Lens cleaning method for a surveillance camera

• US 10,005,108 B2
• Filed: 10/17/2016
• Issued: 06/26/2018
• Est. Priority Date: 10/17/2016
• Status: Active Grant

• Current Assignee: Bosch Security Systems Incorporated (Robert Bosch GmbH), Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Dannan, Benjamin
• Primary Examiner(s): CARRILLO, BIBI SHARIDAN
• Application Number:
  US15/295,026
• Publication Number:
  US 20180104721A1
• Time in Patent Office: 617 Days
• CPC Class Codes: B08B 1/10 characterised by the type of cleaning tool
• CPC Class Codes: B08B 1/143 Wipes
• CPC Class Codes: B08B 1/16 Rigid blades, e.g. scrapers; Flexible blades, e.g. wipers
• CPC Class Codes: B08B 1/165 Scrapers
• CPC Class Codes: B08B 3/00 Cleaning by methods involving the use or presence of liquid or steam B08B9/00 takes precedence
• CPC Class Codes: B60R 2001/1253 with cameras, video cameras or video screens
• CPC Class Codes: B60S 1/0848 Cleaning devices for cameras on vehicle
• CPC Class Codes: G02B 27/0006 with means to keep optical surfaces clean, e.g. by preventing or removing dirt, stains, contamination, condensation G02B1/18 takes precedence; cleaning in general B08B
• CPC Class Codes: G03B 17/00 Details of cameras or camera bodies; Accessories therefor lens hoods or caps G03B11/04
• CPC Class Codes: H04N 7/183 for receiving images from a single remote source

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.

Claims

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.

2. The method of claim 1, further comprising:

activating, with the controller, a third device when the digital capacitance value is less than the second threshold value and exceeds a third threshold value that is less than the second threshold value, wherein the third device is at least one of the lens wiper, the lens defroster and the lens sprayer; and

cleaning the lens with the third device.

3. The method of claim 1, wherein activating the first device includes activating the lens defroster, and wherein activating the second device includes activating the lens wiper, the method further comprising:

defrosting the lens with the lens defroster after the lens defroster is activated; and

wiping the lens with the lens wiper after the lens wiper is activated.

4. The method of claim 1, further comprising:

sensing, with a temperature sensor, a temperature of the lens,

wherein activating the first device includes activating the first device when the sensed temperature exceeds a temperature threshold; and

cleaning the lens with the first device.

5. The method of claim 2, wherein activating the first device includes activating the lens defroster, wherein activating the second device includes activating the lens sprayer, and wherein activating the third device includes activating the lens wiper, and wherein the method further comprises:

defrosting the lens with the lens defroster after the lens defroster is activated;

spraying the lens with the lens sprayer after the lens sprayer is activated; and

wiping the lens with the lens wiper after the lens wiper is activated.

6. The method of claim 4, further comprising:

controlling power to the lens defroster to maintain the power of the lens defroster below a power threshold, including turning on the power to the lens defroster for a first time period and then turning off the power to the lens defroster for a second time period.

7. The method of claim 5, further comprising:

sensing, with a temperature sensor, a temperature of the lens,

wherein activating the first device includes activating the lens defroster when the sensed temperature exceeds a temperature threshold; and

defrosting the lens with the lens defroster.

8. The method of claim 7, further comprising:

controlling power to the lens defroster to maintain the power of the lens defroster below a power threshold, including turning on the power to the lens defroster for a first time period and then turning off the power to the lens defroster for a second time period.

9. A method for cleaning a lens of a surveillance camera, comprising:

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.

10. The method of claim 9, further comprising:

sensing, with a temperature sensor, a temperature of the lens; and

controlling power to at least one of the first device and the second device when the sensed temperature exceeds a temperature threshold, including turning on the power to the at least one of the first device and the second device for a first time period and then turning off the power to the at least one of the first device and the second device for a second time period.

11. The method of claim 9, further comprising:

controlling power to at least one of the first device and the second device to maintain power to the at least one of the first device and the second device below a power threshold, including turning on the power to the at least of the first device and the second device for a first time period and then turning off the power to the at least one of the first device and the second device for a second time period.