Non-radioactive ionizing smoke detectors and methods for use thereof
AssigneeGoogle Inc.
InventorAndrew W. Goldenson
Life of this patent
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Abstract
A smoke detector according to various embodiments discussed herein can use a non-radioactive ionization technique to detect the presence of smoke and/or other particulate matter. A non-radioactive ionizing detector may use a LED such as an ultraviolet light emitting diod in combination with a pair of conductive plates, one of which is coated with a photocatalyst coating. When the light strikes the photocatalyst coating, ions can be generated that change a charge characteristic of the photocatalytic coated plate. The occurrence of an alarm can be detected based on a measured charge magnitude existing between the two plates.
Claims19
A non-radioactive ionizing smoke detection system, comprising:
- a chamber having an interior volume and at least one opening to an ambient environment;
- a pair of conductive plates contained in the interior volume, wherein one of the plates is coated with a photocatalytic coating;
- a light source contained in the interior volume and aimed to emit electromagnetic energy towards the photocatalytic coated plate;
- circuitry coupled to the conductive plates and the light source, the circuitry operative to:
- activate the light source to emit electromagnetic energy that strikes the photocatalytic coated plate, the electromagnetic energy causing ions to be generated when it strikes the photocatalytic coated plate, wherein the ions alter a charge characteristic of the photocatalytic coated plate;
- monitor a charge magnitude between the conductive plates to determine whether an alarm event is detected.
A non-radioactive ionizing smoke detection system, comprising:
- a chamber having an interior volume and at least one opening to an ambient environment;
- a photocatalytic coated conductive plate and a reference conductive plate contained in the interior volume;
- a photodiode contained in the interior volume;
- a light source contained in the interior volume, the light source comprising:
- an ultraviolet (UV) light emitting diode (LED);
- and
- an infrared (IR) LED;
- circuitry coupled to the conductive plates, the light source, and the photodiode, the circuitry operative to:
- use an ion-based detection scheme to monitor for presence of particulate matter within the chamber;
- and
- use a light scattering detection scheme to monitor for presence of particulate matter within the chamber.
A method for detecting particles in a non-radioactive ionizing hazard detector system comprising a light source, a photocatalytic plate, and a reference plate, the method comprising:
- activating the light source to emit electromagnetic energy that is aimed to strike the photocatalytic plate, the electromagnetic energy causing ions to be generated when it strikes the photocatalytic plate, wherein the ions alter a charge characteristic of the photocatalytic plate;
- monitoring a charge magnitude across the photocatalytic plate and the reference plate while the light source is activated;
- determining whether the charge magnitude exceeds an alarm threshold;
- and
- activating an alarm if the charge magnitude is below the alarm threshold.
Dependencies are inferred from the claim text.