Projection screen and projection system

Abstract

The invention discloses a projection screen and a projection system. The projection screen comprises a surface function layer, a Fresnel structure layer and reflection structure layers located on Fresnel structures in the Fresnel structure layer. Any at least one light-transmitting film layer in the projection screen can contain a low-valence oxide, and the low-valence oxide can reduce the transmittance to a visible light wave band, so that an absorption layer does not need to be independently arranged in the projection screen, the cost is reduced, the structure is simplified, incident ambient light can be absorbed when a black image is displayed, and the brightness of the projection screen is improved. And the black brightness of the projection screen is improved.

Description

Technical Field

[0001] The present invention relates to the field of projection display technology, and in particular to a projection screen and a projection system. Background Art

[0002] As display products continue to develop towards large-scale, considering power consumption, weight and size, the market for projection display products as large-screen products to replace LCD and organic electroluminescent (EL) TVs is rapidly expanding. The current front projection system can usually be used with a projection screen. The projection light is emitted by the projection device, and the projection light is incident on the projection screen. After being reflected by the projection screen, it is incident on the human eye and the projected image is viewed.

[0003] White matte projection screens can evenly reflect light from the light source and are inexpensive. However, white matte projection screens are easily affected by external light when viewed under strong light, and are not suitable for watching movies and other images that often use dark scenes. In order to overcome the above problems, an absorption layer is usually added to the projection screen to absorb ambient light and reduce the brightness of the ambient light. However, since the absorption layer also absorbs the emitted light of the projection light source, the brightness of the projection light is lost, and the cost of the projection screen also increases. Summary of the invention

[0004] According to a first aspect of an embodiment of the present invention, a projection screen is provided, comprising:

[0005] Surface functional layer;

[0006] A Fresnel structure layer is located on one side of the surface functional layer; a surface of one side of the Fresnel structure layer has a plurality of Fresnel structures, and the Fresnel structure includes an inclined surface that is inclined relative to the plane where the surface functional layer is located; and

[0007] A reflective structure layer at least covers the inclined surfaces of the Fresnel structures of the Fresnel structure layer;

[0008] Wherein, any light-transmitting film layer in the projection screen contains low-valent oxides; the low-valent oxides are used to reduce the transmittance in the visible light band.

[0009] In some embodiments of the present invention, the subvalent oxide is a metal subvalent oxide;

[0010] The absorption capacity of the low-valent oxide to the visible light band decreases with the increase of oxygen content.

[0011] In some embodiments of the present invention, the reflectivity of the reflective structure layer to the light emitted by the projection device is greater than the reflectivity of light in other wavelength bands.

[0012] In some embodiments of the present invention, the reflective structure layer includes:

[0013] Reflective layer; and

[0014] At least one film layer group is located on a side of the reflective layer facing the surface functional layer; the film layer groups are stacked;

[0015] Wherein, the film layer group comprises:

[0016] a semi-transmissive layer, located on a side close to the surface functional layer; and

[0017] The light-transmitting medium layer is located between the semi-transmitting layer and the reflective layer; the product of the refractive index and the thickness of the light-transmitting medium layer satisfies the condition for causing the outgoing light of the projection device to resonate.

[0018] In some embodiments of the present invention, the light-transmitting medium layer includes the low-valent oxide.

[0019] In some embodiments of the present invention, the light-transmitting medium layer comprises the low-valent oxide and the complete oxide;

[0020] The light-transmitting dielectric layer comprises a first dielectric layer and a second dielectric layer which are stacked; wherein the first dielectric layer is made of low-valent oxide and the second dielectric layer is made of complete oxide; or, the first dielectric layer is made of complete oxide and the second dielectric layer is made of low-valent oxide.

[0021] In some embodiments of the present invention, the low-valent oxide is Nb2O 5-x 、TiO 2-y or Ta2O 5-z One of;

[0022] Among them, 0<x<5, 0<y<2, 0<z<5.

[0023] In some embodiments of the present invention, the absorption capacity of the reflective structure layer decreases with the increase of oxygen content.

[0024] In some embodiments of the present invention, the semi-transparent layer is a laminated structure formed by at least one metal selected from aluminum, niobium, silver and titanium; the thickness of the semi-transparent layer is 2nm to 20nm;

[0025] The material of the reflective layer is aluminum, aluminum alloy, silver or silver alloy; the thickness of the reflective layer is greater than 50nm;

[0026] The product of the thickness and the refractive index of the light-transmitting medium layer is 1200-1800.

[0027] In some embodiments of the present invention, the projection screen further comprises: an adhesive layer located between the surface functional layer and the Fresnel structure layer;

[0028] The Fresnel structure of the Fresnel structure layer is located on the side opposite to the surface functional layer; the adhesive layer is used to bond the surface functional layer to the surface of the Fresnel structure layer on the side opposite to the Fresnel structure;

[0029] Alternatively, the Fresnel structure of the Fresnel structure layer is located on a side facing the surface functional layer; and the adhesive layer is used to bond the surface functional layer and the reflective structure layer on the Fresnel structure to each other.

[0030] In some embodiments of the present invention, the surface functional layer comprises:

[0031] A first substrate in contact with the adhesive layer; and

[0032] a diffusion material, located on a surface of the first substrate opposite to the adhesive layer;

[0033] Alternatively, the surface functional layer comprises:

[0034] A first substrate in contact with the adhesive layer; the first substrate contains a diffusion material;

[0035] Alternatively, the surface functional layer comprises:

[0036] The first substrate is in contact with the adhesive layer; the surface of the first substrate opposite to the adhesive layer is an uneven surface.

