JP2005106388A - Microwave oven - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a microwave oven capable of heating food in the optimum way. <P>SOLUTION: A control circuit of this microwave oven executes a step S702 of starting undulatory radiation to a cooking chamber, a step S704 of receiving signals from reflection waves, a step S706 of detecting distance to subject matter, a step S708 to determine the mode of disposition of a cooking plate based on the detected distance, and a step S712 of executing heating control in accordance with the position of the cooking plate in a case where the cooking plate is disposed in the cooking chamber (S710: YES). <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a microwave oven, and more particularly to a microwave oven capable of selecting a heat treatment based on a distance to food.

  The microwave oven has a plurality of heating courses as its function, and the user can optimally heat the food by selecting an appropriate heating course. However, depending on the food to be heated, there is a problem that such selection is not easy and operation for selecting a heating course is difficult. In addition, even when a heating course is selected, there is a problem that heating control cannot be appropriately performed based on the state of the type, amount, or shape of the food.

  Therefore, for example, Japanese Patent Laid-Open No. 7-27338 (Patent Document 1) discloses a heating apparatus that can measure a distance to a cooking utensil with a distance sensor and select a course such as an oven or a grill. This heating device is based on a heating unit, a detection unit that detects the distance from the upper surface of the heating chamber to a container that is installed in the heating chamber corresponding to the cooking mode, and a tool that includes a dish, and an output signal of the detection unit. And a control unit for controlling the heating unit.

  According to this heating device, the cooking mode is identified when the distance between the installation position of the utensil such as a dedicated container or a cooking plate used in accordance with the cooking mode and the upper surface of the heating chamber is measured. Since the control unit controls the heating unit based on the identification result, cooking can be automated. Thus, by identifying the cooking mode as the selection of the heating course, the user can easily cook using the microwave oven.

  Further, for example, Japanese Patent Application Laid-Open No. 7-77332 (Patent Document 2) discloses a heating device that can discriminate a heated object. The heating device includes a detection unit that detects a distance from the upper surface of the heating chamber to an object to be heated, a recognition unit that recognizes a change in distance based on an output signal from the detection unit, and an output signal from the recognition unit. And a control unit for controlling the heating unit based on the control unit.

According to this heating device, the bulge of the wrap of the food covered with the wrap or the bulge of the cake is detected from the temporal change in the distance information from the upper surface of the heating chamber to the object to be heated. Since a control part controls a heating part based on information detected in this way, it can improve the quality of cooking of a heated part.
JP-A-7-27338 Japanese Patent Laid-Open No. 7-77332

  However, according to the heating device disclosed in Patent Document 1, even if the cooking mode can be identified for one specific type of cooking dish, each dish is determined for a plurality of dishes, or the cooking dish is The case where it is directly placed on the bottom of the cooking chamber cannot be identified. Therefore, the heating course may not be selected properly.

  Moreover, according to the heating apparatus disclosed in Patent Document 2, even though the heat treatment can be controlled based on the change during heating of the object to be heated, what kind of object to be heated is heated before heating. I can't judge. Therefore, the heating of the object to be heated may not be properly controlled.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a microwave oven in which the ability to discriminate the type and installation position of a cooking dish is improved.

  Another object of the present invention is to provide a microwave oven that can automatically determine the type of food and the course to be heated.

  According to one aspect of the present invention, a microwave oven includes a heating chamber that houses food, a cooking dish that is disposed in the heating chamber and has a surface state different from the surface state of the bottom surface of the heating chamber, and heating for heating the food The means, the output means for radiating the wave in the heating chamber, receiving the reflected wave and outputting the reception result, and the reception range of the wave reflection acquired in advance are stored in association with the cooking dish. For controlling the heating means so as to heat the food based on the installation state of the cooking dish and the determination means for determining the installation state of the cooking dish based on the storage means for receiving, the reception result and the reception range Control means.

  According to the microwave oven having such a configuration, when the output unit radiates a wave to the heating chamber and receives a reflected wave of the wave, a reception result is output. The output means includes, for example, an infrared sensor, an ultrasonic sensor and the like. The reception result includes a wave phase, a voltage value, a detection distance, and the like. Here, the detection distance is not an actual distance but a distance calculated based on a reflected wave received by the output means. The storage means stores a reception range of the reflected wave of the wave (for example, a range in consideration of variations such as a detection error, a design error, and a cooking plate state) in association with the cooking plate. The discriminating unit discriminates the installation state of the cooking dish in the heating chamber based on the reception result and the reception range. That is, since the wave reflection state is affected by the surface state of the reflector (for example, surface roughness, shape, inclination, coating, etc.), the installation state of the cooking dish can be determined based on the reflected wave. . This installed state includes whether or not the cooking dish is arranged in the heating chamber, or the type of cooking dish arranged. A control means controls a heating means (for example, magnetron) so that food may be heated based on the installation state. If it does in this way, the user of a microwave oven can perform an optimal heat processing to a microwave oven, without setting the position of the cooking pan arrange | positioned in a heating chamber. Alternatively, when the installation position and type of the cooking dish and the cooking menu are stored in association with each other, the cooking menu can be automatically determined from the installation state of the cooking dish. Thereby, the microwave oven which can improve a user's convenience can be provided.

