TWI485448B - Light guide film - Google Patents

Description

Light guiding film

The present invention relates to a light guide, and more particularly to a light guide for use in a flat panel display, and more particularly to a light guide for use in a liquid crystal display panel.

Compared to the electroluminescent material layer in the plasma display panel, in a liquid crystal display (LCD) panel, a liquid crystal (LC) layer does not emit light intrinsically. The liquid crystal layer or panel functions as a modulator of light that penetrates the liquid crystal layer. In a backlit LCD panel, the backlight module acts as a planar light source that is an important component of the LCD panel and is important to enhance the brightness of the LCD panel. The backlight module includes a light guiding plate for guiding a light source from a planar array (for example, a planar array LED) or a line source (for example, a Cold Cathode Fluorescence (CCFL) tube. Or a column of LED light. The backlight module having the latter line light source is referred to as an edge-lit backlight module in the present technology.

So far, the conventional light guiding plate incorporated in the edge-lit backlight module uses Total Internal Reflection (TIR) to guide the light emitted by a light source located at the edge surface of the light guiding plate to face. The light-emitting main plane surface of the liquid crystal panel. Light emitted from the light source is guided to propagate to the reverse edge surface of the light guiding plate via the light guiding plate so that light can be emitted from the entire planar surface toward the liquid crystal panel. In the past, another main plane table in the light guiding plate opposite to the surface of the light emitting plane The structure of the face (for example, the bottom surface) helps to reflect light toward the top planar surface. For example, in some prior art light guides, a reflective layer may be provided at the bottom surface to reflect light back into the light guide. In other prior art light guiding plates, the configuration of the bottom surface of the light guiding plate opposite the light exiting surface may have a plurality of reflective or astigmatic surface dots. The light beam encountering the dots will scatter and/or reflect toward the light emitting surface of the light guide. More specifically, the light reflecting or light scattering dots formed or embedded in the bottom surface of the conventional light guiding plate can change the direction of propagation of the light beam to disperse light from the line source in the plane. In the illuminating surface, a planar light source for emitting light from a plane is formed. Due to process characteristics, the diffused and reflective surfaces of such reflective or astigmatic dots are typically matte. Accordingly, the point or line source requires a significant amount of energy to produce a planar light output of acceptable brightness, thereby wasting electrical power consumption.

Another technique for utilizing a V-cut light guide plate has been developed in the field of backlight modules. The V-shaped grooving light guiding plate is mainly made by directly micro-manufacturing a plurality of prisms on a light guiding plate, and is usually combined with a reverse gusset in a backlight module. As shown in FIG. 1, the prior art backlight module mainly comprises: a reverse diaphragm 3; a V-shaped slotted light guide plate 2 having a tapered thickness; and a reflective film 1 under the reverse diaphragm And a diffusion film 4 located above the reverse plate. The liquid crystal panel (not shown) is placed on the top end of the diffusion film 4. A line source/reflector 5 will be positioned at the thicker edge of the light guide plate 2. Brightness of a backlight module using a V-shaped slotted light guide plate compared to earlier conventional backlight modules (brightness) can be enhanced by nearly 30%. Therefore, the improved backlight module can save about one-third of the total power consumption in a particular output brightness, which is a significant improvement in energy saving performance.

The light guide plates used in backlight modules are typically made by injection molding. In general, the molten polymethyl methacrylate (PMMA) material is filled into a cavity which has the desired mold structure and maintains the holding pressure. The material can then be cooled and hardened to conform to the configuration of the cavity. However, when it relates to a V-grooved light guide plate, there is a high defect rate due to the difficulty in manufacturing the cavity and the above-described injection molding process characteristics. Copying a master mold having a V-grooved structure made by CNC precision machining often has manufacturing variations and/or defects. Therefore, the manufacture of the V-grooved light guide plate becomes more difficult and thus more expensive.

Furthermore, the problems of prior art light guide plates have been exacerbated by the stricter requirements of the lighter weight, thinner profile, and more flexible structures of LCD devices that have gradually become mainstream in recent years. Due to the limitations of injection molding, it is not easy to make a thin and flexible light guide plate by this method. Specifically, when it comes to large LCD panel sizes, the defect rate will be higher.

There is still a need in the art for a backlight having a thin and flexible structure with an effective planar light output and ease of fabrication.

The present invention provides a thin light guiding film having a structure which is relatively easy to manufacture with high yield. In one aspect of the invention, the light directing film is flexible. More specifically, the present invention provides a flexible light directing film having a light-adjusting structure in the form of a bottom side of the light directing film (ie, facing away One side of the liquid crystal panel has a cylindrical lens-like microstructure.

In one embodiment, the light directing film includes a substrate layer for supporting a layer of light adjustment structure. In another embodiment, the light adjustment structure comprises an array of a plurality of longitudinal lenticular lenses arranged in parallel in a lateral direction. The light directing film may further comprise a type of germanium microstructure located on the light emitting side of the light guiding film (i.e., the side facing the liquid crystal panel). The light directing film can be fabricated by coating/imprinting a roll of sheet material (single or double sided depending on whether both sides of the light directing film are to be constructed) in a roll-to-roll continuous process. The sheet material may be bright, clear or transparent, may have microparticle coating, and/or be built into the luminescent surface. According to the present invention, the thickness of the light guide is greatly reduced. In addition, the roll-to-roll process can more accurately replicate the microstructure on the master mold master or the roller on the surface of the light directing film, thereby reducing the defect rate and manufacturing cost.

