Display device

Abstract

To solve the problem with a general display apparatus in which a sound output from a sound device travels to a rearward or downward direction of a display panel and thus the sound quality is degraded by interference between sounds reflected from a wall and a floor, which makes it difficult to transfer an accurate sound.SOLUTION: A display apparatus includes a display module 100 with a display panel 110 to display an image. A rear cover 300 is on a rear surface of the display module. A first vibration generating module 400 is in a first rear region of the rear cover, and a second vibration generating module 500 in a second rear region of the rear cover. The rear cover includes a first hole 313 that overlaps the first vibration generating module, and a second hole 315 that overlaps the second vibration generating module.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] This application relates to a display device, and more particularly, to a display device having a display panel that outputs sound.

Background Art

[0002] Generally, a display device is used for a screen that displays images and is mounted on electronic products or home appliances such as televisions, monitors, notebook computers, smartphones, tablet computers, electronic pads, wearable devices, watch phones, portable information devices, navigation devices, or vehicle control display devices.

[0003] A general display device can include a display panel that displays an image and an audio device that outputs audio related to the video.

[0004] However, in a general display device, since the sound output from the audio device travels behind or below the display panel, the sound quality deteriorates due to interference between the sounds reflected from the wall or the floor (ground), and thus there is a problem that accurate sound transmission is difficult, and there is also a problem of reducing the immersion feeling of the viewer.

Summary of the Invention

[0005] An object to be solved by an embodiment of the present application is to provide a display device capable of accurate sound transmission.

[0006] An object to be solved by an embodiment of the present application is to provide a display device capable of improving sound quality and enhancing the immersion feeling of the viewer.

[0007] An object to be solved by an embodiment of the present application is to provide a display device capable of generating sound that can travel in front of the display panel.

[0008] In addition to the above-described technical problems of the present invention, other features and advantages of the present invention will be described below or will be clearly understood by those having ordinary knowledge in the technical field to which the present invention pertains from such descriptions and explanations.

[0009] A display device according to an embodiment of the present application includes a display module including a display panel for displaying an image, a rear cover disposed on the rear surface of the display module, a first vibration generation module disposed in a first rear region of the rear cover, and a second vibration generation module disposed in a second rear region of the rear cover, and the rear cover may include a first hole overlapping the first vibration generation module and a second hole overlapping the second vibration generation module.

[0010] A display device according to an embodiment of the present application includes a display module including a display panel for displaying an image, a rear cover including a rear cover portion covering the rear surface of the display module, and a first vibration generation module and a second vibration generation module all disposed in the rear cover portion and vibrating the display module, and the rear cover portion may include a first gap disposed between the first vibration generation module and the display module and a second gap disposed between the second vibration generation module and the display module.

[0011] According to an embodiment of the present application, a display device capable of accurate acoustic transmission can be provided, and a display device capable of improving sound quality and enhancing the immersion of viewers can be provided.

[0012] According to an embodiment of the present application, a display device capable of outputting sound in front of a display panel can be provided.

[0013] In addition to the effects of the present application described above, other features and advantages of the present application will be described below or will be clearly understood by those having ordinary knowledge in the technical field to which the present application pertains from such descriptions and explanations.

Brief Description of the Drawings

[0014]

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Mode for Carrying Out the Invention

[0015] The advantages and features of this application, and the ways to achieve them, will become clear by referring to the embodiments described in detail later together with the attached drawings. However, this application is not limited to the embodiments disclosed below, but can be embodied in various different forms. Merely these embodiments are provided to complete the disclosure of this application and to fully inform those with ordinary knowledge in the technical field to which this application belongs of the scope of the invention. This application is only defined by the claims.

[0016] The shapes, sizes, ratios, angles, numbers, etc. disclosed in the figures for explaining the embodiments of this application are exemplary, so this application is not limited to the matters shown in the figures. The same reference signs throughout the specification refer to the same components. Also, in explaining this application, when it is determined that a detailed description of related known technologies would unnecessarily obscure the gist of this application, that detailed description will be omitted.

[0017] When terms such as "including", "having", "consisting of", etc. mentioned in this specification are used, other parts can be added unless "only" is used. When a component is in the singular form, it includes the case where a plurality is included unless there are particularly explicit descriptions.

[0018] When interpreting a component, it is interpreted as including the range of error even without separate explicit descriptions.

[0019] In the case of an explanation of a positional relationship, for example, when the positional relationship between two parts such as "on ~", "above ~", "below ~", "next to ~" is described, unless "immediately" or "directly" is used, one or more other parts can also be located between the two parts.

[0020] In the case of an explanation regarding the relationship of time, for example, when the temporal sequence relationship is described by "after ~", "subsequent to ~", "next to ~", "before ~", etc., unless "immediately" or "directly" is used, the case where they are not consecutive can also be included.

[0021] The terms such as "first", "second", etc. are used to describe various components, but these components are not limited by these terms. These terms are only used to distinguish one component from another. Therefore, the first component described below may be the second component within the technical idea of this application.

[0022] The term "at least one" should be understood to include all combinations that can be presented from a plurality of related items. For example, the meaning of "at least one of the first item, the second item, and the third item" can mean not only each of the first item, the second item, or the third item alone, but also all combinations of items that can be presented from two or more of the first item, the second item, and the third item.

[0023] The features of each of several examples of this application can be partially or wholly combined or combined with each other, enabling various technical linkages and drives, and each example can be implemented independently of each other and can also be implemented together in a related relationship.

[0024] Hereinafter, an example of a display device according to this application will be described in detail with reference to the attached drawings. When adding reference signs to the components of each figure, for the same component, as long as it is shown on other figures, it can have the same sign as much as possible. And the scale of the configuration shown in the attached drawings has a different scale from the actual one for the convenience of explanation, so it is not limited to the scale shown in the figures.

[0025] The inventors of this application recognized the problems of general display devices and conducted various experiments to make the direction of sound propagation face the front side of the display panel when a user located in front of the display panel views an image. As a result, the sound quality can be improved. Therefore, through various experiments, the inventors of this application invented a display device that can generate sound that travels in the front region in front of the display panel and improve the sound quality.

[0026] FIG. 1 is a diagram showing a display device according to the present application.

[0027] Referring to FIG. 1, the display device according to the present application can output sounds (S1, S2, S3) by the vibration of a display module 100 configured to display an image. For example, in a display device, the display module 100 can vibrate by a vibration generating device (or a sound generating device) to generate sounds (S1, S2, S3). Most of the sounds (S1, S2) of the sounds (S1, S2, S3) generated by the vibration of the display module 100 can be directly output toward the front of the screen (FD) of the display device. Among the sounds (S1, S2, S3), the remaining sound (S3) is output to the side surface of the display device and can travel toward the front of the screen (FD). Therefore, the display device according to an embodiment of the present application uses the display module 100 as a diaphragm for sound generation and outputs sounds (S1, S2) in front of the screen (FD) of the display module 100, so that accurate sound transmission is possible, the sound quality is improved, and the immersion feeling of the viewer can be enhanced.

[0028] FIG. 2 is a diagram showing a vibration generating module disposed on a rear cover of the display device shown in FIG. 1. FIG. 3 is a schematic cross-sectional view of the line I-I' shown in FIG. 1. FIG. 4 is an enlarged view of the 'A' portion shown in FIG. 3.

[0029] Referring to FIGS. 2 to 4, the display device according to an embodiment of the present application can include a display module 100, a panel guide 200, a rear cover 300, a first vibration generating module 400, and a second vibration generating module 500.

[0030] The display module 100 can be, but is not limited to, a liquid crystal display module. For example, the display module 100 can be a display module such as a light-emitting display module, an electrophoretic display module, a micro light-emitting diode display module, an electronic wetting display module, or a quantum dot light-emitting display module.

[0031] The back (or rear surface) of the display module 100 can include an intermediate portion (CP) and end portions (or peripheral portions) (or edges or margins) (EP). For example, the back (or rear surface or back side) of the display module 100 can be divided into an intermediate portion (CP) and end portions (EP) that are parallel (or arranged side by side) with the intermediate portion (CP) therebetween.

[0032] The intermediate portion (CP) of the display module 100 can be divided into a first intermediate portion (C1) and a second intermediate portion (C2). For example, the first intermediate portion (C1) can be the left side portion (or left intermediate portion) of the intermediate portion (CP), and the second intermediate portion (C2) can be the right side portion (or right intermediate portion) of the intermediate portion (CP). The first intermediate portion (C1) and the second intermediate portion (C2) can be symmetric about the intermediate line (CL) of the display module 100 with respect to the first direction (X) (or horizontal direction) of the display module 100.

[0033] The display module 100 according to an embodiment of the present invention can include a display panel 110 and a backlight unit 130.

[0034] The display panel 110 can be configured to display an image using the light irradiated from the backlight unit 130. The display panel 110 can also serve as a diaphragm that vibrates by the vibration (or driving) of the first and second vibration generating modules 400 and 500 and outputs sounds (S1, S2) forward (FD). For example, the display panel 110 can output the first sound (S1) in the first sound range band due to the vibration of the first vibration generating module 400 and the second sound (S2) in the first and second sound range bands due to the vibration of the second vibration generating module 500 forward (FD) simultaneously or sequentially. The first sound range band can be different from the second sound range band. The first sound (S1) in the first sound range band can be output forward (FD) at the middle portion (CP) of the display panel 110, and the second sound (S2) in the second sound range band, which is higher than the first sound (S1) in the first sound range band, can be output forward (FD) from the edge portion (or peripheral portion) (or edge or end margin) (EP) of the display panel 110.

[0035] The display panel 110 according to an embodiment can include an upper substrate 111, a lower substrate 113, a lower polarizing member 115, and an upper polarizing member 117.

[0036] The upper substrate 111 is a first substrate or an array substrate of thin film transistors, and can include a pixel array (or display unit or display portion) having a plurality of pixels formed for each pixel region intersecting by a plurality of gate lines and a plurality of data lines. Each of the plurality of pixels can include a thin film transistor connected to the gate line and the data line, a pixel electrode connected to the thin film transistor, and a common electrode formed adjacent to the pixel electrode and supplied with a common voltage.

[0037] The upper substrate 111 can further include a pad portion provided at a first end (or periphery) (or first non-display portion) (or edge or end margin) and a gate driving circuit provided at a second end (or periphery) (or second non-display portion) (or edge or end margin).

[0038] The pad portion can supply signals supplied from the outside to the pixel array and the gate driving circuit. For example, it can include a plurality of data pads connected to a plurality of data lines via a plurality of data link lines of the pad portion, and a plurality of gate input pads connected to the gate driving circuit via a gate control signal line. As an example, the first end of the upper substrate 111 including the pad portion protrudes from the side surface corresponding to the first end of the lower substrate 113, and the pad portion can be exposed in the back direction toward the back cover 300. For example, the size of the upper substrate 111 can be larger than the size of the lower substrate 113, but is not limited thereto.

[0039] According to an embodiment, the gate driving circuit can be incorporated (or integrated) at the second end of the upper substrate 111 so as to be connected to the plurality of gate lines one-to-one. For example, the gate driving circuit can be a shift register including transistors formed by the same process as the thin film transistors provided in the pixel region.

[0040] The gate driving circuit according to another embodiment is not incorporated in the upper substrate 111, can be embodied in the form of an integrated circuit, and can also be included in the panel driving circuit.

[0041] The lower substrate 113 is a color filter array substrate, and can include a pixel definition pattern that can define an opening region overlapping each pixel region formed on the upper substrate 111, and a color filter layer formed in the opening region. According to an embodiment, the lower substrate 113 can have a size smaller than that of the upper substrate 111, but is not limited thereto. For example, the lower substrate 113 can overlap the remaining portion except the first end of the upper substrate 111. The lower substrate 113 can be bonded to the remaining portion except the first end of the upper substrate 111 with a liquid crystal layer sandwiched by a sealant.

[0042] The liquid crystal layer can be composed of liquid crystal whose alignment direction changes due to an electric field formed by a data voltage applied to the pixel electrode and a common voltage for each pixel, by being interposed between the upper substrate 111 and the lower substrate 113.

[0043] The lower polarizing member 115 can be attached to the lower surface of the lower substrate 113 to polarize the light incident from the backlight unit 130 and traveling through the liquid crystal layer.

[0044] The upper polarizing member 117 can be attached to the upper surface of the upper substrate 111 to polarize the light that passes through the upper substrate 111 and is emitted to the outside.

[0045] The display panel 110 according to one embodiment can display an image by the light passing through the liquid crystal layer by driving the liquid crystal layer by an electric field formed for each pixel by a data voltage and a common voltage applied for each pixel.

[0046] In the display panel 110 according to one embodiment, since the upper substrate 111 made of an array substrate of thin film transistors constitutes the video display surface, the entire front surface can be exposed to the outside without being blocked by a separate mechanism.

[0047] The embodiments of the present application are not limited to this. For example, in the display panel 110 according to other embodiments, the upper substrate 111 can be made of a color filter array substrate, and the lower substrate 113 can be made of an array substrate of thin film transistors. For example, in the display panel 110 according to other examples, the display panel 110 according to one embodiment can have a form in which it is upside down. As other embodiments, the pad portion of the display panel 110 according to other examples can be blocked by a separate mechanism or structure.

[0048] The display module 100 according to one embodiment can further include a buffer member 150.

[0049] The buffer member 150 can surround the side surface of the display panel 110 and cover each side surface and each corner of the display panel 110. The buffer member 150 can serve to protect the side surface of the display panel 110 from external impacts or to reduce or prevent light leakage from the side surface of the display panel 110. The buffer member 150 can be made of a silicone-based or ultraviolet (UV) curable sealing agent (or resin). In one embodiment, considering the process tact time, it can be made of an ultraviolet (UV) curable sealing agent. Also, the buffer member 150 can be colored (e.g., blue, red, cyan, or black), but is not limited thereto. For example, the buffer member 150 can be made of a colored resin or a light-blocking resin for preventing light leakage from the side surface.

[0050] In one embodiment, a part of the upper surface of the buffer member 150 can be covered by the upper polarizing member 117. For example, the upper polarizing member 117 can be extended long from the side surface corresponding to the outer surface of the upper substrate 111 so as to cover a part of the front surface of the buffer member 150 and can include an extension part attached to a part of the front surface of the buffer member 150. The joint surface (or attachment surface) (or the boundary part between the buffer member 150 and the upper substrate 111) may be hidden by the extension part of the upper polarizing member 117 and may not be exposed in front of the display device where the viewer is located. As an example where the buffer member 150 is not formed, the side surface of the display panel 110 is directly exposed in front of the display device (FD) without a separate mechanism, so a light leakage phenomenon may occur on the side surface of the display panel 110. Therefore, the buffer member 150 can be configured to prevent or reduce the light leakage phenomenon on the side surface of the display panel 110 and protect the side surface of the display panel 110 in a display device having a structure that exposes the entire front surface of the display panel 110 forward (FD) to reduce or minimize the bezel width of the display device as much as possible.

[0051] The backlight unit 130 is disposed on the back surface of the display panel 110 and can irradiate light on the back surface of the display panel 110.

[0052] In an embodiment of the present application, the backlight unit 130 includes a light guide plate 131, a light source unit, a reflective sheet 133, and an optical sheet unit 135.

[0053] The light guide plate 131 is disposed on the back cover 300 so as to overlap with the display panel 110, and includes a light incident surface provided on at least one side wall. The light guide plate 131 can include a light transmissive plastic or glass material. The light guide plate 131 causes the light incident from the light source unit through the light incident surface to travel (or emit light) toward the display panel 110. For example, the light guide plate 131 can be represented by a light guiding member or a planar light source, etc., and is not limited thereto.

[0054] The light source unit irradiates light on the light incident surface provided on the light guide plate 131. The light source unit can be disposed on the back cover 300 so as to overlap with the first end of the display panel 110. The light source unit according to an embodiment can include a plurality of light emitting diode elements (LEDs) mounted on a printed circuit board (PCB) for the light source to irradiate light on the light incident surface of the light guide plate 131.

[0055] The reflective sheet 133 can be disposed on the back cover 300 so as to cover the back surface of the light guide plate 131. The reflective sheet 133 can reduce or minimize light loss by reflecting the light incident from the light guide plate 131 back toward the light guide plate 131.

[0056] The optical sheet unit 135 is disposed on the front surface of the light guide plate 131 to improve the luminance characteristics of the light emitted from the light guide plate 131. The optical sheet unit 135 according to an example can include a lower diffusion sheet, a lower prism sheet, and an upper prism sheet. It is not limited thereto, and can be composed of one or more laminations selected from a diffusion sheet, a prism sheet, a double luminance enhancement film, and a lenticular sheet, or can be composed of a single composite sheet having a light diffusion and condensing function.

[0057] The panel guide 200 can support the end portion (EP) on the back side of the display panel 110. The panel guide 200 can be supported or stored on the back cover 300 so as to overlap with the end portion (EP) on the back side of the display panel 110. The panel guide 200 can be disposed under the end portion (EP) on the back side of the display panel 110 so as not to protrude outside each side surface of the display panel 110.

