JP2013246148A - Floating fine particle sensing device and smoke sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a floating fine particle sensing device and a smoke sensor which can discriminate floating fine particles from foreign substances which are not floating fine particles and sense them respectively.SOLUTION: A floating fine particle sensing device is provided with: a chamber 10 for receiving flow-in of floating fine particles from outside and blocking disturbance light from outside; a pair of first light receiving and emitting parts (11, 12) which are placed in the chamber 10 and sense floating fine particles flown in the chamber 10; and second light receiving and emitting parts (21, 22) which are placed in the chamber 10 and sense foreign substances different from floating fine particles in a second sensing region on the bottom side to a first sensing region where the floating fine particles are sensed by the first light receiving and emitting parts (11, 12).

Description

  The present invention relates to a suspended particle sensing device and a smoke detector, and includes a light emitting element that irradiates light to a sensing space, and a light receiving element that receives scattered light caused by suspended particles out of the light emitted from the light emitting element. The present invention relates to a photoelectric floating particle detector and a smoke detector including the same.

  As shown in FIG. 9, in a general light scattering type floating particle sensing device, a pair of light emitting elements 711 and light receiving elements 712 are disposed in a chamber 710 that forms a space having a labyrinth structure, and irradiation of the light emitting elements 711 is performed. The light to be reflected is reflected in the chamber 710 and is not directly irradiated to the light receiving element 712. In the above-described suspended particle sensing device, when suspended particles enter a portion where the optical axis of the light emitting element 711 and the optical axis of the light receiving element 712 intersect (polymerize), the light irradiated from the light emitting element 711 is scattered to the suspended particles. Thus, the scattered light is detected by the light receiving element 712.

  In this floating particle sensing device, a control circuit board 740 is provided outside the chamber 710, and the operations of the light emitting element 711 and the light receiving element 712 are controlled by the control circuit board 740. Further, an amplifier circuit 713 is connected to the light receiving element 712, and the signal from the light receiving element 712 is amplified to a detectable signal level. When the output signal of the amplification circuit 713 input to the microcomputer 730 is equal to or higher than the determination level stored in the microcomputer 730, the microcomputer 730 determines that airborne particles have entered and outputs an alarm sound or the like. The chamber 710 is devised so as to allow the inflow of suspended particulates and prevent foreign matters such as dust from entering.

  As a conventional light scattering type floating particle sensing device, there is one having a configuration as shown in FIG. 10 (see, for example, JP 2011-102710 A (Patent Document 1)). This floating particulate sensor has a structure in which a pair of light emitting elements 811 and a light receiving element 812 are arranged in a sensing space in a chamber 810 so that light emitted from the light emitting element 811 is reflected in the chamber 810 and is not directly irradiated to the light receiving element 812. I am doing. In addition, in the floating particle sensing device, when the fine particles enter the portion where the optical axis of the light emitting element 811 and the optical axis of the light receiving element 812 intersect (polymerize), the light irradiated from the light emitting element 811 is scattered. Thus, the scattered light is detected by the light receiving element 812.

  FIG. 11 shows a schematic cross-sectional view of the chamber 810 viewed from the XI-XI line shown in FIG. As shown in FIG. 11, the light emitted from the light emitting element 811 is scattered by the floating fine particles when the fine particles enter the sensing region where the irradiation light of the light emitting element 811 and the light receiving area of the light receiving element 812 overlap. Light enters the light receiving element 811. The airborne particle sensing device senses the concentration of airborne particles by obtaining a signal proportional to the intrusion amount of airborne particles based on the intensity of incident scattered light.

JP 2011-102710 A

  A device using such a suspended particle sensing device is a consumer device such as an air purifier or a smoke sensor, and is used in a general home environment. In a general home environment, light may scatter and malfunction due to intrusion of large dust, infestation of insects such as ticks and fleas, and adhesion of water droplets to the chamber bottom surface 810a due to dew condensation in addition to the invasion of airborne particles. Therefore, the chamber 810 is designed so that the sensing region S801 where the irradiation light of the light emitting element 811 and the light receivable area of the light receiving element 812 overlap is placed above the chamber bottom surface 810a.

