JP2006301589A - Light diffusing member, manufacturing method thereof and transmission type screen - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light diffusing member capable of easily obtaining a transmission type screen which has good contrast of a video images and excellent viewing angle characteristic. <P>SOLUTION: The light diffusing member 30 comprises a sheet-like lenticular lens part 10 in which a large number of convex cylindrical lenses 5 are formed on one side surface in the thickness direction with a pitch Pc and a light shielding pattern 20 composed of a large number of light shielding layers 15 which are formed on the other side surface 10a in the thickness direction on the lenticular lens part 10. Therein, an outer surface 15a of the light shielding layer is located on substantially the same plane with a region 10<SB>p</SB>on which a light shielding layer is not formed in the other side surface in the thickness direction and the light shielding layers are arranged outside an optical path of the light which is made incident on one side surface in parallel to the optical axis OA of the convex cylindrical lens and is emitted from the other side surface. Further, when the thickness of the light shielding layer is T, the width thereof is W and the refractive index of the convex cylindrical lens is n<SB>c</SB>, the following relation holds; 0<T<(P<SB>c</SB>-W)/[2×tan(sin<SP>-1</SP>(1/n<SB>t</SB>))]. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a light diffusing member, a method for manufacturing the same, and a transmissive screen configured using the light diffusing member. More specifically, a large number of convex cylindrical lenses are formed on one surface side in the thickness direction, and the thickness is increased. A light diffusing member of a type having a sheet-like lenticular lens portion whose other surface in the vertical direction is formed into a flat surface, and a light-shielding pattern formed on the other surface of the lenticular lens portion, and a method for manufacturing the same. The present invention also relates to a transmissive screen configured using the light diffusing member.

  Today, large-screen displays such as liquid crystal displays, projection displays, and plasma displays are prevalent in ordinary homes. Large screen displays are often purchased on the assumption that multiple people view the video (image), so that even when multiple people view the video (image), each person can enjoy high-quality video. High viewing angle characteristics are required. For this reason, in particular, in a rear projection display, a transmissive screen provided with a light diffusing member is used in order to improve the viewing angle characteristics in the horizontal direction (meaning the horizontal direction of the screen; the same applies hereinafter).

  Various light diffusing members have been proposed for use in transmissive screens. One of them is a large number of convex cylindrical lenses formed at a constant pitch on one surface in the thickness direction. A sheet-shaped lenticular lens portion whose other surface in the thickness direction is formed into a flat surface, and a light shielding layer formed by a plurality of light-shielding layers formed on the other surface of the lenticular lens portion so as to protrude from the surroundings. There is a type of light diffusing member provided with a pattern. As used herein, “convex cylindrical lens” means a cylindrical lens having a refractive surface formed into a convex surface.

  The light diffusing member of the above type can diffuse parallel light incident on the refractive surface of the convex cylindrical lens in parallel with the optical axis of the convex cylindrical lens in the arrangement direction of the convex cylindrical lenses. Therefore, by combining the light diffusion member of the above type and a Fresnel lens, it is possible to obtain a transmissive screen with good viewing angle characteristics.

  The Fresnel lens in this transmissive screen is placed on the image light source side of the light diffusing member in the projection optical system of the rear projection display, and converts the image light projected in the divergent light state into substantially parallel light. The light is then incident on the light diffusing member. Further, the light diffusing member is arranged in such a direction that the longitudinal direction of each convex cylindrical lens is a vertical direction (which means the vertical direction of the screen; the same applies hereinafter), and the refractive surface of each convex cylindrical lens is on the Fresnel lens side. Then, the substantially parallel image light emitted from the Fresnel lens is diffused in the arrangement direction of the convex cylindrical lenses. As a result, the horizontal viewing angle characteristic of the rear projection display is improved. The light shielding pattern prevents external light from being reflected on the transmissive screen and improves the contrast of the image.

For example, in Patent Document 1, in order to improve the horizontal viewing angle characteristics and the image contrast when a transmissive screen is configured using the above-described type of light diffusion member and a Fresnel lens, A transmissive screen is described in which the aperture ratio of the light shielding pattern in the diffusing member is selected within a specific range. The lenticular lens portion (lenticular lens sheet) constituting the transmission screen is formed by flattening the other surface in the thickness direction, and a plurality of light shielding layers are formed in stripes on the other surface. The light shielding pattern is formed.
Japanese Patent Laying-Open No. 2001-215622 (see claims and FIG. 4B)

  However, like the transmissive screen described in Patent Document 1, the other surface in the thickness direction of the lenticular lens portion (lenticular lens sheet) is a flat surface, and the light shielding pattern is formed so as to protrude on the flat surface. In a transmissive screen provided with a light diffusing member that prevents external light from being reflected, it is difficult to improve viewing angle characteristics while maintaining good image contrast.

  In particular, as in recent years, an MD (micro display) type rear projection television has a drawback that scintillation (glare) derived from the light source is likely to occur. In order to eliminate the scintillation, Fresnel lens sheets have been conventionally used. More diffusing agents are contained than the CRT type. However, since the light that has passed through the Fresnel lens sheet containing such a diffusing agent enters the lenticular lens sheet as parallel light with an increased diffusion component than before, the ratio of stray light in the lenticular lens sheet is higher than before. As a result, the generated stray light is emitted from an unspecified part of the lenticular lens sheet to the observer side, causing a decrease in resolution and a decrease in contrast. However, the conventional lenticular lens sheet formed so that the light-shielding pattern protrudes toward the viewer side has a problem that the stray light running in the lenticular lens sheet cannot be captured sufficiently.

  On the other hand, in order to prevent external light from being reflected on the transmissive screen using the light diffusing member, the thickness of each light shielding layer constituting the light shielding pattern is increased, or the width of the light shielding layer is increased. Although it is desirable to reduce the retroreflection of external light by any means of enlarging, as the thickness of the light shielding layer is increased or the width of the light shielding layer is increased, from the lenticular lens portion Among the emitted image light, image light having a large horizontal emission angle is blocked by the light shielding layer, and the viewing angle characteristics are deteriorated.

  The retroreflection of external light refers to the refractive surface of the convex cylindrical lens and the medium outside it (generally air) as it enters (propagates) into the lenticular lens from the opening of the light shielding pattern (between adjacent light shielding layers). This means that the external light totally reflected at the interface with the light exits from the opening part (between adjacent light-shielding layers) at a location different from that at the time of entering again to the outside of the lenticular lens part.

  The present invention has been made in view of the above circumstances, and a first object of the present invention is to provide a light diffusing member that makes it easy to obtain a transmissive screen with good image contrast and high viewing angle characteristics. It is to provide.

  A second object of the present invention is to provide a method for manufacturing a light diffusing member that makes it easy to obtain a transmissive screen with good image contrast and high viewing angle characteristics.

  A third object of the present invention is to provide a transmissive screen that can easily obtain an image with good image contrast and high viewing angle characteristics.

The light diffusing member according to the first aspect of the present invention that achieves the first object is a sheet-like structure in which a large number of convex cylindrical lenses are formed in parallel at a constant pitch _Pc on one surface side in the thickness direction. A light diffusing member comprising: a lenticular lens portion; and a light shielding pattern including a plurality of light shielding layers arranged in a stripe pattern on the other surface in the thickness direction of the lenticular lens portion, wherein the outer surface of the light shielding layer is The thickness of the other surface in the thickness direction is substantially the same plane as the region where the light shielding layer is not formed, and the light shielding layer is parallel to the optical axis of the convex cylindrical lens. The convex cylindrical lens is disposed outside the optical path of the light incident on one surface in the vertical direction and emitted from the other surface, the thickness of the light shielding layer is T, the width of the light shielding layer is W, and the refractive index and _{n c} of When the, characterized in that the following formula (I) is satisfied (hereinafter, this light diffusing member is sometimes referred to as "light diffusing member IA".).

The light diffusing member according to the second aspect of the present invention is an aspect in which the convex cylindrical lens constituting the first aspect is replaced with a so-called fly-eye lens, and a large number of units are provided on one surface side in the thickness direction. A sheet-like lens portion in which convex lenses are formed in a vertical and horizontal pitch P _V and a horizontal pitch P _H (hereinafter, sometimes referred to as “microlens array portion” or “fly-eye lens portion”). And a light diffusing member comprising a light shielding layer arranged in a matrix on the other surface in the thickness direction of the lens portion, wherein the outer surface of the light shielding layer is the other in the thickness direction. And the light shielding layer is incident on one surface in the thickness direction parallel to the optical axis of the unit convex lens. From the other side Is arranged outside the optical path of the morphism light, the the thickness of the light shielding layer is T, the vertical width W _V of the light-shielding layer, the width and W _H, when the refractive index of the unit lens has a n _c In addition, the following formulas (II) and (III) are satisfied (hereinafter, this light diffusion member may be referred to as “light diffusion member IB”).

Here, the “refractive index” means a refractive index when the wavelength of the measurement light is 588 nm. The pitch P _c , the thickness T and the width W referred to in the first aspect, and the pitch P _H , P _V , the thickness T and the widths W _H , W _V referred to in the second aspect may be the same. Absent.

  According to the light diffusing members IA and IB, since the outer surface of the light shielding layer is on the same plane as the region where the light shielding layer is not formed, the light shielding layer is in the lenticular lens portion or the microlens array portion. It has a shape that protrudes. The light diffusing member of the present invention having such a lenticular lens portion or microlens array portion, and a Fresnel containing many diffusing agents, such as a Fresnel lens sheet that is preferably used in recent MD type rear projection televisions. When used in combination with a lens sheet, it occurred even if the proportion of parallel light that increased the diffusion component that passed through the Fresnel lens sheet entered the lenticular lens part or microlens array part and became stray light more than before. The stray light has an advantage that it can be easily captured by the light shielding layer having a shape protruding into the lenticular lens portion or the microlens array portion. As a result, stray light emitted from an unspecified portion of the light diffusing members IA and IB of the present invention to the viewer can be reduced, and problems such as a reduction in resolution and a reduction in contrast can be eliminated as much as possible.

  In addition, since the light shielding layer protrudes into the lenticular lens portion or the micro lens array portion, the light that is about to pass through the lenticular lens portion or the micro lens array portion is not formed with the light shielding layer. Even if stray light is generated by reflection at the exit interface of the light, such stray light has an advantage that it can be easily captured by the light-shielding layer having a form protruding into the lenticular lens portion or the microlens array portion. As a result, stray light emitted from an unspecified portion of the light diffusing members IA and IB of the present invention to the viewer can be reduced, and problems such as a reduction in resolution and a reduction in contrast can be eliminated as much as possible.

