Washing machine having deodorizing means and control method thereof

The present invention relates to a washing machine having a drum rotatably mounted within a tub, and a control method thereof.

Washing machines are apparatuses for removing contaminants from clothes using friction between water and the clothes, and are divided into various types based on their washing methods. A drum type washing machine is widely used and includes a cylindrical tub to contain wash water, a cylindrical drum rotatably mounted within the tub, a motor to rotate the drum, a water supply unit to supply water to the drum, and a drying unit to dry laundry placed in the drum.

When washing instructions are inputted to the conventional drum type washing machine, a microcomputer supplies wash water to the drum using the water supply unit, performs washing, rinsing and spin-drying operations, and supplies hot air to the drum using the drying unit so that clothes placed in the drum are dried.

However, conventional drum type washing machines do not include any deodorising means. Therefore, when particles of offensive odour, such as the smell of tobacco or food are attached to clothes, conventional drum type washing machines merely perform washing/rinsing/spin-drying/drying operations to attempt to remove the odour from the clothes. Accordingly, conventional drum type washing machines suffer the drawback that they increase wear and tear of the clothes with the increased frequency of washing operations and thus require an unnecessarily excessive consumption of electric power.

It is therefore an object of the invention to provide a washing machine having deodorising means which remove offensive odours from objects to be deodorised and, a control method thereof.

The washing machine of the present invention is characterised by a deodorising means operable to perform a deodorising process independently of a washing process to deodorise laundry placed in the drum, and the control method of the invention is characterised by the step of performing said deodorising process.

In a preferred embodiment of the invention, the deodorising means comprises an operating water-producing means to produce a supply of operating water, and the deodorising means preferably comprises a steam generator fluidly coupled to the operating water-producing means to generate steam from the operating water.

The steam generator advantageously comprises a heating tank having a heating element therein and a steam supply pipe fluidly coupled between the heating tank and the tub to convey steam from the steam generator to the tub.

Conveniently, the steam generator further comprises a water level sensor disposed in the heating tank to monitor a level of operating water therein, and may further comprise a temperature sensor disposed in the heating tank to monitor the temperature of operating water therein, and may also comprise a pressure sensor disposed in the heating tank to monitor a pressure of the steam therein.

In a preferred embodiment, a connection pipe fluidly connects the operating water-producing means to the steam generator, and a valve is disposed in the connection pipe to control the flow of operating water into the steam generator.

A control unit is preferably provided to control the operation of the deodorising means, and preferably includes an input means to input deodorising instructions therethrough.

The operating water-producing means is preferably a silver solution-producing unit and the operating water is silver solution, or alternatively, the operating water producing-means may be an electrolysis apparatus and the operating water may therefore be electrolysed water.

A water supply pipe is preferably connected to the operational water-producing unit to supply water thereto, a water supply valve may be installed in the water supply pipe to control a flow of water therethrough.

A preferred embodiment of the invention further comprises a drying unit for supplying hot air to the drum, and the drying unit preferably comprises an air blast fan to supply air to the tub, a discharge duct connecting an outlet of the air blast fan to an opening of the tub to discharge air supplied from the air blast fan into the tub, a condensing duct connecting an air outlet installed through a lower part of a rear portion of the tub to an inlet of the air blast fan to condense water, and a heater installed in the discharge duct to heat the air supplied from the air blast fan

Preferred embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which: <ul id="ul0001" list-style="none" compact="compact"><li>Figure 1 is a perspective view of a drum type washing machine in accordance with a first embodiment of the present invention;</li><li>Figure 2 is a cross sectional view of a steam generating unit of the drum type washing machine shown in Figure 1;</li><li>Figure 3 is a block diagram illustrating the drum type washing machine shown in Figure 1;</li><li>Figure 4 is a flow chart illustrating an operation of the drum type washing machine shown in Figures 1-3;</li><li>Figure 5 is a perspective view of a drum type washing machine in accordance with a second embodiment of the present invention;</li><li>Figure 6 is a block diagram illustrating the drum type washing machine shown in Figure 5; and</li><li>Figure 7 is a flow chart illustrating an operation of the drum type washing machine shown in Figures 5 and 6.</li></ul>

Referring now to Figure 1, a drum type washing machine is shown in accordance with a first embodiment of the present invention, having a main body 10, a cylindrical tub 11 mounted within the main body 10 to contain wash water therein and a cylindrical drum 12 rotatably mounted in the tub 11 and provided with a plurality of drain holes formed through a wall thereof. A driving motor 12 is provided to rotate the drum 12 in a clockwise or anti-clockwise direction and a door 14 is hingedly mounted to the main body 10 to open or close an opening therein to allow laundry to be placed in or taken out of the washing machine. An input unit 15 is disposed on an upper part of a front surface of the main body 10 and includes a plurality of keys, one of said keys comprising a deodorising button 16 to allow a user to input deodorising operation instructions.

