Patent Description:
Generally, flat display devices, such as a liquid crystal display device (LCD), a plasma display panel device (PDP), and an organic light emitting diode (OLED) display device, easily achieves high resolution and have various advantages as large-sized display devices.

The display device includes a display panel, which includes a plurality of pixels. The pixel includes sub-pixels displaying respective colors.

In detail, when the display panel is a liquid crystal display panel, it includes an array substrate, an upper substrate and a liquid crystal layer therebetween. The array substrate includes gate lines and data lines crossing each other to define sub-pixel regions, and a thin film transistor as a switching element in each sub-pixel region. The upper substrate includes a color filter and/or black matrix.

When the display panel is an organic light emitting diode display panel, it includes an array substrate and an upper protection substrate. The array substrate includes gate lines and data lines crossing each other to define sub-pixel regions, an organic light emitting diode in each sub-pixel region, and a thin film transistor as a switching element in each sub-pixel region to supply an electric signal to the organic light emitting diode.

<FIG> is a view illustrating an arrangement of sub-pixels of a display panel according to the related art.

Referring to <FIG>, the display panel <NUM> includes a plurality of pixels P to display a color image, and each pixel P includes a red sub-pixel Pr, a blue sub-pixel Pb and a green sub-pixel Pg.

Each sub-pixel includes an opening region Al and a non-opening region A2. The opening region Al is a region where a light is output from each sub-pixel, and the non-opening region A2 is a region where a light is not output from each sub-pixel.

The non-opening regions A2 are recognized as a lattice-like pattern by a viewer and becomes a cause of degradation of display quality.

However, there is a limit to reduction of the non-display regions A2 of the sub-pixels Pr, Pg and Pb because of process margin. Various researches have been conducted in order to reduce the lattice-like pattern, but a phenomenon of the image being unclear such as an image blur has happened. Accordingly, a solution to maintain a clear image and reduce a lattice-like pattern is required.

Particularly, when viewing a virtual reality (VR) device, a lattice-like pattern and an image blur are more recognized, and a solution for this is required.

<CIT> in an abstract states "The present invention provides a display device which can attain higher contrast than that of the conventional display device. The display device (<NUM>) comprises: an image light source (<NUM>); and an optical sheet (<NUM>) having a plurality of layers for controlling an incident light from the image light source and for outputting the light to the observer side, wherein the optical sheet comprises an optical functional sheet layer (<NUM>) in which light-transmissive portion(s) (<NUM>) configured to transmit light and light-absorbing portion(s) (<NUM>) configured to absorb light are alternately arranged along the sheet plane, and only one layer (<NUM>) or a plurality of layers of which refractive indices are substantially the same is (are) provided on the observer side of the optical functional sheet layer.

<CIT> in an abstract states "An object of the invention is to provide an optical collective substrate and a display device using it, which can make effective use of light while avoiding generation of chromatic aberration in transmitted light. An optical substrate ( <NUM> ) of an optically transmissive material having a structure in which incident light Li from one principal plane ( <NUM> ) side of the substrate is locally focused toward an array of apertures ( <NUM> ) formed on the other principal plane ( <NUM> ). The one principal plane ( <NUM> ) is provided with grooves <NUM> v being filled with an optically transmissive substance <NUM> of a predetermined refractive index, the filled groove portions <NUM> V allowing the incident light Li from the one principal plane ( <NUM> ) side to be collected onto the respective apertures ( <NUM> ).

<CIT> in an abstract states "To provide an anisotropic optical film which exhibits high linear transmittance in a non-diffusion region, and which, as a result of being provided with a broad diffusion region in the MD and TD directions, is capable of solving problems such as glare and the occurrence of abrupt changes in brightness. [Solution] Provided is an anisotropic optical film having, stacked therein, at least two anisotropic light-diffusion layers having linear transmittances which change in accordance with the angle of incident light. Each of the anisotropic light-diffusion layers is provided with a matrix region, and a plurality of columnar regions having refractive indices which are different to that of the matrix region. At least two kinds of anisotropic light-diffusion layers (a, b), in each of which the aspect ratios of the major axes to the minor axes of the columnar regions in a cross section orthogonal to the alignment direction are different to those of the other, are employed as the anisotropic light-diffusion layers. The aspect ratios of the major axes to the minor axes of the columnar regions in the anisotropic light-diffusion layer (a) are less than <NUM>. The aspect ratios of the major axes to the minor axes of the columnar regions in the anisotropic light-diffusion layer (b) are within the range <NUM>-<NUM> inclusive.

<CIT> in an abstract states "A liquid crystal display device of the present invention includes a liquid crystal display panel, and a light diffusing layer which has first and second major surfaces and which is arranged such that the first major surface opposes a viewer side surface of the liquid crystal display panel. The light diffusing layer includes a first region formed of a first substance which has a first refractive index N1 and a plurality of second regions formed of a second substance which has a second refractive index N2.

<CIT> in an abstract states "A light control film includes a light shielding layer and a light diffusion portion, and, when an area of a part where the light shielding layer is in contact with one surface of the base material is set to S1, and an area of a part where a low refractive index portion is exposed between light incidence end surfaces is set to S2, the light shielding layer and the light diffusion portion are formed so as to satisfy (S1-S2)/S1×<NUM>≧<NUM>.

<CIT> in an abstract states "The invention provides a display panel having high light-extraction efficiency which can be easily produced. The present invention provides a display panel including an emission layer having a light-emitting layer and a transparent member (transmission layer) having recesses, an inclined surface of the recesses acting as a total reflection surface to reflect part of light radiated from the light-emitting layer. The display panel changes the optical path by total reflection, thus having no light-absorption loss and having high light-extraction efficiency. Since there is no need to deposit a reflecting film, it is easy to produce. Thus, a high-intensity display panel can be provided at low cost.

