JP2002329571A - Induction cooker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an induction cooker having simple constitution, saving space, emitting light having various colors, and providing a display for clearly notifying heating power feeling in heating, a setting state, a heating state, and a setting level of heating power even when atmospheric brightness is varied. SOLUTION: A multi-color light emitting unit 17 comprising two or more light emitting sources 17a, 17b emitting different luminous colors is installed, the multi-color light emitting unit 17 varies in point of time a duty factor with a signal from a control part 14, light is emitted so as to look like different colors in point of time to irradiate a liquid crystal display element 16, and the irradiated liquid crystal display element 16 looks like colors formed by synthesizing the luminous colors of the light emitting sources 17a, 17b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heating display of an induction heating cooker.

[0002]

2. Description of the Related Art In an induction heating cooker, a high frequency current is supplied to a heating coil by driving a switching element at a high frequency, a magnetic flux is generated by the high frequency current, and iron or stainless steel is brought close to the heating coil through the magnetic flux. An eddy current is generated in a load such as a hot pot, and the load is heated by the heat generation action of the load itself.

In a conventional induction heating cooker, a setting state of a heating power level and a display of the heating state are performed by a liquid crystal display element or the like.

An example of this conventional example will be described with reference to FIG. FIG. 4 is a circuit block diagram of a conventional induction heating cooker.

In FIG. 1, an AC power supply is supplied from a power supply 1 to a rectifier circuit 2, converted into a DC power supply by the rectifier circuit 2, and smoothed by a smoothing capacitor 3. And
This DC power is supplied to a resonance circuit 6 formed by the heating coil 5 and the resonance capacitor 4.

In this state, the control section 14 grasps the signals of the primary current detecting element 11, the coil current detecting element 12 and the temperature detecting element 13 while controlling the input power according to the level of the heating power set by the operation section 15. To control
A signal is output to the drive unit 10, and the inverter circuit 9 formed by the switching element 8 and the snubber capacitor 7 is operated via the drive unit 10. The inverter circuit 9 generates a high-frequency resonance current in the resonance circuit 6 to heat the load 20 placed on the top plate 18 above the heating coil 5.

The control unit 14 controls the liquid crystal display element 16 when setting the heating power level using the operation unit 15 and during the heating operation.
And a signal is output to the light emitting device 21 so that the liquid crystal display element 16
, A display corresponding to the operation is performed, the light emitting device 21 emits light, and the liquid crystal display element 16 is illuminated from behind to make the display content visible.

As described above, the setting state of the heating power level and the display of the heating state are performed by the light emitting device 21 using the liquid crystal display element 16.
, And the contents are represented by the liquid crystal display element 16.

However, such an induction heating cooker has the following problems.

When the heating power level is set and heating of the load 20 is started, the display means indicating that heating is being performed or the set level of the heating power is only displayed on the liquid crystal display element 16, and the heating source does not emit red heat. For this reason, it is not possible to obtain a feeling of fire such as a gas flame or the sheathed heater glowing red, and it is difficult to recognize the set level of the heating power at a glance.

To solve this problem, Japanese Patent Laid-Open Publication No.
Japanese Patent Application Laid-Open No. 7-094267 has an example in which a multi-step light emitting means for irradiating a liquid crystal display element with multi-step luminance is provided. In this example, a liquid crystal display element is irradiated with light emission luminance corresponding to electric power, and a heating state is distinguished by a change in light emission luminance.

Japanese Patent Application Laid-Open No. 07-114983 discloses an example in which a plurality of light-emitting elements are provided with light-emitting portions each colored with different colors. This example will be described with reference to FIG.
FIG. 5 is a diagram showing a light emitting portion of a circuit diagram in one embodiment of Japanese Patent Application Laid-Open No. 07-114983.

In the figure, the light emitting portion is a first color light emitting element 2.
2 and the second color light emitting element 23. Although not shown, the induction heating cooker includes a temperature detecting element for detecting the temperature of the top plate, and the temperature detected by the temperature detecting element is divided into two temperature ranges.

