JP4613684B2 - Electromagnetic cooker - Google Patents

Description

The present invention relates to an electromagnetic cooker with touch key over that provided in the plate.

  Conventionally, as this type of touch key, for example, one as shown in FIG. 9 has been proposed (for example, see Patent Document 1).

  FIG. 9 shows the configuration, in which an electrode portion 31 is provided on the back surface of the panel portion 30 of an electrical insulator, and a surface portion facing the electrode portion 31 of the panel portion 30 is touched with a finger 32. The oscillation unit 33 generates a high frequency voltage and applies the high frequency voltage to the electrode unit 31 via the contact 34. When a position facing the electrode portion 31 on the surface portion of the panel portion 30 is touched with the finger 32, the high frequency voltage is bypassed through the electrode portion 31, the panel portion 30, and the finger 32, and the voltage appearing at the electrode portion 31 is touched with the finger 32. It is lower than the voltage when not. The detection unit 35 rectifies and converts the input high-frequency voltage into a DC voltage, and obtains a high DC voltage when the electrode unit 31 is not touched and a reduced DC voltage when the electrode unit 31 is touched. Further, the detection unit 35 calculates the difference between the DC voltages, and determines that the touch has been made when the difference value is equal to or greater than a predetermined value.

  FIG. 10 shows the voltage detection operation of the detection unit 35. The voltage V1 is a DC voltage obtained when not touching, and a DC voltage V2 is obtained when the position where the electrode part 2 of the panel part 1 faces is touched at time t1, and the detection part 35 calculates V1-V2. An operation result ΔV is obtained. When this ΔV is greater than or equal to a predetermined value, it is determined that the touch has been made.

FIG. 11 shows an example in which this touch key is incorporated in an electromagnetic cooker. A metal casing 36 of the electromagnetic cooker is incorporated in the base 37. The contact 34 comes into contact with the auxiliary electrode part 31 a provided in the electrode part 31. The contact 34 is attached to a printed circuit board unit 38 on which the oscillation unit 33, the detection unit 35, and the like are mounted. Further, the contact 34 has a structure such as a partial bending, is made of a spring, and is pressed against the auxiliary electrode portion 31a. Then, as shown in FIG. 12, if the area of the electrode part 31 is large when viewed from the back surface of the panel part 30 and the area of the auxiliary electrode part 31a is set small, and touching the electrode part 31, a large voltage difference is obtained. Thus, a small voltage difference is obtained by touching the auxiliary electrode portion 31a, and it is determined that the touch is made only when the electrode portion 31 is touched. Thus, by providing a touch key in the panel part 30, it can operate | move, seeing a foodstuff.
Japanese Patent Laid-Open No. 2003-224459

  However, in the conventional configuration, when the distance d between the panel unit 30 and the metal housing 36 is changed, the detection sensitivity is changed. That is, when the distance d is small, the high-frequency voltage applied to the electrode unit 31 is also bypassed to the metal casing 36, and even if the panel unit 30 is touched with a finger, a voltage drop of a predetermined voltage cannot be obtained and the detection sensitivity is improved. descend. On the other hand, when the distance d is large, the detection sensitivity is increased, and there is a problem that even if a place outside the predetermined position of the panel unit 30 is touched, it is determined that the touch has been made.

The present invention is the one that solves the conventional problem, even if the distance between the plate and the metallic chasis is panel portion is changed, or a stable touch key over no fluctuation in detection sensitivity fluctuates It aims at providing the used electromagnetic cooker.

In order to solve the conventional problems, electromagnetic cooker with touch key over the present invention includes a metal housing which is set to the ground potential, Ri name from an electrically insulating material, and a display unit for placing the pan touch
A plate provided with a key, and a heating coil provided at a lower portion of the display unit for heating the pan, wherein the touch key includes a first electrode unit provided on a back surface of the plate , and the first electrode an electrode portion and the facing sides of the second electrode collector to have a portion electrode substrate to the surface portion, and a connecting portion for electrically connecting the first electrode portion and the second electrode portion, the second an oscillator for applying a voltage of a predetermined frequency to the electrode portion of, and a detecting section for detecting the output voltage of the second electrode portion, the electrode substrate portion, on the opposite surface and the second electrode portion it is obtained by a configuration having a third electrode portion connected to the metal housing.

