JPH0453677Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a notification device that detects heat rays emitted from a human body and generates a message for guidance or advertisement.

<Prior Art> In order to display information or advertisements, letters, etc. are displayed on a guide board or a billboard, that is, a notice board, and a speaker is provided on or near the notice board to send messages. In order to send this message, it would be uneconomical to keep the speaker running all the time, so it is conceivable to detect heat rays from the human body and turn on the speaker when the human body approaches the notice board.

A pyroelectric infrared sensor, which is a type of infrared sensor that detects heat rays, that is, infrared rays, is generally used. Although this pyroelectric infrared sensor has low detection sensitivity, it is inexpensive, operates at room temperature, and has no wavelength dependence. It detects infrared rays by utilizing the pyroelectric effect, in which charges are generated on the surface due to changes in spontaneous polarization. By the way, pyroelectric infrared sensors have the drawbacks of high impedance and susceptibility to external noise, as is clear from the above operating principle of detecting temperature changes using charges generated on the surface of a pyroelectric crystal. are doing. Therefore, as shown in FIG. 9, in a pyroelectric infrared detection device 902 using this type of pyroelectric infrared sensor 901,
Concentrating mirrors M1, M2, M3 (~
Mn) is arranged to focus the infrared rays emitted from the infrared source onto the pyroelectric infrared sensor, increasing the S/N ratio. Concentrating mirror M1,
Each of M2 and M3 (~Mn) is formed to form a part of each concave curved surface, and when a human body passes through a predetermined area determined by each of the condensing mirrors M1, M2, M3 (~Mn), The light is focused on a pyroelectric infrared sensor 901 and detected.

<Problems to be solved by the invention> However, since such conventional pyroelectric infrared detectors use a relatively large condensing mirror, it has been proposed to integrate the pyroelectric infrared detector and the notice board. In this case, there was a risk that the size and shape of the notice board could not be designed freely due to restrictions due to the large condensing mirror. Therefore, it was considered to install the notice board and the pyroelectric infrared detector separately, but in this case, the installation location of the pyroelectric infrared detector and the place where the human body would pass should be considered when installing the notice board. It's necessary and it's not easy to use. For example, because the guide board and the pyroelectric infrared detection device are installed far apart, there is a disadvantage that the timing of sending a message after passing the guide board may be delayed. There was something that didn't work out yesterday.

<Means for Solving the Problems> The present invention was made to solve the above problems, and includes a notice board for displaying information or advertisements, and a system for detecting infrared rays from an object to be detected. In a notification device having a pyroelectric infrared detection device that outputs a detection signal and an audio device that generates a message, the pyroelectric infrared detection device includes a pair of pyroelectric infrared detection elements and a pair of pyroelectric infrared detection elements. This notification device is composed of a plate-shaped mirror piece placed in front of a detection element, and is disposed on a part of the surface of a notification board.

<Example> Hereinafter, an example of the notification device of the present invention will be described in detail using the drawings.

FIG. 1 is an external front view of an embodiment of the notification device according to the present invention. The notification device 1 includes a notification board 2 composed of a flat plate, a pyroelectric infrared detection device 3 disposed on the surface of the upper end of the notification board 2, and a speaker 4.
It has an audio device 5 including. On this notice board 2, a guide or advertising text corresponding to the facility or place where this notice device 1 is installed is written on a flat surface, so that passersby should pass through a predetermined spot in front of the notice board 2. Then, the pyroelectric infrared detection device 3 detects the heat rays generated from the human body. The detection signal from the pyroelectric infrared detection device 3 is received by the audio device 5, and a predetermined message can be transmitted from the speaker 4 to be heard by passersby.