Accordingly, the present disclosure is directed to a display device that substantially obviates one or more of the problems due to limitations and disadvantages of the related art.

An object of the present disclosure is to provide a display device that can maintain a clear image and reduce recognition of a lattice-like pattern.

Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. These and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.

To achieve these and other advantages and in accordance with the purpose of the present disclosure, as embodied and broadly described herein, a display device includes a display panel as described in claims <NUM> to <NUM>.

In the drawings:.

The same reference numbers may be used throughout the drawings to refer to the same or like parts.

<FIG> is a schematic cross-sectional view illustrating a display device according to a first embodiment of the present invention.

Referring to <FIG>, the display device <NUM> includes a display panel <NUM>, and a light path adjustment film <NUM> on the display panel <NUM>.

The light path adjustment film <NUM> includes a first base film <NUM>, a second base film <NUM>, and a pattern layer <NUM> between the first and second base films <NUM> and <NUM>.

The second base film <NUM> may function to prevent scattering of an external light. Accordingly, when there is no influence of an external light (e.g., when an VR device is used), the second base film <NUM> may be eliminated from the display device <NUM>.

The first base film <NUM> supports the pattern layer <NUM>. The first base film <NUM> may contact the display panel <NUM> and protect the display panel <NUM> from a moisture or impact, and thus reliability can be achieved.

The pattern layer <NUM> may include a plurality of patterns <NUM> that have a first refractive index, and air gaps <NUM> that are between the patterns <NUM> and have a second refractive index less than the first refractive index. The air gap <NUM> is by way of example in this embodiment, and a material having a refractive index less than the first refractive index may be used.

Each of the first and second base films <NUM> and <NUM> may be made of a polyethylene terephthalate (PET), polycarbonate (PC), or acryl based material. The pattern layer <NUM> may be made of a polycarbonate (PC), or acryl based material.

The light path adjustment film <NUM> uses the pattern layer <NUM> to adjust a path of light from the display panel <NUM> in path and output the light.

<FIG> and <FIG> are views enlarging the pattern of the light path adjustment film according to the first embodiment of the present disclosure.

Referring to <FIG> and <FIG>, each pattern <NUM> of the pattern layer <NUM> may include a top surface that is spaced apart at a predetermined distance from the display panel <NUM> and parallel with the display panel <NUM>, a bottom surface that is between the top surface and the display panel <NUM>, and a slanted surface that connects the top surface and the bottom surface at a predetermined slanted angle. The pattern <NUM> may have, for example, a truncated quadrangular pyramid shape of <FIG>, or a truncated cone shape of <FIG>.

The pattern <NUM> may have other truncated polypyramid shape. In other words, the pattern <NUM> may be configured such that the top surface and the bottom surface of the pattern <NUM> are different in size to adjust a path of a light from the display panel <NUM>.

<FIG> is a schematic view illustrating an arrangement of the sub-pixels of the display panel according to the first embodiment of the present disclosure.

Referring to <FIG>, a pentile structure may be used in which a red sub-pixel R and a blue sub-pixel B may be alternately arranged in a same column, and green sub-pixels G may be arranged in a neighboring column. However, other structure and arrangement may be used. Each sub-pixel <NUM> includes an opening region 111a and a non-opening region 111b.

The opening region 111a is a region where light is output from each sub-pixel <NUM>, and the non-opening region 111b is a region where light is not output from each sub-pixel <NUM>.

The non-opening regions 111b are recognized as a lattice-like pattern by a viewer and becomes a cause of degradation of display quality. However, since the non-opening region 111b are regions where the gate and data lines and the thin film transistors to operate the sub-pixels <NUM> are formed, there is a limit to reduction of the non-display regions 111b because of process margin.

<FIG> is a schematic plan view illustrating the display device according to the first embodiment of the present disclosure.

Referring to <FIG>, in the sub-pixel arrangement of the pentile structure, the light path adjustment film <NUM> may be configured such that the patterns <NUM> of the truncated quadrangular pyramid shape correspond to the respective sub-pixels <NUM>. Each sub-pixel <NUM> includes the opening region 111a and the non-opening region 111b.

<FIG> is a schematic cross-sectional view taken along a line VI-VI of <FIG>.

Referring to <FIG>, the light path adjustment film <NUM> is located on the display panel <NUM>.

The light path adjustment film <NUM> may include the first base film <NUM>, the second base film <NUM>, and the pattern layer <NUM> between the first and second base films <NUM> and <NUM>.

The pattern layer <NUM> may include the plurality of patterns <NUM> and the plurality of air gaps <NUM>, and each pattern <NUM> may correspond to each sub-pixel <NUM>. In other words, a pattern is a region of a certain shape.

In detail, each pattern <NUM> may have a shape such that the pattern <NUM> includes a top surface that is spaced apart at a predetermined distance from the display panel <NUM> and parallel with the display panel <NUM>, a bottom surface that is between the top surface and the display panel <NUM>, and a slanted surface that connects the top surface and the bottom surface at a predetermined slanted angle.

In this case, the top surface of the pattern <NUM> has an area greater than that of the opening region 111a of the sub-pixel <NUM> to prevent reduction of brightness of the sub-pixel <NUM>. The bottom surface of the pattern <NUM> has an area greater than that of the top surface to adjust a light path by the slanted surface.

The area of the bottom surface of the pattern <NUM> is greater than the area of the opening region 111a and is equal to or less than the area of the sub-pixel <NUM>, and the bottom surfaces of the patterns <NUM> does not overlap each other. Accordingly, each pattern <NUM> is arranged to correspond to each sub-pixel <NUM>.

