Object detection device and object detection system

Abstract

To provide an object detection device and an object detection system with which optical axis is adjustable with good accuracy, yet it is possible to save labor of optical axis adjustment work.SOLUTION: The object detection device includes a plurality of light projection-receiving mechanisms, and each light projection-receiving mechanism comprises a light projection unit and a light receiving unit. The control mode of the light projection control unit is switchable between a first mode for optical axis adjustment work of each light projection unit and each light receiving unit and a second mode for detecting passage of an object. When the control mode of the light projection control unit is the first mode, the light projection control unit controls each light projection unit so that a light projection pattern which is a pattern of light projection by the light projection unit is different for each light projection-receiving mechanism and light projection by a light projection-receiving mechanism is carried out avoiding the timing of light projection by the other light projection-receiving mechanisms.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to an object detection device and an object detection system.

Background Art

[0002] As described in Patent Document 1, an object detection device (referred to as an "infrared detection sensor" in Patent Document 1) including a light projecting and receiving mechanism in two upper and lower stages is known. Generally, in such an object detection device, each light projecting and receiving mechanism has a light projecting unit that projects infrared rays and a light receiving unit that receives the infrared rays projected from the light projecting unit. Then, the passage of an object is detected based on the interruption of the projection of infrared rays from the light projecting unit to the light receiving unit.

Prior Art Document

Patent Document

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Generally, when installing the above-described object detection device, before starting operation, adjustment work of the optical axes of each light projecting unit and each light receiving unit is required. Here, in the object detection device, for example, when pulsed infrared rays are projected from the upper and lower light projecting units, and the waveform of each pulse is the same between the upper light projecting unit and the lower light projecting unit, and the light projection patterns are the same (for example, the periods are the same) between the upper and lower units, it is difficult to identify whether the infrared rays received by the light receiving unit are the infrared rays projected from the upper or lower light projecting unit based on the received infrared rays.

[0005] In this case, during the optical axis adjustment process, it is necessary to stop the light emission from one of the two-tiered light-emitting / receiving mechanisms (e.g., the upper tier) while adjusting the other tier (e.g., the lower tier). In other words, it is not possible to adjust the optical axes of both tiers simultaneously. As a result, the optical axis adjustment process requires a relatively large amount of effort.

[0006] The object of the present invention is to provide an object detection device and object detection system that allows for precise adjustment of the optical axis while reducing the labor required for optical axis adjustment. [Means for solving the problem]

[0007] The object detection device according to the present invention is characterized by comprising a plurality of light-emitting and light-receiving mechanisms, each of which comprises a light-emitting unit that emits infrared light and a light-receiving unit that receives the infrared light emitted from the light-emitting unit, and detects the passage of an object based on the blocking of infrared light emission from the light-emitting unit to the light-receiving unit, and comprises a light-emitting control unit that controls each of the light-emitting units, the control mode of the light-emitting control unit being switchable between a first mode for adjusting the optical axis of each of the light-emitting and light-receiving units and a second mode for detecting the passage of an object, and when the control mode of the light-emitting control unit is the first mode, the light-emitting control unit controls each of the light-emitting units such that the light-emitting pattern, which is the pattern of light emission by the light-emitting unit, is different for each of the light-emitting and light-receiving mechanisms, and the light emission in each light-emitting and light-receiving mechanism is performed while avoiding the timing of light emission in other light-emitting and light-receiving mechanisms. The device comprises a first mechanism, which is a light-emitting and receiving mechanism, and a second mechanism, which is a light-emitting and receiving mechanism different from the first mechanism, wherein the light-emitting period of the light-emitting part in the first mechanism is kept constant, and the light-emitting period of the light-emitting part in the second mechanism is alternately switched between a first period and a second period different from the first period. It is the matter.

[0008] In this configuration, when the control mode of the light emission control unit is in the first mode, the light emission from the light emission and receiving mechanism is performed while avoiding the timing of light emission from other light emission and receiving mechanisms. This prevents a situation where the accuracy of optical axis adjustment is reduced due to the timing of light emission from multiple light emission and receiving mechanisms coinciding.

[0009] Furthermore, with this configuration, when the control mode of the light-emitting control unit is in the first mode, the light emission pattern differs for each light-emitting and receiving mechanism. This makes it possible to identify which light-emitting mechanism's light-emitting unit emitted the infrared light based on the infrared light received by the light-receiving unit. Therefore, during optical axis adjustment work, it is not necessary to stop light emission from the other light-emitting and receiving mechanisms while adjusting the optical axis of one of the multiple light-emitting and receiving mechanisms. In other words, the optical axis adjustment work of multiple light-emitting and receiving mechanisms can be performed simultaneously.

[0010] Therefore, this configuration makes it possible to realize an object detection device that allows for precise adjustment of the optical axis while simultaneously reducing the labor required for optical axis adjustment.

[0011] Furthermore, in the present invention ,before The projection period of the light-emitting unit in the first mechanism is the sum of a first time and a second time that is different from the first time. ,before Preferably, the first period is twice the length of the first time, and the second period is twice the length of the second time.

[0012] This configuration allows for the avoidance of the timing of light emission between the first and second mechanisms, and achieves this with a relatively simple design. As a result, an object detection device with a relatively simple configuration that can precisely adjust the optical axis can be realized.

[0013] Another feature of the object detection device according to the present invention is that it comprises a plurality of light-emitting and light-receiving mechanisms, each of which has a light-emitting unit that emits infrared light and a light-receiving unit that receives the infrared light emitted from the light-emitting unit, and the object detection device detects the passage of an object based on the blocking of infrared light emission from the light-emitting unit to the light-receiving unit, and comprises a light-emitting control unit that controls each of the light-emitting units, the control mode of the light-emitting control unit being switchable between a first mode for adjusting the optical axis of each of the light-emitting and light-receiving units and a second mode for detecting the passage of an object, and when the control mode of the light-emitting control unit is the first mode, the light-emitting control unit controls each of the light-emitting units such that the light-emitting pattern, which is the pattern of light emission by the light-emitting unit, is different for each of the light-emitting and light-receiving mechanisms, and the light emission in each light-emitting and light-receiving mechanism is performed while avoiding the timing of light emission in other light-emitting and light-receiving mechanisms, The light projection control unit is capable of performing a temporary pause control, which is a control that temporarily lengthens the interval between light projections by the light projection unit, and in the first mode, the light projection control unit performs the temporary pause control each time a predetermined first number of light projections are performed, and in the second mode, the temporary pause control is performed each time a predetermined second number of light projections are performed, and the first number and the second number are different from each other. It is .

