JP3397197B2 - Cooking device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooking device such as a microwave oven, and more particularly to a control circuit for reducing power consumption during standby when not in use.

[0002]

2. Description of the Related Art Recently, it has been desired to develop equipment friendly to the global environment, and especially for household electric appliances used on a daily basis, legislation concerning power consumption is being promoted. Among them, the electric power during standby, which is the non-operating time, is said to be 10% to 20% of the total power consumption, and is particularly noted.

Considering the actual usage of the microwave oven, it is the actual situation that the non-operating time, that is, the waiting time is overwhelmingly longer than the actual cooking time using the high frequency heating, the heater and the like.

A conventional microwave oven of this type is disclosed in Japanese Patent Laid-Open No. 7-2.
Those described in Japanese Patent No. 17906 were common. As shown in FIG. 5, this microwave oven is provided with a door switch 8 which operates in conjunction with opening and closing of a door provided between a commercial power source 7 and a power supply circuit 4 of a control circuit 3, and a door switch 8 which is arranged in parallel with the door switch 8. The power switching means 5 is provided so as to be connected. The control circuit 3 is supplied with electric power through the door switch 8 when the door is opened, and turns on the electric power opening / closing means 5 based on a signal from the door switch circuit 10 that detects the opening of the door, and is self-held. Therefore, electric power is continuously supplied to the control circuit 3. Further, when the door is closed and there is no input from the door switch circuit 10 or the key input circuit 2 within a certain time, the power opening / closing means 5 is turned off.

In the above structure, if the door is not opened / closed or key input is made within a certain time while the door is closed, the power opening / closing means 5 is turned off to cut off the power supply to the control circuit 3 of the microwave oven. , The electric power was not supplied until the opening operation of the next door.

Further, there is a microwave oven in which a power switch is provided instead of the door switch 8 connected in parallel with the power switching means 5. In this case, the power switch serves as a trigger for supplying power to the power circuit, and the power switching means 5 is turned on.
By doing so, the power supply to the control circuit 3 is continued.

[0007]

However, the above-mentioned conventional microwave oven has the first problem that electric power is consumed for a certain period of time as usual regardless of cooking every time the door is opened and closed. That is, in actual use, when the food is taken out and the food is taken out, the door is always opened and closed, so that power is always consumed for a certain period of time each time the door is opened. In addition, many people put food in a microwave oven for temporary storage, and it is wasteful that a certain amount of electric power is consumed every time food is taken in and out of the oven.

Further, there is a second problem that the electric power is consumed as usual until the door is closed, and that the door must be closed in order to turn off the standby electric power. That is, since the inside of the microwave oven is extremely hot in the microwave oven after cooking, many people cool the door with the door open, and in some cases, the door is left open. In this case, there is no power saving at all.

Further, since the opening of the door or the power switch is used as a trigger for supplying electric power to the control circuit, in the actual cooking setting operation, the menu can be set only after opening the door or operating the power switch. It is supposed to be. In the actual cooking setting operation, it is a reality that many people set the menu before opening the door, which has a third problem that the operation procedure is limited.

[0010]

Most of the power consumption during standby is power consumption by a microcomputer (hereinafter referred to as a microcomputer) and its peripheral circuits, and how to eliminate this power consumption.

In order to solve the above problems, the present invention is connected to a heating means for heating food, a plurality of key input means for setting cooking, a control means for controlling a cooker, and a commercial power source.
A power supply circuit for converting the commercial power supply into a DC voltage to supply power to the control means, a power opening / closing means provided between the power supply circuit and the control means for opening / closing the power to the control means, and an ON / OFF of the power opening / closing means. Holding means for controlling the OFF operation,
When the power opening / closing means is off, the holding means turns on the power opening / closing means by a signal output from any one of the key input means by a key operation or a signal from the control means, and the operation transits after the power opening / closing means is turned on. If not, the power switching means is turned off by the signal from the control means.

