JPH0222519B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electronically controlled cooking device, and more particularly to an electronically controlled cooking device that measures the temperature of food to be cooked and controls cooking operation based on the measurement results.

Conventionally, as this type of cooking appliance, one using a temperature probe as a temperature measuring means has been put into practical use.

In other words, with this type of cooker, a temperature probe with a built-in thermistor or the like is inserted into the food.
In this state, the food to be cooked is irradiated with heating energy, and the heating energy irradiation is controlled based on temperature information measured through the temperature probe.

However, the drawbacks of such cookers are that the outer shape of the food is undesirably disrupted by inserting the temperature probe into the food, and the temperature probe must be cleaned before use. Even more fatally, the temperature cooking operation cannot be performed on foods such as frozen foods for which it is impossible to insert a temperature probe.

On the other hand, it has been proposed to use an infrared detection element as a temperature measurement means instead of using a temperature probe. That is, temperature information is obtained by detecting infrared rays emitted from the food by an infrared detection element, and heating energy irradiation is controlled based on this information. In such a case, the temperature of the food is measured in a non-contact manner. Because of this, unlike when using a temperature probe, the outer shape of the food will not be distorted, and it is clean, and furthermore, it is possible to perform temperature cooking operations on solid food such as frozen foods.

However, it has been difficult to put a cooking appliance using an infrared detection element into practical use because its control system is complicated, and in fact, no such cooking appliance exists today. Therefore, an object of the present invention is to put into practical use a cooking appliance that uses an infrared detection element as a temperature measuring means and controls heating energy irradiation based on the output of the element.

The configuration of the present invention includes a heating energy generating means for supplying heating energy to an object to be heated, inputting infrared rays emitted from the object to be heated, and generating a measurement voltage corresponding to the temperature of the object to be heated; a first voltage generating means having an input/output characteristic in which the relationship between the voltage measured by the temperature body of the heated object is non-linear; a second voltage generating means generating a temperature corresponding voltage for comparison according to the input/output characteristic; The heating energy generation means is further provided with a control means for controlling the heating energy generation means based on a comparison result between the measured voltage and the comparison temperature voltage.

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

Although the embodiments of the present invention are directed to microwave ovens, the present invention can also be effectively applied to other electric cooking appliances.

FIG. 1 shows an overview of a microwave oven 10 according to an embodiment of the present invention.

The microwave oven 10 includes a cooking chamber 12 and a control panel 13 on the main body side, and a door 14 that is pivotally attached to the main body side and opens and closes the opening of the cooking chamber 12. The control panel 13 includes a display section 15 that displays information such as time.
and an operation unit 16 for operating the operation of the microwave oven.
are arranged, and these will be described later. door 1
A door latch 17 and a door switch knob 18 are protruded from the inner side of the door 4, and when the door is closed, these enter into the main body to turn on the interlock switch and the door switch, respectively.

FIG. 2 shows details of the display format on the display section 15. The display 15 includes a fluorescent numeric display tube, which is known per se, and is capable of displaying a four-digit number and a colon. FIG. 2A shows the display form of the current time, in which case 3:05 is displayed including the central colon. FIG. 2B shows the display format during timer operation, and in this case, 10 minutes and 30 seconds is displayed without the colon being lit. Figure 2 C and D show the display format during temperature operation, 80℃ and -15℃ respectively.
℃ is displayed. FIG. 2e displays the letter F as a decompression instruction. The display section 15 displays other input information from the operation section 16 as appropriate.

FIG. 3 shows details of the operation section 16. The operation unit 16 has 10 numeric keys from 0 to 9, TIMER,
POWER, CLOCK, CLEAR, TEMP,
It has eight function keys: START, STOP, and DERFOST, 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. 4 shows the arrangement of components for infrared detection arranged between the upper wall 19 of the cooking chamber 12 and the exterior cabinet of the microwave oven. The infrared rays 20 emitted from the food placed in the cooking chamber 12 are
The concave mirror 23 reaches outside the cooking chamber through the opening 21 in the center of the upper wall 19 and is chopped by the chopper 22.
The light is focused by the infrared rays and reaches the infrared detection element 24.

A metal cylinder 25 is fitted into the opening 21 in the upper wall of the cooking chamber, and the opening at the tip of the cylinder is covered with an infrared transmitting cover 26 made of polyethylene or the like. The metal cylinder 25 has an inner diameter of 20 mm and a length of 12 mm, and the microwaves supplied to the cooking chamber cannot pass through the cylinder.

The chopper 22 is composed of a perforated disc that is rotationally driven by a synchronous motor 27, and converts the incident infrared rays 20 into 20
The photointerrupter 30 consists of a light emitting element 28 and a light receiving element 29 facing each other with the chopper 22 in between.

The infrared detection element 24 is made of lithium tantalate (LiTaO ₃ ) crystal, and this element itself is well known as a pyroelectric infrared detection element. That is, now,
Set the temperature of the food to be cooked, and the temperature of the Chiyotupa 22 itself.
When Tc, infrared rays corresponding to the temperature To and infrared rays corresponding to the temperature Tc are alternately incident on the element 24 at a cycle of 20 Hz, and the element 24 generates a voltage corresponding to the difference between the two temperatures To and Tc. The temperature of the food detected by the element 24 differs by the temperature of the chopper 22 in this way, so in order to compensate for this, a semiconductor diode 31 is arranged near the chopper, and the temperature characteristics of the diode are used to adjust the temperature of the chopper 22 itself. Approximate temperature is being detected. Such compensation processing will be described later.

FIG. 5 shows an electric circuit diagram of the microwave oven 10, in which FIG. 5A shows a microwave generator and a power supply section, and FIG. 5B shows a control section for controlling the microwave generator. This is shown below.

In FIG. 5A, the microwave generator 40 is connected to 60 Hz commercial power supply terminals 43 and 44 via an interlock switch 41 and a bidirectional thyristor 42.

The microwave generator 40 includes a magnetron 45, a high voltage transformer 46, a diode 47, and a capacitor 4.
This is a well-known configuration including 8 etc. The interlock switch 41 is turned on by the door latch 17 described in FIG. 1, and the bidirectional thyristor 42 is turned on when a gate signal is applied to its gate 49.
Therefore, when the door 14 of the microwave oven is closed and a gate signal is present at the gate 49 of the bidirectional thyristor 42, the magnetron 45 generates microwaves.
The energy is supplied to the cooking chamber 12 of the microwave oven. A blower motor 50 is connected in parallel with the microwave generator 40, and a fan driven by the blower motor 50 cools the magnetron 45 while the magnetron 45 is oscillating.

The power terminals 43 and 44 are connected to the other power transformer 51, and the AC voltage stepped down by the power transformer 51 is transferred to the capacitor 52 and the diode 53.
The voltage is converted into a DC voltage by a rectifying and smoothing circuit consisting of the following, and is applied to the gate 49 of the bidirectional thyristor 42 via the gate switch circuit 54. The gate switch circuit 54 is connected to the light receiving transistor 5 of the photocoupler 55.
6, the light emitting diode 5 of the photocoupler 55
7 emits light in response to the signal PO from the control section in FIG. 5B. Bidirectional thyristor 49 is therefore supplied with a gate signal during the presence of signal PO.

The aforementioned synchronous motor 31 is further connected to the power supply terminals 43 and 44 via a relay contact 59.

The DC power supply unit 58 converts the AC voltage supplied from the power transformer 51 into various DC voltages and distributes them to each part of the circuit shown in FIG. 5B.

In FIG. 5B, the control section is composed of a microprocessor 60 made of a semiconductor large-scale integrated circuit, and in this embodiment, a microprocessor μPD553 manufactured by NEC Corporation is used.

The microprocessor 60 has many input/output terminals as shown in the figure, and each input/output terminal will be explained below. The CLo and CL1 terminals are circuit constant connection terminals for the basic clock signal oscillator in the microprocessor 60, and in this embodiment, by connecting a coil and a capacitor to these terminals, the oscillation frequency of the oscillator is set to 400 KHz. It has established. Ao〜
The A2 terminal is a data input terminal, and the terminal receives input data signals SAo, SA1, SA2 from the operation input section 61.
is entered in binary code form. Co to C2 and Do to D3
The terminals are display data output terminals, from which display data signals SD1 to SD7 are transmitted to the display section 15 in the form of binary codes. Eo to E3 and Io terminals are control signal output terminals, and control signals are output from these terminals respectively.
SEo, SE1, SE2, SE3, and SIo are transmitted to the display section 15 or the operation input section 61. RESET is an initial state setting signal input terminal, and the initial state setting signal IR is sent to this terminal from the initial state setting signal generation circuit 62. enter.

