KR20240001001A - Display apparatus - Google Patents

Abstract

A display device may include a liquid crystal panel and a backlight unit configured to provide light to the liquid crystal panel. The backlight unit includes a substrate extending in a first direction, a light emitting diode mounted on the substrate, a refractive cover covering the light emitting diode to refract light emitted from the light emitting diode, and a refractive cover to cover the refractive cover. The lens coupled to the substrate may include a lens whose bottom length in a second direction perpendicular to the first direction is longer than the bottom length in the first direction.

Description

Display device {DISPLAY APPARATUS}

The disclosed invention relates to a display device including a backlight unit.

A display device is a type of output device that converts acquired or stored electrical information into visual information and displays it to the user.

The display device may include a liquid crystal panel and a back light unit (BLU) that provides light to the liquid crystal panel.

The backlight unit may include a bar type substrate and a plurality of point light sources provided on the substrate.

In general, a backlight unit including a bar-type substrate has the advantage of being advantageous in terms of manufacturing cost.

One aspect of the disclosed invention seeks to provide a display device that includes a backlight unit that includes a bar-type substrate and has uniform brightness while reducing manufacturing costs.

One aspect of the disclosed invention seeks to provide a display device including a backlight unit that improves luminance non-uniformity caused by differences in the spacing between two adjacent substrates and the spacing between two adjacent light sources on the substrate.

One aspect of the disclosed invention seeks to provide a backlight unit including a light source configured such that the amount of light emitted in a first direction is greater than the amount of light emitted in a second direction perpendicular to the first direction, and a display device including the same. .

A display device according to an embodiment may include a liquid crystal panel and a backlight unit configured to provide light to the liquid crystal panel. The backlight unit includes a substrate extending in a first direction, a light emitting diode mounted on the substrate, a refractive cover covering the light emitting diode to refract light emitted from the light emitting diode, and a refractive cover to cover the refractive cover. The lens coupled to the substrate may include a lens whose bottom length in a second direction perpendicular to the first direction is longer than the bottom length in the first direction.

A display device may include a liquid crystal panel and a backlight unit configured to provide light to the liquid crystal panel. The backlight unit includes a plurality of substrates each extending along a first direction, a plurality of substrates spaced apart from each other at a first interval along a second direction perpendicular to the first direction, and each of the plurality of substrates. A plurality of light emitting diodes mounted, the plurality of light emitting diodes being spaced apart from each other along the first direction at a second interval smaller than the first interval, and the plurality of light emitting diodes configured to refract light emitted from each of the plurality of light emitting diodes. A plurality of refractive covers covering each of the light emitting diodes and a plurality of lenses provided to cover each of the plurality of refractive covers, wherein a bottom length in the second direction is longer than a bottom length in the first direction. may include a lens.

According to one aspect of the disclosed invention, it is possible to provide a display device including a backlight unit that includes a bar-type substrate and has uniform luminance while reducing manufacturing costs.

According to one aspect of the disclosed invention, a display device including a backlight unit that improves luminance non-uniformity caused by differences in the spacing between two adjacent substrates and the spacing between two adjacent light sources on the substrates can be provided.

According to one aspect of the disclosed invention, there is provided a backlight unit including a light source configured such that the amount of light emitted in a first direction is greater than the amount of light emitted in a second direction perpendicular to the first direction, and a display device including the same. You can.

Figure 1 shows an example of the appearance of a display device according to an embodiment.
Figure 2 shows an example of the structure of a display device according to an embodiment.
Figure 3 shows an example of a liquid crystal panel included in a display device according to an embodiment.
Figure 4 shows an example of an optical sheet and a diffusion plate in a display device according to an embodiment.
FIG. 5 is a diagram illustrating a backlight unit in a display device according to an embodiment.
Figure 6 is an enlarged view of A in Figure 5.
FIG. 7 is a diagram illustrating a substrate, a light emitting diode, a refractive cover, and a lens in a display device according to an embodiment.
FIG. 8 shows an example of a cross section of a light emitting diode along line B-B' in FIG. 7.
Figure 9 is a cross-sectional view taken along line BB' in Figure 7.
Figure 10 is a diagram showing the length of the bottom of the lens and the length of the bottom of the receiving groove in the display device according to one embodiment.
FIG. 11 shows the light source shown in FIG. 7 with the lens separated from the light emitting diode and the refractive cover.
FIG. 12 is a diagram illustrating a lens separately in a display device according to an embodiment.
Figure 13 shows an example of the structure of a display device according to an embodiment.

The embodiments described in this specification and the configurations shown in the drawings are only preferred examples of the disclosed invention, and at the time of filing this application, there may be various modifications that can replace the embodiments and drawings in this specification.

