Optical films, display modules, and display screens

Abstract

To provide an optical film for generating better collimate light and further improving performance of a display module, and to provide the display module, and a display screen.SOLUTION: The present invention pertains to an optical film, a display module, and a display screen, and the optical film includes a film body, multiple fine structures, and an opaque layer. The fine structures are disposed in one side of the film body, and is in projecting arc-shaped structure. The opaque layer is fixed to the film body, is set to the other side of the film body in a side opposite to the fine structures, and includes multiple openings. In this case, the center points of the openings overlap with the center points of the fine structures on a projection surface, the quotients obtained by dividing the equivalent diameters of the openings by the equivalent diameters of the fine structures are 0.3 or smaller, the quotients obtained by dividing the equivalent diameters of the fine structures by the thickness of the film body are 1.3 or smaller and are 0.7 or larger, and the opaque layer is orientated toward a light source.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an optical film for use in a display module or a microprojection system.

Background Art

[0002] Optical modules are widely used in many products such as displays, optical fiber communications, and medical devices. Among them, display modules are widely used in liquid crystal displays (LCDs), and their main function is to provide a uniform light source for displaying clear images.

[0003] Conventional display modules mainly use tubes or LEDs as light sources, and combine with other optical components (such as diffuser plates, light guide plates, reflectors, etc.) to adjust the light source and achieve a uniform brightness effect. Such a design of display modules usually includes a plurality of complex optical components, so the manufacturing process increases, the cost rises, and the difficulty of assembly also increases.

Summary of the Invention

Problems to be Solved by the Invention

[0004] To solve these problems, some advanced display module designs adopt micro-structuring technology. This technology can design multiple optical functions, such as reflection, refraction, diffusion, etc. on a single optical component, thereby achieving the purpose of controlling the optical path and improving the uniformity of brightness.

[0005] However, while this type of microstructure design is theoretically possible, it faces many challenges in actual manufacturing. For example, manufacturing microstructures requires precise lithography techniques, which are costly and have high technical thresholds. On the other hand, existing microstructure designs often fail to achieve optimal optical effects because their ability to control optical paths is still limited. In particular, when dealing with high-brightness or wide-viewing-angle applications, the effects are often not as expected.

[0006] In summary, while existing display module designs have made some progress, many problems still need to be addressed. For example, the cost and complexity of existing designs are still high, and optical performance still has room for improvement. Therefore, there is still a great demand for new display module design and manufacturing technologies. [Means for solving the problem]

[0007] Taking the above issues into consideration, this patent proposes an optical film that uses a combination of microstructured lenses and apertures in its design. This can generate better collimated light and further improve the performance of display modules. The specific technical means are as follows:

[0008] An optical film suitable as a component of an optical device including a light source comprises a film body, a plurality of microstructures, and an opaque layer. These microstructures are located on one side of the film body and are protruding arc-shaped structures. The opaque layer is fixed to the film body and is set on the other side of the film body opposite to the microstructures, and this opaque layer contains a plurality of openings. Here, the center points of the openings coincide with the center points of the microstructures on the projection plane. Here, the equivalent diameter of the openings divided by the equivalent diameter of the microstructures is 0.3 or less, and the equivalent diameter of the microstructures divided by the thickness of the film body is 1.3 or less and 0.7 or more. Here, the opaque layer is oriented toward the light source.

[0009] The optical film described above is characterized by the uniform arrangement of its microstructure and apertures across the film itself.

[0010] The optical film described above is characterized by the arrangement of its microstructure and apertures in a patterned configuration.

[0011] The optical film described above is characterized by its honeycomb-pattern arrangement of microstructures and apertures.

[0012] The optical film described above is characterized by the random arrangement of microstructures and apertures on the film itself.

[0013] A key feature of the optical film described above is that its microstructures intersect with each other on the film itself.

[0014] A key feature of the optical film described above is that the opaque layer is composed of a light-absorbing material.

[0015] The optical films described above are characterized by having a film body made of polycarbonate (PC), polymethyl methacrylate (PMMA), polyethylene terephthalate (PET), or glass, and an opaque layer made of nickel, silver, gold, aluminum, titanium dioxide, or silicon dioxide.

[0016] A key feature of the optical film described above is that the opaque layer is made of a reflective material.

