Backlight unit and display device

Abstract

Provided is a backlight unit comprising: an assembly; a diffuser plate for emitting incident light of the optical assembly to the front side thereof; and an optical sheet positioned on the front side of the diffuser plate, wherein the diffuser plate includes: a plurality of prismatic protrusions and recesses formed on the front side thereof; and a plurality of bubbles positioned inside the diffuser plate.

Description

Backlight unit and display device

[0001] The present invention relates to a backlight unit having a simplified layered structure of the backlight unit and a display device including the same.

[0002] As the information society develops, the demand for display devices is also increasing in various forms, and in response to this, recent display devices include liquid crystal displays (LCDs), field emission displays (FEDs), plasma display panels (PDPs), and electroluminescence devices.

[0003] The liquid crystal panel of the liquid crystal display device includes a liquid crystal layer and a TFT substrate and a color filter substrate facing each other with the liquid crystal layer interposed therebetween, and can display an image using light provided from a backlight unit.

[0004] As an example of an electroluminescent device (ELD), an active-matrix type organic light-emitting display device is commercially available. Because OLED displays are self-luminous, they do not require a backlight and offer advantages over liquid crystal displays (LCDs) in terms of response speed, viewing angle, and other factors. Therefore, they are attracting attention as next-generation displays.

[0005] However, high-performance, high-definition OLED TVs are facing price competitiveness issues, so technology development is underway to achieve similar advantages of OLED with LCD. Liquid crystal displays (LCDs) display color using light from a backlight unit, which transmits light to the LCD panel using multiple optical sheets with various uneven shapes.

[0006] However, there is a problem that optical interference occurs by using multiple optical sheets and manufacturing costs increase depending on the number of sheets, so research is being conducted on a method to transmit light to the liquid crystal panel more effectively while reducing the number of parts.

[0007] The present invention aims to provide a backlight unit having a reduced number of optical sheets and a display device including the same.

[0008] A backlight unit is provided, comprising: an optical assembly; a diffuser plate that emits incident light of the optical assembly to the front; an optical sheet positioned on the front of the diffuser plate; the diffuser plate having a plurality of prism projections formed on the front; and a plurality of bubbles positioned inside the diffuser plate.

[0009] The above bubbles may have a size in the horizontal direction greater than a size in the thickness direction.

[0010] The horizontal size of the bubbles may be at least four times the size in the thickness direction.

[0011] The horizontal size of the above bubbles may be larger than the pitch of the prism irregularities.

[0012] The pitch of the above prism irregularities can be 150um or more.

[0013] The height of the above prism irregularities may be 50 um or more and 200 um or less.

[0014] The rear surface includes a recessed pattern located on the rear surface of the above-mentioned diffuser plate, and the rear surface recessed pattern may include a wedge-shaped groove.

[0015] The above diffuser plate may include a scattering agent in a portion other than the prism protrusions.

[0016] The above optical sheet may include one prism sheet or one micro lens sheet.

[0017] The above optical sheet may include a diffuser sheet positioned in front of one prism sheet or one micro lens sheet.

[0018] According to another aspect of the present invention, a display device is provided, comprising: a liquid crystal panel; and a backlight unit supplying light from a rear surface of the liquid crystal panel, wherein the backlight unit comprises: an optical assembly; a diffusion plate emitting incident light of the optical assembly to the front; and an optical sheet positioned on the front surface of the diffusion plate, wherein the diffusion plate comprises a plurality of prism protrusions formed on the front surface; and a plurality of bubbles positioned inside the diffusion plate.

[0019] The backlight unit of the present invention has the effect of increasing brightness through a light guide plate with a prism added.

[0020] Additionally, by reducing the number of prism sheets, the thickness of the backlight unit can be reduced, thereby ensuring price competitiveness.

[0021] Additionally, the failure rate of the backlight unit due to the optical sheet can be reduced by reducing the application of the prism sheet.

[0022] The effects that can be obtained from the present invention are not limited to the effects mentioned above, and other effects not mentioned can be clearly understood by a person having ordinary skill in the art to which the present invention belongs from the description below.

