Dishwasher and control method thereof

• US 20060060226A1
• Filed: 03/28/2005
• Published: 03/23/2006
• Est. Priority Date: 09/22/2004
• Status: Abandoned Application

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Choi, Soung Bong, Han, Dae Yeong, Yoon, Sang Heon, Park, Nung Seo
• Application Number:
  US11/090,304
• Publication Number:
  US 20060060226A1
• Time in Patent Office: Days
• US Class Current: 134/56.D
• CPC Class Codes: A47L 15/4297 Arrangements for detecting or measuring the condition of the washing water, e.g. turbidity
• CPC Class Codes: A47L 2401/10 Water cloudiness or dirtiness, e.g. turbidity, foaming or level of bacteria
• CPC Class Codes: A47L 2501/01 Water supply, e.g. opening or closure of the water inlet valve
• CPC Class Codes: A47L 2501/02 Water discharge, e.g. opening or closure of discharge valve
• CPC Class Codes: A47L 2501/05 Drain or recirculation pump, e.g. regulation of the pump rotational speed or flow direction
• CPC Class Codes: A47L 2501/30 Regulation of machine operational steps within the washing process, e.g. performing an additional rinsing phase, shortening or stopping of the drying phase, washing at decreased noise operation conditions
• CPC Class Codes: G01N 1/20 for flowing or falling materials G01N1/2035 G01N1/12, G01N1/14 take precedence
• CPC Class Codes: G01N 1/40 Concentrating samples

Abstract

The present invention provides a dishwasher and control method thereof, in which a contamination level of water is decided to prevent waste of the water and to appropriately control a washing time. The present invention includes a sump for receiving water, a washing pump for pumping the water received in the sump, a filter for filtering the water pumped by the washing pump, and a contamination level sensor for measuring a contamination level of the water, wherein the contamination level sensor is located on a sampling passage through which washing water passes in route to a drain chamber.

Claims

1. A dishwasher, comprising:

a sump for receiving water;

a washing pump for pumping the water received in the sump;

a filter for filtering the water pumped by the washing pump; and

a contamination level sensor for measuring a contamination level of the water, wherein the contamination level sensor is located on a sampling passage through which washing water passes in route to a drain chamber.

2. The dishwasher of claim 1, the filter comprises:

a lower housing having a contaminant collection chamber;

an upper housing having the sampling passage; and

a cover covering a topside of the sump, the cover comprising;

a filter screen located above the contaminant collection chamber; and

a recovery hole on a periphery of the sump to receive the washing water.

3. The dishwasher of claim 2, wherein the contamination collection chamber and the sampling passage communicate through a coupling portion of the lower housing and a perforated hole formed at an end of the sampling passage of the upper housing.

4. The dishwasher of claim 3, wherein the coupling portion is connected to the perforated hole to provide a first passage for the washing water to flow, and the coupling portion is further provided with a second passage for the washing water to overflow to the contamination collection chamber.

5. The dishwasher of claim 4, wherein the first passage of the coupling portion comprises an inner duct which has a smaller circumference than that of the coupling portion to permit the washing water to overflow via the second passage which is a passage between an outer surface area of the inner duct and an inner surface area of the coupling portion.

6. The dishwasher of claim 2, wherein the coupling portion communicates with the drain chamber as well as the contaminant collection chamber.

7. The dishwasher of claim 1, wherein the contamination level sensor comprises an optical sensor having a light-receiving unit and a light-emitting unit.

8. The dishwasher of claim 7, wherein the optical sensor has an exterior formed by cutting a cylinder vertically into halves and leaving a prescribed distance between the halves that are the light-receiving and light-emitting units, respectively.

9. The dishwasher of claim 1, wherein the sampling passage receives a specified amount of washing water not provided to spray arms.

10. A dishwasher, comprising:

a sump for receiving water;

a washing pump for pumping the water received in the sump;

a drain pump for draining the water received in the sump; and

a filter provided to the sump, the filter comprises;

a contaminant collection chamber for filtering the washing water;

a sampling passage for guiding a portion of the water pumped by the washing pump to the contaminant collection chamber; and

a contamination level sensor for measuring a contamination level of the washing water on the sampling passage.

11. The dishwasher of claim 10, wherein the contamination level sensor comprises an optical sensor having a light-receiving unit and a light-emitting unit.

12. The dishwasher of claim 11, wherein the optical sensor has an exterior formed by cutting a cylinder vertically into halves and leaving a prescribed distance between the halves that are the light-receiving and light-emitting units, respectively.

13. The dishwasher of claim 10, the filter comprises:

a lower housing having a contaminant collection chamber;

an upper housing having the sampling passage; and

a cover covering a topside of the sump, the cover comprising;

a filter screen located above the contaminant collection chamber; and

a recovery hole on a periphery of the sump to receive the washing water.

14. The dishwasher of claim 13, wherein the contamination collection chamber and the sampling passage communicate through a coupling portion of the lower housing and a perforated hole formed at an end of the sampling passage of the upper housing.

15. The dishwasher of claim 14, wherein the coupling portion is connected to the perforated hole to provide a first passage for the washing water to flow, and the coupling portion is further provided with a second passage for the washing water to overflow to the contamination collection chamber.

16. The dishwasher of claim 15, wherein the first passage of the coupling portion comprises an inner duct which has a smaller circumference than that of the coupling portion to permit the washing water to overflow via the second passage which is a passage between an outer surface area of the inner duct and an inner surface area of the coupling portion.

17. The dishwasher of claim 13, wherein the coupling portion communicates with the drain chamber as well as the contaminant collection chamber.

18. A method of controlling a dishwasher, comprising:

starting a washing pump;

detecting a contamination level of washing water;

correcting a washing time previously set in a control unit based on the detected contamination level; and

operating the washing pump according to the corrected washing time.

19. The method of claim 18, wherein the contamination level of the water is detected if a predetermined time expires after starting the washing pump.

20. A method of controlling a dishwasher, comprising:

starting a washing pump;

detecting a contamination level of washing water;

draining a portion of the washing water by driving a drain pump if the detected contamination level exceeds a contamination level previously set by a control unit; and

adding a specified amount of new water in proportion to the drained amount to the washing water.

21. The method of claim 20, wherein the contamination level of the water is detected if a predetermined time expires after starting the washing pump.

22. The method of claim 20, wherein the washing pump is stopped in draining the water or in adding the new water.

23. The method of claim 20, wherein a drain quantity of the water is adjusted according to the detected contamination level.

24. The method of claim 20, further comprising:

re-detecting the contamination level of the washing water after the new water added;

correcting the washing time previously set by the control unit based on to the re-detected contamination level; and

operating the washing pump according to the corrected washing time.

25. The method of claim 24, wherein the contamination level of the water having the new water added is re-detected if a predetermined time expires after adding the new water.