Refrigerator and diagnostic system for the same

Provided are a refrigerator and a diagnostic system for the same. The refrigerator includes a selection unit, a control unit, a modulator, and a sound output unit. The selection unit receives a diagnosis performance command. The control unit generates a control signal including product information when the selection unit receives the diagnosis performance command. The modulator generates a frequency signal according to the control signal generated by the control unit. The sound output unit outputs a sound including the product information according to the frequency signal generated by the modulating unit.

TECHNICAL FIELD

The present invention relates to a refrigerator, and more particularly, to a refrigerator that outputs product information as a certain sound to facilitate state check and after-sale service of the refrigerator.

BACKGROUND ART

While operating, a refrigerator stores values set for its operation, information generated during its operation, failure information, and so forth. Particularly, a refrigerator may output a certain alarm signal when it fails, so that a user recognizes the state of the refrigerator. Such a refrigerator does not inform only operation completion or failure occurrence, but also output specific failure information by means of output devices such as displays and lamps.

When a refrigerator fails, a user may call upon a service center for an advice or a visit of a service technician as part of after-sale service.

In this case, since a refrigerator usually outputs simple failure information or code values unfamiliar to a user, it is difficult for the user to deal with the failure of the refrigerator and deliver the state of the refrigerator to the service center even when the user is connected to the service center. Accordingly, when a service technician visits a user's home, much time and cost may be spent for repair because the service technician has not been exactly informed of the state of the refrigerator in advance. For example, if components necessary for the repair of the refrigerator are not prepared in advance, the service technician has to revisit the user's home. This causes a waste of time.

Accordingly, a method for exactly delivering failure information of a refrigerator to a service center without explaining in detail to the service center is required.

DISCLOSURE OF INVENTION

Technical Problem

Thus, an object of the present invention is to provide a refrigerator that outputs product information as a certain sound to facilitate exact diagnosis of the refrigerator.

Solution To Problem

According to an aspect of the present invention, there is provided a refrigerator including: a selection unit receiving a diagnosis performance command; a control unit generating a control signal comprising product information when the selection unit receives the diagnosis performance command; a modulator generating a frequency signal according to the control signal generated by the control unit; and a sound output unit outputting a sound comprising the product information according to the frequency signal generated by the modulating unit.

According to another aspect of the present invention, there is provided a refrigerator diagnostic system including: a refrigerator outputting a sound comprising product information; a terminal receiving the sound outputted from the refrigerator by the medium of air, and transmitting the received sound through a communication network; and a diagnostic server receiving the sound transmitted from the terminal and extracting the product information from the received sound to perform a diagnosis of the refrigerator.

Advantageous Effects of Invention

A refrigerator according to an embodiment of the present invention has an advantage in that a user can take appropriate actions to repair the refrigerator without explaining in detail the operation state of the refrigerator to a service center because the refrigerator can output product information as a sound and perform failure diagnosis based on the outputted sound.

Also, a refrigerator according to an embodiment of the present invention has an effect of improving esthetic feeling and usability upon entrance into failure diagnosis of the refrigerator by including a sound output unit for outputting a sound including production information in a hinge unit that is coupled to a door of the refrigerator.

Also, a refrigerator according to an embodiment of the present invention has an effect of improving overall esthetic feeling of the refrigerator by including a sound output unit for outputting a signal sound including product information in a hinge unit of a refrigerator door to cover the sound output unit with the door when the door is closed.

Also, a refrigerator according to an embodiment of the present invention has an effect of enabling detail data transmission necessary for diagnosis because it can shorten the time taken to output a sound as the length of the sound including product information is reduced, reduce a data transmission time and a transmission data size according to the transmission of the sound, and transmit much more data for a certain time, by converting the product information into a control signal using a plurality of frequency signals.

Also, a refrigerator according to an embodiment of the present invention has an effect of easily providing after-sale service for a customer through state check and diagnosis of the refrigerator in a diagnostic system through a communication network because it can output an effective and exact sound, prevent noise or signal error generated during the signal conversion, and facilitate information transmission due to stable signal conversion and exact sound output, by configuring product information with a plurality of frames and coding the product information by frame unit according to a certain manner to output the coded data as a sound including the product information.

Further more, a refrigerator according to an embodiment of the present invention has an effect of reducing the time taken to output or transmit a sound by controlling the signal and frequency characteristics constituting the sound including product information, improving the recognition rate and the transmission rate of the sound by enabling exact data transmission necessary for failure diagnosis, and improving the accuracy of the failure diagnosis by facilitating the failure diagnosis of home appliances using a sound.

In addition, a refrigerator according to an embodiment of the present invention has an effect of exactly transmitting product information even when there is an obstacle in a transmission process of a sound due to a signal interference caused by an ambient environment, by changing the frequency or amplitude of the sound including the product information to re-output it.

BEST MODE FOR CARRYING OUT THE INVENTION

FIG. 1is a diagram illustrating the configuration of a refrigerator and a diagnosis system including the refrigerator according to an embodiment

Referring toFIG. 1, the refrigerator1may be included in the diagnostic system to undergo a diagnosis of the state and failure thereof from a service center200. The service center200may include a diagnostic server having information on the refrigerator1and a diagnostic program.

The diagnostic system of the refrigerator1is configured in such a manner that, when a refrigerator1in each home outputs information about the operation thereof as a sound, the sound, which includes product information, is transmitted to a service center200over a telephone network so that the service center200may diagnose the state of the refrigerator1to determine whether the refrigerator1is out of order.

The refrigerator1includes a display unit for displaying certain data. The display unit is a light emitter such as a light emitting diode (LED), a liquid crystal display (LCD) or an organic electro-luminescent (EL) display, and visually displays state information or failure information of the refrigerator1. The refrigerator1further includes a sound output unit71for outputting a sound. The sound output unit71reproduces and outputs information about the operation, state or failure of the refrigerator1as a certain sound.

When the refrigerator1malfunctions or operates abnormally, it informs a user of occurrence of a failure through a display unit or a sound output unit (S1).

The user verifies the product information of the refrigerator1displayed on the display unit of the refrigerator1to control the operation of the refrigerator1or ask the service center200for repair of the refrigerator1. In this case, the user may contact the service center200to notify the service center200that a failure has occurred in the refrigerator1and ask for an advice on the failure (S2).

When the user connects to the service center200and manipulates a selector of an input device in the refrigerator1in response to a request from the service center200(S3), the refrigerator1converts the product information into a certain sound and outputs the sound through the sound output unit71. The sound including the product information, which has been output in this manner, is transmitted to the service center200over a communication network (S4).

In this case, while the user is notifying the service center200of model information and failure symptoms of the refrigerator1, the user may place a telephone81close to a sounding portion of the refrigerator1, that is, the sound output unit during the calling with the service center200to transmit the sound including the product information of the refrigerator1to the service center200. In this manner, the user may transmit the sound including the product information of the refrigerator1to the service center200using his/her telephone or mobile phone to request an after-sale service (A/S) for the refrigerator1.

When the service center200receives the sound outputted from the refrigerator1over a communication network connected thereto, for example, a telephone network, the service center200checks the product state of the refrigerator1based on the received sound to diagnose whether the refrigerator1is out of order (S5).

According to a result of the diagnosis, the service center200dispatches a service technician93to the user's home to provide a service suitable for the product state and failure diagnosis of the refrigerator1(S6). In step S6, the diagnosis result may be transmitted to a terminal of the service technician93. According to circumstances, the service center200may connect with the user through the communication network to provide the diagnosis result to the user in the form of a voice through a customer service agent or in the form of certain data. Also, the diagnosis result may be transmitted to the user's email address or mobile phone.

The refrigerator1is configured as described below, outputting the product information as a certain sound.

FIG. 2is a diagram illustrating a refrigerator and a relation between the refrigerator and a service center according to an embodiment.

Referring toFIG. 2, when a failure occurs in a refrigerator1, failure information is displayed on a display unit, or a certain alarm sound is outputted. Accordingly, a user connects to a service center200, and manipulates a selection unit according to an instruction of the service center200.

As the user manipulates the selection unit, the refrigerator1receives a signal output command, converts the production information into a sound signal through a modulator, and outputs the sound signal as a certain signal sound100through a sound output unit71.

In this case, the signal sound100output through the sound output unit71is transmitted to the service center200through a terminal81connected to a certain communication network. In this case, examples of the communication networks include a telephone network or a mobile communication network. Examples of the terminal81include telephones or mobile terminals.

The service center200acquires operation and failure information of the refrigerator1through an analysis of the signal sound100. Accordingly, the service center200delivers a countermeasure against the malfunction of the refrigerator1, and dispatches a service technician.

FIG. 3is a front view illustrating a refrigerator according to an embodiment.FIG. 4is a diagram illustrating the refrigerator ofFIG. 3with its doors opened.FIG. 5is a block diagram illustrating a core figuration of a refrigerator according to an embodiment.

Referring toFIGS. 3 through 5, a refrigerator1has an external appearance defined by a case110defining an internal space divided into a refrigeration compartment120and a freezer compartment130, and refrigeration compartment doors121and122opening and closing the refrigeration compartment120, and a freezer compartment door131opening and closing the freezer compartment130.

The refrigeration compartment doors121and122include a left refrigeration compartment door121pivotably connected to the left side of the case110and a right refrigeration compartment door122pivotably connected to the right side of the case110, and are opened and closed by a user. The freezer compartment door131is coupled slidably along the case110, and holds food. The freezer compartment door131is pushed toward the inner side of the case110to close the freezer compartment130, and is drawn from the case110to open the freezer compartment130.

In the present embodiment, the refrigerator1is described as a refrigerator of a three-door type, in which three doors open and close the refrigeration compartment120and the freezer compartment130, the refrigeration compartment120is provided in the upper portion of the case110, and the freezer compartment130is provided in the lower portion of the case110under the refrigeration compartment120. However, the embodiments are not limited to the above configuration. For example, the refrigerator1may be a refrigerator of a two-door type, in which the case110is divided into left and right portions thereof, one is provided with a freezer compartment, and the other is provided with a refrigeration compartment. Also, doors may be pivotably provided at the both sides of the case110to selectively open and close the freezer compartment and the refrigeration compartment. In addition, the refrigerator1may be a refrigerator of a four-door type, which has a similar structure to that of the present invention, but further includes an additional freezer compartment that is opened and closed by a door of a sliding type.

Refrigeration compartment door grips123and124are provided on the refrigeration compartment doors121and122to be opened and closed by a user. A freezer compartment door grip133is provided on the freezer compartment door131to be opened and closed by a user.

A dispenser125may be provided on the front surface of the refrigeration compartment doors121or122to allow a user to easily take out ice or water from the dispenser125. A control panel140may be provided over the dispenser125to control the operation of the refrigerator1and output the state of the refrigerator1on an image and/or sound through a display unit141.

The control panel140may include a display unit141, which is a light emitter such as a light emitting diode (LED), a liquid crystal display (LCD) or an organic electroluminescent (EL) display, which visually displays displaying state information or failure information of the refrigerator1, a sound output unit including a buzzer or a speaker to output a sound, and an input unit142implemented with a mechanical button or a capacitive/resistive touch button that receive various operation commands from a user.

The refrigerator1may perform refrigeration and freezing through a thermal exchange with ambient air using a phase change of refrigerant that is achieved in a cyclic process involving compression, expansion, evaporation, and condensation of refrigerant circulating along a refrigerant pipe. To this end, the refrigerator1includes a compressor (not shown) for compressing refrigerant, an expansion valve (not shown) for expanding refrigerant, a thermal exchanger (not shown) serving as an evaporator for evaporating refrigerant, and a thermal exchanger (not shown) serving as a condenser for condensing refrigerant.

Also, the refrigerator1further includes a refrigeration compartment fan184for blowing cooled air to the refrigeration compartment120, a freezer compartment fan186for blowing cooled air to the freezer compartment130, and a sensing unit190for sensing the operation state of various components constituting the refrigerator1.

The sensing unit190includes at least one sensing means for sensing temperature, pressure, voltage, current, water level, and rotational speed, and applies sensed or measured data to a control unit160.