The lighting of the first color light emitting element 22 and the lighting of the second color light emitting element 23 correspond to each of two temperature ranges. When the detected temperature of the top plate is within the high temperature range, the first color light emitting element 22 is turned on, and when the detected temperature is within the low temperature range, the second color light emitting element 23 is turned on. That is, when the first color light emitting element 22 is turned on, it means danger, and when the second color light emitting element 23 is turned on, it means safe.

As described above, it is possible to easily determine whether or not the hand can touch the top plate.

[0016]

As described above, an example of a display of an induction heating cooker provided with a multi-stage light emitting means for irradiating a conventional liquid crystal display device with multi-stage luminance is to reduce the feeling of fire during heating. Although the brightness of the light emitting device 21 for irradiating the liquid crystal display element 16 is changed according to the set level of the heating power or the heating power, the color is a single color, and the difference in brightness is caused when the brightness of the surroundings changes. There are times when it is hard to recognize.

Also, an example of a display of an induction heating cooker having a plurality of light-emitting elements each having a light-emitting portion colored in different colors is described in the case where a light-emitting portion representing many colors is formed. Are required, so that the cost is increased and a space for arranging many light emitting elements is required, but it is apparent that this has practical limitations.

The present invention has been made to solve the above-mentioned disadvantages, and has a simple configuration without taking up a large space, and a display that makes it easier to recognize the feeling of heat, the setting state, the heating state, and the setting level of the heating power during heating. The purpose is to provide.

[0019]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and comprises a rectifier circuit for converting an AC power supply to a DC power supply. This DC power supply is formed by a heating coil and a resonance capacitor. Supply to the resonant circuit
A control unit that is formed by a switching element or the like, and includes an inverter circuit that generates a high-frequency resonance current in the resonance circuit and heats a load placed on a top plate above the heating coil, and controls input power and the like. In an induction heating cooker provided with an operation unit for setting the level of heating power and the like, and provided with a liquid crystal display element for performing display by a signal from the control unit, the induction heating cooker is formed by two or more light emission sources having different emission colors. A multi-color light-emitting device, and the multi-color light-emitting device changes the duty ratio with time according to a signal from the control unit, emits light such that the color changes with time, and turns the liquid crystal display element on. The illuminated and illuminated liquid crystal display element is configured so that the emission color of each of the emission sources can be viewed as a combined color.

This makes it easier to recognize the feeling of heat at the time of heating, the setting state, the heating state, and the like.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS As described above, the present invention provides a multicolor light emitting device formed by two or more light emitting sources having different emission colors, and the multicolor light emitting device is energized by a signal from the control unit. By changing the rate over time, the liquid crystal display element is illuminated by emitting light so that the color appears to change over time, and the illuminated liquid crystal display element is combined with the respective emission colors of the light emitting source. It is configured to be visible in color.

Thus, the heating state, the feeling of heat and the like at the time of heating can be recognized by a visual color image as in the case of the gas flame, and the feeling of heat, the setting state and the heating state can be more easily recognized. In addition, a simple configuration does not take up a large space.

In addition, since the color is changed according to the elapsed time from the start of heating, it is easy to understand the timing of adjusting the heating power, the timing of putting in the ingredients, the timing of adding the seasoning, and the like in the cooking.

[0024]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a circuit block diagram showing one embodiment of the present invention,
FIG. 2 is a diagram showing details of a display portion of one embodiment of the present invention, and FIG. 3 is a diagram showing a signal waveform to a multicolor light emitting device of one embodiment of the present invention.

Referring to FIG. 1, reference numeral 1 denotes an AC power supply, both ends of which are connected to a rectifier circuit 2, one end of a smoothing capacitor 3 is connected to the + terminal of the rectifier circuit 2, and the other end is connected to the-terminal of the rectifier circuit 2. To form a DC power supply.

Reference numeral 4 denotes a resonance capacitor, two of which are connected in series, and one end of which is connected to the high voltage side of the DC power source (+
Terminal part. The same applies hereinafter. ), The other end is connected to the low-voltage side of the DC power supply (the negative terminal of the rectifier circuit 2; the same applies hereinafter), and two series connection points are connected to the heating coil 5 described later.
Is connected to the first terminal.

