projection screen

Abstract

A projection screen includes a substrate, a lower surface layer, an intermediate layer, and an upper surface layer. The lower surface layer is located on the substrate. The material of the lower surface layer includes acrylate, color paste or carbon black, and first-type particles. The intermediate layer is located on the substrate. The material of the intermediate layer includes acrylate and second-type particles. The upper surface layer is located on the substrate. The material of the upper surface layer includes acrylate and third-type particles. The lower surface layer, the intermediate layer, and the upper surface layer are stacked on the substrate in sequence. The materials included in the first-type particles, the second-type particles, and the third-type particles do not overlap with each other. The projection screen of the present invention can effectively suppress laser spot.

Description

Technical Field

[0001] The present invention relates to a projection screen, and more particularly to a projection screen capable of suppressing the light spot phenomenon of a laser projector. Background Art

[0002] There are many types of digital light source projectors on the market today, ranging from those that utilize white light bulbs with a color wheel to those that use three-color LEDs. However, the light source itself is typically diffuse, making it difficult to focus the intensity on the projection screen.

[0003] Laser light sources offer advantages such as high purity, high-power illumination, and high color saturation. Currently, many manufacturers are replacing light-emitting diodes with lasers as projection light sources. However, due to the coherent interference of laser light sources, when a laser projector projects an image onto a screen, the laser spot is noticeable, resulting in reduced image quality.

[0004] The "Background" section is intended only to facilitate understanding of the present invention. Therefore, the information disclosed in this section may contain information that is not generally known to those skilled in the art. The information disclosed in this section does not imply that the information or the problems to be solved by one or more embodiments of the present invention were known or understood by those skilled in the art prior to the filing of this application. Summary of the Invention

[0005] The present invention provides a projection screen which can effectively suppress the problem of laser spot.

[0006] One embodiment of the present invention provides a projection screen comprising a substrate, a lower surface layer, an intermediate layer, and an upper surface layer. The lower surface layer is located on the substrate. The lower surface layer is made of a material including acrylate, color paste or carbon black, and first-type particles. The intermediate layer is located on the substrate. The intermediate layer is made of a material including acrylate and second-type particles. The upper surface layer is located on the substrate. The upper surface layer is made of a material including acrylate and third-type particles. The lower surface layer, intermediate layer, and upper surface layer are stacked in sequence on the substrate. The materials comprising the first-type particles, the second-type particles, and the third-type particles do not overlap.

[0007] Based on the above, in one embodiment of the present invention, due to the selection of materials for each film layer of the projection screen, the ratio of each material component, and the requirement that the materials included in the first-type particles, second-type particles, and third-type particles do not overlap with each other, the incident light is refracted and diffused when it enters the projection screen. Therefore, the original coherence of the incident light (laser) is destroyed when the incident light enters the surface, effectively suppressing the problem of laser spot.

[0008] In order to make the above features and advantages of the present invention more clearly understood, embodiments are given below with reference to the accompanying drawings for detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1A is a schematic diagram of a projection screen according to an embodiment of the present invention.

[0010] Figure 1B yes Figure 1A Schematic side view of the projection screen.

[0011] Figure 2 4 is a schematic diagram of a lower surface layer in a projection screen according to another embodiment of the present invention. DETAILED DESCRIPTION

[0012] The foregoing and other technical aspects, features, and benefits of the present invention will be more clearly understood in the following detailed description of a preferred embodiment with reference to the accompanying drawings. Directional terms such as up, down, left, right, front, and back, used in the following embodiments, are merely references to the accompanying drawings. Therefore, the directional terms used are for illustrative purposes only and are not intended to limit the present invention.

[0013] Figure 1A is a schematic diagram of a projection screen according to an embodiment of the present invention. Figure 1B yes Figure 1A A side view of the projection screen. Figure 1A and Figure 1B One embodiment of the present invention provides a projection screen 10 comprising a substrate 100, a lower surface layer 200, an intermediate layer 300, and an upper surface layer 400. The substrate 100 may be, for example, a plastic substrate, a glass substrate, a cloth screen, a light-transmitting diffuser, or other suitable substrates. The lower surface layer 200, the intermediate layer 300, and the upper surface layer 400 are all located on the substrate 100. The lower surface layer 200, the intermediate layer 300, and the upper surface layer 400 are stacked sequentially on the substrate 100. The upper surface layer 400 is defined as the layer that incident light L first contacts among the various layers of the projection screen 10.

