CN100412574C

CN100412574C - Method for producing mold for use in duplicating light diffusion sheet, light diffusion sheet and method for producing the same, and screen

Info

Publication number: CN100412574C
Application number: CNB2005100783464A
Authority: CN
Inventors: 木曾弘之; 工藤孝夫; 小田桐广和; 长浜勉
Original assignee: Sony Corp
Current assignee: Sony Corp
Priority date: 2004-02-04
Filing date: 2005-02-04
Publication date: 2008-08-20
Anticipated expiration: 2025-02-04
Also published as: CN101310928A; CN1721885A

Abstract

A method of producing a mold for use in duplicating a light diffusion sheet is provided. The method includes a step of conducting sandblasting for blasting abrasive material from a blast gun to a surface of a mold base material to form unevenness in the surface of the mold base material, wherein the abrasive material is blasted to the surface of the mold base material at a blast angle of less than 90 DEG .

Description

A kind of light diffusion sheet and screen thereof

The cross-application of related application

The present invention comprises and the Japanese patent application JP2004-027898 technical scheme of submitting in Jap.P. office respectively on February 4th, 2004 and on January 28th, 2005 relevant with JP2005-21939, and the full content of these two patented claims is incorporated this paper by reference into.

Technical field

The present invention relates to a kind of production and duplicate method, a kind of light diffusion sheet and production method thereof and a kind of screen of the mould that light diffusion sheet uses.

Background technology

In recent years, as the device of demonstration data in meeting etc., overhead projector and slide projector have obtained using widely.In addition, video projector and the film projector that is used for the employing liquid crystal of family expenses popularized.Projecting method in these projector is such: by, for example, the transmittance liquid crystal display is modulated the light that sends from light source, forming image light, and image light is transmitted on the screen through optical element (such as camera lens).

For example, the projector equipment that can form coloured image on screen comprises: lamp optical system, this optical system will be divided into red (R) light, green (G) light and indigo plant (B) light light beam from the light beam that light source sends, and with each beam convergence on predetermined light path; Liquid crystal display (light valve), this liquid crystal display is modulated one by one to the luminous flux of the RGB color told by lamp optical system; With the light compositing part, this part is synthesized the luminous flux through the RGB color of liquid crystal display modulation, and by projection lens to amplifying by the partly synthetic coloured image of light compositing and it being projected on the screen.

In addition, recently, developed a kind of employing arrowband three-primary colours light source and come the luminous flux of RGB color is carried out the projector equipment of the type of spatial modulation as light source and employing grating light valve (GLV) replacement liquid crystal display.

In above-mentioned projector equipment, the screen that has used projector to use is watched projected image.The screen that projector is used can be divided into screen that is used for front projector (front projector) and the screen that is used for rearmounted projector (rear projector) roughly, under the situation of the screen that is used for front projector, image light is to throw from the front side of screen, thereby what see is projected light by screen reflection, and under the situation of the screen that is used for rearmounted projector, image light is from the projection of the rear side of screen, thereby what see is to pass the light of screen from the front side transmission of screen.The screen of any kind all needs to have good identifiability and big viewing angle.

For this reason, in the screen of any kind, in general, on the surface of screen, be formed for the light diffusion sheet of scattered beam, and light diffusion sheet makes the even scattering of image light and emit from the whole effective coverage of screen.

As the method for producing light diffusion sheet, existing a kind of like this method: the speckle pattern that causes when in photosensitive resin, being formed on coherent light flux irradiation rough surface produce light diffusion sheet (referring to, for example, Japanese Patent Application Publication S53-51755 and 2001-100621), also has a kind of like this method: the preparation mask, and with this mask seam on photosensitive resin, produce light diffusion sheet, also have a kind of like this method in addition: the surface of directly grinding such as the mould host material of metal or resin etc. by mechanical treatment prepares the mould with formed trickle uneven surface, and the surface configuration of mould is passed to ultraviolet curable resin waits and produce light diffusion sheet.

In addition, also has a kind of like this method: will comprise the composition that is dispersed in the resin particle in the resin binder and be coated to grow light diffusion sheet on the transparency carrier, and a kind of like this method: prepare mould with uneven surface by the mould host material is carried out blasting treatment, and with the surface configuration of mould pass to ultraviolet curable resin wait produce light diffusion sheet (referring to, for example, Japanese Patent Application Publication 2000-284106).

By the way, usually need light diffusion sheet to have such attribute: make the scope of being pointed to expectation by the light of light diffusion sheet scattering, that is, vertically the scattering angle on is different from scattering angle transversely.In the production of light diffusion sheet, adopted and speckle interfered or mask pattern passes to the method for photosensitive resin.

Summary of the invention

Yet, according to the method that seam speckle on photosensitive resin is interfered or mask pattern is produced light diffusion sheet, when producing a plurality of light diffusion sheet, must prepare the mould that is used for duplicating light diffusion sheet, and the exposure of every square metre photosensitive resin need reach the time shutter of a few hours and even a couple of days by photosensitive resin.In addition, after exposure, need carry out the usability photopolymer resin duplicate light diffusion sheet step, give step that electricity leads, electroforming step or the like step, and need the quite very long time and expensive in the process that production is used for the mould of light diffusion sheet.

Produce in the method for light diffusion sheet by the mould that the surface of mould host material is carried out the mechanical lapping preparation in use, exist some shortcomings like this: the precision of grinding can't be satisfactory, instrument is damaged in the process of lapping, need the very long time grind and the equipment that is used to grind very big.

On the other hand, according to using the method for producing light diffusion sheet by the mould of sandblast preparation, production mould does not need long time or high cost, but in general the light by the light diffusion sheet scattering of producing by this method be isotropic in the vertical and transversely, therefore restive vertically going up and scattering angle transversely consequently makes scattered light point to and has the long limit rectangular shape in the horizontal or the scope of elliptical shape.Be applied to and also found this shortcoming in the method for producing light diffusion sheet on the transparency carrier will comprising the composition that is dispersed in the resin particle in the resinoid bond.

At the existing screen that is used for front projector, the scattering properties of screen is uniformly on whole surface, therefore, the gain of screen is high more, luminance difference between screen center section and the marginal portion is big more, so the image on the screen center section is bright, and the image dimness on the marginal portion.This trend also can be seen at the screen that is used for rearmounted projector.

For example, be used for the screen of front projector, in general, image shows it is by carrying out the method for projection at a certain angle forward downwards or carry out the method for projection at a certain angle forward downwards and realize from being placed on front projector on desk or the floor from being fixed on front projector (projector equipment) on the ceiling.In this case, when the screen that is used for front projector comprises existing isotropic scatterning sheet or anisotropic scattering sheet, such defective can occur: the high-high brightness of image light is not pointed to the beholder, as shown in figure 17.

On the other hand, in the display that comprises rearmounted projector (projector equipment) and transmissive viewing screen, the height of the topmost of screen is identical with the height of the beholder's who is seated sight line, and therefore such shortcoming can occur: the image on the screen bottom is dull, as shown in figure 18.

Therefore, expectation provides a kind of production and duplicates the method for the mould that light diffusion sheet uses and/or the method for producing light diffusion sheet, such method can have the light diffusion sheet of such scattering angle with low-cost production: during transmittance or reflection, scattering angle vertically is different from scattering angle transversely, and perhaps the scattering properties on vertical and horizontal has anisotropy.In addition, the screen of expecting to provide a kind of light diffusion sheet of producing according to the method and/or using this light diffusion sheet.The present invention makes with the problem relevant with prior art in view of the foregoing.

The present inventor finds, the existing method of using blasting treatment production to duplicate the mould that light diffusion sheet uses has such shortcoming: abrasive substance is sprayed along the direction on the surface that is substantially perpendicular to the mould host material, to grind this surface expeditiously.In other words, this method has formed the coarse structure at the vertical and horizontal isotropy on the surface of mould host material, can not produce the mould that is used to duplicate the light diffusion sheet with such scattering angle, wherein the scattering angle on vertically is different from scattering angle transversely.In order to solve or to alleviate this defective, the inventor has thought in blasting treatment and abrasive substance to be ejected into the lip-deep method of mould host material, and this method has been carried out extensive research, thereby has drawn thinking of the present invention.

In addition, the present inventor finds, the reason that causes this defective of luminance difference between the center section of screen and peripheral part is, center section at screen, the incident angle of projector light is that 0 ° and reflected light with maximum amount partly reflect towards the beholder, yet, peripheral part at screen, the incident angle of projector light is not a partly lateral reflection outside screen of 0 ° and reflected light with maximum amount, and the reflected light that so only has little light quantity partly is towards the beholder's reflection that is positioned at screen the place ahead.The inventor is according to having carried out extensive and deep research by the discovery that the research that abrasive substance is ejected into the lip-deep method of mould host material in the sandblast process is drawn.Therefore, present embodiment is in order to solve or to alleviate this defective and make.

According to embodiments of the present invention, provided the method for the mould that a kind of production uses in duplicating the light diffusion sheet process, the method comprising the steps of: implement sandblast, abrasive substance is ejected into from spray gun on the surface of mould host material, uneven or coarse to form on the surface of mould host material, wherein abrasive substance is to be ejected on the surface of mould host material with the spray angle less than 90 °.

Preferably, sandblast is performed such: the surface of mould host material and the angle between the spray gun are within 0-60 ° scope.

According to another embodiment of the invention, provided a kind of method of producing light diffusion sheet, this method comprises that direct or indirect use mould duplicates the step of light diffusion sheet, wherein this method uses the mould conduct that forms like this to be used to duplicate the mould of light diffusion sheet: implement sandblast, abrasive substance is ejected into from spray gun on the surface of mould host material, uneven to form on the surface of mould host material, wherein abrasive substance is to be ejected on the surface of mould host material with the spray angle less than 90 °.

