JP3600058B2 - Cooking device - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a cooking device, and more particularly to a cooking device that detects a state of food in a heating chamber using an infrared sensor.
[0002]
[Prior art]
Some cooking devices such as microwave ovens include an infrared sensor. In the heating cooking device, the food is placed on a turntable, which is an example of a food moving unit, in the heating chamber. The infrared sensor is configured to detect infrared rays emitted from the food in a field of view of the infrared sensor (a region where the infrared sensor can detect infrared rays). In the conventional cooking device, the temperature of the food is detected based on the infrared light detected by the infrared sensor, and the food is heated until the detected temperature reaches a predetermined food finishing temperature. I was
[0003]
[Problems to be solved by the invention]
However, in the conventional cooking device, the detection surface of the infrared sensor may be clouded with moisture radiated from food. Therefore, in the conventional cooking device, there is a case where the infrared sensor becomes difficult to detect the infrared ray as the heating of the food proceeds. When such a situation occurs, the temperature of the food is detected lower, and even though the heating of the food is progressing, the fact cannot be detected by the cooking device, so the food is excessively heated. There was a case. If the food is heated too much, not only does the finish of the cooking not satisfy the user, but also the food becomes hot and dangerous.
[0004]
The present invention has been made in view of such circumstances, and an object of the present invention is to provide a cooking device that does not excessively heat food.
[0005]
[Means for Solving the Problems]
The cooking device according to the present invention includes a heating chamber for storing food, a heating unit for heating the food in the heating chamber, an operation panel capable of setting a plurality of menus related to a heating operation of the heating unit, Food moving means for continuously moving food at a predetermined cycle in the heating chamber, and temperature detecting means for detecting the temperature of the food by detecting infrared rays radiated from the food in the heating chamber; and For the temperature of the food detected by the temperature detecting means, calculating means for calculating a representative value within the predetermined cycle, and calculating the representative value within the predetermined cycle for a certain time calculated by the calculating means, before the certain time the comparison result of the comparison means and the comparing means for comparing a representative value of a given period is representative representative value in the predetermined period of one round is within the predetermined period of one round earlier said A first storage unit that stores the number of times that the number has become lower than the first period. A second storage unit that stores the number of times that the number has become continuously lower than the representative value, and a control unit that controls a heating operation of the heating unit, wherein the control unit includes the first storage unit. When the number of times of storing becomes the first number, or when the number of times of storing of the second storage means becomes the second number, the number of times stored at that time is determined according to the set menu. It is characterized in that it is determined whether or not the heating operation performed by the heating means is to be terminated .
[0006]
According to the present invention, in the heating cooking device, if the comparison unit compares the detected temperature while causing the heating unit to heat the food, it is difficult for the temperature detection unit to detect infrared rays due to moisture or the like generated from the food. Even so, it can be inferred from the comparison result of the comparison means. Therefore, in the heating cooking device, it is possible to prevent the food from being excessively heated by making it difficult for the temperature detection unit to detect infrared rays.
[0007]
In addition, by further including the first storage unit and the second storage unit, even if the temperature detection unit becomes difficult to detect infrared rays due to moisture or the like generated from food in the cooking device, it is compared with the comparison unit. Can be more easily estimated from the comparison result of
[0008]
Furthermore, the heating cooking device can execute the heating cooking desired by the user.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an example of an embodiment of the present invention will be described with reference to the drawings. In the drawings, the same reference numerals indicate the same or corresponding parts.
[0010]
FIG. 1 is a perspective view of a microwave oven 100 according to one embodiment of the present invention. FIG. 2 is a simplified cross-sectional view showing the internal structure of the microwave oven 100 shown in FIG. Note that, in FIG. 1, an illustration of an exterior portion that covers the outer periphery of the microwave oven 100 and an upper surface of the heating chamber 17 are omitted to explain the internal structure of the microwave oven 100.
[0012]
Referring to FIGS. 1 and 2, microwave oven 100 includes infrared sensor 1 on the side of heating chamber 17. Thereby, the infrared sensor 1 is arranged so as to catch the infrared rays 25 emitted from the food 31 from obliquely upward through the detection holes 19.
