Optical chamber for smoke detection with reflective surfaces

Abstract

Described herein are apparatuses, systems, and methods for providing a smoke detector. A smoke detector for a fire sensing system includes a circuit board body having a set of front-scatter emitter light sources located on one side of an optical chamber, a receiver of front-scatter light beams and back-scatter light beams from the front-scatter emitter light sources, and a set of back-scatter emitter light sources located between the set of front-scatter emitter light sources and the receiver, the back-scatter light beams emitted from the back-scatter emitter.

Description

Technical Field

[0001] This disclosure relates to apparatus, systems, and methods for providing an optical chamber for smoke detection using a reflective surface. Background Technology

[0002] Facilities (e.g., buildings) (such as commercial facilities, office buildings, hospitals, etc.) may have fire detection systems that can be triggered during emergencies (e.g., fire) to warn occupants to evacuate. For example, a fire detection system may include a fire alarm control panel within the building and multiple smoke detectors located throughout the facility (e.g., on different floors and / or in different rooms of the facility) that can sense smoke conditions indicating a fire in the facility and provide smoke condition notifications to occupants and / or building monitoring personnel via alarms or other mechanisms.

[0003] Such detectors can use pre-configured optical blocks, which, in the case of detecting a single forward-scattered signal, consist only of:

[0004] Transmitter;

[0005] Receiver; and

[0006] One or more plastic parts used to house and align optical components.

[0007] Various types of such optical configurations are currently being utilized.

[0008] These optical blocks are integrated into the system, which also includes printed circuit boards (PCBs) for electrical connections between the optical transmitters and receivers, as well as other mechanical parts (e.g., plastic covers) that guide smoke particles toward the detection zone and complete the configuration of the sensing chamber for sensing fire conditions.

[0009] In a previous embodiment, the transmitter and receiver were carried by a plastic optical block that provided a fixed orientation and barrier between them. The optical block, with its transmitter, receiver, and metal shielding, constitutes a surface-mount device (SMD) that can be placed on a printed circuit board via an automated assembly process using multiple pick-and-place areas. While the optical block SMD configuration is advantageous compared to manually soldered optical transmitters and receivers, it represents a custom SMD component with low scalability (e.g., it is very difficult to integrate additional detection based on, for example, backscattering by adding other SMD components), and its pick-and-place process is complex and prone to generating rejection components.

[0010] In another prior art configuration, two prisms (one for light emission and one for light reception), typically made of transparent resin material, are positioned in a guide hole along the light emission axis: the two prisms are adapted to the emitter and receiver, respectively. The two prisms have total reflection surfaces and lenses, causing light to be guided and concentrated into and from the sensing area.

[0011] This prior configuration has the advantage of allowing the use of standard and commercial surface-mount transmitters and receivers mounted on printed circuit boards using standard surface mount technology (SMT); it ensures the function of guiding light to and collecting light from smoke particles through two prisms with a total reflective surface and a lens. However, this optical system is essentially composed of disparate parts, including two prisms and a box-shaped body with dedicated guide holes covering them. This prior design offers the convenience of using commercial surface-mount transmitters and receivers, but it has a higher number of components (at least one dedicated body and two prisms in addition to the surface-mount transmitter and receiver), and is therefore perhaps not desirable. Attached Figure Description

[0012] Figure 1 This is an exploded view of a smoke detector according to one or more embodiments of the present disclosure.

[0013] Figure 2 This is a cross-sectional view of the interior of a smoke detector according to one or more embodiments of this disclosure.

[0014] Figure 3 This is a top perspective view of a smoke detector for a fire alarm system constructed according to one or more embodiments of the present disclosure, wherein the detector cover and optical chamber cover are removed.

[0015] Figure 4 It is the front side of the circuit board of a smoke detector for a fire alarm system according to one or more embodiments of this disclosure.

[0016] Figure 5 This is a bottom perspective view of a circuit board cover for a smoke detector used in a fire alarm system, constructed according to one or more embodiments of this disclosure.

[0017] Figure 6 This is a top perspective view of a circuit board cover for a smoke detector used in a fire alarm system, constructed according to one or more embodiments of this disclosure.