According to another embodiment of the invention, provided a kind of light diffusion sheet, comprise the light scattering face that obtains by uneven structure transmission by the surface of blasting treatment, wherein sandblast is to carry out with the abrasive substance spray angle less than 90 °.

According to another embodiment of the invention, provided a kind of light diffusion sheet, comprise light scattering face with such scattering properties, wherein vertically go up scattering properties and be different from transversely scattering properties, wherein this light diffusion sheet has the axle offset of the high-high brightness on vertical and horizontal one or both of, and the axle offset of high-high brightness is detected at the angle-dependence that is transmitted into the photo measure brightness of the light of scattering from scattering surface on the scattering surface with 0 ° incident angle the time.

According to another embodiment of the invention, provided a kind of light diffusion sheet, comprise light scattering face with such scattering properties, wherein vertically go up scattering properties and be different from transversely scattering properties, be to measure wherein with such method at the angle-dependence that is transmitted into the light brightness of the light of scattering from scattering surface on the scattering surface with 0 ° incident angle: vertical and horizontal any one or the two on, the high-high brightness axle is angled with respect to the normal direction of the first type surface of light diffusion sheet, and wherein Luminance Distribution is asymmetric with respect to the high-high brightness axle.

According to another embodiment of the invention, provided a kind of light diffusion sheet, comprise light scattering face with such scattering properties, wherein vertically go up scattering properties and be different from transversely scattering properties, wherein the light scattering mask has trickle surface cell, these trickle surface cells have the structure that rises or descend, and are asymmetric with respect to the normal direction of the first type surface of light diffusion sheet.

Preferably, spacing is arranged is 300 μ m or littler uneven structure to the light scattering mask.

According to another embodiment of the invention, provided a kind of screen, comprise: light diffusion sheet, this light diffusion sheet comprises the light scattering face with such scattering properties, wherein vertically go up scattering properties and be different from transversely scattering properties, and this light diffusion sheet has the axle offset of the high-high brightness on vertical and horizontal one or both of, and this axle offset is by at the angle-dependence that is transmitted into the photo measure brightness of the light of scattering from the scattering surface on the scattering surface with 0 ° incident angle and detected.

Preferably, axle offset is on the direction at screen middle part.

According to another embodiment of the invention, provided a kind of screen, comprising: according to the light diffusion sheet of aforementioned any embodiment; Be formed on this light diffusion sheet, reflection horizon on the opposite side with light scattering face.

According to another embodiment of the invention, provided a kind of screen, comprise: according to the light diffusion sheet of aforementioned any embodiment, wherein this light diffusion sheet transmission is from the light of a side opposite with light scattering face projection, and scattering and send the light of the light scattering face of passing.

According to the embodiments of the present invention of introducing previously, by the high precision sandblast, can on the surface of mould host material, form coarse structure at an easy rate, wherein coarse structure shape in the vertical is different from shape transversely, and the mould that can duplicate light diffusion sheet can be produced by this independent operation of sandblast.

In addition, according to embodiments of the present invention, the mould that is used to duplicate light diffusion sheet by use, can accurately produce light diffusion sheet at an easy rate: during transmittance or reflection with such scattering angle, scattering angle vertically is different from scattering angle transversely, and perhaps the scattering properties on the vertical and horizontal has anisotropy.

In addition, by the light diffusion sheet of introducing above in screen, using, can be with the light-operated visual field of pointing to expectation of making of sending from any part of screen, therefore can obtain high, brightness uniformly or gain, feasiblely like this provide screen to become possibility with good identifiability.

Description of drawings

By the introduction of current exemplary embodiments of the present invention being carried out below in conjunction with accompanying drawing, above and other objects of the present invention, feature and advantage will become more apparent, wherein:

Figure 1A and 1B are that the synoptic diagram that in the method for the mould that light diffusion sheet uses the mould host material is carried out sandblast is duplicated in expression according to the production of embodiments of the present invention;

Fig. 2 is expression according to the synoptic diagram of surface configuration of mould that is used to duplicate light diffusion sheet of embodiments of the present invention;

Fig. 3 A and 3B are that the synoptic diagram that in the method for the mould that light diffusion sheet uses the mould host material is carried out sandblast is duplicated in expression according to the production of embodiments of the present invention;

Fig. 4 is spray gun scanning process in the method for the mould that light diffusion sheet uses is duplicated in expression according to the production of embodiments of the present invention a synoptic diagram;

Fig. 5 is the sectional view of expression according to the structure of the reflective viewing screen of embodiments of the present invention;

Fig. 6 is the sectional view of expression according to the structure of the transmissive viewing screen of embodiments of the present invention;

Fig. 7 represents that being used among the embodiment 1 duplicate the microphoto of surface state of the mould of light diffusion sheet;

Fig. 8 is the curve map of surface roughness that duplicates expression being used among the embodiment 1 mould of light diffusion sheet;

Fig. 9 A and 9B are the curve maps of the scattering angle of the light diffusion sheet among the expression embodiment 2;

Figure 10 is the curve map of the relation between the anisotropy (axle offset angle) of the scattering properties of spray angle and light diffusion sheet among the expression embodiment 3;

Figure 11 is the microphoto of surface state that duplicates expression being used among the embodiment 5 mould of light diffusion sheet;

Figure 12 A and 12B are the curve maps of surface roughness that duplicates expression being used among the embodiment 5 mould of light diffusion sheet;

Figure 13 is the curve map of frequency distribution at pitch angle of the trickle surface cell of the expression mould that duplicates light diffusion sheet with respect to being used among the embodiment 5;

Figure 14 A and 14B are the curve maps of the Luminance Distribution of the light diffusion sheet among the expression embodiment 5;

Figure 15 A and 15B are the curve maps of the Luminance Distribution of the light diffusion sheet among the expression embodiment 7;

Figure 16 A and 16B are the curve maps of the Luminance Distribution of the light diffusion sheet among the expression embodiment 8;

Figure 17 A and 17B are the key diagrams to the Luminance Distribution of existing reflective viewing screen; With

Figure 18 is the key diagram to the Luminance Distribution of existing transmissive viewing screen.

Embodiment

Hereinafter, will introduce a kind of method of the production light diffusion sheet according to embodiments of the present invention.

The method of producing light diffusion sheet comprises produces step of duplicating the mould that light diffusion sheet uses and the step of using this mould to duplicate light diffusion sheet.

(1) produces the step duplicate the mould that light diffusion sheet uses

Fig. 1 represents to duplicate the production run of the mould that light diffusion sheet uses, and wherein by blasting craft the surface of mould host material 1 is handled, and duplicates the mould that light diffusion sheet is used with production.

Sandblast is a kind of like this processing: abrasive substance 3 is ejected on the surface of mould host material 1 from the spray gun 2 of sand-blasting machine (not shown), make the abrasive substance 3 and the surface of mould host material 1 collide, in mould host material 1, to form uneven surface.

Sand-blasting machine is a kind of like this equipment, by spraying pressure gas (such as air or nitrogen) abrasive substance 3 is ejected into from spray gun 2 on the surface that places the pending material on the worktable, handles with the surface to this material.According to present embodiment, mould host material 1 places on the worktable, and carries out blasting treatment under the predetermined condition that provides below.

Abrasive substance 3 preferably includes such particle, and this particle comprises materials such as resin, glass, pottery, and is spherical or corner angle are arranged, and for example, is polygonal, especially preferably has the particle at angle.The example of abrasive substance comprises beaded glass, zirconia particles, steel sand, alumina particle and silica dioxide granule.

Abrasive substance 3 preferably has the mean grain size of 1-1000 μ m, more preferably 5-600 μ m, further preferred 5-50 μ m.

Preferably, abrasive substance 3 has the weight of each particle 0.002-8mg.

Mould host material 1 is the thin slice that comprises the material that is suitable for carrying out blasting treatment.This material preferred resin or metal, such as aluminium, copper or steel, especially preferred aluminium.Mould host material 1 can have such size: a die host material is enough to form the light diffusion sheet that uses in the screen.In the continuous production of using the mould roller, the mould roller can have the width of enough light diffusion sheet width.

The sandblast condition of abrasive substance 3 can be such: the sandblast angle (angle of depression) of the first type surface of 3 pairs of mould host materials 1 of abrasive substance is less than 90 ° among Fig. 1.Specifically, the preferred 0-60 of angle θ between the surface of mould host material 1 and the spray gun 2 °, more preferably 0-20 °, further preferred 0-10 °.

For example, according to present embodiment, when with 10 ° angle θ jet grinding material, can change on the injection direction of abrasive substance 3 and perpendicular to the spacing of the groove on the direction of this injection direction, and the surface roughness profile on the injection direction can be with respect to master meter over glaze (normal) symmetry of light diffusion sheet in addition.

With the abrasive substance 3 of mould host material 1 collision when energy reduces, grind the surface of mould host material 1 or make this surface deformation, go out along the angular dispersed that makes progress from mould host material 1 then, but, when abrasive substance 3 is when being sprayed under above-mentioned injection conditions, abrasive substance 3 collides with mould host material 1 at a certain angle, and therefore owing to laterally (X-direction) and the vertically effect of the collision between (Y direction), has caused the difference of form of distortion.For example, under the condition of Fig. 1, the deformed shape on the X-direction (pit) is longer than the deformed shape on the Y direction.In other words, the surfaceness on the X-direction has the spacing longer than the surfaceness on the Y direction.The parameter that comprises the surfaceness of spacing can be controlled by the parameter and the sandblast condition (for example, the injection conditions of abrasive substance 3) that change mould host material 1, abrasive substance 3.For example, when using the big abrasive substance of particle diameter, can be implemented in the surfaceness that all has big spacing on X and the Y direction, when using the bigger abrasive substance of density, can realize dark groove.

