Depolarizing film, eye-protecting optical film, preparation method of eye-protecting optical film and wearable optical equipment

Abstract

The invention discloses a depolarization film, an eye protection optical film, a preparation method of the eye protection optical film and wearable optical equipment, and relates to the technical field of optical structure.The depolarization film is arranged on the light emitting side of an optical device with a polarization function and used for converting linearly polarized light formed by penetrating through the optical device with the polarization function into non-polarized light; the acute angle formed by the direction of the optical slow axis of the depolarization film and the direction of the polarization absorption axis of the optical device with the polarization function is 15-45 degrees. The depolarization film is arranged on the light emitting side of the optical device with the polarization function at the preset angle, linearly polarized light can be converted into non-polarized light, continuous stimulation of light in a single polarization direction to eyes is avoided, and eye fatigue is relieved fundamentally.

Description

Technical Field

[0001] This application relates to the field of optical structure technology, and in particular to a polarization depolarizing film, an eye-protecting optical film and its preparation method, and wearable optical devices. Background Technology

[0002] Polarized glasses, as an optical device that can filter polarized light, are widely used in outdoor scenarios, especially during driving. They can effectively filter glare reflected from the ground, water, and other object surfaces, improve visual contrast and clarity, and ensure the user's visual safety, thus gaining widespread popularity.

[0003] Currently, the core component of existing polarized glasses is the linearly polarized lens. Its working principle involves a polarizer in the lens selectively allowing linearly polarized light vibrating in a specific direction to pass through, thereby filtering out stray light and glare from other directions. However, these linearly polarized lenses have significant drawbacks: because they only allow linearly polarized light in a single direction to reach the retina, prolonged stimulation from this single polarization direction causes the eye muscles to remain in a state of constant tension, disrupting the eye's normal visual physiological balance and leading to discomfort such as eye fatigue and dryness. More seriously, the accumulation of eye fatigue can reduce the excitability of the user's nervous system, easily causing drowsiness, which greatly increases safety risks in scenarios requiring high concentration, such as driving and outdoor sports.

[0004] In view of the shortcomings of the existing technologies, there is an urgent need for a technical solution that can effectively relieve eye fatigue while achieving the function of polarized anti-glare. Summary of the Invention

[0005] The main purpose of this application is to propose an anti-polarization film, an eye-protecting optical film, a method for preparing the same, and a wearable optical device, aiming to overcome the defect that existing optical devices with polarization functions easily cause eye fatigue.

[0006] To achieve the above objectives, the depolarization film proposed in this application is disposed on the light-emitting side of an optical device with polarization function, and is used to convert linearly polarized light formed through the optical device with polarization function into unpolarized light. The acute angle between the direction of the slow optical axis of the depolarization film and the direction of the polarization absorption axis of the optical device with polarization function is 15~45°.

[0007] Preferably, the angular deviation of the optical slow axis is 0~20°.

[0008] Preferably, the in-plane delay value of the depolarization functional layer is not less than 2000 nm.

[0009] Preferably, the in-plane delay value of the depolarization functional layer is 6000~20000 nm.

[0010] This application also proposes an eye-protecting optical film, which includes a polarizing functional layer and a depolarizing functional layer stacked together, wherein the depolarizing functional layer includes the depolarizing film proposed in this application. The depolarization functional layer is disposed on the side of the polarization functional layer closer to the observer's eye, and the acute angle formed by the direction of the optical slow axis of the depolarization functional layer and the direction of the polarization absorption axis of the polarization functional layer is 15~45°.

[0011] Preferably, the acute angle between the direction of the slow optical axis of the depolarization functional layer and the direction of the polarization absorption axis of the polarization functional layer is 25~45°.

[0012] Preferably, the polarization degree of the polarizing functional layer is 20-48%.

[0013] Preferably, the polarization degree of the polarization functional layer is 25-45%.

[0014] Preferably, a protective layer is provided on both sides of the polarizing functional layer, and the light transmittance of the protective layer is not less than 87%.

[0015] Preferably, the protective layer is made from at least one of the following raw materials: cellulose triacetate, cyclic olefin polymer, and polymethyl methacrylate.