Reference numeral 5 denotes a heating coil, and a resonance circuit 6 is formed by the heating coil and the resonance capacitor 4.

Reference numeral 7 denotes a snubber capacitor, two of which are connected in series, one end of which is connected to the high voltage side of the DC power supply, the other end of which is connected to the low voltage side of the DC power supply, and two series connection points. Is connected to the second terminal of the heating coil 5.

Reference numeral 8 denotes a switching element having an anti-parallel diode, two of which are connected in series, one end of which is connected to the high voltage side of the DC power supply, and the other end of which is connected to the low voltage side of the DC power supply. , Two series connection points are connected to the second terminal of the heating coil 5. The gates of the two switching elements 8 are connected to the output of the driving unit 10 described later.

Reference numeral 9 denotes an inverter circuit formed by the switching element 8 and the like. Specifically, it is formed by two switching elements 8 and two snubber capacitors 7.

Reference numeral 10 denotes a drive unit. This input unit is connected to the output unit of the control unit 14 described later, and the output unit is connected to the gate unit of the switching element 8.

Reference numeral 11 denotes a primary current detecting element, which is installed so as to detect a current flowing between the power supply 1 and the rectifier circuit 2, and has an output section connected to an input section of the control section 14, which will be described later.

Numeral 12 denotes a coil current detecting element, which is installed so as to detect a current flowing through the heating coil 5, and has an output section connected to an input section of the control section 14, which will be described later.

Reference numeral 13 denotes a temperature detecting element,
8 is provided below the top plate 18 substantially above the center of the heating coil 5 so as to detect the temperature of the heating coil 8, and its output is connected to the input of the control unit 14 described later.

Reference numeral 14 denotes a control unit, which has its input unit connected to the primary current detecting element 11, the coil current detecting element 12,
The output section is connected to the temperature detecting element 13 and the operation section 15, and the output section is connected to the driving section 10, the liquid crystal display element 16 described later, and the multicolor light emitting device 17 described below, and controls these and input power. An operation unit 15 is connected to an input unit of the control unit 14 and sets a heating power level and the like.

Reference numeral 16 denotes a liquid crystal display element whose input section is connected to an output section of the control section 14 and performs display according to a signal from the control section 14. The contents of this display are the setting state, the heating state, the setting level of the heating power, and the like.

Reference numeral 17 denotes a multicolor light-emitting device whose input section is connected to the output section of the control section 14 and is formed by two or more light-emitting sources 17a and 17b having different emission colors, and emits light according to a signal from the control section 14. To irradiate the liquid crystal display element 16. In this embodiment, the multicolor light emitting device 17 is formed by green and red light emitting sources 17a and 17b.
For a and 17b, an LED or the like may be used.

As shown in FIG. 2, both the green and red light sources 17a and 17b irradiate the entire liquid crystal display element 16 from behind. Thus, the illuminated liquid crystal display element 16 emits green and red light emitting sources 17.
The light emission colors a and 17b are seen as synthesized colors.

Reference numeral 18 denotes a top plate, which is arranged above the heating coil 5 and on which a load 20 to be described later to be heated is placed. Reference numeral 19 denotes a main body of the induction heating cooker including all the components except the power supply 1 and the top plate 18.

Reference numeral 20 denotes a load placed on the top plate 18 above the heating coil 5 and heated.

The overall operation of the above configuration will be described.

An AC power supply 1 is supplied to a rectifier circuit 2. The rectifier circuit 2 converts the power supply 1 into a DC power supply and smoothes it with a smoothing capacitor 3. Then, this DC power is supplied to a resonance circuit 6 formed by the heating coil 5 and the resonance capacitor 4.

In this state, while grasping the signals of the primary current detecting element 11, the coil current detecting element 12, and the temperature detecting element 13, the control section 14 controls the input power according to the level of the heating power set by the operation section 15. To control
A signal is output to the drive unit 10 to operate the inverter circuit 9 via the drive unit 10.