  Preferably, a memory | storage means memorize | stores the range of the distance detected corresponding to the cooking dish acquired previously. The output means outputs the detection distance detected based on the reception state of the reflected wave of the wave. The discrimination means includes an installation state discrimination means for discriminating the installation state of the cooking dish based on the stored distance range and the detected distance.

  According to the microwave oven having such a configuration, the optimum heat treatment can be executed by detecting the distance to the cooking dish and determining the installation state of the cooking dish.

  Preferably, the storage unit stores a range of distance acquired in advance as an output of the output unit when the cooking pan is not disposed in the heating chamber. The installation state determination means includes presence / absence determination means for determining whether or not the cooking pan is placed in the heating chamber based on the stored distance range and the detected distance.

  According to the microwave oven having such a configuration, the presence / absence discriminating means determines whether or not the cooking pan is arranged in the heating chamber based on the detected distance and the range of distances acquired and stored in advance. Is determined. Therefore, by storing the distance range in the storage means in advance, it can be accurately determined that the cooking pan is not arranged in the heating chamber.

  Preferably, the presence / absence determining means determines that the cooking pan is not disposed in the heating chamber when the detection distance is included in the distance range. When the detection distance is not included in the distance range, the presence / absence determining means determines that the cooking dish is disposed in the heating chamber.

  According to the microwave oven having such a configuration, when the detected distance is not included in the range of the distance stored in advance, it is determined that the cooking dish is disposed in the heating chamber. Therefore, the heat treatment can be executed only in such a case, and the heat treatment when the cooking pan is not arranged in the heating chamber can be executed. Alternatively, it is possible to automatically select the heating control when the cooking pan is arranged in the heating chamber and the heating control when it is not arranged. In this way, malfunction of the microwave oven can be prevented.

  Preferably, the heating chamber is formed with a plurality of arrangement portions on which cooking dishes are arranged. A memory | storage means memorize | stores the range of each distance detected when a cooking plate is arrange | positioned at each arrangement | positioning part. The installation state determination unit includes a position determination unit for determining in which arrangement unit the cooking dish is arranged based on the detected distance and the range of the stored distance.

  According to the microwave oven having such a configuration, in addition to the determination as to whether or not the cooking dish is arranged in the heating chamber, in which of the plurality of arrangement parts the cooking dish is arranged It is determined whether or not. Therefore, since the heat treatment by the microwave oven can be changed according to the arrangement portion, more appropriate heat treatment can be performed.

  Preferably, when the detected distance is included in the range of the distance, the position determining unit determines that the cooking dish is arranged in the arrangement unit corresponding to the range of the distance.

  According to the microwave oven having such a configuration, when the data of the distance to each placement unit detected by the output unit is stored in the storage unit in advance, the position determination unit is configured by the placement unit in which the cooking dish is placed. Is determined. If it does in this way, even if it forms several arrangement | positioning parts in a heating chamber, since each arrangement | positioning part can be specified easily, the precision of heat processing can be improved.

  Preferably, the surface state is any one of a material, a finished state of the surface treatment, a shape, and a surface roughness.

  According to the microwave oven having such a configuration, the reflected wave of the wave radiated to the cooking dish and the reflected wave of the wave radiated to the bottom of the heating chamber are different in phase, intensity, and other reception states. Based on the reception state, the arrangement state of the cooking dishes can be determined.

  Preferably, the microwave oven includes a plurality of cooking dishes. Each cooking dish has a different surface state.

  According to the microwave oven having such a configuration, since it is possible to determine which cooking dish is arranged in the cooking chamber, it is placed on each cooking dish without individually inputting the setting of the cooking dish. The food can be heat-treated.

  Preferably, the microwave oven further includes an infrared sensor having a filter that transmits infrared light. The output means uses light waves as radiating waves. The wavelength of the light wave is below the wavelength that can be transmitted by the filter.

  According to the microwave oven having such a configuration, the output means outputs a wave having a wavelength longer than the wavelength of the output wave (for example, 1 μm) that can be detected by the infrared sensor. As a result, the detection of infrared rays by the infrared sensor is not affected by the wave radiated from the output means, so that the accuracy (for example, temperature accuracy) of the detection result of the infrared sensor is prevented from being lowered. Thereby, the microwave oven can perform exact heat processing.

