Input device

Abstract

Provided is an input device capable of detecting a position at which an operation input is performed on the basis of an incident signal and a reflected signal. The input device includes: a signal generator that generates a waveform signal; a transmission path that has a first end connected to the signal generator and a second end on the opposite side of the first end, and transmits the waveform signal; a non-reflection terminal part connected to the second end of the transmission path; and a position determination unit that determines the position of the transmission path on the basis of an input signal, which is the waveform signal input from the signal generator to the transmission path, and a reflected signal in which the input signal is reflected to the first end side when an object approaches the transmission path between the first end and the second end of the transmission path. An approach position where the object approaches the transmission path is determined.

Description

Technical Field

[0001] This disclosure relates to input devices. Background Technology

[0002] Conventional biological information detection devices include: a microwave signal source that generates microwave signals; a transmission line without a reflection terminal that transmits microwave signals; and a biological information detection unit that detects the biological information of the subject based on an incident signal input from the microwave signal source to the transmission line and a reflected signal of a leaked electromagnetic wave reflected by the subject on the transmission line. The biological information includes respiratory rate and / or heart rate, body movement, and presence or absence of vital signs (e.g., see Patent Document 1).

[0003] Prior art literature

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2020-116276 Summary of the Invention

[0006] -The problem the invention aims to solve-

[0007] However, conventional biological information detection devices detect respiratory rate, heart rate, body movement, or presence or absence of biological information based on incident and reflected signals, but do not detect the location of inputs made by the biological entity as the object.

[0008] Therefore, the objective is to provide an input device capable of detecting the position of an operational input based on incident and reflected signals.

[0009] -Methods for solving problems-

[0010] The input device according to an embodiment of this disclosure includes: a signal generator that generates a waveform signal; a transmission path having a first end connected to the signal generator and a second end opposite to the first end for transmitting the waveform signal; a non-reflective terminal portion connected to the second end of the transmission path; and a position determination unit that determines the proximity position of the object approaching the transmission path based on an input signal as the waveform signal input from the signal generator to the transmission path and a reflected signal where the input signal is reflected to the first end due to an object approaching the transmission path between the first end and the second end of the transmission path.

[0011] -Invention Effects-

[0012] An input device is provided that can detect the position of an operational input based on incident and reflected signals. Attached Figure Description

[0013] Figure 1 This is a diagram illustrating an example of the structure of the input device according to an embodiment.

[0014] Figure 2A This is a diagram illustrating an example of the waveform of the input signal input from the signal generator to the two mixers (mixers) of the input device in the embodiment.

[0015] Figure 2B This is a diagram illustrating an example of the waveform of the input signal input from the directional coupler to the two mixers (mixers) of the input device in the embodiment.

[0016] Figure 2C This is a diagram showing an example of the I and Q signals output from the two mixers of the input device in the embodiment.

[0017] Figure 2D Represented by IQ coordinates Figure 2C The diagram shows the I and Q signals.

[0018] Figure 3A This is a diagram illustrating an example of a transmission path in which the length Ld of the input device in the embodiment is λg / 2 or more.

[0019] Figure 3B This is a diagram showing an example of the IQ coordinates detected when the length Ld of the transmission path of the input device in the embodiment is λg / 2 or more.

[0020] Figure 4A This is a diagram showing the IQ coordinates obtained by fixing the position of the fingertip FT close to the transmission path at a certain distance, while the signal generator outputs waveform signals of multiple frequencies as input signals.

[0021] Figure 4B This is a diagram showing an example of the distance spectrum obtained by the inverse Fourier transform.

[0022] Figure 4C This is a diagram illustrating an example of the distance spectrum obtained by inverse Fourier transform when the two fingertips are at different positions near the transmission path.

[0023] Figure 5 This is a diagram illustrating an example of the structure of an input device according to a modified embodiment.

[0024] Figure 6A This is a diagram illustrating an example of the structure of the transmission path in a modified embodiment.

[0025] Figure 6B This is a diagram illustrating an example of the structure of the transmission path in a modified embodiment.

[0026] Figure 6C This is a diagram illustrating an example of the structure of the transmission path in a modified embodiment.

[0027] Figure 6D This is a diagram illustrating an example of the structure of the transmission path in a modified embodiment.

[0028] Figure 6E This is a diagram illustrating an example of the structure of the transmission path in a modified embodiment.

[0029] Figure 6F This is a diagram illustrating an example of the structure of the transmission path in a modified embodiment.

[0030] Figure 6G This is a diagram illustrating an example of the structure of the transmission path in a modified embodiment.

[0031] Figure 6H This is a diagram illustrating an example of the structure of the transmission path in a modified embodiment.

[0032] Figure 6I This is a diagram illustrating an example of the structure of the transmission path in a modified embodiment.

[0033] Figure 6J This is a diagram illustrating an example of the structure of the transmission path in a modified embodiment.

[0034] Figure 6K This is a diagram illustrating an example of the structure of the transmission path in a modified embodiment.

[0035] Figure 6L This is a diagram illustrating an example of the structure of the transmission path in a modified embodiment.

[0036] Figure 6N This is a diagram illustrating an example of the structure of the transmission path in a modified embodiment.

[0037] Figure 6P This is a diagram illustrating an example of the structure of the transmission path in a modified embodiment.

[0038] Figure 6Q This is a diagram illustrating an example of the structure of the transmission path in a modified embodiment.

[0039] Figure 7A This is a diagram illustrating an example of the structure of the transmission path in a modified embodiment.

[0040] Figure 7B This is a diagram illustrating an example of the structure of the transmission path in a modified embodiment.

[0041] Figure 7CThis is a diagram illustrating an example of the structure of the transmission path in a modified embodiment.

[0042] Figure 7D This is a diagram illustrating an example of the structure of the transmission path in a modified embodiment.

[0043] Figure 8A This figure illustrates an example of the application of the input device of the embodiment to a musical instrument.

[0044] Figure 8B The piano keyboard and the operational state of the transmission path of the embodiment are shown on the top and bottom sides.

[0045] Figure 9A This is a diagram illustrating an example of the structure of the transmission path in a modified embodiment.

