This application claims benefit of Japanese Patent Application No. 2011-204165 filed on Sep. 20, 2011, which is hereby incorporated by reference in its entirety.
1. Field of the Disclosure
The present disclosure relates to an input detection device with which a comparatively large detection output can be obtained when an input unit is operated and with which both input detection and generation of vibrations can be performed using a common coil.
2. Description of the Related Art
An electrostatic capacitive sensor in which electrode units are respectively provided on the opposing portions of two substrates is disclosed in Japanese Unexamined Patent Application Publication No. 6-314163.
In the electrostatic capacitive sensor, when the distance between the opposing electrode units changes or the opposing area of the electrodes changes based on an operation of an input unit, the change is detected by a fluctuation in the electrostatic capacitance.
In the electrostatic capacitive sensor described in Japanese Unexamined Patent Application Publication No. 6-314163 and the like, since the fluctuation in the detection output with respect to a change in the distance between the electrodes or a change in the opposing area is extremely small, the electrostatic capacitive sensor is easily influenced by external noise, and it is difficult to detect miniscule changes with high accuracy.
Further, while the electrostatic capacitive sensor described in Japanese Unexamined Patent Application Publication No. 6-314163 and the like can obtain a detection output from operating the input unit, it is not possible for the sensor itself to generate vibrations for feedback or the like, and in order to generate vibrations, it is necessary to provide vibration generation means separately from the sensor.
An input detection device includes: a coil; a conductive induction member that is provided in proximity to the coil; a driving circuit that applies an alternating detection current to the coil; a detection circuit that detects the power that is inducted to the induction member by a counter-electromotive force when the detection current is applied to the coil; and an input unit that increases or decreases the power that is obtained from the induction member.
The input detection device of the present invention inducts the counter-electromotive force when an alternating detection current is applied to the coil to the induction member, and changes the inductive force using the input unit. It is thereby possible to extract a comparatively large change in the power when the input unit is operated, which improves detection precision and resistance to the influence of external noise.
An input detection device 1 of a first embodiment illustrated in
A driving circuit 5 is provided to the input detection device 1. In the driving circuit 5, a first end portion 2a of the wiring that configures the coil 2 is connected to a connection terminal 6 to which a direct current of 3 V is applied. Further, a Zener diode 7 that is parallel with the coil 2 is provided so that the voltage that is applied to the coil 2 is stabilized.
A transistor 8 that functions as a switch element is provided on the driving circuit 5. A second end portion 2b of the wiring that configures the coil 2 is connected to a collector terminal of the transistor 8. A diode 9 for neutralizing the induction of power due to a counter-electromotive force in one direction is provided to the transistor 8.
An end portion of the induction member 3 is connected to an input unit 10 via a lead line 3a. The input unit 10 includes a first electrode 11 and a second electrode 12. The lead line 3a is connected to the first electrode 11. The first electrode 11 and the second electrode 12 are formed of a low-resistance conductive material such as a printed layer of a copper sheet, copper foil, or silver paste. The first electrode 11 and the second electrode 12 are both plate-like and face each other to be parallel with a distance therebetween, and in the input unit 10, at least one of a distance d and an facing area A of both electrodes 11 and 12 can be changed by an operating force from the outside.
A detection circuit 20 is connected to the second electrode 12. A voltage amplification unit 21 and a peak holding unit 22 are provided on the detection circuit 20.
The operation of the input detection device 1 will be described with reference to the waveform view of
As illustrated in
With the detection current Ia illustrated in
While a counter-electromotive force is generated on the coil 2 from the first end portion 2a toward the second end portion 2b when the reverse direction current 12 begins to flow through the coil 2, since the conductive induction member 3 is in proximity with the coil 2, as illustrated in
Since the size of the current that flows through the coil 2 is comparatively large, an induction power E1 with a large voltage of equal to or greater than 1 V or even equal to or greater than 2 V can be inducted to the induction member 3.
The induction power E1 that is inducted to the induction member 3 is led to the first electrode 11 of the input unit 10 via the lead line 3a. In the input unit 10, since the first electrode 11 and the second electrode 12 oppose each other with a narrow distance therebetween, a secondary induction power E2 with the same waveform is led to the second electrode 12 by the induction power E1 that is led to the first electrode 11. The secondary induction power E2 that is inducted to the second electrode 12 is amplified by the voltage amplification unit 21 of the detection circuit 20, and the peak value thereof is held by the peak holding unit 22. The holding value is updated when the peak value changes by a fixed range or greater.
