WO2022244980A1 - Backlight unit, display device, and method of manufacturing same - Google Patents

Abstract

A backlight unit according to an embodiment of the present disclosure comprises: a substrate; a light source which is disposed at one surface of the substrate to radiate light; and an optical guide which is a three-dimensional structure surrounding the light source and guides a part of light, radiated by the light source, in the lateral direction of the light source, wherein the optical guide comprises an upper surface having an opening through which light radiated by the light source passes and which is formed in a position corresponding to the light source; an inner surface which surrounds the light source and to which light radiated by the light source is transmitted; and an outer surface which receives light transmitted from the inner surface and emits same out of the optical guide.

Description

Backlight unit, display device and manufacturing method thereof

The present disclosure relates to a backlight unit, a display device, and a method for manufacturing the same, and more particularly, to a direct type backlight unit including an optical guide surrounding a light source, a display device including the same, and a method for manufacturing the same.

A display device is an output device that expresses various colors by operation in units of pixels or sub-pixels. As technology develops, research has been conducted to improve the image quality of the display device and to make it larger and slimmer.

Among display devices, a liquid crystal display (LCD) device has been using a back light unit (BLU) as a light source. It has been adopting a direct type rather than a direct type.

However, the direct type backlight unit has a problem in that mura, which is a stain due to a dark part, a bright part, color, etc., occurs in a portion adjacent to a light source, resulting in image quality deterioration. Accordingly, there was a structure including a support plate supporting the optical sheet between the backlight unit and the optical sheet, but the thickness of the display device became thick due to structural limitations, and the image quality of the display device was actively deteriorated. There were problems that could not be improved.

The present disclosure is based on technical needs for improving the above problems, and an object of the present disclosure is to provide a direct type backlight unit having an improved structure for preventing Mura phenomenon, improving image quality, and realizing slimming, a display device, and a display device therefor. It is to provide a manufacturing method.

A backlight unit according to an embodiment of the present disclosure for achieving the above object includes a substrate, the light source disposed on one surface of the substrate and emitting light, and a three-dimensional structure surrounding the light source, wherein the light source irradiates and the optical guide for guiding a portion of the light to the side of the light source, and the optical guide surrounds the light source and an upper surface formed at a position corresponding to the light source through which the light irradiated by the light source passes. and an inner surface for receiving the light emitted by the light source and an outer surface for receiving light from the inner surface and emitting the light to the outside of the optical guide.

In this case, a reflective member that reflects light inside the optical guide and blocks emission to the outside of the optical guide may be applied to at least a portion of the upper surface of the optical guide.

In this case, a portion of the light inside the optical guide may be emitted to the outside of the optical guide through a portion of the upper surface of the optical guide other than the portion where the reflective member is applied.

Meanwhile, the optical guide may include a lower surface opposite to the upper surface and coated with a reflective member for reflecting light inside the optical guide.

Meanwhile, an outer surface of the optical guide may be parallel to the inner surface.

Meanwhile, the inner surface of the optical guide may be inclined to be away from the light source as it is developed from top to bottom.

Meanwhile, the opening of the upper surface may have an area smaller than that of the upper surface of the light source.

Meanwhile, an upper surface of the optical guide may be formed to be flat, and the optical guide may have the same height as that of the light source.

Meanwhile, the optical guide has a height greater than that of the light source, and the inner surface faces a part of the upper surface and side surfaces of the light source to receive light emitted from the light source.

Meanwhile, the light source may include a diffusion molding that surrounds an outer circumferential surface of the light source and diffuses light, and the optical guide may be disposed to surround the light source and the diffusion molding.

Meanwhile, at least a partial area of the inner surface of the optical guide may include a diffusion area formed to be spaced apart from the light source.

In this case, a light diffusion material disposed in the diffusion region to diffuse light may be included.

In this case, the light diffusion material may be made of a material including at least one of silicon, optical resin, and solid phosphor.

Meanwhile, air may be filled in the diffusion region.

Meanwhile, a display device according to an embodiment of the present disclosure includes a substrate, a light source disposed on one surface of the substrate to emit light, and a three-dimensional structure surrounding the light source, and a part of the light emitted by the light source is transmitted to the light source. An optical guide for guiding in a lateral direction of the light source and an optical sheet disposed above the light source and made of a light-transmitting material that transmits light, wherein the optical guide has an opening through which light irradiated by the light source passes, corresponding to the light source. An upper surface formed at a position where the light source is irradiated, the inner surface surrounding the light source and receiving light irradiated by the light source, and an outer surface receiving light from the inner surface and emitting it to the outside of the optical guide, wherein the optical guide, At least a portion of the upper surface may contact the optical sheet.

