Description A WASHER/DRYER

[1] The present invention relates to a washer/dryer wherein the laundry type or weight emplaced inside is identified to cany out the washing or the drying process accordingly.

[2] In washer/dryers, the type and weight of the laundry emplaced in the drum are factors that directly affect the washing performance efficiency. Therefore foreknowledge of these values and carrying out processes accordingly enhance the washing performance. The most effective washing and drying processes and savings in energy consumption are achieved by way of determining the amount of the water according to the type and weight of the laundry emplaced in the drum.

[3] In the state of the art European Patent no. EP0480387 in a laundry machine the type of fabrics to be laundered or dried is identified by waiting for the accumulation of electrostatic charges produced during the friction of the laundry with the drum and/or with other laundry in the drum to reach a predetermined voltage value, and the time period in which the accumulated electrostatic charge is discharged depends on the type of fabrics to be laundered or dried. In this document the voltage value that has to be reached is predetermined. Instead of the voltage value, the time period for charging up to a predetermined voltage value and the discharging duration (charge, discharge frequency) is used to identify the type of the laundry emplaced in the drum.

[4] The object of the present invention is the realization of a washer/dryer wherein the type or the weight of the laundry emplaced in the drum is identified correctly.

[5] The washer/dryer realized in order to fulfill the objectives of the present invention, described in the first claim and the respective claims thereof, comprises an electrostatic charge sensing device for measuring the electrostatic charges produced as a result of the friction due to the contact of the laundry with each other and/or the laundry with the drum.

[6] According to every weight, how much electrostatic charge accumulates on the drum for each type of laundry and the corresponding voltage value that will result are predetermined. If the weight of the laundry is known, then the type of the laundry emplaced in the drum can be easily identified by measuring the voltage value produced by the electrostatic charges accumulated on the drum. Similarly when the type of the laundry is known, then the weight of the laundry emplaced in the drum can be identified by measuring the voltage value produced by the electrostatic charges accumulated on the drum.

[7] In identifying the type or weight of the laundry, no processes are performed on the voltage values produced by the electrostatic charges accumulated on the drum and only

the voltage values measured directly are used. Since no other evaluation is performed on the voltage signal, the electrostatic charge sensing device contains simpler and a lesser number of circuit elements.

[8] The voltage value produced due to the accumulation of electrostatic charge on the drum is compared to the pre-measured voltage values on the drum according to the type and weight of the laundry and the coinciding or the closest value belonging to the laundry type or weight are determined as the laundry type or weight emplaced in the drum. After this process, the washing algorithms suitable to the laundry type or weight are implemented. In this case, there is no need for the user to carry out especially the laundry type selection process.

[9] Accordingly, the errors that may arise from the incorrect evaluation of the laundry type by the user are prevented. Furthermore there is no longer a need for the laundry type selection buttons on the control panel, providing flexibility in the design of the control panel also reducing costs by the elimination of this button or buttons.

[10] In the washer/dryer of the present invention, the drum is rotated at a certain revolution for a certain time period with dry laundry inside before proceeding with the washing and/or the drying process. Accordingly the friction of the laundry is increased by contact with one another and with the drum and the electrostatic charge accumulation on the drum is maintained.

[11] In the washer/dryer of the present invention, the tub is produced of a non- conductive material like plastics or the like, the drum is produced of a conductive material like steel or the like. Accordingly, the grounding of the accumulated charges on the drum by connecting to earth via the tub is prevented; grounding is achieved in a controlled way by connecting to earth via the isolated circuit that measures the electrostatic charge on the drum.

[12] By way of the present invention, the type or weight of the dry laundry emplaced in particularly the washing machine or the dryer is identified without utilizing complex algorithms, enhancing the washing and/or drying performance values like the most suitable energy and water consumption. The washing or the drying process is arranged to be carried out without any intervention of the user by identifying the other unknown when either one of the type or the weight of the laundry is known and selecting the most suitable washing or drying program according to the identified weight or type.

[13] The washer/dryer realized in order to fulfill the objectives of the present invention is illustrated in the attached figures, where:

[14] Figure 1 - is the schematic view of a washer/dryer.

[15] Figure 2 - is the schematic view of an electrostatic charge sensing device.

[16] The elements shown in figures are numbered as follows:

[17] 1. Washer/dryer

[18] 2. Tub

[19] 3. Drum

[20] 4. Electrostatic charge sensing device

[21] 5. Control unit

[22] 6. Insulating circuit

[23] 7. Buffer circuit

[24] 8. Filter circuit

[25] 9. Amplifying circuit

[26] 10. Automatic discharge circuit

[27] The washer/dryer (1) of the present invention comprises a tub (2) made of an nonconducting material, a drum (3) made of conductive material, into which laundry to be washed is emplaced, an electrostatic charge sensing device (4) that measures the voltage (V measured) produced by the electrostatic charges accumulated on the drum (3) and a control unit (5) wherein the electrostatic charge voltage values (V stored) on the drum are stored, predetermined by the producer, depending on the type and weight of the dry laundry emplaced in the drum (3) and comparing these values (V stored) to the values (V measured) received from the electrostatic charge sensing device (4) providing to identify the type or the weight of the laundry emplaced in the drum (3) when either one of them is known and to execute the washing or the drying process accordingly (Figure 1).

