Input device, input system, and method for driving the input device

Abstract

To provide an input device with excellent operability using a haptic technology, an input system, and a method for driving the input device.SOLUTION: An input device according to the present invention comprises a housing and a piezoelectric actuator. The piezoelectric actuator comprises: a piezoelectric body layer which is mounted on the housing and composed of a piezoelectric material; a positive internal electrode installed in the piezoelectric body layer; and a negative internal electrode which is installed in the piezoelectric body layer and faces the positive internal electrode with the piezoelectric body layer therebetween. When a voltage is applied between the positive internal electrode and the negative internal electrode, the piezoelectric actuator expands or contracts in a direction perpendicular to electrode planes of the positive internal electrode and the negative internal electrode.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an input device, an input system, and a driving method of an input device for tactile presentation by vibration.

Background Art

[0002] Various actuators are used in tactile function devices that present tactile sensations to users. For example, electromagnetic actuators such as eccentric motors and linear resonant actuators are used for notification functions. In addition to these electromagnetic actuators, piezoelectric actuators are also used for force feedback functions.

[0003] In recent years, tactile technology has been advancing, and technologies have been developed that can reproduce tactile expressions such as a rough feeling and a smooth feeling in addition to the notification function (see, for example, Patent Document 1). Furthermore, in the liquid crystal panel of a mobile device, a different tactile surface is required for each region.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] A stylus pen may be used for input to a mobile device. When using a stylus pen, it becomes easy to draw characters and figures, but when drawing with a stylus pen, the operating feeling is different from that of an actual writing tool, and the user may feel discomfort. Therefore, the present inventors have considered improving the operating feeling of a stylus pen by using tactile technology.

[0006] In view of the above circumstances, an object of the present invention is to provide an input device, an input system, and a driving method of an input device that are excellent in operating feeling using tactile technology. [Means for solving the problem]

[0007] To achieve the above objective, an input device according to one embodiment of the present invention comprises a housing and a piezoelectric actuator. The above-described housing has a pen-like shape with the first direction as the longitudinal direction, comprising a pen tip portion, a pen shaft portion, and a grip portion located between the pen tip portion and the pen shaft portion, which is grasped by the user's fingers. The piezoelectric actuator is mounted on the housing and comprises a piezoelectric layer made of piezoelectric material, a positive electrode internal electrode provided in the piezoelectric layer, and a negative electrode internal electrode provided in the piezoelectric layer and facing the positive electrode internal electrode via the piezoelectric layer. When a voltage is applied between the positive electrode internal electrode and the negative electrode internal electrode, the actuator expands and contracts along a direction perpendicular to the electrode surfaces of the positive electrode internal electrode and the negative electrode internal electrode. The piezoelectric actuator is mounted on the grip portion in such a orientation that the direction perpendicular to the electrode surface is perpendicular to the first direction, and vibrates in a direction perpendicular to the first direction.

[0010] The above housing has a recess provided in the grip portion, The piezoelectric actuator may be housed in the recess and sealed with a sealing material.

[0011] The above piezoelectric actuator consists of multiple piezoelectric actuator chips, Piezoelectric The actuator chips may be stacked with a stacking direction perpendicular to the first direction described above.

[0012] The above housing has a predetermined resonant frequency, The device may further include a drive unit that supplies a drive signal to the positive and negative internal electrodes, having a waveform obtained by amplitude-modulating a sine wave whose frequency is the above-mentioned resonant frequency with the above-mentioned modulated signal wave, which is used as the modulated wave.

[0013] The above resonant frequency may be between 20 kHz and 110 kHz.

[0014] To achieve the above objective, an input device according to one embodiment of the present invention comprises a housing and a piezoelectric actuator. The above enclosure is 、 The first direction is the longitudinal direction It has a pen-like shape, comprising a pen shaft portion that the user's hand grips, and a pen tip portion connected to the pen shaft portion. The piezoelectric actuator is mounted on the housing and comprises a piezoelectric layer made of piezoelectric material, a positive electrode internal electrode provided in the piezoelectric layer, and a negative electrode internal electrode provided in the piezoelectric layer and facing the positive electrode internal electrode via the piezoelectric layer. When a voltage is applied between the positive electrode internal electrode and the negative electrode internal electrode, the actuator expands and contracts along a direction perpendicular to the electrode surfaces of the positive electrode internal electrode and the negative electrode internal electrode. The piezoelectric actuator is oriented such that the direction perpendicular to the electrode surface is parallel to the first direction. It is mounted on the pen tip portion, separate from the pen shaft portion, and vibrates in a direction parallel to the first direction.

[0015] The pen tip portion may include a connecting portion made of metal or resin that connects the pen shaft portion and the piezoelectric actuator.

[0016] The tip portion of the pen may protrude from the piezoelectric actuator along the first direction and have a tip made of metal.

[0017] The piezoelectric actuator may be composed of a plurality of piezoelectric actuator chips, and the plurality of Piezoelectric actuator chips may be laminated with the first direction as the lamination direction.

[0018] The housing has a predetermined resonance frequency, and may further include a driving unit that supplies a driving signal having a waveform obtained by amplitude-modulating a sine wave having the resonance frequency with a signal wave having a frequency of 50 Hz or more and 350 Hz or less as a modulation wave to the positive electrode internal electrode and the negative electrode internal electrode.

[0019] The resonance frequency may be 20 kHz or more and 110 kHz or less.

[0020] The housing has a predetermined resonance frequency, and may further include a driving unit that supplies a driving signal having a waveform obtained by amplitude-modulating a sine wave having a frequency of 150 Hz or more and 250 Hz or less with a signal wave having a frequency of 2 Hz or more and 50 Hz or less as a modulation wave to the positive electrode internal electrode and the negative electrode internal electrode.

[0021] Each piezoelectric actuator chip includes a plurality of blocks each including a predetermined number of the positive electrode internal electrodes and the negative electrode internal electrodes, and a relaxation layer is provided between the plurality of blocks. The relaxation layer may be a piezoelectric layer that is thicker than the piezoelectric layer between the positive electrode internal electrode and the negative electrode internal electrode within the block.

