JP2011085549A - Capacitance type proximity sensor device, capacitance type motion detector, and input device using them - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a capacitance type proximity sensor device having high detection sensitivity in both planar and height directions to a sensor part and having low directivity in a detecting direction. <P>SOLUTION: The capacitance type proximity sensor device comprises electrodes 13a-13d arranged in a reference plane so as to form capacitance between adjacent electrodes; a drive circuit 16 for outputting a drive voltage to be applied to an electrode to be a drive electrode among the electrodes 13a-13d; a detection circuit 17 for detecting a signal outputted from an electrode to be a detection electrode among the electrodes 13a-13d; a multiplexer 14 for connecting any one of the electrodes 13a-13d to be the derive electrode to the drive circuit 15 and any of the electrodes 13a-13d to be the detection electrode to the detection circuit 17; and a CPU 15 for computing the position of a body to be detected in a height direction perpendicular to the reference plane. The position of the body to be detected in triaxial directions is detected by sequentially changing over the drive electrode and the detection electrode among the electrodes 13a-13d by the multiplexer 14. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a capacitive proximity sensor device that detects the proximity of a detection object, a capacitive motion detection device that detects the operation of the detection object using the proximity sensor device, and an input device using them.

  Conventionally, as a device for detecting a detection target such as a human body, a capacitance type detection device that detects the approach of the detection target in a planar direction has been proposed (for example, see Patent Document 1). Such a capacitance-type detection device includes a plurality of electrodes arranged radially on the sensor surface so as to form a capacitance between the electrodes, and a pulse generation circuit that applies a pulse signal to each electrode.

  When detecting an object to be detected such as a human body, a pulse signal is applied to a plurality of electrodes arranged radially from a pulse generation circuit, and delayed from each electrode according to the capacitance formed between the electrodes. The output signal is detected by an arithmetic circuit. The arithmetic circuit detects the capacitance formed between the electrodes based on the signals output from the electrodes, and calculates the position of the detected object based on the detected change in the capacitance. The

  There has also been proposed a capacitance-type measuring device capable of detecting the distance of the detected object in the height direction with respect to the sensor surface in a predetermined medium (see, for example, Patent Document 2). Such a measuring apparatus uses two electrodes arranged at a predetermined interval so as to form a capacitance between the electrodes, and changes in the capacitance formed between the two electrodes. And an evaluation circuit for detecting the change of the displacement current in the inside.

  When detecting the detection object, a measuring device is installed in a predetermined medium in which the detection object exists, and a voltage is applied to the two electrodes. By applying this voltage, an electric field is formed between the two electrodes, and a displacement current is generated between the electrodes. When the detection target exists, the impedance of the displacement current changes according to the distance between the electrode and the detection target in the medium, and the displacement current flowing between the electrodes changes. By detecting the change in the displacement current by the evaluation circuit, the distance in the height direction between the detected object and the measuring device is detected.

JP-A-7-71908 JP 2005-518547 A

  However, in the capacitance type detection device described in Patent Document 1, the detection direction is limited to the plane direction, and it is difficult to detect the approach of the detection target with respect to the height direction of the sensor surface.

  Moreover, although the measuring apparatus described in Patent Document 2 can detect the detection target in the height direction, there is a problem that the detection accuracy of the distance of the detection target is low. In addition, since the proximity of the detection object is detected based on the capacitance formed between the two electrodes, there is a problem that directivity is generated in the detection sensitivity.

  The present invention has been made in view of the above points, and provides a capacitive proximity sensor device that has both high detection sensitivity in the planar direction and height direction with respect to the sensor unit, and has low directivity in the detection direction. With the goal.

  The capacitance-type proximity sensor device of the present invention is arranged in a reference plane so as to form a capacitance between adjacent electrodes, and is arranged so as to face one another in the X-axis direction belonging to the reference plane, and the reference pair A plurality of electrodes including the other electrode pair belonging to the surface and arranged opposite to each other in the Y-axis direction orthogonal to the X-axis direction, and a drive voltage applied to an electrode serving as a drive electrode among the plurality of electrodes A drive circuit for outputting, a detection circuit for detecting a signal output from an electrode serving as a detection electrode among the plurality of electrodes, an electrode serving as the drive electrode connected to the drive circuit, and an electrode serving as the detection electrode Switching means connected to the detection circuit; calculation means for calculating position information of the detected object in the X-axis direction, the Y-axis direction, and the Z-axis direction perpendicular to the reference plane from the detection result of the detection circuit; Detected in the Z-axis direction When detecting the position, the switching means connects the plurality of electrodes to the drive circuit and the detection circuit while sequentially switching an electrode serving as a drive electrode and an electrode serving as a detection electrode in the plurality of electrodes, When detecting the detected object position in the X-axis direction, the switching means connects the one electrode pair to the detection circuit, connects the other electrode pair to the drive circuit, and detects the detected position in the Y-axis direction. When the detection body is located at the detection position, the switching means connects the other electrode pair to the detection circuit, and connects the one electrode pair to the drive circuit.

  According to this configuration, the detected object is detected while switching the connection of the plurality of electrodes in the X-axis direction and the Y-axis direction belonging to the reference plane on which the plurality of electrodes are arranged, and the Z-axis direction perpendicular to the reference plane. Therefore, it is possible to detect the detection target in the planar direction and the height direction with respect to the sensor unit. In addition, since the detection electrode position is detected by sequentially switching the detection electrodes within the plurality of electrodes, the directivity in the detection direction can be reduced.

  According to the present invention, in the capacitive proximity sensor device, when the switching unit detects the position of the detection object in the Z-axis direction, the number of the drive electrodes is larger than the number of the detection electrodes. The plurality of electrodes are connected to the drive circuit and the detection circuit.

  According to this configuration, in the detection of the position of the detected object in the Z-axis direction, the detected object is detected using more drive electrodes than the detection electrodes, so that the electric field strength formed between the plurality of electrodes increases, and the reference The detection sensitivity in the height direction with respect to the surface is improved.

  According to the present invention, in the capacitance-type proximity sensor device, when the calculation unit detects the position of the detection target in the Z-axis direction, a signal output from each detection electrode switched by the switching unit. When the position of the detected object in the Z-axis direction is obtained by adding and averaging, and the detected object position in the X-axis direction is detected, the difference value of the output signals of the one electrode pair detected by the detection circuit is used. When the position of the detected object in the X-axis direction is obtained and the detected object position in the Y-axis direction is detected, the detected object position in the X-axis direction is determined from the difference value of the other electrode pair detected by the detection circuit. The position is obtained.

  According to this configuration, the detected object position is detected using the difference value between the pair of detection electrodes in the X-axis direction and the Y-axis direction, and from at least one detection electrode in the Z-axis direction. Since the calculation is performed based on the output signal, the approach of the detected object can be detected even in the detection region where the difference value between the output signals in the X-axis direction and the Y-axis direction is canceled. Thereby, the insensitive area | region of an electrostatic capacitance type proximity sensor apparatus can be supplemented. In addition, since the average of the signals output from the plurality of detection electrodes, in which the detected body position in the Z-axis direction is switched as the detection electrode in the plurality of electrodes, is calculated, the directivity in the detection direction can be reduced. it can.

