JP2011232524A - Light diffusion member, transmission type screen, interactive board, and interactive board system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light diffusion member which can be manufactured inexpensively, has sufficient rigidity and shows different light diffusion characteristics according to a direction, a light transmission type screen, an interactive board, and an interactive board system.SOLUTION: A mesh layer 15 has a light diffusion effect for diffusing light made incident from one surface and emitting the light from the other surface, is like a sheet, and includes a net-like member 151 including at least a first thread-like member group 151a comprising a plurality of thread-like members made of resin, arranged at a predetermined interval in a first direction parallel with a sheet surface and a second thread-like member group 151b comprising a plurality of thread-like members made of resin, arranged at a predetermined interval in a second direction which is parallel with the sheet surface and different from the first direction. The second thread-like member group 151b is more densely arranged than the first thread-like member group 151a. The transmission type screen 10 having such a mesh layer 15, the interactive board 50 and the interactive board system are provided.

Description

  The present invention relates to a light diffusing member, a transmissive screen, an interactive board, and an interactive board system.

  The transmissive screen is used for a rear projection television or the like, and in recent years, is also used for an interactive board or the like (for example, Patent Document 1 and Patent Document 2). In such a transmissive screen, image light is projected at a large incident angle from below the transmissive screen, and at least a part of the incident light is totally reflected on the incident side in order to reduce the depth of a rear projection television or the like. Some have a possible total reflection surface and a prism layer (so-called total reflection Fresnel lens layer) in which a plurality of prisms that direct incident video light in the front direction of the screen are arranged.

Japanese Patent Laid-Open No. 2004-070188 JP 2008-046177 A

In such a transmissive screen, the uniformity of luminance within the screen is constantly required.
However, the above-described prism layer has a light beam control action in the vertical direction of the screen, particularly when the prisms are arranged in the vertical direction along the screen surface. Has no effect. Therefore, when image light is magnified and projected onto a transmission screen having such a prism layer, the luminance at the left and right ends of the screen is insufficient if the light diffusion function of the transmission screen is insufficient. There is a problem that the brightness of the screen is reduced, the uniformity of the luminance in the screen is lowered, and the image is deteriorated.
In order to improve this, there is a method (for example, Patent Document 1) including a lens sheet having a lens shape or a prism shape capable of diffusing light mainly in the left-right direction of the screen (for example, Patent Document 1). And the like are difficult to form, and the manufacturing cost is high.
Patent Documents 1 and 2 do not recognize such a problem of luminance non-uniformity in the horizontal direction of the screen, and relate to a light diffusing member that is easy to manufacture and has low manufacturing costs for improving the light control effect in the horizontal direction of the screen. No specific disclosure has been made.

  There is also a method of using a light diffusing sheet in which a needle-like or rod-like diffusing material oriented in one direction is coated or kneaded on a sheet-like member and the diffusibility is made anisotropic. However, in such a light diffusing sheet, there are many techniques for orienting the diffusing material in the forming direction (extrusion direction) of the sheet-like member. Therefore, when manufacturing a light diffusing sheet corresponding to a large screen, the molding direction of the sheet-like member is often the long side direction of the screen (left-right direction of the screen) due to equipment problems of the manufacturing apparatus. As a result, the obtained light diffusing sheet has a problem that a diffusing material is oriented in the long side direction (left and right direction of the screen), and a sheet having a large diffusing action in the left and right direction of the screen cannot be obtained.

Furthermore, in particular, when a transmissive screen is used for an interactive board, a user writes on the observation surface of the transmissive screen with a touch pen or the like, so that it is required to have sufficient rigidity against the force applied during such writing.
Therefore, there is a demand for a light diffusing member that can be used for a transmission screen or the like, is inexpensive, has sufficient rigidity, and has an anisotropic diffusing action.

  An object of the present invention is to provide a light diffusing member, a transmissive screen, an interactive board, and an interactive board system that can be manufactured at low cost, have sufficient rigidity, and exhibit different light diffusion characteristics depending on directions.

The present invention solves the above problems by the following means. In addition, in order to make an understanding easy, although the code | symbol corresponding to embodiment of this invention is attached | subjected and demonstrated, it is not limited to this.
The invention of claim 1 is a light diffusing member (15) having a light diffusing action of diffusing light incident from one surface and exiting from the other surface, and is in the form of a sheet, at least on the sheet surface. A first thread-like member group (151a) composed of a plurality of resinous thread-like members arranged at predetermined intervals in a parallel first direction, and is different from the first direction parallel to the sheet surface. And a second thread-like member group (151) having a second thread-like member group (151b) composed of a plurality of resinous thread-like members arranged at predetermined intervals in the second direction. 151b) is a light diffusing member (15) characterized in that it is arranged denser than the first thread-like member group (151a).
A second aspect of the present invention is the light diffusing member according to the first aspect, wherein the mesh portion (151) is transparent or translucent.
According to a third aspect of the present invention, in the light diffusing member according to the first or second aspect, the light diffusing member is formed of a resin having a refractive index different from that of the resin forming the mesh portion (151). The light diffusing member (15) includes a base material layer (152) as a material, and the mesh portion is bonded to the base material layer or embedded in the base material layer.

The invention according to claim 4 is the light diffusing member according to any one of claims 1 to 3, wherein the first direction and the second direction are orthogonal to each other. It is a diffusion member (15).
The invention according to claim 5 is the light diffusing member according to any one of claims 1 to 4, wherein the mesh portion (151) has a thread diameter of 5 to 300 μm and an aperture ratio of the thread member. 20 to 80%, the number of meshes is 2 to 300 mesh / inch, and the number of meshes in the second direction is larger than the number of meshes in the first direction (15) It is.
The invention of claim 6 is the light diffusing member according to any one of claims 1 to 5, wherein the mesh portion (151) is formed of crystalline plastic. It is a light-diffusion member (15).
According to a seventh aspect of the present invention, in the light diffusing member according to any one of the first to sixth aspects, the mesh opening portion (153) of the mesh portion (151) forms the mesh portion. The light diffusing member (15) is filled with a resin having a refractive index different from that of the resin.

