JP5939225B2 - Capacitive switch - Google Patents

Description

  The present invention relates to a capacitive switch that operates based on a change in capacitance.

  Patent Document 1 discloses a capacitive switch that includes an operation plate that forms a plurality of operation surfaces that are touch-operated by a user's fingertips, and electrodes that are arranged to face each operation surface. The capacitance of the electrode changes by bringing the fingertip into contact with the operation surface. Therefore, in this type of capacitance type switch, it is detected that a contact operation has been performed when the amount of change in capacitance exceeds a predetermined threshold.

  Further, Patent Document 1 specifies as to which of the target operation surfaces the user is trying to operate when the user accidentally touches a plurality of operation surfaces at the same time as follows. . In other words, the priority is set lower for the operation surface that is more likely to be erroneously operated among multiple operation surfaces, and when contact is detected on multiple operation surfaces at the same time, the operation with the higher priority is performed. The surface is specified as the target operation surface.

Japanese Patent Laid-Open No. 4-123737

  However, the priority order changes depending on the positional relationship between the operation plate and the user, the posture when the user operates, and the like. For this reason, the conventional method in which the operation surface that the user is trying to operate is specified according to the uniformly set priority order has a limit in specifying with high accuracy.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a capacitance type switch that can accurately identify which operation surface the user is trying to operate. is there.

  The invention disclosed herein employs the following technical means to achieve the above object. It should be noted that the reference numerals in parentheses described in the claims and in this section indicate the correspondence with the specific means described in the embodiments described later as one aspect, and the technical scope of the present invention It is not limited.

  One of the disclosed inventions is an operation plate (10) that forms a plurality of operation surfaces (11, 12, 13, 14, 15, 16) that are operated by contact with the operation body (F), and an operation plate. Detection means for acquiring a detection value corresponding to the amount of change in capacitance generated between the electrode (21, 22, 23, 24, 25, 26) disposed on the opposite side of the operation surface and the operation body and the electrode (41) and contact determination means (42) for determining that the operating body is in contact with the corresponding operation surface when the detected value exceeds a predetermined threshold (TH), and contact determination means (42). And a specifying unit (43) for specifying which of the plurality of operation surfaces is the target operation surface when there are a plurality of operation surfaces determined to be present at the same time.

  Then, the specifying means detects first operation selecting means (S13) for selecting the operation surface having the maximum detection value as the first candidate operation surface, and detecting a plurality of operation surfaces determined to be in contact with each other. Among the values, there is a difference calculation means (S14) for calculating a difference (ΔV1, ΔV2, ΔV3) between the detection value of the first candidate operation surface and the detection value of the other operation surface, and the difference is a predetermined value (A It is characterized in that the first candidate operation surface is specified as a target operation surface on the condition that it is as described above.

  According to this, even if it is the 1st candidate operation surface where the variation | change_quantity of electrostatic capacitance is the maximum, when the said difference is not large enough, it will not be specified as the target operation surface. Further, when the difference is sufficiently large, the first candidate operation surface having the maximum capacitance change amount is specified as the target operation surface.

  For example, there is a case where a position shifted slightly above the center of the fifth switch SW5 that is a target operation surface is touch-operated as shown in FIG. In this case, the second switch SW2 may be contact-detected simultaneously with the fifth switch SW5. Therefore, in the method described in Patent Document 1 described above, when a switch having a high priority is set as the second switch SW, the second switch SW2 is erroneously specified as the target switch.

  On the other hand, according to the above invention, even in the situation of FIG. 6, if the capacitance change amount of the fifth switch SW5 is maximized and the difference is equal to or greater than a predetermined value, the fifth switch SW5 is used. Is correctly identified as a switch.