[0037] In some embodiments of the present invention, the surface functional layer is located on the surface of the reflective structure layer on the side opposite to the Fresnel structure;

[0038] The surface functional layer is a diffusion material covering the reflective structure layer.

[0039] According to a second aspect of an embodiment of the present invention, a projection system is provided, comprising:

[0040] A projection device for emitting projection light; and

[0041] A projection screen, located at the light-emitting side of the projection device, wherein the projection screen is any of the above-mentioned projection screens;

[0042] Wherein, the projection device is an ultra-short-throw laser projection device; the projection device comprises:

[0043] A three-color laser light source device, used for emitting three-primary-color lasers;

[0044] a light modulation component, located at the light output side of the three-color laser light source device, and used to modulate the output laser light of the three-color laser light source device; and

[0045] The projection lens is located at the light-emitting side of the light modulation component. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings introduced below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0047] Figure 1 A schematic diagram of the structure of a projection system provided by an embodiment of the present invention;

[0048] Figure 2 One of the structural schematic diagrams of the projection screen provided by the embodiment of the present invention;

[0049] Figure 3 A curve showing changes in optical parameters of a metal complete oxide provided by an embodiment of the present invention;

[0050] Figure 4 A curve showing changes in optical parameters of metal suboxides provided by an embodiment of the present invention;

[0051] Figure 5 A curve showing the change of oxidation number with the flow rate of reactive gas in the reactive sputtering process of plasma luminescence control provided by an embodiment of the present invention;

[0052] Figure 6 A curve showing the change of oxygen partial pressure with the flow rate of reactive gas in the reactive sputtering process controlled by plasma luminescence provided by an embodiment of the present invention;

[0053] Figure 7 A curve showing the variation of the extinction coefficient with the reactive gas flow rate in the reactive sputtering process for plasma luminescence control provided by an embodiment of the present invention;

[0054] Figure 8 One of the structural schematic diagrams of the reflective structure layer provided in an embodiment of the present invention;

[0055] Fig. 9 A second structural schematic diagram of a reflective structure layer provided in an embodiment of the present invention;

[0056] Fig.10 The reflectivity curve of the reflective structure layer provided by the embodiment of the present invention to light of different wavelength bands;

[0057] Fig.11A curve showing the change of film forming speed with the flow rate of reactive gas in the reactive sputtering process controlled by plasma luminescence provided by an embodiment of the present invention;

[0058] Fig.12 A second structural schematic diagram of a projection screen provided by an embodiment of the present invention;

[0059] Fig.13 A third structural schematic diagram of a projection screen provided by an embodiment of the present invention;

[0060] Fig.14 A fourth structural schematic diagram of a projection screen provided in an embodiment of the present invention;

[0061] Fig.15 A fifth structural schematic diagram of a projection screen provided in an embodiment of the present invention;

[0062] Fig.16 A sixth structural schematic diagram of a projection screen provided in an embodiment of the present invention;

[0063] Fig.17 A seventh structural diagram of a projection screen provided in an embodiment of the present invention;

[0064] Fig.18 A schematic diagram of the structure of a projection device provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0065] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and understandable, the present invention will be further described below with reference to the accompanying drawings and examples. However, the exemplary embodiments can be implemented in various forms and should not be understood as being limited to the embodiments described herein; on the contrary, these embodiments are provided to make the present invention more comprehensive and complete, and to fully convey the concepts of the exemplary embodiments to those skilled in the art. The same figure marks in the figures represent the same or similar structures, and thus their repeated descriptions will be omitted. The words expressing position and direction described in the present invention are all explained using the accompanying drawings as examples, but changes can be made as needed, and the changes made are all included in the scope of protection of the present invention. The drawings of the present invention are only used to illustrate the relative position relationship and do not represent the true proportions.

[0066] With the popularity of laser display products, the market for laser TVs has expanded rapidly as a large-screen product to replace LCD and organic EL TVs. In order to achieve better brightness and display effects, projection equipment is generally used with a projection screen.

[0067] Figure 1 A schematic diagram of the structure of a projection system provided by an embodiment of the present invention.

[0068] like Figure 1As shown, the projection system includes: a projection device 2 and a projection screen 1.

[0069] The projection screen 1 is located on the light emitting side of the projection device 2. The audience faces the projection screen 1. The projection device 2 emits projection light, which is incident on the projection screen 1 and reflected toward the audience's position through the projection screen 1, so that the audience can see the projected image.

[0070] The ultra-short-throw projection device has the characteristics of short projection distance and large projection screen, and is very suitable for application in the home field. The projection system provided by the embodiment of the present invention can adopt the ultra-short-throw projection device.

[0071] The projection screen used in the current front projection projection system can be a white matte projection screen, which can evenly reflect the light from the light source and is inexpensive. However, the white matte projection screen is easily affected by external light when viewed under strong light, and is not suitable for watching movies and other images that often use dark scenes. In order to overcome the above problems, an absorption layer is usually added to the projection screen to absorb ambient light and reduce the brightness of the ambient light. However, since the absorption layer also absorbs the emitted light of the projection light source, the brightness of the projection light is lost, and the cost of the projection screen will also increase.