The terminal is a terminal for inputting a time reference signal for timing operation within the microprocessor 61.
A 60 Hz sine wave signal AC generated from the power transformer 51 in FIG.
B1 terminal is door signal DOR from door switch 64
This is the input terminal. The door switch 64 is the first
It is turned on by the doorknob 18 mentioned in the figure, and when it is turned on, that is, when the door is closed, a signal DOR is generated. The F3 terminal is a terminal that outputs a buzzer signal BZ, and when the signal BZ is present, a well-known buzzer circuit 65 operates to generate a buzzer sound. The F1 terminal is a heating instruction output terminal, from which the previously described signal PO is transmitted to the light emitting diode 57 of the photocoupler 55.
The Fo terminal is a terminal that generates the signal TE during temperature operation. Signal TE turns on transistor 66,
The signal INH is generated and the relay coil 6
7 is energized. By energizing the coil, relay contact 59 (FIG. 5A) is turned on.

Terminals Go to G3 and Ho to H2 are terminals that generate count signals SGo to SG6, respectively, during temperature measurement. Such 7-bit count signals SGo to SG6
is a 2-input AND gate (2
Each of the inputs is short-circuited) 68 to enter the temperature measurement circuit 69. The above 7-bit count signal output states [SGo to SG6] are all 0 states when measuring temperature, that is, they start from [00...0], [100...0], [010...
0], [110...0], etc., in binary notation. Terminal Bo is the count stop signal MTE
When the signal is input, the count-up operation is stopped.

As shown in detail in FIG. 6, the operation input section 61 includes switches corresponding to each key of the operation section 16 shown in FIG. 3. When the control signals SEo, SIo and SE2 from the microprocessor 60 arrive,
A signal potential is supplied to the first column line 70, second column line 71, and third column line 72 of each switch of the operating section 16, respectively. On the other hand, the first row line 7 of each switch of the operation section 16
The third through sixth row lines 78 enter an encoder 79 which converts each row line input into a 3-bit code and outputs it as input data signals SAo, SA1, SA2.

Therefore, the key operation status is determined by the control signals SEo, SIo
or SE2, and the encoded input data signals SAo, SA1,
SA2 will be output. The correspondence between each key and the input data signal is shown in FIG. 7A. As is clear from the figure, three keys correspond to one input data signal, and the microprocessor 60 inputs control signals SEo, SIo and
The synchronization relationship with SE2 is used to differentiate each of these three keys. The above input data signal is handled in the microprocessor 60 as a BCD code, and the correspondence relationship is shown in FIG. 7B.

As mentioned above, the display unit 15 is composed of a well-known fluorescent numeric display tube and its drive circuit, and uses the control signal SEo from the microprocessor 60 as the first digit selection signal, SE1 as the second digit selection signal, and SE2 as the second digit selection signal. is the third digit selection signal and SE3 is the fourth digit selection signal, while the display data signals SD1 to SD from the microprocessor 60 are
SD7 is used as each segment selection signal for each digit. Therefore, for example, if the display data signals SD1, SD3, SD4, SD5, and SD7 are present when the control signal SEo is present, the number "2" will be displayed in the second digit of the display. The display section 15 also uses the control signal SIo as a colon digit selection signal and the display data signal SD6 as a colon selection signal, and lights up the colon using both signals.

The initial state setting signal generating circuit 62 is a well-known circuit consisting of a diode and a capacitor, and detects the rise of the output voltage VD of the DC power supply unit 58 shown in FIG. 5A at the moment the microwave oven 10 is energized. Detects and generates initial state setting signal IR.

The temperature measurement circuit 69 includes a resistance ladder circuit 80, a broken line approximation circuit 81, a temperature output circuit 82, and a comparator 83, and the output signal of the comparator 83 is transmitted to the terminal Bo
The signal that enters becomes the MTE.

As is well known per se, the resistance ladder circuit 80 is formed by connecting resistors with resistance values R and 2R in a ladder shape, and connects resistors with resistance values R and 2R to 7 through an AND gate 68 for impedance conversion.
Bit count signals SGo to SG6 are inputted, and therefore, a stepped voltage VL as shown in FIG. 8 is outputted to its output terminal 84. That is, its output is -10V when the count signals SGo to SG6 are all 0 (-10V),
When all the voltages are 1 (0V), it becomes 0V, and as it is counted up in binary, it increases one step at a time from -10V. Therefore, the stepped voltage VL takes a total of 128 step values depending on the output states of the count signals SGo to SG6. The output states of the count signals SGo to SG6 corresponding to such 128 steps are processed in the microprocessor 60 as temperature information. That is, when the stepped voltage VL is -10V, the corresponding output state [00...0] is -20°C, and thereafter it increases by 1°C for each step, and the stepped voltage VL
When it reaches 0V, the corresponding output state [11...1] is processed as 107°C.

The broken line approximation circuit 81 is for approximating the stepped voltage VL, which changes almost linearly, to a specific curve using a broken line. That is, after the output of the infrared detection element 24 described above is subjected to appropriate compensation processing,
A temperature output MT appears from the temperature output circuit 82, which is compared with the stepped voltage VL. Therefore, as shown in FIG. 9, its characteristic is that it is not a straight line but a curved line (theoretically a 4th power curve) A. Therefore, by adjusting the circuit constants in the temperature output circuit 82, the output voltage at -20°C can be changed to -10V or 107°C.
Even if the output voltages are adjusted to 0V, the stepped voltage VL becomes almost a straight line B with respect to the temperature, and does not match the curve A except for two points at -20℃ and 107℃. A comparison error occurs between the two. Broken line approximation circuit 8
1, in order to minimize this error,
Step voltage with a linear relationship between temperature and output voltage
VL, that is, straight line B in Figure 9 is connected to three broken lines C1 (-10V
~-8V), C2 (-8V to -4V) and C3 (-4V to 0V)
to generate an output that approximates curve A.

FIG. 10 shows details of the broken line approximation circuit 81. The stepped voltage VL is inputted through an operational amplifier 90 for impedance conversion, and this input value is outputted to an output terminal 94 through any one of the first to third operational amplifiers 91 to 93.

The level of the first operational amplifier 91 is set so that it operates when the input value is -10V or more,
Similarly, the levels of the second and third operational amplifiers 92 and 93 are set to operate when the input value is -8V or higher and -4V or higher, respectively, and each operational amplifier 91, 92, and 93 operates within its respective operating range. ,
Together with the feedback resistance associated with each amplifier, each amplifier has an output characteristic that matches each of the broken lines C1, C2, and C3 shown in FIG. Furthermore, these operational amplifiers output -10V in their respective non-operating ranges, and therefore, due to the action of the OR circuit composed of diodes 94, 95, and 96, the stepped voltage VL, which is the input value, becomes -10V.
Between 10V and -8V, the curved line C1 characteristic corresponds to the range of -20℃ to 30℃, and between -8V and -4V, the curved line C2 characteristic corresponds to the range of 30℃ to 80℃.
Furthermore, between -4V and 0V, a broken line C3 characteristic corresponding to the range of 80°C to 107°C is obtained from each output terminal 94, and this output characteristic is approximated to curve A.

FIG. 11 shows details of the temperature output circuit 82. The infrared rays incident through the chopper 22 are converted into voltage by the infrared detection element 24, and the FETs 100, 1
Preamplifier 102 and operational amplifier 10 including 01
The signal is outputted through the main amplifier 104 including the main amplifier 3.
The waveform at the output point A of the main amplifier 104 is shown in FIG. 12A. In the same figure, the dashed line is the temperature of the food being cooked.
The solid line indicates when To is higher than the temperature Tc of the tipper 22 itself, and the solid line indicates when it is lower. As shown in the figure, these waveforms are almost sinusoidal waves, the frequency of which is 20Hz depending on the chopping speed by the chopper 22, and the absolute value is |To−− as described above.
It is proportional to Tc|.

