WO2011148344A1

WO2011148344A1 - Household appliance with stand-by wake-up system

Info

Publication number: WO2011148344A1
Application number: PCT/IB2011/052317
Authority: WO
Inventors: Gianluca Viola; Simone Tordoni
Original assignee: Indesit Company S.P.A.
Priority date: 2010-05-27
Filing date: 2011-05-27
Publication date: 2011-12-01
Also published as: ITTO20100444A1; EP2577173B1; EP2577173A1

Abstract

The present invention relates to a household appliance comprising a door (3) adapted to provide access to an internal cavity (4) of the household appliance, and a standby switch (10) adapted to take a first standby position, in which it breaks the current flow on a power supply line in order to place the household appliance into standby mode, and a second position, in which the household appliance is operational. The household appliance further comprises a sensor (8) that detects a physical quantity associated with the opening of the door, and wake- up means (6,8,11) operating when the household appliance is in standby and adapted to bring said standby switch (10) into said second position when said sensor (8) detects said physical quantity.

Description

"HOUSEHOLD APPLIANCE WITH STAND-BY WAKE-UP SYSTEM"

DESCRIPTION

[TECHNICAL FIELD]

The present invention relates to the field of household appliances, and in particular to a household appliance according to the preamble of claim 1.

The invention also relates to methods for controlling household appliances, in particular with reference to energy consumption control and standby regulation.

[PRIOR ART]

The recent developments and lower costs of electronic components, along with the need of offering increasingly innovative products to customers, have led to the development of more and more sophisticated household appliances (e.g. ovens, washing machines, television sets, refrigerators, dishwashers).

Many household appliances on the market today utilise sensors which allow to detect the operating state of the appliance or some physical quantities useful or necessary for its operation. For instance, many ovens are fitted with a thermocouple which allows detecting the temperature inside the cooking cavity, so that the food cooking process can be controlled.

The increasing use of on-board electronics has led household appliances to use much energy even when they are not operational, i.e. when they are not carrying out their main function, e.g. cooking in the case of an oven.

Aiming at reducing this energy consumption, a standby state is known to be used wherein no power is supplied to a part of the on-board electronics, in particular sensors and video or luminous interfaces.

In known household appliances, the exit from the standby state is possible in response to a button, typically a power button, pressed by user.

This results in limited simplicity and speed of use of the household appliances.

[OBJECTS AND BRIEF DESCRIPTION OF THE INVENTION]

It is one object of the present invention to overcome some of the above-described drawbacks of the prior art.

In particular, it is one object of the present invention to improve the simplicity and speed of use of a household appliance without substantially increasing its energy consumption in standby mode. These and other objects of the present invention are achieved through a household appliance incorporating the features set out in the appended claims, which are intended as an integral part of the present description.

One idea at the basis of the present invention is to provide the household appliance with an automatic function that wakes it up from standby when it is detected that the door has been opened. The household appliance is equipped with a sensor capable of detecting a physical quantity that can be associated with the opening of the door, even when the appliance is in standby, and of automatically waking up the appliance.

This solution offers more simplicity and speed of use of the household appliance because the user is no longer required to find and press a given button in order to wake up the appliance from standby, since it is sufficient to open the door.

In a preferred embodiment, the household appliance is fitted with passive sensors (i.e. not requiring any electric supply), such as a button whose change of position indicates that the door is open or a switch whose electric contact closes when the door is opened, thus causing the household appliance to wake up. This solution offers the advantage that it allows the household appliance to be automatically woken up without increasing standby consumption. As an alternative, it is possible to use sensors employing active elements, such as proximity sensors, in order to detect a physical quantity associated with the opening of the door, which sensors must be kept powered when the oven is in standby mode. This solution, for example, offers the advantage of increased reliability in that it is no longer necessary to use a mechanical switch, at the cost of a very small increase in energy consumption in standby mode.

Further objects and advantages of the present invention will become more apparent from the following description and from the annexed drawings.

