JP2008192336A - Capacitive touch switch device - Google Patents

Abstract

[PROBLEMS] To prevent a switch operation from becoming unstable even in a touch switch device adopting a capacitance method as an input method, even when a derivative panel, which is an operation panel for performing ON / OFF switch operation with a finger, can be removed. .
A capacitive touch switch device comprising a control board 23 provided with a CPU and an operation panel unit connected via a connector connection terminal 22, and a switch electrode unit for performing a predetermined switch operation 15 and a dielectric panel 21 touched by a finger to perform a switch operation, an elastic conductive member 19 is interposed between the switch electrode portion 15 and the dielectric panel 21 to It is characterized by a structure in which an air layer that affects the change in electric capacity is not possible.
[Selection] Figure 8

Description

  The present invention relates to a capacitive touch switch device that employs a capacitive method as an input method.

The conventional capacitive touch switch device shown in FIG. 1 includes an operation panel 1 and a control board 2. The operation panel 1 is connected to the switch electrode 3 and the connector connection terminal 4 necessary for the operation of the switch on and off (for example, if the switch is used for cooking utensils, ignition and fire extinguishing, on and off). An electrode sheet 7 in which the pattern 5 and the GND pattern 6 are printed with a silver paste on a pet film or the like is pasted on a dielectric 8 that performs a switch operation such as resin or glass shown in the cross-sectional view of FIG. The electrode sheet 7 is connected to a connector connection terminal 4 provided on the control board 2 shown in FIG.
When the finger 10 that is a conductive member touches the portion corresponding to the switch electrode 3 of the derivative 8 that performs the switch operation shown in FIG. 2, the dielectric 8 that performs the switch operation is sandwiched between the switch electrode 3 and the finger 10 that is the conductive member. A parallel plate capacitor is formed and the capacitance increases. On the other hand, when the finger 10 as the conductive member is separated from the dielectric 8 that performs the switching operation, the dielectric 8 that performs the switching operation is formed as a parallel plate capacitor sandwiched between the switch electrode 3 and the finger 10 as the conductive member. The capacitance decreases. The control board 2 shown in FIG. 1 converts an increase / decrease in capacitance into a voltage by a C / V (capacitance is voltage) conversion circuit 11, and an analog / digital converter (CPU) 12 provided in an arithmetic processing unit (CPU) 12. ADC) is replaced with digital data, and the capacitance of the electrostatic capacity stored in the arithmetic processing unit (CPU) 12 is changed by a control program that determines the operation of the arithmetic processing unit stored in the arithmetic processing unit (CPU) 12. The general operating principle of the capacitive touch switch device is to determine the ON / OFF state of the switch by comparing the threshold values.

As shown in FIG. 3, the dielectric 8 that performs the switching operation and the electrode sheet 7 (the PET film on which the switch electrode, the GND pattern, and the wiring pattern are printed) are not attached with the double-sided tape or the adhesive. In the case where a gap is formed by overlappingly installing, the amount of change (increase) in capacitance becomes small when the dielectric 8 that performs a switching operation by the air layer 13 is touched with the finger 10 that is a conductive member. . Further, as shown in FIG. 4, when the dielectric 8 that performs the switching operation is deformed such as distortion or warping, if there is a portion that is not in close contact with the switch electrode 3, the derivative 8 that performs the switching operation by the air layer 13. The amount of change (increase) in capacitance when touching with the finger 10 becomes small, and a stable signal cannot be obtained. Therefore, the dielectric 8 and the electrode sheet 7 that perform the switch operation are pasted with the double-sided tape or the adhesive 9 so as not to generate the air layer 13.
Japanese Patent No. 2887336

However, in the case of a cooking utensil such as a cooking heater as shown in FIG. 5, the dielectric panel that performs the switch operation is soiled depending on the frequency of use. It is necessary to remove the dielectric panel for cleaning to remove dirt, but the dielectric panel that performs the switch operation and the switch electrode part on the electrode sheet are made of double-sided tape or adhesive so as not to generate an air layer. Pasting. For this reason, when removing the dielectric panel, in order to remove the electrode sheet from the connector electrically connected to the control board, the cooking heater main body must be turned upside down. It was bad.
Therefore, when the structure in which the panel (dielectric) and the electrode sheet are removable, the structure is such that the panel (dielectric) and the electrode sheet are simply overlapped, so that an air layer is formed between the panel (dielectric) and the electrode sheet. I can do it.
If an air layer is formed between the panel (dielectric) and the electrode sheet, the electrostatic capacity becomes unstable as described above, and a stable signal cannot be obtained along with this, so that the switch operation becomes unstable. There was a problem.