  Further, for example, the positional relationship between the operation plate and the user differs depending on whether the user in the passenger seat of the vehicle operates or the user in the driver seat operates. In the method described in Patent Document 1 described above, the priority order of the switches SW1 and SW4 located on the left may be set high assuming that the user is located on the right side of the operation plate. According to this setting, even if the fingertip is brought into contact with the first switch SW1, the first switch SW1 is correctly specified as the target switch even if the palm of the hand accidentally touches the fifth switch SW5. However, as shown in FIG. 8, when the user located on the left side of the operation plate operates the second switch SW2 with a fingertip, the palm may touch the fourth switch SW4 by mistake. In this case, the fourth switch SW4 having a high priority is erroneously specified as the target switch.

  On the other hand, according to the above invention, even if the operation plate is operated from either the right side or the left side, the capacitance change amount of the target switch is maximized and the difference is not less than a predetermined value. The target switch is correctly identified.

  As described above, according to the above-described invention, compared with the conventional case where the target operation surface is specified by relying only on the priority order, the specifying result by the specifying means is the positional relationship between the operation plate and the user and the user's operation posture. It becomes difficult to be affected by such as. Therefore, it becomes possible to accurately identify which operation surface the user is trying to operate.

The front view which shows the electrostatic capacitance type switch which concerns on 1st Embodiment of this invention. Sectional drawing which follows the II-II line | wire of FIG. The flowchart which shows the procedure of the control which identifies the operation surface which a user is going to operate in 1st Embodiment, and switches on a switch. The figure which shows an example of the condition which touched the some operation surface accidentally in 1st Embodiment. The figure which shows distribution of the detected value in the condition of FIG. The figure which shows an example of the condition which touched the some operation surface accidentally in 1st Embodiment. The figure which shows distribution of the detected value in the condition of FIG. The figure which shows an example of the condition which touched the some operation surface accidentally in 1st Embodiment. The figure which shows distribution of the detected value in the condition of FIG. The flowchart which shows the procedure of control by the electrostatic capacitance type switch which concerns on 2nd Embodiment of this invention. The flowchart which shows the procedure of control by the electrostatic capacitance type switch which concerns on 3rd Embodiment of this invention.

  A plurality of modes for carrying out the invention will be described below with reference to the drawings. In each embodiment, parts corresponding to the matters described in the preceding embodiment may be denoted by the same reference numerals, and redundant description may be omitted. When only a part of the configuration is described in each mode, the other modes described above can be applied to the other parts of the configuration. Not only combinations of parts that clearly show that combinations are possible in each embodiment, but also combinations of the embodiments even if they are not explicitly stated unless there is a problem with the combination. Is also possible.

(First embodiment)
The capacitive switch according to the present embodiment is mounted on a vehicle and is assumed to be operated by a vehicle occupant, and can be operated from either the driver seat or the passenger seat in the passenger compartment. Placed in position. Specifically, a capacitance type switch is assembled to an instrument panel on which various meters and display devices are assembled. As shown in FIGS. 1 and 2, the capacitance type switch includes an operation plate 10, an electrode sheet 20, and a circuit board 30 described below.

  The operation plate 10 is a resin plate member and forms a decorative surface 10a that is visually recognized by the user. The decorative surface 10 a has a plurality of operation surfaces 11, 12, 13, 14, 15, and 16. On these operation surfaces 11 to 16, characters, symbols, figures, and the like representing the setting contents of the operation target are printed. In the example illustrated in FIG. 1, the operation target is an air conditioner 50 that air-conditions the interior of the vehicle. For example, activation of the air conditioner 50, air volume setting, temperature setting, and the like can be given as specific examples of the setting contents. When the user touches the operation surfaces 11 to 16 with the fingertip F, a command signal for instructing the corresponding device to operate is output, and the air conditioner 50 operates according to the content of the contact operation.

  An electrode sheet 20 is attached to the surface of the operation plate 10 opposite to the decorative surface 10a. The electrode sheet 20 has a plurality of electrodes 21, 22, 23, 24, 25, and 26, and these electrodes 21 to 26 are held inside a resin sheet 20a. Each of the electrodes 21 to 26 is disposed so as to face the corresponding operation surfaces 11 to 16.