[0022] To achieve the above object, an input system according to an aspect of the present invention includes an input device and a driving unit. The input device is The first direction is the longitudinal direction, and the pen has a pen tip portion, a pen shaft portion, and a grip portion located between the pen tip portion and the pen shaft portion, which is held by the user's fingers. composed of a housing, a piezoelectric layer made of a piezoelectric material mounted on the housing, a positive internal electrode provided in the piezoelectric layer, and a negative internal electrode provided in the piezoelectric layer and facing the positive internal electrode through the piezoelectric layer. When a voltage is applied between the positive internal electrode and the negative internal electrode, a piezoelectric actuator that expands and contracts along a direction perpendicular to the electrode surfaces of the positive internal electrode and the negative internal electrode is provided. The piezoelectric actuator is mounted on the grip portion in such a orientation that the direction perpendicular to the electrode surface is perpendicular to the first direction, and vibrates in a direction perpendicular to the first direction. The driving unit supplies a driving signal to the positive internal electrode and the negative internal electrode. Furthermore, in order to achieve the above objective, an input system according to one embodiment of the present invention comprises an input device and a drive unit. The input device comprises a pen-shaped housing with the first direction as its longitudinal direction, having a pen shaft portion that is grasped by the user's hand and a pen tip portion connected to the pen shaft portion; a piezoelectric layer made of piezoelectric material mounted on the housing, a positive electrode internal electrode provided in the piezoelectric layer, and a negative electrode internal electrode provided in the piezoelectric layer and facing the positive electrode internal electrode via the piezoelectric layer; and a piezoelectric actuator that expands and contracts along a direction perpendicular to the electrode surfaces of the positive electrode internal electrode and the negative electrode internal electrode when a voltage is applied between the positive electrode internal electrode and the negative electrode internal electrode, and the piezoelectric actuator is mounted on the pen tip portion away from the pen shaft portion in a direction parallel to the first direction, with the direction perpendicular to the electrode surfaces being parallel to the first direction, and vibrates in a direction parallel to the first direction. The drive unit supplies drive signals to the positive electrode and the negative electrode.

[0023] To achieve the above object, a driving method for an input device according to an aspect of the present invention is The first direction is the longitudinal direction, and the pen has a pen tip portion, a pen shaft portion, and a grip portion located between the pen tip portion and the pen shaft portion, which is held by the user's fingers. composed of a housing, a piezoelectric layer made of a piezoelectric material mounted on the housing, a positive internal electrode provided in the piezoelectric layer, and a negative internal electrode provided in the piezoelectric layer and facing the positive internal electrode through the piezoelectric layer. When a voltage is applied between the positive internal electrode and the negative internal electrode, it expands and contracts along a direction perpendicular to the electrode surfaces of the positive internal electrode and the negative internal electrode The grip portion is mounted such that the direction perpendicular to the electrode surface is perpendicular to the first direction, and it vibrates in a direction perpendicular to the first direction. A driving signal is supplied to the positive internal electrode and the negative internal electrode of the piezoelectric actuator. Furthermore, in order to achieve the above objective, a driving method for an input device according to one embodiment of the present invention provides a driving signal to the positive and negative electrodes of a piezoelectric actuator, which is mounted on a pen-shaped housing having a pen shaft portion that is grasped by the user's hand and a pen tip portion connected to the pen shaft portion, with the first direction being the longitudinal direction, and comprising a piezoelectric layer made of piezoelectric material, a positive electrode internal electrode provided in the piezoelectric layer, and a negative electrode internal electrode provided in the piezoelectric layer and facing the positive electrode internal electrode via the piezoelectric layer, wherein when a voltage is applied between the positive electrode internal electrode and the negative electrode internal electrode, a driving signal is supplied to the positive electrode internal electrode and the negative electrode internal electrode of a piezoelectric actuator, which expands and contracts along a direction perpendicular to the electrode surfaces of the positive electrode internal electrode and the negative electrode internal electrode, and is mounted on the pen tip portion away from the pen shaft portion in a direction parallel to the first direction, with the direction perpendicular to the electrode surfaces being parallel to the first direction.

Advantages of the Invention

[0024] As described above, according to the present invention, it is possible to provide an input device, an input system, and a driving method for an input device that are excellent in operation feeling using tactile technology.

Brief Description of the Drawings

[0025] [Figure 1] It is a plan view of an input device according to a first embodiment of the present invention. [Figure 2]This is a cross-sectional view of the input device described above. [Figure 3] This is an enlarged cross-sectional view of the input device shown above. [Figure 4] This is a plan view of the grip portion of the input device described above. [Figure 5] This is a cross-sectional view of the grip portion of the input device described above. [Figure 6] This is a cross-sectional view of the grip portion of the input device described above. [Figure 7] This is a cross-sectional view showing a piezoelectric actuator housed in a recess in the grip portion of the input device described above. [Figure 8] This is a cross-sectional view of a piezoelectric actuator chip that constitutes the piezoelectric actuator provided in the above-mentioned input device. [Figure 9] This is a schematic diagram showing the thickness of the piezoelectric layer in the piezoelectric actuator chip described above. [Figure 10] This is a schematic diagram showing the vibration of the piezoelectric actuator chip described above. [Figure 11] This is a schematic diagram showing the vibration of the piezoelectric actuator chip housed in the recess described above. [Figure 12] This is a schematic diagram of the piezoelectric actuator chip housed in the recess shown above. [Figure 13] This is a schematic diagram illustrating the operation of the input device described above. [Figure 14] This is the amplitude-modulated wave waveform generated by the drive unit of the input device described above. [Figure 15] This is an enlarged waveform of the amplitude-modulated wave shown in Figure 14. [Figure 16] This is the amplitude-modulated waveform (voltage waveform only) generated by the drive unit of the input device described above. [Figure 17] This is an enlarged waveform of the amplitude-modulated wave shown in Figure 16. [Figure 18] This is a schematic diagram showing the amplitude of an amplitude-modulated wave. [Figure 19] This is a plan view of an input device according to a second embodiment of the present invention. [Figure 20] This is an enlarged plan view of the input device shown above. [Figure 21]This is a schematic diagram showing the vibration of the piezoelectric actuator chip that constitutes the piezoelectric actuator provided in the above input device. [Figure 22] This is a schematic diagram illustrating the operation of the input device described above. [Figure 23] This is an example of an amplitude-modulated wave waveform generated by the drive unit of the above input device. [Figure 24] This is an example of an amplitude-modulated wave waveform generated by the drive unit of the above input device. [Modes for carrying out the invention]

[0026] (First Embodiment) An input device according to the first embodiment of the present invention will be described.

