U.S. patent application number 12/007980 was filed with the patent office on 2008-10-09 for controlling method of washing machine.
This patent application is currently assigned to SAMSUNG ELECTRONICS CO., LTD.. Invention is credited to Hye Ryung Kim, Tai Eun Kim, Jung Soo Lim, Byoung Yull Yang, Hye Soon Yang.
Application Number | 20080244836 12/007980 |
Document ID | / |
Family ID | 39592857 |
Filed Date | 2008-10-09 |
United States Patent
Application |
20080244836 |
Kind Code |
A1 |
Kim; Tai Eun ; et
al. |
October 9, 2008 |
Controlling method of washing machine
Abstract
A control method of a washing machine reliably guarantees a
rinsing performance, and a minimized number of rinsing cycles is
performed. The method includes: circulating detergent water
collected in a tub through a circulation passage during a washing
cycle; supplying a voltage to a pair of electrodes made of
different materials and installed on the circulation passage to
determine whether a quantity of detergent contained in the
detergent water is excessive; circulating rinsing water collected
in the tub through the circulation passage during a rinsing cycle;
detecting a magnitude (I2) of a current flowing through the rinsing
water by supplying the voltage to the pair of electrodes; and
comparing the detected magnitude (I2) of the current with a
reference value (Ir), and finishing the rinsing cycle when the
detected magnitude (I2) is equal to or less than the reference
value (Ir).
Inventors: |
Kim; Tai Eun; (Suwon-Si,
KR) ; Yang; Hye Soon; (Yongin-Si, KR) ; Yang;
Byoung Yull; (Suwon-Si, KR) ; Lim; Jung Soo;
(Suwon-Si, KR) ; Kim; Hye Ryung; (Yongin-Si,
KR) |
Correspondence
Address: |
STAAS & HALSEY LLP
SUITE 700, 1201 NEW YORK AVENUE, N.W.
WASHINGTON
DC
20005
US
|
Assignee: |
SAMSUNG ELECTRONICS CO.,
LTD.
Suwon-si
KR
|
Family ID: |
39592857 |
Appl. No.: |
12/007980 |
Filed: |
January 17, 2008 |
Current U.S.
Class: |
8/159 ;
8/158 |
Current CPC
Class: |
D06F 34/22 20200201;
D06F 33/00 20130101 |
Class at
Publication: |
8/159 ;
8/158 |
International
Class: |
D06F 33/02 20060101
D06F033/02 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 6, 2007 |
KR |
10-2007-34407 |
Claims
1. A control method of a washing machine of measuring turbidity of
rinsing water and determining whether a rinsing cycle is finished,
comprising: circulating the rinsing water through a circulation
passage; measuring a magnitude of current flowing through the
rinsing water by supplying a voltage to electrodes installed in the
circulation passage; and comparing the detected magnitude (I2) with
a reference value (Ir) and determining whether the rinsing cycle is
finished based on the comparison.
2. The control method of the washing machine according to claim 1,
wherein when the detected magnitude (I2) of the current is equal to
or less than the reference value (Ir), the rinsing cycle is
finished, and when the detected magnitude (I2) of the current is
greater than the reference value (Ir), another rinsing cycle is
added and performed.
3. The control method of the washing machine according to claim 1,
further comprising: circulating detergent water through the
circulation passage during a washing cycle performed prior to the
rinsing cycle; detecting a magnitude (I1) of current flowing in the
detergent water when a voltage is supplied to the electrodes; and
determining whether a quantity of detergent added by a user is
excessive by comparing the detected magnitude (I1) with a reference
value (Iw).
4. The control method of the washing machine according to claim 3,
wherein when the detected magnitude (I1) is equal to or greater
than the reference value (Iw), information that excess detergent
has been added is displayed on a display.
5. The control method of the washing machine according to claim 3,
wherein when the detected magnitude (I1) is equal to or greater
than the reference value (Iw), and a number of rinsing cycle times
is added, and an elongated washing time is displayed on a
display.
