TWI725400B - Smoke detector - Google Patents

Abstract

無。

Description

Smoke sensor

The present invention relates generally to a smoke sensor, and more specifically, to a smoke sensor that senses smoke by receiving light output from a light-emitting element with a light-receiving element, and the light output from the light-emitting element flows into the sensor. The smoke of space is scattered.

Document 1 (JP2010-40009A) describes that a light-emitting element (lighting element) irradiates the smoke entering the sensing space (smoke sensing area) with light, and then uses the light-receiving element to receive the scattered light generated by the smoke, thereby sensing the smoke Smoke sensor.

The smoke sensor described in Document 1 is located in a sensing space surrounded by a large number of labyrinth walls, so that smoke can flow into the sensing area through a smoke inflow path formed by the gap of the labyrinth wall. In addition, the labyrinth wall has an external light blocking function that does not make the smoke sensing function unstable due to external light and prevents external light from entering through the smoke inflow path. In Document 1, the smoke sensor housing the light-emitting element and the light-receiving element has a substantially circular shape. In addition, in Document 1, a wide sensing space is formed by protruding the rear portion of the light-emitting element and the light-receiving element (that is, the end on the opposite side to the sensing space).

In the structure described in Document 1, for example, because dirt and foreign matter invade the sensing housing (smoke sensor) surrounding the sensing space, etc., one part of the light output by the light-emitting element is on the inner surface of the sensing housing. Part of it may be reflected to the light-receiving element. As a result, sometimes not only the scattered light generated by the smoke in the sensing space, but also the reflected light on the inner surface of the sensing housing also enters the light-receiving element, so the stray light may increase.

The present disclosure is made in view of the above reasons, and its purpose is to provide a smoke sensor that can suppress the increase of stray light even though the sensing accuracy is improved.

The smoke sensor of one aspect of the present disclosure has a sensing housing, a light-emitting element, a light-receiving element, and a light-shielding structure. The aforementioned sensing housing surrounds the sensing space. The light emitting element outputs light to the sensing space. The light-receiving element is arranged at a position where the direct light from the light-emitting element does not enter and the scattered light generated by the smoke in the sensing space enters. The aforementioned light-shielding structure protrudes into the aforementioned sensing space from the inner surface of the aforementioned sensing housing. The sensing housing includes a wall structure that allows the smoke to pass through and prevents light from passing through. The light-shielding structure is located on the path of light output from the light-emitting element and reflected on the inner surface of the sensing housing for more than one time and then incident on the light-receiving element.

(Embodiment 1) (1) Summary The smoke sensor of this embodiment is a disaster prevention device that reports when it senses smoke generated by a fire or the like. That is, if smoke is generated when a disaster such as a fire occurs, the smoke sensor detects the smoke, and then, for example, the output of an alarm sound or a communication function to communicate with other equipment to report. In this disclosure, the "disaster prevention equipment" refers to equipment installed in facilities for the purpose of preventing disasters such as fires, preventing the expansion of damage due to disasters, or recovering from disasters.

As shown in FIG. 2A and FIG. 2B, the smoke sensor 1 has a housing 2 and various parts are housed in the housing 2. The smoke sensor 1 is installed and used in a facility. In this embodiment, although the smoke sensor 1 is used in non-residential facilities such as hotels, office buildings, schools, welfare facilities, commercial facilities, theme parks, hospitals, and factories, it is not limited to this example. The smoke sensor 1 can also be used in facilities such as collective houses or single-family houses. The smoke sensor 1 is installed in the facility in a state of being installed on the ceiling or wall, for example, in the living room, corridor, or staircase of the facility.

As shown in FIG. 1, the smoke sensor 1 of this embodiment has a sensing case 7, a light-emitting element 4, a light-receiving element 5, and a light-shielding structure 70. The sensing housing 7 surrounds the sensing space Sp1. The light emitting element 4 outputs light to the sensing space Sp1. The light-receiving element 5 is arranged at a position where the direct light from the light-emitting element 4 does not enter and the scattered light generated by the smoke in the sensing space Sp1 enters. Thereby, in the state where the smoke does not exist in the sensing space Sp1, the light receiving element 5 does not receive the light output by the light emitting element 4, and in the state where the smoke exists in the sensing space Sp1, the light receiving element 5 receives the light from the light emitting element 4. The light output and scattered by smoke (scattered light). Therefore, the smoke sensor 1 can sense the smoke in the sensing space Sp1 according to the light receiving state of the light receiving element 5. The sensing housing 7 includes a wall structure 3 that allows smoke to pass through and prevents light from passing through. That is, the wall structure 3 has a function of preventing light from entering the sensing space Sp1 from the outside of the sensing space Sp1 and allowing smoke to enter the sensing space Sp1 from the outside of the sensing space Sp1.

Here, the light shielding structure 70 protrudes from the inner surface 700 of the sensing housing 7 into the sensing space Sp1. The light-shielding structure 70 is located on the light path Op1, Op2, Op3 (please refer to Figure 11A and Figure 11B) for the light output from the light emitting element 4 and reflected on the inner surface 700 of the sensing housing 7 more than once and then enter the light receiving element 5 .

According to this structure, at least a part of the light output from the light-emitting element 4 and reflected on the inner surface 700 of the sensing housing 7 once and then incident on the light-receiving element 5 is shielded by the light-shielding structure 70. Therefore, in the smoke sensor 1 of this embodiment, compared to the structure without the light-shielding structure 70, the light output by the light-emitting element 4 may be reflected by the inner surface 700 of the sensing housing 7 and then enter the light-receiving element 5 Sexual decrease. Therefore, for example, even if dirt and foreign matter intrude into the sensing housing 7 surrounding the sensing space Sp1, a part of the light output by the light emitting element 4 is reflected toward the light receiving element 5 on the inner surface 700 of the sensing housing 7 The possibility is also reduced. As a result, the reflected light on the inner surface 700 of the sensing housing 7 is difficult to enter the light receiving element 5. Therefore, although the sensing accuracy of the smoke sensor 1 is improved, the increase of stray light can be suppressed.

(2) Structure Hereinafter, the structure of the smoke sensor 1 of the present embodiment will be described in detail.

In this embodiment, the smoke sensor 1 is installed on the ceiling of a facility as an example. Hereinafter, in the state where the smoke sensor 1 is installed on the ceiling, the direction perpendicular to the horizontal plane (orthogonal) is the "up and down direction" and the bottom of the up and down direction is "below" for description. The arrow in the "up and down direction" shown in the figure is just for illustration and has nothing to do with the entity. However, these directions do not limit the use direction (installation direction) of the smoke sensor 1. For example, the "below" specified here can be the front (horizontal direction) in the actual smoke sensor 1 setting state.

In addition, in the drawings described below, the structure of the smoke sensor 1 is schematically shown, and the various dimensional relationships in the drawings may be different from the actual product.

(2.1) Overall structure First, the overall structure of the smoke sensor 1 of this embodiment will be described with reference to FIGS. 2A to 5.

The smoke sensor 1 has a frame body 2, a sensing block 10 (please refer to FIG. 3), and a circuit block 20 (please refer to FIG. 3). In addition, in this embodiment, the smoke sensor 1 further includes a sound output unit 61 (please refer to FIG. 3) and a battery 62. The constituent elements of the smoke sensor 1 do not necessarily include the battery 62, and the constituent elements of the smoke sensor 1 may not include the battery 62.

The frame 2 has a circular disc shape in a plan view. The frame 2 is a molded product made of synthetic resin. The frame 2 has a first cover 21 and a second cover 22. The first cover 21 is combined with the second cover 22 in a manner of covering the underside of the second cover 22. The second cover 22 is fixed to the construction surface (the ceiling surface in this embodiment). However, strictly speaking, the second cover 22 is not directly fixed to the construction surface, but is fixed indirectly to the construction surface by being fixed to an installation base fixed to the construction surface.

Here, the first cover 21 and the second cover 22 are both formed in a disc shape and have the same outer peripheral shape in a plan view. Therefore, by combining the first cover 21 and the second cover 22, a disk-shaped frame 2 is formed. The first cover 21 is combined with the second cover 22 by a plurality of (3) screws 63. In a state where the first cover 21 and the second cover 22 are combined with each other, the sensing block 10, the circuit block 20 and the sound output part 61 are accommodated between the first cover 21 and the second cover 22.

The first cover 21 has: a circular first main plate 211; and a first peripheral wall 212 protruding upward from the outer peripheral portion of the upper surface of the first main plate 211. In addition, the first cover 21 further has on the top of the first main board 211: a circuit area 213 for configuring the circuit block 20 (please refer to FIG. 4); and a first audio area 214 (please refer to Figure 4). The first cover 21 further has a button 215 arranged in the circuit area 213. The button 215 is configured to be movable relative to the first main board 211 through a hinge structure, and can be inserted into the inner side of the frame 2, that is, the upper side operation. By pressing the operation button 215, the switches included in the circuit block 20 disposed in the circuit area 213 can be operated.

In addition, a groove 216 extending along the outer periphery is formed under the first main board 211 (please refer to FIG. 2A). The groove 216 is substantially concentric with the outer peripheral edge of the lower surface of the first main plate 211, and is formed over the entire circumference. That is, the groove 216 has an annular shape that is one turn smaller than the outer periphery of the lower surface of the first main plate 211. In addition, a portion of the bottom surface of the groove 216 corresponding to the first sound area 214 is formed with a sound hole 217 that penetrates the first main board 211 in the thickness direction of the first main board 211 (please refer to FIG. 2A).

The second cover 22 has: a circular second main plate 221; and a second peripheral wall 222 protruding upward from the outer peripheral portion of the upper surface of the second main plate 221. In addition, the second cover 22 further has under the second main board 221: a receiving area 223 for disposing the sensing block 10 (please refer to FIG. 3); and a second acoustic area 224 for disposing the sound output part 61. The second cover 22 further has a battery area 225 for accommodating the battery 62 on the upper surface of the second main board 221 (please refer to FIG. 4).

In addition, the second cover 22 further has a plurality of partitions 226 protruding downward from the bottom of the second main board 221. The plurality of partitions 226 can ensure a predetermined gap between the first cover 21 and the second cover 22 by making each front end (lower end) contact the upper surface of the first main board 211. Specifically, in the state where the first cover 21 and the second cover 22 are combined with each other, the upper end surface of the first peripheral wall 212 and the lower surface of the second main plate 221 form a connection between the internal space of the frame 2 and the outside of the frame 2的开部23。 The opening 23. Thereby, the smoke can flow into the internal space of the frame body 2 through the opening 23, that is, the space between the first cover 21 and the second cover 22.

