JP2002024952A - Crime prevention sensor with obstruction detecting function - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a crime prevention sensor with an obstruction detecting function of high reliability capable of surely detecting the obstructing conduct in the presence of the obstructing conduct that an obstruction is attached to an outer face of an envelope member on the light entering side of a crime prevention sensor. SOLUTION: A light entering side envelope member displaced or deformed in receiving the pressure, is mounted on a body A having an infrared ray detecting element 4. The light entering side envelope member is composed of a lens 5 for determining a detection area B of the infrared ray detecting element 4, or a cover 28 for covering a plane of the incidence side of the infrared ray detecting element 4. Further light projecting and receiving units 11 and 12 are mounted for detecting the displacement or deformation of the light entering side envelope 5 and 28, and a detecting circuit 15 for detecting the obstructing conduct on the basis of the detection.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technology for adding a function of detecting the attachment of an obstacle such as a seal to a security sensor using a passive infrared element.

[0002]

2. Description of the Related Art An intruder detection system using a security sensor is configured such that a passive infrared element receives far-infrared rays from a human body in a detection area and detects an intruder based on a difference between the human body and an ambient temperature. Have been.

[0003] By the way, an obstructing person enters a room where a security sensor is installed during a non-alarm operation in which many people enter and exit to obstruct the operation of the intruder detection system,
A transparent paint that blocks far-infrared rays and transmits visible to near-infrared rays is applied to the outer surface of the light-incident side surrounding member consisting of the lens or cover of the security sensor where far-infrared rays from the human body enter, or is transparent. There is a case where an obstacle such as a sticker is pasted on and a person enters the room at the time of a warning operation of the intruder detection system in which a person cannot enter or exit.

Japanese Patent Laid-Open No. 2-287 discloses a security sensor provided with an interference detection device for detecting the presence or absence of the above-mentioned obstacle.
There is one disclosed in Japanese Patent Publication No. 278. This interference detection device has a light emitting element and a light receiving element, and a light incident side outer member of a security sensor through which near infrared light or visible light interference detection light from the light emitting element passes through far infrared light from a human body. Then, the light is emitted toward the inner surface of the lens, and the reflected light of the interference detection light beam from the inner surface of the lens is received by the light receiving element.
Based on the amount of received light, the reflected light of the interference detection light beam from the inner surface of the lens is added to the reflected light of the interference detection light beam from the obstacle applied or adhered to the outer surface of the lens. By detecting an increase in the amount of incident light of the interference detection light beam to the element, the presence of an obstacle on the outer surface of the lens is detected.

[0005]

SUMMARY OF THE INVENTION The interference detection device comprises:
When the amount of interference detection light reflected from the obstruction is small relative to the reference amount of light incident on the light receiving element due to stray light of the interference detection light reflected on the inner surface of the lens, the increase due to the reflected light from the interference is reduced. Is difficult to detect.

In particular, when the outer surface of the lens is sprayed with a transparent paint that shields far-infrared rays and transmits near-infrared rays to visible light, which is a light beam for interference detection, an obstacle such as a transparent seal is applied. Is attached closely,
Since the obstruction and the lens are integrated, the amount of reflected light from the obstruction is extremely small, so that the detection of the obstruction becomes more difficult. Visual detection of an object is also difficult.

Hitherto, in order to detect an obstruction such as the transparent seal or the sponge sheet, a method has been proposed in which the amount of change in the interference detection light beam at the moment of applying the obstruction (the actual operation of attaching) is detected. . However, according to this method, it is necessary to constantly monitor the system including the time zone other than the alert time zone, and there is a possibility that a malfunction may occur if the light amount changes due to an external factor.

On the other hand, the security sensor disclosed in Japanese Patent Application Laid-Open No. H11-126282 discloses a security sensor which attaches an obstruction such as a tape for shielding far-infrared rays to an outer surface of a cover which is a light incident side surrounding member. The cover is configured to be displaced with respect to the sensor body (base portion) by the pressing force, and the obstruction is detected by operating a mechanical switch by the displacement of the cover. However, this prior art,
Because it is a mechanical switch, it requires a large space.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is intended to detect a transparent paint applied to the outer surface of a light-incident-side outer member of a security sensor, and to provide a transparent seal. It is an object of the present invention to obtain a security sensor with a reliable interference detection function that can accurately detect that a disturbing action has been performed when a disturbing object is stuck.

