CN115128896B

CN115128896B - Screen and system

Info

Publication number: CN115128896B
Application number: CN202210910538.0A
Authority: CN
Inventors: 林正健; 侯蕊
Original assignee: Qingdao Hisense Laser Display Co Ltd
Current assignee: Qingdao Hisense Laser Display Co Ltd
Priority date: 2022-07-29
Filing date: 2022-07-29
Publication date: 2024-06-11
Anticipated expiration: 2042-07-29
Also published as: CN115128896A

Abstract

Provided are a screen and a system which can suppress the increase in brightness when black is displayed and suppress the extent to which a video is displayed on a ceiling or floor. The screen reflects the video light projected from the video source. The screen includes a screen main body portion and a plurality of prism portions. The plurality of prisms are respectively formed on the surface of the screen main body portion. The plurality of prism portions each have an incidence surface of the video light. The plane of incidence is inclined relative to the plane of the screen. A region where the incident angle of the video light becomes the brewster angle exists in a prescribed region including a partial region of the screen.

Description

Screen and system

Technical Field

The application relates to a screen and a system.

Background

In recent years, the market for projectors (projectors) including ultra-short focal projection optical systems is expanding. For example, when video light is projected from below to a screen by such a projector, a part of the video light is reflected on the screen, and a problem arises in that a video is displayed on a ceiling.

Japanese patent application laid-open No. 2014-71283 (patent document 1) discloses a reflection screen. In the reflection screen, a plurality of fine concave portions are formed on the surface. In this way, when the video light is projected from below the reflective screen, it is possible to suppress a problem that the video light reflected at the interface reaches the ceiling and the video is displayed on the ceiling (see patent document 1).

Prior art literature

Patent literature

Patent document 1: japanese patent laid-open publication No. 2014-71283

Disclosure of Invention

When a fine concave portion is formed on the surface of the screen as in the reflection screen disclosed in patent document 1, ambient light other than video light is diffusely reflected at the screen. The brightness rises when, for example, black is displayed due to diffuse reflection of ambient light at the screen. As a result, the contrast of the video displayed on the screen is lowered.

The present application has been made to solve the above-described problems, and an object of the present application is to provide a screen and a system capable of suppressing an increase in luminance when black is displayed, and capable of suppressing the degree of display of a video on a ceiling when video light is projected from below the screen or suppressing the degree of display of a video on a floor when video light is projected from above the screen.

The screen of one aspect of the application reflects the video light projected from the video source. The screen includes a screen main body portion and a plurality of prism portions. The plurality of prisms are respectively formed on the surface of the screen main body portion. The plurality of prism portions each have an incidence surface of the video light. The plane of incidence is inclined relative to the plane of the screen. A region where the incident angle of the video light becomes the brewster angle exists within a predetermined region including a partial region of the screen.

According to this screen, since the incidence surface of the video light is inclined and the area where the reflectance of the video light is high is reduced, it is possible to suppress the increase in luminance when black is displayed and suppress the extent to which the video is displayed on the ceiling or floor.

In the above screen, when the video source projects a video from the screen obliquely downward, the predetermined area may be an area extending in the upward and downward directions by a length of not more than 25% of the length of the screen in the height direction, based on the edge of the upper end of the screen; when the video source projects a video on the screen from an obliquely upward direction of the screen, the predetermined area may be an area extending in the upward-downward direction by a length of not more than 25% of the length of the screen in the height direction, based on a side of the lower end of the screen.

In this screen, a predetermined area where the incident angle of the video light becomes the brewster angle exists: and a position near one of the upper side and the lower side of the screen, which is farther from the video source. That is, the predetermined area exists at a position near the edge of the upper end of the screen when the video source projects video light from obliquely below the screen toward the screen, and at a position near the edge of the lower end of the screen when the video source projects video light from obliquely above the screen toward the screen. In this way, compared to the case where a predetermined region where the incident angle of the video light becomes the brewster angle exists near the center of the screen, the reflectance of the video light is reduced near one of the upper end side and the lower end side of the screen which is farther from the video source. Therefore, according to this screen, since the area where the reflectance of the video light is high is reduced, it is possible to suppress the increase in luminance when black is displayed and suppress the extent to which the video is displayed on the ceiling or floor.

In the screen, the inclination angles of the incident surfaces of the respective prism portions may be individually set so that the incident angle of the video light with respect to the incident surface becomes substantially the brewster angle; alternatively, the inclination angles of the incident surfaces of the respective prism portions of the plurality of prism portions may be set to be all the same so that the incident angle of the video light with respect to the incident surface becomes substantially the brewster angle.

