JPS6318316B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a microwave oven.

Recently, it has become possible to perform various cooking functions in a microwave oven by using digital technology for its control.

Typical of these cooking functions are timer operation, temperature operation, delay time operation, or various combinations of these operations.

Here, timer operation means operating the microwave oven for a desired cooking time, and temperature operation means operating the microwave oven until the food reaches the desired cooking temperature. These timer and temperature operations are accompanied by output control, such that during the timer and temperature operations, a cooking output is set that represents the desired microwave energy intensity.

Furthermore, delayed time operation means that a desired time is set as the end time and the operation of the microwave oven is automatically started in order to finish cooking at or near that time. Involves timer operation or temperature operation. In a combination of delayed time operation and timer operation, the timer operation is completed exactly at the set end time by setting the cooking start time to the time that is the timer time that is the timer operation condition from the set cooking end time. In the combination of delay time operation and temperature operation, the time required to complete the temperature operation is fixedly determined in advance as an average value for various types of cooking, and such fixed time is set from the set cooking end time. By setting the cooking start time to the time that has gone back in time, the actual temperature operation ends at a time that is almost close to the cooking end time.

By the way, if the cooking output, that is, the microwave energy intensity set for output control, is too low, the temperature of the food to be cooked may not reach the desired temperature unless the microwave oven is operated for an extremely long time. A situation has arisen that is not desirable.

In particular, very low microwave energy intensities
This is necessary when thawing frozen foods, but such thawing cannot be performed during delayed time operation. That is, as long as microwave thawing is used instead of natural thawing, frozen foods are not usually left in the microwave for several hours before starting microwave heating.

Therefore, during the delay time operation, a very low microwave energy intensity is not set as in the case of defrosting, and if it is set, it is due to an erroneous operation. In the case of delayed time operation based on such erroneous operation, an extremely long cooking time is required due to the low microwave energy intensity, resulting in a situation where almost no cooking is completed at the scheduled cooking end time. .

Therefore, the object of the present invention is to provide a case in which a delay time operation is involved, and a predetermined non-function where the cooking output, which is the microwave energy intensity set when the temperature operation is combined, is greater than the defrosting output. If the defrosting output is lower than the defrosting output, it is assumed that the set cooking output is a setting error, and the predetermined non-defrosting output is automatically set to end the operation at approximately the scheduled time. It is something to do.

The present invention will be explained in detail below with reference to Examples.

FIG. 1 shows an overview of a microwave oven 10 according to an embodiment of the present invention and a probe 11 used during temperature operation.

The microwave oven 10 has a cooking chamber 12 and a control panel 13 on the main body side, and is pivotally connected to the main body side.
A door 14 for opening and closing two openings is provided. The control panel 13 is provided with an operation section 16 for controlling the operation of the microwave oven, which will be described later. A door latch 17 and a door switch knob 18 are protruded from the inner side of the door 14, and when the door is closed, these enter into the main body to turn on the interlock switch and the door switch, respectively.

The probe 11 has a needle-like insertion tip 19 and a plug 2.
0, when the probe is used, the insertion tip 19 is inserted into the food to be cooked, and the plug 20 is inserted into the cooking chamber 12.
inserted into a jack provided on the inner wall of the The insertion tip 19 of the probe 11 has a built-in temperature detection section, ie, a thermistor 19a, for detecting the temperature of the food to be cooked and outputting an analog signal according to the temperature. They are connected by a line 21.

FIG. 2 shows details of the operation section 16. The operation unit 16 has 10 numeric keys from 0 to 9, TIMER,
CLOCK.POWER, DELAY START,
It has six function keys, START and TEMP, and each of these keys is a normal contact type push button switch. The operating procedures and functions of each number key and function key will be described later.

