JPH0789983B2 - Electric rice cooker - Google Patents

Description

TECHNICAL FIELD The present invention relates to an electric rice cooker in which rice cooking operation is controlled by a microcomputer.

<Conventional technology> Conventionally, optimal heating control is performed to cook delicious rice, and various types of cooking that require different heating control, such as porridge and rice, are possible. Therefore, an electric rice cooker using a microcomputer is used.

However, in a general household where an electric rice cooker is used, various noises such as noises generated from other electric appliances and natural noises such as lightning exist, and therefore, when the microcomputer runs away due to these noises. There is. Therefore, generally, in the electric rice cooker as described above, it is necessary to provide a reset switch for resetting the microcomputer. Also, the microcomputer must be reset when the battery for operating the microcomputer is replaced or when a heating operation different from the desired operation is selected due to an operation error of the operation switch. Further, in the product assembling process, it is necessary to initialize the microcomputer for inspection and set the time and mode.

However, if the microcomputer is reset during the normal heating control operation, the subsequent control operation will not be performed.Therefore, sufficient care must be taken to prevent the reset switch from being operated by mistake. is there. Therefore, normally, the reset switch is arranged so that it cannot be easily operated. That is, for example, the reset switch described above is housed and arranged in the case of the electric rice cooker, and can be operated by using a tool such as a pin through the pore formed in the bottom of the case. ing.

<Problems to be Solved by the Invention> However, as described above, the reset switch is arranged in a position that is extremely difficult to see, so that even if the reset of the microcomputer actually needs to be performed, the position of the reset switch is set by the user. In some cases, the reset switch may not be located, and even if the reset switcher can be located, it cannot be operated without a device such as a pin. Also, since it is necessary to operate from the bottom of the case, it is necessary to turn over the rice cooker, and in the state where the contents to be heated are stored,
It was difficult to operate.

Further, as described above, it is necessary to dispose the reset switch so as to prevent an erroneous operation, and a special switch is provided for resetting the microcomputer, which causes a problem of high cost.

Therefore, the present invention solves the above-mentioned technical problems, allows the microcomputer to be easily reset, does not worry about erroneous operation thereof, and is also advantageous in cost reduction by eliminating a dedicated reset switch. The purpose is to provide a simple electric rice cooker.

<Means for Solving the Problems> The electric rice cooker of the present invention for achieving the above object is controlled by a microcomputer to perform a heating operation, and is arranged at a position where it can be easily operated from the outside of the case. In an electric rice cooker having at least two or more operation switches for setting rice cooking conditions, the operation is performed when any two operation switches of the operation switches for setting the rice cooking conditions are simultaneously operated. A resetting means for resetting the microcomputer, and one of the operation switches operated simultaneously for resetting the microcomputer,
It is characterized by a cancel switch for canceling the set rice cooking conditions.

<Operation> According to the above configuration, the microcomputer can be operated by simultaneously operating any two operation switches of the plurality of existing operation switches arranged at a position where they can be easily operated from the outside of the case. Can be reset. Therefore, the operation for resetting the microcomputer becomes extremely easy. Moreover, since the microcomputer is reset by an operation that is not normally performed, such as operating the two operation switches at the same time, there is no fear that the reset operation is mistakenly performed.

In particular, the operation of resetting the microcomputer
This is an operation for canceling all the contents of the operation when the microcomputer operates by storing the external conditions and the like. Therefore, one of the operation switches that are simultaneously operated for resetting the microcomputer is a cancel switch for canceling the set rice cooking conditions.
By selecting the cancel switch as one of the two arbitrary switches for the reset operation, the reset operation can be confirmed and then reset, and the cancel operation can be performed easily and surely.

<Examples> Detailed description will be given below with reference to the accompanying drawings showing examples.

