Optical film and optical system

Abstract

An optical system includes a display and an optical film. For substantially collimated incident light, a red wavelength range extending from about 590 nm to about 670 nm, a visible wavelength range extending from about 420 nm to about 680 nm, an infrared wavelength range extending from about 850 nm to about 1600 nm, and for at least one of a first in-plane polarization state and a second in-plane polarization state that are orthogonal to each other: for an angle of incidence of less than about 10 degrees, the wavelength range of the red wavelength range extending from about 590 nm to about 670 nm, the wavelength range of the visible wavelength range extending from about 420 nm to about 680 nm, and the wavelength range of the infrared wavelength range extending from about 850 nm to about 1600 nm. The plurality of polymeric microlayers having an average optical transmittance of greater than about 60% in the visible wavelength range and an average optical transmittance of less than about 70% in the infrared wavelength range; and the plurality of polymeric microlayers have an average optical transmittance of greater than about 50% in the red wavelength range for an angle of incidence of at least about 70 degrees.

Description

TECHNICAL FIELD

[0001] The present disclosure relates generally to an optical film, and in particular to an optical system comprising an optical film. BACKGROUND

[0002] In some applications, the optical system comprises an outdoor display. As such, the outdoor display can be exposed to sunlight. Such optical systems comprising outdoor displays can be used in automotive display systems, public information display systems, and the like. SUMMARY

[0003] In a first aspect, the present disclosure provides an optical system. The optical system comprises a display configured to be used outdoors and exposed to sunlight while forming an image for viewing by a viewer. The optical system further comprises an optical film disposed on the display between the viewer and the display. The optical film comprises a plurality of polymeric microlayers having a total number of at least 10. Each polymeric microlayer of the plurality of polymeric microlayers has an average thickness of less than about 500 nm. For substantially collimated incident light, a red wavelength range extending from about 590 nm to about 670 nm, a visible wavelength range extending from about 420 nm to about 680 nm, an infrared wavelength range extending from about 850 nm to about 1600 nm, and for at least one of an in-plane first polarization state and an in-plane second polarization state that are orthogonal to each other: for an incident angle of less than about 10 degrees, the plurality of polymeric microlayers has an average optical transmittance in the visible wavelength range of greater than about 60% and an average optical transmittance in the infrared wavelength range of less than about 70%; and for an incident angle of at least about 70 degrees, the plurality of polymeric microlayers has an average optical transmittance in the red wavelength range of greater than about 50%.

[0004] In a second aspect, the present disclosure provides an optical film configured to be used outdoors and exposed to sunlight. The optical film comprises a plurality of polymeric microlayers having a total number of at least 50. Each polymeric microlayer of the plurality of polymeric microlayers has an average thickness of less than about 500 nm. For substantially collimated substantially normally incident light, and for each of an in-plane first polarization state and an in-plane second polarization state that are orthogonal to each other, the plurality of polymeric microlayers has an average optical transmittance in a visible wavelength range extending from about 420 nm to about 680 nm of greater than about 60% and an average optical transmittance in an infrared wavelength range extending from about 850 nm to about 1600 nm of less than 70%. For substantially collimated light incident on the optical film from a light source D65, the optical film reflects the incident substantially collimated light, wherein the reflected light has colorimetric parameters A and B in the CIE Lab color space such that as the incident angle of the incident substantially collimated light continuously varies from about 0 degrees to about 89 degrees, A TECHNICAL FIELD

[0001] The present disclosure relates generally to an optical film, and in particular to an optical system comprising an optical film. BACKGROUND

[0002] In some applications, the optical system comprises an outdoor display. As such, the outdoor display can be exposed to sunlight. Such optical systems comprising outdoor displays can be used in automotive display systems, public information display systems, and the like. SUMMARY

[0003] In a first aspect, the present disclosure provides an optical system. The optical system comprises a display configured to be used outdoors and exposed to sunlight while forming an image for viewing by a viewer. The optical system further comprises an optical film disposed on the display between the viewer and the display. The optical film comprises a plurality of polymeric microlayers having a total number of at least 10. Each polymeric microlayer of the plurality of polymeric microlayers has an average thickness of less than about 500 nm. For substantially collimated incident light, a red wavelength range extending from about 590 nm to about 670 nm, a visible wavelength range extending from about 420 nm to about 680 nm, an infrared wavelength range extending from about 850 nm to about 1600 nm, and for at least one of an in-plane first polarization state and an in-plane second polarization state that are orthogonal to each other: for an incident angle of less than about 10 degrees, the plurality of polymeric microlayers has an average optical transmittance in the visible wavelength range of greater than about 60% and an average optical transmittance in the infrared wavelength range of less than about 70%; and for an incident angle of at least about 70 degrees, the plurality of polymeric microlayers has an average optical transmittance in the red wavelength range of greater than about 50%.

[0004] In a second aspect, the present disclosure provides an optical film configured to be used outdoors and exposed to sunlight. The optical film comprises a plurality of polymeric microlayers having a total number of at least 50. Each polymeric microlayer of the plurality of polymeric microlayers has an average thickness of less than about 500 nm. For substantially collimated substantially normally incident light, and for each of an in-plane first polarization state and an in-plane second polarization state that are orthogonal to each other, the plurality of polymeric microlayers has an average optical transmittance in a visible wavelength range extending from about 420 nm to about 680 nm of greater than about 60% and an average optical transmittance in an infrared wavelength range extending from about 850 nm to about 1600 nm of less than 70%. For substantially collimated light incident on the optical film from a light source D65, the optical film reflects the incident substantially collimated light, wherein the reflected light has colorimetric parameters A and B in the CIE Lab color space such that as the incident angle of the incident substantially collimated light continuously varies from about 0 degrees to about 89 degrees, A It remains within a first range extending from approximately -5 to approximately 4, and B It remains within the second range, extending from approximately -7 to approximately 4.

[0005] Details of one or more examples of this disclosure are set forth in the accompanying drawings and the following description. Other features, objects, and advantages of this disclosure will become apparent from the description, the drawings, and the claims. Attached Figure Description

[0006] The exemplary embodiments disclosed herein can be more fully understood in light of the following detailed description taken in conjunction with the accompanying drawings. The drawings are not necessarily drawn to scale. Similar numbers used in the drawings refer to similar components. However, it should be understood that the use of numbers to refer to parts in a given drawing is not intended to limit parts labeled with the same numbers in another drawing.

[0007] Figure 1 A schematic cross-sectional view of an optical system according to one embodiment of the present disclosure is shown; Figure 2 A schematic detailed cross-sectional view of an optical film according to one embodiment of the present disclosure is shown; Figure 3 A schematic detailed cross-sectional view of an optical film according to another embodiment of the present disclosure is shown; Figure 4 A schematic detailed cross-sectional view of an optical film according to another embodiment of the present disclosure is shown; Figure 5 A schematic cross-sectional view of a plurality of polymer microlayers of an optical film according to one embodiment of the present disclosure is shown; Figure 6 A graph depicting the optical transmittance of a plurality of polymer microlayers of an optical film relative to wavelength for substantially collimated incident light and for a first polarization state is shown according to an embodiment of the present disclosure. Figure 7 A graph depicting the optical transmittance of a plurality of polymer microlayers of an optical film relative to wavelength for substantially collimated incident light and for a second polarization state is shown according to one embodiment of the present disclosure. Figure 8 A schematic cross-sectional view of an optical film and a light source D65 according to one embodiment of the present disclosure is shown; Figure 9 The illustration shows a depiction of an optical system comprising an optical film according to one embodiment of the present disclosure. A graph relative to the angle of incidence; Figures 10A-10C An illustration of an embodiment of the present disclosure is shown for an optical system including an optical film at different incident angles. With B A graph showing the changes between them; Figure 10D It shows Figures 10A-10C An enlarged view of a portion of the graph shown; Figure 10E It shows Figures 10A-10C An enlarged view of another part of the graph shown; and Figure 10F It shows Figure 10E An enlarged view of a portion of the graph shown. Detailed Implementation

[0008] In the following description, reference is made to the accompanying drawings, which form a part thereof, and various embodiments are illustrated therein. It should be understood that other embodiments may be conceived and made without departing from the scope or spirit of this disclosure. Therefore, the following detailed description should not be considered limiting.