Meanwhile, a method of manufacturing a display device according to an embodiment of the present disclosure includes preparing a substrate, arranging a light source on one surface of the substrate, surrounding the light source, and the top surface of the light source is open. arranging an optical guide for receiving a portion of the light emitted from the light source toward an inner surface and guiding the light toward an outer surface, and attaching an optical sheet made of a light-transmitting material to an upper portion of the optical guide. can include

In this case, in the disposing of the optical guide, the optical guide may be formed higher than the height of the light source.

Meanwhile, in the attaching of the optical sheet, at least a portion of an upper surface of the optical guide may be attached to the optical sheet.

Meanwhile, in the disposing of the optical guide, at least a portion of the inner surface of the optical guide may be disposed to be spaced apart from the light source.

In this case, in the disposing of the optical guide, a light diffusion material may be disposed in a space separated from the light source and the inner surface of the optical guide.

1 is a perspective view of a display device according to an embodiment of the present disclosure.

2 is an exploded perspective view of a display device according to an exemplary embodiment of the present disclosure.

3A is a plan view of a light source package according to an embodiment of the present disclosure.

FIG. 3B is a cross-sectional view of the light source package taken along 'B-B' shown in FIG. 3A.

FIG. 4 is a graph illustrating optical profiles of a straight upper portion and a side portion of a light source package according to an exemplary embodiment of the present disclosure.

FIG. 5 is a cross-sectional view of the display device taken along line 'A-A' in FIG. 1 .

6 is a cross-sectional view of a plurality of light source packages according to an embodiment of the present disclosure.

7 is a graph illustrating optical profiles of a plurality of light source packages according to an exemplary embodiment of the present disclosure in straight upper portions and side portions.

8 is a cross-sectional view of a light source package according to an embodiment of the present disclosure.

9 is a flowchart illustrating a method of manufacturing a display device according to an embodiment of the present disclosure.

Terms used in this specification will be briefly described, and the present disclosure will be described in detail. In describing the present disclosure, detailed descriptions of related known technologies may be omitted, and redundant descriptions of the same configuration will be omitted as much as possible.

The terms used in the embodiments of the present disclosure have been selected from general terms that are currently widely used as much as possible while considering the functions in the present disclosure, but they may vary according to the intention or precedent of a person skilled in the art, or the emergence of new technologies. . In addition, in a specific case, there is also a term arbitrarily selected by the applicant, and in this case, the meaning will be described in detail in the description of the disclosure. Therefore, terms used in the present disclosure should be defined based on the meaning of the term and the general content of the present disclosure, not simply the name of the term.

Embodiments of the present disclosure may apply various transformations and may have various embodiments, and specific embodiments are illustrated in the drawings and described in detail in the detailed description. However, this is not intended to limit the scope to specific embodiments, and should be understood to include all transformations, equivalents, and substitutes included in the spirit and scope of technology disclosed. In describing the embodiments, if it is determined that a detailed description of a related known technology may obscure the subject matter, the detailed description will be omitted.

Terms such as first and second may be used to describe various components, but the components should not be limited by the terms. The terms may only be used for the purpose of distinguishing one component from another. For example, a first element may be termed a second element, and similarly, a second element may be termed a first element, without departing from the scope of the present disclosure.

Singular expressions include plural expressions unless the context clearly dictates otherwise. In this application, terms such as “comprise” or “consist of” are intended to indicate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, but one or more other It should be understood that the presence or addition of features, numbers, steps, operations, components, parts, or combinations thereof is not precluded.

In the present disclosure, a “module” or “unit” performs at least one function or operation, and may be implemented in hardware or software or a combination of hardware and software. In addition, a plurality of "modules" or a plurality of "units" may be integrated into at least one module and implemented by at least one processor, except for "modules" or "units" that need to be implemented with specific hardware.

Hereinafter, with reference to the accompanying drawings, embodiments of the present disclosure will be described in detail so that those skilled in the art can easily carry out the present disclosure. However, the present disclosure may be implemented in many different forms and is not limited to the embodiments described herein. And in order to clearly describe the present disclosure in the drawings, parts irrelevant to the description are omitted, and similar reference numerals are attached to similar parts throughout the specification.

Furthermore, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings and contents described in the accompanying drawings, but the present disclosure is not limited or limited by the embodiments.

Hereinafter, with reference to FIGS. 1 to 9 , a display device and a manufacturing method thereof according to the present disclosure will be described in detail.

1 is a perspective view of a display device 1 according to an embodiment of the present disclosure, and FIG. 2 is an exploded perspective view of the display device according to an embodiment of the present disclosure.

1 and 2, the display device 1 according to an embodiment of the present disclosure may display an image through a screen 11, and includes a housing 50, a display panel 20, and a diffusion sheet 30. , an optical sheet 40 and a backlight unit 100 .

The display device 1 is a device capable of receiving and processing an image signal internally or externally and visually displaying the processed image through a screen 11, such as a television, a monitor, a portable multimedia device, a portable communication device, and the like. It can be implemented in a form, and the form is not limited as long as it is a device that visually displays an image.