  A circuit board 30 is disposed on the opposite side of the operation plate 10 with respect to the electrode sheet 20. A plurality of light sources 31, 32, and 33 are mounted on the circuit board, and these light sources 31 to 33 are arranged to face the corresponding electrodes 21 to 26. Transparent electrodes such as indium tin oxide are used for the electrodes 21 to 26. In addition, a light-transmitting resin member is employed for the operation plate 10, and portions of the operation surfaces 11 to 16 that are not printed are transmitted and illuminated by the light sources 31 to 33. In addition, the coating material which has light-shielding property is printed in parts other than the operation surfaces 11-16 among the decoration surfaces 10a.

  The electrodes 21 to 26 output voltage changes that occur according to changes in capacitance as electrical signals. Therefore, when the fingertip F is brought into contact with the operation surfaces 11 to 16, the capacitance is changed, and the electric signal is also changed. Electric signals output from the electrodes 21 to 26 are input to a microcomputer (microcomputer 40) mounted on the circuit board 30. The microcomputer 40 includes a storage device that stores a program and a central processing unit that executes arithmetic processing according to the stored program. The microcomputer 40 functions as a detection unit 41, a contact determination unit 42, and a specification unit 43 described below by executing various arithmetic processes.

  The detection means 41 calculates a difference between a reference voltage preset for each of the plurality of electrodes 21 to 26 and a voltage value input as an electric signal as a detection level. The amount of change in the electrical signal corresponds to the amount of change in capacitance, and the detection level corresponds to the detection value recited in the claims. In the following description, the operation surfaces 11 to 16 and the electrodes 21 to 26 corresponding to the operation surfaces 11 to 16 are collectively represented as a first switch SW1, a second switch SW2, a third switch SW3, and a fourth switch. It is described as a switch SW4, a fifth switch SW5, and a sixth switch SW6.

  When the detection level acquired by the detection means 41 for each of the plurality of electrodes 21 to 26 exceeds a predetermined threshold TH set in advance, the contact determination means 42 It is determined that the switch has detected contact (contact detection switch).

  When there are a plurality of operation surfaces that are determined to be in contact by the contact determination unit 42 at the same time, the specifying unit 43 is the target operation surface that the user is trying to operate among the plurality of operation surfaces. Is identified. Specifically, the specific processing is executed according to the processing procedure of FIG.

  If there is one operation surface that is determined to be in contact, the microcomputer 40 changes the setting content of the air conditioner 50 that is associated with the switch corresponding to the operation surface. When there are a plurality of operation surfaces determined to be in contact, the setting content of the air conditioner 50 associated with the switch specified by the specifying unit 43 is changed. Specific examples of the setting include the above-described activation of the air conditioner, air volume setting, temperature setting, and the like. The microcomputer 40 outputs a command signal corresponding to the above setting to the air conditioner 50 and controls the operation of the air conditioner 50.

  In addition to the air conditioner 50, the capacitive switch can function the audio device 51 and the navigation device 52 as an operation target. In this case, the microcomputer 40 outputs a command signal corresponding to the setting content of the capacitance type switch to the audio device 51 and the navigation device 52, and controls the operation of these devices 51 and 52.

  FIG. 3 is a flowchart showing a procedure of processing that the microcomputer 40 repeatedly executes at a predetermined time period. First, in step S10, it is determined whether or not the contact detection switch detected by the detection means 41 exists. If it is determined that there is a plurality of contact detection switches, it is determined in the next step S11. If it is determined that there are not a plurality (S11: NO), the process proceeds to step S12. In step S12, the contact detection switch is turned on so that the contact operation of the corresponding contact detection switch functions effectively. Specifically, the setting content of the air conditioner 50 associated with the contact detection switch is changed.

  On the other hand, if it is determined that there are a plurality of contact detection switches detected by the detection means 41 due to the contact of the user's fingertip F or because the fingertip F approaches the operation surfaces 11 to 16 (S11: YES), step Proceed to S13. In step S13, the detection values of the switches SW1 to SW6 acquired by the detection means 41 are compared, and the switch with the maximum detection value is selected as the first candidate switch. The microcomputer 40 executing the process of step S13 corresponds to “first candidate selection means” described in the claims.

