JP2015106162A - Electronic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic device that enables a correct detection of an input operation responding to a state of an operation body such as a hand/finger or the like when wearing a glove or the like.SOLUTION: An electronic device 100 comprises: a static switch 30 that detects a change in static capacitance C accompanying an input operation such as a hand/finger F or the like; and an operation determination unit 52 that performs a determination of presence of an input operation on the basis of the fact that the static capacitance C detected by the static switch 30 exceeds a threshold Th. The electronic device 100 further comprises a threshold setting unit 53 that changes the threshold Th used in the operation determination unit 52 to an adjustment threshold Taj of a value equal to or more than a reference threshold Tmin, from the reference threshold Tmin as a normal value, at a lapsed time of prescribed time TA after it is determined that the input operation is performed.

Description

  The present invention relates to an electronic device including an electrostatic switch.

  2. Description of the Related Art In recent years, various electronic devices including an electrostatic switch that detects an input operation by an operating body such as a finger from a change in capacitance, such as a digital camera disclosed in Patent Document 1, have been widespread. Such an electrostatic switch includes an input detection sensor that detects a change in capacitance caused by an input operation, and an input detection unit that determines whether there is an input operation based on the capacitance detected by the input detection sensor. .

  However, the electrostatic switch as described above is generally difficult to detect a finger with a glove attached. For this reason, the configuration disclosed in Patent Document 1 further includes a sensitivity detection sensor provided at a position where it is easy to hit a finger, and a control unit that controls the sensitivity of the electrostatic switch based on the detection result of the sensitivity detection sensor. With the above configuration, even an input operation with a finger wearing a glove can be detected by an electrostatic switch.

Japanese Patent No. 4508248

  Now, since the sensitivity detection sensor of patent document 1 needs to contact with the finger | toe which hold | gripped the electronic device, it is applicable only to electronic devices like a digital camera used in a holding state. Therefore, the inventor of the present invention tried to realize an electrostatic touch switch that can correctly detect an input operation by an operating body without separately providing a configuration like the above-described sensitivity detection sensor.

  Specifically, it is conceivable to set the threshold used for determining whether or not there is an input operation to be low so that a finger with a glove can be detected. According to such a threshold value setting, the sensitivity of the electrostatic switch can be increased, so that even an input operation with a finger wearing a glove can be detected by the electrostatic switch. However, with such a threshold setting, the electrostatic switch reacts sensitively to fingers that are not wearing gloves, and thus erroneous detection may occur frequently against the operator's intention.

  Such a phenomenon is particularly noticeable in the driving environment of a car. More specifically, it is assumed that the vehicle moves up and down due to the unevenness of the road when the operator tries to release the finger by operating the electrostatic switch on the control panel. Then, the finger may touch lightly another electrostatic switch that is close to the electrostatic switch that was the operation target. In such a situation, if the sensitivity of the electrostatic switch is too sensitive, the electrostatic switch is turned on even with such an unintended light contact, resulting in false detection.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to perform an input operation by the operating body in accordance with the state of the operating body without separately providing a configuration for detecting the state of the operating body. It is an object of the present invention to provide an electrostatic touch switch capable of correctly detecting the above.

  In order to achieve the above object, one disclosed invention is an electrostatic switch (30) that detects a change in capacitance (C) accompanying an input operation by the operating body (F), and is detected by the electrostatic switch. A determination means (52) for determining whether there is an input operation by the operating body based on the determined capacitance exceeding a threshold (Th), and a predetermined time after the determination means determines that there is an input operation In (TA), a threshold value changing means (53) for changing the threshold value used in the determining means from the first threshold value (Tmin) as a normal value to a second threshold value (Taj) that is a value equal to or higher than the first threshold value; The electronic device is characterized by comprising:

  In the present invention, the sensitivity of the electrostatic switch before the input operation is increased by setting the first threshold value used for determination as a normal value low. Therefore, even when a finger wearing a glove performs an input operation as an operating body, the input operation by the operating body can be detected by the electrostatic switch.

  In addition, for a predetermined time after it is determined that there is an input operation, the threshold value used in the determination unit is changed from the first threshold value that is the normal value to the second threshold value that is equal to or greater than the first threshold value. Therefore, the sensitivity of the electrostatic switch is temporarily lowered for a predetermined time after the input operation is performed. Therefore, even when a finger or the like that is not wearing a glove is the operating body, a situation in which the electrostatic switch frequently causes false detection contrary to the operator's intention can be avoided.

  According to the above, it is possible to realize an electronic apparatus that can correctly detect an input operation by the operating body in accordance with the state of the operating body without separately providing a configuration for detecting the state of the operating body.

  Note that the reference numbers in the parentheses are merely examples of correspondences with specific configurations in the embodiments to be described later in order to facilitate understanding of the present invention, and limit the scope of the present invention. It is not a thing.

