JP2008112025A - Optical sheet support, backlight for liquid crystal display using the same, liquid crystal display and rear-projection type display - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical sheet support which can support an optical sheet to be used for a display, without having to use a conventional resin plate, is small in thickness, light weight and superior in compactness, the light transmittance and the refractive index difference between members, is superior in light diffusibility than a support imparted with ruggedness, and can be reduced in cost. <P>SOLUTION: The optical sheet support 2 is a support for the optical sheet mounted on the display and has a fabric constituted of fibers, wherein 80-100% of single filaments, constituting the fibers contain light-scattering particles therein and each have a nearly circular cross-sectional shape. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an optical sheet support used for a display and a backlight for a liquid crystal display using the same, and more particularly, an optical sheet support suitable for a backlight for a direct type liquid crystal display and a liquid crystal display using the same. It is related with the backlight etc.

  In recent years, displays using various principles have been used in various applications such as portable devices, televisions, monitors, and notebook computers. In particular, liquid crystal displays (hereinafter referred to as LCDs) are widely used from small screen products for portable devices to large screen products such as monitors and televisions. In the LCD, an image is displayed by providing a backlight, which is a surface light source, on the back side of the screen in order to irradiate the liquid crystal element sandwiched between the polarizing plates uniformly from the back side of the screen.

  Backlights used in such LCDs are roughly classified into two types: (1) a direct type in which one or more fluorescent tubes are arranged directly under the screen, and (2) a light guide plate in which a transparent acrylic plate is processed. Sidelight type that takes out light in the observation direction while spreading the light into a plane using the action of the scattering dots carved in the light guide plate from the fluorescent tube placed on its side There is. These types make use of their respective characteristics, the direct type is a type that can easily cope with an increase in size, and the sidelight type is a type that can easily cope with a reduction in size and thickness.

  These backlights are required not only to receive light from the back side of the screen but also to make the entire screen shine uniformly and brightly. In order to satisfy such requirements, an optical functional sheet (hereinafter, referred to as an optical sheet) such as a light diffusion sheet, a prism sheet, or a brightness enhancement sheet (polarized light separation sheet) is incorporated in the backlight.

  Among these optical sheets, the light diffusion sheet functions as follows. For example, in the case of a direct type backlight, the fluorescent tube is arranged directly under the screen. Therefore, luminance unevenness corresponding to the shape of the fluorescent tube appears remarkably. Therefore, a light diffusing plate (light diffusing sheet) with a thickness of 2 to 3 mm having light scattering properties is arranged on the upper side of the fluorescent tube to shield the fluorescent tube image and equalize the emission distribution of the light emitted from the light diffusing plate. Let For the light diffusion plate for direct type backlight, for example, a resin composition obtained by kneading and mixing a transparent resin such as methacrylic resin and a diffusion component such as silicone resin particles using an injection molding method or an extrusion molding method. A light diffusion plate (light diffusion sheet) made of or the like is used (see Patent Document 1). The light diffusing plate also has a function of supporting an optical sheet such as a prism sheet or a brightness enhancement sheet (polarization separation sheet) laminated thereon.

  However, the use of a light diffusing plate having a thickness of 2 to 3 mm has the following problems. (1) Although it is a big attraction that the liquid crystal display is thin, it becomes thick, and (2) it becomes very heavy when used for a large-sized liquid crystal display suitable for a direct type, and the cost is low. The disadvantage is that it becomes higher.

  Patent Document 2 discloses a structure in which a light diffusion sheet made of a fabric is supported and fixed by a resin plate made of a transparent substrate. However, the technique described in this document does not solve the above-mentioned problem because the resin plate is used, and further, it is necessary to embed, sandwich, and adhere the woven fabric to the resin plate without wrinkles or sagging. In order to use the light scattering due to the difference, there is an annoyance that the relationship between the refractive index of the fabric and the resin plate has to be selected optimally. Furthermore, since the optical sheet is supported in a state where it is raised by the thickness of the resin plate, there is a drawback that the optical sheet becomes far from the light source by the thickness of the resin plate. When the distance from the light source is increased, the intensity of the light is weakened, and the light transmitted through the optical sheet is weakened, so that the screen of the liquid crystal display backlight becomes dark.

Patent Document 3 discloses a light diffusion sheet in which a gap between woven and knitted fabrics is filled with a binder resin. However, although the light diffusion sheet described in this document has unevenness corresponding to the fabric crease formed on the surface thereof, in order to obtain a light diffusion effect, it is bonded to a support such as a film, It is used by being supported by another diffusion plate. That is, since the basic structure is not different from that described in Patent Document 2, it has the same problem as the technique described in Patent Document 2.
JP-A-6-73296 (Claim 1, FIG. 1) JP-A-8-160205 (Claim 1, FIG. 1) Japanese Patent Laying-Open No. 2005-188953 (Claim 1, FIG. 1)

  The present invention eliminates the problems of the prior art, and is a support that can support an optical sheet used in a display without using a resin plate as in the prior art, and is thin, light, and compact. It is an object of the present invention to provide an optical sheet support that is excellent in light transmittance and excellent in light diffusibility than those provided with a difference in refractive index and unevenness between members and capable of reducing costs. .

In order to solve this problem, the present invention is characterized by the following configuration.
(1) A support for an optical sheet equipped in a display, comprising a fabric composed of fibers, wherein 80 to 100% of the single yarn constituting the fibers includes light scattering particles in the fibers, and An optical sheet support having a substantially circular cross-sectional shape.
(2) The optical sheet support according to (1), wherein the light scattering particles are titanium oxide.
(3) The optical sheet support according to (1) or (2), wherein the content of light scattering particles contained in the single yarn is in the range of 0.001 to 0.3 wt% per single yarn weight.
(4) The optical sheet support according to any one of (1) to (3), wherein the total fineness of fibers constituting the fabric is in the range of 5 to 450 dtex.
(5) The optical sheet support according to any one of (1) to (4), wherein the fabric is a woven fabric.
(6) The optical sheet support according to any one of (1) to (5), wherein luminance unevenness of the fabric is in a range of 50 to 350 cd / m ² .
(7) The optical sheet support according to any one of (1) to (6), wherein the fabric is subjected to ultraviolet resistance treatment.
(8) The optical sheet support according to any one of (1) to (7), which is mounted on a backlight of a liquid crystal display.
(9) A backlight for a liquid crystal display comprising the optical sheet support according to any one of (1) to (8).
(10) A liquid crystal display comprising the liquid crystal display backlight according to (9).
(11) A rear projection display comprising the optical sheet support according to any one of (1) to (8).

