JP2011247726A - Human body detection sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a human body detection sensor capable of obtaining an ideal arrangement for a detection sensor with one detection sensor which is not influenced by attached height or a maximum vigilance distance and detects a human being in both a distant range as well as a close range without detecting a small animal in various environments of attachment.SOLUTION: An optical system of a first optical unit forms a detection sector for the distant range and the close range in a horizontal direction from the human body detection sensor and an optical system of a second optical unit is composed of optical systems for the distant range and the close range for forming the detection sectors for the distant range and the close range in the horizontal direction from the human body detection sensor. The optical system for the distant range and the optical system for the close range are oscillated in the vertical direction independently from each other.

Description

  The present invention relates to a human body detection sensor that detects heat rays radiated from a human body and detects the presence or absence of a person in a detection region.

  Conventionally, a security system has been used in which a sensor for detecting an abnormality is provided on the security target facility side of a general home, store, factory, etc., and the abnormality information is reported to the security center device of the security center via a security terminal. ing. And as a sensor which detects abnormality, there exists a human body detection sensor which detects the penetration | invasion into a guarded facility. This human body detection sensor detects a heat ray radiated from a human and detects the presence or absence of the human in a warning area.

  More specifically, the human body detection sensor forms a detection sector of a heat ray incident on an infrared detector using an infrared detection element having sensitivity in a wavelength region of a heat ray such as a pyroelectric element by a condensing optical system, When the heat ray emitted from the object in the detection sector is condensed on the infrared detector, and the fluctuation amount of the energy of the heat ray from the detection sector based on the output of the infrared detector exceeds a predetermined level It is configured to detect the intrusion of a moving object such as a human into the detection sector, and is widely used for the detection of intruders in automatic door opening and closing and security security systems.

  However, since the infrared detection element, which is a pyroelectric element used in the human body detection sensor, detects heat rays, there is a possibility that a false report is generated by a small animal that emits heat rays other than humans. Therefore, in human body detection sensors, various countermeasures for detecting only humans and preventing false alarms by small animals have been proposed, and as one of them, a plurality of detection sectors are configured, There is known a method for distinguishing a human from other non-detection objects by taking an AND of signals.

  As a method for discriminating between this human and other non-detection objects, there is one disclosed in Patent Document 1, for example. In Patent Document 1, the detection sector of the other optical unit (described as “detection zone” in Patent Document 1) is above or below the detection axis of one of the pyroelectric elements by combining the pyroelectric element and the optical system. Is set. Both detection axes are arranged with an appropriate interval (gap) so as not to overlap (so that the distance from the human body detection sensor is not the same). And the false alarm by the small animal is reduced by taking AND from both detection sectors. At this time, the small animal non-detection performance is determined by the size of the gap of the detection axis. Furthermore, as the detection axis is directed downward, the gap between the upper detection axis and the lower detection axis, which is a gap, increases. This is effective if “detection axis is directed downward” = “longest warning distance is shortened”.

JP-A-10-213673

  However, there are various environments in which this type of human body detection sensor is attached, and in addition to the length of the longest warning distance, the attachment height such as the height of the ceiling varies depending on the situation. The distance that the human body detection sensor warns is not one, and there are many cases where a single human body detection sensor warns both near and far from the human body detection sensor. One optical system is composed of a plurality of parabolic mirrors, Fresnel lenses, and the like, each of which plays a role of forming individual detection sectors in the alert area. The optimum setting of the gap differs depending on the distance from the human body detection sensor to each detection sector. This is because the size of a human or a small animal viewed from the human body detection sensor changes depending on this distance.

  Generally, for a detection sector at a short distance from the human body detection sensor, the distance from the human body detection sensor to the detection sector (detection surface) is greatly influenced by the mounting height of the human body detection sensor. When the detection sector is considered at a position far from the human body detection sensor, the distance from the human body detection sensor to the detection sector is affected by the warning distance (horizontal distance). Considering the detection sector at a short distance from the human body detection sensor, it is desirable to set the optimal gap according to the mounting height, and it is desirable to set the optimal gap for the long distance detection sector according to the warning distance. However, in the conventional human body detection sensor, although the gap is changed depending on the warning distance, the mounting height is not supported.

