JP4090283B2 - Reflector and sidelight type backlight device using the same - Google Patents

Description

【００３６】
【表２】

【００３７】
【表３】

【００３８】
【発明の効果】
本発明の反射用基板を用いることで、製造工程、加工工程において、不良となるキズの発生が起こりにくくなり、取り扱い性、生産性の向上が得られる。また、本発明の反射体を組み込んだサイドライト型バックライト装置は、該バックライト装置において、反射体に歪みが発生した場合でも、その歪みによる輝度ムラが生じないため、視認性のよい液晶ディスプレイを提供することができる。また、該反射体は、従来の反射体に比べ高輝度であり、かつ耐久性にも優れるため、長期にわたり、均一で、高輝度な光を得られることから、液晶の表示能力を向上させることができるため、本発明の工業的意義は大きい。
【図面の簡単な説明】
【図１】 本発明に於ける反射シートの一例を示す断面図
【図２】 本発明の面光源装置の一例
【符号の説明】
１０ 反射層
２０ 突起
３０ 高分子フィルム
４０ 冷陰極管
５０ ランプリレフクター
６０ 導光板
７０ 反射シート[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a reflector having high reflectance and high luminance and low luminance unevenness, and further relates to a sidelight type backlight device and a liquid crystal display device applied to a liquid crystal display device using the same.
[0002]
[Prior art]
Liquid crystal displays are widely used mainly for displays of small and medium-sized devices because they are thinner and space-saving than conventional CRT displays and can save energy with less power consumption.
[0003]
A liquid crystal display widely used at present is a transmissive liquid crystal display using a backlight as a light source. The visibility of the display on this liquid crystal display is not only due to the performance of the liquid crystal itself but also due to the performance of the backlight. The backlight method requires the lighter and thinner LCD display in recent years, the brightness uniformity, and the heat from the light source is difficult to transfer to the LCD panel. A sidelight type backlight that uses a light guide plate instead of a direct type that places a reflection plate on it and uses multiple reflections of light from a light source disposed at one end thereof is used as a surface light source.
[0004]
A diffused reflection member made of a white PET film or the like is often disposed under the light guide plate, and uniform luminance can be obtained by diffusing light with this reflector. However, since these irregular reflection members have almost no specular reflection component, there is a problem in that sufficient luminance cannot be obtained although it is uniform as a whole. In addition, when a sheet obtained by vapor-depositing aluminum on a transparent PET film is used, the brightness is improved as compared with white PET, but since there is no diffuse reflection component, a slight distortion of the sheet greatly affects the brightness unevenness, and a beautiful image is obtained. Can't get. In order to solve this problem, a sheet in which a metal is vapor-deposited on a film having a roughened surface has been developed. However, when aluminum is used as a metal to be used, durability is excellent, but not so high luminance can be obtained. Further, when silver having the highest reflectivity in the visible light region is used, sufficient luminance can be obtained, but silver has a problem that durability is poor and it deteriorates quickly and luminance decreases.
[0005]
In order to solve these problems, the present inventors apply particles of a certain size on the polymer film, so that the lower surface of the light guide plate on which the reflector is installed is placed between the light guide plate and the reflector. It was found that the problem can be solved by providing a space as a cushioning material. However, at this time, since the coating layer that is the base of the reflective layer is soft, there is a problem in that the product yield is not increased due to easy damage to the manufacturing process and the processing process.
[0006]
[Problems to be solved by the invention]
The present invention is a high-brightness and highly durable reflector, and in each process until the reflector is incorporated into a sidelight type backlight device, the occurrence of defective scratches is unlikely to occur, and productivity and handling are improved. By supplying an excellent reflector, a sidelight type backlight device that is brighter and more productive than conventional ones is provided.
[0007]
[Means for Solving the Problems]
As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that the coating material on the film serving as the base of the reflector has a hardness higher than that at the time of drying as a method for eliminating the occurrence of scratches on the reflector. It was found that the problem was solved by using things.
