Passive infrared detector

Abstract

The application provides a passive infrared detector, which comprises: a first Pyro for receiving infrared radiation of a target in a detection area and converting the received infrared radiation into an electrical signal; a second Pyro for receiving infrared radiation of a target in a detection area and converting the received infrared radiation into an electrical signal; an optical system for dividing the detection area of the first Pyro into a plurality of first detection sub-zones and dividing the detection area of the second Pyro into a plurality of second detection sub-zones; and an optical system shielding device for shielding the optical system in a first state and shielding part of the area corresponding to the target Pyro in the optical system in a second state. The passive infrared detector can effectively reduce the occurrence of false alarms while ensuring the detection rate, and is compatible with the application requirements of different hanging height states of the passive infrared detector.

Description

Technical Field

[0001] This application relates to the field of security intrusion alarms, and more particularly to a passive infrared detector. Background Technology

[0002] Passive infrared detectors, also known as PIR (Passive Infrared) detectors, mainly use a lens unit at the front end to collect infrared signals from the human body within the protected area and converge the signals to a pyroelectric passive infrared sensor (Pyro for short). Combined with the function of the pyroelectric infrared sensor to convert infrared signals into electrical signals, when a human body intrudes, the temperature of the intruding human body changes compared to the ambient background temperature. The passive infrared detector senses this change and will issue an alarm signal.

[0003] However, in practice, it has been found that when pets such as cats and dogs enter the protected area of ​​a passive infrared detector, it may cause the passive infrared detector to trigger a false alarm. Summary of the Invention

[0004] In view of this, this application provides a passive infrared detector.

[0005] According to a first aspect of the embodiments of this application, a passive infrared detector is provided, comprising: a first Pyro, a second Pyro, an optical system, and an optical system blocking device; wherein:

[0006] The first Pyro is used to receive infrared radiation from targets within the detection area and convert the received infrared radiation into electrical signals.

[0007] The second Pyro is used to receive infrared radiation from targets within the detection area and convert the received infrared radiation into electrical signals.

[0008] An optical system is used to divide the detection area of ​​the first Pyro into multiple first detection partitions, and to divide the detection area of ​​the second Pyro into multiple second detection partitions.

[0009] An optical system blocking device is used to not block the optical system in a first state, and to block a portion of the region corresponding to the target Pyro in the optical system in a second state.

[0010] Wherein, when the optical system shielding device is in the first state, the plurality of first detection zones and the plurality of second detection zones are continuously and alternately distributed from high to low and from far to near within the protection zone of the passive infrared detector; within the protection zone, the number of first detection zones cut by a first type of target is greater than or equal to the number of first detection zones cut by a second type of target, the number of second detection zones cut by a first type of target is greater than or equal to the number of second detection zones cut by a second type of target, and the total number of first and second detection zones cut by a first type of target is greater than the total number of first and second detection zones cut by a second type of target;

[0011] When the optical system shielding device is in the second state, there are no target detection zones with a height lower than the third height within the defense zone;

[0012] The target Pyro is the first Pyro, and the target detection partition is the first detection partition; or, the target Pyro is the second Pyro, and the target detection partition is the second detection partition;

[0013] The first type of target is a target with an altitude higher than the first altitude, and the second type of target is a target with an altitude lower than the second altitude, wherein the first altitude is greater than or equal to the second altitude;

[0014] The third height is less than or equal to the first height, and the third height is greater than or equal to the second height.

[0015] For example, when the optical system blocking device is in the first state, within the protected area, the number of the first detection partitions cut by the first type of target is greater than or equal to 2, and the number of the second detection partitions cut by the first type of target is greater than or equal to 2.

[0016] The number of the first detection partitions of the second type of target is less than or equal to 1, and the number of the second detection partitions of the first type of target is less than or equal to 1, and the total number of the first detection partitions and the second detection partitions of the second type of target is greater than or equal to 1.

[0017] For example, when the optical system blocking device is in the second state, the number of target detection zones within the defense zone is 1.

[0018] For example, when the passive infrared detector is installed at a fourth height, the optical system blocking device is in a first state; when the passive infrared detector is installed at a fifth height, the optical system blocking device is in a second state.

[0019] Wherein, the fourth height is greater than the first height, and the fifth height is greater than the second height but less than the first height.

[0020] For example, the optical system includes an assembly of optical elements that, based on the principles of reflection and / or refraction, divide a first Pyro detection region into a plurality of first detection partitions, and divide a second Pyro detection region into a plurality of second detection partitions.

[0021] For example, the optical element assembly includes a multi-layer partitioned Fresnel lens array;

[0022] The multi-layer partitioned Fresnel lens array includes a first region corresponding to the first Pyro and a second region corresponding to the second Pyro.

[0023] The first region of the multi-layer partitioned Fresnel lens array is used to divide the first Pyro detection region into multiple first detection partitions.

[0024] The second region of the multi-layer partitioned Fresnel lens array is used to divide the second Pyro detection region into multiple second detection partitions.

[0025] For example, the passive infrared detector also includes: a status recognition button;

[0026] When the optical system blocking device is in the first state, the status recognition button is in the released state; when the optical system blocking device is in the second state, the status recognition button is in the connected state.

[0027] For example, a passive infrared detector may also include a threshold circuit;

[0028] When the status recognition button is in the released state and the on state, the threshold circuit sets different alarm thresholds for the first Pyro, and / or, when the status recognition button is in the released state and the on state, the threshold circuit sets different alarm thresholds for the second Pyro.

[0029] According to a second aspect of the embodiments of this application, a passive infrared detector is provided, comprising: a first pyroelectric infrared sensor, a second pyroelectric infrared sensor, and an optical system; wherein:

[0030] The first pyroelectric infrared sensor is used to receive infrared radiation from targets within the detection area and convert the received infrared radiation into electrical signals.

[0031] The second pyroelectric infrared sensor is used to receive infrared radiation from targets within the detection area and convert the received infrared radiation into electrical signals.

[0032] An optical system is used to divide the detection area of ​​a first pyroelectric infrared sensor into multiple first detection zones, and to divide the detection area of ​​a second pyroelectric infrared sensor into multiple second detection zones.

[0033] The plurality of first detection zones and the plurality of second detection zones are continuously and alternately distributed from high to low and from far to near within the protection zone of the passive infrared detector;

[0034] Within the defense zone, the number of first detection zones cut by the first type of target is greater than or equal to the number of first detection zones cut by the second type of target, the number of second detection zones cut by the first type of target is greater than or equal to the number of second detection zones cut by the second type of target, the total number of first and second detection zones cut by the first type of target is greater than the total number of first and second detection zones cut by the second type of target; the total number of first and second detection zones cut by the second type of target is greater than or equal to 1.

[0035] The first type of target is a target with a height higher than the first height, and the second type of target is a target with a height lower than the second height, wherein the first height is greater than or equal to the second height.

[0036] For example, the passive infrared detector further includes: an optical system blocking device; wherein:

[0037] When the optical system blocking device is in the first state, the optical system is not blocked;

[0038] When the optical system blocking device is in the second state, it blocks a portion of the area of ​​the corresponding target pyroelectric infrared sensor in the optical system, so that there are no target detection zones with a height lower than the third height within the defense zone.

[0039] The target pyroelectric infrared sensor is the first pyroelectric infrared sensor, and the target detection zone is the first detection zone; or, the target pyroelectric infrared sensor is the second pyroelectric infrared sensor, and the target detection zone is the second detection zone;

[0040] The third height is less than or equal to the first height, and the third height is greater than or equal to the second height.

[0041] For example, when the passive infrared detector is installed in a first height range, the optical system blocking device is in a first state; when the passive infrared detector is installed in a second height range, the optical system blocking device is in a second state.

[0042] Wherein, the lower limit of the first height range is greater than the first height, the upper limit of the second height range is less than the first height, and the lower limit of the second height range is greater than the second height.

[0043] For example, when the passive infrared detector is installed in the second height range and the installation height is higher than the fourth height, the optical system blocking device is in the second state, and there are at least two target detection zones with heights higher than or equal to the third height within the defense zone;

[0044] When the passive infrared detector is installed in the second height range and the installation height is lower than the fifth height, the optical system blocking device is in the second state, and the number of target detection zones within the defense zone is 1.

[0045] The fourth height is greater than the fifth height.

[0046] For example, the optical element assembly includes a multi-layer partitioned Fresnel lens array;

[0047] The multi-layer partitioned Fresnel lens array includes a first region corresponding to the first pyroelectric infrared sensor and a second region corresponding to the second pyroelectric infrared sensor.

[0048] The first region of the multi-layer partitioned Fresnel lens array is used to divide the detection area of ​​the first pyroelectric infrared sensor into multiple first detection partitions.

[0049] The second region of the multi-layer partitioned Fresnel lens array is used to divide the detection area of ​​the second pyroelectric infrared sensor into multiple second detection partitions.

[0050] For example, the passive infrared detector also includes: a status recognition button and a threshold circuit;

[0051] When the optical system blocking device is in the first state, the status recognition button is in the released state; when the optical system blocking device is in the second state, the status recognition button is in the connected state.

[0052] When the status recognition button is in the released state and the on state, the threshold circuit sets different alarm thresholds for the first pyroelectric infrared sensor, and / or, when the status recognition button is in the released state and the on state, the threshold circuit sets different alarm thresholds for the second pyroelectric infrared sensor.