[0010]

In order to achieve the above object, a security sensor with an interference detection function according to a first configuration of the present invention has a main body having an infrared detecting element and a pressing force applied to the main body. A light-entering side surrounding member, which is sometimes displaceably mounted and includes a lens for setting a detection area of the infrared detection element or a cover for covering an incident surface side of the infrared detection element, and a projection for transmitting and receiving a light beam for interference detection. A light-emitting / light-receiving unit having an optical element and a light-receiving element, detecting a change in the amount of light received by the light-receiving element due to displacement of the light-incident-side outer member, and a detection circuit for detecting an obstructive action based on the detection. I have.
According to the above configuration, the light incident side outer surrounding member is displaced by the pressing force when the obstruction is attached to the outer surface thereof. The displacement of the light-incident-side outer member is detected by the light-emitting / receiving unit, and the detection circuit detects that the obstruction has occurred by this detection. Therefore, it is possible to reliably detect the obstruction regardless of the type of the obstruction attached to the outer surface of the light-incident-side surrounding member. In addition, since a light emitting and receiving unit is used instead of a mechanical switch, a large space is not required.

According to a second aspect of the present invention, there is provided a security sensor with an interference detection function, comprising: a main body having an infrared detecting element; a lens or an infrared detecting element mounted on the main body for setting a detection area of the infrared detecting element. Includes a light-incident-side outer member composed of a cover that covers the incident surface side, a light-emitting element and a light-receiving element that project and receive interference detection light rays, and receives light due to deformation of the light-entering-side outer member that receives a pressing force. The system includes a light emitting / receiving unit for detecting a change in the amount of light received by the element, and a detection circuit for detecting an obstructive action based on the detection. According to the above configuration, when the light-incident-side outer member is deformed by the pressing force at the time of sticking the obstruction to its outer surface, this deformation is detected by the light emitting and receiving unit, and the detection circuit detects the obstruction by the detection. Is detected. Therefore, it is possible to detect the obstruction regardless of the type of the obstruction attached to the outer surface of the light-incident-side outer member. In addition, since a light emitting and receiving unit is used instead of a mechanical switch, a large space is not required.

In a preferred embodiment of the first configuration, the light emitting and receiving unit is configured such that when the light incident side outer member is displaced, a part of the light incident side outer member transmits or blocks an interference detection light beam. The light receiving amount is set to change. According to this embodiment, when the light-incident-side outer member is displaced, a part of the light-incident-side outer member allows or blocks the interference detection light beam to change the amount of received light. The detection circuit detects that a sabotage has occurred when the amount of received light changes.

In a preferred embodiment of the second configuration, a light shielding member is provided on the light incident side outer member, and the light emitting and receiving unit detects interference with the light shielding member when the light incident side outer member is deformed. The light beam is set so that the amount of received light is changed by passing or blocking the light beam. According to this embodiment, when the light incident side outer member is deformed, the light beam for interference detection is passed or blocked by the light blocking member, and the amount of received light changes. The detection circuit detects that a sabotage has occurred when the amount of received light changes.

In a preferred embodiment of the first and second configurations, the light emitting and receiving unit emits an interference detection light beam toward an inner surface of the light incident side outer surrounding member, and emits a light beam from the inner surface. The reflected light is received, and the amount of received light is set to change when the light incident side outer member is displaced or deformed. According to this embodiment, when the light incident side surrounding member is displaced or deformed, the amount of reflected light received changes. The detection circuit detects that a sabotage has occurred when the amount of received light changes.

In the preferred embodiment of the second configuration, the light emitting / receiving unit is configured to transmit the interference detection light beam from a light emitting element facing one side of the light incident side outer member to the light incident side outer member. The incident light enters the light receiving element located on the other side through the inside of the light receiving element, and the amount of light of the interference detection light beam that has passed through the inside of the light incident side surrounding member changes due to the deformation of the light incident side surrounding member. Is set to According to this embodiment, when the light incident side surrounding member is deformed, the amount of received light changes. The detection circuit detects that a sabotage has occurred when the amount of received light changes.

In the preferred embodiments of the first and second configurations, the light emitting and receiving unit is also used as a light emitting and receiving unit for detecting an obstacle attached to the light incident side outer surrounding member. According to this embodiment, the light emitting and receiving unit includes a first optical path for detecting an obstacle attached to the outer surface of the light incident side outer member, and a displacement or deformation of the light incident side outer member. A second optical path, and the detecting circuit detects that an obstacle is attached or obstructed when the amount of light received in the first or second optical path changes.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view of the security sensor according to the first embodiment of the present invention. The security sensor 1 includes a passive far-infrared detecting element inside a main body A including a base 2 attached to a ceiling or a wall of a room, and a case 3 attached to the base 2 and covering the front surface of the base 2. A certain pyroelectric element 4 is housed. The case 3 is fixed to the base 2 so that it can be opened and closed by screwing (not shown).

FIG. 2 is a longitudinal sectional view of the security sensor 1 taken along the line II-II in FIG. As shown in FIG. 2, a lens 3, which is a light-incident-side outer member, is fitted in the case 3.
The lens 5 also serves as a protective cover for protecting the pyroelectric element 4 and is formed of a synthetic resin such as polyethylene that transmits far infrared rays.
A Fresnel lens portion 6 for setting a plurality of detection areas B is formed. Further, the light projecting side light guide member 8 and the light receiving side light guide member 9 are provided near the lens in the case 3 so as to slightly cover the upper and lower end portions of the lens 5 at the center of the lens 5 in FIG. Are mounted facing each other. The two light guide members 8 and 9 are located outside the detection area B, that is, in a region outside a region where far infrared rays enter the pyroelectric element 4 in FIG. 2.

