scan control unit 124, a first connection end of the receiving controller 1101 is connected with a cathode of the photodiode, and a second connection end of the receiving controller 1101 is connected with a second end of the current-voltage conversion circuit 140; the receiving scan control unit 124 is further configured to control the receiving controller 1101 to turn on a conduction path between the first connection end and the second connection end according to the receiving driving signal, so that the receiving unit 110 is turned on.

[0101] It can be understood that the receiving controller 1101 can be a MOS tube, the control end can be a gate, one of the first connection end and the second connection end can be a source, and the other can be a drain, and the receiving scan control unit 124 controls the control end of the receiving controller 1101 to turn on the first connection end and the second connection end according to the receiving driving signal, so that the photodiode, the receiving controller 1101 and the current-voltage conversion circuit 140 form a conduction path, and the photodiode can receive the optical signal and further convert it into an electrical signal for transmission.

[0102] In one embodiment, as shown in Figure 12 The receiving scan control unit 124 can include a microcontroller 1242 and a plurality of shift registers 1241, the microcontroller 1242 is connected with the receiving control unit 123 and each shift register 1241 respectively, each shift register 1241 is connected in cascade, and the shift register 1241 can be composed of a plurality of D flip-flops, an output end Q of each D flip-flop is connected with the control end of the receiving controller 1101, and is configured to output a gate control signal. The number of the shift registers 1241 and the number of the D flip-flops can be determined according to the number of the receiving units 110, a plurality of receiving units 110 can form a group, the number of the shift registers 1241 is the same as the number of nodes of the light curtain, the number of the D flip-flops in each shift register 1241 is the same as the number of the receiving units 110 of a single node of the light curtain, for example, eight receiving units 110 form a node of the light curtain, one shift register 1241 can include eight D flip-flops, the microcontroller 1242 outputs a clock signal CP and a scan control signal DIN to each shift register 1241 according to the receiving driving signal, and an output DOUT of the last shift register 1241 is input to the microcontroller 1242 as a feedback signal.

[0103] Suppose that the light curtain emitting device matched with the light curtain receiving device emits light signals according to the emission timing sequence shown in Figure 5 The light curtain receiving device receives the light signals according to the receiving timing sequence shown in Figure 7The receiving timing receives the optical signal. In the first round of receiving scanning process T3, the scanning control signal DIN keeps high level for a period of time, and the clock signal CP rising edge saves the value of the scanning control signal DIN, maintains the output by the first D flip-flop, so that the first receiving controller 1101 is turned on, and the first photodiode completes the conversion of the optical signal and the output of the electrical signal. After the first receiving unit 110 sequentially completes the reception of the low-brightness optical signal, the non-brightness optical signal and the high-brightness optical signal, the first D flip-flop operation is completed. Then the clock signal CP triggers the output by the second D flip-flop, so that the first receiving controller 1101 is turned off, the second receiving controller 1101 is turned on, and the second photodiode completes the conversion of the optical signal and the output of the electrical signal. After the second receiving unit 110 completes the reception of the low-brightness optical signal, the second D flip-flop operation is completed. Similarly, the subsequent D flip-flops are sequentially output by the clock signal CP.

[0104] In the second round of receiving scanning process T4, the scanning control signal DIN keeps high level for a period of time, and the clock signal CP rising edge saves the value of the scanning control signal DIN, maintains the output by the first D flip-flop, so that the first receiving controller 1101 is turned on, and the first photodiode completes the conversion of the optical signal and the output of the electrical signal. After the first receiving unit 110 completes the reception of the low-brightness optical signal, the first D flip-flop operation is completed. Then the clock signal CP triggers the output by the second D flip-flop, so that the first receiving controller 1101 is turned off, the second receiving controller 1101 is turned on, and the second photodiode completes the conversion of the optical signal and the output of the electrical signal. After the second receiving unit 110 sequentially completes the reception of the low-brightness optical signal, the non-brightness optical signal and the high-brightness optical signal, the second D flip-flop operation is completed. Similarly, the subsequent D flip-flops are sequentially output by the clock signal CP. The control mode of the remaining receiving scanning processes is similar.