<FIG> is a schematic plan view illustrating another example of the display device according to the first embodiment of the present disclosure.

Referring to <FIG>, in the arrangement of the pixels <NUM> of the pentile structure, each pattern <NUM> of the light path adjustment film <NUM> may be arranged to correspond to each pixel <NUM>.

Each pixel <NUM> may include opening regions 113a outputting a light and non-opening regions 113b not outputting a light. Each opening region 113a of the pixel <NUM> may be formed at each sub-pixel region of the pixel <NUM>.

The non-opening regions 113b may include a second non-opening region 113b2 surrounding a peripheral portion of the opening regions 113a, and a first non-opening region 113b1 between the opening regions 113a.

<FIG> is a schematic cross-sectional view taken along a line VII-VII of <FIG>.

The pattern layer <NUM> may include the plurality of patterns <NUM> and the plurality of air gaps <NUM>, and each pattern <NUM> may correspond to each pixel <NUM>.

In this case, the top surface of the pattern <NUM> has an area greater than that of the opening regions 113a and the first non-opening region 113b1 of the pixel <NUM>, to prevent reduction of brightness of the pixel <NUM>. The bottom surface of the pattern <NUM> has an area greater than that of the top surface to adjust a light path by the slanted surface.

The area of the bottom surface of the pattern <NUM> is greater than the area of the opening regions 113a and the first non-opening region 113b1 of the pixel <NUM> and is equal to or less than the area of the pixel <NUM>, and the bottom surfaces of the patterns <NUM> do not overlap each other. Accordingly, each pattern <NUM> is arranged to correspond to each pixel <NUM>.

<FIG> is a view illustrating a light path through the light path adjustment film according to the first embodiment of the present invention.

Referring to <FIG>, light input through the first base film <NUM> is adjusted in path while passing through the pattern <NUM> of the pattern layer <NUM> then passes through the second base film <NUM> and then is output.

In detail, light, which is vertically input, from the opening region 111a of each sub-pixel <NUM>, to a center portion of the bottom surface of the pattern <NUM>, passes through the first base film <NUM>, the pattern <NUM> and the second base film <NUM> without refraction and then is output as it is (e.g., a light path (<NUM>)).

Light, which is input, from the opening region 111a of each sub-pixel <NUM>, to the slanted surface via the bottom surface of the pattern <NUM>, is totally reflected thus adjusted in path and is output to a region that corresponds to the non-opening region 111b of the sub-pixel <NUM> (e.g., a light path ②).

Light, which is input, from the opening region 111a of each sub-pixel <NUM>, to the slanted surface of the pattern <NUM>, is adjusted in path toward the second base film <NUM> because of a difference of refractive index between the air gap <NUM> and the pattern <NUM>, and is output to a region that corresponds to the non-opening region 111b of the sub-pixel <NUM> (e.g., a light path ③).

Accordingly, when light from each sub-pixel <NUM> pass through the light path adjustment film <NUM>, the light can be output to a region corresponding to the opening region 111a of the sub-pixel <NUM> and can also be adjusted in path and output to a region corresponding to the non-opening region 111b of the sub-pixel <NUM>. Thus, a lattice-like pattern can be reduced, and a clear image can be maintained.

<FIG> is a picture of the display device according to the first embodiment of the present invention. Explanations of parts similar to parts of the previous embodiment can be omitted.

Referring to <FIG>, since the display device <NUM> of this embodiment outputs lights from each sub-pixel <NUM> to regions corresponding to the opening region 111a and the non-opening region 111b of the sub-pixel <NUM> via the light path adjustment film <NUM>, it is seen that a clear image is produced and a lattice-like pattern is reduced.

<FIG> is a schematic cross-sectional view illustrating a light path adjustment film according to a second embodiment of the present disclosure.

Referring to <FIG>, the light path adjustment film <NUM> includes a first base film <NUM>, a second base film <NUM>, and a pattern layer <NUM> between the first and second base films <NUM> and <NUM>.

The second base film <NUM> may function to prevent scattering of an external light. Accordingly, when there is no influence of an external light (e.g., when an VR device is used), the second base film <NUM> may be eliminated from the display device.

The first base film <NUM> may contact the display panel (e.g., <NUM> of <FIG>) and protect the display panel from a moisture or impact, and thus reliability can be achieved.

The pattern layer <NUM> includes a plurality of patterns <NUM> that have a first refractive index, and air gaps <NUM> that are between the patterns <NUM> and have a second refractive index less than the first refractive index. The air gap <NUM> is by way of example in this embodiment, and a material having a refractive index less than the first refractive index may be used.

Each pattern <NUM> of the pattern layer <NUM> is formed such that the pattern <NUM> includes a top surface that is spaced apart at a predetermined distance from the display panel and parallel with the display panel, a bottom surface that is between the top surface and the display panel, and a slanted surface that connects the top surface and the bottom surface at a predetermined slanted angle.

In this embodiment, the bottom surfaces of the patterns <NUM> are spaced apart at a predetermined distance d from each other, differently than the first embodiment.

The top surface of the pattern <NUM> has an area greater than that of the opening region (e.g., 111a of <FIG>) of the sub-pixel (e. g, <NUM> of <FIG>) to prevent reduction of brightness of the sub-pixel. The bottom surface of the pattern <NUM> has an area greater than that of the top surface to adjust a light path by the slanted surface.

The area of the bottom surface of the pattern <NUM> is greater than the area of the opening region of the sub-pixel, and is less than the area of the sub-pixel in light of the distance d between the bottom surfaces.

<FIG> is a schematic cross-sectional view illustrating a light path adjustment film according to a third embodiment of the present invention. Explanations of parts similar to parts of the previous embodiments can be omitted.

