JP6814065B2 - Tactile presentation device - Google Patents

Description

The present invention relates to a tactile presentation device.

As a conventional technique, an input unit, a plurality of vibrating parts provided in the input unit, and a control unit that vibrates a part of the vibrating parts among the plurality of vibrating parts according to the pressed input position are provided. A tactile transmission device is known (see, for example, Patent Document 1).

This tactile transmission device uses a piezoelectric element as a vibrating portion, and is configured to detect a load applied to an input portion by the piezoelectric element.

Japanese Unexamined Patent Publication No. 2011-90615

In some such tactile transmission devices, for example, a load is directly applied to the piezoelectric element by a pusher provided in the input unit, and when an unexpected excessive load is applied to the input unit. The piezoelectric element may be damaged.

Therefore, an object of the present invention is to provide a tactile presentation device capable of suppressing damage to the piezoelectric element when an unexpected load is applied.

One aspect of the present invention is associated with an operation unit having an operation surface, a piezoelectric element for detecting a load applied to the operation surface, an actuator having a metal shim integrated with the piezoelectric element, and an operation of pushing down the operation surface. Provided is a tactile presentation device including an operation unit in which the deformation of the metal shim is large and a pusher provided between the metal shims.

According to the present invention, damage to the piezoelectric element can be suppressed when an unexpected load is applied.

FIG. 1 (a) is a schematic view showing an example of a tactile presentation device according to an embodiment, and FIG. 1 (b) is cut along the lines I (b) -I (b) of FIG. 1 (a). This is an example of a cross-sectional view of the cross section viewed from the direction of the arrow. FIG. 2A is a schematic view showing an example of an actuator of the tactile presentation device according to the embodiment, FIG. 2B is a side view showing an example of the actuator, and FIG. 2C is a side view. It is an example of the block diagram of the tactile presentation device, and FIG. 2D is a schematic view showing an example of a database included in the tactile presentation device. FIG. 3 is a flowchart showing an example of the operation of the tactile presentation device according to the embodiment.

(Summary of Embodiment)
The tactile presentation device according to the embodiment pushes down an operation unit having an operation surface, a piezoelectric element for detecting a load applied to the operation surface, an actuator having a metal shim integrated with the piezoelectric element, and an operation surface. It is roughly configured with an operation portion in which the deformation of the metal shim becomes large due to the operation and a pusher provided between the metal shims.

In this tactile presentation device, since the operation unit and the piezoelectric element do not come into contact with each other, the piezoelectricity is generated when an unexpected load is applied as compared with the case where the pusher provided on the operation unit or the operation unit comes into contact with the piezoelectric element. Damage to the element can be suppressed.

[Embodiment]
(Outline of tactile presentation device 1)
FIG. 1 (a) is a schematic view showing an example of a tactile presentation device according to an embodiment, and FIG. 1 (b) is cut along the lines I (b) -I (b) of FIG. 1 (a). This is an example of a cross-sectional view of the cross section viewed from the direction of the arrow. FIG. 2A is a schematic view showing an example of an actuator of the tactile presentation device according to the embodiment, FIG. 2B is a side view showing an example of the actuator, and FIG. 2C is a side view. It is an example of the block diagram of the tactile presentation device, and FIG. 2D is a schematic view showing an example of a database included in the tactile presentation device. In each figure according to the embodiment described below, the ratio between the figures may differ from the actual ratio. Further, in FIG. 2C, the main signal and information flow are indicated by arrows.

The tactile presentation device 1 is arranged on the steering wheel of the vehicle, for example, and is configured to operate an electronic device mounted on the vehicle. Further, the tactile presentation device 1 is, for example, a small operating device operated by an operating finger such as a thumb while holding the steering wheel. The arrangement of the tactile presentation device 1 is not limited to this, and may be arranged near the display unit of the electronic device, for example, as an operation unit of the electronic device.

