JP2006031045A - Method for manufacturing member for transmission type screen, member for the transmission type screen, and the transmission-type screen and rear type projector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a transmission type screen superior in the characteristic of the angle of view and the utilization efficiency of light, and to provide a rear type projector equipped with the transmission type screen. <P>SOLUTION: The member for the transmission type screen 1 is manufactured by a method including a step of forming a 1st layer containing positive type photopolymer on the surface of a microlens base plate 3 on a side opposite from the surface on a side where a microlens 32 is formed, a step of exposing the 1st layer by irradiating the 1st layer with light condensed by the microlens 32, a step of forming a black matrix 4 having an aperture part 41 by developing processing, a step of forming a 2nd layer containing negative type photopolymer on the surface on a side where the black matrix 4 is formed, a step of exposing the 2nd layer by irradiating the 2nd layer with the light condensed by the microlens 32, and a step of forming a light-diffusing part 5 composed of a material containing a diffusion material 51 by the developing processing. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for manufacturing a transmissive screen member, a transmissive screen member, a transmissive screen, and a rear projector.

In recent years, the demand for rear-type projectors is increasing as a display suitable for home theater monitors, large-screen televisions, and the like.
A lenticular lens is generally used for a transmissive screen used in a rear projector. However, such a rear projector has a problem that the left and right viewing angles are large but the top and bottom viewing angles are small (the viewing angles are biased).

  For the purpose of solving such problems, a microlens (microlens array sheet) is used instead of the lenticular lens, and a black matrix provided on the light exit surface side of the microlens array sheet, and the microlens array sheet A transmission screen having a light diffusion layer provided on the entire surface on the light exit surface side of the light has been proposed (see, for example, Patent Document 1). In this transmissive screen, the horizontal viewing angle and the vertical viewing angle are controlled by the microlenses arranged in a matrix, and the light is diffused by the diffusion layer, so that the viewing angle can be increased.

  However, in such a transmissive screen, light (photons) incident on the diffusion layer collides with the diffusing material at a high frequency, so that light (photons) incident on the diffusion layer is reflected by the diffusion layer, It becomes easy to return to the back side (incident surface side), and the degree of quenching due to collision with the diffusing material is increased. For this reason, such a transmissive screen has a problem that light utilization efficiency is low. Further, in such a transmission type screen, light diffusion occurs at a high frequency even in a portion of the light diffusion layer provided on the black matrix (on the light emission surface side of the black matrix). Despite being provided, there are cases where sufficient contrast cannot be obtained in the displayed image.

JP 2003-177476 A (Claims, FIGS. 4 to 7)

  An object of the present invention is to provide a transmission screen excellent in viewing angle characteristics and light utilization efficiency, and a manufacturing method capable of easily and reliably providing a transmission screen member constituting the transmission screen. It is another object of the present invention to provide a rear projector including the transmission screen.

Such an object is achieved by the present invention described below.
The method for manufacturing a transmission screen member of the present invention includes a lens substrate having a plurality of lens portions that collect incident light;
A light-shielding layer formed on the light emission side from the lens unit and having an opening on the optical path of the light transmitted through the lens unit;
A method for manufacturing a transmissive screen member comprising a light diffusing part having a function of diffusing light transmitted through the lens part,
The light diffusing portion is made of a material containing a diffusing material,
A negative type photopolymer is included on the surface on which the light shielding layer is formed with respect to the lens substrate on which the light shielding layer is formed on the surface opposite to the surface on which the lens portion is formed. Applying a second material and forming a second layer;
Exposing the second layer by irradiating the second layer with light incident from the side of the lens substrate on which the lens portion is formed and condensed by the lens portion; ,
A step of developing the second layer so that a portion exposed by the condensed light remains, and forming the light diffusion portion.
As a result, it is possible to easily and reliably provide a transmission screen having excellent viewing angle characteristics and light utilization efficiency.

The method for manufacturing a transmission screen member of the present invention includes a lens substrate having a plurality of lens portions that collect incident light;
A light-shielding layer formed on the light emission side from the lens unit and having an opening on the optical path of the light transmitted through the lens unit;
A method for manufacturing a transmissive screen member comprising a light diffusing part having a function of diffusing light transmitted through the lens part,
The light diffusing portion is made of a material containing a diffusing material,
Applying a first material containing a positive type photopolymer to a surface of the lens substrate opposite to a surface on which the lens portion is formed, and forming a first layer;
Exposing the first layer by irradiating the first layer with light incident from a surface side where the lens portion of the lens substrate is formed and condensing the light by the lens portion; ,
A step of developing the first layer to remove a portion exposed by the condensed light, and forming the light-shielding layer having the opening;
Applying a second material containing a negative photopolymer to the surface of the lens substrate on which the light-shielding layer is formed, and forming a second layer;
Exposing the second layer by irradiating the second layer with light incident from the side of the lens substrate on which the lens portion is formed and condensed by the lens portion; ,
A step of developing the second layer so that a portion exposed by the condensed light remains, and forming the light diffusion portion.
As a result, it is possible to easily and reliably provide a transmission screen having excellent viewing angle characteristics and light utilization efficiency.

In the method for manufacturing a transmissive screen member of the present invention, it is preferable that the lens portion is designed so as to focus on the light emission side with respect to the light shielding layer.
Thereby, the light utilization efficiency of the transmission screen can be further improved.
In the transmissive screen member manufacturing method of the present invention, it is preferable that the light diffusing portion is formed so that a portion corresponding to the opening portion is a protruding portion protruding to the light emitting side.
As a result, the light utilization efficiency of the transmission screen can be further improved, and the contrast of the projected image can be particularly improved.

In the method for manufacturing a transmission screen member according to the present invention, when the transmission screen member is viewed in plan, the proportion of the area occupied by the protruding portion in the effective region where the lens portion is formed is 5 to 99%. Preferably there is.
Thereby, the light utilization efficiency of the transmission screen can be further improved. Further, the contrast of the projected image can be further improved.

In the transmissive screen member manufacturing method of the present invention, it is preferable that the plurality of light diffusion portions corresponding to the respective openings of the light shielding layer are formed so as to be independent of each other.
As a result, the light utilization efficiency of the transmission screen can be further improved, and the contrast of the projected image can be particularly improved.
In the method for manufacturing a transmission screen member of the present invention, when the transmission screen member is viewed in plan, the ratio of the area occupied by the light diffusion portion in the effective region where the lens portion is formed is 5 to 99%. It is preferable that
As a result, the viewing angle characteristics and light utilization efficiency of the transmissive screen can be further improved, and the contrast of the projected image can be particularly improved.

In the transmissive screen member manufacturing method of the present invention, it is preferable that the length of the light diffusion portion in the direction perpendicular to the main surface of the transmissive screen member is 2 to 450 μm.
Thereby, the light utilization efficiency of the transmission screen can be further improved.
In the transmissive screen member manufacturing method of the present invention, it is preferable that the focal point of the lens portion is substantially the center of the light diffusing portion in a direction perpendicular to the main surface of the transmissive screen member.
Thereby, the light utilization efficiency of the transmission screen can be further improved.

In the transmissive screen member manufacturing method of the present invention, it is preferable that the lens substrate is manufactured using a substrate with a recess having a recess having a shape corresponding to the lens portion.
Thereby, it is possible to easily and reliably obtain a lens substrate in which lens portions having a desired size and shape are arranged in a desired pattern. As a result, the productivity of the transmissive screen is improved, and the obtained transmissive screen has stable characteristics and high reliability.

In the method for manufacturing a transmissive screen member of the present invention, the ratio of the area occupied by the lens unit in the effective region where the lens unit is formed when the lens substrate is viewed in plan from the light incident surface side. It is preferably 90% or more.
Thereby, the light utilization efficiency of the transmissive screen can be further improved.
In the method for manufacturing a transmissive screen member of the present invention, the lens portion is preferably a microlens.
Thereby, the viewing angle characteristics of the transmissive screen can be further improved. More specifically, the vertical viewing angle can be increased along with the horizontal viewing angle.

In the method for manufacturing a transmissive screen member of the present invention, it is preferable that the plurality of microlenses have substantially the same radius of curvature.
Thereby, the light shielding layer having the opening and the light diffusing portion can be easily formed. As a result, the productivity of the transmission screen member can be made particularly excellent.
In the method for manufacturing a transmissive screen member of the present invention, the diameter of the microlens is preferably 10 to 500 μm.
Thereby, sufficient resolution can be obtained in the projected image while the productivity of the transmissive screen member is sufficiently high.

In the method for manufacturing a transmissive screen member of the present invention, the diameter of the opening is preferably 9 to 500 μm.
Thereby, sufficient light permeability (light utilization efficiency) can be obtained while further improving the contrast of the projected image.
The transmission screen member of the present invention is manufactured by the method of the present invention.
As a result, it is possible to provide a transmission screen having excellent viewing angle characteristics and light utilization efficiency.

The transmission screen of the present invention is characterized by including the transmission screen member of the present invention.
As a result, it is possible to provide a transmission screen having excellent viewing angle characteristics and light utilization efficiency.
The transmissive screen of the present invention, a Fresnel lens portion in which a Fresnel lens is formed on the light emission side,
The transmission screen member of the present invention is provided on the light emission side of the Fresnel lens portion.
As a result, it is possible to provide a transmission screen having excellent viewing angle characteristics and light utilization efficiency.

