CN212112699U - Device for detecting smoke in a compact footprint detector - Google Patents

Abstract

The present disclosure relates to an apparatus for detecting smoke within a compact footprint detector. An apparatus for detecting the presence of smoke in a small, durable smoke detector is disclosed. In particular, the present disclosure shows how to build a very compact housing around a smoke detector while keeping the reflection from the housing structure at a very low value, while meeting all other peripheral requirements of fast response to smoke and protection from ambient light. This allows light scattering measurements of very small smoke particles to be reliable in a device that is resistant to the negative effects of dust. In particular, geometrical optical elements, such as caps and optical defect elements, are disclosed.

Description

Device for detecting smoke in a compact footprint detector

The application is a divisional application of a utility model with application date of 2018, 12 and 14, application number of 201822098771.5, and name of "compact optical smoke detector system and device".

Cross Reference to Related Applications

This application is related to and claims priority from U.S. provisional application No.62/599,474 entitled "compact optical smoke detector system and apparatus" filed on 12/15 in 2017 and U.S. patent application No.16/181,878 entitled "compact optical smoke detector system and apparatus" filed on 6/11 in 2018, both of which are incorporated herein by reference in their entirety.

Technical Field

The present disclosure relates to smoke detection. More specifically, the present disclosure describes devices and techniques related to optical identification of smoke within a compact and robust detector.

Background

A smoke detector is a device that senses smoke, typically as an indicator of a fire. Commercial security devices signal a fire alarm control panel as part of a fire alarm system, while domestic smoke detectors, also known as smoke alarms, typically emit a local audible or visual alarm from the detector itself.

Smoke detectors are mounted in plastic housings, typically shaped like discs of about 150 mm (6 inches) in diameter and 25 mm (1 inch) in thickness, but vary in shape and size. Smoke can be detected optically (photo-electrically) or by physical processes (ionization), either or both of which can be used by the detector. Sensitive alarms can be used to detect and inhibit smoking in areas where smoking is prohibited. Smoke detectors in large commercial, industrial and residential buildings are typically powered by a central fire alarm system that is powered by a building power supply with a backup battery.

Domestic smoke detectors range from a single battery powered unit to several interconnected main power units with battery backup; with these interconnected units, if smoke is detected by any of the units, it will trigger even if the household power supply is off. The size of optical smoke detectors tends to be large. Accordingly, the domestic smoke detector of 900/0 employs ionisation technology.

While ionization smoke alarms are generally more sensitive to flame fires, photoelectric smoke alarms are generally more sensitive to fires that are smoldering for extended periods of time (known as "smoldering fires"). For each type of smoke alarm, the advantages it provides may be critical to the life safety in certain fire situations. A household fatal fire includes a large smoldering fire and a large amount of flames, both day and night. One cannot predict the type of fire that may occur in a home or when a fire will occur. Any acceptable smoke alarm technique must be acceptably effective for both types of fires in order to provide fire warnings at any time of day. Or at night, whether asleep or awake.

The ionising smoke detector uses a radioisotope, usually the amidi-241, to ionize air; the difference caused by smoke is detected and an alarm is generated. The smoke detector has two ionization chambers, one open to the air and one reference chamber that does not allow particles to enter. The radiation source emits alpha particles into both chambers, ionizing some of the air molecules.

A potential difference (voltage) exists between the pair of electrodes in the chamber; the charge on the ions allows current to flow. The currents in the two chambers should be the same since they are equally affected by gas pressure, temperature and source aging. If any smoke particles enter the open chamber, some ions will attach to the particles and cannot be used to carry the current in the chamber. The electronic circuit detects that a current differential has been established between the open chamber and the sealed chamber and sounds an alarm.

Photoelectric or optical smoke detectors comprise an infrared, visible or ultraviolet light source (typically an incandescent light bulb or light emitting diode), a lens and a photoelectric receiver (typically a photodiode). In point detectors, all of these components are disposed within a chamber, where a flow of air may be contained that may contain smoke from a nearby flame. In large open areas such as atrium and auditorium, beam or projected beam smoke detectors are used instead of chambers within the unit: the wall-mounted unit emits an infrared or ultraviolet beam that is either received and processed by a separate receiving and processing device, or reflected back to the receiver by a reflector.

In certain types, particularly the light beam type, light from a light source passes through the air being tested and reaches a photosensor. The absorbed light intensity is reduced by absorption due to smoke, dust in the air, or other substances; the circuit detects light intensity and if below a specified threshold, an alarm may be generated due to smoke. In other types, typically chamber types, the light is not directed towards the sensor, which is not illuminated without particles. If the air in the chamber contains particles (smoke or dust), the light is scattered and some of it reaches the sensor, triggering an alarm.

As mentioned above, ionization detectors are more sensitive to the flame phase of a flame than optical detectors, which are more sensitive to fire during the early smoldering phase. The fire safety experts and the national fire department recommend the installation of so-called combination alarms which can detect both heat and smoke, and which can also use both ionization and photoelectric processes. A combined alarm of both technologies may be incorporated in a single device, some of which even include carbon monoxide detection functionality.

Unfortunately, the size and/or footprint of optical smoke detectors makes them unusable for most domestic uses, as well as most commercial uses. The inventors of the present disclosure have identified these disadvantages and have recognized a need for a more compact, robust optical smoke detector system. That is, an optical smoke detector that is small enough to be universally used, yet robust enough to maintain a sensitive state for long periods of time.

This summary is intended to provide an overview of the subject matter of the present patent application. It is not intended to provide an exclusive or exhaustive explanation of the present disclosure. Further limitations and disadvantages of conventional and traditional approaches will become apparent to one of skill in the art, through comparison of such systems with some aspects of the present disclosure as set forth in the remainder of the present application with reference to the drawings.

SUMMERY OF THE UTILITY MODEL

Apparatus for optically detecting smoke and implementations thereof. An apparatus for detecting the presence of smoke in a small, durable smoke detector is disclosed. In particular, the present disclosure shows how to build a very compact housing around a smoke detector while keeping the reflection from the housing structure at a very low value, while meeting all other peripheral requirements of fast response to smoke and protection from ambient light. This allows light scattering measurements of very small smoke particles to be reliable in a device that is resistant to the negative effects of dust. In particular, geometrical optical elements, such as caps and optical defect elements, are disclosed.

According to one aspect, a device for detecting smoke within a compact footprint detector that propagates light substantially away from a smoke detector chamber, the device comprising: a first light source; a first photodetector disposed substantially adjacent to the first light source; non-volatile logic to perform: receiving a first signal from a first photodetector; and determining the presence of smoke from at least the received first signal; and a cap disposed substantially orthogonal to the first light source.

According to one aspect, the cap is at least partially substantially conical-like in shape.

According to one aspect, the conical cross-section of the cap is at least partially parabolic.

According to one aspect, the conical cross-section of the cap is at least partially elliptical.

According to one aspect, further comprising a first light emitting diode having a spectral intensity centered at a first wavelength λ 1.

According to one aspect, further comprising an array of optical deflecting elements arranged in a circle substantially around an outer radius of the cap.

According to one aspect, the array of optical deflection elements is substantially wing shaped.

According to one aspect, further comprising an anti-reflective coating disposed on at least one of the cap and the array of optical deflecting elements.

According to one aspect, the coating is centered at a first wavelength λ 1.

According to one aspect, further comprising a substrate, the cap mechanically coupled to the substrate.

According to one aspect, a device for detecting smoke within a compact footprint detector that propagates light substantially away from a smoke detector chamber, the device comprising: means for providing light from a first light source; means for detecting light on a first photodetector disposed proximate the first light source; means for receiving a first signal from a first photodetector; means for determining the presence of smoke based at least in part on the received first signal at least in part from the scattering particulate matter; and means for reflecting light using a cap that geometrically reflects light away from the first photodetector.

