KR101588830B1 - A cooking apparatus using microwave - Google Patents

Abstract

The present invention relates to a microwave-assisted cooking appliance. The microwave cooker according to the present invention includes a controller for outputting a center frequency control signal, a noise generator for outputting a noise signal, an adder for adding a center frequency control signal and a noise signal, And a microwave generating unit for generating and outputting a plurality of microwaves having different frequencies within the frequency coverage. Thus, it is possible to scan the heating efficiency for all the frequencies within the coverage set within a scan period quickly.

Cooking equipment, microwave, noise signal, center frequency, sweep

Description

[0001] The present invention relates to a cooking apparatus using microwave,

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a microwave-assisted cooking device, and more particularly, to a microwave-assisted cooking device capable of rapidly scanning a heating efficiency for each frequency.

Generally, a microwave cooker receives food and closes it. When the operation button is pressed, a voltage is applied to the high-voltage generator, and a commercial voltage applied to the high-voltage generator is boosted to supply power to the magnetron generating microwaves And the microwave generated by the magnetron is transmitted to the cavity through a waveguide or the like.

In this case, the microwave cooker is used to heat the food by frictional heat generated by vibrating the molecules constituting the food by 2.45 billion times per second by irradiating the microwave generated from the magnetron to the food.

In addition, microwave-assisted cooking machines are capable of uniform temperature control, uniform heating of foods of various sizes and shapes due to simultaneous heat generation at each part of the food, various advantages such as saving cooking time and convenience of operation It is widely distributed in general households.

1 is a diagram showing a general sweep frequency. Referring to FIG. 1, in the microwave cooking process, the frequency oscillator sequentially generates discrete single frequencies f1, f2, f3, and f4 as shown in FIG.

Therefore, it is impossible to continuously scan within the set frequency range, and a frequency sweep unit is determined by the minimum resolution ([Delta] f) for distinguishing the frequency control signals applied to the frequency oscillation unit.

Accordingly, there is a problem that it is difficult to scan the frequency between the frequency and the frequency, and it is difficult to measure the heating efficiency. In addition, there is a problem that the processing speed is slowed down by increasing a discrete single frequency that occurs sequentially for precise scanning.

An object of the present invention is to provide a microwave-assisted cooking device capable of scanning heating efficiency for all frequencies within a set coverage within a scan period.

According to an aspect of the present invention, there is provided a microwave cooker including a controller for outputting a center frequency control signal, a noise generator for outputting a noise signal, an adder for adding the center frequency control signal and the noise signal, And a microwave generator for generating and outputting a plurality of microwaves having different frequencies within the center frequency coverage based on the summed signals.

The microwave generator generates a microwave on the basis of the sum signal in the scan period during the cooking process using the microwave including the scan period and the heating period.

The microwave generating unit generates microwaves more precisely than the frequency intervals of the microwaves oscillating in the scan period and outputs the frequency intervals of the microwaves oscillated in the heating period.

According to another aspect of the present invention, there is provided a method of controlling a microwave cooker, including the steps of outputting a center frequency control signal, outputting a noise signal, summing the center frequency control signal and the noise signal, And generating a plurality of microwaves having different frequencies within the center frequency coverage during a scan period based on the sum signal and outputting the generated microwaves as a cavity.

According to the present invention, it is possible to scan the heating efficiency for all the frequencies within the coverage set within a scan period in a short time.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 2 is a partial perspective view of a microwave oven according to an embodiment of the present invention, and FIG. 3 is a cross-sectional view of the cooking apparatus of FIG.

The microwave cooker 100 according to the embodiment of the present invention includes a door 106 having a cooking window 104 attached to a front portion of a main body 102, And the operation panel 108 is coupled to one side of the front surface of the main body 102.

The door 106 opens and closes the cavity 134. Although not shown in the drawing, a filter unit (not shown) for shielding microwaves may be provided inside the door 106. [

The operation panel 108 includes an operation portion 107 for operating the operation of the cooking appliance and a display portion 105 for displaying the operation of the cooking appliance and the like.

The interior of the body 102 is provided with a cavity 134 having a receiving space of a predetermined size so that the object to be heated 140, for example, food is received and cooked by microwaves.