The light diffusing member IA according to the first aspect of the present invention to achieve the above-mentioned operational effects, shielding layer, and the pitch P _c of the convex cylindrical lenses, and the width W of the light-shielding layer, and the refractive index n _c of the convex cylindrical lenses In the light diffusing member IB according to the second aspect of the present invention, which is formed with a thickness T satisfying the above-described relationship, the light shielding layer includes the pitches P _H and P _{V of the} unit convex lenses, and the light shielding layer. width W _H of _the W _V, because it is formed to a thickness T satisfying the relationship between the refractive index n _c of the unit convex lens, a transmission type screen configured by using the light diffusing member IA, the IB is Even if the thickness of the light shielding layer is relatively large, the image light to be emitted from the lenticular lens portion or the microlens array portion is prevented from being blocked by the light shielding layer. Furthermore, since the thickness of the light shielding layer can be made relatively thick, it is easy to prevent retroreflection of light (external light) incident from the other surface in the thickness direction in the lenticular lens part or microlens array part, In particular, it is easy to prevent the generation of retroreflected light having a relatively small emission angle. By selecting the thickness of the light-shielding layer so that the above formula (I) or formula (II) (III) is satisfied, the lenticular lens portion is parallel to the optical axis of the convex cylindrical lens or unit convex lens from the one surface side. Or it becomes easy to arrange | position a light-shielding part out of the optical path of the light which injects into a micro lens array part, and is radiate | emitted from the said surface, without totally reflecting on said other surface. For these reasons, according to the light diffusing members IA and IB, it is easy to obtain a transmissive screen with good image contrast and high viewing angle characteristics.

  In the light diffusing members IA and IB of the present invention, the convex cylindrical lens or unit convex lens is an aspherical lens in which the condensing point near the optical axis is farther from the condensing point at the end in the width direction. It is preferable that the condensing point at the end in the width direction is on the other surface in the thickness direction (hereinafter, this light diffusion member may be referred to as “light diffusion member IIA, IIB”).

  According to the light diffusing members IIA and IIB, a condensing point of light incident near the optical axis of the convex cylindrical lens or unit convex lens and a condensing point of light incident on the end of the convex cylindrical lens or unit convex lens in the width direction Therefore, in the transmissive screen configured using the light diffusing members IIA and IIB, the luminance particularly near the front of the screen is increased. As a result, it becomes easier to obtain a transmission screen with high image contrast and high viewing angle characteristics.

  The light diffusing member IA, IB to IIA, IIB of the present invention further includes a light diffusing layer that covers an outer surface of the light shielding layer and a region of the other surface where the light shielding layer is not formed ( Hereinafter, this light diffusing member is sometimes referred to as “light diffusing member IIIA, IIIB”).

  According to the light diffusing members IIIA and IIIB, since the light diffusing layer is provided, it is possible to obtain a transmissive screen with good image contrast and high horizontal and vertical viewing angle characteristics. Becomes easier.

  Further, in the light diffusing members IIIA and IIIB of the present invention, the degree of vertical light diffusion in the light diffusing layer is greater than the degree of vertical light diffusion until reaching the light diffusing layer. (Hereinafter, this light diffusing member may be referred to as “light diffusing member IVA, IVB”). Here, the “vertical direction” in the light diffusing members IVA and IVB means a direction corresponding to the vertical direction (up and down direction of the screen) on the transmission screen configured using the light diffusing members IVA and IVB. To do.

  According to the light diffusing members IVA and IVB of the present invention, since the light diffusion in the light diffusion layer and the light diffusion in the lenticular lens part or the microlens array part have the above relationship, the viewing angle characteristics in the vertical direction Even if a light diffusing material is added to the lenticular lens section or microlens array section to improve the image quality, it is easy to suppress the occurrence of scintillation. As a result, the image contrast is good and the viewing angles in the horizontal and vertical directions are good. It becomes easier to obtain a transmission screen having both high characteristics.

  The light diffusing member IA, IB to IVA, IVB of the present invention further includes at least one of an antistatic layer, an antireflection layer, and an antiglare layer as the outermost component on the other surface side (hereinafter, This light diffusing member is sometimes referred to as “light diffusing member VA, VB”).

  In the light diffusing members IVA and IVB, when the antistatic layer is provided, the adhesion of dust to the surface is suppressed, and as a result, it becomes easy to keep the optical characteristics in a good state even if the frequency of cleaning is lowered. Therefore, it becomes easy to obtain a transmission screen with good image contrast and high viewing angle characteristics and practicality. Further, in the case of having an antireflection layer, the reflection of external light can be suppressed by this antireflection layer, and as a result, it is possible to suppress the reflected light from being superimposed on the diffused light by the light diffusing member VI. It becomes even easier to obtain a transmissive screen with good image contrast and high viewing angle characteristics. In addition, when the antiglare layer is provided, reflection of external light can be suppressed by the antiglare layer, so that a transmissive screen having no external light reflection and high viewing angle characteristics can be obtained. It becomes easier.

  The manufacturing method of the light diffusing member according to the first aspect of the present invention that achieves the second object described above is the manufacturing method of any of the above-described light diffusing members IA to VA of the present invention. A lenticular lens sheet is prepared in which a number of convex cylindrical lenses are formed in parallel at a constant pitch on one surface side, and the other surface in the thickness direction is formed into a flat surface, and the other lenticular lens sheet A light shielding layer having a light shielding pattern to be formed using a photocurable or electron beam curable resin composition having a refractive index in a cured state substantially the same as the refractive index of the convex cylindrical lens. A transparent layer forming step of forming a transparent layer having a thickness equal to or greater than the thickness of the transparent layer, and selectively irradiating the transparent layer with light or an electron beam to emit light parallel to at least the optical axis of the convex cylindrical lens. one A selective curing step in which a region which becomes an optical path when being incident on the lenticular lens sheet from the other surface side is cured, and at least a region where the light shielding layer is to be formed is left uncured, and the selective curing A light-shielding material layer is disposed on the transparent layer that has undergone the process, and a load greater than the yield point in the uncured region of the transparent layer is applied to the light-shielding material layer and remains uncured. A light-shielding pattern forming step of selectively transferring the light-shielding material layer to the region and thereby forming a light-shielding pattern (hereinafter, this manufacturing method may be referred to as “manufacturing method A1”). .)

  Moreover, the manufacturing method of the light-diffusion member which concerns on the 2nd aspect of this invention is a manufacturing method in any one of the light-diffusion members IB-VB of this invention mentioned above, Comprising: Many one surface side of thickness direction is many. A microlens array sheet is prepared in which unit convex lenses are formed in parallel at regular pitches in the vertical and horizontal directions, and the other surface in the thickness direction is formed into a flat surface, and the other surface of the microlens array sheet is cured. Using a photocurable or electron beam curable resin composition having a refractive index under the same condition as the refractive index of the unit convex lens, the thickness of the light shielding layer in the light shielding pattern to be formed is greater than or equal to A transparent layer forming step of forming a transparent layer having a thickness, and selectively irradiating the transparent layer with light or an electron beam so that at least light parallel to the optical axis of the unit convex lens is emitted from the one surface side. Micro lens array sea A selective curing step in which a region that becomes an optical path when being incident on the substrate is cured, and at least a region in which the light shielding layer is to be formed is left uncured, and the transparent layer that has undergone the selective curing step A light-shielding material layer is disposed, and a load larger than the yield point of the uncured region in the transparent layer is applied to the light-shielding material layer to select the light-shielding material layer in the uncured region And a light shielding pattern forming step of forming a light shielding pattern thereby (referred to below as “manufacturing method B1”).

Here, “a photocurable or electron beam curable resin composition having a refractive index in a cured state substantially the same as that of a convex cylindrical lens” and “a refractive index in a cured state is a unit convex lens” "A photocurable or electron beam curable resin composition substantially the same as the refractive index of" is a photocurable (including ultraviolet curable. The same applies hereinafter) or electron beam curable resin composition is cured. the refractive index of a state under the n _r, convex cylindrical refractive index of the lens or the unit lens is taken as n _c, photocurable or electron beam difference between n _r and n _c is equal to or less than about 0.05 It means a curable resin composition.

  According to the manufacturing methods A1 and B1 of the present invention, since the lenticular lens sheet or the microlens array sheet in which the other surface in the thickness direction is formed into a flat surface as described above is used, the light diffusion member of the present invention described above is used. IA, IB to VA, and VB can be obtained relatively easily.

  Another method of manufacturing the light diffusing member of the present invention that achieves the second object described above is the method of manufacturing the light diffusing member IA, IB to VA, VB of the present invention described above, in the thickness direction. A lenticular lens in which a number of convex cylindrical lenses or unit convex lenses are formed in parallel at a constant pitch on one surface side of the lens, and a groove for forming a light shielding pattern is formed in a stripe shape on the other surface side in the thickness direction. A preparation step of preparing a member or a microlens array member, and a light shielding pattern forming step of forming a light shielding pattern by applying a light shielding material to the groove (hereinafter, this manufacturing method is referred to as “ It may also be referred to as “Production Methods A2, B2”.)

  According to the manufacturing methods A2 and B2, since the light shielding pattern can be formed by applying the light shielding material as described above, the light diffusion members IA, IB to VA, VB of the present invention described above are high. It becomes easy to obtain under productivity.

  The transmissive screen according to the first aspect of the present invention that achieves the third object described above includes any one of the light diffusing members IA to VA of the present invention described above and the refractive surface of the convex cylindrical lens in the light diffusing member. It has a Fresnel lens sheet arranged on the outside.

  In addition, the transmission screen according to the second aspect of the present invention includes a Fresnel lens sheet disposed on the outside of the refractive surface of the unit convex lens in the light diffusion member and any of the light diffusion members IB to VB of the present invention described above. It is characterized by having.

  According to these transmissive screens, since the image light can be diffused by the light diffusing member of the present invention described above after being converted into substantially parallel light by the Fresnel lens sheet, the viewing angle is maintained while maintaining good image contrast. It becomes easy to improve the characteristics.

  As described above, any of the light diffusing member, the method of manufacturing the light diffusing member, and the transmissive screen of the present invention makes it easy to obtain a transmissive screen with good image contrast and high viewing angle characteristics. Therefore, it becomes easy to provide a projection display with high display characteristics.

  In particular, when used in combination with a Fresnel lens sheet containing many diffusing agents, such as a Fresnel lens sheet preferably used in recent MD type rear projection televisions, stray light generated is generated in the lenticular lens part or in the microlens. Since it can be effectively captured by the light-shielding layer having a shape protruding into the array portion, stray light emitted from the unspecified portion of the light diffusing member I of the present invention to the observer side can be reduced, and the resolution can be reduced. The problem of reduction and contrast reduction can be eliminated as much as possible.

  Hereinafter, the light diffusing member, the method for manufacturing the light diffusing member, and the transmission screen according to the present invention will be described with reference to the drawings as appropriate.

(Light diffusing member; first form)
FIG. 1A is a cross-sectional view schematically showing the basic structure of the light diffusing member of the present invention. The illustrated light diffusing member 30 includes a lenticular lens unit 10 and a light shielding pattern 20 provided on the lenticular lens unit 10. Hereinafter, the basic structure and characteristics of the light diffusing member of the present invention will be described with reference to the light diffusing member 30.