Referring to <FIG>, each pattern <NUM> of the pattern layer <NUM> may has an inverted truncated polypyramid shape, for example, an inverted truncated quadrangular pyramid shape or inverted truncated cone shape, such that the pattern <NUM> includes a top surface that is spaced apart at a predetermined distance from the display panel (e.g., <NUM> of <FIG>) and parallel with the display panel, a bottom surface that is between the top surface and the display panel, and a slanted surface that connects the top surface and the bottom surface at a predetermined slanted angle.

In this embodiment, the bottom surface of the pattern <NUM> has an area greater than that of the opening region (e.g., 111a of <FIG>) of the sub-pixel (e. g, <NUM> of <FIG>) to prevent reduction of brightness of the sub-pixel. The top surface of the pattern <NUM> has an area greater than that of the bottom surface to adjust a light path by the slanted surface.

The area of the top surface of the pattern <NUM> is greater than the area of the opening region of the sub-pixel and is equal to or less than the area of the sub-pixel, and the top surfaces of the patterns <NUM> do not overlap each other.

In this embodiment, a light input through the first base film <NUM> is adjusted in path while passing through the pattern <NUM> of the pattern layer <NUM> then passes through the second base film <NUM> and then is output.

In detail, light, which is input, from the opening region (e.g., 111a of <FIG>) of each sub-pixel (e.g., <NUM> of <FIG>), to the bottom surface of the pattern <NUM>, passes through the first base film <NUM>, the pattern <NUM> and the second base film <NUM> without refraction and then is output as it is (e.g., a light path ①).

Light, which is input, from the opening region of each sub-pixel, to the slanted surface of the pattern <NUM>, is adjusted in path toward the second base film <NUM> because of a difference of refractive index between the air gap <NUM> and the pattern <NUM>, and is output to a region that corresponds to the non-opening region (e.g., 111b of <FIG>) of the sub-pixel (e.g., a light path ②).

Accordingly, when light from each sub-pixel passes through the light path adjustment film <NUM>, the light can be output to a region corresponding to the opening region of the sub-pixel and can also be adjusted in path and output to a region corresponding to the non-opening region of the sub-pixel. Thus, a lattice-like pattern can be reduced, and a clear image can be maintained.

Further, each pattern <NUM> may be arranged corresponding to each pixel (e.g., <NUM> of <FIG>).

The light path adjustment structure of this embodiment is a structure that effectively adjusts a light path by gently forming the slanted surface in case of manufacturing the light path adjustment film <NUM> in a thin film type.

<FIG> is a schematic view illustrating a display device according to a fourth embodiment of the present disclosure.

Referring to <FIG>, the display device <NUM> includes a display panel <NUM> that includes a plurality of pixels each having sub-pixels, and a light path adjustment film <NUM> on the display panel <NUM>.

The light path adjustment film <NUM> may include a plurality of first pattern portions <NUM> of a cylindrical shape that have a first refractive index, and a plurality of second pattern portions <NUM> that are between the first pattern portions <NUM> and have a second refractive index less than the first refractive index.

Alternatively, the light path adjustment film <NUM> may include a plurality of first pattern portions <NUM> of a cylindrical shape that have a first refractive index, and a plurality of second pattern portions <NUM> that are between the first pattern portions <NUM> and have a second refractive index greater than the first refractive index.

A case that the first refractive index of the first pattern portion <NUM> is greater than the second refractive index of the second pattern portion <NUM> is explained below.

The first pattern portion <NUM> has a cylindrical shape that has a size less than that of the sub-pixel. The cylindrical shape may have a diameter d of, for example, <NUM> or less.

The second pattern portion <NUM> is located between the first pattern portions <NUM>. The second pattern portion <NUM> may be continuous.

Accordingly, the light path adjustment film <NUM> includes the plurality of first pattern portions <NUM> of a cylindrical shape having the first refractive index, and the plurality of second pattern portions <NUM> that have the second refractive index less than the first refractive index of the first pattern portion <NUM> and arranged between the first pattern portions <NUM>.

The light path adjustment film <NUM> may be made of a polycarbonate (PC), or acryl based material.

The first pattern portion <NUM> may have a height of, for example, <NUM> or less.

The display device <NUM> can adjust a path of light from the display panel <NUM> using the light path adjustment film <NUM>.

<FIG> is a schematic plan view illustrating the display device according to the fourth embodiment of the present disclosure.

Referring to <FIG>, in the sub-pixel arrangement of the pentile structure, the light path adjustment film <NUM> is located on the sub-pixels <NUM>.

The plurality of first pattern portions <NUM> and the plurality of second pattern portions <NUM> are arranged to correspond to each sub-pixel <NUM>.

Each sub-pixel <NUM> includes an opening region 411a and a non-opening region 411b.

As described above, the diameter d of the first pattern portion <NUM> may be less than that of the sub-pixel <NUM>. The first pattern portions <NUM> may be arranged uniformly or non-uniformly.

Since the light path adjustment film <NUM> includes the first pattern portion <NUM> of a minute cylindrical shape, aligning between the opening region 411a of the sub-pixel <NUM> and the first pattern portion <NUM> of the light path adjustment film <NUM> is not needed. Thus, a manufacturing process can be simplified.

<FIG> is a cross-sectional view taken along a line XIV-XIV of <FIG>.

Referring to <FIG>, the light path adjustment film <NUM> is located on the sub-pixel <NUM>.

The light path adjustment film <NUM> includes the plurality of first pattern portions <NUM> and the plurality of second pattern portions <NUM> arranged on the sub-pixel <NUM>.

The first pattern portions <NUM> have a minute cylindrical shape, and the second pattern portions <NUM> of the second refractive index less that the first refractive index are arranged between the first pattern portions <NUM>.

