KR20110024613A - Backlight unit and display apparatus including the same - Google Patents

Abstract

PURPOSE: A backlight unit and a display device including the same are provided to reduce a manufacturing cost having uniform brightness and maintain uniform brightness of the backlight unit. CONSTITUTION: A light emitting unit includes a resin layer to cover the upper part of the light emitting unit. A first light source is arranged on a center part of a substrate. A second light source is arranged around the first light source. A reflective sheet is attached to the outside of the second light source. The refractive index of the resin layer is 1.6 to 1.4. A cover forms a rear side of the backlight unit. The cover is formed in a connection hole in order to expose a connector. A front cover is fixed to a display module(20).

Description

Backlight unit and display apparatus including the same {Backlight unit and display apparatus including the same}

The present invention relates to a backlight unit and a display device including the same.

In general, liquid crystal displays (LCDs) are increasingly wider in application due to features such as light weight, thinness, and low power consumption. In accordance with this trend, the liquid crystal display is widely used in cellular phones, notebook computers, monitors, TVs, and lighting fields.

Since the liquid crystal display is not a self-luminous display device, it includes a display panel for displaying an image and a display module having a backlight unit disposed on a rear surface of the display panel to provide light.

The backlight unit may be divided into a direct method and an edge method according to the position of the light source.

In the edge method, the light source is disposed on the side of the display module, and the light emitted from the light source is irradiated onto the entire surface of the display panel using a light guide plate. On the other hand, in the direct method, a plurality of light sources are disposed on the back of the display panel to directly irradiate light directly under the display panel, so that the luminance can be increased by a plurality of light sources compared to the edge method, and the light emitting surface is wider. There is an advantage to this.

On the other hand, in recent years, a backlight unit using a light emitting diode (LED) as the light source has been released. The light emitting diode is miniaturized and thinned by applying a fine semiconductor process, and thus is used to implement a thinner and lighter display module than a display module using a cold cathode fluorescent lamp (CCFL).

However, the above conventional technology has the following problems.

The direct type backlight unit has a problem in that it is difficult to realize uniform luminance because a difference in luminance occurs between a region where the light source is disposed and a region where the light source is not disposed.

In particular, there is a problem in that a hot spot having a higher luminance than the surroundings is generated in a region where the light source is disposed.

In order to solve this problem, when increasing the distance between the display panel and the backlight unit, or increasing the distance between the diffusion plate and the optical sheets disposed in the backlight unit, the thickness of the display module There is a problem of thickening.

In addition, since the light emitting diode is small in size, the amount of light (light flux) to be supplied is small, and thus a large number of light emitting diodes of hundreds to thousands of light emitting diodes is required when a large size direct-type backlight unit is manufactured. Therefore, there is a problem that the manufacturing cost is increased.

The present invention has been proposed to solve the above problems, and an object thereof is to provide a thin back light unit and a display device including the same.

Another object of the present invention is to provide a backlight unit having a uniform brightness and a display device including the same.

In addition, an object of the present invention is to provide a backlight unit and a display device including the same, in which manufacturing cost is reduced.

A backlight unit according to an embodiment of the present invention for achieving the above object, the light emitting unit for emitting light and arranged adjacent to each other; And a resin layer formed to cover an upper surface of the light emitting unit, wherein the light emitting unit includes: a substrate; A first light source disposed in the center of the substrate and emitting upward; And at least one second light source disposed around the first light source and emitting toward the side.

In another aspect, a backlight unit according to an embodiment of the present invention, a substrate; A plurality of first light sources disposed on the substrate and configured to emit light upward; At least one second light source disposed around each of the first light sources and emitting toward the side; And a resin layer formed to surround the first light source and the second light source.

In another aspect, a display device includes a display module including a backlight unit and a display panel disposed on a front surface of the backlight unit; A front cover to which the display module is fixed; And a back cover covering a rear surface of the display module, wherein the backlight unit is in close contact with the display panel.

According to the backlight unit and the display device including the same according to the embodiment of the present invention as described above, since the improved backlight unit structure is provided, there is an advantage that the thickness of the backlight unit and the display device can be made thin.

In addition, there is an advantage that the thickness of the display device can be made thinner by closely attaching the backlight unit to the display panel.

In addition, there is an effect that the image quality can be improved by providing a backlight unit having a uniform brightness.

In addition, the manufacturing cost can be reduced by reducing the number of light emitting diodes used.

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

1 is an exploded perspective view schematically illustrating a configuration of a display device including a backlight unit according to a first embodiment of the present invention, and FIG. 2 is a partial cross-sectional view of the display module of FIG. 1.

1 and 2, the display device 1 according to the first embodiment of the present invention includes a display module 20 for displaying an image, a front cover 12 surrounding the display module 20, and The back cover 12 may be included.

The front cover 11 may include a front panel (not shown) of a transparent material that transmits light, and the front panel may be disposed at a predetermined interval of the display module 20, particularly, the display panel 300 to be described later. It is disposed on the front surface, and protects the display module 20 from external impact, and transmits the light emitted from the display module 20 so that the image displayed on the display module 20 can be seen from the outside.

The back cover 12 may protect the rear of the display module 20 and may be fixed to the front cover 11. In particular, when the backlight unit 200 to be described later is provided in the form of a film, the back cover 12 may be fixed only to the front cover 11 without being combined with the display module 20 for firm fixing. .

The display module 20 includes a display panel 300 for displaying an image and a backlight unit 200 in close contact with a rear surface of the display panel 300 and irradiating light to the display panel 300.

