JP5909085B2 - Touch sensor - Google Patents

Description

  The present invention relates to a touch sensor that detects that a person has touched an electrode due to a change in capacitance of the electrode.

  For example, Patent Document 1 proposes a configuration in which various devices such as a vehicle air conditioner and an audio are controlled by a capacitive touch sensor. According to this configuration, the movement trajectory of the operator's finger is read by the touch sensor, it is determined to which operation pattern the movement trajectory matches, and various devices are controlled based on the operation content matching the operation pattern. Things have been done.

JP 2009-129171 A

  However, in the configuration proposed in Patent Document 1, it is necessary to take a large operation surface, a control circuit for storing the operation pattern is required, and the operator needs to store the operation pattern. . For this reason, there is a problem that an expensive apparatus is required and the operation is complicated, increasing the burden on the operator and cannot be easily installed as a general purpose.

  In particular, when a touch sensor is provided on the steering wheel of a vehicle, the installation area is small. Therefore, if a large operation unit is provided, this may interfere with the driver's steering operation. In addition, since the operation is performed while driving, it is difficult for the driver to move his / her finger greatly, and the operation is limited to simple operation operations. Therefore, a large operation device is provided so that various devices can be operated in various operation patterns. Less need to control.

  On the other hand, since it is necessary for the driver to perform a switch operation while driving the vehicle, it is desired to perform a quick process in accordance with the driver's intention without observing the operation surface of the touch sensor.

  The present invention has been made in view of the above circumstances, and the object of the present invention is that the illumination structure can be easily configured while keeping the contact sensitivity of the electrodes high, and the manufacturing cost can be kept low. It is to provide a touch sensor.

In order to achieve the above object, the invention according to claim 1
Detecting means for detecting that a plurality of electrodes are in contact and outputting a detection signal for each electrode;
In the touch type sensor provided with the contact determination means for determining which electrode is in contact or not in accordance with the detection signal,
Three of the electrode capacitance that Do different repeatedly arranged in the same order, the contact determination unit first contacts is a start electrode sensed electrode by an electrode in contact with the start electrode and the next is detected Provided with an operation input determination means for determining the operation direction according to the positional relationship ,
The operation input determination means is set when a contact to the start electrode is not detected and a contact to another electrode is detected after the electrode first detected to be contact is used as a start electrode. The start electrode is reset, and the electrode in which contact is detected next is set as a new start electrode, and the operation mode is determined by sequentially determining the positional relationship between the start electrode and the electrode in which contact is detected next. characterized in that the.

According to a second aspect of the invention, in the invention according to the first SL placement, the detection means, when the contact from the contact to start the electrodes is detected to the other electrode in a predetermined time is not detected, It is characterized in that contact detection in all the electrodes is invalidated, and when contact with the electrode is detected again thereafter, that electrode is used as a start electrode.

  According to the first aspect of the present invention, the electrodes of the same type are repeatedly arranged in the same order, and the electrode at which contact is first detected is used as the start electrode, and the position between the start electrode and the electrode at which contact is detected next is determined. Because the operation direction is determined by the relationship, the operation mode can be detected by the same operation regardless of which electrode is touched, and the operation according to the operator's intention can be performed without looking at the operation surface with a simple structure. It can be performed accurately and quickly. Since the control circuit for storing the operation pattern is not required and the operator does not need to store the operation pattern, the structure is simplified and the burden on the operator is reduced.

In addition, according to the first aspect of the present invention, it is possible to identify the electrode to be watched by changing the start electrode as needed, and to easily and quickly determine the moving direction of the operator's finger. Can be determined.

According to the second aspect of the present invention, when there is no contact with the other electrode for a predetermined time or more after contact with the start electrode, it is determined that the contact is not intended by the operator and the operation is canceled. Thus, inadvertent malfunction of the touch sensor can be prevented.

(A), (b) is a figure which shows the example of arrangement | positioning of the electrode of the touch-type sensor which concerns on this invention. It is a circuit block diagram of the touch-type sensor which concerns on this invention. (A), (b) is a figure which shows the output change at the time of the non-contact to the electrode of the touch-type sensor which concerns on this invention, and a contact. It is a flowchart which shows the flow of operation | movement of the touch-type sensor which concerns on this invention.