A rear projector according to the present invention includes the transmissive screen member according to the present invention.
As a result, it is possible to provide a rear projector having excellent viewing angle characteristics and light utilization efficiency.
A rear projector according to the present invention includes the transmission screen according to the present invention.
As a result, it is possible to provide a rear projector having excellent viewing angle characteristics and light utilization efficiency.
The rear projector according to the present invention preferably includes a projection optical unit and a light guide mirror.
As a result, it is possible to provide a rear projector having excellent viewing angle characteristics and light utilization efficiency.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a method for producing a transmission screen member, a transmission screen member, a transmission screen, and a rear projector according to the present invention will be described in detail based on preferred embodiments shown in the accompanying drawings.
First, the structure of the transmissive screen member and the transmissive screen of the present invention will be described.

  1 is a schematic longitudinal sectional view showing a preferred embodiment of a transmission screen member of the present invention, FIG. 2 is a plan view of a microlens substrate provided in the transmission screen member shown in FIG. These are typical longitudinal cross-sectional views which show suitable embodiment of the transmission type screen of this invention provided with the member for transmission type screens shown in FIG. In the following description, the left side in FIGS. 1 and 3 is referred to as “(light) incident side”, and the right side is referred to as “(light) emission side”.

The transmissive screen member 1 is a member constituting a transmissive screen 10 to be described later. As shown in FIG. 1, the transmissive screen member 1 has a microlens substrate (lens substrate) 3 having a function of collecting incident light and a light shielding property. It has a black matrix (light-shielding layer) 4 made of a material having a light diffusion portion 5 having a function of diffusing incident light by irregular reflection.
The microlens substrate 3 includes a resin layer 31 and a large number of microlenses (lens portions) 32 formed on the surface on the incident side of the resin layer 31.
The resin layer 31 is mainly composed of a resin material, and is composed of a transparent material having a predetermined refractive index.

  Each microlens 32 is formed as a convex lens that protrudes toward the incident side, and is designed so that the focal point f is located on the emission side with respect to the black matrix (light shielding layer) 4. That is, parallel light La (parallel light La from a Fresnel lens portion 2 described later) incident on the microlens substrate 3 from a substantially perpendicular direction is condensed by each microlens 32 of the microlens substrate 3 and is black. The focal point f is formed on the emission side from the matrix (light shielding layer) 4. As described above, when the microlens 32 is focused on the light emission side of the black matrix (light shielding layer) 4, the light utilization efficiency can be made particularly excellent. More specifically, if the light emitted from the microlens 32 is collected by the light diffusion unit 5 described later, it is as if there is a light source in the light diffusion unit 5 on the light emission side of the black matrix 4. The light (photons) collected by the microlens 32 is effectively prevented from returning to the light incident side again, and the light incident on the light diffusion unit 5 is moved to the output side. It can be diffused efficiently. As a result, the light utilization efficiency can be made particularly excellent, and the viewing angle characteristics of the transmission screen 10 (transmission screen member 1) are also excellent.

  The focal point of the micro lens 32 is preferably on the emission side of 1 to 250 μm and more preferably on the emission side of 2 to 50 μm from the black matrix 4 (surface on the light emission side of the black matrix 4). When the position of the focal point is on the incident side from the range, depending on the type and content of the diffusing material 51 included in the light diffusing unit 5, the amount of light returning from the light diffusing unit 5 to the incident side increases. There is a possibility that sufficient light utilization efficiency cannot be obtained. In addition, when the position of the focal point f is on the emission side from the above range, depending on the height h of the light diffusing unit 5 to be described later, light diffusion by the light diffusing unit 5 becomes insufficient, and the viewing angle characteristics are improved. There is a possibility that the effect of improving cannot be sufficiently obtained.

  The diameter of the microlens 32 is preferably 10 to 500 μm, more preferably 30 to 300 μm, and still more preferably 50 to 100 μm. When the diameter of the micro lens 32 is a value within the above range, the productivity of the transmissive screen member 1 (the transmissive screen 10) can be further enhanced while maintaining a sufficient resolution in the image projected on the screen. it can. In the microlens substrate 3, the pitch between the adjacent microlenses 32 to the microlenses 32 is preferably 10 to 500 μm, more preferably 30 to 300 μm, and further preferably 50 to 100 μm. preferable.

  The curvature radii of the plurality of microlenses 32 constituting the transmissive screen member 1 are preferably substantially equal to each other, and the curvature radii of almost all the microlenses constituting the transmissive screen member 1 are the same. More preferably, they are substantially equal to each other. Thereby, the black matrix 4 and the light-diffusion part 5 can be formed more easily and reliably by the method (The manufacturing method of the transmission type screen member of this invention) which is mentioned later.

  Further, the arrangement method of the microlenses 32 is not particularly limited. Even if the arrangement is a periodic arrangement, an optically random arrangement (planar view from the main surface side of the transmission screen member 1 (microlens substrate 3)). In this case, the microlenses 32 may be arranged in a random positional relationship with each other, but a random arrangement as shown in FIG. 2 is preferable. By arranging the microlenses 32 at random, it is possible to more effectively prevent interference with a light valve such as a liquid crystal or a Fresnel lens, and it is possible to almost completely eliminate the occurrence of moire. Thereby, the excellent transmissive screen 10 with good display quality can be obtained.

  Further, the area occupied by the microlens (lens portion) 32 in the effective region where the microlens 32 is formed when the microlens substrate 3 is viewed in plan from the light incident surface side (direction shown in FIG. 2) ( The ratio of (projected area) is preferably 90% or more, and more preferably 96% or more. When the proportion of the area occupied by the microlenses 32 is 90% or more, the straight light passing through (transmitting) other than the microlenses 32 can be further reduced, and the light utilization efficiency can be further improved.

As described above, the black matrix 4 and the light diffusion portion 5 are formed on the exit surface of the microlens substrate 3.
The black matrix 4 is made of a light-shielding material and is formed in a layer shape. By having such a black matrix 4, the black matrix 4 can absorb external light (external light that is not preferable for forming a projection image), and the image projected on the screen has excellent contrast. Can be.
Such a black matrix 4 has an opening 41 on the optical path of the light transmitted through each microlens 32. Thereby, the light condensed by each microlens 32 can pass through the opening 41 of the black matrix 4 and enter the light diffusion portion 5.

  Although the magnitude | size of the opening part 41 is not specifically limited, It is preferable that the diameter is 9-500 micrometers, It is more preferable that it is 9-450 micrometers, It is further more preferable that it is 20-90 micrometers. When the diameter of the opening 41 is in such a range, the light transmitted through each microlens 32 can be efficiently incident on the light diffusion unit 5 described later, and an image projected on the screen can be displayed. , The contrast can be improved.

  The light diffusing unit 5 has a function of diffusing incident light (incident light) by irregular reflection. By having such a light diffusing portion 5, the viewing angle characteristics can be made excellent. The light diffusing unit 5 has a region formed on the light emission side from the black matrix 4. With such a configuration, the light incident on the light diffusing unit 5 can be efficiently directed to the emission side (the direction opposite to the light incident side), and the viewing angle characteristics of the transmissive screen 10 Can be made particularly excellent (the viewing angle at which an image projected on the screen can be suitably viewed can be made particularly large). The light diffusing section 5 has a configuration in which a diffusing material 51 is dispersed in a substantially transparent material (for example, acrylic resin, polycarbonate resin, etc.) excellent in light transmittance. As the diffusing material 51, for example, fine particle (bead-shaped) silica, glass, resin, or the like can be used. Although the average particle diameter of the diffusing material 51 is not particularly limited, it is preferably 1 to 50 μm, and more preferably 2 to 10 μm.

  The light diffusing portion 5 is provided at least in a portion corresponding to the opening 41 of the black matrix 4, and a portion corresponding to the opening 41 is formed as a protruding protrusion protruding to the emission side. Thus, when the light diffusion part 5 has a protruding part, the light utilization efficiency can be made particularly excellent. More specifically, when the light diffusion part is formed with a uniform thickness on the light emission side from the black matrix, the probability that the light (photon) collides with the diffusion material in the light diffusion part. (Frequency) is likely to extinguish due to high frequency, and the light (photon) incident in the light diffusing part is likely to return to the incident side again, so that the light utilization efficiency is low. If the light diffusing portion 5 has a protrusion at a portion corresponding to the opening 41, the light (photons) incident on the light diffusing portion 5 excessively collides with the diffusing material 51, resulting in significant quenching. The light (photons) collected by the microlens 32 can be effectively prevented from returning to the light incident side, and the light incident on the light diffusion portion 5 can be diffused to the output side. . As a result, the viewing angle characteristics of the transmission screen 10 (transmission screen member 1) can be excellent. Moreover, when it has such a protrusion part, it has the area | region where the height of the light-diffusion part 5 is comparatively low between the adjacent protrusion part-protrusion parts, or the area | region in which the light-diffusion part 5 is not formed. (In the configuration shown in the figure, the light diffusion portion 5 is not formed between the adjacent protrusions). Thereby, the function of the black matrix (light shielding layer) 4 can be more effectively exhibited, and the contrast of the image projected on the screen can be made particularly excellent. Even in the case where the light diffusing portion having a uniform thickness is provided on the light emission side from the black matrix, the height (thickness) of the light diffusing portion is reduced (for example, 1 μm or less) as described above. However, in such a case, it is difficult to sufficiently diffuse the light incident on the light diffusion portion.

