Tactile presentation element and tactile presentation device

Abstract

To provide vibration type tactile sensation presenting elements that are capable of accurately presenting tactile sensations in minute regions.SOLUTION: A tactile sensation presenting element includes: a vibrator layer; and a first electrode layer and a second electrode layer located so as to face each other across the vibrator layer. At least one of the first electrode layer and the second electrode layer includes a plurality of electrodes that are electrically independent of one another. The vibrator layer includes a plurality of unit regions, in each of which occurrence of vibration can be independently controlled. The tactile sensation presenting element further includes a plurality of protrusions located opposite to the vibrator layer relative to the first electrode layer.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a tactile presentation element, and more particularly to a tactile presentation element that presents tactile sensations through vibrational stimulation. The present invention also relates to a tactile presentation device equipped with such a tactile presentation element. [Background technology]

[0002] In recent years, haptic feedback devices (sometimes called "haptic devices") that can provide users with tactile sensations have attracted attention and are increasingly being used in many applications such as medicine, education, entertainment, and remote control. Several types of haptic feedback devices are known.

[0003] The method of providing tactile sensations to users by applying vibrations, that is, by using vibrational stimulation (hereinafter referred to as the "vibration method"), is one of the most promising methods due to its small individual differences in tactile sensitivity and its superior safety. A tactile presentation element using the vibration method is disclosed, for example, in Patent Document 1. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2012-128499 [Overview of the project] [Problems that the invention aims to solve]

[0005] In vibration-based tactile feedback devices, tactile sensation is presented by generating vibrations using an actuator (e.g., a piezoelectric element) while a specific part of the human body (e.g., a finger) is in contact with the tactile feedback device. However, there is a problem in that users may perceive vibrations occurring at a location farther away from the specific body part than the actual location of the vibration. There is also the problem that users may perceive vibrations over a wider area than the actual location of the vibration. Thus, it is difficult to accurately present tactile sensations in minute areas using vibration-based tactile feedback devices.

[0006] Embodiments of the present invention have been made in view of the above-mentioned problems, and their object is to provide a vibration-type tactile presentation element that can accurately present tactile sensations to minute areas. [Means for solving the problem]

[0007] This specification discloses tactile feedback elements and tactile feedback devices as described in the following sections.

[0008] [Item 1] Vibrating layer and A first electrode layer and a second electrode layer are arranged to face each other via the vibrating body layer, A tactile presentation element comprising, At least one of the first electrode layer and the second electrode layer includes a plurality of electrodes that are electrically independent of each other. The vibrating layer includes a plurality of unit regions in which the generation of vibrations can be controlled independently of each other. A tactile presentation element further comprising a plurality of protrusions arranged on the opposite side of the first electrode layer from the vibrating body layer.

[0009] [Item 2] The tactile presentation element described in item 1, wherein the plurality of protrusions do not overlap the centers of each of the plurality of unit regions in a plan view.

[0010] [Item 3] The tactile presentation element according to item 1 or 2, wherein the plurality of protrusions include at least one first protrusion positioned to straddle the outer edge of at least one of the plurality of unit regions in a plan view.

[0011] [Item 4] The aforementioned at least one first projection is a plurality of first projections, Each of the aforementioned plurality of unit regions is substantially rectangular in plan view, The tactile presentation element according to item 3, wherein one or more of the multiple first protrusions straddle each side of the multiple unit regions in a plan view.

[0012] [Item 5] A tactile presentation element according to any one of items 1 to 4, further comprising a first substrate disposed between the first electrode layer and the plurality of protrusions and supporting the first electrode layer.

[0013] [Item 6] The present invention further comprises a second substrate, which is positioned on the opposite side of the piezoelectric layer from the second electrode layer and supports the second electrode layer, A tactile presentation element according to any one of items 1 to 5, wherein the thickness h [mm] of the second substrate and the Young's modulus E [GPa] of the second substrate satisfy the relationship E·h ≤ 1.95.

[0014] [Item 7] Each of the aforementioned plurality of unit regions is substantially rectangular in plan view, The tactile presentation element according to any one of items 1 to 6, wherein the height of each of the plurality of protrusions is at least twice the length of the shortest side among the plurality of sides of each unit region in a plan view.

[0015] [Item 8] Each of the aforementioned plurality of unit regions is substantially rectangular in plan view, The tactile presentation element according to any one of items 1 to 6, wherein the height of each of the multiple protrusions is at least three times the length of the shortest side among the multiple sides of each unit region in a plan view.

[0016] [Item 9] The cross-section of each of the plurality of protrusions has substantially the same shape over the height direction of each protrusion, the cross-sectional area A and height H of each of the plurality of protrusions satisfy the relationship of H≧(2·A 0.5 ) / π, the tactile presentation element according to any one of Items 1 to 8.

[0017] [Item 10] The shape of the cross-section of each of the plurality of protrusions is substantially circular, substantially elliptical, substantially rectangular, substantially equilateral triangular or substantially regular convex polygonal, the tactile presentation element according to Item 9.

[0018] [Item 11] The Young's modulus of each of the plurality of protrusions is 20 GPa or less, the tactile presentation element according to any one of Items 1 to 10.

[0019] [Item 12] The plurality of electrodes are a plurality of unit electrodes respectively corresponding to each of the plurality of unit regions, the tactile presentation element according to any one of Items 1 to 11.

[0020] [Item 13] The plurality of unit electrodes are 9 or more unit electrodes arranged in m rows and n columns (m and n are integers of 3 or more respectively), the tactile presentation element according to Item 12.

[0021] [Item 14] Each of the first electrode layer and the second electrode layer includes the plurality of electrodes, the plurality of electrodes included in the first electrode layer are a plurality of first strip electrodes extending along a predetermined direction, the plurality of electrodes included in the second electrode layer are a plurality of second strip electrodes extending along a direction intersecting with the predetermined direction, the tactile presentation element according to any one of Items 1 to 11.

[0022] [Item 15] A second substrate, which is positioned on the opposite side of the piezoelectric layer from the second electrode layer and supports the second electrode layer, having a first region that overlaps in a plan view with the region encompassing the plurality of unit regions of the vibrating body layer, and a second region that is located outside the first region in a plan view, A fixing device bonded to the second region of the second substrate and for fixing the second region, A haptic presentation element described in any of items 1 to 14, further comprising the above.

[0023] [Item 16] The first electrode layer includes the plurality of unit electrodes, The aforementioned second electrode layer contains only a single common electrode. The common electrode has a first region that overlaps in a plan view with the region encompassing the plurality of unit regions of the vibrating body layer, and a second region that is located outside the first region in a plan view. The tactile presentation element according to item 12 or 13, further comprising a fixing device joined to the second region of the common electrode and fixing the second region.

[0024] [Item 17] The tactile presentation element according to any one of items 1 to 16, wherein the vibrating layer is a piezoelectric layer formed from a piezoelectric material.

[0025] [Item 18] The piezoelectric layer comprises a plurality of portions separated from each other, as described in item 17.

[0026] [Item 19] The vibrating layer includes an induction coil for each of the plurality of unit regions, as described in any one of items 1 to 16.

[0027] [Item 20] A tactile presentation element described in any of items 1 through 19, A control device for controlling the tactile presentation element, A tactile presentation device equipped with the following features. [Effects of the Invention]

[0028] According to embodiments of the present invention, a vibration-type tactile presentation element can be provided that can accurately present tactile sensations to minute areas. [Brief explanation of the drawing]

