JP4811099B2 - Cooker - Google Patents

Description

  The present invention relates to a heating cooker having, as a heat source, an induction heating cooker or a halogen heater used in general homes, offices, restaurants, and the like.

Conventionally, a thermistor has often been used in this type of cooking device in order to detect the temperature of a heated object such as a pan. However, the thermistor is provided on the lower surface of the top plate and detects the temperature of the object to be heated by heat conduction through the top plate, so the time detection response is slow. In recent years, various methods for detecting the temperature of an object to be heated using an infrared sensor have been disclosed (for example, see Patent Document 1).
JP 2004-111055 A

  However, in the temperature detection method using the infrared sensor, when the object to be heated is not on the upper surface of the sensor (for example, when the object to be heated is not placed at a normal position but placed at a deviation), the temperature of the object to be heated is adjusted. There was a problem that it could not be detected. When the temperature of the object to be heated cannot be detected, the heating cannot be controlled. For example, the object to be heated becomes extremely hot. Therefore, an illuminance sensor capable of detecting visible light is provided in the vicinity of the infrared sensor to detect visible light such as kitchen lighting or sunlight irradiated on the upper surface of the top plate. When the object to be heated is not on the upper surface of the sensor (visible light is incident) The detection output of) is larger than the detection output when the object to be heated is on the upper surface of the sensor (visible light is blocked by the object to be heated and does not enter), and the presence / absence of the object to be heated on the sensor is determined. However, there is a problem that the number of parts increases and the cost increases due to the provision of the illuminance sensor.

  The present invention solves the above-described conventional problems, and realizes a safe heating cooker that can determine whether an object to be heated is on the upper surface of the sensor without newly providing another component such as an illuminance sensor. It is intended.

  In order to solve the above-described conventional problems, the cooking device of the present invention uses a single infrared sensor, focusing on the fact that a visible light region can be partially detected even by an infrared sensor and that the visible light partially includes infrared light. Therefore, it is possible to determine whether or not the object to be heated is on the upper surface of the sensor without providing new parts.

  The cooking device of the present invention can determine whether or not an object to be heated is placed on the upper surface of the infrared sensor with a small number of parts.

  1st invention is provided in the to-be-heated object, the top plate which mounts the said to-be-heated object, the said top plate lower surface, and is radiated | emitted to the infrared rays radiated | emitted from the bottom face of the said to-be-heated object, and the top plate upper surface. A detection element that detects visible light that is present, and when the detection element detects an output of a predetermined value or more immediately before heating, there is no object to be heated on the upper surface of the detection element or the object to be heated is By determining that the temperature is high and maintaining the heating stop or suppressing the heating power after the start of heating, the upper surface of the sensing element is heated without providing another component such as an illuminance sensor. The presence or absence of an object can be performed, and a safe cooking device can be realized.

  In the second invention, in particular, visible light (generally having a wavelength of 0.38 to 0.78 μm) can be obtained by making the sensing element an element having a spectral sensitivity peak at a wavelength of approximately 0.7 to 1 μm in the first invention. Since both infrared rays (0.78 to 1000 μm) can be easily detected, the presence or absence of an object to be heated on the upper surface of the detection element can be performed more accurately, and a safe cooking device can be realized.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 is a cross-sectional view of the induction heating cooker of the present embodiment.

  In FIG. 1, an induction heating coil 2 is connected to an inverter 1, and an object to be heated 3 is a cooking pot in the present embodiment. The object to be heated 3 is placed on the top plate 4, and the detection element 5 detects the temperature of the object to be heated 3, and specifically, a silicon PIN photodiode is used. This element is extremely inexpensive because it is made of silicon and widely used in TV remote controls and the like. The spectral sensitivity characteristics of the element are shown in FIG. As shown in the figure, in the case of the sensing element 5 of the present embodiment, the sensitivity peak is set to about 1 μm, and light having a wavelength of about 0.8 to 1.2 μm can be detected. FIG. 3 shows the wavelength-radiant energy characteristics of a 300 ° C. black body. As shown in the figure, energy can be detected at 1.0 μm or more, and detection is possible as long as the sensitivity characteristic of the detection element 5 of the present embodiment. FIG. 4 shows an example of the radiant energy distribution of sunlight. As shown in the figure, detection is possible at a wavelength of 0.7 μm or more. In the case of an incandescent light bulb used in general household lighting, the energy on the infrared side is further increased, so that it can be detected more easily.

  Further, even in the case of a fluorescent lamp, there is a considerable amount of energy of 0.7 μm or more, and sufficient detection is possible according to experiments conducted by the inventors. As described above, when the detection element 5 of the present embodiment is used, it is possible to detect infrared energy from the object to be heated 3 and visible light incident when the object to be heated 3 is not on the upper surface of the detection element 5 with one element.

  In the case of the present embodiment, there is an influence on the detection element 5 due to the rise in the pan temperature during heating, and the user moves the object to be heated 3 from the temperature detection element 5 or immediately before the heating. 5, the output of the detection element 5 is detected immediately before the start of heating, and if the output is equal to or less than a predetermined value, it is determined that the article to be heated 3 is placed, and heating is started. . If the output is equal to or greater than a predetermined value, it is determined that the object to be heated 3 is not on the upper surface of the detection element 5, heating is stopped, and an error is displayed.

  In the case of the present embodiment, the detection element 5 is placed at the center of the heating coil 2. However, for example, the heating coil 2 may be divided into an inner periphery and an outer periphery and provided between them. In this case, it is possible to detect a higher temperature of the object 3 to be heated by induction heating compared to the detection by the center portion, and it is possible to detect that the object 3 to be heated becomes an abnormally high temperature earlier. When the detection element 5 is shifted from the center in this way, the possibility that the user will accidentally shift the object to be heated 3 (so as not to be placed on the upper surface of the detection element 5) is increased. Since it can detect, it becomes a safer cooking device.

  The cooking device according to the present invention can determine whether or not the object to be heated is placed on the upper surface of the infrared sensor with a small number of parts, so that the object to be heated used in a general home, office, restaurant, etc. It can also be applied to uses such as a heating cooker.

Sectional drawing of the heating cooker in the 1st Embodiment of this invention The figure which shows the sensitivity characteristic of the detection element 5 similarly Figure showing radiant energy distribution of black body Figure showing the radiant energy distribution of sunlight

Explanation of symbols

3 Heated object 4 Top plate 5 Sensor element

Claims (2)

An object to be heated, a top plate on which the object to be heated is placed, and an infrared ray radiated from the bottom surface of the object to be heated and a visible light ray radiated from the top surface of the top plate are detected. And when the detection element detects an output of a predetermined value or more immediately before heating, it is determined that the object to be heated is not present on the upper surface of the detection element or the object to be heated is at a high temperature. And the heating cooker which hold | suppresses a heating stop or suppresses the heating power after a heating start. The cooking device according to claim 1, wherein the detection element has a peak of spectral sensitivity at a wavelength of about 0.7 to 1 μm.