[0046] Figure 9B This is a diagram illustrating an example of the structure of the transmission path in a modified embodiment.

[0047] Figure 9C This is a diagram illustrating an example of the structure of the transmission path in a modified embodiment.

[0048] Figure 9D This is a diagram illustrating an example of the structure of the transmission path in a modified embodiment.

[0049] Figure 9E This is a diagram illustrating an example of the structure of the transmission path in a modified embodiment. Detailed Implementation

[0050] Hereinafter, embodiments of the input device using the present disclosure will be described.

[0051] <Implementation Method>

[0052] Figure 1 This diagram illustrates an example of the structure of the input device 100 according to an embodiment. The input device 100 includes: a signal generator 110, a circulator 120, a transmission path 130, a terminating resistor 140, a phase shifter 150, mixers 160A and 160B, and a control device 170. The circulator 120 is an example of a line connector. The terminating resistor 140 is an example of a termination section. Mixer 160A is an example of a first mixer, and mixer 160B is an example of a second mixer.

[0053] Input device 100 is a device for detecting the position of a fingertip FT approaching the transmission path 130. Input device 100 detects the position (proximity position) of the fingertip FT at any point between the two ends of the transmission path 130. The fingertip FT is an example of an object that the input device 100 detects at its proximity position. The arbitrary position (proximity position) between the two ends of the transmission path 130 approached by the fingertip FT is the operational position where the user of input device 100 brings the fingertip FT close to a certain position between the two ends of the transmission path 130 in order to perform an operation input using the fingertip FT. Here, the object is described as the fingertip FT, but the object is not limited to the fingertip FT; it can be a part of the fingertip FT of the hand, a part of the human body other than the hand, etc. Furthermore, the object can also be a material with a relative permittivity and relative permeability greater than 1.

[0054] As an example, the input device 100 can be applied to the input section of devices such as car power window switches, various switches for the central console, musical instruments (keyboards), various switches for games, various switches for home appliances, or PC (Personal Computer) keyboards.

[0055] The transmission path 130 is disposed in the input section of various devices as described above. The transmission path 130 is typically covered by a coating or cover made of resin or similar material in the input section of various devices. In this case, the fingertip FT does not directly contact the transmission path 130. "Object approaching the transmission path" means that even if the object does not directly contact the transmission path 130, the object approaches the transmission path to a degree that the input device 100 can detect.

[0056] Furthermore, the transmission path 130 may not be covered by a blanket or cover, and the fingertip FT can directly contact the transmission path 130. The phrase "object approaching the transmission path" also includes the meaning of the object directly contacting the transmission path 130.

[0057] <Structure of Input Device 100>

[0058] <Signal Generator 110>

[0059] Signal generator 110 is a signal generator that generates waveform signals. The output terminal of signal generator 110 is connected to one of the first terminal 121 of circulator 120, the input terminal of phase shifter 150, and one of the two input terminals of mixer 160A. In addition, signal generator 110 can also be driven and controlled according to control signals input from control device 170.

[0060] The waveform signal output by signal generator 110 is the input signal to transmission path 130. Furthermore, as an example, this description assumes the waveform signal output by signal generator 110 is a sine wave, but the waveform signal can also be a square wave. Sine wave generators and square wave generators can be used as signal generator 110.

[0061] <Looper 120>

[0062] Circulator 120 has a first terminal 121, a second terminal 122, and a third terminal 123. The first terminal 121 is connected to a signal generator 110, the second terminal 122 is connected to a transmission path 130, and the third terminal 123 is connected to the other of the two input terminals of mixers 160A and 160B. Circulator 120 transmits the signal from the signal generator 110 connected to the first terminal 121 to the transmission path 130, extracts the reflected signal component from the standing wave generated at the second terminal 122 via the transmission path 130, and outputs it from the third terminal 123 to mixers 160A and 160B.

[0063] <Transmission Path 130>

[0064] The transmission path 130 is a transmission path having a conductor and a substrate, and having a first end 131 and a second end 132 opposite to the first end 131. The structure of the conductor and substrate of the transmission path 130 will be described later, but the conductor is disposed between the first end 131 and the second end 132.

[0065] Terminal 131 is connected to terminal 122 of circulator 120, and a terminating resistor 140 is connected to terminal 132. It is desirable to have minimal reflection at the termination point. In the event of reflection, the influence of the reflected wave at the termination point can be eliminated. For example, the reflected wave at the termination point can be measured in advance, and this data can be used for correction. The characteristic impedance of transmission path 130 is Z0 (50Ω, for example). The length between terminal 131 and terminal 132 of transmission path 130 is defined as Ld. Length Ld is the length of transmission path 130.

[0066] Transmission path 130 can be either of an unrestricted electromagnetic field type or an electromagnetically restricted electromagnetic field type. Examples of unrestricted electromagnetic field transmission paths include microstrip lines and coplanar waveguides. Examples of electromagnetically restricted electromagnetic field transmission paths include three-layer striplines and coaxial cables. Specific examples of these are described later using figures.

[0067] Transmission path 130 transmits waveform signals. More specifically, transmission path 130 transmits the input signal input to terminal 131. When the fingertip FT is not close to transmission path 130, the input signal is almost absorbed by the terminating resistor 140 with a resistance value of Z0 (50Ω for example), and almost no reflection occurs. Thus, almost no reflection is theoretically equivalent to zero reflection.

[0068] In addition, such as Figure 1 As shown, when the fingertip FT approaches the middle of the transmission path 130, the impedance of the transmission path 130 changes at the point where the fingertip FT approaches the midpoint of the transmission path 130, thus causing the characteristic impedance of the transmission path 130 to deviate from Z0. Therefore, as... Figure 1 As shown, when the fingertip FT approaches a certain point in the middle of the transmission path 130 (between the first terminal 131 and the second terminal 132), the input signal absorbed by the terminating resistor 140 decreases, and the reflected signal reflected towards the first terminal 131 increases significantly. This significant increase in the reflected signal theoretically corresponds to switching from a state of zero reflection to a state of reflection. Due to the generation of the reflected wave, a standing wave is generated between the first terminal of the transmission path 130 and the location approached by the fingertip FT. The circulator 120, connected to the first terminal 131 of the transmission path 130, extracts the reflected wave component generated by the fingertip FT from the standing wave and outputs the reflected wave component from the third terminal of the circulator 120. The reflected signal is input from the first terminal 131 to the circulator 120 and output from the third terminal 123.

