KR102282485B1 - Haptic display device and method for driving the same - Google Patents

Abstract

In order to solve the problems described above, a display device according to an embodiment of the present invention is provided. The display device includes a display unit configured to display an image, an actuator, and an actuator driving unit. The actuator includes an electroactive layer and a plurality of electrodes disposed on one surface of the electroactive layer. The actuator driver is controlled to apply different voltages to the plurality of electrodes. Here, the actuator driver is driven to apply different voltages to each of the adjacent electrodes among the plurality of electrodes in order to provide a sense of vibration. Further, in order to provide a texture, it is driven to apply the same voltage to each of the adjacent electrodes among the plurality of electrodes. In addition, the actuator driving unit may provide a desired haptic feeling by controlling the applied voltage according to whether a sense of vibration or texture is required. Since various haptic sensations may be provided through a single structure, the display device may be lightweight and have a reduced thickness.

Description

Haptic display device and driving method thereof

The present invention relates to a haptic display device and a driving method thereof, and more particularly, to a haptic display device capable of providing various haptic sensations and a driving method thereof.

The touch sensing unit is a device that detects a user's touch input such as a screen touch or a gesture on the display device, and includes portable display devices such as smartphones and tablet PCs, and large display devices such as display devices and smart TVs in public facilities. It is widely used in devices. Such a touch sensing unit is classified into a resistive film type, a capacitive type, an ultrasonic type, an infrared type, and the like according to an operation method.
However, recently, it is not limited to sensing the user's touch input, but as feedback on the user's touch input, a haptic device that delivers tactile feedback that can be felt with the user's finger or the user's stylus pen has been developed. Research is ongoing.
As such a haptic device, a haptic device to which an eccentric rotating mass (ERM) is applied to a display device is used. ERM is a vibration motor that generates mechanical vibration due to eccentric force generated when the motor rotates by attaching a mass to one side of the rotating part of the motor. However, since the ERM is made of an opaque material, it should be disposed on the rear surface of the display unit rather than the front surface of the display unit in the display device. In addition, since the ERM generates vibration by a motor, not only a specific part of the display device vibrates, but the entire display device vibrates. Accordingly, in the display device to which the ERM is applied, there is a problem that the tactile feedback cannot be transmitted only to the portion where the user's touch input is generated. In addition, since the ERM has a very slow response speed in that it generates mechanical vibration through a motor, it is difficult to be used as a vibration source for a haptic device. In addition, since the ERM is a rigid modular component, it is difficult to be applied to a flexible display device.
Meanwhile, as a haptic device, a haptic device to which a Linear Resonant Actuator (LRA) is applied to a display device is also used. LRA delivers tactile feedback through the vibration of a spring and stainless steel vibrator generated by the reciprocating motion of a permanent magnet inside a solenoid. However, since the LRA is made of an opaque material like the ERM and vibrates the entire display device, the same problem as the ERM exists. In addition, since the LRA must use a resonant frequency, the vibration frequency is fixed between 150 Hz and 200 Hz. Accordingly, the haptic device to which the LRA is applied has a disadvantage in that it is difficult to generate various senses of vibration.
In order to solve the above-described problems, a haptic device to which a piezo ceramic actuator is applied is used. The piezoelectric ceramic actuator has a fast response speed of several msec, and the vibration frequency range is very wide, so it can realize vibration in all frequency ranges that humans actually feel. However, the piezoelectric ceramic actuator is manufactured in the form of a plate made of a ceramic material, and thus has low durability against external shock and is easily broken by external shock. In addition, the piezoelectric ceramic actuator is opaque like ERM and LRA, it is difficult to reduce the thickness, and it is disposed on the rear surface of the display device to vibrate the entire display device.
[Related technical literature]
Method and apparatus for providing haptic cues for guidance and alignment by electrostatic friction (Korean Patent Application No. 2013-0140928)

A structure employing an electroactive polymer as a vibration source for generating vibration in a haptic device may be used. Specifically, the structure employing the electroactive polymer may transmit tactile feedback to the user through vibration of the electroactive layer generated by applying a voltage to the electrodes disposed above and below the electroactive layer made of the electroactive polymer. Since such a structure may be made of transparent materials, it has an advantage that it can be applied to the entire surface of the display device, and a wide range of driving frequencies can exhibit various vibration sensations. However, the structure using the electroactive polymer can transmit only the tactile sense caused by vibration and cannot transmit the texture of the object displayed on the display device.
Meanwhile, as a structure for transferring the texture of an object displayed on the display device, there is a structure using electrostatic attraction. Specifically, in a structure using electrostatic attraction, an electrode is disposed on one surface of the insulating layer. When a voltage is applied to the electrode and a finger comes into contact, a Coulomb force, which is an electrostatic attraction between the finger and the insulating layer, is generated. In that state, when a finger is moved on the insulating layer, electrical texture is transmitted through horizontal friction. However, in the structure using electrostatic attraction, there is a problem in that the touch is not transmitted when the finger stops.
Accordingly, the inventors of the present invention have developed a structure in which an electrode is disposed on one surface of an electroactive layer in a structure employing an electroactive polymer and a tactile sense caused by texture and vibration in one structure through driving with different voltages applied to the electrode. A new haptic display device that can be simultaneously implemented has been invented.
Accordingly, an object of the present invention is to provide a haptic display device capable of switching between driving for transmitting a sense of vibration and driving for transmitting a texture to an object, and a driving method thereof.
The problems of the present invention are not limited to the problems mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the following description.