The figures illustrate exemplary smoke detector circuits and configurations. Variations of these circuits, such as changing the location of the circuits, adding or removing certain elements from the circuits, are not beyond the scope of this disclosure. The smoke detector, arrangement and complementary means shown are intended to be complementary to the support in the detailed description.

Drawings

For a fuller understanding of the nature and advantages of the present disclosure, reference should be made to the following detailed description of the preferred embodiments taken in conjunction with the accompanying drawings in which:

figure 1 illustrates a side view of an exemplary optical smoke detector boundary surface in accordance with some embodiments of the present disclosure provided herein;

fig. 2 depicts a top view of an exemplary optical smoke detector, showing operation, in accordance with one or more embodiments of the present disclosure provided herein.

Fig. 3 depicts a top view of elements forming an exemplary optical smoke detection device according to some embodiments of the present disclosure provided herein;

figure 4A illustrates a shortcoming of the prior art with respect to an optical smoke detection device in operation according to some embodiments of the present disclosure provided herein.

Figure 4B illustrates the above-described shortcomings of the prior art with respect to an optical smoke detection device in operation and elements comprised by an exemplary optical smoke detector according to some embodiments of the present disclosure provided herein;

fig. 5 depicts a top perspective view of an optical inspection die comprised by an exemplary optical smoke inspection device in accordance with some embodiments of the present disclosure provided herein;

fig. 6 depicts a side view of an optical inspection die comprised by an exemplary optical smoke inspection apparatus according to some embodiments of the present disclosure provided herein;

figure 7 illustrates an isometric view of an exemplary optical smoke detection device in operation according to some embodiments of the present disclosure provided herein;

figure 8 depicts a top view of elements forming an exemplary optical smoke detection device according to some embodiments of the present disclosure provided herein;

figure 9A illustrates a side view of an exemplary compact smoke detector cap according to some embodiments of the present disclosure provided herein;

figure 9B depicts a top view of an exemplary compact smoke detector cap according to some embodiments of the present disclosure provided herein;

figure 9C illustrates an isometric view of an exemplary compact smoke detector cap according to some embodiments of the present disclosure provided herein;

figure 10A illustrates a side view of an exemplary compact smoke detector cap according to some embodiments of the present disclosure provided herein;

figure 10B depicts a top view of an exemplary compact smoke detector cap according to some embodiments of the present disclosure provided herein;

figure 10C illustrates an isometric view of an exemplary compact smoke detector cap according to some embodiments of the present disclosure provided herein;

figure 11 illustrates a side view of an exemplary optical smoke detector boundary surface in accordance with some embodiments of the present disclosure provided herein.

Detailed Description

The present disclosure relates to smoke detection. More specifically, the present disclosure describes devices and techniques related to optical identification of smoke within a compact and robust detector.

The following description and the annexed drawings set forth in detail certain illustrative embodiments of the disclosure, which are indicative of several exemplary ways in which the various principles of the disclosure may be carried out. However, the illustrative examples are not exhaustive of the many possible embodiments of the disclosure. Other objects, advantages and novel features of the disclosure are set forth in the foregoing description of the applicable figures.

Fires may occur in various ways. The two most common forms of fire are slow smoldering flames and fast burning flames. Smoldering fires are a form of slow, low temperature, flameless combustion. These fires develop slowly and produce large amounts of smoke that are easily detected by optical smoke detectors. Smoldering fires are often initiated on upholstered furniture by a weak heat source such as a cigarette or an electrical short.

A fast burning flame develops rapidly, usually produces black smoke and toxic fumes, and has little time to escape. The characteristic temperature and heat of smoldering (typically 600 ℃) is lower compared to fast flames (typically 1500 ℃). Fast burning flames generally travel ten times faster than smoldering flames. Smoldering fires, however, release large amounts of toxic gases, such as carbon monoxide. These gases are highly flammable and can subsequently ignite in the gas phase, thereby initiating a transition to combustion.

Smoke detectors for detecting smoke by detecting scattered light by smoke particles have been generally proposed and implemented and put into practice. Such a smoke detector detects a fire as follows. The smoke detector has a dark room for storing the light emitter and the photodetector. The light emitted from the light emitter is scattered by the smoke particles flowing into the dark room, thereby generating scattered light. The photodetector receives the scattered light.

Optical smoke alarms have several systematic and operational disadvantages compared to ionization smoke alarms. In recent years, there has been proposed a smoke detector including an optical trap for suppressing noise light (light generated from light emitted from a light emitter reflected by an inner wall of a dark room) from reaching a light detector.

There are generally two types of noisy light-one caused by unwanted reflections from nearby surfaces of the light emitted by the light emitter and other ambient light leaking into the smoke chamber. Both lamps need to be avoided because the photodetector cannot determine whether the light is caused by reflection or scattering or the environment. When such smoke detectors are employed, the optical and electrical systems must be designed to avoid false triggering of noisy light. The inventors of the present disclosure have recognized how to improve on both leading edges while reducing size, cost, and increasing aesthetics.

However, in such smoke detectors, the optical trap is disposed in front of the light emitter and the photodetector. Therefore, the light emitted from the light emitter is reflected in a direction parallel to a virtual plane including the optical axis of the light emitter and the optical axis of the photodetector. Therefore, since noise light is easily incident to the light detection region, a false alarm may still occur.

Some smoke detectors use a labyrinth structure to prevent light from entering the dark room. Since the light emitted from the light emitter is reflected by the edge portion of the wall member constituting the labyrinth structure, irregular noise light is generated in an amount that cannot be sufficiently attenuated by the light trap. Therefore, noise light may enter the light detection area, thereby causing a false alarm.

In addition, in these types of smoke detectors, a plurality of light traps must be provided, and the light traps must be provided inside a labyrinth structure inside a dark room. Therefore, in either case, a large space is required for disposing the optical trap, and thus miniaturization of the smoke detector is difficult. Also, some smoke detectors include another member such as a lens in addition to the optical trap, thereby increasing the cost of manufacturing the smoke detector. In addition, light traps and/or lenses may inhibit smoke from flowing into the dark room.

In addition to the larger footprint, optical detection devices suffer validation during their service as opposed to ionization alarms. Optical smoke alarms using infrared emitter LEDs and ionization type smoke alarms are used to detect both types of fires and rely on the flow of ambient air through them. In some arrangements (as in one or more of the previous embodiments), a fan is used to facilitate the passage of air through them. However, dust and particulate matter can accumulate and contaminate certain equipment components thereof. These surfaces become more reflective in all directions so that any light falling on these surfaces can now be scattered into the photodetector in a manner similar to smoke.

Still, in some cases, optical detection systems are preferred over ionization-type systems. For example, optical systems better detect smoldering fires. Furthermore, ionization alarms have the disadvantage that they are subject to regulations regarding their manufacture and disposal, since they contain radioisotopes in the sensor. These regulations are country dependent but may place a considerable burden on manufacturers.

Optical smoke detectors tend to be large and expensive devices that reduce contamination with age, thereby creating false positives. The inventors of the present disclosure have recognized a need for a more robust optical smoke detector whose size is related to the size of ubiquitous home ionization units and which is relatively insensitive to the threat of dust and other particulate contamination. Furthermore, the optical surfaces within the chamber themselves play an important role for this.

Figure 1 illustrates a side view of an exemplary optical smoke detector boundary surface in accordance with some embodiments of the present disclosure provided herein. The smoke detector cap 100 includes a lower boundary 110, a circular sidewall 130, an upper boundary 120, an axial center 160, and geometric surfaces 140, 150.

Notably, fig. 1 depicts a side view of the smoke detector cap 100, which is circular, while looking from top to bottom. Thus, strictly speaking, the geometric surfaces 140, 150 are identical surfaces. However, for the purpose of clarifying photons 165, 175, they are labeled differently. This will be discussed in more detail later in this disclosure.

