Light control film and display system including same

Abstract

A light control film includes first and second portions extending along a width direction of the light control film and having respective first and second lengths along a length direction of the light control film orthogonal to the width direction, where the first portion includes alternating first light absorbing and first light transmissive regions arranged along the length direction at a first average pitch and disposed between, and substantially perpendicular to, opposing major surfaces of the light control film. The second portion is devoid of any light absorbing regions along the second length. Each first light absorbing region has a height along a thickness direction of the light control film where the height absorbing regions varies along the first length, such that a viewing angle range of the first portion varies along the first length. The second length is greater than 2 times the first average pitch.

Description

[0001] LIGHT CONTROL FILM AND DISPLAY SYSTEM INCLUDING SAME

[0002] TECHNICAL FIELD

[0003] The present description relates generally to light control films and to display systems including light control films.

[0004] BACKGROUND

[0005] A light control film can control transmission versus viewing angle of light transmitted through the film.

[0006] A vehicle can include a display for providing information to an occupant of the vehicle.

[0007] SUMMARY

[0008] In some aspects, the present description provides a light control film including alternating light absorbing and light transmissive regions arranged along a length direction of the light control film where a height of the light absorbing regions varies along at least a portion of the length.

[0009] In some aspects, the present description provides a light control film including first and second portions extending along a width direction of the light control film and having respective first and second lengths along a length direction of the light control film orthogonal to the width direction, where the first portion includes alternating first light absorbing and first light transmissive regions arranged along the length direction at a first average pitch and disposed between, and substantially perpendicular to, opposing major first and second surfaces of the light control film, and the second portion is devoid of any light absorbing regions along the second length. Each first light absorbing region has a height along a thickness direction of the light control film orthogonal to each of the length and width directions. The height of the first light absorbing regions varies along the first length, such that a viewing angle range of the first portion varies along the first length. The second length can be greater than 2 times the first average pitch.

[0010] In some aspects, the present description provides a display including a light control film of the present description. In some aspects, the present description provides a vehicle including the display.

[0011] These and other aspects will be apparent from the following detailed description. In no event, however, should this brief summary be construed to limit the claimable subject matter.

[0012] BRIEF DESCRIPTION OF THE DRAWINGS

[0013] FIGS. 1A-1B are schematic cross-sectional views of a light control film, according to some embodiments.

[0014] FIG. 2A is a schematic cross-sectional view of a display system, according to some embodiments. FIG. 2B is a schematic top plan view of an automobile including the display system of FIG. 2A, according to some embodiments.

[0015] FIG. 3A is a schematic cross-sectional view of another display system, according to some embodiments.

[0016] FIG. 3B is a schematic top plan view of an automobile including the display system of FIG. 3 A, according to some embodiments.

[0017] FIGS. 4-6 are schematic cross-sectional views of various display systems, according to some embodiments.

[0018] FIG. 7 is a schematic cross-sectional view a microstructured portion of a light control fdm, according to some embodiments.

[0019] FIGS. 8-9 are schematic top plan views of light control films, according to some embodiments.

[0020] FIG. 10 is a schematic illustration of a process for making a light control film, according to some embodiments.

[0021] FIG. 11 shows plots of transmission through a light control film versus polar angle, according to some embodiments.

[0022] FIG. 12 shows plots of normalized luminance through a light control film versus polar angle, according to some embodiments.

[0023] DETAILED DESCRIPTION

[0024] In the following description, reference is made to the accompanying drawings that form a part hereof and in which various embodiments are shown by way of illustration. The drawings are not necessarily to scale. It is to be understood that other embodiments are contemplated and may be made without departing from the scope or spirit of the present description. The following detailed description, therefore, is not to be taken in a limiting sense.

[0025] Automotive cockpits may utilize display screens in multiple locations for various applications. Each location / application can have its own desired display output distribution. Digital clusters can be used in front of the driver to display suitable driver information. The display output for this display may be desired to be narrow in the vertical direction to reduce reflected images from the windshield. It may also be desired for the display output to be narrow in the horizontal direction to mitigate reflected image in the side window. Center Information Displays can be used to display information to the passenger and driver and so the output may be desired to be broad in the horizontal direction while still being narrow in the vertical direction for windshield reflection management. In some cases, passenger displays may be desired to have a narrow output in the horizontal to limit visibility to the driver. In other cases, passenger displays may be desired to be viewable by the driver. The vertical view angle for the passenger displays may be desired to be narrow to mitigate windshield reflections. The emerging trend is to combine all three of these displays into one single display which spans from pillar to pillar across the dashboard of the vehicle. In this case, it may be desired for the display to have different display output distributions at different locations of the screen, and it may be desired that the transition in view angle across the screen appear seamless to the viewers.

[0026] According to some embodiments of the present description, a light control fdm is provided that, when incorporated into the display, results in at least some of these desired properties of the display output. A light control fdm can be described as a fdm that controls transmission versus viewing angle of light transmitted through the fdm. The light control fdms of the present description can include alternating light transmissive and light absorbing regions where the light absorbing regions have a height that varies over at least some portion of the light control fdm. It has been found that this variation in the height can be used to vary a range of viewing angles of light transmitted through the light control fdm. In some embodiments, the light control fdm further includes at least one microstructured portion that includes microstructures (e.g., prisms or Fresnel elements) where microstructures are structures having at least two orthogonal dimensions, such as a width and a height, less than 1 mm and greater than 100 nm. The microstructured portion(s) can be used to further adjust the variation on the viewing angle range.

[0027] Light control fdms are generally known in the art and are described in U.S. Pat. Nos. 8,012,567 (Gaides et al.); 8,213,082 (Gaides et al.); 9,791,709 (Ouderkirk et al.); and 11,550,183 (Schmidt et al.), and in U.S. Pat. Appl. Pub. Nos. 2022 / 0019007 (Schmidt et al.); 2020 / 0341173 (Schmidt et al.); 2020 / 0400865 (Schmidt et al.); and 2023 / 0028958 (Liu et al.), and in International Pat. Appl. Pub. No. WO 2021 / 090129 (Liu et al.), for example.

