WO2017004788A1

WO2017004788A1 - Front projection screen

Info

Publication number: WO2017004788A1
Application number: PCT/CN2015/083440
Authority: WO
Inventors: 乔俊枫; 张昭宇
Original assignee: 北京大学深圳研究生院
Priority date: 2015-07-07
Filing date: 2015-07-07
Publication date: 2017-01-12

Abstract

A front projection screen comprises a plurality of basic imaging units (20) compressed in turn to form an imaging layer (10). The plurality of basic imaging units (20) are concentric arcs, wherein each of the basic imaging units (20) comprises, in turn and from an outer circle to an inner circle of each of the basic imaging units, a first transmission layer (201) configured to transmit light and a reflection layer (203) configured to reflect the light. The reflection layer (203) is configured to be a slope having a higher front portion and a lower back portion. The screen can effectively prevent environmental light from being reflected into a viewing zone.

Description

Front projection screen

Technical field

[0001] The present invention relates to a projection screen, and more particularly to a front projection screen that attenuates ambient light interference with a projected image.

BACKGROUND OF THE INVENTION

[0003] The quality of the front projection image is related to the distance from the projector to the screen, the size and structure of the screen, and the intensity of the ambient light. As the projected image increases, the brightness of the light projected by the projector will drop sharply; when the ambient light is strong, the quality and contrast of the projected image will be greatly reduced.

[0004] Increasing the output power of the projector can effectively improve the quality and contrast of the projected image, and the viewer's viewing effect can be improved, but increasing the power increases the workload of the projector and reduces the life of the projector. Even if the power is increased, the viewing intensity of the audience is still not ideal when the ambient light is strong.

[0005] Referring to FIG. 1, the ambient light that affects the quality of the projected image mainly includes the indoor light 4 above the screen 1 and the external light on the side of the screen 1 (for example, the sunlight 5 is incident through the window 6). The viewer 2 can not only see the image light reflected by the projector 3 onto the screen 1, but also can see the ambient light projected onto the screen 1 so that the viewer can often see that the screen is bright. The spot or part of the area is blurred, which affects the viewing effect.

[0006] Ordinary front projection screens are mostly based on Lambertian scattering, which scatters the projection light projected onto the screen, but a lot of light is scattered out of the observer's visual range, resulting in a decrease in image quality and contrast, plus the influence of ambient light. , the viewing effect has dropped significantly.

[0007] Starting from the optical structure of the screen, the quality of the projection can be improved to a large extent. The prior art includes using polarization to attenuate ambient light, increasing the absorption layer to absorb most of the ambient light, and using the shielding thin layer to shield the ambient light, but the attenuation of the ambient light also causes the brightness and quality of the projected light to decrease, and the viewing effect remains. not ideal

[0008] Therefore, a more subtle structure is still needed in the design of the screen structure to reduce or even eliminate the influence of ambient light on the projected light, thereby solving the influence of the ambient light on the projected image.

SUMMARY OF THE INVENTION [0010] The present application provides a front projection screen capable of reflecting image light projected in front of the screen to a viewing area and transmitting a large part of ambient light to the back of the screen, thereby functioning to attenuate ambient light.

[0011]

[0012] The present application provides a front projection screen including an imaging layer that is pressed one by one by a plurality of basic imaging units, the plurality of basic imaging units being concentric arcs; the basic imaging unit from the inner circumference to the outer The circle in turn includes a first transmissive layer for transmitting light and a reflective layer for reflecting light, and the reflective layer is disposed in a front high and a low low tilt.

[0013] In an embodiment, the front projection screen further includes a scattering layer disposed between the first transmission layer and the reflective layer for scattering light.

[0014] In an embodiment, the basic imaging unit further includes a first absorbing layer for absorbing light, and the scattering layer and the first absorbing layer are respectively disposed on both sides of the reflective layer.

[0015] In an embodiment, the front projection screen further includes a second absorption layer disposed on a side of the imaging layer facing away from the image light for absorbing light.

[0016] In an embodiment, the front projection screen further includes a second transmission layer disposed on a side of the imaging layer facing away from the image light for transmitting light.

[0017] In an embodiment, the front projection screen further includes an anti-environment light reflecting layer disposed on the imaging layer facing the image light side.

[0018] In an embodiment, the first transmission layer is made of a highly transmissive glass material.

[0019] In an embodiment, the reflective layer is a specularly reflective layer.

[0020] In an embodiment, the anti-ambient light reflecting layer is an AR film or an anti-glare film.

