JPH06242258A - Human body detector - Google Patents

Abstract

PURPOSE:To provide a human body detector capable of extending the life of a sensor and preventing the erroneous operation due to a neighboring heat source. CONSTITUTION:A human body detector has a pyroelectric sensor 4 detecting the presence of the human body moving within a first predetermined detection area, the distance measuring sensor 5 provided in the first detection area and detecting the presence of the human body stationary in a second detection area narrower than the first detection area and a control circuit 3 setting the distance measuring sensor 5 to an operative state by the detection output of the pyroelectric sensor 4 and setting the sensor 5 to an operation stop state when the non-detection state of both sensors 4, 5 is continued for a predetermined time to detect the presence of the human body on the basis of the detection outputs of the sensors 4, 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a human body detecting device for detecting the presence of a human body.

[0002]

2. Description of the Related Art Some human body detecting devices detect the presence of a human body by utilizing radiant heat from the human body. In this device, radiant heat from the human body is received by the thermopile used as a sensor. Then, this device detects the presence of a human body based on the detection output from the thermopile.
Such a human body detection device is described in Japanese Patent Laid-Open No. 64-65888.

Some human body detection devices use a light emitting element and a light receiving element as a sensor for detecting the presence of a human body. Then, this device makes the light from the light emitting element into a slit (band) shape, and emits the slit-shaped beam light. The reflected light of this beam light is received by a plurality of light receiving elements,
The presence of a human body is detected based on the change in the current from each light receiving element. Such a human body detecting apparatus is disclosed in Japanese Patent Laid-Open No. 2-126.
719.

By using these human body detection devices, the presence of a moving human body or a stationary human body can be detected.

[0005]

By the way, in a human body detecting device using a thermopile, if there is a heat source such as a heating device in the vicinity of this device, this heat causes a human body to be detected and malfunctions occur.

Further, in the human body detecting device using the slit-shaped beam light, the optical system of the light projecting means for emitting this light and the condensing means for condensing the slit-shaped reflected light becomes complicated, and the production cost is increased. Invite. Further, in this device, the light emitting element of the sensor always emits light, so that the life of the light emitting element is shortened.

An object of the present invention is to eliminate the above drawbacks and to provide a human body detecting device which can extend the life of the sensor and prevent malfunction due to a nearby heat source.

[0008]

In order to achieve the object, the present invention provides a passive sensor for detecting the presence of a human body moving in a predetermined first detection area, and a passive sensor in the first detection area. , An active sensor that detects the presence of a human body that is stationary in a second detection area that is narrower than the first detection area, and activates the active sensor by the detection output of the passive sensor, and does not detect the passive sensor and the active sensor And a control means for detecting the presence of a human body based on the detection outputs of the passive sensor and the active sensor by putting the active sensor into a deactivated state when the state continues for a predetermined time.

According to the present invention, the scanning driving means for scanning the active sensor is provided.

In the present invention, the passive sensor is a pyroelectric sensor that detects the presence of the human body based on the infrared rays from the human body.

Further, in the present invention, the active sensor is
It is a distance measuring sensor that detects the presence of a human body based on a change in the measured distance.

[0012]

According to the present invention, a person enters the first detection area,
When moving in the first detection area, the passive sensor detects the presence of a human body. Upon receiving this detection output, the control means starts the operation of the active sensor. After that, when a person enters the second detection area and stands still, the active sensor detects the presence of this standing human body. When a person leaves the second detection area, the passive sensor detects the presence of the human body. Further, when exiting the first detection area, the control means
Deactivate the active sensor.

The control means detects the presence of the human body by the detection output of at least one of the passive type sensor and the active type sensor when a person moves in the first detection area and stands still in the second detection area. .

Further, the scanning driving means scans the active sensor to detect the presence of a stationary human body.

Further, by using the pyroelectric sensor as the passive sensor, when the human body is moving, the presence of the moving human body is detected based on the infrared rays generated by the human body.

Further, by using the distance measuring sensor as the active sensor, when the human body is stationary, the presence of the stationary human body is detected based on the change in the measured distance.

[0017]

Embodiments of the present invention will now be described with reference to the drawings.