[0014] In this configuration, when the control mode of the light emission control unit is in the first mode, the light emission from the light emission and receiving mechanism is performed while avoiding the timing of light emission from other light emission and receiving mechanisms. This prevents a situation where the accuracy of optical axis adjustment is reduced due to the timing of light emission from multiple light emission and receiving mechanisms coinciding. Furthermore, with this configuration, when the control mode of the light-emitting control unit is in the first mode, the light emission pattern differs for each light-emitting and receiving mechanism. This makes it possible to identify which light-emitting mechanism's light-emitting unit emitted the infrared light based on the infrared light received by the light-receiving unit. Therefore, during optical axis adjustment work, it is not necessary to stop light emission from the other light-emitting and receiving mechanisms while adjusting the optical axis of one of the multiple light-emitting and receiving mechanisms. In other words, the optical axis adjustment work of multiple light-emitting and receiving mechanisms can be performed simultaneously. Therefore, this configuration makes it possible to realize an object detection device that allows for precise adjustment of the optical axis while simultaneously reducing the labor required for optical axis adjustment. This configuration makes it possible to determine whether the control mode of the light-emitting control unit is the first mode or the second mode based on the infrared light received by the light-receiving unit. Therefore, if a component other than the light-emitting control unit in the object detection device (for example, the light-receiving control unit if one is provided to control the light-receiving unit) is configured to determine the control mode of the light-emitting control unit, there is no need to provide a dedicated component for outputting a signal indicating whether the control mode of the light-emitting control unit is the first mode or the second mode. This makes it easier to reduce manufacturing costs.

[0015] Another feature of the object detection device according to the present invention is that it comprises a plurality of light-emitting and light-receiving mechanisms, each of which has a light-emitting unit that emits infrared light and a light-receiving unit that receives the infrared light emitted from the light-emitting unit, and the object detection device detects the passage of an object based on the blocking of infrared light emission from the light-emitting unit to the light-receiving unit, and comprises a light-emitting control unit that controls each of the light-emitting units, the control mode of the light-emitting control unit being switchable between a first mode for adjusting the optical axis of each of the light-emitting and light-receiving units and a second mode for detecting the passage of an object, and when the control mode of the light-emitting control unit is the first mode, the light-emitting control unit controls each of the light-emitting units such that the light-emitting pattern, which is the pattern of light emission by the light-emitting unit, is different for each of the light-emitting and light-receiving mechanisms, and the light emission in each light-emitting and light-receiving mechanism is performed while avoiding the timing of light emission in other light-emitting and light-receiving mechanisms, An AND mode and an OR mode are provided. In the AND mode, an alarm is triggered when infrared light emission is blocked in all of the plurality of light-emitting and receiving mechanisms. In the OR mode, an alarm is triggered when infrared light emission is blocked in at least one of the plurality of light-emitting and receiving mechanisms. Each light-receiving unit is switchable between a first state in which it can detect light emission from the light-emitting unit and a second state in which it cannot detect light emission from the light-emitting unit. When the control mode of the light-emitting control unit is the second mode, each light-receiving unit is always in the first state in the AND mode, and in the OR mode, each light-receiving unit alternately switches between the first state and the second state in synchronization with the light emission timing of the corresponding light-emitting unit. It is .

[0016] In this configuration, when the control mode of the light emission control unit is in the first mode, the light emission from the light emission and receiving mechanism is performed while avoiding the timing of light emission from other light emission and receiving mechanisms. This prevents a situation where the accuracy of optical axis adjustment is reduced due to the timing of light emission from multiple light emission and receiving mechanisms coinciding. Furthermore, with this configuration, when the control mode of the light-emitting control unit is in the first mode, the light emission pattern differs for each light-emitting and receiving mechanism. This makes it possible to identify which light-emitting mechanism's light-emitting unit emitted the infrared light based on the infrared light received by the light-receiving unit. Therefore, during optical axis adjustment work, it is not necessary to stop light emission from the other light-emitting and receiving mechanisms while adjusting the optical axis of one of the multiple light-emitting and receiving mechanisms. In other words, the optical axis adjustment work of multiple light-emitting and receiving mechanisms can be performed simultaneously. Therefore, this configuration makes it possible to realize an object detection device that allows for precise adjustment of the optical axis while simultaneously reducing the labor required for optical axis adjustment. With this configuration, in AND mode, if infrared light is emitted simultaneously from multiple light emitters, the received intensity of infrared light by each light receiver becomes relatively high. This improves the signal-to-noise ratio in AND mode and makes the system more resistant to false alarms caused by external noise and other factors.

[0017] Also, according to this configuration, in the OR mode, each light-receiving unit alternates between the first state and the second state in synchronization with the light-emitting timing of the corresponding light-emitting unit. Therefore, it is possible to avoid a situation where each light-receiving unit detects light emission by a light-emitting unit other than the corresponding light-emitting unit. As a result, the accuracy of detecting the passage of an object in the OR mode is improved.

[0018] Furthermore, in the present invention, it is preferable that the plurality of light-transmitting and -receiving mechanisms are arranged side by side in the vertical direction and include a light-emitting unit and a light-receiving unit that are installed in a spaced-apart state from each other, each of the light-emitting units is included in the light-emitting unit, and each of the light-receiving units is included in the light-receiving unit.

[0019] According to this configuration, the passage of an object can be detected by a plurality of light-transmitting and -receiving mechanisms having different height positions. As a result, it is easy to avoid a situation where an object slips through the detection range of the object detection device without blocking infrared rays.

[0020] A feature of the object detection system according to the present invention is an object detection system including a plurality of the above-described object detection devices, wherein when the control mode of the light-emitting control unit is the first mode, the light-emitting control unit can control each of the light-emitting units so that the light-emitting pattern is different from that of other object detection devices.