The display panel 300 includes a thin film transistor (TFT) substrate 320, a color filter substrate 330, and two substrates 320 and 330 bonded to each other to maintain a uniform cell gap. A liquid crystal layer interposed therebetween, a lower polarizer 310 disposed on a bottom surface of the thin film transistor substrate 320, and an upper polarizer 340 disposed on an upper surface of the color filter substrate 330. can do. Side of the display panel 300 is further provided with a gate and a data driver (not shown) for generating a driving signal for driving the display panel 300.

The color filter substrate 330 includes a plurality of pixels including red (R), green (G), and blue (B) sub-pixels. When light is applied, the color filter substrate 330 may display an image corresponding to a color of red, green, or blue. Generate.

On the other hand, the pixels are generally composed of red, green, and blue subpixels, but the red, green, blue, and white (W) subpixels constitute one pixel, but are not necessarily limited thereto. Can be.

The thin film transistor substrate 320 switches a pixel electrode (not shown) as a switching element. The common electrode (not shown) and the pixel electrode convert the arrangement of the molecules of the liquid crystal layer according to a predetermined voltage applied from the outside. The liquid crystal layer is composed of a plurality of liquid crystal molecules, the liquid crystal molecules change the arrangement corresponding to the voltage difference generated between the pixel electrode and the common electrode, thereby providing from the backlight unit 200 The light is incident on the color filter substrate 330 according to the change in the molecular arrangement of the liquid crystal layer.

Such a structure and configuration of the display panel 300 is only an example, and the embodiments may be changed, added, or deleted within the scope of the spirit of the present invention.

The backlight unit 200 is adhesively fixed to the rear surface of the display panel 300, and for this purpose, an adhesive layer (not shown) may be further provided between the lower polarizer 310 and the backlight unit 200. have.

Hereinafter, a detailed structure of the backlight unit 200 will be described with reference to the drawings.

3 is a partial cross-sectional view showing the configuration of the backlight unit of FIG. 2, and FIG. 4 is a partial perspective view showing the arrangement of the light emitting unit of FIG. 3.

3 and 4, the backlight unit 200 includes a light emitting unit 210 that emits light, a resin layer 230 provided to cover an upper portion of the light emitting unit 210, and the resin layer ( An optical sheet 250 attached to an upper surface of the 230, and a cover 290 on which the light emitting unit 210 is seated may be included. In addition, the light emitting unit 210 may be further provided with a reflective sheet 220 for reflecting light.

The light emitting unit 210 is a connector for supplying power to a substrate 211, a first light source 212 and a second light source 213 disposed on the substrate 211, and the light sources 212 and 213. 214 may include.

A plurality of light emitting units 210 may be arranged in the cover 100 in an array form. That is, the light emitting unit 210 may be disposed so that each side of the substrate 211 is in contact with each other to implement a rectangular backlight unit.

In this case, each light emitting unit 210 may be independently controlled since the light emitting unit 210 is powered by the connector 214. That is, the light may be controlled so that only a part of the backlight unit 200 emits light. In other words, since the contrast between the bright area and the dark area in the display module 10 can be more surely obtained, a high contrast ratio can be realized.

The array structure of the light emitting unit 210 is just an example, and a plurality of light sources are disposed on one substrate, and a predetermined number of light sources are grouped into one group to control each group by dividing the driving region. The same effect can be obtained. In the present embodiment, a structure in which the light emitting units 210 are arranged in an array form will be described as an example.

The substrate 211 may be formed in a square or rectangular shape, and a carbon nanotube electrode pattern (not shown) may be formed on an upper surface thereof. The carbon nanotube electrode pattern contacts the electrodes formed on the light sources 212 and 213 to electrically connect the connector 214 and the light source 212.

The substrate 211 may be a substrate formed of one of polyethylene terephthalate, glass, polycarbonate, and silicon, and may be formed in a flexible film form.

The light sources 212 and 213 may be one of a light emitting diode (LED) chip or a light emitting diode package having at least one light emitting diode chip. In the present embodiment, a light emitting diode package is provided as the light source 212.

In addition, such a light emitting diode package is classified into a top view method and a side view method according to a direction in which the light emitting surface is directed. The top view method is a type that emits light toward the upper side of the package, and the side view method is a method that emits toward the side of the package.

The top light source package 212 is provided with the top view package to emit light upward, and the second light source 213 is provided with the side view package to emit light toward the side. Allow it to diverge.

The first light source 212 includes a first case 212b in which a light emitting diode chip is mounted, and a first light emitting surface 212a emitting upward light emitted from the light emitting diode chip.

The LED chip may emit light of various colors, such as white, red, green, blue, white, and the like, and the color light may be emitted to the light emitting surface 212a. Via the dispensed fluorescent material, the light may be converted into white light and emitted outside the first light source 212. In addition, a plurality of light emitting diode chips emitting light of different colors may be provided in the case 212b, and light emitted from each chip may be mixed to generate white light.

The first case 212b may include a molding part (not shown) formed to seat the LED chip, and a lead frame (not shown) coupled to the molding part and fixed to the substrate.

The second light source 213 includes a second case 213b in which a light emitting diode chip is mounted, and a second light emitting surface 213a for laterally emitting light emitted from the light emitting diode chip. Since the operation principle of the second light source 213 is the same as the first light source 212, a detailed description thereof will be omitted.