  The capacitive proximity sensor device of the present invention is applied to at least three electrodes arranged in a reference plane so as to form a capacitance between adjacent electrodes, and an electrode serving as a drive electrode among the plurality of electrodes. A drive circuit that outputs a drive voltage, a detection circuit that detects a signal output from an electrode that is a detection electrode among the plurality of electrodes, and an electrode that is the drive electrode is connected to the drive circuit, and the detection electrode Switching means for connecting the electrode to the detection circuit, and calculation means for calculating the position in the height direction perpendicular to the reference plane of the detection object from the detection result of the detection circuit, the switching means The detection electrodes are sequentially switched in the plurality of electrodes so that the number of drive electrodes is larger than that of the detection electrodes.

  According to this configuration, the detected object is detected using more drive electrodes than the detection electrodes with respect to the height direction perpendicular to the reference plane on which the plurality of electrodes are arranged, and thus an electric field formed between the plurality of electrodes. It is possible to realize a capacitive proximity sensor device having increased strength and high detection sensitivity in the height direction with respect to the reference surface. In addition, the detection electrodes are sequentially switched and detected, so that signals are detected from the plurality of electrodes arranged in the reference plane and switched by the switching means. Therefore, an output signal obtained by detecting the detected object from a plurality of positions is used. Thus, the detection target can be detected, and the directivity in the detection direction can be reduced.

  The capacitance type motion detection device of the present invention processes the position information of the detected object calculated by the capacitance type proximity sensor device and the calculation circuit with a predetermined time constant, and the motion of the detected object is detected. And motion detection means for performing detection.

  According to this configuration, since the motion of the detected object can be detected with high detection sensitivity even in the height direction with respect to the reference surface, the three-dimensional motion of the detected object can be accurately detected.

  According to the present invention, in the capacitance type motion detection device, the motion detection means uses a predetermined time constant for position information of the detected object in the height direction perpendicular to the reference plane calculated by the arithmetic circuit. Processing, processing positional information of the detected object in the three axial directions with a predetermined time constant, and detecting a speed difference of the detected object approaching from a height direction perpendicular to the reference plane. .

  According to this configuration, since the distance of the detected object can be accurately measured according to the height direction distance with respect to the reference surface, the output signal is processed with a predetermined time constant so that the detected object approaches Speed can be detected.

  According to the present invention, in the capacitance type motion detection device, the motion detection unit detects a rotational motion including a Z-axis direction substantially orthogonal to a reference surface of the detection target.

  According to this configuration, since the distance in the three-dimensional direction of the detected object can be detected with high accuracy, the rotational motion of the detected object including the height direction perpendicular to the reference plane can be detected accurately.

  The input device of the present invention includes the above-described capacitance type motion detection device.

  According to this configuration, since the motion of the detected object can be accurately detected in the three-dimensional direction without being visually recognized by a camera or the like, an input device capable of obtaining an accurate input operation without being limited to the use environment. Can be realized. In addition, since motion in a three-dimensional direction can be applied to each input device, an input device with high input accuracy can be realized.

  The electrode driving method of the present invention is arranged in a reference plane so as to form a capacitance between adjacent electrodes, and belongs to the reference plane, with one electrode pair disposed facing the X-axis direction belonging to the reference plane, A drive circuit that outputs a drive voltage to be applied to an electrode serving as a drive electrode out of the plurality of electrodes, and a plurality of electrodes including the other electrode pair disposed opposite to each other in the Y-axis direction orthogonal to the X-axis direction And a detection circuit for detecting a signal output from an electrode serving as a detection electrode among the plurality of electrodes, and a detection result of the detection circuit on the X-axis direction, the Y-axis direction, and the reference plane of the detected object An electrode driving method in a capacitive proximity sensor device comprising: a calculating means for calculating position information in the vertical Z-axis direction, wherein the driving electrode is detected when detecting the position of the detected object in the Z-axis direction. Is greater than the number of the detection electrodes. As described above, when the plurality of electrodes are connected to the drive circuit and the detection circuit, the electrodes to be the detection electrodes are sequentially switched, and when the detected body position in the X-axis direction is detected, the switching means When the electrode pair is connected to the detection circuit, the other electrode pair is connected to the drive circuit, and the detected object in the Y-axis direction is located at the detection position, the switching means detects the other electrode pair. It is connected to a circuit, and the one electrode pair is connected to the drive circuit.

  According to this method, in the capacitive proximity sensor device in which a plurality of electrodes are arranged on the reference plane, a plurality of the X-axis direction and the Y-axis direction belonging to the reference plane, and a Z-axis direction perpendicular to the reference plane are included. Since the detected object is detected while switching the connection of the electrodes, it is possible to detect the detected object in the plane direction and the height direction with respect to the sensor unit. Further, in detecting the position of the detected object in the Z-axis direction, the detected object is detected using more drive electrodes than the detection electrodes, so that the electric field strength formed between the plurality of electrodes increases, and the height relative to the reference plane is increased. Direction detection sensitivity is improved. Furthermore, since the detection electrode position is detected by sequentially switching the detection electrodes within the plurality of electrodes, a capacitive proximity sensor device that can reduce the directivity in the detection direction can be realized.

  In the electrode driving method of the present invention, at least three of a plurality of electrodes arranged in a reference plane so as to form a capacitance between adjacent electrodes, and a driving voltage applied to an electrode serving as a driving electrode among the plurality of electrodes A drive circuit that outputs a signal, a detection circuit that detects a signal output from an electrode serving as a detection electrode among the plurality of electrodes, and a Z-axis direction perpendicular to the reference plane of the detection target from the detection result of the detection circuit And an electrode driving method in a capacitive proximity sensor device comprising a calculation means for calculating the position of the first electrode, wherein detection electrodes used for detection in a height direction perpendicular to the reference plane are sequentially placed between the plurality of electrodes. It is characterized by switching.

  According to this method, since the detection target is detected by switching the plurality of electrodes as the detection electrodes with respect to the height direction perpendicular to the reference plane on which the plurality of electrodes are arranged, the height direction with respect to the detection target reference plane It is possible to realize a capacitive proximity sensor device that can accurately detect position information of the detected object. In addition, the detection object is detected by using the output signals of a plurality of detection electrodes arranged in the reference plane by sequentially switching the detection electrodes, so that the detection of the detection object is arranged at a different position. It can be calculated from the output signal of the electrode, and directivity can be reduced in the detection direction.

  According to the present invention, it is possible to provide a capacitive proximity sensor device that has both high detection sensitivity in the planar direction and in the height direction with respect to the sensor unit and low directivity in the detection direction.

