TWI728110B - A projection screen - Google Patents

Abstract

The present invention provides a projection screen, which comprising a screen and a surface structure arranged on the projection surface of the screen. The surface structure comprises a matrix and a transparent microstructure array and a reflective layer arranged in a matrix. The transparent microstructure comprises a light incident surface and a light reflection surface. The light incident surface has a convergence and has a preset focal length in which the width in the first direction is a preset value; the light reflecting surface is a curved surface within a focal length range of the light incident surface for adjusting the exit light in the second direction and the plane of the screen In the direction of the first direction and the second direction parallel to the screen plane and perpendicular to each other. The projection screen surface structure can adjust the exit angle range of the screen exit light so that the maximum outgoing angle of the outgoing light can be greater than its incident angle and can control the incident light of a certain angle of incidence to be reflected by the screen after a predetermined angle range the effect of gain on the screen exit light within the preset angle range.

Description

A projection screen

The present invention relates to the field of optical application technology, in particular to a projection screen.

Projection screens are used in projection systems to project projected images. The relative position of the projection screen and the projector is generally fixed. The projected light is approximately incident on the screen at a certain angle of parallel light, and the incident light is reflected by the screen. The reflected light enters the human eye, so that the viewer can see the image.

In the projection system, the position of the viewer relative to the projection screen is often fixed. People hope that the reflected light of the image displayed on the screen by the projection system is only reflected to the viewing area, and the reflected light of other invalid areas is reduced, so that the brightness of the viewing screen image can be improved.

Therefore, based on the above description, in view of this, the present invention provides a projection screen capable of adjusting the range of angles of light emitted from the screen, so as to achieve the effect of gaining the light emitted from the screen within a preset angle range.

The present invention provides a projection screen, which can adjust the angle range of the light emitted from the screen, and realizes the effect of gaining the light emitted from the screen within a preset angle range.

In order to achieve the above objective, the present invention provides a projection screen, including a screen body, and a surface structure arranged on the projection surface of the screen body; the surface structure includes a matrix-arranged transparent microstructure array and a reflective layer, wherein the transparent The microstructure includes: a light incident surface that has a condensing effect on incident light and has a preset focal length, the width of the light incident surface along the first direction is a preset value, and the light incident surface is used to adjust the output light in the first direction and The direction in the plane formed by the screen normal is such that the maximum exit angle of the emitted light in the plane formed by the first direction and the screen normal is greater than that of the incident light in the plane formed by the first direction and the screen normal Incident angle; a curved light reflecting surface located within the focal range of the light incident surface, the reflecting layer is arranged on the light reflecting surface, and the light reflecting surface is used to adjust the emitted light in the second direction and the normal line of the screen. The direction in the formed plane is such that the maximum exit angle of the emitted light in the plane formed by the second direction and the screen normal is greater than the incident angle of the incident light in the plane formed by the second direction and the screen normal; the The first direction and the second direction are parallel to the screen plane and perpendicular to each other.

Optionally, the focal length of the light incident surface is less than twice the distance from the light incident surface to the light reflecting surface.

Optionally, in the plane formed by the second direction and the screen normal, the light reflecting mask has a focal point, and the focal point is located in the transparent microstructure.

Optionally, the light incident surface is a cylindrical surface or a parabolic surface with a main axis parallel to the second direction.

Optionally, the light reflection surface is a cylindrical surface or a parabolic surface with a main axis parallel to the first direction.

Optionally, the central axis of symmetry of the cylindrical surface or the parabolic cylinder as the light incident surface is not parallel to the screen normal.

Optionally, the central axis of symmetry of the cylindrical surface or the parabolic surface as the light reflecting surface is not parallel to the normal line of the screen.

Optionally, the light incident surface is a spherical or parabolic surface that has a convergent effect on the incident light and has the preset focal length.

Optionally, the light reflecting surface is a spherical surface or a parabolic surface.

Optionally, the central axis of symmetry of the spherical or parabolic surface as the light incident surface is not parallel to the screen normal.

Optionally, the central axis of symmetry of the spherical or parabolic surface as the light reflecting surface is not parallel to the normal line of the screen.

Optionally, the transparent microstructure further includes a side surface connecting the light incident surface and the light reflecting surface, and the refracted light formed by the incident light with a preset incident angle entering through the end of the light incident surface and the side surface Parallel, the side surface is provided with a light absorber.

-

時，

當tan α

-

時，

當tan θ

-tan α時，

當tan θ

-tan α時，

其中，f為該透明微結構的光入射面的焦距，d為光入射面沿第一方向的寬度，h為光入射面到光反射面的距離，α為入射光在第一平面的入射角，θ為側面與螢幕法線的夾角，γ為入射光對應的出射光在第一平面的最大的第一出射角，β為入射光對應的出射光在第一平面的最大的第二出射角，第一出射角對應的出射光與第二出射角對應的出射光分別位於螢幕法線的兩側。 Optionally, for a transparent microstructure in the transparent microstructure array, there is a first plane passing through the transparent microstructure and parallel to the first direction and the normal line of the screen at the same time, and the transparent microstructure is along the first plane. The cross section satisfies the following relationship: when tan α

-

Time,

When tan α

-

Time,

When tan θ

-tan α,

When tan θ

-tan α,

Where f is the focal length of the light incident surface of the transparent microstructure, d is the width of the light incident surface in the first direction, h is the distance from the light incident surface to the light reflecting surface, and α is the incident angle of the incident light on the first plane , Θ is the angle between the side surface and the screen normal, γ is the largest first exit angle of the emitted light corresponding to the incident light in the first plane, β is the largest second exit angle of the exit light corresponding to the incident light in the first plane , The exit light corresponding to the first exit angle and the exit light corresponding to the second exit angle are respectively located on both sides of the normal line of the screen.

Optionally, the light absorber is filled between adjacent sides of the transparent microstructure.

Optionally, the surface structure at least includes a first area and a second area; the main optical axis of the light incident surface of the transparent microstructure in the first area is different from the light incident surface of the transparent microstructure in the second area. The main optical axis is not parallel.

