Electronic devices and tactile feedback devices

Abstract

To provide an electronic apparatus with good responsibility and a tactile perception generation device.SOLUTION: An electronic apparatus includes: a load; a first switching element provided on a current path connected with the load; a drive circuit that drives the first switching element with a drive control signal based on a result of comparing a load signal obtained by converting a current flowing in the current path into a voltage with a reference signal that is a reference for an operation of the first switching element; and a second switching element that can switch a signal level of the drive control signal to a first level at which the first switching element is turned off and a second level at which the first switching element is turned on.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present disclosure relates to an electronic device and a tactile generator device.

Background Art

[0002] Conventionally, there is an output transistor that has first to third electrodes and controls an output voltage by flowing an output current between the first and second electrodes according to a first differential voltage that is a difference between a first voltage of the first electrode and a second voltage of the third electrode, an operational amplifier that controls the second voltage so that the output voltage becomes a target level, a startup circuit that maintains the second voltage at a third voltage so that the output transistor is turned off before startup of a voltage regulator circuit and enables the second voltage to be controllable by the operational amplifier after startup of the voltage regulator circuit, and a current output circuit that outputs an adjustment current from or to the third electrode so that the first differential voltage increases when the output voltage is less than a predetermined level. (For example, see Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in a conventional voltage regulator circuit, a startup circuit and a current output circuit are connected in series between a third voltage (Vdd) and an output terminal (Vout), and are controlled so as not to be turned on and off simultaneously, thereby preventing a through current from flowing. Therefore, it takes time until the on state or off state of the startup circuit and the current output circuit is determined, and it is difficult to obtain sufficient responsiveness.

[0005] Therefore, the objective is to provide electronic devices with good responsiveness and tactile feedback devices. [Means for solving the problem]

[0006] The electronic device of the embodiment of the present disclosure includes a load, a first switching element provided in a current path connected to the load, a drive circuit that drives the first switching element with a drive control signal based on a comparison result between a load signal obtained by converting the current flowing through the current path into a voltage and a reference signal that serves as a reference for the operation of the first switching element, and a second switching element that can switch the signal level of the drive control signal between a first level in which the first switching element is turned off and a second level in which the first switching element is turned on.

[0007] The tactile sensor according to the embodiment of the present disclosure includes an actuator that generates vibrations, a first switching element provided in a current path connected to the actuator, a drive circuit that drives the first switching element with a drive control signal based on a comparison result between a load signal obtained by converting the current flowing through the current path into a voltage and a reference signal that serves as a reference for the operation of the first switching element, and a second switching element that can switch the signal level of the drive control signal between a first level in which the first switching element is turned off and a second level in which the first switching element is turned on, wherein when the second switching element is switched off from a state in which the signal level of the drive control signal is at the first level, the drive circuit supplies an inrush current of the drive control signal to the control terminal of the first switching element. [Effects of the Invention]

[0008] This technology can provide highly responsive electronic devices and tactile feedback devices. [Brief explanation of the drawing]

[0009] [Figure 1] This is a plan view showing the input device 100 of the embodiment. [Figure 2] This is a cross-sectional view AA in Figure 1. [Figure 3] This is a block diagram showing the configuration of the input device 100. [Figure 4] This is a diagram showing the tactile sensation generating device 100A. [Figure 5] This diagram illustrates the operation of the tactile sensation generator 100A. [Figure 6] This diagram shows the configuration of the comparative drive control circuit 10A. [Figure 7] This diagram shows the operation of the comparative drive control circuit 10A. [Modes for carrying out the invention]

[0010] The following describes embodiments to which the electronic device and haptic generating device of this disclosure are applied. In the following, the XYZ coordinate system is defined and described. Also, for the sake of explanation, the -Z direction side will be referred to as the lower side or down, and the +Z direction side as the upper side or up, but this does not represent a universal up-down relationship. Also, viewing from the XY plane will be referred to as a planar view.

[0011] <Embodiment> <Configuration and operation of input device 100> Figure 1 is a plan view showing the input device 100 of the embodiment. Figure 2 is a cross-sectional view of AA in Figure 1. Figure 3 is a block diagram showing the configuration of the input device 100.