[0027] [Input device configuration] Figure 1 is a plan view of the input device 100 according to this embodiment. Figure 2 is a cross-sectional view of the input device 100, taken along line AA in Figure 1. Figure 3 is a partially enlarged view of Figure 2. As shown in these figures, the input device 100 is a stylus pen type input device and comprises a housing 110, a support plate 120, and a piezoelectric actuator 130.

[0028] The housing 110 has a pen-like shape as shown in Figure 1. Hereinafter, the longitudinal direction of the housing 110 will be referred to as the X direction, one direction perpendicular to the X direction will be referred to as the Y direction, and the direction perpendicular to both the X and Z directions will be referred to as the Z direction. As shown in Figure 1, the housing 110 comprises a pen tip portion 111, a pen shaft portion 112, and a grip portion 113.

[0029] The pen tip portion 111 is the part that constitutes the pen tip of the pen-shaped housing 110. As shown in Figure 3, the pen tip portion 111 has a joint portion 111a and a tip portion 111b. The joint portion 111a is a screw hole provided at the end of the pen tip portion 111 on the grip portion 113 side and is used for joining with the grip portion 113. The tip portion 111b is provided at the end of the pen tip portion 111 opposite to the grip portion 113 and is formed in a pointed shape. The pen tip portion 111 is made of a resin such as polycarbonate or a metal such as stainless steel.

[0030] The pen shaft portion 112 is the part that constitutes the pen shaft of the pen-shaped housing 110. As shown in Figure 3, the pen shaft portion 112 has a joint portion 112a. The joint portion 112a is a screw hole provided at the end of the pen shaft portion 112 on the grip portion 113 side, and is used for joining with the grip portion 113. The pen shaft portion 112 is made of a resin such as polycarbonate or a metal such as stainless steel.

[0031] The grip portion 113 is positioned between the pen tip portion 111 and the pen shaft portion 112, and constitutes the grip of the pen-shaped housing 110. Figure 4 is a plan view of the grip portion 113. Figures 5 and 6 are cross-sectional views of the grip portion 113, with Figure 5 being a cross-sectional view along line BB in Figure 4, and Figure 6 being a cross-sectional view along line CC in Figure 4. As shown in these figures, the grip portion 113 has a joint portion 113a, a joint portion 113b, and a recess 113c. The joint portion 113a is provided at the end of the grip portion 113 on the pen tip portion 111 side and is a screw that screws into the joint portion 111a of the pen tip portion 111. The joint portion 113b is provided at the end of the grip portion 113 on the pen shaft portion 112 side and is a screw that screws into the joint portion 112a of the pen shaft portion 112.

[0032] As shown in Figure 3, the support plate 120 is positioned at the bottom of the recess 113c and supports the piezoelectric actuator 130. The support plate 120 is made of a metal such as stainless steel.

[0033] The piezoelectric actuator 130 generates vibrations, causing tactile sensations in the input device 100. Figure 7 is a cross-sectional view showing the piezoelectric actuator 130 located on the grip portion 113. As shown in the figure, the piezoelectric actuator 130 is mounted on the support plate 120 and housed in the recess 113c. The piezoelectric actuator 130 is also fixed in the recess 113c by a sealing material (not shown). The sealing material is, for example, epoxy resin.

[0034] As shown in Figure 7, the piezoelectric actuator 130 is constructed by stacking two piezoelectric actuator chips: a first piezoelectric actuator chip 131 and a second piezoelectric actuator chip 132. The first piezoelectric actuator chip 131 and the second piezoelectric actuator chip 132 can be piezoelectric actuator chips having the same structure. Figure 8 is a schematic diagram of a piezoelectric actuator chip 140 that can constitute the first piezoelectric actuator chip 131 and the second piezoelectric actuator chip 132.

[0035] As shown in the figure, the piezoelectric actuator chip 140 comprises a piezoelectric layer 141, a positive electrode internal electrode 142, and a negative electrode internal electrode 143. Furthermore, one main surface of the piezoelectric actuator chip 140 is designated as the main surface 140a, the main surface opposite to the main surface 140a is designated as the main surface 140b, one side surface is designated as the side surface 140c, and the side surface opposite to the side surface 140c is designated as the side surface 140d. The piezoelectric layer 141 is made of a piezoelectric material such as PZT (lead zirconate titanate).

[0036] The positive electrode internal electrode 142 is made of a conductive material and is provided in the piezoelectric layer 141, facing the negative electrode internal electrode 143 via the piezoelectric layer 141. The positive electrode internal electrode 142 is flat, and if the main surface of the positive electrode internal electrode 142 is considered the electrode surface, the electrode surface is parallel to the main surfaces 140a and 140b. As shown in Figure 8, the positive electrode internal electrode 142 is exposed on the side surface 140c and spaced apart from the side surface 140d. The positive electrode internal electrode 142 is in contact with and electrically connected to a positive electrode external electrode (not shown) formed on the side surface 140c.

[0037] The negative electrode internal electrode 143 is made of a conductive material and is provided in the piezoelectric layer 141, facing the positive electrode internal electrode 142 via the piezoelectric layer 141. The negative electrode internal electrode 143 is flat, and if the main surface of the positive electrode internal electrode 142 is considered the electrode surface, the electrode surface is parallel to the main surfaces 140a and 140b. As shown in Figure 8, the negative electrode internal electrode 143 is exposed on the side surface 140d and spaced apart from the side surface 140c. The negative electrode internal electrode 143 is in contact with and electrically connected to a negative electrode external electrode (not shown) formed on the side surface 140d.

