KR20140006211A - Optical film for a display, light source assembly including the same and liquid crystal display including the optical film - Google Patents

Abstract

Provided is an optical sheet having a plurality of a light modulation, a light source assembly and a liquid crystal display including the optical sheet. The optical sheet has a first base material; a first optical modulation layer including a plurality of auxiliary prisms, which are shorter than main prism, and formed on an upper surface of the first base material; a second base material located on an upper side of the first surface material apart from the first base material; a bonding layer formed on an upper surface of the second base material and linked to at least partition of the prisms.

Description

Technical Field [0001] The present invention relates to an optical sheet for a display, a light source assembly including the same, and a liquid crystal display device including the optical sheet for a display, a light source assembly including the same and a liquid crystal display including the optical film,

The present invention relates to an optical sheet, and more particularly, to an optical sheet applied to a display, a light source assembly including the optical sheet, and a liquid crystal display.

A liquid crystal display (LCD) is a device for displaying an image by injecting liquid crystal between two glass plates and applying power to the upper and lower glass plate electrodes to change the arrangement of liquid crystal molecules in each pixel. Unlike a cathode ray tube (CRT), a plasma display panel (PDP) or the like, a display using a liquid crystal display device is not usable in a place where there is no light because the display itself is non-luminous. In order to compensate for these drawbacks, a light source assembly that is uniformly irradiated on the information display surface is mounted for the purpose of enabling use in a dark place.

The light source assembly used in the liquid crystal display device is divided into two types. The first is an edge type light source assembly that provides light at the side of the liquid crystal display device, and the second is a direct light type light source assembly that provides light directly at the rear side of the liquid crystal display device. In some edge type light source assemblies, a light guide plate is provided so that light emitted from a light source is irradiated upward, and at least one optical sheet is provided above the light guide plate to control optical characteristics of light passing through the light guide plate. In the case of some direct type light source assemblies, a diffusion plate is provided to reduce the light lines of light emitted from the light source, and at least one optical sheet is provided to control the optical characteristics of light passing through the diffusion plate.

One of the parameters determining the display quality of the liquid crystal display device is optical characteristics. In order to control the optical characteristics more precisely, a plurality of optical sheets are required. However, if the number of optical sheets is increased, not only the thickness of the liquid crystal display device becomes thick, but also the manufacturing process becomes complicated and the manufacturing cost increases.

An object of the present invention is to provide an optical sheet in which a plurality of light modulation characteristics are effectively implemented.

Another object of the present invention is to provide a light source assembly in which a plurality of light modulation characteristics are effectively implemented by an optical sheet.

Another object of the present invention is to provide a liquid crystal display device in which a plurality of light modulation characteristics are effectively implemented by an optical sheet, thereby improving image quality.

The problems of the present invention are not limited to the above-mentioned problems, and other problems not mentioned can be clearly understood by those skilled in the art from the following description.

The optical sheet according to an embodiment of the present invention for solving the above problems is a first light modulation layer formed on the first substrate, the lower surface of the first substrate, a plurality of main prisms and a plurality of heights smaller than the main prism A first light modulation layer including an auxiliary prism, a second substrate disposed spaced apart from the first substrate, and a bonding layer formed on an upper surface of the second substrate, and at least partially bonded to the main prism.

An optical sheet according to another embodiment of the present invention for solving the above problems is a first substrate, a second substrate disposed spaced apart from the first substrate, a first optical modulation layer formed on the upper surface of the second substrate, And a first light modulation layer comprising a main prism of and a plurality of auxiliary prisms having a height smaller than that of the main prism, and a bonding layer formed on the bottom surface of the first substrate, the main prism being at least partially bonded thereto.

According to another aspect of the present invention, there is provided a light source assembly including the optical sheet as described above.

According to another aspect of the present invention, there is provided a liquid crystal display device including the optical sheet as described above.

The details of other embodiments are included in the detailed description and drawings.

The embodiments of the present invention have at least the following effects.

That is, according to the optical sheet according to the embodiments of the present invention, even when using a relatively small number of substrates, it is possible to effectively exhibit a plurality of optical modulation characteristics.

According to the light source assembly according to the embodiments of the present invention, the thickness can be reduced, and the assembly process can be simplified.

In addition, according to the liquid crystal display according to the exemplary embodiments of the present invention, not only the thickness is reduced, but also the image quality may be improved as the light having the plurality of light modulation characteristics is effectively improved.

The effects according to the present invention are not limited by the contents exemplified above, and more various effects are included in the specification.