[0069] <Terminating Resistor 140>

[0070] The terminating resistor 140 is a terminating resistor connected to the second terminal 132 of the transmission path 130, and has a resistance value Z0 equal to the characteristic impedance Z0 of the transmission path 130. Therefore, when the fingertip FT is not close to the transmission path 130, almost no reflection of the input signal is generated at the second terminal 132.

[0071] <Phase Shifter 150>

[0072] Phase shifter 150 has an input terminal connected to the output terminal of signal generator 110, and an output terminal connected to one of the two input terminals of mixer 160B. Phase shifter 150 is a phase shifter that shifts the phase of the input signal input to the input terminal by π / 2 (180 degrees) and outputs it to mixer 160B.

[0073] <Mixer 160A>

[0074] Mixer 160A has two input terminals connected to the output terminal of signal generator 110 and the third terminal 123 of circulator 120, and an output terminal connected to control device 170. Mixer 160A mixes the input signal from signal generator 110 and the reflected signal component of standing wave from circulator 120 to generate a first signal, and outputs the first signal to control device 170. The first signal (an example of the first signal) is an I (In-Phase) signal.

[0075] <Mixer 160B>

[0076] Mixer 160B has two input terminals connected to the output terminal of phase shifter 150 and the third terminal 123 of circulator 120, and an output terminal connected to control device 170. Mixer 160B mixes the input signal (phase-shifted by π / 2) from phase shifter 150 with the reflected signal component of the standing wave from circulator 120 to generate a second signal, which is then output to control device 170. The second signal (an example of the second signal) is a Q (Quadrature-phase) signal. The phase of the Q signal differs from that of the I signal by 90 degrees.

[0077] <Control Device 170>

[0078] The control device 170 has a position determination unit 171. The control device 170 is implemented by a computer, which includes a CPU (Central Processing Unit), RAM (Random Access Memory), ROM (Read Only Memory), input / output interfaces, and an internal bus, etc.

[0079] The position determination unit 171 represents the function of the program executed by the control device 170 as a function block. In addition to the position determination unit 171, the control device 170 also has a drive control unit for driving control of the signal generator 110, etc., but these are omitted here.

[0080] The position determination unit 171 determines the proximity position based on the input signal and reflected signal input from the signal generator 110 to the transmission path 130. Specifically, the position determination unit 171 determines the proximity position based on an I signal generated based on the input signal and the reflected signal, and a Q signal generated based on the input signal and the reflected signal. More specifically, the position determination unit 171 determines the proximity position based on a first signal (I signal) output from mixer 160A and a second signal (Q signal) output from mixer 160B. Regarding the method by which the position determination unit 171 determines the proximity position of the fingertip FT, using... Figures 2A to 2D Please provide an explanation.

[0081] Next, we will explain the methods for determining the proximity position of the fingertip FT when the length Ld between the first end 131 and the second end 132 of the transmission path 130 is less than λg / 2, and the methods for determining the proximity position of the fingertip FT when the length Ld between the first end 131 and the second end 132 of the transmission path 130 is greater than or equal to λg / 2. λg is the effective length of the wavelength λ within the transmission path, which is obtained by multiplying the wavelength λ in free space of the electromagnetic wave at the frequency of the input signal by the reciprocal of the square root of the effective relative permittivity εr of the transmission path 130.

[0082] The effective length λg is represented by the following formula (1).

[0083] [Mathematical Expression 1]

[0084]

[0085] <Method for determining the approximate position of the fingertip FT when the length Ld is less than λg / 2>

[0086] Figure 2A This is a diagram illustrating an example of the waveform of the input signal to mixers 160A and 160B. Figure 2A In the diagram, the horizontal axis represents the time axis, and the vertical axis represents the signal level of the input signal. For example... Figure 2A As shown, the phase difference between the input signals to mixers 160A and 160B is π / 2. Additionally, in Figure 2A The waveform shown is the one with the amplitude of the input signal normalized to 1.

[0087] Figure 2B This is a diagram illustrating an example of the waveform of the reflected signal input to mixers 160A and 160B. Figure 2B In the diagram, the horizontal axis represents the time axis, and the vertical axis represents the signal level of the reflected signal. Figure 2B As an example, the waveform of the reflected signal of the fingertip FT at a stationary position at a distance L from the first end 131 is shown. That is, the distance L is the distance between the position where the fingertip FT approaches the transmission path 130 and the first end 131. Since the reflected wave reflected by the fingertip FT is part of the incident signal, the amplitude of the reflected signal is smaller than the amplitude of the input signal. Furthermore, the phase of the reflected signal at the first end 131 is delayed by an amount corresponding to the distance L compared to the input signal at the first end 131.

[0088] Figure 2C This diagram illustrates an example of the I and Q signals output from mixers 160A and 160B. Figure 2C In the diagram, the horizontal axis represents the time axis, and the vertical axis represents the I and Q signals.

[0089] The amplitude ratio of the I and Q signals is represented by the voltage reflection coefficient of the reflected signal relative to the input signal. When the fingertip FT is stationary, the phase of the reflected wave is delayed from the phase of the input signal by a amount corresponding to the distance L, therefore... Figure 2C As shown, the I and Q signals, which are the outputs of mixers 160A and 160B, become constant.

[0090] Figure 2D Represented by IQ coordinates Figure 2C The diagram shows the I and Q signals. Figure 2D In the diagram, the horizontal axis represents the I-axis, which indicates the signal level of the I signal, and the vertical axis represents the Q-axis, which indicates the signal level of the Q signal. φ in the diagram represents the phase of the reflected wave.

[0091] Furthermore, when the length Ld of the transmission path 130 is less than λg / 2, the phase of the reflected wave has a one-to-one relationship with the distance L, so the distance L can be calculated relatively easily as follows.