The housing 50 may accommodate the display panel 20 , the diffusion sheet 30 , the optical sheet 40 , and the backlight unit 100 therein to form the appearance of the display device 1 . The housing 50 may include an opening on the front surface to form a screen 11 exposing the front surface of the display panel 20 displaying images to the outside.

The display panel 20 may forwardly display various images according to an image signal input from the outside, and may be composed of a liquid crystal display (LCD) panel. Also, since the display panel 20 does not independently emit light, light may be provided from the backlight unit 100 .

The display panel 20 may include a color filter substrate (not shown) having a color filter and a black matrix and a thin film transistor substrate (not shown) having a plurality of thin film transistors, between the color filter substrate and the thin film transistor substrate. A liquid crystal (not shown) may be filled in. Since the display panel 20 may use a liquid crystal panel according to a known technology, a detailed description thereof will be omitted.

The diffusion sheet 30 is formed in a substantially rectangular flat plate shape having a size corresponding to that of the display panel 20 and is formed of a transmissive material capable of transmitting light. For example, the diffusion sheet 30 may be formed of a transparent plastic such as polymethyl methacrylate (PMMA) or polycarbonate (PC).

The diffusion sheet 30 uniformly diffuses the light emitted from the backlight unit 100 and transmits the light to the optical sheet 40 and the display panel 20 to widen a viewing angle and reduce bright spots, bright lines, stains, and the like.

The optical sheet 40 is disposed between the display panel 20 and the diffusion sheet 30 to minimize wasted light by using light refraction and reflection, thereby increasing the brightness of light emitted through the diffusion sheet 30. can be improved and the light can be evenly distributed.

The optical sheet 40 is formed by sequentially stacking at least one of a prism sheet (not shown), a protective sheet (not shown), a double bright enhancement film (DBEF) (not shown), and a quantum dot sheet (not shown). can have a structure.

The prism sheet and the dual luminance enhancing film may increase luminance by refracting or condensing light diffused through the diffusion sheet 30, and the protective sheet may include the diffusion sheet, the prism sheet, the dual luminance enhancing film, and the inside of the display device 1. It is possible to protect the components disposed in the external impact or foreign substances.

The quantum dot sheet may include quantum dots (Quantun Dot, QD) capable of absorbing light of various wavelength bands and scattering light of a desired wavelength band. Quantum dots may be inorganic crystalline materials or microholes of several tens of nanometers (nm) or smaller.

For example, when the backlight unit 100 emits blue light, the wavelength of the light passing through the quantum dot sheet is variously changed according to the size of the quantum dot to express a high purity color, thereby creating an image implemented on the display panel 20. Color reproducibility can be improved.

The backlight unit 100 may include a substrate 110, a light source 120, and an optical guide 150, and a light emitting structure formed of the light source 120 and the optical guide 150 may be referred to as a light source assembly 130. can The backlight unit 100 may include a plurality of light source assemblies 130 spaced apart from each other.

The substrate 110 is shown in a rectangular plate shape, but is not limited thereto, and may be formed in a bar shape with a narrow width and a long length.

A plurality of light source assemblies 130 may be installed on the upper surface of the substrate 110 at regular intervals. In addition, a power cable (not shown) may be formed on the substrate 110 to supply power to the plurality of light sources 120 and control driving.

A reflective member may be coated on the top surface of the substrate 110, and may be disposed on the remaining area of the top surface of the substrate 110 where the light source 120, the light source assembly 130, or the light source package 125 is not installed. Therefore, the reflective member may cover most of the upper surface of the substrate 110, except for a portion where the plurality of light sources 120, the light source assembly 130, or the light source package 125 are installed. For example, the reflective member may be attached to the substrate 110 to surround the optical guide 150 .

The light source assembly 130 includes a light source 120 and an optical guide 150 and may radiate light toward the upper side of the substrate 110 . The light source assembly 130 may be formed in plural and spaced apart from each other, and the backlight unit 100 may have a direct structure.

3A is a plan view of the light source assembly 130 according to an embodiment of the present disclosure, and FIG. 3B is a cross-sectional view of the light source assembly 130 taken along 'BB'' shown in FIG. 3A.

Referring to FIGS. 3A and 3B , the light source assembly 130 according to an embodiment of the present disclosure may include a light source 120 and an optical guide 150 .

The light source 120 may be disposed on the upper surface of the substrate 110 to emit light, and the plurality of light sources 120 may be spaced apart from each other at regular intervals. The light source 120 may include various types of light emitting elements, and for example, the light source 120 may include a light emitting diode (LED) chip and an encapsulant covering the LED chip. In this case, the encapsulant may be made of at least one of transparent epoxy and silicone, and may further include a reflective material such as TiO2 to prevent light generated from the LED chip from being absorbed or scattered in the encapsulant and disappearing.