Here, the pyroelectric infrared detection device 3 used in the present invention will be explained in detail. Fig. 2a is a plan view of the pyroelectric infrared detection device 3, and Fig. 2b is b of Fig. 2a.
-B is a side sectional view taken in the direction of the arrow, and has an opening 204 at the center of the upper surface 203 of a resin cylindrical housing 202;
A pyroelectric infrared sensor 205 that is housed in the housing 202 and includes a pair of pyroelectric infrared detection elements 251a and 251b is exposed to the opening 204. On the upper surface 203 of the housing 202, six mirror-finished mirror pieces 206 are arranged at equal intervals (60 degrees) around the pair of pyroelectric infrared detection elements 251a and 251b. Detection element 251
a, 251b formation surface or pyroelectric infrared sensor 2
It is installed perpendicular to the surface of 05.

FIG. 3 is a circuit diagram used in this notification device.
The same polarization side electrodes of the pyroelectric infrared detection elements 251a and 251b are directly connected, and the differential output is outputted from an emitter follower impedance conversion circuit using a field effect transistor FET, and an amplifier AMP and a comparator/waveform shaping circuit.
The speech synthesis integrated circuit IC, which forms part of the audio device, is connected to the speaker SP via COMP/WR. Note that R1 and R2 are resistors.

In this configuration, the human body 6 is connected to one mirror piece 2
The operation when moving across the extended plane of 06 will be explained using the operation explanatory diagram in Figure 4, the pyroelectric infrared detection element output waveform diagram in Figure 5a, and the FET output waveform diagram in Figure 5b. do. When a human body emitting heat rays, that is, infrared rays, arrives at region 1 from a relatively far distance, the first pyroelectric infrared detection element 251a and the second pyroelectric infrared detection element 251a disposed at a distance d from the first pyroelectric infrared detection element 251a are detected. Although infrared rays are incident on the element 251b, the differential output is not output to the FET. Next, area 2 as the first detection zone by shielding and reflection.
In the first pyroelectric infrared detection element 251a, the mirror piece 206 acts to reflect infrared rays, project the infrared rays, make them incident, and add them to the directly incident infrared rays; 251b
It blocks infrared rays and obtains a large differential output. Furthermore, when the human body comes to region 3, the infrared rays enter both pyroelectric infrared detection elements 251a and 251b without being affected by the mirror piece 206.
No differential output appears. Furthermore, in region 4 as a second detection zone due to shielding and reflection, the mirror piece 206 is connected to the first pyroelectric infrared detection element 251a.
The second pyroelectric infrared detection element 251b has the function of blocking infrared rays, and causing the infrared rays to be reflected, projected, and incident on the second pyroelectric infrared detection element 251b, and added to the directly incident infrared rays, thereby obtaining a large differential output. In region 5, infrared rays are incident on both pyroelectric infrared detection elements 251a and 251b, and no differential output appears. The above explanation assumes that infrared rays are emitted from a single point, and ignores the fact that infrared rays attenuate in inverse proportion to the square of the distance, but in reality, objects to be detected spread over a certain width. It should be noted that it may be necessary to take into account the width and the difference in distance between the first and second pyroelectric infrared detection elements 251a and 251b to the object to be detected.

When the human body 6 emitting infrared rays comes to the outstanding zone of the pyroelectric infrared detection device, the infrared rays are detected by the pyroelectric infrared detection elements 251a and 251b, and the impedance is converted by the FET to obtain a differential output. The detection signal which is the differential output is, for example, about 1 mV when the distance to the human body is about 1 m, and is amplified to a level of several volts by the amplifier AMP. The output of the amplifier AMP is centered at a suitable bias potential. comparator
COMP sets a threshold slightly above or slightly below the bias potential, and outputs an ON signal when a detection signal exceeds the threshold.

Since the detection signal follows the detailed movement of the object to be detected, the output of the comparator also has multiple ON and OFF signals.
Sometimes the signals are continuous. The output of the comparator is passed through the waveform shaping circuit WR, and multiple consecutive ON/OFF signals are also collected as one detection and output. Comparator/waveform shaping circuit
The signal processed into a square wave by COMP/WR is
Input to the trigger terminal of the speech synthesis integrated circuit IC.
When a detection signal is input to the trigger terminal of the voice synthesis integrated circuit IC, a specified message is sent to the speaker.
Output by SP.