[0017] The present invention also provides a display module characterized by comprising at least one optical film and a plurality of light sources. The light sources are positioned beneath the optical film. It is characterized in that the side of the optical film having an opaque layer is oriented toward the light source.

[0018] The display module described above is further characterized by including at least one diffusion layer positioned between the optical film and the light source.

[0019] In the above display module, the diffusion layer is fixed to the lower side of the optical film.

[0020] The above display module further includes a liquid crystal panel disposed on the optical film.

[0021] The above display module further includes a polarizing beam splitter and a spatial light modulator. The polarizing beam splitter is disposed on the optical film. Light emitted from a light source is reflected by the polarizing beam splitter to the spatial light modulator.

[0022] The present invention also provides a display screen, which includes at least one of the display module and the above optical film. The optical film is fixed to the display module, and the side of the optical film having the opaque layer is oriented toward the display module.

Brief Description of the Drawings

[0023] [Figure 1] This patent shows the optical film. [Figure 2] It shows a schematic diagram of the optical film and the light source. [Figure 3] It shows the arrangement of the microstructure and the openings. [Figure 4] It shows the arrangement of the microstructure and the openings. [Figure 5] It shows the honeycomb arrangement of the microstructure and the openings. [Figure 6] It shows the honeycomb arrangement of the microstructure and the openings. [Figure 7] It shows the random arrangement of the microstructure and the openings. [Figure 8] It shows the random arrangement of the microstructure and the openings. [Figure 9] It shows the arrangement and the cross arrangement of the microstructure. [Figure 10]This shows the arrangement and cross-configuration of the microstructure. [Figure 11] This shows the arrangement and cross-configuration of the microstructure. [Figure 12] This shows the honeycomb and cross-shaped arrangements of the microstructure. [Figure 13] This shows the honeycomb and cross-shaped arrangements of the microstructure. [Figure 14] This shows the honeycomb and cross-shaped arrangements of the microstructure. [Figure 15] This document describes a method for manufacturing an optical film according to the present invention. [Figure 16] This document describes a method for manufacturing an optical film according to the present invention. [Figure 17] This document describes a method for manufacturing an optical film according to the present invention. [Figure 18] This document describes a method for manufacturing an optical film according to the present invention. [Figure 19] This document describes a method for manufacturing an optical film according to the present invention. [Figure 20] This document describes a method for manufacturing an optical film according to the present invention. [Figure 21] This document describes a method for manufacturing an optical film according to the present invention. [Figure 22] This document describes a method for manufacturing an optical film according to the present invention. [Figure 23] This document describes a method for manufacturing an optical film according to the present invention. [Figure 24] This document describes a method for manufacturing an optical film according to the present invention. [Figure 25] This document describes a method for manufacturing an optical film according to the present invention. [Figure 26] This document describes a method for manufacturing an optical film according to the present invention. [Figure 27] This document describes a method for manufacturing an optical film according to the present invention. [Figure 28] This document describes a method for manufacturing an optical film according to the present invention. [Figure 29] The table shows the results of the optical simulation. [Figure 30] This is a simulation diagram of the light distribution. [Figure 31] This is a simulation diagram of the light distribution. [Figure 32] This is a simulation diagram of the light distribution. [Figure 33] This is a simulation diagram of the light distribution. [Figure 34] This shows a light distribution graph. [Figure 35] This shows a light distribution graph. [Figure 36] A simulation diagram of the light distribution in another embodiment is shown. [Figure 37] A simulation diagram of the light distribution in another embodiment is shown. [Figure 38] A simulation diagram of the light distribution in another embodiment is shown. [Figure 39] A simulation diagram of the light distribution in another embodiment is shown. [Figure 40] This shows a light distribution graph. [Figure 41] This shows a light distribution graph. [Figure 42] This shows another first embodiment of the present invention. [Figure 43] This shows a second embodiment of the present invention. [Figure 44] This shows a third embodiment of the present invention. [Figure 45] This shows a fourth embodiment of the present invention. [Figure 46] This shows a fifth embodiment of the present invention. [Figure 47] A sixth embodiment of the present invention is shown. [Figure 48] This shows a seventh embodiment of the present invention. [Modes for carrying out the invention]

[0024] Please refer to Figure 1, which shows the optical film 100 of this patent. This optical film 100 is suitable as a component of an optical device including at least one light source. The optical device is, for example, a display device or a backlight module, and the light source refers to the LEDs of the display device or backlight module.

