JP2013235313A - Input device for touch switch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the input device of a capacitance type touch switch for performing an input operation by using the dielectric constant of a human body for performing a stable input operation with respect to the installation place of the touch switch in equipment or ambient use conditions such as temperature, humidity and electromagnetic noise or an instable factor such as a secular change.SOLUTION: In a touch switch input means, not only an electrode for detection of human body detection but also an electrode for reference are disposed, and the electrode for detection installed so as to be near to the finger with which an operator performs an operation and the electrode for reference installed so as to be far from the finger with which the operator performs an operation are piled up so that an electric balance between the electrode for detection and the electrode for reference can be maintained in a state that any input operation to the touch switch is not performed. When the input operation of the touch switch is performed, it is determined that electric numerical values between the electrode for detection which is near to the finger and the electrode for reference which is far from the finger deviate from each other, and the presence/absence of the input operation of the touch switch is determined.

Description

  The present invention relates to a capacitance-type touch switch that detects an operator's operation based on a change in capacitance between electrodes, and particularly relates to a touch switch electrode arrangement suitable for a wide variety of usage environments and its electrical signal processing. is there.

  A touch switch that detects a change in the frequency of the CR oscillation circuit of the touch switch detection circuit by supplying a high-frequency voltage between the conductive electrodes and increasing the capacitance between the electrodes when a human finger or the like enters the vicinity of the electrodes. Widely known. (Patent Document 1 JP 11-136116 PR, Patent Document 2 JP 2008-42724 PR, Patent Document 3 JP 2000-48694 PR)

  In addition, the frequency of the high-frequency oscillation circuit that feeds the electrodes is fixed, and the applied voltage of the touch switch detection terminal due to the increase in the electrode current due to the increase in the capacitance between the electrodes when a human finger enters the vicinity of the electrodes. A touch switch method for detecting a change is also widely known. (Patent Document 4 JP 2004-22356 PR)

  However, these capacitance methods use a slight capacitance change due to the dielectric constant of the operator's fingertips, etc., so that the capacitance change after the touch switch input unit is installed in the device, or the ambient temperature, It is easily affected by humidity, changes over time, and electromagnetic noise. If the electrical level threshold value for touch switch input determination is fixed in the initial state, erroneous determination due to the above-mentioned instability factor will occur. An example for correctly determining an input operation according to the intention of the operator has been proposed.

JP 11-136116 A JP 2008-42724 PR JP 2000-48694 PR JP 2004-22356 PR

  However, the basic requirement specifications for touch switch input devices predict various operating environments and changes over time, and then clearly determine the operator's operation and other disturbance factors, while the operator operates the touch switch. It is necessary to capture a slight change in electrostatic capacitance with high sensitivity.

  The present invention has been devised in view of such problems, and it is an object of the present invention to provide a touch switch input device with high sensitivity while eliminating factors that electrically affect the surrounding environment in the touch switch input device. And

  Therefore, the touch switch input device according to the present invention is an electrostatic capacitance type touch switch input device, and is formed of a base material formed of a material having non-conductive characteristics and a conductive material. A pair of touch switch input detection electrodes and a reference electrode having substantially the same electrode shape as the detection electrodes, provided at a position immediately below the stacking direction of the non-conductive material on which the input detection electrodes are formed. A common high-frequency generator for supplying a high-frequency voltage to each of at least one of the input detection electrode and the reference electrode via an element having a predetermined impedance; and an applied voltage supplied to the detection electrode A first rectifier that rectifies the voltage, a second rectifier that rectifies the applied voltage supplied to the reference electrode, and a potential difference between the potential of the first rectifier and the potential of the second rectifier. A potential difference unit which is characterized by comprising a comparator for comparing the voltage of each of the potential difference portion, the judgment result output for outputting the judgment result of the comparison unit (claim 1).