  Preferably, the microwave oven further includes means for storing a heating condition corresponding to the type of food, state detection means for detecting a reception state of the reflected wave based on the reception result, and a reception state of the reflected wave And a type control unit for determining the type of food and a heating control unit for controlling the heating unit so as to heat the food based on the heating condition corresponding to the type of food.

  According to the microwave oven having such a configuration, the type of food disposed in the heating chamber is determined based on the reception state of the reflected wave. Here, the types of food include, for example, solid food and liquid food. The reception state of the reflected wave includes, for example, the attenuation rate of the reflected wave, the number of changes in the detection distance during a predetermined time, the change rate, and the like. In this way, the user can cause the microwave oven to perform the optimum heat treatment without inputting settings for the type of food. Thereby, the microwave oven with improved convenience can be provided.

  Preferably, the state detection unit includes a detection unit for continuously detecting a distance from the reception state to the object that reflects the wave for a predetermined time. The discrimination means includes food discrimination means for discriminating whether the food is a solid food or a fluid food based on the change in distance.

  According to the microwave oven having such a configuration, it is determined whether the food placed in the heating chamber is a solid food or a fluid food based on the amount of change in the detected distance within a predetermined time. . As a result, since the influence of erroneous determination due to detection errors can be suppressed as compared with, for example, a case where the type of food is determined instantaneously, the accuracy of the heat treatment can be improved.

  Preferably, the detection means calculates a change amount of a predetermined time and distance. The determining means determines that the food is a solid food when the amount of change in distance is below a predetermined value. The discrimination means discriminates that the food is a fluid food when the amount of change in distance exceeds a predetermined value.

  According to the microwave oven having such a configuration, the determination of the solid food or the liquid food is performed based on the amount of change in the distance detected within a predetermined time. In comparison, the possibility of erroneous determination due to an error in the detection signal can be reduced.

  Preferably, the detection means calculates a frequency at which the distance and the distance change in advance. The determining means determines that the food is a solid food when the frequency is less than a predetermined value. The discrimination means discriminates that the food is a liquid food when the frequency exceeds a predetermined value.

  According to the microwave oven having such a configuration, the determination of the solid food or the liquid food is performed based on the frequency at which the distance within a predetermined time changes, so that compared with the case where the determination is performed instantaneously. Therefore, the possibility of erroneous determination due to an error in the detection signal can be reduced.

  Preferably, the microwave oven further includes warehousing detection means for detecting that the food is admitted into the heating chamber. The state detection means starts detecting the state of the reflected wave change from when the food is stored in the heating chamber.

  According to the microwave oven having such a configuration, since the data for determining the type of food is taken in after the food is received in the heating chamber, erroneous determination can be prevented. If it does in this way, when food is not arrange | positioned in a heating chamber, since a heat processing is not performed, malfunctioning can be prevented.

  Preferably, the microwave oven further includes an opening / closing detection means for detecting opening / closing of the door portion. The state detection means starts detecting the state of the reflected wave change from when the door is closed.

  According to the microwave oven having such a configuration, since the detection of the distance for determining the type of food is started when the user closes the door portion, the determination can be performed accurately.

  Preferably, the control means prohibits the heating operation by the heating means when the warehousing detection means does not detect the receipt of food.

  According to the microwave oven having such a configuration, the warehousing detection means can determine the presence or absence of warehousing, that is, the presence or absence of food in the heating chamber. In this way, since the heat treatment can be performed only when food is stored in the heating chamber, malfunction of the microwave oven can be prevented.

  According to the microwave oven according to the present invention, the user does not need to input the arrangement state of the cooking dish to the microwave oven for each cooking, so that the convenience of cooking can be improved. Or since the heating control method is automatically selected according to the arrangement | positioning state of a cooking pan, the convenience of cooking can be improved.

  Moreover, according to the microwave oven which concerns on this invention, since the kind of foodstuff arrange | positioned in a heating chamber is discriminate | determined, the optimal cooking according to the kind of the foodstuff can be performed.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same parts are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

<First Embodiment>
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.

  With reference to FIG. 1, the structure of the microwave oven 100 which concerns on the 1st Embodiment of this invention is demonstrated. FIG. 1 is a block diagram showing the configuration of microwave oven 100.

  As shown in FIG. 1, the microwave oven 100 includes a control circuit 110, a distance sensor 120 connected to the control circuit 110, an operation unit 130, a door detection switch 132, an infrared sensor 134, and a cooling fan motor 136. , An oven heater 138, a microwave oscillation circuit 140, and a display unit 142. The control circuit 110 includes a microcomputer 112 and a memory 114. The distance sensor 120 includes a wave radiating unit 122 and a wave receiving unit 124.

