JP5798437B2 - Touch switch - Google Patents

Description

  The present invention relates to a touch switch for detecting an input at a fingertip of a user.

  Conventionally, the use of a touch switch has been studied as an input interface for operating a navigation system, an audio device, an air conditioner, and the like. This touch switch detects the presence or absence of a finger touching the operation surface, the contact position, a slide input for moving the fingertip while making contact with the operation surface, and the like. There are a detection type and a capacitance detection type for detecting based on a change in capacitance. This is shown in FIG. 2 of Japanese Patent Application Laid-Open No. 2006-7920 (Patent Document 1).

  Incidentally, as shown in FIG. 2 of Patent Document 1, the touch switch generally detects the presence / absence of contact with a finger, the position of contact, and the like. Specifically, in a resistance detection type touch switch, for example, a direct current voltage is applied to a conductive member constituting the touch switch from a plurality of locations, and a finger comes into contact with an operation surface provided on the surface of the conductive member. As a result, the contact portion is grounded through the fingers and the human body, so that a current flows. By measuring the voltage at this time, the contact position of the finger with respect to the operation surface, the strength of contact, and the like are detected.

  However, in such a touch switch, there is a possibility that the detection accuracy may be reduced due to a change in the contact area of the fingertip with the operation surface. In other words, it is difficult to measure the voltage at a plurality of locations at the same time by detecting the contact position or the like by measuring the voltage. The voltage at a plurality of locations is measured sequentially, and the contact location or the like is detected based on the measurement result. Therefore, if the contact area of the fingertip with respect to the operation surface changes drastically, for example, if the contact area of the fingertip with the operation surface changes abruptly, the current flowing through the fingers and the human body increases or decreases, and the detection result of the contact position etc. However, there is a risk that the actual contact position and the like may be displaced.

JP 2006-7920 A

  The present invention has been made in the background of the above-described circumstances, and its solution is a novel configuration in which a decrease in detection accuracy is suppressed with respect to a change in contact area with the operation surface of the fingertip. It is to provide a touch switch having a simple structure.

That is, according to the first aspect of the present invention, a voltage is applied to the conductive member, and the presence or absence of contact with the finger on the conductive member and the movement while contacting the finger based on the energized state of the conductive member. In the touch switch to be detected, the conductive member has an operation recess that is wider than the tip of the finger, and a protrusion that protrudes from the bottom surface of the operation recess toward the opening. cage, and the projecting distal end face of the projecting portion is, is a band shape extending in a predetermined width of the narrow width than the tip portion of the該手finger, there is a operating surface of the conductive member to which the finger is in contact, characterized And

  According to the touch switch having the structure according to the first aspect as described above, the contact surface of the finger with respect to the operation surface is reduced by the contact pressure because the operation surface has a band shape narrower than the tip portion of the finger. Regardless, it is almost constant. Therefore, when a voltage is applied to the conductive member to detect the contact position of the finger based on the energized state, a decrease in detection accuracy due to a change in the contact area with the operation surface of the finger is suppressed, and a high Accurate detection is possible.

Further , according to the first aspect, since the operation surface is provided on the distal end surface of the protruding portion that protrudes from the bottom surface of the operation recess, the finger may mistakenly touch the other part of the conductive member when touching the operation surface. Touching to prevent unintended contact from being detected.

According to a second aspect of the present invention, in the touch switch described in the first aspect, the operation surface has a strip shape extending linearly in the length direction in plan view.

According to the second aspect, since the operation surface extends linearly in the length direction in plan view, the slide input is realized by the linear movement of the fingertip caused by the bending and stretching of the joint. Therefore, at the time of slide input, the tip of the finger can be moved while touching the operation surface without requiring an operation while visually recognizing.

According to a third aspect of the present invention, in the touch switch described in the first or second aspect, the width dimension w of the operation surface is set in a range of 2 mm ≦ w ≦ 7 mm.

According to the third aspect, since the width dimension of the operation surface is set within the above numerical range, it is made smaller than the width dimension of the tip portion of the human finger. The change in the contact area due to the change in the contact pressure can be reduced, and the detection accuracy of the input by the finger can be improved.