[0013]
The magnetron 22 supplies a microwave into the heating chamber 17. Below the magnetron 22, a high-voltage transformer 33 for supplying a high voltage to the magnetron 22 is arranged. Above the heating chamber 17, a heater 80 for heating the food 31 is arranged. The cooling fan 35 is provided for cooling the magnetron 22, the heater 80, or peripheral devices (including the infrared sensor 1) whose temperature has increased due to the heat of the heating chamber 17.
[0014]
A door 15 is attached to the front of the heating chamber 17. An operation panel 34 for the user to set a cooking menu is attached to the side. Further, a control unit 90 that controls each device of the microwave oven 100 is provided on the back of the operation panel 34. The control unit 90 includes a microcomputer. The operation panel 34 includes a display unit 3 that displays information and the like input by the user.
[0015]
A turntable 18 for placing the food 31 is provided at the bottom of the heating chamber 17, and a turntable motor 505 for rotating the turntable 18 is provided below the bottom of the heating chamber 17.
[0016]
FIG. 3 is a block diagram showing a main electrical configuration of microwave oven 100 shown in FIGS. Referring to FIG. 3, microwave oven 100 includes infrared sensor 1, turntable motor 505, magnetron 22, operation panel 34, heater 80, and control unit 90.
[0017]
In the microwave oven 100, when heating is performed by the magnetron 22, the infrared sensor 1 detects infrared rays emitted by the food 31. Then, the control unit 90 determines the temperature of the food 31 based on the infrared rays detected by the infrared sensor 1.
Here, the change of the temperature of the food 31 (hereinafter, abbreviated as detected temperature) determined by the control unit 90 based on the infrared light detected by the infrared sensor 1 with the elapse of the heating time will be described with reference to FIG. I do.
[0018]
First, referring to FIG. 4 (A), when infrared sensor 1 is in a state where it can normally detect the temperature of food, the detected temperature increases with the heating time. Then, when the detected temperature reaches the finishing set temperature, the control unit 90 stops heating by the magnetron 22. The finish set temperature is determined by a menu or the like set on the operation panel 34.
[0019]
Next, a case where the infrared sensor 1 is in a state where the temperature of the food cannot be normally detected will be described with reference to FIGS. 4B and 4C.
[0020]
When the food 31 is heated in the heating chamber 17 when the environmental temperature in which the microwave oven 100 is installed is lower than the temperature in the heating chamber 17, moisture generated from the food 31 is condensed near the detection hole 19. May be. In such a case, the infrared sensor 1 cannot detect infrared rays emitted from the food 31 sufficiently. That is, as shown in FIG. 4 (B), immediately after the start of heating, the detected temperature rises with the elapse of the heating time, but the heating time elapses to some extent, and moisture generated from the food 31 condenses around the detection hole 19. When it starts, the detected temperature becomes almost constant. Here, the reason why the detected temperature is substantially constant is that the infrared sensor 1 cannot detect the food 31 even though the temperature of the food 31 has risen with the elapse of the heating time.
[0021]
Further, when the dew condensation in the vicinity of the detection hole 19 is severe, as shown in FIG. 4C, the detection temperature temporarily rises to a certain temperature, but after that, although the heating is continued, The detected temperature decreases.
[0022]
When the microwave oven is in the state described with reference to FIGS. 4B and 4C, conventionally, even if the temperature of the food 31 has reached the finishing set temperature, it is not detected, The heating of the food 31 was continued. Therefore, there was a danger that the food 31 was heated more than necessary, or the food 31 was carbonized and fired.
[0023]
In the microwave oven 100 according to the present embodiment, when the detected temperature of the infrared sensor 1 is in the state shown in FIG. 4B or FIG. 4C, the detected temperature at that time is set to the finish set temperature. , The heating by the magnetron 22 is stopped or the heating in the microwave oven 100 is advanced to the next step. Hereinafter, this will be specifically described. To advance the heating to the next step in the microwave oven 100 means, for example, as a cooking menu, the food 31 is heated by the magnetron 22 until the finished set temperature is reached, and then the heater 80 is heated for a certain time. If it is set, it means that the heating of the magnetron 22 is ended and the heating by the heater 80 is started.