[0058] The panel guide 200 can include a panel support portion 210 and a guide side wall 230. For example, the panel guide 200 can have a cross-sectional structure in the shape of "┓" or "┏" by a coupling structure or a connecting structure between the panel support portion 210 and the guide side wall 230.

[0059] The panel support portion 210 can be coupled (or connected) to the end portion (EP) on the back of the display panel 110 and supported by the back cover 300. For example, the panel support portion 210 can have a rectangular strip shape having an opening (or hole or hole portion) that overlaps with the remaining intermediate portion (CP) excluding the end portion (EP) on the back of the display panel 110, but is not limited to this shape. The panel support portion 210 can have a size that is the same as or smaller than the size of the display panel 110 so as not to protrude outside each side surface of the display panel 110. For example, the hole of the panel support portion 210 can have the same size as or a larger size than the pixel array (or display portion) provided on the display panel 110.

[0060] The panel support portion 210 can be in direct contact with the uppermost surface of the backlight unit 130, for example, the uppermost surface of the optical sheet portion 135, or can be separated from the uppermost surface of the optical sheet portion 135 by a certain distance.

[0061] The guide side wall 230 is connected (or integrated) to the panel support portion 210 and wraps around the side surface of the back cover 300. For example, the guide side wall 230 can bend from the panel support portion 210 toward the side surface of the back cover 300 to surround the side surface of the back cover 300, or can be surrounded by the side surface of the back cover 300.

[0062] The panel guide 200 can be made of a plastic material, a metal material, or a mixed material of a plastic material and a metal material, and is not limited thereto. For example, the panel guide 200 can also serve as a vibration transmission member that transmits the sound vibration generated by the second vibration generating module 500 to the end portion (EP) of the display panel 110. Therefore, the panel guide 200 can transmit the sound vibration generated by the second vibration generating module 500 to the display panel 110 without loss while maintaining the rigidity of the display panel 110. For example, the panel guide 200 can include a metal material, and is not limited thereto, in order to transmit the sound vibration generated by the second vibration generating module 500 to the display panel 110 while maintaining the rigidity of the display panel 110.

[0063] The panel guide 200 can be coupled or connected to the end portion (EP) of the back surface of the display panel 110 via a first coupling member (or a first connecting member) 250.

[0064] The first connecting member 250 (or panel coupling member or first connecting member) is interposed between the end portion (EP) on the back side of the display panel 110 and the panel support portion 210 of the panel guide 200 to couple the display panel 110 to the panel guide 200. The first connecting member 250 according to an embodiment may include, but is not limited to, an acrylic-based or urethane-based adhesive member. For example, the first connecting member 250 may include, but is not limited to, an acrylic-based adhesive member having relatively excellent adhesive strength and high hardness so that the vibration of the panel guide 200 is well transmitted to the display panel 110. For example, the first connecting member 250 may include a double-sided foam adhesive pad having an acrylic-based adhesive layer or an acrylic-based adhesive resin cured layer.

[0065] The front surface of the first connecting member 250 according to an embodiment can be coupled (or connected) to the lower substrate 113 or the lower polarizing member 115 of the display panel 110. For example, in order to improve the adhesive force with the display panel 110, it can be directly coupled (or connected) to the end portion (EP) on the back surface of the lower substrate 113. The first connecting member 250 can prevent side light leakage generated in the lower polarizing member 115 by adhering to the end portion (EP) on the back side of the lower substrate 113 and surrounding the side surface of the lower polarizing member 115.

[0066] The first connecting member 250 can provide a sound transmission space (STS) between the display panel 110 and the panel guide 200 so as to have a certain thickness (or height). The first connecting member 250 according to an embodiment can be formed in a four-side sealed or closed-loop form on the panel support portion 210 of the panel guide 200, but is not limited thereto. For example, the first connecting member 250 can provide a sealed sound transmission space (STS) between the rearmost surface of the display panel 110 facing each other across the hole of the panel guide 200 and the uppermost surface of the backlight unit 130, thereby preventing, reducing, or minimizing the leakage (or loss) of the sound pressure transmitted to the sound transmission space (STS). The sound transmission space (STS) can serve as a sound pressure generation space where sound pressure is generated by the vibration of the backlight unit 130 or a panel vibration space that smooths the vibration of the display panel 110 by the sound pressure.

[0067] The rear cover 300 can be configured to support the panel guide 200 and can cover the rear surface of the display module 100. Also, the rear cover 300 can be configured to support the first and second vibration generating modules 400 and 500. The rear cover 300 can serve as a diaphragm and can include a metal material or a metal alloy material. For example, the rear cover 300 can be made of any one of aluminum (Al) material, magnesium (Mg) alloy material, magnesium lithium (Li) alloy material, and aluminum (Al) alloy material, but is not limited thereto.

[0068] The rear cover 300 can further include a rear cover portion 310 configured to support the rear surface of the display module 100, and a side cover portion 330 connected or / and integrated with the end portion (EP) of the rear cover portion 310 to support the panel guide 200.

[0069] The rear cover part 310 is arranged to cover the rear surface of the display module 100 and can support the display module 100. The rear cover part 310 has a plate-like structure, can support the backlight unit 130 of the display module 100, and can support each of the first vibration generating module 400 and the second vibration generating module 500. For example, the rear cover part 310 can serve to transmit the sound vibrations generated by the vibrations of each of the first vibration generating module 400 and the second vibration generating module 500 to the reflection sheet 133 of the backlight unit 130 by directly contacting the rear surface of the reflection sheet 133.

[0070] The rear cover part 310 can include an intermediate region (MA) corresponding (or overlapping) to the intermediate part (CP) of the display module 100 and an end region (EA) corresponding (or overlapping) to the end part (EP) of the display module 100.

[0071] In an embodiment of the present application, the intermediate region (MA) (or the first cover region) of the rear cover part 310 can include a first intermediate region (MA1) (or the left intermediate region) corresponding (or overlapping) to the first intermediate part (C1) of the display module 100 and a second intermediate region (MA2) (or the right intermediate region) corresponding (or overlapping) to the second intermediate part (C2) of the display module 100, based on the intermediate line (CL) of the display module 100. Each of the first intermediate region (MA1) and the second intermediate region (MA2) of the rear cover part 310 can include a first support region (SA1) for supporting the first vibration generating module 400. For example, the central part of the first support region (SA1) can be located on the horizontal line (HL) (or the intermediate horizontal line) of the display module 100, above the horizontal line (HL) along the second direction (Y) (or the vertical direction), or below it.

[0072] The end region (EA) (or the second cover region) of the rear cover portion 310 can include a second support region (SA2) for supporting the second vibration generating module 500. For example, the central portion of the second support region (SA2) can be located on the horizontal line (HL) (or the intermediate horizontal line) of the display module 100 with respect to the second direction (Y). The central portion of the first support region (SA1) can be located on the horizontal line (HL) of the display module 100, or can be spaced above or below the horizontal line (HL) along the second direction (Y), similar to the central portion of the second support region (SA2).

[0073] In FIG. 4, an example in which the rear cover portion 310 is in close contact with the backlight unit 130 is shown, but it is not limited thereto. For example, the rear cover portion 310 can be spaced apart from the backlight unit 130 by a predetermined space, and an air layer can be formed in the spaced-apart space. According to one embodiment, the spaced-apart space between the rear cover portion 310 and the backlight unit 130 can be disposed in the intermediate portion (CP) of the display module 100.

[0074] The rear cover portion 310 according to an embodiment of the present application can include a rear cover hole 311 (or the first rear cover hole). The rear cover hole 311 can be spaced apart from a part of the first vibration generating module 400 and can be in the intermediate region (MA) of the rear cover portion 310 corresponding to the intermediate portion (CP) of the display module 100. The rear cover hole 311 can be formed to penetrate the rear cover portion 310 along the thickness direction (Z) of the rear cover portion 310 in the intermediate region (MA) of the rear cover portion 310. For example, the rear cover hole 311 can be disposed between the first support region (SA1) and the second support region (SA2) in the region of the rear cover portion 310. The rear cover hole 311 can have a circular form, but is not limited thereto. The rear cover hole 311 can be expressed as an opening hole, a hole portion, a duct hole, or a resonance hole, etc., but is not limited thereto.

[0075] The rear cover hole 311, rear cover part 310, first vibration generation module 400, and system rear cover 600 according to the present application form a Helmholtz resonator, and the Helmholtz resonator can reduce noise characteristics for low frequencies. A detailed description of the Helmholtz resonator formed by the rear cover hole 311, rear cover part 310, first vibration generation module 400, and system rear cover 600 will be described later with reference to FIGS. 9 and 10.

[0076] Also, according to an embodiment of the present application, the rear cover 300 may further include a first hole 313 and a second hole 315.

[0077] The first hole 313 (or the first through hole or the second rear cover hole) is disposed in the first rear region of the rear cover 300 that overlaps with the first vibration generation module 400 and can be covered by the reflection sheet 133 of the backlight unit 130. For example, the first hole 313 may be provided in the middle region (MA) of the rear cover part 310. The first hole 313 may be formed to penetrate the first support region (SA1) of the rear cover part 310 in the middle region (MA) of the rear cover part 310 along the thickness direction (Z) of the rear cover part 310.

[0078] The first hole 313 can provide a first gap between the backlight unit 130 and the first vibration generation module 400. For example, the first gap can be represented by a vibration space associated with the driving of the first vibration generation module 400, a sound pressure space (or a resonance part or a resonance portion) where sound pressure is generated by the vibration of the first vibration generation module 400, or a sound wave propagation path (or an acoustic energy incident portion) where sound waves generated by the vibration of the first vibration generation module 400 are directly transmitted to the display module 100, and is not limited thereto.

[0079] The size (or width) of the first hole 313 according to one embodiment can be smaller than the size of the first vibration generating module 400. If the overall size (or overall width) of the first hole 313 is larger than the overall size of the first vibration generating module 400, when the first vibration generating module 400 is inserted (or penetrated or accommodated) into the first hole 313, without using a separate mechanism, it becomes impossible to arrange the first vibration generating module 400 on the back cover portion 310. Therefore, when the overall size of the first hole 313 is smaller than the overall size of the first vibration generating module 400, the first vibration generating module 400 can be arranged on the back cover portion 310 so as to overlap the first hole 313 without a separate mechanism. For example, the first hole 313 according to one example can have the same form as the first vibration generating module 400 or can have a rectangular form (e.g., quadrilateral) or a circular form, and is not limited thereto.

[0080] The second hole 315 (or the second through hole or the third back cover hole) can be arranged in the second back region of the back cover 300 that overlaps with the second vibration generating module 500 and can be covered by the reflection sheet 133 of the backlight unit 130. For example, the second hole 315 can be provided in the end region (EA) of the back cover portion 310. The second hole 315 can be formed to penetrate the second support region (SA2) of the back cover portion 310 in the end region (EA) of the back cover portion 310 along the thickness direction (Z) of the back cover portion 310.

[0081] The second hole 315 can provide a second gap space between the backlight unit 130 and the second vibration generating module 500. For example, the second gap space can be represented by a vibration space associated with the driving of the second vibration generating module 500, a sound pressure space (or a resonant portion or a resonance portion) where sound pressure is generated by the vibration of the second vibration generating module 500, or a sound wave propagation path (or an acoustic energy incident portion) where sound waves generated by the vibration of the second vibration generating module 500 are directly transmitted to the display module 100, and is not limited thereto.

[0082] The size (or width) of the second hole 315 according to an embodiment can be smaller than the size of the second vibration generating module 500. When the overall size (or overall width) of the second hole 315 is larger than the overall size of the second vibration generating module 500, when the second vibration generating module 500 is inserted (or penetrated or accommodated) into the second hole 315, without using a separate mechanism, the second vibration generating module 500 cannot be arranged on the rear cover portion 310 so as to overlap with the second hole 315. Therefore, when the overall size of the second hole 315 is smaller than the overall size of the second vibration generating module 500, the second vibration generating module 500 can be arranged on the rear cover portion 310 so as to overlap with the second hole 315 without a separate mechanism. For example, the second hole 315 according to an example can have the same form as the second vibration generating module 500 or can have a rectangular form or a circular form, and is not limited thereto.

[0083] The side cover portion 330 can be bent from the end of the rear cover portion 310 to support the panel guide 200. The side cover portion 330 provides a backlight storage space (or space) on the rear cover portion 310 and surrounds the side surface of the backlight unit 130 stored (or supported) in the backlight storage space. The side cover portion 330 can also serve to transmit the sound vibration generated in the rear cover portion 310 to the panel guide 200 by the second vibration generating module 500.

[0084] The rear cover 300 can further include a reinforcing portion 350. Since the reinforcing portion 350 can reinforce the rigidity of the rear cover 300, it can be a rigidity reinforcing portion, but is not limited thereto.

[0085] The reinforcing portion 350 may be formed in a region (or connection region) where the back cover portion 310 and the side cover portion 330 intersect. As an example, the reinforcing portion 350 may be formed along an end region (or peripheral region) (EA) of the back cover portion 310. For example, the reinforcing portion 350 may protrude in the back direction so as to have an inclined surface inclined from the end of the back cover portion 310. When the back cover 300 includes the reinforcing portion 350, the side cover portion 330 may be connected and / or integrated with an end portion of the reinforcing portion 350.

[0086] The first vibration generating module 400 is disposed in a first back region of the back cover 300 and can vibrate a first region of the display module 100. For example, the first back region of the back cover 300 may overlap with an intermediate portion (CP) or an end portion (EP) of the display module 100, and the first region of the display module 100 may be the intermediate portion (CP) or the end portion (EP).

[0087] The first vibration generating module 400 according to an example of the present application is disposed in an intermediate region (MA) of the back cover 300 and can vibrate an intermediate portion (CP) of the display module 100. The first vibration generating module 400 can generate a sound pressure between the display module 100 and the back cover 300 at the intermediate portion (CP) of the display module 100. The first vibration generating module 400 generates a sound pressure between the display module 100 and the back cover 300, and by this sound pressure, the intermediate portion (CP) of the display module 100 can be vibrated to generate a first sound (S1) in a first sound range band at the intermediate portion (CP) of the display module 100. The first sound (S1) in the first sound range band according to an example can have a frequency in a low sound range band. For example, the low sound range band may be 200 Hz or less, but is not necessarily limited thereto and may be 3 kHz or less.

[0088] The first vibration generating module 400 according to an embodiment can be coupled or disposed in an intermediate region (MA) of the back cover portion 310 of the back cover 300. For example, the first vibration generating module 400 can be coupled or disposed in a first support region (SA1) of the intermediate region (MA) of the back cover portion 310. Accordingly, the first vibration generating module 400 can generate sound pressure by vibrating the intermediate region (MA) of the back cover portion 310 in response to an acoustic signal (or voice signal) input from the outside, and vibrate the intermediate portion (CP) of the display module 100 through this sound pressure to generate a first sound (S1) in a first sound range band. As an example, the first vibration generating module 400 can include, but is not limited to, a sound actuator or a sound exciter, and can be implemented as an acoustic generating device using a coil (or voice coil) and a magnet.

[0089] The first vibration generating module 400 according to an embodiment can include a first sound generating unit 410 and a second sound generating unit 430.

[0090] The first sound generating unit 410 can vibrate a first intermediate portion (C1) of the intermediate portion (CP) of the display module 100 to output a first sound (S1) in a first sound range band to the front (FD) of the display panel 110. The first sound generating unit 410 can be disposed in a first support region (SA1) of a first intermediate region (MA1) of the intermediate region (MA) of the back cover portion 310. For example, the first sound generating unit 410 can be disposed or coupled to the back cover portion 310 so as to cover a first hole 313 formed in the first support region (SA1) of the first intermediate region (MA1) of the back cover portion 310.

[0091] According to one embodiment, the first acoustic generating unit 410 vibrates the first intermediate region (MA1) of the rear cover portion 310 in response to an acoustic signal, generating a sound pressure inside the first hole 313 (or the first gap), thereby vibrating the first intermediate portion (C1) of the display module 100 and generating the first sound (S1) in the first sound range band. For example, when the first acoustic generating unit 410 vibrates due to an acoustic signal, the vibration of the first intermediate region (MA1) of the rear cover portion 310 caused by the vibration of the first acoustic generating unit 410 generates a sound pressure inside the first hole 313. The vibration of the backlight unit 130 caused by this sound pressure generates a sound pressure in the sound transmission space (STS). The first sound (S1) in the first sound range band generated by the vibration of the first intermediate portion (C1) of the display panel 110 due to the sound pressure generated in the sound transmission space (STS) can be output in front (FD) of the display panel 110. Therefore, the sound wave generated by the vibration of the first acoustic generating unit 410 is directly transmitted (or propagated) to the display module 100 through the first hole 313, so that the sound pressure characteristics and sound quality of the first sound (S1) can be improved.