The lenticular lens unit 10 is a sheet-like object in which a large number of convex cylindrical lenses 5 are formed in parallel to each other at a constant pitch _Pc on one surface side in the thickness direction. The other surface 10a in the thickness direction of the lenticular lens portion 10, the area where the respective light-shielding layer 15 constituting the light-shielding pattern 20 corresponding to the shape and size of the light shielding layer 15 shape and size of the recess 10 _d It is an uneven surface. The outer surfaces of the boundary regions 10 _p located between the adjacent recesses 10 _d are substantially on the same plane, and the outer surface is substantially the same as the outer surface 15 a of the light shielding layer described later. Are on the same plane.

In the case of using the light diffusing member 30 as a component of the transmissive screen, from the viewpoint of improving the resolution, it is preferable to select the pitch P _c of the in the range of about 1500～50Myuemu. Also, the moire from the viewpoint of preventing the matrix image source using a liquid crystal light valve, digital mirror device, it is further preferable to select the pitch P _c of the in the range of about 300～50Myuemu. Each convex cylindrical lens 5 is an aspherical lens in which the condensing point of the parallel light incident near the optical axis OA is farther than the condensing point of the parallel light incident on the end in the width direction. are preferred, and one focal point of the collimated light incident on the vicinity of the optical axis OA is in the thickness direction on the other surface 10a (on the outer surface of the boundary region 10 _p), the other surface 10a ( it is preferred that the outside than the outer surface) of the boundary region 10 _p. The maximum thickness of the lenticular lens portion 10 is 0.8 to 1.6 times the pitch _{P c,} preferably it is appropriately selected within the range of 1.0 to 1.4 times.

Such a lenticular lens portion 10 can be a single-layer structure composed of a single lenticular lens sheet as shown in FIG. 1A, or the other surface in the thickness direction is formed into a flat surface. The lenticular lens sheet and a transparent resin layer that is provided on the other surface of the lenticular lens sheet and that forms at least the boundary region _10p can also be used. Further, as in the lenticular lens portion 10A shown in FIG. 1B, a convex cylindrical lens group 5A composed of a large number of convex cylindrical lenses 5 is formed on one surface of the base film 1, and the other of the base film 1 is formed. A three-layer structure in which a plurality of transparent resin layers 7 to be the boundary region 10 _p (see FIG. 1A) are formed in a predetermined pattern on the surface of the surface. When the lenticular lens unit 10 has a two-layer or three-layer structure, it is preferable to suppress the physical interface between adjacent layers in the thickness direction from becoming an optical interface. It is preferable that the difference in refractive index of the layers is about 0.05 or less.

  Any lenticular lens portion having a single-layer structure or a laminated structure can be formed of a transparent resin having a refractive index of about 1.45 to 1.60, for example. The lenticular lens portion 10 having a single layer structure can be formed of, for example, an acrylic resin, a polycarbonate resin, a vinyl chloride resin, a styrene resin, a cellulose resin, a cycloolefin resin, an acrylic styrene copolymer resin, or the like. . Further, the lenticular lens sheet and the transparent resin layer in the lenticular lens portion having a two-layer structure, and the convex cylindrical lens group 5A and the transparent resin layer in the lenticular lens portion 10A having a three-layer structure are respectively urethane-based, epoxy-based, polyester-based, and the like. It can be formed of an ultraviolet curable resin. As the base film 1 in the lenticular lens portion 10A having a three-layer structure, a transparent film made of polyester, polycarbonate, acrylic, or the like can be used. If necessary, a small amount of a light diffusing material can be dispersed in the transparent resin.

Shielding pattern shown in FIG. 1 (a) 20, a large number light shielding layer 15, which are arranged in parallel stripes at a constant pitch P _s, the pitch P _s between the light shielding layer 15 adjacent the lenticular lens portion The pitch _Pc of the convex cylindrical lens 5 at 10 is the same value. These light shielding layers 15 are formed of a resin in which black pigments or black beads are dispersed, black ink, or the like, and have a strip shape or the like around the optical axis OA of each convex cylindrical lens 5 with the optical axis OA as an axis of symmetry. A linear light transmission portion is defined. The outer surface of the light transmission part is included in the outer surface of the boundary region 10 _p described above.

The outer surface 15a of the light-shielding layer 15 is located in an outer surface substantially coplanar perimeter 10 _p, these light-shielding layer 15, parallel to the optical axis OA on the refractive surface of each convex cylindrical lens 5 incident to being positioned outside the optical path of light emitted from the thickness direction of the other surface 10a (the outer surface of the boundary region 10 _p). The thickness of each light shielding layer 15 is substantially constant over the whole, and the variation in thickness between the light shielding layers 15 can be ignored. The width of each light shielding layer 15 is substantially constant over the entire length of the light shielding layer 15 in the thickness direction. The thickness of the light shielding layer 15 is T, the width is W, when the refractive index of the convex cylindrical lens 5 and a and n _c, the following equation (I) is satisfied. Here, the symbol “P _c ” in the formula (I) means the pitch of the convex cylindrical lenses 5 described above (the pitch between adjacent convex cylindrical lenses 5).

  By using the light diffusing unit 30 having the above-described structure, it becomes easy to obtain a transmission screen with good image contrast and high viewing angle characteristics. The reason for this will be described below with reference to FIGS.

  FIG. 2 shows an example of the optical path of the light diffusing member 30 shown in FIG. 1A, particularly when the light parallel to the optical axis OA of the convex cylindrical lens 5 is incident from the refractive surface side of the convex cylindrical lens 5. It is sectional drawing shown roughly. However, in FIG. 2, hatching is omitted for easy understanding of the optical path.

The individual convex cylindrical lens 5 shown in the figure has a condensing point F _{1 of} light L ₁ and L ₂ incident in the vicinity of the optical axis OA in parallel with the optical axis OA from the refracting surface side, outside the lenticular lens unit 10. The condensing point F _{2 of} the light L ₃ and L ₄ incident on the end of the convex cylindrical lens 5 in parallel with the optical axis OA from the refractive surface side is the outer surface of the boundary region 10 _p of the lenticular lens unit 10. It is an aspherical lens on the top.

These light L ₁ ~L ₄ is refracted at the interface B ₁ of the (air in the illustrated example) and the convex cylindrical lens 5 outside of the medium, the focal point F ₁ or unless blocked by the light blocking layer 15 After condensing once at the condensing point F ₂ , it diverges and enters the interface B ₂ between the lenticular lens unit 10 (boundary region 10 _p ) and the outside medium (air in the illustrated example). Then, if occurs totally reflected at the interface B ₂ is refracted at the interface B _2, emitted from the light diffusing member 30.

When the light L ₃ , L ₄ reaches the interface B ₂ without being blocked by the light shielding layer 15 and is emitted from the lenticular lens unit 10 without being totally reflected by the interface B ₂ , the light L ₃ , L _{4 is} more than the light L ₃ , L _4. Lights L ₁ and L ₂ incident on the refractive surface of the convex cylindrical lens 5 near the optical axis OA also reach the interface B ₂ without being blocked by the light shielding layer 15 and are not totally reflected at the interface B _2. The light is emitted from the lenticular lens unit 10.

As is clear from FIG. 2, light entering the refracting surface of each convex cylindrical lens 5 in parallel with the optical axis OA and exiting from the interface B ₂ (outer surface of the boundary region 10 _p ) is clarified from FIG. There is an area that does not become the optical path. In the light diffusing member 30, as already described, each light shielding layer 15 is provided in the above-described region that does not become an optical path.

Here, since the light L ₄ from the light diffusion member 30 is emitted, (see FIG. 2) incident angle φ of the light L ₄ to the interface B ₂ is required to be less than the critical angle. When the incident angle φ is a critical angle, the following equation (i) is established between the incident angle (critical angle) φ of the light L ₄ at the interface B ₂ and the refraction angle θ (see FIG. 2). Note that “1” on the right side of the equation (i) indicates the refractive index of air that is a medium outside the boundary region 10 _p , and “n _c ” indicates the refractive index of the convex cylindrical lens 5 as described above.

As is clear from this equation (i), when the incident angle φ of the light L ₄ to the interface B ₂ is a critical angle, the following equation (ii) is established.

In order for the light L ₄ to be emitted from the light diffusing member 30, the light L ₄ reaches the interface B ₂ without being blocked by the light shielding layer 15, and the incident angle φ of the light L ₄ to the interface B ₂ is the above formula (ii). It is necessary to be less than the angle represented by The thickness T of the light-shielding layer 15 in this case, by using the pitch P _c of the convex cylindrical lens 5 adjacent, the width W of the light-shielding layer 15, a φ angle of incidence of light L ₄ at the interface B ₂ Can be represented by the following formula (iii).

Since the light L ₄ and the light L ₃ are in a line-symmetric relationship with the optical axis OA as the symmetry axis, the light L ₃ reaches the interface B ₂ without being blocked by the light shielding layer 15 and is emitted from the interface B _2. The thickness T of the light shielding layer 15 that can be expressed can also be expressed by the above formula (iii).

Substituting the above equation (ii) into the equation (iii) and further taking into account that the thickness T of the light shielding layer 15 is a positive number, the above equation (I) is obtained. Therefore, by selecting the thickness T of the light shielding layer 15 as the formula (I) is satisfied, the total reflection emitted without being incident parallel to the optical axis OA to the refracting surface of the convex cylindrical lens 5 at the interface B ₂ It becomes easy to arrange the light shielding part outside the optical path of the light to be transmitted.

In the transmission screen configured using the light diffusing member 30, image light is projected from the refractive surface side of the convex cylindrical lens 5 to the interface B ₁ in parallel or substantially parallel to the optical axis OA of each convex cylindrical lens 5. . At this time, in the light diffusing member 30 in which the respective light shielding layers 15 are arranged as described above, substantially all of the image light that is not totally reflected at the interface B ₂ is not blocked by the light shielding layer 15. It will be emitted from. Therefore, the transmission screen configured using the light diffusing member 30 has high viewing angle characteristics.

FIG. 3 is a cross-sectional view schematically showing an optical path of light (external light) propagating from the above-described interface B ₂ (outer surface of the boundary region 10 _p ) into the lenticular lens unit 10. However, in FIG. 3, hatching is omitted for easy understanding of the optical path. Reference numerals “OL _{1 to} OL ₄ ” in FIG. 3 indicate light (external light) incident on the interface B ₂ . Further, the broken line in the figure virtually represents the upper surface of the light shielding layer thinner than the light shielding layer 15 shown in FIG. 1A, and the reference symbol “US” represents the virtually light thin light shielding layer. The upper surface of is shown.

