JP2019207650A - Smoke detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a smoke sensor which can be downsized. SOLUTION: A smoke detector is attached to a mounting surface and has a housing in which a smoke detecting space for detecting smoke is formed, a light emitting section 6A for irradiating the smoke detecting space with light, and a light emitting section for emitting light. A light receiving portion 6B that receives the light scattered in the smoke detection space, and a substrate 6 that is provided inside the housing so as to be horizontal to the mounting surface and on which the light emitting portion and the light receiving portion are mounted are provided. At least one of the light emitting unit and the light receiving unit is a chip component surface-mounted on the substrate, and the optical axis of the chip component is parallel to the substrate. [Selection diagram] Fig. 5

Description

  The present invention relates to a smoke detector that detects smoke generated in a fire or the like.

  Conventionally, as smoke detectors that detect smoke generated by fires, etc., when smoke enters the smoke detection space, the light emitted from the light emitting part is scattered by the smoke, and the light reaches the light receiving part. There is known a photoelectric smoke detector that senses light. Patent Document 1 discloses a smoke detector that is a chip component that is mounted on a mounting surface such as a ceiling and has a light emitting portion and a light receiving portion mounted on a surface of a substrate. In Patent Document 1, the substrate is provided in a direction perpendicular to the mounting surface.

Japanese Patent No. 5562097 (for example, FIG. 7)

  However, in the smoke detector disclosed in Patent Document 1, the height of the entire smoke detector is increased because the substrate is attached in a direction perpendicular to the surface to be attached. For this reason, downsizing of the smoke detector is desired.

  The present invention solves the above-described problems and provides a smoke detector that can be miniaturized.

  A smoke detector according to the present invention is attached to a surface to be mounted, and has a casing in which a smoke detection space for detecting smoke is formed, a light emitting unit for irradiating light to the smoke detection space, and a light emitting unit. A light receiving portion that receives light scattered in the smoke detection space, and a substrate that is provided inside the housing so as to be horizontal to the mounting surface and on which the light emitting portion and the light receiving portion are mounted. At least one of the light receiving portions is a chip component that is surface-mounted on the substrate, and the optical axis of the chip component is in a direction parallel to the substrate.

According to the present invention, the substrate is provided horizontally on the mounting surface. For this reason, the height of the smoke detector can be kept low. Therefore, the smoke detector can be reduced in size.
In addition, if the optical axis of the chip component is in a direction perpendicular to the substrate, the smoke detection space increases in the height direction. However, in the present invention, the optical axis of the chip component is parallel to the substrate. There is no need to increase the height of the space, and the smoke detector can be miniaturized.

It is an assembly perspective view which shows the smoke detector 100 which concerns on Embodiment 1 of this invention. It is a top view which shows the smoke detector 100 which concerns on Embodiment 1 of this invention. It is a side view which shows the smoke detector 100 which concerns on Embodiment 1 of this invention. It is a disassembled perspective view which shows the smoke detector 100 which concerns on Embodiment 1 of this invention. It is a perspective sectional view showing smoke detector 100 according to Embodiment 1 of the present invention. 1 is a top cross-sectional view showing a smoke detector 100 according to Embodiment 1 of the present invention. It is side surface sectional drawing which shows the smoke detector 100 which concerns on Embodiment 1 of this invention, and is a figure which shows 6 A of light emission parts. It is side surface sectional drawing which shows the smoke detector 100 which concerns on Embodiment 1 of this invention, and is a figure which shows the light-receiving part 6B. FIG. 7 is a top sectional view showing the smoke detector 100 according to Embodiment 1 of the present invention, and is an enlarged view of FIG. 6. It is a top view which shows the board | substrate 6 of the smoke detector 100 which concerns on Embodiment 1 of this invention. It is sectional drawing which showed typically the positional relationship of the board | substrate 6, the smoke detection space 33, and the optical bench 4A in the smoke detector 100 which concerns on Embodiment 1 of this invention.

