JP2009528571A - Optical display with grooved optical plate - Google Patents

Abstract

  The display system includes a light source, a display panel, and a light management layer array disposed between the light source and the display panel. The light source illuminates the display panel through the light management layer array. The light management layer array includes a grooved plate having a front layer facing the display panel, a back layer facing the light source, and a plurality of connecting members connecting the front and back layers. In some embodiments, the fluted plate includes a first light management layer, a transverse member substantially parallel to the first light management layer and spaced from the first light management layer, the transverse member and the first A first connecting member array for connecting the light management layers.

Description

  The present invention relates to an optical display and more particularly to a display system illuminated from the back, which can be used for LCD monitors and LCD televisions.

  Liquid crystal displays (LCDs) are optical displays used in devices such as laptop computers, handheld calculators, digital watches and televisions. Some LCDs include a light source located on the side of the display, along with a light guide that is arranged to direct light from the light source to the back of the panel. Some other LCDs, for example, some LCD monitors and LCD televisions (LCD-TVs), are directly illuminated using a number of light sources located behind the LCD panel. The required light output to achieve a certain level of display brightness increases with the square of the display size, whereas the space available to place the light source along the side of the display is This configuration is becoming increasingly popular as the display becomes larger, since it only increases linearly with size. In addition, some LCD applications, such as LCD-TV, require the display to be bright enough to be viewed from a greater distance than other applications. The required viewing angle is generally different from that for LCD monitors and handheld devices.

  Some LCD monitors and most LCD-TVs are typically illuminated from behind by a number of cold cathode fluorescent lamps (CCFLs). These light sources are linear and extend the full width of the display, so that the back of the display is illuminated with a series of bright elongated strips separated by black portions. Such an illumination profile is undesirable and therefore a diffuser plate is used to smooth the illumination profile behind the LCD device.

Currently, LCD-TV diffuser plates are a polymer matrix of polymethyl methacrylate (PMMA), poly (carbonates), cycloolefins combined with various dispersed phases including glass, polystyrene beads, and C _a CO ₃ particles. Random copolymers of polymethyl methacrylate or polystyrene are employed. These plates often deform or warp after being exposed to the high temperature of the lamp. In addition, some diffusion plates have diffusion characteristics that vary spatially across their width in an attempt to make the illumination profile at the back of the LCD panel more uniform. Such non-uniform diffusers are sometimes referred to as printed pattern diffusers. Since diffusion patterns must be resisted to the illumination source when assembled, they are expensive to manufacture and expensive to manufacture. In addition, customized extrusion compounding is required to distribute the diffusing particles uniformly throughout the polymer matrix, further increasing costs.

  Further, to prevent warping or other types of physical deformation, the diffuser plate must be of a minimum thickness with respect to its height and width. As the size of the display increases, this means that the diffuser plate will also become thicker, thus increasing the weight of the display.

  One embodiment of the present invention is directed to a display system having a light source, a display panel, and a light management layer array disposed between the light source and the display panel. The light source illuminates the display panel through the light management layer array. The light management layer array includes a grooved plate having a front layer facing the display panel, a back layer facing the light source, and a plurality of connecting members connecting the front and back layers.

  Another embodiment of the invention is directed to a light management device comprising a grooved layer. The grooved layer is substantially parallel to the first light management layer, the first light management layer, the transverse member spaced from the first light management layer, and the transverse member as the first light management layer. A first connecting member array to be connected.

  These and other aspects of the present application will be apparent from the detailed description below. However, the above summary should in no way be construed as a limitation on the claimed subject matter, which is defined only by the appended claims and may be amended during execution.

  The present invention is applicable to liquid crystal displays (LCD or LC displays) and is used for LCDs that are directly illuminated from behind and edge illuminated LCDs such as LCD monitors and LCD televisions (LCD-TVs). Applicable to LCD.

  Diffuser plates currently used in LCD-TV are based on polymer matrices, such as polymethyl methacrylate (PMMA), polycarbonate (PC), or cycloolefins, which are formed as rigid sheets. This sheet contains diffusing particles, for example, organic particles, inorganic particles or spaces (bubbles). These plates often deform and warp after being exposed to the high temperatures of the light source used to illuminate the display. These plates are also more expensive to make and assemble into the final display device.

  The present application discloses a directly illuminated LCD device having a light management layer array disposed between the LCD panel itself and the light source. The light management layer arrangement can comprise a diffusing layer configured to provide a direct illumination LC display whose transmittance and haze level are relatively uniform in brightness across the display. .

  A schematic exploded view of a representative direct illumination LC display 100 is shown in FIG. Such a display device 100 may be used, for example, in an LCD monitor or LCD television. The display device 100 is based on the use of an LC panel 102 that typically includes a layer of LC 104 disposed between panel plates 106. The plate 106 is often formed of glass and may include an electrode structure and alignment layer on the inner surface of the plate 106 to control the alignment of the liquid crystals in the LC layer 104. This electrode structure is generally arranged so as to define an LC layer region in which the LC panel pixel and the alignment of the liquid crystal can be controlled independently of the adjacent region. Color filters may be included in one or more plates 106 to add color to the displayed image.