Light emitted from the light source 120 may move to the display panel 20 via the diffusion sheet 30 and/or the optical sheet 40 . The light source 120 may be installed on the substrate 110 by surface mounting technology. Although not shown in the drawing, a reflective member may be applied to one surface of the substrate 110 on which the light source 120 is disposed, and the reflective member may be installed on a portion of the substrate 110 where the light source assembly 130 is not disposed. can Since the plurality of light sources 120 are the same as or similar to the conventional light emitting device, a detailed description thereof will be omitted.

The optical guide 150 is a three-dimensional structure surrounding the light source 120, and may guide and diffuse a portion of light emitted from the light source 120 in a lateral direction of the light source 120.

The optical guide 150 may be made of a transparent or translucent material to allow light to pass through, and may be made of a material to diffuse light in many directions. For example, the optical guide 150 may be made of silicon, glass, or a material containing a polymer-based PMMA, PC, or PMMA-PC polymer, or may have a laminated structure of PMMA, PC, or PMMA-PC. , but is not limited thereto and may be implemented with various light diffusion materials.

The optical guide 150 is a polyhedron structure, and surrounds the light source 120 and has an inner surface 153 facing the center of the optical guide 150 and an inner surface 153 facing the outer direction of the optical guide 150. It may include an outer surface 155 facing the . In addition, the optical guide 150 connects the inner surface 153 and the outer surface 155 and is in contact with the upper surface 151 facing the upper surface direction of the substrate 110 and one surface of the substrate 110, and the optical guide 150 It may include a lower surface 157 opposite to the upper surface 151 of the.

The optical guide 150 may guide and diffuse the light emitted from the light source 120 in a lateral direction of the light source 120 . In detail, as shown in FIG. 3B, the inner surface 153 of the optical guide 150 receives the light emitted from the light source 120, and the outer surface 155 of the optical guide 150 is the inner surface. Light may be received from 153 and emitted to the outside of the optical guide 150 . The upper surface 151 of the optical guide 150 includes an opening 152 formed at a position corresponding to the light source 120, through which the light emitted from the light source 120 upwards passes through the opening 152. can

The opening 152 of the upper surface 151 of the optical guide 150 may have an area smaller than that of the upper surface of the light source 120 . In this case, the opening 152 of the optical guide 150 may serve as a kind of optical slit, and the light emitted to the top of the light source 120 is emitted through the opening 152 of the upper surface 151 of the optical guide 150. It passes through and is diffracted, and can be diffused into a wider area.

Referring to FIG. 3B , a reflective member may be coated on an upper surface 151 of the optical guide 150 according to various embodiments. The surface on which the reflective member is coated may block light inside the optical guide 150 from being emitted to the outside, and may reflect light inside the optical guide 150 from the inside. Therefore, the light passing through the optical guide 150 spreads in all directions from the outer circumferential surface and can be diffused to an area adjacent to the light source 120 .

The reflective member may include at least one of PSR (Photo Solder Resist), polyester terephthalate (PET), polycarbonate (PC), and polyester to have high reflectivity, but is not limited thereto, and various members can be implemented as

In one embodiment, the reflective member may be applied to most of the upper surface 151 of the optical guide 150, or the reflective member may be applied to a limited area of the upper surface 151.

In an embodiment in which the reflective member is applied only to a partial area of the upper surface 151 of the optical guide 150, a portion of the light inside the optical guide 150 passes through the other partial area to which the reflective member is not applied. may be released to the outside. Therefore, the upper surface 151 of the optical guide 150 can freely adjust the area where the reflective member is applied, thereby adjusting the light emitting range and illuminance of the light source assembly 130, and the arrangement structure and arrangement structure of the light source assembly 130. Considering this, the application area of the reflective member of the upper surface 151 can be designed in various ways.

In the optical guide 150 of various embodiments, a reflective member may be applied to the lower surface 157, and the optical guide 150 transmits light to the inside of the optical guide 150 through the upper surface 151 and the lower surface 157. It can be guided in the direction of the outer surface 155 . In this case, the reflective member may also be applied to one surface of the substrate 110, and the reflective member may reflect a portion of light emitted from the light source assembly 130 upward.

In the optical guide 150, a reflective member is applied to at least a portion of the upper surface 151 and/or the lower surface 157 so that light is transferred from the inner surface 153 to the outer surface 155. ) The emission of light to the outside can be minimized, and the light diffusion efficiency of the light source assembly 130 can be improved.

Referring to the cross-sectional structure of the optical guide 150 of FIG. 3B, the cross-sections of the inner surface 153 and/or the outer surface 155 of the optical guide 150 may have a structure extending upward at a predetermined angle. .