  According to the present invention, the operation surface of the conductive member is in the form of a band extending with a width that is narrower than the width of the tip of the finger that contacts the operation surface. Thereby, when the input operation is performed with the tip of the finger in contact with the operation surface, the contact area of the finger with respect to the operation surface is constant in the width direction. Therefore, the amount of change in the contact area with the operation surface of the finger is reduced, and stable and excellent detection accuracy can be realized.

The figure which shows the state by which the touch switch as the 1st Embodiment of this invention was provided in the door armrest of the motor vehicle. The figure explaining the touch switch shown by FIG. The top view which shows the electrically-conductive member of the touch switch shown by FIG. IV-IV sectional drawing of FIG. VV sectional drawing of FIG. The figure explaining the detection mechanism of the touch switch shown by FIG. FIG. 7 is an electric circuit diagram of the touch switch shown in FIG. 6. The figure explaining the use condition of the electrically-conductive member shown by FIG. The perspective view of the electrically-conductive member which comprises the touch switch as the 2nd Embodiment of this invention. The perspective view of the electrically-conductive member and insulation member which comprise the touch switch as the 3rd Embodiment of this invention.

  Embodiments of the present invention will be described below with reference to the drawings.

  1 and 2 show a touch switch 10 as an embodiment of the present invention. As shown in FIG. 1, the touch switch 10 is disposed on an armrest 12 provided on a door portion of the automobile, and serves as an input interface for opening and closing the vehicle window.

  More specifically, the touch switch 10 includes the conductive member 14 shown in FIGS. 3 to 5. The conductive member 14 is formed of a conductive material having a high electrical conductivity. In this embodiment, the conductive member 14 is formed of a conductive resin material obtained by mixing a conductive filler such as carbon black with a synthetic resin material. Then, the conductive member 14 is superposed and fixed on the upper surface of a base (not shown) having electrical insulation, for example. The conductive member 14 is made of a rubber-based conductive paint in which an organic solvent is added to a prepared rubber compound and carbon black as a conductive filler is mixed, and a printing solvent is further added. It may be formed by printing in a predetermined shape on the upper surface of the substrate by a method such as printing, flexographic printing, gravure printing, pad printing, or lithography. Furthermore, the conductive member 14 can be formed of a conductor such as a metal plate.

  In addition, the lower surface of the conductive member 14 is superimposed and fixed on the upper surface of a base (not shown), and an operation surface 16 is provided on the upper surface of the conductive member 14. The operation surface 16 is a belt-like flat surface extending linearly in the front-rear direction (right and left in FIG. 3) in plan view. And the presence or absence of the contact with the operation surface 16 of the finger 44 mentioned later and the movement while contacting are detected based on the change of an energization state.

  A first DC power supply 20 is connected to one end of the conductive member 14, and a DC voltage is applied from the first DC power supply 20 to one end of the conductive member 14. On the other hand, a second DC power source 22 is connected to the other end of the conductive member 14, and a DC voltage is applied from the second DC power source 22 to the other end of the conductive member 14. The first and second DC power supplies 20 and 22 apply in-phase and same-potential voltages to the conductive member 14 from two locations, and the conductive member 14 is not contacted with a finger 44 described later. No current flows.

  The first detection resistor 24 is connected to one end of the conductive member 14. The first detection resistor 24 is disposed on a connection path between the one end of the conductive member 14 and the first DC power supply 20 and is electrically connected to the conductive member 14 and the first DC power supply 20. ing. On the other hand, the second detection resistor 26 is connected to the other end of the conductive member 14. The second detection resistor 26 is disposed on a connection path between the other end of the conductive member 14 and the second DC power supply 22, and is electrically connected to the conductive member 14 and the second DC power supply 22. Has been. The first and second detection resistors 24 and 26 have the same resistance value (R ′).

  Further, a first voltmeter 28 for measuring the voltage applied to the first detection resistor 24 is provided, and a first voltage meter for measuring the voltage applied to the second detection resistor 26 is provided. Two voltmeters 30 are provided. Then, by confirming the energization state of the conductive member 14 based on the measured values of the first and second voltmeters 28 and 30, the presence / absence of contact of the finger 44 to the conductive member 14 described later and the contact position are detected. It has come to be.