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

FIGS. 1A and 1B are diagrams showing examples of electrode arrangement of a touch sensor according to the present invention. The touch sensor 1 according to the present invention includes a mode selection switch 2 that is a mechanical push switch. As shown in FIG. 1 (a), three sets of three types of electrodes A, B, and C having different capacitances are arranged in the same order (from the bottom in the order of electrodes A, B, and C), for a total of nine pieces. It is arranged and configured. As another configuration, as shown in FIG. 1B, a total of seven electrodes A, B, and C having different capacitances are arranged in the same order (electrodes from the bottom) in the vicinity of the mode selection switch 2. You may arrange | position in the up-down direction in order of A, B, and C). Here, when the touch sensor 1 is installed on a steering wheel of a vehicle, for example, the mode selection switch 2 selects a control mode (audio mode, air conditioner mode, navigation mode, etc.) of a controlled device such as an audio system, an air conditioner, and a navigation system. In the audio mode, music selection and volume adjustment, in the air conditioner mode temperature and air volume adjustment, in the navigation mode menu selection, and the like are performed by operating the touch sensor 1.

  Next, a circuit configuration of the touch sensor 1 according to the present invention will be described below with reference to FIG.

FIG. 2 is a circuit configuration diagram of the touch sensor according to the present invention. The touch sensor 1 according to the present invention includes three types of electrodes A, B, and C having different capacitances and a periodic square wave. A microcomputer (microcomputer) 3 having a function as an oscillator which outputs an operation signal consisting of the above and inputs it to electrodes A, B and C via resistors R3, R5 and R9, and a DC power supply voltage Vcc are divided. Thus, the resistances R1 and R2 connected in series, the output voltage of each of the electrodes A, B and C and the potential (reference voltage) Va at the point a between the resistances R1 and R2 are compared to compare the electrodes A and B. , C is turned off if the output voltage is higher than the reference voltage Va, and a predetermined voltage is output. If the output voltages of the electrodes A, B, C are lower than the reference voltage Va , the output is turned on. Comparators 4, 5, and 6 that do not output voltage; Integration circuits 7, 8, 9, etc. for integrating the outputs of these comparators 4-6 are provided.

In the present embodiment, the electrostatic capacitance of the electrode A~C are set to be different each, the output from the electrode A~C is connected to separate input ports to each microcomputer 3 configuration Therefore, it may be determined which electrode A to C the input signal is by determining the input port. In that case, the electrodes A and B can be composed of the same electrode having the same capacitance.

The microcomputer 3 constitutes a control unit. The microcomputer 3 detects that the electrodes A, B, and C are in contact with each other, and is controlled according to the contact state with the electrodes A, B, and C. A control signal for controlling the apparatus is output. For this reason, the microcomputer 3 has contact determination means 3a for determining which electrodes A to C are in contact with each other according to the detection signal, and electrodes A, B, and C by the contact determination means 3a. when the contact is detected on the electrodes a, B, determines how many Re detection signals and C, the electrodes a, B, by contact order and the contact time and C, the operation input mode (in this embodiment Then, the operation input determining means 3c for determining the up operation or the down operation), the control mode determining means 3d for determining the operation input mode of the controlled device in accordance with the operation of the mode selection switch 2, and the operation input determining means 3c. And the operation input mode for the control function of the controlled device (audio, air conditioner, navigation system, etc.) determined by the control mode determination means 3d. There storage unit 3b which is stored are built.

The mode selection switch 2 is connected to the microcomputer 3 , and when the microcomputer 3 receives an input signal from the mode selection switch 2 , the contact determination means 3a contacts the electrodes A, B, and C. A permission unit 3e for permitting detection is provided. Therefore, the input signal from the mode selection switch 2 is input to the control mode determination unit 3d and the permission unit 3e, and the contact determination unit 3a contacts the electrodes A, B, and C according to the permission signal from the permission unit 3e. Detection is allowed. That is, the mode selection switch 2 is configured to serve as a contact detection activation switch. The outputs of the comparators 4 to 6 are connected to connection points b, c, d between the microcomputer 3 and the resistors R3, R5, R9 via resistors R4, R6, R10, respectively. That is, the output of each comparator 4-6 is connected to the microcomputer 3, and the square wave output of the microcomputer 3 and the pull-up power supply.

  Further, the function of the permission unit 3e may be provided to the contact determination unit 3c, and the contact determination unit 3c may be configured to start contact detection using a signal from the mode selection switch 2 as a trigger. Further, the microcomputer 3 itself may be put in a sleep state, and the microcomputer 3 may be activated by an input signal from the mode selection switch 2. In this case, the mode selection switch 2 serves as a start switch for the microcomputer 3.

