Display device and electronic device integrating sound

Abstract

This disclosure relates to a display device and electronic device integrating sound, and provides a display device and electronic device integrating sound, comprising: an excitation unit including a plurality of independently operating exciters; a display unit configured to visually display information and generate sound by vibrating according to the operation of the exciters; and a constraint unit configured to constrain the vibration generated in the display unit by the exciters.

Description

Technical Field

[0001] This disclosure relates to a display device and electronic device that integrates sound, and more specifically, to a display device and electronic device that integrates sound to provide improved sound quality. Background Technology

[0002] The dominance of sight and hearing among human senses has driven advancements in display and audio technologies, and recently, there has been increasing interest in multi-sensory integration for more immersive experiences. Therefore, in addition to focusing on the visual quality of displays, research is actively underway into displays that leverage features such as sound and haptic feedback to enhance user experience. So-called "multi-sensory displays," which combine visual, auditory, and tactile sensations, can effectively improve user engagement and realism.

[0003] To develop such multi-sensory displays, additional features such as sound and touch, as well as the visual quality of the screen, are becoming increasingly important in enhancing the overall user experience and achieving more immersive and realistic displays. In short, there is a need for a multi-sensory display that stimulates various human senses to supplement visual information.

[0004] To address this, products integrating displays and speakers are being developed, such as speakers with integrated display panels. However, issues exist, such as reduced usability or decreased sound quality due to structural complexity. Summary of the Invention

[0005] This disclosure aims to provide a sound-integrated display device and electronic device that can solve the above-mentioned problems, has a compact structure, and solves the problem of sound quality degradation.

[0006] In particular, this disclosure aims to provide a display device and electronic device that integrates sound, which can minimize sound interference and improve frequency response.

[0007] To achieve the above objectives, this disclosure provides a sound-integrated display device, comprising: an excitation unit including a plurality of independently operating exciters; a display unit configured to visually display information and generate sound by vibrating according to the operation of the exciters; and a constraint unit configured to constrain the vibrations generated in the display unit by the exciters.

[0008] Here, the constraint unit is configured to separate one side of the display unit, thereby limiting the transmission of vibrations generated in one separated region to another adjacent region. Specifically, the constraint unit is configured to form multiple divided regions, and multiple exciters are respectively disposed in these multiple divided regions.

[0009] Furthermore, each of the exciters is positioned at the center of each of the partitioned regions. A single exciter is set in the corresponding one of the partitioned regions.

[0010] Specifically, the constraint unit includes a frame with a predetermined width and height, and the width of the frame may be at least 2 mm. Alternatively, the height of the frame may be at least 1 mm.

[0011] Furthermore, the constraint unit includes a frame formed of a material having a predetermined Young's modulus, and the Young's modulus of the frame can be configured to have a value greater than the Young's modulus of the display unit.

[0012] The area of ​​the aforementioned partitioned region can be at least twice the cross-sectional area of ​​each exciter. Alternatively, the constraint element comprises a frame forming a mesh, and the edge of each mesh of the frame can have a length of at least 1.4 times the diameter of the exciter.

[0013] Here, the constraint unit is configured such that at least a portion of the multiple partitioned regions form different areas, and the areas of the partitioned regions can be classified based on the frequency bands generated by the exciter. As an example, among the multiple partitioned regions, regions with relatively large areas are assigned to generate sound in relatively low frequency bands, and regions with relatively small areas can be assigned to generate sound in relatively high frequency bands.

[0014] In addition, a controller may be included, which is configured to control the directionality of the sound generated by the display unit by applying acoustic signals with independent time delays or phase differences to multiple exciters respectively.

[0015] At this time, the controller can combine the position information of the visual image displayed on the display unit to control the directional change in real time, so that the focus of the sound tracks the position of the visual image.

[0016] On the other hand, the above-mentioned objectives of this disclosure can also be achieved by an electronic device comprising: an excitation unit including a plurality of independently operating exciters; a display unit configured to visually display information and generate sound by vibrating according to the operation of the exciters; and a constraint unit configured to constrain the vibration generated in the display unit by the exciters.

[0017] According to this disclosure, sound quality can be improved by positioning the vibrations generated by each exciter to minimize interference with vibrations from adjacent exciters.

[0018] Furthermore, by optimizing the design of the frame that forms the constraint unit, the uniformity of the exciter's frequency response can be improved.

[0019] Furthermore, by achieving a consistent and uniform frequency response, it has the advantage of simplifying the loudspeaker response compensation process. Attached Figure Description

[0020] Figure 1 This is a plan view illustrating an electronic device according to an embodiment.

[0021] Figure 2 This is a plan view illustrating an electronic device according to another embodiment.

[0022] Figure 3 This is a perspective view showing the main components of an electronic device according to an embodiment of the present disclosure.

[0023] Figure 4 This is a diagram showing the propagation characteristics of surface vibrations from various sound-generating devices with different structures.

[0024] Figure 5 It is a graph comparing the frequency response characteristics of multiple exciters, depending on the presence or absence of the frame.

[0025] Figure 6 The graphs compare the total harmonic distortion (THD) characteristics of multiple exciters, depending on the presence or absence of the frame.

[0026] Figures 7 to 9 This is a graph showing the vibration characteristics as the width of the constraint element varies.

[0027] Figures 10 to 12 This is a graph showing the vibration characteristics as the height of the constraint element changes.

[0028] Figures 13 to 15 This is a diagram showing the vibration characteristics based on the stiffness of the constraint element.

[0029] Figure 16 This is a diagram showing the surface vibrations generated when multiple actuators are driven depending on the presence or absence of constraint elements.

[0030] Figure 17 This is a diagram illustrating the state of an embodiment of a display device integrating sound according to this disclosure, implemented using a commercial display panel. Detailed Implementation

[0031] In the following description, a display device and electronic device integrating sound according to embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In the following description, the positional relationships of each component are described substantially with reference to the accompanying drawings. Furthermore, for ease of explanation, the drawings may simplify the structure of the present disclosure, or may exaggerate the structure of the present disclosure as needed. Therefore, the present disclosure is not limited thereto, and it is self-evident that the present disclosure can be implemented by adding, modifying, or omitting various means.

[0032] Reference numerals are provided for ease of explanation, and the same components can be described by assigning the same reference numerals. However, even if these components are the same, if they are shown in different figures or are components of different embodiments, they can be described by assigning different reference numerals for ease of explanation.