  However, foreign matter 820 such as dust deposited on the chamber bottom surface 810a of the floating particle sensing device may enter the sensing region S801 when it diffuses due to the invasion of airflow. Therefore, there is a problem that the foreign particles 820 are detected and malfunctions even though the suspended fine particles have not entered.

  In such a case, the smoke detector equipped with the above-mentioned suspended particulate detector malfunctions to determine that it is not a fire but a fire, and this is a big problem for the user or the residents in the vicinity of the user. It often happens.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a suspended particulate detector and a smoke detector that can identify and sense suspended particulates and foreign matters that are not suspended particulates.

In order to solve the above problems, the suspended particulate sensing device of the present invention is:
A housing part that allows airborne particulates from the outside to flow in and blocks external light from the outside;
A pair of first light emitting and receiving parts that are disposed in the housing part and detect the suspended fine particles flowing into the housing part;
A second detector that is disposed in the housing portion and detects a foreign substance different from the suspended particulates in a second sensing region located on the bottom side of the first sensing region where the suspended particulates are detected by the first light emitting and receiving unit. And a light emitting / receiving unit.

  According to the above configuration, the light from the light emitting elements of the pair of first light emitting and receiving parts disposed in the housing part is irradiated and scattered on the suspended fine particles flowing from the outside into the first sensing region in the housing part, By detecting the scattered light from the suspended fine particles with the light receiving elements of the pair of first light receiving and emitting units, the suspended fine particles can be sensed. On the other hand, the light from the light emitting element of the second light emitting / receiving unit arranged in the housing part is different from the suspended particles in the second sensing area on the bottom side of the first sensing area in the housing part (dust, mite, etc.). And the like, and the light inside the housing part can be sensed by detecting the scattered light from the foreign matter with the light receiving element of the second light emitting / receiving part. Therefore, it is possible to identify and detect suspended particles and foreign particles that are not suspended particles.

In addition, in the suspended particle sensing device of one embodiment,
The first and second light emitting / receiving units share either the light receiving element or the light emitting element.

  According to the above embodiment, since the first and second light receiving and emitting units share the light receiving element, the light receiving element is configured as one, and thus the amplifier circuit connected to the light receiving element can be configured as one. , Parts costs can be reduced. Alternatively, since the first and second light emitting / receiving units share the light emitting element, the current consumption associated with driving the light emitting element can be reduced, and the drive circuit connected to the light emitting element can be configured as a single component. Cost can be reduced.

In addition, in the suspended particle sensing device of one embodiment,
When the first and second light receiving and emitting units share the light receiving element, the light receiving element has two light receiving chips for a common lens,
When the first and second light emitting / receiving units share the light emitting element, the light emitting element has two light emitting chips for a common lens.

  According to the embodiment, by using a light receiving element having two light receiving chips for a common lens, reflected light in different ranges can be received by one light receiving element, and the size of the housing portion can be reduced. Is possible. Alternatively, by using a light emitting element having two light emitting chips for a common lens, two light axes can be irradiated from one light emitting element 311, and the size of the housing portion can be reduced.

In addition, in the suspended particle sensing device of one embodiment,
When the first and second light receiving and emitting units share the light receiving element, the light receiving element has one light receiving chip in which two light receiving regions are formed on the same semiconductor substrate.

  According to the embodiment, by using a light receiving element having one light receiving chip in which two light receiving regions are formed on the same semiconductor substrate, it is possible to reduce the number of components of the light receiving element and reduce the manufacturing cost of the light receiving element. it can.

In the smoke detector of the present invention,
Any one of the above suspended particulate sensing devices;
Warning means for warning that the foreign matter has been detected based on a detection signal from the second light emitting / receiving unit of the floating particulate sensor.

  According to the above configuration, the foreign substance in the second sensing region in the housing part is sensed by the second light emitting / receiving part of the suspended particulate sensing device, and the warning means, for example, based on the sensing signal from the second light emitting / receiving part By warning the user that a foreign object has been detected using sound such as display or sound, the user is informed that the foreign object has accumulated in the housing. Thereby, it becomes possible for the user to remove the foreign matter in the housing portion, thereby preventing a malfunction in which the foreign matter is detected and a fire is detected even though the suspended fine particles have not entered.