[0018] Figure 7 It is a close-up perspective view of a backscattering module constructed according to one or more embodiments of the present disclosure.

[0019] Figure 8This is a close-up front perspective view of a transmitter unit constructed according to one or more embodiments of the present disclosure.

[0020] Figure 9 This is a close-up bottom perspective view of a transmitter unit constructed according to one or more embodiments of the present disclosure.

[0021] Figure 10 This is a close-up side perspective view of a transmitter unit constructed according to one or more embodiments of the present disclosure.

[0022] Figure 11 This is a bottom-up close-up view of a transmitter module constructed according to one or more embodiments of this disclosure.

[0023] Figure 12 This is a bottom-up close-up view of a receiver module constructed according to one or more embodiments of this disclosure.

[0024] Figure 13 This is a close-up top perspective view of an optical cavity module constructed according to one or more embodiments of the present disclosure.

[0025] Figure 14 This is a cross-sectional view of the interior of a smoke detector with a backscatter receiver according to one or more embodiments of the present disclosure. Detailed Implementation

[0026] This document describes apparatus, systems, and methods for providing an optical chamber for smoke detection using a reflective surface. This disclosure relates to optical smoke detectors or multi-standard smoke detectors that use optical systems to detect light scattered by smoke particles: these systems typically include a sensing chamber (in which particles enter), an optical transmitter and receiver, and electronic control circuitry for the operating system.

[0027] The embodiments disclosed herein aim to overcome the above-mentioned problems by providing a solution that integrates the simplicity of the assembly process (e.g., SMT, minimizing the number of mechanical parts), scalability for bi-angle / dual-wavelength (2A / 2W) optical detection, cost-effectiveness while maintaining good optical sensitivity, and / or high immunity to interference sources.

[0028] In this detailed description, reference is made to the accompanying drawings, which form a part thereof. The drawings illustrate, by way of example, how one or more embodiments of this disclosure can be practiced.

[0029] These embodiments are described in sufficient detail to enable one or more embodiments of this disclosure to be practiced by a person skilled in the art. It should be understood that other embodiments may be utilized and process, electrical and / or structural changes may be made without departing from the scope of this disclosure.

[0030] It should be understood that elements shown in the various embodiments herein may be added, exchanged, combined, and / or eliminated to provide multiple additional embodiments of this disclosure. The scale and relative dimensions of the elements provided in the accompanying drawings are intended to illustrate embodiments of this disclosure and should not be construed as limiting.

[0031] The figures in this document follow the following numbering convention: one or more first digits correspond to the figure number, while the remaining digits identify elements or parts in the figure. Similar elements or parts between different figures can be identified by using similar digits. For example, 102 can be referenced... Figure 1 The element "02" in the text, and Figure 2 Similar elements in the text can be referenced as 202.

[0032] As used in this article, "one" or "several" can refer to one or more such things, while "multiple" can refer to more than one such thing. For example, "numerous components" can refer to one or more components, while "multiple components" can refer to more than one component.

[0033] Figure 1 This is an exploded view of a smoke detector according to one or more embodiments of this disclosure. Figure 1 In the illustrated embodiment, the smoke detector 100 includes a detector cover 102, an optical chamber cover 104, a circuit board cover 106, a circuit board 108 (shown here as having a surface-mount thermistor 112 disposed at a corner of the circuit board), and a detector base 110. When assembled, the smoke detector is depicted as... Figure 2 In the sectional view.

[0034] The assembly process of a smoke detector, including an optical chamber with a reflective surface, may include, for example, different stages such as the following:

[0035] 1. Assemble SMT circuit boards;

[0036] 2. Place the circuit board on the detector base;

[0037] 3. Cover the circuit board with a circuit board cover having a reflective surface;

[0038] 4. Place the chamber cover on the circuit board cover;

[0039] 5. Install smoke detector covers;

[0040] 6. Programming, calibrating, and pre-packaging testing of the smoke detector microcontroller; and

[0041] 7. Encapsulate the smoke detector.

[0042] Figure 2This is a cross-sectional view of the interior of a smoke detector according to one or more embodiments of this disclosure. (As...) Figure 1 , Figure 2 The smoke detector 200 shown includes a detector cover 202, an optical chamber cover 204, a circuit board cover 206, a circuit board 208, and a detector base 210.