[0009] In the following disclosure, the following definitions are used.

[0010] As used herein, all numbers should be considered as being modified by the term “about”. As used herein, “a,” “an,” “the,” “at least one,” and “a or more” are used interchangeably.

[0011] As used herein, as a modifier of a characteristic or attribute, unless otherwise specifically defined, the term “approximately” means that the characteristic or attribute will be easily identifiable by a person of ordinary skill in the art without requiring absolute precision or a perfect match (e.g., within + / - 20% for quantifiable characteristics).

[0012] Unless otherwise specifically defined, the term “substantially” means a high degree of approximation (e.g., within + / -10% for quantifiable properties), but also does not require absolute precision or a perfect match.

[0013] Unless otherwise specifically defined, the term “approximately” means a high degree of approximation (e.g., within + / -5% for quantifiable properties), but also does not require absolute precision or a perfect match.

[0014] As used herein, the terms “first” and “second” are used as identifiers. Therefore, such terms should not be construed as limiting the scope of this disclosure. Throughout the embodiments of this disclosure, the terms “first” and “second” are interchangeable when used in conjunction with a feature or element.

[0015] As used in this article, "at least one of A and B" should be understood as meaning "only A, only B, or both A and B".

[0016] As used herein, the term "layer" generally refers to the thickness of a material within a membrane that has a relatively uniform chemical composition. A layer can be any type of material, including polymers, cellulose, metals, or blends thereof. A given polymer layer may comprise a single polymer type or a blend of polymers and may include additives. A given layer may be combined with or bonded to other layers to form a membrane. A layer may be partially continuous or completely continuous compared to adjacent layers or membranes. A given layer may be partially or completely co-extended with adjacent layers. A layer may contain sublayers.

[0017] In some applications, the optical system includes an outdoor display. Therefore, the outdoor display may be exposed to sunlight. Such optical systems, including outdoor displays, can be used in automotive display systems, public information display systems, and the like.

[0018] Sunlight incident on an outdoor display of an optical system can cause thermal management problems by heating the display. In some cases, optical films that reflect sunlight in a portion of the infrared wavelength range extending from about 850 nm to about 1600 nm can be used in such optical systems. However, such optical films can also reflect light in a portion of the red wavelength range extending from about 590 nm to about 670 nm, especially at an angle (e.g., greater than about 70 degrees). This can negatively impact the display's color performance and may cause color artifacts.

[0019] Therefore, a suitable solution may be desired that provides better thermal management without compromising the color performance of the optical system in outdoor applications.

[0020] This disclosure relates to an optical system including a display configured for outdoor use and exposure to sunlight, while forming an image for a viewer to see. This disclosure also relates to an optical film configured for outdoor use and exposure to sunlight. The optical system includes the optical film.

[0021] An optical film is disposed on a display, between the viewer and the display, and comprises at least 10 polymer microlayers. Each of the polymer microlayers has an average thickness of less than about 500 nm. For substantially collimated incident light, in a red wavelength range extending from about 590 nm to about 670 nm, in a visible wavelength range extending from about 420 nm to about 680 nm, and in an infrared wavelength range extending from about 850 nm to about 1600 nm, and for at least one of mutually orthogonal in-plane first polarization state and in-plane second polarization state: for an incident angle of less than about 10 degrees, the polymer microlayers have an average optical transmittance greater than about 60% in the visible wavelength range and less than about 70% in the infrared wavelength range; and for an incident angle of at least about 70 degrees, the polymer microlayers have an average optical transmittance greater than about 50% in the red wavelength range.

[0022] Therefore, for the first polarization state and for an incident angle of at least about 70 degrees, the optical film of this disclosure can substantially transmit substantially collimated incident light in the red wavelength range, while providing thermal management for the optical system by reducing the transmission of substantially collimated incident light in the infrared wavelength range having at least one of the first and second polarization states, incident at an incident angle of less than about 10 degrees. This can reduce or prevent visible color artifacts.

[0023] Now refer to the attached diagram, Figure 1 This is a schematic cross-sectional view of an optical system 300 according to one embodiment of the present disclosure.

[0024] The optical system 300 defines mutually orthogonal x-axis, y-axis, and z-axis. The x-axis and y-axis are in-plane axes of the optical system 300, while the z-axis is a transverse axis set along the thickness of the optical system 300. In other words, the x-axis and y-axis are set along the plane of the optical system 300, while the z-axis is perpendicular to the plane of the optical system 300.

[0025] The optical system 300 includes a display 10 configured to display an image 11. The display 10 is configured for outdoor use and exposure to sunlight 20, while forming an image 11 for a viewer 30 to view.

[0026] In some embodiments, the display 10 includes one or more of a liquid crystal display (LCD), an organic light-emitting diode (OLED) display, and a micro-LED display. In some embodiments, the micro-LED display includes a plurality of individual and independently operable micro-LEDs 12.

[0027] The optical system 300 also includes an optical film 40 configured for outdoor use and exposure to sunlight 20. The optical film 40 is disposed on the display 10, between the viewer 30 and the display.

[0028] In some embodiments, the optical system 300 further includes a first substrate layer 60 disposed on the optical film 40 opposite to the display 10. In some embodiments, the first substrate layer 60 comprises one or more of glass and plastic. In some embodiments, the first substrate layer 60 is bonded to the optical film 40 via an adhesive layer 70. In some embodiments, the adhesive layer 70 may comprise an optically transparent adhesive (OCA).

[0029] In some embodiments, the optical system 300 further includes a second substrate layer 61 disposed between the optical film 40 and the display 10. In some embodiments, the second substrate layer 61 comprises one or more of glass and plastic. In some embodiments, the second substrate layer 61 is bonded to the optical film 40 and the display 10 via a first adhesive layer 71 and a second adhesive layer 72. Specifically, the second substrate layer 61 is bonded to the optical film 40 via the first adhesive layer 71, and the second substrate layer 61 is bonded to the display 10 via the second adhesive layer 72. In some embodiments, the optical film 40 may include an optical film 40a (… Figure 2 As shown), optical film 40b ( Figure 3 (as shown) or optical film 40c ( Figure 4 (As shown in the diagram). In some embodiments, each of the first adhesive layer 71 and the second adhesive layer 72 may contain an OCA.

[0030] Figure 2 A schematic detailed cross-sectional view of an optical film 40a according to one embodiment of the present disclosure is illustrated. The optical film 40a can be used as an optical film 40 for... Figure 1 In the optical system 300.

