JP5853755B2 - Input device - Google Patents

Description

  The present invention relates to an input device that gives input commands to various electronic devices by moving a fingertip, a hand, or the like of a person.

  As a device for giving an input command to an electronic device, a technique disclosed in Patent Literatures 1-3 below is known. Patent Document 1 discloses a touch pad input device in a laptop computer. This touch pad input device has x electrodes arranged in parallel, y electrodes perpendicular to the x electrodes, and comb-shaped detection electrodes, and changes according to movement of the fingertip of the operator. This is a device that detects the position of the fingertip by detecting the capacitance between the detection electrodes. In addition, such a touchpad input device does not change the capacitance in a gloved state and cannot give an input command. Therefore, Patent Document 2 discloses a technique in which a conductor is provided on the fingertip of a glove. Thus, the above technique requires contact, and the position cannot be measured without contact.

  As a device for detecting a specific position of a human body in a non-contact manner, a musical instrument called a theremin is well known. Theremin has two antennas, and each antenna is connected to an oscillation circuit. It is a musical instrument that changes the oscillation frequency by changing the capacitance due to the difference in relative distance between the antenna and the human body, and converts the beat of the frequency of the two oscillation circuits into sound. As a position measuring device using the principle of theremin, there is Patent Document 3. In Patent Document 3, a plurality of first antennas arranged in parallel along a first direction and a plurality of second antennas arranged in parallel along a second direction orthogonal to the first direction are configured. A sensor device having an antenna panel is shown. The sensor device is provided with one oscillation circuit that is connected to the first and second antennas with a switch. When the hand of the person approaches the antenna panel, the first antenna and the oscillation circuit are connected. Then, the coordinates in the first direction are determined from the change in the oscillation frequency, and the second direction coordinates are determined from the change in the oscillation frequency by switching to the connection between the second antenna and the oscillation circuit. The position of a human hand can be detected without contact.

  In addition, an example in which a signal processing circuit of a fly's visual system is used as a visual sensor (speed detector) is known (for example, Non-Patent Document 1). This is done by using two left and right optical sensors separated by Δx, converting the light intensity from the two optical sensors into electrical signals, delaying one electrical signal by Δt, and correlating the two electrical signals. The speed is detected.

  Further, as a technique different from the non-contact human body position measurement technique, a technique for propagating an electromagnetic field to the human body surface is known (for example, Non-Patent Document 2). Patent Document 3 discloses a technique for detecting the approach and position of an operator's fingertip using an xy matrix electrode, and detecting a change in capacitance of the electrode as a frequency change.

JP2011-100309 JP2008-81896 JP2010-139280

R. Harrison, "A Biologically Inspired Analog IC for Visual Collosion Detection", IEEE Transactions on Circuits and Systems-1: Regular papers, Vol.52, NO.11, pp.2308-2318,2005 Hideyuki Negiya, “The latest technology of human body communication”, Radio Technology Association Bulletin FORN-200.1 No. 272, pp. 24-27

  However, the technique described above performs position input by detecting a change in capacitance between the electrodes accompanying the movement of the fingertip of the operator. Therefore, it is necessary to provide a plurality of strip-shaped parallel x electrodes and a plurality of strip-shaped parallel y electrodes in a direction orthogonal to the x electrodes, which complicates the apparatus. There's a problem.

  It is also conceivable to construct a device that detects the position of the human body with a light sensor, such as a visual circuit of a fly. However, it is considered that there are a number of problems in sensing with light, such as deterioration in detection accuracy in the depth direction, dynamic range problems, difficulty in detection in dark places, and weakness in lens dirt.

  The present invention is to realize a non-contact type input device based on a completely new principle using a near field that does not propagate as an electromagnetic wave.

  A first invention is an input device for inputting an operation command to an electronic device, an output electrode that generates an electromagnetic field that does not propagate as an electromagnetic wave around the output device, an exciter that generates an electromagnetic field around the output electrode by exciting the output electrode, A plurality of detection electrodes arranged around the output electrode, a phase difference calculator for obtaining a phase difference of a signal obtained from an electromagnetic field detected by the plurality of detection electrodes, and an output of the phase difference calculator as an operation input to the electronic device; This is an input device.