For example, the inner surface 153 of the optical guide 150 may be inclined away from the light source 120 as it develops from top to bottom, and through this, light emitted in the lateral direction of the light source 120 It can be effectively transferred to the optical guide 150 . In addition, the height of the optical guide 150 may be higher than or equal to the light source 120, and the optical guide 150 may be formed according to the height of the optical guide 150 and the angle of the cross section of the inner surface 153. You can control the amount of light transmitted to it.

For example, in an embodiment in which the height of the optical guide 150 is greater than the height of the light source 120, a portion of the upper surface of the light source 120 is opposed to the opening 152 of the optical guide 150, and the light source ( 120) may emit some of the irradiated light to the opening 152 of the optical guide 150. In addition, another portion of the upper surface of the light source 120 and the side of the light source 120 face the inner surface 153 of the optical guide 150, and the light source 120 transmits a portion of the irradiated light to the optical guide 150. can be forwarded to

Therefore, the amount of light emitted through the opening 152 and the amount of light transmitted to the optical guide 150 depend on the angle and shape of the cross section of the inner surface 153 of the optical guide 150 and the height of the optical guide 150. can be adjusted.

The outer surface 155 of the optical guide 150 may be parallel to the inner surface 153 of the optical guide 150, depending on the angle and shape of the cross section of the outer surface 155 of the optical guide 150. The direction in which the light passing through 150 is emitted and the brightness of the light can be adjusted. When the inner side surface 153 and the outer side surface 155 are parallel, it may have an advantage in the manufacturing and installation process of the optical guide 150 .

An inner surface 153 of the optical guide 150 according to various embodiments may contact at least a portion of the light source 120 . In addition, the light source 120 and the optical guide 150 may be spaced apart or have a structure in which the optical guide 150 covers the entire side surface of the light source 120 .

When at least a portion of the inner surface 153 of the optical guide 150 is spaced apart from the light source 120, a diffusion area 123 may be formed in the spaced space. The diffusion region 123 is formed as an empty space and may be filled with air or an optical acid material. The diffusion region 123 filled with the light diffusion material 126 will be described in detail with reference to FIG. 8 .

That is, the optical guide 150 of various embodiments of the present disclosure is a polyhedral three-dimensional structure made of a material that diffuses and transmits light, and emits light emitted from the light source 120 according to the shape and cross-sectional structure of the optical guide 150 The position, direction of emission or amount of emission can be controlled.

FIG. 4 is a graph showing optical profiles at the top and side portions of the light source assembly 130 according to an embodiment of the present disclosure.

Referring to FIG. 4 , light distribution of the light source assembly 130 including the optical guide 150 may be predicted.

The central area C is a position where the opening 152 of the optical guide 150 is formed, and through the opening 152 of the optical guide 150, the light from the light source 120 toward the upper direction is diffracted and diffused over a wide area. It can be.

The outer area D is a position where the outer surface 155 of the optical guide 150 is formed, and among the light emitted from the light source 120, the light passing through the optical guide 150 is emitted from the outer area D. can

Therefore, referring to the optical profile of FIG. 4, the light source assembly 130 can transmit the light of the light source 120 to a relatively long distance through the optical guide 150, and the light source assembly 130 is the light source 120. The light can be spread evenly over a wide area efficiently.

In the display device 1 including the direct backlight unit 100, a dark portion is formed in an area where the light source 120 is located and an area adjacent to the light source 120, and mura, which is a stain due to a difference in luminance and color, is formed. ) can be formed.

However, since the light source assembly 130 including the optical guide 150 of the present disclosure can transmit and diffuse light to a location relatively far from the light source 120, the light is uniformly distributed to the rear surface of the diffusion sheet 30. It is possible to diffuse, prevent Mura phenomenon, and improve image quality.

In addition, in the display device 1 of the present disclosure, light of high illuminance is emitted not only in the central region C of the light source 120, but also in the external region D located between the light sources 120. For example, the interval between the light sources 120 can be widened, the total number of light sources 120 required by the backlight unit 100 can be reduced, and the total consumption of the display device 1 and the backlight unit 100 can be reduced. Power can be effectively improved.

FIG. 5 is a cross-sectional view of the display device 1 taken along line 'A-A' in FIG. 1 .

Referring to FIG. 5 , in the display device 1 , a display panel 20 , a diffusion sheet 30 , an optical sheet 40 , and a backlight unit 100 may be coupled through a housing 50 .

The housing 50 may include an upper housing 51 , an intermediate housing 52 , and a lower housing 53 .

The intermediate housing 52 may support the display panel 20 , the diffusion sheet 30 and/or the optical sheet 40 . The upper housing 51 may support the display panel 20 and the middle housing 52 so that the outer side of the display panel 20 remains supported by the middle housing 52 . The lower housing 53 accommodates the backlight unit 100 and may be coupled to the rear side of the middle housing 52 .

At the bottom of the lower housing 53, various printed circuit boards 55 that control the operation of the display device 1 are disposed, and the housing 50 includes a case 57 covering and covering the printed circuit board 55. can do.