  The control circuit 110 detects an instruction input by the user based on a signal from the operation unit 130. The control circuit 110 determines whether or not the door 150 of the microwave oven 100 is open based on a signal from the door detection switch 132. The control circuit 110 detects the temperature in the cooking chamber of the microwave oven 100 based on the signal from the infrared sensor 134. The control circuit 110 detects the distance to the object based on the signal from the wave receiving unit 124. This object includes the bottom surface of the cooking cabinet in addition to the cooking dish placed in the cooking cabinet.

  The control circuit 110 transmits a signal to the distance sensor 120 to emit a wave (for example, light or ultrasonic wave) for measuring the distance in the cooking chamber of the microwave oven 100. The control circuit 110 drives a cooling fan (not shown) for cooling the microwave oven 100 by driving the cooling fan motor 136. The control circuit 110 causes the oven function of the microwave oven 100 to be executed by transmitting a signal to the oven heater 138. The control circuit 110 transmits a signal to the microwave oscillation circuit 140 to cause the microwave to be output into the cooking chamber of the microwave oven 100. The control circuit 110 transmits a predetermined signal to the display unit 142 to display the control state.

  With reference to FIG. 2, the internal structure of microwave oven 100 according to the present embodiment will be described. FIG. 2 is a diagram showing the microwave oven 100 with a cover (not shown) removed.

  As shown in FIG. 2, the microwave oven 100 includes a distance sensor 120 at the top of the cooking cabinet. The attachment position of the distance sensor 120 is preferably near the center of the cooking chamber, for example, but the attachment position is not limited to the center. For example, the end part of a cooking chamber may be sufficient.

  The microwave oven 100 further includes an infrared sensor 134 that detects infrared rays emitted from the cooking chamber and measures the temperature. The attachment position of the infrared sensor 134 is, for example, an obliquely upper part (not shown) of the cooking chamber, but is not limited to this position. For example, it can be considered that the infrared signal from the infrared sensor 134 is attached at a position where the inside of the cooking chamber can be scanned without any problem.

  With reference to FIG. 3, the structure of the microwave oven 100 which concerns on this Embodiment is further demonstrated. FIG. 3 shows a state in which the door 150 of the microwave oven 100 is opened.

  As shown in FIG. 3, the microwave oven 100 includes mounting rails 152 and 154 for arranging cooking dishes to be described later. By arrange | positioning a cooking plate in any attachment part, in addition to the case where a cooking plate is arrange | positioned on the bottom face 103 of a cooking cabinet, the position of a cooking plate can be adjusted to the position suitable for the foodstuff to cook. In addition, the number or position (namely, distance from the bottom face 103) of the attachment rails 152 and 154 comprised in this way is not restricted to what was shown in FIG. Further, the shape of the mounting rails 152 and 154 is not limited to the convex shape as shown in FIG.

  With reference to FIG. 4, the cooking plate attached to microwave oven 100 according to the present embodiment will be described. FIG. 4A shows a ceramic cooking dish 400. FIG. 4B shows a metal cooking dish 410.

  The ceramic cooking dish 400 has a smooth surface finish on the upper surface where food is placed. On the other hand, a heat generating film 401 is applied to the back surface so as to generate heat by absorbing microwaves. On the other hand, the metal cooking dish 410 is enameled on the top surface where food is placed. Therefore, the ceramic cooking dish 400 and the metal cooking dish 410 have different surface states (for example, material, surface treatment mode, cross-sectional shape, etc.).

  If it does in this way, since the state of reflection of the wave radiated | emitted from the distance sensor changes with each cooking dishes, the reception state of the reflected wave by a sensor also changes with every cooking dishes. As a result, even if the cooking dishes having different surface states are arranged on the same mounting portion of the microwave oven 100, the distance sensor 120 detects the reception states of different reflected waves. Therefore, the kind of cooking dish arrange | positioned at the attachment part can be discriminate | determined based on such a reception state.

  Note that the cooking pan attached to the microwave oven 100 is not limited to the one shown in FIG. 4A or 4B, but has a surface finish such that the direction is different when a signal from the distance sensor is reflected. Anything that has been made.

  With reference to FIG. 5, data used by microwave oven 100 according to the present embodiment will be described. FIG. 5A conceptually shows a data structure stored in memory 114 of control circuit 110. FIG. 5B is a diagram for explaining the relationship between the cooking pan and the detection distance based on the data structure. This detection distance refers to the distance acquired from the state of the reflected wave, for example, by irradiating each cooking dish with infrared rays, and is different from the actual distance to each cooking dish.