FIG. 3 shows an electrical circuit diagram of the microwave oven 10. A microwave generating section 22 serving as a microwave energy generating means is connected to 60 Hz commercial power supply terminals 26 and 27 via an interlock switch 23, a door switch 24, and a bidirectional thyristor 25. The microwave generator 22 is a magnetron 28,
It has a well-known configuration including a high voltage transformer 29, a diode 30, a capacitor 31, and the like. The interlock switch 23 and door switch 24 are the door latch 17 and door switch knob 18, respectively, described in FIG.
The bidirectional thyristor 25 is turned on when a drive signal, that is, a gate signal GS, is input to its gate 32. Therefore, when the gate signal GS is present at the gate 32 of the bidirectional thyristor 25 while the door 14 of the microwave oven is closed, the magnetron 28 generates microwaves, and the energy is supplied to the cooking chamber 12 of the microwave oven.

The gate signal GS as a drive signal applied to the bidirectional thyristor 25 is given from the control section 33, and the details of the control section are shown in FIG.

In FIG. 4, the control section 33 finally generates the gate signal GS from the output AND gate 34 as a drive signal output section based on the key signal input generated by the operation section 16, and thereby Controls the thyristor 25.

The signal processing section 35 processes key operation signal inputs generated by the operation section 16, and distributes data or control signals to each part of the control section 33, particularly in accordance with the order of key operations on the operation section 16.

The details of the control section 33 will be explained below along with the operations of the control section 33 in accordance with various key operation sequences.

[A] Setting the current time The control unit 33 includes a time function, and to set the time, use the operation unit 16.
CLOCK key is used. That is, if the time is now 2:00, the key operations are performed in the order of CLOCK□2□0□0CLOCK.

At this time, the signal processing unit 35
A key operation signal is detected and the numeric data input thereafter is set in a current time generating section 36, which is comprised of a counter that can be preset as the current time.

Next, the signal processing unit 35 performs the second CLOCK
When a key operation signal is detected, the current time generator 3
6. By this activation, the current time generating section 36 updates the set current time based on the time signal, that is, the second signal SEC, generated from the time signal oscillating section 38. Therefore, the second time above
If the CLOCK key is operated at the correct moment of 2:00, the current time generator 36 will thereafter generate the correct current time signal.

[B] Timer operation Output control is always performed during timer operation. For example, if the microwave energy intensity of the 90th stage, that is, the cooking output, is to be operated for 10 minutes and 30 seconds, the POWER□9 Key operations are performed in the order of □0TIMER□1□0□3□0START. In addition, the cooking output is 99
It can be set in stages, with the first stage corresponding to the lowest output and the 99th stage corresponding to the highest output.

The signal processing unit 35 detects the POWER key operation signal, and sets the input numerical data as the cooking output to the output setting unit 3 consisting of a register.
9, then detects the TIMER key operation signal, and sets the numerical data input thereafter as the cooking time in the timer time setting section 46 consisting of a down counter. The signal processing section 35 further detects the START key operation signal and generates a start signal START, and the signal START passes through an OR gate 40 and sets a first flip-flop 41 as a first predetermined signal output section.

The set output (first predetermined signal) of the first flip-flop 41 immediately activates the output counter 42 and opens the output AND gate 34 as a drive signal output section.

When the output counter 42 is activated, it counts down the time signal generated by the time signal oscillator 38, that is, the count signal SSEC with a period of 0.2 seconds, and when the count reaches 0, it repeats the count down again from 99, and repeats this operation for the first time. This process is repeated as long as there is a set output from the flip-flop 41. Fifth
FIG. 5A shows the count contents of the output counter 42, and FIG. 5B shows the set output state of the first flip-flop 41.

The output comparison section 43 compares the contents of the output setting section 39 and the output counter 42, and when they match, outputs an output coincidence signal for setting the second flip-flop 44 as a second predetermined signal output section.
Output PS. The flip-flop 44 is reset by a 0 signal when the content of the output counter 42 reaches a specific value, ie, 0. The set output (second predetermined signal) of the second flip-flop 44 passes through the output AND gate 34 together with the set output of the first flip-flop 41, and becomes a drive signal, that is, a gate signal GS. Therefore, as shown in FIG. 5C, the gate signal GS has a repeating period of T (approximately 20 seconds in this case) as long as the first flip-flop 41 is in the set state, and within each period t (approximately 20 seconds in this case).
As a result, the magnetron 28 operates at a duty of t/T, and the cooking output, which is the microwave energy intensity for the food to be cooked, corresponds to such duty.

