Haptic actuator

Abstract

A haptic actuator according to various embodiments of the present invention may amplify vibration caused by driving of a piezoelectric element and transmit the amplified vibration to a cover glass covering a display panel, through an amplification member including: a head to which the piezoelectric element is attached; a first support which has a width less than the width of the head and stands upright at the center of the head; and a second support at the center of which the first support stands upright and which has a width greater than the width of the first support and is attached to the rear surface of the cover glass.

Description

Haptic actuator

[0001] The present invention relates to a haptic actuator having an amplification member for amplifying vibrations caused by the driving of a piezoelectric element and transmitting them to a cover glass covering a display panel.

[0002] As computer-based systems advance, the ease of human-machine interfaces is becoming increasingly important. Human-machine interfaces must be intuitive and easy to use for anyone. Among interface devices, touch screens or touchpads are the most intuitive and easy to use.

[0003] A touch screen consists of a panel capable of tactile sensing and a display device. Generally, the position and function of a pointer within the touch screen can be manipulated by directly touching the screen from the outside.

[0004] Meanwhile, the development of haptic feedback generators is actively underway to provide haptic feedback to touch screens. Here, haptic refers to a tactile sensation that can be felt by a person's fingertips when touching an object, and it is a concept that encompasses tactile feedback, which is felt when the skin touches the surface of an object, and kinesthetic force feedback, which is felt when the movement of joints and muscles is hindered.

[0005] In particular, vibration effects, or vibrating haptic effects, can be useful for alerting users to specific events or providing realistic feedback to create greater sensory immersion within a simulated or virtual environment.

[0006] A piezoelectric element is a component applied to haptic technology to provide haptic feedback to users. A piezoelectric element is a device that implements the piezoelectric effect, which generates voltage when mechanical deformation is applied externally, or generates vibration while expanding or contracting when voltage is applied.

[0007] However, since there is a limit to the vibration that can occur depending on the material, shape, or magnitude of the applied voltage of the piezoelectric element, a means is required to efficiently generate larger vibrations.

[0008] The present invention relates to a haptic actuator, and more specifically, aims to provide a haptic actuator having an amplification member for amplifying vibrations caused by the driving of a piezoelectric element and transmitting them to a cover glass covering a display panel.

[0009] In addition, the purpose is to provide a haptic actuator that can amplify vibrations transmitted vertically to the back surface of the cover glass through an amplification member, while simultaneously stably positioning the amplification member.

[0010] The problems to be solved by the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art to which the present invention belongs from the description below.

[0011] A haptic actuator located on the back surface of a cover glass covering a display panel comprises: a piezoelectric element driven to generate vibration; and an amplification member attached to the back surface of the piezoelectric element and amplifying the vibration caused by the driving of the piezoelectric element and transmitting it to the cover glass, wherein the amplification member comprises: a head to which the piezoelectric element is attached; a first support formed with a width smaller than the width of the head and standing upright at the center of the head; and a second support formed with a width larger than the width of the first support and attached to the back surface of the cover glass, wherein the first support stands upright at the center.

[0012] The width of the first support may be less than or equal to half the wavelength of the vibration generated by the piezoelectric element.

[0013] The width of the piezoelectric element is the same as the width of the head, and the width of the first support may be 1 / 10 or more of the width of the piezoelectric element.

[0014] The width of the head may be less than or equal to the vertical distance between the edge of the display panel and the edge of the cover glass.

[0015] The width of the second support can be formed to be smaller than the width of the head.

[0016] The thickness of each of the head, the first support, and the second support may be 0.5 millimeters or more and less than half the wavelength of the vibration generated by the piezoelectric element.

[0017] The thickness of the second support may be formed to be smaller than the thickness of the head or the first support.

[0018] The amplification member is formed by extending in the longitudinal direction, and a plurality of them may be attached to the back edge of the cover glass, spaced apart from the display panel.

[0019] A plurality of the above-mentioned piezoelectric elements can be attached to the head at spaced intervals.

[0020] The above amplification member may include a metal material or a plastic material.

[0021] It may further include an adhesive member for attaching the piezoelectric element to the head and attaching the second support to the back surface of the cover glass.

[0022] The above display panel includes a flexible display panel, the cover glass is bent to have a predetermined radius of curvature, and the second support can be bent to have the same radius of curvature as the cover glass.

[0023] The above display panel may include an LCD (Liquid Crystal Display) panel.

[0024] The haptic actuator according to the present invention may have an amplification member for amplifying vibrations caused by driving a piezoelectric element and transmitting them to a cover glass covering a display panel.

[0025] In addition, vibrations transmitted vertically to the back surface of the cover glass can be amplified through the amplification member, and at the same time, the amplification member can be stably positioned on the cover glass.

[0026] The effects obtainable from the present invention are not limited to those mentioned above, and other unmentioned effects will be clearly understood by those skilled in the art from the description below.