  In the subsequent step S14, the difference between the detection values of the switches other than the first candidate switch among the detection values of the switches SW1 to SW6 acquired by the detection means 41 and the detection value of the first candidate switch is calculated. . The microcomputer 40 executing the process of step S14 corresponds to “difference calculating means” recited in the claims.

  In subsequent step S15, it is determined whether or not the difference calculated in step S14 is equal to or larger than a predetermined value A set in advance. If an affirmative determination is made in step S15 that the difference is greater than or equal to A, the process proceeds to step S16. In step S16, the first candidate switch selected in step S13 is identified as the target switch that the user tried to operate among the plurality of contact detection switches, and the first candidate switch is turned on. The operation surface of the first candidate switch corresponds to the “first candidate operation surface” recited in the claims.

  On the other hand, if it is determined in step S15 that the difference is not greater than or equal to A, the process proceeds to step S17. In step S17, it is determined whether or not there is a switch set with a higher priority than the first candidate switch among the plurality of contact detection switches. The priority is set to a high probability of being a target switch when there are a plurality of contact detection switches.

  For example, as shown in FIG. 4, when the switches SW1, SW2, and SW3 located in the upper stage are operated to contact with the fingertip F extended from below the operation plate 10, the switch SW5 located in the lower stage in a portion other than the fingertip F. May touch. Therefore, when both the upper stage and the lower stage are detected as contact detection switches, it is desirable to specify the upper switches SW1 to SW3 as the target switches with priority over the lower switches. Therefore, the upper switches SW1 to SW3 are set to a higher priority than the lower switches.

  If it is determined in step S17 that a high priority switch exists, the process proceeds to step S18. In step S18, a second candidate switch is selected from among a plurality of contact detection switches having a higher priority than the first candidate switch. When there are a plurality of high priority switches, a switch with a high detection level is selected as the second candidate switch.

  In subsequent step S19, it is determined whether or not the difference between the detection value of the first candidate switch and the detection value of the second candidate switch, that is, the difference calculated in step S14 is less than a predetermined value B set in advance. The predetermined value B is set to a value smaller than the predetermined value A. If it is determined in step S19 that the difference is smaller than B, the process proceeds to step S20. In step S20, the second candidate switch selected in step S18 is identified as the target switch that the user tried to operate among the plurality of contact detection switches, and the second candidate switch is turned on. The operation surface of the second candidate switch corresponds to a “second candidate operation surface” recited in the claims.

  On the other hand, if it is determined in step S19 that the difference is not less than B, the process proceeds to step S21. In step S21, any of the plurality of contact detection switches that are present is prohibited from being turned on by being specified. That is, the user waits until a new contact operation is performed without being turned on even though the user is performing the contact operation.

  Next, a specific example of the processing of FIG. 3 described above will be described for each of the cases of FIG. 4, FIG. 6, and FIG.

  In the example of FIG. 4, the user places the fingertip F on the operation surface 12 of the second switch SW2 with the second switch SW2 as a target switch. However, the hand is also touching the fifth switch SW5, and as shown in FIG. 5, the detection levels of both the second switch SW2 and the fifth switch SW5 exceed the threshold value TH.

  Since the fifth switch SW5 has a higher detection level than the second switch SW2, the fifth switch SW5 is selected as the first candidate in step S13 of FIG. However, since the difference ΔV1 in the detection level between the fifth switch SW5 and the second switch SW2 is smaller than the predetermined value A, a negative determination is made in step S15, and the fifth switch SW5 is not turned on. Further, since the difference ΔV1 is less than the predetermined value B, an affirmative determination is made in step S19 and the second switch SW2 is turned on.

  In the example of FIG. 6, the user places the fingertip F on the operation surface 15 of the fifth switch SW5 with the fifth switch SW5 as a target switch. However, the fingertip F is also in proximity to the second switch SW2, and as shown in FIG. 7, the detection levels of both the second switch SW2 and the fifth switch SW5 exceed the threshold value TH.