[0012] The input device 100 is a device that accepts operations performed by the user's fingertips or the like. The input device 100 may be included in, for example, a remote controller terminal or smartphone that remotely operates an operating target device that performs functions according to the operation content, or it may be integrally provided with the operating part of the operating target device. The input device 100 includes the electronic device and tactile feedback device of the embodiment.

[0013] The tactile sensation generating device of this embodiment is a device that generates a tactile sensation presented to the user's fingertips, etc., by vibrating an actuator 120 (an example of a load), which will be described later, when an operation is performed on the input device 100 by the user's fingertips, etc. The tactile sensation generating device of this embodiment is one specific example of the electronic device of this embodiment. The electronic device of this embodiment includes a load, and the tactile sensation generating device includes the actuator 120 as a load.

[0014] Here, a tactile feedback device including an actuator 120 is described as one specific example of the electronic device of the embodiment. However, the load included in the electronic device of the embodiment may be a load other than the actuator 120 (for example, an LED (light-emitting diode) or a heater). In other words, the load included in the electronic device of the embodiment may be an LED or a heater. Furthermore, here, a configuration in which the user operates the input device 100 with their fingertips is described, but it is also possible to operate it with parts of the user's body other than their fingertips.

[0015] The input device 100 includes a housing 101, a top panel 102, a touch sensor 110, an actuator 120, a load sensor 130, a circuit board 140, and a control unit 150. Of these, the touch sensor 110, the actuator 120, and the load sensor 130 are connected to the control unit 150 as shown in Figure 3. The touch sensor 110, the actuator 120, and the load sensor 130 are connected to the control unit 150 by the circuit board 140, but the circuit board 140 is omitted in Figure 3.

[0016] The housing 101 is made of resin, for example, and as shown in Figure 2, has an upper panel 101A, a lower panel 101B, and a projection 101C. The upper panel 101A and the lower panel 101B are plate-shaped and have a two-tiered structure. The upper panel 101A is deformable relative to the lower panel 101B when pressed downwards from the top side.

[0017] On the upper surface of the upper panel 101A, a touch sensor 110 and a top panel 102 are provided in this order, one above the other. On the lower surface of the upper panel 101A, an actuator 120 is attached, and a protrusion 101C protruding downward is formed.

[0018] On the upper surface of the lower panel 101B, a circuit board 140 is provided. A load sensor 130 is disposed at a portion below the protrusion 101C on the upper surface of the circuit board 140. Also, a control unit 150 is provided on the upper surface of the circuit board 140.

[0019] The upper surface of the top panel 102 is an operation surface 102A. On the operation surface 102A, as an example, three switches SW1, SW2, and SW3 are arranged as shown in FIG. 1. The switches SW1, SW2, and SW3 are, for example, those in which symbols representing the operation targets of the switches SW1, SW2, and SW3 are provided on the operation surface 102A of the top panel 102. The symbols of the switches SW1, SW2, and SW3 may be, for example, those displayed by printing or the like on the operation surface 102A. A symbol is, for example, a character, number, symbol, diagram, mark, etc. having a predetermined meaning, and here it represents the functions, types, etc. of the switches SW1, SW2, and SW3.

[0020] Also, the symbols of the switches SW1, SW2, and SW3 may be illuminating portions that emit light by providing a light-transmitting portion having the shape of the symbol on the light-shielding top panel 102 and irradiating it with an LED or the like from the lower surface side of the top panel 102. Further, the symbols of the switches SW1, SW2, and SW3 may be a GUI (graphical user interface) displayed on a display panel provided below the transparent top panel 102. As the display panel, for example, a liquid crystal panel, an OLED (organic light emitting diode) display panel, or the like can be used.

[0021] The touch sensor 110 is located below the top panel 102 and is a device that detects the position of a user's fingertip or the like when it comes into contact with (touches) the top panel 102. As an example, the touch sensor 110 can be a capacitive type sensor that detects changes in capacitance due to the approach of a user's fingertip or the like. As an example, the touch sensor 110 may have three electrodes corresponding to switches SW1, SW2, and SW3 and detect contact with each of the switches SW1, SW2, and SW3, or it may have multiple electrodes extending in the X and Y directions and detect operation on switches SW1, SW2, and SW3 by detecting the XY coordinates.