  According to the optical sheet support of the present invention, since the optical sheet equipped in the display is supported by the cloth instead of the resin plate, it can be supported at a position closer to the light source. In addition, the optical sheet support of the present invention is thin and light, has excellent light transmittance, is compact and has excellent impact resistance, and can reduce costs. And since 80 to 100% of the single yarn of fibers constituting the fabric contains light scattering particles in the fiber and has a substantially circular cross-sectional shape, light diffusion is achieved while increasing the amount of light transmitted through the support and the luminance. The brightness can also be improved and luminance unevenness can be suppressed. As a result, even when used in LCD backlights, LCD displays, rear projection displays, etc., it is possible to suppress brightness unevenness while increasing brightness, and to be lightweight and compact, with excellent impact resistance, and low price. Can be.

  Hereinafter, the best mode for carrying out the present invention will be described.

  The optical sheet support according to the present invention is a support for an optical sheet provided in a display, and has a fabric composed of fibers as a basic structure. That is, according to the optical sheet support of the present invention (hereinafter simply referred to as the support), the optical sheet mounted on the display is not a resin plate, but is described below when the display member such as a backlight is assembled. Support with a fabric. As a result, in particular, the optical sheet provided in the display can be supported at a position closer to the light source (including the light guide plate and the reflection sheet). And since it is a fabric, it is thin, light and excellent in compactness, and since it is not cracked at the time of an assembly and conveyance, it is excellent in impact resistance, and it also becomes possible to reduce cost.

  In the fabric constituting the support of the present invention, the cross-sectional shape of the single yarn constituting the fiber is substantially circular. Therefore, it has the feature that the scattered light is small and the straight light is increased, and the fiber gap is likely to be large and the light transmittance is excellent.

  In the present invention, the single yarn material includes acrylic fibers such as polymethyl methacrylate and polyacrylonitrile, polyester fibers such as polyethylene terephthalate, polytrimethylene terephthalate, and polybutylene terephthalate, polyamide fibers such as nylon 6 and nylon 66, and polyurethane fibers. Polyolefin fibers such as polyethylene and polypropylene, polyimide fibers, polyacetal fibers, polyether fibers, polystyrene fibers, polycarbonate fibers, polyester amide fibers, polyphenylene sulfide fibers, polyvinyl chloride fibers, polyether ester fibers, polyvinyl acetate fibers, polyvinyl butyral Fiber, polyvinylidene fluoride fiber, ethylene-vinyl acetate copolymer fiber, fluororesin fiber, and styrene-acrylic copolymer Fibers may contain any synthetic fiber such as aramid fiber, 1 to type may be made of synthetic fibers, it may be composed of two or more synthetic fibers.

  However, polyester fibers, polyphenylene sulfide fibers, fluororesin fibers, and the like can be preferably used from the viewpoint of moisture absorption stability, thermal stability, and the like, and polyester fibers can be preferably used from the viewpoint of versatility.

  The fineness of the single yarn is preferably 0.001 dtex or more and 10 dtex or less. This is because if it is less than 0.001 dtex, scattered light between single yarns increases and transmitted light tends to decrease, and if it exceeds 10 dtex, the yarn becomes thick and the transmitted light passing through the fibers tends to decrease.

  In the present invention, it is necessary that substantially all of the single yarn constituting the fabric, that is, 80% or more has a “substantially circular cross section”. In addition, the measurement of the ratio of the fiber which has a substantially circular cross-sectional shape is performed as follows. First, when the fabric is a knitted or woven fabric, the fabric is loosened, and a cross section of the fibers constituting the fabric is enlarged and photographed with an optical microscope or a reflection electron microscope so that the fiber diameter is about 1 cm. On the other hand, in the case of non-woven fabric, a sample with a width of 5 mm is cut out from the fabric (the length depends on the measuring device), and the cross section of the sample is enlarged with an optical microscope or a reflection electron microscope so that the fiber diameter can be seen about 1 cm. Take a photo. From these photographs, an inscribed circle and a circumscribed circle of each cross section of the fiber are taken, and if the ratio of the circumscribed circle / inscribed circle is 1.1 or less, it is judged as a substantially circular cross section, and if it exceeds 1.1, it is judged as an irregular cross section. The operation is repeated for all the photographed cross sections, and the ratio is calculated from the substantially circular cross section number / total cross section number × 100.

  A single yarn having a substantially circular cross section can be easily obtained, for example, by making the discharge base into a perfect circle, and by changing the discharge base, it has an elliptical shape and a flat circular shape in addition to a single yarn having a perfect circular cross section. A single yarn can be easily obtained.

  The present inventors have studied the relationship between the cross-sectional shape of the single yarn constituting the fabric and the light transmittance, and when the fibers constituting the fabric are multifilaments, the light transmittance is dependent on how the single yarns are arranged. I found that it was greatly affected. That is, the fabric needs to sufficiently introduce light from the light source into the optical sheet. However, when the cross-sectional shape of the single filament of the multifilament fiber constituting the fabric is a substantially circular cross-section, the side surface of the single yarn is curved. It is difficult to arrange single yarns without gaps. That is, a gap is easily formed between the single yarns. Therefore, when light passes through the fabric, there is not only light that passes through the inside of the single yarn but also light that passes through the gaps between the single yarns, and the amount of light that passes through the entire fabric can be maintained large. On the other hand, when the cross section is a polygonal cross section such as a triangle or a quadrangle, adjacent single yarns are arranged so that the sides of the polygon are parallel to each other, so that the space between the single yarns is filled without any gaps. Arranged. As a result, when light passes through the fabric, the light tends to pass through the single yarn, so that the amount of light passing through the fabric tends to be smaller than that of a substantially circular cross section.

On the other hand, when considering the unevenness of brightness, if the cross section of the single yarn is substantially circular, a brightness difference between the light passing through the gap between the single yarn and the light passing through the single yarn will occur. There is a tendency to become large. The smaller the unevenness of brightness, the more uniform the LCD screen will appear, but the greater the unevenness of brightness, the greater the difference between the bright and dark areas, and the unevenness of the LCD screen will become uneven. This is not preferable. Therefore, in the present invention, it is important to include light scattering particles in a single yarn having a substantially circular cross section in order to reduce brightness spots by increasing light scattering and increasing surface reflection. As a result, the light passing through the inside of the single yarn is scattered and the probability of passing through the surrounding single yarn is increased, and the light scattering effect on the surface portion of the single yarn is also increased, so that the luminance unevenness is, for example, 50 to 350 cd / m ² . It can be suppressed within the range.