The tactile presentation device 1 includes, for example, as shown in FIGS. 1A to 2C, an operation unit 2 having an operation surface 200, a piezoelectric element 40 for detecting a load applied to the operation surface 200, and a piezoelectric element 40. An actuator 4 having a metal shim 41 integrated with a piezoelectric element 40, and a pusher 5 provided between an operation unit 2 and a metal shim 41 in which the metal shim 41 is greatly deformed due to an operation of pushing down the operation surface 200. , Is roughly configured. The actuator 4 is configured to detect a load and apply vibration to the operation surface 200.

As shown in FIG. 2A, for example, the piezoelectric element 40 has a shape symmetrical with respect to the pusher 5. The piezoelectric element 40 has a through hole 405. The pusher 5 is inserted into the through hole 405 and deforms the piezoelectric element 40 via the metal shim 41 in accordance with the operation of pushing down the operation surface 200 (push operation).

The tactile presentation device 1 further detects by applying a touch sensor 3 as a detection unit for detecting the position of the operating finger in contact with the operating surface 200 and a reference load for each of a plurality of regions defined on the operating surface 200. load force threshold determined for each region based on the load, and a drive signal S ₃ of each region for driving the actuator 4, based on the load threshold for operation finger is detected region and a control unit 8 for presenting tactile feedback, the drives the actuator 4 by a drive signal S ₃ corresponding to the region as well as determining the operating Te is schematically configured.

Therefore, the tactile presentation device 1 is configured to detect the load applied to the operation unit 2 and present tactile feedback due to vibration.

The operation surface 200 is, for example, the surface of the operation unit 2 shown in FIGS. 1 (a) and 1 (b). The operation surface 200 is defined as, for example, a central region (central region 27) and a plurality of regions (upper region 23 to right region 26) located across the central region. The region of the operation surface 200 is not limited to this, and can be arbitrarily set according to the specifications of the tactile presentation device 1.

Here, when the tactile presentation device 1 can instruct the movement of the cursor displayed on the display device, the operator moves the cursor upward by pressing the upper area 23, and lowers by pressing the lower area 24, for example. The direction can be moved to the left by pressing the left area 25, and to the right by pressing the right area 26. Then, for example, when the operator presses the central area 27 with the desired icon or the like selected by the cursor, the execution of the function of the selected icon is determined.

As an example, the tactile presentation device 1 presents tactile feedback that imitates a click feeling when a button is pressed when a push operation is determined for an area. The tactile feedback is not limited to this, and may be a tactile sensation indicating that the operation has been accepted.

(Structure of operation unit 2)
The operation unit 2 is roughly configured to include, for example, a touch sensor 3 and a base 20. The load applied to the operation unit 2 acts on the piezoelectric element 40 via the pusher 5 and the metal shim 41. Further, the vibration generated by the actuator 4 is transmitted to the operation unit 2 via the metal shim 41 and the pusher 5.

The touch sensor 3 is attached to the base 20. As shown in FIG. 1A, the base 20 is formed in a disk shape using resin, and arrows and characters in the up, down, left, and right directions are formed on the operation surface 200, which is the surface thereof, by printing, a laser, or the like. It is formed.

As a modification, the base 20 is formed of, for example, a transparent resin having a light-shielding region for blocking light and a transmission region for transmitting light formed on the surface, and a substrate having a light-emitting portion is arranged between the base 20 and the touch sensor 3. May be done. In this case, since the light from the light emitting unit is transmitted inside the base 20 and emitted from the transmission region, the transmission region is illuminated.

Further, as a modification, the operation unit 2 is not limited to a circular shape or a symmetrical shape in a top view, and may have another shape.

(Structure of touch sensor 3)
As shown in FIG. 1B, for example, the touch sensor 3 is roughly configured with a substrate 30 and an electrode portion 31. The touch sensor 3 has a disk shape according to the shape of the operation unit 2. The substrate 30 is, for example, a rigid substrate. The electrode portion 31 of the touch sensor 3 is attached to the front surface 30a side of the substrate 30, and the pusher 5 is attached to the back surface 30b side.

The touch sensor 3 is, for example, a capacitance type touch sensor. The touch sensor 3 is configured to output a detection signals S ₁ to determine whether the one of the region above the region 23 to the central region 27 defined at least on the operation surface 200 is operated finger in contact ing.