[0024]
The microwave oven 100 detects whether the detection temperature of the infrared sensor 1 corresponds to any of FIGS. 4A to 4C. In this detection, every time the turntable 18 makes one rotation, the maximum value or average value of the detected temperature is calculated, and the maximum value or average value calculated at a certain time is compared with the maximum value or average value calculated immediately before. By doing so. Here, the reason why the maximum value or the average value of the detected temperatures is to be compared will be described.
[0025]
When the waveforms of the detected temperatures shown in FIGS. 4A to 4C are enlarged, as shown in the circles in the drawings, the waveforms have a predetermined number of peaks for each rotation period t of the turntable 18. It has been changing finely. This is because the turntable 18 rotates. This will be described with reference to FIG. FIG. 5 is a view of the inside of the heating chamber 50 as viewed from above.
[0026]
In FIG. 5, reference numeral 99a denotes a field of view of the infrared sensor 1 on the turntable 18. The food 31 is partially included in the visual field 99a. Then, when the turntable 18 rotates, the volume of the portion of the food 31 included in the visual field 99a changes. In addition, when the temperature of the food 31 is substantially the same, when the volume of the portion included in the visual field 99a is large, the detected temperature is higher than when the volume is small. As a result, the waveform of the detected temperature is finely changed so as to have a predetermined number of peaks for each rotation cycle t of the turntable 18. The predetermined number of peaks corresponds to the number of foods 31 placed on the turntable 18. FIGS. 4 and 5 show, as an example, a case where the number of foods 31 placed on the turntable 18 is “1”.
[0027]
Next, a specific method for comparing the maximum value or the average value of the detected temperatures will be described.
[0028]
In the case of the waveform shown in FIG. 4A, the maximum value or the average value of the detected temperature is always larger than the previously calculated maximum value or the average value of the detected temperature.
[0029]
In the case of the waveform shown in FIG. 4B, the maximum value or the average value of the detected temperature is larger than the previously calculated maximum value or the average value of the detected temperature until the heating time elapses to some extent. In other words, when the heating time elapses to a certain extent, the size increases or decreases.
[0030]
In the case of the waveform shown in FIG. 4C, the maximum or average value of the detected temperature is larger than the previously calculated maximum or average value of the detected temperature until the heating time elapses to some extent. , And after a certain amount of heating time, it becomes smaller.
[0031]
Therefore, in the microwave oven 100, the control unit 90 calculates the maximum value or average value (current value) of the detected temperature, and replaces the maximum value or average value calculated at a certain time with the previously calculated maximum value or average value. (Previous value). The control unit 90 stores the comparison result in a built-in memory. The comparison result includes the number of times that the current value is continuously lower than the previous value (the number of consecutive drops) and the cumulative number of times that the current value is lower than the previous value (the number of cumulative drops). When the number of continuous drops is “5” or the number of cumulative drops is “3”, the control unit 90 stops heating by the magnetron 22 or stops heating in the microwave oven 100. The process proceeds to the next step (hereinafter, execution of control such as stopping heating by the magnetron 22).
[0032]
Here, the case where the number of continuous drops is “5” corresponds to the case where the detected temperature draws a waveform as shown in FIG. 4C, and the case where the cumulative number of drops is “3”. Is considered to correspond to the case where the detected temperature draws a waveform as shown in FIG.
[0033]
If the current value is continuously lower than the previous value by 2 to 4 times, the cumulative number of reductions is stored as “2”. In this case, since the number of continuous reductions is “2” to “4”, if the current value is lower than the previous value, the control unit 90 executes control such as stopping heating by the magnetron 22. It is.
[0034]
If the current value is five times higher than the previous value in succession, the storage of the cumulative number of reductions is cleared. In such a case, although the infrared sensor 1 is operating normally, it can be considered that the number of cumulative reductions up to that time has been counted due to the influence of external noise, output fluctuation of the magnetron 22, and the like. .
[0035]
Further, as described above, in the microwave oven 100, the control unit 90 executes the control such as stopping the heating by the magnetron 22 by the fact that the stored value of the number of continuous drops or the number of cumulative drops in the memory has reached the predetermined value. It is a condition. Here, the reason why the condition values of the continuous decrease frequency and the cumulative decrease frequency are different is as follows.
