JPWO2010053013A1 - Proximity sensor device and input assist device using the same - Google Patents

Abstract

To provide a capacitive proximity sensor device with high detection accuracy and an input assist device using the proximity sensor device. The sensor unit (1) includes detection electrodes (4) and (5) arranged so as to form capacitances between the drive electrode (3) for applying a drive voltage and the drive electrode (3). Composed. The output signal of the detection electrode (4) is input to the amplifier circuit (6), and the amplified output signal is input to the positive terminal of the differential amplifier circuit (8) having a positive terminal and a negative terminal. The output signal of the detection electrode (5) is input to the amplifier circuit (9), and the amplified output signal is input to the negative terminal of the differential amplifier circuit (8). The output signal amplified by the differential amplifier circuit (8) is subjected to filtering processing and digital conversion by the analog processing circuit (7), and input to the microcomputer (10). In the microcomputer (10), the difference value of the output signal is detected, and the proximity of the detected object is detected by comparing the detected difference value with a set threshold value.

Description

  The present invention relates to a capacitive proximity sensor device and an input assist device using the proximity sensor device.

  Various types of proximity detection devices for a detection target such as a human body have been proposed. For example, a capacitive proximity sensor device in which a detection electrode, a ground electrode, and a shielding electrode are arranged on an insulating substrate such as ceramics is known (see, for example, Patent Document 1).

  FIG. 9 (a) shows a schematic diagram of a capacitive proximity sensor device described in Patent Document 1. FIG. The sensor unit 90 includes a detection electrode 91 and a ground electrode 92 that are used for detecting a detection target, and a shielding electrode 93 that is used for shielding noise. The terminal of the detection electrode 91 and the terminal of the shield electrode 93 are connected to the oscillation circuit 95 via the shield wire 94, and the terminal of the ground electrode 92 is grounded.

  FIG. 9B shows the electrode arrangement of the sensor unit 90. The detection electrode 91 and the ground electrode 92 are arranged on one surface of the insulating substrate 97 so as to form a capacitance. A shield electrode 93 is disposed on the other surface of the insulating substrate 97 to reduce the influence of noise from the back surface of the detection electrode 91. When the detection object approaches the detection electrode 91, a part of the electric lines of force 98 formed between the detection electrode 91 and the ground electrode 92 is absorbed by the detection object, and the detection electrode 91 and the ground electrode 92 The capacitance between them decreases. The oscillation frequency oscillated from the oscillation circuit 95 changes based on a change in electrostatic capacitance between the detection electrode 91 and the ground electrode 92. The detection circuit unit 96 detects the change in the oscillation frequency as a voltage, and detects the proximity of the detected object by comparing the detected voltage with an arbitrary threshold value.

JP 2000-48694 A

  Such a capacitive proximity sensor device is required to have higher detection accuracy and to detect a minute change in capacitance. In order to improve the detection accuracy of the proximity sensor device, a method of amplifying the reception signal is common, but there is a problem that noise mixed in the reception signal is also amplified together. In the capacitive proximity sensor device of Patent Document 1, in order to reduce the influence of noise, a shielding electrode 93 is provided on the back surface of the detection electrode 91 to remove noise from the back surface. However, this method has a problem that noise from the front cannot be dealt with.

  The present invention has been made in view of this point, and an object thereof is to provide an electrostatic capacity type proximity sensor device with high detection accuracy and an input assist device using the proximity sensor device.

  The proximity sensor device of the present invention includes a drive electrode to which a drive voltage is applied, a pair of detection electrodes arranged to form capacitance between the drive electrode on both sides of the drive electrode, And a detection circuit for detecting a difference value between one output signal of the detection electrode and the other output signal.

  According to this configuration, one detection electrode and the other detection electrode are affected by the same noise, and the influence of the noise can be offset by detecting the difference value of the output signal of each detection electrode. , Detection accuracy can be improved.