  In the support of the present invention, substantially all the single yarns constituting the fabric, that is, 80 to 100%, preferably 85 to 100%, more preferably 90 to 100%, have a substantially circular cross section. It is necessary. If it is less than 80%, the scattered light other than the single yarn having a substantially circular cross section becomes large, causing a decrease in the amount of transmitted light, and the fiber gap is easily clogged, and the amount of transmitted light is also decreased here.

  Furthermore, in order to increase the scattered light of the substantially circular cross-sectional yarn, the constituent single yarn needs to contain light scattering particles therein. Examples of the light scattering particles include titanium oxide and calcium carbonate, and ceramics such as alumina and zirconia.

  When light scattering particles are contained in a single yarn as described above, light is scattered inside the single yarn or on the surface of the single yarn, and uneven brightness is improved as a whole fabric. Proceeding in the opposite direction to the screen, the screen cannot be used effectively for display, and as a result, the amount of transmitted light tends to decrease. Therefore, in order to obtain a fabric excellent in light transmittance, the content of light scattering particles is preferably in the range of 0.001 to 0.3 wt% per single yarn weight. That is, when the amount is less than 0.001 wt%, the effect of light scattering particles is not exhibited. Conversely, when the amount exceeds 0.3 wt%, the amount of transmitted light tends to decrease because the amount of scattered light increases. From this point of view, the range is more preferably 0.01 to 0.2 wt%.

  Thus, since the single yarn of the fibers constituting the fabric contains the light scattering particles, it is possible to minimize the decrease in the total light transmission amount when used for the backlight and to improve the luminance unevenness.

  For example, in the case of titanium oxide, the light scattering particle is obtained by melting 6 g of a sample into a plate shape, and obtaining the amount of titanium element in the polymer with a fluorescent X-ray elemental analyzer (manufactured by Horiba, Ltd., MESA-500W type). The content is determined from the measured value. For other particles, the particle content can be calculated from the amount of elements such as Ca, Al, and Zr.

  The number of single yarns of the fibers constituting the fabric may be one monofilament or two or more multifilaments. Of course, the multifilament is preferable because the screen can be made more uniform.

  The fibers constituting the fabric of the present invention preferably have a total fineness of 5 to 450 dtex. By setting the total fineness within this range, there is little generation of fuzz due to fiber damage due to the weaving and knitting process, and the texture of the finished knitted fabric and the amount of transmitted light from the joint are reduced.

  The total fineness and single yarn fineness are in accordance with JIS-L1096 (1999). Three test pieces of 20 cm × 20 cm are taken from the sample, and 25 pieces of warp and weft yarns are unwound from each test piece, and the mass is measured. The apparent fineness is calculated by the following formula, and the average value of the warp yarn and the weft yarn is calculated three times to obtain the total fineness. Further, a value obtained by dividing the number of warp yarns and weft yarns by one filament is defined as a single yarn fineness.

T = (0.2 × W) × 10
Here, T is the total fineness (dtex) of the yarn, and W is the mass (mg) of 25 samples.

  The fibers constituting the fabric as described above may be manufactured by any method. For example, in the case of a fiber containing titanium oxide with a substantially circular cross section, it can be manufactured as follows. Using dimethyl terephthalic acid, ethylene glycol, and tetrabutyl titanate as a catalyst, after performing a transesterification reaction while distilling methanol at 140 ° C. to 230 ° C., further to an ethylene glycol slurry of titanium oxide particles For example, 0.1% by weight is added, and further, polymerization is carried out for 3 hours under a constant temperature of 285 ° C. to obtain a polyethylene terephthalate polymer having an intrinsic viscosity [η] of 0.65. This polymer is melted at 290 ° C. using a known spinning machine, and weighed with a lightweight pump, discharged from a die having a circular discharge hole diameter of 0.23 mm, a discharge hole length of 0.3 mm, and a discharge hole number of 36 H, and converged while cooling. In order to improve the properties, an oil agent is applied and the undrawn yarn is wound up at 1800 m / min. This undrawn yarn is drawn 3.2 times using a drawing machine having a first hot roll of 90 ° C. and a second hot roll of 130 ° C., and a drawn yarn containing titanium oxide in a substantially circular cross section with a total fineness of 84 dtex is obtained. can get. The fabric may be obtained by weaving the yarn thus obtained as warp and weft.

  The configuration of the fabric may be any configuration such as a woven fabric or a knitted fabric, but a woven fabric having good dimensional stability during handling is preferable. If the dimensional stability is poor, the fabric itself is deformed and stretched and contracted when it is fixed by stretching or the like. Therefore, the stretched portion has a small amount of fiber and increases the amount of transmitted light, while the contracted portion increases the amount of fiber and decreases the amount of transmitted light, resulting in luminance unevenness. In addition, when the optical sheet is laminated on the support, the support itself stretches due to the weight of the optical sheet. If sagging occurs, the sagging part becomes closer to the light source, making it brighter than other parts. Brightness unevenness occurs on the backlight screen. Therefore, a woven fabric having good dimensional stability is preferable.

  The weaving structure in the case of a woven fabric is not particularly limited, and any structure such as a plain weave, a twill weave, a satin weave may be used.

When the support is composed of a woven fabric, the cover factor of the woven fabric is preferably in the range of 1200 to 2500. Here, the cover factor is a factor calculated by the following equation, and indicates the magnitude of the weave density of the fibers constituting the fabric.
Cover factor =
Warp yarn density (main / 2.54 cm) x (warp yarn fineness (dtex)) ^1/2
+ Weft density (main / 2.54 cm) × (Weft fineness (dtex)) ^1/2
In the case of the support of the present invention, if the cover factor is smaller than 1200, the amount of fibers constituting the fabric is too small, so that the diffusion of light in the fabric becomes small and the luminance unevenness becomes too large. On the other hand, if the cover factor is greater than 2500, the amount of fibers constituting the fabric is too large, and light cannot be sufficiently transmitted, sufficient luminance cannot be obtained, and the display screen tends to be dark. Therefore, the cover factor is preferably in the range of 1300 to 2200, particularly preferably 1500 to 2000.