[0016] This application also proposes a method for preparing the eye-protecting optical film proposed in this application, comprising: A polyethylene terephthalate raw material is provided, an opening agent is added thereto, and a multilayer casting sheet containing at least a core layer and a surface layer is formed by melt co-extrusion; the multilayer casting sheet is subjected to biaxial stretching and heat setting treatment to obtain a polarization-degrading film. A polarizing functional layer is provided, and the depolarizing functional film is attached to one side of the polarizing functional layer, such that the acute angle formed between the slow axis direction of the depolarizing functional film and the polarization absorption axis direction of the polarizing functional layer is 15~45°.

[0017] This application also proposes a wearable optical device, including the polarization depolarization film or the eye-protection optical film proposed in this application.

[0018] The depolarization film of this application is set at a preset angle on the light-emitting side of an optical device with polarization function. When light shines on the optical device with polarization function, the optical device with polarization function can filter stray light and glare in the incident light and form linearly polarized light. The depolarization film further converts the linearly polarized light into unpolarized light, thereby avoiding continuous stimulation of the eyes by light with a single polarization direction and fundamentally relieving eye fatigue. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0020] Figure 1 A schematic diagram showing the acute angle formed between the direction of the optical slow axis of the depolarization functional layer provided in this application and the direction of the polarization absorption axis of the optical device with polarization function. Figure 2 A schematic diagram showing the angle between the optical slow axis and the reference direction of the depolarization functional layer provided in this application; Figure 3 This is a schematic diagram of the structure of the eye-protecting optical film provided in this application.

[0021] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0022] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0023] It should be noted that if the embodiments of this application involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0024] Furthermore, if the embodiments of this application involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution that simultaneously satisfies A and B. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed in this application.

[0025] Please see Figure 1 This application proposes an antipolarizing film, disposed on the light-emitting side of an optical device with polarizing function, for converting linearly polarized light transmitted through the optical device into unpolarized light. The acute angle between the direction of the slow optical axis of the antipolarizing film and the direction of the polarization absorption axis of the optical device with polarizing function is 15° to 45°. For example, the acute angle between the direction of the slow optical axis of the antipolarizing film and the direction of the polarization absorption axis of the optical device with polarizing function can be 15°, 20°, 25°, 30°, 35°, 40°, or 45°. It can be understood that the polarization absorption axis refers to the light filtering direction of the optical device with polarizing function, the fast optical axis refers to the direction with the lowest refractive index within the antipolarizing film, and the slow optical axis refers to the direction with the highest refractive index within the antipolarizing film.

[0026] By setting the depolarization film at the aforementioned specific angle on the light-emitting side of the optical device with polarization function, when light shines on the optical device with polarization function, the optical device with polarization function can filter stray light and glare in the incident light and form linearly polarized light. The depolarization film further converts the linearly polarized light into unpolarized light, thereby avoiding the continuous stimulation of the eyes by light with a single polarization direction and fundamentally relieving eye fatigue.

[0027] In some embodiments, the optical device with polarizing function can be an optical device with polarizing function in a display or imaging system, such as a lens, a light-transmitting panel, or a screen.

[0028] In some embodiments, the angular deviation Δβ of the optical slow axis of the depolarization film is 0~20°. For example, the angular deviation of the optical slow axis of the depolarization functional layer is 0, 5°, 10°, 15°, or 20°, etc. Preferably, the angular deviation of the optical slow axis of the depolarization functional layer is 0~10°. In conjunction with the foregoing, such as... Figure 2As shown, the optical slow axis angle deviation Δβ refers to the acute angle β between any point on the reference line along any direction within the thin film and the reference direction. i The difference between β1 and β2, β1 or β2 i The selected position is arbitrary. The depolarization function can be guaranteed by controlling the angular deviation of the optical slow axis of the depolarization function layer to be 0~20°.