[0028] FIGS. 1A-1B are schematic cross-sectional views of a light control fdm 100, according to some embodiments. The light control fdm 100 includes first and second portions 101 and 102 where the first portion 101 has a first length LI along a length direction (x-direction) and includes alternating light absorbing and light transmissive regions 120 and 122 and the second portion has a second length L2 along the length direction and is devoid of any light absorbing region. The light absorbing regions of the first portion 101 have a height h along a thickness direction (z -direction) of the light control fdm that varies along the first length 101 such that a viewing angle range (e.g., AIL to AIR or A2L to A2R as schematically illustrated in FIG. IB) of the first portion varies along the first length 101. The viewing angle range can be determined from the height and spacing of the light absorbing regions (see, e.g., FIG. IB). The ellipsis in FIG. 1A schematically indicates that the sub-portion of the first portion can include more light absorbing regions 120 than schematically illustrated in FIG. IB that have a height varying between the heights of light absorbing regions 120a and 120b. The first and second portions 101 and 102 are arranged along the length direction (x-direction) and extend along a width direction (y-direction) orthogonal to the length direction. The second length L2 is typically at least two times an average pitch Pl of the light absorbing regions 120 and may be substantially larger than 2 Pl depending on the application. For use in automotive displays, L2 may be larger than LI. In some embodiments, the average pitch Pl is in a range of about 5 to 200 micrometers, or about 10 to 100 micrometers, for example. In some embodiments, each of LI and L2 is at least 1, 5, or 10 cm, for example. In some embodiments, a total length of the light control film along the length direction is no more than 10, 5, 4, 3, or 2.5 m, for example. The height of the light absorbing regions 120 (and / or 120' - see, e.g., FIGS. 2A and 3A) may each be less than about 500, 400, or 300 micrometers. In some embodiments, at least some of the light absorbing regions have a height of greater than about 10, 20, or 30 micrometers.

[0029] FIG. 2A is a schematic cross-sectional view of a display system 1001 including a light control fdm 200, according to some embodiments. The light control fdm 200 includes a third portion 103 having a third length L3 along the length direction where the second portion 102 is disposed between the first and third portions 101 and 103. The light control film 200 include first and second microstructured portions 150a and 150b disposed at least partially along the respective first and third portions 101 and 103 of the light control film. The display system 1001 includes a display 550 including first, second, and third display portions configured to form and emit respective first, second, and third images 551, 552, and 553. FIG. 2B is a schematic top plan view of a vehicle 1101 including the display system 1001. FIG. 3 A is a schematic cross-sectional view of a display system 1002 including a light control film 300, according to some embodiments. Light control film 300 includes a first microstructured portion 150a and a second microstructured portion 150c, 150d disposed at least partially along the respective first and third portions 101 and 103 of the light control film. The second microstructured portion 150b of light control film 200 may be configured to direct portions of transmitted light to each of first and second viewers 70 Iv and 702v at respective first and second locations 701 and 702, while the second microstructured portion 150c, 150d of light control film 300 may be configured to direction transmitted light primarily to the second viewer 702v. The first and second portions 150c and 150d of the second microstructured portions may define a linear Fresnel lens, for example. FIG. 3B is a schematic top plan view of a vehicle 1102 including the display system 1002. The vehicle 1101, 1102 has a windshield 560, a driver door 561 and a passenger door 562. The display 550 can be coextensive with greater than 50 (or 60, 70, 80, 90)% of a length Lw of the windshield 560 of the vehicle along a direction (x-direction) between opposing driver and passenger sides (sides of the respective driver and passenger doors 561 and 562) of the vehicle. The vehicle can be any vehicle (e.g., car, bus, truck, train, boat, plane) that includes a display (e.g., for displaying information to at least one occupant of the vehicle).

[0030] The driver door 561 and the passenger door 562 are schematically illustrated as being on the left and right sides, respectively, of the vehicle. However, it will be understood that the vehicle may alternatively be arranged with the driver door 561 and the passenger door 562 on the right and left sides, respectively, of the vehicle. In other words, the vehicle can be a left-hand drive vehicle or a right-hand drive vehicle. In either case, the first portion of the light control film may be disposed closer to the driver side than the passenger side, the third portion of the light control film may be disposed closer to the passenger side than the driver side, and the second portion of the light control film may be disposed between the first and third portions, according to some embodiments.

[0031] The microstructured portion(s) may be included to direct light to first and second viewers 70 Iv and 702v (e.g., a driver and a passenger) at respective first and second locations 701 and 702. FIGS. 2B and 3B shows schematic conoscope plots 711 schematically illustrating luminance distributions (e.g., schematically indicated by inner elliptical contour within the outer circle) for light emitted at various locations across the display (schematically indicated by position of the outer circle), where the emitted light at each of the various locations has a same emitted luminance. In FIG. 2B, light from each display portion 501, 502, and 503 is directed to each of the first and second locations 701 and 702. In FIG. 3B, light from each display portions 501 and 502 is directed to each of the first and second locations 701 and 702, and light from display portion 503 is directed to the second location 702 but substantially not to the first location 701.

[0032] In some embodiments, the light control film includes alternating light transmissive and light absorbing regions disposed only over one of the display portions. In other embodiments, the light control film includes alternating light transmissive and light absorbing regions disposed over at least two of the display portions. In some embodiments, the light control film covers one, two, three of all of the display portions.

[0033] FIGS. 4-6 are schematic cross-sectional views of display systems 1003-1005, respectively, according to some embodiments. Display system 1003 includes a light control film 400 having first and second portions 101 and 102 where first portion 101 is disposed along display portion 503 and second portion 102 is disposed along each of display portions 501 and 502. Display system 1004 includes a light control film 500 having first and second portions 101 and 102 where first portion 101 is disposed along display portion 501 and second portion 102 is disposed along display portion 502. In some embodiments, no portion of the light control film 500 is disposed over the display portion 503. Display system 1005 includes a light control film 600 having first and second portions 101 and 102 where first portion 101 is disposed along display portion 503 and second portion 102 is disposed along display portion 502. In some embodiments, no portion of the light control film 600 is disposed over the display portion 501.