With regard to the shape of treated mould host material 1, the type of the distance between angle, spray gun 2 and the mould host material 1 of the compressed-air actuated pressure that the shape after the processing on the injection direction of abrasive substance 3 can be by changing spray gun 2 (this pressure decision between injection period energy), spray gun 2, shape, density or the hardness of abrasive substance 3, mould host material waits to be controlled.Can be controlled by the shape or the hardness that change abrasive substance perpendicular to the shape after the processing on the direction of injection direction.In addition, make when energy reduces, make the track of the abrasive substance that mould host material 1 deforms and because the track of the abrasive substance 3 that the effect of repulsive force disperses out from mould host material 1 is asymmetric, and therefore can form the asymmetric surface configuration of master meter over glaze shown in Fig. 2 with respect to mould host material 1.

Vertically go up and transversely different scattering angle or have is vertically gone up and the light diffusion sheet of anisotropic scatter properties transversely by using the mould that light diffusion sheet is used that duplicates under above-mentioned injection conditions, produce, can produce to have.For example, under the injection conditions of the abrasive substance 3 in Fig. 1, reflected light or the transmitted light scattering angle on directions X is less, and the scattering angle on the Y direction is bigger, thereby reflected light or transmitted light have such scatter properties: the brightness peak axle on directions X to X ₁One lateral deviation is moved.

Selectively, reflected light or the transmitted light scattering angle on directions X can be less, and the scattering angle on the Y direction can be bigger, in addition, according at the measurement result of the angle-dependence of the luminance brightness of scattering from the scattering surface that is transmitted into 0 ° of incident angle that light on the scattering surface draws, the high-high brightness axle can become the angle at X with respect to the normal direction of the first type surface of light diffusion sheet ₁Side, wherein Luminance Distribution can be asymmetric with respect to the high-high brightness axle.

Along with the angle between spray gun 2 and the mould host material 1 reduces, in other words, angle θ is more little, and the length-diameter ratio of the scattering angle of the light diffusion sheet of introducing below obtains increasing, and therefore the anisotropic influence of scatter properties is just obvious more.

Abrasive substance 3 is that the angle θ of α is ejected on the mould host material 1 from spray gun 2 with the angular breadth.In other words, abrasive substance 3 is with at angle beta ₁-β ₂Scope in angle and mould host material 1 collide.In general angular breadth α is approximately 10 °.

When to the handling than the zonule of mould host material 1, angular breadth α can reduce, and perhaps the distance L between spray gun 2 and the mould host material 1 can reduce.When the big zone of mould host material 1 is handled, can in steady mobile spray gun 2 or mould host material 1, implement blasting treatment.

In the above description, abrasive substance 3 sprays along a direction, promptly, along the direction on the long limit of mould host material 1 (X-direction in Fig. 1 (b)), make abrasive substance 3 to the spray angle (angle of depression) of the first type surface of mould host material 1 less than 90 °, but, can with the spray angle identical angle of depression jet grinding material 3 of above-mentioned abrasive substance 3 to the first type surface of mould host material 1, and further with the angle jet grinding material 3 of main shaft to the first type surface of mould host material 1 (plane that limits by X and Y-axis).

For example, as shown in Figure 3, abrasive substance 3 is angle of depression θ to the spray angle of the first type surface of mould host material 1 ₁(Fig. 3 (a)), and spray gun 2 is arranged to and the angled θ of X-axis ₂Like this, emission light or transmitted light has such scatter properties: the brightness peak axle along X-direction to X ₁Lateral deviation is moved, and along Y direction to Y ₁Lateral deviation is moved.

According to present embodiment,, make the entire main surface of mould host material 1 all obtain blasting treatment by in jet grinding material from spray gun 2, above mould host material 1, scanning spray gun 2.

Provided the example that spray gun 2 scans among Fig. 4.In jet grinding material 3 from spray gun 2, spray gun 2 moves above mould host material 1 with the direction of constant speed along Y-axis, and, the collision area of abrasive substance 3 reach module host material 1 with subterminal the time, spray gun 2 moves certain interval along X-direction, moves with the reverse direction of constant speed along Y-axis then.Subsequently, at every turn when the collision area of abrasive substance 3 reach the mould host material with proximal end the time, spray gun 2 all moves certain interval along X-direction, shift action overturns along Y direction then, and proceed blasting treatment, so just on entire die host material 1, formed the uneven surface of expectation.

Preferably, will adjust to such an extent that make the adjacent area of abrasive substance 3 collision overlap onto certain degree and mould host material 1 has whole uneven surfaces along the spacing that X-direction moves.Selectively, the collision area of abrasive substance 3 can be covered by mask, so that abrasive substance 3 only collides at the mesozone and the mould host material 1 of collision area.

Scan method can be fixing and the method that spray gun 2 moves of mould host material 1, or the worktable of placing mould host material 1 moves and method that spray gun 2 moves along Y direction along X-direction.

With regard to the injection conditions of abrasive substance 3, scanning can be implemented to such an extent that make the surface of mould host material 1 and the angle θ between the spray gun 2 keep constant, as shown in Figure 1, over-angle θ can not change according to the position of mould host material 1 on X-axis and Y-axis coordinate.

(2) duplicate the step of light diffusion sheet

The production of Jie Shaoing is in the above duplicated the mould that being used to of producing in the step of the mould that light diffusion sheet uses duplicate light diffusion sheet and is had trickle sculpture surface, and this surface has predetermined coarse structure.Light diffusion sheet can utilize trickle sculpture surface to produce.According to present embodiment, can use any direct or indirect employing to be used to duplicate the rapid-result mould (instant mold) of light diffusion sheet, produce the method for light diffusion sheet by trickle sculpture surface.

For example, the method that directly adopts mould to duplicate light diffusion sheet can comprise such method: handle and produce light diffusion sheet by utilizing mould to carry out pressure forming, for example, by mould being pressed in the light diffusion sheet that is shaped and duplicates on the thermoforming plastic film.Selectively, can be by ultraviolet curable resin being coated on the mould and covering it, takes off the light diffusion sheet that the resin of curing obtains to expect by this resin of irradiation ultraviolet radiation photocuring and from mould then with transparency carrier.In addition, selectively, can by repeat above-mentioned with resin-coating to mould and the disposal route of solidifying this resin that covers with transparency carrier produce the light diffusion sheet that comprises the lamination curing resin layer.In order to improve the demolding performace of moulding material from the mould, preferably adopt nickel evaporation, fluorinated material, the coating of silicon based material etc. that the die surface that will carry out the demoulding is handled.

The method that indirectly is used for duplicating the mould of light diffusion sheet can comprise a kind of like this method: the mould that being used to of processing in the above-mentioned procedure of processing that is used to duplicate the mould of light diffusion sheet can be duplicated light diffusion sheet is made mother matrix, and can be by producing the such mother matrix mould of electroforming mould reflex system of this mother matrix, can adopt this to duplicate the mould that obtains then and duplicate light diffusion sheet according to the similar mode of the method for duplicating light diffusion sheet to above-mentioned direct employing mould.Selectively, after the electroforming mould of having produced anti-shaping (reverse-shaped), can adopt to make such as the transparency carrier of non-alkali glass etc. and transmit the mould that duplicates, this transparency carrier absorbs very little in ultraviolet light range.When the copy of light diffusion sheet is to adopt ultraviolet resin solidification to make, use transparent mould can realize by coming cured resin from mould one side irradiating ultraviolet light.

Preferably, employed ultraviolet curable resin has optical transparence.Can use various resins, such as acryl resin, vibrin, Polyvinylchloride, polyurethane and silicones, but not special restriction.Can add and be used on a small quantity to prevent that UV-irradiation from causing the ultraviolet absorber of cured resin degraded, perhaps in the painted application of needs, add absorber of light.

In addition, as the material that constitutes light diffusion sheet, can adopt the thermoformable plastics or the irradiation cured resin of the fine particle that comprises the refractive index that is used to control light diffusion sheet, and the example of the fine particle that is added comprises the alloyed oxide of the oxide of Ti, Zr, Al, Ce, Sn, La, In, Y, Sb etc. and In-Sn etc.When the Ti oxide contained the oxide that is useful on an amount of Al, the Zr etc. that suppress photocatalysis, the effect of present embodiment can not destroyed.

Fine particle preferably has 55-85m ²The specific surface area of/g, more preferably 75-85m ²/ g.When the specific surface area of fine particle drops in this scope, fine particle is carried out dispersion treatment can make fine particle have 100nm or littler particle diameter at the material that is used for optical thin film, the optical thin film that makes acquisition have very little turbidity becomes possibility like this.

According to fine particle, with 3.2-9.6 * 10 ¹¹Mol/m ²Dosage add the spreading agent be used to disperse fine particle, and, when the dosage of spreading agent during, can't in light diffusion sheet, obtain the particle dispersion degree of being satisfied with less than this scope.On the other hand,, spreading agent is increased the volume ratio of institute's coated film, so that reduced the refractive index of film, thereby the scope of the refractive index that can adopt narrows down, make the design light diffusion sheet become difficult like this when the dosage of spreading agent during greater than this scope.

The dosage of polar functional group (hydrophilic group that comprises in the spreading agent) is 10 ^-3-10 ^-1Mol/g.When the dosage of this functional group less than or during greater than this scope, the effect of the dispersion aspect of fine particle can not show, and causes dispersion degree to reduce.

Functional group given below is effective polar functional group, because they can not cause gathering:

-SO ₃M ,-OSO ₃M ,-COOM, P=O (OM) ₂(wherein M represents hydrogen atom or alkaline metal, such as lithium, potassium or sodium), tertiary amine and quaternary ammonium salt

R ₁(R ₂) (R ₃) NHX (R wherein ₁, R ₂And R ₃In each represent hydrogen atom or alkyl, and X ^-Represent the halogen ion, such as chlorine, bromine or iodine, perhaps inorganic or organic ion)

-OH ,-SH ,-CN, epoxy radicals etc.

With regard to the position of introducing polar functional group, have no particular limits.These spreading agents can be used singly or in combination.