  Further, the first and second voltmeters 28 and 30 are connected to the processing device 32 by wire or wirelessly. The processing device 32 includes a contact confirmation unit 34 that determines whether or not the finger 44 is in contact with the conductive member 14, which will be described later, based on the measurement results of the first and second voltmeters 28 and 30. The operation specifying means 36 for specifying the contact position and the change of the contact position (slide input) when contact with the conductive member 14 is confirmed, and the control signal corresponding to the operation specified by the operation specifying means 36 are illustrated. Control signal output means 38 for outputting to a vehicle window opening and closing device.

  In the touch switch 10 having such a structure, the operation surface 16 of the conductive member 14 is provided in the operation recess 40. The operation recess 40 is formed as an opening on the upper surface of the conductive member 14 and has an oblong shape that is long in the front-rear direction in plan view. Further, the operation recess 40 has a width dimension in the left-right direction larger than the width dimension of the distal end portion of the finger 44, and the distal end portion of the finger 44 can be easily inserted into the operation recess 40. As shown in FIG. 4, the bottom of the operation recess 40 has a central portion in the front-rear direction extending linearly in the front-rear direction, and both end portions in the front-rear direction are directed upward in the front-rear direction. The curved shape is inclined. Further, as shown in FIG. 5, the bottom surface of the operation recess 40 has a curved shape that is inclined upward toward both sides in the left-right direction.

  The operation recess 40 is provided with a protrusion 42. The projecting portion 42 is a ridge having a width dimension in the left-right direction narrower than that of the operation recess 40 and linearly extending in the front-rear direction, and projects from the bottom surface of the operation recess 40 toward the opening side. Moreover, the protrusion height dimension of the protrusion part 42 is made smaller than the maximum depth dimension of the operation recess 40, and the protrusion part 42 is formed at a height that does not reach the opening of the operation recess 40. . In the present embodiment, the protrusion 42 is continuously formed over the entire length of the operation recess 40 in the front-rear direction.

  Further, the projecting tip surface of the projecting portion 42 is a flat surface extending in the front-rear direction with a predetermined width dimension, and the strip-like operation surface 16 extending in the front-rear direction is formed by the projecting tip surface of the projecting portion 42. In short, the operation surface 16 is provided in the operation recess 40, has a band shape narrower than the distal end portion of the finger 44, and is exposed to the outside through the opening of the operation recess 40.

  The operation surface 16 linearly extends in the front-rear direction with a predetermined width dimension: w that is narrower than the width dimension of the distal end portion of the finger 44 described later (see FIG. 3). Preferably, the width dimension w of the operation surface 16 is set in a range of 2 mm ≦ w ≦ 7 mm, and more preferably in a range of 3 mm ≦ w ≦ 6 mm. Particularly in this embodiment, w = 5 mm is set. If the width dimension: w of the operation surface 16 is set in the above range, the operation surface 16 can be made narrower than the width dimension of the distal end portion of the general adult finger 44 that is the main user. . However, the width dimension w of the operation surface 16 is set in consideration of the width dimension of the front end portion of the finger 44 of the main user, and the user is limited to a child whose finger 44 is thin, for example. In some cases, a narrower operation surface 16 may be employed.

As shown in FIG. 7, when the finger 44 is inserted into the operation recess 40 of the conductive member 14 and the fingertip contacts the operation surface 16, the conductive member 14 is grounded through the human body including the finger 44. Currents I ₁ and I ₂ flow through the conductive member 14 and the first and second detection resistors 24 and 26.

When currents I ₁ and I ₂ flow through the first and second detection resistors 24 and 26, the first and second detection resistors 24 and 26 in the first and second voltmeters 28 and 30. The voltage values Vm ₁ and Vm ₂ corresponding to the current flowing through are measured. And the contact confirmation means 34 of the processing apparatus 32 is the finger 44 (with respect to the electrically-conductive member 14) when each measured value: Vm1, Vm2 of the _1st , _2nd voltmeters 28 and 30 is more than a predetermined numerical value. The contact of the detected conductor) is detected. In addition, the contact confirmation means 34 determines whether the measured value of the 1st, 2nd voltmeters 28 and 30 is more than a preset threshold value, for example, Comprising: A measured value is more than a threshold value. Is determined, the contact of the finger 44 with the operation surface 16 of the conductive member 14 is detected. Further, the measurement of the voltage value: Vm ₁ by the first voltmeter 28 and the measurement of the voltage value: Vm ₂ by the second voltmeter 30 are executed sequentially, not simultaneously, and the measurement timing is slightly There is a great time difference.

