Optical film

Abstract

The present invention relates to an optical film. The optical film according to the present invention comprises, on both surfaces of a prism pattern continuously arranged in a triangular prism shape either in relief or in recess, a first surface and a second surface connected to the first surface at a different angle, wherein the first and second surfaces have protrusions or depressions having lengths of 4.5-12.5 μm formed thereon, the prism has a mountain angle between 60° and 150°, a prism pitch within a range of 30 μm to 100 μm, and an interfacial angle between the first and second surfaces of 90° to 156°. According to the present invention, the optical film may be applied onto a light guide plate or the like used in a liquid crystal display, and by forming an additional prism pattern on the surface of the existing prism pattern, brightness can be increased and the viewing angle can be improved compared with conventional prism sheets.

Description

optical film

[0001] The present invention relates to an optical film, and more particularly, to an optical film that can improve brightness and viewing angle compared to existing films by structuring a prism pattern surface.

[0002] Generally, one of the well-known optical films is called "Brightness Enhancement Film (BEF)" or "Prism Film", which has a good spectral structure formed on a polyester optical film with a thickness of only 50 to 200 microns by curing a special acrylic synthetic resin with high energy ultraviolet light on the polyester optical film. The main function of the Brightness Enhancement Film (BEF) is to collect scattered light that diverges in all directions from the light guide by refraction and total internal reflection, focusing it in a direction of about 35 degrees on the axis, thereby enhancing the brightness of the liquid crystal display.

[0003] In particular, although not shown in the drawing, conventional prism sheets have prism-type mountain-shaped or lens-type hemispherical patterns formed, but these patterns have the problem of limited brightness and viewing angle.

[0004] The present invention has been devised to solve the above-mentioned conventional problems, and its purpose is to provide an optical film that can be grafted onto a light guide plate used in a liquid crystal display device, and that forms a separate prism pattern on the surface of the prism pattern to increase brightness and obtain an improved viewing angle effect compared to a conventional prism sheet.

[0005] In order to achieve the above-described object, the present invention is characterized in that the prism pattern is arranged continuously in a triangular prism shape, and includes a first surface based on the surface and a second surface connected to the first surface at a different angle, and the first and second surfaces each have a protrusion or a depression formed with a length of 4.5 to 12.5 μm, the mountain angle of the prism is formed within 60 to 150°, the prism pitch is formed within a range of 30 to 100 μm, and the angle between the first and second surfaces is 90 to 156°.

[0006] In addition, the present invention is characterized in that the prism pattern is continuously arranged in a triangular prism shape, and includes a first surface based on the surface, a second surface connected to the first surface at a different angle, and a third surface connected to the second surface at a different angle, wherein the first and third surfaces each have a length of 4.5 to 12.5 μm, and the second surface has a length of 1.6 to 10.9 μm, and a protrusion or a depression is formed, respectively, and the mountain angle of the prism is formed within 60 to 150°, the prism pitch is formed within a range of 30 to 100 μm, and the angle between the first and second surfaces and the second and third surfaces is 123 to 145°.

[0007] In addition, the prism pattern in the present invention is characterized in that both surfaces are symmetrical or asymmetrical.

[0008] In addition, the protrusion or depression in the present invention is characterized by being left-right symmetrical or left-right asymmetrical.

[0009] In addition, the top line of the protrusion or the valley line of the recessed part in the present invention is characterized by being formed in a round shape.

[0010] The optical film of the present invention can be grafted onto a light guide plate used in a liquid crystal display device, and by forming separate prism patterns on both surfaces of the prism pattern, it is possible to increase brightness and obtain an improved viewing angle effect compared to a conventional prism sheet.

[0011] FIG. 1 is a drawing illustrating an optical film according to a first embodiment of the present invention.

[0012] Figure 2 is an enlarged view showing the auxiliary prism sizes of the optical film divided into large, medium, and small.

[0013] Figure 3 is a graph showing the brightness and viewing angle when the auxiliary prism size and the number of prism sheets are two.

[0014] Figure 4 is a schematic diagram showing the angle change of the large size among the above auxiliary prism sizes.

[0015] Figure 5 is a graph showing the brightness and viewing angle according to the size of the auxiliary prism in Figure 4.

[0016] Figure 6 is a schematic diagram showing the angle change of the medium size among the auxiliary prism sizes.

[0017] Figure 7 is a graph showing the brightness and viewing angle according to the size of the auxiliary prism in Figure 6.

[0018] Figure 8 is a schematic diagram showing the angle change of a small size among the above auxiliary prism sizes.

[0019] Figure 9 is a graph showing the brightness and viewing angle according to the size of the auxiliary prism in Figure 8.

[0020] FIG. 10 is a drawing illustrating an optical film according to a second embodiment of the present invention.

[0021] Figure 11 is an enlarged view showing the auxiliary prism sizes of the optical film divided into large, medium, and small.

[0022] Figure 12 is a graph showing the brightness and viewing angle when the auxiliary prism size and prism sheet number are two.

[0023] Figure 13 is a schematic diagram showing the angle change of the large size among the auxiliary prism sizes.

[0024] Figure 14 is a graph showing the brightness and viewing angle according to the size of the auxiliary prism in Figure 13.

[0025] Figure 15 is a schematic diagram showing the angle change of the medium size among the above auxiliary prism sizes.

[0026] Figure 16 is a graph showing the brightness and viewing angle according to the size of the auxiliary prism in Figure 15.