As shown in FIG. 3, the angle of incidence of the light (external light) incident on the interface B ₂ is not constant, the light incident on the interface B ₂ propagates from the interface B ₂ to the lenticular lens portion 10. Some of the light propagating in the lenticular lens portion 10, like the light _{OL 1, OL 2, OL 4} shown in the figure, reaches the interface _{B 1} without being blocked by the light shielding layer 15, at the interface _{B 1} After being totally reflected once or a plurality of times, it is absorbed by the light shielding layer 15. Further, another part of the light propagated in the lenticular lens unit 10 is absorbed by the light shielding layer 15 immediately after propagating in the lenticular lens unit 10 as in the light OL ₃ shown in FIG.

Of course, the light propagating from the interface B ₂ into the lenticular lens unit 10 reaches the interface B ₁ without being absorbed by the light shielding layer 15, and is totally reflected once or a plurality of times at the interface ₁ and then returns to the interface B ₂ again. Some of them reach the outside of the lenticular lens unit 10 (retro-reflected light).

If the light blocking layer 15 is thick, as in the light OL _3, even light can not be blocked in the thin light shielding layer, blocking by the light shielding layer 15 immediately propagated to the lenticular lens portion 10 from the boundary region 10 _p be able to. Further, even if light such as the light OL ₄ cannot be prevented from being retroreflected by a thin light-shielding layer, if the light-shielding layer 15 is thick, it is shielded after being reflected at the interface B ₁ , and retroreflected light. Can be prevented.

State in the light diffusing member 30, since the light-shielding layer 15 is provided recess 10 _d formed on the other surface 10a of the thickness direction of the lenticular lens portion 10, which in FIG. 2, to protrude from the surface B ₂ in compared with the case of providing a light-shielding layer, without blocking the light emitted without incident on the refracting surface of the convex cylindrical lens 5 parallel to the optical axis OA is totally reflected at the interface B _2, the thickness of the light-shielding layer 15 The thickness can be made relatively thick. Therefore, in the transmissive screen configured using the light diffusing member 30, it is easy to prevent external light from being reflected (retroreflected) by the light shielding pattern 20 formed by each light shielding layer 15, and in particular, to emit light. It becomes easy to prevent the generation of retroreflected light having a small angle, in other words, retroreflected light that is easily visible in front of the transmission screen. As a result, it becomes easier to obtain a video with good contrast.

  In order to obtain a transmissive screen with good image contrast using the light diffusing member 30, the total area of each light shielding layer 15 in plan view occupying the area of the other surface 10 a in the thickness direction in plan view. It is preferable to select the width of each light shielding layer 15 so that the ratio is in the range of about 40 to 90% at least in the area corresponding to the display area of the transmissive screen, and the ratio is 50 to 80%. It is more preferable to select the width of each light shielding layer 15 so as to be within a range of about.

  As described above, in the light diffusing member 30, each light shielding layer 15 constituting the light shielding pattern 20 is arranged in a specific manner. Therefore, when a transmissive screen is configured using the light diffusing portion 30, It becomes easy to obtain a transmissive screen with good image contrast and high viewing angle characteristics. Even when the lenticular lens portion 10A shown in FIG. 1B is used instead of the lenticular lens 10 shown in FIG. 1A, the light-shielding pattern constituted by the light-shielding layer satisfying the above-described formula (I). By forming the light diffusing member, it is possible to obtain a light diffusing member that exhibits the same technical effect as described above.

(Light diffusing member; second form)
The light diffusing member of the present invention, the width W ₁ in terms of the refractive surface of the convex cylindrical lenses in the light-shielding layer may be narrower than the width W ₂ of the outer surface of the light-shielding layer.

FIG. 4 is a cross-sectional view schematically showing an example of the light diffusing member in which the width W ₁ is narrower than the width W ₂ . Light diffusing member 40 shown in the figure, except that the width W ₁ of the light-shielding layer constituting the light-shielding pattern is narrower than the width W _2, the same as the light diffusion member 30 shown in FIGS. 1 (a) It has a structure. Among the constituent members shown in FIG. 4, those common to the constituent members shown in FIG. 1A are given the same reference numerals as those used in FIG. . The light shielding pattern is given a new reference symbol “20A”, and each light shielding layer is given a new reference symbol “15A”.

In the light diffusing member 40, the width _{W 1} of the light-shielding layer 15A is narrower than the width _{W 2,} than the light diffusing member 30 shown in FIG. 1 (a), the width _{W 2} of each light-shielding layer 15A Easy to do. Therefore, according to the light diffusing member 40, it becomes easy to increase the ratio of the total area of each light shielding layer 15A in plan view to the area of the other surface 10a in the thickness direction of the lenticular lens portion 10 as a result. As compared with the case where the light diffusing member 30 shown in FIG.

Incidentally, in calculating the above formula (I) for the light diffusing member 40, using the above W ₁ as the width of the light shielding layer 15A.

(Light diffusing member; third embodiment)
In the light diffusing member of the present invention, the outer surface of each light shielding layer constituting the light shielding pattern and the region where the light shielding layer is not formed on the other surface in the thickness direction of the lenticular lens portion are covered. Thus, a light diffusion layer can be provided.

FIG. 5A is a cross-sectional view schematically showing an example of a light diffusing member including the light diffusing layer. In the light diffusing member 60 shown in the figure, the outer surface 15a (see FIG. 1A) of each light shielding layer 15 in the light diffusing member 30 shown in FIG. The light diffusion layer 50 is provided so as to directly cover a region (boundary region 10 _p ) where the light shielding layer 15 is not formed in the other surface 10a. Among the structural members shown in FIG. 5A, those common to the structural members shown in FIG. 1A are given the same reference numerals as those used in FIG. Is omitted.

  For example, the light diffusion layer 50 is formed by dispersing a large number of light diffusion materials 45 such as resin beads and glass beads in a transparent resin 43 serving as a matrix material. For example, the light diffusion layer 50 is formed by extrusion using a thermoplastic resin, a photocurable resin composition, an electron beam curable resin composition, or the like as a matrix raw material, and the light diffusion material 45 is dispersed in the raw material. An uncured layer is formed by a method such as coating or coating, and then the uncured layer is cured by a method such as cooling, light irradiation, electron beam irradiation, or the like. The content of the light diffusion material 45 in the light diffusion layer 50 is about 0.1 to 10% by mass depending on the degree of light diffusion required for the light diffusion layer 50, the type and size of the light diffusion material 45, and the like. It can be selected appropriately within the range.

FIG. 5B is a cross-sectional view schematically showing another example of the light diffusing member provided with the light diffusing layer. In the light diffusing member 80 shown in the figure, the outer surface 15a (see FIG. 1A) of each light shielding layer 15 in the light diffusing member 30 shown in FIG. A bonding agent layer 61 made of a transparent bonding agent such as a transparent adhesive or a transparent adhesive is coated so as to cover a region (boundary region 10 _p ) in which the light shielding layer 15 is not formed in the other surface 10a of A light diffusing layer 70 is affixed thereto. Among the structural members shown in FIG. 5B, those common to the structural members shown in FIG. 1A are given the same reference numerals as those used in FIG. Is omitted.

  The light diffusing layer 70 is, for example, a film-like material, a sheet-like material, or a plate-like material made of a transparent resin 63 serving as a matrix material in which a large number of light diffusing materials 65 such as resin beads or glass beads are dispersed. . The light diffusion layer 70 can be formed, for example, by using a thermoplastic resin as a matrix material and extruding the light diffusion material 65 in a state where the matrix material is dispersed. The content of the light diffusion material 65 in the light diffusion layer 70 is about 0.1 to 10% by mass depending on the degree of light diffusion required for the light diffusion layer 70, the type and size of the light diffusion material 65, and the like. It can be selected appropriately within the range. Affixing of the light diffusion layer 70 through the bonding agent layer 61 can be performed by, for example, a laminator.

  When a transmission screen is to be constructed using the light diffusion member 60 or the light diffusion member 80 described above, the degree of light diffusion by the light diffusion layer 50 or the light diffusion layer 70 is about 3 to 20 degrees in terms of the half-value angle of diffusion, The diffusion 1/3 value angle is preferably about 5 to 35 °, the diffusion half value angle is preferably about 5 to 15 °, and the diffusion 1/3 value angle is more preferably about 7 to 25 °. Further, when image light incident on the lenticular lens unit 10 is diffused in advance using, for example, a Fresnel lens having a diffusing action (hereinafter referred to as “diffuse Fresnel lens”), or light diffusion is performed on the lenticular lens unit 10 as well. When a material is added, in order to prevent trapping of image light by the light shielding layer 15 and to increase the diffusion in the vertical direction, the diffusion 1/3 value angle by the light diffusion layer 50 or the light diffusion layer 70 is set to a lenticular. It is preferable that the internal diffusion of the lens unit 10 (meaning the diffusion of light due to the added light diffusion material) and / or the diffusion 1/3 value angle of the diffusion Fresnel lens.

  When a transmissive screen is configured using the light diffusing member 60 or the light diffusing member 80, the image light is diffused in directions other than the direction in which the convex cylindrical lenses 5 are arranged. In addition to being high, it is possible to obtain a transmissive screen having good viewing angle characteristics in the vertical direction. In addition, since light scattering occurs in the light diffusion layer 50 or the light diffusion layer 70, the interface between the light diffusion layer 50 or the light diffusion layer 70 and a medium outside the light diffusion layer 50 even when the above-described formula (I) is satisfied. It is not possible to suppress total reflection at However, compared with a light diffusing member in which the above-described formula (I) does not hold (a light diffusing layer provided as a light transmissive layer), total reflection at the interface is suppressed, and both transmittance and contrast are high. A transmission screen with little scintillation can be obtained.

(Light diffusion member; 4th form)
The light diffusing member of the present invention is a layer having a desired function such as an antistatic layer, an antireflection layer, or an antiglare layer (hereinafter referred to as the outermost component on the other surface side in the thickness direction in the lenticular lens portion) This layer can be referred to as a “functional layer”).

  FIG. 6 is a cross-sectional view schematically showing an example of a light diffusing member having the functional layer. The light diffusing member 90 shown in the figure has a structure in which a functional layer 85 is provided on the outer surface of the light diffusing layer 70 in the light diffusing member 80 shown in FIG. 6 that are the same as those shown in FIG. 5B are assigned the same reference numerals as those used in FIG. 5B, and descriptions thereof are omitted. .

  The functional layer 85 may be formed directly on the light diffusion layer 70 as shown in the figure, or may be affixed on the light diffusion layer 70 using a transparent bonding agent (not shown). There may be. What function layer is provided as the functional member 85 is appropriately selected according to the application and grade of the light diffusion member 90. Further, two or more functional layers having different functions or a part in common may be appropriately selected and provided.

  By providing the antistatic layer as the functional layer 85, it is possible to suppress the adhesion of dust to the surface of the light diffusing member 90 (the surface of the functional layer 85). As a result, the light diffusing member 90 is used. In addition, the transmissive screen can easily maintain the optical characteristics even when the frequency of cleaning is low. Further, by providing an antireflection layer as the functional layer 85, reflection of external light on the surface of the light diffusing member 90 (surface of the functional layer 85) can be suppressed. As a result, the diffused light by the light diffusing member 90 is reduced. It is possible to suppress the reflected light from being superimposed. Further, by providing an antiglare layer as the functional layer 85, it is possible to suppress a glare when viewing the surface of the light diffusing member 90 (the surface of the functional layer 85). As a result, the light diffusing member 90 is used. It is also possible to suppress the glare of the transmissive screen constructed.