[0031] The optical film 40a includes a plurality of polymer microlayers 43 in total of at least 10. In some embodiments, the optical film 40a includes a plurality of polymer microlayers 43 in total of at least 20, at least 50, at least 100, at least 150, at least 200, at least 250 or 300.

[0032] In some embodiments, the plurality of polymer microlayers 43 includes at least 10 alternating first polymer microlayers 41 and second polymer microlayers 42 stacked along the thickness direction of the optical film 40a. In some embodiments, the plurality of polymer microlayers 43 includes at least 20, 50, 100, 150, 200, 250, or 300 alternating first polymer microlayers 41 and second polymer microlayers 42 stacked along the thickness direction of the optical film 40a. In some embodiments, the plurality of polymer microlayers 43 includes approximately 225 alternating first polymer microlayers 41 and second polymer microlayers 42 stacked along the thickness direction of the optical film 40a. In some embodiments, the thickness direction of the optical film 40a extends substantially along the z-axis.

[0033] Each polymer microlayer in polymer microlayer 43 has an average thickness t of less than about 500 nm. As used herein, the term "average thickness t" refers to the average thickness measured at multiple points across a plane (i.e., the xy plane) of each polymer microlayer in polymer microlayer 43. In some embodiments, each polymer microlayer in polymer microlayer 43 has an average thickness t of less than about 400 nm, less than about 300 nm, or less than about 200 nm. Therefore, each of the first polymer microlayer 41 and the second polymer microlayer 42 may have an average thickness t of less than about 500 nm.

[0034] In some embodiments, the first polymer microlayer 41 comprises polyethylene terephthalate (PET), and the second polymer microlayer 42 comprises a copolymer of polymethyl methacrylate (CoPMMA). In some embodiments, the second polymer microlayer 42 comprises a copolymer of an aliphatic-aromatic polyester for a visible wavelength range 51 extending from about 420 nm to about 680 nm. Figure 6 The second polymer microlayer 42 (as shown) has a refractive index Ri less than 1.52, i.e., Ri < 1.52. In some embodiments, Ri < 1.5. In some embodiments, the second polymer microlayer 42 comprises any suitable material having a refractive index Ri < 1.52 for the visible wavelength range 51 and having an optical transparency Ot greater than or equal to about 80% (i.e., Ot ≥ 80%) and / or an optical haze Oh less than about 1% (i.e., Oh ≤ 1%).

[0035] In some embodiments, the optical film 40a further includes at least one surface layer 46. Each of the at least one surface layer 46 has an average thickness ts greater than about 500 nm. As used herein, the term "average thickness ts" refers to the average thickness measured at multiple points across a plane (i.e., the xy plane) of each of the at least one surface layer 46. In some embodiments, each of the at least one surface layer 46 has an average thickness ts greater than about 750 nm, greater than about 1000 nm, greater than about 1250 nm, greater than about 1500 nm, greater than about 1750 nm, or greater than about 2000 nm. In some embodiments, the at least one surface layer 46 comprises PET.

[0036] exist Figure 2 In an exemplary embodiment, at least one surface layer 46 comprises a pair of surface layers 46, and a polymer microlayer 43 is disposed between the pair of surface layers 46. At least one surface layer 46 protects the polymer microlayer 43 and also provides mechanical stability to the optical film 40a. In some cases, at least one surface layer 46 may act as a protective boundary layer (PBL).

[0037] Figure 3 A schematic detailed cross-sectional view of an optical film 40b according to another embodiment of the present disclosure is illustrated. The optical film 40b can be used as the optical film 40 for... Figure 1 In the optical system 300. Figure 3 The optical film 40b is basically similar to Figure 2 The optical film 40a, wherein common components are referred to by the same numerical symbols.

[0038] exist Figure 3 In an exemplary embodiment, the plurality of polymer microlayers 43 include a plurality of first optical repeating units 44a and a plurality of second optical repeating units 44b.

[0039] In some embodiments, the total number of the plurality of first optical repeating units 44a is at least 10. In some embodiments, the total number of the plurality of first optical repeating units 44a is at least 15, at least 20, at least 50, at least 100, or at least 150.

[0040] In some embodiments, the total number of the plurality of second optical repeating units 44b is at least 10. In some embodiments, the total number of the plurality of second optical repeating units 44b is at least 15, at least 20, at least 50, at least 100, at least 200, at least 250, or at least 300.

[0041] In some embodiments, each of the first optical repeating units 44a has at least a microlayer A1 (in Figure 3 The diagram shows 41a) and microlayer B1 (inFigure 3 These microlayers (shown as 41b) have different compositions. Microlayer A1 may be referred to herein as "microlayer A1 41a", and microlayer B1 may be referred to herein as "microlayer B1 41b". In other words, the composition of at least microlayer A1 41a of each first optical repeating unit 44a is different from the composition of at least microlayer B1 41b of each first optical repeating unit 44a.

[0042] In some embodiments, one of microlayers A1 41a and B1 41b comprises PET, and the other of microlayers A1 41a and B1 41b comprises CoPMMA. In some embodiments, the other of microlayers A1 41a and B1 41b comprises a copolymer of an aliphatic-aromatic polyester, which is effective for visible wavelengths in the 51 nm range. Figure 6 (As shown) has a refractive index Ri < 1.52. In some embodiments, Ri < 1.5. In some embodiments, the other of microlayer A1 41a and microlayer B1 41b comprises any suitable material having a refractive index Ri < 1.52 for the visible wavelength range 51 and having optical transparency Ot ≥ 80% and / or optical haze Oh ≤ 1%.

[0043] In some embodiments, each of the first optical repeating units 44a includes a microlayer in microlayer A1 41a and a microlayer in microlayer B1 41b arranged as A1B1.

[0044] In some embodiments, each of the second optical repeating units 44b has at least a microlayer A2 (in Figure 3 As shown in Figure 42a), microlayer B2 (in Figure 3 The diagram shows 42b) and microlayer C2 (in Figure 3 These microlayers (shown as 42c) have different compositions. Microlayer A2 may be referred to herein as "microlayer A2 42a", microlayer B2 may be referred to herein as "microlayer B2 42b", and microlayer C2 may be referred to herein as "microlayer C2 42c". In some embodiments, at least one of microlayers A1 41a and B1 41b has a composition different from at least one of microlayers A2 42a, B2 42b, and C2 42c.

[0045] In some embodiments, the first microlayer of microlayers A2 42a, B2 42b, and C2 42c comprises PET, the second microlayer of microlayers A2 42a, B2 42b, and C2 42c comprises CoPMMA, and the third microlayer of microlayers A2 42a, B2 42b, and C2 42c comprises ethylene glycol-modified polyethylene terephthalate (PETg).

[0046] In some embodiments, the second microlayer of microlayers A2 42a, B2 42b, and C2 42c comprises a copolymer of an aliphatic-aromatic polyester, which is effective for visible wavelengths in the 51 nm range. Figure 6 (As shown) has a refractive index Ri < 1.52. In some embodiments, Ri < 1.5. In some embodiments, the second microlayer of microlayers A2 42a, B2 42b, and C2 42c comprises any suitable material having a refractive index Ri < 1.52 for the visible wavelength range 51 and having optical transparency Ot ≥ 80% and / or optical haze Oh ≤ 1%.

[0047] In some embodiments, the third microlayer of microlayers A2 42a, B2 42b, and C2 42c comprises a material having a refractive index Ric of less than about 1.6 for the visible wavelength range 51 (i.e., Ric < 1.6) and having optical transparency ≥ 80% and / or optical haze ≤ 1% ohm. In some embodiments, Ric < 1.58 or Ric < 1.57.