[0033] Even if the components in the accompanying drawings are partially modified and applied, these components can be considered equivalent components if there is functional similarity and identity. Furthermore, given the skill level of those skilled in the art, the description of components that are considered to be naturally included can be omitted.

[0034] On the other hand, in the following description of this disclosure, a sound display device is primarily described as an example of an electronic device in which the sound generation function is integrated into a display device; however, this disclosure is not limited thereto. Furthermore, it should be noted that this disclosure can be applied to various electronic devices that integrate the function of displaying visual information with the function of generating sound.

[0035] This disclosure relates to an electronic device 1, which may be, for example, a display device integrating sound, or, depending on the viewing angle, a sound device integrating a display panel. The electronic device 1 according to this disclosure is configured to generate sound by using a plurality of piezoelectric elements as exciters to vibrate the display panel forming the display unit 10.

[0036] Recently, in the display field, in addition to visual quality, there is a need to enhance immersion and provide new user experiences by adding features such as sound or haptic feedback. To this end, electrostatic speaker structures, thermoacoustic speaker structures, and electromagnetic speaker structures have been studied in the development of displays with integrated sound, but each structure has limitations in terms of structural complexity, power consumption, and sound quality.

[0037] In contrast, methods using piezoelectric elements, such as those disclosed herein, directly convert electrical energy into mechanical motion via the inverse piezoelectric effect, enabling efficient sound generation with lightweight, flexible, and low-power designs. Furthermore, the simple layered structure comprised of electrodes and piezoelectric materials offers advantages such as low cost, high energy efficiency, and compactness. Additionally, materials such as polyvinylidene fluoride (PVDF) enable flexible, large-area speaker applications, making them ideal for integration with next-generation displays.

[0038] The electronic device according to this disclosure uses multiple exciters to generate sound. Compared to using a single exciter, this can improve speaker performance and achieve a stereo effect. On the other hand, when multiple exciters are used, complex vibrations occur in the display panel that constitutes the diaphragm. This complexity can lead to a deterioration in sound quality and interference between vibrations when different signals are applied to exciters that share a single diaphragm. Furthermore, the arrangement of multiple exciters can lead to inconsistent frequency responses, thus complicating the compensation process. Typically, speaker response compensation involves crossovers, filters, or digital signal processing (DSP), and the requirements increase with the number of speaker channels. In panel speakers where each exciter has a different frequency response, the compensation process can be complex.

[0039] Therefore, this disclosure also includes constraint units 20 that separate areas between the plurality of exciters 31. The constraint units 20 are frames for isolating vibrations generated by each exciter and can prevent mutual interference by limiting and positioning the vibrations of each exciter 31 to a target area.

[0040] Figure 1 This is a plan view illustrating an electronic device according to an embodiment. Figure 2 This is a plan view illustrating an electronic device according to another embodiment. Figure 1 and Figure 2 The rear surface of the electronic device is shown, and a plurality of actuators 31 are arranged in a 3x3 matrix on the rear surface of the display panel forming the display unit 10. Furthermore, Figure 1 The constraint unit 20 of the electronic device 1 includes a rectangular frame and is configured to support only the edges of the display unit. Figure 2 The constraint unit 20 of the electronic device includes a frame forming a grid structure and is configured to separate areas where each exciter is located.

[0041] exist Figure 1In the case of electronic devices, multiple exciters 31 disposed on the same diaphragm (display panel) generate vibrations respectively, and the vibrations generated by each exciter 31 propagate through the diaphragm, causing vibrational interference between them. In particular, this degrades the sound quality of the stereo system. In addition, the position of each exciter 31 significantly affects the frequency response, causing changes in the frequency response in the exciter array.

[0042] In contrast, Figure 2 In the electronic device 1, even if multiple exciters 31 are disposed on a single diaphragm, these exciters are respectively disposed in regions separated by the constraint unit 20. Therefore, by Figure 1 The vibration generated by the exciter propagates throughout the diaphragm, but Figure 2 The vibration of the exciter is confined to a designated area. In this way, localized vibration has the effect of attenuating vibration disturbances and distortions generated by each exciter 31. Furthermore, when each exciter 31 is positioned at the center of the separated area, it has a uniform frequency response overall.

[0043] As discussed above, the electronic device 1 having multiple actuators 31 is preferably configured to include a constraint unit 20, which is configured to separate the area where each actuator is located, such as... Figure 2 As shown. In the following text, reference will be made to... Figure 3 An electronic device according to embodiments of the present disclosure will be described in more detail.

[0044] Figure 3 This is a perspective view showing the main components of an electronic device 1 according to an embodiment of the present disclosure. Figure 3 As shown, the electronic device according to this embodiment includes a display unit, an excitation unit, and a constraint unit.

[0045] The display unit 10 is configured to display visual information to a user and consists of a flat display panel. The front surface of the display panel displays the visual information to the user, and a plurality of actuators 31 are mounted on the rear surface. The display panel is made of a flexible material and is configured to generate sound by vibrating according to the actuators disposed on the rear surface. An OLED panel can be used as an example of the display panel, and in addition, various display panels with flexible structures capable of generating sound through vibration can be applied.

[0046] The excitation unit 30 is a component for vibrating the display unit 10 to generate sound, and consists of an exciter array including a plurality of exciters 31. As an example, each of the exciters 31 is made of a piezoelectric element; however, various other elements capable of generating sound by vibrating the display unit can also be used. Each exciter 31 is configured to contact the display unit 10 on the rear surface of the display unit 10 and convert applied electrical energy into mechanical motion to vibrate the display unit 10. According to this embodiment, the excitation unit 30 is configured as an exciter array, wherein nine exciters 31 are arranged in a 3x3 matrix; however, this disclosure is not limited to this, and the number of exciters can vary depending on the shape or acoustic characteristics of the display unit.

[0047] The constraint unit 20 is a component used to limit the vibrations generated by the exciter 31 in the display unit 10. Here, limiting vibration means limiting the propagation of vibration outside the target area, and it can be spatial limitation, limitation of propagating vibration energy, or limitation of both. In this embodiment, the constraint unit 20 consists of a frame mounted in contact with the rear surface of the display panel. Such a frame is configured to divide the mounting area into multiple partitioned areas, and multiple exciters 31 are configured to be disposed in the multiple partitioned areas respectively. Such a frame is configured to divide the rear surface of the display panel constituting the display unit 10 into multiple areas and to limit the transmission of vibrations generated by the exciter 31 disposed in one partitioned area to another adjacent area.