The drum type washing machine further comprises a silver solution-producing unit 20 to produce a silver solution to deodorise the laundry placed in the drum 12, a water supply unit 30 to supply water to the silver solution producing unit 20, a steam generating unit 40 to generate steam by heating the silver solution, a drying unit 50 to dry laundry, and a drain unit 60 to forcibly discharge wash water from the tub 11.

Various types of silver solution-producing units are known in the state of the art. Generally, silver solution-producing devices comprise two silver bars which are soaked in water and an electric current is supplied between the two silver bars, thereby producing a silver solution. Such a silver solution-producing unit is disclosed in detail in Korean Utility Model No. 2001-001169 and Korean Patent No. 2004-0004267.

The water supply unit 30 comprises a first water supply pipe 31 to supply water to the silver solution producing unit 20, a first water supply valve 32 to control the quantity of water flowing in the first water supply pipe 31, a second water supply pipe 34 to supply water to a detergent dissolving unit 33, a second water supply valve 35 to control the quantity of water flowing in the second water supply pipe 34, and a third water supply pipe 36 to supply water containing the dissolved detergent to the tub 11.

The drying unit 50 comprises an air blast fan 51 mounted to an upper part of the tub 11, a discharge duct 52 interposed between an outlet of the air blast fan 51 and an opening of the tub 11, a condensing duct 53 interposed between an air outlet at a lower part of a rear portion of the tub 11 and an inlet of the air blast fan 51, and a heater 54 installed in the discharge duct 53.

The drain unit 60 is installed in the lower part of the main body 10 and comprises a drain pipe 61 and a drain pump 62.

Referring now to Figure 2, the steam generating unit 40 is shown in more detail and comprises a heating tank 41 in the form of a sealed container to contain a predetermined quantity of the silver solution, and a heater 42 to heat the silver solution in the heating tank 41, to thereby generate steam. The steam generating unit 40 further comprises a water level sensor 43 to control a water level in the heating tank 41, a temperature sensor 44 to control a temperature in the heating tank 41, and a pressure sensor 45 to control a pressure in the heating tank 41. The water level sensor 43, the temperature sensor 44 and the pressure 45 are all mounted on an upper part of the heating tank 41.

A connection pipe 46 is connected to a side surface of the heating tank 41 to supply the silver solution produced by the silver solution-producing unit 20 to the heating tank 41 and a steam supply unit 70 is connected to another side surface of the heating tank 41 to supply steam to the tub 11. A connection valve 47 is installed in the connection pipe 46 to control the quantity of the silver solution flowing through the connection pipe 46.

The steam supply unit 70 comprises a steam supply pipe 71 to convey steam from an inside of the heating tank 41 to an inside of the tub 11, a steam supply valve 72 installed in the steam supply pipe 71 to control the quantity of the supplied steam and a steam diffusion pump (not shown) installed at an outlet of the steam supply pipe 71 to diffuse the ejection of the steam into the tub 11. The steam supply pipe 71 extends into the heating tank 41 and is then bent upwardly so that an inlet of the steam supply pipe 71 is positioned in the upper part of the heating tank 41 to ensure that only the steam in the heating tank 41 is able to flow therethrough.

Figure 3 is a schematic block diagram of the drum type washing machine of an embodiment of the present invention comprising a drum motor-driving unit 81 to drive a drum motor 82 for rotating the drum 12, a fan motor-driving unit 83 to rotate an air blast fan motor 84 to rotate the air blast fan 51 to forcibly blow air to the drum 12, a steam supply valve-driving unit 85 to operate the steam supply valve 72, a connection valve-driving unit 86 to operate the connection valve 47, a heater-driving unit 87 to operate the heater 54, and a microcomputer 80 to control the above components.

An operation of the drum type washing machine shown in Figures 1-3 will now be described with reference to Figure 4. In operation 90, the microcomputer 80 determines whether deodorising instructions have been inputted by a user. The deodorising instructions are inputted to the washing machine by a user pressing the deodorising button 16 on the input unit 15 after clothes having an offensive odour have been loaded into the drum 12 to be deodorised.

If it is determined in operation 90 that deodorising instructions have not been inputted to the washing machine, the microcomputer 80 terminates a corresponding cycle. If it is determined that deodorising instructions have been inputted to the washing machine, the microcomputer 80 performs a deodorising mode, beginning with operation 92. The deodorising mode in this embodiment of the present invention is performed independently of a washing process. However, the deodorising mode may be performed continuously after the washing process, or may be performed without the washing process. For example when the user presses both a washing button (not shown) and the deodorising button 16, the deodorising operation is performed after washing/rinsing/spin-drying/drying operations are performed. On the other hand, when the user presses only the deodorising button 16, only the deodorising operation is performed without washing/rinsing/spin-drying/drying operations.