  An electromagnetic field that does not propagate as an electromagnetic wave to the surroundings is a near field that does not have a propagation mode such as an evanescent wave. If the size of the output electrode is reduced to about 1/100 or less of the wavelength of the electromagnetic field, there is no radiation mode from the output electrode, and a near field by an evanescent set wave is formed around the output electrode. As the excitation frequency, 1 to 100 MHz can be used. Therefore, for excitation at 100 MHz, the output electrode may be 3 cm or less. The distance between the output electrode and the detection electrode is preferably 30 cm or less and 3 cm or more. Desirably, 10 cm or less and 3 cm or more can be used. For excitation at 1 MHz, the output electrode may be 3 m or less. In addition, the relationship between the output electrode and the detection electrode can be expanded to about the wavelength or less.

  The number of the plurality of detection electrodes is arbitrary. In addition, it is desirable that the plurality of detection electrodes be provided point-symmetrically with the output electrode as the center for one set of detection electrodes. Further, it is desirable that all the detection electrodes are provided rotationally symmetrically with the output electrode as the center. In addition, the detection electrodes are even numbers, and it is desirable that a plurality of sets of two detection electrodes are provided. However, if one detection electrode is shared, the number of detection electrodes may be an odd number of 3 or more.

  The phase difference calculator is a multiplier that multiplies and outputs the signals output from the two detection electrodes in one set, and a high-frequency component is cut out from the output of the multiplier. It is desirable to be configured with a low-pass filter.

  The phase difference calculator has a first phase shifter connected to the first detection electrode and a second detection electrode when two detection electrodes of the plurality of detection electrodes are a first detection electrode and a second detection electrode. A second phase shifter connected to the electrode and having a phase shift amount equal to that of the first phase shifter, a signal detected by the first detection electrode, and a phase detected by the second detection electrode; A first multiplier that multiplies and outputs the resultant signal, a signal detected by the first detection electrode and phase-shifted by the first phase shifter, and a signal detected by the second detection electrode. A second multiplier that outputs the difference, a subtractor that takes a difference between the output of the first multiplier and the output of the second multiplier, and a low-pass filter that cuts and outputs a high-frequency component out of the outputs of the subtractor; It can comprise as an apparatus which has. At this time, the amount of phase shift of the first phase shifter and the second phase shifter is preferably 90 °. According to this configuration, the output is doubled and the sensitivity can be improved.

  In addition, there are four detection electrodes, and there are two pairs, one set of the first detection electrode and the second detection electrode, and in the line segment connecting the first detection electrode and the second detection electrode of each set. An output electrode is located at a point, and each set of line segments may be orthogonal. In this case, (x, y) orthogonal coordinates on the plane can be input by the position of the fingertip of the operator.

The oscillation frequency of the exciter is desirably 1 to 100 MHz. In this case, a near field that does not propagate as an electromagnetic wave can be formed around the output electrode.
In addition, a data signal transmission device that outputs a data signal to the output electrode can be provided. In this case, the output electrode can be an output terminal for another device. For example, the input end of the cable can be brought close to the output electrode of the input device to transmit data to other devices.
Conversely, a data signal receiving device for inputting a data signal from the output electrode can be provided. For example, the output end of the cable can be brought close to the output electrode of the input device, and data transmitted from another device via the cable can be received by the input device.
The input device according to claim 7 is a first input device, the input device according to claim 8 is a second input device, and the output electrode of the first input device and the output electrode of the second input device are: A transmission device connected by a human body and outputting a data signal output from the output electrode of the first input device from the output electrode of the second input device may be used. In other words, the apparatus has two main input devices, and each of the output devices transmits and receives data by bringing the left and right fingertips of the operator closer to or in contact with each output electrode. Can be done.

  The input device can be a device for inputting various commands to a car audio, a car navigation system (car navigation system), a device for a handicapped person, a game machine, and other general electronic devices in a non-contact manner.

  The input device of the present invention excites a near field that does not propagate as an electromagnetic wave by an output electrode, and detects a phase difference of signals detected by a plurality of detection electrodes existing around the output electrode as a command input. is there. When the operator's fingertip disturbs the near field formed by the output electrode, the phase difference changes. This phase difference is determined by the relative relationship between the position of the fingertip of the operator and the plurality of detection electrodes. As a result, according to the present input device, various commands can be given to the electronic device in a non-contact manner by the position and movement of the operator's fingertip and palm.

  In addition, since the output electrode and the detection electrode need only be provided on the same plane, a multi-layer structure of x electrodes and y electrodes is not required unlike the conventional apparatus, so that the structure is simple and the location is reduced. Instead, the input device has a high degree of freedom in installation.

