JPH06258137A - Pyroelectric infrared ray sensor - Google Patents

Abstract

PURPOSE:To increase temperature rise due to incidence of infrared rays and to increase sensitivity by allowing the part corresponding to the infrared ray reception part of a pyroelectric body substrate to be in non-contact state for a circuit substrate. CONSTITUTION:A plurality of infrared ray detection electrodes 21 are aligned in an array on a pyroelectric substrate 20. The substrate 20 is fixed on a circuit substrate 22 while it is floated by a plurality of leg stands 23, thus enabling the substrate 20 under the electrodes 21 to be isolated from the substrate 22 and causing the temperature of the electrodes 21 to increase easily due to infrared rays. The lead wire of the electrodes 21 penetrates the substrate 20 in lower direction, is wired on the leg stand 23 along the lower surface, and then is connected to the substrate 22 through it. Also, the leg stand 23 is formed by uniformly applying a paste with a solid conductive filler (50-100mum). The substrate 20 is mounted on it and is burnt collectively, thus controlling the gap between the substrates 22 and 20 with improved accuracy.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pyroelectric infrared sensor, a temperature distribution measuring device using the same, and the like.

[0002]

2. Description of the Related Art In recent years, in security and air conditioning control, there is an increasing demand for measuring the temperature distribution in a room in order to detect the presence or absence of a person in the room and the amount of activity.

Conventionally, there are two types of devices for measuring the temperature distribution in space using infrared rays. One of them is a method of obtaining a temperature distribution using a two-dimensional quantum solid-state imaging infrared sensor. The other is a method of obtaining a spatial temperature distribution using a pyroelectric sensor, which is disclosed in, for example, Japanese Patent Laid-Open No. 64-8839.
1, JP-A-57-185695, JP-A-2-18375
2. As described in JP-A-2-196932 and the like, a single pyroelectric sensor is used to mechanically scan in the vertical and horizontal directions to detect the input energy in each direction and obtain the temperature distribution. Is the way.

[0004]

However, in the case of the former quantum type solid-state imaging infrared sensor, the measurement temperature accuracy and resolution are high, but since the sensor portion needs to be cooled, it becomes expensive, and it becomes difficult to use it for household appliances. There is a problem that it is not suitable for use.

On the other hand, the latter one using the pyroelectric sensor is
Due to the problem of low sensor sensitivity, the complexity of the mechanism, and the complexity of signal processing, there is a problem of low spatial resolution and temperature resolution.

An object of the present invention is to provide a pyroelectric infrared sensor having advantages such as low cost, small size, and high sensitivity in consideration of the problems of the conventional sensor.

[0007]

SUMMARY OF THE INVENTION The present invention is directed to a pyroelectric substrate having a plurality of pyroelectric infrared detectors arranged in an array,
A portion corresponding to the infrared light receiving portion is a pyroelectric infrared sensor that is in a non-contact state with the circuit board.

The present invention further provides an FE on a circuit board.
This is a pyroelectric infrared sensor in which T and a resistor are mounted and integrated.

Further, the present invention provides a temperature distribution measuring device having a chopping section for intermittently blocking infrared rays entering the infrared detecting section and a rotating section for continuously rotating the infrared detecting section. Is.

Further, according to the present invention, the number of persons in the room is determined based on such a temperature distribution measuring device arranged in the room and the radiation temperature distribution measured value and / or the time-dependent change value output from the temperature distribution measuring device. A human body detection system including a human body detection device that determines the position, or the activity amount of an occupant.

[0011]

In the present invention, since the portion of the pyroelectric substrate corresponding to the infrared ray receiving portion is not in contact with the circuit substrate, the temperature easily rises and the sensitivity is improved.

The present invention further provides an FE on the circuit board.
Since the T and the resistor are mounted and integrated, the noise and the sensitivity are improved.