[0025] The optical film 100 of the present invention comprises a plurality of microstructures 111, a film body 112, and an opaque layer 120. These microstructures 111 are arranged on one side of the film body 112, and these microstructures 111 are protruding arc-shaped structures. The film body 112 can be made of a translucent material, such as polycarbonate (PC), polymethyl methacrylate (PMMA), polyethylene terephthalate (PET), or glass.

[0026] Among these, the thickness of the film body 112 and the equivalent diameter of the microstructure 111 are determined by optical properties and actual requirements. For example, when the film body 112 is viewed from above, if the microstructure 111 is circular, the equivalent diameter is calculated using the average value of the diameter of that circle. If the microstructure 111 is polygonal, the equivalent diameter is calculated using the average value of the diameter of the circumscribed circle of that polygon. The thickness of the film body 112 and the equivalent diameter of the microstructure 111 have a specific ratio relationship. In this embodiment, the equivalent diameter A of the microstructure 111 divided by the thickness t of the film body 112 is 1.3 or less and 0.7 or more.

[0027] The opaque layer 120 is positioned on the other side of the film body 112 opposite the microstructure 111, with the side of the opaque layer 120 facing the light source. In other words, the opaque layer 120 is positioned on the light incident surface of the optical film 100, and the microstructure 111 is positioned on the light emission surface of the optical film 100. The opaque layer 120 can be made of an opaque material such as nickel, silver, gold, aluminum, titanium oxide, or silicon dioxide. In one embodiment, the opaque layer 120 may also be made of a reflective material that reflects light from the light source. In another embodiment, the opaque layer 120 is made of a light-absorbing material, for example, formed by black ink.

[0028] Furthermore, the opaque layer 120 also includes a plurality of apertures 121. The design of these apertures 121 allows light to pass through the optical film 100 from specific angles. The positions of the microstructures 111 and the apertures 121 correspond to each other; specifically, the center point of the apertures 121 coincides with the center point of the microstructures 111 on the projection plane. The equivalent diameter of the microstructures 111 and the equivalent diameter of the apertures 121 are related. In this embodiment, the equivalent diameter d of the apertures 121 divided by the equivalent diameter A of the microstructures 111 is 0.3 or less.

[0029] Refer to Figure 2, which shows the optical film 100 and the light source. When the optical film 100 is placed on the light source module 10 and the side of the opaque layer 120 is aligned with the light source, the light emitted from the light source first encounters the opaque layer 120. Some of the large-angle light is blocked by the opaque layer 120, and another portion of the small-angle light passes through the opening 121 of the opaque layer 120 into the film body 112. Since the positions of the opening 121 and the microstructure 111 correspond to each other, the light that has passed through the opening 121 also passes through the microstructure 111. Furthermore, if the opaque layer 120 is a reflective material, it can reflect light from the light source module 10 and align with the reflector of the light source module 10 itself. Thus, the light that was originally blocked by the opaque layer 120 can pass through the opening 121 after reflection, reducing the overall loss of brightness.

[0030] At this stage, because the microstructure 111 adopts an arc shape, it can produce a lens effect, forming a collimated beam when light passing through the microstructure 111 is emitted. This effectively controls the conduction of light, ensuring that the light is emitted in a specific way, which is useful in subsequent applications. For example, it can be used as a privacy film for display modules or display panels.

[0031] Furthermore, the microstructures 111 and apertures 121 can be arranged in various ways. See Figures 3 and 4, which show the arrangement of the microstructures 111a and apertures 121a. In this embodiment, the microstructures 111a and apertures 121a are arranged on the optical film 100a in an evenly distributed, horizontally and vertically aligned arrangement.

[0032] Refer to Figures 5 and 6, which show the honeycomb arrangement of the microstructures 111b and openings 121b. In this embodiment, the microstructures 111b and openings 121b are arranged alternately along vertical lines, thereby creating the honeycomb arrangement.