6. The control method of the washing machine according to claim 3,
wherein when the detected magnitude (I1) is equal to or greater
than the reference value (Iw), a quantity of the rinsing water to
be supplied at an initial rinsing cycle is re-set.
7. The control method of the washing machine according to claim 1,
wherein the electrodes are made of different materials, and the
control method further comprises changing polarities of the voltage
supplied to the electrodes for a predetermined time before the
rinsing cycle is finished.
8. The control method of the washing machine according to claim 1,
wherein one electrode comprises a silver electrode containing
silver and another electrode comprises a titanium electrode
containing titanium, and the titanium electrode is regarded as a
positive electrode when the voltage is supplied to the
electrodes.
9. The control method of the washing machine according to claim 1,
further comprising: counting a number of rinsing cycle times; and
finishing rinsing based on comparing the counted number of rinsing
cycle times with a maximum number of rinsing cycle times.
10. A control method of a washing machine comprising: circulating
detergent water collected in a tub through a circulation passage
during a washing cycle; supplying a voltage to a pair of electrodes
made of different materials and installed in the circulation
passage to determine whether a quantity of detergent contained in
the detergent water is excessive; circulating rinsing water
collected in the tub through the circulation passage during a
rinsing cycle; detecting a magnitude (I2) of a current flowing
through the rinsing water by supplying the voltage to the pair of
electrodes; and comparing the detected magnitude (I2) of the
current with a reference value (Ir) and finishing the rinsing cycle
when the detected magnitude (I2) is equal to or less than the
reference value (Ir).
11. The control method of the washing machine according to claim
10, further comprising: counting a number of rinsing cycle times;
and finishing the rinsing cycle even when the detected magnitude
(I2) exceeds the reference value (Ir) when the counted number of
rinsing cycle times reaches a maximum number of rinsing cycle
times.
12. The control method of the washing machine according to claim
10, wherein one of the pair of electrodes comprises a silver
electrode containing silver and the other electrode comprises a
titanium electrode containing titanium.
13. The control method of the washing machine according to claim
12, wherein the titanium electrode is a positive electrode when the
voltage is supplied to the pair of electrodes.
14. The control method of the washing machine according to claim
12, wherein the voltage is supplied while using the silver
electrode as a positive electrode for a predetermined time before
the rinsing cycle is finished.
15. The control method of the washing machine according to claim
10, wherein when it is determined that an excessive quantity of the
detergent is contained in the detergent water, information that the
excessive quantity of the detergent is contained in the detergent
water is displayed on a display, and a quantity of the rinsing
water to be supplied at an initial rinsing cycle is re-set.
16. A control method of a washing machine comprising: circulating
detergent water collected in a tub through a circulation passage
during a washing cycle; and supplying a voltage to a pair of
electrodes made of different materials and installed in the
circulation passage to determine whether a quantity of detergent
contained in the detergent water is excessive.
17. The control method of the washing machine according to claim
16, wherein the determining whether a quantity of detergent
contained in the detergent water is excessive comprises: detecting
a magnitude (I1) of a current flowing through the detergent water
by supplying the voltage to the pair of electrodes; and determining
whether a quantity of detergent added by a user is excessive by
comparing the detected magnitude (I1) with a reference value (Iw).
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of Korean Patent
Application No. 2007-034407, filed on Apr. 6, 2007, in the Korean
Intellectual Property Office, the disclosure of which is
incorporated herein by reference.
BACKGROUND
[0002] 1. Field
[0003] The present invention relates to a control method of a
washing machine, and more particularly to a control method of a
washing machine in which a rinsing performance is reliably
guaranteed and a rinsing cycle is performed as many times as is
proper.