  Next, the detection principle of the touch sensor 1 according to the present invention will be described below with reference to FIGS. 3 (a) and 3 (b).

  3 (a) and 3 (b) are diagrams showing changes in output when the touch sensor 1 according to the present invention is not in contact with the electrodes A, B, and C and when the electrodes are contacted. The operating voltage is distorted by the capacitance. For this reason, the output signals from the electrodes A to C are voltage signals having a waveform close to a sawtooth shape (shown as a complete triangular wave in FIG. 3) obtained by distorting a square wave input from the microcomputer 3.

  The comparators 4 to 6 output voltages only when the outputs (output signals) of the electrodes A to C are higher than the voltage (reference voltage) Va at the point a. Since the integration circuits 7 to 9 integrate the outputs of the comparators 4 to 6, the output rises substantially linearly with the passage of time, and the gradient thereof is the duty ratio of the outputs of the comparators 4 to 6 (the ON time). Proportion).

  Thus, the microcomputer 3 digitally converts the output voltages of the integration circuits 7 to 9 after 1 msec from the integration circuits 7 to 9 being integrated, and stores them in the storage unit 3b as the detection value Vm. Accordingly, the comparators 4 to 6, the integration circuits 7 to 9, and the microcomputer 3 function as a detection circuit that generates a detection value Vm corresponding to the difference between the output signals of the electrodes A to C and the reference voltage Va at the point a.

  When the operator's finger is not in contact with the electrodes A to C, the amplitude of the output signals of the electrodes A to C is relatively large as shown in FIG. ) Is relatively longer than the reference voltage Va. For this reason, the duty ratio of the output voltages of the comparators 4 to 6 is relatively large, the rising gradient of the output voltages of the integrating circuits 9 and 10 is relatively large, and the voltage after 1 msec is relatively high. The detected value Vm to be relatively increased.

  Then, the determination means 3a of the microcomputer 3 compares the detection value Vm with the threshold value So stored in the storage unit 3b in the microcomputer 3, and operates the electrodes A to C if the detection value Vm is equal to or greater than the threshold value So. It is determined that the person's finger is not in contact, and an OFF signal is output externally.

  On the other hand, when the operator's finger contacts the electrodes A to C, the capacitance of the electrodes A to C increases, and therefore the operator's finger does not contact the electrodes A to C as shown in FIG. In comparison with FIG. 3, the amplitudes of the output signals of the electrodes A to C become smaller as shown in FIG. For this reason, the time during which the output signals of the electrodes A to C are equal to or higher than the reference voltage Va is shortened, the duty ratio of the output voltages of the comparators 4 to 6 is reduced, and the rising gradient of the output voltage of the integrating circuits 7 to 9 is reduced. Since the voltage after 1 msec decreases, the detection value Vm acquired by the microcomputer 3 decreases.

  Then, the contact determination unit 3a of the microcomputer 3 compares the detection value Vm with the threshold value So stored in the storage unit 3b in the microcomputer 3, and when the detection value Vm becomes equal to or less than the threshold value So, the electrodes A to C are applied. It is determined that the operator's finger is in contact, and an ON signal is output externally.

  Next, the flow of the operation of the touch sensor 1 according to the present invention will be described with reference to FIG.

FIG. 4 is a flowchart showing the flow of the operation of the touch sensor. For example, in the touch sensor 1 installed on the steering wheel of the vehicle, when contact is detected by the contact determination means 3a provided in the microcomputer 3, The operation input determination means 3c uses the electrodes A, B, and C that are first detected as contacts as the start electrodes, the contact with the start electrodes A, B, and C is not detected, and the other electrodes B, C, and C When contact with A is detected, the start electrode is reset, and the electrodes B, C, and A with which contact is next detected are newly set as start electrodes, and electrode A with which contact is first detected with the start electrode , B and C are determined to determine the operation input mode.
Further, the microcomputer 3 first detects the contact of the electrode A (B, C), and when the contact with the other electrode B (C, A) is not detected within a predetermined time after the contact with the start electrode, When the contact detection on all the electrodes A, B, and C is invalidated and then the mode selection switch 3 is pushed and contact with the electrode A (B, C) is detected again, the electrode A (B, C) is used as a start electrode.