[0092] The second acoustic generating unit 430 can vibrate the second intermediate portion (C2) among the intermediate portions (CP) of the display module 100 and output the first sound (S1) in the first sound range band in front (FD) of the display panel 110. The second acoustic generating unit 430 can be disposed in the first support region (SA1) of the second intermediate region (MA2) among the intermediate regions (MA) of the rear cover portion 310. As an example, the second acoustic generating unit 430 can be disposed or coupled to the rear cover portion 310 so as to cover the first hole 313 formed in the first support region (SA1) of the second intermediate region (MA2) of the rear cover portion 310.

[0093] According to an embodiment, the second acoustic generating unit 430 vibrates the second intermediate region (MA2) of the rear cover portion 310 in response to an acoustic signal, generates a sound pressure inside the first hole 313 (or the first gap), thereby vibrating the second intermediate portion (C2) of the display module 100, and generating the first sound (S1) in the first sound range band. For example, when the second acoustic generating unit 430 vibrates due to an acoustic signal, the vibration of the second intermediate region (MA2) of the rear cover portion 310 due to the vibration of the second acoustic generating unit 430 generates a sound pressure inside the first hole 313, the sound pressure generated by the vibration of the backlight unit 130 due to this sound pressure generates a sound pressure in the sound transmission space (STS), and the first sound (S1) in the first sound range band generated by the vibration of the second intermediate portion (C2) of the display panel 110 due to the sound pressure generated in the sound transmission space (STS) can be output to the front (FD) of the display panel 110. Therefore, the sound wave generated by the vibration of the second acoustic generating unit 430 is directly transmitted (or propagated) to the display module 100 through the first hole 313, so that the sound pressure characteristics and sound quality of the first sound (S1) can be improved.

[0094] The positions of the first acoustic generating unit 410 and the second acoustic generating unit 430 according to an embodiment can be adjusted by the harmony with the sound generated by the vibration of the first acoustic generating unit 410 and the second acoustic generating unit 430 or the realization of stereo sound. For example, the respective arrangement positions of the first and second acoustic generating units 410 and 430 can have a symmetric structure centered on the intermediate line (CL) of the display module 100 or be arranged asymmetrically with respect to the first direction (X) (or the horizontal direction) of the display module 100.

[0095] The first vibration generating module 400 can include only one acoustic generating unit 410 arranged at the center of the rear cover portion 310 so that the low-frequency sound (S1) generated by the vibration of the display panel 110 corresponding to the vibration of the rear cover portion 310 is directly transmitted to the listener through the air, and the embodiment is not necessarily limited thereto.

[0096] The second vibration generating module 500 is disposed in the second back region of the back cover 300 and can vibrate the second region of the display module 100. For example, the second back region of the back cover 300 may be the portion excluding the first back region among the middle portion (CP) and the end portion (EP) of the display module 100, and the second region of the display module 100 may be the portion excluding the first region among the middle portion (CP) and the end portion (EP). For example, the second back region of the back cover 300 may be the portion excluding the region overlapping the first back region from the middle portion (CP) and the end portion (EP) of the display module 100, and the second region of the display module 100 may be the portion excluding the first region from the middle portion (CP) and the end portion (EP) of the display module 100.

[0097] The second vibration generating module 500 is disposed in the end region (EA) of the back cover 300 and can vibrate the end portion (or peripheral portion) (EP) of the display module 100. The second vibration generating module 500 can generate sound vibrations in the end portion (EP) of the display module 100. The second vibration generating module 500 can generate a first sound (S1) in a first sound range band generated in the middle portion (CP) of the display module 100 and a second sound (S2) in another second sound range band in the end portion (EP) of the display module 100. The second sound (S2) in a second sound range band according to an example can have frequencies in the mid-high sound range band or the high sound range band. For example, it can be in the mid sound range band of 200 Hz to 3 kHz, and is not necessarily limited thereto, and can be 3 kHz to 5 kHz. The high sound range band can be 3 kHz or more, and is not necessarily limited thereto, and can be 5 kHz or more.

[0098] The second vibration generation module 500 according to an embodiment can be coupled or disposed in the end region (EA) of the back cover portion 310 of the back cover 300. For example, the second vibration generation module 500 can be coupled or disposed in the second support region (SA2) in the end region (EA) of the back cover portion 310. Accordingly, the second vibration generation module 500 can generate sound vibrations by vibrating the end region (EA) of the back cover portion 310 in response to an acoustic signal (or voice signal) input from the outside, and vibrate the end portion (EP) of the display module 100 through this sound vibration to generate a second sound (S2) in the second sound range band. The second vibration generation module 500 can include a piezoelectric element or a piezoelectric material having a piezoelectric effect (or inverse piezoelectric characteristic).

[0099] The second vibration generation module 500 can include a first piezoelectric vibration unit 510 and a second piezoelectric vibration unit 530.

[0100] The first piezoelectric vibration unit 510 can vibrate the first end portion (EP1) (or the left end portion or the portion closer to the left end) of the end portion (EP) of the display module 100 and output a second sound (S2) in the second sound range band in front (FD) of the display panel 110. The first piezoelectric vibration unit 510 can be disposed in the second support region (SA2) in the first end region (or the left end region or the portion closer to the left end) (EA1) of the end region (EA) of the back cover portion 310. For example, the first piezoelectric vibration unit 510 can be disposed or coupled to the back cover portion 310 so as to cover the second hole 315 formed in the second support region (SA2) in the first end region (EA1) of the back cover portion 310.

[0101] According to an embodiment, the first piezoelectric vibration unit 510 can generate a second sound (S2) in a second sound range band from the first end portion (EP1) of the display panel 110 by vibrating the first end region (EA1) of the back cover portion 310 in response to an acoustic signal to acoustically vibrate the first end portion (EP1) of the display panel 110. For example, when the first piezoelectric vibration unit 510 vibrates by an acoustic signal, the acoustic vibration generated in the first end region (EA1) of the back cover portion 310 due to the vibration of the first piezoelectric vibration unit 510 is transmitted to the first end portion (EP1) of the display panel 110 through the side cover portion 330 of the back cover 300 and the panel guide 200, and the second sound (S2) generated by the vibration of the first end portion (EP1) of the display panel 110 due to the acoustic vibration transmitted through the panel guide 200 can be output to the front (FD) of the display panel 110. Therefore, the sound wave generated by the vibration of the first piezoelectric vibration unit 510 is directly transmitted (or propagated) to the first end portion (EP1) of the display module 100 through the second hole 315, so that the sound pressure characteristics and sound quality of the second sound (S2) can be improved, and the sound pressure characteristics and sound quality of the second sound (S2) can be further improved by reducing the vibration of the first end region (EA1) of the back cover portion 310 due to the vibration of the first piezoelectric vibration unit 510.

[0102] According to an embodiment, the first piezoelectric vibration unit 510 can be arranged to be close to the side cover portion 330 of the back cover 300 so that the high-pitched second sound (S2) generated by the acoustic vibration of the first end portion (EP1) of the display panel 110 corresponding to the acoustic vibration of the first end region (EA1) of the back cover portion 310 is directly transmitted to the listener. For example, the first piezoelectric vibration unit 510 can be arranged in the first end region (EA1) of the back cover portion 310 so as to overlap with the panel support portion 210 of the panel guide 200 that supports the second end portion (EP1) of the display panel 110.

[0103] According to one example, the first piezoelectric vibration unit 510 can be disposed on the horizontal line (or the intermediate horizontal line) (HL) of the back cover portion 310 with reference to the length direction (or the longitudinal direction) of the back cover portion 310 parallel to the second direction (Y). For example, the first acoustic generation unit 410 of the first vibration generation module 400 according to one example can be disposed on the same line as the first piezoelectric vibration unit 510 or above or below the horizontal line (or the intermediate horizontal line) (HL) parallel to the first direction (X) with reference to the second direction (Y). As an example, the central portion of the first acoustic generation unit 410 can be disposed on the horizontal line (or the intermediate horizontal line) (HL) extended from the central portion of the first piezoelectric vibration unit 510 so as to be parallel to the first direction (X). As another example, the central portion of the first acoustic generation unit 410 can be disposed below or above the horizontal line (or the intermediate horizontal line) (HL) with reference to the second direction (Y). The central portion of the first acoustic generation unit 410 can be disposed below the horizontal line (or the intermediate horizontal line) (HL) rather than above the horizontal line (or the intermediate horizontal line) (HL) with reference to the second direction (Y) so that the first sound (S1) of the bass generated by the vibration of the first intermediate portion (C1) among the intermediate portions (CP) of the display module 100 is directly transmitted to the listener.

[0104] The first piezoelectric vibration unit 510 according to one embodiment can include a first piezoelectric element 511 attached to the back cover portion 310 via a first adhesive member 513.

[0105] The first piezoelectric element 511 can include a piezoelectric material layer having a piezoelectric effect.

[0106] The piezoelectric material layer can include a piezoelectric material that generates vibration by an electric field. The piezoelectric material has a property that a potential difference is generated by dielectric polarization accompanying a change in the relative positions of positive (+) ions and negative (-) ions while a pressure or a torsional phenomenon acts on the crystal structure by an external force, and vibration is generated by an electric field due to a voltage applied in the opposite direction.

[0107] The piezoelectric material layer according to an embodiment can include a piezoelectric material of a polymer material, a piezoelectric material of a thin film material, a piezoelectric material of a composite material, or a piezoelectric material of a single crystal ceramic or a polycrystalline ceramic. The piezoelectric material of the polymer material according to an embodiment can include PVDF (polyvinylidene fluoride), P(VDF-TrFe) (poly(vinylidene fluoride-trifluoroethylene)), or P(VDFTeFE) (poly(vinylidene fluoride-tetrafluoroethylene)). The piezoelectric material of the thin film material according to an embodiment can include ZnO, CdS, or AlN. The piezoelectric material of the composite material according to an example can include PZT (lead zirconate titanate)-PVDF, PZT-silicon rubber, PZT-epoxy, PZT-foam polymer, or PZT-foam urethane. The piezoelectric material of the single crystal ceramic according to an embodiment can include aluminum phosphate (e.g., berlinite, α-AlPO4), silicon dioxide (e.g., α-SiO2), lithium niobate (LiNbO3), terbium molydbate (Tb2(MoO4)3), lithium tetraborate (Li2B4O7), or ZnO. The piezoelectric material of the polycrystalline ceramic according to an embodiment can include a PZT-based, a PT-based, a PZT-complex perovskite-based, or barium titanate (BaTiO3).

[0108] The first piezoelectric element 511 according to an embodiment can have a first length along the first direction (X) and a second length along the second direction (Y). For example, the first length of the first piezoelectric element 511 may be shorter than the second length, not necessarily limited thereto, and may be the same as or longer than the second length.

[0109] The first bonding member 513 can be a double-sided tape or a natural-curing adhesive, but is not limited thereto. For example, the first bonding member 513 can be made of a thermosetting adhesive or a photocuring adhesive. As an example, the characteristics of the first piezoelectric element 511 may be degraded by the heat in the curing process of the first bonding member 513.

[0110] The first piezoelectric vibration unit 510 according to one embodiment can further include a first protection member 515 attached to the back surface of the first piezoelectric element 511.

[0111] The size of the first protection member 515 is formed to be larger than that of the first piezoelectric element 511 and can be attached to the back surface of the first piezoelectric element 511. The first protection member 515 can prevent damage to the first piezoelectric element 511 due to electrical shocks such as static electricity and / or physical shocks. For example, the first piezoelectric element 511 may be damaged by static electricity generated in the display module 100 such as a panel drive circuit section or flowing in from the outside, or may be damaged by physical contact with the display module 100 when the display module 100 is pushed. Thereby, by disposing the first protection member 515 between the display module 100 and the first piezoelectric element 511, the static electricity transmitted to the first piezoelectric element 511 through the display module 100 can be blocked, and the first piezoelectric element 511 can be protected from static electricity. Therefore, the first protection member 515 can protect the first piezoelectric element 511 from static electricity and can also protect the first piezoelectric element 511 from physical shocks applied to the first piezoelectric element 511. The first protection member 515 according to one embodiment can include a single-sided insulating tape or an insulating single-sided foam tape having an adhesive layer attached to the back surface of the first piezoelectric element 511. For example, the first protection member 515 can be a PET (polyethylene terephthalate) insulating tape or a PVC (polyvinyl chloride) insulating tape.

[0112] The second piezoelectric vibration unit 530 can vibrate the second end portion (EP2) (or the right end portion or the portion closer to the right end) of the end portion (EP) of the display module 100 to output the second sound (S2) in the second sound range band in front (FD) of the display panel 110. The second piezoelectric vibration unit 530 can be disposed in the second support region (SA2) in the second end region (EA2) (or the right end region or the portion closer to the right end) of the end region (EA) of the rear cover portion 310. For example, the second piezoelectric vibration unit 530 can be disposed on or coupled to the rear cover portion 310 so as to cover the second hole 315 formed in the second support region (SA2) of the second end region (EA2) of the rear cover portion 310.

[0113] The second piezoelectric vibration unit 530 according to an embodiment vibrates the second end region (EA2) of the rear cover portion 310 in response to an acoustic signal to vibrate the second end portion (EP2) of the display panel 110 acoustically, thereby generating the second sound (S2) in the second sound range band at the second end portion (EP2) of the display panel 110. For example, when the second piezoelectric vibration unit 530 vibrates by an acoustic signal, the acoustic vibration generated in the second end region (EA2) of the rear cover portion 310 due to the vibration of the second piezoelectric vibration unit 530 is transmitted to the second end portion (EP2) of the display panel 110 via the side cover portion 330 of the rear cover 300 and the panel guide 200, and the second sound (S2) generated by the vibration of the second end portion (EP2) of the display panel 110 due to the acoustic vibration transmitted via the panel guide 200 can be output in front (FD) of the display panel 110. Therefore, the sound wave generated by the vibration of the second piezoelectric vibration unit 530 is directly transmitted (or propagated) to the second end portion (EP2) of the display module 100 via the second hole 315, so that the sound pressure characteristics and the sound quality of the second sound (S2) can be improved, and the sound pressure characteristics and the sound quality of the second sound (S2) can be further improved by the reduction of the vibration of the second end region (EA2) of the rear cover portion 310 due to the vibration of the second piezoelectric vibration unit 530.

[0114] The second piezoelectric vibration unit 530 according to an embodiment may be disposed in the second end region (EA2) of the back cover portion 310 so as to be symmetric with the first piezoelectric vibration unit 510 about the intermediate line (CL) of the display module 100, or may be disposed at another position.

[0115] The positions of the first piezoelectric vibration unit 510 and the second piezoelectric vibration unit 530 according to an embodiment may be set by the harmony with the sound generated by the vibrations of the first piezoelectric vibration unit 510 and the second piezoelectric vibration unit 530 or the realization of stereophonic sound. For example, when the respective arrangement positions of the first piezoelectric vibration unit 510 and the second piezoelectric vibration unit 530 are based on the first direction (X) (or the horizontal direction) of the display module 100, they may have a symmetric structure about the intermediate line (CL) of the display module 100 or may be arranged asymmetrically.

[0116] The second piezoelectric vibration unit 530 according to an embodiment may include a second piezoelectric element 531 attached to the back cover portion 310 via a second adhesive member 533.

[0117] The second piezoelectric element 531 may include a piezoelectric material layer having a piezoelectric effect. Since the second piezoelectric element 531 has substantially the same configuration (or structure) as the first piezoelectric element 511 of the first piezoelectric vibration unit 510, duplicate description can be omitted.

[0118] The second adhesive member 533 may be a double-sided tape or a natural-curing adhesive, and is not limited thereto. The second adhesive member 533 may also be a thermosetting adhesive or a photo-curing adhesive. For example, the characteristics of the second piezoelectric element 531 may be degraded by the heat of the curing process of the second adhesive member 533.

[0119] The second piezoelectric vibration unit 530 according to an embodiment may further include a second protection member 535 attached to the back surface of the second piezoelectric element 531.

[0120] The size of the second protective member 535 is formed to be larger than that of the second piezoelectric element 531 and can be attached to the back surface of the second piezoelectric element 531. The second protective member 535 prevents damage to the second piezoelectric element 531 caused by electrical shocks such as static electricity and / or physical shocks. Since it has substantially the same configuration (or structure) as the first protective member 515, duplicate description thereof will be omitted.

[0121] The display device according to the present application may further include a system back cover 600 disposed on the back surface of the back cover 300. The system back cover 600 can house the display module 100 to which the first and second vibration generating modules 400 and 500 are respectively coupled or connected, and can wrap the side surface of the display module 100. For example, the system back cover 600 can be expressed as a "set" cover, a "back set" cover, an "outermost set" cover, a "product" cover, or an "outermost product" cover, etc., and is not limited thereto.

[0122] The system back cover 600 according to an embodiment may include a back structure 610 and a side structure 630. The back structure 610 is the outermost back mechanism located on the back surface of the display device, and can support (or house) the display module 100 and cover the back surface of the display module 100.

[0123] The side structure 630 is the outermost surface mechanism located on the side surface of the display device, and can be connected and / or integrated with the end of the back structure 610 to cover the side surface of the display module 100.

[0124] FIG. 5a is a diagram showing the system back cover shown in FIG. 1, and FIG. 5b is an enlarged view of a duct disposed on the system back cover of FIG. 5a.