1 is a perspective view of an optical sheet according to an embodiment of the present invention.
2 is a cross-sectional view taken along line II-II 'of FIG.
3 is a bottom perspective view of the first light modulation layer of FIG. 1.
4A is a bottom view of the first light modulation layer of FIG. 1.
4B is a SEM photograph of the first light modulation layer according to the embodiment of the present invention viewed from the bottom.
5 is a cross-sectional view of an optical sheet according to another embodiment of the present invention.
6 to 10 are cross-sectional views of an optical sheet according to still other embodiments of the present invention.
11 is a bottom perspective view of a first light modulation layer of an optical sheet according to another embodiment of the present invention.
12 is a cross-sectional view taken along the line XII-XII ′ of FIG. 11.
FIG. 13 is a bottom perspective view of a first light modulation layer of an optical sheet according to another embodiment of the present invention. FIG.
14 to 17 are cross-sectional views of an optical sheet according to still other embodiments of the present invention.
18 is a cross-sectional view of a liquid crystal display according to an exemplary embodiment of the present invention.

Advantages and features of the present invention and methods for achieving them will be apparent with reference to the embodiments described below in detail with the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Is provided to fully convey the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims.

It is to be understood that elements or layers are referred to as being "on " other elements or layers, including both intervening layers or other elements directly on or in between. On the other hand, a device being referred to as "directly on" refers to not intervening another device or layer in the middle. Like reference numerals refer to like elements throughout. "And / or" include each and any combination of one or more of the mentioned items.

Although the first, second, etc. are used to describe various components, it goes without saying that these components are not limited by these terms. These terms are used only to distinguish one component from another. Therefore, it goes without saying that the first component mentioned below may be the second component within the technical scope of the present invention.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. In the present specification, the singular form includes plural forms unless otherwise specified in the specification. The terms " comprises "and / or" comprising "used in the specification do not exclude the presence or addition of one or more other elements in addition to the stated element.

Unless otherwise defined, all terms (including technical and scientific terms) used in the present specification may be used in a sense that can be commonly understood by those skilled in the art. Also, commonly used predefined terms are not ideally or excessively interpreted unless explicitly defined otherwise.

The terms spatially relative, "below", "beneath", "lower", "above", "upper" And can be used to easily describe a correlation between an element and other elements. Spatially relative terms should be understood in terms of the directions shown in the drawings, including the different directions of components at the time of use or operation. For example, when inverting an element shown in the figures, an element described as "below" or "beneath" of another element may be placed "above" another element . Thus, the exemplary term "below" can include both downward and upward directions. The components can also be oriented in different directions, so that spatially relative terms can be interpreted according to orientation.

As used herein, the term "film" can be used in the sense of "to sheet"

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

1 is a perspective view of an optical sheet according to an embodiment of the present invention. 2 is a cross-sectional view taken along line II-II 'of FIG. 3 is a bottom perspective view of the first light modulation layer of FIG. 1. 4A is a bottom view of the first light modulation layer of FIG. 1. FIG. 4B is a SEM image of the first light modulation layer according to the embodiment of the present invention viewed from the bottom.

1 to 4B, the optical sheet 11 is spaced apart from the first substrate 100 and the first optical modulation layer 111 and the first substrate 100 formed on the bottom surface of the first substrate 100. The second substrate 200 is disposed, and the bonding layer 250 is formed on the upper surface of the second substrate 200, and the first light modulation layer 111 is at least partially bonded. The second light modulation layer 130 may be formed on the upper surface of the first substrate 100.

The first substrate 100 serves to support the first light modulation layer 111 and the second light modulation layer 130. The first substrate 100 may be made of a material capable of transmitting light. For example, the first substrate 100 may be formed of a material selected from the group consisting of a polycarbonate series, a poly sulfone series, a polyacrylate series, a polystyrene series, a poly vinyl chloride , Polyvinyl alcohol series, poly norbornene series, and polyester ester series materials. [0034] The term " polyvinyl alcohol "

In some embodiments, the first substrate 100 may guide the light incident thereon to exit straight. In some other embodiments, the first substrate 100 may itself have optical modulation properties such as polarization, diffusion, reflection, and the like. For example, the first base material 100 may be a polarizing film, a diffusion film, a reflective film, a reflective polarizing film, a protective film, a retardation film, or a brightness enhancement film.

The first light modulation layer 111 and the second light modulation layer 130 modulate and output a path of light incident into the layer. The light modulation includes refraction, condensation, diffusion, scattering, and the like. In this embodiment, a case where the cross prism pattern layer is applied to the first light modulation layer 111 and the microlens layer is applied to the second light modulation layer 130 will be described.

The first light modulation layer 111 may include a plurality of prisms 111a and 111b. Prisms 111a and 111b may include two inclined prism faces. The two prism surfaces cross each other to form a peak. The peak portion may include the tips of the prisms 111a and 111b. The traveling direction of the intersection defined by the intersection of the two prism faces, that is, the extending direction of the peak portion, may be defined as the extending directions of the prisms 111a and 111b. The two prism planes refract light passing through it and change the light path. It is possible to perform the condensing and diverging functions at the same time by focusing the light mainly on the peak toward the peak (or the plane perpendicular to the bottom passing through the peak) or by diverging the light mainly in the direction away from the peak.