[0027] Figure 17 is a schematic diagram showing the angle change of a small size among the above auxiliary prism sizes.

[0028] Figure 18 is a graph showing the brightness and viewing angle according to the size of the auxiliary prism in Figure 17.

[0029] FIG. 19 is a drawing illustrating an optical film according to a third embodiment of the present invention.

[0030] Figure 20 is an enlarged view showing the auxiliary prism sizes of the optical film divided into large, medium, and small.

[0031] Figure 21 is a graph showing the brightness and viewing angle when the auxiliary prism size and prism sheet number are two.

[0032] FIG. 22 is a drawing illustrating an optical film according to a fourth embodiment of the present invention.

[0033] Figure 23 is an enlarged view showing the auxiliary prism sizes of the optical film divided into large, medium, and small.

[0034] Figure 24 is a graph showing the brightness and viewing angle when the auxiliary prism size and prism sheet number are two.

[0035]

[0036] < Explanation of symbols for major parts of the drawing >

[0037] 100: Optical film of the first embodiment 110: Body

[0038] 120: Prism 122: Surface

[0039] 130: Auxiliary prism 132: First surface

[0040] 134: Second surface

[0041] 200: Optical film of the second embodiment 210: Body

[0042] 220: Prism 222: Surface

[0043] 230: Auxiliary prism 232: First surface

[0044] 234: Second surface 236: Third surface

[0045] 300: Optical film of the third embodiment 310: Body

[0046] 320: Prism 322: Surface

[0047] 330: Auxiliary prism 332: First surface

[0048] 334: Second surface

[0049] 400: Optical film of the fourth embodiment 410: Body

[0050] 420: Prism 422: Surface

[0051] 430: Auxiliary prism 432: First surface

[0052] 434: Second surface 436: Third surface

[0053] Hereinafter, the optical film of the present invention will be described with reference to the attached drawings as examples.

[0054]

[0055] < Example 1 >

[0056] The optical film (100) according to the present embodiment includes a body (110), a prism (120), and an auxiliary prism (130) as shown in FIG. 1.

[0057] The body (110) has one side wall as a light incident surface and the incident light is emitted through the upper surface (surface) as a light emitting surface in the process of being scattered, and a light source (not shown in the drawing) such as a cold cathode fluorescent lamp (CCFL) or a light emitting diode (LED) is installed on one or both side walls of the body (110). In particular, when the light source is a light emitting diode, the light is incident in a point shape and emitted in a surface shape.

[0058] Prisms (120) are arranged in a continuous manner with a triangular prism-shaped pattern on the top of the body (110), and are formed in large numbers to have a set size, groove depth, pitch (P) and outer angle (θ) to collect light irradiated from a light source (not shown in the drawing) and finely pattern it to improve brightness.

[0059] Here, the prism (120) is exemplified as a protrusion with symmetrical surfaces (122) in this embodiment, and an auxiliary prism (130) is integrally formed on both surfaces (122). At this time, the prism (120) is exemplified as being symmetrical on both sides and having a top line formed on the prism mountain, but an asymmetrical shape is also possible, and it is also possible to change the prism mountain to be formed into a curved surface with a set radius.

[0060] And it is preferable that the prism (120) pitch (P) is formed within a range of 30 to 100 μm, and it is preferable that the internal angle (θ), which is the mountain angle, is formed within a range of 60 to 150°.

[0061] The auxiliary prism (130) is formed of a first surface (132) based on the surface (122) of the prism (120) and a second surface (134) connected to the first surface (132) at a different angle to form a protruding triangular prism shape.

[0062] At this time, the first surface (132) and the second surface (134) forming the auxiliary prism (130) are exemplified as being symmetrical left and right with respect to the surface (122), but the left and right asymmetry can also be changed. In addition, the angle (θ1) between the first surface (132), which is a horizontal plane, and the second surface (134), which is a vertical plane, is characterized by being 90 to 156°.

[0063] Meanwhile, the distance from the top of the prism (120) to the starting point of the first surface (132) of the auxiliary prism (130) is referred to as (L1), the length of the first surface (132) is referred to as (L2), and the length of the second surface (134) is referred to as (L3).

[0064]

[0065] Hereinafter, in the auxiliary prism (130) that doubles the effect of the prism (120) by improving brightness and improving the viewing angle, when two prism sheets (bef) are applied (vertical, horizontal), the brightness and viewing angle according to the angle between the first surface (132) and the second surface (134) and the length of the first surface (132) and the second surface (134) will be described.

[0066] Here, the auxiliary prism (130) can be classified into large, medium (basic), and small according to the angle (θ1) between the first surface (132) and the second surface (134), the pitch (P) of the prism (120), and the lengths (L2, L3) between the first surface (132) and the second surface (134), as shown in FIGS. 2a, 2b, and 2c. In this case, the angle (θ1) between the first surface (132) and the second surface (134) is 90°.