The sensing block 10 has a sensing housing 7, a light-emitting element 4 (please refer to FIG. 6), and a light-receiving element 5 (please refer to FIG. 6). The sensing housing 7 has a circular disc shape in a plan view. The sensing housing 7 is a molded product made of synthetic resin. Here, the sensing housing 7 has at least light-shielding properties. In this embodiment, a part of the sensing housing 7 has a function as a wall structure 3 (please refer to FIG. 5). The wall structure 3 has the function of preventing light from entering the sensing space Sp1 from the outside of the sensing space Sp1 and allowing smoke to enter the sensing space Sp1 from the outside of the sensing space Sp1. In the internal space of the frame 2, the sensing block 10 is arranged above the circuit block 20. The sensing block 10 senses smoke in the sensing space Sp1 (please refer to FIG. 5) in the sensing housing 7.

That is, as shown in FIG. 5, the sensing block 10 and the circuit block 20 are contained in the internal space of the housing 2, that is, in the space between the first cover 21 and the second cover 22. In addition, the internal space of the frame 2 is connected to the outside of the frame 2 through the opening 23 as described above, so smoke can flow into the internal space of the frame 2 through the opening 23. In Fig. 5, a part of the entrance path of smoke is schematically shown with a dashed arrow. In addition, the sensing block 10 has a wall structure 3 that allows smoke to enter the sensing space Sp1 from the outside of the sensing space Sp1, so the smoke flowing into the inner space of the frame 2 can further flow into the sensing space Sp1. In this way, the smoke in the sensing block 10 can be sensed. The sensing block 10 is described in detail in the column of "(2.2) Structure of the sensing block".

The circuit block 20 has: a printed wiring board 201; and a plurality of electronic parts 202 including switches. Many electronic components 202 are mounted on the printed wiring board 201. The light-emitting element 4 and the light-receiving element 5 of the sensing block 10 are electrically connected to the conductor portion of the printed wiring board 201. In addition, the sound output part 61 and the battery 62 are also electrically connected to the conductor part of the printed wiring board 201. In this embodiment, the printed wiring board 201 is arranged below the sensing block 10, that is, between the sensing block 10 and the first main board 211. The sensing block 10 is mounted on one surface (upper surface) of the printed wiring board 201 in the thickness direction.

Here, the circuit block 20 includes a control circuit composed of a plurality of electronic components 202. The control circuit is a circuit that controls the light-emitting element 4, the light-receiving element 5, the sound output unit 61, etc., and drives at least the light-emitting element 4 and performs signal processing on the output signal of the light-receiving element 5. During signal processing, the circuit block 20 determines whether there is smoke in the sensing space Sp1 by comparing the amount of light received by the light receiving element 5 (the size of the output signal) and the critical value. The amount of light received in the light receiving element 5 varies with, for example, the smoke concentration in the sensing space Sp1 and the type of smoke (white smoke, black smoke, etc.). Therefore, the circuit block 20 judges that there is "smoke" when there is a certain concentration of smoke or more in the sensing space Sp1 by comparing with the threshold value. When the circuit block 20 senses the presence of smoke, it outputs an electrical signal for driving the sound output part 61 to the sound output part 61.

The sound output unit 61 receives the electric signal from the circuit block 20 and outputs sound (sound wave). The sound output unit 61 is realized by a speaker or a buzzer that converts electric signals into sound. The sound output unit 61 has a circular disk shape in a plan view.

The battery 62 is housed in the battery area 225 above the second cover 22. The battery 62 may be a primary battery or a secondary battery.

For example, the constituent elements of the automatic fire notification system include the smoke sensor 1 of the present embodiment configured as described above. In addition to the smoke sensor 1, the automatic fire notification system has, for example, a receiver for receiving notification signals (fire signals) from the smoke sensor 1, and a transmitter for operating buttons when a fire is discovered. In the automatic fire notification system, for example, when the smoke sensor 1 detects the occurrence of a fire (the resulting smoke), the smoke sensor 1 sends a notification signal (fire signal) notifying the occurrence of the fire to the receiver.

(2.2) The structure of the sensing block Next, a more detailed structure of the sensing block 10 will be described with reference to FIGS. 6 to 10. However, the drawings described below are schematic diagrams, and the ratio of length or size of each part in the drawings does not necessarily reflect the actual size ratio.

The sensing block 10 has the sensing housing 7, the light emitting element 4 and the light receiving element 5 as described above, and a part of the sensing housing 7 functions as the wall structure 3. The sensing space Sp1 is formed inside the sensing housing 7. In addition, the sensing housing 7 has a light-emitting element holder 8 for holding the light-emitting element 4. In addition, the sensing housing 7 has a light-receiving element holder 9 that holds the light-receiving element 5. That is, the smoke sensor 1 of this embodiment has a light-emitting element holder 8 and a light-receiving element holder 9.

In this embodiment, as shown in FIG. 6, the sensing housing 7 has a first housing 71 and a second housing 72. The second housing 72 is combined with the first housing 71 in a manner of covering the upper surface of the first housing 71. The first housing 71 is fixed to the printed wiring board 201 (please refer to FIG. 3). The first housing 71 has a pair of claws 711 for fixing the first housing 71 on the printed wiring board 201 (please refer to FIG. 7). A pair of claws 711 protrude downward from the outer periphery of the lower surface of the first housing 71, and by hooking the periphery of the hole of the printed wiring board 201, the first housing 71 is fixed on the printed wiring board 201. In other words, the first housing 71 and the printed wiring board 201 are mechanically combined by a snap fit.

Here, the first housing 71 and the second housing 72 are both circular in plan view, and the outer peripheral shape in plan view is substantially the same. Therefore, by combining the first housing 71 and the second housing 72, a disc-shaped sensing housing 7 is formed. The first housing 71 has a pair of claws 712 for connecting the first housing 71 and the second housing 72 (please refer to FIG. 7). A pair of claws 712 protrude upward from the outer peripheral part of the upper surface of the first housing 71, and by hooking the outer peripheral surface of the second housing 72, the first housing 71 and the second housing 72 are combined. In other words, the first housing 71 and the second housing 72 are mechanically combined by a snap fit. In a state where the first housing 71 and the second housing 72 are combined with each other, a sensing space Sp1 is formed between the first housing 71 and the second housing 72.

The first housing 71 has a bottom plate 73 and a wall structure 3 that protrudes upward from the outer peripheral portion of the (first) inner bottom surface 731 on the upper surface of the bottom plate 73. The inner bottom surface 731 of the bottom plate 73 constitutes the bottom surface of the sensing space Sp1. In addition, the first housing 71 further has: a first support 81 constituting a part of the light-emitting element support 8; and a light-receiving element support 9. In addition, the first housing 71 further has: a light-shielding wall 74 (please refer to FIG. 7), a light-shielding rib 75 (please refer to FIG. 7), and an auxiliary light-shielding wall 76 (please refer to FIG. 7) described later. The first bracket 81, the light-receiving element bracket 9, the light-shielding wall 74, the light-shielding rib 75, and the auxiliary light-shielding wall 76 respectively protrude upward from the inner bottom surface 731 of the bottom plate 73. Here, the protrusion amount of the light emitting element holder 8, the light receiving element holder 9, the light shielding wall 74 and the auxiliary light shielding wall 76 from the inner bottom surface 731 of the bottom plate 73 is substantially the same as the protrusion amount of the wall structure 3 from the inner bottom surface 731 of the bottom plate 73.

The second housing 72 has: a circular upper plate 721; and a peripheral wall 722, which protrudes downward from the outer peripheral portion of the (second) inner bottom surface 725 below the plate 721. The inner diameter of the peripheral wall 722 is larger than the outer diameter of the wall structure 3. In addition, the amount of protrusion of the peripheral wall 722 from the inner bottom surface 725 of the upper plate 721 is substantially the same as the amount of protrusion of the wall structure 3 from the inner bottom surface 731 of the bottom plate 73. Therefore, in the state where the first housing 71 and the second housing 72 are coupled to each other, the front end surface (lower end surface) of the peripheral wall 722 contacts the inner bottom surface 731 of the bottom plate 73, and the front end surface (upper end surface) of the wall structure 3 contacts the upper plate 721之内底面725。 The inner bottom surface 725. In this state, the wall structure 3 is housed in the space surrounded by the peripheral wall 722.

A plurality of window holes 723 penetrating the peripheral wall 722 in the thickness direction of the peripheral wall 722 are formed in the peripheral wall 722. The plurality of window holes 723 are arranged along the circumferential direction of the inner bottom surface 725 of the upper plate 721. Thereby, in the state where the first housing 71 and the second housing 72 are combined with each other, the wall structure 3 exposes the outside of the sensing housing 7 through the plurality of window holes 723. Here, the anti-insect net can be installed on the peripheral wall 722 in a manner that covers most of the window holes 723. The anti-insect net reduces foreign matter such as insects from entering the sensing space Sp1 in the sensing housing 7 through a plurality of windows 723.

In addition, the second housing 72 further has a second bracket 82 that forms a part of the light-emitting element bracket 8 (please refer to FIG. 9). The second holder 82 and the first holder 81 constitute the light emitting element holder 8. In other words, the light-emitting element holder 8 is divided into two components: the first holder 81 provided in the first housing 71 and the second holder 82 provided in the second housing 72. In addition, the second housing 72 has a light-shielding rib 724 as a "second light-shielding rib" at a position opposite to the light-shielding rib 75 as a "first light-shielding rib" in the inner bottom surface 725 of the upper plate 721 (please refer to FIG. 9). ).

The light shielding structure 70 protruding into the sensing space Sp1 from the inner surface 700 of the sensing housing 7 (please refer to FIG. 1) includes a (first) light shielding rib 75 and a (second) light shielding rib 724. That is, the light-shielding rib 75 and the light-shielding rib 724 constitute at least a part of the light-shielding structure 70. The light-shielding structure 70 is described in detail in the column of "(2.3) Structure of the light-shielding structure".