In the cross section perpendicular to the extension direction of the prisms 111a and 111b, three line segments or their extension lines derived from both prism faces and the bottom face of the prism may define a triangle. In FIG. 2, the triangle defined by the cross sections of the prisms 111a and 111b is an isosceles triangle, but is not limited thereto, and may be an acute triangle, a right triangle, or an obtuse triangle. Also in the case of an obtuse triangle, the vertex angle forming the peaks of the prisms 111a and 111b may be an obtuse angle, but other internal angles may be an obtuse angle.

The plurality of prisms includes a plurality of main prisms 111a and a plurality of auxiliary prisms 111b. Each main prism 111a may extend in a first direction X1, and each auxiliary prism 111b may extend in a second direction X2 crossing the first direction X1. In some embodiments, the crossing angle of the first direction X1 and the second direction X2 may be 90 °.

The main prism 111a and the auxiliary prism 111b collect or diverge light passing through the prism face with respect to the ridge (or a plane perpendicular to the bottom surface passing through the ridge). When the main functions of the main prisms 111a and the auxiliary prisms 111b are condensing, the main prisms 111a allow light to converge on the mountain side without spreading in the direction perpendicular to the first direction X1, and the auxiliary prisms ( 111b) allows light to gather without spreading in a direction perpendicular to the second direction X2. Therefore, even if a plurality of separate prism sheets are not used, not only the direction perpendicular to the first direction X1 but also the direction perpendicular to the second direction X2 by the main prism 111a and the auxiliary prism 111b. Light can also be collected. Accordingly, it may be advantageous in terms of brightness and slimming.

The main prism 111a may be continuously formed from one side A to the other side B of the first substrate 100. Adjacent main prisms 111a may be adjacent to each other, but may also be partially spaced apart. Here, that the main prisms 111a are adjacent to each other includes bottom surfaces of the main prisms 111a adjacent to each other.

The auxiliary prism 111b is disposed between the main prisms 111a. Even though the neighboring main prisms 111a are adjacent to each other, since the prism faces are inclined, the inclined surfaces of the neighboring main prisms 111a are spaced apart from each other except for the bottom surface, so that the auxiliary prism 111b is located in this space. Can be.

The auxiliary prism 111b may have an extension length defined by the main prism 111a. That is, the maximum extension length of one auxiliary prism 111b may be less than or equal to the distance between the peaks of neighboring main prisms 111a disposed. The auxiliary prisms 111b positioned at both sides with respect to one main prism 111a may have the same extension direction, and further, the extension lines may coincide with each other. In this case, the plurality of auxiliary prisms 111b are generally line type, but it may be understood that they are interrupted by the main prisms 111a. Therefore, when the first direction X1 and the second direction X2 vertically intersect, the main prism 111a and the auxiliary prism 111b have an arrangement in which they cross each other in the form of a checkerboard.

Adjacent auxiliary prisms 111b along the first direction X1 may be spaced apart from each other, but may be adjacent to each other.

Since the auxiliary prism 111b is positioned on the inclined surface of the main prism 111a, light modulation characteristics inherent to the main prism 111a may be sacrificed in this region. That is, as the auxiliary prisms 111b are densely generated, the light modulation characteristics by the auxiliary prisms 111b are enhanced, but the light modulation characteristics by the main prisms 111a are weakened. Therefore, the number and density of the auxiliary prisms 111b or the degree of adjoining between the neighboring auxiliary prisms 111b may be differently applied depending on the degree of light modulation characteristics of the auxiliary prisms 111b.

The vertex angle θ of the main prism 111a and the auxiliary prism 111b may be selected in the range of 45 ° to 135 °. In this specification, the apex angle of the prism can be defined as an angle formed by a substantially inclined surface of the prism. Here, the substantially inclined surface may include a virtual surface that can be recognized as an overall average inclined surface even if the surface of the prism is rugged. In the case where the inclined surface of the prism is formed with a certain angle but has an angle different from that of the other inclined surface near the peak, if the dominant shape of the prism is recognized by the inclined surface having a constant angle, It can be defined as an angle.

In some embodiments, the vertex angle θ of each prism 111a, 111b may be between 60 ° and 130 °. In some other embodiments, the vertex angle θ of each prism 111a, 111b may be between 60 ° and 90 °. When the first light modulation layer 111 is applied as an inverted prism in which a prism surface acts as a light incident surface, the vertex angles θ of each prism 111a and 111b may be formed at an acute angle.

The vertex angle θ of the main prism 111a and the vertex angle θ of the auxiliary prism 111b may be the same, but may be different.

Although the width W1 of the main prism 111a and the auxiliary prism 111b may also be the same, they may differ.

The height h2 of the auxiliary prism 111a may be less than or equal to half of the height h1 of the main prism 111a.

