Display device

Disclosed is a display device that includes a display panel and a multi-layered panel provided adjacent the display panel. The multi-layered panel may include a front plate located toward the display panel, a rear plate provided parallel to the front plate, and a honeycomb mesh interposed between the front plate and the rear plate. The honeycomb mesh may have a plurality of hexagonal cells. A metal plate may be coupled to a rear surface of the multi-layered panel and a drive board may be seated on the metal plate. At least one of the front plate or the rear plate may include at least one opening that extends parallel to a shorter side of the display device.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application claims priority under 35 U.S.C. §119 to Korean Application No. 10-2013-0080262 filed in Korea on Jul. 9, 2013, whose entire disclosure is hereby incorporated by reference.

BACKGROUND

The present disclosure relates to a display device that includes a multi-layered panel having a honeycomb pattern mesh.

A conventional display device using a liquid crystal display panel or a plasma display panel includes a glass panel providing a basic screen, an intermediate frame, and a rear cover. Among these components, the intermediate frame serves to support a variety of display device drive circuits arranged thereon, and to connect the glass panel and the rear cover to each other. On the other hand, the rear cover serves to increase rigidity of the entire display device, to efficiently radiate heat generated from the circuits, and to define an external appearance of the display device.

In recent years, in a bid to reduce the thickness of the display device, drastic attempts to improve and simplify a conventional configuration of the display device have been implemented. In particular, as the thickness of the display device is reduced, enhancement in mechanical rigidity of the rear cover, development of heat radiation materials, and configuration improvement have been continuously studied.

Although a representative material for a typical rear cover of conventional display devices is a metal material, such as aluminum, this material may limit mechanical properties of the rear cover as the thickness of the rear cover is extremely reduced.

In particular, as a level of contribution of the rear cover to the rigidity of the entire display device increases, it is necessary that the rear cover is formed of a material having requisite mechanical properties. The conventional aluminum rear cover has difficulty in achieving required mechanical properties. Moreover, this problem may worsen as the size of the rear cover increases. For this reason, there is demand for developments of novel materials for the rear cover except for aluminum as well as novel configurations thereof.

DETAILED DESCRIPTION

Hereinafter, a display device100having a multi-layer panel130according to the present disclosure will be described in detail with reference to the accompanying drawings. With respect to constituent elements used in the following description, suffixes “module” and “unit” are given or mingled with each other only in consideration of ease in the preparation of the specification, and do not have or serve as different meanings.

FIG. 1is an exploded perspective view showing the display device100according to one embodiment of the present disclosure. The display device100of the present disclosure includes a display panel110, a middle frame120, a multi-layer panel130, a metal plate140, and a rear cover150.

The display panel110may serve to output an image on a screen. More specifically, the display panel110divides an image into a plurality of pixels to digitalize information, such as color, brightness, chroma, etc., on a per pixel basis into electric signals, thereby controlling emission of light from the pixels to output an image having desired color, brightness and chroma based on the electric signals.

Flat panel display devices having the above-described image output function may be utilized in various ways in liquid crystal display, thin film transistor liquid crystal display, organic light emitting diode (OLED) display fields. In particular, as the OLED display device100has recently been used, a configuration is simplified and omission of a support structure is necessary to achieve a reduced thickness and greater heat radiation.

The middle frame120may serve to provide a finished look around the periphery of the display device100and to align the display panel110and the multi-layer panel130with each other. Although a top case configured to cover a front surface and a rear case configured to cover a rear surface may be provided individually, in order to reduce the thickness of the display device100, and to provide a simplified configuration as well as a reduction in the size of a bezel, the middle frame120may be used instead of the top case that covers the front surface.

The multi-layer panel130may be attached to a rear surface of the display panel110to support the display panel110. Reduction in the thickness of the display device100causes reduction in the thickness of a rear panel that supports the rear surface of the display panel110. An excessively reduced thickness of the rear panel may reduce rigidity and increase possibility of deformation, whereas an excessively increased thickness of the rear panel may increase the weight and manufacturing costs.

To solve the above-described problem, the multi-layer panel130may be used as the rear panel. The multi-layer panel130may provide sufficient rigidity while minimizing increase in weight. As exemplarily shown inFIG. 1, the multi-layer panel130may have a triple layered configuration consisting of a pair of thin plates131and132and a honeycomb mesh135interposed between the thin plates131and132.