  The ratio of the area occupied by the protrusions (projected area) in the effective region where the microlenses 32 are formed when the transmissive screen member 1 is viewed in plan is preferably 5 to 99%. It is more preferably -95%, and further preferably 30-70%. When the proportion of the area occupied by the protrusions is within the above range, the light use efficiency of the transmission screen can be further improved. Further, the contrast of the projected image can be further improved. On the other hand, if the ratio of the area occupied by the protrusions is less than the lower limit value, it becomes difficult to sufficiently diffuse the light incident on the light diffusion part 5, and it becomes difficult to obtain sufficient viewing angle characteristics. there is a possibility. Moreover, when the ratio of the area which a protrusion part occupies exceeds the said upper limit, it will become easy to generate | occur | produce quenching inside the light-diffusion part 5 (protrusion part), and the utilization efficiency of light will fall. Further, when the ratio of the area occupied by the protrusions exceeds the upper limit value, the light use efficiency decreases, and the surface of the black matrix 4 (a region other than the opening 41) when viewed in plan from the light emission side. Among these, since the ratio occupied by the region covered with the light diffusion portion 5 (protrusion portion) increases, the contrast of the image projected on the screen tends to decrease. Thus, the area of the opening 41 and the projected area of the protrusion formed so as to correspond to each opening 41 are substantially equal (the area of the portion covering the black matrix 4 is small). preferable. More specifically, the area occupied by the opening 41 (projected area) in the effective area where the microlenses 32 are formed when the transmission screen member 1 is viewed in plan (from the direction shown in FIG. 2). It is preferable that the relationship of 0.2 ≦ A / B ≦ 1.55 is satisfied, where A is the ratio of A [%], and the ratio of the area occupied by the protrusion (projected area) is B [%]. It is more preferable that the relationship of 5 ≦ A / B ≦ 1.2 is satisfied. Thereby, the effect mentioned above becomes further remarkable. Further, according to a method as described later (a method for producing a transmissive screen member of the present invention), the transmissive screen member 1 satisfying such conditions can be obtained relatively easily.

  In the configuration shown in the drawing, a plurality of light diffusion portions 5 are provided. That is, a plurality of light diffusion portions 5 are provided independently of each other so as to correspond to each opening 41 of the black matrix 4 (selectively provided so as to correspond to each opening 41). ). As described above, when the plurality of light diffusion portions 5 are provided independently of each other, the light use efficiency can be made particularly excellent, and the contrast of the image projected on the screen is particularly excellent. Can be. More specifically, when a plurality of light diffusing portions 5 are provided independently of each other, the light (photons) incident on the light diffusing portion 5 excessively collides with the diffusing material 51, so that the quenching becomes remarkable. In addition, the light (photons) collected by the microlens 32 is more effectively prevented from returning to the light incident side, and the light incident on the light diffusion unit 5 is diffused to the output side. Can do. As a result, the light utilization efficiency can be made particularly excellent, and the viewing angle characteristics of the transmission screen 10 (transmission screen member 1) can be made excellent. In addition, when the plurality of light diffusion portions 5 are provided independently of each other, a region where the black matrix 4 is not covered with the light diffusion portion 5 is formed between the adjacent light diffusion portions 5 to 5. It will have. Thereby, the function of the black matrix (light shielding layer) 4 can be more effectively exhibited, and the contrast of the image projected on the screen can be made particularly excellent.

  The ratio of the area occupied by the light diffusion portion 5 in the effective region where the microlenses 32 are formed when the transmission screen member 1 is viewed in plan is preferably 5 to 99%, and more preferably 5 to 95%. More preferably, it is more preferably 30 to 70%. When the ratio of the area (projected area) occupied by the light diffusing unit 5 is a value within the above range, the viewing angle characteristics and light utilization efficiency of the transmissive screen can be further improved and projected. The contrast of the image can be made particularly excellent. On the other hand, if the proportion of the area occupied by the light diffusion portion 5 is less than the lower limit value, it becomes difficult to sufficiently diffuse the light incident on the light diffusion portion 5 and it is difficult to obtain sufficient viewing angle characteristics. There is a possibility. Moreover, if the ratio of the area which the light-diffusion part 5 occupies exceeds the said upper limit, it will become easy to generate | occur | produce quenching within the light-diffusion part 5, and the utilization efficiency of light will fall. Moreover, when the ratio of the area which the light-diffusion part 5 occupies exceeds the said upper limit, while using efficiency of light falls, it is a light-diffusion part among the surfaces of the black matrix 4 when planarly viewed from the light emission side. Since the ratio of the area covered with 5 increases, the contrast of the image projected on the screen tends to decrease. Thus, the area of the opening 41 and the projected area of the light diffusion part 5 formed so as to correspond to each opening 41 are substantially equal (the area of the portion covering the black matrix 4 is small). Is preferred. More specifically, the area occupied by the opening 41 (projected area) in the effective area where the microlenses 32 are formed when the transmission screen member 1 is viewed in plan (from the direction shown in FIG. 2). It is preferable that the relationship of 0.2 ≦ A / C ≦ 1.5 is satisfied, where A [%] and the ratio of the area occupied by the light diffusion portion 5 (projected area) are C [%], It is more preferable to satisfy the relationship of 0.5 ≦ A / C ≦ 1.2. Thereby, the effect mentioned above becomes further remarkable. Further, according to a method as described later (a method for producing a transmissive screen member of the present invention), the transmissive screen member 1 satisfying such conditions can be obtained relatively easily.

  As described above, in the present embodiment, the focal point f of the microlens 32 is designed to be positioned on the exit side of the black matrix 4, but the focal point f of the microlens 32 is shown in FIG. 3 and 10 are also preferably present in the light diffusing portion 5, and the light diffusing portion 5 in the direction perpendicular to the main surface of the transmissive screen member 1 is preferably present. More preferably, it is approximately in the center. Thereby, since the light incident in the light diffusing unit 5 can collide with the diffusing material 51 at an appropriate frequency, the light incident in the light diffusing unit 5 is more effectively prevented from being quenched. However, the light can be diffused efficiently. Therefore, the light use efficiency of the transmissive screen member 1 (transmissive screen 10) can be further improved. Moreover, since the light reflected by the light diffusion part 5 is diffused around the light diffusion part 5, a wider viewing angle can be obtained.

It is preferable that the top part of the light diffusion part 5 (projection part) corresponds to the optical axis of each microlens. Thereby, the light condensed by the microlens 32 is diffused almost isotropically by the light diffusing unit 5, and good viewing angle characteristics can be obtained.
Further, the height (length in the direction perpendicular to the main surface of the transmissive screen member 1) h of the light diffusion portion 5 is as shown in FIG. 1 (the same applies to FIGS. 3 and 10 described later), It is preferable that the thickness is larger than the thickness of the black matrix (light shielding layer) 4. In other words, it is preferable that the light diffusion portion 5 protrudes more toward the light emission side than the black matrix 4. The specific value of the height (the length in the direction perpendicular to the main surface of the transmissive screen member 1) h of the light diffusion portion 5 is preferably 2 to 450 μm, and preferably 2 to 250 μm. More preferably, it is 5-50 micrometers. Thereby, the quenching by the light reflected by the light diffusion part 5 returning to the incident side is surely prevented, and high light utilization efficiency can be obtained.

Next, the transmissive screen 10 including the transmissive screen member 1 as described above will be described.
As shown in FIG. 3, the transmission screen 10 includes the Fresnel lens portion 2 and the transmission screen member 1 described above. The Fresnel lens unit 2 is installed on the light (image light) incident side, and light transmitted through the Fresnel lens unit 2 is incident on the transmissive screen member 1.

The Fresnel lens unit 2 has a prism-shaped Fresnel lens 21 formed on the exit side surface in a substantially concentric shape. The Fresnel lens unit 2 refracts image light from a projection lens (not shown) to produce parallel light La parallel to the vertical direction of the main surface of the transmissive screen member 1.
In the transmissive screen 10 configured as described above, the image light from the projection lens is refracted by the Fresnel lens unit 2 to become parallel light La. The parallel light La is collected by each microlens 32 of the microlens substrate 3, passes through each opening 41 of the black matrix 4, and enters the light diffusion unit 5. The light incident on the light diffusing unit 5 is focused and diffused at a substantially central portion of the light diffusing unit 5 and is observed as a planar image by the observer.

Next, an example of the manufacturing method of the transmission screen member 1 described above will be described.
4 is a schematic longitudinal sectional view showing a substrate with concave portions for microlenses (substrate with concave portions) used for manufacturing a microlens substrate, and FIG. 5 shows a method for manufacturing the substrate with concave portions for microlenses shown in FIG. It is a typical longitudinal section. 6 to 8 are schematic longitudinal sectional views showing an example of a method for producing the transmission screen member shown in FIG. In the following description, the lower side in FIGS. 6 to 8 is referred to as “(light) incident side” and the upper side is referred to as “(light) emission side”.

First, prior to the description of the manufacturing method of the transmission screen member of the present invention, the configuration of the substrate with concave portions for microlens that can be used for manufacturing the microlens substrate and the manufacturing method thereof will be described.
As shown in FIG. 4, the substrate 6 with concave portions for microlenses has a plurality of concave portions (recesses for microlenses) 61 arranged at random.

By using such a substrate 6 with concave portions for microlenses, the microlens substrate 3 on which the microlenses 32 are randomly arranged as described above can be obtained.
In the present specification, “optically random” means that the arrangement of the microlenses is irregular and disturbed to the extent that the occurrence of optical interference such as moire is sufficiently prevented and suppressed.