[0038] As shown in Figure 8, the piezoelectric actuator chip 140 has a block 151 and a relaxation layer 152. Each block 151 contains multiple positive internal electrodes 142 and multiple negative internal electrodes 143, and the piezoelectric actuator chip 140 is provided with three blocks 151. The number of positive internal electrodes 142 and negative internal electrodes 143 included in each block 151 is not particularly limited, but can be as many as 50 layers in total. Therefore, the piezoelectric actuator chip 140 can be provided with a total of 150 layers of positive internal electrodes 142 and negative internal electrodes 143 in the three blocks 151. For convenience, in Figure 8, each block 151 is shown to contain three layers each of positive internal electrodes 142 and negative internal electrodes 143.

[0039] The relaxation layer 152 is provided between the blocks 151 and on the main surfaces 140a and 140b of the piezoelectric actuator tip 140. The relaxation layer 152 consists of a thick piezoelectric layer 141. Figure 9 is a schematic diagram showing the thickness of the relaxation layer 152. As shown in the figure, the thickness of the piezoelectric layer 141 between the positive electrode internal electrode 142 and the negative electrode internal electrode 143 within each block 151 is defined as thickness T1, and the thickness of the piezoelectric layer 141 in the relaxation layer 152 is defined as thickness T2. Thickness T2 is thicker than thickness T1, and is preferably twice or more thick than thickness T1. For example, thickness T1 can be 18 μm and thickness T2 can be 36 μm.

[0040] The piezoelectric actuator chip 140 can be formed by forming a positive electrode internal electrode 142 or a negative electrode internal electrode 143 on a piezoelectric plate which will become a piezoelectric layer 141 using a conductive paste, and then stacking and sintering the piezoelectric plates. Here, if there are many stacks of piezoelectric plates, the piezoelectric actuator chip 140 can be formed by forming a sintered body for each block 151 and stacking and pressing the blocks 151 together. In this case, the relaxation layer 152 strengthens the adhesion between the blocks 151 and relieves the internal stress during pressing, making it possible to form a piezoelectric actuator chip 140 with excellent characteristics. Note that the number of blocks 151 is not limited to three, but may be two or fewer, or four or more.

[0041] The piezoelectric actuator chip 140 has the above configuration. Figure 10 is a schematic diagram showing the vibration of the piezoelectric actuator chip 140. When a voltage is applied between the positive internal electrode 142 and the negative internal electrode 143, the piezoelectric actuator chip 140 expands and contracts (arrows in the figure) along a direction perpendicular to the electrode surfaces of the positive internal electrode 142 and the negative internal electrode 143 due to the inverse piezoelectric effect in the piezoelectric layer 141, and vibrates with the same direction as the amplitude. This type of vibration is called the d33 mode. The piezoelectric actuator chip 140 operating in d33 mode can also be driven unipolarly by adding the DC component, thus providing a solution for polarization degradation.

[0042] As described above, the piezoelectric actuator 130 comprises a first piezoelectric actuator chip 131 and a second piezoelectric actuator chip 132, and the first piezoelectric actuator chip 131 and the second piezoelectric actuator chip 132 each have the configuration of a piezoelectric actuator chip 140. Figure 11 is a schematic diagram showing the orientation of the piezoelectric actuator chip 140 that constitutes the piezoelectric actuator 130.

[0043] As shown in the figure, the two piezoelectric actuator chips 140 are stacked in the same direction (Z direction) as the stacking direction, with their vibration direction (arrows in the figure) perpendicular to the longitudinal direction (X direction) of the housing 110, and are housed in the recess 113c. Therefore, the piezoelectric actuator 130 is a piezoelectric actuator that vibrates in d33 mode (hereinafter referred to as a d33 piezoelectric actuator). Since the displacement amount of the d33 piezoelectric actuator is expressed by the following (Equation 1), it is possible to increase the displacement amount by constructing the piezoelectric actuator 130 in multiple stages by stacking two piezoelectric actuator chips 140.

[0044] Δz = d33·v·n (Equation 1) Note that Δz represents the displacement, d33 is the material constant of the piezoelectric layer 141, v is the applied voltage, and n is the number of piezoelectric layers.

[0045] Figure 12 is a plan view showing the recess 113c and the piezoelectric actuator tip 140. As shown in the figure, the piezoelectric actuator tip 140 is smaller than the recess 113c, and it is preferable that the piezoelectric actuator tip 140 is sized such that a gap is formed between it and the recess 113c. As shown in Figure 12, if the length (X direction) of the recess 113c is length L1 and the width (Y direction) is width D1, and the length (X direction) of the piezoelectric actuator tip 140 is length L2 and the width (Y direction) is width D2, then as an example, both length L1 and width D1 can be 4 mm, and both length L2 and width D2 can be 3.5 mm. The gap between the piezoelectric actuator tip 140 and the recess 113c is filled with a sealing material to fix the piezoelectric actuator tip 140 and the support plate 120 to the recess 113c.

[0046] The piezoelectric actuator 130 has the configuration described above. Although the piezoelectric actuator 130 is described as consisting of two piezoelectric actuator chips 140, it may consist of one or three or more piezoelectric actuator chips 140. Furthermore, the piezoelectric actuator 130 may have other configurations as long as it is a d33 piezoelectric actuator whose vibration direction is perpendicular (Z direction) to the longitudinal direction (X direction) of the housing 110.

[0047] [Operation and effects of the input device] Figure 13 is a schematic diagram showing the operation of the input device 100. As described above, the input device 100 drives the piezoelectric actuator 130 to expand and contract along the direction perpendicular to the longitudinal direction (X direction) of the housing 110 (Z direction), causing it to vibrate in d33 mode with the same direction (Z direction) as the amplitude direction. The user of the input device 100 grasps the grip portion 113 of the input device 100 and inputs to the input target surface such as a mobile device. Since the piezoelectric actuator 130 is provided on the grip portion 113, the input device 100 can provide the user with realistic tactile feedback.