The figure which showed the structure of the input device of Example 1 which concerns on one specific Example of this invention. FIG. 3 is a diagram illustrating a configuration of output electrodes and detection electrodes of the input device according to the first embodiment. FIG. 3 is a circuit diagram illustrating a configuration of an electromagnetic field detector according to the first embodiment. FIG. 6 is a circuit diagram illustrating a configuration of an electromagnetic field detector according to a modification of the first embodiment. 1 is a configuration diagram showing an input device and a display device in Embodiment 1. FIG. FIG. 3 is a waveform diagram of an output signal obtained by the input device according to the first embodiment. FIG. 3 is a waveform diagram of an output signal obtained when the amplification factor of the amplifier of the input device is increased in the first embodiment. FIG. 6 is a configuration diagram of a transmission apparatus according to a second embodiment. FIG. 6 is a configuration diagram of a device using an input device according to a third embodiment.

  Hereinafter, specific examples of the present invention will be described with reference to the drawings. However, the present invention is not limited to the examples.

  FIG. 1 is a configuration diagram illustrating the entire input device 100 according to the first embodiment. The disc-shaped output electrode 12 having a diameter of 4 cm is provided at the center of the circle. The diameter of the output electrode 12 can be 0.5 cm or more and 5 cm or less. A first detection electrode 20A and a second detection electrode 20B that are a set of detection electrodes, and a first detection electrode 20C and a second detection electrode 20D that are another set of detection electrodes are provided on the circumference. Yes. The output electrode 12 is positioned at the midpoint of the line segment connecting the first detection electrode 20A and the second detection electrode 20B, and the output electrode 12 is positioned at the midpoint of the line segment connecting the first detection electrode 20C and the second detection electrode 20D. Is located. Further, the line segment connecting the first detection electrode 20A and the second detection electrode 20B is orthogonal to the line segment connecting the first detection electrode 20C and the second detection electrode 20D. That is, each of the detection electrodes 20A, 20B, 20C, and 20D is provided at a rotationally symmetric position of 90 ° with the output electrode 12 as the center. The outer edges of the detection electrodes 20A, 20B, 20C, and 20D are in contact with the circumference having a diameter of 10 cm. The diameter of this circumference is arbitrary as long as the near field is formed around the output electrode 12. About 10 cm to 60 cm can be used.

  The output electrode 12 and the detection electrodes 20A, 20B, 20C, and 20D are configured as shown in FIG. FIG. 2 is a cross-sectional view taken along the x axis in FIG. On the upper surface of the resin substrate 44, copper thin films 45, 46 </ b> A, 46 </ b> B that are insulated from each other are formed corresponding to the output electrode 12, the first detection electrode 20 </ b> A, and the second detection electrode 20 </ b> B. The copper thin films 45, 46A and 46B are connected to the center pins 47, 48A and 48B, respectively, and the ground copper thin film 43 connected to the outer conductor of the coaxial cable is provided on the entire back surface of the resin substrate 44. ing. Further, connectors 41, 42A, and 42B are provided in which outer conductors are joined to the ground copper thin film 43 and center pins 47, 48A, and 48B are included. The copper thin film 45 of the output electrode 12 is excited by a signal input from the exciter 1 (FIG. 3) via a coaxial cable (not shown) connected to the connector 41. The electromagnetic field signals detected by the copper thin films 46A and 46B of the first detection electrode 20A and the second detection electrode 20B are detected by the electromagnetic field detector 2A (FIG. 2) via a coaxial cable (not shown) connected to the connectors 42A and 42B. 1, 3).

  The first detection electrode 20C and the second detection electrode 20D are also formed in the same manner as the first detection electrode 20A and the second detection electrode 20B, and these detection electrodes are connected to the electromagnetic field detector 2B (FIG. 1). Yes.

  The configuration of the electromagnetic field detector 2A constituting the phase difference calculator is shown in FIG. The exciter 1 is connected to the output electrode 12. The exciter 1 includes an oscillator 10, a band pass filter 11 and an amplifier 13, and the output of the amplifier 13 is input to the output electrode 12. The oscillation frequency of the oscillator 10 is 1 to 100 MHz. In this embodiment, the frequency is 10.7 MHz. The diameter of the output electrode 12 is desirably 1/100 or less of the wavelength of the electromagnetic field to be excited. The wavelength of the frequency of 10.7 MHz is 28 m. However, when the wavelength is 1/100, that is, the diameter is 28 cm or less, the emission of electromagnetic waves does not occur. As a result, a near field is formed around the output electrode 12 by the evanescent set wave that does not propagate.