The invention according to claim 8 is the light diffusing member (15) according to any one of claims 1 to 7, and an incident surface (A1) provided on the incident side from the light diffusing member and receiving light. And a prism layer (11) formed by arranging a plurality of unit prisms (111) having a total reflection surface (A2) that totally reflects at least a part of the light incident from the incident surface in a predetermined direction; Is a transmissive screen (10).
According to a ninth aspect of the present invention, in the transmissive screen according to the eighth aspect, the first direction is a screen vertical direction when the transmissive screen is used, and the second direction is the transmissive screen. The transmissive screen (10) is characterized in that it is in the horizontal direction of the screen in the usage state.
The invention of claim 10 is the transmission type screen according to claim 8 or claim 9, further comprising a light diffusion layer (12) containing a diffusing material on the exit side from the prism layer (11), and the mesh portion. (151) is the transmission screen (10) characterized in that it is located between the prism layer and the light diffusion layer in the thickness direction of the transmission screen.
The invention of claim 11 is an interactive board comprising the transmission screen (10) according to any one of claims 8 to 10, and a support base (51) for supporting the transmission screen. 50).
According to a twelfth aspect of the present invention, there is provided the interactive board according to the eleventh aspect, a light source unit (60) for projecting video light to the back of the transmissive screen, and video data to be displayed on the transmissive screen as a light source. An interactive board system including a control unit (70) for outputting to the unit.

According to the present invention, the following effects can be obtained.
(1) The light diffusing member according to the present invention has a sheet shape, and at least a first thread shape composed of a plurality of resinous thread-like members arranged at a predetermined interval in a first direction parallel to the sheet surface. A mesh having a member group and a second thread-like member group composed of a plurality of resinous thread-like members arranged at a predetermined interval in a second direction different from the first direction parallel to the sheet surface Therefore, different diffusion characteristics can be exhibited in the first direction and the second direction, and the design is easy. Moreover, the rigidity of light-diffusion member itself can be improved by providing a mesh part. In the light diffusing member according to the present invention, the second thread-like member group is arranged more densely than the first thread-like member group, so that the light diffusing action in the second direction is the first direction. Compared to

(2) Since the mesh portion is transparent or translucent, the amount of light absorption can be suppressed.

(3) The light diffusing member is formed of a resin having a refractive index different from that of the resin forming the net-like portion, and includes a base material layer serving as a base material of the light diffusing member, and the net-like portion is bonded to the base material layer or Since it is embedded in the base material layer, the light diffusing member can be handled as a light diffusing sheet or the like, and the handling is easy.

(4) Since the first direction and the second direction are orthogonal, the diffusion characteristics in the two orthogonal directions can be made different.

(5) The mesh portion has a thread diameter of 5 to 300 μm, an aperture ratio of 20 to 80%, a mesh number of 2 to 300 mesh / inch, and the mesh number in the second direction is the first direction. Larger than the number of meshes in. Therefore, the diffusion action in the second direction can be exerted strongly without significantly reducing the luminance. Accordingly, an anisotropic diffusion effect can be easily realized.

(6) Since the mesh portion is formed of crystalline plastic, diffusion performance can be enhanced, and further, high rigidity and high heat resistance can be achieved.

(7) Since the opening portion of the mesh of the mesh portion is filled with a resin having a refractive index different from that of the resin forming the mesh portion, no gas such as air exists in the opening portion. Therefore, it is possible to reduce as much as possible that the amount of incident light is reflected in various directions due to the difference in refractive index from a gas such as air and the amount of emitted light is reduced. Moreover, manufacture is also easy.

(8) A light diffusing member according to the present invention, an incident surface provided on the incident side from the light diffusing member, and a total reflection surface that totally reflects at least a part of light incident from the incident surface in a predetermined direction. And a prism layer formed by arranging a plurality of unit prisms having a plurality of unit prisms. Therefore, the light beam control action in the vertical direction of the screen by the prism layer and the diffusion characteristic having anisotropy by the light diffusion member are obtained. By combining, it is possible to improve the uniformity of the brightness of the screen.

(9) Since the first direction is the vertical direction of the screen when the transmissive screen is used, and the second direction is the horizontal direction of the screen when the transmissive screen is used, the light diffusing member is the horizontal direction of the screen. The diffusion effect can be exerted, and the uniformity of the brightness of the screen can be improved.

(10) A light diffusing layer containing a diffusing material is provided on the exit side from the prism layer, and the mesh portion is located between the prism layer and the light diffusing layer in the thickness direction of the transmissive screen, so that it is more efficient. Brightness uniformity can be improved.

(11) Since the interactive board includes the transmission screen according to the present invention and the support base that supports the transmission screen, the screen has high in-plane luminance uniformity and can display a good image.
Since the interactive board system includes such an interactive board, a light source unit that projects video light to the back of the transmissive screen, and a control unit that outputs video data to be displayed on the transmissive screen to the light source unit, The in-plane uniformity of the screen brightness is high, a good image can be displayed, and it is convenient and useful for meetings and classes.

It is a figure explaining the interactive board and interactive board system of an embodiment. It is a figure which shows the screen of embodiment. It is a figure explaining the layer structure of the screen of embodiment. It is a figure which shows the shape of a prism part. It is a figure explaining the shape of a mesh layer. It is a figure which compares the light-diffusion characteristic of the screen of embodiment, and the screen of a comparative example. It is a figure explaining the deformation | transformation form of an interactive board. It is a figure explaining the deformation | transformation form of an interactive board. It is a figure which shows the deformation | transformation form of a unit prism.

Embodiments of the present invention will be described below with reference to the drawings.
In addition, each figure shown below including FIG. 1 is the figure shown typically, and the magnitude | size and shape of each part are exaggerated suitably for easy understanding.
In addition, the numerical values such as the dimensions of the respective members and the material names described in the present specification are examples of the embodiment, and are not limited thereto, and may be appropriately selected and used.

(Embodiment)
FIG. 1 is a diagram illustrating an interactive board and an interactive board system according to the present embodiment.
The interactive board system includes an interactive board 50, a projector 60, a control unit 70 such as a personal computer, an input unit 80 capable of drawing characters and figures on the observation surface of the interactive board 50, and information detection (not shown). Department.
The interactive board 50 includes a support base 51 and a transmissive screen (hereinafter, simply referred to as a screen or a board for ease of understanding) 10 for the interactive board. The interactive board 50 is configured to project image light from the back side.
The support base 51 is a member that holds the four sides of the screen 10 to maintain its flatness and supports the screen 10 at a predetermined height. The support base 51 may be capable of changing the height of the screen 10 or may not be changed. Moreover, it is good also as a form which can provide a wheel etc. in the earthing | grounding part with the floor surface of the support stand 51, and can move.