[0048] At this point, the front surface of the constraint unit is mounted to contact the rear surface of the display unit, and at least a portion of the rear surface of the constraint unit can be configured to form an open end without contacting another component. If the rear surface of the constraint unit is also configured to be attached to a separate rear plate, the multiple partitioned areas formed by the constraint unit will form a closed space through the display unit and the separate rear plate. In this case, vibrations generated by the exciter in the display unit may be reflected from the rear plate, causing interference. Considering this, at least a portion of the rear surface of the constraint unit in this embodiment forms an open end that does not contact another component, thereby separating the multiple partitioned areas from each other on the rear surface of the display unit, but allowing them to be spatially connected. However, this disclosure is not limited to this; the constraint unit can also be configured to be located between the display unit and the separate rear plate.

[0049] Each actuator 31 is disposed in a corresponding one of the regions separated by the constraint unit 20. Furthermore, each actuator 31 can be disposed at the center of each separated region. Therefore, as... Figure 2The vibrations generated by each exciter are positioned to minimize vibrational interference and distortion caused by each other, thereby improving sound quality. Furthermore, by configuring them to have a uniform frequency response overall, the speaker response compensation process, which previously required complex digital signal processing (DSP), crossovers, and filter adjustments, can be simplified.

[0050] Specifically, the constraint unit 20 according to this embodiment includes a frame structure. This frame structure has an external rectangular structure and divides the internal region into multiple subdivision regions through a grid structure. The regions separated by the frame structure can form a 3x3 matrix structure corresponding to the aforementioned exciter array. However, this disclosure is not limited to this, and the shape of the constraint unit can be modified and implemented differently depending on the shape and size of the display unit and the number and arrangement of the exciters.

[0051] Each frame is formed of a material with a predetermined Young's modulus and can be composed of components with predetermined widths and heights. Each component has a rectangular cross-section, and the width of the frame can refer to the width in contact with the display panel. In this embodiment, the frame can be composed of a single integrally molded component. This is because when the frame adopts a structure combining multiple components, vibrations may occur at the joints during the vibration of the display unit, resulting in noise, and the vibration damping characteristics may vary depending on the joint state. Furthermore, in the frame of this embodiment, the remaining components (components disposed between the divided areas to separate the areas) except for the components forming the outer edge can be formed to have the same width and height. This is to maintain consistent vibration damping characteristics according to the shape of the frame.

[0052] However, this disclosure is not limited thereto, and the frame forming the constraint element may consist of multiple individual components instead of a single frame, and components of various shapes other than rectangular cross sections may also be used to form the constraint element.

[0053] In the following text, reference will be made to Figures 4 to 16 The characteristics of the electronic device according to this embodiment and the changes in vibration characteristics according to the configuration of the constraint unit are described in detail.

[0054] Figure 4 The propagation characteristics of surface vibrations of sound-generating devices with various structures are shown. Here, the sound device is configured using an exciter and a frame disposed on a single diaphragm (corresponding to the display unit of this disclosure). Furthermore, regarding the propagation characteristics of the vibrations, a Chladni pattern can be used to visualize the propagation of vibrations occurring on the surface of the single diaphragm through fine particles such as sand when an acoustic signal is applied to the exciter located at the center.

[0055] Reference Figure 4For various frequency bands (1000 Hz to 20000 Hz), a unit element model with only a single exciter and a frameless model with a 3x3 array of exciters fixed only to the outer edge of the diaphragm are compared and illustrated (corresponding to...). Figure 1 (The embodiment) and a framed model in which the region of each exciter is separated by a mesh-like frame (corresponding to) Figure 2 Vibration aspects (in the embodiments).

[0056] In the case of a model where the region is not divided by a frame ( Figure 4 In a system without a frame, a phenomenon was observed where vibrations generated by the central exciter escaped the target area and even spread widely to the peripheral area where adjacent exciters were located. Therefore, in a multi-exciter environment with different applied signals (e.g., a stereo system), the propagation of vibrations across the entire diaphragm (display unit) causes vibration interference between adjacent exciters, resulting in sound distortion and a decrease in overall sound quality.

[0057] On the other hand, in the case of a model where the region is divided by a frame ( Figure 4 With a frame in place, it can be confirmed that vibrations generated from the central exciter are effectively confined to the designated area where the corresponding exciter is located, and propagation to adjacent peripheral areas is significantly blocked. In other words, when the constraint unit 20 positions the vibration of the surface of the display unit 10 (vibration positioning) and physically isolates the vibrations between the exciters, crosstalk-free vibration operation with minimized interference and distortion can be achieved even in a multi-exciter environment.

[0058] Figure 5 It is a graph comparing the frequency response characteristics of multiple exciters, depending on the presence or absence of the frame.

[0059] For reference, this measurement, used to confirm the frequency response characteristics, is performed inside an anechoic chamber of predetermined size to eliminate external noise interference and accurately analyze the sound. During the measurement, a 10V peak-to-peak sine wave signal is generated using a waveform generator (e.g., PXIe-5413) and applied to each exciter located on the rear surface of the display unit, scanning a frequency band from 200 Hz to 20000 Hz for 30 seconds. Meanwhile, a microphone (e.g., B&K4966) and a sound and vibration module (e.g., PXIe-4494) are used to collect and measure the sound output from the electronic device, and overall control of signal generation and data collection is performed via signal processing software (e.g., LabVIEW).

[0060] Reference Figure 5The on-axis frequency response can be confirmed based on the position (numbered sequentially from top left) of each of the nine exciters 31 arranged in a 3x3 array on the rear surface of the diaphragm. This is in the case of a model where the region is not separated by a frame. Figure 5 Without a frame, it can be seen that the frequency response varies depending on the position of each exciter 31, resulting in large deviations. On the other hand, in a model where the region of each exciter 31 is physically separated by a frame ( Figure 5 (Within the frame), the nine exciters exhibit consistent frequency response characteristics with very small overall deviation.

[0061] When generating sound, consistency across multiple exciters is crucial for achieving high-quality sound unless a specific frequency band is intentionally emphasized. Therefore, the consistent frequency response characteristics achieved by the constraint unit (frame) 20 greatly simplify the signal processing procedures of crossovers, filters, and equalizers necessary for frequency response compensation in acoustic devices.