[0008]
That is, the present invention
(1) A coating liquid comprising at least a substrate, a concavo-convex layer, and a reflective layer, comprising particles having an average particle diameter of 5 μm to 50 μm and a binder resin having a glass transition temperature of 40 ° C. or higher. The uneven layer formed by applying to the substrate has 2 to 100 protrusions per 1 mm ² with a maximum width of 10 μm to 50 μm and a height of 5 μm to 45 μm ,
The ratio of the dent amount 5 seconds after unloading to the dent amount on the reflector surface when a load of 9.8 mN is applied for 5 seconds with a dynamic microhardness meter is 0.7 or less,
The value in the pencil scratch test of JIS K5400 on the reflective surface is HB or more ,
A reflector having a ratio of diffuse reflectance to total reflectance (diffusivity) of 1% to 50%;
(2) The reflector according to (1) above, wherein the surface of the substrate on which the reflective layer is not formed is subjected to an easy slip treatment ,
(3) The reflector according to either (1) or (2) is provided on the lower surface of a light guide plate that emits light incident from a light source installed on a side surface to the upper surface. Sidelight type backlight device,
(4) The sidelight-type backlight device according to (3), wherein the reflector is disposed so that the reflective layer is on the light guide plate side,
(5) A liquid crystal display device comprising the sidelight-type backlight device according to (4),
About.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail.
What is used for the reflector substrate of the present invention is a physically and chemically stable glass plate, a plate such as a ceramic plate, a sheet-like inorganic material, an organic material such as a polymer sheet or a polymer film, or the like. Used as appropriate. Among these, a polymer film that has a high degree of freedom in shape and that can be applied with a roll-to-roll process is preferable. Examples of the polymer film include polyethylene terephthalate (PET), polyethylene naphthalate, polyesters such as liquid crystal polyester having a liquid crystal structure in a molten state, polycarbonates such as bisphenol A polycarbonate, polyolefins such as polyethylene and polypropylene, cellulose triacetate Examples include cellulose derivatives such as vinyl resins such as polyvinylidene chloride, polyimides, polyamides, polyethersulfone, polysulfone resins, polyarylate resins, and films made of various plastics such as fluorine resins. The glass transition point is not limited to a certain level, and any glass having a smooth surface can be used. Of these, polyethylene terephthalate is preferable.
[0010]
The thickness of the polymer film to be used requires a certain amount of stiffness in the sheet, and it is generally desirable that the thickness is about 100 to 200 μm.
Protrusions formed on the A surface on the polymer film are formed by various methods, and among them, it is preferable to form the protrusions by applying particles whose surface state is relatively easy to adjust. Examples of the particles to be applied include polymer (organic) particles such as acrylic, polystyrene, vinylbenzene, styrene methacrylate, styrene acrylate, and styrene butadiene, silica, alumina, titania, zirconia, lead oxide (lead white), Also used are inorganic fine particles composed of zinc oxide (zinc white), calcium carbonate, barium carbonate, barium sulfate, potassium titanate, sodium silicate, and conductive transparent fine particles such as tin oxide, indium oxide, cadmium oxide, and antimony oxide. However, the present invention is not necessarily limited thereto. Of these, acrylic resin or silica is preferable.
[0011]
In the present invention, it is preferable to use particles having an average particle diameter of 10 μm to 50 μm. The particles are usually applied in a state of being dispersed in a binder resin. The glass transition temperature of the binder resin is preferably 40 ° C. or higher, more preferably 50 ° C. or higher. The binder resin is usually composed of a main agent and a curing agent. As the main agent, for example, acrylic resins such as polymethyl methacrylate, polyacrylonitrile resins, polymethacrylonitrile resins, silicon resins such as polymers obtained from ethyl silicate, fluorine resins, polyester resins, polystyrene resins, Acetate resin, polyether sulfone resin, polycarbonate resin, polyamide resin, polyimide resin, polyolefin resin, polyurethane resin, urea resin, melamine resin, epoxy resin, and mixtures thereof can be mentioned. It is not necessarily limited to these. As the curing agent, melamine resin, isocyanate prepolymer, epoxy resin, alkoxysilane and the like are used. In the present invention, those having a glass transition temperature of 40 ° C. or higher are selected from the main agent and the curing agent. Especially, the combination of an acrylic resin and an isocyanate prepolymer is preferable, and normally it hardens | cures by drying at the temperature of 130 to 180 degreeC for 1 minute-5 minutes after coating. When curing is difficult to proceed, a catalyst can be appropriately added and adjusted.
[0012]
Usually, a solvent is used to disperse the particles in the binder resin. As the solvent, toluene, methyl ethyl ketone, ethyl acetate, isopropyl alcohol and the like are preferably used. These are solvents generally used at the time of the coating operation, and any other solvent that does not affect the base polymer film or particles can be used without any problem. In addition, additives such as wetting agents, thickeners, dispersants and antifoaming agents may be added as necessary.