[0023] Fig. 1 is a perspective view showing an example of a display device of the present invention.

[0024] Figure 2 is an exploded perspective view showing an example of a display device of the present invention.

[0025] Fig. 3 is an embodiment of a backlight unit of a display device.

[0026] Figure 4 is a drawing illustrating a conventional backlight unit.

[0027] Figures 5 to 8 are cross-sectional views illustrating several embodiments of the backlight unit of the present invention.

[0028] Figures 9 to 12 illustrate modified embodiments of the backlight unit (520) of Figure 7.

[0029] Hereinafter, embodiments disclosed in this specification will be described in detail with reference to the attached drawings. Regardless of the drawing numbers, identical or similar components will be given the same reference numbers, and redundant descriptions thereof will be omitted. The suffixes "module" and "part" used for components in the following description are assigned or used interchangeably only for the convenience of writing the specification, and do not in themselves have distinct meanings or roles. In addition, when describing the embodiments disclosed in this specification, if it is determined that a specific description of a related known technology may obscure the gist of the embodiments disclosed in this specification, a detailed description thereof will be omitted. In addition, the attached drawings are only intended to facilitate easy understanding of the embodiments disclosed in this specification, and the technical ideas disclosed in this specification are not limited by the attached drawings, and should be understood to include all modifications, equivalents, and substitutes included in the spirit and technical scope of the present invention.

[0030] Terms that include ordinal numbers, such as first, second, etc., may be used to describe various components, but the components are not limited by these terms. These terms are used solely to distinguish one component from another.

[0031] When a component is referred to as being "connected" or "connected" to another component, it should be understood that it may be directly connected or connected to that other component, but that there may be other components intervening. Conversely, when a component is referred to as being "directly connected" or "connected" to another component, it should be understood that there are no other components intervening.

[0032] Singular expressions include plural expressions unless the context clearly indicates otherwise.

[0033] In this application, terms such as “include” or “have” are intended to specify the presence of a feature, number, step, operation, component, part or combination thereof described in the specification, but should be understood not to exclude in advance the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts or combinations thereof.

[0034] Meanwhile, the display device (100) described herein is an intelligent display device (100) that adds computer support functions to, for example, a broadcast reception function. While remaining faithful to the broadcast reception function, it can be equipped with an Internet function and other functions, thereby providing a more convenient interface such as a manual input device, touch screen, or space remote control. In addition, it can be connected to the Internet and a computer with support for wired or wireless Internet functions, and can perform functions such as email, web browsing, banking, or games. A standardized, general-purpose operating system (OS) can be used for these various functions.

[0035] Accordingly, the display device (100) described in the present invention can perform various user-friendly functions, for example, since various applications can be freely added or deleted on a general-purpose OS kernel. More specifically, the display device (100) can be, for example, a network TV, HBB TV, smart TV, etc., and in some cases, can also be applied to a smartphone.

[0036] Fig. 1 is a front perspective view illustrating an example of a display device of the present invention. The display device (100) of the present invention may have a rectangular body including a pair of long sides and a pair of short sides. It may include a first long side (First Long Side, LS1), a second long side (Second Long Side, LS2) opposite the first long side (LS1), a first short side (First Short Side, SS1) adjacent to the first long side (LS1) and the second long side (LS2), and a second short side (Second Short Side, SS2) opposite the first short side (SS1).

[0037] Although the long side extending horizontally and the short side extending vertically are depicted in the drawing, the long side and the short side may be of equal length, and the long side may also be arranged vertically.

[0038] For convenience of explanation, the long side is defined as the side extending in the horizontal direction (x-axis direction) and the short side is defined as the side extending in the vertical direction (y-axis direction). However, as mentioned above, the present invention is not limited thereto.

[0039] The first direction (DR1) may be a direction parallel to the long side (LS1, LS2) of the display panel (100), and the second direction (DR2) may be a direction parallel to the short side (SS1, SS2) of the display panel (100). The third direction (DR3) may be a direction perpendicular to the first direction (DR1) and / or the second direction (DR2).