The inverter circuit 9 generates a high-frequency resonance current in the resonance circuit 6 to heat the load 20 placed on the top plate 18 above the heating coil 5. At this time,
The control unit 14 controls the input power and the like according to the level of the heating power set by the operation unit 15, and outputs an appropriate heating power.

The control unit 14 outputs signals corresponding to the liquid crystal display element 16 and the multicolor light emitting device 17 when the heating power level is set and the heating operation is performed by the operation unit 15, respectively. The display according to the setting state, the heating state, and the like is performed, and at the same time, the multicolor light emitting device 17 emits a color corresponding to the display content of the liquid crystal display element 16, and the liquid crystal display element 16 is irradiated from behind.

At this time, the control unit 14 sends the multicolor light emitting device 17
The details of the signal to are described with reference to FIG. In the figure, (a), (b) and (c) show three different types of signals from the control unit 14 to the green and red light emitting sources 17a and 17b.

In the case of FIG. 5A, the green light source 17a
When the duty ratio of the signal to the red light emitting source 17b is low and the duty ratio of the signal to the red light source 17b is low, the strong green and the weak red are combined, and the liquid crystal display element 16 appears as a pale orange color close to green.

In the case of FIG. 9C, the green light source 17a
When the duty ratio of the signal to the red light emitting source 17b is low and the duty ratio of the signal to the red light source 17b is high, the weak green and the strong red are combined, and the liquid crystal display element 16 looks dark orange close to red.

In the case of FIG. 3B, the green light source 17a
When the duty ratio of the signal to the red light emitting source 17b is substantially the same as the duty ratio of the signal to the red light emitting source 17b, the liquid crystal display element 16 looks almost in the middle between the above (a) and (b).

Although not shown, the duty ratio of the signal to the green light source 17a is set to approximately 100%, and the red light source 17a is turned on.
Assuming that the duty ratio of the signal to b is substantially 0%, the synthesized color is substantially green. Conversely, the duty ratio of the signal to the green light source 17a is substantially 0%, and the color to the red light source 17b is substantially zero. Assuming that the signal energization rate is almost 100%, the synthesized color is almost red.

As described above, the control section 14 inputs a signal for controlling the duty ratio of each of the light emitting sources 17a and 17b forming the multicolor light emitting device 17 to the multicolor light emitting device 17 and changes the signal. Illuminates the liquid crystal display element 16 by changing the emission color of the multicolor light emitting device 17 by the
Can be varied in a wide range of colors, almost stepless.

As described above, the visible color of the liquid crystal display element 16 can be changed in a wide range and almost steplessly in many colors. Therefore, various states differ not only in the content of the liquid crystal display element 16 but also in the color. , So that it is very easy to recognize the difference between the states.

Further, the control unit 14 controls the multicolor light emitting device 17 according to the set level of the heating power set by the operation unit 15.
The liquid crystal display element 16 is irradiated by changing the emission color of the liquid crystal.

One specific embodiment will be described below.

When the set level of the heating power is low, FIG.
As shown in (a), the duty ratio of the signal to the green light source 17a is increased, and the duty ratio of the signal to the red light source 17b is reduced. Then, two colors, green and red, having different conduction ratios are synthesized, and the liquid crystal display element 16 looks pale orange close to green. When the set level of the heating power is high, FIG.
As shown in (2), the duty ratio of the signal to the green light source 17a is reduced, and the duty ratio of the signal to the red light source 17b is increased. Then, the liquid crystal display element 16 looks deep orange, close to red.

When the set levels of the heating power are multi-steps, the duty ratios of the signals to the green and red light emitting sources 17a and 17b are changed and combined, and the colors are set in accordance with the number of the set levels of the heating power. The liquid crystal display element 16 is irradiated with light. That is, the control unit 14 can change the emission color of the multicolor light emitter 17 to irradiate the liquid crystal display element 16 in accordance with the set level of the heating power set by the operation unit 15, and set the heating power to the set level. Differences are much easier to recognize than displayed as differences in brightness.