On the wiring board 10 attached to the base 2 inside the main body A, the pyroelectric element 4, a light emitting element 11 for generating near-infrared light which is a light beam for interference detection, and a light beam for interference detection A light receiving element 12 for receiving L is mounted. Some of the near infrared rays emitted from the light projecting element 11 pass through the light projecting element 11 → the light projecting side light guide member 8 → outside the outer surface of the lens 5 → the light receiving side light guide member 9 → the light receiving element 12. First
An optical path L1 is formed, and the remaining part is a light emitting element 11 → a through hole 3e formed in a partition 3d inside the case 3 → a reflecting mirror M supported by the wiring board 10 or the case 3 → a light receiving element 1
2 to form a second optical path L2. The pyroelectric element 4, the light projecting element 11 and the light receiving element 12 are
And is covered with the case 3 and the lens 5 and is housed inside the main body A. The pyroelectric element 4 detects intrusion of a human body into the detection area B by detecting far infrared rays emitted from the human body in the detection area B via the lens 5.

The light emitting side light guide member 8 and the light receiving side light guide member 9
Transmits the interference detection light beam L from the light projecting element 11 to the light receiving element 1
2, and a part of the first optical path L <b> 1 is along the outer surface of the lens 5. The light exiting surface (one of the light transmitting surfaces) 8c of the light projecting side light guiding member 8 and the incident surface (one of the light transmitting surfaces) 9a exposed to the outside of the light receiving side light guiding member 9 opposed thereto. Has a ground glass-like minute uneven surface.

FIG. 3 is a cross-sectional view taken along the line III-III of FIG. In the figure, a lens 5 is supported by a case 3 so as to be displaceable inward and outward of the case 3, that is, in the first embodiment, in a direction perpendicular to the bottom surface of the base 2 (vertical direction in FIG. 3). That is, the locking claws 3b formed on the inner surfaces of the left and right side walls 3a of the case 3 are fitted into the through holes 5b formed on the left and right side walls 5a of the lens 5, and the lens 5 is moved inside and outside the case 3. It is set to be movable in a predetermined range in the direction. Further, an engagement portion 5c is formed at a lower end portion of the left and right side walls 5a of the lens 5, and this engagement portion 5c is formed.
A coil-shaped spring 20, which is an example of an elastic member, is inserted between the c and the protective wall 3 c of the case 3 in a compressed state by being fitted into a spring holding pin 21 provided on the protective wall 3 c of the case 3. The lens 5 is pushed out of the case 3 in the direction of arrow C, and is held in a state of being locked by the locking claw 3b. In this way, the locking claw 3b, the through hole 5b, the engaging portion 5c, and the coiled spring 20 support the lens 5 so as to be displaceable in the direction of arrow D. The protective wall 3c covers the periphery of the detection surface, which is the front surface of the pyroelectric element 4, and suppresses disturbance light from entering the pyroelectric element 4.

On the other hand, the through hole 3e is formed on the center line of the partition 3d in FIG. The through hole 3e is partially covered with the lower end 5e of the end wall 5d on the upper side (right side in FIG. 3) of the lens 5, and the end wall is displaced as the lens 5 is displaced in the direction of arrow D. The light blocking element 5 d is closed, and the light amount of the interference detection light beam L incident on the light receiving element 12 is reduced.

The light projecting element 11 is driven by the drive circuit 13 shown in FIG. A part of the interference detection light beam L of the first optical path L1 that enters the light-emitting side light guide member 8 from the incident surface (one of the light-transmitting surfaces) 8a of the light-projection side light guide member 8 is partially outside. After being reflected by the reflecting surface 8b exposed to the other side (the other part transmits through the reflecting surface 8b), or directly reaches the emitting surface 8c without reflection, and becomes scattered light from the emitting surface 8c as shown by a broken line. And a part of the light enters the incident surface 9a of the light receiving side light guide member 9 through the first optical path L1. The light beam incident on the incident surface 9a is scattered, and a part of the light is reflected by an outwardly exposed reflecting surface (part of the outer surface) 9b formed by an inclined surface opposed to the incident surface 9a, and is emitted by the emitting surface (light beam). The light exits from one of the transmission surfaces 9c and is received by the light receiving element 12. On the other hand, the light beam L for interference detection in the second optical path L2 toward the through hole 3e is reflected by the reflecting mirror M and
2 is received. The sum of the amount of incident light from the first optical path L1 and the amount of incident light from the second optical path L2 is the reference amount of incident light, which is the amount of light in a state where there is no sabotage. As a result, as shown in FIG. 5A, the output voltage V of the light reception amount detection circuit 14 becomes a low level, substantially constant reference value V0.