[0004] 2. Description of the Related Art
[0005] If a user inputs a desired washing course, a washing machine
washes laundry through processes of washing, rinsing, and
dehydrating in accordance with a predetermined washing course. A
designer determines and sets the number of times of rinsing
generally utilized with the respective washing courses when
designing a washing machine, and the rinsing of the laundry is
performed by the set times of the rinsing.
[0006] However, if the laundry is always rinsed a predetermined
number of times even though there are differences in quantity,
kind, and solubility of detergent added by the user, the rinsing
performance of the washing machine cannot be reliably guaranteed,
and water and electricity are frequently overused.
[0007] To solve the above-mentioned problem, Korean Unexamined
Patent Application Publication No. 2003-44491 discloses an
automatic rinsing control method of a washing machine of measuring
turbidity of rinsing water using a photo sensor, of additionally
performing the rinsing cycle when the measured turbidity is greater
than a predetermined degree, and of finishing the rinsing cycle
when the measured turbidity of the rinsing water is less than the
predetermined degree.
[0008] However, in the disclosed control method, when a foreign
substance is put between a light emitting unit and a light
receiving unit of the photo sensor, there is a high chance that a
malfunction will occur such that the turbidity of the rinsing water
appears to be greater than a predetermined degree, in spite of the
turbidity being less than the predetermined degree, and the rinsing
cycle is performed continuously.
[0009] Meanwhile, the user distrusts the rinsing performance of the
washing machine and sets an excessive number of times of rinsing by
extra times of the rinsing to the predetermined number of times.
However, when the rinsing cycle added by the user is performed even
though there is no necessity to perform the number of times of the
rinsing set by the user in order to rinse the laundry efficiently,
water and electric power are wasted, and it is a longer process to
wash the laundry. Thus, the user is inconvenienced.
SUMMARY
[0010] The present invention has been made in view of the
above-mentioned problems. An aspect of the invention provides a
control method of a washing machine that guarantees a reliable
rinsing performance of the washing machine and prevents undesired
energy from being consumed.
[0011] In accordance with one aspect, an embodiment of the present
invention provides a control method of a washing machine that
measures a turbidity of the rinsing water and determines whether a
rinsing cycle is finished, comprising: circulating the rinsing
water through a circulation passage by driving a circulation
device; measuring a magnitude of current flowing through the
rinsing water by supplying a voltage to electrodes installed on the
circulation passage; and comparing the detected magnitude (I2) with
a reference value (Ir) and determining whether the rinsing cycle is
finished based on the comparison result.
[0012] Generally, when the detected magnitude (I2) of the current
is equal to or less than the reference value (Ir), the rinsing
cycle is finished and when the detected magnitude (I2) of the
current is greater than the reference value (Ir), another rinsing
cycle is added and performed.
[0013] In an embodiment, control method of a washing machine
further comprises: circulating detergent water through the
circulation passage during a washing cycle performed prior to the
rinsing cycle; detecting the magnitude of the current flowing in
the detergent water by supplying a voltage to the electrodes; and
determining whether a quantity of detergent added by a user is
excessive by comparing the detected magnitude (I1) with a reference
value (Iw).
[0014] In this embodiment, when the detected magnitude (I1) is
equal to or greater than the reference value (Iw), information that
the excess detergent is being utilized is displayed on a display.
Moreover, when the detected magnitude (I1) is equal to or greater
than the reference value (Iw), the number of rinsing cycle times is
increased, and an elongated washing time is displayed on a display.
Thus, when the detected magnitude (I1) is equal to or greater than
the reference value (Iw), a quantity of the rinsing water to be
supplied at an initial rinsing cycle is re-set.
[0015] The electrodes are made of different materials, and the
control method further comprises changing polarities of the voltage
to be supplied to the electrodes for a predetermined time before
the rinsing cycle is finished.
[0016] Either of the electrodes comprises a silver electrode
containing silver, and the other comprises a titanium electrode
containing titanium. The titanium electrode is regarded as a
positive electrode when the voltage is supplied to the
electrodes.
