JPH0546204B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to an electric cooker such as an electric rice cooker having a display means for displaying cooking steps.

(b) Conventional technology In recent years, a control circuit configured with a microcomputer has been used to preheat a pot and make the rice in the pot absorb enough moisture, and then to cook the rice. An electric rice cooker is provided that sequentially performs a heating process, a heating process, and a warming process. By the way, among such electric rice cookers, there is one that displays the progressing process using a display means such as a light emitting diode, as disclosed in Japanese Patent Application Laid-Open No. 59-155221. be. It is desirable for such electric rice cookers to always drive the display means at the store for display purposes or to explain the operation to consumers.
There is no current rice cooker that drives a display means without driving a heating means such as a heater.

(d) Problems to be Solved by the Invention The present invention takes the above drawbacks into consideration and provides an electric cooker that can control the control content of the display means without driving the heating means.

(E) Means for Solving the Problems The present invention is an electric cooking appliance, which detects the normal or abnormal state of the temperature detecting means by the state detecting means, and controls the first control means when the temperature is normal and when it is abnormal. The second control means is driven, and the state detection means can arbitrarily determine an abnormality by operating means.

(F) Effect Since the present invention is constructed as described above,
When the operation means is operated to cause the state detection means to determine an abnormality, the state detection means drives the second control means while the operation of the first control means is stopped. As a result, the display contents of the display means can be controlled while the operation of the heating means is stopped.

(f) Examples Examples of the present invention will be described based on the drawings. First, Fig. 1 is a partial cross-sectional view of an electric rice cooker, and 1 in the figure consists of a cylindrical inner case 2 with a bottom, a cylindrical outer case 3, and a bottom cover 4 that covers the bottom opening of the outer case. The main body of the rice cooker, 5 is a lid, 6 is a pot housed in the inner case 2, 7 is a heater (heating means) for heating the bottom surface of the pot, and 8 is provided so as to be in pressure contact with the outer bottom surface of the pot 6. A thermistor 14, which will be described later, is heat-conductingly attached inside the heat-sensitive part, and the temperature of the pot 6 can be sensed by this thermistor. 9 is a case for storing electrical components, 1
0A, 10B, 10C, 10D are the outer case 3
A light emitting diode (display means) provided on the side of the rice cooker facing the outside displays the preheating process, rice cooking process, steaming process, and warming process. A first operation knob 11 is slidably provided on the side surface of the outer case 3, and is used to operate a power switch 28, which will be described later. A second operating knob 12 is slidably provided on the bottom surface of the outer case 3, and is used to operate a switch 26, which will be described later.

Next, FIG. 2 is a schematic electrical circuit diagram of the electric rice cooker mentioned above, in which 13 is a bridge circuit with the thermistor 14 as one side, and 15 is a bipolar power supply drive with the output of the bridge circuit as input. With a differential amplifier, when the thermistor 14 changes between -10 and 200 degrees Celsius, the differential input is amplified without saturation, and when it is out of that range, the power supply voltage It is adjusted so that it is saturated. As mentioned above-
The temperature range of 10 to 200°C is determined based on the minimum and maximum temperatures to be detected on the outer bottom surface of the pot 6. The bridge circuit 13 and the differential amplifier 15 constitute a temperature detection means for detecting the temperature of the pot 6. 16 is the differential amplifier 15
The thermistor 14 is an amplifier (state detection means) which amplifies the absolute value of the output of the pan 6 and outputs H if the result is sufficiently large (that is, if it is saturated).
This is to detect whether the temperature is lower than the minimum temperature to be detected on the outer bottom surface of the device or higher than the maximum temperature. That is, this is thermistor 1
4 has a short-circuit failure and the resistance value becomes 0, and the differential input of the differential amplifier 15 becomes sufficiently large, or the thermistor 14 has a disconnection failure, and the resistance value becomes infinite and the differential input becomes sufficient. This corresponds to detecting when the value increases. 17 is a control circuit configured by, for example, a microcomputer, which detects the output of the amplifier 16 via an inverter 18;
L from the amplifier 16 is clogged and H from the inverter 18
is output, the output of the differential amplifier 15 is changed to A/
It is detected through the D converter 19, and based on the detected signal, the switching element 20 connected in series to the heater 7 is controlled to sequentially execute a preheating process, a rice cooking process, a steaming process, and a warming process. It lights up the light emitting diode corresponding to the process. However, this control circuit 17 stops operating even during cooking when L is output from the inverter 18, so the switching element 20 and the light emitting diodes 10A, 10B, 10
C and 10D will be turned off. The control circuit 17, inverter 18, A/D converter 19, and switching element 20 constitute a first control means. 21 is a ring counter second control means with a preset function; a ring counter 22;
Preset circuit 23, first to fourth output circuits 24
It is composed of A, 24B, 24C, 24D and an oscillation circuit 25. In this ring counter 21 with a preset function, when an H level is output from the amplifier 16, the preset circuit 23 is turned on to preset the ring counter 22 and the first output circuit 24A.
Turn on. At this time, the second to fourth output circuits 24
B, 24C, and 24D are all off, so only the light emitting diode 10A connected to the first output circuit 24A for displaying the preheating process is lit. In this state, when the clock pulse of the oscillation circuit 25 is input to the ring counter 22, only the second output circuit 24B is turned on, and only the light emitting diode 10B for displaying the rice cooking process is lit. For example, if the oscillation period of the oscillation circuit 25 is set to about 5 seconds, the light emitting diodes 1 will be activated every 5 seconds for displaying the preheating process, the rice cooking process, the steaming process, and the warming process.
0A, 10B, 10C, and 10D will be lit repeatedly in this order. 26 is a switch connected in series to the thermistor 14, and is connected to the second operating knob 1.
2 constitutes an operating means. 27 is a DC power supply circuit, and 28 is a power switch.