The security sensor 1 according to the first embodiment has a structure shown in FIG.
In this case, it is possible to detect an obstruction such as a transparent paint sprayed on the outer surface of the lens 5 and an obstructive act of attaching an obstruction such as a transparent tape to the outer surface of the lens 5. Hereinafter, first, a detection operation when an obstruction such as the transparent paint is spray-applied to the outer surface of the lens 5 will be described.

When the transparent paint is spray-coated on the outer surface of the lens 5, the transparent paint is applied to the light exit surface 8 c of the light projecting side light guide member 8.
And the incident surface 9a of the light receiving side light guide member 9, and the unevenness is filled to form a smooth surface. The light amount of the interference detection light beam L incident on the incident surface 9a of the side light guide member 9 increases, the scattering on the incident surface 9a decreases, and the light amount of the first optical path L1 incident on the light receiving element 12 increases. On the other hand, the amount of incident light on the second optical path L2 does not change. As a result, as shown in FIG. 5A, the output voltage V of the light reception amount detection circuit 14 for detecting the light reception amount of the light receiving element 12 is the first voltage.
It increases to V1 at a level higher than V0 by an increase in the amount of incident light on the optical path L1.

The outer surface of the lens 5 is coated with an obstruction such as black paint that blocks far-infrared rays, near-infrared rays, and visible light, and the reflecting surface (part of the outer surface) 8 of the light-emitting-side light guide member 8.
b or the light exit surface 8c, the light L for interference detection is absorbed by the obstruction, so that the light amount of the light L for interference detection emitted from the light exit surface 8c of the light projecting side light guide member 8 Decreases, and the first light incident on the light receiving element 12 is accordingly
The amount of light in the optical path L1 decreases. Further, even when black paint adheres to any one of the incident surface 9a and the reflecting surface 9b of the light receiving side light guide member 9, the interference detection light beam L incident on the light receiving element 12 via the light receiving side light guide member 9 is also provided. Of the light decreases.
On the other hand, the amount of incident light on the second optical path L2 does not change. As a result, the light receiving amount detecting circuit 1 for detecting the light receiving amount of the light receiving element 12
As shown in FIG. 5B, the output voltage V of No. 4 has a level V2 lower than V0 by the amount of decrease in the amount of incident light on the first optical path L1.

Next, when an obstruction such as a transparent tape or a black seal is adhered to the outer surface of the lens 5, the coil spring 20 shown in FIG. 4, the entire lens 5 is displaced in the direction of arrow D (inward), and the through hole 3e is closed by the end wall 5d as shown by a broken line in FIG.
2, the light amount of the interference detection light beam L in the second optical path L2 that is incident on the second light path L2 decreases. For this reason, the output voltage V
As shown in FIG. 5C, during the sticking operation, the amount of incident light on the second optical path L2 decreases to almost 0, and the output voltage V becomes a value V3 lower than V0 accordingly. When the pasting operation is completed, the level returns to the original level V0.

The detection circuit 15 shown in FIG. 4 has first and second comparators 16 and 17 and an alarm circuit 18.
The output voltage V of the received light amount detection circuit 14 is input to the comparator 16 and the second comparator 17. First comparator 1
6, the second comparator 1 compares the first threshold value d1 with the second threshold value d1.
At 7, comparison is made with the second threshold value d2. The first threshold value d1 is, for example, about 1.1 times the low level voltage V0 at the time of the reference incident light amount, and the second threshold value d2 is about 0.9 times the low level voltage V0. The output voltages V1, V2, and V3 are set to V1> d1, V2 <
d2 and V3 <d2 are set.

When the first comparator 16 satisfies V> d1, or when the second comparator 17 satisfies V <d2 or V3 <
At d2, a disturbance detection signal is sent to the alarm circuit 18, and the alarm circuit 18 sends an alarm signal to a control room (not shown). Thus, it is possible to detect an obstruction such as a transparent paint or a black paint applied to the outer surface of the lens 5 and detect an action of attaching the obstruction to the outer surface of the lens 5. The driving circuit 13 and the light receiving amount detecting circuit 1
4 and the detection circuit 15 are mounted on the wiring board 10.

Further, since the light beam L for detecting the interference of the first optical path L1 guided by the light projecting side light guiding member 8 and the light receiving side light guiding member 9 enters the light receiving element 12, the light projecting element 11 and the light receiving element 12 can be freely set to an appropriate position away from the lens 5, and in the first embodiment,
It is arranged on a wiring board 10 that can be easily supported. further,
Since a mechanical switch is not used, a large space around the lens 5 is not required.