The display panel 20 includes a first substrate 23 and a second substrate 24 on which electrodes are provided, and liquid crystal (not shown) is interposed between the first substrate 23 and the second substrate 24 facing each other. It may be made of a liquid crystal panel formed by encapsulating the liquid crystal. A printed circuit board 22 transmitting information to the display panel 20 may be disposed below the display panel 20 . In addition, a chip on film (COF, Chip On Film) electrically connecting the printed circuit board 22 and the display panel 20 may be disposed below the display panel 20 .

Between the display panel 20 and the backlight unit 100, a diffusion sheet 30 for uniformly diffusing light emitted from the backlight unit 100 and an optical sheet for improving characteristics of light supplied from the backlight unit 100 are provided. At least one or more of (40) may be disposed.

The cross-sectional structure of the display device 1 is not limited to the structure of FIG. 5 and may be implemented in various ways, and may be implemented the same as or similar to a conventional structure including the direct type backlight unit 100 .

The backlight unit 100 may radiate light toward the optical sheet 40 or the diffusion sheet 30 . Hereinafter, a structure in which the optical sheet 40 is disposed on the upper surface 151 of the backlight unit 100 will be described based on the structure, and in actual implementation, the diffusion sheet 30 may be included or the diffusion sheet 30 and the optical sheet 40 may be used. All may be included, and each arrangement structure may be implemented in various ways.

In various embodiments, the backlight unit 100 may include a plurality of light source packages 125 including diffusion molding that surrounds an outer circumferential surface of the light source 120 and diffuses light. The light source package 125 can evenly diffuse light emitted from the internal light source 120 through the molding structure, and can protect the light source 120 from external impact.

A distance d between the substrate 110 of the backlight unit 100 and the optical sheet 40 may be an optical depth. The optical distance (d) is a physical distance between the light source 120 and the optical sheet 40, and the display device 1 secures the optical distance (d) so that the light emitted from the light source 120 is wide in the horizontal direction. can be induced to spread. That is, when the optical distance d is short, the light emitted from the light source 120 directly proceeds to the optical sheet 40, but when the optical distance d is long, the light emitted from the light source 120 During step (d), it can be diffused and propagated to the optical sheet 40 , so that the display device 1 can minimize the Mura phenomenon caused by the direct backlight unit 100 .

The display device 1 without the optical guide 150 includes a supporter extending from the substrate 110 of the backlight unit 100 to the optical sheet 40 or the diffusion sheet 30 to secure an optical distance d. An optical distance d may be secured by including a support plate (not shown).

The optical guide 150 may be disposed to surround the light source 120 or the light source package 125 . Even at a relatively short optical distance d, light emitted through the light source package 125 can be widely diffused, and compared to an embodiment including a supporter plate (not shown), the thickness of the display device 1 is slim. can be implemented

At least a part of the upper surface 151 of the optical guide 150 may contact the optical sheet 40 , that is, the height of the optical guide 150 may be equal to the optical distance d. Therefore, the optical guide 150 can maximize horizontal diffusion of light until the light emitted from the light source 120 reaches the optical sheet 40 and effectively prevent the Mura phenomenon.

The optical guide 150 is in contact with the substrate 110 of the backlight unit 100 and the optical sheet 40 to fill the separation space 127, which is an empty space between the optical sheet 40 and the backlight unit 100, and An external shock applied to internal components of the display device 1 may be alleviated and supported so that the display device 1 is not bent or damaged from impact.

That is, the optical guide 150 is disposed to surround the light source 120 or the light source package 125, and guides the light emitted from the light source 120 to spread in a horizontal direction while being transmitted to the optical sheet 40. , Mura phenomenon can be prevented even at a relatively short optical distance d. Therefore, the backlight unit 100 including the optical guide 150 and the display device 1 including the same can prevent deterioration of image quality and at the same time reduce the thickness to implement a slim design.

6 is a cross-sectional view of a plurality of light source assemblies 130 according to an embodiment of the present disclosure.

Referring to FIG. 6 , the light source package 125 and the optical guide 150 according to an embodiment of the present disclosure may be implemented in various structures.

The light source package 125 may include a light source 120 and a molding structure coupled to an outer circumferential surface of the light source 120 to diffuse light. Since the light source package 125 has the same or similar structure or material as the prior art light source package 125, a detailed description thereof will be omitted. The top surface of the light source package 125 may contact the optical sheet 40 and the side surface may contact the optical guide 150 .

The inner surface 153 of the optical guide 150 may be in contact with the outer circumferential surface of the light source package 125 to receive light emitted in a lateral direction of the light source package 125 . At least a portion of the upper surface 151 of the optical guide 150 may be coated with a reflective member, and light may be guided to the outer surface 155 of the optical guide 150 . Therefore, light emitted from the light source 120 may be emitted from the upper surface of the light source package 125 and the outer circumferential surface of the optical guide 150 .