In one or more embodiments, the smoke detector cap 100 is used to reflect and/or absorb light such that light in the smoke detector chamber is largely scattered from particles (e.g., smoke, etc.) and returned to the smoke detector system. This is also discussed in more detail later in this disclosure. The lower boundary 110 may represent a Printed Circuit Board (PCB) or wafer die. For discussion purposes, light from one or more light emitting devices is emitted from the surface direction.

The circular sidewall 130 includes a substantially cylindrical boundary that keeps ambient light from being eliminated or prevents light present in the chamber from being redirected back to the lower boundary 110. Also, this premise will be described later. The upper boundary 120 represents the top of the smoke detector cap 100. Whereas the smoke detector cap is substantially unchanged in the radial direction, the axial center 160 is used to denote its center.

In operation, in some embodiments, light (photons 165, 175) is emitted from the light emitting device, propagating upward through the smoke detector chamber. . The light is incident on the smoke particles (not shown) and is therefore scattered. The scattered light propagates downward toward the lower boundary surface toward the one or more photodetectors. . In addition to scattered light, the photodetector also receives nominal light from the background.

In one or more embodiments, the geometric surfaces 150, 140 are used to reflect light emitted from the lower boundary 110 away from the lower boundary 110. That is, light that is not scattered by particulate matter should be mitigated in order to maximize the signal-to-noise ratio (SnR). For example, in the present embodiment, the geometric surfaces 150, 140 have a parabolic (strictly speaking, 3-d paraboloid) shape. Thus, depending on the parabolic focus, light emitted from the lower boundary 110 will be reflected substantially in a substantially orthogonal direction.

For example, ray/photon 165 is incident on geometry 150. Because of its direction and angle of incidence on geometry 150, ray photon 165 is reflected off lower boundary 110 represented by ray/photon 170. Similarly, ray/photon 175 is incident on geometry 140. Because of its direction and the angle of incidence on the geometry 140, ray photon 175 is reflected off of the lower boundary 110 represented by ray/photon 180.

The predetermined threshold, background subtraction, and other operating parameters will be discussed in more detail later in this disclosure, and those skilled in the art will understand these parameters.

Fig. 2 depicts a top view of an exemplary optical smoke detector 200 showing operation, in accordance with one or more embodiments of the present disclosure provided herein. The optical smoke detector 200 includes a Light Emitting Diode (LED)230, an optical chamber 210, a detector cover 220, a housing molding 280, a photodiode/transducer 250, and an optical deflection fin 290.

In one or more embodiments, LED 260 is an off-the-shelf green (495nm-570nm) light emitting diode. However, any suitable compact light generating device-whether a gas-connected, incandescent, or hot black body radiation, etc. -is not beyond the scope of this disclosure.

In some embodiments, the housing molding 290 is a substrate that provides a structure for attaching the detector cover 220 and the optical chamber 210 thereto. Generally, the purpose of an optical smoke detector is to allow smoke from the surrounding air/environment to enter, while rejecting ambient light emitted therefrom. Generally, the detector cover 220 and the optical chamber 210 are intended for these purposes.

That is, the detector cover 220 has two ports (e.g., inlet and outlet) for gas/smoke passage, while the optical chamber 210 substantially surrounds the detector interior, preventing most ambient light from entering. According to some embodiments of the present disclosure, the detector cover 220 and the optical chamber 210 are made of an opaque polymer and/or lossy material, the thickness of which is much greater than the average skin depth. High conductivity (mirror) or any other suitable material, such as metal, semi-metal, composite, without departing from the scope of the present disclosure.

Photodetector 250 is a sensor of light or other electromagnetic energy. Photodetector 250 has a p-n junction that converts photons to current. The absorbed photons form electron-hole pairs in the depletion region for detecting the received light intensity. In some embodiments, the photodetector 250 is a photodiode or a phototransistor. However, any light detection means, such as a avalanche, photomultiplier tube, etc., is not beyond the scope of the present disclosure.

In operation, light 240 is emitted from the LED 260. As will be appreciated by those skilled in the art, some of the light 240 is scattered out of the smoke particles 270. The scattered light 260 may be re-scattered or directed by the photodetector 250 and thus detected by the photodetector 250. The light 240 that is not scattered by the smoke particles 270 is blocked by the blocking member to prevent direct irradiation of the photodetector 250 or is incident and redirected by the optical defect fin 290. The optical deflector fins 290 typically have a black, matte finish, the purpose of which is to redirect light into the other optical deflector fins 290.

Fig. 3 depicts a top view of elements forming an exemplary optical smoke detection device 300 according to some embodiments of the present disclosure provided herein. In one or more embodiments, the substrate 310 includes an Analog Front End (AFE), a photodetector, and a light source, which will be discussed in more detail later in this disclosure.

In some embodiments, the optical isolation structure chamber post 320 is made of a material that absorbs light in its volume. In addition, the elements are smooth, having a mirror-like finish, rather than a matte finish. The bulk absorbing material is such that light wavelengths with a depth >10 are absorbed. Thus, the real part of the refractive index remains very close to that of the non-absorbing material.

In some embodiments, the optical isolation structure chamber column 320 comprises a polymer or glass. Most plastics and glass have indices approaching 1.45-1.6. This can yield a reflectance of R-3% from the fresnel equation, with the smooth surface reflecting the light specularly as follows:

wherein

And

therefore, most of the light incident is absorbed by the material of the cavity column of the light separation structure, and even the reflected portion is rarely backscattered.

Fig. 4A illustrates a shortcoming of the prior art with respect to an optical smoke detection device 400 in operation according to some embodiments of the present disclosure provided herein. In view of the fact that smoke detectors are expected to last 10 years or more, it is an object of the present disclosure to provide a robust, durable optical smoke detector.

The debilitating nature of dusk accumulation will be understood by those of ordinary skill in view of the constant air flux throughout the smoke detector, and will now be discussed in detail with reference to fig. 4A and 4B. Dust particles 420 adsorb to the optical isolation structure cell post 410. The incident light ray 430 may come from ambient light, background light, or from an internal light source of the smoke detector. For purposes of illustration, this description represents a simplification for clarity. That is, we assume that the light ray 430 is fully transmitted into the dust particle 420.

The incident light ray 430 is transmitted into the dust particle 420 as light ray 440. When a light ray 440 is incident on the optical isolation structure cell post 410, its energy (or vector magnitude) is resolved according to the Fresnel equations for transmission and reflection. This is due to the impedance mismatch between the dust and the optical isolation structure chamber column 410. Thus, light ray 450 is reflected and light ray 460 is transmitted into the optical isolation structure chamber column 410. In addition, the inventors of the present disclosure point out that if a rough surface (e.g., matte) is used on the optical isolation structure chamber column 410, the light will also scatter, which is also shown in FIG. 4A.

Fig. 4B illustrates the above-described shortcomings of the prior art with respect to the optical smoke detection device in operation and the elements comprised by the exemplary optical smoke detector 400 according to some embodiments of the present disclosure provided herein. Dust particles 420 adsorb to the optical isolation structure chamber column 410. The incident light ray 430 may come from ambient light, background light, or from an internal light source of the smoke detector. Also, for purposes of illustration, this description represents a simplification for clarity. That is, we assume that the light ray 430 is fully transmitted into the dust particle 420.

The incident light ray 430 is transmitted into the dust particle 420 as light ray 440. When a light ray 440 is incident on the optical isolation structure cell post 410, its energy (or vector magnitude) is typically resolved according to Fresnel's equations for transmission and reflection. However, in one or more embodiments of the present disclosure, the real part of the complex impedance (or index of refraction) of the optical isolation structure chamber column 410 is matched to ordinary dust 420. Thus, the light ray 440 is transmitted almost entirely into the optical isolation structure chamber column 410. Most dust particles have refractive indices between 1.35 and 1.55, while most plastics and glass have refractive indices between 1.45 and 1.55.