  Further, a gate circuit that supplies the same voltage to the same rectifier unit 3 based on a timing having a time difference output from the microcomputer between the applied voltage supplied to the detection electrode and the applied voltage supplied to the reference electrode, and switching between the gate circuits The voltage applied to the detection electrode and the voltage applied to the reference electrode are alternately A / D converted in synchronization with the timing, and the microcomputer applies the voltage applied to the detection electrode and the reference electrode. After the voltage is stored as needed, the applied voltage of the detection electrode and the applied voltage of the reference electrode are compared, and a determination result output of a touch input signal is provided based on the potential difference (claim 2).

  Further, in a single device having a touch switch having one or more sets of detection electrodes and reference electrodes, the time difference in which the voltage applied to each electrode of the detection electrodes and reference electrodes is output from the microcomputer is calculated. A gate circuit that feeds power to one or more rectifiers n, and A / D conversion of the voltage applied to each electrode in synchronization with the switching timing of the gate circuit. After the application voltage is stored at any time, the detection voltage output for each set is compared with the application voltage of the reference electrode, and a determination result output that compares the touch input signal based on the potential difference is provided. (Claim 3).

  In addition, the difference between the electrode shapes of the detection electrode and the reference electrode is that a predetermined impedance element that supplies a high-frequency voltage to each other and an applied voltage that is supplied to the detection electrode and the reference electrode are output to the rectifying unit. It is a connection portion between each terminal of the output element and each conductor of the detection electrode and the reference electrode, and the connection portion is a conductor within the touch switch input operation range of the detection electrode and the reference electrode. In addition, the feeding positions of the detection electrode and the reference electrode to the respective conductors are substantially the same (claim 4).

  Further, the predetermined impedance element that feeds the high-frequency voltage to the detection electrode and the reference electrode is an inductive element, and the stray capacitance and the series resonance circuit of each of the detection electrode and the reference electrode are provided. It is characterized by forming (claim 5).

  According to the input device of the touch switch of the present invention, since the substantially congruent detection electrode and reference electrode formed by stacking the base materials formed of the material having non-conductive characteristics are provided. , The location of the detection electrode and the reference electrode, or the ambient usage conditions such as temperature, humidity, electromagnetic noise, etc. Can be reduced. (Claim 1)

  In addition, by sharing the applied voltage rectifier circuit to the detection electrode and the reference electrode, it is possible to reduce the variation in electrical performance and reduce the component cost than providing each rectifier circuit. (Claim 3)

  In addition, the electrical connection between the detection electrode and the reference electrode reduces the stray capacitance of unnecessary wiring by supplying high-frequency voltage and connecting each element for outputting the applied voltage of each electrode at the shortest distance. As a result, each electrode raises the rate of change of capacitance change due to the operator's operation in the total capacitance, and detection with higher sensitivity becomes possible (above claim 4).

  In addition, by using a series resonant circuit for power feeding between electrodes, the dynamic range of the applied voltage between the electrodes can be expanded depending on the presence or absence of the operator's operation. In addition, the series resonant circuit itself has the function of a bandpass filter, so that the noise resistance can be improved. (Claim 5)

It is explanatory drawing which showed the block diagram of this invention of Claim 1. 1 shows the simplest circuit diagram in practicing the present invention. It is a figure which shows the transition of the input voltage of a comparison part, and a determination result output. It is the figure which showed the structure of the electrode which concerns on the best form for implementing this invention. It is a figure which shows the example of a connection of each electrode at the time of implementing this invention, the impedance element of a high frequency voltage application, and the output element to a rectifier circuit. It is a figure which shows the distance of the finger | toe which an operator operates based on this invention, each of the electrode for a detection, and the electrode for a reference | standard. It is explanatory drawing which showed the block diagram of this invention of Claim 2. It is explanatory drawing which showed the block diagram of this invention of Claim 3. It is a figure which shows the example of a connection with the output element to the impedance element of a high frequency voltage electric power feeding of Claim 4, and the rectifier circuit.