  The upper absorbing polarizer 108 is disposed on the LC layer 104 and the lower absorbing polarizer 110 is disposed below the LC layer 104. In the illustrated embodiment, the upper and lower absorbing polarizers are located outside the LC panel 102. The absorbing polarizers 108, 110 and the LC panel 102 together control the transmission of light from the backlight 112 through the display 100 to the viewer (viewer). In some LC displays, the absorbing polarizers 108, 110 may be arranged with their transmission axes vertical. When the pixels of the LC layer 104 are not driven, the polarization of light passing therethrough may not be changed. Accordingly, light passing through the lower absorbing polarizer 110 is absorbed by the upper absorbing polarizer 108 when the absorbing polarizers 108, 110 are aligned vertically. On the other hand, when the pixel is driven, the polarization of the light passing therethrough is rotated, so that at least some light transmitted through the lower absorbing polarizer 110 is also transmitted through the upper absorbing polarizer 108. For example, selective driving of different pixels of the LC layer 104 by the controller 114 results in light passing from the display at a particular desired location, thus forming an image viewed by the viewer. This controller may comprise, for example, a television controller that receives and displays a computer or television image. One or more optional layers 109 may be provided over the upper absorbing polarizer 108, for example to provide mechanical and / or environmental protection to the display surface. In one exemplary embodiment, layer 109 may include a hard coat on absorbing polarizer 108.

  It will be appreciated that certain types of LC displays may operate in different ways than those described above. For example, absorbing polarizers may be aligned in parallel, and the LC panel may be undriven to rotate the polarization of light. Nevertheless, the basic structure of such a display remains similar to that described above.

  The backlight 112 includes a number of light sources 116 that generate light that illuminates the LC panel 102. A linear, cold cathode fluorescent tube extending across the display device 100 is commonly used as the light source 116 in the display device 100. However, other types of light sources such as filaments or arc lamps, light emitting diodes (LEDs), lasers, thin fluorescent panels or external fluorescent lamps may be used. The light sources listed here are not intended to be limiting or exhaustive, but are merely intended to be representative.

  The backlight 112 may also include a reflector 118 for reflecting light propagating downward from the light source 116 in a direction away from the LC panel 102. This reflector 118 is also useful for recycling light in the display device 100, as will be described below. The reflector 118 may be a specular reflector or a diffuse reflector, or may be a diffuse reflector. One example of a specular reflector that may be used as reflector 118 is Vikuiti ™ Enhanced Specular Reflection (available from 3M Company, St. Paul, Minn.). ESR) film. Examples of suitable diffuse reflectors include polymers that are packed with diffusely reflective particles such as titanium dioxide, barium sulfate, calcium carbonate, such as polyethylene terephthalate (PET), polycarbonate (PC), polypropylene, polystyrene, etc. Is mentioned. Other examples of diffuse reflectors, including microporous materials and fine fiber containing materials, are described in US Pat. No. 6,780,355 (Kretman et al.).

  The light management layer array 120 is disposed between the backlight 112 and the LC panel 102. The light management layer affects light propagation from the backlight 112 to improve the operation of the display device 100. For example, the light management layer array 120 may include a diffusion layer 122. This diffusion layer 122 is used to diffuse the light received from the light source, which results in an improvement in the uniformity of the illumination light incident on the LC panel 102. As a result, this results in a more uniformly bright image being perceived by the viewer. The diffusion layer 122 may include bulk diffusion particles distributed throughout the layer, or may include one or more surface diffusion structures, or combinations thereof.

  The light management layer array 120 may also include a gain diffuser, a layer that diffuses light generally in the viewing direction. In some embodiments, the gain diffuser contains transparent particles that protrude from the surface of the film, thus providing optical output for light passing through the particles. This reduces the light divergence angle, resulting in an increase in on-axis brightness, which may be considered a benefit. Several types of gain diffusers are described in more detail in US Pat. No. 6,572,961 (Koyama et al.).

  The light management layer array 120 may also include a reflective polarizer 124. The light source 116 typically generates unpolarized light, but the lower absorbing polarizer 110 only transmits a single polarization state, so that about half of the light generated by the light source 116 is transmitted to the LC layer 104. do not do. However, this reflective polarizer 124 may be used to reflect light that is otherwise absorbed by the lower absorbing polarizer, so that this light is between the reflective polarizer 124 and the reflector 118. May be reused by reflection. At least a portion of the light reflected by the reflective polarizer 124 may be depolarized and then to the reflective polarizer 124 in a polarization state that is transmitted through the reflective polarizer 124 and the lower absorbing polarizer 110 to the LC layer 104. Returned. In this way, the reflective polarizer 124 may be used to increase the rate at which light emitted by the light source 116 reaches the LC layer 104, and thus the image created by the display device 100 is brighter.

  Any suitable type of reflective polarizer may be used, for example, a multilayer optical film (MOF) reflective polarizer; a diffusely reflective polarizing film (DRPF) such as a continuous dispersive phase polarizer, a wire grid reflective polarizer or a cholesteric reflective polarizer It's okay.

  Both MOF and continuous dispersive phase reflective polarizers transmit light in orthogonal polarization states while selectively reflecting light in one polarization state between at least two materials, usually polymeric materials. Rely on the difference in refractive index. Some examples of MOF reflective polarizers are described in co-owned US Pat. No. 5,882,774 (Jonza et al .. Commercially available examples of MOF reflective polarizers include the State of Minnesota Vikuiti (TM) DBEF-D200 and DBEF-D440 multilayer reflective polarizers with a diffusing surface available from 3M Company, St. Paul.

  Examples of suitable DRPF include continuous / dispersed phase reflective polarizers described in co-owned US Pat. No. 5,825,543 (Ouderkirk et al.) And, for example, co-owned US Pat. No. 5,867,316. And a diffuse reflection type multilayer polarizer described in (Carlson et al.). Another suitable type of DRPF is described in US Pat. No. 5,751,388 Larson.