[0125] When FIGS. 5a and 5b are associated with FIG. 4, in the system rear cover 600 according to an embodiment of the present application, the rear structure 610 of the system may further include a system rear cover box 611 that can accommodate the first vibration generating module 400 and the rear cover hole 311.

[0126] The system rear cover box 611 may be embodied on the inner surface of the system rear structure 610 so as to entirely surround the first vibration generating module 400 and the rear cover hole 311. The system rear cover box 611 can improve the sound pressure generated by the first vibration generating module 400, amplify the first sound in the first sound range band, and improve the characteristics of the first sound by providing a space (or a sealed space) between the rear cover part 310 and the system rear structure 610. The system rear cover box 611 can be coupled (or connected) to the rear cover part 310 to define or seal the space around the first vibration generating module 400, thereby separating the space around the first vibration generating module 400 from other spaces on the back of the rear cover part 310. The peripheral space on the back of the first vibration generating module 400 can amplify the bass generated by the vibration of the first vibration generating module 400.

[0127] The system rear cover box 611 may be coupled or connected to the rear cover part 310 of the rear cover 300 and may be a partition that acoustically seals or separates the space in which the first vibration generating module 400 and the rear cover hole 311 are disposed. Thereby, the present application can utilize the bass generated by the first vibration generating module 400, and the resonance effect inside the system rear cover box 611 can amplify the sound pressure generated by the first vibration generating module 400. For example, the system rear cover box 611 can be expressed as an "acoustic box", a "resonator", or a "resonance part", etc., but is not limited thereto.

[0128] As shown in FIG. 4, a display device according to an embodiment of the present application may further include a sealing member 700 that more tightly seals the joint portion (or contact portion or connection portion) between the system rear cover box 611 and the rear cover portion 310.

[0129] The sealing member 700 can acoustically seal the joint portion between the system rear cover box 611 and the rear cover portion 310.

[0130] The sealing member 700 according to one embodiment may be provided in a form that covers the joint portion (or connection portion) between the system rear cover box 611 and the rear cover portion 310. The sealing member 700 according to another example can be inserted or housed at least partially in the joint portion between the system rear cover box 611 and the rear cover portion 310, thereby filling the gap formed in the joint portion between the system rear cover box 611 and the rear cover portion 310, and further improving the sealing performance between the system rear cover box 611 and the rear cover portion 310. As a result, the space formed between the system rear cover box 611 and the rear cover portion 310 can provide an air layer that can improve the bass generated by the first vibration generating module 400, prevent or reduce the leakage (or loss) of sound pressure, and minimize it as much as possible.

[0131] The sealing member 700 according to one embodiment may be made of a silicon-based or ultraviolet (UV) curable sealing agent (or resin), or may be made of an ultraviolet (UV) curable sealing agent, and is not necessarily limited thereto. For example, any material that can acoustically seal the joint portion between the system rear cover box 611 and the rear cover portion 310 can be used without limitation.

[0132] The system rear cover 600 according to an embodiment of the present application may further include a system rear cover duct 631.

[0133] The system rear cover duct 631 can amplify bass through the air flow generated by the vibration of the first vibration generating module 400. The system rear cover duct 631 can amplify bass through the air flow generated during the vibration of the first vibration generating module 400 in the reverse direction (or the rear direction) and output it externally. For example, if the system rear cover duct 631 is not formed on the system rear cover 600, the air flow generated each time the first vibration generating module 400 vibrates in the reverse direction may cancel each other out or be lost. On the other hand, when the system rear cover duct 631 is formed on the system rear cover 600, the air flow generated each time the first vibration generating module 400 vibrates in the reverse direction can be smoothed by the system rear cover duct 631, and the air flow will not cancel each other out or be lost and can be utilized to amplify bass. Therefore, this application can utilize the system rear cover duct 631 to use the air generated each time the first vibration generating module 400 vibrates in the reverse direction for bass amplification, thereby improving or maximizing the sound pressure characteristics of the bass as much as possible. For example, the system rear cover duct 631 can be represented by an acoustic discharge hole or a vent hole, etc., but is not limited thereto.

[0134] The system rear cover duct 631 according to one embodiment can be formed on at least a part of the side structure 630 of the system rear cover 600. As an example, the side structure 630 can have first to fourth side walls, and the system rear cover duct 631 can be formed on the first side wall (or the lower part) facing the ground among the first to fourth side walls of the side structure 630, but is not necessarily limited thereto. For example, the system rear cover duct 631 can be formed on at least one of the first to fourth side walls of the side structure 630 by the harmony of the acoustics generated by the first vibration generating module 400 and the second vibration generating module 500 or the realization of stereophonic sound.

[0135] FIG. 6 is a diagram showing the first and second acoustic generating units of the first vibration generating module shown in FIGS. 3 and 4.

[0136] Referring to FIGS. 3 and 6, each of the first and second acoustic generating units 410 and 430 according to the present application can include a module frame 401, a bobbin 402, a magnet member 403, a coil 404, a center pole 405, and a damper 406. For example, in each of the first and second acoustic generating units 410 and 430, the module frame 401 can be represented by a fixing portion fixed to the rear cover 300, and the bobbin 402, the magnet member 403, the coil 404, the center pole 405, and the damper 406 can be represented as a vibrating portion for vibrating the display module 100, but is not necessarily limited thereto.

[0137] The module frame 401 can be supported by the rear cover portion 310. The module frame 401 can include a frame body 401a, an upper plate 401b, and a fixing bracket 401c.

[0138] The frame body 401a can be fixed to the rear cover portion 310. The frame body 401a can serve as a lower plate for supporting the magnet member 403.

[0139] The upper plate 401b can protrude from the front end of the frame body 401a so as to have a cylindrical shape with a hollow portion. The frame body 401a and the upper plate 401b can be formed of one body having a "U" shape. For example, the frame body 401a and the upper plate 401b are not limited to such terms and can be expressed in other terms such as "yoke".

[0140] The fixing bracket 401c can protrude from the side surface of the upper plate 401b. The fixing bracket 401c is fixed to the rear cover portion 310 by a second coupling member or a second connecting member, whereby the module frame 401 can be fixed to the rear cover portion 310.

[0141] The second coupling member or the second connecting member can be a screw or a bolt that passes through the fixing bracket 401c and is fastened or connected to the back cover portion 310 of the back cover 300. For example, a buffer ring may be interposed between the back cover portion 310 of the back cover 300 and the fixing bracket 401c, and the buffer ring can prevent the vibration of the back cover portion 310 from being transmitted to the module frame 401.

[0142] The bobbin 402 can be arranged on the module frame 401 to vibrate the back cover portion 310 of the back cover 300. The bobbin 402 can have a circular shape with a hollow portion 402a and can be coupled or connected to the back surface of the back cover portion 310. For example, the bobbin 402 can be embodied as an annular structure formed of a material processed from pulp or paper, aluminum, magnesium or an alloy thereof, a synthetic resin such as polypropylene, or a material made of a polyamide-based fiber, etc., but is not limited thereto. The bobbin 402 can vibrate the back cover 300 around the first hole 313 disposed on the back cover 300 by vibrating, for example, reciprocating up and down, by magnetic force.

[0143] The bobbin 402 according to an embodiment can have a circular or elliptical shape, but is not limited thereto. The bobbin 402 having an oval shape can include, but is not limited to, an elliptical shape, a rectangular shape with rounded corners, or a non-circular curved shape having a width different from its height. For example, in the case of the bobbin 402 having an oval shape, the ratio of the major axis diameter to the minor axis diameter can be configured to be 1.3:1 to 2:1. Such a bobbin 402 having an oval shape can improve the acoustics in the high frequency band compared to a circular shape, and may generate less heat due to vibration. Therefore, the bobbin 402 having an oval shape can have excellent heat dissipation characteristics.

[0144] The magnet member 403 can be disposed on the module frame 401 so as to be accommodated in the hollow portion 402a of the bobbin 402. The magnet member 403 can be a permanent magnet inserted into the hollow portion 402a of the bobbin 402. The magnet member 403 according to an embodiment can be embodied with a sintered magnet such as barium ferrite, and the material of the magnet member 403 can include, but is not limited to, one or more of iron (III) oxide (Fe2O3), barium carbonate (BaCO3), neodymium magnet, strontium ferrite with improved magnetic force components, alloy cast magnets of aluminum (Al), nickel (Ni), and cobalt (Co). As another example, the neodymium magnet can be neodymium-iron-boron (Nd-Fe-B). The embodiments of the present application are not limited thereto.

[0145] The coil 404 is wound so as to surround the lower outer peripheral surface of the bobbin 402, and an acoustic signal (or voice signal) from the outside is supplied thereto. The coil 404 can move up and down together with the bobbin 402. For example, the coil 404 can be represented by, but is not limited to, a "voice coil". When an acoustic signal (or current) is applied to the coil 404, the entire bobbin 402 can vibrate, for example, reciprocate up and down, based on Fleming's left hand rule based on the applied magnetic field formed around the coil 404 and the external magnetic field formed around the magnet member 403.

[0146] The center pole 405 is disposed on the magnet member 403 and can guide the vibration of the bobbin 402. For example, the center pole 405 can be inserted or accommodated in the hollow portion 402a of the bobbin 402 and thus can be surrounded by the bobbin 402. For example, the center pole 405 can be expressed by, but is not limited to, an elevation guide or pole pieces.

[0147] The damper 406 can be disposed between the module frame 401 and the bobbin 402. The damper 406 can be disposed between the frame body 401a of the module frame 401 and the upper outer peripheral surface of the bobbin 402. The damper 406 has a structure with wrinkles between one end and the other end, and thus can contract and relax due to the vibration of the bobbin 402. These dampers 406 can limit the vibration distance (or vertical movement distance) of the bobbin 402 via a restoring force. As an example, when the bobbin 402 vibrates more than a certain distance or less than a certain distance, the bobbin 402 can return to its original position by the restoring force of the damper 406. For example, the damper 406 can be expressed by other terms such as a spider, a suspension, or an edge, and is not limited thereto.

[0148] Each of the first and second acoustic generating units 410 and 430 according to an embodiment of the present application can be represented as an inner type in which the magnet member 403 is inserted into the hollow portion 402a of the bobbin 402.

[0149] Each of the first and second acoustic generating units 410 and 430 according to another embodiment of the present application can be represented as an outer type (or dynamic type) in which the magnet member 403 is arranged to surround the outside of the bobbin 402. For example, the outer type acoustic generating units 410 and 430 are the same as the inner type except that the magnet member 403 is provided between the frame body 401a and the upper plate 401b and the center pole 405 is provided on the lower plate 401a so as to be inserted into the hollow portion 402a of the bobbin 402. Therefore, the description thereof can be omitted.

[0150] Each of the first and second acoustic generating units 410 and 430 according to the present application can further include a bobbin protection member 407 disposed between the upper portion of the bobbin 402 and the back cover portion 310 of the back cover 300.

[0151] The bobbin protection member 407 can be formed in a cylindrical structure having an opening overlapping the hollow portion 402a of the bobbin 402 and can be coupled or connected to the upper surface of the bobbin 402. Since the bobbin protection member 407 can protect the bobbin 402 by covering the upper surface of the bobbin 402, deformation of the bobbin 402 due to an external impact can be prevented.

[0152] The bobbin protection member 407 can be configured in the form of an injection-molded product or a metal mold product. For example, the bobbin protection member 407 can be made of a fiber reinforcement, a composite resin containing a fiber reinforcement, or a metal. For example, it can also serve as a heat dissipation function that releases heat generated during the operation of the acoustic generating units 410 and 430. The fiber reinforcement can be any one of, or a combination of, a carbon fiber reinforcement (Carbon Fiber Reinforced Plastics, CFRP), a glass fiber reinforcement (Glass Fiber Reinforced Plastics, GFRP), and a graphite fiber reinforcement (Graphite Fiber Reinforced Plastics, GFRP), etc., and is not limited thereto.

[0153] The bobbin protection member 407 can be coupled or connected to the bobbin 402 via a double-sided tape or an adhesive resin. For example, the adhesive resin can be an epoxy resin or an acrylic resin, etc., and is not limited thereto.

[0154] The bobbin protection member 407 can be coupled or connected to the back cover portion 310 of the back cover 300 via a double-sided tape or an adhesive resin.

[0155] FIG. 7 is a graph showing the frequency-sound pressure characteristics of a first vibration generating module and a second vibration generating module according to an embodiment of the present application. In FIG. 7, the solid line shows the frequency-sound pressure characteristics of the first vibration generating module 400 having a voice coil method, and the dotted line shows the frequency-sound pressure characteristics of the second vibration generating module 500 having a piezoelectric method. In FIG. 7, the horizontal axis represents the frequency (Frequency, Hz), and the vertical axis represents the sound pressure (Sound Pressure Level, dB).

[0156] As can be seen from FIG. 7, the frequency-sound pressure characteristic (solid line) of the first vibration generation module 400 is relatively superior in the frequency range of 3 kHz or below or the sound pressure characteristic in the low frequency band compared to the frequency-sound pressure characteristic (dotted line) of the second vibration generation module 500. It can be seen that the frequency-sound pressure characteristic (dotted line) of the second vibration generation module 500 is relatively superior in the frequency range of 3 kHz or above or the sound pressure characteristic in the mid-high frequency band compared to the frequency-sound pressure characteristic (solid line) of the first vibration generation module 400. Therefore, the display device according to the embodiment of the present application can include the first vibration generation module 400 having relatively excellent bass output characteristics in order to improve the low frequency band sound generated by the vibration of the display module, and can include the second vibration generation module 500 having relatively excellent high frequency band output characteristics in order to improve the sound in the mid-high frequency band generated based on the vibration of the display module.

[0157] FIG. 8 is a graph showing the acoustic output characteristics of the display device according to an embodiment of the present application. In FIG. 8, the two-dot chain line is a graph showing the acoustic output characteristics of the display device according to the comparative example in which the system rear cover box shown in 5a and the system rear cover duct are not applied at all, the dotted line is a graph showing the acoustic output characteristics of the display device including the system rear cover in which only the system rear cover box shown in FIG. 5a is applied, and the solid line is a graph showing the acoustic output characteristics of the display device including the system rear cover box shown in FIG. 5a and the system rear cover in which the system rear cover duct is applied. In FIG. 8, the horizontal axis represents the frequency (Frequency, Hz), and the vertical axis represents the sound pressure (Sound Pressure Level, dB).

[0158] As can be seen from FIG. 8, the acoustic output characteristics (dotted line) of the display device including the system rear cover box are about 10 dB higher in sound pressure characteristics in the frequency range of about 3 kHz or less compared to the acoustic output characteristics (two-dot chain line) of the display device of the comparative example. Also, the acoustic output characteristics (solid line) of the display device including both the system rear cover box and the system rear cover duct are about 5 dB higher in sound pressure characteristics in the frequency range of about 3 kHz or less compared to the acoustic output characteristics (dotted line) of the display device including only the system rear cover box 611, and it can be seen that the sound pressure characteristics are also high at frequencies exceeding 3 kHz or in the mid-high frequency band.

[0159] FIG. 9 is a graph showing the acoustic output characteristics of the display device according to an embodiment of the present application. In FIG. 9, the dotted line is a graph showing the acoustic output characteristics of the display device including the rear cover to which the first rear cover hole shown in FIGS. 2 to 4 is not applied, and the solid line is a graph showing the acoustic output characteristics of the display device including the rear cover to which the first rear cover hole shown in FIGS. 2 to 4 is applied. In FIG. 9, the horizontal axis represents frequency (Frequency, Hz), and the vertical axis represents sound pressure (Sound Pressure Level, dB).

[0160] A predetermined bass region including a frequency of about 170 Hz is classified as so-called noise or abnormal noise (BSR (Buzz, Squeak, Rattle) noise), and thus improvement and quality assurance for this are required. Buzz noise is the sound produced by the diaphragm of the vibration generating module itself like a drum, and can be the noise generated when the natural vibration frequency of the vibrating body is the same as the vibration frequency flowing in from the outside. Squeak noise is the sound generated by the shear direction friction between the parts of the vibration generating module. When horizontal displacement occurs on the surface after two vibrating bodies come into contact, the fastening and separation of the two vibrating bodies are repeated, and it can be the generated noise. Rattle noise is the sound generated by the vertical collision between the parts of the vibration generating module, and can be the noise generated when the impact energy associated with the collision phenomenon between the vibrating bodies vibrating due to the vibration or force flowing in from the outside is released into the air.

[0161] Referring to FIGS. 2 to 4, a display device including vibration generating modules 400 and 500 may generate acoustic vibration noise such as noise or abnormal noise due to the structural characteristics of the display device. Such acoustic vibration noise can utilize the Helmholtz resonator formed by the back cover hole 311, the back cover portion 310, and the first vibration generating module 400 to reduce a specific resonance frequency band, and can reduce noise and abnormal noise (BSR Noise) including a frequency of about 170 Hz. For the detailed structure of the Helmholtz resonator, refer to FIG. 10, which will be described later.