[0021] In an embodiment, the front projection screen is rectangular; the center of the basic imaging unit is located on a center line of the bottom edge of the front projection screen, and is located on or under the bottom edge of the front projection screen.

[0022] In an embodiment, the reflective layer has a front height and a low tilt setting, and has an acute angle with the horizontal direction. In the same radius of the center of the circle, the imaging layer, the reflective layer and the horizontal direction The angle gradually decreases from the inner ring to the outer ring.

[0023] In an embodiment, in the same basic imaging unit, the angle between the reflective layer and the horizontal direction gradually increases from the center line of the bottom edge of the front projection screen to the sides of the front projection screen.

[0024] [0025] The front projection screen provided by the present application has a reflective layer in a basic imaging unit with a front high and a low tilt, which can reflect the image light projected from the front of the screen to the viewing area and avoid most of the ambient light reflection. To the viewing area, most of the ambient light can only be transmitted to the back of the screen through the first transmission layer, thereby effectively preventing the ambient light from being reflected to the viewing area, thereby reducing the ambient light and improving the viewing effect.

BRIEF DESCRIPTION OF THE DRAWINGS

1 is a schematic diagram showing a positional relationship between a front projection screen and projected image light and ambient light;

2 is a schematic plan view showing a front projection screen in an embodiment of the present application;

3 is a cross-sectional view of an imaging layer on a midline of a bottom edge and a schematic view of reflected image light of an imaging layer in an embodiment of the present application; [0029] FIG.

4 is a cross-sectional view of an imaging layer on a bottom line center line and a schematic view of an imaging layer transmitting ambient light in an embodiment of the present application; [0030] FIG.

[0031] FIG. 5 is a schematic diagram of a path of image light and ambient light incident on the reflective layer 203 in an embodiment of the present application.

DETAILED DESCRIPTION

[0033] Referring to FIG. 1, for the front projection screen, the projector for projecting image light is usually placed at a position that is downward in front of the front projection screen. In the process of projection, the ambient light that affects the image is usually located in front of the front projection screen (such as the light) and on both sides (such as the sun through the window). The application utilizes the positional relationship between the projected image light and the ambient light, and provides a front projection screen, which can effectively prevent the ambient light from being reflected to the viewing area, thereby reducing the ambient light and improving the viewing effect.

[0034] The following further describes the present invention in conjunction with the drawings and specific embodiments.

[0035]

2 to FIG. 4, the present embodiment provides a front projection screen, an imaging layer 10 which is formed by pressing a plurality of basic imaging units 20 one by one, and a plurality of basic imaging units are concentric arcs; The unit 20 includes, in order from the inner ring to the outer ring, a first transmissive layer 201 for transmitting light and a reflective layer 203 for reflecting light, and the reflective layer 203 is disposed at a front high and a low low.

[0037] In this embodiment, a rectangular front projection screen is taken as an example for description. In other embodiments, the shape of the front projection screen may be appropriately changed according to actual needs. And the reflective layer 203 has a front height and a low tilt setting. Previously, the projection screen was placed perpendicular to the ground (for example, hanging on a wall). The side facing the viewing area was the front, and the side facing away from the viewing area was the rear; in the same diameter direction, the height near the center of the circle was low, away from the center of the circle.

[0038] The center of the basic imaging unit 20 is located on the center line of the bottom edge of the front projection screen and is located on or under the bottom edge of the front projection screen. The bottom edge of the front projection screen refers to a side of the front projection screen that is placed perpendicular to the ground (for example, hanging on a wall), and the front and back of the screen mentioned in this embodiment respectively refer to the placement. The front projection screen faces the side of the image light and the side that faces away from the image light. In other embodiments, the center of the basic imaging unit 20 may also be disposed at a position offset from the centerline of the bottom edge of the front projection screen, or may be disposed at a position above the bottom edge of the front projection screen. Of course, considering the symmetry of the front projection screen and the placement of the projector in most cases of use, the center is usually placed on the center line of the bottom edge of the front projection screen and on or under the bottom edge of the front projection screen. .

[0039] The first transmission layer 201 is made of a highly transmissive glass material to facilitate transmission of image light and ambient light. The reflective layer 203 is a specularly reflective layer.

[0040]

Please refer to FIG. 3, which is a cross-sectional view of the imaging layer 10 on the midline of the bottom side and a schematic diagram of the image light reflected by the imaging layer 10. The reflective layer 203 has a front height and a low tilt setting, and has an acute angle with the horizontal direction 401. The projector located at a lower position in front of the front projection screen projects image light onto the screen, and the image light is first transmitted through the first transmission layer 201 to the reflection surface of the reflection layer 203, and the reflection layer 203 reflects the image light to the viewing area. The area indicated by the arrow in Fig. 3 is the viewing area.