  Hereinafter, an input device of a touch switch according to the best mode for carrying out the present invention will be described with reference to the drawings. As shown in FIG. 1, the touch switch input device includes a high frequency generator 4, an impedance element (5a, 5b) for supplying a high frequency voltage to each electrode, and a finger 11 of an operator of a non-conductive substrate 2. The detection electrode 1 installed on the side close to. Furthermore, a reference electrode 3 stacked immediately below the detection electrode 1 and the non-conductive substrate 2 is provided, and a first rectification unit 6 that rectifies the applied voltage supplied to the detection electrode 1; The second rectification unit 7 that rectifies the applied voltage supplied to the reference electrode 3 and the determination result 10 of the comparison unit 9 in a non-operation state without an operation by the operator's finger 11 indicate that the non-operation electric level is In this manner, it is configured by a potential difference unit 8 that adds a potential difference to the output voltages of the first rectification unit 6 and the second rectification unit 7 in advance.

  FIG. 2 is a simplified circuit diagram for carrying out the present invention. The high frequency generator 4 is a CR oscillation circuit using an inverter as an example. The oscillation frequency may be set in a wide range of approximately 100 KHz to several MHz, the use of the input device of the touch switch, the detection distance between the operator's finger 11 and the detection electrode 1, the detection electrode 1 and the reference electrode 3. What is necessary is just to determine suitably according to the constant of the 1st rectification element 6 or the 2nd rectification element 7, and a dielectric constant of a nonelectroconductive base material, a shape, a dimension. It is not necessary to use an accurate oscillation frequency or a predetermined high-frequency voltage, and may be determined appropriately according to the specifications of the input device of the touch switch.

  Hereinafter, in FIG. 2, an outline of an operation when the operator does not perform an operation on the input device of the touch switch will be described.

  The high-frequency generator 4 oscillates at a predetermined frequency, and feeds points (5aa, 5bb) of stray capacitance formed by the detection electrode 1 and the reference electrode 3 via impedance elements (5a, 5b) having the same value. ). (Note that (11a, 11b) shown in FIG. 2 illustrates the stray capacitance due to the operator's finger and is ignored because it does not exist when not operated.) Here, the detection electrode 1 and the reference electrode 3 If each electrode shape is formed substantially the same and each electrode is formed at a close distance of the same portion of the input device of the touch switch, the floating capacitance (1cap, 3cap) of each electrode is also approximately equal. Therefore, each applied voltage waveform observed at the feeding point (5aa, 5bb) is a stray capacitance (1cap, 3cap) composed of each impedance element (5a, 5b), each electrode of the detection electrode 1 and the reference electrode 3. The waveform of each applied voltage is substantially equal.

  Next, in FIG. 2, the first rectifying unit 6 that rectifies the voltage applied to the detection electrode 1 and the second rectifying unit 7 that rectifies the voltage applied to the reference electrode 3 are elements having the same value. The rectifying elements (6c, 7c) perform half-end rectification, and the resistance elements (6a, 7a) and the capacitive elements (6d, 7d) perform smoothing. As a result, the output voltages of the output 6g of the first rectification unit 6 and the output 7g of the second rectification unit 7 are substantially equal, and as a result, the electrical level of the determination result 10 of the comparison unit 9 is fixed uniformly. Therefore, by providing the resistance element 8a of the potential difference unit 8 only between the output 7g and GNG in advance only on the output 7g side of the second rectifying unit 7, the output 7g on the reference electrode 3 side is always provided when not operated. Is set to be lower than the detection electrode 1 side.

  FIG. 3 is a diagram illustrating the operation of the comparison unit 9. When the input device of the touch switch is not operated, the (+) side input of the comparison element 9a is supplied with a lower voltage than the (−) side input, and the output of the comparison element 9a is a low level signal (hereinafter referred to as L signal). ) Is output as a determination result, and as a result, the determination result output 10 when the operator is not operating the touch switch input device is an L signal.

  Next, an outline of an operation at the time when the operator performs an operation on the input device of the touch switch will be described.

First, in the circuit diagram of FIG. 2, (11a, 11b) indicates the stray capacitance of the operator's fingertip 11 with respect to the input device of the touch switch, and the stray capacitance of the operator's fingertip 11 added to the detection electrode 1 is 11a. The stray capacitance of the operator's fingertip 11 added to the reference electrode 3 is 11b, and this capacitance is expressed by the following equation.