  The band pass filter 11 transmits only the frequency band of the electric signal oscillated by the oscillator 10, and the amplifier 13 amplifies the electric signal transmitted through the band pass filter 11. The output electrode 12 excites an electromagnetic field around the output electrode 12 by an electric signal from the amplifier 13. The bandpass filter 11 and the amplifier 13 are not necessarily required, but it is desirable to provide them in order to remove noise and improve the position measurement accuracy.

  The first detection electrode 20A and the second detection electrode 20B are electrodes that receive a near field having a frequency of 10.7 MHz and a wavelength of 28 m formed around the output electrode 12 as an electrical signal. The electromagnetic field detector 2A includes a band-pass filter 21A for inputting an electric signal detected by the first detection electrode 20A, an amplifier 22A, a band-pass filter 21B for inputting an electric signal detected by the second detection electrode 20B, and an amplifier 22B. ing. The band-pass filters 21A and 21B transmit only the oscillation frequency band of the oscillator 10, and the amplifiers 22A and 22B amplify the electric signals from the band-pass filters 21A and 21B, respectively.

  The electromagnetic field detector 2A has multipliers 23A and 23B, respectively. The output of the amplifier 22A is connected to the multiplier 23A via the amplifier 241, and the output of the amplifier 22B is connected via the phase shifter 25A and the amplifier 242. On the other hand, the output of the amplifier 22A is connected to the multiplier 23B via the phase shifter 25B and the amplifier 243, and the output of the amplifier 22B is connected via the amplifier 244. The phase shifter 25A outputs the electrical signal from the second detection electrode 20B, and the phase shifter 25B outputs the electrical signal from the first detection electrode 20A by shifting the phase, and the phase shift amount is equal. Is set. The multiplier 23A multiplies the electrical signal from the first detection electrode 20A and the electrical signal from the second detection electrode 20B phase-shifted by the phase shifter 25A and outputs the result. The multiplier 23B multiplies the electrical signal from the second detection electrode 20B and the electrical signal from the first detection electrode 20A phase-shifted by the phase shifter 25B and outputs the result.

  The outputs of the multipliers 23A and 23B are connected to a subtracter 26. The subtractor 26 takes the difference between the input electric signals and outputs the difference. The output side of the subtractor 26 is connected via an amplifier 27 and a low-pass filter 28 to an A / D converter 29 that converts the output of the low-pass filter 28 into a digital value. The A / D converter 29 is connected to an electronic device (not shown) for giving an operation command. The amplifier 27 amplifies the electric signal output from the subtractor 26, and the low-pass filter 28 cuts and outputs a high frequency component (other than an electric signal close to a direct current component).

The electromagnetic field detector 2B to which the first detection electrode 20C and the second detection electrode 20D as another set of detection electrodes are connected has the same configuration as the electromagnetic field detector 2A shown in FIG.
Next, the operation of the input device 100 will be described.

  First, an oscillator 10 oscillates an electrical signal having a frequency of 1 to 100 MHz, removes noise components and the like through a band-pass filter 11, amplifies the electrical signal by an amplifier 13, and then sets an evanescent set from the output electrode 12 to the surrounding space. Excites a near field that is a wave.

When the fingertip of the operator moves on the internal space formed by the four detection electrodes 20A to 20D, the near field formed around the output electrode 12 is modulated according to the position of the fingertip. The electrical signals detected by the first detection electrode 20A and the second detection electrode 20B have different phases depending on the relative distance between the position of the fingertip of the operator and the first detection electrode 20A and the second detection electrode 20B. Hereinafter, for simplification of description, the electric signal received by the first detection electrode 20A is considered as cos (ωt + θA), and the electric signal received by the second detection electrode 20B is considered as cos (ωt + θB). However, in θA and θB, the advance phase is positive and the delay phase is negative. ω is 2πf, and f is the oscillation frequency of the oscillator 10. In order to improve the position measurement accuracy, it is desirable to bring the fingertip close to a position as close to a straight line connecting the first detection electrode 20A and the second detection electrode 20B as possible, approximately c / (2πf (εr) ^1/2 ) ( Here, f is preferably close to a straight line connecting the first detection electrode 20A and the second detection electrode 20B until f is equal to or less than the oscillation frequency of the oscillator 10 and εr is the relative dielectric constant of the human body. For example, it is close to 50 cm or less at 10.7 MHz.