Embodiment 1 FIG.
Hereinafter, embodiments of a smoke detector according to the present invention will be described with reference to the drawings. FIG. 1 is an assembled perspective view showing a smoke detector according to Embodiment 1 of the present invention, FIG. 2 is a top view showing the smoke detector according to Embodiment 1 of the present invention, and FIG. It is a side view which shows the smoke detector which concerns on Embodiment 1 of this invention. 4 is an exploded perspective view showing the smoke detector according to Embodiment 1 of the present invention, and FIG. 5 is a perspective sectional view showing the smoke detector according to Embodiment 1 of the present invention. These are top surface sectional views which show the smoke detector which concerns on Embodiment 1 of this invention. 6 is a cross-sectional view taken along the line AA in FIG.

  As shown in FIGS. 1 to 6, the smoke detector 100 is installed in a monitoring space such as the interior of a house, for example, a mounting surface such as a ceiling. In addition, the smoke detector 100 includes a housing 10 including a bottomed cylindrical first cover 11 and a base portion 12 provided on the back side of the first cover 11. The smoke detector 100 is housed in a housing 10, and a main body 3 that vertically divides a space in the housing 10, a lid portion 4 provided on the main body 3, and an optical platform provided on the lid portion 4. The cover 5 and the labyrinth wall which is accommodated in the optical stand cover 5 and has a light shielding function are provided. Further, a smoke detection space 33 for detecting smoke is formed inside the housing 10, and this will be described in detail later.

  Further, the smoke detector 100 includes a substrate 6 provided between the main body 3 and the lid 4, a battery that supplies operating power for various circuits provided on the substrate 6, and a speaker that outputs sound and the like. 8 and. The substrate 6 is surface-mounted with a light emitting unit 6A that emits light to the smoke detection space 33 that detects smoke, and a light receiving unit 6B that receives light emitted from the light emitting unit 6A and scattered in the smoke detection space 33. ing.

  An opening 1 extending in the circumferential direction is formed in the first cover 11 of the housing 10. The openings 1 are formed in two rows in the vertical direction. The opening 1 communicates with the smoke passage in the housing 10. In addition, the first cover 11 has an annular corner connecting the flat bottom surface portion 11A in which the push button opening 11A1 is formed, the cylindrical side surface portion 11B, and the bottom surface portion 11A and the side surface portion 11B. 11C. Further, the lower surface portion 11 </ b> A faces the main body 3.

The base portion 12 of the housing 10 is provided on the upper portion of the first cover 11. The smoke detector 100 can be fixed to the surface to be attached by fixing the base portion 12 to the ceiling surface or wall surface that is the surface to be attached using screws or the like. The main body 3 includes a wall portion 3A in which a smoke detection space 33 into which smoke from the smoke passage flows is formed and an upper surface portion 3B to which the upper end of the wall portion 3A is connected. Further, the main body 3 is opened on the base portion 12 side so that a battery can be inserted, and a concave battery housing portion 3C for housing the battery and a concave speaker housing formed of an annular wall in which the speaker 8 is housed. Part 3D.
In FIG. 4, a printed circuit board installation unit 3P is provided on the left side of the speaker housing 3D. This printed circuit board installation part 3P is a wall having a predetermined height in the same manner as a partition wall 3E2 described later, and is formed in a substantially U shape in accordance with the shape of the substrate 6, and in the space of the substrate 6 The mounting surface side is stored. The board | substrate 6 is installed on the printed circuit board installation part 3P and the partition wall 3E2. The height of the wall of the printed circuit board installation portion 3P is high enough to accommodate a shield case 6F described later.

