JP2007227402A - Induction heating cooker - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a touch switch from being hidden by a heating object mounted on a top plate. <P>SOLUTION: A conductive thin film made of a metal material is formed on an underside of a top plate 7. A touch operation part 35 for adjusting an output of an induction heating coil is fitted at right and left end parts of the top plate 7. The touch operation part 35 is equipped with a capacitance type touch switch 37 of having a touch detection electrode 40 structuring from a part of the conductive thin film. The touch detection electrode 40 is connected to a touch detection circuit through a connection pattern 44 film-formed on the underside of the top plate 7, and a conductive electrode 43. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an induction heating cooker having a top plate provided on an upper portion of induction heating means and on which an object to be heated is placed.

  For example, an induction heating cooker incorporated in a kitchen kitchen table includes a plurality of heating means such as an induction heating coil and a coil heater arranged in a main body case having an open upper surface, and a top arranged on the upper part of the main body case. It is configured with a plate. An operation unit is provided on the front surface of the induction heating cooker, and an operator operates the operation unit to adjust the output of the heating means.

However, the induction heating coil cannot directly see the change in its output. Therefore, when the output is adjusted by operating the operation unit, the posture is changed and the heating state of the object to be heated on the top plate is checked to check the change of the output, so that the operability is poor.
On the other hand, there exists an induction heating cooking appliance which provided the operation part on the upper surface of the top plate. In the above configuration, since the operation unit and the position of the object to be heated placed on the top plate are close to each other, the operation unit can be operated while viewing the heating state of the object to be heated.

In this case, since there is poor cleaning workability if there are protrusions such as operation buttons on the surface of the top plate, it is considered that the operation unit is composed of a capacitive touch switch. The touch switch outputs a change in capacitance caused by a user's finger touching the surface of the top plate as an operation signal, and includes a touch detection electrode.
Japanese Patent Laid-Open No. 10-214677

  The problem to be solved is that the operation unit may be hidden by the heated object placed on the top plate.

The present invention includes a case that has a box-like accommodation portion that is fitted in an opening formed on the top plate of a cooking table and accommodates an induction heating coil, and a flange that is placed on the top plate. The top plate is disposed on the upper surface of the case so as to close the top plate. The top plate on which the object to be heated is placed, the operation unit for detecting the contact of the user, and the housing part of the case are provided. A circuit board including a touch detection circuit, and the operation unit is provided corresponding to the contact portion provided on an end portion of an upper surface of the top plate and on the lower side of the top plate. A touch detection electrode, and a conductive electrode that is located apart from the touch detection electrode, is connected to the touch detection electrode by a connection pattern, and electrically connects the touch detection electrode and the touch detection circuit. Having And features.
In this case, a leaf spring that electrically connects the touch detection circuit and the conductive electrode may be provided.

  According to the present invention, even if the contact portion of the operation portion is provided on the top plate, the above configuration prevents the contact portion of the operation portion from being concealed by the heated object placed on the top plate. Can be.

Hereinafter, several embodiments in which the present invention is applied to an induction heating cooker incorporated in a system kitchen will be described with reference to the drawings. These examples do not limit the configuration of the present invention.
Example 1
1 to 5 show a first embodiment of the present invention. FIG.1 and FIG.2 shows the whole structure of the heating cooker based on a present Example. In these FIG.1 and FIG.2, the heating cooker main body 1 is located in the lower part of the upper unit 1a and upper unit 1a which are engage | inserted from the upper part with respect to the cooking table 2, and is inserted with respect to the said cooking table 2 from the front. It is comprised from the lower unit 1b.

The upper unit 1a includes a case 6 (both see FIG. 3) that accommodates the induction heating coils 3 and 4 and the radiant heater 5 as heating means, and a top plate 7 that closes the upper surface opening of the case 6. Has been. The top plate 7 is disposed on the case 6 while being supported by the outer frame 7a.
In the front part of the top surface of the top plate 7, induction heating parts 8 and 9 are provided side by side corresponding to the induction heating coils 3 and 4. In the center of the rear portion of the top plate 7, a heater heating unit 10 is provided corresponding to the radiant heater 5. A pan (not shown) that is an object to be heated is placed on the heating units 8 to 10. On the upper surface of the top plate 7, circular frame portions 8a to 10a for defining regions of the heating portions 8 to 10 and various frame portions 60 having design properties are printed.