In one or more embodiments, the imaginary part of the complex impedance of the optical isolation structure cavity column 410 is selected such that the material is very lossy, such that the penetration depth is on the order of tens of wavelengths. If the penetration depth is short, the impedance mismatch becomes large and the substrate begins to reflect the radiation again 440. If the absorption depth is too large, thick members are required to absorb light and thus increase the overall size of the chamber. This is illustrated in attenuated light wave 470 in fig. 4B. Additionally, in a preferred embodiment, the inventors of the present disclosure present a smooth mirror finish on the surface of the optical isolation structure chamber post 410.

Fig. 5 depicts a top perspective view of an optical inspection tool comprised by an exemplary optical smoke inspection apparatus 500 in accordance with some embodiments of the present disclosure provided herein. Optical smoke detection device 500 includes a substrate 590, Light Emitting Diodes (LEDs) 560, 565, LED cover 520, Analog Front End (AFE) 540, photodetector (PD1)550, photodetector (PD2)530, photodetector cover 570, PD pin 575, and AFE pin 585.

Substrate 590 is a mold fabricated by a silicon on chip (SoC) fabrication process, which is known in the art, however any suitable support structure is not beyond the scope of the present disclosure. For example, the substrate 590 may be made of any metal, semi-metal, semiconductor, mixture/compound, or polymer, provided care is taken to ensure that the AFE 540 does not short.

The light blocking member extends along the periphery of the upper substrate 590. Their function is to block ambient light from being received by the photodetectors 530, 550. Thus, according to some embodiments of the present disclosure, the ambient light blocking member is made of an opaque polymer and/or lossy material, the thickness of which is much greater than the average skin depth. High conductivity (mirror image) is not beyond the scope of this disclosure.

Similarly, the opto-isolators traverse the entire span between the sides of the LEDs 560, 565 and the sides of the photodetectors 530, 550 of the device, as will be explained in more detail later in this disclosure. The function of the opto-isolator is to prevent light from LEDs 560, 565 from being received directly by photodetectors 530, 550. Thus, according to some embodiments of the present disclosure, the optical isolator is made of an opaque polymer and/or lossy material, the thickness of which is much greater than the average skin depth. High conductivity (mirror) is also not beyond the scope of the present disclosure, however, this is not a preferred embodiment, as will be clear later in the disclosure.

Photodetector cover 570 and LED cover 520 are transparent polymeric protective shells for photodetectors 530, 550 and LEDs 560, 565, respectively. In other embodiments, the photodetector cover 570 and the LED cover are crystalline (glass, pyrex, etc.), but any suitable may be used.

In one or more embodiments, the LEDs 560, 565 are off-the-shelf red and near infrared (450nm-1400nm) light emitting diodes. However, any suitable compact light generating device of any color is not beyond the scope of the present disclosure. In some embodiments where LEDs 560, 565 emit different wavelengths, photodetector (PD1)550 and photodetector (PD2)530 may be modified to accommodate their detection. For example, photodetector (PD1)550 and half of photodetector (PD2)530 may be covered with different filters.

In particular, photodetector (PD1)550 and photodetector (PD2)530 may be at least partially covered with dichroic filters. A dichroic filter, thin film filter or interference filter is a very precise filter for selectively transmitting a small range of colors of light while reflecting other colors. In contrast, dichroic mirrors and dichroic mirrors tend to be characterized by the color of the light they reflect, rather than the color they pass through.

Although dichroic filters are used in the present embodiment, other filters, such as interference, absorption, diffraction, gratings, fabry-perot, etc., are not beyond the scope of the present disclosure. The interference filter consists of a plurality of thin dielectric layers (materials with different refractive indices). A metal layer may also be present. In its broadest sense, an interference filter also includes an etalon, which may be implemented as a tunable interference filter. The interference filter has wavelength selectivity due to an interference effect occurring between an incident wave and a reflected wave at a boundary of the thin film.

In other embodiments, multiple detectors are implemented, e.g., at least two for wavelength, such that each of the multiple detectors is wavelength specific. For example, for a particular λ, there are at least two detectors (PD1, PD2) per led.

The analog front end 540(AFE) is a set of analog signal conditioning circuits that use sensitive analog amplifiers, operational amplifiers, filters, and application specific integrated circuits, connected as needed with sensors to analog-to-digital converters and/or microcontrollers.

AFE 540 is in electrical communication with photodetectors 530, 550 through PD pin 575. PD pin 575 is in electrical communication with photodetectors 530, 550 through traces. In the present embodiment, photodetectors 530, 550 and AFE 540 are packaged as dies with solder pins. However, in other embodiments, they are integrated at the wafer level, communicating through traces and Vertical Interconnect Access (VIA) or through silicon VIA (tsv).

In some embodiments, AFE pin out 585 is in electrical communication with pulse oximeter 100. In other embodiments, AFE pin out 585 may be in electrical communication with a microcontroller unit (MCU), Field Programmable Gate Array (FPGA), bus, or other computer platform, such as Arduino or Raspberry Pi, all without departing from the scope of the disclosure.

Fig. 6 depicts a side view of an optical detection die 600 comprised by an example optical smoke detection apparatus in accordance with some embodiments of the present disclosure provided herein. The optical inspection mold 600 includes an ambient light blocking member 610, an optical isolator 680, a substrate 690, a Light Emitting Diode (LED)660, an LED cover 620, an Analog Front End (AFE)640, a photodetector (PD1)650, a photodetector (PD2) 630, and a photodetector cover 670.

In one or more embodiments, substrate 690 is a die fabricated by a silicon on chip (SoC) fabrication process known in the art, however any suitable support structure is not beyond the scope of the present disclosure. For example, the substrate 690 may be made of any metal, semi-metal, semiconductor, mixture/compound, or polymer, as long as care is taken to ensure that the AFE 640 does not short.

The ambient light blocking member 610 extends along the periphery of the upper substrate 690. Their function is to block ambient light from being received by the photodetectors 630, 650. Thus, according to some embodiments of the present disclosure, the ambient light blocking member 610 is made of an opaque polymer and/or lossy material, the thickness of which is much greater than the average skin depth. High conductivity (mirror image) is not beyond the scope of this disclosure.

Similarly, optical isolator 680 traverses the entire span between the side of LED 660 and the side of the device's photodetectors 630, 650, as will be explained in more detail later in this disclosure. The function of optical isolator 680 is to prevent light from LED 660 from being received directly by photodetectors 630, 650. Thus, in accordance with some embodiments of the present disclosure, optical isolator 680 is made of an opaque polymer and/or lossy material, the thickness of which is much greater than the average skin depth. High conductivity (mirror) is also not beyond the scope of the present disclosure, however, this is not a preferred embodiment, as will be clear later in the disclosure.

In one or more embodiments, LED 660 is an off-the-shelf green (495nm-570nm) light emitting diode. However, any suitable compact light generating device-whether a gas-connected, incandescent, or hot black body radiation, etc. -is not beyond the scope of this disclosure. The LED cover 630 is a transparent polymer protective shell of the LEDs 260. In other embodiments, the LED cover 630 is crystalline (glass, pyrex, etc.), although any suitable may be used. While translucent and/or lossy materials can be used within the scope of the present disclosure, these are not preferred embodiments, as will become more apparent later in the disclosure.

Photodetectors 650, 630 (PD1, PD2, respectively) are sensors of light or other electromagnetic energy. The photodetectors 630, 650 have p-n junctions that convert photons into current. The absorbed photons form electron-hole pairs in the depletion region for detecting the received light intensity. In some embodiments, the photodetectors 650, 630 are photodiodes or phototransistors. However, any light detection means, such as a avalanche, photomultiplier tube, etc., is not beyond the scope of the present disclosure.