[0067] In the case of a large size, the distance (L1) from the top of the prism (120) to the starting point of the first surface (132) of the auxiliary prism (130) is 8.8 μm, the angles (θ2, θ3) of the first surface (132) and the second surface (134) based on the two surfaces (122) of the prism (120) are each 135°, the angle (θ1) between the first surface (132) and the second surface (134) is 90°, the lengths (L2, L3) of the first and second surfaces (132, 134) are each 12.5 μm, and the pitch (P) of the prism (120) is specified as 12.5 μm. (See Fig. 2a)

[0068] In the case of a medium size, the distance (L1) from the top of the prism (120) to the starting point of the first surface (132) of the auxiliary prism (130) is 13.3 μm, the angles (θ2, θ3) of the first surface (132) and the second surface (134) based on the two surfaces (122) of the prism (120) are each 135°, the angle (θ1) between the first surface (132) and the second surface (134) is 90°, the lengths (L2, L3) of the first and second surfaces (132, 134) are each 6.3 μm, and the pitch (P) of the prism (120) is specified as 18.8 μm. (See Fig. 2b)

[0069] Finally, in the case of a small size, the distance (L1) from the top of the prism (120) to the starting point of the first surface (132) of the auxiliary prism (130) is 15.5 μm, the angles (θ2, θ3) of the first surface (132) and the second surface (134) based on the two surfaces (122) of the prism (120) are each 135°, the angle (θ1) between the first surface (132) and the second surface (134) is 90°, the lengths (L2, L3) of the first and second surfaces (132, 134) are each 4.7 μm, and the pitch (P) of the prism (120) is specified as 18.8 μm. (See Fig. 2c)

[0070] In this way, when 2 prism sheets (bef) are applied (vertical, horizontal) and simulation is performed based on the large, medium, and small sizes of the auxiliary prism (130), the luminance values ​​in Table 1 below and the viewing angles in Tables 2 and 3 can be obtained.

[0071] Prism shape 1. Shape 2. Shape 3. Shape 4. Luminance value based on 90 degrees 2177525357252542409423498

[0072] Prism shape 1. Shape 2. Shape 3. 6837. Shape 4. 129 degrees standard luminance value 6268695852368377434

[0073] Prism shape 1. Shape 2. Shape 3. Shape 4. Luminance value based on 50 degrees 5448128869967277850

[0074]

[0075] Finally, through Tables 1, 2, 3 and FIG. 3, it can be seen that when the lengths (L2, L3) of the first surface (132) and the second surface (134) are 12.5 ㎛ and the angle (θ1) between the first surface (132) and the second surface (134) is 90°, the luminance value based on the prism sheet (bef) is at the same level as when there are two sheets (vertical, horizontal), and that as the lengths (L2, L3) of the first surface (132) and the second surface (134) become smaller, the luminance value based on the 90° increases. In particular, it can be seen that the luminance value based on the 90° increases when the lengths (L2, L3) of the first surface (132) and the second surface (134) are simulated to be 4.7 ㎛ or less, which is a small-sized auxiliary prism (130).

[0076]

[0077] Next, in the auxiliary prism (130) that doubles the brightness enhancement and viewing angle improvement effect, when the angle (θ1) between the first surface (132) and the second surface (134) is 156°, the brightness and viewing angle will be described. At this time, the first surface (132) and the second surface (134) form a diagonal line.

[0078] The auxiliary prism (130) can be classified into large, medium (basic), and small according to the angle (θ1) between the first surface (132) and the second surface (134), the pitch (P) of the prism (120), and the lengths (L2, L3) of the first surface (132) and the second surface (134), as shown in FIGS. 4 to 9.

[0079] In the case of a large size, as shown in FIGS. 4 and 5, the distance (L1) from the top of the prism (120) to the starting point of the first surface (132) of the auxiliary prism (130) is 8.8 μm, the angles (θ2, θ3) of the first surface (132) and the second surface (134) based on the two surfaces (122) of the prism (120) are each 168°, the angle (θ1) between the first surface (132) and the second surface (134) is 156°, the lengths (L2, L3) of the first and second surfaces (132, 134) are each 8.8 μm, and the pitch (P) of the prism (120) is specified as 12.5 μm.

[0080] In the case of medium size, as shown in FIGS. 6 and 7, the distance (L1) from the top of the prism (120) to the starting point of the first surface (132) of the auxiliary prism (130) is 13.3 μm, the angles (θ2, θ3) of the first surface (132) and the second surface (134) based on the two surfaces (122) of the prism (120) are each 168°, the angle (θ1) between the first surface (132) and the second surface (134) is 156°, the lengths (L2, L3) of the first and second surfaces (132, 134) are each 4.5 μm, and the pitch (P) of the prism (120) is specified as 18.8 μm.

[0081] Finally, for the small size, as shown in FIGS. 8 and 9, the distance (L1) from the top of the prism (120) to the starting point of the first surface (132) of the auxiliary prism (130) is 15.5 μm, the angles (θ2, θ3) of the first surface (132) and the second surface (134) based on the two surfaces (122) of the prism (120) are each 168°, the angle (θ1) between the first surface (132) and the second surface (134) is 156°, the lengths (L2, L3) of the first and second surfaces (132, 134) are each 3.4 μm, and the pitch (P) of the prism (120) is specified as 18.8 μm.

[0082] In this way, when 2 prism sheets (bef) are applied (vertical, horizontal) and the simulation is performed based on the large, medium, and small sizes of the auxiliary prism (130), it can be seen that the angle having the same or higher data value as the prism film is MAX 90° and MIN 156°. (See FIGS. 5, 7, and 9)

[0083]

[0084] < Example 2 >

[0085] The optical film (200) according to the present embodiment includes a body (210), a prism (220), and an auxiliary prism (230) as illustrated in FIG. 10.

