KR100693330B1 - Rear projection screen - Google Patents

Abstract

The present invention provides a rear projection screen (1) in which a light beam is projected from the rear surface so that an image can be viewed from the front side, wherein the screen (1) is thermocompressed to the transparent plate (3) and the rear surface of the transparent plate (3). And a plurality of microprisms 5 protruding to the rear side in parallel to the left and right in order to refract light and guide forward, and adhered to the front surface of the transparent plate 3 and A diffusion film 20 having a diffusion layer 6 in which light rays refracted through the optical sheet 8 are scattered in each direction and diffused in front and rear surfaces, and an upper surface of the diffusion layer 6 of the optical sheet 8. Provided is a rear projection screen (1) comprising a light shielding printing layer (4) formed so as to form a horizontal parallel line between the microprisms (5).

As described above, the rear projection screen according to the present invention has no reflection of reflection on the surface at the observation side even in a bright environment such as sunlight, and can obtain a high-definition color image of a high black level, Since the light is first refracted through the microprism optical sheet and then light is diffused, a large screen with low light loss can be configured at a low price.

 Contrast, Viewing Angle, Fine Prism, Diffusion Film, Rear Projection Screen

Description

Rear projection screen

1 illustrates an arrangement of a rear projection screen according to an embodiment of the present invention.

2 is a longitudinal sectional view of a rear projection screen according to an embodiment of the present invention;

3 is a view showing the microprism optical sheet and its operation of the rear projection screen according to an embodiment of the present invention;

4 is a view showing a light-shielding printed layer of a rear projection screen and its function according to an embodiment of the present invention.

5 is a perspective view of a fine prism optical sheet of a rear projection screen according to an embodiment of the present invention;

※ Explanation of code about main part of drawing ※

1: rear projection screen 2: transparencies

3: transparent plate 4: shading printed layer

5: microprism 6: diffusion layer

7: adhesive layer 8: optical sheet

20: diffusion film

P: projector

The present invention relates to a rear projection screen, and more particularly, a front surface is obtained by receiving an image of a projector from a rear side and first refracting it through an optical sheet on which a microprism is formed and then diffusing it in a diffusion layer on the front optical film. It relates to a rear projection screen that allows viewing of the image through.

In order to obtain a projected image by a projector or the like, a projection screen is widely used. This projection screen includes a transmissive rear projection screen and a reflective projection screen. Two important elements are required for such a projection screen. First, there is no surface reflection due to the low surface reflection of external light (sunlight or ambient light) on the image observer, and second, the high contrast ratio must be secured by securing a black level.

The present invention is a method of a transmissive screen for projecting a projection image of a projector on an inner surface of a display window or a glass window, and projects the projector image toward the rear of the screen. This has been put into practical use as a rear transmissive screen for reproducing guidance, advertisements, video information and the like.

However, such a conventional screen cannot cope with the intensity of the reflected image or the external light reflected from the observer's glass surface under bright light such as sunlight, and the projected image seen from the observer's side is an unclear image with a weak contrast. There is a problem that becomes.                         

In the case of a conventional rear projection screen, a screen of a multilayer sheet consisting of a light diffusing layer from a projector side and a microprism optical sheet that refracts light rays from the projector to the front is printed with light-shielding ink on the upper surface of the microprism. Although the reduction in contrast due to external light is reduced, it is difficult to manufacture light-shielding ink on the upper surface of the microprism, and the light emitted from the projector is first diffused through the diffusion layer and then refracted to the viewer through the microprism optical sheet. Therefore, there is a problem of causing light loss due to the light-shielding printed layer printed on the front.

In addition, as the large-screen video display device, a structure in which LED lamps are conventionally arranged over a display area is widely used, but has a problem that it is very expensive and takes a lot of installation work.

Accordingly, the present invention was created to solve the above problems, and an object of the present invention is to provide a high black level high precision with no reflection of reflection on the surface at the observation side, even in a bright environment such as sunlight. A color image can be obtained, and the light beam from the projector is first refracted to the front through the microprism optical sheet, and then the optical diffusion is performed through the light diffusing layer to minimize the light loss, and the light diffusing layer to flatten the light-shielding ink. The printing on the above provides a new rear projection screen that can be easily manufactured by constructing a large screen at a low cost.

