JP2000097768A - Passive infrared crime-preventing sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase the reliability of detection of an intruder. SOLUTION: This passive infrared crime-preventing sensor 1 contains infrared rays detection parts 6a, 6b, and optical system parts 2a, 2b for converging infrared rays from a plurality of detection regions Qa,...Qa, Qb,...Qb having a beam form to the infrared rays sense parts, and is provided with first and second identical passive infrared detection unit A, B in the vicinity, and optical system axes Pa, Pb of the first and second passive infrared detection units are arranged so as to intersect each other at a predetermined position, and also the optical system parts are rotated for the optical system axes and arranged so that the plurality of detection regions having a beam form at a position apart from the optical system axes of the first and second passive infrared detection units are dispersed without overlapping as much as possible.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a passive infrared security sensor for eliminating a dead zone by using a plurality of passive infrared detection units having a plurality of beam-shaped sensing areas.

[0002]

FIG. 6 is a side view showing the appearance of a conventional passive infrared security sensor, FIG. 7 is a side view showing the sensing area of the conventional passive infrared security sensor, and FIG. 8 is a conventional passive infrared security sensor. FIG. 3 is a plan view showing a sensing region of FIG.

[0003] The passive infrared security sensor 1 includes a lens 2 corresponding to an optical system as shown in FIG. The lens 2 protrudes from the window of the housing 3 to form a plurality of beam-shaped sensing areas Q,... Q, and the infrared rays coming from the sensing areas Q,. To an infrared sensor (not shown).

[0004]

However, in the conventional passive infrared security sensor 1 having a plurality of beam-shaped sensing areas Q, the sensing area Q is sparse as shown in FIG. 7 or FIG. Therefore, even if the passive infrared security sensor 1 is installed, there is a problem that an intruder can enter through a dead zone where the sensing area A does not exist, and the intruder may not be detected.

The present invention has been made to solve the above problems, and an object of the present invention is to provide an excellent passive infrared security sensor having a reduced dead zone and improved detection reliability of an intruder. It is in.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention is directed to the invention as set forth in claim 1, wherein an infrared sensing unit and a plurality of beam-shaped sensing areas are transmitted to the infrared sensing unit. And an optical system for converging infrared rays, and comprising the same first and second passive infrared detection units in the vicinity, wherein the first and second passive infrared sensors are provided. The optical axis of the detection unit is disposed so as to intersect at a desired position, and a plurality of beam-shaped sensing areas at positions away from the optical axis of the first and second passive infrared detection units are possible. The optical system is arranged so as to be rotated with respect to the optical system axis so as to be dispersed as little as possible.

[0007] According to the invention of claim 2, in the first aspect,
The first detection signal output from the passive infrared detection unit of the first embodiment and the second detection signal output from the second passive infrared detection unit
A logical operation means for detecting the logical signal and a logical sum operation or an AND operation of the logical operation means are provided, and a security alarm signal is output based on the output of the logical operation means. It is characterized by doing so.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a passive infrared security sensor according to the present invention will be described in detail with reference to FIGS.
FIG. 1 is a side view showing the appearance of the passive infrared security sensor, FIG. 2 is a plan view showing the sensing area of the passive infrared security sensor,
3 is a side view showing the relationship between the installation position of the passive infrared security sensor and the intruder, FIG. 4 is a main part circuit diagram showing the passive infrared security sensor, and FIG. 5 is a diagram showing the relationship between the intruder detection signal and the security alarm signal. 6 is a timing chart showing a relationship. Note that the same reference numerals are given to the same portions as those of the conventional passive infrared security sensor described with reference to FIGS. 6 to 8 in the related art.

