JP5274950B2 - Passive infrared sensor - Google Patents

Description

  The present invention relates to a passive infrared sensor capable of detecting infrared radiation emitted by a human body in a warning area with a detector having an optical system and an infrared detection element, and in particular, a passive infrared sensor in which a plurality of detectors are arranged in a housing. It relates to sensors.

Conventionally, a passive infrared sensor (hereinafter referred to as an infrared sensor) has a detector consisting of a pyroelectric element (infrared detector) and a mirror housing (optical system) in a casing made up of a base, a cover, etc. Infrared rays (heat rays) radiated from the inside are collected with a mirror housing and detected by a pyroelectric element, and this detection signal is processed by a signal processing means to determine whether or not the moving object related to infrared rays is a human body. In this case, a predetermined detection signal is output. In addition, this kind of infrared sensor is disclosed by patent document 1, for example.
Japanese Patent Application Laid-Open No. 11-203666

  However, in such an infrared sensor, the detection zone in the vicinity of the sensor having a short warning distance and the detection zone in the distance of the sensor having a long warning distance are detected by the same pyroelectric element. If the detection zone is a detection zone far away from the sensor where there is a risk of false alarms by reaching the outside of the warning area, configure the detection zone. It is necessary to attach a blindfold to the mirror or lens that prevents the collection and transmission of infrared rays or to adjust the direction of the detector itself so that the detection zone does not reach the outside of the warning area.

  Therefore, when attaching blindfolds, it is difficult to know which part of multiple mirrors or lenses can be covered by the target detection zone, and the attachment surface is not flat and can be attached easily. Difficult to set the detection zone easily. In addition, when adjusting the orientation of the detector itself, the uniformity of the detection performance of each detection zone will be lost, and it is difficult to suppress malfunction due to disturbance of small animals etc. while improving the detection performance for intruders. Is the actual situation.

  The present invention has been made in view of such circumstances, and its purpose is to independently process detection signals of a plurality of detectors, each of which can be adjusted in angle and arranged in the vicinity of the housing and have different warning distances. By making it possible to individually set whether or not each detector can be used, it is possible to easily perform detection zone setting work and to suppress malfunction due to disturbance of small animals etc. while improving detection performance for intruders. It is to provide a possible passive infrared sensor.

In order to achieve such an object, the invention described in claim 1 of the present invention is arranged in a casing made up of a base and a cover, etc., and detects infrared rays in a warning area made up of a plurality of fan-shaped detection zones in a plan view. A detector having an optical system for condensing and an infrared detecting element for detecting infrared light collected by the optical system, a signal processing means for processing a detection signal detected by the detector, and connected to the signal processing means comprising setting means, was, the detector consists of a plurality of different detectors of each individually adjustable angle so closely spaced warning distance has the optical system and the infrared detection element, said setting means Can set the sensitivity and the number of detections of the plurality of detectors, the availability of the detectors and the number of detections of the plurality of detectors as a whole, and the signal processing means can set the availability of all the detectors. , wherein the plurality of detectors Each signal detected alone treated to said output enable der benzalkonium a human body detection signal upon detecting a human body in one of the detector.

According to the first aspect of the present invention, a plurality of angle-adjustable detectors each having an optical system and an infrared detection element are arranged in the vicinity of the housing, and detection signals from the plurality of detectors are received. The signal processing means is used alone, and the availability of each detector , sensitivity, the number of detections, and the number of detections for all detectors can be set by the setting means. It is possible to set the detector to be used by operating the setting means while narrowing the area, making it easy to set the detection zone, and improving the detection performance against intruders with multiple detectors according to the warning distance However, it is possible to suppress malfunctions caused by disturbances of small animals and the like.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
1 to 7 show an embodiment of a passive infrared sensor according to the present invention, FIG. 1 is a perspective view thereof, FIG. 2 is a conceptual diagram showing an internal configuration, FIG. 3 is a block diagram of a control system, and FIG. 5 and 5 are a flowchart showing an example of the operation, and FIGS. 6 and 7 are a plan view and a side view of the alert area.