According to this screen, the inclination angles of the incident surfaces of the respective prism portions are set individually or the inclination angles of the incident surfaces of the respective prism portions are set to be all the same so that the incident angle of the video light becomes substantially the brewster angle, and the area where the reflectance of the video light is high in the entire screen is reduced, so that it is possible to suppress the rise in luminance when black is displayed and suppress the degree of display of the video on the ceiling or floor.

In the screen, the screen main body may include a reflective layer that reflects light transmitted through each of the plurality of prism portions.

In the above screen, the screen main body portion may further include an optical absorption layer provided in front of the reflection layer.

In the screen, the screen main body may further include a fresnel lens or a prism-like optical mechanism provided in front of the reflection layer.

When the video source projects a video from the obliquely downward direction of the screen, the incident angle of the video light at the upper center portion of the screen may be 70 ° or more. The incidence angle of the visual light at the central portion of the lower end of the screen is 70 DEG or more when the visual source projects a visual from the obliquely upward direction of the screen to the screen.

A system of another aspect of the application includes a video source and a screen. The screen reflects the video light projected from the video source. The screen includes a screen body portion and a plurality of prism portions. The plurality of prisms are respectively formed on the surface of the screen main body portion. The plurality of prism portions each have an incidence surface of the video light. The plane of incidence is inclined relative to the plane of the screen. The video light is polarized light.

In this system, the video light projected by the video source is polarized light. As the angle of incidence of polarized light with respect to the screen decreases, the reflectivity of the video light decreases. Therefore, according to this system, since the incident angle of the video light is reduced by the plurality of prism portions, the area where the reflectance of the video light is high is reduced, and therefore, the luminance rise at the time of displaying black can be suppressed, and the degree of displaying the video on the ceiling or the floor can be suppressed.

In the above system, the video source may include a laser light source or a fluorescent light source or an LED light source.

In the above system, the video source may further include a polarization member having polarization selectivity, and the projected video light may be transmitted through the polarization member.

The screen comprised by the above system may be the screen of the present application described above.

According to this system, since the area of the screen where the reflectance of the visual light (polarized light) is high is reduced, it is possible to suppress the increase in brightness when black is displayed and suppress the extent to which the visual image is displayed on the ceiling or floor.

According to the present application, it is possible to provide a screen and a system capable of suppressing an increase in brightness when black is displayed and suppressing the extent to which a video is displayed on a ceiling or floor.

Drawings

Fig. 1 is a diagram schematically showing a system of an embodiment.

Fig. 2 is a diagram schematically showing a screen from obliquely above.

Fig. 3 is a diagram schematically showing a front surface of a screen.

Fig. 4 is a view schematically showing a III-III section of a screen.

Fig. 5 is a diagram schematically showing the back surface of the screen.

Fig. 6 is a diagram for explaining a problem that occurs when a plurality of prism portions are not formed on a screen.

Fig. 7 is a diagram showing an example of a relationship between an incident angle and a reflectance of polarized light.

Fig. 8 is a diagram for explaining differences in projection areas of views at respective positions of the ceiling.

Fig. 9 is a diagram for explaining how the incident angle of the video light changes due to the inclination of the incident surface of each prism portion with respect to the plane on which the screen is located.

Fig. 10 is a diagram for explaining how the reflectance of the visual light changes due to the formation of each prism portion on the outermost surface of the screen.

Fig. 11 is a diagram for explaining a predetermined region of a screen in which video light is present at a position where the video light is incident at an angle corresponding to the brewster angle.

Fig. 12 is a diagram for explaining how black luminance and ceiling light normally change according to whether the type of reflection is specular reflection or diffuse reflection.

Fig. 13 is a view schematically showing an example in which the inclination angles of the prism portions are different.

Fig. 14 is a diagram schematically showing a rear surface of a screen provided with a prism-like optical mechanism including a plurality of prism portions.

Fig. 15 is a view schematically showing an XV-XV cross section in fig. 14.

Fig. 16 is a view schematically showing a screen in which a prism portion is formed only in an upper portion from obliquely above.