[0033] Please refer to Figures 7 and 8, which show the random arrangement of the microstructures 111c and apertures 121c. In this embodiment, the microstructures 111c and apertures 121c are randomly distributed on the film body 112c or the opaque layer 120c and do not need to strictly follow a specific arrangement pattern. It should be noted that even though the microstructures 111c and apertures 121c are randomly arranged, there is a relative positional relationship between the microstructures 111c and apertures 121c, which is related to the manufacturing method of the optical film 100c, and this characteristic will be explained later.

[0034] Furthermore, the microstructures 111 do not need to be completely independent of each other. In some embodiments, the microstructures 111 can also intersect with each other. See Figures 9, 10, 11, 12, 13, and 14. Figures 9 to 11 show the arrangement and intersecting configuration of microstructures 111d, and Figures 12 to 14 show the honeycomb arrangement and intersecting configuration of microstructures 111e. Figure 11 is a three-dimensional image of the arrangement and intersecting configuration of microstructures 111d, and Figure 14 is a three-dimensional image of the honeycomb arrangement and intersecting configuration of microstructures 111e. In this embodiment, each microstructure 111d, 111e overlaps with adjacent microstructures 111d, 111e, forming an intersecting configuration. The openings 121d, 121e in the opaque layers 120d, 120e still correspond to the microstructures 111d, 111e.

[0035] In the embodiments shown in Figures 9 to 14, the equivalent diameter A of the microstructure 111 refers to the diameters of the microstructures 111d and 111e, specifically the polygon formed by the intersection of the microstructures 111d or 111e, where the length of its diagonal is the equivalent diameter A of the microstructure 111. Since the openings 121d and 121e are formed by the microstructures 111d or 111e, the openings 121d and 121e may form polygonal shapes, and the length of the diagonal of these polygons is the equivalent diameter d of the openings 121d and 121e. Next, a method for manufacturing the optical film 100 will be described.

[0036] Refer to Figures 15 and 16 to 28, which illustrate the method for manufacturing the optical film 100 of this patent. First, step S110 is performed (see Figure 16), providing a first mold substrate 210. Next, step S120 is performed (see Figure 17), forming a plurality of first microstructures 211 on the first mold substrate 210. For example, the first microstructures 211 are formed using lithography or diamond knife engraving techniques.

[0037] In this embodiment, a first microstructure 211 is formed using lithography in step S120. Specifically, a photosensitive material is coated onto the first mold substrate 210. These photosensitive materials are materials that react to light (usually ultraviolet light), and their chemical structure changes upon irradiation with light. Next, exposure is performed using a mask, and the pattern on the mask is projected onto the photosensitive material through light. Subsequently, the exposed photosensitive material is washed and removed using a developer to obtain the pattern of the corresponding first microstructure 211. Finally, an etching process is performed. This can be dry etching or wet etching, where an etchant is used to etch away the parts not protected by the photosensitive material, leaving the desired first microstructure 211.

[0038] After the fabrication of the first microstructure 211 is complete, step S130 is then performed (see Figure 18) to cast the second mold 220 onto the first microstructure 211. The second mold 220 contains multiple second microstructures 221, which correspond to the first microstructure 211. Furthermore, in step S130, the second mold 220 is formed by electroforming. Specifically, first an electrolyte containing metal ions is prepared. The metal ions are selected according to the material requirements of the second mold 220. Next, the first mold substrate 210 having the first microstructure 211 is placed in the electrolyte and connected to the negative electrode of a DC power supply, acting as the cathode for electroforming. At the same time, a plate of the same metal or an insoluble metal (e.g., platinum) is connected to the positive electrode of the DC power supply, acting as the anode for electroforming. Subsequently, when electricity is applied, metal ions move from the electrolyte to the surface of the first mold substrate 210 (cathode), where they undergo chemical reduction to form stable metal atoms that adhere to the surface of the first mold substrate 210. Since the surface of the first mold substrate 210 has first microstructures 211, the metal atoms adhere according to the shape of these first microstructures 211, forming second microstructures 221 of the same shape. When these metal atoms reach a certain thickness, the surface of the second mold 220 and the corresponding second microstructure 211 is formed.