  According to the present invention, in the proximity sensor device, the detection circuit detects a distance between the detection object and the detection electrode from the difference value. According to this configuration, when the difference value is a positive value, the output signal on one of the detection electrodes arranged on both sides of the drive electrode varies, and when the difference value is a negative value, the other detection electrode side Output signal fluctuates, the direction in which the detected object approaches the detection electrode can be determined based on the difference value, and the distance between the detected object and the detection electrode is detected from the magnitude of the absolute value of the difference value. be able to.

  In the proximity sensor device according to the present invention, the drive electrode has an annular shape, and the detection electrodes are arranged on both sides of the drive electrode. According to this configuration, the proximity of the detected object to the proximity sensor device from any direction can be detected.

  According to the present invention, in the proximity sensor device, the pair of detection electrodes have different electrode widths and / or distances from the drive electrodes, and static electrodes formed between the drive electrodes and the pair of detection electrodes, respectively. The distance between the electrodes and / or the electrode width is adjusted so that the electric capacities are the same.

  According to this configuration, the difference value of the capacitance when the detection object is not in proximity can be adjusted to be the same, and the calculation process for detecting the detection object can be simplified.

  An input auxiliary device according to the present invention includes an input device and a device main body including the proximity sensor device, and an auxiliary device that assists an input operation based on a signal output from the proximity sensor device. To do.

  According to the present invention, in the input assist device, the assist device turns on a lighting device for assisting a target input operation. According to this configuration, when an operator performs an input operation such as a switch in a dark place, the auxiliary lighting device is turned on by bringing a hand close to a predetermined range of the target switch, and the input operation can be assisted. .

  According to the present invention, in the input assist device, the assist device switches the assist operation to at least two stages according to the degree of proximity to the proximity sensor device. According to this configuration, the degree of approach can be fed back to the operator in stages, for example, by switching a plurality of lighting devices in stages according to the degree of approach.

  According to the present invention, it is possible to provide a capacitive proximity sensor device with high detection accuracy and an input assist device using the same.

It is a figure which shows the outline of a structure of the proximity sensor apparatus which concerns on embodiment of this invention. (a) Top view of electrode arrangement in the above embodiment, (b) Perspective view of FIG. 2 (a), (c) Cross-sectional view taken along line XX of FIG. 2 (a). It is a conceptual diagram explaining the detection principle of the to-be-detected body in the said embodiment. (a) The figure which shows the relationship of the position of the proximity sensor apparatus and to-be-detected body in this Embodiment, (b) It is a figure which shows the difference value of the electrostatic capacitance of the output signal in each point of Fig.4 (a). . (a) Top view of electrode arrangement in modification of the present invention, (b) A perspective view of FIG. 5 (a). It is a figure which shows the outline of a structure of the input auxiliary device which concerns on embodiment of this invention. (a) The figure which shows the application example using the proximity sensor apparatus of embodiment of this invention, (b) It is sectional drawing between YY of Fig.7 (a). It is a figure which shows the other application example using the proximity sensor apparatus of embodiment of this invention. (a) The figure which shows the outline of a structure of the electrostatic capacitance type proximity sensor of a prior art, (b) It is sectional drawing of the sensor part of Fig.9 (a).

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 shows a configuration diagram of a capacitive proximity sensor device according to an embodiment of the present invention. The proximity sensor device according to the present embodiment includes a sensor unit 1 that detects an object to be detected such as a hand and a control circuit unit 2 that processes an output signal from the sensor unit 1. The sensor unit 1 includes a drive electrode 3 to which a drive voltage is applied and detection electrodes 4 and 5 arranged so as to form a capacitance between the drive electrode 3 and the drive electrode 3.