[0048] In this case, the vibration direction (Z direction) of the piezoelectric actuator 130 coincides with the pressing direction (Z direction) of the fingers gripping the grip portion 113, making it possible to advantageously utilize the force generated by the piezoelectric actuator 130 in this direction (Z direction). Furthermore, since the d33 piezoelectric actuator has the greatest durability against vibration, the durability of the piezoelectric actuator 130 can be improved.

[0049] Furthermore, since the piezoelectric actuator 130 does not have a motor or other mechanical drive part and is composed of a small, lightweight, and low-power piezoelectric actuator chip 140, it is possible to reduce the space and power consumption of the piezoelectric actuator 130. In addition, because the piezoelectric actuator 130 has high high-speed response, the input device 100 can provide tactile feedback that takes advantage of this high-speed response.

[0050] [Regarding drive signals] The drive signal output to the piezoelectric actuator 130 will now be described. As described above, this drive signal is a voltage waveform applied between the positive internal electrode 142 and the negative internal electrode 143 of the piezoelectric actuator chip 140. This drive signal may be supplied to the piezoelectric actuator 130 from a drive unit mounted on the input device 100, or it may be supplied to the piezoelectric actuator 130 via wireless communication or the like from a drive unit mounted on a device other than the input device 100.

[0051] The drive signal output by the drive unit to the piezoelectric actuator 130 has a waveform in which a signal wave with a frequency of 50 Hz to 350 Hz is used as the modulated wave, and a sine wave with a frequency equal to the resonant frequency of the housing 110 is amplitude-modulated by the modulated wave. Here, vibrations of 50 Hz to 350 Hz are vibrations that can be sensitively felt by receptors in human skin such as Meissner's corpuscles and Pacinian corpuscles. The resonant frequency of the housing 110 is determined by the material of the pen tip portion 111 and the grip portion 113, and is preferably between 20 kHz and 110 kHz.

[0052] Figure 14 shows voltage and current waveforms with amplitude-modulated waveforms obtained by using a sine wave with a first frequency as the modulating wave and amplitude-modulating a sine wave with a second frequency using this modulating wave. Figure 15 is an enlarged view of Figure 14. When the voltage waveform shown in Figure 14 is applied as a drive signal from the drive unit to the piezoelectric actuator 130, a current with the current waveform shown in Figure 14 flows.

[0053] Figure 16 shows only the voltage waveform from Figure 14, and Figure 17 shows only the voltage waveform from Figure 15. In Figures 16 and 17, the wave with a longer wavelength indicated by W1 is a sine wave with a first frequency, and the wave with a shorter wavelength indicated by W2 is a sine wave with a second frequency. Hereafter, the sine wave with the first frequency will be referred to as the first sine wave W1, and the sine wave with the second frequency will be referred to as the second sine wave W2.

[0054] In the waveforms shown in Figures 16 and 17, the first sine wave W1 is formed by a change in the amplitude of the second sine wave W2. That is, the waveforms shown in Figures 16 and 17 are amplitude-modulated waves with the second sine wave W2 as the carrier wave and the first sine wave W1 as the modulating wave. The drive unit can generate a drive signal having a waveform of amplitude-modulated waves with the second sine wave W2 having the resonant frequency of the housing 110 as the carrier wave and the first sine wave W1 having a frequency between 50 Hz and 350 Hz as the modulating wave, and apply it to the piezoelectric actuator 130.

[0055] Figure 18 is a schematic diagram showing the relationship between the waveform and voltage gain of an amplitude-modulated wave. As shown in the figure, if the amplitude of the "peak" of the amplitude-modulated wave is amplitude a and the amplitude of the "trough" is amplitude b, the modulation degree m is expressed by the following equation (2). As shown in equation (2) below, the smaller the amplitude b is relative to the amplitude a, the larger the modulation degree m becomes.

[0056] m = (ab) / (a ​​+ b) (Equation 2)

[0057] In Figure 18, as shown by the white arrow in Figure 16, increasing the voltage gain of the first sine wave W1 deepens the "trough" of the first sine wave W1, and setting the voltage gain of the first sine wave W2 to 0 dB minimizes the amplitude of the "trough." Conversely, lowering the voltage gain of the first sine wave W1 makes the "trough" of the first sine wave W1 shallower and increases the amplitude. Furthermore, lowering the voltage gain of the first sine wave W1 makes the amplitude b of the "trough" of the first sine wave W1 equal to the amplitude of the "peak," eliminating the formation of a "trough." In this embodiment, the modulation degree m is adjusted within the range of 80% to 100%, allowing the amplitude modulation difference to be used for tactile expression. Additionally, since current consumption is reduced in the portion where the voltage is reduced, it is possible to achieve low power consumption. In the above explanation, the amplitude-modulated wave is described using a first sine wave W1 and a second sine wave W2, but the amplitude-modulated wave may be formed by waves other than sine waves.

[0058] The drive unit uses a signal wave with a frequency of 50Hz to 350Hz as the modulating wave, and supplies a drive signal to the piezoelectric actuator 130 having a waveform obtained by amplitude modulating a sine wave whose frequency is the resonant frequency of the housing 110 with the modulating wave. When the tip 111b (see Figure 13) of the input device 100 is moved while in contact with the input target surface, the user can feel pressure and buoyancy from the input device 100 in the opposite direction of movement. Furthermore, it is possible to adjust this pressure and buoyancy by changing the frequency of the modulating wave, making it possible to reproduce different types of writing instruments such as pencils, crayons, and brushes, as well as different materials of the input target surface such as Western paper, Japanese paper, and wood grain.

[0059] (Second embodiment) An input device according to a second embodiment of the present invention will now be described.

[0060] [Input device configuration] Figure 19 is a plan view of the input device 200 according to this embodiment, and Figure 20 is a partially enlarged view of Figure 19. As shown in these figures, the input device 200 is a stylus pen type input device and comprises a housing 210 and a piezoelectric actuator 230.

[0061] The housing 210 has a pen-like shape as shown in Figure 19. Hereinafter, the longitudinal direction of the housing 210 will be referred to as the X direction, one direction perpendicular to the X direction will be referred to as the Y direction, and the direction perpendicular to both the X and Z directions will be referred to as the Z direction. As shown in Figure 19, the housing 210 comprises a pen shaft portion 211 and a pen tip portion 212.