The screen 10 is a board on which an image is displayed and the user S draws information such as characters on the observation surface using the input unit 80 such as a touch pen.
The screen 10 is a transmissive screen, and can transmit the image light projected on the back surface of the screen 10 from the projector 60 positioned on the back surface of the interactive board 50 and display it on the observation surface. Details regarding the shape of the screen 10 will be described later.
The projector 60 is a light source unit that projects video light from the back side of the screen 10 (interactive board 50). The projector 60 is separate from the interactive board 50, and a general-purpose projector or the like may be used. For example, a light source device such as a DLP or LCD method may be used, or a digital camera having a function as a projector capable of projecting an image may be used, which can be appropriately selected according to the purpose of use and the use environment. The projector 60 according to the present embodiment is a projector, and projects image light from a lower side than a center portion of the screen 10 toward obliquely upward.

The input unit 80 is a member such as a touch pen for touching the observation surface of the screen 10.
The information detection unit (not shown) has a function of detecting information such as characters and figures drawn by the input unit 80 and transmitting the information to the control unit. This information detection unit uses, for example, a touch panel provided on the screen 10, a position sensor such as an infrared sensor that is disposed on the upper and lower portions of the interactive board and detects the position where the input unit 80 contacts. Can do. The information detection unit of the present embodiment uses a position sensor, and detects the coordinate position of the input unit 80 on the observation surface of the screen 10, so that the user S draws a figure, a character, or the like drawn on the observation surface. Information is detected and the detected signal is output to a control unit such as a personal computer.
The information detection unit can communicate with a control unit such as a personal computer by wire or wirelessly, and the information detection unit of the present embodiment is connected to the personal computer 70 via a USB cable or the like so as to be communicable.

The personal computer 70 outputs information to be displayed on the screen 10 to the projector 60, takes in information from the information detection unit and converts it into data, and outputs an image including the taken in information, and the screen 10. A storage unit (not shown) which is a storage device for storing image information to be displayed on the computer, programs of various applications, and the like. The control unit is configured by, for example, a CPU (Central Processing Unit) and the like, and is a part that controls the interactive board system in an integrated manner. This control unit determines the coordinate position of the observation surface 12b in contact with the input unit 80 based on the detection signal of the information detection unit, and determines characters, figures, and the like drawn by the input unit 80.
The personal computer 70 of the present embodiment is wired using a USB cable or the like, and is connected to the information detection unit and the projector 60 and can communicate with each other. However, the personal computer 70 is not limited to this, and can communicate with at least one wirelessly. It is good also as a form.
In the present embodiment, an example using the personal computer 70 has been described. However, for example, a mobile terminal (such as a mobile phone) may be used as long as it has a function capable of comprehensively controlling the interactive board system. These may be selected and used as appropriate according to the usage environment.

In the interactive board system of the present embodiment, the personal computer 70 outputs video information to the projector 60, the projector 60 projects video light to the back of the interactive board 50, and the interactive board 50 has an observation surface. An image is displayed on the surface of the screen 10 on the observer side. The information detection unit detects the coordinate position of the observation surface touched by the user S using the input unit 80, and the personal computer 70 can determine the coordinate position. For example, the user S can adjust the position information on the interactive board 50 or the personal computer 70 so that the position information on the screen of the personal computer 70 matches the position information (coordinate information) on the observation surface. To adjust in advance. Thus, for example, if the display screen of the personal computer 70 is displayed on the interactive board 50, the user S can operate the personal computer 70 by operating the input unit 80 so as to operate with the mouse. In addition, it is possible to display a figure, a character, or the like drawn on the observation surface of the screen 10 by the user S using the input unit 80 together with the projection image.
Furthermore, the screen 10 draws information such as characters and figures by handwriting on its surface (observation surface) using a predetermined writing instrument such as a marker, such as a whiteboard, or erases the drawn characters. It is good also as a form which can be performed. The actually entered information may be detected by the information detection unit and output to the personal computer 70.

FIG. 2 is a diagram showing the screen of the present embodiment.
FIG. 3 is a diagram for explaining the layer structure of the screen according to the present embodiment. In FIG. 3, a part of a cross section when the screen 10 is cut in a direction parallel to the vertical direction (up and down direction of the screen) in use and parallel to the thickness direction of the screen 10 (direction perpendicular to the screen surface). Is shown enlarged.
In the following specification, unless otherwise specified, the vertical direction and the horizontal direction are the vertical direction (up and down direction of the screen) and the horizontal direction (left and right direction of the screen) in the usage state of the transmissive screen. .
Further, the screen surface indicates a surface in the plane direction of the screen when viewed as the screen 10 as a whole, and is used as the same definition in the present specification and claims. This screen surface is a surface on the exit side of the screen 10, that is, a surface parallel to the observation surface.
As shown in FIG. 3, the screen 10 includes a prism layer 11, a mesh layer 15, a light diffusion layer 12, a substrate layer 13, and a hard coat layer 14 in order from the light incident side (back side) in the use state. Yes. As shown in FIG. 3, the substrate layer 13 and the hard coat layer 14 are integrally bonded through a bonding layer 16. This screen 10 forms an image of the image light projected from the projector 60 and displays it.