The electrode portion 31 of the touch sensor 3 has, for example, a detection electrode having a shape corresponding to the shape of the upper region 23 to the central region 27. The touch sensor 3 is configured to output a detection signal S ₁ , which is a capacitance signal detected for each region, to the control unit 8.

As a modification, the touch sensor 3 has a plurality of drive electrodes and a plurality of detection electrodes that are insulated and intersect with the drive electrodes, and the capacitance detected by all combinations of the drive electrodes and the detection electrodes can be obtained. it may be configured to output to the control unit 8 as a detection signal S _1. The control unit 8 is, for example, determines an area from coordinates the operation finger is detected in the coordinate system set on the operating face 200 on the basis of the detection signal S _1.

The upper region 23 is an region surrounded by a dotted line around the upward arrow on the paper surface of FIG. 1 (a). The lower region 24 is an region surrounded by a dotted line around a downward arrow. The left region 25 is an region surrounded by a dotted line around the arrow pointing to the left. The right region 26 is an region surrounded by a dotted line around the arrow pointing to the right. The central region 27 is an region surrounded by a dotted circle at the center of the operation unit 2. The circle surrounded by the dotted line having a wider interval than the other dotted lines indicates the outer shape of the actuator 4.

The pusher 5 described above is formed in a cylindrical shape by, for example, resin, and transmits the load of the operation unit 2 to the metal shim 41 of the actuator 4.

(Structure of actuator 4)
The actuator 4 is, for example, a unimorph type piezoelectric actuator including a piezoelectric element 40 and a metal shim 41, as shown in FIG. 1 (b).

The actuator 4 is attached to an attachment portion 14 formed on the support portion 10, for example, as shown in FIG. 1 (b). The mounting portion 14 has a shape into which the metal shim 41 of the actuator 4 is fitted. The mounting portion 14 is formed with a recess 12 that allows the load applied to the operation surface 200 and the deflection of the actuator 4 due to the vibration applied to the operation surface 200. The recess 12 is formed on the bottom surface of the mounting portion 14.

When a load is applied to the metal shim 41, the pusher 5 is attached at a position where the displacement is large. In other words, the pusher 5 is attached at a position where the amplitude is large when the actuator 4 is vibrating. The position where this displacement is large is the center when the metal shim 41 has a disk shape. The position where the displacement is large may be the center, the center of gravity, or the free end depending on the shape of the metal shim 41.

As shown in FIGS. 2A and 2B, for example, the piezoelectric element 40 has a disk shape, and has a schematic configuration in which the piezoelectric body 401 is sandwiched between the first electrode 400 and the second electrode 402. Has been done. As the material of the piezoelectric body 401, for example, lithium niobate, barium titanate, lead titanate, lead zirconate titanate (PZT), lead metaniobate, polyvinylidene fluoride (PVDF) and the like are used. The piezoelectric body 401 is, for example, a laminated type piezoelectric body formed by laminating a film formed by using these materials. The piezoelectric body is configured to be polarized in the thickness direction so that the piezoelectric constant is d33, and the output is increased with respect to deformation in the thickness direction.

The piezoelectric body 401 is easily broken by deformation due to an excessive load. Therefore, in the present embodiment, as shown in FIG. 1B, the pusher 5 to which the load of the operation unit 2 is transmitted is inserted into the through hole 405 so as not to come into direct contact with the piezoelectric element 40.

The first electrode 400 is electrically connected to the control unit 8 via a metal shim 41 and wiring. Further, the second electrode 402 is electrically connected to the control unit 8 via wiring.

As shown in FIG. 2A, for example, the metal shim 41 has a disk shape having a radius larger than that of the piezoelectric element 40. The metal shim 41 is made of, for example, conductive phosphor bronze or stainless steel.

When a load is applied to the operation surface 200 of the actuator 4, a load is applied to the piezoelectric element 40 via the operation unit 2, the pusher 5, and the metal shim 41, and the piezoelectric body 401 is deformed. The piezoelectric element 40 outputs a voltage corresponding to this deformation. Further, when a voltage is applied between the first electrode 400 and the second electrode 402, the piezoelectric body 401 is deformed according to the voltage. The actuator 4 outputs the voltage output according to the load to the control unit 8 as the load signal S ₂ , deforms according to the voltage based on the drive signal S ₃ output from the control unit 8, and vibrates together with the metal shim 41. It is configured as follows.