[0043] A transmitter reflector 220 is also shown, in which a set of forward-scattering emitters 218 (e.g., surface-mount emitters) are positioned within module 225 below the reflector 220 as part of the transmitter reflector module 225. A set of backscattering emitters 216 (e.g., surface-mount emitters) are also provided positioned within a backscattering cavity 222 formed within a backscattering module 221. Additionally, a receiver 214 (e.g., a surface-mount receiver) is positioned below a receiver reflector 244 as part of a receiver module 223.

[0044] Optical chambers (such as those used for smoke detection using reflective surfaces) can be used. Figure 1 and Figure 2 And optical chambers (as shown in other embodiments discussed herein) are integrated into many current optoelectronic-based smoke detector designs. In some embodiments, the unique optical chamber with a reflective surface, as discussed herein, can be formed from three parts:

[0045] - A circuit board (e.g., circuit board 108 / 208), wherein, for example, surface mount device components (e.g., four SMD emitters (two forward scatterers and two back scatterers) and one SMD receiver are mounted using, for example, a standard SMT assembly process;

[0046] - Circuit board covers with reflective surfaces (e.g., the lower portion of an optical chamber, such as 106 / 206); and

[0047] - Chamber covering (e.g., the upper part of the optical chamber, such as 104 / 204).

[0048] An exemplary embodiment of this disclosure includes a smoke detector for a fire sensing system, the smoke detector comprising a circuit board body having: a set of forward-scattering emission sources located on one side of an optical chamber; a receiver for a forward-scattering beam and a backscattering beam, the forward-scattering beam originating from the forward-scattering emission sources; and a set of backscattering emission sources located between the set of forward-scattering emission sources and the receiver, the backscattering beam being emitted from the backscattering emitters.

[0049] Figure 3This is a top perspective view of a smoke detector for a fire alarm system constructed according to one or more embodiments of this disclosure, wherein the detector cover and optical chamber cover are removed. Provided Figure 3 Therefore, the reader can see the assembly structure (i.e., the circuit board cover 306, the circuit board 308 (shown here as having a surface-mount thermistor 312 disposed at a corner of the circuit board), and the detector base 310). Based on this view, some structures within the backscattering module 321 can be seen. The following is relative to... Figure 7 These features are discussed in more detail, but this figure provides context related to the location of the backscattering module 321.

[0050] Figure 4 This refers to the front side of a circuit board for a smoke detector in a fire alarm system according to one or more embodiments of this disclosure. Preferably, the printed circuit board integrates the transmitter, receiver, and all the electronic circuitry required to drive the transmitter and collect, analyze, and / or transmit information from the receiver to the control panel of the fire system (located away from the detector device).

[0051] To implement a dual-angle / dual-wavelength configuration, a single receiver and four transmitters (e.g., an infrared 411 and a blue 413 transmitter for forward optical scattering, and an infrared 417 and a blue 415 transmitter for back optical scattering) can be used. Figure 4 Such an embodiment is illustrated, wherein the printed circuit board 408 includes a set of forward scattering emitters 418 (411 and 413) and a set of backscattering emitters 416 (417 and 415) and a receiver 419 disposed on the printed circuit board.

[0052] The electronic circuitry pulses one transmitter at a time, and the radiation scattered by smoke from that transmitter is collected by the receiver, thereby generating a corresponding optical signal. During a cycle (e.g., 4 seconds), all four transmitters pulse sequentially (e.g., per second), thereby generating four distinct optical signals at the receiver (e.g., infrared forward scattering (IRFS), blue forward scattering (blue FS), infrared backscattering (IR BS), and blue backscattering (blue BS)). As used herein, suitable infrared wavelength transmitters are in the range of 700 nm to 1 mm, and suitable blue wavelength transmitters are in the range of 400 to 525 nm.

[0053] Smoke detectors are essential components in some types of fire detection systems. Similarly important is the controller that provides detection analysis, alarm functions, and communication with other fire system devices. A printed circuit board 408 designed according to embodiments of this disclosure can provide these functions in a single integrated circuit board. The signals discussed above from the receiver can be stored in memory and / or analyzed by the controller on or connected to the printed circuit board to determine, for example, whether a fire condition exists near the detector.