[0021] According to this configuration, the light-emitting pattern when the control mode of the light-emitting control unit is the first mode is different for each object detection device. As a result, it is possible to determine whether the infrared rays received by the light-receiving unit are the infrared rays emitted by the object detection device to which the light-receiving unit belongs based on the infrared rays received by the light-receiving unit.

[0022] Therefore, during the optical axis adjustment operation, it is not necessary to stop the light emission of other object detection devices while adjusting the optical axis of one of the plurality of object detection devices. That is, the optical axis adjustment operations of the plurality of object detection devices can be performed simultaneously.

Brief Description of the Drawings

[0023] [Figure 1] This is a plan view showing the configuration of the object detection system. [Figure 2] This is a front view showing the configuration of the object detection device. [Figure 3] This is a block diagram showing the configuration of an object detection device. [Figure 4] This figure shows the changes in the intensity (output level) of infrared radiation emitted from each light-emitting unit. [Figure 5] This figure shows the changes in the intensity (output level) of infrared radiation emitted from each light-emitting unit and the changes in the state of each light-receiving unit in the first mode. [Figure 6] This figure shows the changes in the intensity (output level) of infrared light emitted from each light-emitting unit and the changes in the state of each light-receiving unit in AND mode. [Modes for carrying out the invention]

[0024] Embodiments for carrying out the present invention will be described with reference to the drawings. In the following description, unless otherwise specified, the direction of arrow U in the drawings will be considered "up" and the direction of arrow D will be considered "down".

[0025] [Configuration of the object detection system] As shown in Figure 1, the object detection system A in this embodiment includes a plurality of object detection devices 1. More specifically, the object detection system A in this embodiment includes four object detection devices 1. However, the present invention is not limited thereto. The number of object detection devices 1 included in the object detection system A may be three or fewer, or five or more.

[0026] The object detection device 1 comprises a light-emitting unit 2 and a light-receiving unit 3. The light-emitting unit 2 and the light-receiving unit 3 are installed spaced apart from each other. That is, the object detection device 1 comprises a light-emitting unit 2 and a light-receiving unit 3 installed spaced apart from each other. Each object detection device 1 has the same configuration.

[0027] The light-emitting unit 2 emits infrared light 4. The light-receiving unit 3 receives the infrared light 4 emitted from the light-emitting unit 2.

[0028] Multiple object detection devices 1 are arranged around a predetermined area 5 in a plan view. In the example shown in Figure 1, the multiple object detection devices 1 are arranged such that the entire perimeter (four sides) of the predetermined area 5 is surrounded by multiple infrared rays 4 in a plan view. However, the present invention is not limited to this. The multiple object detection devices 1 may be arranged in any way.

[0029] The designated area 5 is not particularly limited, but may include, for example, a restricted access area, a protected area, a building, etc.

[0030] [Configuration of the object detection device] As shown in Figure 2, the object detection device 1 is equipped with multiple light-emitting and receiving mechanisms 6. More specifically, the object detection device 1 is equipped with a first mechanism 11 and a second mechanism 12. Both the first mechanism 11 and the second mechanism 12 are light-emitting and receiving mechanisms 6. That is, the object detection device 1 is equipped with a first mechanism 11 which is a light-emitting and receiving mechanism 6, and a second mechanism 12 which is a light-emitting and receiving mechanism 6 different from the first mechanism 11.

[0031] As shown in Figure 2, the first mechanism 11 is located at the top of the object detection device 1. The second mechanism 12 is located at the bottom of the object detection device 1. In this way, the multiple light-emitting and receiving mechanisms 6 are arranged vertically.

[0032] In this embodiment, the object detection device 1 is equipped with two light-emitting / receiving mechanisms 6, one above the other. However, the present invention is not limited to this. The number of light-emitting / receiving mechanisms 6 equipped in the object detection device 1 may be any number.

[0033] Each light-emitting / receiving mechanism 6 has a light-emitting unit 7 and a light-receiving unit 8. The light-emitting unit 7 emits infrared rays 4. The light-receiving unit 8 receives the infrared rays 4 emitted from the light-emitting unit 7. That is, each light-emitting / receiving mechanism 6 has a light-emitting unit 7 that emits infrared rays 4 and a light-receiving unit 8 that receives the infrared rays 4 emitted from the light-emitting unit 7. The object detection device 1 detects the passage of an object based on the interruption of the emission of infrared rays 4 from the light-emitting unit 7 to the light-receiving unit 8.

[0034] The objects whose passage is detected are not particularly limited, but may include, for example, an intruder.

[0035] As shown in Figure 2, the first mechanism 11 has an upper light-emitting unit 71 and an upper light-receiving unit 81. The upper light-emitting unit 71 and the upper light-receiving unit 81 face each other. The upper light-emitting unit 71 is the light-emitting unit 7. The upper light-receiving unit 81 is the light-receiving unit 8 corresponding to the upper light-emitting unit 71. That is, the upper light-emitting unit 71 emits infrared rays 4 toward the upper light-receiving unit 81. The upper light-receiving unit 81 then receives the infrared rays 4 emitted from the upper light-emitting unit 71.

[0036] The second mechanism 12 has a lower light-emitting unit 72 and a lower light-receiving unit 82. The lower light-emitting unit 72 and the lower light-receiving unit 82 face each other. The lower light-emitting unit 72 is the light-emitting unit 7. The lower light-receiving unit 82 is the light-receiving unit 8 corresponding to the lower light-emitting unit 72. That is, the lower light-emitting unit 72 emits infrared rays 4 toward the lower light-receiving unit 82. The lower light-receiving unit 82 then receives the infrared rays 4 emitted from the lower light-emitting unit 72.

[0037] The upper light-emitting section 71 and the lower light-emitting section 72 are included in the light-emitting unit 2. The upper light-receiving section 81 and the lower light-receiving section 82 are included in the light-receiving unit 3. In other words, each light-emitting section 7 is included in the light-emitting unit 2, and each light-receiving section 8 is included in the light-receiving unit 3.