  The support of the present invention is preferably subjected to heat treatment in order to reduce dimensional deformation due to tension when it is stretched and fixed, in order to suppress dimensional changes, and heat treatment is performed. Specifically, a load of 4.9 N / 5 cm is applied, and the elongation after 24 hours (hereinafter referred to as creep) is set to be 10% or less in both the longitudinal and lateral directions of the fabric. preferable. Since the support is used for a long time with the weight of the fabric and the weight of the optical sheet added, if the creep is large, the support is gradually extended, resulting in sagging and uneven brightness as described above. Therefore, the creep is preferably 10% or less. More preferably, it is 5% or less, More preferably, it is 3% or less.

  The creep measurement method is as follows. Cut the fabric into 30 cm long and 5 cm wide test pieces (n = 3 each in the vertical and horizontal directions), hold the test piece at a grip interval of 20 cm, and apply a tension of 4.9 N / 5 cm almost uniformly in the width direction. The fabric is suspended so that the length direction is vertical and kept at room temperature (about 25 ° C.) for 24 hours. After 24 hours, the grip interval (L (cm)) is measured, the elongation is calculated by the following formula, and the average value of n = 3 for each of the vertical and horizontal is calculated.

Elongation rate (%) = (L (cm) −20 (cm)) / 20 (cm) × 100
Further, the support is sometimes exposed to ultraviolet rays contained in the light source while the light source of the display is lit, and may turn yellow and deteriorate in strength. When the support turns yellow, the color tone of light transmitted through the yellowed support also changes, and the color tone of the screen displayed on the display also changes. Therefore, it is preferable that the support of the present invention is a fabric that has been subjected to ultraviolet resistance treatment.

  Ultraviolet resistant treatment is treatment using a light stabilizer such as an ultraviolet absorber. The light stabilizer is any one of (1) shielding and absorption of ultraviolet rays, (2) non-radical decomposition of hydroperoxide, (3) quenching of excited compounds, (4) trapping of trace heavy metals, and (5) trapping of radicals. It has one or more functions. Specific examples of the light stabilizer mainly include triazine compounds, benzotriazole compounds, benzophenone compounds, dibenzophenone compounds, salicylate compounds, cyanoacrylate compounds, oxanilide compounds, formamidine compounds, and the like. Ultraviolet absorbers that have ultraviolet shielding and absorption effects, as well as phenolic compounds, phosphorus compounds, organocopper complex compounds, hydrazine compounds, and other antioxidants that mainly have radical scavenging effects, radical scavenging ability and hydroper Hindered amine light stabilizers having oxide resolution and metal ion scavenging ability. The light stabilizer is not particularly limited to these, and can be selected depending on the type of fiber constituting the fabric and the processing method of the light stabilization treatment. Moreover, one type of light stabilizer may be used, or two or more types may be used in combination.

  As a method of applying the light stabilizer, a method of applying to the surface of the fiber such as a spray method, a coating method, or a printing method may be used, or a method of diffusing inside the fabric or fiber may be used. As a method of diffusing inside the fabric or fiber, a dyeing method in a bath where the fabric or fiber is immersed in an aqueous solution containing a light stabilizer and heating, or a fabric or fiber immersed in an aqueous solution containing a light stabilizer, mangle, etc. Then, a pad-cure method or the like in which dry heat treatment is performed after the amount of adhesion is reduced to a predetermined amount can be employed. The light stabilizer can be applied by either the method of forming the fabric after applying it to the fiber or the method of applying the light stabilizer after forming the fabric, but the latter has higher processing stability, This is preferable because the cost can be reduced.

  When the light stabilizer is diffused into the fabric or fiber, the amount of the light stabilizer applied is 0.1 to 5.0% by weight, more preferably 0.5 to 3.0% by weight, based on the weight of the fabric. Good. If the amount is less than 0.1% by weight, the intended UV resistance may not be exhibited. If the amount exceeds 5% by weight, the strength of the fiber may decrease or the cost may increase. .

  In the case of a method of applying a light stabilizer to the fiber surface, such as a spray method, a coating method, or a printing method, the adhesion amount of an ultraviolet absorber or the like is 0.1 to 10.0% by weight, more preferably based on the weight of the fabric. Is 0.5 to 8.0% by weight, more preferably 0.5 to 5.0% by weight. If the amount is less than 0.1% by weight, the target UV resistance may not be achieved as in the case of exhaustion. If the amount exceeds 10.0% by weight, the cost increases or the attached light stability is increased. In some cases, light transmission is hindered by the agent, resulting in a decrease in luminance.

  In the present invention, the fabric has a bending resistance measured in accordance with JIS-L1096 (1999) 8.19 bending resistance A method (45 degree cantilever method) of 100 mm or less in both the vertical and horizontal directions. Is preferred. This is because if the bending resistance exceeds 100 mm, an excessive working tension is required to maintain the surface smoothness during fabric stretching described later. The bending resistance is more preferably 70 mm or less, and further preferably 50 mm or less.

  Specifically, the bending resistance is obtained as follows. First, 5 pieces of 2cm x 15cm test pieces are taken from the sample in each of the vertical and horizontal directions, and the short side of the test piece is scaled on a smooth horizontal surface with a 45 ° slope at one end. Put together. Next, the test piece is gently slid in the direction of the slope, and when the center point of one end of the test piece is in contact with the slope, the position of the other end is read with a scale. The bending resistance is indicated by the length (mm) that the specimen has moved. In the present invention, it is obtained by measuring the front and back of each of the five sheets and calculating the average values in the vertical and horizontal directions.

  In the present invention, the fabric preferably has a tensile strength of 100 N / 5 cm or more in order to prevent the fabric itself from being damaged when stretched and fixed. When supporting the optical sheet, it is considered that a tension of, for example, 50 N / 5 cm is sufficient. Therefore, when the tensile strength is 100 N / 5 cm or more, problems such as breaking of the fabric at the time of stretching and the like do not occur, leading to process stabilization.

  The tensile strength is measured according to the labeled strip method of JIS-L1096 (1999) -8.12.1 A method (strip method). That is, for each of the vertical direction and the horizontal direction, three test pieces were sampled, the thread was removed from both sides of the width to make a width of 50 mm, and a constant speed tension type tester was used. The breaking strength when tested at min is measured, the average value is calculated for each of the vertical direction and the horizontal direction, and this is taken as the tensile strength in the present invention.

Furthermore, in the present invention, the weight of the fabric is preferably 10 g / m ² or more and 300 g / m ² or less in consideration of handleability and light transmittance in the work process. At this time, the weight is calculated by cutting three samples into 20 cm square, measuring the weight, and calculating the average value (m (g)) of the three sheets. Using the value, the weight per m ² (M (g / m ² )) is calculated by the following formula.