[0027] Figure 1 is a block diagram illustrating each configuration of a display device.

[0028] FIG. 2 is a drawing illustrating a haptic actuator located on the back surface of a cover glass according to one embodiment of the present invention.

[0029] Figure 3 is a cross-sectional view of AA of Figure 2.

[0030] FIG. 4 is an exploded view of a haptic actuator according to one embodiment of the present invention.

[0031] FIG. 5 is a perspective view of a haptic actuator according to one embodiment of the present invention.

[0032] FIG. 6 is a diagram illustrating the effect of a haptic actuator according to one embodiment of the present invention.

[0033] Hereinafter, embodiments disclosed in this specification will be described in detail with reference to the attached drawings. Identical or similar components regardless of drawing symbols will be assigned the same reference number, and redundant descriptions thereof will be omitted. The suffixes "module" and "part" used for components in the following description are assigned or used interchangeably solely for the ease of drafting the specification and do not inherently possess distinct meanings or roles. Furthermore, in describing embodiments disclosed in this specification, if it is determined that a detailed description of related prior art could obscure the essence of the embodiments disclosed in this specification, such detailed description will be omitted. Additionally, the attached drawings are intended only to facilitate understanding of the embodiments disclosed in this specification; the technical concept disclosed in this specification is not limited by the attached drawings, and it should be understood that they include all modifications, equivalents, and substitutions that fall within the spirit and technical scope of the present invention.

[0034] Terms including ordinal numbers, such as first, second, etc., may be used to describe various components, but said components are not limited by said terms. These terms are used solely for the purpose of distinguishing one component from another.

[0035] When it is stated that one component is "connected" or "connected" to another component, it should be understood that while it may be directly connected or connected to that other component, there may also be other components in between. On the other hand, when it is stated that one component is "directly connected" or "directly connected" to another component, it should be understood that there are no other components in between.

[0036] A singular expression includes a plural expression unless the context clearly indicates otherwise.

[0037] In this application, terms such as “comprising” or “having” are intended to specify the existence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0038] Meanwhile, the display device described in this specification is, for example, an intelligent display device that adds computer support functions to broadcast reception functions. While faithful to broadcast reception functions, it also includes internet functions, and can be equipped with interfaces that are more convenient to use, such as a handwriting input device, a touch screen, or a spatial remote control. Furthermore, by supporting wired or wireless internet functions, it can be connected to the internet and computers to perform functions such as email, web browsing, banking, or games. A standardized general-purpose OS may be used for these various functions.

[0039] Accordingly, the display device described in the present invention allows various applications to be freely added or removed, for example, on a general-purpose OS kernel, thereby enabling various user-friendly functions to be performed. More specifically, the display device may be, for example, a network TV, HBBTV, a smart TV, etc., and may also be applicable to a smartphone depending on the circumstances.

[0040] FIG. 1 is a block diagram for explaining each configuration of a display device (100). The display device (100) may include a broadcast receiver (110), an external device interface unit (171), a network interface unit (172), a storage unit (140), a user input interface unit (173), an input unit (130), a control unit (180), a display module (150), an audio output unit (160), and / or a power supply unit (190).

[0041] The broadcast receiving unit (110) may include a tuner unit (111) and a demodulating unit (112).

[0042] Meanwhile, unlike the drawing, the display device (100) may include only the external device interface unit (171) and the network interface unit (172) among the broadcast receiver (110), the external device interface unit (171), and the network interface unit (172). That is, the display device (100) may not include the broadcast receiver (110).

[0043] The tuner unit (111) can select a broadcast signal corresponding to a channel selected by the user or all previously stored channels among the broadcast signals received through an antenna (not shown) or a cable (not shown). The tuner unit (111) can convert the selected broadcast signal into an intermediate frequency signal or a baseband video or audio signal.

[0044] For example, the tuner unit (111) can convert the selected broadcast signal into a digital IF signal (DIF) if it is a digital broadcast signal, and convert it into an analog baseband video or audio signal (CVBS / SIF) if it is an analog broadcast signal. That is, the tuner unit (111) can process a digital broadcast signal or an analog broadcast signal. The analog baseband video or audio signal (CVBS / SIF) output from the tuner unit (111) can be directly input to the control unit (180).

[0045] Meanwhile, the tuner unit (111) can sequentially select broadcast signals of all broadcast channels stored through a channel memory function among the received broadcast signals and convert them into intermediate frequency signals or baseband video or audio signals.

[0046] Meanwhile, the tuner unit (111) may be equipped with multiple tuners to receive multiple channels of broadcast signals. Alternatively, a single tuner that simultaneously receives multiple channels of broadcast signals is also possible.

[0047] The demodulator (112) can receive the digital IF signal (DIF) converted by the tuner (111) and perform a demodulation operation. The demodulator (112) can output a stream signal (TS) after performing demodulation and channel decoding. At this time, the stream signal may be a signal in which a video signal, an audio signal, or a data signal is multiplexed.