[0038] The light-emitting unit 2 has a light-emitting body 21 and a light-emitting cover 22. The upper light-emitting section 71 and the lower light-emitting section 72 are provided on the light-emitting body 21. The light-emitting cover 22 is made of resin and is configured to cover the upper light-emitting section 71 and the lower light-emitting section 72. The light-emitting cover 22 is detachable from the light-emitting body 21. Infrared rays 4 pass through the light-emitting cover 22.

[0039] The light receiving unit 3 has a light receiving body 31 and a light receiving cover 32. The upper light receiving section 81 and the lower light receiving section 82 are provided on the light receiving body 31. The light receiving cover 32 is made of resin and is configured to cover the upper light receiving section 81 and the lower light receiving section 82. The light receiving cover 32 is detachable from the light receiving body 31. Infrared rays 4 pass through the light receiving cover 32.

[0040] [Control Mode] As shown in Figure 3, the light-emitting unit 2 (more specifically, the light-emitting main body 21) has a light-emitting control unit 23 and a light-emitting mode switching unit 24. The light-emitting control unit 23 controls each light-emitting unit 7 (more specifically, the upper light-emitting unit 71 and the lower light-emitting unit 72). In other words, the object detection device 1 is equipped with a light-emitting control unit 23 that controls each light-emitting unit 7.

[0041] The control mode of the light projection control unit 23 is switchable between a first mode and a second mode. The first mode is a control mode for adjusting the optical axis of each light projection unit 7 and each light receiving unit 8. The second mode is a control mode for detecting the passage of an object. In other words, the control mode of the light projection control unit 23 is switchable between a first mode for adjusting the optical axis of each light projection unit 7 and each light receiving unit 8, and a second mode for detecting the passage of an object.

[0042] The light-emitting mode switching unit 24 is configured to switch the control mode of the light-emitting control unit 23. More specifically, the light-emitting mode switching unit 24 is configured to detect the attachment or detachment of the light-emitting cover 22.

[0043] Furthermore, when the light-emitting mode switching unit 24 detects that the light-emitting cover 22 has been removed from the light-emitting main unit 21, it switches the control mode of the light-emitting control unit 23 from the second mode to the first mode. Also, when the light-emitting mode switching unit 24 detects that the light-emitting cover 22 has been attached to the light-emitting main unit 21, it switches the control mode of the light-emitting control unit 23 from the first mode to the second mode.

[0044] However, the present invention is not limited thereto. The control mode of the light projection control unit 23 may be switched independently of the attachment or detachment of the light projection cover 22. For example, the control mode of the light projection control unit 23 may be switched by manually operating a switch (not shown).

[0045] As shown in Figure 3, the light receiving unit 3 (more specifically the light receiving main body 31) has a light receiving control unit 33 and a light receiving side mode switching unit 34. The light receiving control unit 33 controls each light receiving unit 8 (more specifically the upper light receiving unit 81 and the lower light receiving unit 82).

[0046] The control mode of the light receiving control unit 33 can be switched between the first mode and the second mode, similar to the light transmitting control unit 23.

[0047] The light-receiving mode switching unit 34 is configured to switch the control mode of the light-receiving control unit 33. More specifically, the light-receiving mode switching unit 34 determines the control mode of the light-emitting control unit 23 and automatically switches the control mode of the light-receiving control unit 33 according to the control mode of the light-emitting control unit 23. More specifically, when the control mode of the light-emitting control unit 23 switches from the second mode to the first mode, the light-receiving mode switching unit 34 switches the control mode of the light-receiving control unit 33 from the second mode to the first mode. Also, when the control mode of the light-emitting control unit 23 switches from the first mode to the second mode, the light-receiving mode switching unit 34 switches the control mode of the light-receiving control unit 33 from the first mode to the second mode.

[0048] In other words, the light-receiving mode switching unit 34 switches the control mode of the light-receiving control unit 33 to match the control mode of the light-emitting control unit 23.

[0049] Here, the determination of the control mode of the light-emitting control unit 23 by the light-receiving mode switching unit 34 will be described in detail. The light-emitting control unit 23 controls each light-emitting unit 7 so that the intensity (output level) of the infrared rays 4 emitted from each light-emitting unit 7 becomes pulsed as shown in Figure 4. The light-emitting control unit 23 is also capable of performing temporary pause control. Temporary pause control is a control that temporarily lengthens the interval between light emission by each light-emitting unit 7. In other words, the light-emitting control unit 23 is capable of performing temporary pause control, which is a control that temporarily lengthens the interval between light emission by the light-emitting units 7. In this specification, one pulse is assumed to be one light emission.

[0050] As shown in Figure 4, the light emission control unit 23 pauses the light emission once after a predetermined number of (N) times the light is emitted. As a result, the interval between the last light emission of the predetermined number of (N) times and the first light emission of the next predetermined number of (N) times is longer than the interval between lights emitted in the predetermined number of (N) times. In other words, the temporary pause control in this embodiment is a control that pauses the light emission once.

[0051] In the first mode, the light emission control unit 23 performs a temporary pause control after a predetermined first number of light emission cycles, and in the second mode, it performs a temporary pause control after a predetermined second number of light emission cycles. The first and second number of cycles are different from each other.

[0052] For example, "N" shown in Figure 4 represents the first count in the first mode and the second count in the second mode. The first and second counts can be any number, as long as they are different from each other.

[0053] As shown in Figure 3, the light-receiving mode switching unit 34 acquires the detection result of the infrared radiation 4 (light emitted from the light-emitting unit 7) received by the upper light-receiving unit 81. The light-receiving mode switching unit 34 also acquires the detection result of the infrared radiation 4 (light emitted from the light-emitting unit 7) received by the lower light-receiving unit 82.

[0054] The light-receiving mode switching unit 34 then detects the interval of temporary pause control based on the detection results of the infrared rays 4 (light emitted from the light-emitting unit 7) received by each light-receiving unit 8 (in other words, the upper light-receiving unit 81 and the lower light-receiving unit 82). That is, the light-receiving mode switching unit 34 detects how many times light has been emitted between the execution of one temporary pause control and the execution of the next temporary pause control. Based on this, the light-receiving mode switching unit 34 determines the control mode of the light-emitting control unit 23.