In order to solve the above problems, a display device according to an embodiment of the present invention is provided. The display device includes a display unit configured to display an image, an actuator, and an actuator driving unit. The actuator includes an electroactive layer and a plurality of electrodes disposed on one surface of the electroactive layer. The actuator driver is controlled to apply different voltages to the plurality of electrodes. Here, the actuator driver is driven to apply different voltages to each of the adjacent electrodes among the plurality of electrodes in order to provide a sense of vibration. In addition, in order to provide a texture, it is driven to apply the same voltage to each of the adjacent electrodes among the plurality of electrodes. In addition, the actuator driving unit may provide a desired haptic feeling by controlling the applied voltage according to whether a sense of vibration or texture is required. In addition, since various haptic sensations may be provided through one actuator, the display device may be lightweight and thin.
The details of other embodiments are included in the detailed description and drawings.

According to the embodiments of the present invention, there are at least the following effects.
In the present invention, since the vibration and the texture of the object are implemented in one structure through different driving methods, the gap between the structure that generates the tactile sense and the finger that recognizes the tactile sense is minimized, Accordingly, it is possible to provide a realistic feeling such as a more detailed texture and dynamic input feedback.
The effect according to the present invention is not limited by the contents exemplified above, and more various effects are included in the present specification.

1 is a block diagram of a display device according to an exemplary embodiment.
2 is an exploded perspective view of a display device according to an exemplary embodiment.
3 is a perspective view illustrating an actuator of a display device according to an exemplary embodiment.
4A and 5A are schematic cross-sectional views illustrating driving of a display device and tactile sensation felt by a user according to an exemplary embodiment of the present invention.
4B and 5B are schematic diagrams for explaining driving of a display device according to an exemplary embodiment.
4C and 5C are schematic diagrams for explaining an example of driving a display device according to an exemplary embodiment.
6 is a schematic diagram for explaining driving conversion of a display device according to an exemplary embodiment.
7A is a schematic plan view illustrating an actuator of a display device according to another exemplary embodiment.
7B is a schematic enlarged plan view illustrating a cell of an actuator of a display device according to an exemplary embodiment of the present invention.
8 to 10 are schematic enlarged plan views for explaining an actuator of a display device according to various embodiments of the present disclosure.
11 is a flowchart illustrating a method of driving a display device according to another exemplary embodiment.
12 is a diagram illustrating examples in which a display device according to various embodiments of the present disclosure may be advantageously utilized.