The induction heating cooker according to the present embodiment is called a “wide top plate” type in which the width dimension of the top plate 7 is larger than the conventional one, and a large pan such as a wok is used for the heating units 8 and 9. Even if the pan is placed, the pan does not protrude from the top plate 7.
Coil output display units 11 and 12 (corresponding to light emitting display units) for displaying the output states of the induction heating coils 3 and 4 are provided in front of the induction heating units 8 and 9 in the top plate 7. 8a and 9a are provided. The coil output display units 11 and 12 include a plurality of light emitting elements, for example, light emitting diodes (hereinafter referred to as LEDs) 22. And the number showing the magnitude | size of the output of the induction heating coils 3 and 4 and the number showing the temperature of the oil at the time of tempura cooking are printed in the part corresponding to said LED22 among the upper surfaces of the top plate 7. FIG.

  Further, a heater output display unit 13 for displaying the output state of the radiant heater 5 is provided at the center of the front portion of the top plate 7. The heater output display unit 13 includes a plurality of light emitting elements, for example, light emitting diodes (hereinafter referred to as LEDs) 26. A frame portion 13 a that determines the arrangement area of the LEDs 26 is printed on the top surface of the top plate 7.

Further, a caution display unit 14 for displaying caution points for operation and the like is provided at the right rear portion of the top plate 7. The caution display unit 14 includes a character 14a printed on the lower surface of the top plate 7, a frame 14b surrounding the character 14a, and the like.
In addition, touch operation portions 35 and 36 for operating the induction heating coils 3 and 4 are provided on both left and right ends of the front portion of the top plate 7, respectively. Each of the touch operation units 35 and 36 includes four touch switches 37 to 40 for instructing to drive and stop the induction heating coils 3 and 4 and adjusting the output. The detailed configuration of the touch operation units 35 and 36 will be described later.

  The top plate 7 is formed by forming a light-transmitting conductive thin film 15 made of a metal material such as titanium on the lower surface of a heat-resistant transparent glass plate by a sputtering method. The thickness of the conductive thin film 15 is set to several hundreds of nanometers, so that the top plate 7 allows the wavelength near red to be transmitted better than other visible light. With the above configuration, the top plate 7 is observed as a metallic color tone.

  The thin film 15 is formed on substantially the entire lower surface of the top plate 7 except for the lower surface of the heater heating unit 10. A heat resistant coating film 16 is provided on the lower surface of the heater heating unit 10 in the top plate 7. The coating film 16 has a color or tone similar to that of the conductive thin film 15. The coating film 16 is applied to the lower surface of the top plate 7 so that the peripheral edge thereof is wrapped with the thin film 15. The characters 14a and the frame 14b of the caution display section 14 are printed on the lower surface of the top plate 7 before the conductive thin film 15 is formed.

  On the other hand, as shown in FIG. 3, the case 6 includes a thin rectangular box-shaped storage portion 6 a that stores the induction heating coils 3 and 4 and the radiant heater 5, and a flange 6 b that protrudes to the left and right of the upper portion. . The accommodating portion 6a is fitted into the cooking table 2 through a rectangular opening (not shown) formed in the top plate 2a of the cooking table 2, and the flange 6b is placed on the top plate 2a. .

The induction heating coils 3 and 4 and the radiant heater 5 are all disposed below the induction heating units 8 and 9 and the heater heating unit 10 in the housing 6a. The radial heater 5 generates heat when a direct current is applied to the nichrome wire. A cooling fan device 18 is disposed on the right side of the rear portion in the housing portion 6a.
In the vicinity of the induction heating coils 3 and 4, a magnetic shield ring 19a is disposed. A temperature sensor 19b is disposed at the center of the induction heating coils 3 and 4. In addition, an inverter 19 c that supplies a high-frequency current to the heating coils 3 and 4 is provided in the case 6 below the induction heating coil 4. An induction heating assembly 19 (corresponding to induction heating means) is constituted by the induction heating coils 3 and 4, the inverter 49 (see FIG. 5), the magnetic shield 19a, the temperature sensor 19b and the like.

