JP4660664B2 - Security sensor with light attenuation plate - Google Patents

Description

  The present invention relates to a security sensor that detects an intruder by blocking a detection line transmitted from a projector to a light receiver, and more particularly to a security sensor that attenuates the amount of light of a detection line according to the distance between the projector and the light receiver.

  2. Description of the Related Art Conventionally, there is known a security sensor in which a projector and a light receiver are provided opposite to walls at both ends of a linear guard area such as a guard distance of 100 m. In this security sensor, the light projector has a light projecting element such as an infrared light emitting diode, and an output mirror that reflects the infrared light generated from the light projecting element and emits an infrared beam directed in a certain direction. A light receiving element that receives the infrared beam from the light projecting element and a condensing mirror in which the light receiving element is disposed at the focal position are arranged so that the optical axes of the light projector and the light receiver coincide with each other. When an intruder acts by an intruder is detected by blocking the infrared beam transmitted to the light receiver, an alarm signal is output to notify that there has been an illegal intrusion (for example, Patent Document 1).

In this security sensor, it is necessary to adjust the light quantity of the infrared beam projected and received according to the guard distance. For example, when the amount of light is adjusted corresponding to a warning distance of 100 m, if this amount of light is applied to a warning distance of 50 m, the amount of light will be saturated, and the intruder may not be detected properly. For this reason, in conventional devices, for example, a masking tape or the like is affixed to the output mirror to cover a part of the output mirror and attenuate the amount of the emitted infrared beam so that it can be properly detected. Was.
JP 2002-279538 A

  However, the determination of how much the mirror portion is covered in accordance with the warning distance depends on the operator's experience and intuition, and may not be adjusted properly. Moreover, it is cumbersome to adjust the amount of light each time according to the warning distance.

  An object of the present invention is to solve the above-described problems and provide a security sensor having a light amount attenuating plate capable of appropriately adjusting the light amount of a detection line with a simple operation.

In order to achieve the above object, a security sensor having a light quantity attenuating plate according to the present invention includes a light projecting element and an output mirror that emits a detection line beam that reflects a detection line generated from the light projecting element and travels in a certain direction. And a light receiving element that receives a detection line from the light projecting element and a light receiving element that has a condensing mirror in which the light receiving element is disposed at a focal position, and intercepts the detection line transmitted from the light projector to the light receiving element. A security sensor for detecting an intruder by arranging a plurality of identically shaped plates having a plurality of through-holes on the front surface of at least one of the output mirror and the collecting mirror, and the posture of at least one plate Is provided with a light amount attenuating plate in which the amount of attenuation of the light amount is variable by being different from the posture of other plates. The light amount attenuating plate has a line-symmetric outer shape, and is composed of two pieces having the same shape in which the arrangement of the plurality of through holes is left-right or vertically asymmetric. The amount of attenuation is variable.
Here, the posture of the light amount attenuating plate means a posture in which a plurality of plates are reversed from each other, a posture in which a plurality of plates are displaced from each other by a predetermined rotation angle in the horizontal direction, and the like.

According to this configuration, a plurality of identically shaped light attenuation plates having a plurality of through-holes are stacked on the front surface of at least one of the output mirror and the condensing mirror, and the posture of at least one light attenuation plate is different. The amount of attenuation of the light amount is varied by being different from the posture of the plate. Accordingly, the light amount of the detection line can be attenuated to a predetermined amount by a simple operation, and appropriate adjustment can be made according to the warning distance. Further, since the light amount attenuation plates have the same shape, it is not necessary to create a plurality of types of light amount attenuation plates, so that the cost can be reduced. In addition, the amount of attenuation of the light amount can be easily varied by simply stacking the two light amount attenuation plates upside down.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a side view showing a security sensor having a light amount attenuating plate according to the first embodiment of the present invention. As shown in the figure, the security sensor includes a light projecting unit 1 having a light projector 2 that emits a detection line such as an infrared beam IR, and a light receiver 9 that receives the infrared beam IR emitted from the light projector 2. The light projecting unit 1 and the light receiving unit 8 are attached to face walls W at both ends of a linear warning area such as a warning distance of 100 m, for example.

  This security sensor is arranged so that the optical axis of the light receiver 9 coincides with the projector 2, and an intruder act by an intruder is detected by blocking the infrared beam IR transmitted from the projector 2 to the light receiver 9. Then, an alarm signal is output to notify the security center 5 and the like that an illegal intrusion has occurred.

  FIG. 2 is a perspective view showing the light projecting unit 1. In this example, the light projecting unit 1 has upper and lower light projectors 2. The light receiving unit 8 has the same configuration, and in the same figure, symbols corresponding to corresponding parts in the light receiving unit 8 are also attached. The projector 2 includes a light projecting element 3 such as an infrared light emitting diode, an output mirror 24 that reflects the infrared light generated from the light projecting element 3 and emits an infrared beam IR directed in a certain direction, and an opening of the output mirror 24. And a mirror cover 36 that covers the side surface. The light receiver 9 includes a light receiving element 10 such as a photodiode that receives the infrared beam IR from the light projecting element 3, a condensing mirror 24 in which the light receiving element 10 is disposed at the focal position, and the condensing mirror 24. And a mirror cover 36 that covers the side of the opening with a side surface.

