KR20060021755A - 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. A back surface comprising a light shielding print layer 4 formed to form a horizontal parallel line between the microprisms 5 and a microaspherical lens layer 9 formed long between the light shielding print layer 4. Provide a projection screen 1.

As described above, the rear projection screen according to the present invention has no reflection of reflection on the surface of the observation side even in bright environment such as sunlight, and can obtain a high-definition color image of a high black level, Of course, there is an effect that the screen can be configured at a low price, and there is an effect that can secure a superior viewing angle compared with the conventional.

Rear Projection Screen, Micro Aspheric Lens, Contrast, Viewing Angle, Micro Prism

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 illustrates a path of light beams projected on a rear projection screen according to an embodiment of the present invention.

5 is a cross-sectional view showing an angle microprism optical sheet of a rear projection screen according to another embodiment of the present invention.

6 is a perspective view showing an angle microprism light emitting sheet of a rear projection screen according to another 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 5 ': microprism 6: diffusion layer

7: adhesive layer 8, 8 ': optical sheet

9: fine aspherical lens 20: diffusion film                 

P: projector

The present invention relates to a rear projection screen, and more particularly, the image of the projector is received from the rear side, and is first refracted through an optical sheet on which microprisms are formed, and then diffused in a diffusion layer on the front optical film, and then wide. The present invention relates to a rear projection screen for viewing an image through a microspherical lens layer to have a viewing angle.

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. The first is that there is no surface reflection due to the low surface reflection of external light (sunlight or ambient light) on the image observer, and the second is that high contrast ratio is secured by securing 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, these screens cannot cope with the intensity of the reflected image or the external light reflected from the observer's surface under bright light such as sunlight, and the projected image seen by the observer becomes an unclear image with a weak contrast. There is a problem throwing away.

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.

In order to solve the above problems, the inventors of the present invention in the rear projection screen filed with the same as the present patent application, in the rear projection screen to receive the light beam from the rear to view the image from the front, the The screen is bonded to the transparent plate, the back of the transparent plate and the optical sheet formed with a plurality of micro-prism protruding to the rear in parallel to the left and right to refract light and to guide the front, the transparent film is bonded to the front of the transparent plate A diffuser film having a diffusion layer in which light rays refracted through the optical sheet are scattered in each direction and diffused in front and rear surfaces of the diffusion sheet, and formed on a top surface of the diffusion layer to form a horizontal parallel line between the microprisms of the optical sheet. It has been proposed a rear projection screen comprising a light shielding printing layer.

Such a screen has no reflection of reflections on the surface at the observation side even in bright environment such as sunlight, and can obtain a high-definition color image of high black level. By refracting first and then light diffusing, it is possible to construct a large screen with low light loss at a low price.

However, the microprisms formed on the optical sheet of such a rear projection screen are affected by the microprism because the light rays reaching each point on the projection screen are continuously changed according to the installation position (height) of the projector relative to the screen. The refracted light rays are horizontal to each other and do not face forward, but the direction to which the image is directed is different, so that a ghost phenomenon in which an image of multiple images is formed may appear.

In order to improve this, the inventors of the present invention, in the 'rear projection screen' filed with the same as the present patent application in the rear projection screen to receive the light beam from the rear to view the image from the front, the screen is a transparent plate, Thermo-compression on the back of the transparent plate is arranged in parallel to the left and right in order to refract the light beams to guide the front and the angle of the back of the transparent plate protruding to the rear is continuously changed vertically in the range of 5 ~ 65 degrees And an optical sheet having a plurality of angle microprisms having an overall gradient, and a diffusion layer adhered to the front surface of the transparent plate and diffused by light scattered in each direction through the optical sheet on the front and rear surfaces of the transparent film. Between the formed diffusion film and the biangular microprisms of the optical sheet on the upper surface of the diffusion layer. W horizontally it has proposed a rear-projection screen comprising a light-shielding printed layer formed achieve parallel lines.

Such a screen has an effect of preventing the ghost phenomenon by using biangular microprisms in response to the change of the incident angle of the light beam according to the position.                         

However, in the two rear projection screens as described above, it is difficult to secure a wide viewing angle because the light diffusion surface facing the observer is flat.

Accordingly, the present invention has been made 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. It is possible to obtain a colorful image, to configure a large screen at a low price, and to provide a new rear projection screen having a wider viewing angle.

The purpose of the above is a rear projection screen which receives the light beam from the rear to view the image from the front, the screen is a transparent plate, the thermocompression bonding to the back of the transparent plate and a plurality of in order to guide the light forward The optical sheet formed by the microprism protruding from the rear side in parallel to the left and right, and the diffusion layer formed on the front and rear surfaces of the transparent film and having a diffusion layer in which light rays refracted through the optical sheet are scattered in each direction and diffused. It can be achieved by including a film, a light shielding printing layer formed on the upper surface of the diffusion layer to form a parallel parallel line between the micro-prisms of the optical sheet and a fine aspherical lens layer formed between the light shielding printing layer long. have.