Description of the reference numerals

10 System, 100 screen, 110 screen main body, 112 prism, 113 incident surface, 114 incident light layer base, 120 optical absorption layer, 130 fresnel lens layer, 140 diffuse reflection layer, 200 video source, 250, 300 room, 310 floor, 320 ceiling, 330 wall, A1, A2 region, L1, L2, L3 curve, L10, L11, L12 length, LI1 video light, LP1 light path, P1, P2, P3 video, S1, S2 side, X1, X2 angle range.

Detailed Description

Hereinafter, an embodiment of an aspect of the present application (hereinafter, also referred to as "the present embodiment") will be described in detail with reference to the drawings. Note that the same or corresponding portions in the drawings are denoted by the same reference numerals, and the description thereof is omitted. Also, the drawings omit or exaggerate and schematically describe objects as appropriate for ease of understanding.

[1. Structure of System ]

Fig. 1 is a diagram schematically showing a system 10 according to the present embodiment. As shown in fig. 1, system 10 includes a screen 100 and a video source 200. The system 10 is for example arranged inside a room 300. The screen 100 is mounted, for example, to a wall 330 of the room 300. The video source 200 is disposed on a table 250 provided on a floor 310 of the room 300, for example.

The video source 200 is constituted by, for example, a projector. The projector includes a projection optical system with an ultra-short focus. Hereinafter, a projector including a projection optical system having an ultra-short focus is also referred to as an "ultra-short focus projector". The video source 200 is disposed, for example, at a position separated from the screen 100 by about 30cm in the normal direction of the screen 100. In a preferred form, the video source 200 projects video light toward the screen 100 from a position diagonally below the screen 100. Thus, a visual image of, for example, about 80 inches is displayed on the screen 100. The video source 200 may project the video light toward the screen 100 from a position obliquely above the screen 100.

The video source 200 comprises, for example, a laser light source, or a fluorescent light source, or an LED light source, but preferably a laser light source, especially a video source 200 comprising a red laser light source, a green laser light source, and a blue laser light source. In a preferred embodiment, the video source 200 projects video light generated by laser light emitted from each laser light source toward the screen 100. Since the video light projected by the video source 200 is generated by laser light, polarized light is emitted substantially in a specific direction. For example, in the most ideal case, the video light projected by the video source 200 contains 100% of polarized light that is P polarized light. The polarized light included in the video light projected by the video source 200 may be, for example, 90% or more of P polarized light, and less than 10% of S polarized light.

In general, the video light projected by an ultra-short focus projector is reflected on the surface of a screen, and there is a problem in that the reflected video light is displayed on the ceiling of a room. In order to solve such a problem, a method of suppressing reflection of video light on a screen by forming fine irregularities on the surface of the screen is conceivable. However, when fine irregularities are formed on the surface of the screen, ambient light other than the visual light is diffusely reflected on the screen. As ambient light is diffusely reflected on the screen, the brightness rises when, for example, black is displayed on the screen. As a result, the contrast of the video displayed on the screen is lowered.

In the system 10 of the present embodiment, by improving the structure of the screen 100, it is possible to suppress an increase in brightness when black is displayed on the screen 100, and to suppress the extent to which a video is displayed on the ceiling. Hereinafter, the structure of the screen 100 is described in detail.

[2. Screen Structure ]

Fig. 2 is a diagram schematically showing the screen 100 from obliquely above. Fig. 3 is a diagram schematically showing the front surface of the screen 100. Fig. 4 is a view schematically showing a III-III section of the screen 100. Fig. 5 is a diagram schematically showing the back surface of the screen 100.

Referring to fig. 2, 3, 4, and 5, the screen 100 has a rectangular shape when viewed from the front and rear surfaces, respectively. The screen 100 reflects the video light projected from the video source 200 toward the user side (front surface side). In the system 10, the user views the screen 100 from the front surface side of the screen 100.

The screen 100 includes a screen main body portion 110 and a plurality of prism portions 112. The plurality of prism portions 112 are formed on the front surface side of the screen main body portion 110, respectively. That is, a plurality of prism portions 112 are formed on the outermost surface of the front surface side of the screen 100. In the example shown in fig. 2, the prism portion 112 is formed on the entire front surface side of the screen 100. The plurality of prism portions 112 each linearly extend in the width direction of the screen 100 and have a triangular cross-sectional shape. The plurality of prism portions 112 protrude toward the front surface side, respectively. The plurality of prism portions 112 are arranged in the height direction of the screen 100.

