JP2009237856A - Touch panel device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a touch panel device having excellent water resistance/hygienic characteristics. <P>SOLUTION: This touch panel device has: an operation part 54 having a plurality of input operation faces; a transmission part 51 having a transmission antenna transmitting an electric wave beam; a reception part 53 having a plurality of reception antennas receiving the electric wave beam emitted from the transmission antenna, and a plurality of diodes each detecting a current component flowing through each of the plurality of reception antennas; and a control part 53 deciding that a finger of a user contacts or approaches the operation part 54 based on detection results (reception power) of the plurality of diodes, and performing output to the outside. In the touch panel device, the operation part 54 is disposed on radiative lines of the electric wave beam toward the reception antennas from the transmission antenna, and the control part 53 decides that the finger of the user contacts or approaches the input operation face on a distant side to a front edge of the operation part 54 when the current components flowing through at least two of the plurality of reception antennas corresponding to the plurality of input operation faces become a prescribed threshold value or below. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a touch panel device using a radio wave beam.

  A conventional touch panel device is mainly provided with a sensing unit in an operation unit having at least one input operation surface to specify the position of a finger to be operated. For example, there is a method in which a resistance film is formed on the operation portion and the contact position is specified from a change in resistance value, and an electrode is formed on substantially the entire surface of the operation portion and the contact position is specified from a change in capacitance coupling. There is also a method of specifying the position of a finger to be operated without providing a sensing means in the operation unit. For example, there is a system in which a plurality of infrared light projecting elements and light receiving elements are arranged around the input operation surface and on the upper side so as to face each other, and a contact position is specified from a position shielded by an operating finger.

JP 2005-135329 A

  In the case of a touch panel device that has a sensing means in the operation unit and identifies the position of a finger to be operated, since the electric circuit is formed on the input operation surface, the use environment is limited and it is difficult to install it in a place where water is used. is there. In addition, in the case of a touch panel device that uses a photoelectric sensor (infrared sensor) to specify the position of a finger to be operated without providing a sensing means in the operation unit, steam generated in the bathroom when installed in a high humidity environment such as a bathroom False detection may occur due to condensation. In addition, since the input operation surface is installed in a place that is one step lower, water scattered when installed in a place where water is used such as a washroom or kitchen tends to accumulate on the outer periphery of the input operation surface, causing scale and mold generation. Poor hygiene.

  Accordingly, an object of the present invention is to provide a touch panel device excellent in water resistance and hygiene.

In order to achieve the above object, an invention according to claim 1 is directed to an operation unit having a plurality of input operation surfaces, an oscillation circuit for generating a high-frequency signal, and radiating the high-frequency signal generated by the oscillation circuit as a radio wave beam. Transmitting antennas, a plurality of receiving antennas for receiving radio beams radiated from the transmitting antenna, a plurality of diodes connected to the plurality of receiving antennas and detecting current components flowing through the receiving antennas, Based on the detection result (received power) of the diode, a control unit that determines that the user's finger is in contact with or close to the operation unit;
An output unit that outputs the determination result of the control unit to the outside, wherein the operation unit is disposed on radiation of a radio wave beam from the transmission antenna toward the reception antenna, wherein the plurality of input operations When the current component flowing in at least two of the plurality of receiving antennas corresponding to the surface is equal to or less than a predetermined threshold, the control unit is placed on the input operation surface farther from the front edge of the operation unit. It is characterized in that it is determined that the finger is touched or approached to the vicinity.

  ADVANTAGE OF THE INVENTION According to this invention, the touchscreen apparatus excellent in water resistance and hygiene can be provided.

Hereinafter, the touch panel device according to the present invention will be described with reference to the drawings.
In the following examples, the thickness of the substrate and the pattern dimensions in the drawings are different from actual shapes for convenience of explanation.
FIG. 1 is a block diagram showing a first embodiment of a touch panel device according to the present invention. FIG. 2 is a side view of the same.