[0048] The stream signal output from the demodulation unit (112) can be input to the control unit (180). After performing demultiplexing, video / audio signal processing, etc., the control unit (180) can output video through the display module (150) and output audio through the audio output unit (160).

[0049] The sensing unit (120) refers to a device that detects changes within the display device (100) or detects external changes. For example, it may include at least one proximity sensor, illumination sensor, touch sensor, infrared sensor (IR sensor), ultrasonic sensor, optical sensor (e.g., camera), voice sensor (e.g., microphone), battery gauge, and environmental sensor (e.g., hygrometer, thermometer, etc.).

[0050] The control unit (180) can check the status of the display device (100) based on information collected from the sensing unit (120), and if a problem occurs, notify the user or control it to maintain the best state by self-adjusting.

[0051] In addition, the content, quality, size, etc. of the video provided to the display module (150) can be controlled differently according to the viewer detected by the sensing unit (120) or the ambient light level, thereby providing an optimal viewing environment. As smart TVs advance, the number of functions installed in the display device (100) increases, and the number of sensing units (120) also increases accordingly.

[0052] The input unit (130) may be provided on one side of the main body of the display device (100). For example, the input unit (130) may include a touch pad, a physical button, etc. The input unit (130) may receive various user commands related to the operation of the display device (100) and transmit a control signal corresponding to the input command to the control unit (180).

[0053] Recently, as the size of the bezel of the display device (100) decreases, there are many display devices (100) in which the physical button-shaped input part (130) exposed externally on the device itself is minimized. Instead, a minimum number of physical buttons are located on the back or side, and user input can be received through a remote control device (200) via a touchpad or a user input interface part (173) to be described later.

[0054] The storage unit (140) may store programs for each signal processing and control within the control unit (180), and may also store signal-processed video, audio, or data signals. For example, the storage unit (140) may store applications designed for the purpose of performing various tasks that can be processed by the control unit (180), and may selectively provide some of the stored applications upon request from the control unit (180).

[0055] The program, etc. stored in the storage unit (140) is not specifically limited as long as it can be executed by the control unit (180). The storage unit (140) may also perform the function of temporarily storing video, audio, or data signals received from an external device through the external device interface unit (171). The storage unit (140) may store information regarding a predetermined broadcast channel through a channel memory function such as a channel map.

[0056] Although the storage unit (140) of FIG. 1 is illustrated in an embodiment in which it is provided separately from the control unit (180), the scope of the present invention is not limited thereto, and the storage unit (140) may be included within the control unit (180).

[0057] The storage unit (140) may include at least one of volatile memory (e.g., DRAM, SRAM, SDRAM, etc.) or non-volatile memory (e.g., flash memory, hard disk drive (HDD), solid-state drive (SSD), etc.).

[0058] The display module (150) can generate a driving signal by converting a video signal, data signal, OSD signal, control signal processed by the control unit (180) or a video signal, data signal, control signal, etc. received from the interface unit (171).

[0059] The display module (150) can be a flexible display, and can also be a 3D display. The 3D display module (150) can be classified into a glasses-free type and a glasses type.

[0060] The display device (100) may include a display module (150) that occupies most of the front surface area and a case that packages the display module (150) while covering the back side of the display module (150).

[0061] Conventional LCDs, which were primarily used, received light through a backlight unit because the LCD itself has difficulty emitting light. A backlight unit is a device that supplies light from a light source uniformly to a liquid crystal located on the front. While thin LCDs could be realized as the backlight unit became thinner, it is difficult to implement the backlight unit using a flexible material, and when the backlight unit bends, it becomes difficult to supply light uniformly to the liquid crystal, resulting in a problem where the brightness of the screen changes.

[0062] On the other hand, in the case of LED (Light Emitting Diode) or OLED (Organic Light Emitting Diode), since the elements forming the pixels each emit light on their own, a backlight unit is not used, so it can be implemented to be flexible. In addition, since each element emits light on its own, it does not affect its own brightness even if the positional relationship with neighboring elements changes, so a flexible display module (150) can be implemented.

[0063] OLEDs made their debut in earnest in the mid-2010s and are rapidly replacing LCDs in the small and medium-sized display market. OLEDs are displays created using the self-luminous phenomenon where fluorescent organic compounds emit light when an electric current flows through them; they have a faster image response speed compared to LCDs, resulting in almost no ghosting when displaying videos.

[0064] OLEDs use three types of phosphor organic compounds, such as red, green, and blue, which have self-emissive functions. Since they are light-emitting display products that utilize the phenomenon where electrons injected from the cathode and anode combine with positively charged particles within the organic material to emit light on their own, they do not require a backlight that degrades color quality.

[0065] The display module (150) may include a coupling magnet, a first power supply, and a first signal module.