FIG. 6 shows a second embodiment of the pyroelectric infrared detection device used in this notification device. pin 604 and
FET circuit 605 and pyroelectric infrared detection element 60
A substrate 607 on which 6a and 606b are formed is supported by the pin 604 and placed in the center of the case 602. Furthermore, a mirror piece 608 is provided on the bottom portion 603 and is perpendicular to the plane on which the pyroelectric infrared detection elements 606a and 606b are formed. The mirror piece 608 is a rectangular member with a substantially semicircular bottom center portion,
Its extended surface is the pyroelectric infrared detection element 606a, 6
06b. The surface is mirror-finished, and the first reflective surface 60
The infrared rays reflected by 8a enter the first pyroelectric infrared detection element 606a, and the infrared rays reflected by the second reflective surface 608b enter the second pyroelectric infrared detection element 606a.
06b. Further, the pyroelectric infrared detection device 601 has a cylindrical cover 609 that constitutes a part of the case 602.
9 has an opening 610 in the end face, and the opening 6
10 is covered with an optical filter 611 made of a material that transmits infrared rays, a cover 609 is fitted to the periphery of the bottom 603, an inert gas such as nitrogen gas N ₂ is filled inside, and it is sealed by welding or the like. In this configuration, there is only one mirror piece 608, but the operation is similar to that of FIG. 2.

FIG. 7 is a perspective view showing a third embodiment of the pyroelectric infrared detection device used in this notification device, in which six mirror pieces 708 are the pyroelectric infrared detection elements 706.
a and 706b at equal intervals (60 degrees), and as in the first embodiment, the interval between the mirror pieces 708 is narrowed to increase the number of detection areas, and the mirror pieces 708 are made smaller. , the pyroelectric infrared detection device 701 is miniaturized to the same size as the pyroelectric infrared sensor of the first embodiment. The operation in this configuration is similar to that in FIG. 2, but since both are small, they can be installed directly on the notice board.

FIG. 8 shows a second example of the circuit used in this notification device, in which pyroelectric infrared detection elements 851a, 85
1b, field effect transistor FET, resistor R1,
Pyroelectric infrared sensor section consisting of R2, amplifier
Two-stage amplifier circuit D- with AMP1 and AMP2
AMP, comparator COMP with amplifiers AMP3 and AMP4, transistor Tr, audio recording and playback integrated circuit IC2, memory RAM, piezoelectric speaker
Equipped with SP and piezoelectric microphone MC.

The amplifier D-AMP is composed of a two-stage AC inverting amplifier.

The gain of the first stage amplifier is set by the input resistor R ₃ and the feedback resistor R ₇ , plus the capacitor
C ₂ and resistor R ₃ provide high-pass characteristics, capacitor C ₄ and resistor R ₇ provide low-pass characteristics, and the amplifier has band-pass characteristics.

The second stage amplifier also has a resistor _R8 and a resistor like the first stage.
_R12 sets the gain, capacitor _C5 and resistor _R8 provide high-pass characteristics, and capacitor _C7 and resistor _R12 provide low-pass characteristics.

The bandpass characteristic of the amplifier D-AMP is the combination of the bandpass characteristics of the first and second stage amplifiers, but this frequency range is adjusted to match the walking speed and movement speed of the human body to be detected. , 0.5Hz~
Set to 10Hz range.

The output of the amplifier D-AMP is the reference resistance R ₉ , R ₁₁
The output is centered around the bias potential set by .

In the embodiment of the notification device shown in FIG. 1, the backward movement direction of the human body coming in front of the notification device is
You are free to come from the left or the right. As can be seen from the operation diagram in Fig. 4 and the FET output waveform in Fig. 5b, when approaching the notification device in Fig. 1 from the left, the FET enters from area 1 to area 2 in Fig. 4.
A positive direction signal is output. Approaching from the right means entering from area 5 to area 4, and a negative direction signal is output.