  In the conventional human body detection sensor, two methods are introduced as means for controlling the gap between detection sectors formed by two pyroelectric elements. In Patent Document 1, there is only a description of one detection axis, but in reality, there are many cases where a long distance and a short distance are warned by one human body detection sensor. In the method of changing the distance between the dual twin sensors, if the gap at a long distance is increased, the gap at a short distance is also increased in the same manner. Also, in the method using two optical units, the direction of the optical axis is controlled by the rotation of the optical unit, and each of these optical systems is composed of one, and this method also uses a gap between a long distance and a short distance. Cannot be controlled independently (the orientations of the detection sectors at long and short distances cannot be controlled independently). Therefore, neither of the methods can control the distance between the long distance and the short distance to an optimum size.

  Here, the long distance and the short distance are not determined by the absolute distance from the human body detection sensor, but indicate a relative positional relationship such as the far side and the near side. When a long distance and a short distance are captured by the human body detection sensor, for example, a distance that is longer than the longest distance and a distance that is shorter than the longest distance based on the distance that is approximately half of the longest distance that the human body detection sensor can watch. Although it can be considered as a short distance, this is only a guide for explanation and is not limited to this.

  First, consider the short-range detection sector. Since the conventional human body detection sensor does not support a change in the mounting height of the human body detection sensor, the gap is set in accordance with a specific height. For example, as shown in FIG. 11A, when the optical systems of the short-distance detection sectors AW and BW are set according to the case where the mounting height is high, the gap a is formed if the optical system is set at a low position as it is. It becomes small and the possibility that the false alarm is generated by the small animal M increases. On the contrary, as shown in FIG. 11B, when the optical systems of the short-distance detection sectors AW and BW are set according to the case where the mounting height is low, the gap b is formed when the optical system of the detection sector AW or BW is mounted at a high position as it is. It becomes large and the possibility that the person H will be misreported (not detected when it must be detected) increases.

  In the conventional human body detection sensor, this gap is increased by “facing the detection axis downward”, but the fact that the detection axis is directed downward and the mounting height is low does not coincide with each other in terms of function. Even when the mounting height is increased, the detection axis must be directed downward. Therefore, both humans and small animals can be accurately identified to suppress false alarms regardless of whether the mounting height is high or low. I can't.

  For the same reason, when the optical system of a long-distance detection sector is designed for a case where the longest guard distance is short, the gap becomes large under the condition where the longest guard distance is long, and there is a high possibility that humans will be reported. On the other hand, when designed for the case where the longest guard distance is long, the gap becomes small under the condition where the longest guard distance is short, and there is a high possibility that a false report will be generated by a small animal.

  The present invention has been made in view of such circumstances, and it is possible to detect humans in both a long distance and a short distance in various mounting environments without being affected by the mounting height and the longest warning distance. An object of the present invention is to provide a human body detection sensor capable of obtaining an ideal arrangement of detection sectors that does not detect small animals.

  The human body detection sensor according to claim 1, wherein the optical system of the first optical unit forms detection sectors for long distance and short distance in the horizontal direction from the human body detection sensor, and the optical system of the second optical unit. The system consists of a long-distance optical system and a short-distance optical system that form a long-distance and short-distance detection sector in the horizontal direction from the human body detection sensor. The system swings in the vertical direction independently of each other.

  The human body detection sensor according to claim 2 is characterized in that the optical system of the first optical unit swings in the vertical direction.

  The human body detection sensor according to claim 3, wherein the optical system of the first optical unit includes a long-distance optical system and a short-distance optical system that form respective detection sectors in the horizontal direction from the human body detection sensor. Thus, the long-distance optical system and the short-distance optical system swing in the vertical direction independently of each other.

  The human body detection sensor according to claim 4, wherein the elevation gap between the long-distance detection sector of the optical system of the first optical unit and the long-distance detection sector of the optical system of the second optical unit is arbitrarily set The gap of the elevation angle between the short-distance detection sector of the optical system of the first optical unit and the short-distance detection sector of the optical system of the second optical unit can be arbitrarily set. It is characterized by.

  6. The human body detection sensor according to claim 5, wherein the human body detection sensor is provided on each optical axis of the optical system of the first optical unit or the optical system of the second optical unit, and is a sensitivity for blocking a part of light entering each of the optical systems. An adjustment plate is provided, and the amount of blocking by the sensitivity adjustment plate can be increased or decreased. The sensitivity of the pyroelectric element is adjusted by changing the amount of light entering the optical system by the sensitivity adjustment plate.

  The human body detection sensor according to claim 6 is characterized in that the amount of light blocked by the sensitivity adjusting plate can be changed according to the elevation angle of the optical system.