According to present embodiment, the dosage of the spreading agent in the coated film (or total amount of spreading agent) is preferably the 20-60 weight portion, more preferably 38-55 weight portion (with respect to the ferromagnetic powder of 100 weight portions).With regard to the position of introducing polar functional group, have no particular limits.

Preferably, the lipophilic group in the spreading agent has the weight-average molecular weight of 110-3000.When the molecular weight of lipophilic group during less than this scope, such defective can occur: spreading agent is dissolved in the organic solution unsatisfactorily.On the other hand, when molecular weight during, can't in optical thin film, obtain gratifying dispersiveness greater than this scope.The molecular weight of spreading agent records by gel permeation chromatography (GPC).

Spreading agent can have the functional group that experiences curing reaction with bonding agent.If comprise the bonding agent except the spreading agent of present embodiment, preferably have the polyfunctional poly compound or the monomer of a plurality of conjugated groups.

In order to control the thickness of light diffusion sheet, can with an organic solvent dilute application composition, and, for example can use ketone solvent (such as acetone, methyl ethyl ketone, methylisobutylketone or cyclohexanone), alcoholic solvent (such as methyl alcohol, ethanol, propyl alcohol, butanols or isobutyl alcohol) or ester solvent (such as methyl acetate, ethyl acetate, butyl acetate, propyl acetate, ethyl lactate or acetate glycol ester).These organic solvents need be up to 100% purity, and they can comprise 20% or the impurity of following dosage, such as isomeride, unreacted reactant, decomposition product, oxide or moisture.For application composition being coated on the substrate with low-surface-energy, wish to select to have the solvent of low surface tension, and the example of such solvent comprises methylisobutylketone, methyl alcohol and ethanol.

The example that experiences the bonding agent of curing reaction with spreading agent comprises thermoset resin, ultraviolet ray (UV) cured resin and electron beam (EB) cured resin.The example of thermoset resin, UV cured resin and EB cured resin comprises polystyrene resin, styrol copolymer, polycarbonate, phenolics, epoxy resin, vibrin, urethane resin, urea resin (urea resins), melamine formaldehyde resin, polyamino resin and urea-formaldehyde resin (urea-formaldehyde resins).Can use the polymkeric substance of (aromatic series, heterocycle or the alicyclic) group that has other ring-type.Selectively, can use the resin that in its carbochain, has fluorine or silanol base.

The method that promotes the curing reaction of resin can be irradiation and add pine for any, and but, when the curing reaction of resin is irradiation by ultraviolet when obtaining promoting, preferably this reaction is to carry out in the presence of polymerization initiator.The example of radical polymerization initiator comprises that azo initiator is (such as 2,2 '-azoisobutyronitrile and 2,2 '-azo two (2, the 4-methyl pentane nitrile)) and peroxide initiator (crossing caprylate (t-butylperoctoate)) such as benzoyl peroxide, lauryl peroxide and the tert-butyl group.Total amount with respect to polymerisable monomer is 100 weight portions, the preferred 0.2-10 weight portion of the dosage of employed initiating agent, more preferably 0.5-5 weight portion.

Transparency carrier can be any material of optical property of meeting the expectation; for example; the transparent membrane that comprises polymkeric substance is such as polyethylene terephthalate (PET), poly-to (ethylene naphthalate) (PEN), polyethersulfone (PES), polyolefin (PO), glass plate, acrylic panel, methacryl styrene plate, polycarbonate plate or fluorine resin.Preferably, the material of formation transparency carrier has such optical property: refractive index is 1.3-1.6, and turbidity is 8% or littler, and transmittance is 80% or bigger.Transparency carrier can have anti-glare function.

The light diffusion sheet of present embodiment comprises the light scattering surface that the transmission (transfer) by the surface configuration of the mould of being produced by said method obtains, this light scattering surface has such light scattering character: the scatter properties vertically is different with scatter properties transversely, wherein light diffusion sheet has the journal offset of high-high brightness on vertical and horizontal one or both of, and this journal offset is by detecting from the angle-dependence of the brightness of the light of scattering surface scattering at the photo measure that is transmitted into 0 ° of incident angle on the scattering surface.

Selectively, the light diffusion sheet of present embodiment can comprise the light scattering face that obtains by the transmission by the surface configuration of the mould of said method production, this light scattering mask has such scatter properties: the scatter properties vertically is different from the scatter properties on the transverse axis, wherein, at being transmitted into photo measure on the scattering surface with 0 ° of incident angle from the process of the angle-dependence of the brightness of the light of scattering surface scattering, on vertical and horizontal one or both of, the normal direction of the first type surface of high-high brightness axle and light diffusion sheet is angled, and wherein Luminance Distribution is asymmetric with respect to the high-high brightness axle.

In addition, the light diffusion sheet of present embodiment comprises light scattering face, this light scattering face comprises a plurality of trickle surface cells with the structure that rises or descend, and this light scattering mask has such scatter properties: the scatter properties vertically is different with scatter properties transversely, wherein the light scattering mask has trickle surface cell, these trickle surface cells have the structure that rises or descend, and these trickle surface cells are asymmetric with respect to the normal of the first type surface of light diffusion sheet.

Introduce the reflective viewing screen of a kind of conduct now according to the screen of embodiments of the present invention.

Fig. 5 is the sectional view of the structure of expression reflective viewing screen of the present invention.

The reflective viewing screen of present embodiment comprises the light diffusion sheet 14 and the reflection horizon that is formed on the light diffusion sheet 14 according to the various implementations of present embodiment, this reflection horizon be formed at light scattering face opposite surfaces on, and the reflective viewing screen of present embodiment has such structure: for example, as shown in Figure 5, on substrate 11, be formed with optical multilayer 12, light absorbing zone 13 and light diffusion sheet 14.

Substrate 11 can comprise any material of the optical properties that meets the expectation, for example, and transparent membrane, glass plate, acrylic panel, methacryl styrene plate, polycarbonate plate, lens or fluorine resin.Preferably, the material of formation substrate 11 has such optical properties: refractive index is 1.3-1.6, and turbidity is 8% or littler, and transmittance is 80% or bigger.Transparency carrier 11 can have anti-glare function.

Optical multilayer 12 comprises: optical thin film 12H, have high index of refraction, and this refractive index is described belowly to be used for the application composition H of optical thin film and it is cured obtaining by applying; Optical thin film 12L has low-refraction, and this refractive index is described belowly to be used for the application composition L of optical thin film and it is cured obtaining by applying, wherein optical thin film 12H and optical thin film 12L be replace mutually stacked.Specifically, optical multilayer 12 has such structure: optical thin film 12H at first is formed on the substrate, optical thin film 12L is formed thereon then, alternately form optical thin film 12H and optical thin film 12L subsequently, and finally form optical thin film 12H, and preferred optical multilayer 12 is the stack membranes (wherein n is the integer more than or equal to 1) that comprise (2n+1) layer.

Optical thin film 12H is applied on substrate 11 or the optical thin film 12L and then by the application composition H that will be used for optical thin film said composition is cured the optical thin film that reaction forms.

This optical thin film preferably has the thickness of 80nm-15 μ m, more preferably 600-1000nm.When the thickness of optical thin film during greater than 15 μ m, the amount that comprises the muddy composition that does not disperse fine particle increases, and makes the function that meets the requirements that is difficult to realize optical thin film.

Optical thin film preferably has the refractive index of 1.6-2.1.When the refractive index of optical thin film was higher than 2.1, the dispersing characteristic of fine particle did not meet the requirements, thus the function of optical thin film destroyed, and when refractive index was lower than 1.6, required optical properties usually can not get.

Optical thin film 12L is applied to that optical thin film 12H goes up and contains fluorine film or contain silicon dioxide or contain the film of hollow thin microparticle what composition was cured that reaction forms then by the application composition L that will be used for optical thin film.

Optical thin film 12L especially preferably has 1.45 or littler refractive index.The type and the quantity of determining to depend on type that is included in the resin in the application composition and the fine particle of choosing wantonly of the refractive index of optical thin film 12L.

This optical thin film preferably has the thickness of 80nm-15 μ m, more preferably 600-1000nm.

Owing to have said structure, optical multilayer has the highly reflective energy for the light in three kinds of wavelength region may (that is, red, green and blue light), and has high transmission performance for the visible light at least in the wavelength region may outside these three kinds of wavelength region may.By changing refractive index or the thickness of each optical thin film 12H and optical thin film 12L, will can obtain by the wavelength in three wavelength region may of optical multilayer reflection adjusting and control, thereby optical multilayer can be tackled the light wavelength that projector sends preferablyly.

With regard to the number of plies of the optical thin film 12H that constitutes optical multilayer and optical thin film 12L, have no particular limits, and optical

thin film

12H, 12L can have the number of plies of expectation.Preferred optical multilayer comprises odd-level, so that the outermost layer on each side of projector light light incident side and opposition side thereof all comprises optical thin film 12H.The optical multilayer that comprises odd-level has than the better filter function of the optical multilayer that comprises even level for the wavelength region may of three-primary colours.

Specifically, preferred optical multilayer comprises the odd-level of scope within the 3-7 layer.When the number of plies is 2 or more hour, the function of optical multilayer does not conform with the requirement as the reflection horizon.On the other hand, the number of plies that constitutes optical multilayer is many more, and the reflection coefficient of optical multilayer is big more, but, when the number of plies more than or equal to 8 the time, the Magnification of reflection coefficient is very little, and expection can't obtain by increasing the effect that the time that forms optical multilayer improves reflection coefficient.

Light absorbing zone 13 absorbs the light that has passed optical multilayer 12, and for example, in Fig. 5, light absorbing zone 13 is by forming on the surface that on the opposite side on the surface that forms optical multilayer 12 the black application composition is applied to substrate 11.Selectively, also a black thin film can be stacked on this surface.

