JPS6333050Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a cooking device such as a microwave oven, and more specifically, to an improvement in a cooking device configured to detect the surface temperature of food and control heating.

2. Description of the Related Art Cooking devices such as microwave ovens are known that are configured to capture infrared rays emitted by food to be cooked, detect the surface temperature of the food using this, and control heating means such as a magnetron based on this. In such cookers, after it is detected that the finishing temperature determined according to the menu has been reached, the previous temperature is changed to equalize the temperature to eliminate the difference between the surface temperature and internal temperature, which is control information. Post-heating was performed at a lower output than the cooking temperature.

However, in the past, this post-heating was carried out regardless of the amount of food, so depending on the amount, there were cases where the food was undercooked or overcooked.

The present invention has been made to eliminate such inconveniences, and the object is to provide a cooking device that can perform post-heating according to the amount of cooked food to obtain a uniform finished state. shall be.

The cooking device according to the present invention is configured to detect the surface temperature of food, perform heating control based on the detected temperature to perform cooking, and then perform post-heating for temperature equalization. As shown in the figure, a means A for measuring the time required for the cooking, a means B for determining whether the time measurement result is longer or shorter than a predetermined value;
means C for determining the heating output during post-heating to be the first output when the determining means determines that the length is long;
It is characterized by comprising means D for determining the heating output during post-heating to a second output smaller than the first output when the determination means determines that the heating output is short.

The present invention will be explained in detail below based on the drawings showing an embodiment in a microwave oven.

FIG. 1 is a schematic front sectional view of a microwave oven according to the present invention. Turntable 1 in the cooking chamber 14
5 is connected to a motor 16 provided below and rotated slowly, so that the food 17 on the turntable 15 is evenly irradiated with microwaves. Microwaves emitted by a magnetron 18 placed on the right side of the cooking chamber 14 enter the cooking chamber 14 through a waveguide 19, and a stirrer fan 19b is rotated by a motor 19a installed in the space above the top plate. The food 17 is heated. Further, in the upper space of the cooking chamber 14, a part of a temperature measuring device 20 that measures the surface temperature of the food 17 in a non-contact manner is provided. That is, a window 13 is provided above the turntable 15, through which infrared rays emitted by the food 17 are taken in. And this window 1
A pyroelectric infrared sensor 23 is installed above 3, and its output is sent to the required temperature detection circuit 21.
It is configured to be input to . The infrared rays emitted from the food 17 reach the sensor 23 through the window 13,
A disc 28a of a chipper 28 (having cutouts at predetermined locations) is interposed between the two, and is rotated to intermittently cause infrared rays to reach the sensor 23, Food temperature disc 28
It is intended to obtain a waveform signal having an amplitude corresponding to the difference from the surface temperature a (separate measuring means is provided).

FIG. 2 is a block diagram schematically showing the configuration of the electronic circuit of the cooker of the present invention, including the CPU, ROM,
A microcomputer 10 consisting of RAM and the like functions as a control center of this cooker. On the right side of the front of this cooker, there are provided an input key 11 for menu selection, etc., and a display section 12 for displaying the input value from this key 11 and the remaining time of the timer during timer operation. Signals are exchanged between the keys 11 and the display section 12 and the microcomputer 10.

The microcomputer 10 also reads an output signal from the temperature detection circuit 21 of the temperature measuring device 20, that is, a signal representing the temperature of the food 17. It also issues a signal to the oscillation control circuit 18a of the magnetron 18 to control its output.

Next, the main part of the control contents of the cooking appliance of the present invention by the microcomputer 10 will be explained based on the flowchart shown in FIG.

When the input key 11 is used to select and command the cooking of the menu corresponding to the food 17, the microcomputer 10 resets the internal time counter, also resets the second flag and the time flag, and then displays the menu corresponding to the selected menu on the display section 12. The corresponding data is stored in the display memory in order to display the number to be displayed.
Next, the heating output P ₀ determined according to this menu and the finishing temperature (surface temperature) Ts at which cooking should be completed at this heating output P ₀ are set in a predetermined register.

Then, a predetermined signal is sent to the oscillation control circuit 18a to start the oscillation of the magnetron 18, and the output is
Oscillation control is performed to set P to ₀ .

