WO2008038920A1

WO2008038920A1 - Optical film and display device comprising the same

Info

Publication number: WO2008038920A1
Application number: PCT/KR2007/004468
Authority: WO
Inventors: Yong-Shig Shim; Jeong-Ho Park
Original assignee: Lgs Co., Ltd.
Priority date: 2006-09-29
Filing date: 2007-09-17
Publication date: 2008-04-03
Also published as: KR100703953B1

Abstract

The present invention discloses an optical film. An optical film of the present invention comprises micro-shaped optical patterns formed on at least one surface thereof, each optical pattern has a peak and comprises defect-correcting structures formed thereon, and the defect- correcting structure is formed in areas within a height range of 30 or 40% from the peak based on the height of the optical pattern. The defect-correcting structures are one of the groups consisting of micro prominences, depressions, micro scratches, and burrs, and each of the optical patterns has any one sectional shape of a triangular shape, a polygonal shape and an arc shape. Also, the optical patterns are disposed in parallel and spaced from each other at predetermined interval. The optical film according to the present invention further comprises a plurality of micro lens patterns having arc-shaped optical sections formed below the optical patterns. The micro lens patterns have any one of a protruding shape and depressed shape.

Description

OPTICAL FILM AND DISPLAY DEVICE COMPRISING THE

SAME

Technical Field

[1] The present invention relates to an optical film and a display device comprising the same, and more particularly, to an optical film with an improved optical structure which can make up for drawbacks thereof and a display device comprising the optical film.

[2]

Background Art

[3] As shown in Fig 1, a display device 100 such as a liquid crystal display (LCD) for a

LCD monitor and a mobile phone or a LCD TV comprise an edge-light type lighting device. Also, a display device 100 for a LCD television set comprises a direct- type lighting device as shown in Fig. 2.

[4] The edge-light type lighting device and the direct-type lighting device comprise optical films 101 and 101' for condensing and refracting light emitted from light sources 102 and 102' and radiating the light to liquid crystal panels 105 and 105', respectively, so that images can be displayed on the liquid crystal panels 105 and 105'.

[5] The optical films 101 and 101' for condensing and refracting the light in the lighting devices 100 and 100 of the conventional display device have a plurality of optical patterns 103 and 103' having triangular sections and being arranged thereon in parallel, and so peaks 103 a and 103 a and valleys 103b and 103b are formed on the optical films 101 and 101 as shown in Figs. 1 and 2.

[6] However, in such conventional optical films 101 and 101 , since each of the optical patterns 103 and 103' has the triangular sectional shape in which peak region thereof is formed with an acute angle, there is a problem in that a defect such as a scratch may be generated partially and easily on the peak region of the optical patterns 103 and 103' due to carelessness of a worker or contact between the optical pattern and the other optical part during a processes of making, storing and managing the optical film, or coupling the optical film with other optical parts of a lighting device.

[7] Therefore, the optical film should be carefully handled in a manufacturing process, so there is a problem in that productivity and competitiveness are lowered due to deteriorated workability and a low yield.

[8]

Disclosure of Invention Technical Problem [9] Accordingly, an object of the present invention is to provide an optical film by which a yield as well as manufacturing convenience can be improved, a productivity and product competitiveness can also be improved, and the occurrence of an inferior product caused by a defect such as a scratch can be minimized.

[10] Another object of the present invention is to provide a display device comprising the above optical film.

[H]

Technical Solution

[12] To achieve the above object, an optical film of the present invention comprises micro-shaped optical patterns formed on at least one surface thereof. Each optical pattern has a peak and comprises defect-correcting structures formed thereon, and the defect-correcting structure is formed in areas within a height range of 30 or 40% from the peak based on the height of the optical pattern.

[13] The defect-correcting structures are one of the groups consisting of micro prominences, depressions, micro scratches, and burrs, and each of the optical patterns has any one sectional shape of a triangular shape, a polygonal shape and an arc shape. Also, the optical patterns are disposed in parallel and spaced from each other at predetermined interval.