[0048] Each of the microlayers 41a, 41b, 42a, 42b, 42c in the first optical repeating unit 44a and the second optical repeating unit 44b has an average thickness t of less than about 500 nm. In some embodiments, each of the microlayers 41a, 41b, 42a, 42b, 42c in the first optical repeating unit 44a and the second optical repeating unit 44b has an average thickness t of less than about 450 nm, less than about 400 nm, less than about 350 nm, less than about 300 nm, less than about 250 nm, or less than about 200 nm.

[0049] In some embodiments, a plurality of first optical repeating units 44a are disposed on at least one spacer layer 45 and spaced apart from a plurality of second optical repeating units 44b by the at least one spacer layer. Figure 3 In an exemplary embodiment, a plurality of first optical repeating units 44a are disposed on a spacer layer 45 and separated from a plurality of second optical repeating units 44b by the spacer layer.

[0050] Additionally, in some embodiments, each spacer layer in at least one spacer layer 45 has an average thickness tsl greater than about 500 nm. In some embodiments, each spacer layer in at least one spacer layer 45 has an average thickness tsl greater than about 400 nm, greater than about 300 nm, or greater than about 200 nm.

[0051] In some embodiments, each of the second optical repeating units 44b includes one microlayer in microlayer A2 42a, two microlayers in microlayer B2 42b, and one microlayer in microlayer C2 42c arranged as A2B2C2B2.

[0052] Figure 4 A schematic detailed cross-sectional view of an optical film 40c according to another embodiment of the present disclosure is illustrated. The optical film 40c can be used as the optical film 40 for... Figure 1 In the optical system 300. Figure 4 The optical film 40c is basically similar to Figure 3 The optical film 40b, wherein common components are referred to by the same numerical symbols. However, Figure 4 The optical film 40c does not include Figure 3 The first optical repeating unit 44a and at least one spacer layer 45 are shown.

[0053] Therefore, in Figure 4 In an exemplary embodiment, the plurality of polymer microlayers 43 include a plurality of optical repeating units 44b (previously referred to as "second optical repeating units 44b"). The total number of the plurality of second optical repeating units 44b is at least 10. In some embodiments, the total number of the plurality of optical repeating units 44b is at least 15, at least 20, at least 50, at least 100, at least 200, at least 250, or at least 300. Each optical repeating unit in the optical repeating unit 44b has at least microlayers A2 42a, B2 42b, and C2 42c, which have different compositions. In some embodiments, each optical repeating unit in the optical repeating unit 44b includes one microlayer in microlayer A2 42a, two microlayers in microlayer B2 42b, and one microlayer in microlayer C2 42c arranged as A2B2C2B2.

[0054] As discussed above, in some embodiments, the first microlayer of microlayers A2 42a, B2 42b and C2 42c contains PET, the second microlayer of microlayers A2 42a, B2 42b and C2 42c contains CoPMMA, and the third microlayer of microlayers A2 42a, B2 42b and C2 42c contains PETg.

[0055] In some embodiments, the second microlayer of microlayers A2 42a, B2 42b, and C2 42c comprises a copolymer of an aliphatic-aromatic polyester, which is effective for visible wavelengths in the 51 nm range. Figure 6 (As shown) has a refractive index Ri < 1.52. In some embodiments, Ri < 1.5. In some embodiments, the second microlayer of microlayers A2 42a, B2 42b, and C2 42c comprises any suitable material having a refractive index Ri < 1.52 for the visible wavelength range 51 and having optical transparency Ot ≥ 80% and / or optical haze Oh ≤ 1%.

[0056] In some embodiments, the third microlayer of microlayers A2 42a, B2 42b, and C2 42c comprises a material having a refractive index Ric of less than about 1.6 for the visible wavelength range 51 (i.e., Ric < 1.6) and having optical transparency ≥ 80% and / or optical haze ≤ 1% ohm. In some embodiments, Ric < 1.58 or Ric < 1.57.

[0057] Figure 5 An optical film 40 according to one embodiment of the present disclosure is illustrated. Figure 1 A schematic cross-sectional view of multiple polymer microlayers 43 (shown). Multiple polymer microlayers 43 in... Figure 5 It is schematically shown as a single box.

[0058] like Figure 5 As shown, a plurality of polymer microlayers 43 are configured to receive substantially collimated incident light 31. In some embodiments, the plurality of polymer microlayers 43 receive substantially collimated incident light 31 at an incident angle α1.

[0059] In some embodiments, the angle of incidence α1 is less than about 10 degrees. In some embodiments, the angle of incidence α1 is less than about 8 degrees, less than about 6 degrees, less than about 4 degrees, less than about 2 degrees, or less than about 1 degree. In some embodiments, the angle of incidence α1 is about 0 degrees.

[0060] In some other embodiments, the angle of incidence a1 is at least about 70 degrees. In some embodiments, the angle of incidence a1 is at least about 75 degrees or at least about 80 degrees. In some embodiments, the angle of incidence a1 is about 80 degrees.

[0061] Figure 6 An illustration of one embodiment of this disclosure is provided for substantially collimated incident light 31 ( Figure 5 (as shown) and for the first polarization state, optical films 40a, 40b, 40c ( Figure 2 , Figure 3 and Figure 4The graph 600 shows the optical transmittance of multiple polymer microlayers 43 relative to wavelength (as shown separately). Additionally, the graph 600 depicts the optical transmittance of a substantially collimated incident light 31 (…). Figure 5 (As shown) and for the first polarization state, the optical transmittance of the optical film relative to the wavelength is compared. In some embodiments, the first polarization state is a p-polarization state. In some embodiments, the first polarization state is along the x-axis.

[0062] Wavelength is expressed in nanometers (nm) on the horizontal axis. Optical transmittance is expressed as a percentage (%) on the vertical axis.

[0063] Graph 600 includes: curve 602, which depicts the optical transmittance of optical film 40a for an incident angle a1 less than about 10 degrees and for a first polarization state; curve 604, which depicts the optical transmittance of optical film 40b for an incident angle a1 less than about 10 degrees and for a first polarization state; and curve 606, which depicts the optical transmittance of optical film 40c for an incident angle a1 less than about 10 degrees and for a first polarization state. Graph 600 also includes curve 608, which depicts the optical transmittance of a comparative optical film for an incident angle a1 less than about 10 degrees and for a first polarization state. Specifically, curves 602, 604, 606, and 608 depict the optical transmittance of optical films 40a, 40b, 40c, and the comparative optical film, respectively, for an incident angle a1 of about 0 degrees and for a first polarization state.

[0064] Graph 600 further includes: curve 612, which depicts the optical transmittance of optical film 40a for an incident angle a1 of at least about 70 degrees and for a first polarization state; curve 614, which depicts the optical transmittance of optical film 40b for an incident angle a1 of at least about 70 degrees and for a first polarization state; and curve 616, which depicts the optical transmittance of optical film 40c for an incident angle a1 of at least about 70 degrees and for a first polarization state. Graph 600 also includes curve 618, which depicts the optical transmittance of a comparative optical film for an incident angle a1 of at least about 70 degrees and for a first polarization state. Specifically, curves 612, 614, 616, and 618 depict the optical transmittance of optical films 40a, 40b, 40c, and the comparative optical film for an incident angle a1 of about 80 degrees and for a first polarization state, respectively.