Next, a manufacturing method of the substrate with concave portions for microlenses will be described with reference to FIG. In practice, a large number of microlens recesses are formed on the substrate. Here, in order to make the explanation easy to understand, a part thereof is shown in an emphasized manner.
First, when manufacturing the substrate 6 with concave portions for microlenses, a substrate 7 is prepared.
The substrate 7 having a uniform thickness and having no deflection or scratches is preferably used. The substrate 7 is preferably one whose surface is cleaned by washing or the like.

  Examples of the material of the substrate 7 include soda glass, crystalline glass, quartz glass, lead glass, potassium glass, borosilicate glass, and alkali-free glass. Among them, soda glass, crystalline glass (for example, neo-serum), Alkali-free glass is preferred. Soda glass, crystalline glass, and alkali-free glass are easy to process, are relatively inexpensive, and are advantageous from the viewpoint of manufacturing cost.

<A1> As shown in FIG. 5A, a mask 8 is formed on the surface of the prepared substrate 7 (mask forming step). At the same time, a back surface protective film 89 is formed on the back surface of the substrate 7 (the surface opposite to the surface on which the mask 8 is formed). Of course, the mask 8 and the back surface protective film 89 can be formed simultaneously.
The mask 8 is preferably one that can form an initial hole 81 to be described later by laser light irradiation or the like and has resistance to etching in an etching step to be described later. In other words, the mask 8 is preferably configured so that the etching rate is substantially equal to or smaller than that of the substrate 7.

From this point of view, the material constituting the mask 8 is, for example, a metal such as Cr, Au, Ni, Ti, Pt, an alloy containing two or more selected from these, an oxide of the metal (metal oxide) ), Silicon, resin and the like. The mask 8 may have a laminated structure of a plurality of layers made of different materials such as Cr / Au or Cr / Cr oxide.
The method for forming the mask 8 is not particularly limited, but when the mask 8 is made of a metal material (including an alloy) such as Cr or Au, or a metal oxide (for example, Cr oxide), the mask 8 may be formed by, for example, vapor deposition or sputtering It can be suitably formed by a method or the like. When the mask 8 is made of silicon, the mask 8 can be suitably formed by, for example, a sputtering method or a CVD method.

  When the mask 8 is mainly composed of Cr oxide or Cr, the initial hole 81 can be easily formed in the initial hole forming process described later, and the substrate 7 is more reliably protected in the etching process described later. can do. Further, when the mask 8 is mainly composed of Cr oxide or Cr, for example, in the etching process described later, ammonium monohydrogen difluoride can be used as an etchant. Since ammonium monohydrogen difluoride is not a poisonous and deleterious substance, it can prevent the influence on the human body and the environment during work more reliably.

The thickness of the mask 8 varies depending on the material constituting the mask 8, but is preferably about 0.01 to 2.0 μm, and more preferably about 0.03 to 0.2 μm. If the thickness is less than the lower limit, the shape of the initial hole 81 formed in the initial hole forming step described later may be distorted. In addition, when wet etching is performed in an etching process described later, the masked portion of the substrate 7 may not be sufficiently protected. On the other hand, if the upper limit is exceeded, it will be difficult to form the initial hole 81 that penetrates in the initial hole forming step described later, and the mask 8 may be peeled off due to the internal stress of the mask 8 depending on the constituent material of the mask 8. It may be easier.
The back surface protective film 89 is for protecting the back surface of the substrate 7 in the subsequent steps. By this back surface protective film 89, erosion, deterioration, etc. of the back surface of the substrate 7 are preferably prevented. This back surface protective film 89 is made of, for example, the same material as that of the mask 8. For this reason, the back surface protective film 89 can be provided in the same manner as the mask 8 simultaneously with the formation of the mask 8.

<A2> Next, as shown in FIG. 5 (b), a plurality of initial holes 81, which serve as mask openings in the later-described etching, are randomly formed in the mask 8 (initial hole forming step).
The initial holes 81 may be formed by any method, but are preferably formed by a physical method or laser light irradiation. Thereby, the board | substrate with a recessed part for microlenses can be manufactured with sufficient productivity. In particular, a concave portion can be easily formed even on a substrate with a concave portion for a microlens having a large area.

  Examples of the physical method for forming the initial hole 81 include blasting such as shot blasting and sand blasting, etching, pressing, dot printer, tapping, rubbing, and the like. When the initial hole 81 is formed by blasting, the initial hole 81 can be efficiently formed in a shorter time even on the substrate 7 having a relatively large area (area of the region where the microlens 32 is to be formed).

When the initial hole 81 is formed by laser light irradiation, the type of laser light to be used is not particularly limited, but a ruby laser, a semiconductor laser, a YAG laser, a femtosecond laser, a glass laser, a YVO ₄ laser, a Ne- Examples include He laser, Ar laser, CO ₂ laser, and excimer laser. Moreover, you may use wavelengths, such as SHG of each laser, THG, and FHG. When the initial holes 81 are formed by laser light irradiation, the size of the formed initial holes 81, the interval between the adjacent initial holes 81, and the like can be controlled easily and accurately. Further, when the initial hole 81 is formed by laser light irradiation, by controlling the irradiation condition, only the initial hole 81 can be formed without forming the initial concave portion 71 as described later, The initial recess 71 having small variations in shape, size, and depth can be easily and reliably formed.

It is preferable that the formed initial holes 81 are formed evenly over the entire surface of the mask 8. In addition, the formed initial hole 81 is small enough to eliminate the flat surface of the surface of the substrate 7 and form the recess 61 with almost no gap when wet etching is performed in step <A3> described later. Are preferably arranged at a certain interval.
Specifically, for example, the shape of the formed initial hole 81 in a plan view is substantially circular, and the average diameter (diameter) is preferably 2 to 10 μm. The initial holes 81 are preferably formed on the mask 8 at a rate of 1,000 to 1,000,000 holes / cm ² , and are formed at a rate of 10,000 to 500,000 holes / cm ^2. More preferably. Needless to say, the shape of the initial hole 81 is not limited to a substantially circular shape.

  Further, when the initial hole 81 is formed in the mask 8, as shown in FIG. 5B, not only the mask 8 but also a part of the surface of the substrate 7 may be removed simultaneously to form the initial recess 71. Thereby, when etching is performed in an etching process described later, the contact area with the etching solution is increased, and erosion can be suitably started. Further, by adjusting the depth of the initial recess 71, the depth of the recess 61 (maximum lens thickness) can be adjusted. Although the depth of the initial recessed part 71 is not specifically limited, It is preferable to set it as 5 micrometers or less, and it is more preferable to set it as about 0.1-0.5 micrometer. When the initial hole 81 is formed by laser irradiation, the variation in depth of the plurality of initial recesses 71 formed together with the initial hole 81 can be more reliably reduced. Thereby, the variation of the depth of each recessed part 61 which comprises the board | substrate 6 with a recessed part for microlenses also becomes small, and the magnitude | size and the shape variation of each microlens 32 of the microlens board | substrate 3 finally obtained also become small. As a result, the variation in diameter, focal length, and lens thickness of each microlens 32 can be made particularly small, and the openings 41 and the light diffusion portions 5 of the black matrix 4 can be suitably formed in the steps described later. it can.

Further, not only the initial holes 81 are formed on the formed mask 8 by a physical method or laser light irradiation, but, for example, when the mask 8 is formed on the substrate 7, a predetermined pattern is previously formed on the substrate 7. It is also possible to form a defect on the mask 8 by forming a mask 8 on top of the foreign matter, and use the defect as the initial hole 81.
Thus, by forming the initial hole 81 in the mask 8 by a physical method or laser light irradiation, it is simpler and less expensive than the case where the opening is formed in the mask by a conventional photolithography method. Openings (initial holes 81) can be randomly formed in the mask 8. Further, according to a physical method or laser light irradiation, a large substrate can be easily processed.

<A3> Next, as shown in FIG. 5C, the substrate 7 is etched using the mask 8 in which the initial holes 81 are formed, and a large number of recesses 61 are randomly formed on the substrate 7 (etching). Process).
The etching method is not particularly limited, and examples thereof include wet etching and dry etching. In the following description, a case where wet etching is used will be described as an example.

  By performing etching (wet etching) on the substrate 7 covered with the mask 8 in which the initial holes 81 are formed, as shown in FIG. A number of recesses 61 are formed on the substrate 7 by etching. As described above, since the initial holes 81 formed in the mask 8 are random, the formed recesses 61 are randomly arranged on the surface of the substrate 7.

In the present embodiment, when the initial hole 81 is formed in the mask 8 in the step <A2>, the initial recess 71 is formed on the surface of the substrate 7. Thereby, at the time of etching, the contact area with the etching solution is increased, and erosion can be suitably started.
Further, when the wet etching method is used, the concave portion 61 can be suitably formed. If, for example, an etchant (hydrofluoric acid-based etchant) containing hydrofluoric acid (hydrogen fluoride) is used as the etchant, the substrate 7 can be etched more selectively, and the recesses 61 are preferably formed. can do.

When the mask 8 is mainly composed of Cr, an ammonium fluoride solution (ammonium monofluoride solution) is particularly suitable as the hydrofluoric acid etching solution. Since the ammonium fluoride solution (4 wt% or less) is not a poisonous or deleterious substance, it can prevent the human body and the environment from being affected during work. Further, when an ammonium fluoride solution is used as the etching solution, the etching solution may contain, for example, hydrogen peroxide. Thereby, the etching speed can be further increased.
In addition, wet etching can be performed with a simpler apparatus than dry etching, and more substrates can be processed at one time. Thereby, productivity improves and the board | substrate 6 with a concave part for microlenses can be provided cheaply.