[0062] Figure 6 These are graphs comparing the total harmonic distortion (THD) characteristics of multiple exciters, depending on the presence or absence of the frame. For reference, the results are based on... Figure 5 The data was obtained from the experimental environment described in the text, and the calculation was performed by applying the values ​​of the first harmonic (fundamental frequency) component to the nth harmonic component to the calculation formula.

[0063] Reference Figure 6 In an exciter array sharing a single diaphragm (display unit), the total harmonic distortion (THD) is compared and shown for the location of the element applying the signal, with and without a frame. Total harmonic distortion (THD) is a key indicator of accurate signal reproduction, and the lower the value, the less sound distortion, meaning a clearer output sound.

[0064] like Figure 6 As shown, in the case of a model where the region is not divided by a frame ( Figure 6 (Without a frame), it can be confirmed that the high THD frequency band varies randomly depending on the position of the driven exciter, and the measured total THD value is also relatively high.

[0065] On the other hand, as in embodiments of this disclosure, in a model where the region of each exciter is physically separated by the frame ( Figure 6 With a frame, the overall THD is significantly lower, resulting in clearer and more accurate signal reproduction. Furthermore, when a frame is present, even if the position of the driven exciter changes, the frequency bands with increased THD maintain a unique characteristic of remaining similar (aligned) to each other.

[0066] Similar to the previous Figure 5The frequency response described herein, and the THD of the sound-generating device, can also be compensated for through digital signal processing (DSP), etc. Therefore, the structure that uses a frame (with a frame) to separate the areas where the exciters are set not only simply reduces the total THD value, but also aligns the frequency bands with high THD among multiple exciters into one, which ultimately has the advantage of greatly simplifying the signal processing process required for sound compensation in multi-speaker systems.

[0067] As mentioned above Figures 4 to 6 As described above, the constraint unit 20, which divides the regions of multiple exciters 31, isolates the vibrations generated by each exciter 31, thereby helping to improve the quality of the sound generated by the electronic device 1. The vibration isolation effect generated by the constraint unit 20 varies depending on the material, shape, and size of the frame constituting the constraint unit 20.

[0068] Specifically, the sound waves generated by driving the exciter 31 positioned in one region propagate along the display unit 10 and are partially absorbed and attenuated by the constraint unit before being transmitted to adjacent regions. According to the wave equation, the degree of wave attenuation within the constraint unit is determined by the time absorption coefficient (β), which is an inherent property of the material. Therefore, even if the constraint units are configured with the same material, the absorption coefficient becomes higher as the size (width, height, etc.) of the constraint units increases, potentially leading to a stronger attenuation effect. Furthermore, since wave pressure has the characteristic of decreasing exponentially with increasing propagation distance within the constraint unit, the width and height of the constraint unit affect the positioning performance of limiting surface vibrations only within the region of each exciter. Therefore, the performance variations based on the frame configuration will be described in detail below, based on experimental results.

[0069] First, in the electronic device according to this embodiment, it is confirmed that the vibration generated by the exciter propagates to the adjacent area, and at this time, the attenuation of the vibration occurs differently depending on the width (w) of the frame along the propagation path.

[0070] Figure 7 Comparison based on Figure 3 The surface vibration localization effect of varying width (w) of the constraint element in the experiment. Specifically, when a signal of a specific frequency (e.g., 3 kHz) is applied only to the central exciter among a plurality of exciters 31 arranged in a 3x3 configuration, the propagation aspect of surface vibration of the diaphragm with constraint elements 20 having different widths is visualized using the finite element method (FEM) and a Krahni pattern using sand.

[0071] As an experimental result, in the narrow frame model with a constraint unit width of 1 mm, wave attenuation was not sufficiently implemented, resulting in the observation that vibrations generated from the central exciter propagate beyond the constraint unit into the peripheral area where other adjacent exciters are located. However, in the medium frame model with a constraint unit width of 3 mm and the wide frame model with a width of 5 mm, the localization phenomenon was clearly confirmed: the generated vibrations do not propagate to another adjacent area and are effectively confined only to the designated area of ​​the driven exciter.

[0072] Figure 8 This is a graph comparing the frequency response characteristics of multiple exciters according to the width variation of the constraint unit, based on embodiments of the present disclosure.

[0073] Reference Figure 8 This shows, as Figure 7 The frequency response of each exciter in a 3x3 array (a total of 9) on the rear surface of the display unit 10, which employs constraint units 20 with different widths, was described. Examining the experimental results, as the standard deviation of the frequency response among the 9 exciters calculated within the 200 Hz to 2000 Hz frequency band where human hearing is most sensitive, confirmed that the narrow frame model with a constraint unit width of 1 mm had a mean standard deviation of 3.801 dB, the medium frame model with a width of 3 mm had a mean standard deviation of 3.407 dB, and the wide frame model with a width of 5 mm had a mean standard deviation of 2.457 dB.

[0074] This indicates that as the width of the frame members constituting constraint unit 20 increases, the response deviation between each exciter within this critical frequency range decreases significantly. Combined with previous... Figure 7 The vibration positioning results show that as the width of the constraint element increases beyond the predetermined width, the performance of limiting surface vibration is greatly improved. Therefore, even in a multi-exciter environment, the individual exciters do not interfere with each other and exhibit a uniform and consistent frequency response.

[0075] Figure 9 This is a graph comparing the sound pressure level (SPL) deviations of a specific note generated from multiple exciters based on the width variation of the constraint unit, according to embodiments of the present disclosure.

[0076] Reference Figure 9 The results confirm the standard deviation of the sound pressure level among the nine exciters measured at frequencies corresponding to the "A note" commonly used in audio engineering: A4 (220 Hz), A5 (440 Hz), A6 (880 Hz), and A7 (1760 Hz). This is consistent with... Figure 8Together with the average deviation of the entire 200 Hz to 2000 Hz frequency band described in the figure, this graph specifically illustrates the uniform performance of the loudspeaker system at specific frequencies (notes) in reproducing actual music.

[0077] Based on the measurement results, in a frameless model where the vibrations of the exciters are not physically isolated (localized) by the constraint units, it can be seen that the standard deviation among the nine exciters is relatively very high at specific lower intermediate scales (e.g., A4 and A5). This means that interference between the individual components in a multi-exciter system can significantly degrade the sound quality in specific frequency bands.