This description is the best mode for carrying out the invention. The invention will be described herein with reference to various embodiments and drawings. The purpose of the description is to explain the general principles of the invention and should not be construed as limiting. It will be apparent to those skilled in the art that changes and modifications may be made in accordance with the teachings without departing from the scope and spirit of the invention. The scope of the invention is primarily dependent on the scope of the accompanying claims.

2 is a schematic structural view of a backlight LCD device incorporating a light guiding plate according to an embodiment of the present invention. According to an embodiment of the invention, the backlight LCD 10 includes a liquid crystal display module 12, a planar light source in the form of a backlight module 14, and a liquid crystal module 12 and the backlight module. Several optical films between groups 14. The liquid crystal module 12 includes: a plurality of liquid crystals sandwiched between two transparent substrates; and control circuitry for defining a two-dimensional pixel array. The backlight module 14 provides a planar light spread of a side light type, wherein a line of light sources 16 (for example, a column of independent LEDs or a longitudinal cold cathode fluorescent tube) is provided in a light guide according to the present invention. At the edge of the membrane 18. A reflector 17 is provided to direct light from the line source 16 into the light directing film 18 via the edge of the light directing film 18. The liquid crystal module 12 modulates the incident backlight via the module according to the image data. The present invention is described with a liquid crystal module as a light modulator; however, the light directing film of the present invention is equally applicable to other types of modulation devices used to modulate an incident backlight.

In particular, the present invention relates to a novel structure of a thin and flexible light directing film having a light adjustment structure for varying the light path. In one embodiment, a first optical layer composed of a flexible transparent material supports a second optical layer formed on a lower side of the first optical layer and having a light adjustment structure. Wherein the first and second optical layers have the same or different refractive indices. According to the embodiment of the invention illustrated in Figure 2, the thin and flexible light directing film 18 has a clear or transparent flexible substrate layer 19 that supports a clear or transparent light modulating structure 20, The light adjustment structure typically includes an array of a plurality of columns of laterally aligned lenticular lenses 21. The light guiding film 18 is constructed such that the light adjusting structure 20 is defined at a bottom main surface of the liquid crystal module 12 for spreading and directing light through the flat and smooth surface facing the liquid crystal module 12. Top main plane surface. A reflective sheet 22 can be provided to aid in capturing light through the film Any light that escapes from the lower side of 18 is redirected to the light directing film 18.

In the illustrated embodiment, there are two micro-base substrates 26 and 28 that are constructed that are arranged such that the longitudinal 稜鏡 structures are generally orthogonal or slightly smaller than the orthogonal between the two substrates. angle. The micro-deposited substrates 26 and 28 are constructed to enhance the luminosity or brightness and redirect the light closer to the vertical viewing axis. A diffusion plate 27 is provided between the light guiding film 18 and the lower micro-base substrate 28. Alternatively, and additionally, one or both of the micro-deposits 26 and 28 may incorporate a diffusing structure at a respective bottom surface facing the light directing film 18 to provide both light collimation and light diffusing functionality, It does not require a separate diffuser plate(s), which further reduces the overall thickness of the LCD 10. </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt;

The light entering the liquid crystal module 12 via the optical film shown in FIG. 2 is very uniform in the space of the planar region of the liquid crystal module 12 and has a very strong vertical light intensity.

In accordance with the present invention, the novel optical substrate can be used in a display device having a planar or curved and rigid or flexible display panel that includes an array of display pixels. The planar light source is directed to provide illumination to cover a source of light in an area of the array of display pixels. Accordingly, for a display panel having a curved image plane composed of a plurality of display pixels (the panels may be rigid or flexible), the backlight covers the display pixel array in the curved plane to serve the curved image The plane effectively provides illumination coverage.

The structure of the surface of the columnar structure will be described in more detail below. For easy reference See, the following orthogonal x, y, z coordinate systems will be used when interpreting the various directions. For the embodiment shown in Figure 2, the x-axis is in the direction across the lenticular lenses 21, which is also referred to as the lateral or traversing direction of the lenticular lenses 21. The y-axis is orthogonal to the x-axis, typically in the plane of the light directing film 18, in the longitudinal axis or direction of the lenticular lenses 21. The longitudinal direction of a lenticular lens 21 is from one end of the lenticular lens 21 to the other end. The lenticular lenses 21 typically fall in the x-y plane. For a rectangular light directing film 18 workpiece, the x and y axes are along the orthogonal sides of the light directing film 18. The z-axis is then orthogonal to the x and y axes. The edge of the end of the laterally aligned column of the lenticular lens 21 appears in the x-z plane, as shown in Fig. 2, which also represents a sectional view in the x-z plane. The cross-section of the lenticular lenses 21 is a cross-section taken in the x-z plane along each position of the y-axis. In addition, the horizontal direction refers to the x-y plane, and the vertical direction refers to the z direction.