[0105] In one embodiment, as shown in Figure 13 The light curtain receiving device further comprises a first amplification circuit, which is connected with the current-voltage conversion circuit 140, the first threshold comparator 121 and the second threshold comparator 122 respectively, and is used for amplifying the electrical signal.

[0106] The first amplification circuit can be a differential amplification circuit, the current-voltage conversion circuit 140 can convert the current signal into a differential voltage signal, the differential voltage signal is converted into a single-ended voltage signal by a differential amplification circuit in the later stage, the converted signal is input into the receiving control unit 123 through the high threshold comparator and the low threshold comparator.

[0107] In one embodiment, as shown in Figure 13As shown, the light curtain receiving device further comprises a first communication circuit 160 connected with the receiving processing circuit 120, used for receiving the transmission end parameter information sent by the light curtain transmitting device and transmitting to the receiving processing circuit 120; the receiving processing circuit 120 is further used for entering the receiving state if the transmission end parameter information is consistent with the receiving end parameter information.

[0108] It can be understood that, by confirming whether the transmission end parameter information is consistent with the receiving end parameter information, it can be determined whether the light curtain receiving device and the light curtain transmitting device are matched, and if consistent, the two light curtain devices are matched, and the receiving processing circuit 120 enters the receiving state, so as to ensure the matching between the light curtain transmitting device and the light curtain receiving device, and improve the accuracy of light curtain monitoring. The transmission end parameter information and the receiving end parameter information can respectively include the number of single light curtain light source positions, the total length of the system, etc., the total length of the system is the number of light curtain segments, and the number of single light curtain light source positions is the number of receiving units 110 (for the receiving end) or the number of photodiodes (for the transmission end).

[0109] In one embodiment, the receiving processing circuit 120 is further used for exiting the receiving state if the brightness information of the electric signal is inconsistent with the brightness information of the coding information, and sending a system control instruction to the light curtain transmitting device through the first communication circuit 160 to instruct the light curtain transmitting device to exit the transmitting state.

[0110] It can be understood that, if the brightness information of the electric signal is inconsistent with the brightness information of the coding information, it indicates that the two light curtain devices are not matched, and / or there is an abnormal situation of a shielding object in the light curtain monitoring range, at this time, the light curtain receiving device exits the receiving state, stops receiving the light signal, and at the same time sends a system control instruction to the light curtain transmitting device, so that the light curtain transmitting device also stops transmitting the light signal, so as to ensure that the light curtain receiving device and the matched light curtain transmitting device stop working at the same time under the monitoring of abnormal situation, so as to reduce unnecessary energy consumption.

[0111] In one embodiment, the receiving processing circuit 120 is further used for sending the receiving end parameter information to the light curtain transmitting device through the first communication circuit 160.

[0112] It can be understood that the receiving end parameter information can be used for the light curtain transmitting device to determine whether it is consistent with the transmission end parameter information, and if consistent, it indicates that the light curtain transmitting device is matched with the light curtain receiving device, and then the light signal can be transmitted. Thus, by establishing the communication between the light curtain receiving device and the light curtain transmitting device, the matching confirmation of the two can be performed before the light curtain monitoring, and the accuracy of the light curtain monitoring is improved.

[0113] In one embodiment, the receiving processing circuit 120 is further used for sending the coding information to the light curtain transmitting device through the first communication circuit 160 in the receiving state.

[0114] It can be understood that, in order to ensure that the light curtain receiving device and the matched light curtain emitting device are based on the same coding information, the coding information based on which the light curtain receiving device is can be sent to the light curtain emitting device, so that the light curtain emitting device emits the light signal based on the coding information sent by the light curtain receiving device, thereby improving the accuracy of light curtain monitoring.

[0115] In one embodiment, the light curtain receiving device further comprises a first safety indication circuit 170, as shown in the figure, the first safety indication circuit 170 is connected with the receiving processing circuit 120; the receiving processing circuit 120 is further used for controlling the first safety indication circuit 170 to output the first abnormal prompt information if the brightness information of the electric signal is inconsistent with the brightness information of the coding information. Figure 13

[0116] Among them, the first safety indication circuit 170 can include a system indicator light, and the first abnormal prompt information can be a warning light signal emitted by the system indicator light; in addition, the first safety indication circuit 170 can also include a display device, and the first abnormal prompt information can be warning information displayed by the display device.