  As can be seen from the above, according to the present invention, it is possible to realize a suspended particulate detector capable of discriminating and sensing suspended particulates and foreign matters that are not suspended particulates, and a smoke detector using the same.

FIG. 1 is a schematic view of a suspended particulate sensor according to a first embodiment of the present invention. FIG. 2 is a schematic diagram showing a cross-sectional structure of a chamber of the suspended particulate sensor. FIG. 3 is a schematic diagram showing a cross-sectional structure of a chamber of a suspended particulate sensor according to a second embodiment of the present invention. FIG. 4 is a schematic diagram showing a cross-sectional structure of a chamber of a suspended particulate sensor according to a third embodiment of the present invention. FIG. 5 is a diagram showing the configuration of the light emitting element of the suspended particulate sensor according to the fourth embodiment of the present invention. FIG. 6 is a diagram showing the configuration of the light receiving element of the floating particulate sensor according to the fifth embodiment of the present invention. FIG. 7 is a diagram showing a configuration of a main part of the light receiving element. FIG. 8 is a view showing the configuration of the main part of the light receiving element of the suspended particle sensing device according to the sixth embodiment of the present invention. FIG. 9 is a diagram showing a schematic configuration of a general airborne particle sensing device. FIG. 10 is a diagram showing the structure of a conventional suspended particle sensing device. FIG. 11 is a schematic diagram showing a cross-sectional structure of the chamber of the suspended particulate sensor as viewed from the line XI-XI in FIG. FIG. 12 is a diagram showing a configuration of a light receiving element of a conventional suspended particle sensing device.

  DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a suspended particulate detector and a smoke detector according to the present invention will be described in detail with reference to the illustrated embodiments.

[First Embodiment]
FIG. 1 shows a schematic diagram of a suspended particulate sensor according to a first embodiment of the present invention.

  As shown in FIG. 1, the airborne particle sensing device according to the first embodiment includes a chamber 10 as an example of a housing part that allows inflow of airborne particulates from the outside and blocks external disturbance light. . In the chamber 10, there are arranged a light emitting element 11 and a light receiving element 12 for sensing suspended fine particles, and a light emitting element 21 and a light receiving element 22 for sensing the state of the chamber bottom 10a. In addition, the floating particle sensing device includes amplification circuits 13 and 23 that amplify the signals of the light receiving elements 12 and 22 by current-voltage conversion, drive circuits 14 and 24 of the light emitting elements 11 and 21, and overall operation. A control circuit board 40 including a microcomputer 30 that performs control and signal processing is provided.

  The light emitting element 11 and the light receiving element 12 constitute a first light receiving / emitting part, and the light emitting element 21 and the light receiving element 22 constitute a second light receiving / emitting part.

  FIG. 2 shows a cross-sectional structure of the chamber 10 provided in the suspended particle sensing device.

  As shown in FIG. 2A, the range in which the conical irradiation light of the light emitting element 11 disposed in the center of the cross section of the chamber 10 and the conical light-receiving area of the light receiving element 12 overlap is detected to detect suspended fine particles. It becomes area S1. Since the state of the chamber bottom surface 10a changes due to foreign matter 20 (dust accumulation, insect intrusion, dew condensation, etc.), the chamber bottom surface 10a is designed not to be a sensing region S1 of floating particulates. However, when the foreign matter 20 enters more than expected due to the intrusion of the air current, the foreign matter 20 enters the sensing area S1 and causes a malfunction.

  As shown in FIG. 2B, the airborne particle sensing device includes a light emitting element 21 and a light receiving element 22 that sense the state of the chamber bottom surface 10a, and a conical irradiation light of the light emitting element 21 and a cone of the light receiving element 22. A range where the light-receiving areas overlap each other is a sensing region S2 for sensing the foreign object 20.

  By giving the microcomputer 30 (shown in FIG. 1) a signal indicating the state of the foreign matter 20 such as dust accumulated on the chamber bottom surface 10a, it is possible to determine the abnormal state of the chamber bottom surface 10a before causing a malfunction. .

[Second Embodiment]
FIG. 3 shows a cross-sectional structure of the chamber 110 of the suspended particulate sensor according to the second embodiment of the present invention.