When the contact of the finger 44 with the operation surface 16 of the conductive member 14 is detected, the operation specifying unit 36 of the processing device 32 causes the finger 44 to move based on the measurement values of the first and second voltmeters 28 and 30. The contact position with respect to the operation surface 16 is specified. That is, as shown in FIG. 7, when the finger 44 comes into contact with the intermediate portion of the conductive member 14 whose overall resistance value is R, the conductive member 14 as the resistor has one end (in FIG. 7). , The left end) to the contact position of the finger 44 (the resistance value is R ₁ ), and the second resistor 48 from the other end (the right end in FIG. 7) to the contact position of the finger 44. (The resistance value is substantially R ₂ ). These resistance value of the first resistor 46: the R _1, the resistance value of the second resistor 48: the ratio of R ₂ is, the distance from one end of the conductive member 14 to the contact position of the finger 44, the conductive Since the ratio of the distance from the other end of the member 14 to the contact position of the finger 44 is substantially the same, the contact position of the finger 44 with respect to the conductive member 14 is specified by determining the ratio of R ₁ and R _2. The FIG. 8 shows an electrical circuit diagram of the state in which the finger 44 is in contact with the conductive member 14.

  Note that the measurement of voltage values by the first and second voltmeters 28 and 30 is repeated at predetermined time intervals, and the operation specifying means 36 continuously detects changes in the contact position of the finger 44 with respect to the conductive member 14. doing. Thereby, when the tip part (fingertip) of the finger 44 is moved while being in contact with the surface (operation surface 16) of the conductive member 14, the displacement direction and the displacement amount of the finger 44 are specified.

  When the operation specifying unit 36 detects the contact position of the finger 44 or the movement while moving (slide input), the control signal output unit 38 of the processing device 32 detects the contact position of the finger 44 with respect to the operation surface 16 or the operation surface 16. A control signal corresponding to the amount of movement and the direction of movement while contacting the vehicle is output to the vehicle device. The device controlled by the operation of the touch switch 10 is not particularly limited, but in the present embodiment, for example, a vehicle window opening / closing device (not shown) is controlled, and the fingertip to the touch switch 10 is controlled. The opening / closing operation of the car window is executed in response to the slide input. In the present embodiment, by moving the finger 44 in the longitudinal direction of the operation recess 40 while making contact with the operation surface 16, the opening operation and the closing operation are performed according to the movement direction (left direction or right direction in FIG. 2). The operation is identified, and the opening / closing operation amount of the vehicle window is set according to the movement amount, and is output as a control signal from the control signal output means 38 to the opening / closing device of the vehicle window.

  In detecting the contact position of the tip of the finger 44 and the slide input, the touch switch 10 suppresses a change in the contact area of the finger 44 with respect to the operation surface 16.

  That is, the operation surface 16 has a band shape that is narrower than the tip portion of the finger 44 and extends in the front-rear direction. As a result, like the finger 44a indicated by the solid line in FIG. 8, the contact area of the fingertip with the operation surface 16 when pressed weakly against the operation surface 16, and the two-dot chain line in FIG. Like the finger 44b, the contact area of the fingertip with the operation surface 16 when it is strongly pressed against the operation surface 16 is substantially the same. Therefore, the change in the contact area due to the variation in the contact pressure of the finger 44 against the operation surface 16 at the time of input by the finger 44 can be suppressed. As a result, the variation in the contact area is suppressed and the variation in the measurement result is reduced when the first voltmeter 28 is measured and when the second voltmeter 30 is measured. Is planned.

  In particular, the width dimension w of the operation surface 16 is set to 5 mm, and is set to a range of 2 mm ≦ w ≦ 7 mm. Therefore, since the width dimension of the operation surface 16 is reduced with respect to the width dimension of the tip portion of a general adult finger 44, the change in the contact area of the finger 44 with the operation surface 16 is reduced. Detection accuracy is achieved.

