JPH0480523A - Microwave oven - Google Patents

Abstract

PURPOSE:To improve a finished state of rice cooking by a method wherein when a temperature increasing degree set by an infra-red ray temperature sensor does not follow temperature of water and rice in a container, it is judged that a rice bowl has a lid, a heater-heating means is allowed and in turn when a temperature increasing degree follows the temperature within the container, it is judged that the lid is a resin film and then the heater heating means is prohibited. CONSTITUTION:When a lid 16 is applied to a rice bowl 15, an infra-red ray temperature sensor 10 receives an infra-red ray from the lid 16, so that its detected temperature increasing range (t2 - t1) is not followed to a rice temperature and a water temperature and is reduced. Accordingly, a control part 14 performs a denying judgement and judges that this has a lid 16 and then a driving of a hot air circulating device 9 is allowed for driving of a hot air circulation device 9. As a lid of resin film 17 is set on a bowl 15, a sensing temperature increasing range with an infra-red ray temperature sensor 10 follows a rice temperature and a water temperature in the bowl 15 and the temperatures reach a predetermined range at the beginning of heating operation, so that the control part 14 judges affirmatively that the lid is of the resin film 17 and then a driving of the hot air circulation device 9 is prohibited for a subsequent heating operation.

Description

[Detailed description of the invention] (Industrial application field The present invention relates to a microwave oven for cooking rice, etc.

(Rono Conventional Techniques M・i Patent Application No. 1-334204 shows a configuration for cooking rice in a microwave oven. This rice cooking involves placing rice and an appropriate amount of water in a bowl made of dielectric material. .

This can be easily carried out by storing this bowl in a heating chamber and supplying microwaves into the heating chamber. The above-mentioned rice cooking process generally includes a water absorption process, a boiling process, a boiling sustaining process, a shading process, etc. In the following two processes, boiling sustaining and shading, heating by a heater is used in combination with microwave heating. If heater heating is used instead of wave heating, the quality of cooked rice will improve.

By the way, it is desirable to be able to cook rice even if the above-mentioned bowl is covered with a resin film in addition to the common benefits, but if the lid is covered with a resin film, the heat will be absorbed when the heater is heated during the rice cooking process. The resin film will melt and the quality of the cooked rice will deteriorate.

(c) Problems to be Solved by the Invention The present invention improves the quality of rice cooking by applying heater heating in addition to microwave heating when cooking rice in a container such as a bowl. When cooking rice with a lid on a container, for example, with a resin film, this is to prevent the lid from melting and resulting in poor cooked rice.

(d) Means for Solving the Problems The microwave oven of the present invention includes a heating chamber for storing food in a container with a lid closed, a microwave heating means and a heater heating means for heating the food. and an infrared temperature sensor that receives infrared rays from the lid, and a control means, the control means having an infrared temperature sensor that determines whether or not the degree of temperature rise measured by the infrared temperature sensor at the beginning of heating has reached a predetermined value. one means; a second means for prohibiting the driving of the heater heating means in subsequent heating if the first means makes a positive determination; and when the first means makes a negative determination;
(e) When cooking rice in a container such as a rice bowl, for example, the heat capacity of the common rice has an influence - The degree of temperature rise j= determined by the infrared temperature sensor that receives infrared rays from one lid does not directly follow the temperature of the rice and water in the container. A negative judgment is made.

This automatically determines that the lid is a common property.
That means that. Then, the third means is allowed to drive the heater heating means in subsequent heating, and rice is cooked by applying heater heating in addition to microwave heating, improving the quality of rice cooking.

- When cooking rice with a lid on a container such as a bowl, for example, with a grease-resistant lume, the degree of temperature rise measured by the infrared temperature sensor is large, following the temperature of the rice and water in the container, and the heating The predetermined value will be reached at the beginning, and the first
An affirmative judgment is made based on the means. This means that it has been automatically determined that the lid is a resin film.

Then, the second means prohibits the heater heating means from being driven during subsequent heating, thereby preventing a situation in which the lid melts and the rice is not cooked well.

(F) Embodiment FIG. 1 shows the front of a microwave oven according to an embodiment of the present invention, in which a door 2 and an operating section 3 are provided on the front of a microwave oven main body 1. This operation unit 3 has a plurality of menu keys 4.4...
, a start key 4a, etc.

2 and 3 show the internal structure of the microwave oven,
A heating chamber 5 is formed within the microwave oven main body 1. In this heating chamber 5, microwave heating of the food is carried out using microwaves supplied from a microwave heating means, that is, a magnetron 6, and a heater heating means, that is, a hot air circulation device 9 consisting of a heater 7 and a fan 8, is used to heat the food. Hot air heating of the food is performed using the supplied hot air. An infrared temperature sensor 10 that receives infrared rays from the food portion is provided on the outside of the upper wall 5a of the heating chamber 5, and a thermistor that detects the temperature inside the heating chamber 5 is provided on the side wall 3b of the heating chamber 5. 11, and an absolute humidity sensor 13 for detecting the humidity inside the heating chamber 5 is provided in the exhaust path 2 of the heating chamber 5.