[0017] Moreover, the control method further comprises: counting the
number of rinsing cycle times; and finishing the rinsing cycle
based on a result of comparing the counted number of times of a
rinsing cycle with a maximum number of times of a rinsing
cycle.
[0018] In accordance with another aspect, in an embodiment, the
present invention provides a control method of a washing machine
comprising: circulating detergent water collected in a tub through
a circulation passage during a washing cycle; supplying a voltage
to a pair of electrodes made of different materials and installed
on the circulation passage to determine whether a quantity of
detergent contained in the detergent water is excessive;
circulating rinsing water collected in the tub through the
circulation passage during a rinsing cycle; detecting a magnitude
of current flowing through the rinsing water by supplying the
voltage to the pair of electrodes; and comparing the detected
magnitude (I2) of current with a reference value (Ir) and finishing
the rinsing cycle when the detected magnitude (I2) is equal to or
less than the reference value (Ir).
[0019] In such an embodiment, the control method further comprises:
counting the number of rinsing cycle times; and finishing the
rinsing cycle even when the detected magnitude (I2) exceeds the
reference value (Ir) when the counted number of times of rinsing
cycle reaches the maximum number of times of rinsing cycle.
[0020] Either of the pair of electrodes comprises a silver
electrode containing silver, and the other comprises a titanium
electrode containing titanium.
[0021] The titanium electrode is regarded as a positive electrode
when the voltage is supplied to the pair of electrodes.
[0022] The voltage is supplied by regarding the silver electrode as
a positive electrode for a predetermined time before the rinsing
cycle is finished.
[0023] When it is determined that an excessive quantity of the
detergent is contained in the detergent water, information that the
excessive quantity of the detergent is contained is displayed on a
display, and a quantity of the rinsing water to be supplied at an
initial rinsing cycle is re-set.
[0024] Additional aspects and/or advantages of the invention will
be set forth in part in the description which follows and, in part,
will be obvious from the description, or may be learned by practice
of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] These and/or other aspects and advantages of the invention
will become apparent and more readily appreciated from the
following description of the embodiments, taken in conjunction with
the accompanying drawings in which:
[0026] FIG. 1 is a perspective view illustrating a washing machine
employing a control method according to an embodiment of the
present invention;
[0027] FIG. 2 is a schematic view partially illustrating the
washing machine in FIG. 1;
[0028] FIG. 3 is a block diagram illustrating the control of the
washing machine according to an embodiment of the present
invention; and
[0029] FIGS. 4A and 4B are flowcharts illustrating the control
method of a washing machine according to an embodiment of the
present invention.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0030] Reference will now be made in detail to the embodiments,
examples of which are illustrated in the accompanying drawings,
wherein like reference numerals refer to the like elements
throughout. The embodiments are described below to explain the
present invention by referring to the figures.
[0031] FIG. 1 is a perspective view illustrating a washing machine
employing a control method according to an embodiment of the
present invention, FIG. 2 is a schematic view partially
illustrating the washing machine in FIG. 1, and FIG. 3 is a block
diagram illustrating the control of the washing machine according
to an embodiment of the present invention.
[0032] As illustrated in FIGS. 1 to 3, a washing machine to which a
control method according to the present invention is applied
includes a drum type tub 11 installed in a main body 10 to
accommodate water (washing water or rinsing water), and a
cylindrical rotation drum 12 installed in the tub 11 to rotate.
Here, the terms `washing water` and `rinsing water` indicate waters
to be supplied to the tub 11 during a washing cycle and a rinsing
cycle.
[0033] A door 13 is installed in the front side of the main body 10
to open and close an opening through which laundry is put in or
taken out, and a control panel (not shown) is installed to control
operation of a drum type washing machine. The control panel (not
shown) is typically provided with various buttons and a jog dial
such that a user can control the operation of the washing machine,
and with a display 14 (See FIG. 3) to display an operational status
of the washing machine.