  According to the first to fourth aspects of the present invention, the angle relationship between the detection sector of the first optical unit and the detection sector of the second optical unit can be set as appropriate. Now, it is possible to obtain an ideal detection sector arrangement that detects humans at various distances and short distances and does not detect small animals without being affected by the longest warning distance.

  According to the invention of claim 5, the sensitivity of the pyroelectric element is adjusted by changing the amount of light entering the optical system by the sensitivity adjustment plate, and various effects can be obtained without being affected by the mounting height and the longest warning distance. In an installation environment, it is possible to obtain an ideal setting in which a human is detected at both a long distance and a short distance and a small animal is not detected.

  According to the sixth aspect of the present invention, the amount of light blocked by the sensitivity adjusting plate can be changed according to the elevation angle of the optical system. The sensitivity of the element can be adjusted.

It is a block diagram which shows the human body detection sensor of 1st Example which concerns on this invention. It is explanatory drawing which shows the structure of the optical unit of a human body detection sensor. It is explanatory drawing which shows operation | movement of a human body detection sensor. It is explanatory drawing which shows operation | movement of a human body detection sensor. It is explanatory drawing which shows the structure of the other optical unit of a human body detection sensor. It is a block diagram which shows the human body detection sensor of 2nd Example based on this invention. It is explanatory drawing which shows the structure of the optical unit of a human body detection sensor. It is explanatory drawing which shows the structure of the other optical unit of a human body detection sensor. It is explanatory drawing which shows the optical unit of the human body detection sensor of 3rd Example based on this invention. It is explanatory drawing which shows the other example of the optical unit of a human body detection sensor. It is explanatory drawing which shows operation | movement of the conventional human body detection sensor.

  The human body detection sensor according to the embodiment of the present invention detects heat rays radiated from the human body and detects the presence or absence of a human in the detection area. In the following, the terms long distance and short distance are used, but the long distance and short distance are not determined by the absolute distance from the human body detection sensor, but are relative to the far side and the near side. This indicates a general positional relationship. When a long distance and a short distance are captured by the human body detection sensor, for example, a distance that is longer than the longest distance and a distance that is shorter than the longest distance based on the distance that is approximately half of the longest distance that the human body detection sensor can watch. Although it can be considered as a short distance, this is only a guide for explanation and is not limited to this.

  Further, in the following, the terms “mounting height” and “mounting height” are used as the mounting height of the human body detection sensor. However, “high” and “low” means the absolute height of the ceiling to which the human body detection sensor is mounted. It is not determined by a typical numerical value, but indicates a relative positional relationship that may affect detection of humans and small animals by the size of a gap described later. When the human body sensor detects high mounting height and low mounting height, for example, the maximum mountable height and the minimum height determined by the relationship with the maximum detectable distance of the human body sensor If it is higher than that, the mounting height is high, and if it is lower, the mounting height is low, but this is only a guideline for explanation, It is not limited.

  Hereinafter, the present embodiment will be specifically described with reference to the drawings. FIG. 1 is a block diagram showing a human body detection sensor according to a first embodiment of the present invention. FIG. 2 is an explanatory view showing the structure of the optical unit of the human body detection sensor. FIG. 3 is an explanatory diagram showing the operation of the human body detection sensor. FIG. 4 is an explanatory diagram showing the operation of the human body detection sensor. FIG. 5 is an explanatory view showing the structure of another optical unit of the doubling body detection sensor.

  1 to 5 includes an optical unit A10, an optical unit B20, a signal processing circuit A30, a signal processing circuit B40, and a determination unit 50. The optical unit A10 and the optical unit B20 are an optical system A14, a long-distance optical system B24, a short-distance optical system B26, and an optical system A14, a long-distance optical system. B24 and pyroelectric element A12 and pyroelectric element B22 for detecting the heat rays condensed on short-distance optical system B26 are provided.

  The pyroelectric element A12 and the pyroelectric element B22 are twin-type elements having two infrared detection elements. However, the pyroelectric element A12 and the pyroelectric element B22 do not necessarily need to be twin-type elements. If it is something, it is not limited. In addition, by using a twin type for the pyroelectric element A12 and the pyroelectric element B22, for example, even when disturbance light is incident on both of the two infrared detection elements, the outputs of the infrared detection elements cancel each other. Therefore, it is strong against background noise such as disturbance light, and can prevent false reports due to disturbance light.