  From the formula (Equation 1), it can be understood that the capacitance is inversely proportional to the electrode spacing d if the dielectric constant and the electrode area are constant. As a result, as shown in FIG. 6, when the operator's finger 11 approaches the touch switch input device, the distances from the GND 1gnd of the detection electrode 1 to the operator's finger 11 are relayed to the feeding point 5aa. The distance is (1da + 1db), whereas the distance from the GND 3gnd of the reference electrode 3 to the operator's finger 11 to the feeding point 5bb is (3da + 3db). The capacitance when the finger 11 approaches the input device of the touch switch has a large floating capacitance 11a at the fingertip of the operator added to the detection electrode 1 with a short apparent electrode interval, and the apparent electrode interval It can be seen that the stray capacitance 11b at the fingertip of the operator added to the long reference electrode 3 is small.

  As described above, when the operator's finger 11 approaches the touch switch input device of the present invention, the stray capacitance 11a of the operator's finger in FIG. 2 is added to the capacitance 1cap of the detection electrode 1, and the reference electrode 3 2 is added with the stray capacitance 11b of the operator's finger in FIG. At this time, since the stray capacitance 11a of the operator's finger added to the detection electrode 1 side is larger than the stray capacitance 11b of the operator's finger added to the reference electrode 3, each high-frequency voltage is supplied to each electrode. Although both the current values of the impedance elements (5a, 5b) increase, the increase in the high-frequency current flowing on the detection electrode 1 side is larger than the increase in the high-frequency current on the reference electrode 3 side, and power is supplied by the impedance element 5a. The applied voltage of the high frequency voltage at the feeding point 5aa is lower than the applied voltage of the high frequency voltage at the feeding point 5bb fed by the impedance element 5b.

  As a result, the output voltage of the first rectifying unit 6 becomes lower than the output voltage of the second rectifying unit 7, and as shown in FIG. The high-level signal (hereinafter referred to as H signal) is output as the determination result to the output of the comparison element 9a, and the determination result output 10 that the operator's operation is performed is H Signal.

  FIG. 4 is a diagram showing an example in which the detection electrode 1 made of a conductive material, the non-conductive base material 2, and the reference electrode 3 made of a conductive material are stacked in the practice of the present invention. is there.

  FIG. 4 is a diagram showing the configuration of the electrode of the present invention. There is a detection electrode 1 on which an operator inputs an input operation, and a non-conductive base material 2 is provided thereunder. The reference electrode 3 is formed by stacking on the back surface of the non-conductive substrate 2, and the apexes (3a, 3b, 3c, 3d) of each side are stacked with the positions of the detection electrode 1 and the reference electrode 3 aligned. It shows that. In the figure, (GND) is a GND (ground) electrode in the circuit, 6b is an output terminal to the first rectification unit 6, 7b is an output terminal to the second rectification unit 7, and 5 is an oscillation circuit of a high-frequency voltage. Input terminal. Moreover, although the form of the electrode was demonstrated using the comb-shaped electrode, the electrode shape is not limited to this form.

  FIG. 5 is a diagram showing a connection example between each electrode, an impedance element to which a high-frequency voltage is applied, and an output element to the rectifier circuit when the present invention is implemented. In particular, when a printed circuit board is used for the non-conductive base material 2 of the present invention, the electrical connection between the surface of the detection electrode 1 and the surface of the reference electrode 3 is illustrated. (3e, 3g, 3f) on the surface of (3) and (3e, 3g, 3f) on the surface of the reference electrode 3 are formed so as to overlap each other and are electrically connected by through holes or the like.

  FIG. 7 is an explanatory diagram showing a block diagram of the present invention. There are many examples of using the microcomputer 14 in the input signal processing of the touch switch. In that case, the voltage applied to the detection electrode 1 and the reference electrode 3 is alternately switched by the gate 12 controlled by the microcomputer, so that the rectifier is processed only by the third rectifier 13 and is used for detection. By comparing the applied voltages of the electrode 1 and the reference electrode 3 with a microcomputer, it is possible to reduce the number of parts and improve the reliability.