[0022] The actuator 120 is mounted on the underside of the upper panel 101A of the housing 101. When a fingertip operation is detected by the touch sensor 110, the actuator 120 is driven by the control unit 150 and generates vibration. The actuator 120 can be, for example, a piezoelectric element, an eccentric motor, a solenoid, or an LRA (linear resonant actuator).

[0023] The load sensor 130 is pressed by the projection 101C when any of the switches SW1, SW2, or SW3 on the top panel 102 are operated, causing the upper panel 101A to bend downward. The load sensor 130 outputs an output signal to the control unit 150 that represents the magnitude of the load caused by the press. Alternatively, a pressure sensor (strain sensor), an electrostatic sensor that detects changes in capacitance, or an optical sensor that detects the distance to the projection 101C may be used instead of the load sensor 130. Furthermore, multiple load sensors 130 and projections 101C may be provided at multiple positions with different XY coordinates.

[0024] The circuit board 140 is located on the upper surface of the lower panel 101B of the housing 101. As shown in Figure 3, the circuit board 140 includes wiring and circuit elements that connect the touch sensor 110, actuator 120, and load sensor 130 to the control unit 150. The drive control circuit that drives the actuator 120 with a control signal output by the control unit 150 will be described later with reference to Figure 4.

[0025] The control unit 150 is implemented, for example, by a microcontroller implemented by a computer that includes a CPU (Central Processing Unit), RAM (Random Access Memory), ROM (Read Only Memory), HDD (Hard Disk Drive), input / output interface, and internal bus.

[0026] When the control unit 150 detects an operation on any of the switches SW1, SW2, or SW3 by the touch sensor 110, and the load sensor 130 detects that a pressing operation has been performed, it drives the actuator 120. As a result, a tactile sensation is presented to the user's fingertip that is in contact with any of the switches SW1, SW2, or SW3.

[0027] For example, if a fingertip touches and presses one of switches SW1, SW2, or SW3, the operation on the switch being touched (any of SW1 to SW3) is confirmed. More specifically, when a fingertip touches the SW1, SW2, or SW3 portion of the top panel 102, the touch sensor 110 detects that contact has been made with one of the switches SW1, SW2, or SW3, and if a pressing operation is performed, the load sensor 130 detects that a pressing operation has been performed. As a result, the control unit 150 drives the actuator 120. The user can perceive that the operation has been confirmed by the tactile sensation presented to their fingertip by the driving of the actuator 120. The control unit 150 also notifies the target device of a signal indicating that an operation has been made on one of the switches SW1, SW2, or SW3. As a result, the target device executes a function corresponding to the operation on one of the switches SW1, SW2, or SW3.

[0028] <Configuration of the tactile sensation generator 100A> Figure 4 shows the tactile sensation generating device 100A. The tactile sensation generating device 100A includes an actuator 120 and a drive control circuit 140A. The tactile sensation generating device 100A may also include a control unit 150 (see Figures 2 and 3) in addition to the actuator 120 and the drive control circuit 140A, but here we will describe a configuration in which the tactile sensation generating device 100A includes the actuator 120 and the drive control circuit 140A.

[0029] The drive control circuit 140A is included in the circuit board 140 (see Figure 2) and includes wiring and circuit elements that drive the actuator 120 in accordance with the reference signal and base control signal output from the control unit 150.

[0030] <Configuration of drive control circuit 140A> The drive control circuit 140A, as shown in Figure 4, includes a field-effect transistor (FET) 141, an operational amplifier 142, a transistor 143, a signal transmission line 144, and resistors R1 to R6. Figure 4 also shows the power supply terminal 50. The voltage applied to the power supply terminal 50 is higher than the rated voltage required to operate the operational amplifier 142 and the control unit 150. The FET 141 is an example of a first switching element. The operational amplifier 142 is an example of a drive circuit. The transistor 143 is an example of a second switching element.

[0031] The actuator 120 is inserted in series with the wiring connected to the power supply terminal 50, which outputs DC power. The wiring connected to the power supply terminal 50 is connected to the drain terminal (D) of the FET 141.