The main prism 111a and the auxiliary prism 111b may be formed on the entire surface of the first substrate 100. When the first substrate 100 has a rectangular shape in plan view, the first direction X1 may be parallel to the long side or the short side of the first substrate 100. In addition, the second direction X2 may be parallel to the short side or the long side of the first substrate 100.

In some other embodiments, the first direction X1 and the second direction X2 may each have an acute angle of intersection with the long side and / or the short side of the first substrate 100. For example, the crossing angle may be in the range of ± 1 to ± 45 °.

The second light modulation layer 130 may include a plurality of micro lenses 130a. Each micro lens 130a may have a shape of a structure that is understood to be left by cutting a sphere or ellipsoid into a specific surface. Therefore, each micro lens 130a may have a curved surface. The cut surface can pass through the center of a sphere or an ellipsoid. In this case, the microlens 130a has the shape of a hemisphere or a semi-ellipse. As another example, the cut surface may be formed to have a smaller size than the hemispherical or semi-ellipsoid beyond the center of the sphere or ellipsoid. As another example, the cut surface may be formed to have a larger size than the hemispherical or semi-ellipsoid beyond the center of the sphere or ellipsoid. In yet another variation, the microlenses may be structures comprising curved surfaces not derived from spheres or ellipsoids.

In an exemplary embodiment, the size of the microlens 130a may be selected in the range of 10 μm to 100 μm in width of the surface contacting the first substrate surface. Although the size of each micro lens 130a may be uniform, various micro lenses 130a having different values within the above range may be disposed.

Each micro lens 130a may be formed on the entire surface of the first substrate 100. The neighboring micro lenses 130a may be adjacent to each other, but may be spaced in whole or in part. In an exemplary embodiment, the micro lenses 130a may be arranged substantially parallel along the third direction X3. Furthermore, the microlens 130a may be arranged substantially parallel along the fourth direction X4 crossing the third direction X3. The third direction X3 may be parallel to the first direction X1, and the fourth direction X4 may be parallel to the second direction X2. The crossing angle of the third direction X3 and the fourth direction X4 may be 90 °, but is not limited thereto, and may be an acute angle or an obtuse angle.

The second substrate 200 is spaced apart from the first substrate 100. The second substrate 200 may be formed of a material selected from the group consisting of a polycarbonate series, a poly sulfone series, a poly acrylate series, a polystyrene series, a poly vinyl chloride series, a poly A polyvinyl alcohol series, a poly norbornene series, and a polyester ester series material. The second substrate 200 may be made of the same material as the first substrate 100.

The bonding layer 250 is formed on the upper surface of the second substrate 200. The bonding layer 250 may be composed of an adhesive layer, an adhesive layer, or a resin layer. Examples of the material constituting the adhesive layer include a silicone polymer, a urethane polymer, a silicone-urethane hybrid structure, an SU polymer, an acrylic polymer, an isocyanate polymer, a polyvinyl alcohol polymer, a gelatin polymer, a vinyl polymer, a latex polymer, A high-transparency adhesive containing a high molecular substance classified into < RTI ID = 0.0 >

The first light modulation layer 111 is disposed to face the coupling layer 250, and the first light modulation layer 111 is in contact with the coupling layer 250 at least partially to contact the first light modulation layer 111. The substrate 200 may be fixedly coupled. For example, an acid portion of the main prism 111a may be disposed to penetrate into the bonding layer 250. On the other hand, when the height h2 of the auxiliary prism 111b is smaller than half of the height h1 of the main prism 111a, the peak of the main prism 111a is bonded to the bonding layer 250, but the auxiliary prism 111b ) May be easily formed without being bonded to the bonding layer 250 and spaced therefrom. Accordingly, the peak of the auxiliary prism 111b may be exposed to the air layer.

Since the auxiliary prism 111b is smaller than the main prism 111a and is formed intermittently, it may be expected that the light modulation characteristics of the auxiliary prism 111b are weaker than the main prism 111a. However, when the peak portion of the main prism 111a penetrates into the bonding layer 250, the peak portion penetrated into the bonding layer 250 weakens the light modulation function. If the refractive index of the main prism 111a and the refractive index of the bonding layer 250 are at the same or similar level, the peak portion of the main prism 111a almost loses its optical modulation function. On the other hand, in the case of the auxiliary prism 111b, the acid part may be completely exposed to the air layer, thereby exhibiting sufficient light modulation characteristics. Therefore, even when the size of the auxiliary prism 111b is small or small in density, it is possible to sufficiently maintain the light modulation characteristics relatively.

In order to firmly bond the first light modulation layer 111 and the second substrate 200, it is preferable that the depth of penetration of the main prism 111 a into the bonding layer 250 is deep. As described above, when the height h2 of the auxiliary prism 111b is less than or equal to half the height of the main prism 111a, the depth of the main prism 111a penetrating into the bonding layer 250 is determined by the main prism 111a. Even if it is deepened to about half of the total height h1, the peak of the auxiliary prism 111b can be exposed to air. That is, when the height h2 of the auxiliary prism 111b is less than or equal to half of the height h1 of the main prism 111a, the first light modulation layer 111 is sufficiently maintained while maintaining the light modulation characteristics of the auxiliary prism 111b. ) And a margin that can firmly bond the second substrate 200 increases.

