JP2009058463A - Human body sensing device and sanitary washing unit using same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve sensing accuracy so that variation of sensing accuracy of human detection is compensated for a change of ambient temperature using a simple circuit construction. <P>SOLUTION: The human body sensing device includes a pyroelectric sensor 610, an amplifying circuit 620 to amplify the output of the pyroelectric sensor 610, a comparator circuit 630, and a temperature sensor Rth to sense a room temperature, and in the circuit construction the output of the pyroelectric sensor 610 is input into an amplifier 621 of the amplifying circuit 620 through the temperature sensor Rth, consequently, the output voltage of the pyroelectric sensor 610, which is valuable under influence of ambient temperatures, can undergo temperature-compensation by automatically changing the amplifying rate based on the change of resistive value of a temperature sensor 623 without depending on a microcomputer software, thereby the sensing accuracy can be improved. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a circuit configuration in a human body detection device that detects a human body.

  Conventionally, as a circuit configuration of this type of human body detection device, a distance measuring sensor that detects a human body, a comparison unit that compares the output voltage of the distance measuring sensor and a reference voltage to determine the presence of a human body, and an ambient temperature Temperature sensor and a correction means that corrects the output of the distance measuring sensor based on the temperature change measured by the temperature sensor, and the output of the distance measuring sensor fluctuates due to changes in the ambient temperature due to seasonal changes, etc. In some cases, a distance measurement error is corrected by a correction means including a microcomputer based on the measurement data of the temperature sensor (for example, see Patent Document 1).

FIG. 8 shows a circuit configuration of a conventional human body detection device described in Patent Document 1. In FIG. As shown in the figure, a distance measuring sensor 2 and a temperature sensor 3 are connected to a microcomputer 1 having comparison means and correction means.
JP 2004-150240 A

  However, in the conventional configuration in the previous period, the correction means must be operated by a microcomputer, the circuit configuration becomes complicated, and the number of reference values that serve as judgment criteria is limited to the number of inputs to the microcomputer, so the detection accuracy cannot be increased. It had the problem that.

  An object of the present invention is to solve the above-mentioned conventional problems, and to realize a human body detection device capable of reducing fluctuations in the accuracy of human body detection due to the influence of ambient temperature with a simple circuit configuration. To do.

  In order to solve the above-described conventional problems, a human body detection device of the present invention includes a pyroelectric sensor that detects infrared rays, an amplification circuit that amplifies the output of the pyroelectric sensor, and a comparison circuit that determines that a person has entered the room. And a temperature sensor for detecting room temperature, and the output of the pyroelectric sensor is configured to be input to the amplifier of the amplifier circuit via the temperature sensor.

  As a result, the pyroelectric sensor output voltage, which fluctuates under the influence of the ambient temperature, can be corrected independently of the microcomputer software by automatically changing the amplification factor by changing the resistance value of the temperature sensor. Therefore, the detection criteria can be improved without any limitation on the criterion for temperature change.

  The circuit configuration of the human body detection device of the present invention can be corrected with a simple configuration against the influence of the ambient temperature, and there is no restriction on the criterion for temperature change, and the detection accuracy can be improved.

A first invention includes a pyroelectric sensor that detects infrared rays, an amplification circuit that amplifies the output of the pyroelectric sensor, a comparison circuit that determines that a person has entered the room according to the output of the amplification circuit, and a room temperature. A pyroelectric sensor that outputs a distance to an object as a voltage value by adopting a circuit configuration in which the output of the pyroelectric sensor is input to the amplifier of the amplifier circuit via the temperature sensor. In addition, the amplifier circuit for amplifying the output voltage of the pyroelectric sensor has a temperature sensor instead of a fixed resistor, so that the output voltage of the pyroelectric sensor, which fluctuates due to the influence of the ambient temperature, can be set to the resistance value of the temperature sensor. By changing the gain automatically, the temperature correction can be performed independently of the microcomputer software, and by changing the gain linearly, there is no limit to the criterion for temperature change, and the detection accuracy is improved. It is possible to above.

