JP2015133206A - Touch switch device, and method for determining presence of contact for use in touch switch device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a touch switch device in which the extendability of function is enhanced, and to provide a method for determining the presence of contact for use in such a touch switch device.SOLUTION: A touch switch device 1 includes a plurality of switch parts 2A, 2B, and a determination part 5 for determining the presence of contact in each of the plurality of switch parts 2A, 2B. When changing from a state where there is no contact to a state where there is contact of the same condition, the plurality of switch parts 2A, 2B change to capacities different from each other, and the determination part 5 determines the presence of contact in each of the plurality of switch parts 2A, 2B, depending on the change in the sum of capacities of the plurality of switch parts 2A, 2B.

Description

  The present invention relates to a touch switch device and a contact presence / absence determination method used in the touch switch device.

  As a conventional touch switch device, for example, there is one provided with a plurality of switch portions each having a cover, a dielectric such as acrylic / glass, and an electrode portion. In such a touch switch device, when a user's finger or the like comes into contact with the cover, electrostatic coupling occurs, and the capacitance of the switch unit increases. When the finger or the like moves away from the cover, the capacitance of the switch unit decreases. Different combinations of signal lines are connected to each of the electrode portions. The discriminating unit identifies a signal line whose voltage value increases with an increase in capacitance from a plurality of signal lines, and a user or the like selects a switch unit corresponding to the identified combination of signal lines. It is determined that the switch portion is in contact (see, for example, Patent Document 1).

JP 2013-105581 A (paragraph [0010] to paragraph [0046], FIGS. 1 to 5)

  In the conventional touch switch device, the presence / absence of contact of the switch unit is determined by specifying a combination of signal lines. Therefore, for example, when increasing the number of switch units, the number of signal lines must be increased further, and the circuit wiring associated with a decrease in noise resistance, an increase in board area, an increase in cost, and the routing of a plurality of signal lines The complication of this will occur. That is, the conventional touch switch device has a problem that the expandability of the function is low.

  The present invention has been made against the background of the above problems, and provides a touch switch device with improved function expandability. The present invention also provides a method for determining the presence or absence of contact used in such a touch switch device.

  The touch switch device according to the present invention includes a plurality of switch units and a determination unit that determines presence / absence of contact in each of the plurality of switch units, and each of the plurality of switch units is the same from a state without contact. When the state changes to a state where there is a contact of conditions, the capacitance changes to mutually different capacitances, and the determination unit changes the sum of the capacitances of the plurality of switch units. The presence or absence of contact in each is discriminated.

  In the touch switch device according to the present invention, when each of the plurality of switch units changes from a state where there is no contact to a state where there is a contact under the same condition, the capacitance changes from one another, and the determination unit includes a plurality of determination units. The presence / absence of contact in each of the plurality of switch units is determined in accordance with the change in the sum of the capacitances of the switch units. Therefore, for example, when the number of switch units is increased, it is not necessary to increase the number of signal lines, so that the expandability of functions is improved.

4 is a diagram for explaining a configuration of a touch switch device according to Embodiment 1. FIG. 4 is a diagram for explaining a configuration of a touch switch device according to Embodiment 1. FIG. 4 is a diagram for explaining a configuration of a touch switch device according to Embodiment 1. FIG. 6 is a diagram for explaining a relationship between a time change of a voltage value output from a C / V conversion circuit and a threshold value of a determination unit in the touch switch device according to Embodiment 1. FIG. 6 is a diagram for explaining a processing flow of a determination unit of the touch switch device according to Embodiment 1. FIG. It is a figure for demonstrating the modification of an electrode sheet of the touch switch apparatus which concerns on Embodiment 1. FIG. FIG. 10 is a diagram for explaining a configuration of a touch switch device according to a second embodiment. FIG. 10 is a diagram for explaining a configuration of a touch switch device according to a second embodiment. FIG. 10 is a diagram for explaining a configuration of a touch switch device according to a second embodiment. FIG. 10 is a diagram for explaining a relationship between a temporal change in a voltage value output from a C / V conversion circuit and a threshold value of a determination unit in the touch switch device according to the second embodiment. FIG. 10 is a diagram for explaining a processing flow of a determination unit of the touch switch device according to the second embodiment.