[14] The optical film according to the present invention further comprises a plurality of micro lens patterns having arc-shaped optical sections formed below the optical patterns. The micro lens patterns have any one of a protruding shape and depressed shape.

[15] The optical film according to the present invention further comprises scattering structures provided on a surface of the optical film opposite to the surface on which the optical patterns are formed so as to induce optical scattering of incident light. The scattering structures are micro scratches or micro prominences and depressions formed by sand blasting or micro blasting process.

[16] In addition, the optical film according to the present invention further comprises diffusion structures formed by distributing diffusion particles in a region of the optical film so as to induce optical diffusion of incident light.

[17] The diffusion particles forming the diffusion structure may be any one of transparent solid particles selected from the groups consisting of acrylic particles, styrene particles, silicone particles, composite silica, glass beads and diamonds; white particles selected from the groups consisting of titanium oxide, zinc oxide, barium sulfate, calcium carbonate, magnesium carbonate, aluminum hydroxide and clay; and bubbles formed in the optical film.

[18] Advantageous Effects

[19] According to the optical film of the present invention mentioned above, a worker can more conveniently manufacture, store and manage the optical film of the present invention and also more conveniently couple the optical film with other optical parts for a lighting device and a display device. Also, a deterioration of the quality of the optical film can be prevented even though a defect such as a scratch is generated on the optical patterns. In addition, it is possible to improve luminance without using an additional scattering sheet.

[20] Thus, it is possible to improve productivity and competitive power of products according to an increased yield together with convenience of manufacturing and working, and to minimize a percentage defective of products.

[21] Although the preferred embodiments described above have been described with reference to the preferred embodiment thereof, it should be understood that numerous other modifications and embodiments can be devised by those skilled in the art that will fall within the spirit and scope of the principles of this disclosure. More particularly, various variations and modifications are possible in the component parts and/ or arrangements of the subject combination arrangement within the scope of the disclosure, the drawings and appended claims. In addition to variations and modifications in the component parts and/or arrangements, alternative uses will also be apparent to those skilled in the art.

[22]

Brief Description of the Drawings

[23] Figs. 1 and 2 are schematic structural views of display devices having conventional optical films;

[24] Figs. 3 to 7 are partial sectional views and partial perspective view of an optical film according to the first embodiment of the present invention;

[25] Figs. 8 to 11 are microscopic photographs showing optical pattern regions of an optical film according to the second embodiment of the present invention;

[26] Figs. 12 and 13 are microscopic photographs showing optical pattern regions of an optical film according to the third embodiment of the present invention;

[27] Fig. 14 is an enlarged microscopic photograph of a conventional optical film;

[28] Fig. 15 a view showing a luminance performance result according to viewing angles of the optical film shown in Fig. 14a;

[29] Figs. 16, 18 and 20 are enlarged microscopic photographs of the first, second and third optical films according to the present invention;

[30] Figs. 17, 19 and 21 are views showing luminance performance results according to viewing angles of the first, second and third optical films in Figs. 16, 18 and 20, re- spectively;

[31] Figs. 22 to 24 are views showing the optical films according to the present invention and luminance performance results according to viewing angles thereof;

[32] Figs. 25 and 26 are partial sectional views of an optical film according to the fourth embodiment of the present invention;

[33] Figs. 27 to 29 are partial sectional views of an optical film according to the fifth embodiment of the present invention;

[34] Fig. 30 is a partial sectional view of an optical film according to the sixth embodiment of the present invention; and

[35] Figs. 31 and 32 are exploded perspective showing schematically the structures of display devices having the optical films according to the present invention.

[36]

Best Mode for Carrying Out the Invention

[37] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[38]

[39] First embodiment

[40] Figs. 3 to 6 are partial sectional views and Fig. 7 is a partial perspective view of an optical film according to the first embodiment of the present invention.

[41] As shown in these figures, an optical film 10 of this embodiment includes optical patterns 11 for condensing and refracting incident light and radiating the light, and defect-correcting structures formed on the optical patterns 11 and correcting optical defects such as scratches that may be generated on the optical patterns 11.

