JP2012112741A - Lighting fixture with doppler sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lighting fixture equipped with a Doppler sensor capable of suppressing power consumption.SOLUTION: A Doppler sensor 1 comprises an oscillator 3 for generating a transmission signal having a predetermined frequency, a plurality of transmission/reception circuits 4a and 4b for generating a Doppler signal by transmitting and receiving an electric wave for different detection ranges while the transmission signal is input and a switching circuit 7 for periodically switching the transmission/reception circuits 4a and 4b for inputting the transmission signal from the oscillator 3. In consideration of the size and sensibility of the whole area in which a human body can be detected, power consumption may be suppressed compared with the case where a transmission signal is continuously input to one of the transmission/reception circuits 4a and 4b.

Description

  The present invention relates to a lighting fixture with a Doppler sensor.

  2. Description of the Related Art Conventionally, there has been provided a luminaire with a Doppler sensor that detects a human body with a Doppler sensor and switches the light source on and off according to the detection of the human body (see, for example, Patent Document 1). In this type of luminaire, useless power consumption due to the user forgetting to turn off the light source can be suppressed as compared with the case where the light source is turned on / off manually.

  The Doppler sensor described above transmits (irradiates) a radio wave (transmission wave) such as a millimeter wave to a detection range, receives a radio wave (reflected wave) reflected in the detection range, and obtains an electric wave obtained by the reception. The signal is mixed (multiplied) with an electric signal having the same frequency as the transmission wave, and a Doppler signal is obtained by extracting a frequency band component corresponding to the moving speed of the human body from the obtained electric signal. By comparing the amplitude of the Doppler signal with a predetermined determination threshold, it is possible to determine the presence or absence of a human body within the detection range.

  Other sensors that detect the human body include, for example, a heat ray sensor (so-called PIR sensor) that detects heat rays emitted from the human body. Compared with a heat ray sensor, the Doppler sensor has an advantage that it is less susceptible to an environmental temperature change and an advantage that it can detect a human body at a relatively long distance. Due to the above advantages, the Doppler sensor is suitable for use in a place where the temperature changes more rapidly than in the case of a heat ray sensor, or for a usage pattern in which the Doppler sensor is attached to the ceiling in a building with a high ceiling.

JP 2009-168778 A

  In the above Doppler sensor, if it is attempted to secure sensitivity with a wide detection range, power consumption increases.

  This invention is made | formed in view of the said reason, The objective is to provide the lighting fixture with a Doppler sensor which can suppress power consumption.

  The luminaire with a Doppler sensor according to the present invention generates a Doppler signal by transmitting a radio wave to a detection range and receiving a radio wave reflected by the detection range, and generates a Doppler signal based on the Doppler signal. A Doppler sensor that determines presence or absence; and a lighting device that controls a lighting state of an electrical light source according to a determination result of the Doppler sensor, wherein the Doppler sensor periodically changes the detection range. To do.

  In the above-mentioned lighting fixture with a Doppler sensor, the Doppler sensor performs transmission / reception of radio waves and generation of a Doppler signal for different detection ranges, and determines a human body based on the Doppler signal, and a plurality of Doppler circuits And a switching circuit that periodically switches the Doppler circuit to be operated.

  Alternatively, in the above-described lighting fixture with a Doppler sensor, the Doppler sensor transmits and receives radio waves to and from different detection ranges during a period in which the transmission signal is input and an oscillator that generates a transmission signal of a predetermined frequency. A plurality of transmission / reception circuits for generating a Doppler signal, a determination circuit for determining presence / absence of a human body based on the Doppler signal, and a switching circuit for periodically switching the transmission / reception circuit for inputting the transmission signal. Is desirable.

  According to the present invention, it is possible to suppress power consumption for the range of the range in which a human body can be detected and the sensitivity, compared to the case where radio waves are continuously transmitted and received over the entire fixed detection range. .

It is a block diagram which shows embodiment. (A) and (b) each show an example of the shape of the detection range in the same as above, (a) is a front view, (b) is a top view. It is explanatory drawing which shows an example of the shape of the detection range in the same as the above. In the same as above, each of the transmission / reception circuits 4a and 4b is an explanatory diagram showing an example of a period during which a transmission signal is input and turned on. FIG. 5 is an explanatory diagram showing another example of a period during which a transmission signal is input and turned on for each of the transmission / reception circuits 4a and 4b. FIG. 6 is an explanatory diagram showing still another example of a period during which a transmission signal is input and turned on for each of the transmission / reception circuits 4a and 4b. FIG. 5 is an explanatory diagram showing another example of a period during which a transmission signal is input and turned on for each of the transmission / reception circuits 4a and 4b. It is a block diagram which shows the example of a change same as the above. (A) and (b) each show an example of the shape of the detection range in the example of FIG. 8, (a) is a front view, (b) is a top view. It is a perspective view which shows another example of the shape of the detection range in the example of FIG. In the example of FIG. 8, each of the transmission / reception circuits 4 a to 4 c is an explanatory diagram illustrating an example of a period during which a transmission signal is input and turned on.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  As shown in FIG. 1, the present embodiment includes a Doppler sensor 1 and a lighting device 2 that controls the lighting state of the electrical light source 20 according to the determination result of the Doppler sensor 1. This embodiment is a street light, and as shown in FIG. 2A, the Doppler sensor 1, the lighting device 2, and the light source 20 are fixed to the pole 8, the light source 20 illuminates the lower side, and the Doppler sensor 1 is shown in FIG. 2 (a) and (b) detect the human body 10 moving downward as indicated by the arrow A1.