  That is, as shown in FIG. 4, when the operation of the touch sensor 1 is started (step S1), initialization is performed (step S2). First, it is determined whether or not the mode selection switch 2 is turned on by the driver. (Step S3). For example, it is further determined whether or not an audio mode, an air conditioner mode, or the like has been selected by the mode selection switch 2. For example, when the air conditioner mode is selected, the air volume, temperature, inside / outside air switching, and the like are switched by the mode selection switch 2. select.

  When the mode selection switch 2 is turned on by being pushed by the driver (when the determination result in step S3 is Yes), the active flag (flag indicating the mode selection switch ○ N / OFF) is changed to the ON mode. Then, detection of contact by the driver with the electrodes A, B, and C of the touch sensor 1 is started (step S5).

On the other hand, when the mode detection switch 2 is OFF because the mode selection switch 3 is not pushed by the driver (when the determination result in Step S3 is No), whether or not the active flag is in the ON mode. Is determined (step S6), and when the active flag is already set to the ON mode (when the determination result in step S6 is Yes), the nine electrodes A to C of the touch sensor 1 are applied. Detection of contact by the driver is started (step S5). On the other hand, when the active flag is set to the OFF mode (when the determination result in Step S6 is No), the process is performed because the mode selection switch 2 has not been pressed by the driver. Returns to step S2. That is, when the mode selection switch 3 is not pressed, the microcomputer 3 does not detect contact with the touch sensor 1 .

In detection of contact by the driver with the electrodes A, B, and C of the touch sensor 1, it is determined whether or not the driver's finger has touched any of the electrodes A, B, and C (for example, electrode A) ( step S7), and when the contact is detected (the determination in step S 7 is Yes), whether the next start electrode has been set is determined (step S8). When the start electrode has already been set (the determination result in step S8 is Yes), it is determined whether or not the opposite electrode (for example, electrode B or C) has been contacted (O) by the driver. (Step S9). In this case, for example, when the contact of the electrode B or C on the opposite side is not detected after the contact of the electrode A is detected, the setting of the electrode A as the start electrode is canceled (reset) when 400 msec elapses, and the electrodes A to C When contact is detected again, any of the detected electrodes A to C is set as a start electrode . If the start electrode has not been set yet (if the determination result in step S8 is No), the electrode (for example, electrodes B and C ) whose contact has been detected is set as the start electrode (step S10).

  When contact between the electrode (electrode A) where contact is first detected and the opposite electrode (electrodes B, C) is detected (when the determination result in step S9 is Yes), the electrode on the same side Whether A (B, C) is in a contact (ON) state, that is, for example, one electrode A is turned on after being turned on, and the other electrode B or C is turned on, but the electrode A is also turned on. Alternatively, it is determined whether the electrodes A, B, and C are simultaneously contacted (ON) (whether or not they are simultaneously pressed) (step S11). When both electrodes A, B, and C are in the contact (ON) state at the same time (when the determination result in step S11 is Yse), the direction of the operation by the driver is not fixed, so the output is turned off and the start The electrode setting is cancelled.

When the electrodes A (B, C) on the same side are not in the contact (ON) state (when the determination result in Step S11 is No), the electrode A is the start electrode and the electrode B is in contact (ON). If it is detected (if the driver's finger moves from electrode A to electrode B), the cursor moves in one direction, for example, in the upward direction (for example, when the air volume or temperature of the air conditioner is increased or mode is selected) If the electrode A is the start electrode and the contact (ON) of the electrode C is detected (if the driver's finger has moved from the electrode A to the electrode C), for example, the air conditioner In the air volume, temperature reduction, and mode selection, it is determined that the cursor moves in the other direction, for example, downward (step S12).

Similarly, when the electrode B is the start electrode and the contact (ON) of the electrode C is detected, it is determined that the electrode B is up (if the driver's finger moves from the electrode B to the electrode C). When the contact (ON) of the electrode A is detected at the start electrode (if the driver's finger is moving from the electrode B to the electrode A), it is determined that the electrode is down. Furthermore, if the electrode C is the start electrode and contact (ON) of the electrode A is detected (if the driver's finger has moved from the electrode C to the electrode A), it is determined to be up, and conversely the electrode C starts. When the contact (ON) of the electrode B is detected by the electrode (if the driver's finger has moved from the electrode C to the electrode B), it is determined to be down.