<A4> Next, as shown in FIG. 5D, the mask 8 is removed (mask removal step). At this time, the back surface protective film 89 is also removed together with the removal of the mask 8.
When the mask 8 is mainly composed of Cr, the removal of the mask 8 can be performed by, for example, etching using a mixture containing ceric ammonium nitrate and perchloric acid.

As described above, as shown in FIG. 5D and FIG. 4, the substrate 6 with concave portions for microlenses in which a large number of concave portions 61 are randomly formed on the substrate 7 is obtained.
The recess 61 is preferably formed relatively densely. Specifically, when the substrate 6 with concave portions for microlenses is viewed in plan, the proportion of the area occupied by the concave portions 61 in the effective region where the concave portions 61 are formed is preferably 90% or more, and 96% or more. It is more preferable that Thereby, the microlens substrate 3 as described above can be suitably obtained.

The method for forming the random recesses 61 on the substrate 7 is not particularly limited, but the method as described above (the initial hole 81 is formed in the mask 8 by a physical method or laser light irradiation, and then the mask 8 is formed. The following effects are obtained when it is formed by etching using the method of forming the recess 61 on the substrate 7).
That is, by forming the initial hole 81 in the mask 8 by a physical method or laser light irradiation, the mask 8 can be formed in the mask 8 more easily and cheaply than in the case where the opening is formed in the mask by a conventional photolithography method. The opening (initial hole 81) can be formed in a predetermined pattern. Thereby, productivity improves and the board | substrate 6 with a concave part for microlenses can be provided cheaply.

Further, according to the method as described above, it is possible to easily perform processing on a large substrate. In the case of manufacturing a large substrate, it is not necessary to bond a plurality of substrates as in the prior art, and the seam of bonding can be eliminated. As a result, a high-quality substrate with a concave portion for a large microlens (microlens substrate) can be manufactured at a low cost by a simple method.
Further, after removing the mask 8 in the step <A4>, a new mask may be formed on the substrate 7, and a series of steps of mask formation-initial hole formation-wet etching-mask removal may be repeated. Thereby, the board | substrate 6 with a recessed part for microlenses in which the recessed part 61 was formed densely can be obtained.

Next, as an example of the method for manufacturing the transmission screen member of the present invention, a method for manufacturing the transmission screen member 1 using the above-described substrate 6 with concave portions for microlenses will be described.
<B1> First, as shown in FIG. 6A, unpolymerized (uncured) resin 33 is applied to the surface of the substrate 6 with concave portions for microlenses where the concave portions 61 are formed. In the present embodiment, in this step, the spacer 9 is arranged in a region where the concave portion 61 of the substrate 6 with concave portions for microlenses is not formed, and the resin 33 is pressed by the flat plate 11. Thereby, the thickness of the microlens substrate 3 to be formed can be controlled more reliably, and the position of the focal point of the microlens 32 in the finally obtained transmission screen member 1 can be controlled more reliably. can do.

When the spacer 9 is used as in the present embodiment, the shape of the spacer 9 is not particularly limited, but is preferably substantially spherical or substantially cylindrical. When the spacer 9 has such a shape, the diameter is preferably 10 to 300 μm, more preferably 30 to 200 μm, and further preferably 30 to 170 μm.
Prior to the application of the resin 33 and the pressing on the flat plate 11, the release agent is applied to the surface on the side where the concave portion 61 of the substrate 6 with concave portions for microlenses is formed or the surface on the side pressing the resin 33 of the flat plate 11. May be applied. Thereby, the microlens board | substrate 3 can be isolate | separated (peeled) easily and reliably from the board | substrate 6 with a concave part for microlenses and the flat plate 11 in the process mentioned later.

<B2> Next, the resin 33 is cured (polymerized), and then the flat plate 11 is removed (see FIG. 6B). As a result, the microlens substrate 3 including the resin layer 31 and the microlens 32 made of the resin filled in the concave portion 61 and functioning as a convex lens is obtained.
The method for curing (polymerizing) the resin 33 is not particularly limited, and examples thereof include irradiation with light such as ultraviolet rays, irradiation with electron beams, and heating.

<B3> Next, the black matrix 4 is formed on the emission side surface of the microlens substrate 3 manufactured as described above.
First, as shown in FIG. 6C, the first layer 42 is formed by applying a light-shielding first material containing a positive type photopolymer to the emission side surface of the microlens substrate 3. . Examples of the method for applying the first material to the surface of the microlens substrate 3 include various coating methods such as dip coating, doctor blade, spin coating, brush coating, spray coating, electrostatic coating, electrodeposition coating, roll coater, etc. Can be used. The first material may be composed of a light-shielding resin (photopolymer), or a light-shielding material dispersed or dissolved in a resin material (low light-shielding property). Also good. After application of the first material (after formation of the first layer 42), for example, heat treatment such as pre-bake treatment may be performed as necessary.

  <B4> Next, as shown in FIG. 7D, the microlens substrate 3 is irradiated with the exposure light Lb in the direction perpendicular to the incident-side surface. The irradiated exposure light Lb is condensed by passing through each microlens 32. As a result, the first layer 42 in the vicinity of the focal point f of the microlens 32 (at the portion where the condensed light is incident) is exposed, and the first layer 42 in other portions is not exposed or the exposure amount. , And only the first layer 42 (positive photopolymer) near the focal point f is exposed.

Thereafter, development is performed. Here, since the first layer 42 contains a positive type photopolymer, the first layer 42 in the vicinity of the exposed focal point f is dissolved and removed by development. As a result, as shown in FIG. 7E, the black matrix 4 in which the opening 41 is formed in the portion corresponding to the optical axis L of the microlens 32 is formed. The development method varies depending on the composition of the first material (constituting material of the first layer) and the like, but can be performed using, for example, an alkaline solution such as an aqueous KOH solution.
Further, after development, for example, a heat treatment such as a post-bake treatment may be performed as necessary.

<B5> Next, the light diffusion portion 5 is formed in a portion corresponding to the opening 41 of the black matrix 4 formed in this way.
First, as shown in FIG. 7F, the second material 53 is applied to the surface on which the black matrix 4 is formed to form the second layer 53. The second material includes at least a negative photopolymer, and in this embodiment, the diffusion material 51 is dispersed in the photopolymer 52. As a method for applying the second material, for example, various coating methods such as dip coating, doctor blade, spin coating, brush coating, spray coating, electrostatic coating, electrodeposition coating, and roll coater can be used.

As the negative photopolymer 52, for example, CSP-SO25 (manufactured by Fuji Film Arch Co., Ltd.) can be used.
Moreover, as the diffusing material 51, for example, fine particle (bead-shaped) silica, glass, resin, or the like can be used. Although the average particle diameter of the diffusing material 51 is not particularly limited, it is preferably 1 to 50 μm, and more preferably 2 to 10 μm. After application of the second material (after formation of the second layer 53), for example, heat treatment such as pre-bake treatment may be performed as necessary.

  <B6> Next, as shown in FIG. 8G, the microlens substrate 3 is irradiated with exposure light Lc in a direction perpendicular to the incident-side surface. The irradiated exposure light Lc is condensed by passing through each microlens 32 and forms a focal point f at a position corresponding to the optical axis L of each microlens 32. As a result, the second layer 53 in the vicinity of the focal point f is exposed, and the second layer 53 in other portions is not exposed or the exposure amount is reduced, and the second layer 53 in the vicinity of the focal point f (photograph) is exposed. Only polymer 52) is exposed.

Thereafter, development is performed. Here, since the photopolymer 52 is a negative type, the photopolymer 52 other than the vicinity of the exposed focal point f is dissolved and removed by development. As a result, as shown in FIG. 8 (h), the light diffusion portion 5 is formed in the portion corresponding to the optical axis L of the microlens 32, that is, the portion corresponding to the opening 41 of the black matrix 4.
Thus, in the present invention, the light condensed by the lens unit (microlens) is irradiated to the second layer made of a material containing a negative photopolymer, and exposure is performed by the condensed light. It is characterized in that a light diffusion part is formed by developing so as to leave the part that has been formed. As a result, a transmission screen (transmission screen member) excellent in viewing angle characteristics and light utilization efficiency can be obtained easily and reliably. More specifically, the light diffusion layer can be selectively formed at a portion corresponding to the opening of the light shielding layer (black matrix) by performing exposure using light condensed by the lens portion. As a result, in the obtained transmission screen (transmission screen member), the light condensed by the lens unit can be efficiently diffused to the emission side while effectively preventing quenching in the light diffusion unit. And viewing angle characteristics and light utilization efficiency can be improved. In addition, according to the present invention, the light diffusing portion 5 can be easily and reliably formed so that the portion corresponding to the opening 41 is a protruding portion that protrudes toward the light emission side, as in the illustrated configuration. it can. Further, according to the present invention, as in the configuration shown in the figure, the plurality of light diffusion portions 5 can be easily and reliably formed at the portions corresponding to the respective openings 41 so as to be independent from each other.

In addition, you may perform heat processing, such as a post-baking process after development, as needed.
Moreover, when irradiating the microlens substrate 3 with exposure light, for example, the positional relationship between the light source of the exposure light and the microlens substrate 3 may be changed over time. That is, the light source and the microlens substrate 3 may be relatively moved while irradiating the exposure light. Thereby, for example, even if the light diffusion portion 5 to be formed is relatively large, the light diffusion portion 5 can be formed efficiently.