[0014] In this embodiment, the lower surface layer 200 is used to enhance the contrast of the projected image. Therefore, it is preferably selected from a material that enhances contrast, and the selected material is related to the material of the substrate 100. The intermediate layer 300 is used to disrupt the coherence of the incident light L and is preferably composed of a combination of materials or materials with different particle sizes and refractive indices. The upper surface layer 400 is used to enhance diffusion, thereby increasing the half-viewing angle.

[0015] In this embodiment, the material of the lower surface layer 200 includes acrylate 210, first-type particles 220, and colorant or carbon black 230, wherein the first-type particles 220 and the colorant or carbon black 230 are mixed in the acrylate 210. The material of the intermediate layer 300 includes acrylate 310 and second-type particles 320, wherein the second-type particles 320 are mixed in the acrylate 310. The material of the upper surface layer 400 includes acrylate 410 and third-type particles 420, wherein the third-type particles 420 are mixed in the acrylate 410. The materials of the first-type particles 230, the second-type particles 320, and the third-type particles 420 are not repeated. That is, the material type used for the first-type particles 220 is different from the material type used for the second-type particles 320 and the third-type particles 420. Similarly, the material type used for the second-type particles 320 is different from the material type used for the first-type particles 220 and the third-type particles 420, and the material type used for the third-type particles 420 is different from the material type used for the first-type particles 220 and the second-type particles 320. The acrylate 210 of the lower surface layer 200, the acrylate 310 of the intermediate layer 300, and the acrylate 410 of the upper surface layer 400 are made of the same material. However, because each layer is separately formulated, the content of acrylate 210, acrylate 310, and acrylate 410 in each layer varies, but this is not limiting. In one embodiment, the content of acrylate 210, acrylate 310, and acrylate 410 in each layer can be the same.

[0016] In this embodiment, the first type of particles 220 include first particles 221 and second particles 222. The first particles 221 and the second particles 222 are two of the following: silicone, polymethylmethacrylate (PMMA), polybutylmethylmethacrylate (PBMA), polystyrene (PS), silicon dioxide (SiO2), calcium carbonate (CaCO3), hollow glass beads, aluminum oxide (Al2O3), potassium titanate, barium sulfate, titanium dioxide (TiO2), porous minerals, or zirconium oxide. Specifically, the materials used for the first particles 221 and the second particles 222 are two of the above materials, and the material of the first particles 221 is different from the material of the second particles 222.

[0017] In this embodiment, the density of the material of the lower surface layer 200, the acrylate 210, the color paste or carbon black 230, the first particles 221, and the second particles 222 are respectively within a range of 45 to 60 g / cm 3 , 0.3 to 1 g / cm3 , 6 to 15g / cm 3 , 9 to 24g / cm 3 within the range.

[0018] In this embodiment, among the materials of the lower surface layer 200 , the particle sizes of the color paste or carbon black 230 , the first particles 221 , and the second particles 222 fall within the ranges of 0.02 to 0.1 μm, 1 to 4 μm, and 2 to 5 μm, respectively.

[0019] In this embodiment, among the materials of the lower surface layer 200 , the refractive indices of the acrylate 210 , the first particles 221 , and the second particles 222 fall within the ranges of 1.47 to 1.54, 1.55 to 1.61, and 1.43 to 1.49, respectively.

[0020] In this embodiment, the second-type particles 320 include third particles 321, fourth particles 322, and fifth particles 323. The third particles 321, fourth particles 322, and fifth particles 323 are three of silicone, polymethyl methacrylate, poly(n-butyl methyl methacrylate), polystyrene, silicon dioxide, calcium carbonate, hollow glass beads, aluminum oxide, potassium titanate, barium sulfate, titanium dioxide, porous minerals, zirconium oxide, or carbon black. In other words, the materials used for the third particles 321, fourth particles 322, and fifth particles 323 are three of the aforementioned materials, and the materials used for the third particles 321, fourth particles 322, and fifth particles 323 are all different. The materials used for the third particles 321, fourth particles 322, and fifth particles 323 of the second-type particles 320 are all different from the materials used for the first particles 221 and second particles 222 of the first-type particles 220.