[First Embodiment] FIG. 1 shows a first embodiment of the present invention.
It is a block diagram showing. The human body detection apparatus according to the first embodiment is
A power supply circuit 1, a drive circuit 2, a control circuit 3 as a control unit, a pyroelectric sensor 4 as a passive sensor, and a distance measuring sensor 5 as an active sensor are provided.

The power supply circuit 1 of the human body detecting device generates a DC voltage from the AC voltage of the commercial power supply 11 and supplies the DC voltage to each circuit. Further, the power supply circuit 1 supplies an AC voltage from the commercial power supply 11 to the drive circuit 2.

The drive circuit 2 supplies the AC voltage of the power supply circuit 1 to the load 12 by the control output from the control circuit 3.
That is, the drive circuit 2 operates like a switch that turns on and off the AC voltage from the power supply circuit 1 with respect to the load 12.

The pyroelectric sensor 4 is a differential type sensor having a pyroelectric element (not shown). The pyroelectric element is polarized in a steady state and maintains electrical neutrality due to the attachment of electric charges in the air. In this state, when the pyroelectric element absorbs far infrared rays generated by the human body, the temperature of the pyroelectric element rises and the polarization state changes. Due to this change, the pyroelectric element releases the attached charge, so that a current is temporarily generated. The pyroelectric sensor 4 detects the presence of a human body by the electric current generated by the pyroelectric element. However, when the pyroelectric element releases the charge, the attached charge matches the polarization, so
No current is generated. As a result, the pyroelectric sensor 4 detects only the presence of a moving human body.

Further, since the pyroelectric sensor 4 detects the presence of the human body by the far infrared rays generated by the human body, the presence of the human body can be detected over a wide range. That is, as shown in FIG. 2, the detection area 21 of the pyroelectric sensor 4 becomes wider.

The distance measuring sensor 5 is an infrared emitting LED (Ligh
t Emitting Diode) and PSD (Position Sensitive D)
evice) and. In addition, infrared emitting LED and P
SD is not shown in FIG. The distance measuring sensor 5 is
When the PSD receives infrared reflected light from the infrared emitting LED, the distance between the sensor and the reflection position is measured from the positional deviation of the reflected light. That is, the distance measuring sensor 5 is
The distance when the person does not exist is compared with the distance when the person exists, and the presence of the human body is detected based on the change of the distance information. Therefore, since the distance measuring sensor 5 utilizes reflection of infrared light, the distance measuring sensor 5 can detect the distance only in a narrow range. That is, as shown in FIG. 2, the detection area 22 of the distance measuring sensor 5 is narrower than that of the pyroelectric sensor 4.

Such an operation of the distance measuring sensor 5 is controlled by a control output from the control circuit 3. That is, when the distance measuring sensor 5 receives the control output of "H (high)" from the control circuit 3, it emits infrared rays from the infrared ray emitting LED to be in an operating state capable of detecting the presence of a human body, When the control output is "L", the operation is stopped.

The control circuit 3 controls the pyroelectric sensor 4 and the distance measuring sensor 5. The control circuit 3 detects the presence of a human body from the pyroelectric sensor output from the pyroelectric sensor 4 and the distance measuring sensor output from the distance measuring sensor 5, generates a control output, and drives this control output. Send to circuit 2. In addition, the control circuit 3 always activates the pyroelectric sensor 4 to cause the pyroelectric sensor 4 to operate.
Detects the presence of a human body, it controls the distance measuring sensor 5 to operate.

Next, the operation of the first embodiment will be described by taking the case of turning on and off the illumination of the toilet using the first embodiment. Here, as shown in FIG. 3, the human body detection device is
It is attached to the ceiling 30 of the toilet and above the toilet bowl 31 of the toilet. Further, the lighting fixture 32 is used as the load 12.

When the human body detection device is attached to the ceiling 30 of the toilet, the detection area 21 of the pyroelectric type sensor 4 of the human body detection device covers the entire toilet. Also, the distance measuring sensor 5
The detection area 22 is around the toilet 31. And
Under the control of the control circuit 3, only the pyroelectric sensor 4 is operating.

In such a state, when the person 101 tries to use the toilet, as shown in FIG. 4, at time T1, the door 30A of the toilet is opened and the person enters. At this time, the pyroelectric sensor 4 detects the presence of the person 101, and the "H"
Is sent to the control circuit 3. The control circuit 3 sends the output of “H” to the drive circuit 2 and the distance measuring sensor 5 by the output of the pyroelectric sensor. This control output causes the distance measuring sensor 5 to start operating. At the same time, this control output causes the drive circuit 2 to start lighting the lighting fixture 32.