[42] The linear shaped optical patterns 11 having triangular sections are arranged in parallel to define alternatively peaks 11a and valleys 1 Ib. The optical patterns 11 may be formed on at least one surface of the optical film 10 as shown in Figs. 3 to 7, or may be formed by molding light- transmissive resin on at least one surface of the optical film 10.

[43] Although not shown in the figures, the optical patterns 11 distributed on at least one surface of the optical film 10 may have various sectional shapes such as triangular pyramids, polygonal pyramids, corns or embossments and the like.

[44] The defect-correcting structures are formed as irregular features 12 that cause peripheral regions of the peaks 1 Ia of the optical patterns 11 to be blunt. As shown in Figs. 3 to 7, the irregular features 12 may be made by forming various kinds of prominences and depressions or recesses in the peripheral regions of the peaks 1 Ia of the optical patterns 11. The irregular features 12 may also be formed to have various shapes in addition to the aforementioned shapes so far as they cause the peripheral regions of the peaks 1 Ia to be blunt.

[45] At this time, the irregular feature 12 may be distributed over the peripheral region of the peak 1 Ia of each optical pattern 11, or a plurality of irregular features may be distributed in the peripheral region of the peak 1 Ia of each optical pattern 11 at regular or irregular intervals.

[46] In addition, each of the irregular features 12 is preferably formed on an area within a height range of 40% from the peak 11a, more preferably, within a height range of 30% from the peak 11a based on the height of the optical pattern 11.

[47] The distribution region of the irregular feature 12 and the ratio of the area on which the irregular feature 12 is formed to the height of the optical pattern 11 are requirements for maximizing the luminance property of the device comprising the optical film 10. The test results thereof will be described later.

[48] Since the optical film 10 according the first embodiment constructed as above is formed such that the peripheral regions of the peaks 1 Ia of the optical patterns 11 are not sharply formed, a defect such as a scratch and the like is not formed on the optical patterns 11 even though the optical film 10 comes into contact with other optical parts during the optical film manufacturing, storing and managing processes and a process for coupling the optical film with the other optical parts for constituting the lighting device.

[49]

[50] Second embodiment

[51] Figs. 8 to 11 are microscopic photographs showing optical pattern regions of an optical film according to the second embodiment of the present invention. As shown in the figures, the optical film 20 of this embodiment has substantially the same structure as that of the optical film 10 of the first embodiment explained above except defect- correcting structures. Thus, only defect-correcting structures of the optical film 20 according to the second embodiment will be described below.

[52] The defect-correcting structure of the optical film 20 according to the second embodiment is irregular micro- structured features 22 formed in a peripheral region of a peak 21a of each optical pattern 21. The irregular micro- structured features 22 are obtained by forming artificially various defects such as scratches or burrs in the peripheral region of the peak 21a of the optical patterns 21.

[53] These irregular micro- structured features 10' may be distributed over the peripheral region of the peak 21a of the optical pattern 21. Also, the irregular micro- structured features 10' may be distributed in the peripheral region of the peak 21a of the optical pattern 21 at regular or irregular intervals. At this time, although not shown in the figures, the optical pattern 21 may have various shapes having peaks, such as triangular pyramids, polygonal pyramids, corns or embossments, and [54] Moreover, the irregular micro- structured features 22 are preferably formed in an area within a height range of 30% from the peak 21a based on the height of the optical pattern 21.

[55] Like the first embodiment, the distribution region of the micro- structured features 22 and the ratio of the area on which the micro-structured features 22 are formed to the height of the optical pattern 21 are requirements for maximizing the luminance property of the device comprising the optical film 20. The test results thereof will be described later.

[56] The optical film 20 according to this embodiment having the above structure has the irregular micro- structured features 22 (that is, defects) artificially formed in advance in the peripheral regions of the peaks 21a of the optical patterns 21. Therefore, even though a defect such as a scratch is generated on the optical patterns 21 during the optical film manufacturing, storing and managing processes and a process for coupling the optical film 20 with the other optical parts for constituting the lighting device, the defect is included in the irregular micro-structured features 22 formed in advance, and so the defect is invisible to the user when the user observes the optical film 20 as a whole.