[0021] In this embodiment, among the materials of the intermediate layer 300, the densities of the acrylate 310, the third particles 321, the fourth particles 322, and the fifth particles 323 are respectively within a range of 50 to 58 g / cm 3 , 13 to 18 g / cm 3 , 10 to 15 g / cm 3 , 4 to 9 g / cm 3 within the range.

[0022] In this embodiment, in the material of the intermediate layer 300 , the particle sizes of the third particles 321 , the fourth particles 322 , and the fifth particles 323 fall within the ranges of 1 to 3 microns, 5 to 9 microns, and 8 to 12 microns, respectively.

[0023] In this embodiment, among the materials of the intermediate layer 300 , the refractive indices of the acrylate 310 , the third particles 321 , the fourth particles 322 , and the fifth particles 323 are respectively within the ranges of 1.47 to 1.54, 1.54 to 1.60, 1.49 to 1.55, and 1.43 to 1.45.

[0024] In this embodiment, the second-type particles 320 are made of a porous material and have the largest particle size among the materials included in the lower surface layer 200, the intermediate layer 300, and the upper surface layer 400. For example, the fifth particles 323 are made of a porous material and have the largest particle size among the materials included in the lower surface layer 200, the intermediate layer 300, and the upper surface layer 400. The porous material selected for the fifth particles 323 has surface properties that help improve the coherence of the incident light L.

[0025] In this embodiment, the third type of particles 420 include sixth particles 421 and seventh particles 422. The sixth and seventh particles 421 and 422 are selected from two of silicone, polymethyl methacrylate, poly(n-butyl methyl methacrylate), polystyrene, silicon dioxide, calcium carbonate, hollow glass beads, aluminum oxide, potassium titanate, barium sulfate, titanium dioxide, porous minerals, zirconium oxide, or carbon black. In other words, the materials used for the sixth and seventh particles 421 and 422 are respectively two of the aforementioned materials, and the material of the sixth particle 421 is different from the material of the seventh particle 422. Furthermore, the materials used for the sixth and seventh particles 421 and 422 of the third type of particles 420 are different from the materials used for the first and second particles 221 and 222 of the first type of particles 220, and from the materials used for the third, fourth, and fifth particles 321, 322, and 323 of the second type of particles 320.

[0026] In this embodiment, the density of the material of the upper surface layer 400, the density of the acrylate 410, the sixth particles 421, and the seventh particles 422 are respectively within a range of 55 to 65 g / cm 3 , 6 to 15g / cm 3 , 14 to 20 g / cm 3 within the range.

[0027] In this embodiment, in the material of the upper surface layer 400 , the particle sizes of the sixth particles 421 and the seventh particles 422 fall within the ranges of 4 to 8 microns and 6 to 12 microns, respectively.

[0028] In this embodiment, among the materials of the upper surface layer 400 , the refractive indices of the acrylate 410 , the sixth particles 421 , and the seventh particles 422 fall within the ranges of 1.51 to 1.60, 1.49 to 1.55, and 1.57 to 1.61, respectively.

[0029] Figure 21 is a schematic diagram of the lower surface layer of the projection screen according to another embodiment of the present invention. Figure 2 In this embodiment, the substrate 100 has a plurality of microstructures 110 on the surface facing the lower surface layer 200. The microstructures 110 may be cylindrical prism microstructures, but the present invention is not limited thereto. In this embodiment, the lower surface layer 200, the intermediate layer 300, and the upper surface layer 400 are sequentially stacked on the surface of the substrate 100 having the microstructures 110. The presence of the microstructures 110 on the surface of the substrate 100 helps reduce the spot contrast of the incident light L, for example, to less than 10%.

[0030] In summary, in one embodiment of the present invention, due to the selection of materials for each film layer of the projection screen, the proportions of the various material components, and the requirement that the materials included in the first-type particles 220, the second-type particles 320, and the third-type particles 420 do not overlap with each other, the incident light is refracted and diffused when it enters the projection screen. Therefore, the original coherence of the incident light (laser) is destroyed when the incident light enters the surface, effectively suppressing the problem of laser spot.