[0040] The side of the display device (100) that displays an image may be referred to as the front or front surface. When the display device (100) displays an image, the side from which the image cannot be observed may be referred to as the rear or back surface. When the display device displays an image, the side from which the image cannot be observed may be referred to as the rearward direction or rear side (rear surface).

[0041] When viewing the display from the front or front, the first long side (LS1) may be referred to as the upper side or upper surface. Similarly, the second long side (LS2) may be referred to as the lower side or lower surface. Similarly, the first short side (SS1) may be referred to as the right side or right surface, and the second short side (SS2) may be referred to as the left side or left surface.

[0042] The display device may include a display unit (120) that outputs images. The control unit (180) may convert image signals, data signals, OSD signals, control signals, or the like processed by the control unit or received from the interface unit to generate a driving signal. The display unit (150) may include a display panel having a plurality of pixels.

[0043] The plurality of pixels provided on the display panel may have RGB sub-pixels. Alternatively, the plurality of pixels provided on the display panel may have RGBW sub-pixels. The display unit (150) may convert image signals, data signals, OSD signals, control signals, etc. processed by the control unit (180) to generate driving signals for the plurality of pixels.

[0044] The display device (100) includes a display unit (120) that occupies most of the front surface area and a case that covers the rear side of the display unit (120) and packages the display unit (120).

[0045] The display unit (150) can be a PDP (Plasma Display Panel), LCD (Liquid Crystal Display), OLED (Organic Light Emitting Diode), a flexible display, etc., and may also be a 3D display. The 3D display unit (150) can be divided into a glasses-free type and a glasses type.

[0046] LCD displays rely on a backlight unit to provide light, as the LCD itself is unable to emit light on its own. The backlight unit is a device that evenly distributes light from the LEDs to the liquid crystal display located at the front. As backlight units become thinner, thinner LCDs can be realized.

[0047] Fig. 2 is an exploded view of the display device of the present invention. Referring to Fig. 2, the display unit (120) of the present invention is an LCD display including a display panel (510) and a backlight unit (520).

[0048] The front cover (110) may cover at least a portion of the front and side surfaces of the display panel (510). The front cover (110) may be divided into a front cover positioned on the front side of the display panel (510) and a side cover positioned on the side surface of the display panel (510). The front cover and the side cover may be configured separately. Either the front cover or the side cover may be omitted.

[0049] A display panel (510) is provided on the front of a display device (100) and can display an image. The display panel (510) can display an image by having a plurality of pixels output RGB (red, green, or blue) according to timing for each pixel. The display panel (510) can be divided into an active area where an image is displayed and a de-active area where an image is not displayed. The display panel (510) can include a front substrate and a rear substrate that face each other with a liquid crystal layer therebetween.

[0050] The front substrate may include a plurality of pixels each composed of red (R), green (G), and blue (B) sub-pixels. The front substrate may output light corresponding to the color red, green, or blue according to a control signal.

[0051] The rear substrate may include switching elements. The rear substrate may switch the pixel electrode. For example, the pixel electrode may change the molecular arrangement of the liquid crystal layer according to an externally applied control signal. The liquid crystal layer may include liquid crystal molecules. The liquid crystal molecules may change their arrangement in response to a voltage difference generated between the pixel electrode and the common electrode. The liquid crystal layer may transmit light provided from the backlight unit (520) to the front substrate or block it.

[0052] The backlight unit (520) may be positioned at the rear of the display panel (510). The backlight unit (520) may include light sources. The backlight unit (520) may be coupled to the frame (130) at the front of the frame (130).

[0053] The backlight unit (520) may be driven by a full driving method or a partial driving method such as local dimming, impulsive, etc. The backlight unit (520) may include an optical sheet (521) and an optical layer (522).

[0054] A guide panel (530) may be included to align the positions of the display panel (510) and the backlight unit (520). The guide panel (530) has a frame shape with four sides, and the display panel (510) and the backlight unit (520) can be mounted on the front.