1 is a configuration diagram of a capacitive proximity sensor device according to an embodiment of the present invention. FIG. (A)-(c) is a figure which shows an example of electrode arrangement | positioning of the sensor part of the capacitive proximity sensor apparatus which concerns on embodiment of this invention. (A), (b) is a figure which shows the detection principle of the to-be-detected body of the X-axis direction of the electrostatic capacitance type proximity sensor apparatus which concerns on embodiment of this invention, and a Y-axis direction. It is a figure which shows the motion of the to-be-detected body of the electrostatic capacitance type proximity sensor apparatus which concerns on embodiment of this invention, and the change of an electrostatic capacitance. (A), (b) is a figure which shows the detection principle of the to-be-detected body of the Z-axis direction of the electrostatic capacitance type proximity sensor apparatus which concerns on embodiment of this invention. It is a flowchart which shows the electrode switching control of the electrostatic capacitance type proximity sensor apparatus which concerns on embodiment of this invention. (A), (b) is a figure which shows the correlation of the change of the Z-axis direction of the sensor part and to-be-detected body, and the magnitude | size of an output value in the electrostatic capacitance type proximity sensor apparatus which concerns on embodiment of this invention. is there. (A) is a figure which shows the waveform of the output signal of the double tap operation | movement in the electrostatic capacitance type motion detection apparatus which concerns on embodiment of this invention, (b) is the output at the time of performing the tap operation | movement from which speed differs. It is a figure which shows the waveform of a signal. (A) is a figure which shows the motion of the to-be-detected body with respect to the sensor part of the electrostatic capacitance type proximity sensor apparatus which concerns on embodiment of this invention, (b), (c) is XZ of the intensity | strength of an output signal. FIG. In the proximity sensor device according to the present embodiment, it is an XY plot diagram of the intensity of an output signal when a rotational motion is performed in the XY plane direction. (A), (b) is a figure which shows an example of the input device using the electrostatic capacitance type motion detection apparatus which concerns on embodiment of this invention. It is a figure which shows another example of the input device using the electrostatic capacitance type motion detection apparatus which concerns on embodiment of this invention. (A), (b) is a figure which shows another example of the input device using the electrostatic capacitance type motion detection apparatus which concerns on embodiment of this invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a configuration diagram of a capacitive proximity sensor device according to the present embodiment. As shown in the figure, the proximity sensor device according to this embodiment includes a sensor unit 11 that detects the proximity of the detected object, and the position of the detected object based on the output signal detected by the sensor unit 11. And a control circuit unit 12 for calculation.

  The sensor unit 11 includes four electrodes 13a to 13d arranged in the sensor surface 13 as a detection reference surface. Each electrode 13a-13d is arrange | positioned at predetermined intervals so that an electrostatic capacitance may be formed between each adjacent electrode. The electrodes 13a and 13d are arranged substantially parallel to the two opposing sides in the substantially rectangular sensor surface 13, and the other two opposing in the sensor surface 13 so as to be substantially orthogonal to the pair of electrodes 13a and 13d. A pair of electrodes 13b and 13c are arranged on the side.

  The control circuit unit 12 includes a multiplexer 14 serving as a switching unit for the electrodes 13a to 13d of the sensor unit 11, and a CPU 15 serving as a calculation unit that calculates the position of the detection target from the signals output from the electrodes 13a to 13d. Prepare. A drive circuit 16 is provided between the CPU 15 and the multiplexer 14 to apply a drive voltage to the electrodes 13a to 13d switched as drive electrodes. A detection circuit 17 is provided between the CPU 15 and the multiplexer 14 to detect output signals from the electrodes 13a to 13d switched as detection electrodes.

  The multiplexer 14 is connected to the electrodes 13 a to 13 d of the sensor unit 11 and is connected to the drive circuit 16 and the detection circuit 17, and switches the connection of the electrodes 13 a to 13 d to the drive circuit 16 and the detection circuit 17. The multiplexer 14 is connected to the CPU 15, and is configured to be able to switch and control connection of the electrodes 13 a to 13 d by a switching signal from the CPU 15. The multiplexer 14 connects electrodes 13a to 13d (hereinafter also simply referred to as drive electrodes) serving as drive electrodes to the drive circuit 16, and electrodes 13a to 13d (hereinafter also simply referred to as detection electrodes) serving as detection electrodes to the detection circuit. 17 is connected.

  The drive circuit 16 includes an oscillation circuit (not shown), and applies a drive voltage to the electrodes 13 a to 13 d serving as drive electrodes by the multiplexer 14. The timing of application of the drive voltage is controlled by the CPU 15.

  The detection circuit 17 is connected to the amplification circuits 18 connected to the electrodes 13 a to 13 d serving as detection electrodes via the multiplexer 14, and is connected to the amplification circuit 18. The amplified output signal is A / D converted and output to the CPU 15. The A / D converter 19 is provided.

  The amplification circuit 18 includes a positive terminal and a negative terminal, amplifies signals output from the electrodes 13 a to 13 d switched as detection electrodes by the multiplexer 14, and outputs the amplified signals to the A / D converter 19.

  In the present embodiment, the multiplexer 14 detects the detected object position in the X-axis direction included in the sensor surface 13 that is the detection reference surface and in the Y-axis direction orthogonal to the X-axis direction in the sensor surface 13. A pair of opposed electrodes 13a to 13d are connected to the amplifier circuit 18 as detection electrodes. In this case, one of the detection electrodes 13a to 13d is connected to the positive terminal of the amplifier circuit 18 and an output signal is input, and the other detection electrodes 13a to 13d are connected to the negative terminal and the output signal is input. . In the amplifying circuit 18, the input output signals of the pair of detection electrodes 13a to 13d are differentially amplified, and a difference value between the output signals is detected.

  Further, when detecting the position of the detected object in the height direction (Z-axis direction) orthogonal to the sensor surface 13, at least one of the electrodes 13 a to 13 d is connected to the amplifier circuit 18 as a detection electrode by the multiplexer 14. In this case, the detection electrodes 13a to 13d switched by the multiplexer 14 are connected to one terminal of the amplifier circuit 18 and an output signal is input, and the reference voltage is input to the other terminal. The amplifier circuit 18 amplifies the input output signal with a reference voltage.

  As described above, in the present embodiment, in one amplification circuit 18, the output signals from the detection electrodes 13a to 13d are amplified by the difference between the signals output from the pair of detection electrodes 13a to 13d according to the detection direction. Then, amplification according to the difference between the output signals of the detection electrodes 13a to 13d and the output signal of the reference signal is switched in a time division manner for amplification. Thus, detection in the X-axis direction, the Y-axis direction, and the Z-axis direction can be performed without providing the amplifier circuit 18 for each axis. Further, even when a difference value between the output signals of the pair of detection electrodes 13a to 13d used for detection in the X-axis direction and the Y-axis direction cannot be obtained, the detection target can be detected by detection in the Z-axis direction. It is possible to complement the insensitive area due to each amplification characteristic.

  The A / D converter 19 performs filtering processing and digital conversion on the output signal amplified by the amplifier circuit 18 and outputs the result to the CPU 15. A difference value or the like is detected from the output signal input to the CPU 15 by the CPU 15 as a detection circuit. The difference value may be detected by the A / D converter 19. Further, the CPU 15 as the calculation means calculates position information of the detected body in the three-axis directions using the detected output signal.

  Next, with reference to FIG. 2A to FIG. 2C, the electrode switching of the sensor unit 11 of the capacitive proximity sensor device according to the present embodiment will be described in detail. In the proximity sensor device according to the present embodiment, the multiplexer 14 switches the connection of the electrodes 13a to 13d arranged in the sensor unit 11 to the drive circuit or the detection circuit according to the detection direction, and switches the drive electrode and the detection electrode. The detected object is detected by. FIG. 2A is a diagram illustrating the switching of the electrodes 13a to 13d when detecting the detection target in the X-axis direction (the left-right direction on the paper surface). When detecting an object to be detected in the X-axis direction, the electrodes 13a and 13d disposed substantially parallel to the X-axis direction are switched as drive electrodes, and the electrodes 13b and 13c disposed substantially orthogonal to the X-axis direction are switched. Switch as detection electrode. The output signals of the detection electrodes 13b and 13c may be calculated by calculating the difference value of the absolute value of the output signal, or by calculating the difference value by inverting the sign of one of the output signals.