[0031] Specifically, the projection screen of the embodiment of the present invention can achieve the following effects and advantages:

[0032] 1. As shown in Table 1 below, in addition to effectively suppressing the laser spot phenomenon, the projection screen of the embodiment of the present invention still maintains the original surface brightness with high transmittance.

[0033] Table 1

[0034]

[0035] 2. Compared to various projection screens available on the market, the projection screen of the embodiment of the present invention can maintain its original hue and will not cause color deviation problems due to the coating.

[0036] As shown in Table 2 below, before the film was applied, the original half-viewing angle luminance of the projection screen (the viewing angle at which the luminance is half that of the positive 0-degree angle) was 70 degrees. However, the luminance of the projection screen of the embodiment of the present invention at a viewing angle of 80 degrees was still higher than the original half-viewing angle luminance of the projection screen before the film was applied.

[0037] Table 2

[0038] Brightness before film layer is set Set the brightness of each film layer Positive 0 degrees 269 263(97.7％) 60 degrees 181(67.3％) 256(95.2％) 80 degrees 127(47.2％) 240(89.2％)

[0039] After applying the various film layers, the projection screen of the present invention achieved a spot contrast ratio of 5.1% for white images, 9.8% for red images, 6.8% for green images, and 7.7% for blue images, showing spot contrast ratios of all single colors below 10%. Spot contrast is defined as Cs = σ / I, where σ is the standard deviation of image intensity (grayscale) and I is the mean image intensity (grayscale).

[0040] 5. Using three-color laser projection, before the film is applied, the spot contrast value of the projection screen is 15.87%. However, the spot contrast value of the projection screen of the embodiment of the present invention is 8%, indicating a decrease of approximately 50%, effectively suppressing laser speckle.

[0041] 6. When three-color lasers were projected onto a substrate with a prismatic microstructure, the spot contrast ratio of the projection screen without the film was 11.78. However, the spot contrast ratio of the projection screen of the embodiment of the present invention was 6.87%, indicating a better effect in suppressing laser speckle.

[0042] The above description is only a preferred embodiment of the present invention, and it cannot be used to limit the scope of implementation of the present invention. That is, simple equivalent changes and modifications made according to the claims and the description of the invention are still within the scope of the patent of the present invention. In addition, any embodiment or claim of the present invention does not need to achieve all the purposes, advantages or features disclosed by the present invention. In addition, the abstract and title are only used to assist in searching patent documents and are not used to limit the scope of rights of the present invention. In addition, the terms "first", "second", etc. mentioned in this specification or claims are only used to name the name of the element or to distinguish different embodiments or scopes, and are not used to limit the upper or lower limit of the number of elements.

[0043] Description of Reference Numerals

[0044] 10: Projection screen

[0045] 100: base material

[0046] 110: Microstructure

[0047] 200: lower surface

[0048] 210, 310, 410: Acrylate

[0049] 220: Type I particle

[0050] 221: First Particle

[0051] 222: Second Particle

[0052] 230: Color paste or carbon black

[0053] 300: Intermediary layer

[0054] 320: Type II particles

[0055] 321: The Third Particle

[0056] 322: The Fourth Particle

[0057] 323: The Fifth Particle

[0058] 400: Upper surface

[0059] 420: Type III particles

[0060] 421: The Sixth Particle

[0061] 422: The Seventh Particle

[0062] L: incident light.

Claims

1. A projection screen, characterized in that: The projection screen includes a substrate, a lower surface layer, an intermediate layer and an upper surface layer, wherein The lower surface layer is located on the substrate, and the material of the lower surface layer includes acrylic ester, color paste or carbon black, and first type particles; The intermediary layer is located on the substrate, and the material of the intermediary layer includes the acrylate and the second type of particles; and The upper surface layer is located on the substrate, and the material of the upper surface layer includes the acrylic ester and the third type particles. The lower surface layer, the intermediate layer, and the upper surface layer are sequentially stacked on the substrate, and the materials included in the first type of particles, the second type of particles, and the third type of particles do not overlap with each other.