FIG. 4 shows a circuit of the microwave oven, in which a control section 4 consisting of a microcomputer or the like is provided for controlling the microwave oven. The control section 14 inputs operation information from the operation section 3 and detection information from the infrared temperature sensor 10, thermistor 11, and absolute humidity sensor 13, and based on these information, the magnetron 6 and the hot air circulation device 9
control the drive of the

Therefore, when cooking rice with a small amount of rice (<8 og), approximately 1□72 cups, use this small amount of rice and an appropriate amount of water (120 c).
c) is placed in a bowl 5 made of a dielectric material as shown in FIGS. 2 and 3, and a common dish 16 made of the same dielectric material is placed in the heating chamber 5.

Then, the user operates the rice cooking menu key 4 on the operation unit 3 and operates the start key 4a. Then, the control section 14 performs rice cooking control based on the control program built into itself.

FIG. 5 shows the flow of this control program. First, in step S1, the control unit 14 specifies a microwave output of 280 W and a time of 2 minutes for the first water absorption process, and outputs the microwave output of 280 W. The magnetron 6 is driven and controlled as much as possible, and in step S2, the time 2 minutes is waited for to elapse. During this time, the infrared temperature sensor 10
The temperature t1 when seconds have passed and the temperature t2 when two minutes have passed are detected.

When the temperature t2 is detected, the above-mentioned time of 2 minutes passes, and as this time elapses, the control section 14 then executes step S3. In the same step, the control unit 14 determines whether the degree of temperature rise detected by the infrared temperature sensor 10 at the beginning of heating by the magnetron drive has reached a predetermined value. Specifically, from the time when the above 10 seconds have passed, 2
It is determined whether the detected temperature increase width FI2-11) has reached a predetermined width of 18° C. during the required time of 1 minute and 50 seconds until the minute elapses.

Here, if the rice bowl 15 has a common benefit of 16 as mentioned above,
The infrared temperature sensor 10 is in a state where it receives infrared rays from the common benefit 16, and in both cases, the heat capacity of the MIG is the influence L, and the temperature rise range detected by the infrared temperature sensor 10 (t2-+11i
does not directly follow the temperature of the rice and water in the bowl 15, but is small as shown by the broken line in Figure 6, and at the beginning of heating, the temperature is 18°C.
does not reach.

Therefore, in the present case, the control section 14 makes a negative determination in step S3. At this time, the lid placed on bowl 15 is common interest 16.
It is automatically determined that this is the case.

When such a determination is made, the control unit 14 allows the hot air circulation device 9 to be driven in the subsequent heating, as will be understood from the following explanation.

First, in step S4, the control unit 14 sets the microwave output to 90°, the time to 8 minutes, and the temperature to 50° for the second water absorption step.
-1 With this microwave output of 90W, the magnetron 6 is driven and controlled so that the temperature detected by the infrared temperature sensor 10 is maintained at 50°C, and in the next step S5, the above-mentioned time of 8 minutes has elapsed. wait. At this time, rice is 60-65
It is maintained at ℃ to promote water absorption of rice.

After this time period has elapsed, the control unit 14 continues to operate the S6 stenopan with a microwave output of 500 W for the boiling process.
A temperature of 95° C. and a voltage of 1 V are specified, and the magnetron 6 is driven and controlled to output this microwave output of 500 to 50 V. The control unit 14 then performs the following steps in steps S7 and S8.
Wait for the temperature detected by the infrared temperature sensor 1o to reach the above-mentioned temperature of 95°C, and wait until the detected temperature of the absolute humidity sensor 13 (
Wait for the temperature (pressure) to rise by IV-41 from the value at the time of detection of the temperature t,1.

When the temperature reaches 95°C or increases by 1V, the control unit 14 in the next 89 steps increases the microwave output of 250W for the boiling sustaining step, the output of the heater 7 of the hot air circulation device 9 of 00W, A time of 10 minutes is specified, and the magnetron 6 is driven and controlled to output a microwave output of 250 W, and the hot air circulation device 9 is driven and controlled to output a heater output of 00 W. The control unit 14 then
Wait for the above time of 10 minutes to elapse in 10 steps.

At this time, the cooking temperature is maintained at about 98°C, and the starch is gelatinized.

When the above-mentioned time of 10 minutes has elapsed, the control unit 14 specifies a heater output of 1200 W, a temperature of 130° C., and a time of 5 minutes for the uneven process in step S11, and the heater output is increased to 1200 W.
The hot air circulation device 9 is driven and controlled by W so that the temperature detected by the thermistor 11 is maintained at 130° C., and in the next step 512, the above-mentioned time of 5 minutes is waited for. At this time,
The excess water will evaporate and the wateriness will disappear.

This completes the cooking of a small amount of rice of about 1 or 2 kamp, but in this rice cooking, the hot air circulation device 9 is allowed to be driven, and hot air heating is used in combination with microwave heating, and this combination has a large effect. However, the cooked rice will be in a very good condition.

Next, a case will be described in which a small amount of rice, approximately 1□'2 cups, is cooked with the bowl 15 covered with a resin film 17 as shown in FIGS. 2 and 3.