  FIG. 8 is an explanatory view showing a block diagram of the present invention. Devices using touch switch input devices have one or more touch switches in the same housing, and there are many examples in which the microcomputer 14 is used in input signal processing. In that case, the rectifying unit can be switched by switching the applied voltage measurement from the detection electrode 1n = 1 to the detection electrode 1n and from the reference electrode 3n = 1 to the reference electrode 3n by the gate 12n controlled by the microcomputer. The processing is performed by the nth rectifier 13n = 1 to the nth rectifier 13n, and the applied voltage from the detection electrode 1n = 1 to the detection electrode 1n and from the reference electrode 3n = 1 to the reference electrode 3n The comparison can also be performed with a microcomputer to reduce the number of parts and improve the reliability.

  FIG. 9 is a diagram showing the electrode shapes of the detection electrode 1 and the reference electrode 3 according to claim 4. As an example, the detection electrode 1 and the reference electrode 3 are arranged on both sides of the printed circuit board, and the impedance element (5a, 5b) and the output element (6a, 7a) for outputting the applied voltage to the rectifying unit are connected to the reference electrode 3. An example of mounting on a surface will be described.

  According to the present invention, if the electrode shapes of the detection electrode 1 and the reference electrode 3 are congruent, the static relationship between the operator's finger 11, the detection electrode 1, and the reference electrode 3 is calculated according to the equation (Equation 1). It can be understood that the capacitance is inversely proportional to the distance between each electrode and the operator's finger 11, and the proximity of the operator's finger 11 to the detection electrode 1 and the reference electrode 3 can be detected with high sensitivity. Further, the feeding point 5aa to the detection electrode 1 and the feeding point 5bb to the reference electrode 3 are adjacent to each other, and the difference in the electrode shape between the detection electrode 1 and the reference electrode 3 is suppressed, so that the operator's finger 11 Is assumed to approach from not only the vertical direction of the touch switch but also from all directions of up, down, left and right, the feeding point 5aa of the impedance element 5a, the output element 6a to the first rectifying unit 6, and the impedance element 5b Since the distance between the feeding point 5bb and each connection point of the output element 7a to the second rectifying unit 7 and the operator's finger 11 can be made substantially equal, even if the frequency of the high frequency applied to each electrode is increased, the distributed constant circuit As a result, it is possible to maintain a balance, and it is possible to detect the operation of a stable touch switch.

  In FIG. 9, impedance elements (5a, 5b) for supplying power to 5aa of the detection electrode 1 and 5bb of the reference electrode 3, an output element 6a to the first rectifying unit 6, and a second The conductor connecting the output element 7a to the rectifying unit 7 and the electrode side terminal of each element are within the range of the cutting line aa in FIG. 9, and the stray capacitance other than the electrodes is suppressed. The output element 6a to the first rectification unit 6 and the output element 7a to the second rectification unit 7 are resistance elements, the stray capacitance of the detection electrode 1 and the reference electrode 3, and the first rectification. The unit 6 and the second rectifying unit 7 are separated from each other so as not to be affected by the stray capacitance associated with the wiring.

Example 1
The first embodiment of the present invention will be described below with reference to FIGS.

For example, if the input device of the touch switch for momentary operation (maintaining the operating state only while operating the touch switch) is configured using the present invention, the configuration of the block diagram of FIG. 1 can be used. The circuit diagram is as shown in FIG. 2. A CMOS IC, 74HC04 can be used for the inverter of the high-frequency generator 4, and the oscillation period T can be obtained by (Equation 2). For example, the oscillation frequency is 130 KHz, the thickness is 1.6 mm on a double-sided printed board, the board material is CEM3, the size of each electrode in FIG. 4 is about 10 × 15 mm, and the pitch of the comb electrodes is 0.254 mm. By appropriately adjusting (5a, 5b) and applying a high frequency voltage of about 4 Vp-p to each of the detection electrode 1 and the reference electrode 3, the first rectification unit 6 and the second rectification unit 7 are the same circuit. The rectifying elements (6c, 7c) are small-signal switching diodes, and half-rectify the high-frequency voltage applied to each electrode. The resistors (6a, 7a) and the capacitive elements (6e, 7e) are smoothing circuits. Any low pass filter that passes a high frequency voltage of 130 kHz or less may be used. The reason why the resistors (6a, 7a) are arranged on the electrode side from the rectifying elements (6c, 7c) is to separate the capacitance of each electrode and the stray capacitance of the rectifying unit. The resistors (6d, 7d) are discharging resistors for the smoothing circuit.