[0086] The body (210) has one side wall as a light incident surface and the incident light is emitted through the upper surface (surface) as a light emitting surface in the process of being scattered, and a light source (not shown in the drawing) such as a cold cathode fluorescent lamp (CCFL) or a light emitting diode (LED) is installed on one or both side walls of the body (210). In particular, when the light source is a light emitting diode, the light is incident in a point shape and emitted in a surface shape.

[0087] Prisms (220) are arranged in a continuous manner with a triangular prism-shaped pattern on the top of the body (210), and are formed in large numbers to have a set size, groove depth, pitch (P), and outer angle (θ) to collect light irradiated from a light source (not shown in the drawing) and finely pattern it to improve brightness.

[0088] Here, the prism (220) is exemplified as a protrusion with symmetrical surfaces (222) in this embodiment, and an auxiliary prism (230) is integrally formed on both surfaces (222). At this time, the prism (220) is exemplified as being symmetrical on both sides and having a top line formed on the prism mountain, but an asymmetrical shape is also possible, and it is also possible to change the prism mountain to be formed into a curved surface with a set radius.

[0089] And it is preferable that the prism (220) pitch (P) is formed within a range of 30 to 100 μm, and it is preferable that the internal angle (θ), which is the mountain angle, is formed within a range of 60 to 150°.

[0090] The auxiliary prism (230) is formed of a first surface (232) based on the surface (222) of the prism (220), a second surface (234) connected to the first surface (232) at a different angle, and a third surface (236) connected to the second surface (234) at a different angle, forming a protruding trapezoidal column shape.

[0091] At this time, the first surface (232) and the third surface (236) forming the auxiliary prism (230) are exemplified as being symmetrical left and right with respect to the surface (222), but the left and right asymmetry can also be changed. In addition, the angle (θ1) between the first surface (232), which is a horizontal plane, and the second surface (134), which is an inclined plane, and the angle (θ1) between the second surface (234), which is an inclined plane, and the third surface (236), which is a vertical plane, are characterized by being 123 to 145°.

[0092] Meanwhile, the distance from the top of the prism (220) to the starting point of the first surface (232) of the auxiliary prism (230) is referred to as (L1), the length of the first surface (232) and the length of the third surface (236) are each referred to as (L2), the length of the third surface (236) is referred to as (L3), and the length from the end point of the third surface (236) to the bottom of the surface (222) is referred to as (L4).

[0093]

[0094] Hereinafter, in the auxiliary prism (230) that doubles the effect of the prism (220) by improving brightness and improving the viewing angle, when two prism sheets (bef) are applied (vertical, horizontal), the brightness and viewing angle according to the angle between the first surface (232) and the second surface (234) and the second surface (234) and the third surface (236) and the length of the first surface (232), the second surface (234) and the third surface (236) will be described.

[0095] Here, the auxiliary prism (230) can be classified into large, medium (basic), and small according to the angle (θ1) between the first surface (232) and the second surface (234), and the second surface (234) and the third surface (236), the pitch (P) of the prism (220), and the lengths (L2, L3) of the first surface (232), the second surface (234), and the third surface (236), as illustrated in FIGS. 11a, 11b, and 11c. In this case, the angle (θ1) between the first surface (232) and the second surface (234), and the second surface (234) and the third surface (236) is 135°.

[0096] In the case of a large size, the distance (L1) from the top of the prism (220) to the starting point of the first surface (232) of the auxiliary prism (230) is 4.4 μm, the angles (θ2, θ3) of the first surface (232) and the third surface (236) based on the two surfaces (222: L1, L4) of the prism (220) are each 135°, the angles (θ1) between the first surface (232) and the second surface (234) and between the second surface (234) and the third surface (236) are each 135°, the lengths (L2) of the first and third surfaces (232, 236) are each 12.5 μm, the length (L3) of the second surface (234) is 8.8 μm, and the pitch (P) of the prism (220) is specified as 63 μm. (See Fig. 11a)

[0097] In the case of medium size, the distance (L1) from the top of the prism (220) to the starting point of the first surface (232) of the auxiliary prism (230) is 8.8 μm, the angles (θ2, θ3) of the first surface (232) and the third surface (236) based on the two surfaces (222) of the prism (220) are each 135°, the angles (θ1) between the first surface (232) and the second surface (234) and between the second surface (234) and the third surface (236) are each 135°, the lengths (L2) of the first and third surfaces (232, 236) are each 8.8 μm, the length (L3) of the second surface (234) is 8.8 μm, and the length (L4) from the end point of the third surface (236) to the bottom of the surface (222) is 8.8 μm. The prism (220) pitch (P) is specified as 12.5㎛. (See Fig. 11b)

[0098] Finally, in the case of the small size, the distance (L1) from the top of the prism (220) to the starting point of the first surface (232) of the auxiliary prism (230) is 15.5 μm, the angles (θ2, θ3) of the first surface (232) and the third surface (236) based on the two surfaces (222) of the prism (220) are each 135°, the angles (θ1) between the first surface (232) and the second surface (234) and between the second surface (234) and the third surface (236) are each 135°, the lengths (L2) of the first and third surfaces (232, 236) are each 4.7 μm, the length (L3) of the second surface (234) is 4.4 μm, and the length (L4) from the end point of the third surface (236) to the bottom of the surface (222) is 8.8 μm. The prism (220) pitch (P) is specified as 12.5㎛. (See Fig. 11c)

[0099] In this way, when 2 prism sheets (bef) are applied (vertical, horizontal) and simulation is performed based on the large, medium, and small sizes of the auxiliary prism (230), the luminance values ​​in Table 4 below and the viewing angles in Tables 5 and 6 can be obtained.