It is a figure which shows the state mounted in the vehicle of the control panel by one Embodiment of this invention. It is a front view of a control panel. It is a block diagram which shows the electrical structure of a control panel. It is a figure which shows the relationship between the peak value of the electrostatic capacitance which changes with the presence or absence of a glove, and the threshold value used for determination. It is a figure which shows the change of the electrostatic capacitance which arises by input operation with a bare hand, and the change of the threshold value accompanying it along progress of time. It is a figure which shows the change of the electrostatic capacitance which arises by input operation in the state equipped with the glove, and the change of the threshold value accompanying it along progress of time. It is a figure which shows the change of the electrostatic capacitance which arises by input operation shorter than measurement time, and the change of the threshold value accompanying it along progress of time. It is a flowchart which shows the initialization process implemented in a control circuit. It is a flowchart which shows the determination process implemented in a control circuit. It is a flowchart which shows the threshold value update process implemented in a control circuit. It is a flowchart which shows the threshold value setting process implemented in a control circuit.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  A control panel 100 according to an embodiment of the present invention shown in FIGS. 1 and 2 is an electronic device for operating an air conditioner AC mounted on a vehicle. The control panel 100 is installed in a center cluster 90a provided in the instrument panel 90 in the passenger compartment, and exposes the plurality of electrostatic switches 30 in a range where the operator's finger F can be easily reached. The operator can change the operation mode of the air conditioner AC, adjust the set value, and the like by an input operation to the electrostatic switch 30. Information indicating the operating state of the air conditioner AC is notified to the operator by display on the display 91 installed in the center cluster 90a.

  As shown in FIG. 2, the plurality of electrostatic switches 30 are arranged at intervals in the left-right direction and the vertical direction of the control panel 100. A set of fan switches 301a and 301b, a mode change switch 302, an inside / outside air change switch 303, and the like are arranged on the upper stage of the control panel 100. In the middle of the control panel 100, an auto air conditioner switch 304 and the like are arranged in addition to the front defroster switch and the rear window defogger switch. Two sets of temperature control switches 305a, 305b, 306a, 306b, and the like are arranged in the lower stage of the control panel 100.

  The fan switches 301a and 301b are assigned an air volume adjustment function for adjusting the set value of the air volume of the air conditioner AC. A mode switching switch 302 is assigned a switching function for switching the operation mode of the air outlet in a cyclic order, for example, FACE mode → BiLevel → FOOT. The inside / outside air changeover switch 303 is assigned a switching function for switching between the inside air circulation mode and the outside air introduction mode in the air conditioner AC.

  Note that a switching function that circulates three or more operation modes, such as a blowout port, is called a circulation switching function, and a switching function that changes two operation modes, such as switching between an inside air circulation mode and an outside air introduction mode. This is called simple switching function.

  The auto air conditioner switch 304 is assigned a simple switching function for switching the auto air conditioner on and off. A temperature adjustment function for adjusting a temperature setting value on the driver's seat side (see FIG. 1) in the air conditioner AC is assigned to the temperature adjustment switches 305a and 305b. A temperature adjustment function for adjusting a temperature setting value on the passenger seat side (see FIG. 1) in the air conditioner AC is assigned to the temperature adjustment switches 306a and 306b.

  2 and 3, the control panel 100 includes a switch panel member 10, a plurality of switch electrodes 20, a control circuit 50, and the like.

  The switch panel member 10 is formed, for example, by using a light-transmitting resin material processed into a plate shape as a base material, and coating the base material with a light-shielding paint or printing with a light-shielding ink. A plurality of input surfaces 11 are formed on the front surface exposed to the operator of the switch panel member 10.

  The input surface 11 is a part of the electrostatic switch 30 and is a part that contacts the finger F in the electrostatic switch 30. Each input surface 11 is formed with an icon 12 that abstracts the function assigned to each electrostatic switch 30. The icon 12 is formed by translucent painting or printing applied in place of light-shielding painting or printing. The icon 12 is lit and displayed by transmitting light from a light source (not shown) provided on the back surface 13 side of the switch panel member 10.

  The switch electrode 20 forms an electrostatic switch 30 by being combined with the input surface 11 or the like. The switch electrode 20 is formed in a film shape by a conductive polymer paint (for example, PEDOT) applied to an insulating film. The switch electrode 20 has translucency so that light from the light source can be transmitted toward the switch panel member 10. Each switch electrode 20 is attached to the back surface 13 located on the opposite side of the input surface 11 in the switch panel member 10 with a double-sided tape or an adhesive so as to overlap each icon 12, and is electrically connected to the control circuit 50. It is connected to the. The switch electrode 20 generates a capacitance C between the switch electrode 20 and the finger F touching the input surface 11. The capacitance C generated between the finger F and the switch electrode 20 changes according to the distance from the input surface 11 to the finger F. As the material for forming the switch electrode 20, for example, indium tin oxide, a metal film material having a large number of light-transmitting holes, a printing material containing a conductive substance such as carbon, or the like is employed instead of the above-described material. Is possible.

  The control circuit 50 includes a capacitance measuring unit 51, an operation determining unit 52, a threshold setting unit 53, and the like. These elements 51 to 53 may be configured by a combination of dedicated integrated circuits, or may be functional blocks of a microcomputer that executes a predetermined program. The control circuit 50 is formed on a circuit board (not shown) disposed on the back surface 13 side of the switch panel member 10.

  The capacitance measuring unit 51 acquires a change in the capacitance C detected by each electrostatic switch 30. Specifically, the capacitance measuring unit 51 acquires a signal (for example, a potential) output from each switch electrode 20 and individually measures the capacitance C generated in each electrostatic switch 30. The capacitance measuring unit 51 outputs the value of the capacitance C detected by the electrostatic switch 30 to the operation determining unit 52 and the threshold setting unit 53.