[0034] A detergent feeder 20 to feed detergent and a water supply
30 to supply water (washing water or rinsing water) are installed
in the upper side of the tub 11, and an exhaust device, including
an exhaust pipe 41 and an exhaust valve 42 that exhausts the water
from the tub 11, are installed in the lower side of the tub 11.
Moreover, a driving motor 15 (See FIG. 3, and not shown in FIGS. 1
and 2) to rotate the rotation drum 12 is installed in the rear
outer side of the tub 11 to perform the washing operation, the
rinsing operation, and the dehydrating operation.
[0035] The detergent feeder 20 has an inner space divided into a
plurality of spaces and is installed in the front side of the main
body 10 such that the user may easily add the detergent and rinse
into the respective spaces. The divided spaces include a spare
washing detergent container to accommodate the detergent, a main
washing detergent container to accommodate the detergent used in
main washing, and a rinse container to accommodate a rinse used in
rinsing.
[0036] The water supply 30 is connected to an external water
supplying hose, and includes a water supply valve 31 to control the
supply of water, a connecting pipe 32 to connect the water supply
valve 31 to the detergent feeder 20, and a water supply pipe 33 to
guide water passing through the detergent feeder 20 into the tub
11. This configuration is intended to manage the water that is
supplied to the tub 11 and passes through the detergent feeder 20
so that the detergent in the detergent feeder 20 can be fed into
the tub 11 together with the water.
[0037] The washing machine employing the control method of the
present invention includes a circulation device 50 to circulate the
water in the tub 11. The circulation device 50 includes a first
circulation passage 51 having an end of the circulation device 50
connected to the lower side of the tub 11, and the other end
connected to the exhaust valve 42, a second circulation passage 52
having an end connected to the exhaust valve 42 and the other end
connected to the upper side of the tub 11, and a circulation pump
53 installed in the second circulation passage 52.
[0038] The exhaust valve 42 which is connected to the exhaust pipe
41, the first circulation passage 51, and the second circulation
passage 52 is implemented by a three-way valve capable of switching
passages. When the first circulation passage 51 is communicated
with the exhaust pipe 41 by the exhaust valve 42, the water is
exhaust from the tub 11. When the circulation pump 52 is driven
into the state wherein the first circulation passage 51 is
communicated with the second circulation passage 52 by the exhaust
valve 42, the water collected in the lower side of the tub 11 is
circulated along the circulation passages 51 and 52 and is ejected
through the ejecting nozzle 54 in the upper side of the tub 11.
[0039] Moreover, the washing machine employing the control method
of the present invention includes an electrode device 60 having an
electrode device case 61, a pair of electrodes (a first electrode
62 and a second electrode 63) installed in the electrode device
case 61, and an electrode device power supply 64 (See FIG. 3) to
supply a DC voltage to the pair of electrodes 62 and 63. The
electrode device 60 serves as a sensor to measure turbidity of
detergent water (water+detergent) or the rinsing water during the
washing cycle or the rinsing cycle, and may be utilized to
pasteurize the laundry, the tub 11, or the rotation drum 12 during
the washing cycle or the rinsing cycle.
[0040] The pair of electrodes 62 and 63 of the electrode device 60
is installed on the circulation passage 52. In a case in which the
electrodes 62 and 63 are installed on the circulation passage 52,
since the electrodes 62 and 63 are submerged into the water only
when the water circulates through the circulation passage 52, the
electrodes 62 and 63 can be prevented from being contaminated, by
submerging the electrodes 62 and 63 into the water for a long time.
Moreover, when the electrodes 62 and 63 are installed on the
circulation passage 52, the electrodes 62 and 63 measure the
turbidity of the water so that the turbidity of the water can be
more precisely measured (since the electrodes measure turbidity of
only the water collected, surrounding the electrodes when the
electrodes are installed in a specific position in the tub, the
turbidity of the water cannot be precisely measured when the
detergent is not dissolved uniformly in the water.)