In addition, the directing angle of the light emitted from the light sources 212 and 213 may vary depending on the shape of the light emitting surfaces 212a and 213b and the arrangement of the light emitting diode chips. In this embodiment, a case in which the directivity angles of the light sources 212 and 213 are about 120 degrees will be described as an example.

The first light source 212 is disposed at the center of the substrate 211. Since the first light source 212 emits light upward, the light emitted from the first light source 212 spreads in a circular shape. If necessary, a plurality of first light sources 212 may be disposed. In this case, the first light sources 212 may be disposed to be symmetrical with respect to the center of the substrate 211.

In addition, at least one second light source 213 is disposed around the first light source 212. In particular, the second light source 213 may be disposed to surround the first light source 212, and the second light emitting surface 213a may be disposed to face the outside of the substrate 211. The second light source 213 may be formed in a polygonal shape surrounding the first light source 212, and preferably, the second light source 213 may be disposed at a vertex or corner of a regular polygon. .

As another example, the second light source 213 may be provided at a position separated by a predetermined distance to the side of the first light source 212, and may be disposed to emit light toward one direction. In this case, the second light source 213 may be arranged to emit light in a direction crossing each other with the second light source of the adjacent light emitting unit 210. For example, the second light sources of the n rows of light emitting units emit light toward the right side, and the second light sources of the n + 1 rows of light emitting units emit light toward the left side.

In the present embodiment, the second light source 213 is described as an example of being disposed in the corner of the square, the second light source 213 is disposed in the center of each corner.

On the other hand, the upper surface of the substrate 211 is further provided with a reflective sheet 220 for reflecting the light emitted from the light source (212). In particular, the reflective sheet 220 may be disposed outside the second light source 213 to reflect the light emitted laterally to emit light upward.

In detail, a hole in which the light sources 212 and 213 may be inserted is formed in the reflective sheet 220, and may be attached to the substrate 211. In the present embodiment, since the second light source 213 is disposed to form a square, a square hole may be formed in the reflective sheet 220.

The reflective sheet 220 may be formed to correspond to the size of the light emitting unit 210 and may be attached to each light emitting unit, or may be formed to have a size corresponding to the entire backlight unit 200 so that one reflective sheet may be formed. The light emitting unit 210 may be attached to the array.

The reflective sheet 220 may include a white pigment such as titanium oxide dispersed in a sheet made of a synthetic resin, a metal deposition film laminated on a surface thereof, or a bubble dispersed to scatter light in a sheet made of a synthetic resin. In addition, silver (Ag) may be coated on the surface to increase the reflectance.

In addition, the reflective sheet 220 may be selectively provided, and may be attached to the bottom surface of the substrate 211 when the substrate 211 is formed of a transparent material.

The resin layer 230 transmits light emitted from the light sources 212 and 213 and simultaneously diffuses the light so that the backlight unit 200 has a uniform brightness. The resin layer 230 may be formed to surround the first light source 212 and the second light source 213, and may be formed to be in close contact with at least the light emitting surfaces 212a and 213a. In addition, the resin layer 230 may be formed to completely cover the first light source 212 and the second light source 213 to be in close contact with the reflective sheet 220.

The resin layer 230 may be formed of a light transmissive material, and may be formed of a predetermined resin having a refractive index of about 1.4 to 1.6. For example, it may be formed of any one material selected from the group consisting of polyethylene terephthalate, polycarbonate, polypropylene, polyethylene, polystyrene and polyepoxy, silicone, acrylic, and the like. However, the refractive index and the material of the resin layer 230 are not limited thereto, and any resin may be used as a material as long as light transmittance is satisfied.

In addition, the resin layer 230 may include a polymer resin having a predetermined adhesiveness to be in close contact with the light emitting unit 210. For example, unsaturated polyester, methyl methacrylate, ethyl methacrylate, isobutyl methacrylate, normal butyl methacrylate, normal butyl methyl methacrylate, acrylic acid, methacrylic acid, hydroxyethyl methacrylate, Hydroxypropyl methacrylate, hydroxy ethyl acrylate, acrylamide, metyrol acrylamide, glycidyl methacrylate, ethyl acrylate, isobutyl acrylate, normal butyl acrylate, 2-ethylhexyl acrylate polymer or Acrylic type, urethane type, epoxy type, melamine type, etc., such as a copolymer or a terpolymer, can be used.

The resin layer 230 may be formed by applying a liquid or gel resin on the upper portion of the light emitting unit 210 and curing it, or may be separately manufactured and adhered to the light emitting unit 210.

As the thickness of the resin layer 230 increases, light emitted from the light source 212 may be spread more widely, so that light having a more uniform brightness may be provided to the display panel 300. However, when the thickness of the resin layer 230 is increased, the thickness of the display module 20 is increased to increase the thickness of the display device 1 and the amount of light absorbed by the resin layer 230 is increased. As a result, the luminance of light provided to the display panel 300 may be reduced as a whole. Therefore, the thickness of the resin layer 230 may be formed to a thickness of 0.1 to 4.5mm so as to have a uniform brightness without hot spots and the like without significantly reducing the brightness.

Light emitted through the resin layer 230 is incident on the display panel 300 via the optical sheet 250. Since most of the light emitted from the resin layer 230 is light refracted in the groove 230, the light is incident on the optical sheet 250 at a predetermined angle. However, since the light incident on the display panel 300 is vertical when the light efficiency is high, the optical sheet 250 has the light emitted from the resin layer 230 perpendicular to the display panel 300. To be incident.