[BRIEF DESCRIPTION OF THE DRAWINGS]

Some preferred and advantageous embodiments will now be described by way of non- limiting example with reference to the annexed drawings, wherein:

Fig. 1 shows an oven according to the present invention.

Fig. 2 shows a functional block diagram of the oven of Fig. 1.

- Fig. 3 shows an embodiment of the block 12 of Fig. 2.

Fig. 4 shows an embodiment of the block 14 of Fig. 2. Fig. 5 shows a functional block diagram of the machine 1 which is alternative to the one of Fig. 2.

The drawings show different aspects and embodiments of the present invention and, where appropriate, similar structures, components, materials and/or elements in the various drawings are designated by the same reference numerals.

[DETAILED DESCRIPTION OF THE INVENTION]

Fig. 1 shows a front view of an electric oven 1 according to the present invention.

The oven 1 comprises a body 2 that encloses a cooking cavity 4, called muffle, which is accessible through an aperture 16 that can be closed with a door 3.

The foods are placed into the cooking cavity 4, arranged in suitable pans, through the aperture 16.

During the cooking process, one or more electric resistors 5 heat up the cooking cavity 4 to bring said cooking cavity to the temperature desired by the user. A fan 15 arranged on the rear side of the cavity improves the heat diffusion inside said cavity, thereby making the temperature more uniform. Cooking temperature and time can be set manually by the user through an electronic interface 7 comprising a display and a control panel (or a touch-screen display only). In one embodiment, through said interface the user can also choose among different cooking programs.

A control unit 6 of the oven 1 controls the resistors 5 and the fan 15 so as to execute the desired cooking program.

The control unit 6 comprises a microcontroller whose task is to control the operation of the oven. For this purpose, the control unit is connected to both the electronic interface 7 and a plurality of sensors (such as temperature and/or humidity sensors), so as to receive information which is useful for properly controlling the oven.

In one embodiment, the sensor 8 is a mechanical-contact passive sensor substantially consisting of a button, arranged on the oven body 2, which can take two positions: when the door is closed, the button is held in a first position in which it opens an electric switch; when the door is open, the button comes out of its seat in the oven body 2 and takes a second position in which it closes said electric switch. The state of this electric switch indicates whether the door 3 is open or closed. For example, when the electric switch is closed, it may ground an input of the microcontroller of the control unit 6, which will thus detect the opening of the door.

Another example of a passive sensor that may be used in the present invention comprises two metal plates: the first one is positioned on the inner wall of the door 3 (this plate is preferably a portion of the door wall) and is connected to a fixed voltage level (e.g. ground), whereas the second one is positioned on the body of the oven body 2 and is connected to an input of the microcontroller. When the door is opened, contact is lost between the two plates and, as a result, the microcontroller detects a voltage variation at the input connected to the second plate, said variation being due to the fact that the second plate is no longer connected to the fixed voltage level.

As an alternative or in addition to passive sensors, it is also conceivable to use, for detecting the opening of the door, other sensors of the active type, such as inductive, capacitive, magnetic or optical proximity sensors. These sensors require an electric supply, though their power consumption is very small, to generate a signal (typically a digital signal) that depends on whether the distance threshold between the door 3 and the oven body 2 has been exceeded or not.

In general, when the sensor 8 detects that the door 3 is open, then it changes state, thus allowing for the detection of an event which can be classified as "door open".

In the following example, which will be described with reference to Fig. 2, the sensor 8 is a mechanical-contact sensor consisting of a button, and is schematized as a switch 8 that closes when the door 3 is opened.

Fig. 2 illustrates a portion of interest of the circuit diagram of the oven 1. It is understood that the oven 1 also comprises other electric and electronic components (such as, for example, user interface and electric loads) not shown in the diagram of Fig. 2, but connected to or associated with elements of Fig. 1.

The oven 1 comprises a power supply 200 receiving power from an alternating power line 201, shown herein as phase L and neutral N (e.g. a 230V @ 50Hz or 110V @ 60Hz mains voltage), and outputs a 12V direct voltage Vdc. The number and values of the output voltages supplied by the power supply 200 are not to be considered as limiting for the purposes of the present invention.