[0072] In view of this, an embodiment of the present invention provides a projection screen. Figure 2 This is one of the structural schematic diagrams of the projection screen provided in the embodiment of the present invention.

[0073] like Figure 2 As shown, the projection screen provided by the embodiment of the present invention includes: a surface functional layer 11, a Fresnel structure layer 12 and a reflective structure layer F.

[0074] The surface functional layer 11 is located on the outermost surface of the projection screen. In the embodiment of the present invention, the surface functional layer 11 is located on the side closest to the audience, and plays a role in protecting the projection screen. In addition, the surface functional layer 11 can also be processed in a variety of ways according to different needs to achieve the effects of expanding the viewing angle, resisting ambient light reflection, and resisting ceiling reflection.

[0075] The Fresnel structure layer 12 is located on one side of the surface functional layer 11, specifically on the side opposite to the audience of the surface functional layer 11. A plurality of Fresnel structures 121 arranged according to a set rule are arranged on the surface of one side of the Fresnel structure layer 12.

[0076] According to different application scenarios and manufacturing processes, the Fresnel structure 121 can adopt different structures. For example, each Fresnel structure 121 can form a concentric circle that is sequentially expanded along the radial direction; or each Fresnel structure 121 can also be a linear structure that extends along the horizontal direction of the projection screen and is arranged perpendicular to the horizontal direction.

[0077] like Figure 2 As shown, each Fresnel structure 121 includes an inclined surface x1 and a connecting surface x2 connected to each other. The inclined surface x1 is inclined relative to the surface functional layer 11, and the inclination angle of the inclined surface x1 is set according to the incident angle of the projection light, so as to reflect the outgoing light of the projection device toward the audience when it is incident on the reflective structure layer on the surface of the inclined surface. The connecting surface x2 is used to connect the inclined surface x1.

[0078] The reflective structure layer F at least covers the inclined surface x1 of each Fresnel structure 121 of the Fresnel structure layer 12. The inclined surface x1 of the Fresnel structure has a specific inclination angle, so that the reflective structure layer F covering its surface also has a corresponding inclination angle, thereby allowing the projection light to be incident on the reflective structure layer F on the surface of the Fresnel structure and be reflected by the reflective structure layer F toward the audience's position.

[0079] like Figure 2 As shown, the projection light L emitted by the projection device is incident from the side of the surface functional layer 11 into the projection screen, and is reflected by the reflective structure layer F on the surface of the Fresnel structure when it is incident on the Fresnel structure 121, thereby reflecting in the direction of the audience. The projection screen provided by the embodiment of the present invention is a reflective screen, and the film layers before the light is incident on the reflective structure layer F are all light-transmitting. Any at least one light-transmitting film layer of the projection screen may contain a low-valent oxide, thereby reducing the transmittance of the light-transmitting film layer to the visible light band, that is, the low-valent oxide has a certain absorption to the visible light band. Therefore, when displaying a black image, the incident ambient light can be absorbed to improve the black brightness of the projection screen.

[0080] Suboxides are incomplete oxides. In the embodiments of the present invention, metal suboxides can be used, and the transmittance to the visible light band can be changed by controlling the oxygen content of the metal suboxides. Metal suboxides are transition products of metals during the oxidation process. Metals are mostly opaque substances. From the metallic state to the oxide state after complete oxidation, the transmittance to the visible light band will gradually increase, and the absorptivity will gradually decrease. Finally, it will be completely oxidized into an oxide that is transparent to the visible light band. In the embodiments of the present invention, the oxide formed by the completely oxidized metal is called the metal complete oxide, and the oxide formed by the incompletely oxidized metal is called the metal suboxide.

[0081] The following is a detailed introduction to the changes in optical parameters during metal oxidation. Figure 3 A curve showing changes in optical parameters of a metal complete oxide provided by an embodiment of the present invention; Figure 4 The graph shows the variation of the optical parameters of the metal suboxide provided by the embodiment of the present invention.

[0082] Generally speaking, optical parameters include parameters that characterize various aspects of performance. The main parameters that need to be considered in projection screens are the refractive index n and the extinction coefficient k. Among them, the extinction coefficient k determines the absorption capacity of the incident visible light band. The larger the extinction coefficient, the stronger the absorption capacity. Figure 3 and Figure 4 It can be seen that the refractive index n of a metal complete oxide decreases with the increase of wavelength and then tends to be constant, and the extinction coefficient k decreases rapidly with the increase of wavelength, and its value in the visible light band is 0, that is, it has no light absorption in the visible light band. For metal low-valent oxides, the refractive index n tends to decrease first and then increase with the increase of wavelength, and the extinction coefficient k tends to decrease first, then increase, and then decrease with the increase of wavelength, and the value of the extinction coefficient k in the visible light band is above 0, so it has an absorption effect on the visible light band. Therefore, by adding a metal low-valent oxide to any one of the light-transmitting film layers in the projection screen, the film layer can have certain light absorption properties in the visible light band while being light-transmitting.

[0083] In specific implementation, metal suboxides can be produced by a reactive sputtering process with plasma luminescence control. In the sputtering chamber, the sputtering source is metal. In addition to using discharge gases such as argon, reactive gases such as oxygen are also needed. The plasma luminescence intensity is adjusted by controlling the flow rate of the reactive gas to form metal suboxides. There is a transition state in the process from the metallic state to the fully oxidized metal oxide, and metal suboxides can be formed in the transition zone.