[0042] Referring to FIG. 4, the ambient light 302, 303 located at the upper position in front of the front projection screen and on both sides of the screen can only be transmitted through the first transmission layer 201 to the back of the screen or the back of the reflective layer 203 (with The opposite side of the surface of the transmission layer 201 is not reflected to the viewing area in front of the front projection screen. Since the imaging layer 10 is formed by pressing a plurality of basic imaging units 20 one by one, the first transmission layer 201 transmits the ambient light 302, 303 to the back surface of the reflective layer 203, which means that the ambient light 302, 303 is transmitted to its previous basic The back side of the reflective layer 203 of the imaging unit.

[0043] Please refer to FIG. 5, which is a schematic diagram of a path of image light and ambient light incident on the reflective layer 203. The broken line 505 is the normal to the reflecting surface of the reflective layer 203. Most of the image light 503 is incident from the underside of the normal 505, and therefore, the image light 503 can be reflected to the viewing area. The direction of ambient light incidence can be divided into two, ambient light 501 from the opposite The back side of the shot layer 203 is incident on the upper side of the normal line 505, so that the ambient light 501 is not reflected to the viewing area; the ambient light 502 is incident on the front side of the reflective layer 203, but is located above the normal 505.

Therefore, ambient light 502 is also not reflected to the viewing area.

[0044] It should be noted that, in actual conditions, ambient light exists in any incident direction, and the embodiment is intended to solve the position (such as light) and the two-side positions (for example, the ambient light is mainly located in front of the front projection screen). The sun shining through the window) 吋, the effect of ambient light on the projection. For weak ambient light in other incident directions, the effect can be ignored.

Therefore, the front projection screen provided by the embodiment can effectively prevent the ambient light from being reflected to the viewing area through the structure of the imaging layer 10, thereby reducing the ambient light and improving the viewing effect.

[0046]

[0047] In order to increase the sharpness of the picture and increase the view angle of the front projection screen, the front projection screen further includes a scattering layer 202 disposed between the first transmission layer 201 and the reflective layer 203 for scattering light. The scattering layer 202 contains a plurality of minute scattering particles for scattering the image light reflected by the reflective layer 203 to the viewing area. Of course, in the process of incident on the reflective layer 203, the image light first passes through the scattering layer 202, is scattered by the scattering layer 202, and is incident on the reflective surface of the reflective layer 203.

[0048] Since part of the ambient light is incident on the back surface of the reflective layer 203, in order to prevent the ambient light from affecting the image light after being reflected by the back surface of the reflective layer 203, a first surface for absorbing light is disposed on the back surface of the reflective layer 203. Absorbing layer 204. The scattering layer 202 and the first absorption layer 204 are disposed on both sides of the reflective layer 203, respectively. In the present embodiment, the first absorbing layer 204 is made of an absorbing material having a good absorption property to absorb ambient light incident on the back surface of the reflecting layer 203.

[0049] In this embodiment, the front projection screen further includes a second absorption layer 30 disposed on the side of the imaging layer 10 facing away from the image light for absorbing light, and adopting an absorption material with better absorption performance for absorbing the front projection. The front of the screen is transmitted through the first transmission layer 201 to the ambient light behind the front projection screen to prevent ambient light from being projected behind the front projection screen and reflected back to the front of the front projection screen, thereby affecting the projected image light.

[0050] In another embodiment, the front projection screen further includes a second transmissive layer 40 disposed on a side of the imaging layer 10 facing away from the image light for use in an environment that is transmitted from the front of the front projection screen through the first transmissive layer 201. Light is transmitted to the back of the front projection screen. The second transmission layer 40 has high transmittance, and can prevent ambient light from being projected behind the front projection screen and reflected back to the front of the front projection screen, thereby affecting the projected image light. [0051] Further, the front projection screen further includes an anti-ambient light reflecting layer 50 disposed on the imaging layer 10 facing the image light side, and the anti-ambient light reflecting layer 50 may be an AR film or an anti-glare film. The anti-ambient light reflecting layer 50 can reduce the reflection of the ambient light on the front projection screen surface, preventing the occurrence of visual blurring areas or bright spots, so that the ambient light can be transmitted to the back of the front projection screen, thereby further reducing the effect of the ambient light and improving the viewing effect.

