KR20110008928A - A cooking apparatus using microwave - Google Patents

Abstract

PURPOSE: A cooking apparatus using microwave is provided to enhance operating efficiency since a microwave generating unit for outputting a plurality of microwaves and a magnetron for outputting single microwave are used together. CONSTITUTION: A cooking apparatus using microwave comprises a first microwave generating unit(110) and a second microwave generating unit(115). The first microwave generating unit generates a plurality of microwaves to heat the target in a cavity. The second microwave generating unit generates a plurality of microwaves, which is different from the first microwave generating unit, to heat the target in the cavity.

Description

Cooking apparatus using microwaves {A cooking apparatus using microwave}

The present invention relates to a cooking appliance using a microwave, and more particularly to a cooking appliance using a microwave that can improve the operating efficiency.

In general, when a cooking apparatus using a microwave is sealed after storing food, when the operation button is pressed, a voltage is applied to the high pressure generator, and a commercial voltage applied to the high pressure generator is stepped up to generate a second microwave to generate microwaves. Power is applied to the unit, and the microwave generated by the second microwave generator is transmitted to the cavity through a wave guide or the like.

At this time, the cooking apparatus using the microwave is to heat the food by friction heat generated by irradiating the microwaves generated by the second microwave generating unit to the food to vibrate the molecules constituting the food 2.25 billion times per second .

Cooking apparatus using such a microwave is a situation that is widely spread in the general home due to various advantages such as easy temperature control, saving of cooking time, ease of operation.

However, when cooking food using microwaves, there is a problem that a temperature difference occurs partially in the food without being uniformly heated by the surface deviation of the food. In addition, there is a problem that the temperature deviation during cooking also varies depending on the type of food stored in the cooking apparatus.

An object of the present invention is to provide a cooking device using a microwave that can improve the operating efficiency.

The cooking apparatus using a microwave according to an embodiment of the present invention for solving the above problems, the first microwave generating unit for generating and outputting a plurality of microwaves to heat the object inside the cavity, the object inside the cavity And a second microwave generator configured to generate and output a plurality of microwaves different from the first microwave generator to heat the microwave.

According to an embodiment of the present invention, the first microwave generating unit for generating and outputting a plurality of microwaves to heat the object inside the cavity, and the planets for outputting a plurality of microwaves of different frequencies from the first microwaves By using the second microwave generation unit together, it is possible to improve the operation efficiency.

In particular, when driving by dividing into a scan section and a heating section for calculating the heating efficiency by using microwaves in the broadband frequency range, it is possible to divide the broadband frequency range by sections using a plurality of microwave generation units, The operation efficiency of the microwave generator is improved.

On the other hand, it is possible to calculate the heating efficiency based on the microwaves output from each of the first and second microwave generators and reflected, and to vary the output period of the microwave according to the calculated heating efficiency. Thereby, uniform heating is attained.

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

1 is a partial perspective view of a cooking appliance using a microwave according to an embodiment of the present invention, Figure 2 is a cross-sectional view of the cooking appliance of FIG.

Referring to the drawings, the cooking appliance 100 using the microwave according to an embodiment of the present invention, the door 106 is attached to the cooking window 104 in the front portion of the main body 102 is coupled to open and close. 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, and although not shown in the drawing, a filter part (not shown) for shielding the microwave may be provided inside the door 106.

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

The inside of the main body 102 is provided with a cavity 134 having an accommodation space of a predetermined size so that the heating target 140, for example, food is accommodated and cooked by a microwave.

In addition, a first microwave generator 110 for generating microwaves is installed on an outer surface of the cavity 134, and a first microwave generator 110 is provided on an output side of the first microwave generator 110. The first microwave transmitter 112 for guiding the microwaves generated at the inside of the cavity 134 is disposed.

The first microwave generator 110 may include a solid state power amplifier (SSPA) using a semiconductor. Solid-state power amplifiers (SSPAs) have the advantage of taking up less space than magnetrons.

On the other hand, the solid state power amplifier (SSPA), a hybrid high-frequency integrated circuit (HMIC), or a passive element (passive and passive elements (capacitors and inductors, etc.) and active elements (transistors, etc.) are separately provided for amplification; The active device may be implemented as a single high frequency integrated circuit (MMIC) implemented as a single substrate.

Meanwhile, according to the embodiment of the present invention, the first microwave generator 110 may generate and output a plurality of microwaves. The frequency range of such microwaves may be around 900 MHz to 2500 Hz.