The optical sheet 250 may include a diffusion sheet, a prism sheet, and a protective sheet. At this time, the sheets are provided in a state of being bonded or adhered to each other without being spaced apart from each other. Therefore, the thickness of the optical sheet 250 can be minimized.

The diffusion sheet disperses the light incident through the resin layer 230 to prevent the light from being partially concentrated and makes the luminance uniform. The prism sheet collects light whose brightness has fallen sharply through the diffusion sheet so that light may be incident vertically toward the display panel 300. The protective sheet diffuses the light passing through the prism sheet to the entire area of the display panel 300 and prevents the prism sheet from being damaged. The configuration of such an optical sheet is only one example, and it will be possible to add, change, or delete the embodiments within the scope of the spirit of the present invention. For example, at least one or more of the diffusion sheet, the prism sheet, and the protective sheet may be removed, and various functional layers may be further added.

Meanwhile, the bottom surface of the optical sheet 250 is in close contact with the resin layer 230, and the top surface is in close contact with the bottom surface of the display panel 300.

The cover 290 supports the backlight unit 200 and the display panel 300 and is formed to allow the backlight unit 200 to be seated. In addition, the cover 290 is formed with a connection hole 291 at a point corresponding to the position of the connector 214. The connection hole 291 is formed to have a larger size than the connector 214 so that a predetermined jack can be smoothly inserted into the connector 214. Therefore, the connector 214 is exposed to the rear of the cover 290, the operator can work conveniently.

In addition, the connection hole 291 is formed, and the connector 214 formed to protrude on the rear surface of the substrate 211 is fitted into the connection hole 291, so that the substrate 211 is covered by the cover 290. ) Can be completely adhered to. Therefore, since heat generated from the substrate 211 can be smoothly transferred to the cover 291 by conduction, heat dissipation performance of the display module 10 may be improved.

As such, the cover 290, the backlight unit 200, and the display panel 300 are configured to be in close contact with each other, so that the thickness of the display module 10 may be minimized.

In addition, since the light emitted from the first light source 212 and the light emitted from the second light source 213 complement each other where the intensity of light is weakened, the backlight unit 200 has a uniform brightness as a whole. Can be.

Hereinafter, the light emitted from the light emitting unit 210 will be described in detail with reference to the accompanying drawings.

5 is a partial plan view of the backlight unit of FIG. 3, and FIG. 6 is a partial cross-sectional view of the backlight unit of FIG. 3.

Referring to FIG. 5, when viewed from the upper side of the light emitting unit 210, the light emitted from the first light source 212 is circularly spread around the first light emitting surface 212a and the first light is emitted. Light extends from the light source 212 to a predetermined distance. In this case, the area of the light of the first light source 212 is referred to as A.

In addition, light emitted from the second light source 213 is emitted laterally at an exit angle of a predetermined angle Θ1, and a region of the light emitted from the second light source 213 is referred to as B.

The region B may extend beyond at least the substrate 211 to a neighboring substrate. Since the edge of the substrate 211 is far from the light sources 212 and 213 provided to the substrate 211, the light intensity is weak. However, when the light emitted from the second light source 213 reaches the edge of the neighboring substrate, the light may overlap so that the light intensity may increase. Therefore, the backlight unit 200 may have a uniform luminance as a whole.

The second light sources 213 are spaced apart from the first light source 212 by a predetermined distance D1 so that the light emitted from each second light source, that is, the B region, may overlap each other, and the Θ1 is adjusted. . Since the distance from which the light emitted from the second light source 213 reaches reaches a limit, when D1 is too large, an overlapping area may not occur between the B areas, and therefore, D1 should be controlled to a predetermined distance or less. , Θ1 should also be implemented at a certain angle or more.

In this case, a point at which the overlap between the B regions starts is referred to as P. The position of the point P is controlled by the D1 and the Θ1. In detail, the smaller the D1 and the larger the Θ1, the closer the P point is to the center of the substrate 211.

The D1 is adjusted so that at least the A region and the B region can overlap. That is, the D1 is adjusted to allow the second light source 213 to emit light in the area A. FIG. Accordingly, light emitted from the second light source 213 may be irradiated to an area where the intensity of light emitted from the first light source 212 is weakened to increase the light intensity.

In addition, the D1 may be adjusted so that the P point is not too close to the first light source 212. When the point P is too close to the first light source 212, the intensity of light overlapping from the first light source 212 and the second light source 213 becomes too strong to generate a hot spot. Because it can.

In view of the above, it is preferable that the D1 is provided in a range of 1 mm to 5 mm.

In addition, the D1 and Θ1 may be adjusted so that the P point is located inside the A area. When the point P is located outside the area A, the area from the area A to the point P does not reach any of the light emitted from the first light source 212 and the second light source 213. It becomes a dark area. Therefore, the D1 and Θ1 may be adjusted so that the P point is located at least inside the A area. In addition, by increasing the amount of current applied to the first light source 212 to enlarge the area A, the P point may be located inside the area A.

On the other hand, if the distance D2 from the first light source 212 to the edge of the substrate 211 is too close, the number of light sources used for the entire backlight unit 200 is increased, the manufacturing cost is increased For example, if the light is too far, the intensity of light at the edge becomes weak, so that it is difficult to realize uniform luminance. Therefore, the D2 is preferably provided in the range of 10mm to 25mm.