  As shown in FIG. 5 (A), data representing the correspondence between the cooking dishes 400 and 410 and the attachment positions of the cooking dishes is stored in the memory 114. Here, the maximum value and the minimum value are upper and lower limit values that the distance sensor 120 determines that the cooking dish is installed at the corresponding position. The data representing the type of cooking dish is a cooking dish that can be attached to the microwave oven 100 and can be set in advance. A position means the position where each cooking plate is arrange | positioned. This position includes mounting rails 152 and 154. In addition, when the cooking dish is not disposed in the microwave oven 100, data “NULL” is stored.

  As shown in FIG. 5B, the distance detected by the distance sensor 120 is different for each cooking dish. In this way, it is possible to determine the type of cooking dish placed at a predetermined position or the presence or absence of the cooking dish with respect to the detection result by the distance sensor 120. It should be noted that the number of cooking dishes that can be arranged and the distance between detection distances by the distance sensor 120 are not particularly limited.

  With reference to FIG. 6, the relationship between the case where each cooking plate is arranged in microwave oven 100 and the case where no cooking plate is arranged in microwave oven 100 and the detection result by distance sensor 120 will be described. FIG. 6 (A) is a diagram showing a list of distances detected when cooking plates 400 and 410 having different surface states are arranged at various locations in the cooking cabinet. FIG. 6B shows the distance detected when the cooking pan is not arranged in the microwave oven 100.

  For example, when cooking dish 400 is directly arranged on bottom surface 103 of the cooking chamber of microwave oven 100, the distance detected by distance sensor 120 is 291 mm. When cooking dish 400 is arranged on mounting rail 152 of microwave oven 100, the distance detected by distance sensor 120 is 225 mm. When the cooking dish 400 is disposed on the mounting rail 154, the distance is 103 mm. Similarly, in the case of the cooking dish 410, each detection distance will be 279 mm, 236 mm, and 130 mm.

  On the other hand, when none of the cooking dishes are arranged in the cooking chamber of the microwave oven 100, the distance detected by the distance sensor 120 is 260 mm. Thus, the distance sensor 120 detects different distances when the cooking dish is placed in the microwave oven 100 and when it is not placed. Moreover, when different cooking dishes are arrange | positioned at the same attachment part, the distance detected by a cooking dish differs. Therefore, the presence / absence of the cooking dish and the type of the cooking dish can be determined based on the detection distance of the distance sensor 120.

  The determination of the presence / absence of the cooking dish and the type of cooking dish in this way is not limited to the distance detected by the distance sensor 120. That is, it may be an output value (voltage value, phase, etc.) from a means capable of emitting and receiving a wave.

  With reference to FIG. 7, the control structure of microwave oven 100 according to the present embodiment will be described. FIG. 7 is a flowchart showing a procedure of processing executed by control circuit 110 included in microwave oven 100.

  In step S <b> 702, the control circuit 110 transmits a predetermined control signal to the distance sensor 120 to start wave emission.

  In step S704, the control circuit 110 receives a signal from the wave receiver 124 of the distance sensor 120 that has received the reflected wave.

  In step S706, control circuit 110 detects the distance to the object arranged in the cooking chamber of microwave oven 100 based on the received signal. This object is a cooking dish, for example. Moreover, when the cooking dish is not arrange | positioned in a cooking chamber, a target object becomes the bottom face of a cooking chamber.

  In step S708, control circuit 110 detects the manner of arrangement of the cooking dishes based on the detected distance. This aspect includes whether or not the cooking dish is disposed in the cooking chamber of the microwave oven 100, and in the case where the cooking dish is disposed, in which mounting portion the cooking dish is disposed. It is.

  In step S710, control circuit 110 determines whether or not the cooking dish is placed in the cooking cabinet based on the detected mode. If the cooking pan is arranged (YES in step S710), the process proceeds to step S712. If not (NO in step S710), the process proceeds to step S714.

  In step S712, control circuit 110 heats the inside of the cooking chamber with control (output) according to the position where the cooking pan is disposed. For example, when the cooking pan is disposed on the upper mounting rail 154, the output is smaller than when it is disposed on the lower mounting rail 152.

  In step S714, control circuit 110 executes heating control when the cooking pan is not arranged in the cooking cabinet.

  An operation of microwave oven 100 according to the present embodiment based on the above structure and flowchart will be described. Below, the operation | movement in case the cooking plate 400 is arrange | positioned at the upper mounting rail 154 of the cooking chamber of the microwave oven 100 is demonstrated.