[0117] Figure 14 The flowchart of the light curtain monitoring method of the light curtain receiving device of one embodiment is shown in the figure, and the monitoring method comprises the following steps:

[0118] Step S101, the receiving processing circuit receives the transmitting end parameter information through the first communication circuit.

[0119] Step S102, the receiving processing circuit controls the first communication circuit to send the receiving end parameter information.

[0120] Step S103, the receiving processing circuit determines whether the transmitting end parameter information is consistent with the receiving end parameter information, if yes, step S105 is executed, otherwise, step S104 is executed.

[0121] Step S104, the light curtain receiving device reports a system error and waits for reset.

[0122] Step S105, the receiving processing circuit sends the coding information to the transmitting end through the first communication circuit.

[0123] Step S106, the receiving processing circuit controls each receiving unit to be turned on in each round of receiving scanning process according to the timing information in the coding information, so that the receiving unit receives the light signal and converts it into an electric signal.

[0124] Step S107, whether the receiving is timed out, if the preset time has not been reached and the light signal has not been received, step S108 is executed, otherwise, step S111 is executed.

[0125] ​Step S108, the receiving processing circuit determines whether the brightness information of the electrical signal is consistent with the brightness information of the encoding information, if consistent, step S109 is executed, otherwise step S111 is executed.

[0126] Step S109, the external output control circuit is controlled to output a normal control signal.

[0127] Step S110, the first safety indication circuit outputs normal working information.

[0128] Step S111, the receiving processing circuit drives the external output control circuit to output an abnormal control signal.

[0129] Step S112, the first communication circuit sends a system control instruction.

[0130] Step S113, the first safety indication circuit outputs first abnormal prompt information.

[0131] The embodiment of the present application also provides a light curtain emitting device, as shown in the drawings. Figure 15 The light curtain emitting device is used for emitting light signals to the light curtain receiving device in any of the above embodiments, and the light curtain emitting device comprises a plurality of light emitting units 210 and an emitting processing circuit 220; the emitting processing circuit 220 is connected with each light emitting unit 210, and is used for controlling each light emitting unit 210 to be lighted in turn in each round receiving scanning process according to the time sequence information and the brightness information in the encoding information in an emitting state, and in the process of controlling the light, each light emitting unit 210 emits light signals with varying brightness in each round receiving scanning process.

[0132] It can be understood that the time sequence information and the brightness information in the encoding information can indicate that the emitting processing circuit 220 lightens each light emitting unit 210 in turn, and makes each light emitting unit 210 emit light signals with varying brightness in each round emitting scanning process, while other light emitting units 210 in the same round emitting scanning process emit light signals with constant brightness, and the light signals with constant brightness can be one of low-brightness light signals, non-light signals or high-brightness light signals; in an embodiment, the emitting processing circuit 220 can control the light emitting unit 210 to emit light signals according to the emitting time sequence in the above embodiment, and the specific light emitting mode can be specified according to the above embodiment. Figure 5 Figure 5

[0133] ​​The aforementioned control of the light-emitting unit 210 to alternately light up and emit light signals with varying brightness via the transmission processing circuit 220 enables the encoding of the light signals, thereby improving the accuracy of light curtain monitoring when performing light curtain monitoring with the light curtain receiving device. In addition, controlling the light-emitting unit 210 to emit light signals with varying brightness in each round of receiving and scanning processes can achieve uniform coverage of high-brightness signals on each light-emitting unit 210, ensuring balanced output and maximizing the lifespan of the light-emitting unit 210.

[0134] In one embodiment, such as Figure 15 As shown, the light-emitting unit 210 includes a light-emitting diode and an emission controller; the first connection terminal of the emission controller is connected to the cathode of the light-emitting diode, and the second connection terminal of the emission controller is connected to the ground terminal; the emission processing circuit 220 includes an emission scanning control unit 221 and an emission control unit 222, the emission scanning control unit 221 being connected to the control terminal of each emission controller respectively; the emission control unit 222 being connected to the emission scanning control unit 221 and the anode of the light-emitting diode respectively, the emission control unit 222 being used to output a brightness control signal to the light-emitting diode according to the brightness information in the encoded information, and to output an emission drive signal to the emission scanning control unit 221 according to the timing information in the encoded information, so as to drive the emission scanning control unit 221 to control the emission controller to conduct the conductive path between the first connection terminal and the second connection terminal, so that the light-emitting diode lights up.