  Thereafter, the setting of the start electrode is reset (step S13), and the process returns to step S2. In this case, for example, when the driver moves the finger from electrode A to electrode B and then repeats the operation of moving the finger from electrode A to electrode B again, the OFF time when the finger is released is 70 msec. If it is less than that, the movement of the finger is determined as electrode A → electrode B, electrode B → electrode A, and when the OFF time is 70 msec or more, the movement of the finger is electrode A → electrode B, electrode A → electrode B. It is determined. If the ON state is maintained after the second electrode is turned ON, the second electrode may be moved up or down continuously in the determined operation direction. In this case, the scrolling speed may be gradually increased.

  On the other hand, when contact with the electrodes A to C is not detected even when the mode selection switch 2 is pressed (when the determination result in Step S7 is No), it is determined whether or not the start electrode has been set. When the start electrode is set (when the determination result at step S14 is Yes), it is determined whether or not the timer is operating (step S15). On the other hand, when the start electrode is not set (when the determination result in Step S14 is No), the process returns to Step S3.

  When the start electrode is set and the timer is operating (when the determination result in step S15 is Yes), it is determined whether or not a time of 70 msec or more has elapsed (step S16), and the timer is activated. If not (if the determination result in step S15 is No), a timer is started (step S17), and it is determined whether a time of 70 msec or more has elapsed (step S16).

  When the time of 70 msec or more has elapsed (when the determination result in Step S16 is Yes), the setting of the start electrode is reset (Step S18), and until the time of 70 msec or more has elapsed (the determination result in Step S16 is If no), the process returns to step S3.

  When the time of 70 msec or more has elapsed and the start electrode setting is reset (step S18), it is determined whether or not the time of 400 msec or more has elapsed (step S19), and when the time of 400 msec or more has elapsed (step S19). If the determination result in Step S19 is Yes), the active flag is reset (Step S20), and the process is performed until the time of 400 msec or more has elapsed (while the determination result in Step S19 is No). Return to S3.

  Thus, according to the touch sensor 1 of the present embodiment that operates as described above, the same type of electrodes A to C are repeatedly arranged in the same order, and an electrode (for example, electrode A) that is first contacted is detected. Is the start electrode, and the operation direction is determined by the positional relationship between the start electrode and the electrode (for example, electrode B or C) with which contact is detected next, so that any electrode A to C can be touched with the same operation. The operation mode can be detected, and the operation according to the driver's intention can be performed accurately and quickly with a simple structure and without viewing the operation surface. In addition to the need for a control circuit for storing the operation pattern, it is not necessary for the driver to store the operation pattern. This simplifies the structure and reduces the burden on the operator.

In addition, according to the touch sensor 1 according to the present embodiment, it is possible to identify the electrode to be watched by changing the start electrode as needed, and easily and quickly determine the direction of movement of the driver 's finger. Thus, the operation mode can be determined.

  Furthermore, in the touch sensor 1 according to the present embodiment, after contact with the electrodes A to C, when there is no contact with the electrodes A to C for a predetermined time or more, the contact is not intended by the driver. Therefore, the operation is canceled and the operation of the touch sensor 1 can be prevented from being inadvertently malfunctioned.

  In the above description, the touch sensor 1 according to the present invention is installed on the steering handle of the vehicle. However, the touch sensor 1 according to the present invention can be installed at any other part. is there.

1 Touch sensor 2 Mode selection switch 3 Microcomputer (control unit)
3a Microcomputer contact determination means 3b Microcomputer storage unit 3c Microcomputer operation input determination means 3d Microcomputer control mode determination means 4-6 Comparator 7-9 Integration circuit A-C Electrode

Claims (2)

Detecting means for detecting that a plurality of electrodes are in contact and outputting a detection signal for each electrode;
In the touch type sensor provided with the contact determination means for determining which electrode is in contact or not in accordance with the detection signal,
Three of the electrode capacitance that Do different repeatedly arranged in the same order, the contact determination unit first contacts is a start electrode sensed electrode by an electrode in contact with the start electrode and the next is detected Provided with an operation input determination means for determining the operation direction according to the positional relationship ,
The operation input determination means is set when a contact to the start electrode is not detected and a contact to another electrode is detected after the electrode first detected to be contact is used as a start electrode. The start electrode is reset, and the electrode in which contact is detected next is set as a new start electrode, and the operation mode is determined by sequentially determining the positional relationship between the start electrode and the electrode in which contact is detected next. A touch sensor characterized by that. The detection means invalidates contact detection in all electrodes when contact with other electrodes is not detected within a predetermined time after contact with the start electrode is detected, and thereafter contact with the electrodes is not performed. Once again detected touch sensor of claim 1 Symbol mounting, characterized in that the electrodes and the start electrode.

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