Display apparatus

Disclosed herein is a display apparatus. The display apparatus includes a backlight unit configured to emit light, a display panel positioned in front of the backlight unit; and an optical film positioned in front of the display panel, and the optical film includes a base layer, a first refractive layer positioned in front of the base layer, a second refractive layer positioned in front of the first refractive layer and having a lower refractive index than the first refractive layer, a third refractive layer positioned at the rear of the base layer, and a fourth refractive layer positioned at the rear of the third refractive layer and having a lower refractive index than the third refractive layer.

CROSS-REFERENCE TO RELATED APPLICATION(S)

BACKGROUND

The disclosure relates to a display apparatus, and more particularly to a display apparatus including an optical film.

2. Description of Related Art

A display apparatus is a type of output device that visually displays data information such as characters and graphics, and images.

The display apparatus may include a self-emissive type display panel such as an organic light emitting diode (OLED) panel, or a non-self-emissive type display panel such as a liquid crystal display (LCD) panel.

A display apparatus having a liquid crystal display may include an optical film to improve a viewing angle. The optical film may include a plurality of refractive layers having different refractive indices. The optical film may improve the viewing angle of the display apparatus by utilizing the refraction phenomenon of light based on the refractive index difference among the plurality of refractive layers.

However, there is a limit in improving the viewing angle of a display apparatus using only an optical film that utilizes a refraction phenomenon of light caused by a refractive index difference among the plurality of refractive layers. When a material capable of maximizing the refractive index is used, the manufacturing cost of the optical film is increased.

SUMMARY

Therefore, it is an aspect of the present disclosure to provide a display apparatus having an improved viewing angle.

It is another aspect of the present disclosure to provide a display apparatus capable of reducing reflection of external light.

It is another aspect of the present disclosure to provide a display apparatus having an improved contrast ratio.

It is another aspect of the present disclosure to provide a display apparatus capable of simplifying a manufacturing process of an optical film.

It is another aspect of the present disclosure to provide a display apparatus capable of easily processing an optical film.

In accordance with an aspect of the disclosure, a display apparatus includes a backlight unit configured to emit light, a display panel positioned to the front of the backlight unit, and an optical film positioned to the front of the display panel, and the optical film includes a base layer, a first refractive layer positioned to the front of the base layer, a second refractive layer positioned to the front of the first refractive layer and having a lower refractive index than the first refractive layer, a third refractive layer positioned to the rear of the base layer, and a fourth refractive layer positioned to the rear of the third refractive layer and having a lower refractive index than the third refractive layer.

The first refractive layer may include first patterns that each include a first inclined portion configured to totally reflect some beams of the light emitted from the backlight unit.

The second refractive layer may include a first filling portion filling between the first patterns of the first refractive layer.

The third refractive layer may include second patterns that each include a second inclined portion configured to refract at least a part of the light emitted from the backlight unit that passes through the fourth refractive layer.

The first inclined portion may have a greater inclination angle than the second inclined portion.

The first pattern may have a higher height than the second pattern.

The fourth refractive layer may include a second filling portion filling between the second patterns of the third refractive layer.

The first patterns and the second patterns may be embossed patterns.

A distance between the first patterns may be different from a distance between the second patterns.

Each of the first patterns may include a parallel portion extending parallel to a direction in which the first refractive layer extends.

The first refractive layer may include a pattern including a curved portion configured to totally reflect a portion of the light emitted from the backlight unit.

The third refractive layer may include a pattern including a curved portion configured to refract at least a portion of the light emitted from the backlight unit that passes through the fourth refractive layer.

The pattern may be an engraved pattern.

In accordance with another aspect of the disclosure, a display apparatus includes a display panel, and an optical film positioned to the front of the display panel, and the optical film includes a base layer, a first refractive layer positioned to the front of the base layer and including first patterns each including a first inclined portion configured to totally reflect a portion of light passing through the base layer, a second refractive layer positioned to the front of the first refractive layer and having a lower refractive index than the first refractive layer, a third refractive layer positioned to the rear of the base layer and including second patterns each including a second inclined portion configured to refract a portion of light incident from the display panel, and a fourth refractive layer positioned to the rear of the third refractive layer and having a lower refractive index than the third refractive layer.