  The output signal of one detection electrode 4 is input to the negative terminal of the amplifier circuit 6 having a positive terminal and a negative terminal. A reference voltage is applied from the analog processing circuit 7 to the positive terminal of the amplifier circuit 6. The output signal amplified by the amplifier circuit 6 is input to the positive terminal of the differential amplifier circuit 8 having a positive terminal and a negative terminal. The output signal of the other detection electrode 5 is input to the negative terminal of the amplifier circuit 9 having a positive terminal and a negative terminal. A reference voltage is applied from the analog processing circuit 7 to the positive terminal of the amplifier circuit 9. The output signal amplified by the amplifier circuit 9 is input to the negative terminal of the differential amplifier circuit 8. The output signals of the detection electrodes 4 and 5 amplified by the differential amplifier circuit 8 are filtered and digitally converted by the analog processing circuit 7 and input to the microcomputer 10, and the difference value is detected by the microcomputer 10 as the detection circuit. Is done. The approach of the detected object is detected by comparing the detected difference value with a set threshold value. The difference value may be detected by the analog processing circuit 7. Information on the detected object to be detected is sent to the external system via the interface 11. The drive voltage amplified by the amplifier circuit 13 is applied to the drive electrode 3 from the microcomputer 10 via the timing circuit 12. Application of the drive voltage is controlled by a timing circuit 12 instructed by a microcomputer.

  FIG. 2A shows a top view of the electrode arrangement in the sensor unit 1 of the present embodiment. The drive electrode 3, the detection electrode 4, and the detection electrode 5 formed in an annular shape are arranged concentrically on the insulating substrate 20. A detection electrode 4 is formed on the outer side of the drive electrode 3, and a detection electrode 5 is formed on the inner side. FIG. 2 (b) shows a perspective view of FIG. 2 (a). Capacitances are respectively formed between the drive electrode 3 formed in an annular shape and the detection electrodes 4 and 5. For this reason, if the hand 21 (hereinafter referred to as “detected object”) approaches within a predetermined range regardless of which direction it approaches, the electrostatic formed between the drive electrode 3 and each of the detection electrodes 4 and 5. The capacity changes. Based on the change of the capacitance value, the approach of the detection target 21 is detected.

  FIG. 2 (c) shows a cross-sectional view along the line XX of the sensor unit 1 shown in FIG. 2 (a). In the drawing, the electrode width of the detection electrode 4 is narrower than that of the detection electrode 5. This is for adjusting the capacitance formed between the drive electrode 3 and the detection electrodes 4 and 5, respectively. When the detection electrode 5 arranged on the inner side and the detection electrode 4 arranged on the outer side of the drive electrode 3 formed concentrically are compared, if the electrode width is the same, the detection electrode 5 is arranged inside the drive electrode 3. The area of the detection electrode 5 becomes smaller. Therefore, the capacitance formed between the drive electrode 3 and the detection electrode 5 is smaller than the capacitance formed between the drive electrode 3 and the detection electrode 4. For this reason, it is formed between the drive electrode 3 and each of the detection electrodes 4 and 5 by increasing the electrode width of the inner detection electrode 5 and arranging the distance between the drive electrodes 3 to be small. The capacitance is adjusted to be the same.

  3A to 3D are conceptual diagrams showing the detection principle of the proximity sensor device. FIG. 3A shows a cross section of the drive electrode 3, the detection electrode 4, and the detection electrode 5 disposed on the insulating substrate 20, and the lines of electric force 31 and the electrostatic capacitance Ca between the drive electrode 3 and the detection electrode 4. It is shown that the lines of electric force 32 and the electrostatic capacitance Cb are formed between the drive electrode 3 and the detection electrode 5.

  FIG. 3B shows a state in which the detection target 21 approaches between the drive electrode 3 and the detection electrode 4. In this state, a part of the electric lines of force 31 are absorbed by the detection target 21, so that the capacitance Ca formed between the drive electrode 3 and the detection electrode 4 is reduced. On the other hand, since the distance between the detected body 21 and the other detection electrode 5 is large and the amount of the electric lines of force 32 absorbed by the detected body 21 is small, the capacitance Cb hardly decreases.

