JP2019211841A - Operation input device - Google Patents

Abstract

To provide an operation input device excellent in responsiveness of vibration feedback.SOLUTION: An operation input device 1 is configured to comprise: an operation panel 10 as an operation unit operated by pressing; a piezoelectric device 20 receiving a load through pressing operation to the operation panel 10 to generate a generation voltage by the load, and displaced when a drive voltage is applied; a booster circuit 30 supplying a boosted drive voltage to the piezoelectric device 20; and a control unit 40 including a pressing detection unit 42 for detecting a pressing state on the basis of the generation voltage generated in the piezoelectric device 20 and a boost control unit 46 for controlling a boost operation at the booster circuit 30 on the basis of the detection result from the pressing detection unit 42. Thus, there is provided an operation input device with less boost waiting time at a booster circuit and excellent responsiveness of vibration feedback.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an operation input device.

  Conventionally, there has been disclosed an operation input device that turns on a switch by applying a load to a piezoelectric element and delays the electric power generated when the load is applied to the piezoelectric element to give a tactile sense by applying it to the piezoelectric element. (For example, refer to Patent Document 1).

  The operation input device includes a piezoelectric key switch that provides a tactile response, a piezoelectric element that is fixed at an edge, and a keypad that is attached to the piezoelectric element at a distance from the fixed edge. As a result, the element bends, and a voltage signal is generated between the grounded metal disk and the electrode. The voltage signal from the electrode is sent to the wire. In response to the voltage signal, the drive circuit provides a drive signal to deflect the piezoelectric element and present an upward haptic feedback on the keypad.

JP-A-10-307661

  In the prior art, when the keypad is pressed, a driving signal is provided to the piezoelectric element to present upward haptic feedback to the keypad. The drive signal for driving the piezoelectric element is generally a high voltage, and it is necessary to drive the piezoelectric element after boosting the voltage by a booster circuit in response to the voltage signal. However, when boosting is performed by the booster circuit, there is a problem that a boost waiting time occurs, and the response from touch to vibration feedback is deteriorated.

  Accordingly, an object of the present invention is to provide an operation input device having excellent vibration feedback response.

[1] In order to achieve the above object, an operation unit that is operated to be pressed, and a piezoelectric element that receives a load when the operation unit is pressed and generates a generated voltage by the load and is displaced when a drive voltage is applied. An element, a booster circuit that supplies the boosted drive voltage to the piezoelectric element, a press detection unit that detects a press state based on the generated voltage generated by the piezoelectric element, and a detection result of the press detection unit And a control unit including a boosting control unit that controls the boosting operation of the boosting circuit.
[2] The boosting control unit starts the boosting operation of the boosting circuit when the generated voltage exceeds a boosting start threshold smaller than a pressing determination threshold for determining that the generated voltage is pressed by the pressing operation. The operation input device according to the above [1] that performs control may be used.
[3] The operation input device according to [2], wherein the boosting circuit stops the boosting operation until receiving a command to start the boosting operation from the control unit.

  According to the operation input device of the present invention, it is possible to provide an operation input device having excellent vibration feedback responsiveness.

FIG. 1 is a block configuration diagram showing a schematic configuration of an operation input device according to an embodiment of the present invention. FIG. 2 is a flowchart showing the operation of the operation input device according to the embodiment of the present invention.

(Operation input device according to an embodiment of the present invention)
As shown in FIG. 1, an operation input device 1 according to an embodiment of the present invention receives an operation panel 10 as an operation unit to be pressed and receives a load by pressing the operation panel 10, and generates a voltage by the load. The piezoelectric element 20 that is displaced when a drive voltage is applied, a booster circuit 30 that supplies a boosted drive voltage to the piezoelectric element 20, and a pressed state based on the generated voltage generated by the piezoelectric element 20 And a control unit 40 including a press detection unit 42 to detect and a boost control unit 46 to control the boost operation of the boost circuit 30 based on the detection result of the press detection unit 42.

  As shown in FIG. 1, the control unit 40 outputs a drive signal Vs for vibration feedback of the piezoelectric element 20 to the booster circuit 30. The drive signal Vs is boosted by the booster circuit 30 and becomes the drive voltage Vd of the piezoelectric element 20.