  The operation determination unit 52 acquires the measured value of the capacitance C (see FIG. 4) detected by the electrostatic switch 30 from the capacitance measurement unit 51, and acquires the acquired capacitance C and a preset threshold value. Compare with Th (see FIG. 4). The operation determination unit 52 individually holds a threshold Th for determining whether there is an input operation for each of the plurality of electrostatic switches 30. The operation determination unit 52 can reset each threshold Th based on the output from the threshold setting unit 53. The operation determination unit 52 determines whether there is an input operation with the finger F based on the fact that the capacitance C exceeds the threshold Th. In the following description, the state in which the capacitance C exceeds the threshold Th is referred to as the on state of the electrostatic switch 30, and the state in which the capacitance C is equal to or less than the threshold Th is referred to as the off state of the electrostatic switch 30. The operation determination unit 52 causes the control unit of the air conditioner AC to acquire a determination result indicating the on / off state of each electrostatic switch 30 by outputting the determination result to the outside of the control circuit 50. In addition, the operation determination unit 52 outputs the above determination result to the threshold setting unit 53.

  The threshold setting unit 53 has a timer 54. The timer 54 is configured to measure the application time of a process (described later) for temporarily changing the threshold Th. The time measured by the timer 54 is also output to the operation determination unit 52. The threshold setting unit 53 acquires the measured value of the capacitance C detected by the electrostatic switch 30 from the capacitance measuring unit 51. The threshold setting unit 53 acquires a determination result indicating the on / off state of each electrostatic switch 30 from the operation determination unit 52.

  Here, the capacitance C detected by the electrostatic switch 30 varies significantly depending on the state of the operating body such as the finger F. For example, when the operator performs an input operation with bare hands, as shown in FIG. 4, the measured peak value Cp (bf) of the capacitance surely exceeds the normal threshold Th. On the other hand, when an input operation is performed in a state where gloves are worn, the peak value Cp (gf) of the measured capacitance is greatly below the threshold Th. This is because the electric charge between the finger F and the switch electrode 20 decreases as a result of the distance between the finger F and the switch electrode 20 being increased by the interposition of the gloves.

  The threshold setting unit 53 illustrated in FIG. 3 appropriately corresponds to the state of the operating body as described above, and has a function of resetting the threshold Th held in the operation determination unit 52. In addition, the operation determination unit 52 can improve the operability of the input operation to each electrostatic switch 30 by adjusting the threshold Th. In order to acquire such an effect, the threshold setting unit 53 obtains an optimum threshold Th for detecting the finger F currently being operated from the capacitance C detected by the electrostatic switch 30 that has been input. Then, the threshold setting unit 53 outputs the calculated threshold Th to the operation determination unit 52, and temporarily changes the threshold Th held in the operation determination unit 52 after it is determined that there is an input operation. Details of the operation of the threshold setting unit 53 for changing the threshold Th will be described below with reference to FIGS.

  FIG. 5 shows the transition of the change in the capacitance C accompanying the input operation for turning on the electrostatic switch 30 between the times tb and te. The threshold Th until the electrostatic switch 30 is turned on by an input operation is set to a reference threshold Tmin as a normal value. The reference threshold value Tmin is a low value that can detect an input operation of the finger F wearing a glove (see FIG. 6). The threshold value setting unit 53 acquires a capacitance peak value Cp (bf) from when the input operation ON time tb until a preset measurement time TP (for example, 200 milliseconds) elapses.

  The threshold value setting unit 53 changes the threshold value Th from the reference threshold value Tmin to the adjustment threshold value Taj at time tc when the measurement time TP has elapsed from the on time tb. The adjustment threshold value Taj is a value that is greater than or equal to the reference threshold value Tmin and that is less than the peak value Cp (bf). The threshold value setting unit 53 multiplies the peak value Cp (bf) by using a positive fraction less than 1 as a coefficient in order to set the adjustment threshold value Taj in a range lower than the peak value Cp (bf). The adjustment threshold value Taj is calculated.

  The threshold setting unit 53 continues to change the threshold Th to the adjustment threshold Taj from the off time te when the electrostatic switch 30 switches from the on state to the off state until the time tr when the predetermined time TA has elapsed. The predetermined time TA is set to about 5 seconds, for example. The threshold setting unit 53 returns the threshold Th from the adjustment threshold Taj to the reference threshold Tmin at time tr.

  The transition of the change in the capacitance C shown in FIG. 6 is accompanied by an input operation performed by the finger F in a state where a glove is worn. The electrostatic switch 30 is turned on at the on time tb by setting the reference threshold value Tmin assuming an input operation with the glove being worn. In this input operation, the peak value Cp (gf) acquired at the measurement time TP is lower than the peak value Cp (bf) at the time of the input operation with bare hands. Therefore, the adjustment threshold value Taj remains at a value slightly higher than the reference threshold value Tmin. As will be described in detail in the threshold value setting process (see FIG. 11) described later, when the product of the capacitance peak value (gf) and the coefficient is smaller than the reference threshold value Tmin, the adjustment threshold value Taj is Are set to the same value as the reference threshold value Tmin.

  The transition of the change in the capacitance C shown in FIG. 7 is an input operation with a bare hand, and is accompanied by an input operation performed in a time shorter than the measurement time TP. Even in such a short time input operation, the threshold setting unit 53 calculates the adjustment threshold Taj by multiplying the peak value Cp (bf) measured between the on time tb and the off time te by a coefficient. The threshold setting unit 53 changes the threshold Th from the reference threshold Tmin to the adjustment threshold Taj at the off time te, not at the time tc (see FIG. 5) when the measurement time TP has elapsed from the time tb. Then, the threshold setting unit 53 continues to change the threshold Th to the adjustment threshold Taj from time te to time tr when the predetermined time TA has elapsed.