  Although the light diffusing member of the present invention has been described with reference to four forms, the form of the light diffusing member of the present invention is not limited to these forms. As long as each light shielding layer constituting the light shielding pattern is arranged in the above-described manner, it is possible to adopt a form in which various modifications, modifications, combinations, and the like are given in addition to the above-described form. For example, in order to obtain a light diffusing member having high self-supporting property (rigidity), a transparent substrate is attached to the other surface side in the thickness direction of the lenticular lens portion using a transparent bonding agent, and the transparent substrate is used as necessary. Thus, a structure in which a light diffusing layer or a functional layer is provided may be employed.

(Light diffusing member: fifth embodiment)
The present invention can be applied to a microlens array sheet having a so-called microlens array section in the same manner as the lenticular lens sheet. FIG. 7 is a schematic perspective view showing a further cutaway state of the light diffusing member of the present invention and showing a partially cut-out state. The light diffusing member 71 of this form is composed of “a large number of unit convex lenses 72” instead of the “many convex cylindrical lenses 5” constituting the light diffusing members of the first to fourth aspects, Instead of the “light-shielding pattern 20 made up of a large number of light-shielding layers 15”, the “light-shielding pattern 74 made up of the light-shielding layers 75 arranged in a matrix” is used.

  That is, the light diffusing member of the first to fourth embodiments is a lenticular lens sheet having a large number of convex cylindrical lenses that diffuse light mainly in the horizontal direction, whereas the light diffusing member 71 of the fifth embodiment is The micro lens array sheet has a large number of unit convex lenses 72 for diffusing light in the horizontal direction X and the vertical direction Y, but other configurations and specific numerical values may be the same. it can. Since the unit convex lens 72 can make the light diffusion in the vertical direction Y and the light diffusion in the horizontal direction X behave in the same manner, the light diffusion in the horizontal direction in the first to fourth embodiments. The behavior can be considered as it is by replacing it with the light diffusion behavior in the vertical direction. Therefore, the operation and effect of the light diffusing member 71 of the fifth embodiment are the same as those of the first to fourth embodiments, and redundant descriptions are omitted below.

Fifth embodiment of the light diffusing member 71, as shown in FIG. 7, each number of the unit lens 72 on one side of the thickness direction in a matrix, formed with a predetermined pitch longitudinally pitch P _V and the horizontal pitch P _H The sheet-like lens portion 73 (hereinafter, also referred to as “microlens array portion 73”) and the light shielding layer 75 arranged in a matrix on the other surface 10a in the thickness direction of the lens portion 73. And a light shielding pattern 74 made of As in the first to fourth embodiments, the outer surface of the light shielding layer 75 is substantially the same as the region 10p where the light shielding layer 75 is not formed in the other surface 10a in the thickness direction. It is on a plane. The matrix-shaped light shielding layer 75 is disposed outside the optical path of the light incident on one surface in the thickness direction and emitted from the other surface 10a in parallel with the optical axis OA of the unit convex lens 72. Further, the thickness of the light shielding layer 75 is T, a vertical width W _V of the light-shielding layer 75, the width and W _H, the refractive index of the unit lens 72 is taken as n _c, lower Formulas (II), (III ) Holds.

Here, the “refractive index” means a refractive index when the wavelength of the measurement light is 588 nm, and the units of the pitches P _H and P _V , the thickness T and the widths W _H and W _V are the same. If it does not matter. Further, the formulas (II) and (III) are derived according to the above-described formulas (i) to (iii) in the same manner as the formula (I) is derived. When the transmissive screen is constituted by the light diffusing member according to the present invention and the transmissive screen is mounted on the rear projection display, as shown in FIG. 7, the “vertical pitch P _V ” means the vertical direction Y “Horizontal pitch P _H ” means the pitch in the horizontal direction X, and “Vertical width W _V ” means the width in the vertical direction Y of the light shielding layer 75. “W _H ” means the width of the light shielding layer 75 in the horizontal direction X.

In addition, the light diffusing member 71 shown in FIG. 7 is provided on a microlens array sheet in which the other surface 10a in the thickness direction is formed into a flat surface and the other surface 10a of the microlens array sheet, and at least a boundary. it is an example of a two-layer structure having a "transparent resin layer 76" to form regions 10 _P. Of course, a single-layer structure composed of one microlens array sheet can be used as in the light diffusing member 30 shown in FIG. 1A, or a light diffusing member shown in FIG. A lens group composed of a large number of unit convex lenses 72 is formed on one side of the base film, and a transparent resin layer serving as a boundary region 10 _p (see FIG. 1A) is formed in a predetermined pattern on the other side of the base film. It is also possible to have a three-layer structure formed by a plurality of layers. When the microlens array sheet has a two-layer or three-layer laminated structure, it is preferable to suppress the physical interface between adjacent layers in the thickness direction from becoming an optical interface. The refractive index difference between these layers is preferably about 0.05 or less.

  The light diffusing member 71 having such a structure makes it easy to obtain a transmissive screen with good image contrast and high viewing angle characteristics. The reason for this is the same as in the case of the first embodiment described with reference to FIGS.

As for the relationship between the width W ₁ and W ₂ of the light-shielding layer 15A in the light diffusing member 40 of the second embodiment can be applied to the light diffusing member 71 of the fifth embodiment. That is, the horizontal and vertical widths of the light shielding layers 74 arranged in a matrix can be the same as the relationship. The light diffusion layers 50 and 70 in the light diffusion members 60 and 80 of the third form can also be applied to the light diffusion member 71 of the fifth form. The functional layer 85 in the light diffusing member 90 of the fourth form can also be applied to the light diffusing member 71 of the fifth form.

  According to the light diffusing member 71 of the fifth embodiment, the outer surface 75a of the light shielding layer 75 is substantially on the same plane as the region 10p where the light shielding layer 75 is not formed. The lens array portion 73 is projected. A combination of the light diffusing member 71 having the microlens array part 73 of such a form and a Fresnel lens sheet containing a large number of diffusing agents such as a Fresnel lens sheet preferably used in recent MD type rear projection televisions. When the ratio of the parallel light that has increased the diffusion component that has passed through the Fresnel lens sheet enters the microlens array unit 73 and becomes stray light is larger than that of the conventional case, the generated stray light is generated by the microlens array unit 73. There exists an advantage that it is easy to be caught with the light shielding layer 75 which consists of a form which protruded inside. As a result, stray light emitted from an unspecified portion of the light diffusing member 71 to the viewer side can be reduced, and problems such as a reduction in resolution and a reduction in contrast can be eliminated as much as possible.

  In addition, since the light shielding layer 75 protrudes into the microlens array portion 73, the light passing through the microlens array portion 73 is in the region 10p where the light shielding layer 75 is not formed. Even if stray light is generated due to reflection at the emission interface, such stray light has an advantage that it can be easily captured by the light shielding layer 75 having a shape protruding into the microlens array portion 73. As a result, stray light emitted from an unspecified portion of the light diffusing member 71 to the viewer side can be reduced, and problems such as a reduction in resolution and a reduction in contrast can be eliminated as much as possible.

The light diffusing member 71 to achieve the aforementioned advantageous effects, the light-shielding layer 75, the pitch P _V of the pitch P _H and a vertical direction in the horizontal direction of the unit lens 72, the width W _H and a vertical direction in the horizontal direction of the light shielding layer 75 the width W _V of, because it is formed to a thickness T satisfying the relationship between the refractive index n _c of the unit convex lens, a transmission type screen configured by using the light diffusing member 71, the thickness of the light shielding layer 75 Even if the thickness T is relatively thick, the image light to be emitted from the microlens array unit 73 is prevented from being blocked by the light shielding layer 75. Furthermore, since the thickness T of the light shielding layer 75 can be made relatively thick, it is easy to prevent retroreflection of light (external light) incident from the other surface 10a in the thickness direction of the microlens array portion 73, and in particular It is easy to prevent the generation of retroreflected light having a relatively small emission angle. By selecting the thickness T of the light shielding layer 75 so that the above formulas (II) and (III) are satisfied, the light enters the microlens array unit 73 from the one surface side parallel to the optical axis OA of the unit convex lens 72. Thus, it is easy to dispose the light shielding part outside the optical path of the light emitted from the other surface 10a without being totally reflected by the other surface 10a. For these reasons, according to the light diffusing member 71, it is easy to obtain a transmissive screen with good image contrast and high viewing angle characteristics.

(Manufacturing method of light diffusing member (manufacturing method A))
The production method A of the present invention can obtain the above-described light diffusing member of the present invention. As described above, the production method A includes a transparent layer forming step, a selective curing step, and a light shielding pattern formation. It includes a process. Hereinafter, it explains in full detail for every process. In addition, in the following description, the manufacturing method of the light diffusing member of the first to fourth embodiments and the manufacturing method of the light diffusing member of the fifth embodiment can be basically manufactured in the following steps unless otherwise specified. Therefore, for example, both are described in parallel by “or” such as a convex cylindrical lens or a unit convex lens, a lenticular lens portion or a microlens array portion, a lenticular lens sheet or a microlens array sheet, and the like.

(1) transparent layer forming step;
In the transparent layer forming step, first, a large number of convex cylindrical lenses or unit convex lenses are formed in parallel or vertically and horizontally at a certain pitch on one surface side in the thickness direction, and the other surface in the thickness direction is formed into a flat surface. Prepare a lenticular lens sheet or microlens array sheet. This lenticular lens sheet or microlens array sheet may have a single-layer structure, and a convex cylindrical lens group or unit convex lens group constituted by a large number of convex cylindrical lenses or unit convex lenses is formed on one side of a base film. It may be a two-layer structure. The lenticular lens sheet or microlens array sheet is used as a constituent member of the lenticular lens part or microlens array part in the light diffusing member of the present invention. For example, by extrusion molding or mold molding, or on a base film The ultraviolet curable resin composition layer is formed into a predetermined shape and cured to form a convex cylindrical lens group or a unit convex lens group. The refractive index of the lenticular lens sheet or microlens array sheet is preferably about 1.45 to 1.60 as described above. In addition, in the case where the lenticular lens sheet or the microlens array sheet has either a single-layer structure or a two-layer structure, a resin bead or A small amount of light diffusing material such as glass beads can be dispersed.

  Next, on the other surface in the thickness direction of the lenticular lens sheet or microlens array sheet, the refractive index in the cured state is substantially the same as the refractive index of the convex cylindrical lens or unit convex lens. A transparent layer having a thickness equal to or greater than the thickness of the light shielding layer in the light shielding pattern to be formed is formed using the linear curable resin composition.