In the embodiment shown in the figures, the cylindrical structure surface comprises a shallow curved lens structure (for example, a convex or concave lens structure, or a combination of convex and concave). In the embodiment shown in Figure 2, the cylindrical structure surface comprises a plurality of columns of parallel convex cylindrical lenses 21, each extending continuously between the two opposite edges of the light directing film 18 at y In the direction. In another embodiment not shown, the lenticular lenses may be concave lenses. In the embodiment shown in this figure, the curved surfaces of adjacent lenticular lenses 21 are spaced apart (i.e., not intersected) such that a plurality of parallel spaces or grooves defining a longitudinally flat bottom between the lenticular lenses 21 are defined. Slot 24. In other embodiments not shown, the curved surfaces of adjacent lenticular lenses may intersect. For the lenticular lens 21, the x-axis is in a direction spanning the valleys 24 and the lens 21, which is also referred to as the columnar junction The lateral or crossing direction of the surface. The y-axis represents the longitudinal axis or direction of the lenticular lenses 21 and grooves 24. The longitudinal direction of the lenticular lens 21 means a direction in which the convex lens section is from the one end of the lenticular lens 21 to the other end. The edge of the laterally aligned column of the lenticular lens 21 shown in Fig. 2 falls in the x-y plane, which also represents a cross-sectional view in the x-z plane.

7 is a cross-sectional view of the x-z plane for explaining the general structural parameters of a light guiding film. Referring to FIG. 7, the light directing film 500 includes: a substrate layer 510; and a plurality of lenticular lenses 520 having a plurality of convex curved surfaces 524 formed on a bottom surface of the substrate layer 510. The surface 524 of each of the lenticular lenses 520 substantially corresponds to a surface section of a cylinder 522 having a center of the section "O" and a radius of "r", the surface section corresponding to an arc angle θ and a section The arc between "a" and "b" at the midpoint. In the cross-sectional view shown in Fig. 7, the lens 520 corresponds to a portion of the circle 522 surrounded by the chord a-b and the arc a-b. As shown in Figure 7, adjacent arcuate surfaces 524 of lenticular lens 520 are not in contact with one another to form a continuous or continuous lens surface (as discussed further below, in the embodiment shown in Figures 6A and 6B, in part The arcuate surfaces of the lenticular lenses may intersect each other). The bottom of the surface 524 of each lens 520 is at the top end of the substrate layer 510 with a flat spacing between adjacent lenses 520. In the embodiment shown in the figures, the discontinuous lenses 520 have the same lens width d1. The spacing d2 in a particular area will remain constant, but will be different in different areas.

In a preferred embodiment, the angle θ of the columnar structure is in the range of 5 to 90 degrees, more preferably in the range of 10 to 45 degrees. a height d3 of the lenticular lens structure (measured from the top end of the substrate layer 510, or If the substrate layer and the lenticular lens structure are integrally formed, they are completely equalized from the valleys between adjacent non-intersecting or non-overlapping lenticular lenses (or other embodiments not shown). It may be different), preferably in the range of 0.5 μm to 100 μm, preferably in the range of 1 μm to 60 μm, more preferably in the range of 1 μm to 45 μm. The curvature of the lenticular lenses is the same. The distance between the centers O of adjacent lenses (i.e., d1 + d2) = 5 μm to 1000 μm.

In the embodiment shown in Figure 2, the lenticular lenses 21 each have the same cross-sectional profile in the y-z plane. The cross section of the lenticular lens 21 is a section taken in the y-z plane along each position of the x-axis. In addition, the horizontal direction is in the x-y plane, and the vertical direction is in the z direction. In this embodiment, the curvature and height of the lenticular lens 21 are the same in all the lenticular lenses, respectively, and the distance between the two discontinuous lenticular lenses 21 of the constructed cylindrical surface is the same. In this embodiment, the surface bottom of each of the lenses 21 is at the top end of the substrate layer 19. 2 shows a plurality of isolated or independent lenticular lenses 21 attached to the substrate layer 19; however, it should be understood that the lenticular lens 21 layer may also contain separate but lateral interconnects (for example, by the same material) A thin web made; for example, see the lenticular lens 21 of Figure 4). The overall structure of the lenticular lens 21 layer is similar to a layer of lenticular lenses 21 supported on a thin substrate layer of the desired height in order to maintain adhesion to the integrity of the substrate layer 19.

In this embodiment, the cross-sectional profile of the lenticular lens 21 conforms to a portion of a circle (that is, the lenticular lens 21 conforms to the surface of a portion of a cylinder). Adopted to have a circle other than (for example, ellipse or moment The cylindrical surface of the cylinder of different cross-sections of other cross-sections of irregular or irregular geometry also falls within the scope of the present invention.

