KR890008291Y1 - Distinctive circuit using intensity - Google Patents

Abstract

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Description

Human Body Access Discrimination Circuit Using Pyroelectric Infrared Sensor

The accompanying drawings are a human body approach discrimination circuit diagram of the present invention.

* Explanation of symbols for main parts of the drawings

1: human body approach detection unit 2: human back detection unit

3, 4: low pass filter 5, 6: amplifier

S ₁ -S ₄ : Pyroelectric infrared sensor COM ₁ , COM ₂ : Comparator

MM ₁ : Monomulti FF ₁ : Flip-flop

The present invention relates to a human body access discrimination circuit using a pyroelectric infrared sensor to determine the approach of the human body, and in particular, a pyroelectric infrared sensor that determines whether the human body approaches within the sensing range and also moves out of the sensing range. It relates to a human body approach discrimination circuit using.

Conventionally, when determining whether the human body is approached by using an infrared sensor, since an infrared sensor is used, there is a defect that cannot be determined whether the human body approaches or remains or moves and disappears.

The present invention, in view of such a conventional defect, by using a polarization phenomenon according to their temperature cotton with a pyroelectric infrared sensor to form an electrode on the front and back, connecting the resistance to the electrode between the both ends of the resistance according to the human approach The voltage fluctuations of the human body as well as the approach of the human body to determine what has been passed.

First, the infrared sensor will be described. The infrared sensor is classified into a thermal type that senses using a phenomenon in which the temperature of a substance changes when it absorbs energy and a quantum type that is directly detected by a photon. A thermal infrared sensor has a flat wavelength characteristic However, there is a defect that the response temperature is low and the response speed is slow.

In addition, a pyroelectric infrared sensor has been developed to compensate for the above defects. Unlike general semiconductor sensors, a pyroelectric infrared sensor has no wavelength dependence on room temperature operation and sensitivity, and is combined with various kinds of spectral transmissive materials. By making a sensor suitable for the purpose of use, as well as easy operation and low cost, the present invention is to determine the approach and disappearance of the human body using such a pyroelectric infrared sensor.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

As shown in the accompanying drawings, a pyroelectric infrared sensor (S ₁ , S ₂ ), (S ₃ , S ₄ ) and field effect transistors (FET ₁ ), (FET ₂ ), respectively detecting the approach and withdrawal of the human body, Low-pass in the output signal of the human body approach and human body sense detection unit (1) (2) and the human body approach and human body sense detection unit (1) (2) of the resistors (R ₁ , R ₂ ), (R ₃ , R ₄ ) Resistor (R _5- R ₈ ) (R _9- R ₁₂ ) and capacitor (C ₁ , C ₂ ) (C ₃ , C ₄ ) that pass the signal. A low pass filter (3) (4) consisting of an operational amplifier (OP ₁ ) (OP ₂ ), and resistors (R ₁₃ , R ₁₄ ) and (R) for amplifying the output signal of the low pass filter (3) (4); ₁₅ , R ₁₆ and operational amplifiers OP ₃ and OP ₄ and the output signals of the amplifiers 5 and 6 compare the reference voltage Vref ₁ (Vref ₂ ). A comparator (COM ₁ ) (COM ₂ ), a mono multi (MM ₁ ) for outputting a pulse signal according to the output signal of the comparator (COM ₁ ), and the comparator according to the output signal of the mono multi (MM ₁ ). It is composed of a flip-flop FF ₁ that outputs the signal of (COM ₁ ) and is cleared in accordance with the output signal of the comparator (COM ₂ ).

Referring to the effect of the present invention configured in this way in detail as follows.

When the human body approaches within the detection range of the pyroelectric infrared sensors (S ₁ , S ₂ ) (S ₃ , S ₄ ) while power is applied to the power supply terminal (Vcc), the pyroelectric infrared sensors (S ₁ , S ₂ ) Since (S ₃ , S ₄ ) generates a constant voltage and is applied to the gates of the field effect transistors FET ₁ and FET ₂ , the field effect transistors FET ₁ and FET ₂ are turned on to supply power to the power supply terminal Vcc. Through this field effect transistor (FET ₁ ) (FET ₂ ), the noise signal is removed through the low pass filter (3) (4), and amplified by the amplifier (5) (6) and the comparator (COM ₁ ) ( COM ₂ ) is applied to the non-inverting input terminal (+) and the inverting input terminal (-), respectively.

Here, when the pyroelectric infrared sensor (S ₁ , S ₂ ) (S ₃ , S ₄ ) detects the human body, if the output voltage of the amplifier (5) 6 is higher than the reference voltage (Vref ₁ ) (Vref ₂ ) a comparator is the low potential is output at (COM ₂₎ so applied to the clear terminal (CLR) of flip-flop (FF ₁₎ flip-flop (FF ₁₎ is not cleared, the comparator (COM ₁₎ by outputting the high potential flip It is applied to the input terminal D of the flop FF ₁ and to the monomulti MM ₁ .

Therefore, since the mono multi MM ₁ outputs a pulse signal and is applied to the clock terminal CLK of the flip-flop FF ₁ , the flip-flop FF ₁ is output terminal by the high potential applied to its input terminal D. The high potential is output as (Q) to indicate that the human body is approaching.

In this state, when the approaching object recedes, the pyroelectric infrared sensors S ₁ , S ₂ , S ₃ , and S ₄ output low potentials, and the field effect transistors FET ₁ and FET ₂ are reversed. the so-off low-pass filter (3) (4) outputs a low potential, an amplifier (5) and (6) a non-inverting input terminal (+) of the comparator (COM ₁₎ (COM ₂₎ outputs a low potential, and It is applied to the inverting input terminal (-).

Therefore, the comparator (COM ₁₎ outputs a low potential, the comparator (COM ₂₎ are so applied to the clear terminal (CLK) of the flip-flop (FF ₁₎ and outputting the high potential flip-flop (FF ₁₎ is clear his Output low potential to output terminal (Q).

As described above, the present invention detects the approach and withdrawal of the human body with a pyroelectric infrared sensor, and thus, the operation is very smooth and the effect of accurately determining the approach and withdrawal of the human body is obtained.

Claims (1)

Human body approach and retreat detection unit (1) (2) and the human body approach and human back sense detection unit (1) for detecting the approach and retreat of the human body with pyroelectric infrared sensors (S ₁ , S ₂ ) (S ₃ , S ₄ ) A low pass filter (3) (4) for passing only the low pass signal in the output signal of (2) and a signal output from the low pass filter (3) (4) and amplified by the amplifier (5) (6) are referred to as reference voltages. A comparator (COM ₁ ) (COM ₂ ) comparing with (Vref ₁ ) (Vref ₂ ), a monomulti (MM ₁ ) for outputting a pulse signal according to the output signal of the comparator (COM ₁ ), and the monomulti ( MM ₁ ) A pyroelectric infrared sensor comprising a flip-flop FF ₁ that outputs a signal of the comparator COM ₁ according to an output signal of the comparator and is cleared according to the output signal of the comparator COM ₂ . Human body access discrimination circuit.