The first patterns may be embossed patterns and the second refractive layer may include a first filling portion filling between the first patterns.

The second patterns may be embossed patterns or engraved patterns, and the fourth refractive layer may include a second filling portion filling between the second patterns.

The first inclined portion may have a greater inclination angle than the second inclined portion.

The first pattern may have a higher height than the second pattern.

A distance between the first patterns may be different from a distance between the second patterns.

In accordance with another aspect of the disclosure, a display apparatus includes a display panel, and an optical film positioned to the front of the display panel and the optical film includes a base layer, a first refractive layer positioned to the front of the base layer, and including first patterns each including a first inclined portion configured to totally reflect a portion of light passing through the base layer, a second refractive layer positioned to the front of the first refractive layer and having a lower refractive index than the first refractive layer, the second refractive layer including a first filling portion filling between the first patterns, a third refractive layer positioned to the rear of the base layer and including second patterns each including a second inclined portion having a less inclination angle than the first inclined portion, and a fourth refractive layer positioned to the rear of the third refractive layer and having a lower refractive index than the third refractive layer, the fourth refractive layer including a second filling portion filling between the second patterns.

DETAILED DESCRIPTION

In the following description, like reference numerals refer to like elements throughout the specification. Well-known functions or constructions are not described in detail since they would obscure the one or more exemplar embodiments with unnecessary detail.

It will be understood that when an element is referred to as being “connected” another element, it can be directly or indirectly connected to the other element, wherein the indirect connection includes “connection via a wireless communication network”.

Throughout the description, when a member is “on” another member, this includes not only when the member is in contact with the other member, but also when there is another member between the two members.

An identification code is used for the convenience of the description but is not intended to illustrate the order of each step. The each step may be implemented in the order different from the illustrated order unless the context clearly indicates otherwise.

Reference will now be made in detail to embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings.

FIG. 1is a view of a display apparatus according to an embodiment of the disclosure.FIG. 2is an exploded view of the display apparatus shown inFIG. 1.

Referring toFIGS. 1 and 2, according to an embodiment of the disclosure, a display apparatus1includes a top chassis10, a display panel20, a backlight unit60, and a bottom chassis70. The top chassis10is positioned in front of the display panel20. The display panel20may be positioned in front of the backlight unit60. The backlight unit60is positioned behind the display panel20to be apart from the display panel20. The bottom chassis70may be positioned behind the display panel20and the backlight unit60.

A middle mold40may be further provided between the display panel20and the backlight unit60. The middle mold40may allow the display panel20to be supported apart from the backlight unit60. A controller81configured to control a drive of the display apparatus1may be positioned behind the bottom chassis70. A rear cover15forming a rear outer appearance of the display apparatus1may be provided behind the controller81.

A plurality of optical sheets30may be provided at the rear of the display panel20. A light guide plate50may be positioned at the rear of the optical sheet30. A reflective sheet55may be positioned behind the light guide plate50.

The optical sheet30includes a protective film31, a prism film32, and a diffusion film33. The protective film31is positioned in front of the prism film32to protect the prism film32sensitive to scratches such as dust.

A triangular prism may be positioned in front of the prism film32. Through the prim film32, light diffused by the diffusion film33may be focused on in a direction perpendicular to a rear surface of the display panel20. Two prism films32may be used. The light passing through the prism film32may travel perpendicularly to the display panel20so as to allow the display panel20to have a uniform brightness. Light passing through the light guide plate50may be diffused by the diffusion film33and supplied to the display panel20.

The light guide plate50may be configured to allow light emitted from a light emitting diode61to be uniformly supplied to the diffusion film33. The light guide plate50may include an exit surface51and an incident surface52. The exit surface51may be located behind the diffusion film33and face one surface of the diffusion film33. The incident surface52may be provided on the side surface to allow light emitted from the light emitting diode61to be incident thereon.

The reflective sheet55may be positioned behind the light guide plate50. Light emitted through a lower surface of the light guide plate50may be guided to the light guide plate50again by the reflective sheet55.

