JP2014010127A - Infrared detection device, illumination device, illumination control device and illumination system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the generation of a popcorn noise, and to prevent erroneous detection with simple configurations.SOLUTION: A human detection sensor device 12 includes: a pyroelectric sensor 21; switching elements 241 to 243; and a control circuit 31. The pyroelectric sensor 21 converts a temperature change generated by receiving infrared light into an electric signal by pyroelectric effects. The switching element 241 is electrically connected between the power supply terminal and ground terminal of the pyroelectric sensor 21. The switching element 242 is electrically connected between the power supply terminal and output terminal of the pyroelectric sensor 21. The switching element 243 is electrically connected between the output terminal and ground terminal of the pyroelectric sensor 21. Each time a reset period passes, the control circuit 31 turns on the switching elements 241 to 243 during the reset time.

Description

  The present invention relates to an infrared detection device that detects infrared rays.

  The pyroelectric sensor detects infrared rays emitted from a human body or the like using the pyroelectric effect. The pyroelectric sensor may generate a sudden voltage called popcorn noise. For this reason, there exists an infrared detection apparatus which has the structure which prevents the erroneous detection by popcorn noise.

JP 2002-71832 A

The conventional infrared detection device is based on the premise that popcorn noise is generated, and prevents erroneous detection by discriminating popcorn noise, and has a complicated configuration.
An object of the present invention is, for example, to suppress occurrence of popcorn noise and prevent erroneous detection with a simple configuration.

  An infrared detection device according to the present invention includes a pyroelectric sensor, a switching element electrically connected between a plurality of terminals of the pyroelectric sensor, and the switching element at a predetermined time at least once during a predetermined period. And a control circuit that is turned on.

  According to the infrared detection device of the present invention, the occurrence of popcorn noise can be suppressed and erroneous detection can be prevented with a simple configuration.

1 is a diagram illustrating an overall configuration of a lighting system 10 according to Embodiment 1. FIG. FIG. 3 is a diagram showing an outline of a configuration of a human sensor device 12 in the first embodiment. FIG. 3 is a diagram showing a specific circuit configuration of human sensor device 12 in the first embodiment. FIG. 5 shows a flow of operations of the human sensor device 12 in the first embodiment. FIG. 6 is a diagram illustrating operation timing of the human sensor device 12 according to the first embodiment.

Embodiment 1 FIG.
The first embodiment will be described with reference to FIGS.

  FIG. 1 is a diagram showing an overall configuration of a lighting system 10 according to this embodiment.

The lighting system 10 (lighting control system) includes, for example, a human sensor device 12, a lighting control device 14, and a lighting fixture 16.
The human sensor device 12 detects whether or not there is a person near the lighting fixture 16.

The lighting control device 14 controls the lighting fixture 16 according to the detection result by the human sensor device 12 or the like. The illumination control device 14 includes, for example, a control device 41 and a human sensor device 42.
Similar to the human sensor device 12, the human sensor device 42 detects whether or not there is a person near the lighting fixture 16.
The control device 41 generates a signal for controlling lighting of the lighting fixture 16, illuminance, and the like according to the detection results of the human sensor device 12 and the human sensor device 42. The control device 41 transmits the generated signal to the lighting fixture 16.

The lighting fixture 16 (lighting device) turns on the light source according to the detection result by the human sensor device 12 and the control by the lighting control device 14. The lighting fixture 16 includes, for example, a lighting device 61, a human sensor device 62, and a light source 63.
The human sensor device 62 detects whether or not there is a person in the vicinity of the lighting fixture 16, similarly to the human sensor device 12 and the human sensor device 42.
The lighting device 61 converts power supplied from an external power source or a built-in power source into power for lighting the light source 63 and supplies the power to the light source 63. The light source 63 is turned on by the power supplied from the lighting device 61.
The lighting device 61 turns on the light source 63 in accordance with the detection result from the human sensor device 12 and the human sensor device 62 and the instruction from the illumination control device 14.

In addition, the structure which uses the lamp etc. which have the light source 63 instead of having the light source 63 connected to the light fixture 16 may be sufficient.
The lighting system 10 may have a configuration including any number of the human sensor devices 12, the lighting control device 14, and the lighting fixture 16. The illumination system 10 may have a configuration without the human sensor device 12. The illumination control device 14 may have a configuration without the human sensor device 42. The lighting system 10 may be configured without the lighting control device 14. The lighting fixture 16 may be configured not to incorporate the human sensor device 62. The lighting system 10 may have at least one of the human sensor device 12, the human sensor device 42 built in the lighting control device 14, and the human sensor device 62 built in the lighting fixture 16. That's fine.