  Some examples of suitable wire grid polarizers include those described in US Pat. No. 6,122,103 (Perkins et al.). Among them, wire grid polarizers are commercially available from Moxtek Inc., Orem, Utah.

  Some examples of suitable cholesteric polarizers are those described, for example, in US Pat. No. 5,793,456 (Broer et al.) And US Pat. No. 6,917,399 (Pekorny et al.). Is mentioned. Cholesteric polarizers are often provided with an output quarter wave retarding layer so that the light transmitted by the cholesteric polarizer can be converted to linearly polarized light.

  The light management layer array 120 also includes a brightness enhancement layer 128. The brightness enhancement layer includes a surface structure that changes the direction of the light deviated from the axis to a direction closer to the axis of the display. This increases the amount of light propagating on-axis through the LC layer 104, thus improving the brightness of the image viewed by the viewer. An example is a prismatic brightness enhancement layer having a significant number of prismatic protrusions that redirect the illumination light through refraction and reflection. Prism-like brightness enhancement layers that can be used in display devices include, for example, BEFII 90/24, BEFII 90/50, BEFIIIM 90/50, and BEFIIIT, available from 3M Company, St. Paul, Minn. And the Vicuity ™ BEFII and Vicuity BEFIII families of prismatic films.

  The light management layer array 120 may also include a support layer 130 that may be used to provide support for other light management layers. Depending on the arrangement, one of the other light management layers may be integrated with the support layer 130. For example, some existing televisions contain diffusion particles in a relatively thick (2-3 mm), rigid polymer sheet, thus combining the function of providing support and optical diffusion in a single layer.

  The support layer 130 advantageously comprises a grooved plate, which is a plate with a groove or space between the two surfaces of the plate. A cross-sectional view of an exemplary grooved plate 200 is schematically illustrated in FIG. 2A. The grooved plate 200 includes a first layer 202 and a second layer 204, and a connecting member 206 that connects the first and second layers 202 and 204. This open space 208 surrounded by the connecting member 206 and the first and second layers 202, 204 may be considered a groove.

  The fluted plate 200 is self-supporting and in some exemplary embodiments is used to provide support to other light management layers. The fluted plate 200 may be made of any suitable material, for example an organic material such as a polymer. For example, the grooved plate 200 may be formed using any suitable method such as extrusion or molding.

  The thickness of the fluted plate 200 and the size of the groove 208 may be selected depending on the particular application. For example, the fluted plate may be several mm thick, for example in the range of approximately 1 mm to 4 mm, or thicker. The fluted plate 200 may also be thinner, for example having a thickness of about 50 μm or more. Further, the center-to-center distance of the groove 208 may be selected to be any suitable value. For example, the spacing may be in the range of about 1-4 mm or beyond. In other embodiments, the groove spacing may be less than this, for example, as low as 50 μm or less.

  The use of a fluted plate can reduce the weight of a display system such as a television. For example, a 101.6 cm (40 inch) LCD-TV, a conventional solid diffuser plate typically weighs about 1 kg (2.3 pounds) and accounts for about 5% of the total weight of the television. . A fluted plate weighs only a small portion of a comparable solid plate, usually about 25%, so the fluted plate is only about 1% of the total weight of the television.

  In addition, the fluted plate has the mechanical advantage of an “I-beam” with upper and lower plates and connecting members separated by an air space. Thus, the fluted plate provides a high resistance to warping and twisting under the high illumination conditions typical of many display systems.

  The direction of the groove may be oriented in a desired direction with respect to the light source. For example, if the light source is elongated as in most fluorescent lamps, the grooves may be oriented parallel to the light source or not parallel. In a given design of the light source and grooved plate, the specific orientation between the light source and the groove also has improved illumination uniformity and improved thermal response, eg warpage, curl, etc. May be provided.

  Suitable polymeric materials for the fluted plate may be amorphous or semi-crystalline and may include homopolymers, copolymers or mixtures thereof. Polymer foam may also be used. Examples of polymeric materials include amorphous polymers such as poly (carbonates) (PC); poly (styrene) (PS); acrylic acids, eg, Cyr Industries, Rockaway, NJ Acrylic sheets supplied under the ACRYLITE® brand by: acrylic copolymers such as isooctyl acrylate / acrylic acid; poly (methyl methacrylate) (PMMA); PMMA copolymers; cycloolefins; cycloolefin copolymers Acrylonitrile butadiene styrene (ABS); Styrene acrylonitrile copolymers (SAN); Epoxys; Poly (vinylcyclohexane); PMMA / poly (vinyl fluoride) mixtures; Poly (phenylene oxide) alloys; styrene block copolymers; polyimide; polysulfone; poly (vinyl chloride); poly (dimethylsiloxane (PDMS); polyurethanes; poly (carbonate) / aliphatic PET mixtures; Semi-crystalline polymers such as poly (ethylene) (PE); poly (propylene) (PP); olefin copolymers such as PP / PE copolymers; poly (ethylene terephthalate) (PET); poly (ethylene naphthalate) ) (PEN); polyamides; ionomers; vinyl acetate / polyethylene copolymers; cellulose acetate; cellulose acetate butyrate; fluoropolymers; poly (styrene) -poly (ethylene) copolymers; PET and PEN copolymers; One of a kind Examples include, but are not limited to, mixtures containing more than one species.