As the obstacles, in addition to the transparent paint,
When an adhesive tape such as a transparent cellophane tape, a gel-like or cream-like adhesive or sealant, or the like is used, the reflection surface 8b or the reflection surface 8b of the light-emitting-side light guide member 8 is also used due to the adhesive or its own adhesiveness. Since the unevenness of the exit surface 8c or the entrance surface 9a or the reflection surface 9b of the light receiving side light guide member 9 is filled, the amount of light received by the light receiving element 12 changes, and an obstacle can be detected by detecting the amount of change. further,
Even if it is a liquid such as water or oil, the reflection surface, the outgoing surface or the ingoing surface becomes smooth until it is dried,
Since the amount of light received by the light receiving element 12 changes, the detection circuit 15 detects an obstacle.

In the first embodiment, the surface on which the unevenness is formed is a reflection surface (part of the outer surface) 8b or an emission surface 8c exposed to the outside of the light projecting side light guide member 8, and a light receiving side guide. Incident surface 9a and reflective surface 9 exposed outside optical member 9
Any one or a plurality of surfaces of b or a part of each surface may be used. Further, the light emitting side light guide member 8
Alternatively, the light-receiving-side light guide member 9 may be arranged so that a part of the light-receiving-side light guide member 9 enters a region where the near-infrared light enters the pyroelectric element 4.

FIG. 6A is an enlarged vertical sectional view showing a modification of the first embodiment. The same reference numerals as those in FIG. 2 denote the same or corresponding parts. This modification is different from the case of FIG. 2 in that the second optical path L2 is closed by the end wall 5d of the lens 5 in a normal state, and the lens 5 is displaced in the direction of arrow D at the time of sticking an obstacle. As shown in FIG.
The through-hole 5f formed in the end wall 5d overlaps the through-hole 3e of the partition 3d of the case 3 so that the light beam L for interference detection enters the light receiving element 12.

In this modification, the light reception amount detection circuit 1
As shown in FIG. 6 (c), the output voltage V of the first comparator 16 becomes a high level V4 during the obstruction sticking operation, and the first comparator 16 sends an interference detection signal to the alarm circuit 18 and the alarm circuit 18 Reference numeral 18 sends an alarm signal to a control room (not shown). After the action period, the reference value V01 (normally V01
Return to <V0).

As described above, in the security sensor according to the first embodiment, one set of light emitting and receiving units is provided with a first optical path for detecting an obstruction adhering to the outer surface of the light incident side outer member. The light emitting and receiving unit that forms the second light path for detecting the act of attaching an obstruction to the outer surface of the light incident side surrounding member is also used as the light emitting and receiving unit that forms the light emitting and receiving unit. Become.

FIG. 7 is a longitudinal sectional view showing a second embodiment of the present invention. In the figure, the same reference numerals as those in FIG. 2 indicate the same or corresponding parts. In the second embodiment,
On the inner surface of the lens 5 fixedly supported by the case 3, there is provided a plate-shaped light shielding member 30 having one end fixed to the lens 5 and extending in a direction substantially perpendicular to the wiring board 10 and the base 2. The lens 5 is made of a soft synthetic resin having flexibility as in the first embodiment. Wiring board 10
, A light projecting element 11 and a light receiving element 12 are mounted at positions sandwiching the light shielding member 30. The light shielding member 30
Means that the light emitting element 11 is normally used when no sabotage is performed.
7 and the position shown in FIG. 8A which does not prevent the interference detection light beam L emitted from the light receiving element 12 from being incident on the light receiving element 12.

When an obstruction such as a transparent tape is adhered to the outer surface of the lens 5, the lens 5 is moved inward (in the direction of arrow D) as shown by a broken line in FIG. 8), the tip of the light shielding member 30 moves in the direction of the arrow d in FIG. 8A with this deformation, and as shown in the broken line in FIG. 7 and FIG. It moves between the elements 12 and blocks light to reduce the amount of light incident on the light receiving element 12, and returns to the original position of FIG.

The output voltage V of the light reception amount detection circuit 14 shown in FIG.
As shown in FIG. 8C, the output voltage V02 in the normal state during the sticking period of the obstacle is caused by the movement of the light shielding member 30.
7 is lower, the comparator 19 in FIG. 7 sends a disturbance detection signal to the alarm circuit 18 when V <d2, and an alarm signal is sent from the alarm circuit 18 to detect a disturbance action.

Contrary to the second embodiment, the light shielding member 30 is normally positioned between the light projecting element 11 and the light receiving element 12 to shield the light L for interference detection during normal operation. The light shielding member 30 may be retracted from the light shielding position in accordance with the deformation described above to increase the amount of light received by the light receiving element 12.

FIG. 9 is a cross sectional view showing a third embodiment of the present invention. 3, the same reference numerals as those in FIG. 3 denote the same or corresponding parts. In the third embodiment,
Lens 5 made of flexible soft synthetic resin
Is fixedly supported on the case 3, and the interference detection light beam L emitted from the light projecting element 11 disposed on one side of the wiring board 10 sandwiching the pyroelectric element 4 is substantially centered on the inner surface of the lens 5. The light is emitted toward the light source, and the reflected light is received by a light receiving element 12 disposed on the other side of the wiring board 10. The detection circuit is the same as the detection circuit 15 of the second embodiment shown in FIG.

