# US 8,540,822 B2 · Control method of a dishwasher

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- Number: US 8,540,822 B2
- Document ID: US8540822B2
- Status: Granted
- Kind: B2
- Application number: 12/827,160
- Filed: 2010-06-30
- Published: 2011-06-02
- Granted: 2013-09-24
- Earliest claimed: 2009-12-02
- Assignees: LG Electronics Inc.
- Applicants: Joonho Pyo; Taehee Lee; Simoon Jeon; Gapsu Shin
- Inventors: Joonho Pyo; Taehee Lee; Simoon Jeon; Gapsu Shin
- Web page: https://patentgrep.com/patent/US8540822B2

## CPC

- A47L 15/4208: {Arrangements to prevent clogging of the filters, e.g. self-cleaning}
- A47L 2401/20: Time, e.g. elapsed operating time
- A47L 2501/03: Water recirculation, e.g. control of distributing valves for redirection of water flow
- A47L 2501/05: Drain or recirculation pump, e.g. regulation of the pump rotational speed or flow direction
- A47L: DOMESTIC WASHING OR CLEANING (brushes A46B; cleaning quantities of bottles or of other hollow articles of one kind B08B9/00; laundry D06F); SUCTION CLEANERS IN GENERAL (cleaning in general B08)

## Abstract

A control method of a dishwasher is provided in which a filter is cleaned by controlling an operation of a washing pump. In this control method, washing fluid pumped by the washing pump back flows and is directed to the filter so as to remove foreign materials accumulated in the filter from the filter.

## Claims

### Claim 1

A control method of a dishwasher, the method comprising:
driving a washing pump to pump washing fluid to direct the washing fluid in a sump into a washing fluid guide;
driving a draining pump before stopping pumping of the washing fluid, driving the draining pump comprising:
initiating driving the draining pump after a first set time has elapsed since initiating the pumping of the washing fluid; and
driving the draining pump to adjust a level of the washing fluid stored in the sump while continuing to pump the washing fluid;
stopping the driving of the washing pump after a second set time has elapsed since initiating the driving of the draining pump to generate a back flow of washing fluid in the washing fluid guide to the washing pump; and
allowing the back flow of washing fluid to splash onto a filter to separate particles from the filter.

### Claim 2 (depends on 1)

The method of claim 1, further comprising, after a third set time has elapsed after stopping the driving of the washing pump and impinging the back flow of washing fluid onto the filter, driving the washing pump to a set rotating speed that is less than a maximum rotating speed.

### Claim 3 (depends on 2)

The method of claim 2, further comprising stopping the driving of the washing pump when the washing pump reaches the set rotating speed, and thereafter stopping the driving of the draining pump.

### Claim 4 (depends on 1)

The method of claim 1, further comprising setting a channel controller and stopping a driving of a washing pump so as to stop the pressurization of the washing fluid, comprising switching a valve in the washing fluid guide to an upper nozzle supply mode and stopping the pressurization of the washing fluid by stopping a driving of the washing pump after a fourth set time has elapsed since initiating the driving of the washing pump.

### Claim 5 (depends on 4)

The method of claim 4, further comprising:
after a fifth set time has elapsed since stopping the driving of the washing pump, driving the washing pump to a set rotating speed that is less than a maximum rotating speed; and
stopping the driving of the washing pump when the washing pump reaches the set rotating speed, and thereafter driving the draining pump.

### Claim 6 (depends on 1)

The method of claim 1, further comprising setting a channel controller and stopping the pressurization of the washing fluid by stopping a driving of a washing pump, and switching a valve in the washing fluid guide to an upper nozzle supply mode and stopping the driving of the washing pump after a sixth set time has elapsed since initiating the driving of the washing pump.

### Claim 7 (depends on 6)

The method of claim 6, further comprising:
driving the washing pump again and driving the draining pump; and
after a seventh set time has elapsed since driving the washing pump again, re-setting the channel controller to the first direction and stopping the driving of the washing pump, and thereafter stopping the driving of the draining pump.

### Claim 8 (depends on 1)

The method of claim 1, wherein a pump inlet is provided between the filter and a washing pump provided at the sump, and wherein the pump inlet tilts upward toward the filter from the washing pump.

### Claim 9 (depends on 8)

The method of claim 8, wherein allowing the back flowing washing fluid to splash onto the filter comprises directing the washing fluid to a center of the filter through the pump inlet.

### Claim 10 (depends on 8)

The method of claim 8, wherein allowing the back flowing washing fluid to splash onto the filter comprises directing the washing fluid in a direction away from a center of the filter.

### Claim 11 (depends on 1)

The method of claim 1, wherein allowing the back flowing washing fluid to splash onto the filter further comprises discharging the washing fluid and the particles separated from the filter.

### Claim 12

A method of controlling a dishwasher, the method comprising:
initiating a driving of a washing pump so as to direct washing fluid into a washing space;
when a first set time has elapsed since initiating the driving of the washing pump, initiating a driving of a draining pump;
when a second set time has elapsed since initiating the driving of the draining pump, interrupting power supplied to the washing pump;
directing a back flow of washing fluid from a washing fluid guide to a filter provided in a sump so as to dislodge particles from the filter;
switching a valve in the washing fluid guide to an upper or top nozzle mode when the second set time has elapsed, and
wherein directing a back flow of washing fluid from a washing fluid guide to a filter comprises:
providing washing fluid up to a predetermined level in the washing fluid guide in response to a pumping force generated by the washing pump; and
allowing the washing fluid accumulated in the washing fluid guide to flow back to the washing pump and to the filter in the sump when power to the washing pump is interrupted and the pumping force of the washing pump is no longer generated.

### Claim 13 (depends on 12)

The method of claim 12, further comprising, after a third set time has elapsed after interrupting power supplied to the washing pump, re-supplying power to the washing pump to drive the washing pump to a set rotating speed that is less than a maximum rotating speed.

### Claim 14 (depends on 13)

The method of claim 13, further comprising interrupting power to the washing pump when the washing pump reaches the set rotating speed, and thereafter interrupting power supplied to the draining pump.

### Claim 15 (depends on 12)

The method of claim 12, further comprising switching a valve in the washing fluid guide to an upper nozzle supply mode when interrupting power supplied to the washing pump.

### Claim 16 (depends on 15)

The method of claim 15, further comprising:
after interrupting power to the washing pump and directing the back flow of washing fluid onto the filter, re-supplying power to the washing pump to drive the washing pump to a set rotating speed that is less than a maximum rotating speed; and
interrupting power supplied to the washing pump when the washing pump reaches the set rotating speed, and thereafter supplying power to the draining pump.

### Claim 17 (depends on 12)

The method of claim 12, wherein interrupting power supplied to the washing pump comprises interrupting power supplied to the washing pump when level of washing fluid in the washing water guide is greater than a height of a lowermost nozzle of a plurality of nozzles positioned in the washing space.

### Claim 18

A method of controlling a dishwasher, the method comprising:
performing a pre-washing cycle;
performing a main washing cycle; and
performing a filter cleaning cycle at least once during the pre-washing cycle and at least once during the main washing cycle,
wherein performing a filter cleaning cycle comprises:
setting a valve positioned in a washing fluid guide in a first direction and supplying washing fluid from a sump into the washing fluid guide to a predetermined level in response to a pumping force generated by a washing pump;
stopping a supply of power to the washing pump to cause the washing fluid accumulated in the washing fluid guide flow back to the washing pump; and
impinging the back flow of washing fluid onto a filter provided in the sump so as to separate particles from the filter.