More specifically, the sensing unit190may include a refrigeration compartment temperature sensor191for sensing the temperature of the refrigeration compartment120and a freezer compartment temperature sensor192for sensing the temperature of the freezer compartment130, a defrost sensor193for sensing frost covered on the surface of the evaporator to determine whether to perform a defrost operation, a refrigeration compartment fan motor sensor194for sensing whether the refrigerator compartment fan184normally operates or not, a freezer compartment fan motor sensor195for sensing whether the freezer compartment fan186normally operates or not, and a condenser fan motor sensor196for sensing whether a condenser fan189for emitting a heat generated in the condenser upon heat-exchange with refrigerant normally operates or not.

Also, the refrigerator1may include an ice maker for making ice, which may include a water passage through which water necessary for ice flows and an ice tray in which water supplied through the water passage gathers and freezes to ice having a certain shape. In this case, the sensing unit190may further include an ice maker water passage temperature sensor197for measuring the temperature of water in the water passage, and an ice maker tray temperature sensor198for measuring the temperature in the ice tray. Ice frozen by the ice maker may be supplied through the dispenser125.

The control unit160analyzes the state information of the refrigerator1based on information collected through various sensors constituting the sensing unit190. An input/output control unit143controls the state information analyzed by the control unit150to be displayed on the display unit141.

More specifically, the input/output control unit143mediates between the control unit160and the input unit142and the display unit141provided in the control panel140. The input/output control unit143allows various control commands inputted through the input unit142by a user to be delivered to the control unit160, and allows symbols, texts, and/or images such as icons to be displayed on the display unit141in response to the inputted control command, or, when information sensed by the sensing unit190is delivered through the control unit160, allows state information based thereon to be displayed on the display unit141.

The input unit142includes at least one input means for inputting a certain signal or data into the refrigerator1by a user. The input unit142includes a manipulator144receiving various control commands about operations of the refrigerator1and a selector145receiving a smart diagnostic mode command for failure diagnosis of the refrigerator1.

The selector145includes at least one input means. When smart diagnostic mode is selected, a signal output command may be applied to the control unit160such that the product information is outputted as a certain sound through the sound output unit150.

As the refrigerator enters smart diagnostic mode, the selector145allows the sound output unit150to turn on/off. That is, when a signal output command is inputted through the selector145, the product information is outputted as a certain sound in response to the control signal of the control unit160. In this case, the sound output unit150may operate to output a sound including the product information.

When the control commands are inputted through the manipulator144, data such as operation course and operation setting are applied to the control unit160according to the operation of the refrigerator1. Also, the manipulator144may receive settings regarding the sound output. That is, the manipulator144makes it possible to set a sound output method and the volume of an outputted sound.

The input unit142such as the selector145and the manipulator144may be configured with buttons, dome switches, resistive/capacitive touch pads, jog wheels, jog switches, finger mice, rotary switches, jog dials, and other devices that generate certain input data by manipulations such as pushing, rotating, pressing, and contact.

On the other hand, the selector145may be configured with a certain input means separately from the manipulator144. The selector145may perform a specific function by a button combination of two or more buttons or a typical on/off manner, but may perform different functions according to a specific push pattern such as continuous pushing for a certain time or repeated pushing in a certain time.

For example, the refrigerator1includes a lock button (142fofFIG. 34) for locking the operation buttons, and a freezer compartment temperature setting button (142cofFIG. 34) for setting the temperature of the freezer compartment120. After the refrigerator1enters a lock mode in which the operation buttons are locked by pushing the lock button142fin a state where the refrigeration door122is opened, the refrigerator1enters smart diagnostic mode by pushing a specific button (e.g., the freezer compartment temperature setting button142c) for a predetermine duration (e.g., about 3 seconds).

Thus, the refrigerator1may enter smart diagnostic mode only when a user obviously intends to enter smart diagnostic mode.

A memory172stores control data for controlling the operation of the refrigerator1and reference data used during the operation control of the refrigerator1.

In this case, the memory172includes a data storage such as a read only memory (ROM) or electrically erasable programmable ROM (EEPROM) for storing control data on the refrigerator1.

The storage unit174is a buffer for the control unit160that temporarily stores data. The storage unit174may be, for example, a dynamic random access memory (DRAM) or static RAM (SRAM). In some cases, the storage unit174may be incorporated into the control unit160or memory172.

That is, the memory172stores the product information including the operation information, the usage information, and the failure information. The storage unit174stores temporary data on the operation information and the failure information that are generated during the operation of the refrigerator1. The product information may include frequency of usage of the refrigerator1, refrigeration courses such as quick-freezing, optional setting information, error codes, sensor measurement values, data calculated by the control unit, operation information of the respective units, user setting information and/or operation state information.

More specifically, the memory172stores operation state data generated during the operation of the refrigerator1, operation information such as setting data inputted by the manipulator144such that the refrigerator1performs a certain operation, frequency of performance of a specific operation by the refrigerator1, usage information including the model information of the refrigerator1, and failure information including the malfunction cause and/or malfunctioning components of the refrigerator1

When the refrigerator1operates, the failure information may include various pieces of information including failure information generated during the respective operations, mechanical failure information of the refrigerator1, error codes corresponding to the failure information, information of the control unit160, and values sensed by the sensing unit190.

The usage information may include various information including the number of uses of the refrigerator1by the user, a course set by the user, and/or optional setting information set in the refrigerator1. That is, the usage information may include contents inputted to the refrigerator1by the user or information initially set in the refrigerator1.

When a signal for smart diagnostic mode entry is inputted from the selector145, the control unit160fetches the product information stored in the memory172or storage unit174to generate a control signal of a certain format and apply the control signal to the modulator182. Also, as the selector145is manipulated, the control unit160controls the sound output unit150to operate.

The control unit160includes a main controller161for controlling a flow of data inputted or outputted to or from the refrigerator1, and generating a control command according to data inputted from the sensing unit190to control the refrigerator1to operate, and an encoder162for converting the product information into a control signal of a certain format to output sounds according to the input of the selector145.

When the refrigerator1enters smart diagnostic mode according to the input of the selector145, the main controller161outputs a startup sound informing the initiation of smart diagnostic mode through the sound output unit150and displays certain data indicating the execution of smart diagnostic mode on the display unit141. In this case, the I/O control unit143may intervene between the main controller161and the display unit141as described above.

Also, when the control signal generated in the encoder162is applied to the modulator182to be outputted through the sound output unit150, the main controller161controls the sound output unit150to output a certain indication sound before and after the output of the sound. According to embodiments, the indication sound may be omitted.

The refrigerator1may include two or more sound output units150. In this case, the sound output units150may include a first sound output unit for outputting the product information or the failure information of the refrigerator1and a second sound output unit for outputting various announcement messages to a user according to the operation state of the refrigerator1. The first sound output unit and/or the second sound output unit may be implemented with a sound output means such as a buzzer or a speaker. The configuration and arrangement of the sound output means constituting each sound output unit will be described later.

In the present embodiment, as described above, the refrigerator1enters smart diagnostic mode by pushing the freezer compartment temperature setting button that is a specific operation button, for a predetermined duration (e.g., about 3 seconds), in a state where the operation buttons are locked by the lock button. Accordingly, operations of buttons except the power button and the freezer compartment temperature setting button, the function of which is restricted with smart diagnosis performance, may be restricted before the release of the lock button.

The encoder162fetches the product information stored in the memory172to encode the product information according to a certain encoding scheme, and adds a preamble and an error check bit to the resulting data signal to generate a control signal of a certain format. The encoder162generates a control signal including a plurality of symbols by encoding the product information.

In the course of generating the control signal, the encoder162may divide the control signal into a plurality of frames by a certain size and packetize the frames into a packet. Also, the encoder162may set an inter-frame space (IFS) between the frames of the control signal such that no sound is outputted for a certain time. Also, during signal conversion, the encoder162may set a dead time in a symbol at a section in which a data value is changed, in order to remove a reverb effect that affects a next signal conversion due to the principle of charging and discharging of a capacitor.

Assuming that the length of each of the symbols constituting the control signal is a symbol time, and the fundamental length of a frequency signal constituting a sound with respect to the sound outputted from the sound output unit150according to each symbol is also a symbol time, the encoder162may set a dead time within the symbol time with respect to one symbol. In this case, the length of the dead time varies with the length of the symbol time.

As stated above, the product information includes operation information including operation settings and operation state, usage information, and failure information about a malfunction. The product information is data including a combination of 0 or 1, which is a digital signal of a format readable by the control unit160

The control unit160generates a control signal of a certain format by classifying data of the product information, incorporating specific data about the operation of the refrigerator1into the classified data and dividing the resulting data by a certain size or combining the resulting data, and applies the generated control signal to the modulator182.

Also, the control unit160may change the number of symbols corresponding to output frequency signals according to the number of frequencies used in the modulator182. In this case, the control unit160changes the number of symbols of the control signal corresponding to the number of frequency signals according to the number of frequencies used in the modulator182. That is, in the case where the number of frequencies used is 2n, n symbols of the control signal correspond to one frequency signal.

For example, the control unit160may control the modulator182to convert one symbol of the control signal into one frequency signal when the modulator182uses two frequencies to control the sound output unit150to output a sound, two symbols of the control signal into one frequency signal when using four frequencies, and three symbols of the control signal into one frequency signal when using eight frequencies.

In this case, a symbol time may also be changed according to the number of symbols corresponding to one frequency signal.

The modulator182applies a drive signal to the sound output unit150in response to the control signal from the control unit160such that the sound output unit150outputs a sound. The sound outputted in this manner includes product information.

The modulator182applies the drive signal to the sound output unit150such that a specified frequency signal corresponding to one of the symbols constituting the control signal is outputted for a symbol time.

In this case, the modulator182performs a control operation such that the sound is outputted through a plurality of frequency bands in accordance with the control signal while changing the number of symbols for each frequency signal based on the number of used frequencies in accordance with setting of the control unit160.

That is, as described above, one frequency signal may be outputted per symbol for a specified time when two frequencies are used, and one frequency signal may be outputted per 2 symbols for the specified time when four frequencies are used.

When four frequencies are used, the modulator182controls the sound output unit150in response to a control command from the control unit160such that one frequency signal is outputted per two symbols of the control signal, so that a sound including a combination of a plurality of frequency signals is outputted. When eight frequencies are used, the modulator182performs a control operation such that one frequency signal is outputted per three symbols of the control signal.

As a result, the frequency band and length of a sound outputted from the sound output unit150are changed according to the number of frequencies used in the modulator182. Whenever the number of frequencies used is doubled, the total length of the outputted sound (total sound output time) is reduced by ½.

That is, in the case where the modulator182controls the sound output unit150using frequencies of a number corresponding to 2n, one frequency signal is outputted per n symbols of the control signal and the length of a sound is reduced to (½)n.

The modulator182includes frequency oscillators (not shown) for generating as many oscillation frequencies as the number of available frequencies and controls the sound output unit150to output frequency signals from frequency oscillators that are specified in accordance with the control signal.

The modulator182converts the control signal from the control unit160into the sound using one of frequency-shift keying, amplitude-shift keying, or phase-shift keying while controlling the sound output unit150to output the sound in accordance with the control signal.

Frequency-shift keying converts the control signal into a signal having a frequency corresponding to a data value of the control signal, amplitude-shift keying converts the control signal by changing the amplitude of the control signal according to the data value, and phase-shift keying converts the control signal by changing the phase of the control signal according to the data value.

Binary frequency-shift keying (BFSK), which is a type of frequency-shift keying, converts the control signal into a signal of a first frequency when the control signal has a data value of 0 and into a signal of a second frequency when it has a data value of 1. For instance, BFSK converts a data value 0 into a signal of a frequency of about 2.6 KHz and converts a data value 1 into a signal of a frequency of about 2.8 KHz, as will be described later with reference toFIG. 7.

Amplitude-shift keying may convert the control signal into a signal of a frequency of about 2.6 kHz with an amplitude of 1 when the control signal has a data value of 0 and an amplitude of 2 when it has a data value of 1.