[0013]
The compounding ratio of the particles is preferably 0.1 wt% or more and 10 wt% or less with respect to the binder resin. If the blending ratio is less than 0.1 wt%, the necessary diffusion characteristics cannot be obtained, which is not preferable. If it is too large for 10 wt%, the light diffusibility becomes too strong, which may not be preferable.
[0014]
The coating solution is preferably prepared so that the solid content is 5 wt% or more and 50 wt% or less. If the solid content is less than 5 wt%, the viscosity of the liquid becomes too small, and the particles may not get on the film, and it is not preferable because the desired particle amount cannot be obtained, and the solid content is more than 50 wt%. In this case, the thickness of the coating layer is increased, and the height as the protrusion may not be sufficiently obtained.
[0015]
The coating liquid is preferably applied on the polymer film in a wet state at a coating amount of 10 g / m ² or more and 40 g / m ² . The mixing ratio of the particles is reflected in the particle density on the reflector surface and affects the diffusivity of the reflector. The coating amount is reflected in the thickness of the binder layer on the polymer film, and affects the difference in height from the top of the particles, that is, the size of the spacer when contacting the light guide plate. If the amount of the coating solution is smaller than 10 g / m ^2, the amount of particles contained in the coating solution is insufficient, and the necessary diffusion performance may not be obtained, which is not preferable. On the other hand, if the amount of the coating solution is larger than 40 g / m ² , the particles are buried in the binder resin, and the necessary protrusion height may not be obtained, which is not preferable. That is, by adjusting the compounding amount of the particles and the coating amount of the coating liquid within the above range, 2 to 100 protrusions per 1 mm ² can be obtained on the polymer film. Further, the height of the protrusion from the binder surface to the particle top can be easily measured by a palpation roughness meter, a surface shape measuring device, or the like.
[0016]
As a method of applying a mixed liquid containing the above particles and binder resin to a polymer film, it can be applied over a wide viscosity range, and the coating thickness can be adjusted during running, and the coating thickness can be greatly increased. The roll coater method, the reverse roll coater method, which has the characteristics that it can be changed into a thin film, and the clavia coater method that has the characteristics that the coating thickness is uniform even if it is wide, and the thin film can be coated. The die coating (extrusion) method has features such as high-speed coating, high productivity, uniform coating thickness, and a wide range of coating, and any method can be applied without any particular problem.
The reflector of the present invention can be obtained, for example, by forming a reflective layer on a protrusion produced by the method described above. The reflective layer is preferably a base layer (a), a metal layer (b) mainly composed of silver, and a transparent oxide layer (c) in this order from the polymer film side.
[0017]
In the underlayer (a), gold, copper, nickel, iron, cobalt, tungsten, molybdenum, tantalum, chromium, indium, manganese, titanium, neodymium, palladium, or other metal alone, or an alloy composed of two or more kinds, or Zinc oxide doped with 5% by weight or less of aluminum oxide, zinc oxide doped with 10% by weight or less of gallium, transparent oxide such as indium and tin oxide (ITO) or silicon dioxide is preferably used.
[0018]
For the metal layer (b) mainly composed of silver, silver alone or an alloy such as gold, copper, palladium, neodymium or platinum mainly composed of silver is preferably used. In addition, the purity of these silver and silver-based alloys is preferably 100%, but gold, copper, nickel, iron, cobalt, tungsten, molybdenum, tantalum, chromium to the extent that they do not harm their performance. , Indium, manganese, titanium, palladium and the like may be contained in small amounts as impurities.
[0019]
The transparent oxide layer (c) is made of zinc oxide doped with 5% by weight or less of aluminum oxide, zinc oxide doped with 10% by weight or less of gallium, oxide of indium and tin (ITO), transparent such as silicon dioxide An oxide is preferably used.
[0020]
As a method for forming the metal thin film layer, there are a wet method and a dry method. The wet method is a general term for a plating method, and is a method of forming a film by depositing a metal from a solution. Specific examples include silver mirror reaction. On the other hand, the dry method is a general term for a vacuum film-forming method. Specific examples include a resistance heating vacuum deposition method, an electron beam heating vacuum deposition method, an ion plating method, and an ion beam assisted vacuum deposition method. And sputtering method. In particular, a vacuum film forming method capable of a roll-to-roll method for continuously forming a film is preferably used in the present invention.