[0032] FET141 has a drain terminal (D), a source terminal (S), and a gate terminal (G). The gate terminal is an example of a control terminal for FET141. Figure 4 shows the parasitic capacitance Cgs between the gate and source terminals of FET141. The drain terminal is connected to actuator 120. The source terminal is connected to the inverting input terminal of op-amp 142 via resistor R4 and is also grounded via resistor R5. The path from power supply terminal 50 through actuator 120, FET141, and resistor R5 to the ground potential point is a current path that supplies current to actuator 120. FET141 and op-amp 142 constitute a constant current circuit. The ground potential point is an example of a reference potential point.

[0033] The operational amplifier 142 has a non-inverting input terminal to which a reference signal is input from the control unit 150 (see Figures 2 and 3), an inverting input terminal connected to the source terminal of the FET 141 via resistor R4, and an output terminal connected to the gate terminal of the FET 141 via resistor R2. Resistor R2 is an example of a first resistor. The line connecting the output terminal of the operational amplifier 142 and the gate terminal of the FET 141 is a signal transmission line 144 that transmits the drive control signal, which will be described later.

[0034] Resistor R2 is provided to protect the operational amplifier 142 by limiting the inrush current flowing from the output terminal of the operational amplifier 142 to the signal transmission line 144. Resistor R1 is connected as a negative feedback resistor between the inverting input terminal and the output terminal of the operational amplifier 142.

[0035] Two branch lines are connected between the signal transmission line 144 and the ground potential point. A resistor R3 is inserted in series into one branch line, and a resistor R6 and a transistor 143 are connected to the other branch line. Resistor R6 is an example of a second resistor. One end of resistor R6 is connected to the signal transmission line 144, and the other end is connected to the collector terminal of transistor 143. The collector terminal of transistor 143 is an example of a current input terminal. The emitter terminal of transistor 143 is grounded, and a base control signal is input to the base terminal from the control unit 150.

[0036] Resistor R3 has the function of fixing the voltage applied to the gate terminal of FET 141 so that FET 141 does not turn on unintentionally due to noise, etc. Resistor R6 has the function of fixing the potential of the signal transmission path 144 (the potential of the gate terminal of FET 141) to the voltage at which FET 141 turns off when transistor 143 is on. Resistor R6 also has the function of protecting transistor 143 by limiting the current flowing between the collector and emitter of transistor 143 when the charge of the parasitic capacitance Cgs between the gate and source of FET 141 is discharged by transistor 143, which is turned on when FET 141 is turned off.

[0037] The inverting input terminal receives a load signal, which is obtained by converting the current flowing through the current path between actuator 120 and resistor R5 into a voltage using resistor R5. The reference signal input from control unit 150 (see Figures 2 and 3) to the non-inverting input terminal is the reference signal for the operation of FET 141. The operational amplifier 142 outputs a drive control signal to the gate terminal of FET 141 based on the comparison result between the load signal input to the inverting input terminal and the reference signal. The signal level of the drive control signal is the signal level at the gate terminal of FET 141, which is the signal level in the portion of the signal transmission path 144 closer to the gate terminal than resistor R2.

[0038] In such a drive control circuit 140A, transistor 143 is provided to control the voltage at the gate terminal of FET 141 and to improve the on / off responsiveness of FET 141. Improving the on / off responsiveness of FET 141 is done to improve the response performance of actuator 120 in the tactile sensation generator 100A, thereby presenting a crisp click sensation (tactile feedback) to the user's fingertips. Transistor 143 is controlled on / off by the base control signal, turning it off when FET 141 is turned on and on when FET 141 is turned off. The base control signal is a signal for controlling the voltage at the gate terminal of FET 141 through the on / off switching of transistor 143.