It can be seen from the above content that, compared with the prior art, the projection screen provided by the present invention includes a screen body and a surface structure arranged on the projection surface of the screen body. The surface structure includes a matrix-arranged transparent microstructure array and a reflective surface. Floor. Among them, the transparent microstructure includes a light incident surface and a light reflecting surface. The light incident surface has a convergent effect on the incident light and has a preset focal length; the light reflecting surface is curved and located within the focal length range of the light incident surface, and the light reflecting surface is provided with The reflective layer makes it reflect light.

When the projected light is irradiated to the projection screen at a certain angle of incidence, the incident light is refracted by the light incident surface and enters the transparent microstructure. The resulting refracted light is condensed and irradiated on the light reflecting surface before the focal plane. After being reflected, the light beam is again It is refracted by the light incident surface to form outgoing light. The reverse extension line forms an image of a point light source in the transparent microstructure, and the emitted light is equivalent to the light emitted from the point light source. Adjust the direction of the emitted light in the plane formed by the first direction and the screen normal through the light incident surface, adjust the focal length of the designed light incident surface and the width along the first direction, and the thickness of the transparent microstructure (that is, the light incident surface and the light The distance of the reflective surface) can control the position of the point light source image formed by the transparent microstructure, and then adjust the exit angle range of the emitted light in the plane formed by the first direction and the normal line of the screen. The light reflecting surface is used to adjust the direction of the emitted light in the plane formed by the second direction and the screen normal, so that the maximum exit angle of the emitted light in the plane formed by the second direction and the screen normal is greater than that of the incident light in the second direction. The angle of incidence in the plane formed by the direction and the screen normal.

In practical applications, according to the incident angle of the incident light reaching the projection screen and the required exit angle range of the light emitted from the screen, the focal length and width of the light incident surface of the transparent microstructure and the thickness of the transparent microstructure can be controlled accordingly by designing the focal length and width of the light incident surface of the transparent microstructure. The incident light with a certain incident angle is emitted within a preset angle range, so as to achieve the effect of gaining the light emitted from the screen within the preset angle range, and achieve the effect of improving the light utilization rate. If the output angle range of the light emitted from the screen corresponds to the viewing area, the light emitted from the projection screen can be limited to the viewing area, which can achieve the effect of gaining the output light corresponding to the viewing area, and can improve the viewer's viewing of the screen image The brightness.

<The present invention>

α: incident angle

β: The largest second exit angle

γ: The largest first exit angle

d: width

f: the focal length of the light incident surface of the transparent microstructure

f’: Focal length of the light reflecting surface

h: distance

100: Transparent microstructure

101: Light incident surface

102: light reflecting surface

103: reflective layer

104: side

105: light absorber

106: focal plane

107: Projection screen

108: Projector

109: Screen Normal

110: Symmetrical Axis

1 is a schematic diagram of the light path of a transparent microstructure of a projection screen provided by an embodiment of the present invention; FIG. 2 is a schematic diagram of the vertical angle range after the projection screen is suspended; FIG. 3 is a schematic diagram of the horizontal angle range after the projection screen is suspended; Is a schematic diagram of a surface structure of a projection screen provided by an embodiment of the present invention; 5A is a cross-sectional view of the transparent microstructure in an embodiment of the present invention along the first direction and the plane formed by the screen normal; FIG. 5B is a cross-sectional view of the transparent microstructure shown in FIG. 5A along the second direction and the plane formed by the screen normal Figure 6A is a cross-sectional view of the transparent microstructure along the first direction and the plane formed by the screen normal in another embodiment of the present invention; Figure 6B is a schematic diagram of the optical path of the transparent microstructure shown in Figure 6A; Figure 7 is another embodiment of the present invention A cross-sectional view of a plane formed by the transparent microstructure along the second direction and the normal line of the screen in an embodiment; FIG. 8 is a schematic diagram of a surface structure of a projection screen according to another embodiment of the present invention.

In order to more clearly describe the projection screen proposed by the present invention, the preferred embodiments of the present invention will be described in detail below in conjunction with the drawings.

The present invention provides a projection screen, which can adjust the angle range of the light emitted from the screen, and realizes the effect of gaining the light emitted from the screen within a preset angle range.

The projection screen provided by the present invention includes a screen body and a surface structure arranged on the projection surface of the screen body; the surface structure includes a transparent microstructure array arranged in a matrix and a reflective layer, wherein the transparent microstructure includes: light The incident surface, the light incident surface has a convergent effect on the incident light, and has a preset focal length, the width of the light incident surface along the first direction is a preset value, and the light incident surface uses its refraction function to adjust the emitted light in the first direction and the screen The direction in the plane formed by the normal, so that the maximum output of the emitted light in the plane formed by the first direction and the screen normal The angle is greater than the incident angle of the incident light in the plane formed by the first direction and the normal line of the screen; the light reflecting surface, the light reflecting surface is located within the focal length range of the light incident surface, and is curved, and the light reflecting surface is provided with The reflective layer, the light reflecting surface uses its reflection function to adjust the direction of the emitted light in the plane formed by the second direction and the screen normal, so that the maximum emission of the emitted light in the plane formed by the second direction and the screen normal The angle is greater than the incident angle of the incident light in the plane formed by the second direction and the normal line of the screen; the above-mentioned first direction and the second direction are both parallel to the plane of the screen and both are perpendicular to each other.

It can be seen from the above content that the projection screen provided by the present invention includes a screen body and a surface structure arranged on the projection surface of the screen body. The surface structure includes a matrix-arranged transparent microstructure array and a reflective layer. Among them, the transparent microstructure includes a light incident surface and a light reflecting surface. The light incident surface has a convergent effect on the incident light and has a preset focal length; the light reflecting surface is curved and located within the focal length range of the light incident surface, and the light reflecting surface is provided with The reflective layer makes it reflect light.

In the present invention, the transparent microstructure is a transparent medium with a refractive index greater than 1, which may be organic components such as resins, or inorganic components such as glass and quartz.