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 A diffusing film having a diffusion layer scattered in a direction to be diffused, a fine aspherical surface formed long between the light shielding printing layer and the light shielding printing layer formed on the upper surface of the diffusion layer so as to be parallel to each other between the microprisms of the optical sheet; It comprises a lens layer.

Here, the microprism is characterized in that the angle with respect to the back of the transparent plate is the same.

In addition, the microprism is characterized in that a plurality of biangular microprism having an overall gradient having an angle with respect to the back of the transparent plate continuously up and down.

The diffusion layer of the diffusion film is formed by applying a solution in which white particles and an acrylic binder are mixed and dried.

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

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. A microprism formed at regular intervals is shown, and reference numeral 4 also denotes a light shielding printing layer having a plurality of densely formed in the lateral direction, and reference numeral 9 denotes a fine aspherical lens layer formed long between the light shielding printing layers 4. .

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.

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 in the rear projection screen (1) to be able to see the image from the front by receiving a light beam from the rear In addition, the screen 1 is a transparent plate 3 having a thickness of 50 ~ 150㎛, and is thermally compressed on the back of the transparent plate 3 and arranged in parallel to the left and right in order to refract the light beam to guide the front Optical sheet having a thickness of 250 to 500 μm, including a plurality of micro prisms 5 having a size of 50 to 500 μm (proximal to the bottom of a triangular cross section or a gap between edges of neighboring micro prisms) 8 and a diffusion layer 6 adhered to the entire surface of the transparent plate 3 and on the front and rear surfaces of the transparent film 2 in which light rays refracted through the optical sheet 8 are scattered in each direction and diffused. Diffusion with a thickness of 50 ~ 150㎛ Light blocking printed layer having a thickness of 10 to 15 μm formed horizontally parallel to the film 20 and between the microprisms 5 of the optical sheet 8 on the upper surface of the diffusion layer 6 ( 4) and the micro-spherical lens layer 9 formed between the light-shielding printed layer 4 to be long. The microprism 5 has a constant angle with respect to the rear surface of the transparent plate 3.

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 2 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, the transparent plate (3) using the pane of the window as it is, the diffusion film 20 formed with the diffusion layer (6), the light-shielding printing layer (4) and the fine aspheric lens layer (9) around the center To the outside side of the window, and adhere or adhere the optical sheets 8 and 8 'on which the microprism 5 or the biangular microprism 5' is formed to the interior side of the window using a separate adhesive or adhesive. By means of 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. And as the transparent plate 3, a thing like 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.

5 and 6 are cross-sectional and perspective views showing a biangular microprism optical sheet 8 'that may be used in the rear projection screen 1 according to another embodiment of the present invention, wherein the biangular microprisms 5' are respectively shown in FIG. It can be seen that the angle α (β) (γ) formed with the back surface of the transparent plate 3 is continuously changed to have a gradient as a whole. In the present embodiment, as the shape of α> β> γ, the lower microprisms 5 'protrude more sharply so that the lower optical sheet 8' is formed as a whole. Will appear to have

By using such anisotropic microprisms 5 ', the light beam from the projector P, which is a point light source, can be refracted more precisely to the front, because the point light source is on the screen 1 from the point light source. The angle of incidence of the arriving light beam changes continuously depending on the position of the point light source and the position on the screen 1, so that the light beam can be deflected to the front only if the angle of each microprism 5 'is different accordingly. to be. This serves to make the image of the screen 1 brighter.

3 is a view showing a microprism optical sheet of a rear projection screen and its operation according to an embodiment of the present invention, in which light emitted from the projector P is caused by the microprisms 5 of the optical sheet 8. It can be seen that the bent, Figure 4 is a view showing the path of the light beam projected on the rear projection screen according to an embodiment of the present invention, the light beam emitted from the projector (P) is a fine prism of the optical sheet (8) (5) bent to pass through the transparent plate 3, and the light passing through the transparent plate 3 forms an image in the white diffusion layer 6 of the diffusion film (2) and the fine aspherical lens layer ( 9) the image of the projector P is wide-angle light diffused to provide the viewer with an image having a wide viewing angle.

As described above, the rear projection screen according to the present invention has no reflection of reflection on the surface of the observation side even in bright environment such as sunlight, and can obtain a high-definition color image of a high black level, Of course, there is an effect that the screen can be configured at a low price, and there is an effect that can secure a superior viewing angle compared with the conventional.

Claims (5)

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 comprising a light shielding printing layer 4 formed so as to form a horizontal parallel line therebetween and a microspherical lens layer 9 formed long between the light shielding printing layers 4 ( One). The rear projection screen (1) according to claim 1, wherein the microprism (5) has a constant angle with respect to the rear surface of the transparent plate (3). The method of claim 1, wherein the microprism (5) is characterized in that the angle with respect to the back surface of the transparent plate (3) is a plurality of biangular microprism (5 ') having a gradient as a whole. Rear Projection Screen (1) The rear projection screen (1) according to claim 1, wherein the diffusion layer (6) of the diffusion film (2) is formed by applying a solution in which white particles and an acrylic binder are mixed and dried. 5. The rear projection screen (1) according to claim 4, wherein the white particles are a mixture of titanium dioxide, silica, calcium carbonate and aluminum hydroxide, alone or in combination.

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