In the third embodiment, at the time of sticking an obstruction, the pressing force deforms the lens 5 in the direction of the arrow D as indicated by the broken line, and the reflection position of the obstruction detection light beam L accompanying this deformation. Is changed, and the optical path of the reflected light shifts as shown by the broken line, so that the amount of light incident on the light receiving element 12 decreases. As a result, the output voltage V of the received light amount detection circuit 14 in FIG. 4 changes in the same manner as in FIG. 8C in the second embodiment, and decreases during the period of the obstruction sticking operation. As in the embodiment, the comparator 19 determines that V <d
By sending an interference detection signal when the number becomes 3, it is possible to detect an action of attaching an obstacle. Also, lens 5
When a black paint is applied, V <d3 is also satisfied, so that the paint adhesion can be detected.

FIG. 10 is a cross-sectional view showing a third embodiment of the present invention, and the same reference numerals as those in FIG. 3 denote the same or corresponding parts. The lens 5 of the third embodiment is supported by the case 3 so as to be vertically displaceable, and is normally held at the position indicated by the solid line by the elastic force of the coil-shaped spring 20. The light projecting element 11 and the light receiving element 12 are arranged on one side of the left and right sides of the pyroelectric element 4 of the wiring board 10, similarly to the third embodiment shown in FIG. Element 1
1, the interference detection light beam L is emitted toward substantially the center of the inner surface of the lens 5, and the reflected light is received by a light receiving element 12 provided on the other side of the wiring board 10.

In the third embodiment, at the time of sticking an obstruction, the lens 5 is displaced in the direction of arrow D as shown by the broken line due to the pressing force, and the reflection position of the obstruction detection light beam L is accompanied by this displacement. Is changed, and the optical path of the reflected light shifts as shown by the broken line, so that the amount of light incident on the light receiving element 12 decreases. The detection circuit 15 is the same as that shown in FIG. 7, and the output voltage V of the received light amount detection circuit 14 is
As shown in (c), the level changes during the obstruction sticking action period, and returns to the original level V0 after the obstruction sticking action period.
By transmitting an interference detection signal when V <d3, it is possible to detect an action of attaching an obstacle. When a black paint is applied to the lens 5, V <
Since it is d3, this paint adhesion can be detected.

FIG. 11 is a cross-sectional view showing a modification of the third embodiment. The same reference numerals as those in FIG. 3 denote the same or corresponding parts. In this modification, a locking claw 3b is formed on the inner surface of the left and right side walls 3a of the case 3, and the locking claw 3b is formed.
Is engaged with a plurality of locking recesses 5g formed on the outer surfaces of the left and right side walls 5a of the lens 5, and when the obstacle is attached, the pressing force between the locking claw 3b and the locking recess 5g is caused by the pressing force. The engagement is released, and the lens 5 is moved as indicated by an arrow D as shown by a broken line.
In the direction, and the reflection position of the interference detection light beam L changes with this displacement. In this modification, the lens 5 remains at the displaced position even after the obstruction sticking action is completed, so that the displacement of the lens 5 can be visually detected.

FIG. 12 is a cross-sectional view showing a security sensor according to a fourth embodiment of the present invention. In FIG.
The same reference numerals denote the same or corresponding parts.

The security sensor 1 shown in FIG.
A support having a base 2 attached to the ceiling surface S, a wiring board 10 provided on the base 2, and a pivotally adjustable support supported by a pair of support members 25, 25 mounted on the wiring board 10. A pyroelectric element 4 and a polygon mirror 2 are provided on a substrate 26.
7 are formed to form a plurality of detection areas B, and are made of opaque synthetic resin that covers the entire packaged product on the wiring substrate 10 including the incident surface side of the pyroelectric element 4 and the far-infrared ray to the polygon mirror 27. Hemispherical cover (a kind of outer member on the light incident side) 28
Is attached to the base 2. The light projecting side light guide member 8 and the light receiving side light guide member 9 are placed outside the portion where the detection area B of the cover 28 passes, that is, in a region outside the near infrared ray incident region to the pyroelectric element 4, and The surface 8c and the latter incident surface 9a are mounted so as to face each other. The cover 28 merely protects the sensor body A and does not have a lens function for setting a detection area. The wiring board 10 includes:
The light emitting element 11 and the light receiving element 12 are mounted. Thus, the pyroelectric element 4, the light emitting element 11, and the light receiving element 12
Are supported by the base 2 via the wiring board 10, covered by the cover 28, and housed inside the main body A. The light projecting element 11 is connected to the drive circuit 13 shown in FIG. 4, and the light receiving element 12 is connected to the light receiving amount detecting circuit 14 and the detecting circuit 15.