[0055] For example, if the upper light receiving unit 81 detects that the interval between temporary pause controls is the first time (in other words, that after a temporary pause control is executed, the first number of light emission operations have occurred before the next temporary pause control is executed), the light receiving mode switching unit 34 determines that the control mode of the light emission control unit 23 is the first mode.

[0056] However, the present invention is not limited thereto. The control mode of the light receiving control unit 33 may be switched manually. For example, the control mode of the light receiving control unit 33 may be switched by manually operating a switch (not shown).

[0057] As shown in Figure 3, the light receiving unit 3 has an alarm generating unit 35. The alarm generating unit 35 acquires the detection result of infrared radiation 4 (light emitted from the light emitting unit 7) received by the upper light receiving unit 81 from the upper light receiving unit 81. The alarm generating unit 35 also acquires the detection result of infrared radiation 4 (light emitted from the light emitting unit 7) received by the lower light receiving unit 82 from the lower light receiving unit 82.

[0058] The alarm generation unit 35 generates an alarm based on the detection result of infrared rays 4 (light emitted by the light emitter 7) received by each light receiving unit 8 (in other words, the upper light receiving unit 81 and the lower light receiving unit 82). In this embodiment, the alarm generated by the alarm generation unit 35 is the output of an alarm signal to an alarm device (not shown). When the alarm device receives the alarm signal, it notifies that the passage of an object has been detected by sound, light, etc. The alarm device may or may not be included in the object detection device 1.

[0059] However, the present invention is not limited thereto. The alarm issued by the alarm unit 35 may also be a notification of the detection of an object's passage, such as by sound or light. In other words, the alarm unit 35 may be configured to emit sound or light.

[0060] Furthermore, the object detection device 1 detects the passage of an object only when the light emission control unit 23 and the light receiving control unit 33 are in the second mode. More specifically, the alarm is issued by the alarm unit 35 only when the light emission control unit 23 and the light receiving control unit 33 are in the second mode.

[0061] In other words, the object detection device 1 does not detect the passage of an object when the light emission control unit 23 and the light receiving control unit 33 are in the first mode. More specifically, the alarm issuing unit 35 does not issue an alarm when the light emission control unit 23 and the light receiving control unit 33 are in the first mode. However, the present invention is not limited thereto. The object detection device 1 detects the passage of an object, and the alarm issuing unit 35 may also be performed when the light emission control unit 23 and the light receiving control unit 33 are in the first mode. This allows for an operational test to be performed in the first mode to confirm that the detection of object passage and the alarm issuing are functioning correctly. This operational test may also be performed by connecting a tester or the like for detection confirmation to the alarm issuing unit 35, so that the alarm signal from the alarm issuing unit 35 is output to the tester or the like instead of the alarm issuing device.

[0062] [Operating Mode] The object detection device 1 has two operating modes: AND mode and OR mode. That is, the object detection device 1 is provided with AND mode and OR mode.

[0063] As shown in Figure 3, both the light-emitting unit 2 (more specifically the light-emitting main body 21) and the light-receiving unit 3 (more specifically the light-receiving main body 31) have an operation mode setting unit 9. The operation mode setting unit 9 sets the operation mode of the object detection device 1 (in other words, the light-emitting unit 2 and the light-receiving unit 3) in response to human operation. Although not particularly limited, the operation mode setting unit 9 may set the operation mode based, for example, on human operation of a setting switch (not shown).

[0064] When the object detection device 1 is in AND mode, and the light emission control unit 23 and the light receiving control unit 33 are in the second mode, the alarm unit 35 will issue an alarm if the emission of infrared 4 is blocked in both the first mechanism 11 and the second mechanism 12. However, if the emission of infrared 4 is blocked in only one of the first mechanism 11 or the second mechanism 12, the alarm unit 35 will not issue an alarm.

[0065] In other words, in AND mode, an alarm is triggered when the infrared light 4 is blocked in all of the multiple light-emitting and receiving mechanisms 6.

[0066] When the object detection device 1 is in OR mode, and the light emission control unit 23 and the light receiving control unit 33 are in the second mode, the alarm unit 35 will issue an alarm if the emission of infrared light 4 is interrupted in at least one of the first mechanism 11 and the second mechanism 12.

[0067] In other words, in OR mode, an alarm is triggered when the emission of infrared light 4 is interrupted in at least one of the multiple light-emitting / receiving mechanisms 6.

[0068] Furthermore, the light emission control unit 23, the light emission mode switching unit 24, the light receiving control unit 33, the light receiving mode switching unit 34, the alarm generation unit 35, and the operation mode setting unit 9 may be physical devices such as microcomputers, or they may be functional units in software.

[0069] [Light projection control in Mode 1] When the control mode of the light projection control unit 23 is the first mode, the light projection control unit 23 controls each light projection unit 7 so that the light projection pattern differs for each light projection and receiving mechanism 6, as shown in Figure 5. The light projection pattern refers to the pattern of light projected by the light projection unit 7.

[0070] More specifically, in Figure 5, the "upper light projection" shows the change in the intensity (output level) of the infrared radiation 4 emitted from the upper light projection unit 71 in the first mode. The "lower light projection" shows the change in the intensity (output level) of the infrared radiation 4 emitted from the lower light projection unit 72 in the first mode.

[0071] As shown in Figure 5, the light projection pattern from the lower light projection unit 72 is a pattern in which the light projection period is alternately switched between the first period T1 and the second period T2. That is, the light projection period of the light projection unit 7 in the second mechanism 12 is alternately switched between the first period T1 and the second period T2. Note that the first period T1 and the second period T2 are different from each other.

[0072] Furthermore, the light projection pattern from the upper light projection unit 71 is a pattern in which the light projection period remains at the third period T3.

[0073] Thus, in this embodiment, when the control mode of the light emission control unit 23 is the first mode, the light emission pattern differs for each light emission and receiving mechanism 6.

[0074] Furthermore, in this embodiment, when the control mode of the light projection control unit 23 is the first mode, the light projection control unit 23 can control each light projection unit 7 so that the light projection pattern is different from that of the other object detection devices 1. More specifically, for example, the light projection control unit 23 may also be able to control each light projection unit 7 so that the light projection period is different from that of the other object detection devices 1.