[0100] Luminance value based on 90 degrees of prism large, medium, and small: 21775236692525425797

[0101] Luminance value based on 129 degrees for prism large, medium, and small: 6261078685237023

[0102] Luminance value based on 50 degrees of prism size: 5441064986996860

[0103]

[0104] Finally, through Tables 4, 5, 6 and FIG. 12, it can be seen that when the length (L2) of the first surface (232) and the third surface (236) is 12.5 ㎛ and the angle (θ1) between the first surface (232) and the second surface (234) and the second surface (234) and the third surface (236) is 90°, the luminance value based on the prism sheet (bef) is at the same level as when there are two sheets (vertical, horizontal), and as the lengths (L2, L3) of the first surface (132) and the third surface (134) become smaller, the luminance value based on the 90° increases. In particular, it can be seen that when the length (L2) of the first surface (232) and the third surface (234) is simulated to be 4.7 ㎛ or less, which is a small-sized auxiliary prism (230), the luminance value based on the 90° increases.

[0105]

[0106] Next, in the auxiliary prism (230) that doubles the brightness enhancement and viewing angle improvement effect, when the angle (θ1) between the first surface (232) and the second surface (234) and the second surface (234) and the third surface (236) is 156°, the brightness and viewing angle will be described. At this time, the first surface (232) and the second surface (234) form an oblique line.

[0107] The auxiliary prism (230) can be classified into large, medium (basic), and small according to the angle (θ1) between the first surface (232) and the second surface (234) and the second surface (234) and the third surface (236), the pitch (P) of the prism (220), and the lengths (L2, L3) of the first surface (232), the third surface (236), and the second surface (234), as shown in FIGS. 13 to 18.

[0108] In the case of a large size, as illustrated in FIGS. 13 and 14, when the angle (θ1) between the first surface (232) and the second surface (234) and the second surface (234) and the third surface (236) is 123° and 127°, for example, first, when the angle (θ1) is 123°, as illustrated in FIG. 13b, the distance (L1) from the top of the prism (220) to the starting point of the first surface (232) of the auxiliary prism (230) is 7.6 μm, and the angles (θ2, θ3) between the first surface (232) and the third surface (236) based on the two surfaces (222: L1, L4) of the prism (220) are each 123°, and the angles between the first surface (232) and the second surface (234) and the second surface (234) and the third surface (236) are 123°. The angle (θ1) between the surfaces (236) is 123° each, the lengths (L2) of the first and third surfaces (232, 236) are 10.5 µm each, the length (L4) from the end point of the third surface (236) to the bottom of the surface (222) is 8.8 µm, and the length (L3) of the second surface (234) is 7.5 µm.

[0109] Next, when the angle (θ1) between is 127°, as shown in FIG. 13b, the distance (L1) from the top of the prism (220) to the starting point of the first surface (232) of the auxiliary prism (230) is 7.6 μm, and the angles (θ2, θ3) between the first surface (232) and the third surface (236) based on the two surfaces (222: L1, L4) of the prism (220) are each 127°, and the angles (θ1) between the first surface (232) and the second surface (234) and the second surface (234) and the third surface (236) are each 127°, and the lengths (L2) of the first and third surfaces (232, 236) are each 11.1 μm, the length (L3) of the second surface (234) is 6.9 μm, and the second The length (L3) of the surface (234) is specified as 7.5㎛.

[0110] In the case of medium size, as shown in FIGS. 15 and 16, when the angle (θ1) between the first surface (232) and the second surface (234) and the second surface (234) and the third surface (236) is 99° and 145°, for example, first, when the angle (θ1) is 99°, as shown in FIG. 15c, the distance (L1) from the top of the prism (220) to the starting point of the first surface (232) of the auxiliary prism (230) is 8.8 μm, and the angles (θ2, θ3) between the first surface (232) and the third surface (236) based on the two surfaces (222) of the prism (220) are each 99°, and the angles between the first surface (232) and the second surface (234) and the second surface (234) and the third surface (236) are Each angle (θ1) is 99°, the lengths (L2) of the first and third surfaces (232, 236) are each 4.5 μm, the length (L3) of the second surface (234) is 11.9 μm, and the length (L4) from the end point of the third surface (236) to the bottom of the surface (222) is specified as 13.3 μm.

[0111] Next, when the angle (θ1) between is 145°, as shown in FIG. 15b, the distance (L1) from the top of the prism (220) to the starting point of the first surface (232) of the auxiliary prism (230) is 8.8 μm, and the angles (θ2, θ3) between the first surface (232) and the third surface (236) based on the two surfaces (222) of the prism (220) are each 145°, and the angles (θ1) between the first surface (232) and the second surface (234) and the second surface (234) and the third surface (236) are each 145°, and the lengths (L2) of the first and third surfaces (232, 236) are each 7.7 μm, the length (L3) of the second surface (234) is 5.1 μm, and from the end point of the third surface (236) The length (L4) to the bottom of the surface (222) is specified as 8.8㎛.