The control unit 6 is powered by a direct voltage (e.g. 3.3V) obtained from 12V Vdc through a suitable voltage regulator 9. Downstream of the power supply 200 there is a standby switch 10 controlled by the control unit 6. The standby switch 10 may be an electromechanical switch (e.g. a relay) or an electronic switch (e.g. a MOS transistor).

When the oven 1 enters the standby state, the control unit 6 opens the standby switch 10 to stop the power supply to all devices powered by Vdc voltage taken downstream of the standby switch 10. At the same time, the control unit 6 operates some (electromechanical or electronic) switches to disconnect the machine's loads which would otherwise remain connected to the alternating power mains, e.g. the fans or the heating resistors.

Other standby solutions may be adopted as well, as shown hereafter with reference to Fig. 5. Referring back to the example of Fig. 2, a block 11 for detecting the change of state of the sensor 8 and a block 12 for detecting when the power button 13 is pressed by the user are connected to a logic block 14 which allows detecting one of the "door open" and "power button pressed" events. In this embodiment, the oven is fitted with a power button in order to allow the user to execute some functions without having to open the door to turn on the oven. For example, the user may want to program the oven; to do so, it is useful and advantageous that the oven can be woken up from standby without having to open the door. Of course, other alternatives are also conceivable wherein the oven is not equipped with a power button. For example, instead of the power button 13, the oven may feature a program selector, e.g. consisting of a knob with multiple positions corresponding to different cooking programs and an OFF position corresponding to the off state of the oven. In this embodiment, the block 12 detects whether the selector is in the OFF position or not, and varies its output accordingly. When the user selects a cooking program through the selector, the output of the block 12 changes state and the oven is woken up from standby.

Alternatively, the oven is woken up from standby whenever the state of the selector changes. This turns out to be particularly advantageous if the oven enters the standby mode at the end of a cooking program, i.e. without the user turning the selector to an OFF position.

Referring back to the example of Fig. 2, the output OUT 14 of the block 14 is received at the wakeup input 60 of the control unit 6. When the user presses the power button, or when the sensor 8 signals that the door is open, the output signal of the block 14 is set to an active level, thereby indicating the necessity of waking up the oven 1.

In response to the activation of said signal at the wake-up input 60, the control unit 6 closes the standby switch 10 so as to supply current again to those devices which receive no power in standby mode.

Fig. 3 shows an embodiment of the block 12 of Fig. 2; said block comprises a resistor Rl and the power button 13 connected in series. The resistor Rl is connected to power voltage, whereas the button is connected to ground.

When the user presses the power button 13, the output OUT 12 of the block 12, between the resistor Rl and the button 13, is grounded and therefore switches from the high logic level (taken in standby mode) to the low logic level (taken at power on).

In one embodiment, the block 11 is designed substantially like the block 12, with the sensor 8 performing the same function as the button 13. When the sensor detects that the door is open, it closes and brings the output OUT11 of the block 11 low.

The outputs OUT 11 and OUT 12 of the blocks 1 1 and 12 are connected to the input of the block 14.

Fig. 4 shows one embodiment of the block 14. In this embodiment, the inputs IN11 and IN 12, which receive the signals from the outputs OUT 11 and OUT 12 of the blocks 1 1 and 12, respectively, are connected to the output OUT 14 through a respective diode (Dl l and D12) with the anode connected to the output.

The output OUT 14 is hung to the power voltage through a resistor R2, and therefore it remains high as long as both the inputs INI and IN2 are high; in all other cases it is low. The output OUT 14 is connected to the wake-up input 60 of the control unit 6, which wakes up when a low signal is present at the input, indicating that at least one event (of the "power button pressed" and "door open" events) has been detected.

The output OUT 11 of the block 11, i.e. the signal that carries the information about the detection of the event associated with the change of state of the sensor 8, is also supplied to a second input 61 of the control unit 6.

The input 61 is read when the machine 1 is running and it is also necessary to check its operation during the execution of a cooking step.