In addition, the same reference numbers or symbols shown in each drawing of this specification indicate parts or components that perform substantially the same function.

Additionally, the terms used herein are used to describe embodiments and are not intended to limit and/or limit the disclosed invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this specification, terms such as “comprise” or “have” are intended to indicate the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, but are not intended to indicate the presence of one or more other features. The existence or addition of numbers, steps, operations, components, parts, or combinations thereof is not excluded in advance.

In addition, terms including ordinal numbers such as “first”, “second”, etc. used in this specification may be used to describe various components, but the components are not limited by the terms, and the terms It is used only for the purpose of distinguishing one component from another. For example, a first component may be named a second component, and similarly, the second component may also be named a first component without departing from the scope of the present invention. The term “and/or” includes any combination of a plurality of related stated items or any of a plurality of related stated items.

Meanwhile, the terms “front”, “rear”, “left”, “right”, “up” and “rear” used in the following description are defined based on the drawings, and the shapes of each component are defined by these terms. and location is not limited.

A display device may include a liquid crystal panel and a backlight unit configured to provide light to the liquid crystal panel. The backlight unit includes a substrate extending in a first direction, a light emitting diode mounted on the substrate, a refractive cover covering the light emitting diode to refract light emitted from the light emitting diode, and a refractive cover to cover the refractive cover. The lens coupled to the substrate may include a lens whose bottom length in a second direction perpendicular to the first direction is longer than the bottom length in the first direction.

The lens may include an accommodating groove forming an accommodating space accommodating the refractive cover.

The refractive cover may be provided to be spaced apart from the lens within the accommodation space.

The length of the bottom of the receiving groove in the first direction may be longer than the length in the second direction.

The lens may be an anisotropic lens configured to emit more light incident on the lens in the second direction than in the first direction.

The light emitting diode may include a plurality of light emitting diodes arranged to be spaced apart at a first interval along the first direction.

The substrate may include a plurality of substrates arranged to be spaced apart at a second interval along the second direction.

The refractive cover may include a plurality of refractive covers covering each of the plurality of light emitting diodes.

The lens may include a plurality of lenses covering each of the plurality of refractive covers.

The backlight unit may be configured to satisfy d2 > 1.5 * d1 when the first interval is d1 and the second interval is d2.

The lens may include a package lens formed by connecting two or more lenses to cover two or more refractive covers as a unit.

The display device may further include a reflective sheet provided between the liquid crystal panel and the backlight unit and covering the plurality of substrates.

The reflective sheet may have a plurality of holes formed in the reflective sheet so that the plurality of lenses pass through each.

The display device may further include a plurality of reflective sheets provided between the liquid crystal panel and the backlight unit and respectively provided to correspond to the plurality of substrates.

The plurality of reflective sheets may have a plurality of holes formed in each of the plurality of reflective sheets so that the plurality of lenses pass through each.

The refractive cover may be formed by dispensing and curing a transparent material in a liquid state.

The light emitting diode may be mounted on the substrate using a chip on board (COB) method.

The light emitting diode may be configured to emit blue light.

A display device may include a liquid crystal panel and a backlight unit configured to provide light to the liquid crystal panel. The backlight unit includes a plurality of substrates each extending along a first direction, a plurality of substrates spaced apart from each other at a first interval along a second direction perpendicular to the first direction, and each of the plurality of substrates. A plurality of light emitting diodes mounted, the plurality of light emitting diodes being spaced apart from each other along the first direction at a second interval smaller than the first interval, and the plurality of light emitting diodes configured to refract light emitted from each of the plurality of light emitting diodes. A plurality of refractive covers covering each of the light emitting diodes and a plurality of lenses provided to cover each of the plurality of refractive covers, wherein a bottom length in the second direction is longer than a bottom length in the first direction. may include a lens.

The backlight unit may be configured to satisfy d1 > 1.5 * d2 when the first interval is d1 and the second interval is d2.

Each of the plurality of lenses may include an accommodating groove forming an accommodating space for accommodating each of the plurality of refractive covers.

Each of the plurality of refractive covers may be provided to be spaced apart from each of the plurality of lenses within the accommodation space.

The length of the bottom of the receiving groove in the first direction may be longer than the length in the second direction.

The plurality of lenses may be anisotropic lenses configured to emit more light incident on the plurality of lenses in the second direction than in the first direction.

Hereinafter, embodiments according to the present invention will be described in detail with reference to the attached drawings.

Figure 1 shows an example of the appearance of a display device according to an embodiment.

Referring to FIG. 1, the display device 10 is a device that processes image signals received from the outside and visually displays the processed image. Below, the case where the display device 10 is a television (TV) is exemplified, but is not limited thereto. For example, the display device 10 can be implemented in various forms such as a monitor, a portable multimedia device, and a portable communication device, and the form of the display device 10 is not limited as long as it is a device that visually displays images. .