[0112] Finally, in the case of the small size, as shown in FIGS. 17 and 18, when the angle (θ1) between the first surface (232) and the second surface (234) and the second surface (234) and the third surface (236) is 99° and 145°, for example, first, when the angle (θ1) is 99°, as shown in FIG. 17c, the distance (L1) from the top of the prism (220) to the starting point of the first surface (232) of the auxiliary prism (230) is 15.5 μm, and the angles (θ2, θ3) of the first surface (232) and the third surface (236) based on the two surfaces (222) of the prism (220) are each 99°, and the angles (θ2, θ3) between the first surface (232) and the second surface (234) and the second surface (234) and the third surface (236) are 99°. The angles (θ1) between the first and third surfaces (232, 236) are each 99°, the lengths (L2) of the first and third surfaces (232, 236) are each 3.4 μm, the length (L3) of the second surface (234) is 10 μm, and the length (L4) from the end point of the third surface (236) to the bottom of the surface (222) is specified as 8.8 μm.

[0113] Next, when the angle (θ1) between is 145°, as shown in FIG. 17b, the distance (L1) from the top of the prism (220) to the starting point of the first surface (232) of the auxiliary prism (230) is 15.5 μm, and the angles (θ2, θ3) between the first surface (232) and the third surface (236) based on the two surfaces (222) of the prism (220) are each 145°, and the angles (θ1) between the first surface (232) and the second surface (234) and the second surface (234) and the third surface (236) are each 145°, and the lengths (L2) of the first and third surfaces (232, 236) are each 5.8 μm, the length (L3) of the second surface (234) is 1.6 μm, and from the end point of the third surface (236) The length (L4) to the bottom of the surface (222) is specified as 8.8㎛.

[0114] In this way, when 2 prism sheets (bef) are applied (vertical, horizontal) and the simulation is performed based on the large, medium, and small sizes of the auxiliary prism (230), it can be seen that the angle having the same or higher data value as the prism film is MAX 145° and MIN 99°. (See FIGS. 14, 16, and 18)

[0115]

[0116] < Example 3 >

[0117] The optical film (300) according to the present embodiment includes a body (310), a prism (320), and an auxiliary prism (330) as illustrated in FIG. 19.

[0118] The body (310) has one side wall as a light incident surface and the incident light is emitted through the upper surface (surface) as a light emitting surface in the process of being scattered, and a light source (not shown in the drawing) such as a cold cathode fluorescent lamp (CCFL) or a light emitting diode (LED) is installed on one or both side walls of the body (310). In particular, when the light source is a light emitting diode, it is incident in a point shape and emitted in a surface shape.

[0119] Prisms (320) are arranged in a continuous manner with a triangular prism-shaped pattern engraved on the top of the body (310), and are formed in large numbers to have a set size, groove depth, pitch (P), and outer angle (θ) to collect light irradiated from a light source (not shown in the drawing) and finely pattern it to improve brightness.

[0120] Here, the prism (320) is exemplified as a recessed portion with symmetrical surfaces (322) in this embodiment, and an auxiliary prism (330) is integrally formed on both surfaces (322). At this time, the prism (320) is exemplified as being symmetrical on both sides and having a groove line formed at the prism groove, but an asymmetrical shape is also possible, and it is also possible to change and implement the prism groove to be formed into a curved surface with a set radius.

[0121] And it is preferable that the prism (320) pitch (P) is formed within a range of 30 to 100 μm, and it is preferable that the internal angle (θ), which is the mountain angle, is formed within a range of 60 to 150°.

[0122] The auxiliary prism (330) is formed of a first surface (332) based on the surface (322) of the prism (320) and a second surface (334) connected to the first surface (332) at a different angle to form a sunken triangular prism shape.

[0123] At this time, the first surface (332) and the second surface (334) forming the auxiliary prism (330) are exemplified as being symmetrical left and right with respect to the surface (322), but the left and right asymmetry can also be changed. In addition, the angle (θ1) between the first surface (332), which is a horizontal plane, and the second surface (334), which is a vertical plane, is characterized by being 90 to 156°.

[0124] Meanwhile, the distance from the bone line of the prism (320) to the starting point of the first surface (332) of the auxiliary prism (330) is referred to as (L1), the length of the first surface (332) is referred to as (L2), the length of the second surface (134) is referred to as (L3), and the distance from the end of the second surface (334) to the top of the mountain is referred to as (L4).

[0125]

[0126] Hereinafter, in the auxiliary prism (330) that doubles the effect of the prism (320) by improving brightness and improving the viewing angle, when two prism sheets (bef) are applied (vertical, horizontal), the brightness and viewing angle according to the angle between the first surface (332) and the second surface (334) and the length of the first surface (332) and the second surface (334) will be described.

[0127] Here, the auxiliary prism (330) can be classified into large, medium (basic), and small according to the angle (θ1) between the first surface (332) and the second surface (334), the pitch (P) of the prism (320), and the lengths (L2, L3) between the first surface (332) and the second surface (334), as illustrated in FIGS. 20a, 20b, and 20c. In this case, the angle (θ1) between the first surface (332) and the second surface (334) is 90°.

