KR20120042477A - Front projection screen and projection system comprising the same - Google Patents

Abstract

PURPOSE: A front projection screen and a projection system including the same are provided to prevent a reduction of a contrast ratio due to light irradiating into an area excluding a reflection surface because light passing through a non-reflective surface disappears inside a lens unit by forming the lens unit and base unit using a black colored resin. CONSTITUTION: A front projection screen and a projection system including the same comprise a base unit and lens unit(20). The lens unit comprises a reflection surface(22) diffusing and reflecting light to one surface of the base unit and a non-reflective surface(24). A lens of which the cross section is a triangularly shaped is arranged in the lens unit as a form of successive concentric circles. The tilt angle of the reflective surface of the lens increases further from the center of the concentric circles. The tilt angle of the reflection of the lens closest to the center of the concentric circle is 1 to 10 degrees. The tilt angle of the reflection of the lens the farthest from the center of the concentric circle is 15 to 45 degrees.

Description

FRONT PROJECTION SCREEN AND PROJECTION SYSTEM COMPRISING THE SAME}

The present invention relates to a front projection screen and a projection system including the same, and more particularly, to a space-saving projection screen having a high image quality and a short distance between the projector and the screen, and a projection system including the same.

Projection system is a device that implements the screen by reflecting the light emitted from the projector on the screen, conventionally used in a large space such as a conference room or classroom. However, in recent years, as the projection apparatus has become smaller and the price is lowered, the tendency to use it for home use such as a home theater has increased.

However, the conventional projection system has a problem that the contrast ratio is lower than that of the TV, and the screen is hard to see due to external light reflection in a bright place. Therefore, it is urgent to improve the image quality in order for the projection system to become popular.

In addition, in the conventional projection system, the distance between the projector and the screen required for displaying the screen on the screen is long, which consumes a lot of space, and as a result, it is inadequate for home use.

In addition, the screen used in the conventional front projection system, there is a problem that the manufacturing process is complicated, and as a result, the manufacturing cost is high, the price competitiveness is low.

The present invention is to solve the above problems, the manufacturing process is simple, the manufacturing cost is low, but can implement a good image quality, the front projection screen having a small space required for installation and a projection system including the same To provide.

To this end, the present invention is a substrate; And a lens unit including a reflection surface and a non-reflection surface for diffusing and reflecting light on one surface of the base portion, wherein the lenses having triangular cross sections are arranged in a concentric arc shape in a continuous manner. Increasing away from the center of the concentric circles, the inclination angle of the reflective surface of the lens closest to the center of the concentric circles is 1 to 10 degrees, the inclination angle of the reflective surface of the lens farthest from the center of the concentric circles is 15 to 45 degrees Provide a screen.

In this case, at least one of the base portion and the lens portion is preferably formed of a black resin, and the reflecting surface is preferably made of a metal or an inorganic thin film.

In addition, irregular irregularities may be formed on the surface of the reflective surface, wherein the irregularities preferably have a height of about 0.5 to 5 μm. In addition, the reflection haze of the reflective surface is preferably about 20 to 100%.

On the other hand, the front projection screen of the present invention may further include a transparent protective layer on the lens portion, in this case, the inclination angle of the reflective surface of the lens closest to the center of the concentric circles is 1 to 5 degrees, the center of the concentric circles It is preferable that the inclination angle of the reflecting surface of the lens farthest from 15 to 30 degrees.

On the other hand, when the transparent protective layer is not formed, the inclination angle of the reflective surface of the lens closest to the center of the concentric circles is 5 to 10 degrees, and the inclination angle of the reflective surface of the lens farthest from the center of the concentric circles is 30 to 45 degrees. It is preferable that it is about degree.

On the other hand, in the case of the front projection screen of the present invention, the center of the concentric circle is preferably located outside the front projection screen.

In another aspect, the present invention provides a projection system comprising the front projection screen and a projector for projecting a screen onto the screen. At this time, the distance between the front projection screen and the projector is preferably about 390 to 550mm.

The front projection screen of the present invention uses a black resin to form the lens portion and / or the substrate portion, so that light passing through the non-reflective surface is lost inside the lens portion. Therefore, there is no manufacturing process for a separate treatment on the non-reflective surface, it is possible to prevent the lowering of the contrast ratio due to light incident to the region other than the reflective surface.

In addition, when the irregularities are formed on the reflective surface, it is possible to reduce the additional diffusion member for image formation, and the light efficiency is improved because the degree of light diffusion and the direction of diffusion are easy to adjust.

In addition, the front projection screen of the present invention can realize a space-saving projection system because the horizontal distance required between the projector and the screen is shortened by positioning the center of the concentric arc outside the screen.

1 is a view showing an embodiment of the front projection screen of the present invention.
2 and 3 are cross-sectional views of the front projection screen of the present invention.
4 is a view for explaining the lens arrangement of the front projection screen of the present invention.
5 is a view for explaining the diffuse reflection surface of the front projection screen of the present invention.
6 is a view for explaining a projection system of the present invention.