In the embodiment of the present invention, it is assumed that the frequency range of the first microwave generator 110 and the frequency range of the second microwave generator 115 to be described later are distinguished. For example, the frequency range of the first microwave generator 110 may be approximately 900 MHz to 1600 Hz, and the frequency range of the second microwave generator 115 may be approximately 1600 MHz to 2500 Hz.

The first microwave transmitter 112 transmits the microwave generated and output by the first microwave generator 110 to the cavity 134. The first microwave transmitter 112 may include a waveguide or a coaxial cable. In order to send the generated microwaves to the first microwave transmitter 112, as shown in the figure, the feeder 142 may be connected.

Meanwhile, the first microwave transmitter 112 may be implemented in an open form with an opening 145 into the cavity 134 as shown in the drawing, but is not limited thereto, and an antenna is coupled to an end portion thereof. It is also possible. The opening 145 may be formed in various shapes such as a slot shape. Through the opening 145 or the antenna, the microwaves are emitted to the cavity 134.

Meanwhile, although one opening 145 is illustrated above the cavity 134 in the drawing, the opening 145 may be disposed below or on 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 the coupling is performed through the antenna instead of the opening 145.

The second microwave generator 115 generates and outputs a plurality of microwaves having a frequency range different from that of the first microwave generator 110 described above to heat the object inside the cavity.

The second microwave generator 115 may include a solid state power amplifier (SSPA) using a semiconductor. Solid-state power amplifiers (SSPAs) have the advantage of taking up less space than magnetrons.

The second microwave generator 115 has substantially the same operation as the above-described first microwave generator 110, except that the frequency range is divided.

The second microwave transmitter 113 transmits the microwaves generated and output by the second microwave generator 115 to the cavity 134. The second microwave transmitter 113 may include a waveguide or a coaxial cable. A feeder (not shown) may be connected to transmit the generated microwaves to the second microwave transmitter 113.

The second microwave transmitter 112 may be implemented in an open form, but is not limited thereto, and an antenna may be coupled to an end portion thereof.

Below the first microwave generator 110, a power supply 114 for supplying power to the first microwave generator 110 and the second microwave generator 115 is provided.

The power supply unit 114 includes a high-voltage transformer for supplying power to the first microwave generator 110 and the second microwave generator 115 by boosting the power input to the cooking apparatus 100 to a high pressure, or An inverter may be provided to supply the first microwave generator 110 and the second microwave generator 115 with a high output voltage of about 3500V or more generated by one or more switch elements by performing a switching operation.

Meanwhile, a cooling fan (not shown) for cooling the first microwave generator 110 and the second microwave generator 115 may be installed around the first microwave generator 110.

Although not shown in the drawings, a turntable (not shown) for rotating the heating object 140 may be installed in the cavity 134. Also, in the cavity 134, a microwave may be distributed to disperse the microwave. A stirrer fan (not shown) may be generated, and a cover (not shown) may be installed to prevent damage to the stirrer fan (not shown). Such a stirrer fan (not shown) may be regarded as a kind of antenna described above.

In the cooking apparatus 100 using the microwaves described above, the user opens the door 106, puts the heating object 140 into the cavity 134, and then closes the door 106, and then the operation panel 108. ), In particular, by pressing the cooking selection button (not shown) and the start button (not shown) by operating the operation unit 107, it is operated.

That is, the power supply unit 114 in the cooking apparatus 100 boosts the input AC power to a high-pressure DC power supply and supplies it to the first microwave generator 110 and the second microwave generator 115, and The first microwave generator 110 and the second microwave generator 115 generate and output corresponding microwaves, and the first microwave transmitter 112 and the second microwave transmitter 1130 are respectively The microwaves generated by the first microwave generator 110 and the second microwave generator 115 are transmitted to be emitted to the cavity 134. Accordingly, the object to be heated 140, for example, food, inside the cavity 134 is cooked.

On the other hand, in the drawing is shown as showing two microwave generating unit, but is not limited to this, in the embodiment of the present invention, it is sufficient to use a plurality of microwave generating unit to efficiently partition the wide frequency range. Thus, it is also possible to use three or more microwave generators.

3 is a block diagram schematically illustrating the inside of the cooking appliance of FIG. 1.

Referring to the drawings, the cooking apparatus 100 according to the embodiment of the present invention includes a first microwave generator 110, and a second microwave generator 115. In addition, the cooking apparatus 100 may further include a controller 310, a first microwave transmitter 112, and a second microwave transmitter 113.

The first microwave generator 110 includes a frequency oscillator 332, a level adjuster 334, and an amplifier 336. In addition, the first microwave generator 110 may further include a directional coupler 338.