Referring to FIG. 6, light emitted from the first light source 212 passes through the resin layer 230 while spreading in a circular shape as described above (C). And, a part of the light emitted from the second light source 212 passes directly through the resin layer (D), while the other part proceeds downward and is reflected by the reflective sheet 220 (D ' ). The light reflected by the reflective sheet 220 further extends laterally to diffuse to neighboring substrates. Therefore, as described above, the overlapping effect of light may occur at the edge of the substrate, thereby increasing the light intensity.

According to the backlight unit 200 according to the first embodiment of the present invention as described above, the first light source 212 and the area where the light intensity is weakened because the distance from the light source (212, 213) Since light emitted from the second light source 213 overlaps each other, the intensity of light may be prevented from being weakened. Therefore, the backlight unit 200 may have a uniform luminance as a whole.

In addition, the backlight unit having a high luminance as a whole by disposing the second light source 213 that emits light having an intensity smaller than that of the first light source 212 around the first light source 212. 200 may be provided.

In addition, the second light source 212 that emits light laterally around the first light source 212 that emits light upward, the reflection to reflect the light emitted laterally to be widely diffused By providing the sheet 220, the number of light sources per unit area of the backlight unit 200 may be reduced. Therefore, manufacturing cost can be reduced.

Hereinafter, a backlight unit according to the second and third embodiments of the present invention will be described with reference to the drawings. However, since the second and third embodiments have a difference in the number and arrangement of the second light sources as compared with the first embodiment, the differences are mainly described, and the same reference numerals and reference numerals are used for the same parts. .

7 is a partial plan view of a backlight unit according to a second embodiment of the present invention, and FIG. 8 is a partial plan view of a backlight unit according to a third embodiment of the present invention.

Referring to FIG. 7, the second light source 213 may be arranged in a pentagonal shape around the first light source 212. That is, the second light source 213 may be disposed at the center of each corner of the regular pentagon with respect to the first light source 212.

In this case, since the number of the second light sources 213 is increased, the direction angle θ2 of the second light source 213 may be provided at an angle smaller than the Θ1. In addition, since the intersection point P ′ between the region B ′ in which the light of the second light source 213 is spread may be located closer to the first light source 212, the amount of overlapping light is increased, thereby increasing the overall amount of light. The brightness can be raised.

Referring to FIG. 8, the second light source 213 may be disposed in an equilateral triangle shape around the first light source 212. That is, the second light source 213 may be disposed at the center of each corner of the equilateral triangle around the first light source 212.

In this case, since the number of the second light sources 213 is reduced, the direction angle θ3 of the second light source 213 may be provided at an angle greater than the Θ1. In addition, since the intersection point P ″ between the region B ″ where the light of the second light source 213 is spread may be formed at a position farther from the first light source 212, the first light source 212. By increasing the magnitude of the current applied to the ()) it is possible to make the area (A ") through which the light of the first light source 212 spreads wider.

The arrangement of the second light source 213 is just an example, and the second light source 213 may be arranged in various forms so as to overlap with the light emitted from the first light source 212.

Hereinafter, a backlight unit according to a fourth embodiment of the present invention will be described with reference to the drawings. However, since the fourth embodiment has a difference in that a groove is further provided as compared with the first embodiment, the description will be mainly focused on the difference, and the description and reference numerals of the first embodiment are used for the same parts.

9 is a partial cross-sectional view of the backlight unit according to the fourth embodiment of the present invention.

Referring to FIG. 9, grooves 231 are formed in the resin layer 230 of the backlight unit according to the fourth exemplary embodiment of the present invention to refract and diffuse light.

The groove 231 may be formed by engraving the resin layer 230, and air is filled therein.

The groove 231 may be engraved with a polygonal pyramid such as a cone, a triangular pyramid, a square pyramid, and the like so that the cross section forms a triangle. The groove 231 may be formed in the resin layer 230 to correspond to the position of the first light source 212.

In addition, the width of the groove 231 may be formed larger than the width of the first light emitting surface 212a so that all of the light emitted vertically upward from the first light emitting surface 212a may be refracted to the outside. The grooves 231 are formed to be spaced apart from each other by a predetermined distance so as to secure an area to which the optical sheet 250 is adhered to the resin layer 230. Therefore, even if a plurality of grooves 231 are formed in the resin layer 230, the optical sheet 250 may be firmly adhered to the resin layer 230.

In addition, the groove 231 may be formed so that a part of the light emitted from the first light source 212 may be totally reflected. The totally reflected light is reflected by the reflective sheet 220 and proceeds to the outside of the resin layer 230 again. Therefore, the light emitted from the first light source 212 can be spread more widely.

Hereinafter, a backlight unit according to a fifth embodiment of the present invention will be described with reference to the drawings. However, the fifth embodiment has a difference in that bubbles are formed in the resin layer compared with the first embodiment. Therefore, the fifth embodiment will be described mainly for differences, and the description and reference numerals of the first embodiment will be used for the same parts.

10 is a partial cross-sectional view of the backlight unit according to the fifth embodiment of the present invention.

Referring to FIG. 10, bubbles 237 having various sizes are formed in the resin layer of the backlight unit according to the fifth embodiment of the present invention. Since the bubble 237 is filled with air, light is refracted when the light proceeds from the resin layer 230 to the bubble 237. That is, the light emitted from the light sources 212 and 213 by the bubble 237 may be refracted in various patterns while passing through the resin layer 230, thereby maximizing the light diffusion effect.

At this time, the bubble 237 may be formed through the thermal decomposition of a predetermined blowing agent, the diameter of the bubble 237 may be 1㎛ to 20㎛.