2. The projection screen according to claim 1, wherein: The first type of particles include first particles and second particles, and the first particles and the second particles are two of silicone, polymethyl methacrylate, polybutyl methyl methacrylate, polystyrene, silica, calcium carbonate, hollow glass beads, alumina, potassium titanate, barium sulfate, titanium dioxide, porous minerals or zirconium oxide.

3. The projection screen according to claim 2, wherein: In the material of the lower surface layer, the density of the acrylic ester, the color paste or the carbon black, the first particles, and the second particles are respectively within a range of 45 to 60 g / cm 3 , 0.3 to 1 g / cm 3 , 6 to 15g / cm 3 , 9 to 24g / cm 3 within the range.

4. The projection screen according to claim 2, wherein: In the material of the lower surface layer, the particle sizes of the color paste or the carbon black, the first particles, and the second particles fall within the ranges of 0.02 to 0.1 microns, 1 to 4 microns, and 2 to 5 microns, respectively.

5. The projection screen according to claim 2, wherein: Among the materials of the lower surface layer, the refractive indices of the acrylate, the first particles, and the second particles are respectively within the ranges of 1.47 to 1.54, 1.55 to 1.61, and 1.43 to 1.

49.

6. The projection screen according to claim 1, wherein: The second type of particles include third particles, fourth particles, and fifth particles, wherein the third particles, the fourth particles, and the fifth particles are three of silicone, polymethyl methacrylate, poly(n-butyl methyl methacrylate), polystyrene, silica, calcium carbonate, hollow glass beads, alumina, potassium titanate, barium sulfate, titanium dioxide, porous minerals, zirconium oxide, or carbon black.

7. The projection screen according to claim 6, wherein: In the material of the intermediate layer, the density of the acrylate, the third particle, the fourth particle, and the fifth particle falls within a range of 50 to 58 g / cm 3 , 13 to 18 g / cm 3 , 10 to 15 g / cm 3 , 4 to 9 g / cm 3 within the range.

8. The projection screen according to claim 6, wherein: In the material of the intermediate layer, the particle sizes of the third particles, the fourth particles, and the fifth particles fall within the ranges of 1 to 3 microns, 5 to 9 microns, and 8 to 12 microns, respectively.

9. The projection screen according to claim 6, wherein: Among the materials of the intermediary layer, the refractive indices of the acrylate, the third particles, the fourth particles, and the fifth particles are respectively within the ranges of 1.47 to 1.54, 1.54 to 1.60, 1.49 to 1.55, and 1.43 to 1.

45.

10. The projection screen according to claim 6, wherein: The fifth particles are made of a porous material and have the largest particle size among the materials included in the lower surface layer, the intermediate layer, and the upper surface layer.

11. The projection screen according to claim 1, wherein: The second type of particles are made of a porous material and have the largest particle size among the materials included in the lower surface layer, the intermediate layer, and the upper surface layer.

12. The projection screen according to claim 1, wherein: The third type of particles include sixth particles and seventh particles, and the sixth particles and the seventh particles are two of silicone, polymethyl methacrylate, polybutyl methyl methacrylate, polystyrene, silica, calcium carbonate, hollow glass beads, alumina, potassium titanate, barium sulfate, titanium dioxide, porous minerals, zirconium oxide or carbon black.

13. The projection screen according to claim 12, wherein: In the material of the upper surface layer, the density of the acrylic ester, the sixth particle, and the seventh particle is respectively within a range of 55 to 65 g / cm 3 , 6 to 15g / cm 3 , 14 to 20 g / cm 3 within the range.

14. The projection screen according to claim 12, wherein: In the material of the upper surface layer, the particle sizes of the sixth particles and the seventh particles fall within the ranges of 4 to 8 microns and 6 to 12 microns, respectively.

15. The projection screen according to claim 12, wherein: Among the materials of the upper surface layer, the refractive indices of the acrylic ester, the sixth particles, and the seventh particles are respectively within the ranges of 1.51 to 1.60, 1.49 to 1.55, and 1.57 to 1.

61.

16. The projection screen according to claim 1, wherein: The substrate has a plurality of microstructures on a surface facing the lower surface layer.

Images