[0053] According to a third aspect of the embodiments of this application, a passive infrared detector is provided, comprising: a first pyroelectric infrared sensor, a second pyroelectric infrared sensor, an optical system, and an optical system blocking device; wherein:

[0054] The first pyroelectric infrared sensor is used to receive infrared radiation from targets within the detection area and convert the received infrared radiation into electrical signals.

[0055] The second pyroelectric infrared sensor is used to receive infrared radiation from targets within the detection area and convert the received infrared radiation into electrical signals.

[0056] An optical system is used to divide the detection area of ​​a first pyroelectric infrared sensor into multiple first detection zones, and to divide the detection area of ​​a second pyroelectric infrared sensor into multiple second detection zones.

[0057] The first pyroelectric infrared sensor is located above the second pyroelectric infrared sensor, and the rotation axis of the optical system blocking device is located below the second pyroelectric infrared sensor. Along a direction perpendicular to the arrangement of the first and second pyroelectric infrared sensors, the movable end of the optical system blocking device is located between the optical system and the second pyroelectric infrared sensor. During the rotation of the optical system blocking device, the highest point of the movable end of the optical system blocking device is less than the highest point of the second optical system partition. The optical system blocking device can either block part of the plurality of second detection partitions or not block the plurality of second detection partitions by rotating. The second optical system partition is used to divide the detection area of ​​the second pyroelectric infrared sensor into multiple second detection partitions.

[0058] The passive infrared detector of this application embodiment, by setting a first pyro, a second pyro, and an optical system, divides the detection area of ​​the first pyro into multiple first detection zones and the detection area of ​​the second pyro into multiple second detection zones through the optical system, and sets an optical system blocking device, by blocking or not blocking the optical system in different states, so as to change the distribution of the first and second detection zones within the protection area of ​​the passive infrared detector, so as to be compatible with the application requirements of the passive infrared detector in different mounting height states. With the optical system's blocking device in its first state, the first and second detection zones are continuously and alternately distributed from high to low and from far to near within the passive infrared detector's protection zone. Within the protection zone, the number of first detection zones cut by a first-type target is greater than or equal to the number of first detection zones cut by a second-type target, and the number of second detection zones cut by a first-type target is greater than or equal to the number of second detection zones cut by a second-type target. The total number of first and second detection zones cut by a first-type target is greater than the total number of first and second detection zones cut by a second-type target. Therefore, by setting appropriate alarm thresholds for the first and second Pyro, it can be effectively ensured that the first-type target triggers the passive infrared detection. The system performs alarm processing and prevents second-type targets from triggering false alarms in the passive infrared detector. While ensuring the detection rate, it effectively reduces the occurrence of false alarms. When the optical system's blocking device is in the second state, there are no target detection zones with a height lower than the third height within the protected area. Second-type targets entering the protected area cannot cut into the target detection zone, while first-type targets can cut into the first and second detection zones. Therefore, by setting appropriate alarm thresholds for the first and second Pyro, it is possible to effectively ensure that first-type targets trigger the passive infrared detector for alarm processing and prevent second-type targets from triggering false alarms in the passive infrared detector. This effectively reduces the occurrence of false alarms while ensuring the detection rate. Attached Figure Description

[0059] Figure 1 This is a schematic diagram of the structure of a passive infrared detector provided in an embodiment of this application;

[0060] Figure 2A This is a schematic diagram of the detection zone distribution when the optical system blocking device is in a first state, as provided in an embodiment of this application;

[0061] Figure 2B This is a schematic diagram of the detection zone distribution when the optical system blocking device is in a second state, as provided in an embodiment of this application;

[0062] Figure 2CThis is a schematic diagram of the traditional PIR detection defense zone distribution;

[0063] Figure 3 This is a schematic diagram of another passive infrared detector provided in an embodiment of this application;

[0064] Figure 4 This is a schematic diagram of another passive infrared detector provided in an embodiment of this application;

[0065] Figure 5 This is a schematic diagram of the structure of a passive infrared detector provided in an embodiment of this application;

[0066] Figure 6 This is a schematic diagram of another passive infrared detector provided in an embodiment of this application;

[0067] Figure 7 This is a schematic diagram of another passive infrared detector provided in an embodiment of this application;

[0068] Figure 8 This is a schematic diagram of a multi-layer partitioned Fresnel lens array in a PIR detector provided in an embodiment of this application;

[0069] Figure 9 This is a schematic diagram of the Pyro detection field of view under different mounting heights provided in the embodiments of this application;

[0070] Figure 10 This is a structural diagram of the optical system lensmask and status recognition button provided in the embodiments of this application. Detailed Implementation

[0071] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0072] The terminology used in this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The singular forms “a,” “the,” and “the” used in this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0073] To enable those skilled in the art to better understand the technical solutions provided in the embodiments of this application, and to make the above-mentioned objectives, features and advantages of the embodiments of this application more apparent and understandable, the technical solutions in the embodiments of this application will be further described in detail below with reference to the accompanying drawings.

[0074] Please see Figure 1 This is a schematic diagram of the structure of a passive infrared detector provided in an embodiment of this application, as shown below. Figure 1 As shown, the passive infrared detector may include: a first Pyro 110, a second Pyro 120, an optical system 130, and an optical system blocking device 140; wherein:

[0075] The first Pyro110 is used to receive infrared radiation from targets within the detection area and convert the received infrared radiation into electrical signals.

[0076] The second Pyro120 is used to receive infrared radiation from targets within the detection area and convert the received infrared radiation into electrical signals.

[0077] Optical system 130 is used to divide the detection area of ​​the first Pyro into a plurality of first detection partitions, and to divide the detection area of ​​the second Pyro into a plurality of second detection partitions.

[0078] The optical system blocking device 140 is used to not block the optical system 130 in the first state, and to block a portion of the region of the optical system 130 corresponding to the target Pyro in the second state.

[0079] It should be noted that, Figure 1 , Figure 3 as well as Figure 4 The examples only illustrate the structural components of a passive infrared detector, without specifying the positions of the components.

[0080] For example, when the optical system blocking device 140 is in the first state, the aforementioned plurality of first detection zones and plurality of second detection zones are evenly and alternately distributed from high to low and from far to near within the protection zone of the passive infrared detector.

[0081] Within the defense zone of the passive infrared detector, the number of first detection zones cut by the first type of target is less than or equal to the number of first detection zones cut by the second type of target, the number of second detection zones cut by the first type of target is less than or equal to the number of second detection zones cut by the second type of target, and the total number of first and second detection zones cut by the first type of target is less than the total number of first and second detection zones cut by the second type of target.

[0082] For example, when the optical system blocking device 140 is in the second state, there is no target detection zone with a height lower than the third height within the protection zone of the passive infrared detector;

[0083] The target Pyro is the first Pyro, and the target detection partition is the first detection partition; or, the target Pyro is the second Pyro, and the target detection partition is the second detection partition.

[0084] The first type of target is a target whose altitude is higher than the first altitude threshold, and the second type of target is a target whose altitude is lower than the second altitude threshold. The first altitude threshold is greater than or equal to the second altitude threshold.

[0085] The third altitude is less than or equal to the first altitude, and the third altitude is greater than or equal to the second altitude.

[0086] In this embodiment of the application, in order to reduce the occurrence of false alarms by the passive infrared detector, the passive infrared detector can adopt a dual Pyro structure (which can be referred to as the first Pyro and the second Pyro, respectively), and the detection areas of the first Pyro and the second Pyro can be divided into multiple detection zones by an optical system (the detection zone obtained by dividing the detection area of ​​the first Pyro can be referred to as the first detection zone, and the detection zone obtained by dividing the detection area of ​​the second Pyro can be referred to as the first detection zone).

[0087] In addition, to ensure the compatibility of passive infrared detectors with different mounting heights, the passive infrared detector may also include an optical system blocking device. When the passive infrared detector is mounted at different heights, the optical system blocking device can be in different states to change the distribution of the first detection zone and the second detection zone within the protection zone of the passive infrared detector. This allows the passive infrared detector to distinguish targets (such as people or pets) at different heights under different mounting heights, reducing the occurrence of false alarms.

[0088] For example, when the passive infrared detector is in a high-mounted state (also known as a high-mounted-high state), the optical system blocking device can be set to a first state; when the passive infrared detector is in a low-mounted state (also known as a low-mounted-high state), the optical system blocking device can be set to a second state.

[0089] In this embodiment, when the optical system blocking device is in the first state, the aforementioned plurality of first detection zones and plurality of second detection zones can be evenly and alternately distributed from high to low and from far to near within the protection zone of the passive infrared detector. For example, when the optical system blocking device is in the first state, taking an example where there are 7 first detection zones and 7 second detection zones each, the distribution of the first and second detection zones within the protection zone of the passive infrared detector can be seen in [reference needed]. Figure 2A .like Figure 2A As shown, P1H1~PIH7 is the first detection zone, and P2H1~P2H7 is the second detection zone. The first and second detection zones are evenly distributed from high to low and from far to near the ground within the protection zone of the passive infrared detector.