A microwave generator 110 for generating a microwave is installed on the outer surface of the cavity 134. A microwave generated by the microwave generator 110 is supplied to the output side of the microwave generator 110, And a microwave transfer unit 112 for guiding the microwaves to the inside of the cavity 134 are disposed.

The microwave generator 110 may include a magnetron or a solid state power amplifier (SSPA) using a semiconductor. The solid state power amplifier (SSPA) has the advantage of occupying less space than the magnetron.

On the other hand, the solid state power amplifier (SSPA) includes a hybrid microwave integrated circuit (HMIC) having separate passive elements (capacitors and inductors) and active elements (transistors, etc.) The active devices can be implemented as monolithic microwave integrated circuits (MMICs) implemented as a single substrate.

Meanwhile, according to the embodiment of the present invention, the microwave generating unit 110 can generate and output a plurality of microwaves. The frequency range of such microwaves may be in the vicinity of approximately 900 MHz to 2500 Hz. In particular, it may be within a predetermined range around 915 MHz or within a predetermined range around 2450 MHz. The microwave generating unit 110 will be described in detail below with reference to FIG.

The microwave transmitter 112 transmits the microwave generated by the microwave generator 110 to the cavity 134. The microwave transmitting unit 112 may include a waveguide or a coaxial line. In order to transmit the generated microwave to the microwave transmitting unit 112, a feeder 142 may be connected as shown in the figure.

The microwave transmitting unit 112 may be formed as an opening having an opening 145 in the cavity 134 as shown in the drawing. However, the present invention is not limited to this, and an antenna may be coupled to the end Do. The opening 145 may be formed in various shapes such as a slot shape. Through the opening 145 or the antenna, the microwave is emitted into the cavity 134.

Although the opening 145 is shown as being disposed on the upper side of the cavity 134, the opening 145 may be disposed on the lower side or the side of the cavity 134, and a plurality of openings may be disposed It is also possible. The same applies to the case where they are coupled through the antenna instead of the opening 145.

A power supply 114 is provided below the microwave generator 110 to supply power to the microwave generator 110.

The power supply 114 may include a high voltage transformer that boosts the power supplied to the cooking appliance 100 to a high voltage and supplies the power to the microwave generator 110, And an inverter for supplying a high output voltage of about 3500 V or more to the microwave generator 110.

A cooling fan (not shown) for cooling the microwave generator 110 may be installed around the microwave generator 110.

Although not shown in the drawing, a turntable (not shown) for rotating the heating object 140 may be installed inside the cavity 134. Inside the cavity 134, A stirrer fan (not shown) may be created, and a cover (not shown) may be provided to prevent damage to the stirrer fan (not shown). The stuttering fan (not shown) can be regarded as a kind of the above-mentioned antenna.

The above microwave cooking apparatus 100 is configured such that the user opens the door 106 and puts the heating object 140 in the cavity 134 and then moves the operation panel 108 ), Particularly, by operating the operation unit 107 and pressing the cooking selection button (not shown) and the start button (not shown).

That is, the power supply unit 114 in the cooking apparatus 100 boosts the input AC power to a high-voltage DC power and supplies the boosted power to the microwave generation unit 110. The microwave generation unit 110 generates the corresponding microwave And the microwave transmitting unit 112 transmits the generated microwave to the cavity 134 to emit the generated microwave. As a result, the heating object 140, for example, the food inside the cavity 134 is heated. The overall operation of the cooking apparatus 100 can be performed by a control unit (not shown). The control unit (not shown) will be described with reference to the following drawings.

FIG. 4 is a block diagram schematically showing the inside of the cooking apparatus of FIG. 1; 5 is a diagram illustrating a frequency used in a scan period.

Referring to the drawings, a cooking apparatus 100 according to an embodiment of the present invention includes a microwave generation unit 110 and a control unit 310. Further, the cooking apparatus 100 may further include a microwave transmitting unit 112.

The microwave generating unit 110 includes a frequency oscillating unit 332, a level adjusting unit 334, and an amplifying unit 336. The microwave generating unit 110 may further include a directional coupler 338.