  As shown in FIG. 1, a passive infrared sensor 1 (referred to as infrared sensor 1) includes a disc-shaped base 2a that is attached to the ceiling or wall surface of a warning area, and a hemisphere that is detachably attached to cover the base 2a. And a housing 2 comprising a ring-shaped locking member 2c for detachably locking the base 2a and the cover 2b to each other.

  As shown in FIG. 2, the infrared sensor 1 includes three detectors comprising a proximity detector 3, an intermediate detector 4, and a remote detector 5 on the disc-shaped base 2a. 3 to 5 are arranged so as to be close to each other and located at the vertices of a substantially triangle. The detector 3 includes a mirror 3a as an optical system, a pyroelectric element 3b as an infrared detection element, and an amplification / filter unit 3c described later. The detectors 4 and 5 are mirrors as an optical system. It has housings 4a and 5a, pyroelectric elements 4b and 5b as infrared detection elements, and amplification / filter sections 4c and 5c described later.

  At this time, the detector 4 and the detector 5 are provided side by side in the left-right direction near one end in the diameter direction of the base 2a, and the pyroelectric elements 4b, 5b of the detectors 4, 5 It is mounted on the element substrate 7 on which the parts 4c and 5c are formed. The mirror housings 4a and 5a of the detectors 4 and 5 have a pair of side walls 8a connected to both ends of the element substrate 7, a bottom wall 8b integrally formed at the rear end portion of the side walls 8a, and the like. A plurality of mirrors 8c are formed on the inner surface. Further, the mirror housings 4a and 5a are rotatably attached to a pair of support plates 9 whose side walls 8a are fixed to the base 2a, so that the directions of the mirrors 8c of the detectors 4 and 5 are in a predetermined direction. The infrared rays (heat rays) reflected (condensed) by the mirror 8c are made incident on the pyroelectric elements 4b and 5b.

  The detector 3 is arranged near the other end side in the diameter direction of the base 2a, the mirror 3a composed of a plurality of mirrors is arranged at a predetermined angle, and an element substrate in front of the mirror 3a by a predetermined distance. 6 is formed with the amplification / filter unit 3c and the pyroelectric element 3b.

  Although not shown, a signal processing unit 11 (to be described later) that processes signals detected by the pyroelectric elements 3b, 4b, and 5b mounted on the element substrates 6 and 7 is formed at a predetermined position of the base 2a. A signal processing board is arranged, and a detection signal or the like is transmitted from a signal processing unit 11 of the signal processing board to a controller (not shown) wirelessly or by wire. Further, as the pyroelectric elements 3b, 4b, and 5b, for example, two pyroelectric elements are differentially connected in series with opposite polarities, and an output signal of a positive (+) polarity pyroelectric element and a minus (-) A two-element one-output differential output type that can obtain a combined output with the output signal of the polar pyroelectric element is used, but a multi-element multi-output type can also be used.

  FIG. 3 shows a block diagram of a control system of the infrared sensor 1. This will be described below. The three detectors 3 to 5 are respectively connected to the signal processing unit 11 (signal processing means) on the signal processing substrate via the amplification / filter units 3c to 5c formed on the element substrates 6 and 7, respectively. Yes. The amplification / filter units 3c to 5c amplify the detection signals detected by the pyroelectric elements 3b, 4b, and 5b, and filter only the detection signals related to the movement of the heat source by filtering the detection signals. The amplification factor and the frequency characteristic of the filter are set in advance according to the detectors 3 to 5, for example.

  The signal processing unit 11 is formed of, for example, a microcomputer and includes a determination unit 11a, a storage unit 11b, and the like, and a setting unit 12 (setting unit) is connected to the input side thereof. The setting unit 12 includes setting switches 12a to 12c for setting availability of the detectors 3 to 5, a setting switch 12d for setting the number of detection times of the detectors 3 to 5, and detection of the detectors 3 to 5. A setting switch 12e for sensitivity setting, a setting switch 12f for setting frequency characteristics of each of the amplification / filter units 10a to 10c, and a reference value (threshold value) setting for determining whether or not a human body is compared with the detection signal. For example, a setting switch 12g.

