Method of detecting the clogging of a filter installed in a washing machine

• US 5,714,939 A
• Filed: 09/25/1996
• Issued: 02/03/1998
• Est. Priority Date: 09/29/1995
• Status: Expired due to Fees

• Current Assignee: Daewoo Electronics (Government of South Korea)
• Original Assignee: Daewoo Electronics (Government of South Korea)
• Inventors: Song, Bok-Nam
• Primary Examiner(s): Swarthout, Brent A.
• Assistant Examiner(s): TRIEU, VAN THANH
• Application Number:
  US08/719,884
• Time in Patent Office: 496 Days
• Field of Search: 340/618, 340/623, 340/626, 340/450, 340/612, 340/620, 340/607, 68/12.05, 68/12.13, 68/12.21, 68/12.27, 68/207, 137/387, 137/395, 137/551
• US Class Current: 340/607
• CPC Class Codes: D06F 39/082 detecting faulty draining operations, e.g. filter blockage, faulty pump
• CPC Class Codes: D06F 39/10 Filtering arrangements

Abstract

Disclosed is a method of detecting the clogging of a filter installed in a washing machine by which a user can recognize the clogging of the filter. The method comprises the steps of detecting a first frequency using a liquid level sensor when a liquid level in an outer tub has reached a first liquid level, of recording a value of the first frequency in a memory section of the microcomputer, of demoting a second frequency using the liquid level sensor when a liquid level in the outer tub has reached a second liquid level which is formed in the outer tub while the washing cycle is being executed, of recording a value of the second frequency in the memory section of the microcomputer, of calculating a value of a third frequency by subtracting the value of the first frequency from the value of the second frequency, and of sending an operating signal to a signal lamp when the value of the third frequency is lower than a predetermined frequency range which is preset in the microcomputer. By the method, the user can recognize the clogging of the filter without disassembling the filter from the washing machine and without checking the interior of the filter, so the user does not need to frequently check and clean the filter by disassembling the filter from the washing machine.

Claims

1. A method of detecting a clogging of a filter installed in a water-flowing path of a washing machine having an outer tub for receiving a washing liquid, a spin tub rotatably accommodated in the outer tub, a pulsator mounted on a bottom wall of the spin tub, a circulation pump for circulating the washing liquid into an upper portion of the outer tub, a microcomputer, and a liquid level sensor which sends various frequency data based on liquid levels in the outer tub to the microcomputer, the method comprising steps of:

(1) feeding the washing liquid from a liquid source into the outer tub;

(2) detecting a first frequency using the liquid level sensor when a liquid level in the outer tub has reached a first liquid level which is appropriate for washing an article to be washed and recording a value of the first frequency in a memory section of the microcomputer;

(3) performing a washing cycle by rotating the pulsator;

(4) detecting a second frequency using the liquid level sensor when a liquid level in the outer tub has reached a second liquid level which is formed in the outer tub while the washing cycle is being executed, and recording a value of the second frequency in the memory section of the microcomputer;

(5) calculating a value of a third frequency by subtracting the value of the first frequency from the value of the second frequency; and

(6) sending an operating signal to a signal lamp when the value of the third frequency is lower than a predetermined frequency range which is preset in the microcomputer.

2. The method as claimed in claim 1, wherein the washing liquid circulates into the upper portion of the outer tub through the circulation pump and then is sprayed onto the article while step (3) is being executed.

3. The method as claimed in claim 1, further comprising the step of determining whether or not the value of the third frequency is within the predetermined frequency range between steps (5) and (6).

4. The method as claimed in claim 1, further comprising the steps of:

(7) determining whether or not the washing cycle has been completed;

(8) performing rinsing and dehydrating cycles; and

(9) draining the washing liquid out of the washing machine.

5. The method is claimed in claim 4, wherein steps (3) to (7) are repeated when the washing cycle has not been completed in step (7).

6. A method of detecting a clogging of a filter installed in a water-flowing path of a washing machine having an outer tub for receiving a washing liquid, a spin tub rotatably accommodated in the outer tub, a pulsator mounted on a bottom wall of the spin tub, a circulation pump for circulating the washing liquid into an upper portion of the outer tub, a microcomputer, and a liquid level sensor which sends various frequency data based on liquid levels in the outer tub to the microcomputer, the method comprising the steps of:

(1) feeding the washing liquid from a liquid source into the outer tub until a liquid level in the outer tub has reached a first liquid level which is appropriate for washing an article to be washed;

(2) detecting a first frequency based on the first liquid level using the liquid level sensor, and recording a value of the first frequency in a memory section of the microcomputer;

(3) performing a washing cycle by rotating the pulsator;

(4) detecting a second frequency using the liquid level sensor when a liquid level in the outer tub has reached a second liquid level which is formed in the outer tub while the washing cycle is being executed, and recording a value of the second frequency in the memory section of the microcomputer;

(5) calculating a value of a third frequency by subtracting the value of the first frequency from the value of the second frequency;

(6) determining whether or not the value of third frequency is within the predetermined frequency range;

(7) sending an operating signal to a signal lamp when the value of the third frequency is lower than a predetermined frequency range which is preset in the microcomputer.

7. The method as claimed in claim 6, wherein the washing liquid circulates into the upper portion of the outer tub through the circulation pump and then is sprayed onto the article while step (3) is being executed.

8. The method as claimed in claim 6, further comprising the steps of:

(8) determining whether or not the washing cycle has been completed;

(9) performing rinsing and dehydrating cycles; and

(10) draining the washing liquid out of the washing machine.

9. The method as claimed in claim 8, wherein steps (3) to (8) are repeated when the washing cycle has not been completed in step (7).

10. A method of detecting a clogging of a filter installed in a water-flowing path of a washing machine having an outer tub for receiving a washing liquid, a spin tub rotatably accommodated in the outer tub, a pulsator mounted on a bottom wall of the spin tub, a circulation pump for circulating the washing liquid into an upper portion or the outer tub, a microcomputer, and a liquid level sensor which sends various frequency data based on liquid levels in the outer tub to the microcomputer, the method comprising the steps of:

(1) feeding the washing liquid from a liquid source into the outer tub until a liquid level in the outer tub has reached a first liquid level which is appropriate for washing an article to be washed;

(2) detecting a first frequency base on the first liquid level using the liquid level sensor, and recording a value of the first frequency in a memory section of the microcomputer;

(3) performing a washing cycle by rotating the pulsator while spraying the washing liquid onto the article by circulating the washing liquid into the upper portion of the outer tub through the circulation pump;

(4) detecting a second frequency using the liquid level sensor when a liquid level in the outer tub has reached a second liquid level which is formed in the outer tub while the washing cycle is being executed, and recording a value of the second frequency in the memory section of the microcomputer;

(5) calculating a value of a third frequency by subtracting the value of the first frequency from the value of the second frequency;

(6) determining whether or not the value of the third frequency is within the predetermined frequency range;

(7) sending an operating signal to a signal lamp when the value of the third frequency is lower than a predetermined frequency range which is preset in the microcomputer;

(8) determining whether or not the washing cycle has been completed;

(9) repeating steps (3) to (8) when the washing cycle has not been completed in step (8);

(10) performing rinsing and dehydrating cycles; and

(11) draining the washing liquid out of the washing machine.