Hereinafter, a touch switch device according to the present invention will be described with reference to the drawings.
In the following, the case where the touch switch device according to the present invention is a projected capacitive touch switch device is described. However, the touch switch device according to the present invention is not limited to such a case. However, other types of touch switch devices may be used. In addition, the configuration, operation, and the like described below are examples, and the touch switch device according to the present invention is not limited to such a configuration, operation, and the like. Further, the illustration of the fine structure is simplified or omitted as appropriate. In addition, overlapping descriptions are simplified or omitted as appropriate.

Embodiment 1 FIG.
The touch switch device according to Embodiment 1 will be described below.
<Configuration and operation of touch switch device>
The configuration and operation of the touch switch device according to Embodiment 1 will be described below.
1 to 3 are diagrams for explaining the configuration of the touch switch device according to the first embodiment. 1 is a front view of the touch switch device 1, FIG. 2 is a cross-sectional view of the touch switch device 1 taken along the line AA in FIG. 1, and FIG. 3 is a block diagram of the touch switch device 1. It is.

  As shown in FIGS. 1 and 2, the touch switch device 1 includes a decorative cover 11 in which contact positions 11 </ b> A and 11 </ b> B such as fingers are clearly indicated by figures, characters, and the like. The decorative cover 11 is affixed to the surface side of the acrylic resin 12 which is a dielectric. An electrode sheet 14 on which the electrode portions 14 </ b> A and 14 </ b> B are printed is attached to the back surface side of the acrylic resin 12 via an adhesive 13. The electrode sheet 14 uses a non-conductive sheet as a base material, and a conductive substance (for example, silver paste) is placed on the non-conductive sheet at positions corresponding to the contact positions 11A and 11B of the decorative cover 11. By printing, electrode portions 14A and 14B, signal lines, and the like are formed.

  The switch portion 2A is formed by the contact position 11A, the electrode portion 14A, and the region located between the contact position 11A of the acrylic resin 12 and the electrode portion 14A. When a finger or the like approaches or contacts the contact position 11A, electrostatic coupling occurs between the finger or the like and the electrode portion 14A, and the capacitance of the switch portion 2A increases. The switch part 2B is formed by the contact position 11B, the electrode part 14B, and the region located between the contact position 11B of the acrylic resin 12 and the electrode part 14B. When a finger or the like approaches or contacts the contact position 11B, electrostatic coupling occurs between the finger or the like and the electrode unit 14B, and the capacitance of the switch unit 2B increases.

  As shown in FIG. 3, the electrode portions 14 </ b> A and 14 </ b> B are connected to the C / V conversion circuit 4 through the signal line 3. The change in the sum of the capacitances in the switch units 2A and 2B is converted into a change in voltage value by the C / V conversion circuit 4. The output of the C / V conversion circuit 4 is input to the determination unit 5. Note that the C / V conversion circuit 4 may be replaced with another circuit as long as it can detect a change in the sum of capacitances in the switch units 2A and 2B.

  The discriminating unit 5 discriminates the presence / absence of contact in each of the switch units 2A and 2B based on the output of the C / V conversion circuit 4, and outputs the disc. The determination unit 5 may be configured by, for example, a microcomputer, a microprocessor unit, or the like, may be configured by an updatable component such as firmware, and is a program module that is executed by a command from the CPU or the like. It may be.

For example, the figures, characters, etc. that clearly indicate the contact positions 11A and 11B are both the same size. For example, both are squares of 100 mm ² and are large enough to be covered with an index finger. On the other hand, the electrode portions 14A and 14B have different areas. For example, the area of the electrode part 14A is 20 mm ² , and the area of the electrode part 14B is 40 mm ² . The electrode portion 14A and the electrode portion 14B are connected by a single signal line 3. That is, the switch unit 2A and the switch unit 2B are connected in parallel by the single signal line 3.

  FIG. 4 is a diagram for explaining the relationship between the temporal change in the voltage value output from the C / V conversion circuit and the threshold value of the determination unit in the touch switch device according to the first embodiment. In FIG. 4, the voltage value when the finger or the like contacts only the contact position 11A is V1, the voltage value when the finger or the like contacts only the contact position 11B is V2, and the finger or the like is applied to the contact position 11A and the contact position 11B. The voltage value at the time of simultaneous contact is represented by V3.