[0055] The optical sheet (521) can ensure that light from the optical assembly (524) is evenly transmitted to the display panel (510). The optical sheet (521) may be composed of layers. For example, the optical sheet (521) may include a prism sheet, a diffusion sheet, etc.

[0056] The optical sheet (521) may be provided with a coupling portion. The coupling portion may be coupled to the front cover (110), the frame (130), and / or the back cover (120). Alternatively, the coupling portion may be fastened to a structure formed or coupled on the front cover (110), the frame (130), and / or the back cover (120).

[0057] The frame (130) may serve to support components of the display device (100). For example, components such as a backlight unit (520) may be combined with the frame (130). The frame (130) may be made of a metal material such as an aluminum alloy.

[0058] The back cover (120) may be located on the back or rear of the display device (100). The back cover (120) may be coupled to the frame (130) and / or the front cover (110). For example, the back cover (120) may be an injection-molded product made of resin material.

[0059] FIG. 3 is a drawing illustrating one embodiment of a backlight unit (520) of a display device (100).

[0060] The backlight unit (520) may include an optical layer (522) including a 5241 optical assembly (524), a reflective sheet (525), and a diffuser plate (526), ​​and an optical sheet (521) positioned on the front side of the optical layer (522).

[0061] This embodiment is characterized in that a direct-type backlight unit (520) is arranged in an array with a light assembly (524) toward the back of a display panel (510). The light assembly (524) may include a substrate (5241) and an LED (5242) mounted on the substrate.

[0062] The substrate (5241) may be configured in the form of a plurality of straps extending in a first direction and spaced apart at a predetermined interval in a second direction perpendicular to the first direction.

[0063] At least one LED (5242) may be mounted on the substrate (5241). An electrode pattern for connecting the adapter and the LED (5242) may be formed on the substrate (5241). For example, a carbon nanotube electrode pattern for connecting the LED (5242) and the adapter may be formed on the substrate (5241).

[0064] The substrate (5241) may be composed of at least one of polyethylene terephthalate (PET), glass, polycarbonate (PC), and silicon. The substrate (5241) may be a printed circuit board (PCB) on which at least one LED (5242) is mounted.

[0065] On the substrate (5241), LEDs (5242) can be arranged at a predetermined interval in the first direction. The diameter of the LEDs (5242) can be larger than the width of the substrate (5241). That is, it means that the diameter can be larger than the length of the substrate (5241) in the second direction.

[0066] The LED (5242) may be a light emitting diode (LED) chip or a light emitting diode package including at least one light emitting diode chip.

[0067] The LED (5242) may be a colored LED that emits at least one color, such as red (R), blue (B), green (G), or a white LED. The colored LED may include at least one of a red LED, a blue LED, and a green LED.

[0068] A reflective sheet (525) may be positioned on the front side of the substrate (5241). The reflective sheet (525) may be positioned on an area of ​​the substrate (5241) other than an area where the LED (5242) is formed. The reflective sheet (525) may have a plurality of through holes (525a).

[0069] The reflective sheet (525) can reflect light emitted from the LED (5242) toward the front side. In addition, the reflective sheet (525) can re-reflect light reflected from the diffuser (526).

[0070] A diffuser supporter (525b) may be further included to maintain a gap between the LED (5242) and the diffuser (526) so that the light of the LED (5242) is evenly supplied to the back surface of the diffuser (526).

[0071] The reflective sheet (525) may include at least one of a metal and a metal oxide that is a reflective material. For example, the reflective sheet (525) may include a metal and / or metal oxide having a high reflectivity, such as at least one of aluminum (Al), silver (Ag), gold (Au), and titanium dioxide (TiO2).

[0072] A resin may be deposited on the LED (5242) and / or the reflective sheet (525). The resin may serve to diffuse light emitted from the LED (5242). The diffuser plate (526) may diffuse light emitted from the LED (5242) upward.