A mat layer 240 may be formed on the lower surface of the second substrate 200. The mat layer 240 may be formed by curing a resin layer including a plurality of beads. As another example, the mat layer 240 may be formed in an emboss pattern having a predetermined surface roughness. Further details of the mat layer 240 are described in Korean Patent Application No. 10-2008-0052646 and Korean Patent Application No. 10-2008-0103147 as emboss pattern, adhesion prevention layer, multiple beads, etc., The disclosure of which is incorporated herein by reference as if fully set forth herein.

Although not shown, other optical modulation layers may be formed on the lower surface of the second substrate 200 in place of the matte layer 240. Examples of the other optical modulation layer include a prism layer, a cross prism layer, a micro lens layer, a lenticular layer, a diffusion layer, and the like.

As described above, the optical sheet 11 according to the present embodiment includes a plurality of light modulation layers 111 and 130. When the light source (not shown) is positioned below the second substrate 200, the first light modulation layer 111 may exhibit a condensing function as an inverse prism in which a prism surface acts as an incident surface. Condensing is possible not only in the extending direction of the main prism 111a but also in the extending direction of the auxiliary prism 111b. In addition, the second light modulation layer 130 may exhibit a condensing or diffusing function as the micro lens 130a. Thus, even using a single optical sheet can exhibit various light modulation characteristics.

5 is a cross-sectional view of an optical sheet according to another embodiment of the present invention. Referring to FIG. 5, the optical sheet 12 according to the present exemplary embodiment illustrates that the first light modulation layer 112 has main prisms 112a_1 and 112a_2 of various sizes. The size of the main prism 112a depends on the width and height of the prism. The main prism 112a of the first light modulation layer 112 may include a first prism 112a_1 having a relatively large size and a second prism 112a_2 having a relatively small size. The arrangement of the first prism 112a_1 and the second prism 112a_2 may be variously selected. In FIG. 5, a case where one first prism 112a_1 is arranged per three second prisms 112a_2 is illustrated. In the drawing, the case where the height of the auxiliary prism 112b is smaller than half of the height of the second prism 112a_2 is illustrated, but is not limited thereto. In addition, in the drawing, the case where the peak portion of the second prism 112a_2 penetrates into the bonding layer 250 is illustrated, but only the first prism 112a_1 of the main prism 112a penetrates into the bonding layer 250, and The two prisms 112a_2 may be exposed to the acid in the air.

6 is a cross-sectional view of an optical sheet according to another embodiment of the present invention. Referring to FIG. 6, the optical sheet 13 according to the present exemplary embodiment may show that the pitch of the main prism 113a of the first optical modulation layer 113 may not be constant. In a particular embodiment, the main prism pitch 113a may show a regular change as it progresses from one side A to the other side B. FIG. For example, the pitch of the main prism 113a may decrease as one goes from one side A to the other side B and at the same time, the smaller the pitch from one side A to the other side B. In some embodiments, the largest of the vertices of the main prism 113a disposed on one side, the value may be 90 °.

Such a structure makes the optical path changes at one side (A) and the other side (B) different. For example, when the light source is disposed on one side (A) or relatively closer to the one side (A) and the amount of incident light is large, the luminance uniformity of the entire optical sheet (13) . Therefore, it may be employed as an optical sheet for improving luminance uniformity in the edge type light source assembly.

Although not shown in the drawings, the pitch may not be constant even in the case of the auxiliary prism 113b, and in some embodiments, a regular pitch may be changed as it progresses from one side to the other side.

7 is a cross-sectional view of an optical sheet according to another embodiment of the present invention. Referring to FIG. 7, in the optical sheet 14 according to the present exemplary embodiment, the pitch of the main prism 114a of the first light modulation layer 114 decreases from one side A to the center portion, and then again the other side B. This point is different from the embodiment of FIG. 6. In the case where the light source is located at one side (A) and the other side (B) in the edge type light source assembly, it may be usefully employed for improving luminance uniformity. Of course, the above deformation may be applied to the pitch of the auxiliary prism 114b.

8 is a sectional view of an optical sheet according to another embodiment of the present invention. Referring to FIG. 8, the optical sheet 15 according to the present embodiment exemplarily shows that the inclination angles of two inclined prism surfaces of the first prism 115a of the first optical modulation layer 115 may be different from each other. . The illustrated example is a case where the inclination angle α of the prism face of one side A of each main prism 115a is larger than the inclination angle β of the prism face of the other side B. That is, the prism face inclination angle α of one side A of the main prism 115a is about 40 ° to 75 °, and the prism face inclination angle β of the other side B is about 30 ° to 45 ° in one side (A). ) A value smaller than the prism face inclination angle α may be selected. The present embodiment may be employed to improve luminance when the light source LS is disposed on one side A or relatively closer to one side A, for example, in the case of an increased amount of light incident, for example, an edge type light source assembly. The same modification may be applied to the auxiliary prism 115b.