[0135] It can be understood that the transmitter controller can be an N-type MOSFET, its control terminal can be the gate of the MOSFET, the first connection terminal can be the drain, and the second connection terminal can be the source. The transmitter control unit 222 outputs a brightness control signal according to the brightness information in the encoded information, wherein the brightness control signal can be a current signal of a specific magnitude. At the same time, the transmitter control unit 222 drives the transmitter scanning control unit 221 to control the corresponding transmitter controller to turn on according to the encoded information, so that the transmitter control unit 222, the light-emitting diode and the transmitter controller form a conductive circuit. The aforementioned current signal flows through the conductive circuit, and the corresponding light-emitting diode is lit.

[0136] The brightness control signal can be an analog signal, which can be directly provided by the transmission control unit 222; in one embodiment, the brightness control signal can be a digital signal, which can be converted into an analog signal by a conversion circuit after being output by the transmission control unit 222, and then output.

[0137] In one embodiment, the transmit scanning control unit 221 may include a microcontroller and multiple shift registers, and its structure is the same as that of the receive scanning control unit, which can be further referred to. Figure 12The microcontroller is connected with the emission control unit 222 and each shift register respectively, and each shift register is connected in cascade. The shift register can be composed of a plurality of D flip-flops, the output end Q of each D flip-flop is connected with the control end of the emission controller, and is used for outputting the gate control signal. The number of shift registers and the number of D flip-flops can be determined according to the number of the light-emitting unit 210. A plurality of light-emitting units 210 can form a group. The number of shift registers is the same as the number of nodes of the light curtain, and the number of D flip-flops in each shift register is the same as the number of light-emitting units 210 in a single node of the light curtain. Taking an 8-light-emitting-unit 210 node light curtain as an example, one shift register can include 8 D flip-flops. The microcontroller outputs the clock signal CP and the scan control signal DIN to each level of shift register according to the emission driving signal. The output DOUT of the last level of shift register is input to the microcontroller as a feedback signal.

[0138] In one embodiment, the light curtain emission device further comprises a digital-to-analog conversion circuit 230, as shown in Figure 17 The digital-to-analog conversion circuit 230 is connected with the emission control unit 222 and the anode of the light-emitting diode respectively, and is used for converting the brightness control signal from a digital signal to an analog signal.

[0139] It can be understood that the brightness control signal output by the emission control unit 222 can be a digital signal. In order to realize the brightness control of the light-emitting diode, the digital-to-analog conversion circuit 230 can be arranged to process the brightness control signal.

[0140] In one embodiment, the light curtain emission device further comprises a second amplification circuit 240, as shown in Figure 18 The second amplification circuit 240 is connected with the digital-to-analog conversion circuit 230 and the anode of the light-emitting diode respectively, and is used for amplifying the brightness control signal.

[0141] The second amplification circuit 240 can be an integral amplification circuit, which can realize the adjustment of the amplification multiple in a wide range and has a high common-mode rejection ratio. Compared with directly outputting a brightness control signal of a specific size by the emission control unit 222, the additional arrangement of the second amplification circuit 240 can reduce the working load of the emission control unit 222 and improve the reliability of the control action of the emission control unit 222.

[0142] In one embodiment, the light curtain emission device further comprises a second communication circuit 250, as shown in Figure 19 The second communication circuit 250 is connected with the emission processing circuit 220, and is used for receiving the receiving end parameter information sent by the light curtain receiving device and transmitting to the emission processing circuit 220. The emission processing circuit 220 is further used for entering the emission state if the receiving end parameter information is consistent with the emission end parameter information.