Advantages and features of the present invention and methods of achieving them will become apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in a variety of different forms, and only these embodiments allow the disclosure of the present invention to be complete, and common knowledge in the technical field to which the present invention belongs It is provided to fully inform the possessor of the scope of the invention, and the present invention is only defined by the scope of the claims.
The shapes, sizes, proportions, angles, numbers, etc. disclosed in the drawings for explaining the embodiments of the present invention are exemplary, and thus the present invention is not limited to the illustrated matters. Like reference numerals refer to like elements throughout. In addition, in describing the present invention, if it is determined that a detailed description of a related known technology may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted. When 'including', 'having', 'consisting', etc. mentioned in this specification are used, other parts may be added unless 'only' is used. When a component is expressed in the singular, the case in which the plural is included is included unless otherwise explicitly stated.
In interpreting the components, it is interpreted as including an error range even if there is no separate explicit description.
In the case of a description of the positional relationship, for example, when the positional relationship of two parts is described as 'on', 'on', 'on', 'beside', etc., 'right' Alternatively, one or more other parts may be positioned between the two parts unless 'directly' is used.
Reference to a device or layer “on” another device or layer includes any intervening layer or other device directly on or in the middle of another device.
Although first, second, etc. are used to describe various elements, these elements are not limited by these terms. These terms are only used to distinguish one component from another. Accordingly, the first component mentioned below may be the second component within the spirit of the present invention.
Like reference numerals refer to like elements throughout.
The size and thickness of each component shown in the drawings are illustrated for convenience of description, and the present invention is not necessarily limited to the size and thickness of the illustrated component.
Each feature of the various embodiments of the present invention may be partially or wholly combined or combined with each other, and technically various interlocking and driving are possible, as will be fully understood by those skilled in the art, and each embodiment may be independently implemented with respect to each other, It may be possible to implement together in a related relationship.
Hereinafter, various embodiments of the present invention will be described in detail with reference to the accompanying drawings.
1 is a block diagram of a display device according to an exemplary embodiment. 2 is an exploded perspective view of a display device according to an exemplary embodiment. 1 and 2, the display device 100 includes an actuator 110, an actuator driving unit 120, a touch sensing unit 130, a touch circuit unit 140, a display unit 150, a timing control unit 160, It includes a processor 170 , an upper cover 180 , and a lower cover 190 . In FIG. 2 , the actuator driving unit 120 , the touch circuit unit 140 , the timing control unit 160 , and the processor 170 are omitted.
The actuator 110 applies a voltage to the plurality of electrodes 114 disposed under the electroactive layer 112 made of an electroactive polymer, and the vibration of the electroactive layer 112 is generated between the user's finger and the electrode. It delivers the texture to the user through electrostatic attraction and friction according to the movement of the fingers. The actuator 110 is made of transparent materials. The actuator 110 may provide a tactile sense in a localized area through the plurality of electrodes 114 . Referring to FIG. 2 , the actuator 110 includes an electroactive layer 112 and a plurality of electrodes 114 . The plurality of electrodes 114 are disposed on the same surface of the electroactive layer 112 .
The actuator driving unit 120 controls a voltage for driving the actuator 110 in response to the received vibration driving signal. The actuator driving unit 120 is configured to provide voltages of various magnitudes and various frequencies. In addition, the actuator 110 may form various electric fields to provide both a texture and a sense of vibration to an object. To this end, the actuator driver 120 may be configured to apply different voltages to each of the plurality of electrodes 114 . The actuator driving unit 120 is configured to change a voltage application method in response to an input of the processor 170 or the touch sensing unit 130 . For example, the actuator driver 120 may determine an applied voltage to each of the plurality of electrodes 114 of the actuator 110 , and transmit the applied voltage to each of the plurality of electrodes 114 . A detailed description of the structure of the actuator 110 and the operation of the actuator driving unit 120 will be described later with reference to FIGS. 3 to 6 .
An upper cover 180 is disposed on the actuator 110 . The upper cover 180 is configured to protect the display device 100 from an impact from the outside of the display device 100 . The upper cover 180 may be made of a transparent insulating material such as plastic or glass.
The touch sensing unit 130 is disposed under the actuator 110 . The touch sensing unit 130 refers to a panel that detects a user's touch input to the display device 100 . As the touch sensing unit 130 , for example, a capacitive type, a resistive type, an ultrasonic type, an infrared type, etc. may be used, but preferably a resistive type touch sensing unit may be used as the touch sensing unit 130 . there is. The touch circuit unit 140 is configured to receive a touch input signal from the touch sensing unit 130 and output various touch output signals related to the touch. The touch circuit unit 140 may output a touch output signal to the actuator driver 120 and the processor 170 . However, when the touch sensing unit 130 is a capacitive touch sensing unit, the touch sensing unit 130 may be disposed on the actuator 110 to more easily detect a change in capacitance.
The display unit 150 is disposed under the touch sensing unit 130 . The display unit 150 refers to a panel on which a display element for displaying an image in the display device 100 is disposed. As the display unit 150 , for example, various display units such as an organic light emitting display unit, a liquid crystal display unit, an electrophoretic display unit, and the like may be used. The display unit 150 may include a flexible substrate and may be a flexible display unit. The flexible display unit may be deformed in various directions and angles by external force. The timing controller 160 is configured to drive the display unit 150 using a scan control signal, a data control signal, etc. based on an input image.
The lower cover 190 is disposed under the display unit 150 to cover the lower portions of the actuator 110 , the touch sensing unit 130 , and the display unit 150 . The lower cover 190 protects internal components of the display device 100 from external impact and penetration of foreign substances or moisture. For example, the lower cover 190 may be made of a material such as glass having good hardness or plastic having good processability and can be thermoformed, but is not limited thereto. In addition, the lower cover 190 may be made of a material that can be deformed together according to the change in ductility and shape of the actuator 110 . For example, the lower cover 190 may be made of a material such as plastic having flexibility, but is not limited thereto.
