JPH08271644A - Infrared detection apparatus - Google Patents

Abstract

PURPOSE: To provide an infrared detection apparatus by which a wasteful power consumption is suppressed. CONSTITUTION: When an infrared sensor 1 receives infrared rays from a human body, pulses P are output by a comparison circuit 3. Thereby, a triggerable time circuit 6 is triggered, and an output 'H' is issued. A sensor rocking device 5 which has received the output starts an operation, and the infrared sensor 1 is rocked so as to move its detection range B. When the detection range B is moved, pulses P are generated whenever the human body enters the detection range B, the output of the triggerable timer circuit 6 is held, and the operation of the sensor rocking device 6 is continued. When a prescribed time elapses after the human body has not been detected, the triggerable timer circuit 6 issues an output 'L', and the operation of the sensor rocking device 5 is stopped. As a result, the power consumption of the sensor rocking device 5 can be suppressed when an object to be detected such as the human body or the like does not exist.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an infrared detector.

[0002]

2. Description of the Related Art Conventionally, an infrared detecting device using a differential output type infrared sensor such as a pyroelectric type uses a chopper 31 as shown in FIG. By making the infrared sensor 32
A configuration has been adopted in which an output is generated by measuring the difference between the temperature within the detection range and the chopper temperature, and the presence of a detection target such as a human body in a stationary state is detected. In the figure, 33 is a chopper driving device, and 34 is an amplifier circuit for amplifying the output of the infrared sensor 32. Reference numeral 35 denotes a comparison circuit, which compares the reference signal output from the reference signal generation circuit 36 with the amplified output of the infrared sensor 1, and generates an output when the amplified output of the infrared sensor 32 becomes larger. 37 is a case where these are stored.

Further, as shown in FIG. 3b, there is also a structure in which the infrared sensor 32 itself is swung by a sensor swinging device 38 within a certain angle range to detect a human body in a stationary state. In the figure, the same reference numerals as those in FIG. 3A indicate the same elements.

[0004]

As described above, in order to continuously detect the presence of a stationary human body, it is necessary to use a chopper or move the detection range. However, the human body is the detection range or its moving range. If the infrared rays from the detection target are not detected further away, these operations become unnecessary.
However, in the above-described one, the chopper drive device 33 and the sensor rocking device 3 are irrespective of the presence or absence of the detection target.
Since 8 was always operated, useless power was consumed when the detection target was absent.

Therefore, an object of the present invention is to provide an infrared detection device which suppresses unnecessary power consumption.

[0006]

An infrared sensor for detecting infrared rays emitted from a detection target and the infrared sensor by moving the detection range of the infrared sensor or interrupting the infrared ray incident on the infrared sensor intermittently. Control means for controlling the incidence of infrared rays on the infrared ray sensor, and start the operation of the control means when a desired infrared ray is detected by the infrared sensor, and the control is performed when the output from the infrared sensor is interrupted for a predetermined time or more. The above-mentioned object is achieved by an infrared detecting device having an operation control means for stopping the operation of the means.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an infrared detecting device according to an embodiment of the present invention will be described. FIG. 1A is an explanatory diagram showing the configuration of this example. Reference numeral 1 denotes an infrared sensor, and in this example, a differential output type pyroelectric infrared sensor is used. Reference numeral 2 is an amplifier circuit, which amplifies the output of the infrared sensor 1. Reference numeral 3 is a comparison circuit, which compares the reference signal output from the reference signal generation circuit 4 with the output of the infrared sensor 1 amplified by the amplification circuit 2. The signal output by the reference signal generation circuit 4 is a voltage slightly lower than the signal level amplified by the amplification circuit 2 when the infrared sensor 1 detects infrared rays generated by the human body. Reference numeral 5 denotes a sensor oscillating device as a control means, which oscillates the infrared sensor 1 itself within a certain angle range (for example, indicated by an arrow A in FIG. 1) to detect the detection range of the infrared sensor 1 (for example, FIG. 1). (Indicated by B in FIG. 2) to control the incidence of infrared rays on the infrared sensor 1 so that a human body in a stationary state can be detected. Reference numeral 6 denotes a retriggerable timer circuit, which holds an output for a predetermined time when triggered by the output of the comparison circuit 3, and holds an output for a further predetermined time from this timing when newly triggered within the predetermined time. While the output from the retriggerable timer circuit 6 is generated, the sensor swinging device 5 operates.
The amplifier circuit 2, the comparison circuit 3, the reference signal generation circuit 4, and the retriggerable timer circuit 6 constitute operation control means. Reference numeral 7 denotes a home position detecting device, which detects the home position of the infrared sensor 1 and outputs it to the sensor rocking device 5. Here, this home position is determined by the directivity of the infrared detection device. For example, here, the detection range B is a position as shown by the solid line in FIG. 1, but according to the desired directivity. It can be changed. That is, when the home position detecting device 7 stops the operation of the sensor rocking device 5, the home position detecting device 7 stops the operation of the sensor rocking device 5 in synchronization with the output of the home position detecting device 7. 1 is for stopping the home position at the home position, whereby the directivity of the infrared detecting device when the operation of the sensor rocking device 5 is stopped is guaranteed. Here, although the configuration of the home position detection device 7 is not particularly illustrated and described, for example, it is assumed that a reflection plate and a reflection type photo sensor are used similarly to the configuration generally used for current position detection of a rotating body. . Further, 8 is a case in which the above configuration is accommodated.