The analog front end 640(AFE or analog front end controller AFEC) is a set of analog signal conditioning circuits that use sensitive analog amplifiers, typically operational amplifiers, filters, and sometimes application specific integrated circuits for sensors, radio receivers and other applications to provide configurable and flexible electronic block circuitry requiring the connection of various sensors to an antenna, analog-to-digital converter or in some cases to a microcontroller. The AFE 640 is in electrical communication with the photodetectors 650, 630 and the optical smoke detector.

The photodetector cover 670 is a transparent polymer protective shell of PD1 and PD 2. In other embodiments, the photodetector cover 670 is crystalline (glass, Pyrex, etc.), but any suitable may be used. Although translucent and/or lossy materials may be used within the scope of the present disclosure.

Figure 7 graphically illustrates an isometric view of an example optical smoke detection device 700 in operation according to some embodiments of the present disclosure provided herein. The inventors of the present disclosure have constructed a minimal smoke detector 700 that requires only a very small chamber around the detector to protect it from insects, ambient light and large particulate matter.

Heretofore, in the prior art, a large-sized housing is used to prevent light scattering of dust accumulation with the passage of time. Light scattered from the housing element may prevent small variations in the light scattering that detect smoke particles, thereby hindering the performance of these sensor systems. Therefore, housing or room design plays a crucial role. It must also allow easy exchange of fumes from the surrounding environment, and therefore have a considerable opening.

The present disclosure shows how to build a very compact housing around a smoke detector while keeping the reflection from the housing structure to very low values while meeting all other peripheral requirements of fast response to smoke and protection from ambient light. This allows light scattering measurements of very small smoke particles to be reliable.

The optical smoke detection device 700 includes a base 750, a die substrate 710, side casings 730, an optical isolation structure chamber post 720, and an upper reflective surface 740. In one or more embodiments, the submount 750 may be comprised of a PCB or a way of carrying all the electronics and providing a connection means, the optical isolation structure chamber post 720 and the die substrate 710 are consistent with those described with respect to fig. 2, 3, 5 and 6. Side casing 730 may serve two purposes. That is, side casing 730 blocks the entry of the environment while directing air through the optical smoke detection device 700 channels.

The structure of the upper reflecting surface 740 is similar to the side structure and uses the same design concept. Light incident from a light emitter directly impinging on the surface should be minimally reflected/scattered back from the surface of the structure. This is achieved by using a highly corrugated or curved surface so that no direct reflection from the surface is directed towards the photodetector element. The light is reflected to other surfaces in the chamber. As previously described with respect to fig. 4B, light incident on the surface is primarily absorbed in most materials. A small amount of about 3% of the reflected light is directed to the upper reflection or another surface on any side surface, where the process repeats. Thus, a very small amount of light returns to the photodetector.

It should be noted that the upper reflective surface may be an anti-reflective coating to absorb better in the volume, but may not be necessary in practice. This is because light can be incident on the surface from many angles, especially if the top reflective surface is corrugated or curved in a complex manner. Furthermore, the surface may not be as anti-reflective after collecting dust on the surface.

In operation, light from cone 760 is directed in an upward manner. The light returning to the detector has bounced off various components multiple times and has lost most of the energy. Ray tracing shows that the probability of a ray returning to the detector is very low.

The optical isolation structure chamber posts 720, 740 comprise plastic absorber rods. For example, the optical isolation structure chamber column 720 comprises acrylic, PMMA, polycarbonate, or the like. However, any suitable material may be used, for example having a suitably matched refractive index and complex impedance.

The design shown in figure 7 allows one to measure the light scattered back from smoke particles to the photodetector while the optical structure is designed to reduce the noise light to a very low level. Furthermore, these optical structures can be placed very close to each other and on the light generating and detecting device, resulting in a very compact structure. This configuration reduces (1) noise light from the light emitter, (2) noise light from the environment, and (3) provides compact measurements with a single module, such as those shown in fig. 5 and 6.

Fig. 8 depicts a top view of another design of elements forming an exemplary optical smoke detection device 800 in accordance with some embodiments of the present disclosure provided herein. In one or more embodiments, the substrate 810 includes an Analog Front End (AFE), a photodetector, and a light source according to the previous embodiments. In addition, a similar upper reflective structure, e.g., 740, may be used.

According to some embodiments, the optical smoke detection device 800 comprises an inlet port 850, an outlet port 860 and an ionized smoke detector 840. The ports 850, 860 allow an air path to travel through the optical smoke detection apparatus 800. In an alternative embodiment, inlet port 850 and outlet port 860 include small, low-power fans to facilitate such passage of gas.

The ionized smoke detector 840 ionizes the air using a radioisotope, usually americ-241, detecting the difference caused by smoke and generating an alarm. Ionization detectors are more sensitive to the flame phase of a flame than optical detectors, which are more sensitive to fire during the early smoldering phase.

The smoke detector has two ionization chambers 840, 880, an air opening (840), and a reference chamber (880) that does not allow particles to enter. The radiation source emits alpha particles into both chambers, ionizing some of the air molecules. There is a potential difference (voltage) between the pair of electrodes in the chamber and the charge on the ions allows current to flow.

The currents in the two chambers should be the same as they are equally affected by gas pressure, temperature and source aging. If any smoke particles enter the open chamber, some ions will attach to the particles and cannot be used to carry the current in the chamber. The electronic circuit detects that a current differential has been established between the open chamber and the sealed chamber and sounds an alarm.

In some embodiments, optical isolation structure chamber deflector 820 is made of a material that absorbs light in its volume. In addition, the elements are smooth, having a mirror-like finish, rather than a matte finish. The bulk absorbing material is such that light wavelengths with a depth >10 are absorbed. Thus, the real part of the refractive index remains very close to that of the non-absorbing material.

In some embodiments, the optical isolation structure chamber deflector 820 comprises substantially a three-dimensional home position, a right rectangular prism, a rectangular cube, or a cuboid. In one or more embodiments, the optical isolation structure chamber deflector 820 is substantially circular on one surface or may have a knife edge. Note that this also applies to the upper reflecting surface 740. The purpose of the optical isolation structure chamber deflector 820 is to direct the reflected light into another optical isolation structure chamber deflector 820, as will be understood by those of ordinary skill in the art. Thus, most of the incident light is absorbed by the material and even the reflected portion is less reflected.

Most dust particles have a glass index between 1.4 and 1.7. Optically isolated structure chamber deflector 820 is index matched and produces lower scattering than the same particles attached to surfaces of very different indices of refraction. All forward scatter from these particles is also absorbed by their substrate. Again, this results in very low backscattering of dust accumulation over time.

The components of the chamber, i.e., the optical isolation structure chamber deflector 820, are aligned to reflect light away from the source and toward other components of the chamber. Thus, the light is extinguished extremely quickly. After n reflections, the reflected light is reduced to Rn and quickly removed. This makes the design very compact: the radius from the centre of the smoke sensor is less than 1 cm and the height is <1 cm.

Figure 9A illustrates a side view of an exemplary compact smoke detector cap according to some embodiments of the present disclosure provided herein. The smoke detector cap 900 includes an upper boundary 910 and an optical deflection fin 920.

Fig. 9B depicts a top view of an exemplary compact smoke detector cap according to some embodiments of the present disclosure provided herein. The smoke detector cap 900 includes a geometric space 940 and an optical deflector fin 920. In one or more embodiments, the geometric shape 940 may be any parabolic or elliptical shape. In other embodiments, it may be diverse or even linear.

Figure 9C illustrates an isometric view of an exemplary compact smoke detector cap according to some embodiments of the present disclosure provided herein. The smoke detector cap 900 includes a geometry 940 and optical deflector fins 920.

In some embodiments, optical isolation structure cavity optical deflector fin 920 is made of a material that absorbs light within its body. In addition, the elements are smooth, having a mirror-like finish, rather than a matte finish. The bulk absorbing material is such that light wavelengths with a depth >10 are absorbed. Thus, the real part of the refractive index remains very close to that of the non-absorbing material.