The above object is a rear projection screen for projecting a light beam from the rear to view an image from the front, wherein the screen is thermally compressed on the back of the transparent plate and the back of the transparent plate to deflect the light to guide it forward. The optical sheet formed with a plurality of micro-prism protruding to the rear in parallel to the left and right, and the diffusion layer is formed on the front and rear surfaces of the transparent film and the light rays refracted through the optical sheet scattered in each direction to diffuse It can be achieved by including a diffusion film and a light shielding printing layer formed on the upper surface of the diffusion layer to form a parallel parallel line between the micro-prism of the optical sheet.

The rear projection screen of the present invention for achieving the above object is a rear projection screen to receive the light beam from the rear to view the image in the front, wherein the screen is thermally compressed to the transparent plate, and the back of the transparent plate The optical sheet formed with a plurality of micro-prism protruding to the rear side in parallel to the left and right to refract the light to the front, and the light is bonded to the front of the transparent plate and the light is refracted through the optical sheet on the front and rear surfaces of the transparent film And a diffusion film having a diffusion layer scattered and diffused in a direction, and a light shielding printing layer formed on an upper surface of the diffusion layer to form a horizontal parallel line between the microprisms of the optical sheet.

Here, the diffusion layer formed on the diffusion film is characterized in that formed by coating and drying a solution of a mixture of white particles and an acrylic binder.

In addition, the white particles are characterized in that the titanium dioxide, silica, calcium carbonate and aluminum hydroxide alone or a plurality of selected and mixed.                     

Hereinafter, with reference to the accompanying drawings, preferred embodiments of the present invention will be described in detail. While many specific details are set forth in order to provide a more general understanding of the invention, such as the following description and the annexed drawings, these specific details are illustrated for the purpose of illustrating the invention and are not meant to limit the invention thereto. And a detailed description of known functions and configurations that may unnecessarily obscure the subject matter of the present invention will be omitted.

1 is a view showing the arrangement of a rear projection screen according to an embodiment of the present invention, wherein reference numeral 1 designates a rear projection screen according to a preferred embodiment of the present invention, and reference numeral 5 designates a plurality of densely in the lateral direction. The formed microprism is shown, and reference numeral 4 also denotes a light shielding printed layer having a plurality of densely formed in the transverse direction.

The observer is outdoors based on a window (show window), and the rear projection screen 1 according to the embodiment of the present invention is installed indoors, and the projector P that shoots light beams for making an image is behind the screen 1. It is highly installed on the ceiling off. Therefore, observers can view the image of the screen 1 through the window outdoors.

2 is a longitudinal sectional view of a rear projection screen according to an embodiment of the present invention, the rear projection screen 1 of the present invention is a transparent plate (3) having a thickness of 50 ~ 150㎛, and of the transparent plate (3) It is thermocompressed on the back and is arranged in parallel from side to side to refract light and guides it forward, and has a size of 50 to 500 μm (proximal to the bottom of a triangular cross section or the gap between the edges of neighboring microprisms). It includes a plurality of micro-prism (5) having an optical sheet 8 having a thickness of 250 ~ 500㎛, and the optical sheet is bonded to the front surface of the transparent plate 3 and the front and rear surfaces of the transparent film (2) 8) a diffusing film 20 having a thickness of 50 to 150 μm with a diffusion layer 6 in which light rays refracted through the light are scattered and diffused in each direction, and the optical sheet 8 on the upper surface of the diffusion layer 6. Parallel lines between the microprisms 5 of It may be configured to include a light shielding printing layer 4 having a thickness of 10 ~ 15㎛ formed to achieve.

The transparent plate 3 preferably uses a high light transmittance such as polymethyl methacrylate (PMMA) sheet, and uses a flexible material for both the transparent film 2 and the optical sheet 8. By doing so, it is preferable that the rear projection screen 1 according to the present invention be rolled up and stored as a whole.