According to the above invention, regardless of whether the door is opened or closed, the power opening / closing means is turned on only after the cooking setting operation is performed, and power is supplied to the control means such as the microcomputer and peripheral circuits. Regardless of whether the door is open or closed, the power supply to the control means can be reduced.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A microwave oven according to claim 1 of the present invention is connected to a commercial power source, a plurality of key input means for setting cooking, a control means for controlling a cooking device, and a commercial power source.
A power supply circuit for converting a power supply into a DC voltage to supply power to the control means, a power opening / closing means provided between the power supply circuit and the control means for opening / closing power to the control means, and an ON / OFF of the power opening / closing means.
Holding means for controlling the OFF operation, and the holding means,
When the power opening / closing means is OFF, the power opening / closing means is turned ON by the signal output from any one of the key input means by the key operation or the signal of the control means, and the power opening / closing means is turned ON.
If the operation does not change after the above, the power opening / closing means is turned off by the signal from the control means, so that the power consumption in the control means can be reduced regardless of whether the door is opened or closed.

A microwave oven according to claim 3 of the present invention is
When no key is input for a predetermined time after being input from the key input means, it is determined that cooking is not performed and a signal for turning off the power opening / closing means is output to the holding means.
Therefore, it is possible to quickly eliminate unnecessary power consumption.

A microwave oven according to claim 4 of the present invention is
When the control means starts a program set by key input, if the key input is not made within a predetermined time after the program is completed or canceled.
A signal for turning off the power switching means is output to the holding means. Therefore, even if the door is opened / closed for taking out food after a while after the completion of cooking, the power supply to the control means is not restarted, and unnecessary power consumption can be eliminated.

A microwave oven according to claim 5 of the present invention is
When the control of the heating means is disabled by the control means, a signal for turning off the power switching means is output to the holding means. Therefore, since all the power supply to the control means is cut off, the operation of the heating means can be surely stopped irrespective of the control from the control means, so that a safer microwave oven can be obtained.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

(Embodiment 1) FIG. 1 is a block diagram of a control circuit for a microwave oven according to the present invention, and FIG. 2 is a diagram showing a control circuit for a microwave oven according to Embodiment 1 of the present invention. The same components as those in the conventional example are designated by the same reference numerals.

In FIG. 2, 7 is a commercial power source, 11-13.
Is a heater and high-frequency generator that are heating means 1 for heating food, 2 is a key input means for inputting cooking settings, and a plurality of switches are arranged in a matrix. Reference numeral 3 is a control means for controlling the heaters 11 to 12 which are the heating means 1 and the high frequency source 13 in order to execute the cooking setting inputted by the key operation, 4 is a power supply circuit of the control means 3, and 5 is a control means. Electric power opening / closing means for opening / closing the power supply, 6 holding means for controlling ON / OFF operation of the electric power opening / closing means 5, 9 a door switch for turning OFF / ON in association with opening / closing of the door, and 14-16 heaters 11 ~ 12 and relay contacts for turning on / off the high-frequency generation source 13, 17 is a relay contact for turning the heating means 1 on and off in a standby state other than a cooking operation and a standby state for cooking setting, 18 is a relay contact 14-17 Is a relay drive circuit for turning ON / OFF, and 19 is a relay contact detection circuit for detecting ON / OFF of the contacts 14 to 17 of the relay. The or welding of the relay contacts such as a circuit for detecting by monitoring the contact state of the relay. Reference numeral 20 denotes a microcomputer, which determines cooking conditions based on an input signal from the key input means 2 based on a preset program, and gives a signal to the relay drive circuit 18 so that the heaters 11 to 12 as the heating means 1 and high frequency generation. Controlling the source 13.

Next, the operation and action will be described. In the standby state where food is not cooked, the power opening / closing means 5 is in the open state and the power supply to the control means 3 is cut off. Further, the transistors Q1 to Q3 have a function of preventing a current from flowing into the control means 3 in the standby state. Similarly, the diodes D1 to D3 have a function of preventing a current from flowing into the control means 3 by a key operation.

Next, a plurality of keys S which are the key input means 2
When any one of W1 to SW9 is operated, the resistance R
A signal for turning on the power opening / closing means 5 is input to the holding means 6 via each resistance connected to the switch among the resistors 4 to R6 and the resistances R7 to R9. When the power switching means 5 is turned on, power supply to the control means 3 is started, and the resistors R1 to R3 and the diodes D1 to D3 and R7 are supplied.
A signal is input to the holding means 6 through R9, the power opening / closing means 5 continues to be turned on, and the power supply to the control means 3 is continued. After the supply of power to the control means 3 is started, the microcomputer 20 is activated to enter a cooking setting standby state. Regarding detection of key operation, the microcomputer 20
After activating, the scan signals are output in time series from the output ports P4 to P6 of the microcomputer 20. P1 to P3 are input / output ports, which are set as input ports in the cooking setting standby state and the cooking state. When the key is not operated, a Hi level signal is input to P1 to P3. When the key is operated, the operated key is determined by the timing of the scan signal and which of the P1 to P3 the Lo level signal is input.