While the modulator182has been described as using frequency-shift keying as an example, the modulation scheme used may be changed. Also, the frequency bands used are merely an example and may be changed.

If a dead time is set in the control signal, the modulator182discontinues modulation in a section in which the dead time is set in the control signal. The modulator182modulates the control signal using pulse width modulation (PWM) and switches an oscillation frequency for modulation off during the section, in which the dead time is set, to temporarily discontinue the frequency signal modulation during the dead time. This removes inter-symbol reverberation of the sound outputted from the sound output unit150.

The sound output unit150is activated or deactivated according to a control command from the control unit160. The sound output unit150outputs a certain sound including product information by outputting a frequency signal corresponding to the control signal for a specified time under the control of the modulator182.

Here, one or more, preferably, two or more of sound output units160may be provided. For example, when two sound output units are provided, one of the two sound output units may output a sound including product information and the other may output an alarm sound or an effect sound corresponding to state information of the refrigerator1and may also output an indication sound before smart diagnostic mode is entered or before the sound is outputted.

The sound output unit150is deactivated after completely outputting the control signal as the certain sound in accordance with the output of the modulator182. When the selector145is manipulated again, the sound output unit150is reactivated to output the certain sound including product information through the above-described process.

While a sound output unit150such as a speaker or a buzzer may be used as the sound output unit150, a speaker having a wide reproduction frequency range is desirable in order to use a plurality of frequency bands.

When smart diagnostic mode is entered, the sound output unit150outputs a startup sound indicating the start of smart diagnostic mode according to a control command from the main controller161and also outputs respective certain indication sounds at the start and end of outputting a sound including product information.

In response to a control command from the main controller161, the display unit141displays, on a screen, information such as information received from the selector145and the manipulator144, operating state information of the refrigerator1, and information associated with completion of the operation of the refrigerator1. When the refrigerator1operates abnormally, the display unit141also displays failure information about the malfunction on the screen.

The display unit141displays information indicating smart diagnostic mode when smart diagnostic mode has been started in response to a control command from the main controller161. When the sound output unit150outputs a sound, the display unit141displays the progress of the sound output in the form of at least one of text, image, and numeral.

The refrigerator1may include an output unit such as an illuminating or flickering lamp, a vibrator, or the like, which will not be described herein, in addition to the sound output unit150and the display unit141.

The refrigerator1with the above-described configuration outputs a certain sound and delivers product information thereof to the service center200in the following manner.

Hereinafter, an exemplary conversion of the product information into a sound signal by the modulator182of the refrigerator1will be described below.

FIG. 6is a waveform diagram illustrating types of frequencies outputted from the sound output unit of the refrigerator ofFIG. 3.

The modulator182controls the operation of the sound output unit150through modulation of a control signal based on a plurality of frequencies f1to fN such that a sound having a combination of the plurality of frequencies is outputted, as shown inFIG. 6.

In this case, the number of symbols corresponding to one frequency signal is changed depending on the number of frequencies used, and the length of a sound output is changed accordingly. Here, a time taken for one frequency signal to be outputted is determined in consideration of a minimum time required for one frequency signal to be outputted as a sound through the sound output unit150, a time taken for one frequency signal to be recognized as a sound by the portable terminal81, and sampling in the portable terminal81.

Owing to the use of the plurality of frequencies, the modulator182includes frequency oscillators of a number corresponding to the number of the frequencies used, and controls the sound output unit150to output specified frequency signals corresponding to the control signal.

Here, the plurality of frequencies used are selected such that they have a frequency separation of a certain band or more therebetween to prevent inter-frequency interference. Also, the plurality of frequencies used are selected such that a bandwidth BW thereof is within the range of a reproducible frequency band of the sound output unit150.

FIG. 7is a waveform diagram illustrating an example of conversion of data into signals of a plurality of frequencies in a refrigerator1of the present invention

Referring toFIG. 7, when four frequencies are used in the modulator182, a corresponding frequency signal is outputted per 2 bits of a control signal.

The modulator182outputs, through the sound output unit150, a first frequency f11201when the control signal is ‘00’, a second frequency f12202when ‘01’, a third frequency f13203when ‘10’, and a fourth frequency f14204when ‘11’.

In this case, the modulator182includes frequency oscillators for generating the first to fourth frequencies, respectively, and generates a synchronous signal to each frequency oscillator, so that a corresponding frequency signal is outputted per 2 bits of a control signal from the control unit160to the sound output unit150.

FIG. 8(a)shows an example of the control signal,FIG. 8(b)shows an example of signal conversion in use of two frequencies, andFIG. 8(c)shows an example of signal conversion in use of four frequencies.

In the case where the control signal is ‘010100101110’ as shown inFIG. 8(a)and two frequencies are used, the modulator182outputs a first frequency f1for 0 of the control signal and a second frequency f2for 1 of the control signal. As a result, a frequency signal combination as shown inFIG. 8(b)is outputted as a sound through the sound output unit150.

In the case where the first to fourth frequencies f11to f14are used as stated above with reference toFIG. 7, two symbols of the control signal are converted into one frequency signal and the converted frequency signal is outputted as a sound. Accordingly, the modulator182outputs, through the sound output unit150, the first frequency f11for 00 of the control signal, the second frequency f12for 01, the third frequency f13for 10, and the fourth frequency f14for 11. Consequently, the respective frequencies f12, f12, f11, f13, f14and f13corresponding to the control signal ofFIG. 8(a)are outputted through the sound output unit150, as shown inFIG. 8(c).

The length of an actually output sound varies depending on the number of frequencies used. That is, one symbol, one bit, corresponds to one frequency signal inFIG. 8(b), whereas two symbols, two bits, correspond to one frequency signal inFIG. 8(c).

That is, in the case ofFIG. 8(b)using the two frequencies, a total of 12 frequency signals each having a certain length, corresponding to a control signal including 12 symbols, are outputted as a sound, and, in the case ofFIG. 8(c)using the four frequencies, a total of 6 frequency signals each having a certain length, corresponding to the control signal, are outputted as the sound.

In the case where the sound corresponding to the control signal is outputted using the plurality of frequencies as shown inFIG. 8, it is outputted through the sound output unit150as shown inFIG. 9.FIG. 9shows waveforms of the frequency signals ofFIG. 8.

Referring toFIG. 9, because one frequency signal is outputted per 2 symbols (2 bits) of a control signal when four frequencies are used, the control signal ofFIG. 9(a)is modulated into a frequency signal combination as shown inFIG. 9(c), which is then output as a sound through the sound output unit150.

When the sound is provided with six frequency signals by employing four frequencies with respect to the same control signal as shown inFIG. 9(c), it has a shorter length than that when provided with twelve frequency signals by employing two frequencies with respect to the same control signal as shown inFIG. 9(b). Because a time taken for one frequency signal to be outputted is constant, the length of the sound outputted from the sound output unit150in the case ofFIG. 9(b)is increased to twice that in the case ofFIG. 9(c), and the output time thereof is thus increased to twice that in the case ofFIG. 9(c).

That is, because each frequency signal is outputted through the sound output unit150for a specified output time ST, the length of the sound when four frequencies are used is reduced to ½ that when two frequencies are used.

Here, an output time ST taken for one frequency signal to be outputted is set in consideration of at least one of a minimum time required for one frequency signal to be outputted as a sound through the sound output unit150, a time taken for one frequency signal to be input, recognized and output as a sound by the portable terminal81for transmission through the portable terminal81, a sampling time in the portable terminal81, a noise recognition time in the portable terminal81, and a transmission rate in transmission over the communication network.

Preferably, the output time ST may be set to a certain value or more such that the diagnostic server of the service center can accurately perform data conversion in a process of recognizing and analyzing a sound.

That is, when the output time ST of one frequency signal is short, the frequency signal may not be outputted as a sound through the sound output unit150, may not be recognized as a sound by the portable terminal81or may be distorted when sampled by the portable terminal81, so as not to be recognized by the diagnostic server. Also, the frequency signal may be recognized by the portable terminal81, not as a sound from the refrigerator1, but as noise, or may be accompanied by an error or noise during transmission over the communication network. Also, when the output time ST of one frequency signal is long, the total length of a sound is increased. In this context, it is desirable to set the output time ST in consideration of all the above conditions.

For these reasons, it is desirable that the output time of one frequency signal be set within the range of about 3 ms to about 30 ms. It is desirable that the number of pulses included in one frequency signal be set to 8 or more.FIG. 9schematically illustrates a comparison between output sounds based on the number of frequencies.

FIG. 10illustrates another example of signal conversion using a plurality of frequencies.

Referring toFIG. 10, 8 or more frequencies may be used to output a sound. For example, in order to output a sound including product information, the modulator182may use 8 frequencies as shown inFIG. 10(a)or 16 frequencies as shown inFIG. 10(b).

When 8 frequencies are used as shown inFIG. 10(a), one frequency signal corresponding to three symbols (3 bits) of a control signal is outputted.

As a result, the modulator182applies a corresponding frequency signal per three symbols (3 bits) of the control signal to the sound output unit150such that the frequency signal is outputted as a sound for a specified time.

For example, the modulator182may output a frequency21f21for 000 of the control signal, a frequency22f22for 001, a frequency23f23for 010, a frequency24f24for 011, a frequency25125for 100, a frequency26126for 101, a frequency27127for 110, and a frequency28f28for 111.

The modulator182outputs a specified frequency signal, corresponding to the control signal as stated above, through the sound output unit150for a specified output time ST.

For example, in the case where a control signal including 120 symbols is modulated into a sound using eight frequencies, one frequency signal is outputted per 3 symbols and a total of 40 frequency signals corresponding to the control signal are thus output as the sound.

When an output time ST taken for one frequency signal to be outputted is about 12 ms, the total sound output time is about 480 ms because 40 frequency signals are generated for 120 symbols. In the case of a control signal including 240 symbols, the total sound output time is about 960 ms.

When 16 frequencies are used as shown inFIG. 10(b), one frequency signal corresponding to four symbols is outputted as a sound.

For example, a frequency31f31corresponding to 0000 of the control signal, a frequency32f32corresponding to 0001, a frequency33f33corresponding to 0010, a frequency34f34corresponding to 0011, a frequency35f35corresponding to 0100, a frequency36f36corresponding to 0101, a frequency37f37corresponding to 0110, and a frequency38f38corresponding to 0111 may be each output through the sound output unit150for a specified output time ST.

Also, a frequency39f39corresponding to 1000 of the control signal, a frequency40f40corresponding to 1001, a frequency41f41corresponding to 1010, a frequency42f42corresponding to 1011, a frequency43f43corresponding to 1100, a frequency44f44corresponding to 1101, a frequency45f45corresponding to 1110, and a frequency46f46corresponding to 1111 may be each output through the sound output unit150for the specified output time ST.

In this case, when the control signal consists of 120 symbols, 4 symbols are converted into one frequency signal and a total of 30 frequency signals corresponding to the control signal are thus output as a sound. As a result, when an output time ST taken for one frequency signal to be outputted is about 12 ms, the total sound output time of the control signal of 120 symbols is about 360 ms. In the case of a control signal including 240 symbols, the total sound output time is about 720 ms.

FIG. 11is a waveform diagram illustrating another example of data to frequency conversion in the refrigerator1of the present invention, andFIG. 12is a waveform diagram illustrating an example of a signal conversion based on the frequency conversion ofFIG. 11.

Referring toFIG. 11, when the modulator controls the sound output unit to output a sound, it uses four frequencies and outputs one or more thereof simultaneously.

For example, in the case of a control signal including 2 symbols (2 bits), a frequency1f1and a frequency2f2are used for the first symbol such that the frequency1f1is outputted for 0 and the frequency2f2is outputted for 1, and a frequency3f3and a frequency4f4are used for the second symbol such that the frequency3f3is outputted for 0 and the frequency4f4is outputted for 1. Preferably, the frequencies1and2and the frequencies3and4may belong to such bands that they can be readily identified even though output simultaneously.