In the embodiment shown in FIG. 2, the light directing film 18 includes two separate layers comprising a flexible substrate layer 19 and a light conditioning structure 20 layer. The structural layer 20 is adhered to the substrate layer 19 to form the entire light directing film 18. It will be appreciated that the light directing film 18 may also be constructed of a single integrated solid material layer rather than two separate physical layers without departing from the scope and spirit of the invention. The light directing film 18 may be a unitary or unitary body that includes a base portion that carries the surface structure of the cylindrical lenses 21.

The columnar structure provides an improved light directing effect for directing light to the top light output surface of the light directing film 18 to enhance the luminosity of the liquid crystal module 12. When light emitted from a light source 16 is projected into the substrate layer 19, the light enters the lenticular lens layer 21 from the substrate layer 19 following the light path L shown in FIG. 2, and the first occurrence occurs. Secondary refraction. When the light passes through the layer of the lenticular lens 21, the lenticular lenses 21 change the optical path. Then, light passes through the substrate layer 19 toward the upper surface of the substrate layer 19 (which is also the upper surface of the light guiding film 18). Finally, light is emitted through the upper surface of the light guiding film 18. In general, a uniform planar surface source will be defined by the light directing film 18.

It can be understood that in the thin and flexible light guiding film 18 of the present invention, the difference in refractive index between the substrate layer 19 and the layer of the lenticular lens 21 is controlled and the light adjustment by the lenticular lens layer 21 is controlled. The refractive index and complete reflection caused by the structure can control the light advancement path L. The present invention simplifies the light tone compared to the conventional V-shaped slotted light guide plate described in the prior art paragraph above The design of the entire structural surface is because the lenticular lenses have low requirements for precision processing techniques and thus can improve the yield of the light directing film 18.

The light-adjusting structure of the light directing film 18 may be in the form of a regular or irregular columnar structure. The improvement effect of the light-adjusting structure of the light-guiding film 18 can be better explained with reference to FIG. 3 than the 稜鏡 structure of the conventional light guiding plate 2 (FIG. 1). As shown in Fig. 3, the upper inverted triangle represents the conventional structure of the light guiding plate 2 shown in Fig. 1. The lower lens represents the cross-sectional profile of the lenticular lens 21 of the light guiding film 18. The dashed segments T _P and T _L represent the slopes of the various surface portions of the surface below the individual profile profiles. As can be seen from Figure 3, the structure of the slope because the Prism 2 T _P is constant, it is difficult to design and manufacture the interrupt total internal reflection (TIR, total internal reflection) and then the horizontal light guide. Conversely, for the lenticular lens 21, the slope T _{L of the} tangent is different at each position of the convex lens surface of the lens 21. This breaks the horizontal plane of the TIR making design and manufacturing easy. By considering the effect of the tangential change on the interrupted TIR, the degree of design freedom is greatly increased, and the tangential change can be adjusted by changing the shape and/or size of the lenticular lenses. For example, the interrupted horizontal plane of total internal reflection can be adjusted by (a) the distance between two adjacent lenses 21; and/or (b) the radius of curvature of the lens 21. The columnar structure is used as the light adjustment structure of the present invention to achieve a more flexible design.

In the embodiment shown in the figures, the lenticular lens 21 layer and the substrate layer 19 can be made of the same or different materials. The lenticular lens layer 21 and the substrate layer 19 may be formed using a light transmissive material, preferably a polymerizable resin such as a resin curable by ultraviolet light or visible light radiation, for example, a UV curable adhesive. The light directing film 18 can be coated by a roll-to-roll continuous process / Imprinting a roll of sheet material (single or double sided, depending on whether or not the sides of the light directing film are to be constructed). Generally, the structural columnar surface is formed by coating a coatable composition comprising a polymerizable and crosslinkable resin onto a master or master roll and performing a hardening process. . The columnar structures can be formed on a separate base film layer by die assembly, roller press, die stamping assembly, or other equivalent means. The base film of the lenticular lens 21 layer 20 is bonded to the flexible substrate layer 19 (by directly stacking or applying an adhesive (for example, Pressure Sensitive Adhesive (PSA)) to the layers). The structure of the light guiding film 18. Obviously, a combination of many techniques and manufacturing methods can be applied to achieve the purpose of combining the structural columnar surface and the substrate layer, or equivalent purposes thereof. It is also possible to design the thin light guiding film 18 first and then combine another significantly thicker substrate (for example, using the assembly process described above) to achieve a thicker light guiding plate that does not detach The scope and spirit of the invention.

As mentioned above, most of the conventional V-grooved light guiding plates are formed by injection molding, and therefore, the refractive index of the crucible structure on the lower side facing away from the liquid crystal module and the base substrate are The refractive indices are the same, and the enthalpy should be further designed (for example, angle, width, or depth) to control the direction of refraction of the light in order to achieve the effect of directing the direction of the light path. On the contrary, for the thin and flexible light guiding film of the present invention, the light adjusting structure 20 is formed on the substrate layer 19 by a coating method, so that the layers have different refractive indexes. Therefore, the light path can be controlled to achieve the effect of directing the direction of the light toward the light-emitting surface of the light-guide film toward the light-emitting surface of the liquid crystal module 12. According to an embodiment of the invention, the two layers The absolute value of the refractive index difference ranges from 0.001 to 0.6.