[0034] In some embodiments, a light control film 100, 200, 300, 400, 500, 600, 700, 800, 900 (see, e.g., FIGS. 1A-10) includes first and second portions 101 and 102 (or 103 and 102) extending (e.g., substantially uniformly) along a width direction (y-direction) of the light control film and having respective first and second lengths LI and L2 along a length direction (x-direction) of the light control film orthogonal to the width direction. The first and second portions can be arranged along the length direction and may be (e.g., immediately) adjacent to one another and substantially coextensive with one another along the width direction (e.g., at least 60, 70, 80, 90, 95 or 98 percent of a width along the width direction of each portion can be coextensive with at least 60, 70, 80, 90, 95 or 98 percent of a width along the width direction of each other portion). The first portion 101 (or 103) includes alternating first light absorbing and first light transmissive regions 120 and 122 (or 120' and 122') arranged along the length direction at a first average pitch Pl and disposed between, and substantially perpendicular (e.g., within 20, 15, 10, 5, or 3 degrees of perpendicular) to, opposing major first and second surfaces 110 and 112 of the light control film. A region will be considered to be disposed between the major surfaces when the volume of the region is between the major surfaces even when one or both major surfaces comprise an end surface of the region. For example, in some embodiments, one of the major surfaces 110 and 112 comprises ends of the light absorbing and light transmissive regions.

[0035] Each first light absorbing region has a height h along a thickness direction (z -direction) of the light control film orthogonal to each of the length and width directions. In some embodiments, the height h of the first light absorbing regions varies along the first length LI, such that a viewing angle range (e.g., AIL to AIR or A2L to A2R) of the first portion 101 varies along the first length, and the second portion 102 is devoid of any light absorbing regions along the second length L2. In some embodiments, the second length L2 is greater than 2, 3, 4, 5, 6, 8, or 10 times the first average pitch Pl. In some embodiments, the second length L2 is greaterthan 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.6, 0.8, 1, 1.2, 1.5, 2, 3, 4, 5, or 6 times the first length LI. In some embodiments, the second length L2 is no more than 15, 12, or 10 times the first length LI. In some embodiments, the second length L2 is greaterthan 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, or 0.5 times a total length of the light control film along the length direction. The average pitch is the average (mean) of the pitch and may be determined as a distance between corresponding edges of the farthest apart light absorbing regions in the first portion divided by the number of light absorbing regions along that distance.

[0036] In some embodiments, each first light absorbing region 120 extends along the thickness direction (z-direction) of the light control film between first and second ends 221 and 222 of the light absorbing region 120, where the first end 221 is disposed between the major first surface 110 of the light control film and the second end 222. In some embodiments, the second ends 222 of the light absorbing regions 120 is a substantially same (e.g., same within 10, 5, 4, 3, or 2%) distance dl from the second major surface 112. In some embodiments, the substantially same distance dl is substantially zero (see, e.g., FIG. 10). In some embodiments, the substantially same distance dl is less than 10, 8, 6, 5, 4, 3, 2 or 1 percent of an average height ha of the first light absorbing regions 120. In some embodiments, the average height ha is in a range of about 5 to 500 micrometers, or about 10 to 400 micrometers, or about 15 to 300 micrometers, or about 20 to 250 micrometers, for example. In some embodiments, the maximum height of the first light absorbing regions is less than about 500 or 400 micrometers.

[0037] In some embodiments, the height of at least one (e.g., 120a - see, e.g., FIGS. 2A and 3A) of the first light absorbing regions 120 of the first portion 101 closer to the second portion 102 is less than the height of at least one other (e.g., 120b - see, e.g., FIGS. 2A and 3A) of the first light absorbing regions 120 of the first portion 101 farther from the second portion 102.

[0038] In some embodiments, the first light absorbing regions 120 include at least three or at least 4, 5, 6, 7, 8, 9, or 10 sequentially arranged light absorbing regions (e.g., 120a to 120b) having a monotonically increasing height along a direction (+x direction) from the second portion 102 to the first portion 101. In some embodiments, a first sub-portion of the first portion has light absorbing regions having a monotonically increasing height along a direction (+x direction) from the second portion 102 to the first portion 101 and a second sub-portion of the first portion has light absorbing regions having a substantially same height (e.g., same to within 5, 4, 3, or 2%), where the first sub-portion has a length along the length direction of about 5 to 50 percent of the length of the first portion 101 and the second sub-portion has a length along the length direction of about 50 to 95 percent of the length of the first portion 101.

[0039] FIG. 7 is a schematic cross-sectional view a microstructured portion 150 of a light control film, according to some embodiments. Microstructured portion 150 can correspond to any of microstructured portions 150a-150d. The microstructured portion 150 includes a plurality of microstructures 151 where each microstructure includes an optical facet 152 and a sidewall 153 meeting the optical facet 152 at a ridge 154 of the microstructure 151. The optical facet 152 and the sidewall 153 defines an oblique angle Al therebetween. In some embodiments, an optically absorptive layer 156 is disposed on at least one of the sidewalls 153. The optically absorptive layer 156 can have a height Hl along the thickness direction (z-direction) and a thickness t. In some embodiments, the optically absorptive layer 156 is coextensive with the sidewall 153 such that Hl is a height from a bottom 159 of the sidewall 153 to the ridge 154 of the microstructure 151. In some embodiments, for at least one of the microstructures 151, Hl / t is greater than 10, 12 or 15. In some embodiments, for each microstructure in at least a majority of the microstructures, Hl is in a range of about 1 to 100 micrometers, or about 2 to 50 micrometers. In some embodiments, for each microstructure in at least a majority of the microstructures, t is in a range of about 0.1 to 1 micrometers.

[0040] A majority is greater than 50 percent. A majority of the microstructures can be at least 51, 55, 60, 70, 80, 90, or 95 percent of the microstructures or can be all of the microstructures.

[0041] In some embodiments, the light control film further includes a first microstructured portion 150 (or any of 150a-150d) disposed adjacent the major first surface 110 opposite the major second surface 112 and at least partially coextensive in length and width with the first portion 101 of the light control film. The first microstructured portion 150 includes a plurality of first microstructures 151, where each first microstructure incudes an optical facet 152 and a sidewall 153 meeting the optical facet 152 at a ridge 154 of the first microstructure, and the optical facet and the sidewall defines an oblique angle Al therebetween. The oblique angle Al is typically an acute angle. In some embodiments, for each microstructure in at least a majority of the microstructures 151, the angle Al is at least about 30, 35, 40, 45, 50, 55, or 60 degrees. In some such embodiments, or in another embodiments, for each microstructure in a least a majority of the microstructures 151, the angle Al is no more than about 89, 88, 87, 85, 80, or 75 degrees.