  FIG. 3 (c) shows a state in which the detected object 21 approaches between the drive electrode 3 and the detection electrode 5. In this state, a part of the electric lines of force 32 between the drive electrode 3 and the detection electrode 5 is absorbed by the detected object 21, and thus the capacitance Cb is lowered. On the other hand, the distance difference between the detected body 21 and the other detection electrode 4 is large, and the amount of electric lines of force 31 absorbed by the detected body 21 is small, so the capacitance Ca hardly decreases.

  FIG. 3 (d) shows a state in which the detection target 21 exists in the vicinity of the middle between the detection electrode 4 and the detection electrode 5 in a state in which the detection target 21 approaches the upper part of the drive electrode 3. In this state, since the detected body 21 absorbs both the electric lines of force 31 and 32, both the capacitances Ca and Cb are lowered.

  The output signals of the detection electrodes 4 and 5 of the proximity sensor device in the present embodiment are proportional to the capacitance formed between the electrodes. For this reason, the change in the capacitance (Ca-Cb) between the electrodes is linked to the change in the output signal. Hereinafter, for convenience of explanation, the change in the difference value of the output signal will be described as the change in the difference value of the capacitance between the electrodes (Ca−Cb). In the state of FIG. 3 (a), electrostatic capacitances Ca and Cb having a constant capacity adjusted by the electrode width and the distance between the electrodes are formed. The difference value of the capacitance at this time is (Ca−Cb) = C0. In the state of FIG. 3B, since Ca is smaller than Cb, the difference value (Ca−Cb) is smaller than C0. In the state of FIG. 3C, Cb is smaller than Ca, so the difference value is It becomes larger than C0. Further, in the state of FIG. 3D, since Ca and Cb are both small, the difference value is close to C0.

  On the other hand, in the proximity sensor device of the present embodiment, the influence of noise acts on the entire sensor unit 1. Therefore, the same level of noise affects the detection electrodes 4 and 5. For this reason, the same level of noise acts on the capacitances Ca and Cb formed between the respective electrodes, and the influence of the noise is canceled by calculating the difference value. Suppose that ΔC noise acts on the entire proximity sensor device. In this case, the capacitance formed between the drive electrode 3 and the detection electrode 4 is Ca + ΔC, and the capacitance formed between the drive electrode 3 and the detection electrode 5 is Cb + ΔC. Therefore, the difference value of the capacitance is (Ca + ΔC) − (Cb + ΔC) = Ca−Cb, and the influence of the noise ΔC is canceled out.

  The position of the detection target 21 and the change in the difference value of the capacitance will be described in detail with reference to FIG. In FIG. 4A, the positions of the detected body 21 when the detected body 21 is moved in parallel to the sensor unit 1 while maintaining the distance h are shown at points A to E, respectively. Point A and point E in the figure are distant points where the detected object 21 does not affect the capacitances Ca and Cb. Point B is the point at which the capacitance Ca is reduced most, point C is the point at which the capacitances Ca and Cb are equal, and point D is the point at which the capacitance Cb is reduced most. Further, the initial value C0 of the capacitance of the sensor unit 1 in the figure is adjusted so that Ca-Cb becomes zero at the point where the detected object 21 does not affect the electric force lines 31 and 32, that is, the point A and the point E. It will be described as being done.

  FIG. 4B shows a change in the difference value (Ca−Cb) between the capacitances Ca and Cb corresponding to the position of the detection target 21 as a solid curve. Each point A to point E on the curve indicates the difference value of the electrostatic capacity when the detected object 21 is located at each point A to E in FIG. As described above, when the detected object 21 is located at the point A away from the detection electrode 4, the electrostatic capacitances Ca and Cb are equal, so the electrostatic capacitance difference value (Ca−Cb) is zero. When the detected object 21 is moved from the point A toward the point B, the amount of the electric lines of force 31 absorbed by the hand increases as the detected object 21 approaches the detection electrode 4. On the other hand, since the distance between the detected object 21 and the detection electrode 5 is large, the electric lines of force 32 are hardly absorbed. For this reason, as the detected object 21 moves from the point A to the point B, the capacitance Ca decreases more than the capacitance Cb, and the difference value (Ca−Cb) increases in the negative direction.