  The optical system A14, the long-distance optical system B24, and the short-distance optical system B26 condense the heat rays radiated from the body of the human H onto the pyroelectric element A12 and the pyroelectric element B22. The arrangement of the detection sectors of the pyroelectric element B22 is formed. In the optical system A14, the paraboloidal mirror has two upper and lower stages, the lower stage is the long-distance optical system A14a, and the upper stage is the short-distance optical system A14b. The long-distance optical system A14a forms a long-distance detection sector AT, and the short-distance optical system A14b forms a short-distance detection sector AW. The optical system A14 swings in the vertical direction with respect to the pyroelectric element A12, so that the detection sectors AT and AW swing in the vertical direction. In this embodiment, only the optical system A14 is oscillated. However, when the entire optical unit A10 including the pyroelectric element A12 is oscillated in the vertical direction, the detection sectors AT and AW are vertically You may make it rock | fluctuate in a direction.

  Here, for the long distance and the short distance, it is premised that two names are used to configure the detection sectors AT and AW of different distances. In addition, for the long distance and the short distance, the distance from the human body detection sensor 1 to the detection sectors AT and AW is not determined by an absolute numerical value, but is a relative positional relationship such as the far side and the near side. Is shown. For example, in the state where the human body sensor 1 is attached, the lower optical system constituting the detection sector AT that warns a longer distance with reference to about half of the farthest distance being warned is a long distance optical The upper optical system constituting the detection sector AW that warns for a shorter distance than the system A14a is the short-distance optical system A14b, but this is only a guideline for explanation, and is not limited to this. Absent.

  On the other hand, unlike the optical unit A10, the optical unit B20 includes two optical systems, a long-distance optical system B24 and a short-distance optical system B26. Each of the long-distance optical system B24 and the short-distance optical system B26 is a parabolic mirror and is arranged in two upper and lower stages. The long-distance optical system B24 forms a long-distance detection sector BT, and the short-distance optical system B26 forms a short-distance detection sector BW. The long-distance optical system B24 and the short-distance optical system B26 swing independently in the vertical direction with respect to the pyroelectric element B22, whereby the detection sectors BT and BW swing in the vertical direction. Become. In this embodiment, the long-distance optical system B24 and the short-distance optical system B26 are oscillated. However, the long-distance optical system B24 and the short-distance optical system B26 are oscillated. The detection sectors BT and BW may be swung in the vertical direction by swinging the entire optical unit B20 including the pyroelectric element B22 in the vertical direction while maintaining the structure.

  As shown in FIG. 2, the optical unit A10 and the optical unit B20 are arranged so as to be shifted up and down, and are detected as a long-distance detection sector AT and a detection sector BT, and a short-distance detection sector AW. The sectors BW are arranged so as not to intersect with each other and to have predetermined gaps a and b.

  The signal processing circuit A30 and the signal processing circuit B40 are composed of amplification circuits 32 and 42, band-pass filters 34 and 44, and comparison circuits 36 and 46. The amplifier circuits 32 and 42 amplify the outputs of the pyroelectric element A12 and the pyroelectric element B22. The band-pass filters 34 and 44 remove only unnecessary frequency components from the outputs of the amplifier circuits 32 and 42 and output only signals having predetermined frequency components. The comparison circuits 36 and 46 compare the signals that have passed through the band-pass filters 34 and 44 with a predetermined threshold, and output a pulse signal when there is a signal equal to or greater than the threshold. The determination means 50 determines that the person H as the detected object has been detected from the AND of the two pulse signals from the signal processing circuit A30 and the signal processing circuit B40, and outputs a detection signal.

  The human body detection sensor 1 according to the present embodiment divides one optical system of the two optical units A10 and B20 into two for long distance and short distance, so that the mounting height of the human body detection sensor 1 and the longest warning It is possible to adjust the long distance and short distance gaps according to the distance. In this way, for example, when the longest warning distance is long and the mounting height is low, the short distance gap (gap b in FIG. 4) can be increased while the long distance gap (gap a in FIG. 3) is reduced. it can. For example, when the longest warning distance is short and the mounting height is high, the short distance gap (gap b in FIG. 4) can be reduced while increasing the long distance gap (gap a in FIG. 3).