[0039] After the second mold 220 is formed, step S140 is performed (see Figure 19), the first mold substrate 210 is removed, leaving the second mold 220 and the second microstructure 221. Next, step S150 is performed (see Figure 20), providing a film substrate 201. The film substrate 201 is a transparent material such as polycarbonate (PC), polymethyl methacrylate (PMMA), polyethylene terephthalate (PET), or glass. Next, step S160 is performed (see Figure 21), forming a microstructure layer 202 on the film substrate 201. Next, step S170 is performed (see Figure 22), using the second mold 220 to transfer the second microstructure 221 to the microstructure layer 202, so that the microstructure layer 202 forms a plurality of third microstructures 231. After removing the second mold 220, a film substrate 201 with the third microstructures 231 is obtained (see Figure 23).

[0040] In one embodiment, steps S150 and S170 form the optical film 230 using hot stamping. First, a plastic sheet or film (i.e., a microstructure layer 202) is placed on a film substrate 201. Next, the plastic sheet or film is heated above its melting point. Then, when the plastic or film has softened, a second mold 220 is pressed into the plastic sheet or film to transfer the shape of the second microstructure 221 to the plastic sheet or film. After the plastic sheet or film has cooled and the second mold 220 has been removed, a film substrate 201 having a third microstructure 231 is obtained.

[0041] In another embodiment, steps S150 and S170 are used to form a third microstructure 231 using UV imprinting. First, a UV-curable resin is applied (i.e., a microstructure layer 202), then the second mold 220 is brought into contact with the UV-curable resin, and appropriate pressure is applied to ensure that the UV-curable resin and the second microstructure 221 are in complete contact. The UV-curable resin is then irradiated with UV light, allowing it to cure and form a third microstructure 231 corresponding to the second microstructure 221. Removing the second mold 220 yields a film substrate 201 having the third microstructure 231.

[0042] After obtaining a film substrate 201 having a third microstructure 231, step S180 is performed (see Figure 24) to form a negative-type photoresist layer 240 on the optical film 230. The negative-type photoresist layer 240 is positioned on the opposite side of the third microstructure 231. The negative-type photoresist layer 240 is made of a photosensitive material and its chemical structure changes when exposed to light.

[0043] Next, step S190 is performed (see Figure 25), exposing the negative-type photoresist layer 240 from the front of the film substrate 201, that is, from the side of the third microstructure 231. At this time, the third microstructure 231 can produce a miniature lens effect because its arc-shaped surface can focus the exposure light to a specific position and guide the exposure light to a specific position on the negative-type photoresist layer 240.

[0044] After exposure, step S200 is performed (see Figure 26) to remove the unexposed portion of the negative-type photoresist layer 240. Specifically, when a portion of the negative-type photoresist layer 240 is exposed to light, it undergoes a chemical change and hardens, and by using a developer to remove the unexposed portion, a first opening 241 is formed on the negative-type photoresist layer 240. In steps S180 to S200, self-alignment techniques are used, utilizing the optical properties of the third microstructure 231 to form the first opening 241 on the negative-type photoresist layer 240. Therefore, the first opening 241 and the third microstructure 231 have a corresponding positional relationship.

[0045] After forming the first opening 241, step S210 is performed (see Figure 27) to form an opaque layer 250 within the first opening 241. Then, step S220 is performed (see Figure 28) to remove the negative-type photoresist layer 240, thereby obtaining an opaque layer 250 having a plurality of second openings 251. These second openings 251 correspond to the opening 121 in Figure 1. This completes the manufacturing of the optical film 230(100) of the present patent, and the simulation and experimental results of the optical film 100 will now be described.

[0046] Please refer to Figure 29, which is a table of optical simulation results. The parameters used in this simulation include aperture ratio α and optical efficiency EFF. Aperture ratio represents the ratio of the aperture area of ​​the optical film 100 to the total area of ​​the optical film 100, and optical efficiency represents the percentage of luminous flux remaining after light has passed through the optical film 100. The optical film 100 used in the simulation is an array of microstructures 111, each with a length and width of 5 mm and a thickness of 0.1 mm. Optical films 100 with aperture ratios α of 100%, 10%, 20%, and 30% were used in multiple simulations. The light source is a 5050 LED package.