Further, the microcomputer 20 starts subtraction of a preset timer time after starting, and if there is no input from the key input means 2 during that time, the power switching means 5 is turned on when the remaining time becomes zero. Turn off signal P1
By switching P3 to the output port and performing Lo level output, a signal for turning off the power switching means 5 is output to the holding means 6.

If a key input signal is input from the key input means 2 to the microcomputer 20 before the remaining time of the timer reaches zero, the timer time is reset and the subtraction of the timer time is started again, and the remaining time is reset. A signal for turning off the electric power switching means 5 is output to the holding means 6 when the value becomes zero.

When the cook starts cooking,
The microcomputer 20 changes from the cooking setting standby state to the cooking state. Then, the microcomputer 20 resets the timer time after the cooking program is completed or canceled, and the subtraction of the timer time is started again, and when there is no input from the key input means 2 during that time, the remaining time becomes zero. At this time, a signal for turning off the power switching means 5 is output to the holding means 6.

Further, when it is not necessary to subtract the timer time of a certain time for the purpose of cooling the microwave oven or displaying the status after the cooking is finished or when the cooking is canceled during the cooking, the power opening / closing means 5 is immediately started. Needless to say, can be turned off. Further, it goes without saying that these timer times can be set to different minimum necessary times depending on the cooking program to be executed and the state of the microwave oven.

Then, when a key operation is performed after the power opening / closing means 5 is turned off, power is supplied to the control means 3 again.

Further, when the microcomputer 20 is started by a key operation from the standby state of the power switching means 5 being opened, the microcomputer 20 detects the state of the contacts of the relays 14 to 17 by the signal from the relay contact detection circuit 19, and the relay 14 If the contacts 17 to 17 are turned on when they should not be turned on, the power switching means 5 is turned off. Further, when the contacts of the relays 14 to 17 are turned on during the cooking operation, if they are turned on, the power opening / closing means 5 is turned off. Further, when the contacts of the relays 14 to 17 are turned on after the cooking operation is completed or canceled, the power opening / closing means 5 is turned off.

Further, even if the heating means 1 cannot be turned off due to a failure of the relay drive circuit 18, the microwave oven can be safely stopped by turning off the power opening / closing means 5. Further, even if any of the contacts of the relays 14 to 17 is welded, if the heating means 1 is cut into two by the relay contact 17 as in the present invention, the electric power opening / closing means 5 is turned off to safely operate the microwave oven. Can be stopped.

Second Embodiment FIG. 3 is a diagram showing a control circuit of a microwave oven according to a second embodiment of the present invention. The second embodiment differs from the first embodiment in that the input signal from the key input means 2 composed of switches arranged in a matrix to the microcomputer 20 is input as analog data. Two
The point is that the port P8 for detecting a key input of 0 is used as an AD input port and the number of ports for detecting a key input of the microcomputer 20 is reduced. The same reference numerals as those in the first embodiment have the same structure, and the description thereof will be omitted.