[0041] The pair of electrodes 62 and 63 of the electrode device 60
are made of different materials. For example, the first electrode
62 may be a silver electrode containing silver (Ag) and the second
electrode 63 may be a titanium electrode containing titanium (Ti).
The second electrode 63 may be coated with platinum or iridium for
the improvement of durability.
[0042] When the silver electrode is used as the first electrode 62,
that is, as a positive electrode, a voltage is supplied to generate
silver ions. Using a sterilizing power of the silver ions, the
rotation drum 12, the tub 11, and the laundry in the rotation drum
12 can be sterilized.
[0043] Moreover, the use of the titanium electrode as the second
electrode 63 is to prevent the electrodes 62 and 63 from being
ionized and consumed when the electrode device 60 is used as a
sensor during the washing cycle and the rinsing cycle. Titanium is
minimally oxidized even when the voltage is supplied to the
positive electrode, that is, the second titanium electrode, because
of a low ionization.
[0044] Moreover, the washing machine employing the control method
of the present invention, as illustrated in FIG. 3, includes a
signal input unit 71, a lever detector 72, a current detector 73,
and a controller 74.
[0045] The signal input unit 71 inputs operation information such
as the washing course and addition of the rinsing selected by the
user to the controller 74, and the level detector 72 detects the
level of water supplied into the tub 11. The current detector 73
detects the magnitude of current flowing between the pair of
electrodes 62 and 63 when the voltage is supplied to the pair of
electrodes 62 and 63 and transmits the detected result to the
controller 74.
[0046] The controller 74 is a microcomputer to control the washing
machine based on the operation information inputted from the signal
input unit 71, and stores washing time and the number of times of
rinsing, which are predetermined according to a load (weight of
laundry), in the selected washing course. The controller 74 also
stores a current value Iw as a reference value that is used to
determine whether excess detergent is added during the washing
cycle, and a current value Ir as a reference value that is used to
determine the turbidity of the rinsing water during the rinsing
cycle. Since the detergent serves as electrolyte when being
dissolved in water, the magnitude of the current detected when the
electrodes 62 and 63 are submerged into the detergent water or the
rinsing water is detected to find the quantity of the detergent
dissolved in the detergent water or the rinsing water.
[0047] The controller 74 determines the quantity of the detergent
added by the user or the quantity of the detergent remaining in the
rinsing water during the rinsing cycle based on the information
transmitted from the current detector 73, and changes conditions
(for example, the number of times of the rinsing) for the rinsing
cycle based on the determination. In other words, the controller 74
supplies a quantity of rinsing water that is greater than a
predetermined quantity of rinsing water at the initial rinsing
cycle to perform the rinsing cycle when the user adds an excessive
quantity of the detergent. Moreover, when the magnitude of the
current detected at the rinsing cycle is less than the reference
value Ir, the controller 74 determines that the rinsing is
sufficient, and finishes the rinsing cycle.
[0048] Hereinafter, the control method of the washing machine is
configured as described above with reference to FIGS. 3, 4A and 4B.
FIGS. 4A and 4B are flowcharts illustrating the control method of a
washing machine according to the embodiment of the present
invention.
[0049] When the laundry is put into the rotation drum 12, and the
user selects the operation information such as the washing course,
washing temperature, the number of times of rinsing, and the like,
the operation information selected by the user is inputted to the
controller 74 through the signal input unit 71.
[0050] Then, the controller 74 starts the washing based on the
operation information inputted from the signal input unit 71, and
first determines whether the operation is turned on (S100).
[0051] If the operation is turned on, the controller 74 detects the
quantity of a load (weight of the laundry) put into the rotation
drum 12 (S102) and sets the washing time a and the number of times
of rinsing b based on the detected quantity of a load (S104).
[0052] Continuously, the controller 74 opens the water supply valve
31 to add the detergent into the tub 11 together with the water
(specifically, the washing water) for the washing of the laundry
(S106).