The plurality of first pattern portions <NUM> and the plurality of second pattern portions <NUM> correspond to each sub-pixel <NUM>.

<FIG> is a view illustrating a light path through the light path adjustment film according to the fourth embodiment of the present invention.

Referring to <FIG>, the non-opening region 411b of the sub-pixel does not output light. Light from the opening region 411a is diffracted while passing through the minute first pattern portions <NUM> and thus light output range is expanded.

In other words, when the first pattern portion <NUM> has a minute width that is close to a wavelength of light, light output from the opening region 411a is diffracted while passing through the first pattern portion <NUM>, and a light output range is expanded.

When the width of the first pattern portion is greater than a wavelength of a light, light output from the opening region 411a may be refracted while passing through the first pattern portion <NUM> and thus light output range may be expanded.

In other words, light input to the first pattern portion <NUM> is mostly totally reflected and travels in the first pattern portion <NUM> because of a difference of a refractive index between the first pattern portion <NUM> and the second pattern portion <NUM>, and while passing through the first pattern portion <NUM>, the light is diffracted or refracted toward a side direction and thus a light output range may be expanded.

Accordingly, when light from each sub-pixel <NUM> passes through the light path adjustment film <NUM>, the light can be output to a region corresponding to the opening region 411a of the sub-pixel <NUM> and can also be adjusted in path and output to a region corresponding to the non-opening region 411b of the sub-pixel <NUM>. Thus, a lattice-like pattern can be reduced, and a clear image can be maintained.

<FIG> are views of other examples of light path adjustment films according to the fourth embodiment of the present disclosure.

Referring to <FIG>, a first base film <NUM> may be located at a bottom of the light path adjustment film <NUM>.

The first base film <NUM> supports the light path adjustment film <NUM>. The first base film <NUM> may contact the display panel <NUM> and protect the display panel <NUM> from a moisture or impact, and thus reliability can be achieved.

Referring to <FIG>, a second base film <NUM> may be located at a top of the light path adjustment film <NUM>.

Referring to <FIG>, the first base film <NUM> and the second base film <NUM> may be located at the bottom and the top of the light path adjustment film <NUM>.

Each of the first and second base films <NUM> and <NUM> may be made of a polyethylene terephthalate (PET), polycarbonate (PC), or acryl based material.

As described above, in the display device <NUM> of this embodiment, the light path adjustment film <NUM> including the minute-sized first pattern portions <NUM> and the second pattern portions <NUM> are employed, and a light output from the opening region 411a of each sub-pixel <NUM> can be expanded over the non-opening region 411b.

Accordingly, regarding a VR device that eyes of a viewer watch closely, a lattice-like pattern and an image blur can be effectively improved.

<FIG> (not forming part of the claimed invention) is a schematic perspective view illustrating a light path adjustment film of a display device according to a fifth embodiment of the present disclosure, and <FIG> (not forming part of the claimed invention) is a schematic perspective view illustrating a first pattern portion of a light path adjustment film according to the fifth embodiment of the present disclosure, <FIG> (not forming part of the claimed invention) is a schematic view illustrating a light path of a first pattern layer of a light path adjustment film according to the fifth embodiment of the present disclosure, and <FIG> (not forming part of the claimed invention) is a schematic view illustrating a light path of a second pattern layer of a light path adjustment film according to the fifth embodiment of the present disclosure.

Referring to <FIG>, the light path adjustment film <NUM> on the display panel may include a first pattern layer <NUM>, and a second pattern layer <NUM> on the first pattern layer <NUM>.

Each of the first pattern layer <NUM> and the second pattern layer <NUM> may include a plurality of first pattern portions P1 of a bar shape that have a major axis (or long axis) 2AX and a minor axis (or short axis) 1AX, and a plurality of second pattern portions P2 between the first pattern portions P1.

In this case, the major axis 2AX of the first pattern portion P1 of the first pattern layer <NUM> may be aligned along a first direction X, and the major axis 2AX of the first pattern portion P1 of the second pattern layer <NUM> may be aligned along a second direction Y perpendicular to the first direction X.

Referring to <FIG>, the first pattern portion P1 in each of the first and second pattern layers <NUM> and <NUM> may include a first surface <NUM> of a trapezoidal shape, a second surface <NUM> of a trapezoidal shape opposite to the first surface <NUM>, a third surface <NUM> connecting a bottom side LB of the first surface <NUM> and a bottom side LB of the second surface <NUM>, a fourth surface <NUM> opposite to the third surface <NUM>, and first and second slanted surfaces <NUM> and <NUM> each connecting the third and fourth surfaces <NUM> and <NUM>.

Accordingly, the area of the third surface <NUM> may be greater than the area of the fourth surface <NUM>.

The first surface <NUM> and the second surface <NUM> may be arranged on the minor axis 1AX. The third surface <NUM>, the fourth surface <NUM>, the first slanted surface <NUM> and the second slanted surface <NUM> may be arranged on the major axis 2AX.

Accordingly, the first pattern portion P1 may have a truncated quadrangular pyramid shape that has an acute angle θ1 and an obtuse angle θ2 and extends along the major axis 2AX.

The acute angle θ1 may be equal to or more than <NUM> degrees and less than <NUM> degrees.

A length of the bottom side LB of each of the first and second surfaces <NUM> and <NUM> may be <NUM> or less.

In each of the first and second pattern layers <NUM> and <NUM>, the plurality of first pattern portions P1 are arranged, and the plurality of second pattern portions P2 are arranged between the first pattern portions P1 and have a refractive index less than that of the first pattern portions P1.

The first pattern portions P1 may be arranged such that bottom sides of the first and second slanted surfaces <NUM> and <NUM> neighboring each other contact each other.