Each of the plurality of prism units 112 has an incidence surface 113 on which the video light projected from the video source 200 is incident. Each of the incident surfaces 113 is inclined with respect to a plane in which the screen is located. Here, the plane on which the screen is located is, for example, a plane parallel to the front surface side of the screen main body 110. Each of the incident surfaces 113 is inclined such that an incident angle of the video light with respect to the incident surface 113 is smaller than an incident angle of the video light with respect to a plane in which the screen is located. For example, in the case of projecting video light from the obliquely lower video source 200 onto the screen 100, the inclination angle is formed in each of the incident surfaces 113 as follows: that is, the upper end of the incident surface 113 is more protruded than the lower end of the incident surface 113 with respect to the screen main body 110.

In the case where the video source 200 projects the video light onto the screen 100 from obliquely above, the inclination angle may be formed on each of the incident surfaces 113 as follows: that is, the lower end of the incident surface 113 is more protruded than the upper end of the incident surface 113 with respect to the screen main body 110.

The material constituting each prism portion 112 is not particularly limited. Examples of the material of each prism portion 112 include transparent resins containing at least one of propylene, styrene, polycarbonate (PC), polyethylene terephthalate (PET), acrylonitrile, and the like as a main component, and epoxy acrylate-based or urethane acrylate-based reactive resins (ionizing radiation-curable resins, and the like).

The screen main body 110 includes a light entrance layer base 114, an optical absorption layer 120, a fresnel lens layer 130, and a diffuse reflection layer 140. In the screen main body 110, a light-entering layer base 114, an optical absorption layer 120, a fresnel lens layer 130, and a diffuse reflection layer 140 are arranged in this order from the front surface toward the back surface of the screen 100. The light entrance layer base 114 is, for example, a base of the plurality of prism portions 112, and is integrally formed with the plurality of prism portions 112. That is, the light entrance layer base 114 is formed of the same material as each of the plurality of prism portions 112.

The optical absorption layer 120 suppresses an increase in black luminance caused by ambient light by absorbing a part of the ambient light. The material constituting the optical absorption layer 120 is not particularly limited. Examples of the base material of the optical absorption layer 120 include resins such as PET, PC, methyl Methacrylate Butadiene Styrene (MBS), acryl, and triacetyl cellulose (TAC). The optical absorption layer 120 also contains, for example, a pigment or dye that absorbs a portion of the ambient light for improving the contrast of the visual light.

The fresnel lens layer 130 includes a plurality of lens structures each formed to extend in an arc shape. The plurality of lens structures protrude toward the rear surface side. In a cross section near the center in the width direction of the screen 100, the back-most surface of each of the plurality of lens structures is inclined in the same direction as the incident surface 113 of each of the prism portions 112, for example. For example, in the case where the video source 200 projects video light from obliquely below toward the screen 100, an inclination angle is formed in each lens structure as follows: the lower end of the lens structure protrudes more than the upper end of the lens structure with respect to the optical absorption layer 120.

In the fresnel lens layer 130, a plurality of lens structures are formed in concentric circles. That is, in the fresnel lens layer 130, a circular fresnel lens is formed. The center of the concentric circles is located, for example, below the screen 100.

The material of the fresnel lens layer 130 is not particularly limited. Examples of the material of the fresnel lens layer 130 include transparent resins containing at least one of propylene, styrene, PC, PET, acrylonitrile, and the like as a main component, and epoxy acrylate-or urethane acrylate-based reactive resins (ionizing radiation-curable resins, and the like).

The diffuse reflection layer 140 diffuses and reflects the video light transmitted through the fresnel lens layer 130. The diffuse reflection layer 140 is formed on each lens structure of the fresnel lens layer 130. That is, in the cross section near the center in the width direction of the screen 100, each of the diffuse reflection layers 140 is inclined, for example, in the same direction as the incident surface 113 of each of the prism portions 112. The diffuse reflection layer 140 is formed by, for example, coating or vapor deposition of a material that reflects light on the fresnel lens layer 130. Examples of the material that reflects light include silver and aluminum. Examples of the film thickness of the diffuse reflection layer 140 include, for example, 1 μm to 30 μm. The diffuse reflection layer 140 does not necessarily need to diffuse or reflect the video light, and may reflect only the video light. That is, the diffuse reflection layer 140 may be constituted only by a reflection layer.

An example of the optical path of the video light incident on the screen 100 is shown by an optical path LP1 in fig. 4. The video light incident from the prism portion 112 passes through the light-incident layer base 114, the optical absorption layer 120, and the fresnel lens layer 130, and is reflected by the diffuse reflection layer 140. The video light reflected at the diffuse reflection layer 140 is directed toward the front surface side of the screen 100, and is emitted from the incident surface 113 of the prism portion 112 to the outside of the screen 100.