As shown in FIG. 8A, when viewed from a direction (upward) perpendicular to the inner bottom surface 731 (a plane) of the bottom plate 73, the wall structure 3 surrounds the sensing space Sp1. FIG. 8A is a plan view of the state where the second housing 72 is removed, that is, the sensing block 10 of the second housing 72 is omitted. In this embodiment, a circular sensing space Sp1 in plan view is formed on the inner bottom surface 731 of the bottom plate 73. The wall structure 3 is formed in a circular ring shape so as to surround the sensing space Sp1 on the entire circumference in a plan view. In other words, the annular wall structure 3 is formed on the outer periphery of the inner bottom surface 731 of the bottom plate 73 along the outer periphery of the inner bottom surface 731. In a state where the first housing 71 and the second housing 72 are coupled to each other, the space between the bottom plate 73 and the upper plate 721 and surrounded by the wall structure 3 becomes the sensing space Sp1. That is, the sensing space Sp1 and the space around the sensing space Sp1 are separated by the wall structure 3.

At this time, the wall structure 3 has, on both sides of the thickness direction of the wall structure 3, an inner surface 31 facing the sensing space Sp1 side, and an outer surface 32 facing the opposite side of the sensing space Sp1. The wall structure 3 allows smoke to pass through in the thickness direction and suppresses light transmission. That is, the wall structure 3 is a structure having a predetermined thickness in a plan view and has an inner surface 31 and an outer surface 32 on both sides in the thickness direction. In this embodiment, the wall structure 3 sets the radial direction of the inner bottom surface 731 of the bottom plate 73, that is, along the direction of the inner bottom surface 731 (a flat surface) of the bottom plate 73, that is, from the periphery of the sensing space Sp1 to the sensing space Sp1 The direction of the center is the thickness direction of the wall structure 3. In addition, the wall structure 3 has a function of allowing smoke to pass between the inner surface 31 and the outer surface 32 and suppressing the transmission of light. Thereby, the wall structure 3 can prevent light from entering the sensing space Sp1 from the outside of the sensing space Sp1 and make smoke enter the sensing space Sp1 from the outside of the sensing space Sp1. In this embodiment, the thickness of the wall structure 3 is substantially uniform over the entire circumference, and in plan view, the outer periphery of the inner bottom surface 731, the inner surface 31, and the outer surface 32 are substantially concentric.

In order to achieve the above function, such a wall structure 3 has a wall structure 3 penetrating in the thickness direction, that is, a plurality of smoke passing holes 33 between the inner surface 31 and the outer surface 32. Most of the smoke passing holes 33 are arranged along the circumferential direction of the wall structure 3. Thereby, the wall structure 3 can allow smoke to pass through the smoke passage holes 33, and the smoke can enter the sensing space Sp1 from the outside of the sensing space Sp1. Here, each smoke passage hole 33 is not a shape that straightly penetrates between the inner side surface 31 and the outer side surface 32 in plan view, but a shape in which at least a part of the inner side surface 31 and the outer side surface 32 is curved. That is, at least a part of each smoke passage hole 33 has a curved or buckled shape, so even if the smoke passage hole 33 passes through the outer side surface 32 of the wall structure 3, it is impossible to see through the sensing space Sp1 surrounded by the wall structure 3 . Thereby, light can be prevented from passing through each smoke passage hole 33 to pass through the wall structure 3, and light can be prevented from entering the sensing space Sp1 from the outside of the sensing space Sp1. However, the smoke passage hole 33 does not need to be surrounded by the wall structure 3 all around. For example, the wall structure 3 may not have the smoke passage hole 33 on both sides in the upper and lower directions. In addition, the openings on the inner surface 31 and the outer surface 32 of each smoke passage hole 33 may not be arranged on the radius of the sensing space Sp1 in plan view, that is, radially from the center point P1 of the sensing space Sp1 Extending on a straight line.

Specifically, the wall structure 3 is an assembly of a large number of small pieces 30 arranged along the inner surface 31. Smoke can pass through the wall structure 3 between the plurality of small pieces 30. In other words, the small pieces 30 are arranged on the outer periphery of the inner bottom surface 731 of the bottom plate 73 at intervals along the outer periphery of the inner bottom surface 731. Many small pieces 30 protrude from the inner bottom surface 731 of the bottom plate 73 and constitute a wall structure 3. The amount of protrusion from the inner bottom surface 731 of the bottom plate 73 is approximately uniform. The wall structure 3 respectively has smoke passage holes 33 between a pair of adjacent small pieces 30 among the plurality of small pieces 30. Therefore, the small pieces 30 constituting the wall structure 3 do not have the upper and lower sides of each smoke passage hole 33.

The inner surface 31 is a surface passing through the edge 301 on the sensing space Sp1 side of the plurality of small pieces 30. The outer surface 32 is a surface passing through the end edge 302 on the opposite side of the sensing space Sp1 of the plurality of small pieces 30. In short, the smooth curved surface, the flat surface or the combination of the flat surface and the curved surface connecting the end edge 301 on the sensing space Sp1 side of the plurality of small pieces 30 corresponds to the inner surface 31. Similarly, a smooth curved surface, a flat surface, or a combination of a flat surface and a curved surface connecting the edge 302 on the opposite side of the sensing space Sp1 of the plurality of small pieces 30 corresponds to the outer surface 32.

In other words, the end edge 301 on the side of the sensing space Sp1 of the plurality of small pieces 30 is located on the inner side surface 31, and the end edge 302 on the opposite side of the sensing space Sp1 of the majority of small pieces 30 is located on the outer side surface 32. In the small pieces 30 that are connected to the auxiliary light-shielding wall 76 described later among the many small pieces 30, the end edge 301 on the side of the sensing space Sp1 is located on the inner surface 31 and opposite to the sensing space Sp1 of the many small pieces 30, similarly to the other small pieces 30. The side edge 302 is located on the outer side surface 32. In this way, each side surface of the inner surface 31 and the outer surface 32 does not have a physical surface in this embodiment, but a virtual surface whose shape is defined by a plurality of small pieces 30. Therefore, in FIGS. 8A and 8B, the inner surface 31 and the outer surface 32 are represented by imaginary lines (two-dot dashed line). In addition, halftone dots (dot shading) are added to the area corresponding to the wall structure 3 in FIG. 8A.

However, the positions of all the end edges 301 of most small pieces 30 do not have to be exactly the same as the inner side surface 31, and the positions of the end edges 301 of most small pieces 30 may be roughly the same as the inner side surface 31. In the example of FIG. 8A, the position of the edge 301 on the sensing space Sp1 side of the majority of the small pieces 30 is exactly the same as that of the inner surface 31, while the position of the edge 301 of the remaining small pieces 30 is on the inner surface 31. Nearby, but not completely consistent with the inner surface 31. In this way, the inner surface 31 is defined by the position of the edge 301 of more than half of the small pieces 30 in the plurality of small pieces 30, and the end edge 301 of the remaining small pieces 30 can be near the inner surface 31. The same is true for the outer side 32, that is, the positions of the end edges 302 of the majority of the small pieces 30 do not need to be completely consistent with the outer side 32, and the positions of the end 302 of the majority of the small pieces 30 are roughly the same as the outer side 32. That is, the outer surface 32 is defined by the position of the edge 302 of more than half of the small pieces 30, and the edge 302 of the remaining small pieces 30 may be near the outer surface 32. The so-called "nearby" here is viewed from the inner surface 31 or the outer surface 32, which is about 20% of the thickness of the wall structure 3.

In this embodiment, in a plan view, the outer surface 32 is substantially parallel to the outer periphery of the inner bottom surface 731 of the bottom plate 73, that is, the distance from the outer periphery of the inner bottom surface 731 to the outer surface 32 is uniform over the entire circumference. In addition, as shown in FIG. 8A, the inner side surface 31 is formed between the center point P1 and the outer side surface 32 of the sensing space Sp1 and is closer to the outer side surface 32 than the center point P1. In other words, in a plan view, when a substantially concentric circle with the outer side surface 32 is drawn, that is, an imaginary circle whose radius is half (1/2) of the outer side surface 32, the inner side surface 31 is located between the imaginary circle and the outer side surface 32. However, the shape and arrangement of each side surface of the inner surface 31 and the outer surface 32 are just an example, and the respective side surfaces of the inner surface 31 and the outer surface 32 may adopt other shapes and arrangements.

Here, in plan view, each of the small pieces of the plurality of small pieces 30 has a curved portion between the end edge 301 on the side of the sensing space Sp1 and the end edge 302 on the side opposite to the sensing space Sp1. In this embodiment, each small piece of the plurality of small pieces 30 forms a substantially L-shape, a substantially V-shape, or a substantially Y-shape in plan view. With such a shape, each smoke passage hole 33 formed by the gap between a pair of adjacent small pieces 30 is formed in a curved shape in at least a part between the inner surface 31 and the outer surface 32 in a plan view as described above. . Thereby, the wall structure 3 can realize the function of passing smoke in the thickness direction and suppressing light transmission.

The light emitting element 4 has a light emitting surface 41 (please refer to FIG. 7), and when energized, the light emitting surface 41 outputs light. In this embodiment, for example, the light emitting element 4 is a light emitting diode (LED: Light Emitting Diode). As shown in FIG. 6, the light-emitting element 4 has a main body 401. A pair of lead terminals 402 protrude from the surface of the main body 401. Here, the pair of lead terminals 402 are electrically connected to the main body 401 of the light-emitting element 4. With a pair of lead terminals 402 electrically connected to the printed wiring board 201, the light-emitting element 4 receives power from the circuit block 20 and emits light. In this embodiment, although it is described that the component of the light emitting element 4 does not include a pair of lead terminals 402, the component of the light emitting element 4 may also include a pair of lead terminals 402.

Here, as shown in FIG. 8A, the light emitting element 4 is arranged between the inner surface 31 and the outer surface 32 of the wall structure 3. In other words, the main body portion 401 of the light-emitting element 4 is arranged to be housed between the inner surface 31 and the outer surface 32 that form both end surfaces in the thickness direction of the wall structure 3. In addition, the light emitting element 4 has a light emitting surface 41 facing the inner surface 31 side, that is, the sensing space Sp1 side. Therefore, the light emitting element 4 can output light from the light emitting surface 41 to the sensing space Sp1 without using optical elements such as mirrors.

In this embodiment, as shown in FIG. 9, the light-emitting element 4 further has: a back surface 42 facing the outer surface 32 side; and a bottom surface 43 connecting the light exit surface 41 and the back surface 42. Fig. 9 is an enlarged cross-sectional view of area Z1 in Fig. 5. A pair of leads electrically connected to the light-emitting element 4 protrudes from the bottom surface 43. In this embodiment, the lead wire terminal 402 protrudes from the bottom surface 43. In other words, the light emitting element 4 has a light emitting surface 41 and a back surface 42 on both sides of the thickness direction of the wall structure 3 of the main body 401. In addition, the lead terminal 402 does not protrude from the light exit surface 41 and the back surface 42, but protrudes from the bottom surface 43 adjacent to both the light exit surface 41 and the back surface 42. That is, the light-emitting element 4 is a so-called side-view type light-emitting diode that outputs light to the side when the surface on which the lead terminal 402 protrudes (the bottom surface 43) faces downward.