[0036]
Since the number of continuous drops is a continuous number, when the same value as the condition value for the number of cumulative drops is considered, it is considered that the number of continuous drops reaches the condition value is faster than the number of cumulative drops reaches the condition value. Therefore, in order to balance these, the condition value of the continuous decrease number is set to be larger than the condition value of the cumulative decrease number. Thus, even when the detected temperature draws a waveform as shown in FIG. 4 (B), the food 31 is kept in the same amount of time as when the detected temperature draws a waveform as shown in FIG. 4 (C). Heated.
[0037]
The reason why the detected temperature draws a waveform as shown in FIG. 4B or FIG. 4C is considered to be mainly due to dew condensation near the detection hole 19. Therefore, it is considered that the comparison of the maximum value or the average value of the detected temperatures described above is preferably performed after the food 31 reaches a temperature at which the moisture generated by the food 31 condenses. This is considered to be particularly preferable for a case where a food whose temperature rises slowly at the start of heating, such as a frozen food or a food having a large volume, is used as the food 31. That is, in such a case, when the comparison of the maximum value or the average value of the detected temperatures is performed from the time when the food 31 is at a low temperature, that is, at the time of starting the heating, the detected temperature at the start of the heating becomes as shown in FIG. This is because a control such as stopping the heating by the magnetron 22 or the like is executed even though the infrared sensor 1 is operating normally because the illustrated waveform is drawn.
[0038]
FIG. 6 shows the comparison operation of the detected temperature in the control unit 90 of the microwave oven 100 described above.
[0039]
Referring to FIG. 6, the control unit 90, the heating by the magnetron 22 is started, first, in S1, the detected temperature is judged whether the host vehicle has reached the finishing temperature setting. If it is determined that the time has arrived, the process ends. When this process is completed, the control unit 90 executes control such as stopping the heating by the magnetron 22 described above.
[0040]
On the other hand, if it is determined that the detected temperature has not reached the finishing set temperature, it is determined in S2 whether the detected temperature has reached a predetermined temperature. Here, the predetermined temperature is a temperature at which the moisture generated by the food 31 condenses, for example, 60 ° C.
[0041]
When it is determined that the detected temperature has not reached the predetermined temperature, the process returns to S1, and when it is determined that the detected temperature has reached, the turntable 18 is turned on in S3 since the heating is started or the process of S4 was previously executed. It is determined whether or not one round has been made. If it is determined that the vehicle has not made one round, the process returns to S1.
[0042]
In S4, the control unit 90 calculates the maximum value or the average value of the detected temperatures in the period in which the turntable 18 has made one round, stores the maximum value or the average value in the memory, and proceeds to S5.
[0043]
In S5, the control unit 90 determines whether or not the maximum value or the average value of the detected temperatures calculated this time is smaller than the maximum value or the average value of the detected temperatures during the previous round of the turntable 18. If it is determined that the current maximum value or average value is larger than the previous maximum value or average value, the process proceeds to S10. On the other hand, if it is determined that the current maximum value or average value is smaller than the previous maximum value or average value, the process proceeds to S6.
[0044]
In S6, the control unit 90 determines whether or not the number of continuous drops described above (“C1” in FIG. 6) is 0. If it is not 0, the process proceeds to S7, and if it is 0, the process proceeds to S8. Then, in S7, the number of continuous drops stored in the memory is incremented by 1, and the cumulative number of drops ("C2" in FIG. 6) stored in the memory is set to "2", and the process proceeds to S9. In S8, the number of continuous drops and the number of cumulative drops stored in the memory are both incremented by 1, and the process proceeds to S9.
[0045]
In S9, the control unit 90 determines whether or not the number of continuous drops and the number of cumulative drops stored in the memory have reached the above-mentioned condition value. Return to
[0046]
On the other hand, in S10, the control unit 90 sets (clears) the number of continuous drops to "0", and proceeds to S11. In S11, it is continuously determined that the determination of No in S5 has been performed a predetermined number of times consecutively, that is, that the currently calculated maximum value or average value is larger than the previously calculated maximum value or average value. It is determined whether or not the number of times has been determined. The predetermined number of times is five times in the present embodiment. If it is determined that the determination of No in S5 has been performed a predetermined number of times in a row, the cumulative decrease number is set to “0” (cleared), and the process returns to S1. If it is determined that the determination of No in S5 has not been performed continuously for the predetermined number of times, the process returns to S1.