As a result, the high-frequency voltage applied to the first or second electrode portion is affected only by the capacitance value constituted by the second electrode portion, the electrode substrate portion, and the third electrode portion. The capacitance value composed of the electrode part, the electrode substrate part, and the third electrode part is constant, and even if the distance between the plate and the metal casing changes or varies, the high-frequency voltage is not affected and is detected. The voltage is constant and stable with no variation in detection sensitivity.

Electromagnetic range using a touch key over the present invention, even if the distance changes between the plate and the metallic chasis, or even becomes stable without variations in the detection sensitivity varies.

The first invention includes a metal housing which is set to the ground potential, Ri name from electrically insulating material, a plate display unit and a touch key is provided for placing the pan, the provided at a lower portion of the display unit comprising a heating coil for heating a pan, wherein the touch key is used, the number and the first electrode portion provided on the rear surface of said plate, said second electrode portions on the surface of the side facing the first electrode portion and electrodes substrate portion to a connecting portion which connects the said first electrode portion and the second electrode portion electrically, an oscillator for applying a voltage of a predetermined frequency to the second electrode portions, and a detector for detecting an output voltage of the second electrode portion, the electrode substrate portion includes a third electrode portion connected to the metal housing to the opposite surface and the second electrode portion Thus, the high-frequency voltage applied to the first or second electrode portion is the same as that of the second electrode portion and the electrode base. Parts, will be influenced only constituted capacitance value by the third electrode portion, the second electrode portion and the electrode substrate portion, with the capacitance constituted by the third electrode part fixed, plate and metal Even if the distance to the housing changes or varies, the high-frequency voltage is not affected, and the detection voltage is constant and the detection sensitivity does not vary.

  In addition, by using an electromagnetic cooker using touch keys, it is possible to operate on the plate surface while watching the cooked food, thereby realizing a reliable operation.

  In the second invention, in particular, in the first invention, the area of the second electrode portion facing the third electrode portion across the electrode substrate portion is set larger than the area not facing the third electrode portion. Accordingly, the influence of the high frequency voltage applied to the second electrode portion from the metal casing can be reduced, and a stable touch key can be realized.

According to a third aspect of the invention, in particular, in the first or second aspect of the invention, the connection portion is made of an electrically conductive elastic body, so that the electrode substrate portion is pressed against the panel portion, and the first electrode portion and the second electrode portion are pressed. Thus, it is possible to realize a stable touch key that does not change in sensitivity even if the distance between the plate and the metal casing changes.

In the fourth invention, in particular, in any one of the first to third inventions, the connection portion is made of conductive rubber, thereby ensuring conduction between the first electrode portion and the second electrode portion, Even if the distance between the plate and the metal casing changes, it is possible to realize a stable touch key that does not change in sensitivity.

In the fifth invention, in particular, in any one of the first to third inventions, the connection portion is constituted by a metal spring, thereby ensuring conduction between the first electrode portion and the second electrode portion, Even if the distance between the plate and the metal casing changes, it is possible to realize a stable touch key that does not change in sensitivity.

A sixth invention is particularly, in any one invention of the first to fifth, with the bus Ne provided in a metal housing, the spring in the third is brought into contact with the electrode plate of the electrode substrate portion By adopting the pressing structure, the third electrode portion can be reliably set to the ground potential, and the electrode substrate portion can be pressed to the plate , and the sensitivity does not change even if the distance between the plate and the metal casing changes. A stable touch key can be realized.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
1 and 2 show a touch key according to Embodiment 1 of the present invention.