On the other hand, the set output of the first flip-flop 41 opens the AND gate 47 and sends the seconds signal SEC generated by the time signal oscillator 38 to the timer time setting section 46, and the timer time setting section 46 uses the seconds signal SEC to set the second signal SEC. Setting details (currently 10 minutes
30 seconds) and perform a down count.

When the content of the timer time setting section 46 becomes 0, the time comparison section 48 detects this and resets the first flip-flop 41 via the OR gate 45. Therefore, the output AND gate 34 is closed and the gate signal GS disappears. Thus, the magnetron 28 will supply microwave energy at the set cooking output until the set timer period has elapsed.

[C] Temperature operation In this case as well, the output control as described above is always carried out.

For example, to operate at the microwave energy intensity of the 97th stage, that is, the cooking output, and terminate the operation when the temperature of the food to be cooked reaches 80°C, use the operation unit 16 to select POWER□9□7TEMP□8□0START. Key operations are performed in this order.

The signal processing section 35 sets the output data [97] in the output setting section 39 by operating the POWER□9□7 keys as described above, and then detects the TEMP key operation signal and sets the numeric data [80] to be input thereafter. ]
is set in the temperature setting section 49 as the cooking temperature.
The signal processing section 35 further detects the START key operation signal, generates a start signal START, and the first flip-flop 41 is set. Therefore, the output counter 42 is activated, the output AND gate 34 is opened, a gate signal GS is generated, and the magnetron 28 oscillates with a duty corresponding to the set output.

On the other hand, the thermistor 19a in the probe 11 detects the temperature of the food to be cooked, and the analog-to-digital converter 50 converts the detected temperature into a digital quantity and sets it in the measurement temperature setting part 51, and also outputs the set output (the second one) of the first flip-flop 41. 1 predetermined signal)
When the temperature comparison section 52 exists, the temperature comparison section 52 compares the settings of the temperature setting section 49 and the measurement temperature setting section 51, respectively.

When the content of the measured temperature setting part 51, that is, the temperature of the food to be cooked matches the content of the temperature setting part 49, the temperature comparison part 52 outputs a temperature coincidence signal TS, and this signal passes through the OR gate 45 and resets the first flip-flop 41. do. The operation ends when the temperature of the food reaches the desired value (80°C in this case).

[D] Combination operation of delayed time operation and timer operation For example, when cooking is finished at 6:00 a.m. later than the current time, the cooking operation at that time is performed at the microwave energy intensity of the 90th stage, that is, the cooking output. Ten
Assuming that the operation is to run for a minute, keys are operated on the operation unit 16 in the order of DELAY START□6□0□0POWER□9□0 TIMER□1□0□0□0START.

The signal processing unit 35 detects the DELAY START key operation signal and converts the input numerical data [600] into the calculation unit 5 in the cooking start time setting unit 53.
3a in the register 53 in the setting section 53.
b, then POWER□9□0TIMER
By operating the keys □1□0□0□0, the cooking output data [90] is set in the output setting section 39 and the cooking time data [1000] is set in the timer time setting section 46, as described above. When the signal processing unit 35 detects the START key operation signal, the signal processing unit 35 detects the DELAY
It is determined that the START key has been operated, and an instruction is given to the calculation unit 53a in the cooking start time setting unit 53 to subtract the contents of the timer time setting unit 46 from the contents of the register 53b in the cooking start time setting unit 53. That is, based on such an instruction, the calculation section 53a in the cooking start time setting section 53 changes the contents of the register 53b (in this case, the end time is 6:00).
The contents in the timer time setting section 46 (currently 10 minutes electronic time) are subtracted from this content, and this result (currently 5:50) is set in the register 53b as the cooking start time.