  FIG. 2B is a diagram illustrating switching of the detection electrodes when detecting the detection target in the Y-axis direction (up and down direction on the paper surface). When detecting an object to be detected in the Y-axis direction, the electrodes 13b and 13c disposed substantially parallel to the Y-axis direction are switched as drive electrodes, and the electrodes 13a and 13d disposed substantially orthogonal to the Y-axis direction are switched. Switch as detection electrode. Similar to the detection in the X-axis direction, the difference between the output signals of the detection electrodes 13a and 13d may be calculated by inverting the sign of one of the output signals.

  FIG. 2C is a diagram illustrating switching of the detection electrodes when detecting a detection body in the Z-axis direction (front of paper-depth direction). When detecting an object to be detected in the Z-axis direction, at least one of the electrodes 13a to 13d is switched as a detection electrode, and the remaining electrodes 13a to 13d are switched as drive electrodes. By performing detection in the Z-axis direction in this manner, a state in which a difference value between the output signals of the pair of detection electrodes 13a to 13d used for detection in the X-axis direction and the Y-axis direction cannot be obtained, for example, the center point P1 Even in a state in which the detected object is vertically moved up and down and the difference value between the X-axis direction and the Y-axis direction is not changed at 0, the operation of the detected object can be detected by detection in the Z-axis direction. The insensitive area due to each amplification characteristic can be complemented.

  Moreover, in this Embodiment, the electrode 13a is switched as a detection electrode among the four electrodes 13a-13d, and the remaining electrodes 13b-13d are switched as a drive electrode. In this way, by using the three drive electrodes 13b to 13d and applying a drive voltage from each of the drive electrodes 13b to 13d, the electric field strength formed between the electrodes 13a to 13d increases, so that the detection electrode 13a The output signal increases, and the detection sensitivity in the Z-axis direction can be improved. In the present embodiment, in detecting the detection object in the Z-axis direction, the electrodes may be switched so that the number of drive electrodes is larger than the number of detection electrodes. It is not necessary to switch all the electrodes 13b to 13d as drive electrodes.

  Further, in this embodiment, when detecting a detection object in the Z-axis direction, measurement is performed a plurality of times while sequentially switching the detection electrode between the electrodes 13a to 13d, and an average of the measured values of the respective output signals is calculated. Then, the detected object is detected. Thus, by detecting the detection electrodes while sequentially switching between the electrodes 13a to 13d, the directivity in the detection direction can be reduced in the detection of the detection target in the Z-axis direction. For example, when measuring only the electrode 13a as the detection electrode and the detection target, the detection electrode 13a located above the paper surface in FIG. 2C, the electrodes 13b and 13c located in the left-right direction on the paper surface, and the electrodes located below the paper surface Since the signal is output from the electrode 13a based on the capacitance formed between the electrode 13a and the electrode 13d, the detection sensitivity in the vicinity of the electrode 13a located above the paper surface is the highest, and the detection sensitivity in the vicinity of the electrode 13d below the paper surface is detected. Will decline. On the other hand, measurement is performed a plurality of times while switching the detection electrode between the electrodes 13a to 13d, and the average value of the output signal is calculated according to the number of times of measurement, whereby four directions in the sensor surface 13 of the sensor unit 11 are obtained. The detected object can be detected evenly, and the directivity of the detection sensitivity can be reduced.

  In the present embodiment, an example in which the electrodes 13a to 13d of the sensor unit 11 are arranged on the four sides of the substantially rectangular sensor surface 13 will be described. The arrangement of the electrodes 13a to 13d is, for example, a rhombus or Other arrangements such as a lattice shape may be adopted. As for the number of electrodes, it is sufficient that there are at least three electrodes 13a, 13b and 13c, and the upper limit of the number of electrodes is not particularly limited. For example, the electrodes may be arranged on three sides of the triangle. In this case, since the area where the difference value in the XY plane direction is canceled is reduced, it is preferable. Moreover, in this Embodiment, the detection sensitivity of a to-be-detected body can be improved, so that there are many numbers of electrodes.

  The electrodes 13a to 13d need only be arranged in a range where the detection reference plane can be formed by the capacitance formed between the electrodes, and need not necessarily be arranged in the same plane. For example, any of the electrodes 13a to 13d may be disposed on the upper side in the Z-axis direction relative to the sensor surface 13, and each electrode moves back and forth in the Z-axis direction with respect to the sensor surface 13. It may be arranged as follows.

Next, with reference to FIGS. 3A and 3B, the detection principle of the detection target in the X-axis direction and the Y-axis direction in the capacitive proximity sensor device according to the present embodiment will be described. As shown in FIG. 3A, in the detection in the X-axis direction and the Y-axis direction, the pair of electrodes 13a and 13d facing each other as the drive electrodes are switched, and the other pair of electrodes 13b and 13c facing each other are used as the detection electrodes. Switched. In this case, the driving electrodes 13a, electrostatic capacitance _{C x1} between the electrode 13d and the detection electrode 13b is formed, the driving electrodes 13a, electrostatic capacitance _{C x2} is formed between the electrode 13d and the detection electrode 13c. And the position of the hand as the to-be-detected body 31 is detectable by taking the difference of this electrostatic capacitance _Cx1 , _Cx2 . FIG. 3A shows a case where the position of the detection target 31 is detected when the detection target 31 moves in the X-axis direction.

FIG. 3B is a diagram illustrating an example of a detection principle when different electrode arrangements are employed in the capacitive proximity sensor device according to the present embodiment. The example shown in FIG. 3B is an example in which an electrode 13e as a drive electrode is arranged in the center, and electrodes 13f and 13g as detection electrodes are arranged on both sides thereof. In this case, the capacitance _{C 1} is formed between the electrode 13e and the electrode 13f, the electrostatic capacitance _{C 2} is formed between the electrode 13e and the electrode 13 g. The position of the detection target 31 can be detected by taking the difference between the capacitances C ₁ and C ₂ .

Furthermore, with reference to FIG. 3A and FIG. 4, the movement of the detection target 31 and the change in capacitance will be described. In the example shown in FIG. 3A, a capacitance C _x1 is formed between the detection electrode 13b and the drive electrodes 13a and 13d, and a capacitance is formed between the detection electrode 13c and the drive electrodes 13a and 13d. C _x2 is formed. When the detected body 31 moves in any direction of the X-axis direction (left-right direction), electric lines of force (not shown) formed between the electrodes 13a to 13d are absorbed by the detected body 31 and electrostatic capacity is detected. C _x1 and C _x2 change. For example, when the detection target 31 moves to the left side, the capacitance C _x1 increases and the capacitance C _x2 decreases. For this reason, when the detected body 31 moves in the X-axis direction (left-right direction), the difference in capacitance value (C _x2 -C _x1 ) is taken, and the amount of change in capacitance is shown in FIG. Thus, it becomes possible to detect the positional information and movement (motion) of the detected body 31 in the X-axis direction (left-right direction) of the detected body.

  When detecting the detection target in the Y-axis direction, the upper and lower electrodes 13a and 13d of the sensor unit 11 are used as detection electrodes, and the left and right electrodes 13b and 13c are used as drive electrodes. Thus, position information and motion of the detected object are detected.

Next, with reference to FIGS. 5A and 5B, the detection principle of the detection target in the Z-axis direction of the capacitive proximity sensor according to the present embodiment will be described. 5A and 5B are cross-sectional views taken along line AA of the sensor unit 11 illustrated in FIG. As shown in FIG. 5A, in this state, a capacitance C _X3 is formed between the detection electrode 13a and the drive electrode 13d (and drive electrodes 13b and 13c (not shown)), and an electric force is generated around the capacitance C _X3. A line 51 is formed.