  The sanitary washing device of the second invention includes the human body detection device of the first invention, a main body portion installed on the upper surface of the toilet, a toilet seat portion and a lid portion pivotally supported on the main body portion, and a human body local portion By providing a nozzle unit that ejects cleaning water toward the camera and a remote control device, it is possible to reliably detect a user who has entered the toilet room regardless of changes in room temperature, and to control the sanitary cleaning device. Accuracy and reliability can be improved.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
<1> Appearance of human body detection device and sanitary washing device including the same FIG. 1 is an external perspective view showing a human body detection device and a sanitary washing device including the same according to Embodiment 1 of the present invention. The sanitary washing device 100 is installed in the toilet room.

  The sanitary washing device 100 is attached to the upper surface of the toilet bowl 700. The sanitary washing device 100 includes a main body 200, a remote operation device 300, a toilet seat 400, a lid 500, and a human body detection device 600.

  A toilet seat 400 and a lid 500 are attached to the main body 200 through a toilet seat toilet lid rotation mechanism (not shown) so as to be opened and closed electrically. The main body 200 includes a nozzle unit 800, a cleaning water supply mechanism (not shown), a drying unit, and the like.

  In FIG. 1, a seating sensor 900 provided on the upper front portion of the main body 200 is shown. The seating sensor 900 is, for example, a reflective infrared sensor. In this case, the seating sensor 900 detects the presence of a user on the toilet seat 400 by detecting infrared rays reflected from the human body.

  The cleaning water supply mechanism is connected to the nozzle unit 40. Accordingly, the cleaning water supply mechanism supplies the cleaning water supplied from the water pipe to the nozzle unit 800. Thereby, washing water is ejected from the nozzle part 800 to a local part of the user.

  The remote operation device 300 is provided with a plurality of switches. The remote control device 300 is attached to a place where a user sitting on the toilet seat 400 can operate, for example.

  The human body detection device 600 is attached to an entrance of a toilet room or the like. The detection sensor of the human body detection device 600 is a pyroelectric sensor 610 that detects infrared rays, and detects that a user has entered the toilet room when infrared rays from the human body are detected.

  The control unit of the main body 200 controls the operation of each part of the sanitary washing device 100 based on signals transmitted from the remote operation device 300, the human body detection device 600, and the seating sensor 610.

<2> Operation and action of sanitary washing apparatus The sanitary washing apparatus configured as described above operates as follows.

When the room temperature is low, such as in winter, when not in use, the temperature is adjusted by the control unit so that the toilet seat 400 has a temperature of about 18 ° C., for example. The temperature at this time is referred to as a standby temperature. Of course, when the room temperature is high in summer or the like, the toilet seat 400 is not energized.

  Here, when the user operates the toilet seat temperature adjustment switch of the remote control device 300, the toilet seat set temperature is transmitted to the control unit. The control unit stores the toilet seat set temperature received from the remote control device 300 in the storage unit of the control unit.

  When the user enters the toilet room, the human body detection device 600 detects the user's entry. Thereby, the user's entry detection signal is transmitted to the control unit.

  When the entry of the user into the toilet room is detected by the entry detection signal from the human body detection device 600, the control unit drives the toilet seat toilet lid rotation mechanism to open the toilet seat 400 and the lid 500, and the toilet seat 400. The toilet seat heater of the toilet seat 400 starts to be driven based on the measured temperature value and the toilet seat set temperature stored in the storage unit, and the temperature of the toilet seat 400 is instantaneously increased to the toilet seat set temperature, so that the toilet seat has a comfortable temperature. The user can sit on the part 400.

  After the user finishes the stool, the user operates the remote control device 300 to eject the washing water from the nozzle unit 40 to wash the local part, and also drives the drying unit to arbitrarily dry the local part after washing. be able to.

  When the user leaves the toilet room, the detection of the human body detection device 600 is finished, and when the detection signal is transmitted to the control unit, the control unit maintains the toilet seat unit at the standby temperature, and the toilet seat toilet lid rotation mechanism is installed. The toilet seat 400 and the lid 500 are driven to close.