FIG. 1 is an electric circuit diagram showing an electric configuration of an electric rice cooker according to an embodiment of the present invention. This electric rice cooker realizes, for example, cooking of porridge and rice porridge, a quick rice cooking operation without a water absorbing step, and a normal rice cooking operation including a water absorbing step, by program control by the microcomputer 7. A plurality of operation switches 31 to 34 for setting rice cooking conditions are provided outside the case of the rice cooker at positions where they can be easily operated. Among the operation switches 31 to 34, the operation switches 31 and 34 are adapted to interlock with the switches 36 and 37 constituting the reset circuit 35 for resetting the microcomputer 7, and the operation switches 31 and 34 are connected to each other. The microcomputer 7 is reset by operating at the same time.

The power supply voltage Vcc to the microcomputer 7 is stabilized by the constant voltage circuit 4 after the AC voltage from the commercial AC power supply (AC100V) stepped down by the step-down transformer 1 is rectified by the diode bridge 2 and smoothed by the smoothing capacitor 3. It is provided by way of power lines 5 to 6.

The AC voltage from the commercial AC power supply is also applied to the rice cooking heater 8 used for cooking rice and the warming heater 9 used for warming the cooked rice. A connecting piece 11 of a relay 10 is connected to the rice cooking heater 8 in series.
A triac 12 is connected in series to the heat retaining heater 9. A transistor 14 that is turned on / off by a control signal from the microcomputer 7 is connected in series to the coil 13 of the relay 10. By turning on the transistor 13, the coil 13 is excited and the rice heating heater 8 is turned on. be able to. The diode 15 connected in parallel with the transistor 14 is for absorbing the counter electromotive force generated by the coil 13 when the relay 10 is switched by the transistor 14.

To the gate of the triac 12 connected in series with the warming heater 9, a transistor 16 controlled to be turned on / off by a control signal from the microcomputer 7 is connected. Therefore, the microcomputer 7 controls the conduction / interruption timing of the transistor 16 to control the conduction phase angle of the triac 12 and the heat generation amount of the heat retention heater 9.

The microcomputer 7 is also connected to a rice cooking light emitting diode 18 which is turned on when the rice cooking heater 8 is energized, and which is turned on when the warming heater 9 is energized. 19 connected. In FIG. 1, 27 is a pan detection sensor that detects whether or not the inner pan is set, and 28 is a thermosensitive element that contacts the lower surface of the inner pan and detects the temperature.

Among the operation switches 31 to 34 described above, for example, the operation switch 31 is a menu switch that can cyclically change and set the plurality of rice cooking operations described above, and the operation switch 32 is the rice cooking selected by operating the switch 31. The operation switches 33, 34 are start switches for starting the operation, and the operation switches 33, 34 are switches for setting the time in a timer provided in the microcomputer 7 for setting the rice cooking start time. Is for advancing that time, and switch 34 is for advancing that time.

The set time of the timer is displayed on the timer display 20 realized by, for example, a liquid crystal display device. The timer display 20 displays a normal time except when the timer is set, for example. The microcomputer 7 is connected to a timer light emitting diode 21 which is turned on when the time is set in the timer,
By visually recognizing this light emitting diode 21, the user
It is possible to know whether or not settings such as the rice cooking start time have been made.

The reset circuit 35 is a power supply voltage supplied through the resistor 38.
A voltage from a reset IC 39, which detects and outputs a predetermined voltage from Vcc, is applied via a line 40, and has a time constant circuit including a resistor 41 and a capacitor 42. The capacitor 42 also prevents noise from accidentally resetting the microcomputer 7. Switches 36 and 37 are connected in series between the line 40 and the ground line 43. As described above, the switch 36 is a switch that conducts in synchronization with the operation of the operation switch 31 for menu selection, and the switch 37 operates the operation switch 34 for delaying the timer setting time. And a switch that conducts in conjunction with this.

In a normal operation state, the capacitor 42 is in a charged state, and the reset terminal RST of the microcomputer 7 is stably supplied with a voltage equal to the output voltage of the reset IC 39. From this state, when the switches 36 and 37 are turned on at the same time, the electric charge accumulated in the capacitor 42 is discharged from the resistor 41 via the switches 36 and 37. by this,
The voltage applied to the reset terminal RST of the microcomputer 7 is lower than the reference voltage preset in the microcomputer 7. Microcomputer 7
Are reset by continuously lowering the voltage of the reset terminal RST below the reference voltage for a predetermined time. Therefore, the microcomputer 7 can be reset by continuously turning on the switches 36 and 37 for a predetermined time.