[28] When the washing or the drying process is desired to be executed according to the type of the laundry, the weight of the laundry emplaced in the drum (3) is either entered automatically or by the user in the control unit (5). The voltage value (V measured) measured by the electrostatic charge sensing device (4) is compared to the electrostatic charge voltage values (V stored), predetermined by the producer according to weight and type, and the electrostatic voltage value (V stored) that is closest or coinciding with the measured voltage value (V measured) is selected. At the weight entered in the control unit (5), the laundry type corresponding to this selected voltage value (V stored) which is prerecorded in the control unit (5) is determined as the type of laundry emplaced in the drum (3) and the washing or the drying process is initiated accordingly.

[29] When the washing or the drying process is desired to be executed according to the weight of the laundry, the type of the laundry emplaced in the drum (3) is either entered automatically or by the user in the control unit (5). The voltage value (V measured) measured by the electrostatic charge sensing device (4) is compared to the electrostatic charge voltage values (V stored) predetermined by the producer according to weight and type, and the electrostatic voltage value (V stored) that is closest or coinciding with the measured voltage value (V measured) is selected . The laundry

weight corresponding to the selected voltage value (V stored) of the laundry type entered in the control unit (5) and stored previously in the control unit (5), is determined as the weight of laundry emplaced in the drum (3) and the washing or the drying process is initiated accordingly.

[30] The electrostatic charge sensing device (4) comprises an insulating circuit (7), a filter circuit (8), an amplifying circuit (9) and an automatic discharge circuit (10) (Figure 2).

[31] The insulating circuit (6) is utilized for providing the isolated accumulation of electrostatic charges on the drum (3) and for providing safety. This circuit (6) comprises an isolation transformer. The buffer circuit (7) is situated after the insulating circuit (6) and is put for preventing the disruption of electric signals caused by the accumulated charges on the drum (3). The filter circuit (8) is utilized for preventing the oscillation and noise formed in the electric signal. The filter circuit (8) is preferably an active low- pass filter circuit (8). The amplifying circuit (9) provides amplification of the voltage value caused by the accumulated charges on the drum (3) by a certain percentage. Accordingly, the electric signal is amplified to a value that can be sensed by the control unit (5). Afterwards this electric signal has to be rectified in order to convert it into a format that can be detected by the control unit (5). The control unit (5) is enabled to evaluate this signal by using a suitable rectifier deriving DC levels. The automatic discharge circuit (10) provides to discharge the electrostatic charge on the drum (3) before taking measurements. Consequently the electrostatic charge loading process can always start from the same value.

[32] In an embodiment of the present invention, when the washing or the drying process is desired to be executed according to the type of the laundry emplaced in the drum (3), the weight of the laundry emplaced in the drum (3) is entered in the control unit (5) automatically or by the user. The drum (3) is rotated around its axis at a certain revolution rate for a certain time period before starting the washing or the drying process. Accordingly, the electrostatic charges that are produced by the friction of the laundry with each other and/or the inner surface of the drum (3) are accumulated on the drum (3) and an electrostatic charge voltage value is formed. This electrostatic charge voltage value is measured by the electrostatic charge sensing device (4). The measured electrostatic charge voltage value (V measured) is compared to the predetermined voltage values (V stored) stored in the control unit (5) determined according to the type and weight of the laundry emplaced in the drum (3). The type of laundry that causes the measured electrostatic charge voltage value (V measured) to coincide with or be closest to the voltage value (V stored), is determined as the type of laundry emplaced in the drum (3). After this process is completed, the washing or the drying process most suitable to the identified laundry type is resumed.

[33] Similarly in another embodiment of the present invention, when the washing or the drying process is desired to be executed according to the weight of the laundry emplaced in the drum (3), the type of the laundry emplaced in the drum (3) is entered in the control unit (5) automatically or by the user. The drum (3) is rotated around its axis at a certain revolution rate for a certain time period before starting the washing or the drying process. Accordingly, the electrostatic charges that are produced by the friction of the laundry with each other and/or inner surface of the drum (3) are accumulated on the drum (3) and an electrostatic charge voltage value is formed. This electrostatic charge voltage value is measured by the electrostatic charge sensing device (4). The measured electrostatic charge voltage value (V measured) is compared to the predetermined voltage values (V stored) stored in the control unit (5) predetermined according to the type and weight of the laundry emplaced in the drum (3). The weight of the laundry that causes the measured electrostatic charge voltage value (V measured) to coincide with or be closest to the voltage value (V stored), is determined as the weight of laundry emplaced in the drum (3). After this process is completed, the washing or drying process most suitable to the identified laundry weight is carried on.

[34] Accordingly, when either one of the weight or the type of laundry is known, the unknown value can be easily found by using the voltage values (V stored) prerecorded in the control unit (5) which correspond to the measured electrostatic voltage value (V measured).

[35] For example, if the electrostatic voltage value (V measured) measured on the drum (3) for 2 kg. of laundry is 45 mV., then it is decided that the laundry type emplaced in the drum (3) is woolen. When mixed laundry is emplaced in the drum (3), whichever laundry type is closer to the voltage value measured according to weight, then the washing or the drying algorithms according to that type of laundry is implemented. Similarly, if we know that the laundry emplaced in the drum (3) is synthetic and if the electrostatic voltage value (V measured) measured on the drum (3) is 60 mV, then the weight of the laundry emplaced in the drum (3) can be specified as 4 kg.

[36]

[37] The type or the weight of laundry can be determined by the user or automatically by various methods. In an embodiment of the present invention, the washer/dryer (1) comprises a weight sensor that detects the weight of the laundry emplaced in the drum (3).

[38] By way of the present invention, the user is relieved especially from the burden of selecting the laundry type, likewise the errors that may be made in selections which can directly affect the washing performance are minimized, enhancing washing performance.