The output of the main amplifier 104 is the synchronous rectifier circuit 10
5 and after being switched by the switching transistor 106 in the circuit,
It is smoothed by a smoothing section consisting of a resistor 107 and a capacitor 108. The above switching transistor 1
The switching operation of 06 is controlled by the output of the synchronization detection circuit 109. That is, the circuit is chipper 2
The photointerrupter 30 described above detects the period of 2.
and its output is −V2 as shown in Figure 12B.
Outputs a 20Hz rectangular alternating voltage that varies between volts and +V1 volts. The magnitudes of V1 and V2 are set larger than the maximum value expected for the output of the main amplifier 104. Therefore, the waveforms at the output point C of the switching transistor 106 and the output point D of the smoothing section are shown in FIG. 12, C and D, respectively.
It will be like this. Note that the absolute value of the waveform at output point D is proportional to |To-Tc|.

The output of the smoothing section is amplified again by an amplifier 111 including an operational amplifier 110, and then enters an adder circuit 112. The adder circuit 112 mainly includes the adder resistor 11
3, 114 and an operational amplifier 115.

The other input to adder circuit 112 is the output of chopper temperature detection circuit 116. That is, the circuit includes the aforementioned chopper temperature detection diode 31 and operational amplifier 117, and generates a DC signal proportional to the temperature of the chopper 22 itself in accordance with the characteristics of curve A in FIG. Therefore, from the adder circuit 112, the chopper 2
2 itself is removed, and an output voltage corresponding only to the temperature of the food is generated. This output voltage is nothing but the compensated temperature output MT as described above.

The temperature output MT is input to the comparator 83 (FIG. 5B), but such input is prohibited by the prohibition circuit 118 for a predetermined period of time at the beginning of the temperature operation. That is, in the same circuit, during non-temperature operation, diode 1
The capacitor 120 is charged via the transistor 66 (fifth
From Figure B), the -10V INH signal is connected to diode 121.
The charging path is cut off, so that the transistor is turned on only while the charge in the capacitor 120 is discharged through the resistor 122 and the transistor 123, and during this period the temperature output MT is -
It is forced to 10V. And, during this prohibition time, Chiyotsupa 2, which starts rotating at the same time as temperature operation starts.
2 is determined by the length of time (several seconds) until steady rotation begins.

Thus, the outputs of the polygonal line approximation circuit 81 and the temperature output circuit 82 are input to the comparator 83, the two outputs are compared, and when the output value of the former exceeds the output value of the latter, a signal MTE is generated. The microprocessor 60 outputs a 7-bit output signal SGo during one temperature measurement.
~The state of SG6 is changed from -20℃ to 107℃, and in this way it changes from −20℃ to 107℃.
The time required for one cycle to reach °C, that is, the step voltage VL is -
The time required for the voltage to change from 10V to 0V is extremely short, approximately 2 milliseconds, and therefore, the temperature of the food being cooked, that is, the value of the temperature output MT, is considered to be constant during this time. Therefore, for example, if the temperature of the food to be cooked is 90°C and the temperature is measured at this point, the temperature output MT is approximately -2.5V, and therefore the output of the broken line approximation circuit 81 is -2.5V. When the comparator 83 reaches
Output MTE is generated from microprocessor 60
immediately fixes the state of the 7-bit output signals SGo to SG6. That is, at this time [SGo~SG6]=
[0101101], and this state is processed within the microprocessor 60 as temperature information of 90°C.

FIG. 13 shows the inside of the microprocessor 60, which includes a control unit 200, an arithmetic unit 201,
It includes an accumulator 202, a random access memory (hereinafter referred to as RAM) 203, a RAM buffer 204, an input/output interface 205, etc., and information is exchanged between these parts via a data bus 206. Further, the control unit 200 controls the exchange of these information.

External input signals SAo, SA1, SA2, DOR, MTE
and external output signals SD1 to SD7, SEo to SE3, SIo,
Each of PO, BZ, TE, and SGo to SG6 is input/output via the input/output interface 205.

The microprocessor 60 further includes a basic clock signal generator 207, an interrupt control unit 208, and a reset unit 209, where the generator 207
Generates a 400KHz basic clock signal, unit 208 instructs interrupt processing for necessary timekeeping operation when time reference signal TB is input, and unit 209 instructs necessary interrupt processing when initial state setting signal IR is input. Instructs reset processing.

The control unit 200 is a read-only memory (hereinafter referred to as ROM) that stores control programs and constants.
) 210; a program counter for advancing each step of the control program;
It includes an instruction decoder and the like for decoding various instructions read from each step and executing the work.

The RAM 203 is used to store various data, and its storage area is shown in FIG. 14A. The storage area of the RAM 203 is associated with pages 0 to 3 and a 16-digit address of 0 to 9 and A to F for each page, and by specifying this page and digit, a specific storage area is specified. can do. RAM 203 also includes address registers for this purpose. RAM203 0-9,
Each digit A to F is 4 bits long.
Each area of DISPLAY, TIMER, and CLOCK has a length of 4 digits, and each digit stores a decimal number in BCD code. Each area of CNT1, CNT2, TEMPA, and TEMPB has a length of 2 digits, and each digit stores a decimal number in BCD code. PWRA, PWRB,
Each area of POWER, PWRD, RD, CNT3, and NKB has a length of one digit and similarly stores decimal numbers in BCD code. The FKB area is 1 digit long and stores 4 digits of information.
Store in bit code. TCNT is 2 digits long and stores information in 8 bits. Each of the KNF, CTL, and RF areas has a length of one digit, and the bit configuration thereof is shown in FIG. 14B. The control unit 200 mainly uses the RAM 203 to execute control, and the flowchart of the program stored in the ROM 210 is shown in the first part.
This is shown in Figure 5.

Next, various functions of the microwave oven of the present invention will be explained with reference to FIG. In addition, in the following explanation, RAM20
The notation for each address in 3 is [page, digit]. Therefore, for example, [2, 3] represents a 3-digit address on page 2.

Also, the microprocessor 60, ROM 210 and
RAM203 is simply a microprocessor,
They are called ROM and RAM.

[Start of electricity supply]

When the microwave oven is initially energized, the initial state setting signal IR described in Figure 5B is sent to the microprocessor, so the microprocessor automatically executes the control program into the [Initial] routine (Figure 15A). Set to A1 step.

In the A1 step, the entire contents of the RAM are cleared by writing 0 to the entire area of the RAM, and then the program moves to the A2 and A3 steps in sequence. In step A2, the RAM CLOCK is pressed to prepare for displaying the current time.
The contents of the area are moved to the DISPLAY area. In step A3, we also prepare to display the current time.
1 is written to the COL area.

The program then moves to step A4, where the microprocessor issues control signals SEo~
SE3 and SIo are generated sequentially, and display processing,
Performs key detection processing and colon reset processing.

For the above display processing, control signals SEo to SE3
The first display in the RAM DISPLAY area is synchronized with the occurrence of
Digits to 4th digits, that is, [0, 3], [0,
2], [0,1], and [0,0] are sequentially read out, converted into 7-bit codes, and sequentially output as display data signals SD1 to SD7.
At this time, as a so-called zero subless process, displaying unnecessary high-order zeros is prohibited, and only significant digits are displayed. Also, if (1111) as a redundant code is written in any digit in the DISPLAY area, a display data signal SD7 is generated, which is the second
As shown in Figure d, a negative sign is displayed in the digit above the most significant digit, and
If (0111) is written as a redundant code in any digit in the DISPLAY area, display data signals SD1, SD2, SD3, and SD7 are generated, and these are displayed as the letter F as shown in Figure 2e. bring about. When the control signal SIo is generated, the contents of the COL area of the RAM are checked, and if it is 1, the display data signal SD6 is generated.

Therefore, in step A4, the contents of the DISPLAY area of the RAM are displayed on the display section 15 in a time-division manner.
In this case, the contents of the DISPLAY area become the contents of the CLOCK area, and the colon is lit, so the current time is displayed.However, since the contents of the CLOCK area are cleared when power is started, the display section 15 shows 0:00. Is displayed.

On the other hand, the control signal SEo in step A4 above,
SE2 and SIo are included in the operation input section 61, so
At this point, if a key is operated on the operation unit 16, the corresponding input data signals SAo, SA1, SA2 are input to the microprocessor.

The microprocessor interprets the input data signal and if it corresponds to a numeric key.
Write 1 to the NK area of RAM and convert the 3-bit input data signal according to the conversion table in Figure 6B.
Convert it to BCD code and write it to the NKB area, and if it corresponds to the function key,
1 is written in the FK area of the RAM, and the input data signal is similarly written in the FKB area as a 4-bit code according to the conversion table shown in FIG. 6B.