  Since the fifth switch SW5 has a higher detection level than the second switch SW2, the fifth switch SW5 is selected as the first candidate in step S13 of FIG. Since the difference ΔV2 in the detection level between the fifth switch SW5 and the second switch SW2 is greater than the predetermined value A, an affirmative determination is made in step S15 and the fifth switch SW5 is turned on.

  In the example of FIG. 8, the user places the fingertip F on the operation surface 12 of the second switch SW2 with the second switch SW2 as a target switch. However, the hand is also touching the fourth switch SW4 and the fifth switch SW5. As shown in FIG. 9, the detection levels of the second switch SW2, the fourth switch SW4, and the fifth switch SW5 are threshold values. TH is exceeded.

  Since the fourth switch SW4 has a higher detection level than the second switch SW2, the fourth switch SW4 is selected as the first candidate in step S13 of FIG. However, since the difference ΔV3 in the detection level between the fourth switch SW4 and the second switch SW2 is smaller than the predetermined value A, a negative determination is made in step S15, and the fourth switch SW4 is not turned on. Further, since the difference ΔV2 is less than the predetermined value B, an affirmative determination is made in step S19, and the second switch SW2 is turned on.

  Although the difference ΔV4 in the detection level between the fourth switch SW4 and the fifth switch SW5 is larger than the predetermined value A, the negative determination is made in step S15 because the difference ΔV3 from the second switch SW2 is smaller than the predetermined value A. The In short, when there are a plurality of switches other than the first candidate switch among the contact detection switches, if the difference is not smaller than the predetermined value A with respect to all the other switches, a negative determination is made in step S15. .

  As described above, according to the present embodiment, the first candidate selecting unit in step S13 selects the switch having the maximum detected value as the first candidate switch. The difference calculation means in step S14 calculates the difference between the detection value of the first candidate switch and the detection value of the other switch among the contact detection switches. Then, the specifying unit 43 specifies that the first candidate switch is the target switch on the condition that the difference is equal to or greater than the predetermined value A (S15: YES).

  In the method described in Patent Document 1 described above, when there are a plurality of contact detection switches at the same time, a target switch is specified according to a preset priority order. Therefore, for example, in the situation shown in FIGS. 6 and 7, the fingertip F is placed on the fifth switch SW5, but the second switch SW2 having a higher priority is specified as the target switch. On the other hand, according to the present embodiment, even in the situation of FIG. 6, as described above, the fifth switch SW5 is specified as the target switch, and the target switch can be specified with high accuracy.

  When the fingertip F is extended from the driver's seat side (the right side in FIG. 8) and the contact operation is performed, a switch located closer to the driver's seat than the fingertip F may be touched. In view of this point, when the priority order on the driver's seat side is set high, the method described in Patent Document 1 erroneously specifies as follows. That is, for example, as shown in FIG. 8, when a user on the passenger seat side (left side in FIG. 8) performs a contact operation by extending the fingertip F, the user touches the switch SW <b> 4 positioned closer to the passenger seat side than the fingertip F. The possibility increases. For this reason, if the target switch is specified according to the priority order uniformly set as in the conventional method, the target switch cannot be specified with high accuracy. On the other hand, according to the present embodiment, even in the situation of FIG. 8, the second switch SW2 is specified as the target switch as described above, and the target switch can be specified with high accuracy.

  As described above, according to the feature 1 according to the present embodiment, the specifying result by the specifying unit 43 is based on the influence of the change in the priority order generated according to the positional relationship between the operation plate 10 and the user, the user's operation posture, and the like. It becomes difficult to receive. Therefore, it is possible to accurately identify which target switch the user is trying to operate.

  Furthermore, according to the present embodiment, the priority order is set in advance for the plurality of operation surfaces 11 to 16. The second candidate selection unit in step S18 determines that, when an operation surface having a higher priority than the first candidate operation surface exists among the plurality of operation surfaces 11 to 16 that have been determined to be in contact, the high priority Is selected as the second candidate operation surface. Then, the specifying unit 43 determines that the second candidate operation surface is the target operation surface on the condition that the difference between the detection value of the first candidate operation surface and the detection value of the second candidate operation surface is smaller than the predetermined value A. To be identified.

