JPS6319996B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a high frequency heating device that detects the temperature of a food to be cooked using an infrared detector.

Recently, infrared detectors (hereinafter referred to as
It is simply called a detector. ), the infrared rays emitted from the food to be cooked are detected, the temperature of the food is detected from the amount of infrared radiation, and the high frequency output is controlled.

FIG. 1 shows a conventional example. Here, 1 is a heating chamber in which the food to be cooked 2 is stored, 3 is a magnetron, and 4
6 is an opening formed in the ceiling plate, and 6 is its light receiving surface 6a.
is a detector provided facing the opening 4; 7 is a blade-shaped chopper; 8 is a motor for rotating the chopper; 9 is a control circuit interposed between the magnetron 3 and a power source 10 by the output of the detector 6; Contact 11
The high frequency output is controlled by turning on and off.

However, in the high-frequency heating device configured in this way, when the food to be cooked 2 is heated, the steam, smoke, etc. generated from this rises to the vicinity of the ceiling plate 5 as shown by the dotted line in FIG. 4 and adheres to the light-receiving surface 6a of the detector 6, and the dirt becomes worse as the number of times it is used increases. Therefore, the infrared rays emitted from the food to be cooked 2 are transmitted to the light receiving surface 6a.
There is a drawback that the amount of infrared rays absorbed by water droplets and smoke stains adhering to the object 2 and emitted from the object 2, that is, the temperature of the object 2 cannot be accurately detected.

Therefore, in order to eliminate this drawback, the ceiling plate 5
A gap is provided between the opening 4 and the detector 6 to blow air into the heating chamber 1 from the opening 4 to prevent water vapor and smoke from rising through the opening 4 and adhering to the light receiving surface 6a. A device was also devised to prevent dirt by blowing air directly onto the surface. However, such a device not only cannot completely prevent the light-receiving surface 6a from becoming dirty, but also has new drawbacks such as a complicated structure.

The present invention has been made in consideration of the above-mentioned drawbacks, and its purpose is to provide an infrared source that emits a standard correction infrared ray, and to calculate the amount of infrared rays detected from the food to be cooked using this infrared source. That is, the object of the present invention is to provide a high-frequency heating device that can accurately detect the temperature of the object to be cooked by correcting the temperature of the object.

Hereinafter, the structure of one embodiment of the present invention will be explained using the drawings. FIG. 2 is a schematic configuration diagram of the high-frequency heating device according to the present invention.
A tray 22 is provided on which the heating chamber 2 is placed.
A magnetron 23 is fixed to the upper part of the side wall of 0 as a high frequency oscillation part. Also, a heat sink 2 is provided on the outside of the ceiling plate 24 of the heating chamber 20, and is placed close to and opposite to the ceiling plate 24.
6 to form a space 25. A drive motor 27 is fixed approximately at the center of the heat sink 26 so that the rotating shaft 28 is located in this space 25. At the tip of this rotating shaft 28, a wing-shaped chopper 29 having a partial notch is attached approximately parallel to the ceiling plate 24.

Next, an opening 31 is formed in the ceiling plate 24 within a radius smaller than the radius of the chopper 29. Then, the detector 30 is fixed to the heat sink 26 via the chopper 29 so that the light receiving surface 30a thereof is located opposite the opening 31. This detector 30 detects infrared rays emitted from the object to be cooked 21 and generates a first temperature signal corresponding to the detected amount. This signal 32 is a correction signal 33 which will be described later.
is added and corrected by the adder 34, and converted into a second temperature signal 35. Based on the second temperature signal 35, the control section 36 turns on and off a contact 38 interposed between the magnetron 23 and the power source A37 to control the high frequency output.

Next, the infrared source 39 and the correction section 40 will be explained. The infrared rays emitted from this infrared source 39 serve as a reference for determining the correction signal 33, and an amount of infrared rays corresponding to, for example, 100° C. is emitted. And this infrared source 39
is attached to the ceiling plate 24 by a support member 41 provided next to the heat sink 26, and as shown by the arrow in the figure, the infrared rays emitted from it are reflected by the reflector 42 provided on the ceiling plate 24, and the heat sink 26 The sensor is positioned and attached so that it can be detected by the detector 30 through the passage hole 43 formed in the side of the sensor.

This detector 30 also has a contact point C52, which will be described later.
The correction section 40 is connected to the addition section 34 via the correction section 40 . By connecting in this manner, the correction unit 40 compares the detection signal corresponding to the amount of infrared rays emitted from the infrared source 39 with a reference signal stored in the internal memory corresponding to, for example, 100°C, and performs correction based on the comparison result. Determine signal 33.
This internally stored reference signal is set at a level corresponding to the infrared rays actually generated from the infrared ray source 39.

In detail, when the sensor surface is clean, the detection signal based on the amount of radiation from the infrared source and the memorized reference signal are at the same level, but when the sensor surface is dirty, the sensitivity of the sensor decreases. Therefore, the detection signal level from the infrared source 39 ends up being lower than the internally stored reference signal level.

Therefore, a level difference ΔD between the detection signal level from the infrared source 39 and the reference signal is detected, this difference ΔD is used as a correction signal 33, and this value is stored and sent to the addition section 34. Then, this signal is added to the adder 3
4, it is added to the first temperature signal 32 and corrected, and a second temperature signal 35 is output. In short, the reference infrared source 39 is provided to detect ΔD, which is the degree of dirt on the sensor surface, and the temperature signal is corrected by an amount corresponding to this ΔD.