Next, the operation and action will be described. In the standby state in which the food is not cooked, the power opening / closing means 5 is in the open state and the power supply to the control means 3 is cut off. Next, a plurality of keys SW1 to S which are the key input means 2
When any key of W9 is operated, the resistances R13 to R
A signal for turning on the power opening / closing means 5 is input to the holding means 6 via each of the resistors connected to the switch among the resistor 15 and the resistors R10 to R12. When the power switching means 5 is turned on, power supply to the control means 3 is started, and the power switching means is turned on to the holding means 6 via the resistor R16.
A signal for turning off the power is input, the power switching means 5 continues to be turned on, and the power supply to the control means 3 is continued. After the power supply to the control means 3 is started, the microcomputer 20
Will start. Detection of key operation in the microcomputer 20
The operated key is determined based on the analog data input to P8 and the timing of the scan signals output in time series from P4 to P6. The analog data input to P8 is Q1 to Q connected to the operated switch.
3 collector-emitter voltage Vce and resistor R1
1 to R12 and the forward voltage Vf and R1 of D1. Input voltage Vin when SW1 to SW3 are pressed
Is Vin = Vcc (power supply voltage of microcomputer) −R1 ×
((Vcc-Vf-Vce) / R1) = Vf + Vce, and when SW4 to SW6 are operated, Vin = V
cc (power supply voltage of microcomputer) -R1 x ((Vcc-Vf
−Vce) / (R1 + R12)), and SW7 to SW
When 9 is operated, Vin = Vcc (power supply voltage of microcomputer) -R1 * ((Vcc-Vf-Vce) / (R1
+ R11 + R12)). And the microcomputer 20
Starts a subtraction of a preset timer time after starting, and if there is no input from the key input means 2 during that time, when the remaining time becomes zero, Q4 is turned off from P7.
The power switching means 5 is turned off by outputting a signal for N
The holding signal is input to the holding means 6. Then, the microwave oven was put into the standby state again.

(Third Embodiment) FIG. 4 is a diagram showing a control circuit of a microwave oven according to a third embodiment of the present invention. A rotary encoder is often used as the key input means 2 of the microwave oven, and as a method of using the rotary encoder, there are those having many input functions such as temperature setting, time setting, and cooking menu selection. Example 3
The difference from the first embodiment is that the key input means 2 is used. The same reference numerals as those in the first embodiment have the same structure, and the description thereof will be omitted.

Next, the operation and action will be described. SW10
Is a rotary encoder, and when it is rotated, the internal switch operates in the order of OFF → ON → OFF. Further, the rotary encoder SW10 changes which one of the two internal switches is turned on first, depending on the rotation direction thereof. And the microcomputer 2
0 detects whether the switch connected to the contact a or b of the rotary encoder SW10 at the input port P1 or P2 of the microcomputer 20 is first turned on,
The rotation direction and the number of times of ON are determined.

In the standby state where the food is not cooked, the power opening / closing means 5 is in the open state and the power supply to the control means 3 is cut off. Further, the diodes D1 to D3 and the transistor Q4 have a function of preventing a current from flowing into the control means 3 in the standby state. Next, the rotary encoder SW10 which is the key input means 2
Alternatively, when one of the keys SW1 is operated, a signal for turning on the power opening / closing means 5 is input to the holding means 6 via the operated rotary encoder SW10 or the diodes D4 to D6 to which the key SW1 is connected. When the power switching means 5 is turned on, power supply to the control means 3 is started. When the supply of power to the control means 3 is started, the microcomputer 20 is activated and the transistor Q4 is started from P7.
By outputting a signal to turn on the power switch
A signal for continuing N is input to the holding means 6. Then, the closing of the power switching means 5 is maintained, and the power supply to the control means 3 is continued.

In D4 to D6, the input signal input to the microcomputer 20 by the key operation is spilled to an input port different from the input port to which the operated key is connected, and the key operated by the microcomputer 20 can be determined. It works to prevent disappearance. Further, the microcomputer 20 starts subtraction of a preset timer time after starting, and when there is no input from the key input means 2 during that time, when the remaining time becomes zero, Q4 is turned off from P7. A signal for turning off the power switching means 5 by outputting the signal is input to the holding means 6. Then, the microwave oven was put into the standby state again.

An example of comparison of standby electric energy between the microwave oven of this embodiment and the conventional microwave oven will be described below.

In recent years, power supply circuits using switching elements are increasingly provided with a function of changing the switching condition and suppressing the power consumption in a standby state where the load of the power source is small in order to suppress the power consumption during the standby. As in the present embodiment, the control means that becomes the load of the power supply circuit is disconnected and the load is set to 0
In that case, there are many power supplies whose power consumption at that time is 50 mW or less. The standby power of the microwave oven of this embodiment using such a power supply circuit is 50 m per day.
W × 24 hours = 1.2 Wh. In the case of the conventional microwave oven, since the user determines the action of cooking by opening and closing the door, turn on the power opening / closing means for the time required for setting and preparing the cooking after opening / closing the door. I need to put it. Generally, most of the time is 10 minutes. The power consumed in such a case is consumed by the relay used for the power switching means, the microcomputer, the display circuit and their peripheral circuits, and is at least about 3 W. In the case of households that use the microwave oven six times a day, the power consumed per day after opening and closing the door to take out food is 3W x 10 minutes / 60 minutes x 6
The number of times is 3.0 Wh.