The time flag is a temperature operation in which the magnetron 18 is oscillated at a heating output P ₀ until the surface temperature of the food 17 being measured reaches Ts, and an output P ₁ to be described later.
Or, it is for distinguishing from the time operation for post-heating in which the magnetron 18 is oscillated for a predetermined time t at _P2 , and the latter is set (=1).
The former corresponds to reset (=0).

Immediately after the start of heating, the time flag is reset, and once this is determined, the contents of the second flag are then checked. This second flag is set every second by a timekeeping routine. If it has not been set, it is reset in the next step and the routine moves to a routine for displaying the contents of the display memory, as well as the above-mentioned timekeeping routine, key sense routine, etc. On the other hand, if the second flag is set, the content ti of the time counter is incremented by one. Also read the food temperature TF. Then, compare the finishing temperature Ts and food temperature TF, and if TF<Ts, food 1
7 Assuming that the surface has not reached the finishing temperature Ts, the process moves to the second flag reset step described above.

As cooking progresses, the food temperature TF eventually becomes higher than the finishing temperature Ts.

In such a situation, the time from the start of heating to the time when TF≧Ts, that is, the time K・ts that serves as the reference for comparison with the content ti of the timing counter.
(ts is a fixed time value, K is a constant determined by the menu)
Compare the magnitude with , and if ti≧K・ts, select the heating output to be changed to P ₁ , and if ti<K・ts, select the heating output to P ₂ (P ₁ > P ₂ ). Set and store in a predetermined register. In other words, if ti≧K・ts, it is assumed that the rise in surface temperature has been delayed due to a large amount of food 17, etc., and the heating output is set to a relatively large _P1 , and if ti<K・ts, the Conversely, post-heating is performed by setting the heating output to a relatively small value _P2 .

Then, the post-heating time is a pre-given time t
This is stored in the display memory in order to be displayed on the display unit 12. Then, since the above-mentioned time operation will be started, the time flag is set, and then the second flag is reset.

Next, in the step to check the contents of the time flag, this is set, so check the seconds flag,
Post-heating is performed at output P ₁ or P ₂ while decrementing the contents of the display memory once per second.
Then, when the contents of the display memory become 0, the oscillation of the magnetron 18 is stopped.

Through the above control, the food is first cooked at the output P ₀ (P ₀ > P ₁ > P ₂ ) until the surface reaches the finishing temperature Ts, and once the temperature reaches Ts, the length of the heating time required up to that point is reduced. In other words, the output is switched to P ₁ or P ₂ depending on the amount of food, and heating is performed after time t. In other words, the output of the heating means during post-heating is set to be larger as the amount of food is larger, and smaller as the amount of food is smaller. As a result, undercooking and overcooking are eliminated, and variations in the finished cooking are eliminated.

In the above embodiment, the output during post-heating is P ₁ ,
Although it was decided to divide the process into two stages _P2 , it goes without saying that it is possible to improve the control accuracy of post-heating by using more stages.

As described above, the cooking device according to the present invention is equipped with a means for measuring the time required for cooking and a means for determining the heating output during post-heating based on the time measurement result, so that the cooking finish can be improved. A uniform cooking device can be achieved. When the amount of food to be cooked is small, the output is suppressed, so that the temperature of the food does not rise excessively due to post-heating, causing moisture evaporation and spoiling the flavor. It goes without saying that the present invention can also be applied to cooking appliances other than microwave ovens.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention; Fig. 1 is a schematic front cross-sectional view of a microwave oven according to the invention, Fig. 2 is a schematic block diagram of its electronic circuit, and Fig. 3 shows the control contents of the microcomputer. The flowchart shown in FIG. 4 is a functional block diagram of the main parts of the cooking device of the present invention. 10...Microcomputer, 11...Input key, 12...Display section, 18...Magnetron,
20...Temperature measuring device.

Claims (1)

[Scope of utility model registration request] After detecting the surface temperature of the food and performing cooking by controlling heating based on the detected temperature, the time required for the cooking is measured in a cooking device configured to perform post-heating for uniform temperature. means for determining whether the time measurement result is longer or shorter than a predetermined value;
means for determining the heating output during post-heating to be a first output when the determining means determines that the heating output is long; and means for determining the heating output during post-heating from the first output when the determining means determines that the heating output is short; A cooking appliance characterized by comprising: means for determining a second small output.