JP2012171607A - Operation control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an operation control device that prevents malfunction due to effects of external noise without using a special device.SOLUTION: The operation control device is configured to perform operation according to each state of a plurality of non-contact switches. The device includes: a parameter detection part for detecting a parameter regarding each state of the plurality of non-contact switches; an ON/OFF determination part for determining each ON/OFF state of the plurality of non-contact switches on the basis of the parameter detected by the state detection part; an operation part for performing the operation corresponding to the non-contact switch determined being in the ON state by the ON/OFF determination part; and a control part which controls so as to prevent the operation part from performing the operation corresponding to each non-contact switch in the ON state when at least two non-contact switches determined being in the ON state are included in the plurality of non-contact switches.

Description

  The present invention relates to an operation control apparatus that performs an operation according to an operation on a contactless switch, and more particularly to an operation control apparatus that can prevent malfunction due to the influence of external noise.

  In the capacitance type switch device disclosed in Patent Document 1, as shown in FIG. 7, adjacent capacitance type switches 1 (1A to 1F) are alternately connected to the input side plus terminal and the input side of the differential amplifier 10. Connected to the negative terminal. For this reason, even if each capacitance type switch outputs a noise signal due to the influence of external noise, the differential amplifier 10 removes the noise signal. As a result, the capacitance detection circuit 11 can detect only the detection signal output from the capacitance type switch without being affected by external noise. It is also common to use a metal shield or the like so that external noise is not superimposed on the output signal from the capacitive switch.

  Further, the input device shown in FIG. 8 includes a control circuit 18 that determines an on / off state based on a change in capacitance in the plurality of switch electrodes 13 to 16, and a switch that connects the switch electrode 13 and the control circuit 18. The wirings 21 to 24 and the switch wirings 21 to 24 are provided independently of the radio wave detection wirings 25 and 26 that are provided independently of each other and are connected to the control circuit 18. When the control circuit 18 detects the radio wave in the radio wave detection wirings 25 and 26, the control circuit 18 limits the detection of the on / off state. According to this input device, it is possible to reduce erroneous detection of ON / OFF when continuous jamming waves are generated.

JP 2006-222022 A

  The capacitance type switching device of Patent Document 1 described above includes a differential amplifier 10 for removing a noise signal. Further, the input device shown in FIG. 8 includes radio wave detection wirings 25 and 26 used to reduce erroneous detection due to jamming radio waves. As described above, each apparatus includes a special device as a countermeasure against malfunction caused by the influence of external noise. However, an increase in the number of devices constituting the apparatus is not desirable because the circuit scale increases and the cost increases. Therefore, it is desirable that malfunction due to the influence of external noise can be prevented without adding a special device.

  An object of the present invention is to provide an operation control apparatus that can prevent malfunction due to the influence of external noise without using a special device.

  The present invention is an operation control device that performs an operation according to each state of a plurality of contactless switches, a parameter detection unit that detects a parameter related to each state of the plurality of contactless switches, and the state detection unit An on / off determination unit that determines each on / off state of the plurality of contactless switches based on a parameter detected by the on / off unit, and an operation unit that performs an operation corresponding to the contactless switch determined to be on by the on / off determination unit When the plurality of contactless switches include at least two contactless switches that are determined to be in an ON state, the operation unit performs control so as not to perform an operation corresponding to each contactless switch in the ON state. And an operation control device including a control unit.

  In the operation control apparatus, the control unit includes a counting unit that counts the number of contactless switches that are determined to be in the ON state at the same time by the on / off determination unit.

  The present invention is an operation control device that performs an operation according to each state of a plurality of contactless switches, a parameter detection unit that detects a parameter related to each state of the plurality of contactless switches, and the state detection unit An on / off determination unit that determines each on / off state of the plurality of contactless switches based on a parameter detected by the on / off unit, and an operation unit that performs an operation corresponding to the contactless switch determined to be on by the on / off determination unit And when the value obtained by superimposing the parameters corresponding to the plurality of contactless switches detected by the parameter detection unit is equal to or greater than a threshold value, the operation unit does not perform the operation corresponding to the contactless switch in the ON state. And a control unit that controls the operation.

  In the operation control apparatus, the control unit includes a superimposing unit that superimposes each parameter corresponding to the plurality of contactless switches detected at the same point by the parameter detecting unit.