The first optical path L1 included in the interference detection light beam L emitted from the light projecting element 11 of the security sensor 1 is: light projecting element 11 → light projecting side light guide member 8 → outgoing surface 8c → incident surface 9
a → light receiving side light guide member 9 → light receiving element 12, and the second optical path L2 reaches light emitting element 11 → inner surface of cover 28 → light receiving element 12. The emission surface 8c formed on the ground glass-shaped uneven surface of the light projecting side light guide member 8 and the incident surface 9a formed on the ground glass-shaped uneven surface of the light receiving side light guide member 9 are:
When the transparent paint or the black paint is applied to the cover 28 and an obstruction adheres to the light exit surface 8c or the light incident surface 9a, it protrudes from the cover 28, as in the first embodiment. Since the amount of received light increases or decreases as compared with the case where there is no obstruction, the detection circuit 15 detects the obstruction.

On the other hand, if an obstructive action such as sticking an obstruction such as a transparent tape to the outer surface of the cover 28 is performed, the pressing force at the time of the sticking causes the lens 5 to move inward (as shown by a broken line in FIG. 12). (In the direction of arrow D), the reflection position of the second optical path L2 is displaced as shown by the broken line with this deformation, and the amount of light incident on the light receiving element 12 decreases. When the obstruction sticking operation is completed, the cover 28 returns to the original position.
At this time, the amount of light incident on the light receiving element 12 changes in the same manner as in the first embodiment, and the output voltage V of the light receiving amount detection circuit 14 in FIG. 4 also changes as shown in FIGS. The detection circuit 15 can perform the same processing as in the first embodiment and transmit an alarm signal.

FIG. 13 is a perspective view of a security sensor according to a fifth embodiment of the present invention. FIG. 14 is a cross-sectional view taken along the line XV-XV of FIG. Or the corresponding part is shown. In FIG. 13, the lens 5 is formed as a flat plate made of opaque soft synthetic resin.
Are held by support portions 3f and 3g formed on both sides of the front surface of the case 3. Further, the support portions 3f,
3g and a light-receiving element housing 3i formed adjacent to the light-receiving element housing 3i.
j, 3k are formed, and the interference detection light beam L emitted from the light projecting element 11 disposed in the light projecting element housing portion 3h passes through the through hole 3j → the lens 5 → the through hole 3k to receive the light receiving element. 12, and the output voltage V of the light reception amount detection circuit 14 in the normal state is
It is configured to be V02 shown in FIG.

In the security sensor of the fifth embodiment, when an act of attaching an obstruction such as a transparent tape to the outer surface of the lens 5 is performed, the lens 5 is moved in FIG. Inside as indicated by broken line (direction of arrow D)
A part of the interference detection light beam L incident on the lens 5 with this deformation is transmitted through the through hole 3k to the light receiving element 12 through the outer surface and the inner surface of the lens 5 to the outside.
The amount of light incident on the light source changes (in this case, decreases), and returns to the original light amount when the sabotage action ends. At this time, since the output voltage V of the received light amount detection circuit 14 changes as shown in FIG. 15, the first comparator 16 outputs a disturbance detection signal to the alarm circuit 18 when V <d4, and the alarm circuit 18 18 sends an alarm signal.

The lens 5 is not limited to a flat plate shape, that is, a flat shape. For example, the lens 5 may be curved so as to protrude outward. By deforming into a flat shape,
A change (for example, an increase) in the amount of light received by the light receiving element 12 is detected to detect a sabotage. The change in the amount of received light due to the deformation of the lens 5 can be appropriately set to increase or decrease depending on the setting of the optical path and the initial amount of received light.

[0052]

As described above, in the security sensor according to the first or second configuration of the present invention, when an obstacle is attached to the outer surface of the light-incident side surrounding member by an obstructing actor, the security sensor is attached. By detecting the displacement or deformation of the light incident side surrounding member due to the pressing force at the time of attaching action by the light emitting and receiving unit, it is configured to detect the obstructive act, so that the outer surface of the light incident side surrounding member is Interference can be reliably detected regardless of the type of obstruction to be pasted. Moreover, since the light emitting and receiving unit is used instead of a mechanical switch,
Does not require large space.

[Brief description of the drawings]

FIG. 1 is a perspective view of a security sensor with a disturbance detection function according to a first embodiment of the present invention.

FIG. 2 is a longitudinal sectional view taken along the line II-II of FIG.

FIG. 3 is a transverse sectional view taken along the line III-III of FIG. 2;

FIG. 4 is a diagram illustrating an operation of detecting an obstruction and an obstructive action according to the first embodiment.

FIG. 5 is a diagram illustrating an output voltage characteristic of the light reception amount detection circuit according to the first embodiment.

FIG. 6 is a diagram showing a modification of the first embodiment.

FIG. 7 is a longitudinal sectional view of a security sensor according to a second embodiment of the present invention.

FIG. 8 is a diagram illustrating the operation of the second embodiment and the output voltage characteristic of the received light amount detection circuit.

FIG. 9 is a cross-sectional view of a security sensor according to a third embodiment of the present invention.