The backlight unit60includes a plurality of light emitting diodes61and a printed circuit board62. The backlight unit60may be configured to emit light. The light emitting diode61may supply light to the light guide plate50. The plurality of light emitting diodes61may be mounted on the printed circuit board62.

The plurality of light emitting diodes61may be mounted to protrude from one surface of the printed circuit board62. The plurality of light emitting diodes61may be arranged on a surface of the printed circuit board62at a predetermined distance.

The printed circuit board62may be positioned behind the reflective sheet55. The printed circuit board62may be fixed to the bottom chassis70via a fastening member such as a screw or an attachment means such as a double-sided tape. As for the printed circuit board62, a back surface of a surface on which the plurality of light emitting diodes61are mounted, may be fixed to a bottom surface72of the bottom chassis70.

The display panel20may include a first substrate21bincluding a thin film transistor (TFT) and a pixel electrode, and a second substrate21apositioned on one side of the first substrate21band provided with a color filter and a driving source. A liquid crystal layer21cmay be provided between the first substrate21band the second substrate21a. Polarizing sheets22and23may be attached to the rear of the first substrate21band/or the front of the second substrate21a. A module in which the first substrate21b, the second substrate21a, and the liquid crystal layer21care combined may be referred to as a liquid crystal display module21.

A driver25applying a driving signal may be provided on one side of the first substrate21b. The driver25may include a flexible printed circuit board26, a driving chip27, and a circuit board28. The driving chip27may be mounted on one side of the flexible printed circuit board26. The circuit board28may be connected to the other side of the flexible printed circuit board26.

A black matrix (not shown) may be formed on the second substrate21a. A cable to which the driver25and the controller81are connected may pass through the rear space of the black matrix.

The display panel20may form a screen by adjusting the arrangement of the liquid crystal layer21c. As a non-light emitting element, the display panel20may receive light from the backlight unit60and display an image.

An optical film100improving a viewing angle and/or a contrast ratio may be positioned in front of the display panel20. Details of the optical film100will be described later.

The top chassis10may include a bezel11and a top lateral side12. The bezel11may cover the front edge of the display panel20. The top lateral side12may be bent downward from an end portion of the bezel11. At least a part of the top lateral side12may be in contact with the bottom chassis70. For example, at least one part of the top lateral side12may cover the outer side of a bottom lateral side71.

The top chassis10may be provided with an opening13through which the display panel20is exposed. An effective display area, in which a screen is actually displayed on the display panel20, may be exposed to the front side through the opening13.

The bottom chassis70may include the bottom lateral side71and the bottom surface72. The bottom lateral side71may extend upwardly along the circumference of the bottom surface72. The backlight unit60may be seated on the bottom surface72. A heat radiation sheet (not shown) may be positioned behind the bottom surface72of the bottom chassis70.

The middle mold40may include a first support40a, a second support40b, and an extension portion40c. The first support40aand the second support40bmay extend to the inside of the middle mold40. The second support40bmay extend inward from the first support40aand extend downward from the first support40ato be stepped. The extension portion40cextends to the lower side of the middle mold40. A part of the display panel20may be supported by the first support40a. A part of the optical sheet30may be supported by the second support40b. An outer surface of the extension portion40cmay be in contact with the inner surface of the bottom chassis70.

The light emitting diode61may simultaneously emit light and heat. The printed circuit board62may serve not only to supply a driving signal to the light emitting diode61but also to transmit the heat generated by the light emitting diode61to the outside. That is, the heat generated in the light emitting diode61may be transmitted to the bottom chassis70through the printed circuit board62. The printed circuit board62may be formed of a metal having a high thermal conductivity to increase heat transfer efficiency. For example, the printed circuit board62may be formed of a metal material including aluminum or copper.

A controller81may be mounted on the rear side of the bottom chassis70. The rear cover15may be located behind the controller81. The controller81may include a substrate and a plurality of electronic components mounted on the substrate. The electronic components may be mounted on the upper surface and/or the lower surface of the substrate. The plurality of electronic components may be mounted on or fixed to the substrate by a clamp.