  This transparent layer is formed by, for example, roll coating, bar coating, gravure coating, spinner coating, curtain coating, etc. on the other surface in the thickness direction of the lenticular lens sheet or microlens array sheet. It can be formed by coating.

  In order to obtain a highly practical light diffusing member, it is preferable to use a photocurable resin composition such as urethane, epoxy, ester, acrylic, and acrylate ester as the resin composition.

(2) selective curing step;
In the selective curing step, the transparent layer is selectively irradiated with light or an electron beam so that at least light parallel to the optical axis of the convex cylindrical lens or unit convex lens is emitted from the refractive surface side of the convex cylindrical lens or unit convex lens. The region that becomes the optical path when entering the lenticular lens sheet or the microlens array sheet is cured, and at least the region where the light shielding layer is to be formed is left uncured.

  When the transparent layer is selectively irradiated with light to selectively cure the transparent layer, the light is incident on the refractive surface of each convex cylindrical lens or unit convex lens in a state parallel or substantially parallel to the optical axis. Irradiation can be performed in a dark room, or irradiation can be performed in the dark room from the outer surface side of the transparent layer through a photomask having a predetermined shape in a state parallel or substantially parallel to the optical axis. On the other hand, when the transparent layer is selectively cured by selectively irradiating the transparent layer, the electron beam is irradiated from the outer surface side of the transparent layer through an electron beam mask having a predetermined shape. .

(3) a light shielding pattern forming step;
In the light shielding pattern forming step, the light shielding material layer is disposed on the transparent layer that has undergone the selective curing step, and a load larger than the yield point of the uncured region in the transparent layer is applied to the light shielding material layer. The light shielding material layer is selectively transferred to the uncured region, thereby forming a light shielding pattern.

  The light shielding material layer is formed on a desired substrate in a state corresponding to the shape and arrangement of each light shielding layer of the light shielding pattern to be formed, or covers all the light shielding layers to be formed. It is preferable that it is formed on the desired base material in the obtained state. Specific examples of the light-shielding material layer include a transfer layer in black transfer paper, a black toner layer, and the like. Hereinafter, a material in which a desired light-shielding material layer is formed on a substrate is referred to as a “transfer material”.

  Since the uncured region of the transparent layer has adhesiveness and the yield point is low, the transfer material is disposed or disposed so that the light-shielding material layer is in contact with this region, By applying a load larger than the yield point of the region, the light-shielding material layer can be selectively transferred and buried in the uncured region. After the above load is applied, the transfer material is peeled off. By selectively transferring the light shielding material layer in this manner, the light shielding pattern in the light diffusing member of the present invention is formed, and the lenticular lens portion or the microlens array portion is formed.

By sequentially performing the transparent layer forming step, the selective curing step, and the light shielding pattern forming step described above, the light diffusion member of the first form described above can be obtained. When the light shielding layer is formed by transfer, the region on the optical axis side of the convex cylindrical lens or unit convex lens in each light shielding layer is the boundary region indicated by reference numeral “10 _p ” in FIG. Therefore, it is preferable to perform a flattening step of flattening the protruding region by a method such as a roll press after the transfer step. Further, after the transfer step or the flattening step, the entire resin composition used as the raw material of the transparent layer may be cured by irradiating the uncured region with light or an electron beam as necessary. . Furthermore, the step of providing the light diffusion layer described with reference to FIGS. 5A and 5B, the step of providing the functional layer described with reference to FIG. 6, and the like may be performed.

Further, a black positive photosensitive resin composition is applied to the thickness of the light-shielding layer on the other surface in the thickness direction of the lenticular lens sheet or microlens array sheet, and the positive photosensitive resin composition is applied to the positive photosensitive resin composition. A light-shielding pattern is formed by irradiating light in the same manner as the light or electron beam irradiation in the selective curing step described above to selectively solubilize the photosensitive resin composition and then developing it. At the same time, even when a groove portion corresponding to the boundary region 10 _p between the light shielding patterns is filled with a transparent resin, the intended light diffusion member can be obtained.

(Production method of light diffusion member (production method B))
The manufacturing method B of the present invention can also obtain the above-described light diffusing member of the present invention, and this manufacturing method B includes a preparation step and a light shielding pattern forming step as described above. Hereinafter, it explains in full detail for every process.

(1) Preparation process;
In the preparation step, a large number of convex cylindrical lenses or unit convex lenses are formed in parallel or vertically and horizontally at a constant pitch on one surface side in the thickness direction, and a groove for forming a light shielding pattern is striped on the other surface side in the thickness direction. A lenticular lens member or a microlens array member in which grooves are formed in a matrix is prepared.

  Such a lenticular lens member or microlens array member can be directly obtained by, for example, extrusion molding or mold molding, and the above-mentioned one side of the lenticular lens sheet or microlens array sheet formed on one side is flat. It can also be obtained by selectively forming a transparent resin layer except for the region to be the groove. At this time, the lenticular lens sheet or the microlens array sheet may have a single layer structure, or a convex cylindrical lens group or unit convex lens group constituted by a large number of convex cylindrical lenses or unit convex lenses may be provided on one side of the base film. A two-layer structure may be formed. Moreover, as a raw material of said transparent resin layer, an ultraviolet curable resin composition can be used, for example. The refractive index of the lenticular lens portion or the microlens array portion is preferably about 1.45 to 1.60 as described above. In addition, a small amount of a light diffusing material such as resin beads or glass beads can be dispersed in the lenticular lens member or microlens array member as necessary. In the light diffusing member of the present invention manufactured by the manufacturing method B, the lenticular lens member or the microlens array member is directly used as the lenticular lens unit or the microlens array unit.

(2) light shielding pattern forming step;
In the light shielding pattern forming step, a light shielding material is applied to each of the groove portions in the lenticular lens member or the microlens array member to form a light shielding pattern. Specific examples of the light-shielding material used at this time include a material in which a light-absorbing substance such as black resin beads or black pigment is dispersed in a photocurable resin composition or an electron beam curable resin composition. .

The light shielding material can be applied to each groove by a method such as roll coating, bar coating, gravure coating, spinner coating, or curtain coating. Excess shading material overflowing from the groove is removed with a doctor blade or squeegee. At this time, if the resin composition in which black resin beads are dispersed is used as a light-shielding material, the outer surface of the boundary region indicated by reference numeral “10 _p ” in FIG. It becomes easy to suppress the substance (black resin beads) from remaining.

  Thereafter, the light shielding material in each groove is irradiated with light or an electron beam to cure the light shielding material, whereby a light shielding pattern can be obtained and the light diffusing member of the present invention can be obtained. In addition, after performing a light shielding pattern formation process, the process of providing the light-diffusion layer demonstrated with reference to Fig.5 (a) and FIG.5 (b), the process of providing the functional layer demonstrated with reference to FIG. May be performed.

(Transparent screen)
The transmission screen of the present invention includes the above-described light diffusing member of the present invention and a Fresnel lens sheet disposed outside the refractive surface of the convex cylindrical lens or unit convex lens in the light diffusing member.

  FIG. 8 is a perspective view schematically showing an example of the transmission screen of the present invention. The illustrated transmissive screen 110 includes the light diffusing member 30 shown in FIG. 1A and a Fresnel lens sheet 100 disposed outside the refractive surface of the convex cylindrical lens 5 in the light diffusing member 30. Yes. Since the light diffusion member 30 has already been described, the description thereof is omitted here. Of the constituent members shown in FIG. 8, those already described with reference to FIG. 1A are given the same reference numerals as those used in FIG. 1A, and description thereof is omitted.

  The Fresnel lens sheet 100 has a large number of prisms 95 on one surface in the thickness direction, and is formed in a concentric arc shape centering on an imaginary point O outside the surface, and the other surface in the thickness direction. Is formed into a flat surface. The imaginary point O means the vertical axis Ax of the Fresnel lens sheet 100 (an axis extending in the height direction of the Fresnel lens sheet 100 in the illustrated state) when the Fresnel lens sheet 100 is viewed from the front. The Fresnel lens sheet 100 is symmetrical with respect to the vertical axis Ax.

  In the Fresnel lens sheet 100, the pitch between the adjacent prisms 95 (meaning the interval between the apexes) is constant. This pitch is preferably about 1.0 mm or less, and more preferably about 0.1 mm or less so that each prism 95 is not visually recognized when a transmissive projection screen is configured using the Fresnel lens sheet 100. preferable. The shape of each prism 95 is such that visible light incident in a divergent light state from obliquely below the one surface as seen from the light diffusing member 30 side is made parallel or substantially parallel to the thickness direction of the Fresnel lens sheet 100. It is selected so that it can be converted.

  FIG. 9 is a perspective view schematically showing another example of the transmission screen of the present invention. The illustrated transmissive screen 111 includes the light diffusing member 80 shown in FIG. 5B and the Fresnel lens sheet 101 disposed outside the refractive surface of the convex cylindrical lens 5 in the light diffusing member 80. Yes. Since the light diffusion member 80 has already been described, the description thereof is omitted here. Among the structural members shown in FIG. 9, those already described with reference to FIG. 5B are denoted by the same reference numerals as those used in FIG. 5B, and description thereof is omitted.

  The Fresnel lens sheet 101 is a circular Fresnel lens in which a large number of prisms 95 are formed on one surface in the thickness direction and has a Fresnel center in the surface of the Fresnel lens sheet, and the other surface in the thickness direction is flat. It is molded. In FIG. 9, the surface having the prism 95 is provided on the light diffusion member 80 side. The pitch between the adjacent prisms 95 in the Fresnel lens sheet 101 (meaning the interval between the tops) is constant, and this pitch is determined when each transmissive screen is configured using the Fresnel lens sheet 101. Is preferably not more than about 1.0 mm, more preferably not more than about 0.1 mm. The shape of each prism 95 is such that visible light incident in a divergent light state from the normal direction of the one surface as viewed from the light diffusing member 80 side is converted into light that is parallel or substantially parallel to the thickness direction of the Fresnel lens sheet 101. It is selected so that it can be converted.

  FIG. 10 is a perspective view schematically showing still another example of the transmission screen of the present invention. The illustrated transmission screen 112 includes the light diffusing member 71 shown in FIG. 7 and the Fresnel lens sheet 101 disposed outside the refractive surface of the unit convex lens 72 in the light diffusing member 71. Since the light diffusing member 71 has already been described in the fifth embodiment, the description thereof is omitted here. Of the components shown in FIG. 10, those already described with reference to FIG. 7 are assigned the same reference numerals as those used in FIG. Also, since the Fresnel lens sheet 101 is a circular Fresnel lens sheet having the same Fresnel center in the sheet surface as that described with reference to FIG. 9, the description thereof is omitted.

  As described above, the light diffusing member of the present invention can be configured in combination with a circular Fresnel lens sheet having a Fresnel center in the sheet surface or a circular Fresnel lens sheet not in the sheet surface.