  In addition, on the output side of the signal processing unit 11, for example, a code indicating the setting state by the transmission unit 13 a for transmitting the human body detection signal determined by the determination unit 11 a to the controller, the setting unit 12, or the human body detection signal An output unit 13 composed of a display unit 13b or the like capable of displaying output (reporting) is connected. Note that the configuration of the setting unit 12 and the output unit 13 is not limited to the illustrated example, and an appropriate configuration can be used.

  Next, an example of operation | movement of the signal processing part 11 comprised in this way is demonstrated based on the flowchart of FIG.4 and FIG.5. 4 and 5 are automatically executed according to the program stored in the storage unit 11b of the signal processing unit 11. First, as shown in FIG. 4, for example, the infrared sensor 1 is attached to the ceiling or the like of a warning place, and various settings such as the warning area (detection zone) are performed for setting the availability of the detectors 3 to 5. When the infrared sensor 1 is turned on, the program is started (S100), and it is determined whether or not the setting switches 12a to 12c for setting the availability of the detectors 3 to 5 of the setting unit 12 are on (S101). Is done. This determination S101 is repeated until “YES”.

  If “YES” in the determination S101, the detectors 3 to 5 corresponding to the setting switches 12a to 12c that are turned on are set to be usable and stored in the storage unit 11b of the signal processing unit 11 (S102). . Next, it is determined whether or not all three detectors 3 to 5 have been set to be usable (S103). If the determination in S103 is "NO", the process returns to step S101, and the steps after step S101 are repeated. On the other hand, if “YES” in the determination S103, that is, if all the availability of the three detectors 3 to 5 are set, the series of programs ends (S104). That is, according to this flowchart, the availability of the three detectors 3 to 5 is individually set by turning on the setting switches 12a to 12c of the setting unit 12 corresponding to the detectors 3 to 5. .

  Thus, in the state where the availability of each detector 3-5 is set, the signal processing unit 11 outputs the human body detection signal S as shown in FIG. FIG. 5 mainly describes the detector 3, but the same applies to the detectors 4 and 5. As shown in FIG. 5, when the infrared sensor 1 is installed at a predetermined position and the program is started (S200), it is determined whether or not a detection signal is input from the detector 3 (or the detectors 4 and 5). (S201).

  If “YES” in this determination S201, that is, if the moving object in the warning area crosses one of the plurality of detection zones of the detector 3 and the level of the detection signal is equal to or higher than the threshold, signal processing is performed. A counter (not shown) provided in the unit 11 is counted up (S202), and it is determined whether the count number is the number of detections n1 (or n2, n3) (S203). The number of detections n1 used in this determination S203 is a number set in advance for each of the detectors 3 to 5, and when the count number in step S202 is the number of detections n1, “YES” is determined in determination S203, and the human body The detection signal S is output (S207), and the series of programs ends (S209).

  On the other hand, if “NO” in the determination S201, that is, if no detection signal is input, it is determined whether a timer (not shown) provided in the signal processing unit 11 is operating (S204), for example. If “YES”, it is determined whether it is within the timer time (S205). If “NO” in this determination S205, the counter is reset and the timer is reset (S206), and the process returns to the determination S201 to wait for the input of the detection signal. Also, if “NO” in the determination S204 and “YES” in the determination S205, the process returns to the determination S201. If “NO” in the determination S203, that is, if the first detection signal is input and the count number has not reached the detection number n1, the timer is started (S208), and the process returns to the determination S201. That is, in the alert state in which the infrared sensor 1 is installed, the human body detection signal S is output when the detection signals n1 to n3 stored in advance corresponding to the alert distance are detected by the detectors 3 to 5. 13 is output to the controller.

  FIG. 6 shows an example of a warning area by the infrared sensor 1. As shown in FIGS. 6 (a) and 6 (b), the detector 3 for the vicinity of the warning distance has the detection zones A1 to A3 in the horizontal plane and the detection zone a in the vertical plane, and the warning distance is for intermediate use. The detector 4 has detection zones B1 to B7 on the horizontal plane and a detection zone b on the vertical plane. Furthermore, the detector 5 for a distant warning distance has detection zones C1 to C7 on the horizontal plane and a detection zone c on the vertical plane. A three-dimensional alert area is formed in the infrared sensor 1 by each of these detection zones.