  Some exemplary embodiments of the fluted plate 200 include a polymeric material that is substantially transparent to light. Some other exemplary embodiments may include, for example, a diffusible material in a fluted plate 200 that uses a polymer matrix containing diffusing particles. The polymer matrix may be any suitable type of polymer that is substantially transparent to visible light, such as any of the polymeric materials listed above.

The diffuser particles may be any type of particle useful for diffused light, for example transparent particles whose refractive index is different from the surrounding polymer matrix, diffusely reflective particles, or voids or bubbles in the matrix. Examples of suitable transparent particles include solid or hollow inorganic particles such as glass beads or glass shells, solid or hollow polymer particles such as solid polymer spheres or polymer hollow shells. Examples of suitable diffuse reflective particles include particles or beads such as PS, PMMA, polysiloxane, titanium dioxide (TiO ₂ ), calcium carbonate (CaCo ₃ ), barium sulfate (BaSO ₄ ), magnesium sulfate (MgSO ₄ ). Can be mentioned. In addition, voids in the polymer matrix may be used to diffuse the light. Such voids can be filled with a gas, such as air or carbon dioxide.

  Other additives may be provided to the fluted plate. For example, the grooved plate may include an antioxidant such as Irganox 1010 available from Ciba Specialty Chemicals, Tarrytown, NY. Other examples of additives include weathering agents, UV absorbers, hindered amine light stabilizers, dispersants, lubricants, antistatic agents, pigments or dyes, nucleating agents, flame retardants, foaming agents, or nanoparticles. May include more than one.

  The entire fluted plate 200 may be formed of a diffusing material, or selected portions of the fluted plate 200 may be made of a diffusing material. For example, the first layer 202 or the second layer 204 may be formed of a diffusing material while the remaining portion of the plate 200 is formed of another material. In other embodiments, both the first and second layers 202, 204 may be formed of a diffusing material. As illustrated in FIG. 1, when a fluted plate 200 formed of a diffusible material is used in a display system, the fluted plate provides mechanical support and provides a diffusing function, A separate diffusion layer is omitted.

  In other exemplary embodiments, the fluted plate 200 may include a diffusion layer 210, for example, as schematically illustrated in FIG. 2B. This diffusion layer 210 may be attached to either the first layer 202 or the second layer 204. In addition, in some embodiments, a diffusion layer may be attached to each of the first and second layers 202,204. The diffusion layer 210 may be attached to the grooved plate 200 using an adhesive layer (not shown), or in other embodiments the diffusion layer 210 itself is attached to the grooved plate 200. It may be an adhesive layer.

  Commercial materials suitable for use in the diffusion layer include 3M ™ Scotchcal ™ diffusion film, type 3635-available from 3M Company, St. Paul, Minnesota. 70 and 3635-30, and 3M ™ Scotchcal ™ ElectroCut ™ graphic film, type 7725-314. Other commercially available diffusers include 3M ™ VHB ™ acrylic foam tape no. Acrylic foam tape, such as 4920.

  In some exemplary embodiments, the diffusion layer 210 has diffusion characteristics that are uniform across its width, in other words, the amount of diffusion experienced by light is the same for each point across the width of the diffusion layer 210.

This diffusion layer 210 may be patterned as desired, or supplemented or replaced with an optional patterned diffuser 210a. This optional patterned diffuser 210a may include a patterned diffused surface or printed layer of diffuser, such as, for example, titanium dioxide (TiO ₂ ) particles. The patterned diffuser 210 a may be placed on the diffusion layer 210 between the diffusion layer 210 and the grooved plate 200. In addition, the patterned diffuser may be applied to a fluted plate 200 that is at least partially formed of a diffusing material.

  The grooved plate 200 may be provided with protection means from ultraviolet (UV) light, for example by including a UV absorbing material or a material that is resistant to the effects of UV light. For example, Cyasorb ™ UV-1164 available from Cytec Technology Corporation, Wilmington, Delaware, and Ciba Specialty Chemicals, Tarrytown, NY Suitable UV absorbing compounds are commercially available, including Tinuvin ™ 1577 available from the company. The grooved plate 200 may also include a brightness enhancing phosphor that converts UV light to visible light.

  Other materials may be included in the layer of the fluted plate 200 to reduce the harmful reactions of UV light. An example of such a material is a hindered amine light stabilizing composition (HALS). In general, the most useful HALS are those derived from tetramethylpiperidine and those that can be regarded as polymeric tertiary amines. Suitable HALS compositions are commercially available, for example, from Ciba Specialty Chemicals, Tarrytown, NY, under the trade name “Tinuvin”. One such useful HALS composition is Tinuvin 622. UV absorbing materials and HALS are further described in US Pat. No. 6,613,819 (Johnson et al.).

  In another embodiment, the fluted plate 200 may have two diffusion layers 210, 212 attached to the first and second layers 202, 204 of the fluted plate 200, respectively. The diffusion layers 210, 212 may be applied directly to the corresponding layers 202, 204 of the grooved plate 200, respectively, as shown in FIG. 2C, or use an adhesive layer (not shown). May be attached.

  The two diffusion layers 210, 212 may have the same diffusion characteristics or may have different diffusion characteristics. For example, the diffusion layer 210 may have a different transmittance or haze level than the second diffusion layer 212, or may have a different thickness.