[0047] In Figure 29, no optical film 100 is used, meaning the aperture ratio α is 100%. In this case, the luminous flux is 9.473 units and the luminous efficiency is 100% because there is no material blocking the passage of light. When optical film 100 with an aperture ratio α of 10% is used, the luminous flux decreases to 0.234 units and the corresponding luminous efficiency EFF is 2.47%. When optical film 100 with an aperture ratio α of 20% is used, the luminous flux increases to 0.872 units and the corresponding luminous efficiency EFF is 9.2%. When optical film 100 with an aperture ratio α of 30% is used, the luminous flux increases further to 1.753 units and the corresponding luminous efficiency EFF is 18.5%.

[0048] Next, please refer to Figures 30 to 33. These are light distribution simulation diagrams. In Figure 30, the optical film 100 is not used (corresponding to an aperture ratio α of 100% in Figure 29), and the light emitted from the light source is completely dispersed. In Figure 31, the optical film 100 with an aperture ratio of 10% is used (corresponding to an aperture ratio α of 10% in Figure 29), and it can be observed that the light is significantly concentrated in the center, and the brightness is relatively reduced. In Figure 32, the optical film 100 with an aperture ratio of 20% is used (corresponding to an aperture ratio α of 20% in Figure 29), and the light is still concentrated in the center, with a slight increase in brightness and area compared to Figure 31. In Figure 33, the optical film 100 with an aperture ratio of 30% is used (corresponding to an aperture ratio α of 30% in Figure 29), and the situation of light being concentrated in the center is maintained, with higher brightness and area than in Figure 32, and some brightness can be observed in the periphery as well. From the simulation results, it can be seen that the optical film 100 has the ability to control light. When light passes through the microstructure 111 of the film, its propagation path and distribution change due to the intervention of the microstructure 111.

[0049] Next, please refer to Figures 34 and 35. These are light distribution diagrams. These light distribution diagrams correspond to Figures 30 through 33 and are used to show light intensity from different viewing angles. In these, Figure 34 uses light intensity as the unit on the vertical axis, and Figure 35 uses relative light intensity as the unit on the vertical axis. Also, curve 501 corresponds to Figure 30, curve 502 corresponds to Figure 31, curve 503 corresponds to Figure 32, and curve 504 corresponds to Figure 33. In these diagrams, 0 degrees corresponds to visualization perpendicular to the optical film 100, and ±90 degrees corresponds to visualization parallel to the optical film 100.

[0050] From Figures 34 and 35, when the optical film 100 is not used, curve 501 is very smooth, with maximum light intensity at 0 degrees and gradually decreasing as it approaches ±90 degrees. In other words, the light is visible from most angles. However, curves 502 to 504 have maximum light intensity within the range of ±10 degrees, and the light intensity decreases significantly outside the range of ±10 degrees. This means that after using the optical film 100, good light intensity can be obtained within the range of ±10 degrees, which also means that it is visible within the range of ±10 degrees. Of particular note is the phenomenon of protrusions in curves 503 and 504 at the ±50 degree position. This means that when the aperture ratio is large, light leakage occurs at this position.

[0051] Refer to Figures 36 to 39, which are light distribution simulation diagrams of another embodiment. In this embodiment, the optical film 100 used in the simulation is an array of microstructures 111, each with a length and width of 5 mm and a thickness of 0.1 mm, and the light source is a 5050 LED or backlight module package, which includes common backlight module components such as a diffuser plate and a brightness enhancement film (or dual brightness enhancement film).

[0052] In Figure 36, an LED is used as the light source, and the optical film 100 is not used; the light emitted from the light source is completely dispersed. In Figure 37, an optical film 100 with an aperture ratio of 10% is used, and it can be observed that the light is significantly concentrated in the center.

[0053] In Figure 38, the display module is used as the light source, and the optical film 100 is not used. The light emitted from the light source is completely diffused, and the light intensity is stronger in the vertical direction due to the influence of the diffuser or reinforcing film. In Figure 39, the optical film 100 with an aperture ratio of 10% is used with the display module, and it can be observed that the light is greatly concentrated in the center, which is very similar to the simulation result in Figure 37.

[0054] Please refer to Figures 40 and 41. These show light distribution graphs. As you can see, curve 601 corresponds to Figure 36, curve 602 corresponds to Figure 37, and curves 603 and 603' correspond to Figure 38, where curve 603 represents horizontal light intensity and curve 603' represents vertical light intensity. Curve 604 corresponds to Figure 39. From Figures 40 and 41, curves 601, 603, and 603', i.e., when the optical film 100 is not used, are very smooth, with maximum light intensity at 0 degrees and gradually decreasing as it approaches ±90 degrees. In other words, light can be seen from most angles. However, curves 602 and 604 have maximum light intensity within the range of ±10 degrees, and the light intensity decreases significantly outside the range of ±10 degrees.