The honeycomb mesh135is configured such that a plurality of unit cells in the form of empty hexagonal shapes may be arranged in a plurality of columns to produce a honeycomb structure or pattern. Sidewalls of the unit cells and the thin plates131and132are oriented to face in different directions. For example, the sidewalls of the unit cells may be perpendicular to the thin plates131and132. As such, the unit cells may serve to provide added rigidity and prevent bending of the display device110. As compared to a conventional monolayer rear panel, the multi-layer panel130may have a smaller weight and achieve greater rigidity despite use of a reduced amount of material. Due to the honeycomb pattern mesh and thin metal plate layers, the multi-layered plate130may also be referred to herein as a sandwich honeycomb panel.

The multi-layer panel130and the display panel110may be attached to each other with an adhesive layer115interposed therebetween. The adhesive layer115may be formed by applying an adhesive, or may be formed of a double-sided adhesive tape. The adhesive layer115may be laminated on the entire rear surface of the display panel110, or the adhesive layer115may be laminated only on a part of the rear surface.

The metal plate140may be attached to a rear surface of the multi-layer panel130, and drive boards147,148and149(seeFIG. 11) may be seated on the metal plate140. The metal plate140may be configured to cover the entire rear surface or a partial region of the multi-layer panel130. The metal plate140may have a size required to support the drive boards147,148and149arranged thereon, and thus may cover only a part of the rear surface of the multi-layer panel130.

The metal plate140may be formed of a metal material, such as aluminum, to achieve rigidity of the display device100and to radiate heat generated from the drive boards147,148and149. To reduce bending deformation, reinforcement ribs may be formed at a center region of the metal plate140.

The drive boards147,148and149seated on the metal plate140may include three types. The power supply board147may be a hardware that converts Alternating Current (AC) received from an external source into Direct Current (DC) that will be stably used by the display device100, so as to supply power suitable for each system. If the power supply board147fails to stably supply power to the system, the system may be down or may malfunction. The power supply board147may be divided into an electromagnetic interference filter part, an AC-DC rectifier part, a DC-AC switching converter part, and an output part, and may emit a great quantity of heat during driving.

The main board148may serve to control the display panel110to generate a screen image and to control general functions of respective components. As functions of the display device100have recently been diversified, the number of elements mounted on the main board148has increased, and functions of the respective elements become important.

The timing controller149may be provided to a large screen of 10 inches or more, and may include semiconductors that adjust the quantity of data to be transmitted to the drive unit of the display panel110and improve resolution of an image. The timing controller149receives image information and transmits the same to the drive unit of the display panel110such that the entire display panel110outputs an image with no time difference.

Although conventional display devices having a small display panel do not need the timing controller149, increase in the size of a screen causes time difference when a color image is formed throughout the screen and this appears as an afterimage on the screen. To prevent this, the timing controller149adjusts transmission time of signals.

In particular, the power supply board147and the main board148generate a great quantity of heat, and thus a region affected by both the power supply board147and the main board148has a relatively high temperature. That is, a place where the power supply board147and the main board148are located generates a great quantity of heat, and radiation of heat is important to the corresponding regions.

If heat generated from the drive boards147,148and149or heat generated from the display panel110are not radiated and the temperature of the display device100increases, the aforementioned respective members undergo thermal expansion. Although there may be no problems if the respective members expand and contract at the same rate, the respective members exhibit expansion and contraction at different rates of thermal expansion.

The metal plate140or the multi-layer panel130, which are formed of a metal material, have a high rate of thermal expansion, whereas the display panel110has a low rate of thermal expansion. Such difference between the rates of thermal expansion of the respective members causes the member having a lower rate of thermal expansion to be concavely bent as temperature increases.

Since the multi-layer panel130has a higher rate of thermal expansion than that of the display panel110, if heat is generated during driving of the display device100, both ends of the display panel110are bent forward, causing a front surface of the display panel110to be concavely deformed. In current situation in which sizes of flat display devices100is increasing, such bending deformation may be easily noticeable. Therefore, it is necessary to prevent this bending deformation.

Accordingly, the present disclosure has a feature in that, to compensate for thermal deformation due to difference between rates of thermal expansion of the respective members during thermal expansion, a rigid bar may be provided to compensate for structural deformation of the multi-layer panel130and the metal plate140. Hereinafter, structural features of the respective members will be described.