(Rear projection display)
FIG. 11 is a configuration diagram showing an example of a rear projection display equipped with a transmissive screen having the light diffusing member of the present invention as a constituent member. FIG. 11A is an example of a rear projection display equipped with a transmissive screen 110 (see, for example, FIG. 8) having a circular Fresnel lens with the Fresnel center outside the sheet surface. This is an example of a rear projection display equipped with a transmissive screen 111 (for example, see FIG. 9 and FIG. 10) having a circular Fresnel lens with the Fresnel center in the sheet plane.

  The rear projection displays 130a and 130b are provided with transmissive screens 110 and 111 having the light diffusing member of the present invention as constituent members in the front window portion, and the bottom portions of the relatively thin casings 122a and 122b. The light sources 124a and 124b are arranged, and mirrors 126a and 126b for reflecting the light from the light sources 124a and 124b toward the transmissive screens 110 and 111 are arranged on the inner surfaces of the rear walls of the casings 122a and 122b. The light sources 124a and 124b at this time may be a single tube type single light source using LCD (Liquid Crystal Display) or DLP (Digital Light Processing), or may be a RGB three tube type CRT light source. Good.

  In such rear projection displays 130a and 130b, the light source 124a and 124b and the mirrors 126a and 126b constitute a projection optical system, and the video light ML emitted from the light sources 124a and 124b is transmitted through the mirrors 126a and 126b. The light is reflected toward the mold screens 110 and 111 and enters the transmissive screens 110 and 111 in a divergent light state. The image light ML incident on the transmission screens 110 and 111 is converted into image light parallel or substantially parallel to the thickness direction of the Fresnel lens sheet by the Fresnel lens sheet, and further diffused by the light diffusing member to be rear projection type. The light is emitted from the displays 130a and 130b.

  As already described, since the light diffusing member of the present invention is easy to obtain a transmission screen with good image contrast and high viewing angle characteristics, the transmission screen has good image contrast. In addition, it is a transmissive screen that is easy to obtain with high viewing angle characteristics. Therefore, the rear projection display provided with this transmissive screen is a rear projection display that easily obtains a display with high display characteristics.

  Note that the transmission screen of the present invention is not limited to the transmission screen described above. As long as the light diffusing member of the present invention described above is used, various modifications, modifications, combinations, and the like can be made in addition to the transmission screen described above. For example, in place of the light diffusing member shown in FIG. 1, the light diffusing member shown in FIG. 4, FIG. 5 (a), FIG. 5 (b), FIG. In addition, as the Fresnel lens sheet, it is possible to use a plurality of annularly shaped prisms that are concentrically arranged around a virtual point in one surface in the thickness direction, and the planar shape is a band shape. Alternatively, a plurality of linear prisms (linear Fresnel lens sheet) formed in parallel may be used. The individual prisms constituting the Fresnel lens sheet may convert the direction distribution of the image light using total reflection, or convert the direction distribution of the image light using refraction. Also good.

  Hereinafter, the light diffusing member of the present invention will be described in detail with reference to examples.

Example 1
First, a polyester film having a thickness of 0.015 mm (refractive index; 1.5) is used as a base film, and a urethane-based ultraviolet curable resin composition having a refractive index of 1.5 is formed on one surface in the thickness direction of the polyester film. Using the object, a convex cylindrical lens group was formed to obtain a lenticular lens sheet. The above convex cylindrical lens group is formed by adjoining a large number of convex cylindrical lenses at a pitch of 0.050 mm, and the refractive surface of each convex cylindrical lens has a lateral radius (the direction in which a large number of convex cylindrical lenses are arranged). Is an aspherical surface having a vertical radius (radius in the thickness direction of the convex cylindrical lens) of 0.0360 mm. The maximum thickness of the lenticular lens sheet finally obtained (thickness from the top of the lenticular lens portion to the emission plane) is 0.0575 mm.

  Next, a negative photosensitive resin composition having a refractive index of 1.5 after curing is roll-coated on the back surface of the lenticular lens sheet, that is, on the exit surface side which is the other surface in the thickness direction of the polyester film. A photosensitive resin composition layer having a thickness of 0.011 mm was formed by coating by a method, and ultraviolet rays were irradiated substantially vertically from the refractive surface side of each convex cylindrical lens. Thereby, the photosensitive resin composition layer in the optical path of ultraviolet rays was selectively exposed and cured. The photosensitive resin composition layer outside the ultraviolet light path remains uncured.

  Next, the transfer material is arranged so that the light-shielding material layer (specifically, 2 μm-diameter black glass beads) is in contact with the photosensitive resin composition layer in an uncured state, and the uncured material remains on the transfer material. A load greater than the yield point of the photosensitive resin composition layer was applied to selectively transfer and bury the light-shielding material layer in the uncured photosensitive resin composition layer, and then the transfer material was peeled off. . Thereby, the light shielding pattern was formed from the many light shielding layers arrange | positioned at stripe form on the other surface side of the thickness direction in said polyester film, and the lenticular lens part was formed.

  The planar shape of each light shielding layer constituting the light shielding pattern is a strip shape having a width of 0.030 mm, and these light shielding layers are arranged at a pitch of 0.050 mm. Moreover, the thickness of each light shielding layer is 0.0112 mm. And the ratio (BS ratio) of the total area in planar view of each light shielding layer which occupies for the area of the back surface of a lenticular lens part is 60%.

  Thereafter, an acrylic pressure-sensitive adhesive layer (refractive index: 1.49) having a thickness of 15 μm is formed so as to cover the back surface of the lenticular lens portion and the light shielding pattern, and a light diffusion plate having a thickness of 2 mm is formed by this acrylic pressure-sensitive adhesive layer. Was joined to the lenticular lens part. The light diffusing plate is obtained by dispersing an acrylic styrene-based diffusing agent in an impact-resistant acrylic resin having a refractive index of 1.5, and its diffusion half-value angle is 6 °.

  By joining this light diffusing plate to the lenticular lens portion, the intended light diffusing member was obtained. By combining the light diffusing member and the Fresnel lens, it is possible to obtain a transmission screen having good viewing angle characteristics, high image contrast, and sharp image quality.

(Example 2)
First, a first mold roll having a large number of recesses for forming a convex cylindrical lens and a second mold roll for forming a recess 10d (see FIG. 1) are prepared, and the recesses of the first mold roll are prepared. These mold rolls were arranged close to the extruder so that the center of the second mold roll and the center of the convex part of the second mold roll face each other under a predetermined interval during molding.

  Next, a sheet of impact-resistant acrylic resin having a refractive index of 1.5 is formed by the above-described extruder, and is formed by the first mold roll and the second mold roll before the sheet is cooled and cured. Thus, a lenticular lens member was obtained.

  In this lenticular lens member, a large number of convex cylindrical lenses are formed at a pitch of 0.3 mm, and the refracting surface of each convex cylindrical lens has a lateral radius (radius in the arrangement direction of the large number of convex cylindrical lenses) of 0.1520 mm. The aspherical surface has a longitudinal radius (radius in the thickness direction of the convex cylindrical lens) of 0.2160 mm. The maximum thickness of the lenticular lens member (thickness from the top of the lenticular lens portion to the emission plane) is 0.345 mm, and the back surface has a band shape of 0.18 mm and a depth of 0.067 mm. Are formed with a pitch of 0.3 mm.

  Next, black ink was applied to each of the grooves by a bar coating method. At this time, excess black ink overflowing from the groove was removed with a doctor blade. Thereby, the light shielding layer which fills the said groove part one by one in one groove part was formed, and the light shielding pattern was obtained. The width of each light shielding layer is substantially constant in the thickness direction. In addition, the ratio (BS ratio) of the total area in plan view of each light shielding portion to the area of the back surface of the lenticular lens is 60%.

  Thereafter, a light diffusing plate was joined to the lenticular lens under the same conditions as in Example 1 to obtain a target light diffusing member. That is, an epoxy acrylate UV adhesive layer (refractive index: 1.49) having a thickness of 15 μm is formed so as to cover the back surface of the lenticular lens and the light shielding pattern, and a light diffusion plate having a thickness of 2 mm is formed by this adhesive layer. Bonded to a lenticular lens. The light diffusing plate is obtained by dispersing an acrylic styrene-based diffusing agent in an impact-resistant acrylic resin having a refractive index of 1.5, and its diffusion half-value angle is 6 °. By combining the light diffusing member and the Fresnel lens, it is possible to obtain a transmission screen having good viewing angle characteristics, high image contrast, and sharp image quality.

(Example 3)
First, a 0.015 mm thick polyester film (refractive index; 1.5) is used as a base film, and a urethane-based ultraviolet curable resin composition having a refractive index of 1.5 is formed on one surface in the thickness direction of the polyester film. A unit convex lens group was formed using the object to obtain a microlens array sheet. In the unit convex lens group, a large number of unit convex lenses are formed adjacent to each other with a pitch in the vertical direction Y (vertical pitch P _V ) of 0.040 mm and a pitch in the horizontal direction X (transverse pitch P _H ) of 0.050 mm. The refractive surface of each unit convex lens has an X-direction radius (radius in the horizontal direction X of many unit convex lenses; see FIG. 7) of 0.0253 mm, and a Y-direction radius (vertical direction Y of many unit convex lenses). (See FIG. 7) is 0.0253 mm, and the longitudinal radius (the radius in the thickness direction of the unit convex lens) is 0.0360 mm. In addition, the maximum thickness of the microlens array sheet finally obtained (thickness from the top of the microlens array portion to the emission plane) is 0.0575 mm.

  Next, a negative photosensitive resin composition having a refractive index of 1.5 after curing is rolled onto the back surface of the microlens array sheet, that is, the exit surface side that is the other surface in the thickness direction of the polyester film. A photosensitive resin composition layer having a thickness of 0.011 mm was formed by coating by a coating method, and ultraviolet rays were irradiated substantially perpendicularly from the refractive surface side of each unit convex lens. Thereby, the photosensitive resin composition layer in the optical path of ultraviolet rays was selectively exposed and cured. The photosensitive resin composition layer outside the ultraviolet light path remains uncured.

  Next, the transfer material is arranged so that the light-shielding material layer (specifically, 2 μm-diameter black glass beads) is in contact with the photosensitive resin composition layer in an uncured state, and the uncured material remains on the transfer material. A load greater than the yield point of the photosensitive resin composition layer was applied to selectively transfer and bury the light-shielding material layer in the uncured photosensitive resin composition layer, and then the transfer material was peeled off. . Thereby, on the other surface side in the thickness direction of the polyester film, a light shielding pattern was formed from a large number of light shielding layers arranged in a matrix, and a microlens array portion was formed.

  The planar shape of each light shielding layer constituting the light shielding pattern is a lattice shape having a width of 0.030 mm × a height of 0.020 mm, and the rectangular transparent resin portion 76 surrounded by the lattice has a width of 0. It is arranged in a square shape of 020 mm × vertical width 0.020 mm (that is, the arrangement period is 0.050 mm in the horizontal direction X which is the horizontal direction and 0.040 mm in the vertical direction Y which is the vertical direction). Yes. Moreover, the thickness of each light shielding layer is 0.0112 mm. And the ratio (BM ratio: black matrix ratio) of the total area in the planar view of each light shielding layer to the area of the back surface of a micro lens array part is 80%.