  The touch panel device of the present invention includes an operation unit 54, a transmission unit 51, a reception unit 52, and a control unit 53. The operation unit 54 includes at least one input operation surface 31 that can be recognized by a user on one surface side of a base material made of a dielectric (resin or ceramic). The transmission unit 51 includes an oscillation circuit that generates a high-frequency signal and a transmission antenna that radiates the high-frequency signal generated by the oscillation circuit as a radio wave beam. The receiving unit 52 includes at least one receiving antenna that receives a radio beam radiated from the transmitting antenna, and a diode that is connected to the receiving antenna and detects a current flowing through the receiving antenna. The control unit 53 amplifies the detection signal detected by the diode so that it can be easily amplified and compared, and a user's finger inputs an operation based on the amplified detection signal. An operation determination circuit (CPU: configured using a central processing unit) that determines that the surface 31 is in contact with or close to the surface 31 and a drive signal and an operation for driving a load according to the determination result of the operation determination circuit An output circuit is provided for outputting a notification signal for notifying the user of the confirmation to the outside by wire or wirelessly.

In the touch panel device illustrated in FIG. 2, an operation unit 54 is disposed on the radiation of the radio wave beam from the transmission unit 51 toward the reception unit 52. The back side (finger) of the concealment base 32 made of a dielectric (resin or earthenware) disposed on the back side of the input operation surface 31 (opposite to the entry direction of the finger to be operated) and substantially perpendicular to the operation unit 54. The transmitting unit 51 (transmitting antenna) is inclined and installed on the surface not facing the surface. The transmission unit 51 shown in FIG. 3 has a thin-film rectangular transmission electrode 12 acting as a transmission antenna formed on one surface of a first substrate 11 in which a layered first ground electrode 13 is formed on substantially the entire surface. Yes. On the other surface of the first substrate 11, a metal case 16 is provided with a frequency adjusting means (screw) (not shown) for shielding unnecessary electromagnetic waves and causing the top surface facing the first substrate 11 to oscillate at a predetermined frequency. And an oscillation circuit (generating a high-frequency signal using a field effect transistor and a dielectric resonator or generating a high-frequency signal using a Gunn diode) (not shown) is formed therein. A high-frequency signal generated by an oscillation circuit (not shown) is transmitted to the transmission electrode 12 through the conduction hole 15 penetrating the surface of the first substrate 11 and is emitted from the transmission electrode 12 as a radio wave beam. The conduction hole 15 is provided inside the transmission electrode 12 having an impedance of 50Ω. The transmission electrode 12 is a wavelength of a high-frequency signal propagating through the first substrate 11 (λg / 2: λg...) Of a high-frequency signal (operating frequency). When the relative permittivity of the first substrate 11 is εr, it is a rectangular thin film electrode having a length L1 of at least one side of λ = εr ^1/2 · λg, and the first ground electrode 13 is a reflector. It is a transmission antenna of the microstrip structure which acts as. Therefore, the radio wave beam radiated from the transmission electrode 12 is forward (with respect to the first ground electrode 13, the transmission electrode 12 with respect to the first ground electrode 13). The radio wave beam can be efficiently radiated in the direction in which the is formed. The radiation shape of the radio wave beam at this time is as shown in FIG. 4, where the half-value angle of the AA ′ plane parallel to the excitation direction is θ1, and the half-value angle of the BB ′ plane orthogonal to the excitation direction is θ2. An elliptical shape having a long diameter in the direction parallel to the excitation direction θ1> θ2. Here, the substantially vertical direction is a range of ± 5 °, and considering the radiation characteristics of the radio wave beam, the vertical direction can be regarded as ± 5 °.