  The wall 3A is provided with a substrate 6 in a part of the periphery. The wall portion 3A includes a wall portion a, a wall portion b, a wall portion c, and a wall portion d. The wall a is connected to one end of the wall c and one end of the wall d. The wall part b is connected to the other end part of the wall part c and the other end part of the wall part d. The wall c is formed with a first hole 31 through which light emitted from the light emitting unit 6A passes, and the wall d is formed with a second hole 32 through which light received by the light receiving unit 6B passes. ing. Further, the wall 3A is provided with a pair of protrusions 34 as light shielding columns that prevent the straight light from the light emitting part 6A from entering the light receiving part 6B.

  The main body 3 includes a partition wall 3E1 that partitions the side on which the battery is disposed and the side on which the substrate 6 is provided. In other words, the substrate 6 is provided on the upper surface 3B side of the main body 3, and the battery is provided on the back side thereof. The main body 3 includes a partition wall 3E2 connected to the wall 3A. A substrate 6 (a part of the substrate having the light emitting portion) is provided immediately below the lower end of the partition wall 3E2. The partition wall 3E2 has a function of blocking light from the light emitting unit 6A. Here, the partition wall 3E2 and the substrate 6 are separate bodies. Therefore, a gap is formed between the lower end of the partition wall 3E2 and the mounting surface 6a that is the upper surface of the substrate 6. The smoke detector 100 includes a light blocking unit 30 having a light blocking function so that light from the light emitting unit 6A does not leak from the gap.

  The light shielding unit 30 is a plate-like member that extends in the vertical direction. That is, the light shielding portion 30 extends to the lower side of the slit 6E. That is, when the substrate 6 is mounted on the partition wall 3E2 or the like of the main body 3, the light shielding unit 30 has such a height that the lower end of the light shielding unit 30 can slightly protrude from the lower surface (back surface 6b) of the substrate 6. . For this reason, even if it tries to look at the light emission part 6A from the clearance gap between the lower end of the partition wall 3E2, and the mounting surface 6a which is the upper surface of the board | substrate 6, the light emission part 6A is hidden by the light shielding part 30. In this way, by providing the light shielding part 30, the light from the light emitting part 6A to the light receiving part 6B can be shielded outside the wall part 3A. Further, light from the light emitting unit 6A is prevented from leaking from a gap between the lower end of the partition wall 3E2 and the mounting surface 6a that is the upper surface of the substrate 6, and light is prevented from leaking to the light receiving unit 6B side.

  For example, a flat plate-like member can be used for the light shielding unit 30. The light shielding portion 30 is formed so as to protrude from the smoke detection space 33 side to the substrate 6 side. The light shielding unit 30 is provided in the light emitting unit 6A. That is, the distance from the light shielding unit 30 to the light emitting unit 6A is shorter than the distance from the light shielding unit 30 to the light receiving unit 6B. The light shielding unit 30 is connected to the wall 3A so that light from the light emitting unit 6A does not leak from the boundary between the light shielding unit 30 and the wall 3A. The light shielding portion 30 is connected to a connection portion between the wall portion b and the wall portion c. The light shielding unit 30 extends in parallel with, for example, the optical axis of the light emitting unit 6A.

  The lid 4 includes an optical bench 4A on which an optical bench cover 5 is provided, and a through hole 4B formed in the optical bench 4A. An optical bench cover 5 and a labyrinth wall are provided below the optical bench 4A. Further, a smoke detection space 33, a substrate 6 and a wall 3A are provided on the upper side of the optical bench 4A (see FIG. 11). The through hole 4 </ b> B communicates the space inside the optical bench cover 5 with the smoke detection space 33. Moreover, the cover part 4 is provided with the wall part accommodating part 4C which accommodates wall part 3A etc. FIG. The wall portion accommodating portion 4C is formed so that the inside thereof is slightly larger than the wall portion 3A and the like, and is provided around the wall portion 3A and the like. The optical bench cover 5 is a flat member. A cylindrical insect screen is provided on the upper part of the optical bench cover 5. The insect net has a plurality of holes through which smoke passes. A labyrinth wall is accommodated inside the optical bench cover 5 and the insect net.