[0052]

[0053] Since the projector for projecting image light can be regarded as a point light source, and the front projection screen has a certain height, in order to better reflect the image light to the viewing area, the imaging layer is on the same radius 102 passing through the center of the circle. In 10, the angle A between the reflective layer 203 and the horizontal direction gradually decreases from the inner ring to the outer ring. As shown in Fig. 2, the angle between the reflection layer 203 in the point PI (Q1) and the horizontal direction is larger than the angle between the reflection layer 203 in the point P2 (Q2) and the horizontal direction. In this case, the image light projected from the position of the front side of the front projection screen can be reflected to the same area. As shown in FIG. 4, the reflected image lights are parallel to each other and can reach the viewing area in a concentrated manner. Guaranteed viewing.

[0054] Further, in consideration of the width of the front projection screen, in order to ensure that the front projection screen has a large viewing angle in the width direction, in the embodiment, in the same basic imaging unit 20, the center line 101 of the bottom edge of the front projection screen is projected. On both sides of the front projection screen, the angle A between the reflective layer 203 and the horizontal direction gradually increases. As shown in Fig. 2, the angle between the reflection layer 203 in the point PI (P2) and the horizontal direction is smaller than the angle between the reflection layer 203 in the point Q1 (Q2) and the horizontal direction.

[0055] Of course, in other embodiments, the magnitude of the angle A between the reflective layer 203 and the horizontal direction and its variation may be based on actual conditions (for example, the positional relationship between the projector and the front projection screen under normal circumstances, or before consideration) The visual range of the projection screen in the up and down direction) design.

[0056]

The front projection screen provided by the embodiment of the present invention can effectively suppress the influence of ambient light on the projected image, reduce the image light projected to the non-visual area, and improve the picture quality and contrast.

The present invention has been described with reference to the specific embodiments thereof, which are merely used to help the understanding of the invention and are not intended to limit the invention. For the person skilled in the art to which the invention pertains, several simple derivations, variations or substitutions can be made in accordance with the inventive concept.

technical problem The solution to the problem is the beneficial effect of the invention

Claims

Claim

[Claim 1] A front projection screen, comprising: an imaging layer (10) pressed one by one by a plurality of basic imaging units (20), wherein the plurality of basic imaging units are concentric arcs; The basic imaging unit (20) includes, in order from the inner ring to the outer ring, a first transmission layer (201) for transmitting light and a reflection layer (203) for reflecting light, and the reflection layer (203) is high in front. Low tilt setting.

[Claim 2] The front projection screen of claim 1, further comprising a scattering layer (202) disposed between the first transmission layer (201) and the reflective layer (203) for scattering light

[Claim 3] The front projection screen according to claim 2, wherein the basic imaging unit (2)

0) further comprising a first absorbing layer (204) for absorbing light, the scattering layer (202) and the first absorbing layer (204) being disposed on opposite sides of the reflective layer (203), respectively.

[Claim 4] The front projection screen of claim 1, further comprising an imaging layer

(10) A second absorbing layer (30) for absorbing light on the side facing away from the image light.

[Claim 5] The front projection screen of claim 1, further comprising an imaging layer

(10) A second transmission layer (40) for transmitting light away from the side of the image light.

[Claim 6] The front projection screen according to claim 1, further comprising an imaging layer

(10) The anti-ambient light reflecting layer (50) on the side of the image light.

[Claim 7] The front projection screen according to claim 1, wherein the first transmission layer (201)

) Highly transmissive glass materials are used.

[Claim 8] The front projection screen according to claim 1, wherein the reflective layer (203) is a specular reflection layer.

[Claim 9] The front projection screen according to claim 6, wherein the anti-ambient light reflecting layer

(50) AR film or anti-glare film.

The front projection screen according to any one of claims 1 to 9, wherein the front projection screen is rectangular; the center of the basic imaging unit (20) is located on the center line of the bottom edge of the front projection screen. And located on or under the bottom edge of the front projection screen.

[Claim 11] The front projection screen according to claim 10, wherein the reflective layer (203) The front height is high and the low tilt is set. The horizontal direction (401) has an acute angle (A). On the same radius (102) through the center of the circle, in the imaging layer (10), the reflective layer (2 03) is The angle (A) in the horizontal direction gradually decreases from the inner ring to the outer ring.

[Claim 12] The front projection screen according to claim 11, wherein the same basic imaging unit (

In the 20), from the center line (101) at the bottom of the front projection screen to the sides of the front projection screen, the angle (A) of the reflection layer (203) with the horizontal direction gradually increases.