In some embodiments, optical isolation structure cavity optical deflector fin 920 comprises a polymer or glass. Most plastics and glass have indices approaching 1.45-1.6. This can yield a reflectance of R-3% from the fresnel equation, with the smooth surface reflecting the light specularly as follows:

wherein

And

thus, most of the light incident is absorbed inside the material of the cavity post of the optical isolation structure and even the reflected portion is rarely backscattered.

Figure 10A illustrates a side view of an exemplary compact smoke detector cap according to some embodiments of the present disclosure provided herein. The smoke detector cap 1000 includes an upper boundary 1010, an axial center 1060, a center wrapping pin 1040, and an overwrap pin 1070. The axially central wrapping pin 1040 and the overwrap pin 1070 allow for ease.

Fig. 10B depicts a top view of an exemplary compact smoke detector cap according to some embodiments of the present disclosure provided herein. The smoke detector cap 1000 includes a geometric space 1040 and an optical deflector fin 1020. In one or more embodiments, the geometric shape 1040 can be any parabolic or elliptical shape. In other embodiments, it may be diverse or even linear. The outer boundary 1030 represents a physical circular cap of the structure.

Figure 10C illustrates an isometric view of an exemplary compact smoke detector cap according to some embodiments of the present disclosure provided herein. The smoke detector cap 1000 includes a physical circular cap 1010 of structure 1080 and optical deflector fins 1020.

Figure 11 illustrates a side view of an exemplary optical smoke detector boundary surface in accordance with some embodiments of the present disclosure provided herein. The smoke detector cap 1100 includes a lower boundary 1110, a circular sidewall 1130, an upper boundary 120, an axial center 1160, and geometric surfaces 1140, 1150.

Notably, fig. 11 depicts a side view of the smoke detector cap 1100, which is circular, while looking from top to bottom. Thus, strictly speaking, the geometric surfaces 1140, 1150 are the same surfaces. However, for the purpose of clarifying photons 1165, 1175, they are labeled differently.

In one or more embodiments, the smoke detector cap 1100 is used to reflect and/or absorb light such that light in the smoke detector chamber is largely scattered from particles (e.g., smoke, etc.) and returned to the smoke detector system. Lower boundary 1110 may represent a Printed Circuit Board (PCB) or wafer die. For discussion purposes, light from one or more light emitting devices is emitted from the surface direction.

The circular sidewall 1130 includes a substantially cylindrical boundary that keeps ambient light from being eliminated or prevents light present in the chamber from being redirected back to the lower boundary 1110. Again, this premise will be described later. The upper boundary 1120 represents the top of the smoke detector cap 1100. Whereas the smoke detector cap is substantially invariant in the radial direction, the axial center 1160 is used to denote the center thereof.

Operationally, in some embodiments, light rays (photons 1165, 1175) are emitted from the light emitting device that propagate upward through the smoke detector chamber. The light is incident on smoke particles (not shown) and is therefore scattered. The scattered light propagates downward toward the lower boundary surface toward the one or more photodetectors. In addition to scattered light, the photodetector also receives nominal light from the background.

In one or more embodiments, the geometric surfaces 1150, 1140 serve to reflect light emitted from the lower boundary 1110 away from the lower boundary 1110. That is, light that is not scattered by particulate matter should be mitigated in order to maximize the signal-to-noise ratio (SnR). For example, in the present embodiment, the geometric surfaces 1150, 1140 have a parabolic (strictly speaking, 3-d paraboloid) shape. Thus, depending on the parabolic focus, light emitted from the lower boundary 110 will be reflected substantially in a substantially orthogonal direction.

For example, ray/photon 1165 is incident on geometry 1150. Due to its direction and angle of incidence on the geometry 1150, light photon 165 is reflected off of lower boundary 1110 as represented by light ray/photon 1170. Similarly, ray/photon 1175 is incident on geometry 1140. Due to its direction and angle of incidence on the geometry 1140, ray photon 1165 is reflected off of lower boundary 1110 represented by ray/photon 117.

In one or more embodiments, an additional anti-reflective coating 1180 is included. An anti-reflective or anti-reflective (AR) coating is an optical coating applied to the surface of lenses and other optical elements to reduce reflections. In typical imaging systems, this improves efficiency because less light is lost due to reflection. The coating is not specific to the top cover but may be applied to the anti-reflective fins as previously described.

Many coatings consist of a transparent thin film structure with alternating layers of contrasting refractive indices. The layer thicknesses are selected to produce destructive interference in the light beams reflected from the interface and constructive interference in the corresponding transmitted light beams. This causes the properties of the structure to vary with wavelength and angle of incidence, so that the color effect usually appears at an oblique angle.

In another embodiment, the geometry is a parabolic geometry. The parabola is a planar curve which is mirror symmetric and approximately U-shaped. It applies to any of several seemingly different mathematical descriptions, which can prove to define exactly the same curve. More specifically, as in the present embodiment depicted in fig. 11, the semiparabolic line is an implement. That is, sqrt (r) rotates about the axis center 1160.

One description of a parabola relates to a point (focus) and a line (directrix). The focal point is not on the directrix. The parabola is the locus of points in the plane equidistant from the directrix and the focal point. Another description of parabolas is the conic section, which results from the intersection of a circular conic surface and a plane parallel to another plane tangent to the conic surface.

In other embodiments, the geometric shape is at least partially elliptical. An ellipse is a curve in a plane around two foci such that the sum of the distances to the two foci is constant for each point on the curve. It is therefore a generalization of a circle, which is a special type of ellipse with two foci at the same location. The shape of the ellipse (how "elongated" it is) is represented by its eccentricity, which for an ellipse can be from 0 (limit case of a circle) to any number close to but less than 1.

An ellipse is a closed type conic: the plane curve resulting from the intersection of the cone and the plane (see right). Ellipses have many similarities to the other two forms of conic section: parabolic and hyperbolic curves, both open and unbounded. The cross-section of the cylinder is elliptical unless the section is parallel to the axis of the cylinder.

However, any conical portion is not beyond the scope of the present disclosure.

The present disclosure produces a total attenuation from the LED to the detector of the order of 10^-6. This is achieved by simulation and construction design.

The inventors of the present disclosure also utilize these concepts and these scattering properties may be wavelength dependent. Thus, analysis and/or comparison of different wavelengths, λ, and/or ratios of PD1/PD2 may be wavelength dependent and may be useful for detecting a large number of particulate matter.

Other devices, systems, and apparatuses are not beyond the scope of this disclosure. For example, a plurality of 3 or more photodetectors may be used to further interpolate and extrapolate the characteristic signals of the material. In addition, alternative LED/photodetector configurations and geometries may be used.

With respect to the theory of scattering of light, the inventors' observations and models closely conform to, and reflect, such well-known theory known to those skilled in the art. The observations that follow are therefore derived from potential physical factors and are therefore more general than any particular device enumerated in the several embodiments.

Having thus described several aspects and embodiments of the technology of the present application, it is to be appreciated various alterations, modifications, and improvements will readily occur to those skilled in the art. Such alterations, modifications, and improvements are intended to be within the spirit and scope of the technology described in this application. For example, various other means and/or structures for performing the function and/or obtaining the result and/or one or more of the advantages described herein will be readily apparent to those of ordinary skill in the art, and each of these variations and/or modifications is considered to be within the scope of the embodiments described herein.

Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments described herein. It is, therefore, to be understood that the foregoing embodiments are presented by way of example only and that, within the scope of the appended claims and equivalents thereto, embodiments of the disclosure may be practiced otherwise than as specifically described. In addition, two or more features, systems, articles, materials, kits, and/or methods described herein are included within the scope of the present disclosure if such features, systems, articles, materials, kits, and/or methods are not mutually inconsistent.