M (g / m ² ) = m (g) / (0.2 (m) × 0.2 (m))
If the fabric weight is less than 10 g / m ² , the lightness is excellent, but the rigidity of the fabric is apt to be lost and the handleability is deteriorated because it is too soft. On the other hand, if it exceeds 300 g / m ² , the light transmission property is deteriorated.

  Subsequently, the optical sheet support of the present invention preferably has a member for stretching and fixing the fabric in addition to the fabric as described above. As a result, the fabric can be easily stretched and fixed on the display, and the optical sheet can be easily supported by the tension due to the stretching and fixing.

  The method for stretching and fixing the optical sheet support is not particularly limited, and examples thereof include the following method using a frame.

  (1) The frame includes at least a pair of recesses and projections, one of which is fixed to the fabric, and the fabric is fixed by fitting the recesses and the projections. That is, for example, a fabric fixed to a frame having a convex portion and a housing having a concave portion are prepared, and the concave portion and the convex portion are fitted to fix and stretch the fabric.

  (2) The frame includes at least a pair of concave portions and convex portions, and the fabric is sandwiched and fixed between the concave portions and the convex portions. That is, for example, a method of preparing a frame body having a convex portion and a housing having a concave portion, and holding the fabric between the concave portion and the convex portion to stretch and fix.

  (3) A method in which the fabric is stretched and fixed to the frame with an adhesive and / or an adhesive tape interposed.

  (4) A method in which the fabric is sewn and fixed to the casing.

  (5) A method in which an elastic body portion is provided on the frame and the fabric is stretched and fixed by this elastic force.

  (6) A method in which the fabric is stretched and fixed on the frame by a weight.

  At this time, the frame may be originally provided as a member of the display, or may be handled as a separate member.

  The stretching tension at the time of stretching and fixing is preferably 10 N / 5 cm or more and 100 N / 5 cm or less. That is, it is preferable to stretch and fix while applying a force of 10 N or more and 100 N or less per 5 cm width of the fabric. If it is less than 10 N / 5 cm, sagging tends to occur, and if it exceeds 100 N / 5 cm, the fabric stretches, which is not preferable. The tension at the time of stretching can be applied by, for example, sandwiching the end portion of the fabric with a flat plate or the like so as to apply a uniform force, and pulling while measuring the tension with a spring gauge.

  Further, as a criterion for determining whether or not the appropriate tension is appropriate, the amount of deflection at the center of the light emitting surface when an optical sheet such as a prism sheet or a polarization separation sheet is placed is raised. The amount of deflection when the optical sheet is placed is preferably 10 mm or less. If the amount of deflection exceeds 10 mm, a difference occurs in the amount of light between the central portion and the end portion of the light emitting surface, and light unevenness tends to occur, which is not preferable.

  According to the support of the present invention described above, since the thickness of the support itself can be reduced, the optical sheet can be supported at a position closer to the light source, and the light emitted from the light source can be transmitted in a stronger state, and the display screen Can be brightened. Moreover, since the thickness is thin, it is excellent in compactness, light and excellent in impact resistance, and it is possible to prevent problems such as cracking and cracking during transportation and display assembly process. As a result, it is possible to significantly reduce costs. And since 80 to 100% of the single yarn of the fibers constituting the fabric contains light scattering particles in the fiber and has a substantially circular cross-sectional shape, the amount of light transmitted through the support is increased and the brightness is increased. Brightness unevenness can also be suppressed.

  Next, preferred configurations in which the support of the present invention is applied as a backlight for a liquid crystal display are illustrated in FIGS. 1 and 2, but the present invention is not limited to these configurations.

  FIG. 1 is a cross-sectional view schematically showing a configuration of a backlight when the support of the present invention is incorporated in a sidelight type backlight of a liquid crystal display. In FIG. 1, the sidelight-type backlight includes a light guide plate 3 obtained by processing a transparent acrylic plate, one or a plurality of linear fluorescent tubes (light sources) 5 disposed on the side surface, and a bottom surface of the light guide plate 3. Reflective sheet 4 disposed on the side, support 2 of the present invention disposed on the surface side of light guide plate 3, and brightness enhancement sheets such as a prism sheet and a polarization separation sheet disposed further above support 2 (Optical sheet) 1.

  FIG. 2 is a diagram schematically showing a configuration of a backlight when the support 2 of the present invention is incorporated in a direct type backlight of a liquid crystal display. In FIG. 2, the direct type backlight has a plurality of linear fluorescent tubes 5 arranged inside a casing 6 in which a reflection sheet 4 is spread, and the support 2 of the present invention is arranged above the fluorescent tubes 5. Further, a brightness enhancement sheet (optical sheet) 1 such as a prism sheet or a polarization separation sheet is disposed on the support 2. And in this embodiment, in order to prevent the support body 2 from bending greatly, the support pillar 7 is installed.

  A liquid crystal display is configured by disposing a liquid crystal cell above the optical sheet of the backlight shown in FIGS.

  Moreover, the support body 2 of the present invention described above can be preferably used for a rear projection display.

  The rear projection display is a display that displays an image by enlarging and projecting an image generated by a CRT, a liquid crystal panel, or the like onto a rear projection screen using a projection lens. The screen used here bears the function of appropriately distributing projection light and enabling good image recognition. As the screen, for example, it is possible to use a diffuser plate with isotropic diffusivity mixed with diffusing particles. However, since the incident light is divergently incident, the periphery of the screen is directed outward. When observed from the front side of the screen, the brightness unevenness on the screen becomes noticeable, such as bright and dark at the center and dark when viewed from an oblique direction and darker near and brighter. In order to eliminate such luminance unevenness, it is common to arrange a Fresnel lens sheet on the projection lens side, but in order to support an optical sheet such as this Fresnel lens sheet, the support of the present invention is used. Can be used.

  The Fresnel lens sheet functions to convert the projection light divergingly incident on the screen from the projection lens into parallel light substantially perpendicular to the screen. Therefore, if the direction of light in each part of the screen is changed to a direction perpendicular to the screen surface and then diffused, almost uniform brightness can be realized over the entire screen regardless of the direction of observation. it can. And if it laminates | stacks on this Fresnel lens sheet with the support body of this invention, it can diffuse not only the Fresnel lens sheet but the light which became parallel light through it.

  Conventionally, the lenticular lens sheet generally plays a role of supporting the Fresnel lens sheet and diffusing light from the sheet. The lenticular lens sheet is a sheet having anisotropic diffusivity that diffuses parallel light incident with image light in the horizontal direction and expands the viewing angle. However, the lenticular lens sheet usually has a thickness of about 2 to 3 mm and has the above-described problems. Therefore, in the rear projection type display, if the support of the present invention is used instead of the lenticular lens sheet, the same effect as the above-described liquid crystal display can be obtained.