[57]

[58] Third embodiment

[59] Figs. 12 and 13 are microscopic photographs showing optical pattern regions of an optical film according to the third embodiment of the present invention. As shown in the figures, the optical film 30 of this embodiment has substantially the same structure as those of the optical films 10 and 20 of the aforementioned embodiments, except defect-correcting structures. Thus, the optical film 30 according to the third embodiment will be described below only in connection with the defect-correcting structure.

[60] The defect-correcting structure of the optical film 30 according to the third embodiment is formed as irregular micro-structured features 32 formed on surfaces of optical patterns 31. These irregular micro-structured features 32 are artificial defects such as micro prominences and depressions or micro scratches formed in the surfaces of the optical patterns 31 through a sand blasting process or a micro blasting process.

[61] The irregular micro-structured features 32 may be distributed over the entire surfaces of the optical patterns 31 or on a surface of each of the optical patterns 31 at regular or irregular intervals. The distribution region of the irregular micro-structured features 32 is a requirement for maximizing the luminance property of the device comprising the optical film 30. The test results thereof will be described later.

[62] The optical film 30 according to this embodiment having the above structure has the irregular micro- structured features 32 (that is, defects) artificially formed in advance in the entire surfaces of the optical patterns 31. Therefore, even though a defect such as a scratch is generated on the optical patterns 31 during the optical film manufacturing, storing and managing processes and a process for coupling the optical film 30 with the other optical parts for constituting the lighting device, the defect is included in the irregular micro- structured features 32 formed in advance, and so the defect is invisible to the user when the user observes the optical film 30 as a whole.

[63]

[64] Hereinafter, the luminance performance of the optical film according to the present invention will be compared with that of the conventional optical films 101 and 101' shown in Fig. 1 and Fig. 2. At this time, the optical film of the present invention used for the comparison is the optical film 10 having the defect-correcting structure 12 corresponding to the first embodiment.

[65] Fig. 14 is an enlarged microscopic photograph showing a conventional optical film, and Fig. 15 is a luminance performance result sheets of the optical film of Fig. 14 according to viewing angles.

[66] Figs. 16, 18 and 20 are enlarged microscopic photographs showing the first to third optical films according to the first embodiment of the present invention, respectively, and Figs. 17, 19 and 21 are luminance performance result sheets of the first to third optical films of Figs. 16, 18 and 20 according to viewing angles.

[67] Test results of the luminance performances of the conventional optical films 101 and

101' and the first to third optical films 10 according to the first embodiment of the present invention shown in the above figures are shown in Table 1 below.

[68]

[69] Table 1

[Table 1] [Table ] (Luminance unit: Nit)

[70] [71] As can be seen from Table 1 and the above figures, the maximum luminance of the optical films 10 according to the first embodiment of the present invention is deteriorated as a depth and a pitch of the defect-correcting structure 12 formed in the optical patterns 11 are increased.

[72] However, the above result indicates that, compared with the conventional films (101 and 101 in Fig. 1 and Fig. 2), the average luminance of the optical films according to the first embodiment of the present invention is increased. This means that the defect- correcting structures (irregular features) formed in the optical patterns of the optical films according to the first embodiment of the present invention cause scattering of light so that the luminance is increased at the time of observing the optical films as a whole.

[73] [74] Below, results of the test for illustrating a change of the luminance performance according to the sizes of the defect-correcting structures (the irregular features) of the optical films according to the present invention are illustrated. These test results are used to induce the requirement for maximizing the luminance property of the optical films according to a ratio of an area on which the defect-correcting structure (the irregular feature) is formed to the height of the optical pattern of the optical film described above.

[75] At this time, the optical film 10 according to the first embodiment of the present invention was used for the above tests.