[0065] Figure 7 An illustration of one embodiment of this disclosure is provided for substantially collimated incident light 31 ( Figure 5 (as shown) and for the second polarization state, optical films 40a, 40b, 40c ( Figure 2 , Figure 3 and Figure 4The graph 700 shows the optical transmittance of multiple polymer microlayers 43 relative to wavelength (as shown separately). Additionally, the graph 700 depicts the optical transmittance of a substantially collimated incident light 31 (…). Figure 5 (As shown) and for the second polarization state, the optical transmittance of the optical film relative to the wavelength is compared. In some embodiments, the second polarization state is an s-polarization state. In some embodiments, the second polarization state is along the y-axis.

[0066] Wavelength is expressed in nanometers (nm) on the horizontal axis. Optical transmittance is expressed as a percentage (%) on the vertical axis.

[0067] Graph 700 includes: curve 702, which depicts the optical transmittance of optical film 40a for an incident angle a1 less than about 10 degrees and for a second polarization state; curve 704, which depicts the optical transmittance of optical film 40b for an incident angle a1 less than about 10 degrees and for a second polarization state; and curve 706, which depicts the optical transmittance of optical film 40c for an incident angle a1 less than about 10 degrees and for a second polarization state. Graph 700 also includes curve 708, which depicts the optical transmittance of a comparative optical film for an incident angle a1 less than about 10 degrees and for a second polarization state. Specifically, curves 702, 704, 706, and 708 depict the optical transmittance of optical films 40a, 40b, 40c, and the comparative optical film for an incident angle a1 of about 0 degrees and for a second polarization state, respectively.

[0068] Graph 700 further includes: curve 712, which depicts the optical transmittance of optical film 40a for an incident angle a1 of at least about 70 degrees and for a second polarization state; curve 714, which depicts the optical transmittance of optical film 40b for an incident angle a1 of at least about 70 degrees and for a second polarization state; and curve 716, which depicts the optical transmittance of optical film 40c for an incident angle a1 of at least about 70 degrees and for a second polarization state. Graph 700 also includes curve 718, which depicts the optical transmittance of a comparative optical film for an incident angle a1 of at least about 70 degrees and for a second polarization state. Specifically, curves 712, 714, 716, and 718 depict the optical transmittance of optical films 40a, 40b, 40c, and the comparative optical film for an incident angle a1 of about 80 degrees and for a second polarization state, respectively.

[0069] refer to Figure 5 , Figure 6 and Figure 7For substantially collimated incident light 31, a red wavelength range 50 extending from about 590 nm to about 670 nm, a visible wavelength range 51 extending from about 420 nm to about 680 nm, and an infrared wavelength range 52 extending from about 850 nm to about 1600 nm, and for at least one of mutually orthogonal in-plane first polarization state and in-plane second polarization state, for an incident angle α1 of less than about 10 degrees (described by curves 602, 604, 606, 702, 704, 706), the plurality of polymer microlayers 43 have an average optical transmittance greater than about 60% in the visible wavelength range 51.

[0070] In some embodiments, for substantially collimated incident light 31, red wavelength range 50, visible wavelength range 51, infrared wavelength range 52, and for at least one of a first polarization state and a second polarization state, for an incident angle α1 of less than about 10 degrees, the plurality of polymer microlayers 43 have an average optical transmittance greater than about 65%, greater than about 70%, greater than about 75%, greater than about 80%, or greater than about 85% in the visible wavelength range 51.

[0071] In some embodiments, for substantially collimated, substantially perpendicular incident light 31, and for each of mutually orthogonal in-plane first polarization state and in-plane second polarization state, the plurality of polymer microlayers 43 have an average optical transmittance greater than about 60% in the visible wavelength range 51.

[0072] As can be seen from curves 602, 604, and 606, for substantially collimated incident light 31, for the first polarization state, and for an incident angle a1 of approximately 0 degrees, the multiple polymer microlayers 43 of optical films 40a, 40b, and 40c have corresponding average optical transmittances of approximately 87.9%, 87.9%, and 88.1% in the visible wavelength range 51.

[0073] Furthermore, as is evident from curves 702, 704, and 706, for substantially collimated incident light 31, for the second polarization state, and for an incident angle a1 of approximately 0 degrees, the multiple polymer microlayers 43 of optical films 40a, 40b, and 40c have corresponding average optical transmittances of approximately 87.6%, 86.7%, and 86.8% in the visible wavelength range 51.

[0074] Therefore, for substantially collimated incident light 31, for each of the mutually orthogonal in-plane first polarization state and in-plane second polarization state, and for an incident angle α1 of less than about 10 degrees, the plurality of polymer microlayers 43 of each of the optical films 40a, 40b, 40c have an average optical transmittance of more than about 60% in the visible wavelength range 51.

[0075] In some embodiments, for each of the mutually orthogonal in-plane first polarization state and in-plane second polarization state, and for an incident angle α1 of less than about 10 degrees, the plurality of polymer microlayers 43 have an average optical transmittance greater than about 65%, greater than about 70%, greater than about 75%, greater than about 80%, or greater than about 85% in the visible wavelength range 51.

[0076] Furthermore, for substantially collimated incident light 31, and for at least one of mutually orthogonal in-plane first polarization state and in-plane second polarization state, for an incident angle α1 of less than about 10 degrees, the plurality of polymer microlayers 43 have an average optical transmittance of less than 70% in the infrared wavelength range 52.

[0077] In some embodiments, for substantially collimated incident light 31, and for at least one of mutually orthogonal in-plane first polarization state and in-plane second polarization state, for an incident angle α1 of less than about 10 degrees, the plurality of polymer microlayers 43 have an average optical transmittance of less than about 65%, less than about 60%, less than about 55%, less than about 50%, less than about 45%, less than about 40%, or less than about 35% in the infrared wavelength range 52.

[0078] In some embodiments, for substantially collimated, substantially perpendicular incident light 31, and for each of mutually orthogonal in-plane first polarization state and in-plane second polarization state, the plurality of polymer microlayers 43 have an average optical transmittance of less than about 70% in the infrared wavelength range 52.

[0079] As can be seen from curves 602, 604, and 606, for substantially collimated incident light 31, for the first polarization state, and for an incident angle a1 of approximately 0 degrees, the multiple polymer microlayers 43 of optical films 40a, 40b, and 40c have corresponding average optical transmittances of approximately 59.2%, 31.4%, and 44.1% in the infrared wavelength range 52.

[0080] Furthermore, as is evident from curves 702, 704, and 706, for substantially collimated incident light 31, for the second polarization state, and for an incident angle a1 of approximately 0 degrees, the multiple polymer microlayers 43 of optical films 40a, 40b, and 40c have corresponding average optical transmittances of approximately 57%, 23.9%, and 34.9% in the infrared wavelength range 52.

[0081] Therefore, for substantially collimated incident light 31, for each of the mutually orthogonal in-plane first polarization state and in-plane second polarization state, and for an incident angle a1 of less than about 10 degrees, the plurality of polymer microlayers 43 of each of the optical films 40a, 40b, 40c have an average optical transmittance of less than about 70% in the infrared wavelength range 52.

[0082] Furthermore, for substantially collimated incident light 31, red wavelength range 50, visible wavelength range 51, infrared wavelength range 52, and for at least one of mutually orthogonal in-plane first polarization state and in-plane second polarization state, for an incident angle a1 of at least about 70 degrees, the plurality of polymer microlayers 43 have an average optical transmittance greater than about 50% in the red wavelength range 50.