The prism layer 11 is provided on the most back side (incident side) of the screen 10 and includes a prism portion 112 and a base material portion 113.
In the prism portion 112, a plurality of unit prisms 111 are arranged in one direction (vertical direction) along the screen surface on the incident-side surface. The prism layer 11 condenses the image light projected from the projector 60 and has a light beam control function of emitting the image light to the observation surface side (exit side) as substantially parallel light in the front direction of the screen 10.
FIG. 4 is a diagram illustrating the shape of the prism portion. In FIG. 4, a part of the prism portion 112 is enlarged and shown in the same cross section as that shown in FIG. 3.
The unit prism 111 has a convex shape toward the incident side, and has a prism shape including an incident surface A1 on which light is incident and a total reflection surface A2 that totally reflects at least part of the light incident from the incident surface A1. . The unit prism 111 of this embodiment has an apex angle α = 38 ° formed by the incident surface A1 and the total reflection surface A2, and an arrangement pitch P = 50 μm.
At least part of the light (light L1) incident on the unit prism 111 from the incident surface A1 among the image light irradiated obliquely from the projector 60 positioned below is refracted by the incident surface A1 and is on the total reflection surface A2 side. , And is totally reflected by the total reflection surface A2, becomes substantially parallel light in the normal direction of the screen surface, and proceeds to the viewer side.
The prism portion 112 is formed of an ionizing radiation curable resin such as an ultraviolet curable resin such as urethane acrylate or epoxy acrylate, or an electron beam curable resin. The prism portion 112 of the present embodiment is formed of a urethane acrylate ultraviolet curable resin (manufactured by DNP Fine Chemical Co.) having a refractive index of 1.55.

The base material portion 113 is a resin-made sheet-like member having light transmittance, and is a layer serving as a base for forming the prism portion 112. The base material portion 113 is located on the exit side of the prism portion 112, and the prism portion 112 is integrally formed on the incident side surface. The base material portion 113 of the present embodiment uses a sheet-like member made of PET resin having a refractive index of 1.55 and a thickness of 100 μm. In addition, as the base material part 113, you may use the sheet-like member made from other thermoplastic resins, such as PC (polycarbonate) resin and an acrylic resin.
For example, the prism layer 11 is filled with a mold having an inverse shape of the unit prisms 111 arranged by applying an ultraviolet curable resin or the like, and a base material portion 113 is pressure-laminated on the mold and irradiated with ultraviolet rays. It can be formed by, for example, peeling from the mold after curing the resin.

  The mesh layer 15 is a light diffusion member having anisotropy in its diffusion characteristics. The mesh layer 15 is provided between the prism layer 11 and the light diffusing layer 12, and a resin mesh portion 151 exists in a light-transmitting resin (resin layer 152) (described later). FIG. 5). The mesh layer 15 of the present embodiment also has a function of joining the prism layer 11 and the light diffusion layer 12. Details of the shape and the like of the mesh layer 15 will be described later.

The light diffusion layer 12 is a layer having a function of diffusing light, and is disposed on the emission side (observation surface side) from the prism layer 11. The light diffusing layer 12 can be a sheet-like member blended in a resin having light permeability so that a substantially spherical diffusing material is dispersed substantially uniformly. The light diffusion layer 12 of this embodiment has a thickness of 1 mm and a refractive index of 1.55 as a base material of MS (methyl methacrylate / styrene) resin, and a refractive index of 1.41 as a diffusion material. A predetermined amount of spherical silicon beads and acrylic beads having a refractive index of 1.53 are combined and kneaded substantially uniformly.
The thickness of the light diffusion layer 12 can be selected as appropriate. Also, as a base material containing a diffusing material, MBS (methyl methacrylate / butadiene / styrene) resin, TAC (triacetate cellulose) resin, PET resin, PC Resins and the like can be selected as appropriate. Further, as the diffusion material, substantially transparent particles of an inorganic or organic compound such as glass beads or plastic beads can be appropriately selected. The particle size of the diffusing material is preferably 1 μm or more so that light diffusion does not depend on the wavelength.

The substrate layer 13 is a layer that becomes the substrate of the screen 10. The substrate layer 13 has the largest thickness compared to the other layers constituting the screen 10, and thus has rigidity to maintain the flatness of the screen 10.
The substrate layer 13 of the present embodiment is an 8 mm sheet-like member made of MS resin having optical transparency, and its refractive index is 1.55. In addition, as the board | substrate layer 13, you may use other resin-made sheet-like members, such as PC resin, a glass plate, etc., and the thickness is 7 in the case of a resin-made sheet-like member. It may be appropriately selected within a range of ˜9 mm and within a range of 4 to 6 mm in the case of a glass plate.
The light diffusion layer 12 and the substrate layer 13 of this embodiment are integrally formed by two-layer extrusion molding.

The hard coat layer 14 is a layer having scratch resistance that protects the observation surface of the screen 10 from scratches and smoothness that is easy to write. The observation surface (front surface) of the screen 10 is a surface on which the user S writes characters and the like with the input unit 80 such as a touch pen, so that scratch resistance is required, and observation is performed so that writing can be performed smoothly. Surface smoothness is also required.
The hard coat layer 14 of the present embodiment has a sheet-shaped member made of PET resin having a thickness of 188 μm as a base material, and various ionizing radiation curable resins, thermoplastic resins and ionizing radiation curable resins are provided on the surface thereof. It is formed by applying a mixture with a solvent or a thermosetting resin.
The bonding layer 16 bonds the substrate layer 13 and the hard coat layer 14. For the bonding layer 16, an ultraviolet curable acrylic resin, a pressure-sensitive adhesive acrylic resin whose adhesiveness is manifested by pressure, or the like can be used. Further, the bonding layer 16 can be appropriately selected within a range of 10 to 100 μm in thickness.

FIG. 5 is a diagram for explaining the shape of the mesh layer 15. FIG. 5A is a diagram of the mesh layer viewed from the normal direction of the screen surface, and FIGS. 5B and 5C are diagrams illustrating the characteristics of the diffusion action.
The mesh layer 15 is a layer including a mesh portion 151 and a resin layer 152, and has a form in which a sheet-like mesh portion 151 is embedded in the resin layer 152.
The net-like portion 151 is a transparent or translucent resin-like net-like member, and the first thread-like member group 151a extending in the horizontal direction and arranged in the vertical direction, and extending in the vertical direction and arranged in the horizontal direction The second thread-like member group 151b is formed. The mesh portion 151 is in the form of a sheet, and the first thread-like member group 151a and the second thread-like member group 151b are parallel to the sheet surface (surface parallel to the screen surface) of the mesh-like portion 151 and orthogonal to each other. Are arranged so that they touch each other at the intersection.