[0084] Specifically, Figure 5 A curve showing the change of oxidation number with the flow rate of reactive gas in the reactive sputtering process of plasma luminescence control provided by an embodiment of the present invention; Figure 6 A curve showing the change of oxygen partial pressure with the flow rate of reactive gas in the reactive sputtering process controlled by plasma luminescence provided by an embodiment of the present invention; Figure 7 The curve of the extinction coefficient changing with the reactive gas flow rate in the reactive sputtering process of plasma luminescence control provided by the embodiment of the present invention. The sputtering source is metal, the reactive gas is oxygen, and the metal will be gradually oxidized during the sputtering process, gradually transforming from the metal state to the metal complete oxide state. Figure 5 to Figure 7 The solid line frame represents the metal low-valent oxide state, and the dotted line frame represents the metal complete oxide state.

[0085] like Figure 5 and Figure 6As shown in the figure, with the gradual increase of the reactive gas flow rate, the main component of the substance formed in the metal zone is metal, and the oxidation number and oxygen partial pressure tend to increase slowly; when it reaches the transition zone, the metal is partially oxidized, and the main component is metal low-valent oxide, and the oxidation number and oxygen partial pressure increase significantly; and when it reaches the oxide zone, the metal is completely oxidized into metal complete oxide, and the oxidation number and oxygen partial pressure show a trend of slowly increasing, and after the reactive gas flow rate increases to a certain extent, the oxidation number and oxygen partial pressure tend to be stable.

[0086] like Figure 7 As shown in the figure, with the gradual increase of the reactive gas flow rate, the main component of the substance formed in the metal zone is still metal, so the extinction coefficient is large, the light absorption is strong and the light transmittance is poor; with the gradual increase of the reactive gas flow rate, the metal is gradually oxidized, and when the metal is oxidized into a metal low-valent oxide in the transition zone, its extinction coefficient is greatly reduced, but it still has a certain light absorption and the light transmittance is increased; with the reactive gas flow rate increasing to a certain extent, the metal is completely oxidized to form a metal complete oxide, at which time the extinction coefficient is reduced to the minimum value and it no longer has light absorption.

[0087] It can be seen that by controlling the oxygen content of metal suboxides, their extinction coefficients can be changed, so that the metal suboxides have different degrees of absorption of visible light.

[0088] In some embodiments, the reflective structure layer F can have both wavelength selective reflectivity and absorption of incident light. The reflective structure layer F is designed to have a reflectivity of light emitted by the projection device greater than that of light in other wavelength bands, so that the reflective structure layer F can have a higher reflectivity for the wavelength band of the light emitted by the projection device, while the reflectivity for light in other wavelength bands is greatly reduced, thereby significantly improving the contrast of the projected image during projection display.

[0089] like Figure 2 As shown, the projection light L emitted by the projection device is incident from one side of the surface functional layer 11 into the inside of the projection screen, and is reflected by the reflective structure layer F on the surface of the Fresnel structure when incident on the Fresnel structure 121, thereby reflecting in the direction where the audience is located. At the same time, the ambient light C is incident from one side of the surface functional layer 11 into the inside of the projection screen. When the ambient light C is incident on the reflective structure layer F on the surface of the Fresnel structure, since the reflective structure layer F has a high reflectivity only for the wavelength band of the projection light and a low reflectivity for ambient light in other wavelength bands, the reflection of the ambient light can be greatly reduced, and the contrast of the projection light can be improved.

[0090] At the same time, the reflective structure layer F has a certain absorptivity to the incident light, and when displaying a black image, it can absorb the incident ambient light and improve the black brightness of the projection screen.

[0091] Specifically, the reflective structure layer F selectively reflects incident light by utilizing the principle of resonance. Figure 8 One of the structural schematic diagrams of the reflective structure layer provided in an embodiment of the present invention, Fig. 9 The second structural schematic diagram of the reflective structure layer provided in the embodiment of the present invention.

[0092] like Figure 8 and Fig. 9 As shown, the reflective structure layer F includes: a reflective layer 131 and at least one film layer group z located on the reflective layer 131 . The film layer groups z are stacked and each film layer group z includes: a semi-transparent layer 132 and a transparent medium layer 133 .

[0093] The reflective layer 131 has the function of reflecting light. The reflective layer 131 is located on the side away from the audience and does not need to transmit light. Therefore, it can be made of a material with reflective properties but no light-transmitting properties. In the embodiment of the present invention, the reflective layer 131 can be made of materials such as aluminum, aluminum alloy, silver or silver alloy. For example, the reflective layer 131 can be made of aluminum alloys such as Al and AlSi, or a laminated structure composed of silver alloys such as Ag and AgPaCu, which is not limited here. The reflective layer 131 can be made by sputtering, evaporation and other methods, which is not limited here.

[0094] For each film layer group z, the semi-transparent layer 132 is located on the side close to the surface functional layer 11, and the reflective layer 131 is located on the side of the semi-transparent layer 131 opposite to the surface functional layer 11, and there is a certain distance between the semi-transparent layer 132 and the reflective layer 131. The light-transmitting medium layer 133 is located between the semi-transparent layer 132 and the reflective layer 131.