Further, since the present invention is provided with a chopping section for intermittently blocking the infrared rays incident on such an infrared detecting section and a rotating section for continuously rotating the infrared detecting section, it is possible to measure the temperature. It can be realized with higher sensitivity.

Further, according to the present invention, the temperature distribution measuring device measures the temperature distribution in the room, and based on the radiation temperature distribution measured value and / or the time-dependent change value found as a result, the number of persons in the room, the position, or the presence of the room The amount of activity of the person.

[0015]

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

FIG. 1 and FIG. 2 are views showing a schematic structure of a temperature distribution measuring apparatus according to an embodiment of the present invention, in which a sensor rotating unit 3 is used.
Is provided with an infrared array sensor 1 in which a plurality of pyroelectric infrared detectors are provided in an array, and an infrared lens 2 for condensing infrared rays on the front surface of the infrared array sensor 1, and further, A chopper 4 having a chopper window portion 11 for intermittently blocking infrared rays incident on the infrared lens 2 is provided on the incident side. The chopper 4 is provided with a chopper rotating inscribed gear part 8, and an output gear 6 directly connected to the motor 5 via a chopper gear 7.
Mechanically connected to. Further, a sensor rotation internal gear portion 10 is provided inside the downward flange portion of the sensor rotation portion 3 and is mechanically connected to the sensor rotation gear 9. The sensor rotation gear 9 is coaxial and integrated with the chopper gear 7.

FIG. 3 shows a perspective view of the chopper 4. The chopper 4 shown in the figure opens and closes twice in one rotation, but if the opening is set to N locations, the chopper can be performed N times.

FIG. 4 is a partially cutaway perspective view of a measuring device having a structure similar to that of the temperature distribution measuring device of FIGS. 1, 2 and 3 described above, and shows a schematic structure thereof.

Now, when the motor 5 is driven with the long-axis direction of the infrared array sensor 1 installed vertically, the chopper 4 continuously rotates and intermittently blocks the infrared rays incident on the infrared lens 2. The distribution of the amount of radiant heat in the column in the direction in which the infrared lens 2 faces, that is, the temperature distribution can be measured. The measurable spatial range is determined by the angle of view of the lens and the sensor size.

Since the sensor rotation gear 9 is also rotated by the rotation of the motor 5, the sensor rotation unit 3 is also continuously rotated at a constant rotation angular velocity. That is, while the sensor rotation unit 3 is rotated forward to scan the direction in which the infrared array sensor 1 and the infrared lens 2 are facing, the chopper 4 is driven to measure the temperature distribution on the next surface.
After the measurement, by connecting the vertical temperature distributions in each direction by electrical signal processing, a two-dimensional inversion temperature distribution of space is obtained.

After the measurement of the final body surface direction is completed, the motor 5 is rotated in the reverse direction to return to the initial body surface direction, and a standby state for the next measurement is created.

The timing of fetching the chopping signal is determined by the position sensor 1 provided in the sensor rotation unit 3 in FIG.
8 and the sensitive plate 19 provided on the chopper 4 to estimate the relative chopping time. For example, the sensitive plate 19 may be a permanent magnet and the position sensor 18 may be a hall element, or the sensitive plate 19 may be a light reflecting plate and the position sensor 18 may be a photodiode and a phototransistor.
Is a photo interrupter, and the sensitive plate 19 may be a combination of thin plates. Furthermore, the time of each chopping may be inferred from the time elapsed from the start of measurement of the timing of signal acquisition of data processing.