[0029] In some embodiments, the in-plane retardation value of the depolarization film is not less than 2000 nm. The in-plane retardation value refers to the optical path difference between the o-ray (ordinary ray) and e-ray (extraordinary ray), whose vibration directions are perpendicular, when a beam of light passes perpendicularly through the depolarization functional layer. If the in-plane retardation value of the depolarization film is less than 2000 nm, the phase difference between different wavelengths fluctuates randomly and deteriorates, failing to achieve the depolarization effect. Preferably, the in-plane retardation value of the depolarization film is 6000~20000 nm. For example, the in-plane retardation value of the depolarization film can be 6000 nm, 10000 nm, 15000 nm, or 20000 nm, etc. This setting allows the depolarization film to generate a large phase difference through birefringence, causing the phase difference between the o-ray and e-ray after birefringence to fluctuate randomly at different positions and wavelengths, resulting in an isotropic statistical distribution of the polarization state of the outgoing light, ultimately achieving a "polarization-independent" optical effect. In theory, the larger the in-plane delay value, the higher the requirements for production and processing, and the higher the cost. If the in-plane delay value of the depolarization functional layer is greater than 20,000 nm, it cannot provide a better depolarization effect.

[0030] In some embodiments, the depolarization film is made of at least one of polyethylene terephthalate, polyethylene naphthol, and polyethylene terephthalate-1,4-cyclohexanediol.

[0031] In some embodiments, the depolarization film material further includes a UV-absorbing substance, which includes at least one of an organic UV absorber and an inorganic UV shielding agent. Further, the organic UV absorber includes at least one of a benzophenone compound or a benzotriazole compound, and the inorganic UV shielding agent includes at least one of surface-modified nano-zinc oxide or nano-titanium dioxide. For example, the UV absorber can be at least one of BPMA, RUVA-93, HY-UV5, and T-ZnOw.

[0032] Please see Figure 3 This application also proposes an eye-protecting optical film, comprising a polarizing functional layer and a depolarizing functional layer stacked together, wherein the depolarizing functional layer includes the depolarizing film as described above.

[0033] Specifically, the depolarization layer is disposed on the side of the polarization layer closest to the observer's eye. The acute angle between the direction of the slow optical axis of the depolarization layer and the direction of the polarization absorption axis of the polarization layer is 15° to 45°. The polarization layer is used to filter stray light and glare in the incident light and form linearly polarized light, while the depolarization layer is used to convert linearly polarized light into unpolarized light. Preferably, the acute angle between the direction of the slow optical axis of the depolarization layer and the direction of the polarization absorption axis of the polarization layer is 25° to 45°. By adopting the above configuration, the depolarization layer can have better depolarization effect and a larger depolarization effect at a wider tilt angle.

[0034] In some embodiments, the polarization degree of the polarizing functional layer is 20% to 48%. For example, the polarization degree of the polarizing functional layer is 20%, 25%, 30%, 35%, 40%, 45%, or 48%. If the polarization degree of the polarizing functional layer is less than 20%, the polarization characteristics are insufficient, and it cannot filter strong light and various types of glare; if the polarization degree is greater than 48%, on the one hand, industrial applications are more limited, and on the other hand, the anti-glare effect is not significantly advantageous. Preferably, the polarization degree of the polarizing functional layer is 25% to 45%.

[0035] The eye-protecting optical film of this application includes a polarizing functional layer and a depolarizing functional layer stacked together. When light shines on the composite film, the polarizing functional layer filters stray light and glare in the incident light and forms linearly polarized light. The depolarizing functional layer further converts the linearly polarized light into unpolarized light, thereby converting the light incident on the retina into unpolarized light through the composite film. At the same time, the optical slow axis of the depolarizing functional layer and the polarization absorption axis of the polarizing functional layer are shortened to an acute angle of 15~45°, which makes the eye-protecting optical film have a better depolarization effect and increases the depolarization effect at tilted viewing angles. This avoids the continuous stimulation of the eyes by light with a single polarization direction and fundamentally relieves eye fatigue.

[0036] In some embodiments, the polarizing functional layer can be an iodine-based polarizing film or a dye-based polarizing film. Specifically, if the polarizing functional layer is an iodine-based polarizing film, it can be prepared using polyvinyl alcohol resin through processes such as dissolution, casting, dyeing, and stretching; if the polarizing functional layer is a dye-based polarizing film, it can be obtained by adding substances with or without dichroism after stretching to thermoplastic polymers such as polyolefins, and then through blending extrusion, casting, and stretching.