When the person 101 enters the detection area 22 of the distance measuring sensor 5 at time T2, the distance measuring sensor 5 generates an output of "H" and sends it to the control circuit 3. After this, at time T3, the person 10
When 1 stops in front of the toilet bowl 31 or sits down on the toilet bowl 31, the pyroelectric sensor 4 does not detect the presence of the stationary person 101, that is, the non-detection state, so the output of the pyroelectric sensor 4 Becomes "L". However, since the output of the distance measuring sensor of "H" has already been added to the control circuit 3, the control circuit 3 continues to send the output of "H" to the drive circuit 2. With this control output, the drive circuit 2 causes the lighting fixture 32 to continue lighting.

Time T4 for person 101 to leave the toilet
, The pyroelectric sensor 4 outputs “H” output to the control circuit 3
Send to. Then, when the person 101 goes out of the detection area 22 of the distance measuring sensor 5 at time T5, the distance measuring sensor 5 sends the output of “L” to the control circuit 3. However, at this time, "H"
Since the output of the pyroelectric sensor of 1 is added to the control circuit 3, the control circuit 3 continues to send the output of “H” to the drive circuit 2. As a result, the drive circuit 2 keeps lighting the lighting fixture 32.

When the person 101 leaves the toilet at time T6,
Since it is outside the detection area 21 of the pyroelectric sensor 4, the pyroelectric sensor 4 sends an output of “L” to the control circuit 3. When this pyroelectric sensor output is applied, the control circuit 3 sets the output to "L" after the elapse of the timer time, that is, at time T7.
By this control output, the drive circuit 2 turns off the lighting fixture 32.

As described above, according to the first embodiment, when the person 101 is in the toilet, the lighting device 32 is automatically turned on and the inside of the toilet is kept bright. At this time, since the distance measuring sensor 5 operates after the pyroelectric sensor 4 detects the presence of the person 101, the life of the infrared emitting LED used in the distance measuring sensor 5 can be extended and the power consumption can be reduced. It can reduce consumption.

Further, since the pyroelectric type sensor 4 and the distance measuring sensor 5 are properly used, it can be surely detected whether or not the person 101 is in the toilet.

In the first embodiment, one distance measuring sensor 5 is used, but it is not limited to this. For example, as shown in FIG. 5, two distance measuring sensors are used, and one of the distance measuring sensors has a detection area 51 at substantially the center of the upper part of the toilet bowl 31,
The other distance measuring sensor detects the area before the toilet bowl 31 in the detection area 52.
May be Further, as shown in FIG. 6, three distance measuring sensors are used. The first distance measuring sensor is the toilet bowl 31.
The rear of the upper part of the toilet is the detection area 61, and the second distance measuring sensor is the front of the upper part of the toilet bowl 31 as the detection area 62.
The second distance measuring sensor detects the area before the toilet bowl 31 in the detection area 63.
May be As described above, by using the plurality of distance measuring sensors, the inside of the toilet is surely illuminated according to different usage situations of the toilet.

Although the distance measuring sensor 5 is used as the active sensor in the first embodiment, the active sensor is not limited to this, and may be an active sensor using a photodiode or a phototransistor instead of the PSD, for example. At this time, the presence of reflected light is checked to detect the presence of a human body.

Further, an active sensor using ultrasonic waves may be used instead of the infrared reflective active sensor. At this time, the presence of a reflected wave may be checked to detect the presence of the human body, or the distance may be checked from the reflection time.

Further, in the operation of the first embodiment, the lighting equipment of the toilet is used as the load 12, but it is not particularly limited to the toilet and the lighting equipment. For example, a ventilation fan, an air conditioner, various alarm devices, etc. may be used as the load 12.

[Second Embodiment] FIG. 7 shows a second embodiment of the present invention.
It is a block diagram showing. The human body detection device according to the second embodiment is similar to the human body detection device according to the first embodiment except that the scanning drive circuit 6 is used as the scanning drive means.
Is added.