In order to commence performing the deodorising mode in operation 92, the microcomputer 80 opens the first water supply valve 32 to supply water to the silver solution producing unit 20, and when a water level in the silver solution producing unit 20 exceeds a reference water level, closes the first water supply valve 32. A voltage is then applied to the silver solution producing unit 20 for a first predetermined time to produce a silver solution. At this time, the connection valve 47 is closed so that the silver solution is not supplied to the steam generating unit 40 until the silver solution reaches a designated concentration. The first predetermined time is set in consideration of a time taken for the silver solution producing unit 20 to produce silver solution having the designated concentration.

After the first predetermined time has elapsed, the microcomputer 80 opens the connection valve 47 to supply the silver solution to the steam generating unit 40. The microcomputer 80 senses a water level in the steam generating unit 40 as the silver solution is supplied thereto and when the level of the silver solution exceeds a reference level, the microcomputer 80 closes the connection valve 47. At this time, the steam supply valve 72 is held in its closed state.

In operation 94, after the supply of the silver solution is completed, the microcomputer 80 operates the heater 54 to heat the silver solution and the heated silver solution is gradually vaporised into steam. Operation 96 is then performed wherein when the pressure generated by the steam in the steam generating unit 40, sensed by the pressure sensor 45, reaches a preset steam supply pressure, the microcomputer 80 opens the steam supply valve 72 for a second predetermined time to supply the steam to the tub 11. The steam which is supplied to the tub 11 permeates the clothes in the drum 12 and adheres to any particles of offensive odour on the clothes (for example the smell of tobacco, food, etc.). The steam then deodorises the clothes by decomposition of the particles of odour using silver (Ag), and the various impurities of the clothes are thereby sterilised by the silver (Ag).

The drum 12 may be rotated as the steam is supplied to the tub 11 so that the silver is more efficiently dispersed through the clothes and more easily bonds to the particles of odour. The value of the second predetermined time may be chosen as the optimum value as determined by experiments.

After operation 96, the process moves to operation 98, where the microcomputer 80 operates the heater 54 and drives the air blast fan 51 for a third predetermined time so that air is discharged from the air blast fan 51 and is heated by the heater 54 and is then supplied to the inside of the tub 11 through the discharge duct 52. The hot air vaporises moisture remaining in the clothes into steam, and the steam is conveyed to the condensing duct 53 by the hot air, condensed by the condensing duct 53, and is then discharged to the outside of the drum type washing machine. The hot air also conveys the particles of odour that have not been decomposed by the silver and these particles of odour are condensed with the steam by the condensing duct 53 and discharged to the outside of the drum type washing machine. Thereby, it is possible to remove offensive odour from clothes without an additional washing process.

Figures 5 and 6 illustrate a drum type washing machine in accordance with another embodiment of the present invention. Components common to both embodiments are designated with the same reference numerals. The drum type washing machine in this second embodiment differs from the drum type washing machine in the first embodiment in that electrolysed water is used as the operational water instead of a silver solution. In this second embodiment, acid water is generated by an electrolysis apparatus 100 (see Figure 5) and is supplied to the steam generating unit 40. The acid water (electrolysed water) has deodorising and sterilising effects similar to the silver solution, and such an electrolysis apparatus 100 is disclosed in detail in Korean Patent No. 2003-0060302 and Korean Utility Model Publication No. 20-0296928.

Figure 6 is a schematic block diagram of the drum type washing machine of the second embodiment of the invention and Figure 7 is a flow chart illustrating an operation of the drum type washing machine shown in Figures 5 and 6. The operation of the drum type washing machine in accordance with the second embodiment shown in Figure 7 is similar to that of the drum type washing machine of the first embodiment shown in Figure 4 except that in the second embodiment, acid water instead of the silver solution is supplied to the steam generating unit 40. Thus, in Figure 7, operations 110,114,116 and 118 correspond respectively to operations 90,94,96 and 98 shown in Figure 4. However, operation 112 differs from operation 92 shown in Figure 4 in that electrolysed water is produced instead of silver solution.

As is apparent from the above description, the present invention provides a washing machine having deodorising means to deodorise an object or clothing using operational water, and a control method thereof.

Further, the washing machine of the present invention and the control method thereof provide an advantage of simply and rapidly performing a deodorising operation independent of performing a washing process.

Although two embodiments of the invention have been shown and described, it will be appreciated by those skilled in the art that changes may be made to these embodiments without departing from the principle of the invention, the scope of which is defined in the claims hereafter.