[0039] Furthermore, transistor 143 is turned on when FET 141 is turned off, connecting the signal transmission path 144 to the ground potential point via resistor R6 and transistor 143, and immediately turning off FET 141 by discharging the charge at the gate terminal of FET 141 to the ground potential point via the signal transmission path 144. Transistor 143, which operates in this manner, is used to improve the responsiveness when turning off FET 141. When the signal transmission path 144 is connected to the ground potential point via resistor R6 and transistor 143, the signal level of the drive control signal is reduced to a value corresponding to the current flowing through resistor R6, and becomes lower than the output voltage of op-amp 142. In other words, when FET 141 is turned off, transistor 143 is turned on, so a drive control signal with a voltage level lower than the output voltage of op-amp 142 is supplied to the gate terminal of FET 141.

[0040] Furthermore, even when the output voltage of op-amp 142 is at its maximum voltage (5V), the resistance value of resistor R6 is set to be smaller than the resistance value of resistor R2 in order to reliably turn off FET 141.

[0041] Furthermore, transistor 143 switches off when FET 141 is turned on, thereby inputting a drive control signal based on the output voltage of op-amp 142 to the gate terminal of FET 141. Immediately before FET 141 is turned on, transistor 143 is on and FET 141 is off, and the output voltage of op-amp 142 is at its maximum voltage (5V). Therefore, the moment transistor 143 is turned on, the maximum voltage of op-amp 142 is applied to the gate-source voltage Vgs of FET 141, generating a rush (inrush voltage) and instantly turning on FET 141. Transistor 143, which operates in this manner, is used to improve the responsiveness when turning on FET 141. When FET 141 is turned on, transistor 143 is turned off, so a drive control signal with a voltage level based on the output voltage of op-amp 142 is supplied to the gate of FET 141. The voltage level of the drive control signal at this time is output from op-amp 142 and becomes the voltage level after passing through resistor R2.

[0042] The reason why the output voltage of the operational amplifier 142 is maintained at its maximum voltage when transistor 143 is ON and FET 141 is OFF will be explained later.

[0043] <Operation of the tactile sensation generator 100A> Figure 5 is a diagram illustrating the operation of the tactile sensation generator 100A. In Figure 5, the horizontal axis represents time t. Figure 5 shows an example of the waveforms of the reference signal (vertical axis is voltage value), base control signal (vertical axis is voltage value), output voltage of the operational amplifier 142 (vertical axis is voltage value), gate-source voltage Vgs of the FET 141 (vertical axis is voltage value), and current of the actuator 120 (vertical axis is current value). The output voltage of the operational amplifier 142 is the voltage level at the output terminal of the operational amplifier 142, and is an example of the output level of the drive circuit. The signal level of the drive control signal is the signal level at the gate terminal of the FET 141, and therefore corresponds to the gate-source voltage Vgs of the FET 141.

[0044] In the initial state before time t1, the reference signal is not rising (low level), the base control signal is high level, and transistor 143 is on. Also, the output voltage of op-amp 142 is 5V (maximum value), but because transistor 143 is on, the gate-source voltage Vgs of FET 141 is Vgs1, and FET 141 is off. Therefore, no current flows through actuator 120. When transistor 143 turns on, the charge of the gate-source parasitic capacitance Cgs is discharged via the signal transmission line 144.

[0045] The output voltage of op-amp 142 is 5V, but because transistor 143 is on, the gate-source voltage Vgs of FET 141 is reduced to Vgs1. In other words, the signal level of the drive control signal is reduced to the first level, which turns off FET 141. Vgs1 is the voltage that turns off FET 141, and as an example, it is a voltage of about 1V or less. Furthermore, the output voltage of op-amp 142 becomes 5V (maximum value) when transistor 143 turns on, which reduces the voltage at the gate terminal of FET 141 and turns off FET 141. When this happens, the voltage at the source terminal of FET 141 becomes 0V, and 0V is negatively fed back to the inverting input terminal of op-amp 142 via resistor R4. Because an offset voltage exists between the non-inverting and inverting input terminals of the operational amplifier 142, when 0V is applied to the inverting input terminal, the output voltage increases. However, since transistor 143 is on and FET 141 is off, and the state of 0V being applied to the inverting input terminal continues, the maximum output voltage of 5V is output.

[0046] Note that the operation is the same even if the reference signal is raised to a high level in the initial state before time t1. In this case, the reference signal will be held at a high level regardless of whether FET141 is on or off.