The above-described embodiments may be implemented in any of a variety of ways. One or more aspects and embodiments of the present application relating to the performance of a process or method may be implemented using program instructions executable by a device (e.g., a computer, processor, or other device) to perform or control the performance of a process or method.

In this regard, the various disclosed concepts may be embodied as a computer readable storage medium (or multiple computer readable storage media) (e.g., a computer memory, one or more floppy discs, optical discs, magnetic tapes, flash memories, circuit configurations in field programmable gate arrays or other semiconductor devices, or other tangible computer storage medium) encoded with one or more programs that, when executed on one or more computers or other processors, perform methods that implement one or more of the various embodiments described above.

The computer-readable medium or media may be transportable, such that the program stored thereon can be loaded onto one or more different computers or other processors to implement the various aspects described above. In some embodiments, the computer readable medium may be a non-transitory medium.

The terms "program" or "software" are used herein in a generic sense to refer to any type of computer code or set of computer-executable instructions that can be employed to program a computer or other processor to implement various aspects as described above. In addition, it should be appreciated that according to one aspect, one or more computer programs that when executed perform methods of the present application need not reside on a single computer or processor, but may be distributed in a modular fashion amongst a number of different computers or processors to implement various aspects of the present application.

Computer-executable instructions may be in many forms, such as program modules, executed by one or more computers or other devices. Generally, program modules include routines, programs, objects, components, data structures, etc. that perform particular tasks or implement particular abstract data types. Typically, the functionality of the program modules may be combined or distributed as desired in various embodiments.

Furthermore, the data structures may be stored in any suitable form on a computer readable medium. To simplify the illustration, the data structure may be shown with fields that are related by location in the data structure. Such relationships may also be implemented by allocating memory for fields having locations that convey relationships between fields in a computer-readable medium. However, any suitable mechanism may be used to establish relationships between information in fields of a data structure, including through the use of pointers, tags, or other mechanisms that establish relationships between data elements.

When implemented in software, the software code can be executed on any suitable processor or collection of processors, whether provided in a single computer or distributed among multiple computers.

Further, it should be understood that a computer may be embodied in any of a number of forms, such as a rack-mounted computer, a desktop computer, a laptop computer, or a tablet computer, as non-limiting examples. Additionally, a computer may be embedded in a device not normally considered a computer but with suitable processing capabilities, including a Personal Digital Assistant (PDA), a smart phone, a mobile phone, an iPad, or any other suitable portable or fixed electronic device.

In addition, a computer may have one or more input and output devices. These devices may be used to present, among other things, a user interface. Examples of output devices that may be used to provide a user interface include printers or display screens for visual presentation of output and speakers or other sound generating devices, for audible presentation of output. Examples of input devices that may be used for the user interface include keyboards, and pointing devices, such as mice, touch pads, and digitizing tablets. As another example, a computer may receive input information through speech recognition or other audible format.

The computers may be interconnected IN any suitable form by one or more networks, including a local area network or a wide area network, such as an enterprise network, and an Intelligent Network (IN) or the Internet. Such networks may be based on any suitable technology and may operate according to any suitable protocol and may include wireless networks or wired networks.

Also, as described, some aspects may be embodied as one or more methods. The actions performed as part of the method may be ordered in any suitable way. Accordingly, embodiments may be constructed in which acts are performed in an order different than illustrated, which may include performing some acts concurrently, even though shown as sequential acts in exemplary embodiments.

All definitions, as defined and used herein, should be understood to control dictionary definitions, definitions in documents incorporated by reference, and/or ordinary meanings of the defined terms.

The indefinite articles "a" and "an" as used in this specification and claims should be understood to mean "at least one" unless explicitly indicated to the contrary.

The phrase "and/or" as used in this specification and claims should be understood to mean "one or two" of the elements so combined, i.e., elements that are present in combination in some cases and are present in isolation in other cases. Multiple elements listed with "and/or" should be construed in the same manner, i.e., "one or more" of the elements so combined.

Elements other than those specifically identified with the "and/or" clause may optionally be present, whether related or unrelated to those specifically identified. Thus, as a non-limiting example, when used in conjunction with open language such as "including," references to "a and/or B" may refer in one embodiment to only a (optionally including elements other than B); in another embodiment, limited to only B (optionally including elements other than a); in yet another embodiment, refers to both a and B (optionally including other elements); and so on.

As used in this specification and the claims, the phrase "at least one," in reference to a list of one or more elements, should be understood to mean at least one element selected from any one or more of the elements in the list of elements, but not necessarily including at least one of each element specifically listed in the list of elements, and not excluding any combinations of elements in the list of elements. This definition also allows that elements may optionally be present in addition to those specifically identified in the list of elements to which the phrase "at least one" refers, whether related or unrelated to those elements specifically identified.

Thus, as a non-limiting example, "at least one of a and B" (or, equivalently, "at least one of a or B," or, equivalently, "at least one of a and/or B") can refer in one embodiment to at least one a, optionally including more than one, absent B (and optionally including elements other than B); in another embodiment, to at least one B, optionally including more than one, absent a (and optionally including elements other than a); in yet another embodiment, to at least one a, optionally including more than one, and at least one B, optionally including more than one (and optionally including other elements); and so on.

As used herein, the term "between" is inclusive, unless otherwise specified. For example, unless otherwise specified, "between a and B" includes a and B.

Also, the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of "including," "comprising," or "having," "containing," "involving," and variations thereof herein, is meant to encompass the items listed thereafter and equivalents thereof as well as additional items.

In the claims, as well as in the specification above, all transitional phrases such as "comprising," "including," "carrying," "having," "containing," "involving," "holding," "consisting of," and the like are to be understood to be open-ended, i.e., to mean including but not limited to. The only transitional phrases "consisting of and" consisting essentially of shall be the closed or semi-closed transitional phrases, respectively.

Therefore, the present disclosure should not be considered limited to the particular examples described above. Various modifications, equivalent processes, as well as numerous structures to which the present disclosure may be applicable will be readily apparent to those of skill in the art to which the present disclosure is directed.

According to one aspect, the present disclosure is an apparatus for identifying smoke using the optical analysis techniques described herein. In particular, the device is arranged in an optical smoke detector and performs recognition therein.

According to another aspect of the device, the light is transmitted through the air and the light is scattered by the smoke particles.

According to another aspect, the scattered light is incident on one or more detectors, each disposed at various distances from the light source, transmitted from the light.

According to another aspect, the ratio of detected light is used to determine the presence of smoke.

According to yet another aspect, an apparatus utilizes logic that, when executed, performs the steps of receiving light information and making a smoke determination.

According to another aspect of the disclosure, the device further includes a cap disposed substantially orthogonal to the first light source.

According to another aspect of the disclosure, the cap is substantially shaped like a conical portion, at least partially shaped.

According to another aspect of the disclosure, the cap of the tapered portion is at least partially parabolic.

According to another aspect of the disclosure, the cap of the tapered portion is at least partially elliptical.

According to another aspect of the disclosure, the device further includes a first light emitting diode having a spectral intensity centered at the first wavelength λ 1.

According to another aspect of the disclosure, the device further comprises an array of optical deflecting elements arranged substantially in a circle around the outer radius of the cap.

According to another aspect of the disclosure, the apparatus further comprises an anti-reflective coating disposed on at least one of the cap and the array of optical deflecting elements.

According to another aspect of the present disclosure, the coating is centered at the first wavelength λ 1.

According to another aspect of the disclosure, the device further includes a base plate, the cover being mechanically coupled to the base plate.

According to another aspect of the disclosure, the array of optical deflection elements is substantially wing-shaped.

According to another aspect, the present disclosure includes an analog front end in electrical communication with one or more photodetectors.

According to yet another aspect of the present disclosure, a plurality of light sources are used, each light source having a wavelength centered at a different frequency.

According to yet another aspect of the present disclosure, each wavelength facilitates determining the presence of smoke.