[0073] The optical sheet (521) may be positioned in front of the diffuser plate (526). The rear surface of the optical sheet (521) may be in close contact with the diffuser plate (526), ​​and the front surface of the optical sheet (521) may be in close contact with the rear surface of the display panel (510, see FIG. 1).

[0074] The optical sheet (521) may include at least one sheet. Specifically, the optical sheet (521) may include one or more prism sheets and / or one or more diffusion sheets. The plurality of sheets included in the optical sheet (521) may be in an adhesive and / or closely adhered state.

[0075] The optical sheet (521) may be composed of a plurality of sheets (521a, 521b) having different functions. For example, it may be one diffusion sheet (521a) and two prism sheets (521b).

[0076] The diffusion sheet (521) can prevent light from being partially concentrated from the diffusion plate (526), ​​thereby making the light distribution more uniform. The prism sheet can collect light from the diffusion sheet (521a) and provide light to the display panel (510).

[0077] The bonding portion may be formed on at least one of the edges or sides of the optical sheet (521). The bonding portion may be formed on at least one of the first to third optical sheets (521a to 521c).

[0078] The bonding portion may be formed on the long side of the optical sheet (521). The bonding portion formed on the first long side and the bonding portion formed on the second long side may be asymmetric. For example, this means that the positions and / or numbers of the bonding portions on the first long side and the bonding portions on the second long side may be different from each other.

[0079] Fig. 4 is a drawing illustrating a conventional backlight unit (520). The conventional backlight unit (520) may be composed of a diffusion plate (526) positioned in front of an LED (5242) and an optical sheet (521) positioned in front of the diffusion plate (526).

[0080] The diffuser (526) may include a scattering agent (5261) that scatters light to turn the point light source of the LED (5242) into a surface light source. The optical sheet (521) may include a prism sheet (521b), and since it is difficult to obtain a sufficient light-gathering effect with one sheet, two or more prism sheets (521b) are used.

[0081] The prism sheet (521b) has a predetermined thickness due to the prism protrusions (5265), and the thickness of the base film (PET, 5211) for forming the prism protrusions (5265) is also added. Therefore, when multiple prism sheets (521b) are used, there is a problem that the thickness of the backlight unit (520) increases and the cost increases.

[0082] Figures 5 to 8 are cross-sectional views illustrating various embodiments of a backlight unit (520) of the present invention. The backlight unit (520) of the present invention is characterized by forming a prism projection (5265) on the front surface of a diffuser plate (526) to replace the conventional prism sheet (521b) of Figure 4.

[0083] Referring to FIG. 5, the backlight unit (520) of the present invention forms prism projections (5265) on the front surface of the diffusion plate (526), ​​thereby reducing the number of prism sheets (521b) that were used in the past from two to one.

[0084] The present invention, which includes prism protrusions (5265) formed on a diffuser plate (526) instead of a prism sheet (521b), can omit the base film (5211) of the prism sheet (521b) and reduce the tolerance due to the air gap between each prism sheet (521b), thereby reducing the overall thickness of the backlight unit (520).

[0085] The prism protrusions (5265) may have a protrusion having a triangular cross-section, similar to the protrusions formed on the prism sheet (521b), and may be formed in a shape that extends long and includes valleys and peaks. The valleys and peaks may be formed in a straight line or a curve, and may not necessarily be continuous but may be formed by segmenting them into a predetermined length. Alternatively, the prism protrusions (5265) may be formed in a quadrangular pyramidal shape forming an array.

[0086] The prism projections (5265) are attached to the front surface of the diffuser plate (526) to form an integral body, but the purpose of the prism projections (5265) is to collect the light diffused from the diffuser plate (526), ​​and therefore the prism projections (5265) do not include the scattering agent (5261) added to the diffuser plate (526). The prism projections (5265) can be additionally formed on the front surface of the diffuser plate (526) using acrylic resin, or the diffuser plate (526) including the scattering agent (5261) can be manufactured after the prism projections (5265) are formed.