FIG. 5 is a perspective view showing a pyroelectric infrared sensor of the present invention, in which (a) is the pyroelectric substrate and (b) is the same.
FIG. 4 is a diagram in which a pyroelectric substrate is mounted on a circuit board. That is, a plurality of infrared detection electrodes 21 are arranged in an array on the pyroelectric substrate 20. The pyroelectric substrate 20 is fixed to a circuit substrate 22 in a floating state by a plurality of legs (projections) 23. Therefore, the pyroelectric substrate portion under the electrode 21 is in a state of being separated from the circuit substrate 22. Therefore, the temperature of the electrode 21 is easily increased by infrared rays. The lead wire of the electrode 21 penetrates the pyroelectric substrate 20 in the downward direction, travels along the lower surface, is wired to the pedestal 23, and is connected to the circuit substrate 22 therethrough. The part corresponding to the pedestal 20 is manufactured as shown in FIG. As shown in (a), a plurality of solder protrusions 23 also serving as extraction electrodes are formed on the circuit board 22. A pyroelectric substrate 20 is placed on this, as shown in FIG.
The place of the solder protrusion 23 is enlarged and shown in (c). Further, a conductive paste (for example, a silver paste, a ruthenium oxide paste, a platinum paste, a gold paste, etc.) is applied to the joint between the solder protrusion 23 and the pyroelectric substrate 20. The height of the solder protrusion 23 is preferably 10 μm or more. The method using solder has an advantage that the manufacturing method is simple.

The pedestal 20 may be formed by swelling the conductive paste on the circuit board 22 by a screen printing method. It is easy to manufacture and has the advantages of mass production.

The base 20 may be formed by applying a fixed amount of paste containing a solid conductive filler (50 μm to 100 μm). Alternatively, a fixed amount of conductive paste containing a solid filler (50 μm to 100 μm) may be applied. The pyroelectric substrate 20 is placed on it and fired together. According to this method, the gap between the circuit board 22 and the pyroelectric substrate 20 can be controlled with high accuracy.

It is also possible to place the conductive paste on a transfer film and transfer it to the circuit board 22 by using it. According to this method, mass productivity is enhanced.

Further, as the material of the circuit board 22, a material such as glass epoxy or polyimide can be used.
It is also possible to form a window in the lower part of the pyroelectric substrate 20.

FIG. 7 is a view relating to another embodiment of the present invention. In FIG. 7A, the FET 26 and the resistor 27 are mounted on the circuit board 22 on the same surface as the pyroelectric board 20. It has been done. As a result, the lead electrode can be shortened, low noise, high sensitivity, the height of the can can be reduced only at the pyroelectric portion, and infrared rays incident on other than the light receiving electrode can be cut off. FIG. 2B shows the circuit support substrate 22 on the side where the pyroelectric substrate 20 is not mounted.
The FET 26 and the resistor 27 are mounted on the surface. As a result, in addition to the above advantages, further downsizing can be realized. FIG. 6C is a diagram in which such a circuit board 22 is mounted on a hermetic seal can.

The temperature measuring thermistor may be mounted on the circuit board 22.

The device shown in the above example was attached to the upper wall surface of a room of about 6 × 6 m, and the temperature distribution in the whole room was measured.
Note that the number of sensor light-receiving units was 10, and the number of left and right rotation steps was 30. The spatial temperature distribution at this time is 10
X30 matrix S00, 01, S00, 02, ---, S00, 10 S01, 01, S01, 02, ---, S01, 10 ----- --- --- --- --- It can be expressed by S30, 01, S30, 02, --- S30, 10. That is, if the number of sensor light receiving portions is n and the angle at which the sensor portion rotates in one open / close chopper is θ degrees, the data addresses are, for example, S01, S02,
---, S0n, data is stored for each step, the measurement is performed by rotating the direction forwards m times, and the data addresses at that time are Sm1, Sm2, ---, Smn. Therefore, it was possible to detect the presence or absence of persons in the room and the number of persons in the room by determining the distribution state of each measured temperature of 30 ° C. or higher. Here, it is difficult to discriminate between the case where there is one person near the measuring device and the case where there are a plurality of persons at one place in the distance, but it is difficult to distinguish with one measurement temperature distribution. Therefore, it was possible to determine empirically. Furthermore, the amount of activity of the occupants was able to be qualitatively determined.