  As shown in FIG. 4, the voltage value when a finger or the like is not approaching or touching any of the contact position 11A and the contact position 11B is about 500 mV.

  When a finger or the like is gradually brought close to only the contact position 11A from a state where the finger or the like is not approaching or contacting any of the contact position 11A and the contact position 11B (T = 0 second to about 5 seconds in FIG. 4), the voltage The value V increases gradually. Thereafter, while the finger or the like is in contact and the state is maintained, that is, in the contact period (T = about 5 seconds to about 7 seconds in FIG. 4), the voltage value V is substantially stabilized. The voltage value V at that time is defined as V1. Thereafter, when the finger or the like is released (T = about 7 seconds to about 8 seconds in FIG. 4), the voltage value V decreases.

  When a finger or the like is gradually brought close to only the contact position 11B from a state in which the finger or the like is not approaching or contacting any of the contact position 11A and the contact position 11B (T = 0 second to about 5 seconds in FIG. 4), the voltage The value V increases gradually. Thereafter, while the finger or the like is in contact and the state is maintained, that is, in the contact period (T = about 5 seconds to about 7 seconds in FIG. 4), the voltage value V is substantially stabilized. The voltage value V at that time is defined as V2. Since the area of the electrode portion 14B corresponding to the contact position 11B is larger than the area of the electrode portion 14A corresponding to the contact position 11A, V2> V1. Thereafter, when the finger or the like is released (T = about 7 seconds to about 8 seconds in FIG. 4), the voltage value V decreases.

  When a finger or the like is gradually brought closer to both the contact position 11A and the contact position 11B from a state where the finger or the like is not approaching or touching any of the contact position 11A and the contact position 11B (T = 0 second to about 5 seconds), the voltage value V gradually increases. Thereafter, while the finger or the like is in contact and the state is maintained, that is, in the contact period (T = about 5 seconds to about 7 seconds in FIG. 4), the voltage value V is substantially stabilized. The voltage value V at that time is defined as V3. The switch unit 2A and the switch unit 2B are connected in parallel by a single signal line 3, and the voltage value V3 is a voltage corresponding to the sum of the capacitance of the switch unit 2A and the capacitance of the switch unit 2B. Therefore, V3> V2> V1. Thereafter, when the finger or the like is released (T = about 7 seconds to about 8 seconds in FIG. 4), the voltage value V decreases.

  For example, in the contact period (T = about 5 seconds to about 7 seconds in FIG. 4), the voltage value V1 is about 1000 mV, the voltage value V2 is about 1150 mV, and the voltage value V3 is about 1300 mV. In the determination unit 5, a voltage value of 925 mV is set in advance as the threshold value TH1, a voltage value of 1075 mV is set as the threshold value TH2, and a voltage value of 1225 mV is set as the threshold value TH3.

  The determination unit 5 has a case where the voltage value output from the C / V conversion circuit 4 is greater than or equal to the threshold value TH1 and less than the threshold value TH2 (hereinafter, the range may be referred to as “determination area A”). Then, it is determined that there is a contact at the contact position 11A. The determination unit 5 has a case where the voltage value output from the C / V conversion circuit 4 is greater than or equal to the threshold value TH2 and less than the threshold value TH3 (hereinafter, the range may be referred to as “determination region B”). Then, it is determined that there is a contact at the contact position 11B. When the voltage value output from the C / V conversion circuit 4 is equal to or higher than the threshold value TH3 (hereinafter, the range may be referred to as “determination area A + B”), the determination unit 5 has a contact position 11A. It is determined that there is simultaneous contact at the contact position 11B.

  Here, as shown in FIG. 4, in the state where a finger or the like is simultaneously in contact with the contact position 11 </ b> A and the contact position 11 </ b> B, the voltage value V is applied to the determination area A and the determination area B before becoming the determination area A + B. Become. Therefore, the determination unit 5 is in contact with the contact position 11A even though the finger or the like is in contact with the contact position 11A and the contact position 11B at the same time, or the finger or the like is in contact with the contact position 11B. If you are doing it, it will be mistakenly determined. Further, in a state where a finger or the like is in contact with the contact position 11B, the voltage value V becomes the determination area A before becoming the determination area B. For this reason, the determination unit 5 erroneously determines that a finger or the like is in contact with the contact position 11A even though the finger or the like is in contact with the contact position 11B.