As shown in FIG. 5A, when the distance in the Z-axis direction between the sensor surface 13 and the detected object 31 is large, the electric field lines 51 are absorbed by only a part of the detected object 31. Therefore, the capacitance C _X3 becomes small. On the other hand, as shown in FIG. 5B, when the distance between the sensor surface 13 and the detected body 31 is small, most of the electric lines of force 51 are absorbed by the detected body 31. _X3 increases. As described above, in the present embodiment, when the distance between the sensor surface 13 and the detection target 13 is small, the capacitance C _X3 decreases and the output signal of the electrode 13a as the detection electrode increases. When the distance between the sensor surface 13 and the object to be detected is large, the capacitance C _X3 increases and the output signal of the electrode 13a as the detection electrode decreases. As described above, in the present embodiment, it is possible to detect the distance between the sensor surface 13, the detected object 31, and the Z-axis direction.

In the present embodiment, the electric lines of force 51 formed between the electrode 13a switched as the detection electrode and the electrode 13d switched as the drive electrode during detection of the detection target 31 in the Z-axis direction are , It must not be symmetrical in cross-sectional view. That is, in the case where the distance of the detection object 31 with respect to the sensor surface 13 is constant, the detection object 31 is positioned more than the detection electrode 13a (when there is a hand on the left side of the paper) and the detection electrode 31d The capacitance C _X3 is different from when the hand is on the right side of the paper, and the magnitude of the output signal changes. For this reason, when only the electrode 13a is switched as the drive electrode to detect the detected body 31 in the Z-axis direction, a little directivity occurs in the detection direction. Therefore, in the present embodiment, when detecting the detected body 31 in the Z-axis direction with respect to the sensor unit 11, measurement is performed while sequentially switching the electrodes to be switched as the detection electrodes between the electrodes 13a to 13d as shown below. By doing so, the directivity of directivity in the detection direction is reduced. Hereinafter, the control flow of electrode switching used in the present embodiment will be described in detail with reference to FIG.

  FIG. 6 is a diagram illustrating an example of an electrode switching control flow of the capacitive proximity sensor device according to the present embodiment. As shown in FIG. 6, in the capacitive proximity sensor device according to the present embodiment, each of the electrodes 13a to 13d is used as a detection electrode and a drive electrode for each of the X-axis direction, the Y-axis direction, and the Z-axis direction. The position information of the detected body in the three-axis directions is detected by measuring the detected body four times while switching.

  In the flowchart shown in FIG. 6, the detection of the detection target is performed in the order of the X-axis direction, the Y-axis direction, and the Z-axis direction. First, detection of position information of the detection target in the X-axis direction is started, and the multiplexer 14 selects the electrodes 13a and 13d as detection electrodes and the electrodes 13b and 13c as drive electrodes (step S1). Next, the drive voltage is applied four times from the drive circuit 16 to the drive electrodes 13b and 13c. Next, the CPU 15 calculates the addition average of the signals output from the detection electrodes 13a and 13d, and calculates the position information of the detected object in the X-axis direction (step S2).

  Next, position information of the detected object in the Y-axis direction is detected. First, the multiplexer 14 switches the electrodes 13b and 13c as detection electrodes and the electrodes 13a and 13d as drive electrodes (step S3). Next, the drive voltage is applied four times from the drive circuit 16 to the drive electrodes 13a and 13d. Next, the CPU 15 calculates the addition average of the signals output from the detection electrodes 13b and 13c, and calculates the position information of the detected object in the Y-axis direction (step S4).

  Next, position information of the detected object in the Z-axis direction is detected. First, the multiplexer 14 switches the electrode 13a as a detection electrode, and switches the remaining electrodes 13b to 13d as drive electrodes. Next, a drive voltage is applied from the drive circuit 16 to the three drive electrodes 13b to 13d, and a signal is output from the detection electrode 13a (step S5). Next, the multiplexer 14 switches the electrode 13b as a detection electrode, and switches the remaining electrodes 13a, 13c, and 13d as drive electrodes. Next, a drive voltage is applied from the drive circuit 16 to the three drive electrodes 13a, 13c, and 13d, and a signal is output from the detection electrode 13b (step S6).

  Next, the multiplexer 14 switches the electrode 13c as a detection electrode, and switches the remaining electrodes 13a, 13b, and 13d as drive electrodes. Next, a drive voltage is applied from the drive circuit 16 to the three drive electrodes 13a, 13b, and 13d, and a signal is output from the detection electrode 13c (step S7). Next, the multiplexer 14 switches the electrode 13d as a detection electrode, and switches the remaining electrodes 13a to 13c as drive electrodes. Next, a drive voltage is applied from the drive circuit 16 to the electrodes 13a to 13c, and a signal is output from the detection electrode 13d (step S8). Finally, the CPU 15 calculates the average of the signals output from the electrodes 13a to 13d used as the detection electrodes during steps S5 to S8, and calculates the position information of the detection target in the Z-axis direction ( Step S9). As described above, after detecting the detected object four times in each of the three axis directions, the detected object is detected again in order from the X axis direction (step S1 again).

  In the present embodiment, the detection target is measured four times in each of the three axial directions. Thus, the detection sensitivity of the detection target can be improved by measuring four times in each axial direction and calculating the addition average of the output signals in each axial direction. In particular, in the present embodiment, in the detection in the Z-axis direction, each of the electrodes 13a to 13d is detected at least once as a detection electrode, so that the detected object in the Z-axis direction can approach from any direction. , Can be detected with equal sensitivity. In the present embodiment, only one detection electrode is used for the detection body in the Z-axis direction, but a plurality of electrodes 13a to 13d are switched to the detection electrode used for detection in the Z-axis direction. May be used. Among these, from the viewpoint of improving the detection sensitivity, for the detection in the Z-axis direction, the electrodes 13a to 13d having the same number or more as the electrodes 13a to 13d used as the drive voltage in the detection in the Z-axis direction are switched and used. Is preferred.

  Next, the operation of the capacitive proximity sensor device according to the present embodiment configured as described above will be described with reference to FIG. 1 again. First, the multiplexer 14 switches arbitrary electrodes 13a to 13d as drive electrodes and detection electrodes according to the detection direction. Next, the drive voltage whose timing is controlled by the CPU 15 is applied from the drive circuit 16 to the drive electrodes. A signal corresponding to the capacitance is output from the detection electrode by the drive voltage applied to the drive electrode. The signal output from the detection electrode is input to the detection circuit 17 and input to the amplification circuit 18 to be amplified. The amplified output signal is filtered and A / D converted by the A / D converter 19 and input to the CPU 15. The CPU 15 detects the position information and operation of the detection target based on the input output signal. As described above, in the proximity sensor device according to the present embodiment, the position information and the operation of the detected object are detected based on the capacitance of the sensor unit 11 generated by the approach of the detected object.

  Here, the inventors examined in detail the correlation between the distance in the Z-axis direction of the detected object and the output value from the detection electrode in the capacitive proximity sensor device according to the present embodiment. As a result, it was found that the proximity sensor device according to the present embodiment has particularly good linearity between the distance between the detected object and the sensor and the logarithm of the output value. Hereinafter, the contents investigated by the present inventors will be described in detail with reference to FIGS. 7 (a) and 7 (b).