[0075] Furthermore, for example, it may be possible to individually select a light projection pattern from among multiple light projection patterns for each object detection device 1. In this case, if a different light projection pattern is selected for each object detection device 1, the light projection control unit 23 in each object detection device 1 will control each light projection unit 7 so that the light projection pattern is different from that of the other object detection devices 1.

[0076] Furthermore, when the control mode of the light emission control unit 23 is the first mode, the light emission control unit 23 controls each light emission unit 7 so that the light emission in the light emission and receiving mechanism 6 is performed while avoiding the timing of light emission in the other light emission and receiving mechanisms 6, as shown in Figure 5.

[0077] More specifically, as shown in Figure 5, the first period T1 is twice the length of the first time T4. Similarly, the second period T2 is twice the length of the second time T5. Note that the first time T4 and the second time T5 are distinct from each other.

[0078] Furthermore, the third period T3 is the sum of the first time T4 and the second time T5. That is, the projection period of the light-emitting unit 7 in the first mechanism 11 is the sum of the first time T4 and the second time T5, which is different from the first time T4.

[0079] By defining the first period T1, the second period T2, and the third period T3 in this manner, and by staggering the timing of the first light emission in each light-emitting / receiving mechanism 6, the light emission in one light-emitting / receiving mechanism 6 will occur while avoiding the timing of the light emission in the other light-emitting / receiving mechanisms 6. This "first light emission" may be the first light emission after the power of the object detection device 1 is turned on, or it may be the first light emission after the control mode of the light emission control unit 23 becomes the first mode.

[0080] In other words, when the control mode of the light projection control unit 23 is the first mode, the light projection control unit 23 controls each light projection unit 7 such that the light projection pattern, which is the pattern of light projected by the light projection unit 7, is different for each light projection and receiving mechanism 6, and that the light projection in the light projection and receiving mechanism 6 is performed while avoiding the timing of light projection in the other light projection and receiving mechanisms 6.

[0081] [Switching the state of the light receiving unit] The light receiving control unit 33 can switch the state of each light receiving unit 8 between a first state and a second state. The first state is a state in which the light emitted from the light emitting unit 7 can be detected. The second state is a state in which the light emitted from the light emitting unit 7 cannot be detected. In other words, each light receiving unit 8 can switch between a first state in which the light emitted from the light emitting unit 7 can be detected and a second state in which the light emitted from the light emitting unit 7 cannot be detected.

[0082] More specifically, in Figure 5, the "upper light receiving section" shows the state transition of the upper light receiving section 81 in the first mode. The "lower light receiving section" shows the state transition of the lower light receiving section 82 in the first mode. In the graphs for the "upper light receiving section" and "lower light receiving section" in Figure 5, "ON" corresponds to the first state, and "OFF" corresponds to the second state.

[0083] As shown in Figure 5, in the first mode, the upper light receiving unit 81 enters a first state in conjunction with the light emission timing of the upper light emitting unit 71, and enters a second state when the upper light emitting unit 71 is not emitting light.

[0084] Furthermore, in the first mode, the lower light receiving unit 82 enters a first state in accordance with the light emission timing of the lower light emitting unit 72, and enters a second state when the lower light emitting unit 72 is not emitting light.

[0085] In this way, each light-receiving unit 8 alternately switches between a first state and a second state in synchronization with the light emission timing of the corresponding light-emitting unit 7 in the first mode.

[0086] Furthermore, when the object detection device 1 is in OR mode, and the light emission control unit 23 and light receiving control unit 33 are in the second mode, each light emission unit 7 and each light receiving unit 8 are controlled in the same way as when in the first mode, except for the temporary pause control described above. That is, when the object detection device 1 is in OR mode, and the light emission control unit 23 and light receiving control unit 33 are in the second mode, each light emission unit 7 and each light receiving unit 8 are controlled as shown in Figure 5.

[0087] When the object detection device 1 is in AND mode, and the light emission control unit 23 and the light receiving control unit 33 are in the second mode, the light emission unit 7 and the light receiving unit 8 are controlled as shown in Figure 6. Hereinafter, the control of the light emission unit 7 and the light receiving unit 8 in this state will be referred to as "AND mode control".

[0088] In Figure 6, the transition of the intensity (output level) of infrared rays 4 emitted from the upper light-emitting unit 71 and the lower light-emitting unit 72 in AND mode control is shown as "common to upper and lower light-emitting units".

[0089] In AND mode control, the upper light-emitting unit 71 and the lower light-emitting unit 72 emit light at the same timing. Furthermore, in AND mode control, the light emission occurs at the same timing as the upper light-emitting unit 71 in OR mode, and also at the same timing as the lower light-emitting unit 72 in OR mode. As a result, the frequency of light emission increases compared to OR mode.

[0090] More specifically, as shown in Figure 6, the projection period in AND mode control changes so that it repeats as "second time T5, first time T4, first time T4, second time T5".

[0091] Furthermore, Figure 6 shows the state transitions of the upper light receiving unit 81 and the lower light receiving unit 82 in AND mode control, labeled as "Common to upper and lower light receiving units". In the graph for "Common to upper and lower light receiving units" in Figure 6, "ON" corresponds to the first state and "OFF" corresponds to the second state.

[0092] As shown in Figure 6, in AND mode control, the upper light receiving unit 81 and the lower light receiving unit 82 are always in the first state.

[0093] In other words, when the control mode of the light emission control unit 23 is the second mode, in AND mode each light receiving unit 8 is always in the first state, and in OR mode each light receiving unit 8 alternately switches between the first state and the second state in synchronization with the light emission timing of the corresponding light emission unit 7.

[0094] [Regarding synchronization] The following describes in detail the control that synchronizes the state switching of the light receiving unit 8 with the light emission timing of the light emission unit 7 when the light emission control unit 23 and the light receiving control unit 33 are switched to the first mode.