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

The level adjusting unit 334 oscillates to output microwaves at a 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 attenuation unit VCA performs a correction operation so that microwaves are output at a 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 attenuation unit VCA.

The amplifier 336 performs an amplification operation to output the set frequency and power through the frequency oscillator 332 and the level adjuster 334. As described above, the amplifying unit 336 may include a solid state power amplifier (SSPA) using a semiconductor device, and in particular, may include a single high frequency integrated circuit (MMIC) using a single substrate. . As a result, the amplifier 336 can be easily controlled by the controller 310, and the size of the amplifier 336 can be easily reduced to achieve integration of the device.

The directional coupler (DC) 338 transmits the microwaves amplified by the amplifier 336 to the first microwave transmitter 112. The microwave output from the first microwave transmitter 112 heats the object in the cavity 134. Meanwhile, the microwaves, which are not absorbed by the object and reflected, may be input to the directional coupler 338 through the first microwave transmitter 112. The directional coupler 338 transmits the reflected microwaves to the controller 310.

Meanwhile, the first microwave generator 110 may be further disposed between the controller 310 in the directional coupler 338 and further include a DC converter (not shown) for converting the reflected microwave into a control signal. Can be. The DC converter (not shown) may be implemented as a diode device.

On the other hand, the first microwave generator 110 is disposed between the amplifier 336 and the directional coupling unit 338, in the case of delivering the microwave amplified by the amplifier 336 to the cavity 134 Passing the microwave, the microwave reflected from the cavity 134 may further include an isolation (not shown) for blocking. Here, the isolation unit (not shown) may be implemented as an isolator.

Meanwhile, the directional coupler 338, as well as the frequency oscillator 332, the level adjuster 334, and the amplifier 336 in the first microwave generator 110 described above, may be a single module. It is also possible to implement as. That is, it is possible to be all disposed on one substrate, to be implemented as one module. By the integration of the device, the first microwave generator 110 may be easily controlled by the controller 310.

On the other hand, although not shown in the drawing, the second microwave generator 115 is the same as the first microwave generator 110, a frequency oscillator (not shown), a level adjuster (not shown), and an amplifier ( Not shown). In addition, the second microwave generator 115 may further include a directional coupler (not shown).

Meanwhile, in the embodiment of the present invention, the first microwave generator 110 and the second microwave generator 115 for generating a plurality of microwaves are used together to partition the frequency range.

As described later, the first microwave generator 110 and the second microwave generator 115 that generate a plurality of microwaves calculate a heating efficiency, and vary the heating time according to the efficiency to target the target. Ensure uniform heating.

However, the first and second microwave generators 110 and 115 have a disadvantage in that the efficiency is lower as power consumption is used as the wide frequency range is used.

Accordingly, in the embodiment of the present invention, in consideration of power consumption, a plurality of microwave generation units and a plurality of microwave transmitters corresponding thereto are used. In the drawings, two microwave generators and two microwave transmitters corresponding thereto are illustrated. However, the present invention is not limited thereto, and various microwave generators and transmitters may be used.

The controller 310 controls the overall operation of the cooking appliance. When the operation signal of the cooking appliance is input through the operation unit 107, the control unit 310 controls the first microwave generation unit 110 and the second microwave generation unit 115 to control the microcomputer in the wideband frequency range. Output waves sequentially.

For example, as described below, the controller 310 controls the first microwave generator 110 to sequentially output microwaves of a lower frequency band, and the second microwave generator 115 It can be controlled to sequentially output microwaves of a higher frequency band.

Hereinafter, the control unit 310 will be described based on the contents of controlling the first microwave generator 110.

The controller 310 outputs a frequency control signal and controls the frequency oscillator 332 to oscillate a corresponding frequency.

The controller 310 may output frequency control signals having different voltage levels in order to output microwaves having a plurality of frequencies. Accordingly, the frequency oscillator 332 oscillates the corresponding frequency according to the voltage level of the input frequency control signal. Meanwhile, the plurality of frequency control signals may be sequentially output from the control unit 310.

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

The controller 310 may output power control signals having different voltage levels in order to output microwaves having a plurality of powers. Accordingly, the level adjusting unit 334 outputs a corresponding power level according to the voltage level of the input power control signal. Meanwhile, the plurality of power control signals may be sequentially output from the controller 310.