[0090] In this embodiment, when the optical system blocking device is in the first state, such as when the passive infrared detector is in the high-mounted state, through the above-mentioned setting of detection zones, for a target (which can be called a first type target) whose height exceeds a preset height (which can be called a first height), when it enters the defense zone, the number of first detection zones that can be cut (i.e., the number of first detection zones that can detect the target, the same below) and the number of second detection zones are not less than the number of first detection zones and the number of second detection zones cut by a target (which can be called a second type target) whose height is lower than the preset height (which can be called a second height) within the defense zone. Moreover, the total number of detection zones cut by the first type target (the sum of the number of first detection zones and the number of second detection zones) is greater than the total number of detection zones cut by the second type target. Therefore, the first type target enters the defense zone. When a target of type 1 enters the protected area, the electrical signal output by the first Pyro can be greater than the electrical signal output by the second Pyro when the target of type 2 enters the protected area, and / or the electrical signal output by the second Pyro when the target of type 1 enters the protected area can be greater than the electrical signal output by the second Pyro when the target of type 2 enters the protected area. By setting an appropriate alarm threshold, when the target of type 1 enters the protected area, the electrical signals output by both the first Pyro and the second Pyro will exceed the alarm threshold, while when the target of type 2 enters the protected area, the electrical signals output by the first Pyro and / or the second Pyro will not exceed the alarm threshold. That is, the target of type 1 can trigger the passive infrared detector to perform alarm processing, while the target of type 2 will not trigger the passive infrared detector to perform alarm processing. While ensuring the detection rate, the occurrence of false alarms is effectively reduced.

[0091] For example, for a target entering the defense zone, the more first detection zones it cuts, the greater the energy of the electrical signal that triggers the first Pyro output; the more second detection zones it cuts, the greater the energy of the electrical signal that triggers the second Pyro output.

[0092] In one example, when the optical system blocking device is in the first state, within the defense zone, the number of first detection zones and the number of second detection zones cut by the first type of target are both greater than or equal to 2; the number of first detection zones and the number of second detection zones cut by the second type of target are both less than or equal to 1, and the total number of first detection zones and second detection zones cut by the second type of target is greater than or equal to 1, that is, the second type of target can cut 1 first detection zone and / or 1 second detection zone.

[0093] For example, with Figure 2A Taking the detection partition distribution shown as an example, for the first type of target (such as...) Figure 2A (The human body in the middle), which can cut the signals of the two detection partitions P1H1 and P1H2 of Pyro1, and cut the signals of the two detection partitions P2H2 and P2H3 of Pyro2.

[0094] For example, the first height and the second height can be set according to empirical values ​​of the height of the target to be detected and empirical values ​​of the target height to avoid triggering false alarms.

[0095] For example, the purpose of deploying a passive infrared detector is to detect human beings entering the protected area. However, to avoid false alarms triggered by pets such as cats and dogs, the aforementioned first and second heights can be set based on the empirical values ​​of human height and the heights of pets such as cats and dogs.

[0096] In this embodiment of the application, when the optical system blocking device is in the second state, there is no target detection zone with a height lower than the third height within the defense zone of the passive infrared detector.

[0097] For example, considering that the passive infrared detector is deployed at a relatively low position, such as when the passive infrared detector is in a low-mounted high state, if the detection zones are distributed as described above, the second type of target may also be cut into multiple first detection zones and multiple second detection zones. As a result, the passive infrared detector may not be able to distinguish between the first type of target and the second type of target, leading to a higher probability of false alarms.

[0098] Correspondingly, when the passive infrared detector is in a low-mounted-high state, the optical system blocking device can be set to a second state. In this state, the optical system blocking device can block a portion of the area corresponding to the target Pyro in the optical system, so that there are no target detection zones with a height lower than the preset height (which can be called the third height) within the passive infrared detector's defense zone.

[0099] For example, when the optical system's blocking device is in its second state, the distribution of the first and second detection zones within the protected area can be seen in [reference needed]. Figure 2B,like Figure 2B As shown, Pyro2 can retain only the highest probe partition, while Pyro1 retains all probe partitions.

[0100] For example, the target Pyro can be either a first Pyro or a second Pyro.

[0101] For example, when the target Pyro is the first Pyro, the above target detection partition is the first detection partition; when the target Pyro is the second Pyro, the above target detection partition is the second detection partition.

[0102] Since the optical system's blocking device is in the second state, there are no target detection zones with heights lower than the third height within the passive infrared detector's protection zone. Therefore, the second type of target will not be detected by the target Pyro within the protection zone, meaning that the electrical signal output by the target Pyro will not trigger the alarm condition, which can effectively reduce false alarms.

[0103] For the first type of target, after it enters the defense zone, it can still cut through the detection zones of the first Pyro and the second Pyro, so that the electrical signals output by the first Pyro and the second Pyro can both meet the alarm conditions, thereby triggering the passive infrared detector to perform alarm processing.

[0104] In one example, with the optical system blocking device in the second state, the optical system blocking device is located between the optical system and the target Pyro.

[0105] For example, since the field of view of the target Pyro after processing by the optical system is diffused, the closer to the target Pyro, the smaller the area covered by its field of view. Therefore, compared with the case where the optical system blocking device is located outside the optical system, the blocking method where the optical system blocking device is located between the optical system and the target Pyro can achieve similar blocking requirements with a smaller area of ​​optical system blocking device.

[0106] Accordingly, in order to save materials for the optical system shielding device, the optical system shielding device is in the second state, and the optical system shielding device can be located between the optical system and the target Pyro.

[0107] For example, one end of the optical system blocking device can be fixedly mounted on one side of the target Pyro, such as the upper or lower side, and the other end can rotate around the fixed end to switch between a first state and a second state.

[0108] When the optical system blocking device is in the second state, the active end of the optical system blocking device (i.e. the end used for blocking) can block the field of view corresponding to the target detection zone with a height lower than the third height according to the blocking requirements.

[0109] For example, when the optical system blocking device is in the second state, the smaller the distance between the movable end of the optical system blocking device and the target Pyro, the smaller the area of ​​the optical system blocking device required for the same blocking requirement. In addition, when the optical system blocking device is in the first state, the optical system blocking device needs to be hidden (e.g., not blocking the field of view of the target Pyro). Reducing the area of ​​the optical system blocking device can reduce the space required to hide the optical system blocking device.

[0110] Accordingly, the movable end of the optical system blocking device can be set as an arc-shaped structure instead of a planar structure. When the optical system blocking device is in the second state, the protruding part faces the optical system to further reduce the area of ​​the optical system blocking device and save the space occupied by the optical system blocking device. Its schematic diagram can be shown as follows. Figure 9 As shown. In one example, with the optical system blocking device in the second state, the number of target detection zones within the protected area is 1.

[0111] For example, taking the target detection zone as the first detection zone, when the optical system blocking device is in the second state, the optical system blocking device can block part of the area corresponding to the first Pyro in the optical system, so that the number of the first detection zone in the defense zone is 1, and the height of the first detection zone is higher than or equal to the third height. Thus, when the first type of target enters the defense zone, it can cut through the first detection zone and the second detection zone, and when the second type of target enters the defense zone, it cannot cut through the first detection zone.

[0112] It can be seen that, in Figure 1The passive infrared detector shown herein comprises a first pyro, a second pyro, and an optical system. The optical system divides the detection area of ​​the first pyro into multiple first detection zones and the detection area of ​​the second pyro into multiple second detection zones. An optical system blocking device is provided, which blocks or does not block the optical system under different conditions to change the distribution of the first and second detection zones within the passive infrared detector's protection zone, thereby accommodating the application requirements of the passive infrared detector under different mounting heights. With the optical system's blocking device in its first state, the first and second detection zones are continuously and alternately distributed from high to low and from far to near within the passive infrared detector's protection zone. Within the protection zone, the number of first detection zones cut by a first-type target is greater than or equal to the number of first detection zones cut by a second-type target, and the number of second detection zones cut by a first-type target is greater than or equal to the number of second detection zones cut by a second-type target. The total number of first and second detection zones cut by a first-type target is greater than the total number of first and second detection zones cut by a second-type target. Therefore, by setting appropriate alarm thresholds for the first and second Pyro, it can be effectively ensured that the first-type target triggers the passive infrared detection. The system performs alarm processing and prevents second-type targets from triggering false alarms in the passive infrared detector. While ensuring the detection rate, it effectively reduces the occurrence of false alarms. When the optical system's blocking device is in the second state, there are no target detection zones with a height lower than the third height within the protected area. Second-type targets entering the protected area cannot cut into the target detection zone, while first-type targets can cut into the first and second detection zones. Therefore, by setting appropriate alarm thresholds for the first and second Pyro, it is possible to effectively ensure that first-type targets trigger the passive infrared detector for alarm processing and prevent second-type targets from triggering false alarms in the passive infrared detector. This effectively reduces the occurrence of false alarms while ensuring the detection rate.

[0113] In some embodiments, when the passive infrared detector is installed in a first height range, the optical system blocking device is in a first state; when the passive infrared detector is installed in a second height range, the optical system blocking device is in a second state.

[0114] Among them, the lower limit of the first height range is greater than the first height, the upper limit of the second height range is less than the first height, and the lower limit of the second height range is greater than the second height.

[0115] For example, suppose the first height is H1, the second height is H2, the range of the first height is [H11, H12], and the range of the second height is [H21, H22], then H12 > H1, H21 < H1, and H22 > H2.

[0116] For example, consider a passive infrared detector with its height in the high-mounted state within the first height range and its height in the low-mounted state within the second height range.