As described above, the plurality of prism portions 112 are formed on the outermost surface of the front surface of the screen 100, and the respective incident surfaces 113 of the plurality of prism portions 112 are inclined with respect to the plane in which the screen is located. The reason why the screen 100 has such structural features is described below.

Fig. 6 is a diagram for explaining a problem that occurs when it is assumed that a plurality of prism portions 112 are not formed on the screen 100. Referring to fig. 6, a plurality of prism portions 112 are not formed at the outermost surface of the screen 100A.

A portion of the video light projected by the video source 200 is reflected at the screen 100A. For example, in the ceiling 320, a region A1 between a position where light reflected at the lower end of the screen 100A reaches and a position where light reflected at the upper end of the screen 100A reaches sometimes reflects a visual image. In this case, light reflected particularly near the upper end of the screen 100A becomes conspicuous at the ceiling 320. The reason for this will be described below. In this case, the incident angle θ2 of the video light at the upper end of the screen 100A is larger than the incident angle θ1 of the video light at the lower end of the screen 100A.

Fig. 7 is a diagram showing an example of a relationship between an incident angle and a reflectance of polarized light. Referring to fig. 7, the horizontal axis represents the incident angle of light, and the vertical axis represents the reflectance. The curve L1 shows the relationship between the incident angle and the reflectance of the S-polarized light, and the curve L2 shows the relationship between the incident angle and the reflectance of the P-polarized light. That is, a curve L1 shows the relationship between the incident angle and the reflection angle when 100% of the video light projected from the video source 200 is S-polarized light, and a curve L2 shows the relationship between the incident angle and the reflection ratio when 100% of the video light projected from the video source 200 is P-polarized light. The curve L3 shows the relationship between the incident angle and the reflectance when 90% of the projection light included in the video light projected by the video source 200 is P-polarized light.

As shown by the curves L2 and L3, the reflectance of the video light gradually decreases as the incident angle increases in a range of 0 ° to about 60 ° of the incident angle of the video light with respect to the screen 100A. On the other hand, in a range where the incident angle of the video light to the screen 100A exceeds about 60 °, the reflectance of the video light increases sharply with an increase in the incident angle.

Referring again to fig. 6, the incident angle θ1 of the video light at the lower end of the screen 100A exists in a range of, for example, 0 ° to 40 °. According to the illustrated rule, the reflectance of the video light near the lower end of the screen 100A is comparatively low. On the other hand, the incident angle θ2 of the video light at the upper end center portion of the screen 100A exists in a range of, for example, about 70 ° or more (i.e., the incident angle of the video light at the upper end center portion of the screen 100 is 70 ° or more). Therefore, the reflectance of the video light near the upper end of the screen 100A is relatively high. As a result, light reflected near the upper end of the screen 100A becomes conspicuous at the ceiling 320.

Fig. 8 is a diagram for explaining differences in projection areas of views at respective positions of the ceiling 320. Referring to fig. 8, a video P1 represents an image of a projection area of the video corresponding to video light reflected at the lower end of the screen 100A. The video P2 represents an image of a projection area of the video corresponding to the video light reflected at the center of the screen 100A. The video P3 represents an image of a projection area of the video corresponding to the video light reflected at the upper end of the screen 100A.

In this way, the projection area is smaller as the video corresponding to the video light whose reflection position is close to the upper end of the screen 100A among the video light projected by the video source 200. As the projected area decreases, the light beam per unit area increases and the illuminance increases. That is, the more the reflection position is near the upper end of the screen 100A, the higher the illuminance is, and therefore the light reflected near the upper end of the screen 100A becomes noticeable at the ceiling 320. For two main reasons, light reflected near the upper end of the screen 100A becomes noticeable at the ceiling 320.

In order to solve such a problem, in the screen 100 of the present embodiment, a plurality of prism portions 112 are formed on the outermost surface of the front surface of the screen 100, and each incident surface 113 of the plurality of prism portions 112 is inclined with respect to the plane in which the screen is located. The reason why the above-described problem can be solved by such structural features will be described below.