  The first thread-like member group 151a and the second thread-like member group 151b of the present embodiment are formed using nylon-like nanofilament (single fiber) thread-like members having a thread diameter of about 50 μm. The thread diameter of the thread-like member is preferably in the range of 5 to 300 μm because it is not confirmed visually. This is because when the thread-like member is visually confirmed, the visibility of the image may be lowered. In addition, although the 1st thread-like member group 151a and the 2nd thread-like member group 151b showed the example using the resin-like thread-like members with the substantially same diameter, the thing from which resin and a thread | yarn diameter differ may be used. Good.

As the resin of the first thread-like member group 151a and the second thread-like member group 151b, other crystalline resins such as PET resin may be used, polystyrene (styrol), ABS (acrylonitrile butadiene styrene). It is also possible to use an amorphous resin such as a resin, an AS (acrylonitrile / styrene) resin, an acrylic resin, or a PC resin. In the case where a crystalline resin is used, in addition to the effect of improving the light diffusibility by the mesh portion 151, it has the effect of increasing the rigidity of the mesh member and the effect of increasing the heat resistance.
In addition, the thread-like members forming the first thread-like member group 151a and the second thread-like member group 151b are not limited to nanofilaments, and multifilaments made of a plurality of fibers may be used.
Furthermore, although the net-like part 151 of this embodiment showed the example which is a tricarnet as shown to Fig.5 (a), it is good also as a plain weave, a calami weave, etc. FIG.

As shown in FIG. 5A, the arrangement pitch P1 in the vertical direction of the first thread-like member group 151a and the arrangement pitch P2 in the horizontal direction of the second thread-like member group 151b are P1> P2, The second thread-like member group 151b (arranged in the horizontal direction) is more densely arranged than the first thread-like member group 151a (arranged in the vertical direction). Therefore, the opening portion 153 serving as a mesh opening has a rectangular shape that is long in the vertical direction.
The mesh portion 151 preferably has a mesh number of 3 to 800 mesh / inch. This is because if the number of meshes is less than 3 mesh / inch, the diffusibility due to the mesh portion 151 cannot be expressed, and if it is more than 800 mesh / inch, the aperture ratio of the mesh portion 151 is lowered and brightness cannot be obtained. Further, the mesh portion 151 has different numbers of meshes in the horizontal direction and the vertical direction, and in the horizontal direction (the second thread-like member group 151b) compared to the vertical direction (the arrangement direction of the first thread-like member group 151a). The arrangement direction) has a larger number of meshes. The mesh portion 151 of this embodiment has a mesh count in the horizontal direction of 30 mesh / inch and a mesh count in the vertical direction of 20 mesh / inch.

In addition, the mesh portion 151 preferably has an opening ratio (also referred to as OPA or opening ratio) of 20 to 80%. This is because if the aperture ratio is less than 20%, the front luminance decreases, and if the aperture ratio is greater than 80%, the diffusibility by the mesh portion 151 cannot be obtained.
In order to realize the light diffusibility by the mesh portion 151, the thread members used for the first thread member group 151a and the second thread member group 151b of the mesh portion 151 are within the above-described preferable yarn diameter range. It is preferable that the wire diameter is as thin as possible, and it is preferable to arrange as many as possible within the above-mentioned preferable ranges of the aperture ratio and the number of meshes.

The resin layer 152 is a layer formed of a resin having a refractive index different from that of the mesh portion 151. The resin layer 152 encloses the mesh portion 151 and fills the opening portion 153 of the mesh with resin. In the present embodiment, an acrylic resin having light transmittance is used, and the prism layer 11 is joined to the incident side surface of the light diffusion layer 12. The resin layer 152 preferably has a refractive index difference | Δn | satisfying | Δn | = 0.01 to 0.25 with respect to the resin forming the mesh portion 151. This is because if the refractive index difference | Δn | is less than 0.01, sufficient diffusibility by the mesh portion 151 cannot be obtained, and if the refractive index difference | Δn | exceeds 0.25, the transmittance decreases.
The mesh layer 15 is formed by, for example, arranging a mesh portion 151 on the incident side surface of the light diffusion layer 12, applying a resin for forming the resin layer 152 from above, and laminating the prism layer 11 thereon. It is formed. The resin layer 152 is cured, so that the prism layer 11 is bonded to the incident side surface of the light diffusion layer 12. In addition, the formation method of the mesh layer 15 can be suitably selected according to resin etc. to be used.

In the mesh layer 15, since the number of arrangement per unit area of the first thread-like member group 151a and the second thread-like member group 151b is different, the diffusing action on the light incident on the mesh layer 15 is the first thread-like member group. The strength differs between the arrangement direction of 151a and the arrangement direction of the second thread-like member group 151b. That is, the diffusing action of the mesh layer 15 has anisotropy.
Assuming that a light beam is incident on a point A of the mesh layer 15 from the front direction, the light beam is diffused by the mesh portion 151, and when viewed from the front direction of the mesh layer 15, an approximate line as indicated by a dotted line in FIG. Although it spreads in an elliptical area, the spread in the vertical direction is small as shown by a dotted line in FIG. That is, the diffusion characteristic of the mesh layer 15 has an anisotropy that the diffusion action in the horizontal direction is much larger than the diffusion action in the vertical direction.
Therefore, by combining a layer having a light beam control action in the vertical direction of the screen, such as the prism layer 11, with the mesh layer 15 described above, the uniformity of luminance within the screen 10 can be improved.

Here, the screen 10 of the present embodiment and the screen 10B of the comparative example (see FIG. 6 to be described later) are actually incorporated into the support base 51, and image light is projected from the back as an interactive board 50. The uniformity within the screen was evaluated visually.
In the screen 10B of the comparative example, the layer corresponding to the mesh layer 15 of the screen 10 of the present embodiment does not include the mesh portion 151, and has only a function of joining the prism layer 11 and the light diffusion layer 12. Except for the difference, the screen is the same as the screen 10 of the present embodiment.
When the luminance in the screen was examined by actually projecting the image light L from the projector 60, the luminance in the vertical direction of the screen was substantially uniform in the screen 10B of the comparative example. However, in the screen 10B of the comparative example, the luminance is high in the central portion of the screen in the left-right direction of the screen, but the luminance decreases as it goes to the left and right ends, and the luminance is observed darker. The direction was uneven and the image quality was degraded.
On the other hand, the screen 10 of this embodiment has a substantially uniform luminance distribution both in the vertical direction of the screen and in the horizontal direction of the screen, and can greatly suppress a decrease in luminance at the left and right edges of the screen and in the vicinity thereof. The displayed image quality was good.