[0095] In this embodiment, the upper light receiving unit 81 is configured to receive not only infrared rays 4 from the upper light emitting unit 71, but also infrared rays 4 emitted from the lower light emitting unit 72 and spread out in a fan shape. Similarly, the lower light receiving unit 82 is configured to receive not only infrared rays 4 from the lower light emitting unit 72, but also infrared rays 4 emitted from the upper light emitting unit 71 and spread out in a fan shape. However, the present invention is not limited to these configurations. The upper light receiving unit 81 may be configured so that infrared rays 4 from the lower light emitting unit 72 do not reach (are not received). Similarly, the lower light receiving unit 82 may be configured so that infrared rays 4 from the upper light emitting unit 71 do not reach (are not received).

[0096] When the light receiving control unit 33 is switched to the first mode, the light receiving control unit 33 executes synchronization start control. Synchronization start control is a control that starts the state switching of each light receiving unit 8 in synchronization with the light emission timing of each light emission unit 7. In other words, synchronization start control is a control that starts the synchronization of the light emission timing of each light emission unit 7 and the state switching of each light receiving unit 8.

[0097] In synchronous start control, as shown in Figure 3, the light receiving control unit 33 acquires the detection result of infrared 4 received by the upper light receiving unit 81 from the upper light receiving unit 81. At this time, the upper light receiving unit 81 receives not only infrared 4 from the upper light transmitting unit 71 but also infrared 4 from the lower light transmitting unit 72.

[0098] Based on the detection result, the light receiving control unit 33 identifies the infrared 4 (pulse) with a reception period of the third period T3. The light receiving control unit 33 then identifies the infrared 4 as the infrared 4 emitted from the upper light emitting unit 71. The light receiving control unit 33 then starts switching the state of the upper light receiving unit 81 to synchronize with the reception period of the infrared 4. This synchronizes the state switching of the upper light receiving unit 81 with the emission timing of the upper light emitting unit 71.

[0099] Furthermore, the upper light receiving unit 81 may remain in the first state at all times from the moment the light receiving control unit 33 enters the first mode until the state switching of the upper light receiving unit 81, which is synchronized with the light emission timing of the upper light transmitting unit 71, begins.

[0100] Furthermore, in synchronized start control, as shown in Figure 3, the light receiving control unit 33 acquires the detection result of infrared 4 received by the lower light receiving unit 82 from the lower light receiving unit 82. At this time, the lower light receiving unit 82 receives not only infrared 4 from the lower light transmitting unit 72 but also infrared 4 from the upper light transmitting unit 71.

[0101] Based on the detection result, the light receiving control unit 33 identifies infrared radiation 4 (pulses) whose reception period alternates between the first period T1 and the second period T2. The light receiving control unit 33 then identifies this infrared radiation 4 as infrared radiation 4 emitted from the lower light emitting unit 72. The light receiving control unit 33 then starts switching the state of the lower light receiving unit 82 in synchronization with the reception period of the infrared radiation 4. This synchronizes the state switching of the lower light receiving unit 82 with the emission timing of the lower light emitting unit 72.

[0102] Furthermore, the lower light receiver 82 may remain in the first state at all times from the moment the light receiving control unit 33 enters the first mode until the state switching of the lower light receiving unit 82, which is synchronized with the light emission timing of the lower light emission unit 72, begins.

[0103] The synchronization start control ends when the state switching of the upper light receiving unit 81, which is synchronized with the light emission timing of the upper light emitting unit 71, and the state switching of the lower light receiving unit 82, which is synchronized with the light emission timing of the lower light emitting unit 72, begin.

[0104] After the synchronization start control is completed, each light receiving unit 8 will detect light emitted from the corresponding light transmitting unit 7, while light emitted from the non-corresponding light transmitting unit 7 will not be detected. Therefore, the optical axis adjustment work of multiple light transmitting and receiving mechanisms 6 can be performed simultaneously without stopping the light emission of each light transmitting and receiving mechanism 6.

[0105] Furthermore, the object detection device 1 may be provided with multiple indicators (not shown) corresponding to multiple light receiving units 8. These indicators may be configured to show the intensity (input level) of the infrared radiation 4 received by the corresponding light receiving unit 8 during the optical axis adjustment process. These indicators may be provided, for example, on the light receiving unit 3. The user can perform the optical axis adjustment process effectively by observing these indicators.

[0106] According to the configuration described above, when the control mode of the light emission control unit 23 is the first mode, the light emission from the light emission and receiving mechanism 6 is performed while avoiding the timing of light emission from other light emission and receiving mechanisms 6. This prevents a situation in which the accuracy of optical axis adjustment is reduced due to the timing of light emission from multiple light emission and receiving mechanisms 6 coinciding.

[0107] Furthermore, with the configuration described above, when the control mode of the light emission control unit 23 is the first mode, the light emission pattern differs for each light emission and receiving mechanism 6. This makes it possible to identify which light emission unit 7 of which light emission and receiving mechanism 6 emitted the infrared radiation 4 received by the light receiving unit 8. Therefore, during optical axis adjustment work, it is not necessary to stop light emission from the other light emission and receiving mechanisms 6 while adjusting the optical axis of one of the multiple light emission and receiving mechanisms 6. In other words, the optical axis adjustment work of multiple light emission and receiving mechanisms 6 can be performed simultaneously.

[0108] Therefore, with the configuration described above, it is possible to realize an object detection device 1 that allows for precise adjustment of the optical axis while also reducing the labor required for optical axis adjustment.

[0109] [Other Embodiments] (1) A single light-emitting unit 7 may have multiple light-emitting elements. That is, a single light-emitting unit 7 may emit multiple infrared rays 4. In that case, a single light-receiving unit 8 may have multiple light-receiving elements.

[0110] (2) In the above embodiment, when the light projection control unit 23 is in the first mode, the light projection period in the first mechanism 11 and the second mechanism 12 is defined by a combination of two types of time, a first time T4 and a second time T5. However, the present invention is not limited thereto. The light projection period may be defined by, for example, a combination of three types of time, or it may be set randomly.

[0111] (3) The configuration may not include the execution of temporary pause control.

[0112] (4) The first mechanism 11 may be located at the bottom of the object detection device 1, and the second mechanism 12 may be located at the top of the object detection device 1.