The frequency oscillating unit 332 oscillates in accordance with the frequency control signal from the control unit 310 to output a microwave of the corresponding frequency. The frequency oscillator 322 may include a voltage controlled oscillator (VCO). The voltage control oscillator (VCO) oscillates at a frequency corresponding to the voltage level of the frequency control signal. For example, the greater the voltage level of the frequency control signal, the greater the frequency generated by the oscillation in the voltage controlled oscillator VCO.

The level adjusting unit 334 outputs the microwave at the corresponding power by the power control signal from the control unit 310. [ The level adjuster 334 may include a voltage controlled attenuator (VCA). According to the voltage level of the power control signal, the voltage control attenuator VCA performs the correction operation so that the microwave is output at the corresponding power. For example, the greater the voltage level of the power control signal, the greater the power level of the signal output from the voltage control attenuator VCA.

The level adjuster 334 can constantly output the power level for each of the plurality of microwaves by receiving the same power control signal from the controller 310 for each microwave during the heating period.

The amplifying unit 336 performs an amplifying operation so as to output through the frequency oscillating unit 332 and the level adjusting unit 334 at the set frequency and power. As described above, the amplifying unit 336 may include a solid state power amplifier (SSPA) using semiconductor devices, and may include monolithic microwave integrated circuits (MMICs) using a single substrate . Thus, the amplification unit 336 can be easily controlled by the control unit 310, and its size can be reduced, so that the devices can be integrated.

The directional coupler (DC) 338 transfers the microwave amplified by the amplifying unit 336 to the microwave transmitting unit 112. The microwave outputted from the microwave transmitting unit 112 heats the object in the cavity 134. On the other hand, the microwave that is not absorbed by the object and is reflected may be input to the directional coupler 338 through the microwave transfer unit 112 again. The directional coupler 338 transmits the reflected microwave to the controller 310.

The microwave generating unit 110 may further include a DC converting unit (not shown) disposed between the directional coupler 338 and the control unit 310 for converting the reflected microwave into a control signal . Here, the DC conversion unit (not shown) can be implemented as a diode device.

The microwave generating unit 110 is disposed between the amplifying unit 336 and the directional coupler 338. When the microwave amplified by the amplifying unit 336 is transmitted to the cavity 134, (Not shown) for passing microwaves reflected by the cavity 134 and blocking the microwaves reflected from the cavity 134. Here, the isolation unit (not shown) may be implemented as an isolator.

The directional coupler 338 and the like including the frequency oscillator 332, the level controller 334 and the amplifier 336 in the microwave generator 110 may be implemented as a module . That is, they are all arranged on one substrate, and can be implemented as one module. With the integration of such elements, the microwave generator 110 can be easily controlled by the controller 310. [

The control unit 310 controls the overall operation of the cooking apparatus. When the operation signal of the cooking appliance is input through the operation unit 107, the control unit 310 controls the microwave generation unit 110 to output microwaves.

The control unit 310 calculates the heating efficiency for each of the plurality of microwaves based on the microwave reflected from the inside of the cavity among the microwaves output by the microwave generator 110.

In addition, the control unit 310 can variably control the heating time for each microwave or vary the power according to the calculated heating efficiency.

At this time, when the first microwave of the plurality of microwaves has a higher heating efficiency than the second microwave, the controller 310 sets the heating time of the first microwave to be shorter than the heating time of the second microwave.

Specifically, the control unit 310 outputs a frequency control signal and controls the frequency oscillation unit 332 to oscillate the corresponding frequency. That is, the control unit 310 outputs the center frequency (e.g., f10) control signal shown in Fig.

Meanwhile, the noise generating unit 410 outputs a random noise signal. At this time, the noise may be in the form of a white noise that can occur with the same probability within the coverage. Also, if the noise type is a Gaussian noise type that does not occur at the same probability in the coverage, a compensating process may be performed to generate noise with the same probability within the coverage.

The noise generator 410 may be a feedback shift register, and may output a pseudo noise (PN) sequence. This PN sequence is determined and cyclic, but appears to be random when viewed instantaneously over a random time interval because the period is long enough. In addition, it is possible to seed a true random value to the noise generating unit 410. Such a seed may be generated, for example, from random thermal noise. That is, the noise generating unit 410 may include an amplified thermal noise source, a noise oscillator, and the like. The thermal noise may be provided by a high-ohmic resistor or a reverse bias PN junction.