[0162] As shown in FIG. 9, it can be known that the acoustic output characteristics (solid line) of the display device including the back cover 300 to which the back cover hole 311 is applied are reduced by about d1 in the sound pressure characteristics at the frequency corresponding to about 170 Hz compared with the acoustic output characteristics (dotted line) of the display device including the back cover 300 to which the back cover hole 311 is not applied. This is because by setting the resonance frequency of the Helmholtz resonator described above to about 170 Hz, the sound pressure at the frequency corresponding to noise or abnormal sound (BSR Noise) can be reduced by the resonance of the Helmholtz resonator.

[0163] Also, as shown in FIG. 9, it can be seen that the acoustic output characteristics (solid line) of the display device including the back cover 300 to which the back cover hole 311 is applied are about d2 higher in the sound pressure characteristics at the frequency corresponding to about 2.5 kHz compared with the acoustic output characteristics (dotted line) of the display device including the back cover 300 to which the back cover hole 311 is not applied. This is due to the improvement in the efficiency of the first vibration generation module 400 due to the air duct resistance generated by the back cover hole 311 and the characteristics of the Helmholtz resonator.

[0164] The Helmholtz resonator formed by the back cover hole 311, the back cover portion 310, and the first vibration generation module 400 can amplify or attenuate a specific frequency. Also, when the back cover hole 311 is applied to the back cover portion 310, a change occurs in the flow of the air layer vibrated by the first vibration generation module 400, so a change can occur in the frictional force of the air flow, which can be linked to the efficiency of the first vibration generation module 400. The frictional force of the air flow that can occur due to the introduction of the back cover hole 311 can be the air duct resistance, and the air duct can be an opening existing on the air flow path like the back cover hole 311. The resistance of the air duct will be described later with reference to FIG. 10.

[0165] Therefore, the Helmholtz resonator formed by the rear cover hole 311, the rear cover portion 310, and the first vibration generating module 400 can have the effect of attenuating noise or abnormal noise (BSR Noise) at a set frequency. And the Helmholtz resonator can prevent the efficiency of the first vibration generating module 400 from decreasing by optimizing the frictional force of the fluid generated by the first vibration generating module 400. Therefore, the present application can improve the sound pressure over a predetermined frequency or the entire low, middle, and high frequency bands by optimizing the position of the rear cover hole 311.

[0166] FIG. 10 is a diagram showing a Helmholtz resonator formed in a display device according to an embodiment of the present application.

[0167] The resonance frequency of the Helmholtz resonator can be expressed as in the following formula (1).

[0168] [Formula 1] TIFF0007708841000001.tif21170

[0169] In formula (1), "f" (or f) is the resonance frequency, "A" is the cross-sectional area of the opening or hole portion of the Helmholtz resonator, "ι" (or l) is the length of the opening or hole portion of the Helmholtz resonator, "V" is the volume of the Helmholtz resonator, and "c" is the speed of sound (at 15 degrees Celsius (°C), "c" is 340 m / sec, and it increases by 0.6 m for each 1 degree (°C) increase).

[0170] In Fig. 10, the volume (V) of the Helmholtz resonator can be calculated by setting the dimensions of the back cover portion 310 corresponding to the first vibration generating module 400 or the dimensions of the effective area of the back cover portion 310 vibrated by the first vibration generating module 400, and multiplying this by a predetermined height. For example, the area corresponding to the first vibration generating module 400 and the back cover portion 310 vibrated by the first vibration generating module 400 is set to 64 mm × 47 mm, the maximum displacement due to the vibration of the first vibration generating module 400 is 1.2 mm, the thickness of the back cover portion 310 is 0.8 mm, and the effective air gap between the back cover portion 310 and the structure (backlight unit) arranged above the back cover portion 310 is 0.5 mm. In this case, the height of the Helmholtz resonator can be set to 2.5 mm (1.2 mm + 0.8 mm + 0.5 mm) obtained by adding all these values.

[0171] Therefore, the volume (V) of the Helmholtz resonator can be calculated by multiplying the first vibration generating module 400 and the area vibrated by the first vibration generating module 400 by the height of the Helmholtz resonator. And when forming a back cover hole 311 that communicates with the effective air gap, is separated from the first vibration generating module 400, and has a predetermined size in the back cover portion 310, the distance between the first vibration generating module 400 and the back cover hole 311 can be the length (l) of the opening or hole portion of the Helmholtz resonator, and the cross-sectional area of the back cover hole 311 can be the area (A) of the opening or hole portion of the Helmholtz resonator.

[0172] As shown in Equation (1), the resonance frequency (f) of the Helmholtz resonator is proportional to the cross-sectional area (A) of the opening or hole portion of the back cover hole 311. For example, the narrower the cross-sectional area of the opening of the back cover hole 311, the lower the sound, the larger the volume (V) of the Helmholtz resonator, and the longer the length (l) of the opening or hole portion of the back cover hole 311, the lower the frequency.

[0173] Referring to Equation (1) and FIG. 9, when the display device according to the embodiment of the present application has a Helmholtz resonator formed by the rear cover hole 311, the rear cover portion 310, and the first vibration generation module 400, the distance between the rear cover hole 311 and the first vibration generation module 400, or the distance (l) and cross-sectional area (A) of the opening or hole portion of the rear cover hole 311 corresponding to the Helmholtz resonator, and the volume (V) of the Helmholtz resonator can be adjusted to reduce the acoustic vibration noise of the selected low-frequency range to the minimum possible extent.

[0174] In addition, the friction loss of flow due to the air duct resistance described above can be calculated as shown in Equation 2 below.

[0175] [Equation 2] TIFF0007708841000002.tif12170

[0176] In Equation (2), "Δp" is the frictional force of the air duct (opening), "d" is the diameter of the air duct (opening), and "q" indicates the air flow. As shown in Equation (2), it can be seen that the higher the air flow, the greater the frictional force, and the larger the diameter of the air duct (opening), the lower the frictional force.

[0177] When Equation 1 and Equation 2 are combined, the common factors of the two equations can be the area (A) of the opening or hole portion of the Helmholtz resonator corresponding to the rear cover hole 311 and the diameter (d) of the opening or hole portion of the air duct. In addition, Equation (1) can include the distance (ι) between the rear cover hole 311, which is an independent adjustment factor with respect to Equation (2), and the first vibration generation module 400. Therefore, the present application can reduce or minimize the friction loss caused by the air duct, for example, the opening or hole portion, and amplify or attenuate the sound pressure of the frequency set or adjusted using the Helmholtz resonator.

[0178] Therefore, the display device according to an embodiment of the present application can output, in front (FD) of the display panel 110, a first sound (S1) in a first sound range band generated by vibration of an intermediate portion (CP) of the display module 100 (or display panel) due to vibration of the first vibration generation module 400, and a second sound (S2) in a second sound range band generated by vibration of an end portion (EP) of the display module 100 (or display panel) due to vibration of the second vibration generation module 500. Therefore, the display device can provide more accurate sound to a listener, and can improve the immersion of the listener (or viewer) through the harmony (or coincidence) of video and sound.

[0179] In addition, the display device according to an embodiment of the present application outputs a first sound (S1) in a first sound range band by the first vibration generation module 400 of a voice coil method having relatively excellent bass output characteristics, and outputs a second sound (S2) in a second sound range band by the second vibration generation module 500 including a piezoelectric element having relatively excellent output characteristics in a high sound range band, thereby outputting sound having a wide sound range.

[0180] In addition, the display device according to an embodiment of the present application can implement stereo sound by the left sound by the first intermediate portion (C1) of the display module 100, the first sound generation unit 410 disposed at the first end portion (EP1), and the first piezoelectric vibration unit 510, and the right sound by the second intermediate portion (C2) of the display module 100, the second sound generation unit 430 disposed at the second end portion (EP2), and the second piezoelectric vibration unit 530.

[0181] And, in the display device according to an embodiment of the present application, sound waves are directly transmitted (or propagated) to the display module 100 by the vibrations of the first vibration generation module 400 and the second vibration generation module 500 respectively through the first and second holes 313 and 315 provided in the back cover portion 310 of the back cover 300 so as to overlap with the first vibration generation module 400 and the second vibration generation module 500 respectively, whereby the sound pressure characteristics and the sound quality of the sounds (S1, S3) can be further improved. Also, in the display device according to an embodiment of the present application, the noise characteristics of the bass are reduced by the Helmholtz resonator formed along the back cover hole 311 formed in the back cover 300, whereby the acoustic performance and the acoustic efficiency can be improved.

[0182] FIG. 11 is another cross-sectional view taken along the line I-I' shown in FIG. 1. FIG. 12 is an enlarged view of the portion B shown in FIG. 11. FIG. 13 is an enlarged view of the portion "C" shown in FIG. 11.

[0183] FIGS. 11 to 13 show the display device shown in FIG. 3 with the structures of the first and second vibration generation modules changed. Accordingly, in the following description, only the first and second vibration generation modules will be described in detail, and for the remaining configurations, the same reference numerals as those in FIG. 3 will be given, and duplicate descriptions will be omitted or briefly described.

[0184] Referring to FIGS. 1, 11, and 12, the first vibration generation module 400 according to another embodiment of the present application may include first and second acoustic generation units 410 and 430.

[0185] Each of the first and second acoustic generating units 410 and 430 can be supported by the back cover portion 310 of the back cover 300 so as to cover the first hole 313 formed in the back cover portion 310 of the back cover 300. Each of the first and second acoustic generating units 410 and 430 can vibrate based on an acoustic signal to vibrate the intermediate portion (CP) of the display module 100, thereby generating a first sound (S1) at the intermediate portion (CP) of the display module 100. For example, each of the first and second acoustic generating units 410 and 430 vibrates based on an acoustic signal to generate a sound wave, and this sound wave passes through the first hole 313 and is propagated (or transmitted) to the display module 100. The intermediate portion (CP) of the display module 100 vibrates due to the sound wave transmitted through the first hole 313, so that the first sound (S1) can be output to the front (FD) of the display module 100 at the intermediate portion (CP) of the display module 100.

[0186] According to the embodiment, the first hole 313 can serve as a sound wave propagation path (or an acoustic energy incident portion) through which sound waves (or acoustics) or acoustic energy generated by the vibration of the first and second acoustic generating units 410 and 430 are directly propagated (or incident) to the back surface of the display module 100.

[0187] According to this embodiment, each of the first and second acoustic generating units 410 and 430 can vibrate independently without vibrating the back cover portion 310, so that the intermediate portion (CP) of the display module 100 can be directly vibrated without using the back cover portion 310 as a diaphragm. The vibration of the back cover portion 310 can be reduced or minimized, a stable sound pressure can be generated, and the generation of noise associated with the vibration of the back cover portion 310 can be reduced or minimized.

[0188] Each of the first and second acoustic generating units 410 and 430 according to the embodiments of the present application may include a module frame 401, a bobbin 402, a magnet member 403, a coil 404, a center pole 405, and a damper 406. For example, in each of the first and second acoustic generating units 410 and 430, the module frame 401 can be expressed as a fixing portion fixed to the back cover 300, and the bobbin 402, the magnet member 403, the coil 404, the center pole 405, and the damper 406 can be expressed as a vibrating portion for vibrating the display module 100, but is not necessarily limited thereto.

[0189] The module frame 401 can be supported by the back cover portion 310. The module frame 401 according to one embodiment may include a frame body 401a, an upper plate 401b, and a fixing bracket 401c.

[0190] The frame body 401a can be fixed to the back cover portion 310. The frame body 401a can serve as a lower plate for supporting the magnet member 403.

[0191] The upper plate 401b can be disposed at the front end of the frame body 401a so as to have a cylindrical form with a hollow portion. The frame body 401a and the upper plate 401b can be formed of one body having a "U" shape. The frame body 401a and the upper plate 401b are not limited to the terms and can be expressed by other terms such as a yoke. The frame body 401a and the upper plate 401b can have a size corresponding to the first hole 313 in the back cover portion 310 of the back cover 300.

[0192] The fixing bracket 401c can protrude from the side surface of the upper plate 401b. The fixing bracket 401c can be fixed to the back cover portion 310 by the second connecting member 800. Thereby, the module frame 401 can be fixed to the back cover portion 310.

[0193] The bobbin 402 can be disposed on the module frame 401 such that a part of the uppermost side can be inserted or accommodated in the first hole 313 of the rear cover portion 310. Such a bobbin 402 vibrates, for example, reciprocates vertically by magnetic force within a region 313a that overlaps with the first hole 313 of the rear cover portion 310, and generates sound waves in the region 313a that overlaps with the first hole 313 of the rear cover portion 310. Except for this, it is substantially the same as the bobbin shown in FIG. 6, so duplicate explanations will be omitted.

[0194] The magnet member 403 can be disposed on the module frame 401 so as to be accommodated in the hollow portion 402a of the bobbin 402. The coil 404 is wound so as to surround the lower outer peripheral surface of the bobbin 402 and receives a supply of an external acoustic signal (or voice signal). The center pole 405 can be disposed on the magnet member 403 to guide the vibration of the bobbin 402. The damper 406 can be disposed between the module frame 401 and the bobbin 402. Each of the magnet member 403, the coil 404, the center pole 405, and the damper 406 is substantially the same as each of the magnet member, the coil, the center pole, and the damper shown in FIG. 6, except that they are arranged so as not to overlap with the rear cover portion 310 and only overlap with the first hole 313, so duplicate explanations will be omitted.

[0195] The second connecting member 800 can be interposed between the rear cover portion 310 around the first hole 313 and the fixing bracket 401c of the module frame 401 to couple (or connect) or fix the acoustic generating units 410 and 430 to the rear cover 300. The second connecting member 800 can include a double-sided tape or a double-sided foam tape having an adhesive layer. The adhesive layer of the second connecting member 800 according to an example can include an acrylic-based or urethane-based adhesive substance. For example, the adhesive layer of the second connecting member 800 is not an acrylic-based adhesive substance having relatively high hardness characteristics in order to reduce or minimize as much as possible the transmission of vibrations of the acoustic generating units 410 and 430 to the rear cover portion 310, but can include a urethane-based adhesive substance having relatively soft characteristics, and is not necessarily limited thereto.

[0196] According to an embodiment, the second connecting member 800 may have a second thickness (T2) that is thicker than the first thickness (T1) of the back cover 300, for example, the first thickness (T1) of the back cover portion 310. The second thickness (T2) of the second connecting member 800 according to an example may be 1 to 4 times the first thickness (T1) of the back cover portion 310. For example, when the second thickness (T2) of the second connecting member 800 is less than 1 time the first thickness (T1) of the back cover portion 310 (for example, the same thickness), since the distance (or gap or interval) between the rearmost surface of the display module 100 and the bobbin 402 is relatively short, the bobbin 402 vibrating along the thickness direction (Z) of the display module 100 may pass through (or penetrate) the first hole 313 and physically contact the rearmost surface of the display module 100, resulting in damage. Conversely, when the second thickness (T2) of the second connecting member 800 exceeds 4 times the first thickness (T1) of the back cover portion 310, since the distance (or gap or interval) between the rearmost surface of the display module 100 and the bobbin 402 is relatively long, due to the increase in the transmission loss of sound waves in the high-frequency band proportional to the distance, the acoustics in the mid-high frequency band may not be realized, or the sound pressure in the mid-high frequency band may decrease, and an acoustic separation phenomenon may occur between the acoustics in the mid-high frequency band generated by the first vibration generating module 400 and the acoustics in the sub-bass frequency band generated by the second vibration generating module 500. Therefore, in order for the bobbin 402 to vibrate stably within the first hole 313 without physically contacting the rearmost surface of the display module 100 and for the realization of the acoustics in the mid-high frequency band and the generation of the sound pressure in the mid-high frequency band, the second thickness (T2) of the second connecting member 800 can be set or adjusted to be 1 to 4 times the first thickness (T1) of the back cover portion 310.

[0197] Each of the first and second acoustic generating units 410 and 430 according to the embodiments of the present application may further include a bobbin protection member 408 disposed on the upper portion of the bobbin 402.

[0198] The bobbin protection member 408 can be formed in a cylindrical structure having a hollow portion 402a of the bobbin 402 and overlapping openings, and can be coupled or connected to the upper surface of the bobbin 402. The bobbin protection member 408 according to an example can protect the bobbin 402 by covering the upper surface of the bobbin 402, so that deformation of the bobbin 402 due to an external impact can be prevented.

[0199] The bobbin protection member 408 according to another embodiment can be formed in a plate-like structure that covers the hollow portion 402a and the entire upper surface of the bobbin 402, and can be coupled or connected to the upper surface of the bobbin 402. The bobbin protection member 408 according to another example can protect the bobbin 402 by covering the entire upper surface of the bobbin 402, so that deformation of the bobbin 402 due to an external impact can be prevented, and the sound pressure generated by the vibration of the bobbin 402 can be increased by arranging it on the bobbin 402 in a plate-like structure.