[0047] At time t1, the reference signal rises to a high level, and the base control signal falls to a low level, turning transistor 143 off. The output voltage of op-amp 142 becomes V1, and because transistor 143 is off, the gate-source voltage Vgs of FET 141 increases. As a result, an inrush current instantaneously flows from the output terminal of op-amp 142 through the signal transmission line 144 to the gate terminal of FET 141.

[0048] As an inrush current flows from the output terminal of the operational amplifier 142 to the gate terminal of the FET 141, the gate-source parasitic capacitance Cgs of the FET 141 is immediately charged, and the FET 141 immediately turns on. At this time, the gate-source voltage Vgs rises to Vgs2, which is higher than Vgs1. The gate-source voltage Vgs2 is sufficient to turn on the FET 141. Because the gate-source voltage has increased to Vgs2, the signal level of the drive control signal has risen to the second level, which turns on the FET 141.

[0049] Furthermore, at time t1, a momentary rush occurs in the gate-source voltage Vgs of FET141, causing an inrush current to flow through actuator120. As a result, actuator120 is driven immediately at time t1.

[0050] Furthermore, at time t2, the reference signal falls to a low level, and the base control signal rises to a high level, turning on transistor 143. The output voltage of op-amp 142 becomes 5V, but because transistor 143 is on, the gate-source voltage Vgs of FET 141 immediately drops to Vgs1. As transistor 143 turns on, the charge of the gate-source parasitic capacitance Cgs is discharged through the signal transmission line 144, causing the gate-source voltage Vgs of FET 141 to immediately drop to Vgs1, turning off FET 141. At this time, the signal level of the drive control signal is lowered to the first level, which turns off FET 141.

[0051] When FET141 turns off at time t2, the current to actuator 120 becomes 0(A), and actuator 120 immediately stops at time t2.

[0052] In this way, a transistor 143 is provided in the branch line that branches off from the signal transmission line 144 to the ground potential point, and when turning off the FET 141, the charge of the gate-source parasitic capacitance Cgs is discharged from the signal transmission line 144 through the transistor 143, so that the FET 141 can be turned off immediately.

[0053] Furthermore, by turning off transistor 143 when FET 141 is turned on, a rush occurs in the gate-source voltage Vgs of FET 141. As a result, the gate-source parasitic capacitance Cgs of FET 141 is immediately charged, instantly increasing the gate-source voltage Vgs and allowing FET 141 to be turned on immediately.

[0054] <Configuration and operation of the comparative drive control circuit 10A> Figure 6 shows the configuration of a comparative drive control circuit 10A. The drive control circuit 10A includes an FET 141, an operational amplifier 142, a signal transmission line 144, and resistors R1 to R5. The comparative drive control circuit 10A has a configuration similar to the drive control circuit 140A shown in Figure 4, but without the transistor 143 and resistor R6. The actuator 120 is connected to the drain terminal of the FET 141 of the comparative drive control circuit 10A. This comparative drive control circuit 10A is a circuit shown for comparison purposes and is not prior art.

[0055] Figure 7 shows the operation of the comparative drive control circuit 10A. In Figure 7, the horizontal axis represents time t. Figure 7 shows an example of the waveforms of the reference signal (vertical axis is voltage value), the output voltage of the operational amplifier 142 (vertical axis is voltage value), the gate-source voltage Vgs of the FET 141 (vertical axis is voltage value), and the current of the actuator 120 (vertical axis is current value).

[0056] In the initial state before time t1, the reference signal is not rising (low level). The comparison drive control circuit 10A controls the on / off state of FET 141 by switching the reference signal between high and low levels, so when the reference signal is low, FET 141 is off.

[0057] Furthermore, when the reference signal is at an L level and FET 141 is off, the voltage value of the load signal input to the inverting input terminal via resistor R4 becomes a low voltage close to 0V, so the output voltage of op-amp 142 also becomes a low voltage close to 0V. This low voltage close to 0V of op-amp 142 is the difference from the 5V output shown in Figure 5.