In another embodiment, the substrate layer 19 and the lenticular lens layer 21 can be integrally formed on a thick transparent mold substrate by casting, stamping, stamping, wheel pressing, or extrusion. For a further discussion of a process for forming a substrate having a plurality of structural surfaces, reference is made to U.S. Patent No. 7,618,164 which is incorporated herein by reference.

The flexible transparent material suitable for the substrate layer 19 of the thin and flexible light directing film 18 can be made of various types of materials known to those skilled in the art, for example, plastic, for example, which may include, but Not limited to: polyester resins, for example, polyethylene terephthalate (PET) and polyethylene naphthalate (PEN); polyacrylic resins, for example, polymethyl methacrylate (PMMA); Polyimide resin; polyolefin resin, for example, polyethylene (PE) and polypropylene (PP); polycyclic olefin resin; polycarbonate resin; polyurethane resin; polyethylene resin, for example, polyvinyl alcohol (PVA) or Polyvinyl chloride (PVC); triacetate (TAC); or a mixture thereof. In one embodiment, the preferred substrate is polymethyl methacrylate (PMMA). Likewise, the lenticular lens 21 layer can be made of a material that is identical to the substrate layer 19, such as an acrylic resin or any other transparent material known to those skilled in the art to be adhered to the substrate layer 19.

The thickness of the substrate layer 19 is constant (that is, the reverse surface of the substrate layer 19 is parallel), and the range may be from 100 μm to 800 μm, more preferably from 125 μm to 600 μm. In another embodiment not shown, the substrate layer 19 may be tapered, for example, the thickness may be thinned from the edge of the light input to the reverse edge. The thickness of the lenticular lens layer 21 of the light guiding film 18 (or the The height of the lenticular lens 21 may be between 0.5 μm and 100 μm, preferably between 1 μm and 60 μm, and more preferably between 1 μm and 45 μm.

In the embodiment shown in FIG. 2 (also referring to FIG. 7), the vertical height d3 of the lenticular lenses 21 (the crown height of the lens measured from the top end of the substrate layer 19, or in the case of the substrate layer 19) When integrally formed with the lenticular lenses 21, they are equally equalized from the valleys between the adjacent lenticular lenses 21 which are not intersected, preferably in the range of 0.5 μm to 100 μm, preferably 1 μm to In the range of 60 μm, more preferably in the range of 1 μm to 45 μm. The curvature of the lenticular lenses is the same. The interval d1 (between the edges of adjacent lenticular lenses) is the same = 0 μm to 1000 μm; the width d2 of all the lenticular lenses (the distance between the side edges of the convex surfaces) is the same =0 μm to 1000 μm. The center interval between adjacent lenticular lenses (i.e., d1 + d2) = 3 μm to 1200 μm. If a thin base film (mesh) and the cylindrical lens 21 in layer 20 are integrally formed to help maintain adhesion integrity (see base film 42 in Figure 4), the thickness (or bottom thickness) of the film may range Between 5 and 800 microns.

The concept of the present invention extends a light-adjusting structure comprising a lenticular lens coated with particles and/or particles embedded in a cylindrical surface.

4 and 5 are other embodiments of the light directing film of the present invention which combine a ruthenium structure and a columnar structure on both sides of a substrate.

In the embodiment of FIG. 4, the structure of the light directing film 48 combines the tantalum structure and the columnar structure on the reverse side of the substrate layer 49. In particular, the light directing film 48 has a structural cylindrical surface 40 and a structural tantalum surface 44. The structure of the lenticular lens 41 is the same as that of the lenticular lens 21 of the previous embodiment, The lenticular lens 41 layer 40 includes a thin base film 42 integrally formed with the convex lenses. The interval d1, the width d2, and the crown height d3 of the lenticular lenses 41 may remain constant, or two of the parameters (d1, d2, d3) in the light guiding film may remain constant to change one of the parameters, or One of the parameters in the light directing film remains constant while changing the other two parameters.

In the embodiment shown in this figure, the structural haptic surface 44 is a light output surface that enhances brightness (i.e., improves light collimation) along an orthogonal viewing axis, and the structural columnar shape Surface 40 is as the light-adjusting surface of light guiding film 48 for internal reflection as in the previous embodiment. As shown in FIG. 4, the crucible surface 44 includes a plurality of rows of parallel continuous or continuous longitudinal prisms 45 extending between the two opposite edges of the substrate layer 49. The longitudinal prisms 45 are arranged in a laterally parallel arrangement (side by side) to define a plurality of parallel peaks 46 and valleys 47. The cross-sectional profile of peak 46 is symmetric to the vertical line (as seen in the y-z plane). The peak apex angles may be right angles, and in the plane of the equal surface 44, the peaks have a constant or similar height and/or the valleys have a constant or similar depth. The distance or spacing between adjacent peaks/valleys shown in the embodiment of Figure 4 is constant. In the embodiment shown in the figures, the structural meandering surface 44 and the structural cylindrical surface 40 are substantially parallel to each other throughout the light directing film structure (i.e., do not form light such as in a backlight module) The guide plate is substantially a tapered overall substrate structure). In another embodiment, the height or the prisms may differ in the longitudinal and/or lateral directions in the plane of the light directing film. The laterally adjacent prisms may be separated (i.e., there is a gap between adjacent prisms). In FIG. 4, the longitudinal direction of the lenticular lenses 41 The axes (in the y-direction) are orthogonal to the longitudinal axis of the prisms 45 (in the x-direction).