  On the back surface of the operation unit 54 (the surface that does not face the finger), a receiving unit 52 is provided in parallel with the input operation surface 31 with a space. In the receiving section 52 shown in FIG. 5, thin-film rectangular receiving electrodes 22a and 22b that function as receiving antennas are formed on one surface of a second substrate 21 in which a layered second ground electrode 23 is formed on substantially the entire surface. Has been. The cathode terminal of the diode 24 is connected to one end of the receiving electrode 22a, and the anode terminal of the diode 24 is connected to one end of the receiving electrode 22b facing the one end of the receiving electrode 22a. The length L2 of one side in the excitation direction of the receiving electrodes 22a and 22b is about a quarter wavelength of the high-frequency signal in consideration of the relative dielectric constant of the second substrate 21. The receiving electrode 22a and the receiving electrode 22b connected in this manner are one receiving antenna having a dipole antenna structure. The anode terminal of the diode 24 is connected to the second ground electrode 23 through the conduction hole 25a, and the cathode terminal is connected to the control unit 53 formed on the other surface of the second substrate 21 through the conduction hole 25b.

Since the radio wave beam has a property of passing through a dielectric member such as resin or ceramic, the input operation surface is concealed behind the base made of resin or ceramic. A finger that is in contact with or close to 31 can be detected.
In addition, an electrode for recognizing changes in capacitance is placed behind a substrate made of resin or earthenware, and it is easy to detect a finger that touches or approaches the input operation surface from the change in electrode capacitance. However, the thickness of the substrate may be about several millimeters, but the capacitance change rate decreases as the thickness increases. In addition, it is sufficient if the back surface of the base material is flat, but if it is installed on a back surface with an uneven surface, such as pottery, the rate of change in capacitance varies depending on the location, so that erroneous detection may occur. Since the transmission characteristics of the radio wave beam are hardly affected by the thickness of the base material and the unevenness of the base material surface, it can be easily determined that the user's finger is in contact with or close to the input operation surface 31.

  On the other hand, as long as a radio wave beam is used, it does not mean that any sensing form is acceptable. When a Doppler sensor capable of detecting a moving object by transmitting and receiving radio beams and detecting the Doppler effect is installed on the back of the operation unit 54, the voltage amplitude value of the Doppler signal decreases when the speed of the operated finger is extremely slow. Since the state cannot be detected, it is not suitable for the sensing means of the touch panel device.

If the interval between the input operation surfaces on which one or more input operation surfaces 31 are arranged is wide to some extent, both the transmission unit 51 and the reception unit 52 are installed on the back surface of the operation unit 54 to emit a radio wave beam from the transmission unit 51. When the radio wave beam reflected and returned from the finger on the operation unit 54 is received by the receiving unit 52, it can be easily determined that the user's finger has touched or approached the input operation surface 31.
However, in the case of a touch panel device in which a plurality of input operation surfaces are arranged in a relatively narrow range, the amount of reflection of the radio wave beam reflected from the finger varies depending on the approach angle and size of the finger, so that the user's finger touches or is near It is difficult to accurately identify the input operation surface that is close to

  In the touch panel device of the present invention, since the operation unit 54 is arranged on the radiation of the radio wave beam from the transmission unit 51 to the reception unit 52, the operation is detected by the diode 24 when no finger is operated on the operation unit 54. The received signal (received power) increases. On the other hand, when a finger to be operated enters the operation unit 54, the current flowing through the reception antenna (reception electrodes 22a and 22b) decreases, and the reception signal (reception power) detected by the diode 24 decreases. Therefore, if a decrease in the voltage value of the received signal detected by the diode 24 (decrease in received power) is detected, it is confirmed that the user's finger is in contact with or close to the input operation surface 31 provided in the operation unit 54. Easy to judge. In addition, since only the receiving antenna needs to be installed at a paired position in accordance with the arrangement and quantity of the input operation surface, even in the case of a touch panel device in which a plurality of input operation surfaces are arranged in a relatively narrow range, the user It is possible to accurately identify the input operation surface where the finger is in contact or close to the vicinity. In consideration of efficiently blocking the radio wave beam radiated from the transmitting antenna, the electrode shape of the receiving electrodes 22a and 22b is shorter than the finger width (about 1 cm) in the length of the edge perpendicular to the excitation direction. It is preferable.