[0042] In some embodiments, the light control film (e.g., light control film 300 schematically illustrated in FIG. 4) further includes a second microstructured portion (e.g., 150a) disposed adjacent the major first surface 110 opposite the major second surface 112 and at least partially coextensive in length and width with the second portion 102, but not the first portion 101, of the light control film. The second microstructured portion can include a plurality of second microstructures 151, where each second microstructure includes an optical facet 152 and a sidewall 153 meeting the optical facet at a ridge 154 of the second microstructure, and where the optical facet 152 and the sidewall 153 of the second microstructure defines an oblique angle (Al) therebetween.

[0043] In some embodiments, the oblique angle Al defined between the optical facet 152 and the sidewall 153 of at least one of the microstructures of the first microstructured portion closer to the second portion 102 of the light control film is greater than the oblique angle Al defined between the optical facet

[0044] 152 and the sidewall 153 of at least one other of the microstructures of the first microstructured portion farther from the second portion 102 of the light control film. In some such embodiments, or in other embodiments, the oblique angle Al defined between the optical facet 152 and the sidewall 153 of at least one of the microstructures of the second microstructured portion closer to the first portion 101 of the light control film is greater than the oblique angle Al defined between the optical facet 152 and the sidewall

[0045] 153 of at least one other of the microstructures of the second microstructured portion farther from the first portion 101 of the light control film

[0046] In some embodiments, the plurality of first microstructures defines a linear Fresnel lens. For example, microstructures 150c and 150d (in combination) as schematically illustrated in FIGS. 3 A, 4, 6 can define a linear Fresnel lens which can be in the first portion 101 of the light control film (see, e.g., FIGS. 4 and 6) or the third portion 103 (see, e.g., FIG. 3A).

[0047] In some embodiments, the optical facets 152 of the first microstructures (or the microstructures of the first microstructured portion, e.g., 150a in FIGS. 2A and 3 A) are inclined towards the second portion 102 of the light control film, such that the first microstructured portion shifts the viewing angle range of the first portion 101 of the light control film towards the second portion 102 of the light control film.

[0048] In some embodiments, an optically absorptive layer 156 is disposed on and substantially covers (e.g., covers greater than 60, 70, 80, or 90% of a total area of) the sidewall 153 of each first microstructure in at least a majority of the first microstructures. In some embodiments, the optically absorptive layer 156 comprises carbon black. In some embodiments, for each first microstructure in at least the majority of the first microstructures, the optically absorptive layer 156 has an average thickness t, 100 nm < t < 1 micrometer. In some embodiments, the average thickness t is less than 500 nm. In some embodiments, for each microstructure in at least a sub-plurality of the first microstructures, the sidewall 153 of the microstructure has a height Hl from a bottom 159 of the sidewall 153 adjacent the major first surface 110 to the ridge 154 of the microstructure. The bottom 159 of the sidewall 153 is opposite the ridge 154. In some embodiments, Hl / t > 10, 12, 15, 18, or 20. In some embodiments, the height Hl is less than 1 mm. A sub-plurality of the microstructures is at least two of the microstructures and less than all of the microstructures. At least a sub-plurality of the microstructures may encompass all of the microstructures. A sub-plurality can include at least 10, 20, 30, 40, 50, or 60 percent of the microstructures, for example.

[0049] In some embodiments, the light control film (e.g., 200, 300, 700, 800, 900) further includes a third portion 103 extending along the width direction (y-direction) of the light control film and having a third length L3 along the length direction (x-direction) of the light control fdm, where the second portion 102 is disposed between the first and third portions 101 and 103. The first, second, and third portions can be arranged along the length direction and may be substantially coextensive with one another along the width direction. The first and second portions may be immediately adjacent to one another and the second and third portions may be immediately adjacent to one another. The third portion 103 includes alternating second light absorbing (120') and second light transmissive (122') regions disposed between, and substantially perpendicular to, the major first and second surfaces 110 and 112. In some embodiments, each second light absorbing region 120' has a height h along the thickness direction of the light control film, where the height h of the second light absorbing regions varies along the third length L3, such that a viewing angle range of the third portion varies along the third length (e.g., AIL to AIR or A2L to A2R as schematically illustrated in FIG. IB). In some embodiments, the first, second and third lengths LI, L2 and L3 span substantially an entire length (e.g., greater than about 60, 70, 80, 90, or 95% of the entire length) of the light control film along the length direction (e.g., the entire length can be L1+L2+L3).

[0050] In some embodiments, each second light absorbing region 120' extends along the thickness direction (z-direction) of the light control film between first and second ends of the light absorbing region 120', where the first end is disposed between the major first surface 110 of the light control film and the second end. In some embodiments, the second ends of the light absorbing regions 120' is a substantially same distance dl from the second major surface 112. In some embodiments, the substantially same distance dl is substantially zero (see, e.g., FIG. 10). In some embodiments, the substantially same distance dl is less than 10, 8, 6, 5, 4, 3, 2 or 1 percent of an average height hb of the second light absorbing regions 120'. In some embodiments, the distance dl for the first and second light absorbing regions are substantially the same (e.g., the same to within about 10, 5, 4, 3, or 2%). In some embodiments, each of the average heights ha and hb is in a range of about 5 to 500 micrometers, or about 10 to 400 micrometers, or about 15 to 300 micrometers, or about 20 to 250 micrometers.

[0051] In some embodiments, the height of at least one (e.g., 120a') of the second light absorbing regions 120' closer to the second portion 102 is less than the height of at least one (e.g., 120b') other of the second light absorbing regions 120' farther from the second portion 102.

[0052] In some embodiments, an average of the heights ha of the first light absorbing regions 120 is less than an average of the heights hb of the second light absorbing regions 120', such that a viewing angle range of the third portion 103 is narrower than a viewing angle range of the first portion 101. In some embodiments, an average of the heights ha of the first light absorbing regions 120 and an average of the heights hb of the second light absorbing regions 120' are about equal.