[0128] In the case of a large size, the distance (L1) from the top of the prism (320) to the starting point of the first surface (332) of the auxiliary prism (330) is 8.8 μm, the angles (θ2, θ3) of the first surface (332) and the second surface (334) based on the two surfaces (322) of the prism (320) are each 135°, the angle (θ1) between the first surface (332) and the second surface (334) is 90°, the lengths (L2, L3) of the first and second surfaces (332, 334) are each 12.5 μm, and the pitch (P) of the prism (320) is specified as 12.5 μm. (See Fig. 20a)

[0129] In the case of a medium size, the distance (L1) from the top of the prism (320) to the starting point of the first surface (332) of the auxiliary prism (330) is 13.3 μm, the angles (θ2, θ3) of the first surface (332) and the second surface (334) based on the two surfaces (322) of the prism (320) are each 135°, the angle (θ1) between the first surface (332) and the second surface (334) is 90°, the lengths (L2, L3) of the first and second surfaces (332, 334) are each 6.3 μm, and the pitch (P) of the prism (320) is specified as 18.8 μm. (See Fig. 20b)

[0130] Finally, in the case of a small size, the distance (L1) from the top of the prism (320) to the starting point of the first surface (332) of the auxiliary prism (330) is 15.5 μm, the angles (θ2, θ3) of the first surface (332) and the second surface (334) based on the two surfaces (322) of the prism (320) are each 135°, the angle (θ1) between the first surface (332) and the second surface (334) is 90°, the lengths (L2, L3) of the first and second surfaces (332, 334) are each 4.7 μm, and the pitch (P) of the prism (320) is specified as 21.9 μm. (See Fig. 20c)

[0131] In this way, when 2 prism sheets (bef) are applied (vertical, horizontal) and simulation is performed based on the large, medium, and small sizes of the auxiliary prism (330), the luminance values ​​in Table 1 below and the viewing angles in Tables 2 and 3 can be obtained.

[0132] Luminance value based on 90 degrees of prism size: 21775216942409424126

[0133] Luminance value based on 129 degrees for prism large, medium, and small: 6261061568375785

[0134] Luminance value based on 50 degrees of prism size: 5441006162275483

[0135]

[0136] Finally, through Tables 1, 2, 3 and FIG. 21, it can be seen that when the lengths (L2, L3) of the first surface (332) and the second surface (334) are 12.5 ㎛ and the angle (θ1) between the first surface (332) and the second surface (334) is 90°, the luminance value based on the prism sheets (bef) is at the same level as when there are two (vertical, horizontal) sheets, and that as the lengths (L2, L3) of the first surface (332) and the second surface (334) become smaller, the luminance value based on the 90° increases. In particular, it can be seen that the luminance value based on the 90° increases when the lengths (L2, L3) of the first surface (132) and the second surface (134) are simulated to be 4.7 ㎛ or less, which is a small-sized auxiliary prism (330).

[0137]

[0138] < Example 4 >

[0139] The optical film (400) according to the present embodiment includes a body (410), a prism (420), and an auxiliary prism (430) as illustrated in FIG. 22.

[0140] The body (410) has one side wall as a light incident surface and the incident light is emitted through the upper surface (surface) as a light emitting surface in the process of being scattered, and a light source (not shown in the drawing) such as a cold cathode fluorescent lamp (CCFL) or a light emitting diode (LED) is installed on one or both side walls of the body (410). In particular, when the light source is a light emitting diode, the light is incident in a point shape and emitted in a surface shape.

[0141] Prisms (420) are arranged in a continuous manner with a triangular prism-shaped pattern engraved on the top of the body (410), and are formed in large numbers to have a set size, groove depth, pitch (P), and outer angle (θ) to collect light irradiated from a light source (not shown in the drawing) and finely pattern it to improve brightness.

[0142] Here, the prism (420) is exemplified as a recessed portion with symmetrical surfaces (422) in this embodiment, and an auxiliary prism (430) is integrally formed on both surfaces (422). At this time, the prism (420) is exemplified as being symmetrical on both sides and having a groove line formed at the prism groove, but an asymmetrical shape is also possible, and it is also possible to change and implement the prism groove to be formed into a curved surface with a set radius.

[0143] And it is preferable that the prism (420) pitch (P) is formed within a range of 30 to 100 μm, and it is preferable that the internal angle (θ), which is the mountain angle, is formed within a range of 60 to 150°.

[0144] The auxiliary prism (430) is formed of a first surface (432) based on the surface (422) of the prism (420), a second surface (434) connected to the first surface (432) at a different angle, and a third surface (436) connected to the second surface (434) at a different angle, forming a sunken trapezoidal column shape.

[0145] At this time, the first surface (432) and the third surface (436) forming the auxiliary prism (430) are exemplified as being symmetrical left and right with respect to the surface (422), but the left and right asymmetry can also be changed. In addition, the angle (θ1) between the first surface (432), which is a horizontal plane, and the second surface (434), which is an inclined plane, and the angle (θ1) between the second surface (434), which is an inclined plane, and the third surface (436), which is a vertical plane, are characterized by being 123 to 145°.

[0146] Meanwhile, the distance from the bone line of the prism (420) to the starting point of the first surface (432) of the auxiliary prism (430) is referred to as (L1), the length of the first surface (432) and the length of the third surface (436) are each referred to as (L2), the length of the third surface (436) is referred to as (L3), and the length from the end point of the third surface (436) to the top of the mountain is referred to as (L4).

[0147]

[0148] Hereinafter, in the auxiliary prism (430) that doubles the effect of the prism (420) by improving brightness and improving the viewing angle, when two prism sheets (bef) are applied (vertical, horizontal), the brightness and viewing angle according to the angle between the first surface (432) and the second surface (434) and the second surface (434) and the third surface (436) and the length of the first surface (432), the second surface (434) and the third surface (436) will be described.