  The touch panel device according to the present invention has an input operation surface based on a received signal detected by receiving a radio wave beam radiated from a transmitting antenna by installing at least a receiving unit 52 (receiving antenna) on a back surface of a dielectric base. Since it is possible to easily determine a finger that is in contact with or close to 31, the water resistance is excellent. Moreover, since the operation part 54 and its circumference | surroundings are substantially flat, it is excellent in cleaning property, and since there is no place where water retains, it is excellent in hygiene. In addition, since the sensing means is not exposed to the operation unit 54 and its periphery, it is possible to prevent damage due to external impact.

  Since one wavelength of the photoelectric beam emitted from the photoelectric sensor is relatively short (infrared is about several nanometers), and the photoelectric beam emitted from the light projecting element has a small directivity and high straightness, the light projecting element and the light receiving element Must be arranged in pairs. One wavelength of the radio wave beam is extremely long with respect to the photoelectric beam. For example, if the frequency of a high-frequency signal that becomes a radio wave beam is 10.50 to 10.55 GHz, one wavelength is about 28 millimeters, and the radio wave beam radiated from the transmitting antenna has a large directivity angle and is radiated over a wide range. Accordingly, when the operation unit 54 includes a plurality of input operation surfaces, the structure and electrode shape of the transmission antenna can be changed with respect to the reception antennas disposed in pairs in accordance with the arrangement and quantity of the input operation surfaces. A radio wave beam can be radiated from one transmitting antenna to a plurality of receiving antennas, and a touch panel device can be provided with a simple configuration.

  In the touch panel device of the present invention, the transmission antenna provided in the transmission unit 51 and the reception antenna provided in the reception unit 52 are both vertically polarized, but the shapes of the transmission electrode 12 and the reception electrodes 22a and 22b are different. Yes. Since the receiving antenna having a pair of receiving electrodes 22a and 22b has a dipole antenna structure in which the electrode shape is short in the length of the end perpendicular to the excitation direction, the receiving direction of the finger entering from the front edge of the operation unit 54 If the receiving antenna is installed on the back of the operation unit 54 so that the excitation direction of the receiving antenna is substantially parallel, that is, the excitation direction of the receiving antenna (receiving electrode) is substantially orthogonal to the front edge of the operation unit 54, Thus, even if the size of the finger fluctuates, radio wave beams radiated from the transmitting antenna to the receiving antenna can be blocked at substantially the same rate, and detection accuracy can be improved. In addition, even if the receiving electrode is enlarged in a region where the excitation frequency of the receiving antenna is relatively low, the radio wave beam radiated from the transmitting antenna toward the receiving antenna can be blocked with a finger. The front edge of the operation unit 54 does not necessarily have to be a straight line and may be a circular arc. At that time, the tangent of the arc and the excitation direction of the receiving antenna are substantially orthogonal. Here, being substantially orthogonal to the front edge of the operation unit 54 indicates a range of 90 ° ± 10 °.

  The receiving antenna having a pair of receiving electrodes 22a and 22b formed on one surface of the second substrate 21 has a microstrip structure in which the second ground electrode 23 formed inside the second substrate 21 acts as a reflector. Therefore, although it is a dipole antenna, it is not omnidirectional and can efficiently receive a radio wave beam incident from the front (the direction in which the receiving electrodes 22a and 22b are formed with respect to the second ground electrode 23). Further, by forming the second ground electrode 23 on the entire surface of the second substrate 21 or on the other surface, a plurality of reception antennas (reception electrodes) are provided at a pair of positions according to the arrangement and quantity of the input operation surface. Even when is placed, the wraparound of the radio wave beam from behind (the direction in which the second ground electrode 23 is formed with respect to the receiving electrode) can be suppressed, and the position of the finger can be specified with high accuracy.

