JP2007199566A - Transmissive screen - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a transmissive screen which has a congiguration capable of preventing the crushing of a lens shape of a lens sheet used for the screen, is inexpensive and can be used for a rear projection TV or the like. <P>SOLUTION: The transmissive screen is characterized in that a microlens array sheet on which unit lenses are two-dimensionally arranged at least on a half surface of a light-transmissive substrate is combined with a total reflection type Fresnel lens sheet made by forming total reflection type Fresnel lenses on which total reflection type Fresnel lenses are formed on a half surface of a light-transmissive substrate in the order from the light source side. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a transmissive screen used for a rear projection TV and the like, and more particularly to an inexpensive transmissive screen that prevents the lens shape of a lens sheet constituting the screen from being crushed.

  A conventional transmissive screen, for example, as proposed in Patent Document 1, is a non-lens of a Fresnel lens sheet in which light is projected from a projector serving as a light source onto the back of the screen and a diffusion plate is first bonded to the non-lens surface. Incident from the surface side and adjusted to parallel light. Next, the light enters a lenticular lens sheet provided with a minimal stripe using a black ink material, and a diffusion plate is bonded to the non-lens surface, and is strongly diffused in the horizontal direction. This diffused light is diffused in all directions by the diffusion layer bonded to the lenticular lens sheet, and a wide viewing area is obtained on the viewer side. A configuration including two diffusion layers is the mainstream.

  In a configuration using a refractive Fresnel lens sheet, when combined with a lenticular lens sheet or a microlens sheet, the lens surfaces face each other, and the blade is liable to be crushed. In addition, there is a problem that the cost increases due to the configuration including two diffusion layers.

If the diffusion layer of any of the lenticular lens sheet, microlens sheet or Fresnel lens sheet is removed in order to improve the above problem, the sheet will bend and the screen performance will be lowered in the conventional screen configuration.
JP 2004-118166 A

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an inexpensive transmissive screen having a configuration that prevents the lens shape of the lens sheet used in the screen from being crushed.

  In order to achieve the above object, that is, the invention according to claim 1 combines at least a microlens array sheet in which unit lenses are two-dimensionally arranged from the light source side and a total reflection type Fresnel lens sheet. It is the transmission type screen characterized by becoming.

  According to a second aspect of the present invention, in the microlens array sheet, unit lenses are two-dimensionally arranged on one side of a translucent substrate, and a matrix-like light shielding layer is formed on the opposite flat surface. The transmissive screen according to claim 1, wherein

  The invention according to claim 3 is characterized in that the Fresnel lens sheet has a total reflection type Fresnel lens formed on one side of a translucent substrate containing a light diffusion component. It is a transmissive screen.

  According to a fourth aspect of the present invention, there is provided a transmissive screen characterized in that a front plate is provided on the outermost layer serving as the observation surface of the transmissive screen according to any one of the first to third aspects. .

According to the present invention, from the light source side, at least the microlens array sheet in which the unit lenses are two-dimensionally arranged and the total reflection type Fresnel lens sheet are combined so that the lens surfaces do not contact each other. By making the light transmissive component of the Fresnel lens sheet a light diffusing component, the lens shape of the lens sheet can be prevented from being crushed and a light diffusing function can be imparted to the light transmissive substrate. An inexpensive transmission type screen can be provided.

  Hereinafter, an example of an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic cross-sectional view in the horizontal direction showing an example of the configuration of the transmission screen of the present invention. FIG. 2 is a schematic explanatory view for explaining an optical path when outgoing light is parallel light in a horizontal sectional view of a part of the transmission screen of the present invention. FIG. 3 is a schematic explanatory view for explaining the optical path at the end of the screen in the horizontal sectional view of the transmission screen of the present invention.

  As shown in FIG. 1, a transmissive screen as an embodiment of the present invention includes a microlens array sheet (1) in which at least unit lenses are two-dimensionally arranged from the light source side, and a total reflection type Fresnel lens sheet. (2) in combination. The microlens array sheet (1) is formed with a microlens array (A) in which unit lenses are two-dimensionally arranged on one side of the translucent substrate (B), and photosensitive on the opposite flat surface. A matrix-shaped light shielding layer (D) is formed through a layer (C) made of a resin material. On the other hand, in the total reflection type Fresnel lens sheet (2), the total reflection type Fresnel lens (E) is formed on one side of the translucent substrate (F) containing the light diffusing component, and the translucent substrate. (F) has a light diffusing function and is configured so that the lens surfaces of the microlens array sheet (1) and the total reflection type Fresnel lens sheet (2) do not contact each other.

  As shown in FIG. 2, in the transmissive screen of the present invention as an embodiment, the projection light from the projector first enters the lens surface of the microlens array sheet. The lens design differs depending on the incident angle of light, and in the region where the incident angle is large, the shape of the microlens is sharp and sharp, but in the region where the incident angle is small, the lens has an elliptical or perfect circular cross section. These micro lenses have the same focal length even if they have different shapes. The light incident on the microlens passes through the matrix-shaped light shielding layer and is diffused in all directions to obtain a uniform light intensity over the entire screen.