[0021]
In the vacuum deposition method, a metal raw material is melted by an electron beam, resistance heating, induction heating or the like to increase the vapor pressure, and is preferably evaporated to the substrate surface at 13.3 mPa (0.1 mTorr) or less. At this time, a gas such as argon may be introduced at 13.3 mPa or more to cause high frequency or direct current glow discharge.
[0022]
As the sputtering method, a DC magnetron sputtering method, an RF magnetron sputtering method, an ion beam sputtering method, an ECR sputtering method, a conventional RF sputtering method, a conventional DC sputtering method, or the like can be used.
In the sputtering method, a metal plate target may be used as a raw material, and helium, neon, argon, krypton, xenon, or the like may be used as a sputtering gas, but argon is preferably used. The purity of the gas is preferably 99% or more, more preferably 99.5% or more. In addition, a vacuum film forming method is preferably used for forming the transparent oxide film. Sputtering is mainly used, and helium, neon, argon, krypton, xenon, or the like is used as the sputtering gas, and in some cases, oxygen gas may be used.
[0023]
The thickness of the thin film formed on the projection is determined in consideration of the light transmittance being less than 1% when the reflector is used.
The thickness of each layer in the reflective layer of the present invention is preferably as follows.
When the metal layer is used, the thickness of the underlayer (a) is preferably 5 nm or more and 50 nm or less, more preferably 5 nm or more and 30 nm or less. When the thickness of the layer is less than 5 nm, a desired barrier effect cannot be obtained, and aggregation may occur in the metal layer (b) mainly composed of silver. Even if the thickness is larger than 50 nm, the effect is not changed. When a transparent oxide is used, the thickness of the layer is preferably 1 nm or more and 20 nm or less, and more preferably 5 or more and 10 nm or less. When the thickness of the layer is less than 1 nm, the desired barrier effect cannot be obtained, and aggregation may occur in the metal layer (b) mainly composed of silver, which is not preferable. Even if it is thicker than 10 nm, the effect does not change.
[0024]
The thickness of the metal layer (b) mainly composed of silver is preferably from 70 to 400 nm, more preferably from 100 to 300 nm, and still more preferably from 150 to 250 nm. If the thickness of such a layer is less than 70 nm, a sufficient reflectance may not be obtained because a sufficient metal layer cannot be formed. Even if the thickness is larger than 400 nm, the effect is not changed.
[0025]
The thickness of the transparent oxide layer (c) is preferably 1 nm or more and 20 nm or less, and more preferably 5 nm or more and 10 nm or less. If the thickness of the layer is less than 1 nm, the desired barrier effect cannot be obtained, and aggregation may occur in the metal layer (b) mainly composed of silver. Even if the thickness is larger than 400 nm, the effect is not changed.
[0026]
As a method for measuring the film thickness of each layer, there are methods using a stylus roughness meter, a repetitive reflection interferometer, a microbalance, a crystal oscillator method, and the like. In particular, in the crystal oscillator method, the film thickness is measured during film formation. Since it is possible, it is suitable for obtaining a desired film thickness. There is also a method in which film forming conditions are determined in advance, a film is formed on a sample substrate, the relationship between the film forming time and the film thickness is examined, and the film thickness is controlled by the film forming time.
When the reflectance of the reflective sheet formed as described above is measured from the metal thin film layer side, a total reflectance of 90% or more is usually obtained at a wavelength of 550 nm.
[0027]
The value of the pencil scratch test of JIS K5400 on the reflecting surface of the reflector of the present invention produced by the method as described above is HB or higher, and when a dynamic microhardness meter is applied with a load of 9.8 mN for 5 seconds. The ratio with respect to the dent amount 5 seconds after unloading of the reflector surface is 0.7 or less, more preferably 0.5 or less. If the hardness greatly deviates from the above value, scratches may occur on the surface due to slight rubbing or stress during winding, transportation, handling, etc., which is not preferable.
[0028]
In the sidelight type backlight device of the present invention, the reflection sheet produced as described above is installed on the lower surface of the light guide plate with the metal thin film layer side as the upper surface. There is no problem as long as the backlight device is generally used as a sidelight type.
[0029]
The light guide plate used is, for example, in a wavelength range of about 400 to 700 nm such as acrylic resin such as polymethyl methacrylate, polycarbonate resin such as polycarbonate and polycarbonate / polystyrene composition, transparent resin such as epoxy resin, and glass. A material exhibiting transparency is preferably used. However, the material is not necessarily limited to this as long as the material exhibits transparency according to the wavelength region of the light source. Further, the thickness of the light guide plate can be appropriately determined depending on the size of the light guide plate to be used, the size of the light source, and the like.