[76] [77] Figs. 22 to 24 are views showing the optical films according to the first embodiment of the present invention and luminance performance results according to viewing angles thereof. Here, the optical film 10 shown in Fig. 22 is the optical film (A) having the defect-correcting structure 12 formed within a height range of 20% from the peak 11a based on the height of the optical pattern 11, the optical film 10 shown in Fig. 23 is the optical film (B) having the defect-correcting structure 12 formed within a height range of 30% from the peak 11a based on the height of the optical pattern 11 and the optical film 10 shown in Fig. 24 is the optical film (C) having the defect-correcting structure 12 formed within a height range of 20% from the peak 11a based on the height of the optical pattern 11. However, the optical films A, B and C shown in Fig. 22 to Fig. 24 has the same shape and the optical patterns have the same size.

[78] The luminance performance was tested for the optical films A, B and C and the luminance performance test results are shown in Table 2 below.

[79] [80] Table 2 [Table 2] [Table ] (Luminance unit: Nit)

[81] [82] As seen from Table 2 and the figures, as compared with the optical film on which defect-correcting structure is not formed, [83] The less the maximum luminance of the optical film is, the larger an area on which the defect-correcting structure is formed, however, the larger the average luminance of the optical film is, the larger an area on which the defect-correcting structure is, and the average luminance becomes reduced at a certain point of an area on which the defect-correcting structure is formed.

[84] From the above result, it is found that the optical film according to the present invention can exhibit the desirable luminance performance when the defect-correcting structure is formed within a height range between 20% and 40% from the peak based on the height of the optical pattern.

[85] In particular, it is possible to verify that the optical film of the present invention exhibits the most excellent luminance performance when the defect-correcting structure is formed within a height range between 20% and 30% from the peak based on the height of the optical pattern.

[86] As compared with the conventional optical film on which defect-correcting structure is not formed, as can be seen from the test results, the optical film of the present invention has the improved luminance performance and can improve the luminance of a display device without employing an additional scattering sheet when a lighting device is assembled.

[87] To enhance the optical performance, the aforementioned optical films according to the present invention comprising the optical patterns on which the defect-correcting structures as described above are formed can further comprises the optical structures as described below.

[88]

[89] Fourth embodiment

[90] Figs. 25 and 26 are partial sectional views of an optical film according to the fourth embodiment of the present invention.

[91] An optical film 40 according to the fourth embodiment comprises a base layer 40-1 and a pattern layer 40-2 formed on the base layer 40-1. A plurality of optical patterns 41 are formed on the pattern layer 40-2, and a defect-correcting structure 42 is formed at a peak region of each optical pattern 41.

[92] The base layer 40-1 has a plurality of micro lens patterns 43-1 (Fig. 25) or 43-2 (Fig.

26) and are spaced apart from each other at a certain intervals.

[93] As shown in Fig. 25, the micro lens pattern 43-1 may be a convex structure that protrudes upward. At this time, the optical patterns 41 corresponding to the micro lens patterns 43-1 are arranged along of the protruded convex surfaces of the micro lens patterns 43-1.

[94] On the other hand, the micro lens pattern 43-2 may be a concave structure as shown in Fig. 26, and the optical patterns 41 corresponding to the micro lens patterns 43-2 are arranged along of the depressed concave surfaces of the micro lens patterns 43-1.

[95] In addition, the micro lens patterns 43-1 and 43-2 may have the same diameter and height (or depth) or have the different diameter, interval and height (or depth). Also, the micro lens patterns 43-1 or 43-2 may be disposed regularly or irregularly. Furthermore, each of the micro lens patterns 43-1 or 43-2 may have a circular, oval or polygonal horizontal sectional shape, and the micro lens patterns 43-1 or 43-2 having a circular, oval and polygonal horizontal sectional shape may be disposed simultaneously on the same base member 40-1

[96] On the other hand, the base layer 40- 1 and the pattern layer 40-2 may be formed integrally with each other to form the optical film 40.

[97] The optical film 40 having such micro lens patterns 43-1 or 43-2 according to this embodiment corrects optical defects using the defect-correcting structures 42 described above and also scatters incident light on the micro lens patterns 43-1 or 43-2, thereby preventing a wet-out phenomenon that may be generated when the optical films 40 are optically coupled with adjacent optical parts.

[98] Moreover, the optical film 40 according to this embodiment has the advantage that the luminance becomes improved and viewing angles becomes wide. Due to the scattering of light simultaneously, the user does not observe scratches formed on the optical film 40 or foreign substances existed in the optical films 40.