FIG. 6 is a diagram comparing the light diffusion characteristics of the screen of this embodiment and the screen of the comparative example. 6A shows the horizontal direction of the light emitted from the prism layer 11, FIG. 6B shows the diffusion characteristics of the screen 10 of the present embodiment, and FIG. 6C shows the comparative example. The diffusion characteristics of the screen 10B are shown.
FIG. 6 shows a cross section parallel to the screen horizontal direction of each screen and orthogonal to the screen surface. In FIGS. 6B and 6C, the prism layer 11 and the hard coat layer 14 of each screen are omitted for easy understanding. The horizontal diffusion characteristics (light spread) are indicated by dotted lines, and the light toward the observer O in the front direction of the screen is indicated by arrows.

In general, the projector 60 is disposed at a position that is substantially in the center in the left-right direction of the screen and below the screen, and the image light L that is enlarged and projected from the projector 60 has a large incident on the back surface of each screen. Incident at an angle. The image light L is directed substantially in the front direction of the screen (direction perpendicular to the screen surface) in the vertical direction (the screen vertical direction) by the optical action of the prism layer 11. However, the prism layer 11 has a light beam control function in the vertical direction (up and down direction of the screen), but hardly has a light beam control function in the horizontal direction (left and right direction of the screen).
For this reason, the light La incident on the substantially central portion of the screen has almost no component in the left-right direction of the screen. Therefore, almost all components are subjected to the light beam control action of the prism layer 11, and as shown in FIG. Exit in the direction. However, the light Lb incident on the left and right ends of the screen of the screen is incident on the screen at a large angle not only in the vertical direction but also in the horizontal direction. Therefore, such light has a large component in the horizontal direction of the screen. Since these components are not subjected to the light beam control action of the prism layer 11, as shown in FIG. 6 (a), they become light Lb that passes through in an oblique direction toward the outside of the screen. Such a phenomenon increases as the incident angle increases, for example, the screen becomes larger.

Therefore, in the comparative screen 10B that includes only the light diffusing layer 12 as the light diffusing layer and does not include the mesh layer 15 (net-like portion 151), as shown in FIG. The brightness at is high. However, since the light diffusion layer 12 has a substantially omnidirectional diffusion action at the left and right ends of the screen 10B of the comparative example, the light beam control action in the horizontal direction is small, as shown by the broken line in FIG. As described above, the light is diffused so as to spread to the outside of the screen 10B, and there is little light directed toward the observer O side. Therefore, in the screen 10B of the comparative example, a phenomenon occurs in which the central portion of the screen screen is bright and the luminance decreases toward the left and right ends.
On the other hand, the screen 10 of the present embodiment includes the mesh layer 15 having a large horizontal diffusion function and a small vertical diffusion function. The light incident in the vicinity is strongly diffused in the horizontal direction, the light traveling toward the outside of the screen 10 is reduced, and the light traveling toward the observer side is greatly increased. Therefore, as shown in FIG. 6B, even if the light is diffused again by the light diffusion layer 12 thereafter, the amount of light directed from the left and right end portions of the screen 10 toward the viewer side is larger than that in the comparative example, The uniformity of luminance in the direction is improved. Moreover, although the mesh layer 15 has a diffusing action (light beam controlling action) in the vertical direction, the diffusing action is small, so that the light directed toward the substantially front direction of the screen is appropriately diffused by the prism layer 11. The brightness in the front direction is not significantly reduced.

Therefore, according to the present embodiment, it is possible to obtain anisotropic diffusion characteristics without using a lens-like sheet such as a lenticular lens sheet having horizontal diffusivity, thereby reducing production costs. It is also easy to manufacture.
Further, according to the present embodiment, the ratio of the number of arrangement per unit area of the first thread-like member group 151a and the second thread-like member group 151b of the mesh portion 151, the aperture ratio, the thickness of the thread-like member, the resin, etc. By changing it, the anisotropy of the diffusion action of the mesh layer 15 can be easily controlled. Therefore, optimal anisotropy can be easily realized according to the use environment, desired diffusion performance, and the like.
Furthermore, according to the present embodiment, the size of the screen 10 is increased without being restricted by the manufacturing apparatus in the orientation direction, such as an anisotropic diffusion sheet using a conventional needle-like or rod-like diffusion material. Is also ready.

Furthermore, according to the present embodiment, since the net portion 151 is formed of a crystalline resin, the resin crystal is scattered in the non-crystalline region like an island in the thread member. Since the refractive index is slightly different between the crystalline portion and the non-crystalline portion, the diffusion action of the mesh layer 15 can be enhanced, and the effect of backscattering (back scattering) can be obtained. Thereby, the surface uniformity of the brightness | luminance of the screen 10 can be improved, without reducing the transmittance | permeability significantly.
In addition, by providing the mesh layer 15, the mesh portion 151 exists in the screen 10, so that the rigidity of the screen 10 can be increased. When the screen 10 is used as the screen of the interactive board 50 as in the present embodiment, the user S writes on the observation surface of the screen 10 with the input unit 80, and thus the screen 10 is likely to be subjected to a force on the back side. However, since the rigidity is increased by the mesh layer 15, the flatness of the screen 10 is improved, and image distortion and the like can be effectively reduced.

(Deformation)
Without being limited to the embodiments described above, various modifications and changes are possible, and these are also within the scope of the present invention.
(1) In the present embodiment, the mesh layer 15 is provided between the prism layer 11 and the light diffusion layer 12 in the thickness direction of the screen 10. However, the present invention is not limited thereto, and the thickness direction of the screen 10 is not limited thereto. As long as it is between the hard-coat layer 14 and the prism part 112, it may be located anywhere.
In addition, the net-like portion 151 is not provided in the resin layer 152 but may be provided on the surface of the resin layer 152, for example.
Further, the mesh layer 15 has a configuration in which the mesh portion 151 is provided in the resin layer 152. However, the mesh layer 151 is not limited to this. For example, the mesh layer 15 may have a configuration in which the mesh portion 151 is provided in the light diffusion layer 12 or the substrate layer 13. Also good.