<3> Circuit Configuration of Human Body Detection Device FIG. 2 is a circuit diagram showing a configuration of the human body detection device 600.

  As shown in the figure, the main circuit configuration of the human body detection device 600 includes a pyroelectric sensor 610 that detects the presence or absence of a human body, an amplification circuit 620 that amplifies the output signal of the pyroelectric sensor, and an amplification circuit 620 that amplifies the signal. A comparison circuit 630 that compares the detected signal with a preset reference voltage, a microcomputer 640 that determines the presence / absence of a human body based on the output of the comparison circuit 630, and a human body presence / absence signal from the human body detection device 600 to the control unit of the main body 200. A transmission unit 650 for transmission is provided. FIG. 3 is a cross-sectional view showing the configuration of the pyroelectric sensor 610.

  An optical filter 611 is installed on the outer surface of the pyroelectric sensor 610, and a pyroelectric element 612 for converting a temperature change from incident infrared rays into an electric signal is arranged inside the pyroelectric sensor 610. On the bottom surface, a source 613 terminal and a ground terminal 614 are provided.

  All objects in the natural world radiate infrared rays corresponding to the temperature of the objects from the surface, but only the infrared rays corresponding to the human body are made incident into the pyroelectric sensor 610 by the optical filter 611.

  The action of converting a temperature change from incident infrared rays into an electrical signal is called a pyroelectric action. FIG. 4 is a schematic diagram showing the pyroelectric action. As shown in the figure, normally, the pyroelectric element 612 is in a state where + and − floating charges are generated. This state is called the equilibrium state of FIG. As described above, when infrared light corresponding to the human body is incident from this equilibrium state, a part of the electric charge floating outside the pyroelectric element 612 is separated to be in an unbalanced state. At that time, the electric charge becomes an electric signal, an electrical change occurs between the source 613 of the pyroelectric sensor 610 and the ground 614, and the pyroelectric sensor 610 outputs.

  A fixed resistor R4 and a thermistor Rth, which is a temperature sensor, are connected to the input terminal of the amplifier 621 of the amplifier circuit 620. The fixed resistor R4 is connected to the source 613 of the pyroelectric sensor 610. The thermistor Rth is a pyroelectric sensor. 610 is connected to a ground 614.

  The output of the pyroelectric sensor 610 is amplified while changing the amplification factor by the fixed resistor R4 and the thermistor Rth of the amplifier circuit 620.

  When the amplified output becomes equal to or higher than the reference voltage preset in the comparison circuit 630 fixed resistors R8 and R9, the comparison circuit 630 outputs an output signal only during that period.

  When the output signal is input to the microcomputer 640, the microcomputer 640 determines that a person has entered the room and transmits a signal to the transmission unit 650.

  When a signal is sent from the microcomputer 640 to the transmission unit 650, the transmission unit 650 transmits a human body detection signal to the main body unit 200, and the control unit controls each function of the sanitary washing device 100.

  On the other hand, the output of the pyroelectric sensor 610 changes depending on the temperature difference between the ambient temperature and the body temperature of the human body that is the detection target. Although the body temperature of the human body that is the detection target is constant (about 36 ° C.) even when the ambient temperature changes, the ambient temperature varies depending on the season and time. For example, when the ambient temperature is low in winter, the body temperature When the ambient temperature in summer is high, the temperature difference between the body temperature and the ambient temperature is small, and the output of the pyroelectric sensor 610 is small.

  When the output of the pyroelectric sensor 610 changes, for example, in winter when the temperature difference is large, a considerable output may be generated even when the detection target is far away, and the human body may be erroneously detected. On the contrary, in summer when the temperature difference is small, the output is low even though the detection target is within the range to be detected, and the detection may not be possible. When the output level is the same, the distance between the pyroelectric sensor 610 and the object to be detected changes. When the ambient temperature is high, a nearby object is detected, and when the ambient temperature is low, a far object is detected. .