By introducing the fuzzy reasoning using the membership function for the above judgment, more accurate judgment was possible.

Needless to say, the drive source of the present invention is not limited to the motor.

Further, the protrusion of the present invention may be formed by a method other than the above embodiment.

[0034]

As is apparent from the above description,
According to the present invention, since the portion of the pyroelectric substrate on which a plurality of pyroelectric infrared detecting portions is provided in an array shape, which corresponds to the infrared light receiving portion, is in a non-contact state with the circuit board, it is possible to use infrared rays. Greater temperature rise and better sensitivity.

Further, from the information of this device, the position of the person in the room,
Since the number of people, the amount of activity, etc. can be easily known, the security system and the like can be operated reliably.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a temperature distribution measuring device according to an embodiment of the present invention.

FIG. 2 is a diagram showing a relative positional relationship of gear parts of a temperature distribution measuring device according to an embodiment of the present invention.

FIG. 3 is a perspective view of a chopper of a temperature distribution measuring device according to an embodiment of the present invention.

FIG. 4 is a partially cutaway perspective view of a temperature distribution measuring device according to an embodiment of the present invention.

FIG. 5 is a perspective view of an infrared sensor according to an embodiment of the present invention.

FIG. 6 is a perspective view illustrating an infrared sensor manufacturing process according to an embodiment of the present invention.

FIG. 7 is a perspective view of an infrared sensor according to another embodiment of the present invention.

[Explanation of symbols]

 1 Infrared Array Sensor 2 Infrared Lens 3 Sensor Rotating Unit 4 Chopper 5 Motor 6 Output Gear 7 Chopper Gear 8 Chopper Rotating Internal Gear 9 Sensor Rotating Gear 10 Sensor Rotating Internal Gear 11 Chopper Window 20 Pyroelectric substrate 21 Detection electrode 22 Circuit board 23 Leg stand (projection) 26 FET 27 Resistance

Claims (11)

[Claims] 1. A portion of a pyroelectric substrate on which a plurality of pyroelectric infrared detectors are provided in an array, corresponding to an infrared light receiving portion, with respect to a circuit substrate for supporting the pyroelectric substrate. A pyroelectric infrared sensor characterized by being in a non-contact state. 2. The protrusion formed on the circuit board,
The pyroelectric infrared sensor according to claim 1, wherein the non-contact state is created. 3. The protrusions are formed by a method of soldering, printing a conductive paste, applying a paste containing a solid conductive filler, applying a conductive paste containing a solid filler, or transferring the conductive paste. The pyroelectric infrared sensor according to claim 2, wherein the pyroelectric infrared sensor is one. 4. The pyroelectric infrared sensor according to claim 1, wherein a window is formed on the circuit board. 5. The pyroelectric infrared sensor according to claim 1, wherein the FET and the resistor are mounted and integrated on the circuit board. 6. The pyroelectric infrared ray according to claim 5, wherein the FET and the resistor are mounted and integrated on a surface of a circuit board on which the pyroelectric board is mounted. Sensor. 7. The FET and the resistor are mounted and integrated on a surface of the circuit board opposite to the surface on which the pyroelectric substrate is mounted. The described pyroelectric infrared sensor. 8. The pyroelectric infrared sensor according to claim 1, wherein a thermistor for temperature measurement is mounted and integrated on the circuit board. 9. The pyroelectric infrared sensor according to claim 1, which is mounted on a hermetic seal can. 10. The device further comprises a chopping unit for intermittently blocking infrared rays incident on the infrared detection unit, and a rotating unit for continuously rotating the infrared detection unit. The temperature distribution measuring device according to 1 or 5. 11. The temperature distribution measuring device according to claim 10 arranged in a room, and the number and position of persons in the room based on the radiation temperature distribution measured value and / or the time-dependent change value output from the temperature distribution measuring device. Alternatively, a human body detection system comprising a human body detection device that determines the amount of activity of a person in the room.