In other words, the first pattern portions P1 may be arranged with the third surfaces thereof contacting each other.

Since the first pattern layer <NUM> and the second pattern layer <NUM> are vertically arranged, a light from the display panel (e.g., <NUM> of <FIG>) can be expanded along the first direction X and the second direction Y.

Referring to <FIG>, a light from the display panel can be expanded along the second direction Y while passing through the first pattern layer <NUM>.

In detail, light, which is vertically input, from the opening region (e.g., 411a of <FIG>) of each sub-pixel (e.g., <NUM> of <FIG>), to a center portion of the third surface <NUM> of the first pattern layer <NUM>, is output through the fourth surface <NUM> of the first pattern layer <NUM> without refraction (e.g., a light path ①).

Light, which is input, from the opening region of each sub-pixel, to the first and second slanted surfaces <NUM> and <NUM> via the third surface <NUM> of the first pattern layer <NUM>, is totally reflected thus adjusted in path and is output to a region, which corresponds to the non-opening region (e.g., 411b of <FIG>), in the second direction Y, of the sub-pixel, through the fourth surface <NUM> of the first pattern layer <NUM> (e.g., a light path ②).

Further, while passing through the minute first pattern portion P1 of the first pattern layer <NUM>, the light is diffracted toward a side direction and thus a light output range may be further expanded along the second direction Y.

Referring to <FIG>, the light expanded along the second direction Y can be expanded along the first direction X while passing through the second pattern layer <NUM>.

In detail, light, which is vertically input, from the first pattern layer <NUM>, to a center portion of the third surface <NUM> of the second pattern layer <NUM>, is output through the fourth surface <NUM> of the second pattern layer <NUM> without refraction (e.g., a light path ①).

Light, which is input, from the first pattern layer <NUM>, to the first and second slanted surfaces <NUM> and <NUM> via the third surface <NUM> of the second pattern layer <NUM>, is totally reflected thus adjusted in path and is output to a region, which corresponds to the non-opening region (e.g., 411b of <FIG>), in the first direction X, of the sub-pixel, through the fourth surface <NUM> of the second pattern layer <NUM> (e.g., a light path ②).

Further, while passing through the minute first pattern portion P1 of the second pattern layer <NUM>, the light is diffracted toward a side direction and thus a light output range may be further expanded along the first direction X.

<FIG> is a schematic view illustrating light output ranges when passing through the first and second pattern layers in the display device according to the fifth embodiment of the present disclosure.

Referring to <FIG>, it is seen that light input to the first pattern layer <NUM> is expanded along the second direction Y while passing through the first pattern layer <NUM>.

Further, it is seen that the light expanded along the second direction Y by the first pattern layer <NUM> is expanded along the first direction X while passing through the second pattern layer <NUM>.

In other words, a light from the opening region of the sub-pixel can be expanded along the first and second directions X and Y while passing through the light path adjustment film <NUM> of this embodiment.

Accordingly, a lattice-like pattern produced at the non-opening regions can be effectively improved.

<FIG> are views illustrating another example of light path adjustment films according to the fifth embodiment of the present disclosure. <FIG> are not forming part of the claimed invention.

The first base film <NUM> supports the light path adjustment film <NUM>. The first base film <NUM> may contact the display panel and protect the display panel from a moisture or impact, and thus reliability can be achieved.

Referring to <FIG>, the first base film <NUM> and the second base film <NUM> may be located at the bottom and the top of the light path adjustment film <NUM>, respectively.

Referring to <FIG>, the first base film <NUM> and the second base film <NUM> may be attached to the bottom and the top of the light path adjustment film <NUM>, respectively, and a third base film <NUM> may be located between the first and second pattern layers <NUM> and <NUM>.

Referring to <FIG>, the first base film <NUM> and the second base film <NUM> may be attached to the bottom and the top of the light path adjustment film <NUM>, respectively, and an adhesive tape T may be located between the first and second pattern layers <NUM> and <NUM>.

Each of the first, second and third base films <NUM>, <NUM> and <NUM> may be made of a polyethylene terephthalate (PET), polycarbonate (PC), or acryl based material.

The adhesive tape T may be a double-sided adhesive tape coated with an optical adhesive material. Accordingly, the first and second pattern layers <NUM> and <NUM> may be firmly fixed.

As described above, the base film <NUM>, <NUM> or <NUM> or the adhesive tape T may be arranged in various manners in order to adhere or support the light path adjustment film <NUM>.

Referring to <FIG>, the light path adjustment film <NUM> may be an inverted arrangement compared with the above examples of this embodiment.

In other words, the second pattern layer <NUM> may be located on the display panel, and the first pattern layer <NUM> may be located on the second pattern layer <NUM>.

In this case, each of the first and second pattern layers <NUM> and <NUM> may include a plurality of first pattern portions P1 of a bar shape that have a major axis (or long axis) 2AX and a minor axis (or short axis) 1AX, and a plurality of second pattern portions P2 between the first pattern portions P1.

The first pattern portion P1 in each of the first and second pattern layers <NUM> and <NUM> may include a first surface <NUM> of an inverted trapezoidal shape, a second surface <NUM> of an inverted trapezoidal shape opposite to the first surface <NUM>, a third surface <NUM> connecting a bottom side LB of the first surface <NUM> and a bottom side LB of the second surface <NUM>, a fourth surface <NUM> opposite to the third surface <NUM>, and first and second slanted surfaces <NUM> and <NUM> each connecting the third and fourth surfaces <NUM> and <NUM>.

Accordingly, the area of the fourth surface <NUM> may be greater than the area of the third surface <NUM>.

Accordingly, the first pattern portion P1 may have an inverted truncated quadrangular pyramid shape that has an acute angle θ1 and an obtuse angle θ2 and extends along the major axis 2AX.