The space 127 spaced apart between the optical guide 150 and the adjacent optical guide 150, that is, the space 127 of the light source assembly 130 may be provided as an empty space and may be in a vacuum state or filled with air, or a light diffusion material. (126, see FIG. 8) may be filled.

Through this structure, the display device 1 arranges the outer surface 155 of the optical guide 150 in the space between the light sources 120 or between the light source package 125 and another light source package 125. Accordingly, the light of the light source 120 can be stably guided and diffused, the optical distance d can be minimized, image quality degradation can be prevented, and the thickness of the display device 1 can be reduced.

FIG. 7 is a graph illustrating optical profiles of the plurality of light source assemblies 130 at the top and side portions according to an embodiment of the present disclosure.

Referring to FIG. 7 , light distribution of the display device 1 including a plurality of light source assemblies 130 including optical guides 150 may be predicted.

In detail, FIG. 7 is an optical profile illustrating the luminance of an area adjacent to the plurality of light source assemblies 130 when the plurality of light source assemblies 130 are spaced apart and power is applied.

FIG. 7 is a display device 1 including four light source assemblies 130, and the position of the light source 120 or light source package 125 of each light source assembly 130 is shown in FIG. 7 (X-axis position). .

Referring to the luminance of the upper part and the side part of the display device 1 of FIG. 7 , the luminance of the display device 1 is 0.0008 in the entire inner range of the area where the light sources 120 of the plurality of light source assemblies 130 are disposed. It can be seen that it is maintained evenly over W/mm^2.

Although not shown in the drawing, when the optical guide 150 is not included, a large deviation in luminance occurs within a range in which the plurality of light sources 120 or the light source package 125 are disposed, and thus, stains are observed and mura phenomena may occur. In contrast, in the display device 1 including the plurality of light source assemblies 130 of the present disclosure, relatively high luminance is maintained uniformly within a range in which the plurality of light source assemblies 130 are disposed, and the Mura phenomenon can be minimized. can be expected to be possible.

Therefore, referring to the optical profile of FIG. 7 , the light source assembly 130 can diffuse the light of the light source 120 relatively widely through the optical guide 150, and the separation distance between the plurality of light source assemblies 130 Also, the light of the light source 120 can be uniformly diffused. As a result, the backlight unit 100 of the present disclosure can prevent the Mura phenomenon of the display device 1 and improve image quality.

8 is a cross-sectional view of the light source assembly 130 according to an embodiment of the present disclosure.

Referring to FIG. 8 , the light source assembly 130 according to an embodiment of the present disclosure may include a light diffusion material 126 .

The light diffusion material 126 is a material filled in the diffusion region 123 formed by spaced apart arrangement of the light source 120 and the inner surface 153 of the optical guide 150, and the light diffusion material 126 is a diffusion region ( 123) to diffuse light.

For example, the light diffusion material 126 may be made of a material including at least one of silicon, optical resin, and solid phosphor. Among them, the solid phosphor may be a self-emitting material or a quantum dot (Quantun Dot, QD) existing in plurality in the medium of the light diffusion material 126 .

In detail, the solid phosphor of one embodiment may be a QD particle that converts the color of light emitted from the light source 120 or improves the amount of light by using quantum dot (QD) light emission. The solid phosphor may improve image quality by adjusting color coordinates and color gamut of the display device 1 . After disposing the light source 120 and the optical guide 150 in the backlight unit 100 , the light diffusion material 126 may be implemented by dispensing QD ink on the diffusion area 123 .

9 is a flowchart illustrating a manufacturing method of the display device 1 according to an embodiment of the present disclosure.

Referring to FIG. 9 , the manufacturing method of the display device 1 according to an embodiment of the present disclosure includes preparing a substrate 110 (S10) and disposing a light source 120 on one surface of the substrate 110 ( The backlight unit 100 may be manufactured through (S20) and arranging the optical guide 150 to surround the light source 120 (S30), and after manufacturing the backlight unit 100, the optical sheet 40 is attached. It is possible to manufacture the display device 1 including the step (S40) of doing. Each of the above-described steps may be performed sequentially, or at least one or more steps may be omitted.

In the step of arranging the optical guide 150 (S30), the upper surface of the light source 120 surrounds the light source 120 and includes an open upper surface 151 and transmits some of the light emitted by the light source 120. It may be a step of arranging the optical guide 150 that receives the transmission to the inner surface 153 and guides it to the outer surface 155, and the structure and cross-sectional shape of the optical guide 150 are the same as those of the optical guide 150 described above. or similarly implemented.