[0054] The data type obtained by dedicated software in the firmware of the controller and / or stored in memory can be volatile integer data representing the amount of particles detected in the optical chamber of the smoke detector. Alternatively, this data can be stored in random access memory (RAM) and used for fire alarm generation, or stored at the application level in non-volatile RAM (NVRAM) for diagnostic purposes such as evaluating particle density using different types of algorithms (e.g., averaging, modal, etc.). This layer can be, for example, located at the fire system control panel.

[0055] exist Figure 4 The illustrated embodiment also shows a surface-mount thermistor 412 disposed at a corner defined by the edge of the printed circuit board 408. This approach reduces cost, shortens manufacturing time, and decreases complexity, among other benefits. The embodiment shows apertures formed near the corner. These apertures thermally insulate the thermistor from the rest of the circuit board. This is important because the thermistor is sensing temperature, and the circuit board is generating heat that could produce erroneous readings at the thermistor.

[0056] Any number of orifices can be provided. Figure 4 There are two openings with a bridge between them, allowing circuitry to cross the bridge and connect the thermistor to other circuitry on the board.

[0057] Figure 5 This is a bottom perspective view of a circuit board cover for a smoke detector used in a fire alarm system, constructed according to one or more embodiments of this disclosure.

[0058] The circuit board cover 506 integrates unique optical components that guide and focus radiation from the four emitters and scattered by the smoke. These optical components are not prisms or lenses, but rather reflective surfaces (520 and 524) of the circuit board cover 506 or one or more modules mounted therein. Figure 5 Modules 523, 521 and 525 in the module have appropriate shapes, sizes and positions to guide light from the light source as needed.

[0059] The geometry of these reflective surfaces is unique to embodiments of this disclosure. The geometry of the emitter reflector structure includes a double-tilted elliptical reflector (emitter reflector), which reflects light from two adjacent forward-scattering emitters (e.g., Figure 4 The emitter reflector 511, 413) collects the light beam and guides it toward the receiver (e.g., 419) through the central region of the smoke chamber. The emitter reflector 520 consists of two elliptical sections, each tilted (e.g., ±5 degrees) relative to the optical axis. This relationship is shown in more detail in… Figure 11 In addition, the elliptical receiver reflector 524 collects the radiation scattered by the smoke particles and directs it to the device receiver (e.g., Figure 4 (419) on.

[0060] Figure 6 This is a top perspective view of a circuit board cover for a smoke detector used in a fire alarm system, constructed according to one or more embodiments of this disclosure. Figure 5 and Figure 6 As shown, the backscattering (BS) cavity module 621 ( Figure 5 The cavity (521) separates the two forward-scattering emitters and the receiver. This cavity provides several functions, including: preventing direct illumination of the receiver and hosting the backscattering emitters (e.g., one infrared and one blue). For these reasons, the backscattering cavity has barriers to limit the propagation of the beam generated by the backscattering emitters and apertures emitting the infrared and blue radiation beams. Figure 7 and Figure 13 These features can be seen in more detail in the image.

[0061] exist Figure 6 In one embodiment, the backscattering cavity module 621 is positioned within a circuit board cover 606. The body of the circuit board cover can be made entirely of a highly reflective plastic material (e.g., polycarbonate (PC), metallized acrylonitrile butadiene styrene (ABS)). This can provide several benefits, such as: simplified manufacturing process (no need to install parts, such as reflectors), reduced parts (no separately mounted reflectors), lower costs, improved measurement consistency (molded parts will be more consistent), and good optical efficiency. However, in other embodiments, the body can be made of a plastic material on which a highly reflective metal (e.g., aluminum, chromium, etc.) is deposited to maximize optical efficiency.

[0062] The body of the circuit board cover can also be made of different materials, using a multi-material molding process to maximize reflectivity only on the surfaces used to guide light from the emitter to the scattering area and focus light from the scattering area to the receiver. In some implementations, other surfaces not required for guiding or focusing light may be black or another suitable surface color / texture to absorb light and minimize unwanted reflections.