  The electric signal cos (ωt + θA) received by the first detection electrode 20A is transmitted only through the frequency band of the oscillator 10 by the band-pass filter 21A, and the signal is amplified by the amplifier 22A.

  Further, the electric signal cos (ωt + θB) received by the second detection electrode 20B is transmitted only through the frequency band of the oscillator 10 by the band-pass filter 21B, and the signal is amplified by the amplifier 22B.

  The output from the amplifier 22A is branched into two, one of which is further amplified by the amplifier 241 and then to the multiplier 23A, and the other is phase-delayed by φ by the phase shifter 25B and cos (ωt + θA−φ). The electric signal is amplified by the amplifier 243 and then input to the multiplier 23B.

  Further, the output from the amplifier 22B is branched into two, one of which is further amplified by the amplifier 244 and then the phase is delayed by φ by the phase shifter 25A to the multiplier 23B and the other is cos (ωt + θB− φ), which is amplified by the amplifier 242, and then input to the multiplier 23A.

  That is, the electrical signal of cos (ωt + θA) and the electrical signal of cos (ωt + θB−φ) are input to the multiplier 23A, and the electrical signal of cos (ωt + θA−φ) and cos (ωt + θB) are input to the multiplier 23B. ) Electrical signal is input. Therefore, the output of the multiplier 23A is cos (ωt + θA) · cos (ωt + θB−φ), and is (½) · cos (ψ + φ) except for the high-frequency component cut by the low-pass filter 28 at the subsequent stage. . Here, θA−θB, that is, the phase difference is set as ψ. Similarly, the output of the multiplier 23B is (1/2) · cos (ψ−φ).

  The electrical signals (1/2) · cos (ψ + φ) and (1/2) · cos (ψ−φ) output from the multipliers 23A and 23B are input to the subtractor 26. The output from the subtractor 26 is (1/2) · cos (ψ−φ) − (1/2) · cos (ψ + φ) = sinψ · sinφ. Thereafter, after the signal is amplified by the amplifier 27, the high frequency component which has already been omitted in the calculation is cut by the low-pass filter 28, and the levels sinφ and sinφ are input to the A / D converter 29 and converted into digital values. Thus, a value proportional to the phase difference ψ is output.

  From the A / D converter 29, the voltage value (digital value) of the electric signal sinψ · sinφ is output. This voltage value is a value corresponding to the phase difference ψ (= θA−θB) of the electrical signals received by the first detection electrode 20A and the second detection electrode 20B, and the phase difference ψ is the first detection electrode 20A. And the second detection electrode B and the position of the fingertip of the operator. Therefore, the position of the fingertip in the vicinity of the first detection electrode 20A and the second detection electrode 20B can be measured from the voltage value of the electrical signal sinψ · sinφ. As shown by this result, when φ is 90 °, the output is maximum because sin φ = 1, and therefore, the phase shift amount φ of the phase shifters 25A and 25B is desirably set to 90 °. This is because the sensitivity of position measurement can be improved.

  Consider that the near field by the output electrode 12 is reflected by the fingertip and reaches the first detection electrode 20A and the second detection electrode 20B. When the near field from the output electrode 12 directly reaches the first detection electrode 20 </ b> A and the second detection electrode 2, the in-phase component becomes zero at the output of the subtractor 26. Therefore, the output of the subtracter 26 is a phase difference due to signal components that are not in phase among the signals detected by the first detection electrode 20A and the second detection electrode 20B. The signal component that is not in phase is a component that is detected by the first detection electrode 20A and the second detection electrode 20B as the near field formed from the output electrode 12 is reflected by the fingertip as described above. Further, when considering a signal component that is not an in-phase component, it is sufficient to consider a near-field reflection component by the fingertip, and the reflection component can be regarded as a new wave source from the fingertip.

  Therefore, when the distance between the fingertip and the first detection electrode 20A is equal to the distance between the fingertip and the second detection electrode 20B, the first detection electrode 20A and the second detection electrode 20B are output by reflection at the fingertip. Each electrical signal has the same phase. Therefore, the phase difference ψ becomes zero, and the output signal of the low-pass filter 28 becomes DC zero. In addition, when the fingertip is located immediately above the first detection electrode 20A, the phase difference ψ is a value proportional to the distance L between the first detection electrode 20A and the second detection electrode 20B. That is, ψ = 2πLf / c. Here, f is the oscillation frequency of the oscillator 10 and c is the speed of light. When the fingertip is positioned immediately above the second detection electrode 20B, ψ = −2πLf / c. That is, the position of the fingertip in the section from the midpoint of the first detection electrode 20A and the second detection electrode 20B to the first detection electrode 20A or the second detection electrode 20B can be detected.