In addition, the display device 10 may be a large format display (LFD) installed outdoors, such as on the roof of a building or at a bus stop. Here, the outdoors is not necessarily limited to the outdoors, and may include places where many people can come and go even indoors, such as subway stations, shopping malls, movie theaters, companies, and stores.

The display device 10 may receive content including video signals and audio signals from various content sources, and output video and audio corresponding to the video signals and audio signals. For example, the display device 10 may receive content data through a broadcast reception antenna or a wired cable, receive content data from a content playback device, or receive content data from a content provision server of a content provider.

As shown in FIG. 1, the display device 10 may include a main body 11 and a screen 12 that displays an image I.

The main body 11 forms the exterior of the display device 10, and parts for the display device 10 to display an image I or perform various functions may be provided inside the main body 11. The main body 11 shown in FIG. 1 has a flat plate shape, but the shape of the main body 11 is not limited to that shown in FIG. 1. For example, the main body 11 may have a curved plate shape.

The screen 12 is formed on the front of the main body 11 and can display an image (I). For example, screen 12 can display still images or moving images. Additionally, the screen 12 can display a two-dimensional flat image or a three-dimensional stereoscopic image using the parallax between the user's two eyes.

The screen 12 may include a non-emissive panel (eg, a liquid crystal panel) that can pass or block light emitted by a back light unit (BLU).

A plurality of pixels P are formed on the screen 12, and the image I displayed on the screen 12 may be formed by light emitted from each of the plurality of pixels P. For example, the image I may be formed on the screen 12 by combining the light emitted from each of the plurality of pixels P like a mosaic.

Each of the plurality of pixels P may emit light of various brightnesses and colors. In order to emit light of various colors, each of the plurality of pixels P may include subpixels PR, PG, and PB.

The subpixels (PR, PG, PB) include a red subpixel (PR) capable of emitting red light, a green subpixel (PG) capable of emitting green light, and a blue subpixel capable of emitting blue light. It may include a pixel (PB). For example, red light can represent light with a wavelength of approximately 620 nm (nanometer, one billionth of a meter) to 750 nm. Green light can represent light with a wavelength ranging from approximately 495 nm to 570 nm. Blue light can represent light with a wavelength ranging from approximately 450 nm to 495 nm.

By combining the red light of the red subpixel (PR), the green light of the green subpixel (PG), and the blue light of the blue subpixel (PB), light of various brightnesses and colors is emitted from each of the plurality of pixels (P). can do.

FIG. 2 shows an example of the structure of the display device 10 according to an embodiment, and FIG. 3 shows an example of a liquid crystal panel included in the display device 10 according to an embodiment.

The display device 10 includes a backlight unit (BLU) 100, a liquid crystal panel 20 that blocks or passes light emitted from the backlight unit 100, and the liquid crystal panel 20 and the backlight unit. It may include a chassis assembly supporting (100). The display device 10 includes an optical member 60 provided between the liquid crystal panel 20 and the backlight unit 100, and a reflective sheet 90 provided between the optical member 60 and the backlight unit 100. can do.

The chassis assembly includes a rear chassis 50 provided to support the backlight unit 100, a front chassis 30 provided in front of the rear chassis 50 to support the liquid crystal panel 20, and a front chassis 30. It may include a middle mold 40 coupled between and the rear chassis 50. The chassis assembly can accommodate the liquid crystal panel 20 and the backlight unit 100 therein.

The liquid crystal panel 20 is provided in front of the backlight unit 100 and blocks or passes light emitted from the backlight unit 100 to form an image I.

According to one embodiment, the reflective sheet 90 may have a plurality of light sources 120 and a plurality of holes 91 respectively corresponding to each other. The reflective sheet 90 may be provided in a plate shape corresponding to the size of the liquid crystal panel 20. The plurality of holes 91 may be formed inside the reflective sheet 90 and may have a diameter larger than the outer diameter of the light source 120 to allow the light source 120 to pass through.

The reflective sheet 90 may be provided in front of the substrate 110 so that each of the plurality of light sources 120 mounted on the substrate 110 passes through each of the plurality of holes 91. The reflective sheet 90 may reflect light emitted, reflected, or refracted toward the reflective sheet 90 forward.

The front surface of the liquid crystal panel 20 forms the screen 12 of the display device 10 described above, and the liquid crystal panel 20 can form a plurality of pixels P. In the liquid crystal panel 20, the plurality of pixels P may independently block or pass light from the backlight unit 100. Additionally, light passing through the plurality of pixels (P) may form an image (I) displayed on the screen (12).