In various embodiments, in the step of disposing the optical guide 150 (S30), the optical guide 150 may be formed higher than the height of the light source 120, or the inner surface 153 of the optical guide 150 At least a portion of may be disposed to be spaced apart from the light source 120 to form the diffusion region 123 . In addition, the light diffusion material 126 is disposed in a space spaced apart from the light source 120 and the inner surface 153 of the optical guide 150, and the light diffusion material 126 of FIG. 8 is filled in the light source assembly 130 can be implemented.

In the above-described manufacturing method, the backlight unit 100 or the light source assembly 130 may be manufactured through the step of disposing the optical guide 150 (S30). The light source assembly 130 may be separated into a single assembly unit and attached to and utilized as a light emitting source of the backlight unit 100 or other electronic devices (not shown).

Attaching the optical sheet 40 ( S40 ) may be a step of attaching the optical sheet 40 made of a light-transmitting material to the top of the optical guide 150 . The optical sheet 40 may be spaced apart from the substrate 110 so that the intermediate housing 52 supports it, and at least a portion of the upper surface 151 of the optical guide 150 is disposed on the optical sheet 40 . ) can be attached to Although not shown in the drawings, a diffusion sheet 30 or a display panel 20 may be coupled to an upper portion of the optical sheet 40 .

Although the preferred embodiments of the present disclosure have been shown and described above, the present disclosure is not limited to the specific embodiments described above, and is commonly used in the technical field to which the present disclosure belongs without departing from the gist of the present disclosure claimed in the claims. Of course, various modifications and implementations are possible by those with knowledge of, and these modifications should not be individually understood from the technical spirit or perspective of the present disclosure.

Claims (15)

1. Board;

   a light source disposed on one surface of the substrate to emit light; and

   It is a three-dimensional structure surrounding the light source, and an optical guide for guiding a part of the light emitted from the light source in a lateral direction of the light source; includes,

   The optical guide,

   an upper surface where an opening through which light irradiated by the light source passes is formed at a position corresponding to the light source;

   an inner surface surrounding the light source and receiving light irradiated by the light source; and

   and an outer surface receiving light from the inner surface and emitting the light to the outside of the optical guide.
2. According to claim 1,

   The upper surface of the optical guide,

   A backlight unit, wherein a reflective member that reflects light inside the optical guide and blocks emission to the outside of the optical guide is applied to at least a partial region.
3. According to claim 2,

   The upper surface of the optical guide,

   The backlight unit of claim 1 , wherein a portion of light inside the optical guide is emitted to the outside of the optical guide through a partial area other than the partial area to which the reflective member is applied.
4. According to claim 1,

   The optical guide,

   A backlight unit comprising a lower surface opposite to the upper surface and coated with a reflective member for reflecting light inside the optical guide.
5. According to claim 1,

   An outer surface of the optical guide is parallel to the inner surface of the backlight unit.
6. According to claim 1,

   The inner surface of the optical guide,

   A backlight unit that inclines away from the light source as it develops from top to bottom.
7. According to claim 1,

   The backlight unit of claim 1 , wherein the opening of the upper surface has an area smaller than an area of the upper surface of the light source.
8. According to claim 1,

   The upper surface of the optical guide is formed flat,

   The optical guide has the same height as the height of the light source, the backlight unit
9. According to claim 1,

   The optical guide has a height greater than the height of the light source,

   The backlight unit, wherein the inner surface faces a part of the upper surface and side surfaces of the light source and receives the light emitted from the light source.
10. According to claim 1,

    The light source includes a diffusion molding that surrounds an outer circumferential surface of the light source and diffuses light,

    The optical guide is disposed to surround the light source and the diffusion molding.
11. According to claim 1,

    A backlight unit comprising: a diffusion region in which at least a portion of an inner surface of the optical guide is formed to be spaced apart from the light source.
12. According to claim 11,

    A backlight unit comprising a light diffusion material disposed in the diffusion area to diffuse light.
13. According to claim 12,

    The light diffusion material,

    A backlight unit made of a material containing at least one of silicon, optical resin, and solid phosphor.
14. Board;

    a light source disposed on one surface of the substrate to emit light;

    an optical guide that is a three-dimensional structure surrounding the light source and guides a portion of light emitted from the light source toward a side of the light source; and

    An optical sheet disposed above the light source and made of a light-transmitting material that transmits light;

    The optical guide,

    an upper surface where an opening through which light irradiated by the light source passes is formed at a position corresponding to the light source;

    an inner surface surrounding the light source and receiving light irradiated by the light source; and

    An outer surface receiving light from the inner surface and emitting the light to the outside of the optical guide;

    The optical guide,

    At least a portion of the upper surface is in contact with the optical sheet.
15. Preparing a substrate;

    arranging a light source on one surface of the substrate;

    arranging an optical guide surrounding the light source, including an open top surface of the light source, receiving part of the light emitted from the light source to an inner surface and guiding the optical guide to an outer surface; and

    and attaching an optical sheet made of a light-transmitting material to an upper portion of the optical guide.

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