(2) In the present embodiment, the screen 10 includes the prism layer 11, the light diffusion layer 12, the substrate layer 13, the hard coat layer 14, the mesh layer 15, and the like. It is good also as a form provided only with the diffusion layer 12 and the board | substrate layer 13, and it is good also as a form in which the prism part 112 is formed in the surface at the back side of the light-diffusion layer 12, and the structure in particular is not limited. At this time, the mesh layer 15 may be located anywhere between the hard coat layer 14 and the prism portion 112 in the thickness direction of the screen 10.

(3) In the present embodiment, the light diffusing layer 12 has shown an example containing a substantially spherical diffusing material. However, the present invention is not limited to this. For example, the light diffusing layer 12 contains a diffusing material having a shape such as a substantially elliptical sphere or a substantially rod shape. Also good. However, at this time, since the diffusing material having a shape such as a substantially elliptical sphere or a substantially rod shape is oriented in the line direction at the time of manufacturing the light diffusing layer 12, it is necessary to match the manufacturing direction with the preferred orientation direction.

(4) In the present embodiment, an example in which the mesh portion 151 includes the first thread-like member group 151a and the second thread-like member group 151b has been described. However, the first thread-like member group 151a and the second thread-like member are illustrated. It is good also as a form further provided with the at least 1 or more filamentous group arranged in the direction different from the group 151b.
In addition, although the first thread-like member group 151a and the second thread-like member group 151b are both parallel to the sheet surface (screen surface) and orthogonal to each other, they are not orthogonal, but the desired diffusion You may change the angle | corner which intersects suitably according to a characteristic.
Furthermore, although the example in which the second thread-like member group 151b is arranged more densely than the first thread-like member group 151a is shown, the first thread-like member group 151a is changed according to the desired optical characteristics and the like. It is good also as a form arranged closely.

(5) In the present embodiment, the opening portion of the mesh of the mesh portion 151 is illustrated as being blocked by the resin of the resin layer 152. However, the present invention is not limited to this, and air may be present in the opening portion. Good.

(6) In the present embodiment, the screen 10 is used in the interactive board 50 and the interactive board system. However, the screen 10 is not limited thereto, and may be used in a rear projection display device such as a rear projection television. .

(7) In the present embodiment, the example in which the light diffusion layer 12 and the substrate layer 13 are integrally formed by two-layer extrusion molding has been shown. However, the present invention is not limited thereto, and for example, the light diffusion layer 12 and the substrate layer 13 It is good also as a form joined by a joining layer etc. as another layer.
In the present embodiment, the hard coat layer 14 is bonded to the substrate layer 13 via the bonding layer 16. However, the present invention is not limited to this, and the hard coat layer is directly applied to the emission side surface of the substrate layer 13. It is good also as a form which forms and does not provide a joining layer.

(8) In the present embodiment, the interactive board 50 is the one in which the screen 10 is supported by the support base 51, and the example in which the image light L is projected from the back side of the screen by the separate projector 60 is shown. For example, the interactive board 90-1 may be integrated with the screen 91 and the projector 61 incorporated in the housing 91, or the interactive boards 90-2 and 90-3 fixed to the wall surface. Also good.

7 and 8 are diagrams for explaining a modification of the interactive board.
In the interactive board 90-1 of the modified form shown in FIG. 7, the screen 10 is fitted into the casing 91, and the image light projected from the projector (light source unit) 61 arranged at the lower part of the casing 91 is received in the casing 91. It is configured to irradiate from the back surface of the screen 10 after being reflected by the mirror portions 92 and 93 disposed inside. The interactive board 90-1 includes an information detection unit such as a position sensor or a touch panel sensor, and can also be used as an interactive board system that can communicate with the personal computer 70 or the like by wire or wirelessly.
By adopting a form such as the interactive board 90-1, the back side of the screen 10 is covered with the casing 91 and becomes a dark room. Therefore, light and illumination light from a window located on the back side of the interactive board 90-1 It is possible to prevent external light such as from entering from the back surface of the screen 10, improve the contrast, and display a clearer image.

Further, the interactive boards 90-2 and 90-3 of the modified embodiment shown in FIG. 8 are fixed to the wall surface H by being connected to the frame-like support member 94 that holds the four sides of the screen 10 and the support member 94. Member 95. The interactive boards 90-2 and 90-3 are fixed to the wall surface H with a predetermined interval according to the projection distance of the projector by the support member 94 and the fixing member 95.
A fixing member 95 shown in FIG. 8 is a substantially rectangular cylindrical member having an opening on the lower side of the screen 10, and is connected to the support members 94 on the upper side and the left and right sides of the screen 10, and is fixed to the wall surface H. Has been. For example, the fixing member 95 may be fixed to the support member 94 on the upper side of the substantially rectangular screen 10 and fixed to the wall surface H. The shape of the fixing member 95 depends on the usage environment, the wall surface condition, and the like. You can design freely.
As described above, in the case of the interactive boards 90-2 and 90-3 that are fixed to the wall surface H, for example, as shown in FIG. 8A, the projector 62 including the mirror unit 621 is placed below the screen 10. The image light L may be reflected by the mirror unit 621 and projected onto the back surface of the screen 10, or the mirror unit 96 may be disposed on the wall surface H as shown in FIG. The image light L from the projector 60 disposed below may be reflected by the mirror unit 96 and projected onto the back side of the screen 10.
By adopting such a configuration, the three sides of the screen 10 are fixed to the wall surface. Therefore, the screen 10 is shaken by the force applied to the observation surface of the screen 10 when the user S writes on the surface of the screen 10. It is possible to reduce the problem of video and difficulty in viewing. Moreover, since it is fixed to the wall surface H, unnecessary light incident on the screen 10 from the back side can be reduced, and the contrast can be improved.