  As shown in FIG. 3A, the chamber 110 includes two light emitting elements 111 and 121 for detecting suspended particulates and for detecting the bottom surface state of the chamber, and receives scattered light from the light emitted from the light emitting elements 111 and 121. One light receiving element 112 is provided.

  The light emitting element 111 and the light receiving element 112 constitute a first light receiving / emitting part, and the light emitting element 121 and the light receiving element 112 constitute a second light emitting / receiving part.

  The area where the conical irradiation light of the light emitting element 111 disposed in the center of the cross section of the chamber 110 and the conical light receiving area of the light receiving element 112 overlap becomes a sensing region S101 for sensing suspended particulates in the first embodiment. It is the same as the suspended particulate sensing device of the form.

  As shown in FIG. 3B, the airborne particle sensing device includes a light emitting element 121 that senses the state of the chamber bottom surface 110a, and a sensing area where the irradiation light of the light emitting element 111 and the light receivable area of the light receiving element 112 overlap. S102 is arranged so as to irradiate the chamber bottom surface 110a, and can obtain scattered light from foreign matter 120 such as dust deposited on the chamber bottom surface 110a. By sensing the light emission timings of the light emitting element 111 for detecting the suspended particles and the light emitting element 121 for detecting the bottom surface state of the chamber, a light receiving signal representing the state of the suspended particles and the bottom surface 110a of the chamber can be obtained by one light receiving element 112. Can do.

  In the airborne particle sensing device of the second embodiment, since the light receiving element is composed of one, the amplifier circuit connected to the light receiving element can be composed of one, and the component cost can be reduced.

[Third Embodiment]
FIG. 4 shows a cross-sectional structure of a chamber 210 as an example of a housing part provided in the suspended particle sensing device of the third embodiment of the present invention.

  As shown in FIG. 4 (A), the chamber 210 includes two light receiving elements 212 and 222 for detecting suspended particulates and detecting the bottom surface of the chamber, and one light emitting element 211 as a light source of the light receiving elements 212 and 222. It has.

  The light emitting element 211 and the light receiving element 212 constitute a first light receiving / emitting part, and the light emitting element 211 and the light receiving element 222 constitute a second light receiving / emitting part.

  The range where the conical irradiation light of the light emitting element 211 disposed in the center of the cross section of the chamber 10 and the conical light receiving area of the light receiving element 212 overlap is a sensing region S201 for sensing suspended particulates in the first embodiment. It is the same as the suspended particulate sensing device of the form.

  As shown in FIG. 4B, the floating particle sensing device of the third embodiment includes a light receiving element 222 that senses the state of the bottom surface 210a of the chamber separately from the light receiving element for sensing floating particles. The conceivable light receiving area of the light emitting element 211 and the sensing region S202 where the conical irradiation light of the light emitting element 211 overlaps are arranged so as to irradiate the chamber bottom surface 210a, and the scattered light from foreign matter 220 such as dust accumulated on the chamber bottom surface 210a. Can be obtained.

  In the suspended particle sensing device of the third embodiment, the signals of the suspended particle sensing light receiving element 212 and the chamber bottom surface sensing light receiving element 222 can be simultaneously obtained by the same light emission, and the light emitting element 211 is driven. Since the current consumption can be reduced and the drive circuit connected to the light emitting element can be configured by one, the component cost can be reduced.

[Fourth Embodiment]
FIG. 5 shows a light emitting element 311 provided in the suspended particulate sensor according to the fourth embodiment of the present invention. The floating particle sensing device of the fourth embodiment has the same configuration as the floating particle sensing device of the third embodiment except for the light emitting element, and FIG.

  As shown in FIG. 5, the light emitting element 311 of the airborne particle sensing device of the fourth embodiment has two light emitting chips 311a and 311b for airborne particle sensing and chamber bottom surface sensing, which are formed with the same lens 330. Is placed in the package. The light emitting chip 311a for detecting suspended particles is disposed on the optical axis passing horizontally through the center of the lens 330. The light emitting chip 311b for sensing the bottom surface state of the chamber is disposed above the optical axis passing through the center of the lens 330 so that the optical axis is bent toward the bottom surface by the lens 330 provided in the light emitting element 311.

  As described above, in the floating particle sensing device of the fourth embodiment, the light emitting chips 311a and 311b (semiconductor chips), which are light emitting diodes (LEDs) serving as light emitting sources, are molded resin molded into a lens shape. A packaged light emitting element 311 is used.