Hereinafter, the present invention will be described in more detail with reference to the drawings.

However, the following drawings are made in order to better understand the present invention, but are only one embodiment of the present invention, and the present invention is not limited thereto. In addition, the same reference numerals in the following drawings represent the same components, for the sake of ease of explanation the components shown in the drawings may be exaggerated, reduced or omitted.

1 to 5 show embodiments of the front projection screen of the present invention.

As shown in FIG. 1, the substrate unit 30 and the lens unit 20 are included.

The substrate portion 30 is to support the screen and to impart strength, and plastic substrates generally used in the art may be used. For example, a polycarbonate film, an acrylic film, a cellulose film, a cycloolefin film, or the like may be used as the base part 30 of the present invention without limitation. In addition, the substrate portion 30 may be formed of a black resin, if necessary. The black resin refers to a resin produced by mixing a black pigment or the like with a curable resin. When the base part is formed using the black resin, the light incident on the non-reflective surface is absorbed and lost by the black resin to improve the contrast ratio. Is more effective.

On the other hand, a lens unit 20 for reflecting the light projected from the projector in the direction of the viewer is formed on one surface of the base unit 30.

As illustrated in FIG. 1, the lens unit 20 is formed by arranging lenses including a reflection surface 22 and a non-reflection surface 24 for diffusing and reflecting light in a continuous concentric arc shape.

In this case, the lens unit 20 may be manufactured using a curable resin generally used in the art, or may be formed of the black resin. Black resin refers to a resin produced by mixing a black pigment or the like with a curable resin. When the lens part is formed using the black resin, the light incident on the non-reflective surface is lost in the lens part due to the black resin to reduce the contrast ratio. More effective to improve In addition, since it is possible to remove external light through the non-reflective surface without going through a separate process such as applying black ink to the non-reflective surface, there is an effect of simplifying the screen manufacturing process. At least one of the base portion 30 and the lens portion 20 is preferably formed of a black resin.

On the other hand, the lenses have a triangular shape in the cross-section, the two hypotenuses of the triangle is the reflective surface 22 and the non-reflective surface 24, respectively. 2 shows an enlarged view of the lens unit 20 of the present invention. As shown in FIG. 2, the reflective surface 22 may be formed of a thin film of a high reflectance metal (for example, aluminum or silver) or an inorganic material (for example, titanium dioxide). The metal thin film or the inorganic thin film may be formed by a thin film forming method generally known in the art, for example, a deposition or coating method.

On the other hand, the reflective surface 22 is preferably a reflection haze of about 20% to 100%. If the reflection haze is less than 20%, the image incident from the projector may not be sufficiently formed to narrow the viewing range, and the lamp of the projector may be viewed as it is, resulting in hot spots where local glare is felt.

Meanwhile, the reflective surface may include irregular irregularities on its surface, as shown in FIG. 5, as necessary. As such, when irregular irregularities are formed on the reflective surface, it is possible to easily adjust the reflection haze and the diffusion direction, thereby improving the light utilization efficiency. In this case, the unevenness formed on the surface of the reflective surface is preferably about 0.5 to 5㎛ in height, and the shape of the unevenness is preferably in the form of a smooth convex lens, as shown in FIG. The lens is more preferably in the form of a width wider than the height.

On the other hand, as described above, the reflective surface having irregular irregularities is further processed into an irregular spherical lens shape through a sandblasting method, etc. in a mold in which the shape of the lens portion is engraved, and then a curable resin is injected into the mold to form the lens portion. It can be prepared by a method of forming a metal or inorganic thin film thereon.

On the other hand, the front projection screen of the present invention, as shown in Figure 3, may further include a transparent protective layer 40 for protecting the lens portion on the lens portion. At this time, the transparent protective layer 40 should just be light-transmissive, The material is not specifically limited.

The present invention is characterized in that the inclination angle of the lenses arranged in the form of concentric arcs is configured to vary depending on the distance from the center of the concentric circles. More specifically, the inclination angle (θ) of the reflecting surface becomes larger as the lens is farther from the center of the concentric circles, and the inclination angle of the reflecting surface of the lens closest to the center of the concentric circles is about 1 to 10 degrees, at the center of the concentric circles. It is preferable that the inclination angle of the reflection surface of the furthest lens is about 15 to 45 degrees. At this time, the inclination angle θ means, as shown in Figure 2, the angle in the direction perpendicular to the film surface from the surface of the optical film of the present invention.

When the lens unit has the inclination angle as described above, light incident from the upper direction of the screen is reflected by the lens unit in the bottom direction, and light incident from the lower direction of the screen is reflected by the lens unit in the front direction. Will have characteristics. In such a case, since external light such as fluorescent light or sunlight incident in the upper direction of the screen and light emitted from the projector incident in the lower direction of the screen are not mixed, contrast reduction due to external light can be improved.