[0083] In some embodiments, for substantially collimated incident light 31, red wavelength range 50, visible wavelength range 51, infrared wavelength range 52, and for at least one of mutually orthogonal in-plane first polarization state and in-plane second polarization state, for an incident angle α1 of at least about 70 degrees, the plurality of polymer microlayers 43 have an average optical transmittance greater than about 55%, greater than about 60%, or greater than about 65% in the red wavelength range 50.

[0084] As can be seen from curves 612, 614, and 616, for substantially collimated incident light 31, for the first polarization state, and for an incident angle a1 of approximately 80 degrees, the multiple polymer microlayers 43 of optical films 40a, 40b, and 40c have corresponding average optical transmittances of approximately 65.4%, 51.7%, and 53.2% in the red wavelength range 50.

[0085] Therefore, for substantially collimated incident light 31, for a first polarization state, and for an incident angle a1 of at least about 70 degrees, the plurality of polymer microlayers 43 of each of the optical films 40a, 40b, 40c have an average optical transmittance greater than about 50% in the red wavelength range 50. Thus, for the first polarization state and for an incident angle a1 of at least about 70 degrees, the optical films 40a, 40b, 40c can substantially transmit substantially collimated incident light 31 in the red wavelength range 50.

[0086] Conversely, as is evident from curve 618, for substantially collimated incident light 31, for the first polarization state, and for an incident angle a1 of approximately 80 degrees, the comparator optical film has an average optical transmittance of approximately 46% within the red wavelength range 50. Therefore, for the first polarization state and for an incident angle a1 of at least approximately 70 degrees, the comparator optical film substantially blocks substantially collimated incident light 31 within the red wavelength range 50.

[0087] This may affect viewers 30 ( Figure 1(As shown) Colors viewed at an incident angle a1 of at least about 70 degrees. Since optical films 40a, 40b, and 40c can substantially transmit substantially collimated incident light 31 within the red wavelength range 50 for the first polarization state and for an incident angle a1 of at least about 70 degrees, optical films 40a, 40b, and 40c can exhibit good color performance at larger angles (i.e., at least about 70 degrees). This also reduces or prevents visible color artifacts.

[0088] In some embodiments, for at least one of mutually orthogonal in-plane first polarization state and in-plane second polarization state, and for an incident angle a1 of at least about 70 degrees, the plurality of polymer microlayers 43 have an average optical transmittance of less than about 20% in the infrared wavelength range 52.

[0089] In some embodiments, for at least one of mutually orthogonal in-plane first polarization state and in-plane second polarization state, and for an incident angle α1 of at least about 70 degrees, the plurality of polymer microlayers 43 have an average optical transmittance of less than about 15% or less than about 10% in the infrared wavelength range 52.

[0090] As is evident from curves 714 and 716, for substantially collimated incident light 31, for the second polarization state, and for an incident angle α1 of approximately 80 degrees, the plurality of polymer microlayers 43 of optical films 40b and 40c have corresponding average optical transmittances of approximately 7.6% and 8.4% in the infrared wavelength range 52. Therefore, for substantially collimated incident light 31, for the second polarization state, and for an incident angle α1 of at least approximately 70 degrees, the plurality of polymer microlayers 43 of each of the optical films 40b and 40c have an average optical transmittance of less than approximately 20% in the infrared wavelength range 52.

[0091] Conversely, as is evident from curve 718, for substantially collimated incident light 31, for the second polarization state, and for an incident angle a1 of approximately 80 degrees, the comparative optical film has an average optical transmittance greater than approximately 20% (i.e., 22.8%) in the infrared wavelength range 52.

[0092] Therefore, for the second polarization state and for an incident angle a1 of at least about 70 degrees, optical films 40b and 40c can block more substantially collimated incident light 31 within the infrared wavelength range 52 compared to the comparative optical film. Thus, for the second polarization state and for an incident angle a1 of at least about 70 degrees, optical films 40b and 40c provide improved solar reflectivity and consequently better thermal management compared to the comparative optical film.

[0093] In some embodiments, for substantially collimated incident light 31, an ultraviolet (UV) wavelength range 58 extending from about 350 nm to about 400 nm, and for an incident angle α1 of less than about 10 degrees, the plurality of polymer microlayers 43 have an average optical transmittance of less than about 30% for a first polarization state. In some embodiments, for substantially collimated incident light 31, a UV wavelength range 58, and for an incident angle α1 of less than about 10 degrees, the plurality of polymer microlayers 43 have an average optical transmittance of less than about 25% for a first polarization state.

[0094] As can be seen from curves 602 and 604, for substantially collimated incident light 31, UV wavelength range 58, for the first polarization state, and for an incident angle a1 of about 0 degrees, the multiple polymer microlayers 43 of optical films 40a and 40b have corresponding average optical transmittances of about 23.2% and 27.5%.

[0095] In some embodiments, for substantially collimated incident light 31, UV wavelength range 58, and for an incident angle α1 of less than about 10 degrees, the plurality of polymer microlayers 43 have an average optical transmittance of less than about 20% for the second polarization state. In some embodiments, for substantially collimated incident light 31, UV wavelength range 58, and for an incident angle α1 of less than about 10 degrees, the plurality of polymer microlayers 43 have an average optical transmittance of less than about 15% for the second polarization state.

[0096] As can be seen from curves 702 and 704, for substantially collimated incident light 31, UV wavelength range 58, for the second polarization state, and for an incident angle a1 of about 0 degrees, the multiple polymer microlayers 43 of optical films 40a and 40b have corresponding average optical transmittances of about 11.8% and 16.4%.

[0097] In some embodiments, for substantially collimated incident light 31, UV wavelength range 58, and for an incident angle a1 of at least about 70 degrees, the plurality of polymer microlayers 43 have an average optical transmittance of less than about 30% for the second polarization state. In some embodiments, for substantially collimated incident light 31, UV wavelength range 58, and for an incident angle a1 of at least about 70 degrees, the plurality of polymer microlayers 43 have an average optical transmittance of less than about 25% for the second polarization state.

[0098] As can be seen from curves 712, 714, and 716, for substantially collimated incident light 31, UV wavelength range 58, for the second polarization state, and for an incident angle a1 of approximately 80 degrees, the multiple polymer microlayers 43 of optical films 40a, 40b, and 40c have corresponding average optical transmittances of approximately 22.1%, 23.1%, and 22%.

[0099] Therefore, for the first polarization state, optical films 40a, 40b, and 40c can substantially block substantially collimated incident light 31 within the UV wavelength range 58. Additionally, for an incident angle a1 of approximately 80 degrees and for the second polarization state, optical films 40a, 40b, and 40c can substantially block substantially collimated incident light 31 within the UV wavelength range 58. This prevents and / or reduces the arrival of substantially collimated incident light 31 within the UV wavelength range 58. Figure 1 Viewer 30 is shown.

[0100] Table 1 below shows the optical film 40a ( Figure 2 The average optical transmittance of multiple polymer microlayers 43 (as shown) for different wavelength ranges, different values ​​of incident angle a1, and different polarization states.

[0101]

[0102] Table 2 below shows the optical film 40b ( Figure 3 The average optical transmittance of multiple polymer microlayers 43 (as shown) for different wavelength ranges, different values ​​of incident angle a1, and different polarization states.