  This optical property of the fluted plate may be uniform across its width, but this is not necessary. In some exemplary embodiments, such as the fluted plate 300 shown in FIG. 3, the amount of diffusion imparted by the fluted plate 300 itself may vary spatially across the width of the plate 300. This may be accomplished, for example, by introducing bulk diffusing particles non-uniformly across the extruded fluted plate. The graph above the grooved plate shows the spatial variation of the single optical path transmittance, T. This single optical path transmission is part of the incident light transmitted through the grooved plate 300, with higher levels of transmission indicating less diffusion and lower levels of transmission indicating more diffusion. In the illustrated embodiment, the periodicity in the spatial variation in transmittance is equal to the separation distance between the connecting members 306. Such spatial variations in diffusion may be useful in reducing non-uniformities in transmitted light brightness due to the coupling member 306. However, there is no requirement that variations in T have this periodicity, and variations in T may have some other periodicity or need not be periodic.

  Another optical property of the fluted plate that can vary across the fluted plate 400 is the refractive index of one or both of the first and second layers 402, 404, as schematically shown in FIG. It is. Such variation may be achieved, for example, by introducing non-uniformly different refractive index materials across the extruded fluted plate. The graph above the fluted plate 400 shows the spatial variation of the refractive index. In the illustrated embodiment, the periodicity of the spatial variation in refractive index is equal to the separation distance between the connecting members 406. Such spatial variation in diffusion may be useful for reducing non-uniformity in the brightness of transmitted light due to the coupling member 406. However, there is no requirement that the refractive index variation have this periodicity, and the refractive index variation may have some other periodicity or need not be periodic.

  In some exemplary embodiments, one or more of the layers of the fluted plate may have a thickness that varies across the plate. For example, in the fluted plate 500 schematically shown in FIG. 5A, the thickness of the first layer 502 is relatively thin at the edges of the plate 500 to relatively thick at the center of the plate 500. While varying to the state, the second layer 504 maintains a constant thickness across its width. Variations in the thickness of the first layer 502 may be used, among other things, to provide additional strength to the plate or to cause variations in the optical properties of the plate. In one exemplary embodiment, when the first layer 502 contains a uniform concentration of bulk diffusible particles, the variation in the thickness of the first layer 502 is to provide spatially varying diffusion characteristics. May be used. In the illustrated embodiment, there is a greater diffusion of light passing through the central portion as compared to the edge of the plate 500.

  In other embodiments, the second layer 504, or both the first and second layers 502, 504, may have a variable thickness. For example, as shown in FIG. 5B, the fluted plate 520 has a first layer 522 of uniform thickness and a second layer 524 of variable thickness. It will be appreciated that the thickness variation of the first and / or second layers 502, 504, 522, 524 may be either periodic or aperiodic.

  In some embodiments, the surface of the material surrounding the space or groove may be parallel or perpendicular to the outer surface of the fluted plate, but this is not a necessary condition. In some exemplary embodiments, the surface of the first or second layer that defines the groove may be non-parallel to the upper surface of the grooved plate. This is schematically illustrated in FIG. 6A for one particular grooved plate 600 where the lower surface 602a of the first layer 602 is the upper surface of the second layer 604 for at least some of the grooves 608. Non-parallel to 604b. As a result, some cross-sectional shapes of the groove 608a are not square or rectangular.

  The lower surface of the groove may also be non-parallel to the lower surface of the second layer. For example, in the embodiment of FIG. 6B, the thickness of both the first and second layers 622, 624 is not uniform across the width of the plate 620. In other exemplary embodiments, the first layer may have a uniform thickness while only the second plate has a non-uniform thickness.

  The groove need not be a quadrilateral shape, and may have another shape. For example, in one exemplary embodiment schematically illustrated in FIG. 7A, the fluted plate 700 has a triangular connecting member 706 that connects between the first and second layers 702, 704. As a result, the groove 708 also has a triangular cross section. In another exemplary embodiment schematically illustrated in FIG. 7B, the fluted plate 720 has upper and lower layers 722, 724 having sinusoidal inner surfaces 722a, 724a that define the grooves 728. . The connecting member 726 is formed when the sinusoidal surfaces coincide.

  In another exemplary embodiment, shown schematically in FIG. 7C, the fluted plate 730 has upper and lower layers 732, 734 that are coupled together via a curved coupling member 736. In the illustrated embodiment, the curved connecting members 736 alternate between one direction of curvature and the opposite direction of curvature to provide a corrugated effect.

  A number of different cross sections may be used for the connecting members and grooves in addition to those illustrated herein. Moreover, the illustrated embodiments are presented for purposes of illustration only and are not intended to limit the scope of the invention to only those cross-sections illustrated herein.

  In some exemplary embodiments, such as the fluted plate 800 shown schematically in FIG. 8A, which shows a plan view of the plate 800, the grooves 808 are straight and arranged parallel to each other. In other exemplary embodiments, such as the slotted plate 820 schematically shown in FIG. 8B, the grooves 828 are straight but parallel to each other and the first group of grooves parallel to each other. Arranged with a second group of grooves 828 that are perpendicular to the group of one. In other embodiments, different grooves may be placed at different angles from each other.

  In some embodiments, the surface of the first or second layer may be flat and may be provided with an anti-reflective coating. In other embodiments, the first and / or second layer may perform an optical function. For example, the outer or inner surface of the first and / or second layer may have a matte finish. In another exemplary embodiment, the first and second layers may be provided with some surface structure. For example, the fluted plate 900 schematically shown in FIG. 9 has first and second layers 902, 904 that are attached together via a connecting member 906. In this particular embodiment, the upper surface 910 of the first layer 902 is provided with a series of prismatic ribs 912. The ribs 912 may be placed parallel to each other, in which case the surface 910 acts like a prism brightness enhancement layer, changing the direction of some off-axis light and causing the rays 914 to As illustrated, it propagates in a direction more parallel to axis 916.