  As shown in the figure, the touch key in the present embodiment includes a panel portion 1 made of a flat electrical insulator such as glass, a first electrode portion 2 provided on the back surface of the panel portion 1, a first An electrode substrate portion 5 having a second electrode portion 3 on the opposite side of the electrode portion 2 and having a third electrode portion 4 on the opposite surface of the second electrode portion 3; A conductive connection part 6 that electrically connects the second electrode part 3, an oscillation part 7 that applies a voltage of a predetermined frequency to the second electrode part 3, and an output voltage of the second electrode part 3 The third electrode unit 4 is connected to the ground potential and held at the ground potential.

  Then, the high-frequency voltage generated by the oscillation unit 7 in the second electrode unit 3 is applied to the first electrode unit 2 through the connection unit 6. Here, when the surface portion of the panel portion 1 facing the first electrode portion 2 is touched with the finger 9, the high frequency voltage is bypassed through the first electrode portion 2, the panel portion 1, and the finger 9, The voltage appearing at the electrode unit 2 is lower than the voltage when the finger 9 does not touch. The detection unit 8 rectifies and converts the input high frequency voltage into a DC voltage. obtain. Further, the detection unit 8 calculates the difference between the DC voltages, and determines that the touch is made when the difference value is equal to or greater than a predetermined value (same as the background art).

  FIG. 2 shows a configuration example in which a metal casing 11 of an electromagnetic cooker having this touch key is incorporated in a base 12. The electrode substrate portion 5 has a pattern 14 connected to the second electrode portion 3, and a connector 15 is connected to the pattern 14. The connector 15 is connected via a lead wire 16 to an electronic circuit mounting substrate 10 on which the oscillation unit 7 and the detection unit 8 are mounted. Further, the third electrode portion 4 of the electrode substrate portion 5 is connected to the metal casing 11 set to the earth potential via a spring 13 provided on the metal casing 11 and set to the earth potential. . Therefore, the high-frequency voltage applied to the first electrode part 2 or the second electrode part 3 depends on the stray capacitance formed by the first electrode part 2 or the second electrode part 3 and the metal casing 11. It is not affected, and is affected only by the capacitance value constituted by the second electrode portion 3, the electrode substrate portion 5, and the third electrode portion 4. The capacitance value constituted by the second electrode portion 3, the electrode substrate portion 5, and the third electrode portion 4 is constant, and the high-frequency voltage does not change even if the distance d between the panel portion 1 and the metal casing 11 changes. Without being affected, the detection voltage is constant and the detection sensitivity is stable without fluctuation.

  By configuring the touch key in this way, the touch key can be mounted in a place where the distance between the panel unit 1 such as an electromagnetic cooker and the metal casing 11 is narrow. FIG. 3 shows a configuration example in which three touch keys are mounted on the electrode substrate unit 5.

The second electrode portions 3 a, 3 b, 3 c are connected to the connector 15 with a pattern 14. A third electrode portion 4 is provided at a position facing the second electrode portions 3a, 3b, and 3c across the electrode substrate portion 5. In order to reduce the influence of the stray capacitance with the metal casing 11, the area of the third electrode part 4 is set larger than the area of each of the second electrode parts 3a, 3b, 3c, and the high frequency The area of the second electrode portions 3a, 3b, and 3c is set to be small so that the current is grounded and the sensitivity is not lowered.

  As described above, in the present embodiment, the electrode substrate portion 5 having the second electrode portion 3 and the third electrode portion 4 is provided, and the third electrode portion 4 is grounded to operate stably and reliably. It is possible to provide a touch key that can be incorporated even in a narrow place. As described above, the larger third electrode portion 4 is less affected by the stray capacitance with the metal casing 11 and operates stably. It may be smaller than the area. At this time, the influence of the stray capacitance with the metal casing 11 appears, but the presence of the third electrode portion 4 can reduce the influence of the stray capacitance.

(Embodiment 2)
FIG. 4 shows a touch key according to Embodiment 2 of the present invention. The same elements as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  As shown in the figure, the second electrode portion 3 of the touch key in the present embodiment is not disposed directly above the third electrode portion 4 but is shifted from the third electrode portion 3 with the electrode substrate portion 5 interposed therebetween. The area S2 facing the portion 4 is set larger than the area S1 not facing the third electrode portion 4. Other configurations are the same as those of the first embodiment.