  The induction heating assembly 19 is screwed into the case 6 so that the induction heating coils 3 and 4 are positioned below the induction heating portions 8 and 9 with the induction heating coils 3 and 4 being close to the lower surface of the top plate 7 respectively. A substrate mounting member 20 is screwed to the first half of the outer peripheral portion of the induction heating assembly 19. A printed board 21 is attached to the board attaching member 20. A plurality of the LEDs 22 are mounted on the printed circuit board 21. The board mounting member 20, the printed board 21, and the LED 22 constitute the coil output display units 11 and 12.

The radial heater 5 is disposed at the bottom of a base 23 that is a circular heat insulating container that is fixed in the case 6 and has an open top surface. The base 23 is screwed to the bottom of the case 6 via a support frame 24. The upper end surface of the base 23 is in contact with a portion of the lower surface of the top plate 7 where the thin film 15 and the coating film 16 wrap.
A printed circuit board 25 is disposed in the center of the front part in the case 6. A plurality of LEDs 26 are mounted on the printed circuit board 25. The printed circuit board 25 and the LED 26 constitute the heater output display unit 13. The LEDs 22 and 26 are both configured to emit red light having a wavelength of about 600 to 650 nm. As a result, part (approximately 10%) of the light emitted from the LEDs 22 and 26 passes through the top plate 7 on which the conductive thin film 15 is formed, and is visible from the top of the top plate 7. Yes.

  As shown in FIG. 2, the lower unit 1 b includes a roaster 28 provided on the left side of the cabinet 27 and an operation panel 29 provided on the right side of the front door 28 a of the roaster 28. Yes. The roaster 28 uses a sheathed heater (not shown) as a heat source. The operation panel 29 is provided with dials 31 to 34 for turning on and off the power switch 30, the induction heating coils 3 and 4, the radiant heater 5, and the sheath heater of the roaster 28, and adjusting the output. ing. Although the detailed description and illustration are omitted, the dials 31 to 34 are all connected to a switch mechanism having a rotary rotary encoder and a push-push type switch.

  Next, the configuration of the touch operation units 35 and 36 will be described in detail. Each of the touch operation units 35 and 36 includes four touch switches 37 and a touch detection circuit 38 (see FIG. 5) that outputs a detection signal corresponding to the touch operation of the touch switch 37. Yes. The touch detection circuits 38 of the touch operation units 35 and 36 are mounted on circuit boards 39 disposed on the left and right sides of the front part in the accommodating unit 6a. Since the configurations of the touch operation units 35 and 36 are substantially the same, the configuration of the left touch operation unit 35 will be mainly described here.

  FIG. 4 is an exploded perspective view showing an enlarged peripheral portion of the touch operation unit 35. As shown in FIG. 4, the touch switch 37 includes a contact portion 40 provided on the top surface of the top plate 7, and a touch detection electrode 41 provided on the bottom surface of the top plate 7 corresponding to the contact portion 40. And a conductive electrode 43 connected to the touch detection circuit 38 via a leaf spring 42, and a connection pattern 44 connecting the touch detection electrode 41 and the conductive electrode 43.

The touch detection electrode 41, the conductive electrode 43, and the connection pattern 44 are all formed by depositing the same metal material such as titanium as the conductive thin film 15 on the lower surface of the top plate 7 by sputtering.
In this case, the touch detection electrode 41, the connection pattern 44, the conductive electrode 43, and the conductive thin film 15 of each touch switch 37 are formed on the lower surface of the top plate 7, the portion where the coating film 16 is formed, the touch detection electrode 41, and the connection pattern. 44. After the peripheral portion of the conductive electrode 43 is masked, a metal material is formed by a sputtering method at the same time.