[0087] The prism projection (5265) can be manufactured using at least one of acrylic, urethane, epoxy and melamine-based polymers or copolymers or terpolymers, such as unsaturated polyester, methyl methacrylate, ethyl methacrylate, isobutyl methacrylate, normal butyl methacrylate, normal butyl methyl methacrylate, acrylic acid, methacrylic acid, hydroxyethyl methacrylate, hydroxypropyl methacrylate, hydroxy ethyl acrylate, acrylamide, methylolacrylamide, glycidyl methacrylate, ethyl acrylate, isobutyl acrylate, normal butyl acrylate and 2-ethylhexyl acrylate, in addition to acrylic resin.

[0088] The backlight unit (520) having prism projections (5265) formed on the front side has a different structure from the conventional backlight unit (520) in that there is no air layer between the prism projections (5265) and the diffusion plate (526), ​​and thus the path of light is different. The light supplied to the prism projections (5265) without passing through the air layer is not supplied in the vertical direction as shown in FIG. 5, but is spread laterally. Unlike the light that passes through the prism sheet (521b) of FIG. 4 being supplied in the front direction, much of the light is spread laterally, and thus the luminance of the embodiment of FIG. 5 is only 81% of that of the conventional backlight unit (520) of FIG. 4.

[0089] Accordingly, as in the embodiment illustrated in Fig. 6, bubbles (5262) ​​can be formed in the diffuser plate (526) so that light supplied to the diffuser plate (526) passes through an air layer. When passing through an air layer, the light collection efficiency is higher than in the embodiment of Fig. 5, and the brightness can be improved to 87% compared to the conventional backlight unit (520).

[0090] However, the spherical bubbles (5262) ​​have the effect of scattering light depending on the angle of incidence of the light, and thus can form an optical path in a different manner from the light passing through the air layer between the conventional diffusion plate (526) and the prism sheet (521b).

[0091] Accordingly, as shown in Fig. 7, the thickness of the bubbles (5262) ​​included in the diffusion plate (526) can be formed thinly, and bubbles (5262) ​​having a shape close to a disk shape can be used. Through the disk-shaped bubbles (5262) ​​of the diffusion plate (526), ​​an effect similar to that of the air layer between the conventional diffusion plate (526) and the prism sheet (521b) can be obtained.

[0092] The bubbles (5262) ​​can be formed by adding a foaming agent when forming the diffusion plate (526) and thermally decomposing it. At this time, in order to form the shape of the bubbles (5262) ​​formed in a spherical shape into a disk shape as shown in Fig. 7, the diffusion plate (526) can be stretched horizontally or compressed in the thickness direction to form bubbles (5262) ​​whose diameter is larger than the thickness.

[0093] As shown in Fig. 7, the optical path is almost similar to the embodiment of Fig. 4, and light can be emitted toward the front, so the light collection efficiency is increased, and the light efficiency can be 94% or more compared to the embodiment of Fig. 4.

[0094] Fig. 8 is a table showing the difference between the prism sheet (521b) and the prism protrusions (5212). The larger the size of the prism protrusions (5265), the greater the light refraction phenomenon, which increases the light collection efficiency. Since the present invention can omit the base film (5211) of the prism sheet (521b), it is effective in increasing the light collection efficiency to implement the prism protrusions (5265) on the front surface of the diffuser plate (526) to have a height of 50 um, which is larger than the prism protrusions (5212) of the conventional prism sheet (521b).

[0095] However, there is a problem that the visibility of the prism irregularities (5265) increases when the size of the prism irregularities (5265) is large, so the height of the prism irregularities (5265) is appropriately 200 um, and can be configured to be 100 um or less in consideration of the increase in visibility and the thickness of the backlight unit (520).

[0096] Depending on the angle of the prism protrusions (5265), the pitch of the prism protrusions (5265) may vary, but may be formed at intervals of approximately twice the height or more. The prism protrusions (5265) of the diffusion plate (526) may be formed to be larger in size than the prism protrusions (5265) of the prism sheet (521b), thereby improving light collection efficiency.