If the diameter of the bubble 237 is small, the number of the bubbles 237 is increased, so that the refractive effect of the resin layer 230 may be improved. However, if the diameter of the bubble 237 is too small, the light source 212. , 213 may cause interference of light emitted from the light source. Therefore, the diameter of the bubble 237 is 1㎛ or more, so that the refraction effect can be improved as long as the interference of light does not occur.

In addition, when the diameter of the bubble 237 is large, the number of bubbles 237 is reduced, so that light is refracted in various patterns sufficiently and does not diffuse while passing through the resin layer 230. In this case, when the thickness of the resin layer 230 is increased in order to secure the number of bubbles 237, there is a problem that the thickness of the backlight unit 200 becomes thick. Therefore, the diameter of the bubble 237 is formed to be 20㎛ or less, so that the light emitted from the light source (212, 213) is refracted or diffused by a predetermined level or more to enter the optical sheet 500 and at the same time The backlight unit 200 may be thinned.

Hereinafter, a backlight unit according to a sixth embodiment of the present invention will be described with reference to the drawings. However, since the sixth embodiment differs in that scattering particles are formed in the resin layer compared with the first embodiment, the differences will be mainly described, and the same reference numerals and reference numerals are used for the same parts. .

11 is a partial cross-sectional view of the backlight unit according to the sixth embodiment of the present invention.

Referring to FIG. 11, the resin layer 230 of the backlight unit according to the sixth exemplary embodiment includes scattering particles 238 that scatter or refract light. Therefore, the light emitted from the light source 212 can be spread more widely.

The scattering particles 238 may be formed of a material having a refractive index different from that of the resin layer 230 in order to scatter or refract light emitted from the light source 212. For example, the scattering particles 231 may be composed of polymethyl methacrylate / styrene copolymer (MS), polymethyl methacrylate, polystyrene, silicon, titanium dioxide (TiO 2), silicon dioxide (SiO 2), or the like. It may be configured by combining the above materials.

In addition, the scattering particles 238 may be formed of a material having a lower refractive index than the material constituting the resin layer 230.

In the resin layer 230 according to the present exemplary embodiment, the scattering particles 238 are mixed with a resin in a liquid or gel and then coated on the upper surfaces of the light emitting unit 210 and the reflective sheet 220. It can be formed by post curing.

Hereinafter, a backlight unit according to a seventh embodiment of the present invention will be described with reference to the drawings. However, the seventh embodiment has a difference in that a refractive layer is further provided inside the resin layer as compared with the first embodiment. Therefore, the seventh embodiment will be described based on the difference. Use it.

12 is a partial cross-sectional view of the backlight unit according to the seventh embodiment of the present invention.

Referring to FIG. 12, the first light source 212 is surrounded by a refractive layer 235 having a larger refractive index than the resin layer 230. The refractive layer 235 may be formed to be adhered to at least the first light emitting surface 212a, and may be formed to completely cover the first light source 212 and to be in close contact with the reflective sheet 220.

In addition, the resin layer 230 is formed to be in close contact with the refractive layer 235 to surround the refractive layer 235.

The refractive layer 235 is formed of a light transmissive material and is formed of a material having a refractive index larger than that of the resin layer 230. Therefore, since the light emitted from the first light source 212 is refracted laterally in the refraction layer 235, the light emitted from the first light source 212 may be spread more widely.

The refractive layer 235 may be formed by applying a liquid or a gel-like resin on the light source 212 and curing it, or may be separately manufactured and adhered to the light emitting unit 210.

In addition, the refractive layer 235 may be formed to surround not only the first light source 212 but also the second light source 212.

Hereinafter, a backlight unit according to an eighth embodiment of the present invention will be described with reference to the drawings. However, the eighth embodiment is different from the first embodiment in that a light shielding sheet is provided. Therefore, the eighth embodiment is mainly described for the difference, and the description and reference numerals of the first embodiment are used for the same parts.

FIG. 13 is a partial cross-sectional view of a backlight unit according to an eighth embodiment of the present invention, and FIG. 14 is a partial perspective view schematically illustrating the light blocking sheet of FIG. 13.

13 and 14, the backlight unit according to the eighth embodiment of the present invention is provided with a light blocking sheet 270 that can block a part of the light emitted from the light sources 212 and 213.

The light blocking sheet 270 is formed of a transparent material, and may be disposed between the resin layer 230 and the optical sheet 250. In this case, each surface of the light blocking sheet 270 may be attached to the resin layer 230 and the optical sheet 250.

The light blocking sheet 270 has a first light blocking pattern 271 formed to correspond to the position of the first light source 212 and a second light blocking pattern 273 formed to correspond to the position of the second light source 213. This includes. The first light blocking pattern 271 may be printed on the light blocking sheet 270 directly above the first light source 212, and its size may vary according to the intensity of light emitted from the first light source 212. Can be adjusted. In addition, the second light blocking pattern 273 may be printed directly above the second light source 213, and may be formed in an elliptic shape along the extending direction of the second light source 213. The light blocking patterns 271 and 273 may be formed of titanium dioxide (TiO 2). In this case, part of the light incident from the light sources 212 and 213 may be reflected downward, and some of the light may be transmitted. .