For example, as shown in FIG. 3, the liquid crystal panel 20 includes a first polarizing film 21, a first transparent substrate 22, a pixel electrode 23, a thin film transistor 24, and a liquid crystal layer 25. , it may include a common electrode 26, a color filter 27, a second transparent substrate 28, and a second polarizing film 29.

The first transparent substrate 22 and the second transparent substrate 28 can fix and support the pixel electrode 23, thin film transistor 24, liquid crystal layer 25, common electrode 26, and color filter 27. there is. These first and second transparent substrates 22 and 28 may be made of tempered glass or transparent resin.

The first polarizing film 21 and the second polarizing film 29 are provided outside the first and second transparent substrates 22 and 28. The first polarizing film 21 and the second polarizing film 29 can each pass certain polarized light and block (reflect or absorb) other polarized light. For example, the first polarizing film 21 may pass polarized light in the first direction and block (reflect or absorb) other polarized light. Additionally, the second polarizing film 29 may pass polarized light in the second direction and block (reflect or absorb) other polarized light. At this time, the first direction and the second direction may be perpendicular to each other. Therefore, the polarized light that has passed through the first polarizing film 21 cannot directly pass through the second polarizing film 29.

The color filter 27 may be provided inside the second transparent substrate 28. The color filter 27 may include, for example, a red filter 27R that passes red light, a green filter 27G that passes green light, and a blue filter 27G that passes blue light. Additionally, the red filter 27R, green filter 27G, and blue filter 27B may be arranged in parallel with each other. The area occupied by the color filter 27 corresponds to the pixel P described above. The area occupied by the red filter 27R corresponds to the red subpixel PR, the area occupied by the green filter 27G corresponds to the green subpixel PG, and the area occupied by the blue filter 27B corresponds to the green subpixel PG. Corresponds to the blue subpixel (PB).

The pixel electrode 23 may be provided inside the first transparent substrate 22, and the common electrode 26 may be provided inside the second transparent substrate 28. The pixel electrode 23 and the common electrode 26 are made of a metal material that conducts electricity, and can generate an electric field to change the arrangement of the liquid crystal molecules 115a constituting the liquid crystal layer 25, which will be described below. there is.

A thin film transistor (TFT) 24 is provided inside the second transparent substrate 22. The thin film transistor 24 may be turned on (closed) or turned off (open) by image data provided from the panel driver 30. Additionally, an electric field may be created or removed between the pixel electrode 23 and the common electrode 26 depending on whether the thin film transistor 24 is turned on (closed) or turned off (open).

The liquid crystal layer 25 is formed between the pixel electrode 23 and the common electrode 26 and is filled with liquid crystal molecules 25a. Liquid crystals can represent an intermediate state between a solid (crystal) and a liquid. Liquid crystals can exhibit optical properties depending on changes in the electric field. For example, in liquid crystals, the direction of the molecular arrangement that makes up the liquid crystal may change depending on changes in the electric field. Therefore, the optical properties of the liquid crystal layer 25 may vary depending on the presence or absence of an electric field passing through the liquid crystal layer 25. For example, the liquid crystal layer 25 may rotate the polarization direction of light around the optical axis depending on the presence or absence of an electric field. As a result, the polarization direction of the polarized light passing through the first polarizing film 21 is rotated while passing through the liquid crystal layer 25, and can pass through the second polarizing film 29.

Figure 4 shows an example of an optical sheet and a diffusion plate in a display device according to an embodiment.

Referring to FIG. 4 , the display device 10 may include an optical member 60 provided between the liquid crystal panel 20 and the backlight unit 100.

The optical member 60 includes a diffusion plate 70 provided to uniformly diffuse the light emitted from the backlight unit 100, and an optical element provided in front of the diffusion plate 70 to improve the luminance of the emitted light. It may include a sheet 80.

The diffusion plate 70 may be provided in front of the backlight unit 100. The diffusion plate 70 can evenly disperse the light emitted from the light source 120 of the backlight unit 100.

The diffusion plate 70 may diffuse light emitted from the plurality of light sources 120 within the diffusion plate 70 in order to reduce unevenness of luminance caused by the plurality of light sources 120 . In other words, the diffusion plate 13070 can diffuse the uneven light emitted from the plurality of light sources 120 and emit it relatively uniformly to the entire surface.

The optical sheet 80 may include various sheets to improve luminance and uniformity of luminance. For example, the optical sheet 80 may include a light conversion sheet 81, a diffusion sheet 82, a prism sheet 83, a reflective polarizing sheet 84, etc.

The optical sheet 80 is not limited to the sheet or film shown in FIG. 4 and may include more various sheets or films, such as a protective sheet.

FIG. 5 is a diagram illustrating a backlight unit in a display device according to an embodiment. Figure 6 is an enlarged view of A in Figure 5.