  More specifically, for example, when comparing “when the longest warning distance is short” and “when the longest warning distance is long”, the size of the human H and the small animal M viewed from the human body detection sensor 1 is determined from the human body detection sensor. The smaller the distance, the smaller (see FIG. 3). First, consider a case where a relatively long distance is warned (FIG. 3A). At this time, since the small animal viewed from the human body detection sensor 1 is sufficiently small, the gap a need not be increased. If this gap a is set large, the possibility that the human H will not be detected increases. When guarding a relatively short distance (FIG. 3 (b)), the small animal M viewed from the human body detection sensor 1 cannot be said to be sufficiently small, so the gap a ′ is made larger than when the longest guard distance is long. If it is not set, the possibility of misreporting by the small animal M increases. Even if the gap a 'is set to be large, the human H viewed from the human body detection sensor 1 is sufficiently large at this distance, and therefore, the possibility of misreporting is small. As described above, the optimum gap a of the detection sectors AT and BT that warn for a long distance varies depending on the longest guard distance, but in the human body detection sensor 1 of the present embodiment, the elevation angle of the long-distance optical system B24 can be varied independently. By doing so, it becomes possible to adjust to the optimal gap a according to the guard distance.

  Next, “when the mounting height is low” and “when the mounting height is high” are compared. When the mounting height is changed, as shown in FIG. 4, with respect to the detection sectors AW and BW at a short distance from the human body detection sensor 1, the distance from the human body detection sensor 1 to the human H and the small animal M is equal to this height. It is greatly affected. First, considering the case of mounting at a relatively high position, as shown in FIG. 4A, the small animal M viewed from the human body detection sensor 1 is sufficiently small, so that the gap b does not need to be increased. If the gap b is set to be large, the possibility that the human H is not detected increases. As shown in FIG. 4 (b), when attached to a relatively low position, the small animal M viewed from the human body detection sensor 1 cannot be said to be sufficiently small. If it is not set to a large value, the possibility of misreporting by the small animal M increases. Even if the gap b 'is set to be large, the human H viewed from the human body detection sensor 1 is sufficiently large at this distance, and therefore, the possibility of misreporting is small. As described above, the optimum gap b of the detection sectors AW and BW that warn of a short distance varies depending on the mounting height, but in the human body detection sensor 1 of the present embodiment, the elevation angle of the short-distance optical system B26 is independently set. By making it variable, it is possible to adjust to the optimum gap b according to the guard distance.

  Actually, there are various mounting situations, such as when the mounting height is high and the warning distance is short, or when the mounting height is low and the warning distance is long. In the human body detection sensor 1 of this embodiment, It is possible to respond to the situation. Thus, the gap a of the elevation angle between the long-distance detection sector AT of the optical system A14 of the first optical unit A10 and the long-distance detection sector BT of the long-distance optical system B24 of the second optical unit B20. Can be arbitrarily set, and the detection sector AW for the short distance of the optical system A14 of the first optical unit A10 and the detection sector BW for the short distance of the short distance optical system B26 of the second optical unit B20. Can be arbitrarily set, and one human body detection sensor 1 is not affected by the mounting height and the longest warning distance, and can be used in various mounting environments for both long distances and short distances. It is possible to obtain an ideal detection sector arrangement in which the small animal M is not detected. The optical unit A10 and the optical unit B20 may be independently swung, or a structure in which when one of the optical units is swung, the other optical unit is swung in conjunction therewith. In any case, it is arbitrary which one of the optical systems is linked with which one is not linked.

  In addition, although optical unit A10 and optical unit B20 of the human body detection sensor 1 shown in FIG. 2 use a parabolic mirror, it is not limited to a parabolic mirror. For example, as shown in FIG. As the optical system A64, the long-distance optical system B74, and the short-distance optical system B76, lenses (for example, Fresnel lenses) can be used.

  In the case of FIG. 5, the two optical units are arranged completely vertically, and the upper optical unit is one of the optical systems A64, like the optical unit A10, and the upper stage of the optical system A64 is for a long distance. The long-distance optical system A64a that forms the detection sector AT, and the lower stage is the short-distance optical system A64b that forms the short-distance detection sector AW. Similarly to the optical unit B20, the lower optical unit is divided into a long-distance optical system B74 and a short-distance optical system B76, and the upper stage forms a far-distance detection sector BT. In the distance optical system B74, the lower stage is a short distance optical system B76 that forms a short distance detection sector BW.