  Note that both the first rectifying unit 6 and the second rectifying unit 7 in FIG. 2 describe the second-stage smoothing circuit (6f, 6h, 7f, 7h). There is no problem.

  As described above, when the operator does not operate the touch switch input device of the present invention, the output 6g of the first rectifier 6 and the output 7g of the second rectifier 7 in FIG. Although a direct current potential of about 3.1 V is output, if the comparison unit 9 determines this potential as it is, the potentials of the output 6 g and the output 7 g may vary due to slight variations in circuit constants even during non-operation. There is a problem that the magnitude is not constant, and the determination result 10 at the time of non-operation is not fixed to the L signal or the H signal. Therefore, a resistance element 8a for adding a potential difference is provided in the potential difference unit 8, and the output 7g of the second rectification unit 7 when not operated is set to 0. 0 from the output 6g of the first rectification unit 6 as shown in FIG. By making the voltage lower by about 1V and setting the (+) terminal of the potential difference comparison element 9a to a potential lower than the (−) terminal, the L signal is output to the determination result output 10 when not operated.

  Next, when the operator operates the touch switch input device according to the present invention, when the operator's finger 11 approaches, the capacitance 1cap of the detection electrode 1 is connected to the capacitance of the operator's finger shown in FIG. The stray capacitance 11a is added, and the stray capacitance 11b of the operator's finger in FIG. 2 is added to the capacitance 3cap of the reference electrode 3. At this time, since the stray capacitance 11a of the operator's finger added to the detection electrode 1 side is larger than the stray capacitance 11b of the operator's finger added to the reference electrode 3, each high-frequency voltage is supplied to each electrode. Although both the current values of the impedance elements (5a, 5b) increase, the increase in the high-frequency current flowing on the detection electrode 1 side is larger than the increase in the high-frequency current on the reference electrode 3 side, and power is supplied by the impedance element 5a. The applied voltage of the high frequency voltage at the feeding point 5aa is lower than the applied voltage of the high frequency voltage at the feeding point 5bb fed by the impedance element 5b.

  Specifically, the potential of the output 6g of the first rectifying unit 6 during operation is reduced by about 0.2V to about 2.9V. On the other hand, the decrease in the potential of the output 7g of the second rectifying unit 7 is about 0.05V, which is about 2.95V. For this reason, as shown in FIG. 3, the potentials of the (+) terminal and the (−) terminal of the comparison element 9 a during operation are reversed from those during non-operation, thereby outputting an H signal to the determination result output 10.

  As described above, in the touch switch input device of the present invention, the determination result output 10 when the operator does not perform the operation is the L signal, and the determination result output 10 when the operator performs the operation is H signal. When the operator moves the finger 11 away from the input device of the present invention, the determination result output 10 immediately returns to the L signal, thereby achieving the function as a touch switch for momentary operation.

  In the first embodiment of the present invention, the high-frequency voltage waveform of the high-frequency generator 1 does not have to be a rectangular wave, but may be a triangular wave, a sawtooth wave, or the like, and a sine wave of only a fundamental wave that does not generate harmonics. Ideal. The circuit form of the high-frequency generator 4 is not limited to the inverter shown in FIG. 2, and may be any circuit form such as a general-purpose timer IC and an oscillation circuit using an OP amplifier. Further, since it is not necessary to continuously generate a high frequency, the high frequency voltage may be output intermittently in order to reduce power consumption.