  In the control panel 100, when an input operation is applied to one of the plurality of electrostatic switches 30 shown in FIGS. 2 and 3, not only the sensitivity of the electrostatic switch (specific electrostatic switch) 30 but also other electrostatic switches. The sensitivity of the switch (non-specific electrostatic switch) 30 is also adjusted in conjunction. The threshold setting unit 53 adjusts the threshold Th for that purpose. The threshold setting unit 53 changes the threshold Th held for the specific electrostatic switch 30 from the reference threshold Tmin to the adjustment threshold Taj, and the threshold Th held for the non-specific electrostatic switch 30 is also changed from the reference threshold Tmin. The adjustment threshold value Taj is changed (see FIG. 5 and the like). The values of these adjustment threshold values Taj may differ depending on the function assigned to the specific electrostatic switch 30. Details thereof will be described below.

  Among the plurality of electrostatic switches 30, the fan switches 301a and 301b, the temperature adjustment switches 305a, 305b, 306a and 306b, and the mode changeover switch 302 can be subjected to a continuous input operation, so-called “continuous hitting”. Therefore, when any one of the switches 301a, 301b, 302, 305a, 305b, 306a, and 306b described above is the specific electrostatic switch 30, sensitivity adjustment for facilitating continuous hitting is performed.

  Specifically, the threshold setting unit 53 associates two functionally related ones among the plurality of electrostatic switches 30 as related electrostatic switches. In this embodiment, three sets of the fan switches 301a and 301b, the driver side temperature control switches 305a and 305b, and the passenger side temperature control switches 305a and 305b correspond to related electrostatic switches.

  When one of the two related electrostatic switches is the specific electrostatic switch 30, the threshold setting unit 53 sets each adjustment threshold Taj of the two related electric switches to substantially the same value. The coefficient ai when calculating the adjustment threshold value Taj of the two related electrostatic switches is, for example, about 0.6. On the other hand, each adjustment threshold value Taj of other electrostatic switches (non-related electrostatic switches) excluding two related electrostatic switches is set to a value higher than each adjustment threshold value Taj of the related electric switch. Therefore, the coefficient aj when calculating the adjustment threshold value Taj of the unrelated electrostatic switch is set to about 0.8, for example. Each of the above coefficients is not limited to the above value as long as the relationship of 0 <ai <aj <1 is satisfied, and may be changed as appropriate.

  Further, when the mode changeover switch 302 is the specific electrostatic switch 30, the threshold setting unit 53 sets the adjustment threshold Taj of the mode changeover switch 302 to a value lower than the adjustment threshold Taj of other non-specific electrostatic switches 30. . In calculating the adjustment threshold value Taj of the mode changeover switch 302, a coefficient ai of about 0.6 is used. On the other hand, a coefficient aj of about 0.8 is used for calculating the adjustment threshold value Taj of the non-specific electrostatic switch 30.

  Then, the threshold setting unit 53 substantially sets the same adjustment threshold Taj when each electrostatic switch 30 except the switches 301a, 301b, 302, 305a, 305b, 306a, and 306b is the specific electrostatic switch 30. Set to the value of. In this case, in order to reduce the sensitivity of all the electrostatic switches 30, the same coefficient ai (for example, about 0.8) is used to calculate each adjustment threshold value Taj.

  In order to realize the operation of the control panel 100 described so far, each process performed in the control circuit 50 will be described based on FIGS. 8 to 11 and with reference to FIG. Each of the following processes is started when the accessory (ACC) power source of the vehicle is turned on or the ignition of the vehicle is turned on. [I] used in the following description is an identification number assigned for identifying the electrostatic switch 30, and an integer from 1 to N (N is the number of electrostatic switches) is substituted.

  The initialization process illustrated in FIG. 8 is performed by the cooperation of the operation determination unit 52 and the threshold setting unit 53 based on the start of power supply to the control panel 100. In S1 of this initialization process, each threshold Th [i] held for each electrostatic switch 30 [i] is initialized. Specifically, the reference threshold value Tmin is sequentially substituted for all the threshold values Th [i], and the process proceeds to S2. In S2, each electrostatic switch 30 is initialized to an off state. Specifically, the OFF value is sequentially substituted for all the state values S [i] indicating the on and off states of each electrostatic switch 30 [i], and the initialization process is terminated.

  The determination process illustrated in FIG. 9 is repeatedly started by the operation determination unit 52 after the initialization process (see FIG. 8). In S11 of this determination process, in order to set each threshold Th [i] of each electrostatic switch 30 [i] to the latest value, a threshold update process (see FIG. 10) described later is performed, and the process proceeds to S12. In S12, the value to be substituted for [i] is determined, thereby selecting the electrostatic switch 30 [i] to be processed later, and the process proceeds to S13. By the processes of S12 and S22, the processes of S13 to S21 are performed for all the electrostatic switches 30 [i].

  In S13, it is determined whether or not the state value S [i] of the electrostatic switch 30 [i] selected in S12 is OFF. If an affirmative determination is made in S13, the process proceeds to S14. In S14, it is determined whether or not the current capacitance C acquired from the capacitance measuring unit 51 is equal to or greater than the threshold Th [i]. If a negative determination is made in S14, the process proceeds to S22. On the other hand, in S15 when an affirmative determination is made in S14, the state value S [i] of the electrostatic switch 30 [i] is switched from OFF to ON. In addition, in S15, the present time t is substituted as the on time tb [i] when the electrostatic switch 30 is turned on, and the process proceeds to S22.