FIG. 2is a rear view showing the thin front plate131of the display device100according to one embodiment of the present disclosure. The thin front plate131has an opening perforated in a direction parallel to a short side of the display device100(e.g., vertical direction). Since effects of thermal expansion appears more in a longer side direction, bending deformation occurs in the longer side direction to a greater degree. Accordingly, to compensate for deformation in the longer side direction, the opening is formed in a direction perpendicular to a longer side.

In general, since the display device100has a short vertical length and a long horizontal length, in the following description, the horizontal direction refers to a direction parallel to a long side and the vertical direction refers to a direction parallel to a short side. It should be appreciated, however, that the present disclosure is applicable for display panels having various shapes, including those which are longer height than width.

The opening, as exemplarily shown inFIG. 2, may include a plurality of holes131aaligned in a vertical direction to define a plurality of vertical lines131bhorizontally spaced apart from one another. Each line131bmay extend from the top to the bottom as exemplarily shown inFIG. 2, or may extend from the top to a middle point or from the bottom to the middle point such that upper half lines and lower half lines are alternately arranged rather than being connected to each other as exemplarily shown inFIG. 3. Alternatively, as exemplarily shown inFIG. 4, instead of the holes131a, the opening may include elongated slots.

If the thin front plate131thermally expands in response to temperature increase, the size of the opening may be reduced to cancel a variation in length due to thermal expansion. As such, it is possible to reduce length variation of the multi-layer panel130that exhibits greater length variation than the display panel110. Similar to the thin front plate131, the thin rear plate132may include an opening consisting of vertically aligned holes132ato define a plurality of lines132bhorizontally spaced apart from one another.

Although the respective lines131bmay be arranged equidistant from each other in the same manner as the above-described thin front plate131, as exemplarily shown inFIG. 5, the lines may be more densely arranged in a center region that is most susceptible to the bending deformation. Alternatively, the interval between the lines132bof the thin rear plate132may be more reduced at a portion where elements that emit a large amount of heat are located.

The thin front plate131may be covered by the thin rear plate132and the display panel110, and therefore may have less restriction as to a position of the opening. However, as exemplarily shown inFIG. 1, if the metal plate140and the rear cover150are sized to cover only a part of the multi-layer panel130, a part of the thin rear plate132may be exposed reward of the display device100. In this case, the opening may be formed only in a region covered by the metal plate140and the rear cover150.

FIGS. 6 and 7are rear views showing the metal plate140of the display device100according to the present disclosure. Similar to the thin rear plate132and the thin front plate131, the metal plate140may include a plurality of vertically aligned holes141a, and a plurality of lines141b, each of which includes the plurality of holes141a, may be horizontally spaced apart from one another. The lines141bmay be arranged at a constant interval, or may be densely arranged at a region where the greatest amount of heat is generated, or may be more densely arranged at a center region where the greatest amount of bending deformation occurs. That is, the density of the lines141bnear the central region of the display may be greater than a density of the lines141bnear lateral regions of the display.

Alternatively, as exemplarily shown inFIG. 7, a plurality of segment plates142may be arranged in a longer side direction. The segment plates142may be spaced apart from one another, and therefore gaps between the segment plates142compensate for increase in the length of each segment plate142, which may substantially prevent deformation of the metal plate140from having an effect on bending deformation of the entire display device100.

Providing the multi-layer panel130and the metal plate140, which are formed of metal materials and have greater rates of thermal deformation than the display panel110, with the opening or the plurality of segment plates142may compensate for length variation due to thermal expansion.

The adhesive layer115, which is interposed between the display panel110and the multi-layer panel130to couple the display panel110and the multi-layer panel130, may also undergo thermal expansion. However, unlike the display panel110or the multi-layer panel130, the adhesive layer115is soft and is not bent even when it is deformed.

That is, in the case in which the multi-layer panel130is greatly tensioned and the display panel110is less tensioned, length variation of the multi-layer panel130has a direct effect on the display panel110if the adhesive layer115firmly couples the two members to each other. However, if the adhesive layer115is gently deformed, the adhesive layer115may cancel out the length variation caused upon tensioning of the multi-layer panel130. As such, the display panel110may be less affected by thermal expansion of the multi-layer panel130.