[0149] Here, the auxiliary prism (430) can be classified into large, medium (basic), and small according to the angle (θ1) between the first surface (432) and the second surface (434), and the second surface (434) and the third surface (436), the pitch (P) of the prism (420), and the lengths (L2, L3) of the first surface (432), the second surface (434), and the third surface (436), as illustrated in FIGS. 23a, 23b, and 23c. In this case, the angle (θ1) between the first surface (432) and the second surface (434), and the second surface (434) and the third surface (436) is 135°.

[0150] In the case of a large size, the distance (L1) from the bone line of the prism (420) to the starting point of the first surface (432) of the auxiliary prism (430) is 4.4 μm, the angles (θ2, θ3) of the first surface (432) and the third surface (436) based on the two surfaces (422: L1, L4) of the prism (420) are each 135°, the angles (θ1) between the first surface (432) and the second surface (434) and between the second surface (434) and the third surface (436) are each 135°, the lengths (L2) of the first and third surfaces (432, 436) are each 10.9 μm, the length (L3) of the second surface (434) is 11 μm, and the length (L4) from the end point of the third surface (436) to the top of the surface (422) is It is 4.4㎛, and the prism (220) pitch (P) is specified as 21.9㎛. (See Fig. 23a)

[0151] In the case of medium size, the distance (L1) from the bone line of the prism (420) to the starting point of the first surface (432) of the auxiliary prism (430) is 8.8 ㎛, the angles (θ2, θ3) of the first surface (432) and the third surface (436) based on the two surfaces (422) of the prism (420) are each 135°, the angles (θ1) between the first surface (432) and the second surface (434) and between the second surface (434) and the third surface (436) are each 135°, the lengths (L2) of the first and third surfaces (432, 436) are each 6.3 ㎛, the length (L3) of the second surface (434) is 8.8 ㎛, and the length (L4) from the end point of the third surface (436) to the top of the surface (422) is 8.8 ㎛. The prism (420) pitch (P) is specified as 21.9㎛. (See Fig. 23b)

[0152] Finally, in the case of the small size, the distance (L1) from the bone line of the prism (420) to the starting point of the first surface (432) of the auxiliary prism (430) is 15.5 μm, the angles (θ2, θ3) of the first surface (432) and the third surface (436) based on the two surfaces (422) of the prism (420) are each 135°, the angles (θ1) between the first surface (432) and the second surface (434) and between the second surface (434) and the third surface (436) are each 135°, the lengths (L2) of the first and third surfaces (432, 436) are each 4.7 μm, the length (L3) of the second surface (434) is 4.4 μm, and the length (L4) from the end point of the third surface (436) to the top of the surface (422) is 8.8 μm. The prism (420) pitch (P) is specified as 12.5㎛. (See Fig. 23c)

[0153] In this way, when 2 prism sheets (bef) are applied (vertical, horizontal) and simulation is performed based on the large, medium, and small sizes of the auxiliary prism (430), the luminance values ​​in Table 10 below and the viewing angles in Tables 11 and 12 can be obtained.

[0154] Luminance value based on 90 degrees of prism size: 21775226092349823733

[0155] Luminance value based on 129 degrees for prism large, medium, and small: 6261126274346443

[0156] Luminance value based on 50 degrees of prism size: 5441171478506287

[0157]

[0158] Finally, through Tables 10, 11, 12 and FIG. 24, it can be seen that when the length (L2) of the first surface (432) and the third surface (436) is 12.5 ㎛, the 90° reference luminance value is at the same level as when there are two prism sheets (bef) (vertical, horizontal), and that as the lengths (L2, L3) of the first surface (132) and the third surface (134) become smaller, the 90° reference luminance value increases. In particular, it can be seen that the 90° reference luminance value increases when the length (L2) of the first surface (332) and the third surface (334) is simulated to be 4.7 ㎛ or less, which is a small-sized auxiliary prism (330).

[0159]

[0160] Although the detailed description of the present invention described above has been described with reference to preferred embodiments of the present invention, the scope of protection of the present invention is not limited to the above embodiments, and it will be understood that a person having ordinary knowledge in the relevant technical field can modify and change the present invention in various ways without departing from the spirit and technical scope of the present invention.

Claims

1. A prism pattern that is continuously arranged in the shape of a triangular prism and is either raised or lowered; Including an auxiliary prism formed integrally on both surfaces of the prism pattern and including a first surface and a second surface connected to the first surface at an angle of 90 to 156°, The lengths (L2, L3) of the first and second surfaces are 4.5 to 12.5 μm, The angle between the two surfaces of the above prism pattern is 60 to 150°, An optical film characterized in that the pitch of the above prism pattern is 30 to 100 μm.

2. A prism pattern that is continuously arranged in the shape of a triangular prism and is either raised or lowered; Including an auxiliary prism formed integrally on both surfaces of the prism pattern, including a first surface and a second surface connected to the first surface at an angle of 123 to 145°, and a third surface connected to the second surface at an angle of 123 to 145°, The length (L2) of the first and third surfaces is 4.5 to 12.5 μm, and the length (L3) of the second surface is 1.6 to 10.9 μm. The angle between the two surfaces of the above prism pattern is 60 to 150°, An optical film characterized in that the pitch of the above prism pattern is 30 to 100 μm.

3. In paragraph 1 or 2, An optical film characterized in that the above prism pattern has both surfaces that are symmetrical or asymmetrical.

4. In paragraph 1 or 2, An optical film characterized in that the auxiliary prism is symmetrical or asymmetrical.

5. In paragraph 1 or 2, An optical film characterized in that the top line or valley line of the auxiliary prism is formed in a round shape.

Images