  In S16 when a negative determination is made in S13, the measurement time TP has just elapsed from the on time tb [i] depending on whether or not the difference between the current time t and the on time tb [i] is equal to the measurement time TP. It is determined whether or not. If an affirmative determination is made in S16 as the measurement time TP elapses from the on time tb [i], the process proceeds to S20. In S20, the peak value Cp of the capacitance from the on time tb [i] to the current time t when the measurement time TP has elapsed is calculated.

  On the other hand, in S17 when a negative determination is made in S16, it is determined whether or not the current capacitance C is less than a threshold value Th [i]. If a negative determination is made in S17 due to the electrostatic switch 30 being kept pressed, the process proceeds to S22. On the other hand, when the finger F is separated from the electrostatic switch 30, a positive determination is made in S17. And S18 for determining the OFF state of electrostatic switch 30 is carried out. In S18, the state value S [i] of the electrostatic switch 30 [i] is switched from ON to OFF. In addition, in S18, the present time t is substituted as the off time te [i] when the electrostatic switch 30 [i] is turned off, and the process proceeds to S19.

  In S19, it is determined whether or not the difference between the current time t and the on time tb [i], that is, the elapsed time from the on time tb [i] to the current time t is less than the measurement time TP. If the electrostatic switch 30 has been released within a measurement time TP by an input operation in a short time, an affirmative determination is made in S19. In S20 after an affirmative determination in S19, the peak value Cp of the capacitance due to the input operation less than the measurement time TP is calculated. On the other hand, if the electrostatic switch 30 has been pressed for the measurement time TP, a negative determination is made in S19. In this case, since the peak value Cp has been calculated by the determination process up to the previous time, the process proceeds to S22.

  In S21 after S20, a threshold setting process (see FIG. 11) described later is performed by the threshold setting unit 53, and the process proceeds to S22. In S22, the process returns to S12, and the target of processing is changed to the next electrostatic switch 30 [i + 1] by incrementing the value of [i] by one. If the process of S13-S21 is performed with respect to all the electrostatic switches 30, a determination process will be complete | finished.

  The threshold update process illustrated in FIG. 10 is performed by the operation determination unit 52 and the threshold setting unit 53. This threshold value update process is a process for changing the threshold value Th [i], which has been changed from the reference threshold value Tmin to the adjustment threshold value Taj, to the reference threshold value Tmin again after a predetermined time TA has elapsed.

  In S111, by determining a value to be substituted for [i], the electrostatic switch 30 [i] to be processed later is selected, and the process proceeds to S112. By the processes of S112 and S115, the processes of S112 to S114 are performed for all the electrostatic switches 30 [i].

  In S112, it is determined whether or not the threshold value Th [i] is larger than the reference threshold value Tmin. If a negative determination is made in S112, the process proceeds to S115. If it is determined in S112 that the threshold value Th [i] exceeds the reference threshold value Tmin, the process proceeds to S113.

  In S113, it is determined whether or not the state value S [i] of the electrostatic switch 30 [i] is OFF and a predetermined time TA has elapsed from the off time te [i]. If it is determined in S113 that the predetermined time TA has not elapsed, the process proceeds to S115. On the other hand, if a positive determination is made in S113, the process proceeds to S114. In S114, the threshold setting unit 53 substitutes the reference threshold Tmin for the threshold Th [i] held in the operation determination unit 52, and the process proceeds to S115.

  In S115, the process returns to S111. In S111, by increasing the value of [i] by 1, the processing target is changed to the next electrostatic switch 30 [i + 1]. The threshold value update process is terminated when the processes of S112 to S114 are completed for all the electrostatic switches 30. Thus, the process returns to the determination process shown in FIG. 9 and S12 (see FIG. 9) is performed.

  The threshold setting process illustrated in FIG. 11 is performed by the operation determination unit 52 and the threshold setting unit 53. This threshold value setting process is a process for individually setting the value of each threshold value Th [i]. Each coefficient used in the threshold determination process satisfies the relationship 0 <ai <aj <1 as described above.

  In S211, it is determined whether or not one of the state values S [i] of the fan switches 301a and 301b (see FIG. 2), which are related electrostatic switches, is turned on. If a negative determination is made in S211, the operation proceeds to S213. On the other hand, if an affirmative determination is made in S211, in S212, the threshold Th [i] for the fan switches 301a and 301b is selected from the value obtained by multiplying the peak value Cp by the coefficient ai and the reference threshold Tmin. Set the larger value with. Further, the threshold Th [i] of the other electrostatic switches 30 (unrelated electrostatic switches) excluding the fan switches 301a and 301b is obtained by multiplying the peak value Cp by the coefficient aj and the reference threshold Tmin. Set to the larger one.

  In S213, it is determined whether or not one of the state values S [i] of the temperature adjustment switches 305a and 305b (see FIG. 2) on the driver's seat side is ON. If a negative determination is made in S213, the process proceeds to S215. On the other hand, if an affirmative determination is made in S213, in S214, the threshold Th [i] for the temperature adjustment switches 305a and 305b is calculated by multiplying the peak value Cp by the coefficient ai and the reference threshold Tmin. Set to the larger one. Further, each threshold Th [i] of the other electrostatic switches excluding the temperature adjustment switches 305a and 305b is set to a larger one of the value obtained by multiplying the peak value Cp by the coefficient aj and the reference threshold Tmin. Even when the passenger side temperature control switches 306a and 306b (see FIG. 2) are turned on, the processing corresponding to S213 and S214 is performed.