[0053] After the supply of the detergent water (the washing
water+the detergent) into the tub 11, the controller 74 drives the
circulation pump 53 of the circulation device 50 to circulate the
detergent water through the circulation passages 51 and 52. Then,
the detergent water located in the lower side of the tub 11 flows
to the upper side of the tub 11 and is ejected into the rotation
drum 12 through the ejecting nozzle 54, so that the laundry gets
evenly wetted, and the detergent is uniformly dissolved in the
water (S108).
[0054] The controller 74 determines whether a predetermined time
has elapsed (S110), and supplies a voltage to the first and second
electrodes 62 and 63 installed on the circulation passage 52 during
the circulation of the detergent water when the predetermined time
has elapsed. At that time, voltage is supplied to the positive
electrode, that is, the second titanium electrode 63, and the
negative electrode, that is, the first silver electrode 62. Then,
the silver electrode, that is, the first electrode 62, can be
prevented from being consumed due to oxidation. When voltage is
supplied to the first and second electrodes 62 and 63, current
flows through the detergent water passing through the circulation
passage 52 while the current detector 73 detects the magnitude 11
of the current flowing between the two electrodes 62 and 63
(S112).
[0055] Then, the controller 74 determines whether the detected
magnitude I1 of the current is equal to or greater than the
reference value Iw (S14), and performs the washing cycle when the
detected magnitude I1 is less than the reference value Iw (S120).
In other words, the controller 74 performs the washing cycle in
which the detergent water (water+detergent) is mixed with the
laundry well due to the rotation of the rotation drum 12, and the
washing is carried out by frictional force between the rotation
drum 12 and the laundry and a force of falling laundry.
[0056] On the other hand, when the detected magnitude I1 of the
current is equal to or greater than the reference value Iw as a
result of the operation S114, the following operations are
performed, and the washing cycle is performed. The controller 74
changes the number of times of rinsing is performed during the
initial rinsing cycle and is to be performed later. In other words,
the controller 74 sets the number of times of rinsing again such
that the quantity of the rinsing water that is greater than the
initially set quantity of rinsing water b can be supplied (S116).
Moreover, when it is determined as described above, the controller
74 expects the washing time to be extended, adds a predetermined
time (for example, time for performing the rinsing cycle once more)
to the washing time a, and displays the added predetermined time on
the display 14. The controller 74 displays a message that excess
detergent has been added on the display 14 such that the user can
reset the washing time on the display (S118).
[0057] When the washing cycle is finished, the rinsing cycle is
started. When the initial rinsing cycle is started, the controller
74 opens the water supply valve 31 to supply as much as a
predetermined quantity of rinsing water to the tub 11. Since it was
determined that an excessive amount of detergent has been added at
the above-mentioned washing cycle, the rinsing water, as much as
the re-set quantity, is supplied when the quantity of the rinsing
water is set again at the initial rinsing cycle. On the other hand,
when it is determined that excess detergent has not been added, and
the washing cycle is performed as it is, as much rinsing water as
the initially set quantity of the rinsing water b is supplied
(S122).
[0058] When the rinsing water is supplied, the initial rinsing
cycle is performed, and the controller 74 counts that the rinsing
cycle has been performed once (S122 and S124).
[0059] When the initial rinsing cycle is finished, the next rinsing
cycle is performed, and the controller counts that the rinsing
cycle has been performed once more. As such, by counting of the
number n times of performing the rinsing cycles, every rinsing
cycle prevents water and electric power from being wasted by
restricting the number of the rinsing cycles to be performed. In
the rinsing cycle after the initial rinsing cycle, rinsing water
that constitutes as much as the initially set quantity b is
supplied (S128 and S130).