    In the touch panel device according to the present invention, the excitation frequency of the transmission antenna provided in the transmission unit 51 and the reception antenna provided in the reception unit 52 are the same, but the excitation frequency of the reception antenna is VSWR ( If the frequency band is such that the standing wave ratio) <1, the sensing performance is hardly affected even if the excitation frequencies are different. Therefore, if the excitation frequency of the receiving antenna is set higher than the frequency of the high-frequency signal, it is possible to provide a touch panel device that can reduce the size of the receiving antenna and has high resolution.

  Since the touch panel device of the present invention includes the receiving unit 52 and the control unit 53 integrally on the second substrate 21, it is excellent in noise resistance, easy to handle, and excellent in workability. On the other hand, it is not necessarily integral, and can be changed according to the installation space. For example, the amplifier circuit may be disposed on the second substrate 21 and the operation determination circuit and the output circuit may be formed on another substrate.

  The operation determination circuit provided in the control unit 53 has the user's finger on the input operation surface 31 according to the input timing or input period of the received signal input to the input port of the microcomputer (CPU) directly or via the comparator. What is necessary is just to judge that it contacted or approached near. When the operation unit 54 includes a plurality of input operation surfaces and a plurality of receiving antennas that are paired with the input operation surface are arranged at relatively narrow intervals, or when the thickness of the base material of the operation unit 54 is not constant, the CPU A received signal detected by a diode may be input to an AD conversion function port having a function of converting an analog voltage into a digital voltage and compared. Although not described in the present embodiment, the control unit 53 can incorporate a high-frequency / low-frequency filter circuit that extracts only necessary frequency components before the operation determination circuit, if necessary.

FIG. 6: is (a) front view, (b) side view, (c) top view which shows 2nd Embodiment of the touchscreen apparatus in this invention. FIG. 7 is a graph showing a voltage waveform input to the operation determination circuit.
Hereinafter, description of the description of the part which overlaps with the Example mentioned above is abbreviate | omitted.
The touch panel device shown in FIG. 6 includes an operation unit 54 in which a plurality of input operation surfaces 31a, 31b, 31c, and 31d that can be recognized by the user are arranged on one surface side of a base material made of a dielectric material (resin or earthenware). ing. Assuming that the entry direction side of the finger entering the operation unit 54 is the front edge of the operation unit 54, the operation unit 54 is directed from the front edge toward the back side, the input operation surface 31d, the input operation surface 31c, the input operation surface 31b, and the input operation surface. They are arranged on a straight line in the order of 31a. A transmission unit 51 including a transmission antenna (transmission electrodes 12a and 12b) that radiates a radio wave beam forward is provided on the back side and the upper side of the input operation surface 31a. A receiving unit 52 having a plurality of receiving antennas (receiving electrodes 22a, 22b, 22c, 22d, 22e, 22f, 22g, and 22h) that receive the radio wave beam radiated from is installed.