  When the user puts food on the cooking pan 400 and puts it in the cooking chamber of the microwave oven 100 and closes the door, it is detected that the door is closed, and a wave for distance measurement is emitted from the distance sensor (step). S702). When a reflected wave is received (step S704) and the distance from the received signal to the cooking dish 400 is detected (step S706), the cooking dish arranged in the cooking cabinet is based on the distance. 400 is determined (step S708). Since cooking dish 400 is housed in microwave oven 100 (YES in step S710), a heating process is performed in accordance with the conditions when cooking dish 400 is disposed on attachment portion 154 (step S710).

  As described above, microwave oven 100 according to the present embodiment radiates a wave for detecting a distance to a cooking dish arranged in a cooking cabinet, and receives a reflected wave of the wave. In this case, the surface of each cooking dish or cooking cabinet is formed so that each surface state differs. Therefore, even if each cooking dish is arrange | positioned in the same position of a cooking chamber, the detection result by the distance sensor 120 becomes a different distance, respectively. Therefore, by associating the position of each cooking plate and the heating condition in advance in the memory 114, the type of the cooking plate and the arrangement position thereof are determined without the user inputting the setting of the cooking plate. If it does in this way, since it can cook without increasing the load by a user, the operativity of the microwave oven 100 can be improved.

<Second Embodiment>
Hereinafter, a second embodiment of the present invention will be described with reference to FIGS. Note that the hardware configuration of the microwave oven 800 according to the present embodiment is the same as that of the first embodiment described above. Therefore, description thereof will not be repeated.

  Microwave oven 800 according to the present embodiment is different from the first embodiment described above in that the type of food placed in the cooking chamber can be determined. Here, the type of food includes fluid food or solid food. The liquid food includes, for example, a beverage or other liquid food injected into a container. In addition, the solid food is a food having a higher viscosity than the liquid food, and is, for example, rice or other solid foodstuffs placed in a container.

  With reference to FIG. 8, an example in which microwave oven 800 according to the present embodiment is used will be described. FIG. 8A is a diagram illustrating a state where the tea bowl 810 is arranged in the cooking chamber of the microwave oven 800. FIG. 8 (B) is a diagram showing a state in which mugs 820 into which milk is poured are similarly arranged.

  As shown in FIG. 8 (A), the teacup 810 is arranged, for example, at the substantially central portion of the bottom surface of the microwave oven 800 cooking chamber. This position is, for example, a range included in the field of view of a distance sensor (not shown), but the position of the teacup 810 is not limited to this. For example, the restriction of the position of the teacup 810 may be removed by attaching a distance sensor having a wide field of view to the ceiling of the cooking cabinet. If it does in this way, even if it does not arrange | position the teacup 810 in the center part of the bottom face of a cooking chamber, the process mentioned later can be performed.

  The distance detection result by the distance sensor 120 will be described with reference to FIGS. 9 and 10. FIG. 9 is a time chart showing the transition of the distance detected when the mug 820 into which 200 ml of milk has been injected is put in the cooking cabinet of the microwave oven 800. FIG. 10 is a time chart showing the transition of the distance detected when 150 g of rice is placed in the bowl 810.

  As shown in FIG. 9, the detection distance is about 290 mm until about 2 seconds elapse after the distance detection is started. This distance represents that nothing is arranged in the cooking chamber of the microwave oven 800 at this time. Thereafter, when the mug 820 into which milk is poured is placed in the microwave oven 800, the result of the detection distance rapidly decreases to about 160 mm. This is because the liquid level of the mug 820 or milk is detected by the distance sensor 120.

  Thereafter, the graph gradually changes to a level of 200 mm while repeating vibrations up and down. This is because the milk level vibrates when the mug 820 is housed in the microwave oven 800. When this vibration is detected by the distance sensor 120, the vibration is displayed as shown in FIG. In this case, when such a liquid is put into the microwave oven 800, it takes several seconds (for example, about 5 seconds) until the detection distance converges.

  On the other hand, as shown in FIG. 10, when the bowl 810 on which rice is arranged is placed in the microwave oven 800, the detected distance value is reduced to about 160 mm. Thereafter, the value of the distance increases to about 175 mm and maintains the converged state. That is, since rice has a higher viscosity than milk, the vibration that occurs when placed in the microwave oven 800 has a smaller amplitude than the vibration that occurs when the cup 820 into which liquid (for example, milk) is injected is placed. Become.

  Therefore, by setting the relationship as shown in FIG. 9 or FIG. 10 in the memory 114 in advance, for example, as the amplitude, frequency, or rate of change in time, the food arranged in the cooking piece is a liquid food. Whether it is a solid food or a solid food can be easily determined.