In the above example, the light emitting sources 17a and 17b are green and red, but other colors may be combined according to the specifications and conditions of the product. The light source 17 of the multicolor light emitter 17
By forming a and 17b in three colors of red, green and blue, and changing the duty ratio of each color, almost all colors can be synthesized.

The light emitting sources 17a and 17 of the multicolor light emitting device 17
When it is desired to emit a color having a different color tone from the case where b is composed of three colors of red, green and blue, the b is composed of two or more colors different from the above, and the light emitting sources 17a, 17b of the respective colors
It is also possible to adopt a configuration in which the duty ratio is changed.

Further, it is also possible to change the duty ratio of the signal to each of the plurality of light emitting sources 17a and 17b with time so that the color changes with time. For example, it is necessary to periodically change many luminescent colors, such as changing green → light orange → dark orange → red →..., Or to randomly change the luminescent color and its lighting time. It is possible without increasing.

This makes it possible to recognize a heating state, a feeling of heat, and the like at the time of heating with a visual color image in the same manner as a gas flame, and to easily recognize the feeling of heat, the setting state, the heating state, and the like. And a simple configuration does not take up much space.

In addition, since the color is changed according to the elapsed time from the start of heating, the timing of adjusting the heating power, the timing of feeding the ingredients, the timing of adding the seasoning, and the like become easy to understand when performing the heating and cooking.

[0062]

As described above, according to the induction heating cooker of the present invention, a multicolor light emitter formed by two or more light sources having different emission colors is provided. From the light source, and the liquid crystal display element emits light so that the color changes with time, and the irradiated liquid crystal display element emits light from each of the light emitting sources. The colors are configured so that they can be seen in a synthesized color.

As a result, the heating state, the feeling of heat and the like at the time of heating can be recognized by a visual color image in the same way as the gas flame, and the feeling of heat, the setting state, the heating state and the like can be more easily recognized. In addition, a simple configuration does not take up a large space.

In addition, since the color is changed according to the elapsed time from the start of heating, the timing of adjusting the heating power, the timing of feeding the ingredients, the timing of adding the seasoning, and the like become easy to understand when performing the heating and cooking.

[Brief description of the drawings]

FIG. 1 is a circuit block diagram showing one embodiment of the present invention.

FIG. 2 is a diagram showing details of a display portion of an embodiment of the present invention.

FIG. 3 is a diagram showing a signal waveform to a multicolor light emitting device according to one embodiment of the present invention.

FIG. 4 is a circuit block diagram of a conventional induction heating cooker.

FIG. 5 is a diagram showing a light emitting unit of a circuit diagram in one embodiment of a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Power supply 2 Rectifier circuit 4 Resonant capacitor 5 Heating coil 6 Resonant circuit 8 Switching element 9 Inverter circuit 14 Control part 15 Operation part 16 Liquid crystal display element 17 Multicolor light emitting device 17a, 17b Light emitting source 18 Top plate 20 Load

Claims (1)

[Claims] A rectifier circuit (2) for converting an AC power supply (1) to a DC power supply is provided, and the DC power supply is connected to a resonance circuit (6) formed by a heating coil (5) and a resonance capacitor (4). And a load (not shown) that is formed by a switching element (8) or the like, generates a high-frequency resonance current in the resonance circuit (6), and is mounted on a top plate (18) above the heating coil (5). 20) an inverter circuit (9) for heating, a control unit (14) for controlling the input electric power and the like, an operation unit (15) for setting the level of the heating electric power and the like are provided, and the control unit (14) In an induction heating cooker provided with a liquid crystal display element (16) that performs display in response to a signal of two or more light emitting sources (17
a) a multicolor light-emitting device (17) formed by (17b)
And the multicolor light emitting device (17) is provided with the control unit (14).
The liquid crystal display element (16) is illuminated by emitting light so that the color changes with time, and the irradiated liquid crystal display element (16) An induction heating cooker characterized in that the emission colors of the emission sources (17a) and (17b) are configured to be seen in a synthesized color.