Although not shown in FIG. 2 , an adhesive layer for bonding the actuator 110 , the touch sensing unit 130 , the display unit 150 , the upper cover 180 , and the lower cover 190 to each other may be used. The adhesive layer may be, for example, optical clear adhesive (OCA) or optical clear resin (OCR), but is not limited thereto.
The processor 170 may be a computing device such as a multimedia application processor (MAP), a microcontroller (MCU), an image signal processor (ISP), etc. as a means for performing various operations. The processor 170 may process an image and output a vibration driving signal to the actuator 110 in response to a touch output signal from the touch circuit unit 140 .
3 is a perspective view illustrating an actuator of a display device according to an exemplary embodiment. Referring to FIG. 3 , the actuator 110 includes an electroactive layer 112 , a plurality of electrodes 114 , and wiring 116 .
The electroactive layer 112 is a plate-shaped film made of an electroactive polymer, which is a polymer material that is deformed by electrical stimulation. For example, the electroactive layer 112 may be made of a dielectric elastomer such as silicone-based, urethane-based, or acrylic-based, or a ferroelectric polymer such as PVDF or PVDF-TrFE. When the electroactive layer 112 is made of a dielectric elastomer, the dielectric elastomer is contracted and expanded by Coulomb's force generated as a voltage is applied to the electroactive layer 112, so that the actuator 110 may vibrate. In addition, when the electroactive layer 112 is made of a ferroelectric polymer, as a voltage is applied to the electroactive layer 112, the alignment direction of dipoles inside the electroactive layer 112 is changed so that the actuator 110 can vibrate. there is.
The plurality of electrodes 114 are electrodes for applying a voltage to the electroactive layer 112 and are made of a conductive material. In addition, in order to secure the transmittance of the actuator 110 , the plurality of electrodes 114 may be made of a transparent conductive material. For example, the plurality of electrodes 114 may be formed of a transparent conductive material such as indium tin oxide (ITO), PEDOT:PSS, silver-nanowire (AgNW), or the like. However, the constituent materials of the plurality of electrodes 114 are not limited to the above-described examples, and various transparent conductive materials and composites thereof may be used as constituent materials of the plurality of electrodes 114 . In addition, the plurality of electrodes 114 may have a thickness of 400 to 900 Å.
Referring to FIG. 3 , the plurality of electrodes 114 includes a first electrode 114a and a second electrode 114b. The first electrode 114a and the second electrode 114b are disposed adjacent to each other on the lower surface of the electroactive layer 112 . Each of the first electrode 114a and the second electrode 114b is connected to a wiring 116 extending to one end of the actuator 110 . The wiring 116 may be connected to the flexible printed circuit board through, for example, a pad disposed at one end of the actuator 110 , and the flexible circuit board may be electrically connected to the driving unit of the actuator 110 .
A planar area of each of the plurality of electrodes 114 is equal to or greater than a unit area in which a tactile sense is perceived. A unit area in which tactile sensations are perceived is a minimum unit area capable of transmitting tactile feedback to a user, and each unit area in which tactile sensations are perceived may independently transmit tactile feedback.
The unit area in which each tactile sense is recognized may be determined in consideration of the size of a general human finger or a handwriting input means. Since the actuator 110 transmits tactile feedback for a touch input of a finger or a handwriting input means, the unit area in which a tactile sense capable of delivering tactile feedback to the user is recognized may be determined in consideration of the area in which the user's touch input occurs. there is.
In some embodiments, an area of each of the plurality of electrodes 114 may be determined in consideration of an area of a pixel of a touch sensing unit that may be used together with the actuator 110 . In response to the touch sensing unit detecting the user's touch input, the actuator 110 transmits tactile feedback to the user. Accordingly, for example, when the area of each of the plurality of electrodes 114 of the actuator 110 is determined to be the same as the pixel of the touch sensing unit in which the user's touch input is sensed, the pixel of the touch sensing unit and the electrode of the actuator 110 are determined. Since 114 may correspond to 1:1, the position of providing the vibration or texture of the actuator 110 may be more accurately determined.
4A is a schematic cross-sectional view illustrating driving of a display device and tactile sensation felt by a user according to an exemplary embodiment of the present invention. 4B is a schematic diagram illustrating driving of a display device according to an exemplary embodiment. 4C is a schematic diagram illustrating an example of driving a display device according to an exemplary embodiment. In FIG. 4A , the touch sensing unit 130 and the display unit 150 are omitted from the display device 100 for convenience of description. Since the actuator 110 of the display device 100 illustrated in FIG. 4A is substantially the same as the actuator 110 illustrated in FIG. 3 , a redundant description of the structure thereof will be omitted. In the drawings below, the + symbol indicates that a driving voltage is applied to the electrode, and the - symbol indicates that 0 V is applied to the electrode or the electrode is grounded.
Referring to FIG. 4A , a first voltage, for example, a driving voltage, is applied to the first electrode 114a, and a second voltage, for example, a 0 V voltage, is applied to the second electrode 114b adjacent to the first electrode 114a. grounded Accordingly, an electric field is formed in the electroactive layer 112 between the first electrode 114a and the second electrode 114b. When the electroactive layer 112 is made of a dielectric elastomer, the dielectric elastomer contracts and expands so that the actuator 110 vibrates. Alternatively, when the electroactive layer 112 is made of a ferroelectric polymer, the alignment direction of the dipoles inside the electroactive layer 112 is changed so that the actuator 110 vibrates. Vibration from the actuator 110 is transmitted to the upper cover 180 , and the user perceives the vibration through a mechanical stimulus receptor of a finger in contact with the upper cover 180 . In addition, voltages of different frequencies may be applied to provide various senses of vibration. In order to provide various senses of vibration, the frequency of the voltage applied to the plurality of electrodes may be, for example, in the range of 1 to 500 Hz.