  According to this, as shown in FIGS. 4 and 5, for example, even if the target operation surface to be operated is not at the maximum detection level and does not become the first candidate, it is selected as the second candidate. Then, the identification means 43 identifies it.

(Second Embodiment)
In the first embodiment, as shown in FIG. 3, if it is determined in step S15 that the difference is not greater than or equal to A, if there is a switch having a higher priority than the first candidate switch, The switch is selected as the second candidate switch. On the other hand, in this embodiment, as shown in FIG. 10, if it is determined in step S15 that the difference is not greater than or equal to A, whether or not there is a switch having a higher priority than the first candidate switch. Regardless, the process proceeds to step S21. Then, in step S21, any of the plurality of contact detection switches that are present is prohibited from being specified by the specifying means 43, and is set in a standby state in which it is not turned on.

  Therefore, according to the present embodiment, the opportunity to specify the target switch is reduced as compared with the first embodiment, but the opportunity to erroneously specify a switch different from the target switch can also be reduced.

(Third embodiment)
In the first embodiment, as shown in FIG. 3, when the second candidate switch is selected in step S18, the second candidate switch is turned on on condition that the difference <B. On the other hand, in the present embodiment, as shown in FIG. 11, the process proceeds to step S20 regardless of whether or not the difference <B, and the second candidate switch is turned on. In other words, in the present embodiment, the second candidate switch is turned on on the condition that the difference <A is determined in step S15 (S15: NO).

  Therefore, according to the present embodiment, an opportunity to erroneously specify a switch different from the target switch as compared to the first embodiment increases, but an opportunity to specify the target switch also increases.

(Fourth embodiment)
In the embodiment shown in FIG. 3, the predetermined value A used for the determination in step S15 is a fixed value. On the other hand, in the present embodiment, priorities are set in advance for the plurality of operation surfaces 11 to 16, and the specifying unit 43 performs step S15 in accordance with the priority order set on the first candidate operation surface. The predetermined value A used for determination is changed. For example, the higher the rank of the first candidate switch, the lower the predetermined value A, and the easier it is to identify the first candidate switch as the target switch. A specific example of this priority order is the same order as the priority order used in the determination in step S17 of FIG.

  Therefore, according to the present embodiment, by setting a highly probable switch to be operated as a target switch to a high priority, it is possible to improve the accuracy of identifying which one is the target switch.

(Fifth embodiment)
In the embodiment shown in FIG. 3, the threshold value TH used for the determination in step S10 is set to the same value for the plurality of switches SW1 to SW6. On the other hand, in this embodiment, the threshold value TH is set to a different value for each of the switches SW1 to SW6.

  Specifically, the threshold value TH of a switch that is easily detected by mistake is set to a larger value than other switches. For example, the switches SW4, SW5, and SW6 located in the lower stage are likely to be erroneously detected as illustrated in FIGS. Therefore, the threshold value TH of the switches SW4, SW5, and SW6 located in the lower stage is set to a value larger than that of the switches SW1, SW2, and SW3 located in the upper stage. Therefore, the possibility that contact is erroneously detected in step S10 can be reduced.

  Further, the threshold value TH of the frequently used switch is set to a lower value than other switches. For example, the switches SW3 and SW6 located close to the driver's seat are assigned as frequently used switches, and the threshold values TH of these switches SW3 and SW6 are set to low values. Therefore, it becomes easy to detect a contact of a frequently used switch in step S10.

(Other embodiments)
The present invention is not limited to the description of the above embodiment, and may be modified as follows. Moreover, you may make it combine the characteristic structure of each embodiment arbitrarily, respectively.

