JPS6324223B2 - - Google Patents

Description

Detailed Description of the Invention The present invention relates to non-contact temperature measurement of food in a microwave oven, and uses a material that changes color depending on the temperature, and measures the color change with a color sensor to determine the temperature of the food. The aim is to detect the In particular, it concerns the temperature control of sake sake.

Conventional food temperature measurement methods include contact temperature measurement, in which a contact sensor such as a meat probe 31 is inserted into the food to detect the temperature, as shown in Figure 1, and contact temperature measurement, in which a contact sensor such as the meat probe 31 is inserted into the food to detect the temperature, as shown in Figure 2. There are two types of temperature measurement methods: a non-contact temperature measurement method using an infrared sensor 32 that attempts to measure temperature by taking advantage of the fact that the amount of infrared radiation differs depending on the temperature. However, contact temperature measurement has hygiene issues such as the sensor becoming dirty, while temperature measurement using an infrared sensor depends on the temperature of the food surface, so the temperature of the food surface cannot be measured. Therefore, there was a problem in terms of the reliability of food temperature measurement. Especially when heating sake in a microwave oven, sake placed in a tall container such as Choshi is heated first from the top due to the nature of radio waves, so it is not possible to accurately measure the temperature of the sake by simply measuring the amount of infrared radiation from the sake. cannot be measured.
Accordingly, the present invention measures the temperature of a container heated by heat conduction from the sake to the container, and accurately controls the temperature of the sake sake bottle. At that time, the temperature change in the container is indicated by the color change of the temperature indicator of the temperature indicator attached to the container.The color is detected by a color sensor, converted into an electrical signal, and the color information is input to the electronic circuit, which controls the heating power. This is what we are trying to do. An example of the characteristics of the color sensor is shown in FIG. The color sensor element is a type of diode and has a characteristic of being sensitive to a certain wavelength. Therefore, by combining the wavelength of a color sensor and the change in color of a temperature indicator plate, it can be used as an efficient temperature sensor. In other words, when the temperature reaches a certain level (e.g. 50℃ to 60℃ for sake sake), the maximum sensitivity range of the color sensor is 6000Å to 7000Å.
By using a temperature indicator that suddenly changes color (corresponding to red to orange), the temperature of the container can be accurately detected. This utilizes the above principle. The configuration will be explained below based on the drawings.

In FIG. 4, microwaves generated by a magnetron 1 are guided into an oven 3 through a waveguide 2 and absorbed by the food inside the oven 3. The oven lamp 33 illuminates the inside of the oven 3.

In FIG. 5, a band-shaped temperature-indicating attachment 5 made of a material with spring properties and good thermal conductivity is wound around the body of the choshi 4. A temperature indicating material 6 is pasted on the surface of the container, and when the container warms up, the temperature of the temperature indicating material 6 rises due to conduction heat and changes color.

Since the inside of the heating chamber 3 is illuminated by a light source 33, a color change in the temperature indicating material 6 is detected by a color sensor 9. Alternatively, as shown in FIG. 6, light emitted from a color change detection light source 7 is collected by a lens 8 and illuminates the temperature indicating material 6. and color sensor 9
Since it outputs a current corresponding to the wavelength of the input light, a change in color of the temperature indicating material 6 is detected as a change in current.

In FIG. 7, the detection current of the color sensor 9 is amplified by the electronic circuit 10 and then transferred to the A/D converter 11.
is converted into a digital value by the microcomputer 12.
The microcomputer 12 determines the temperature of the container, that is, the sake. Then, by controlling the output from the relay output terminal 13, the primary side of the transformer 12a of the microwave oven circuit is turned on and off, and the transformer 1
The oscillation of the magnetron 1 connected to the secondary side of the magnetron 2a is controlled.

Fig. 8 shows the Choshi 4 in the center of the turntable 14.
and stop the rotation of the turntable 14,
The spot light from the color change detection light source 7 is displayed on the temperature display plate 6.
This is a diagram illustrating how the color sensor 9 detects the image.

FIG. 9 shows an example of a temperature-indicating attachment 16 having a temperature-indicating portion 15 containing a temperature-indicating material. It is used by attaching it to Choshi 4 as shown in Fig. 10. The color sensor 9 detects the temperature of the temperature indicator 15.