  The board | substrate 6 is provided in parallel to the horizontal direction on to-be-attached surfaces, such as a ceiling surface. The base portion 12 is attached horizontally to the surface to be attached, and the main body 3 is attached so as to be horizontal with the base portion 12. The substrate 6 is attached so as to be horizontal with the main body 3. Therefore, the board | substrate 6 is provided in the to-be-attached surface in parallel with the horizontal direction. The substrate 6 includes an optical system arrangement unit 6C on which the light emitting unit 6A and the light receiving unit 6B are arranged. The optical system arrangement portion 6C is a concave cutout portion formed in accordance with the circumferential shape of the wall portion 3A. The optical system arrangement portion 6C is provided around the wall portion 3A. Specifically, the optical system arrangement portion 6C is provided on the outer peripheral surface of the wall portion b, the outer peripheral surface of the wall portion c, and the outer peripheral surface of the wall portion d. The optical system arrangement unit 6C includes a light emitting unit arrangement unit 6D1 in which the light emitting unit 6A is arranged and a light receiving unit arrangement unit 6D2 in which the light receiving unit 6B is arranged (see FIG. 9). Further, the substrate 6 is formed with a slit 6E into which the light shielding portion 30 is inserted (see FIG. 10). The slit 6 </ b> E has a shape that matches the horizontal cross-sectional shape of the light shielding portion 30. The substrate 6 includes an amplifier circuit that amplifies the signal detected by the light receiving unit 6B, and a control device (not shown) that is, for example, a microcomputer that controls the operation of the light emitting unit 6A and the light receiving unit 6B. Is provided.

The light emitting unit 6A can be composed of, for example, an LED. In addition, the light receiving unit 6B can be composed of, for example, a photodiode. The light emitting unit 6 </ b> A and the light receiving unit 6 </ b> B are placed on the mounting surface 6 a of the substrate 6. That is, the light emitting unit 6A and the light receiving unit 6B are chip components that do not have lead wires. More specifically, the light emitting unit 6A includes a chip type LED, and the light receiving unit 6B includes a chip type photodiode. Thereby, the board | substrate 6 can be reduced in thickness. Note that at least one of the light emitting unit 6A and the light receiving unit 6B may be a chip component. More specifically, the light emitting part 6A and the light receiving part 6B, which are chip parts, do not have lead wires and are directly installed on the substrate 6, so that the protruding height from the substrate 6 is low. Since the height of the chip component itself is substantially the same as the thickness of the substrate 6, the size of the optical system comprising the pair of light emitting elements and light receiving elements of the smoke detector can be reduced.
The light emitting unit 6 </ b> A and the light receiving unit 6 </ b> B are chip components that are surface-mounted on a substrate, and the optical axes of these chip components are parallel to the mounting surface 6 a of the substrate 6. Further, a smoke detection space 33 is present in front of the light emitting portion 6A through the first hole portion 31. In other words, as shown in FIG. 11, the smoke detection space 33 and the optical system are provided on substantially the same plane and have the same relationship in the height direction. Although the height of the wall 3A is the height of the smoke detection space 33, when the substrate 6 is installed in the printed circuit board installation unit 3P, the height from the upper surface 3B of the main body 3 to the back surface 6b of the substrate 6 is detected. It is formed slightly lower than the height of the smoke space 33.

  The smoke detector 100 includes a shield case 6F having a function of preventing the light receiving unit 6B from detecting noise. The shield case 6F is fixed on the substrate 6. The shield case 6F covers and protects the light receiving unit 6B, the amplifier circuit, and the control device. Since the shield case 6F has a rectangular parallelepiped box shape and can be manufactured by bending a sheet metal, the assembly is easy.