  When the detected body 21 is located at a point B on the middle between the detection electrode 4 and the drive electrode 3, the amount of the electric lines of force 31 absorbed by the detected body 21 is maximized. For this reason, the electrostatic capacitance Ca becomes the minimum value, and the difference value becomes the maximum value on the negative side. When the detected object 21 moves from the B point toward the C point, the distance between the detected object 21 and the detection electrode 4 increases, so the electric force lines 31 absorbed by the detected object 21 The amount decreases. On the other hand, since the distance between the detected body 21 and the detection electrode 5 is reduced, the amount of the electric lines of force 32 absorbed by the detected body 21 gradually increases. As described above, the capacitance Ca increases from the point B to the point C, and the capacitance Cb decreases. For this reason, the difference value increases to the positive side.

  When the detected object 21 is located at the point C, the amount of the electric force lines 31 absorbed by the detected object 21 and the amount of the electric force lines 32 are equal. For this reason, the electrostatic capacitances Ca and Cb become equal, and the difference value becomes zero. When the detected object 21 moves from the C point toward the D point, the amount of the electric force lines 32 absorbed by the detected object 21 increases, and the value of the capacitance Cb decreases. On the other hand, since the distance between the detected body 21 and the detection electrode 4 increases, the amount of electromagnetic radiation 31 absorbed by the detected body 21 decreases and the capacitance Ca increases. Therefore, when the detected object 21 moves from the C point toward the D point, the value of Cb becomes smaller than the value of Ca, the difference value becomes a positive value, and the difference value increases to the positive side.

  Since the amount of the electric force lines 32 absorbed by the detected object 21 is maximized at the point D in the middle of the detected electrode 5 and the drive electrode 3 in the detected object 21, the capacitance Cb is minimized and the difference value is obtained. Is the maximum. When the detected object 21 moves from the D point toward the E point, the distance between the detected object 21 and the detection electrode 5 increases, and the amount of the electric lines of force 32 absorbed by the detected object 21. Decrease. For this reason, the electrostatic capacitance Cb increases and the difference value starts to decrease. When the detected object 21 reaches the point E, the detected object 21 does not affect the capacitances Ca and Cb, so the difference value becomes zero.

  In the proximity sensor device according to the present embodiment, the difference value detected by the approach of the detected object takes a positive value and a negative value. For this reason, by setting the threshold value S1 on the positive side and setting the threshold value S2 on the negative side, the proximity of the detected object 21 can be detected in multiple stages. When the detected object 21 moves from point A toward point E in FIG. 4A, the difference value changes as shown by the curve in FIG. 4B. In the section indicated by D1 in FIG. 4A, the difference value is equal to or less than the negative threshold S2 of the curve in FIG. 4B, and is equal to or greater than the positive threshold S1 in the section indicated by D2. Therefore, it is possible to distinguish and detect at least two stages of a section where the difference value is equal to or less than the threshold value S2 and a section where the difference value is equal to or greater than the threshold value S1.

  It is also possible to detect the distance between the detected object 21 and the detection electrodes 4 and 5 using the change in the difference value of the output signal. In the section where the difference value is greater than or equal to the threshold value S1, the detected object 21 exists in the section indicated by D2, and in the section where the difference value is equal to or less than the threshold value S2, the detected object 21 exists in the section indicated by D1. For this reason, by setting the threshold values S1 and S2 to an arbitrary size, the interval between D1 and D2 can be arbitrarily set, and the distance between the detected object 21 and the detection electrodes 4 and 5 is detected. be able to.