As shown inFIG. 12, in the case where the control signal is 011001110100, the frequency1f1and the frequency4f4are outputted for 01 on a 2-symbol basis because the first symbol is 0 and the second symbol is 1. Therefore, the frequencies1and4are outputted at the same time.

That is, when 011001110100 are divided 2 bits by 2 bits and each of 01, 10, 01, 11, 01 and 00 is expressed by the frequencies1and2and the frequencies3and4, frequency signals can be outputted as shown inFIG. 12.

FIG. 13is a block diagram illustrating the configuration of a diagnostic server of a service center.

The refrigerator1as configured above outputs a certain signal sound to deliver its product information to the service center200as described below.

When the product information of the refrigerator1is outputted as a signal sound to be transmitted to the service center200through, for example, a telephone network, the product information is inputted to the diagnostic server280provided in the service center200to perform diagnosis on the refrigerator1.

The diagnostic server280may include a communication unit220, a signal processing unit230, a data unit240, a server I/O unit270, a signal detection unit250, a diagnosis unit260, and a server control unit210controlling the overall operations of the diagnostic server280.

The server I/O unit270includes input means such as buttons, keys, touchpads, and switches that are operated by a user, and includes a display means for displaying the operation information and diagnosis result of the diagnostic server. Also, the server I/O unit270includes an external input device and a connection interface for a portable memory unit.

When the input means is manipulated, the server I/O unit270may apply a signal to the server control unit210, so that the diagnostic server may receive a signal sound of the refrigerator1from a telephone or portable terminal of a user that is connected through a telephone network.

The communication unit220transmits and receives data in connection with a computer network of the service center, and may be connected to an external network such as Internet for communication. Particularly, the communication unit220receives signal sound data through the telephone network, upon input of a recording command or receiving command through the input means, according to the control command of the server control unit210

The data unit240stores bit stream data242including control data for the operation of the diagnostic server and signal sound data received from the refrigerator, reference data241for detecting the product information of the refrigerator from the signal sound data, and diagnosis data243for diagnosing the occurrence and cause of a failure. Also, the data unit240stores refrigerator data244including the product information of the refrigerator1that is detected from the bit stream data242.

Here, the reference data241, the bit stream data242, the diagnosis data243, and the refrigerator data244of the data unit240are inputted, managed, and updated by the server control unit210.

The signal processing unit230converts analog signal sound data to store the bit stream data242. In this case, the signal conversion in the signal processing unit230is an inverse conversion with respect to the signal conversion in the refrigerator1. The refrigerator1and the diagnostic server280may convert data through the same signal conversion system by a mutual agreement therebetween. The signal processing unit230may convert a signal sound that is an analog signal of a certain frequency band into a digital signal through the inverse conversion using one of frequency-shift keying (FSK), amplitude-shift keying (ASK), and phase-shift keying (PSK).

The signal detection unit250first detects a preamble informing the start of data from the bit stream converted by the signal processing unit230. Then, the signal detection unit250detects data including the product information based on a detected preamble, and stores the detected data in the data unit240as the refrigerator data244.

The signal detection unit250detects the preamble and the data based on the size of the preamble included in the reference data241and the size of the data, and stores the detected preamble and data in the data unit240as the refrigerator data244.

The diagnosis unit260analyzes the data detected by the signal detection unit250, and determines the state of the refrigerator1and the occurrence of a failure of the refrigerator1. Then, the diagnosis unit260analyzes the cause of the failure to output a diagnosis result.

As an amount of product information is included in the signal sound outputted from the refrigerator1, the diagnosis unit260analyzes each data item including in the product information, and diagnose the refrigerator1according to a correlation between the data items. In this case, the diagnosis unit260performs the diagnosis using a diagnosis algorithm included in the diagnosis data243and reference values according to the diagnosis.

The server control unit210controls the transmission and reception of data through the communication unit220and the flow of data through the server I/O unit270. The signal sound including the product information of the refrigerator1is converted by the signal processing unit230. The operation of the signal detection unit250is controlled to detect data.

Also, the server control unit210applies a control command to each unit such that the diagnosis unit260performs a failure diagnosis on the refrigerator1, using the detected data.

FIG. 14is a graph illustrating an example of repeatedly outputting a signal sound including product information by varying the amplitude characteristics of a refrigerator according to an embodiment of the present invention.

When a user inputs a control command for the failure diagnosis through the selector145, the control unit160controls the product information to be converted into a first sound signal114having predetermined frequency and amplitude signal characteristics.

The first sound signal114includes a plurality of unit signals113. The plurality of unit signals113include first and second frequency signals that are included in the predetermined frequency band. The first and second frequency signals have different frequencies. Hereinafter, it will be assumed that the first sound signal114has a frequency band of about 2 kHz to about 3 kHz. Also, the first frequency signal is assumed to be a frequency signal of about 2.6 kHz, and the second frequency signal is assumed to be a frequency signal of about 2.8 kHz.

The product information includes digital data having a logic data combination of 0 or 1. That is, the product information is stored as digital data in the storage unit174provided in the refrigerator1. The modulator182converts the digital data into an electrical signal having a certain frequency.

When the modulator182converts the digital data including the product information into a sound signal that is an analog signal, the modulator182converts data ‘0’ into a first frequency signal, and converts data ‘1’ into a second frequency signal. In this case, the control unit160retrieves data stored in the storage means. When data ‘0’ is retrieved, the control unit160controls the modulator182to generate the first frequency signal having a frequency of about 2.6 kHz for a predetermined time t. When data ‘1’ is retrieved, the control unit160controls the modulator182to generate the second frequency signal having a frequency of about 2.8 kHz for the predetermined time t. The time t may be set to about 100 ms.

When a user sets the amplitude using an amplitude control unit (not shown) that controls the amplitude of a sound outputted from the sound output unit150by the user, the control unit160controls the modulator182to convert the product information into a sound signal having the set amplitude, and the sound output unit150outputs a sound according to the set amplitude. That is, when a signal interference occurs due to the characteristics of an ambient environment or communication network, a user increases the volume of the sound by increasing the amplitude of the sound using the amplitude control unit. On the other hand, when a user desires a silent environment, the user reduces the volume of the sound by reducing the amplitude of the sound using the amplitude control unit.

As described above, the adjustment of the amplitude of the sound outputted from the sound output unit150is for increasing the accuracy of the product information transmitted to the service center200, by outputting the product information using different amplitudes when there is an error in the product information transmitted to the service center200through the communication network, that is, there is a signal interference caused by the communication network or the ambient environment.

In order to set the amplitude of the sound outputted from the sound output unit150, the input unit142may include a separate amplitude control unit. However, as described above, when a smart diagnosis is executed using a lock button and a freezer compartment temperature setting button, and then the freezer compartment temperature setting button is again pushed to perform the smart diagnosis, it is possible to vary the amplitude of a signal outputted according to a predetermined amplitude characteristic.

In either case where the amplitude is set through a separate amplitude control unit provided in the input unit142, or where a smart diagnosis performance command is inputted once again after the entrance into the smart diagnosis, when a signal sound having a different amplitude is outputted through the sound output unit150, the control unit160controls the modulator182to convert the product information into a second sound signal116. The second sound signal116includes at least one of a third frequency signal having a frequency equal to and an amplitude different from those of the first frequency signal, and a fourth frequency signal having a frequency equal to and an amplitude different from those of the second frequency signal. That is, the first sound114and the second sound116have a frequency equal to and an amplitude different from each other.

FIG. 15is a graph illustrating an example of repeatedly outputting a signal sound including product information by varying the frequency characteristics of a refrigerator according to an embodiment of the present invention.

When a user inputs a control signal for failure diagnosis, the control unit160controls the modulator182to convert the product information into a first sound signal214that is a signal of a predetermined frequency band.

The first sound signal214includes a plurality of unit signals213. The plurality of unit signals213include first and second frequency signals that are included in the predetermined frequency band. The first and second frequency signals have different frequencies. Hereinafter, the first sound signal214has a frequency band of about 2 kHz to about 3 kHz. The first frequency signal is a frequency signal of about 2.6 kHz, and the second frequency signal is a frequency signal of about 2.8 kHz.

The product information includes digital data having a logic data combination of 0 or 1. The product information may be stored as digital data in the storage unit174provided in the refrigerator1. The modulator182converts the digital data into an electrical signal having a certain frequency.

When the modulator182converts the digital data including the product information into a sound signal that is an analog signal, the modulator182converts data ‘0’ into a first frequency signal, and converts data ‘1’ into a second frequency signal. In this case, the control unit160retrieves data stored in the storage unit174. When data ‘0’ is retrieved, the control unit160controls the modulator182to generate the first frequency signal having a frequency of about 2.6 kHz for a predetermined time t. When data ‘1’ is retrieved, the control unit160controls the modulator182to generate the second frequency signal having a frequency of about 2.8 kHz for the predetermined time t. The time t may be set to about 100 ms.

In order to more exactly deliver the product information, the refrigerator1outputs sounds having the product information and different vibration characteristics multiple times. That is, the modulator182converts the product information into a plurality of sound signals having different frequency bands. The sound output unit150continuously outputs a plurality of sounds having different vibration characteristics corresponding to the plurality of sound signals. Hereinafter, it will be assumed that a first sound is outputted and then a second sound is outputted.

The modulator182converts the product information into the first sound signal214, and then again converts the product information into the second sound signal216. The second sound signal216differs from the first sound signal214in the frequency band. In this case, the second sound signal216includes a plurality of second unit signals215, each of which is a third frequency signal included in the frequency band of the second sound signal216, or a fourth frequency signal having a frequency different from that of the third frequency signal. Hereinafter, it will be assumed that the second sound signal216has a frequency band of about 3 kHz to about 4 kHz. Also, the third frequency signal is assumed to be a frequency signal of about 3.0 kHz, and the fourth frequency signal is assumed to be a frequency signal of about 3.5 kHz.

As described above, since the modulator182converts the product information into the first sound signal214and the second sound signal216having different frequency bands, the sound output unit150outputs a first sound corresponding to the first sound signal214, and then again outputs a second sound corresponding to the second sound signal216. In this case, the first sound and the second sound include the same product information, respectively.

Accordingly, even when a signal interference occurs due to the ambient environment of the refrigerator1, since the refrigerator1continuously outputs sounds having different vibration characteristics and the same product information, the product information can be more exactly transmitted.

The control unit160may control the sound output unit150to continuously output sounds having different frequency chacteristics. Similarly to those described with referenceFIG. 14, when the smart diagnosis is executed one time, and then a user inputs a product information output command, the control unit160may also control sounds having different frequency characteristics to be re-outputted.

FIG. 16is a flowchart illustrating a diagnosis method of a refrigerator diagnosis system according to an embodiment. Referring toFIG. 16, when the refrigerator1outputs product information as a certain sound signal, the sound signal is transmitted to the service center200over a communication network through which the user is connected to the service center200.

The service center200receives complaints or failure details from a user (S110), and then the diagnostic server280of the service center200performs a failure diagnosis. The diagnostic server280of the service center200receives the sound signal outputted from the refrigerator1(S120), and converts the sound signal according to a certain scheme to extract the product information (S130). Then, the diagnostic server diagnoses the state, failure, and failure cause of the refrigerator1using a plurality of data included in the product information and starts the failure diagnosis to obtain a measure against the failure (S140).

The diagnosis unit260of the diagnostic server280then obtains version information of the refrigerator diagnostic system and model information of the refrigerator1through the plurality of data included in the product information and analyzes diagnosis data included in the product information to perform the failure diagnosis on the refrigerator1.

The diagnosis unit260first analyzes state information or an error code included in the diagnosis data included in the product information and compares data associated with the state information or error code with failure diagnosis data243or reference data241to perform the failure diagnosis. Basically, the diagnosis unit260can use all diagnosis data included in the product information. However, the diagnosis unit260can use state information or an error code included in the diagnosis data to analyze data associated with the state information or error code, thereby checking the state of the refrigerator1and performing failure diagnosis more quickly. Here, the diagnosis unit260classifies diagnosis data included in the product information according to a certain criterion, i.e., according to the state information or error code, to find and diagnose a failure that is the most likely cause of malfunction of the refrigerator1.