As you can see from the explanation below, the A4 step constitutes one step that makes up the circular loop of the program.On the other hand, since key operations are performed manually, the operation duration is sufficient compared to the step transition time of the program. Therefore, the program passes through the A4 step many times during a key operation, but when the microprocessor detects a key operation, it writes 1 to the KE area of RAM at the first pass. Distinguish the subsequent passes from the first pass. That is, the microprocessor examines the contents of the KE area in the A4 step and determines if it is 1.
If so, even though it is a key operation state, such operation is judged to be the same as the first detected key operation, and 0 is written in the FK area and NK area of the RAM.

Also, if no key operation is performed at step A4, all 0s are written in the FK, NK, and KE areas of the RAM.

For the A4 step, the above control signal SIo
After the occurrence period, 0 is written to the COL area of the RAM and the colon reset process is performed.

After step A4, the program moves to step A5.

At step A5, it is checked whether the type of key operation at step A4 is a function key. That is, the contents of the FK area of the RAM are checked, and if it is 0, the process moves to step A2, and if it is 1, the process moves to step A6. In this case, it is assumed that there is no key operation at the A4 step, and the process returns to the A2 step. From now on, unless there is a function key operation, the program will be A2,
Cycle through steps A3, A4, and A5.

[Timekeeping processing]

When the time reference signal TB arrives at its terminal, the microprocessor interrupts all other execution processing at that point, performs time measurement processing in the [time measurement] routine (Figure 15B), and then resumes the above-mentioned interruption process. Return to the time step.

The [timekeeping] routine counts the number of arrivals of the 60 Hz time reference signal TB to create a second signal and a minute signal, and uses these minute signals to update the current time in the CLOCK area of the RAM. In the first step, B1 step, the contents of the CNT1 area of RAM are set to 1.
is added, and in the following step B2, the content of the CNT1 area is determined, and if it is not equal to 60, the process returns to the step at the time of interruption, and if it is equal, the process moves to step B3. In other words, moving to step B3 is 1
It means seconds have passed.

In step B3, 0 is written to the CNT1 area,
In the following B4 step, 1 is written to the SEC area of RAM, the elapsed 1 second is memorized, and the program continues.
Move to step B5.

In step B5, 1 is added to the CNT2 area of the RAM, and in the following step B6, the contents of the CNT2 area are checked, and if it is not equal to 60, the process returns to the step at the time of interruption, and if it is equal, it moves to step B7.
In other words, moving to step B7 means that one minute has passed.

At step B7, 0 is written to the CNT2 area,
In the following step B8, 1 is added to the CLOCk area of RAM. At this time, the first digit [0,
3] to the second digit [0, 2] is in decimal notation, and the carry from the second digit to the third digit [0, 1] is 6.
In decimal notation, the carry from the third digit to the fourth digit [0, 0] is carried out in decimal notation, and the next addition of 1 is performed with the contents of the CLOCK area indicating 12:59. and its contents return to the state showing 1:00. The program then returns to the step at which it was interrupted.

Therefore, in the (timekeeping) routine, the time reference signal TB
A clock operation is performed under the , and the CLOCK area of RAM updates the current time.

As is clear from the explanation of [Start of power supply] and [Time measurement process] above, when the microwave oven is turned on, all areas of the RAM are first cleared, and then the RAM
A timekeeping operation is performed in the CLOCK area, and its contents are displayed on the display unit 15. In this case,
Since no time adjustment has been made with respect to the contents of the CLOCK area, the display unit 15 displays the time measurement state from 0:00 after the start of energization.

[Time setting]

To adjust the display time on the display section 15, the CLOCK key on the operation section 16 is used. In other words, if you want to set the time to 2:00, just press the keys in the following order: CLOCK □2 □0 □0 CLOCK. The progress of the program will be explained below in accordance with the above key operation order.

The progress of the program will be explained below in accordance with the above key operation order.

As mentioned above, the program cycles through steps A2 to A5 of the [initial] routine.
When the CLOCK key is operated, this key operation is detected at step A5 and the process moves to step A6.

In step A6, the contents of the FKB area of the RAM are checked to see if the above operation key is the CLOCK key, and since it is the CLOCK key in this case, the process moves to the [CLOCK] routine.

[Clock] is the first step in the routine.
In the C1 step, all 0s are written to the TIMER area of RAM, its contents are cleared, and then
Move to C2 step and C3 step sequentially. In the C2 step, the contents of the TIMER area are moved to the DISPLAY area, and in the C3 step, 1 is written in the CCL area in preparation for displaying the current time. The program then moves to step C4, in which the process exactly the same as step A4 of the previously described [Initial] routine is executed, and then moves to step C5.

The C5 step examines the contents of the FK area of RAM,
If it is 0, go to C8 step, and if it is 1, go to C8 step.
Move to step C6. Since the key operation time on the operation unit 16 is sufficiently long compared to the progress of each step of the program on the microprocessor, the above-mentioned
When the CLOCK key operation moves to the [clock] routine, the key operation continuation state is stored in the KE area of RAM, so when exiting the C4 step, the contents of the FK area and NK area remain 0. be. Therefore, the program moves to step C8.
The C8 step examines the contents of the RAM NK area,
If it is 0, go to C2 step, and if it is 1, go to C2 step.
Move to C9 step.

Now, since the contents of the NK area are also 0, the program cycles through each step from C2 to C5 and C8. If the CLOCK key operation is no longer performed during this circulation process, the contents of the KE area become 0, so that any subsequent new key operation will be detected at step C4.

When the next number key □2 is operated, this key operation is detected at step C4, and the program proceeds through steps C5, C8, and C9. In step C9, the contents of each digit in the TIMER area of RAM are shifted by one digit toward the upper digit, and
The contents of the NKB area are the first digit [1,
3] and then moves to the C2 step.

Therefore, the program cycles through steps C2, C3, C4, C5, and C8 until there is a new key operation, and the contents of the TIMER area are displayed during the cycle. That is, the display state in this case is 0:02.

After that, when the number keys □0 and □0 are operated in the same way, the display state 2:00 representing 2:00 as the set time is obtained on the display section 15, and the program is also executed with C2, C3, C5, Cycle through each step of C8.

Finally, when you operate the CLOCK key again, this key operation is detected at step C4 and the program starts.
Move to C6 step via C5 step. In the C6 step, it is checked whether the current operation key is the CLOCK key by looking at the contents of the NKB area of the RAM, and if it is not the CLOCK key, the process moves to the C2 step, and if so, the process moves to the C7 step.

In the C7 step, the contents of the RAM TIMER area are
The program is moved to the CLOCK area, and the program then cycles through steps A2 to A5 of the [Initial] routine.

Therefore, if you operate the CLOCK key for the second time at the correct time of 2:00, the RAM will be cleared.
The CLOCK area is updated as time passes from 2:00, and the correct current time is displayed on the display section 15.

[Timer operation]

For example, 10 at 50% output value of maximum microwave output.
When running for minutes, keys are operated on the operation unit 16 in the order of TIMER □1 □0 □0 □0 POWER □5 START.

The program progress will be explained below in accordance with the above key operation order.

As mentioned above, the program cycles through the [Initial] routine A2 to A5, so when you operate the TIMER key, this key operation
It is detected at step A4, and moves to step A7 after passing through program steps A5 and A6. In step A7, the contents of the FKB area of the RAM are checked to see if the above operation key is the TIMER key, and since it is the TIMER key in this case, the program moves to the [timer] routine.

[Timer] D1, the first step of the routine
At step D2, all 0s are written to the TIMER area of RAM and its contents are cleared.
Move through each step of D3 in sequence. At D2 step
The contents of the TIMER area of RAM are moved to the DISPLAY area, 1 is written to the TM area of RAM in the D3 step, and the exact same processing as the A4 step of the [Initial] routine is executed in the D4 step.
Then move on to step D5.

In the D5 step, the contents of the FK area of RAM are checked, and if it is 0, the process goes to the D9 step, and if it is 1, then the
Move to step D6. Furthermore, in the D9 step, the RAM
Check the contents of the NK area, and if it is 0, proceed to step D2, and if it is 1, proceed to step D10.

When exiting the D4 step above, the contents of the Fk and NK areas of RAM are both 0 unless there is a new key operation, so the program will move to D2, D3, D4,
The process cycles through steps D5 and D9, and 0 is displayed on the display section 15.

Then, when the number key □1 is operated next, such operation will be detected in step D4 above, and the program will be executed.
After passing through steps D5, D9, D10, and D11, return to step D2. In step D10, the contents of each digit in the TIMER area of the RAM are shifted by one digit toward the upper digits, and the contents of the NKB area of the RAM are written into the first digits [1, 3] of the TIMER area.