9 is a cross-sectional view of an optical sheet according to another embodiment of the present invention. 9 exemplarily shows that the prism surface of the first light modulation layer 116 of the optical sheet 16 is not flat but has an uneven surface, and thus may have a predetermined roughness. In the illustrated example, both the prism faces of the primary prism 116a and the secondary prism 116b have a rough surface, but only one of them may have a rough surface.

10 is a cross-sectional view of an optical sheet according to another embodiment of the present invention. Referring to FIG. 10, the shape of the main prism 117a of the first optical modulation layer 117 is different from that of the embodiment of FIG. 2. That is, the valley part of the main prism 117a is not adjacent to the surface of the 1st base material 100, and is somewhat spaced apart. The main prism 117a has a predetermined trunk thickness from the lower surface to the prism bone. Exemplary torso thickness may be 5% to 50% of the total height of the prism, but is not limited thereto. Although the auxiliary prism 117b is shown in the same shape as the embodiment of FIG. 2 in the drawing, the auxiliary prism may also have a predetermined trunk thickness.

11 is a bottom perspective view of a first light modulation layer of an optical sheet according to another embodiment of the present invention. 12 is a cross-sectional view taken along the line XII-XII ′ of FIG. 11. 11 and 12, the optical sheet according to the present embodiment illustrates that the height of the main prism 118a of the first light modulation layer 118 may not be constant along the prism extension direction. 11 and 12 illustrate a case in which the height of the main prism 118a becomes smaller as it progresses along the main prism extending direction, but is not limited to this rule. In some embodiments where the main prism 118a is the same width, the smaller the height of the main prism 118a, the larger the vertex angle of the main prism 118a at that location. In the case of the auxiliary prism 118b, such a deformation is possible, of course. When both the height of the primary prism 118a and the height of the secondary prism 118b have various values, the minimum value of the height of the primary prism 118a may be greater than the maximum value of the height of the secondary prism 118b. In some embodiments, the maximum value of the secondary prism 118b height may be less than or equal to half the minimum value of the primary prism 118a height.

FIG. 13 is a bottom perspective view of a first light modulation layer of an optical sheet according to another embodiment of the present invention. FIG. Referring to FIG. 13, the optical sheet according to the present exemplary embodiment illustrates a case in which the extension direction of the main prism 119a of the first light modulation layer 119 is not a straight line but a curve. That is, the main prism 119a may extend with one or more bends. Although not shown, the extension direction of the auxiliary prism 119b may also be a curve rather than a straight line.

14 is a cross-sectional view of an optical sheet according to another embodiment of the present invention. Referring to FIG. 14, a peak portion of the first prism 120a of the first optical modulation layer 120 of the optical sheet 20 according to the present embodiment may be flat. In one variation, the flat peak of the main prism 120a may have a predetermined roughness. In another variation, the peak of the main prism 120a may have an obtuse angle, an acute angle, or a curved surface than the vertex angle of the main prism 120a defined by the peripheral inclined surface. According to the present embodiment, a prism shape that may be applied to the main prism 120a may also be applied to the auxiliary prism 120b.

15 is a cross-sectional view of an optical sheet according to another embodiment of the present invention. Referring to FIG. 15, the optical sheet 21 according to the present embodiment is different from the embodiment of FIG. 2 in that the second light modulation layer 131 is a prism layer 131a. For convenience of description, an example in which an extension direction of the prism 131a of the second light modulation layer 131 is the same as the first direction (X1 in FIG. 1) which is an extension direction of the first light modulation layer 111 and the main prism 111a is shown. Although shown, the extension direction of the prism 131a of the second light modulation layer 131 may have an intersection angle of 90 ° with the first direction (X1 in FIG. 1), or may be the same as the second direction (X2 in FIG. 1). Can be. In some other embodiments, the extending direction of the prism 131a of the second light modulation layer 131 may intersect the first direction X1 at an angle of ± 1 to ± 45 ° or an angle of ± 45 to ± 89 °. have. When the prisms 111a and 111b of the first light modulation layer 111 are inverse prism, the prisms 131a of the second light modulation layer 131 may be positive prisms.

In addition, the shape, size, arrangement, extension direction, etc. of the prism 131a of the second light modulation layer 131 may be variously modified as in the main prisms of the first light modulation layer described with reference to FIGS. 1 to 14. In addition, the second light modulation layer 131 may include an auxiliary prism like the first light modulation layer described above.

16 is a sectional view of an optical sheet according to another embodiment of the present invention. FIG. 16 exemplarily shows that another substrate and / or light modulation layer may be further fixedly bonded to the optical sheet 21 according to the embodiment of FIG. 15. Of course, optical sheets or a combination thereof according to another embodiment may be applied instead of the optical sheet 21 of FIG. 15.