[0095] In specific implementation, the reflective structure layer F can be set as follows: Figure 8 The single resonance structure shown in FIG. 1 is a resonance structure composed of a reflective layer 131, a semi-transparent layer 132 and a transparent medium layer 133; or the reflective structure layer F can also be set as follows Fig. 9 The double resonance structure shown is a resonance structure formed by the reflective layer 131, the semi-transparent layer 132 and the transparent medium layer 133, and another resonance structure is formed by the adjacent semi-transparent layer 132, the transparent medium layer 133 and the semi-transparent layer 132; by analogy, the reflective structure layer F can also include more than two resonance structures. The more resonance structures included in the reflective structure layer F, the more precise its wavelength selectivity is, and the cost will also increase accordingly. Therefore, it is necessary to strike a balance between performance and cost in specific implementation.

[0096] Specifically, the semi-transparent layer 132 in the reflective structure layer F has a semi-transparent and semi-reflective property, so that when the projection light is incident on the projection screen, the projection light can be incident on the resonance structure, and when the projection light oscillates and strengthens in the resonance structure, it can also be emitted from one side of the semi-transparent layer 132. In the embodiment of the present invention, the semi-transparent layer 132 can be a laminated structure formed by at least one metal selected from Al, Nb, Ag and Ti, etc., which is not limited here. The semi-transparent layer 132 can be manufactured by sputtering, evaporation and other methods, which are not limited here.

[0097] The thickness of the transparent medium layer 133 determines the cavity length of the resonant structure. Therefore, the product of the refractive index and thickness of the transparent medium layer 133 determines the wavelength of the light emitted from the resonant structure toward the audience and the wavelength that is extinguished inside the resonant structure. Therefore, when designing the resonant structure, it is necessary to select a dielectric material whose refractive index and thickness product satisfies the conditions for causing the projection light emitted by the projection device to resonate.

[0098] In an embodiment of the present invention, the projection light source can adopt a three-color laser light source device, which can emit red laser, green laser and blue laser. Then, by adjusting the refractive index and thickness of the material of the transparent medium layer, the resonance structure can simultaneously enhance the reflection of red laser, green laser and blue laser, while attenuating the reflection of light in other bands, thereby improving the contrast of the projection light.

[0099] Fig.10 The reflectivity curve of the reflective structure layer provided in the embodiment of the present invention to light of different wavelength bands. Fig.10 The position of the middle dashed line is the position of the peak wavelength of the three-color laser light emitted by the three-color laser light source device. Fig.10 It can be seen that the reflective structure layer F provided in the embodiment of the present invention can have a high reflectivity at the wavelengths of the red laser, green laser and blue laser emitted by the projection device, while the reflectivity in other bands is significantly reduced, which is beneficial to improving the contrast of the projection light.

[0100] According to simulation tests, when the thickness of the reflective layer 131 is greater than 50 nm, the thickness of the semi-transparent layer 132 is in the range of 2 nm to 20 nm, and the product of the thickness and the refractive index of the transparent medium layer 133 is in the range of 1200 to 1800, the effect is better.

[0101] In order to make the product of the refractive index and thickness of the transparent medium layer 133 satisfy the selective reflection of the projection light, the transparent medium layer 133 can usually be made of a transparent medium material, for example, a metal complete oxide such as TiO2, Nb2O5, ZrO2, Al2O3, ZnO2, SiO2, etc. However, these metal complete oxides are transparent to light in the visible light band. In order to make the reflective structure layer have both wavelength selective reflectivity and absorptivity, the transparent medium layer 133 in the reflective structure layer F can contain a low-valent oxide. As described above, the transparent medium layer 133 can be made of a metal low-valent oxide, or a metal low-valent oxide can be added to the material of the transparent medium layer 133, and its transparency can be reduced to a certain extent by controlling the oxygen content of the metal low-valent oxide.

[0102] In this way, the reflective structure layer F can have both wavelength selective reflectivity and certain light absorption in the visible light band, which can shield ambient light. There is no need to set a separate light absorption layer in the projection screen, which simplifies the structure of the projection screen and reduces production costs.

[0103] In some embodiments, the material of the light-transmitting medium layer 133 in the reflective structure layer F may all be low-valent oxides.

[0104] In some embodiments, the material of the light-transmitting medium layer 133 in the reflective structure layer F may include low-valent oxides and complete oxides. For example, the low-valent oxides and complete oxides may be layered.

[0105] In some embodiments, the light-transmitting dielectric layer 133 may include a first dielectric layer and a second dielectric layer stacked in layers; wherein the first dielectric layer may be made of a low-valent oxide, and the second dielectric layer may be made of a complete oxide; or, the first dielectric layer may be made of a complete oxide, and the second dielectric layer may be made of a low-valent oxide. The order of the low-valent oxide and the complete oxide is not limited.

[0106] Each film layer in the reflective structure layer F can be manufactured by a sputtering process. When the light-transmitting medium layer 133 is formed by sputtering, the metal undergoes oxidation reactions to varying degrees by controlling the flow rate of the reactive gas, i.e., oxygen. When the metal is partially oxidized, a metal low-valent oxide is formed, and when the metal is completely oxidized, a metal complete oxide is formed. The absorption capacity of the film layer formed by reactive sputtering to incident light decreases as the oxygen content increases. Therefore, in order to enable the light-transmitting medium layer 133 to achieve a suitable light absorption effect, the flow rate of the reactive gas needs to be finely controlled.

[0107] In a specific implementation, the metal suboxide in the light-transmitting medium layer may be Nb2O 5-x 、TiO 2-y or Ta2O 5-zIn one of the above, 0<x<5, 0<y<2, 0<z<5, x, y, z can be integers or decimals in the above range, and are not limited here. In addition to the above materials, other metal low-valent oxides can also be used, which are not listed here one by one.