  Therefore, particularly when the voltage value V belongs to the determination region A and the determination region B, the determination unit 5 determines whether or not it belongs to the region for a preset reference time, and is determined to belong. Only in this case, it is determined that a finger or the like is in contact with the contact position 11A or that a finger or the like is in contact with the contact position 11B.

  For example, the reference time is set to 500 ms. As shown in FIG. 4, when a finger or the like is simultaneously in contact with the contact position 11A and the contact position 11B, the period during which the voltage value V belongs to the determination region A is about 70 ms at the maximum, and the voltage value V is The maximum period belonging to the determination area B is about 100 ms. Therefore, by setting such a reference time, the determination unit 5 causes the finger or the like to contact the contact position 11A even though the finger or the like is simultaneously touching the contact position 11A and the contact position 11B. Or erroneously determining that a finger or the like is in contact with the contact position 11B is suppressed.

  Similarly, even when a finger or the like is in contact with the contact position 11B, the determination unit 5 is prevented from being erroneously determined by setting such a reference time.

  Note that erroneous determination may be suppressed by a method other than the method of determining whether or not the region belongs to the reference time set in advance. For example, the determination unit 5 may acquire the voltage value V at a preset time interval and determine whether or not it belongs to the region for a preset reference number. Alternatively, the determination unit 5 may perform a moving average process on the voltage value V and determine whether the differential value is smaller than a preset reference value. That is, when the determination unit 5 changes the voltage value output from the C / V conversion circuit 4, that is, the value corresponding to the sum of the capacitances of the switch units 2A and 2B, to a different determination region, the switch unit The presence or absence of contact between 2A and 2B may not be determined.

<Operation of discrimination unit>
Hereinafter, the operation of the determination unit of the touch switch device according to the first embodiment will be described.
FIG. 5 is a diagram for explaining the processing flow of the determination unit of the touch switch device according to the first embodiment.
As illustrated in FIG. 5, the determination unit 5 acquires the voltage value V output from the C / V conversion circuit 4 in S <b> 101.

  In S102, the determination unit 5 determines whether or not the voltage value V is greater than or equal to the threshold TH1 and less than the threshold TH2, that is, whether or not it belongs to the determination region A. Advances to S105. In S103, the determination unit 5 determines whether or not the continuous time in which the voltage value V belongs to the determination region A is longer than a preset reference time. If long, the process proceeds to S104. Return to S101. In S104, the determination unit 5 determines that there is a contact at the contact position 11A, outputs the determination, and returns to S101.

  In S105, the determination unit 5 determines whether or not the voltage value V is greater than or equal to the threshold value TH2 and less than the threshold value TH3, that is, whether or not it belongs to the determination region B. Advances to S108. In S106, the determination unit 5 determines whether or not the continuous time in which the voltage value V belongs to the determination region B is longer than a preset reference time. If long, the process proceeds to S107. Return to S101. In S107, the determination unit 5 determines that there is a contact at the contact position 11B and outputs the result, and returns to S101.

  In S108, the determination unit 5 determines whether or not the voltage value V is greater than or equal to the threshold value TH3, that is, whether or not the voltage value V belongs to the determination area A + B. If it belongs, the process proceeds to S109, and if not, the process returns to S101. In S109, the determination unit 5 determines that there is simultaneous contact between the contact position 11A and the contact position 11B, outputs the determination, and returns to S101.

<Operation of touch switch device>
The operation of the touch switch device according to Embodiment 1 will be described.
In the touch switch device 1, each of the switch portions 2A and 2B has electrode portions 14A and 14B having different areas, that is, when the state changes from a state without contact to a state with contact under the same condition, Change to capacity. And the discrimination | determination part 5 discriminate | determines the contact presence in each of switch part 2A, 2B according to the change of the sum of the electrostatic capacitance of switch part 2A, 2B. Therefore, the determination of the presence / absence of contact at the contact position 11A, the presence / absence of contact at the contact position 11B, and the presence / absence of simultaneous contact at the contact position 11A and the contact position 11B is made by a single signal line 3, that is, the signal line 3 is Since it can be realized without increasing, it is possible to suppress a reduction in noise tolerance, an increase in substrate area, an increase in cost, and a complicated substrate wiring due to the routing of a plurality of signal lines.