  Now, θA and θB are lagging phases, that is, negative values. When the fingertip is positioned at the midpoint between the first detection electrode 20A and the second detection electrode 20B, the distance between the fingertip and each of the first detection electrode 20A and the second detection electrode 20B is equal, so that θA = θB. The phase difference ψ is zero, and the output signal of the low-pass filter 28 is zero. When the fingertip moves from the middle point to the position x toward the first detection electrode 20A, the distance (r−x) between the fingertip and the first detection electrode 20A decreases, and the distance between the fingertip and the second detection electrode 20B (r + x ) Will increase. However, r is r = L / 2, and is the distance from the center of the output electrode 12 to the first detection electrode 20A and the second detection electrode 20B. Therefore, the phase difference ψ (= θA−θB) increases, and the output signal of the low-pass filter 28 increases from zero to a positive region. Conversely, when the fingertip moves from the middle point to the position x (<0) toward the second detection electrode 20B, the distance (r−x) between the fingertip and the first detection electrode 20A increases, and the fingertip and the first 2 The distance (r + x) from the detection electrode 20B decreases. Therefore, the phase difference ψ (= θA−θB) decreases, and the absolute value of the output signal of the low-pass filter 28 increases in the negative region from zero. Eventually, the position of the fingertip can be detected between the first detection electrode 20A and the second detection electrode 20B.

  In this way, if the output signal of the low-pass filter 28 is converted into a digital value by the A / D converter 29, it can be output as a continuous command value for the electronic device that is the target for controlling the position of the fingertip. FIG. 6 shows an output signal of the low-pass filter 28 when the fingertip is reciprocated between the first detection electrode 20A and the second detection electrode 20B along the x axis. The fingertip does not move on the line segment connecting the first detection electrode 20A and the second detection electrode 20B, but moves the upper space along the x-axis direction. Therefore, the distance between the fingertip and the first detection electrode 20A or the second detection electrode 20B is a spatial distance. Therefore, the minimum and maximum appear near the maximum and minimum in FIG. 6 because the x-axis moves beyond the first detection electrode 20A in the positive direction and the x-axis negative exceeds the second detection electrode 20B. This is due to movement in the direction.

  The same can be said for signals detected by a pair of the first detection electrode 20C and the second detection electrode 20D, which are another pair. After all, in FIG. 1, the position (x, y) coordinates of the fingertip on the plane formed by the four detection electrodes 20A, 20B, 20C, and 20D can be detected.

  For example, as shown in FIG. 5, the (x, y) coordinates input by the input device 100 that is the output value of the A / D converter 29 can be displayed on the liquid crystal screen 110. Thereby, the operator can confirm the position command (x, y) by the fingertip.

  Also, a binary command can be given by binarizing the output of the A / D converter 29 with a predetermined threshold. For example, assuming that the output of the A / D converter 29 is in the range of −A or more and A or less, A × (7/10) is the first threshold value and −A × (7/10) is the second threshold value. . When the output of the A / D converter 29 is greater than or equal to the first threshold value, a command to turn on the power to the electronic device to which the command is given by the input device 100; A power-off command can be used. In order to realize the certainty of the input command, the number of times that the output of the A / D converter 29 becomes equal to or more than the first threshold within a predetermined time (for example, 1 second) is equal to or more than the predetermined number (for example, 3 ), The power-off command may be used when the power-on command is equal to or greater than a predetermined number of times (for example, three times). Further, in order to instruct the mode switching between the input of the position command of the (x, y) coordinates and the input of the binary command such as power on / off, the output of the A / D converter 29 is changed within a predetermined time. The mode may be switched alternately when the number of times of alternately repeating the first threshold or more and the second threshold or less is a predetermined number (for example, two times) or more. That is, the mode change command can be made when the fingertip is reciprocated twice or more per second between the first detection electrode 20A and the second detection electrode 20B.