FIG. 3is a cross-sectional view schematically illustrating an optical film shown inFIG. 2.FIG. 4is a view schematically illustrating a state in which light, which is incident on the optical film shown inFIG. 3, is refracted.FIG. 5is a graph illustrating the distribution of light emitted from a backlight unit shown inFIG. 2.

Referring toFIG. 3, the optical film100may include a base layer101, a first refractive layer110, a second refractive layer120, a third refractive layer130and a fourth refractive layer140. The first refractive layer110and the third refractive layer130may be provided as a high refractive layer110and130and the second refractive layer120and the fourth refractive layer140may be provided as a low refractive layer120and140.

The base layer101may be positioned in front of the display panel20. The base layer101may be positioned in front of the polarizing sheet22of the display panel20. The base layer101may be arranged between the first refractive layer110and the third refractive layer130.

The base layer101may extend along a plane perpendicular to the front and rear direction. Light passing through the display panel20may pass through the base layer101.

The first refractive layer110may be positioned in front of the base layer101. The first refractive layer110may extend along a plane perpendicular to the front and rear direction. The first refractive layer110may include a first body layer111and a first pattern112formed on the first body layer111. The first pattern112may protrude from the first body layer111toward the front side.

A plurality of the first patterns112may be continuously formed in the first refractive layer110. The first pattern112may continuously protrude on the first body layer111. The first pattern112may be formed in an embossed pattern. The plurality of the first patterns112may be arranged at a first distance d1. The first pattern112may be formed to have a first height h1.

The first pattern112of the first refractive layer110may include a first inclined portion113. The first inclined portion113may be configured to totally reflect some beams of light beams emitted from the backlight unit60. The first inclined portion113may be configured to totally reflect some beams of light beams passing through the base layer101. The first inclined portion113may be configured to totally reflect light beams incident in the front and rear direction among the light beams emitted from the backlight unit60. The first inclined portion113may be configured to totally reflect some beams, which are obliquely incident with respect to the front and rear direction, among light beams passing through the third refractive layer130and the fourth refractive layer140. The first inclined portion113may be provided in plural. The first inclined portion113may be formed in a straight line.

The first inclined portion113may be formed to be inclined with respect to a direction in which the first refractive layer110extends. The first inclined portion113may be formed to allow light, which is incident on the first refractive layer110in the front and rear direction, to have an incident angle, which is greater than a critical angle. The first inclined portion113may form opposite sides of the first pattern112with respect to the front and rear direction.

The first pattern112of the first refractive layer110may include a first parallel portion114extending in the same direction as the direction in which the first refractive layer110extends. The first parallel portion114may extend in a direction perpendicular to the front and rear direction. The first parallel portion114may be provided between the plurality of the first inclined portions113. Accordingly, the first pattern112may have an approximately trapezoidal shape.

The first refractive layer110may include a second parallel portion115arranged between the plurality of the first patterns112. The second parallel portion115may be formed at a first distance d1 at which the first patterns112are spaced apart from each other. The first inclined portion113and the second parallel portion115may form a space in which a first filling portion121of the second refractive layer120is arranged.

The second refractive layer120may be positioned in front of the first refractive layer110. The second refractive layer120may have a lower refractive index than the refractive index of the first refractive layer110. Because the second refractive layer120has a refractive index different from the first refractive layer110, light beams passing sequentially through the first refractive layer110and the second refractive layer120may be totally reflected or refracted. The second refractive layer120may have a higher refractive index than the outer air layer.

The second refractive layer120may include the first filling portion121filling among the plurality of the first patterns112. The first filling portion121may be positioned in a space between the first patterns112. The first filling portion121may be formed to correspond to the size and shape of the space between the first patterns112. The first filling portion121may be in contact with the first inclined portion113. The first filling portion121may have the first height h1.

The third refractive layer130may be positioned at the rear of the base layer101. The third refractive layer130may have a refractive index similar to that of the first refractive layer110. The first refractive layer110and the third refractive layer130may be formed as a high refractive layer. The third refractive layer130may include a second body layer131and a second pattern132formed on the second body layer131. The second pattern132may protrude rearward from the second body layer131.