  With reference to FIG. 11, a control structure of control circuit 110 realizing microwave oven 800 according to the present embodiment will be described. FIG. 11 is a flowchart showing a procedure of processing executed by control circuit 110. The same processes as those in the first embodiment described above are denoted by the same step numbers, and description thereof will not be repeated.

  In step S1106, control circuit 110 determines whether or not food has been received in the cooking chamber. This determination is made based on the detection result of the distance sensor 120. For example, if there is no change in the preset distance, the control circuit 110 determines that the food is not stored in the microwave oven 800. On the other hand, if the result temporarily changes with respect to the predetermined detection result, it is determined that the food has been received. If food is received (YES in step S1106), the process proceeds to step S1108. If not (NO in step S1106), determination processing is executed again after a predetermined time has elapsed.

  In step S1108, control circuit 110 detects the distance to the food based on the signal from distance sensor 120.

  In step S1110, control circuit 110 determines whether or not the detected distance value is oscillating. This determination is made based on, for example, whether or not the detection distance has changed more than a predetermined number of times within a predetermined time. If the detected distance value is oscillating (YES in step S1110), the process proceeds to S1112. If not (NO in step S1110), the process proceeds to step S1114.

  In step S1112, control circuit 110 executes control to heat the beverage placed in the cooking cabinet by executing predetermined control. At this time, the control circuit 110 reads the heating condition (output, heating time, etc.) stored in advance corresponding to the beverage from the memory 114, and outputs an instruction for the heating condition to the microwave oscillation circuit 140 or the like.

  In step S1114, control circuit 110 executes control for heating the solid food arranged in the cooking cabinet. At this time, the control circuit 110 reads the heating condition (output, heating time, etc.) stored in advance corresponding to the beverage from the memory 114, and outputs an instruction for the heating condition to the microwave oscillation circuit 140 or the like. .

  An operation of microwave oven 800 according to the present embodiment based on the above structure and flowchart will be described. A case where the teacup 810 is put in the microwave oven 100 will be described.

  When the user puts the bowl 810 with rice in the microwave oven 800 and closes the door, the distance sensor 120 emits a wave and starts detecting the distance. Control circuit 110 determines that food has been received (YES in step S1106), and detects the distance to teacup 810 (step S1108).

  In this case, since the vibration of the detected distance value immediately converges (NO in step S1110), a heating process suitable for rice is performed (step S1114).

  As described above, in the microwave oven 800 according to the present embodiment, the object is a solid food such as rice based on the state of change in the signal for detecting the distance to the object accommodated in the cooking cabinet. It is discriminated whether it is a liquid food such as milk. The heat treatment is performed based on a heating condition selected based on the determination result. If it does in this way, since the process according to the kind of food accommodated in a cooking chamber is set automatically, cooking can be performed more optimally. Thereby, the microwave oven with improved convenience can be provided.

  In each of the above embodiments, by detecting a change in the output of the distance sensor 120 that can measure the distance to the object, it is possible to determine the position where the object is placed or to determine the type of the object (ie, the type of the object). Whether the object is a solid food or a fluid food). Such a determination can be made by other than the output of the distance sensor 120. For example, light waves or sound waves may be emitted and the reflected waves may be received to make these determinations.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

It is a block diagram showing the structure of the microwave oven which concerns on the 1st Embodiment of this invention. It is a figure (the 1) showing the external appearance of the microwave oven which concerns on the 1st Embodiment of this invention. It is a figure (the 2) showing the external appearance of the microwave oven which concerns on the 1st Embodiment of this invention. It is a figure showing the cooking plate arrange | positioned at the cooking chamber of the microwave oven shown in FIG. It is a figure for demonstrating the data stored in the memory shown in FIG. It is a figure showing the relationship between the arrangement | positioning condition of the cooking plate shown in FIG. 4, and the detection result of the distance of a distance sensor. It is a flowchart showing the procedure of the process which the control circuit of the microwave oven which concerns on the 1st Embodiment of this invention performs. It is a figure showing the general view of the microwave oven which concerns on the 2nd Embodiment of this invention. It is FIG. (1) for demonstrating the relationship between the foodstuff accommodated in the microwave oven which concerns on the 2nd Embodiment of this invention, and detection distance. It is FIG. (2) for demonstrating the relationship between the foodstuff accommodated in the microwave oven which concerns on the 2nd Embodiment of this invention, and detection distance. It is a flowchart showing the procedure of the process which the control circuit of the microwave oven which concerns on the 2nd Embodiment of this invention performs.