  As mentioned above, although the example which has arrange | positioned the drive electrode 3 and the detection electrodes 4 and 5 circularly as an electrode arrangement | positioning of the sensor part 1 of the proximity sensor apparatus of this Embodiment was shown, this invention is not limited to such an electrode structure. . 5A and 5B show a sensor unit 50 in which detection electrodes 52 and 53 are arranged in a straight line with the drive electrode 51 interposed therebetween. In this electrode arrangement, when the detected object 56 as the detected object approaches from the direction of the arrow 54 shown in FIG. 5 (b), the detected object 56 is detected as the detection electrode as in FIG. 4 (a). 52, the difference value changes as shown by the curve in FIG. 4B in order to cross the drive electrode 51 and the detection electrode 53. Therefore, as described above, by detecting whether the difference value is a positive value or a negative value, the approach of the detected object 56 is either from the detection electrode 52 side or from the detection electrode 53 side. Can be determined. Similarly to FIG. 4B, the distances from the detection electrodes 52 and 53 can be detected by arbitrarily setting the threshold values S1 and S2.

  On the other hand, when the detected object 56 approaches the sensor unit 50 from the direction of the arrow 55, the change in the difference value is only one change on the positive side or the negative side. In this case, since the detected body 56 approaches the drive electrode 51 and the detection electrodes 52 and 53 in parallel, it is formed between one of the detection electrodes 52 or the detection electrode 53 close to the detected body 56 and the drive electrode 51. The electrostatic capacitance Ca or Cb decreases more than the other electrostatic capacitance Ca or Cb. For this reason, the difference value becomes one change of the positive side or the negative side. Even in this case, since the noise acts on the entire sensor unit 50, the influence of the noise can be offset by detecting the difference value of the capacitance.

  Hereinafter, application examples using the proximity sensor device in the present embodiment will be described. An input auxiliary device 60 shown in FIG. 6 includes a proximity sensor device 61 that detects the approach of the detection object 62, a control circuit 63 that lights the auxiliary illumination device 65 in response to the proximity information, and an input of the input device 64 by illumination. And an auxiliary illumination device 65 that assists the above. When the operator tries to operate the input device 64, proximity information is detected by the proximity sensor device 61 due to the approach of the detected object 62. The control circuit 63 receives the proximity information and turns on the auxiliary lighting device 65. The operator can confirm the position of the input device 64 by turning on the auxiliary lighting device 65, and the input operation becomes easy.

  In the input auxiliary device 60, the auxiliary operation can be switched to at least two stages by using the positive side difference value and the negative side difference value of the proximity sensor device 61. As described with reference to FIG. 4B, the proximity sensor device 61 can detect the approach of the detected object 62 as the detected object by dividing the difference value on the positive side and the difference value on the negative side. . Threshold values S1 and S2 are provided for the positive value and the negative value of the difference value, respectively, and the auxiliary lighting device 65 is connected via the control circuit 63 in a section where the absolute value of the difference value exceeds one threshold value S1 or S2. Lights up. Further, the auxiliary lighting device 65 is switched through the control circuit 63 in a section in which the detected object approaches and the absolute value of the difference value exceeds the other threshold value S1 or S2, so that the auxiliary operation is performed in multiple stages. You can switch to

  7A and 7B show specific examples of the input assist device. In the input switch device 70 of FIG. 7A, the drive electrode 72 is formed in an annular shape on the insulating substrate 71 as in the sensor unit 1 shown in FIG. The detection electrodes 73 and 74 are formed concentrically with the drive electrode 72 in between, and a switch 75 including an LED as auxiliary illumination is arranged inside the detection electrode 74.

  FIG. 7B is a cross-sectional view taken along the line Y-Y in FIG. When a detected object such as an operator's hand (not shown) approaches the switch 75, proximity information of the detected object is detected by a control circuit 63 (not shown). The control circuit 63 turns on the LED in the switch 75 based on the detected proximity information. The operator can confirm the position of the switch 75 by lighting the LED.