In addition, the controller 310 may compare the power of the output microwave with the reference power, and control the power of the output microwave to be constant based on the difference signal. For example, when the first microwave generator 110 generates and outputs a plurality of microwaves, the controller 310 compares the plurality of microwave powers and the reference power, respectively, based on the difference signal. The power of the plurality of microwaves outputted may be controlled to be constant. This operation will be described with reference to FIG. 4 described later.

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

Here, Pt represents the power of the microwave emitted into the cavity 134, Pt represents the power of the microwave reflected from the cavity 134, he represents the heating efficiency of the microwave.

According to Equation 1, the heating efficiency he becomes smaller as the power of the microwave to be reflected increases.

On the other hand, when a plurality of microwaves are emitted into the cavity 134, the efficiency calculator 305 calculates the heating efficiency he for each frequency of the plurality of microwaves. Such heating efficiency calculation can be performed during the entire cooking section.

In particular, according to an embodiment of the present invention, it is more effective to be performed in the thawing process of the entire cooking section.

In the embodiment of the present invention, the scan period for calculating only the heating efficiency (he) is not required separately, the heating efficiency (he) is calculated immediately while heating the object, and the output period of the microwave according to the heating efficiency (he) It is possible to vary in real time.

The controller 310 generates and outputs a frequency control signal to vary the output period of the microwave depending on the calculated heating efficiency. The frequency oscillator 332 oscillates a corresponding frequency according to the input frequency control signal.

The controller 310 generates a frequency control signal to shorten the output period of the microwave when the calculated heating efficiency he is high. That is, while sequentially sweeping a plurality of microwaves, the output period of each microwave can be varied according to the calculated heating efficiency. In other words, the higher the heating efficiency he, the smaller the corresponding output period. Accordingly, the microwaves can be uniformly absorbed by the heating target 140 in the cavity 134 for each frequency, and the heating target 140 can be uniformly heated. Detailed operations of the controller 310 will be described later with reference to FIG. 4.

On the other hand, the control unit 310, it is also possible to control to output the microwave of the corresponding frequency only when the heating efficiency (he) calculated for each frequency is more than the set value. That is, the microwave having a significantly lower heating efficiency (he) is excluded from the actual heating section, thereby efficiently heating the heating object 140 uniformly.

On the other hand, the above-described cooking device 100, because the output period of the microwave in real time according to the heating efficiency, so that no separate storage unit, etc., it is also possible to omit a separate microprocessor.

Meanwhile, the above-described efficiency calculator 305, the controller 310, the frequency oscillator 332, the amplifier 336, the directional coupler 338, and the like in the first microwave generator 110 may be one. It is also possible to implement it as a module. That is, it is possible to be all disposed on one substrate, to be implemented as one module.

The power supply unit 114 boosts the power input to the cooking apparatus 100 to a high pressure and outputs the power to the first microwave generator 110. The power supply unit 114 may be implemented as a high voltage transformer or an inverter.

4 is a diagram illustrating the inside of the controller of FIG. 3.

Referring to the drawings, the controller 310 includes a proportional integral controller (PI controller) 450 to control the power of the microwaves output from the first and second microwave generators 110 and 115 to be constant. .

Hereinafter, the first microwave generator 110 of the first and second microwave generators 110 and 115 will be described.

As described above, the first microwave generator 110 receives the frequency control signal Sf and the level control signal Sp from the controller 310, and the frequency oscillator 332 receives the frequency control signal Sf. In accordance with the oscillation of the corresponding frequency, and receives the level control signal Sp, and outputs the corresponding level from the level adjusting unit 334, the microwave of the frequency and the set power level oscillated by the amplifier 336 Will print

In general, since the power Pt of the microwave output is open loop control without feedback, the power Pt of the microwave is not output by the power set by the controller 310.

Accordingly, when microwaves exceeding the set power level are output to the cavity 134, the power of the reflected microwaves may exceed the permissible range, resulting in a circuit element such as a DC converter (diode element). Etc.) is likely to be damaged. In addition, the accuracy of the calculated heating efficiency is also lowered.

Accordingly, in the embodiment of the present invention, the power Pt of the microwave output is controlled to be uniform.

The controller 310 may also include a storage unit (not shown) that stores the reference power Pref.

Accordingly, the control unit 310 compares the power Pt of the microwave output with the reference power Pref, calculates the difference signal Sd, and proportionally integrates the calculated difference signal Sd. Perform control.

Herein, the proportional integration controller 450 controls the error of the difference signal Sd to be zero. The proportional integration control signal Sc having the proportional integration control performed thereon is output to the level controller 334.