  The transmission unit 51 is different in transmission antenna from the transmission unit 51 shown in FIG. 8 includes a transmission electrode 12a and a transmission electrode 12b formed on one surface of the first substrate 11 so that end surfaces orthogonal to the excitation direction face each other, and the transmission line 17 serving as a power equal distribution circuit. Are connected to each other, and a conduction hole 15 connected to an oscillation circuit (not shown) formed on the other surface of the first substrate 11 is formed at a branch point of the transmission line 17. The length of the transmission line 17 from the conduction hole 15 to the transmission electrode 12b is longer than the length of the transmission line 17 from the conduction hole 15 to the transmission electrode 12a, and the timing at which the high-frequency signal is propagated to the transmission electrode 12b with respect to the transmission electrode 12a. (Phase) is delayed by 90 to 110 degrees. Therefore, the maximum intensity radiation direction of the radio wave beams emitted and integrated from the transmission electrodes 12a and 12b is inclined downward (A ') in the figure as shown in FIG. The radiation shape of the radio wave beam radiated from the transmitting antenna at this time is θ1 when the half-value angle of the AA ′ plane parallel to the excitation direction is θ1, and the half-value angle of the BB ′ plane orthogonal to the excitation direction is θ2. It becomes an elliptical shape with a long diameter in the direction parallel to> θ2 and the excitation direction. In the touch panel device shown in FIG. 2, the transmitter 51 is installed obliquely with respect to the concealing base material 32 and the radio wave beam is radiated in a substantially vertical direction with respect to the surface of the first substrate 11. In the illustrated touch panel device, the transmitting unit 51 is installed in parallel to the concealing base material 32, and the radio wave beam is radiated from the substantially vertical direction toward the obliquely lower side with respect to the surface of the first substrate 11. In this way, the radiation shape of the radio wave beam radiated from the transmission unit 51 (transmission antenna) is arbitrarily changed by changing the structure of the transmission antenna (shape, quantity and arrangement of the transmission electrode) unlike the photoelectric sensor using infrared rays. Can be set. Therefore, the transmission antenna can be easily installed in a narrow space.

  Further, as a structure in which the radio wave beam is directed obliquely downward from the substantially vertical direction with respect to the surface of the first substrate 11, a transmission antenna adopting a spatial beam forming system as shown in FIG. 10 is also conceivable. One surface of the first substrate 11 includes a feeding element 12 to which a high-frequency signal generated by an oscillation circuit is directly supplied, and a parasitic element 18 that is excited when the feeding element 12 is excited to act as a waveguide. Are formed at a predetermined interval so that the end face orthogonal to the excitation direction of the feed element 12 and the end face of the parasitic element 18 face each other. Compared with the transmission antenna shown in FIG. 9, the transmission line 17 is not required, so that the transmission antenna can be miniaturized, and the radio wave beam can be obtained with a wider half-value angle θ1 in the direction parallel to the excitation direction (vertical direction in the figure). Can be emitted obliquely downward, so that the installation range of the input operation surface arranged in the operation unit 54 can be expanded.

  Similarly, the reception pattern for receiving a radio wave beam can be changed for the receiving antenna, and if the maximum intensity receiving direction is set so as to oppose the radiation direction of the radio wave radiated from the transmitting antenna, input operation can be performed. The difference in the amount of current flowing through the receiving antenna can be increased when a finger is present on the surface and when it is not present, so that the user's finger can be touched or approached the input operation surface more accurately. it can.

  The receiving unit 52 has a pair of receiving electrodes 22a and 22b corresponding to the input operation surface 31a and a pair of receiving electrodes corresponding to the input operation surface 31b having a dipole structure that acts as a receiving antenna on one surface of the second substrate 21. 22c and 22d, a pair of receiving electrodes 22e and 22f corresponding to the input operation surface 31c, and a pair of receiving electrodes 22g and 22h corresponding to the input operation surface 31d are formed. A diode 24a is connected to the receiving electrodes 22a and 22b, a diode 24b is connected to the receiving electrodes 22c and 22d, a diode 24c is connected to the receiving electrodes 22e and 22f, and a diode 24d is connected to each of the receiving electrodes 22g and 22h. , 24b, 24c, and 24d are transmitted to the controller 53 provided on the other surface of the second substrate 21.

  Since the radio wave radiated from the transmission antenna has a relatively long wavelength, for example, if the frequency of the high-frequency signal is 10.50 to 10.55 GHz, one wavelength is about 28 millimeters, and is about 14 mm in front of the transmission antenna. The region where the radio wave radiation intensity changes from zero to the maximum occurs continuously. For this reason, when a plurality of receiving antennas are appropriately arranged at equal intervals, the received signals (received power) detected by the diodes 24a, 24b, 24c, and 24d vary, and a finger operated on the operation unit 54 is When it does not exist, a place where the voltage value level of the received signal is already high and a place where the voltage value is low occur (FIG. 7, CASE 1). For this reason, when the finger enters the operation unit 24, it is impossible to accurately determine which input operation surface 31a, 31b, 31c, 31d is touched.