  By providing the two light emitting chips 311a and 311b in one light emitting element 311 as described above, light of two different optical axes can be irradiated from the single light emitting element 311 and the size of the chamber can be reduced. to enable.

[Fifth Embodiment]
FIG. 6 shows a light receiving element 412 provided in the suspended particulate sensor according to the fifth embodiment of the present invention. The floating particle sensing device of the fifth embodiment has the same configuration as the floating particle sensing device of the second embodiment except for the light receiving element, and FIG.

  As shown in FIG. 5, the light receiving element 412 of the floating particle sensing device of the fifth embodiment has two light receiving chips 412a and 412b for sensing the floating particle and sensing the bottom surface state of the chamber. Is placed in the package. The light receiving chip 412a for detecting floating particles is disposed on the optical axis passing horizontally through the center of the lens 430. The light receiving chip 412b for sensing the bottom surface state of the chamber is disposed above the optical axis passing through the center of the lens 430 on which reflected light from the direction of the bottom surface of the chamber provided in the light receiving element 412 is collected.

  As described above, in the floating particle sensing device of the fifth embodiment, the mold resin in which the light receiving chips 412a and 412b (semiconductor chips) which are photodiodes (PD) for photoelectric conversion are molded into a condensing lens shape. The light receiving element 412 packaged in (1) is used.

  By providing the two light receiving chips 412a and 412b in one light receiving element 412 as described above, the single light receiving element 412 can receive reflected light in different ranges, and the size of the chamber can be reduced. To do.

  FIG. 7 shows a configuration of a main part of the light receiving element 412 shown in FIG.

  As shown in FIG. 7, the light receiving element 412 includes a lead frame 500 having a rectangular die pad 501, lead terminals 502 connected to the die pad 501, and lead terminals 503 and 504 spaced apart from the die pad 501.

  Two light receiving chips 510 and 520 are arranged on the die pad 501 of the lead frame 500. The light receiving chips 510 and 520 have circular light receiving portions 510a and 520a. Further, the anode electrode pad 511 and the die pad 501 on the light receiving chip 510 are connected by wire bonding, and the cathode electrode pad 512 and the lead terminal 503 on the light receiving chip 510 are connected by wire bonding. Further, the anode electrode pad 521 on the light receiving chip 520 and the lead terminal 502 are connected by wire bonding, and the cathode electrode pad 522 on the light receiving chip 520 and the lead frame 504 are connected by wire bonding.

  FIG. 12 shows the structure of a conventional light receiving element for comparison. In FIG. 12, 1000 is a lead frame, 1001 is a die pad, 1010 is a light receiving chip, 1010a is a light receiving portion, 1011 is an anode electrode pad, and 1012 is a cathode. Electrode pads 1002 and 1003 are lead terminals.

[Sixth Embodiment]
FIG. 8 shows a main part of a light receiving element provided in the suspended particulate sensor according to the sixth embodiment of the present invention. The suspended particle sensing device of the sixth embodiment has the same configuration as the suspended particle sensing device of the second embodiment except for the light receiving element, and FIG.

  As shown in FIG. 8, the light receiving element of the floating particle sensing device of the sixth embodiment has a rectangular die pad 601, a lead 602 connected to the die pad 601, and leads 603 and 604 spaced from the die pad 601. A frame 600 is provided.

  One light receiving chip 610 is disposed on the die pad 601 of the lead frame 600. The light receiving chip 610 includes rectangular light receiving portions 610a and 610b. The first cathode electrode pad 611 on the light receiving chip 610 and the lead terminal 603 are connected by wire bonding, and the anode electrode pad 612 on the light receiving chip 610 and the lead terminal 602 are connected by wire bonding. Further, the second cathode electrode pad 613 on the light receiving chip 610 and the lead terminal 604 are connected by wire bonding.

  The light receiving element shown in FIG. 8 includes a light receiving chip 610 provided with two light receiving portions 610a and 610b for sensing floating particles and sensing the bottom surface state of the chamber on the same semiconductor substrate.