[0055] Combining the simulation results in Figures 30 to 35 and Figures 36 to 41, we can see that after using the optical film 100 of this patent, light is effectively focused within ±10 degrees, achieving a degree of privacy protection. Furthermore, whether using a simple LED as the light source or a display module (including a diffuser and reinforcing film), the optical film 100 of this patent can produce considerable results after refraction. Next, we will discuss the application of the optical film 100 of this patent as a component of optical devices.

[0056] Please refer to Figure 42, which illustrates a first embodiment of the application. In the embodiment of Figure 42, the optical film 100 is directly covered onto the display module 301, and optical transparent adhesive 350 (OCA) is used for fixation. Thus, the optical film 100 is placed on the light source 310, diffuser plate 320, optical component 330, and liquid crystal panel 340. Specifically, in the embodiment of Figure 42, the optical film 100 is fixed to the display module of the display screen to achieve a privacy effect.

[0057] Please refer to Figure 43, which shows a second embodiment of the application. In the embodiment of Figure 43, the optical film 100 is integrated into the display module 301. The optical film 100 is positioned between the optical component 330 and the liquid crystal panel 340.

[0058] Please refer to Figure 44, which shows a third embodiment of the application. In the embodiment of Figure 44, the optical film 100 replaces the original optical component 330 of the display module 301. Thus, the optical film 100 is placed on the diffuser plate 320. In one embodiment, the diffuser plate 320 can be bonded using optical transparent adhesive 350 (OCA). That is, the diffuser plate 320 is bonded to the underside of the optical film 100 via the optical transparent adhesive 350.

[0059] Please refer to Figure 45, which shows a fourth embodiment of the application. In the embodiment of Figure 45, the display module 301 is comprised solely of the optical film 100. This allows for a further reduction in the thickness of the display module 301.

[0060] Please refer to Figure 46, which shows a fifth embodiment of the application. In the embodiment of Figure 46, the optical film 100 is integrated into another type of display module 301'. The optical film 100 is positioned between the optical component 330 and the liquid crystal panel 340. Below the optical component 330 is a light guide plate 312, and on the side of the light guide plate 312 is a light-emitting component 311.

[0061] Please refer to Figure 47, which shows a sixth embodiment of the application. In the embodiment of Figure 47, the display module 301' is composed solely of the optical film 100. This allows for a further reduction in the thickness of the display module 301'.

[0062] Figures 42 to 46 show various methods for integrating the optical film 100 into the display module 301, utilizing the properties of the optical film 100 to effectively control light propagation and achieve a privacy effect.

[0063] Please refer to Figure 48, which shows a seventh embodiment of the application. In the embodiment of Figure 48, a polarizing beam splitter (PBS) 410 is integrated. Light emitted from the light source 310 forms collimated light after passing through the optical film 100. This collimated light is further reflected by the polarizing beam splitter to a spatial light modulator 420, which is, for example, a liquid crystal (LCOS) component on silicon.

[0064] Because the optical film 100 of this patent provides collimated light, it offers excellent uniformity and transmission efficiency, and can be used in combination with polarizing beam splitters and LCOS components in projectors, head-mounted devices, virtual reality devices, etc. This provides better resolution and image quality. Furthermore, the optical film 100 of this patent can replace various optical components such as films and lenses in projectors, head-mounted devices, and virtual reality devices, further reducing the thickness and manufacturing cost of the device.

[0065] In summary, the optical film 100 of this patent can effectively generate collimated light by utilizing the relationship between the aperture 121 of the opaque layer 120 and the microstructure 111. This is extremely useful in many applications. For example, it can be used as a privacy film to provide privacy protection. This film allows the display to be viewed from a specific angle, while the content cannot be seen from other angles. This is applicable to devices used in public places, such as ATMs and personal computers.