[0053] In some embodiments, the light control film includes first and second microstructured portions (e.g., 150a and 150b, or 150a and 150c, 150d) disposed adjacent to the major first surface 110 of the light control film opposite the major second surface 112 and being at least partially coextensive in length and width with the respective first and third portions 101 and 103 of the light control film. In some embodiments, each of the first and second microstructured portions includes a plurality of microstructures 151, where each microstructure includes an optical facet 152 and a sidewall 153 meeting the optical facet 152 at a ridge 154 of the microstructure 151. The optical facet 152 and the sidewall 153 can define an oblique angle Al therebetween.

[0054] In some embodiments, the oblique angle Al defined between the optical facet 152 and the sidewall 153 of at least one of the first microstructures (e.g., 151a) of the first microstructured portion closer to the second microstructured portion is greater than the oblique angle defined between the optical facet and the sidewall of at least one other of the first microstructures (e.g., 151b) of the first microstructured portion farther from the second microstructured portion. In some such embodiments, or in other embodiments, the oblique angle Al defined between the optical facet 152 and the sidewall 153 of at least one of the second microstructures (e.g., 151c) of the second microstructured portion closer to the first microstructured portion is greater than the oblique angle Al defined between the optical facet 152 and the sidewall 153 of at least one other of the second microstructures (e.g., 15 Id) of the second microstructured portion farther from the first microstructured portion.

[0055] In some embodiments, the optical facets of the first microstructures (or the microstructures of the first microstructured portion 150a) are inclined towards the second microstructured portion (see, e.g., FIGS. 2A, 3 A and 4) such that the first microstructured portion shifts the viewing angle range of the first portion of the light control film towards the second microstructured portion (see, e.g., plot 711 along portion 101 in FIGS. 2B and 3B). In some such embodiments, of in other embodiments, the optical facets of the second microstructures (or the microstructures of the second microstructured portion 150b) are inclined towards the first microstructured portion (see, e.g., FIG. 2A), such that the second microstructured portion shifts the viewing angle range of the third portion of the light control film towards the first microstructured portion (see, e.g., plot 711 along portion 103 in FIG. 2B).

[0056] In some embodiments, the third portion 103 of the light control film includes a first sub-portion (e.g., portion covered by 150c) and a second sub-portion (e.g., portion covered by 150d) adjacent to the first sub-portion (see, e.g., FIGS. 3A, 4, 6). In some embodiments, each of the optical facets of the microstructures of the second microstructured portion disposed along the first sub-portion (e.g., portion 150c of the second microstructured portion) are inclined towards a first direction (plus x direction) extending from the first microstructured portion towards the second microstructured portion and each of the optical facets of the microstructures of the second microstructured portion disposed along the second sub-portion (e.g., portion 150d of the second microstructured portion) are inclined towards a second direction (minus x direction) opposite to the first direction (see, e.g., FIGS. 3A, 4, 6), such that the second microstructured portion shifts the viewing angle range of the third portion of the light control along the first and second directions in the first and second sub-portions, respectively (see, e.g., plots 711 in portion 103 in FIG. 3B).

[0057] In some embodiments, the first (resp., second) microstructured portion is at least partially coextensive in length (x-direction) with the first (resp., third) portion of the light control film and is substantially coextensive in width (y-direction) with the first (resp., third) portion of the light control film.

[0058] Layers or elements can be described as substantially coextensive with each other in length and / or width if at least about 60% of the length and / or width of each layer or element is co-extensive with at least about 60% of the length and / or width of each other layer or element. In some embodiments, for layers or elements described as substantially coextensive with each other in length and / or width, at least about 80% or at least about 90% of each layer or element is co-extensive in length and / or width with at least about 80% or at least about 90% of the length and / or width of each other layer or element.

[0059] In some embodiments, the plurality of microstructures of the second microstructured portion defines a linear Fresnel lens (e.g., the combination of 150c and 150d can define a linear Fresnel lens).

[0060] In some embodiments, an optically absorptive layer 156 is disposed on and substantially covers the sidewall 153 of each microstructure in at least a majority of the microstructures of each of the first and second microstructured portions. In some embodiments, the optically absorptive layer 156 comprises carbon black. In some embodiments, for each microstructure in at least the majority of the microstructures of each of the first and second microstructured portions, the optically absorptive layer has an average thickness t, where 100 nm < t < 1 micrometer or t can be in a range described elsewhere herein. In some embodiments, for each microstructure in at least a sub-plurality of the first microstructures, the sidewall of the microstructure has a height Hl from a bottom 159 of the sidewall 153 adjacent the major first surface 110 to the ridge 154 of the microstructure, where Hl / t > 10 or Hl / t can be in another range described elsewhere herein.

[0061] In some embodiments, each of the light absorbing regions 120, 120' extends substantially linearly and substantially uniformly (e.g., nominally linearly and uniformly or linearly and uniformly up to variations small (e.g., less than 20, 10, or 5%) compared to the average pitch Pl) along the width direction. In some embodiments, each of the ridges 154 of each microstructured portion extend substantially linearly and substantially uniformly (e.g., nominally linearly and uniformly or linearly and uniformly up to variations small (e.g., less than 20, 10, or 5%) compared to an average width of the microstructures) along the same width direction (y-direction). In other embodiments, the ridges 154 may extend along a direction making an angle (bias angle) with the width direction. The bias angle can be the same or different for the first and second microstructured portions and can be non-zero for at least one of the first and second microstructured portions.

[0062] FIGS. 8-9 are schematic top plan views of light control films 700, 800, according to some embodiments. For each of the light control films 700 and 800, the light absorbing regions 120, 120' extend along a same width direction (y-direction). The ridges 154 of the first and second microstructured portions are arranged along a first direction (x1-direction or x" -direction) and extend along a second direction (y'-direction or y"-direction). An angle between the width direction (y-direction) and the second direction (y'-direction or y"-direction) is the bias angle Ba. For light control film 700, the second direction (y'-direction) of the first and second microstructured portions are the same or substantially the same (e.g., same to within about 5 degrees). For light control film 800, the second direction (y'-direction or y"-direction) of the first and second microstructured portions are different (e.g., different by greater than about 5 degrees). In some embodiments, Ba may be non-zero due to ordinary manufacturing variations. In some embodiments, Ba is deliberately non-zero. For example, the ridges 154 may be tilted relative to light absorbing regions 120 differently in different regions as schematically illustrated in FIG. 9 for increased visibility of display portion 501 at first location 701 and reduced visibility of display portion 503 at first location 701.