Further, a mode change may be made such that a binary command is given when an external switch (not shown) is turned on, and a command of (x, y) coordinates is given when it is off.
In addition, when inputting a binary command, the amplification factor of the amplifier 27 may be increased to saturate the output. FIG. 7 shows the output of the low-pass filter 28 when the output of the amplifier 27 is saturated. Thereby, the sensitivity of the binary command can be improved. When mode switching is performed by a binary command, normally, the output of the amplifier 27 is saturated, the input sensitivity of the binary command is increased, and the (x, y) coordinates are set by the binary command. When the input mode is changed, the amplification factor of the amplifier 27 may be changed to a gain that does not saturate.

  In the above-described embodiment, an example in which (x, y) plane coordinates are input has been described. However, an apparatus that inputs two detection electrodes and inputs one-dimensional coordinates of the x-axis or y-axis may be used.

  Further, in the electromagnetic field detector 2A, the received two electric signals are divided into two, respectively, and one of them is delayed and multiplied to obtain a difference. This is because the offset is not stabilized simply by multiplying the received electrical signal to cut the high frequency component, and the position measurement accuracy deteriorates. However, when high position accuracy is not required, the phase shifters 25A and 25B, the multiplier 23B, and the subtractor 26 may be omitted from the electromagnetic field fluctuation detector 2A as shown in FIG. In this case, the output signal of the low-pass filter 28 is (1/2) · cos (θA−θB) = (1/2) · cos (ψ). That is, the maximum is at the origin.

  Next, the transmission apparatus 200 according to the second embodiment will be described. As shown in FIG. 8, the transmission apparatus 200 is an apparatus having two input devices 100a and 100b according to the first embodiment. In the input device 100a of the present apparatus, an ASK modulator 51a and an ASK demodulator 52a are connected to the output electrode 12a via the changeover switch 53a in parallel with the exciter 1a. The ASK modulator 51a and the ASK demodulator 52a are connected to an electronic device 60a controlled by the input device 100a. Similarly, in the input device 100b of the present apparatus, an ASK modulator 51b and an ASK demodulator 52b are connected in parallel to the exciter 1b to the output electrode 12b via the changeover switch 53b. The ASK modulator 51b and the ASK demodulator 52b are connected to an electronic device 60b controlled by the input device 101. The ASK modulators 51a and 51b, the ASK demodulators 52a and 52b, and the changeover switches 53a and 53b constitute a data signal transmitting device and a data signal receiving device.

  As shown in FIG. 8, the transmission apparatus 200 brings the operator's left fingertip into contact with or close to the output electrode 12a of the input apparatus 100a, and brings the operator's right fingertip into contact with or close to the output electrode 12b of the input apparatus 100b. . The ASK modulators 51a and 51b are modulators that ASK-modulate a 10.7 MHz carrier wave with a data signal and output the output signals to the output electrodes 12a and 12b. The ASK demodulators 52a and 52b are demodulators that obtain data signals by demodulating signals input from the output electrodes 12a and 12b with a carrier wave of 10.7 MHz. A near field of evanescent waves is excited on the human skin surface against an electromagnetic field of 10.7 MHz. Therefore, an ASK modulation signal can be transmitted from the output electrode 12a of the input device 100a to the output electrode 12b of the input device 100b via the human body. Conversely, an ASK modulated signal can be transmitted from the output electrode 12b of the input device 100b to the output electrode 12a of the input device 100a via the human body. In this way, by using the input devices 100a and 100b, data transmission can be realized between the electronic devices 60a and 60b without using a coaxial cable.

  FIG. 9 shows a case where only the input device 100a is used. The left fingertip of the operator is in contact with or in proximity to the output electrode 12a of the input device 100a, and any part of the operator's body is in contact with or in proximity to the input / output electrodes of the other data transmitting / receiving device 70. Also in this configuration, data transmission / reception by ASK modulation can be performed between the electronic device 60a and the data transmission / reception device 70.

  In the first embodiment, the output of the exciter 1 may be stopped, that is, the near field may not be output from the output electrode 12, and the following may be performed. The oscillator 10 of the exciter 1 may be attached to the arm, and the output electrode 12 of the exciter 1 may be attached to the back of the hand. In this case, a near field is formed around the fingertip from the fingertip of the operator. Also in this case, the position of the fingertip can be detected from the phase difference of detection signals from the plurality of detection electrodes. Further, the output electrode 12 may be provided on a metal portion of the chair on which the operator is seated. In this case, an evanescent wave is excited on the surface of the operator's skin through a chair, and a near field is formed around the operator's fingertips. This also makes it possible to detect the position of the fingertip of the operator. As a result, the position can be specified when the operator is sitting on the seat, but the position cannot be specified when the operator is standing on the seat, which can be used to prevent malfunctions. it can.