[0143] It can be understood that by confirming whether the receiving end parameter information is consistent with the transmitting end parameter information, it can be determined whether the optical curtain transmitting device and the optical curtain receiving device are matched, and if consistent, the two optical curtain devices are matched, and the transmitting processing circuit 220 enters the receiving state, so as to ensure the matching between the optical curtain transmitting device and the optical curtain receiving device, and improve the accuracy of optical curtain monitoring. The transmitting end parameter information and the receiving end parameter information can respectively include the single optical curtain light source bit number, the system total length, etc. The system total length is the optical curtain node number, and the single optical curtain light source bit number is the receiving unit number (for the receiving end) or the photodiode number (for the transmitting end).

[0144] In one embodiment, the second communication circuit 250 is further configured to receive a system control instruction, and transmit the system control instruction to the transmitting processing circuit 220; and the transmitting processing circuit 220 is further configured to exit the transmitting state according to the system control instruction.

[0145] It can be understood that when the optical curtain receiving device exits the receiving state, the system control instruction will be sent at the same time, and the optical curtain transmitting device can receive the system control instruction through the second communication circuit 250, and then the transmitting processing circuit 220 exits the transmitting state according to the system control instruction, so as to ensure that the control optical curtain transmitting device and the matched optical curtain receiving device stop working at the same time, so as to reduce unnecessary energy consumption.

[0146] In one embodiment, the optical curtain transmitting device further comprises a second safety indication circuit 260, as shown in Figure 19 The second safety indication circuit 260 is connected with the transmitting processing circuit 220; and the transmitting processing circuit 220 is further configured to control the second safety indication circuit 260 to output second abnormal prompt information according to the system control instruction.

[0147] It can be understood that in order to inform the staff that there is an abnormality in optical curtain monitoring, the second safety indication circuit 260 can be set to output the second abnormal prompt information. The second safety indication circuit 260 can include a system indicator, and the second abnormal prompt information can be a warning light signal emitted by the system indicator; in addition, the second safety indication circuit 260 can also include a display device, and the second abnormal prompt information can be warning information displayed by the display device.

[0148] In one embodiment, the transmitting processing circuit 220 is further configured to control the second safety indication circuit 260 to output the second abnormal prompt information if the receiving end parameter information is inconsistent with the transmitting end parameter information.

[0149] In one embodiment, the transmitting processing circuit 220 is further configured to send the transmitting end parameter information to the optical curtain receiving device through the second communication circuit 250.

[0150] It can be understood that the transmitting end parameter information can be used by the light curtain receiving device to determine whether it is consistent with the receiving end parameter information, if consistent, it indicates that the light curtain transmitting device and the light curtain receiving device are matched, and then the light signal can be received. Thus, by establishing the communication between the light curtain receiving device and the light curtain transmitting device, the matching confirmation can be performed before the light curtain monitoring, and the accuracy of the light curtain monitoring is improved.

[0151] In one embodiment, the transmitting processing circuit 220 is further configured to receive the encoded information sent by the light curtain receiving device through the second communication circuit 250.

[0152] To ensure that the light curtain transmitting device and the matched light curtain receiving device are based on the same encoded information, the light curtain transmitting device can receive the encoded information sent by the matched light curtain receiving device, so that the light curtain transmitting device transmits the light signal based on the encoded information sent by the light curtain receiving device, and thus the accuracy of the light curtain monitoring is improved.

[0153] Figure 20 The flowchart of the light curtain monitoring method of the light curtain transmitting device of one embodiment is shown. The monitoring method includes the following steps:

[0154] In step S201, the transmitting processing circuit receives the receiving end parameter information through the second communication circuit.

[0155] In step S202, the transmitting processing circuit controls the second communication circuit to send the transmitting end parameter information.

[0156] In step S203, the transmitting processing circuit determines whether the receiving end parameter information is consistent with the transmitting end parameter information, if consistent, step S205 is performed, otherwise step 204 is performed.

[0157] In step S204, the light curtain transmitting device performs system error and waits for reset.

[0158] In step S205, the transmitting processing circuit waits for receiving the signal sent by the light curtain receiving device through the second communication circuit.

[0159] In step S206, the transmitting processing circuit determines whether the signal from the light curtain receiving device is received, if the determination result is yes, step S207 is performed, otherwise step S205 is performed.