[0078] Furthermore, even with the constraint unit 20 in place, it was confirmed that the wider its width (w), the more consistent the standard deviation at the minimum level was across all note frequencies from A4 to A7. This indicates that when the width of the constraint unit 20 is ensured to be at a predetermined level or greater, the ability to block vibrational interference across the entire spectrum of the loudspeaker is maximized without being concentrated in a specific frequency band.

[0079] In summary Figures 7 to 9 The results shown demonstrate that when a constraint unit 20 with an optimized width at a certain level is applied to the rear surface of the display unit to separate the areas of the multiple exciters 31, wave attenuation is maximized, and thus vibration localization performance is significantly improved. This fundamentally prevents vibration interference between adjacent elements in a multi-channel speaker system and enables precise local sound control. Furthermore, by suppressing response deviations in each frequency band on each exciter to ensure consistent frequency response characteristics, the complex frequency response compensation process utilizing crossovers, filters, digital signal processing (DSP), etc., is greatly simplified. Ultimately, this disclosure provides excellent sound quality that is uniform and distortion-free across the entire frequency range without being biased to a specific frequency band. This has been confirmed to exhibit a positive effect as the width of the constraint unit increases, and considering the dominant frequency range to be generated in the electronic device (e.g., 200 Hz to 1500 Hz), improved sound quality is confirmed when the frame width is at least 2 mm or greater.

[0080] On the other hand, not only the width (w) but also the height (h) of the frame constituting the constraint unit 20 has a significant impact on wave attenuation and vibration isolation effects. The sound waves generated by the exciter 31 of the display unit 10 are absorbed and attenuated by constraint units with different stiffnesses during propagation, and then transmitted back to the display unit or emitted into the air to generate sound. Therefore, as the height of the constraint unit increases, the wave attenuation effect is enhanced, which can lead to stronger vibration restriction.

[0081] Figure 10This is a graph comparing and illustrating the surface vibration positioning effect according to embodiments of the present disclosure, based on variations in the height of the constraint unit. (Refer to...) Figure 10 When a signal of a specific frequency (e.g., 3 kHz) is applied to the exciter 31 located at the center with the width (w) fixed at a constant 5 mm, it can be confirmed by the finite element method (FEM) and the use of a kraney pattern in sand, that the signal can be visualized within a short frame with a height of 0.5 mm. Figure 10 (short frame), medium frame with a height of 1mm ( Figure 10 Medium frame) and high frame with a height of 2mm ( Figure 10 Results regarding surface vibration in the case of a high frame (in the case of a high frame). As experimental results, when the height of the constraint element 20 is low, the phenomenon of vibration generated by the central exciter escaping the target area and spreading and propagating to the peripheral area where other adjacent exciters 31 are located is clearly observed by finite element method (FEM) simulation. On the other hand, the results from the Clani pattern show that when the height of the constraint element reaches a certain level (e.g., 1 mm) or higher, the localization phenomenon is confirmed: the vibration no longer spreads to adjacent areas and is effectively confined to the corresponding designated area.

[0082] Figure 11 This is a graph comparing the frequency response characteristics of multiple exciters according to variations in the height of the constraint unit, based on embodiments of the present disclosure. (Refer to...) Figure 11 The on-axis frequency response deviation of each exciter 31 was confirmed based on the height variation of the constraint unit 20 in an array of nine exciters arranged in a 3x3 array. As the result of measuring the average standard deviation of the frequency response among the nine exciters 31 within the 200 Hz to 2000 Hz frequency band, where human hearing is most sensitive, the short frame model with a height of 0.5 mm had 2.736 dB, the medium frame model with a height of 1 mm had 2.691 dB, and the tall frame model with a height of 2 mm had 2.457 dB. This indicates that as the height of the constraint unit 20 increases, the frequency response deviation among each exciter decreases significantly, resulting in a more consistent response characteristic.

[0083] Figure 12 This is a graph comparing the sound pressure level (SPL) deviation and average total harmonic distortion (THD) characteristics of a specific note generated from multiple exciters based on variations in the height of the constraint unit, according to embodiments of this disclosure. (Refer to...) Figure 12The results confirm the standard deviation of the sound pressure level among the nine exciters 31 at the A note (A4, A5, A6, A7), which is widely used as a standard in audio engineering. The frameless model, where the vibrations are not physically isolated (positioned) by the constraint unit, shows a relatively high level of standard deviation in specific frequency bands such as A4 and A5. On the other hand, while the model equipped with the constraint unit 20, which positions the vibrations, does not show a significant linear deviation trend across all frequencies with increasing frame height, it confirms a consistently low standard deviation overall, regardless of each drive position, compared to the case without the constraint unit 20. Furthermore, examining the average total harmonic distortion (THD) measurements, all models applying the constraint unit show a significant reduction in THD in the low-to-mid frequency range and the mid-frequency range of the hearing-sensitive response, compared to the model without the constraint unit.

[0084] Therefore, in summary Figures 10 to 12 The experimental results show that the constraint unit 20 with a constant width exerts strong vibration localization performance by more effectively absorbing and attenuating vibrations when its height is ensured to be at least 1 mm or greater. By applying the constraint unit 20 with an optimized height to the rear surface of the display unit 10 in this way, vibration interference occurring between adjacent components in a multi-exciter environment can be fundamentally blocked, and frequency response deviations between the individual exciters 31 can be significantly reduced. This ensures consistent frequency response performance on the multi-channel speaker system, thereby not only greatly simplifying the complex signal compensation process, but also significantly suppressing sound distortion (THD) in the sensitive low-to-mid range, further improving overall sound quality.

[0085] Furthermore, not only the shape (width and height) of the aforementioned constraint unit 20, but also the mechanical stiffness (especially Young's modulus) of the material constituting the constraint unit 20 has a significant impact on surface vibration propagation and isolation effects. If the Young's modulus of the frame constituting the constraint unit 20 is lower than that of the display panel constituting the display unit 10 used as a diaphragm, the constraint unit 20 vibrates together with the display unit 10, causing distortion. Conversely, when the constraint unit 20 has a higher Young's modulus than the display unit, the constraint unit 20 can more effectively localize vibrations.