At step D11, 1 is written in the SET area of the RAM to store that at least a one-digit timer value has been input.

From then on, the program cycles through steps D2, D3, D4, D5, and D9 again until there is a new key press.
During this cycle, the contents of the TIMER area are displayed.

After that, when the number keys □0, □0, □0 are operated in the same way, the timer setting time will be displayed on the display section 15.
A display state 1000 representing 10 minutes is obtained and the program cycles through steps D2, D3, D4, D5, and D9.

After that, there is a new key press, and if it is a function key press, the program will write D6, D7, etc.
After each step of D8, return to step D2. D6,
In steps D7 and D8, the contents of the FKB area of RAM are checked and the POWER key, START key or
The CLEAR key is checked, and if any of the above is true, the [Power] routine is executed immediately.
Move to the [Start] routine or [Clear] routine.

The new key operation in this case is the POWER key operation, so move on to the [Power] routine.

[Power] E1, the first step of the routine
In this step, the contents of the SET area of the RAM are checked, and if it is 1, the process moves to the E2 step, and if it is 0, the process moves to the E4 step. In the E2 step, the RAM
The contents of the TIMER area are checked, and if it is 0, the program moves to step E3, and if it is not 0, the program moves to step E5. In the E3 step, the contents of the TEMPA area of RAM are checked, and if it is 0, the E4 step is executed.
If it is not 0, move to step E5.

In the E4 step, the contents of the TM area are checked, and if it is 1, the process moves to step D2 of the [timer] routine, and if it is 0, the process moves to step K2 of the [temperature] routine.

Now, the content of the SET area is 1, and
The content of the TIMER area is set to 0 to represent 10 minutes.
Since it is not, the program moves to step E5.

In step E5, 0 is written to the DISPLAY area of RAM to clear its contents, and then
Move to steps E6 and E7 in sequence. In step E6, the contents of the POWER area are moved to the first digit [0, 3] of the DISPLAY area. At the E7 step, the process exactly the same as the A4 step of the [Initial] routine is executed, and then the program moves to the E8 step.

In the E8 step, the contents of the FK area of RAM are checked, and if it is 0, the process goes to the E11 step, and if it is 1, the process goes to the E11 step.
Move to step E9. Furthermore, in the E11 step, RAM
Check the contents of the NK area, and if it is 0, proceed to step E6, and if it is 1, proceed to step E12.

When exiting the above E7 step, the contents of the FK and NK areas of RAM are both 0 unless there is a new key operation, so the program will move to E6, E7,
The process cycles through steps E8 and E11, and 0 is displayed on the display section 15.

Then, when the next number key □5 is operated, such operation will be detected at step E7 above and the program will be executed.
After passing through steps E8, E11, E12, and E13, return to step E6. In step E12, the contents of the NKB area of RAM are written to the POWER area of RAM.
At step E13, 1 is written in the PWR area of the RAM to memorize that the output value has been set.

Thereafter, the program cycles through steps E6, E7, E8, and E11 again until a new key operation is performed, and the contents of the POWER area are displayed during the cycle.
That is, in this case, display state 5 indicating an output value of 50% is obtained on the display section 15.

After that, there is a new key operation, and if it is a function key operation, the program goes through steps E9 and E10 and returns to step E6. E9, E10
At each step, the contents of the FKB area of RAM are checked.
It is checked whether it is the START key or the CLEAR key, and if either is applicable, the process immediately moves to the [Start] routine or the [Clear] routine.

Since the new key operation in this case is the START key operation, the process moves to the [Start] routine.

[Start] This is the first step of the routine.
In the F1 step, the open/closed state of the microwave oven door 14 is checked. That is, if the signal DOR is present at the B1 terminal of the microprocessor at this point, the door is closed and the process moves to step F2, and if there is no signal DOR, the process moves to step F6.

In the F6 step, the contents of the RAM TM area are checked, and if it is 1, the [timer] routine is
Move to step D2, and if it is not 1, move to step F7. The F7 step examines the contents of the TP area of RAM, and if it is 1, the Temperature routine
Move to the K2 step, and if it is not 1, move to the L4 step of the [Decompress] routine.

Now, in the F1 step above, now door 14
Assuming that is closed, the program moves to step F2. In the F2 step, the contents of the RAM SET area are checked, and if it is not 1, the F6 step is executed.
If it is 1, move to F3 step. Now, 1 is written in the SET area when the D11 step of the [timer] routine passes, so the program moves to the F3 step.

At the F3 step, check the DF area of RAM and if the content is 1, go to the F8 step, and if it is 0, go to the F4 step.
Move to step. Now its content is 0, so F4
Move on to the step, and in this step the RAM is
The contents of the TEMPA area are examined and now they are 0, so we move on to the F5 step. At F5 step
It is checked whether the content of the TIMER area of RAM is 0 or not, and now it is the content representing 10 minutes,
Since it is not 0, move to F9 step.

In step F9, a signal PO is generated at the heating instruction output terminal F1 of the microprocessor. Therefore, at this point, the microwave output starts and the signal is
The microwave output state continues until PO runs out.

The program then passes through steps F10, F11, and F12, and reaches step F13. In the F10 step, 1 is written in the BSY area of the RAM to memorize that the microwave is in the output state. In step F11, the contents of the POWER area of RAM are moved to the PWRB area. Therefore, in this case, the PWRB area has
The value 5 representing the 50% output value has been entered.
At step F12, the number 10 is written to the PWRA area of RAM. In the F13 step, it is checked whether the contents of the DF area of the RAM are 1, and since they are not 1, the process moves to the F15 step. TM at F15 step
It is checked whether the content of the area is 1 or not, and since it is now 1, the process moves to step F16.

At the F16 step, the contents of the RAM TIMER area are
The process is moved to the DISPLAY area, and the following step F17 performs exactly the same process as step A4 of the [Initial] routine. Therefore, in this case, the contents of the TIMER area represent the timer setting time of 10 minutes, so the display state is displayed on the display section 15 at step F17.
1000 is obtained.

In the following F18 step, the contents of the BSY area of RAM are checked, and if it is 1, the F19 step is executed.
If it is 0, move to step F51. In the F51 step, the contents of the FK area are examined. In other words, if the subsequent new key operation is not a function key operation, the process immediately returns to step F13, and if it is a function key operation, the process goes through steps F52 to F55.
Return to step F13. At each step from F52 to F55, check the contents of the FKB area of RAM and press the TIMER key.
It is checked whether it is the TEMP key, CLEAR key, or START key, and if it corresponds to any of them, the process moves to the F56 step, F57 step, [Clear] routine, and [Start] routine, respectively.
In step F56, the contents of the TP area are checked, and if it is 1, proceed to step F13, and if it is 0, proceed to step D2 of the [timer] routine.

In the F57 step, the contents of the TM area are checked, and if it is 1, the process moves to the F13 step, and if it is 0, the process moves to the K2 step of the [temperature] routine.

Now, in step F18 above, the content of the BSY area is now 1, so the process moves to step F19, where the open/closed state of the microwave door 14 is checked in the same way as step F1, and if the door is open, the ] If you move on to the routine and close
Move to F20 step.

In the [Stop] routine, 0 is written to the BSY area of the RAM in the first step, G1 step, and in the following G2 and G3 steps, the signals PO and TE at the heating instruction output terminals F1 and Fo of the microprocessor are set. They will each disappear. That is, this stops the microwave oscillation. The program then returns to step F13.

Now, in the above F19 step, now door 14
Assuming that is closed, the program moves to step F20. The F20 step checks the elapsed seconds. In other words, the contents of the SEC area of RAM are examined,
If it is 0, go to F46 step, and if it is 1, go to F46 step.
Move to F22 step via F21 step.

In the F21 step, 0 is written to the RAM SEC area, and in the F22 step, the contents of the DF area are examined, and since it is now 0, the process moves to F24 step, in which the contents of the TM area are examined,
Now it is 1, so move on to step F43. F43
In this step, the contents of the TIMER area of RAM are subtracted by one second. In the following F44 step
It is determined whether the content of the TIMER area is 0 or not. If it is 0, the process moves to the [buzzer] routine, and if it is not 0, the process moves to step F45. In step F45, a [power control] routine as a subroutine is executed.