  A capacitive touch switch device comprising a control board provided with a CPU and an operation panel unit connected via a connector connection terminal, and performs a switch operation with a switch electrode unit that performs a predetermined switch operation Therefore, a capacitive touch switch device is proposed in which an elastic conductive member is interposed between the switch electrode portion and the dielectric panel in the operation panel portion including a dielectric panel touched by a finger. is there.

  Since the electrode sheet and the conductive member and the dielectric that performs the switch operation need not be attached with a double-sided tape or an adhesive, and can be installed simply by overlapping, the operation panel can be easily attached and detached. In addition, the capacitance is stable, a stable signal can be obtained, and the switch operation is stabilized.

  The details of the present invention will be described with reference to the drawings. FIG. 6 is a configuration diagram of an operation panel unit of the capacitive touch switch device, and FIGS. 7 to 9 are sectional views of the capacitive touch switch device. The electrode sheet 15 is affixed to a dielectric member 16 such as a resin with a double-sided tape or an adhesive 17 so as not to affect the change in capacitance. An elastic conductive member 19 such as conductive rubber is attached to the switch electrode 18 portion of the electrode sheet 15 with a double-sided tape or an adhesive 20. The switch electrode 18 is a part that performs an on / off operation as a switch. The portion of the switch electrode 18 corresponds to a portion set for on / off switch operation such as start and stop by the function of each model, and corresponds to the switch electrode 18 of the dielectric 21 that performs the switch operation. Further, the value of the change in capacitance when the finger 24 as the conductive member is touched is compared with the threshold value of the change in capacitance stored in the arithmetic processing unit (CPU). , Off.

Compared to the conventional method in which the electrode sheet is directly attached to the dielectric that performs the switch operation with a double-sided tape or an adhesive, the thickness of the elastic conductive member 19 is equivalent to that of the dielectric 21 that performs the switch operation. The distance between the surface that is touched by the finger 24 that is a conductive member and the switch electrode 18 is increased by the conductive member 19, so that the amount of change in capacitance when touched by the finger 24 that is the conductive member is reduced. To prevent. An electrode sheet 15 on which a switch electrode, a gnd pattern, and a wiring pattern formed of a dielectric member 16 and an elastic conductive member 19 are printed is connected to the control board 23 via the connector connection terminal 22 via the wiring pattern. Connected. The dielectric 16 that performs the switching operation is assembled by pressing the elastic conductive member 19 and the dielectric 21 that performs the switching operation with the elastic conductive member 19 as shown in FIG. It can be installed without an air layer.
With this configuration, a stable signal can be obtained without affecting the change in capacitance.

  Further, as shown in FIG. 9, even when the dielectric 21 that performs the switching operation is warped and distorted, the elastic conductive member 19 is compressed and the warping or distortion of the dielectric 21 that performs the switching operation is performed. Therefore, a stable signal can be obtained without affecting the change in capacitance.

Structure diagram of capacitive touch switch device Operation panel section Operation panel section Operation panel section Cooking heater Structure diagram of capacitive touch switch device Operation panel section Operation panel section Operation panel section

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Operation panel 2 Control board 3 Switch electrode 4 Connector connection terminal 5 Wiring pattern 6 GND pattern 7 Electrode sheet 8 Dielectric which performs switch operation 9 Double-sided tape or adhesive 10 Finger 11 C / V (capacitance is voltage) conversion circuit 12 Calculation Processing unit (CPU)
13 Air layer
DESCRIPTION OF SYMBOLS 14 Dielectric body which performs switch operation 15 Electrode sheet 16 Dielectric member 17 Double-sided tape or adhesive 18 Switch electrode 19 Elastic conductive member 20 Double-sided tape or adhesive 21 Dielectric body which performs switch operation 22 Connector connection terminal 23 Control board 24 fingers

Claims (1)

A capacitive touch switch device comprising a control board provided with a CPU and an operation panel unit connected via a connector connection terminal, and performs a switch operation with a switch electrode unit that performs a predetermined switch operation A capacitive touch switch device comprising an elastic conductive member interposed between the switch electrode unit and the dielectric panel in an operation panel unit comprising a dielectric panel to be touched by a finger .