[0063] Figure 7 This is a close-up perspective view of a backscattering module constructed according to one or more embodiments of this disclosure. Figure 7 In the illustrated embodiment, the backscattering module 721 forms a cavity therein to house the backscattering emitter 716. Similarly, as described above, the module is configured to have a barrier 728 (e.g., two "V"-shaped barriers) and apertures 726 (e.g., two apertures) that emit infrared and blue radiation beams. These structural features control the direction in which the beam generated by the backscattering emitter travels within the detector.

[0064] Figure 8 This is a close-up front perspective view of a transmitter unit constructed according to one or more embodiments of the present disclosure. Figure 8 The illustrated embodiment shows how module 825 has a reflective housing in which cavity 840 is formed. Emitters 811 and 813 emit light beams into cavity 840, and the inner surface of the housing of module 825 guides the light in a predictable manner into the optical cavity (central scattering region) of the detector device. From this description, it can be inferred that the shape of the reflective inner surface can be used to alter the direction of the emitted light. For example, to integrate two forward-scattering emitters (e.g., IR and blue) into a smoke chamber, a double-elliptical reflector that guides the light from both emitters in the central scattering region can be utilized. For example, each portion of the ellipse can be positioned relative to the optical axis (e.g., ...). Figure 9 The optical axis (932) is offset and tilted by 5 degrees.

[0065] Figure 9 This is a close-up bottom perspective view of a transmitter unit constructed according to one or more embodiments of the present disclosure. Figure 9 A module 925 with a housing having an elliptical inner surface 942 is shown, the elliptical inner surface being used to guide a beam 934 in a direction 936 at an angle relative to the optical axis 932. As described above, this angle can be changed by altering the shape of the inner surface 942.

[0066] Because this surface is a single, integral part of module 925, the accuracy between detector components can be more precise than with a design that uses one or more mirror surfaces to achieve beam reflection. Furthermore, if these parts are formed through a molding process, the surfaces of identical parts produced by the molding process can be nearly identical, which also increases the predictability of the detection.

[0067] Figure 10 This is a close-up side perspective view of a transmitter unit constructed according to one or more embodiments of the present disclosure. Figure 10 A module 1025 with a housing is shown, the housing having a cavity 1040 formed therein, such as Figure 8 and Figure 9 As also shown. In this illustration, the light beam is tilted upwards from the X-axis at an angle of 1038 degrees (e.g., 30 degrees) based on the reflective inner surface of the housing. As mentioned above, the inner surface can be designed differently to change the angle at which the light is tilted relative to the X-axis. As shown, the tilt angle of the beam can be slightly scattered, but the beam can be configured to be within a threshold amount from the desired tilt angle (e.g., 10 degrees plus or minus 30 degrees).

[0068] Figure 11 This is a bottom-up close-up view of a transmitter module constructed according to one or more embodiments of this disclosure. Figure 11 In the figure, the dual-emitter structure of the internal reflective surface 1120 of the transmitter module 1125 housing can be seen. As shown, the entire surface 1120 has two main sections, each designed to correspond to a respective transmitter (e.g., Figure 8 The 811 and 813 interact. In this way, a module can be created that can precisely guide a beam from multiple emitting sources. Furthermore, Figure 11 , Figure 12 and Figure 13 The modular design of these modules depicted allows for precise positioning on the circuit board cover (e.g., Figure 6 Within the 606), and thus precisely located within the detector, resulting in more accurate smoke detection and more reliable fire detection.

[0069] For example, such as Figure 5 As can be seen, the fixing devices within the circuit board cover structure can be shaped to precisely fit the transmitter, receiver, and optical cavity module. Figure 5 523, 521, and 525 in the middle and Figure 11 , Figure 12 and Figure 13 The shapes of 1223, 1321, and 1125 in the model are used. In this way, the modules can be precisely positioned relative to each other and other components of the detector.

[0070] Figure 12 This is a bottom-up close-up view of a receiver module constructed according to one or more embodiments of the present disclosure. In this illustration, module 1223 has an inner housing surface 1224 shaped to guide the received light beam into the interior of a cavity within the housing to reach the receiver (e.g., Figure 4 (419). As described above, the inner surface can be shaped differently depending on, for example, the angle at which the light beam is received and based on the position of the receiver relative to the reflective inner surface.