In the present invention, the described exit angle refers to the angle between the emitted light and the normal line of the screen, and the direction of the light in a certain plane is the direction of the projection of the beam of light on the plane.

When the projected light is irradiated to the projection screen at a certain angle of incidence, the incident light is refracted by the light incident surface and enters the transparent microstructure. The resulting refracted light is condensed and irradiated on the light reflecting surface before the focal plane. After being reflected, the light beam is again It is refracted and emitted by the light incident surface to form outgoing light, and the reverse extension line of the outgoing light forms an image of a point light source in the transparent microstructure, and the outgoing light is equivalent to the light emitted by the point light source. Through the light incident surface, the direction of the emitted light in the plane formed by the first direction and the screen normal can be adjusted, so that the maximum exit angle of the emitted light in the plane formed by the first direction and the screen normal can be greater than that of the incident light. The entrance in the plane formed by the first direction and the screen normal The angle of incidence, by adjusting the focal length and width along the first direction of the designed light incident surface, and the thickness of the transparent microstructure (that is, the distance between the light incident surface and the light reflecting surface), the position of the point light source image formed by the transparent microstructure can be controlled, and then To adjust the angle range of the emitted light in the plane formed by the first direction and the screen normal. The light reflecting surface is used to adjust the direction of the emitted light in the plane formed by the second direction and the screen normal, so that the maximum exit angle of the emitted light in the plane formed by the second direction and the screen normal is greater than that of the incident light. The incident angle in the plane formed by the second direction and the screen normal.

In practical applications, according to the incident angle of the incident light reaching the projection screen and the required exit angle range of the light emitted from the screen, the focal length and width of the light incident surface of the transparent microstructure and the thickness of the transparent microstructure can be controlled accordingly by designing the focal length and width of the light incident surface of the transparent microstructure. The incident light with a certain incident angle is emitted within a preset angle range, so as to achieve the effect of gaining the light emitted from the screen within the preset angle range. If the output angle range of the light emitted from the screen corresponds to the viewing area, the light emitted from the projection screen can be limited to the viewing area, which can achieve the effect of gaining the output light corresponding to the viewing area, and can improve the viewer's viewing of the screen image The brightness.

In the present invention, the light reflecting surface is required to be within the focal length range of the light incident surface, that is, the distance between the light incident surface and the light reflecting surface is required to be smaller than the focal length of the light incident surface. First, it is required that the light reflecting surface cannot be located on the focal plane of the light incident surface: if the light reflecting surface is on the focal plane, the incident light will converge on a point on the light reflecting surface. Consider the simplest case where the incident light is incident along the normal line of the screen (incidence angle is 0°), then after the light is reflected by the light reflecting surface, it exits through the light incident surface, and the emitted light still exits in parallel along the normal direction of the screen without any change at all. The angle of light. Secondly, if the distance between the light reflecting surface and the light incident surface is greater than the focal length of the light incident surface, then in the transparent microstructure, the light will converge before reaching the light reflecting surface, and the condensed light will be incident on the light reflecting surface in the form of divergent light. After being reflected, it diverges further, making it impossible for a lot of light to reach the light incident surface; and in this case, it means either The curvature of the light incident surface is large (difficult to process, difficult to design, and easy to deviate from the paraxial optics category), or the distance from the light incident surface to the light reflecting surface is large (meaning the screen is thickened). The present invention sets the light reflecting surface within the focal length range of the light incident surface, and aims to realize such a model—the object distance of the point light source is smaller than the focal length of the convex lens, so that there is an image of a point light source, and the light is equivalent to the image from the point light source. Issued must be divergent.

The above is the core idea of the present invention. In order to make the above objectives, features and advantages of the present invention more obvious and understandable, the principles and specific implementations of the present invention will be described in detail below with reference to the accompanying drawings.

In the following description, many specific details are set forth in order to fully understand the present invention, but the present invention can also be implemented in other ways different from those described here, and those skilled in the art can do so without departing from the connotation of the present invention. Similar promotion, therefore, the present invention is not limited by the specific embodiments disclosed below.

Secondly, the present invention will be described in detail in combination with schematic diagrams. When describing the embodiments of the present invention in detail, the cross-sectional view showing the structure will not be partially enlarged according to the general scale, and the schematic diagram is only an example, which should not limit the present invention. The scope of invention protection. In addition, the three-dimensional dimensions of length, width and depth should be included in the actual production.

In the following, the principle of adjusting the output angle range of the emitted light by the projection screen of the present invention will be described in detail with reference to a schematic diagram of the transparent microstructure in the embodiment of the present invention.

For a transparent microstructure in the transparent microstructure array of the present invention, there is a plane passing through the transparent microstructure and parallel to the first direction and the screen normal. Please refer to FIG. 1, which is an embodiment of the present invention. A schematic diagram of the light path of a transparent microstructure of a projection screen. As shown in FIG. 1, the transparent microstructure includes a light incident surface 101 and a light reflecting surface 102, wherein the light incident surface 101 The focal length f of the light incident surface with a transparent microstructure has a width d, and the distance h from the light reflecting surface 102 to the focal plane 106.

Assume that the incident angle of the incident light in the first plane formed by the first direction and the screen normal 109 is α (the incident angle refers to the angle between the incident light and the projection screen normal, and the incident angle of the incident light in the first plane refers to the angle between the incident light and the normal line of the projection screen. The angle between the projection of the incident light beam in the first plane and the normal line of the screen). In the first plane, the emitted light formed after the incident light passes through the transparent microstructure includes the first emitted light located on both sides of the normal line of the screen. Compared with the second exit light, the first exit light corresponds to the first exit angle, the second exit light corresponds to the second exit angle, and the exit angle range of the screen exit light corresponds to the largest first exit angle γ and the largest second exit angle. The angle range between the exit angles β, so the largest first exit angle γ and the largest second exit angle β describe the exit angle range of the exit light of the projection screen.