The time comparison section 54 compares the contents of the current time generation section 36 and the register 53b in the cooking start time setting section 53.
When the two match, a time coincidence signal TMS is generated, and this signal is sent to the first flip-flop 41 via an OR gate 40.
Set.

Therefore, when the current time reaches 5:50, an operation similar to the above-mentioned [B] timer operation is automatically started, and the operation ends as scheduled at 6:00 after the timer time has elapsed.

[E] Combination operation of delayed time operation and temperature operation For example, when cooking is finished around 6:00 a.m. after the current time, the cooking operation at that time is operated at the microwave energy intensity of the 90th stage, that is, the cooking output. However, in order to continue the operation until the temperature of the food reaches 80° C., keys are operated on the operation unit 16 in the order of DELAY START□6□0□0POWER□9□0 TEMP□8□0START.

As described above, the signal processing section 35 controls the cooking start time setting section 5 at the stage up to the operation of the START key.
The cooking end time data [600] is sent to the register 53b via the calculation unit 53a of No. 3, and the output setting unit 39
the cooking output data [90], and the temperature setting section 49.
Set the electronic temperature data [80] respectively, and then
When the START key operation signal is detected, the
It is determined that the DELAY START key has been operated, and in this case, a fixed time value is determined from the contents of the register 53b in the cooking start time setting section 53,
For example, in order to subtract 10 minutes, the cooking start time setting section 5
3 to the arithmetic unit 53a. That is, based on such an instruction, the arithmetic unit 53a reads the register 53b.
Read the contents (in this case, the end time is 6:00), subtract the fixed time value of 10 minutes from this content, and set this result (5:50 in this case) in the register 53b as the cooking start time. . Therefore, in the register 53b in the cooking start time setting section 53, 5:50 is set as the operation start time, assuming that it takes a uniform 10 minutes for the temperature of the food to reach the desired value. become.

On the other hand, the abnormal output comparison section 55 determines that data has been set in both the cooking start time setting section 53 and the temperature setting section 49, and reads the contents of the output setting section 39 via the signal line 39a. A comparison is made to see if it is less than a predetermined non-decompressing output that is greater than the decompressing output, for example [50], and if it is less than [50], an abnormal output signal ES is output. The output changing section 56 is driven based on this signal ES and immediately changes the output set in the output setting section 39 to the predetermined non-decompression output [50]. In this case,
Since the contents of the output setting section 39 were [90], no changes are made.

The time comparison section 54 compares the contents of the current time generation section 36 and the contents of the cooking start time setting section 53, and outputs a time coincidence signal when the two match.
TMS is generated and the signal sets the first flip-flop 41.

Therefore, when the current time reaches 5:50, an operation similar to the above-mentioned [C] temperature operation is automatically started, and when the temperature of the food reaches 80℃,
The operation will end at the scheduled time of approximately 6:00.

As mentioned above, since it is assumed that it uniformly takes 10 minutes for the temperature of the food to be cooked to reach the desired value, an error occurs between the actual operation end time and the scheduled end time. By selecting the required time to be the average required time for various types of cooking, the above-mentioned error usually does not pose a practical problem.

However, if the cooking output is set to a very low value when the key is pressed, for example below the 50th level in this case, it will take an extremely long time for the temperature of the food to reach the predetermined temperature, and the actual end time will be delayed. It is far behind the scheduled end time and is not practical.

As a feature of the present invention, in the case of such a low output setting, the abnormal output comparison section 55 detects this, drives the output change section 56, and automatically changes the output setting section 39 to a predetermined non-defrosting output [50]. It should be noted that the operation is performed after setting the . In other words, by correcting and setting the output, the above-mentioned damage caused by long-term operation can be eliminated.