  As a result, an exposed portion where the surface of the top plate 7 is exposed is formed between the touch detection electrode 41, the connection pattern 44, and the conductive electrode 43 of each touch switch 37 and between these and the conductive thin film 15. The exposed portion 45 is provided in order to electrically separate the touch detection electrode 41, the connection pattern 44, and the conductive electrode 43 of each touch switch 37 from each other and the conductive thin film 15.

  The contact portion 40 is configured by printing a conductive paint on the upper surface of the top plate 7. Characters and symbols indicating the function of the touch switch 37 are printed on the surface of each contact portion 40. Accordingly, the contact portion 40 determines an area in which the user contacts the touch switch 37 and also functions as a conductive auxiliary electrode that equivalently forms a capacitor with the touch detection electrode 41.

A portion of the top surface of the top plate 7 corresponding to the conductive electrode 43, the connection pattern 44, and the exposed portion 45 is provided with a coating 46 for covering them.
FIG. 5 is a diagram showing a schematic electrical configuration relating to one (left side) induction heating coil 3 of the induction heating cooker of the present embodiment. In FIG. 5, an inverter control circuit 48 and a touch detection circuit 38 are connected to the microcomputer 47. The inverter control circuit 48 controls an inverter 49 that supplies a high-frequency current to the induction heating coil 3.

  The touch detection circuit 38 includes four circuit units 51 connected in parallel. Each of the four circuit units 51 corresponds to four touch switches 37, and includes a capacitor 53, a diode 54, and an analog switch 55 connected in series to an output terminal of an oscillation circuit 52 that outputs an oscillation signal having a predetermined frequency. Has been. The touch detection electrode 41 is connected between the capacitor 53 and the diode 54, and the diode 54 and the analog switch 55 are grounded via a resistor 56 and a charge capacitor 57. The output terminal of the analog switch 55 is connected to the A / D input port of the microcomputer 47. The control terminal of the analog switch 55 is controlled by the digit output of the output port of the microcomputer 47.

The output current of the oscillation circuit 52 charges the charge capacitor 57 via the capacitor 53 and the diode 54. The voltage of the charge capacitor 57 is applied to the A / D input port of the microcomputer 47 when the control signal applied to the control terminal of the analog switch 55 is “HI”.
A circuit 51 a shown in FIG. 5 is a circuit including a diode 54, an analog switch 55, a resistor 56, and a charge capacitor 57. The microcomputer 47 is connected to the operation panel 29 and the coil output display unit 11.

  In the above configuration, when the user touches the contact portion 40 on the upper surface of the top plate 7, a capacitor is equivalently formed between the touch detection electrode 41 and the contact portion 40, and the output of the oscillation circuit 52 passes through the human body. Therefore, the voltage of the charge capacitor 57 decreases. When the decrease in the voltage of the charge capacitor 57 is detected by the microcomputer 47, the microcomputer 47 detects that the touch switch 37 has been operated. Thereby, the output of the corresponding induction heating coils 3 and 4 is turned on / off or changed.

As described above, in the present embodiment, since the touch operation portions 35 and 36 of the induction heating coils 3 and 4 are provided on the top plate 7, the induction heating coils 3 and 4 of the induction heating coils 3 and 4 are observed while observing the heating state of the heated object on the top plate 7. The output can be adjusted, improving operability and workability.
In addition, since the conductive thin film 15 and the touch detection electrode 41 are made of the same material, both can be simultaneously formed on the surface of the top plate 7. For this reason, the touch detection electrode 41 can be configured easily and inexpensively. In addition, since the conductive thin film 15 can obtain various colors and tones depending on the thickness dimension and material thereof, the color of the top plate 7 can be diversified.

  In this embodiment, the touch detection electrode 41 is provided on the lower surface of the top plate 7. For this reason, the touch detection electrode 41 and the touch detection circuit 38 can be easily connected. In addition, in this embodiment, a wide top plate is used, and touch operation portions 35 and 36 are provided on the left and right ends of the top plate 7. Therefore, there is no possibility that the touch operation parts 35 and 36 are hidden by the heated object placed on the top plate 7.