[0063] In some embodiments, the first microstructures 151 are arranged along a first direction (x’- direction) and extend substantially uniformly (e.g., nominally uniformly or uniform up to variations small (e.g., less than 20, 10, or 5%) compared to an average width of the microstructures along the first direction) along a second direction (y'-direction) orthogonal to the first direction, and the light absorbing regions 120 of the light control film extends along the width direction (y-direction) of the light control film. In some embodiments, the width direction (y-direction) makes an angle Ba with the second direction of less than about 30, 25, 20, 15, 10, 5, 4, 3, or 2 degrees.

[0064] In some embodiments, the microstructures of the first and second microstructured portions are arranged along a first direction (x’ -direction) and extend substantially uniformly along a second direction (y'-direction) orthogonal to the first direction, and the light absorbing regions of the light control film extend along the width direction (y-direction) of the light control film, where the width direction makes an angle Ba with the second direction of less than about 30, 25, 20, 15, 10, 5, 4, 3, or 2 degrees. In some embodiments, the second direction of the first and second microstructured portions are substantially same. In some embodiments, the second direction of the first and second microstructured portions are different (see, e.g., y" and y' in FIG. 9).

[0065] In some embodiments, a display system 1001, 1002, 1003, 1004, 1005 for use in a vehicle 1101, 1102 includes a display 550 including first (501 or 503) and second (502) display portions configured to form and emit respective first (551 and 552) and second (552) images; and a light control film of the present description disposed to receive the emitted first and second images, where the first and second display portions are at least partially coextensive in lengths and widths with the respective first and second portions of the light control film.

[0066] In some embodiments, a display system (e.g., 1001, 1002) for use in a vehicle (e.g., 1101, 1102) includes a display 550 including first (501 or 503) and second (502) display portions configured to form and emit respective first and second images; and a light control film (e.g., 200, 300) disposed to receive the emitted first and second images and transmit each of the first and second images to each of first and second viewers 70 Iv and 702v at respective first and second locations 701 and 702 spaced apart along the length direction (x-direction) of the light control film, where the first and second display portions are at least partially coextensive in lengths and widths with the respective first and second portions of the light control film. In some embodiments, the light control film includes at least a first microstructured portion as described further elsewhere herein. In some embodiments, the oblique angles of the first microstructures (e.g., 150a) vary along the length direction so that when the emitted first and second images have a same emitted luminance, the variation of the oblique angles reduces a variation in luminance (e.g., as schematically indicated by conoscope plots 711 in FIGS. 2B and 3B) between the transmitted first and second images at each of the first and second locations.

[0067] In some embodiments, the first and second portions of the light control film are at least partially coextensive in length (x-direction) with the respective first and second display portions and are substantially coextensive in width (y-direction) with the respective first and second display portions. In some embodiments, the first and second portions of the light control film are substantially coextensive in length and width with the respective first and second display portions.

[0068] In some embodiments, a display system (e.g., 1001, 1002) for use in a vehicle (e.g., 1101, 1102) includes a display 550 including first, second, and third display portions 501, 502, and 503 configured to form and emit respective first, second, and third images 551, 552, and 553; and a light control film of the present description disposed to receive the emitted first, second, and third images, where the first, second, and third display portions 501, 502, and 503 are at least partially coextensive in lengths and widths with the respective first, second, and third portions 101, 102, and 103 of the light control film. The vehicle can be any automobile that includes a display, for example.

[0069] In some embodiments, a display system (e.g., 1001, 1002) for use in a vehicle (e.g., 1101, 1102) including a display 550 including first, second, and third display portions 501, 502, and 503 configured to form and emit respective first, second, and third images 551, 552, and 553; and a light control film of the present description, which includes first and second microstructured portions, disposed to receive the emitted first, second, and third images 551, 552, and 553 and to transmit each of the first, second, and third images to each of first and second viewers 70 Iv and 702v at respective first and second locations 701 and 702 spaced apart along the length direction (x-direction), where the first, second, and third display portions 501, 502, and 503 are at least partially coextensive in lengths and widths with the respective first, second, and third portions 101, 102, and 103 of the light control film. In some embodiments, the light control film includes first and second microstructured portions as described further elsewhere herein. In some embodiments, the oblique angles Al of the microstructures of the first and second microstructured portions vary along the length direction (x-direction) so that when the emitted first, second, and third images have a same emitted luminance, the variation of the oblique angles reduces a variation in luminance between the transmitted first, second, and third images 551, 552, and 553 at each of the first and second locations 701 and 702.

[0070] In some embodiments, a display system (e.g., 1001, 1002) for use in a vehicle (e.g., 1101, 1102) including a display 550 including first, second, and third display portions 501, 502, and 503 configured to form and emit respective first, second, and third images 551, 552, and 553; and a light control film of the present description, which includes first and second microstructured portions, disposed to receive the emitted first, second, and third images 551, 552, and 553 and to transmit each of the first and second images 551 and 552 to each of first and second viewers 70 Iv and 702v at respective first and second locations 701 and 702 spaced apart along the length direction (x-direction) and to transmit the third image 553 to the second viewer 702v, where the first, second, and third display portions 501, 502, and 503 are at least partially coextensive in lengths and widths with the respective first, second, and third portions 101, 102, and 103. of the light control film. In some embodiments, the light control film includes first and second microstructured portions. In some embodiments, the oblique angles Al of the microstructures of the first and second microstructured portions vary along the length direction (x-direction) so that when the emitted first, second, and third images 551, 552, 553 have a same emitted luminance, the variation of the oblique angles Al reduces a variation in luminance between the transmitted first and second images at each of the first and second locations and reduces a variation in luminance between the transmitted first, second, and third images at the second location. In some embodiments, the plurality of second microstructures defines a linear Fresnel lens (e.g., 150c, 150d) configured so that the luminance of the third image 553 at the first location 701 is substantially lower (e.g., lower by at least 60, 70, 80, or 90 percent) than the luminance of the third image 553 at the second location 702 (see, e.g., plots 711 along portion 103 in FIG. 3B).