  The number of detection electrodes may be arbitrary as long as it is plural, and it is not always necessary to arrange the detection electrodes on the circumference centering on the output electrode 12. If a plurality of detection electrodes are provided at positions separated from the output electrode 12, the spatial positional relationship between the fingertip of the operator and the plurality of detection electrodes can cause a phase difference between signals detected by the detection electrodes. The position of the fingertip can be detected. If a plurality of detection electrodes exist on the same plane, the position on the plane can be input, but it does not need to exist on the plane. When three or more detection electrodes do not exist on the same plane, the input device can detect the spatial coordinates of the fingertip of the operator.

  A wireless connection such as Bluetooth may be used between the input device and the electronic device to which the command is given, or a wired connection may be used. The electronic device is, for example, a car audio, a car navigation (car navigation system), a device for a physically handicapped person, a game machine, a portable device (a mobile phone, a smartphone, a laptop computer, etc.), a TV, or the like. For example, the input device can be used to turn on / off the power of these electronic devices, to switch between AM, FM, and TV for car audio, and to change channels. More specifically, the car audio can be controlled in a non-contact manner such as AM when the hand is swung left and right three times, and FM when the hand is swung left and right four times.

  The input device of the present invention can be used for non-contact operations such as audio devices and car navigation devices. Further, the present invention can be applied to a device for operating a device for a physically handicapped person, a game machine, a portable device or the like in a non-contact manner.

1: exciter 2A, 2B: field detector 60a, 60b: the electronic device 10: Oscillator 12: output electrode 20A, 20 C: the first detection electrode 20 B, 20D: second detection electrodes 23A, 23B: a multiplier 25A, 25B: Phase shifter 26: Subtractor 28: Low-pass filter

Claims (9)

In an input device for inputting an operation command to an electronic device,
An output electrode that generates an electromagnetic field that does not propagate as electromagnetic waves in the surroundings;
An exciter for exciting the output electrode to generate the electromagnetic field in the surroundings;
A plurality of detection electrodes arranged around the output electrode;
A phase difference calculator for obtaining a phase difference of signals obtained from the electromagnetic field detected by the plurality of detection electrodes;
An input device characterized in that an output of the phase difference calculator is used as an operation input to the electronic device. The phase difference calculator is
A multiplier for multiplying and outputting each signal output from the plurality of detection electrodes;
Among the outputs of the multiplier, a low-pass filter that cuts and outputs a high-frequency component;
The input device according to claim 1, further comprising: The phase difference calculator is
A first phase shifter connected to the first detection electrode when two detection electrodes of the plurality of detection electrodes are a first detection electrode and a second detection electrode;
A second phase shifter connected to the second detection electrode and having a phase shift amount equal to the first phase shifter;
A first multiplier for multiplying and outputting a signal detected by the first detection electrode and a signal detected by the second detection electrode and phase-shifted by the second phase shifter;
A second multiplier that multiplies and outputs a signal detected by the first detection electrode and phase-shifted by the first phase shifter and a signal detected by the second detection electrode;
A subtractor that takes a difference between the output of the first multiplier and the output of the second multiplier;
Of the output of the subtractor, a low-pass filter that cuts out and outputs a high-frequency component,
The input device according to claim 1, further comprising:   The input device according to claim 3, wherein a phase shift amount of the first phase shifter and the second phase shifter is 90 °. There are four of the plurality of detection electrodes, the first detection electrode and the second detection electrode are set as one set, and there are two sets, and a line connecting the first detection electrode and the second detection electrode of each set 5. The input device according to claim 3 , wherein the output electrode is located at a midpoint of the minute, and the line segments of each set are orthogonal to each other.   The input device according to claim 1, wherein an oscillation frequency of the exciter is 1 to 100 MHz.   The input device according to any one of claims 1 to 6, further comprising a data signal transmission device that outputs a data signal to the output electrode.   The input device according to claim 1, further comprising a data signal receiving device that inputs a data signal from the output electrode.   The input device according to claim 7 is a first input device, the input device according to claim 8 is a second input device, the output electrode of the first input device, and the output electrode of the second input device. Is a transmission device connected by a human body and inputting a data signal output from the output electrode of the first input device from the output electrode of the second input device.

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