  The touch switch input device of the present invention has a commercial power transformer in one method of the conventional touch switch grounded, the ground where the transformer is grounded, the exposed electrode of the device to be operated, and the operator's Unlike a device that accepts touch switch operations when a weak current flows between human bodies, an input function using a touch switch is effective even in a battery-powered device in which the power source of the device is not grounded. Therefore, there is no problem even if the surface of the electrode part of the touch switch is an insulator, and it is an input device of the touch switch that can be installed on a device in which printed resin, glass, etc. are provided on the front surface of the detection electrode 1. is there. In addition, for example, it is possible to arrange the detection electrode 1 on the inner layer of the multilayer substrate and to prevent the electrode from being exposed at all on the operation surface side of the printed circuit board, thereby improving the resistance to static electricity from the human body and the design. It is possible to reduce costs.

  In carrying out the present invention, a resistance element 8a for adding a potential difference at the potential difference unit 8 is provided, and the (+) terminal of the potential difference comparison element 9a of the comparison unit 9 when not operated is set to a potential lower than the (−) terminal. As a result, the L signal is output to the determination result output 10 at the time of non-operation, but as a different method, constant setting of the impedance elements (5a, 5b), or the first rectifying unit 6 and the second rectifying unit 7 (+) Of the potential difference comparison element 9a of the comparison section 9 without providing a resistance element 8a for adding a potential difference separately by the potential difference section 8 by setting constants of the resistance elements (6a, 7a, 6d, 7d) of It is also possible to set the terminal at a lower potential than the (−) terminal.

(Example 2)
In the touch switch for the momentary operation described above, if a latch function is added to the determination result output 10, an alternate operation (L signal and H signal output is repeated for each touch operation, and even if the finger is released from the touch switch, the L signal, Alternatively, a switch for holding the H signal state can be configured. For example, by connecting a CMOS IC 74HC74 (D-TYPE FLIP FLOP) to the determination result output 10, an alternate operation touch switch can be achieved.

(Example 3)
Furthermore, when a plurality of touch switch input devices of the present invention are arranged and controlled using a microcomputer, a switch called a radio switch (radio button) in which only one of a plurality of switches is always selected can be configured. It is.

  As described above, according to the input device of the touch switch according to the present invention, the touch switch is installed in the device, or the surrounding use condition such as temperature, humidity, electromagnetic noise, or unstable factors such as a change with time. An input device capable of performing a stable input operation can be provided.

DESCRIPTION OF SYMBOLS 1 Detection electrode 1cap Floating capacitance of detection electrode 1n = 1 n = 1st detection electrode 1n nth detection electrode 2 Nonconductive base material 2n = 1 n = 1st nonconductive base material 2n n-th non-conductive substrate 3 reference electrode 3a 3d indicating the overlap position 3a of the reference electrode and detection electrode 3b 3c indicating the overlap position 3b of the reference electrode and detection electrode 3c reference electrode and detection electrode 3d showing the overlapping position 3c of the reference electrode and the detecting electrode 3d showing the overlapping position 3d 3f showing the through hole position 3e of the reference electrode and the detecting electrode 3f showing the through hole position 3f of the reference electrode and the detecting electrode 3g reference 3 cap showing the through hole position 3g of the electrode for detection and the electrode for detection 3 st floating capacitance of the reference electrode 3 n = 1 n = 1 first reference electrode 3 n n th reference electrode 4 high frequency generator 5 impedance element 5a Detection electrode impedance element 5aa Feed point to detection electrode 5an = 1 n = 1st detection electrode impedance element 5an nth detection electrode impedance element 5b Reference electrode impedance element 5bn = 1 n = 1 5th reference electrode impedance element 5bn nth reference electrode impedance element 5bb Feed point to reference electrode 6 First rectifier 6a Detection electrode output element 6b First rectifier 6 output terminal 6c 1st Rectifying element of 1 rectifying unit 6d discharge resistance of first rectifying unit 6e smoothing capacitive element of first rectifying unit 6f second-stage smoothing resistive element of second rectifying unit 6g voltage of first rectifying unit Output point 6h Second-stage smoothing capacitive element of the first rectifier 7 Second rectifier 7a Reference electrode output element 7b Output terminal 7c to the second rectifier 7 2d Rectifying Element 7d Discharge Resistance of Second Rectifying Unit 7e Smoothing Capacitance Element of Second Rectifying Unit 7f Second Stage Smoothing Resistive Element of Second Rectifying Unit 7g Output of Second Rectifying Unit Point 7h Second-stage smoothing capacitive element of the second rectification unit 8 Potential difference unit 8a Resistance element for adding potential difference 9 Comparison unit 9a Potential difference comparison element 10 Determination result output 11 Operator's finger 11a On the detection electrode side The operator's finger stray capacitance 11b The operator's finger stray capacitance 12b on the reference electrode side The gate circuit 12n The gate circuit 13 having the switching function of the n pieces The third rectifier 13n = 1 The 13n = 1 rectifier 13n 13th rectifier 14 Microcomputer