[0071] Figure 13This is a close-up top perspective view of an optical cavity module constructed according to one or more embodiments of the present disclosure. The illustration shows a module housing a backscattering emitter (e.g., Figure 4 The module 1321 is the optical cavity 1322 of the emitters 415 and 417. As described above, the module can be shaped to fit into a specific location in the circuit board cover. For example, in the illustrated embodiment, module 1321 has a plus sign shape (when viewed from above). Figure 5 The circuit board cover (and modules 523 and 525 when positioned in cover 506) has a corresponding shape, wherein when the plus-shaped module is placed therein, it is precisely positioned in the cover and relative to the transmitter and receiver and their mirror module surfaces.

[0072] In some implementations, at least two of the following are integrated modules: a forward-scattering emitter module, a backscattering emitter module, and a receiver module. For example, such as Figure 5 As shown, units 521, 523 and 525 may be an integral piece that can be positioned in the circuit board cover 506, or alternatively, modules 523 and 521 or 525 and 521 may be integral and may be positioned in the cover 506 with the remaining modules during assembly.

[0073] Figure 14 This is a cross-sectional view of the interior of a smoke detector with a backscatter receiver according to one or more embodiments of the present disclosure. In this embodiment, the backscatter receiver 1444 (e.g., a surface-mount receiver) may be positioned, for example, within a backscatter cavity formed within a backscatter module. The module may be similar to... Figure 2 and Figure 3 The module shown (e.g., Figure 2 221 and Figure 3 (321). In this embodiment, the top of the backscattering module may have a single aperture on the top surface, instead of Figure 3 The multiple apertures shown are used to irradiate the smoke in the optical chamber when an infrared or blue emitter illuminates it. The radiation is then diverted by the smoke particles (…). Figure 14 The backscattering receiver 1444 (located in the backscattering cavity) receives the scattered light at an angle of 70°±10 relative to the principal axis (x, y, z) of the transmitter radiation, while the frontscattering receiver 1414 receives the scattered light at an angle of 140°±15 relative to the principal axis of the transmitter radiation.

[0074] To implement a dual-angle / dual-wavelength configuration, two receivers and two transmitters can be used (e.g., Figure 4The system is configured with an infrared 411 and a blue 413 transmitter, a receiver 1414 for forward optical scattering and a receiver 1444 for backward optical scattering. Figure 14 Such an implementation is shown, wherein the printed circuit board includes two transmitters 1418 (e.g., Figure 4 (411 and 413), backscatter receiver 1444 and forward scatter receiver 1414 disposed on the printed circuit board.

[0075] The electronic circuit pulses one transmitter at a time, and two receivers, 1414 and 1444, collect the radiation scattered by smoke from that transmitter, thereby generating a corresponding optical signal. During a cycle (e.g., 2 seconds), the two transmitters pulse sequentially (e.g., per second), thereby generating four different optical signals (e.g., infrared forward scattering (IR FS), blue forward scattering (blue FS), infrared backscattering (IR BS), and blue backscattering (blue BS)) at the two receivers.

[0076] In some implementations, the backscattering (BS) cavity module ( Figure 5 521) can be positioned to separate the two transmitters 1418 and receiver 1414. The cavity can provide several functions, including: preventing direct illumination of the forward-scattering receiver and hosting the backscattering receiver. For these reasons, the backscattering cavity can have a barrier to limit the propagation of the beam generated by the transmitter and an aperture at its top to limit the field of view of the backscattering receiver.

[0077] The backscattering module can form a cavity therein to house the backscattering receiver 1444. Similarly, as described above, the module can be configured to have barriers (e.g., two "V"-shaped barriers) and an aperture for the backscattering receiver 1444 to collect infrared and blue backscattered radiation. These features can be used to control the direction of backscattered radiation collection.

[0078] As discussed, by using embodiments of this disclosure, smoke detectors can be made more reliable, easier to manufacture, and more cost-effective to produce, with greater consistency and fewer chances of human error among manufactured devices, and can be more accurate in detecting smoke particles in airflows. Such features can be highly beneficial in detecting fires in their early stages and warning emergency personnel and building occupants, among other benefits.