  As described above, in the present embodiment, in the relationship between the second electrode portion 3 and the third electrode portion 4, the high frequency voltage applied to the second electrode portion 3 is set by setting the area S2 to be larger than the area S1. Is less affected by the metal casing 11, and a stable touch key can be realized. That is, the influence of the stray capacitance with the metal casing 11 can be greatly reduced, the design margin of the second electrode unit 3, the third electrode unit 4, or the electrode substrate unit 5 is expanded, and a stable operation touch is achieved. A key can be provided.

(Embodiment 3)
Next, the touch key in Embodiment 3 of this invention is demonstrated.

  The connection portion 6 that electrically connects the first electrode portion 2 and the second electrode portion 3 in the first embodiment reliably supplies the high-frequency voltage applied to the second electrode portion 3 to the first electrode portion. It must be electrically conductive because it must be communicated to 2. However, since it is a high frequency voltage that is transmitted, even if it has a DC resistance, it only needs to have a low impedance with respect to the operating frequency.

  Therefore, the connecting portion 6 in the present embodiment is conductive and is made of an elastic body. Other configurations are the same as those of the first embodiment.

  As described above, in the present embodiment, the electrode substrate portion 5 is pressed against the panel portion 1 by the connecting portion 6 to ensure conduction between the first electrode portion 2 and the second electrode portion 3, and the panel portion 1 and the metal are made of metal. A stable touch key that does not change in sensitivity even when the distance to the housing 11 changes can be realized.

(Embodiment 4)
Next, a touch key according to Embodiment 4 of the present invention will be described.

The connection part 6 in this Embodiment is comprised with conductive rubber. Specifically, as shown in FIG. 5, the conductive rubber used for the connecting portion 6 is bonded to the second electrode portion 3 of the electrode substrate portion 5, and the portion that contacts the first electrode portion 2 at the other end is attached. When pressed, it is easy to bend, and for example, it is tapered and processed into a plurality of mountain shapes, so that the connection with the first electrode portion 2 is made more reliable by elasticity.

  Thus, in this Embodiment, the connection part 6 is comprised with conductive rubber, thereby ensuring the electrical connection between the first electrode part 2 and the second electrode part 3, and the panel part 1 and the metal are made of metal. A stable touch key that does not change in sensitivity even when the distance to the housing 11 changes can be realized.

(Embodiment 5)
Next, a touch key according to Embodiment 5 of the present invention will be described.

  The connection part 6 in this Embodiment is comprised with the metal springs 6a as shown in FIG. 6, FIG. Specifically, the four corners of the substrate portion of the metal spring 6 a are soldered 17 to the second electrode portion 3.

  Thus, in this Embodiment, the connection part 6 is comprised by the metal springs 6a, thereby ensuring the conduction between the first electrode part 2 and the second electrode part 3, and the panel part 1 and the metal A stable touch key that does not change in sensitivity even when the distance from the housing 11 changes can be realized. In particular, there is no problem even when a high temperature is applied when cooking on the surface of the panel unit 1, and a highly reliable touch key can be provided.

(Embodiment 6)
Next, a touch key according to Embodiment 6 of the present invention will be described.

  In the present embodiment, as shown in the first embodiment, a metal casing 11 and a spring 13 provided on the casing 11 are provided, and the spring 13 is brought into contact with the third electrode portion 4 to form an electrode substrate. The portion 5 is pressed against the panel portion 1. The spring 13 is directly raised from the metal casing 11, but naturally, the spring 13 may be formed by using other spring materials. Further, the spring 13 is made of the same member as that of the metal casing 11 and is brought into contact with the third electrode portion 4 so that the potential of the third electrode portion 4 is set to the ground potential. If the spring 13 is made of a non-conductive material, the third electrode portion 4 may be set to the ground potential by another wiring or the like.

  Thus, in this embodiment, by providing the spring 13, the third electrode portion 4 can be reliably set to the ground potential, and the electrode substrate portion 5 can be pressed against the panel portion 1. A stable touch key that does not change in sensitivity even when the distance from the housing 11 changes can be realized.