When the [Power Control] routine finishes executing, the program moves to step F46, where the
The contents of the FK area of RAM are checked, and if it is 0, the process returns to step F13, and if it is 1, the process moves to step F47. At step F47, new function operation stops by checking the contents of the FKB area of RAM.
It is checked whether it is a key or not, and if the SHOP key is operated, the process goes to the previously described [Stop] routine, and if not, the process goes to step F13.

Therefore, unless there is a new function key operation after that, the program will be F13, F15, F16~F20,
It circulates through each step of F46, and in the circulation process, it advances through each step of F21, F22, F24, F43 to F46 every second.

In the [power control] routine that is executed every second, the first step, H1 step, examines the DF area of RAM, and its contents are now 0.
Therefore, move to H3 step. In the H3 step, it is checked whether the output value has already been set. That is, the contents of the PWR area of RAM are examined,
If it is 1, go to step H4, and if it is 0, go back to step F46 of the [Start] routine. In this case, the content of PWR is 1, so move on to the H4 step.

In the H4 step, the contents of the PWR A area of the RAM are subtracted by 1, and in the following H5 step, it is checked whether the contents of the PWR A area are 0 or not. Move to step. In this case, the PWRA area has [Start]
10 is written in the F12 step of the routine, so the program moves to the H11 step.

In the H11 step, the contents of the PWRB area of the RAM are subtracted by 1, and in the following H12 step, it is checked whether the contents of the PWRB area are 0 or not. Return to step F46. In this case, PWRB
The output value 5 was written in the area at step F11 of the [Start] routine, so the program returns to step F46.

The program passes through the [power control] routine every second in the above circulation process, so the RAM
When the contents of the PWRB area become 0, that is, in the present case, 5 seconds after the start of execution of the [Start] routine, the process moves to step H13.

In step H13, the signal PO at the heating instruction output terminal F1 of the microprocessor is made to disappear.
That is, the microwave oscillation is thereby stopped.

The program then runs through the Start routine.
Return to step F46.

In the subsequent cycle of the program,
When the contents of the PWRA area of RAM become 0, that is, 10 seconds after the start of execution of the [Start] routine
Move to H6 step.

In the H6 step, 10 is written to the PWRA area of the RAM, and in the following H7 step, the contents of the DF area are checked, and since the contents are now 0, the process moves to the H9 step. In step H9, the contents of the POWER area of the RAM, that is, in this case, the output value 5, is written to the PWRB area, and in the subsequent step H10, a signal PO is generated at the heating instruction output terminal F1 of the microprocessor. The program then returns to step F46 of the Start routine.

Therefore, the program passes through the [power control] routine every second in the above circulation process, so that
One cycle is 10 seconds, and microwave oscillation is performed for only 5 seconds within one cycle, resulting in 50% output.

On the other hand, in such a circular process, the RAM
The contents of the TIMER area are decremented by 1 second, so when the contents become 0, that is, in this case,
After 10 minutes have elapsed from the start of execution of the [Start] routine, the program moves to the [Buzzer] routine at step F44. In the above circulation process,
The contents of the TIMER area are displayed at step F17.
This display content is nothing but the remaining time of the timer.

The first and second steps of the Buzzer routine, steps I1 and I2, eliminate the signals PO and TE at the microprocessor output terminals F1 and Fo. The program then proceeds through steps I3-I5. In the I3 step, a value 3 representing a buzzer duration of 3 seconds is written in the CNT3 area of the RAM. In the I4 step, a signal BZ is generated at the buzzer output terminal F3 of the microprocessor. At step I6, the contents of the TIMER area of RAM are moved to the DISPLAY area. In the following step I8, exactly the same processing as in step A4 of the [Initial] routine is executed. Next, in the I9 step, the RAM SEC
You can check the elapsed seconds by looking at the contents of the area. That is, if the content is 0, return to step I5; if the content is 1,
Move to step I10. At step I10, 0 is written to the SEC area. In the following I11 step, the RAM
The contents of the CNT3 area are decremented by 1 and continue
In the I12 step, the contents of the CNT3 region are examined,
If it is 0, go to I5 step, and if it is 0, go to I5 step.
Move to step I13. In step I13, the signal BZ at the buzzer output terminal F3 of the microprocessor is made to disappear.

Therefore, by starting the execution of the [buzzer] routine,
When the microwave oscillation stops, the buzzer is activated, and the program cycles through each step of I5, I6, I8, and I9. During this cycle, I10, I11,
After going through each step of I12, when the contents of the CNT3 area of the RAM become 0, that is, after 3 seconds have elapsed from the start of execution of the [buzzer] routine, the process moves to step I13 and the buzzer drive is stopped. The program then moves to the [CLEAR] routine.

[Clear] In the J1 step of the routine, the RAM
All areas except CLOCK, CNT1, and CNT2 are cleared, and the program then returns to step A2 of the [Initial] routine.

Therefore, unless there is a new key operation, the program cycles through each step of A2, A3, A4, and A5, and during the cycle, the current time is displayed on the display 15.
is displayed. That is, the microwave oven completes all of the above-mentioned timer operations and enters a standby state.

[Temperature operation]

For example, when operating at 50% of the maximum microwave output until the temperature of the food reaches 90℃,
On the operation unit 16, keys are operated in the order of TEMP □9 □0 POWER □5 START.

The program progress will be explained below in accordance with the above key operation order.

As mentioned above, the program cycles through the [Initial] routine and the routines A2 to A5, so when you operate the TEMP key, this key operation
Detected at A4 step, program is A5, A6,
After going through each step of A7, move on to step A8. In step A8, it is checked whether the above operation key is the TEMP key by checking the contents of the FKB area of RAM.
In this case, the TEMP key is pressed, so the program moves to the [Temperature] routine.

[Temperature] In the first step of the routine, K1 step, all 0s are written to the DISPLAY area of RAM to clear its contents, then K2,
Move to each step of K3 and K4 in sequence. In the K2 step, the contents of the TEMP A area of RAM are moved to the DISPLAY area [0, 3], [0, 2], in the K3 step, 1 is written to the TP area of RAM, and in the K4 step, the contents of the TEMP A area of the [Initial] routine are moved to the DISPLAY area [0, 3], [0, 2]. Exactly the same processing as the step is executed, and then the process moves to the K5 step.

Check the contents of the FK area of RAM in the K5 step, and if it is 0, proceed to the K9 step, and if it is 1, proceed to the K6 step.
Move to step. Furthermore, in the K9 step, the RAM
Check the contents of the NK area, and if it is 0, proceed to the K2 step, and if it is 1, proceed to the K10 step.

When exiting the above K4 step, the contents of the FK and NK areas of RAM are both 0 unless there is a new key operation, so the program will continue to the K2, K3,
After cycling through each step of K4, K5, and K9,
In this case, 0 is displayed.

Then, when the next number key □9 is operated, such operation will be detected in the above K4 step and the program will be executed.
After passing through steps K5, K9, K10, and K11, return to step K2. RAM TEMPA at K10 step
The contents of each digit of the area are shifted by one digit toward the upper digits, and the contents of the NKB area of the RAM are written to the first digit [0, 7] of the TEMPA area. In the K11 step, 1 is written in the SET area of the RAM to store that at least a one-digit temperature value has been input.

Thereafter, the program cycles through steps K2, K3, K4, K5, and K9 again until a new operation is performed, and in the process, the contents of the TEMP A area are displayed.

After that, when the number key □0 is operated in the same way, the display state 90 indicating 90°C as the set temperature is obtained on the display section 15, and the program is K2, K3, K4,
Cycle through each step of K5 and K9.

After that, there is a new key press, and if it is a function key press, the program will write K6, K7,
After each step of K8, return to K2 step.

At each step K6, K7, and K8, the contents of the FKB area of RAM are checked and the POWER key, START key, or
The CLEAR key is checked, and if any of the above is true, the [Power] routine is executed immediately.
Move to the [Start] routine or [Clear] routine.

In this case, the new key operation is the POWER key operation, so move on to the [Power] routine and store the RAM.
The SET area is 1, the TEMER area is 0,
Since it is not 0 in the TEMPA area, the program enters step E5. Therefore, at the time of key operation □5 following POWER, same as in the case of [timer operation] mentioned above.
Number 5 indicating the output value 50% in the POWER area of RAM
At the same time, 1 is written in the PWR area, and 5 is displayed on the display section 15.

The program cycles through steps E6, E7, E8, and E11, and when the START key is pressed, the program moves through step E9 to the [Start] routine.