[0029] [Figure 1] This is a schematic block diagram showing a tactile presentation device 100 equipped with a tactile presentation element 1 according to an embodiment of the present invention. [Figure 2] This is a diagram to explain the fingertip pad (fp). [Figure 3] This is a schematic cross-sectional view of the tactile feedback element 1. [Figure 4A] This is a schematic plan view of the haptic presentation element 1, and is a view of the haptic presentation element 1 from the front. [Figure 4B] This is a schematic plan view of the tactile feedback element 1, with the first substrate 40 and the protrusions 50 omitted. [Figure 5] This is a schematic plan view showing the common electrode (second electrode layer) 30 of the tactile presentation element 1. [Figure 6] This figure shows an example of the equivalent circuit of the tactile feedback element 1. [Figure 7] This is a schematic cross-sectional view of a comparative example tactile presentation element 901. [Figure 8] This is a schematic plan view of the haptic presentation element 901, and shows the haptic presentation element 901 as viewed from the front. [Figure 9] This is a schematic plan view of the tactile feedback element 901, with the first substrate 40 omitted. [Figure 10] This diagram illustrates the mechanism by which the tactile feedback element 1 is effective. [Figure 11] This figure shows the tactile presentation element 901 of the comparative example being pressed firmly by finger F. [Figure 12A] This is a schematic cross-sectional view showing another tactile presentation element 1A according to an embodiment of the present invention. [Figure 12B] This is a schematic plan view showing the second substrate 70 of the tactile presentation element 1A. [Figure 13A] This figure shows another example of the arrangement of the protrusions 50. [Figure 13B] This figure shows yet another example of the arrangement of the protrusions 50. [Figure 14A] This is a screenshot of the vibration simulation results, showing the case where the thickness h and Young's modulus E of the second substrate 70 are 0.13 mm and 10 GPa, respectively. [Figure 14B] This is a screenshot of the vibration simulation results, showing the case where the thickness h and Young's modulus E of the second substrate 70 are 0.13 mm and 15 GPa, respectively. [Figure 14C] This is a screenshot of the vibration simulation results, showing the case where the thickness h and Young's modulus E of the second substrate 70 are 0.13 mm and 18 GPa, respectively. [Figure 14D] This is a screenshot of the vibration simulation results, showing the case where the thickness h and Young's modulus E of the second substrate 70 are 0.13 mm and 20 GPa, respectively. [Figure 15] This is a schematic cross-sectional view showing yet another tactile presentation element 1B according to an embodiment of the present invention. [Figure 16] This is a schematic exploded perspective view showing the tactile feedback element 1B. [Figure 17] This is a schematic plan view of the tactile feedback element 1B, with the first substrate 40 and the protrusions 50 omitted. [Figure 18] This is an exploded perspective view schematically showing yet another tactile presentation element 1C according to an embodiment of the present invention. [Figure 19] This is a schematic cross-sectional view showing a portion of the haptic feedback element 1C. [Figure 20] This is a perspective view showing an example of an induction coil 13. [Figure 21] This is a cross-sectional view showing an example of another configuration of the tactile feedback element 1C. [Modes for carrying out the invention]

[0030] Embodiments of the present invention will be described below with reference to the drawings. However, the present invention is not limited to the following embodiments.

[0031] Referring to Figure 1, a haptic presentation device 100 equipped with a haptic presentation element 1 according to an embodiment of the present invention will be described. Figure 1 is a schematic block diagram showing the haptic presentation device 100. In addition to the haptic presentation device 100, Figure 1 also shows a personal computer (PC) 210 and a head-mounted display (HMD) 220.

[0032] As shown in Figure 1, the tactile presentation device 100 comprises at least one tactile presentation element 1 and a control device 2 that controls the tactile presentation element 1. In the illustrated example, the tactile presentation device 100 comprises multiple tactile presentation elements 1, more specifically, five tactile presentation elements 1. However, the number of tactile presentation elements 1 is not limited to five.

[0033] When the haptic presentation device 100 is used, the five haptic presentation elements 1 are positioned to touch the fingertips of the five fingers F of the user's hand H (shown by dotted lines in Figure 1). Each haptic presentation element 1 presents tactile sensation to the fingertip pad of one finger F by vibration stimulation. Here, "fingertip pad" refers to the area fp located beyond the first joint j1 of the finger F, and which is located on the palm side of the center when the finger F is viewed from the side, as shown in Figure 2.

[0034] The control device 2 controls the haptic feedback element 1. The control device 2 controls the haptic feedback element 1 based on control signals transmitted from the PC 210. Data communication between the control device 2 and the PC 210 may be performed by wireless communication or by wired communication. Wireless and wired communication may be performed in accordance with various known communication standards. The control device 2 is implemented, for example, by a microcomputer.

[0035] The tactile feedback element 1 is wired using a flexible substrate and wiring, so as not to interfere with the movement of the hand H. The control device 2 may be positioned, for example, in a part corresponding to the user's arm. The tactile feedback element 1 and the control device 2 may be integrated into a glove.

[0036] The PC210 outputs a video signal to the HMD220, and the HMD220 displays the video signal based on the received signal. The HMD220 also outputs position tracking data, which is information about the HMD220's position, to the PC210. ​​Data communication between the PC210 and the HMD220 may be performed wirelessly or via wired communication.

[0037] In this example, the haptic presentation device 100 presents tactile sensations in conjunction with the display on the HMD220, but the uses of the haptic presentation device 100 are not limited to this.

[0038] The specific configuration of the tactile feedback element 1 will be explained with reference to Figures 3, 4A, and 4B. Figure 3 is a schematic cross-sectional view of the tactile feedback element 1. Figures 4A and 4B are schematic plan views of the tactile feedback element 1, respectively, and are views of the tactile feedback element 1 as seen from the front. In Figure 4B, some of the components of the tactile feedback element 1 (the first substrate 40 and the protrusion 50, which will be described later) are omitted.

[0039] As shown in Figures 3, 4A, and 4B, the tactile presentation element 1 comprises a vibrating body layer 10, a first electrode layer 20, a second electrode layer 30, and a first substrate 40. The tactile presentation element 1 also further comprises a plurality of protrusions 50 and a fixing device 60. In the illustrated example, the tactile presentation element 1 is substantially rectangular in plan view, but the planar shape of the tactile presentation element 1 is not limited to a substantially rectangular shape.

[0040] The vibrating layer 10 is a layer that undergoes physical deformation in response to an applied voltage or current, thereby generating vibration. Here, the vibrating layer 10 is a piezoelectric layer formed from a piezoelectric material. Various known piezoelectric materials can be used as the piezoelectric material, and for example, piezoelectric ceramics such as zinc zirconate titanate (PZT) and barium titanate (BaTiO3) can be suitably used. The piezoelectric material may also be a material in which piezoelectric ceramic particles are dispersed in a resin material. Furthermore, piezoelectric materials other than piezoelectric ceramics (for example, piezoelectric single crystals such as quartz) may also be used.

[0041] There are no particular restrictions on the thickness of the piezoelectric layer 10. When piezoelectric ceramics are used as the piezoelectric material, the thickness of the piezoelectric layer 10 is preferably, for example, 0.2 mm or more from the viewpoint of ensuring sufficient torque, and preferably, for example, 0.19 mm or less from the viewpoint of ensuring displacement or reducing the driving voltage. Furthermore, when piezoelectric ceramic particles dispersed in a resin material are used as the piezoelectric material, the thickness of the piezoelectric layer 10 is preferably, for example, 0.50 mm or more from the viewpoint of ensuring sufficient torque, and preferably, for example, 0.25 mm or less from the viewpoint of ensuring displacement or reducing the driving voltage.

[0042] Note that the vibrating layer is not limited to those exemplified. Organic actuators using PVDF (polyvinylidene fluoride) or ion-conductive polymers, or layers containing minute induction coils as described later, may also be used as the vibrating layer. Since PVDF is a type of piezoelectric material, an organic actuator using PVDF can also be called a piezoelectric layer.

[0043] The piezoelectric layer 10 has two opposing main surfaces 10a and 10b. Hereinafter, of these main surfaces 10a and 10b, the main surface 10a located on the front side (finger F side) will be referred to as the "first main surface," and the main surface 10b located on the back side will be referred to as the "second main surface."

[0044] The first electrode layer 20 and the second electrode layer 30 are arranged to face each other via the piezoelectric layer 10. The first electrode layer 20 is provided in contact with the first main surface 10a of the piezoelectric layer 10. The second electrode layer 30 is provided in contact with the second main surface 10b of the piezoelectric layer 10.

[0045] The first electrode layer 20 is divided into a plurality of electrodes 21 that are electrically independent of each other. In the illustrated example, the plurality of electrodes 21 are 25 electrodes 21 arranged in a 5x5 grid, and each electrode 21 is approximately rectangular (more specifically, approximately square) in plan view. Of course, the number and shape of the electrodes 21 are not limited to those illustrated here. The first electrode layer 20 can be formed from various known conductive materials, and can preferably be formed from metals such as copper (Cu), nickel (Ni), silver (Ag), and gold (Au), alloys such as Al-Nd alloy (aluminum-neodymium alloy), or metal oxides such as indium tin oxide (ITO). There are no particular restrictions on the thickness of the first electrode layer 20 containing the plurality of electrodes 21, but for example, it is 50 nm to 200 nm.