  FIG. 2 is a diagram showing an outline of the configuration of the human sensor device 12 in this embodiment.

  Since the human sensor device 42 and the human sensor device 62 have the same configuration, the description thereof is omitted.

  The human sensor device 12 (infrared detector) includes, for example, a pyroelectric sensor 21, a DC power supply 22, three switching elements 241 to 243, a control circuit 31, and a detection circuit 32.

  The pyroelectric sensor 21 (human sensor) is a sensor (pyroelectric infrared sensor) that converts a temperature change caused by receiving infrared rays emitted from a human body into an electrical signal by a pyroelectric effect. The pyroelectric sensor 21 includes, for example, a lens and a pyroelectric body (not shown). The pyroelectric sensor 21 has three terminals. The three terminals are a power supply terminal, a ground terminal, and an output terminal, respectively. The pyroelectric sensor 21 operates by receiving power supply from a DC power supply 22 electrically connected to a power supply terminal and a ground terminal. The electrical signal generated by the pyroelectric sensor 21 is output as a potential difference between the output terminal and the ground terminal.

The DC power source 22 outputs DC power having a predetermined voltage.
The switching elements 241 to 243 (switches) are turned on / off according to a control signal from the control circuit 31. The switching element 241 is electrically connected between the power supply terminal and the ground terminal of the pyroelectric sensor 21. The switching element 242 is electrically connected between the power supply terminal and the output terminal of the pyroelectric sensor 21. The switching element 243 is electrically connected between the output terminal of the pyroelectric sensor 21 and the ground terminal.

The control circuit 31 controls the detection circuit 32 and the switching elements 241 to 243 according to an instruction from the outside. The control circuit 31 receives a signal representing an instruction from, for example, the lighting control device 14, the lighting fixture 16, a remote controller operated by the user, or an operation switch provided in the human sensor device 12 itself.
The instruction from the outside includes, for example, an instruction to set a cycle (reset cycle) for resetting the pyroelectric sensor 21. The control circuit 31 turns on the switching elements 241 to 243 each time the instructed reset cycle elapses. When a predetermined time elapses after the switching elements 241 to 243 are turned on, the control circuit 31 returns the switching elements 241 to 243 to off. A period during which the switching elements 241 to 243 are turned on is referred to as a “reset period”, and this time is referred to as a “reset time” (switch operation time).

  The detection circuit 32 detects a human body based on the electrical signal output from the pyroelectric sensor 21, and outputs a signal representing a detection result (human body detection state). The signal output from the detection circuit 32 is transmitted to the lighting control device 14, for example.

  FIG. 3 is a diagram showing a specific circuit configuration of the human sensor device 12 in this embodiment.

  The human sensor device 12 includes, for example, a pyroelectric sensor 21, a power supply circuit 221, a regulator circuit 222, three switching elements 241 to 243, five capacitors 251 to 255, two resistors 261 and 262, The amplifier circuit 27 and the microcomputer 30 are included.

  The power supply circuit 221 and the regulator circuit 222 correspond to the DC power supply 22 described in FIG. The power supply circuit 221 (DC power supply) converts electric power supplied from an external power supply or an internal power supply into DC power for operating the microcomputer 30. The regulator circuit 222 (regulator; second power supply) is connected to the output of the power supply circuit 221. The regulator circuit 222 lowers the voltage of the DC power generated by the power supply circuit 221 and converts it to DC power that operates the pyroelectric sensor 21.

The ground terminal of the pyroelectric sensor 21 is electrically connected to the ground wiring.
The amplifier circuit 27 amplifies the electric signal output from the pyroelectric sensor 21. The amplifier circuit 27 may be configured not only to amplify the amplitude of the electric signal, but also to amplify the pulse width of the electric signal (extend in the time direction). The amplifier circuit 27 operates with power supplied from the power supply circuit 221.
The switching elements 241 to 243 are, for example, enhancement type n-channel MOSFETs.
The capacitors 251 to 254 are noise removing capacitors. The capacitor 251 is electrically connected between the power supply terminal of the pyroelectric sensor 21 and the ground wiring. The capacitor 252 is electrically connected between the output terminal of the pyroelectric sensor 21 and the ground wiring. The capacitor 253 is electrically connected between the output terminal of the regulator circuit 222 and the input terminal of the amplifier circuit 27. The capacitor 254 is electrically connected between the input terminal of the amplifier circuit 27 and the ground wiring.
The capacitor 255 is a capacitor for removing switching noise. The capacitor 255 is electrically connected between the control input terminals of the switching elements 241 to 243 and the ground wiring.
The resistors 261 and 262 are noise removing resistors. The resistor 261 is electrically connected between the output terminal of the regulator circuit 222 and the power supply terminal of the pyroelectric sensor 21. That is, a series circuit of the resistor 261 and the pyroelectric sensor 21 is connected to the output of the regulator circuit 222. The resistor 262 is electrically connected between the output terminal of the pyroelectric sensor 21 and the input terminal of the amplifier circuit 27.