  The optical system A64 shown in FIG. 5 moves up and down, and the angle of incidence on the pyroelectric element A12 changes. As a result, the elevation angles of the detection sectors AT and AW can be varied. In addition, the long-distance optical system B74 and the short-distance optical system B76 are independently moved up and down to change the angle of incidence on the pyroelectric element B22. As a result, the elevation angles of the detection sectors BT and BW are variable. Can be made. In this way, by moving the optical system A64, the long-distance optical system B74, and the short-distance optical system B76 up and down, the gap a between the long-distance detection sector AT and the detection sector BT and the short-distance detection are detected. The gap b between the sector AW and the detection sector BW can be arbitrarily set.

  In FIG. 5, only the optical system A64 is structured to move up and down. However, when the entire optical unit including the pyroelectric element A12 moves up and down, the detection sectors AT and AW swing in the vertical direction. You may do it. Further, the long-distance optical system B74 and the short-distance optical system B76 each move vertically, but the long-distance optical system B74 and the short-distance optical system B76 each move vertically. The detection sectors BT and BW may be swung in the vertical direction by moving the entire optical unit including the electric element B22 up and down.

  In the first embodiment, the optical system A14 of the optical unit A10 that is the first optical unit is not divided for the long distance and the short distance, but similarly to the second optical unit B20 of the first embodiment. The optical system may be divided into two for long-distance and short-distance, and the short-distance and long-distance gaps may be adjusted according to the mounting height and the longest warning distance. In this embodiment, a case where the optical system is divided will be described. FIG. 6 is a block diagram showing a human body detection sensor according to a second embodiment of the present invention. FIG. 7 is an explanatory view showing the structure of the optical unit of the human body detection sensor. FIG. 8 is an explanatory view showing the structure of another optical unit of the doubling body detection sensor.

  6 to 7 includes an optical unit A11, an optical unit B20, a signal processing circuit A30, a signal processing circuit B40, and a determination unit 50. In the human body detection sensor 2 of the present embodiment, the optical unit B20, the signal processing circuit A30, and the signal processing circuit B40 are the same as those in the first embodiment, and the description thereof is omitted.

  On the other hand, the optical unit A11 in this embodiment includes two optical systems, a long-distance optical system A16 and a short-distance optical system A18, like the optical unit B20. Each of the long-distance optical system A16 and the short-distance optical system A18 is a parabolic mirror and is arranged in two upper and lower stages. The long-distance optical system A16 forms a long-distance detection sector AT, and the short-distance optical system A18 forms a short-distance detection sector AW. The long-distance optical system A16 and the short-distance optical system A18 are independently swung in the vertical direction with respect to the pyroelectric element A12, so that the detection sectors AT and AW are swung in the vertical direction. Become. In the present embodiment, the long-distance optical system A16 and the short-distance optical system A18 are oscillated, but the long-distance optical system A16 and the short-distance optical system A18 are oscillated. The detection sectors AT and AW may be swung in the vertical direction by swinging the entire optical unit A11 including the pyroelectric element A12 in the vertical direction while maintaining the structure.

  As in the first embodiment, the optical unit A11 and the optical unit B20 are shifted up and down as shown in FIG. 7, and the long-distance detection sector AT, the detection sector BT, and the short distance are arranged. The detection sector AW and the detection sector BW are arranged so as not to cross each other and to have predetermined gaps a and b.

  According to the human body detection sensor 2 having such a structure, as in the case of the human body detection sensor 1 of the first embodiment, the mounting height is high and the warning distance is short, or the mounting height is low and the warning distance is long. There are various installation situations, but any situation can be handled. Thus, the elevation angle between the long-distance detection sector AT of the long-distance optical system A16 of the first optical unit A11 and the long-distance detection sector BT of the long-distance optical system B24 of the second optical unit B20. Can be arbitrarily set, and the short-distance detection sector AW of the short-distance optical system A18 of the first optical unit A11 and the short-distance optical system B26 of the second optical unit B20 are close to each other. The elevation gap b with the distance detection sector BW can be set arbitrarily. With one human body detection sensor 2, it is not affected by the mounting height and the longest warning distance. It is possible to obtain an ideal detection sector arrangement that detects the human H at a short distance and does not detect the small animal M.

  Although the optical unit A11 and the optical unit B20 of the human body detection sensor 2 shown in FIG. 7 are parabolic mirrors, they are not limited to parabolic mirrors as in the first embodiment. For example, as shown in FIG. 8, lenses (for example, Fresnel lenses) may be used as the long-distance optical system A84, the short-distance optical system A86, the long-distance optical system B74, and the short-distance optical system B76. . The arrangement of the two optical systems is the same as in FIG. 5 of the first embodiment, but the structure of the optical system related to the pyroelectric element A12 is different, and the optical system related to the pyroelectric element B22 is the same as FIG.