In this case, the control section 14 executes steps up to <53 as described above, but since it makes a green decision determination in step S3, it then executes steps 513 and thereafter.

That is, when the bowl 15 is covered with the resin film 7 as described above, the infrared temperature sensor 10 receives infrared rays from the resin film 17, but the heat capacity of this film is small and does not affect the infrared rays much. The temperature rise width (12-tl) detected by the temperature sensor 10 directly follows the temperature of the rice and water in the bowl 15, and is large as shown by the solid line in FIG. 6, reaching a predetermined width of 18° C. at the beginning of heating. As a result, in this case, the control section 14 makes an affirmative determination in step S3. At this time, it is automatically determined that the lid placed on the bowl 15 is the resin film 17.

Thus, the operations after step 513 are executed, but in this case, as will be understood from the following explanation, the control unit 14 prohibits the hot air circulation device 9 from being driven in the subsequent heating.

First, in step S13, the control unit 14 sets the microwave output to 90 W, the time to 8 minutes, and the temperature to 60° C. for the second water absorption step.
is specified, and the magnetron 6 is driven and controlled so that the temperature detected by the infrared temperature sensor 10 is maintained at 60° C. with this microwave output of 90 W, and in the next step 514, the above-mentioned time of 8 minutes has elapsed. . At this time, rice is 60-65
It is maintained at ℃ to promote water absorption of rice.

When this time period has elapsed, the control unit 14 specifies a microwave output of 500 W, a temperature of 103° C., and a voltage of 1 V for the boiling process in step S15.
The magnetron 6 is driven and controlled to output 00W.

The control unit 14 then performs the following steps in steps 516 and 517, respectively.
Wait for the temperature detected by the infrared temperature sensor 10 to reach the above temperature of 105°C, and also detect the temperature by the absolute humidity sensor 13; 3
Wait for the temperature (pressure) to rise by 1V from the value at the time of detection of the temperature t1.

When the above-mentioned temperature reaches 105°C or the above-mentioned IV increases, the control unit 14 specifies a microwave output of 140 to 15 minutes and a time rjJ of 15 minutes for the boiling sustaining process in step 518, and sets the microwave output to 140W. The magnetron 6 is driven and controlled in order to output the above.The control section 14 then performs S19.
Wait for the above 15 minutes to elapse in step. At this time, the cooking temperature is maintained at about 98°C, and the starch is gelatinized.

When the above-mentioned time of 15 minutes has elapsed, the control unit 14 specifies the micro liquid output cuff 0W and a time of 5 minutes for the smearing process in step S20, and drives and controls the magnetron 6 to release the micro liquid output cuff 0W. In the next step 521, it waits for the above-mentioned time of 5 minutes to elapse. At the second stage, the excess water evaporates and the wateriness disappears.

This completes the cooking of a small amount of rice (approximately F/2 cups), but in this rice cooking, the operation of the hot air circulation device 9 is prohibited and only microwave heating is performed, compared to when hot air heating is also used. However, the quality of the cooked rice is slightly inferior. However, since the hot air heating does not continue, melting of the resin film 17, which is used as a lid for the well 15, is suppressed.
A situation where the finished product of cooked rice deteriorates undesirably can be prevented. That is, when the greasy film 17 melts, water evaporates significantly, resulting in rice with a core.

It is now clear that in the above embodiment, step S3 corresponds to the first means of the present invention, steps S4 to S12 correspond to the third means of the present invention, and steps S3 to S521 correspond to the third means of the present invention. This corresponds to the second means of the invention.

In addition, to calculate the temperature rise width (t2-tl) when cooking rice with <1/2 cup of rice as in the above example and when separately cooking rice with 1 cup of rice, use becomes. However, in the case of cooking one cup of rice, a dielectric casserole with a large internal volume is used instead of the well 15.

(Effects of the Invention According to the present invention, when cooking rice in a container such as a bowl using L, it is possible to apply heater heating in addition to microwave heating, improving the quality of the rice cooking, and For example, when cooking rice with a lid covered with a resin film,
If the lid is melted, you can prevent the rice from becoming poorly cooked.

[Brief explanation of drawings]

The drawings relate to a microwave oven according to an embodiment of the present invention, and FIG. 1 is a front view, FIG. 2 is a front sectional view, FIG. 3 is a side sectional view, FIG. 4 is a circuit diagram, and FIG. 5 is a flowchart of a control program. , FIG. 6 is a temperature characteristic diagram during rice cooking. 5... Heating chamber, 6... Magnetron, 9... Hot air circulation device, 10... Infrared temperature sensor, 14... Control unit, 15... Bowl, 16... Common benefit, 17. ...Resin film.

Claims (1)

[Claims] (1) A heating chamber for storing food in a container with the lid closed; microwave heating means and heater heating means for heating the food; and an infrared temperature sensor that receives infrared rays from the lid; and a first means for determining whether the degree of temperature rise measured by the infrared temperature sensor at the beginning of heating has reached a predetermined value, and when the first means makes an affirmative determination. , a second means for prohibiting driving of the heater heating means during subsequent heating;
and third means for allowing the heater heating means to be driven in subsequent heating if the first means makes a negative determination.