  In the touch switch device 1, each of the switch units 2A and 2B includes the electrode units 14A and 14B having different areas. However, the present invention is not limited to this, and the capacitance of the switch units 2A and 2B. Any other form may be used as long as a difference can be given. For example, even if the distance between the contact position 11A and the electrode part 14A is different from the distance between the contact position 11B and the electrode part 14B, the capacitance of the switch parts 2A and 2B may be different. The dielectric constant of the dielectric interposed between the contact position 11A and the electrode portion 14A may be different from the dielectric constant of the dielectric interposed between the contact position 11B and the electrode portion 14B. You may give a difference to the electrostatic capacitance of the parts 2A and 2B. When the area of the electrode portion 14A and the area of the electrode portion 14B are made different to give a difference in the capacitance of the switch portions 2A and 2B, a mask member for transferring the electrode pattern to the electrode sheet 14 or the like Since it is only necessary to change the shape, it is possible to suppress an increase in manufacturing cost and the like.

FIG. 6 is a diagram for explaining a modification of the electrode sheet of the touch switch device according to the first embodiment.
Further, in the touch switch device 1, the size of the electrode portion 14A is different from the size of the electrode portion 14B, and the area of the electrode portion 14A is different from the area of the electrode portion 14B. It is not limited to the case. For example, as shown in FIG. 6, even when the size of the electrode portion 14A is equal to the size of the electrode portion 14B and only the shape of the electrode portion 14A is mesh, the area of the electrode portion 14A And the area of the electrode portion 14B can be made different. Further, even when the shape of the electrode portion 14A and the electrode portion 14B is a mesh shape and the occupation ratios of the conductive substances are different from each other, the area of the electrode portion 14A and the area of the electrode portion 14B are Can be different.

Embodiment 2. FIG.
The touch switch device according to Embodiment 2 will be described below.
Note that description overlapping with that of the touch switch device according to Embodiment 1 is simplified or omitted as appropriate.
<Configuration and operation of touch switch device>
The configuration and operation of the touch switch device according to Embodiment 2 will be described below.
7 to 9 are diagrams for explaining the configuration of the touch switch device according to the second embodiment. 7 is a front view of the touch switch device 1, FIG. 8 is a cross-sectional view of the touch switch device 1 taken along line BB in FIG. 7, and FIG. 9 is a block diagram of the touch switch device 1. It is.

  As shown in FIGS. 7 and 8, the touch switch device 1 includes a decorative cover 11 in which contact positions 11A, 11B, and 11C such as fingers are clearly shown by figures, characters, and the like. An electrode sheet 14 on which the electrode portions 14A, 14B, and 14C are printed is attached to the back surface side of the acrylic resin 12 via an adhesive 13.

  The switch portion 2C is formed by the contact position 11C, the electrode portion 14C, and the region located between the contact position 11C of the acrylic resin 12 and the electrode portion 14C. When a finger or the like approaches or contacts the contact position 11C, electrostatic coupling occurs between the finger or the like and the electrode part 14C, and the capacitance of the switch part 2C increases.

  As shown in FIG. 9, the electrode portions 14 </ b> A, 14 </ b> B, and 14 </ b> C are connected to the C / V conversion circuit 4 through the signal line 3. A change in the sum of the capacitances in the switch units 2A, 2B, and 2C is converted into a change in voltage value by the C / V conversion circuit 4. Note that the C / V conversion circuit 4 may be replaced with another circuit as long as it can detect a change in the sum of capacitances in the switch units 2A, 2B, and 2C.

  The discriminating unit 5 discriminates the presence / absence of contact in each of the switch units 2A, 2B, and 2C based on the output of the C / V conversion circuit 4, and outputs it.

For example, the figures, characters, etc. that clearly indicate the contact positions 11A, 11B, and 11C are all the same size. For example, both are squares of 100 mm ² and are large enough to be covered with an index finger. On the other hand, the electrode portions 14A, 14B, and 14C have different areas. For example, the area of the electrode part 14A is 20 mm ² , the area of the electrode part 14B is 40 mm ² , and the area of the electrode part 14C is 80 mm ² . That is, the sum of the areas of the two electrode portions of the electrode portions 14A, 14B, and 14C is different from the area of the remaining electrode portions. Further, the electrode portion 14A, the electrode portion 14B, and the electrode portion 14C are connected by a single signal line 3. That is, the switch unit 2A, the switch unit 2B, and the switch unit 2C are connected in parallel by the single signal line 3.