  The grooved plate may have other types of surfaces. In another embodiment, shown schematically in FIG. 10, the first layer 1002 of the fluted plate 1000 has an upper surface 1010 with a series of lenses 1012 that provide optical power to the light 1014 passing through the plate. . The lens 1012 may have a width equal to the spacing between the connecting members 1006, but is not required to have it. The lens 1012 may be a lenticular lens that extends across the width of the plate 1000. This type of lens is particularly well suited for plates made using an extrusion process. Other methods, such as molding, may be used to form the lens 1012.

  Grooved plates may be used to support other optical layers in the display. For example, one or more other layers may be attached to the fluted plate. The following examples are presented to illustrate some possible combinations of other layers and grooved plates. FIG. 11A shows an array of optical layers 1100 having a grooved plate 1101 with a reflective polarizer layer 1110 attached to the upper surface of the grooved plate upper layer 1102. The reflective polarizer layer 1110 may be attached using an adhesive, such as a transparent adhesive or an optical diffusion adhesive. The prismatic brightness enhancement layer 1112 may be attached on the reflective polarizer layer 1110. In some exemplary embodiments, it may be desirable for some light to enter the brightness enhancement layer 1112 through an air interface or an interface that transitions from low to high refractive index. Thus, a layer of low refractive index material, such as a fluorinated polymer, may be placed between the brightness enhancement layer 1112 and the next layer below the brightness enhancement layer 1112.

  In other exemplary embodiments, a void may be provided between the brightness enhancement layer 1112 and the layer below the brightness enhancement layer 1112. One approach to providing a void is to provide a structure on one or both of the brightness enhancement layer 1112 and the opposing surface of the layer below the brightness enhancement layer 1112. In the illustrated embodiment, the lower surface 1114 of the brightness enhancement layer 1112 is structured with a protrusion 1116 that contacts an adjacent layer. The voids 1118 are thus formed between the protrusions 1116 so that light incident on the brightness enhancement layer 1112 at the position between the protrusions 1116 enters through the air interface. In other embodiments, the reflective polarizer layer 1110 may be omitted and the prismatic brightness enhancement layer 1112 may be attached directly to the grooved plate 1101. In some embodiments, the grooved layer 1101 provides optical diffusion, or a single diffusion layer may be provided, eg, (i) a grooved layer and (ii) a reflective polarizer layer 1110 and / or a prism. Attached to the lower layer 1104 of the grooved layer 1101 or to the first layer 1102 of the grooved layer 1101 between the mold brightness enhancement layer 1112.

  Other techniques for creating a void and thus providing an air interface for light incident on the brightness enhancement layer may be used. For example, the brightness enhancement layer may have a flat lower surface and the adjacent layer is structured with protrusions. These and additional techniques are described in US Pat. No. 7,010,212 (Emmons et al.). Any of the grooved plate embodiments described herein may be configured to provide an air interface for light incident on the brightness enhancement layer.

  The order of the films attached to the fluted plate 1101 may be different. For example, the reflective polarizer layer 1110 may be attached to the prismatic surface of the brightness enhancement layer 1112 and the brightness enhancement layer 1112 is attached to the grooved plate 1101. This array 1120 is schematically shown in FIG. 11B. The attachment of optical film brightness enhancement layers to prismatic surfaces is described in detail in US Pat. No. 6,846,089 (Stevenson et al.).

  An exemplary embodiment showing an array 1200 in which one or more films are attached to the lower layer of a fluted plate is schematically illustrated in FIG. 12A. In this embodiment, a reflective polarizer 1210 is attached to the second layer 1204 of the grooved plate 1201 and a prismatic brightness enhancement layer 1212 is attached to the first layer of the grooved plate 1201. An optional diffusing layer 1214 may be attached to the lower surface of the reflective polarizer 1210. In other embodiments, the fluted plate itself may provide some degree of diffusion. In such cases, it may be desired that the grooved plate 1201 does not significantly depolarize the light that has passed through the reflective polarizer 1210.

  Another exemplary embodiment 1220 of a fluted plate 1201 that is attached to a light management film array is schematically illustrated in FIG. 12B. In this embodiment 1220, the diffusion layer 1222 is attached to the grooved plate 1201. The intermediate layer 1224 is disposed on the diffusion layer 1222, and the prismatic brightness enhancement layer 1226 is disposed on the intermediate layer 1224. The diffusion layer 1222 may be, for example, an acrylic foam tape that deforms when the intermediate layer 1224 is pushed into the foam tape, creating a recessed area in which the intermediate layer is placed. The intermediate layer 1224 may have an optical function. For example, the intermediate layer 1224 may be a reflective polarizer film. Examples of other suitable light management film arrays that may be used with fluted plates are described in further detail in US Patent Application Publication No. 2006/0082699 (Gehlsen et al.).

  In addition to molding, there are other methods of making grooved plates. One way is to attach the spine (spine) to another optical film, with the connecting member already applied. This approach is schematically illustrated in FIGS. 13A and 13B. The spine 1302 has an arrangement of cross members 1304 and connecting members 1306. The connecting member 1306 may be integrated with the cross member 1304. For example, the spine 1302 may be formed by molding or extrusion. Spine 1302 may be formed of the same type of material as described above for the grooved plate. Thus, the spine 1302 may be formed of an optically transparent material or an optical scattering material.