[0200] Each of the first and second acoustic generation units 410 and 430 according to the embodiments of the present application can vibrate independently without using the rear cover portion 310 as a diaphragm, pass through (or penetrate) the first hole 313, and generate sound waves (or acoustics) that directly vibrate the display module 100. It is possible to reduce or minimize the vibration of the rear cover portion 310 as much as possible, generate a stable sound pressure, and reduce or minimize the generation of noise associated with the vibration of the rear cover portion 310.

[0201] Referring to FIGS. 1, 11, and 13, the second vibration generation module 500 according to another embodiment of the present application can include first and second piezoelectric vibration units 510 and 530.

[0202] Each of the first and second piezoelectric vibration units 510 and 530 can be supported by the back cover portion 310 of the back cover 300 so as to cover the second hole 315 formed in the back cover portion 310 of the back cover 300. Each of the first and second piezoelectric vibration units 510 and 530 can vibrate based on an acoustic signal and generate a second sound (S2) from the end portion (EP) of the display module 100 by vibrating the end portion (EP) of the display module 100. For example, each of the first and second piezoelectric vibration units 510 and 530 vibrates due to an acoustic signal to generate a sound wave, and this sound wave passes through the second hole 315 and is propagated (or transmitted) to the display module 100, and the end portion (EP) of the display module 100 vibrates due to the sound wave transmitted through the second hole 315, so that the second sound (S2) can be output forward (FD) of the display module 100 at the end portion (EP) of the display module 100.

[0203] According to an embodiment of the present application, the second hole 315 can serve as a sound wave propagation path (or acoustic energy incident portion) through which sound waves (or acoustics) or acoustic energy generated by the vibrations of the first and second piezoelectric vibration units 510 and 530 directly propagate (or are incident) on the back surface of the display module 100.

[0204] According to an embodiment of the present application, each of the first and second piezoelectric vibration units 510 and 530 can vibrate independently (or alone) without vibrating the back cover portion 310, so that the end portion (EP) of the display module 100 can be directly vibrated without using the back cover portion 310 as a diaphragm, the vibration of the back cover portion 310 can be reduced or minimized as much as possible, a stable sound pressure can be generated, and the generation of noise associated with the vibration of the back cover portion 310 can be reduced or minimized as much as possible.

[0205] Each of the first and second piezoelectric vibration units 510 and 530 according to an embodiment of the present application can include a base plate 501 and a piezoelectric element 503.

[0206] The base plate 501 can be coupled or connected to the back cover portion 310 of the back cover 300 via the third adhesive member 805 to cover the second hole 315 in the back cover portion 310. For example, the base plate 501 can have a size larger than that of the second hole 315.

[0207] The base plate 501 can be used as a diaphragm that generates sound pressure inside the second hole 315. The base plate 501 according to an example can be made of any one of metal materials such as stainless steel, aluminum (Al), magnesium (Mg) alloy, magnesium, lithium (Li) alloy, and aluminum (Al) alloy, and is not necessarily limited thereto. For example, the base plate 501 can have a third thickness (T3) thinner than the first thickness (T1) of the back cover portion 310 in order to generate sounds in the mid-high frequency range. If the third thickness (T3) of the base plate is thicker than the first thickness (T1) of the back cover portion 310, the vibration of the piezoelectric element 503 may be difficult to propagate inside the second hole 315. The base plate 501 can vibrate due to the vibration of the piezoelectric element 503 to generate sounds (or sound pressure) in the mid-high frequency range of 3 kHz or more and propagate them inside the second hole 315.

[0208] The third adhesive member 805 is interposed between the back cover portion 310 around the second hole 315 and the base plate 501 to couple (or connect) or fix the piezoelectric vibration units 510 and 530 to the back cover 300. The third adhesive member 805 can include a double-sided tape or a double-sided foam tape having an adhesive layer. The adhesive layer of the third adhesive member 805 according to an example can include an acrylic-based or urethane-based adhesive substance. For example, the adhesive layer of the third adhesive member 805 can include a urethane-based adhesive substance having relatively soft properties instead of an acrylic-based adhesive substance having relatively high hardness in order to reduce or minimize the transmission of the vibrations of the piezoelectric vibration units 510 and 530 to the back cover portion 310, and is not necessarily limited thereto.

[0209] The piezoelectric element 503 can be arranged on the base plate 501 to vibrate the base plate 501. The piezoelectric element 503 can be arranged on the back surface of the base plate 501 so as to overlap with the second hole 315 of the back cover portion 310. For example, the piezoelectric element 503 can be coupled to the base plate 501 via the third coupling member 502.

[0210] The piezoelectric element 503 can include a piezoelectric material layer having a piezoelectric effect. Since these piezoelectric elements 503 have substantially the same configuration (or structure) as the first piezoelectric element 511 or the second piezoelectric element 531 shown in FIG. 4, duplicate descriptions will be omitted.

[0211] The piezoelectric element 503 can have a size smaller than that of the second hole 315 so as to be arranged within a region 315a that overlaps with the second hole 315 of the back cover portion 310. For example, the center portion of the piezoelectric element 503 can be located at the center portion of the second hole 315. The central portion of the piezoelectric element 503 can be located at the center portion of the second hole 315.

[0212] The third coupling member 502 can be a double-sided tape or a natural-curing adhesive, and is not limited thereto. For example, the third coupling member 502 can also be a thermosetting adhesive or a photocuring adhesive. In this case, however, the characteristics of the piezoelectric element 503 may be degraded by the heat of the curing process of the third coupling member 502.

[0213] Each of the first and second piezoelectric vibration units 510 and 530 according to the embodiments of the present application can further include a cover plate 505.

[0214] The cover plate 505 can be coupled to the back surface of the piezoelectric element 503 via the fourth coupling member 504. The cover plate 505 can serve to protect the piezoelectric element 503 by covering the back surface of the piezoelectric element 503. Further, the cover plate 505 can reinforce the mass of the piezoelectric vibration units 510 and 530, and increase the sound pressure characteristics in the low frequency band of the piezoelectric vibration units 510 and 530 by decreasing the resonance frequencies of the piezoelectric vibration units 510 and 530 as the mass increases. The cover plate 505 according to an example can have the same material and the same thickness as the base plate 501. However, it is not limited thereto, and it can have a different material or a different thickness from the base plate 501 depending on the acoustic characteristics required for the piezoelectric vibration units 510 and 530.

[0215] The fourth coupling member 504 can be a double-sided tape or a natural-curing adhesive, and is not limited thereto. For example, the fourth coupling member 504 can also be made of a thermosetting adhesive or a photocuring adhesive. For example, the characteristics of the piezoelectric element 503 may be degraded by the heat in the curing process of the fourth coupling member 504.

[0216] Therefore, the display device according to the embodiment of the present application can have the same effects as the display devices shown in FIGS. 2 to 4. Further, the display device according to the present embodiment is generated by the vibrations of the first vibration generation module 400 and the second vibration generation module 500 respectively, and the display module 100 vibrates by the sound waves passing through the second and third back cover holes 313 and 315 respectively to output sounds (S1, S2). Thus, without using the back cover 300 as a diaphragm, the sounds (S1, S2) can be output by the vibration of the display module 100. As a result, by reducing the vibration of the back cover portion 310 or suppressing it to the minimum possible extent, the generation of noise associated with the vibration of the back cover portion 310 can be prevented or reduced to the minimum possible extent.

[0217] FIG. 14 is a view showing the back of a display device according to another embodiment of the present application, FIG. 15 is a cross-sectional view taken along line II-II' shown in FIG. 14, and FIG. 16 is a cross-sectional view of the back cover shown in FIG. 15. This is a modification of the structure of the back cover in the display device shown in FIGS. 1 to 13. Accordingly, in the following description, only the back cover, the backlight unit, and the configurations related thereto will be described in detail, and the same reference numerals as those in FIGS. 1 to 13 will be assigned to the remaining configurations, and redundant descriptions will be omitted or briefly described.

[0218] Referring to FIGS. 14 to 16, in a display device according to another embodiment of the present application, the back cover 300 can support the backlight unit 130 of the display module 100 such that an air gap 132 is provided inside the backlight unit 130.

[0219] The back cover 300 according to one embodiment can include a back cover portion 310 that supports the back of the display module 100 and a side cover portion 330 that is connected and / or integrated to the edge of the back cover portion 310 to support the panel guide 200.

[0220] The back cover portion 310 is disposed to cover the back of the display module 100 and can support the display module 100. The back cover portion 310 can support the backlight unit 130 of the display module 100 and each of the first vibration generating module 400 and the second vibration generating module 500.

[0221] The back cover portion 310 can include a cross-sectional structure that is curved in a concave shape so that an internal air gap 132 can be provided inside the backlight unit 130. The internal air gap 132 (or air gap) inside the backlight unit 130 can improve the acoustic characteristics in the low frequency range by serving as a resonance cavity for the sound generated and propagated by the vibration of the first vibration generating module 400. The back cover portion 310 is substantially the same as the above-described back cover portion except that it includes a cross-sectional structure that is curved in a concave shape, so a duplicate description of the remaining structure excluding the cross-sectional structure that is curved in a concave shape is omitted.

[0222] According to one embodiment, the back cover portion 310 can have a cup structure in which a central portion (MP) that overlaps with an intermediate line (CL) of the display module 100 protrudes toward the back of the display device when based on the first direction (X) (or horizontal direction) of the display module 100. For example, the distance (or gap) between the upper surface of the back cover portion 310 and the back surface of the display panel 110 can increase gradually from the ends (EP1, EP2) toward the intermediate line (CL) when based on the first direction (X) (or horizontal direction) of the display module 100.

[0223] In the rear cover portion 310 according to an embodiment, when based on the first direction (X) (or the horizontal direction) of the display module 100, the distance (L2) (or depth) between the virtual plane (VPS) (or the horizontal line) connecting one end and the other end of the rear cover portion 310 and the central portion (MP) of the rear cover portion 310 can be 0.01% to 0.5% of the overall length (L1) of the rear cover portion 310. For example, when the depth (L2) of the middle portion (MP) of the rear cover portion 310 is 0% of the overall length (L1) of the rear cover portion 310, the rear cover portion 310 can have a substantially planar structure, and in this case, it becomes impossible to provide the air gap 132 inside the backlight unit 130. And when the depth (L2) of the central portion (MP) of the rear cover portion 310 exceeds 0.5% of the overall length (L1) of the rear cover portion 310, since the distance (or size) of the air gap 132 inside the backlight unit 130 increases, due to the increase in the transmission loss of the sound waves in the high-frequency band proportional to the distance, the sound in the mid-high frequency band may not be realized or the sound pressure in the mid-high frequency band may decrease, and an acoustic separation phenomenon may occur between the sound in the mid-high frequency band generated by the first vibration generation module 400 and the sound in the subwoofer frequency band generated by the second vibration generation module 500, and the thickness of the display device may increase. Therefore, the depth (L2) of the central portion (MP) of the rear cover portion 310 can be set to 0.01% to 0.5% of the overall length (L1) of the rear cover portion 310 so that the air gap 132 of the backlight unit 130 can serve as a resonance chamber for improving the acoustic characteristics in the low-frequency band.

[0224] The side cover portion 330 can bend from the edge of the rear cover portion 310 to support the panel guide 200. The side cover portion 330 can provide a backlight storage space on the rear cover portion 310 and can surround the side surface of the backlight unit 130 stored (or supported) in the backlight storage space (or space).

[0225] According to one embodiment, the rear cover 300 may further include a reinforcing portion 350. The reinforcing portion 350 can reinforce the rigidity of the rear cover 300, and thus can be a rigidity reinforcing portion, but is not limited thereto.

[0226] The reinforcing portion 350 can reinforce the rigidity of the rear cover 300 by protruding from the rear cover portion 310 at a certain height.

[0227] According to one embodiment, the reinforcing portion 350 may include an edge (or rim) reinforcing portion formed along the edge (or end) of the rear cover portion 310, and a plurality of intermediate reinforcing portions in the intermediate cover region of the rear cover portion 310 arranged side by side along the first direction (X). The plurality of intermediate reinforcing portions can be arranged side by side with the first and second vibration generating modules 400, 500 interposed therebetween.

[0228] The backlight unit 130 may include a reflective sheet 133, a light guide plate 131, a light source unit, and an optical sheet unit 135.

[0229] The reflective sheet 133 can be disposed on the rear cover portion 310 of the rear cover 300. The reflective sheet 133 can be disposed on the rear cover portion 310 so as to have a concave shape along the concave shape of the rear cover portion 310. For example, the reflective sheet 133 can be disposed on the rear cover portion 310 so as to have a conformal shape following the shape of the rear cover portion 310 since it warps into a concave shape due to its own weight. The reflective sheet 133 can reduce or minimize the loss of light by reflecting the light incident from the light guide plate 131 back toward the light guide plate 131.

[0230] The light guide plate 131 is disposed on the reflective sheet 133 so as to overlap the display panel 110, and can include a light incident surface provided on at least one side wall. The light guide plate 131 can include a light transmissive plastic or glass material. The light guide plate 131 causes the light incident from the light source unit through the light incident surface to travel (or emit light) toward the display panel 110.

[0231] The light guide plate 131 can be disposed on the reflective sheet 133 so as to have a concave form that does not follow the concave form of the back cover portion 310 as it is. For example, the light guide plate 131 can be disposed on the reflective sheet 133 so as to have a non-conformal form that does not follow the form of the reflective sheet 133 (or the back cover portion 310) as it is. Thereby, the backlight unit 130 can include an air gap 132 between the reflective sheet 133 and the light guide plate 131. The air gap 132 can be provided between the reflective sheet 133 and the light guide plate 131 that overlap with the middle portion (CP) of the display module 100. The ends of the reflective sheet 133 and the light guide plate 131 that overlap with the end portion (EP) of the display module 100 are in contact with each other, and thereby, the air gap 132 is not provided between the ends of the reflective sheet 133 and the light guide plate 131. The internal air gap 132 is provided between the reflective sheet 133 and the light guide plate 131 that overlap with the middle portion (CP) of the display module 100, and by serving as a resonance chamber for the sound generated and propagated by the vibration of the first vibration generation module 400, the acoustic characteristics in the low frequency band are improved.

[0232] The light guide plate 131 can be curved into a concave shape due to its own weight and disposed on the reflection sheet 133. For example, when the rigidity of the light guide plate 131 is relatively low, it can be curved along the concave shape of the reflection sheet 133 (or the back cover portion 310) as it is and disposed on the reflection sheet 133. Therefore, the air gap 132 is not provided between the reflection sheet 133 and the light guide plate 131. Conversely, when the rigidity of the light guide plate 131 is relatively high, it is disposed on the reflection sheet 133 in a flat state without being curved by its own weight. Thus, the internal air gap 132 can be formed between the remaining portions of the light guide plate 131 and the reflection sheet 133 excluding both ends. As an example, since the distance (or size) of the air gap 132 increases, the acoustic separation phenomenon may occur between the mid-high frequency band sound generated by the first vibration generating module 400 and the mid-low frequency band sound generated by the second vibration generating module 500, because the transmission loss of the high frequency band sound waves proportional to the distance increases, and the mid-high frequency band sound is not realized or the sound pressure in the mid-high frequency band decreases. Therefore, the light guide plate 131 may be made of a rigid material that can be curved into a concave shape with a non-isometric shape that does not follow the concave shape of the reflection sheet 133 (or the back cover portion 310) as it is, in order to provide the air gap 132 between the reflection sheet 133 and the light guide plate 131 that overlaps with the middle portion (CP) of the display module 100 and disposed on the reflection sheet 133.

[0233] The light source unit irradiates light onto the light incident surface of the light guide plate 131. The light source unit may be disposed on the back cover 300 so as to overlap with the first end of the display panel 110. The light source unit according to an example may include a plurality of light emitting diode elements mounted on a printed circuit board for the light source and irradiating light onto the light incident surface of the light guide plate 131.

[0234] The optical sheet unit 135 is disposed on the front surface of the light guide plate 131 to improve the luminance characteristics of the light emitted from the light guide plate 131. The optical sheet unit 135 may be disposed on the light guide plate 131 so as to have an isometric shape that follows the concave shape of the light guide plate 131 as it is.

[0235] Therefore, the display device according to the embodiment of the present application can have the same effects as the display device shown in FIGS. 11 to 13. In addition, the display device according to the embodiment of the present application is provided between the light guide plate 131 and the reflection sheet 133 of the backlight unit 130 by the back cover portion 310 of the back cover 300 having a cross-sectional structure curved in a concave shape, and the acoustic characteristics in the low frequency band can be further improved by the role of the resonance cavity of the air gap 132.

[0236] FIGS. 17a to 17g are diagrams showing various arrangement structures of the first and second vibration generation modules in a display device according to an embodiment of the present application, which are obtained by changing the arrangement structures of the first and second vibration generation modules in the display device shown in FIGS. 1 to 16. Accordingly, in the following description, since the remaining configurations and structures except for the arrangement structures of the first and second vibration generation modules are substantially the same as those described above, duplicate descriptions are omitted.