  Hereinafter, although an example is given and the present invention is explained, the present invention is not necessarily limited to this. The measurement methods for various characteristics used in this example and the criteria for comprehensive evaluation were as follows.

(Characteristic measurement method)
A. Total light transmittance Measured using a fully automatic direct reading haze computer HGM-2DP (for C light) (manufactured by Suga Test Instruments Co., Ltd.) according to method A of JIS-K-7105 (established 1981).

The outline of the measurement procedure is as follows. The measuring device is an integrating sphere type light transmittance measurement that satisfies the optical conditions described in JIS-K-7105, paragraph 5.5.2 (1) (light transmittance and total light reflectance measurement method A device). Measure using the instrument.
(1) Cut a fabric that has been conditioned for 48 hours or more in a dark place at a temperature of 23 ± 2 ° C. and a relative humidity of 50 ± 5% in advance into 50 × 50 mm test pieces (the number of test pieces is 3). .
(2) A standard white plate is attached, and the amount of incident light is adjusted by adjusting the support of the apparatus to 100.
(3) With the standard white plate attached, the test piece is attached and the total light transmitted light amount (Tt) is measured.
(4) The total amount of light transmitted through the three test pieces is measured, and the average value of these is obtained (the first decimal place is rounded off). This average value is defined as the total light transmittance of the fabric in the present invention.

B. Luminance unevenness of optical sheet support First, remove the diffusion plate installed on the fluorescent tube of the direct type backlight, and in the case of fabric, place a transparent plastic plate with the same thickness as the diffusion plate, on it A cloth was placed, and in the case of a milky white plate, a transparent plastic plate was not placed, and the fluorescent tube was lit for 60 minutes to stabilize the light source. After that, using the luminance measurement device EYSCALE-3 (manufactured by I-System Co., Ltd.) from the measurement sample side, the attached CCD camera is placed at a point 90 cm from the center of the light emitting surface of the direct type backlight, It installed so that it might become the front with respect to a surface, and the brightness | luminance (cd / m < ² >) was measured. The measurement locations were two locations (L _max ) just above the two fluorescent tubes on the left and right of the center point, and three luminance locations (L _min ) between the two measured fluorescent tubes and the adjacent fluorescent tubes. . The brightness unevenness is calculated from the following formula, and the brightness unevenness is better as the value is smaller.

Brightness unevenness (cd / m ² ) = (average value of L _max ) − (average value of L _min )
C. Single yarn cross-sectional shape The single yarn cross-sectional shape was observed with a parallax scanning microscope.

D. Fabric thickness Measured using a thickness gauge (pressing pressure 0.98 N / cm ² ).

E. Weight of Fabric Three samples were cut into 20 cm square, the weight was measured, and the average value (m (g)) of the three sheets was calculated. Using this value, the weight per m ² (M (g / m ² )) was calculated by the following formula.

M (g / m ² ) = m (g) / (0.2 (m) × 0.2 (m))
F. Tensile strength JIS-L1096 (1999)-8.12.1 In accordance with the labeled strip method of the A method (strip method), three specimens were sampled in each of the vertical and horizontal directions, from both sides of the width. Measure the breaking strength when testing with a constant speed tension type tester at a gripping interval of 150 mm and a pulling speed of 200 mm / min with a constant speed tension type tester by removing the yarn and calculating an average value in each of the vertical and horizontal directions. did.

G. Bending softness Bending softness was measured according to JIS-L1096 (1999) 8.19 Bending softness A method (45 degree cantilever method). That is, first, five 2 cm x 15 cm test pieces are sampled from the sample in each of the vertical and horizontal directions, and the short side of the test piece is scaled on a smooth horizontal surface with a 45-degree slope at one end. I put it to match. Next, the test piece was slid gently in the direction of the slope, and when the central point of one end of the test piece was in contact with the slope, the position of the other end was read with a scale. The bending resistance was indicated by the length (mm) that the test piece moved, and the front and back of each of the five pieces were measured, and the average value in each of the vertical and horizontal directions was calculated.

H. The amount of deflection at the center of the light emitting surface in the backlight The amount of deflection at the center of the light emitting surface was measured by passing a non-deflable metal rod directly above the center and measuring the gap between the lower surface of the metal rod and the optical film with a caliper.

I. Visual evaluation of backlight luminance and luminance unevenness Visual evaluation was performed by 10 persons at a position 1 m from the light emitting surface. The most frequent evaluation was adopted by observing uneven brightness. In the case of the same number of people, a higher evaluation was adopted.

J. et al. Comprehensive evaluation In Table 1 to be described later, the comprehensive evaluation was based on the brightness unevenness of the support and the quality of the total light transmittance as judgment criteria, and the three-level display based on the following criteria.
A: The brightness unevenness of the support is 200 cd / m ² or less, and the total light transmittance is 50% or more.
Δ: The luminance unevenness of the support is 250 cd / m ² or less, and the total light transmittance is 45% or more.
X: The luminance unevenness of the support is 300 cd / m ² or less, and the total light transmittance is 40% or more.

<Example 1>
The fabric produced in the following configuration was subjected to UV resistance treatment, and various properties were evaluated as described above. Further, as described below, the supportability of the optical sheet and the deflection, luminance, and luminance unevenness of the central portion of the light emitting surface in the backlight were evaluated.

  The evaluation results are shown in Table 1.

  The optical sheet could be favorably supported, sufficient luminance was obtained as a backlight, and there was no luminance unevenness.

(Fabric composition)
1. Yarns used: warp, weft 84 dtex-36 filament, 100% polyester filament yarn (100% of the component single yarn has a substantially circular cross section)
2. Single yarn cross-sectional shape: substantially circular 3. Titanium oxide amount: 0.2 wt% per single yarn weight (100% of the constituent single yarn contains titanium oxide)
4). 4. Weaving organization: Plain weave Weave density: Vertical weave density 110 pieces / inch (2.54 cm), Horizontal weave density 85 pieces / inch (2.54 cm)
(UV resistant)
An ultraviolet absorption treatment solution containing a triazine-based ultraviolet absorber (trade name: CIBAFAST P, manufactured by Ciba Specialty Chemicals Co., Ltd.) with 2% by weight of the fabric and 1.0 g / L of ammonium sulfate, and a fabric having the above-described structure In the bath, the volume ratio was fabric: aqueous solution = 1: 20. The treatment conditions were as follows: dyeing in a bath at 130 ° C. for 60 minutes, followed by washing with hot water at 60 ° C. for 10 minutes and rinsing with running water for 5 minutes. Then, it dried at 120 ° C. for 3 minutes. The adhesion amount of the ultraviolet absorber was 0.8% by weight.