However, the adhesive layer 7 between the transparent plate 3 and the diffusion film 20 may form an adhesive layer using an adhesive, in this case, the diffusion film 20 and the optical sheet around the transparent plate 3. (8) Since it is possible to attach and detach, using the glass plate of the window as it is transparent plate 3 as it is, and the diffusion film 20 formed with the diffusion layer 6 and the light-shielding printing layer (4) is adhered to the outdoor side of the window, The optical sheet 8 on which the microprism 5 is formed may be attached or adhered to the interior side of the window using a separate adhesive or an adhesive to serve as the rear projection screen 1.

In addition, the diffusion layer 6 formed on the diffusion film 20 is formed by coating and drying a solution in which a white particle and an acrylic binder are mixed, which is a general method. As the transparent plate 3, one such as polyethylene terephthalate (PET) or polycarbonate (PC) can be used.                     

The white particles may be a mixture of titanium dioxide, silica, calcium carbonate and aluminum hydroxide alone or in plurality.

3 is a view showing a micro-prism optical sheet and its operation of the rear projection screen according to an embodiment of the present invention, Figure 5 is a perspective view of the micro-prism optical sheet, the light emitted from the projector (P) is the optical sheet ( It can be seen that due to the microprisms 5 of 8) are bent toward the transparent plate 3, the same shape and size (the size of the base of the triangular cross section or the distance between the edges of neighboring microprisms is 50 It can be seen that the prisms 5 having a diameter of ˜500 μm are in a continuous arrangement on the optical sheet 8.

4 is a view illustrating a light shielding printing layer of a rear projection screen according to an embodiment of the present invention and its operation, wherein sunlight (external light) is transmitted through the front surface of the rear projection screen 1 according to an embodiment of the present invention. Without reflecting, it is mostly absorbed by the light-shielding printed layer 4, thereby preventing the viewer from seeing the image properly.

The light-shielding printed layer 4 has been mentioned above, but is not formed to face the microprisms 5 but is formed so as not to block the light refracted by the microprisms 5 between them. Therefore, a set of dense linear images forms a single image in which light rays refracted through the microprisms 5 diffuse and image in the diffusion layer 6 having the light shielding printing layer 4 formed thereon. .

That is, the light rays emitted from the projector P are refracted by the microprism 5 of the optical sheet 8 to pass through the transparent plate 3, and the light rays passing through the transparent plate 3 are diffused film 20. Is formed in the diffusion layer 6 having a white color, and the image of the projector P is wide-angled and diffused by the diffusion layer 6 to provide an observer with an image having a wide viewing angle. will be.

As described above, the rear projection screen according to the present invention has no reflection of reflection on the surface at the observation side even in a bright environment such as sunlight, and can obtain a high-definition color image of a high black level, Since the light is first refracted through the microprism optical sheet and then light is diffused, a large screen with low light loss can be configured at a low price.

Claims (3)

In a rear projection screen (1) in which a light beam is projected from the rear surface so that an image can be viewed from the front, the screen (1) is thermally compressed to the transparent plate (3) and the rear surface of the transparent plate (3), A plurality of micro-prism (5) is protruded to the rear in parallel to the left and right to be refracted to guide the front and the front of the transparent plate 3 is bonded to the front and rear surfaces of the transparent film (2) Diffusion film 20 having a diffusion layer 6 in which light rays refracted through the optical sheet 8 are scattered and diffused in each direction, and fine prisms of the optical sheet 8 on the upper surface of the diffusion layer 6. (5) a rear projection screen (1), characterized in that it comprises a light shielding printing layer (4) formed so as to form a parallel line horizontally therebetween. The rear projection screen (1) according to claim 1, wherein the diffusion layer (6) of the diffusion film (20) is formed by applying a solution in which a mixture of white particles and an acrylic binder is mixed and dried. 3. The rear projection screen (1) according to claim 2, wherein the white particles are a mixture of titanium dioxide, silica, calcium carbonate and aluminum hydroxide, alone or in combination.

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