  In the suspended particle sensing device of the sixth embodiment, a light receiving element packaged with a mold resin in which a light receiving chip 610 (semiconductor chip) that is a photodiode (PD (Potential Divider Photodiode)) that performs photoelectric conversion is molded into a condensing lens shape. Use.

  Since the light receiving element for detecting the floating particulates and the chamber bottom surface state is composed of one light receiving chip 610 having two light receiving portions 610a and 610b on the same semiconductor substrate, the number of components of the light receiving element is reduced. The manufacturing cost of the light receiving element can be reduced.

  The light receiving units 610a and 610b of the light receiving element are the same as the light receiving element 412 shown in FIG. 6 of the floating particle detecting apparatus of the fifth embodiment, and the light receiving unit 610a for floating particle detection is the center of the lens provided in the light receiving element. It is placed on the optical axis that passes horizontally. On the other hand, the light receiving unit 610b for detecting the chamber bottom state is disposed above the optical axis passing through the center of the lens on which the reflected light from the chamber bottom direction provided in the light receiving element is collected.

  In the conventional suspended particle detector, when foreign matter or dust that may intrude is deposited on the bottom of the chamber of the sensing area, the accumulated dust rises due to the inflow of airflow or dust adheres to the sensing area. There was a possibility of causing a malfunction. In particular, when used in smoke detectors, the above-mentioned false detection may cause a serious trouble because an alarm sounds if it is not a fire but a fire.

  On the other hand, according to the suspended particle sensing devices of the first to sixth embodiments, by providing a function of sensing the bottom surface of the chamber, the intrusion of dust and insects that may cause false detections, Since adhesion or the like can be detected, detection of suspended particulates such as smoke can be detected without erroneous detection.

  Further, as in the suspended particle sensing device of the second and third embodiments, either one of the light emitting element and the light receiving element is additionally provided for sensing the bottom surface of the chamber, and one of the light emitting element and the light receiving element is provided. By sharing it for airborne particle detection and chamber bottom surface detection, the increase in the number of parts can be reduced.

  In addition, like the floating particle sensing device of the fourth embodiment, the light emitting element for sensing the bottom of the chamber can irradiate light of different optical axes by configuring two light emitting chips inside the same element. The light for sensing the bottom of the chamber can be irradiated without adding a light emitting element.

  Further, like the floating particle sensing device of the fifth embodiment, the light receiving element for sensing the bottom surface of the chamber comprises two light receiving chips in the same element, thereby scattering the floating particle sensing region and the chamber bottom sensing region. Light can be received, and light for sensing the bottom of the chamber can be received without adding a light receiving element.

  In addition, as in the suspended particle sensing device of the sixth embodiment, by including a light receiving chip having two light receiving units on the same semiconductor substrate, the suspended particle sensing region can be provided without two light receiving chips. Scattered light in the chamber bottom sensing area can be received.

  The smoke detector equipped with the airborne particle detector according to the second and third embodiments may malfunction by notifying the user by an alarm operation or lighting operation when the chamber bottom detection signal rises above a certain level. It can be prevented in advance.

  In the first to sixth embodiments, the smoke detector provided with the suspended particle sensing device has been described. However, the present invention is not limited to this, and the suspended particle sensing device of the present invention is applied to other devices such as an air purifier. Also good.

  Although specific embodiments of the present invention have been described, the present invention is not limited to the first to sixth embodiments, and can be implemented with various modifications within the scope of the present invention.

In addition, as this suspended particulate sensing device,
A chamber having a labyrinth structure that allows inflow of suspended particulates and prevents the entry of ambient light;
The chamber is mounted, and includes a circuit for mounting an amplification circuit for a signal output from the light receiving element, a signal processing and a control circuit for controlling the operation of the light emitting element, and a driving circuit for the light emitting element,
The chamber is
A first light emitting element disposed in the chamber and emitting light toward the suspended fine particles in the sensing region;
A second light emitting element that is disposed in the chamber and emits toward suspended fine particles, foreign matter, water droplets, and the like attached to the bottom of the chamber;
A first light receiving element disposed in the chamber and receiving scattered light scattered by suspended fine particles in the sensing region;
A second light receiving element that is disposed in the chamber and receives scattered light scattered by suspended fine particles, foreign matter, water droplets, and the like attached to the inside of the chamber;
A control circuit switches between a first light emitting element and a first light receiving element for sensing scattered light due to suspended fine particles, and a second light emitting element and a second light receiving element for sensing scattered light on the bottom surface of the chamber. It is also possible to detect the state of the bottom surface of the chamber.