  Referring to FIG. 8, the shield case 6 </ b> F is provided so as to cover a part of the substrate 6. The shield case 6F has, for example, a box shape whose one surface is open. The shield case 6F includes a top surface portion 6F1 provided at the upper portion of the light receiving portion 6B and a front surface portion 6F2 in which a circular through hole 6F3 is formed. The top surface portion 6F1 faces the mounting surface 6a of the substrate 6. The front part 6F2 is provided between the light receiving part 6B and the wall part d. The center of the second hole portion 32 coincides with the center of the through hole 6F3. The upper end of the front portion 6F2 is connected to the top surface portion 6F1. Further, the lower end 6F4 of the front portion 6F2 extends below the surface of the substrate 6 on which the light receiving portion 6B is provided. That is, the lower end 6F4 of the front portion 6F2 extends below the mounting surface 6a. A lower end 6F4 of the front portion 6F2 extends to, for example, the back surface 6b of the mounting surface 6a of the substrate 6.

  FIG. 7 is a side cross-sectional view showing smoke detector 100 according to Embodiment 1 of the present invention, and is a view showing light emitting portion 6A. 7 is a cross-sectional view taken along line BB in FIG. As shown in FIG. 7, the light emitting portion 6 </ b> A is a chip component provided on the outer edge portion of the substrate 6. As shown in FIGS. 6 and 7, a light emission notch 40 is formed below the light emitting portion 6 </ b> A in the substrate 6. When the substrate 6 without a notch is present immediately below the light emitting portion 6A provided at the outer edge portion of the substrate 6, light irradiated downward from the light emitting portion 6A is irregularly reflected on the substrate 6 and the traveling direction of the light is determined. Absent. On the other hand, in the first embodiment, since the light emission notch 40 is formed below the light emitting portion 6A, the light irradiated downward from the light emitting portion 6A is not irregularly reflected by the substrate 6, and the light emission notch 40 is formed. Proceed downward through the road. Therefore, unnecessary irregular reflection of light can be suppressed. The light emitting part 6A made of chip parts is composed of a main body part installed on the substrate and a light emitting body that is provided in front of the main body part and emits light. The width of the light emission notch 40 is as follows. It is formed to be the same as or slightly larger than the width of the light emitter. Although the light emitting unit 6A is installed at the outer edge of the substrate 6, more specifically, as shown in FIGS. 9 and 10, only the light emitter is installed so as to be positioned on the light emission notch 40. .

  FIG. 8 is a side cross-sectional view showing the smoke detector 100 according to Embodiment 1 of the present invention, and is a view showing the light receiving unit 6B. 8 is a cross-sectional view taken along the line CC of FIG. As shown in FIG. 8, the light receiving portion 6 </ b> B is a chip component provided on the outer edge portion of the substrate 6. As shown in FIGS. 6 and 8, a light receiving notch 41 is formed in front of and below the light receiving portion 6 </ b> B in the substrate 6. Here, the shield case 6 </ b> F covers the light receiving unit 6 </ b> B, the control device, and the amplifier circuit, and the tip on the light receiving unit 6 </ b> B side is inserted into the light receiving notch 41. Thus, the area for forming the through hole 6F3 can be ensured by extending the tip of the shield case 6F on the light receiving portion 6B side.

  FIG. 9 is a top sectional view showing the smoke detector 100 according to Embodiment 1 of the present invention, and is an enlarged view of FIG. FIG. 10 is a top view showing the substrate 6 of the smoke detector 100 according to Embodiment 1 of the present invention. As described above, the substrate 6 is formed with the light emission notch 40 and the light receiving notch 41 as shown in FIGS. 9 and 10. In FIG. 10, for convenience, the positions where the light emitting unit 6A and the light receiving unit 6B are arranged are indicated by dotted lines. Here, the substrate 6 will be described with reference to FIG. The substrate 6 is formed in a substantially rectangular shape, and a large notch serving as the optical system arrangement portion 6C is formed on one end side of the long piece. This notch is formed in a substantially trapezoidal shape having a long outer side, and has a shape corresponding to the shape of the wall portion 3A. More specifically, the protruding portion 34 side that becomes a light shielding column in the wall portion 3 </ b> A engages with the notched portion of the substrate 6. In the cutout of the substrate 6, a light emission cutout 40, a light reception cutout 41, and a slit 6 </ b> E are further provided in the inner direction of the substrate 6.