[0046] The second electrode layer 30 is not divided into multiple electrodes, but is a single electrode (hereinafter sometimes referred to as the "common electrode"). In the illustrated example, the second electrode layer (common electrode) 30 is substantially rectangular in plan view. The second electrode layer 30 can be formed from various known conductive materials, and can be suitably formed from metals such as brass, copper (Cu), and aluminum (Al). There are no particular restrictions on the thickness of the second electrode layer 30, but it is, for example, 0.01 mm or more and 0.2 mm or less.

[0047] When a voltage is applied between the second electrode layer (common electrode) 30 and each electrode 21 of the first electrode layer 20, deformation occurs in the piezoelectric layer 10. More specifically, the region of the piezoelectric layer 10 to which the voltage is applied expands and contracts in the thickness direction. The potentials of the common electrode 30 and each electrode 21 of the first electrode layer 20 are controlled by the control device 2 (more specifically by signals output from the control device 2).

[0048] In the example shown here, deformation of the piezoelectric layer 10 occurs in each region 11 of the piezoelectric layer 10 corresponding to each electrode 21 of the first electrode layer 20 (see Figures 3 and 4A). In other words, the piezoelectric layer (vibrating layer) 10 contains multiple regions 11 in which the generation of vibration can be controlled independently of each other. Hereafter, each of these regions 11 of the piezoelectric layer 10 will be referred to as a "unit region". Also, since each unit region 11 of the piezoelectric layer 10 is defined by each electrode 21 of the first electrode layer 20, each electrode 21 that defines each unit region 11 (i.e., corresponding to each unit region 11) will be referred to as a "unit electrode". The shape of the unit region 11 in plan view is the same as the shape of the unit electrode 21 (approximately rectangular in the illustrated example). Also below, the region 12 of the piezoelectric layer (vibrating layer) 10 that encompasses multiple unit regions 11 will be referred to as a "vibration region". The outline of the vibration region 12 is shown by the dashed line in Figure 4A. In the illustrated example, the vibration region 12 is approximately rectangular in plan view.

[0049] The first substrate 40 is positioned on the opposite side of the piezoelectric layer 10 from the first electrode layer 20 (i.e., on the front side of the first electrode layer 20) and supports the first electrode layer 20. The first substrate 40 is insulating. Furthermore, the first substrate 40 is flexible enough to deform in accordance with the deformation of the piezoelectric layer 10.

[0050] The first substrate 40 may be a resin substrate (plastic substrate) formed from a resin material (e.g., polyimide). The first substrate 40 may also be a film. The thickness of the first substrate 40 is, for example, 10 μm or more and 100 μm or less.

[0051] The multiple protrusions 50 project from the first substrate 40 toward the side opposite to the first electrode layer 20. In other words, the multiple protrusions 50 are positioned on the side opposite to the piezoelectric layer 10 relative to the first electrode layer 20. It can also be said that the first substrate 40 is positioned between the first electrode layer 20 and the multiple protrusions 50. In the illustrated example, each of the multiple protrusions 50 is cylindrical. That is, the cross-section of each protrusion is substantially the same shape along the height direction of each protrusion 50 and is approximately circular. Also, in the illustrated example, as shown in Figure 4A, the multiple protrusions 50 do not overlap the centers of each of the multiple unit regions 11 in a plan view. Furthermore, each protrusion 50 is positioned to straddle the outer edge of one or two unit regions 11 in a plan view, with one protrusion 50 straddling each side of each unit region 11. The protrusions 50 are preferably formed from a resin material such as polyethylene, but may also be formed from a metallic material such as copper (Cu).

[0052] The fixing device 60 is positioned on the opposite side of the piezoelectric layer 10 from the second electrode layer (common electrode) 30. The fixing device 60 is joined to the outer circumference of the common electrode 30 and fixes the outer circumference of the common electrode 30. Here, as shown in Figure 5, if we refer to the region 30a of the common electrode 30 that overlaps with the vibration region 12 of the piezoelectric layer 10 in a plan view as the "first region," and the region 30b that is located outside the first region 30a in a plan view (surrounding the first region 30a in the illustrated example) as the "second region," then it can also be said that the fixing device 60 is joined to the second region 30b of the common electrode 30 and fixes the second region 30b of the common electrode 30. In the illustrated example, the first region 30a is roughly rectangular. The second region 30b is roughly square and includes four sides 30b1, 30b2, 30b3, and 30b4.

[0053] In the illustrated example, the fixing device 60 is box-shaped with an open top and has a bottom portion 61 and a side wall portion 62 that protrudes from the outer circumference of the bottom portion 61 toward the second electrode layer 30. The side wall portion 62 of the fixing device 60 is joined to the second region 30b of the common electrode 30. Note that the fixing device 60 does not necessarily need to fix all four sides 30b1, 30b2, 30b3 and 30b4 of the second region 30b, and may fix only some of the sides. For example, the fixing device 60 may fix only a pair of opposing sides (only sides 30b1 and 30b3, or only sides 30b2 and 30b4). The fixing device 60 may also be omitted.

[0054] Although not shown in Figures 3, 4A, and 4B, wiring and the like for driving multiple unit electrodes 21 (i.e., applying a signal (voltage) to each unit electrode 21) are provided on the main surface of the first substrate 40 on the piezoelectric layer 10 side. Figure 6 is a diagram showing an example of the equivalent circuit of the tactile presentation element 1. In the example shown in Figure 6, the tactile presentation element 1 has multiple gate wirings GL, multiple source wirings SL, and multiple transistors Tr.

[0055] Each of the multiple transistors Tr is provided corresponding to each unit electrode 21. The gate electrode of the transistor Tr is electrically connected to the corresponding gate wiring GL. The source electrode of the transistor Tr is electrically connected to the corresponding source wiring SL, and the drain electrode of the transistor Tr is electrically connected to the corresponding unit electrode 21. A predetermined signal (voltage) is applied to each unit electrode 21 via the transistor Tr, so that deformation (expansion and contraction) of the piezoelectric layer 10 can be independently caused in the region (unit region 11) corresponding to each unit electrode 21, thereby generating vibration. The frequency of the vibration is preferably, for example, 10 Hz or more and 300 Hz or less. However, vibration stimulation may be performed by amplitude modulation (AM) of vibration in the ultrasonic range (20 kHz or more).

[0056] As described above, in the tactile presentation element 1 of this embodiment, the first electrode layer 20 is divided into a plurality of electrically independent electrodes 21, so there are multiple vibration channels, and the resolution of the presented tactile sensation can be increased. Furthermore, the tactile presentation element 1 of this embodiment is equipped with a plurality of protrusions 50, which improves the problem that the user may perceive vibration as occurring in a location farther away from the actual location of vibration, or that the user may perceive vibration over a wider area than the actual location of vibration. This point will be explained below in comparison with the comparative example tactile presentation element 901 shown in Figures 7 to 9.

[0057] Figure 7 is a schematic cross-sectional view of the haptic presentation element 901 of the comparative example. Figures 8 and 9 are schematic plan views of the haptic presentation element 901, respectively, and are views of the haptic presentation element 901 as seen from the front. In Figure 9, some of the components of the haptic presentation element 901 (first substrate 40) are omitted.

[0058] As shown in Figures 7, 8, and 9, the comparative example tactile presentation element 901 comprises a piezoelectric layer 10, a first electrode layer 20, a second electrode layer 30, a first substrate 40, and a fixing device 60, similar to the tactile presentation element 1 of this embodiment. However, unlike the tactile presentation element 1 of this embodiment, the comparative example tactile presentation element 901 does not have multiple protrusions 50. The comparative example tactile presentation element 901 was prototyped according to the specifications shown in Table 1, and the presented tactile sensation was verified.

[0059] [Table 1]

[0060] As shown in Table 1, the side length L1 of the tactile presentation element 901 in a plan view was 7.0 mm. Similarly, the side lengths of the piezoelectric layer 10, the second electrode layer 30, the first substrate 40, and the fixing device 60 in a plan view were also 7.0 mm. The piezoelectric layer 10 was formed from PZT with a thickness of 0.19 mm. The first electrode layer 20, which contains 25 unit electrodes 21 arranged in a 5x5 grid, was formed from copper (Cu) with a thickness of 100 nm. Each unit electrode 21 was square with a side length L2 of 0.8 mm, and the spacing S1 between adjacent unit electrodes 21 was 0.2 mm. The vibration region 12 of the piezoelectric layer 10 is square with a side length L3 of 4.8 mm in a plan view. The second electrode layer (common electrode) 30 was formed from brass with a thickness of 0.13 mm.