In addition, in the present embodiment, the lead (lead terminal 402) protrudes from the light-emitting element 4 in a direction (here, below) perpendicular to the optical axis Ax1 of the light-emitting element 4 (refer to FIG. 10). That is, the lead terminal 402 protrudes downward from the bottom surface 43 as described above, and a part of the lead terminal 402 does not have a bent structure, and the lead terminal 402 can be extended downward from the light emitting element 4.

Compared with the light-emitting element in which the lead terminal protrudes from the side opposite to the light-emitting surface, the light-emitting element 4 constructed in this way can be reduced in the thickness direction of the wall structure 3 as a so-called cannonball type light-emitting diode. Occupies space. That is, in a side-view light-emitting diode, the lead terminal 402 protruding from the bottom surface 43 can extend from the light-emitting element 4 with the light-emitting surface 41 facing the inner surface 31 side in a direction perpendicular to the thickness direction of the wall structure 3 . Thereby, the thickness direction dimension of the wall structure 3 can be suppressed to be relatively small, and as described above, between the inner surface 31 and the outer surface 32 of the wall structure 3, the light exit surface 41 can be arranged toward the inner surface 31 side. Luminescent element 4.

Here, the bottom surface 43 extends along the inner bottom surface 731 (a flat surface) of the bottom plate 73. In this embodiment, the bottom surface 43 is not parallel to the inner bottom surface 731 of the bottom plate 73 but is inclined to the inner bottom surface 731. However, the bottom surface 43 may extend along the inner bottom surface 731 of the bottom plate 73 and may be substantially parallel to the inner bottom surface 731.

In more detail, the light exit surface 41 includes a flat portion 411 and a convex portion 412. The flat portion 411 is a plane substantially parallel to the back surface 42. The convex part 412 protrudes from the flat part 411 into a dome shape, and has the function of a convex lens. As shown in FIG. 9, the main body part 401 has a light emitting part 403 and a lead part 404. The light emitting part 403 is mounted on the surface of the lead part 404 facing the outer side surface 32 side, and emits light when power is supplied. The lead portion 404 and the lead terminal 402 are formed integrally.

The light receiving element 5 is an element that performs photoelectric conversion that converts light into electrical signals. In this embodiment, for example, the light receiving element 5 is a photodiode (PD: Photodiode). As shown in FIG. 6, the light receiving element 5 has a main body 501, a pair of lead terminals 502 and a metal cover 503. The main body 501 is housed in the metal cover 503 in such a way that at least the light-receiving surface of the main body 501 is exposed through the holes of the metal cover 503. A pair of lead terminals 502 protrude from the bottom of the main body 501. Here, a pair of lead terminals 502 are electrically connected to the main body 501 of the light receiving element 5. With a pair of lead terminals 502 electrically connected to the printed wiring board 201, the light receiving element 5 is electrically connected to the circuit block 20.

Here, the light receiving element 5 is arranged at a position where the direct light from the light emitting element 4 does not enter and the scattered light generated by the smoke in the sensing space Sp1 enters. Specifically, the light receiving element 5 is configured with the light receiving surface of the main body 501 facing the sensing space Sp1 side. That is, both the light-emitting element 4 and the light-receiving element 5 are arranged toward the sensing space Sp1 side. However, as shown in FIG. 7, in a plan view, the light-shielding wall 74 is arranged on a straight line connecting the light-emitting element 4 and the light-receiving element 5. The light shielding wall 74 has a function of shielding direct light from the light emitting element 4 to the light receiving element 5. In this embodiment, the light-shielding wall 74 is formed in a shape that continues one of the small pieces 30 constituting the wall structure 3. FIG. 7 is a plan view of the state where the second housing 72 is removed, that is, the sensing block 10 of the second housing 72 is omitted.

Next, as shown in FIG. 8A, in a plan view, the light-emitting element 4 and the light-receiving element 5 are arranged in a positional relationship where the optical axis Ax1 of the light-emitting element 4 and the optical axis Ax2 of the light-receiving element 5 cross each other. In the example of FIG. 8A, the optical axis Ax1 of the light-emitting element 4 and the optical axis Ax2 of the light-receiving element 5 intersect at the center point P1 of the circular sensing space Sp1 in the plan view. If the light-emitting element 4 and the light-receiving element 5 have the positional relationship as described above, the direct light from the light-emitting element 4 does not enter the light-receiving element 5. On the other hand, when smoke flows into the sensing space Sp1, the light from the light emitting element 4 is scattered by the smoke at the center point P1 of the sensing space Sp1, and at least a part of the scattered light is received by the light receiving element 5.

In this way, in the state where the smoke does not exist in the sensing space Sp1, the light receiving element 5 does not receive the light output by the light emitting element 4, and in the state where the smoke exists in the sensing space Sp1, the light receiving element 5 receives the light output from the light emitting element 4 and because Light scattered by smoke (scattered light). Therefore, the smoke sensor 1 can sense the smoke in the sensing space Sp1 according to the light receiving state of the light receiving element 5.

At this time, in this embodiment, the light-emitting element 4 is housed within the thickness of the wall structure 3 as described above. Therefore, compared with the structure where the light-emitting element 4 protrudes from the inner surface 31 of the wall structure 3, a wide sensing range can be ensured. Space Sp1. If the sensing space Sp1 is wide, the configuration of the light shielding wall 74 in the sensing space Sp1 has a high degree of freedom. In addition, if the sensing space Sp1 is wide, the light shielding wall 74 can be arranged at a position relatively far from the center point P1 of the sensing space Sp1.

In addition, in this embodiment, as shown in FIG. 10, the optical axis Ax1 of the light-emitting element 4 and the optical axis Ax2 of the light-receiving element 5 extend along the inner bottom surface 731 (a flat surface) of the bottom plate 73. Fig. 10 is an end view of the line A1-A1 in Fig. 7; In the example of FIG. 10, the optical axis Ax1 of the light-emitting element 4 and the optical axis Ax2 of the light-receiving element 5 are both substantially parallel to the inner bottom surface 731 of the bottom plate 73. In addition, the optical axis Ax1 of the light-emitting element 4 and the optical axis Ax2 of the light-receiving element 5 are located in the same plane. In other words, the optical axis Ax1 of the light-emitting element 4 and the optical axis Ax2 of the light-receiving element 5 are at substantially the same height relative to the inner bottom surface 731 of the bottom plate 73.

In addition, the light-shielding rib 75 is arranged on the front surface of the light-emitting element 4 in plan view, that is, at a position opposite to the light-emitting surface 41 of the light-emitting element 4. As shown in FIG. 9, a certain gap is formed between the light shielding rib 75 and the light shielding rib 724 provided in the second housing 72. The optical axis Ax1 of the light emitting element 4 passes through the gap between the light shielding rib 75 and the light shielding rib 724. Therefore, the light-shielding rib 75 and the light-shielding rib 724 can suppress the light output from the light emitting element 4 from spreading in the vertical direction. As a result, the light output from the light emitting element 4 can be suppressed from being reflected on the upper surface of the bottom plate 73 (inner bottom surface 731) or the lower surface of the upper plate 721 (inner bottom surface 725).

In addition, the auxiliary light-shielding wall 76 is formed in the shape of one piece located between the light-shielding wall 74 and the light-receiving element holder 9 among the plurality of small pieces 30 constituting the wall structure 3. The auxiliary light shielding wall 76 protrudes from the inner side surface 31 of the wall structure 3 into the sensing space Sp1. The auxiliary light-shielding wall 76 suppresses the generation of stray light in the sensing space Sp1 due to the reflection of light on the inner bottom surface 731 of the bottom plate 73 or the inner bottom surface 725 of the upper plate 721, and makes the smoke flow into the sensing space Sp1. Improved performance. That is, the auxiliary light-shielding wall 76 is a structure other than the small piece 30 which is used to prevent light from entering from the outside of the sensing space Sp1 into a part of the wall structure 3 of the sensing space Sp1. In FIG. 7, the boundary line between the auxiliary light-shielding wall 76 and the small piece 30 is indicated by a virtual line (two-dot dashed line).

The light-emitting element holder 8 is divided into two components: the first holder 81 provided in the first housing 71 and the second holder 82 provided in the second housing 72 as described above, and holds the light-emitting element 4. Here, as shown in FIG. 8A, at least a part of the light-emitting element holder 8 is arranged between the inner surface 31 and the outer surface 32. Specifically, the first bracket 81 is arranged between the plurality of small pieces 30 constituting the wall structure 3 such that most of the first bracket 81 is accommodated between the inner surface 31 and the outer surface 32. The first bracket 81 has a recess into which the light-emitting element 4 is embedded.

In addition, in this embodiment, the light-emitting element holder 8 is arranged so as to be housed in the area surrounded by the outer surface 32. That is, the light-emitting element holder 8 (including the first holder 81) is not exposed from the outer surface 32, and has a shape that is housed in a region surrounded by the outer surface 32.

In addition, the light-emitting element holder 8 has a wire hole 801 for electrically connecting to the lead wire of the light-emitting element 4. In this embodiment, the lead wire passing through the via 801 is the lead terminal 402. The via hole 801 is formed in the first bracket 81. At this time, as shown in FIG. 8B, the via hole 801 is formed between the inner surface 31 and the outer surface 32 and is closer to the outer surface 32 than the inner surface 31. In other words, as shown in FIG. 8A, when the center line C1 that divides the wall structure 3 into two in the thickness direction is drawn in a plan view, the via 801 is located between the center line C1 and the outer side surface 32.

In addition, as shown in FIG. 7, the light-emitting element holder 8 further has a light-shielding sheet 802. The light shielding sheet 802 protrudes into the sensing space Sp1 from the surface of the first bracket 81 facing the sensing space Sp1 side. Here, the light-shielding sheet 802 protrudes from the end portion of the first holder 81 on the side away from the light-shielding wall 74 in the circumferential direction of the wall structure 3. The light-shielding sheet 802 has a function of shielding the light output from the light-emitting element 4 and reflected on the surface of the light-emitting element holder 8.