A plurality of second patterns132may be continuously formed on the third refractive layer130. The second pattern132may continuously protrude on the second body layer131. The second pattern132may be formed in an embossed pattern. The plurality of the second patterns132may be arranged at a second distance d2. The second distance d2 may be different from the first distance d1. The second distance d2 may be smaller than the first distance d1. The second pattern132may have a second height h2. The second height h2 may be different from the first height h1. The second height h2 may be smaller than the first height h1.

That is, because the size of the second pattern132is different from the size of the first pattern112, the second pattern132may refract light, which is incident in the front and rear direction, in various directions and emit the light.

The second pattern132of the third refractive layer130may include a second inclined portion133. The second inclined portion133may be configured to refract some beams of light beams emitted from the backlight unit60. The second inclined portion133may be configured to refract some beams of the light beams passing through the fourth refractive layer140. The second inclined portion133may be configured to refract some beams incident in the front and rear direction among the light beams emitted from the backlight unit60. The second inclined portion133may be configured to refract some beams, which are obliquely incident with respect to the front and rear direction, among light beams passing through the fourth refractive layer140. The second inclined portion133may be provided in plural. The second inclined portion133may be formed in a straight line.

The second inclined portion133may be formed to be inclined with respect to a direction in which the third refractive layer130extends. The second inclined portion133may be formed to allow light, which is incident on the third refractive layer130in the front and rear direction, to have an incident angle, which is smaller than a critical angle. The second inclined portion133may have the inclination angle less than that of the first inclined portion113. The second inclined portion133may form opposite sides of the second pattern132with respect to the front and rear direction.

The second pattern132of the third refractive layer130may include a third parallel portion134extending in the same direction as the direction in which the third refractive layer130extends. The third parallel portion134may extend in a direction perpendicular to the front and rear direction. The third parallel portion134may be provided between the plurality of the second inclined portions133. Accordingly, the second inclined portion133may have an approximately trapezoidal shape.

The third refractive layer130may include a fourth parallel portion135arranged between the plurality of the second patterns132. The fourth parallel portion135may be formed at a second distance d1 at which the second patterns132are spaced apart from each other. The second inclined portion133and the fourth parallel portion135may form a space in which a second filling portion141of the fourth refractive layer140is arranged.

The fourth refractive layer140may be positioned at the rear of the third refractive layer130. The fourth refractive layer140may have a lower refractive index than the third refractive layer130. Because the fourth refractive layer140has a refractive index different from that of the third refractive layer130, light passing sequentially through the fourth refractive layer140and the third refractive layer130may be refracted. The fourth refractive layer140may be arranged in front of the display panel20. The fourth refractive layer140may be arranged in a front side of the polarizing sheet22.

The fourth refractive layer140may include a second filling portion141filling among the plurality of the second patterns132. The second filling portion141may be positioned in a space between the second patterns132. The second filling portion141may be formed to correspond to the size and shape of the space between the second patterns132. The second filling portion141may be in contact with the second inclined portion133. The second filling portion141may have the second height h2.

Referring toFIG. 4, the light emitted from the backlight unit60may have a high proportion of light emitted in the front and rear direction and include components of light emitted in an oblique direction with respect to the front and rear direction. The light emitted in the front and rear direction in the backlight unit60and the light emitted in the oblique direction with respect to the front and rear direction may be incident on the optical film100after passing through the display panel20.

Referring toFIG. 5, the light emitted from the backlight unit60is incident on the optical film100after passing through the display panel20. Some beams of the light beams passing through the fourth refractive layer140may be incident on the third refractive layer130and then refracted. Particularly, light beams, which are incident on the second inclined portion133of the third refractive layer130among the light beams passing through the fourth refractive layer140, may be refracted by the difference between the third refractive layer130and the fourth refractive layer140. On the other hand, light beams, which are incident on the third parallel portion134or the fourth parallel portion135of the third refractive layer130among the light beams passing through the fourth refractive layer140, may be incident on the third refractive layer130without the refraction.

The light passing through the third refractive layer130may sequentially pass through the base layer101and the first refractive layer110.