  Note that the warning area of the infrared sensor 1 of the present invention is not limited to the three-dimensional warning type shown in FIG. 6, but can be applied to, for example, a surface warning type warning area shown in FIG. As shown in FIG. 7 (b), the surface warning type warning area has detection zones d1 to d6 in the vertical plane, and these detection zones d1 to d6 are shown in FIG. 7 (a). As described above, the detection zones D1 to D6 on the horizontal plane are in a state of about one. In the case of this surface alert type alert area, it is used when the width of the alert area is narrow on the horizontal plane.

  Thus, according to the infrared sensor 1 of the said embodiment, the some detectors 3-5 which have the mirror 3a, the mirror housings 4a, 5a, the pyroelectric elements 3b, 4b, 5b, etc. are arrange | positioned closely in the housing 2. FIG. Since the detection signals of the plurality of detectors 3 to 5 are individually processed and the availability of the detectors 3 to 5 having different warning distances is set by the setting unit 12, the setting switch of the setting unit 12 Detectors 3 to 5 to be used can be individually set by the operations of 12a to 12c. In particular, since the availability of the three detectors 3 to 5 can be set by turning on the setting switches 12a to 12c, the setting switches 12a to 12c corresponding to the detectors 3 to 5 that are not used are invalidated by turning off the operation. Therefore, it is not necessary to mask the detectors 3 to 5 that are not used as in the prior art, and the efficiency of setting work when the infrared sensor 1 is installed can be improved.

  In addition, the warning area is covered by setting the three detectors 3 to 5 in a predetermined direction in advance, and the detection zones of the detectors 3 to 5 can be individually set. Orientation adjustment work is not required, and it is possible to prevent the uniformity of detection performance from being lost, and it is possible to prevent malfunction caused by disturbance of a small animal or the like while improving detection performance for intruders. In particular, since the signal processing unit 11 outputs the human body detection signal S based on the detection signals of the usable detectors 3 to 5 set by the setting unit 12, the detectors 3 to 5 set to be usable are used. The human body detection signal S can be output based on the detection signal, and the intruder detection performance can be further enhanced.

  In addition, as a warning area of the infrared sensor 1, it is applied to a three-dimensional warning type warning area composed of detection zones A1 to A3, B1 to B7, C1 to C7 in the horizontal plane and detection zones a to c in the vertical plane. If each detector 3-5 is arrange | positioned corresponding to the fan-shaped several detection zone by side view, the infrared rays radiated | emitted from an intruder (human body) can be detected reliably irrespective of a warning distance. In addition, d1 to d6 are provided on the vertical plane, and these are applied to a surface warning type warning area in which about one is arranged on the horizontal plane. If the detectors 3 to 5 are arranged, the infrared rays emitted from the intruder can be reliably detected, and the detection performance of the infrared sensor 1 can be further enhanced.

  Further, the warning distances of the three detectors 3 to 5 are set to be near, middle, and far, and are arranged in a substantially triangular shape on the disc-shaped base 2a of the housing 2, and the three detectors 3 to 3 are arranged. 5, at least two detectors 4, 5 have a single mirror housing 4 a, 5 a, and are arranged so as to be individually adjustable in angle. Can be reliably set at a desired position, a more accurate warning area can be obtained, and the arrangement of the three detectors 3 to 5 in the housing 2 can be efficiently performed. Thus, a high-performance infrared sensor 1 can be obtained.

  In addition, since the mirror 3a is used for the detector 3 and the mirror housings 4a and 5a are used for the detectors 4 and 5, an optimal optical system can be used for each of the detectors 3 to 5 having different warning distances. While the detection performance in each detector 3-5 can be improved further, the cost increase of infrared sensor 1 itself can be suppressed. Moreover, since each detection signal of the three detectors 3-5 can be processed independently by operation of the setting switches 12a-12c of the setting unit 12, for example, when it is desired to be wary of a range having a relatively short alert distance. The detector 5 is disabled (cannot be used), or the detector 3 is disabled when there is a heat source that causes a false alarm such as a fax in the vicinity of the infrared sensor 1. The three detectors 3 to 5 can be appropriately selected and used, and it is possible to accurately and easily cope with various types of warning areas.