  In order to solve the problem caused by the change in the ambient temperature of the pyroelectric sensor 610, the amplifier circuit 620 in the present embodiment changes the amplification factor corresponding to the change in the ambient temperature by the fixed resistor R4 and the thermistor Rth. , Has a function to correct the output.

  The amplification factor E of the amplifier circuit 620 is expressed by 1 + R5 / Rth. As shown in FIG. 5, the resistance characteristics of the thermistor Rth change such that the resistance value decreases as the temperature rises. Therefore, when the ambient temperature increases, the amplification factor E increases, and when the ambient temperature decreases, the amplification factor E decreases.

  FIG. 6 shows changes in the output of the pyroelectric sensor 610 and the amplification circuit 620 depending on the temperature. When the output of the pyroelectric sensor 610 is low, the amplification factor E of the amplification circuit 620 increases, and conversely When the output of the sensor 610 is high, the amplification factor E of the amplifier circuit 620 is low. By amplifying the output of the pyroelectric sensor 610 in this embodiment having such characteristics by the amplifier circuit 620, the output of the amplifier circuit 620 becomes substantially constant even when the ambient temperature changes.

  FIG. 7 shows the amplifier circuit 620 of the present invention. This shows the characteristics of the human body detection distance when the thermistor Rth of the amplifier circuit is a fixed resistor. As shown in the figure, when the thermistor Rth is a fixed hangar, the detection distance changes due to temperature change, whereas when the thermistor Rth of this embodiment is used, the detection distance is almost constant even if the temperature changes. It becomes.

  As described above, the human body detection device in the present embodiment can detect a human body at the same level even when the ambient temperature changes due to the season or time, and the configuration for realizing it is an amplifier circuit. This is a simple configuration in which a thermistor that is a temperature sensor is arranged, and it is not necessary to incorporate complicated software or the like found in correction by a conventional microcomputer, and can realize highly accurate human body detection at low cost.

  In the present embodiment, the human body detection device is configured as an independent member of the sanitary washing device, but is not limited to this. For example, the human body detection device may be configured integrally with a remote control device or incorporated in the main body. Conceivable.

  As described above, since the human body detection device according to the present invention can detect an object at the same level even when the ambient temperature changes, the human body detection device can also be used as a detection device for animals other than human bodies, vehicles, and various products. Applicable.

1 is a perspective view of a sanitary washing device provided with a human body detection device according to Embodiment 1 of the present invention. FIG. 1 is a circuit diagram of a human body detection device according to a first embodiment of the present invention. Pyroelectric sensor sectional view in Embodiment 1 of the present invention Schematic diagram showing the pyroelectric effect in Embodiment 1 of the present invention Pyroelectric effect diagram The graph which shows the temperature characteristic of the thermistor in Embodiment 1 of this invention. The graph which shows the temperature characteristic of the output of the pyroelectric sensor in this Embodiment 1, and the gain of an amplifier circuit The graph which shows the temperature characteristic of the human body detection distance of the human body detection apparatus in Embodiment 1 of this invention Circuit diagram of a conventional human body detection device

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Sanitary washing apparatus 200 Main body part 300 Remote operation apparatus 400 Toilet seat part 500 Cover part 600 Human body detection apparatus 610 Pyroelectric sensor 620 Amplification circuit 621 Amplifier 630 Comparison circuit 700 Toilet bowl 800 Nozzle part Rth thermistor (temperature sensor)

Claims (2)

A pyroelectric sensor that detects infrared rays, an amplification circuit that amplifies the output of the pyroelectric sensor, a comparison circuit that determines that a person has entered the room according to the output of the amplification circuit, and a temperature sensor that detects room temperature A human body detection device having a circuit configuration in which an output of the pyroelectric sensor is input to an amplifier of the amplifier circuit via the temperature sensor. The human body detecting device according to claim 1, a main body portion installed on an upper surface of a toilet, a toilet seat portion and a lid portion pivotally supported on the main body portion, and a nozzle for ejecting washing water toward a human body local portion And a sanitary washing device comprising a remote control device.