The adder 420 adds the center frequency control signal and the noise signal and outputs the sum. Meanwhile, the noise generator 410 and the adder 420 may be included in the controller 310.

Accordingly, the microwave generating unit 110 generates different frequencies f11, f12, f13, f14, f15, and f16 (see FIG. 5) in the f10 center frequency coverage 510 shown in FIG. 5, ) Can be generated and output.

At this time, the microwave generating unit 110 may generate a microwave based on the summed signals in the scan period during the cooking process using the microwave including the scan period and the heating period. Thereby, the frequency coverage can be increased during the scramble interval for a particular center frequency.

In addition, the microwave generating unit 110 can generate and output microwaves more densely than the frequency intervals of microwaves oscillating in the scan period, by frequency intervals of the microwaves oscillated in the heating period.

On the other hand, the control unit 310 can output frequency control signals of different voltage levels to output microwaves having a plurality of frequencies. Accordingly, the frequency oscillator 332 oscillates at a frequency corresponding to the voltage level of the input frequency control signal. The plurality of frequency control signals may be sequentially output from the control unit 310. [

The control unit 310 outputs a power control signal and controls the level adjusting unit 334 to output the corresponding power level.

At this time, the control unit 310 may output the same power control signal to each microwave during the heating period. Also, the level adjuster 334 can output a constant power level according to the input power control signal.

On the other hand, the control unit 310 can calculate the heating efficiency based on the microwave reflected into the cavity 134 without being absorbed by the object.

Here, Pt represents the power of the microwave emitted into the cavity 134, Pt represents the power of the microwave reflected by the cavity 134, and he represents the heating efficiency of the microwave. That is, the heating efficiency he becomes smaller as the reflected microwave power increases.

On the other hand, when a plurality of microwaves are emitted into the cavity 134, the controller 310 calculates the heating efficiency he for each frequency of a plurality of microwaves. It is preferable that the heating efficiency calculation is performed in the scan period during the entire cooking interval and during the heating interval.

Meanwhile, it is possible that the entire cooking interval is performed after the scan interval is performed, and the heating interval is performed while the scan interval is being performed. It is also possible to perform it repeatedly during the whole cooking section.

That is, the control unit 310 sequentially emits a plurality of microwaves to the heating object 140 in the cavity 134 during the cooking interval set by the user, and outputs the heating efficiency he Can be calculated.

Thereafter, the control unit 310 adjusts the emission time of the microwave for each frequency in the heating section, which is the actual cooking section, according to the calculated heating efficiency (he). That is, the higher the heating efficiency (he), the smaller the release time is. Thus, microwaves can be uniformly absorbed by the heating object 140 in the cavity 134 for each frequency, so that the heating object 140 can be uniformly heated.

On the other hand, the control unit 310 can control the microwave of the corresponding frequency to be emitted in the heating section only when the heating efficiency he calculated for each frequency is equal to or higher than the set value. That is, by excluding the microwave having a frequency with a significantly lower heating efficiency (he) from the actual heating section, the heating object 140 can be uniformly heated efficiently.

On the other hand, the above-described emission of the plurality of microwaves can be sequentially performed with time.

On the other hand, the control unit 310 can also control the display unit 105 to display the operation state of the cooking appliance. For example, if the current cooking interval is the current cooking interval, it can be displayed through the display unit 105, and if it is an actual heating interval, it can also be displayed. In addition, various display functions such as displaying the remaining time of the entire cooking section and the like can be performed.

The power supply unit 114 boosts the power supplied to the cooking apparatus 100 to a high pressure and outputs the power to the microwave generation unit 110. The power supply 114 may be implemented as a high-voltage transformer or an inverter. Meanwhile, the power supply unit 114 may generate and supply a predetermined control power for controlling the control unit (not shown).

Meanwhile, the control unit 310 and the microwave generating unit 110 may be implemented as a single module. That is, the control unit 310 and the microwave generating unit 110 may be integrated on a single substrate.