  Furthermore, since the warning area is covered in a separated state by the detectors 3 to 5 provided in the infrared sensor 1, when adjusting the direction of the detectors 3 to 5 for setting the warning distance, detection in the vicinity of the sensor is performed. In addition to eliminating the need to consider the effects on the zone, the detection zones each of the detectors 3 to 5 are easier to understand than in the case of a conventional integrated optical system detector. When there is a heat source that causes false alarms such as masking the detection zone of the part, the work can be easily performed. From these, the work efficiency of the installation work and maintenance work of the infrared sensor 1 can be improved. Improvements can be made.

  Here, like the infrared sensor 1 according to the present invention, the feature of the infrared sensor 1 of the perspective separation type in which the detector is separated into a plurality corresponding to the distance of the warning distance is as follows. This will be described with reference to FIGS. 8 and 9 and the like while comparing with one integrated infrared sensor. 8 and 9 show the state of the detection zone when the infrared sensor having the detection zone as shown in FIG. 7 is adjusted by the warning distance adjustment method of the method according to the present invention and the warning distance adjustment method of the conventional method. Show. As shown in FIG. 7, in the case of the perspective separation type infrared sensor 1, for example, there is almost no relative change in the width of each detection zone d <b> 1 to d <b> 4 that forms a surface warning type warning area, and the outer periphery of the warning area is When trying to change the angle of the distant detector for regulation, the width of the distant warning zone d4 becomes small like d1-1, d4-2, but almost changes in the nearby detection zones d1, d2, etc. There is no need to let them.

  On the other hand, in the case of the conventional infrared sensor shown in FIG. 9, a large relative change occurs in the widths of the detection zones e1 to e6, and the detection zones e1 and the like in the vicinity are too large for the intruder. The zone e6 and the like are smaller with respect to the intruder, and there is no difference between the ratio of the projected area of the small animal and the ratio of the projected area of the intruder to the detection zone e1, so the nearby detection zone e1 and the like Increasing the sensitivity of the detector for detecting intruders in the country may detect distant small animals and cause false alarms.

  That is, in the perspective separation type infrared sensor 1, the warning area is separated into a plurality of independent detectors, so that a detector that warns far away does not need to have a nearby detection zone. Therefore, even if the angle of the detector that guards the distance is adjusted to shorten the longest warning distance, it will not be changed to the angle of the nearby detection zone as in the past, and as a result, the size of the detection zone In particular, the balance of the size of the detection zones in the distance and the vicinity is small, and it is difficult to fall into a state that cannot be covered with the frequency characteristics set for each detector with respect to the moving speed of the detection target. In addition, since the detectors are separate for the distant and the vicinity, false alarms caused by small animals in the distant detection zone can be reduced by reducing the sensitivity of only the distant detector.

  Furthermore, since the detector of the infrared sensor 1 has a plurality of detectors, even if the detection zone of the detector that warns the distance and the detection zone of the detector that warns the vicinity overlap, a heat source (moving object) that enters there Are detected without being affected by each other in each detector, and if necessary, it is judged as a single independent signal from multiple detectors, or it is judged by calculation processing. It can be handled as a single detector. For example, if the number of detections (pulse count number) is set to a certain value across multiple detectors, the detection zones in the vicinity, which usually tend to be dense and have a high number of detections, do not overlap and are detected on the far side. Since the zones overlap, the number of detections tends to be more uniform with respect to the movement distance of the heat source regardless of the location in the alert area. Moreover, since the detection frequency can be set independently for each detector, the detection performance in the alert area can be made more uniform.

  On the other hand, in the conventional infrared sensor, the angles of all the detection zones are changed, and if the optical system that warns the distance and the optical system that warns the vicinity are separated without making the detector independent. Even if there is, in that method, if the angle of only the optical system that guards the distance is adjusted to shorten the longest guard distance, the detection zone of the optical system that guards the distance and the detection zone of the optical system that guards the vicinity When overlapped, the overlapping detection zone becomes more sensitive than the non-overlapping detection zone, and even if a disturbance element with relatively low energy is applied to the intruder, such as a small animal, the alert threshold A detection signal exceeding 1 can be obtained, which may cause false alarms.