[99]

[100] Fifth embodiment

[101] Figs. 27 to 29 are partial sectional views of optical film according to the fifth embodiment of the present invention. Like the optical films 10. 20 and 30 of the first to third embodiments, as shown in the figures, the optical film 50 of the fifth embodiment has defect-correcting structures 52 formed on optical patterns 51. In addition, the optical film 50 of the fifth embodiment further comprises scattering structures 53 formed on a surface of the optical film 50 opposite to a surface on which the optical patterns 51 are formed. The scattering structures 53 induce optical scattering of incident light,

[102] Here, as shown in Fig. 27, Fig. 28 and Fig. 29, the scattering structures 53 may be micro scratches 53-1 (Fig. 27) formed on an entire area or at least some area of opposite surface of the optical film 50 by means of a sand blasting process or a micro blasting process,. Alternatively, the scattering structures 53 may be micro recesses 53-2 (Fig. 28) or micro prominences 53-3 (Fig. 29) formed on the opposite surface of the optical film 50.

[103] At this time, the scattering structures 53-1, 53-2 or 53-3 may be formed at regular or irregular intervals, and micro scratches, micro recesses and micro prominences are simultaneously formed on the same optical film 50 as the scattering structures 53-1, 53-2 or 53-3.

[104] It will be apparent that the scattering structures 53-1, 53-2 or 53-3 may be formed in various configurations in addition to the aforementioned configurations so far as they can scatter incident light.

[105] Furthermore, the scattering structures 53-1, 53-2 or 53-3 in the fifth embodiment can also be applied to the optical films 10, 20 and 30 according to the first to third embodiments as well as the optical film 40 according to the fourth embodiment.

[106] In the optical film 50 having the scattering structures 53-1, 53-2 or 53-3 according to the fifth embodiment, incident light is scattered by the scattering structures 53-1, 53-2 or 53-3 and then condensed and refracted by the optical patterns 51, so that high luminance can be exhibited and scratches formed on the optical film 50 or foreign substances existed in the optical film 50 cannot be observed by the naked eye due to the scattering of the light. In addition, the defect-correcting structures 52 can correct optical defects as described above.

[107]

[108] Sixth embodiment

[109] Fig. 30 is a partial sectional view of an optical film according to the sixth embodiment of the present invention. Like the optical films 10, 20 and 30 according to the first to third embodiments, as shown in the figure, the optical film 60 of the sixth embodiment has optical patterns 61 on which defect-correcting structures 62 are formed. The optical film 60 of the sixth embodiment further comprises a diffusion structure3 63 for inducing optical diffusion of incident light.

[110] The diffusion structure 63 may be provided by distributing diffusion particles on at least a partial area of the optical film 60. At this time, the diffusion particles are transparent solid particles that may be any one of acrylic particles, styrene particles, silicone particles, composite silica, glass beads, and diamonds.

[I l l] Further, the diffusion may be formed of any one of titanium oxide, zinc oxide, barium sulfate, calcium carbonate, magnesium carbonate, aluminum hydroxide, and clay as white particles that. In addition, a plurality of bubbles formed in the optical film 60 may act as the diffusion structures 63.

[112] The diffusion structures 63 may be distributed in the optical film 60 by molding raw material containing the diffusion particles into the optical film. Alternatively, although not shown in the figure, the diffusion structures may be provided as an additional diffusion layer on a back surface of the optical film 60.

[113] Here, it will be apparent that the diffusion structures 63 formed in the optical film 60 of the sixth embodiment may be applied to the optical films 40 and 50 of the fourth and fifth embodiments as well as the optical films 10, 20 and 30 of the first to third embodiments. [114] In the optical film 60 having such diffusion structures 63 according to the sixth embodiment, incident light is diffused by the diffusion structures 63 and then condensed and refracted by the optical patterns 61, and so light of high luminance can be radiated within in a wide viewing angle range and optical defects can be corrected using the aforementioned defect-correcting structures 62.