Based on the optical reflection theory, according to the incident angle α of the incident light, by correspondingly designing the focal length f of the light incident surface of the transparent microstructure, the width d of the light incident surface, and the distance h from the light reflecting surface to the focal plane 106 of the light incident surface, The range of the first exit angle and the second exit angle of the light emitted by the projection screen is controlled, so as to control and adjust the exit angle range of the light formed by the projection screen in the first plane formed by the first direction and the screen normal 109.

Please refer to FIG. 2, which is a schematic diagram of the vertical angle range of the projection screen after it is hung. As shown in Figure 2, in practical applications, the first direction may be the vertical direction after the projection screen is suspended. Within the vertical range after the projection screen 107 is suspended, the light emitted from the screen has a certain angular range corresponding to the viewing area. The surface structure of the projection screen 107 can control the emission angle range of the light emitted from the screen in the vertical range, so that the light emitted from the screen in the vertical range of the screen corresponds to the viewing area.

Please continue to refer to Figure 3, which is a schematic diagram of the angular range of the horizontal direction after the projection screen is hung. As shown in Figure 3, the first direction can also be the horizontal direction after the projection screen is hung. Through the surface structure of the projection screen, it is possible to control the emission angle range of the light emitted from the screen within the level range, so that the light emitted from the screen within the level range corresponds to the viewing area.

出射光角度過大、難以控制角度範圍；

在該點光源的實像位置附近，灰塵等空氣中的顆粒物可能會對該集中的光線造成極大的影響，嚴重影響觀影體驗。 In a specific embodiment of the present invention, referring to FIG. 1, the focal length of the light incident surface 101 is less than twice the distance from the light incident surface 101 to the light reflecting surface 102, so as to ensure that the refracted light is formed by the light reflecting surface 102. The focal length f of the light incident surface of the transparent microstructure, the image of the point light source must also be in the transparent microstructure (that is, the inside of the screen), which is a virtual image, which can be controlled by the positional relationship between the virtual image of the point light source and the edge of the light incident surface The angular range of the emitted light in the first direction. If the focal length of the light incident surface 101 is greater than twice the distance between the light incident surface 101 and the light reflecting surface 102, it will inevitably cause the emitted light to form a real image of a point light source between the screen and the audience.

The angle of the emitted light is too large and it is difficult to control the angle range;

Near the real image position of the point light source, airborne particles such as dust may have a great impact on the concentrated light and seriously affect the viewing experience.

The projection screen of the present invention is provided with a matrix-arranged transparent microstructure array on the projection surface. Based on the transparent microstructure, the light incident surface and the light reflecting surface are designed with specific dimensions, and the light emitted from the screen can be adjusted in the first direction and the normal line of the screen. A range of exit angles in the plane is formed, and the exit range of the light emitted from the screen in the second plane formed by the second direction and the normal line of the screen is ensured, so as to achieve the effect of gaining the light emitted from the screen within the preset angle range. If the output angle range corresponds to the viewing area, the effect of gaining the output light corresponding to the viewing area is realized, and the brightness of the screen image viewed by the viewer can be improved.

Several specific embodiments of the projection screen of the present invention will be described in detail below with reference to the accompanying drawings.

Please refer to FIG. 4, which is a schematic diagram of a surface structure of a projection screen according to an embodiment of the present invention. As shown in FIG. 4, in a specific embodiment of the projection screen of the present invention, The surface structure includes an array of transparent microstructures 100 arranged in a matrix and a reflective layer 103, wherein the transparent microstructure 100 includes a light incident surface 101 and a light reflecting surface 102.

The light incident surface 101 is a cylindrical surface whose main axis is parallel to the second direction and has a condensing effect on incident light. The focal length f of the light incident surface with a preset transparent microstructure is the width d along the first direction. The light reflecting surface 102 is located within the focal length range of the light incident surface 101, and the light reflecting surface 102 is curved and is provided with a reflecting layer 103. The main axis of the cylindrical surface is the axis of the cylinder corresponding to the cylindrical surface, that is, the line parallel to the cylindrical surface. The focal length f of the light incident surface of the transparent microstructure here is considered to be the focal length of the arc on the cylindrical surface under paraxial optics, and is not limited to the focal point as a "point" in the strict sense.

In another embodiment of the present invention, the light incident surface 101 can also be replaced with a parabolic cylinder whose main axis is parallel to the second direction, and the main axis of the parabolic cylinder is a line parallel to the parabolic cylinder.

When the incident light is refracted by the cylindrical or parabolic light incident surface 101 into the transparent microstructure, it is focused and reflected and then refracted again by the light incident surface 101 to form the emergent light, and the reverse extension of the formed emergent light is in the transparent The microstructure converges into a virtual image of a point light source. The emitted light can be regarded as the light emitted by the point light source through the light incident surface. Therefore, by adjusting the focal length of the light incident surface and the width along the first direction, the transparent microstructure The thickness can adjust the emission angle range of the light emitted from the screen in the first plane formed by the first direction and the normal line 109 of the screen.

The curved light reflecting surface 102 can expand the range of the exit angle of the exiting light in the second plane formed by the second direction and the normal line 109 of the screen.

Please continue to refer to FIGS. 5A and 5B, in which, FIG. 5A is a cross-sectional view of the transparent microstructure along the first direction and the screen normal in an embodiment of the present invention. The FIG. 5B is the transparent microstructure shown in FIG. 5A along the plane. A cross-sectional view of the plane formed by the second direction and the screen normal. As shown in the figure, in a structural design of the transparent microstructure of this embodiment, the light reflecting surface 102 is a circle whose main axis is parallel to the first direction. The cylindrical surface, or the light reflecting surface 102 may also be a parabolic cylindrical surface whose main axis is parallel to the first direction. The focal point of the light reflecting surface 102 is located in the transparent microstructure, so that in the plane formed by the second direction and the screen normal, the refracted light is converged and refracted again by the light incident surface 101. The maximum exit angle of the formed light is greater than The incident angle guarantees the scope of the exit angle of the second plane formed by the second direction and the screen normal 109.