  Furthermore, in the far-infrared separation type infrared sensor 1, since a plurality of detectors are independent, for example, when the focal length of an optical system that forms a far detection zone is made shorter than before in order to reduce the size, for example. Thus, the amplification factor of the detector that forms the distant detection zone can be increased without affecting the detector that forms the detection zone in the vicinity, thereby reducing the size without degrading the detection performance.

  In contrast, conventional infrared sensors tend to have lower sensitivity because the detection zone in the distance is larger and lower in sensitivity, but the detection zone in the vicinity tends to be smaller and higher in sensitivity. For the collapse, some adjustments were made by changing the aperture of the optical system forming the detection zone to achieve a balance. However, in order to reduce the detection zone that tends to be large when forming a remote detection zone, in an optical system that takes a long focal length, the sensitivity tends to be low, so it is required to further increase the aperture. This is in conflict with the downsizing of existing sensors, and it is difficult to perform sufficient adjustment. Thus, it can be said that the infrared sensor 1 according to the present invention has many advantages over the conventional infrared sensor.

  In the above embodiment, the detectors 3 to 5 are arranged in a substantially triangular shape in the housing 2 as three detectors 3 to 5 having a warning distance in the vicinity, middle and distance, but the present invention has this configuration. Without limitation, for example, two detectors for near and far warning distances can be arranged on the base 2a in the diametrical vertical position or in the diametrical horizontal position, or four or more detections It is also possible to arrange the vessels in a predetermined arrangement. In the above embodiment, the number of detectors, the form of the optical system, the structure of the base and cover of the infrared sensor, the block diagram of the control system, etc. are only examples. For example, a lens is used as the optical system. The present invention can be changed as appropriate without departing from the gist of the invention.

  The present invention is not limited to a passive infrared sensor in which a plurality of detectors are arranged on a disk-shaped base, but a plurality of detectors each including an infrared detection element and an optical system are arranged in a casing having a base having various shapes. It can be used for all passive infrared sensors.

The perspective view which shows one Embodiment of the passive type infrared sensor concerning this invention Conceptual diagram showing the internal configuration Block diagram of the control system Flow chart showing an example of the operation Flow chart showing an example of other operations Plan view and side view showing the three-dimensional warning type warning area Plan view and side view of the same area Explanatory drawing of the warning area of the perspective separation type infrared sensor Explanatory drawing of warning area of conventional infrared sensor

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Passive infrared sensor, 2 ... Housing, 2a ... Base, 2b ... Cover, 3-5 ... Detector, 3a ... Mirror, 3b ... Pyroelectric element, 3c: amplification / filter unit, 4a, 5a ... mirror housing, 4b, 5b ... pyroelectric element, 4c-5c ... amplification / filter unit, 6, 7 ... element substrate, 8d ..Mirror, 9 ... support plate, 11 ... signal processing unit, 11a ... determining unit, 11b ... storage unit, 12 ... setting unit, 12a-12g ... setting switch, 13 ... Output unit, S ... Human body detection signal.

Claims (1)

An optical system that collects infrared rays in a warning area composed of a plurality of fan-shaped detection zones in plan view, and an infrared detection element that detects the infrared rays collected by the optical system, disposed in a casing made up of a base and a cover A detector having a signal processing means for processing a detection signal detected by the detector, and a setting means connected to the signal processing means,
Each of the detectors includes a plurality of detectors having different warning distances, each of which has the optical system and an infrared detection element and is arranged close to each other so that the angle can be individually adjusted.
The setting means can set the sensitivity and the number of detections of the plurality of detectors, whether or not to use them, and the number of detections in the whole of the plurality of detectors, and the signal processing means can set whether or not to use all the detectors. If the passive type in which the plurality of detectors, wherein the output enable der benzalkonium a human body detection signal upon detecting a human body in either detector each signal detected alone processed and with Infrared sensor.

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