The diagnosis unit260checks whether error codes are set in the plurality of diagnosis data included in the product information (S150). When the error codes are set, the diagnosis unit260diagnoses a failure using the diagnosis data corresponding to the respective error codes (S250).

On the other hand, when the error codes are not set, i.e., an error code value is zero, the diagnosis unit260does not determines that there is an error in the refrigerator1, but performs failure diagnosis using diagnosis data and state information included in the product information other than the error codes, as long as a user considers the refrigerator1is out of order, with respect to the complaints of the user (S160). In this case, when an error occurs but any error code is not generated in the refrigerator1, or when an error that has not been registered occurs, the failure diagnosis as described above may also be performed.

When an error code is not set, as long as an error code is not generated or a failure diagnosis is needed with respect to the complaints of a user, a system associated with the failure reception may be checked, and diagnosis data associated therewith may be extracted to perform failure diagnosis on the refrigerator1.

When failure diagnosis can not be performed using associated diagnosis data, the cause of the failure may be analyzed using all diagnosis data. When the cause of the failure can not be found using the diagnosis data, a service technician may be dispatched to solve the problem.

The diagnosis unit260diagnoses the failure causes, and derives a measure, i.e., a solution against the failure (S170). When the failure cause and solution are derived from the failure diagnosis, the diagnosis unit260stores the failure cause and solution as a diagnosis result (S180).

In this case, since there may be a plurality of failures, the diagnosis unit270may perform additional diagnosis using other related diagnosis data (S160through S180).

When the diagnosis is completed, the diagnosis unit260applies the diagnosis result to the server control unit210. The server control unit210generates a final diagnosis result using the diagnosis result applied from the diagnosis unit260(S200). Upon occurrence of one or more failures, since there are various causes and solutions to the failures, the server control unit210generalizes at least one diagnosis result applied from the diagnosis unit260to generate the final diagnosis result.

The server control unit210first outputs the state of the refrigerator or the result about occurrence of failures and failure causes of the refrigerator1through the server I/O unit270(S200). In this case, when there are one or more failure causes, the result may be displayed in a list. If any item of the result of the failure causes is selected, a solution thereto is outputted (S210). The server I/O unit270may include a server input unit and a server output unit. When there is a startup signal of a specific pattern in a signal sound transmitted through the communication network, a server-side consultant detects the startup signal to input a command through the server input unit. The command allows the signal sound to begin to enter the communication unit220. The server output unit outputs the diagnosis result. The server output unit may simultaneously display the cause of the failure and the result of the diagnosis on one screen. The display pattern may be changed. An exemplary screen configuration of the server output unit will be described later with reference toFIG. 17.

The server control unit210may transmit the diagnosis result via an email or message using a registered email address or telephone number of the user (S220).

Here, a consultant of the service center200may check the diagnosis result displayed on the screen. When the consultant of the service center200selects one of items, a solution thereto may be displayed on the screen. The consultant of the server center200may also provide voice guidance on the displayed cause and solution to a user connected through a telephone. Also, the consultant of the service center200may also perform a procedure for scheduling an appointment for a service technician to visit the user's home according to the cause and solution. According to embodiments, the diagnosis result may be transmitted to the user via an E-mail or message.

When the solution includes dispatching of a service technician, the server control unit210may transmit the diagnosis result to the terminal of the service technician (S230and S240).

On the other hand, a user may perform failure diagnosis using a separate diagnostic terminal having a failure diagnosis function. The diagnostic terminal may perform the failure diagnosis using a certain sound outputted from the refrigerator1.

The diagnostic terminal may perform the failure diagnosis by analyzing a sound outputted from the refrigerator1using a database and a failure diagnosis program like the diagnostic server. The diagnostic terminal may use diagnosis data like the diagnostic server, and may output a diagnosis result. The diagnostic terminal may directly solve the failure cause according to the failure diagnosis result that is outputted, or may ask the server center200for dispatch of a service technician. In this case, a user may transmit the failure diagnosis result of the diagnostic terminal to the service center200. Also, the service technician may directly use the diagnostic terminal.

Hereinafter, although it will be described as an example that the failure diagnosis is performed by the diagnostic server of the service center200, but the failure diagnosis may also be performed by the diagnostic terminal.

FIG. 17is a diagram illustrating a screen of a server output unit of a service center outputting diagnosis information according to an embodiment of the present invention.

Various pieces of diagnosis information may be displayed on the screen of the server output unit such that a consultant of the service center can verify the diagnosis information. Specifically, the diagnosis information may include customer setting information I that is set by a user, operating information II of the refrigerator1, diagnosis result III, and action information IV according to the diagnosis result.

Hereinafter, an exemplary process for performing failure diagnosis of the refrigerator1will be described in detail with reference toFIG. 17.

The customer setting information I includes configuration information including freezer compartment target temperature (F Room Target Temp), refrigeration compartment target temperature (R Room Target Temp), information on activation of the quick-freezing function (Ultra Ice State) and key-lock state of keys provided in the input unit142, and mode information including a display mode showing whether the display mode is set for exhibition in a shop, and a test mode showing whether the test mode for a test in the release stage is set.

The operating information II includes sensing information (F Room Sensor Temp) of the freezer compartment temperature sensor192, sensing information (R Room Sensor Temp) of the refrigeration compartment temperature sensor191, operation setting information (F-fan Output) of a freezer compartment fan, response information (F-fan Feedback) of the freezer compartment fan, operation setting information (R-fan Output) of a refrigeration compartment fan, response information (R-fan Feedback) of the refrigeration compartment fan, operation setting information (C-fan output) of a condenser fan, response information (C-fan Feedback) of the condenser fan, operation setting information (I-fan Output) of an ice maker fan, response information (I-fan Feedback) of the ice maker fan, operation setting information (Comp Operation) of a compressor, and operation setting information (Def's Operation) of a defrost heater.

The diagnosis result III shows a failure diagnosis result of the refrigerator, based on the customer setting information I and/or operating information II. InFIG. 17, since the freezer compartment fan is set as operating (F-fan Output=On), but the response information of the freezer compartment fan is set to 0, the freezer compartment fan does not operate normally.

Accordingly, the diagnosis result III indicates that a freezer compartment fan motor does not operate normally (Freezer Fan Motor Error).

If the failure cause of the refrigerator1is diagnosed as the breakdown of the freezer compartment fan, the action information according to the diagnosis result shows further actions necessary for repair such as checking whether the connection of the freezer compartment fan motor is normal (Check for loose connection), checking whether a connector of the freezer compartment fan motor is frozen (Check the connector frozen), checking whether the motor is frozen (Frozen), whether the rotation of the motor is locked (Lock), or whether the motor is overheated (Burn) by verifying the freezer compartment fan motor and a PCB circuit-connected to the motor (Check for Freezer Fan Motor Wire), checking whether a main PCB constituting the control unit is overheated (Check for Main PCB burnt), and checking whether the voltage state of the main PCB is normal (Check the Main PCM Voltage) by measuring an output voltage (Output) and a response voltage (Feedback).

Accordingly, the consultant of the service center may instruct a user connected through a telephone or a service technician visiting the user of the further actions, or may transmit an E-mail or mobile phone message to the user and/or the service technician as described above.

FIG. 18is a diagram illustrating encoding of product information of a refrigerator according to an embodiment of the present invention.

Upon entrance into smart diagnostic mode, the control unit160fetches already-stored product information to encode it, and generates a control signal of a certain format.

The encoder162encodes the product information by applying an error coding method for recovering a bit error, in order to deal with a data loss that may occur in a course of transmitting the product information outputted as a sound through a communication network. For example, the encoder162may utilize a Forward Error Correction (FEC) encoding method.

In this case, the encoder162encodes the product information using a convolution code. Here, the diagnostic server of the service center performs decoding using a Viterbi decoding algorithm, corresponding to such an encoding method.

The encoder162performs encoding using a logic circuit consisting of a shift register and XOR gates, which is based on a ½ code rate outputting 2-bit in response to an input of 1-bit. Since the ½ code rate requires a lot of redundant bits, the number of redundant bits is reduced using a puncturing algorithm.

The puncturing algorithm is a method of deleting bits in a specific pattern from output values that are encoded using the ½ code rate. The deleting pattern is represented as a puncturing matrix. In the puncturing matrix, 1 indicates non-deleting, and 0 indicates deleting. When using the puncturing algorithm, since the amount of transmission data is reduced, a desired data rate can be satisfied. It is desirable to vary the puncturing matrix in consideration of the transmission rate.

For example, as described inFIG. 18A, if data i0, i1, i2, i3, i4, i5, and i6are inputted in the convolution coding based on the ½ code rate, a0through a6and b0through b6are outputted. When the puncturing matrix (puncturing pattern) is applied to the coding value, a portion of 0 is deleted, and a portion of 1 remains according to the pattern of the puncturing matrix. Finally, a0, b0, b1, a2, a3, b3, b4, and a5are outputted.FIG. 8shows an example of a coding method, and the coding method of the present invention is not limited thereto.

The encoder162encodes the product information using the same method as described above.

Also, the encoder172performs a bit interleaving according to a burst error that may be generated during the data transmission. The bit interleaving is performed by reference bit unit on the overall data, for example, by 32-bit unit. That is, when there is data of about 60 bytes, the order thereof is mixed according to a certain rule by 4-byte unit.

For example, as described inFIG. 18, if data aaaabbbbccccddddeeeeffffgggg is bit-interleaved in the order of 0, 4, 8, 12, 16 and 20th data, and 1, 5, 9, 13, 17 and 21th data, the order of data is changed into abcdefgabcdefgabcdefgabcdefg. Although a portion of bits is lost in the course of transmitting the interleaved data, the order of data may become aa_abbbbccccdddde_eef_ffg_gg due to de-interleaving. Accordingly, data may be recovered using ambient bits.

FIG. 19is a diagram illustrating encoding of product information of a refrigerator and the configuration of a control signal according thereto.

As shown inFIG. 19A, the encoder162configures a packet with a plurality of frames.

The encoder162adds the product ID and version information to the product information that is diagnosis data. This is performed at an application layer.

In this case, the version information, which is a version of the smart diagnosis, relates to the smart diagnosis algorithm or the whole smart diagnosis system, and the version information of the smart diagnosis signifies protocol name information corresponding thereto. For example, as shown inFIG. 19B, when the version is expressed as 0x01, the protocol name signifies ‘Smart Diagnosis for Refrigerator v1.0’ The product ID is an identifier for identifying products, and the diagnosis data is product information for failure diagnosis of the refrigerator.

The version and the product ID are directly inputted into the control unit160. On the other hand, the diagnosis data, i.e., the product information is stored in the memory172or the storage unit174. Accordingly, if the smart diagnosis is executed, the control unit160loads data stored in the memory172and temporary data stored in the storage unit174as product information, that is, diagnosis data.

FIG. 20is a diagram illustrating the configuration and encoding of a control signal.

Referring toFIG. 20A, the encoder162partitions data including product ID and version information in addition to product information into certain units for framing. The encoder162utilizes Frame Check Sequence (FCS) to check an error by frame unit.

For example, when data of about 60 bytes is divided into 15-byte size, one frame includes about 15-byte data, and the packet includes about four frames. In this case, the number of frames may vary according to the division unit, and the number of frames constituting the packet may vary. The size of each frame may vary according to IFS, product information, and symbol time.

The encoder162, as shown inFIG. 20B, configures the frame with a header and a payload.

The header of the frame includes frame type representing the format of the frame, reserved, length, and FCS. The payload is a field including data in which the product ID and the version information are added to the product information.

The size of the frame type, reserved, and length is 1-byte, and the size of FCS is 1-byte. Accordingly, the header is assigned with total 2-byte. The payload is assigned with about 1 to 15-byte. In this case, 2-bit, 2-bit, and 4-bit are assigned to the frame type, reserved, and length, respectively.