In practical applications, according to the incident angle of the projected light to the projection screen, the focal length f of the light incident surface of the transparent microstructure is correspondingly designed, the width d of the light incident surface along the first direction, and the focal plane 106 from the light reflecting surface to the light incident surface. The distance h of the light reflecting surface and the focal length f'of the light reflecting surface can be controlled to adjust the angle range of the light emitted from the screen in the first plane formed by the first direction and the screen normal 108, while ensuring that the light emitted from the screen is in the second direction and The exit angle range in the second plane formed by the screen normal 109, realizes that the incident light with a certain incident angle is reflected by the screen and then exits within the preset angle range, which achieves the effect of gaining the screen's emergent light within the preset angle range .

In the above embodiment, the transparent microstructure is a symmetrical design, that is, the central axis of symmetry of the cylindrical or parabolic light incident surface 101 is parallel to the screen normal, and the cylindrical or parabolic light reflecting surface 102 The axis of symmetry is parallel to the screen normal. This structure design, as shown in Figure 1, because the incident light is obliquely incident, that is, has a certain angle of incidence, so in the first plane formed by the first direction and the screen normal 109, the incident light is transparent through the projection screen. The angle range of the emergence angle γ of the first emergent light on the normal side of the screen formed by the emergent light formed after the structure is always greater than the angle range of the emergence angle β of the second emergent light on the other side of the screen normal. However, in practical applications, sometimes the range of the maximum second exit angle β is required to be greater than the range of the maximum first exit angle γ. Based on this, in another specific embodiment of the projection screen of the present invention, in order to more flexibly adapt to the requirements of the output angle range, the transparent microstructure may adopt an asymmetrical design.

Please continue to refer to FIG. 6A. FIG. 6A is a cross-sectional view of a plane formed by the transparent microstructure along the first direction and the normal line of the screen in another embodiment of the present invention. As shown in FIG. 6A, specifically, the central axis of symmetry 110 of the cylindrical or parabolic surface as the light incident surface 101 is not parallel to the screen normal 109; or, refer to FIG. 7, which is another embodiment of the present invention A cross-sectional view of the plane formed by the transparent microstructure along the second direction and the normal line of the screen. As shown in FIG. 7, the central axis of symmetry 110 of the cylindrical or parabolic surface as the light reflecting surface 102 is not parallel to the normal line 109 of the screen. Alternatively, the central axis of symmetry 110 of the cylindrical or parabolic surface as the light incident surface 101 is not parallel to the screen normal 109, and the central axis of symmetry 110 of the cylindrical or parabolic surface as the light reflecting surface 102 is not parallel to the screen normal 109 .

Please refer to FIG. 6B. FIG. 6B is a schematic diagram of the optical path of the transparent microstructure shown in FIG. 6A. As shown in FIG. 6B, the center axis of symmetry 110 of the cylindrical or parabolic surface as the light incident surface 101 is not parallel to the screen normal 109 The embodiment is a schematic diagram of the light path in a plane passing through the transparent microstructure and parallel to the first direction and the normal line 109 of the screen. The central axis 110 of symmetry of the light incident surface 101 is not parallel to the screen normal 109 and has a certain included angle. In the first plane formed by the first direction and the screen normal, the focal position of the light incident surface will move accordingly, correspondingly, The position of the image of the point light source formed by the reverse extension of the emergent light is also moved accordingly. Therefore, by adjusting the angle between the symmetrical central axis 110 of the light incident surface 101 and the screen normal 109, the image and light of the point light source are changed. The positional relationship of the incident surface can flexibly control the angle range of the formed first and second emergent light. For example, it can be realized that the range of the maximum second emergence angle β is greater than the angular range of the maximum first emergence angle γ.

For the embodiment where the central axis of symmetry 110 of the cylindrical or parabolic surface as the light reflecting surface 102 is not parallel to the screen normal 109, the light reflecting surface is adjusted in the second plane formed by the second direction and the screen normal 109 The angle between the symmetrical axis 110 of 102 and the normal line 109 of the screen changes the light reflection The position of the focal point of the emitting surface in the transparent microstructure can control and adjust the divergence angle range of the emitted light in the second plane formed by the second direction and the screen normal 109.

The central axis of symmetry 110 of the cylindrical or parabolic surface as the light incident surface 101 is not parallel to the normal line 109 of the screen, and the central axis of symmetry 110 of the cylindrical or parabolic surface as the light reflecting surface 102 is not parallel to the normal line 109 of the screen. In an embodiment, by changing the angle between the central axis 110 of symmetry of the light incident surface 101 and the screen normal 109, the positional relationship between the image of the point light source and the light incident surface can be changed to control the angles of the first and second emergent lights formed At the same time, by adjusting the angle between the symmetry axis 110 of the light reflecting surface 102 and the screen normal 109, the focal position of the light reflecting surface can be changed, and the second plane formed by the second direction of the emitted light and the screen normal 109 can be adjusted accordingly The range of exit angles within.

Further, in another specific embodiment of the present invention, the angle between the central axis of symmetry 110 and the incident light direction is smaller than the angle between the screen normal 109 and the incident light direction. This technical solution can make the exit angle of the emitted light follow the screen normal 109 The two directions on both sides are more evenly distributed.

It is better understood here that the central axis of symmetry 110 of the cylindrical surface is the line that bisects the arc of the cylindrical surface in the plane and passes through the center in the plane perpendicular to the main axis of the cylindrical surface; and the symmetry central axis of the parabolic surface 110 is a line that passes through the vertex and focus of the parabola in the plane perpendicular to the main axis of the parabolic cylinder.

This asymmetric design facilitates more freely adjusting the emission range of the emitted light in combination with the incident angle, can expand the degree of freedom of design, and can be designed to meet the requirements of more incident angles and emission angles.

Please refer to FIG. 8, which is a schematic diagram of a surface structure of a projection screen according to another embodiment of the present invention. As shown in FIG. 8, in other specific embodiments of the projection screen of the present invention, on the basis of the above specific embodiments, the transparent microstructure further includes connecting the light incident surface 101 and the light reflecting surface. A side surface 104 of the emitting surface 102 is parallel to the refracted light formed by the incident light with a predetermined incident angle being refracted by the end of the light incident surface 101, and the side surface 104 is provided with a light absorber 105.