The light shielding structure 70 protruding from the inner surface 700 of the sensing housing 7 (please refer to FIG. 1) into the sensing space Sp1 includes a light shielding sheet 802. That is, in this embodiment, the light-shielding sheet 802, the light-shielding rib 75 and the light-shielding rib 724 constitute at least a part of the light-shielding structure 70. The light-shielding structure 70 is described in detail in the column of "(2.3) Structure of the light-shielding structure".

In addition, as shown in FIG. 9, the light-emitting element holder 8 further has a positioning surface 803. The positioning surface 803 is a surface intersecting the optical axis Ax1 of the light-emitting element 4, and the light-emitting element 4 is positioned by contacting the light-emitting element 4 from the outer surface 32 side. That is, the positioning surface 803 contacts the back surface 42 of the light-emitting element 4, and the light-emitting element 4 is positioned in the thickness direction of the wall structure 3. In this embodiment, the light-emitting element holder 8 is divided into two members of the first holder 81 and the second holder 82 as described above, so the positioning surface 803 is also formed by the two members of the first holder 81 and the second holder 82 .

In addition, in this embodiment, the positioning surface 803 has elasticity, that is, springiness. The positioning surface 803 makes the elastic force pressed against the light-emitting element 4 from the outer side surface 32 act on the light-emitting element 4. In this embodiment, since the light-emitting element holder 8 is made of synthetic resin, since at least the second holder 82 has a function as a resin spring, the above-mentioned elasticity can be imparted to the positioning surface 803.

The light-receiving element holder 9 holds the light-receiving element 5. Here, as shown in FIG. 8A, at least a part of the light receiving element holder 9 is arranged between the inner surface 31 and the outer surface 32. Specifically, the light-receiving element holder 9 is arranged between the plurality of small pieces 30 constituting the wall structure 3 such that most of the light-receiving element holder 9 is accommodated between the inner surface 31 and the outer surface 32. The light-receiving element holder 9 has a recess in which the light-receiving element 5 is inserted.

(2.3) Structure of shading structure Next, a more detailed structure of the light-shielding structure 70 will be described with reference to FIGS. 1, 11A, and 11B. In FIGS. 11A and 11B, a part of the path (light path) of the light output by the light-emitting element 4 is schematically shown with a dotted arrow. However, the drawings described below are schematic diagrams, and the ratio of length or size of each part in the drawings does not necessarily reflect the actual size ratio.

The smoke sensor 1 of the present embodiment has the light shielding structure 70 projecting from the inner surface 700 of the sensor housing 7 into the sensing space Sp1 as described above. In the present disclosure, the “inner surface 700 of the sensing housing 7 ”is a surface on the inner side of the sensing housing 7 and is a surface facing the sensing space Sp1 side as the internal space of the sensing housing 7. In this embodiment, the inner surface 700 of the sensing housing 7 includes: the inner surface 31 of the wall structure 3, the inner bottom surface 731 of the first housing 71 (above the bottom plate 73), and the inner bottom surface 725 of the second housing 72 (Below the upper plate 721). In addition, the inner surface 700 of the sensing housing 7 also includes the surface of the light-emitting element holder 8 and the light-receiving element holder 9 facing the sensing space Sp1.

The smoke sensor 1 of this embodiment includes the light-shielding sheet 802, the light-shielding rib 75, and the light-shielding rib 724 as the light-shielding structure 70 as described above. That is, the light-shielding sheets 802, the light-shielding ribs 75, and the light-shielding ribs 724 all protrude from the inner surface 700 of the sensing housing 7 into the sensing space Sp1. In addition, the light-shielding sheet 802, the light-shielding ribs 75, and the light-shielding ribs 724 are located in the paths Op1, Op2, Op3 of the light output by the light-emitting element 4 and reflected on the inner surface 700 of the sensing housing 7 more than once and then incident on the light-receiving element 5. (Please refer to Figure 11A and Figure 11B).

The smoke sensor 1 is provided with such a light-shielding structure 70, and the light-shielding structure 70 can be used to shield at least one of the light output by the light-emitting element 4 and reflected on the inner surface 700 of the sensing housing 7 more than once and then incident on the light-receiving element 5 Part. That is, it is difficult to control the reflection direction of the light reflected on the inner surface 700 of the sensing housing 7 to be the same, and it changes greatly due to the intrusion of dirt and foreign matter into the sensing housing 7 surrounding the sensing space Sp1 and so on. Therefore, when the reflected light from the inner surface 700 of the sensing housing 7 enters the light receiving element 5, it affects the amount of light received by the light receiving element 5 (the size of the output signal), and further affects the sensing of the smoke sensor 1. The results have an impact. In short, the light output from the light-emitting element 4 and reflected on the inner surface 700 of the sensing housing 7 more than once becomes the so-called “stray light” and becomes a factor that degrades the sensing accuracy of the smoke sensor 1. The smoke sensor 1 of this embodiment shields at least a part of the stray light as described above with the light-shielding structure 70, which can suppress the increase of stray light even though the sensing accuracy is improved.

In more detail, in this embodiment, as shown in FIG. 1, the sensing housing 7 has a light-emitting element holder 8 that holds the light-emitting element 4. In addition, the light-shielding structure 70 includes a light-shielding sheet 802 protruding from the light-emitting element holder 8. The light-shielding sheet 802 protrudes into the sensing space Sp1 from the surface of the light-emitting element holder 8 facing the sensing space Sp1. Here, the emission port 804 of the light-emitting element holder 8 that emits light from the light-emitting element 4 is formed in the surface of the light-emitting element holder 8 facing the sensing space Sp1 side. In addition, the light-shielding sheet 802 is located around the emission port 804 of the light-emitting element holder 8. Here, the light-shielding sheet 802 is not provided on the entire circumference of the ejection outlet 804, but is provided only on one side of the ejection outlet 804 in plan view. Specifically, as viewed from the emission port 804, the light-shielding sheet 802 is arranged at a position on the opposite side of the light-shielding wall 74 in the circumferential direction of the wall structure 3. In short, in a plan view, the light-shielding sheet 802 is formed asymmetrically with respect to the optical axis Ax1 of the light-emitting element 4 (please refer to FIG. 11A). Since the light shielding sheet 802 is asymmetric, the light that can become stray light components is easily shielded by the light shielding sheet 802, and the light that reaches the light receiving element 5 after being scattered by the smoke in the sensing space Sp1 is difficult to be shielded by the light shielding sheet 802. Therefore, according to the light-shielding sheet 802 with such a structure, the increase of stray light can be suppressed even though the improvement of the sensing accuracy is achieved.

In addition, the light-shielding sheet 802 is formed integrally with the first bracket 81 provided in the first housing 71, and in a plan view, forms a triangle with a tapered front end. In addition, the light-shielding sheet 802 is formed by substantially the full width in the upper and lower direction of the sensing space Sp1. That is, in the sensing space Sp1, the light-shielding sheet 802 is formed between a pair of inner bottom surfaces 731 and 725 located on the upper and lower sides of the sensing space Sp1.

As shown in FIG. 11A, the light-shielding sheet 802 of the above-described structure is located on the light-emitting element 4 and reflected on the surface of the light-emitting element holder 8 and reflected on the inner surface 700 of the sensing housing 7 for more than one time and then enters the light-receiving element. 5 on Op1, the path of light. That is, at least a part of the light output from the light-emitting element 4 and reflected on the inner surface 700 of the sensing housing 7 after being incident on the light-receiving element 5 is shielded by the light-shielding sheet 802 of the light-shielding structure 70.

Without the light-shielding sheet 802, the light passing through the passage Op1 is reflected on the inner surface 31 of the wall structure 3 included in the inner surface 700 of the sensing housing 7, and sometimes enters the light receiving element 5. In the smoke sensor 1 of the present embodiment, since the light shielding sheet 802 is located on such a passage Op1, the light passing through the passage Op1 can be shielded by the light shielding sheet 802, so that the generation of "stray light" can be suppressed. However, because the inner surface 31 of the wall structure 3 included in the inner surface 700 of the sensing housing 7 is not a solid surface, but an imaginary surface whose shape is defined by a plurality of small pieces 30, strictly speaking, the light of the inner surface 31 The reflection is generated on the surface of most small pieces 30.

Here, in this embodiment, the half-value angle q1 of the light-emitting element 4 is 25 degrees or more. The so-called "half value angle" in the present disclosure is to make the brightness on the optical axis Ax1 100%. Pay attention to the brightness reduction rate when the optical axis Ax1 is slowly moved away, and the angle (q1) when the brightness becomes 50%. In this way, when a relatively wide-angle element with a half-value angle q1 of 25 degrees or more is used as the light-emitting element 4, reflection on the surface of the light-emitting element holder 8 is likely to occur, and the light beam passing through the passage Op1 is large. Therefore, it is particularly useful to provide the light-shielding sheet 802 as the light-shielding structure 70 as in this embodiment.

In addition, in a plan view, a path of light is also generated at a position symmetrical to the optical axis Ax1 of the light-emitting element 4 and the path Op1 described above. However, because the light in such a passage is output from the exit 804 to the light shielding wall 74 (please refer to FIG. 7), it is shielded by the light shielding wall 74, and it is difficult to form stray light. Therefore, in a plan view, even if the light-shielding sheet 802 is provided only on one side of the emission port 804, the light-shielding sheet 802 can sufficiently suppress the generation of "stray light".

In addition, as shown in FIG. 1, the sensing housing 7 has a pair of inner bottom surfaces 731 and 725 facing each other in the up-down direction (one direction) as a part of the light-shielding structure inner surface 700. The light-shielding structure 70 includes light-shielding ribs 75 and 724 protruding from at least one of the pair of inner bottom surfaces 731 and 725. In this embodiment, the light-shielding ribs 75 and 724 protrude from a pair of inner bottom surfaces 731 and 725, respectively. That is, the light shielding structure 70 includes: a (first) light shielding rib 75 protruding upward from the inner bottom surface 731 of the first housing 71; and a (second) light shielding rib protruding downward from the inner bottom surface 725 of the second housing 72 724.

Here, the light-shielding rib 75 and the light-shielding rib 724 are formed so that their front end faces face each other. In addition, a certain gap is ensured between the two light-shielding ribs 75 and 274. As shown in FIG. 11B, the optical axis Ax1 of the light-emitting element 4 passes through the gap between the light-shielding rib 75 and the light-shielding rib 724. Therefore, the light-shielding rib 75 and the light-shielding rib 724 can suppress the light output from the light emitting element 4 from spreading in the vertical direction.