[0066] The side of the display module (150) that displays an image may be referred to as the front or front. When the display module (150) displays an image, the side where the image cannot be observed may be referred to as the rear or rear. Meanwhile, the display module (150) may be configured as a touch screen and may be used as an input device in addition to an output device.

[0067] The audio output unit (160) receives a voice-processed signal from the control unit (180) and outputs it as voice.

[0068] The interface section (170) serves as a passage for various types of external devices connected to the display device (100). The interface section may include not only a wired method of transmitting and receiving data through a cable but also a wireless method using an antenna.

[0069] The interface section (170) may include at least one of a wired / wireless headset port, an external charger port, a wired / wireless data port, a memory card port, a port for connecting a device equipped with an identification module, an audio I / O (Input / Output) port, a video I / O (Input / Output) port, and an earphone port.

[0070] As an example of a wireless method, the aforementioned broadcast receiver (110) may be included, and may include not only broadcast signals but also mobile communication signals, short-range communication signals, wireless internet signals, etc.

[0071] The external device interface unit (171) can transmit or receive data with a connected external device. To this end, the external device interface unit (171) may include an A / V input / output unit (not shown).

[0072] The external device interface section (171) can be connected wirelessly or via wired connection to external devices such as DVD (Digital Versatile Disk), Blu-ray, game console, camera, camcorder, computer (laptop), set-top box, etc., and can also perform input / output operations with external devices.

[0073] Additionally, the external device interface unit (171) can establish a communication network with various remote control devices (200) to receive control signals related to the operation of the display device (100) from the remote control device (200) or transmit data related to the operation of the display device (100) to the remote control device (200).

[0074] The external device interface unit (171) may include a wireless communication unit (not shown) for short-range wireless communication with other electronic devices. Through this wireless communication unit (not shown), the external device interface unit (171) can exchange data with an adjacent mobile terminal. In particular, the external device interface unit (171) can receive device information, information on an application being executed, an application image, etc. from a mobile terminal in mirroring mode.

[0075] The network interface unit (172) may provide an interface for connecting the display device (100) to a wired / wireless network including the Internet network. For example, the network interface unit (172) may receive content or data provided by the Internet or a content provider or network operator through the network. Meanwhile, the network interface unit (172) may include a communication module (not shown) for connecting to a wired / wireless network.

[0076] The external device interface section (171) and / or network interface section (172) may include a communication module for short-range communication such as Wi-Fi (Wireless Fidelity), Bluetooth, Bluetooth Low Energy (BLE), Zigbee, NFC (Near Field Communication), a communication module for cellular communication such as LTE (long-term evolution), LTE-A (LTE Advance), CDMA (code division multiple access), WCDMA (wideband CDMA), UMTS (universal mobile telecommunications system), WiBro (Wireless Broadband), etc.

[0077] The user input interface unit (173) can transmit a signal input by the user to the control unit (180) or transmit a signal from the control unit (180) to the user. For example, it can transmit / receive user input signals such as power on / off, channel selection, and screen settings from the remote control device (200), transmit user input signals input from local keys (not shown) such as power key, channel key, volume key, and setting value to the control unit (180), transmit user input signals input from a sensor unit (not shown) that senses user gestures to the control unit (180), or transmit a signal from the control unit (180) to the sensor unit.

[0078] The control unit (180) may include at least one processor and can control the overall operation of the display device (100) using the included processor. Here, the processor may be a general processor such as a CPU (central processing unit). Of course, the processor may be a dedicated device such as an ASIC or a processor based on other hardware.

[0079] The control unit (180) can demultiplex a stream input through the tuner unit (111), demodulator unit (112), external device interface unit (171), or network interface unit (172), or process the demultiplexed signals to generate and output a signal for video or audio output.

[0080] The image signal processed by the control unit (180) is input to the display module (150) and can be displayed as an image corresponding to the image signal. Additionally, the image signal processed by the control unit (180) may be input to an external output device through the external device interface unit (171).

[0081] The voice signal processed by the control unit (180) can be sound-outputted to the audio output unit (160). Additionally, the voice signal processed by the control unit (180) can be input to an external output device through the external device interface unit (171). Although not shown in FIG. 2, the control unit (180) may include a demultiplexer, an image processing unit, etc.

[0082] In addition, the control unit (180) can control the overall operation within the display device (100). For example, the control unit (180) can control the tuner unit (111) to control the selection (tuning) of a broadcast corresponding to a channel selected by the user or a previously stored channel.

[0083] Additionally, the control unit (180) can control the display device (100) by means of a user command or an internal program input through the user input interface unit (173). Meanwhile, the control unit (180) can control the display module (150) to display an image. At this time, the image displayed on the display module (150) may be a still image or a video, and may be a 2D image or a 3D image.

[0084] Meanwhile, the control unit (180) can make a predetermined 2D object appear within the image displayed on the display module (150). For example, the object may be at least one of a connected web screen (newspaper, magazine, etc.), an EPG (Electronic Program Guide), various menus, widgets, icons, still images, videos, and text.