[0108] Fig.11 A curve showing the change of film forming speed with the flow rate of reactive gas in the reactive sputtering process controlled by plasma luminescence provided in an embodiment of the present invention.

[0109] like Fig.11 As shown in the figure, with the gradual increase of the reactive gas flow rate, the main component of the film layer in the metal area is still metal, so the film formation speed is faster; with the gradual increase of the reactive gas flow rate, the metal is gradually oxidized, and the film formation speed decreases accordingly; with the reactive gas flow rate increasing to a certain extent, the metal is completely oxidized to form metal complete oxide, and the film formation speed further decreases.

[0110] from Fig.11 It can be seen that the film-forming speed of metal suboxides is faster than that of metal complete oxides. Therefore, if metal suboxides are used as the light-transmitting medium layer of the resonant structure, productivity can be improved, which is beneficial to reducing costs.

[0111] The embodiments of the present invention also provide several deformation structures of projection screens. Fig.12 The second structural schematic diagram of the projection screen provided in the embodiment of the present invention.

[0112] like Figure 2 and Fig.12 As shown, the projection screen further includes: an adhesive layer 14, which is located between the surface functional layer 11 and the Fresnel structure layer 12 and is used to bond the surface functional layer 11 to the Fresnel structure layer 12. The adhesive layer 14 can be made of an adhesive material such as epoxy resin, acrylic resin, silicone, etc., which is not limited here.

[0113] In some embodiments, Figure 2 As shown, the Fresnel structure 121 of the Fresnel structure layer 12 is located on the side opposite to the adhesive layer 14; the adhesive layer 14 is used to bond the surface functional layer 11 to the surface of the Fresnel structure layer 12 on the side opposite to the Fresnel structure 121. When the Fresnel structure is arranged on the side away from the adhesive layer 14, the semi-transparent layer in the reflective structure layer F needs to be arranged close to the Fresnel structure 121.

[0114] In some embodiments, Fig.12As shown, the Fresnel structure 121 of the Fresnel structure layer 12 is located on the side facing the adhesive layer 14; the adhesive layer 14 is used to bond the surface functional layer 11 and the reflective structure layer F on the Fresnel structure 121. When the Fresnel structure is arranged on the side close to the adhesive layer 14, the semi-transparent layer in the reflective structure layer F needs to be arranged away from the Fresnel structure 121. Figure 2 and Fig.12 The arrangement order of the film layers in the middle reflective structure layer F is opposite.

[0115] When the Fresnel structure is arranged on the side close to the adhesive layer 14, the adhesive layer 14 can play a role in protecting the reflective structure layer F. Since the Fresnel structure layer 12 is located on the side farthest from the audience and no light is incident on the Fresnel structure layer 12, the requirements on the light transmittance and damage specifications of the Fresnel structure layer 12 are reduced. It is no longer necessary to use expensive optical materials to make the Fresnel structure layer 12, and cheaper industrial materials can be used for production, thereby reducing production costs.

[0116] Fig.13 The third structural schematic diagram of the projection screen provided in the embodiment of the present invention.

[0117] In some embodiments, Fig.13 As shown, the surface functional layer 11 includes: a first substrate 111 and a diffusion material 112 .

[0118] The first substrate 111 serves as a substrate for the diffusion material 112 . The first substrate 111 is in contact with the adhesive layer 14 . The diffusion material 112 is located on a surface of the first substrate 111 opposite to the adhesive layer 14 .

[0119] The projection device in the embodiment of the present invention usually adopts a laser light source. The laser has a high collimation, so the divergence angle of the projection light is small. The light reflected by the projection screen has a high collimation, which also leads to a small viewing angle. By setting a diffusion material, the light can be diversified after passing through the surface functional layer, so that the light finally emitted by the projection screen has a certain divergence angle, which increases the viewing angle of the audience watching the projected image. In addition, the diffusion material is also conducive to eliminating laser speckle and optimizing the projection image.

[0120] The diffusion material 112 may be made of a resin material containing diffusion particles, and the diffusion particles may be, but are not limited to, silicon dioxide particles, aluminum oxide particles, titanium oxide particles, cerium oxide particles, zirconium oxide particles, tantalum oxide particles, zinc oxide particles, magnesium fluoride particles, etc. The diffusion material 112 may be made by various coating methods, which are not limited here.

[0121] The first substrate 111 may be made of, but is not limited to, PET, PEN, PC, PMMA, TAC, COP, TPU, PVC, PI, PA, PE, PP and other materials.

[0122] Fig.14 The fourth structural schematic diagram of the projection screen provided in the embodiment of the present invention.

[0123] In some embodiments, Fig.14 As shown, the surface functional layer 11 only includes a first substrate 111, and the first substrate 111 is in contact with the adhesive layer 14 and is bonded to the Fresnel structure layer 12 through the adhesive layer 14. The material of the first substrate 111 includes a diffusion material, so when the first substrate 111 is formed, the first substrate 111 can have a light diffusion ability and a certain haze. The first substrate 111 including the diffusion material can expand the viewing angle and reduce the reflection of light, thereby preventing the light from forming a clear image on the ceiling, having the effect of anti-ceiling reflection, and can enhance the viewing experience of the audience.

[0124] Fig.15 The fifth structural schematic diagram of the projection screen provided in the embodiment of the present invention.