[0071] In some embodiments, the first, second, and third portions of the light control film are at least partially coextensive in length (x-direction) with the respective first, second, and third display portions and are substantially coextensive in width (y-direction) with the respective first, second, and third display portions. In some embodiments, the first, second, and third portions of the light control film are substantially coextensive in length and width with the respective first, second, and third display portions.

[0072] In some embodiments, a vehicle (e.g., 1101, 1102) includes the display system (e.g., 1001, 1002). In some embodiments, the display 550 is coextensive with greater than 50% (or greater than 60, 70, 80, 90 percent) of a length Lw of a windshield 560 of the vehicle along a direction (x-direction) between opposing driver and passenger sides (sides of driver and passenger doors 561 and 562) of the vehicle. The first display portion 501 and the first location 701 is disposed closer to the driver side than to the passenger side, and the third display portion 503 and the second location 702 is disposed closer to the passenger side than to the driver side.

[0073] In some embodiments, a vehicle (e.g., 1101, 1102) includes a display 550 coextensive with greater than 50% (or another range described elsewhere herein) of a length Lw of a windshield 560 of the vehicle along a direction (x-direction) between opposing driver and passenger sides (corresponding to driver and passenger doors 561 and 562) of the vehicle. The display can include first, second, and third display portions 501, 502, and 503 configured to form and emit respective first, second, and third images 551, 552, 553, where the first display portion 501 is disposed closer to the driver side than to the passenger side, third display 503 portion is disposed closer to the passenger side than to the driver side, and the second display portion 502 is disposed between the first and third display portions 501 and 503. The vehicle further includes a light control film of the present description disposed to receive the emitted first, second, and third images 551, 552, and 553, where the first, second, and third display portions 501, 502, and 503 are at least partially coextensive in lengths and widths with the respective first, second, and third portions 101, 102, and 103 of the light control film.

[0074] In some embodiments, the second portion 102 of the light control film is coextensive with greater than 10, 20, 30, 40, or 50% of the length Lw of the windshield 560. In some embodiments, each of the first and third portions 101 and 103 of the light control film is coextensive with greater than 3, 5, 10, 15, 20, 25, or 30% of the length Lw of the windshield 560. In some embodiments, the second portion 102 has a length along the length direction greater than that of each of the first and third portions 101 and 103. In some embodiments, the second portion 102 has a length along the length direction greater a combined length along the length direction of the first and third portions 101 and 103.

[0075] Light control films and methods of making light control films are generally known in the art and are described in U.S. Pat. Nos. 8,012,567 (Gaides et al.); 8,213,082 (Gaides et al.); 9,791,709 (Ouderkirk et al.); and 11,550,183 (Schmidt et al.), and in U.S. Pat. Appl. Pub. Nos. 2022 / 0019007 (Schmidt et al.); 2020 / 0341173 (Schmidt et al.); 2020 / 0400865 (Schmidt et al.); and 2023 / 0028958 (Liu et al.), and in International Pat. Appl. Pub. No. WO 2021 / 090129 (Liu et al.), for example. In some methods of making such light control film, a pattern is cut into a substrate to make a tool that can be used to make a structured film in a cast and cure process where a resin is cast against the structured surface of the tool and then cured (e.g., via applying actinic radiation) in contact with the structured surface of the tool to form the structured film. The structured film can be backfilled with light absorbing material (e.g., a resin filling spaces between structures) to form the light absorbing regions of the light control film as generally described in the above Gaides et al. references, for example, or a structured major surface of the light control film can be conformally coated (e.g., via layer by layer self-assembly) with light absorbing material, the light absorbing material removed (e.g., via reactive ion etching) from horizontal surfaces, and then remaining spaces between structures optionally backfilled with light transmissive material as generally described in the above Schmidt et al. references, for example. According to some embodiments of the present description, a light control film is made using a process similar to any of these processes except that the tool is modified to result in the variation of height of the light absorbing regions described elsewhere herein. The modification can include modifying the pattern cut into the tool substrate such that the resulting tool produces the height variation or can include cutting the conventional tool to so that the cut tool produces the desired height variation.

[0076] FIG. 10 is a schematic illustration of a process for making a light control film 900, according to some embodiments. A tool 810 having a structured tool surface 811 is provided (e.g., via cutting a tool substrate as described elsewhere herein). Resin 820 is cast against the tool surface 811 and cured (e.g., via applying ultraviolet radiation) in contact with the tool surface and a substrate 830. A rigid substrate 840 (e.g., a plate) may be used to hold the substrate 830 and resin 820 against the tool surface 811. After curing the resin 820, the structured film 850 is removed from the tool. Spaces 852 between structures 853 of the structured film can then be filled with light absorbing material 855 to provide the light control film 900. Alternatively, the structures 853 can be conformally coated with a light absorbing material which is subsequently removed from the horizontal surfaces, and then the resulting fdm can be optionally backfilled with light transmissive material, to provide a light control film.

[0077] Microstructured portions can be added to the light control film by, for example, casting and curing microstructures directly on a major surface of the light control film or by casting and curing the microstructures on a substrate which is then attached (e.g., via an optically clear adhesive) to a major surface of the light control film. Optically absorptive layer 156 can be added onto the sidewalls 153 of the microstructures 151 by conformally coating the microstructures 151 with a light absorbing material and then removing (e.g., via reactive ion etching) the light absorbing material from the facets 152. Useful cast and cure processes are described in U.S. Pat. Appl. Pub. No. 2006 / 0114569 (Capaldo et al.) and U.S. Pat. Nos. 5,175,030 (Uu et al.) and 5,183,597 (Uu), for example. Useful methods for applying an optically absorptive layer to the sidewalls and other useful methods of making microstructures are described in International Appl. Pub. No. 2021 / 090130 (Uiu et al.), for example.