A transparent microstructure may have one or more curved or flat side surfaces, and there is a parallel incident light, and the refracted light formed by the parallel incident light on the side connecting the light incident surface 101 and any side surface is parallel to the side surface.

In this embodiment, the light absorber 105 is filled between the side surfaces 104 adjacent to the transparent microstructure 100.

When the stray light with other angles of incidence is irradiated into the transparent microstructure, especially the large-angle stray light, the refracted light will be deflected to the side and be absorbed by the light absorber on the side.

Therefore, the transparent microstructure has a side surface, and a light absorber is provided on the side surface, which can absorb stray light so that the stray light will not be emitted within the required output angle range. If the output angle range of the emitted light corresponds to the viewing area, the The stray light emitted to the viewing area is reduced, thereby enhancing the contrast of the screen image viewed by the viewer.

-

時，

當tan α

-

時，

當tan θ

-tan α時，

當tan θ

-tan α時，

其中，f為該透明微結構的光入射面的焦距，d為光入射面沿第一方向的寬度，h為光入射面到光反射面的距離，α為入射光在第一平面的入射角，θ 為側面與螢幕法線109的夾角，γ為入射光對應的出射光在第一平面的最大的第一出射角，β為入射光對應的出射光在第一平面的最大的第二出射角，第一出射角對應的出射光與第二出射角對應的出射光分別位於螢幕法線109的兩側。 For a transparent microstructure in the transparent microstructure array of this embodiment, on a first plane passing through the transparent microstructure and parallel to the first direction and the screen normal 109, according to the optical reflection theory, along the first plane The cross-section of the plane satisfies the following relationship, when tan α

-

Time,

When tan α

-

Time,

When tan θ

-tan α,

When tan θ

-tan α,

Where f is the focal length of the light incident surface of the transparent microstructure, d is the width of the light incident surface in the first direction, h is the distance from the light incident surface to the light reflecting surface, and α is the incident angle of the incident light on the first plane , Θ is the angle between the side surface and the screen normal 109, γ is the largest first exit angle of the emitted light corresponding to the incident light in the first plane, β is the largest second exit angle of the emitted light corresponding to the incident light in the first plane The output light corresponding to the first output angle and the output light corresponding to the second output angle are respectively located on both sides of the normal line 109 of the screen.

Therefore, by designing the focal length f of the light incident surface of the transparent microstructure, the width d of the light incident surface along the first direction, the distance h from the light reflecting surface to the focal plane 106, and the angle θ between the side surface and the screen normal 109, the screen can be controlled accordingly. The first exit angle and the second exit angle of the exit light in the second plane formed by the second direction and the screen normal 109 are used to control and adjust the exit angle range of the exit light formed by the projection screen in the second plane.

In the projection screen of the present invention, the light incident surface of the transparent microstructure can also adopt a spherical or parabolic design, so that the light incident surface can simultaneously adjust the output angle range of the first direction and the second direction. Specifically, in another specific embodiment of the projection screen of the present invention, the projection screen includes a screen body and a surface structure arranged on the projection surface of the screen body, and the surface structure includes a matrix-arranged transparent microstructure array and a reflective layer. Among them, the transparent microstructure includes a light incident surface and a light reflecting surface.

The light incident surface is a spherical or parabolic surface with a preset focal length that has a convergent effect on the incident light, and its width along the first direction and the second direction is a preset value. The light reflection surface is a curved surface located within the focal length range of the light incident surface, and a reflection layer is provided on the light reflection surface. Wherein, the first direction and the second direction are parallel to the plane of the screen and perpendicular to each other. The focal point and focal length of the spherical surface of the present invention are the focal point and focal length in the sense of paraxial optics.

In any plane range parallel to the normal line of the screen, when the incident light is refracted by the light incident surface into the transparent microstructure, it is focused and reflected by the light reflecting surface and then refracted by the light incident surface again. Outgoing light, the reverse extension of the outgoing light formed is condensed into a virtual image of a point light source in the transparent microstructure. The outgoing light can be regarded as the light emitted by the point light source emitted from the light incident surface, so the virtual image of the point light source is used The positional relationship with the edge of the light incident surface controls the angle range of the emitted light in any plane parallel to the normal line of the screen. The angle range of the emitted light from the screen is adjusted by adjusting the focal length and width of the light incident surface and the thickness of the transparent microstructure.

The spherical and parabolic surfaces in this embodiment are actually the same as the cylindrical and parabolic surfaces in the above embodiments. The principle of adjusting the angle of the emitted light is the same. The difference is that the spherical and parabolic surfaces adjust the angle of emission in two directions. The surface and the parabolic cylinder only adjust the exit angle in one direction. The spherical surface and the parabola are the rotating bodies of the arc and the parabola, while the cylindrical surface and the parabola are the cylinder of the arc and the parabola. Therefore, in the present invention, the arc and parabola on any tangent surface of the sphere and parabola and other parts of the corresponding transparent microstructure can refer to the tangent surface perpendicular to the cylindrical surface in the cylindrical surface and the parabolic surface in the above embodiment. Design rules.

In an implementation of the transparent microstructure of this embodiment, the focal length of the light incident surface is less than twice the distance from the light incident surface to the light reflecting surface. The specific principle is similar to the above description, and will not be repeated here.

In a structural design of the transparent microstructure of this embodiment, the light reflecting surface is also spherical or parabolic, and the focal point of the spherical or parabolic light reflecting surface is located in the transparent microstructure. In any plane parallel to the normal line of the screen, the refracted light is converged by the reflection of the light reflecting surface, and then refracted by the light incident surface again. The maximum emergence angle of the formed emergent light will be greater than the incident angle, which expands the emergence of the light in the second direction. The divergence angle in the plane formed by the normal line of the screen ensures the emission range of the emitted light.

