Lens cleaning method for a surveillance camera
First Claim
1. A method for cleaning a lens of a surveillance camera, comprising:
- sensing, with a capacitance sensor, a sensed capacitance of the lens of the surveillance camera, the sensed capacitance indicating the type of foreign object detected on the lens;
converting, with a capacitive to digital converter, the sensed capacitance to a digital capacitance value;
activating, with a controller, a first device when the digital capacitance value exceeds a first threshold value that is greater than a second threshold value, wherein the first device is at least one of a lens wiper, a lens defroster and a lens sprayer;
cleaning the lens with the first device;
activating, with the controller, a second device when the digital capacitance value is less than the first threshold value and greater than the second threshold value, wherein the second device is at least one of the lens wiper, the lens defroster and the lens sprayer; and
cleaning the lens with the second device, wherein the second device is not the same as the first device.
1 Assignment
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Accused Products
Abstract
A cleaning method for a surveillance camera uses a capacitive sensor to determine whether rain, ice, dirt, debris or other foreign objects are present on the camera lens substrate. A determination is made whether the sensed capacitance is greater than a first threshold indicative of the presence of a foreign object on the lens. If a foreign object is indicated, the lens is sprayed with a sprayer and then a wiper is activated. If a foreign object is not indicated, a determination is made whether ice is present by comparing the sensed capacitance to a second threshold that is less than the first threshold. If ice is present, wiper and lens defrosters are activated, and a wiper is then turned on. The cleaning method may include a temperature sensor and power management for the defrosters.
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Citations
11 Claims
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1. A method for cleaning a lens of a surveillance camera, comprising:
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sensing, with a capacitance sensor, a sensed capacitance of the lens of the surveillance camera, the sensed capacitance indicating the type of foreign object detected on the lens; converting, with a capacitive to digital converter, the sensed capacitance to a digital capacitance value; activating, with a controller, a first device when the digital capacitance value exceeds a first threshold value that is greater than a second threshold value, wherein the first device is at least one of a lens wiper, a lens defroster and a lens sprayer; cleaning the lens with the first device; activating, with the controller, a second device when the digital capacitance value is less than the first threshold value and greater than the second threshold value, wherein the second device is at least one of the lens wiper, the lens defroster and the lens sprayer; and cleaning the lens with the second device, wherein the second device is not the same as the first device. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A method for cleaning a lens of a surveillance camera, comprising:
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sensing, with a capacitance sensor, a sensed capacitance of the lens of a surveillance camera, the sensed capacitance indicating the type of foreign object detected on the lens; converting, with a capacitive to digital converter, the sensed capacitance to a first digital capacitance value; activating, with a controller, a first device when the first digital capacitance value exceeds a first threshold value that is greater than a second threshold value, wherein the first device is at least one of a lens wiper, a lens defroster and a lens sprayer; cleaning the lens with the first device; activating, with the controller, a second device when the first digital capacitance value is less than the first threshold value and greater than the second threshold value, wherein the second device is at least one of the lens wiper, the lens defroster and the lens sprayer; cleaning the lens with the second device, wherein the second device is not the same as the first device; sensing, with the capacitance sensor, a second sensed capacitance of the lens; converting, with the capacitive to digital converter, the second sensed capacitance to a second digital capacitance value; activating, with the controller, the first device when the second digital capacitance value exceeds the first threshold value; cleaning the lens with the first device; activating, with the controller, the second device when the second digital capacitance value is less than the first threshold value and greater than the second threshold value; and cleaning the lens with the second device. - View Dependent Claims (10, 11)
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Specification