  By arranging a plurality of receiving antennas at positions where the distance from the center of the transmitting antenna to the centers of the plurality of receiving antennas is approximately 1 / n wavelength of the high-frequency signal × m (n · m: integer) When there is no finger to operate on the operation unit 54, the voltage value level (received power intensity) of the received signal of each receiving antenna can be made substantially the same. For example, in FIG. 7, CASE 2 converts an electric current detected by each of the diodes 24a, 24b, 24c, and 24d into a voltage value when a plurality of receiving antennas are arranged for each half wavelength from the transmitting antenna, and an amplification circuit. Shows the voltage waveform after amplification. Therefore, it is possible to accurately determine which input operation surface 31 is touched when the finger enters the operation unit 24. The center of the transmission antenna in the present embodiment is an intermediate point from the center of the end surface of the transmission electrode 12a facing the transmission electrode 12b to the center of the end surface of the transmission electrode 12b facing the transmission electrode 12a. The center of the receiving antenna is the center of the plurality of diodes 24a, 24b, 24c, and 24d connected to the plurality of receiving electrodes 22a, 22b, 22c, 22d, 22e, 22f, 22g, and 22h, respectively.

  The receiver electrode 22a, the receiver electrode 22b and the diode 24a described in this embodiment are the receiver 2a, the receiver electrode 22c, the receiver electrode 22d and the diode 24b are the receiver 2b, and the receiver electrode 22e, the receiver electrode 22f and the diode 24c are the receiver 2c. When the receiving electrode 22g, the receiving electrode 22h, and the diode 24d are used as the receiver 2d, a plurality of receivers 2a, 2b, 2c, and 2d are formed on one surface of the second substrate 21 at different intervals. Input operation surfaces 31a, 31b, 31c, 31d are arranged at equal intervals above 2b, 2c, 2d. An electrode pattern including at least the other end of the receiving electrode 22a is provided below the input operation surface 31a, and an electrode pattern including at least the other end of the receiving electrode 22c is provided below the input operation surface 31b. An electrode pattern including at least the other end of the receiving electrode 22e is disposed on the lower side, and an electrode pattern including at least the other end of the receiving electrode 22g is disposed on the lower side of the input operation surface 31d. At this time, the excitation directions of the receiving electrodes 22 a, 22 b, 22 c, 22 d, 22 e, 22 f, 22 g, and 22 h are substantially orthogonal to the front edge of the operation unit 54. If the receiving antenna is arranged so that at least the electrode pattern including the end face of the receiving antenna close to the transmitting antenna is positioned below the input operation surface, the finger enters from the front edge of the operation unit 54 and the input operation surfaces 31a and 31b. , 31c and 31d, the radio wave beam radiated from the transmitting antenna can be blocked by the input operation surface portion touched by the finger. For example, FIG. 7, CASE 3 shows a voltage waveform after the current detected by each of the receivers 2a, 2b, 2c, and 2d is converted into a voltage value and amplified by an amplifier circuit when a finger is brought into contact with the input operation surface 31d. Indicates.

  Similarly, a voltage waveform when a finger is brought into contact with the input operation surface 31a is shown in FIG. The voltage value level decreases not only on the input operation surface 31a but also on the input operation surfaces 31b, 31c, and 31d. The decrease in the voltage value level on the input operation surface 31a is the blocking of the radio wave beam by the fingertip, but the decrease in the voltage value level on the input operation surfaces 31b, 31c, 31d is because the radio wave beam is blocked by the back of the hand from the vicinity of the finger joint. Occurs. Accordingly, a threshold is set for a value obtained by converting the current detected by each receiver 2a, 2b, 2c, 2d into a voltage value, and when there are a plurality of receivers that are equal to or less than the threshold, the control unit 53 If it is determined that the user's finger is in contact with or close to the input operation surface on the side far from the front edge of the operation unit 54 in the operation determination circuit provided in FIG. The position of the fingertip can be specified with high accuracy.