  According to the above configuration, in addition to the first light-emitting element and the first light-receiving element for detecting suspended particulates disposed in the chamber, foreign matter accumulated on the bottom surface of the chamber, insects such as mites, and water droplets due to condensation are detected. By providing the second light emitting element and the second light receiving element, the state of the bottom surface of the chamber can be sensed. Further, the control circuit performs signal processing by switching the selection of the second light emitting element and the second light receiving element at the time of sensing the state of the first light emitting element, the first light receiving element, and the bottom surface of the chamber at the time of sensing the suspended particles. Thus, it is possible to detect the accumulation of foreign matters such as dust, the occurrence of condensation, and the entry of ticks and fleas before malfunction occurs.

In addition, as the suspended particulate sensing device of the present invention,
A chamber having a labyrinth structure that allows inflow of suspended particulates and prevents the entry of ambient light;
The chamber is mounted, and includes a circuit for mounting an amplification circuit for a signal output from the light receiving element, a signal processing and a control circuit for controlling the operation of the light emitting element, and a driving circuit for the light emitting element,
The chamber is
A first light emitting element disposed in the chamber and emitting light toward the suspended fine particles in the sensing region;
A second light emitting element that is disposed in the chamber and emits toward suspended fine particles, foreign matter, water droplets, and the like attached to the bottom of the chamber;
A light receiving element disposed in the chamber and receiving scattered light in the sensing region;
The first light emitting element for sensing scattered light caused by suspended fine particles and the second light emitting element for sensing scattered light on the bottom surface of the chamber are switched by a control circuit to sense the state of the bottom surface of the chamber. You may do it.

  According to the above configuration, in addition to the first light-emitting element and the light-receiving element for detecting suspended particulates arranged in the chamber, light irradiates foreign matter accumulated on the bottom surface of the chamber, insects such as ticks, and water droplets caused by condensation. By including the second light emitting element, it is possible to sense the state of the bottom surface of the chamber. In addition, by using a common light receiving element for sensing floating particles and sensing the state of the bottom surface of the chamber, it is possible to sense the state of the bottom surface of the chamber without adding an amplifier circuit connected to the light receiving element.

In addition, as the suspended particulate sensing device of the present invention,
A chamber having a labyrinth structure that allows inflow of suspended particulates and prevents the entry of ambient light;
The chamber is mounted, and includes a circuit for mounting an amplification circuit for a signal output from the light receiving element, a signal processing and a control circuit for controlling the operation of the light emitting element, and a driving circuit for the light emitting element,
The chamber is
A light emitting element disposed in the chamber and emitting light toward the sensing region;
A first light receiving element disposed in the chamber and receiving scattered light scattered by suspended fine particles in the sensing region;
A second light receiving element that is disposed in the chamber and receives scattered light scattered by suspended fine particles, foreign matter, water droplets, and the like attached to the inside of the chamber;
The first light receiving element for detecting scattered light caused by suspended fine particles and the second light receiving element for detecting scattered light on the bottom surface of the chamber are switched by a control circuit to detect the state of the bottom surface of the chamber. You may do it.

  According to the above configuration, in addition to the light-emitting element for detecting the suspended particles and the first light-receiving element disposed in the chamber, the light received by the foreign matter accumulated on the bottom surface of the chamber, insects such as ticks, and water droplets due to condensation is received. By providing the second light receiving element, it is possible to sense the state of the bottom surface of the chamber. In addition, the light-emitting element uses the same light-emitting element when sensing suspended particles and sensing the state of the bottom of the chamber, so that the same light emission as suspended particle sensing can be achieved without adding a drive circuit connected to the light-emitting element. It can be used to sense the state of the bottom of the chamber at the same time.

In addition, in the suspended particle sensing device of one embodiment,
In the suspended particle sensing device including the two light emitting elements and one light receiving element,
The two light emitting elements are constituted by one light emitting element in which two light emitting chips are arranged in the same package.