(Operation panel 10)
The operation panel 10 as the operation unit is formed of, for example, a resin such as acrylic. As shown in FIG. 1, the operation panel 10 has an edge 20 a supported by a base 70. As shown in FIG. 1, the operation panel 10 can be bent by being pressed with a pressing force F. Further, as will be described later, the piezoelectric element 20 can be bent upward or downward by being deformed upward or downward.

(Piezoelectric element 20)
The piezoelectric element 20 is, for example, a unimorph type in which electrodes (not shown) are attached to both surfaces of the piezoelectric element material 21 and are bonded and fixed to a metal shim 22 larger than the diameter of the piezoelectric element material 21. By applying a driving voltage to the electrodes, the piezoelectric element material expands and contracts, so that the metal shim 22 is warped and the piezoelectric element material 21 and the entire metal shim 22 are bent. In the present embodiment, the unit in which the metal shim 22 and the piezoelectric element material 21 are bonded and fixed and the electrodes are attached is referred to as the piezoelectric element 20.

  As shown in FIG. 1, the piezoelectric element 20 has an edge 20 a supported by a base 70. The piezoelectric element 20 has, for example, a circular shape in plan view. A recess 70a is formed in the base 70, and the piezoelectric element 20 is supported so as to be deformable in the direction of the recess 70a. Further, the upper side of the piezoelectric element 20 is attached so as to be connected to the operation panel 10 via the pusher 24. Accordingly, as shown in FIG. 1, when the operation panel 10 is bent by being pressed with the pressing force F, the piezoelectric element 20 is also deformed accordingly. Further, when the piezoelectric element 20 is deformed upward or downward, the operation panel 10 can also be deformed upward or downward.

  The piezoelectric element 20 has, for example, a plate-shaped piezoelectric element material and is disposed on the upper surface of a metal shim. Examples of the piezoelectric element material include lithium niobate, barium titanate, lead titanate, lead zirconate titanate (PZT), lead metaniobate, and polyvinylidene fluoride (PVDF). The piezoelectric element 20 is formed of, for example, a film formed using these materials.

  As shown in FIG. 1, when the piezoelectric element 20 is bent by being pressed with a pressing force F by the finger 100, the piezoelectric element 20 outputs a generated voltage Vx corresponding to this deformation. Further, when a voltage is applied, the piezoelectric element 20 expands and contracts according to the drive voltage Vd. For example, as shown in FIG. 1, the piezoelectric element 20 outputs a voltage based on a load output according to the pressing force F to the control unit 40 as a generated voltage Vx.

  In addition, the piezoelectric element 20 is configured to expand and contract in accordance with the drive voltage Vd output from the control unit 40 and to be deformed and bent together with the metal shim 22. This deformation or deflection displaces or vibrates the operation panel 10. Thereby, vibration feedback can be performed to the operator via the operation panel 10.

  That is, the piezoelectric element 20 of the operation input device 1 according to the present embodiment serves both as load detection and vibration feedback.

  As shown in FIG. 1, the lower surface of the piezoelectric element material 21 is connected to the control unit 40, and the upper surface is connected to the output terminal 50 a of the switch unit 50.

  As shown in FIG. 1, the first switching terminal 50b of the switch unit 50 is connected to the control unit 40, and the press detection unit 42 can detect whether or not the switch is pressed based on the generated voltage Vx.

  The second switching terminal 50 c of the switch unit 50 is connected to the booster circuit 30. In addition, the control terminal 50d of the switch unit 50 is connected to the control unit 40, and the switching control unit 44 can perform switching control of whether to perform pressing detection or vibration feedback.

  The output terminal 30 a of the booster circuit 30 is connected to the second switching terminal 50 c of the switch unit 50. Further, the input terminal 30 b of the booster circuit 30 is connected to the control unit 40, and the boosting operation in the booster circuit 30 is performed based on the drive signal Vs from the boosting control unit 46.