[0092] The phase φ of the reflected signal (reference) Figure 2D The reflected signal is represented by tanφ = Q / I. In addition, the reflected signal is represented by the following equation (3). In equation (3), B is a given constant, and Le is the electrical length of the distance L obtained by multiplying the distance L by the square root λ of the effective relative permittivity εr of the transmission path 130, hereinafter referred to as Le.

[0093] The relationship between Le and distance L is expressed by the following equation (2). Furthermore, f is the frequency of the reflected signal, which is equal to the frequency of the input signal. c is the speed of electromagnetic waves in a vacuum.

[0094] [Mathematical Expression 2]

[0095]

[0096] [Mathematical Expression 3]

[0097]

[0098] Furthermore, if the length Ld of the transmission path 130 is less than λg / 2, and the phase of the reflected signal when Le = 0 is set to φ0, then according to equation (3), the phase of the reflected signal when the distance between the fingertip FT and the first end 131 is L is expressed by the following equation (4).

[0099] [Mathematical Expression 4]

[0100]

[0101] According to equation (4), the distance L between the proximity position of the fingertip FT proximity transmission path 130 and the first end 131 is expressed by equation (5).

[0102] [Mathematical Expression 5]

[0103]

[0104] Based on Le obtained from equation (5), the distance L can be obtained according to equation (6).

[0105] [Mathematical Expression 6]

[0106]

[0107] Since φ0 can be known in advance, as long as the phase φ of the reflected signal is calculated from the I and Q signals as described above, the distance L between the approach position of the fingertip FT and the first end 131 can be calculated according to Equation (6), and the approach position of the fingertip FT can be determined. The above calculation can be performed by the position determination unit 171.

[0108] <Method for determining the approximate position of the fingertip FT when the length Ld is greater than λg / 2>

[0109] When the length Ld of the transmission path 130 is greater than λg / 2, the phase of the reflected wave is not one-to-one with the distance L, so L cannot be calculated as described above.

[0110] Figure 3A This is a diagram showing an example of a transmission path 130 with a length Ld of λg / 2 or more. Figure 3B This is a diagram showing an example of the IQ coordinates detected when the length Ld of the transmission path 130 is greater than or equal to λg / 2.

[0111] like Figure 3A As shown, assume that along the transmission path 130, there are points P1, P2, P3, and P4 at intervals of λg / 2. Figure 3B As shown, the phase φ of the I and Q signals obtained when the fingertip FT approaches points P1, P2, P3, and P4 is all the same. That is, when the fingertip FT moves along the transmission path 130 with a length Ld of λg / 2 or more, the IQ coordinates rotate once for every distance λg / 2 that the fingertip FT moves, and the phase of the reflected wave is not one-to-one with the distance L.

[0112] For this reason, when the length Ld of the transmission path 130 is greater than λg / 2, the distance L can be calculated as follows.

[0113] Figure 4AThis diagram shows the IQ coordinates obtained by fixing the fingertip FT at a certain distance from the transmission path 130 while outputting waveform signals of multiple frequencies as input signals from the signal generator 110. Here, it is assumed that when integers greater than 2 are set to N, N IQ coordinates are obtained using input signals of N different frequencies, resulting in IQ coordinates (1) to (N).

[0114] In addition, here we will explain the method of obtaining N IQ coordinates (1) to (N) using input signals of N types of frequencies, but it is also possible to use a chirp signal with continuously changing frequency instead of input signals of multiple frequencies.

[0115] An example of a method for determining proximity location using multiple voltage reflection coefficients calculated with respect to multiple frequencies is shown below.

[0116] If we consider the IQ coordinates relative to each frequency as a function of frequency f and perform an inverse Fourier transform, we obtain a function of time t. Multiplying this time t by the velocity c, and dividing by 2 since it's a round trip, yields a function of distance x. The absolute value of this distance function is the distance spectrum. The peak position of the distance spectrum is given by Le.

[0117] Figure 4B This is a diagram illustrating an example of the distance spectrum obtained from the inverse Fourier transform. Figure 4B In the diagram, the horizontal axis represents electrical length, and the vertical axis represents the signal level of the distance spectrum. The electrical length of the peak value in the distance spectrum is given as the electrical length Le of the position where the tip FT approaches the transmission path 130. Thus, the electrical length Le can be detected.

[0118] Furthermore, by substituting the electrical length Le into equation (6) above, the distance L can be calculated. Thus, it is possible to detect that the approach position of the fingertip FT when the length Ld of the transmission path 130 is λg / 2 or greater is a position at a distance L from the first end 131. This calculation can be performed by the position determination unit 171. This method can also be applied to cases where the length Ld of the transmission path 130 is less than λg / 2.

[0119] The above explanation addresses the case of a single detection target. However, when there are multiple detection targets, the location of the targets can be detected by calculating the distance spectrum.

[0120] As an example, when the two fingertips are located at different positions near the transmission path 130, the inverse Fourier transform is used to obtain... Figure 4C The distance spectrum is shown. Figure 4C This is a diagram of an example of the distance spectrum obtained by inverse Fourier transform when the two fingertips are at different positions near the transmission path 130.

[0121] like Figure 4C As shown, peak values ​​are obtained at the two locations of electrical lengths Le1 and Le2. If the electrical lengths Le1 and Le2 are substituted into equation (6) above, the distances L1 and L2 can be calculated. Thus, when the two fingertips FT approach different positions of the transmission path 130, the proximity positions of the two fingertips FT can be detected as distances L1 and L2. Distances L1 and L2 are distances from the first end 131. Such calculations can be performed by the position determination unit 171. In addition, the case of two fingertips FT approaching the transmission path 130 as two objects is described here, but the two objects are not limited to fingertips FT, and can be a part of the fingertips FT of the hand, a part of the human body other than the hand, etc. In addition, it can also be a material with a relative permittivity and relative permeability greater than 1.

