Defrosting system and method of refrigeration

• US 9,423,169 B2
• Filed: 10/22/2010
• Issued: 08/23/2016
• Est. Priority Date: 10/22/2009
• Status: Active Grant

• Current Assignee: LG Innotek Company Limited (LG Corporation)
• Original Assignee: LG Innotek Company Limited (LG Corporation)
• Inventors: Kim, Seoyoung
• Primary Examiner(s): Bauer, Cassey D
• Assistant Examiner(s): Zerphey, Christopher R
• Application Number:
  US12/909,921
• Publication Number:
  US 20110094245A1
• Time in Patent Office: 2,132 Days
• Field of Search: 621/28, 621/50, 621/51, 621/54, 621/55, 374/130, 356/43, 250/330
• US Class Current: 1/1
• CPC Class Codes: F25D 21/02 Detecting the presence of frost or condensate

Abstract

Disclosed is a defrosting system and a defrosting method of a refrigerator, the system including an evaporator configured to reduce an ambient temperature by heat exchange through movement of refrigerant, a frost monitoring camera by photographing a state of frost adhered to the evaporator, a controller configured to grasp changes of an image captured by the frost monitoring camera to determine a defrosting start time, and a heat-generating unit configured to emit heat in response to a signal applied from the controller to remove the frost, whereby an unnecessary operation of a heat-generating unit is prevented by appropriately coping with an environment that flexibly changes according to an inner situation of a refrigerator and by accurately determining, by the controller, a start time and a completion time of defrosting operation for removing frost adhered to the refrigerator.

Claims

1. A method of defrosting for a refrigerator including an evaporator, the method comprising the steps of:

activating an illumination unit for photographing by a frost monitoring camera;

emitting light to a portion of the evaporator;

photographing an image of the portion of the evaporator at a time interval with the frost monitoring camera; and

determining whether a gray scale change value of the image photographed is greater than a predetermined threshold value through a controller, wherein the gray scale change value is a change value of gray scale color determined in an RGB value of the photographed image at a photograph start time as time lapses;

wherein the controller is configured to;

compare colors obtained from the photographed image of the portion of the evaporator with colors obtained from a reference image of the portion of the evaporator, wherein the reference image is an image when the camera is initiated;

determine a defrosting start time and a defrosting completion time based on the comparison of the colors, wherein a gray color, a black color, or a white color in the photographed image of the portion of the evaporator is compared with the reference image; and

operate a heat-generating unit for a defrosting operation in response to determination by the controller.

2. The method of claim 1, wherein the controller is configured to determine the defrosting start time when:

the gray color in the image of the portion of the evaporator is greater than that of the reference image;

the black color in the image of the portion of the evaporator is less than that of the reference image;

or

the white color in the image of the portion of the evaporator is greater than that of the reference image.

3. The method of claim 2, wherein the controller is configured to determine the defrosting completion time when:

the gray color in the image of the portion of the evaporator is less than that of the reference image;

the black color in the image of the portion of the evaporator is greater than that of the reference image;

or

the white color in the image of the portion of the evaporator is less than that of the reference image.

4. The method of claim 1, wherein the heat-generating unit is a heater configured to generate heat, or a steam generator configured to inject steam.

5. The method of claim 4, wherein the illumination unit is activated only for photographing by the camera and is turned off with a power-off of the camera.

6. The method of claim 5, further comprising removing an embedded humidity of the frost monitoring camera or a frost generated inside the frost monitoring camera by turning on the power of the frost monitoring camera, when the power of the frost monitoring camera is turned off over a predetermined period of time.

7. The method of claim 1, wherein the controller is configured to determine the defrosting completion time when:

the gray color in the image of the portion of the evaporator is less than that of the reference image;

the black color in the image of the portion of the evaporator is greater than that of the reference image;

or

the white color in the image of the portion of the evaporator is less than that of the reference image.

8. The method of claim 1, wherein the image of the portion of the evaporator includes a still image and is obtained periodically at predetermined time intervals.

9. The method of claim 1, wherein the image of the portion of the evaporator includes a moving image and is obtained periodically at predetermined time intervals.

10. The method of claim 1, wherein the controller compares a photographing start time of the frost monitoring camera with an RGB value of an image captured at a predetermined time interval to determine the defrosting start time.

11. The method of claim 1, wherein the controller compares the defrosting start time of the heat generating unit with an RGB value of an image captured at a pre-set time interval to determine the defrosting completion time.