Therefore, the thermistor 14 turns on the switch 26 by an external factor or by operating the second knob 12.
When it opens by turning OFF, differential amplifier 1
5 is saturated on one side, so the amplifier 16 outputs H. When the control circuit 17 detects this, the operation is stopped, so the heater 7 and the light emitting diode 10
A, 10B, 10C, and 10D are turned off, but the preset circuit 23 is activated in response to the H output of the amplifier 16, so the light emitting diode 10A for preheating process indication lights up first, and then the rice cooking starts every 5 seconds. The light emitting diodes 10B, 10C, and 10D for process display, unevenness process display, and heat retention process display light up in sequence, and thereafter also for preheating process display, rice cooking process display, unevenness process display, and heat retention process display. The lights will light up repeatedly in this order. For this operation, switch 26 is ON.
If the switch 26 is off, it can be stopped by replacing the thermistor 14, and if the switch 26 is off, it can be stopped by turning on the switch 26.

Therefore, at the store, the second operation knob 12
Operate to keep switch 26 OFF at all times,
Turn on the power switch 28 using the first operation knob 11.
When turned on, each of the light emitting diodes 10A, 10B, 10C, and 10D is 5 with the heater 7 turned off.
The lights will light up every second, increasing the display effect. Also, when using it at home, by always keeping the switch 26 ON, the heater 7 can be turned on in the event of a short circuit or disconnection of the thermistor 14.
OFF, and the light emitting diodes 10A, 10B,
The abnormal state of the thermistor 14 can be notified by lighting each of 10C and 10D every 5 seconds.

In the above configuration, only the control circuit is configured by a microcomputer, but the differential amplifier, amplifier, ring counter with preset function, etc. may also be configured by the microcomputer. At this time, in the present invention, the temperature input of the microcomputer can also be used as an input for arbitrarily switching between the first control means and the second control means.

Further, in the above configuration, the switch of the operating means is connected in series to the thermistor, but it may be connected in parallel, or the operating means may be a connector that allows the thermistor to be attached or detached after removing the bottom cover, for example. good.

(g) Effects of the Invention As described above, the present invention detects whether the temperature detection means is in a normal or abnormal state, and when normal, the first control means is controlled to
Since it has a state detection means that drives the second control means when an abnormality occurs, and an operation means that allows the state detection means to arbitrarily determine an abnormality, it is possible to improve the display effect at the store and also improve the display effect. Operations can be easily explained to consumers.
Furthermore, when used at home, it is possible to detect an abnormal state of the temperature detection means.

[Brief explanation of the drawing]

FIG. 1 is a partial sectional view of the electric cooking device of the present invention, and FIG. 2 is a schematic electric circuit diagram thereof. 6... Pot, 13, 15... Temperature detection means, 7...
...Heating means, 10A, 10B, 10C, 10D...
...display means, 16...state detection means, 17,1
8, 19, 20...first control means, 21...second
Control means, 12, 26... operation means.

Claims (1)

[Scope of Claims] 1. A pot, heating means for heating the pot, temperature detecting means for detecting the temperature of the pot, display means for displaying the cooking process, a first control means for driving the heating means and the display means; a second control means for controlling the display contents of the display means; and a first control means for detecting whether the temperature detection means is in a normal or abnormal state, and when normal, the first control means of,
An electric cooking appliance comprising: a state detecting means for driving the second control means when an abnormality occurs; and an operating means for causing the state detecting means to arbitrarily determine an abnormality. 2. The electric cooking appliance according to claim 1, wherein the temperature detection means includes a thermistor, and the state detection means determines an abnormality when the thermistor is short-circuited or disconnected. 3. The electric cooking appliance according to claim 2, wherein the operating means is a switch connected in series or parallel to the thermistor. 4. The electric cooking appliance according to claim 2, wherein the operating means is a connector that allows the thermist to be attached or detached.