With reference to FIGS. 5 and 6 , the arrangement of the plurality of substrates 110 and the plurality of light sources 120 in the backlight unit 100 according to one embodiment will be described. Hereinafter, the X direction shown in FIGS. 5 and 6 may point to a first direction, and the Y direction may point to a second direction.

The backlight unit 100 may include a substrate 110 extending along a first direction (X) and a plurality of light sources 120 spaced apart from each other along the first direction on the substrate 110. The backlight unit 100 may include a plurality of substrates 110 spaced apart from each other along a second direction (Y) perpendicular to the first direction. Hereinafter, the substrate 110 extending along one direction is referred to as a bar type substrate.

Referring to FIG. 6, in the first substrate 111 and the second substrate 112 that are adjacent to each other among the plurality of substrates 110, the two light sources 121 and 122 adjacent in the first direction (X) are separated by a first gap ( It can be spaced apart by d1). The plurality of light sources 120 includes a first light source 121 and a second light source 122 mounted on the first substrate 111, a third light source 123 and a second light source 122 mounted on the second substrate 112. It may include 4 light sources (124). The first light source 121 and the third light source 123 corresponding in the second direction (Y) may be spaced apart by a second distance (d2). Likewise, the second light source 122 and the fourth light source 124 may be spaced apart by a second distance d2.

The first light source 121 and the second light source 122 mounted in the first substrate 111 may be spaced apart by a first distance d1 in the first direction (X). The third light source 123 and the fourth light source 124 mounted in the second substrate 112 may be spaced apart by a first distance d1 in the first direction (X).

As described above, the backlight unit 100 according to one embodiment includes a plurality of substrates 110 spaced apart by a second distance d2 in the second direction (Y), and a first substrate 110 in the first direction (X). It may include a plurality of light sources 120 spaced apart by a distance d1. The backlight unit 100 may be prepared such that the first interval d1 and the second interval d2 satisfy d2 > 1.5 * d1. In other words, the second gap d2 between the two adjacent substrates 111 and 112 can be set to be greater than 1.5 times the first gap d1 between the two adjacent light sources 121 and 122 or 123 and 124. there is.

In general, a backlight unit including a plurality of bar type substrates and a plurality of light sources mounted on the plurality of bar type substrates has a relatively small number of light sources, so there is only one light source corresponding to the size of the liquid crystal panel. It is advantageous in terms of manufacturing cost compared to a backlight unit that includes a substrate and a plurality of light sources mounted on the substrate.

In order to reduce the manufacturing cost of a backlight unit including a bar-type substrate, it is necessary to increase the gap between the substrates. The gap between the substrates may be larger than the gap between light sources mounted within the substrate.

However, if the gap between the substrates is larger than the gap between light sources within the substrate, the luminance uniformity of the backlight unit may deteriorate. Since the gap between two adjacent substrates is larger than the gap between two adjacent light sources within the substrate, there is a lack of luminance between the two substrates, and dark mura may occur between the two substrates.

FIG. 7 is a diagram illustrating a substrate, a light emitting diode, a refractive cover, and a lens in a display device according to an embodiment. FIG. 8 shows an example of a cross section of a light emitting diode along line B-B' in FIG. 7. Figure 9 is a cross-sectional view taken along line BB' in Figure 7. Figure 10 is a diagram showing the length of the bottom of the lens and the length of the bottom of the receiving groove in the display device according to one embodiment. FIG. 11 shows the light source shown in FIG. 7 with the lens separated from the light emitting diode and the refractive cover.

Referring to FIG. 7 , the backlight unit 100 may include a bar-type substrate 110 and a light source 120 provided on the substrate 110. The light source 120 may include a light emitting diode 130 mounted on the substrate 110, a refractive cover 140 that covers the light emitting diode 130, and a lens 150 that covers the refractive cover 140. there is.

The light emitting diode 130 may be mounted directly on the substrate 110. Specifically, the light emitting diode 130 can be directly mounted on the substrate 110 using a COB (Chip On Board) method without a separate package. The light emitting diode 130 may be configured to emit blue light.

Referring to FIG. 8 , the light emitting diode 130 may include a transparent substrate 135, an n-type semiconductor layer 133, and a p-type semiconductor layer 132. Additionally, a multi quantum well (MQW) layer 134 is formed between the n-type semiconductor layer 133 and the p-type semiconductor layer 132.

The transparent substrate 135 may be the base of a pn junction capable of emitting light. The transparent substrate 135 may include, for example, sapphire (Al ₂ O ₃ ), which has a crystal structure similar to that of the semiconductor layers 133 and 132.