  Further, the operation surface 16 is provided on the projecting tip surface of the projecting portion 42 projecting upward from the bottom surface of the operation recess 40. Therefore, even when the contact pressure of the finger 44 against the operation surface 16 increases and the finger 44 bulges out from the operation surface 16 to the outside in the width direction, the finger 44 moves to the operation surface of the conductive member 14. Contact with parts other than 16 is prevented, and erroneous operation is avoided.

  Further, the operation surface 16 extends linearly in the front-rear direction in plan view. Therefore, the slide input can be easily performed, and the tip of the finger 44 can be prevented from being detached from the operation surface 16 during the slide input.

  FIG. 9 shows a conductive member 50 constituting a touch switch as a second embodiment of the present invention. The conductive member 50 is formed of a conductive synthetic resin or the like, similar to the conductive member 14 shown in the first embodiment. In addition, in the following description, about the member and site | part substantially the same as the touch switch 10 of 1st Embodiment, description is abbreviate | omitted by attaching | subjecting the same code | symbol in a figure. In the touch switch of the present embodiment, portions not shown in the figure have substantially the same structure as the touch switch 10 of the first embodiment.

  That is, the conductive member 50 has a substantially rectangular plate shape, and a protrusion 52 is provided at an intermediate portion in the front-rear direction (the right-left direction in FIG. 9). The protruding portion 52 extends in the left-right direction (vertical direction in FIG. 9) while being curved in the front-rear direction with a substantially constant rectangular cross section, and is formed integrally with the conductive member 50. Further, the protruding portion 52 is narrower than the distal end portion of the finger 44 in the front-rear direction, and the protruding distal end surface is an operation surface 54.

  Even in the touch switch having the structure according to the present embodiment, the detection accuracy variation due to the change in the contact area of the finger 44 with respect to the operation surface 54 when the contact of the tip of the finger 44 with the operation surface 54 is input. And the input can be detected with high accuracy.

  In addition, since the operation surface 54 is formed using the tip end surface of the protruding portion 52 formed to protrude from the conductive member 50, an erroneous input due to the finger 44 coming into contact with another portion of the conductive member 50 during input. Is prevented. Therefore, the input operation intended by the user is accurately detected, and the intended operation is executed.

  As is clear from the touch switch of the present embodiment, the operation surface is not necessarily limited to the one extending in the front-rear direction of the vehicle, and may be provided so as to extend in a direction other than the front-rear direction such as the left-right direction. . In addition, the operation surface is not limited to a shape that extends linearly, and the shape shown in the present embodiment that extends while being curved, a shape that extends partially curved or curved, and the like are also employed. obtain.

  FIG. 10 shows a conductive member 60 and an insulating member 62 constituting a touch switch as a third embodiment of the present invention. The conductive member 60 is made of a conductive synthetic resin or the like, similar to the conductive member 14 shown in the first embodiment, and includes a protruding portion 64 that protrudes upward and extends in the front-rear direction. The protruding portion 64 is narrower than the tip end portion of the finger 44 in the left-right direction, and the protruding tip end surface is a flat operation surface 66 extending in the front-rear direction.

  An insulating member 62 is superimposed on the conductive member 60. The insulating member 62 is a member formed of an insulator such as a rubber elastic body or a synthetic resin, and has a sheet shape or a plate shape. Further, a cutout 68 corresponding to the protruding portion 64 is formed in the insulating member 62 so as to penetrate vertically.

  The insulating member 62 is overlapped with the portion of the conductive member 60 that is out of the projecting portion 64, the upper surface of the conductive member 60 is covered with the insulating member 62, and the operation surface 66 is the insulating member 62. It is exposed through the notch 68. As a result, the finger 44 is allowed to contact the operation surface 66 of the conductive member 60, and the insulation member 62 prevents the finger 44 from contacting other parts of the conductive member 60 (upper surface other than the operation surface 66). Further, conduction between the other part of the conductive member 60 and the finger 44 is prevented. In the present embodiment, the thickness dimension of the insulating member 62 is substantially the same as the projecting height dimension of the projecting portion 64, and the operation surface 66 and the upper surface of the insulating member 62 are located on substantially the same plane. .