Explanation of symbols

  100,800 Microwave oven, 103 Bottom surface, 110 Control circuit, 112 Microcomputer, 114 Memory, 120 Distance sensor, 122 Wave radiation unit, 124 Wave reception unit, 130 Operation unit, 132 Door detection switch, 134 Infrared sensor, 136 Cooling fan Motor, 138 oven heater, 140 microwave oscillation circuit, 142 display unit, 150 door, 400, 410 cooking dish, 401 heating film, 810 teacup, 820 mug.

Claims (16)

A heating chamber containing food,
A cooking pan disposed in the heating chamber and having a surface state different from the surface state of the bottom surface of the heating chamber;
Heating means for heating the food;
An output means for radiating a wave in the heating chamber, receiving a reflected wave of the wave and outputting a reception result;
Storage means for storing the reception range of the reflection of the wave acquired in advance in association with the cooking plate;
Based on the reception result and the reception range, a determination unit for determining an installation state of the cooking dish;
And a control means for controlling the heating means so as to heat the food based on an installed state of the cooking pan. The storage means stores a range of distances detected in advance corresponding to the cooking dish,
The output means outputs a detection distance detected based on a reception state of the reflected wave of the wave,
The microwave oven according to claim 1, wherein the determination unit includes an installation state determination unit for determining an installation state of the cooking dish based on the stored distance range and the detected distance. The storage means stores a range of distances acquired in advance as an output of the output means when the cooking pan is not arranged in the heating chamber,
The installation state determining means includes presence / absence determining means for determining whether or not the cooking dish is arranged in the heating chamber based on the stored distance range and the detected distance. 2. The microwave oven according to 2. The presence / absence determining means includes
When the detection distance is included in the range of the distance, it is determined that the cooking dish is not arranged in the heating chamber,
The microwave oven according to claim 3, wherein when the detection distance is not included in the range of the distance, it is determined that the cooking dish is disposed in the heating chamber. The heating chamber is formed with a plurality of arrangement portions where the cooking dishes are arranged,
The storage means stores a range of each distance detected when the cooking plate is arranged in each of the arrangement units,
The installation state determination means includes a position determination means for determining which of the arrangement portions the cooking dish is arranged on the basis of the detected distance and the stored range of the distance. Item 3. The microwave oven according to Item 2.   The said position discrimination means discriminate | determines that the said cooking plate is arrange | positioned at the said arrangement | positioning part corresponding to the range of the distance, when the said detection distance is contained in the range of the said distance. microwave.   The microwave oven according to any one of claims 1 to 6, wherein the surface state is any one of a material, a finished state of surface treatment, a shape, and a surface roughness. The microwave oven includes a plurality of the cooking dishes,
The said microwave oven is a microwave oven in any one of Claims 1-7 from which a surface state differs mutually. The microwave oven further includes an infrared sensor having a filter that transmits infrared rays,
The output means uses light waves as radiating waves,
The microwave oven according to claim 1, wherein a wavelength of the light wave is lower than a wavelength that can be transmitted through the filter. The microwave oven further includes
Means for storing heating conditions corresponding to the type of food;
A state detecting means for detecting a reception state of the reflected wave based on the reception result;
Based on the state of reception of the reflected wave, type discrimination means for discriminating the type of the food,
The microwave oven according to claim 1, further comprising: a heating control unit configured to control the heating unit so as to heat the food based on the heating condition corresponding to the determined type of the food. The state detection means includes a detection means for continuously detecting a distance from the reception state to the object reflecting the wave from a predetermined time,
The microwave oven according to claim 10, wherein the type determining means includes food determining means for determining whether the food is a solid food or a liquid food based on the change in the distance. The detection means calculates a change amount of the distance for a predetermined time,
The discrimination means includes
When the amount of change in the distance is less than a predetermined value, it is determined that the food is a solid food,
The microwave oven according to claim 11, wherein when the amount of change in the distance exceeds the predetermined value, the food is determined to be a liquid food. The detection means calculates a frequency at which the distance changes for a predetermined time,
The discrimination means includes
If the frequency is below a predetermined value, determine that the food is a solid food,
The microwave oven according to claim 11, wherein when the frequency exceeds the predetermined value, the food is determined to be a liquid food. The microwave oven further includes warehousing detection means for detecting that the food is warehousing in the heating chamber,
The microwave oven according to any one of claims 10 to 13, wherein the state detection means starts detecting the state of change of the reflected wave from when the food is stored in the heating chamber. The microwave oven further includes an opening / closing detection means for detecting opening / closing of the door portion,
The microwave oven according to any one of claims 10 to 13, wherein the state detection means starts detection of the state of change of the reflected wave from when the door portion is closed.   15. The microwave oven according to claim 14, wherein the control means prohibits the heating operation by the heating means when the warehousing detection means does not detect the receipt of the food.

Images