(Supportability of optical sheet and deflection at the center of the light emitting surface of the backlight, luminance, luminance unevenness)
The 32-inch direct type backlight shown in FIG. 2 was constructed. The fabric was stretched without sagging or wrinkles and fixed to the four sides of the housing with double-sided tape. Subsequently, a 32-inch prism sheet and a polarization separation sheet were placed on the support as optical sheets, and the amount of deflection at the center of the light emitting surface was measured.

  Furthermore, the fluorescent lamp was turned on, and the luminance and luminance unevenness of the backlight were visually evaluated.

<Comparative Example 1>
Add 3 parts by weight of silicone resin particles (Tospearl 120, manufactured by GE Toshiba Silicone Co., Ltd.) with an average particle diameter of 2 μm to 100 parts by weight of methacrylic resin, melt and extrude using an extruder, and a 2 mm thick milk plate The various characteristics described above were evaluated for the milky white plate. Further, as described below, the supportability of the optical sheet and the deflection, luminance, and luminance unevenness of the central portion of the light emitting surface in the backlight were evaluated.

  The evaluation results are shown in Table 1.

  Although the optical sheet could be supported well, the milky white plate was heavy and the workability was poor. Moreover, sufficient brightness as a backlight could not be obtained. In this comparative example, the total light transmittance of the milky white plate is 50% even though the luminance evaluation result as the backlight is D. The light that the milky white plate is incident from an oblique direction as compared with the fabric. It is considered that not only the straight light but also the light incident from an oblique direction is the measurement object.

(Supportability of optical sheet and deflection at the center of the light emitting surface of the backlight, luminance, luminance unevenness)
In constructing the 32-inch backlight shown in FIG. 2, the evaluation was performed in the same manner as in Example 1 except that a milky white plate was installed instead of the support.

<Comparative example 2>
The fabric produced as described below was subjected to UV resistance treatment, and the above-mentioned various characteristics were evaluated. Further, as described below, the supportability of the optical sheet and the deflection, luminance, and luminance unevenness of the central portion of the light emitting surface in the backlight were evaluated.

  The evaluation results are shown in Table 1.

  Although the optical sheet could be supported well, the luminance unevenness was large as a backlight.

(Fabric composition)
1. Yarn used: warp, weft 84 dtex-36 filament, 100% polyester filament yarn Single yarn cross-sectional shape: substantially circular cross section (100% of the constituent single yarn is substantially circular cross section)
3. 3. Titanium oxide amount: None 4. Weaving organization: Plain weave Weave density: Vertical weave density 110 pieces / inch (2.54 cm), Horizontal weave density 85 pieces / inch (2.54 cm)
(UV resistant)
An ultraviolet absorption treatment solution containing a triazine-based ultraviolet absorber (trade name: CIBAFAST P, manufactured by Ciba Specialty Chemicals Co., Ltd.) with 2% by weight of the fabric and 1.0 g / L of ammonium sulfate, and a fabric having the above-described structure In the bath, the volume ratio was fabric: aqueous solution = 1: 20. The treatment conditions were as follows: dyeing in a bath at 130 ° C. for 60 minutes, followed by washing with hot water at 60 ° C. for 10 minutes and rinsing with running water for 5 minutes. Then, it dried at 120 ° C. for 3 minutes. The adhesion amount of the ultraviolet absorber was 0.8% by weight.

(Supportability of optical sheet and deflection at the center of the light emitting surface of the backlight, luminance, luminance unevenness)
Evaluation was performed in the same manner as in Example 1.

<Comparative Example 3>
The fabric produced as described below was subjected to UV resistance treatment, and the above-mentioned various characteristics were evaluated. Further, as described below, the supportability of the optical sheet and the deflection, luminance, and luminance unevenness of the central portion of the light emitting surface in the backlight were evaluated.

  The evaluation results are shown in Table 1.

  Although the optical sheet could be supported satisfactorily, sufficient brightness as a backlight could not be obtained.

(Fabric composition)
1. Yarn used: warp, weft 84 dtex-36 filament, polyethylene terephthalate 100% filament yarn Single yarn cross-sectional shape: Triangle (100% of the constituent single yarn is triangular cross-section)
3. Titanium oxide amount: 0.2 wt% per single yarn weight (100% of the constituent single yarn contains titanium oxide)
4). 4. Weaving organization: Plain weave Weave density: Vertical weave density 110 pieces / inch (2.54 cm), Horizontal weave density 85 pieces / inch (2.54 cm)
(UV resistant)
An ultraviolet absorption treatment solution containing a triazine-based ultraviolet absorber (trade name: CIBAFAST P, manufactured by Ciba Specialty Chemicals Co., Ltd.) with 2% by weight of the fabric and 1.0 g / L of ammonium sulfate, and a fabric having the above-described structure In the bath, the volume ratio was fabric: aqueous solution = 1: 20. The treatment conditions were as follows: dyeing in a bath at 130 ° C. for 60 minutes, followed by washing with hot water at 60 ° C. for 10 minutes and rinsing with running water for 5 minutes. Then, it dried at 120 ° C. for 3 minutes. The adhesion amount of the ultraviolet absorber was 0.8% by weight.

(Supportability of optical sheet and deflection at the center of the light emitting surface of the backlight, luminance, luminance unevenness)
Evaluation was performed in the same manner as in Example 1.

<Examples 2-3>
The fabric produced as described below was subjected to UV resistance treatment, and the above-mentioned various characteristics were evaluated. Further, as described below, the supportability of the optical sheet and the deflection, luminance, and luminance unevenness of the central portion of the light emitting surface in the backlight were evaluated.

  The evaluation results are shown in Table 1.

  In any case, the optical sheet could be favorably supported, sufficient luminance was obtained as a backlight, and there was no luminance unevenness.

(Fabric composition)
1. Yarn used: Changed as described in Table 1.
2. Single yarn cross-sectional shape: changed as described in Table 1 (100% of the constituent single yarn is a substantially circular cross-section).
3. Titanium oxide amount: changed as described in Table 1 (100% of the constituent single yarn contains titanium oxide).
4). 4. Weaving organization: Plain weave Weave density: changed as described in Table 1.