Light diffusion sheet 14 is that the method by aforementioned production light diffusion sheet obtains, and forms by being stacked on the optical multilayer 12.

Here, provided the example as the reflection horizon in optical multilayer 12 (wavelength selection type reflection horizon), but the reflection horizon is not limited to this reflection horizon in the present embodiment, but can is any reflection horizon that can reflected image light.Example comprises that use has the reflection horizon of the material of high reflectance in the wide wavelength coverage of visible light, such as aluminium or silver.

In reflective viewing screen 10, the light that sends from any part of this screen can be controlled to the visual field of pointing to expectation, and therefore can obtain even and high brightness or gain, making provides the screen that has good identifiability or be easy to identification more to become possibility.

Screen has suppressed the surface scattering of incident light on screen, and carry out the selective reflecting that may exist, make and obtain reflection from the light in the specific wavelength of projector, and the incident light in the wavelength region may except specific wavelength is (for example on the screen, surround lighting) all obtains transmission and absorption, reduced the black-level of the image on the reflective viewing screen 10, to have realized high-contrast, make the image of high-contrast to be apparent on the screen like this, even also be like this in bright room.For example, when the light that sends when from the rgb light source (such as the grating light valve projector that uses grating light valve (GLV)) projects on the screen 10, can in very big visual angle, see the good image that is not subjected to the surround lighting adverse effect with high-contrast.

Specifically, the light that incides on the reflective viewing screen 10 passes optical function diffusion sheet 11, on the surface of diffusion sheet scattering does not take place, and reach optical multilayer 12, these optical multilayer 12 transmissions are included in the surround lighting composition in the incident light, this surround lighting composition is absorbed by light absorbing zone 14, and have only the light in the useful particular wavelength region of image is obtained selective reflecting, and reflected light sends to the beholder by the surface scattering of optical function diffusion sheet 11 and as image light in very big visual angle.Therefore, almost can eliminate the adverse effect of surround lighting fully, make and realize that the much higher contrast of contrast than being obtained by existing screen becomes possibility image light (reflected light).

Here, will material H and the L that be used for optical thin film be described, these materials are the application compositions that are used to form optical thin film 12H and optical thin film 12L.

(1) is used for the material H of optical thin film

The application composition H that is used for optical thin film comprises fine particle, organic solvent, cementing agent (absorbing energy to be cured reaction) and spreading agent.

Described fine particle is the fine particle that comprises the high-index material that adds for the refractive index of controlling formed optical thin film, and example comprises the alloyed oxide of the oxide of Ti, Zr, Al, Ce, Sn, La, In, Y, Sb etc. and In-Sn etc.When the Ti oxide contained the oxide that is useful on an amount of Al, the Zr etc. that suppress photocatalysis, the effect of present embodiment can not destroyed.

-OH ,-SH ,-CN, epoxy radicals etc.

Spreading agent can have the functional group that experiences curing reaction with bonding agent.When the bonding agent that comprises except the spreading agent of present embodiment, preferably have the polyfunctional poly compound or the monomer of a plurality of conjugated groups.

As organic solvent, for example can use ketone solvent (such as acetone, methyl ethyl ketone, methylisobutylketone or cyclohexanone), alcoholic solvent (such as methyl alcohol, ethanol, propyl alcohol, butanols or isobutyl alcohol) or ester solvent (such as methyl acetate, ethyl acetate, butyl acetate, propyl acetate, ethyl lactate or acetate glycol ester).These organic solvents need be up to 100% purity, and they can comprise 20% or the impurity of following dosage, such as isomeride, unreacted reactant, decomposition product, oxide or moisture.For application composition being coated on the substrate or optical thin film with low-surface-energy, wish to select to have the solvent of low surface tension, and the example of such solvent comprises methylisobutylketone, methyl alcohol and ethanol.

The example that experiences the bonding agent of curing reaction with spreading agent comprises thermoset resin, ultraviolet ray (UV) cured resin and electron beam (EB) cured resin.The example of thermoset resin, UV cured resin and EB cured resin comprises polystyrene resin, styrol copolymer, polycarbonate, phenolics, epoxy resin, vibrin, urethane resin, urea resin, melamine formaldehyde resin, polyamino resin and urea-formaldehyde resin.Can use the polymkeric substance of (aromatic series, heterocycle or the alicyclic) group that has other ring-type.Selectively, also can use the resin that in its carbochain, has fluorine or silanol base.

The method that promotes the curing reaction of resin can be irradiation and add pine for any, and but, when the curing reaction of resin is irradiation by ultraviolet when obtaining promoting, preferably this reaction is to carry out in the presence of polymerization initiator.The example of radical polymerization initiator comprises that the nitrogen initiating agent is (such as 2,2 '-azoisobutyronitrile and 2,2 '-azo two (2, the 4-methyl pentane nitrile)) and peroxide initiator (crossing caprylate (t-butylperoctoate)) such as benzoyl peroxide, lauryl peroxide and the tert-butyl group.Total amount with respect to polymerisable monomer is 100 weight portions, and the dosage of employed initiating agent is preferably the 0.2-10 weight portion, more preferably the 0.5-5 weight portion.

The material H that coating is used for optical thin film is dried then, to form the optical thin film 22H of its uncured state, then in curing schedule, promotes the curing reaction of film by irradiation or heating, to form the optical thin film 12H of high index of refraction type.

(2) be used for the material L of optical thin film

The application composition L that is used for optical thin film comprises organic solvent and cementing agent.Cementing agent is dissolved in the organic solvent, and, if desired, can add fine particle, and fine particle is dispersed in the binder solution.

Cementing agent is such resin: have the irradiation by light such as ultraviolet lights or be cured the functional group of reaction by the energy that heating obtains in its molecule, and from the angle of being convenient to remove by isolated film (releasefilm), especially preferred fluorine resin.The preferred use has by the polymkeric substance of the main chain of fluorine modification, has by the polymkeric substance of the side chain of fluorine modification or have the monomer of fluorine.

The example that has by the polymkeric substance of the main chain of fluorine modification comprises perfluoro backbone chain type perfluoro polyether, perfluoro side chain type perfluoro polyether, pure modification perfluoro polyether and isocyanate-modified perfluoro polyether, and the example with monomer of fluorine comprises CF ₂=CF ₂, CH ₂=CF ₂And CF ₂=CHF.Also can use by these monomers being carried out the polymkeric substance that polymerization or block polymerization obtain.

As the example that has by the polymkeric substance of the side chain of fluorine modification, can mention the solvent soluble polymer of main chain with graft polymerization, and, especially preferred example as the low-refraction thermoplastic polymer, can mention polyvinylidene fluoride, because as the resin that can use solvent, can handle it at an easy rate.When polyvinylidene fluoride is used as the low-refraction thermoplastic polymer, the low-index layer that the result obtains has about 1.4 refractive index, and, in order further to reduce the refractive index of low-index layer, can add low-refraction acrylate (such as acrylic acid three fluoro ethyl esters), preferred 100-200 weight portion with dosage with respect to the 10-300 weight portion of 100 weight portions of ionizing radiation curable resin.

1.4), MgF fine particle is the fine particle that comprises randomly the low-index material that adds the refractive index of controlling formed optical thin film, and preferably includes (the refractive index: such as LiF ₂1.4), 3NaFAlF (refractive index: ₃1.4), AlF (refractive index: ₃1.4) or SiO (refractive index: _x(1.5≤x≤2.0) (refractive index: the superfine particle of material 1.35-1.48).Also can comprise the hollow thin microparticle.

As organic solvent, can for example use separately or with array mode, ketone solvent (such as acetone, methyl ethyl ketone, methylisobutylketone or cyclohexanone), alcoholic solvent (such as methyl alcohol, ethanol, propyl alcohol, butanols or isobutyl alcohol) or ester solvent (such as methyl acetate, ethyl acetate, butyl acetate, propyl acetate, ethyl lactate and acetate glycol ester), contain fluorous solvent (such as fluorine-containing aromatic hydrocarbon, for example, full-fluorinated benzene, phenyl-pentafluoride, 1,3-two (trifluoromethyl) benzene and 1,4-two (trifluoromethyl) benzene; Fluorine-containing alkyl amine, for example, perfluor tri-butylamine and PFTPA; Fluorine-containing aliphatic hydrocarbon, for example, perflexane, PFO, perfluoro decane, the perfluor dodecane, perfluor-2,7-dimethyl octane, 1,3-two chloro-1,1,2,2, the 3-pentafluoropropane, 1H-1,1-dichloro perfluoropropane, 1H-1,3-dichloro perfluoropropane, the 1H-perfluorinated butane, 2H, the 3H-perflenapent, 3H, 4H-perfluor-2-methylpentane, 2H, 3H-perfluor-2-methylpentane, perfluor-1, the 2-dimethylhexane, perfluor-1, the 3-dimethylhexane, the 1H-perflexane, 1H, 1H, 1H, 2H, the 2H-perflexane, 1H, 1H, 1H, 2H, 2H-PFO, the 1H-PFO, 1H-perfluoro decane and 1H, 1H, 1H, 2H, 2H-perfluoro decane; Fluorine-containing alicyclic hydrocarbon, for example, perfluorodecalin, perfluor cyclohexane and perfluor-1,3,5-trimethyl-cyclohexane; With fluorine-containing ether, for example, perfluor-2-butyl tetrahydrofuran and fluorine-containing low molecular polyether).These organic solvents need be up to 100% purity, and they can comprise 20% or the impurity of following dosage, such as isomeride, unreacted reactant, decomposition product, oxide or moisture.

Apply the material L that is used for optical thin film and dry then, be in the optical thin film 22L of its uncured state, then in curing schedule, promote the curing reaction of film by irradiation or heating, to form the optical thin film 12L of low-refraction type with formation.

Then, will introduce method below according to the production reflective viewing screen 10 of embodiments of the present invention.