<B7> Thereafter, the transmissive screen member 1 is obtained by removing the substrate 6 with concave portions for microlenses (see FIG. 8I). Thus, by removing the substrate 6 with concave portions for microlenses, the substrate 6 with concave portions for microlenses can be repeatedly used in the manufacture of the transmission type screen member 1, and in terms of manufacturing cost and manufactured transmission type. It is preferable from the viewpoint of the quality stability of the screen member 1.
The microlens recessed substrate 6 does not necessarily have to be removed. In other words, the transmissive screen 10 may include the substrate 6 with a microlens recess.

  As described above, in the manufacturing method of the present embodiment, the black matrix and the light diffusing portion are formed by irradiating the photopolymer with the exposure light condensed by the microlens. The black matrix (light-shielding layer) 4 and the light diffusion portion 5 can be efficiently formed, and the opening 41 and the light diffusion portion 5 can be selectively formed (provided) with excellent positional accuracy. Therefore, the obtained transmissive screen member 1 (transmissive screen 10) has excellent viewing angle characteristics and light utilization efficiency. Moreover, according to the above method, the area | region where the height of the light-diffusion part 5 is comparatively low between adjacent protrusion parts-protrusion part, or the area | region in which the light-diffusion part 5 is not formed (adjacent light-diffusion part 5 A region in which the light diffusion portion 5 is not formed can be provided between the light diffusion portions 5. Thereby, the function of the black matrix (light shielding layer) 4 can be more effectively exhibited, and the contrast of the image projected on the screen can be made particularly excellent.

  When each microlens 32 of the microlens substrate 3 has substantially the same radius of curvature, the light collected by each microlens 32 is focused on substantially the same plane. Therefore, by uniformly irradiating the incident side surface of the microlens with the exposure light, the opening of the black matrix (light-shielding layer) and the light diffusion portion can be formed with substantially the same dimensions.

A rear projector using the transmission screen will be described below.
FIG. 9 is a diagram schematically showing the configuration of the rear projector of the present invention.
As shown in the figure, the rear projector 300 has a configuration in which a projection optical unit 310, a light guide mirror 320, and a transmissive screen 10 are arranged in a housing 340.
Since the rear projector 300 uses the transmissive screen 10 having excellent viewing angle characteristics and light utilization efficiency as the transmissive screen 10, the rear projector 300 is an excellent rear projector with good display quality.

In particular, in the transmissive screen member 1 described above, since the microlenses 32 are randomly arranged (optically random), the rear projector 300 hardly causes problems such as moire.
As mentioned above, although the manufacturing method of the member for transmissive screens of this invention, the member for transmissive screens, the transmissive screen, and the rear projector were demonstrated based on embodiment of illustration, this invention is limited to these. is not.

For example, each component constituting the transmissive screen member, the transmissive screen, and the rear projector can be replaced with any configuration that can exhibit the same function.
In the above-described embodiment, the microlens (lens unit) 32 is described as being focused on the light emission side of the black matrix (light-shielding layer) 4. However, the focus of the lens unit is, for example, light from the light-shielding layer. May be on the incident side (see FIG. 10).

In the above-described embodiment, the microlens substrate (lens substrate) 3 has been described as being manufactured using the substrate 6 with the concave portion for microlenses. However, any lens substrate (any method) can be used. May be used).
In the above-described embodiment, the initial hole forming step of the method for manufacturing the microlens recessed substrate is described as forming the initial recessed portion 71 in the substrate 7 together with the initial hole 81. May not be formed. By appropriately adjusting the conditions for forming the initial hole 81 (for example, the laser energy intensity, the beam diameter, the irradiation time, etc.), the initial recess 71 having a desired shape is formed or the initial hole 71 is not formed. Only 81 can be selectively formed.

  In the above-described embodiment, the black matrix (light-shielding layer) 4 and the light diffusion portion 5 are formed in a state where the substrate 6 with concave portions for microlenses is in close contact with the microlens substrate 3. The matrix (light-shielding layer) 4 and the light diffusion part 5 may be formed, for example, in a state where the microlens substrate 3 with concave portions for microlenses is removed from the microlens substrate 3.

In the above-described embodiment, the microlenses having a substantially circular shape when viewed in plan are described as randomly arranged. However, the shape and arrangement of the microlens are not limited to this. For example, the microlenses may be arranged in a lattice shape or may be formed in a honeycomb shape.
In the embodiment described above, the transmission screen is described as including the transmission screen member and the Fresnel lens. However, the transmission screen of the present invention does not necessarily include the Fresnel lens. Good. For example, the transmission screen of the present invention may be substantially constituted only by the transmission screen member of the present invention.

  In the above-described embodiment, the configuration including the microlens as the lens unit has been described. However, the lens unit is not limited thereto, and may be a lenticular lens, for example. By using a lenticular lens, the manufacturing process of the lens portion can be simplified, and the productivity of the transmission screen can be improved. When a lenticular lens is used as the lens portion, a striped light shielding layer (black stripe) is formed instead of the black matrix. And a light-diffusion part is provided in the part corresponding to between each band which comprises a black stripe at least. Even in such a configuration, the same operation and effect as in the above-described embodiment can be obtained. That is, according to the present invention, since the light incident on the light diffusing portion can be efficiently directed toward the light emitting side while sufficiently diffusing, even if the lens portion has a lenticular lens. Excellent viewing angle characteristics can be obtained (both viewing angles in the vertical and horizontal directions can be increased).

Further, in the above-described embodiment, the light diffusing unit is entirely formed as a projecting portion, that is, the light diffusing unit is substantially composed of only the projecting portion. It may have a region other than the portion (see FIG. 10).
In the embodiment described above, the microlens recessed substrate 6 is removed after the light diffusing portion 5 is formed. However, the microlens recessed substrate 6 is formed with the black matrix 4 and the light diffusing portion 5 formed. It may be removed before or may be incorporated in the transmissive screen 10 without being removed from the microlens substrate 3.

Example 1
A substrate with concave portions for microlenses having concave portions for microlenses was manufactured as follows, and a microlens substrate was manufactured using the substrate with concave portions for microlenses.
First, a soda glass substrate having a size of 1.2 m × 0.7 m square and a thickness of 4.8 mm was prepared as a substrate.

This soda glass substrate was immersed in a cleaning solution containing 4 wt% ammonium monohydrogen difluoride and 8 wt% hydrogen peroxide and etched by 6 μm to clean the surface.
Thereafter, cleaning with pure water and drying using N ₂ gas (removal of pure water) were performed.
Next, a Cr film having a thickness of 0.03 μm was formed on the soda glass substrate by sputtering. That is, a Cr film mask and a back surface protective film were formed on the surface of the soda glass substrate.

Next, laser processing was performed on the mask to form a large number of initial holes in a range of 113 cm × 65 cm at the center of the mask.
The laser processing was performed using a YAG laser under the conditions of an energy intensity of 1 mW, a beam diameter of 3 μm, and an irradiation time of 60 × 10 ⁻⁹ seconds.
Thereby, initial holes were formed in a random pattern over the entire range of the mask. The average diameter of the initial holes was 5 μm, and the formation density of the initial holes was 40,000 holes / cm ² .
At this time, a 0.1 μm deep recess and an altered layer were also formed on the surface of the soda glass substrate.

Next, the soda glass substrate was wet-etched to form a large number of recesses on the soda glass substrate. The formed many recesses had substantially the same radius of curvature (35 μm).
In the wet etching, an aqueous solution containing 4 wt% ammonium monohydrogen difluoride and 8 wt% hydrogen peroxide was used as an etchant, and the immersion time was 5 hours.

Next, the mask and the back surface protective film were removed by etching using a mixture of ceric ammonium nitrate and perchloric acid.
Thereafter, cleaning with pure water and drying using N ₂ gas (removal of pure water) were performed.
As a result, a wafer-like substrate with concave portions for microlenses in which a large number of concave portions for microlenses were randomly formed on a soda glass substrate was obtained. When the obtained substrate with recesses was viewed in plan, the ratio of the area occupied by the recesses in the effective region where the recesses were formed was 97%. In addition, a large number of distances between any two adjacent points (between the recesses and the recesses) of the substrate with recesses for the microlens were taken, and the standard deviation was obtained therefrom. The standard deviation thus determined was 35% of their average.

Next, a release agent (GF-6110) is applied to the surface of the substrate with concave portions for microlenses obtained as described above on which the concave portions are formed, and further, unpolymerized (uncured) ultraviolet rays. A curable resin (V-2403 (manufactured by Nippon Steel Chemical Co., Ltd.)) was applied. At this time, a substantially spherical spacer (diameter 150 μm) was arranged in a region where the concave portion of the substrate with concave portions for microlenses on the surface was not formed (ineffective lens region).
Next, the ultraviolet curable resin was pressed with a flat plate made of alkali-free glass. At this time, air was prevented from entering between the flat plate and the ultraviolet curable resin. Moreover, as a flat plate, the thing by which the mold release agent (GF-6110) was apply | coated to the surface at the side which presses an ultraviolet curable resin was used.

Then, the ultraviolet curable resin was hardened by irradiating ultraviolet rays of 10,000 mJ / cm ² from the flat plate to obtain a microlens substrate. The refractive index of the obtained microlens substrate (cured resin) was 1.5. The thickness of the resin layer of the obtained microlens substrate was 40 μm, the radius of curvature of the microlens was 35 μm, and the diameter of the microlens was 70 μm. Further, when the obtained microlens substrate was viewed in plan, the ratio of the area occupied by the microlens (projected area) in the effective region where the microlens was formed was 97%.