Light passing through the first refractive layer110may be incident on the second refractive layer120and totally reflected and/or refracted. Some beams of the light beams incident on the second refractive layer120may be incident on the first inclined portion113. The light incident on the first inclined portion113may be totally reflected by the first inclined portion113. The light totally reflected by the first inclined portion113may be refracted by passing through the first parallel portion114, and then emitted to the outside through the second refractive layer120. The light totally reflected by the first inclined portion113may be refracted by the first inclined portion113that faces to each other, and then emitted to the outside through the second refractive layer120. Because the outer is an air layer and has a lower refractive index than the second refractive layer120, the light may be refracted upon being emitted to the outside from the second refractive layer120. The light emitted to the outside after being totally reflected by the first inclined portion113may have a relatively large exit angle.

Some beams of the light beams incident on the second refractive layer120may be incident on the first parallel portion114or the second parallel portion115. The light that is obliquely incident on the first parallel portion114may be refracted by the first parallel portion114and then emitted to the outside. The light perpendicularly incident on the first parallel portion114may be emitted to the outside without refraction. The light that is obliquely incident on the second parallel portion115may be refracted by the second parallel portion115and then emitted to the outside or may be refracted again by passing through the first inclined portion113and/or the first parallel portion114and then emitted to the outside. Because the outer is an air layer and has a lower refractive index than the second refractive layer120, the light may be refracted upon being emitted to the outside from the second refractive layer120.

Because the display apparatus1according to an embodiment of the disclosure includes the optical film100having the above-described configuration, the display apparatus1may mix light beams, which are emitted at various angles from the backlight unit60, and emit the mixed light beams and thus it is possible to improve the viewing angle. That is, some beams of the light beams emitted from the backlight unit60may be firstly refracted by sequentially passing through the fourth refractive layer140and the third refractive layer130and then emitted at various angles. After that, the light may be secondarily totally reflected and/or refracted by the first refractive layer110and the second refractive layer120and then emitted to the outside at various angles. Further, other beams of the light beams emitted from the backlight unit60may be emitted in the front and rear direction by passing through the parallel portion114,115,134, and135. Accordingly, the display apparatus1may emit light in various directions, thereby improving the viewing angle.

As for the optical film100according to an embodiment, because the light is provided to the first refractive layer110after firstly being refracted by the third refractive layer130and the fourth refractive layer140, it is possible to make the first height h1 of the first pattern112, which is to totally reflect the light, relatively low and thus it is possible to easily process the first pattern112.

In addition, because the external light is incident on the first refractive layer110after passing through the second refractive layer120having a relatively low refractive index, it is possible to prevent retro reflection caused by total reflection and thus it is possible to reduce the glare caused by the external light.

FIG. 6is a graph illustrating the distribution of light emitted from a backlight unit according to another embodiment of the disclosure.

Hereinafter a description the same as those described inFIGS. 3 to 5will be omitted.

Referring toFIG. 6, as for light emitted from a backlight unit60, the proportion of light emitted in the front and rear direction may be very high. The backlight unit60may be configured to minimize an amount of light emitted in the oblique direction with respect to the front and rear direction and to maximize an amount of light in the front and rear direction. The backlight unit60may include a condensing film (not shown) for facilitating condensation.

When the display apparatus1includes the condensed backlight unit60, the light beams emitted from the backlight unit60are refracted by the third refractive layer130and the fourth refractive layer140, or totally reflected and/or refracted and emitted to the outside, as illustrated inFIG. 4.

FIG. 7is a flow chart illustrating a method of manufacturing the optical film shown inFIG. 2.

A method of manufacturing the optical film100according to an embodiment of the disclosure will be described with reference toFIG. 7.

Referring toFIG. 7, the first refractive layer110and the third refractive layer130are arranged on opposite surfaces of the base layer101, respectively. The first refractive layer110and the third refractive layer130are formed of a material having a relatively high refractive index. The first refractive layer110and the third refractive layer130may be attached to opposite surfaces of the base layer101, respectively.