  Next, the operation of the smoke detector 100 will be described. When a fire or the like occurs, smoke flows into the smoke passage through the opening 1 of the housing 10. The smoke that has flowed into the smoke passage flows into the space inside the optical bench 4 </ b> A through a hole in the insect screen in the optical bench cover 5. The smoke flowing into the space inside the optical bench 4A passes through the labyrinth wall and then flows into the through hole 4B of the lid portion 4. The smoke that has flowed into the through hole 4B flows into the smoke detection space 33. In addition, fine particles are mixed in the smoke. Because these particles are heavier than smoke, they are less likely to rise. For this reason, the particles remain on the optical bench 4 </ b> A, and only smoke flows into the smoke detection space 33. Thereby, the smoke detector 100 improves the fire detection accuracy.

  The light emitting portion 6A irradiates light into the smoke detection space 33 through the first hole portion 31. Here, most of the light emitted from the light emitting unit 6 </ b> A enters the smoke detection space 33. However, part of the light emitted from the light emitting unit 6A travels away from the optical axis of the light emitting unit 6A and does not enter the smoke detection space 33. Light that has not entered the smoke detection space 33 is blocked by the light shielding unit 30, and light that does not enter the smoke detection space 33 is prevented from leaking from the gap between the partition wall 3 </ b> E <b> 2 and the substrate 6. When smoke flows into the smoke detection space 33, the light emitted from the light emitting unit 6A is scattered by the smoke. The smoke detector 100 detects a fire when the light receiving unit 6B detects the scattered light.

  According to the first embodiment, the substrate 6 is provided horizontally with respect to the mounting surface. For this reason, the height of the smoke detector 100 can be kept low. In addition, since an optical system (light emitting unit 6A, light receiving unit 6B) provided on the substrate 6 uses a chip component that does not have a lead wire extending in the height direction of the smoke detector 100, the optical provided on the substrate 6 is used. The system hardly protrudes from the surface of the substrate 6. Therefore, the smoke detector 100 can be thinned. The light emitting portion 6A is a chip component provided on the outer edge portion of the substrate 6, and a light emission notch 40 is formed below the light emitting portion 6A on the substrate 6. When there is a substrate 6 not having a notch directly under the light emitting portion 6A, the light irradiated downward from the light emitting portion 6A is irregularly reflected on the substrate 6, and the traveling direction of the light is not determined. On the other hand, in the first embodiment, since the light emission notch 40 is formed below the light emitting portion 6A, the light emitted downward from the light emitting portion 6A is not irregularly reflected by the substrate 6 and proceeds downward as it is. To do. Therefore, the light is not blocked and unnecessary irregular reflection of the light can be suppressed. Thereby, in the optical system having the light emitting unit 6A mounted on the surface, it is possible to sufficiently secure the signal component while suppressing the noise component of the light receiving unit 6B when detecting smoke. Therefore, the S / N ratio necessary for smoke detection can be obtained. Since the conventional light emitting element is a DIP part having a lead wire, there is no need to consider irregular reflection because the distance between the light emitting element and the substrate is long. However, when the light emitting unit 6A is directly mounted on the substrate, the light emitting notch By providing 40, the problem of irregular reflection can be solved.