  The optical film 1310 is attached to the connecting member 1306. The optical film may be any suitable type of film. For example, the film 1310 may be a prismatic brightness enhancement film, a diffusion film, a reflective polarizer film, a gain diffuser film, a lens film, an absorbing polarizer, a matte film, or the like. In addition, the optical film 1310 may simply be a transparent film. Further, the optical film may also be attached to the spine 1302 below the cross member 1304.

  FIG. 13B shows the optical film 1310 attached to the connecting member 1306. This film 1310 may be attached to the connecting member using any suitable method. For example, the lower surface 1312 of the film 1310 and / or the tip 1314 of the connecting member 1306 may be applied with an adhesive that is cured after the lower surface 1312 and the connecting member tip 1314 are placed in contact. In another approach, where the film 1310 and the connecting member 1306 are both formed of a polymeric material, the film 1310 and the connecting member 1306 may be placed in contact before the respective polymeric material is fully crosslinked, The film 1310 and the connecting member 1306 are then cross-linked together. Several other approaches may be used, for example, contacting the optical film with the molten polymer immediately after extrusion to create a bond between the optical film and the groove. In another approach, the grooves may be heated (after extrusion) and later laminated. Co-extruded grooves may also be used, so that the groove is one material as a substrate (non-adhesive, structural member) and another material co-extruded on the tip (adhesive type) Material).

  After film 1310 is attached, film 1310 and spine 1302 together form a plate having grooves 1316.

  In another embodiment, shown schematically in FIGS. 14A (separated elements) and 14B (elements attached together), the spine 1402 has a set of connecting members 1406a, 1406b on each side of the cross member 1404. Have. The two types of optical films 1410a and 1410b may be attached to each set of the connecting members 1406a and 1406b. The optical films 1406a, 1406b may be any desired type of optical film, such as a transparent film, a diffusion film, a prismatic brightness enhancement film, a reflective polarizing film, and the like.

  After at least one of films 1410a, 1410b is attached to spine 1402, films 1410a and 1410b and spine 1402 together form a plate having grooves 1416.

  One particular embodiment of an optical film array 1500 comprising a spine 1502 of the type shown in FIG. 14B is schematically illustrated in FIG. In this embodiment, the diffusion layer 1510 is attached to the lower connecting member 1506b, and the prismatic brightness enhancement layer 1512 is attached to the upper connecting member. A reflective polarizer layer 1514 may be attached to the structured side of the prismatic brightness enhancement layer 1512 if desired.

  Another illustrative array 1600 is schematically illustrated in FIG. 16 where a reflective polarizer 1514 is disposed between the diffusing layer 1510 and the spine 1502.

  Another approach for attaching the two layers together is to use layers that are interconnectable. For example, the two layers may be mechanically attachable to each other using an attachment mechanism such as that used to seal a food storage bag. An exemplary embodiment of such a mechanism is shown in FIG. 17, which shows portions of the upper and lower layers 1702, 1704. Each layer 1702, 1704 has a respective interconnecting member 1706, 1708 directed to the mating layer. When the two layers 1702, 1704 are pressed together, the interconnecting members 1706, 1708 lock together to form the connecting member. These layers 1702, 1704 may be formed with the respective interconnecting members 1706, 1708 using, for example, an extrusion process. The interconnecting member 1706 may have the same shape as the interconnecting member 1708, but is not required to do so.

  Regardless of whether spines are used to connect the upper and lower layers, the fluted plate may be formed in a partially continuous process. The films forming the upper and lower layers and the optional spine may be removed from their respective rolls and attached together. Once these layers are attached to each other, the resulting grooved product is relatively rigid. Individual plates can be cut from the continuous fluted product.

  Grooved plates may be used to improve thermal management in display systems, such as television displays or monitors. One exemplary embodiment of a display system 1800, shown schematically in FIG. 18, includes one or more light sources 1802, a grooved plate 1804, a light management layer array 1806, a display panel 1808, Is provided. Refrigerant may flow through the grooves in the grooved plate 1804, which results in a lower operating temperature of the display system. The refrigerant may be air, and in some embodiments the air may flow through a vertically oriented groove due to natural convection. In other embodiments, the refrigerant may be forced through the groove by a refrigerant circulator. For example, the fan 1810 may be used to push air through a groove in the grooved plate 1804. In other embodiments, a clear fluid, such as water, may be pushed through the groove by a pump.

  It will be understood that there are a number of different possible arrays within the scope of the present invention where the different layers appear in different orders from the bottom to the top of the array or at different positions relative to the spine.

  The present invention should not be considered limited to the particular embodiments described above, but should be understood to cover all aspects of the present invention as clearly set forth in the appended claims. . Upon review of this specification, various modifications, equivalent processes, and numerous structures to which the present invention can be applied will be readily apparent to those skilled in the art to which the present invention relates. For example, free-standing optical films may also be used in display devices side by side with a fluted plate that is attached with other optical layers. The display may also use more than one grooved plate. The grooves of the multi-grooved plate may be arranged parallel to each other, or the grooves of one plate may face non-parallel to the grooves of another grooved plate. The claims are intended to cover such modifications and devices.

  The present invention will be more fully understood in view of the following best mode for carrying out the invention of various embodiments of the invention in conjunction with the accompanying drawings. In the drawings, like reference numbers indicate like elements.