Further, the more the household uses the microwave oven, the more this wasted power is consumed. Furthermore, when the microwave oven is used for temporary storage of food, storage and removal of food and consumption of unnecessary electric power (3 W x 10 minutes / 60 minutes x 2 times = 1.0 Wh) are performed each time. . Furthermore, if the door is left open, the standby power will be 0.
Will not be. Considering these actual use states, the microwave oven of the present embodiment based on the present invention has an effect of suppressing standby power to be smaller than that of the conventional microwave oven.

Although a microwave oven having a heater and a high frequency source has been described as the heating means in this embodiment, the heating means is not limited to this, and the heating means may have only the high frequency source. Good. Further, it goes without saying that the cooking device may use only a heater as the heating means.

[0039]

As described above, in the microwave oven according to the first to fourth aspects of the present invention, the action of the user trying to cook is detected by the key operation which is the setting operation of the cooking condition, and the control means is used. When the power is supplied to a certain microcomputer and its peripheral circuits and cooking is not performed, the power supply is turned off.
Therefore, even if the door is opened / closed regardless of cooking, a certain amount of power is not consumed each time the door is opened / closed as in the conventional case, so that unnecessary power consumption is reduced. There is an effect that can be.

Further, since the opening of the door is not used as a trigger for supplying electric power to the control circuit, there is an effect that it is not necessary to open and close the door each time cooking is performed.

Further, since there is no need to operate the power switch, there is an effect that the operation procedure is not limited.

Further, in the microwave oven according to the fifth aspect, when the control of the heating means by the control means becomes impossible, the operation of the microwave oven is stopped by turning off the power opening / closing means. The effect is that it can be a safe microwave oven.

[Brief description of drawings]

FIG. 1 is a block diagram of a control circuit of a microwave oven according to a first embodiment of the present invention.

FIG. 2 is a control circuit diagram of the microwave oven according to the first embodiment of the present invention.

FIG. 3 is a control circuit diagram of a microwave oven according to a second embodiment of the present invention.

FIG. 4 is a control circuit diagram of a microwave oven according to a third embodiment of the present invention.

FIG. 5 is a control circuit diagram of a conventional microwave oven.

[Explanation of symbols]

1 heating means 2 key input means 3 control means 4 power supply circuit 5 Power switching means 6 holding means

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-7-217906 (JP, A) JP-A-4-174219 (JP, A) JP-A 61-66022 (JP, A) JP-A 56- 19894 (JP, A) (58) Fields surveyed (Int.Cl. ⁷ , DB name) A47J 27/00 109 F24C 7/02 340 F24C 7/04 301 H05B 3/00 330 H05B 6/68 310

Claims (5)

(57) [Claims] 1. A heating means for heating food, a plurality of key input means for setting cooking, a control means for controlling a cooking device, and a commercial power source connected to the commercial power source to convert the commercial power source into a DC voltage.
And conversion to a power supply circuit for supplying power to said control means, and a power switching means for opening and closing the electric power to said control means is provided between said power supply circuit and said control means, ON said power switching means
Holding means for controlling ON / OFF operation, the holding means, when the power opening / closing means is 0FF, the holding means uses the signal output from any one of the key input means by a key operation or the signal of the control means. ON / OFF means
A cooker characterized in that when the operation does not transition after the power switching means is turned on, the power switching means is turned off by a signal from the control means. 2. The cooker according to claim 1, wherein the plurality of key input means are arranged in a matrix. 3. The control means outputs a signal for turning off the power opening / closing means to the holding means when no key input is made for a predetermined time after the key input means is operated by key operation. Or the cooking device described in 2. 4. The electric power switching means when the program set by key input is started, or when the key input is not made within a predetermined time after the program is completed or canceled when the program set by key input is started. The cooking device according to claim 1 or 2, wherein a signal for turning off is output to the holding means. 5. The control means outputs a signal for turning off the power switching means to the holding means when the control of the heating means is disabled.
The cooker according to any one of items 1 to 4.