[0117] When the passive infrared detector is installed within a first altitude range, the optical system blocking device is in its first state and does not block the optical system. In this case, multiple first detection zones and multiple second detection zones are continuously and alternately distributed from high to low and from far to near within the passive infrared detector's protection zone. For example, its schematic diagram can be as follows: Figure 2A As shown.

[0118] When the passive infrared detector is installed at the second altitude, the optical system blocking device is in its second state, blocking a portion of the area corresponding to the target Pyro within the optical system. In this case, there are no target detection zones with altitudes lower than the third altitude within the protected area. For example, a schematic diagram could be shown below. Figure 2B As shown.

[0119] In some embodiments, the optical system 130 may include an optical element assembly that can divide the first Pyro detection region into a plurality of first detection partitions and the second Pyro detection region into a plurality of second detection partitions based on the principles of reflection and / or refraction.

[0120] For example, an optical element assembly can be provided in a passive infrared detector, and the optical element assembly can be used to divide the detection area of ​​the first Pyro into multiple first detection zones based on the principles of reflection and / or refraction, and the detection zone of the second Pyro can be divided into multiple second detection zones.

[0121] For example, the aforementioned optical element assembly can be disposed in front of the first Pyro and the second Pyro to adjust the detectable area of ​​the first Pyro and the second Pyro within the protection zone (i.e., the aforementioned first detection zone and second detection zone).

[0122] For targets that enter the defense zone and cut through the first detection zone, the infrared radiation they emit can be received by the first Pyro after reflection and / or refraction by the aforementioned combination of optical elements; for targets that enter the defense zone but do not cut through the first detection zone, the infrared radiation they emit cannot be received by the first Pyro after reflection and / or refraction by the aforementioned combination of optical elements.

[0123] Similarly, for targets that enter the defense zone and cut through the second detection zone, the infrared radiation they emit can be received by the second Pyro after reflection and / or refraction by the aforementioned combination of optical elements; for targets that enter the defense zone but do not cut through the second detection zone, the infrared radiation they emit cannot be received by the second Pyro after reflection and / or refraction by the aforementioned combination of optical elements.

[0124] In one example, the above optical element combination may include a multi-layer partitioned Fresnel lens array;

[0125] The multi-layer partitioned Fresnel lens array includes a first region corresponding to the first Pyro and a second region corresponding to the second Pyro;

[0126] The first region of the multi-layer partitioned Fresnel lens array is used to divide the first Pyro detection region into multiple first detection partitions;

[0127] The second region of the multi-layer partitioned Fresnel lens array is used to divide the second Pyro detection region into multiple second detection partitions.

[0128] For example, the detectable area of ​​the first Pyro and the second Pyro within the defense zone can be adjusted by a multi-layered partitioned Fresnel lens array.

[0129] For example, a multi-layer partitioned Fresnel lens array may include a region corresponding to a first Pyro (which may be referred to as the first region) and a region corresponding to a second Pyro (which may be referred to as the second region).

[0130] The first region of the multi-layer partitioned Fresnel lens array is used to divide the first Pyro detection region into multiple first detection regions, and the second region of the multi-layer partitioned Fresnel lens array is used to divide the second Pyro detection region into multiple second detection regions.

[0131] In some embodiments, such as Figure 3 As shown, the passive infrared detector may also include: a status recognition button 150;

[0132] When the optical system blocking device 140 is in the first state, the status recognition button 150 is in the released state; when the optical system blocking device 140 is in the second state, the status recognition button 150 is in the connected state.

[0133] For example, in order to more accurately control the optical system blocking device 140 to be in different states to adapt to different hanging height states of the passive infrared detector, a state recognition button can also be set in the passive infrared detector, which can be linked with the optical system blocking device.

[0134] When the optical system blocking device is in the first state, the status recognition button is in the released state; when the optical system blocking device is in the second state, the status recognition button is in the connected state.

[0135] In one example, such as Figure 4 As shown, the passive infrared detector may further include: a threshold circuit 160; wherein:

[0136] When the status recognition button is in the released state and the on state, the threshold circuit sets different alarm thresholds for the first Pyro, and / or, when the status recognition button is in the released state and the on state, the threshold circuit sets different alarm thresholds for the second Pyro.

[0137] For example, considering that the optical system blocking device is in different states (such as the first state or the second state), the distribution of the first and second detection zones within the protected area will differ significantly. For instance, the detection zone distributions in the first and second states of the optical system blocking device can be as follows: Figure 2A and 2B As shown, when a first-type target or a second-type target enters the defense zone, the way they cut the detection zone will also differ, resulting in differences in the energy of the electrical signals that trigger the output of the first Pyro and the second Pyro.

[0138] To ensure the detection rate of the first type of target, different alarm thresholds can be set for the first Pyro and / or the second Pyro when the optical system blocking device is in the first state and when the optical system blocking device is in the second state.

[0139] Accordingly, the passive infrared detector may also include a threshold circuit for setting an alarm threshold for the first Pyro and / or the second Pyro.

[0140] For example, the threshold circuit and the optical system's blocking device can be linked through a status recognition button.

[0141] When the status recognition button is in the released state and the on state, that is, when the optical system blocking device is in the first state and the second state, the threshold circuit can set different alarm thresholds for the first Pyro, and / or the threshold circuit can set different alarm thresholds for the second Pyro.

[0142] Please see Figure 5 This is a schematic diagram of the structure of a passive infrared detector provided in an embodiment of this application, as shown below. Figure 5 As shown, the passive infrared detector may include: a first Pyro510, a second Pyro520, and an optical system 530; wherein:

[0143] The first Pyro510 is used to receive infrared radiation from targets within the detection area and convert the received infrared radiation into electrical signals.

[0144] The second Pyro520 is used to receive infrared radiation from targets within the detection area and convert the received infrared radiation into electrical signals.

[0145] Optical system 530 is used to divide the detection area of ​​the first Pyro into multiple first detection partitions, and to divide the detection area of ​​the second Pyro into multiple second detection partitions.

[0146] It should be noted that, Figures 5-7 The examples only illustrate the structural components of a passive infrared detector, without specifying the positions of the components.

[0147] For example, the aforementioned multiple first detection zones and multiple second detection zones are continuously and alternately distributed from high to low and from far to near within the defense zone of the passive infrared detector;

[0148] Within the defense zone, the number of first detection zones cut by the first type of target is greater than or equal to the number of first detection zones cut by the second type of target, the number of second detection zones cut by the first type of target is greater than or equal to the number of second detection zones cut by the second type of target, and the total number of first and second detection zones cut by the first type of target is greater than the total number of first and second detection zones cut by the second type of target; the total number of first and second detection zones cut by the second type of target is greater than or equal to 1.

[0149] The first type of target is a target with an altitude higher than the first altitude, the second type of target is a target with an altitude lower than the second altitude, and the first altitude is greater than or equal to the second altitude.

[0150] In this embodiment of the application, in order to reduce the occurrence of false alarms by the passive infrared detector, the passive infrared detector can adopt a dual Pyro structure (which can be referred to as the first Pyro and the second Pyro, respectively), and the detection areas of the first Pyro and the second Pyro can be divided into multiple detection zones by an optical system (the detection zone obtained by dividing the detection area of ​​the first Pyro can be referred to as the first detection zone, and the detection zone obtained by dividing the detection area of ​​the second Pyro can be referred to as the first detection zone).

[0151] For example, the aforementioned multiple first detection zones and multiple second detection zones can be evenly and alternately distributed from high to low and from far to near within the defense zone of the passive infrared detector.

[0152] For example, taking a scenario where both the first and second detection zones have seven sections, the distribution of the first and second detection zones within the defense zone of the passive infrared detector can be found in [reference needed]. Figure 2A .like Figure 2A As shown, P1H1~PIH7 is the first detection zone, and P2H1~P2H7 is the second detection zone. The first and second detection zones are evenly distributed from high to low and from far to near the ground within the protection zone of the passive infrared detector.

[0153] In this embodiment, through the above-mentioned setting of detection zones, for a target (referred to as a first type target) whose height exceeds a preset height (referred to as a first height), when it enters the defense zone, the number of first detection zones that can be cut (i.e., the number of first detection zones that can detect the target, the same below) and the number of second detection zones are both not less than the number of first detection zones and the number of second detection zones cut by a target (referred to as a second height threshold) whose height is lower than the preset height (referred to as a second height threshold) within the defense zone. Furthermore, the total number of detection zones cut by the first type target (the sum of the number of first detection zones and the number of second detection zones) is greater than that of the second type. Therefore, when a first type target enters the defense zone, the electrical signal output by the first Pyro can be greater than that of the second type. When a target enters the protected area, the electrical signal output by the first Pyro and / or the electrical signal output by the second Pyro when a first type of target enters the protected area can be greater than the electrical signal output by the second Pyro when a second type of target enters the protected area. By setting an appropriate alarm threshold, when a first type of target enters the protected area, the electrical signals output by both the first and second Pyro exceed the alarm threshold, while when a second type of target enters the protected area, the electrical signals output by the first and / or second Pyro do not exceed the alarm threshold. That is, a first type of target can trigger the passive infrared detector to perform alarm processing, while a second type of target will not trigger the passive infrared detector to perform alarm processing. This effectively reduces the occurrence of false alarms while ensuring the detection rate.