  In S215, it is determined whether or not the state value S [i] of the mode switch 302 is turned on. If a negative determination is made in S215, the process proceeds to S217. On the other hand, if an affirmative determination is made in S215, the larger one of the threshold Th [i] of the mode changeover switch 302 in S216 is the value obtained by multiplying the peak value Cp by the coefficient ai and the reference threshold Tmin. Set to. Further, each threshold Th [i] of the other electrostatic switches excluding the mode changeover switch 302 is set to the larger one of the value obtained by multiplying the peak value Cp by the coefficient aj and the reference threshold Tmin.

  In S217, the threshold value Th [i] of all the switches is set to the larger one of the value obtained by multiplying the peak value Cp by the coefficient aj and the reference threshold value Tmin, and the threshold value setting process ends. Thus, the process returns to the determination process shown in FIG. 9 and S22 is performed.

  In the present embodiment described so far, the sensitivity of the electrostatic switch 30 before the input operation is increased by setting the reference threshold Tmin low. Therefore, even when a finger F wearing a glove performs an input operation as an operating body, the input operation can be detected by the electrostatic switch 30.

  In addition, at a predetermined time TA after it is determined that there is an input operation, the threshold Th is changed from the reference threshold Tmin to the adjustment threshold Taj. Therefore, the sensitivity of each electrostatic switch 30 is temporarily lowered during the predetermined time TA. Therefore, even when the finger F or the like not wearing gloves is the operating body, a situation in which the electrostatic switch 30 frequently causes false detections contrary to the operator's intention can be avoided.

  According to the above, the control panel 100 that can correctly detect an input operation according to the state of the operating body without separately providing a configuration for detecting the state of the operating body such as the finger F is realized.

  In addition, according to the present embodiment, since the adjustment threshold value Taj is set in a range lower than the peak value Cp of the capacitance, it is determined whether there is an input operation based on the re-input operation performed within the predetermined time TA. Can be done. As described above, according to the control for setting the adjustment threshold value Taj lower than the capacitance peak value Cp, the control panel 100 avoids frequent erroneous detections and performs a reliable input operation within the predetermined time TA. It can be detected correctly.

  Further, as in the present embodiment, when the capacitance peak value Cp is multiplied by a positive decimal number less than 1 as a coefficient, an adjustment threshold value Taj in a range lower than the peak value Cp is obtained. According to such a process, the adjustment threshold value Taj corresponding to the state of the operating tool can be set. Specifically, the optimum adjustment threshold Taj is calculated according to the thickness of the glove, the strength of pressing the electrostatic switch 30, the conductivity of the surface of the finger F, and the like. Therefore, it is possible to reliably prevent the erroneous detection and to reliably detect the input operation within the predetermined time TA.

  Here, when the measured peak value Cp is low, the product of the peak value Cp and the coefficient can be a value smaller than the reference threshold value Tmin. As described above, if the adjustment threshold value Taj falls below the reference threshold value Tmin, erroneous detection is likely to occur due to excessive sensitivity increase. In order to avoid such a situation, in the present embodiment, when the product of the peak value Cp and the coefficient is smaller than the reference threshold value Tmin, the adjustment threshold value Taj is set to the same value as the reference threshold value Tmin. According to the above processing, frequent erroneous detection due to excessive sensitivity increase within the predetermined time TA can be prevented.

  Further, as in the present embodiment, in the control panel 100 in which a plurality of electrostatic switches 30 are arranged in parallel, in the process of performing an input operation to a specific electrostatic switch 30, it is erroneously detected by another electrostatic switch 30. There is a fear. Thus, when an input operation is performed on a specific electrostatic switch 30, not only the threshold Th of this specific electrostatic switch 30 but also the threshold Th of other non-specific electrostatic switches 30 is a reference threshold Tmin. To the adjustment threshold value Taj. By performing such control, it is possible to avoid a situation in which another electrostatic switch 30 erroneously detects a moving hand or the like after the input operation to the desired specific electrostatic switch 30 is finished. .

  In addition, in this embodiment, when some electrostatic switches 30 that are assumed to be repeatedly hit are specific electrostatic switches 30, the adjustment threshold Taj of the specific electrostatic switch 30 is a non-specific electrostatic switch. It is set lower than 30 adjustment threshold value Taj. Thus, according to the sensitivity of the specific electrostatic switch 30 being higher than the sensitivity of the other non-specific electrostatic switches 30, the control panel 100 can correctly detect even when the electrostatic switch 30 is repeatedly input. It becomes possible. In addition, it is possible to avoid a situation in which an input of repeated hits is erroneously detected by another electrostatic switch 30.

  In addition, according to the present embodiment, when the electrostatic switch 30 that is less likely to be repeatedly hit is the specific electrostatic switch 30, the adjustment threshold values Taj of all the electrostatic switches 30 are raised to the same value. Thus, the sensitivity of all the electrostatic switches 30 is temporarily lowered, so that the control panel 100 can quickly transition to a state in which it is difficult to cause erroneous detection.

  Furthermore, in this embodiment, when there is an input to one of two functionally related electrostatic switches, each adjustment threshold value Taj of these two related electrostatic switches is set to the value of the other unrelated electrostatic switch. It is set lower than the adjustment threshold value Taj. According to such sensitivity setting, even if an input operation is performed subsequent to the two related electrostatic switches, such a series of input operations can be correctly detected. In addition, a situation in which a series of input operations to the related electrostatic switch is erroneously detected by another electrostatic switch 30 can be prevented.