  FIG. 10 is a diagram for explaining the relationship between the temporal change in the voltage value output from the C / V conversion circuit and the threshold value of the determination unit in the touch switch device according to the second embodiment. In FIG. 10, the voltage value when the finger or the like contacts only the contact position 11C is V4, the voltage value when the finger or the like simultaneously contacts the contact position 11A and the contact position 11C is V5, the contact position 11B and the contact position. The voltage value when a finger or the like is simultaneously in contact with 11C is represented by V6.

  When a finger or the like is gradually brought closer to only the contact position 11C from a state where the finger or the like is not approaching or contacting any of the contact position 11A, the contact position 11B, and the contact position 11C (T = 0 second to about 5 in FIG. 10). Second), the voltage value V gradually increases. Thereafter, while the finger or the like is in contact and the state is maintained, that is, in the contact period (T = about 5 seconds to about 7 seconds in FIG. 10), the voltage value V is substantially stabilized. The voltage value V at that time is defined as V4. Since the area of the electrode part 14C corresponding to the contact position 11C is larger than the sum of the area of the electrode part 14A corresponding to the contact position 11A and the area of the electrode part 14B corresponding to the contact position 11B, V4> V3. Thereafter, when the finger or the like is removed (T = about 7 seconds to about 8 seconds in FIG. 10), the voltage value V decreases.

  When a finger or the like gradually approaches both of the contact position 11A and the contact position 11C from a state where the finger or the like does not approach or contact any of the contact position 11A, the contact position 11B, and the contact position 11C (T = in FIG. 10). 0 seconds to about 5 seconds), the voltage value V gradually increases. Thereafter, while the finger or the like is in contact and the state is maintained, that is, in the contact period (T = about 5 seconds to about 7 seconds in FIG. 10), the voltage value V is substantially stabilized. The voltage value V at that time is defined as V5. The switch unit 2A and the switch unit 2C are connected in parallel by a single signal line 3, and the voltage value V5 is a voltage corresponding to the sum of the capacitance of the switch unit 2A and the capacitance of the switch unit 2C. Therefore, V5> V4> V1. Thereafter, when the finger or the like is removed (T = about 7 seconds to about 8 seconds in FIG. 10), the voltage value V decreases.

  When a finger or the like is gradually brought closer to both the contact position 11B and the contact position 11C from a state where the finger or the like does not approach or contact any of the contact position 11A, the contact position 11B, and the contact position 11C (T = in FIG. 10). 0 seconds to about 5 seconds), the voltage value V gradually increases. Thereafter, while the finger or the like is in contact and the state is maintained, that is, in the contact period (T = about 5 seconds to about 7 seconds in FIG. 10), the voltage value V is substantially stabilized. The voltage value V at that time is defined as V6. The switch unit 2B and the switch unit 2C are connected in parallel by a single signal line 3, and the voltage value V6 is a voltage corresponding to the sum of the capacitance of the switch unit 2B and the capacitance of the switch unit 2C. Therefore, V6> V4> V2. Further, since the area of the electrode portion 14B corresponding to the contact position 11B is larger than the area of the electrode portion 14A corresponding to the contact position 11A, V6> V5. Thereafter, when the finger or the like is removed (T = about 7 seconds to about 8 seconds in FIG. 10), the voltage value V decreases.

  For example, in the contact period (T in FIG. 10 = about 5 seconds to about 7 seconds), the voltage value V4 is about 1450 mV, the voltage value V5 is about 1600 mV, and the voltage value V6 is about 1800 mV. In the determination unit 5, a voltage value of 1375 mV is set in advance as the threshold value TH4, a voltage value of 1525 mV is set as the threshold value TH5, and a voltage value of 1675 mV is set as the threshold value TH6.