That is, the adhesive layer115may serve not only to attach the display panel110and the multi-layer panel130to each other, but also to cancel deformation of the multi-layer panel130during thermal expansion, thereby preventing bending of the display panel110. Since the aforementioned two properties contradict each other, when considering only adhesive force, the adhesive layer115may be formed of a hard and highly adhesive material.

However, the adhesive layer115may be provided to have a high elongation percentage in order to compensate for thermal expansion of the multi-layer panel130as described above. To sufficiently cancel out deformation of the multi-layer panel130, the adhesive layer115may have an elongation percentage of about 800% or more.

FIG. 8is a rear view of the adhesive layer115of the display device100according to the present disclosure. The adhesive layer115may be configured to cover the entire display panel110as exemplarily shown inFIG. 8A. In this case, the adhesive layer115exhibits increased adhesive force, which may cause the display panel110to be bent according to deformation of the multi-layer panel130. On the other hand, if the adhesive layer115is configured to cover only a part of the display panel110as exemplarily shown inFIGS. 8B, 8C and 8D, the adhesive layer115may be easily extended. The adhesive layer115may be required to cover an area corresponding to 60% or more of the display panel110or the multi-layer panel130because the area of the adhesive layer115is associated with coupling force between the display panel110and the multi-layer panel130. The adhesive layer115may also be required to cover an area corresponding to 70% or more of the display panel110or the multi-layer panel130.

FIGS. 8B, 8C and 8Dshow the adhesive layer115configured to cover a two-third area that ofFIG. 8A. More specifically, a partial upper portion of the adhesive layer115may be omitted as exemplarily shown inFIG. 8B, or the adhesive layer115may be divided into a plurality of separate sections extending in a direction parallel to a shorter side as exemplarily shown inFIG. 8C. Alternatively, the adhesive layer115may be vertically and horizontally split into a plurality of separate sections as exemplarily shown inFIG. 8D.

FIG. 9is a graph showing bending deformation depending on arrangement of the adhesive layer115ofFIGS. 8A to 8D. In the graph, the line shows variation of a bending deformation degree and the least amount of deformation occurs in the case ofFIG. 8C. In consideration of the fact that an amount of horizontal deformation is great, the case ofFIG. 8Cadopting horizontally split sections suitable to sufficiently cancel the horizontal deformation may be the most effective to prevent transfer of thermal expansion of the multi-layer panel130to the display panel110.

The adhesive layer115may include a double-sided tape.FIG. 10is a sectional view showing the double-sided tape115as one embodiment of the adhesive layer115of the display device100according to the present disclosure. The double-sided tape115may be formed by applying adhesive115ato both surfaces of a resin layer115b. If the resin layer115bhas a high elongation percentage, the double-sided tape115may have a high elongation percentage.

As exemplarily shown inFIG. 10, when using the double-sided tape115including the porous resin layer115bhaving pores115c, the double-sided tape115is more easily extended. The double-sided tape115including the porous resin layer115bhas four times greater elongation percentage than a double-sided tape formed of Carbon Fiber Reinforced Plastics (CFRP).

FIG. 11is a rear view showing a separated state of the rear cover150of the display device100according to the present disclosure, andFIG. 12is a sectional view taken along the line A-A′ ofFIG. 11. A rigid bar160may be further provided at the rear surface of the multi-layer panel130so as to extend in a horizontal direction. The rigid bar160may prevent the front surface of the display panel110from being concavely bent.

The rigid bar160is a bar-shaped member and is formed of a material that is not easily bent. The rigid bar160may be fixed to PEM nuts161(or self-clinching nut), which may be inserted into the multi-layer panel130to protrude from a rear surface of the metal plate140, via screws163.

Although simply coupling the linear rigid bar160may prevent bending deformation of the display panel110in which both ends of the display panel110protrude forward and a center region of the display panel100protrudes rearward, it is possible to cancel deformation due to temperature increase when previously applying deformation force in an opposite direction.

FIG. 12is a sectional view showing a state in which the display panel110and the multi-layer panel130are coupled to the rigid bar160so as to centrally protrude forward at a center region thereof and protrude rearward at left and right ends thereof.