Further, the correction section 40 erases the correction signal 33 stored during the previous cooking at the same time as the cooking switch (not shown) is turned on, and newly determines the correction signal 33 based on the amount of infrared rays emitted from the infrared source 39. memorize it. When this correction signal 33 is determined, the infrared source 39 stops emitting its infrared rays, and the magnetron 23 is configured to oscillate.

That is, a contact B50 that is turned on when the cooking switch is turned on is interposed between the power source B51 and the infrared source 39, and a contact C52 that is turned on at the same time as the contact B50 is also provided between the correction section 40 and the detector 30.
intervene. These contacts B50 and C52 are turned off when the control unit 36 detects that the correction signal 33 has been determined, and the contacts A3
8 is controlled by this control unit 36 to turn on.

Next, the operation of the high frequency heating device configured as described above will be explained. First, when you turn on the cooking switch, contact B50 turns on and power source B5
1, the infrared source 39 emits infrared rays. This infrared source 39 is as described above.
It emits an amount of infrared rays equivalent to 100 degrees Celsius, and the infrared rays emitted from this are detected through the reflecting mirror 42 and further through the light-receiving surface 30a, which has accumulated dirt from water vapor generated from the food 21 during cooking. detected by the device 30. Also, this contact B50
When C52 turns on, contact C52 also turns on, so
The signal detected by the detector 30 is sent to a correction section 40, where it is compared with a signal corresponding to 100° C. stored inside this correction section 40, and a correction signal 33 is determined. Thereafter, the correction signal 33 determined here is sent to the control section 36 via the addition section 34, and the control section 36 turns off contact B50 and contact C52 by detecting this correction signal 33, and turns off contact A38. turn on. As a result, infrared source 3
9 stops the emission of infrared rays, and the magnetron 2
3 starts oscillation.

Due to the oscillation of this magnetron 23, the heating chamber 2
The to-be-cooked object 21 housed in the container 0 is heated and emits infrared rays. The detector 30 detects this infrared ray through the light-receiving surface 30a on which dirt has accumulated, converts it into a first temperature signal 32, and sends it to the addition section 34. The adder 34 adds the first temperature signal 32 and the correction signal 33 and outputs the second temperature signal 35 to the controller 3.
Send to 6. In response to this second temperature signal 35, the control section 36 turns on and off the contact A38 to control the output of the magnetron 23.

As described above, according to this embodiment, water vapor, smoke, etc. generated from the food to be cooked 21 are detected by the detector 30.
By soiling the light-receiving surface 30a, infrared rays are absorbed by the soiled light-receiving surface 30a, thereby eliminating the drawback that the temperature signal for operating the control section 36 cannot be accurately detected. That is, the infrared rays emitted from the food to be cooked 21 are absorbed by the dirt on the light-receiving surface 30a, but the infrared rays emitted from the infrared rays source 39 are absorbed by the dirt on the light-receiving surface 30a.
The infrared rays emitted from the
is determined, the second temperature signal 35 output using this correction signal 33 accurately corresponds to the food to be cooked 2.
This is because it represents the temperature of 1.

Next, FIG. 3 shows another embodiment, in which an opening 6 having a rising piece 61 around the ceiling plate 60 is shown.
2 will be provided. A holder 63 is detachably attached to this opening 62 as an infrared source, as shown by the arrow in the figure. This holder 63 is, for example,
It emits an amount of infrared radiation equivalent to 100℃.
Then, before starting high-frequency cooking, the holder 63 is inserted into the opening 62, the amount of infrared rays is detected by the detector 30, and the correction signal 33 is determined by the correction section 40. After determining this correction signal 33 and before starting cooking, the holder 63 is removed before starting cooking.

According to this embodiment, the infrared rays emitted from the reference infrared source will not be absorbed and changed due to dirt on the surface of the reflecting mirror 42, and therefore no error will occur in the correction signal 33 itself. , the temperature of the food to be cooked can be detected more accurately.

As described above, according to the present invention, an infrared source that emits infrared rays for correction as a reference is provided, and the temperature of the food to be cooked is corrected using this infrared source, so that the temperature of the food to be cooked is accurately detected. It is possible to provide a high-frequency heating device that can.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram showing a conventional high-frequency heating device, FIG. 2 is a schematic configuration diagram showing one embodiment of the present invention, and FIG. 3 is a schematic configuration diagram of main parts showing another embodiment. 20... Heating chamber, 21... Food to be cooked, 23...
High frequency oscillator (magnetron), 30... Infrared detector, 32... First temperature signal, 33... Correction signal, 34... Adder, 35... Second temperature signal, 36... Control unit, 39,63...Infrared source,
40...Correction section.

Claims (1)

[Claims] 1. A heating chamber that stores a food to be cooked; an infrared detector that detects infrared rays emitted from the food and generates a first temperature signal corresponding to the detected amount;
An infrared source that emits infrared rays for correction serves as a standard, and the detected amount of infrared rays emitted from this infrared source is detected by the infrared detector, and this detected amount is compared with a reference signal stored in internal memory, and correction is made in accordance with the comparison result. a correction section that generates a signal; and a correction section that generates a signal;
A high-frequency heating device comprising: an adder that generates a second temperature signal by adding and correcting temperature signals; and a controller that controls an output of a high-frequency oscillator based on the second temperature signal.