Fig. 9 is a diagram for explaining how the incident angle of the video light changes due to the inclination of the incident surface 113 of each prism portion 112 with respect to the plane in which the screen is located. Referring to fig. 9, in this example, the inclination angle of each prism portion 112 is θp. The incident angle of the video light LI1 with respect to the plane of the screen is θi, and the incident angle of the video light LI1 with respect to the incident surface 113 is θip. Between θp, θi, and θip, the following expression (1) holds.

θip＝θi-θp…(1)

That is, by setting the inclination angle of each prism portion 112 to θp, the incident angle of the video light to each prism portion 112 is reduced by θp.

Fig. 10 is a diagram for explaining how the reflectance of the visual light changes due to the formation of each prism portion 112 on the outermost surface of the screen 100. Referring to fig. 10, the horizontal axis represents the incident angle of light, and the vertical axis represents the reflectance. The incident angle of the video light in each region of the screen 100 converges to an angle range X1. The entire angle range X1 slides in a direction to decrease θp (i.e., slides in the left direction in fig. 10) as compared with the case where it is assumed that the plurality of prism portions 112 are not formed on the outermost surface of the screen 100.

Since the entire angle range X1 slides in the direction of decreasing θp, for example, the angle range X1 no longer includes an angle at which the reflectance becomes equal to or higher than the predetermined reflectance. The predetermined reflectance is preferably, for example, 0.1. For example, the angular range X1 includes the brewster angle. The brewster angle is an incident angle at which the reflectance of P-polarized light becomes 0 at the interface between substances having different refractive indices.

Fig. 11 is a diagram for explaining a predetermined region on the screen 100 at a position where the video light is incident at an angle corresponding to the brewster angle. Referring to fig. 11, when the video source 200 projects the video light onto the screen 100 from obliquely below, the predetermined area is an area A2 extending upward by a length L11 and downward by a length L12 with respect to a side S1 at the upper end of the screen 100. The lengths L11 and L12 are each preferably 25% of the length L10 in the height direction of the screen 100, more preferably 15% of the length L10, and even more preferably 5% of the length L10. Further, the position where the video light is incident at an angle corresponding to the brewster angle is more preferably located at any one of the center Y1, the right end Y3, and the left end Y2 of the side S1 at the upper end of the screen 100.

When the video source 200 projects the video light onto the screen 100 from obliquely above, the predetermined region may be a region extending upward by a length L11 and downward by a length L12 with respect to the side S2 at the lower end of the screen 100.

Referring again to fig. 10, since the position where the video light is incident at the angle corresponding to the brewster angle exists in the predetermined region, the angle range X1 no longer includes an angle (for example, about 75 ° or more) at which the reflectance is high. Therefore, according to the screen 100, reflection of the visual light on the surface can be suppressed without forming fine irregularities on the surface. As a result, according to the screen 100, the increase in brightness when black is displayed can be suppressed, and the degree to which a video is displayed on the ceiling 320 or the floor 310 can be suppressed.

[3. Characteristics ]

As described above, in the screen 100 of the present embodiment, since each prism portion 112 has an inclination angle, the incident angle of the video light becomes smaller than in the case where the prism portion 112 is not formed. As a result, a predetermined region in which the incident angle of the video light becomes the brewster angle exists in the vicinity of one of the upper side S1 and the lower side S2 of the screen 100, which is far from the video source 200. As described above, the brewster angle refers to an incident angle at which the reflectance of P-polarized light becomes 0 at the interface of substances having different refractive indices.

Referring again to fig. 11, since the predetermined region where the incident angle of the video light becomes the brewster angle is present, for example, in the vicinity of the side S1 at the upper end of the screen 100, the reflectance of the video light is reduced in the vicinity of the side S1 at the upper end of the screen 100 even if the incident angle of the video light at the upper end central portion of the screen 100 is 70 ° or more, compared to the case where the predetermined region where the incident angle of the video light becomes the brewster angle is present in the vicinity of the center of the screen 100. Therefore, according to the screen 100, since the area where the reflectance of the video light is high is reduced, the increase in luminance when black is displayed can be suppressed, and the degree of display of the video on the ceiling 320 or the floor 310 can be suppressed.