6 is a flowchart illustrating a method of controlling a cooking appliance using noise according to the present invention.

Referring to FIGS. 5 and 6, the control unit of the cooking appliance outputs a center frequency control signal for generating a center frequency such as f10, f20, and f30 shown in FIG. 5 (S602).

Further, the noise generating unit of the cooking appliance generates a random noise signal (S604), and the adding unit adds the noise signal to the center frequency (for example, f10) control signal (S606), and the microwave generating unit And generates and outputs a plurality of microwaves having different frequencies, such as f11, f12, f13, f14, f15, and f16 shown in FIG.

That is, the frequency oscillation unit of the microwave generation unit generates a plurality of microwaves having frequencies of f11, f12, f13, f10, f14, f15, and f16, respectively.

The level adjuster adjusts the level corresponding to the amplitude of the microwave generated by the frequency oscillator according to the power control signal provided from the power controller.

The amplifying unit amplifies the level-adjusted microwave, the isolation unit provides the amplified microwave to the directional coupler, the directional coupler provides the microwave provided by the isolation unit to the microwave transmission unit, and the microwave transmission unit supplies the directional coupler And transmits the microwave provided by the cavity to the cavity.

When a part of the microwave outputted by the cavity is reflected, the directional coupler provides the reflected microwave to the DC conversion unit, and the DC conversion unit converts the feedback signal obtained by converting a part of the microwave reflected from the cavity into DC to the control unit to provide.

The control unit calculates the heating efficiency for each of the plurality of microwaves based on the provided feedback signal (S610). At this time, the controller can determine that the heating efficiency is high when the feedback signal for each microwave is small.

In addition, the control unit may variably control the heating time for each microwave during the heating period according to the calculated heating efficiency (S612).

Accordingly, the microwave-assisted cooking apparatus according to the present invention generates microwaves more precisely than the frequency intervals of the microwaves oscillating in the scan period, thereby improving the scanning efficiency have.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention.

Figure 1 shows a general sweep frequency.

2 is a partial perspective view of a microwave oven according to an embodiment of the present invention.

3 is a cross-sectional view of the cooking appliance of Fig.

Fig. 4 is a block diagram schematically showing the inside of the cooking apparatus of Fig. 1; Fig.

5 is a diagram illustrating a frequency used in a scan period;

6 is a flowchart illustrating a method of controlling a cooking appliance using noise according to the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS Fig.

310: control unit 410: noise generating unit

420: adder 110: microwave generator

Claims (11)

A control unit for outputting a center frequency control signal; A noise generator for outputting a noise signal; An adder for summing the center frequency control signal and the noise signal; And And a microwave generation unit for generating and outputting a plurality of microwaves having different frequencies within the center frequency coverage based on the summed signals, The control unit calculates the heating efficiency for each microwave based on the reflected microwave for each of the plurality of microwaves output by the microwave generating unit, Wherein, And the heating time for each microwave is variably controlled during the heating period according to the heating efficiency. The method according to claim 1, Wherein the microwave- And a microwave is generated based on the summed signal in a scan period during a cooking process using a microwave including a scan period and a heating period. The method according to claim 1, Wherein the microwave- Wherein the frequency interval of the microwave oscillating in the heating section is generated more densely than the frequency interval of the microwave oscillating in the scan interval and outputted. delete delete The method according to claim 1, Wherein, And the power for each microwave is variably controlled during the heating period according to the heating efficiency. Outputting a center frequency control signal; Outputting a noise signal; Summing the center frequency control signal and the noise signal and outputting a summation signal; And Generating a plurality of microwaves having different frequencies within a center frequency coverage and outputting the microwaves as a cavity during a scan period based on the sum signal; Calculating heating efficiency for each microwave on the basis of the microwave reflected from the cavity for each of the plurality of output microwaves; And varying the heating time for each microwave during the heating period according to the heating efficiency. 8. The method of claim 7, The microwave outputting step includes: And generating and outputting a plurality of microwaves with a frequency interval that is denser than a frequency interval oscillated in the scan period during a heating period after the scan period. delete delete 8. The method of claim 7, After the heating efficiency calculating step, And controlling variable power of each microwave during a heating period according to the heating efficiency.

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