  If a Doppler sensor that transmits / receives a radio beam to / from the transmission unit 51 to detect a moving body in front and outputs a Doppler signal is used, a finger enters the operation unit 54 and enters any of the input operation surfaces 31a, 31b, 31c, and 31d. Since it can be easily recognized that the movement temporarily stops when the finger comes in contact, it is not necessary to identify whether or not the operation is performed in the time of contact with the input operation surfaces 31a, 31b, 31c and 31d, and the responsiveness is improved. To do.

  In the present embodiment, the plurality of receivers 2a, 2b, 2c, and 2d are formed on the same substrate surface. However, the plurality of receivers 2a, 2b, 2c, and 2d are formed on separate substrates, and the back of the operation unit 54 is formed. The installation height may be changed for each receiver, and in that case, the same effect can be obtained.

  As mentioned above, although embodiment of this invention was described, this embodiment is only the illustration for description of this invention, and is not the meaning which limits the scope of the present invention only to this embodiment. The present invention can be implemented in various other modes without departing from the gist thereof.

1 is a block diagram illustrating a first embodiment of a touch panel device according to the present invention. FIG. It is (a) front view and (b) A-A 'sectional drawing which show the structure of the transmission part in 1st Embodiment. It is a graph which shows the radiation pattern of the radio wave beam radiated | emitted from the transmission part in (a) A-A 'cross section and (b) B-B' cross section. It is (a) front view and (b) A-A 'sectional drawing which show the structure of the receiving part in 1st Embodiment. It is (a) front view, (b) side view, (c) top view which shows 2nd Embodiment of the touchscreen apparatus in this invention. 4 is a graph showing a voltage waveform input to the operation determination circuit. It is a front view which shows the structure of the transmission part in 2nd Embodiment. It is a graph which shows the radiation pattern of the radio wave beam radiated | emitted from the transmission part in (a) A-A 'cross section and (b) B-B' cross section. It is a front view which shows the modification of the transmission part in 2nd Embodiment. It is a graph which shows the radiation pattern of the radio wave beam radiated | emitted from the transmission part in (a) A-A 'cross section and (b) B-B' cross section.

Explanation of symbols

11 First substrate 12, 12a, 12b Transmitting electrode (feeding element)
DESCRIPTION OF SYMBOLS 13 1st ground electrode 15 Conductive hole 16 Metal case 17 Transmission line 18 Parasitic element 21 2nd board | substrate 22a-22h Reception electrode 23 2nd ground electrode 24a-24d Diode 25a, 25b Conductive hole 31, 31a-31d Input operation surface 32 Concealment substrate 51 Transmitter 52 Receiving unit 53 Control unit 54 Operation unit

Claims (1)

An operation unit having a plurality of input operation surfaces;
An oscillation circuit for generating a high-frequency signal;
A transmission antenna that radiates a high-frequency signal generated by the oscillation circuit as a radio wave beam;
A plurality of receiving antennas for receiving radio wave beams radiated from the transmitting antenna;
A plurality of diodes connected to the plurality of receiving antennas and detecting a current component flowing through the receiving antenna;
Based on the detection results (received power) of the plurality of diodes, a control unit that determines that a user's finger is in contact with or close to the operation unit;
An output unit for outputting the determination result of the control unit to the outside,
A touch panel device in which the operation unit is arranged on radiation of a radio wave beam from the transmitting antenna toward the receiving antenna,
When the current component flowing in at least two of the plurality of receiving antennas corresponding to the plurality of input operation surfaces is equal to or less than a predetermined threshold, the control unit is configured to input the input farther from the front edge of the operation unit. A touch panel device characterized by determining that a user's finger is in contact with or close to the operation surface.

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