  In the form of FIG. 8, the upper optical unit is divided into two, that is, a long-distance optical system A84 and a short-distance optical system A86, like the lower optical system. Is a short-distance optical system A86 that forms a short-distance detection sector BW. The long-distance optical system A84 and the short-distance optical system A86 independently move up and down independently to change the angle of incidence on the pyroelectric element A12. As a result, the elevation angles of the detection sectors AT and AW are variable. Can be made. As described above, the long-distance optical system A84, the short-distance optical system A86, the long-distance optical system B74, and the short-distance optical system B76 are moved up and down to detect the long-distance detection sector AT and the detection sector BT. And a gap b between the detection sector AW for short distance and the detection sector BW can be arbitrarily set.

  In FIG. 8, the long-distance optical system A84 and the short-distance optical system A86 are vertically moved, but the long-distance optical system A84 and the short-distance optical system A86 are vertically moved. The detection sectors AT and AW may be swung vertically by moving the entire optical unit including the pyroelectric element A12 up and down.

  If the magnitude of the output signal changes depending on the distance from the human body detection sensors 1 and 2 to the human body H or small animal M detected by the detection sectors AT, AW, BT, and BW, the adjustment mechanism of the optical system It is possible to adjust the sensitivity. If the signal increases as the distance from the human body detection sensors 1 and 2 to the human body H or the small animal M detected by the detection sectors AW and BW becomes shorter, it is desirable to adjust the sensitivity so that the sensitivity is reduced. This is because the sensitivity in each of the detection sectors AT, AW, BT, and BW should be set to a sensitivity that is necessary and sufficient to detect human H. If the sensitivity is too high, there is a risk of malfunction due to the small animal M. Because it grows. For example, the sensitivity may be adjusted as shown in FIGS. FIG. 9 is an explanatory diagram showing an optical unit of the human body detection sensor according to the third embodiment of the present invention. FIG. 10 is an explanatory diagram illustrating another example of the optical unit of the human body detection sensor.

  In FIG. 9, a sensitivity adjustment plate 100 that blocks a part of incident light is provided on the optical axis of the short-distance optical system B26. This sensitivity adjustment plate 100 can increase or decrease the amount of light that blocks light entering the short-distance optical system B26. FIG. 9A is a diagram when the guard distance in the detection sector BW is long and the gap is reduced. In FIG. 9A, since the optical path for forming the detection sector BW does not reach the sensitivity adjustment plate 100, the entire surface of the short-distance optical system B26, which is a parabolic mirror, receives heat rays. On the other hand, FIG. 9B is a diagram when the guard distance in the detection sector BW is short and the gap is increased. In order to increase the gap, the direction of the detection axis is changed by changing the direction of the short-distance optical system B26 from the case of FIG. At this time, since the optical path is blocked by the sensitivity adjustment plate 100, the heat rays are received only by a part of the short-distance optical system B26. As a result, compared to the case of FIG. 9A, the energy of the heat rays received by the pyroelectric element B22 is reduced, and the amount of light entering the short-distance optical system B26 optical system is changed by the sensitivity adjustment plate 100. The sensitivity of the pyroelectric element B22 is adjusted.

  FIG. 9 shows a case where a parabolic mirror is used for the short-distance optical system B26. FIG. 10 shows a case where a short-distance optical system B76 which is a Fresnel lens is used. In FIG. 10, a sensitivity adjustment plate 102 that blocks part of incident light is provided on the optical axis of the short-distance optical system B76. This sensitivity adjustment plate 102 can increase or decrease the amount of light that blocks light entering the short-distance optical system B76. In order to change the gap, the position of the short-distance optical system B76 is changed in FIGS. 10 (a) and 10 (b). As in the case of the parabolic mirror, since the optical path is blocked by the sensitivity adjustment plate 102, the energy of the heat rays received by the pyroelectric element B22 is reduced, and the sensitivity adjustment plate 102 enters the short-distance optical system B76. The sensitivity of the pyroelectric element B22 is adjusted by changing the amount of light.

  As described above, the sensitivity of the pyroelectric element B22 is adjusted by changing the amount of light entering the optical system by the sensitivity adjustment plates 100 and 102, and various effects can be obtained without being affected by the mounting height and the longest warning distance. It is possible to obtain an ideal setting in which the human H is detected at both a long distance and a short distance and the small animal M is not detected in the installation environment.