The frame type represents the format and order of the frame. The information of the frame type is stored in the sixth and seventh bits of the header other than FCS. For example, the frame type 00 indicates that the frame is a starting portion of the packet. The frame type 01 indicates that the frame is a middle portion of the packet. The frame type 11 indicates the frame is a final portion of the packet.

Accordingly, when the service cent200collects the plurality of frames, the service center200may distinguish the order of the frame using the frame type.

The length represents the length of the payload including in the frame by unit of byte. Since the size of the payload ranges from 1 byte to 15 bytes, the length field is represented as 3-bit, information of which is included in the 0, 1, and 2th bit of the header other than FCS.

For example, when the value of the length is 001, it means that the payload has a size of 1-byte. When the value of the length is 101, it means that the payload has a size of 5-byte.

FCS is for detecting an error of the frame. FCS may utilize Cyclic Redundancy Check (CRC)-8 to check whether there is an error in the frame.

Reserved may include contents necessary for design. Reserved is represented in 4 and 5th bit in the header other than FCS.

The payload is partitioned from the data shown inFIG. 9A. When a packet of about 60 bytes is partitioned into four frame of about 15 bytes, each frame includes a payload of about 15 bytes. A frame header is added to such a payload to form one frame.

The encoder162performs FEC encoding on the frame to restore a bit error as described inFIG. 8, and complies with convolution coding and puncturing method, and performs interleaving.

Since a sound outputted through the sound output unit150may be damaged by background noise or interference in the course of transmission through the communication network, the frame is encoded by the above method to be changed into a FEC code.

The encoder162encodes the header and the payload with different code rate, as shown inFIG. 20C. The encoder162codes the header of 2-byte based on the ½ cord rate, and performs interleaving. The encoder162codes the payload of 1 to 15 bytes based on a ⅔ code rate, and performs interleaving. That is, the header is outputted as a symbol of 2-bit with respect to an input of 1-bit, and the payload is outputted as a symbol of 3-bit with respect to an input of 2-bit. In this case, an increase length is reduced through the puncturing using the puncturing matrix. The encoder162performs bit-interleaving by unit of 32-bit after coding, in order to deal with a burst error during the transmission.

Upon performance of FEC encoding, additional tail symbols are generated two times because the header and the payload are encoded, respectively. Such tail symbols may be removed during the puncturing or the interleaving, but a stuff is added to meet a certain number of bits.

Also, the encoder162adds preambles to the encoded header and payload. An Inter Frame Spaces (IFS) is added between the frames.

The preamble indicates that one frame starts, and may be formed in various patterns. For example, the pattern of the preamble may be formed to have a pattern 0x0FF0.

IFS is a section in which a signal is not outputted between frames.

Accordingly, the encoder162encodes the product information, and partitions it into frames to generate a control signal consisting of the frames. In this case, the control signal includes a plurality of symbols.

One frame includes the header, payload, preamble, and IFS, which include a plurality of symbols and have a certain size, respectively. In the frame, the preamble, header, tail symbol, the preamble is configures with 16 symbols, the header is configured with 32 symbols, the tail symbol of the header is configured with 4 symbols, the payload is configured with 12 through 180 symbols, the tail symbol of the payload is configured with 4 symbols, and IFS is configured with 16 symbols. The stuff varies according to the number of bits according to the encoding result or the result of the modulation result. That is, when the result of alignment of 32 bits is 31 bits, 1 bit is added to the stuff.

That is, one packet is partitioned in the plurality of frames, and the frames include preambles, headers, and payloads, respectively. IFS intervenes between frames. Accordingly, one frame includes about 84 to 252 symbols from the preamble to IFS, and further includes a stuff symbol.

As described above, the encoder162generates a control signal for outputting a sound, by performing encoding and framing, and adding the preamble and IFS. The modulator182may modulate the control signal encoded as described above and including a plurality of symbols by frame unit. The modulator150receives the encoded control signal and modulates it into a frequency signal. The frequency signal is applied to the sound output unit150to be outputted as a sound including the product information.

FIG. 21is a diagram illustrating Inter Frame Space (IFS) setting of a control signal.FIG. 21Ais a diagram illustrating a process of recognizing noise from a terminal, andFIG. 21Bis a diagram illustrating a frame including IFS to avoid a noise reduction like inFIG. 21.

Referring toFIG. 21A, a terminal81recognizes a varying signal like a first signal87among signals of audio frequency band as data, and recognizes a signal having a constant pattern in spite of time lapse like a second signal88as a noise.

The terminal81reduces a gain with respect to the second signal88recognized as a noise to transmit a waveform like a third signal89.

The terminal81may attenuate a signal by recognizing a sound outputted from the refrigerator1as a noise according to the above characteristics. Accordingly, the sound of the refrigerator1may not be delivered to the service center200, or may be distorted or lost during the transmission.

Accordingly, upon generation of the control signal as described inFIG. 21b, the encoder162of the refrigerator1partitions a packet into a plurality of frames, and sets IFS between frames such that the sound is not recognized as a noise in the terminal81. IFS is a section where a signal is not outputted between frames.

Since the terminal81recognizes the sound of the refrigerator1as a typical voice signal due to an interrupted sound of IFS before the sound is recognized as a noise, the sound may be provided to the service center200without signal attenuation.

The interrupted sound may be generated due to IFS before the terminal81recognizes a sound outputted from the refrigerator1as a noise, in consideration of time necessary for the terminal81to recognize the noise.

The terminal81determines that a sound signal is a noise when the sound signal of a certain frequency continues for about 2.5 seconds to about 6 seconds, and determines that a sound signal having the same frequency for about 10 seconds or more is a noise.

Accordingly, the encoder162may set the size of the frame and the symbol time such that an output time per frame falls within about 2.5 to about 3 seconds, and does not exceed about 10 seconds. Here, the time for one frame to be outputted as a sound may vary according to the symbol time, the number of frequencies that are used, and the size of the frame.

In this case, since the terminal81may consider a silent interval of a certain time as a temporary phenomenon, and may recognize it as a state where a signal is continuously inputted, IFS may be set such that the terminal81recognizes it as a silent interval.

As the size of the IFS section is reduced, a transmittable amount of signal per unit time (e.g., about 1 second) increases, but the terminal81may determine it as a noise. On the other hand, as the size of the IFS section increases, the terminal81is unlikely to recognize a sound signal as a noise, but a transmittable amount of signal per unit time (e.g., about 1 second) is reduced.

Accordingly, the IFS section may be set to have a value of about 0.1 second to about 1 second.

For example, when the IFS section is set as about 16 symbols as described above, and the symbol time of 1 symbol is about 12 ms, IFS has a value of about 192 ms.

FIG. 22is a diagram illustrating a frequency conversion of a modulator.

As described above, the frequency of the control signal encoded by the encoder162according to a certain method may be converted by the modulator182to be outputted as a sound through the sound output unit150.

It will be assumed that the modulator182uses a Frequency-Shift Keying (FSK), and uses two frequencies of about 2.6 kHz and about 2.8 kHz. The modulator182allows the frequency of about 2.6 kHz to be outputted in response to a logic value 0, and allows the frequency of about 2.8 kHz to be outputted in response to a logic value 1.

When the control signal is 010, the modulator182converts a first bit11having a value of 0 into a signal21having a frequency of about 2.6 kHz, and converts a second bit12having a value of 1 into a signal22having a frequency of about 2.8 kHz. Also, the modulator182converts a third bit13having a value of 0 into a signal23having a frequency of about 2.6 kHz.

In this case, assuming that bits of the control signal denote one symbol, respectively, the length of the symbol denotes a symbol time, and one frequency signal is outputted in response to one symbol, the length of the basic unit of the frequency signal constituting the outputted sound may become the symbol time.

FIG. 23is a diagram illustrating a dead time.

Referring toFIG. 23, the encoder162sets a dead time in the course of encoding the product information, and upon signal conversion, the modulator182switches off a resonant frequency for the frequency conversion in a section where the dead time is set, and stops the signal conversion.

This is for removing a reverb effect that affects a next signal conversion due to the principle of charging and discharging of a capacitor. In a section where a value is changed due to the reverb effect, two frequencies may be shown, and an unnecessary signal may be added to the sound signal. Alternatively, this is because an influence according to a change from one frequency signal to another frequency signal while a data value is being changed may remain and continue beyond a specified time.

Here, IFS is set between frames, whereas the dead time is set by symbol unit of the control signal.

Upon signal conversion, the control signal as shown inFIG. 23Adoes not suddenly change, but gradually change in a section where a value changes from 0 to 1 or vice versa as shown inFIG. 23B.

Particularly, when the value changes from 1 to 0 (12and13), the preceding signal value affects the following signal13. Accordingly, a dead time is set based on a symbol. For example, the dead time per symbol is set according to 1-bit of the control signal, that is, one symbol. However, when the value is not changed but maintained, the dead time may not be set. That is, only when the value is changed, the dead time may be set.

Since the signal value gradually changes, the dead time17is set in the symbol time. In this case, if the dead time is too long, symbol recognition rate is reduced, and if the dead time is too short, the preceding signal affects the following signal. Accordingly, the dead time has to be set according to the size of the symbol, i.e., the symbol time.

When the dead time is set in the control signal, the modulator182stops modulating a signal in a section where the dead time is set. In this case, when the signal is modulated using Pulse-Width Modulation (PWM), the modulator182switches off a resonant frequency for modulation in the section where the dead time is set to temporarily stop the frequency signal modulation for the dead time. Accordingly, a sound outputted from the sound output unit150is outputted in a state where a reverb effect between symbols is removed.

FIG. 24is a diagram illustrating an exemplary output signal form when a signal is converted without a dead time.

As shown inFIG. 24A, upon control signal conversion of the modulator182, when a control signal is converted into a certain frequency signal without a dead time, a frequency by PWM is generated together with a synchronous signal41for synchronization of signal conversion.

In this case, frequencies as many as the number of frequency used in the frequency conversion are generated from a frequency oscillator. Output signals from the respective frequencies are combined to be outputted as one sound through the sound output unit150.

The modulator182modulates the control signal by a frequency conversion method. The modulated signal is shown as a spectrum43for convenience of explanation. That is, when the control signal is converted into a sound signal without a dead time as described above, the signal becomes longer than the symbol time at the corresponding section, generating an error45affecting the following symbol time.

This may be applied to the case where a signal is converted in the service center200, as well as the case where a sound is outputted from the refrigerator1. In this case, reverberation in a section where a data bit changes affects the following symbol.

FIG. 25is a diagram illustrating an exemplary signal form when a sound signal of a control signal is converted by applying a dead time in a refrigerator.

Upon signal conversion using a synchronous signal51and a resonant frequency52, the modulator182stops the resonant frequency by PWM in a section where a dead time is set, according to the control signal of the control unit160(54).

As shown inFIG. 25A, if an oscillation frequency switches off in a dead time section17(54), a converted signal is generated in a specified symbol time section (55).

When the control signal set with a dead time as described above is converted into a sound signal, as shown inFIG. 25B, the signal is converted in the size of the symbol time.

The generated sound signal is applied to the sound output unit150to be outputted as a certain sound.

In this case, the symbol time is determined as follows.

FIG. 26is a diagram illustrating a sound structure as an example of symbol time setting in a refrigerator.

Referring toFIG. 26, by the frequency conversion of the modulator182, the sound output unit150outputs a sound that is a combination of at least two frequency signals. It will be assumed that frequencies of about 2.6 kHz and about 2.8 kHz are used.

In this case, the frequency of the outputted sound may change according to available frequency band of the sound output unit150. If the frequency response of the sound output unit150is higher or lower than about 2.6 kHz or about 2.8 kHz, the frequency of a pulse constituting the sound signal may also become higher or lower.

The symbol is the data unit constituting the control signal. When one frequency signal is outputted according to one symbol, a sound outputted from the sound output unit150bmay be used as a basic unit representing a piece of information. That is, one symbol may correspond to one frequency signal in the outputted sound. However, the number of symbols corresponding to the frequency signals may vary according to the number of frequencies used in the modulator182.

The frequency signal outputted according to the symbol includes a plurality of pulses. The period of each pulse is determined according to the frequency used in the modulator182.