[0058] At time t1, when the reference signal rises to a high level, the output voltage of the operational amplifier 142 rises to V1. However, when the reference signal is switched, the output voltage of the operational amplifier 142 is maintained at a low voltage close to 0V, so it is not possible to apply a rush that can instantaneously charge the parasitic capacitance Cgs between the gate and source of the FET 141. As a result, it takes time to charge the parasitic capacitance Cgs, and therefore it takes longer for the output voltage of the operational amplifier 142 to rise to V1 compared to the operation shown in Figure 5.

[0059] As a result, the gate-source voltage Vgs of FET141 becomes Vgs2 more gradually compared to the operation shown in Figure 5, and the actuator 120 is driven with a delay compared to the operation shown in Figure 5.

[0060] Furthermore, at time t2, when the reference signal falls to L level, the charge of the gate-source parasitic capacitance Cgs of FET141 is discharged by the op-amp 142 drawing it in through resistor R2. This results in a longer discharge time compared to discharging through resistor R6, which has a lower resistance than resistor R2, as shown in Figure 5. As a result, compared to Figure 5, the output voltage of op-amp 142 gradually decreases to a low voltage close to 0V, similar to the initial state, and the gate-source voltage Vgs of FET141 gradually decreases to a low voltage close to 0V, causing FET141 to turn off later than the operation shown in Figure 5. Consequently, the current of actuator 120 becomes a low current close to 0(A) later than the operation shown in Figure 5, and actuator 120 stops later than the operation shown in Figure 5.

[0061] Thus, in the comparative drive control circuit 10A, which does not include transistor 143 and resistor R6, the on / off response of FET 141 is worse than that of the drive control circuit 140A in the embodiment. This is because it is affected by the gate-source parasitic capacitance Cgs, etc.

[0062] As described above, a transistor 143 is provided in the branch line that branches off from the signal transmission line 144 to the ground potential point. When turning off the FET 141, the transistor 143 is turned on to set the drive control signal to the first level, and when turning on the FET 141, the transistor 143 is turned off to set the drive control signal to the second level, thereby enabling instant switching of the FET 141 on / off.

[0063] Therefore, it is possible to provide an electronic device with good responsiveness and a tactile feedback generator 100A. Furthermore, when the load connected to the drain terminal of FET 141 is an inductive load such as actuator 120, it is particularly effective because it affects the responsiveness of FET 141 compared to when the load is not inductive. As a result, in the tactile feedback generator 100A, the response performance of actuator 120 is improved, and a crisp click sensation (tactile feedback) can be presented to the user's fingertips.

[0064] Furthermore, transistor 143 is provided in a branch line that branches off from the signal transmission line 144 between the output terminal of the operational amplifier 142, which outputs a drive control signal to the FET 141, and the gate terminal of the FET 141, which is connected to the output terminal and receives the drive control signal, and is connected to the ground potential point. Transistor 143 is a switching element that switches the connection state between the signal transmission line 144 and the ground potential point. When transistor 143 is turned on, the signal level of the drive control signal becomes the first level, and when transistor 143 is turned off, the signal level of the drive control signal becomes the second level. Therefore, by turning on transistor 143, the signal level of the drive control signal can be reliably reduced to the first level, and the FET 141 can be turned off immediately and reliably.

[0065] Furthermore, since the circuit also includes a resistor R2 inserted between the branching point where the signal transmission line 144 branches off to the ground potential point and the output terminal of the operational amplifier 142, the inrush current flowing from the output terminal of the operational amplifier 142 to the signal transmission line 144 can be limited, thereby protecting the operational amplifier 142.

[0066] Furthermore, since it also includes a resistor R6 inserted between the branching point where the signal transmission line 144 branches off to the ground potential point and the current input terminal of transistor 143, when transistor 143 is turned on when FET 141 is turned off, it is possible to limit the current flowing between the collector and emitter of transistor 143 when discharging the charge of the parasitic capacitance Cgs between the gate and source of FET 141, thereby protecting transistor 143.

[0067] Furthermore, since the output level of the operational amplifier 142 is higher than the second level when the transistor 143 is ON, the inrush current of the drive control signal can be supplied to the gate terminal of the FET 141 more reliably.

