JP3615492B2 - microwave - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a microwave oven provided with an infrared sensor.
[0002]
[Prior art]
Some conventional microwave ovens can be set to a so-called demo mode for demonstrating various operations to customers at a store or the like.
[0003]
In such a demo mode, without actually operating the magnetron of the microwave oven body, the salesperson operates the operation panel in front of the customer to set the heating time and heating output and display it on the display panel. An effective demonstration can be performed by operating a timer to actually count down the heating time.
[0004]
The demo mode can be set only by special operation of various switches on the operation panel so that the user does not enter the mode unnecessarily during normal use. The method is not known to general users. An example of a microwave oven in which such a demo mode can be set is disclosed in Japanese Patent Publication No. 3-22539 (F24C 7/02).
[0005]
[Problems to be solved by the invention]
However, in the demonstration mode of the conventional microwave oven as described above, the demonstration on the operation panel and the display panel, such as the setting of the heating time and the heating output, which is not related to the actual state of the object to be heated can be performed. It was not possible to perform a demonstration that actually detected the state of the heated object while showing the state of the heated object to the customer.
[0006]
Therefore, the conventional microwave demo mode has a problem that the persuasive power of the salesperson at the store is not always sufficient.
[0007]
SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a microwave oven capable of a convincing demonstration at a shop front by enabling actual temperature measurement of an object to be heated in a heating chamber even during a demonstration mode. .
[0008]
[Means for Solving the Problems]
A microwave oven according to the present invention is connected to a commercial power source via a heating chamber for storing an object to be heated and a door switch that opens and closes in conjunction with opening and closing of the door of the heating chamber, and supplies heating energy to the heating chamber. A heating energy generating means to be supplied, an infrared sensor for detecting the temperature of an object to be heated housed in the heating chamber, a display means for displaying the detected temperature, and various buttons and switches are provided. A keyboard and a control circuit that is connected to the commercial power source before the door switch and that can execute a demo mode while keeping the heating energy generating means in an inactive state, and the control circuit includes the demo mode wherein after the door it is determined that is opened, to start the temperature detection by the infrared sensor in response to the absence of the key input of the keyboard is detected in It is formed.
[0009]
Further, the control circuit, after the temperature sensing initiation of said infrared sensor, a configuration for stopping the temperature detection of the infrared sensor after a predetermined time has elapsed.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a front sectional view schematically showing a configuration of a microwave oven as a premise of each embodiment of the present invention described below.
[0011]
In FIG. 1, a microwave oven 1 has a heating chamber 2 in which a food 3 that is an object to be heated is stored. More specifically, the food 3 is placed on a turntable 5 that is rotated by a turntable motor 4 during heating.
[0012]
The microwave oven 1 is provided with a magnetron 7 that is supplied with power via a high-voltage transformer 6. Microwaves generated by the magnetron 7 are supplied into the heating chamber 2 via a waveguide 8, and the food 3 The microwave heating is performed.
[0013]
On the other hand, a lower heater 9 is provided on the bottom surface of the heating chamber 2, and an upper heater 10 is provided on the ceiling, so that the heater of the food 3 can be heated in addition to microwave heating.
[0014]
In addition, an infrared sensor 11 for detecting the infrared rays from the food 3 and measuring the temperature of the food 3 is provided at a corner portion above the heating chamber.
[0015]
FIG. 2 is a block diagram schematically showing an electrical configuration of the microwave oven shown in FIG.
[0016]
In FIG. 2, one power line from the commercial power supply 12 includes a thermal fuse 13, a door switch 14 that opens and closes in conjunction with opening and closing of a door (not shown) of the heating chamber 2, and a heating start button (not shown). And a relay 15 that closes in response to the pressure on the primary side of the high-voltage transformer 6.
[0017]
On the other hand, the other power line from the commercial power source 12 is connected to the primary of the high-voltage transformer 6 via a 15A fuse 16 and a relay 17 that closes in response to an operation of a switch (not shown) that selects microwave heating. Is connected to the other end. The secondary side of the high voltage transformer 6 is connected to the magnetron 7 so that a high voltage is supplied to the magnetron 7.
[0018]
The commercial power supply 12 is also connected to a control circuit 18 including a microcomputer before the door switch 14 and the relay 15, and the control circuit 18 is always connected regardless of whether the door is opened or closed and the start button is turned on / off. Power is supplied.