  The determination unit 5 has a case where the voltage value output from the C / V conversion circuit 4 is equal to or higher than the threshold value TH3 and lower than the threshold value TH4 (hereinafter, the range may be described as “determination region A + B”). It is determined that there is simultaneous contact between the contact position 11A and the contact position 11B. The determination unit 5 has a case where the voltage value output from the C / V conversion circuit 4 is equal to or higher than the threshold value TH4 and lower than the threshold value TH5 (hereinafter, the range may be described as “determination region C”). Then, it is determined that there is a contact at the contact position 11C. The determination unit 5 has a case where the voltage value output from the C / V conversion circuit 4 is greater than or equal to the threshold value TH5 and less than the threshold value TH6 (hereinafter, the range may be described as “determination area A + C”). It is determined that there is simultaneous contact between the contact position 11A and the contact position 11C. When the voltage value output from the C / V conversion circuit 4 is greater than or equal to the threshold value TH6 (hereinafter, the range may be described as “determination region B + C”), the determination unit 5 is in contact position 11B. It is determined that there is simultaneous contact at the contact position 11C.

  In particular, when the voltage value V belongs to the determination area A, the determination area B, the determination area A + B, the determination area C, and the determination area A + C, the determination unit 5 belongs to that area for a preset reference time. Only when it is determined whether or not it belongs, the finger or the like is in contact with the contact position 11A, the finger or the like is in contact with the contact position 11B, and the finger or the like is simultaneously in the contact position 11A and the contact position 11B. Is in contact, a finger or the like is in contact with the contact position 11C, or a finger or the like is in contact with the contact position 11A and the contact position 11C at the same time.

  For example, the reference time is set to 500 ms. As shown in FIG. 10, when a finger or the like is simultaneously in contact with the contact position 11B and the contact position 11C, the period during which the voltage value V belongs to the determination region A is about 80 ms at the maximum, and the voltage value V is The period belonging to the determination region B is about 100 ms at the maximum, the period in which the voltage value V belongs to the determination region A + B is about 90 ms at the maximum, and the period in which the voltage value V belongs to the determination region C is about 100 ms at the maximum. The period during which the voltage value V belongs to the determination area A + C is about 150 ms at the maximum. For this reason, by setting such a reference time, the determination unit 5 causes the finger or the like to come into contact with the contact position 11A even though the finger or the like is simultaneously in contact with the contact position 11B and the contact position 11C. A finger or the like is in contact with the contact position 11B, a finger or the like is in contact with the contact position 11A and the contact position 11B simultaneously, a finger or the like is in contact with the contact position 11C, or a contact position 11A and a contact An erroneous determination that a finger or the like is simultaneously in contact with the position 11C is suppressed.

  Similarly, when a finger or the like is simultaneously in contact with the contact position 11A and the contact position 11C, when a finger or the like is in contact with the contact position 11C, the finger or the like is simultaneously in contact with the contact position 11A and the contact position 11B. Even when a finger or the like is in contact with the contact position 11B, the determination unit 5 is prevented from being erroneously determined by setting such a reference time.

<Operation of discrimination unit>
The operation of the determination unit of the touch switch device according to Embodiment 2 will be described below.
FIG. 11 is a diagram for explaining the processing flow of the determination unit of the touch switch device according to the second embodiment.
As illustrated in FIG. 11, the determination unit 5 determines whether or not the voltage value V is greater than or equal to the threshold value TH3 and less than the threshold value TH4 in S208, that is, whether or not it belongs to the determination region A + B. Proceeds to S209, and if not, proceeds to S211. In S209, the determination unit 5 determines whether or not the continuous time in which the voltage value V belongs to the determination region A + B is longer than a preset reference time. If it is longer, the determination unit 5 proceeds to S210. Return to S201. In S210, the determination unit 5 determines that there is simultaneous contact between the contact position 11A and the contact position 11B, outputs the determination, and returns to S201.

  In S211, the determination unit 5 determines whether or not the voltage value V is greater than or equal to the threshold value TH4 and less than the threshold value TH5, that is, whether or not it belongs to the determination region C. If so, the process proceeds to S212. Advances to S214. In S212, the determination unit 5 determines whether or not the continuous time in which the voltage value V belongs to the determination region C is longer than a preset reference time. If it is longer, the determination unit 5 proceeds to S213. Return to S201. In S213, the determination unit 5 determines that there is a contact at the contact position 11C and outputs it, and returns to S201.