The amplifier D-AMP performs two stages of inversion amplification, so if a human body approaches the notification device from the left, the same thing as described above will occur, and the output of the amplifier D-AMP will be a positive direction signal centered around the bias potential. is output. Furthermore, when approaching from the right, a negative direction signal is output.

The function of the notification device is to start a specified message a little before the device comes in front of the notification device to attract attention, so we connected a comparator COMP with thresholds set at appropriate potentials above and below the bias potential. , when approaching the notification device from the left, the comparator consisting of amplifier AMP3, whose threshold is set slightly above the bias potential of the output of amplifier D-AMP, turns ON and outputs the LOW signal OV. .

When approaching the notification device from the right, the comparator consisting of amplifier AMP4, whose threshold is set slightly below the bias potential of the output of amplifier D-AMP, turns on (ON), and the signal is LOW.
Output OV.

The threshold potential of the comparator is the resistance R ₁₃ ,
Set by R ₁₄ and R ₁₅ .

The PNP transistor Tr connected to the output terminal of the comparator is turned on by the base current flowing through the resistor _R21 in response to the LOW signal output from the comparator.

When the transistor is turned on in the audio recording/playback integrated circuit IC2 connected to the collector terminal of the transistor, a voltage is applied to the resistor _R22 , and playback starts and a message is generated from the piezoelectric speaker SP.

Note that R ₃ to R ₂₄ are resistors, and C ₁ to C ₉ are capacitors. A message is prerecorded in the voice recording/reproducing integrated circuit IC2 from the piezoelectric microphone MC.

<Effects of the Invention> The notification device of the present invention has been described in detail above, and produces the following effects.

The pyroelectric infrared detection device used in the notification device of the present invention does not use a relatively large condensing mirror, but instead places a plate-shaped mirror piece in front of a pair of pyroelectric infrared detection elements for reflection and shielding effects. Since it is highly sensitive and can be constructed in a small size, it is possible to obtain an electronic notice board that is unobtrusive even when formed integrally with the notice board and is very easy to use. Also,
By integrating with the notice board, it is possible to reliably send messages such as informational advertisements and advertisements when a human body approaches the notice board, which has the advantage of providing a highly reliable notice device, and in addition, when there are no passersby. Since it does not consume electricity, it has the advantage of saving energy.

[Brief explanation of the drawing]

FIG. 1 is an external front view of an embodiment of the device of the present invention;
FIG. 2a is a plan view of a first example of a pyroelectric infrared detection device used in the present invention, FIG. 2b is a side sectional view of the same, and FIG. 3 is a circuit diagram of the first example used in the present invention. Fig. 4 is an explanatory diagram of the operation, Fig. 5 a is a pyroelectric infrared detection element output waveform diagram, Fig. 5 b is an FET output waveform diagram, and Fig. 6 a is a pyroelectric infrared detector according to the second example used in the present invention. 6b is a plan view of the same, FIG. 7 is a perspective view of a third example of a pyroelectric infrared detector used in the present invention, and FIG. 8 is a second example of the pyroelectric infrared detector used in the present invention. FIG. 9 is a perspective view of a conventional pyroelectric infrared detection device. 1...Notification device, 2...Notification board, 3,601,
701...Pyroelectric infrared detection device, 4...Speaker, 5...Audio device, 251a, 251b, 60
6a, 606b, 706b...Pyroelectric infrared detection element, 206,608,708...Mirror piece.

Claims (1)

[Scope of claim for utility model registration] A notice board for displaying information or advertising;
In a notification device having a pyroelectric infrared detection device that detects infrared rays from a detected object and outputs a detection signal, and an audio device that generates a message, the pyroelectric infrared detection device includes a pair of pyroelectric infrared rays It is characterized in that it is composed of a detection element and a plate-shaped mirror piece disposed in front of the pair of pyroelectric infrared detection elements, and is disposed on a part of the surface of the notice board. Announcement device.