  As shown in FIG. 7 (a), the capacitive proximity sensor device according to the present embodiment is particularly effective when the ratio of the sensor surface-detected object distance / electrode spacing is approximately 1.5 or less. The proximity of the detection target can be detected. Here, the electrode spacing is the average value of the distance between the electrodes 13a and 13d facing each other in the electrode arrangement as shown in FIG. 1 and the distance between the electrodes 13c and 13b. The distance was 10 cm. In particular, as shown in FIG. 7 (b), in the range where the ratio of the sensor surface-detected object distance / electrode interval is 1 or less, the ratio of the distance between the detected object and the sensor surface and the electrode interval is taken as the X axis, When the logarithm of the output value is plotted on the Y axis, the correlation coefficient between the distance and the output value is 0.9997, which indicates that the linearity is extremely high. In other words, in the present embodiment, the distance between the sensor surface and the object to be detected can be sufficiently measured up to about 15 cm, and the distance can be measured with very good linearity within the range of 10 cm or less.

  Thus, the capacitive proximity sensor device according to the present embodiment can detect the detection target 31 with particularly high accuracy in the Z-axis direction. Thereby, the capacitive proximity sensor device according to the present embodiment can also be used as a distance measuring device. Usually, in the capacitive proximity sensor device, when the size of the detection target 31 to be detected is different, the signal intensity is blurred, and it is difficult to accurately measure the distance. On the other hand, the proximity sensor according to the present embodiment can reduce the directivity of the detection direction of the detection object in the Z-axis direction with respect to the sensor unit 11 by performing the electrode switching control as described above. In particular, in the present embodiment, since the distance between the detected object and the sensor surface 13 can be detected with high accuracy within the range surrounded by the electrodes 13a to 13d of the sensor unit 11, the accurate position of the detected object is determined. It is possible to accurately detect the information and the proximity direction of the detection target.

  Next, an application example of the proximity sensor device according to the present embodiment will be described. Since the proximity sensor device according to the present embodiment can accurately detect the position information of the detected object in the three-axis directions, the position information of the detected object detected by the CPU 15 is used as a predetermined time constant. By using in combination with the motion detection means that is processed in the above, it can be applied to a motion detection device and various input devices capable of detecting various motions in the three-dimensional direction of the detected object. Hereinafter, with reference to FIGS. 8 to 10, various motion detection devices using the capacitive proximity sensor device according to the present embodiment will be described.

  With reference to FIGS. 8A and 8B, an example of motion that can be detected by the motion detection apparatus according to the present embodiment will be described. 8 (a) and 8 (b) show the detected object 31 as a sensor surface with respect to the sensor surface 13 of the capacitive proximity sensor device according to the present embodiment shown in FIGS. 5 (a) and 5 (b). It is a figure which shows the waveform of the output signal from the sensor part 11 with respect to elapsed time when it moves up and down with respect to 13 height directions (Z-axis direction). 8A and 8B, the position information of the detected object is measured four times for each axis of XYZ every 10 ms, and the average is calculated.

  In the example shown in FIG. 8A, when the detected body 31 is moved up and down twice in the height direction with respect to the sensor surface 13 (hereinafter, the operation of moving up and down in the height direction is called a tap. 2 is a change in the signal strength of the output signal. As shown in FIG. 8A, the capacitive proximity sensor device according to the present embodiment has no directivity in the detection direction with respect to the height direction and has high detection sensitivity. However, it can be seen that two peaks occur in the waveform of the signal strength of the output signal, and the double tap operation can be detected with high accuracy. It can also be seen that even when the double tap operation is repeated three times, two peaks occur in the waveform of each output signal, and the double tap operation can be detected with good reproducibility. From these results, it can be seen that the capacitive proximity sensor device according to the present embodiment can detect the tap operation with high accuracy and can be applied to an input device using the double tap operation for the input operation.

  FIG. 8B shows a change with time of the waveform of the output signal when the proximity sensor according to the present embodiment is tapped at different speeds. As shown in FIG. 8B, in the proximity sensor according to the present embodiment, the waveform of the output signal when the tap operation is performed at a relatively high speed (three on the left side in the figure) has a small half-value width and is sharp. It turns out that it becomes a peak. On the other hand, the waveform of the output signal when the tap operation is performed at a relatively slow speed (the two on the right side in the figure) is broader than that when the tap operation is performed at a relatively high speed. I understand that. In addition, when comparing the reproducibility of the waveform when the tap operation is repeated at a relatively high speed and the waveform when the tap operation is repeated at a relatively low speed, a waveform with a constant shape is obtained with good reproducibility. You can see that As described above, the proximity sensor device according to the present embodiment can identify the speed of the tap operation with the waveform of the output signal with high reproducibility, and thus can be applied to an input device using the difference in the speed of the tap operation for the input operation. I understand that.

  In order to determine the double tap operation illustrated in FIG. 8A and the tap operation illustrated in FIG. 8B, for example, the following determination may be performed. If the output signal falls to a level before the peak starts within 1000 ms from the first peak, and falls or stagnates for more than 300 ms from the first peak, it is determined as a single tap. In addition, when the first peak falls within 300 ms and then rises again, the next peak appears within 600 ms from the first peak, and drops to the level before the peak starts within 1000 ms from the first peak. to decide.

  Next, another example of motion that can be detected by the motion detection device according to the present embodiment will be described with reference to FIGS. FIG. 9A is a diagram illustrating how the detection target 31 is moved with respect to the sensor unit 91, and FIGS. 9B and 9C are diagrams illustrating the sensor unit 91 with respect to the sensor unit 91. FIG. 6 is an XZ plot diagram of the intensity of an output signal when a circular motion of a predetermined size in the XY plane is performed at two positions where the distance in the Z-axis direction is different from the detected object 31; The output value in the X-axis direction is plotted on the axis, and the output value in the Z-axis direction is plotted on the vertical axis.

  In FIG. 9B, it can be seen that the distance between the sensor unit 91 and the detection target 31 is about 3 to 4 cm, and in this case, the average level of the output signal is about 240. On the other hand, as shown in FIG. 9C, when the distance between the sensor unit 91 and the detection target 31 is as large as 8 to 10 cm, the average level of the output signal is about 160. It can also be seen that the change in the output value in the X-axis direction is small. From these results, in the motion detection device according to the present embodiment, at least two types of rotation operations in the XY plane having different distances between the detected object 31 and the sensor unit 91 are subjected to two types having different signal strengths. It can be seen that the rotational motion of can be identified as an input operation.

  At this time, further application is possible by simultaneously using information on the XY plane. With reference to FIG. 10, another application example using the capacitive proximity sensor device according to the present embodiment will be described. As described above, the capacitive proximity sensor device according to the present embodiment can detect the position information of the detection target in the three axial directions, and the signal strength of the output signal can be determined by the distance difference in the height direction. It is possible to detect a different output signal. By using this, it is possible to configure a motion detection device that can accept various inputs such as position, height, and rotation direction. Hereinafter, the principle will be described.

  FIG. 10 is an XY plot diagram of the intensity of the output signal when the proximity sensor device according to the present embodiment is rotated in the XY plane direction. The horizontal axis in FIG. 10 indicates the movement distance of the detection target 31 in the X-axis direction, and the vertical axis indicates the movement distance in the Y-axis direction. A curve L1 in FIG. 10 indicates the locus of the detection target 31 when the detection target 31 rotates in the XY plane with a small distance in the height direction with respect to the sensor unit 91. On the other hand, the curve L2 in FIG. 10 shows the locus of the detected body 31 when the detected body 31 rotates in the XY plane with respect to the sensor unit 91 under the condition that the distance in the height direction is large. As shown in FIG. 10, it can be seen that the curve L1 rotationally moved under the condition that the distance between the detection target 31 and the sensor unit 91 is small has a larger radius of rotation than the curve L2.