(Boost circuit 30)
A circuit such as a DC-DC converter or a charge pump can be used as the booster circuit. The DC-DC converter can use a switching regulator capable of boosting. The switching regulator circuit is a system in which an internal switching element is repeatedly turned on and off to obtain a constant output. By repeating this operation at high speed, the output voltage can be boosted to a specified value and adjusted.

  The charge pump is a booster circuit for increasing the voltage by combining a capacitor and a switch. Specifically, this is a method of obtaining a boosted voltage by causing the charge to transition and superimposing the input voltage and the voltage charged in the capacitor.

  These booster circuits require repeated switching on and off of the switching elements and a charge transition process, so that it takes time to boost the voltage to a predetermined voltage. That is, a boosting waiting time occurs. If the booster circuit is always operated in order to avoid the occurrence of the boost waiting time, there is a problem that power consumption increases. There is also a problem that radiation noise is at a high level. In the present embodiment, the booster circuit 30 stops the boosting operation until receiving a command for starting the boosting operation from the control unit 40.

(Control unit 40)
As shown in FIG. 1, the control unit 40 includes a press detection unit 42, a switching control unit 44, a boost control unit 46, and the like. The press detection unit 42 detects a press operation on the operation panel 10. The switching control unit 44 outputs a switching control signal Ve to the control terminal 50d, and switches and controls the output terminal 50a of the switch unit 50 to the first switching terminal 50b or the second switching terminal 50c. By this switching control, it is possible to switch between pressing detection and vibration feedback. Further, the boost control unit 46 outputs the drive signal Vs to the input terminal 30b of the booster circuit 30, and controls the boosting operation in the booster circuit 30 based on this.

  The control unit 40 is a CPU (Central Processing Unit) that performs operations, processes, and the like on the acquired data in accordance with stored programs in order to control the press detection unit 42, the switching control unit 44, the boost control unit 46, and the like. The microcomputer includes a RAM (Random Access Memory) as a semiconductor memory and a ROM (Read Only Memory) as the storage unit 48.

  In the storage unit 48, in addition to the above programs, two types of threshold values used in the operation of the press detection unit 42 are stored. The first threshold is a pressing determination threshold Vonth that determines that the operation panel 10 has been pressed. The second threshold value is set to a value smaller than the pressing determination threshold value Vonth, and is a boosting start threshold value Vth for determining whether to start the boosting operation in the booster circuit 30.

(Operation of operation input device 1)
The operation will be described based on the flowchart showing the operation of the operation input device 1 according to the embodiment of the present invention shown in FIG. The control unit 40 executes the following calculation and processing according to the flowchart.

(Step 1)
The control unit 40 controls the switching control unit 44 to switch the output terminal 50a of the switch unit 50 to the first switching terminal 50b by outputting the switching control signal Ve. As a result, the generated voltage Vx can be input to the press detection unit 42. The controller 40 determines whether or not the generated voltage Vx exceeds the boost start threshold Vth. As described above, the boost start threshold Vth is set to a value smaller than the press determination threshold Vonth. When the generated voltage Vx exceeds the boost start threshold Vth, the process proceeds to Step 2 (Step 1: Yes). When the generated voltage Vx does not exceed the boost start threshold Vth, the process proceeds to Step 3 (Step 1: No).

(Step 2)
The control unit 40 turns on the boosting operation of the booster circuit 30. That is, the control unit 40 outputs the drive signal Vs from the boost control unit 46, starts the boost operation in the boost circuit 30, and proceeds to Step 4.

(Step 3)
The control unit 40 turns off the boosting operation of the boosting circuit 30, returns to Step 1, and repeatedly executes the determination operation.

(Step 4)
The control unit 40 determines whether or not the generated voltage Vx exceeds the pressing determination threshold value Vonth. When the generated voltage Vx exceeds the pressing determination threshold value Vonth, it is determined that the operation panel 10 has been pressed (switch operation), a switch-on signal is generated, and the process proceeds to Step 5 (Step 4: Yes). When the generated voltage Vx does not exceed the pressing determination threshold value Vonth, the process returns to Step 1 and the determination operation is repeated.