[0086] Figure 13 This is a diagram comparing and illustrating the surface vibration positioning effect based on the Young's modulus difference between the constraint unit and the display unit, according to embodiments of the present disclosure. (Refer to...) Figure 13The results of simulations using the Cranny pattern and finite element method (FEM) visualized the surface vibrations that occur when a signal of a specific frequency (e.g., 3 kHz) is applied to the exciter 31 located at the center. In this experiment, based on the material constituting the display unit (diaphragm) 10 (e.g., a PET film with a Young's modulus of 1.9 GPa), a model using a constraint unit with a lower Young's modulus was compared. Figure 13 The lower frame modulus - left-hand results, such as polycarbonate (PC) with a Young's modulus of 1.1 GPa, and models applying constraint elements with the same Young's modulus ( Figure 13 Intermediate results) and models using constraint elements with high Young's modulus ( Figure 13 The higher frame modulus – results on the right, for example, stainless steel (SUS) with a Young's modulus of 193 GPa. As experimental results, in the model using constraint unit 20 with a Young's modulus lower than that of display unit 10, vibration localization was improved to some extent compared to the case without any constraint unit, but a considerable amount of vibration generated in the central exciter 31 was still observed to be transmitted (propagated) beyond constraint unit 20 to the adjacent exciter area. On the other hand, in embodiments of this disclosure using constraint unit 20 with a Young's modulus equal to or higher than that of display unit 10, excellent vibration localization performance was shown by effectively preventing the vibration from propagating to adjacent areas by more firmly confining the generated vibration within the target area.

[0087] Figure 14 This is a graph comparing the frequency response characteristics of multiple exciters based on the Young's modulus difference between the constraint unit and the display unit, according to embodiments of the present disclosure. (Refer to...) Figure 14 It can be confirmed that each of the nine exciters 31 arranged in a 3x3 array is relative to the above. Figure 13 The on-axis frequency response deviations of the low-modulus frame application model and the high-modulus frame application model described herein are examined. As a result of the measurements, the model applying the constraint unit 20 with a low Young's modulus exhibits a relatively high mean standard deviation of 3.129 dB among the nine exciters in the 200 Hz to 2000 Hz frequency band, where human hearing is most sensitive. On the other hand, in the model of this disclosure applying the constraint unit 20 with a higher Young's modulus than the display unit 10, the mean standard deviation was measured to be a significantly lower 2.457 dB within the same frequency band. Therefore, it can be seen that the frequency response deviations among the exciters are very small, and they exhibit consistent response characteristics. This means that when the material of the constraint unit 20 has a sufficiently higher stiffness than the diaphragm, uniform frequency response characteristics beneficial to signal compensation across the entire multi-exciter system can be ensured.

[0088] Figure 15This is a graph comparing the sound pressure level (SPL) deviations of a specific note generated from multiple exciters based on the Young's modulus difference between the constraint unit and the display unit, according to embodiments of this disclosure. (Refer to...) Figure 15 The results confirm the standard deviation of the sound pressure level among the nine exciters in the A note (A4 to A7), which is widely used as a standard in audio engineering. When a constraint unit (lower modulus frame) with a lower Young's modulus than display unit 10 is applied, the performance is uneven among the multiple exciters, still showing a high level of deviation in specific note bands (e.g., A4 and A7). However, in embodiments of this disclosure using a constraint unit (higher modulus frame) with a higher Young's modulus than display unit 10, a consistently low level of deviation was confirmed across all note bands from A4 to A7.

[0089] Therefore, in summary Figures 13 to 15 The experimental results show that, when designing the constraint unit 20 of a sound display device, configuring the constraint unit (frame) with a material having a higher Young's modulus (stiffness) than the display unit 10 used as a diaphragm helps improve acoustic performance. As experimental results, the aforementioned advantageous effect can be achieved when the frame material has a Young's modulus in the range of 2 to 200 times that of the material forming the panel of the display unit. More specifically, the aforementioned advantageous effect can be achieved when the frame material has a Young's modulus in the range of 5 to 100 times that of the material forming the panel of the display unit. Furthermore, when configuring a display device integrating sound using a flexible display panel, if the constraint unit is configured with a material whose Young's modulus is in the range of 1.5 to 10 times that of the panel material of the display unit, effective vibration damping and improved acoustic performance can be observed.

[0090] Therefore, when a constraint unit 20 with higher stiffness than the display unit 10 is applied, vibration localization performance can be maximized by strongly preventing the vibrational energy of each exciter from leaking into adjacent areas. Furthermore, this maximized vibrational isolation effect minimizes deviations and achieves a consistent frequency response regardless of the drive position or specific frequency (note) band in a multi-exciter environment. This greatly simplifies the sound compensation process via crossovers or digital signal processing (DSP) and yields significant results, providing clear and distortion-suppressed superior sound quality across the entire frequency range of the system.

[0091] In summary, when comparing the effects of variations in the dimensions (width, height) and material (Young's modulus) of the constraint unit (frame) incorporated into the display unit 10 on the acoustic response characteristics, it was confirmed that increasing the width and height of the constraint unit 20 and simultaneously using a material with higher stiffness than the diaphragm are factors that ensure the consistency of frequency response across the multiple exciters 31 and improve response compensation efficiency. Specifically, considering the characteristics in the main frequency band to be generated in the electronic device 1, it was found that the desired constraint unit width is 2 mm or more, the height is 1 mm or more, and the material of the constraint unit 20 is used as a rigid material with a higher Young's modulus than that of the display unit.

[0092] Furthermore, the results of evaluating the operational reliability of the electronic device (sound display device) having areas separated by constraint units according to embodiments of this disclosure are as follows. As a result of evaluating time stability based on continuous drive to check for performance degradation due to mechanical or electrical factors (stress, temperature changes, etc.), when a remeasurement was performed after 10 minutes of continuous drive following the initial frequency response measurement, it was confirmed that the response characteristics remained almost constant within the error range. Therefore, it can be seen that the performance is stable even with long-term drive. Furthermore, regarding the sound pressure output characteristics, it was confirmed that the sound pressure increases linearly proportionally to the magnitude of the applied voltage (peak-to-peak voltage) to provide a stable and linear output that satisfies basic acoustic principles. Furthermore, as a result of measuring the sound pressure variation based on distance from the center of the speaker, the sound pressure decreases consistently with increasing distance, and specifically, the sound pressure characteristic is halved when the distance is doubled.