The passive infrared security sensor 1 shown in FIG.
Are different from the conventional ones in that the infrared sensing unit, a lens corresponding to an optical system unit that converges infrared rays from a plurality of beam-shaped sensing areas to the infrared sensing unit, and an electrical If the output is equal to or higher than a predetermined threshold, a comparator circuit that outputs a detection signal is unitized, and a plurality of the unitized passive infrared detection units are incorporated in one housing, and the optical axis of each passive infrared detection unit is integrated. Are arranged so as to intersect at a desired point, and disperse the plurality of beam-shaped sensing areas at positions away from the optical system axis of each passive infrared detection unit as little as possible, so as to disperse them. The optical system section is disposed so as to be rotated with respect to the axis of the optical system, logical operation means for the detection signal from each passive infrared detection unit is provided, and the logical operation means is ORed. Logical product is a structure in which a one of alternative selection switch to operation or cause.

As shown in FIG. 1, a passive infrared security sensor 1 corresponds to a unit A corresponding to a first passive infrared detection unit and a second passive infrared detection unit in a housing 3. It comprises a unit B, a logic circuit 4 corresponding to a logic operation means, and a setting switch 5 corresponding to an alternative selection switch. Unit A and unit B are the same. The unit A includes a lens 2a corresponding to an optical system unit and a pyroelectric element 6a corresponding to an infrared sensing unit.
And a comparison circuit 7a. Unit B
Is configured to include a lens 2b corresponding to an optical system unit, a pyroelectric element 6b corresponding to an infrared sensing unit, and a comparison circuit 7b. Each of the lenses 2 a and 2 b protrudes outside from a window provided in the housing 3. The logic circuit 4 includes an OR operation unit and an AND operation unit.

The lens 2a has an optical system axis Pa, and a beam-shaped beam 4 with respect to the pyroelectric element 6a around the optical system axis Pa.
, Qa are formed. The lens 2b is
An optical system axis Pb is provided, and four beam-shaped sensing regions Qb,... Qb for the pyroelectric element 6b are formed around the optical system axis Pb. When the passive infrared security sensor 1 is installed on the ceiling, the lens 2a and the lens 2b
And the optical system axis Pb are arranged slightly inward so as to intersect at a point P on the floor surface, and if the respective sensing areas Qa,... Qa and the sensing areas Qb,. The lens 2a is disposed so as to be rotated about the optical system axis Pa and the lens 2b is rotated about the optical system axis Pb so as to be dispersed.

Therefore, in the passive infrared security sensor 1 shown in FIG. 1, as shown in FIG. 2, each angle θ of the sensing area Qa and the sensing area Qb with respect to one point P is 45 degrees.
It becomes degree. That is, the beam-shaped sensing area is the unit A
Whereas, if the unit B is sparse at 90 degrees, the unit B can be arranged at a high density at 45 degrees by arranging the unit B as described above, and the intruder M can pass through the dead zone as shown in FIG. Can be difficult to enter.

The logic circuit 4 includes a central processing unit 40 as shown in FIG. The central processing unit 40 performs a logical operation on the detection signal output from the comparison circuit 7a of the unit A and the detection signal output from the comparison circuit 7b of the unit B, and outputs a security alarm signal. The setting switch 5 is connected to the central processing unit 40. If the setting switch 5 is turned on, the central processing unit 40 performs a logical product (AND) operation, and the setting switch 5 Is set to off, a logical sum (OR) operation is performed.

In the passive infrared security sensor 1 as described above, a security alarm signal is output at the timing shown in FIG. That is, in cases where setting switch 5 is set to OFF, as shown at time t ₁ or time t _2, the detection signal of the intruder M from either the unit A and the unit B is output Then, the passive infrared security sensor 1 outputs a security alarm signal. Also,
When the setting switch 5 is set to the ON state after time t ₃ , for example, as shown at time t ₄ , both the unit A and the unit B receive the intruder M.
Is output, the passive infrared security sensor 1
Although outputs a security alarm signal, for example, as shown at time t ₅ or time t _6, than the detection signal of only intruder M from either the unit A and the unit B is output, the passive infrared The security sensor 1 does not output a security alarm signal.