By bonding the n-type semiconductor layer 133 and the p-type semiconductor layer 132, a pn junction can be implemented. A depletion region may be formed between the n-type semiconductor layer 133 and the p-type semiconductor layer 132. In the depletion layer, electrons of the n-type semiconductor layer 133 and holes of the p-type semiconductor layer 132 may recombine. Light can be emitted by recombination of electrons and holes.

The n-type semiconductor layer 133 may include, for example, n-type gallium nitride (n-type GaN). Additionally, the p-type semiconductor layer 132 may also include, for example, p-type gallium nitride (p-type GaN). The energy band gap of gallium nitride (GaN) is approximately 3.4 eV (electronvolt), which can emit light with a wavelength shorter than 400 nm. Accordingly, deep blue or ultraviolet rays may be emitted from the junction of the n-type semiconductor layer 133 and the p-type semiconductor layer 132.

The n-type semiconductor layer 133 and the p-type semiconductor layer 132 are not limited to gallium nitride, and various semiconductor materials may be used depending on the light required.

The first electrode 131a of the light emitting diode 130 is in electrical contact with the p-type semiconductor layer 132, and the second electrode 131b is in electrical contact with the n-type semiconductor layer 133. The first electrode 131a and the second electrode 131b may function not only as electrodes but also as reflectors that reflect light.

When voltage is applied to the light emitting diode 130, holes are supplied to the p-type semiconductor layer 132 through the first electrode 131a, and electrons are supplied to the n-type semiconductor layer 133 through the second electrode 131b. can be supplied. Electrons and holes can recombine in the depletion layer formed between the p-type semiconductor layer 132 and the n-type semiconductor layer 133. At this time, while the electrons and holes are recombining, the energy of the electrons and holes (eg, kinetic energy and potential energy) may be converted into light energy. In other words, when electrons and holes recombine, light can be emitted.

At this time, the energy gap (energy band gap) of the quantum well layer 134 is smaller than the energy gap of the p-type semiconductor layer 132 and/or the n-type semiconductor layer 133. As a result, holes and electrons can each be trapped in the quantum well layer 134.

Holes and electrons trapped in the quantum well layer 134 can easily recombine with each other in the quantum well layer 134. As a result, the light generation efficiency of the light emitting diode 130 can be improved.

From the quantum well layer 134, light having a wavelength corresponding to the energy gap of the quantum well layer 134 may be emitted. For example, quantum well layer 134 may emit blue light between 420 nm and 480 nm. As such, the quantum well layer 134 may correspond to a light emitting layer that emits blue light.

A first reflective layer 136 is provided on the outside of the transparent substrate 135 (top of the transparent substrate in the drawing). That is, the first reflective layer 136 may be disposed on top of the light emitting layer 134. Additionally, a second reflection layer 137 is provided outside the p-type semiconductor layer 132 (lower part of the p-type semiconductor layer in the drawing). In this way, the transparent substrate 135, the n-type semiconductor layer 133, the quantum well layer 134, and the p-type semiconductor layer 132 will be disposed between the first reflection layer 136 and the second reflection layer 137. You can.

The first reflection layer 136 and the second reflection layer 137 may each reflect a portion of the incident light and allow another portion of the incident light to pass through.

For example, the first reflection layer 136 and the second reflection layer 137 may reflect light having a wavelength within a specific wavelength range and may pass light having a wavelength outside the specific wavelength range. For example, the first reflection layer 136 and the second reflection layer 137 may reflect blue light having a wavelength between 420 nm and 480 nm emitted from the quantum well layer 134.

Additionally, the first reflection layer 136 and the second reflection layer 137 may reflect incident light having a specific incident angle and may pass light outside the specific incident angle. As such, the first reflection layer 136 and the second reflection layer 137 may be DBR (Distributed Bragg Reflector) layers formed by stacking materials with different refractive indices so as to have various reflectances depending on the angle of incidence.

For example, the first reflection layer 136 may reflect light incident at a small incident angle and pass light incident at a large incident angle. Additionally, the second reflection layer 137 may reflect or pass light incident at a small incident angle and reflect light incident at a large incident angle. Here, the incident light may be blue light with a wavelength between 420 nm and 480 nm.

Referring to FIGS. 7 and 9 , the backlight unit 100 may include a refractive cover 140 that covers the light emitting diode 130 to refract light emitted from the light emitting diode 130.

The refractive cover 140 may be formed by dispensing a transparent material in a liquid state onto the light emitting diode 130 and then hardening it. The transparent material may include silicon. The refractive cover 140 may be formed by dispensing and curing the liquid transparent material at one point or multiple points on the light emitting diode 130. The refractive cover 140 may refract light emitted from the light emitting diode 130. The refractive cover 140 may be provided to surround the light emitting diode 130. In other words, the refractive cover 140 can be referred to as a silicone dome.