[0030]
Examples of the light source to be used include incandescent bulbs, light emitting diodes (LEDs), electroluminescence (EL), fluorescent lamps, metal hydride lamps, etc. Among them, fluorescent lamps are preferably used. Fluorescent lamps are roughly classified into a hot cathode type and a cold cathode type depending on the electrode structure and lighting method, and the hot cathode type tends to be larger for both electrodes and inverters. The hot-cathode type is less efficient in the vicinity of the electrode that does not contribute to light emission and is more efficient. It exhibits luminous efficiency several times better than the cold-cathode type. The cold cathode type is more preferably used from the viewpoint of low power consumption and durability.
[0031]
In the surface light source device of the present invention, by using the reflector created by the method described above, even when the sheet is distorted, it does not appear as uneven brightness, and the conventional surface light source The brightness can be improved significantly compared to the device.
[0032]
【Example】
Hereinafter, the present invention will be described specifically by way of examples.
Example 1
Acrylic particles having an average particle diameter of 30 μm, acrylic resin (Tg = 56 ° C.) as the main material of the binder, aromatic isocyanate as the curing agent, the amount of particles to be 3.0 wt% with respect to the binder, and the solid content ratio After preparing a solution using a solvent consisting of toluene and ethyl methyl ketone so that the amount was 35 wt%, coating was performed on a 188 μm PET film to obtain a projection on the A side. Next, acrylic particles having an average particle diameter of 1.5 μm, an acrylic resin as the main component of the binder, and a melamine resin as the curing material, the blending amount of the particles with respect to the binder is 5.0 wt%, and the solid content ratio is 20 wt%. After preparing a solution using a solvent consisting of toluene and ethyl methyl ketone so as to be, a B surface on a 188 μm PET film was applied to obtain a smooth surface.
Next, the surface A side is oxidized by a DC magnetron sputtering method using zinc oxide doped with 2% Al ₂ O ₃ (purity: 99.9%) as a target and argon having a purity of 99.5% as a sputtering gas. Zinc was formed to a thickness of 5 nm. Subsequently, without taking out this film from the sputtering apparatus, similarly, a DC magnetron sputtering method was used to target silver with a purity of 99.9%, argon with a purity of 99.5% as a sputtering gas, and a silver film with a thickness of 200 nm. It shape | molded so that it might become. Subsequently, without taking out the film from the sputtering apparatus, the target was zinc oxide doped with 2% Al ₂ O ₃ (purity 99.9%) by DC magnetron sputtering, and the purity was 99.5%. Zinc oxide was formed to a thickness of 5 nm using argon as a sputtering gas, and a desired reflection sheet as shown in FIG. 1 was obtained. This reflective sheet was installed in a Hitachi's own spectrophotometer (model U-3400) with a 150φ integrating sphere, and the total reflectance and diffuse reflectance measured from the metal layer side at 550 nm were 95.3% total diffused and diffused. The reflectance was 6.3%, and the diffusivity was 6.6%. Next, when the height of the projection on the A side was measured at 10 points with a surface shape measuring device (DEKTAK3: manufactured by Veeco), the average value was 26.2 μm. There were 27 particles per mm ² . The reflective sheet after the measurement was placed in a constant temperature and humidity chamber, and left for 500 hours under wet heat conditions of 60 ° C. and 90% RH. After 500 hours, when the sheet was taken out and the surface was observed, no metal aggregation was observed. Moreover, as a result of measuring the total reflectance and the diffuse reflectance again with a spectrophotometer, the total reflectance was 95.1% and the diffuse reflectance was 6.7%, which was almost the same as before the wet heat.
Moreover, when the hardness of the reflective surface (A surface side) of this reflective sheet was measured, it was set to F by the pencil scratch value. In addition, when a dent when a load of 9.8 mN was applied for 5 seconds was measured with a dynamic microhardness meter manufactured by Shimadzu Corporation, the surface did not return to 1.53 μm and the surface did not return 5 seconds after unloading. The measured depth was 0.93 μm, and the ratio of the dent amount remaining during unloading to the dent amount generated during loading was 0.6. Next, when an acrylic ruler was pressed against the reflection surface of the reflection sheet, the surface was not noticeably scratched.