[0097] Figures 9 to 12 illustrate modified embodiments of the backlight unit (520) of Figure 7. As illustrated in Figure 9, instead of the prism sheet (521b), a micro lens sheet (521c) including a plurality of spherical micro lenses may be used. Alternatively, as illustrated in Figure 10, a diffusion sheet (521a) may be further included so that light collected through the prism sheet (521b) forms a surface light source.

[0098] The embodiment illustrated in Fig. 11 is characterized by forming a rough pattern (5264) on the back surface of the diffuser plate (526) to increase light collection efficiency. The purpose of the diffuser plate (526) is to evenly distribute light supplied from the LED (5242), and the rough pattern (5264) on the back surface serves to guide light that is spread too much laterally toward the front.

[0099] As shown in Fig. 11, it includes a wedge-shaped groove, and the groove may be flat as in Fig. 11 or may be formed in a sharp prism shape as in Fig. 12. The rear uneven pattern (5264) may be formed of the same material as the diffuser plate (526), ​​unlike the prism unevenness (5265) located on the front of the diffuser plate (526). Therefore, since it may include a scattering agent (5261), it may be manufactured using a mold having a rear uneven pattern (5264) when manufacturing the diffuser plate (526).

[0100] As seen above, the backlight unit (520) of the present invention has the effect of increasing brightness through a light guide plate with a prism added.

[0101] In addition, by reducing the quantity of prism sheets (521b), the thickness of the backlight unit (520) can be reduced and price competitiveness can be secured.

[0102] In addition, the failure rate of the backlight unit (520) by the optical sheet (521) can be reduced by reducing the application of the prism sheet (521b).

[0103] The above detailed description should not be construed as limiting in any respect and should be considered illustrative only. The scope of the present invention should be determined by a reasonable interpretation of the appended claims, and all modifications within the equivalent scope of the present invention are intended to be included within the scope of the present invention.

[0104] With respect to various embodiments for implementing the present invention, duplicate descriptions are omitted as they have been described above in the previous table of contents, Best Mode for Carrying Out the Invention.

[0105] Since the present invention can be applied to display devices in various fields, its industrial applicability is recognized.

Claims

1. Optical assembly; A diffuser plate that emits incident light of the above optical assembly to the front; and Including an optical sheet positioned on the front of the above diffuser, The above diffuser plate Multiple prism projections formed on the front; and A backlight unit comprising a plurality of bubbles positioned inside the above diffuser plate.

2. In paragraph 1, A backlight unit characterized in that the bubbles have a horizontal size larger than a thickness size.

3. In paragraph 2, A backlight unit characterized in that the horizontal size of the bubbles is at least four times the size in the thickness direction.

4. In paragraph 1, A backlight unit characterized in that the horizontal size of the bubbles is larger than the pitch of the prism protrusions.

5. In paragraph 1, A backlight unit characterized in that the pitch of the prism projections is 150 um or more.

6. In paragraph 1, A backlight unit characterized in that the height of the prism protrusion is 50 um or more and 200 um or less.

7. In paragraph 1, Including a back surface rough pattern located on the back surface of the above diffuser plate, A backlight unit characterized in that the above rear surface uneven pattern includes a wedge-shaped groove.

8. In paragraph 1, A backlight unit characterized in that the above diffusion plate includes a scattering agent in a portion excluding the prism protrusions.

9. In paragraph 1, The above optical sheet A backlight unit characterized by comprising one prism sheet or one micro lens sheet.

10. In paragraph 9, A backlight unit characterized in that the optical sheet includes a diffuser sheet positioned on the front side of one prism sheet or one micro lens sheet.

11. Liquid crystal panel; and Includes a backlight unit that supplies light from the back of the liquid crystal panel, The above backlight unit, optical assembly; A diffuser plate that emits incident light of the above optical assembly to the front; and Including an optical sheet positioned on the front of the above diffuser, The above diffuser plate Multiple prism projections formed on the front; and A display device comprising a plurality of bubbles positioned inside the above diffuser plate.

Images