Referring to FIGS. 7 and 9 , the backlight unit 100 may include a lens 150 provided to cover the refractive cover 140 .

The lens 150 may be coupled to the substrate 110 to cover the refractive cover 140. Lens 150 may be coupled to substrate 110 in various ways. For example, the lens 150 may be fixed to the substrate 110 by an adhesive.

The lens 150 may include an accommodating groove 152 that is recessed upward from its bottom 153, and an accommodating space 151 formed inside the accommodating groove 152.

Referring to FIG. 10, the lens 150 may be configured such that the length L2 of its bottom 153 in the second direction (Y) is greater than the length L1 in the first direction (X). The lens 150 may be configured such that the length L3 of the bottom of the receiving groove 152 in the first direction (X) is greater than the length L4 in the second direction (Y).

The lens 150 can accommodate the refractive cover 140 inside the receiving space 151 formed by the receiving groove 152. The receiving space 151 may be provided larger than the volume of the refractive cover 140. Accordingly, within the accommodation space 151, the refractive cover 140 may be spaced apart from the lens 150.

The lens 150 may be configured to emit light incident from the light emitting diode 130 through the refractive cover 140 into the receiving groove 152 toward the front. More specifically, the lens 150 may be configured to emit more light incident on the receiving groove 152 in the second direction (Y) than in the first direction (X). The lens 150 may be an anisotropic lens configured so that the amount of light emitted in the second direction is greater than the amount of light emitted in the first direction.

Since the lens 150 is configured to emit more light in the second direction than in the first direction, the light source 120 may emit more light in the second direction than in the first direction. As described above, the second gap d2 between the two light sources 121, 123 or 122, 124 corresponding to each other in the two adjacent substrates 111 and 112 is the distance between the two adjacent light sources in one substrate 111 or 112. It may be provided to be at least 1.5 times larger than the first interval d1 between (121, 122 or 123, 124). Since the second gap d2 is provided larger than the first gap d1, dark mura may occur between the two substrates due to insufficient light.

According to one embodiment, dark mura can be removed or reduced by including a light source 120 configured to emit more light toward a space between a substrate and a substrate with insufficient light amount. That is, the luminance uniformity of the backlight unit 100 can be improved.

FIG. 12 is a diagram illustrating a lens separately in a display device according to an embodiment.

Referring to FIG. 12, the backlight unit 100 according to one embodiment may include a package lens 250 formed by connecting a plurality of lenses.

The package lens 250 may cover two or more refractive covers 140 as one unit. The package lens 250 may be formed by connecting two or more lenses to cover the two or more refractive covers 140 as one unit. For example, four lenses 251, 252, 253, and 254 may be connected to each other to form a package lens 250. In the package lens 250, the bottom surfaces of a plurality of lenses may be connected to each other. Since the package lens 250 has a plurality of lenses connected to each other, light can move within it. Due to these characteristics, the package lens 250 may be referred to as a tunnel-type lens.

According to one embodiment, the package lens 250 may include a first lens 251, a second lens 252, a third lens 253, and a fourth lens 254. Each lens 251, 252, 253, and 254 may have accommodation spaces 251a, 252a, 253a, and 254a therein. Additionally, the package lens 250 may include a connecting portion 260 that connects the bottom surfaces of each lens 251, 252, 253, and 254 to each other.

The package lens 250 is advantageous in terms of productivity because it can cover a plurality of refractive covers 140 in a single process. The package lens 250 may be coupled to the substrate 110 by coupling the connection portion 260 to the substrate 110. For example, the package lens 250 may be coupled to the substrate 110 by attaching the connection portion 260 to the substrate 110 with an adhesive.

Each of the plurality of lenses 251, 252, 253, and 254 included in the package lens 251 may have the same structure as the lens 150 described above. That is, the bottom surface of each of the plurality of lenses 251, 252, 253, and 254 may be provided with a length in the second direction (Y) that is longer than the length in the first direction (X). Additionally, the bottom of each receiving groove of the plurality of lenses 251, 252, 253, and 254 may be provided with a length in the first direction (X) longer than a length in the second direction (Y).

Figure 13 shows an example of the structure of a display device according to an embodiment.

The display device 10 according to one embodiment may include a plurality of reflective sheets 90a.

Referring to FIG. 13, the display device 10 may include a plurality of substrates 110 and a plurality of reflective sheets 90a, each corresponding to a plurality of substrates 110. The reflective sheet 90a may extend along the direction in which the substrate 110 extends. The reflective sheet 90a may extend along a first direction (X, see FIG. 5). The reflective sheet 90a may be provided in a shape corresponding to the substrate 110 to cover the substrate 110.