In other words, the light-shielding ribs 75 and 724 are located on the passages Op2 and Op3 of light output from the light-emitting element 4 and incident on at least one of the pair of inner bottom surfaces 731 and 725. In this embodiment, the light-shielding rib 75 arranged below the optical axis Ax1 of the light-emitting element 4 is located on the passage Op2 of the light output from the light-emitting element 4 and incident on the inner bottom surface 731. The light-shielding rib 724 arranged above the optical axis Ax1 of the light-emitting element 4 is located on the passage Op3 of the light output from the light-emitting element 4 and incident on the inner bottom surface 725.

In addition, the light-shielding ribs 75 and 724 are arranged at positions overlapping the optical axis Ax1 of the light-emitting element 4 in a plan view (please refer to FIG. 11A). Specifically, the light-shielding rib 75 and the light-shielding rib 724 are both arranged on the front surface of the light-emitting element 4 in plan view. In FIG. 11A, although only the light-shielding rib 75 is shown, the position and shape of the light-shielding rib 724 in a plan view are also the same as the light-shielding rib 75.

In addition, the light-shielding ribs 75 and 724 have a shape extending in a direction crossing the optical axis Ax1 of the light-emitting element 4. Specifically, the light-shielding rib 75 and the light-shielding rib 724 are formed in a flat plate shape orthogonal to the optical axis Ax1 of the light-emitting element 4. Therefore, out of the light output from the light-emitting element 4, the light that enters the light-shielding rib 75 and the light-shielding rib 724 is easily reflected to the light-emitting element 4 side along the optical axis Ax1 of the light-emitting element 4 by the light-shielding rib 75 or the light-shielding rib 724. Therefore, the light incident on the light-shielding rib 75 and the light-shielding rib 724 is difficult to diffuse in the sensing space Sp1.

Here, as shown in FIG. 11A, in a plan view, the projection amount L1 of the light-shielding ribs 75, 724 from the optical axis Ax1 of the light-emitting element 4 toward the light-shielding wall 74 is greater than that of the light-shielding ribs 75, 724 from the optical axis Ax1 of the light-emitting element 4. The amount of protrusion L2 to the side opposite to the light shielding wall 74 is small (L1<L2). Specifically, when viewed from the optical axis Ax1 of the light-emitting element 4, the light-shielding ribs 75 and 724 are arranged at a position deviated from the light-shielding wall 74 in the circumferential direction of the wall structure 3. In short, in a plan view, the light-shielding ribs 75 and 724 are formed asymmetrically with respect to the optical axis Ax1 of the light-emitting element 4.

As shown in FIG. 11B, the light-shielding ribs 75 and 724 of the above-described structure are located in the path Op2 of light output by the light-emitting element 4 and reflected on the inner surface 700 of the sensing housing 7 more than once and then incident on the light-receiving element 5 , Op3. That is, at least a part of the light output from the light-emitting element 4 and reflected on the inner surface 700 of the sensing housing 7 after being incident on the light-receiving element 5 is shielded by the light-shielding ribs 75 and 724 of the light-shielding structure 70.

Without the light-shielding ribs 75 and 724, the light passing through the passages Op2 and Op3 is reflected on the pair of inner bottom surfaces 731 and 725 included in the inner surface 700 of the sensing housing 7 and sometimes enters the light receiving element 5. In the smoke sensor 1 of the present embodiment, since the light shielding rib 75 is located on such a passage Op2, the light passing through the passage Op2 can be shielded by the light shielding rib 75, so that the generation of "stray light" can be suppressed. The passage Op3 is also similarly located on the passage Op3 by the light-shielding rib 724, so the light passing through the passage Op3 can be shielded by the light-shielding rib 724, so that the generation of "stray light" can be suppressed.

In addition, in a plan view, although the emission port 804 is also output to the light-shielding wall 74 (please refer to FIG. 7), such light is shielded by the light-shielding wall 74, so it is difficult to form stray light. Therefore, as in this embodiment, in plan view, even if the light-shielding ribs 75 and 724 are arranged at positions offset to the opposite side of the light-shielding wall 74 when viewed from the optical axis Ax1 of the light-emitting element 4, the light-shielding ribs 75 can also be used. 724 fully suppresses the generation of "stray light".

(3) Modifications The smoke sensor 1 of Embodiment 1 is only one of various embodiments of the present disclosure. If the smoke sensor 1 of the first embodiment can achieve the purpose of cost disclosure, various changes can be made according to the design. Hereinafter, a modification example of the first embodiment will be listed. The modified examples described below can be used in appropriate combinations.

In the first embodiment, although the wall structure 3 is formed by an assembly of a large number of small pieces 30, it is not limited to this structure, and the wall structure 3 may be a continuous "wall" in the circumferential direction. In this case, since the wall structure 3 has a large number of smoke passage holes 33 penetrating the wall structure 3 in the thickness direction, a function of allowing smoke to pass in the thickness direction and suppressing light transmission can be realized.

In addition, in Embodiment 1, although the structure in which the sensing block 10 is housed in the internal space of the frame 2 is shown, it is not limited to this structure. For example, at least a part of the sensing block 10 protrudes from the frame 2. structure. In addition, the frame 2 is not a necessary structure in the smoke sensor 1, and can be omitted as appropriate.

In addition, in the first embodiment, although the case in which the sensing housing 7 and the sensing space Sp1 are both circular in plan view, it is not limited to this structure. The sensing housing 7 or the sensing space Sp1 can also be, for example, It is oval or polygonal in plan view. In this case, the wall structure 3 is also oval or polygonal in plan view.

In addition, in Embodiment 1, although a part of the light-emitting element holder 8 is arranged to be exposed from the inner surface 31 of the wall structure 3 into the sensing space Sp1, it is not limited to this structure, and the entire light-emitting element holder 8 can be accommodated in Between the inner surface 31 and the outer surface 32. The light-receiving element holder 9 can also be stored between the inner surface 31 and the outer surface 32 in the same manner.

In addition, in the first embodiment, although most of the small pieces 30 are formed integrally with the bottom plate 73 so as to protrude from the inner bottom surface 731 of the bottom plate 73, it is not limited to this structure, and the majority of the small pieces 30 may be separate members from the bottom plate 73. For example, most of the small pieces 30 can be fixed to the bottom plate 73 by adhesion or fitting. In this case, although a large number of small pieces 30 are scattered, in this case, a large number of small pieces 30 also constitute one wall structure 3.

In addition, the light-emitting element 4 is not limited to a light-emitting diode, and may be, for example, an organic EL (Electro-Luminescence) element or a laser diode (LD: Laser Diode). The light receiving element 5 is not limited to a photodiode, and may be, for example, a photoelectric crystal or the like.

In addition, the lead protruding from the bottom surface 43 or the lead passing through the wire hole 801 of the light-emitting element holder 8 only needs to be electrically connected to the lead terminal of the light-emitting element 4, and is not limited to the lead terminal 402, and may be, for example, electrically connected to the lead terminal 402. The wires and so on.

In addition, the pair of lead terminals 402 is not limited to the structure protruding from the bottom surface 43, and may protrude from surfaces other than the bottom surface 43 in the main body portion 401, such as the light emitting surface 41 or the back surface 42.

In addition, the light-shielding structure 70 can be located on the path of light that is output by the light-emitting element 4 and reflected on the inner surface 700 of the sensing housing 7 more than once and then enters the light-receiving element 5, or it can be located after the inner surface 700 is reflected many times. In the path of the light incident on the light receiving element 5.

In addition, the light-shielding structure 70 is not limited to a structure that completely shields light, and may be a structure that reduces the amount of light passing through the light-shielding structure 70.

In addition, the light-shielding structure 70 including the light-shielding sheet 802 and the light-shielding ribs 75 and 724 is not an essential structure in the smoke sensor 1, and the light-shielding sheet 802 or the light-shielding ribs 75 and 724 can be omitted, for example. In addition, when the light-shielding structure 70 includes light-shielding ribs, the light-shielding structure 70 may have light-shielding ribs 75, 724 protruding from at least one of the pair of inner bottom surfaces 731, 725, or only one of the light-shielding ribs 75, 724 may be omitted. By.

In addition, the shape of each of the light-shielding ribs 75 and 724 is not limited to the shape of a flat plate perpendicular to the optical axis Ax1 of the light-emitting element 4, and may be, for example, a curved plate or a polygonal column shape. In addition, the positions and shapes of the light-shielding rib 75 and the light-shielding rib 724 in plan view may be different.

(Embodiment 2) As shown in FIG. 12, the shape of the wall structure 3 of the smoke sensor 1A of this embodiment is different from the smoke sensor 1 of the first embodiment. Hereinafter, the same configuration as that of the first embodiment will be given the same reference numerals, and the description will be omitted as appropriate.

As shown in FIG. 12, in a plan view of the smoke sensor 1A, almost no space is generated between the outer periphery of the inner bottom surface 731 of the bottom plate 73 of the first housing 71 and the outer side surface 32 of the wall structure 3. In addition, in this embodiment, the auxiliary light shielding wall 76 is omitted (please refer to FIG. 7). In addition, the shape of each small piece of the plurality of small pieces 30 constituting the wall structure 3 is also different from the smoke sensor 1 of the first embodiment. FIG. 12 is a plan view of the state where the second housing 72 is removed, that is, the sensing block 10 of the second housing 72 is omitted. In addition, in FIG. 12, the inner surface 31 and the outer surface 32 are represented by imaginary lines (two dotted lines), and halftone dots (dot shading) are added to the area corresponding to the wall structure 3.

In addition, in the smoke sensor 1A, the appearance shape of the light-emitting element 4 is also different from the smoke sensor 1 of the first embodiment. However, in this embodiment, the light-emitting element 4 is a so-called side-view type light-emitting diode that outputs light to the side when the surface (bottom surface 43) from which the lead terminal 402 protrudes faces downward. The light emitting element 4 is arranged between the inner surface 31 and the outer surface 32 of the wall structure 3 with the light exit surface 41 facing the inner surface 31 side.