As explained above, according to the present invention, when the delay time operation is combined with the temperature operation, if the microwave energy intensity, that is, the cooking output, is erroneously set to a very low value such as when defrosting, Since the cooking output is automatically corrected, you will never be told that there is almost no cooking done at the scheduled end time; in other words, the actual cooking end time will be significantly different from the scheduled end time. It never shifts. In this case, the automatically corrected cooking output may be different from the originally intended value, but since the end of cooking is determined by the temperature, it will not be a complete cooking failure and will be at the scheduled end time. It is possible to obtain a cooking state that is ready to eat at a time approximately close to .

[Brief explanation of the drawing]

Fig. 1 is an overview perspective view of the microwave oven and probe of the present invention, Fig. 2 is a detailed view of the operating section of the microwave oven, Fig. 3 is an electric circuit diagram of the microwave oven, and Fig. 4 is the electric circuit. FIG. 5 is a detailed block diagram of the main parts of the microwave oven, and FIG. 5 is a signal waveform diagram for explaining the operation of the microwave oven. 11...Probe, 16...Operation unit, 19a...
...Thermistor (temperature detection section), 22...Microwave generation section (microwave energy generation means), 28
... Magnetron, 33 ... Control section, 34 ... Output AND gate (drive signal output section), 35 ... Signal processing section, 36 ... Current time generation section, 38 ... Time signal oscillation section, 39 ... Output Setting section, 41...first flip-flop (first predetermined signal output section), 4
2... Output counter, 43... Output comparison section, 44
...Second flip-flop (second predetermined signal output section), 49...Temperature setting section, 50...Analog-to-digital conversion section, 51...Measurement temperature setting section, 52...
...Temperature comparison section, 53...Cooking start time setting section, 5
4... Time comparison section, 55... Abnormal output comparison section, 5
6...Output change section.

Claims (1)

[Claims] 1. A microwave energy generation means, an operation section,
a signal processing section that processes an operation signal from the operation section; an output setting section that sets a cooking output based on signal processing of the signal processing section; and a cooking temperature that is set based on the signal processing of the signal processing section. a cooking start time setting section for setting a cooking start time based on the signal processing of the signal processing section; a time signal oscillation section; and a cooking start time setting section for setting the cooking start time based on the signal processing of the signal processing section. a current time generation section that updates the current time based on the time signal from the time signal oscillation section; and a cooking start time set in the cooking start time setting section and the current time updated by the current time generation section. a time comparison unit that outputs a time matching signal when the two match; a first predetermined signal output unit that outputs a first predetermined signal based on the time matching signal; An output counter that repeatedly performs counting operations based on the time signal from the time signal oscillation section compares the output set in the output setting section with the count value counted by the output counter, and when the two match, the output matches. an output comparison section that outputs a signal; and a second predetermined signal output section that outputs a second predetermined signal based on the output coincidence signal and cancels output of the second predetermined signal when the output counter counts a specific value. a temperature detection section that detects the temperature of the food to be cooked and outputs an analog signal according to the temperature; a conversion section that converts the analog signal into a digital signal; and a measurement temperature setting section where the digital signal is set. When outputting the first predetermined signal, the cooking temperature set in the temperature setting section and the digital signal set in the measurement temperature setting section are compared, and when the two match, the first predetermined signal output section is outputted. a temperature comparison section that outputs a temperature coincidence signal for canceling the output of the first predetermined signal;
a drive signal output section that outputs a drive signal for driving the microwave energy generating means based on a predetermined signal; further, a cooking temperature is set in the temperature setting section and a cooking start time setting section is set in the cooking start time setting section When the start time is set, the output set in the output setting section is compared with a predetermined non-defrosting output that is greater than the defrosting output, and an abnormal output signal is generated when the former output is less than the latter predetermined non-defrosting output. A microwave oven comprising: an abnormal output comparing section that outputs an output; and an output changing section that changes the output set in the output setting section to the predetermined non-defrosting output based on the abnormal output signal.