[0122] <Input device 100 of the modified example>

[0123] Figure 5 This is a diagram illustrating an example of the structure of the input device 100, a modified embodiment of the present invention. Figure 5 The input device 100 shown includes: a signal generator 110, a directional coupler 120A, a transmission path 130, a terminating resistor 140, a phase shifter 150, mixers 160A and 160B, and a control device 170. Figure 5 The input device 100 shown replaces the circulator 120 (see reference). Figure 1 It includes a directional coupler 120A. Other structures are similar to... Figure 1 The input device 100 shown is the same. Here, the directional coupler 120A will be described. The directional coupler 120A is an example of a line connector.

[0124] <Directional Coupler 120A>

[0125] The directional coupler 120A has a first terminal 121, a second terminal 122, and a third terminal 123. The first terminal 121 is connected to the signal generator 110, the second terminal 122 is connected to the transmission path 130, and the third terminal 123 is connected to the other of the two input terminals of mixers 160A and 160B. The interval between the first terminal 121 and the second terminal 122 of the directional coupler 120A is inserted between the signal generator 110 and the transmission path 130. The reflected signal component is extracted from the standing wave generated from the transmission path 130 to the second terminal 122 and output from the third terminal 123 to mixers 160A and 160B.

[0126] In this way, the operation of the input device 100 including the directional coupler 120A is the same as the operation of the input device 100 including the circulator 120, and the proximity position of the fingertip FT can be determined.

[0127] <Changes to transmission path 130>

[0128] Figures 6A to 6Q as well as Figures 7A to 7D This is a diagram illustrating an example of the structure of transmission paths 130A-130Q and 130M1-130M2 in a modified example. Transmission paths 130A-130Q and 130M1-130M2 can replace... Figure 1 The transmission path 130 shown is utilized. Hereinafter, the upper and lower surfaces of the substrate 135 will be used for explanation, but this does not represent a general vertical relationship.

[0129] Here, the XYZ coordinate system is defined for explanation. The directions parallel to the X-axis (X direction), the Y-axis (Y direction), and the Z-axis (Z direction) are orthogonal to each other. Furthermore, "top view" refers to observation from the XY plane. Additionally, to facilitate understanding of the structure, the length, thickness, etc., of each part may be exaggerated in the following descriptions. The Y direction is the direction of the transmission paths 130A–130Q and 130M1–130M2.

[0130] <Transmission path of unrestricted electromagnetic fields>

[0131] Figures 6A to 6Q The transmission paths 130A to 130Q shown are transmission paths of the type where the electromagnetic field is not restricted.

[0132] Figure 6A The transmission path 130A shown is a transmission path composed of a microstrip line having a substrate 135, a line 136A, and a ground layer 137A. The substrate 135 is made of an insulator, and for example, is a flexible substrate or a rigid substrate such as FR4 (Flame Retardant type 4). For example, the line 136A and the ground layer 137A are made of a conductor such as copper foil. The line 136A is formed on the upper surface of the substrate 135, and the ground layer 137A is formed on the lower surface of the substrate 135. The line 136A and the ground layer 137A extend from the first end 131 to the second end 132.

[0133] Figure 6B The transmission path 130B shown is a transmission path composed of a coplanar waveguide having a substrate 135, a line 136B, and a ground layer 137B. As an example, the line 136B and the ground layer 137B are made of conductors such as copper foil. The line 136B and the ground layer 137B are formed on the upper surface of the substrate 135, and the substrate 135B is disposed on both sides of the line 136B, extending along the line 136B from the first end 131 to the second end 132.

[0134] Figure 6CThe transmission path 130C shown includes a substrate 135, a line 136C, a ground layer 137B, and a ground layer 137C. Transmission path 130C is... Figure 6B The transmission path 130B shown is a transmission path formed by a grounded coplanar waveguide with a grounded layer 137C added to the back side of the substrate 135.

[0135] Figure 6D The transmission path 130D shown is a transmission path consisting of a substrate 135 and a ground layer 137D. The ground layer 137D is formed on the upper surface of the substrate 135, and a groove 136D is formed from the first end 131 to the second end 132.

[0136] Figure 6E The transmission path 130E shown is generated by... Figure 6D The transmission path 130E shown is formed by grounding grooves of grounding layer 137E on the back side of substrate 135.

[0137] Figure 6F The transmission path 130F shown is composed of... Figure 6B The ground layer 137B of the transmission path 130B shown is provided as ground layer 137F on the lower surface side of the substrate 135, forming a transmission path composed of deformed coplanar waveguides.

[0138] Figure 6G The transmission path 130G shown has two parallel lines 136G formed on the upper surface of the substrate 135. Differential signals, in-phase signals, or out-of-phase signals can flow through the two parallel lines 136G.

[0139] Figure 6H The transmission path 130H shown is a three-layer board structure with two substrates 135, a line 136H, and ground layers 137H1 and 137H2. The lower substrate 135 and line 136H are equivalent to... Figure 6A The substrate 135 and line 136A of the transmission path 130A are shown. The transmission path 130H has the following structure: Figure 6A Another substrate 135 is stacked on line 136A of the transmission path 130A shown, and a grid-shaped ground layer 137H1 is disposed on it. Since the ground layer 137H1 is grid-shaped, the electromagnetic field is not confined and propagates upwards along the transmission path 130H.

[0140] Figure 6I The transmission path 130I shown has a transmission path from Figure 6H The transmission path 130H shown omits the upper substrate 135. Transmission path 130I is a three-layer transmission path. The ground layer 137H1 only needs to be placed... Figure 6IComponents not shown (e.g., the housing of input device 100, etc.) may be used. Since the grounding layer 137H1 is grid-like, the electromagnetic field is not confined and propagates upwards along the transmission path 130H.

[0141] Figure 6J The transmission path 130J shown has the ability to transmit data. Figure 6H The ground layer 137H2 of the transmission path 130H shown is changed to a grid-like metal layer structure. The transmission path 130J is a three-layer plate transmission path. Since the ground layers 137H1 and 137H2 are grid-like, the electromagnetic field is not confined and propagates upwards and downwards along the transmission path 130H.