Next, the flat plate was removed.
Next, a light-shielding material (carbon black) and a positive type photopolymer (PC405G: manufactured by JSR Corporation) are formed on the surface of the emission side (surface opposite to the surface on which the microlens is formed) of the microlens substrate. The 1st material containing was applied with the roll coater, and the 1st layer was formed. The content of the light shielding material in the first material was 20 wt%.

Next, a pre-bake treatment at 90 ° C. for 30 minutes was performed.
Next, ultraviolet light as parallel light of 80 mJ / cm ² was irradiated from the surface opposite to the surface on which the concave portion of the substrate with concave portions for microlenses was formed. Thereby, the irradiated ultraviolet rays were collected by each microlens, and the first layer (photopolymer) near the focal point f of each microlens was selectively exposed.

Thereafter, development was performed for 40 seconds using a 0.5 wt% aqueous KOH solution.
Thereafter, pure water cleaning and drying using N ₂ gas (removal of pure water) were performed, and a post-baking treatment at 200 ° C. for 30 minutes was further performed. Thereby, a black matrix having openings corresponding to the respective microlenses was formed. The thickness of the formed black matrix was 2 μm, and the diameter of the opening was 45 μm.

  Thereafter, a second material containing a light diffusing material (silica beads having a diameter of 5 μm) and a negative type photopolymer (CSP-SO25 (manufactured by Fuji Film Arch Co., Ltd.)) on the surface on which the black matrix is formed. Was applied by a roll coater to form a second layer. The thickness of the formed second layer was 10 μm. The content of the light diffusing material in the second material was 25 wt%.

Next, a pre-bake treatment at 90 ° C. for 30 minutes was performed.
Next, ultraviolet rays as parallel light of 100 mJ / cm ² were irradiated from the surface opposite to the surface on which the concave portion of the substrate with concave portions for microlenses was formed. Thereby, the irradiated ultraviolet rays were collected by each microlens, and the second layer (photopolymer) near the focal point f of each microlens was selectively exposed.

Thereafter, development was performed for 40 seconds using CD-2000 (manufactured by Fuji Film Arch Co., Ltd.) as a developer.
Thereafter, pure water cleaning and drying using N ₂ gas (removal of pure water) were performed, and a post-baking treatment at 200 ° C. for 30 minutes was further performed. Thereby, the convex light-diffusion part was formed in the area | region corresponding to each opening part. The height of the formed light diffusion portion was 5 μm. In addition, the formed light-diffusion part becomes the protrusion part in its entirety, and a flat part (part whose surface is parallel to the emission surface of the microlens substrate) at a part lower than the top part of the protrusion part. Did not have.

Thereafter, the substrate with concave portions for microlenses was removed to obtain a transmissive screen member.
In the transmissive screen member thus obtained, when parallel light is incident from the surface on which the microlens is formed, the focus of the microlens is 3 μm from the surface on the emission side of the black matrix. It was the site of the side. In addition, in the effective region where the microlens is formed when the transmission screen member is viewed in plan, the ratio of the area (projection area) occupied by the light diffusion portion formed as the protruding portion is 70%. . Further, in the effective area where the microlens is formed when the transmission screen member is viewed in plan, the ratio of the area occupied by the opening (projection area) is 50%.
A transmissive screen as shown in FIG. 3 was obtained by assembling the transmissive screen member produced as described above and the Fresnel lens portion produced by extrusion molding.

(Example 2)
A transmissive screen was produced in the same manner as in Example 1 except that the mask and the back surface protective film were formed as Cr oxide films. Note that the mask and the back surface protective film were formed by sputtering. The thickness of the Cr oxide film was 0.03 μm.
Example 3
A transmissive screen was produced in the same manner as in Example 1 except that the mask and the back surface protective film were formed as a Cr / Cr oxide laminate (a laminate in which Cr oxide was laminated on the outer surface side of Cr). . Note that the mask and the back surface protective film were formed by sputtering. The thickness of the Cr layer was 0.02 μm, and the thickness of the Cr oxide layer was 0.02 μm.

Example 4
A transmissive screen was manufactured in the same manner as in Example 1 except that the mask and the back surface protective film were formed as a Cr oxide / Cr laminate (a laminate in which Cr was laminated on the outer surface side of Cr oxide). . Note that the mask and the back surface protective film were formed by sputtering. The thickness of the Cr oxide layer was 0.02 μm, and the thickness of the Cr layer was 0.02 μm.

(Comparative Example 1)
Using the substrate with concave portions for microlenses manufactured in Example 1, a microlens substrate was produced by the same method as described above.
Next, the flat plate used for pressing the ultraviolet curable resin is removed, and a composition in which carbon black as a light-shielding material is dispersed in PC-403 (JSR Corporation) on the surface of the exposed microlens substrate is rolled. The composition was applied by a coater and then heat-treated at 90 ° C. for 30 minutes to form a light-shielding film (light-shielding film).

  Thereafter, a mask is formed and etched by photolithography (by irradiating a predetermined pattern of light from the surface of the microlens substrate on which the light-shielding film is formed), and then 200 ° C. × 60 minutes. By performing heat treatment and curing the composition, a black matrix having openings at portions corresponding to the microlenses of the coating was formed. The thickness of the formed black matrix was 2 μm, and the diameter of the opening was 45 μm.

Next, a composition in which a diffusing material (silica beads having a diameter of 5 μm) is dispersed in CSP-S025 is applied to the entire surface on which the black matrix is formed by a roll coater, and then 200 ° C. × 60 minutes. By applying a heat treatment, the composition was cured to form a layered light diffusion portion. The formed light diffusion part (light diffusion layer) had a thickness of 6 μm.
Thereafter, the substrate with concave portions for microlenses was removed to obtain a transmissive screen member.
A transmissive screen was obtained by assembling the transmissive screen member manufactured as described above and the Fresnel lens portion produced by extrusion molding.

(Comparative Example 2)
First, a soda glass substrate having a size of 1.2 m × 0.7 m square and a thickness of 4.8 mm was prepared as a substrate.
This soda glass substrate was immersed in a cleaning solution containing 4 wt% ammonium monohydrogen difluoride and 8 wt% hydrogen peroxide and etched by 6 μm to clean the surface.
Thereafter, cleaning with pure water and drying using N ₂ gas (removal of pure water) were performed.

Next, a Cr film having a thickness of 0.03 μm was formed on the soda glass substrate by sputtering. That is, a Cr film mask and a back surface protective film were formed on the surface of the soda glass substrate.
Next, laser processing was performed on the mask to form a large number of linear grooves (holes) in a range of 113 cm × 65 cm in the central portion of the mask so as to be parallel to each other. The pitch between adjacent grooves was 70 μm.

The laser processing was performed using a YAG laser under the conditions of an energy intensity of 1 mW, a beam diameter of 3 μm, and an irradiation time of 60 × 10 ⁻⁹ seconds. Next, wet etching was performed on the soda glass substrate to form a groove-shaped recess on the soda glass substrate. The formed recesses had substantially the same radius of curvature (35 μm).
In the wet etching, an aqueous solution containing 4 wt% ammonium monohydrogen difluoride and 8 wt% hydrogen peroxide was used as an etchant, and the immersion time was 5 hours.

Next, the mask and the back surface protective film were removed by etching using a mixture of ceric ammonium nitrate and perchloric acid.
Thereafter, cleaning with pure water and drying using N ₂ gas (removal of pure water) were performed.
Thus, a wafer-like substrate with concave portions for lenticular lenses in which a large number of concave portions (groove portions) for lenticular lenses were formed on a soda glass substrate was obtained.

  Next, a mold release agent (GF-6110) is applied to the surface on which the concave portion of the substrate with concave portions for lenticular lenses obtained as described above is formed, and further, unpolymerized (uncured) ultraviolet rays. A curable resin (V-2403 (manufactured by Nippon Steel Chemical Co., Ltd.)) was applied. Under the present circumstances, the substantially spherical spacer (diameter 30 micrometers) was distribute | arranged to the area | region where the recessed part of the board | substrate with a concave part for lenticular lenses of the said surface is not formed.

Next, the ultraviolet curable resin was pressed with a flat plate made of alkali-free glass. At this time, air was prevented from entering between the flat plate and the ultraviolet curable resin. Moreover, as a flat plate, the thing by which the mold release agent (GF-6110) was apply | coated to the surface at the side which presses an ultraviolet curable resin was used.
Then, the ultraviolet curable resin was hardened by irradiating ultraviolet rays of 10,000 mJ / cm ² from the flat plate to obtain a lenticular lens substrate. The refractive index of the obtained lenticular lens substrate (cured resin) was 1.5. Moreover, the thickness of the resin layer of the obtained lenticular lens substrate was 150 μm, and the radius of curvature of the lenticular lens was 35 μm.

  Next, the flat plate used for pressing the ultraviolet curable resin is removed, and carbon black as a light-shielding material is applied to the exposed surface of the lenticular lens substrate (the surface on the side where the lenticular lens is formed). The composition dispersed in JSR Corporation) was applied by a roll coater, and then subjected to heat treatment at 200 ° C. for 60 minutes to cure the composition and form a light-shielding film (light-shielding film). .