[115] Further, even though a defect, for example, scratch, stain, or foreign substance such as dust is generated in the optical film 60 due to carelessness of the worker during the manufacturing process, the defect is invisible to the naked eye due to diffusion of light. Thus, it is possible to improve productivity and lower a percent defective of products.

[116] Figs. 31 and 32 are exploded perspective showing schematically the structures of display devices having the optical films according to the present invention, Fig. 31 shows the display device 200 comprising an edge-light type lighting device and Fig. 32 shows the display device 300 comprising a direct type lighting device.

[117] In the display device 200 as shown in Fig. 28, the optical film (for example, 10) of the present invention is mounted between a light source 210 and a panel 220 to condense, refract and scatter light emitted from the light source 210 and to subsequently radiate the light toward the panel 220.

[118] Like the above display device 200, in the display device 300 as shown in Fig. 29, the optical film (for example, 10) of the present invention is mounted between a light source 310 and a panel 320 to condense, refract and scatter light emitted from the light source 310 and to subsequently radiate the light toward the panel 320

[119] In the above display devices 200 and 300, when the optical film is coupled with other optical parts, a defect such as a scratch may be formed on the optical patterns of the optical film due to contact between the optical pattern and the adjacent parts or carelessness of a worker. However, since the optical film of the present invention includes the defect-correcting structures formed on the optical pattern in advance as mentioned above, a defect such as a scratch can be optically made up for by the defect- correcting structures.

[120] In addition, the distribution ratio and configuration of the defect-correcting structures and the like improve the luminance performance of the optical film without employing an additional scattering sheet. Accordingly, it is possible to simplify a manufacturing process and save the production costs of the display devices 200 and 300.

[121]

Industrial Applicability

[122] The optical film according to the present invention is applicable to an edge-light type and direct-type lighting device for a display device.

Claims

[1] An optical film, comprising: micro-shaped optical patterns formed on at least one surface thereof, wherein each optical pattern has a peak and comprises defect-correcting structures formed thereon, the defect-correcting structures are formed in areas within a height range of 40% from the peak based on the height of the optical pattern.

[2] The optical film as claimed in claim 1, wherein the defect-correcting structures are formed in areas within a height range of 30% from the peak based on the height of the optical pattern.

[3] The optical film as claimed in claim 1, wherein the defect-correcting structures are one of the groups consisting of micro prominences, depressions, micro scratches, and burrs.

[4] The optical film as claimed in claim 1, wherein each of the optical patterns has any one sectional shape of a triangular shape, a polygonal shape and an arc shape.

[5] The optical film as claimed in claim 4, wherein the optical patterns are disposed in parallel and spaced from each other at predetermined interval.

[6] The optical film as claimed in claim 1, wherein each of the optical patterns has any one shape of a triangular pyramid, a polygonal pyramid, a corn and an embossment, and the optical patterns are distributed at predetermined intervals.

[7] The optical film as claimed in claim 1, further comprising a plurality of micro lens patterns having arc-shaped optical sections formed below the optical patterns.

[8] The optical film as claimed in claim 7, wherein each of the micro lens pattern has any one of a protruding shape and depressed shape.

[9] The optical film as claimed in claim 1, further comprising scattering structures provided on a surface of the optical film opposite to the surface on which the optical patterns are formed so as to induce optical scattering of incident light, wherein the scattering structures are micro scratches or micro prominences and depressions formed by sand blasting or micro blasting process.

[10] The optical film as claimed in claim 1, further comprising diffusion structures formed by distributing diffusion particles in a region of the optical film so as to induce optical diffusion of incident light, wherein the diffusion particles are any one of transparent solid particles selected from the groups consisting of acrylic particles, styrene particles, silicone particles, composite silica, glass beads and diamonds; white particles selected from the groups consisting of titanium oxide, zinc oxide, barium sulfate, calcium carbonate, magnesium carbonate, aluminum hydroxide and clay; and bubbles formed in the optical film. [11] A display device, comprising: a light source; a panel provided above the light source; and an optical film according to any one of claims 1 to 10, the optical film being disposed between the light source and the panel to cause light emitted from the light source to be condensed and refracted toward the panel.