[0113] (5) It is not necessary for either AND mode or OR mode to be provided.

[0114] (6) The multiple light-emitting and receiving mechanisms 6 do not have to be arranged in the vertical direction.

[0115] Furthermore, the configurations disclosed in the above-described embodiments (including other embodiments, the same applies hereinafter) can be applied in combination with configurations disclosed in other embodiments, as long as no inconsistencies arise. In addition, the embodiments disclosed herein are illustrative, and the embodiments of the present invention are not limited thereto, and can be modified as appropriate without departing from the object of the present invention. [Industrial applicability]

[0116] The present invention is applicable to object detection devices and object detection systems. [Explanation of Symbols]

[0117] 1: Object detection device 2: Floodlight unit 3: Light receiving unit 4: Infrared 6: Light emitting and receiving mechanism 7: Lighting unit 8: Light receiving part 11: 1st mechanism 12:Second mechanism 23: Light Projection Control Unit A: Object detection system T1: 1st period T2: 2nd period T4: 1st hour T5: 2nd hour

Claims

1. Equipped with multiple light transmission and reception mechanisms, Each of the above-mentioned light-emitting and light-receiving mechanisms includes a light-emitting unit that emits infrared light and a light-receiving unit that receives the infrared light emitted from the light-emitting unit. An object detection device that detects the passage of an object based on the blocking of infrared light emission from the light-emitting unit to the light-receiving unit, Each of the aforementioned light-emitting units is equipped with a light-emitting control unit, The control mode of the light projection control unit is switchable between a first mode for adjusting the optical axis of each light projection unit and each light receiving unit, and a second mode for detecting the passage of an object. When the control mode of the light-emitting control unit is the first mode, the light-emitting control unit controls each of the light-emitting units such that the light-emitting pattern, which is the pattern of light emitted by the light-emitting unit, is different for each of the light-emitting and receiving mechanisms, and that the light emission in each light-emitting and receiving mechanism is performed while avoiding the timing of light emission in other light-emitting and receiving mechanisms. The system comprises a first mechanism which is a light-emitting and light-receiving mechanism, and a second mechanism which is a light-emitting and light-receiving mechanism different from the first mechanism. The light emission period of the light-emitting unit in the first mechanism is maintained at a constant level. An object detection device in which the light emission period of the light emission unit in the second mechanism is alternately switched between a first period and a second period different from the first period.

2. The light emission period of the light-emitting unit in the first mechanism is the sum of a first time and a second time different from the first time, The first period is twice the length of the first time, The object detection device according to claim 1, wherein the second period is twice the length of the second time.

3. comprising multiple light transmission and reception mechanisms, Each of the above-mentioned light-emitting and light-receiving mechanisms includes a light-emitting unit that emits infrared light and a light-receiving unit that receives the infrared light emitted from the light-emitting unit. An object detection device that detects the passage of an object based on the blocking of infrared light emission from the light-emitting unit to the light-receiving unit, Each of the aforementioned light-emitting units is equipped with a light-emitting control unit, The control mode of the light projection control unit is switchable between a first mode for adjusting the optical axis of each light projection unit and each light receiving unit, and a second mode for detecting the passage of an object. When the control mode of the light-emitting control unit is the first mode, the light-emitting control unit controls each of the light-emitting units such that the light-emitting pattern, which is the pattern of light emitted by the light-emitting unit, is different for each of the light-emitting and receiving mechanisms, and that the light emission in each light-emitting and receiving mechanism is performed while avoiding the timing of light emission in other light-emitting and receiving mechanisms. The light projection control unit is capable of performing a temporary pause control, which is a control that temporarily lengthens the interval between light projections by the light projection unit. The light projection control unit executes the temporary pause control each time a predetermined first number of light projections are performed in the first mode, and executes the temporary pause control each time a predetermined second number of light projections are performed in the second mode. The first count and the second count are different object detection devices.

4. comprising multiple light transmission and reception mechanisms, Each of the above-mentioned light-emitting and light-receiving mechanisms includes a light-emitting unit that emits infrared light and a light-receiving unit that receives the infrared light emitted from the light-emitting unit. An object detection device that detects the passage of an object based on the blocking of infrared light emission from the light-emitting unit to the light-receiving unit, Each of the aforementioned light-emitting units is equipped with a light-emitting control unit, The control mode of the light projection control unit is switchable between a first mode for adjusting the optical axis of each light projection unit and each light receiving unit, and a second mode for detecting the passage of an object. When the control mode of the light-emitting control unit is the first mode, the light-emitting control unit controls each of the light-emitting units such that the light-emitting pattern, which is the pattern of light emitted by the light-emitting unit, is different for each of the light-emitting and receiving mechanisms, and that the light emission in each light-emitting and receiving mechanism is performed while avoiding the timing of light emission in other light-emitting and receiving mechanisms. Android mode and OR mode are provided. In the aforementioned AND mode, an alarm is triggered when infrared light emission is blocked in all of the multiple light-emitting and receiving mechanisms. In the above-mentioned OR mode, an alarm is triggered when the emission of infrared light is blocked in at least one of the multiple light-emitting and light-receiving mechanisms. Each of the light-receiving units is switchable between a first state in which it can detect the light emitted from the light-emitting unit and a second state in which it cannot detect the light emitted from the light-emitting unit. An object detection device in which, when the control mode of the light-emitting control unit is the second mode, each of the light-receiving units is always in the first state in the AND mode, and in the OR mode, each of the light-receiving units alternately switches between the first state and the second state in synchronization with the light-emitting timing of the corresponding light-emitting unit.

5. The aforementioned multiple light-emitting and light-receiving mechanisms are arranged in the vertical direction. It comprises a light-emitting unit and a light-receiving unit that are installed at a distance from each other. Each of the aforementioned light-emitting units is included in the light-emitting unit, The object detection device according to any one of claims 1 to 4, wherein each of the light receiving units is included in the light receiving unit.

6. An object detection system comprising a plurality of object detection devices according to any one of claims 1 to 4, An object detection system in which, when the control mode of the light projection control unit is the first mode, the light projection control unit can control each of the light projection units such that the light projection pattern is different from that of other object detection devices.

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