[0061] A first substrate 40 was formed from polyimide with a thickness of 50 μm. The first substrate 40, on which the first electrode layer 20 was formed, was attached to the piezoelectric layer 10 with an adhesive. A fixing device 60 was formed from acrylic resin. The thickness T1 of the bottom portion 61 of the fixing device 60 was 1.0 mm, and the height H1 of the side wall portion 62 was 2.0 mm (i.e., the overall height H2 of the fixing device 60 was 3.0 mm). The fixing device 60 was bonded to the outer periphery of the second electrode layer 30.

[0062] A predetermined signal was output to each unit electrode 21 and the common electrode 30 of the prototype haptic feedback element 901 to generate vibration. The refresh rate was set to 200 Hz, and the gate open time for the region corresponding to each unit electrode 21 was set to 0.2 ms.

[0063] When the tactile sensation presented was evaluated with a finger F in contact with the surface of the first substrate 40 of the prototype haptic presentation element 901, it was possible to obtain a sensation as if the materials were different by varying the output signals. However, it felt as if the source of the vibration was located not on the surface of finger F, but about 1 cm away. This is thought to be because the vibrations propagate laterally within the tactile presentation element 901, causing multiple sensory receptors to perceive vibrations of similar intensity. As a result, the brain empirically processes and judges the vibration source in this way (i.e., perceiving it as being further away from the surface of finger F).

[0064] A prototype of the tactile presentation element 1 of this embodiment was also fabricated, and the tactile sensation it presented was verified. The materials and size (thickness, etc.) of the piezoelectric layer 10, the first electrode layer 20, the second electrode layer 30, the first substrate 40, and the fixing device 60 were the same as those of the tactile presentation element 901 of the comparative example. The specifications of the protrusions 50 are as shown in Table 2. As shown in Table 2, a plurality of cylindrical protrusions 50 were formed from polyethylene, with a height H of 3.0 mm and a diameter D1 of 0.5 mm for each protrusion 50.

[0065] [Table 2]

[0066] A predetermined signal was output to each unit electrode 21 and the common electrode 30 of the prototype haptic presentation element 1 to generate vibration. The refresh rate was set to 200 Hz, and the gate open time for the region corresponding to each unit electrode 21 was set to 0.2 ms.

[0067] When the tactile sensation presented was evaluated with a finger F in contact with the top surface of the protrusion 50 of the prototype tactile presentation element 1, it was possible to obtain a sensation as if the material were different by varying the output signal. Furthermore, it felt as if the vibration source was present on the surface of finger F. In addition, compared to the case where the same signal was output with the comparative example tactile presentation element 901, it felt smoother and the tactile sensation was more refined. In other words, vibrations were felt over a narrower area than with the comparative example tactile presentation element 901.

[0068] Thus, the tactile presentation element 1 of this embodiment can accurately present tactile sensations to a minute area. The mechanism by which such an effect is obtained is presumed to be as follows.

[0069] Figure 10 is a diagram illustrating the mechanism described above. Note that the first electrode layer 20, the second electrode layer 30, and the first substrate 40 are not shown in Figure 10.

[0070] As shown in Figure 10, when vibration occurs, the projection 50 deforms, causing the contact area with the finger F to change spatially and temporally within a small region. This results in a difference in the intensity of vibration felt between adjacent sensory receptors, and it is thought that the brain processes this to recognize that the vibration source is located on the surface of the finger F. For example, in vision, it is known that the brain processes and recognizes an object as far away when the difference in distance between the left and right eyes is small, and as close when the difference is large, and it is presumed that a similar mechanism is at play.

[0071] Furthermore, the tactile feedback element 1 of this embodiment also provides the following effects.

[0072] In the comparative example tactile presentation element 901, which does not have the protrusion 50, as shown in Figure 11 (similar to Figure 10, the first electrode layer 20, the second electrode layer 30, and the first substrate 40 are omitted from the illustration), if the tactile presentation element 901 is pressed hard by a finger F, there is a risk that it will not be able to generate vibration due to insufficient torque.

[0073] In contrast, in the tactile presentation element 1 of this embodiment, since a protrusion 50 exists between the piezoelectric layer 10 and the finger F, even if the tactile presentation element 1 is pressed firmly by the finger F, sufficient vibration can be generated by the lateral deformation of the protrusion 50 as shown in Figure 10.

[0074] In this embodiment, the tactile presentation element 1 is not typically used by tracing with a finger F, so macroscopically, the relative position between the tactile presentation element 1 and the finger F is fixed (however, microscopic fluctuations in the relative position may occur due to the slight vibration of the protrusion 50 caused by the driving of the tactile presentation element 1). Therefore, the area of ​​the vibration region 12 in one tactile presentation element 1 (i.e., corresponding to the fingertip pad fp of one finger F) is, for example, 9 cm². 2The following applies:

[0075] [Regarding the height of the projections and Young's modulus] From the viewpoint of suitably causing lateral deformation of the projection 50, it is preferable that the height H of the projection 50 is relatively large. When each unit region 11 is substantially rectangular in plan view, the height H of each projection 50 is preferably at least twice the length of the shortest side (the short side in the case of a rectangle, or each side in the case of a square) among the multiple sides of each unit region 11 in plan view, and more preferably at least three times.

[0076] Furthermore, from the viewpoint of suitably causing lateral deformation in the projection 50, it is preferable that the projection 50 is elongated, that is, that the aspect ratio (ratio of height to width) of the projection 50 is high. As illustrated, if the cross-section of each projection 50 has substantially the same shape along the height direction of each projection 50, this can be expressed mathematically as follows: the cross-sectional area A and height H of each projection 50 are such that H ≥ (2·A 0.5 It is preferable that the relationship ) / π is satisfied.

[0077] Furthermore, the cross-sectional shape of each projection 50 is not limited to the approximately circular shape exemplified, but may be, for example, approximately elliptical, approximately rectangular, approximately equilateral triangle, or approximately regular convex polygon, or other shapes. In addition, parts of the projections 50 may be joined to the extent that they can be roughly considered projections in shape or to the extent that they do not hinder lateral vibration. For example, in order to prevent foreign matter from entering between the projections 50, the top surfaces of multiple projections 50 may be joined with a very thin film (for example, a film with a thickness of 10 μm and made from polyvinylidene chloride (PVDC), polyvinyl chloride resin (PVC), polymethylpentene (PMP), or polyethylene (PE)).

[0078] Furthermore, from the viewpoint of suitably causing lateral deformation in the protrusions 50, it is preferable that the Young's modulus of each protrusion 50 be relatively small, specifically, 20 GPa or less.

[0079] [Regarding the number of unit electrodes] In the above description, a configuration in which the first electrode layer 20 includes 25 unit electrodes 21 is used as an example, but the number of unit electrodes 21 can be 2 or more, and is not limited to 25. When the second electrode layer 30 is a common electrode (i.e., not divided into multiple unit electrodes), from the viewpoint of increasing the fineness of tactile sensation, it is preferable that the multiple unit electrodes 21 of the first electrode layer 20 consist of 9 or more unit electrodes 21 arranged in m rows and n columns (where m and n are integers of 3 or more) (i.e., divided into 9 or more sections).

[0080] [Configuration with a second circuit board] Another tactile feedback element 1A according to an embodiment of the present invention will be described with reference to Figure 12A. Figure 12A is a schematic cross-sectional view showing a tactile feedback element 1A.

[0081] In the tactile presentation element 1 shown in Figure 3, the second electrode layer 30, unlike the first electrode layer 20, is not directly supported by the substrate. In other words, the second electrode layer 30 is relatively thick enough to be self-supporting.

[0082] The tactile presentation element 1A shown in Figure 12A differs from the tactile presentation element 1 in that it is positioned on the opposite side of the piezoelectric layer 10 from the second electrode layer 30 and includes a second substrate 70 that supports the second electrode layer 30.

[0083] In the tactile presentation element 1A, the second electrode layer 30 may be relatively thin to the extent that self-supporting is difficult. The second electrode layer 30 can preferably be formed from metals such as copper (Cu), nickel (Ni), silver (Ag), and gold (Au), alloys such as Al-Nd alloy (aluminum-neodymium alloy), or metal oxides such as indium tin oxide (ITO). The thickness of the second electrode layer 30 is, for example, 50 nm to 200 nm.