The double-sided light directing film 48 of Figure 4 can be fabricated in the same manner as described above for the same process as described above. The light directing film 48 can be fabricated by coating/imprinting the sides of a roll of sheet material in a roll-to-roll continuous process. Either or both of the columnar structure surface 40 and the crucible surface 44 may be formed as a separate layer of the substrate layer 49 or integrally formed with the substrate layer 49. In the embodiment illustrated in FIG. 4, the light directing film 48 includes three separate layers comprising: the tantalum surface 44, the flexible substrate layer 49, and the structural cylindrical surface 40 layer. The tantalum surface layer 44 and the structural pillar layer 40 are adhered to the substrate layer 49 to form the entire light directing film 48. It will be appreciated that the light directing film 48 may be constructed of a single integrated solid material layer rather than three separate physical layers without departing from the scope and spirit of the invention. The light directing film 48 may be a unitary or unitary body that includes a base portion that carries the prisms 45 and the surface structures of the cylindrical lenses 41.

In the embodiment of FIG. 5, like the embodiment of FIG. 4, the structure of the light directing film 58 combines the 稜鏡 structure and the columnar structure on the reverse side of the substrate layer 59. In particular, the light directing film 58 has a structural cylindrical surface 50 and a structural tantalum surface 54. In this embodiment, the lenticular lens 51 layer 50 includes a thin base film 52 integrally formed with the convex lenses 51. The structure of the lenticular lenses is the same as in the earlier embodiment; however, the interval d2 between the edges of the two discontinuous adjacent lenticular lenses 51 in the structural columnar layer 50 may change in the x-direction section. Or not the same. The width d2 of the lenticular lenses is the same and constant. The heights of the lenticular lenses 51 (measured from the top end of the base film 52) are completely equal.

The crucible surface 54 comprises a plurality of columns of parallel continuous or continuous longitudinal prisms 55 that are identical to the structure of the crucible surface 45. The double-sided light directing film 58 of Figure 5 can be fabricated in the same manner as described above for the same process as described above. In FIG. 5, the longitudinal axes of the lenticular lenses 51 (in the y direction) are orthogonal to the longitudinal axes of the prisms 55 (in the x direction).

In other embodiments not shown, there is no tantalum surface (44, 54 in the previous examples), or in addition to the tantalum surface, the light-emitting surface of the light directing film may also be coated with particles and/or The substrate layer or the surface of the crucible (if provided) has built-in particles.

In other embodiments not shown, the vertical heights of the structures of the lenticular lenses may vary. Further, the radii of curvature of different lenticular lenses may also be different and/or different cylindrical surfaces may conform to those having a circular shape (for example, an elliptical or other profile of a rectangular or irregular geometry). Columns of different profiles and will have different sizes. The present invention also contemplates longitudinal columnar structures having a uniform profile to define one of the different convexly curved surface profiles (for example, different lenticular lenses have the same or different profiles).

Experimental structure:

Experiments have been made herein to determine the effect of the dimensional change of the lenticular lenses on the uniformity of the light intensity distribution of the light directing film of the present invention.

Referring to the further embodiment of Figures 6A and 6B, the light directing film 180 discussed herein has a diagonal dimension of about 10.1 inches and is constructed using a transparent material (e.g., an acrylic resin). FIG. 6A is a plan view of the bottom surface of the light guiding film 180. FIG. 6B is a perspective view of the circular region 6B of the light guiding film 180. The light source 150 is adjacent to one side of the light guiding film 180. In the present embodiment, the bottom surface of the light guiding film 180 has fourteen defined regions from the region A to the region N, for example, their width is about 10 cm. A plurality of lenticular lens patterns 205 are disposed on the bottom surface 190 of the light guiding film 180 (not facing the liquid crystal module) such that the lenticular lens patterns 205 are nearly parallel to the light source 150 and are arranged There is a constant interval d1 in each of the areas A to N (i.e., in each area, the interval between adjacent lenticular lenses is the same and constant, but the intervals of the different areas are different). In this embodiment, the widths d2 and heights d3 of the lenticular lenses are the same and constant, and at least some of the lenticular lenses do not intersect each other (for example, in a region near the region A). In the embodiment shown in Figures 6A and 6B, portions of the arcuate surfaces of the lenticular lenses may overlap or intersect each other (e.g., in a region proximate to region N).

Table 1 shows the initial design dimensions of the light directing film 180. As shown in Table 1, the variables d2, d3, and R will remain constant, while d1 in the different regions A to N will be different. The uniformity of light output from this light-guide film design is not ideal; for example, according to the "13-point" test used in the industry, the uniformity of brightness distribution is only about 30%.