In the present embodiment, a PEM nut161alocated at the center region of the display and a PEM nut161blocated at a side region may have different lengths. As exemplarily shown inFIG. 12, the rigid bar160having a slightly bulged front surface may be fixed to the display panel110and the multi-layer panel130.

If the PEM nut161alocated at the center region of the multi-layer panel130is long and the PEM nut161blocated at either end of the multi-layer panel130is short, the rigid bar160or the multi-layer panel130may be kept in a bent state. Since the rigid bar160is harder than the multi-layer panel130, the multi-layer panel130is originally kept in a bent state. Therefore, before the display device100is driven, as exemplarily shown inFIG. 12, the multi-layer panel130slightly protrudes forward by a height difference a between the PEM nuts161aand161b.

Once the display device100begins driving, the front surface of the multi-layer panel130begins to be concavely deformed due to thermal expansion of the multi-layer panel130as the temperature of the display device100increase. In the present embodiment, such concave deformation of the front surface of the multi-layer panel130occurs in a state in which force has previously been applied in a direction opposite to the above deformation caused by thermal expansion such that the center region of the front surface of the multi-layer panel130slightly protrudes forward owing to provision of the rigid bar160and the PEM nuts161aand161bhaving a height difference. Therefore, after the multi-layer panel130has completely been deformed due to thermal expansion, the multi-layer panel130exhibits less deformation than the case in which the rigid bar160is not used.

The above Table 1 shows a deformation degree of the panel depending on power consumption of the display device100. A temperature difference of about 1° C. occurs per 10 W. Assuming that a height difference between the PEM nut161blocated at the end and the PEM nut161alocated at the center region is 2 mm, the front surface of the display device100is concavely deformed even when power consumption is 282 W, and thus deviation between the end and the center region is only 2 mm.

As is apparent from the above description, according to at least one embodiment of the present disclosure, the opening formed in the multi-layer panel130may be reduced in size to compensate for deformation of the multi-layer panel130due to thermal expansion, which may minimize increase in the length of the entire multi-layer panel130.

Further, as the adhesive layer115is extended to correspond to the thermally deformed multi-layer panel130, it may be possible to substantially prevent thermal expansion of the multi-layer panel130from having a negative effect on the display panel110, which may minimize concave deformation of the front surface of the display device100.

Furthermore, owing to providing the rigid bar160that preloads a prescribed amount of force required to keep the center region of the multi-layer panel130in a slightly forwardly bulged state, it is possible to reduce the amount of deformation of the forwardly concave front surface even if the multi-layer panel130thermal expands.

As broadly described herein, the present disclosure is directed to a display device that substantially obviates one or more problems due to limitations and disadvantages of the related art. One object of the present disclosure is to provide a display device having a sandwich honeycomb panel to minimize bending deformation due to thermal expansion.

To achieve these objects and other advantages and in accordance with the purpose of the disclosure, as embodied and broadly described herein, a display device may include a display panel, a sandwich honeycomb panel including a thin front plate located toward the display panel, a thin rear plate disposed on a rear surface of the thin front plate, and a honeycomb mesh interposed between the thin front plate and the thin rear plate, the honeycomb mesh having a plurality of hexagonal unit cells, and a metal plate coupled to a rear surface of the sandwich honeycomb panel such that a drive board is seated on the metal plate, wherein at least one of the thin front plate or the thin rear plate includes at least one opening formed parallel to a shorter side of the display device.

The opening may include a plurality of holes arranged parallel to the shorter side.

The opening may be a slit extending in a direction parallel to the shorter side.

The at least one opening may include a plurality of openings spaced apart from one another in a direction parallel to a longer side of the display device.

Distances between the openings may be reduced at a center region of the display device and may be increased at both ends of the display device.

The display device may further include a rear cover coupled to the rear surface of the sandwich honeycomb panel, and the opening of the thin rear plate may be formed only in a portion of the thin rear plate covered by the rear cover.

The metal plate may include an opening formed parallel to the shorter side of the display device.

The metal plate may further include a plurality of segment plates arranged in a direction parallel to a longer side of the display device, and the segment plates may be spaced apart from one another.

The display device may further include an adhesive layer interposed between the display panel and the sandwich honeycomb panel, and the adhesive layer may be divided into a plurality of sections so as to be separately arranged in a plurality of regions of a rear surface of the display panel.

The sections of the adhesive layer may be spaced apart from one another in a direction parallel to a longer side of the display device.