(Structure of control unit 8)
The control unit 8 includes, for example, a CPU (Central Processing Unit) that performs calculations and processing on the acquired data according to a stored program, a RAM (Random Access Memory) that is a semiconductor memory, a ROM (Read Only Memory), and the like. It is a microcomputer that is used. In this ROM, for example, a program for operating the control unit 8 and a database 80 are stored. The RAM is used, for example, as a storage area for temporarily storing a calculation result or the like. Further, the control unit 8 has a means for generating a clock signal inside thereof, and operates based on the clock signal.

The control unit 8 is configured to convert the load the load signals S ₂ output from the actuator 4.

The database 80 has, for example, as shown in FIG. 2D, a load threshold value and a drive waveform for each region, and a touch threshold value Th ₁₀ .

The load threshold value Th ₁ to the load threshold value Th ₅ are threshold values determined based on the load detected by the actuator 4 as a result of adding a reference load for each region. Specifically, the load threshold value Th ₁ of the upper region 23 is determined based on the load detected when the reference load is applied to the upper region 23. Similarly, the load thresholds Th ₂ to the load threshold Th ₅ of the lower region 24 to the central region 27 are determined based on the load detected when the reference load is applied to each of the lower region 24 to the central region 27. Be done.

Drive waveform Wa ₁ ~ driving waveform Wa ₅ is information relating to the drive signal _{S 3} of each region. The driving waveform Wa ₁ changes the like amplitude or frequency, based on the haptic feedback generated by the drive signal S ₃ with a reference waveform, in the operator defined so that it can be well recognized tactile feedback waveform is there. Similarly, the drive waveform Wa 2 _~ driving waveform Wa ₅ are respectively changed amplitude or frequency, etc., based on the haptic feedback generated by the drive signal S ₃ with a reference waveform, the operator well recognized tactile feedback It is a waveform defined so that it can be done.

Note the control unit 8 as a modified example, it may store the driving signal S ₃ of each area in the database 80. Further, the control unit 8 may store the drive waveform or drive signal for each region as a function in the database 80.

The touch threshold value Th ₁₀ is a threshold value for determining contact with the touch sensor 3. Control unit 8 determines a region where the touch threshold Th ₁₀ or more electrostatic capacitance is detected on the basis of the detection signals S ₁ to be input.

Control unit 8 determines by comparing the touch threshold value Th ₁₀ read from the capacitance and the database 80 for each area based on the detection signal S ₁ is operated finger touches area. Next, the control unit 8, when the region is determined and compared to the load based on the load signal S ₂ reads the load threshold value corresponding to the region from the database 80. The control unit 8, the load is greater than or equal to the load threshold, when the push operation on the region is determined, in order to generate haptic feedback, the drive signal S ₃ reads a driving waveform of the area from the database 80 It is generated to drive the actuator 4 and present tactile feedback.

The control unit 8 generates the operation information S4 including the information of the area where the push operation is performed based on the determination result, and outputs the operation information S ₄ to the connected electronic device.

The operation of the tactile presentation device 1 of the present embodiment will be described below with reference to the flowchart of FIG.

(motion)
Control unit 8 of the tactile display device 1, and the capacitance of each region based on the detection signals S ₁ acquired from the touch sensor 3, the touch threshold value Th ₁₀ read from the database 80, the operation finger by comparing the Monitor for contact.

When the "Yes" of step 1 is satisfied, that is, when the contact of the operating finger is detected (Step 1: Yes), the control unit 8 reads the load threshold value of the region where the contact is detected from the database 80 and reads the load signal. It is compared with the load based on S ₂ and whether or not the push operation is performed is monitored (Step 2).

Control unit 8, when the push operation force is not less than the load threshold is determined (Step3: Yes), the contact from the database 80 reads out the driving waveform of the detection area and generates a drive signal S ₃ , Output to the actuator 4 and present tactile feedback (Step 4).