[0062] The pen shaft portion 211 is the part that constitutes the pen shaft of the pen-shaped housing 210. The pen shaft portion 211 is made of a resin such as polycarbonate or a metal such as stainless steel. The pen tip portion 212 is the part that constitutes the pen tip of the pen-shaped housing 210. The pen tip portion 212 includes a tip portion 213 and a connecting portion 214. The tip portion 213 is a metal pin made of a metal such as stainless steel that protrudes from the piezoelectric actuator 230 along the longitudinal direction (X direction) of the housing 210. The connecting portion 214 is positioned between the piezoelectric actuator 230 and the pen shaft portion 211 and connects them. The connecting portion 214 is made of metal or resin. Note that the connecting portion 214 may be omitted, and the piezoelectric actuator 230 may be directly connected to the pen shaft portion 211.

[0063] The piezoelectric actuator 230 generates vibrations, causing a tactile sensation in the input device 200. As shown in Figure 20, the piezoelectric actuator 230 is positioned on the pen tip portion 212 and is bonded to the tip portion 213 and the connection portion 214 with an adhesive such as epoxy resin. As shown in Figure 20, the piezoelectric actuator 230 is constructed by stacking two piezoelectric actuator chips, a first piezoelectric actuator chip 231 and a second piezoelectric actuator chip 232.

[0064] The first piezoelectric actuator chip 231 and the second piezoelectric actuator chip 232 can be piezoelectric actuator chips having the same structure, and can be configured with the piezoelectric actuator chip 140 (see Figure 8) according to the first embodiment. That is, the first piezoelectric actuator chip 231 and the second piezoelectric actuator chip 232 expand and contract along a direction perpendicular to the electrode surfaces of the positive electrode internal electrode 142 and the negative electrode internal electrode 143, and vibrate with the same direction as the amplitude direction.

[0065] On the other hand, the orientation of the piezoelectric actuator chip 140 differs from that of the first embodiment. Figure 21 is a schematic diagram showing the orientation of the piezoelectric actuator chip 140 that constitutes the piezoelectric actuator 230. As shown in the figure, the two piezoelectric actuator chips 140 are stacked in a direction (X direction) parallel to the longitudinal direction (X direction) of the housing 110, with this direction (X direction) as the stacking direction, and are arranged in the pen tip portion 212.

[0066] Therefore, the piezoelectric actuator 230 is a d33 piezoelectric actuator that vibrates in d33 mode. Since the displacement of the d33 piezoelectric actuator is expressed by (Equation 1) above, it is possible to increase the displacement by constructing the piezoelectric actuator 230 in multiple stages by stacking two piezoelectric actuator chips 140.

[0067] The piezoelectric actuator 230 has the configuration described above. Although the piezoelectric actuator 230 is described as consisting of two piezoelectric actuator chips 140, it may consist of one or three or more piezoelectric actuator chips 140. Furthermore, the piezoelectric actuator 230 may have other configurations as long as it is a d33 piezoelectric actuator whose vibration direction is parallel to the longitudinal direction (X direction) of the housing 110.

[0068] [Operation and effects of the input device] Figure 22 is a schematic diagram showing the operation of the input device 200. As described above, the input device 200 drives the piezoelectric actuator 230 to expand and contract along a direction parallel to the longitudinal direction (X direction) of the housing 210, causing it to vibrate in d33 mode with the same direction (X direction) as the amplitude direction. The user of the input device 200 grasps the pen shaft portion 211 of the input device 200 and inputs to an input target surface such as a mobile device. However, since the piezoelectric actuator 230 is provided on the pen tip portion 212, the user can perceive the tactile sensation generated by the piezoelectric actuator 230 as if it were tactile sensation from the input target surface.

[0069] In this case, the vibration direction (X direction) of the piezoelectric actuator 230 coincides with the pushing direction (X direction) of the input device 100 toward the input target surface, making it possible to advantageously utilize the force generated by the piezoelectric actuator 230 in this direction (X direction). Furthermore, since the d33 piezoelectric actuator has the greatest durability against vibration, the durability of the piezoelectric actuator 230 can be improved.

[0070] Furthermore, since the piezoelectric actuator 230 does not have mechanical drive parts such as a motor and is composed of a small, lightweight, and low-power piezoelectric actuator chip 140, it is possible to reduce the space and power consumption of the piezoelectric actuator 230. In addition, because the piezoelectric actuator 230 has high high-speed response, the input device 200 can provide tactile feedback that takes advantage of this high-speed response.

[0071] [Regarding drive signals] The drive signal output to the piezoelectric actuator 230 will now be described. As described above, this drive signal is a voltage waveform applied between the positive internal electrode 142 and the negative internal electrode 143 of the piezoelectric actuator chip 140. This drive signal may be supplied to the piezoelectric actuator 230 from a drive unit mounted on the input device 200, or it may be supplied to the piezoelectric actuator 230 via wireless communication or the like from a drive unit mounted on a device other than the input device 200.

[0072] (Drive signal 1) The drive signal output by the drive unit to the piezoelectric actuator 230 can have a waveform in which a signal wave with a frequency of 50 Hz to 350 Hz is used as the modulated wave, and a sine wave with a frequency equal to the resonant frequency of the housing 210 is amplitude-modulated by the modulated wave. Here, vibrations of 50 Hz to 350 Hz are vibrations that can be sensitively felt by receptors in human skin such as Meissner's corpuscles and Pacinian corpuscles. The resonant frequency of the housing 210 is determined by the material of the pen tip portion 212, and is preferably between 20 kHz and 110 kHz.

[0073] In the waveforms shown in Figures 16 and 17, described in the first embodiment, the first sine wave W1 is formed by a change in the amplitude of the second sine wave W2. That is, the waveforms shown in Figures 16 and 17 are amplitude-modulated waves with the second sine wave W2 as the carrier wave and the first sine wave W1 as the modulating wave. The drive unit can generate a drive signal having a waveform of an amplitude-modulated wave with the second sine wave W2 having the resonant frequency of the housing 210 as the carrier wave and the first sine wave W1 having a frequency of 50 Hz or more and 350 Hz or less as the modulating wave, and apply it to the piezoelectric actuator 230.