  According to the touch switch having the structure according to this embodiment, the insulating member 62 covers the portion other than the operation surface 66 on the upper surface of the conductive member 60, and the insulating member 62 prevents contact with the finger 44. Has been. Thereby, an erroneous input caused by erroneously touching the finger 44 with a portion other than the operation surface 66 of the conductive member 60 is more effectively avoided, and only an input operation intended by the user can be detected.

  As mentioned above, although embodiment of this invention was explained in full detail, this invention is not limited by the specific description. For example, a structure in which a conductive member in a band shape narrower than a fingertip is disposed on a plate-like base (insulating member) formed of an insulator, and the entire upper surface of the conductive member is operated. May be configured.

  Further, the operation surface may be a cross shape, a radial shape, or the like in a plan view as long as each part has a long band shape.

  In the touch switch of the present invention, the operation surface may have a curved shape in which at least one end portion in the length direction is gradually inclined upward toward the outside in the length direction. According to this, since the end portion of the operation surface can be easily grasped by a change in tactile sensation at the time of slide input, visual confirmation can be omitted, and an input operation can be easily performed. It should be noted that curved portions inclined upward in the length direction may be provided on both sides of the operation surface in the length direction separately from the operation surface, for example, using the bottom surface of the operation recess 40. A curved portion may be provided.

  Further, in the touch switch according to the present invention, the decrease in detection accuracy due to the change in the contact area at the time of input is not only at the time of slide input in which the fingertip moves in the length direction on the operation surface, but also at the fingertip. Even when a touch input touches one point, it can be effectively avoided.

  Further, a thin insulator layer may be formed on the surface of the conductive member 14 and the operation surface 16 may be covered with the insulator. In this case, direct contact between the finger 44 and the conductive member 14 cannot occur, but by applying an alternating voltage, the insulator layer is made a dielectric and the finger 44 and the conductive member 14 are paired with a pair of electrodes. Therefore, by detecting a change in capacitance, the operation of the finger 44 can be detected as an input. In short, in the touch switch according to the present invention, the input detection method is not particularly limited. Note that an AC voltage may be applied to a touch switch having a structure having no insulator layer, and in that case, detection of a target slide input can be realized.

  Moreover, in the said embodiment, although the structure where the voltage was applied from two or more places (2 places) with respect to the electrically-conductive member 14 is shown, even if a voltage is applied to one place with respect to the electrically-conductive member 14, for example The change in the contact position of the fingertip can be detected based on the resistance change between the voltage application portion and the fingertip contact portion. Needless to say, the voltage may be applied from a plurality of three or more locations.

  In addition, for example, a conductive part that is grounded is provided on the armrest 12, and the input is detected by touching the operation surface 16 of the conductive member 14 with the index finger and performing sliding input while touching the conductive part with the thumb. May be. Thereby, the electrical resistance is reduced, and the detection accuracy can be improved and stabilized.

  Further, the touch switch of the present invention is not necessarily limited to the one provided on the armrest 12 of the door. Further, the touch switch of the present invention can be applied as an operation switch for audio, an air conditioner, etc., in addition to being employed as a window opening / closing switch. The apparatus which becomes is not specifically limited. Furthermore, the application range of the touch switch according to the present invention is not limited to automobiles, and can be suitably applied to, for example, motorcycles, railway vehicles, industrial vehicles, and the like.

10: Touch switch, 14, 50, 60: Conductive member, 16, 54, 66: Operation surface, 40: Operation recess, 42, 52, 64: Projection, 44: Finger

Claims (3)

In the touch switch that is applied with a voltage to the conductive member and detects the presence or absence of contact of the finger on the conductive member and the movement while in contact with the conductive member based on the energized state of the conductive member,
The conductive member has an operation recess that is wider than the tip of the finger, and a protrusion that protrudes from the bottom surface of the operation recess toward the opening. touch switch projecting distal end face, is a band shape extending in a predetermined width of the narrow width than the tip portion of the該手finger, characterized in that said finger is the operating surface of the conductive member contacting. The touch switch according to claim 1, wherein the operation surface has a strip shape extending linearly in a length direction in a plan view. The touch switch according to claim 1 or 2 , wherein a width dimension w of the operation surface is set in a range of 2 mm ≤ w ≤ 7 mm.

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