(S1) preparation polyethylene terephthalate (PET) film as substrate 11, and is applied to the first type surface of substrate 11 according to the application composition H that scheduled volume will be used for optical thin film.

(S2) oven dry is used for the film of the application composition H of optical thin film, is cured by UV-irradiation then, has the optical thin film 12H of predetermined thickness with formation.

(S3) then, the application composition L that will be used for optical thin film according to scheduled volume is applied to optical thin film 12H.

(S4) film that obtains of oven dry result is cured by heating then, has the optical thin film 12L of predetermined thickness with formation, has formed the rhythmo structure that comprises optical thin film 12H and optical thin film 12L like this.

(S5) then, the application composition H that will be used for optical thin film according to scheduled volume is applied to the outermost optical thin film 12L that constitutes substrate 11.

(S6) oven dry is used for the film of the application composition H of optical thin film, by UV-irradiation it is cured then, has the optical thin film 12H of predetermined thickness with formation.

Subsequently, the circulation of the processing among the step S3-S6 is repeated pre-determined number, so that on substrate 11, form optical multilayer 12.

(S7) with low-refraction transparent adhesive (EPOTEK396; By EPOXY TECHNOLOGY production and selling) be applied on the outermost surface of optical multilayer 12, and light diffusion sheet 14 is placed on the bonding agent that is applied, make the surface of light diffusion sheet 14 on an opposite side contact with bonding agent with uneven surface, then bonding agent is solidified, so that play the effect of the adhesive linkage that optical multilayer 12 and light diffusion sheet 14 are bonded together.

(S8) resin that will comprise the black light absorber is applied to the back side of substrate 11, to form light absorbing zone 13, has so just obtained reflective viewing screen 10 of the present invention.

Below, will introduce as transmissive viewing screen according to the screen of another embodiment of the invention.

Fig. 6 is the sectional view of structure of the transmissive viewing screen of expression present embodiment.The transmissive viewing screen of present embodiment comprises the light diffusion sheet of present embodiment, wherein the light diffusion sheet transmission is from light and the scattering and the light of launching the light scattering face that passes of opposite side projection with light scattering face, for example, as shown in Figure 6, transmissive viewing screen comprises the light diffusion sheet 102 that is positioned on the substrate 101.

Substrate 101 is the substrates that are used for transmissive viewing screen, and can constitute by polymkeric substance, such as polyethylene terephthalate (PET), poly-to (ethylene naphthalate) (PEN), polymethylmethacrylate (PMMA), polyethersulfone (PES) or polyolefin (PO).When substrate was used in the transmissive viewing screen, the screen that is assembled in the display must be a self-supporting, therefore expected that substrate 101 is that thickness is 0.2mm or transparent material bigger and that have rigidity.

Light diffusion sheet 102 is to obtain by the aforementioned method that is used to produce light diffusion sheet, and the light that passes substrate 101 is carried out scattering to obtain scattered light.The beholder can see image true to nature by the reflected light of observing scattering.

For example, with the transmissive viewing screen of present embodiment with use the transmissive viewing screen of existing light diffusion sheet (high-high brightness on normal direction and scattering properties be symmetrical) placed side by side with respect to the high-high brightness axle, image light projects on each screen from rear side, observes image from the front side of screen.The result, in the display of the transmissive viewing screen that uses prior art, become clear and the lower part dimness of image in the top of image, yet, in the display of the transmissive viewing screen that uses present embodiment, can obtain to have the bright image of the high brightness that spreads all over whole screen.

The scattering properties preferably surface configuration of each the locational light diffusion sheet 102 by regulating screen is controlled, so that observed comprehensive (collective) Luminance Distribution of beholder all is uniform on whole screen.In order to realize this effect, for example, the axle offset of brightness peak is preferably towards the center section of screen.Specifically, with regard to the comprehensive scattering properties on the whole screen, scattering properties on whole marginal portions of screen preferably has such feature: the brightness peak of the light of institute's transmission is along angled towards the direction of the center section of screen, and this angle increases on the direction of marginal portion continuously at the center section from screen.

The transmissive viewing screen 100 of present embodiment is by on the surface that light diffusion sheet 102 is stacked in substrate 101 (comprise, for example, PET film) and produce.

The purposes of the light diffusion sheet of present embodiment is not limited to projection type display, but need this light diffusion sheet can be applied to the various field at control visual angle, such as display and luminaire.For example, when because the restriction of light source mounting condition causes light source can not be arranged on front side or rear side the time, use the light diffusion sheet of producing according to present embodiment can make light-ray condensing on the direction of expectation.In addition, in the application of luminaire, be arranged on the corner in room, just can illuminate the center section in room, realized illuminating effect by the light fixture that will have the light diffusion sheet of producing according to present embodiment.

Further introduce the present invention now with reference to the following examples.The following examples only are examples, and the present invention is not limited to the following examples.

(embodiment 1)

Produce under the following conditions and duplicate the mould that light diffusion sheet is used.

(1) mould host material: aluminium flake (X:200mm * Y:100mm)

(2) sandblast condition

Sand-blasting machine (model: SGF-4 (A); By Fuji Manufacturing Co., Ltd. production and selling)

Abrasive material: aluminium oxide (#180; Mean grain size: 76 μ m)

Distance between spray gun and the mould host material: 50mm

Angle between spray gun and the mould host material: 8 °

Compressed air pressure: 0.5MPa

Abrasive substance is to the injection conditions on mould host material surface: the condition shown in Fig. 1

The spray gun condition of scanning: along directions X with the spacing of 5mm and along the Y scanning direction, as shown in Figure 4.

The surface state of the mould that obtains provides in Fig. 7.We have seen a kind of like this state: exist the difference on the surface roughness between vertical and horizontal (X-direction and Y direction), and the distortion on the X-direction (pit) shape is than the length on the Y direction.

Below, in Fig. 8, provided the measurement result of the surfaceness of mould.The spacing P of surfaceness on X-direction _xThe spacing P of specific surface roughness on Y direction _YLong.Mean roughness (roughness space) Sm at interval is: X-direction: S=0.14; Y direction: S=0.08.

(embodiment 2)

Below, by the compacting of the mould among the embodiment 1 transparent resin (PET-G film, DIAFIX; By Mitsubishi Plastics, Inc. production and selling) produces light diffusion sheet.

Make the light diffusion sheet obtained can transmission from the collimated light beam at this sheet back side, to measure the scattering angle of the transmitted ray that sends from this sheet front side.The result provides in Fig. 9.

This light diffusion sheet shows such scattering angle: the scattering angle on laterally (X-direction) is different from the scattering angle on vertically (Y direction), and the brightness half-peak breadth on the X-direction is 18 °, and the brightness half-peak breadth on the Y direction is 45 °.

In the Luminance Distribution on X-direction (Fig. 9 (a)), brightness peak A axle offset perpendicular to the angle on the direction of light diffusion sheet (0 °).This meets according to the anisotropy of the scattering properties of present embodiment (axle offset).

(embodiment 3)

For determine between spray gun and the mould host material angle (spray angle) and scattering properties respectively to the relation between the property (axle offset angle) also, under condition substantially the same manner as Example 1, produced and duplicated the mould that light diffusion sheet is used, just from 2-90 ° of angle (spray angle) that has progressively changed between spray gun and the mould host material.Then, under the condition identical, use these moulds to produce a plurality of light diffusion sheets respectively with embodiment 2, and make light diffusion sheet that each obtained can transmission from the collimated light beam at this sheet back side, to measure the Luminance Distribution of transmitted light on X-direction of sending from this sheet front side.

From resulting Luminance Distribution, determined the relation between the anisotropy (axle offset angle) of spray angle and scattering properties.The result below table 1 and Figure 10 in provide.Can realize along the injection direction (X among Fig. 1 by adjusting spray angle ₁The axle offset of predetermined angular direction).

[table 1]

Spray angle (°)	Anisotropy (axle offset angle) (°)
Spray angle (°)	Anisotropy (axle offset angle) (°)	2	9.5
10	4.8	2	9.5
10	4.8	20	3.7
30	2.5	20	3.7
30	2.5	40	1.8
50	1.1	40	1.8

60	0.8
60	0.8	70	0.05
80	0	70	0.05
80	0	90	0

(embodiment 4)

Below, use the following application composition H that is used for optical thin film to produce reflective viewing screen with the application composition L that is used for optical thin film.

(1) is used for the application composition H of optical thin film

Fine particle: TiO ₂Fine particle is (by Ishihara Sangyo Kaisha Ltd. production and selling; Mean grain size: about 20nm; Refractive index: 2.48)

100 weight portions (2.02 weight %)

Spreading agent: comprise SO ₃The molecule of Na group (weight-average molecular weight: 1000; SO ₃Na radical concentration: 2 * 10 ^-3Mol/g)

20 weight portions (0.40 weight %)

Cementing agent: the potpourri of six acrylic acid dipentaerythritol ester and five acrylic acid dipentaerythritol ester (UV cured resin, trade name: DPHA; By Nipppon Kayaku Co., Ltd. production and selling)

30 weight portions (0.61 weight %)

Organic solvent: methyl isobutyl ketone (MIBK)

4800 weight portions (96.97 weight %)

At first, according to predetermined close separately fine particle, spreading agent and organic solvent are mixed, and disperseed, to obtain TiO by paint mixer ₂The fine particle dispersion liquid.Then, cementing agent is joined in the dispersion liquid, and stir, with preparation application composition H by stirrer.

(2) be used for the application composition L of optical thin film

Polymkeric substance (trade name: CYTOP with the perfluoro butenyl group vinyl ether that is positioned at terminal carboxylic group; By Asahi Glass Co., Ltd. production and selling)

(3) method of production reflective viewing screen

(S11) adopt dipping method that application composition H is applied on the two sides of transparency carrier.