The light blocking patterns 271 and 273 are formed to have a predetermined opacity to reduce the luminance of light emitted from the light sources 212 and 213. Since the luminance directly above the light sources 212 and 213 is greater than that of the surroundings, the light blocking patterns 271 and 273 having a predetermined opacity are formed directly above the light sources 212 and 213 to lower the luminance. In addition, the backlight unit 200 may be implemented to have a uniform brightness as a whole. The opacity of the light blocking patterns 271 and 273 is adjusted according to the light intensity of the light source 212.

The light blocking sheet 270 may be disposed between the optical sheet 250 and the display panel 300. In this case, part of the diffused and condensed light may not be transmitted while passing through the optical sheet 250, and thus brightness may be directly adjusted.

In addition, the light blocking sheet 270 may be disposed between the diffusion sheet and the prism sheet or between the prism sheet and the protective sheet.

Meanwhile, the light blocking patterns 271 and 273 may not be formed on the light blocking sheet 270 provided separately, but may be directly printed on the bottom or top surface of the optical sheet 500. In this case, the light quality may be further improved without changing the thickness of the backlight unit 200.

Hereinafter, a backlight unit according to a ninth embodiment of the present invention will be described with reference to the drawings. However, since the ninth embodiment differs in that the heat dissipation hole and the heat dissipation film are provided in comparison with the first embodiment, the differences will be mainly described. .

15 is a partial cross-sectional view of a backlight unit according to a ninth embodiment of the present invention.

Referring to FIG. 15, a heat dissipation hole 216 for heat dissipation is formed in the substrate 211 of the backlight unit according to the ninth embodiment of the present invention under the light sources 212 and 213. The heat dissipation hole 216 is formed so that heat generated from the light sources 212 and 213 can be smoothly discharged to the rear side of the cover 100 and is formed to correspond to the position of the lead electrode of the LED chip. Can be.

In addition, a heat radiation film 215 may be provided on the rear surface of the substrate 211 to improve heat radiation efficiency. The heat dissipation film 215 may be attached to each of the light emitting units 210, and the heat dissipation film 215 may be attached to the cover 210 first, and then the light emitting unit 210 may be attached.

On the other hand, the connection hole 110 formed in the cover 100 may be formed to increase the contact area with the air to increase the heat transfer efficiency due to convection. For example, the connection hole 110 may be formed to a size such that a position corresponding to the light sources 212 and 213 where heat is concentrated is exposed to air.

In this case, the heat dissipation film 215 may be a carbon nanotube (CNT) heat dissipation film, and the heat dissipation hole 216 may be filled with a thermally conductive filler.

By such a structure, even when the light sources 212 and 213 are surrounded by the resin layer 230, the heat radiation from the backlight unit 200 may be smoothly performed.

16 is a partial perspective view illustrating another arrangement of the light emitting unit of FIG. 3.

Referring to FIG. 16, the light emitting unit 210 includes a substrate 217 formed over the entire area of the backlight unit 200, and a plurality of first lights disposed on the substrate 217 and emitting light upward. A light source 218 and at least one second light source 219 disposed around the first light source 219 and emitting light laterally are included.

The light sources 218 and 219 may be controlled as a group that can be independently controlled around each first light source 218. That is, the controller 500 to be described later may independently control a plurality of light source groups formed on the substrate 217 to adjust the contrast of light supplied from the backlight unit 200 to the display panel 300. .

The arrangement of the first light source 218 and the second light source 219 is just an example, and the first light source 218 may be arranged around the second light source 219, Various embodiments may be changed, added, or deleted within the scope of the spirit of the present invention, such that the first light source 218 of the plurality of second light sources 219 may be disposed to surround the first light source 218.

17 is a cross-sectional view schematically illustrating a configuration of a display apparatus according to an embodiment of the present invention.

Referring to FIG. 17, the backlight unit 200 and the display panel 300 are provided in close contact with each other. As described above, an adhesive layer may be further provided between the backlight unit 200 and the display panel 300.

The backlight unit 200 may be attached to a lower side of the display panel 300, in detail, a lower side of the lower polarizer 310. The surface contacting the display panel 300 may be the resin layer 230 or the optical sheet 250.

The display module 20 including the backlight unit 200 and the display panel 300 may be attached and fixed to the front cover 11, and the back cover 12 may be attached to the front cover 11. ) May be fixed to a fastening member (not shown) such as a bolt.

In addition, the display apparatus 1 includes a power supply unit 400 for supplying power to the backlight unit 200 and the display panel 300, and the backlight unit 200 and the display panel 300. The control unit 500 for controlling the driving of a. For example, the controller 500 may be a timing controller.

The timing controller controls the driving timing of the display panel 300. In particular, the timing controller generates a signal for controlling the driving timing of the data driver, the gamma voltage generator, and the gate driver of the display panel 300. The display panel 300 may be transferred to the display panel 300. In addition, the timing controller may transmit a signal for controlling the driving timing of the light emitting unit 210 to the backlight unit 200.

The power supply unit 400 and the control unit 500 may be electrically connected to the connector 213 to supply power to the backlight unit 200 or to control the backlight unit 200.

Meanwhile, the power supply unit 400 and the control unit 500 are mounted to the back cover 12. In detail, the backlight unit 200 may be provided in the form of a thin film and is adhesively fixed to the display panel 300. The backlight unit 200 may be spaced apart from the display panel 300. In order to prevent this problem, at least one of the power supply unit 400 and the control unit 500 is mounted to the back cover 12 for stable and secure fixing. Preferably, both the power supply unit 400 and the control unit 500 may be mounted to the back cover 12.