  Operation direction detection means for detecting whether the vehicle occupant operating the operation surfaces 11 to 16 is a driver seat or a passenger seat is provided, and the priority order is changed based on the detection result. May be. For example, when the operation plate is arranged between the driver's seat and the passenger seat, if it is detected that the driver is operating from the driver's seat side, the switch closer to the driver's seat is mistaken for the switch closer to the driver's seat. Is likely to touch. For this reason, it is desirable to set a higher priority for the switch far from the driver's seat. Specific examples of the operation direction detecting means include an infrared sensor or camera for detecting the movement of the upper body of the occupant, seating sensors provided in the driver seat and the passenger seat, and the like.

  When it is in the standby state in step S21 in FIG. 3, a notification that prompts the user to correct the contact detection of the plurality of switches may be performed.

  In the embodiment shown in FIGS. 1 and 2, the electrodes 21 to 26 included in the electrode sheet 20 have a single-layer structure, and the electrodes 21 to 26 are formed separately. In contrast, an electrode sheet in which a plurality of rows of electrodes and a plurality of columns of electrodes are in a two-layer structure and these electrodes are arranged in a matrix may be employed.

  Examples include volume setting of an audio device mounted on the vehicle, music selection, destination setting of a navigation device mounted on the vehicle, and the like.

  In each of the above embodiments, it is assumed that the user's fingertip F is operated while being in contact with the operation surfaces 11 to 16, and the fingertip F is used as the operating body. On the other hand, for example, the user may hold a pen-shaped operation member and operate it by bringing the operation member into contact with the operation surfaces 11 to 16. In this case, an operation member other than the human body functions as the operation body. .

  DESCRIPTION OF SYMBOLS 10 ... Operation plate 11, 12, 13, 14, 15, 16 ... Operation surface 21, 22, 23, 24, 25, 26 ... Electrode, 41 ... Detection means, 42 ... Contact determination means, 43 ... Identification means, A ... predetermined value, F ... fingertip (operating body), S14 ... difference calculating means, TH ... predetermined threshold, [Delta] V1, [Delta] V2, [Delta] V3 ... difference.

Claims (4)

An operation plate (10) that forms a plurality of operation surfaces (11, 12, 13, 14, 15, 16) to be contact-operated by the operation body (F);
Electrodes (21, 22, 23, 24, 25, 26) disposed on the opposite side of the operation surface with respect to the operation plate;
Detection means (41) for acquiring a detection value corresponding to the amount of change in capacitance generated between the operating body and the electrode;
Contact determination means (42) for determining that the operating body is in contact with the corresponding operation surface when the detected value exceeds a predetermined threshold (TH);
Specifying means (43) for specifying which of the plurality of operation surfaces is a target operation surface when there are a plurality of the operation surfaces determined to be in contact with each other by the contact determination unit; ,
With
The specifying means is:
First candidate selecting means (S13) for selecting the operation surface having the maximum detected value as a first candidate operation surface;
Among a plurality of operation surface detection values determined to be in contact, a difference (ΔV1, ΔV2, ΔV3) between a detection value of the first candidate operation surface and a detection value of another operation surface is calculated. Difference calculation means (S14),
A capacitance type switch characterized in that the first candidate operation surface is specified as a target operation surface on condition that the difference is equal to or greater than a predetermined value (A). Priorities are preset for the plurality of operation surfaces,
The specifying means is:
If an operation surface having a higher priority than the first candidate operation surface is present among the plurality of operation surfaces determined to be in contact by the contact determination means, the higher priority In addition to having second candidate selection means (S18) for selecting the operation surface as the second candidate operation surface,
2. The capacitance type switch according to claim 1, wherein the second candidate operation surface is specified as a target operation surface on condition that the difference is smaller than the predetermined value. Priorities are preset for the plurality of operation surfaces,
The capacitance type switch according to claim 1, wherein the specifying unit changes the predetermined value in accordance with the priority order set on the first candidate operation surface.   When the difference is smaller than the predetermined value, the specification by the specification unit is prohibited for any of the operation surfaces determined to be in contact by the contact determination unit. Item 3. The capacitance type switch according to Item 1 or 2.

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