  In S214, the determination unit 5 determines whether or not the voltage value V is greater than or equal to the threshold value TH5 and less than the threshold value TH6, that is, whether or not it belongs to the determination region A + C. Advances to S217. In S215, the determination unit 5 determines whether or not the continuous time in which the voltage value V belongs to the determination region A + C is longer than a preset reference time. If longer, the process proceeds to S216. Return to S201. In S216, the determination unit 5 determines that there is simultaneous contact between the contact position 11A and the contact position 11C, outputs the determination, and returns to S201.

  In S217, the determination unit 5 determines whether or not the voltage value V is greater than or equal to the threshold value TH6, that is, whether or not it belongs to the determination region B + C. If it belongs, the process proceeds to S218, and if not, the process returns to S201. In S218, the determination unit 5 determines that there is simultaneous contact between the contact position 11B and the contact position 11C and outputs the result, and the process returns to S201.

<Operation of touch switch device>
The operation of the touch switch device according to Embodiment 2 will be described.
In the touch switch device 1, although the number of the switch portions is three, the areas of the electrode portions 14A, 14B, and 14C are made different from each other, so that the single signal line 3, that is, the number of the signal lines 3 is not increased. In addition, it is possible to determine whether or not each of the switch units 2A, 2B, and 2C is in contact. That is, in the touch switch device 1, it is possible to increase the number of the switch units indefinitely (that is, to three or more) while suppressing the increase of the signal lines 3 by making the areas of the electrode units of the switch units different from each other. Therefore, the expandability of the function is improved as compared with the conventional touch switch device.

  The signal line 3 does not necessarily need to be single. For example, when the number of switch units is greatly increased, there may be a plurality of signal lines 3 as in a conventional touch switch device, and each switch unit is connected to a different signal line 3. A plurality of electrode portions may be provided. That is, the touch switch device 1 determines the presence / absence of contact in each of the plurality of switch units according to the change in the sum of the capacitances of the plurality of switch units, and identifies the combination of the signal lines. It may be used both for determining the presence or absence of contact in each of the switch sections.

  As mentioned above, although Embodiment 1 and Embodiment 2 were demonstrated, this invention is not limited to description of each embodiment. For example, all or some of the embodiments can be combined.

  DESCRIPTION OF SYMBOLS 1 Touch switch apparatus, 2A, 2B, 2C Switch part, 3 Signal line, 4 C / V conversion circuit, 5 Discriminating part, 11 Decoration cover, 11A, 11B, 11C Contact position, 12 Acrylic resin, 13 Adhesive, 14 Electrode sheet, 14A, 14B, 14C Electrode part.

Claims (7)

A plurality of switch parts;
A discriminating unit for discriminating the presence or absence of contact in each of the plurality of switch units;
With
Each of the plurality of switch units changes to a different capacitance when changing from a state without contact to a state with contact under the same condition,
The determination unit determines presence or absence of contact in each of the plurality of switch units according to a change in the sum of the capacitances of the plurality of switch units.
A touch switch device characterized by that. Each of the plurality of switch parts has an electrode part having a different area from each other.
The touch switch device according to claim 1. The plurality of electrode portions are connected by a single signal line,
The touch switch device according to claim 2. The determination unit determines whether or not there is simultaneous contact of at least two switch units of the plurality of switch units according to a change in the sum of the capacitances of the plurality of switch units.
The touch switch device according to any one of claims 1 to 3. When the sum of the capacitances of the plurality of switch units changes from a first range to a second range that is larger than the first range, the determination unit determines that the sum is equal to the first range. In some cases, does not determine the presence or absence of contact in each of the plurality of switch parts,
The touch switch device according to claim 1, wherein the touch switch device is provided. The discriminating unit does not discriminate the presence or absence of contact in each of the plurality of switch units when the sum of the capacitances of the plurality of switch units does not continue beyond the reference time in the first range. ,
The touch switch device according to claim 5. A method for determining the presence or absence of contact, which is used in a touch switch device including a plurality of switch units that change to different capacitances when changing from a state without contact to a state with contact under the same condition,
According to a change in the sum of the capacitances of the plurality of switch units, the presence or absence of contact in each of the plurality of switch units is determined.
The contact presence / absence determination method characterized by the above.

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