[0037] Because the polarizing functional layer is relatively fragile, protective layers can be provided on both sides of the polarizing functional layer to improve its durability. In some embodiments, the light transmittance of the protective layer is not less than 87%.

[0038] In some embodiments, the protective layer material includes at least one of cellulose triacetate (TAC), polymethyl methacrylate (PMMA), and cyclic olefin polymer (COP). Preferably, the protective layer material is TAC, a proven traditional material with extremely high optical transmittance (93%), mature processing, and high reliability.

[0039] In some implementations, the polarizing functional layer can be in the blue, red, or gray color scheme.

[0040] The depolarization functional layer has all the technical features of the depolarization film as described above, and will not be repeated here.

[0041] In addition, in some embodiments, the material of the polarization depolarization functional layer includes at least one of polyethylene terephthalate, polyethylene naphthol, and polyethylene terephthalate-1,4-cyclohexanediol.

[0042] In some embodiments, the material of the polarization depolarization functional layer further includes a UV-absorbing substance, which includes at least one of an organic UV absorber and an inorganic UV shielding agent. Further, the organic UV absorber includes at least one of a benzophenone compound or a benzotriazole compound, and the inorganic UV shielding agent includes at least one of surface-modified nano-zinc oxide or nano-titanium dioxide. For example, the UV absorber can be at least one of BPMA, RUVA-93, HY-UV5, and T-ZnOw.

[0043] In some embodiments, the depolarization functional layer further includes a hardening coating disposed on the side of the depolarization functional layer close to the polarization functional layer to improve the scratch resistance of the eye-protection optical film.

[0044] This application also provides a method for preparing the eye-protecting optical film as described above, comprising: S1. Provide a polymer raw material, add an opening agent therein, and form a multilayer casting sheet containing at least a core layer and a surface layer by melt co-extrusion; subject the multilayer casting sheet to biaxial stretching and heat setting treatment to obtain a polarization-degrading film. S2. Provide a polarizing functional layer, attach the depolarizing functional film to one side of the polarizing functional layer, and make the acute angle formed by the slow axis direction of the depolarizing functional film and the polarization absorption axis direction of the polarizing functional layer 15~45°.

[0045] The opening agent includes at least one of oleamide, talc, silica, and barium sulfate. Preferably, the opening agent is silica particles with a particle size of 1-10 μm, and more preferably, a particle size of 1.5-5 μm. Increasing the particle size of silica helps to improve the slippery effect, but it also increases the surface haze. If the particle size of silica is less than 1.5 μm, the slippery effect cannot be guaranteed.

[0046] In some embodiments, the concentration of the opening agent in S1 is 500-9000 ppm, for example, the concentration of the opening agent can be 500 ppm, 800 ppm, 1000 ppm, 5000 ppm, 6000 ppm, or 9000 ppm, etc. If the content of the opening agent exceeds 9000 ppm, it will affect the optical and mechanical properties of the film; however, if the content is less than 500 ppm, the adhesion problem of the film cannot be solved. Preferably, the concentration of the opening agent is 600-8000 ppm.

[0047] In some embodiments, the polymer raw material is polyethylene terephthalate, and S1 includes the following steps: Polyethylene terephthalate (PET) chips are dried to reduce their moisture content to below 200 ppm. The dried polyester chips are then melt-extruded using an extruder, which may include single-screw extruders or twin-screw extruders.

[0048] Taking a conventional single-screw extruder as an example, specifically, the feeding section temperature is Tm (melt temperature) ± 30℃ of the polymer raw material, the compression section temperature is Tm~Tm+35℃, the homogenization section temperature is Tm~Tm+35℃, and the die temperature is Tm~Tm+30℃; more preferably, the feeding section temperature is Tm± 20℃, the compression section temperature is Tm~Tm+15℃, the homogenization section temperature is Tm+15~Tm+30℃, and the die temperature is Tm+15~Tm+30℃. If the feeding section temperature is lower than Tm, the single-screw extruder will not be able to provide sufficient forward thrust to allow the material to enter the compression section. If the feeding section temperature is higher than Tm+30℃, the polyester chips will melt in the feeding section due to excessive temperature and will not be able to enter the compression section. If the compression section temperature is lower than Tm, the material cannot be fully plasticized in the compression section. If the temperature is higher than Tm+35℃, melt fracture is likely to occur, leading to unstable pressure in the front section. The principles for setting the homogenization section and die temperature are the same as those described above.