A length of a top side HB of each of the first and second surfaces <NUM> and <NUM> may be <NUM> or less.

Since the first pattern layer <NUM> and the second pattern layer <NUM> are vertically arranged, a light from the display panel can be expanded along the first direction X and the second direction Y.

Accordingly, a lattice-like pattern can be effectively improved.

Referring to <FIG>, the first pattern portions P1 are spaced apart from each other.

In other words, the first pattern portions P1 of each of the first and second pattern layer <NUM> and <NUM> are spaced apart at a predetermined distance k from each other.

The distance k between the first pattern portions P1 may be <NUM> or less.

As described above, in this embodiment, the light path adjustment film <NUM> including the first and second pattern layers <NUM> and <NUM> vertically arranged are used. Thus, a light from the opening region of each sub-pixel can be expanded along the first and second directions X and Y, and a lattice-like pattern can be effectively reduced.

<FIG> is a picture of the display device according to the fourth or fifth embodiment of the present disclosure.

Referring to <FIG>, since the display device outputs lights from each sub-pixel (e.g., <NUM> of <FIG>) to regions corresponding to the opening region (e.g., 411a of <FIG>) and the non-opening region (e.g., 411b of <FIG>) of the sub-pixel via the light path adjustment film (e.g., <NUM> of <FIG> or <NUM> of <FIG>), it is seen that a clear image is produced and a lattice-like pattern is reduced.

<FIG> is a schematic view illustrating an example of a display device according to an embodiment of the present disclosure. By way of example, an organic light emitting display panel is used for the display device <NUM>.

Referring to <FIG>, the display device <NUM> may include a heat sink film <NUM>, an organic light emitting diode (OLED) display panel <NUM> on the heat sink film <NUM>, a light path adjustment film <NUM> on the OLED display panel <NUM>, a polarizing plate <NUM> on the light path adjustment film <NUM>, and a cover glass <NUM> on the polarizing plate <NUM> and protecting the OLED display panel <NUM>. One of the light path adjustment films of the above embodiments is used as the light path adjustment film <NUM>.

The heat sink film <NUM> functions to prevent a heat produced in operating the OLED display panel <NUM> and a rapid reduction of lifetime due to a deterioration of a driving thin film transistor Td. The heat sink film <NUM> may be configured to have a continuously uneven shape in order to increase a surface area contacting an ambient air.

The OLED display panel <NUM> may include a first substrate <NUM> including a plurality of sub-pixels Pr, Pg and Pb, a plurality of organic light emitting diodes E formed at the respective sub-pixels Pr, Pg and Pb, and an encapsulation layer <NUM> covering the organic light emitting diodes E.

The driving thin film transistor Td is formed in each sub-pixel on an inner surface of the first substrate <NUM>, and a first passivation layer <NUM> is formed on the driving thin film transistors Td.

The driving thin film transistor Td includes a semiconductor layer, a gate electrode, a source electrode and a drain electrode. An inter-layered insulating layer is formed on the gate electrode, and a data line <NUM> is formed on the inter-layered insulating layer.

A first electrode 615a is formed on the first passivation layer <NUM> in each sub-pixel and is connected to the driving thin film transistor Td. Organic light emitting layers 615b emitting red (R), green (G) and blue (B) are formed in the respective sub-pixels Pr, Pg and Pb. A second electrode 615c is formed entirely on the organic light emitting layers 615b.

A bank layer <NUM> is formed on the first electrode 615a. The bank layer <NUM> functions to separate the organic light emitting layers 615b emitting (R), green (G) and blue (B) into the respective sub-pixels Pr, Pg and Pb.

The first electrode 615a, the organic light emitting layer 615b and the second electrode 615c in each sub-pixel constitutes the organic light emitting diode E.

A second passivation layer <NUM> is formed on the second electrode 615c, and the encapsulation layer <NUM> is formed on the second passivation layer <NUM>.

The encapsulation layer <NUM> may be formed with a multi-layered structure using an organic layer and/or an inorganic layer on the second passivation layer <NUM>, or may be formed with a face seal on the second passivation layer <NUM>.

The first substrate <NUM> may be referred to as a lower substrate, a TFT substrate or backplane and may be made of glass or plastic.

The second passivation layer <NUM> functions to prevent penetration of a moisture or foreign substance from the outside. The encapsulation layer <NUM> functions to prevent penetration of a moisture or foreign substance from the outside, and to absorb an external impact as well. The above-described structure of the OLED display panel <NUM> is by way of example, and the OLED display panel <NUM> may have other structure.

An adhesive material may be coated on the OLED display panel <NUM>, and the light path adjustment film <NUM> may be attached to the OLED display panel. Accordingly, a path of a light produced by the OLED display panel <NUM> is expanded to a region that corresponds to the non-opening region (e.g., 411b of <FIG>), and thus a clear image can be maintained and a lattice-like pattern can be reduced.

The OLED display panel <NUM> is protected by the light path adjustment film <NUM>, and reliability of the OLED display panel <NUM> can further rise.

The polarizing plate <NUM> prevents light, which is produced by the OLED display panel <NUM>, and an external light, which enters the OLED display panel <NUM> and is reflected in a reflecting material in the OLED display panel <NUM>, causing a mutual interference and degrading a display performance. In the polarizing plate <NUM> as a reflection preventing filter, an absorption axis of a polarizer and an optical axis (e.g., an absorption axis) of a retardation film are arranged off-axis to rotate the external light reflected by the reflecting material in the OLED display panel <NUM>.

The light path adjustment film <NUM> located between the OLED display panel <NUM> and the polarizing plate <NUM> is described by way of example. The light path adjustment film <NUM> may be located at other positions, for example, on the polarizing plate <NUM>.