(UV resistant)
An ultraviolet absorption treatment solution containing a triazine-based ultraviolet absorber (trade name: CIBAFAST P, manufactured by Ciba Specialty Chemicals Co., Ltd.) with 2% by weight of the fabric and 1.0 g / L of ammonium sulfate, and a fabric having the above-described structure In the bath, the volume ratio was fabric: aqueous solution = 1: 20. The treatment conditions were as follows: dyeing in a bath at 130 ° C. for 60 minutes, followed by washing with hot water at 60 ° C. for 10 minutes and rinsing with running water for 5 minutes. Then, it dried at 120 ° C. for 3 minutes. The adhesion amount of the ultraviolet absorber was 0.9% by weight.

(Supportability of optical sheet and deflection at the center of the light emitting surface of the backlight, luminance, luminance unevenness)
Evaluation was performed in the same manner as in Example 1.

<Example 4, comparative example 4>
Except for changing the amount of titanium oxide, the fabric produced in the same manner as described below was subjected to UV resistance treatment, and the above various properties were evaluated. Further, as described below, the supportability of the optical sheet and the deflection, luminance, and luminance unevenness of the central portion of the light emitting surface in the backlight were evaluated.

  The evaluation results are shown in Table 1.

  In either case, the optical sheet could be favorably supported, but Comparative Example 4 had large luminance unevenness as a backlight.

(Fabric composition)
1. Thread used: warp, weft 20 dtex-18 filament, polyethylene terephthalate 100% filament yarn Single yarn cross-sectional shape: substantially circular (both 100% of the constituent single yarns are substantially circular in cross section)
3. Titanium oxide amount: changed as described in Table 1 (Example 4 includes 100% of the constituent single yarn containing titanium oxide).
4). 4. Weaving organization: Plain weave Weave density: Vertical weave density 130 / inch (2.54cm), Horizontal weave density 110 / inch (2.54cm)
(UV resistant)
An ultraviolet absorption treatment solution containing a triazine-based ultraviolet absorber (trade name: CIBAFAST P, manufactured by Ciba Specialty Chemicals Co., Ltd.) with 2% by weight of the fabric and 1.0 g / L of ammonium sulfate, and a fabric having the above-described structure In the bath, the volume ratio was fabric: aqueous solution = 1: 20. The treatment conditions were as follows: dyeing in a bath at 130 ° C. for 60 minutes, followed by washing with hot water at 60 ° C. for 10 minutes and rinsing with running water for 5 minutes. Then, it dried at 120 ° C. for 3 minutes. The adhesion amount of the ultraviolet absorber was 0.9% by weight.

(Supportability of optical sheet and deflection at the center of the light emitting surface of the backlight, luminance, luminance unevenness)
Evaluation was performed in the same manner as in Example 1.

<Examples 5-9>
Except for changing the amount of titanium oxide, the fabric produced in the same manner as described below was subjected to UV resistance treatment, and the above various properties were evaluated. Further, as described below, the supportability of the optical sheet and the deflection, luminance, and luminance unevenness of the central portion of the light emitting surface in the backlight were evaluated.

  The evaluation results are shown in Table 2.

  In any case, the optical sheet could be favorably supported, sufficient luminance was obtained as a backlight, and there was no luminance unevenness.

(Fabric composition)
1. Yarns used: warp, weft 84 dtex-36 filament, 100% polyester filament yarn (100% of the component single yarn has a substantially circular cross section)
2. Single yarn cross-sectional shape: substantially circular (both 100% of the constituent single yarns are substantially circular in cross section)
3. Titanium oxide amount: changed as described in Table 2.
4). 4. Weaving organization: Plain weave Weave density: Vertical weave density 110 pieces / inch (2.54 cm), Horizontal weave density 85 pieces / inch (2.54 cm)
(UV resistant)
An ultraviolet absorption treatment solution containing a triazine-based ultraviolet absorber (trade name: CIBAFAST P, manufactured by Ciba Specialty Chemicals Co., Ltd.) with 2% by weight of the fabric and 1.0 g / L of ammonium sulfate, and a fabric having the above-described structure In the bath, the volume ratio was fabric: aqueous solution = 1: 20. The treatment conditions were as follows: dyeing in a bath at 130 ° C. for 60 minutes, followed by washing with hot water at 60 ° C. for 10 minutes and rinsing with running water for 5 minutes. Then, it dried at 120 ° C. for 3 minutes. The adhesion amount of the ultraviolet absorber was 0.9% by weight.

(Supportability of optical sheet and deflection at the center of the light emitting surface of the backlight, luminance, luminance unevenness)
Evaluation was performed in the same manner as in Example 1.

  From Tables 1 and 2, it can be seen that the support of the present invention exhibits an optical performance equal to or higher than that of a conventional resin plate (milky white plate).

It is a schematic cross section of a sidelight type backlight used for a liquid crystal display and having a support according to the present invention. It is a schematic cross section of a direct type backlight used for a liquid crystal display and having a support according to the present invention.

Explanation of symbols

1 Brightness improvement sheet (optical sheet)
2 Optical sheet support 3 Light guide plate 4 Reflective sheet 5 Fluorescent tube 6 Housing 7 Support column

Claims (11)

  A support for an optical sheet mounted on a display, comprising a fabric composed of fibers, wherein 80 to 100% of the single yarn constituting the fibers contains light scattering particles in the fibers, and is substantially circular An optical sheet support having the following cross-sectional shape.   The optical sheet support according to claim 1, wherein the light scattering particles are titanium oxide.   The optical sheet support according to claim 1 or 2, wherein the content of light scattering particles contained in the single yarn is in the range of 0.001 to 0.3 wt% per single yarn weight.   The optical sheet support in any one of Claims 1-3 whose total fineness of the fiber which comprises the said fabric exists in the range of 5-450 dtex.   The optical sheet support according to any one of claims 1 to 4, wherein the fabric is a woven fabric. Luminance unevenness of the fabric is in the range of 50~350cd / ^{m 2,} the optical sheet support according to any one of claims 1 to 5.   The optical sheet support according to any one of claims 1 to 6, wherein the fabric is subjected to ultraviolet resistance treatment.   The optical sheet support according to any one of claims 1 to 7, which is mounted on a backlight of a liquid crystal display.   The backlight for liquid crystal displays provided with the optical sheet support body in any one of Claims 1-8.   A liquid crystal display comprising the liquid crystal display backlight according to claim 9.   A rear projection display comprising the optical sheet support according to claim 1.

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