[0074] The modulation degree m (see Equation 2 above) is adjusted within a range of 80% to 100%, and the amplitude modulation difference can be used for tactile expression. Furthermore, since the current consumption is reduced in the portion where the voltage is reduced, it is possible to achieve low power consumption. In the above explanation, the amplitude modulated wave is described using a first sine wave W1 and a second sine wave W2, but the amplitude modulated wave may be formed by waves other than sine waves.

[0075] The drive unit uses a signal wave with a frequency of 50Hz to 350Hz as the modulating wave, and supplies a drive signal to the piezoelectric actuator 230 having a waveform obtained by amplitude modulating a sine wave whose frequency is the resonant frequency of the housing 210 with the modulating wave. When the tip 213 (see Figure 20) of the input device 200 is moved while in contact with the input target surface, the user can feel pressure and buoyancy from the input device 200 in the opposite direction of movement. Furthermore, it is possible to adjust this pressure and buoyancy by changing the frequency of the modulating wave, making it possible to reproduce different types of writing instruments such as pencils, crayons, and brushes, as well as different materials of the input target surface such as Western paper, Japanese paper, and wood grain.

[0076] (Drive signal 2) The drive signal output by the drive unit to the piezoelectric actuator 230 may have a waveform in which a signal wave with a frequency of 2 Hz to 50 Hz is used as the modulating wave, and a sine wave with a frequency of 150 Hz to 250 Hz is amplitude-modulated by the modulating wave. As shown in Figures 16 and 17, the drive unit can generate a drive signal having a waveform of amplitude-modulated wave with a second sine wave W2 with a frequency of 150 Hz to 250 Hz as the carrier wave and a first sine wave W1 with a frequency of 2 Hz to 50 Hz as the modulating wave, and apply it to the piezoelectric actuator 230.

[0077] The modulation degree m (see Equation 2 above) is adjusted within a range of 80% to 100%, and the amplitude modulation difference can be used for tactile expression. Furthermore, since the current consumption is reduced in the portion where the voltage is reduced, it is possible to achieve low power consumption. In the above explanation, the amplitude modulated wave is described using a first sine wave W1 and a second sine wave W2, but the amplitude modulated wave may be formed by waves other than sine waves.

[0078] The drive unit supplies the piezoelectric actuator 230 with a drive signal having a waveform obtained by using a signal wave with a frequency of 2 Hz to 50 Hz as the modulating wave, and amplitude-modulating a sine wave with a frequency of 150 Hz to 250 Hz with the modulating wave. When the tip 213 (see Figure 20) of the input device 200 is brought into contact with the input target surface, the user can feel a clicking sensation from the input device 200. This allows the user to understand, through touch, that input is being made by the input device 200. Furthermore, this tactile sensation can be adjusted by changing the frequency of the modulating wave.

[0079] (Example of a drive signal) Figure 23 shows an example of an amplitude-modulated wave where the first sine wave W1 is 2.5 Hz and the second sine wave W2 is 250 Hz. The modulation is 100%, and it is generated to fade in over 4 waves. Figure 24 shows an example of an amplitude-modulated wave where the first sine wave W1 is 25 Hz and the second sine wave W2 is 250 Hz. The modulation is 100%, and it is generated to fade in over 5 waves and fade out in 1-second increments. [Explanation of symbols]

[0080] 100, 200... Input devices 110, 210... cabinet 111, 212... Pen tip 112, 211... Pen shaft portion 113... Grip part 120...Support plate 130, 230... Piezoelectric actuators 131, 231…First piezoelectric actuator chip 132, 232… Second piezoelectric actuator chip 140… Piezoelectric actuator chip 141... Piezoelectric layer 142... Positive electrode internal electrode 143…Negative internal electrode 151…block 152...Relaxation layer

Claims

1. A pen-shaped housing having a pen tip portion, a pen shaft portion, and a grip portion located between the pen tip portion and the pen shaft portion and held by the user's fingers, with the first direction being the longitudinal direction, Mounted in the housing, the piezoelectric actuator comprises a piezoelectric layer made of piezoelectric material, a positive electrode internal electrode provided in the piezoelectric layer, and a negative electrode internal electrode provided in the piezoelectric layer and facing the positive electrode internal electrode via the piezoelectric layer, wherein when a voltage is applied between the positive electrode internal electrode and the negative electrode internal electrode, the piezoelectric actuator expands and contracts along a direction perpendicular to the electrode surfaces of the positive electrode internal electrode and the negative electrode internal electrode. It is equipped with, The piezoelectric actuator is mounted on the grip portion in a orientation such that the direction perpendicular to the electrode surface is perpendicular to the first direction, and vibrates in a direction perpendicular to the first direction. Input device.

2. An input device according to claim 1, The housing has a recess provided in the grip portion, The piezoelectric actuator is housed in the recess and sealed by a sealing material. Input device.

3. An input device according to claim 1 or 2, The piezoelectric actuator consists of a plurality of piezoelectric actuator chips, and the plurality of piezoelectric actuator chips are stacked with a stacking direction perpendicular to the first direction. Input device.

4. An input device according to any one of claims 1 to 3, The housing has a predetermined resonant frequency, The device further comprises a drive unit that supplies a drive signal to the positive and negative internal electrodes, having a waveform obtained by amplitude-modulating a sine wave whose frequency is the resonant frequency with the modulated signal wave, which is a signal wave with a frequency of 50 Hz or more and 350 Hz or less. Input device.

5. An input device according to claim 4, The aforementioned resonant frequency is between 20 kHz and 110 kHz. Input device.