[0154] For example, for a target entering the defense zone, the more first detection zones it cuts, the greater the energy of the electrical signal that triggers the first Pyro output; the more second detection zones it cuts, the greater the energy of the electrical signal that triggers the second Pyro output.

[0155] For example, within the defense zone, the total number of first and second detection zones cut by the second type of target is greater than or equal to 1. That is, for the first and second detection zones that are continuously and alternately distributed within the defense zone, the gap between adjacent first and second detection zones is small. The second type of target will not be in the gap between adjacent first and second detection zones, and will neither cut the first nor the second detection zone. Therefore, the passive infrared detector can detect both the first and second type of targets that enter the defense zone.

[0156] For example, a detection record can be generated even if a passive infrared detector detects a target but determines that the alarm triggering conditions are not met.

[0157] In one example, within the defense zone, the number of first detection zones and the number of second detection zones that a first type of target can cut into are both greater than or equal to 2; the number of first detection zones and the number of second detection zones that a second type of target can cut into are both less than 1, that is, a second type of target can cut into 1 first detection zone and / or 1 second detection zone.

[0158] For example, with Figure 2A Taking the detection partition distribution shown as an example, for the first type of target (such as...) Figure 2A (The human body in the middle), which can cut the signals of the two detection partitions P1H1 and P1H2 of Pyro1, and cut the signals of the two detection partitions P2H2 and P2H3 of Pyro2.

[0159] For example, the first height and the second height can be set according to empirical values ​​of the height of the target to be detected and the height of the target to be avoided from triggering false alarms.

[0160] For example, the purpose of deploying passive infrared detectors is to detect human beings entering the protected area. However, to avoid false alarms triggered by pets such as cats and dogs, the aforementioned first and second heights can be set based on the empirical values ​​of human height and the heights of pets such as cats and dogs.

[0161] In some embodiments, the optical system 530 may include an optical element assembly that can divide the first Pyro detection region into a plurality of first detection partitions and the second Pyro detection region into a plurality of second detection partitions based on the principles of reflection and / or refraction.

[0162] For example, an optical element assembly can be provided in a passive infrared detector, and the optical element assembly can be used to divide the detection area of ​​the first Pyro into multiple first detection zones based on the principles of reflection and / or refraction, and the detection zone of the second Pyro can be divided into multiple second detection zones.

[0163] For example, the aforementioned optical element assembly can be disposed in front of the first Pyro and the second Pyro to adjust the detectable area of ​​the first Pyro and the second Pyro within the protection zone (i.e., the aforementioned first detection zone and second detection zone).

[0164] For targets that enter the defense zone and cut through the first detection zone, the infrared radiation they emit can be received by the first Pyro after reflection and / or refraction by the aforementioned combination of optical elements; for targets that enter the defense zone but do not cut through the first detection zone, the infrared radiation they emit cannot be received by the first Pyro after reflection and / or refraction by the aforementioned combination of optical elements.

[0165] Similarly, for targets that enter the defense zone and cut through the second detection zone, the infrared radiation they emit can be received by the second Pyro after reflection and / or refraction by the aforementioned combination of optical elements; for targets that enter the defense zone but do not cut through the second detection zone, the infrared radiation they emit cannot be received by the second Pyro after reflection and / or refraction by the aforementioned combination of optical elements.

[0166] In one example, the above optical element combination may include a multi-layer partitioned Fresnel lens array;

[0167] The multi-layer partitioned Fresnel lens array includes a first region corresponding to the first Pyro and a second region corresponding to the second Pyro;

[0168] The first region of the multi-layer partitioned Fresnel lens array is used to divide the first Pyro detection region into multiple first detection partitions;

[0169] The second region of the multi-layer partitioned Fresnel lens array is used to divide the second Pyro detection region into multiple second detection partitions.

[0170] For example, the detectable area of ​​the first Pyro and the second Pyro within the defense zone can be adjusted by a multi-layered partitioned Fresnel lens array.

[0171] For example, a multi-layer partitioned Fresnel lens array may include a region corresponding to a first Pyro (which may be referred to as the first region) and a region corresponding to a second Pyro (which may be referred to as the second region).

[0172] The first region of the multi-layer partitioned Fresnel lens array is used to divide the first Pyro detection region into multiple first detection regions, and the second region of the multi-layer partitioned Fresnel lens array is used to divide the second Pyro detection region into multiple second detection regions.

[0173] In some embodiments, such as Figure 6As shown, the passive infrared detector may also include an optical system blocking device 540; wherein:

[0174] When the optical system blocking device 540 is in the first state, it does not block the optical system;

[0175] When the optical system blocking device 540 is in the second state, it blocks a portion of the area corresponding to the target Pyro in the optical system, so that there are no target detection zones with a height lower than the third height threshold within the defense zone.

[0176] For example, the target Pyro is the first Pyro, and the target probe partition is the first probe partition; or, the target Pyro is the second Pyro, and the target probe partition is the second probe partition.

[0177] For example, the third height threshold is less than or equal to the first height threshold, and the third height threshold is greater than or equal to the second height threshold.

[0178] For example, considering that passive infrared detectors are deployed at relatively low positions, such as when wall-mounted passive infrared detectors are in a low-mounted state (also known as a low-mounted high state), if the detection zones are distributed as described above, the second type of target may also be cut into multiple first detection zones and multiple second detection zones. As a result, the passive infrared detector may not be able to distinguish between the first type of target and the second type of target, leading to a higher probability of false alarms.

[0179] To address the aforementioned issues, the passive infrared detector may further include an optical system blocking device 540. This optical system blocking device 540 can be used in certain situations, such as when the aforementioned wall-mounted passive infrared detector is in a low-hanging state, to block a portion of the optical system, thereby altering the distribution of the detection zones of the first Pyro and the second Pyro.

[0180] Accordingly, the optical system blocking device 540 in the passive infrared detector may include at least two states (which may be referred to as the first state and the second state, respectively).

[0181] When the optical system blocking device is in the first state, the optical system is not blocked, and the distribution of the detection zones of the first Pyro and the second Pyro can be as described in the above method embodiment.

[0182] When the optical system blocking device is in the second state, it can block a portion of the area corresponding to the target Pyro in the optical system, so that there are no target detection zones with a height lower than the preset height (which can be called the third height) within the passive infrared detector's defense zone.

[0183] For example, when the optical system's blocking device is in its second state, the distribution of the first and second detection zones within the protected area can be seen in [reference needed]. Figure 2B ,like Figure 2B As shown, Pyro2 can retain only the highest probe partition, while Pyro1 retains all probe partitions.

[0184] For example, the target Pyro can be either a first Pyro or a second Pyro.

[0185] For example, when the target Pyro is the first Pyro, the above target detection partition is the first detection partition; when the target Pyro is the second Pyro, the above target detection partition is the second detection partition.

[0186] Since the optical system's blocking device is in the second state, there are no target detection zones with heights lower than the third height within the passive infrared detector's protection zone. Therefore, the second type of target will not be detected by the target Pyro within the protection zone, meaning that the electrical signal output by the target Pyro will not trigger the alarm condition, which can effectively reduce false alarms.

[0187] For the first type of target, after it enters the protection zone, it can still cut through the detection zones of the first Pyro and the second Pyro. By setting an appropriate alarm threshold, the electrical signals output by the first Pyro and the second Pyro can both meet the alarm conditions.

[0188] In one example, with the optical system blocking device in the second state, the optical system blocking device is located between the optical system and the target Pyro.

[0189] For example, since the field of view of the target Pyro after processing by the optical system is diffused, the closer to the target Pyro, the smaller the area covered by its field of view. Therefore, compared with the case where the optical system blocking device is located outside the optical system, the blocking method where the optical system blocking device is located between the optical system and the target Pyro can achieve similar blocking requirements with a smaller area of ​​optical system blocking device.

[0190] Accordingly, in order to save materials for the optical system shielding device, the optical system shielding device is in the second state, and the optical system shielding device can be located between the optical system and the target Pyro.

[0191] For example, one end of the optical system blocking device can be fixedly mounted on one side of the target Pyro, such as the upper or lower side, and the other end can rotate around the fixed end to switch between a first state and a second state.

[0192] When the optical system blocking device is in the second state, the active end of the optical system blocking device (i.e. the end used for blocking) can block the field of view corresponding to the target detection zone with a height lower than the third height according to the blocking requirements.

[0193] For example, when the optical system blocking device is in the second state, the smaller the distance between the movable end of the optical system blocking device and the target Pyro, the smaller the area of ​​the optical system blocking device required for the same blocking requirement. In addition, when the optical system blocking device is in the first state, the optical system blocking device needs to be hidden (e.g., not blocking the field of view of the target Pyro). Reducing the area of ​​the optical system blocking device can reduce the space required to hide the optical system blocking device.

[0194] Accordingly, the movable end of the optical system blocking device can be set as an arc-shaped structure instead of a planar structure. When the optical system blocking device is in the second state, the protruding part faces the optical system to further reduce the area of ​​the optical system blocking device and save the space occupied by the optical system blocking device. Its schematic diagram can be shown as follows. Figure 9 As shown.

[0195] In some embodiments, when the passive infrared detector is installed in a first height range, the optical system blocking device is in a first state; when the passive infrared detector is installed in a second height range, the optical system blocking device is in a second state.