[0093] Therefore, the integrated sound display device using the constraint unit structure according to this disclosure can stably provide predictable and highly reliable speaker performance over long periods of time, in terms of time, electricity and space, as well as vibration isolation and sound quality improvement.

[0094] On the other hand, in a stereo system where multiple exciters are arranged on a display unit consisting of a single panel, when different sound signals are applied to different exciters, mutual interference occurs between the vibrations generated from each exciter, which may reduce the overall sound quality.

[0095] Figure 16 The diagram is a comparison of embodiments of the present disclosure and illustrates the surface vibration disturbances and isolation effects generated when driving multiple actuators depending on the presence or absence of constraint units. Figure 16 (a) shows the vibration aspect in a model without constrained elements (or a model that only supports the outer edge of the display elements), and Figure 16 (b) illustrates the vibration aspect in a model in which the regions of each exciter are physically separated by constraint elements according to an embodiment of the present disclosure.

[0096] Reference Figure 16 The results of vibration propagation on the surface of the display unit can be confirmed by using a claney pattern of sand and the finite element method (FEM) to simulate and visualize the vibration propagation that occurs when a 5 kHz signal is applied to the exciter located in the lower left and a 20 kHz signal is simultaneously applied to the exciter located in the center.

[0097] As experimental results, such Figure 16 As shown in (a), in the model without region partitioning by constraint elements (no frame separation), it was confirmed that the vibration patterns of the 5 kHz signal and the 20 kHz signal overlapped with each other outside their corresponding regions. This indicates severe vibration interference between adjacent exciters 31, making it impossible for each signal to be reproduced completely and independently.

[0098] On the other hand, such as Figure 16 As shown in (b), in a structure where the regions of each exciter 31 are divided by the constraint unit 20 (with frame separation), it can be confirmed that the corresponding vibration patterns generated by the 5 kHz and 20 kHz signals are clearly presented and isolated only within their respective designated regions. That is, it demonstrates excellent results in which the phenomenon of vibration waves generated in one region being transmitted to another region or mixing with each other is effectively separated and blocked (effective vibration separation).

[0099] In summary, the integrated sound display device (or electronic device) according to various embodiments of this disclosure prevents vibration interference (crosstalk) on the surface of the diaphragm and significantly improves frequency response characteristics through local control of the multi-array exciter, thereby providing precise local sound output that is fully synchronized with the visual image.

[0100] In particular, by introducing a constraint element (frame) structure for vibration isolation with optimized shape (width and height) and material (Young's modulus), this disclosure has successfully achieved crosstalk-free sound emission that can be independently controlled for each exciter, even in a single diaphragm-based panel piezoelectric loudspeaker environment. The constraint element effectively confines surface vibrations within a designated area to fundamentally block propagation to adjacent areas and has the effect of greatly simplifying the complex response compensation process by reducing the standard deviation by increasing the uniformity of the frequency response among the exciters.

[0101] In particular, when the width and height of the constraint unit are ensured to be at a certain level or higher, and the constraint unit is formed of a material with a higher modulus than that of the diaphragm (display unit), the vibration localization performance is maximized to significantly reduce total harmonic distortion (THD) over a wider frequency band, thus enabling the reproduction of clearer and more accurate high-quality sound.

[0102] However, when the width of the constraint unit is excessively extended, the area of ​​the display unit that vibrates to generate sound may be excessively reduced. Therefore, when designing the constraint unit, the shorter side length of the partitioned area separated by the frame (excluding the vibrating area of ​​the frame) should be considered. Figure 3 The l) in the figure can be configured to be at least 1.4 times the diameter (d) of the exciter. Alternatively, the partitioned regions separated by the frame can be configured to be at least twice the cross-sectional area of ​​the exciter.

[0103] The framework of the above embodiment is configured to form a rectangular division region, but this disclosure is not limited thereto. Depending on the shape or acoustic design of the display unit, it can also be configured to form a square division region or a circular, regular hexagonal, or other division region.

[0104] Furthermore, while the frameworks of the above embodiments are all configured to form partitioned regions of the same size, this disclosure is not limited thereto. As an example, when the exciter outputs are different, the partitioned region provided with an exciter having a large output can be formed relatively wide, and the partitioned region provided with an exciter having a small output can be formed relatively narrow. As another example, even when the exciter outputs are the same, the partitioned region located at the edge of the display unit can be formed relatively smaller or relatively larger than the partitioned region located inside the display unit. In this way, the size of the partitioned regions can be implemented differently depending on the exciter output and the acoustic characteristics to be designed. Or, as another example, the area of ​​the partitioned regions can be configured differently based on the frequency band of the vibration generated by the exciter. For example, among multiple partitioned regions, a region with a relatively large area can be allocated to generate a low-frequency band sound corresponding to a relatively low frequency band. And, a region with a relatively small area can be allocated to generate a high-frequency band sound corresponding to a relatively high frequency band.

[0105] Furthermore, the frame in the above embodiments is formed with a structure having the same width and height, but this disclosure is not limited thereto. It can also be configured such that the width or thickness at each location differs depending on the shape or acoustic design of the display unit. As an example, the portion of the frame adjacent to the exciter can be formed with a relatively wide width and high height, and the portion spaced apart from the exciter can be formed with a relatively narrow width and low height.

[0106] Figure 17 This diagram illustrates the state of applying a sound-integrated display device according to an embodiment of the present disclosure to a commercial display panel.

[0107] Reference Figure 17 This confirms that the speaker module, attached to multiple piezoelectric exciters and constraint units for vibration isolation, is integrated into the rear surface of a commercial display panel (e.g., a 13-inch OLED panel) to actually play audio. Figure 17In cases such as previously Figure 16 As confirmed, the driving regions of each exciter are physically and perfectly isolated (without crosstalk) through constraint units to induce independent local surface vibrations. This allows for precise local acoustic control that is perfectly synchronized with the visual image on the display. In particular, even when the display panel vibrates due to the drive of the speakers, no degradation or deterioration of the visual image quality of the display is observed, and experiments have demonstrated that high-quality sound can be provided while maintaining a clear image quality at the same level as a standalone OLED display.

[0108] Furthermore, the “sound pixel independent array” structure, which perfectly positions vibrations through constraint units in this way, provides an optimized hardware foundation for realizing sound beamforming and directional control as a next-generation acoustic technology.