(S12) with the film of 80 ℃ temperature oven dry application composition H, then by ultraviolet light (UV) (1000mJ/cm ²) irradiation is cured, with the optical thin film H of the refractive index that forms the thickness have 780nm separately and 1.94.

(S13) then, adopt infusion process that application composition L is applied on each high index of refraction optical thin film H.

(S14) with the film of 90 ℃ temperature oven dry application composition L, with the optical thin film L of the refractive index that forms the thickness that has 1240nm separately and 1.34.

(S15) under the condition identical application composition H is being applied on each optical thin film L with step S11.

(S16) film of formation application composition H under the condition identical with step S12, optical thin film H with the refractive index that forms the thickness have 780nm separately and 1.94, so just obtained comprising separately three layers optical multilayer, promptly, optical thin film H/ optical thin film L/ optical thin film H is arranged on each surface, in other words, on transparency carrier, there are six layers altogether.

(S17) by bond layer the light diffusion sheet among the embodiment 3 is stacked on the surface of one of above-mentioned optical multilayer.

(S18) adopt spin-coating method the black application composition to be applied on another surface of optical multilayer,, so just obtained reflective viewing screen to form the black light absorption layer.

Image light is projected on the resulting reflective viewing screen, observe image with front side from this screen.As a result, can see having evenly and the image of high brightness, prove the reflected image photocontrol must have been pointed to specific visual field in certain location.

(embodiment 5)

(1) mould host material: aluminium flake (X:200mm * Y:100mm)

(2) sandblast condition

Abrasive material: aluminium oxide (#220)

Distance between spray gun and the mould host material: 50mm

Angle between spray gun and the mould host material: 10 °

Compressed air pressure: 0.5MPa

The surface state of the mould that obtains provides in Figure 11.We have seen a kind of like this state: exist the difference on the surface roughness between vertical and horizontal (X-direction and Y direction), and the distortion on the X-direction (pit) shape is than the length on the Y direction.

Below, in Figure 12, provided the measurement result of the surfaceness of the mould that use contact pilotage type (stylus-type) profile meter ET4000A (by Kabushiki-kaisha Kosaka Laboratory production and selling) records.The spacing P of surfaceness on X-direction _xThe spacing P of specific surface roughness on Y direction _YLong.Average uneven gap Sm is: X-direction: S=90 μ m; Y direction: S=45 μ m.In addition, find that also the shape of the sloping portion on the Y direction is symmetrical, but the shape of the sloping portion on X-direction is asymmetric.Provided among Figure 13 based on the X of the trickle surface cell of the cross sectional shape among Figure 12 and the histogram at the pitch angle on the Y direction.Also find, the distribution at the pitch angle in the cross section on the directions X is symmetrical like this: it approaches Gaussian distribution, but being distributed on the occasion of a side and negative value one side of the pitch angle in the cross section on the Y direction all has two peak values, and the shape of this distribution is asymmetric (not being Gaussian distribution).

Below, prepared PET film (thickness: 100 μ m) as substrate with the width that is enough to form large scale light diffusion sheet with high light transmission.Then, with refractive index is that 1.53 urethanes acryl resin (urethane acrylic resin) is applied on the mould, then when preventing that resin from comprising bubble, with thickness is that the PET film of 100 μ m covers it, by rubber rollers it is pressurizeed then and adjust the pressure of rubber rollers simultaneously, so that the thickness of resin becomes evenly and is 50 μ m.Subsequently, from PET film one side light summation is the 1000mJ ultraviolet light irradiation resin of (this light summation is enough to polymerization and solidifies this resin), remove from mould together with substrate then, thereby the surface configuration of mould has been delivered on the resin, so just produced light diffusion sheet.

Scattering power for the light diffusion sheet of checking such production, the aluminium reflector plate is stacked on the back side of the light diffusion sheet that is obtained, produced reflective viewing screen, and use goniophotometer (by OPTECCO., LTD. production and selling) to the front surface radiation collimation light beam of this screen, change simultaneously on the directions X and the Y direction on angle, to measure the intensity of reflected light cross-sectional distribution.The result provides in Figure 14.

Angle on the directions X (half-peak breadth) (reflection strength is half of maximum intensity herein) is 25 °, and on the Y direction is 37 °.The surface configuration that reflects the mould shown in Figure 12 and Figure 13, high-high brightness angle on the Y direction is 0 °, and therefore scattering properties is symmetrical, and the high-high brightness angle on the directions X is 2 °, in other words, high-high brightness is on the direction of off-normal direction (with respect to the normal direction of the first type surface of light diffusion sheet) certain angle, scattered light intensity is that the ratio between the angle of a half is 1.1: 1, and therefore asymmetric with respect to high-high brightness axle (pointing to the axle of high-high brightness peak value from initial point), show that scattering has taken place more rays on the direction of high-high brightness axle.

Then, the aluminium reflector plate is stacked in the back side of the light diffusion sheet (high-high brightness be on the normal direction and scattering properties with respect to the high-high brightness rotational symmetry) of prior art, to be formed for the reflective viewing screen of comparison.The reflective viewing screen of this screen and present embodiment is placed side by side, and image light projects on each screen, observes image from the front side of screen.As a result, be used for the screen of comparison, the image on the screen center section bright, and the image dimness on the marginal portion.On the contrary, in the reflective viewing screen of present embodiment, can obtain to have the bright image of high brightness.In addition, by reflective viewing screen is placed upside down, according to the reflective viewing screen of present embodiment can be used at a certain angle the projection downwards forward carried out from the projector that is fixed on the ceiling and the projection that makes progress forward carried out from the projector that is placed on the desk at a certain angle in the middle of.

(embodiment 6)

With refractive index is that 1.53 urethanes acryl resin is applied on the mould, and this mould is the same mould that is used for duplicating the light diffusion sheet of embodiment 5.Subsequently, cover this mould with the PET film.The PET film has the thickness of 100 μ m and the high permeability in the purple light zone, and the one side has been carried out easy bonding processing as supporting component.Mould is to cover the PET film in such a way: the opposite side on PET film surface (not carrying out that side of easy bonding processing) is facing to die surface, prevent that simultaneously resin from comprising bubble, by rubber rollers it is pressurizeed then and adjust the pressure of rubber rollers simultaneously, so that the thickness of resin becomes evenly and is 100 μ m.Subsequently, be the 1000mJ ultraviolet light irradiation resin of (this light summation is enough to polymerization and solidifies this resin) from PET film side light summation, to form resin sheet.Afterwards, take off resin sheet from mould removing supporting component (PET film), thereby finished duplicating of light diffusion sheet, the surface structure of mould has been delivered on this light diffusion sheet.

Scattering power for the light diffusion sheet of checking such production, the aluminium reflector plate is stacked on the back side of the light diffusion sheet that is obtained, produced reflective viewing screen, and use goniophotometer (by OPTECCO., LTD. production and selling) to the front surface radiation collimation light beam of this screen, change simultaneously on the directions X and the Y direction on the angle of light degree, to measure the intensity of reflected light cross-sectional distribution.

As a result, the angle on the directions X (half-peak breadth) (reflection strength is half of maximum intensity herein) is 25 °, and on the Y direction is 37 °.High-high brightness angle on the directions X is 2 °, and in other words, high-high brightness tilts to normal direction (with respect to the normal direction of the first type surface of light diffusion sheet).Therefore, according to present embodiment, obtained the performance similar to embodiment 5.And, according to present embodiment, when image light projects on the screen and monitors, can obtain to have the bright image of high brightness near screen front with embodiment 5 similarly.And, according to present embodiment, can suitably adjust reflective viewing screen by the installation direction of putting upside down the rotary reflection screen under the situation of two kinds of installation environments, these two kinds of installation environments comprise: be tilted to down the situation of projection and be tilted to the situation of projection when projector is placed on the ceiling when projector is placed on the desk.

(embodiment 7)

Produce light diffusion sheet according to following method.

(S21) be that 1.53 urethanes acryl resin is applied on the mould of making among the embodiment 5 with refractive index, then when preventing that resin from comprising bubble, with thickness is that the PET film of 100 μ m covers it, by rubber rollers it is pressurizeed then and adjust the pressure of rubber rollers simultaneously, so that the thickness of resin becomes evenly and is 50 μ m.Subsequently, from PET film one side light summation is the 1000mJ ultraviolet light irradiation resin of (this light summation is enough to polymerization and solidifies this resin), remove from mould together with substrate then, thereby the surface configuration of mould has been delivered on the resin, so just produced light diffusion sheet A.

(S22) in addition, with refractive index is that 1.38 perfluoroalkyl acrylate resin is applied on the same mould, being used in the light diffusion sheet A that produces in the above-mentioned steps then covers it, by rubber rollers it is pressurizeed then and adjust the pressure of rubber rollers simultaneously, so that the thickness of resin becomes evenly and is 30 μ m.Subsequently, be the 1000mJ ultraviolet light irradiation resin of (this light summation is enough to polymerization and solidifies this resin) from PET film side light summation, remove from mould together with substrate then, thereby the surface configuration of mould has been delivered on the resin.

(S23) in addition, repeat step S21 and S22, comprise four layers light diffusion sheet with formation, these four layers have 1.53,1.38,1.53 and 1.38 refractive index respectively and begin arrangement from PET film side in this order.

Scattering power for the light diffusion sheet of checking such production, the aluminium reflector plate is stacked on the back side of the light diffusion sheet that is obtained, and use goniophotometer (by OPTEC CO., LTD. production and selling) to the front surface radiation collimation light beam of this light diffusion sheet, change simultaneously on the directions X and the Y direction on angle, to measure the intensity of reflected light cross-sectional distribution.The result provides in Figure 15.

High-high brightness angle on the Y direction is 0 °, and therefore scattering properties is symmetrical, and the high-high brightness angle on the directions X is 2.5 °, in other words, high-high brightness is on the direction of off-normal direction certain angle, scattered light intensity is that the ratio between the angle of a half is 1.2: 1, and therefore asymmetric with respect to the high-high brightness axle, shows that scattering has taken place more rays on the direction of high-high brightness axle.