This experiment has found that increasing the radius of curvature (R) (the value of d2 will also increase corresponding to the increase of R), and keeping the value of R constant in all 14 previously defined areas A to N, the light diffusion caused by internal reflection A preferred brightness uniformity (for example, 75%) is achieved in the light directing film. By further fixing the (d1+d2) value and the depth d3 of the lenticular lenses, the design of the light directing film is further optimized, and the brightness uniformity is increased from 30% to 40%.

For designs with more degrees of freedom, the combination of these variables can be adjusted. By fixing the (d1+d2) and R values, the parameters d2 and d3 are further adjusted and achieve a brightness uniformity of 40% to 68%. To optimize the d1+d2 value and the d3 value, a relationship can be developed: by using this optimization relationship, brightness uniformity (for example, more than 75%) can be further improved.

By using the light guiding film structure described above, the brightness is more evenly distributed in the LCD display area. Furthermore, referring back to FIG. 2, a reflective member (eg, reflective sheet 22) is incorporated into the backlight module 14 by wrapping or surrounding the light directing film 18. The reflective sheet 22 helps collect light that escapes from the light directing film 18 and reflects this light back into the light directing film 18. Thereby, the light recycling function can further achieve the purpose of further optimizing the brightness of the backlight module 14.

In accordance with the present invention, a light directing film (e.g., 18 in Fig. 2) includes a structured cylindrical light conditioning surface that, when applied to an LCD, improves the light output distribution of the plane of the light directing film. A novel LCD incorporating a novel optical substrate in accordance with the present invention can be deployed in an electronic device.

The optical substrate according to the present invention can be used to be deployed on a display (for example, a television, a notebook computer, a screen, a portable device (for example, LCDs in cellular phones, digital cameras, PDAs, and the like to make these displays brighter.

As shown in FIG. 8, an electronic device 110 (which may be one of the following: PDA, mobile phone, television, display screen, portable computer, refrigerator, etc.) includes an embodiment in accordance with an embodiment of the present invention. A novel backlit LCD 10. The LCD 10 includes the novel light directing film described above. The electronic device 110 may further include a user input interface, such as buttons and buttons (shown generally by block 116) in a suitable housing; and image data control electronics, for example, for managing image data flowing to the LCD 10. The controller (shown generally by block 112); electronic components specific to the electronic device 110, which may include a processor, an A/D converter, a memory device, a data storage device, etc. (shown generally by block 118); And a power source, such as a power supply, a battery, or an external power outlet (shown generally by block 114), which are well known in the art.

Although the invention has been described in connection with an LCD device; however, the light directing film can be applied to other applications. The light guide form of the present invention may be a flexible or rigid film, sheet, plate, and the like having a cylindrical structure surface, in addition to which it may have a reversed structure surface.

Those skilled in the art will appreciate that various modifications and changes can be made in the structure and process of the present invention without departing from the scope or spirit of the invention. The present invention is intended to cover various modifications and alternatives within the scope of the appended claims.

1‧‧‧Reflective film

2‧‧‧V-cutting light guide plate

3‧‧‧ inverse film

4‧‧‧Diffuser film

5‧‧‧Line source/reflector

10‧‧‧ Backlit LCD

12‧‧‧LCD module

14‧‧‧Backlight module

16‧‧‧Line light source

17‧‧‧ reflector

18‧‧‧Light Guide Film

19‧‧‧ substrate layer

20‧‧‧Light adjustment structure

21‧‧‧ lenticular lens

22‧‧‧Reflective sheet

24‧‧‧ trench

26‧‧‧Microelectronic substrate

27‧‧‧Diffuser

28‧‧‧Micro-substrate

40‧‧‧ cylindrical surface

41‧‧‧ lenticular lens

42‧‧‧ Basement membrane

44‧‧‧稜鏡 surface

45‧‧‧Edge

46‧‧‧ spike

47‧‧‧ Valley

48‧‧‧Light Guide Film

49‧‧‧ substrate layer

50‧‧‧ cylindrical surface

51‧‧‧ lenticular lens

52‧‧‧ basement membrane

54‧‧‧稜鏡 surface

55‧‧‧Edge

58‧‧‧Light Guide Film

59‧‧‧ substrate layer

110‧‧‧Electronic devices

112‧‧‧Image data control electronic components

114‧‧‧Power supply

116‧‧‧User input interface

118‧‧‧Electronic components

150‧‧‧Light source

180‧‧‧Light Guide Film

190‧‧‧ bottom surface

205‧‧‧ lenticular lens pattern

510‧‧‧ substrate layer

520‧‧‧ lenticular lens

522‧‧‧Cylinder

524‧‧‧ convex curved surface

FIG. 1 is a schematic structural view of a prior art backlight module.

2 is a schematic structural view of an LCD incorporating a light guiding plate according to an embodiment of the present invention.

Figure 3 is a cross-sectional view showing the surface profile of a cymbal and a lenticular lens.

4 is a perspective view of a light directing film in accordance with another embodiment of the present invention.

Figure 5 is a perspective view of a light directing film in accordance with yet another embodiment of the present invention.