  In this case, since the touch detection electrode 41 and the touch detection circuit 38 are separated from each other, the connection pattern 44 and the conductive electrode 43 for connecting the touch detection electrode 41 and the touch detection circuit 38 are necessary. However, like the touch detection electrode 41, the connection pattern 44 and the conductive electrode 43 can also be configured in the same process using the same material as the conductive thin film 15. Therefore, an increase in the number of manufacturing steps and an increase in manufacturing cost due to the provision of the connection pattern 44 and the conductive electrode 43 can be suppressed.

In this embodiment, the contact part 40 of the touch switch 37 is configured to function as an auxiliary electrode of the touch detection electrode 41. Therefore, the capacitance between the operator's finger and the touch detection electrode 41 can be made constant regardless of the contact state of the contact portion 40 by the operator, and the detection characteristics of the touch switch 37 are stabilized.
Further, in the present embodiment, the conductive thin film 15 is formed on substantially the entire area of the lower surface of the top plate 7 excluding the lower surface of the heater heating unit 10, and the coating film 16 is applied to the lower surface of the heater heating unit 10. did. In addition, a coating 46 is applied to portions of the upper surface of the top plate 7 corresponding to the touch operation portions 35 and 36. For this reason, the state in the accommodating part 6a cannot be seen from the top plate 7, and the appearance can be improved.

(Example 2)
6 and 7 show a second embodiment of the present invention, and differences from the first embodiment will be described. The same parts as those in the first embodiment are denoted by the same reference numerals.
In the present embodiment, an LED 61 as a light emitting light source is disposed below the contact portion 40 in the accommodating portion 6a, and a transmission portion 62 that transmits light emitted from the LED 61 is provided in the contact portion 40. The transmissive part 62 is formed by not printing conductive paint on the part, and has a shape of characters or symbols (for example, “ON”, “OFF”, or arrow) indicating the function of the touch switch 37. . Therefore, in the present embodiment, the contact portion 40 functions as a touch switch display thin film and a conductive auxiliary electrode.

  In order to arrange the LED 61 below the contact portion 40, the contact portion 40 is arranged at a position slightly closer to the center than the left and right end portions of the top plate 7 in this embodiment. That is, the contact part 40 is arrange | positioned in the site | part in which the accommodating part 6a is located in the lower part of the top plate 7 instead of the flange 6b of the case 6. For this reason, the touch detection electrode 41 provided in the portion corresponding to the contact portion 40 is directly connected to the circuit board 39 (touch detection circuit 38) via the leaf spring 42.

The LED 61 is mounted on the circuit board 39. A light shielding portion 63 extending from the circuit board 39 to the vicinity of the lower surface of the top plate 7 is provided around each LED 61. Each LED 61 is configured to emit green light having a wavelength different from that of the LEDs 22 and 26, for example, about 500 to 550 nm. Therefore, it hardly penetrates the top plate 7.
With the above configuration, the light of the LED 61 can be seen through the transmission part 62 when viewed from above the top plate 7. Therefore, the user can clearly recognize the position of the contact portion 40.

(Example 3)
FIG. 8 shows a third embodiment of the present invention, and different points from the second embodiment will be described. In this embodiment, the touch operation unit 35 is provided with, for example, a cooking time setting switch 71 having a time setting function, and a clock display unit 72 is provided at the rear of the switch operation unit 35. Although not shown, the touch operation unit 36 has the same configuration. In this embodiment, the top plate 7 is not a wide top plate, but has a width that is substantially the same as that of the accommodating portion 6a.

The cooking time setting switch 71 includes a contact portion 40, a touch detection electrode (not shown), an LED (not shown), and the like, like the touch switch 37 shown in the second embodiment. . The contact portion 40 is provided with a transmission portion 62 that transmits the light of the LED.
The timepiece display unit 72 is composed of a plurality of LEDs 74 (corresponding to a timepiece light emitting element) functioning as a 7-segment numeral display mounted on a circuit board 73 in the housing portion 6a. Each of the LEDs 74 emits red light having a wavelength of about 600 to 650 nm, and is visible from the top plate 7.

  According to such a configuration, the cooking time setting switch 71 and the clock display unit 72 are close to each other, so that the operability of the setting switch 71 is improved. Further, since the LED 74 is disposed in the housing portion 6a, the provision of the clock display portion 72 does not cause unevenness on the surface of the top plate 7, and does not hinder the cleaning operation.