  After that, the thickness of the microlens array portion is 15 μm so as to cover the back surface and the light shielding pattern (the thickness on the other surface of the fly-eye lens exposed without being covered by the light shielding pattern). The acrylic pressure-sensitive adhesive layer (refractive index 1.49) was formed, and a light diffusion plate having a thickness of 2 mm was bonded to the microlens array portion by this acrylic pressure-sensitive adhesive layer. The light diffusing plate is obtained by dispersing an acrylic styrene-based diffusing agent in an impact-resistant acrylic resin having a refractive index of 1.5, and its diffusion half-value angle is 6 °.

  By joining this light diffusing plate to the microlens array part, a microlens array sheet as a target light diffusing member was obtained. By combining the light diffusing member and the Fresnel lens, it is possible to obtain a transmission screen having good viewing angle characteristics, high image contrast, and sharp image quality.

FIG. 1A is a cross-sectional view schematically showing a basic structure of a light diffusing member of the present invention having a single-layer lenticular lens portion, and FIG. 1B shows a light diffusing member of the present invention. It is sectional drawing which shows roughly an example of the lenticular lens part of the 3 layer structure which can be comprised. It is sectional drawing which shows roughly an example of an optical path when the light parallel to the optical axis of a convex cylindrical lens injects into the light-diffusion member shown to Fig.1 (a) from the refractive surface side of a convex cylindrical lens. It is a cross-sectional view schematically showing an optical path of the light (external light) that propagates from the interface B ₂ to the lenticular lens portion on the light diffusing member shown in FIG. It is sectional drawing which shows schematically an example of the light-diffusion member of the light-diffusion member of this invention where the width | variety of the surface by the side of the refractive surface of the convex cylindrical lens in a light shielding layer is narrower than the width | variety of the outer surface in the said light-shielding layer. . FIG. 5A is a cross-sectional view schematically showing an example of the light diffusing member of the present invention provided with a light diffusing layer, and FIG. 5B shows the light diffusing member of the present invention. It is sectional drawing which shows roughly the other example provided with the light-diffusion layer. It is sectional drawing which shows roughly an example of what has a structure in which the functional layer was provided as the outermost component of the other surface side of the thickness direction in the lenticular lens part among the light-diffusion members of this invention. It is a typical perspective view which shows the state where a part was notched which shows the further another form of the light-diffusion member of this invention. It is a perspective view which shows roughly an example of the transmission type screen of this invention. It is a perspective view which shows schematically another example of the transmission type screen of this invention. It is a perspective view which shows roughly another example of the transmission type screen of this invention. It is a block diagram which shows the example of the rear projection type display with which the transmission type screen which has the light-diffusion member of this invention as a structural member was mounted | worn.

Explanation of symbols

DESCRIPTION OF SYMBOLS 5 Convex cylindrical lens 10, 10A Lenticular lens part 10a The other surface of the lenticular lens part and the micro lens array part in the thickness direction 10 _{p The} light shielding layer among the other surfaces in the thickness direction of the lenticular lens part and the micro lens array part Area where no is formed (boundary area)
DESCRIPTION OF SYMBOLS 15 Light-shielding layer 15a Outer surface of light-shielding layer 20 Light-shielding pattern 30,40,50,60,71,80 Light-diffusion member 50,70 Light-diffusion layer 61 Bonding agent layer 63 Transparent resin 65 Light-diffusion material 72 Unit convex lens 73 Micro lens array Part 74 Light-shielding pattern 75 Light-shielding layer 85 Outermost component on the other surface side in the thickness direction in the lenticular lens part and microlens array part (functional layer; antistatic layer, antireflection layer, antiglare layer, etc.)
95 prisms 100 and 101 width of the Fresnel lens sheet 110, 111 transmission type screen OA convex cylindrical lens and a unit lens optical axis F ₁ the convex cylindrical lenses of the parallel light incident on the vicinity of the optical axis of the converging point F ₂ convex cylindrical lens Focusing point of parallel light incident on the end of the direction

Claims (16)

A sheet-like lenticular lens portion in which a plurality of convex cylindrical lenses are formed in parallel at a constant pitch _Pc on one surface side in the thickness direction, and a stripe shape on the other surface in the thickness direction of the lenticular lens portion A light diffusing member having a light shielding pattern composed of a large number of light shielding layers arranged in
The outer surface of the light shielding layer is on the same plane as the region where the light shielding layer is not formed on the other surface in the thickness direction, and the light shielding layer is formed on the convex cylindrical lens. It is arranged outside the optical path of the light that is incident on one surface in the thickness direction parallel to the optical axis and exits from the other surface,
Wherein the thickness of the light shielding layer is T, the width of the light shielding layer is W, the refractive index of the convex cylindrical lens is taken as n _c, the light diffusing member, characterized in that the following formula (I) is satisfied.

  The convex cylindrical lens is an aspherical lens in which the condensing point near the optical axis is farther than the condensing point at the end in the width direction, and the condensing point at the end in the width direction is the other surface. The light diffusing member according to claim 1, wherein the light diffusing member is located above.   The light diffusing member according to claim 1, further comprising a light diffusing layer that covers an outer surface of the light shielding layer and a region of the other surface where the light shielding layer is not formed.   The light diffusion member according to claim 3, wherein the degree of diffusion of light in the vertical direction in the light diffusion layer is greater than the degree of diffusion of light in the vertical direction until reaching the light diffusion layer. .   5. The light according to claim 1, further comprising at least one of an antistatic layer, an antireflection layer, and an antiglare layer as the outermost component on the other surface side. Diffusion member. It is a manufacturing method of the light diffusing member given in any 1 paragraph of Claims 1-5,
A lenticular lens sheet is prepared in which a number of convex cylindrical lenses are formed in parallel at a constant pitch on one surface side in the thickness direction, and the other surface in the thickness direction is formed flat. A light-shielding pattern to be formed on the other surface using a photocurable or electron beam curable resin composition having a refractive index in a cured state substantially the same as the refractive index of the convex cylindrical lens A transparent layer forming step of forming a transparent layer having a thickness equal to or greater than the thickness of the light shielding layer at
When the transparent layer is selectively irradiated with light or an electron beam and at least light parallel to the optical axis of the convex cylindrical lens is incident on the lenticular lens sheet from the one surface side, an area that becomes an optical path is A selective curing step that cures and leaves at least the areas where the light shielding layer is to be formed uncured;
A light-shielding material layer is disposed on the transparent layer that has undergone the selective curing step, and the uncured material layer is applied with a load greater than the yield point of the uncured region in the transparent layer. A light-shielding pattern forming step of selectively transferring the light-shielding material layer to the region as it is, thereby forming a light-shielding pattern, thereby producing a light diffusing member. It is a manufacturing method of the light diffusing member given in any 1 paragraph of Claims 1-5,
A lenticular lens in which a number of convex cylindrical lenses are formed in parallel at a constant pitch on one surface side in the thickness direction, and a groove portion for forming a light shielding pattern is formed in a stripe shape on the other surface side in the thickness direction. A preparation step of preparing a member;
And a light shielding pattern forming step of forming a light shielding pattern by applying a light shielding material to the groove.   A transmissive screen comprising: the light diffusing member according to any one of claims 1 to 5; and a Fresnel lens sheet disposed outside the refractive surface of the convex cylindrical lens in the light diffusing member. . Each one a plurality of unit lens is vertically and horizontally the surface side of the thickness direction, a constant and vertical pitch P _V and the horizontal pitch P _H sheet formed by the lens unit, the other in the thickness direction of the lens unit A light diffusing member having a light shielding pattern comprising a light shielding layer arranged in a matrix on the surface of
The outer surface of the light shielding layer is on the same plane as the region where the light shielding layer is not formed on the other surface in the thickness direction, and the light shielding layer is light of the unit convex lens. It is disposed outside the optical path of the light that is incident on one surface in the thickness direction parallel to the axis and is emitted from the other surface,
Wherein the thickness of the light shielding layer is T, the vertical width W _V of the light-shielding layer, the width and W _H, the refractive index of the unit lens is taken as n _c, the following equation (II), is (III) A light diffusing member characterized by comprising.

  The unit convex lens is an aspherical lens in which the condensing point near the optical axis is farther than the condensing point at the end in the width direction, and the condensing point at the end in the width direction is on the other surface. The light diffusing member according to claim 9, wherein   The light diffusing member according to claim 9, further comprising a light diffusing layer that covers an outer surface of the light shielding layer and a region of the other surface where the light shielding layer is not formed.   The light diffusion member according to claim 11, wherein a degree of diffusion of light in the vertical direction in the light diffusion layer is larger than a degree of diffusion of light in the vertical direction until reaching the light diffusion layer. .   The light according to any one of claims 9 to 12, further comprising at least one of an antistatic layer, an antireflection layer, and an antiglare layer as the outermost component on the other surface side. Diffusion member. It is a manufacturing method of the light diffusing member given in any 1 paragraph of Claims 9-13,
A microlens array sheet is prepared in which a number of unit convex lenses are formed in parallel at a constant pitch on one surface side in the thickness direction, and the other surface in the thickness direction is formed into a flat surface. An attempt is made to form the other surface of the lens array sheet using a photocurable or electron beam curable resin composition having a refractive index in a cured state substantially the same as the refractive index of the unit convex lens. A transparent layer forming step of forming a transparent layer having a thickness equal to or greater than the thickness of the light shielding layer in the light shielding pattern;
When the transparent layer is selectively irradiated with light or an electron beam and at least light parallel to the optical axis of the unit convex lens is incident on the microlens array sheet from the one surface side, an area that becomes an optical path is A selective curing step that cures and leaves at least the areas where the light shielding layer is to be formed uncured;
A light-shielding material layer is disposed on the transparent layer that has undergone the selective curing step, and the uncured material layer is applied with a load greater than the yield point of the uncured region in the transparent layer. A light-shielding pattern forming step of selectively transferring the light-shielding material layer to the region as it is, thereby forming a light-shielding pattern, thereby producing a light diffusing member. It is a manufacturing method of the light diffusing member given in any 1 paragraph of Claims 9-13,
A plurality of unit convex lenses are formed on one surface side in the thickness direction in parallel at constant pitches in the vertical and horizontal directions, and a light shielding pattern forming groove is formed in a matrix on the other surface side in the thickness direction. A preparation step of preparing a lens array member;
And a light shielding pattern forming step of forming a light shielding pattern by applying a light shielding material to the groove.   A transmissive screen comprising: the light diffusing member according to any one of claims 9 to 13; and a Fresnel lens sheet disposed outside the refractive surface of the unit convex lens in the light diffusing member.

Images