[0084] The second substrate 70 is insulating. Furthermore, the second substrate 70 has a degree of flexibility that allows it to deform in accordance with the deformation of the piezoelectric layer 10. The second substrate 70 may be a resin substrate (plastic substrate) formed from a resin material (e.g., PET or polyimide). The second substrate 70 may also be a film. The thickness of the second substrate 70 is, for example, 10 μm or more and 100 μm or less.

[0085] The fixing device 60 is joined to the outer periphery of the second substrate 70 and fixes the outer periphery of the second substrate 70. Here, as shown in Figure 12B, if we refer to the region 70a of the second substrate 70 that overlaps with the vibration region 12 of the piezoelectric layer 10 in a plan view as the "first region," and the region 70b that is located outside the first region 70a in a plan view (surrounding the first region 70a in the illustrated example) as the "second region," then it can also be said that the fixing device 60 is joined to the second region 70b of the second substrate 70 and fixes the second region 70b of the second substrate 70.

[0086] The behavior of the tactile presentation element 1A shown in Figure 12A and the tactile presentation element 1 shown in Figure 3, etc., when presenting tactile sensations was verified by vibration simulation. For the simulation, Altair's HyperMesh was used as the preprocessing software and Altair's OptiStruct was used as the solver. During the simulation, the piezoelectric layer 10, the first electrode layer 20, the first substrate 40, the protrusion 50, and the fixing device 60 were specified as shown in Tables 1 and 2. The second electrode layer 30 of the tactile presentation element 1 was specified as shown in Table 1. The second substrate 70 of the tactile presentation element 1A was assumed to be made of resin material and have a thickness of 0.05 mm, while the second electrode layer 30 of the tactile presentation element 1A was not considered because it is very thin (thickness 100 nm).

[0087] The vibration intensity in haptic element 1A and haptic element 1 was evaluated through simulation. The vibration intensity was measured using the magnitude M [mm], which is expressed by the following formula. M=Δx 2 +Δy 2 +Δz 2

[0088] Here, Δx, Δy, and Δz are displacements in the x, y, and z axes, respectively. The x, y, and z axes are three mutually orthogonal axes, and the z axis is parallel to the normal direction (height direction of the projection 50) of the main surfaces 1a and 1b of the piezoelectric layer 10.

[0089] The results of the above simulation verification confirmed that the magnitude directly above the vibration source (the deformed portion of the piezoelectric layer 10) is relatively higher in tactile presentation element 1A than in tactile presentation element 1. Therefore, it can be said that tactile presentation element 1A provides a higher level of tactile precision than tactile presentation element 1.

[0090] [Regarding the arrangement of protrusions, the thickness of the second substrate, etc.] In the example shown in Figure 4A, each projection 50 does not overlap the center of the unit region 11 in a plan view, but is positioned to straddle the outer edge of the unit region 11. However, the arrangement of the projections 50 is not limited to this example.

[0091] Figure 13A shows another example of the arrangement of the protrusions 50. In the example shown in Figure 13A, each protrusion 50 overlaps the center of the unit region 11 in a plan view. Also, each protrusion 50 does not straddle the outer edge of the unit region 11 in a plan view.

[0092] Figure 13B shows yet another example of the arrangement of the protrusions 50. In the example shown in Figure 13B, each protrusion 50 does not overlap the center of the unit region 11 in plan view. Also, each protrusion 50 does not straddle the outer edge of the unit region 11 in plan view.

[0093] Instead of the arrangement shown in Figure 4A, the arrangements shown in Figures 13A and 13B may be adopted. However, according to the inventor's research, the arrangement in which the projection 50 does not overlap with the center of the unit electrode 21, as shown in Figures 4A and 13B, is preferable to the arrangement in which the projection 50 overlaps with the center of the unit electrode 21, as shown in Figure 13A. This point will be explained below.

[0094] For a configuration including a second substrate 70, as shown in Figure 12A for the tactile presentation element 1A, vibration simulations were performed for the arrangement of the protrusions 50 shown in Figure 4A (hereinafter referred to as "protrusion arrangement A") and the arrangement of the protrusions 50 shown in Figure 13A (hereinafter referred to as "protrusion arrangement B"). For the simulations, as with the verification already described, Altair's HyperMesh was used as the preprocessing software and Altair's OptiStruct as the solver. The piezoelectric layer 10, first electrode layer 20, first substrate 40, protrusions 50, and fixing device 60 were as shown in Tables 1 and 2 (however, the material of the fixing device 60 was iron), and the second electrode layer 30 was not considered because it is very thin (thickness 100 nm). The Young's modulus, Poisson's ratio, and density of the protrusions 50, first substrate 40, piezoelectric layer 10, second substrate 70, and fixing device 60 were as shown in Table 3.

[0095] [Table 3]

[0096] Tables 4, 5, and 6 show the simulation results obtained by varying the thickness h [mm] and Young's modulus E [GPa] of the second substrate 70, respectively. Additionally, Figures 14A, 14B, 14C, and 14D show the simulation results for some of the conditions.

[0097] [Table 4]

[0098] [Table 5]

[0099] [Table 6]

[0100] Tables 4, 5, and 6 show the magnitude and the location of the maximum amplitude. In the simulation, the vibration source was set to the center of the piezoelectric layer 10 in a plan view. In the tables, when the location of the maximum amplitude is a protrusion 50 located directly above the vibration source (for example, the four protrusions 50 located near the center in the example shown in Figure 4A), it is referred to as "center," and when the location of the maximum amplitude is a protrusion 50 located off-center from the vibration source, it is referred to as "periphery." It is preferable that the magnitude be as large as possible, and that the location of the maximum amplitude be at the center. Also, in Figures 14A, 14B, 14C, and 14D, the magnitude is shown by shades of gray, with darker colors indicating a larger magnitude and lighter colors indicating a smaller magnitude. Figures 14A and 14B are examples where the location of the maximum amplitude is at the center, and Figures 14C and 14D are examples where the location of the maximum amplitude is at the periphery (i.e., off-center).

[0101] Furthermore, Tables 4, 5, and 6 show not only the thickness h and Young's modulus E of the second substrate 70, but also their product E·h. This parameter E·h can be used as an index representing stiffness for the following reasons.

[0102] The relationship between load F and displacement d is given by F = k·d in the linear range, where k is the spring constant and represents stiffness that includes both material-induced and shape-induced stiffness.

[0103] On the other hand, stress σ is expressed as σ = ε·E using strain ε and Young's modulus E. From this equation, using load F, cross-sectional area S, length L, and the definitions of stress σ and strain ε, we obtain the equation F / S = (ΔL / L)·E. Furthermore, if we assume that the displacement d corresponds to ΔL (d = ΔL), we obtain the equation k = (E·S) / L. In this equation, E represents the stiffness due to the material, and S / L represents the stiffness due to the shape. Also, if we consider that the cross-sectional area S corresponds to the product of length L and thickness h (i.e., S = L·h), then k = E·h, so the parameter E·h can be considered to represent a certain type of stiffness.

[0104] As can be seen from Tables 4, 5, and 6, when the parameter E·h is relatively small (i.e., the stiffness is relatively low), the maximum amplitude position tends to be in the center; when the parameter E·h is relatively large (i.e., the stiffness is relatively high), the maximum amplitude position tends to be in the periphery; and when the parameter E·h is extremely large (i.e., the stiffness is extremely high), the maximum amplitude position tends to be in the center. This is presumed to be because as the stiffness increases, vibrations can travel further in the lateral direction, but when the stiffness becomes extremely high, vibrations become less likely to be transmitted.

[0105] In protrusion configuration B, if the thickness of the second substrate 70 is 0.13 mm, for the maximum amplitude position to be at the center, as can be seen from Table 5, the Young's modulus E of the second substrate 70 must be 1 GPa or less, or about 20,000 GPa (100 times that of iron). Considering that the Young's modulus of resin is about 2 GPa, setting the Young's modulus E of the second substrate 70 in that way is not very practical. In protrusion configuration B, if the thickness of the second substrate 70 is half of 0.13 mm, i.e., 0.065 mm, the point of change in the maximum amplitude position is in the range of 2 GPa to 4 GPa, so even if a material with a Young's modulus at the same level as the resin is used for the second substrate 70, the maximum amplitude position can be made at the center.