A first voltage and a second voltage or voltages of different potentials may be applied to each of the plurality of electrodes 114 including the first electrode 114a and the second electrode 114b, and a plurality of adjacent electrodes 114 may be applied. ), the oscillation is generated by the potential difference at Referring to FIG. 4B , voltages applied to the plurality of electrodes 114 by the actuator 110 of the display device 100 according to an exemplary embodiment are illustrated. As shown in FIG. 4B , the first voltage and the second voltage are applied to the plurality of electrodes 114 of the actuator 110 to cross each other, thereby providing a sense of vibration to the user. In addition, a voltage may be applied to only a portion of an adjacent electrode among the plurality of electrodes 114 to provide a local sense of vibration.
Referring to FIG. 4C , the display unit 150 of the display device 100 and a screen displayed by the display unit 150 are illustrated according to an exemplary embodiment of the present invention. A plurality of cards are spread out on the screen, and when the user selects one of the plurality of cards with a finger, a local vibration is transmitted through the finger. Since selecting one of the plurality of cards does not involve movement of a finger in a plane, the display device 100 transmits a tactile feedback as a sense of vibration through driving of the actuator 110 in FIGS. 4A and 4B .
On the other hand, in the display device 100 according to an embodiment of the present invention, in addition to the sense of vibration, the texture of the displayed object may also be provided through the same actuator 110 . The texture of the object may be implemented by driving the actuator 110 differently from FIGS. 4A and 4B . Hereinafter, a driving method for realizing the texture of the object in the same actuator 110 will be described.
5A is a schematic cross-sectional view illustrating driving of a display device and a tactile sense felt by a user according to an exemplary embodiment of the present invention. 5b is a schematic diagram for explaining driving of a display device according to an exemplary embodiment. 5C is a schematic diagram illustrating an example of driving a display device according to an exemplary embodiment. In FIG. 5A , the touch sensing unit 130 and the display unit 150 are omitted from the display device 100 for convenience of description. Since the actuator 110 of the display device 100 illustrated in FIG. 5A is substantially the same as the actuator 110 illustrated in FIG. 3 , a redundant description of the structure thereof will be omitted.
Referring to FIG. 5A , a first voltage is applied to both the first electrode 114a and the second electrode 114b. Accordingly, an electric field is formed between the plurality of electrodes 114 and the fingers, horizontal friction is generated by the movement of the fingers in a plane, and the user creates friction between the first electrode 114a and the second electrode 114b. You can recognize the texture through it.
As described above, the first voltage or the second voltage may be applied to all of the plurality of electrodes 114 including the first electrode 114a and the second electrode 114b. Referring to FIG. 5B , voltages applied to the plurality of electrodes 114 by the actuator 110 of the display device 100 according to an exemplary embodiment are illustrated. As shown in FIG. 5B , when the same first voltage is applied to all of the plurality of electrodes 114 of the actuator 110 , when the user's finger moves on a plane, a texture may be provided. Referring to FIG. 5C , the display unit 150 of the display device 100 and a screen displayed by the display unit 150 are illustrated according to an embodiment of the present invention. The screen displays products from the online shopping mall. The same first voltage is applied to the plurality of electrodes 114 corresponding to the area SP where products are displayed. Accordingly, when the finger moves on the area SP where the products are displayed, the texture of the product is transmitted through the finger. In addition, voltages of different frequencies may be applied to each of the areas SP where products are displayed, so that various textures such as smoothness to roughness may be provided. The frequency of the voltage applied to the plurality of electrodes 114 to provide a texture may be, for example, in the range of 1 to 1000 Hz.
Since the texture of the product accompanies the movement of the finger in a plane and does not require a sense of vibration for input, the display device can deliver tactile feedback with the texture through driving the actuator 110 in FIGS. 5A and 5B and the horizontal friction of the finger. there is.
6 is a schematic diagram for explaining driving conversion of a display device according to an exemplary embodiment. Referring to FIG. 6 , a plurality of cards are spread out on the display unit 150 , and in this case, the actuator 110 has a first voltage applied to the first electrode 114a of the plurality of electrodes 114 as shown in FIG. 4B and a second electrode. A second voltage is applied to 114b to cross each other. When the user selects one of the plurality of cards, a local vibration is transmitted through the finger.
Next, the screen of the display unit 150 is switched to display products in the online shopping mall. In this case, the first voltage is applied to both the first electrode 114a and the second electrode 114b, which are the plurality of electrodes 114 as shown in FIG. 5B , to the actuator 110 . Accordingly, when the user's finger moves on the area SP where products are displayed, the texture of the product is transmitted through the finger.
That is, by changing the voltage applied to the second electrode 114b from the second voltage to the same first voltage applied to the first electrode 114a, the potential difference between the first electrode 114a and the second electrode 114b The electric field generated by the ? is dissipated, and an electric field is formed between the user's finger and the first electrode 114a and the second electrode 114b. Accordingly, in the display device 100 according to an exemplary embodiment of the present invention, the sense of vibration and the texture of an object may be switched according to the driving by one actuator 110 and provided. In addition, since two different haptic sensations may be implemented in one actuator 110 , the manufacturing process may be simplified and thus the process cost may also be reduced.
An actuator of a display device according to an embodiment of the present invention was manufactured and operation was checked. As the electroactive layer, a polydimethyl siloxane electroactive polymer film having a thickness of 190 μm and a transmittance of 89% was used. As a plurality of electrodes, ITO was formed under the electroactive layer by sputtering to have a sheet resistance of 182 Ω/□ and a thickness of 900 Å. Next, a sine wave having a frequency of 500 to 1000 V and 100 Hz was used as the driving voltage. Vibration sensation was measured as vibration acceleration. As shown in FIGS. 4A and 4B , when 0 V and a driving voltage were applied to each of a plurality of adjacent electrodes, a vibration acceleration of 0.15 G was measured. As shown in FIGS. 5A and 5B , when a driving voltage was applied to all of the plurality of adjacent electrodes, when the finger was moved, the texture due to frictional force was recognized.