Referring to FIG. 16, the optical sheet 22 according to the present exemplary embodiment further includes a third substrate 300 spaced apart from the upper portion of the first substrate 100. . The third substrate 300 may be fixedly coupled to the second light modulation layer 131. For this, an upper bonding layer 350 may be further formed on the lower surface of the third substrate 300. The upper bonding layer 350 may be formed of an adhesive layer, an adhesive layer, or a resin layer similarly to the bonding layer 250.

The upper coupling layer 350 may be at least partially in contact with the second light modulation layer 131 to fix the second light modulation layer 131 to the third substrate 300. For example, at least a portion of the second light modulation layer 131 may be disposed to penetrate into the upper coupling layer 350. In some other embodiments of the present invention, the upper bonding layer 350 is not formed to completely cover the lower surface of the third substrate 300, but is selectively formed only in the vicinity of the mountain portion of the second light modulation layer 131, thereby partially. The lower surface of the third substrate 300 may be exposed, and the upper bonding layer 350 may completely fill the space between the third substrate 300 and the second light modulation layer 131.

The third light modulation layer 330 may be further formed on the upper surface of the third substrate 300. Although the microlens 330a is illustrated as the third light modulation layer 330 in the drawing, the present invention is not limited thereto.

Furthermore, in the embodiment of FIG. 16, one or more other substrates and / or light modulation layers may be combined in the upper or lower direction of the optical sheet.

17 is a cross-sectional view of an optical sheet according to another embodiment of the present invention. Referring to FIG. 17, the optical sheet 23 may include a first substrate 100, a second substrate 200 spaced apart from the first substrate 100, and a first light formed on an upper surface of the second substrate 200. The modulation layer 211 includes a coupling layer 150 formed on the bottom surface of the first substrate 100 and having the first light modulation layer 211 at least partially coupled thereto. The second light modulation layer 130 may be formed on the upper surface of the first substrate 100. A mat layer 240 or another light modulation layer may be formed on the bottom surface of the second substrate 200.

In the optical sheet 23 according to the present exemplary embodiment, the first light modulation layer 211 is formed on the second substrate 200 instead of the first substrate 100, and the bonding layer 150 is the second substrate 200. The point formed on the lower surface of the first base material 100, which is not the same, is different from the embodiment of FIG. 2. Although the first optical modulation layer 211 includes the main prism 211a and the auxiliary prism 211b is the same as the embodiment of FIG. 2, the formed direction is reversed. Therefore, when the light source is located below the second substrate 200, the first light modulation layer 211 also exhibits a light condensing function as a positive prism. When the main prisms 211a and the auxiliary prisms 211b are applied as the prisms, the vertices of the prisms may be relatively larger than those applied as the inverted prisms. For example, the vertex angles of the primary prism 211a and the secondary prism 211b may be selected from the range of 45 ° to 135 °, the range of 60 ° to 130 °, or the range of 85 ° to 105 °. However, it goes without saying that the present invention is not limited thereto.

The embodiments described above can be combined in various ways. For example, in combination with the embodiment of FIG. 6 and the embodiment of FIG. 17, a first light modulation layer is formed on the second substrate, and a bonding layer is formed on the bottom surface of the first substrate, It is possible to devise an optical sheet in which the pitch of the main prism is not constant. Those skilled in the art will readily appreciate that a wide variety of combinations are possible.

In addition, the above-described optical sheets can be employed in a light source assembly or a liquid crystal display including the same, and can be used to enhance light efficiency. The light source assembly is classified into a direct light source assembly in which the lamp is located at the bottom, an edge light source assembly in which the lamp is located at the side, and the like. The optical sheet according to embodiments of the present invention can be applied to any kind of light source assembly. It is also applicable to a back light assembly disposed below the liquid crystal panel or a front light assembly disposed above the liquid crystal panel. Hereinafter, as an example of various application examples, an optical sheet according to the exemplary embodiment of FIG. 2 is applied to a liquid crystal display including an edge type light source assembly.

18 is a cross-sectional view of a liquid crystal display according to an exemplary embodiment of the present invention.

Referring to FIG. 18, the liquid crystal display 700 includes a backlight assembly 400 and a liquid crystal panel assembly 500.

The backlight assembly 400 includes a light source 410, a light guide plate 420 for guiding light emitted from the light source 410, a reflection film 315 disposed below the light guide plate 420, And an optical sheet 11 arranged to modulate the optical characteristics of the emitted light.

The light source 410 is disposed on both sides of the light guide plate 420. The light source 410 may be a light emitting diode (LED), a cold cathode fluorescent lamp (CCFL), a hot cathode fluorescent lamp (HCFL), or an external electro fluorescent lamp (EEFL). In another embodiment, the light source 410 may be disposed only on one side of the light guide plate 420.