Figure 6A is a bottom view of a light directing film in accordance with a further embodiment of the present invention; and Figure 6B is a perspective view of the light directing film of Figure 6A.

Figure 7 is a cross-sectional view of a light directing film for explaining structural parameters.

8 is an electronic device including an LCD panel incorporating the novel light directing film of the present invention, in accordance with an embodiment of the present invention.

40‧‧‧ cylindrical surface

41‧‧‧ lenticular lens

42‧‧‧ Basement membrane

44‧‧‧稜鏡 surface

45‧‧‧Edge

46‧‧‧ spike

47‧‧‧ Valley

48‧‧‧Light Guide Film

49‧‧‧ substrate layer

40‧‧‧ cylindrical surface

41‧‧‧ lenticular lens

42‧‧‧ Basement membrane

44‧‧‧稜鏡 surface

45‧‧‧Edge

Claims (27)

A light guide comprising a body, wherein the body includes a first surface, a second surface opposite the first surface, and a side surface connecting the first surface and the second surface, wherein the second portion of the body The surface is constructed to have a plurality of protruding light adjustment portions extending from a first edge of the second surface to a second edge of the second surface, wherein the second edge is opposite the first edge, wherein Each of the two adjacent protruding light adjusting portions in the protruding light adjusting portion has a spacing portion, wherein the protruding light adjusting portions can guide the light received by the side surface such that the guided light is mainly caused by the main body The first surface is output. The light guide of claim 1, wherein the body comprises: a substrate; and a structural layer disposed on the substrate to define the protruding light adjusting portions. The light guide of claim 1, wherein the first surface comprises a plurality of microstructures. A light guide according to item 3 of the patent application, wherein the microstructures comprise a plurality of 稜鏡 structures. The light guide of claim 2, wherein the material of the substrate is the same as the material of the structural layer. The light guide of claim 2, wherein the material of the substrate is different from the material of the structural layer. The light guide of claim 2, wherein the refractive index of the substrate is different from the refractive index of the structural layer. The light guide of claim 7, wherein the difference between the refractive index of the substrate and the refractive index of the structural layer is in the range of 0.001 to 0.6. The light guide of claim 1, wherein the protruding light adjusting portions have the same height. The light guide of claim 1, wherein the protruding light adjusting portions have the same width. The light guide of claim 1, wherein at least a portion of the protruding light adjusting portions have the same interval between adjacent protruding light adjusting portions. The light guide of claim 1, wherein at least a portion of the protruding light adjusting portions have different intervals between adjacent protruding light adjusting portions. The light guide of claim 1, wherein each of the protruding light adjusting portions has a convex surface extending from a reference plane, wherein the reference The plane is defined by the spacing portions. The light guide of claim 1, wherein when the distance between the spacer portion and the side surface of the received light is increased, the interval between the adjacent protruding light adjusting portions is gradually decreased. The light guide of claim 1, wherein each of the protruding light adjusting portions protrudes above the spacing portion. The light guide of claim 1, wherein each of the protruding light adjusting portions is a convex lens. For example, the light guide of claim 1 is wherein the spacing portion is flat. A light guide according to claim 1, further comprising a reflective member disposed above the second surface of the body, wherein the protruding light adjusting portion and the reflective member are capable of guiding light received by the side surface to enable the light The guided light is primarily output by the first surface of the body. A light guide comprising a body, wherein the body includes a first surface, a second surface opposite the first surface, and a side surface connecting the first surface and the second surface, wherein the second portion of the light guide The surface is constructed to have a plurality of protruding strip-like portions extending in a first direction, wherein each of the protruding strip portions There is a spacing portion between adjacent protruding strip portions, wherein the protruding strip portions are capable of directing light received by the side surface such that the guided light is primarily output by the first surface of the body. The light guide of claim 19, wherein the body comprises: a substrate; and a structural layer disposed on the substrate to define the protruding strip portions. A light guide according to claim 19, wherein each of the protruding strip portions has a convex surface extending from a reference plane, wherein the reference plane is defined by the spacer portions. The light guide of claim 19, wherein when the distance between the spaced portion and the side surface of the received light is increased, the spacing between adjacent protruding strip portions is gradually reduced. The light guide of claim 19, wherein each of the protruding strip portions protrudes above the spacing portion. A light guide according to claim 19, wherein each of the protruding strip portions is a convex lens. For example, the light guide of claim 19, wherein the interval portion is flat. A light guide according to claim 19, further comprising a reflective member disposed above the second surface of the body, wherein the protruding strip portions and the reflective member are capable of guiding light received by the side surface such that The guided light is primarily output by the first surface of the body. A method of fabricating a light guide comprising: providing a body, wherein the body includes a first surface, a second surface opposite the first surface, and a side surface joining the first surface and the second surface; Forming the second surface of the body into a plurality of protruding light adjustment portions having a second edge extending from a first edge of the second surface to the second surface, wherein the second edge is opposite the first edge An edge, wherein each of the two adjacent protruding light adjusting portions has a spacing portion between the protruding light adjusting portions; wherein the protruding light adjusting portions are capable of guiding light received by the side surface to cause the guided light Mainly output by the first surface of the body.