Therefore, if the setting switch 5 is set to off, even if the animal is not the intruder M but a small animal such as a cat or a dog, any of the sensing areas Qa,... Qa and the sensing areas Qb,. If any one of the sensing areas passes, a security alarm signal can be output anyway, so that the risk of losing a report and overlooking the intruder M can be reduced. In addition, if the setting switch 5 is set to ON, a small animal such as a cat or a dog that does not pass through the sensing area Qa and the sensing area Qb at the same time does not output a security alarm signal. Since the security alarm signal can be output only when the intruder (human) M has actually entered, the trouble of false alarm can be eliminated. That is, in the passive infrared security sensor 1 as described above, the setting switch 5 can be switched and used depending on the time and the case, which is very convenient.

The present invention is not limited to the above-described embodiment, but may use a reflector or the like instead of a focusing lens of the optical system, and may use a reflector or the like. The pyroelectric element may be a thermistor element or the like.

[0017]

According to the first aspect of the present invention, a plurality of inexpensive infrared detecting units that generate a wide dead zone are combined so as to disperse as much as possible without overlapping beam-shaped sensing areas. The security sensor according to the first aspect of the invention can provide an excellent passive infrared security sensor that is inexpensive, has a reduced dead zone and increases the reliability of detecting an intruder.

According to the second aspect of the present invention, in addition to the effects of the first aspect of the present invention, it is possible to make settings so as to eliminate unreporting depending on the time and the case, and to make troublesome misinformation due to invasion of small animals or the like. Since the setting can be selected by eliminating the setting, it is possible to provide an excellent passive infrared security sensor that is extremely easy to use.

[Brief description of the drawings]

FIG. 1 is a side view showing the appearance of a passive infrared security sensor according to an embodiment of the present invention.

FIG. 2 is a plan view showing a sensing area of the passive infrared security sensor.

FIG. 3 is a side view showing a relationship between an installation position of the passive infrared security sensor and an intruder.

FIG. 4 is a main part circuit diagram showing the passive infrared security sensor.

FIG. 5 is a timing chart showing a relationship between an intruder detection signal of the passive infrared security sensor and a security alarm signal.

FIG. 6 is a side view showing the appearance of a conventional passive infrared security sensor.

FIG. 7 is a side view showing a sensing area of the passive infrared security sensor.

FIG. 8 is a plan view showing a sensing area of the passive infrared security sensor.

[Explanation of symbols]

Reference Signs List 1 passive infrared security sensor 2a optical system unit of first passive infrared detection unit 2b optical system unit of second passive infrared detection unit 4 logical operation means 5 alternative switch 6a infrared sensing unit 6b infrared sensing unit A First passive infrared detection unit B Second passive infrared detection unit Pa Optical axis of first passive infrared detection unit Pb Optical axis of second passive infrared detection unit Qa First passive infrared detection unit Sensing area of detection unit Qb Sensing area of second passive infrared detection unit

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2G065 AB02 BA12 BA13 BA14 BA32 BB01 BB44 BC01 BC13 BC14 BC16 BC22 BC35 BD06 DA20 5C084 AA02 AA07 BB05 BB40 CC19 DD44 DD57 GG37

Claims (2)

[Claims] 1. An infrared sensor comprising: an infrared sensor; and an optical system for converging infrared beams from a plurality of sensing areas in a beam shape to the infrared sensor. A passive infrared security sensor having a detection unit, wherein the first and second passive infrared detection units are disposed so that their optical system axes intersect at a desired position, and the first and second passive infrared detection sensors are provided. That the optical system is rotated with respect to the axis of the optical system so as to disperse the multiple beam-shaped sensing areas away from the optical system axis of the type infrared detection unit as little as possible. Features a passive infrared security sensor. 2. A logical operation means for calculating a first detection signal output from the first passive infrared detection unit and a second detection signal output from the second passive infrared detection unit, 2. A security alarm signal according to claim 1, further comprising a switch for selecting whether the logical operation means performs an OR operation or an AND operation, and outputting a security alarm signal based on an output of the logical operation means. Passive infrared security sensor.