[0019]
Similarly, the commercial power source 12 is connected to a series connection including the chopper motor 19 of the infrared sensor 11 and the relay 20 before the door switch 14 and the relay 15. Therefore, regardless of whether the door is opened or closed and the start button is turned on / off, when the relay 20 is closed, the chopper motor for the infrared sensor 11 starts to rotate, and detection of infrared rays from the food 3 that is to be heated is started. The
[0020]
Further, in the subsequent stage of the door switch 14 and the relay 15, a series connection including an illumination lamp 21 inside the heating chamber 2, a blower motor 22 for cooling the magnetron 7, a turntable motor 4 and a relay 23 is provided between the power lines. A series connection composed of the upper heater 10 and the relay 24 and a series connection composed of the lower heater 9 and the relay 25 are connected in parallel to each other.
[0021]
Therefore, when the door switch 14 and the relay 15 linked to the start button are closed, the lamp 21 is lit in the heating chamber 2 and the blower motor 22 is driven. Further, the relays 23, 24, 25, and 17 are closed, whereby the turntable motor 4, the upper heater 10, the lower heater 9, and the magnetron 7 are selectively driven.
[0022]
Opening and closing of these relays 15, 17, 20, 23, 24, 25 is controlled by the control circuit 18 in accordance with the operation of various buttons and switches provided on the keyboard 26. The thermistor 27 is attached to the outer wall of the heating chamber 2 and performs indirect temperature measurement in the heating chamber, and is connected to the control circuit 18.
[0023]
[Embodiment 1]
The operation of the demo mode according to the first embodiment of the present invention in the microwave oven having the above-described electrical configuration will be described. FIG. 3 is a control flow diagram of the control circuit 18 for explaining the operation in such a demo mode.
[0024]
With reference to FIG. 3, first, in step S <b> 1, it is determined whether or not the demo mode is set by a specific operation of the switches on the keyboard 26 by the user. If the demo mode is not set, the program proceeds to another process. If it is determined that the demo mode is set, the program proceeds to the next step S2. During the demonstration mode, the relay 17 is always kept open regardless of the operation of the keyboard 26 so that the magnetron 7 is not energized.
[0025]
Next, in step S2, it is determined whether or not the door of the heating chamber 2 has been opened by the user. If the door is not opened, the program proceeds to another process. If it is determined that the door is opened, the program proceeds to the next step S3. Here, with the door opened, a user, that is, a salesperson at the store, places a demonstration object to be heated (for example, a glass containing water) on the turntable 5 in the heating chamber 2. To do.
[0026]
Next, in step S3, it is determined whether or not a predetermined switch (for example, a button for starting heating) on the keyboard 26 has been operated. If it is not operated, the program proceeds to another process, and if it is determined that the program has been operated, the program proceeds to the next step S4 and the temperature measurement by the infrared sensor is executed.
[0027]
First, in step S4, a predetermined period for performing the temperature measurement operation is set in the timer of the control circuit 18.
[0028]
Next, in step S5, the chopper motor relay 20 is closed, and the chopper motor 19 starts operating. Thereby, the infrared rays from the demonstration object to be heated 3 are intermittently incident on the infrared sensor 11 via a chopper (not shown) that is rotationally driven by the chopper motor 19, and the temperature of the object to be heated is measured. In step S7, the measured temperature is displayed to the user (salesperson) and the customer by a display tube (not shown) of the display panel.
[0029]
Next, in step S8, the timer is counted down, and in step S9, it is determined whether or not the timer count value TM has reached zero. The above steps S4 to S9 are repeated until the count value TM reaches 0. When the count value TM reaches 0, the control circuit 18 opens the relay 20 for the chopper motor in step S10, whereby the temperature measurement by the infrared sensor 11 is performed. End the operation. Then, the standby state for the next processing by the user continues in the demo mode.
[0030]
According to the first embodiment as described above, during the demonstration mode, for example, the temperature of a demonstration target object placed in a heating chamber such as a cup of water is measured while the operation of the magnetron is stopped. Therefore, it is possible to perform a more persuasive demonstration for the customer than in the conventional demo mode limited to the operation panel and the demonstration on the display panel.
[0031]
[Embodiment 2]
Next, the operation in the demo mode according to the second embodiment of the present invention will be described. FIG. 4 is a control flowchart of the control circuit 18 for explaining the operation in such a demo mode.
[0032]
The process from the start to step S12 in FIG. 4 is exactly the same as the process from the start to step S2 in the first embodiment of FIG. 3, and therefore description thereof will not be repeated here.