  In order to detect smoke with high accuracy, the height position of the light emitting unit 6A and the height position of the light receiving unit 6B may be matched. The optical axis of the light emitting part 6A and the optical axis of the light receiving part 6B extending in the horizontal direction do not necessarily have to be completely the same height, but the heights of both optical axes are substantially the same. It is desirable to do. Therefore, when the light emitting unit 6A is a chip component, it is necessary to lower the position of the light receiving unit 6B as much as the position of the light emitting unit 6A is lowered. When lowering the position of the light receiving portion 6B, it is necessary to lower the height position of the second hole portion 32 and the height position of the through hole 6F3 in accordance with the height position of the light receiving portion 6B. Here, if the lower end 6F4 of the front part 6F2 of the shield case 6F is above the mounting surface 6a of the substrate 6, the front part 6F2 may be deformed when the through hole 6F3 is formed in the front part 6F2. is there. Further, if the lower end 6F4 of the front part 6F2 of the shield case 6F is above the mounting surface 6a, there is a possibility that the through hole 6F3 cannot be formed in the front part 6F2. When the front portion 6F2 is deformed or the shape of the through hole 6F3 is deformed, the light receiving characteristics of the light receiving portion 6B change, and the smoke detector 100 cannot detect smoke with high accuracy.

  The lower end 6F4 of the front surface portion 6F2 of the shield case 6F of the smoke detector 100 according to the first embodiment extends below the surface of the substrate 6 on which the light receiving portion 6B is provided. For this reason, it can suppress that front part 6F2 deform | transforms when forming through-hole 6F3 in front part 6F2. Further, the shape of the through hole 6F3 can be more reliably set to a predetermined shape, for example, a circle. The optical axis extending in the horizontal direction of the light receiving portion 6B and the height of the through hole 6F3 provided in the shield case 6F are at the same height position. As described above, since the shield case 6F having the through-hole 6F3 can be provided in front of the light receiving unit 6B, the light receiving unit 6B can be protected from noise, and thus the smoke detector 100 has reduced smoke detection accuracy. Can be suppressed. Even if either the light emitting unit 6A or the light receiving unit 6B is not a chip component, the smoke detector 100 can obtain an effect of suppressing a decrease in smoke detection accuracy. If the part 6B is a chip component, the effect is further enhanced.

The lower end 6F4 of the front surface portion 6F2 of the shield case 6F extends below the surface of the substrate 6 where the light receiving portion 6B is provided, that is, extends downward from the mounting surface 6a. The lower end 6F4 has a length extending to the back surface 6b of the substrate 6. For this reason, even if the noise light that could not be blocked by the light blocking unit 30 enters the light receiving unit 6B through the gap between the partition wall 3E2 and the substrate 6, the noise light is detected by the light receiving unit 6B. Can be further suppressed.
Since the conventional light receiving element is a DIP part having a lead wire, since the distance between the light receiving element and the substrate is large, a through hole for the light receiving element can be freely formed in the shield case installed in front. When the light receiving part 6B is directly mounted on the light receiving part 6B, the length (height) of the shield case on the front side can be secured by providing the light receiving notch 41, and the through hole for the light receiving element can be formed without any problem. .
By the way, since the amount of light received by the light receiving unit 6B is inversely proportional to the square of the distance, the position near the end surface of the substrate 6 has the largest amount of received light in the space surrounded by the shield case 6F and the substrate 6, In terms of increasing the amount of light scattered by the smoke, it is desirable to install the light receiving unit 6B on the outer edge of the substrate 6. On the other hand, it is necessary to provide a shield case 6F in front of the light receiving unit 6B. Therefore, in the present embodiment, a light receiving notch 41 is provided in front of the portion where the light receiving portion 6B is installed in the substrate 6, and the front portion 6F2 of the shield case bent from the top surface portion 6F1 is passed through the light receiving notch 41. I did it. The width of the front portion 6F2 is slightly smaller than the width of the light receiving notch 41, and the front portion 6F2 can be inserted into the light receiving notch 41. In this way, the light receiving part 6B can be installed on the outer edge of the substrate 6, and the shield case 6F can be provided in front of the light receiving part 6B without taking up extra space. The width of the light receiving notch 41 can be appropriately changed, but has a shape wider than the width of the light emitting notch 40.