  The microcomputer 30 (control device) operates with electric power supplied from the power supply circuit 221. The microcomputer 30 includes, for example, a processing device, a storage device, an input device, and an output device (not shown). The storage device stores data and programs. The processing device (control unit) processes data by executing a program stored in the storage device, and controls the entire microcomputer 30. The input device inputs signals and information from outside the microcomputer 30 and converts them into data. The output device converts the data into a signal or information and outputs it to the outside of the microcomputer 30. In this figure, the functional blocks drawn inside the microcomputer 30 are realized by the processing device executing the program stored in the storage device. Note that these functional blocks may be realized not by the microcomputer 30 but by an electrical configuration such as a digital circuit or an analog circuit, or other configurations.

The microcomputer 30 corresponds to the control circuit 31 and the detection circuit 32 described in FIG.
The control circuit 31 includes, for example, a reception unit 311, a cycle storage unit 312, a time measurement unit 313, and a signal generation unit 314.
The detection circuit 32 includes, for example, a determination unit 321 and a transmission unit 322.

The receiving unit 311 (receiving circuit) receives a signal representing an instruction from the lighting control device 14 or the like.
The cycle storage unit 312 (storage unit) stores a reset cycle in advance. When the instruction represented by the signal received by the reception unit 311 is a reset period setting instruction, the period storage unit 312 updates the stored reset period and stores the instructed reset period.
The timer unit 313 (timer) measures the elapsed time. When the measured elapsed time reaches the reset period based on the reset cycle stored in the cycle storage unit 312, the timer unit 313 returns the elapsed time to 0 and measures the elapsed time from that point. The timer unit 313 repeats this.
The signal generation unit 314 (operation unit) generates a control signal for controlling the switching elements 241 to 243. The signal generation unit 314 generates a control signal for turning on the switching elements 241 to 243 until the reset time elapses after the elapsed time measured by the time measuring unit 313 becomes zero. In other periods, the signal generation unit 314 generates a control signal that turns off the switching elements 241 to 243.

The determination unit 321 detects a human body based on the electrical signal amplified by the amplifier circuit 27. For example, the determination unit 321 compares the voltage level of the signal output from the amplifier circuit 27 with a predetermined upper limit threshold and lower limit threshold. When the voltage level of the signal output from the amplifier circuit 27 is between the upper threshold and the lower threshold, the determination unit 321 determines that no human body exists. When the voltage level of the signal output from the amplifier circuit 27 is higher than the upper threshold or lower than the lower threshold, the determination unit 321 determines that a human body exists.
During the reset period, since the potential of the output terminal of the pyroelectric sensor 21 becomes 0, the voltage level of the signal output from the amplifier circuit 27 becomes smaller than the lower limit threshold. Therefore, the determination unit 321 does not perform a determination operation during the reset period. This can prevent erroneous determination that a human body exists.
In addition, even after the reset period ends and the switching elements 241 to 243 are turned off, the potential of the output terminal of the pyroelectric sensor 21 may not be restored immediately. The configuration 321 may restart the determination operation after a predetermined time has elapsed after the reset period.
Hereinafter, the period during which the determination unit 321 stops the determination is referred to as a “determination stop period”, and the time is referred to as a “determination stop time”. As described above, the determination stop time (determination result invalid time) is the same as the reset time or longer than the reset time.

  The transmission unit 322 transmits a signal representing the detection result by the determination unit 321 to the illumination control device 14 or the like.

  FIG. 4 is a diagram showing a flow of operation of the human sensor device 12 in this embodiment.

  The detection process 80 includes, for example, three elapsed time determination steps 81, 85, 87, a human body detection step 82, a detection result transmission step 83, a reset start step 84, and a reset end step 86.