[0125] In some embodiments, Fig.15 As shown, the surface functional layer 11 only includes a first substrate 111, which is in contact with the adhesive layer 14 and is bonded to the Fresnel structure layer 12 through the adhesive layer 14. The surface of the first substrate 111 on the opposite side of the adhesive layer 14 is an uneven surface. The uneven surface can be formed by sandblasting or alkali treatment of the surface of the first substrate 111, which is not limited here. The uneven surface of the first substrate 111 can play a certain role in light diffusion and atomization, thereby expanding the viewing angle and preventing ceiling reflection.

[0126] Fig.16 The sixth structural schematic diagram of the projection screen provided in the embodiment of the present invention.

[0127] In some embodiments, Fig.16 As shown, the projection screen may also include only the Fresnel structure layer 12 and the surface functional layer 11. The Fresnel structure 121 of the Fresnel structure layer 12 is arranged on the side facing the viewer, and the surface functional layer 11 is located on the surface of the reflective structure layer F on the opposite side to the Fresnel structure layer 12. In this case, the surface functional layer adopts the diffusion material 112 covering the reflective structure layer F. The diffusion material 112 can be formed on the surface of the reflective structure layer F by coating, spraying, etc. Fig.16 The projection screen structure shown can effectively reduce the thickness of the projection screen.

[0128] When using Fig.16In the projection screen structure shown, the semi-transmissive layer in the reflective structure layer F needs to be arranged on a side away from the Fresnel structure 121 . Figure 2 and Fig.16 The arrangement order of the film layers of the reflective structure layer F is opposite.

[0129] In specific implementation, Fig.16 As shown, the Fresnel structure layer 12 may include a second substrate 122 , the surface of the second substrate 122 facing the surface functional layer 11 and the surface opposite to the surface functional layer 11 are both flat surfaces, and the Fresnel structure 121 is located on the surface of one side of the second substrate 122 .

[0130] The second substrate 122 can be made of materials such as PET, which is not limited here. The Fresnel structure 121 can be made by using a mold having a Fresnel structure and a UV molding process using a UV curable resin. The Fresnel structure 121 can be formed by applying a UV curable resin to a mold having a Fresnel structure, and using the second substrate 122 to emboss and UV cure the UV curable resin.

[0131] Fig.17 The seventh structural schematic diagram of the projection screen provided in the embodiment of the present invention.

[0132] In some embodiments, Fig.17 As shown, the Fresnel structure layer 12 can also be an integrated structure, where one surface of the Fresnel structure layer 12 is the Fresnel structure 121, and the surface opposite to the Fresnel structure 121 is a flat surface. The integrated structure of the Fresnel structure layer can save the process of combining the substrate with the Fresnel structure, further simplifying the manufacturing process.

[0133] In a specific implementation, the integrally formed Fresnel structure layer 12 can be manufactured by thermoforming, and the Fresnel structure layer can be made of thermoplastic material, which is not limited here.

[0134] Based on the above-mentioned projection screen structure, in addition to adding low-valent oxides to the transparent medium layer 133 in the reflective structure layer F, low-valent oxides can also be added to any at least one of the transparent film layers in the surface functional layer 11 and the Fresnel structure layer 12 so that the film layer has a certain absorption effect on visible light. The embodiment of the present invention does not specifically limit the type and quantity of the selected transparent film layers.

[0135] Based on the same inventive concept, an embodiment of the present invention further provides a projection system, such as Figure 1 As shown, the projection system includes: a projection device 2 and a projection screen 1 located at the light emitting side of the projection device 2 .

[0136] Fig.18A schematic diagram of the structure of a projection device provided in an embodiment of the present invention.

[0137] like Fig.18 As shown, the projection device includes: a light source device 21, an illumination light path 22, a light modulation component 23 and a projection lens 24. The illumination light path 22 is located at the light exit side of the light source device 21, the light modulation component 23 is located at the light exit side of the illumination light path 22, and the projection lens 24 is located at the light exit side of the light modulation component 23.

[0138] The light source device 21 may be a laser light source device, which may be a monochromatic laser or a laser that can emit lasers of multiple colors or a plurality of lasers that emit lasers of different colors.

[0139] In the embodiment of the present invention, the light source device may adopt a three-color laser light source device, which may be a laser emitting three primary color lasers, such as an MCL laser, etc.; or may include a red laser, a green laser, and a blue laser emitting three primary color lasers respectively. The use of a three-color laser light source device is conducive to improving the color gamut of the projected image, has better color expression, and can accurately reproduce the input image.

[0140] The illumination optical path 22 is located at the light output side of the light source device 21. The illumination optical path 22 collimates the output light of the light source device 21 and allows the output light of the light source device 21 to be incident on the light modulation component 23 at a suitable angle. The illumination optical path 22 may include multiple lenses or lens groups, which are not limited here.

[0141] The light modulation component 23 is used to modulate the incident light. In a specific implementation, the light modulation component 23 can be a digital micromirror (DMD). The light modulation component 23 receives the incident light after total reflection by the total reflection prism P, modulates the incident light, and reflects the modulated light. After passing through the illumination light path 22, the light beam meets the illumination size and incident angle required by the DMD. The surface of the DMD includes many tiny reflectors, each of which can be driven to deflect individually. By controlling the deflection angle of the DMD, the brightness of the light incident on the projection lens 24 is controlled.

[0142] The projection lens 24 is used to image the output light of the light modulation component 23 , and the image is projected after being imaged by the projection lens 24 .