An area of the adhesive layer may be less than 60% or 70% of an area of the display panel.

The adhesive layer may be a double-sided tape formed by applying adhesive to both surfaces of a porous resin layer.

The adhesive layer may have an elongation percentage of about 800% or more.

The display device may further include a plurality of PEM nuts arranged on a rear surface of the metal plate in a direction parallel to a longer side of the display device, and a rigid bar coupled to the rear surface of the metal plate via screws inserted into the PEM nuts.

A height of the PEM nuts located at both ends of the display device may be less than a height of the PEM nut located at another position.

In one embodiment, a display device may include a display panel, a multi-layered panel provided adjacent the display panel and including a front plate located toward the display panel, a rear plate provided parallel to the front plate, and a honeycomb pattern mesh interposed between the front plate and the rear plate, the honeycomb pattern mesh having a plurality of hexagonal cells to form a honeycomb pattern, and a metal plate coupled to a rear surface of the multi-layered panel and a drive board provided on the metal plate. At least one of the front plate or the rear plate may include at least one opening that extends parallel to a shorter side of the display device.

The opening may include a plurality of holes which are arranged in a line that extends parallel to the shorter side. The opening may be a slit formed through the front plate or the rear plate that extends parallel to the shorter side. A plurality of the openings may be provided to be spaced apart from one another in a direction parallel to a longer side of the display device. Moreover, the openings in a central region of the display device may be arranged a first distance from each other and the openings at lateral regions of the display device may be arranged a second distance from each other, the second distance being greater than the first distance.

A rear cover may be provided coupled to the rear surface of the multi-layered panel, wherein the at least one opening provided on the rear plate is formed only in a region of the rear plate covered by the rear cover. The metal plate may include at least one opening formed parallel to the shorter side of the display device. The metal plate may include a plurality of segment plates arranged in a direction parallel to a longer side of the display device, and wherein the segment plates are spaced apart a prescribed distance from one another.

An adhesive layer may be interposed between the display panel and the multi-layered panel, wherein the adhesive layer is divided into a plurality of sections which are each arranged separately in a plurality of regions of a rear surface of the display panel. The sections of the adhesive layer may be spaced apart from one another in a direction parallel to a longer side of the display device. An area of the adhesive layer may be less than 60% or 70% of an area of the display panel. The adhesive layer may be a double-sided tape that includes a porous resin layer and an adhesive provided on both surfaces of the porous resin layer. Moreover, the adhesive layer may be an elongation percentage of about 800% or more.

A plurality of PEM nuts may be arranged on a rear surface of the metal plate, and a bar may be provided on the rear surface of the metal plate parallel to a longer side of the display device and positioned to correspond to the PEM nuts, the bar being coupled to the rear surface of the metal plate by screws inserted into the PEM nuts. A height of the PEM nuts located in lateral regions of the display device may be less than a height of the PEM nut located in other regions.

In one embodiment, a display device may include a display panel, an adhesive layer having a prescribed pattern provided on a rear surface of the display panel, a multi-layered panel coupled to the display panel by the adhesive layer, the multi-layered panel including a mesh panel layer having a honeycomb pattern, a metal plate provided adjacent the multi-layered panel, a bar provided on the metal plate, and a rear cover provided to cover the metal plate. The display panel may have a first rate of thermal expansion, the multi-layered panel may have a second rate of thermal expansion, and the metal plate may have a third rate of thermal expansion. Moreover, the multi-layered panel and the metal plate may thermally expand at a greater rate than the display panel with respect to temperature.

The multi-layered panel may include a first metal panel layer, a second metal panel layer, and the mesh panel layer may be provided between the first and second metal panel layers, the mesh panel layer having a plurality of hexagonal regions provided adjacent to each other to form the honeycomb pattern. At least one of the multi-layered panel or the metal plate may include a plurality of holes, the plurality of holes aligned to form a plurality of vertical lines which are provided a prescribed distance from an adjacent vertical line of holes. A density of the plurality of vertical lines may be greater in a central region of the display panel than a lateral region of the display panel. Moreover, the bar may be provided horizontally across the metal plate and configured to bend the display panel to have a prescribed amount of convex curvature, the prescribed amount of convex curvature corresponding to an amount of deformation of the display panel caused by thermal expansion.