In addition, FIG. 13 shows a smoke sensor 1B according to a modification of the second embodiment. The wall structure 3 of the smoke sensor 1B shown in FIG. 13 is provided in the second housing 72 instead of the first housing 71. FIG. 13 is a plan view of the state where the second housing 72 is removed, that is, the sensing block 10 of the second housing 72 is omitted. Therefore, in FIG. 13, the wall structure 3 is indicated by a virtual line (two-dot dashed line). In addition, in FIG. 13, the inner surface 31 and the outer surface 32 are represented by imaginary lines (two dotted dotted lines), and halftone dots (dot shading) are added to the area corresponding to the wall structure 3. In addition, in the example of FIG. 13, the light shielding wall 74 is also provided in the second housing 72 together with the wall structure 3. In the smoke sensor 1B with such a structure, in a state where the first housing 71 and the second housing 72 are coupled to each other, they are arranged in a plan view to enclose the sensing space Sp1 like the smoke sensor 1A Wall structure 3.

The structure (including the modification example) of the second embodiment can be used in appropriate combination with the structure (including the modification example) described in the first embodiment.

(Embodiment 3) As shown in FIGS. 14A and 14B, the shape of each of the small pieces 30 constituting the wall structure 3 of the smoke sensor 1C of the present embodiment is different from that of the smoke sensor 1A of the second embodiment. In FIGS. 14A and 14B, a part of the light output by the light-emitting element 4 is schematically shown by a broken line. Fig. 14B is an enlarged view of area Z1 in Fig. 14A. Hereinafter, the same configuration as that of the second embodiment will be given the same reference numerals, and the description will be omitted as appropriate.

As shown in FIG. 14A, in this embodiment, at least a part of the plurality of small chips 30 on the surface facing the sensing space Sp1, that is, the surface on which the direct light from the light emitting element 4 enters, includes a concave curved surface 303. Here, among the many small pieces 30, only the small piece 30 at a position where the direct light from the light-emitting element 4 enters, that is, the small piece 30 located substantially on the front surface of the light-emitting element 4 has a concave curved surface 303. The concave curved surface 303 is curved into, for example, a part of a parabola or a part of an ellipse in a plan view.

In addition, FIGS. 15A and 15B are plan views schematically showing a part of the light output from the light-emitting element 4 in the smoke sensor 1A of the second embodiment with broken lines. It can be seen from FIGS. 15A and 15B that when the small piece 30 has no concave curved surface 303, when a part of the light output from the light-emitting element 4 is incident on any small piece 30, the light is reflected by the small piece 30. As shown in FIG. 15B, the light reflected by any small piece 30 is reflected toward the small piece 30 adjacent to the small piece 30. At this time, the small piece 30 forms substantially parallel light relative to the small piece 30, and the incident light is still reflected as substantially parallel light. As a result, as shown by the passage Op4 in FIGS. 15A and 15B, a part of the light is reflected by the plurality of small pieces 30 and enters the light-receiving element 5, forming the so-called "stray light", which becomes the smoke sensor 1A. Elements of reduced sensing accuracy.

In contrast, according to the smoke sensor 1C of this embodiment, when a part of the light output from the light-emitting element 4 enters any small piece 30, the light is reflected by the concave curved surface 303 of the small piece 30. As shown in FIG. 14B, the light reflected by the concave curved surface 303 of any small piece 30 is reflected toward the small piece 30 adjacent to the small piece 30. At this time, the concave curved surface 303 acts to condense the light incident on the concave curved surface 303 to form a substantially parallel light. As a result, the light from the light emitting element 4 that enters the small piece 30 can be enclosed between a pair of adjacent small pieces 30. Therefore, compared with the example of FIG. 15A and FIG. 15B, the "stray light entering the light receiving element 5" can be reduced. ". Therefore, the smoke sensor 1C of the present embodiment can suppress the increase of stray light even though the detection accuracy is improved.

As a modification of the third embodiment, at least a part of the plurality of small pieces 30 has another (second) concave curved surface other than the concave curved surface 303 on the back surface of the concave curved surface 303, that is, the surface facing the opposite side of the concave curved surface 303. In this structure, the reflected light reflected by the concave curved surface 303 is further condensed by the second concave curved surface, so that the light from the light emitting element 4 that enters the small chip 30 is easily enclosed between a pair of adjacent small chips 30. Therefore, the "stray light" incident on the light receiving element 5 can be further reduced, thereby suppressing the increase of stray light even though the sensing accuracy is improved.

The structure (including the modification example) of the third embodiment can be used in appropriate combination with the structure (including the modification example) described in the first and second embodiments.

(Embodiment 4) As shown in FIG. 16, the light-shielding wall 74 of the smoke sensor 1D of the present embodiment has many small walls 741 and 742, which is different from the smoke sensor 1 of the first embodiment in this respect. In FIG. 16, halftone dots (dot shading) are added to the light-irradiated area A1 of the light-emitting element 4 and the light-receiving area A2 of the light-receiving element 5. The area where the irradiated area A1 and the light-receiving area A2 overlap becomes a sensing area A3 in the sensing space Sp1 that is particularly helpful for smoke sensing. In addition, in FIG. 16, the single light-shielding wall 74 in the first embodiment is represented by a virtual line (two-dot dashed line). Hereinafter, the same configuration as that of the first embodiment will be given the same reference numerals, and the description will be omitted as appropriate.

In this embodiment, the light shielding wall 74 has two small walls 741 and 742 of the (first) small wall 741 and the (second) small wall 742. That is, in a plan view, a large number of small walls 741 and 742 constituting the light-shielding wall 74 are arranged on a straight line connecting the light-emitting element 4 and the light-receiving element 5. The plurality of small walls 741 and 742 have the function of shielding the direct light from the light-emitting element 4 to the light-receiving element 5.

Specifically, in plan view, compared to the single light-shielding wall 74 in the first embodiment, the small wall 742 is arranged at a position close to the light-emitting element 4. Thereby, the small wall 742 mainly has the function of shielding a part of the light output by the light-emitting element 4 and narrowing the irradiated area A1. On the other hand, in plan view, compared to the single light-shielding wall 74 in the first embodiment, the small wall 741 is arranged at a position close to the light-receiving element 5. Thereby, the small wall 741 mainly has the function of shielding a part of the light incident on the light receiving element 5 and narrowing the light receiving area A2.

According to the smoke sensor 1D of this embodiment, it can be ensured that the center point P1 of the sensing space Sp1 where the optical axis Ax1 of the light-emitting element 4 intersects the optical axis Ax2 of the light-receiving element 5 to the light-shielding wall 74 (small wall 741 , 742) is relatively large. That is, compared to the single light-shielding wall 74 in the first embodiment, most of the small walls 741 and 742 can be respectively arranged at positions away from the center point P1. Therefore, the freedom of disposition of the light shielding wall 74 in the sensing space Sp1 is high.

As a modification of the fourth embodiment, the light-shielding wall 74 may have three or more small walls.

The structure (including the modification example) of the fourth embodiment can be used in appropriate combination with the structure (including the modification example) described in the first to third embodiments.

(to sum up) As explained above, the smoke sensors 1, 1A to 1D of the first aspect have: a sensing housing 7, a light-emitting element 4, a light-receiving element 5, and a light-shielding structure 70. The sensing housing 7 surrounds the sensing space Sp1. The light emitting element 4 outputs light to the sensing space Sp1. The light-receiving element 5 is arranged at a position where the direct light from the light-emitting element 4 does not enter and the scattered light generated by the smoke in the sensing space Sp1 enters. The light shielding structure 70 protrudes from the inner surface 700 of the sensing housing 7 into the sensing space Sp1. The sensing housing 7 includes a wall structure 3 that allows smoke to pass through and prevents light from passing through. The light-shielding structure 70 is located on the paths Op1, Op2, Op3 of the light output from the light-emitting element 4 and reflected on the inner surface 700 of the sensing housing 7 more than once and then incident on the light-receiving element 5.

According to this aspect, at least a part of the light output from the light-emitting element 4 and reflected on the inner surface 700 of the sensing housing 7 and then incident on the light-receiving element 5 is shielded by the light-shielding structure 70. Therefore, compared with the structure without the light-shielding structure 70, the light output from the light-emitting element 4 is less likely to enter the light-receiving element 5 after being reflected on the inner surface 700 of the sensing housing 7. Therefore, for example, even if dirt or foreign matter invades the sensing housing 7, the possibility that part of the light output by the light emitting element 4 is reflected to the light receiving element 5 on the inner surface 700 of the sensing housing 7 is reduced. . As a result, the reflected light on the inner surface 700 of the sensing housing 7 is difficult to enter the light receiving element 5. Therefore, although the sensing accuracy of the smoke sensors 1, 1A to 1D is improved, the increase of stray light can be suppressed.

The smoke sensors 1, 1A to 1D of the second aspect are in the first aspect, and the sensing housing 7 has a light-emitting element holder 8 for holding the light-emitting element 4. The light-shielding structure 70 includes a light-shielding sheet 802 protruding from the light-emitting element holder 8.

According to this aspect, at least a part of the light-shielding sheet 802 of the light-shielding structure 70 can be arranged near the light-emitting element 4, so that the light-shielding structure 70 can be miniaturized.

The smoke sensors 1, 1A to 1D of the third aspect are in the second aspect, and the light-shielding sheet 802 is located around the exit 804 in the light-emitting element holder 8 where the light from the light-emitting element 4 is emitted.

According to this aspect, at least a part of the light-shielding sheet 802 of the light-shielding structure 70 can be arranged closer to the light-emitting element 4, so that the light-shielding structure 70 can be more compact.

The smoke sensors 1, 1A to 1D of the fourth aspect are in any of the first to third aspects, and the half-value angle q1 of the light-emitting element 4 is 25 degrees or more.

According to this aspect, because the light-emitting element 4 is a relatively wide-angle element, the light-emitting element 4 can cover a relatively wide range of the sensing space Sp1, and therefore the sensing accuracy of the smoke sensors 1, 1A to 1D can be improved.

The smoke sensors 1, 1A to 1D of the fifth aspect are in any of the first to fourth aspects, viewed from a direction orthogonal to the inner bottom surface 731 of a flat bottom plate 73, surrounded by a wall structure 3 Sensing space Sp1. The sensing housing 7 has a pair of inner bottom surfaces 731 and 725 facing each other in a direction. The light-shielding structure 70 includes light-shielding ribs 75 and 724 protruding from at least one of the pair of inner bottom surfaces 731 and 725.

According to this aspect, the light output from the light emitting element 4 can be suppressed from spreading in a direction perpendicular to a plane (the inner bottom surface 731 of the bottom plate 73).

The smoke sensors 1, 1A to 1D of the sixth aspect are in the fifth aspect, and the light-shielding ribs 75, 724 are located on the inner surface of at least one of the pair of inner bottom surfaces 731, 725 that are output by the light-emitting element 4 On Op2 and Op3, the path of light.