[0079] Although specific embodiments have been illustrated and described herein, those skilled in the art will understand that any arrangement calculated to achieve the same technology may replace the specific embodiments shown. This disclosure is intended to cover any and all modifications or variations of the various embodiments of this disclosure.

[0080] It should be understood that the above description is given in an illustrative rather than restrictive manner. Combinations of the above embodiments, as well as other embodiments not specifically described herein, will be apparent to those skilled in the art upon reading the above description.

[0081] The scope of the various embodiments of this disclosure includes any other application using the structures and methods described above. Therefore, the scope of the various embodiments of this disclosure should be determined with reference to the appended claims and the full scope of their equivalents.

[0082] In the above specific embodiments, for the purpose of simplifying this disclosure, various feature structures are combined in the example embodiments shown in the drawings. This disclosure method should not be construed as reflecting an intention to require more feature structures than expressly recited in each claim.

[0083] Conversely, as reflected in the following claims, the subject matter of the invention lies in fewer than all the features and structures of a single disclosed embodiment. Therefore, the following claims are incorporated herein by reference, wherein each claim exists independently as a separate embodiment.

Claims

1. A smoke detector (200) for a fire sensing system, comprising: a circuit board body (208) having: a set of forward scattering emission light sources (218) located on one side of an optical chamber; a receiver (214) of forward scattering light beams and backscattering light beams, the forward scattering light beams being from the forward scattering emission light sources (218); and a set of backscattering emission light sources (216) located between the set of forward scattering emission light sources (218) and the receiver (214), the backscattering light beams being emitted from the backscattering emission light sources (216); a circuit board cover (206) mounted over the set of forward scattering emission light sources (218), the set of backscattering emission light sources (216), and the receiver (214); a forward scattering emission module (225) placed within the circuit board cover (206) having a reflective surface formed on an inner surface of the forward scattering emission module (225), and wherein the reflective surface is positioned over the set of forward scattering emission light sources (218) and reflects the forward scattering light beams toward an optical cavity formed between the circuit board body (208) and the circuit board cover (206); a receiver module (223) placed within the circuit board cover (206) having a reflective surface formed on an inner surface of the receiver module (223), and wherein the reflective surface is positioned over the receiver (214) and reflects the forward scattering light beams toward the receiver (214); and a securing device within the circuit board cover (206) shaped to precisely fit the shape of the forward scattering emission module (225) and the receiver module (223); wherein the reflective surface of the forward scattering emission module (225) comprises a double tilted elliptical mirror.

2. The smoke detector (200) of claim 1, wherein the set of forward scattering emission light sources (218) comprises at least one infrared emission light source.

3. The smoke detector (200) of claim 1, the set of forward scattering emission light sources (218) comprises at least one blue emission light source.

4. The smoke detector (200) of claim 1, the set of backscattering emission light sources (216) comprises at least one infrared emission light source.

5. The smoke detector (200) of claim 1, the set of backscattering emission light sources (216) comprises at least one blue emission light source.

6. The smoke detector (200) of claim 1, wherein the circuit board cover (206) comprises a reflective surface positioned over the set of forward scattering emission light sources (218), the reflective surface reflecting the forward scattering light beams toward an optical cavity formed between the circuit board body (208) and the circuit board cover (206).

7. The smoke detector (200) of claim 6, wherein the circuit board cover (206) includes a reflective surface positioned above the receiver (214), the reflective surface reflecting the forward scattered light beam and the backscattered light beam from an optical cavity formed between the circuit board body (208) and the circuit board cover (206) toward the receiver (214).

8. The smoke detector (200) of claim 7, wherein the circuit board cover (206) includes a backscatter housing positioned above the set of backscatter emission light sources (216), the backscatter housing limiting a direction in which the backscattered light beam can travel after being emitted from the backscatter emission light sources (216).

9. The smoke detector (200) of claim 1, wherein the circuit board cover (206) includes a reflective surface positioned above the receiver, the reflective surface reflecting the forward scattered light beam and the backscattered light beam from an optical cavity formed between the circuit board body (208) and the circuit board cover (206) toward the receiver (214).

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