Next, the base layer101, to which the high refractive layers110and130are attached on opposite surfaces thereof, is moved to a pattern forming apparatus. The patterns112and132are formed on the first refractive layer110and the third refractive layer130, respectively, in the pattern forming apparatus. The patterns112and132may be formed in an embossed pattern. Alternatively, the pattern may be formed in an engraved pattern.

The base layer101with the high refractive layers110and130, on which the pattern forming process is completed, may be moved to a filling device. The filling device fills the first refractive layer110with the second refractive layer120and fills the third refractive layer130with the fourth refractive layer140. The second refractive layer120has a refractive index lower than that of the first refractive layer110, and the fourth refractive layer140has a refractive index lower than that of the third refractive layer130.

By using a method of manufacturing the optical film100according to an embodiment, a process of forming a pattern on the high refractive layers110and130arranged on opposite surfaces of the base layer101is performed independently of a process of filling the high refractive layers110and130with the low refractive layers120and140, and thus it is possible to simplify the manufacturing process and to reduce the loss in comparison with a conventional method of manufacturing the optical film in which the high refractive layer and the low refractive layer are laminated alternately.

FIG. 8is a cross-sectional view schematically illustrating an optical film according to another embodiment of the disclosure.

Hereinafter a description the same as those described inFIGS. 3 to 5will be omitted.

Referring toFIG. 8, an optical film200according to another embodiment of the disclosure may include a base layer201, a first refractive layer210, and a second refractive layer220, a third refractive layer230, and a fourth refractive layer240.

The first refractive layer210having a refractive index higher than that of the second refractive layer120may be arranged on one surface of the base layer201and the third refractive layer230having a refractive index higher than that of the fourth refractive layer140may be arranged on the other surface of the base layer201.

The first refractive layer210may include a first body layer211, a first pattern212, a first inclined portion213, a first parallel portion214, and a second parallel portion215.

The first pattern212may have a lower height than the first pattern112shown inFIGS. 3 to 5. That is, a third height h3 may be lower than the first height h1 shown inFIGS. 3 to 5.

A plurality of first patterns212may be continuously arranged at a third distance d3.

The second refractive layer220may be arranged in front of the first refractive layer210. The second refractive layer220may include a first filling portion221filling between the first patterns212.

The third refractive layer230may include a second body layer231, a second pattern232, a second curved portion233, a third parallel portion234, and a fourth parallel portion235.

The second curved portion233of the second pattern232may be formed as a curved surface unlike the second inclined portion133of the second pattern132shown inFIGS. 3 to 5. The second curved portion233may be formed to refract light incident from the fourth refractive layer240.

A fourth height h4 of the second pattern232may be lower than the third height h3 of the first pattern212. The second pattern232may be formed in an embossed pattern.

A plurality of second patterns232may be continuously arranged at a fourth distance d4. The fourth distance d4 may be smaller than the third distance d3.

The fourth refractive layer240may be arranged at the rear of the third refractive layer230. The fourth refractive layer240may include a second filling portion241filling between the second patterns232.

By using the above-described configuration, the optical film200according to another embodiment of the disclosure may mix light beams, which are emitted at various angles from the backlight unit60, and emit the mixed light beams at various angles, and thus it is possible to improve the viewing angle of the display apparatus1.

FIG. 9is a cross-sectional view schematically illustrating an optical film according to yet another embodiment of the disclosure.

Hereinafter description of the same parts as those described above will be omitted.

Referring toFIG. 9, an optical film300according to another embodiment of the disclosure may include a base layer301, a first refractive layer310, a second refractive layer320, a third refractive layer330and a fourth refractive layer340.

The first refractive layer310having a refractive index higher than that of the second refractive layer320may be arranged on one surface of the base layer301and the third refractive layer330having a refractive index higher than that of the fourth refractive layer340may be arranged on the other surface of the base layer301.

The first refractive layer310may include a first body layer311, a first pattern312, a first inclined portion313, a first parallel portion314, and a second parallel portion315.

The first pattern312may have a fifth height h5. The fifth height h5 may be similar with the third height h3 shown inFIG. 8.

A plurality of first patterns312may be continuously arranged at a fifth distance d5. The fifth distance d5 may be similar with the third distance d3 shown inFIG. 8.