When a sound signal is outputted as a sound to be transmitted through a telephone network or a mobile communication network, the data transmission rate vary according to the size of the symbol. When the symbol time is about 30 ms, it takes about 30 seconds to transmit data of about 100 bytes.

Accordingly, the size of the symbol, the symbol time has to be reduced to increase the transmission rate. This means that the number of pulses in each frequency signal outputted according to the symbol is reduced.

Assuming that the basic unit of the frequency signal of the outputted sound is a symbol, when each symbol is converted to be replayed at an audio frequency range, the replay time becomes short. Accordingly, a sound may not be exactly outputted from the sound output unit150, and an outputted sound may be attenuated or distorted in the course of transmission through a telephone network or a mobile communication network. This may cause diagnosis impossibility or wrong diagnosis upon refrigerator diagnosis of the service center200using a sound.

Accordingly, the symbol time may be set by determining the number of pulses included in one frequency signal outputted according to one symbol, so that the size of data regarding a sound and the transmission rate according thereto can be reduced, and exact output and transmission of the sound can be achieved.

The symbol size, i.e., symbol time is set by considering whether a certain sound can be actually outputted and whether transmission through a communication network is possible, as well as the total length of the control signal to be outputted as a sound, the total length of an outputted sound, and the transmission rate. The dead time and IFS may be determined according to the symbol time that is set.

Particularly, since the output of a sound from the sound output unit150and transmission through a communication network are affected by the number of pulses in a symbol, the symbol time may be set in consideration of the number of pulses per symbol and the frequency components that are used.

As described above, when the symbol time becomes smaller, the replay time of the symbol at the sound output unit150becomes extremely short, causing problems with the output and recognition of the sound. On the other hand, when the number of the pulses per symbol and the size of the symbol increase, the recognition of the sound is facilitated, but the transmission time of the outputted sound including the product information increases. Accordingly, the size of the symbol, i.e., the symbol time may be determined within a recognizable range according to the characteristics of a telephone, mobile terminal, telephone network, and mobile communication network.

The period of the pulse constituting the frequency signal corresponding to the symbol is determined by the frequency response of the sound output unit150, for example, about 2.6 kHz and about 2.8 kHz. Accordingly, the number of pulses disposed at the same time slot with respect to the same frequency is constant. In this case, since a portable terminal receiving a signal of an audio frequency range receives a sound signal, and then performs sampling, the size of the symbol must not be reduced below a certain level.

Accordingly, the number of pulses per symbol is allowed to be about eight or more, and the symbol time is allowed to be about 3 ms or more.

The number of pulses per symbol may range from about 8 to about 67.

One symbol including about 8 to about 32 pulses may have few errors and realize the highest transmission rate when the refrigerator1transmits data to the portable terminal81using a sound signal.

When the symbol time is shorter than about 7 ms, a recognition error may occur in that the portable terminal81can not exactly obtain a replayed sound of the sound output unit150. When the symbol time exceeds about 24 ms, the transmission rate of a sound signal transmitted from the refrigerator1to the portable terminal81is reduced.

FIG. 27is a diagram illustrating a relation between an error rate and a transmission rate according to a change of the size of a symbol time in a refrigerator.

As described above, the time necessary to output a sound and the transmission rate of the outputted sound through a communication network vary according to the symbol time.

Referring toFIG. 27, when the sound outputted from the refrigerator is transmitted to the service center through a portable terminal, if the symbol time varies from about 12 ms to about 30 ms while satisfying a certain error rate, the transmission rate varies. InFIG. 27, the horizontal axis indicates symbol time, and the vertical axis indicates transmission rate. Also, the, inversely proportional curve90indicates error rate. In this case, the error rate curve90denotes an error rate in which an error of about 30 bits occurs per 1216 bits.

As the symbol time increases, the size of data to be transmitted increases. Accordingly, the transmission time varies, and the transmission error rate varies according to the increase of the transmission time.

When the symbol time is about 21 ms and 24 ms, the transmission rate is reduced to about 7 and 8, respectively. When the symbol time is about 15 ms, the transmission rate is highest, about 24, but the error rate is beyond about 30/1216 bits, with the error rate condition unsatisfied.

When the symbol time is about 12 ms and 15 ms, the transmission rate is high, but an error rate at the symbol time of about 15 ms increases. Accordingly, it is desirable to set the symbol time to about 12 ms in which the error rate is relatively low and the transmission rate is high.

Accordingly, the number of pulses per symbol may be set to at least eight or more, and the symbol time may be set within a range of about 3 ms to about 24 ms.

In this case, in consideration of the recognition rate, the symbol time may be set within a range of about 7 ms to about 24 ms. In addition, considering the error rate and the transmission rate, the symbol time may be set to about 12 ms.

FIG. 28is a diagram illustrating a frame and an error check code of the frame in processing a sound including product information of a refrigerator.

The product information of the refrigerator is framed to be modulated including a preamble and an error check and is outputted as a sound to be transmitted to the service center200.

In this case, the service center performs an inverse conversion and decoding on the received sound to extract the product information therefrom. It is possible to distinguish the frames using the preamble, and determine whether the frame is normal or abnormal through error check.

The diagnostic server of the service center checks whether an error exists in each frame. In this case, the error check may be performed using Cyclic Redundancy Check (CRC), parity check method, checksum method, and Adler-32 algorithm.

The server control unit210of the diagnostic server determines whether an erroneous frame exists. If there is no erroneous frame, the product information may be extracted through the signal processing unit230, and the diagnosis unit260performs failure diagnosis on the refrigerator.

When there is an erroneous frame among the received frames, the server control unit210may temporarily store the received frame, and may request re-transmission from the refrigerator.

In this case, since the server control unit210, as described above, can know the order of the erroneous frame due to the frame type included in the frame, the failure diagnosis is performed by comparing a plurality of frames31, which are primarily transmitted and temporarily stored, with a plurality of frames32that are secondarily transmitted, respectively, and combining normal frames. Also, the server control unit210may request re-transmission of only erroneous frames35and27, not all frames.

FIG. 29is a flowchart illustrating a signal output method of a refrigerator according to an embodiment of the present invention.

Referring toFIG. 29, the refrigerator operates according to setting inputted through a manipulator144(S110). In this case, the setting information on the operation of the refrigerator is stored as operation information.

If an error occurs during the operation (S320), the control unit160stores error occurrence information according to a malfunction of the refrigerator as failure information. Here, the failure information and the operation information are stored in the memory172as product information (S330).

The control unit160outputs the error on the display unit141. If entrance into smart diagnostic mode is selected by the selector145(S350), the control unit160fetches the product information including the failure information and the operation information from the memory172(S360), and generates the product information as a control signal of a certain format.

The control unit160applies the generated control signal to the modulator182, and applies a control command to the sound output unit150such that the sound output unit150operates.

In this case, the control unit160sets a dead time in a section where data values of the product information change, that is, a section between symbols, and the modulator182modulates the control signal including the product information into a sound signal of a certain frequency band in consideration of the dead time (S370).

The sound output unit150receives the outputted sound signal that is modulated by the modulator182, and output a certain sound (S380).

FIG. 30is a flowchart illustrating a signal conversion method of a refrigerator according to an embodiment of the present invention.

As described above, when the refrigerator outputs a certain sound, a process of generating a control signal including the product information, and converting the control signal into a sound signal to be outputted as a sound is as follows. It will be described as an example that the modulator182modulates a signal according to Frequency-Shift Keying (FSK), but embodiments are not limited thereto.

Referring toFIG. 30, if the control unit160fetches the product information from the memory172(S410), the control unit160, as described above, sets a dead time according to data values of the product information.

The control unit160divides the product information into certain sizes, or combines them, and sets the dead time between symbols to generate a control signal of a certain format.

In this case, the modulator182modulates the control signal into a sound signal of a certain frequency band. In a section of the control signal where the dead time is set (S420), the signal conversion temporarily stops (S430). After the dead time section is passed, the signal conversion resumes.

If a data value of the control signal is 0 (S440), the modulator182performs signal conversion into a first frequency (S450). If the data value of the control signal is 1 (S460), the modulator182performs signal conversion into a second frequency (S470). That is, when the data value is 0, the modulator182converts the control signal into a signal having a frequency of about 2.6 kHz. When the data value is 1, the modulator182converts the control signal into a signal having a frequency of about 2.8 kHz. In a dead time section where the data value changes, the signal conversion temporarily stops.

In this case, a resonant frequency signal of PWM switches off to stop the signal conversion in the dead time section. If the resonant frequency switches off in the dead time section, a sound signal is formed in the symbol time in spite of an influence of a reverberation signal according to the characteristics of a capacitor.

Upon signal conversion, the modulator182modulates the signal by unit of symbol time, based on the symbol time that is a unit time in which the product information has one data value.

If the signal conversion is performed by unit of symbol time as described above (S420through S470), and is completed with respect to the product information (S480), each signal converted by unit of symbol time is outputted as a sound signal.

The sound output unit150receives the sound signal from the modulator182, and outputs a certain sound (S490).

Accordingly, a user hears the sound including the product information of the refrigerator, and transmits the sound to the service center through a communication network to which the user is connected, as described inFIGS. 1 and 2.

A refrigerator and a signal output method thereof according to an embodiment of the present invention can prevent signal noise and distortion in a section where a data value changes, and can achieve efficient signal processing, by setting a dead time between symbols of a control signal including product information to stop signal conversion in the dead time section, in outputting the product information including operation information such as failure information generated during the operation of the refrigerator and setting information for the operation of the refrigerator.

Also, stable output and transmission of the sound can be achieved, and the transmission rate can be improved, by setting the dead time in consideration of the number of pulses per symbol in a sound signal, in generating the control signal.

FIG. 31is a magnified view of a hinge unit shown inFIG. 3.FIG. 32is a perspective view illustrating an internal configuration of the hinge unit ofFIG. 31.FIG. 33is a diagram illustrating the inside of a housing of a hinge unit to explain a structure in which a sub PCB is seated on the hinge unit

Referring toFIGS. 31 through 33, the hinge unit allows the refrigeration compartment doors121and122of the refrigerator1to be pivotably connected to the case110. The hinge unit may include a hinge unit302connecting the left refrigeration compartment door121to the case110, and a hinge unit300connecting the right refrigeration compartment door122to the case110. Since the hinge unit302connected to the left refrigeration compartment door121has the same structure as the hinge unit300connected to the right refrigeration compartment door122, only the hinge unit300connected to the right refrigeration compartment door122will be described herein.

The hinge unit300is provided on the right top surface of the case110to allow the right refrigeration compartment door122to be opened and closed. Also, a door switch320is provided in the hinge unit300. The door switch320turns on/off a lamp (not shown) lighting the refrigeration compartment120by being contacted when the right refrigeration compartment door122is opened and closed. The door switch320switches off the lamp when the right refrigeration compartment door122is closed, and turns on the lamp when the right refrigeration compartment door122is opened.

The hinge unit300includes a hinge housing310defining the external appearance thereof. The hinge housing310has a pivot insertion portion311into which a pivot (not shown) of the refrigeration compartment door122is inserted, and a coupling mount314having a coupling hole through which coupling members such as a screw and a bolt penetrate. The coupling member penetrates the coupling hole315to be coupled to the case110.

Also, the hinge house310has a door switch coupling hole316to which the door switch320may be coupled. The door switch320includes a door switch connector321and a switching member322. The door switch connector321is inserted into the door switch coupling hole316to be fixed. The switching member322retracts into the inside of the door switch connector321by a pushing force of the right refrigeration compartment door122when the right refrigeration compartment door122is closed, and elastically protrudes out of the door switch connector321by removal of the pushing force of the right refrigeration compartment door122when the right refrigeration compartment door122is opened.

The door switch connector321is electrically connected to the control unit160and the switching member322to allow the control unit160to sense whether the refrigeration compartment120is opened or closed according to the switching operation of the switching member322.

An sound output unit is provided in the hinge housing310for outputting the product information as a sound upon smart diagnostic mode. The sound output unit may include one of a buzzer and a speaker. Hereinafter, it will be assumed that the sound output unit is a buzzer352.