[0085] Meanwhile, the control unit (180) can modulate and / or demodulate the signal using an Amplitude Shift Keying (ASK) method. Here, the Amplitude Shift Keying (ASK) method may refer to a method of modulating the signal by varying the amplitude of the carrier wave according to the data value, or restoring the analog signal to a digital data value according to the amplitude of the carrier wave.

[0086] For example, the control unit (180) can modulate the video signal using an amplitude shift keying (ASK) method and transmit it through a wireless communication module.

[0087] For example, the control unit (180) can demodulate and process the video signal received through the wireless communication module using an amplitude shift keying (ASK) method.

[0088] Through this, the display device (100) can easily transmit and receive signals with other adjacent video display devices without using a unique identifier such as a MAC address (Media Access Control Address) or a complex communication protocol such as TCP / IP.

[0089] Meanwhile, the display device (100) may further include a shooting unit (not shown). The shooting unit can photograph the user. The shooting unit may be implemented with one camera, but is not limited thereto, and may also be implemented with multiple cameras. Meanwhile, the shooting unit may be embedded in the display device (100) on the upper part of the display module (150) or may be placed separately. Image information captured by the shooting unit may be input to the control unit (180).

[0090] The control unit (180) can recognize the user's location based on the image captured by the capturing unit. For example, the control unit (180) can determine the distance (z-axis coordinate) between the user and the display device (100). Additionally, the control unit (180) can determine the x-axis coordinate and y-axis coordinate within the display module (150) corresponding to the user's location.

[0091] The control unit (180) can detect a user's gesture based on each of the images captured by the shooting unit or the signals detected by the sensor unit, or a combination thereof.

[0092] The power supply unit (190) can supply power throughout the display device (100). In particular, it can supply power to a control unit (180) which can be implemented in the form of a System On Chip (SOC), a display module (150) for image display, and an audio output unit (160) for audio output.

[0093] Specifically, the power supply unit (190) may be equipped with a converter (not shown) that converts AC power into DC power and a DC / DC converter (not shown) that converts the level of DC power.

[0094] Meanwhile, the power supply unit (190) receives power from an external source and distributes power to each component. The power supply unit (190) may use a method of supplying AC power by directly connecting to an external power source, and may include a power supply unit (190) that can be recharged and used by including a battery.

[0095] In the former case, it is used by connecting a wired cable, making movement difficult or limiting the range of motion. In the latter case, movement is free, but the weight increases by the amount of the battery, the volume becomes larger, and for charging, it must be directly connected to a power cable for a certain period of time or combined with a charging dock (not shown) that supplies power.

[0096] The charging dock can be connected to a display device through an externally exposed terminal, or the built-in battery can be charged by bringing it close using a wireless method.

[0097] The remote control device (200) can transmit user input to the user input interface unit (173). To this end, the remote control device (200) may use Bluetooth, RF (Radio Frequency) communication, infrared (Infrared Radiation) communication, UWB (Ultra-wideband), ZigBee, etc. Additionally, the remote control device (200) may receive video, audio, or data signals output from the user input interface unit (173) and display or output audio from the remote control device (200).

[0098] Meanwhile, the above-described display device (100) may be a digital broadcast receiver capable of receiving fixed or mobile digital broadcasts.

[0099] Meanwhile, the block diagram of the display device (100) shown in FIG. 1 is merely a block diagram for one embodiment of the present invention, and each component of the block diagram may be integrated, added, or omitted according to the specifications of the actual implemented display device (100).

[0100] That is, as needed, two or more components may be combined into a single component, or a single component may be subdivided into two or more components. In addition, the functions performed in each block are intended to explain embodiments of the present invention, and the specific operations or devices thereof do not limit the scope of the present invention.

[0101] FIG. 2 is a drawing illustrating a haptic actuator (200) located on the back surface of a cover glass (220) according to an embodiment of the present invention. FIG. 3 is a cross-sectional view AA of FIG. 2. FIG. 4 is an exploded view of a haptic actuator (200) according to an embodiment of the present invention. FIG. 5 is a perspective view of a haptic actuator (200) according to an embodiment of the present invention. FIG. 6 is a drawing for explaining the effect of a haptic actuator (200) according to an embodiment of the present invention.

[0102] Hereinafter, in describing a haptic actuator (200) according to one embodiment of the present invention, the left-right direction is described based on the x-axis direction, the up-down direction is described based on the y-axis direction, and the directions facing the front and back are described based on the z-axis direction.

[0103] A haptic actuator (200) according to one embodiment of the present invention may be located on the back surface of a cover glass (220) covering a display panel (210) and may include a piezoelectric element (230) and an amplification member (240).