[0049] In some embodiments, foreign matter and some incompletely plasticized particles in the raw material are filtered out. Preferably, a high-precision filter screen is added to the extruder during melt extrusion. The filter screen includes disc filters, mesh filters, etc. The filtered particle size is less than 15 μm, more preferably less than 10 μm.

[0050] In some embodiments, biaxial stretching in S1 refers to applying a stretching action to the casting in both the mechanical direction (MD) and the direction perpendicular to the mechanical direction (TD). The biaxial stretching steps include: preheating before MD stretching, MD stretching, and MD heat treatment; preheating before TD stretching, TD stretching, and TD heat treatment. Specifically, the MD preheating temperature is 50~120℃, the MD stretching temperature is 60~130℃, and the MD heat treatment temperature is 20~50℃. More specifically, the TD preheating temperature is 70~150℃, and the TD stretching temperature is 70~150℃, more preferably 75~140℃.

[0051] This application also proposes a wearable device, including the polarization depolarization film as described above or the eye protection optical film as described above.

[0052] In some implementations, wearable devices include glasses.

[0053] For example, when wearing glasses containing the aforementioned eye-protecting optical film, external light (such as sunlight, road glare, etc.) first enters from the polarizing layer side, passing through the polarizing layer and the depolarizing layer in sequence before entering the eye. The polarizing layer filters out most stray light and horizontal glare, allowing only polarized light with the same polarization direction as the polarizing layer to pass through. Subsequently, this linearly polarized light is converted into unpolarized light when passing through the depolarizing layer, ultimately reaching the retina as unpolarized light. This avoids continuous stimulation from a single polarized light, thereby relieving eye fatigue.

[0054] The following specific examples provide further details.

[0055] Example 1 Polyethylene terephthalate (PET) with an intrinsic viscosity of 0.67 dl / g was selected, sliced, and silica particles with a concentration of 8000 ppm and a particle size of 2 μm were added. The mixture was thoroughly and physically mixed to obtain a PET masterbatch for the surface layer.

[0056] 20 parts by weight of core layer PET masterbatch and 100 parts by weight of PET chips with an intrinsic viscosity of 0.67 dl / g were fed into a twin-screw extruder. The feeding section temperature was set to 245℃, the compression section temperature to 275℃, the homogenization section temperature to 275℃, and the die temperature to 275℃. The screw speed and metering pump speed were adjusted to stabilize the post-pump pressure at 2 MPa.

[0057] 20 parts by weight of surface PET masterbatch and 80 parts by weight of PET chips with an intrinsic viscosity of 0.67 dl / g were fed into a twin-screw extruder. The temperature of the melt extrusion section was set to increase from 260℃ to 270℃, and the temperature of the melt conveying section and the die head was set to 272℃.

[0058] Electrostatic bonding is used to press the three layers of molten material flowing from the die onto a cooling roller for quenching. The cooling roller temperature is kept constant at 28℃. Amorphous cast sheets of different thicknesses are produced by adjusting the extrusion rate to achieve a thickness ratio of 12:76:12 for the three layers of the film. By adjusting the extrusion rate, cast sheets of different thicknesses can be obtained.

[0059] Using the above-mentioned cast wafer, preheating was performed at 80°C, followed by MD preheating (80°C), MD stretching (90°C) twice, MD heat treatment (28°C), preheating at 95°C, lateral stretching at 105°C 4.1 times, and then heat treatment at 220°C to obtain a thin film I with a thickness of 60 μm. The MD and TD directions were marked, and the film's R0 was measured at 550 nm wavelength using a phase difference meter (RETS-100L), yielding a value of 6380 nm and an interpolation Δβ of 6° for any ten β values ​​with the TD direction as the reference direction.