In this embodiment, both the light incident surface and the light reflecting surface simultaneously adjust the angle ranges of the emitted light in the first direction and the second direction that are perpendicular to each other. The adjustment of the exit light angle of the light reflecting surface in two directions is used as a supplement to the adjustment of the light incident surface, which strengthens the function of the microstructure to enlarge the exit angle. If only a spherical or parabolic light incident surface is used for adjustment, and the light reflecting surface adopts a flat reflecting surface design, the curvature of the light incident surface needs to be increased to achieve the same effect, which may lead to an optical design that does not conform to the paraxial optics The design may lead to a reduction in the area of a single microstructure on the screen and an increase in the number, which complicates the manufacture of the screen. Of course, in some application scenarios, a design scheme in which the light incident surface is a spherical or parabolic surface and the light reflecting surface is a flat surface can also be adopted; similarly, the case where the light incident surface is a cylindrical surface or a parabolic cylinder in the above embodiment is also applicable. The light-reflecting surface can be designed as a flat surface, so that the shape of the light-reflecting surface does not need to be processed when making the screen.

In practical applications, according to the incident angle of the projected light to the projection screen, the focal length of the light incident surface, the width of the light incident surface, the distance from the light reflecting surface to the focal plane of the light incident surface, and the focal length of the light reflecting surface are designed accordingly. Control the exit angle range of the light emitted from the screen, realize that the incident light with a certain incident angle is reflected by the screen and then exit at a preset angle range, so as to achieve the effect of gaining the light emitted from the screen within the preset angle range.

In the above specific embodiment, the transparent microstructure is a symmetrical design, that is, the symmetry center axis of the spherical or parabolic light incident surface is parallel to the screen normal, and the symmetry center axis of the spherical or parabolic light reflecting surface is parallel to the screen normal . The central axis of symmetry of a spherical or parabolic surface is its rotational symmetry axis. This structure design, just like the analysis in the above description, the incident light formed after the transparent microstructure of the projection screen, the first outgoing light formed on the normal side of the screen, the angle range of the first outgoing light γ is always greater than that of the screen. The angle range of the exit angle β of the second exit light on the other side of the line The adjustment of the angle range of the light emitted by the screen is limited, which cannot meet some requirements in practical applications.

To solve this problem, in another specific embodiment of the present invention, the symmetry center axis of the sphere or paraboloid as the light incident surface is not parallel to the screen normal; or the symmetry center axis of the sphere or paraboloid as the light reflecting surface is in line with the screen method. The lines are not parallel; or the symmetry center axis of the sphere or paraboloid as the light incident surface is not parallel to the screen normal, and at the same time, the symmetry center axis of the sphere or paraboloid as the light reflecting surface is not parallel to the screen normal. The use of this asymmetric design facilitates more freely adjusting the emission range of the emitted light in combination with the angle of incidence, can expand the degree of freedom of design, and can be designed to meet the requirements of more incident angles and emission angles.

Further, in an embodiment of the present invention, the angle between the central axis of symmetry and the direction of the incident light is smaller than the angle between the normal of the screen and the direction of the incident light, and this technical solution can make the distribution of the emergence angle of the emergent light more even in all directions.

In other embodiments of the projection screen of the present invention, the above-mentioned embodiments can also be combined to obtain the light incident surface as a spherical or parabolic surface that adjusts the exit angles in the first direction and the second direction, and the light reflecting surface is the adjustable first direction. The technical solution of a cylindrical surface or a parabolic cylindrical surface with two-direction light exit angles; similarly, it also includes a free combination of any one of a cylindrical surface, a parabolic cylindrical surface, a spherical surface, or a parabolic surface on the light incident surface and the light reflecting surface.

In other embodiments of the projection screen of the present invention, at least one of the light incident surface and the light reflecting surface is a free-form surface, and the shape of the free-form surface is designed according to the specific situation, which further increases the design freedom. The requirements can be designed to meet, and can be widely used in various applications.

In other specific embodiments of the projection screen of the present invention, on the basis of the above specific embodiments, the transparent microstructure further includes a side surface connecting the light incident surface and the light reflecting surface, and the side surface is opposite to the predetermined incident angle. The refracted light formed by the light incident through the end of the light incident surface is parallel, and the side surface is provided with a light absorber.

A transparent microstructure may have one or more curved or flat side surfaces, and there is a parallel incident light, and the refracted light formed by the parallel incident light on the side connecting the light incident surface and any side surface is parallel to the side surface. Wherein, the light absorber can be filled between adjacent sides of the transparent microstructure.

In this way, when the stray light whose incident angle is other angles is irradiated into the transparent microstructure, its refracted light will be deflected to the side surface and will be absorbed by the light absorber on the side surface. Therefore, the transparent microstructure has a side surface, and a light absorber is provided on the side surface, which can absorb stray light so that the stray light will not be emitted within the required output angle range. If the output angle range of the emitted light corresponds to the viewing area, the The stray light emitted to the viewing area is reduced, thereby enhancing the contrast of the screen image viewed by the viewer.

Considering the manufacturing cost and difficulty of the screen, a technical solution with the same transparent microstructure on the screen can be selected. This design can also meet certain viewing requirements. However, for projection screens, the plane area is generally relatively large, and the projector 108 is placed at a fixed position relative to the screen. Therefore, the incident light irradiated by the projector 108 on the screen surface will have different incident angles on different areas of the screen surface, relative to the viewing area. The range of exit angles is also different.

Based on this, in another specific embodiment of the projection screen of the present invention, the surface structure provided on the projection surface of the screen body includes at least a first area and a second area. The main light of the light incident surface of the transparent microstructure of the first area is Axis and the main light of the light incident surface of the transparent microstructure of the second area The axes are not parallel. Here, the main optical axis of the light incident surface passes through the focal point of the light incident surface, and the light incident along the main optical axis is not refracted.