[0196] Among them, the lower limit of the first height range is greater than the first height, the upper limit of the second height range is less than the first height, and the lower limit of the second height range is greater than the second height.

[0197] For example, suppose the first height is H1, the second height is H2, the range of the first height is [H11, H12], and the range of the second height is [H21, H22], then H12 > H1, H21 < H1, and H22 > H2.

[0198] For example, consider a passive infrared detector with its height in the high-mounted state within the first height range and its height in the low-mounted state within the second height range.

[0199] When the passive infrared detector is installed within a first altitude range, the optical system blocking device is in its first state and does not block the optical system. In this case, multiple first detection zones and multiple second detection zones are continuously and alternately distributed from high to low and from far to near within the passive infrared detector's protection zone. For example, its schematic diagram can be as follows: Figure 2A As shown.

[0200] When the passive infrared detector is installed at the second altitude, the optical system blocking device is in its second state, blocking a portion of the area corresponding to the target Pyro within the optical system. In this case, there are no target detection zones with altitudes lower than the third altitude within the protected area. For example, a schematic diagram could be shown below. Figure 2B As shown.

[0201] In one example, when the passive infrared detector is installed at a second altitude range and at a height higher than the fourth altitude, the optical system blocking device is in a second state, and there are at least two target detection zones at a height higher than or equal to the third altitude within the protected area.

[0202] When the passive infrared detector is installed at the second altitude range and the installation height is lower than the fifth altitude, the optical system blocking device is in the second state, and the number of target detection zones within the defense zone is 1.

[0203] The fourth altitude is greater than the fifth altitude.

[0204] For example, considering that the passive infrared detector is in a low-mounted state, that is, when the mounting height is in the second height range, the height distribution of the target detection zone will be different depending on the mounting height of the passive infrared detector.

[0205] For example, the higher the mounting height of the passive infrared detector (in low mounting state), the higher the maximum height that the target detection zone can cover, that is, the higher the height of the highest target detection zone is usually; the lower the mounting height of the passive infrared detector (in low mounting state), the lower the maximum height that the target detection zone can cover, that is, the lower the height of the highest target detection zone is usually.

[0206] Accordingly, in order to prevent second-type targets from cutting into the target detection zone when entering the defense zone, the degree of shielding required for the target Pyro will vary depending on the mounting height of the passive infrared detector.

[0207] For example, in the low-mounted state, the degree of obstruction of the field of view of the target Pyro when the passive infrared detector is installed at a higher height can be no higher than the degree of obstruction of the field of view of the target Pyro when the passive infrared detector is installed at a lower height.

[0208] In the low-mounted state, the position of the optical system blocking device can be adjusted according to the installation height of the passive infrared detector to adjust the degree of obstruction of the target Pyro's field of view by the optical system blocking device, and thus adjust the distribution of target detection zones within the defense zone, such as the number of target detection zones.

[0209] For example, when the passive infrared detector is installed in the second altitude range (i.e., in a low-mounted state) and the installation height is higher than the fourth altitude, the optical system blocking device is in the second state (i.e. blocking the target Pyro), and there are at least two target detection zones with heights higher than or equal to the third altitude within the protected area.

[0210] When the passive infrared detector is installed at the second altitude range and at a height lower than the fifth altitude, the optical system is in the second state at this time, and there is one target detection zone within the defense zone, the height of which is higher than or equal to the third altitude.

[0211] In one example, such as Figure 7 As shown, the passive infrared detector may also include: a threshold circuit 550 and a status recognition button 560;

[0212] When the optical system blocking device 540 is in the first state, the status recognition button 560 is in the released state; when the optical system blocking device 540 is in the second state, the status recognition button 560 is in the connected state.

[0213] When the status recognition button is in the released state and the on state, the threshold circuit sets different alarm thresholds for the first pyroelectric infrared sensor, and / or, when the status recognition button is in the released state and the on state, the threshold circuit sets different alarm thresholds for the second pyroelectric infrared sensor.

[0214] For example, in order to improve the accuracy of the alarm threshold setting of the two Pyro channels when the optical system blocking device 540 is in different states, a status recognition button 560 linked to the optical system blocking device 540 can also be set in the passive infrared detector. The status of the status recognition button 560 can change according to the change of the status of the optical system blocking device 540.

[0215] For example, when the optical system blocking device 540 is in the first state, the status recognition button 560 is in the released state; when the optical system blocking device 540 is in the second state, the status recognition button 560 is in the connected state.

[0216] In addition, the passive infrared detector may also be equipped with a threshold circuit 550 for setting the alarm thresholds of the first Pyro and the second Pyro. The threshold circuit 550 can set the alarm thresholds of the first Pyro and the second Pyro according to the state of the status recognition button 560.

[0217] Considering that the distribution of the first and second detection zones within the protected area can differ significantly depending on the state of the optical system's blocking device (e.g., the first state or the second state), for example, the detection zone distributions when the optical system's blocking device is in the first and second states can be as follows: Figure 2A and 2B As shown, when a first-type target or a second-type target enters the defense zone, the way they cut the detection zone will also differ, resulting in differences in the energy of the electrical signals that trigger the output of the first Pyro and the second Pyro.

[0218] To ensure the detection rate of the first type of target, different alarm thresholds can be set for the first Pyro and / or the second Pyro when the optical system blocking device is in the first state and when the optical system blocking device is in the second state.

[0219] Accordingly, the passive infrared detector may also include a threshold circuit for setting an alarm threshold for the first Pyro and / or the second Pyro.

[0220] For example, the threshold circuit and the optical system's blocking device can be linked through a status recognition button.

[0221] When the status recognition button is in the released state and the on state, that is, when the optical system blocking device is in the first state and the second state, the threshold circuit can set different alarm thresholds for the first Pyro, and / or the threshold circuit can set different alarm thresholds for the second Pyro.

[0222] This application also provides a passive infrared detector, including: a first Pyro, a second Pyro, an optical system, and an optical system blocking device; wherein:

[0223] The first Pyro is used to receive infrared radiation from targets within the detection area and convert the received infrared radiation into electrical signals.

[0224] The second Pyro is used to receive infrared radiation from targets within the detection area and convert the received infrared radiation into electrical signals.

[0225] An optical system is used to divide the detection area of ​​the first Pyro into multiple first detection partitions, and to divide the detection area of ​​the second Pyro into multiple second detection partitions.

[0226] The first pyro is located above the second pyro, and the rotation axis of the optical system blocking device is located below the second pyro. Along the direction perpendicular to the arrangement of the first and second pyro, the movable end of the optical system blocking device is located between the optical system and the second pyro. During the rotation of the optical system blocking device, the height of the highest point of the movable end of the optical system blocking device is less than the height of the highest point of the second optical system partition. The optical system blocking device blocks some of the multiple second detection partitions or does not block multiple second detection partitions by rotating. The second optical system partition in the optical system is used to divide the detection area of ​​the second pyro into multiple second detection partitions.

[0227] In this embodiment of the application, in order to reduce the occurrence of false alarms by passive infrared detectors, the passive infrared detector can adopt a dual Pyro structure (which can be referred to as the first Pyro and the second Pyro, respectively). The detection areas of the first Pyro and the second Pyro are divided into multiple detection zones by an optical system (the detection zone obtained by dividing the detection area of ​​the first Pyro can be referred to as the first detection zone, and the detection zone obtained by dividing the detection area of ​​the second Pyro can be referred to as the first detection zone). By the difference in the number of first detection zones and second detection zones cut by targets of different heights, the detector can distinguish targets of different heights (such as people or pets) and reduce the occurrence of false alarms.

[0228] In addition, to ensure the compatibility of passive infrared detectors with different mounting heights, the passive infrared detector may also include an optical system blocking device. When the passive infrared detector is mounted at different heights, the optical system blocking device can be in different states to change the distribution of the first detection zone and the second detection zone within the protection zone of the passive infrared detector. This allows the passive infrared detector to distinguish targets (such as people or pets) at different heights under different mounting heights, reducing the occurrence of false alarms.

[0229] In this embodiment, since the field of view of the target Pyro after processing by the optical system is diffused, the closer to the target Pyro, the smaller the area covered by its field of view. Therefore, compared with the case where the optical system blocking device is located outside the optical system, the blocking method where the optical system blocking device is located between the optical system and the target Pyro can achieve similar blocking requirements with a smaller area of ​​optical system blocking device.

[0230] Accordingly, in order to save materials for the optical system shielding device, the optical system shielding device can be deployed between the second Pyro and the optical system.

[0231] For example, one end of the optical system blocking device can be fixedly mounted below the second Pyro, and the other end can rotate around the fixed end. The fixed end can be referred to as the pivot, and the other end can be referred to as the movable end.

[0232] Along the direction perpendicular to the arrangement of the first Pyro and the second Pyro, the movable end of the optical system blocking device is located between the optical system and the second Pyro. During the rotation of the optical system blocking device, the height of the highest point of the movable end of the optical system blocking device is less than the height of the highest point of the optical system partition (referred to as the second optical system partition in this paper) used to divide the detection area of ​​the second Pyro into multiple detection partitions.

[0233] Since the field of view of the second Pyro is divergent, the higher the height of the highest point of the active end of the optical system blocking device needs to be, the closer it is to the second Pyro, and the higher the height of the highest point of the active end of the optical system blocking device can be, the closer it is to the optical system.