A detection output D1 with which the peak value is held by the peak holding unit 22 is illustrated in
The detection output D1, that is, an output with which the peak value of the secondary induction power E2 is held is inversely proportional to the square of the opposing distance d between the first electrode 11 and the second electrode 12, and is proportional to the opposing area A of the first electrode 11 and the second electrode 12.
The opposing distance d is, for example, 5 to 100 μm, and the opposing area A is approximately 1 to 100 mm2.
In the input detection device 1, when the first driving signal S1 with a fixed frequency is being applied to the driving circuit 5, by changing at least one of the opposing distance d and the opposing area A between the first electrode 11 and the second electrode 12 of the input unit 10 by operating an operation member (not shown), a detection output D1 that can change to reflect the operation state of the operation member at the input unit 10 can be obtained.
An input detection device 1A of a modified example illustrated in
In the input unit 10A, the resistance value of the resistance layer R is changed by the sheet 18 being bent or stretched by an operation member (not shown), and as a result, a variable induction power E3 in which the induction power E1 that is inducted to the induction member 3 is varied can be obtained. By amplifying and peak-holding the variable induction power E3, a detection output that reflects changes in the input unit 10A can be obtained.
The input detection device 100 has the coil 2 for generating a counter-electromotive force configured as a portion of a vibration generation unit 30.
The vibration generation unit 30 includes an external casing 3A that contains the coil 2 and other constituent members. The exterior casing 3A is formed of a conductive metallic material, and exhibits the same functions as the induction member 3 illustrated in
The vibration generation unit 30 has a vibrator 31 with a fixed mass on the inside of the exterior casing 3A. The vibrator 31 is formed by a soft magnetic material such as ferrite to be long and thin, and the coil 2 is wound around the outer circumference of the vibrator 31. The vibrator 31 is supported by an elastic support member 32 inside the exterior casing 3A so that the vibrator 31 is able to vibrate in the up and down direction in the drawing. The elastic support member 32 is formed of a leaf spring, a compression coil spring, or the like. The vibrator 31 has a natural frequency that is determined by the mass thereof, the mass of the coil, and the elastic coefficient of the elastic support member 32.
A pair of magnets 33 and 34 is provided on the inside of the exterior casing 3A. The magnet 33 opposes a left side end portion 31a of the vibrator 31, and the magnet 34 opposes a right side end portion 31b of the vibrator 31. The left side magnet 33 has an upper side opposing face 33a that is magnetized to the N pole and a lower side opposing face 33b that is magnetized to the S pole. The right side magnet 34 has an upper side opposing face 34a that is magnetized to the S pole and a lower side opposing face 34b that is magnetized to the N pole. That is, the left and right magnets 33 and 34 both have upper and lower portions that are magnetized to different magnetic poles, and between the magnet 33 and the magnet 34, different magnetic poles to each other are opposing.
When electricity is not passed through the coil 2 and an external force is not acting on the vibrator 31, the left side end portion 31a of the vibrator 31 opposes a boundary portion between the upper side opposing face 33a and the lower side opposing face 33b of the magnet 33, and the right side end portion 31b of the vibrator 31 opposes a boundary portion between the upper side opposing face 34a and the lower side opposing face 34b of the magnet 34.
As illustrated in
In the input detection device 100 illustrated in
The lead line 3a that is connected to the exterior casing 3A that is an induction member is connected to the first electrode 11 that configures the input unit 10. The second electrode 12 that opposes the first electrode 11 is connected to the voltage amplification unit 21 of the detection circuit 20. As illustrated in
The vibration control unit 25 is configured by the CPU of a microcomputer or the like, and includes a level detection unit 26 and a waveform output unit 27 as the main control operations thereof. The waveform of the first driving signal S1 for applying the detection current Ia to the coil 2 and the waveform of the second driving signal S2 for applying the vibration current Ib to the coil 2 are output from the waveform output unit 27. The first driving signal S1 and the second driving signal S2 are provided to an OR circuit 28, and a logical sum output from the OR circuit 28 is provided to the base terminal of the transistor 8 of the driving circuit 5.
The vibration generation unit 30 is arranged on the inner face of the casing of various electronic apparatuses such as mobile communication apparatuses and remote controllers, and the vibrations that are generated by the vibration generation unit 30 can be felt by the hand or the fingers that are holding the casing. The input unit 10 can be operated by an operation member that is provided on the casing. Here, when the input unit 10 is provided on the surface of the exterior casing 3A of the vibration generation unit 30 and the input unit 10 is operated via the operation member, the vibrations that are generated at the vibration generation unit 30 may be passed directly onto the fingers that are operating the operation member.