[0060] A polarizing functional layer formed of polyvinyl alcohol (PVA) and iodine is provided, and a polarizing film (Derrig, T11-NT) composed of cellulose triacetate is laminated on both sides of the polarizing film. Then, the above-mentioned film I is laminated on one side of the polarizing functional layer, such that the acute angle between the optical slow axis direction of the above-mentioned film I and the polarization absorption axis direction of the polarizing functional layer is 45°, thus obtaining an eye-protecting optical film.

[0061] Example 2 A polarizing film formed of polyvinyl alcohol (PVA) and iodine is provided, and a polarizing film (Derrig, T11-NT) composed of cellulose triacetate with polarizing function is laminated on both sides of the polarizing film. Then, the above-mentioned film I is laminated on one side of the polarizing functional layer, such that the acute angle between the optical slow axis direction of the above-mentioned film I and the polarization absorption axis direction of the polarizing functional layer is 35°, thus obtaining an eye-protecting optical film.

[0062] Example 3 A polarizing film formed of polyvinyl alcohol (PVA) and iodine is provided, and a polarizing film (Derrig, T11-NT) composed of cellulose triacetate is laminated on both sides of the polarizing film. Then, the above-mentioned film I is laminated on one side of the polarizing functional layer, such that the acute angle between the optical slow axis direction of the above-mentioned film I and the polarization absorption axis direction of the polarizing functional layer is 25°, thus obtaining an eye-protecting optical film.

[0063] Example 4 Using the same casting method as in Example 1, the stretching ratio in the MD direction was adjusted to 2.1 times and the stretching ratio in the TD direction was adjusted to 4.5 times. Other aspects remained the same as in Example 1, resulting in a film II with a thickness of 80 μm. The MD and TD directions were marked, and the R0 of the film was measured at a wavelength of 550 nm using a phase difference meter (RETS 100L). The R0 was 8320 nm, and the interpolation Δβ of any ten β values ​​in the TD direction as the reference direction was 10°.

[0064] A polarizing film formed of polyvinyl alcohol (PVA) and iodine is provided, and a polarizing film (Derrig, T11-NT) composed of cellulose triacetate is laminated on both sides of the polarizing film. Then, the above-mentioned film II is laminated on one side of the polarizing functional layer, such that the acute angle between the optical slow axis direction of the above-mentioned film II and the polarization absorption axis direction of the polarizing functional layer is 45°, thus obtaining an eye-protecting optical film.

[0065] Example 5 Using the same casting method as in Example 1, the stretching ratio in the MD direction was adjusted to 1.7 times and the stretching ratio in the TD direction was adjusted to 4 times. Other aspects remained the same as in Example 1, resulting in a film III with a thickness of 89 μm. The MD and TD directions were marked, and the R0 of the film was measured at a wavelength of 550 nm using a phase difference meter (RETS 100L). The R0 was 10215 nm, and the interpolation Δβ of any ten β values ​​in the TD direction as the reference direction was 15°, thus obtaining an eye-protecting optical film.

[0066] A polarizing film formed of polyvinyl alcohol (PVA) and iodine is provided, and a polarizing film (Derrig, T11-NT) composed of cellulose triacetate is laminated on both sides of the polarizing film. Then, the above-mentioned film III is laminated on one side of the polarizing functional layer, such that the acute angle between the optical slow axis direction of the above-mentioned film III and the polarization absorption axis direction of the polarizing functional layer is 45°, thus obtaining an eye-protecting optical film.

[0067] Example 6 Casting was performed using the same method as in Example 1, with the stretching ratio in the MD direction adjusted to 3 times and the stretching ratio in the TD direction adjusted to 5.1 times. Other aspects remained the same as in Example 1, resulting in a film IV with a thickness of 75 μm. The MD and TD directions were marked, and the R0 of the film was measured at a wavelength of 550 nm using a phase difference meter (RETS 100L). The R0 was 9100 nm, and the interpolation Δβ of any ten β values ​​in the TD direction as the reference direction was 20°.