[0160] In step S207, the transmitting processing circuit determines whether it is a system control instruction, if the determination result is yes, step S210 is performed, otherwise step S208 is performed.

[0161] In step S208, the transmitting processing circuit determines whether it is encoded information, if the determination result is yes, step S209 is performed, otherwise step S210 is performed.

[0162] Step S209, the emission processing circuit controls the light-emitting units to emit light signals with varying brightness in the receiving scanning process according to the timing information and the brightness information in the encoding information.

[0163] Step S210, the second security indication circuit outputs the second abnormal prompt information.

[0164] It should be understood that, although the steps in the flowcharts of Figure 14 and Figure 20 are shown in sequence according to the arrows, the steps S101 to S113 and the steps S201 to S210 are shown in sequence according to the numbers, these steps are not necessarily executed in sequence according to the arrows or the numbers. Unless otherwise specified herein, the execution of these steps is not strictly limited in sequence, and these steps can be executed in other sequences. Moreover, Figure 14 and Figure 20 at least part of the steps can include multiple steps or multiple stages, which are not necessarily executed at the same time, but can be executed at different times, and the execution sequence of these steps or stages is not necessarily sequential, but can be executed in rotation or alternation with at least part of other steps or steps or stages in other steps.

[0165] The above only describes the preferred embodiments of the present application, and does not limit the patent scope of the present application, and any equivalent structure or equivalent flow transformation using the content of the specification and drawings, or direct or indirect application in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A light curtain receiving device, characterized in that The light curtain receiving device comprises: a plurality of receiving units; an external output control circuit; a receiving processing circuit connected with the external output control circuit and each receiving unit, for controlling each receiving unit to be turned on in turn in each round of receiving scanning process according to time sequence information in the encoding information, so that the receiving unit receives the light signal emitted by the light curtain emitting device and converts the light signal into an electric signal; receiving the electric signal output by the receiving unit, and if the brightness information of the electric signal is consistent with the brightness information of the encoding information, controlling the external output control circuit to output a normal control signal to indicate that the external device is running normally; a current-voltage conversion circuit connected with each receiving unit and the receiving processing circuit, for converting the electric signal from a current signal into a voltage signal; the brightness information of the encoding information comprises a first ordinal number in the current receiving scanning process, and the receiving processing circuit comprises: a first threshold comparator connected with the current-voltage conversion circuit, for comparing the voltage value of the electric signal with a first threshold to generate a first pulse signal; a second threshold comparator connected with the current-voltage conversion circuit, for comparing the voltage value of the electric signal with a second threshold to generate a second pulse signal; a receiving control unit connected with the first threshold comparator, the second threshold comparator and the external output control circuit, for controlling the external output control circuit to output the normal control signal if the second ordinal number of the effective pulse of the first pulse signal corresponds to the first ordinal number; the first threshold is greater than the second threshold. The receiving processing circuit further comprises:

2. The light curtain receiving device of claim 1, wherein, a receiving scanning control unit connected with the receiving control unit and each receiving unit; the receiving control unit is further configured to output a receiving driving signal according to the time sequence information in the encoding information; the receiving scanning control unit is further configured to control each receiving unit to be turned on in turn in each round of receiving scanning process according to the receiving driving signal. The receiving unit comprises:

3. The light curtain receiving device of claim 2, wherein, a photodiode, an anode of the photodiode being connected with a first end of the current-voltage conversion circuit; a receiving controller, a control end of the receiving controller being connected with the receiving scanning control unit, a first connection end of the receiving controller being connected with a cathode of the photodiode, and a second connection end of the receiving controller being connected with a second end of the current-voltage conversion circuit; the receiving scanning control unit is further configured to control the receiving controller to turn on a conductive path between the first connection end and the second connection end according to the receiving driving signal, so that the receiving unit is turned on. The light curtain receiving device further comprises:

4. The light curtain receiving device of claim 3, wherein, a first amplification circuit connected with the current-voltage conversion circuit, the first threshold comparator and the second threshold comparator, for amplifying the electric signal. The light curtain receiving device further comprises:

5. The light curtain receiving device of claim 1, wherein, ​ The first communication circuit is connected with the receiving processing circuit, and is used for receiving the transmission end parameter information transmitted by the light curtain emitting device and transmitting the transmission end parameter information to the receiving processing circuit; The receiving processing circuit is further used for entering the receiving state if the transmission end parameter information is consistent with the receiving end parameter information.