Hereinafter, structures of an actuator and a plurality of electrodes of a display device according to various embodiments will be described. 7A is a schematic plan view illustrating an actuator of a display device according to another exemplary embodiment. 7B is a schematic enlarged plan view illustrating an actuator of a display device according to other exemplary embodiments. Referring to FIG. 7A , the actuator 710 includes an electroactive layer 712 , a cell (CE) in which the first electrode 714a and the second electrode 714b are disposed, a first wire 716 , and a second wire 718 and FPCB 720;
The electroactive layer 712 is configured to have an active area AA. The active area AA of the electroactive layer 712 is an area for transmitting tactile feedback to a user, and includes a plurality of cells CE in which the first electrode 714a and the second electrode 714b are disposed. Hereinafter, for a more detailed description of each cell CE and the first electrode 714a and the second electrode 714b disposed in the cell CE, FIG. 7B is also referred to.
Referring to FIG. 7B , the first electrode 714a and the second electrode 714b are disposed on one surface of the electroactive layer 712 in one cell CE. That is, the first electrode 714a and the second electrode 714b are formed on the same surface of the electroactive layer 712 , and both the first electrode 714a and the second electrode 714b are formed in one cell CE. are placed
Referring to FIG. 7B , each of the first electrode 714a and the second electrode 714b includes a stem electrode and a plurality of branch electrodes extending from the stem electrode. Specifically, the first electrode 714a includes a stem electrode extending in a horizontal direction from the upper region of the cell CE and a plurality of branch electrodes extending in a vertical direction from the stem electrode. In addition, the second electrode 714b includes a stem electrode extending in a horizontal direction from the lower region of the cell CE and a plurality of branch electrodes extending in a vertical direction from the stem electrode. Referring to FIG. 7B , the plurality of branch electrodes of the first electrode 714a and the plurality of branch electrodes of the second electrode 714b are alternately arranged in the cell CE. In other words, the branch electrode of the second electrode 714b is disposed between the branch electrodes of the first electrode 714a, and the branch electrode of the first electrode 714a is disposed between the branch electrodes of the second electrode 714b. are placed In the actuator 710 of the display device 700 according to another embodiment of the present invention, as the plurality of branch electrodes of the first electrode 714a and the plurality of branch electrodes of the second electrode 714b are alternately arranged with each other, the The portion adjacent to the first electrode 714a and the second electrode 714b may be increased, and accordingly, when a voltage is applied to the first electrode 714a and the second electrode 714b, the electric field applied to the electroactive layer 712 may increase in size.
Referring back to FIG. 7A , the first wiring 716 and the second wiring 718 are electrically connected to each of the first electrode 714a and the second electrode 714b in the plurality of cells CE in an electroactive layer ( 712). Specifically, the first wiring 716 is electrically connected to the first electrode 714a in the plurality of cells CE, and the second wiring 718 is connected to the second electrode 714b in the plurality of cells CE. electrically connected. The first wiring 716 and the second wiring 718 may be formed of the same material as the first electrode 714a and the second electrode 714b or may be formed of a different material. When the first wiring 716 and the second wiring 718 are made of the same material as the first electrode 714a and the second electrode 714b, the first wiring 716 and the second wiring 718 are formed of the first The electrode 714a and the second electrode 714b may be simultaneously formed in the same process.
A flexible printed circuit board (FPCB) 720 is disposed on one side of the electroactive layer 712 . The FPCB 720 is electrically connected to the first wire 716 and the second wire 718 , and the FPCB 720 has a first electrode 714a through the first wire 716 and the second wire 718 . and a circuit unit such as an actuator driver 720 for applying a voltage to the second electrode 714b may be built-in. Although it is illustrated in FIG. 1A that a circuit unit such as the driving unit 720 is embedded in the FPCB 720, the present invention is not limited thereto, and the circuit unit may be implemented in a method such as a chip on flim (COF).
8 to 10 are schematic enlarged plan views for explaining an actuator of a display device according to various embodiments of the present disclosure. 8 and 9 illustrate only the first electrodes 814a and 914a and the second electrodes 814b and 914b disposed in one cell CE of each of the actuators of the display devices 800 and 900, and FIG. 10 shows The first electrode 1014a and the second electrode 1014b disposed in the active area AA of the electroactive layer 912 of the actuator are shown. The actuators of the display devices 800 , 900 , and 1000 shown in FIGS. 8 to 10 are different from the actuators shown in FIG. 3 or 7B only in the shapes of the first electrode 114a and the second electrode 114b. However, since other components are substantially the same, redundant description is omitted.
First, referring to FIGS. 8 and 9 , the first electrodes 814a and 914a and the second electrodes 814b and 914b are portions in which the first electrodes 814a and 914a and the second electrodes 814b and 914b are adjacent to each other. It can have a structure to maximize . For example, as shown in FIG. 8 , the first electrode 814a and the second electrode 814b may be disposed to have a spiral structure, and as shown in FIG. 9 , the first electrode 914a and the second electrode 914b may be disposed to have a double loop structure. However, the shapes of the first electrodes 814a and 914a and the second electrodes 814b and 914b are not limited to the examples shown in FIGS. 8 and 9 .
Next, referring to FIG. 10 , the first electrode 1014a and the second electrode 1014b may be disposed over the entire active area AA of the electroactive layer 1012 . For example, as shown in FIG. 10 , each of the plurality of first electrodes 1014a extends in the horizontal direction in the active area AA of the electroactive layer 1012 , and each of the plurality of second electrodes 1014b is electrically It may extend in the vertical direction in the active area AA of the active layer 1012 . At this time, in order to electrically insulate the first electrode 1014a and the second electrode 1014b, at least the first electrode 1014a and the second electrode 1014b intersect at the point where the first electrode 1014a and the second electrode 1014b intersect. A separate insulating layer or a planarization layer may be disposed between the electrodes 1014b. In FIG. 10 , for convenience of explanation, the first electrode 1014a and the second electrode 1014b are illustrated as being arranged in a rhombus shape, but the present invention is not limited thereto.
11 is a flowchart illustrating a method of driving a display device according to another exemplary embodiment. First, a first electrode and a second electrode disposed adjacent to the first electrode are provided on one surface of the electroactive layer (S1110).
Next, it is determined whether a sense of vibration is required (S1120). For example, if the displayed screen is an electronic keyboard that requires a sense of vibration, a screen that receives a call or text, or a screen that requires input feedback, a sense of vibration may be required. When a sense of vibration is required, an actuator of the display device may be driven to provide a sense of vibration.