The level adjusting unit 334 receives the proportional integration control signal Sc and the level control signal Sp, and outputs a signal of a predetermined level. As a result, the amplifier 336 outputs a microwave of a constant power.

As such, the first microwave generator 110 outputs microwaves of a constant power by performing close loop control to feed back the power Pt of the microwaves.

Such closed loop control may be applied to the case where the first microwave generator 110 outputs a plurality of microwaves having different frequencies. Accordingly, the first microwave generator 110 outputs a plurality of microwaves of different frequencies having the same power.

5 is a view illustrating a microwave output from the cooking apparatus of FIG. 3.

Referring to the drawings, the control unit 310 is a plurality of microwaves (corresponding frequencies f1, ... f8) of the lower band frequency (corresponding frequencies f1, ... f4) of the first The first microwave generator 110 may be controlled to be output, and the microwaves of the upper band frequency (the corresponding frequencies f5, ... f8) may be controlled to be output from the second microwave generator 115. As described above, the frequency range of the upper band may be approximately 900 MHz to 1600 Hz, and the frequency range of the lower band may be approximately 1600 MHz to 2500 Hz.

Meanwhile, as described above with reference to FIG. 4, the controller 310 may control the power Pa of the microwaves output from the first and second microwave generators 110 and 115 to be constant. Accordingly, uniform heating can be performed in the scan section or the cooking section during the cooking process.

6 is a diagram illustrating a scan section and a cooking section of the cooking appliance of FIG. 3.

Referring to the drawings, the cooking apparatus according to the embodiment of the present invention can output a plurality of microwaves of different frequencies from the first and second microwave generating unit (110, 115).

On the other hand, the cooking section according to the scan section (Ts) for calculating the heating efficiency for each microwave of different frequencies (f1, f2, f3, ... f8) and the heating efficiency calculated in the scan section (Ts) The heating object in the cavity may be divided into a heating section Tf for actually heating.

According to the calculated heating efficiency, during the heating period Th, the output period or output power of each microwave of different frequencies f1, f2, f3, ... f8 can be varied. In the figure, the output period is shown as a constant, which means that the output power is variable. Thereby, the object in a cavity can be heated uniformly.

While the above has been shown and described with respect to preferred embodiments of the present invention, the present invention is not limited to the specific embodiments described above, it is usually in the technical field to which the invention belongs without departing from the spirit of the invention claimed in the claims. Various modifications can be made by those skilled in the art, and these modifications should not be individually understood from the technical spirit or the prospect of the present invention.

1 is a partial perspective view of a cooking apparatus using a microwave according to an embodiment of the present invention.

2 is a cross-sectional view of the cooking appliance of FIG.

3 is a block diagram schematically illustrating the inside of the cooking appliance of FIG. 1.

4 is a diagram illustrating the inside of the controller of FIG. 3.

5 is a view illustrating a microwave output from the cooking apparatus of FIG. 3.

6 is a diagram illustrating a scan section and a cooking section of the cooking appliance of FIG. 3.

BRIEF DESCRIPTION OF THE DRAWINGS Fig.

110: first microwave generator 112: first microwave transmitter

113: second microwave transmission unit 114: power supply unit

115: second microwave generator 134: cavity

310: control unit 332: frequency oscillator

334: level control unit 336: amplification unit

Claims (7)

A first microwave generator configured to generate and output a plurality of microwaves to heat an object in the cavity; And And a second microwave generator for generating and outputting a plurality of microwaves different from the first microwave generator to heat the object inside the cavity. The method of claim 1, A first microwave transmitter for transmitting a plurality of microwaves from the first microwave generator into the cavity; And And a second microwave transmitter for transmitting a plurality of microwaves from the second microwave generator into the cavity. The method of claim 1, And a control unit for controlling the first microwave generator and the second microwave generator to output microwaves having different frequencies. The method of claim 1, Each of the first and second microwave generators, A frequency oscillator for oscillating a corresponding frequency according to an input frequency control signal; And And an amplifier for amplifying the oscillated frequency signal and outputting a microwave for heating an object in the cavity. The method of claim 4, wherein Each of the first and second microwave generators, And a directional coupler for transmitting the microwaves into the cavity and receiving the microwaves reflected from the inside of the cavity. The method of claim 2, The control unit, Micro from the first and second microwave generator based on the heating efficiency calculated by the microwave output from the first and second microwave generator into the cavity and the microwave reflected from the cavity And cooking the frequency control signal to vary the output period of the wave. The method of claim 7, The control unit, And generating the frequency control signal such that the output period of the microwave becomes shorter as the calculated heating efficiency is higher.

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