[0106] In protrusion configuration A, when the thickness of the second substrate 70 is 0.13 mm, as can be seen from Table 5 (and further from the comparison between Figures 14A and 14B and Figures 14C and 14D), the maximum amplitude position can be centered if the Young's modulus E of the second substrate 70 is 15 GPa or less. Also, in protrusion configuration A, when the thickness of the second substrate 70 is 0.065 mm, as can be seen from Table 4, the maximum amplitude position can be centered if the Young's modulus E of the second substrate 70 is 20 GPa or less.

[0107] Thus, in terms of broadening the range of materials and thicknesses that can be used for the second substrate 70, protrusion arrangement A is preferable to protrusion arrangement B. Furthermore, in protrusion arrangement A, if the parameter E·h is 1.95 GPa or less, that is, if the thickness h [mm] and Young's modulus E [GPa] of the second substrate 70 satisfy the relationship E·h ≤ 1.95, the maximum amplitude position can be centered, which is preferable.

[0108] It might seem preferable to adopt protrusion arrangement B because it results in a larger vibration amplitude than protrusion arrangement A. However, contrary to this common technical understanding, a new finding has been discovered, as described above, that an arrangement in which the protrusions 50 do not overlap the center of the unit region 11 is preferable to an arrangement in which the protrusions 50 overlap the center of the unit region 11. When multiple protrusions 50 are arranged so as not to overlap the center of the unit region 11, they may include protrusions 50 (referred to as "first protrusions") that straddle the outer edge of the unit region 11 in a plan view. As illustrated in Figure 4A, when the unit region 11 is roughly rectangular in a plan view, one or more first protrusions may straddle each side of the unit region 11 in a plan view. Furthermore, a mixture of first protrusions straddling one outer edge of the unit region 11 and first protrusions straddling two or more outer edges of the unit region 11 may be present. In addition, a mixture of first protrusions and protrusions 50 (referred to as "second protrusions") that do not straddle the outer edge of the unit region 11 in a plan view may be present.

[0109] [Regarding the materials for the fasteners] Similar vibration simulations were performed using a resin material for the fixing device 60, and the magnitude and maximum amplitude position were compared for the case where the fixing device 60 is made of iron, the case where the fixing device 60 is made of resin, and the case where the fixing device 60 is not provided. The Young's modulus, Poisson's ratio, and density of the fixing device 60 made of resin material are shown in Table 7.

[0110] [Table 7]

[0111] The comparison results are shown in Table 8. From Table 8, it can be seen that the magnitude amplification effect when the fixing device 60 is made of iron compared to when the fixing device 60 is not provided was at most about 3%. On the other hand, it was also found that there were conditions in which the magnitude was higher when the fixing device 60 was not provided. Furthermore, the position of the maximum amplitude showed almost the same trend in both cases.

[0112] [Table 8]

[0113] [The second electrode layer has a configuration that includes multiple unit electrodes.] In the explanation so far, we have given an example in which the second electrode layer 30 is a common electrode that is not divided into multiple electrodes, but the configuration of the second electrode layer 30 is not limited to such an example.

[0114] Further embodiments of the tactile presentation element 1B according to the present invention will be described with reference to Figures 15, 16, and 17. Figures 15 and 16 are schematic cross-sectional and exploded perspective views of the tactile presentation element 1B, respectively. Figure 17 is a schematic plan view of the tactile presentation element 1B, with the first substrate 40 and the projection 50 omitted from the illustration.

[0115] In the tactile presentation element 1B shown in Figures 15, 16, and 17, the first electrode layer 20 includes a plurality of electrically independent electrodes 22, and the second electrode layer 30 also includes a plurality of electrically independent electrodes 32. Each of the plurality of electrodes 22 in the first electrode layer 20 is strip-shaped and extends along a certain direction. Each of the plurality of electrodes 32 in the second electrode layer 30 is strip-shaped and extends along a direction that intersects (for example, perpendicular to) the direction in which the electrodes 22 of the first electrode layer 20 extend. Hereinafter, each electrode 22 of the first electrode layer 20 will be referred to as the "first strip electrode," and each electrode 32 of the second electrode layer 30 will be referred to as the "second strip electrode."

[0116] In the tactile feedback element 1B, the region where the first strip electrode 22 and the second strip electrode 32 intersect becomes the unit region 11. In addition, in the tactile feedback element 1B, the piezoelectric layer 10 is divided into multiple parts (hereinafter referred to as "unit parts") 11P that are spaced apart from each other. Each of the multiple unit parts 11P is located in the intersection region of the first strip electrode 22 and the second strip electrode 32 (i.e., the unit region 11).

[0117] A tactile feedback element 1B was prototyped according to the specifications shown in Table 9, and the tactile feedback it provided was verified.

[0118] [Table 9]

[0119] As shown in Table 9, the length L1 of one side of the tactile presentation element 1B in a plan view was 7.0 mm. The piezoelectric layer 10 was formed from PZT with a thickness of 0.19 mm. The first electrode layer 20, containing five first strip electrodes 22, was formed from copper (Cu) with a thickness of 100 nm. The width W1 of each first strip electrode 22 was 0.8 mm, and the spacing S2 between adjacent first strip electrodes 22 was 0.2 mm. The second electrode layer 30, containing five second strip electrodes 32, was formed from copper (Cu) with a thickness of 100 nm. The width W2 of each second strip electrode 32 was 0.8 mm, and the spacing S3 between adjacent second strip electrodes 32 was 0.2 mm. The area of ​​the intersection region between the first strip electrodes 22 and the second strip electrodes 32 was 0.64 mm². 2 Therefore, the area of ​​each unit portion 11 of the piezoelectric layer 10 is also 0.64 mm². 2 That is the case.

[0120] A first substrate 40 was formed from polyimide with a thickness of 50 μm. The first substrate 40, on which the first electrode layer 20 was formed, was attached to the piezoelectric layer 10 with an adhesive. A second substrate 70 was formed from polyimide with a thickness of 50 μm. The second substrate 70, on which the second electrode layer 30 was formed, was attached to the piezoelectric layer 10 with an adhesive.

[0121] Multiple cylindrical protrusions 50 were formed from polyethylene, with each protrusion 50 having a height H of 3.0 mm and a diameter D1 of 0.5 mm. A fixing device 60 was formed from acrylic resin. The thickness T1 of the bottom 61 of the fixing device 60 was 1.0 mm, and the height H1 of the side wall 62 was 2.0 mm (i.e., the overall height H2 of the fixing device 60 was 3.0 mm). The fixing device 60 was joined to the outer periphery of the second substrate 70.

[0122] A predetermined signal was output to each of the first strip electrodes 22 and second strip electrodes 32 of the prototype haptic presentation element 1B to generate vibration. The refresh rate was set to 200 Hz and the gate open time to 0.2 ms.

[0123] When the tactile sensation presented was evaluated with a finger F in contact with the top surface of the protrusion 50 of the prototype tactile presentation element 1B, it was possible to obtain a sensation as if the material were different by varying the output signal. Furthermore, it felt as if the vibration source was present on the surface of finger F. In addition, compared to the case where the same signal was output with the comparative example tactile presentation element 901, it felt smoother and the tactile sensation was more refined. In other words, the vibration was felt over a narrower area than with the comparative example tactile presentation element 901.

[0124] Thus, like the tactile presentation element 1, the tactile presentation element 1B can accurately present tactile sensations in minute areas. In the tactile presentation element 1B, the piezoelectric layer 10 is divided into multiple unit parts 11P, so the propagation of vibrations between the unit parts 11P is suppressed. This makes it possible to further increase the precision of tactile sensations.

[0125] In addition, a configuration in which the second electrode layer 30 includes multiple electrodes and the first electrode layer 20 includes only a single common electrode may be adopted, unlike the configurations exemplified above.

[0126] [Examples of vibrating layers other than piezoelectric layers] Further embodiments of the tactile presentation element 1C according to the present invention will be described with reference to Figures 18 and 19. Figure 18 is a schematic exploded perspective view showing the tactile presentation element 1C. Figure 19 is a schematic cross-sectional view showing a part of the tactile presentation element 1C.

[0127] The vibrating layer 10A of the tactile presentation element 1C shown in Figures 18 and 19 includes a plurality of induction coils 13. Each induction coil 13 is positioned in the region where the first strip electrode 22 and the second strip electrode 32 intersect. In other words, the vibrating layer 10A includes an induction coil 13 for each of the plurality of unit regions 11.

[0128] Furthermore, in the tactile presentation element 1C, a permanent magnet 80 is placed on the back side of the second substrate 70 (the side opposite to the second electrode layer 30 relative to the second substrate 70) instead of a fixing device 60. The permanent magnet 80 is, for example, a neodymium magnet.