[0033]
The second embodiment of FIG. 4 differs from the first embodiment of FIG. 3 only in the method for starting the temperature measurement mode by the infrared sensor in step S13. That is, in step S3 of the first embodiment of FIG. 3, the temperature measurement mode is started by a predetermined switch operation by the user, whereas in step S13 of the second embodiment of FIG. It is detected by a weight sensor (not shown) coupled to the turntable 5 that a demonstration object to be heated has been placed on the turntable 5, and the temperature measurement operation in steps S14 to S19 is performed according to the detection. It is configured to do.
[0034]
Since operations in steps S14 to S20 are exactly the same as those in steps S4 to S10 in the first embodiment shown in FIG. 3, the description of the operations will not be repeated here.
[0035]
In the second embodiment as described above, a more convincing demonstration can be performed as compared with the first embodiment as in the first embodiment.
[0036]
[Embodiment 3]
Next, the operation in the demo mode according to the third embodiment of the present invention will be described. FIG. 5 is a control flow diagram of the control circuit 18 for explaining the operation in such a demo mode.
[0037]
Since each process from the start to step S22 in FIG. 5 is exactly the same as the operation from the start to step S2 in the first embodiment of FIG. 3, the description thereof will not be repeated here.
[0038]
The third embodiment of FIG. 5 differs from the first embodiment of FIG. 3 and the second embodiment of FIG. 4 only in the method for starting the temperature measurement mode by the infrared sensor in step S23. That is, in step S3 of the first embodiment of FIG. 3, the temperature measurement mode is started by a predetermined switch operation by the user, and in step S13 of the second embodiment of FIG. While the temperature measurement mode is started by detecting the position, in step S23 of the third embodiment in FIG. 5, it is detected that there is no key input after it is determined in step S22 that the door is opened. Accordingly, the temperature measuring operation in steps S24 to S29 is performed. That is, according to the fifth embodiment, the temperature measurement operation is started directly by opening the door of the heating chamber 2.
[0039]
Since operations in steps S24 to S30 are exactly the same as those in steps S4 to S10 of the first embodiment shown in FIG. 3, the description of the operations will not be repeated here.
[0040]
Also in the third embodiment as described above, a more persuasive demonstration can be performed as compared with the first and second embodiments described above, but in this third embodiment, in particular, the heating chamber The temperature detection by the infrared sensor is started just by opening the door, so for example, the sales person can measure and display the temperature just by putting his hand in the heating room at the store, and it is easier to demonstrate temperature measurement. Is possible.
[0041]
【The invention's effect】
As described above, according to the present invention, during the demonstration mode of the microwave oven, the temperature of an object to be heated for demonstration can be easily measured and displayed while the operation of the magnetron is stopped. Compared to the mode, there is an effect that a more persuasive demonstration can be given to the customer.
[Brief description of the drawings]
FIG. 1 is a front sectional view schematically showing a configuration of a microwave oven as a premise of each embodiment of the present invention.
FIG. 2 is a block diagram schematically showing an electrical configuration of the microwave oven shown in FIG. 1;
FIG. 3 is a flowchart for explaining an operation in a demo mode according to the first embodiment of the present invention.
FIG. 4 is a flowchart for explaining an operation in a demo mode according to a second embodiment of the present invention.
FIG. 5 is a flowchart for explaining an operation in a demo mode according to a third embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Microwave oven 2 Heating chamber 3 Heated object 4 Turntable motor 5 Turntable 6 High voltage transformer 7 Magnetron 8 Waveguide 9 Lower heater 10 Upper heater 11 Infrared sensor 12 Commercial power supply 13 Thermal fuse 14 Door switches 15, 17, 20, 23, 24, 25 Relay 16 Fuse 18 Control circuit 19 Chopper motor 21 Lamp 22 Blower motor 26 Keyboard 27 Thermistor

Claims (2)

A microwave oven with demo mode for customer demonstration,
A heating chamber for storing an object to be heated; and heating energy generating means connected to a commercial power source via a door switch that opens and closes in conjunction with opening and closing of the door of the heating chamber and supplies heating energy into the heating chamber. An infrared sensor for detecting the temperature of an object to be heated stored in the heating chamber, a display means for displaying the detected temperature, a keyboard provided with various buttons and switches, and a door switch A control circuit that is connected to the commercial power source in the previous stage and that can execute the demo mode while keeping the heating energy generating means in an inactive state,
The control circuit starts temperature detection by the infrared sensor in response to detecting that there is no key input on the keyboard after it is determined that the door is opened during the demonstration mode. Features a microwave oven. The microwave oven according to claim 1, wherein the control circuit stops the temperature detection operation of the infrared sensor after a predetermined time has elapsed after the temperature detection of the infrared sensor is started.

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