Next, the operation of this example will be described with reference to FIG. C shown in b of the same figure shows the signal at the terminal C of the same figure, that is, the output of the comparison circuit 3, and D shows the signal of the terminal D, that is, the output of the retriggerable timer circuit 6.

First, when the human body enters the detection range B, the infrared sensor 1 produces a differential output, and the comparison circuit 3 produces a pulse P as a detection output. The retriggerable timer circuit 6 is triggered by this pulse P to generate an output "H". When the terminal D becomes "H", the sensor oscillating device 5 starts its operation, and the sensor 1 is oscillated and the detection range B is moved as shown by the broken line in FIG. Each time a human body enters such a moving detection range B, the infrared sensor 1 produces a differential output, and a pulse P is generated at the same time. This allows
The retriggerable timer circuit 6 is repeatedly triggered and the terminal D is held at "H".

Here, if the infrared ray from the human body cannot be detected even if the human body moves away from the infrared detecting device of this embodiment and the detection range B is moved, the generation of the pulse P is stopped and the retriggerable timer circuit. 6 stops its output after a lapse of a predetermined time from the last trigger, and the terminal D becomes "L". As a result, the operation of the sensor oscillating device 5 is stopped after a lapse of time T after the pulse P is cut off. At this time, the operation of the sensor oscillating device 5 is stopped together with the output of the home position detecting device 7, so that the infrared sensor 1 is stopped at the home position where the detection range B is as shown by the solid line in FIG. This ensures the directivity of the infrared detection device when the sensor rocking device 5 is stopped.

As described above, in this example, if it can be considered that the detection target such as a human body does not exist, the sensor rocking device 5 is stopped, so that useless power consumption can be suppressed.

In the above embodiment, the infrared detecting device of the type in which the detection range is moved was described, but the present invention is not limited to this, and for example, as shown in FIG. It can also be used in an infrared detector of the type that intermittently blocks the incidence of infrared rays. In the figure, the same numbers as in FIG. 1 indicate the same items. Reference numeral 21 is a chopper, which intermittently blocks the infrared ray from entering the infrared sensor 1. A chopper drive circuit 22 drives the chopper 21 while the output of the retriggerable timer circuit 6 is "H". Reference numeral 23 denotes a home position detecting device, which detects the home position of the chopper 21, and specifically, as shown in b of the figure, a reflection plate 24 provided on the chopper 21 is reflected by a reflection type photo sensor 25. By detecting, the home position where the opening 26 of the chopper 21 overlaps the light receiving surface of the infrared sensor 1 is detected. 27 to 29 are other openings, and 30 is a rotating shaft of the chopper 21. That is, when the home position detection device 23 stops the operation of the chopper drive device 22, the home position detection device 23 stops the operation of the chopper drive device 22 in synchronization with the output of the home position detection device 23 so that the home position of the chopper 21 is adjusted. The infrared sensor 1 can detect infrared rays from the detection target even when the operation of the chopper drive device 22 is stopped. The operation of the infrared detecting apparatus of FIG. 2 configured as described above will not be particularly described, but the present apparatus exhibits the same operation and effect as those of the above-described embodiment.

[0013]

According to the present invention, when a desired infrared ray is detected by the infrared sensor, the operation of the control means for controlling the incidence of the infrared ray on the infrared sensor is started,
Since the operation of the control means is stopped when the output from the infrared sensor is interrupted for a predetermined time or longer, the power consumption by the control means in the absence of the detection target can be suppressed. As a result, it becomes possible to provide an infrared detection device that suppresses unnecessary power consumption.

[Brief description of drawings]

FIG. 1 is an explanatory diagram for explaining an infrared detection device according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram for explaining an infrared detection device according to another embodiment of the present invention.

FIG. 3 is an explanatory diagram showing a configuration of a conventional technique.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 infrared sensor 2 amplification circuit (operation control means) 3 comparison circuit (operation control means) 4 reference signal generation circuit 5 sensor oscillating device (control means) 6 retriggerable timer circuit (operation control means) 21 chopper (control means) 22 Chopper drive circuit (control means)

Claims (1)

[Claims] 1. An infrared sensor for detecting infrared rays emitted from a detection target, and an infrared sensor for moving infrared rays to the infrared sensor by moving the detection range of the infrared sensor or intermittently blocking the incidence of infrared rays on the infrared sensor. Control means for controlling the incidence, start the operation of the control means when a desired infrared ray is detected by the infrared sensor, the operation of the control means when the output from the infrared sensor is interrupted for a predetermined time or more. An infrared detecting device comprising: an operation control unit for stopping the operation.