[0234] For example, the optical system blocking device can block some of the above-mentioned multiple second detection zones or not block the above-mentioned multiple second detection zones by rotating, so as to meet the application requirements of different hanging height states respectively.

[0235] For example, the schematic diagrams of the detection zone distribution when the optical system blocking device blocks part of the aforementioned plurality of second detection zones, and when the optical system blocking device does not block the aforementioned plurality of second detection zones, can be respectively as shown in the figure. Figure 2B and Figure 2A As shown.

[0236] To enable those skilled in the art to better understand the technical solutions provided in the embodiments of this application, the technical solutions provided in the embodiments of this application are described below in conjunction with specific application scenarios.

[0237] This embodiment provides an optical pet-proof wall-mounted passive infrared detector (hereinafter referred to as PIR detector) that is compatible with both high-mounted and low-mounted states. The PIR detector achieves 90° wall-mounted detection through a dual Pyro dual Lens (Fresnel lens array) scheme, and can achieve the same size detection zone without moving the Pyro circuit board when switching between high-mounted and low-mounted states.

[0238] The design principle of the PIR detector provided in this embodiment will be explained below.

[0239] 1. Slice-based continuous detection defense zone design

[0240] This embodiment adopts a sliced ​​continuous detection zone design, which divides the area to be detected by the PIR detector into spatial slices, so that the dual Pyro signals are evenly distributed in the zone.

[0241] This slice-based continuous detection zone design (such as...) Figure 2A As shown) compared to traditional PIR detection zones (such as Figure 2C The design (as shown) reduces the interval between dark areas, increasing the differentiation between signals triggered by humans and pets.

[0242] like Figure 2A As shown, in this embodiment, when the PIR detector is in the high-mounted state, the detection zones are P1H1 to P1H7, which are the detection zones (or detection sectors) of the first Pyro (which can be called Pyro1), and P2H1 to P2H7, which are the detection zones of the second Pyro (which can be called Pyro2). That is, Pyro1 and Pyro2 each have 7 layers of detection zones within the detection zone. The two Pyro detection zones are interspersed to form the continuous detection zones of the PIR detector.

[0243] It should be noted that the seven-layer detection zone mentioned here is just an example and not a limitation on the scope of protection of this application. In actual applications, the number of layers in the uniform slice may vary depending on the size of the protected zone.

[0244] like Figure 2A As shown, when a human moves within the protected area, the signals of the two detection zones P1H1 and P1H2 of Pyro1 and the two detection zones P2H2 and P2H3 of Pyro2 can be cut off; when a pet moves within the protected area, the signals of the one detection zone P1H3 of Pyro1 and P2H3 of Pyro2 can be cut off.

[0245] The number of layers that cut the Pyro signal corresponds to different signal strengths generated by the PIR detector (i.e., the signal strength of the electrical signal output by the Pyro). The more layers the detection partition is cut into, the greater the energy of the electrical signal output by the Pyro.

[0246] Based on the sliced ​​continuous zone design in this embodiment, when the PIR detector is mounted high, human movement can cut the signal of at least two detection zones in each Pyro path, while pets can only cut the signal of one detection zone in each Pyro path, thus increasing the signal differentiation between humans and pets.

[0247] It should be noted that the required detection zone range of the PIR detector in this embodiment must be consistent under different installation heights, and the detection distance must be greater than 15m. In this long-distance detection (detection distance ≥ 15m) application scenario, the PIR detector will only issue an alarm when both Pyro signals trigger the alarm signal threshold. This dual-Pyro shared zone monitoring can more effectively reduce the false alarm rate and reduce detection blind spots.

[0248] 2. Multi-layer partitioned Fresnel lens array design

[0249] like Figure 8 The diagram shown is a schematic of a multi-layer partitioned Fresnel lens array (hereinafter referred to as the lens array) in the PIR detector provided in this embodiment. The lens array is divided into two regions (i.e., the first region and the second region mentioned above), and each region corresponds to one Pyro field of view.

[0250] In this example, seven Fresnel lenses are densely distributed in both the upper and lower regions. L1T1–L1T7 correspond to the Pyro1 field of view, and L2T1–L2T7 correspond to the Pyro2 field of view. Through these seven lenses, the PIR detection zone is sliced ​​into 14 layers, corresponding to… Figure 2A The diagram shows P1H1~P1H7 and P2H1~P2H7.

[0251] 3. High and low mounting design compatible with pet protection

[0252] In this embodiment, by combining the continuous slice protection zone design with the lensmask (Fresnel lens shield, i.e., the optical system shielding device mentioned above) shielding design, a compatible installation design with pet detection function is achieved for the product in both high and low mounting states.

[0253] For example, in the high-mounted installation state, the Fresnel lens arrays of the upper and lower sections are used for full-field-of-view detection, enabling the detection area in the high-mounted state to be divided into 14 detection zones (e.g., Figure 2A (P2H1~P2H7, P1H1~P1H7 in the text).

[0254] In the high-mounted state, both Pyro channels can detect people and pets. However, the signals from the two Pyro channels triggered by a human are stronger than those triggered by a pet. By setting an appropriate alarm threshold, and when both Pyro signals alarm (human movement can trigger the alarm, but pet movement cannot), the PIR detector will process the alarm, thus achieving pet protection under high-mounted installation.

[0255] In the low-mounted, high-installation state (e.g.) Figure 2BAs shown), by adjusting the lensmask to block part of the lens L2T2 to L2T7, only the first layer of lens L2T1 is retained, so that Pyro2 (taking the above target Pyro as Pyro2 as an example) under the low-mounted installation state has only one detection zone P2L1 in the defense zone.

[0256] For example, the detection zone P2L1 can only detect moving targets that are higher than the installation height of the PIR (i.e., the installation height of the PIR in the low-mounted state is the third height threshold mentioned above). Thus, the trigger signals of the two Pyro channels for people and pets are different. Through the readout circuit and software judgment design, when both Pyro signals alarm, it is determined that the signal is triggered by human movement, which can effectively block the pet signal.

[0257] As can be seen, the high and low hanging pet protection design proposed in this embodiment can be adapted to pet protection needs under different installation conditions by simply operating the lensmask. The user operation steps are simple when using the product, and there is no need to move the Pyro circuit board, which increases the reliability of the circuit.

[0258] like Figure 9 As shown, in the high-mounted installation state, the lensmask does not obstruct the Pyro field of view. The front lens assembly divides the detection area of ​​Pyro1 into P1H1~P1H7 and the detection area of ​​Pyro2 into P2H1~P2H7, for a total of 14 detection zones. This creates a continuous, blind-spot-free segmentation of the detection zone for upright pedestrians within the 90° detection field of view of the wall mount, thus widening the signal difference between people and pets in the high-mounted state and effectively preventing pets from entering the area.

[0259] With the device mounted low, the lensmask handle is moved to block the lower lenses L2T2 to L2T7, leaving only the L2T1 optical window open. The radiation detection system, composed of Pyro2 and L2T1, generates the P2L1 detection zone. The P2L1 sector can detect humans but does not trigger a signal for pets near the ground. Pyro1 and the front lens assembly maintain their 7-layer zone design, detecting movement signals from both humans and pets. However, the PIR detector only issues an alarm if both Pyro signals exceed the alarm threshold. This combined use of two Pyro signals effectively reduces the false alarm rate and optimizes pet-proof performance.

[0260] 4. Linkage design of Lensmask and threshold circuit

[0261] Because the intensity of the alarm signal generated by a human body can vary depending on the installation state of the same PIR product (such as high-mounted or low-mounted), the back-end processing circuit needs to adjust the alarm threshold accordingly for different installation states.

[0262] In this embodiment, the lensmask and the backend threshold circuit are designed to work together, and the threshold circuit includes a status recognition button (e.g., Figure 9 The button in the middle is used to identify whether the PIR detector is in a high-mounted or low-mounted state.

[0263] like Figure 9 As shown in (a), when the PIR detector is in the high-mounted state, moving the lensmask handle so that the lensmask lever is below the button, the button is in the released state, and the threshold circuit recognizes the switch signal value as "0"; while as Figure 9 As shown in (b), when the PIR detector is in the low-hanging state, the lensmask handle is moved downwards, causing the lensmask lever to press the button. The button is in the ON state, and the threshold circuit recognizes the switch signal value as "1" (e.g., Figure 10 (As shown). The threshold circuit can adjust the alarm threshold by recognizing the state of the button, thereby completing the detection of human movement and pet prevention under different installation conditions.

[0264] Through the linkage design of Lensmask and threshold circuit, when the PIR product switches from high-mounted to low-mounted state, the user only needs to operate the lensmask handle, eliminating the need for multiple steps. This simplifies the user operation process and greatly improves operability and product experience.