  The proximity sensor device in the present embodiment can be suitably used as an input auxiliary device from the following two points. The first point is that the influence of noise can be reduced. For this reason, it can be used even in an environment where the influence of noise is particularly large as in an automobile. The second point is that the working angle of the sensor is wide. As a device that activates auxiliary illumination based on the proximity of a detection object, for example, a device using an infrared sensor is widely used. However, the operating angle is limited, for example, the infrared sensor cannot be detected when approaching from an oblique direction. However, according to the proximity sensor of the present embodiment, it is possible to detect the approach of the detection object in a wide range of angles, and therefore it can be suitably used as an input auxiliary device.

  FIG. 8 shows an application example of the input assist device. The room lighting input device 80 includes a room lighting switch 81 and LEDs 82 and 83. When the operator 84 approaches the input assisting device 80, the approach of the operator is detected by a proximity sensor device 61 (not shown) built in the input assisting device 80, and the absolute value of the difference value of the capacitance is one threshold value S1 or One LED 82 lights up beyond S2. The operator 84 further approaches the room illumination input device 80, the absolute value of the capacitance difference value exceeds the other threshold value S1 or S2, and the other LED 83 is lit. With this configuration, for example, when operating the room illumination input device 80 in a dark place, the LED 82 is turned on and the location of the room illumination switch 81 is clarified when approaching the room illumination input device 80 to a certain distance. The operator 84 can be fed back to the operator 84 about the proximity of the indoor lighting switch 81, for example, the other auxiliary lighting 83 is turned on while the operator 84 is approaching and touching the indoor lighting switch 81.

  The present invention is not limited to the above-described embodiment. For example, the difference value is detected by inverting the output signal of one of the two detection electrodes, and the scope of the present invention is not deviated. It is possible to carry out a modification with.

  The present invention is applicable to a capacitive proximity sensor device and an input device using the same.

According to the present invention, in the proximity sensor device, the pair of detection electrodes have different electrode widths and / or distances from the drive electrodes, and static electrodes formed between the drive electrodes and the pair of detection electrodes, respectively. as the capacitance becomes equal, and wherein the adjusted distance and or the electrode width between the electrodes. According to this configuration, the difference value of the capacitance when the detection object is not in proximity can be adjusted to be the same, and the calculation process for detecting the detection object can be simplified.

  In the proximity sensor device, the difference value detected by the approach of the detected object takes a positive value and a negative value, and a threshold value is set on each of the positive side and the negative side, thereby detecting the detected object. The proximity is detected in multiple stages.

Claims (8)

  A drive electrode to which a drive voltage is applied, a pair of detection electrodes arranged to form capacitance between the drive electrodes on both sides of the drive electrode, and an output signal of one of the detection electrodes; A proximity sensor device, comprising: a detection circuit that detects a difference value with respect to the other output signal.   The proximity sensor device according to claim 1, wherein the detection circuit detects a distance between an object to be detected and the detection electrode from the difference value.   The proximity sensor device according to claim 1, wherein the drive electrode has an annular shape, and the detection electrode is disposed inside and outside the drive electrode.   The pair of detection electrodes have different electrode widths and / or distances from the drive electrodes, and the electrodes are formed to have the same capacitance formed between the drive electrodes and the pair of detection electrodes, respectively. The proximity sensor device according to claim 1, wherein the distance between the electrodes and / or the electrode width is adjusted.   An input auxiliary device comprising: an input device and a device main body including the proximity sensor device according to claim 1; and an auxiliary device that assists an input operation based on a signal output from the proximity sensor device. .   The input auxiliary device according to claim 5, wherein the auxiliary device turns on an auxiliary illumination device for assisting an input operation as a target.   The input auxiliary device according to claim 5, wherein the auxiliary device switches the auxiliary operation in at least two stages according to the degree of proximity to the proximity sensor device.   An input operation based on a proximity sensor device according to claim 3, a device main body provided with an input device further inside an inner detection electrode provided in the proximity sensor device, and a signal output from the proximity sensor device And an auxiliary device for assisting the input.

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