On the other hand, the inclination angle of the reflective surface may vary somewhat depending on the configuration of the screen. For example, as shown in FIG. 2, in the case of the screen on which the protective layer 40 is not formed, the inclination angle of the reflection surface of the lens closest to the center of the concentric circle is about 5 to 10 degrees, preferably 5 to 9 degrees, More preferably, it is about 6 to 8 degrees, and the inclination angle of the reflecting surface of the lens farthest from the center of the concentric circle is 30 to 45 degrees, preferably 34 to 42 degrees, more preferably 36 to 40 degrees. . On the other hand, as shown in FIG. 3, in the case of the screen on which the protective layer 40 is formed, the path of incident light is slightly changed due to the refractive index of the transparent protective layer (typically 1.4 to 1.6). Rather small is desirable. Specifically, when the transparent protective layer 30 is formed, the inclination angle of the reflecting surface of the lens closest to the center of the concentric circle is about 1 to 10 degrees, preferably 1 to 5 degrees, more preferably 2 to 4 degrees. The inclination angle of the reflecting surface of the lens farthest from the center of the concentric circle is 15 to 30 degrees, preferably 18 to 25 degrees, more preferably 20 to 23 degrees.

Further, in the case of the front projection screen of the present invention, as shown in Figure 4, it is preferable that the center of the concentric circle is formed so as to be located outside the front projection screen. In this case, the focal length required for image formation on the screen is shortened, and as a result, the horizontal distance between the screen and the projector can be narrowed, thereby saving the space required for installing the projection system.

Next, the projection system of the present invention will be described.

6 shows a projection system of the present invention. As shown in Fig. 6, the projection system of the present invention comprises the front projection screen 1 and the projector 2 described above.

Since the front projection screen 1 is the same as described above, the detailed description is omitted.

On the other hand, the projector 2 is a device for projecting the screen on the screen 1, in the present invention, it is preferable to use a short focus projector having a short focal length. When using a short throw projector, the distance between the projector and the screen is short, so that a space-saving projection system can be realized. More specifically, in the projection system of the present invention, the horizontal distance between the projector and the screen is preferably about 390 to 550 mm.

In addition, the projector 2 is disposed at a lower position than the screen 1, and preferably in a manner of projecting light from the bottom to the top direction. When the front project screen of the present invention is used together with a projector that projects light from the bottom of the screen, the reflection path of the external light irradiated from the upper part of the screen and the light projected from the projector is changed by the screen lens unit, thereby reducing the contrast ratio due to external light. Since it can be prevented, there is an advantage that a clear screen can be realized even in a bright environment.

On the other hand, in the projector, the light projection angle has a minimum angle α of 10 ° to 20 °, preferably 10 ° to 15 °, more preferably 12 ° to 14 °, and a maximum angle β of 60 to 80. °, Preferably it is 65 degrees-75 degrees, More preferably, it is about 68 degrees-73 degrees. If the minimum angle of the projector is less than 10 °, the distinction between the external path and the light path of the light incident from the projector may be reduced, resulting in a decrease in contrast ratio. If the maximum angle of the projector exceeds 80 °, keystone correction ( Trapezoidal image correction) becomes difficult and causes deterioration of image quality.

1: Screen
2: projector
10: description
20: lens unit
22: reflecting surface
24: non-reflective surface
30: protective layer

Claims (13)

Base unit; And
And a lens unit including a reflective surface and a non-reflective surface for diffusing and reflecting light on one surface of the base portion, the lenses having triangular cross sections arranged in a concentric circular arc shape.
The inclination angle of the reflective surface of the lens increases as the distance from the center of the concentric circle,
Front projection screen in which the inclination angle of the reflecting surface of the lens closest to the center of the concentric circles is 1 to 10 degrees, and the inclination angle of the reflecting surface of the lens farthest from the center of the concentric circles is 15 to 45 degrees.
The method of claim 1,
At least one of the lens unit and the base unit is formed of a black resin front projection screen.
The method of claim 1,
The reflective surface is a front projection screen made of a metal or inorganic thin film.
The method of claim 1,
Irregular irregularities are formed on the surface of the reflective surface.
The method of claim 4, wherein
The unevenness is a front projection screen having a height of 0.5 to 5㎛.
The method of claim 1,
The front projection screen further comprises a transparent protective layer on the lens portion.
The method of claim 1,
Front projection screen in which the inclination angle of the reflecting surface of the lens closest to the center of the concentric circles is 5 to 10 degrees, and the inclination angle of the reflecting surface of the lens farthest from the center of the concentric circles is 30 to 45 degrees.
The method of claim 6,
Front projection screen with a tilt angle of 1 to 5 degrees for the reflective surface of the lens closest to the center of concentric circles and a tilt angle of 15 to 30 degrees for the reflective surface of the lens farthest from the center of the concentric circles.
The method of claim 1,
Reflective haze of the reflective surface is 20 to 100%.
The method of claim 1,
A front projection screen with the center of the concentric circles positioned outside of the front projection screen.
The front projection screen of claim 1 and
And a projector for projecting a screen onto the front projection screen.
The method of claim 11,
And the distance between the front projection screen and the projector is between 390 and 550 mm.
The method of claim 11,
And the projector is disposed at a lower position than the screen and projects light from the bottom to the top.

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