  While the invention is susceptible to various modifications and alternative forms, specific examples thereof are shown by way of example in the drawings and will herein be described in detail. However, it should be understood that the invention is not intended to be limited to the particular embodiments described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims.

1 schematically shows a display device using a fluted plate. 1 schematically shows a grooved plate. 1 schematically illustrates a grooved plate and an attached optical film. 1 schematically illustrates a grooved plate and an attached optical film. 1 schematically shows a grooved plate having a spatially variable single optical path transmittance. 1 schematically shows a grooved plate having a spatially variable refractive index. 1 schematically shows a fluted plate whose upper and lower layers each have a spatially varying thickness. 1 schematically shows a fluted plate whose upper and lower layers each have a spatially varying thickness. 1 schematically shows a fluted plate whose upper and lower layers each have a spatially varying thickness. 1 schematically shows a fluted plate whose upper and lower layers each have a spatially varying thickness. 1 schematically shows a grooved plate having grooves of different cross-sectional shapes. 1 schematically shows a grooved plate having grooves of different cross-sectional shapes. 1 schematically shows a grooved plate having grooves of different cross-sectional shapes. The top view of the plate with a groove | channel which shows the groove | channel arrange | positioned in parallel is shown typically. Fig. 2 schematically shows a plan view of a grooved plate showing a set of parallel grooves arranged vertically. 1 schematically illustrates a grooved plate with an optically useful surface structure. 1 schematically illustrates a grooved plate with an optically useful surface structure. Fig. 2 schematically shows various optical film arrays comprising grooved plates. Fig. 2 schematically shows various optical film arrays comprising grooved plates. Fig. 2 schematically shows various optical film arrays comprising grooved plates. Fig. 2 schematically shows various optical film arrays comprising grooved plates. The structure of the plate with a groove | channel using the spine attached to an optical film is shown typically. The structure of the plate with a groove | channel using the spine attached to an optical film is shown typically. The structure of the plate with a groove | channel using the double-sided spine attached to an optical film is shown typically. The structure of the plate with a groove | channel using the double-sided spine attached to an optical film is shown typically. Fig. 4 schematically shows different film arrangements made around a double-sided spine. Fig. 4 schematically shows different film arrangements made around a double-sided spine. 1 schematically illustrates the structure of a fluted plate using first and second layers having interconnecting members. 1 schematically illustrates a display system having a flow of heat transfer medium through grooves in a grooved plate.

Claims (19)

A light management unit for use between a display panel and a backlight, the light management unit having a side surface of the display panel for directing a direction toward the display panel and a side surface of the backlight facing the direction of the backlight. And the unit is
A first light management layer, a transverse member substantially parallel to the first light management layer and spaced apart from the first light management layer, and integral with the transverse member; A light management unit, comprising: a grooved layer including: an array of first coupling members attached to the light management layer.   The unit of claim 1, wherein the first light management layer includes one of a diffusion layer, a brightness enhancement layer, and a reflective polarizer layer.   The unit of claim 1, further comprising a second light management layer attached to the grooved layer.   The unit according to claim 3, wherein a second connecting member array connects the second light management layer and the transverse member.   The second light management layer is coupled to the first light management layer such that the first light management layer is located between the cross member and the second light management layer. Item 4. The unit according to Item 3.   The first connecting member is disposed on a side surface of the display panel of the cross member and extends from the cross member; the unit is disposed on a backlight side surface of the cross member; and the cross member The unit of claim 1, further comprising the second coupling member extending from and further comprising a second light management layer attached to the second coupling member. A light source;
A display panel,
A light management layer array disposed between the light source and the display panel, wherein the light source illuminates the display panel through the light management layer array, and the light management layer array is a grooved plate. A light management layer array in which the grooved plate has a front layer facing the display panel, a back layer facing the light source, and a plurality of connecting members connecting the front and back layers; Display system with   The system of claim 7, wherein the light management layer array includes at least one of a reflective polarizer layer, a diffusion layer, and a prismatic brightness enhancement layer.   The system of claim 7, wherein at least a portion of the fluted plate is formed of a diffusing material.   The system of claim 7, wherein the light management layer array further comprises at least one of a diffusion layer, a reflective polarizer layer, and a prismatic brightness enhancement layer.   The system of claim 7, wherein at least one of the front layer and the back layer includes a first light management layer.   The system of claim 11, wherein the first light management layer includes at least one of a prismatic brightness enhancement layer, a diffusion layer, and a reflective polarizer layer.   The connecting member includes a first connecting member and a second connecting member, the first connecting member is attached to the transverse member and connected to the front layer, and the second connecting member is the transverse member. And the first light management layer is attached to one of the first connecting member and the second connecting member, and the first connecting member and the first connecting member are connected to the back layer. The system of claim 11, further comprising a second light management layer coupled to the other of the two coupling members.   The system of claim 7, further comprising a controller coupled to control an image displayed by the display panel.   The system of claim 7, wherein the display panel comprises a liquid crystal display (LCD).   The system of claim 7, further comprising a refrigerant circulator for pushing a cooling medium through a groove in the grooved plate.   The system of claim 16, wherein the refrigerant circulator is a fan and the refrigerant is air.   The system of claim 7, wherein the grooves of the fluted plate are arranged vertically to allow passage of air by natural convection therethrough.   The connecting member includes a first connecting member attached to the front layer and a second connecting member attached to the back layer, and the first connecting member is interconnected with the second connecting member. The system according to claim 7.

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