Claims (5)

An input device for a capacitance type touch switch, comprising a base material formed of a material having non-conductive characteristics, a pair of touch switch input detection electrodes formed of a conductive material, and the input Provided at a position immediately below the stacking direction of the non-conductive material on which the detection electrode is formed, the reference electrode having the same electrode shape as the detection electrode, and at least the input detection electrode and the reference electrode A common high-frequency generator for supplying the high-frequency voltage to each one of the electrodes through an element having a preset impedance; a first rectifier for rectifying the applied voltage supplied to the detection electrode; and the reference A second rectifying unit that rectifies an applied voltage supplied to the electrode, a potential difference unit that adds a potential difference between the potential of the first rectifying unit and the potential of the second rectifying unit, and each voltage of the potential difference unit The Compare and a comparison unit for comparing the touch input signal based on the potential difference, and further comprising a determination result output for outputting the judgment result of the comparison section, the input device of the touch switch. A gate circuit that feeds the applied voltage fed to the detection electrode and the applied voltage fed to the reference electrode to the same rectifier 3 based on a timing having a time difference output from the microcomputer, and a switching timing of the gate circuit Synchronously, the voltage applied to the detection electrode and the voltage applied to the reference electrode are alternately A / D converted, and the microcomputer applies the voltage applied to the detection electrode and the voltage applied to the reference electrode. The comparison unit according to claim 1, further comprising a comparison unit that compares the applied voltage of the detection electrode and the applied voltage of the reference electrode, and a determination result output that outputs a determination result of the comparison unit after being stored as needed. A touch switch input device according to claim 1. In a single device having a touch switch having at least one pair of detection electrode and reference electrode, timing having a time difference in which the voltage applied to each electrode of the detection electrode and reference electrode is output from the microcomputer Based on the above, the gate circuit for supplying power to one or more rectifiers n, A / D conversion of the voltage applied to each electrode in synchronization with the switching timing of the gate circuit, After storing the applied voltage as needed, a comparison unit for comparing the applied voltage of the detection electrode and the applied voltage of the reference electrode for each set and a determination result output for outputting the determination result of the comparison unit are provided. 2. The touch switch input device according to claim 1, wherein the input device is a touch switch. The difference between the electrode shape of the detection electrode and the reference electrode is that a predetermined impedance element that feeds a high-frequency voltage respectively, and an output element that outputs an applied voltage fed to the detection electrode and the reference electrode to the rectifying unit Each of the terminals, and a connection portion between the detection electrode and the reference electrode conductor, and the connection portion is a conductor within the touch switch input operation range of the detection electrode and the reference electrode. 5. The touch switch input device according to claim 1, wherein feed positions to the conductors of the detection electrode and the reference electrode are substantially the same. 6. The predetermined impedance elements that supply high-frequency voltages to the detection electrode and the reference electrode are inductive elements, and form a series resonance circuit with the stray capacitance of each of the detection electrode and the reference electrode. The touch switch input device according to claim 1, wherein the input device is a touch switch.