According to yet another aspect of the present disclosure, a plurality of lossy members surround the center of the detector chamber.

According to yet another aspect of the disclosure, the plurality of lossy members are substantially configured as columns.

According to yet another aspect of the present disclosure, the plurality of lossy members are substantially configured like wing-like features of a heat sink.

According to yet another aspect of the present disclosure, the plurality of lossy members are substantially configured to have a refractive index close to that of household dust.

According to yet another aspect of the disclosure, the plurality of lossy members also has an imaginary part of a complex impedance of the lossy impedance. This may not only mitigate reflections from ambient light (impedance matching) but may also absorb the power fluorescent medium, which may give a positive effect of a false smoke detector.

According to another aspect of the present disclosure, a compact smoke detector may consist of a single Analog Front End (AFE).

According to another aspect of the disclosure, a compact smoke detector and a single Analog Front End (AFE) may be fabricated from multiple dies on a substrate.

In accordance with another aspect of the present disclosure, a compact smoke detector may use one or more optical filters.

According to yet another aspect of the present disclosure, a compact smoke detector may use one or more optical filters. In particular, the filter may comprise an absorption filter and/or an interference or dichroic filter.

Item 1. an apparatus for detecting smoke within a compact footprint detector that propagates light substantially away from a smoke detector chamber, the apparatus comprising:

a first light source;

a first photodetector disposed substantially adjacent to the first light source;

non-volatile logic for execution:

receiving a first signal from a first photodetector; and the combination of (a) and (b),

determining the presence of smoke based at least on the first received signal; and

the cover is disposed substantially orthogonal to the first light source.

Item 2. the device of item 1, wherein the lid is at least partially formed in a shape substantially similar to a conical cross-section.

Item 3. the device of item 2, wherein the cap of the tapered portion is at least partially parabolic.

Item 4. the device of item 2, wherein the cap of the tapered portion is at least partially elliptical.

Item 5. the device of item 1, further comprising a first light emitting diode having a spectral intensity centered at the first wavelength λ 1.

Item 6. the device of item 5, further comprising an array of optical deflecting elements disposed in a circle substantially around an outer radius of the cap.

Item 7. the device of item 6, wherein the array of optical deflection elements is substantially wing-shaped.

Item 8. the device of item 6, further comprising an anti-reflective coating disposed on at least one of the cap and the array of optical deflecting elements.

Item 9. the device of item 6, wherein the coating is centered about the first wavelength λ 1.

Item 10. the device of item 1, further comprising a base plate, the cover mechanically coupled to the base plate.

Item 11. a method for detecting smoke within a compact footprint detector that propagates light substantially away from a smoke detector chamber, the apparatus comprising:

providing light from a first light source;

detecting light on a first photodetector disposed proximate to the first light source;

receiving a first signal from a first photodetector;

determining a presence of smoke based at least in part on the first received signal based on the scattering particulate matter; and the combination of (a) and (b),

the light is reflected using a cap that geometrically reflects light away from the first photodetector.

Item 12. the method of item 11, wherein the cap is substantially shaped like a conical cross-section, at least partially shaped.

Item 13. the method of item 12, wherein the cap of conical cross-section is at least partially parabolic.

Item 14. the method of item 12, wherein the cap of the conical portion is at least partially elliptical.

Item 15 the method of item 11, wherein the first light source is a first light emitting diode having a spectral intensity centered at a first wavelength λ 1.

Item 16. the method of item 15, further comprising disposing the array of optical deflection elements in a substantially circular form about an outer radius of the cap.

Item 17 the method of item 16, wherein the array of optical deflection elements is substantially wing shaped.

Item 18. the method of item 16, further comprising depositing an anti-reflective coating on at least one of the cap and the array of optical deflection elements.

Item 19. the method of item 16, wherein the coating is centered about the first wavelength λ 1.

Item 20 the method of item 11, further comprising mechanically coupling the cap to a substrate.

Item 21. an apparatus for detecting smoke within a compact footprint detector that propagates light substantially away from a smoke detector chamber, the apparatus comprising:

means for providing light from a first light source;

means for detecting light on a first photodetector disposed proximate the first light source;

means for receiving a first signal from a first photodetector;

means for determining a presence of smoke based at least in part on the first received signal based on the scattering particulate matter; and the combination of (a) and (b),

means for reflecting light using a cap that geometrically reflects light away from the first photodetector. Light from the cap is used which geometrically reflects light away from the first photodetector.

According to one aspect of the present disclosure, a method for detecting smoke within a compact footprint detector that mitigates the deleterious effects of dust, thereby increasing lifetime and efficacy, the method comprising:

providing light from a first light source;

detecting light on a first photodetector disposed proximate to the first light source;

receiving a first signal from the first photodetector;

determining a presence of smoke based at least in part on the first received signal of scattering particulate matter; and

ambient light is absorbed using a plurality of lossy optical members having a refractive index between 1.4 and 1.7.

In one embodiment, wherein the first light source comprises a first light source having a first wavelength λ surrounding₁A first Light Emitting Diode (LED) of centered spectral intensity.

In one embodiment, the method further comprises providing light above.

In one embodiment, the second light source comprises a second light source having a wavelength around a second wavelength λ₂A second Light Emitting Diode (LED) of centered spectral intensity.

In one embodiment, the method further comprises receiving a second signal from a second photodetector having a wavelength around a second wavelength λ₂As the central spectral intensity.

In one embodiment, the method further comprises blocking direct illumination from the first light source by an opaque barrier between the light source and the first photodetector.

In one embodiment, the method further comprises providing a substrate.

In one embodiment, the method further comprises disposing an Analog Front End (AFE) on the substrate.

In one embodiment, the method further comprises disposing a first photodetector and a second photodetector on the analog front end.

In one embodiment, wherein the first light source is disposed on the substrate.

Claims (11)

1. An apparatus for detecting smoke within a compact footprint detector that propagates light away from a smoke detector chamber, comprising:

a first light source;

a first photodetector disposed proximate to the first light source;

non-volatile logic to perform:

receiving a first signal from a first photodetector; and the combination of (a) and (b),

determining the presence of smoke based at least on the received first signal; and

a cap disposed orthogonal to the first light source.

2. The apparatus for detecting smoke within a compact footprint detector of claim 1, in which the shape of the cap is at least partially a quasi-conical cross-section.

3. The apparatus for detecting smoke within a compact footprint detector of claim 2, in which the conical cross-section of the cap is at least partially parabolic.

4. The apparatus for detecting smoke within a compact footprint detector of claim 2, in which the conical cross-section of the cap is at least partially elliptical.

5. The apparatus for detecting smoke within a compact footprint detector of claim 1, further comprising a first light emitting diode having a spectral intensity centered at a first wavelength λ 1.

6. The device for detecting smoke within a compact footprint detector of claim 5, further comprising an array of optical deflecting elements disposed in a circle around an outer radius of the cap.

7. The device for detecting smoke within a compact footprint detector of claim 6, in which the array of optical deflecting elements is wing shaped.

8. The apparatus for detecting smoke within a compact footprint detector of claim 6, further comprising an anti-reflective coating disposed on at least one of the cap and the array of optical deflecting elements.

9. The device for detecting smoke in a compact footprint detector of claim 6, wherein the coating is centered at the first wavelength λ 1.

10. The device for detecting smoke within a compact footprint detector of claim 1, further comprising a substrate, wherein the cap is mechanically coupled to the substrate.

11. An apparatus for detecting smoke within a compact footprint detector that propagates light away from a smoke detector chamber, comprising:

means for providing light from a first light source;

means for detecting light on a first photodetector disposed proximate the first light source;

means for receiving a first signal from a first photodetector;

means for determining the presence of smoke based at least in part on the received first signal at least in part from the scattering particulate matter; and the combination of (a) and (b),

means for reflecting light using a cap that geometrically reflects light away from the first photodetector.

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