For the first area and the second area of the projection screen, the incident light is incident at different incident angles. The size of the transparent microstructure in the first area is different from that of the transparent microstructure in the second area. The size of the transparent microstructure in the first area is different. The main optical axis of the light incident surface is not parallel to the main optical axis of the light incident surface of the transparent microstructure in the second area, so that the transparent microstructures in the first area and the second area can achieve different exit angle adjustment effects for incident light. The formed outgoing light corresponds to different outgoing ranges to meet the requirements for the outgoing angle range of the outgoing light from different areas of the projection screen.

Specifically, in the foregoing embodiment, the light incident surface is cylindrical, parabolic, spherical, or parabolic, and/or the light reflecting surface is cylindrical, parabolic, spherical, or parabolic, depending on the specific theater or projection scene. The arrangement further refines the different design of the light incident surface and/or the light reflecting surface of the first area and the second area. For example, the main optical axis and/or the central axis of symmetry of the light incident surfaces of the first region and the second region are respectively arranged in different directions.

For example, the first area may correspond to the middle area of the projection screen, and the second area may correspond to the edge area of the projection screen. According to the different incident angles of the projection light illuminating the middle area and the edge area of the screen and the corresponding required output angle range, Design the size of the transparent microstructure in different areas respectively.

It is understandable that in practical applications, in order to meet the needs of more applications, the surface structure of the projection screen can be divided into more areas. According to the projection light incident on different areas of the projection screen at different incident angles, the corresponding areas are designed to be transparent. Microstructure to adjust the emission range of the light emitted from the screen respectively.

It must be emphasized that a projection screen provided by the present invention has been introduced in detail above. Specific examples are used in this article to illustrate the principle and implementation of the present invention. The description of the above examples is only used to help understand the method and core idea of the present invention. It should be pointed out that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

100: Transparent microstructure

101: Light incident surface

102: light reflecting surface

103: reflective layer

Claims (14)

A projection screen includes a screen body, which further includes a surface structure arranged on the projection surface of the screen body; the surface structure includes a matrix-arranged transparent microstructure array and a reflective layer, wherein the transparent microstructure includes: A light incident surface that has a convergent effect on the incident light and has a preset focal length. The width of the light incident surface along the first direction is a preset value. The light incident surface is used to adjust the direction of the emitted light in the first direction and the normal line of the screen. The direction in the formed plane is such that the maximum exit angle of the emitted light in the plane formed by the first direction and the screen normal is greater than the incident angle of the incident light in the plane formed by the first direction and the screen normal; A curved light reflection surface within the focal length range of the light incident surface, the reflection layer is provided on the light reflection surface, and the light reflection surface is used to adjust the emitted light in a plane formed by the second direction and the normal line of the screen Direction, so that the maximum exit angle of the emitted light in the plane formed by the second direction and the screen normal is greater than the incident angle of the incident light in the plane formed by the second direction and the screen normal; the first direction and The second direction is parallel to the screen plane and perpendicular to each other; in the plane formed by the second direction and the screen normal, the light reflecting mask has a focal point, and the focal point is located in the transparent microstructure. The projection screen described in item 1 of the scope of patent application, wherein the focal length of the light incident surface is less than twice the distance from the light incident surface to the light reflecting surface. According to the projection screen described in item 1 of the scope of patent application, the light incident surface is a cylindrical surface or a parabolic surface whose main axis is parallel to the second direction. The projection screen described in item 3 of the scope of patent application, wherein the light reflecting surface is a cylindrical surface or a parabolic surface with a main axis parallel to the first direction. The projection screen described in item 4 of the scope of patent application, wherein the central axis of symmetry of the cylindrical or parabolic surface as the light incident surface is not parallel to the screen normal. The projection screen described in item 4 of the scope of patent application, wherein the central axis of symmetry of the cylindrical or parabolic surface as the light reflecting surface is not parallel to the screen normal. According to the projection screen described in item 1 of the scope of patent application, the light incident surface is a spherical or parabolic surface that has a convergent effect on the incident light and has the preset focal length. The projection screen described in item 7 of the scope of patent application, wherein the light reflecting surface is a spherical surface or a parabolic surface. The projection screen described in item 8 of the scope of patent application, wherein the center axis of symmetry of the spherical or parabolic surface as the light incident surface is not parallel to the normal line of the screen. The projection screen described in item 8 of the scope of patent application, wherein the center axis of symmetry of the spherical or parabolic surface as the light reflecting surface is not parallel to the normal line of the screen. The projection screen according to any one of items 1-10 in the scope of patent application, wherein the transparent microstructure further includes a side surface connecting the light incident surface and the light reflecting surface, and the side surface is opposite to the predetermined incident angle. The refracted light formed by the light incident through the end of the light incident surface is parallel, and the side surface is provided with a light absorber. The projection screen according to claim 11, wherein, for a transparent microstructure in the transparent microstructure array, there is a first transparent microstructure that passes through the transparent microstructure and is parallel to the first direction and the screen normal at the same time. Plane, the cross section of the transparent microstructure along the first plane satisfies the following relationship: when tan α

-

Time,

When tan α

-

Time,

When tan θ

-tan α,

When tan θ

-tan α,

Where f is the focal length of the light incident surface of the transparent microstructure, d is the width of the light incident surface in the first direction, h is the distance from the light incident surface to the light reflecting surface, and α is the incident angle of the incident light on the first plane , Θ is the angle between the side surface and the screen normal, γ is the largest first exit angle of the emitted light corresponding to the incident light in the first plane, β is the largest second exit angle of the exit light corresponding to the incident light in the first plane , The exit light corresponding to the first exit angle and the exit light corresponding to the second exit angle are respectively located on both sides of the normal line of the screen. The projection screen according to item 11 of the scope of patent application, wherein the light absorber is filled between adjacent sides of the transparent microstructure. The projection screen according to claim 1, wherein the surface structure at least includes a first area and a second area, and the first area and the second area respectively correspond to the central area and the second area of the projection screen. The edge area makes the main optical axis of the light incident surface of the transparent microstructure located in the first area not parallel to the main optical axis of the light incident surface of the transparent microstructure located in the second area.

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