[0104] The piezoelectric element (230) plays a role in driving to generate vibrations, and the piezoelectric element (230) may be attached to the back surface of the amplification member (240). The amplification member (240) may play a role in amplifying the vibrations caused by the driving of the piezoelectric element (230) and transmitting them to the cover glass (220). Here, the display panel (210) may include an LCD (Liquid Crystal Display) panel.

[0105] LCD (Liquid Crystal Display) panels receive light through a backlight unit because LCDs have difficulty emitting light on their own. A backlight unit is a device that uniformly supplies light from a light source to the liquid crystals located on the front. As the backlight unit becomes thinner, thin LCD panels can be realized.

[0106] Here, in the case of an LCD panel, a piezoelectric element (230) can be positioned on the bezel portion, that is, on the back edge of the cover glass (220), as shown in FIG. 2, in order to implement haptic feedback. This is because, since there is an air layer between the layers of the LCD panel, the vibration transmission efficiency may decrease when the piezoelectric element (230) is positioned on the back of the LCD panel.

[0107] Accordingly, as illustrated in FIGS. 2 and 5, in a haptic actuator (200) according to one embodiment of the present invention, an amplification member (240) is formed by extending in the longitudinal direction (x-axis direction), and a plurality of them can be attached to the rear edge of a cover glass (220) spaced apart from the rear surface of a display panel (210).

[0108] In addition, as described above, since the piezoelectric element (230) has a limit to the vibrations that can occur depending on the material, shape, or magnitude of the applied voltage, it is necessary to amplify the vibrations transmitted to the display panel (210) to enhance the haptic effect.

[0109] Referring to FIG. 3 and FIG. 4 together, in a haptic actuator (200) according to one embodiment of the present invention, the amplification member (240) may include a head (241), a first support (242), and a second support (243). A piezoelectric element (230) may be attached to the head (241). The first support (242) is formed with a width (w2) smaller than the width (w1) of the head (241) so that it can stand upright at the center of the head (241). Additionally, the second support (243) is formed with a width (w3) larger than the width (w2) of the first support (242) so that the first support (242) stands upright at the center, and can be attached to the back surface of a cover glass (220).

[0110] Accordingly, in a haptic actuator (200) according to one embodiment of the present invention, the amplifying member (240) can amplify vibrations transmitted in a vertical direction (z-axis direction) to a display panel (210) through a first support (242) that stands upright at the center of a head (241) to which a piezoelectric element (230) is attached. And through this, the haptic effect can be enhanced through vibrations transmitted in a horizontal direction (x-axis or y-axis direction) and a vertical direction (z-axis direction) to the display panel (210).

[0111] However, the width (w2) of the first support (242) described later must be formed smaller than the width (w1) of the head (241) for vibration amplification. Therefore, it may be disadvantageous for the first support (242), which acts as a vibration amplifier, to be attached to the back surface of the display panel (210).

[0112] Accordingly, in a haptic actuator (200) according to one embodiment of the present invention, the amplifying member (240) may include a second support (243) formed to be larger than the width (w2) of the first support (242) and attached to the back surface of the cover glass (220). That is, the amplifying member (240) can amplify the vibration generated from the piezoelectric element (230) through the first support (242) to enhance the haptic effect, while simultaneously increasing the adhesion force with which the amplifying member (240) is attached to the cover glass (220) through the second support (243).

[0113] In addition, in the haptic actuator (200) according to one embodiment of the present invention, the width (w2) of the first support (242) may be less than half the wavelength of the vibration generated by the piezoelectric element (230). As described above, the smaller the width (w2) of the first support (242) standing upright at the center of the head (241), the more advantageous it may be to amplify the vibration transmitted to the cover glass (220) in a vertical direction (z-axis direction).

[0114] Accordingly, a haptic actuator (200) according to one embodiment of the present invention may form a width (w2) of a first support (242) that is less than half the wavelength of the vibration generated by the piezoelectric element (230). For example, in order to generate a resonant frequency of about 60 kHz by driving the piezoelectric element (230), the width (w2) of the first support (242) may be formed to about 6 mm, which is the length of half the wavelength.

[0115] In addition, in a haptic actuator (200) according to one embodiment of the present invention, the width (w4) of the piezoelectric element (230) may be equal to the width (w1) of the head (241). At this time, the width (w2) of the first support (242) may be 1 / 10 or more of the width (w4) of the piezoelectric element (230). Here, the width (w1) of the head (241) may be less than or equal to the width corresponding to the bezel portion described above through FIG. 2, which is the vertical distance between the edge of the display panel (210) and the edge of the cover glass (220).

[0116] This is because the larger the width (w4) of the piezoelectric element (230), the more advantageous it is for transmitting vibrations. However, as described above, since the haptic actuator (200) according to one embodiment of the present invention is located in the bezel portion, the width (w1) of the head (241) may be formed to be less than or equal to the width of the bezel portion. Also, the width (w4) of the piezoelectric element (230) may be the same as the width (w1) of the head (241).