  In the capacitive proximity sensor device according to the present embodiment, the locus (curves L1, L2) of the detected object in the XY plane is detected with a predetermined time constant, and the position of each plot point in the XY plane. By detecting the information and the height in the Z-axis direction, and further converting each plot point to polar coordinates, the center point P1 of the rotational motion of the detected object on the sensor surface 13 can be detected. By judging this information together with the height information shown in FIG. 9, the rotational motion of the detected object can be detected at any position on the sensor surface, at any height and in any direction. Since it is possible to properly detect whether it has been performed, it is possible to perform various inputs with a single rotation operation. In addition, if it is only necessary to know that the rotation has been performed without detecting the position, the motion due to the rotational motion of the detected object can be performed without performing the calibration for setting the reference point of the motion detection at the start of detection. Can be detected. Thus, by automatically detecting the reference point, it can be used as an input device without performing calibration. For example, when another detected object enters the detection area, The reference point can be automatically calibrated even when the formed capacitance changes, which is particularly effective when used for an input device such as a remote controller.

  Next, with reference to FIGS. 11 to 13, an input device including the capacitive proximity sensor device according to the present embodiment will be described. FIGS. 11A and 11B are examples of an input device that combines a rotational motion and a proximity operation to the sensor unit. In the input device shown in FIGS. 11A and 11B, the display device 113 is disposed at the center of the sensor surface 112 on the rectangular sensor unit 111, and the electrodes 113 a to 113 d are disposed on the four sides of the sensor surface 112. It is an example. When an input operation is performed on the input device, the capacitance formed on the sensor surface 112 changes by moving the detection target 31 on the sensor surface 112. An input operation is performed by detecting a change in capacitance on the sensor surface 112.

  Next, a specific operation example of the input device shown in FIGS. 11A and 11B will be described. This input device displays a plurality of switchable icons on the screen of the display device 113, and is configured to be switchable according to the distance between the detected object 31 and the sensor surface 112. For example, as shown in FIG. 11A, when the distance between the detected object 31 and the sensor surface 112 (sensor unit 111) is far, icons of “function” and “search” are displayed. As shown in FIG. 11B, it is detected that the detected object 31 has approached the sensor surface 112, and icons of “time” and “calculator” are displayed. 11A and 11B, when a rotation operation of the detection target 31 is detected substantially parallel to the sensor surface in a state where any icon is displayed, which of the icons displayed on the display device 113 is detected. It is determined whether it has been selected, and the selected function is input. For this determination, the XY coordinates of the center of rotation may be calculated, and it may be determined which icon has been selected from a comparison between the coordinates and the position of the icon displayed on the display device 113. The direction may be made to correspond. It is also possible to perform other operations depending on the rotation direction. In this way, by simultaneously detecting the position, height, and direction of the rotation operation of the detection target 31, an input device capable of various input operations can be configured.

  In addition, it is possible to change the combination of the rotation operation and the height operation. In other words, this input device may be configured to display a plurality of switchable icons on the screen of the display device 113 and to switch the display by a rotating operation of the detected body 31 or the like. For example, as shown in FIGS. 11A and 11B, the display on the display device 113 is switched from “function” and “search” to “time” and “calculator” by rotating the detected object 31. Here, when the distance between the input device and the detection target 31 is substantially constant, the signal intensity is also substantially constant, so that only display switching is performed. Next, in a state where the icons of “time” and “calculator” are displayed, the detected object 31 is brought closer to the sensor surface 112 as shown in FIG. Due to the proximity operation of the detection target 31, the output signal detected by the capacitive proximity sensor device provided in the input device increases. Here, by providing a certain threshold for the signal output, a change in signal intensity due to the proximity of the detected object 31 can be recognized as an input operation, and the detected object 31 does not contact the sensor surface 112 of the input device. An input device capable of selecting the icons of “time” and “calculator” can be configured.

  Next, another example of the input device using the capacitive proximity sensor according to the present embodiment will be described with reference to FIG. FIG. 12 shows a configuration of an input device that combines a rotation operation (direction) of the detection target 31 with respect to the sensor unit 121 and a proximity operation of the detection target 31. As described above, the capacitive proximity sensor device according to the present embodiment can specify the rotation direction on the sensor unit 121. By using this, the selection order of the selection list can be changed between right rotation and left rotation according to the rotation direction of the detection target 31 on the sensor unit 121, thereby detecting the detection target on the sensor unit 121. An input device using the rotation direction of 31 can be configured. The input operation can be performed by bringing the detected object 31 closer to the sensor unit 121 as in the example shown in FIGS.

  Next, with reference to FIGS. 13A and 13B, another application example of the input device using the capacitive proximity sensor device according to the present embodiment will be described. The example shown in FIG. 13A is a schematic diagram of an input device using a rotational motion including the height direction of a detection object such as the detection object 31. In the input device illustrated in FIG. 13A, it is possible to detect a rotational motion in a three-dimensional direction including the height direction of the detection target 31 with the sensor unit 131 and perform an input operation. As described above, since the motion detection device according to the present embodiment has high detection accuracy with respect to the motion in the height direction, it is possible to configure such an input device.

  FIG. 13B is an example showing an actual measurement value of the output signal detected by the input device of FIG. The example shown in FIG. 13B is an actual measurement value of the output signal on the YZ plane, and the horizontal axis represents the distance in the Y-axis direction from the center of the sensor surface 131 calculated from the magnitude of the output value in the Y-axis direction. The vertical axis indicates the magnitude of the output value corresponding to the distance in the height direction from the sensor unit 131. In this input device, as shown in FIG. 13A, when an input operation is performed by the detected object 31 in a region close to the sensor surface, the output value becomes large, and the input operation is performed in a region far from the sensor surface. Output value increases. In the example shown in FIG. 13B, the output value is about 320 in the region close to the sensor surface, the output signal can be clearly identified as about 100 in the region far from the sensor surface, and the displacement in the Y-axis direction is also detected. You can see that it is made.

  Since rotation detection including such a height direction can be performed, three types of rotations can be discriminated on the XY plane, the YZ plane, and the XZ plane, and six types of input can be performed when the rotation direction is included. . As a result, more various inputs are possible. For example, in the input device as shown in FIGS. 11 and 12, it is possible to assign another operation to the rotation operation including the height direction. In a digital photo frame, it is possible to perform image feed, folder change, and enlargement / reduction operations only by a rotation operation by detecting a rotation operation with electrodes provided around the display unit. Similarly, in media players such as audio and moving images, fast forward / rewind, skip to the top of the media / moving to the next media, and folder change operations can be performed only by rotating operations. In addition, it is possible to perform input such as vertical scrolling and horizontal scrolling on a PC or the like by an intuitive operation.

  As described above, the proximity sensor device according to the present embodiment includes at least three electrodes arranged on the reference plane, and detects the object to be detected while switching the electrodes. It is possible to detect the position information and motion of the detection body in the three-axis directions with high accuracy. Further, since the rotational movement in the height direction can be used for the input operation in addition to the rotational movement in the plane direction, an input device capable of performing the input operation more reliably when used in the input device can be realized. .