  In the projector 2, two plates having the same shape having a plurality of through-holes are stacked on the front surface of the output mirror 24, and the posture of one plate is different from the postures of the other plates. A light amount attenuation plate 50 is provided in which the amount of attenuation (attenuation rate) of the light amount can be varied. As shown in FIG. 3A, the light amount attenuating plate 50 has, for example, a line-symmetric outer shape, a plurality of through holes 51 provided at equal intervals in the vertical and horizontal directions, and a vertical center line O1 of the plate. The left and right hole centers are slightly shifted from the center line O1 of the plate to the left or right (X-axis direction) by a shift amount S. Note that the through hole 51 may be asymmetrical in the vertical direction and the hole center may be slightly shifted in the vertical direction (Y-axis direction).

  The light quantity attenuation plate 50 in FIG. 3A is provided with, for example, a pair of claw portions 53 extending outward on both sides thereof, and the two plates are stacked in the front-rear direction (in a direction perpendicular to the paper surface). When the claw portion 53 is also overlapped in the front-rear direction, it is inserted into the groove portions 34 provided on the side of the mirror cover 36, so that the two light quantity attenuation plates 50 are attached to the front surface of the output mirror 24. .

  In FIG. 3B, the two light quantity attenuation plates 50a and 50b are arranged in the same direction, that is, with the light quantity attenuation plates 50a and 50b both exposing the surface 50aa and the surface 50ba. Since the through holes 51 overlap at the same position, the opening area of the light amount attenuation plate 50 is the same as that of one sheet. At this time, the projecting rate of the infrared beam IR projected from the projector 2 is, for example, 75% when the light attenuation plate 50 is not provided, and is 75%, that is, the attenuation rate is 25%.

  In FIG. 3C, one of the two light quantity attenuating plates 50 is turned upside down and reversed (in the opposite direction) and overlapped. The plate 50b is arranged so that the surface 50ba is exposed, and the through hole 51 is shifted in the position of the through hole 51 of the two plates by the amount of lateral displacement of the hole center from the plate center line. The opening area of the light quantity attenuation plate 51 is reduced. At this time, the projecting rate of the infrared beam IR projected from the projector 2 is, for example, 50%, that is, the attenuation rate is 50%.

  The light amount attenuating plate 50 can be set to a predetermined attenuation when two plates are stacked in the same direction depending on the diameter, the number of holes, the positions of the holes, and the like. The amount of deviation can be set to a predetermined attenuation when the two plates are stacked in the opposite direction.

  In FIG. 2, the light projecting unit 1 includes a mounting base 33 that is attached to a mounting surface such as a wall portion, and a cover 35 that covers the entire sensor circuit that is detachably attached to the mounting base 33. An outer case is constructed. The sighting device 4 used for coarse adjustment of the optical axes of the projector 2 and the light receiving device 9 includes a pair of left and right observation windows 20 and a pair of left and right sighting holes 21 on the front side, and a pair of bearings projecting on both side surfaces of the rear part. A cylindrical portion 28 is provided. An aiming mirror (not shown) is disposed inside the aiming hole 21 on the aiming axis. As an optical axis adjusting mechanism, a rotating plate 37 is provided on the upper and lower portions of the terminal block case 39 provided at the center of the mounting base 33 so as to be rotatable about the vertical axis (h direction). A pair of support plates 29 is fixed to the plate 37 perpendicularly thereto, and an operation plate 38 is fixed to the outer surface of the support plate 29. By rotating the operation plate 38, for example, the horizontal angle of the light receiver 9 is roughly adjusted. Fine adjustment is performed by rotating the adjustment screw 40 in the forward and reverse directions. Further, a pair of left and right bearing tube portions 28 of the sighting device 4 are rotatably fitted around the support shaft 30 of the support plate 29 and are rotatably supported around the support shaft 30 (around the v direction). The rotation of the receiver 4 around the support shaft 30 is performed by rotating the adjusting screw 41 in the forward and reverse directions, and the vertical angle of the light receiver 9 is variably adjusted.

  Hereinafter, the operation of the security sensor having the light amount attenuation plate having the above-described configuration will be described with reference to FIGS. In this security sensor, for example, when adjusting the light quantity of the infrared beam IR to be projected according to the warning distance, for example, at a warning distance of 100 m, the two light quantity attenuation plates 50 are arranged in the same direction as shown in FIG. By arranging in an overlapping manner, the attenuation rate of the infrared beam IR is adjusted to 25% (projection rate: 75%). When the warning distance is 50 m shorter than 100 m, the light quantity is saturated at the attenuation rate of FIG. 3B adjusted at the warning distance 100 m. Therefore, one of the two light quantity attenuation plates 50 as shown in FIG. By turning the sheets upside down (in the opposite direction) and arranging them in an overlapping manner, the attenuation rate of the infrared beam IR is adjusted to 50% (light projection rate 50%). In this way, the amount of attenuation of the light amount of the infrared beam IR can be easily varied from 25% to 50% simply by arranging two light amount attenuation plates 50 having the same shape in accordance with the warning distance. Can do.