In the system 10 of the present embodiment, the video light projected by the video source 200 is polarized light. As the angle of incidence of polarized light with respect to the screen 100 decreases, the reflectivity of the video light decreases. In the screen 100, since each prism portion 112 has an inclination angle, the incident angle of the video light is reduced as compared with the case where the prism portion 112 is not formed. The principle of decreasing the incident angle of the video light can be referred to the above formula (1). Therefore, according to the system 10, referring to the above formula (1), since the inclination angle θp is set for each prism portion 112, when the video light LI1 is incident on the screen, the incident angle θi of the video light LI1 with respect to the plane of the screen is reduced by this inclination angle θp, and as a result of the reduction of the incident angle θi, the incident angle θip of the video light LI1 with respect to the incident surface 113 of the prism portion 112 falls in the vicinity of (or includes) the brewster angle, and thus the area where the reflectance of the video light in the screen 100 is high is reduced, and thus the image light beam directed to reflect onto the ceiling is reduced (in the state of being used in projection obliquely upward), and thus the ceiling phenomenon is improved. In addition, since the diffuse reflection structure is not used, ambient light is reduced due to diffuse reflection into human eyes in a black scene, and thus, the luminance rise at the time of black can be improved. In addition, if the projection is used in a state of projecting obliquely downward, the image beam directionally reflected to the floor is reduced, and therefore, the degree of displaying the video on the floor 310 can be suppressed.

Fig. 12 is a diagram for explaining how black luminance and ceiling light normally change according to whether the type of reflection is specular reflection or diffuse reflection. As shown in fig. 12, in a normal case, if the surface of the screen is processed to cause diffuse reflection, the brightness of the video projected on the ceiling is lowered, but the black brightness is increased. On the other hand, if the surface of the screen is processed to cause specular reflection, the black luminance decreases, but the luminance of the video projected on the ceiling increases. As described above, in the screen 100, the prism portion 112 is formed on the screen main body portion 110 without performing processing for generating diffuse reflection on the surface, thereby reducing the brightness of the video projected on the ceiling. Therefore, according to the screen 100, the increase in brightness at the time of displaying black can be suppressed, and the degree of displaying a video on the ceiling 320 or the floor 310 can be suppressed.

[4 ] Other embodiments ]

The idea of the above embodiment is not limited to the embodiment described above. An example of another embodiment to which the idea of the above embodiment can be applied will be described below.

<4-1>

In the screen 100 of the above embodiment, in a part of the predetermined area, the respective inclination angles of the plurality of prism portions 112 are unified so that the incident angle of the video light becomes the brewster angle. However, the respective inclination angles of the plurality of prism portions 112 are not necessarily uniform. For example, the inclination angle of the incident surface 113 in each of the plurality of prism portions 112 may be set individually such that the incident angle of the video light with respect to the incident surface 113 becomes approximately the brewster angle.

Fig. 13 is a view schematically showing an example in which the inclination angles of the prism portions are different. Referring to fig. 13, for example, prism portions 112A, 112B, 112C are arranged from top to bottom. The inclination angles of the prism portions 112A, 112B, 112C are θ11, θ12, θ13, respectively. For example, a relationship of θ11> θ12> θ13 may be set. Since the incidence angle of the video light increases as the prism portion is positioned above the screen, the incidence angle of the video light at each prism portion can be made to be substantially the brewster angle by increasing the inclination angle of the prism portion as the prism portion is positioned above the screen.

According to such a screen 100, since the incident angle of the video light becomes substantially the brewster angle in each of the plurality of prism portions 112 and the area where the reflectance of the video light is high in the entire screen 100 is reduced, it is possible to suppress the increase in luminance when black is displayed and to suppress the extent to which the video is displayed on the ceiling 320 or the floor 310.

<4-2>

In addition, the screen 100 of the above embodiment includes the fresnel lens layer 130. However, the screen 100 may not necessarily include the fresnel lens layer 130. The screen 100 may include a prism-like optical mechanism having a plurality of prism portions, for example, instead of the fresnel lens layer 130. Fig. 14 is a diagram schematically showing the back surface of a screen 100A provided with a prism-like optical mechanism including a plurality of prism portions. Fig. 15 is a view schematically showing an XV-XV cross section in fig. 14. Referring to fig. 14 and 15, the prism-like optical mechanism 130A includes a plurality of prism portions that are linearly arranged along the width direction of the screen 100A. Each prism portion has a triangular cross-sectional shape and protrudes toward the rear surface side. The prism portions are aligned in the height direction of the screen 100A. For example, a diffuse reflection layer 140 may be formed on the back surface of the prism-shaped optical mechanism 130A, and the prism-shaped optical mechanism 130A may transmit the visual light reflected by the diffuse reflection layer 140 forward.