As described above, in the electric rice cooker of the present embodiment, when the microcomputer 7 goes into a runaway state due to noise from other electric devices or natural noise such as lightning, the operation switch 31, By continuously operating 34 simultaneously for a certain time or longer,
The microcomputer 7 can be reset to return to the normal operating state. Operation switches 31-34
Since the electric rice cooker is arranged at a position where it can be easily operated from the outside on the surface of the case, the above reset operation is not complicated.

Moreover, since the reset of the microcomputer 7 is achieved by an operation that is not normally performed, such as operating the two operation switches 31 and 34 at the same time, for example, when the microcomputer 7 is performing normal heating control, There is no problem such as being accidentally reset.

Further, with the above configuration, it is not necessary to dispose a special switch on the bottom portion of the case or the like as in the conventional case, so that it is possible to contribute to cost reduction.

The present invention is not limited to the above embodiment. For example, in the above-mentioned embodiment, the operation switches 31-34
The microcomputer 7 is reset by the simultaneous operation of the operation switches 31 and 34, but for resetting the microcomputer 7, a combination of any two other switches of the operation switches 31 to 34 is used. May be selected.

Further, in the above-described embodiment, the case where four operation switches are provided has been described, but at least two operation switches may be provided, and the microcomputer 7 is reset by the simultaneous operation of these two operation switches. You can do it. In this case, if one of the two switches operated for resetting the microcomputer 7 is used as a cancel switch for canceling the set rice cooking conditions, the microcomputer 7
The function of the switch for resetting the is suitable, and the operator does not feel uncomfortable.

Various other design changes can be made without departing from the scope of the present invention.

<Effects of the Invention> As described above, according to the electric rice cooker of the present invention, when the microcomputer is reset, among the plurality of existing operation switches arranged at a position that can be easily operated from the outside of the case. Since it is only necessary to operate any two operation switches at the same time, it is not necessary to search for a reset switch, turn over the electric rice cooker, or use a device such as a pin as in the conventional case. Therefore, the operation for resetting the microcomputer can be extremely easily performed by the user.

Further, also in the assembly process, the microcomputer can be easily reset, so that the work in production can be reduced and the cost can be reduced.

Moreover, resetting the microcomputer requires an operation that is not normally performed, that is, operating the two operation switches at the same time, so that there is no fear that the reset operation is mistakenly performed.

Furthermore, since the existing two operation switches are used, it is not necessary to dispose a special switch for resetting on the bottom of the case or the like so that it can be easily operated as in the conventional case, or an external switch is used. Since it is not necessary to provide a dedicated reset switch together with an operation switch provided at a position where it can be easily operated, it is possible to contribute to cost reduction.

In particular, the operation of resetting the microcomputer
This is an operation for canceling all the contents of the operation when the microcomputer operates by storing the external conditions and the like. Therefore, the fact that one of the operation switches that are operated simultaneously for resetting the microcomputer is a cancel switch for canceling the set rice cooking conditions means that there are two switches that perform reset operation. By selecting the cancel switch as one, the reset operation can be confirmed and then reset, and the cancel operation can be performed easily and surely.

[Brief description of drawings]

FIG. 1 is an electric circuit diagram showing an electric configuration of an electric rice cooker according to an embodiment of the present invention. 7 ... Microcomputer, 8 ... Rice cooker, 9 ...
… Heat insulation heater, 31 to 34 …… Operation switch, 35 …… Reset circuit, 36, 37 …… Switch

Claims (1)

[Claims] 1. An electric rice cooker which is controlled by a microcomputer to perform a heating operation, and which has at least two or more operation switches for setting rice cooking conditions and arranged at a position where it can be easily operated from the outside of the case. In the above, in order to reset the microcomputer, there is provided reset means for operating when any two operation switches among the operation switches for setting the rice cooking conditions are simultaneously operated, and resetting the microcomputer. One of the operating switches operated simultaneously is
An electric rice cooker characterized by a cancel switch for canceling the set rice cooking conditions.