When you enter the Start routine, the program starts
Proceed sequentially through each step of F1 to F4, then move on to step F8. In this step, a signal TE is generated at the output terminal Fo of the microprocessor. Therefore, the relay coil 67 is energized, the relay contact 59 is turned on, the chopper motor 31 is energized, and the chopper motor 2
2 starts rotating. On the other hand, the inhibit circuit 118 is activated by the signal INH, and the temperature is output MT for a predetermined time.
is fixed at −10V. This output value corresponds to -20°C, but of course is not the actual food temperature.

The program then moves to F9 step, where the microwave oscillation starts, and then F10
~Go through steps F13 and F15 and move on to step F14. In step F14, the contents of the TEMP B area [1, 7], [1, 6] of RAM are moved to [0, 3], [0, 2] of the DISPLAY area, and the contents of the RD area are moved to [0, 2] of the DISPLAY area. 0, 1].

After that, the program is F17, F18, F19, F20, F46, F13, F15,
It cycles through each step of F14 and enters step F21 every second during the cycle. After F21 step, F22 step, then F24 step, and now
Since the content of the TM area is 0, the process moves to step F23.

In the F23 step, 0 is written to all bits in the TCNT area of the RAM, and in the following F25 step, the contents of the TCNT area (excluding the most significant bit) are output to the microprocessor's output terminals Go~G3 and Ho~H2. Ru. That is, the 7-bit count signal SGo~
SG6 is output as [00 .

In the following step F26, the output signal of comparator 83
It is checked whether or not MTE is being output, and if there is no signal MTE, the process moves to step F27, and if so, the process moves to step F28. The temperature output of the current temperature output circuit 82 is -10V
Therefore, the signal MTE is generated, and therefore the process moves to step F28.

In step F28, the 8-bit contents of the TCNT area of the RAM are converted into a decimal number and written to the TEMPB area. That is, in this case, the content of the area is 0. In the following F29 step, 20 is subtracted from the contents of the TEMPB area, and the sign of the subtraction result is
is written to the RD area. That is, if the content of the RD area is a positive sign, it is expressed in binary (0000), but if it is a negative sign, it is (1111). Therefore, in this case, the content of the TEMP B area is 20, and the content of the RD area is the redundant value 15.

The program then moves to step F33, where it is checked whether the content of the DF area of the RAM is 1, and since it is now 0, the program moves to step F42. In the F42 step, the RAM TEMPB
The contents of the field, including its sign, are compared with the contents of the TEAPA field, and if the former is equal to or greater than the latter, go to the [Buzzer] routine, otherwise go to step F45. In this case,
Since the content of the TEMPA area (90°C) is larger, the program moves to step F45, where the [power control] routine is executed in the same way as [timer operation], and then passes through step F46 to step F13. Move.

The programs are F13, F15, F14, F17~
Each step of F20 and F46 is cycled, and every second during the circulation process, F21, F22, F24,
After passing through steps F23, F25, F26, F28, F29, F33, and F46, the power control routine of step F45 is performed, and microwave oscillation with 50% output is performed. Also, in the above circulation process, the contents of the TEMPB area are displayed together with a sign (only in the case of a negative value) at step F17. That is, in this case, the display state is -20. During this time, the microwave door 14
It is assumed that the is closed and the STOP key is not operated.

Thereafter, the prohibition by the prohibition circuit 118 is released. It has already been mentioned that it takes several seconds for such a ban to be lifted. Therefore, the temperature output MT corresponds to the correct temperature of the food to be cooked. If this temperature is now 30°C, the count signals SGo to SG6 still correspond to -20°C, so the signal from the comparator 83 is
MTE does not appear. Therefore, F26 of the above circular process
At step, the program moves to step F27 and then returns to step F25. At step F27, 1 is added to the TCNT area of RAM.

The program uses count signals SGo~SG6
Steps F25, F26, and F27 are cycled through until the current temperature of the food reaches a logic state of 30°C, and when the temperature of the food is reached, the process moves to step F28.

Similarly, in the F28 step, the binary number in the TCNT area is
It is converted to a decimal number and written to the TEMPB area,
In the following F29 step, 20 is subtracted from the contents of the TEMPB area, and the sign of the subtraction result is the RD of RAM.
written to the area. That is, in this case, TEMPB
30 is written to the area, and 0 is written to the RD area. The program then passes through steps F33, F42, F45, and F46, returns to step F13, and at step F17, the number 30 representing the temperature of the food to be cooked is displayed at 30°C.

The programs are F13, F15, F14, F17~
Each step of F20 and F46 is cycled, and during the circulation process, the temperature of the food to be cooked is measured and the measured temperature is compared with the set temperature. The [Power Control] routine is executed. The measured temperature is also displayed at step F17.

Then, when the temperature of the food reaches the set temperature of 90°C, it is detected in step F42 and the program moves to the [Buzzer] routine.

In the [buzzer] routine, as in the case of [timer operation], the microwave oscillation ends in step I1, and the signal TE disappears in step I2, and the chopper motor 31 also stops. The program then runs on I3,
Steps I4 and I5 are sequentially progressed, and in step I5, the contents of the TM area of the RAM are checked, and since it is now 0, the process moves to step I7. At step I7, the contents of the TEMP B area of RAM are displayed.
area and then to the I8 step.

Therefore, by executing the [Buzzer] routine, the buzzer is driven for 3 seconds as described above, and then, after passing through the [Clear] routine described above, the program executes steps A2, A3, A4, and A5 of the [Initial] routine. The current time is displayed on the display unit 15 during the circulation process. That is, the microwave oven completes all of the above-mentioned [temperature operation] and enters a standby state.

[Thaw operation]

To defrost frozen food, key operations are performed in the order of DEFROST START on the operation unit 16.

In addition, according to this thawing operation, the temperature of the food to be cooked is 3.
The point at which the temperature rises to ℃ is the midpoint of thawing, and the point when the temperature rises to 8℃ is the end of thawing.
Microwave oscillation is performed at 100% output and then at 20% output until the end of defrosting.

When thawing is performed using microwaves, the dielectric constants of ice and water are 2.2 and 2.2, respectively, assuming that the dielectric constant of air is 1.
77, so when partial thawing progresses, microwaves are intensively absorbed in the thawed water portion, which further promotes partial thawing, resulting in uneven thawing, which is undesirable. If defrosting is performed by reducing the microwave output, the occurrence of such uneven defrosting will be reduced, but the defrosting time will be significantly longer.

On the other hand, if thawing is performed in two stages as in the embodiment, an appropriate thawing state can be obtained in a short time. In other words, the food is rapidly thawed at high power until the temperature reaches 3℃, but the food is mostly frozen until it reaches this temperature, so partial thawing hardly progresses; As a result, water is generated due to partial thawing, and thawing is performed at low power until the proper thawing end temperature reaches 8°C.

As described above, in this embodiment, the defrosting process is carried out in a short time by using high output when there is no risk of uneven defrosting, and low output when there is a risk of it. The temperatures at the intermediate point and the end point of defrosting may be changed as appropriate.

The program progress will be explained below in accordance with the above key operation order.

As mentioned above, the program cycles through the routines A2 to A5 of the [Initial] routine. Therefore, when the DEFROST key is operated, this key operation is detected at step A4, and the program cycles through the routines A2 to A5 of the [Initial] routine.
After going through each step of A8, we reach step A9. In step A9, the contents of the FKB area of the RAM are checked to see if the above operation key is the DEFROST key, and if it is the DEFROST key, the process returns to the [defrost] routine, and if not, the process returns to step A2. In this case, the DEFROST key is pressed, so the program moves to the [Decompress] routine.

In the L1 step, which is the first step of the [Decompression] routine, all 0s are written to the DISPLAY area of the RAM, and the contents of this area are cleared.

The program then proceeds sequentially through each step from L2 to L6. In each step of L2 and L3, the RAM is
1 is written in each area of SET and DF. In the L4 step, the first digit [0,
3], a redundant value 12 for displaying the character F, ie, (0111) in binary representation, is written, and in the following step L5, the same processing as in step A4 of the [Initial] routine is performed. At L6 step
The contents of the FK area of the RAM are checked, and if it is 0, the process moves to the L4 step, and if it is 1, the process moves to the L7 step.

When exiting step L5, the contents of the FK area are 0 unless there is a new key operation, so the program cycles through steps L4, L5, and L6, and the display 15 displays F, which means DEFROST. Ru.