In the elapsed time determination step 81, the timer unit 313 compares the measured elapsed time with the reset period stored in the period storage unit 312.
When the elapsed time is shorter than the reset period, the timer unit 313 advances the process to the human body detection step 82.
When the elapsed time is equal to or longer than the reset period, the time measuring unit 313 advances the process to the reset start process 84.

In the human body detection step 82, the determination unit 321 determines whether a human body exists.
In the detection result transmission step 83, the transmission unit 322 transmits the determination result by the determination unit 321. The timer unit 313 returns the process to the elapsed time determination step 81.

  In the reset start process 84, the time measuring unit 313 resets the elapsed time being measured to zero. The signal generation unit 314 outputs a control signal that turns on the switching elements 241 to 243. The switching elements 241 to 243 are turned on, and the reset period starts.

In the elapsed time determination step 85, the signal generation unit 314 compares the elapsed time measured by the time measuring unit 313 with the reset time.
When the elapsed time is shorter than the reset time, the signal generation unit 314 waits until the elapsed time reaches the reset time.
When the elapsed time is equal to or longer than the reset time, the signal generation unit 314 advances the process to the reset end process 86.

  In the reset end step 86, the signal generation unit 314 outputs a control signal for turning off the switching elements 241 to 243. The switching elements 241 to 243 are turned off, and the reset period ends.

In the elapsed time determination step 87, the determination unit 321 compares the elapsed time measured by the time measuring unit 313 with the determination stop time.
When the elapsed time is shorter than the determination stop time, the determination unit 321 waits until the elapsed time reaches the determination stop time.
When the elapsed time is equal to or longer than the determination stop time, the determination unit 321 returns the process to the elapsed time determination step 81.

  If the determination stop time is the same as the reset time, the elapsed time determination step 87 may not be provided, and the process returns to the elapsed time determination step 81 after the reset end step 86 ends.

  FIG. 5 is a diagram showing the timing of the operation of the human sensor device 12 in this embodiment.

The horizontal axis indicates time.
A solid line 91 indicates the state of the switching elements 241 to 243. During a period in which the solid line 91 is on the horizontal axis, the switching elements 241 to 243 are on (that is, a reset period). During the period when the solid line 91 is below the horizontal axis, the switching elements 241 to 243 are off.
A solid line 92 indicates the state of the determination unit 321. During the period in which the solid line 92 is on the horizontal axis, the determination unit 321 performs the determination operation. During the period when the solid line 92 is below the horizontal axis, the determination unit 321 stops the determination operation.

  The human sensor device 12 performs the reset operation of the pyroelectric sensor 21 every time the reset period 70 elapses. The switching elements 241 to 243 are turned on only during the reset time 71. The determination unit 321 stops the determination operation only during the determination stop time 72. The determination stop time 72 is the reset time 71 or more. The determination unit 321 stops the determination operation at least during the reset period. The determination unit 321 may be configured to stop the determination operation simultaneously with the start of the reset period, or may be configured to stop the determination operation before the start of the reset period. The determination unit 321 may be configured to restart the determination operation simultaneously with the end of the reset period, or may be configured to restart the determination operation after the end of the reset period.

  If a voltage is continuously applied to the pyroelectric element, electric charges accumulate on the surface of the pyroelectric element, and the electric charges become a high voltage and suddenly discharge to generate popcorn noise. The frequency of occurrence of popcorn noise is, for example, about 0 to 1 time per day.

  Therefore, the accumulated charge is discharged by periodically short-circuiting the terminals of the pyroelectric sensor, and the occurrence of popcorn noise is suppressed. As a result, erroneous detection due to popcorn noise can be prevented.

  Since the occurrence frequency of popcorn noise is about 0 to 1 times per day, the reset cycle is preferably 24 hours or less. In addition, since a setting such as a working hour unit can be considered, it is desirable that the reset cycle is 1 hour or more.

In addition, during the reset period, the determination unit 321 stops the determination operation and cannot detect a human body, so the reset time is preferably within 1 second. If the determination stop time is longer than the reset time, it is desirable that the determination stop time is within one second, so that the reset time is even shorter.
Further, if the reset time is too short, there is a possibility that the charge of the pyroelectric element cannot be removed. Since the internal and external stray capacitances of the pyroelectric element are on the order of, for example, pF, the reset time is preferably 1 millisecond or more. Considering the switching speed when using MOSFETs as the switching elements 241 to 243, the reset time is desirably 1 millisecond or more.