[0068] Furthermore, when transistor 143 is switched off from the state where it is turned on and the signal level of the drive control signal is at the first level, the operational amplifier 142 supplies an inrush current of the drive control signal to the gate terminal of FET 141. This allows FET 141 to be turned on immediately, thereby more reliably improving the responsiveness of FET 141.

[0069] Although exemplary embodiments of the electronic devices and haptic generators of this disclosure have been described above, this disclosure is not limited to the specifically disclosed embodiments, and various modifications and changes are possible without departing from the scope of the claims. [Explanation of Symbols]

[0070] 100 Input Devices 100A Tactile Sensory Generator (Example of an electronic device) 101 cabinets 102 Top Panel 110 Touch Sensor 120 Actuators 130 Load Sensor 140 Circuit Boards 140A drive control circuit 141 FET (Example of a first switching element) 142 Operational Amplifier (Example of a Driving Circuit) 143 Transistors (an example of a second switching element) 144 Signal transmission path R1~R6 Resistors (R2 is an example of the first resistor, R6 is an example of the second resistor) 150 Control Unit

Claims

1. Load and A first switching element is provided in the current path connected to the load, A drive circuit that drives the first switching element with a drive control signal based on the comparison result between a load signal obtained by converting the current flowing through the current path into a voltage and a reference signal that serves as a reference for the operation of the first switching element, A second switching element capable of switching the signal level of the drive control signal between a first level in which the first switching element is turned off and a second level in which the first switching element is turned on. Includes, The second switching element is provided in a branch line that branches off from the signal transmission path between the output terminal of the drive circuit that outputs the drive control signal to the first switching element and the control terminal of the first switching element connected to the output terminal and to which the drive control signal is input, and is connected to a reference potential point, and is a switching element that switches the connection state between the signal transmission path and the reference potential point. When the second switching element is turned on, the signal level of the drive control signal becomes the first level. When the second switching element is turned off, the signal level of the drive control signal becomes the second level. An electronic device further comprising a first resistor inserted between a branching point that branches off from the signal transmission line to the reference potential point and the output terminal of the drive circuit.

2. Load and, A first switching element is provided in the current path connected to the load, A drive circuit that drives the first switching element with a drive control signal based on the comparison result between a load signal obtained by converting the current flowing through the current path into a voltage and a reference signal that serves as a reference for the operation of the first switching element, A second switching element capable of switching the signal level of the drive control signal between a first level in which the first switching element is turned off and a second level in which the first switching element is turned on. Includes, The second switching element is provided in a branch line that branches off from the signal transmission path between the output terminal of the drive circuit that outputs the drive control signal to the first switching element and the control terminal of the first switching element connected to the output terminal and to which the drive control signal is input, and is connected to a reference potential point, and is a switching element that switches the connection state between the signal transmission path and the reference potential point. When the second switching element is turned on, the signal level of the drive control signal becomes the first level. When the second switching element is turned off, the signal level of the drive control signal becomes the second level. An electronic device further comprising a second resistor inserted between a branching point that branches off from the signal transmission line to the reference potential point and the current input terminal of the second switching element.

3. Load and A first switching element is provided in the current path connected to the load, A drive circuit that drives the first switching element with a drive control signal based on the comparison result between a load signal obtained by converting the current flowing through the current path into a voltage and a reference signal that serves as a reference for the operation of the first switching element, A second switching element capable of switching the signal level of the drive control signal between a first level in which the first switching element is turned off and a second level in which the first switching element is turned on. Includes, An electronic device wherein the output level of the drive circuit is higher than the second level when the second switching element is turned on.

4. An actuator that generates vibrations, A first switching element provided in the current path connected to the actuator, A drive circuit that drives the first switching element with a drive control signal based on the comparison result between a load signal obtained by converting the current flowing through the current path into a voltage and a reference signal that serves as a reference for the operation of the first switching element, A second switching element capable of switching the signal level of the drive control signal between a first level in which the first switching element is turned off and a second level in which the first switching element is turned on. Includes, A tactile sensation generating device that, when the second switching element is turned on and the signal level of the drive control signal is at the first level, switches the second switching element off and the signal level of the drive control signal becomes the second level, supplies an inrush current of the drive control signal from the drive circuit to the control terminal of the first switching element.

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