Here, in step 3, the control unit 8 ends the process when the push operation is not determined (Step3: No) and the operation is not continued, that is, the contact of the operating finger is no longer detected (Step5: No). To do. Further, in step 5, when the contact of the operating finger is continuously detected (Step 5: Yes), the control unit 8 proceeds to step 3 to determine the push operation.

(Effect of embodiment)
The tactile presentation device 1 can suppress damage to the piezoelectric element 40 when an unexpected load is applied. Specifically, in the tactile presentation device 1, since the operation unit 2 and the piezoelectric element 40 do not come into direct contact with each other, it is expected that the pusher provided on the operation unit or the operation unit will come into direct contact with the piezoelectric element. It is possible to suppress damage to the piezoelectric element 40 when a heavy load is applied.

Since the tactile presenting device 1 is attached to a place where the pusher 5 has a large displacement of the metal shim 41, it is sufficient while suppressing a decrease in load detection accuracy as compared with the case where the pusher directly contacts the piezoelectric element. Can present tactile feedback.

The tactile presentation device 1 detects the load and presents the vibration by one actuator 4, and also sets a load threshold value for each region in order to suppress the variation in load detection due to the difference in the position where the operation is detected. A drive signal is defined for each region in order to suppress variations in tactile feedback due to differences in position. Since the upper region 23 to the right region 26 of the present embodiment are symmetrically located with the central region 27 in between, ideally, the load detected by the actuator 4 and the vibration feedback presented are the same in each region. , Actually different. Further, since the tactile presentation device 1 has one actuator 4, it can be easily miniaturized. Therefore, the tactile presentation device 1 can present sufficient tactile feedback while suppressing a decrease in load detection accuracy even if the size is reduced, as compared with the case where this configuration is not adopted.

Although some embodiments and modifications of the present invention have been described above, these embodiments and modifications are merely examples and do not limit the invention according to the claims. These novel embodiments and modifications can be implemented in various other embodiments, and various omissions, replacements, changes, etc. can be made without departing from the gist of the present invention. In addition, not all combinations of features described in these embodiments and modifications are essential as means for solving the problems of the invention. Further, these embodiments and modifications are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalent scope thereof.

1 ... Tactile presentation device, 2 ... Operation unit, 3 ... Touch sensor, 4 ... Actuator, 5 ... Pusher, 8 ... Control unit, 10 ... Support part, 12 ... Recession, 14 ... Mounting part, 20 ... Base, 23 ... Upper region, 24 ... lower region, 25 ... left region, 26 ... right region, 27 ... central region, 30 ... substrate, 30a ... front surface, 30b ... back surface, 31 ... electrode part, 40 ... piezoelectric element, 41 ... metal shim, 80 ... database, 200 ... operation surface, 400 ... first electrode, 401 ... piezoelectric body, 402 ... second electrode, 405 ... through hole

Claims (4)

An operation unit with an operation surface and
An actuator piezoelectric elements, and possess the piezoelectric element and a metal shim that is integrated, the piezoelectric element is positioned between the metal shim and the operation unit detects the added load on the operation surface,
A pusher provided on the back surface side of the operation unit and in contact with the metal shim ,
Equipped with a,
The piezoelectric element has a through hole and has a through hole.
The pusher is inserted into the through hole and deforms the piezoelectric element via the metal shim as the operation surface is pushed down.
Tactile presentation device. The piezoelectric element has a shape symmetrical with respect to the pusher.
The tactile presentation device according to claim 1. The actuator is configured to detect a load and add vibration to the operating surface.
A detection unit that detects the position of the operating finger in contact with the operating surface, and
A load threshold value determined for each region based on the load detected by applying a reference load for each of a plurality of regions defined on the operation surface, and a drive signal for each region for driving the actuator are set. A control unit that determines the operation based on the load threshold value of the region in which the operating finger is detected and drives the actuator by the drive signal corresponding to the region to present tactile feedback.
The tactile presentation device according to claim 1 or 2 . The through hole is formed at a position where the amplitude is large when the actuator is vibrating.
The pusher is inserted into the through hole and comes into contact with the metal shim at a position where the amplitude is large.
The tactile presentation device according to claim 3 .

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