  In the present embodiment, the finger F corresponds to the “operation body” described in the claims, the reference threshold Tmin corresponds to the “first threshold” described in the claims, and the adjustment threshold Taj is the patent. This corresponds to the “second threshold value” recited in the claims. Further, the operation determination unit 52 corresponds to “determination means” described in the claims, the threshold setting unit 53 corresponds to “threshold change means” described in the claims, and the control panel 100 claims Corresponds to “electronic device” described in the range. Furthermore, the coefficient ai corresponds to the “first coefficient” described in the claims, the coefficient aj corresponds to the “second coefficient” described in the claims, and the air conditioner AC described in the claims. It corresponds to "equipment".

(Other embodiments)
As mentioned above, although one embodiment by the present invention was described, the present invention is not interpreted limited to the above-mentioned embodiment, and is applied to various embodiments and combinations within the range which does not deviate from the gist of the present invention. be able to.

  In the first modification of the above embodiment, when an input operation is applied to the specific electrostatic switch 30 that is one of the plurality of electrostatic switches 30, the adjacent electrostatic switch 30 adjacent to the specific electrostatic switch 30 is changed. Sensitivity is lowered. As a specific example, when the inside / outside air changeover switch 303 shown in FIG. 2 is a specific electrostatic switch, the auto air conditioner switch 304 and the mode changeover switch 302 correspond to adjacent electrostatic switches, and the sensitivity is lowered. By such control, a situation in which an input operation to the inside / outside air changeover switch 303 is erroneously detected by the automatic air conditioner switch 304 and the mode changeover switch 302 can be surely avoided. In particular, the auto air conditioner switch 304 is likely to be close to the hand of an operator who performs an input operation to the inside / outside air changeover switch 303. Therefore, control for reducing the sensitivity of the auto air conditioner switch 304 is particularly effective for preventing erroneous detection.

  In order to realize the sensitivity adjustment described above, in Modification 1, the adjustment threshold Taj of the adjacent electrostatic switch 30 is higher than the adjustment threshold Taj of the specific electrostatic switch 30. Specifically, S217 of the threshold setting process shown in FIG. 11 is different from the above embodiment. In the first modification, the adjustment threshold value Taj of the specific electrostatic switch 30 in which an input operation has been performed is a value obtained by multiplying the peak value Cp of the capacitance by a predetermined coefficient ai (for example, about 0.6). On the other hand, the adjustment threshold value Taj of the adjacent electrostatic switch 30 is a value obtained by multiplying the coefficient aj by the peak value Cp. Each of these coefficients satisfies the relationship of 0 <ai <aj <1 as described above. In the first modification, the threshold value Th of the other electrostatic switches 30 excluding the specific electrostatic switch 30 and the adjacent electrostatic switch 30 may not be changed to the adjustment threshold value Taj.

  In the above-described embodiment, a known technique can be appropriately applied as a method of calculating the peak value Cp of the capacitance of S21. For example, the maximum value of the capacitance C within the measurement time TP may be simply set as the peak value Cp. Or the average value of the predetermined time before and behind including the maximum value of the electrostatic capacitance C may be made into the peak value Cp. Furthermore, after removing a high frequency (noise) component from the signal of the capacitance C, the maximum value or an average value within a predetermined time including the maximum value may be set as the peak value Cp.

  In the above embodiment, the predetermined time TA, which has been about 5 seconds, can be changed as appropriate. The predetermined time TA is preferably shorter than a time that does not cause a significant change in the state of the operating body, such as wearing gloves. In addition, it is desirable that the predetermined time TA is longer than the duration of a series of operations in which the operator presses a desired electrostatic switch. Further, the measurement time TP is not limited to 200 milliseconds, and can be appropriately changed within a range in which an input operation can be detected (for example, 40 to 200 milliseconds).

  In the embodiment described above, the threshold value Th is changed from the reference threshold value Tmin to the adjustment threshold value Taj at the time tc when the measurement time TP has elapsed from the on time tb or the off time te. However, after the operation determining unit 52 determines that there is an input operation, that is, after the on time tb, the timing at which the threshold Th is changed can be changed as appropriate.

  In the embodiment described above, the adjustment threshold value Taj is set in a range lower than the capacitance peak value Cp. However, the adjustment threshold Taj may be a value higher than the peak value Cp in order to reliably prevent erroneous detection. In the above embodiment, the adjustment threshold value Taj is set by the product of the peak value Cp and the coefficients ai, aj. The adjustment threshold value Taj is a preset fixed value that does not use the measured peak value Cp. Also good. Also in the form of using a coefficient for calculating the adjustment threshold value Taj, the value of this coefficient can be changed as appropriate.

  In the above embodiment, the functions provided by the elements 51 to 53 provided in the control circuit 50 can be provided by hardware and software different from those described above, or a combination thereof.

  In the above embodiment, the example in which the present invention is applied to the control panel 100 that operates the air conditioner AC mounted on the vehicle has been described. In the control panel 100 to which the present invention is applied, the sensitivity of each electrostatic switch is temporarily lowered when the finger F is separated from the specific electrostatic switch. Therefore, even if the finger F trying to move away from a specific electrostatic switch lightly touches an unintended electrostatic switch due to the vertical movement of the vehicle due to road irregularities, the false detection of the electrostatic switch with such unintended light contact Can be prevented.

  However, the present invention is not limited to the control panel 100 of the air conditioner AC, and can be applied to an operating device for operating a vehicle-mounted device or the vehicle-mounted device itself. Furthermore, the present invention is applicable not only to vehicles but also to all electronic devices including touch switches that detect an input operation based on a change in capacitance generated between an electrode and a finger.