In addition, the condensing section of the light source 7 for photodetection changes the rotary resistor 17 shown in FIG.
The lens shaft 20 connected to the shaft of the pulse motor 19 rotates. The color sensor 9 also rotates in the same manner and operates so that the spot light is concentrated on the temperature indicating material 6 even if the mounting height of the temperature indicating attachment 5 changes.

By shining a dedicated light for photometry from the condensing part of the light detection light source 7 to the temperature indicator 15, color changes can be detected more accurately and more accurately than when using external light or an internal light. Color changes can be detected with high sensitivity. Also, during color change detection operation, the microcomputer 12
When the signal from terminal 23 is turned OFF, relay contact 2 is connected in series with turntable motor 21.
2 is opened and the turntable 14 stops.

Since the temperature of the container is detected by the temperature-indicating attachment in this way, the following advantages are provided. In other words, lukewarm sake (40℃~50℃),
When you want to obtain a predetermined temperature such as for normal sake (50°C to 55°C) or hot sake (55°C to 60°C), attach the temperature indicator attachment 5 to the top of the container for lukewarm sake, and slightly below it for regular sake. If it is attached at the bottom when hot sake is being served, the temperature of the sake will be different when the temperature indicator changes color due to the above-mentioned characteristics of microwave heating, and a predetermined temperature can be obtained. In addition, the temperature change of the temperature-indicating material is accurate to about ±1℃,
Since the color changes from red to orange, for example, when combined with a color sensor, the sensor detection level changes rapidly. Therefore, temperature changes can be detected reliably. Also, since the temperature indicator is removable, you can use a conventional container. This method has many advantages over conventional alcoholic beverage detection.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing an example of temperature measurement using a contact type, Fig. 2 is a sectional view showing an example of temperature measurement using an infrared sensor, and Fig. 3 is a diagram showing characteristics of a color sensor.
Fig. 4 is a partially cutaway front view of the microwave oven, Fig. 5 is a temperature indicator attachment and installation diagram, Fig. 6 is a principle diagram of color change detection, Fig. 7 is a diagram showing an example of an electronic circuit, Figure 8 is a principle diagram of color change detection in the heating chamber, Figure 9 is a perspective view showing another example of the temperature indicating attachment, Figure 10 is a perspective view showing the installation state of the temperature indicating attachment, and Figure 11 is a color change detection diagram. FIG. 12, which is a diagram showing the movement of the detection device, is a perspective view showing the state in which the temperature indicating attachment is attached. 3...Heating chamber, 2...Waveguide, 1...Magnetron, 7...Light source for photodetection, 8...Condenser lens,
9... Color sensor, 5... Temperature indicating attachment, 6... Temperature indicating material, 14... Turntable, 2
2... Relay contact, 19... Step motor, 1
6...Temperature attachment, 33...Light source.

Claims (1)

[Scope of Claims] 1. A heating chamber in which food is placed, a high-frequency generator that excites high-frequency power to heat the food, and a light source that illuminates the inside of the heating chamber, and detects the color inside the heating chamber. A temperature-indicating attachment having a color sensor, which is detachably attached to the container inside the heating chamber, and has a temperature-indicating part on its surface that changes color depending on the temperature to the highest sensitivity band of the color sensor; A microwave oven with a temperature detector, which has a light section and a light source for detecting a color change of the temperature indicating material. 2. The microwave oven with a temperature sensor according to claim 1, wherein the temperature indicating portion on the surface of the temperature indicating attachment is constructed by pasting a sheet containing a temperature indicating material. 3. Claim 1 in which the temperature indicating portion on the surface of the temperature indicating attachment is constructed by applying a temperature indicating material
A microwave oven with a temperature sensor as described in section. 4. The microwave oven with a temperature sensor according to claim 1, wherein the temperature indicating part of the temperature indicating attachment is made of a material containing a temperature indicating material in a material with low dielectric loss. 5. The microwave oven with a temperature sensor according to claim 1, wherein the mounting angle of the light condensing part and the mounting angle of the color sensor are variable.