(9) In the present embodiment, the unit prism 111 is formed only from the incident surface A1 and the total reflection surface A2. However, for example, a hybrid type having a total reflection prism shape and a refractive Fresnel lens shape is shown. It may be a prism shape.
FIG. 9 is a diagram showing a modified form of the unit prism 111.
The unit prism 411 of the modified prism portion 412 has a total reflection prism shape 411a and a refractive Fresnel lens shape 411b.
The total reflection prism shape 411a includes an incident surface A1 and a total reflection surface A2, and is a part of the shape of the unit prism 111 shown in each embodiment. The refractive Fresnel lens shape 411b is located on the lower side in the vertical direction of the total reflection prism shape 411a, faces the incident surface A1, and enters the third surface A3 and the third surface A3 which are incident surfaces on which light is incident. And a fourth surface A4 having a convex shape, which is a part of the shape of a so-called refractive Fresnel lens.
Here, the light L2 incident on the third surface A3 is refracted at the interface (third surface A3), and becomes substantially parallel light in the normal direction of the screen surface and travels to the observation surface side. Therefore, by adopting such a hybrid prism shape, it is possible to increase the amount of image light that is substantially parallel light in the normal direction of the screen surface.

(10) In the present embodiment, the unit prisms 111 are arranged in one direction (vertical direction) along the screen surface. However, the present invention is not limited to this example. They may be arranged concentrically around the center.

(11) In the present embodiment, an example is shown in which only one interactive board 50 and one personal computer 70 are used. However, the present invention is not limited to this. For example, a plurality of personal computers 70 are connected to the Internet or the like. The interactive board 50 may be connected to each of the plurality of personal computers. With such a form, the drawn information can be shared even in a remote place, and a conference between remote places can be efficiently performed by using it together with a video conference system or the like.

(12) In the present embodiment, the interactive board system has shown an example in which the coordinate position on the observation surface of the screen in contact with the input unit 80 is detected and output to the personal computer 70. It is also possible to adopt a form in which information such as characters written by the user S is projected onto the screen by an input unit 80 on an input device (not shown) that is separate from the interactive board and connected to the personal computer 70 by wire or wirelessly. Good. Note that a tablet or the like can be used as such a separate input device.

(13) In the present embodiment, an example in which the hard coat layer 14 is located on the most exit side of the screen 10 has been shown. However, the present invention is not limited thereto, and for example, reflection of illumination light is suppressed on the incident side of the hard coat layer 14 A layer having an antireflection function, an antistatic layer function, an ultraviolet absorption function, an antiglare function, an antifouling function, a coloring or dimming function, and the like may be provided.
In the case of having an antireflection function, reflection of illumination light or the like can be prevented and contrast can be improved. In the case of having an antistatic function, static electricity can be removed and dust and the like can be prevented from adhering to the observation surface. In the case of having an ultraviolet absorption function, yellowing of the screen 10 due to ultraviolet rays contained in external light can be prevented. In the case of having an anti-glare function, it is possible to improve the visibility by reducing the reflection and reflection of illumination light. When it has an antifouling function, it is possible to prevent dirt from adhering to the surface of the screen 10. In the case of having a coloring or dimming function, the contrast can be improved.
Note that one layer or a plurality of layers having such a function may be provided, and the layer may be appropriately selected and used according to the use environment. In addition, the hard coat layer may have a form having both of these functions. If the substrate layer 13 has sufficient scratch resistance, the hard coat layer 14 may not be provided, or the hard coat layer 14 may be changed. A layer having these functions may be provided.

  In addition, although this embodiment and modification can also be used in combination as appropriate, detailed description is abbreviate | omitted. Further, the present invention is not limited by the above-described embodiments and the like.

DESCRIPTION OF SYMBOLS 10 Screen 11 Prism layer 111 Unit prism 112 Prism part 113 Base material part 12 Light-diffusion layer 13 Substrate layer 14 Hard coat layer 15 Mesh layer 16 Bonding layer

Claims (12)

A light diffusing member having a light diffusing action of diffusing light incident from one surface and exiting from the other surface,
A first thread-like member group consisting of a plurality of resinous thread-like members arranged in a first interval parallel to the sheet surface at a predetermined interval; and parallel to the sheet surface A net-like portion having a second thread-like member group composed of a plurality of resinous thread-like members arranged at a predetermined interval in a second direction different from the first direction;
The second thread-like member group is arranged more densely than the first thread-like member group;
A light diffusion member characterized by the above. The light diffusing member according to claim 1,
The light diffusing member, wherein the mesh portion is transparent or translucent. The light diffusing member according to claim 1 or 2,
Formed of a resin having a refractive index different from that of the resin forming the net-like portion, and provided with a base material layer serving as a base material of the light diffusion member,
The mesh portion is bonded to the base material layer or embedded in the base material layer;
A light diffusion member characterized by the above. In the light-diffusion member of any one of Claim 1- Claim 3,
The first direction and the second direction are orthogonal to each other;
A light diffusion member characterized by the above. In the light-diffusion member of any one of Claim 1- Claim 4,
The mesh portion has a thread diameter of 5 to 300 μm, an aperture ratio of 20 to 80%, a mesh number of 2 to 300 mesh / inch, and the mesh number in the second direction is the first direction. Larger than the number of meshes in
A light diffusion member characterized by the above. In the light-diffusion member of any one of Claim 1- Claim 5,
The network is formed of crystalline plastic;
A light diffusion member characterized by the above. In the light-diffusion member of any one of Claim 1- Claim 6,
The mesh opening of the mesh portion is filled with a resin having a refractive index different from that of the resin forming the mesh portion,
A light diffusion member characterized by the above. The light diffusing member according to any one of claims 1 to 7,
A plurality of unit prisms arranged on the incident side of the light diffusing member and having a light incident surface on which light is incident and a total reflection surface that totally reflects at least a part of light incident from the light incident surface in a predetermined direction are arranged. A prism layer formed by
A transmissive screen comprising: The transmission screen according to claim 8, wherein
The first direction is a vertical direction of the screen when the transmissive screen is used, and the second direction is a horizontal direction of the screen when the transmissive screen is used;
A transmissive screen characterized by The transmissive screen according to claim 8 or 9, wherein
A light diffusion layer containing a diffusing material is provided on the light exit side from the prism layer,
The mesh portion is located between the prism layer and the light diffusion layer in the thickness direction of the transmission screen;
A transmissive screen characterized by The transmission screen according to any one of claims 8 to 10, and
A support for supporting the transmission screen;
Interactive board with. An interactive board according to claim 11,
A light source unit that projects image light to the back of the transmissive screen;
A control unit for outputting video data to be displayed on the transmissive screen to a light source unit;
Interactive board system with

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