Next, the operation of the input detection device 100 will be described with reference to the waveform view illustrated in
When the input unit 10 is not operated by the operation member and the opposing distance d and the opposing area A between the first electrode 11 and the second electrode 12 are in the initial state, only the first driving signal S1 illustrated in
In the input detection device 100, when the first driving signal S1 passes through the OR circuit 28 and is provided to the base terminal of the transistor 8, the detection current Ia illustrated in
In order to provide the detection current Ia to the coil 2 without vibrating the vibrator 31, it is necessary for the frequency of the detection current Ia to be equal to or greater than 10 times the natural frequency of the vibrator 31, and is preferably equal to or greater than 50 times.
When the detection current Ia flows through the coil 2 without the vibrator 31 vibrating, the induction power E1 due to the counter-electromotive force illustrated in
When it is determined by the level detection unit 26 that the input unit 10 has been operated by the operation member, at least one of the opposing distance d and the opposing area A between the first electrode 11 and the second electrode 12 has changed, the output D1 illustrated in
The first driving signal S1 and the second driving signal S2 are provided to the OR circuit 28, and a signal L of the logical sum illustrated in
In the input unit 10, as the opposing distance d between the first electrode 11 and the second electrode 12 narrows, the detection output D1 illustrated in
Further, in the input unit 10, as the deviation amount of the mutual positions of the first electrode 11 and the second electrode 12 increases and the opposing area A between the electrodes decreases, the detection output D1 decreases. When it is determined by the level detection unit 26 illustrated in
The second electrode 12 is provided fixed on a non-conductive base film 13. The second electrode 12 is a low resistance material layer of a copper foil layer or a silver paste layer. A drawn-out layer 12e that extends from the second electrode 12 is connected to the voltage amplification unit 21 of the detection circuit 20. A non-conductive distance film 14 is adhered to the surface of the second electrode 12.
The first electrode 11 is provided fixed to the lower face of a non-conductive upper portion film 15. The first electrode 11 is formed of the same low-resistance material as the second electrode 12. A drawn-out layer 11a that extends from the first electrode is connected to the lead line 3a illustrated in
As illustrated in
In the input unit 10 illustrated in
A cross-shaped base film 113 and an upper portion film 115 are provided on the input device 110, and input units 10a, 10b, 10c, and 10d are arranged at four locations between the base film 113 and the upper portion film 115. The structures of the respective input units 10a, 10b, 10c, and 10d are the same as those illustrated in
An operation member 111 is arranged on the upper portion film 115. The fulcrum of the operation member 111 is on the lower face of a central portion 111a, and the operation member 111 can be tilted in any direction on the X-Y plane.
The lead line 3a that extends from the induction member 3 or the exterior casing 3A is connected to the respective first electrode 11 of the input units 10a, 10b, 10c, and 10d. The second electrode 12 of the input unit 10a is connected to a detection circuit 20a that includes a voltage amplifier 21a and a peak holding unit 22a. Similarly, the second electrode 12 of the input units 10b, 10c, and 10d is respectively connected to a voltage amplification unit 21b, 21c, and 21d of detection circuits 20b, 20c, and 20d.
In the input device 110 illustrated in
Further, similarly to the input device 110 illustrated in
An input device 120 illustrated in
The first electrode 11 is connected to the lead line 3a that extends from the induction member 3 or the exterior casing 3A. The second electrode 12a is connected to the voltage amplification unit 21a of the detection circuit 20a illustrated in
The input device 120 has a non-conductive distance film 114 laid over the first electrode 11 and the second electrodes 12a, 12b, 12c, and 12d, and a movable electrode 118 is provided thereon. The movable electrode 118 is formed of the same low-resistance material as the first electrode 11 and the second electrodes 12a, 12b, 12c, and 12d. The movable electrode 118 is provided on the bottom face of an operation member that is disk-shaped or the like. By operating the operation member, the movable electrode 118 can be slid in the respective X-Y directions in a state of maintaining an opposing distance da between the first electrode 11 and the second electrodes 12a, 12b, 12c, and 12d.
In the input device 120 illustrated in
As illustrated in
As illustrated in
As described above, in the input device 120, a detection output corresponding to the sliding direction of the movable electrode 118 and fluctuations in the sliding distance can be obtained.
In the input device 110 illustrated in
Similarly, in the input device 120 illustrated in
It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and alterations may occur depending on design requirements and other factors insofar as they are within the scope of the appended claims of the equivalents thereof.
Number | Date | Country | Kind |
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2011-204165 | Sep 2011 | JP | national |