  Furthermore, the sensitivity of the pyroelectric element B22 can be easily adjusted only by setting the state of the optical system by changing the amount of light blocked by the sensitivity adjustment plates 100 and 102 according to the elevation angle of the optical system. Can do. In this embodiment, the sensitivity adjustment plates 100 and 102 are fixed, and the angle and position of the short-distance optical system B26 and the short-distance optical system B76 are changed to change the cutoff amount of the sensitivity adjustment plates 100 and 102. However, the present invention is not limited to such a structure, and the sensitivity adjustment plates 100 and 102 are moved, or both the short-distance optical system B26 and the short-distance optical system B76 and the sensitivity adjustment plates 100 and 102 are moved. It may be adjusted by moving it.

  In the first to third embodiments, one pyroelectric element A12 and pyroelectric element B22 are used for each optical system. However, the number of pyroelectric elements is not limited to one, and detection is possible. It is possible to use different ones for each of the sectors AT, AW, BT, and BW, and the outputs from the pyroelectric elements may be combined and sent to the signal processing circuit A30 or the signal processing circuit B40. It is not limited by.

  As described above, according to the present invention, an ideal device that detects humans at both long and short distances and does not detect small animals in various mounting environments without being affected by the mounting height and the longest warning distance. It is possible to provide a human body detection sensor capable of obtaining a typical arrangement of detection sectors.

DESCRIPTION OF SYMBOLS 1 ... Human body detection sensor 2 ... Human body detection sensor 10 ... Optical unit A
11 .... Optical unit A
12 .... Pyroelectric element A
14. Optical system A
14a ... Optical system A for long distance
14b ... Optical system A for short distance
16 .... Optical system A for long distance
18... Short-distance optical system A
20... Optical unit B
22... Pyroelectric element B
24 .... Optical system B for long distance
26... Short-distance optical system B
30... Signal processing circuit A
32 ... Amplifier circuit 34 ... Band filter 36 ... Comparator circuit 40 ... Signal processing circuit B
42... Amplifier circuit 44... Band filter 46... Comparison circuit 50.
64a ... Long-distance optical system A
64b ... Short-distance optical system A
74 ··· Long distance optical system B
76... Short-distance optical system B
84 .. Optical system A for long distance
86... Short-distance optical system A
DESCRIPTION OF SYMBOLS 100 ... Sensitivity adjustment plate 102 ... Sensitivity adjustment plate H ... Human M ... Small animal AT ... Detection sector AW ... Detection sector BT ... Detection sector BW .... Detection sector F ... Floor L ... Ceiling

Claims (6)

In a human body detection sensor comprising an optical unit having a pyroelectric element and an optical system for condensing the pyroelectric element,
The optical system of the first optical unit forms a detection sector for long distance and short distance in the horizontal direction from the human body detection sensor,
The optical system of the second optical unit includes a long-distance optical system and a short-distance optical system that form a long-distance and short-distance detection sector in the horizontal direction from the human body detection sensor. A human body detection sensor, wherein the optical system for short distance and the optical system for short distance swing vertically independently of each other.   The human body detection sensor according to claim 1, wherein the optical system of the first optical unit swings in a vertical direction.   The optical system of the first optical unit includes a long-distance optical system and a short-distance optical system that form respective detection sectors in the horizontal direction from the human body detection sensor. 2. The human body detection sensor according to claim 1, wherein the short-distance optical system swings in the vertical direction independently of each other. The gap in elevation angle between the long-distance detection sector of the optical system of the first optical unit and the long-distance detection sector of the optical system of the second optical unit can be arbitrarily set,
The elevation gap between the short-distance detection sector of the optical system of the first optical unit and the short-distance detection sector of the optical system of the second optical unit can be arbitrarily set. The human body detection sensor according to any one of claims 1 to 3. Provided on each optical axis of the optical system of the first optical unit or the optical system of the second optical unit, and provided with a sensitivity adjustment plate that blocks a part of the light entering each of them,
2. The sensitivity of the pyroelectric element can be adjusted by changing the amount of light incident on the optical system by the sensitivity adjusting plate, wherein the amount of blocking by the sensitivity adjusting plate can be increased or decreased. The human body detection sensor according to claim 4.   The human body detection sensor according to claim 5, wherein the amount of light blocked by the sensitivity adjustment plate can be changed according to an elevation angle of the optical system.

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