  As described above, the amount of light received by the light receiving unit 6B is inversely proportional to the square of the distance. Therefore, the position near the end surface of the substrate 6 is the largest amount of light received in the space surrounded by the shield case 6F and the substrate 6. There are many. In the first embodiment, since the light receiving part 6B is arranged on the inner side of the end face of the substrate 6, the shield case 6F is prevented from colliding with the light receiving part 6B during assembly, and the lens part of the light receiving part 6B is damaged. Can be suppressed. Furthermore, since the substrate 6 is not cut out immediately below the shield case 6F, the shielding effect of the substrate 6 is maximized, stray light from the light emitting portion 6A is not incident, and noise components can be suppressed. .

An amplifier circuit or the like is provided around the light receiving unit 6B. For this reason, the number of wirings around the light receiving unit 6B is larger than the number of wirings around the light emitting unit 6A. When the light shielding unit 30 is provided in the light receiving unit 6B, it is necessary to form a slit 6E around the light receiving unit 6B. Therefore, when the light shielding part 30 is provided in the light receiving part 6B, the wiring length around the light receiving part 6B becomes longer or the wiring pattern becomes complicated by the amount of bypassing the slit 6E. The light shielding unit 30 of the substrate 6 of the smoke detector 100 according to the embodiment is provided in the light emitting unit 6A. For this reason, the smoke detector 100 can suppress the wiring length around the light receiving unit 6B from becoming long and the wiring pattern from becoming complicated.
In the present embodiment, a smoke detector of a type generally called a fire alarm provided with a battery and a speaker has been described as an example. However, the present invention is applied to a smoke detector of a type to which power is supplied via a signal line. Can be applied.

  DESCRIPTION OF SYMBOLS 1 Opening part, 3 main body, 3A wall part, 3B upper surface part, 3C battery accommodating part, 3D speaker accommodating part, 3E1 partition wall, 3E2 partition wall, 4 lid part, 4A optical stand, 4B through-hole, 4C wall part accommodating part 5 Optical table cover, 6 substrate, 6A light emitting unit, 6B light receiving unit, 6C optical system arranging unit, 6D1 light emitting unit arranging unit, 6D2 light receiving unit arranging unit, 6E slit, 6F shield case, 6F1 top surface unit, 6F2 front unit, 6F3 through hole, 6F4 lower end, 6a mounting surface, 6b back surface, 8 speaker, 10 housing, 11 first cover, 11A bottom surface portion, 11A1 push button opening, 11B side surface portion, 11C corner portion, 12 base portion, 30 light shielding part, 31 first hole part, 32 second hole part, 33 smoke detection space, 34 projecting part, 40 light emission notch, 41 light reception notch, 100 smoke detector, Wall, b wall, c wall, d wall.

Claims (4)

A housing that is attached to the surface to be mounted and has a smoke detection space for detecting smoke;
A light emitting unit for irradiating the smoke detection space with light;
A light receiving unit that receives light emitted from the light emitting unit and scattered in the smoke detection space;
A board on which the light emitting unit and the light receiving unit are mounted;
At least one of the light emitting unit and the light receiving unit is a chip component surface-mounted on a substrate,
The optical axis of the chip component is a direction parallel to the substrate. The light emitting unit is the chip component provided on the outer edge of the substrate,
The smoke detector according to claim 1, wherein a light emission notch is formed below the light emitter of the light emitting unit on the substrate. A shield case that covers and protects the light receiving unit;
The light receiving portion is the chip component provided on the outer edge portion of the substrate,
A light receiving notch is formed in front of and below the light receiving portion of the substrate,
The shield case is
The smoke detector according to claim 1 or 2, wherein the smoke detector is inserted into the light receiving notch. A control device provided on the substrate and configured to control operations of the light emitting unit and the light receiving unit;
The shield case is
The smoke detector according to claim 3, wherein the control device is covered and protected.

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