[0142] Figure 6K The transmission path 130K shown is a pair of conductive wires. Because the pair of conductive wires in transmission path 130K are not covered by a grounding layer or the like, the electromagnetic field is not confined and propagates around the conductive wires.

[0143] Figure 6L The transmission path 130L shown is a transmission path 130 in which an insulating layer 135L covers the area around the conductive line 136L, and a grid-like grounding layer 137L is provided on the side of the insulating layer 135L. Since the grounding layer 137L is grid-like, the electromagnetic field is not confined and propagates to the outside of the grid-like grounding layer 137L.

[0144] Figure 6N The transmission path 130N shown is a dielectric mirror line with a dielectric sheet 135N disposed on a ground plane 137N. The dielectric sheet 135N and the ground plane 137N extend between the first end 131 and the second end 132. Radio waves are transmitted along the dielectric sheet 135N.

[0145] Figure 6P The transmission path 130P shown is in Figure 6N A dielectric mirror line of dielectric sheet 135P is provided between dielectric sheet 135N and ground layer 137N. Dielectric sheet 135P is disposed on the entire upper surface of ground layer 137N. The relative permittivity ε1 of dielectric sheet 135N is greater than the relative permittivity ε2 of dielectric sheet 135P (ε1>ε2). Therefore, radio waves are confined by dielectric sheet 135P and propagate along dielectric sheet 135P.

[0146] Figure 6Q The transmission path 130Q shown is constructed of a cylindrical dielectric. The cylindrical dielectric constituting the transmission path 130Q extends between the first end 131 and the second end 132. Figure 6QThe image shows the internal electric and magnetic fields by removing one-quarter of the circular shape of the cylindrical dielectric. The electric and magnetic fields are orthogonal to each other. This allows radio waves to be transmitted using a transmission path 130Q that does not contain conductors. Furthermore, radio waves can be supplied to the transmission path 130Q simply by placing an antenna or similar device at one end of the transmission path 130Q.

[0147] <Transmission path of electromagnetic field confinement>

[0148] Figures 7A to 7D The transmission paths 130M1 to 130M8 shown are transmission paths of the type where the electromagnetic field is confined.

[0149] Figure 7A as well as Figure 7B The transmission path 130M1 shown includes: a substrate 135, a line 136M1, a ground layer 137M1, an elastomer such as sponge 138M1, and a metal layer 139M1. Figure 7A The image shows the XZ section, which is perpendicularly cut in the extension direction (Y direction) of line 136M1. Figure 7B The image shows the YZ section along the extension direction (Y direction) of line 136M1. Figure 7A In the middle, line 136M1 extends in the direction that runs through the attached diagram, in Figure 7B In the middle, line 136M1 extends in the left and right directions.

[0150] Transmission path 130M1 is a three-layer board transmission path. A ground layer 137M1 is disposed on the lower surface of substrate 135, and a line 136M1 is disposed on the upper surface of substrate 135. The ground layer 137M1 is a metal foil covering the entire lower surface of substrate 135. The structure of substrate 135, line 136M1, and ground layer 137M1 is the same as that of microstrip lines.

[0151] An elastomer 138M1 and a metal layer 139M1 are disposed on the substrate 135 and the line 136M1. The top dimensions of the elastomer 138M1 and the metal layer 139M1 are equal to the top dimensions of the substrate 135. The metal layer 139M1 is a thin metal foil, such as aluminum foil. In the transmission path 130M1, since the lower side is covered by the ground layer 137M1 and the upper side is covered by the metal layer 139M1, the electromagnetic field generated by the propagation of the input signal and the reflected signal in the line 136M1 is confined within the transmission path 130M1.

[0152] like Figure 7BAs shown, when the upper surface of the transmission path 130M1 is pressed downwards, the metal layer 139M1 is recessed, thus reflecting the electric field propagating from the left side. Therefore, the distance to the pressed position can be calculated. Furthermore, since the reflection occurs at the pressed position, it is more advantageous than capacitive sensors in that, for example, the presence of water droplets on the metal layer 139M1 will not affect the distance calculation.

[0153] Figure 7C as well as Figure 7D The transmission path 130M2 shown includes a line 136M2, an elastomer such as sponge 138M2, and a grounding layer 139M2. Figure 7C The image shows the XZ section, which is perpendicularly cut in the extension direction (Y direction) of line 136M2. Figure 7D The image shows the YZ section along the extension direction (Y direction) of line 136M2. Figure 7C In the middle, line 136M2 extends in the direction that runs through the attached diagram, in Figure 7D In the middle, line 136M2 extends in the left and right directions.

[0154] The line 136M2 is surrounded by an elastic body 138M2, which in turn is surrounded by a grounding layer 139M2, thus forming a structure similar to a coaxial cable. In the transmission path 130M2, because the line 136M2 is surrounded by the grounding layer 139M2, the electromagnetic field generated by the propagation of input and reflected signals through the line 136M2 is confined within the transmission path 130M2.

[0155] like Figure 7D As shown, when the side of the transmission path 130M2 is pressed towards the center, the grounding layer 139M2 is recessed, thus reflecting the electric field propagating from the left side. Therefore, the distance to the pressed position can be calculated. Furthermore, since the reflection occurs at the pressed position, it is more advantageous than capacitive sensors in that, for example, the presence of water droplets on the grounding layer 139M2 will not affect the distance calculation.

[0156] <Application of Musical Instruments>

[0157] Figure 8A This diagram illustrates an example of the application of the input device 100 to a musical instrument. Figure 8A The diagram shows the configuration of transmission path 130A under the piano keyboard 50 (see reference). Figure 6A The structure of ). In Figure 8B The piano keyboard 50 and the operational state of the transmission path 130A are shown on the upper and lower sides. A metal layer 51 is provided on the lower surface of the keyboard 50. The transmission path 130 extends along the direction in which the multiple keyboards 50 are arranged.

[0158] When from Figure 8B The upper side shows the state where the keyboard is not pressed (50). Figure 8B When a key 50 is pressed as shown on the lower side, since the metal layer 51 is close to the transmission path 130, it is possible to detect which key 50 has been operated by calculating the distance from the first end 131. An electronic piano can be constructed that detects the key 50 being operated and outputs the corresponding sound.