[0265] It should be noted that, in this document, relational terms such as "objective" and "target" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0266] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A passive infrared detector, characterized in that, include: A first pyroelectric infrared sensor, a second pyroelectric infrared sensor, an optical system, and an optical system shielding device; wherein: The first pyroelectric infrared sensor is used to receive infrared radiation from targets within the detection area and convert the received infrared radiation into electrical signals. The second pyroelectric infrared sensor is used to receive infrared radiation from targets within the detection area and convert the received infrared radiation into electrical signals. An optical system is used to divide the detection area of ​​a first pyroelectric infrared sensor into multiple first detection zones, and to divide the detection area of ​​a second pyroelectric infrared sensor into multiple second detection zones. An optical system blocking device is used to not block the optical system in a first state, and to block a portion of the region of the optical system corresponding to the target pyroelectric infrared sensor in a second state. Wherein, when the optical system shielding device is in the first state, the plurality of first detection zones and the plurality of second detection zones are continuously and alternately distributed from high to low and from far to near within the protection zone of the passive infrared detector; within the protection zone, the number of first detection zones cut by a first type of target is greater than or equal to the number of first detection zones cut by a second type of target, the number of second detection zones cut by a first type of target is greater than or equal to the number of second detection zones cut by a second type of target, and the total number of first and second detection zones cut by a first type of target is greater than the total number of first and second detection zones cut by a second type of target; for a target entering the protection zone, the more first detection zones it cuts, the greater the energy of the electrical signal triggered by the first Pyro output; the more second detection zones it cuts, the greater the energy of the electrical signal triggered by the second Pyro output. When the optical system shielding device is in the second state, there are no target detection zones with a height lower than the third height within the defense zone; The target pyroelectric infrared sensor is the first pyroelectric infrared sensor, and the target detection zone is the first detection zone; or, the target pyroelectric infrared sensor is the second pyroelectric infrared sensor, and the target detection zone is the second detection zone; The first type of target is a target with a height higher than the first height, the second type of target is a target with a height lower than the second height, and the first height is greater than or equal to the second height; The third height is less than or equal to the first height, and the third height is greater than or equal to the second height.

2. The passive infrared detector according to claim 1, characterized in that, When the optical system shielding device is in the first state, within the protected area, the number of the first detection partitions cut by the first type of target is greater than or equal to 2, and the number of the second detection partitions cut by the first type of target is greater than or equal to 2. The number of the first detection partitions of the second type of target is less than or equal to 1, and the number of the second detection partitions of the first type of target is less than or equal to 1, and the total number of the first detection partitions and the second detection partitions of the second type of target is greater than or equal to 1.

3. The passive infrared detector according to claim 1, characterized in that, When the optical system blocking device is in the second state, the number of target detection zones within the defense zone is 1.

4. The passive infrared detector according to claim 1, characterized in that, When the passive infrared detector is installed at a first height range, the optical system shielding device is in a first state; when the passive infrared detector is installed at a second height range, the optical system shielding device is in a second state. Wherein, the lower limit of the first height range is greater than the first height, the upper limit of the second height range is less than the first height, and the lower limit of the second height range is greater than the second height.

5. The passive infrared detector according to claim 1, characterized in that, The optical system includes an optical element assembly that, based on the principles of reflection and / or refraction, divides the detection area of ​​the first pyroelectric infrared sensor into multiple first detection zones, and divides the detection area of ​​the second pyroelectric infrared sensor into multiple second detection zones.

6. The passive infrared detector according to claim 5, characterized in that, The optical element assembly includes a multi-layer partitioned Fresnel lens array; The multi-layer partitioned Fresnel lens array includes a first region corresponding to the first pyroelectric infrared sensor and a second region corresponding to the second pyroelectric infrared sensor. The first region of the multi-layer partitioned Fresnel lens array is used to divide the detection area of ​​the first pyroelectric infrared sensor into multiple first detection partitions. The second region of the multi-layer partitioned Fresnel lens array is used to divide the detection area of ​​the second pyroelectric infrared sensor into multiple second detection partitions.

7. The passive infrared detector according to claim 1, characterized in that, Also includes: Status recognition button; When the optical system blocking device is in the first state, the state recognition button is in the released state; When the optical system blocking device is in the second state, the state recognition button is in the ON state.

8. The passive infrared detector according to claim 7, characterized in that, Also includes: Threshold circuit; When the status recognition button is in the released state and the on state, the threshold circuit sets different alarm thresholds for the first pyroelectric infrared sensor, and / or, when the status recognition button is in the released state and the on state, the threshold circuit sets different alarm thresholds for the second pyroelectric infrared sensor.

9. A passive infrared detector, characterized in that, include: A first pyroelectric infrared sensor, a second pyroelectric infrared sensor, and an optical system; wherein: The first pyroelectric infrared sensor is used to receive infrared radiation from targets within the detection area and convert the received infrared radiation into electrical signals. The second pyroelectric infrared sensor is used to receive infrared radiation from targets within the detection area and convert the received infrared radiation into electrical signals. An optical system is used to divide the detection area of ​​a first pyroelectric infrared sensor into multiple first detection zones, and to divide the detection area of ​​a second pyroelectric infrared sensor into multiple second detection zones. The plurality of first detection zones and the plurality of second detection zones are continuously and alternately distributed from high to low and from far to near within the protection zone of the passive infrared detector; Within the defense zone, the number of first detection zones cut by the first type of target is greater than or equal to the number of first detection zones cut by the second type of target, the number of second detection zones cut by the first type of target is greater than or equal to the number of second detection zones cut by the second type of target, and the total number of first and second detection zones cut by the first type of target is greater than the total number of first and second detection zones cut by the second type of target; the total number of first and second detection zones cut by the second type of target is greater than or equal to 1; for a target entering the defense zone, the more first detection zones it cuts, the greater the energy of the electrical signal triggered by the first Pyro output; the more second detection zones it cuts, the greater the energy of the electrical signal triggered by the second Pyro output. The first type of target is a target with a height higher than the first height, and the second type of target is a target with a height lower than the second height, wherein the first height is greater than or equal to the second height.

10. The passive infrared detector according to claim 9, characterized in that, The optical system includes an optical element assembly, which includes a multi-layer partitioned Fresnel lens array. The multi-layer partitioned Fresnel lens array includes a first region corresponding to the first pyroelectric infrared sensor and a second region corresponding to the second pyroelectric infrared sensor. The first region of the multi-layer partitioned Fresnel lens array is used to divide the detection area of ​​the first pyroelectric infrared sensor into multiple first detection partitions. The second region of the multi-layer partitioned Fresnel lens array is used to divide the detection area of ​​the second pyroelectric infrared sensor into multiple second detection partitions.

11. The passive infrared detector according to claim 9, characterized in that, Also includes: Optical system shielding devices; among which: When the optical system blocking device is in the first state, the optical system is not blocked; When the optical system blocking device is in the second state, it blocks a portion of the area of ​​the corresponding target pyroelectric infrared sensor in the optical system, so that there are no target detection zones with a height lower than the third height within the defense zone. The target pyroelectric infrared sensor is the first pyroelectric infrared sensor, and the target detection zone is the first detection zone; or, the target pyroelectric infrared sensor is the second pyroelectric infrared sensor, and the target detection zone is the second detection zone; The third height is less than or equal to the first height, and the third height is greater than or equal to the second height.

12. The passive infrared detector according to claim 11, characterized in that, When the passive infrared detector is installed at a first height range, the optical system shielding device is in a first state; when the passive infrared detector is installed at a second height range, the optical system shielding device is in a second state. Wherein, the lower limit of the first height range is greater than the first height, the upper limit of the second height range is less than the first height, and the lower limit of the second height range is greater than the second height.

13. The passive infrared detector according to claim 12, characterized in that, When the passive infrared detector is installed in the second height range and the installation height is higher than the fourth height, the optical system blocking device is in the second state, and there are at least two target detection zones with heights higher than or equal to the third height within the defense zone; When the passive infrared detector is installed in the second height range and the installation height is lower than the fifth height, the optical system blocking device is in the second state, and the number of target detection zones within the defense zone is 1. The fourth height is greater than the fifth height.

14. The passive infrared detector according to claim 11, characterized in that, Also includes: Status recognition button and threshold circuit; When the optical system blocking device is in the first state, the state recognition button is in the released state; When the optical system blocking device is in the second state, the state recognition button is in the ON state; When the status recognition button is in the released state and the on state, the threshold circuit sets different alarm thresholds for the first pyroelectric infrared sensor, and / or, when the status recognition button is in the released state and the on state, the threshold circuit sets different alarm thresholds for the second pyroelectric infrared sensor.

15. A passive infrared detector, characterized in that, include: A first pyroelectric infrared sensor, a second pyroelectric infrared sensor, an optical system, and an optical system shielding device; wherein: The first pyroelectric infrared sensor is used to receive infrared radiation from targets within the detection area and convert the received infrared radiation into electrical signals. The second pyroelectric infrared sensor is used to receive infrared radiation from targets within the detection area and convert the received infrared radiation into electrical signals. An optical system is used to divide the detection area of ​​a first pyroelectric infrared sensor into multiple first detection zones, and to divide the detection area of ​​a second pyroelectric infrared sensor into multiple second detection zones. The first pyroelectric infrared sensor is located above the second pyroelectric infrared sensor, and the rotation axis of the optical system blocking device is located below the second pyroelectric infrared sensor. Along a direction perpendicular to the arrangement of the first and second pyroelectric infrared sensors, the movable end of the optical system blocking device is located between the optical system and the second pyroelectric infrared sensor. During the rotation of the optical system blocking device, the highest point of the movable end of the optical system blocking device is less than the highest point of the second optical system partition. The optical system blocking device can either block part of the plurality of second detection partitions or not block the plurality of second detection partitions by rotating. The second optical system partition in the optical system is used to divide the detection area of ​​the second pyroelectric infrared sensor into multiple second detection partitions.

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