[0129] Figure 20 is a perspective view showing an example of an induction coil 13. In the examples shown in Figures 19 and 20, the induction coil 13 includes a first coil layer 13a, a second coil layer 13b, a first contact portion 13c, a second contact portion 13d, and a third contact portion 13e.

[0130] The first coil layer 13a and the second coil layer 13b are stacked in the thickness direction of the vibrating body layer 10A. With respect to the center of the vibrating body layer 10A in the thickness direction, the first coil layer 13a is positioned on the first electrode layer 20 side, and the second coil layer 13b is positioned on the second electrode layer 30 side. Although this example shows the induction coil 13 containing two coil layers (first coil layer 13a and second coil layer 13b), the number of coil layers is not limited to two.

[0131] The first coil layer 13a is composed of a first conductor cw1 that extends in a spiral shape. There is no particular restriction on the number of turns of the first conductor cw1. A first insulating layer 14 is provided between the first coil layer 13a and the first electrode layer 20. The first coil layer 13a is electrically connected to the corresponding first strip electrode 22 via a first contact portion 13c that extends from one end of the first conductor cw1 toward the first electrode layer 20.

[0132] The second coil layer 13b is composed of a second conductor cw2 that extends in a spiral shape. There is no particular restriction on the number of turns of the second conductor cw2. A second insulating layer 15 is provided between the second coil layer 13b and the second electrode layer 30. The second coil layer 13b is electrically connected to the corresponding second strip electrode 32 via a second contact portion 13d that extends from one end of the second conductor cw2 toward the second electrode layer 30.

[0133] A third insulating layer 16 is provided between the first coil layer 13a and the second coil layer 13b. The first coil layer 13a and the second coil layer 13b are electrically connected via a third contact portion 13e that extends from the other end of the first conductor cw1 to the other end of the second conductor cw2.

[0134] When an electric current is applied to the induction coil 13, an electromagnetic force is generated. The attractive and repulsive forces between the induction coil 13 and the permanent magnet 80 cause deformation in each unit region 11 of the vibrating body layer 10A, thereby generating vibration.

[0135] A tactile feedback element 1C was prototyped according to the specifications shown in Table 10, and the tactile feedback it provided was verified.

[0136] [Table 10]

[0137] As shown in Table 10, the length L1 of one side of the tactile presentation element 1C in plan view was set to 7.0 mm. The first electrode layer 20 including five first strip electrodes 22 was formed of copper (Cu), and its thickness was set to 100 nm. The width W1 of each first strip electrode 22 was set to 0.8 mm, and the interval S2 between adjacent first strip electrodes 22 was set to 0.2 mm. The second electrode layer 30 including five second strip electrodes 32 was formed of copper (Cu), and its thickness was set to 100 nm. The width W2 of each second strip electrode 32 was set to 0.8 mm, and the interval S3 between adjacent second strip electrodes 32 was set to 0.2 mm. The area of the intersection region between the first strip electrode 22 and the second strip electrode 32 was 0.64 mm 2 is.

[0138] The number of stacked coil layers of each induction coil 13 was set to 2. The width and thickness of the conducting wire constituting each coil layer were set to 25 μm and 200 nm, respectively. The number of turns of the conducting wire in each coil layer was set to 10.

[0139] The first substrate 40 was formed of polyimide, and its thickness was set to 50 μm. The second substrate 70 was formed of polyimide, and its thickness was set to 50 μm. The first substrate 40 on which the first electrode layer 20 was formed and the second substrate 70 on which the second electrode layer 30 was formed were joined by an adhesive so as to sandwich the vibrating body layer 10A including a plurality of induction coils 13.

[0140] A plurality of columnar protrusions 50 were formed of polyethylene. The height H of each protrusion 50 was set to 3.0 mm, and the diameter D1 was set to 0.5 mm. A neodymium magnet was used as the permanent magnet 80.

[0141] A predetermined signal was output to each first strip electrode 22 and each second strip electrode 32 of the prototype tactile presentation element 1C to generate vibration. The voltage of the signal wave was set to 1000 Vpp, the refresh rate was set to 200 Hz, and the gate open time was set to 0.2 ms.

[0142] When the tactile sensation presented was evaluated with a finger F in contact with the top surface of the protrusion 50 of the prototype haptic presentation element 1C, a clear tactile sensation was felt on the surface of the finger. Furthermore, similar to haptic presentation element 1, the tactile sensation had a high degree of detail.

[0143] Thus, a tactile presentation element 1C equipped with a vibrating body layer 10A including an induction coil 13 can accurately present tactile sensations to minute areas, similar to a tactile presentation element 1 equipped with a vibrating body layer (piezoelectric layer) 10 formed from a piezoelectric material.

[0144] Furthermore, if a piezoelectric layer 10 is used as the vibrating layer, tactile sensing can be performed by detecting changes in the resistance value of the piezoelectric layer 10. Even in this case, the provision of multiple protrusions 50 provides the effect of increasing the resolution of the sensing.

[0145] When the portion of the tactile presentation element 1C excluding the protrusion 50 and the permanent magnet 80 is referred to as a "coil matrix element," the tactile presentation element 1C may also include an additional coil matrix element in place of the permanent magnet 80. Figure 21 shows a tactile presentation element 1C employing such a configuration.

[0146] In the example shown in Figure 21, the tactile presentation element 1C comprises a first coil matrix element CD1 and a second coil matrix element CD2.

[0147] The first coil matrix element CD1 includes a vibrating body layer 10A, a first electrode layer 20, a second electrode layer 30, a first substrate 40, and a second substrate 70, and is the part shown in the examples in Figures 18 and 19, excluding the protrusion 50 and the permanent magnet 80.

[0148] The second coil matrix element CD2 has a structure that is the inverted version of the first coil matrix element CD1, and includes a coil matrix layer 90, a third electrode layer 100, a fourth electrode layer 110, a third substrate 120, and a fourth substrate 130.

[0149] The coil matrix layer 90 includes a plurality of induction coils 93. The coil matrix layer 90 has a plurality of regions in which the generation of electromagnetic force can be controlled independently of each other, and induction coils 93 are arranged in each of these regions.

[0150] The third electrode layer 100 and the fourth electrode layer 110 are arranged to face each other via the coil matrix layer 90. The third electrode layer 100 is located on the front side (first coil matrix element CD1 side) of the coil matrix layer 90, and the fourth electrode layer 110 is located on the back side of the coil matrix layer 90.

[0151] The third electrode layer 100 includes a plurality of third strip electrodes 102 extending along a certain direction. The fourth electrode layer 110 includes a plurality of fourth strip electrodes 112 extending in a direction intersecting (e.g., perpendicular to) the direction in which the third strip electrodes 102 extend.

[0152] Each induction coil 93 is positioned in the region where the third strip electrode 102 and the fourth strip electrode 112 intersect. Similar to the induction coil 13 of the first coil matrix element CD1, the induction coil 93 includes a first coil layer 93a, a second coil layer 93b, a first contact portion 93c, a second contact portion 93d, and a third contact portion 93e.

[0153] The first coil layer 93a and the second coil layer 93b are stacked in the thickness direction of the coil matrix layer 90. The first coil layer 93a is located on the front side of the second coil layer 93b.

[0154] A fourth insulating layer 94 is provided between the first coil layer 93a and the third electrode layer 100. The first coil layer 93a is electrically connected to the corresponding third strip electrode 92 via a first contact portion 93c.

[0155] A fifth insulating layer 95 is provided between the second coil layer 93b and the fourth electrode layer 110. The second coil layer 93b is electrically connected to the corresponding fourth strip electrode 112 via a second contact portion 93d.

[0156] A sixth insulating layer 96 is provided between the first coil layer 93a and the second coil layer 93b. The first coil layer 93a and the second coil layer 93b are electrically connected via a third contact portion 93e.

[0157] In the example shown in Figure 21, the attractive and repulsive forces between the induction coil 13 of the first coil matrix element CD1 and the induction coil 93 of the second coil matrix element CD2 cause deformation in each unit region 11 of the vibrating body layer 10A, thereby generating vibration.