[0060] Before the present rinsing cycle is finished, the controller
74 drives the circulation pump 53 to circulate the rinsing water in
the tub 11 through the circulation passages 51 and 52, and supplies
the voltage to the first and second electrodes 62 and 63. In this
case, like the washing cycle, the voltage is supplied by regarding
the titanium electrode, which is, the second electrode 63, as a
positive electrode and the silver electrode, which is the first
electrode 62, as a negative electrode. Then, the current flows
through the rinsing water passing through the circulation passage
52, and the current detector 73 detects the magnitude I2 of the
current flowing between the two electrodes 62 and 63 (S132).
[0061] Continuously, the controller 74 determines whether the
detected magnitude I2 of the current is equal to or less than the
reference value Ir (S134).
[0062] When it is determined that the detected magnitude I2 of the
current is equal to or less than the reference value Ir, the
controller 74 perceives the present rinsing cycle to correspond to
a final rinsing cycle and changes polarities of the voltage to be
supplied to the first and second electrodes 62 and 63 by
controlling the electrode device power source 64 before the present
rinsing cycle is finished (S138). In other words, the controller 74
supplies the voltage by regarding the silver electrode, that is,
the first electrode 62, as a positive electrode and the titanium
electrode, that is, the second electrode 63, as a negative
electrode. Then, the oxidation is generated from the first
electrode 62 and silver ions are supplied to the rinsing water. The
silver ions are supplied into the rotation drum 12 together with
the circulating rinsing water to sterilize the laundry. As such,
when the polarities of the voltage supplied to the first and second
electrodes 62 and 63 are changed, the electrodes can be washed. In
other words, when the voltage is supplied by regarding the first
electrode 62 as a negative electrode and the second electrode 63 as
a positive electrode, positively charged contaminants are attached
to the first electrode 62 and negatively charged contaminants are
attached to the second electrode 63. If the polarities of the
voltage supplied to the two electrodes 62 and 63 are changed, the
contaminants are removed due to repulsive force.
[0063] Meanwhile, when the detected magnitude I2 of the current
exceeds the reference value Ir as a result of the determination at
operation S134, it is determined whether the counted number n of
the rinsings reaches a maximum permissible number N of times of
rinsing (S136). As a result of the comparison, when it is
determined that the counted number n of times of rinsing does not
reach the maximum number N of times of rinsing, the operation S128
is performed once more so that the rinsing cycle is performed once
more and the next operation is performed.
[0064] When it is determined that the counted number n of times of
rinsing has reached the maximum number N of times of rinsing as a
result of the comparison, the above-mentioned operation S138 is
performed so that the laundry is sterilized and the contaminants
are removed from the electrodes.
[0065] The controller 74 determines whether the rinsing time of the
final rinsing cycle has elapsed (S140), finally finishes the
rinsing cycle when the rinsing time has elapsed (S142), and
finishes the washing operation after performing the dehydrating
cycle (S144).
[0066] As described above, according to the present invention, the
degree of contamination of the rinsing water is monitored such that
the rinsing cycle is automatically finished at a time when the
rinsing of the laundry is finished. Thus, the rinsing performance
is reliably guaranteed, and the undesired waste of water and
electric power can be prevented.
[0067] Moreover, according to the present invention, information
that excess detergent has been added is noticed by the user when
the user adds the quantity of the detergent more than a desired
quantity so that the user can add a desired quantity of the
detergent in the future.
[0068] Further, in the present invention, the number of times of
the rinsing cycle is restricted so that the rinsing cycle can be
prevented from being continuously repeated even when the electrode
device malfunctions.
[0069] According to the present invention, turbidity measuring and
sterilization of the rinsing water can be performed while
simultaneously using the electrode device.
[0070] Moreover, according to the present invention, the
contaminant attached to the electrodes is automatically removed so
that a lifespan of the electrodes is elongated, and the operation
reliability of the electrode device can be guaranteed.
[0071] Although a few embodiments of the present invention have
been shown and described, it would be appreciated by those skilled
in the art that changes may be made in these embodiments without
departing from the principles and spirit of the invention, the
scope of which is defined in the claims and their equivalents.
* * * * *