  When the control unit 40 determines that the operation panel 10 has been pressed (switch operation) and generates a switch-on signal, various operations of the device are executed by the switch-on signal. The switch-on signal is output via an in-vehicle LAN such as LIN or CAN of the vehicle, and can be used for controlling various in-vehicle device operations of the vehicle.

(Step 5)
The control unit 40 causes the switching control unit 44 to output a switching control signal Ve, and controls the output terminal 50a of the switch unit 50 to be switched to the second switching terminal 50c. Since the booster circuit 30 has already been turned on in Step 2, the booster circuit 30 can output a predetermined voltage without a boost wait time. Accordingly, the control unit 40 controls the switch unit 50 to apply the drive voltage Vd boosted to a predetermined voltage to the piezoelectric element 20 to vibrate the piezoelectric element 20. The vibration of the piezoelectric element 20 is transmitted to the operation panel 10 via the pusher 24, and vibration feedback can be performed to the operator.

  The above operation can be repeatedly executed until a stop command is output.

(Effect of embodiment)
The embodiment of the present invention has the following effects.
(1) The operation input device 1 according to the embodiment of the present invention receives an operation panel 10 as an operation unit to be pressed and receives a load by pressing the operation panel 10, and generates a generated voltage by the load. , A piezoelectric element 20 that is displaced when a drive voltage is applied, a booster circuit 30 that supplies a boosted drive voltage to the piezoelectric element 20, and a press detection that detects a press state based on a voltage generated in the piezoelectric element 20. And a control unit 40 including a boosting control unit 46 that controls the boosting operation of the boosting circuit 30 based on the detection result of the pressing detection unit 42. The press detection unit 42 determines the pressed state based on the boost start threshold Vth set to a value smaller than the press determination threshold Vonth, and starts the boost operation in the boost circuit 30 based on this. As a result, it is possible to perform vibration feedback without boosting standby time.
(2) The control unit 40 controls the boosting control unit 46 to start the boosting operation of the boosting circuit when the generated voltage exceeds the boosting start threshold value. Compared to the above, an operation input device with low current consumption, low radiation noise, and low fear of migration becomes possible.

  As mentioned above, although some embodiment of this invention was described, these embodiment is only an example and does not limit the invention which concerns on a claim. Moreover, these novel embodiments can be implemented in various other forms, and various omissions, replacements, changes, and the like can be made without departing from the scope of the present invention. In addition, not all the combinations of features described in these embodiments are essential to the means for solving the problems of the invention. Furthermore, these embodiments are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

DESCRIPTION OF SYMBOLS 1 ... Operation input apparatus, 10 ... Operation panel, 10a ... Edge part 20 ... Piezoelectric element, 20a ... Edge part, 21 ... Piezoelectric element material, 22 ... Metal shim, 24 ... Pusher 30 ... Booster circuit, 30a ... Output end, 30b ... Input end 40 ... Control unit, 42 ... Press-down detection unit, 44 ... Switch control unit, 46 ... Boost control unit, 48 ... Storage unit 50 ... Switch unit, 50a ... Output terminal, 50b ... Switch terminal, 50c ... Switch terminal, 50d ... Control terminal 70 ... Base, 70a ... Recess 100 ... Finger F ... Pressing force, Vd ... Drive voltage, Ve ... Switch control signal, Vonth ... Pressing determination threshold, Vs ... Drive signal, Vth ... Boost start threshold, Vx ... Generation Voltage

Claims (3)

An operation unit to be pressed;
A piezoelectric element that receives a load by a pressing operation to the operation unit, generates a generated voltage by the load, and is displaced when a drive voltage is applied;
A booster circuit for supplying the boosted drive voltage to the piezoelectric element;
A control unit comprising: a press detection unit that detects a press state based on the generated voltage generated by the piezoelectric element; and a boost control unit that controls a boost operation of the boost circuit based on a detection result of the press detection unit; And an operation input device.   The step-up control unit performs control to start the step-up operation of the step-up circuit when the generated voltage exceeds a step-up start threshold value that is smaller than a press-down determination threshold value that determines that the press-down operation has been performed. The operation input device according to claim 1.   The operation input device according to claim 2, wherein the booster circuit stops the boosting operation until receiving a command to start the boosting operation from the control unit.

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