The light guide plate 420 moves the light emitted from the light source 410 through the total internal reflection and emits the light upward through a scattering pattern or the like formed on the lower surface of the light guide plate 420. A reflective film 415 is disposed under the light guide plate 420 to reflect the light emitted downward from the light guide plate 420 to the upper side.

The optical sheet 11 is disposed on the light guide plate 420. Since the optical sheet 11 has been described in detail above, redundant description thereof will be omitted. Other optical sheets may be further disposed above or below the optical sheet 11. For example, a diffusion film for diffusing incident light, a prism sheet for condensing incident light, a liquid crystal film for partially reflecting the incident circularly polarized light, a retardation film for converting circularly polarized light into linearly polarized light, a reflective polarizing film, / Or a protective film may be further provided.

The light source 410, the light guide plate 420, the reflection film 415, and the optical sheet 11 may be received by the bottom chassis 440.

The liquid crystal panel assembly 500 includes a first display panel 511, a second display panel 212 and a liquid crystal layer (not shown) interposed therebetween. The liquid crystal panel assembly 500 includes a first display panel 411 and a second display panel 412 And a polarizing plate (not shown) attached to the surface of the polarizing plate.

The liquid crystal display device 700 may further include a top chassis 500 covering the sides of the liquid crystal panel assembly 500 and the backlight assembly 300 to cover the edges of the liquid crystal panel assembly 500.

The backlight assembly described above can effectively exhibit a plurality of light modulation characteristics even when a relatively small number of substrates are used by applying the optical sheet according to one embodiment of the present invention. Therefore, the thickness of the light source assembly can be reduced, and the assembling process can be simplified. Accordingly, the image quality of a liquid crystal display including such a light source assembly can be improved.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, You will understand. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive.

100: first substrate 111: first optical modulation layer
130: second light modulation layer 200: second substrate
240: mat layer 250: bonding layer

Claims (21)

A first substrate;
A first light modulation layer formed on a lower surface of the first substrate, the first light modulation layer comprising a plurality of main prisms and a plurality of auxiliary prisms having a height smaller than that of the main prisms;
A second substrate disposed spaced apart from the first substrate; And
An optical sheet comprising a bonding layer formed on an upper surface of a second substrate, wherein the main prism is at least partially bonded. The method according to claim 1,
The main prism extends in a first direction,
And the auxiliary prism extends in a second direction crossing the first direction. The method of claim 2,
An optical sheet having a crossing angle of 90 ° in the first direction and the second direction. The method of claim 2,
The first substrate includes a long side and a short side,
And the first and second directions each have an intersection angle of ± 1 to ± 45 ° with the long side or the short side. The method according to claim 1,
And an acid portion of the main prism is arranged to penetrate into the bonding layer. The method according to claim 1,
The auxiliary prism is an optical sheet wherein the acid is spaced apart from the bonding layer. 6. The method of claim 5,
And the minimum value of the height of the auxiliary prism is less than or equal to half the minimum value of the height of the main prism. The method according to claim 1,
The main prism includes a first prism face facing one side of the first substrate and a second prism face facing the other side of the first substrate,
And the inclination angle of the first prism face is greater than the inclination angle of the second prism face. The method according to claim 1,
The optical sheet further comprising a second light modulation layer formed on the upper surface of the first substrate. 10. The method of claim 9,
The second light modulation layer is an optical sheet of a micro lens. The method according to claim 1,
And a mat layer formed on the lower surface of the second substrate. The method according to claim 1,
And a third substrate disposed on the second optical modulation layer and fixedly coupled to the second optical modulation layer. A first substrate;
A second substrate disposed spaced apart from the first substrate;
A first light modulation layer formed on an upper surface of the second substrate, the first light modulation layer including a plurality of main prisms and a plurality of auxiliary prisms having a height smaller than that of the main prisms; And
An optical sheet formed on a bottom surface of a first substrate, the optical sheet including a bonding layer to which the main prism is at least partially bonded. The method of claim 13,
The main prism extends in a first direction,
And the auxiliary prism extends in a second direction crossing the first direction. The method of claim 13,
And an acid portion of the main prism is arranged to penetrate into the bonding layer. The method of claim 13,
The auxiliary prism is an optical sheet wherein the acid is spaced apart from the bonding layer. 17. The method of claim 16,
And the minimum value of the height of the auxiliary prism is less than or equal to half the minimum value of the height of the main prism. The method of claim 13,
The main prism includes a first prism face facing one side of the first substrate and a second prism face facing the other side of the first substrate,
And the inclination angle of the first prism face is greater than the inclination angle of the second prism face. The method of claim 13,
The optical sheet further comprises a second light modulation layer formed on the upper surface of the first substrate and made of a micro lens. 20. A light source assembly comprising the optical sheet according to any one of claims 1 to 19. 20. A liquid crystal display device comprising the optical sheet according to any one of claims 1 to 19.

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