The example of Fig. 5 shows a variant of the circuit diagram of Fig. 2, wherein the control unit 6 takes power downstream of the standby switch 10. In this embodiment, when the household appliance enters the standby mode, the control unit 6 cuts the power to itself as well, and therefore it can act upon the switch only to open it, not to close it. For this reason, the output of the block 14 is not sent to the control unit 6, which would not be able to activate itself; instead, it is used for controlling the standby switch 10. In this embodiment, pressing the button 13 or closing the sensor 8 will directly cause the standby switch 10 to close, thereby supplying current again to the whole appliance, which will then wake up.

It is apparent from the above that the oven 1 can wake up from the standby state both when the user presses the power button and automatically when the door is opened. This makes the oven simpler and quicker to use.

It is clear the many changes may be made to the above-described embodiments by a man skilled in the art wanting to design a household appliance with an automatic standby wake- up function, without however departing from the protection scope of the present invention as set out in the appended claims.

For example, the various circuit blocks may be combined and integrated differently to form new blocks performing the same functions.

The standby switch may be located in various points of the power line so as to adjust the standby function in different ways. For example, in one embodiment the standby switch may be arranged upstream of the power supply 200, so that it can directly act upon an input phase of the latter (e.g. phase L of Fig. 2); in standby mode the power supply 200 will thus be completely disconnected, resulting in lower standby consumptions.

In this embodiment, the standby switch is preferably controlled directly by the switch 13 or by the sensor 8 that detects the opening of the door.

The sensor that remains operational in standby mode may be of various types; the example of the button is in fact a preferred but non-limiting example of the present invention.

The invention, described herein with reference to an oven, is also applicable to other types of household appliances fitted with doors, e.g. a dishwasher or a washing machine or a refrigerator. In the case of a refrigerator, the standby mode will of course be limited to those electronic portions that can be turned off without compromising the operation of the appliance, e.g. a display.

Claims

1. A household appliance comprising

a door (3) adapted to provide access to an internal cavity (4) of the household appliance, a standby switch (10) adapted to take a first standby position, in which it breaks the current flow on a power supply line in order to place the household appliance into standby mode, and a second position, in which the household appliance is operational,

a sensor (8) adapted to detect when the door (3) is open,

characterized in that it comprises wake-up means (6,8,11) operating when the household appliance is in standby and adapted to bring said standby switch (10) into said second position when said sensor (8) detects that the door is open.

2. A household appliance according to claim 1 , further comprising a control unit (6) adapted to bring said standby switch (10) into said first position.

3. A household appliance according to claim 2, wherein said wake-up means comprise said control unit (6), said control unit (6) being operationally connected to said sensor (8) to receive a signal generated by said sensor (8) about the opening of the door, said control unit (6) being supplied by said power supply line when the household appliance is in standby and being adapted to switch said standby switch (10) from said first position to said second position.

4. A household appliance according to claim 2, wherein said control unit (6) is not powered in standby mode, wherein said sensor (8) is adapted to generate a wake-up signal when it detects that the door is open, and wherein said standby switch (10) is operationally connected to said sensor (8) and is adapted to switch itself from said first position to said second position when it receives said wake-up signal.

5. A household appliance according to any one of the preceding claims, further comprising a power supply (200) adapted to receive at its input a mains alternating voltage and to output at least one direct voltage to be supplied to electric components of said household appliance, wherein said standby switch (10) is arranged upstream of said power supply (200).

6. A household appliance according to any one of the preceding claims, comprising a cooking program selector adapted to take a plurality of working positions and operationally connected to said wake-up means, said wake-up means being adapted to bring said standby switch (10) into said second position when the position of said selector is changed.

7. A household appliance according to any one of the preceding claims, wherein said sensor (8) is an electric contact sensor.

8. A household appliance according to any one of the preceding claims, wherein said sensor is a proximity sensor.

9. A household appliance according to any one of the preceding claims, wherein said household appliance is a dishwasher or an oven or a washing machine or a refrigerator.

10. A method for controlling a household appliance, wherein said household appliance comprises a door and said household appliance is woken up from a standby state when it is detected that the door is open by a sensor being operational in standby.