[0237] Referring to FIGS. 17a to 17c, in a display device according to an embodiment of the present application, the first vibration generation module 400 includes first and second acoustic generation units 410 and 430 respectively arranged in the first and second end regions (EA1, EA2) of the back cover portion 310 based on the first direction (X), which is substantially the same as the first vibration generation module 400 of the display device shown in FIGS. 1 to 16, so duplicate descriptions are omitted.

[0238] In the display device according to the embodiment of the present application, the second vibration generation module 500 can include at least three piezoelectric vibration units 510, 530, 550, 570, 590 respectively arranged in at least three portions of the first to fourth end regions (EA1, EA2, EA3, EA4) and the exact center region (or central region) of the back cover portion 310. Each of the first to fourth end regions (EA1, EA2, EA3, EA4) of the back cover portion 310 can correspond to or overlap with the first to fourth end portions of the display module respectively.

[0239] As an example, as shown in FIG. 17a, the second vibration generation module 500 may include first to third piezoelectric vibration units 510, 530, and 550 respectively disposed in the middle portions of the first to third end regions (EA1, EA2, EA3) of the back cover portion 310. The first to third piezoelectric vibration units 510, 530, and 550 may correspond to or overlap with the first to third end portions of the display module respectively. As an example, the back cover portion 310 may include three second holes 315 respectively in the first to third end regions (EA1, EA2, EA3) so as to overlap with the first to third piezoelectric vibration units 510, 530, and 550 respectively. Therefore, the display device shown in FIG. 17a has the same effects as the display devices shown in FIGS. 1 to 16, and by adding the third piezoelectric vibration unit 550, the stereoscopic effect of the sound can be increased by the sounds output respectively on the left side, right side, and upper side of the display module, and it can have 5-channel sound output characteristics. These display devices may be suitable for use as a monitor of a gaming computer, but are not limited thereto.

[0240] As another example, as shown in FIG. 17b, the second vibration generating module 500 may include first to fourth piezoelectric vibration units 510, 530, 550, and 570 respectively disposed in the middle of the first to fourth end regions (EA1, EA2, EA3, EA4) of the back cover portion 310. The first to fourth piezoelectric vibration units 510, 530, 550, and 570 may respectively correspond to or overlap with the first to fourth end portions of the display module. As an example, the back cover portion 310 may include four second holes 315 respectively formed in the first to fourth end regions (EA1, EA2, EA3, EA4) so as to overlap with the first to fourth piezoelectric vibration units 510, 530, 550, and 570 respectively. Therefore, the display device shown in FIG. 17b has the same effects as the display devices shown in FIGS. 1 to 16, and by adding the third and fourth piezoelectric vibration units 550 and 570, the stereoscopic effect of the sound can be further increased by the sound output from each of the left, right, upper, and lower sides of the display module, and it can have 6-channel sound output characteristics. Such a display device may be more suitable for use as a monitor of a gaming personal computer, but is not limited thereto.

[0241] As another example, as shown in Fig. 17c, the second vibration generation module 500 may include first to fourth piezoelectric vibration units 510, 530, 550, 570 respectively arranged in the middle parts of the first to fourth end regions (EA1, EA2, EA3, EA4) of the back cover part 310 and a fifth piezoelectric vibration unit 590 arranged in the central region (or the middle region) of the back cover part 310. The first to fourth piezoelectric vibration units 510, 530, 550, 570 can respectively correspond to or overlap with the first to fourth end portions of the display module, and the fifth piezoelectric vibration unit 590 can correspond to or overlap with the central part (or the middle part) of the display module. As an example, the back cover part 310 may include five second holes 315 respectively formed in the first to fourth end regions (EA1, EA2, EA3, EA4) so as to overlap with the first to fifth piezoelectric vibration units 510, 530, 550, 570, 590 respectively. Therefore, the display device shown in Fig. 17c has the same effects as the display devices shown in Figs. 1 to 16, and with the addition of the third to fifth piezoelectric vibration units 550, 570, 590, the stereoscopic effect of the sound can be further increased by the sounds output from the left side, right side, upper side, lower side, and the central side (or the middle side) of the display module respectively, and it can have 7-channel sound output characteristics. Such a display device may be more suitable for use as a monitor of a gaming personal computer, but is not limited thereto.

[0242] As another example, in the display device shown in Fig. 17c, the fifth piezoelectric vibration unit 590 arranged in the central region (or the middle region) of the back cover part 310 can be changed to an acoustic generating device. For example, due to the amplification effect of the low-frequency band sound generated by the acoustic generating unit arranged in the central region (or the middle region) of the back cover part 310, the low-frequency band sound characteristics can be improved.

[0243] Referring to FIGS. 17d and 17e, in a display device according to an embodiment of the present application, the first vibration generating module 400 may include first and second acoustic generating units 410 and 430 respectively disposed in first and second end regions (EA1, EA2) of the rear cover portion 310 based on the first direction (X). The first and second acoustic generating units 410 and 430 may respectively correspond to or overlap with first and second end portions of the display module. As an example, the rear cover portion 310 may include two first holes 313 respectively formed in the first and second end regions (EA1, EA2) so as to overlap with the first and second acoustic generating units 410 and 430 respectively. Such a first vibration generating module 400 is substantially the same as the first vibration generating module 400 of the display device shown in FIGS. 1 to 16, so redundant description is omitted.

[0244] In a display device according to an embodiment of the present application, the second vibration generating module 500 may include at least one piezoelectric vibration unit 510, 530, 550 disposed in at least one part of the central region (or middle region) of the rear cover portion 310 and the third and fourth end regions (EA3, EA4).

[0245] As an example, as shown in FIG. 17d, the second vibration generating module 500 may include one piezoelectric vibration unit 510 disposed in the exact center region (or central region) of the rear cover portion 310. One piezoelectric vibration unit 510 may correspond to or overlap with the exact center portion (or central portion) of the display module. As an example, the rear cover portion 310 may include one second hole 315 formed in the exact center region (or central region) so as to overlap with one piezoelectric vibration unit 510. Therefore, the display device shown in FIG. 17d has the same effects as the display devices shown in FIGS. 1 to 16, and by the first and second acoustic generating units 410, 430 and one piezoelectric vibration unit 510, stereo sound can be output by the acoustics output from the left side, the right side, and the exact center side (or central side) of the display module respectively, and it can have three-channel acoustic output characteristics. By reducing the number of relatively expensive piezoelectric vibration units 510 compared to the acoustic generating units 410, 430, the production unit price can be reduced.

[0246] As another example, as shown in FIG. 17e, the second vibration generating module 500 may include first to third piezoelectric vibration units 510, 530, and 550 respectively disposed in the central region (or the central area) of the rear cover portion 310 and the third and fourth end regions (EA3, EA4). The first to third piezoelectric vibration units 510, 530, and 550 may correspond to or overlap with the central portion (or the central part) of the display module and the third and fourth end portions respectively. As an example, the rear cover portion 310 may include three second holes 315 respectively formed in the central region (or the central area) and the third and fourth end regions (EA3, EA4) so as to overlap with the first to third piezoelectric vibration units 510, 530, and 550. Therefore, the display device shown in FIG. 17e has the same effects as the display devices shown in FIGS. 1 to 16, and the acoustic stereoscopic effect can be further increased by the acoustic output from the left side, right side, upper side, lower side, and the central side (or the central area) of the display module by the first and second acoustic generating units 410, 430 and the first to third piezoelectric vibration units 510, 530, and 550, and it can have 5-channel acoustic output characteristics. Such a display device may be suitable for use as a monitor for a gaming computer, but is not limited thereto.

[0247] As another example, in the display device shown in FIG. 17e, the first piezoelectric vibration unit 510 disposed in the central region (or the central area) of the rear cover portion 310 can be changed to an acoustic generating device. The first piezoelectric vibration unit 510 can correspond to or overlap with the central portion (or the central part) of the display module. As an example, the low-frequency band acoustic characteristics can be improved by the amplification effect of the low-frequency band acoustic generated by the acoustic generating unit disposed in the central region (or the central area) of the rear cover portion 310.

[0248] Referring to FIGS. 17f and 17g, in a display device according to an embodiment of the present application, the first vibration generating module 400 may include one acoustic generating unit 410 disposed in the exact center region (or central region) of the rear cover portion 310. One acoustic generating unit 410 may correspond to or overlap with the exact center portion (or central portion) of the display module. As an example, the rear cover portion 310 may include one first hole 313 formed in the exact center region (or central region) so as to overlap with one acoustic generating unit 410. Such a first vibration generating module 400 is substantially the same as the first vibration generating module 400 of the display device shown in FIGS. 1 to 16, so redundant description is omitted.

[0249] In a display device according to an embodiment of the present application, the second vibration generating module 500 may include at least two piezoelectric vibration units 510, 530, 550, 570 respectively disposed in at least two portions of the first to fourth end regions (EA1, EA2, EA3, EA4) of the rear cover portion 310.

[0250] As an example, as shown in FIG. 17f, the second vibration generation module 500 can include first and second piezoelectric vibration units 510 and 530 respectively disposed in the middle portions of the first and second end regions (EA1, EA2) of the rear cover portion 310. The first and second piezoelectric vibration units 510 and 530 can respectively correspond to or overlap with the first and second end portions of the display module. As an example, the rear cover portion 310 can include two second holes 315 respectively formed in the first and second end regions (EA1, EA2) so as to overlap with the first and second piezoelectric vibration units 510 and 530 respectively. Therefore, the display device shown in FIG. 17f has the same effects as the display devices shown in FIGS. 1 to 16, and with one acoustic generation unit 410 and the first and second piezoelectric vibration units 510 and 530, stereo sound can be output by the sound output from the left side, the right side, and the center side (or the middle side) of the display module respectively, and it can have three-channel sound output characteristics. Due to the amplification effect of the low-frequency band sound generated by the acoustic generation unit 410 disposed in the center region (or the middle region) of the rear cover portion 310, the low-frequency band sound characteristics can be improved.

[0251] As another example, as shown in FIG. 17g, the second vibration generating module 500 may include first to fourth piezoelectric vibration units 510, 530, 550, and 570 respectively disposed in the middle portions of the first to fourth end regions (EA1, EA2, EA3, EA4) of the back cover portion 310. The first to fourth piezoelectric vibration units 510, 530, 550, and 570 may respectively correspond to or overlap with the first to fourth end portions of the display module. As an example, the back cover portion 310 may include four second holes 315 respectively in the first to fourth end regions (EA1, EA2, EA3, EA4) so as to overlap with the first to fourth piezoelectric vibration units 510, 530, 550, and 570 respectively. Therefore, the display device shown in FIG. 17g has the same effects as the display devices shown in FIGS. 1 to 16, and the stereoscopic effect of the sound can be further increased by the one acoustic generating unit 410 and the first to fourth piezoelectric vibration units 510, 530, 550, and 570, and the acoustic output characteristics of 5 channels can be achieved. These display devices may be suitable for use as a monitor of a gaming personal computer, but are not limited thereto.

[0252] FIG. 18 is a graph showing frequency-sound pressure characteristics according to the placement location of the second vibration generating module in the first direction in a display device according to an embodiment of the present application. In FIG. 18, the thick solid line shows the frequency-sound pressure characteristics of the display device of the first experimental example including the second vibration generating module disposed in the central region (or the central area) of the back cover portion, the dotted line shows the frequency-sound pressure characteristics of the display device of the second experimental example including the second vibration generating module disposed in the end region of the back cover portion, and the dashed-dotted line shows the frequency-sound pressure characteristics of the display device of the third experimental example including the second vibration generating module disposed in the intermediate region between the central region (or the central area) and the end region of the back cover portion. In FIG. 18, the horizontal axis represents frequency (Frequency, Hz), and the vertical axis represents sound pressure (Sound Pressure Level, dB).

[0253] As can be seen from FIG. 18, it can be seen that the acoustic output characteristics (dotted line) of the display device of the first experimental example have relatively excellent sound pressure characteristics in the frequency range of 5 kHz or less and in the frequency range of 10 kHz or more. And it can be seen that the acoustic output characteristics (thick solid line) of the display device of the second experimental example and the acoustic output characteristics (dashed-dotted line) of the display device of the third experimental example have substantially similar sound pressure characteristics. Also, it can be seen that each of the acoustic output characteristics of the display devices of the first to third experimental examples has a sound pressure characteristic of 50 dB or more in the frequency range of 500 Hz or more.

[0254] Therefore, considering the sound pressure characteristics in the frequency range of 5 kHz or less of the display device according to the present application, the second vibration generation module may preferably be arranged in the central region (or the middle region) or the edge region of the back cover portion, as shown in FIGS. 2, 14, 17a to 17g.

[0255] FIG. 19 is a graph showing the frequency-sound pressure characteristics of the second vibration generation module according to the first and second embodiments in the display device according to the embodiment of the present application. In FIG. 19, the dotted line shows the frequency-sound pressure characteristics of the display device including the second vibration generation module according to the first embodiment shown in FIG. 4, and the thick solid line shows the frequency-sound pressure characteristics of the display device including the second vibration generation module according to the second embodiment having a base plate, as shown in FIG. 13. In FIG. 19, the horizontal axis represents the frequency (Frequency, Hz), and the vertical axis represents the sound pressure (Sound Pressure Level, dB).

[0256] As can be seen from FIG. 19, compared with the acoustic output characteristics (thick solid line) of the display device including the second vibration generation module according to the second embodiment, the acoustic output characteristics (dotted line) of the display device including the second vibration generation module according to the first embodiment have relatively high sound pressure characteristics in the frequency range of 500 Hz or less. And, compared with the acoustic output characteristics (dotted line) of the display device including the second vibration generation module according to the first embodiment, the acoustic output characteristics (thick solid line) of the display device including the second vibration generation module according to the second embodiment have relatively high sound pressure characteristics in the frequency range of 500 Hz or more.

[0257] Therefore, the second vibration generation module according to the first embodiment can be applied to a display device that requires relatively high sound pressure characteristics in the frequency range of 500 Hz or less. And, the second vibration generation module according to the second embodiment can be applied to a display device that requires relatively high sound pressure characteristics in the frequency range of 500 Hz or more.

[0258] The display device according to the present application is applicable to various applications that output sound by the vibration of a display module without a separate speaker. The display device according to the present application includes mobile devices, video phones, smart watches, watch phones, wearable apparatuses, foldable apparatuses, rollable apparatuses, bendable apparatuses, flexible devices, curved apparatuses, electronic notebooks, e-books, PMPs (portable multimedia players), PDAs (personal digital assistants), MP3 players, mobile phones, medical devices, desktop PCs, laptop PCs, netbook computers, workstations, navigation devices, car navigation devices, car display devices, TVs, wallpaper devices, signage devices, game devices, notebook computers, monitors, cameras, video cameras, and home appliances. When the display device of the present application is applied to a mobile device or the like, it can be a speaker or a receiver, but is not limited thereto.

[0259] The display device according to the present application can be described as follows.

[0260] The display device according to the present application can include a display module including a display panel for displaying an image, a panel guide for supporting an end portion on the back side of the display panel, a back cover for supporting the panel guide and covering the back surface of the display module, a first vibration generating module disposed in an intermediate portion of the back cover for vibrating an intermediate portion of the display panel, and a second vibration generating module disposed at an end of the back cover for vibrating an end portion of the display panel.

[0261] According to some examples of the present application, the back cover can further include a back cover portion for supporting the back surface of the display panel, and a side cover portion provided at an end of the back cover portion for supporting the panel guide.

[0262] According to some examples of the present application, the back cover portion can further include a first hole of the back cover portion provided in an intermediate portion of the back cover and disposed spaced apart from one side surface of the first vibration generating module.

[0263] According to some examples of the present application, it can further include a second hole of the back cover portion formed in a region corresponding to the first vibration generating module and the second vibration generating module of the back cover portion.

[0264] According to some examples of the present application, it can further include a system back cover for housing the display module, the panel guide, the back cover, the first vibration generating module, and the second vibration generating module. The system back cover can include a back structure covering the back surface of the display panel and the back cover portion, and a side structure provided at an end of the back structure for supporting the side surface of the display panel.

[0265] According to some examples of the present application, the back structure of the system back cover can be fastened to the back cover portion and can further include a system back cover box for sealing the first vibration generating module and the first hole of the back cover portion of the back cover.

[0266] According to some examples of the present application, the system rear cover box can improve the sound pressure generated by the first vibration generating module.

[0267] According to some examples of the present application, it can further include a sealing member for sealing the fastening portion of the system rear cover box and the rear cover portion.

[0268] According to some examples of the present application, the first hole in the rear cover portion, the rear cover portion and the first vibration generating module form a Helmholtz resonator, and the Helmholtz resonator can reduce the low-frequency noise characteristics.

[0269] According to some examples of the present application, the side structure of the system rear cover further includes a system rear cover duct formed on at least a part of the system rear cover, and the system rear cover duct can output the sound pressure generated by the first vibration generating module and the second vibration generating module to the outside.

[0270] According to some examples of the present application, the system rear cover duct can improve the sound pressure generated by the first vibration generating module and the second vibration generating module.