[0158] In configurations equipped with a permanent magnet 80, as shown in the examples in Figures 18 and 19, it can be difficult to bend the tactile presentation element 1C. However, in configurations equipped with a pair of coil matrix elements (first coil matrix element CD1 and second coil matrix element CD2), as shown in the example in Figure 21, it becomes easy to bend the tactile presentation element 1C. [Industrial applicability]

[0159] Embodiments of the present invention can be widely used in tactile presentation devices that present tactile sensations through vibrational stimulation. [Explanation of symbols]

[0160] 1, 1A, 1B, 1C Tactile feedback elements 2 Control device 10. Vibrating layer (piezoelectric layer) 10a First main surface 10b Second main surface 10A Vibration layer 11 Unit Areas 11P Unit Section 12 Vibration area 13.93 Induction coil 13a, 93a First coil layer 13b, 93b Second coil layer 13c, 93c First contact section 13d, 93d Second contact area 13e, 93e Third Contact Section 14. First insulating layer 15. Second insulating layer 16. Third insulating layer 20 1st electrode layer 21 Unit electrodes 22 First strip electrode 30 Second electrode layer 30a First region of the common electrode 30b Second region of the common electrode 32. Second strip electrode 40 First board 50 protrusions 60 Fixtures 61 Bottom 62 Side wall section 70 Second board 70a First region of the second substrate 70b Second region of the second substrate 80 Permanent Magnets 90 Coil Matrix Layers 94. Fourth insulating layer 95 Fifth insulating layer 96. Sixth insulating layer 100 3rd electrode layer 102 Third strip electrode 110 4th electrode layer 120 Third board 130 Fourth substrate 100 Tactile presentation devices 210 Personal Computers (PCs) 220 Head-Mounted Displays (HMDs) GL gate wiring SL Source Wiring Tr Transistor cw1 1st conductor cw2 2nd conductor CD1 First Coil Matrix Element CD2 Second Coil Matrix Element

Claims

1. Vibrating layer and A first electrode layer and a second electrode layer are arranged to face each other via the vibrating body layer, A tactile presentation element comprising, At least one of the first electrode layer and the second electrode layer includes a plurality of electrodes that are electrically independent of each other. The vibrating layer includes a plurality of unit regions in which the generation of vibrations can be controlled independently of each other. The first electrode layer further comprises a plurality of protrusions arranged on the opposite side from the vibrating body layer, The plurality of protrusions are tactile presentation elements that do not overlap the centers of each of the plurality of unit regions in a plan view.

2. A vibrating body layer, A first electrode layer and a second electrode layer are arranged to face each other via the vibrating body layer, A tactile presentation element comprising, At least one of the first electrode layer and the second electrode layer includes a plurality of electrodes that are electrically independent of each other. The vibrating layer includes a plurality of unit regions in which the generation of vibrations can be controlled independently of each other. The first electrode layer further comprises a plurality of protrusions arranged on the opposite side from the vibrating body layer, A tactile presentation element in which the plurality of protrusions include at least one first protrusion arranged to straddle the outer edge of at least one of the plurality of unit regions in a plan view.

3. The at least one first projection is a plurality of first projections, Each of the aforementioned plurality of unit regions is substantially rectangular in plan view, The tactile presentation element according to claim 2, wherein one or more of the plurality of first protrusions straddle each side of the plurality of unit regions in a plan view.

4. The tactile presentation element according to claim 1 or 2, further comprising a first substrate disposed between the first electrode layer and the plurality of protrusions and supporting the first electrode layer.

5. The second electrode layer is further disposed on the opposite side from the vibrating body layer to the second electrode layer and comprises a second substrate that supports the second electrode layer. The tactile presentation element according to claim 1 or 2, wherein the thickness h [mm] of the second substrate and the Young's modulus E [GPa] of the second substrate satisfy the relationship E・h ≤ 1.

95.

6. Each of the aforementioned plurality of unit regions is substantially rectangular in plan view, The tactile presentation element according to claim 1 or 2, wherein the height of each of the plurality of protrusions is at least twice the length of the shortest side among the plurality of sides of each unit region in a plan view.

7. Each of the aforementioned plurality of unit regions is substantially rectangular in plan view, The tactile presentation element according to claim 1 or 2, wherein the height of each of the plurality of protrusions is three times or more the length of the shortest side among the plurality of sides of each unit region in a plan view.

8. Each of the aforementioned multiple protrusions has substantially the same cross-sectional shape along the height direction of each protrusion. The cross-sectional area A and height H of each of the aforementioned multiple protrusions are such that H ≥ (2・A ０．５ A tactile presentation element according to claim 1 or 2, satisfying the relationship ) / π.

9. The tactile presentation element according to claim 8, wherein the shape of the cross-section of each of the plurality of protrusions is substantially circular, substantially elliptical, substantially rectangular, substantially equilateral triangle, or substantially regular convex polygon.

10. The tactile presentation element according to claim 1 or 2, wherein the Young's modulus of each of the plurality of protrusions is 20 GPa or less.

11. The tactile presentation element according to claim 1 or 2, wherein each of the plurality of electrodes is a plurality of unit electrodes corresponding to each of the plurality of unit regions.

12. The tactile presentation element according to claim 11, wherein the plurality of unit electrodes are nine or more unit electrodes arranged in an m x n (where m and n are integers of 3 or more) configuration.

13. A vibrating layer and A first electrode layer and a second electrode layer are arranged to face each other via the vibrating body layer, A tactile presentation element comprising, At least one of the first electrode layer and the second electrode layer includes a plurality of electrodes that are electrically independent of each other. The vibrating layer includes a plurality of unit regions in which the generation of vibrations can be controlled independently of each other. The first electrode layer further comprises a plurality of protrusions arranged on the opposite side from the vibrating body layer, Each of the first electrode layer and the second electrode layer includes the plurality of electrodes, The plurality of electrodes included in the first electrode layer are a plurality of first strip electrodes extending along a predetermined direction, A tactile presentation element in which the plurality of electrodes included in the second electrode layer are a plurality of second strip electrodes extending along a direction intersecting the predetermined direction.

14. A vibrating layer and A first electrode layer and a second electrode layer are arranged to face each other via the vibrating body layer, A tactile presentation element comprising, At least one of the first electrode layer and the second electrode layer includes a plurality of electrodes that are electrically independent of each other. The vibrating layer includes a plurality of unit regions in which the generation of vibrations can be controlled independently of each other. The first electrode layer further comprises a plurality of protrusions arranged on the opposite side from the vibrating body layer, A second substrate, which is positioned on the opposite side of the vibrating body layer from the second electrode layer and supports the second electrode layer, having a first region that overlaps in a plan view with the region encompassing the plurality of unit regions of the vibrating body layer, and a second region that is located outside the first region in a plan view, A fixing device that is bonded to the second region of the second substrate and fixes the second region, A haptic presentation element that further enhances this feature.

15. A vibrating layer and A first electrode layer and a second electrode layer are arranged to face each other via the vibrating body layer, A tactile presentation element comprising, At least one of the first electrode layer and the second electrode layer includes a plurality of electrodes that are electrically independent of each other. The vibrating layer includes a plurality of unit regions in which the generation of vibrations can be controlled independently of each other. The first electrode layer further comprises a plurality of protrusions arranged on the opposite side from the vibrating body layer, Each of the aforementioned plurality of electrodes is a plurality of unit electrodes corresponding to each of the plurality of unit regions, The first electrode layer includes the plurality of unit electrodes, The second electrode layer contains only a single common electrode. The common electrode has a first region that overlaps in a plan view with the region encompassing the plurality of unit regions of the vibrating body layer, and a second region that is located outside the first region in a plan view. A tactile presentation element further comprising a fixing device that is joined to the second region of the common electrode and fixes the second region.

16. The tactile presentation element according to claim 1 or 2, wherein the vibrating layer is a piezoelectric layer formed from a piezoelectric material.

17. The tactile presentation element according to claim 16, wherein the piezoelectric layer includes a plurality of portions that are separated from each other.

18. A vibrating layer and A first electrode layer and a second electrode layer are arranged to face each other via the vibrating body layer, A tactile presentation element comprising, At least one of the first electrode layer and the second electrode layer includes a plurality of electrodes that are electrically independent of each other. The vibrating layer includes a plurality of unit regions in which the generation of vibrations can be controlled independently of each other. The first electrode layer further comprises a plurality of protrusions arranged on the opposite side from the vibrating body layer, The vibrating layer is a tactile presentation element that includes an induction coil in each of the plurality of unit regions.

19. A tactile presentation element according to claim 1 or 2, A control device for controlling the tactile presentation element, A tactile presentation device equipped with the following features.

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