[0159] Furthermore, by providing a left-right gap in the keyboard 50, the distance detected by the input device 100 can be subtly varied. It can also be configured to subtly shift the interval of the output sound vertically in response to such subtle changes in distance. This allows for the output of sounds that a typical piano cannot produce.

[0160] Furthermore, if the keyboard 50 is not provided and the transmission path 130A is set as the operation section of the instrument, the position of operation in the transmission path 130A can be detected steplessly. Therefore, the sound of a stepless scale can be output corresponding to the stepless position, thus realizing a stepless scale instrument.

[0161] <Other variations>

[0162] Figures 9A to 9C This is a diagram illustrating an example of the structure of transmission paths 130M3 to 130M5 in a modified embodiment. Transmission paths 130M3 to 130M5 have a planar structure. Figure 9A The transmission path 130M3 shown is tortuous and winding. Figure 9B as well as Figure 9C The transmission paths 130M4 and 130M5 shown have curved portions that are more... Figure 9A The shape shown is multiple transmission paths of 130M3. Transmission paths 130M3 to 130M5 can also be used instead. Figure 1 The transmission path shown is 130.

[0163] Figure 9D as well as Figure 9E This is a diagram illustrating an example of the structure of the transmission path 130M6 in a modified embodiment. Figure 9D In the diagram, the transmission path 130M3 is shown in decomposition. Figure 9E The image shows the transmission path 130M3 when viewed from above.

[0164] The transmission path 130M3 includes: input / output terminals 131M6 and 132M6, a metal layer 136M6, a metal layer 137M6, and an electromagnetic wave absorber 138M6. As an example, metal layer 136M6 is a rectangular metal foil when viewed from above, and metal layer 137M6 is a rectangular grid-like metal layer when viewed from above. Metal layers 136M6 and 137M6 are arranged opposite each other and connected via input / output terminals 131M6 and 132M6. Furthermore, an electromagnetic wave absorber 138M6 is provided to surround the outer edges of the oppositely arranged metal layers 136M6 and 137M6.

[0165] Input / output terminal 131M6 is located at the center of the X-direction end of the outer edge of the opposing metal layers 136M6 and 137M6 on the -Y-direction side, and is connected to the metal layers 136M6 and 137M6. Input / output terminal 132M6 is located at the center of the Y-direction end of the outer edge of the opposing metal layers 136M6 and 137M6 on the +X-direction side, and is connected to the metal layers 136M6 and 137M6.

[0166] The input / output terminals 131M6 and 132M6 of this transmission path are equivalent to Figure 1 The first end 131 of the transmission path 130 shown. If two are prepared... Figure 1 The portion of the input device 100 shown, excluding the transmission path 130, is connected to input / output terminals 131M6 and 132M6. This allows the Y-direction position of the fingertip FT to be detected via input / output terminal 131M6, and the X-direction position of the fingertip FT to be detected via input / output terminal 132M6. In other words, the XY coordinates of the fingertip FT can be set.

[0167] <Effect>

[0168] The input device 100 includes: a signal generator 110 that generates a waveform signal; a transmission path 130 having a first end 131 connected to the signal generator 110 and a second end 132 opposite to the first end 131, for transmitting the waveform signal; a terminating resistor 140 (terminal portion) connected to the second end 132 of the transmission path 130; and a position determination unit 171 that determines the proximity position based on an input signal, which is a waveform signal input from the signal generator 110 to the transmission path 130, and a reflected signal where the input signal is reflected to the first end 131 side when an object approaches the transmission path 130 between the first end 131 and the second end 132. Therefore, the position (proximity position) for operation input via an object can be determined.

[0169] Therefore, an input device 100 is provided that can detect the position (proximity position) of the operation input based on the incident signal and the reflected signal.

[0170] Alternatively, the position determination unit 171 may determine the proximity position based on a first signal level related to the reflected signal component of the standing wave generated based on the input signal and the reflected signal, and a second signal level related to the reflected signal component of the standing wave whose phase differs from the first signal level by π / 2. An input device 100 capable of detecting the position (proximity position) of an operation input based on the first signal level and the second signal level can be provided.

[0171] Alternatively, the input device 100 may also include: a circulator 120 having a first terminal 121 connected to the signal generator 110, a second terminal 122 connected to the transmission path 130, and a third terminal 123, wherein the interval between the first terminal 121 and the second terminal 122 is inserted between the signal generator 110 and the transmission path 130, and the reflected signal is output from the third terminal 123; and a mixer 160A having two input terminals connected to the signal generator 110 and the third terminal 123, for mixing the input signal and the reflected signal component of the standing wave. The input device 160A outputs a first signal level; a phase shifter 150, connected to a signal generator 110, shifts the phase of the input signal by π / 2 and outputs it; a mixer 160B, having two input terminals connected to the phase shifter 150 and a third terminal 123, mixes the input signal (shifted by π / 2 by the phase shifter 150) and the reflected signal component of the standing wave, and outputs a second signal level; the position determination unit 171 determines the proximity position based on the first signal level of the first standing wave output from the mixer 160A and the second signal level of the second standing wave output from the mixer 160B. This provides an input device 100 capable of detecting the position (proximity position) of an operation input based on the first signal level of the first standing wave output from the mixer 160A and the second signal level of the second standing wave output from the mixer 160B.

[0172] Alternatively, if the wavelength of the electromagnetic wave in the frequency of the waveform signal is set to λ, the length between the first end 131 and the second end 132 of the transmission path 130 is less than λg / 2. An input device 100 can be provided that can detect the position (proximity position) of the operation input based on the first signal level and the second signal level of the second standing wave output from the mixer 160B when the length between the first end 131 and the second end 132 is less than λg / 2.

[0173] Alternatively, the signal generator 110 can output waveform signals at multiple frequencies, and the position determination unit 171 calculates voltage reflection coefficients at each of the multiple frequencies based on a first signal level of a standing wave generated based on the input signal and the reflected signal, and a second signal level whose phase differs from the first signal level by π / 2. Using the multiple voltage reflection coefficients calculated with respect to the multiple frequencies, the proximity position is determined. An input device 100 can be provided that, when the length between the first end 131 and the second end 132 of the transmission path 130 is λg / 2 or more, detects the position of the operation input by performing an inverse Fourier transform on the multiple voltage reflection coefficients calculated with respect to the multiple frequencies.