According to this aspect, the detection accuracy of the smoke sensors 1, 1A to 1D can be suppressed from being reduced by the light output from the light emitting element 4 and reflected by at least one of the inner bottom surfaces 731 and 725.

The smoke sensors 1, 1A to 1D of the seventh aspect are in the fifth or sixth aspect. They are viewed from a direction orthogonal to the inner bottom surface 731 of a flat bottom plate 73. The light-shielding ribs 75, 724 are arranged in contact with the light-emitting The position where the optical axis Ax1 of element 4 overlaps.

According to this aspect, the light from the light emitting element 4 can be easily shielded by the light shielding ribs 75 and 724.

The smoke sensors 1, 1A to 1D of the eighth aspect are in the seventh aspect, and the light-shielding ribs 75 and 724 have a shape extending in a direction crossing the optical axis Ax1 of the light-emitting element 4.

According to this aspect, the light output from the light-emitting element 4 that enters the light-shielding ribs 75 and 724 is easily reflected to the side of the light-emitting element 4 along the optical axis Ax1 of the light-emitting element 4 by the light-shielding ribs 75 and 724. Therefore, it is difficult for the light entering the light shielding ribs 75 and 724 to diffuse in the sensing space Sp1.

The smoke sensors 1, 1A to 1D of the ninth aspect are in the eighth aspect, and have a view from a direction perpendicular to a plane (the inner bottom surface 731 of the bottom plate 73), and are arranged to connect the light-emitting element 4 and The light-shielding wall 74 on the straight line of the light receiving element 5. Viewed from a direction orthogonal to a plane, the projection amount L1 of the light-shielding ribs 75, 724 from the optical axis Ax1 of the light-emitting element 4 to the side of the light-shielding wall 74 is greater than that of the light-shielding ribs 75, 724 from the optical axis Ax1 of the light-emitting element 4. The amount of protrusion L2 on the opposite side of the wall 74 is small.

According to this aspect, the gap between the light-shielding ribs 75 and 724 and the light-shielding wall 74 can be ensured to be relatively wide, and therefore the degree of freedom of the arrangement of the light-shielding wall 74 is high.

The second to ninth aspects are not necessary structures in the smoke sensors 1, 1A to 1D, and can be omitted as appropriate.

1. 1A~1D‧‧‧Smoke sensor 2‧‧‧Frame 3‧‧‧Wall structure 4‧‧‧Light-emitting element 5‧‧‧Light receiving element 7‧‧‧Sensing shell 8‧‧‧Light-emitting component bracket 9‧‧‧Light-receiving element holder 10‧‧‧Sensing block 20‧‧‧Circuit block 21‧‧‧First cover 22‧‧‧Second cover 23‧‧‧Opening 30‧‧‧Small film 31‧‧‧Inside 32‧‧‧Outer side 33‧‧‧Smoke through hole 41‧‧‧Light emitting surface 42‧‧‧Back 43‧‧‧Bottom 61‧‧‧Sound output 62‧‧‧Battery 63‧‧‧Screw 70‧‧‧Shading structure 71‧‧‧First shell 72‧‧‧Second shell 73‧‧‧Bottom plate 74‧‧‧Shading Wall 75‧‧‧(first) light-shielding rib 76‧‧‧Auxiliary shading wall 81‧‧‧First bracket 82‧‧‧Second bracket 201‧‧‧Printed Wiring Board 202‧‧‧Electronic parts 211‧‧‧First Main Board 212‧‧‧The first wall 213‧‧‧Circuit area 214‧‧‧First audio area 215‧‧‧ button 216‧‧‧ditch 217‧‧‧Sound hole 221‧‧‧Second Main Board 222‧‧‧Second Wall 223‧‧‧Containment area 224‧‧‧Second sound zone 225‧‧‧Battery area 226‧‧‧Separator 301, 302‧‧‧end edge 303‧‧‧Concave surface 401, 501‧‧‧Main body 402、502‧‧‧Lead terminal 403‧‧‧Lighting part 404‧‧‧Lead part 411‧‧‧flat part 412‧‧‧Protrusion 503‧‧‧Metal cover 700‧‧‧Inside 711, 712‧‧‧claw 721‧‧‧Upper board 722‧‧‧ Zhoubi 723‧‧‧window hole 724‧‧‧(Second) Shading Rib 725‧‧‧(Second) inner bottom surface 731‧‧‧(first) inner bottom surface 741、742‧‧‧Small wall 801‧‧‧Through hole 802‧‧‧Shading film 803‧‧‧Positioning surface 804‧‧‧Ejection outlet Ax1, Ax2‧‧‧Optical axis A1‧‧‧ Irradiation area A2‧‧‧Light receiving area A3‧‧‧Sensing area C1‧‧‧Centerline L1, L2‧‧‧Projection Op1, Op2, Op3, Op4‧‧‧path P1‧‧‧Center point Sp1‧‧‧Sensing space Z1‧‧‧area q1‧‧‧Half value angle

[Fig. 1] Fig. 1 is a perspective view of a part of the sensing block of the smoke sensor according to the first embodiment. [Figure 2] Figure 2A is a perspective view of the same smoke sensor as seen from below. Figure 2B is a perspective view of the same smoke sensor as seen from above. [Figure 3] Figure 3 is an exploded perspective view of the same smoke sensor as seen from below. [Figure 4] Figure 4 is an exploded perspective view of the same smoke sensor as seen from above. [Fig. 5] Fig. 5 is a perspective view of a part of the same smoke sensor as above. [Figure 6] Figure 6 is an exploded perspective view of the sensing block of the same smoke sensor. [Fig. 7] Fig. 7 is a plan view of the same smoke sensor with the sensing block of the second housing removed. [Figure 8] Figure 8A is a plan view of the same smoke sensor with the second housing removed. FIG. 8B shows the main part of the same smoke sensor, and is an enlarged view of the area Z1 in FIG. 8A. [Fig. 9] Fig. 9 shows the main part of the same smoke sensor, and is an enlarged cross-sectional view of the area Z1 in Fig. 5. [Fig. 10] Fig. 10 shows the main part of the same smoke sensor, and is an end view of the line A1-A1 in Fig. 7. [Fig. 11] Fig. 11A is a plan view of the main part of the same smoke sensor with the second housing removed from the sensing block. Fig. 11B is an end view showing the main part of the same smoke sensor. [Fig. 12] Fig. 12 is a plan view of the smoke sensor in the second embodiment with the sensing block removed from the second housing. [Fig. 13] Fig. 13 is a plan view of the smoke sensor in the second modification of the second embodiment with the sensor block removed. [Fig. 14] Fig. 14A is a plan view of the smoke sensor in the third embodiment with the sensing block removed from the second housing. Fig. 14B is an enlarged view of area Z1 in Fig. 14A. [Fig. 15] Fig. 15A is a plan view of the smoke sensor in the second embodiment with the sensing block removed from the second housing. FIG. 15B is an enlarged view of area Z1 in FIG. 15A. [Fig. 16] Fig. 16 is a plan view of the smoke sensor of the fourth embodiment with the sensing block removed from the second housing.

1‧‧‧Smoke sensor

3‧‧‧Wall structure

4‧‧‧Light-emitting element

7‧‧‧Sensing shell

8‧‧‧Light-emitting component bracket

10‧‧‧Sensing block

30‧‧‧Small film

70‧‧‧Shading structure

71‧‧‧First shell

72‧‧‧Second shell

73‧‧‧Bottom plate

75‧‧‧(first) light-shielding rib

81‧‧‧First bracket

82‧‧‧Second bracket

402‧‧‧Lead terminal

700‧‧‧Inside

721‧‧‧Upper board

722‧‧‧ Zhoubi

724‧‧‧(Second) Shading Rib

725‧‧‧(Second) inner bottom surface

731‧‧‧(first) inner bottom surface

802‧‧‧Shading film

804‧‧‧Ejection outlet

Sp1‧‧‧Sensing space

Claims (8)

A smoke sensor includes: a sensing housing, which surrounds a sensing space; a light-emitting element, which outputs light to the sensing space; and a light-receiving element, which is arranged so that direct light from the light-emitting element will not enter, and because of the The position where the scattered light generated by the smoke in the sensing space will enter; and the light-shielding structure, which protrudes from the inner surface of the sensing housing into the sensing space; wherein the sensing housing has: a wall structure to allow The smoke passes through and inhibits light transmission; and a light-emitting element holder that holds the light-emitting element; the light-shielding structure is different from the light-shielding wall arranged on the straight line connecting the light-emitting element and the light-receiving element, and is provided separately. The light-emitting element is output and reflected by the inner surface of the sensing housing for more than one time and then is incident on the light path of the light-receiving element; and the light-shielding structure includes a light-shielding sheet protruding from the light-emitting element support, the light-shielding sheet The light-emitting element holder is located on the side of the exit port from which the light from the light-emitting element is emitted, and the exit port is located on the side opposite to the light-shielding wall when viewed from the exit port. For example, the smoke sensor of item 1 in the scope of patent application, wherein the light-shielding sheet is located around the ejection outlet. For example, the smoke sensor of item 1 or 2 of the scope of patent application, wherein the half angle of the light-emitting element is 25 degrees or more. For example, the smoke sensor of item 1 or 2 of the scope of patent application, wherein: viewed from a direction perpendicular to a plane, the wall structure surrounds the sensing space, The sensing housing has a pair of inner bottom surfaces facing each other in the one direction, and the light shielding structure includes a light shielding rib protruding from at least one of the pair of inner bottom surfaces. Such as the smoke sensor of item 4 of the scope of patent application, wherein the light-shielding rib is located on the path of light output from the light-emitting element and incident on at least one inner surface of the pair of inner bottom surfaces. For example, in the smoke sensor of item 4 of the scope of patent application, the light-shielding rib is arranged at a position overlapping with the optical axis of the light-emitting element when viewed from the one direction perpendicular to the one plane. For example, in the smoke sensor of item 6 of the scope of patent application, the light-shielding rib has a shape extending in a direction intersecting the optical axis of the light-emitting element. For example, the smoke sensor of item 7 of the scope of patent application, wherein the light-shielding wall is arranged on the straight line connecting the light-emitting element and the light-receiving element when viewed from the direction orthogonal to the plane; Viewed from the one direction, the amount of protrusion of the light shielding rib from the optical axis of the light emitting element toward the side of the light shielding wall is greater than the amount of protrusion of the light shield rib from the optical axis of the light emitting element toward the side opposite to the light shielding wall small.

Images