[0068] A polarizing film formed of polyvinyl alcohol (PVA) and iodine is provided, and a polarizing film (Derrig, T11-NT) composed of cellulose triacetate with polarizing function is laminated on both sides of the polarizing film. Then, the above-mentioned film IV is laminated on one side of the polarizing functional layer, such that the acute angle between the optical slow axis direction of the above-mentioned film IV and the polarization absorption axis direction of the polarizing functional layer is 45°, thus obtaining an eye-protecting optical film.

[0069] Example 7 Casting was performed using the same method as in Example 1, with the stretching ratio in the MD direction adjusted to 3 times and the stretching ratio in the TD direction adjusted to 4.3 times. Other aspects remained the same as in Example 1, resulting in a thin film V with a thickness of 75 μm. The MD and TD directions were marked, and the R0 of the thin film was measured at a wavelength of 550 nm using a phase difference meter (RETS 100L). The R0 was 2980 nm, and the interpolation Δβ of any ten β values ​​with the TD direction as the reference direction was 7°.

[0070] A polarizing film formed of polyvinyl alcohol (PVA) and iodine is provided, and a polarizing film (Derrig, T11-NT) composed of cellulose triacetate is laminated on both sides of the polarizing film. Then, the above-mentioned film V is laminated on one side of the polarizing functional layer, such that the acute angle between the optical slow axis direction of the above-mentioned film V and the polarization absorption axis direction of the polarizing functional layer is 20°, thus obtaining an eye-protecting optical film.

[0071] Comparative Example 1 Casting was performed using the same method as in Example 1, with the stretching ratio in the MD direction adjusted to 3.1 times and the stretching ratio in the TD direction adjusted to 3.6 times. Other aspects remained the same as in Example 1, resulting in a thin film VI with a thickness of 98 μm. The MD and TD directions were marked, and the R0 of the thin film was measured at a wavelength of 550 nm using a phase difference meter (RETS 100L). The R0 was 4420 nm, and the interpolation Δβ for any ten β values ​​with the TD direction as the reference direction was 23°.

[0072] A polarizing film formed of polyvinyl alcohol (PVA) and iodine is provided, and a polarizing film (Derrig, T11-NT) composed of cellulose triacetate with polarizing function is laminated on both sides of the polarizing film. Then, the above-mentioned film VI is laminated on one side of the polarizing functional layer, such that the acute angle between the optical slow axis direction of the above-mentioned film VI and the polarization absorption axis direction of the polarizing functional layer is 45°, thus obtaining an eye-protecting optical film.

[0073] Comparative Example 2 The antipolarization functional film and the eye-protection optical film were prepared using the same method as in Example 1, with the antipolarization functional film positioned close to the light source, and the antipolarization effect was verified.

[0074] Comparative Example 3 A polarizing film formed of polyvinyl alcohol (PVA) and iodine is provided, and a polarizing film (Derrig, T11-NT) composed of cellulose triacetate with polarizing function is laminated on both sides of the polarizing film. Then, the above-mentioned film I is laminated on one side of the polarizing functional layer, such that the acute angle between the optical slow axis direction of the above-mentioned film I and the polarization absorption axis direction of the polarizing functional layer is 10°, thus obtaining an eye-protecting optical film.

[0075] The polarizer rotation method was used to verify the anti-polarization effect of the above-mentioned spectacle lenses. The details are as follows: Using a white LED light source (JS-KBL180-180) as the backlight, the aforementioned eye-protection optical film was placed above the light source with the polarizing functional layer closer to the light source side (except for Comparative Example 2). Another polarizer (Derrig, T11-NT) was placed above the eye-protection optical film, and the polarizer was rotated to observe the brightness through the eye-protection optical film. The results observed visually were graded according to the following criteria: ○: When the polarizer is rotated 360°, the light intensity passing through the eye-protecting optical film and polarizer does not change significantly, and the colorless film remains white; △: Rotating the polarizer 360° will show two slight changes in light intensity or a slight color shift, but it should not affect the field of view; ×: Rotating the polarizer 360° will reveal significant changes in light intensity or a noticeable color shift.