[0174] Alternatively, the signal generator 110 can output waveform signals at multiple frequencies, and the position determination unit 171 calculates voltage reflection coefficients at each of the multiple frequencies based on a first signal level of a standing wave generated based on the input signal and the reflected signal, and a second signal level whose phase differs from the first signal level by π / 2. The unit then performs an inverse Fourier transform on the multiple voltage reflection coefficients calculated with respect to the multiple frequencies to determine the proximity position. This provides an input device 100 that can detect the position of an operation input by performing an inverse Fourier transform on multiple voltage reflection coefficients calculated with respect to multiple frequencies when the length between the first end 131 and the second end 132 of the transmission path 130 is λg / 2 or more.

[0175] Alternatively, the characteristic impedance of the transmission path 130 can be equal to the resistance value of the terminating resistor 140 (terminal section). Since reflections can be suppressed at the end of the transmission path 130, a suitable output can be obtained even when no operational input is being performed.

[0176] Alternatively, the waveform signal can be a sine wave signal. An input device 100 can be provided that can detect the position of an operational input based on an incident signal and a reflected signal composed of a sine wave signal.

[0177] Alternatively, the waveform signal can be a rectangular wave signal. An input device 100 can be provided that can detect the position of an operational input based on an incident signal and a reflected signal composed of a rectangular wave signal.

[0178] Alternatively, multiple frequency waveform signals can be implemented using chirped signals. An input device 100 can be provided that, when the length between the first end 131 and the second end 132 of the transmission path 130 is λg / 2 or more, uses chirped signals to detect the position of an operational input.

[0179] The above describes the input device of an exemplary embodiment of the present disclosure. However, the present disclosure is not limited to the specific embodiments disclosed, and various modifications and alterations can be made without departing from the claims.

[0180] Furthermore, this international application claims priority based on Japanese Patent Application No. 2023-149515, filed on September 14, 2023, the entire contents of which are incorporated herein by reference.

[0181] Symbol Explanation

[0182] 100 Input Device

[0183] 110 Signal Generator

[0184] 120 Circulator (an example of a line connector)

[0185] 120A Directional Coupler (An Example of a Line Connector)

[0186] 121 Terminal 1

[0187] 122 Terminal 2

[0188] 123 Terminal 3

[0189] Transmission paths for 130, 130A~130Q, and 130M1~130M2

[0190] 131 First End

[0191] 132 End 2

[0192] 140 Terminating Resistor (An Example of a Terminating Part)

[0193] 150 phase shifter

[0194] 160A mixer (an example of the first mixer)

[0195] 160B mixer (an example of the second mixer)

[0196] 170 Control device

[0197] 171 Location Determination Department.

Claims

1. An input device comprising: a signal generator that generates a wave signal; a transmission path that has a first end connected to the signal generator and a second end on the opposite side of the first end, and that transmits the wave signal; a terminal portion connected to the second end of the transmission path; and a position determination portion that determines a position of approach of an object to the transmission path based on an input signal that is the wave signal input from the signal generator to the transmission path, and a reflection signal that is the input signal reflected to the first end side due to the object approaching the transmission path between the first end and the second end of the transmission path.

2. The input device according to claim 1, wherein the position determination portion determines the position of approach based on a first signal level related to a reflection signal component of a standing wave generated based on the input signal and the reflection signal, and a second signal level related to the reflection signal component of the standing wave that is different in phase from the first signal level by π / 2.

3. The input device according to claim 2, wherein the input device further comprises: a line connector that has a first terminal connected to the signal generator, a second terminal connected to the transmission path, and a third terminal, and that outputs the reflection signal from the third terminal, with an interval between the first terminal and the second terminal being inserted between the signal generator and the transmission path; a first mixer that has two input terminals connected to the signal generator and the third terminal, and that mixes the input signal and the reflection signal component of the standing wave to output the first signal level; a phase shifter connected to the signal generator that shifts the phase of the input signal by π / 2 and outputs; and a second mixer that has two input terminals connected to the phase shifter and the third terminal, and that mixes the input signal whose phase is shifted by π / 2 by the phase shifter and the reflection signal component of the standing wave to output the second signal level, the position determination portion determines the position of approach based on the first signal level output from the first mixer and the second signal level output from the second mixer.

4. The input device according to any one of claims 1 to 3, wherein if a wavelength of an electric wave in a frequency of the wave signal is λ, a length between the first end and the second end of the transmission path is less than λg / 2.

5. The input device according to any one of claims 1 to 4, wherein the signal generator is capable of outputting the wave signal of a plurality of frequencies, the position determination portion calculates a voltage reflection coefficient based on a first signal level of a standing wave generated based on the input signal and the reflection signal, and a second signal level that is different in phase from the first signal level by π / 2, for each of the plurality of frequencies, and determines the position of approach using a plurality of the voltage reflection coefficients calculated for the plurality of frequencies.

6. The input device according to any one of claims 1 to 4, wherein ​ The signal generator can output the waveform signal of a plurality of frequencies, The position determining section determines the approach position by calculating the voltage reflection coefficient from a first signal level of a standing wave generated based on the input signal and the reflected signal, and a second signal level of a phase differing from the first signal level by π / 2, for each of the plurality of frequencies, and performing inverse Fourier transform on the plurality of voltage reflection coefficients calculated for the plurality of frequencies.

7. The input device according to any one of claims 1 to 6, wherein The characteristic impedance of the transmission path is equal to the resistance value of the terminal section.

8. The input device according to any one of claims 1 to 7, wherein The waveform signal is a sine wave signal.

9. The input device according to any one of claims 1 to 7, wherein The waveform signal is a rectangular wave signal.

10. The input device according to claim 5 or 6, wherein The waveform signal of the plurality of frequencies is implemented by a chirp signal.

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