FIG. 10 is a cross-sectional view of a security sensor according to a third embodiment of the present invention.

FIG. 11 is a diagram showing a modification of the third embodiment.

FIG. 12 is a cross-sectional view of a security sensor according to a fourth embodiment of the present invention.

FIG. 13 is a perspective view of a security sensor according to a fifth embodiment of the present invention.

FIG. 14 is a longitudinal sectional view taken along line XV-XV of FIG.

FIG. 15 is a diagram illustrating the operation of the fifth embodiment and the output voltage characteristics of the light reception amount detection circuit.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Security sensor, 2 ... Base, 3 ... Case, 3a ... Side wall (left and right of case), 3b ... Locking claw, 3c ... Protective wall, 3
d: partition wall (inside the case), 3e: through-hole, 3f, 3g
.., Lens support portions, 3j, 3k, through holes, 3h, light projecting element housing portions, 3i, light receiving element housing portions, 4 ... pyroelectric elements (infrared ray detecting elements), 5 ... lenses (light-incident side outer surrounding members), 5a ... side wall (left and right of lens), 5b ... through hole, 5c ... engaging part, 5d
... end wall (upper side of lens), 5e ... lower end of side wall, 5f
... through-hole, 5g ... locking concave part, 6 ... Fresnel lens part, 7 ...
Projection, 8: Projecting light guide member, 8a: Incident surface, 8b: Reflecting surface, 8c: Outgoing surface, 9: Light receiving light guide member, 9a: Incident surface, 9b: Reflecting surface, 9c: Outgoing surface, 10 ... Wiring board, 1
DESCRIPTION OF SYMBOLS 1 ... Light emitting element, 12 ... Light receiving element, 13 ... Drive circuit, 14
... Received light amount detection circuit, 15 ... Detection circuit, 16 ... First comparator, 17 ... Second comparator, 18 ... Alarm circuit, 19 ... Comparator, 20 ... Coiled spring, 21 ... Holding pin, 25 ... Support Member, 26: support substrate, 27: polyhedral mirror, 28: cover (light-incident side outer surrounding member), 30: light shielding member, 31: obstruction (transparent tape), A: body, B: detection area, M ... Reflecting mirror, L: light beam for interference detection, L1: first optical path, L2: second optical path.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5C084 AA02 AA07 AA08 AA13 BB33 CC16 CC19 DD43 DD58 DD62 DD65 DD77 DD87 EE01 GG07 GG09 GG55 GG56 GG57

Claims (7)

[Claims] A main body having an infrared detecting element; a lens which is displaceably mounted on the main body when receiving a pressing force to set a detection area of the infrared detecting element; A light incident side surrounding member comprising a cover for covering the light receiving element, a light projecting element and a light receiving element for projecting and receiving a light beam for interference detection, and detecting a change in a light receiving amount of the light receiving element due to a displacement of the light entering side surrounding member. A security sensor with an interference detection function, comprising: a light emitting / receiving unit that performs the detection and a detection circuit that detects an interference act based on the detection. 2. A light-entering side surrounding member comprising a main body having an infrared detecting element, and a lens mounted on the main body and setting a detection area of the infrared detecting element or a cover covering an incident surface side of the infrared detecting element. A light emitting and receiving unit having a light emitting element and a light receiving element for projecting and receiving a light beam for interference detection, and detecting a change in the amount of light received by the light receiving element due to deformation of the light incident side outer member that has received the pressing force; A security sensor with a disturbance detection function, comprising: a detection circuit for detecting a disturbance action based on this detection. 3. The light emitting and receiving unit according to claim 1, wherein when the light incident side outer member is displaced, a part of the light incident side outer member passes or blocks the interference detection light beam and the light receiving amount is reduced. Security sensor with interference detection function set to change. 4. The light-receiving-side outer member according to claim 2, wherein a light-shielding member is provided on the light-entering-side outer member, and when the light-entering-side outer member is deformed, the light-shielding member generates a light beam for obstruction detection. A security sensor with an interference detection function set so that the amount of received light is changed by passing or blocking. 5. The light emitting and receiving unit according to claim 1, wherein the light emitting and receiving unit emits an interference detection light beam toward an inner surface of the light incident side outer surrounding member and receives reflected light from the inner surface. A security sensor with an interference detection function set so that the amount of received light changes when the light incident side outer member is displaced or deformed. 6. The light projecting and receiving unit according to claim 2, wherein the light beam for detecting interference passes from the light projecting element facing one side of the light incident side surrounding member to the inside of the light incident side surrounding member. The incident light is incident on the light receiving element located on the other side, and the light receiving amount of the interference detection light beam that has passed through the inside of the light incident side outer member due to the deformation of the light incident side outer member is set to change. Security sensor with interference detection function. 7. The light emitting and receiving unit according to claim 1, 2 or 4, wherein the light emitting and receiving unit is also used as a light emitting and receiving unit for detecting an obstacle attached to the light incident side surrounding member. Security sensor.