6. The light curtain receiving device of claim 5, wherein, The receiving processing circuit is further used for exiting the receiving state if the brightness information of the electric signal is inconsistent with the brightness information of the encoding information, and sending a system control instruction to the light curtain emitting device through the first communication circuit to instruct the light curtain emitting device to exit the emitting state.

7. The light curtain receiving device of claim 5, wherein, The receiving processing circuit is further used for sending the receiving end parameter information to the light curtain emitting device through the first communication circuit.

8. The light curtain receiving device of claim 5, wherein, The receiving processing circuit is further used for sending the encoding information to the light curtain emitting device through the first communication circuit in the receiving state.

9. The light curtain receiving device of claim 1, wherein, The light curtain receiving device further comprises: A first safety indication circuit connected with the receiving processing circuit; The receiving processing circuit is further used for controlling the first safety indication circuit to output first abnormal prompt information if the brightness information of the electric signal is inconsistent with the brightness information of the encoding information.

10. A light curtain emitting device, characterized by, The light curtain emitting device for emitting light signals to the light curtain receiving device of any one of claims 1 to 9 comprises: A plurality of light emitting units; An emitting processing circuit connected with each of the light emitting units, and used for controlling each of the light emitting units to emit light signals with brightness changes in each of the receiving scanning processes according to the timing information and the brightness information in the encoding information in the emitting state.

11. The light curtain emitting device of claim 10, wherein, The light emitting unit comprises: A light emitting diode; An emitting controller, a first connection end of the emitting controller is connected with a cathode of the light emitting diode, and a second connection end of the emitting controller is connected with a ground end; The emitting processing circuit comprises: An emitting scanning control unit connected with a control end of each of the emitting controllers; An emitting control unit connected with the emitting scanning control unit and an anode of the light emitting diode, and used for outputting a brightness control signal to the light emitting diode according to the brightness information in the encoding information, and outputting an emitting driving signal to the emitting scanning control unit according to the timing information in the encoding information, so as to drive the emitting scanning control unit to control the emitting controller to turn on a conductive path between the first connection end and the second connection end, so that the light emitting diode is lit.

12. The light curtain emitting device of claim 11, wherein, The light curtain emitting device further comprises: A digital-to-analog conversion circuit connected with the emitting control unit and the anode of the light emitting diode, and used for converting the brightness control signal from a digital signal to an analog signal.

13. The light curtain emitting device of claim 12, wherein, The light curtain emitting device further comprises: A second amplification circuit connected with the digital-to-analog conversion circuit and the anode of the light emitting diode, and used for amplifying the brightness control signal.

14. The light curtain emitting device of claim 10, wherein, The light curtain emitting device further comprises: A second communication circuit connected with the emitting processing circuit, and used for receiving receiving end parameter information transmitted by the light curtain receiving device and transmitting the receiving end parameter information to the emitting processing circuit. The transmitting processing circuit is further configured to enter the transmitting state if the receiving end parameter information is consistent with the transmitting end parameter information.

15. The light curtain emitting device of claim 14, wherein, The second communication circuit is further configured to receive a system control instruction and transmit the system control instruction to the transmitting processing circuit. The transmitting processing circuit is further configured to exit the transmitting state according to the system control instruction.

16. The light curtain emitting device of claim 15, wherein, The light curtain transmitting device further comprises: A second safety indication circuit connected with the transmitting processing circuit. The transmitting processing circuit is further configured to control the second safety indication circuit to output second abnormal prompt information according to the system control instruction.

17. The light curtain emitting device of claim 14, wherein, The transmitting processing circuit is further configured to send the transmitting end parameter information to the light curtain receiving device through the second communication circuit.

18. The light curtain emitting device of claim 14, wherein, The transmitting processing circuit is further configured to receive the encoded information sent by the light curtain receiving device through the second communication circuit.

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