[0271] According to some examples of the present application, the panel guide includes a panel support portion connected to the end portion of the back surface of the display panel and supported by the side cover portion, and a guide side wall connected to the panel support portion and wrapping the side surface of the side cover portion. The vibration of the second vibration generating module can be transmitted to the end portion of the display panel through the second portion of the rear cover portion, the side cover portion and the panel support portion.

[0272] According to some examples of the present application, the display module further includes a backlight unit disposed between the back cover portion and the display panel. The backlight unit includes a reflective sheet disposed on the first and second back cover portions of the back cover, a light guide plate disposed on the reflective sheet, and a plurality of optical sheets disposed on the light guide plate. The vibration of the second vibration generation module can be transmitted to the end portion of the display panel through the second back cover portion, the side cover portion, and the panel support portion.

[0273] A display device according to an example of the present application can include a display module having a display panel for displaying an image, a panel guide for supporting an end portion at the back of the display panel, a back (rear) cover for supporting the panel guide and covering the back of the display module, a first vibration generation module disposed at an intermediate portion of the back cover for generating sound in a first sound range in an intermediate portion of the display panel, and a second vibration generation module disposed at an end portion of the back cover for generating sound in a second sound range different from the first sound range in the end portion of the display panel.

[0274] According to some examples of the present application, the first sound range may be lower than the second sound range.

[0275] According to some examples of the present application, it further includes a system back cover for housing the display module, the panel guide, the back cover, the first vibration generation module, and the second vibration generation module. The system back cover can include a back structure covering the back of the display device and a side structure provided at an end of the back structure.

[0276] According to some examples of the present application, the back structure of the system back cover is fastened to the back cover portion and further includes a system back cover box for sealing the first vibration generation module and the first hole of the back cover portion. The system back cover box can improve the sound pressure generated by the first vibration generation module.

[0277] According to some examples of the present application, it can further include a sealing member that seals the fastening portions of the system rear cover box and the rear cover portion.

[0278] A display device according to an example of the present application includes a display module including a display panel that displays an image, a rear cover disposed on the rear surface of the display module, a first vibration generating module disposed in a first rear region of the rear cover, and a second vibration generating module disposed in a second rear region of the rear cover, and the rear cover can include a first hole that overlaps with the first vibration generating module and a second hole that overlaps with the second vibration generating module.

[0279] According to some examples of the present application, the first rear region of the rear cover overlaps with an intermediate portion or an end portion (edge or end) of the display module, and the second rear region of the rear cover can overlap with a portion of the intermediate portion and the end portion of the display module excluding the first rear region.

[0280] According to some examples of the present application, the display device outputs a first sound in a first sound range band based on the vibration of the first vibration generating module, and outputs a second sound in a second sound range band based on the vibration of the second vibration generating module, and the first sound range band can be different from the second sound range band.

[0281] According to some examples of the present application, the rear cover is disposed on the rear surface of the display module, and further includes a rear cover portion that supports the first vibration generating module and the second vibration generating module, and the rear cover portion can include a first hole formed in the first rear region and a second hole formed in the second rear region.

[0282] According to some examples of the present application, the first vibration generating module can vibrate independently of the vibration of the rear cover portion, and the second vibration generating module can vibrate independently of the vibration of the rear cover portion.

[0283] According to some examples of the present application, the first back region of the back cover overlaps with the middle part of the display module, the second back region of the back cover overlaps with the end part of the display module, the back cover is disposed on the back of the display module, and includes a back cover portion that supports the first vibration generating module and the second vibration generating module, and may further include a hole portion formed in the back region between the first vibration generating module and the second vibration generating module of the back cover portion.

[0284] According to some examples of the present application, the back cover portion, the hole portion, and the first vibration generating module can form a Helmholtz resonator.

[0285] According to some examples of the present application, the display device according to an example of the present application further includes a system back cover disposed on the back of the back cover, the first back region of the back cover overlaps with the middle part of the display module, the second back region of the back cover overlaps with the end part of the display module, and the system back cover can include a system back cover box that seals the peripheral space of the first vibration generating module.

[0286] According to some examples of the present application, the system back cover can include a back structure disposed on the back of the back cover, a side structure connected to the end of the back structure and covering the side surface of the display module, and a system back cover duct formed in at least a part of the side structure.

[0287] According to some examples of the present application, the back cover is disposed on the back of the display module, further includes a back cover portion that supports the first vibration generating module and the second vibration generating module, further includes a hole portion formed in the back region between the first vibration generating module and the second vibration generating module of the back cover portion, and the system back cover box can accommodate the first vibration generating module and the hole portion.

[0288] According to some examples of the present application, a display device according to an example of the present application further includes a panel guide supported by a rear cover to support an end portion of the rear surface of the display panel, and the display module further includes a backlight unit supported by the rear cover and disposed on the rear surface of the display panel. The backlight unit can include a reflective sheet disposed on the rear cover and covering the first hole and the second hole, a light guide plate disposed on the reflective sheet, and an optical sheet portion disposed on the light guide plate.

[0289] According to some examples of the present application, the rear cover is disposed on the rear surface of the display module and further includes a rear cover portion that supports the first vibration generating module and the second vibration generating module. The rear cover portion can include a cross-sectional structure having a concave curved shape.

[0290] According to some examples of the present application, a display device according to an example of the present application further includes a panel guide supported by a rear cover to support an end portion of the rear surface of the display panel, and the display module further includes a backlight unit disposed between the display panel and the rear cover portion. The backlight unit can include a reflective sheet disposed on the rear cover portion and covering the first hole and the second hole, a light guide plate disposed on the reflective sheet, an optical sheet portion disposed on the light guide plate, and an air gap provided between the reflective sheet and the light guide plate.

[0291] According to some examples of the present application, the reflective sheet is disposed on the rear cover portion so as to have an isometric shape along the shape of the rear cover portion, and the light guide plate can be disposed on the reflective sheet so as to have a non-isometric shape that does not follow the shape of the rear cover portion.

[0292] A display device according to an example of the present application includes a display module including a display panel for displaying an image, a back cover further including a back cover portion covering the back surface of the display module, and a first vibration generation module and a second vibration generation module disposed on both the back cover portions for vibrating the display module, and may include a first gap disposed between the first vibration generation module of the back cover portion and the display module, and a second gap disposed between the second vibration generation module and the display module.

[0293] According to some examples of the present application, the back cover portion may include a first hole providing a first gap between the first vibration generation module and the display module, and a second hole providing a second gap between the second vibration generation module and the display module.

[0294] According to some examples of the present application, the display module may further include a backlight unit disposed between the display panel and the back cover portion, the back cover portion includes a structure curved in a concave shape in a cross-sectional view, and the backlight unit may include a reflective sheet disposed on the back cover portion and covering the first gap and the second gap, a light guide plate disposed on the reflective sheet, an optical sheet portion disposed on the light guide plate, and an air gap provided between the reflective sheet and the light guide plate.

[0295] According to some examples of the present application, the first vibration generation module includes an acoustic generation unit including a bobbin and a coil wound around the bobbin, and the bobbin of the acoustic generation unit may be connected to the back cover around the first hole.

[0296] According to some examples of the present application, the first vibration generation module includes an acoustic generation unit including a bobbin and a coil wound around the bobbin, and the bobbin of the acoustic generation unit may have a size that can be accommodated in the first hole.

[0297] According to some examples of the present application, the first vibration generating module is connected to the back cover via a connecting member, and the thickness of the connecting member can be 1 to 4 times the thickness of the back cover.

[0298] According to some examples of the present application, the second vibration generating module can include a piezoelectric vibration unit having a piezoelectric element.

[0299] According to some examples of the present application, the second vibration generating module includes a piezoelectric vibration unit having a piezoelectric element, the piezoelectric vibration unit includes a base plate connected to the back cover so as to cover the second hole, and the piezoelectric element can be arranged on the base plate.

[0300] According to some examples of the present application, the piezoelectric vibration unit further includes a cover plate connected to the piezoelectric element, and the piezoelectric element and the cover plate can have a size smaller than the size of the second hole.

[0301] According to some examples of the present application, the first vibration generating module overlaps with either the middle part or the end part of the display module, and the second vibration generating module can overlap with the remaining one of the middle part and the end part of the display module.

[0302] According to some examples of the present application, the display module includes first and second end parts arranged side by side with each other and third and fourth end parts arranged side by side with each other, the second vibration generating module includes a first piezoelectric vibration unit overlapping with the first end part of the display module and a second piezoelectric vibration unit overlapping with the second end part of the display module, and the first vibration generating module can include first and second acoustic generating units arranged adjacent to the first and second piezoelectric vibration units respectively.

[0303] According to some examples of the present application, the second vibration generating module can further include at least one of a third piezoelectric vibration unit that overlaps with the third end portion of the display module, a fourth piezoelectric vibration unit that overlaps with the fourth end portion of the display module, and a fifth piezoelectric vibration unit that overlaps with the central portion of the display module.

[0304] According to some examples of the present application, the display module includes first and second end portions arranged side by side with each other, and third and fourth end portions arranged side by side with each other. The first vibration generating module includes a first acoustic generating unit that overlaps with the first end portion of the display module and a second acoustic generating unit that overlaps with the second end portion of the display module. The second vibration generating module can include at least one of a first piezoelectric vibration unit that overlaps with the central portion of the display module, a second piezoelectric vibration unit that overlaps with the third end portion of the display module, and a third piezoelectric vibration unit that overlaps with the fourth end portion of the display module.

[0305] According to some examples of the present application, the display module includes first and second end portions arranged side by side with each other, and third and fourth end portions arranged side by side with each other. The first vibration generating module includes an acoustic generating unit that overlaps with the central portion of the display module. The second vibration generating module can include a first piezoelectric vibration unit that overlaps with the first end portion of the display module and a second piezoelectric vibration unit that overlaps with the second end portion of the display module.

[0306] According to some examples of the present application, the second vibration generating module can further include at least one of a third piezoelectric vibration unit that overlaps with the third end portion of the display module and a fourth piezoelectric vibration unit that overlaps with the fourth end portion of the display module.

[0307] The features, structures, effects, etc. described in the examples of the present application mentioned above are included in at least one example of the present application and are not necessarily limited to only one example. Furthermore, the features, structures, effects, etc. exemplified in at least one example of the present application can be combined or modified and implemented for different examples by those with ordinary knowledge in the field to which the present application belongs. Therefore, the content related to these combinations and modifications should be construed as being included within the scope of the present application.

[0308] The present application described above is not limited to the foregoing embodiments and the attached drawings, and it will be apparent to those with ordinary knowledge in the technical field to which the present application belongs that a plurality of substitutions, modifications, and changes are possible within the scope not departing from the technical matters of the present application. Therefore, the scope of the present application is indicated by the scope of the claims described hereinafter, and all changes or modified forms derived from the meaning and scope of the claims and their equivalent concepts should be construed as being included within the scope of the present application.

Description of Reference Numerals

[0309] 100: Display module 110: Display panel 130: Backlight unit 200: Panel guide 300: Rear cover 310: Rear cover portion 311: Rear cover hole 313: First hole 315: Second hole 400: First vibration generating module 410, 430: Acoustic generating unit 500: Second vibration generating module 501: Base plate 503: Piezoelectric element 505: Cover plate 510, 530: Piezoelectric vibration unit 600: System rear cover 611: System rear cover box 631: System rear cover duct 800: Second connecting member

Claims

1. A display device including a display panel configured to display an image, a rear cover including a rear cover portion at the rear of the display module, a reflective sheet between the display module and the rear cover portion, a light guide plate on the reflective sheet, an optical sheet on the light guide plate, an air gap between the reflective sheet and the light guide plate, a first vibration generating device in a first rear region of the rear cover portion, a second vibration generating device in a second rear region of the rear cover portion, and further including a space between the display panel and the optical sheet.

2. The rear cover portion includes a first hole overlapping with the first vibration generating device, and a second hole overlapping with the second vibration generating device, The display device according to claim 1, wherein the reflective sheet is configured to cover the first hole and the second hole.

3. A display device, including a display panel configured to display an image, a rear cover including a rear cover portion at the rear of the display module, a backlight unit between the display panel and the rear cover portion, including an acoustic box, a first vibration generating device in a first rear region of the rear cover portion, a second vibration generating device in a second rear region of the rear cover portion, and wherein the backlight unit includes a light guide plate on a reflective sheet, and an optical sheet on the light guide plate, The display device further includes a space between the display panel and the optical sheet.

4. The display device according to claim 3, wherein the backlight unit includes the reflective sheet in the rear cover portion.

5. The display device according to claim 4, wherein the acoustic box is between the reflective sheet and the light guide plate.

6. The rear cover portion includes a first hole overlapping with the first vibration generating device, and a second hole overlapping with the second vibration generating device, The display device according to claim 4, wherein the reflective sheet is configured to cover the first hole and the second hole.

7. The first rear region of the rear cover portion overlaps with an intermediate portion or an edge portion of the display module. The second back region of the back cover portion overlaps with a portion excluding the first back region among the middle portion and the edge portion of the display module, and the display device according to any one of claims 1 to 6.

8. The first vibration generating device is configured to output a first sound in a first sound range band. The second vibration generating device is configured to output a second sound in a second sound range band. The first sound range band is different from the second sound range band, and the display device according to any one of claims 1 to 6.

9. The first vibration generating device is configured to vibrate without vibrating the back cover portion. The second vibration generating device is configured to vibrate without vibrating the back cover portion, and the display device according to claim 1.

10. The first back region of the back cover portion overlaps with the middle portion of the display module. The second back region of the back cover portion overlaps with the edge portion of the display module. The back cover portion includes a hole portion between the first vibration generating device and the second vibration generating device, and the display device according to any one of claims 1 to 6.

11. The back cover portion, the hole portion, and the first vibration generating device constitute a Helmholtz resonator, and the display device according to claim 10.

12. Further includes a system back cover on the back of the back cover portion. The first back region of the back cover portion overlaps with the middle portion of the display module. The second back region of the back cover portion overlaps with the edge portion of the display module. The system back cover includes a system back cover box configured to seal the peripheral space of the first vibration generating device, and the display device according to any one of claims 1 to 6.

13. The system back cover includes a back structure on the back of the back cover portion, a side structure connected to the edge portion of the back structure and configured to cover the side surface of the display module, and further includes a system back cover duct in at least a part of the side structure, and the display device according to claim 12.

14. The back cover portion includes a hole portion in the back region between the first vibration generating device and the second vibration generating device. The system rear cover box is the display device according to claim 12, configured to accommodate the first vibration generating device and the hole portion.

15. The display device according to any one of claims 1 to 6, wherein the rear cover portion includes a concave curved surface structure having a shape that is curved in a concave shape in a cross-sectional view.

16. The reflective sheet is on the rear cover portion so as to have an isosceles shape along the concave curved surface structure of the rear cover portion. The display device according to claim 15, wherein the light guide plate is on the reflective sheet so as to have a non-isosceles shape that does not follow the concave curved surface structure of the rear cover portion.

17. The first vibration generating device includes an acoustic generating portion including a bobbin and a coil wound around the bobbin. The display device according to claim 2 or 6, wherein the bobbin is connected to the rear cover around the first hole.

18. The first vibration generating device includes an acoustic generating portion including a bobbin and a coil wound around the bobbin. The display device according to claim 2 or 6, wherein the bobbin is housed in the first hole.

19. The first vibration generating device is connected to the rear cover portion via a connecting member. The display device according to claim 18, wherein the connecting member has a thickness that is 1 to 4 times the thickness of the rear cover portion.

20. The display device according to any one of claims 1 to 6, wherein the second vibration generating device includes a piezoelectric element.

21. The second vibration generating device includes a piezoelectric vibration portion having a piezoelectric element. The piezoelectric vibration portion further includes a base plate connected to the rear cover portion so as to cover the second hole. The display device according to claim 2 or 6, wherein the piezoelectric element is on the back surface of the base plate.

22. The piezoelectric vibration portion further includes a cover plate connected to the piezoelectric element. The display device according to claim 21, wherein each of the piezoelectric element and the cover plate has a size smaller than the size of the second hole.

23. The display device according to any one of claims 1 to 6, wherein the display panel is configured to function as a diaphragm for outputting sound.

24. The display module further includes a first edge portion and a second edge portion parallel to each other, and a third edge portion and a fourth edge portion parallel to each other. The first vibration generating device is a first acoustic generating part that overlaps with the first edge part of the display module, and includes a second acoustic generating part that overlaps with the second edge part of the display module. The second vibration generating device further includes at least one of a first piezoelectric vibration part that overlaps with an intermediate part of the display module, a second piezoelectric vibration part that overlaps with the third edge part of the display module, and a third piezoelectric vibration part that overlaps with the fourth edge part of the display module. The display device according to any one of claims 1 to 6.

25. The display module further includes a first edge part and a second edge part that are parallel to each other, and a third edge part and a fourth edge part that are parallel to each other. The first vibration generating device includes an acoustic generating part that overlaps with a central part of the display module. The second vibration generating device includes a first piezoelectric vibration part that overlaps with the first edge part of the display module, and a second piezoelectric vibration part that overlaps with the second edge part of the display module. The display device according to any one of claims 1 to 6.

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