In order to provide a sense of vibration through the electroactive layer, a first voltage is applied to the first electrode and a second voltage is applied to the second electrode ( S1130 ). For example, the driving voltage may be applied to the first electrode and the second electrode may be grounded or a voltage of 0 V may be applied. Accordingly, the electroactive layer contracts and expands to provide a sense of vibration. After the sense of vibration is provided, step S1120 is repeated again.
When it is determined that the sense of vibration is not required, it is determined whether a sense of texture is required for the object (S1140). For example, when a displayed screen includes an object requiring a texture, scrolls a page, or takes electronic notes, the texture may be requested. When a texture is required, an actuator of the display device is driven to provide the texture.
In order to provide a texture, a first voltage is applied to both the first electrode and the second electrode ( S1150 ). Accordingly, when the finger moves in contact with the display device, the tactile sense is transmitted to the finger by electric horizontal friction generated. After the texture is provided, step S1120 is repeated again. Even if the texture is not required, step S1120 is repeated again. However, the method for driving the display device shown in FIG. 11 is only exemplary, and if the display device can switchably provide vibration and texture, the present invention is not limited thereto. Various algorithms can provide vibration and texture in any situation. It may be determined whether this is required, and the precedence and precedence of the judgment or the judgment method may be different.
12 is a diagram illustrating examples in which a display device according to various embodiments of the present disclosure may be advantageously utilized. 12A illustrates a case in which a display apparatus according to an embodiment of the present invention is used in a mobile device 1200 . A display device according to an embodiment of the present invention is illustrated to be included in the mobile device 1200 in FIG. 12A , wherein the mobile device 1200 includes a miniaturized device such as a smart phone, a mobile phone, a tablet PC, a PDA, etc. it means. When the display device 1210 is installed in the mobile device 1200 , external power is not supplied and its own battery is used. Therefore, components of the display device 1210 must be designed to fit a limited battery capacity. The driving voltage of the actuator of the display device 1210 may be reduced, and the display device 1210 may be normally driven even with a limited battery capacity. In addition, since the user may feel vibration along with touch when watching a video, playing a game, or inputting a button with the mobile device 1200 , more sensuous information may be transmitted.
12B illustrates a case in which the display device according to an embodiment of the present invention is used in the vehicle navigation system 1300 . The vehicle navigation device 1300 may include a display device 1310 and a plurality of manipulation elements, and may be controlled by a processor installed inside the vehicle. When the display device 1310 is applied to the vehicle navigation system 1300, the height of the road, the state of the road, the virtual jog shuttle, and the progress of the vehicle can be provided by tactile sense by texture, and a virtual button is input on the navigation screen. It is possible to provide different button sensations by vibration when doing so, helping to secure driver safety and visibility.
12C illustrates a case in which a display device according to an embodiment of the present invention is used as a display unit 1400 such as a monitor or TV. When the display device 1410 according to an embodiment of the present invention is used as the display means 1400, the user can tactilely feel the texture of a specific object, the speaker's state, etc. You can enjoy the video.
12D illustrates a case in which the display device according to an embodiment of the present invention is used in an outdoor billboard 1500 . The outdoor billboard 1500 may include a display device 1510 and a support connecting the ground to the display device 1510 . When the display device 1510 according to an embodiment of the present invention is applied to the outdoor billboard 1500, tactile information about the advertisement item to be sold can be directly transmitted to the user along with the image and/or sound, so that the advertisement effect can be maximized.
12E illustrates a case in which a display device according to various embodiments of the present disclosure is used in a game machine 1600 . The game machine 1600 may include a display device 1610 and a housing in which various processors are embedded. When the display device 1610 according to an embodiment of the present invention is applied to the game machine 1600, various tactile feedbacks according to the user's game manipulation can be provided in a realistic way, thereby increasing the user's immersion in the game. can be doubled.
12(f) illustrates a case in which the display device according to an embodiment of the present invention is used in the electronic blackboard 1700. Referring to FIG. The electronic blackboard 1700 may include a display device 1710 , a speaker, and a structure for protecting them from external impact. When the display device 1710 according to an embodiment of the present invention is applied to the electronic blackboard 1700, the educator feels like writing directly on the blackboard when inputting lecture contents into the display device 1710 with a stylus pen or a finger. can be provided. In addition, when the trainee applies a touch input to the image displayed on the electronic blackboard 1700 , tactile feedback suitable for the image can be provided to the trainee, so that the effect of education can be maximized.
The steps of a method or algorithm described in connection with the embodiments disclosed herein may be directly implemented in hardware, software module executed by a processor, or a combination of the two. A software module may reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor, the processor capable of reading information from, and writing information to, the storage medium. Alternatively, the storage medium may be integral with the processor. The processor and storage medium may reside within an application specific integrated circuit (ASIC). The ASIC may reside within the user terminal. Alternatively, the processor and storage medium may reside as separate components within the user terminal.
Although the present invention has been described in more detail with reference to examples above, the present invention is not necessarily limited to these examples, and various modifications may be made within the scope without departing from the technical spirit of the present invention. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical spirit of the present invention, but to explain, and the scope of the technical spirit of the present invention is not limited by these embodiments. The protection scope of the present invention should be construed by the following claims, and all technical ideas within the scope equivalent thereto should be construed as being included in the scope of the present invention.