  Then, by using a photolithography method (by irradiating a predetermined pattern of light from the surface of the lenticular lens substrate on which the light-shielding film is formed) to form and etch a mask, each lenticular lens of the film A black stripe (light-shielding layer) having an opening at a portion corresponding to is formed. The thickness of the formed black stripe was 2 μm, and the width of the opening was 35 μm.

Next, a composition in which a diffusing material (silica beads having a diameter of 5 μm) is dispersed in CSP-SO25 (manufactured by Fuji Film Arch Co., Ltd.) is applied to the entire surface on the side where the black stripe is formed by a roll coater. Thereafter, the composition was cured by heat treatment at 200 ° C. for 60 minutes to form a layered light diffusion portion. The formed light diffusion part (light diffusion layer) had a thickness of 40 μm.
Thereafter, the substrate with concave portions for the lenticular lens was removed to obtain a transmissive screen member.
A transmissive screen was obtained by assembling the transmissive screen member manufactured as described above and the Fresnel lens portion produced by extrusion molding.

[Evaluation of transmission screen]
The light utilization efficiency was measured for the transmissive screens produced in Examples 1 to 4 and Comparative Examples 1 and 2. The measurement of the light utilization efficiency was carried out with a spectrophotometer using an integrating sphere under the condition of measuring the ratio of the amount of light transmitted through the screen of each example and each comparative example to the amount of light without the screen. .
As a result, in each of the transmissive screens of Examples 1 to 4, an excellent light utilization efficiency of 70% was obtained. On the other hand, only 55% light utilization efficiency was obtained with the transmission screen of Comparative Example 1 and 52% with the transmission screen of Comparative Example 2.

[Production and evaluation of rear projector]
Using the transmission screens of Examples 1 to 4 and Comparative Examples 1 and 2, rear type projectors as shown in FIG. 9 were produced.
With the sample image displayed on the transmission screen of the obtained rear projector, the viewing angles in the vertical direction and the horizontal direction were measured.

The viewing angle was measured using a variable angle photometer (goniophotometer) under the condition of measuring at intervals of 5 degrees.
As a result, the rear projector provided with the transmissive screen obtained in Example 1 has an excellent viewing angle of 22 ° in the vertical direction (an angle at which the amount of light is halved) and 22 ° in the horizontal direction. It was confirmed to have viewing angle characteristics. Further, with this rear projector, a bright image was displayed, and no moiré was observed. Similar results were obtained for the rear projectors having the transmissive screens obtained in Examples 2 to 4.

On the other hand, satisfactory characteristics could not be obtained in the rear type projector including the transmissive screens of the comparative examples.
That is, in the rear projector provided with the transmissive screen obtained in Comparative Example 1, the vertical viewing angle is 18 ° and the horizontal viewing angle is 18 °, and the transmissive screen obtained in Comparative Example 2 is used. The rear-type projector provided with the inferior viewing angle characteristic has a vertical viewing angle of 8 ° and a horizontal viewing angle of 23 °. In the rear projectors of Comparative Examples 1 and 2, the image projected on the transmissive screen was darker than the rear projectors of the present invention (Examples 1 to 4).

It is a typical longitudinal section showing a suitable embodiment of a member for transmission type screens of the present invention. FIG. 2 is a plan view of a microlens substrate provided in the transmission screen member shown in FIG. 1. It is a typical longitudinal cross-sectional view which shows suitable embodiment of the transmission type screen of this invention provided with the member for transmission type screens shown in FIG. It is a typical longitudinal cross-sectional view which shows the board | substrate with a concave part for microlenses used for manufacture of a microlens board | substrate. It is a typical longitudinal cross-sectional view which shows the manufacturing method of the board | substrate with a recessed part for microlenses shown in FIG. It is a typical longitudinal cross-sectional view which shows an example of the manufacturing method of the member for transmission type screens shown in FIG. It is a typical longitudinal cross-sectional view which shows an example of the manufacturing method of the member for transmission type screens shown in FIG. It is a typical longitudinal cross-sectional view which shows an example of the manufacturing method of the member for transmission type screens shown in FIG. It is a figure which shows typically the rear type projector to which the transmission type screen of this invention is applied. It is a typical longitudinal cross-sectional view which shows other embodiment of the member for transmissive screens of this invention, and a transmissive screen.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Transmission type screen member 2 ... Fresnel lens part 21 ... Fresnel lens 3 ... Micro lens board | substrate (lens board | substrate) 31 ... Resin layer 32 ... Micro lens (lens part) 33 ... Resin 4 ... Black matrix (light-shielding layer) 41 ... Opening 42 ... 1st layer 5 ... Light diffusion part 51 ... Diffusing material 52 ... Photopolymer 53 ... 2nd layer 6 ... Substrate with concave part for microlenses 61 ... Recessed part 7 ... Substrate 71 ... Initial concave part 8 ... Mask 81 ... Initial hole 89 ... Back surface protective film 9 ... Spacer 10 ... Transmission type screen 11 ... Flat plate 300 ... Rear type projector 310 ... Projection optical unit 320 ... Light guide mirror 340 ... Case

Claims (21)

A lens substrate having a plurality of lens portions for condensing incident light;
A light-shielding layer formed on the light emission side from the lens unit and having an opening on the optical path of the light transmitted through the lens unit;
A method for manufacturing a transmissive screen member comprising a light diffusing part having a function of diffusing light transmitted through the lens part,
The light diffusing portion is made of a material containing a diffusing material,
A negative type photopolymer is included on the surface on which the light shielding layer is formed with respect to the lens substrate on which the light shielding layer is formed on the surface opposite to the surface on which the lens portion is formed. Applying a second material and forming a second layer;
Exposing the second layer by irradiating the second layer with light incident from the side of the lens substrate on which the lens portion is formed and condensed by the lens portion; ,
And a step of developing the light diffusion portion so that a portion exposed by the condensed light remains in the second layer, and forming the light diffusion portion. Production method. A lens substrate having a plurality of lens portions for condensing incident light;
A light-shielding layer formed on the light emission side from the lens unit and having an opening on the optical path of the light transmitted through the lens unit;
A method for manufacturing a transmissive screen member comprising a light diffusing part having a function of diffusing light transmitted through the lens part,
The light diffusing portion is made of a material containing a diffusing material,
Applying a first material containing a positive type photopolymer to a surface of the lens substrate opposite to a surface on which the lens portion is formed, and forming a first layer;
Exposing the first layer by irradiating the first layer with light incident from a surface side where the lens portion of the lens substrate is formed and condensing the light by the lens portion; ,
A step of developing the first layer to remove a portion exposed by the condensed light, and forming the light-shielding layer having the opening;
Applying a second material containing a negative photopolymer to the surface of the lens substrate on which the light-shielding layer is formed, and forming a second layer;
Exposing the second layer by irradiating the second layer with light incident from the side of the lens substrate on which the lens portion is formed and condensed by the lens portion; ,
And a step of developing the light diffusion portion so that a portion exposed by the condensed light remains in the second layer, and forming the light diffusion portion. Production method.   3. The method for manufacturing a transmissive screen member according to claim 1, wherein the lens portion is designed to focus on the light emission side of the light shielding layer.   The method for manufacturing a transmissive screen member according to any one of claims 1 to 3, wherein the light diffusing portion is formed so that a portion corresponding to the opening is a protruding portion protruding to the light emission side.   5. The transmissive screen member according to claim 4, wherein, when the transmissive screen member is viewed in plan, a ratio of an area occupied by the projecting portion in an effective region in which the lens portion is formed is 5 to 99%. Production method.   6. The method of manufacturing a transmissive screen member according to claim 1, wherein the plurality of light diffusion portions corresponding to the respective openings of the light shielding layer are formed so as to be independent of each other.   The ratio of the area which the said light-diffusion part occupies in the effective area | region in which the said lens part is formed when planarly viewing the transmission type screen member is 5 to 99%. A method for manufacturing a transmissive screen member.   The method for manufacturing a transmissive screen member according to any one of claims 1 to 7, wherein a length of the light diffusion portion in a direction perpendicular to a main surface of the transmissive screen member is 2 to 450 µm.   9. The transmissive screen member according to claim 1, wherein a focal point of the lens portion is a substantially central portion of the light diffusing portion in a direction perpendicular to a main surface of the transmissive screen member. Method.   The method for manufacturing a transmissive screen member according to any one of claims 1 to 9, wherein the lens substrate is manufactured using a substrate with a recess having a recess having a shape corresponding to the lens unit.   The ratio of the area occupied by the lens portion in an effective region where the lens portion is formed when the lens substrate is viewed in plan from the light incident surface side is 90% or more. A method for producing a transmissive screen member according to claim 1.   The method of manufacturing a transmissive screen member according to claim 1, wherein the lens portion is a microlens.   The method of manufacturing a transmissive screen member according to claim 12, wherein the plurality of microlenses have substantially the same radius of curvature.   The method for manufacturing a transmissive screen member according to claim 12 or 13, wherein the microlens has a diameter of 10 to 500 µm.   The method for manufacturing a transmissive screen member according to claim 1, wherein the opening has a diameter of 9 to 500 μm.   A transmissive screen member produced by the method according to claim 1.   A transmissive screen comprising the transmissive screen member according to claim 16. A Fresnel lens part having a Fresnel lens formed on the light exit side;
A transmissive screen comprising the transmissive screen member according to claim 16, which is disposed on a light emission side of the Fresnel lens portion.   A rear projector comprising the transmissive screen member according to claim 16.   A rear projector comprising the transmissive screen according to claim 17 or 18. The rear projector according to claim 19 or 20, comprising a projection optical unit and a light guide mirror.

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