The back cover 12 may be formed to be spaced apart from the rear surface of the backlight unit 200 by a predetermined distance, and the power supply unit 400 and the control unit 500 may include the backlight unit 200 and the back cover. It may be provided in the space between (12). In this case, since the distance between the power supply unit 400 and the connector 213 exposed on the back surface of the backlight unit 200 from the control unit 500 may be minimized, the arrangement of the conductors may be simplified. There is an advantage.

The scope of the present invention is not limited to the above-described embodiments, and the embodiments may be changed, added, or deleted within the scope of the spirit of the present invention.

1 is an exploded perspective view schematically showing the configuration of a display device including a backlight unit according to a first embodiment of the present invention.

2 is a partial cross-sectional view of the display module of FIG.

3 is a partial cross-sectional view showing the configuration of the backlight unit of FIG.

4 is a partial perspective view showing the arrangement of the light emitting unit of FIG. 3.

5 is a partial plan view of the backlight unit of FIG. 3;

6 is a partial cross-sectional view of the backlight unit of FIG. 3.

7 is a partial plan view of a backlight unit according to a second embodiment of the present invention;

8 is a partial plan view of a backlight unit according to a third embodiment of the present invention;

9 is a partial cross-sectional view of the backlight unit according to the fourth embodiment of the present invention.

10 is a partial cross-sectional view of the backlight unit according to the fifth embodiment of the present invention.

11 is a partial cross-sectional view of a backlight unit according to a sixth embodiment of the present invention.

12 is a partial sectional view of a backlight unit according to a seventh embodiment of the present invention;

13 is a partial sectional view of a backlight unit according to an eighth embodiment of the present invention;

14 is a partial perspective view schematically illustrating the light blocking sheet of FIG. 13.

15 is a partial sectional view of a backlight unit according to a ninth embodiment of the present invention;

FIG. 16 is a partial perspective view showing another arrangement of the light emitting unit of FIG. 3. FIG.

17 is a cross-sectional view schematically showing a configuration of a display device according to an embodiment of the present invention.

Claims (24)

A light emitting unit which emits light and is arranged to be adjacent to each other; And A resin layer is formed to cover the upper surface of the light emitting unit, In the light emitting unit, Board; A first light source disposed in the center of the substrate and emitting upward; And The backlight unit is disposed around the first light source, and includes at least one second light source that emits toward the side. The method of claim 1, And the second light source is disposed at a vertex or corner of a polygon with respect to the first light source. The method of claim 1, The light emitted from the second light sources adjacent to each other overlap each other, At least a portion of the overlapping area overlaps with the light emitted from the first light source. The method of claim 1, And a reflective sheet is attached to the substrate. The method of claim 4, wherein The reflective sheet is attached to the outside of the second light source. The method of claim 1, And a portion of the light emitted from the first light source and a portion of the light emitted from the second light source overlap each other. The method of claim 1, The first light source and the second light source is a backlight unit, characterized in that any one of a light emitting diode chip or a light emitting diode package equipped with at least one light emitting diode chip. The method of claim 1, The backlight unit, characterized in that a plurality of grooves are engraved on the upper portion of the resin layer. The method of claim 8, The refractive index of the resin layer is a backlight unit, characterized in that 1.4. The method of claim 1, And a connector for supplying power to the light source is formed on a rear surface of the substrate. The method of claim 10, The cover is in close contact with the back of the substrate to form a back of the backlight unit, And a connection hole is formed in the cover to expose the connector. The method of claim 1, An optical sheet in close contact with the resin layer is further included, And a light blocking sheet on which a light shielding pattern is printed at a position corresponding to the first light source or the second light source is provided on an upper surface or a lower surface of the optical sheet. The method of claim 1, And a heat dissipation film is provided on the back of the substrate. The method of claim 1, The resin unit is a backlight unit, characterized in that a plurality of scattering units or a plurality of bubbles of various sizes are formed. The method of claim 1, The light emitting unit further includes a refractive layer surrounding the first light source or the second light source and having a refractive index greater than that of the resin layer. The resin layer is formed so as to surround the refractive layer. The method of claim 1, The distance from the first light source to the edge of the substrate is a backlight unit, characterized in that 10mm to 25mm. The method of claim 1, The distance between the first light source and the second light source is a backlight unit, characterized in that 1mm to 5mm. Board; A plurality of first light sources disposed on the substrate and configured to emit light upward; At least one second light source disposed around each of the first light sources and emitting toward the side; And And a resin layer formed to surround the first light source and the second light source. The method of claim 18, And a light emitted from the first light source and a light emitted from the second light source overlap each other. The method of claim 18, One first light source and a second light source around the one first light source are And a second light source independently of the other first light source and a second light source surrounding the first light source. A display module comprising a backlight unit of any one of claims 1 to 20 and a display panel disposed in front of the backlight unit; A front cover to which the display module is fixed; And A back cover covering a rear surface of the display module is included; The backlight unit is in close contact with the display panel. The method of claim 21, The display panel, A thin film transistor substrate and a color filter substrate; A liquid crystal layer provided between the thin film transistor substrate and the color filter substrate; An upper polarizer provided on the color filter substrate; And A lower polarizer provided under the thin film transistor substrate, And the backlight unit is in close contact with the lower polarizer. The method of claim 21, A power supply unit supplying power to the display module; And A control unit for controlling the driving of the display module is further included. At least one of the power supply unit and the control unit is fixed to the back cover. The method of claim 23, And at least one of the power supply unit and the control unit is disposed in a space between a rear surface of the display module and the back cover.

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