  The Doppler sensor 1 includes an oscillator 3, two transmission / reception circuits 4 a and 4 b, a determination circuit 6, and a switching circuit 7. The oscillator 3 generates a transmission signal having a predetermined frequency (for example, 24 GHz). Each of the transmission / reception circuits 4a and 4b generates a Doppler signal by transmitting / receiving radio waves to / from the detection ranges Za and Zb that are different for each of the transmission / reception circuits 4a and 4b only during a period in which the transmission signal is input. Further, the determination circuit 6 determines the presence / absence of the human body 10 based on the Doppler signals generated by the transmission / reception circuits 4a and 4b. The switching circuit 7 is interposed between the oscillator 3 and each of the transmission / reception circuits 4a and 4b, and periodically switches the transmission / reception circuits 4a and 4b to which the transmission signal from the oscillator 3 is input, thereby periodically changing the detection range. To change.

  Each of the transmission / reception circuits 4 a and 4 b includes a transmission antenna 41, a reception antenna 42, and a mixer 43. The transmission antenna 41 converts a transmission signal, which is an electrical signal input from the oscillator 3 via the switching circuit 7, into a radio wave and transmits the radio wave to the detection ranges Za and Zb for each of the transmission / reception circuits 4a and 4b. The receiving antenna 42 receives radio waves from the detection ranges Za and Zb and converts them into received signals that are electrical signals. Furthermore, the mixer 43 mixes (multiplies) the transmission signal and the reception signal, and generates a Doppler signal by extracting a component in a predetermined frequency band corresponding to the moving speed of the human body 10 from the multiplied signal. That is, the mixer 43 includes a known filter circuit (for example, a low-pass filter).

  For example, as shown in FIGS. 2A and 2B, one of the transmission / reception circuits 4b is for a cone-shaped detection range (hereinafter referred to as “second detection range”) Zb having the Doppler sensor 1 as a vertex. The other transmission / reception circuit 4a transmits / receives radio waves to / from the detection range Za (hereinafter referred to as "first detection range") Za surrounding the second detection range Zb. It is supposed to be. The shapes of the detection ranges Za and Zb in a cross section including a vertical line passing through the Doppler sensor 1 are as shown in FIG. 3, for example.

  For example, as illustrated in FIG. 4, the switching circuit 7 periodically switches between the transmission / reception circuits 4 a and 4 b that input transmission signals every 50 ms. Each of the transmission / reception circuits 4a and 4b is turned on only during a period in which a transmission signal is input to generate a Doppler signal. Therefore, by the above switching, the detection range in which the human body 10 is detected is alternately and periodically switched every 50 ms between the first detection range Za and the second detection range Zb.

  For example, the determination circuit 6 compares the amplitude of the Doppler signal input from the transmission / reception circuits 4a and 4b via the appropriate amplifier circuit 5 with a predetermined determination threshold. If the amplitude of the Doppler signal is equal to or greater than the determination threshold, the detection range It is determined that the human body 10 exists in Za and Zb, and if the amplitude of the Doppler signal is less than the determination threshold, it is determined that the human body 10 does not exist in the detection ranges Za and Zb.

  As the light source 20, for example, a known electrical light source such as a light emitting diode or a fluorescent lamp can be used. As the lighting device 2, a known DC power supply circuit can be used when a light emitting diode is used as the light source 20, and a known electronic ballast is used when a fluorescent lamp is used as the light source 20. it can. Further, the lighting device 2 turns on the light source 20 until at least a predetermined control delay time elapses after the determination circuit 6 determines that the human body 10 exists in the detection ranges Za and Zb, and the determination circuit 6 detects the detection range Za. , Zb, the light source 20 is turned off when the duration of the state in which it is determined that the human body 10 does not exist reaches the control delay time.