[0109] In conventional single-diaphragm-based panel loudspeakers, independent phase control of each exciter is practically impossible due to vibration interference (crosstalk) generated as vibrations propagate across the entire panel, thus posing a fatal hardware limitation when applying sound beamforming technology. However, this disclosure physically isolates (physically isolates) vibration energy by confining it within specific zones using a grid-like frame (constraint unit), thereby allowing each exciter to function as a completely independent point source.

[0110] Therefore, the electronic device (sound display device) according to embodiments of this disclosure may further include a controller (not shown) configured to control the directionality of sound. This controller can apply signals controlling independent time delays or phases to multiple exciters respectively. Since each region is physically separated, no distortion due to interference occurs even when different phase and amplitude signals are applied to multiple exciters, and thus, precise phased array control can be performed to perfectly induce constructive and destructive interference of sound waves in a specific space.

[0111] Furthermore, the uniform frequency response and low THD characteristics among the exciters derived through numerical optimization of the constraint units (e.g., applying widths greater than 2 mm, heights greater than 1 mm, and Young's modulus higher than that of the display units) form a "predictable sound field." This "predictable sound field" ensures that the actual radiated sound field matches the physical wave result predicted by the beamforming algorithm. The reliability and efficiency of the beamforming system are maximized because high-quality, independent acoustic signals in a crosstalk-free state are protected before software (DSP) compensation.

[0112] Based on this precise directional control, the controller can perform adaptive beamforming, which focuses the sound beam on a specific location (e.g., the user's location) or moves it in real time. Furthermore, by incorporating the positional information (coordinates) of a visual image (object) displayed on the screen of the display unit, the controller can control the sound beam to track the visual image and change in real time around an exciter corresponding to the object's coordinates.

[0113] Therefore, unlike traditional methods that rely solely on software compensation, this disclosure fundamentally solves the interference problem through a physical structure called a "constraint unit," thereby not only providing users with an immersive multi-sensory display experience that maximizes audiovisual synchronization, but also significantly improving the scalability of large-area panel speaker arrays.

[0114] In addition, such as Figure 17 As shown, the sound-integrated display device according to this embodiment can be realized with a thin structure by using a piezoelectric element as an exciter and using a constraint unit with optimized material properties and shape. Specifically, the thickness of the exciter can be configured to be 5 mm or less, and the sound-integrated display device including such an exciter and the aforementioned constraint unit can be implemented with a thickness of 10 mm or less.

[0115] As described above, the results of a long-term reliability assessment of a display device employing the local acoustic control structure according to this disclosure (e.g., the 13-inch OLED panel used in this experiment) confirmed that it maintains its performance as a highly stable and reliable sound-generating device even after prolonged operation by displaying consistent and predictable variations in sound pressure level (SPL) based on input voltage and distance. These technical features of this disclosure provide significant improvements in the acoustic quality and durability of thin and flexible integrated sound display devices. Furthermore, they can serve as fundamental technologies for the commercialization and expansion of next-generation multi-sensory audiovisual display systems, including OLEDs, that substantially require high-quality sound integration.

[0116] An embodiment of this disclosure has been described in detail above, but aspects of this disclosure are not limited to the above embodiment. Those skilled in the art will understand that various modifications and changes can be made to this disclosure by including, altering, removing, or adding elements without departing from the spirit and scope of the disclosure as defined by the appended claims.

Claims

1. A display device integrating sound, comprising: An excitation unit, the excitation unit comprising a plurality of exciters configured to operate independently; The display unit is configured to visually display information and generate sound by vibrating in response to the operation of the exciter; as well as A constraint unit configured to constrain vibrations generated in the display unit by the exciter.

2. The display device integrating sound according to claim 1, wherein, The constraint unit is configured to separate one side of the display unit, thereby limiting the transmission of vibrations generated in one separated area to another adjacent area.

3. The display device integrating sound according to claim 1, wherein, The constraint unit is configured to form multiple partitioned regions, and the multiple exciters are respectively disposed in the multiple partitioned regions.

4. The display device integrating sound according to claim 3, wherein, Each of the actuators is configured to be located at the center of each of the divided regions.

5. The display device integrating sound according to claim 3, wherein, Each of the actuators is individually disposed in a corresponding one of the divided regions.

6. The display device integrating sound according to claim 1, wherein, The constraint unit includes a frame having a predetermined width and height, wherein the width of the frame is at least 2 mm.

7. The display device integrating sound according to claim 1, wherein, The constraint unit includes a frame having a predetermined width and height, wherein the height of the frame is at least 1 mm.

8. The display device integrating sound according to claim 1, wherein, The constraint unit includes a frame formed of a material having a predetermined Young's modulus, and the Young's modulus of the frame has a value greater than that of the display unit.

9. The display device integrating sound according to claim 3, wherein, The area of ​​the divided region is at least twice the cross-sectional area of ​​each of the actuators.

10. The display device integrating sound according to claim 3, wherein, The constraint unit includes a frame forming a mesh, and each mesh of the frame has an edge with a length of at least 1.4 times the diameter of the exciter.

11. The display device integrating sound according to claim 3, wherein, The constraint unit is configured such that at least a portion of the multiple partitioned regions form different areas, and the areas of the partitioned regions are classified based on the frequency band generated by the exciter.

12. The display device integrating sound according to claim 11, wherein, Among the multiple partitioned regions, regions with relatively large areas are configured to generate sound in relatively low frequency bands, and regions with relatively small areas are configured to generate sound in relatively high frequency bands.

13. The sound-integrated display device of claim 1, further comprising a controller configured to control the directionality of sound generated through the display unit by applying acoustic signals having independent time delays or phase differences to the plurality of exciters respectively.

14. The display device integrating sound according to claim 13, wherein, The controller is configured to control the directional changes in real time by incorporating positional information of the visual image displayed on the display unit, so that the focus of the sound tracks the position of the visual image.

15. The display device integrating sound according to claim 1, wherein, Each of the exciters has a thickness of less than 5 mm, and the sound-integrated display device is configured to have a thickness of less than 10 mm.

16. An electronic device comprising: The excitation unit includes multiple independently operating exciters; The display unit is configured to visually display information and generate sound by vibrating according to the operation of the exciter; as well as A constraint unit configured to constrain vibrations generated in the display unit by the exciter.

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