[0047]
In the present embodiment described above, the control unit 90 compares the currently calculated maximum value or average value with the previously calculated maximum value or average value. However, the control unit 90 does not necessarily need to compare with the previously calculated maximum value or average value. There is no. That is, if the detected temperature is such that the waveform shown in FIG. 4B or FIG. 4C is detected, the processing speed of the control unit 90 and the rotation cycle of the turntable 18 may be considered. The comparison may be made with the maximum value or the average value calculated two times before, three times before, or the like.
[0048]
In the present embodiment described above, the representative value is constituted by the maximum value or the average value of the detected temperatures to be compared. Note that the representative value may be a minimum value of the detected temperature in the rotation cycle of the turntable 18 as long as the change range of the detected temperature in each rotation cycle of the turntable 18 can be compared. Is also good.
[0049]
In the present embodiment described above, the number of times of storage in the first storage means is configured by the cumulative number of reductions, and the number of times of storage in the second storage means is configured by the number of continuous reductions.
[0050]
Further, in the present embodiment described above, when the detection temperature of the infrared sensor 1 becomes a state as shown in FIG. 4B or FIG. Even if the detected temperature has not reached the finishing set temperature, control such as stopping heating by the magnetron 22 is executed. In the control such as the stop of the heating by the magnetron 22, whether to stop the heating by the magnetron 22 or to advance the heating in the microwave oven 100 to the next step is determined according to the cooking menu set on the operation panel 34. You. With this, the control means sets the number of times the first storage means stores the first number or the number of times the second storage means stores the second number. It is disclosed that, in accordance with the performed menu, it is determined whether or not to end the heating operation which is being executed by the heating means at that time.
[0051]
The embodiments disclosed this time are to be considered in all respects as illustrative and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.
[Brief description of the drawings]
FIG. 1 is a perspective view of a microwave oven according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view schematically showing the internal structure of the microwave oven shown in FIG.
FIG. 3 is a block diagram showing a main electrical configuration of the microwave oven shown in FIGS. 1 and 2;
4 is a diagram for explaining a change in the temperature of food 31 determined by a control unit based on infrared rays detected by an infrared sensor of the microwave oven in FIG. 1 with the elapse of a heating time.
5 is a view of the inside of the heating chamber of the microwave oven of FIG. 1 as viewed from above.
FIG. 6 is a diagram for explaining a comparison operation of a detected temperature in a control unit of the microwave oven in FIG. 1;
[Explanation of symbols]
Reference Signs List 1 infrared sensor 17 heating chamber 18 turntable 19 detection hole 22 magnetron 31 food 90 control unit 100 microwave oven

Claims (1)

A heating chamber for storing food,
Heating means for heating the food in the heating chamber,
An operation panel capable of setting a plurality of menus related to the heating operation of the heating unit,
Food moving means for continuously moving the food in the heating chamber at a predetermined cycle,
By detecting infrared rays emitted from the food in the heating chamber, a temperature detection unit that detects the temperature of the food,
For the temperature of the food detected by the temperature detecting means, calculating means for calculating a representative value within the predetermined cycle,
Comparison means for comparing a representative value within the predetermined cycle of a certain cycle calculated by the calculation means with a representative value within the predetermined cycle before the certain cycle.
A first storage for storing the number of times that the comparison result of the comparing means has become lower than a representative value in the predetermined cycle before the certain cycle in the predetermined cycle. Means,
The comparison result of the comparing means stores the number of times that a representative value in a certain cycle in the predetermined cycle is continuously lower than a representative value in the predetermined cycle before the certain cycle. Two storage means,
Control means for controlling the heating operation of the heating means,
The control unit, when the number of times stored in the first storage unit has reached the first number, or when the number of times stored in the second storage unit has reached the second number, A heating cooking device, which determines whether or not to end the heating operation currently being executed by the heating means at that time according to the menu that has been set .

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