[0076] The test results are shown in Table 1.

[0077] Table 1 Verification of polarization reduction effect

[0078] As can be seen from Table 1, the antipolarization functional film (layer) and eye-protecting optical film prepared in Examples 1 to 7 can all achieve the antipolarization effect, filter glare, and convert linearly polarized light into unpolarized light.

[0079] In summary, the eye-protecting optical film provided in this application achieves the glare filtering function of traditional polarized glasses through a polarization functional layer, ensuring visual clarity in outdoor and driving scenarios. Simultaneously, by adding an anti-polarization functional layer on the side closest to the wearer's eyes, linearly polarized light is converted into unpolarized light that strikes the retina, avoiding continuous stimulation of the eyes by light from a single polarization direction. This fundamentally alleviates eye fatigue, reduces the risk of drowsiness, and improves safety. Furthermore, the anti-polarization functional layer does not affect the lens's light transmittance or visual clarity and effectively improves eye discomfort during long-term wear, enhancing the wearing experience. Moreover, the eye-protecting optical film provided in this application only requires adding an anti-polarization film structure to a traditional polarized lens, eliminating the need for large-scale modifications to existing eyewear production equipment. It boasts strong production process compatibility and facilitates mass production and widespread adoption.

[0080] The above description is merely an exemplary embodiment of this application and does not limit the patent scope of this application. Any equivalent structural transformations made based on the technical concept of this application and the contents of the specification and drawings of this application, or direct / indirect applications in other related technical fields, are included within the patent protection scope of this application.

Claims

1. A deskewing film characterized in that, The depolarization film is arranged on the light-emitting side of the optical device with polarization function, and is used to convert linearly polarized light formed by the optical device with polarization function into non-polarized light. An acute angle between the direction of the optical slow axis of the depolarization film and the direction of the polarization absorption axis of the optical device with polarization function is 15-45°.

2. The deskewing film of claim 1, wherein, The angle deviation of the optical slow axis is 0-20°.

3. The deskewing film of claim 1, wherein The in-plane retardation value of the depolarization functional layer is not less than 2000 nm. Preferably, the in-plane retardation value of the depolarization functional layer is 6000-20000 nm.

4. An eyecare optical film, characterized by, The optical film comprises a polarization functional layer and a depolarization functional layer arranged in a stack, and the depolarization functional layer comprises the depolarization film according to any one of claims 1-3. The depolarization functional layer is arranged on the side of the polarization functional layer close to the observer's eye, and an acute angle between the direction of the optical slow axis of the depolarization functional layer and the direction of the polarization absorption axis of the polarization functional layer is 15-45°.

5. The eyecare optical film according to claim 4, wherein An acute angle between the direction of the optical slow axis of the depolarization functional layer and the direction of the polarization absorption axis of the polarization functional layer is 25-45°.

6. The eyecare optical film according to claim 4, wherein The degree of polarization of the polarization functional layer is 20-48%. Preferably, the degree of polarization of the polarization functional layer is 25-45%.

7. The eyecare optical film according to claim 5, wherein The polarization functional layer is provided with a protective layer on each side, and the light transmittance of the protective layer is not less than 87%.

8. The eyecare optical film according to claim 7, wherein The protective layer is made of at least one of the following raw materials: triacetate cellulose, cyclic olefin polymer, polymethyl methacrylate.

9. A method of producing the eyecare optical film according to any one of claims 4 to 8, characterized by, Providing polyethylene terephthalate raw material, adding opening agent therein, forming a multi-layer casting sheet comprising at least a core layer and a surface layer by melt co-extrusion; performing bidirectional stretching and heat setting treatment on the multi-layer casting sheet to obtain a depolarization functional film; Providing a polarization functional layer, adhering the depolarization functional film to one side of the polarization functional layer, and making an acute angle between the direction of the slow axis of the depolarization functional film and the direction of the polarization absorption axis of the polarization functional layer be 15-45°. The optical film comprises the depolarization film according to any one of claims 1-3 or the eye protection optical film according to any one of claims 4-8.

10. A wearable optical device, comprising: ​

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