The present invention is not limited to the above-described embodiments, and for example, the following modifications are possible.
You may comprise a contact part using the coating material which does not have electroconductivity. In this case, since no capacitor is formed with the touch detection electrode, the capacitance between the touch detection electrode is not constant depending on the contact state of the operator's finger with the contact portion, and the detection characteristics become unstable. However, the contact portion can be clarified.
In the second and third embodiments, the transmissive portion is provided in the contact portion. However, when the contact portion itself has optical transparency, the transmissive portion may not be provided. In this case, a light emitting light source disposed below the contact portion employs a light source that emits light having a wavelength that can be transmitted through the contact portion.

In the second and third embodiments, the contact portion may be omitted. That is, even if there is no contact portion, the position of the touch switch can be defined by the light emitted from the LED and transmitted through the touch detection electrode.
The top plate may be configured by forming a light-transmitting conductive thin film on a colored glass plate having specific light transmission characteristics.
The conductive thin film may be formed on the upper surface of the glass plate.

  The material of the conductive thin film is not limited to titanium, and metals such as gold, copper, and aluminum, and metal oxides such as TiO2, SnO2, and InO2 can be used. That is, it is preferable to select a film material according to the color and tone of the top plate and the emission wavelength region of the LED constituting the display unit. Further, the thickness dimension of the conductive thin film can be set to about several tens to several hundreds of microns according to the light wavelength region of the light emitting element to be transmitted. Furthermore, as a method for forming the conductive thin film, a sputtering method, a physical manufacturing method such as a vacuum deposition method, or a chemical manufacturing method such as a spray method or a dip method can be used.

  The present invention can also be applied to a configuration including only a dielectric heating coil. Further, the present invention is not limited to the induction heating cooker incorporated in the cooking table, but can also be applied to an induction heating cooking device used by being placed on a cooking table or the like.

The top view which shows the whole structure of the induction heating cooking appliance which shows 1st Example of this invention. Front view of induction heating cooker Top view of induction cooker with top plate removed The exploded perspective view which expands and shows the touch operation part periphery Diagram showing electrical configuration The top view of a touch operation part periphery which shows the 2nd Example of the present invention. Longitudinal sectional view along line XX in FIG. The top view of the periphery of a timer display unit, showing a third embodiment of the present invention

Explanation of symbols

  In the figure, 1 is a heating cooker body, 2 is a cooking table, 2a is a top plate, 3 and 4 are induction heating coils, 6 is a case, 6a is a housing portion, 6b flange, 7 is a top plate, and 11 and 12 are coils. Output display section (light emitting display section), 15 is a conductive thin film, 19 is induction heating assembly (induction heating means), 22 and 26 are LEDs (light emitting elements), 35 and 36 are touch operation sections, 37 is a touch switch, 38 is a touch detection circuit, 40 is a contact portion (thin film for touch switch display, conductive auxiliary electrode), 41 is a touch detection electrode, 43 is a conductive electrode, 44 is a connection pattern, 61 is an LED (light emitting source), and 62 is transmissive , 71 is a cooking time setting switch, 72 is a clock display unit, and 74 is an LED (light-emitting element for clock).

Claims (2)

A case that is fitted in an opening formed on the top plate of the countertop and has a box-shaped housing portion that houses the induction heating coil and a flange placed on the top plate;
A top plate is disposed on the case so as to close the upper surface opening of the case, and a heated plate is placed thereon;
An operation unit for detecting a user's contact;
A circuit board provided in the housing portion of the case and provided with a touch detection circuit;
The operation unit is
A contact portion provided at an end of the top surface of the top plate;
A touch detection electrode provided on the lower side of the top plate corresponding to the contact portion;
It is located away from the touch detection electrode, is connected to the touch detection electrode by a connection pattern, and has a conductive electrode for electrically connecting the touch detection electrode and the touch detection circuit. Induction heating cooker.   The induction heating cooker according to claim 1, further comprising a leaf spring for electrically connecting the touch detection circuit and the conductive electrode.

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