F finger (operation body), AC air conditioner (equipment), C capacitance, Cp capacitance peak value, TA predetermined time, Tmin reference threshold (first threshold), Taj adjustment threshold (second threshold), Th Threshold, ai coefficient (first coefficient), aj coefficient (second coefficient), 30 electrostatic switch, 301a, 301b Fan switch (related electrostatic switch), 305a, 305b, 305a, 305b Temperature control switch (related electrostatic switch) ), 52 Operation determination unit (determination unit), 53 Threshold setting unit (threshold change unit), 100 Control panel (electronic device)

Claims (14)

An electrostatic switch (30) for detecting a change in electrostatic capacity accompanying an input operation by the operating body (F);
Determining means (52) for determining whether or not there is an input operation by the operating body based on the fact that the capacitance (C) detected by the electrostatic switch exceeds a threshold (Th);
At a predetermined time (TA) after it is determined that there is an input operation by the determination means, the threshold value used by the determination means is a value equal to or greater than the first threshold value (Tmin) as a normal value. And a threshold value changing means (53) for changing to a second threshold value (Taj).   2. The electronic apparatus according to claim 1, wherein the threshold value changing unit sets the second threshold value within a range lower than a capacitance peak value (Cp) detected by the electrostatic switch.   The electronic device according to claim 2, wherein the threshold value changing unit sets a value obtained by multiplying the peak value by a predetermined coefficient as the second threshold value.   The threshold value changing means sets the second threshold value to the same value as the first threshold value when the product of the coefficient and the peak value is smaller than the first threshold value. Electronic equipment. An electronic device comprising a plurality of the electrostatic switches arranged in parallel,
The said determination means hold | maintains the said threshold value for performing presence determination of input operation separately with respect to each of the said some electrostatic switch, The Claim 1 characterized by the above-mentioned. Electronics.   The threshold value changing unit is configured to hold the threshold value held for the specific electrostatic switch during the predetermined time when it is determined that an input operation is performed on the specific electrostatic switch that is one of the plurality of electrostatic switches. Is changed from the first threshold to the second threshold, and the threshold held for another non-specific electrostatic switch different from the specific electrostatic switch is changed from the first threshold to the second threshold. The electronic device according to claim 5, wherein An electronic device in which an input operation for adjusting a set value of a connected device (AC) and an input operation for changing the operation mode of the device are performed on the electrostatic switch,
The threshold value changing means is configured to adjust the setting value of the specific electrostatic switch when the adjustment function for adjusting the set value or the circulation switching function for sequentially switching the operation mode among the plurality of the operation modes is assigned to the specific electrostatic switch. The electronic device according to claim 6, wherein a second threshold value is set to a value lower than the second threshold value of the non-specific electrostatic switch. The threshold value changing means includes
A value obtained by multiplying a peak value (Cp) of the capacitance detected by the electrostatic switch by a first coefficient (ai) defined in advance is set as the second threshold value of the specific electrostatic switch,
A value obtained by multiplying the peak value by a second coefficient (aj) defined in advance is set as the second threshold value of the non-specific electrostatic switch,
The first coefficient and the second coefficient are both greater than 0 and less than 1;
The electronic device according to claim 7, wherein the first coefficient is smaller than the second coefficient. An electronic device in which an input operation for changing an operation mode of a connected device (AC) is performed on the electrostatic switch,
The threshold value changing means, when a simple switching function for switching the operation mode between two is assigned to the specific electrostatic switch, the second threshold value of the specific electrostatic switch and the non-specific electrostatic switch. Are set to the same value, The electronic device as described in any one of Claims 6-8 characterized by the above-mentioned.   The threshold value changing unit is configured to multiply the peak value (Cp) of the capacitance detected by the electrostatic switch by a coefficient (aj) that is greater than 0 and less than 1 to the specific electrostatic switch and the specific electrostatic switch. The electronic device according to claim 9, wherein the electronic device is set as each second threshold value of a non-specific electrostatic switch. The threshold value changing means includes
Among the plurality of electrostatic switches, two functionally related ones are associated as related electrostatic switches,
When it is determined that one of the two related electrostatic switches has an input operation, the second threshold value of each of the two related electrostatic switches is set to another unrelated electrostatic switch different from the related electrostatic switch. The electronic device according to claim 5, wherein the electronic device is set to a value lower than the second threshold value of the switch. The threshold value changing means includes
A value obtained by multiplying a peak value (Cp) of the capacitance detected by the electrostatic switch by a first coefficient (ai) defined in advance is set as the second threshold value of the two related electrostatic switches,
A value obtained by multiplying the peak value by a second coefficient (aj) defined in advance is set as the second threshold value of the unrelated electrostatic switch,
The first coefficient and the second coefficient are both greater than 0 and less than 1;
The electronic device according to claim 11, wherein the first coefficient is smaller than the second coefficient.   When it is determined that the specific electrostatic switch that is one of the plurality of electrostatic switches has an input operation, the threshold value changing unit is configured to detect the second threshold value of the adjacent electrostatic switch adjacent to the specific electrostatic switch. 13 is set to a value higher than the second threshold value of the specific electrostatic switch. The threshold value changing means includes
A value obtained by multiplying a peak value (Cp) of the capacitance detected by the electrostatic switch by a first coefficient (ai) defined in advance is set as the second threshold value of the specific electrostatic switch,
A value obtained by multiplying the peak value by a second coefficient (aj) defined in advance is set as the second threshold value of the adjacent electrostatic switch,
The first coefficient and the second coefficient are both greater than 0 and less than 1;
The electronic device according to claim 13, wherein the first coefficient is smaller than the second coefficient.

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