  The human sensor device 12 may have a configuration that does not include any one or two of the switching elements 241 to 243.

Further, the human sensor device 12 may have a configuration that can change not only the reset period but also the reset time and the determination stop time. For example, the human sensor device 12 includes a reset time storage unit and a determination stop time storage unit.
The reset time storage unit stores a reset period in advance. When the instruction represented by the signal received by the receiving unit 311 is a reset time setting instruction, the reset time storage unit updates the stored reset time and stores the instructed reset time. Based on the reset time stored in the reset time storage unit, the signal generation unit 314 outputs the switching elements 241 to 243 when the elapsed time after outputting the control signal for turning on the switching elements 241 to 243 reaches the reset time. A control signal to turn off is output.
The determination stop time storage unit stores the determination stop time in advance. The determination stop time storage unit updates the stored determination stop time and stores the instructed determination stop time when the instruction represented by the signal received by the receiving unit 311 is a determination stop time setting instruction. Based on the determination stop time stored in the determination stop time storage unit, the determination unit 321 restarts the determination operation when the elapsed time from the stop of the determination operation reaches the determination stop time.

  The configuration described above is an example, and other configurations may be used. For example, a configuration in which a configuration of a non-essential part is replaced with another configuration may be used.

According to the infrared detection apparatus described above, by short-circuiting between the terminals of the pyroelectric sensor (human sensor) at an arbitrary time, the charge inside the pyroelectric sensor is removed and the occurrence of popcorn noise is suppressed.
Rather than discriminating popcorn noise, the fundamental solution of suppressing the occurrence of popcorn noise itself can prevent erroneous detection without complicating the configuration of the infrared detection device.

  DESCRIPTION OF SYMBOLS 10 Lighting system, 12, 42, 62 Human sensor device, 14 Lighting control device, 16 Lighting fixture, 21 Pyroelectric sensor, 22 DC power supply, 221 Power supply circuit, 222 Regulator circuit, 241-243 Switching element, 251-255 Capacitor , 261, 262 Resistor, 27 Amplifier circuit, 30 Microcomputer, 31 Control circuit, 311 Reception unit, 312 Period storage unit, 313 Timekeeping unit, 314 Signal generation unit, 32 Detection circuit, 321 Judgment unit, 322 Transmission unit, 41 Control device , 61 lighting device, 63 light source, 70 reset period, 71 reset time, 72 determination stop time, 80 detection process, 81, 85, 87 elapsed time determination process, 82 human body detection process, 83 detection result transmission process, 84 reset start process 86 Reset end process, 91, 92 Solid line.

Claims (10)

A pyroelectric sensor,
A switching element electrically connected between the plurality of terminals of the pyroelectric sensor;
And a control circuit for turning on the switching element for a predetermined time at least once during a predetermined period.   The infrared detection apparatus according to claim 1, wherein the predetermined period is 1 hour or more and 24 hours or less.   The infrared detection apparatus according to claim 1, wherein the predetermined time is 1 millisecond or more and 1 second or less. The control circuit is
A cycle storage unit for storing a cycle for turning on the switching element;
A timekeeping unit for measuring an elapsed time since the switching element was previously turned on;
And a signal generation unit that generates a control signal for turning on the switching element for a predetermined time when the elapsed time measured by the time measuring unit reaches the cycle stored by the cycle storage unit. The infrared detection device according to any one of claims 1 to 3. The infrared detector is
Having a receiving circuit for receiving a command from another device;
The infrared detection device according to claim 4, wherein the cycle storage unit stores a cycle instructed by a command received by the receiving circuit. The infrared detector is
6. A detection circuit for detecting a human body based on a detection result by the pyroelectric sensor, wherein the detection circuit does not perform detection while the switching element is on. The infrared detection apparatus in any one of.   The infrared detection device according to claim 6, wherein the detection circuit further does not perform detection until a predetermined time elapses after the switching element is turned off. An infrared detection device according to any one of claims 1 to 7,
An illumination device comprising: a lighting device that turns on a light source based on a detection result of the infrared detection device. An infrared detection device according to any one of claims 1 to 7,
An illumination control device comprising: a control device that controls the illumination device based on a detection result of the infrared detection device.   It has at least any one of the infrared rays detection apparatus in any one of Claim 1 thru | or 7, the illuminating device in Claim 8, and the illumination control apparatus in Claim 9. Lighting system.

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