[0103]

[0104] Table 3 below shows the optical film 40c ( Figure 4 The average optical transmittance of multiple polymer microlayers 43 (as shown) for different wavelength ranges, different values ​​of incident angle a1, and different polarization states.

[0105]

[0106] Table 4 below shows the average optical transmittance of multiple polymer microlayers 43 of the comparative optical film for different wavelength ranges, different values ​​of incident angle α1, and different polarization states.

[0107]

[0108] Where TP0 refers to the average optical transmittance for an incident angle a1 of approximately 0 degrees and for the first polarization state; TS0 refers to the average optical transmittance for an incident angle a1 of approximately 0 degrees and for the second polarization state; TP80 refers to the average optical transmittance for an incident angle α1 of approximately 80 degrees and for the first polarization state; and TS80 refers to the average optical transmittance for an incident angle a1 of approximately 80 degrees and for the second polarization state.

[0109] Figure 8A schematic cross-sectional view of an optical film 40 and a light source D65 33 according to one embodiment of the present disclosure is shown. Figure 8 As shown, substantially collimated light 32 is incident on optical film 40 from light source D65 33 at an incident angle a2. The substantially collimated light 32 is reflected from optical film 40 as reflected light 34.

[0110] Figure 9 A depiction of one embodiment according to this disclosure is shown, comprising an optical film 40 ( Figure 8 The optical system 300 (shown) has a ΔC Relative to the incident angle a2 ( Figure 8 The curve (shown) is 90°. Angles are expressed in degrees (deg) on ​​the horizontal axis. ΔC Expressed on the vertical axis.

[0111] Graph 900 includes curve 902, which depicts ΔC for an incident angle α2, of an optical system 300 including an optical film 40a. Curve 904 depicts the ΔC of the optical system 300, including the optical film 40b, for an incident angle a2. ; and curve 906, which depicts ΔC for an incident angle α2, including the optical system 300 with optical film 40c. Graph 900 also includes curve 908, which depicts ΔC for an incident angle α2, including the optical system 300 with the comparative optical film. Graph 900 also includes curve 910, which depicts ΔC for an optical system 300 without any optical films for an incident angle α2. .

[0112] refer to Figure 8 and Figure 9 In some embodiments, for substantially collimated light 32 incident from light source D65 33 onto optical film 40, and for a first incident angle less than about 10 degrees (i.e., incident angle a2 < 10 degrees) and a second incident angle of about 89 degrees (i.e., incident angle a2 = 89 degrees), optical film 40 (e.g., optical films 40a, 40b, 40c) reflects the incident substantially collimated light 32, wherein for the corresponding first and second incident angles, the reflected light 34 has a chromaticity parameter C1 in the CIE Lab color space. and C2 .

[0113] As can be clearly seen from curves 902, 904, and 906 for the corresponding optical films 40a, 40b, and 40c, C2 With C1 The difference between them is greater than or equal to -6.8, that is, C2 -C1 ≥-6.8. In some implementations, C2 -C1 ≥-5.2. In some implementations, C2 -C1 ≥-4.6. In some implementations, C2 -C1 ≥-4.2. In some implementations, C2 -C1 ≥-6.5, C2 -C1 ≥-6.0, C2 -C1 ≥-5.5, C2 -C1 ≥-5.0, C2 -C1 ≥-4.5, C2 -C1 ≥-4.0, or C2 -C1 ≥-3.5. On the other hand, as is evident from curve 908 for the comparative optical film, C2 With C1 The difference between them is less than -6.8.

[0114] In some implementations, the first angle of incidence is less than about 8 degrees, less than about 6 degrees, less than about 4 degrees, less than about 2 degrees, or less than about 1 degree.

[0115] In some embodiments, for substantially collimated light 32 incident on optical film 40 from light source D65 33, and for a first incident angle less than about 10 degrees (i.e., incident angle a2 < 10 degrees) and for each third incident angle within an incident angle range 53 extending from about 86 degrees to about 89 degrees (i.e., incident angle a2 ≥ 86 degrees), optical film 40 (e.g., optical films 40a, 40b, 40c) reflects the incident substantially collimated light 32, wherein for the corresponding first and third incident angles, the reflected light 34 has a chromaticity parameter C1 in the CIE Lab color space. and C3 .

[0116] As can be clearly seen from curves 902 and 906 for the corresponding optical films 40a and 40c, C3 With C1 The difference between them is greater than or equal to -4.6, that is, C3 -C1 ≥-4.6. In some implementations, C3 -C1 ≥-4.2. In some implementations, C3 -C1 ≥-4.2. In some implementations, C3 -C1 ≥-4.4, C3 -C1 ≥-4.5, C3 -C1 ≥-4.2, C3 -C1 ≥-4.0, C3 -C1 ≥-3.7, or C3 -C1 ≥-3.5. On the other hand, as is evident from curve 908 for the comparative optical film, C3 With C1 The difference between them is less than -4.6.

[0117] Figures 10A-10C A depiction of one embodiment according to this disclosure is shown for different incident angles (i.e., Figure 8 (The different values ​​of the incident angle α2 shown), including the optical system 300 of the optical film 40. With B The curve showing the changes between them is 1000. Figure 10D This is an enlarged view of a portion of graph 1000. Figure 10E This is an enlarged view of another part of graph 1000. Figure 10F for Figure 10E A magnified view of a portion of graph 1000 shown. Expressed on the horizontal axis. B Expressed on the vertical axis.

[0118] Graph 1000 includes: curve 1002, which depicts the A of the optical system 300 including optical film 40a. and B Curve 1004 depicts the A-axis of the optical system 300, which includes optical film 40b. and B ; and curve 1006, which depicts the A of the optical system 300 including the optical film 40c. and B Graph 1000 also includes curve 1008, which depicts the A-axis of the optical system 300 including the comparative optical film. and B Graph 1000 also includes curve 1010, which depicts the A-axis of the optical system 300 without any optical films. and B .

[0119] refer to Figure 8 and Figure 10A As can be seen from curves 1002, 1004, and 1006 for the corresponding optical films 40a, 40b, and 40c, for substantially collimated light 32 incident from light source D65 33 onto optical film 40, optical film 40 reflects the incident substantially collimated light 32, wherein the reflected light 34 has a colorimetric parameter A in the CIE Lab color space. and B This causes the incident angle α2 of the substantially collimated incident light 32 to continuously change from approximately 0 degrees to approximately 89 degrees, A It remains within the first range 54a, extending from approximately -5 to approximately 4, and B It remains within a second range 54b extending from approximately -7 to approximately 4. The overlap between the first range 54a and the second range 54b is... Figure 10A The area shown in the middle is the shaded area.

[0120] Conversely, as clearly seen from curve 1008, the A of the optical film can be compared. It does not remain within the first range 54a. In other words, a portion of curve 1008 lies within... Figure 10A Outside the shaded area shown.

[0121] refer to Figure 8 and Figure 10B As can be seen from curves 1002 and 1006 for the corresponding optical films 40a and 40c, in some embodiments, as the incident angle α2 of the substantially collimated incident light 32 continuously varies from about 0 degrees to about 89 degrees, A It remains within the first range 55a extending from about -2 to about 4, and B It remains within a second range 55b extending from approximately -7 to approximately 1. The overlap between the first range 55a and the second range 55b is... Figure 10B The area shown is shaded.