As shown in FIG. 8, the scanning drive circuit 6 causes the distance measuring sensor 5 to scan in the A direction by the control means of the control circuit 3 by driving means (not shown) such as a stepping motor. That is, when the control circuit 3 generates an output of "H" by the pyroelectric sensor output indicating the human body detection of the pyroelectric sensor 4, the scanning drive circuit 6 scans the distance measuring sensor 5 by this control output. Let

In the second embodiment, the scanning drive circuit 6 is used to detect the detection area 22 of the distance measuring sensor 5 as shown in FIG.
Back and forth by angle B. As a result, the detection area of the toilet bowl 31 and the distance measuring sensor 5 in front of it can be expanded, the lighting fixture 32 can be reliably operated, and malfunction of the lighting fixture 32 is prevented.

In the second embodiment, one distance measuring sensor 5
Are scanned, but the invention is not limited to this. For example, as shown in FIG.
A to 5E are arranged on the ceiling at right angles to the direction A, and the distance measuring sensors 5A to 5E are simultaneously scanned in the direction A.

At this time, the control circuit 3 controls the distance measuring sensors 5A to 5E in time series so that the distance measuring sensors 5A to 5E do not interfere with each other, as shown in FIG. That is, when the operation of the scanning drive circuit 6 is started, the control circuit 3 sets the control output to be sent to the distance measuring sensor 5A to "H" only from the time T11 to the time T12. As a result, the distance measuring sensor 5A detects. Next, the control output sent to the distance measuring sensor 5B is set to "H" only from the time T12 to the time T13. Then, after the control output of "H" is sent to the distance measuring sensor 5E only during the time T15 to T16, the control output of "H" is sent again to the distance measuring sensor 5A.

By controlling the distance measuring sensors 5A to 5E in this manner, as shown in FIG.
The same detection as when the 5Es are arranged in a matrix is possible.

The scanning drive device 6 operates after the pyroelectric sensor 4 detects the presence of a human body, so that the second embodiment will be described.
Can extend the life of the scanning drive device 6.

[0045]

As described above, the present invention makes it possible to prolong the life of an active sensor because the active sensor operates after the passive sensor detects the presence of a human body. Further, according to the present invention, the radiation heat from the human body is used in the pyroelectric sensor, but since it is the differential type sensor, malfunction due to a nearby heat source can be prevented and the detection accuracy of the presence of the human body can be improved.

[Brief description of drawings]

FIG. 1 is a block diagram showing a first embodiment of the present invention.

FIG. 2 is a diagram showing detection areas of a pyroelectric sensor and a distance measuring sensor.

FIG. 3 is a diagram showing a state in which the human body detection device according to the first embodiment is attached to a toilet.

FIG. 4 is a time chart showing a processing flow of the first embodiment.

FIG. 5 is a diagram showing a detection area when two distance measuring sensors are used in the first embodiment.

FIG. 6 is a diagram showing a detection area when three distance measuring sensors are used in the first embodiment.

FIG. 7 is a block diagram showing a second embodiment of the present invention.

FIG. 8 is a diagram showing a scanning direction of a distance measuring sensor in the second embodiment.

FIG. 9 is a diagram showing a scanning range of a distance measuring sensor in the second embodiment.

FIG. 10 is a diagram showing an arrangement of a plurality of distance measuring sensors.

FIG. 11 is a diagram showing a state when a plurality of distance measuring sensors are scanned.

FIG. 12 is a time chart for time-sequentially controlling a plurality of distance measuring sensors.

[Explanation of symbols]

 3 Control circuit 4 Pyroelectric sensor 5 Distance measuring sensor

Claims (4)

[Claims] 1. A passive sensor for detecting the presence of a human body moving in a predetermined first detection area, and a stationary second detection area within the first detection area and narrower than the first detection area. When an active sensor that detects the presence of a human body, the active sensor is activated by the detection output of the passive sensor, and the non-detection state of the passive sensor and the active sensor continues for a predetermined time. A human body detection device, comprising: a control unit that detects the presence of a human body based on the detection outputs of the passive sensor and the active sensor when the active sensor is in a deactivated state. 2. The human body detection device according to claim 1, further comprising a scan driving unit that scans the active sensor. 3. The human body detection device according to claim 1, wherein the passive sensor is a pyroelectric sensor that detects the presence of a human body based on infrared rays from the human body. 4. The human body detection device according to claim 1, wherein the active sensor is a distance measurement sensor that detects the presence of a human body based on a change in the measured distance.