100, 700, 800, 900, 1000: display device
110: actuator
112, 712, 812, 912, 1010: electroactive layer
114, 714, 814, 914, 1014: a plurality of electrodes
114a, 714a, 814a, 914a, 1014a: first electrode
114b, 714b, 814b, 914b, 1014b: second electrode
116, 716, 718: wiring
120, 720: actuator drive unit
130: touch sensing unit
140: touch circuit unit
150: display
160: timing control
170: processor
180: top cover
190: lower cover
720: FPCB
1200: mobile device
1300: car navigation
1400: display means
1500: outdoor billboard
1600: game console
1700: electronic blackboard

Claims (9)

providing a contact-sensitive device comprising an electroactive layer made of an electroactive polymer, and a first electrode disposed only on one surface of the electroactive layer and a second electrode disposed adjacent to the first electrode;
applying different voltages to each of the first electrode and the second electrode so that the touch sensitive element vibrates; and
and applying the same voltage to both the first electrode and the second electrode to generate horizontal friction over the touch-sensitive element. According to claim 1,
and the horizontal friction is generated by a planar movement of a finger over the touch-sensitive element. According to claim 1,
The step of applying different voltages to each of the first electrode and the second electrode or the step of applying the same voltage to both the first electrode and the second electrode is performed only in a partial region of the touch sensitive element. device driving method. According to claim 1,
The step of applying different voltages to each of the first electrode and the second electrode and the step of applying the same voltage to both the first electrode and the second electrode are implemented to be switchable. According to claim 1,
The electroactive layer has a plurality of cells,
and the first electrode and the second electrode are disposed in each of the cells. 6. The method of claim 5,
each of the first electrode and the second electrode has a first sub-electrode and a plurality of second sub-electrodes extending from the first sub-electrode;
and the second sub-electrode of the first electrode and the second sub-electrode of the second electrode are alternately disposed. According to claim 1,
and each of the first electrode and the second electrode has a spiral structure or a double loop structure. According to claim 1,
The step of applying different voltages to each of the first electrode and the second electrode so that the touch sensitive element vibrates may include applying a driving voltage to the first electrode and grounding the second electrode or a voltage of 0V. A method of driving a touch sensitive element, comprising the step of applying 9. The method of claim 8,
Applying the same voltage to both the first electrode and the second electrode to generate horizontal friction on the touch sensitive element includes applying the driving voltage to both the first electrode and the second electrode A method for driving a touch sensitive element.

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