(embodiment 8)

Without aluminium flat sheet, under the condition identical, be that the aluminium roller of 20cm carries out blasting treatment to diameter with embodiment 1, and using roller is that 1.53 urethanes acryl resin is applied on the mould to roller (roll-to-roll) continuous film formation machine with refractive index, the while cladding thickness is that the polyethylene terephthalate of 100 μ m covers it, from polyethylene terephthalate side light summation is the 1000mJ ultraviolet light irradiation resin of (this light summation is enough to solidify this resin), then it is taken off from mould, to form light diffusion sheet.

Scattering power for the light diffusion sheet of checking such production, the aluminium reflector plate is stacked on the back side of the light diffusion sheet that is obtained, and use goniophotometer (by OPTEC CO., LTD. production and selling) to the front surface radiation collimation light beam of this light diffusion sheet, change simultaneously on the directions X and the Y direction on angle, to measure the intensity of reflected light cross-sectional distribution.The result provides in Figure 16.High-high brightness angle on the Y direction is 0 °, and therefore scattering properties is symmetrical, and the high-high brightness angle on the directions X is 3.8 °, in other words, high-high brightness is on the direction of off-normal direction certain angle, scattered light intensity is that the ratio between the angle of a half is 1.3: 1, and therefore asymmetric with respect to the high-high brightness axle, shows that scattering has taken place more rays on the direction of high-high brightness axle.

(embodiment 9)

Use light diffusion sheet among the

embodiment

5 and 8 as light diffusion sheet, and the light diffusion sheet of present embodiment has 1.5 and 2.0 degree of asymmetry with respect to the high-high brightness axle respectively, the aluminium reflector plate is stacked in the back side of each light diffusion sheet, form reflective viewing screen.In addition, use light diffusion sheet (trade name: 125PW with isotropic scatterning characteristic; By Kabushiki-Kaisha Kimoto production and selling) and have the light diffusion sheet (trade name: LSD60 ★ 25 of symmetry, anisotropic scattering characteristic; By the POC production and selling), equally the aluminium reflector plate is stacked in the back side of each light diffusion sheet, be formed for the reflective viewing screen of comparison.

Use these reflective viewing screens, in the middle of the projection of carrying out at a certain angle from the projector that is fixed on the ceiling downwards forward, at each image measurement on the upper, middle and lower each several part of screen gain (brightness is with respect to the brightness of using desirable scatterer to obtain), and provide in result's table 2 below.In this case, the asymmetric light diffusion sheet among the embodiment is set, so that the one side with big optical convergence ability is towards last.Measurement is to carry out under such condition: projector is positioned on the position of screen 5m, makes direct reflection appear at the central authorities of screen.

When using the asymmetric light diffusion sheet of present embodiment, the difference between the gain at screen middle part and the gain of screen top and/or bottom is littler than comparative example 9-2's, and this shows that brightness uniformity is improved.This effect is especially remarkable in the large scale screen.

To be that the transparent resin substrate of the polymethylmethacrylate of 2mm couples together with comprising thickness according to the light diffusion sheet of present embodiment, so that this sheet has the rigidity that forms transmissive viewing screen.In the display that uses this transmissive viewing screen, we find that the same with reflective viewing screen, the homogeneity of brightness also is improved.

(embodiment 10)

The surface of aluminium flake is handled by sandblast according to the mode identical, duplicate the mould of light diffusion sheet with formation, and use this mould to form light diffusion sheet by ultraviolet curable resin with embodiment 1.In this case, be used under the sandblast condition of production mould, particle diameter, power and the spray angle of abrasive substance changed, so that the surfaceness of mould spacing on directions X becomes 90-420 μ m.

The light diffusion sheet of being produced is used in the image display, and observes image being suitable for observing on the distance of image light, to estimate identifiability.Identifiability is according to following three standard evaluations: obtain clear and distinct image (label: zero); Resolution is satisfactory, but the dazzling (label: △) of screen; With differentiate rate variance, and dazzling significantly (label: *).

Provide in result's table 3 below.Under the situation of observing with the little distance that gets the spacing of the roughness that can identify light diffusion sheet, dazzling sense is very strong, and not fogging Chu.Especially when the brightness of image light is high, dazzle the eyes sense quite obvious.

[table 3]

The spacing of surfaceness	Chip size	Viewing distance	Identifiability
The spacing of surfaceness	Chip size	Viewing distance	Identifiability	90μm	30 inches	60cm	○
90μm	40 inches	120cm	○	90μm	30 inches	60cm	○
90μm	40 inches	120cm	○	180μm	30 inches	60cm	△
180μm	40 inches	120cm	○	180μm	30 inches	60cm	△
180μm	40 inches	120cm	○	180μm	60 inches	200cm	○
260μm	30 inches	60cm	×	180μm	60 inches	200cm	○

260μm	40 inches	120cm	△
260μm	40 inches	120cm	△	260μm	60 inches	200cm	○
420μm	40 inches	120cm	×	260μm	60 inches	200cm	○
420μm	40 inches	120cm	×	420μm	60 inches	200cm	△
420μm	60 inches	500cm	○	420μm	60 inches	200cm	△

Relation between eyesight and beholder's the resolution is by following formulae express:

Resolution (dpi)=2.54 * 3438 * (eyesight)/(viewing distance) (cm)

Specifically, when observing image on the distance of beholder with eyesight of 1.0 at 60cm, this beholder can discern 146dpi (spacing: 173 μ m), and, when observing image on the distance of this beholder at 200cm, this beholder can discern 44dpi (spacing: 577 μ m).Therefore, suitable surfaceness basis leaves the viewing distance of employed light diffusion sheet and user's eyesight changes, and but, considers to observe on the distance of 100-200cm, and expectation surfaceness (uneven spacing) is 300 μ m or littler.

Those skilled in the art is to be understood that, in the limit within the scope that is in appended claims or its content of equal value, according to designing requirement and other factor, various modifications, assembled scheme, recombinant scheme and alternative can appear.

Claims

1. a light diffusion sheet comprises the light scattering face with such scattering properties, wherein vertically go up scattering properties and be different from transversely scattering properties, wherein:

This light diffusion sheet has the axle offset of the high-high brightness on vertical and horizontal one or both of, and the axle offset of high-high brightness is detected at the angle-dependence that is transmitted into the photo measure brightness of the light of scattering from scattering surface on the scattering surface with 0 ° incident angle the time.

2. a light diffusion sheet comprises the light scattering face with such scattering properties, wherein vertically go up scattering properties and be different from transversely scattering properties, wherein:

At the angle-dependence that is transmitted into the light brightness of the light of scattering from scattering surface on the scattering surface with 0 ° incident angle is to measure with such method: vertical and horizontal any one or the two on, the high-high brightness axle is angled with respect to the normal direction of the first type surface of light diffusion sheet, wherein

Luminance Distribution is asymmetric with respect to the high-high brightness axle.

3. a light diffusion sheet comprises the light scattering face with such scattering properties, wherein vertically go up scattering properties and be different from transversely scattering properties, wherein:

The light scattering mask has trickle surface cell, and these trickle surface cells have the structure that rises or descend, and is asymmetric with respect to the normal direction of the first type surface of light diffusion sheet.

4. the light diffusion sheet of claim 3, wherein:

It is 300 μ m or littler uneven structure that the light scattering mask has spacing.

5. the light diffusion sheet of claim 1 comprises the light scattering face that obtains by the uneven structure transmission by the surface of blasting treatment, wherein:

Sandblast is to carry out with the abrasive substance spray angle less than 90 °.

6. the light diffusion sheet of claim 2 comprises the light scattering face that obtains by the uneven structure transmission by the surface of blasting treatment, wherein:

7. the light diffusion sheet of claim 3 comprises the light scattering face that obtains by the uneven structure transmission by the surface of blasting treatment, wherein:

8. screen, it comprises:

Light diffusion sheet, this light diffusion sheet comprises the light scattering face with such scattering properties, wherein vertically go up scattering properties and be different from transversely scattering properties, and this light diffusion sheet has the axle offset of the high-high brightness on vertical and horizontal one or both of, and this axle offset is by at the angle-dependence that is transmitted into the photo measure brightness of the light of scattering from the scattering surface on the scattering surface with 0 ° incident angle and detected.

9. the screen of claim 8, wherein:

Axle offset is on the direction at screen middle part.

10. screen, it comprises:

The light diffusion sheet of claim 5; With

Be formed on this light diffusion sheet, the reflection horizon on the opposite side with light scattering face.

11. a screen, it comprises:

The light diffusion sheet of claim 6; With

12. a screen, it comprises:

The light diffusion sheet of claim 7; With

13. a screen, it comprises:

The light diffusion sheet of claim 5, wherein

This light diffusion sheet transmission is from the light of a side opposite with light scattering face projection, and scattering and send the light of the light scattering face of passing.

14. a screen, it comprises:

The light diffusion sheet of claim 6, wherein

15. a screen, it comprises:

The light diffusion sheet of claim 7, wherein

16. a screen, it comprises:

The light diffusion sheet of claim 1; With

17. a screen, it comprises:

The light diffusion sheet of claim 1, wherein

18. a screen, it comprises:

The light diffusion sheet of claim 2; With

19. a screen, it comprises:

The light diffusion sheet of claim 2, wherein

20. a screen, it comprises:

The light diffusion sheet of claim 3; With

21. a screen, it comprises:

The light diffusion sheet of claim 3, wherein

This light diffusion sheet transmission is from the light of the side projection opposite with light scattering face, and scattering and the light of launching the light scattering face that passes.

22. a screen, it comprises:

The light diffusion sheet of claim 4; With

23. a screen, it comprises:

The light diffusion sheet of claim 4, wherein