  In particular, according to the input device according to the present embodiment, the detection sensitivity in the Z-axis direction can be improved, and the directivity in the detection direction can be reduced. Thereby, it is possible to accurately detect the distance to the detected object approaching the sensor unit 11 and the approach direction. On the other hand, for example, a proximity sensor using infrared rays or the like cannot accurately detect the distance of the detection target to the sensor unit. In addition, when detecting the proximity of the detected object by imaging the detected object using a camera or the like, in addition to the need for an illumination device, etc., the captured photo and video are flat, so the sensor is accurate. It was difficult to detect the distance between the part and the object to be detected. On the other hand, the input device using the proximity sensor according to the present embodiment detects a change in capacitance accompanying the approach of the detected object to the sensor unit, so that it is accurate without visually recognizing the detected object. A simple distance can be calculated. In addition, since the change in capacitance can be detected steplessly, the approach of the detected object from the Z-axis direction to the sensor unit can be accurately detected.

  The present invention is not limited to the embodiment described above, and can be implemented with various modifications. In the above embodiment, the case where four electrodes are used as the detection electrode and the drive electrode is described. However, the present invention is not limited to this, and a configuration in which at least one detection electrode and at least one drive electrode are used. Also good. Moreover, in the said embodiment, it is possible to change suitably about the right and left, upper and lower sides, front-depth distinction, the numerical value of a member, a position, a size, and a shape. Other modifications may be made as appropriate without departing from the scope of the object of the present invention.

  The present invention can be applied to various input devices such as a digital photo frame, a PC, and an audio operation panel.

11, 111, 121, 131 Sensor part 12 Control part 13, 112 Sensor surface 13a-13d, 113a-113d Electrode 14 Multiplexer 15 CPU
16 drive circuit 17 detection circuit 18 amplification circuit 19 A / D converter 31 detected object 113 display device

Claims (10)

One electrode pair disposed in the reference plane so as to form a capacitance between adjacent electrodes and disposed opposite to the X-axis direction belonging to the reference plane, and Y belonging to the reference plane and orthogonal to the X-axis direction A plurality of electrodes comprising the other electrode pair arranged opposite to each other in the axial direction;
A drive circuit for outputting a drive voltage to be applied to an electrode to be a drive electrode among the plurality of electrodes;
A detection circuit for detecting a signal output from an electrode serving as a detection electrode among the plurality of electrodes;
Switching means for connecting an electrode to be the drive electrode to the drive circuit, and connecting an electrode to be the detection electrode to the detection circuit;
Calculating means for calculating position information of the detected object in the X-axis direction, the Y-axis direction, and the Z-axis direction perpendicular to the reference plane from the detection result of the detection circuit;
When detecting the detected body position in the Z-axis direction, the switching means switches the plurality of electrodes to the driving circuit and the electrodes while sequentially switching an electrode to be a driving electrode and an electrode to be a detection electrode within the plurality of electrodes. Connected to the detection circuit;
When detecting the detected object position in the X-axis direction, the switching means connects the one electrode pair to the detection circuit, connects the other electrode pair to the drive circuit,
When the detected object in the Y-axis direction is in a detection position, the switching means connects the other electrode pair to the detection circuit and connects the one electrode pair to the drive circuit. Capacitive proximity sensor device.   The switching means connects the plurality of electrodes to the drive circuit and the detection circuit so that the number of the drive electrodes is larger than the number of the detection electrodes when detecting the detected object position in the Z-axis direction. The electrostatic capacity type proximity sensor device according to claim 1. When detecting the detected object position in the Z-axis direction, the arithmetic means adds and averages the signals output from the respective detection electrodes switched by the switching means to determine the position of the detected object in the Z-axis direction. Seeking
When detecting the detected body position in the X-axis direction, the position in the X-axis direction of the detected body is obtained from the difference value of the output signal of the one electrode pair detected by the detection circuit,
The position of the detected object in the X-axis direction is obtained from the difference value of the other electrode pair detected by the detection circuit when detecting the position of the detected object in the Y-axis direction. The capacitive proximity sensor device according to claim 2. At least three electrodes arranged in a reference plane so as to form a capacitance between adjacent electrodes;
A drive circuit for outputting a drive voltage to be applied to an electrode to be a drive electrode among the plurality of electrodes;
A detection circuit for detecting a signal output from an electrode serving as a detection electrode among the plurality of electrodes;
Switching means for connecting an electrode to be the drive electrode to the drive circuit, and connecting an electrode to be the detection electrode to the detection circuit;
Calculating means for calculating the position in the height direction perpendicular to the reference surface of the detection object from the detection result of the detection circuit,
The capacitive proximity sensor device characterized in that the switching means sequentially switches the detection electrodes within the plurality of electrodes so that the number of the drive electrodes is larger than that of the detection electrodes.   5. The capacitive proximity sensor device according to claim 1, and the position information of the detected object calculated by the calculation circuit are processed with a predetermined time constant, and the motion of the detected object is detected. A capacitance type motion detection apparatus comprising: a motion detection means for performing detection.   The motion detection means processes the position information of the detected object in the height direction perpendicular to the reference plane calculated by the calculation circuit with a predetermined time constant, and calculates the position information of the detected object in the three-axis directions. 6. The capacitance type motion detection apparatus according to claim 5, wherein processing is performed with a predetermined time constant, and a speed difference of the detected object approaching from a height direction perpendicular to the reference plane is detected.   The electrostatic capacity type motion detection device according to claim 5, wherein the motion detection unit detects a rotational motion including a height direction substantially orthogonal to a reference plane of a detection object.   An input device comprising the capacitive motion detection device according to any one of claims 5 to 7. One electrode pair disposed in the reference plane so as to form a capacitance between adjacent electrodes and disposed opposite to the X-axis direction belonging to the reference plane, and Y belonging to the reference plane and orthogonal to the X-axis direction A plurality of electrodes comprising the other electrode pair arranged opposite to each other in the axial direction;
A drive circuit for outputting a drive voltage to be applied to an electrode to be a drive electrode among the plurality of electrodes;
A detection circuit for detecting a signal output from an electrode serving as a detection electrode among the plurality of electrodes;
A capacitive proximity sensor device comprising: a calculation means for calculating position information of the detected object in the X-axis direction, the Y-axis direction, and the Z-axis direction perpendicular to the reference plane from the detection result of the detection circuit. An electrode driving method in
When detecting the detected object position in the Z-axis direction, the plurality of electrodes are connected to the drive circuit and the detection circuit so that the number of the drive electrodes is larger than the number of the detection electrodes, Switch the electrodes sequentially,
When detecting the detected object position in the X-axis direction, the switching means connects the one electrode pair to the detection circuit, connects the other electrode pair to the drive circuit,
When the detected object in the Y-axis direction is in a detection position, the switching means connects the other electrode pair to the detection circuit and connects the one electrode pair to the drive circuit. Driving method. At least three electrodes arranged in a reference plane so as to form a capacitance between adjacent electrodes, a drive circuit that outputs a drive voltage to be applied to an electrode to be a drive electrode among the plurality of electrodes, and A detection circuit for detecting a signal output from an electrode serving as a detection electrode among the plurality of electrodes, and a calculation means for calculating a position in a height direction perpendicular to the reference plane of the detected object from a detection result of the detection circuit; An electrode driving method in a capacitive proximity sensor device comprising:
An electrode driving method, wherein a detection electrode used for detection in a height direction orthogonal to the reference plane is sequentially switched between the plurality of electrodes.

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