System for detecting an item within a specified zone
First Claim
1. A specified zone detection system comprising:
- an image acquisition module situated at a specified zone, wherein the specified zone is defined adjacent a fume hood having an operable sash;
a presence determination module connected to the image acquisition module;
wherein;
the image acquisition module provides a current image of the specified zone;
the presence determination module comprises a reference image source;
the reference image source provides a reference image of the specified zone without a person present in the specified zone;
the presence determination module indicates from a comparison of the current image and the reference image whether there is a person present in the specified zone; and
if the sash of the fume hood is open and the presence determination module cannot determine whether or not there is a person present in the specified zone, adjusting the airflow in the specified zone to assure that the specified zone is environmentally safe;
an illumination controller connected to the presence determination module;
an illumination module connected to the illumination controller;
an ambient light sensor in the specified zone;
a lighting arrangement situated at the specified zone; and
wherein;
the ambient light sensor detects a magnitude of light in the specified zone; and
if the magnitude of light is less than a predetermined level, then the lighting arrangement provides infrared light in the specified zone to increase the magnitude of light to at least the predetermined level.
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Accused Products
Abstract
The disclosure reveals a system for detecting one or more persons in a specified zone. A determination is whether there is a person in the zone. A presence determination module may indicate from a current image of the zone compared with a reference image of the zone, whether there is a person in or not in the zone. An illumination controller may assure that the zone is sufficiently illuminated for a current image sufficient for comparison with the reference image to determine a possible presence of a person in the zone. The illumination may be infrared. The system may be used to assure appropriate and adequate face velocity at a fume hood having the presence of a person and having minimal face velocity in the absence of a person at the fume hood.
20 Citations
17 Claims
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1. A specified zone detection system comprising:
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an image acquisition module situated at a specified zone, wherein the specified zone is defined adjacent a fume hood having an operable sash; a presence determination module connected to the image acquisition module; wherein; the image acquisition module provides a current image of the specified zone; the presence determination module comprises a reference image source; the reference image source provides a reference image of the specified zone without a person present in the specified zone; the presence determination module indicates from a comparison of the current image and the reference image whether there is a person present in the specified zone; and if the sash of the fume hood is open and the presence determination module cannot determine whether or not there is a person present in the specified zone, adjusting the airflow in the specified zone to assure that the specified zone is environmentally safe; an illumination controller connected to the presence determination module; an illumination module connected to the illumination controller; an ambient light sensor in the specified zone; a lighting arrangement situated at the specified zone; and wherein; the ambient light sensor detects a magnitude of light in the specified zone; and if the magnitude of light is less than a predetermined level, then the lighting arrangement provides infrared light in the specified zone to increase the magnitude of light to at least the predetermined level. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A method for determining a presence of a person in a zone, comprising:
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capturing a current image of a specified zone, wherein the specified zone is defined adjacent a fume hood having an operable sash; capturing a reference image of the specified zone without any person present in the specified zone; comparing the current image of the specified zone with the reference image of the specified zone; seeking one or more differences between the current image and the reference image; determining whether the one or more of the differences exhibit a person in the specified zone; providing and adjusting an airflow in the specified zone to a first level to assure that the specified zone is environmentally safe if a person is determined to be in the specified zone and the fume hood sash is open; reducing the airflow in the specified zone from the first level to a second level if there is determined to be an absence of a person in the specified zone and the fume hood sash is open, wherein the second level of airflow is more economical than the first level of airflow, but maintains environmental safety in the specified zone; monitoring the lighting in the specified zone to assure that the current image of the specified zone has sufficient quality for comparing the current image with the reference image; and providing lighting as needed of the specified zone to assure that the current image of the specified zone has sufficient quality for comparing the current image with the reference image. - View Dependent Claims (12, 13)
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14. A presence sensor system comprising:
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an image acquisition module situated in a fume hood operator zone of a fume hood having an operable sash; a microprocessor connected to the image acquisition module; and an illumination module connected to the microcontroller; and wherein; the microprocessor does a comparison of a current image of the operator zone from the image acquisition module with a reference image of the operator zone to determine if there is an item in the current image that is absent in the reference image; the comparison of the current and reference images is made on a pixel by pixel basis; the microprocessor provides an output based on pixel differences between the current and reference images to determine if there is an item in the current image that is absent in the reference image; the illumination module provides infrared lighting at fume hood operator zone as needed for the microcontroller to do a comparison of a current image of the operator zone from the image acquisition module with a reference image of the operator zone to determine if there is an item in the current image that is absent in the reference images; and wherein; if an item is determined to be present in the fume hood zone and the fume hood sash is open, a face velocity is increased to a safe level; if an item is determined to be absent from the fume hood zone and the fume hood sash is open, the face velocity is decreased to an energy-saving level, wherein the face velocity at the safe level is greater than the face velocity at the energy-saving level. - View Dependent Claims (15, 16, 17)
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Specification