  In the operation control device, the contactless switch is a capacitive switch, and the parameter is a capacitance.

  In the operation control device, the contactless switch is an electromagnetic induction switch, and the parameter is a magnetic field.

  According to the operation control apparatus of the present invention, it is possible to prevent malfunction due to the influence of external noise without using a special device.

Front view of the car navigation apparatus of the first embodiment Rear view of printed circuit board on which switches 103a to 103d are arranged The block diagram which shows the internal structure of the control circuit of 1st Embodiment. The flowchart which shows operation | movement of the control circuit of 1st Embodiment. The block diagram which shows the internal structure of the control circuit of 2nd Embodiment. The flowchart which shows operation | movement of the control circuit of 2nd Embodiment. The figure which shows the circuit structure of the electrostatic capacitance type switch apparatus disclosed by patent document 1 The figure which shows the printed circuit board of the conventional input device

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the embodiments described below, a case where the operation control device according to the present invention is included in a car navigation device will be described as an example. The car navigation device is mounted on a vehicle and may be either a stationary type or a retrofit type. A car navigation device mounted on a vehicle receives external noise when the vehicle runs parallel to a truck or the like that is equipped with a radio and transmits radio waves.

(First embodiment)
FIG. 1 is a front view of the car navigation apparatus according to the first embodiment. As shown in FIG. 1, a display 101 that displays a map of the current location and its surroundings and an input unit 103 that is an input interface for a user to operate the car navigation device are provided on the front of the car navigation device. ing. In the example illustrated in FIG. 1, the input unit 103 includes four capacitive switches 103 a to 103 d. In these switches 103a to 103d, the capacitance changes according to the distance between the conductor such as the user's finger and the electrode of each switch. For example, when a conductor is close to or in contact with a switch, the capacitance at the switch increases. Note that the capacitance of each switch can be increased by the above-described external noise.

  FIG. 2 is a back view of the printed circuit board on which the switches 103a to 103d are arranged. The printed circuit board is provided inside the car navigation apparatus. As shown in FIG. 2, the printed circuit board 105 includes switches 103 a to 103 d, a control circuit 107 that operates according to the capacitance of each switch, and wirings 109 a to 109 d that connect the switches to the control circuit 107. Be placed. The switches 103a to 103d are arranged on the surface of the printed circuit board 105 with a predetermined interval.

  FIG. 3 is a block diagram illustrating an internal configuration of the control circuit according to the first embodiment. As shown in FIG. 3, the control circuit 107 of the first embodiment includes input terminals 111a to 111d, capacitance detection circuits 113a to 113d, on / off determination circuits 115a to 115d, a counter circuit 117, and a determination circuit. 119 and CPU 121. The input terminals 111a to 111d, the capacitance detection circuits 113a to 113d, and the on / off determination circuits 115a to 115d are provided in the same number as the switches 103a to 103d, respectively, and correspond to each switch on a one-to-one basis.

  Corresponding switches are connected to the input terminals 111a to 111d through wirings 109a to 109d. Capacitance detection circuits 113a to 113d detect a change in capacitance in the corresponding switch, and output a signal indicating an increase in the change amount as an analog voltage. The on / off determination circuits 115a to 115d determine the on / off state of the corresponding switch according to the comparison result between the voltage level of the output signal from the corresponding capacitance detection circuit and a predetermined threshold value. The threshold value can be changed. When the voltage level is less than the threshold value, the on / off determination circuits 115a to 115d determine that the corresponding switch is in an off state, and output a low (L) level digital signal. On / off determination circuits 115a to 115d determine that the corresponding switch is in an on state when the voltage level is equal to or higher than a threshold value, and output a high (H) level digital signal. The output signals of the on / off determination circuits 115 a to 115 d are input to the counter circuit 117 and the CPU 121.

  The counter circuit 117 counts the number of H-level digital signals input among the digital signals input from the on / off determination circuits 115a to 115d at the same time. The determination circuit 119 outputs a high (H) level digital signal when the number counted by the counter circuit 117 (hereinafter referred to as “count number”) is 2 or more, and low (L) when the count number is 0 or 1. ) Output a level digital signal.