A Printed Circuit Board (PCB)362is fixed in the hinge housing310. The buzzer352is mounted on the PCB362. To this end, support members332a,332b,332cand332dfor supporting the PCB362and fixing members331aand331bfor fixing the PCB362on the support members332a,332b,332cand332dare provided in the hinge housing310.

Particularly, considering the hinge housing310is shown upside down inFIGS. 32 and 33, the PCB362seems to be suspended by the fixing members331aand331bin the hinge housing310when the hinge housing310is coupled to the case110. Accordingly, the PCB362is spaced from the surface of the case110, so that the PCB362can be protected from water condensing or permeating on the case110.

On the other hand, in a state where the PCB362is spaced from the surface of the case110, the buzzer352may be mounted on the PCB while being also spaced from the surface of the case110. As described above, the buzzer can also be protected from water gathering in the hinge housing310.

A sound output hole312, which is a passage of a signal sound outputted from the buzzer352, is formed in the hinge housing310. The sound output hole312may be formed in an output direction of the buzzer352to minimize the attenuation of the signal sound. The buzzer352shown inFIG. 32is formed to have a substantially cylindrical shape, and is mounted to extend from the PCB362in a longitudinal direction. The buzzer352may output a sound in a radial direction through an output terminal provided on the outer circumference of the cylindrical shape thereof.

The sound output hole312is formed by cutting an edge portion of the hinge house310. When the hinge housing310is coupled to the case110, a hole is formed between the hinge housing310and the surface of the case110. As described above, since the sound output hole312is formed at the edge of the hinge housing310, water gathering in the hinge housing310may smoothly flow out through the sound output hole312.

Also, the sound output hole312may be opened in the forward direction of the refrigerator1. Considering the refrigerator may be installed in a house by a built-in method, if the sound output hole312is opened in the lateral or backward of the refrigerator1, it is inconvenient for a user to place a portable terminal close to the sound output hole312.

Since the refrigerator1can be installed by a built-in method as well as a stand-alone method, in either case, the sound output hole312may be opened in the forward direction of the refrigerator1to allow a user to conveniently perform smart diagnosis.

The refrigerator may include various types of refrigeration compartments and freezer compartment. Door for opening and closing the refrigeration compartment and the freezer compartment may also be configured by various methods. For example, the case may be partitioned into upper and lower sides. One side may be provided with a refrigeration compartment, and the other side may be provided with a freezer compartment. In this case, two doors may be vertically provided on the case to open and close the refrigeration compartment and the freezer compartment, respectively.

Otherwise, the case may be partitioned into right and left sides. One side may be provided with a refrigeration compartment, and the other side may be provided with a freezer compartment. In this case, two doors may be horizontally provided on the case to open and close the refrigeration compartment and the freezer compartment, respectively.

Also, as described in the present embodiment, the case110may be vertically partitioned into upper and lower sides. One is provided with the refrigeration compartment120, and the other is provided with the freezer compartment130. The refrigerator1may be a three-door type in which two refrigeration compartment doors121and122are provided on the right and left sides of the case110to open and close the refrigeration compartment120, and one freezer compartment door131of a sliding type is provided to open and close the freezer compartment130. Also, the refrigerator1may be a four-door type in which an additional door of a sliding type is further provided based on the three-door type.

The hinge unit according to an embodiment of the present invention may be applied to any type of refrigerators described above. Space opened and closed by a door using the hinge unit is not limited to a refrigeration compartment as described in the present invention. The hinge unit may be applied to various types of the above refrigerator doors, in consideration of the arrangement of a refrigeration compartment and a freezer compartment, and the configuration of doors for opening and closing the refrigeration compartment and the freezer compartment.

Referring toFIGS. 3 and 4, the front surface of the hinge unit300is covered by the right refrigeration compartment door122in a state where the right refrigeration compartment door122is closed. Accordingly, an entire esthetic feeling on the appearance of the product can be improved, and foreign substances such as dust and water can be prevented from entering the sound output hole312in the front side of the hinge unit300.

FIG. 34is a diagram illustrating a control panel shown inFIG. 3.

Referring toFIGS. 31 through 34, entrance into smart diagnostic mode of a refrigerator according to an embodiment of the present invention will be described.

Referring toFIG. 34, as described with reference toFIG. 3, the control panel140includes a display unit141for visually displaying various state information of the refrigerator1, and the input unit142for receiving various control commands from a user.

The input unit142may include various manipulation keys for performing functions set by the manipulation of a user. For example, the input unit142may include an ice plus button142afor increasing the amount of ice that can be made in the ice maker, a dispenser button142bfor selecting one of ice cube, water, or crushed ice provided from the dispenser125, a freezer button142cfor setting the temperature of the freezer compartment, a refrigerator button142dfor setting the temperature of the refrigeration compartment, a light/filter button143efor control the operation of a lamp (not shown) provided on the dispenser125or initializing a filter replacement-indicating lamp (not shown) after a filter is replaced, and an alarm/lock button142ffor setting an alarm for door opening or locking the manipulation keys.

The refrigerator1according to the present embodiment enters smart diagnostic mode by a combination of the above manipulation keys, not a separate selection key for the smart diagnosis. For example, when a user opens the right refrigeration compartment door122, locks the manipulation keys by pushing the alarm/lock button142f, and pushes the freezer button142cfor a predetermined duration (e.g. 3 seconds), the smart diagnosis may be performed, and a sound including product information may be outputted through the buzzer352.

Since the smart diagnosis can be performed by a combination of the manipulation keys provided in the control panel without a separate selection key for the smart diagnosis, it is not necessary to include a selection key that is less frequently used. Accordingly, manufacturing cost can be saved, and the smart diagnosis can be performed only when the intention of a user to enter smart diagnostic mode is clear.

In the present embodiment, since the control panel140is provided on the left refrigeration compartment door121, entrance into smart diagnostic mode is premised on the assumption that the right refrigeration compartment door122is opened. Accordingly, when a user opens the right refrigeration compartment door122, and then manipulates the manipulation buttons provided in the control panel140in a state where the left refrigeration compartment door121is closed, the refrigerator1may enter smart diagnostic mode. Accordingly, the usability can be improved.

FIG. 35is a diagram illustrating an exemplary buzzer output configuration provided in a refrigerator according to an embodiment of the present invention.

Referring toFIG. 35, the refrigerator1according to the present embodiment includes a first PCB360mounted with a main controller161constituting a control unit160, a second PCB370mounted with a first buzzer371for outputting a signal sound including product information, and a third PCB380mounted with an I/O control unit143.

The first PCB360includes the main controller161for controlling overall operations of the refrigerator1, and a sensing unit190for processing sensed information. The first PCB360may be usually provided in the case110.

The second PCB370is mounted with the first buzzer371outputting a signal sound including the product information, and is fixed in the hinge housing310as described with reference toFIGS. 31 through 33.

The third PCB380is mounted with an I/O control unit143, the input unit142, and a second buzzer382. The second buzzer382outputs sounds such as alarm sounds, input sounds, and/or warning sounds that include various operation information directly recognizable by a user in addition to failure information. The third PCB380may be provided in the left refrigeration compartment door121on which the control panel140is provided.

The above configuration has an advantage in entrance into smart diagnostic mode through operations of the manipulation keys provided in the control panel140and output of a sound including the product information through the buzzer371provided in the refrigeration compartment door122.

FIG. 36is a diagram illustrating another exemplary buzzer output configuration provided in a refrigerator according to an embodiment of the present invention.

Referring toFIG. 36, the refrigerator1according to the present embodiment includes a first PCB460mounted with a main controller161and a sensing unit190, and a second PCB470mounted with a first buzzer471outputting a signal sound including product information and a selector145for entering smart diagnostic mode. The first PCB is usually provided in the case110.

The second PCB470, which is mounted with the first buzzer471outputting a signal sound including the product information, is fixed in the hinge housing310as described with reference toFIGS. 31 through 33.

Accordingly, in order to enter smart diagnostic mode in the configuration as shown innFIG. 36, when a smart diagnostic mode entrance signal is applied to the selector145mounted in the second PCB470, the applied signal is sensed by the main controller161, and the smart diagnosis is performed.

The above configuration has an advantage compared to a configuration in which a separate selection key is provided to perform smart diagnosis. Hereinafter, an exemplary configuration in which a separate selection key is provided on the hinge unit300will be described in detail with reference to the accompanying drawing.

FIG. 37is a diagram illustrating another exemplary hinge unit applicable to a refrigerator according to an embodiment of the present invention.

Hereinafter, the hinge unit shown inFIG. 37is configured similarly to that described with reference toFIGS. 31 through 33, but has a difference in that a selection switch473is provided on a hinge housing410for entrance into smart diagnostic mode. The selection switch473may be implemented with various types of switches including push switch, toggle switch, slide switch, touch switch, and so forth. In the present embodiment, it will be assumed that the selection switch473is configured with a tact switch in consideration of manufacturing cost and operability.

Entrance into smart diagnostic mode is performed when a user manipulates the selection switch473provided in the hinge housing410. In this case, the flow of a signal is similar to those described with reference toFIG. 36. Such a configuration has an effect of improving usability in that smart diagnosis can be easily performed by manipulation of the selection switch473that is separately provided.

FIG. 38is a magnified view illustrating a portion of the refrigerator ofFIG. 3in which a dispenser and a control panel are provided, and illustrates an exemplary sound passage configuration for the output of a signal sound.

Referring toFIG. 38, a buzzer71outputting a signal sound including product information and a PCB80mounted with the buzzer71are provided in left refrigeration compartment door121. In this case, a sound passage may be formed in the left refrigeration compartment door121to pass a signal sound outputted from the buzzer71. The signal sound outputted from the buzzer71may be outputted to the outside of the refrigerator1with signal attenuation minimized.

In the present embodiment, a frame126in which a dispenser125and a control panel140are mounted may be mounted in the left refrigeration compartment door121. In this case, a gap between the frame126and the left refrigeration compartment door121may serve as a sound passage. The buzzer7may be provided to face the gap between the frame126and the left refrigeration compartment door121and output the signal sound.

The configuration as shown inFIG. 38has an advantage of using a gap formed by the structural feature of the refrigerator1as a sound passage without forming a separate sound passage for the output of the signal sound. Also, since the signal sound is outputted near the control panel140, a movement distance of a user becomes shorter when a user places a terminal such as a mobile phone close to the control panel140after the refrigerator1enters smart diagnostic mode by manipulating manipulation keys of the control panel140.

FIG. 39is a magnified view illustrating a portion of the refrigerator ofFIG. 3in which a dispenser and a control panel are provided, and illustrates another exemplary sound passage configuration for the output of a signal sound.

Referring toFIG. 39, the configuration of the sound passage ofFIG. 39is similar to that ofFIG. 38except that a buzzer71is disposed to face a gap between a frame126and a control panel140. Accordingly, a detailed description thereof will be omitted herein.

FIG. 40is a diagram illustrating a door panel constituting a left refrigeration compartment door shown inFIG. 3.

Referring toFIG. 40, a door panel127defines the exterior of a left refrigeration compartment door121, and is attached to a left refrigeration compartment door frame (not shown) formed of plastic molding by an adhesive member such as Pressure Sensitive Adhesives (PSA) and double-sided tapes. Recently, in order to improve esthetic feeling or cubic effect, door panels formed of transparent or translucent materials are being widely uses. Particularly, when an input unit142of a control panel140is implemented as a touch type, the door panel127may be attached to the whole surface of the door including the input unit142.

As described above, when a buzzer71is disposed inside the refrigeration compartment door121, a sound passage may be separately formed to pass a signal sound including product information, outputted from the buzzer71. A hole72is formed in the door panel127shown inFIG. 40to serve as a sound passage. A hole may also be formed in a door frame according to the hole72in the door panel127, so that a signal sound outputted from the buzzer71may be outputted to the outside of the refrigerator1while the signal attenuation is minimized. Also, the buzzer71may be disposed such that the output direction of the signal sound faces the hole72as described in the previous embodiments.