The reflective sheet 90a may have a plurality of holes 91a. Each of the plurality of holes 91a may have a diameter larger than the outer diameter of the light source 120 to allow the light source 120 to pass through. Specifically, each of the plurality of holes 91a may have a diameter larger than the outer diameter of the lens 150 so that the lens 150 can pass through each of the plurality of holes 91a.

The reflective sheet 90a may be provided in front of the substrate 110 so that each of the plurality of light sources 120 mounted on the substrate 110 passes through each of the plurality of holes 91a. The reflective sheet 90a may reflect light emitted, reflected, or refracted toward the reflective sheet 90a forward.

In the above, specific embodiments are shown and described. However, it is not limited to the above-described embodiments, and those skilled in the art can make various changes without departing from the gist of the technical idea of the invention as set forth in the claims below. .

10: display device
20: liquid crystal panel
60: Optical member
90: reflective sheet
100: backlight unit
110: substrate
120: light source
130: light emitting diode
140: refraction cover
150: Lens
250: package lens

Claims (20)

liquid crystal panel; and
a backlight unit configured to provide light to the liquid crystal panel; Including,
The backlight unit is,
a substrate extending along a first direction;
A light emitting diode mounted on the board,
A refractive cover covering the light emitting diode to refract the light emitted from the light emitting diode, and
A display device comprising a lens coupled to the substrate to cover the refractive cover, the lens having a bottom length in a second direction perpendicular to the first direction longer than a bottom length in the first direction. According to paragraph 1,
The lens is a display device including an accommodating groove forming an accommodating space accommodating the refractive cover. According to paragraph 2,
The refractive cover is provided to be spaced apart from the lens within the accommodation space. According to paragraph 2,
A display device wherein a bottom of the receiving groove has a length in the first direction longer than a length in the second direction. According to paragraph 1,
The lens is an anisotropic lens configured to emit more light incident on the lens in the second direction than in the first direction. According to paragraph 1,
The light emitting diode includes a plurality of light emitting diodes arranged to be spaced apart at a first interval along the first direction,
A display device wherein the substrate includes a plurality of substrates spaced apart from each other at a second interval along the second direction. According to clause 6,
The refractive cover includes a plurality of refractive covers covering each of the plurality of light emitting diodes,
A display device wherein the lens includes a plurality of lenses covering each of the plurality of refractive covers. According to clause 6,
The backlight unit is configured to satisfy d2 > 1.5 * d1 when the first interval is d1 and the second interval is d2. According to clause 6,
The lens is a display device including a package lens formed by connecting two or more lenses to cover two or more refractive covers as a unit. In clause 7,
a reflective sheet provided between the liquid crystal panel and the backlight unit and covering the plurality of substrates; It further includes,
The reflective sheet is a display device having a plurality of holes formed in the reflective sheet so that the plurality of lenses pass through each. In clause 7,
a plurality of reflective sheets provided between the liquid crystal panel and the backlight unit and respectively corresponding to the plurality of substrates; It further includes,
A display device wherein the plurality of reflective sheets have a plurality of holes formed in each of the plurality of reflective sheets so that the plurality of lenses pass through each. According to paragraph 1,
The refractive cover is a display device formed by dispensing and curing a transparent material in a liquid state. According to paragraph 1,
A display device in which the light emitting diode is mounted on the substrate using a chip on board (COB) method. According to paragraph 1,
The light emitting diode is a display device configured to emit blue light. liquid crystal panel; and
a backlight unit configured to provide light to the liquid crystal panel; Including,
The backlight unit is,
a plurality of substrates each extending along a first direction, the plurality of substrates being spaced apart at a first interval along a second direction perpendicular to the first direction;
A plurality of light emitting diodes mounted on each of the plurality of substrates, the plurality of light emitting diodes being spaced apart from each other at a second interval smaller than the first interval along the first direction;
A plurality of refractive covers covering each of the plurality of light emitting diodes to refract the light emitted from each of the plurality of light emitting diodes, and
A display device comprising a plurality of lenses provided to cover each of the plurality of refractive covers, wherein a bottom length in the second direction is longer than a bottom length in the first direction. According to clause 15,
The backlight unit is configured to satisfy d1 > 1.5 * d2 when the first interval is d1 and the second interval is d2. According to clause 15,
Each of the plurality of lenses includes a receiving groove that forms an accommodating space for accommodating each of the plurality of refractive covers. According to clause 17,
Each of the plurality of refractive covers is provided to be spaced apart from each of the plurality of lenses within the accommodation space. According to clause 17,
A display device wherein a bottom of the receiving groove has a length in the first direction longer than a length in the second direction. According to clause 15,
The plurality of lenses are anisotropic lenses configured to emit more light incident on the plurality of lenses in the second direction than in the first direction.

Images