<4-3>

In the above embodiment, the video source 200 may include a fluorescent light source or an LED light source instead of a plurality of laser light sources. The viewing source 200 may generally project the polarized viewing light toward the screen 100 by using a fluorescent light source or an LED light source. The video source 200 may further include a polarizing member such as a polarizing plate. In this case, for example, light emitted by the light source may be transmitted through the polarized light member.

<4-4>

In the screen 100 of the above embodiment, the optical absorption layer 120 may be a simple base material layer. In this case, the optical absorption layer 120 may not include a pigment or dye that absorbs a part of the ambient light but serves to improve the contrast of the visual light.

<4-5>

In addition, in the screen 100 of the above embodiment, the prism portion 112 is formed on the entire surface of the screen 100. The prism portion 112 is not necessarily formed on the entire surface of the screen 100. For example, in a use state in which the video source projects a video obliquely upward onto the screen 100, the prism portion 112 may be formed only in the upper portion of the screen 100.

Fig. 16 is a view schematically showing, from obliquely above, a screen 100B in which the prism portion 112 is formed only in the upper portion. As shown in fig. 16, in a use state in which the video source projects a video obliquely upward onto the screen 100, in the front surface of the screen 100B, a prism portion 112 is formed only in an upper portion. This makes it possible to reduce the incident angle only in a portion where the incident angle of the video light is large. Similarly, in a use state in which the video source projects a video obliquely downward onto the screen 100, the prism portion 112 may be formed only in the lower portion of the screen, and a specific illustration of this case may be omitted for simplicity of explanation.

The embodiments of the present application are described above by way of example. That is, the detailed description and drawings are disclosed for illustrative purposes. As a result, the components described in the detailed description and the drawings may include components not necessarily required to solve the problem. Therefore, although these unnecessary components are described in the detailed description and drawings, they should not be construed as being necessarily essential.

The above embodiments are merely illustrative of the present application in all respects. The above-described embodiments can be variously modified or changed within the scope of the present application. That is, in the practice of the present application, a specific configuration may be adopted as appropriate according to the embodiment.

Claims

1. A screen that reflects video light projected from a video source, wherein the screen is provided with:

A screen main body portion; and

A plurality of prism parts formed on the surface of the screen main body part,

The plurality of prism portions each have an incident surface of the video light,

The entrance face is inclined with respect to the plane of the screen,

A region in which an incident angle of the video light becomes a brewster angle exists within a prescribed region including a partial region of the screen; the predetermined area is an area extending in the up-down direction by a length not longer than 25% of the length of the screen in the height direction, based on the upper end side of the screen, when the video source projects a video from the screen in the obliquely downward direction of the screen; when the video source projects a video on the screen from an obliquely upward direction of the screen, the predetermined area is an area extending in the upward-downward direction by a length of not more than 25% of the length of the screen in the height direction, based on a side of the lower end of the screen.

2. The screen of claim 1, wherein,

The inclination angles of the incidence surfaces of the respective prism portions are individually set so that the incidence angle of the video light with respect to the incidence surface becomes a brewster angle.

3. The screen of claim 1, wherein,

The inclination angles of the incident surfaces of the respective prism portions are set to be all the same so that the incident angle of the video light with respect to the incident surface becomes a brewster angle.

4. The screen of claim 1, wherein,

The screen main body portion includes a reflection layer that reflects light transmitted through each of the plurality of prism portions.

5. The screen of claim 4, wherein,

The screen main body portion further includes:

An optical absorption layer disposed in front of the reflection layer; and

A fresnel lens or a prismatic optical mechanism provided in front of the reflective layer.

6. The screen of claim 1, wherein,

When the video source projects a video from obliquely downward direction of the screen to the screen, an incident angle of the video light at an upper end central portion of the screen is 70 ° or more;

the incidence angle of the visual light at the central portion of the lower end of the screen is 70 DEG or more when the visual source projects a visual from the obliquely upward direction of the screen to the screen.

7. A projection system, wherein the system comprises:

A video source; and

A screen reflecting the video light projected from the video source,

The screen includes:

A screen main body portion; and

A plurality of prism parts formed on the surface of the screen main body part,

The entrance face is inclined with respect to the plane of the screen,

8. The projection system of claim 7, wherein,

The visual source comprises a laser light source or a fluorescent light source or an LED light source.

9. The projection system of claim 7 or 8, wherein,

The video source further includes a polarized light member having polarized light selectivity,

The projected video light is transmitted through the polarized light member.

10. The projection system of claim 7 or 8, wherein,

The screen is the screen of any one of claims 1 to 6.