[0143] In the embodiment of the present invention, the projection device 2 can be an ultra-short-throw projection device, that is, the projection lens 24 in the projection device is an ultra-short-throw projection lens. The use of the ultra-short-throw projection device can greatly shorten the distance between the projection device 2 and the projection screen 1, and can achieve large-size image display while shortening the projection distance.

[0144] The projection screen 1 is located on the light-emitting side of the projection lens in the projection device. The projection screen 1 includes a surface functional layer, a Fresnel structure layer, and a reflective structure layer located on each Fresnel structure in the Fresnel structure layer. Any at least one of the light-transmitting film layers in the projection screen 1 contains a low-valent oxide, which can reduce the transmittance in the visible light band, so that there is no need to set a separate absorption layer in the projection screen, which reduces costs and simplifies the structure. When displaying a black image, it can absorb incident ambient light and improve the black brightness of the projection screen.

[0145] Although the preferred embodiments of the present invention have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0146] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A projection screen, characterized in that: include: Surface functional layer; A Fresnel structure layer is located on one side of the surface functional layer; a surface of one side of the Fresnel structure layer has a plurality of Fresnel structures, and the Fresnel structure includes an inclined surface that is inclined relative to the plane where the surface functional layer is located; and A reflective structure layer at least covers the inclined surfaces of the Fresnel structures of the Fresnel structure layer; Wherein, any light-transmitting film layer in the projection screen contains low-valent oxides; the low-valent oxides are used to reduce the transmittance in the visible light band.

2. The projection screen according to claim 1, characterized in that The subvalent oxide is a metal subvalent oxide; The absorption capacity of the low-valent oxide to the visible light band decreases with the increase of oxygen content.

3. The projection screen according to claim 1, characterized in that: The reflectivity of the reflective structure layer to the outgoing light of the projection device is greater than the reflectivity of the light in other wavebands.

4. The projection screen according to claim 3, characterized in that: The reflective structure layer comprises: Reflective layer; and At least one film layer group is located on a side of the reflective layer facing the surface functional layer; the film layer groups are stacked; Wherein, the film layer group comprises: a semi-transmissive layer, located on a side close to the surface functional layer; and The light-transmitting medium layer is located between the semi-transmitting layer and the reflective layer; the product of the refractive index and the thickness of the light-transmitting medium layer satisfies the condition for causing the outgoing light of the projection device to resonate.

5. The projection screen according to claim 4, characterized in that: The light-transmitting medium layer includes the low-valent oxide.

6. The projection screen according to claim 4, characterized in that: The light-transmitting medium layer comprises the low-valent oxide and the complete oxide.

7. The projection screen according to claim 6, characterized in that The light-transmitting dielectric layer comprises a first dielectric layer and a second dielectric layer which are stacked; wherein the first dielectric layer is made of low-valent oxide and the second dielectric layer is made of complete oxide; or, the first dielectric layer is made of complete oxide and the second dielectric layer is made of low-valent oxide.

8. The projection screen according to claim 5 or 6, characterized in that: The low-valent oxide is Nb2O 5-x 、TiO 2-y or Ta2O 5-z One of; Among them, 0<x<5, 0<y<2, 0<z<5.

9. The projection screen according to claim 4, characterized in that: The semi-transparent layer is a laminated structure formed by at least one metal selected from aluminum, niobium, silver and titanium; the thickness of the semi-transparent layer is 2nm to 20nm; The material of the reflective layer is aluminum, aluminum alloy, silver or silver alloy; the thickness of the reflective layer is greater than 50nm; The product of the thickness and the refractive index of the light-transmitting medium layer is 1200-1800.

10. The projection screen according to claim 1, wherein: The projection screen further comprises: an adhesive layer located between the surface functional layer and the Fresnel structure layer; The Fresnel structure of the Fresnel structure layer is located on the side opposite to the surface functional layer; the adhesive layer is used to bond the surface functional layer to the surface of the Fresnel structure layer on the side opposite to the Fresnel structure; Alternatively, the Fresnel structure of the Fresnel structure layer is located on a side facing the surface functional layer; and the adhesive layer is used to bond the surface functional layer and the reflective structure layer on the Fresnel structure to each other.

11. The projection screen according to claim 10, characterized in that The surface functional layer comprises: A first substrate in contact with the adhesive layer; and a diffusion material, located on a surface of the first substrate opposite to the adhesive layer; Alternatively, the surface functional layer comprises: A first substrate in contact with the adhesive layer; the first substrate contains a diffusion material; Alternatively, the surface functional layer comprises: The first substrate is in contact with the adhesive layer; the surface of the first substrate opposite to the adhesive layer is an uneven surface.

12. The projection screen according to claim 1, wherein: The surface functional layer is located on the surface of the reflective structure layer on the side opposite to the Fresnel structure; The surface functional layer is a diffusion material covering the reflective structure layer.

13. A projection system, characterized in that: include: A projection device, used for emitting projection light; and A projection screen, located at the light-emitting side of the projection device, wherein the projection screen is the projection screen according to any one of claims 1 to 12; Wherein, the projection device is an ultra-short-throw laser projection device; the projection device comprises: A three-color laser light source device, used for emitting three-primary-color lasers; a light modulation component, located at the light output side of the three-color laser light source device, and used to modulate the output laser light of the three-color laser light source device; and The projection lens is located at the light-emitting side of the light modulation component.

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