[0117] Additionally, while making the width (w2) of the first support (242) smaller is advantageous for amplifying and transmitting vibrations, it is disadvantageous for attaching to the back surface of the cover glass (220), so it is necessary to ensure the structural stability of the amplification member (240). Accordingly, in the haptic actuator (200) according to one embodiment of the present invention, the width (w2) of the first support (242) can be made to be at least 1 / 10 of the width (w4) of the piezoelectric element (230).

[0118] In addition, in a haptic actuator (200) according to one embodiment of the present invention, the width (w3) of the second support (243) may be formed to be smaller than the width (w1) of the head (241). That is, the width (w3) of the second support (243) may be formed to be larger than the width (w2) of the first support (242) and smaller than the width (w1) of the head (241).

[0119] This is to ensure that the amplification member (240) secures an attachment force to the cover glass (220), and at the same time, efficiently transmits the amplified vibration to the cover glass (220) through the amplification member (240).

[0120] Here, FIG. 6 is a drawing for explaining the effect through the amplification member (240) in a haptic actuator (200) according to one embodiment of the present invention, and is experimental data for explaining the effect due to the case where the width (w2) of the first support (242) is different and the presence or absence of the second support (243).

[0121] Reference 1 (Ref. 1) is a case where the width (w2) of the first support (242) is formed to be 4mm and the first support (242) is attached to the back surface of the cover glass (220). Reference 2 (Ref. 2) is a case where the width (w2) of the first support (242) is formed to be 2mm and the first support (242) is attached to the back surface of the cover glass (220). And the present invention is an embodiment in which the width (w2) of the first support (242) is formed to be 2mm and the second support (243) is formed to be 4mm and the second support (243) is attached to the back surface of the cover glass (220).

[0122] As a result of comparing the data of Reference 1 (Ref. 1) and Reference 2 (Ref. 2), it was confirmed that the smaller the width (w2) of the first support (242), the greater the amplitude of the vibration transmitted to the cover glass (220).

[0123] That is, as described above, it was confirmed that the vibration transmitted to the cover glass (220) in a vertical direction (z-axis direction) through the first support (242) standing upright on the cover glass (220) can be amplified to enhance the haptic effect.

[0124] In addition, as a result of comparing the data of Reference 2 (Ref. 2) and the present invention, it was confirmed that when the second support (243) is formed and attached to the back surface of the cover glass (220), the amplitude of the vibration transmitted to the cover glass (220) increases.

[0125] That is, it was confirmed that increasing the adhesion force attached to the cover glass (220) through the second support (243) can efficiently transmit the vibration amplified through the first support (242) to the cover glass (220). And through this, it was confirmed that the haptic effect can be improved.

[0126] In addition, in a haptic actuator (200) according to one embodiment of the present invention, the thickness (t1) of the head (241), the thickness (t2) of the first support (242), and the thickness (t3) of the second support (243) are each 0.5 millimeters or more and may be less than half the wavelength of the vibration generated by the piezoelectric element (230).

[0127] And this is to design a minimum thickness to ensure structural stability of the amplification member (240). Also, since vibrations caused by the driving of the piezoelectric element (230) may be transmitted to and lost by the cover glass (220) if the amplification member (240) is too thick, this is to design a maximum thickness to allow the amplified vibrations to be transmitted to the cover glass (220).

[0128] Furthermore, in a haptic actuator (200) according to one embodiment of the present invention, the thickness (t3) of the second support (243) may be formed to be smaller than the thickness (t1) of the head (241) or the thickness (t2) of the first support (242). By forming the thickness (t3) of the second support (243) to be smaller, the thickness (t2) of the first support (242) may be formed to be relatively larger, thereby allowing the vibration transmitted to the cover glass (220) to be further amplified.

[0129] Referring again to FIG. 2 and FIG. 5 together, in a haptic actuator (200) according to one embodiment of the present invention, an amplification member (240) is formed by extending in the longitudinal direction (x-axis direction), and a plurality of them may be attached to the rear edge of a cover glass (220) spaced apart from the rear surface of a display panel (210). Here, a plurality of piezoelectric elements (230) may be attached to a head (241) spaced apart from each other. And the amplification member (240) can enhance the haptic effect by amplifying the vibration caused by the driving of a plurality of piezoelectric elements (230) and transmitting it to the cover glass (220).

[0130] Additionally, in a haptic actuator (200) according to one embodiment of the present invention, the amplifying member (240) may include a metal material or a plastic material. This is because the stiffness or elastic modulus of the amplifying member (240) is associated with the amplification of vibration.

[0131] That is, the greater the stiffness or elastic modulus of the amplification member (240), the more advantageous it may be to amplify the vibration. Therefore, as an embodiment of the present invention, the metal material may include an aluminum material with high stiffness. In addition, since the haptic actuator (200) according to an embodiment of the present invention can amplify the vibration generated from the piezoelectric element (230) through the amplification member (240), it may include not only metal or plastic materials, but also other materials with stiffness or elasticity.