(Embodiment 7)
FIG. 8 shows an electromagnetic cooker using touch keys in Embodiment 7 of the present invention.

  In the present embodiment, touch keys 20 and 21 which are portions indicating the opposed positions of the first electrode unit 2 are provided on the plate 19 of the electromagnetic cooker 18, and the touch keys 20 and 21 are viewed while watching the food. It can be operated. The plate 19 has display units 22 and 23 for placing pans and the like on the right and left sides. A heating coil is provided below the display units 22 and 23, and the pans on the display units 22 and 23 are generated by a high-frequency magnetic field generated from the heating coil. Inductive current is passed through and heated. Furthermore, a heater 24 that can directly heat a pan or the like is provided on the plate 19.

The electromagnetic cooker 18 is used by being incorporated in the cooking table 25, and includes a roaster 26, a display unit 27, a switch 28, and the like on the front surface of the electromagnetic cooker 18. Further, the touch keys 20 and 21 are provided on the front face of the electromagnetic cooker 18 for ease of operation.

  Thus, in this embodiment, by using the electromagnetic cooker that uses the touch key in each of the first to sixth embodiments, electromagnetic cooking with a touch key that can be operated on the surface of the panel unit while watching the cooked food is possible. Can be realized. In addition, since a touch key is small and can be comprised thinly, it is very useful for electromagnetic cookers.

  As described above, the touch key according to the present invention and the electromagnetic cooker using the touch key are stable with no change in detection sensitivity even when the distance between the panel unit and the metal casing changes or varies. Will be. In particular, the touch key can be applied not only to an electromagnetic cooker but also to home appliances such as a microwave oven or various devices.

Block diagram of touch keys in the first to fourth and sixth embodiments of the present invention Sectional view of the touch key assembled in the housing Plan view showing a configuration example of the touch key The top view which shows the electrode substrate part of the touch key in Embodiment 2 of this invention The perspective view which shows the connection part of the touch key in Embodiment 4 of this invention. Sectional drawing which shows the connection part of the touch key in Embodiment 5 of this invention. Top view of the touch key connection The perspective view which shows the electromagnetic cooker in Embodiment 7 of this invention. Block diagram of a conventional touch key Detection voltage waveform diagram of the touch key Sectional view of the touch key assembled in the housing Plan view of electrode part of the touch key

DESCRIPTION OF SYMBOLS 1 Panel part 2 1st electrode part 3, 3a, 3b, 3c 2nd electrode part 4 3rd electrode part 5 Electrode board | substrate part 6 Connection part 7 Oscillation part 8 Detection part 11 Metal enclosure 13 Spring 18 Electromagnetic cooker

Claims (6)

A metal housing which is set to the ground potential, Ri name from electrically insulating material, a plate display unit and a touch key for placing the pan provided, heating coil for heating the pot is provided at a lower portion of the display unit When, wherein the touch key, a first electrode portion provided on the rear surface of the plate, and the first electrode portion and facing the surface on the side second electrodes substrate portion to have the electrode portion A connection part for electrically connecting the first electrode part and the second electrode part, an oscillation part for applying a voltage of a predetermined frequency to the second electrode part, and the second electrode part and a detecting section for detecting the output voltage, the electrode substrate portion, an electromagnetic cooker having a third electrode portion connected to the metal housing to the opposite surface and the second electrode portion. 2. The electromagnetic cooker according to claim 1, wherein the second electrode portion has an area facing the third electrode portion across the electrode substrate portion set larger than an area not facing the third electrode portion. The electromagnetic cooker according to claim 1 or 2, wherein the connecting portion is made of an electrically conductive elastic body. The electromagnetic cooker according to any one of claims 1 to 3, wherein the connecting portion is made of conductive rubber. The electromagnetic cooker according to any one of claims 1 to 3, wherein the connecting portion is formed of a metal spring. Comprising a bar Ne provided in a metal chassis, an electromagnetic cooker according to any one of claims 1 to 5, the spring and the third electrode substrate portion in contact with the electrode portion is configured to press against the plate.

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