[0122] Conversely, as clearly seen from curve 1008, the A of the optical film can be compared. It does not remain within the first range of 55a. In other words, a portion of curve 1008 lies within... Figure 10B Outside the shaded area shown.

[0123] refer to Figure 8 and Figure 10C As is evident from curve 1006 for optical film 40c, in some embodiments, as the incident angle α2 of the substantially collimated incident light 32 continuously varies from about 0 degrees to about 89 degrees, A It remains within the first range 56a extending from about -2 to about 4, and B It remains within a second range 56b extending from approximately -5 to approximately 1. The overlap between the first range 56a and the second range 56b is... Figure 10C The area shown in the middle is the shaded area.

[0124] Conversely, as clearly seen from curve 1008, the A of the optical film can be compared. and B It does not remain within the corresponding first range 56a and second range 56b. In other words, a portion of curve 1008 lies within... Figure 10C Outside the shaded area shown.

[0125] refer to Figure 8 and Figures 10D-10F As can be seen from curves 1002, 1004, and 1006 for the corresponding optical films 40a, 40b, and 40c, in some embodiments, for a substantially collimated light 32 incident at an angle of incidence of approximately 89 degrees (i.e., angle of incidence a2 = 89 degrees), A Within the first range 57a extending from about -0.5 to about 0.3, and B Within a second range 57b extending from about -1 to about 1. In some embodiments, the first range 57a extends from about 0.25, about 0.2, about 0.15, or about 0.1. Conversely, as is evident from curve 1008, compare the A of the optical film. It is approximately 0.42.

[0126] refer to Figure 9 and Figures 10A-10F Optical film 40 ( Figure 1 The color performance of the optical film (as shown) is superior to that of the comparative optical film. Furthermore, the optical film 40 can reduce or prevent visible color artifacts.

[0127] Unless otherwise stated, all figures used in the specification and claims to indicate feature dimensions, quantities, and physical properties should be understood to be modified by the term "about". Therefore, unless stated to the contrary, the numerical parameters listed in the foregoing specification and appended claims are approximations and can vary according to the desired properties sought by those skilled in the art using the teachings disclosed herein.

[0128] While specific embodiments have been illustrated and described herein, those skilled in the art will recognize that various alternative and / or equivalent embodiments may be used in place of the illustrated and described embodiments without departing from the scope of this disclosure. This application is intended to cover any modifications or variations of the specific embodiments discussed herein. Therefore, this disclosure is intended to be limited only by the claims and their equivalents.

Claims

1. An optical system, the optical system comprising: A display configured for outdoor use and exposure to sunlight, while simultaneously forming an image for a viewer to see; as well as An optical film disposed on the display, between the viewer and the display, and comprising at least 10 polymer microlayers, each polymer microlayer having an average thickness of less than about 500 nm, such that for substantially collimated incident light, in a red wavelength range extending from about 590 nm to about 670 nm, in a visible wavelength range extending from about 420 nm to about 680 nm, in an infrared wavelength range extending from about 850 nm to about 1600 nm, and for at least one of mutually orthogonal in-plane first polarization state and in-plane second polarization state: For an incident angle of less than about 10 degrees, the plurality of polymer microlayers have an average optical transmittance of more than about 60% in the visible wavelength range and an average optical transmittance of less than about 70% in the infrared wavelength range. as well as For an incident angle of at least about 70 degrees, the plurality of polymer microlayers have an average optical transmittance of more than about 50% in the red wavelength range.

2. The optical system of claim 1, wherein for substantially collimated light incident on the optical film from the light source D65, and for a first incident angle of less than about 10 degrees and a second incident angle of about 89 degrees, the optical film reflects the incident substantially collimated light, wherein for the corresponding first and second incident angles, the reflected light has a chromaticity parameter C1 in the CIE Lab color space. and C2 And C2 -C1 ≥-6.

8.

3. The optical system of claim 1, wherein for substantially collimated light incident on the optical film from the light source D65, and for each third angle of incidence within a range of about 10 degrees and extending from about 86 degrees to about 89 degrees, the optical film reflects the incident substantially collimated light, wherein for the corresponding first and second angles of incidence, the reflected light has a chromaticity parameter C1 in the CIE Lab color space. and C3 And C3 -C1 ≥-4.

6.

4. The optical system of claim 1, wherein the plurality of polymer microlayers comprises at least 10 first optical repeating units disposed on at least one spacer layer and separated from at least 10 second optical repeating units by the at least one spacer layer, each of the first optical repeating units having at least microlayers A1 and B1 having different compositions, each of the second optical repeating units having at least microlayers A2, B2, and C2 having different compositions, at least one of the microlayers A1 and B1 having a different composition from at least one of the microlayers A2, B2, and C2, each of the microlayers in the first and second optical repeating units having an average thickness of less than about 500 nm, and each of the at least one spacer layer having an average thickness of greater than about 500 nm.

5. The optical system of claim 4, wherein the first microlayer of microlayers A2, B2, and C2 comprises polyethylene terephthalate (PET), the second microlayer of microlayers A2, B2, and C2 comprises a copolymer of polymethyl methacrylate (CoPMMA), a copolymer of an aliphatic-aromatic polyester having a refractive index Ri for the visible wavelength range, or a material having the refractive index Ri for the visible wavelength range and optical transparency Ot, and the third microlayer of microlayers A2, B2, and C2 comprises ethylene glycol-modified polyethylene terephthalate (PETg) or a material having a refractive index Ric for the visible wavelength range and optical transparency Ot, where Ri < 1.52, Ric < 1.6, and Ot ≥ 80%.

6. The optical system of claim 5, wherein each optical repeating unit comprises one microlayer in microlayer A2, two microlayers in microlayer B2, and one microlayer in microlayer C2 arranged in an A2B2C2B2 configuration.

7. An optical film configured for outdoor use and exposure to sunlight, the optical film comprising at least 50 polymer microlayers, each of the polymer microlayers having an average thickness of less than about 500 nm, such that: For substantially collimated, substantially perpendicular incident light, and for each of two mutually orthogonal in-plane first and in-plane second polarization states, the plurality of polymer microlayers have an average optical transmittance greater than about 60% in the visible wavelength range extending from about 420 nm to about 680 nm, and an average optical transmittance less than about 70% in the infrared wavelength range extending from about 850 nm to about 1600 nm; and For substantially collimated light incident from light source D65 onto the optical film, the optical film reflects the incident substantially collimated light, wherein the reflected light has a colorimetric parameter A in the CIE Lab color space. and B This causes A to continuously change from approximately 0 degrees to approximately 89 degrees as the incident angle of the substantially collimated light changes. It remains within a first range extending from approximately -5 to approximately 4, and B It remains within the second range, extending from approximately -7 to approximately 4.

8. The optical film according to claim 7, wherein as the incident angle of the substantially collimated light continuously varies from about 0 degrees to about 89 degrees, A It remains within a first range extending from approximately -2 to approximately 4, and B It remains within the second range, extending from approximately -7 to approximately 1.

9. The optical film according to claim 7, wherein as the incident angle of the substantially collimated light continuously varies from about 0 degrees to about 89 degrees, A It remains within a first range extending from approximately -2 to approximately 4, and B It remains within the second range, extending from approximately -5 to approximately 1.

10. The optical film according to claim 7, wherein for the incident angle of the substantially collimated light incident at approximately 89 degrees, A Within the first range extending from approximately -0.5 to approximately 0.3, and B In the second range, extending from about -1 to about 1.

Images