[0132] And a haptic actuator (200) according to one embodiment of the present invention may further include an adhesive member (250) for attaching a piezoelectric element (230) to the head (241) of an amplification member (240) and attaching a second support (243) to the back surface of a cover glass (220).

[0133] Here, as an embodiment of the present invention, the stiffness of the adhesive member (250) to amplify vibration may be 3 GPa or more. Also, as an embodiment of the present invention, the adhesive member (250) may be applied between the piezoelectric element (230) and the head (241), and between the second support (243) and the back surface of the cover glass (220) with a thickness (t) of 100 micrometers or more and 250 micrometers or less.

[0134] In addition, the haptic actuator (200) according to one embodiment of the present invention can design the width (w3) or thickness (t3) of the second support (243) through specifications such as the hardness of the adhesive member (250), thereby improving the adhesion force attached to the cover glass (220) and efficiently transmitting amplified vibrations to the cover glass (220).

[0135] In addition, in the haptic actuator (200) according to one embodiment of the present invention, the display panel (210) may include a flexible display panel (210). And the cover glass (220) may be bent to have a predetermined radius of curvature. That is, the cover glass (220) may be formed in a shape corresponding to the flexible display panel (210) and may cover the flexible display panel (210).

[0136] In this case, the second support (243) of the amplification member (240) can be bent to have the same radius of curvature as the cover glass (220). That is, the haptic actuator (200) according to one embodiment of the present invention can improve the haptic effect by amplifying the vibration caused by the driving of the piezoelectric element (230) by forming the cover glass (220) and the second support (243) in correspondence with various shapes of the display panel (210).

[0137] To summarize the above, the haptic actuator according to the present invention may be provided with an amplification member for amplifying vibrations caused by the driving of a piezoelectric element and transmitting them to a cover glass covering a display panel. In addition, the vibrations transmitted in a vertical direction to the back surface of the cover glass through the amplification member can be amplified, and at the same time, the amplification member can be stably positioned on the cover glass.

[0138] The foregoing detailed description should not be interpreted restrictively in all respects and should be considered exemplary. The scope of the invention shall be determined by a reasonable interpretation of the appended claims, and all modifications within the equivalent scope of the invention are included within the scope of the invention.

Claims

1. A haptic actuator located on the back surface of a cover glass covering a display panel, A piezoelectric element driven to generate vibration; and The above-mentioned piezoelectric element is attached to the back surface, and includes an amplification member that amplifies vibrations caused by the driving of the above-mentioned piezoelectric element and transmits them to the cover glass. The above-mentioned amplification member is, A head to which the above-mentioned piezoelectric element is attached; A first support formed with a width smaller than the width of the head and standing upright at the center of the head; and A haptic actuator comprising a first support that stands upright at the center and a second support formed with a width greater than the width of the first support and attached to the back surface of the cover glass.

2. In Paragraph 1, The width of the first support above is, A haptic actuator characterized by having a vibration of less than half a wavelength generated by the above-mentioned piezoelectric element.

3. In Paragraph 1, The width of the above piezoelectric element is, The width of the head is the same as the above, and The width of the first support above is, A haptic actuator characterized by having a width of at least 1 / 10 of the width of the piezoelectric element.

4. In Paragraph 3, The width of the head above is, A haptic actuator characterized by being less than or equal to the vertical distance between the edge of the display panel and the edge of the cover glass.

5. In Paragraph 1, The width of the second support above is, A haptic actuator characterized by being formed smaller than the width of the head.

6. In Paragraph 1, The thickness of each of the head, the first support, and the second support is, A haptic actuator characterized by being 0.5 millimeters or more and having a wavelength less than or equal to half the wavelength of the vibration generated by the piezoelectric element.

7. In Paragraph 6, The thickness of the second support above is, A haptic actuator characterized by being formed to be smaller than the thickness of the head or the first support.

8. In Paragraph 1, The above-mentioned amplification member is, A haptic actuator characterized by being formed by extending in the longitudinal direction, with a plurality of them attached to the back edge of the cover glass, spaced apart from the display panel.

9. In Paragraph 8, The above piezoelectric element is, A haptic actuator characterized by having multiple units spaced apart from each other and attached to the head.

10. In Paragraph 1, The above-mentioned amplification member is, A haptic actuator characterized by including a metal material or a plastic material.

11. In Paragraph 1, A haptic actuator characterized by further including an adhesive member for attaching the piezoelectric element to the head and attaching the second support to the back surface of the cover glass.

12. In Paragraph 1, The above display panel is, It includes a flexible display panel, The above cover glass is, It is bent to have a predetermined radius of curvature, The above second support is, A haptic actuator characterized by being bent to have the same radius of curvature as the cover glass.

13. In Paragraph 1, The above display panel is, A haptic actuator characterized by including an LCD (Liquid Crystal Display) panel.

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