  When all of the two light quantity attenuation plates 50 are removed, the attenuation rate of the infrared beam IR projected from the projector 2 is 0% (projection rate 100%), which is a long warning distance. Used for a warning distance of 150 m, for example, where a larger amount of light is required.

  In this embodiment, the light amount attenuating plate 50 is disposed only on the front surface of the output mirror 24 of the projector 2, but only on the front surface of the condenser mirror 24 of the light receiver 9 or on the output mirror 24 and the light receiver of the projector 2. The light amount attenuating plates 50 may be arranged in front of both of the nine condenser mirrors 24.

  FIG. 4 is a schematic diagram showing a light amount attenuation plate 60 of the second embodiment. For convenience of explanation, FIG. 4 shows only four through holes 61, for example, but in actuality, a large number of holes are provided. As shown in FIG. 4A, the light amount attenuating plate 60 has, for example, a plurality of through-holes 61 provided at equal intervals in the vertical and horizontal directions and asymmetrical with respect to the vertical center line O1 of the plate. In other words, the left and right hole centers are slightly shifted from the center line O1 to the left or right (X-axis direction) by a deviation amount S, and are asymmetrical with respect to the horizontal center line O2 of the plate and vertically (Y-axis direction) is slightly shifted by a shift amount S1. Other configurations of the second embodiment are the same as those of the first embodiment.

  FIG. 4B shows the case where two light amount attenuation plates 60 and 60a having the same shape are used, and the light amount rotated 90 ° counterclockwise in the horizontal direction from (A) on the light amount attenuation plate 60. The attenuation plate 60a is superposed. FIG. 4C shows a case in which three light quantity attenuation plates 60, 60a, 60b having the same shape are used, and further on from the state of (B), and 180 in the counterclockwise direction from (A) in the horizontal direction. This is a superposition of the rotated light quantity attenuation plates 60b. FIG. 4 (D) shows the case where four light quantity attenuation plates 60, 60a, 60b, 60c having the same shape are used. Further, from the state of (C), it is further rotated counterclockwise from (A) to the horizontal direction. A light amount attenuation plate 60c rotated by 270 ° is superposed. In order from (B) to (D), the opening portion of the hole becomes smaller and the attenuation rate becomes larger (the light projection rate becomes smaller). The light amount attenuating plate 60 is provided with, for example, claw portions (not shown) that extend outward on four side portions, respectively, and the grooves 34 and 34 of the mirror cover 36 in FIG. Insert and attach.

  As described above, in the present invention, a plurality of light amount attenuation plates 50 and 60 having the same shape and having a plurality of through holes 51 and 61 are arranged on the front surface of at least one of the output mirror 24 and the collecting mirror 24, Since the amount of attenuation of the light amount is varied because the posture of at least one light amount attenuation plate 50, 60 is different from the posture of the other plates, the light amount of the detection line can be attenuated to a predetermined amount by a simple operation. It is possible to adjust appropriately according to the warning distance. Further, since the light amount attenuation plates 50 and 60 have the same shape, it is not necessary to create a plurality of types of light amount attenuation plates, so that the cost can be reduced.

  In each of the above embodiments, an infrared beam is used as the detection line. However, an ultrasonic wave or a reflected wave in which a radio wave is reflected by a human body may be used.

It is a side view showing a security sensor which has a light quantity attenuation board concerning a 1st embodiment of the present invention. It is a perspective view which shows the light projection unit which has the light projector of the security sensor of FIG. It is a block diagram which shows the light quantity attenuation | damping board of FIG. It is a block diagram which shows the light quantity attenuation | damping plate which concerns on 2nd Embodiment of this invention.

Explanation of symbols

2: Projector 3: Projector 9: Receiver 10: Receiver 24: Output mirror (condenser mirror)
50, 60: Light quantity attenuation plate 51, 61: Through hole IR: Infrared beam

Claims (1)

A projector having an exit mirror that emits a detection line beam that reflects a detection line generated from the light projecting element and the light projecting element and emits a detection line beam directed in a certain direction, and a light receiving element that receives the detection line from the light projecting element and receives light at a focal position A security sensor for detecting an intruder by blocking a detection line transmitted from the light projector to the light receiver, including a light receiver having a condenser mirror on which the element is disposed,
By placing a plurality of identically shaped plates having a plurality of through holes on the front surface of at least one of the output mirror and the collecting mirror, and the posture of at least one plate is different from the posture of the other plates A light amount attenuation plate is provided to vary the amount of light attenuation .
The light amount attenuating plate has two lines having the same shape, having a line-symmetric outer shape and a plurality of through-holes arranged left-right or vertically asymmetric, and the two plates are stacked upside down. The crime prevention sensor which has a light quantity attenuation | damping board by which attenuation amount of light quantity is variable by this .

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