  The light diffused by the microlens enters the lens surface of the total reflection type Fresnel lens sheet, and the optical axis is adjusted to diffused light or parallel light perpendicular to the screen and is emitted to the viewer side. Since the total reflection type Fresnel lens is used here, the light from the projector light source with a steep incident angle diffused by the microlens is slightly larger than the design angle. Even if it becomes, it is possible to transmit light to the observer side by total reflection. The light transmissive component of the total reflection type Fresnel lens sheet contains a light diffusing component and has a light diffusing function. In addition, the film and board which have a light-diffusion function can also be bonded to a translucent board | substrate, without making a translucent board | substrate contain a light-diffusion component. The optimum diffusion characteristics (Haze) and thickness are selected as necessary.

  Since the transmitted light is spread by the microlens array sheet, as shown in FIG. 3, the total reflection type Fresnel lens sheet is made larger than the microlens array sheet so that the total diffused light is incident, or both lens sheets are the same size. Therefore, it is necessary to determine the size of the microlens array sheet so that light from the light source does not enter the end of the microlens array sheet. When light is incident on the entire surface of the microlens array sheet and transmitted through a total reflection type Fresnel lens sheet of the same size, the light at the end of the microlens array sheet does not pass through the total reflection type Fresnel lens sheet and is lost.

  A front plate can also be provided on the outermost layer serving as the observation surface of the transmission screen.

  As the translucent substrate constituting the transmissive screen, thermoplastic resin materials such as acrylic resin, polycarbonate resin, styrene resin, acrylic / styrene copolymer resin, or inorganic material containing silicate as a component Can also be used. It is essential that all materials have high light transmittance.

  The light diffusing material as a light diffusing component contained in the translucent substrate constituting the total reflection type Fresnel lens sheet is alumina, silica, etc. for inorganic materials, acrylic resin, styrene resin, polycarbonate resin, acrylic resin for organic materials / Styrene copolymer resin is preferred.

  Moreover, the film and board which have a light-diffusion function are obtained by mixing and apply | coating said diffusing material in the following resin material.

  Resin materials include acrylic resin, polyurethane resin, polyester resin, polyvinyl chloride resin, polyvinyl acetate resin, polystyrene resin, polycarbonate resin, polypropylene resin, polyarylate resin, polysulfone It consists of a single substance or a mixture selected from a resin, a polyethersulfone resin, an epoxy resin, a polyolefin resin, a fluorinated polyimide resin, a norbornene resin, a nylon resin, and the like.

  The lens part of the microlens array is coated or injected with an ionizing radiation resin such as an ultraviolet curable resin (UV resin) or an electron beam curable resin on the concavo-convex forming surface of a press method, a casting method, or a flat stamper or roll stamper. It can be obtained by a method in which a base material is disposed thereon, and after the curing treatment, is released from the stamper.

  The microlens array sheet is formed by forming a microlens array (unit lens group) on one side of a translucent substrate with a cured product of a radiation curable resin, and on a flat surface on the opposite side to a non-condensing part of each unit lens. In this structure, a matrix-shaped light shielding layer is formed at a corresponding position via a positive photosensitive adhesive layer. In the formation of the light-shielding layer, the positive photosensitive adhesive layer is bonded to a flat surface opposite to the lens surface of the microlens array sheet, and exposure is performed by applying UV light from the microlens array side. Instead, it must be irradiated so that it enters the microlens array at an angle similar to the incident angle from the light source. By doing so, a light shielding layer through which light from the light source is sufficiently transmitted is formed.

  The microlens array refers to a lens group in which single lenses having the same shape are regularly arranged, or a lens group in which single lenses having different shapes are randomly arranged without a gap.

  The total reflection type Fresnel lens sheet can be manufactured by a conventionally known manufacturing method. There is no limitation on the center part or offset.

It is a schematic cross section of the horizontal direction which shows an example of a structure of the transmissive screen of this invention. It is a schematic explanatory drawing explaining the optical path in case the emitted light is parallel light in the horizontal sectional view of a part of transmission screen of the present invention. It is a schematic explanatory drawing explaining the optical path of the screen edge part in sectional drawing of the horizontal direction of the transmission type screen of this invention.

Explanation of symbols

A: Microlens array B: Translucent substrate of microlens array sheet C: Layer made of photosensitive resin material D: Light shielding layer E: Total reflection type Fresnel lens F: Translucent substrate of total reflection type Fresnel lens sheet ( Including light diffusing components)
G: Light source

Claims (4)

  A transmission screen comprising a combination of at least a microlens array sheet in which unit lenses are two-dimensionally arranged and a total reflection type Fresnel lens sheet from the light source side.   2. The microlens array sheet, wherein unit lenses are two-dimensionally arranged on one side of a translucent substrate, and a matrix-like light shielding layer is formed on a flat surface opposite to the unit lens. Transmissive screen.   The transmissive screen according to claim 1 or 2, wherein the Fresnel lens sheet comprises a total reflection type Fresnel lens formed on one side of a translucent substrate containing a light diffusion component.   A transmissive screen comprising a front plate on the outermost layer serving as an observation surface of the transmissive screen according to claim 1.

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