  According to the above embodiment, the light emitting element is a semiconductor chip that is a light emitting diode (LED) serving as a light emitting source and packaged with a mold resin molded into a lens shape. By providing the chip and the LED chip for detecting the bottom of the chamber, it is possible to irradiate light of two different optical axes with a single light emitting element. According to the above, even if a light emitting element for detecting the bottom surface of the chamber is not separately provided, the light emission for detecting the suspended particles and the light emitting for detecting the bottom surface of the chamber can be performed from the same light emitting element, and the chamber can be reduced.

In addition, in the suspended particle sensing device of one embodiment,
In the suspended particle sensing device including the one light emitting element and the two light receiving elements,
The two light receiving elements are constituted by one light receiving element in which two light receiving chips are arranged in the same package.

  According to the above embodiment, the light receiving element is a semiconductor chip that is a photodiode (PD) that performs photoelectric conversion and is packaged with a mold resin molded into a condensing lens shape. By providing the light receiving chip and the light receiving chip for detecting the bottom of the chamber, it is possible to receive light of two different optical axes with a single light receiving element. As described above, even if a light receiving element for sensing the bottom surface of the chamber is not separately provided, the same light receiving element can receive scattered light from the suspended fine particles and light scattered by the bottom surface of the chamber, thereby reducing the size of the chamber.

In addition, in the suspended particle sensing device of one embodiment,
In the suspended particle sensing device including the one light emitting element and the two light receiving elements,
The two light receiving elements are composed of one light receiving element in which two light receiving areas are formed on the same semiconductor substrate.

  According to the embodiment, the light receiving element is a semiconductor chip which is a photodiode (PD) for photoelectric conversion and packaged with a mold resin molded into a condensing lens shape, but the packaged photodiode is floating. By providing the light receiving part for detecting the fine particles and the light receiving part for detecting the bottom of the chamber on the same semiconductor chip, it is possible to receive light of two different optical axes with a single light receiving element. As described above, by providing different light receiving portions on the same chip, it is not necessary to separately provide different light receiving elements, and the chamber can be reduced.

As a smoke detector of the present invention,
Equipped with the above light scattering particle detector,
An alarm may be sounded in response to an increase in the received light signal of scattered light scattered by suspended fine particles, foreign matter, water droplets, etc. adhering to the inside of the chamber.

  According to the above configuration, the smoke detector using the above-described suspended particle detector can detect the state of the bottom surface of the chamber, which is the detection region, and sounds an alarm in response to a signal output for detecting the bottom surface of the chamber. It is possible to notify the accumulation of dust.

DESCRIPTION OF SYMBOLS 10,110,210 ... Chamber 10a, 110a, 210a ... Bottom of chamber 11, 21, 111, 121, 211, 311 ... Light emitting element 12, 22, 112, 122, 212, 222, 412 ... Light receiving element 13, 23 ... Amplification Circuits 14, 24 ... Drive circuit 20, 120 ... Foreign matter 30 ... Microcomputer 40 ... Control circuit board

Claims (5)

A housing part that allows airborne particulates from the outside to flow in and blocks external light from the outside;
A pair of first light emitting and receiving parts that are disposed in the housing part and detect the suspended fine particles flowing into the housing part;
A second detector that is disposed in the housing portion and detects a foreign substance different from the suspended particulates in a second sensing region located on the bottom side of the first sensing region where the suspended particulates are detected by the first light emitting and receiving unit. A suspended particle sensing device comprising: a light receiving and emitting unit. In the suspended particulate sensing device according to claim 1,
The first and second light emitting / receiving units share either a light receiving element or a light emitting element. In the suspended particulate sensing device according to claim 2,
When the first and second light receiving and emitting units share the light receiving element, the light receiving element has two light receiving chips for a common lens,
When the first and second light emitting / receiving units share the light emitting element, the light emitting element has two light emitting chips with respect to a common lens. In the suspended particulate sensing device according to claim 2,
When the first and second light receiving and emitting units share the light receiving element, the light receiving element has one light receiving chip in which two light receiving regions are formed on the same semiconductor substrate. apparatus. The suspended particle sensing device according to any one of claims 1 to 4,
A smoke detector, comprising: warning means for warning that the foreign object has been detected based on a detection signal from the second light emitting / receiving unit of the floating particulate sensor.

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