[0066] Optical film 100 can also be used in head-mounted devices, such as virtual reality (VR) headsets. Because collimated light has more effective light transmission efficiency and reduces light scattering and reflection, optical film helps improve display quality. This results in clearer, more vivid images, better contrast, and more vibrant colors. Optical film 100 can also replace some optical components such as lenses and films in display modules, further reducing the thickness and manufacturing cost of the display module. [Explanation of Symbols]

[0067] 100 Optical Film 111 Microstructure 111a Microstructure 112 Film body 120 Opaque layer 121 Opening 121a opening 201 Film substrate 211 First microstructure 220 Second type 221 Second microstructure 230 Optical Film 231 The third microstructure 240 Photoresist Layers 301 Display Module 310 light source 320 Diffuser 330 Optical Components 340 LCD panel, 410 polarizing beam splitter 420 Spatial Light Modulator

Claims

1. An optical film for use as a component of an optical device including a light source, The optical film is The film itself, A protruding arc-shaped convex lens structure capable of generating collimated light, comprising a plurality of microstructures arranged on one side of the film body, It includes an opaque layer fixed to the film body, set on the other side of the film body, i.e., opposite to the microstructure, and having a plurality of openings, At least some of the aforementioned microstructures, when viewed from above, overlap and intersect with each other, The center point of each opening coincides with the center point of each microstructure on the projection plane, the value obtained by dividing the equivalent diameter d of the opening by the equivalent diameter A of the microstructure is 0.3 or less, and the value obtained by dividing the equivalent diameter A of the microstructure by the thickness t of the film body is 1.3 or less and 0.7 or more. When the aforementioned microstructure is viewed from above, if a polygon is formed by the intersection of multiple such microstructures, the equivalent diameter A is defined as the length of the diagonal of the polygon, and the equivalent diameter d of the opening is defined as the length of the diagonal of the polygon of the opening. The opaque layer is positioned facing the light source, The optical film is an optical film that generates collimated light when light passing from the light source through the aperture is refracted through the microstructure.

2. The optical film according to claim 1, wherein the microstructure and the openings are uniformly arranged on the film body.

3. The optical film according to claim 1, wherein the microstructure and the openings are arranged in an array pattern.

4. The optical film according to claim 1, wherein the microstructure and the openings are arranged in a honeycomb pattern.

5. The optical film according to claim 1, wherein the microstructure and the openings are randomly arranged on the film body.

6. The optical film according to claim 1, wherein the opaque layer is composed of a light-absorbing material.

7. The optical film according to claim 1, wherein the film body is composed of one or more materials selected from the group consisting of polycarbonate (PC), polymethyl methacrylate (PMMA), polyethylene terephthalate (PET), and glass, and the opaque layer is composed of one or more materials selected from the group consisting of nickel, silver, gold, aluminum, titanium oxide, and silicon dioxide.

8. The optical film according to claim 1, wherein the opaque layer is a reflective material.

9. At least one optical film according to any one of claims 1 to 8, Includes multiple light sources placed beneath an optical film, The optical film is oriented toward the light source on the side having the opaque layer in the display module.

10. The display module according to claim 9, comprising at least one diffusion layer, the diffusion layer being positioned between the optical film and the light source.

11. The display module according to claim 10, wherein the diffusion layer is fixed to the underside of the optical film.

12. Furthermore, the display module according to claim 9, further comprising a liquid crystal panel, the liquid crystal panel being disposed on the optical film.

13. The display module according to claim 9, further comprising a polarizing beam splitter and a spatial light modulator, wherein the polarizing beam splitter is positioned on the optical film and light emitted from the light source is reflected by the polarizing beam splitter to the spatial light modulator.

14. Display module and A display module comprising at least one optical film according to any one of claims 1 to 8, The optical film is a display screen in which the side having the opaque layer is oriented toward the display module.

15. A method for manufacturing an optical film according to claim 1, The plurality of openings in the opaque layer are formed by a self-aligned photolithography process. The self-aligning photolithography process is a manufacturing method comprising the steps of: forming a photoresist layer on the other side of the film body on which the microstructure is arranged on one side; exposing the film from the microstructure side and using each of the microstructures as a focusing lens to guide incident light to each portion of the photoresist layer corresponding to each of the microstructures, thereby forming unexposed and exposed portions; removing the unexposed portions of the photoresist layer and forming the opaque layer in the removed portions; and removing the exposed portions of the photoresist layer.

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