  The CPU 121 appropriately determines whether the level of the output signal from the determination circuit 119 is high (H) or low (L). When the level of the output signal from the determination circuit 119 is high (H), the CPU 121 does not perform an operation according to the output signals of the on / off determination circuits 115a to 115d. That is, the CPU 121 invalidates the output signals of the on / off determination circuits 115a to 115d. On the other hand, when the level of the output signal from the determination circuit 119 is low (L), the CPU 121 performs an operation according to the output signals of the on / off determination circuits 115a to 115d.

  FIG. 4 is a flowchart showing the operation of the control circuit 107 according to the first embodiment. As shown in FIG. 4, the capacitance detection circuits 113a to 113d of the control circuit 107 detect the amount of change in capacitance in the corresponding switch (step S101). The capacitance detection circuits 113a to 113d output a signal indicating the increase in the change amount by an analog voltage. Next, the on / off determination circuits 115a to 115d determine the on / off state of the corresponding switch based on the voltage level of the output signal from the corresponding capacitance detection circuit (step S103). The on / off determination circuits 115a to 115d output a low (L) level digital signal when it is determined that the corresponding switch is in an off state, and a high (H) level digital signal when it is determined that the corresponding switch is in an on state. Is output.

  Next, the counter circuit 117 counts the number of input digital signals of H level among the digital signals input from the on / off determination circuits 115a to 115d at the same time (step S105). Next, the determination circuit 119 determines whether or not the count number counted by the counter circuit 117 is 2 or more (step S107). If the count number is 2 or more (count number ≧ 2), the process proceeds to step S109. If the count number is less than 2 (count number <2), the process proceeds to step S111. In step S109, the CPU 121 invalidates the output signals of the on / off determination circuits 115a to 115d and does not perform an operation according to the output signal. On the other hand, in step S111, the CPU 121 performs an operation according to the output signals of the on / off determination circuits 115a to 115d.

  The above-described steps S101 to S105 are always performed, and steps S107 and S109 or S111 are appropriately performed.

  When the user operates the car navigation device of the present embodiment described above, the user touches one of the switches 103a to 103d with a finger. In this case, since there is only one switch whose increase in capacitance change is equal to or greater than the threshold value, the car navigation apparatus performs an operation corresponding to the switch.

  However, when the car navigation apparatus is affected by external noise, the switches 103a to 103d are arranged at predetermined intervals as shown in FIG. 2, but at least two switches are affected by external noise. receive. At this time, the increase in the amount of change in capacitance in at least two switches is equal to or greater than the threshold value. As described above, according to the car navigation device of the present embodiment, among the four switches 103 a to 103 d configuring the input unit 103, the increase in the amount of change in each capacitance in the plurality of switches is greater than or equal to the threshold value. In this case, the operation corresponding to the change in the capacitance of the four switches 103a to 103d is not performed.

  Therefore, the car navigation device of this embodiment does not malfunction due to the influence of external noise. Further, the prevention of malfunction due to the influence of the external noise can be realized only by changing the internal configuration of the control circuit 107 and the program for operating the CPU 121, and thus it is not necessary to use a special device.

(Second Embodiment)
The car navigation device of the second embodiment is different from the car navigation device of the first embodiment in the internal configuration and operation of a control circuit arranged on the printed circuit board. Except for this point, the second embodiment is the same as the first embodiment.

  FIG. 5 is a block diagram illustrating an internal configuration of a control circuit according to the second embodiment. In FIG. 5, the same or equivalent components as those of the control circuit 107 of the first embodiment shown in FIG. As shown in FIG. 5, the control circuit 207 of the second embodiment includes input terminals 111a to 111d, capacitance detection circuits 113a to 113d, on / off determination circuits 115a to 115d, a signal superimposing circuit 211, and a determination. A circuit 213 and a CPU 121 are included. The input terminals 111a to 111d, the capacitance detection circuits 113a to 113d, the on / off determination circuits 115a to 115d, and the CPU 121 are the same as those in the first embodiment. However, each output signal of the on / off determination circuits 115 a to 115 d is input only to the CPU 121.

  The signal superimposing circuit 211 superimposes and outputs each signal that is output at the same time from the electrostatic capacitance detection circuits 113a to 113d and that indicates the increase in the amount of change in electrostatic capacitance in the corresponding switch as an analog voltage. An output signal of the signal superimposing circuit 211 (hereinafter referred to as “superimposed signal”) is input to the determination circuit 213. The determination circuit 213 outputs a high (H) level digital signal when the voltage level of the superimposed signal is equal to or higher than a predetermined threshold value, and outputs a low (L) level digital signal when the voltage level is less than the threshold value. Output a signal.