  Since both the Doppler sensor 1 and the lighting device 2 as described above can be realized by a known technique, detailed illustration and description thereof are omitted. As a structure, it is not necessary that all the components of the Doppler sensor 1 are housed in one housing. For example, the amplification circuit 5 and the determination circuit 6 are different from the transmission / reception circuits 4a and 4b, respectively. You may accommodate with the lighting device 2 in the housing.

  According to the above configuration, the entire range in which the human body 10 can be detected (in the above example, the two detection ranges Za and Zb) is compared with the case where transmission signals are continuously input to the single transmission / reception circuits 4a and 4b. Power consumption can be suppressed for the size and sensitivity of the entire range.

  Here, a plurality of (for example, two) Doppler circuits (for example, two) having an oscillator 3 and a determination circuit 6 for each of the transmission / reception circuits 4a and 4b and having one oscillator 3, one transmission / reception circuit 4a and 4b, and one determination circuit 6 The above effect can be obtained even if the switching circuit 7 periodically switches the Doppler circuit to be operated. In this case, the switching circuit 7 periodically turns on / off the power supply to each Doppler circuit so as to periodically change the Doppler circuit to which power is supplied, for example. However, there is an advantage that the number of parts can be reduced when the oscillator 3 and the determination circuit 6 are shared by the plurality of transmission / reception circuits 4a and 4b as in the present embodiment.

  The operation of the switching circuit 7 is not limited to the above. For example, as shown in FIG. 5, the length of each period during which a transmission signal is input is set to 80 ms for one transmission / reception circuit 4a and 20 ms for the other transmission / reception circuit 4b. May be different. Alternatively, as shown in FIGS. 6 and 7, a period during which no transmission signal is input to any of the transmission / reception circuits 4a and 4b may be provided. In the example of FIG. 6, after a transmission signal is input to one transmission / reception circuit 4a for 40 ms, a transmission signal is input to the other transmission / reception circuit 4b for 10 ms, and then the transmission signal is transmitted to any of the transmission / reception circuits 4a and 4b. The operation of not inputting is repeated. Further, in the example of FIG. 7, the transmission / reception circuit 4a has a period of 40 ms in which a transmission signal is input and a period of 40 ms in which the transmission signal is input to the other transmission / reception circuit 4b. , 4b are alternately repeated with a 10 ms long period during which no transmission signal is input. 4 to 7, the length of one cycle of the operation of the switching circuit 7 is 100 ms. However, the length of one cycle of the operation of the switching circuit 7 can be changed as appropriate.

  Furthermore, the number of transmission / reception circuits 4a and 4b and detection ranges Za and Zb is not limited to two, and may be three or more. For example, when three transmission / reception circuits 4a to 4c are provided as shown in FIG. 8, the three detection ranges Za to Zc corresponding to the transmission / reception circuits 4a to 4c on a one-to-one basis are shown in FIGS. 9 (a) and 9 (b). As shown in FIG. 10, it may be arranged in a straight line or in an L shape as shown in FIG. As an operation of the switching circuit 7, for example, as shown in FIG. 11, after a transmission signal is input to one of the transmission / reception circuits 4a to 4c for 20 ms, the transmission signal is transmitted to any of the transmission / reception circuits 4a to 4c for 10 ms. Is repeated while cyclically changing the transmission / reception circuits 4a to 4c for inputting the transmission signal. In this case, the operation cycle of the switching circuit 7 is 90 ms.

DESCRIPTION OF SYMBOLS 1 Doppler sensor 2 Lighting device 3 Oscillator 4a-4c Transmission / reception circuit 6 Judgment circuit 7 Switching circuit Za-Zc Detection range

Claims (3)

A Doppler sensor for generating a Doppler signal by transmitting a radio wave to the detection range and receiving a radio wave reflected by the detection range and determining the presence or absence of a human body in the detection range based on the Doppler signal;
A lighting device that controls the lighting state of the electrical light source according to the determination result of the Doppler sensor,
The Doppler sensor is a lighting fixture with a Doppler sensor, wherein the detection range is periodically changed. The Doppler sensor is
A plurality of Doppler circuits that perform transmission / reception of radio waves and generation of Doppler signals for different detection ranges and determine the presence or absence of a human body based on the Doppler signals,
The lighting apparatus with a Doppler sensor according to claim 1, further comprising a switching circuit that periodically switches the Doppler circuit to be operated. The Doppler sensor is
An oscillator that generates a transmission signal of a predetermined frequency;
A plurality of transmission / reception circuits for generating a Doppler signal by transmitting / receiving radio waves to / from different detection ranges during a period in which the transmission signal is input;
A determination circuit for determining the presence or absence of a human body based on the Doppler signal;
The lighting apparatus with a Doppler sensor according to claim 1, further comprising a switching circuit that periodically switches the transmission / reception circuit that inputs the transmission signal.

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