The second refractive layer320may include a first filling portion321filling between the first patterns312.

The third refractive layer330may include a second body layer331, a second pattern332, a second curved portion333, a third parallel portion334, and a fourth parallel portion335.

The second pattern332may be formed in an engraved pattern unlike the second pattern232shown inFIG. 8. The second pattern332may be a space filled by the second filling portion341of the fourth refractive layer340.

The second curved portion333of the second pattern332may be formed as a curved surface like the second curved portion233shown inFIG. 8. The second curved portion333may be formed to refract light incident from the fourth refractive layer340. A sixth height h6 of the second pattern332may be lower than the fifth height h5 of the first pattern312.

A plurality of second patterns332may be continuously arranged at a sixth distance d6. The sixth distance d6 may be less than the fifth distance d5.

The fourth refractive layer340may include a second filling portion341filling a space in which the second patterns332are formed.

By using the above-described configuration, the optical film300according to another embodiment of the disclosure may mix light beams, which are emitted at various angles from the backlight unit60, and emit the mixed light beams at various angles, and thus it is possible to improve the viewing angle of the display apparatus1.

FIG. 10is a cross-sectional view schematically illustrating an optical film according to yet another embodiment of the disclosure.

Hereinafter description of the same parts as those described above will be omitted.

Referring toFIG. 10, an optical film400according to another embodiment of the disclosure may include a base layer401, a first refractive layer410, a second refractive layer420, a third refractive layer430and a fourth refractive layer440.

The first refractive layer410having a refractive index higher than that of the second refractive layer420may be arranged on one surface of the base layer401and the third refractive layer430having a refractive index higher than that of the fourth refractive layer440may be arranged on the other surface of the base layer401.

The first refractive layer410may include a first body layer411, a first pattern412, a first curved portion413, a first parallel portion414, and a second parallel portion415.

The first pattern412may have a seventh height h7. A plurality of first patterns412may be continuously arranged at a seventh distance d7.

The first pattern412may include a first curved portion413formed in a curved surface, unlike the first pattern112shown inFIGS. 3 to 5and the first pattern212shown inFIG. 8. The first curved portion413may be configured to totally reflect some beams of light beams, which are emitted from the backlight unit60and incident on the first pattern412.

The second refractive layer420may include a first filling portion421filling between the first patterns412.

The third refractive layer430may include a second body layer431, a second pattern432, a second curved portion433, a third parallel portion434, and a fourth parallel portion435.

The second curved portion433of the second pattern432may be formed as a curved surface like the second curved portion233shown inFIG. 8. The second curved portion433may be formed to refract light incident from the fourth refractive layer440. An eighth height h8 of the second pattern432may be lower than the seventh height h7 of the first pattern412. The eighth height h8 of the second pattern432may be lower than the fourth height4as shown inFIG. 8.

A plurality of second patterns432may be continuously arranged at an eighth distance d8. The eighth distance d8 may be less than the seventh distance d7.

The fourth refractive layer440may include a second filling portion441filling a space between the second patterns432.

By using the above-described configuration, the optical film400according to another embodiment of the disclosure may mix light beams, which are emitted at various angles from the backlight unit60, and emit the mixed light beams at various angles, and thus it is possible to improve the viewing angle of the display apparatus1.

As is apparent from the above description, the display apparatus may refract some beams of incident light beams and then totally reflect the some beams, thereby improving the viewing angle.

The display apparatus may be configured to allow external light to be incident on a refractive layer having a relatively low refractive index and then to be moved to a refractive layer having a relatively high refractive index, and thus the display apparatus may prevent retro-reflection caused by total reflection and improve the contrast ratio.

The display apparatus may simplify a manufacturing process by performing processes in the following order; arranging a high refractive layer on a front side and a rear side of a base layer; forming a pattern on the high refractive layer, and filling a low refractive layer.

The display apparatus may form a pattern on a first refractive layer so that light, which is refracted by a third refractive layer and a fourth refractive layer, is totally reflected by the first refractive layer and a second refractive layer, and thus it is possible to easily form the pattern in comparison with a case in which the third refractive layer and the fourth refractive layer are omitted.