  FIG. 6 is a flowchart showing the operation of the control circuit 207 of the second embodiment. As shown in FIG. 6, the capacitance detection circuits 113a to 113d of the control circuit 207 detect the amount of change in capacitance in the corresponding switch (step S201). The capacitance detection circuits 113a to 113d output a signal indicating the increase in the change amount by an analog voltage. Next, the signal superimposing circuit 211 superimposes and outputs the output signals of the capacitance detection circuits 113a to 113d (step S203).

  Next, the determination circuit 213 determines whether or not the voltage level of the output signal (superimposed signal) of the signal superimposing circuit 211 is equal to or higher than a threshold value (step S205). The process proceeds to S207, and if it is less than the threshold value, the process proceeds to step S209. In step S207, the CPU 121 invalidates the output signals of the on / off determination circuits 115a to 115d and does not perform an operation according to the output signal. On the other hand, in step S209, the CPU 121 performs an operation according to the output signals of the on / off determination circuits 115a to 115d.

  Note that step S201 and step S203 described above are always performed, and step S205, step S207, and S209 are performed as appropriate.

  Similarly to the first embodiment, the car navigation device according to the present embodiment does not malfunction due to the influence of external noise. Further, the prevention of malfunction due to the influence of the external noise is realized only by changing the internal configuration of the control circuit 207 and the program for operating the CPU 121, so that it is not necessary to use a special device.

  In the above embodiment, the four switches 103a to 103d constituting the input unit 103 provided on the front surface of the car navigation device have been described as capacitive switches. However, electromagnetic induction switches may be used. . In this case, the capacitance detection circuits 113a to 113d detect a change in the magnetic field in the corresponding switch, and output a signal indicating an increase in the change amount as an analog voltage.

  Further, the number of switches constituting the input unit 103 is not limited to four, but may be a plurality. Further, the capacitance detection circuits 113a to 113d may detect an absolute value of capacitance in the corresponding switch and output a signal indicating the absolute value as an analog voltage.

  The operation control device according to the present invention is useful as an operation control device such as a car navigation device having a contactless switch.

DESCRIPTION OF SYMBOLS 101 Display 103 Input part 103a-103d Switch 105 Printed circuit board 107,207 Control circuit 109a-109d Wiring 111a-111d Input terminal 113a-113d Capacitance detection circuit 115a-115d On-off determination circuit 117 Counter circuit 119,213 Determination circuit 121 CPU
211 Signal superposition circuit

Claims (6)

An operation control device that performs an operation according to each state of a plurality of contactless switches,
A parameter detector for detecting a parameter relating to each state of the plurality of contactless switches;
An on / off determination unit that determines each on / off state of the plurality of contactless switches based on the parameters detected by the state detection unit;
An operation unit that performs an operation corresponding to the contactless switch determined to be in the on state by the on / off determination unit;
When the plurality of contactless switches include at least two contactless switches determined to be in an on state, the control unit controls the operation unit not to perform an operation corresponding to each contactless switch in the on state. When,
An operation control device comprising: The operation control apparatus according to claim 1,
The operation control device according to claim 1, wherein the control unit includes a counting unit that counts the number of contactless switches that are determined to be on at the same time by the on / off determination unit. An operation control device that performs an operation according to each state of a plurality of contactless switches,
A parameter detector for detecting a parameter relating to each state of the plurality of contactless switches;
An on / off determination unit that determines each on / off state of the plurality of contactless switches based on the parameters detected by the state detection unit;
An operation unit that performs an operation corresponding to the contactless switch determined to be in the on state by the on / off determination unit;
Control that the operation unit does not perform the operation corresponding to the contactless switch in the on state when the value obtained by superimposing the parameters corresponding to the plurality of contactless switches detected by the parameter detection unit is equal to or greater than a threshold value A control unit,
An operation control device comprising: The operation control device according to claim 3,
The operation control device, wherein the control unit includes a superimposing unit that superimposes parameters corresponding to the plurality of contactless switches detected at the same time by the parameter detecting unit. The operation control device according to any one of claims 1 to 4,
The non-contact type switch is a capacitance type switch, and the parameter is a capacitance. The operation control device according to any one of claims 1 to 4,
The non-contact type switch is an electromagnetic induction type switch, and the parameter is a magnetic field.

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