6. A pen-shaped housing having a pen shaft portion that is held by the user's hand and a pen tip portion connected to the pen shaft portion, with the first direction being the longitudinal direction, Mounted in the housing, the piezoelectric actuator comprises a piezoelectric layer made of piezoelectric material, a positive electrode internal electrode provided in the piezoelectric layer, and a negative electrode internal electrode provided in the piezoelectric layer and facing the positive electrode internal electrode via the piezoelectric layer, wherein when a voltage is applied between the positive electrode internal electrode and the negative electrode internal electrode, the piezoelectric actuator expands and contracts along a direction perpendicular to the electrode surfaces of the positive electrode internal electrode and the negative electrode internal electrode. It is equipped with, The piezoelectric actuator is mounted on the pen tip portion, away from the pen shaft portion, in a direction perpendicular to the electrode surface and parallel to the first direction, and vibrates in a direction parallel to the first direction. Input device.

7. An input device according to claim 6, The pen tip portion includes a connecting portion made of metal or resin that connects the pen shaft portion and the piezoelectric actuator. Input device.

8. An input device according to claim 6 or 7, The pen tip portion protrudes from the piezoelectric actuator along the first direction and has a tip made of metal. Input device.

9. An input device according to any one of claims 6 to 8, The piezoelectric actuator consists of a plurality of piezoelectric actuator chips, and the plurality of piezoelectric actuator chips are stacked with the first direction as the stacking direction. Input device.

10. An input device according to any one of claims 6 to 9, The housing has a predetermined resonant frequency, The device further comprises a drive unit that supplies a drive signal to the positive and negative internal electrodes, having a waveform obtained by amplitude-modulating a sine wave whose frequency is the resonant frequency with the modulated signal wave, which is a signal wave with a frequency of 50 Hz or more and 350 Hz or less. Input device.

11. An input device according to claim 10, The aforementioned resonant frequency is between 20 kHz and 110 kHz. Input device.

12. An input device according to any one of claims 6 to 9, The housing has a predetermined resonant frequency, The device further comprises a drive unit that supplies a drive signal having a waveform obtained by amplitude-modulating a signal wave with a frequency of 2 Hz to 50 Hz as the modulated wave, and a sine wave with a frequency of 150 Hz to 250 Hz with the modulated wave, to the positive electrode internal electrode and the negative electrode. Input device.

13. An input device according to claim 3 or 9, The piezoelectric actuator chip comprises a plurality of blocks, each containing a predetermined number of positive and negative internal electrodes, with a relaxation layer provided between the plurality of blocks. The relaxation layer is a piezoelectric layer that is thicker than the piezoelectric layer between the positive electrode and the negative electrode within the block. Input device.

14. A pen-shaped housing having a pen tip portion, a pen shaft portion, and a grip portion located between the pen tip portion and the pen shaft portion and grasped by the user's fingers, with the first direction being the longitudinal direction; a piezoelectric layer made of a piezoelectric material mounted on the housing; a positive electrode internal electrode provided in the piezoelectric layer; a negative electrode internal electrode provided in the piezoelectric layer and facing the positive electrode internal electrode via the piezoelectric layer; a piezoelectric actuator that expands and contracts along a direction perpendicular to the electrode surfaces of the positive electrode internal electrode and the negative electrode internal electrode when a voltage is applied between the positive electrode internal electrode and the negative electrode internal electrode; and an input device mounted on the grip portion such that the direction perpendicular to the electrode surfaces is perpendicular to the first direction and vibrates in a direction perpendicular to the first direction. A drive unit that supplies drive signals to the positive electrode internal electrode and the negative electrode internal electrode. An input system equipped with the following features.

15. A pen-shaped housing having a pen shaft portion for the user's hand to grasp and a pen tip portion connected to the pen shaft portion, with the first direction being the longitudinal direction; a piezoelectric layer made of a piezoelectric material mounted on the housing; a positive electrode internal electrode provided in the piezoelectric layer; a negative electrode internal electrode provided in the piezoelectric layer and facing the positive electrode internal electrode via the piezoelectric layer; a piezoelectric actuator that expands and contracts along a direction perpendicular to the electrode surfaces of the positive electrode internal electrode and the negative electrode internal electrode when a voltage is applied between the positive electrode internal electrode and the negative electrode internal electrode; and an input device mounted on the pen tip portion away from the pen shaft portion in a direction parallel to the first direction, with the direction perpendicular to the electrode surface being parallel to the first direction; A drive unit that supplies drive signals to the positive electrode internal electrode and the negative electrode internal electrode. An input system equipped with the following features.

16. A piezoelectric actuator is mounted on a pen-shaped housing having a pen tip portion, a pen shaft portion, and a grip portion located between the pen tip portion and the pen shaft portion and held by the user's fingers, with the first direction being the longitudinal direction, and comprising a piezoelectric layer made of a piezoelectric material, a positive electrode internal electrode provided in the piezoelectric layer, and a negative electrode internal electrode provided in the piezoelectric layer and facing the positive electrode internal electrode via the piezoelectric layer, wherein when a voltage is applied between the positive electrode internal electrode and the negative electrode internal electrode, the piezoelectric actuator expands and contracts along a direction perpendicular to the electrode surfaces of the positive electrode internal electrode and the negative electrode internal electrode, and is mounted on the grip portion in a orientation such that the direction perpendicular to the electrode surfaces is perpendicular to the first direction, and vibrates in a direction perpendicular to the first direction, and a drive signal is supplied to the positive electrode internal electrode and the negative electrode internal electrode of the piezoelectric actuator. A method for driving an input device.

17. A piezoelectric actuator is mounted on a pen-shaped housing having a pen shaft portion for a user's hand to grasp and a pen tip portion connected to the pen shaft portion, with the first direction being the longitudinal direction, and comprising a piezoelectric layer made of a piezoelectric material, a positive electrode internal electrode provided in the piezoelectric layer, and a negative electrode internal electrode provided in the piezoelectric layer and facing the positive electrode internal electrode via the piezoelectric layer, wherein when a voltage is applied between the positive electrode internal electrode and the negative electrode internal electrode, the piezoelectric actuator expands and contracts along a direction perpendicular to the electrode surfaces of the positive electrode internal electrode and the negative electrode internal electrode, and is mounted on the pen tip portion away from the pen shaft portion in a direction parallel to the first direction, with the direction perpendicular to the electrode surfaces being parallel to the first direction, and a drive signal is supplied to the positive electrode internal electrode and the negative electrode internal electrode of the piezoelectric actuator. A method for driving an input device.

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