[0033]
Comparative Example 1
Acrylic particles having an average particle diameter of 30 μm, a polyester resin (Tg = 20 ° C.) as a main component of a binder, an aliphatic isocyanate as a curing agent, a blending amount of particles with respect to the binder of 4.5 wt%, and a solid content ratio of 28 wt. After preparing a solution using a solvent composed of toluene and ethyl methyl ketone so as to be%, coating was performed on a 188 μm PET film to obtain a projection on the A side. Then, it applied to the B surface side according to Example 1, and obtained the smooth surface. Furthermore, sputtering was performed according to Example 1 to obtain a reflector. The resulting reflective sheet was installed in a Hitachi auto-recording spectrophotometer (model U-3400) with a 150φ integrating sphere, and the total reflectance and diffuse reflectance measured from the metal layer side at 550 nm were 95.5% total reflectance, The diffuse reflectance was 5.6%, and the diffusivity was 5.7%. Next, when the height of the projection on the A side was measured by a surface shape measuring device (DEKTAK3: manufactured by Veeco), the average value was 25.2 μm. There were 30 particles per mm ² . The reflective sheet after the measurement was placed in a constant temperature and humidity chamber, and left for 500 hours under wet heat conditions of 60 ° C. and 90% RH. After 500 hours, when the sheet was taken out and the surface was observed, no metal aggregation was observed. Moreover, as a result of measuring the total reflectance and the diffuse reflectance again with a spectrophotometer, the total reflectance is 92.1% and the diffuse reflectance is 13.7%, which is lower than that before wet heat, The diffuse reflectance increased.
[0034]
Moreover, when the hardness of the reflective surface (A surface side) of this reflective sheet was measured, the pencil scratch value was 6B. In addition, when a dent when a load of 9.8 mN was applied for 5 seconds with a dynamic microhardness meter manufactured by Shimadzu Corporation was measured, the surface did not return to 2.07 μm and the surface did not return 5 seconds after unloading. The measured depth was 1.70 μm, and the ratio of the dent amount remaining during unloading to the dent amount generated during loading was 0.82. Next, when an acrylic ruler was pressed against the reflection surface of the reflection sheet, the surface remained after being pressed against the surface.
[0035]
[Table 1]

[0036]
[Table 2]

[0037]
[Table 3]

[0038]
【The invention's effect】
By using the reflective substrate of the present invention, defective scratches are less likely to occur in the manufacturing process and the processing process, and the handling and productivity are improved. Further, the sidelight type backlight device incorporating the reflector according to the present invention is a liquid crystal display with good visibility since the luminance unevenness due to the distortion does not occur even if the reflector is distorted in the backlight device. Can be provided. In addition, since the reflector has higher luminance and superior durability than conventional reflectors, it can provide uniform and high-intensity light over a long period of time, thereby improving the display performance of the liquid crystal. Therefore, the industrial significance of the present invention is great.
[Brief description of the drawings]
FIG. 1 is a sectional view showing an example of a reflection sheet in the present invention. FIG. 2 is an example of a surface light source device of the present invention.
DESCRIPTION OF SYMBOLS 10 Reflective layer 20 Protrusion 30 Polymer film 40 Cold cathode tube 50 Lamp reflector 60 Light guide plate 70 Reflective sheet

Claims (5)

A reflector comprising at least a substrate, a concavo-convex layer and a reflective layer, and a coating liquid comprising particles having an average particle diameter of 5 μm to 50 μm and a binder resin having a glass transition temperature of 40 ° C. or higher is applied to the substrate The concavo-convex layer thus formed has 2 to 100 protrusions per 1 mm ² with a maximum width of 10 μm to 50 μm and a height of 5 μm to 45 μm, and a dynamic microhardness meter applies a load of 9.8 mN for 5 seconds. dent amount proportion of 5 seconds after unloading for dent quantity of the reflector surface when the can is more than 0.7, the value of the pencil scratch test of JIS K5400 of the reflecting surface surface is not less than HB, the total A reflector having a ratio of diffuse reflectance to reflectance (diffusivity) of 1% to 50%. 2. The reflector according to claim 1 , wherein a surface of the substrate on which the reflective layer is not formed is subjected to an easy slip treatment. A sidelight type backlight device, wherein the reflector according to claim 1 or 2 is disposed on a lower surface of a light guide plate that emits light incident from a light source installed on a side surface to an upper surface. 4. The sidelight-type backlight device according to claim 3 , wherein a reflector is disposed so that the reflective layer is on the light guide plate side. A liquid crystal display device comprising the sidelight type backlight device according to claim 4 .

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