When the display device <NUM> is applied to a VR device, the cover glass <NUM> and the polarizing plate <NUM> may be eliminated because of a structure of the VR device.

<FIG> is a schematic view illustrating an example of a display device according to an embodiment of the present disclosure. By way of example, a liquid crystal display panel is used for the display device.

Referring to <FIG>, the display device <NUM> may include a liquid crystal display panel <NUM> and a light path adjustment film <NUM> on the liquid crystal display panel <NUM>. One of the light path adjustment films of the above embodiments is used as the light path adjustment film <NUM>.

The liquid crystal display panel <NUM> may include a first substrate <NUM>, a second substrate <NUM> and a liquid crystal layer <NUM> between the first and second substrates <NUM> and <NUM>.

A plurality of gate lines along a direction are formed on the first substrate <NUM>. A plurality of common lines are formed on the first substrate, and are spaced apart from and parallel with the corresponding gate lines.

A thin film transistor Tr as a switching element is formed in a switching region TrA, and includes a gate electrode <NUM>, a gate insulating layer <NUM>, a semiconductor layer <NUM>, and source and drain electrodes <NUM> and <NUM> spaced apart from each other.

A plurality of data lines <NUM> are formed on the gate insulating layer <NUM> and cross the plurality of gate lines to define a plurality of sub-pixels Pa. The data line <NUM> is connected to the source electrode <NUM>.

A first passivation layer <NUM> made of, for example, an inorganic insulating material is formed on the thin film transistor Tr and the data line <NUM>, and a second passivation layer <NUM> made of, for example, an organic insulating material are formed on the first passivation layer <NUM> and has a flat top surface. The first and second passivation layers <NUM> and <NUM> have a drain contact hole 719a exposing the drain electrode <NUM>, and a common contact hole exposing the common line.

A plurality of pixel electrodes <NUM> and a plurality of common electrodes <NUM> are formed on the second passivation layer <NUM> in each sub-pixel Pa, and are alternately arranged in the sub-pixel Pa. Each of the pixel electrode <NUM> and the common electrode <NUM> is made of a transparent conductive material, for example, ITO or IZO. The pixel electrode <NUM> is connected to the drain electrode <NUM> through the drain contact hole 719a, and the common electrode <NUM> is connected to the common line through the common contact hole.

A black matrix <NUM> is formed on an inner surface of the second substrate <NUM>, and corresponds to a boundary portion of each sub-pixel and the thin film transistor Tr. A color filter layer <NUM>, which includes red (R), green (G) and blue (B) color filter patterns corresponding to the respective sub-pixels, are formed on the second substrate <NUM>. An edge portion of the color filter pattern may overlap the black matrix <NUM>.

An overcoat layer <NUM> is formed on the color filter layer <NUM>, and has a flat surface.

First and second polarizing plates <NUM> and <NUM> are located on outer surfaces of the first and second substrates <NUM> and <NUM>. Each of the first and second polarizing plates <NUM> and <NUM> transmits light which has a polarized direction parallel with a transmission axis of each of the first and second polarizing plates <NUM> and <NUM>. Arrangement of the transmission axes of the first and second polarizing plates <NUM> and <NUM> and alignment of the liquid crystal molecules determines light transmission. For example, the transmission axes of the first and second polarizing plates <NUM> and <NUM> are perpendicular to each other.

The light path adjustment film <NUM> may be attached on an outer surface of the second polarizing plate <NUM>. Alternatively, the light path adjustment film <NUM> may be interposed between the second substrate <NUM> and the second polarizing plate <NUM>. Accordingly, the light path adjustment film <NUM> expands a path of a light produced by the liquid crystal display panel <NUM> to a region which corresponds to the non-opening region (e.g., 411b of <FIG>), and thus the display device <NUM> which can maintain a clear image and reduce a lattice-like pattern can be achieved.

In this embodiment, the liquid crystal display panel is described by way of example, and other type display panel may be used.

Further, in the above embodiments, the pentile structure is described by way of example, and other structure may be used.

Claim 1:
A display device (<NUM>) comprising:
a display panel (<NUM>) including a plurality of pixels (<NUM>) each having a plurality of sub-pixels (<NUM>); and
a light path adjustment film (<NUM>) on the display panel,
wherein the light path adjustment film includes a first base film (<NUM>, <NUM>), and a pattern layer (<NUM>, <NUM>) on a surface of the first base film,
wherein the pattern layer includes a plurality of first patterns (<NUM>, (<NUM>, P1) having a first refractive index, and a plurality of second patterns (<NUM>, P2) between the first patterns and having a second refractive index, wherein the second refractive index is less than the first refractive index,
wherein the second patterns are disposed between the first patterns and the thickness of the second pattern is same as the thickness of the first pattern so that the adjacent first patterns are discretely disposed to each other by the second pattern therebetween, and
wherein the first pattern includes a top surface spaced apart from the display panel and parallel with the display panel, a bottom surface between the top surface and the display panel, and a slanted surface connecting the top surface and the bottom surface:
wherein either:
the bottom surface of the first pattern has a size greater than that of the top surface of the first pattern and wherein each first pattern corresponds to each sub-pixel,
wherein the size of the top surface of the first pattern is greater than that of an opening region (111a, 113a) of the sub-pixel, and
wherein the size of the bottom surface of the first pattern is equal to or less than that of the sub-pixel;
or
the top surface of the first pattern has a size greater than that of the bottom surface of the first pattern; and wherein each first pattern corresponds to each sub-pixel,
wherein the size of the bottom surface of the first pattern is greater than that of an opening region of the sub-pixel, and
wherein the size of the top surface of the first pattern is equal to or less than that of the sub-pixel.