After that, there is a new key operation, and if it is a function key operation, the program goes through steps L7 to L10 and returns to step L4. L7, L8,
In each step L9 and L10, the contents of the FKB area of RAM are checked to see if it is a TIMER key, TEMP key, STMRT key, or CLEAR key. Temperature] routine, [Start] routine or [Clear] routine.

In this case, the new key operation is the START key operation, so move on to the [Start] routine.

In the [Start] routine, the program goes through the F1 and F2 steps in the same way, then moves to the F3 step. In this step, the contents of the DF area of the RAM are checked, and since it is currently 1, the program moves to the F8 step, and then goes through the F9 to F12 steps. Reach step F13. In the F13 step, the DF area of RAM is examined, and its contents are now 1
Therefore, move to the F14 step, and then proceed to F17~F20, F46, F13, F14 in the same way as each operation above.
Cycling through each step of the process,
RAM is updated every second in F21 step and then F22 step.
The contents of the DF area are examined and now it is 1, so we move to step F23. Thereafter, the program reaches step F33 in the same manner.

In the F33 step, the contents of the DF area of RAM are examined, and since it is now 1, the process moves to the F34 step. In step F34, it is determined whether the temperature corresponding to the contents of the TEMPB area of RAM is 8°C or higher.
If the temperature is 8°C or higher, proceed to the F35 step, and if it is lower than 8°C, proceed to the F37 step. At F37 step
It is determined whether the temperature corresponding to the contents of the TEMP B area is 3°C or higher, and if it is 3°C or higher, the process moves to step F38, and if it is lower than 3°C, the process moves to step F45.

Now the temperature output MT is -20 due to the function of the inhibition circuit.
Since this corresponds to ℃, the program passes through steps F34 and F37, then moves to step F45.
At this step, the [power control] routine is entered.

In the H1 step of the [Power Control] routine,
The contents of the RAM DF area are examined and now it is 1
Therefore, we move to step H2, and in this step
The contents of the DPWR area are checked, and if it is 1, go to step H4, and if it is 0, go to step F46. Now the content of the DPWR area is 0. A program moves to step F46 and from that step
Return to step F13.

Therefore, the program is F13, F14, F17~F20,
Each step of F46 is cycled, and in the circulation process, F20 step F21, F22, F23, F25, F26,
After each step of F28, F29, F33, F34, F37
The [power control] routine is entered at the F45 step, and since the routine moves directly from the H2 step to the F46 step, 100% output microwave oscillation is performed. In addition, in the above circulation process, TEMPB
The contents of the area are displayed along with the code at step F17.

That is, in this case, the display state is -20.

It is assumed that during this time, the door 14 of the microwave oven is closed and the STOP key is not operated.

When the prohibition by the prohibition circuit 118 is subsequently canceled, the temperature output MT corresponds to the correct temperature of the food to be cooked. Therefore, in the same manner as in the case of [temperature operation] described above, the temperature is measured once every second, and a comparison is made to see whether the measured temperature has reached 8°C or 3°C. However, the microwave output at this time is 100%. The measured temperature is also displayed at step F17, and if the temperature is negative, a negative sign is also displayed.

After that, when the temperature of the food reaches 3°C, the process moves from step F37 to step F38. In this step
The contents of the DPWR area of RAM are examined and it is
If so, go to step F45, and if it is 0, go to step F39. Now, since the content of the DPWR area is 0, the process moves to step F39, and thereafter passes through steps F40 and F41 to reach step F45. F39 and F40
At each step, the DPWR and PWRD of RAM are
1 and 2 are written to each area, and in step F41, the contents of the PWRD area are written to the PWRB area.

Therefore, in the [power control] routine entered at step F45, DPWR is set at step H2 after step H1.
It is determined that the content of the area is 1, and the process moves to the H4 step. Therefore, as is already clear, the program passes through the [power control] routine every second, so
When the contents of the PWRB area become 0, that is, in the present case, 2 seconds after the start of execution of the [Start] routine, the program moves to step H13, and the microwave oscillation stops at this step. and then in RAM
When the contents of the PWRA area become 0, that is, 10 seconds after the start of execution of the [Start] routine, the program moves from the H5 step to the H7 step, in which the contents of the DF area are examined, and it is now 1.
Therefore, move to step H8, and in this step
Content 2 of the PWRD area is written to the PWRB area again, and microwave oscillation is restarted in the following H10 step.

Therefore, once the temperature of the food to be cooked reaches 3°C, the process progresses from step F21 to step F29 in the same way once every second, and then from step F38 to step F45 through steps F33, F34, F37, and F38. Therefore, once every second, a temperature measurement is performed and a comparison is made to see whether the measured temperature has reached 8°C or 3°C, and microwave oscillation is performed at 20% power.
The measured temperature is also displayed at step F17.

Thereafter, when the temperature of the food to be cooked reaches 8°C, the process moves from step F34 to step F35, then moves to step F4 via step F36. At F35 step
0 is written to the DF area of RAM, and at the F36 step, the signal at the microprocessor's output terminal _F0 is
TE disappears.

The program continues by checking the contents of the TEMPA area in the F4 step, and since it is now 0, F5
Moving on to step F5, the contents of the TIMER area are examined, and since it is now 0, the process moves to the [Buzzer] routine.

In the [Buzzer] routine, the same processing as in the above-mentioned [Temperature operation] is executed, and then after passing through the [Clear] routine, the program cycles through steps A2, A3, A4, and A5 of the [Initial] routine.
During the circulation process, the current time is displayed on the display unit 15. In other words, the microwave oven is in the above [defrosting operation]
completes everything and enters standby mode.

[Combination of defrosting operation and timer operation] After defrosting frozen food, if you want to continue operating for 5 minutes at 80% of the maximum microwave output, set the DEFROST TIMER □5 on the operation unit 16. Key operations are performed in the order of □0 □0 POWER □8 START.

In such a case, it is now clear that after the above-mentioned [defrosting operation] is executed, the above-mentioned [timer operation] is executed.

[Combination of thawing operation and temperature operation]

After thawing the frozen food, the temperature of the food to be cooked will be 85℃ at 60% of the maximum microwave output.
When driving until , key operations are performed on the operation unit 16 in the order of DEFROST TEMP □8 □5 POWER □6.

In such a case, it is now clear that after the previously described [defrosting operation] is performed, the previously described [temperature operation] is performed.

As is clear from the above description, the present invention compares the measured voltage corresponding to the temperature of the heated object generated by infrared detection with the comparison temperature corresponding voltage, and calculates the temperature of the heated object based on the comparison result. In this case, the voltage measured by infrared detection is non-linear in the relationship corresponding to the temperature of the heated object, while the temperature-corresponding voltage for comparison is generally linear. In view of the problem that unless some measure is taken, a significant error will occur in the comparison between the measured voltage and the temperature-corresponding voltage for comparison, making it impossible to accurately determine the temperature of the heated object for heating control. The structure is such that the input/output characteristics related to the temperature-corresponding voltage are approximated to the above-mentioned measurement voltage, and the occurrence of the above-mentioned comparison error can be significantly suppressed. It is possible to realize the automatic cooking type cooking device using infrared detection at a popular price.

[Brief explanation of drawings]

Fig. 1 is an overview perspective view of the microwave oven of the present invention;
The figure shows the display form on the display section of the microwave oven, FIG. 3 is a detailed view of the operating section of the microwave oven, FIG.
The figure shows the electric circuit diagram of the microwave oven, Figure 6 is the detailed circuit diagram of the operation input section of the electric circuit, Figure 7 is the code conversion diagram, Figure 8 is the stepped voltage signal waveform diagram, and Figure 9 is the output. Voltage characteristic curve diagrams, Figures 10 and 11 are detailed circuit diagrams of the main parts of the above electric circuit, Figure 12 is a measured temperature curve diagram, Figure 13 is a detailed block diagram of the microprocessor, and Figure 14 is the same. FIG. 15, which is a diagram showing the RAM area of the microprocessor, is a program flowchart of the microprocessor. 60...Microprocessor.

Claims (1)

[Claims] 1 A heating energy generating means for supplying heating energy to a heated object, which receives infrared rays emitted from the heated object to generate a measurement voltage corresponding to the temperature of the heated object, and also generates a measurement voltage corresponding to the temperature of the heated object. The first type has input/output characteristics with a nonlinear relationship between measured voltage and
a second voltage generating means for generating a comparative temperature-corresponding voltage that approximates the input/output characteristics;
An electronically controlled cooking appliance comprising: control means for controlling the heating energy generating means based on a comparison result between the measured voltage and the comparison temperature voltage.