[0078] Another exemplary method of making a light control fdm includes thermo-compressing a block of light transmissive and light absorbing layers and then repeatedly slicing or skiving perpendicularly to, or at a certain angle with respect to, the surface thereof to form sheets of light control fdm. This approach is generally described, for example, in International Appl. Pub. No. WO 2005 / 092544 (Shewa P & C Co., UTD.) and U.S. Pat. No. 2,053,173 (Astima). A portion of the resulting fdm may then be cut out from a major surface thereof to produce a thickness variation of the fdm and a corresponding height variation of the light absorbing regions, or the fdm may be skived from the block of layers along a curve to produce a variation in height of the light absorbing region. The cut or skived surface may optionally be backfdled with light transmissive material to result in a substantially planar major surface, if desired. A portion (or portions) of the light control fdm that is devoid of any light absorbing regions can be included by incorporating suitably thick light transmissive layer(s) in the block of layers.

[0079] EXAMPUES

[0080] EXAMPLE 1

[0081] A light control fdm as generally described in the Gaides et al. references provided elsewhere herein but having varying heights of light absorbing regions was made using the process schematically illustrated in FIG. 10. Transmission through the light control fdm as a function of viewing angle (polar angle in xz plane) was measured. FIG. 11 shows plots of transmission through the light control fdm in a portion (l_Louver 100%) where the light absorbing regions (louvers) had the full height, a transition portion (2_Transition) where the louvers had an average height of approximately 20% of the full height, and a portion (3_Louver 0%) without louvers. Results are show for light incident on major surface 112 closest to the louvers (#1, #2, #3) and for light incident on opposite major surface 110 (#4, #5, #6). EXAMPLE 2

[0082] A light control film as generally described in the Schmidt et al. references provided elsewhere herein but having varying heights of light absorbing regions was made as generally described in the Schmidt et al. references but using a tool 810 as schematically illustrated in FIG. 10. A microstructured portion 150c, 150d was formed via a cast and cure process, the resulting microstructures 151 were conformally coated via layer-by-layer (LbL) deposition with a light absorbing material which was then removed via reactive ion etching from the facets 152 as generally described in International Appl. Pub. No. 2021 / 090130 (Liu et al.). The microstructured portion was then attached to the major surface 110 of the light control film. The microstructure portion defined a linear Fresnel lens where the angles Al varied monotonically from about 88 degrees near the center of the Fresnel lens to about 63 degrees at the edges of the Fresnel lens. Transmission through the light control film as a function of viewing angle (polar angle in xz plane) for light incident on surface 112 was measured. FIG. 12 shows plots of normalized luminance transmitted through the light control film without the Fresnel lens and with the Fresnel lens for light along the center of the Fresnel lens and at positions of 3.5 and 4.5 mm from the center.

[0083] Terms such as “about” will be understood in the context in which they are used and described in the present description by one of ordinary skill in the art. If the use of “about” as applied to quantities expressing feature sizes, amounts, and physical properties is not otherwise clear to one of ordinary skill in the art in the context in which it is used and described in the present description, “about” will be understood to mean within 10 percent of the specified value. A quantity given as about a specified value can be precisely the specified value. For example, if it is not otherwise clear to one of ordinary skill in the art in the context in which it is used and described in the present description, a quantity having a value of about 1, means that the quantity has a value between 0.9 and 1. 1, and that the value could be 1.

[0084] Terms such as “substantially” will be understood in the context in which they are used and described in the present description by one of ordinary skill in the art. If the use of “substantially” with reference to a property or characteristic is not otherwise clear to one of ordinary skill in the art in the context in which it is used and described in the present description and when it would be clear to one of ordinary skill in the art what is meant by an opposite of that property or characteristic, the term “substantially” will be understood to mean that the property or characteristic is exhibited to a greater extent than the opposite of that property or characteristic is exhibited.

[0085] All references, patents, and patent applications referenced in the foregoing are hereby incorporated herein by reference in their entirety in a consistent manner. In the event of inconsistencies or contradictions between portions of the incorporated references and this application, the information in the preceding description shall control.

[0086] Descriptions for elements in figures should be understood to apply equally to corresponding elements in other figures, unless indicated otherwise. Although specific embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that a variety of alternate and / or equivalent implementations can be substituted for the specific embodiments shown and described without departing from the scope of the present disclosure. This application is intended to cover any adaptations, or variations, or combinations of the specific embodiments discussed herein. Therefore, it is intended that this disclosure be limited only by the claims and the equivalents thereof.

Claims

What is claimed is:

1. A light control film comprising: first and second portions extending along a width direction of the light control film and having respective first and second lengths along a length direction of the light control film orthogonal to the width direction, the first portion comprising alternating first light absorbing and first light transmissive regions arranged along the length direction at a first average pitch and disposed between, and substantially perpendicular to, opposing major first and second surfaces of the light control film, each first light absorbing region having a height along a thickness direction of the light control film orthogonal to each of the length and width directions, wherein the height of the first light absorbing regions varies along the first length, such that a viewing angle range of the first portion varies along the first length, wherein the second portion is devoid of any light absorbing regions along the second length, and wherein the second length is greater than 2 times the first average pitch.

2. The light control film of claim 1, wherein the second length is greater than 0.2 times a total length of the light control film along the length direction.

3. The light control film of claim 1 or 2, wherein each first light absorbing region extends along the thickness direction of the light control film between first and second ends of the light absorbing region, the first end disposed between the major first surface of the light control film and the second end, the second ends of the light absorbing regions being a substantially same distance from the second major surface.

4. The light control film of any one of claims 1 to 3, wherein the height of at least one of the first light absorbing regions of the first portion closer to the second portion is less than the height of at least one other of the first light absorbing regions of the first portion farther from the second portion.

5. The light control film of any one of claims 1 to 4, wherein the first light absorbing regions comprise at least three sequentially arranged light absorbing regions having a monotonically increasing height along a direction from the second portion to the first portion.

6. The light control film of any one of claims 1 to 5 further comprising a first microstructured portion disposed adjacent the major first surface opposite the major second surface and at least partially coextensive in length and width with the first portion of the light control film, the first micro structured portion comprising a plurality of first microstructures, each first microstructure comprising an optical facet and a side wall meeting the optical facet at a ridge of the first microstructure, the optical facet and the sidewall defining an oblique angle therebetween.

7. The light control film of claim 6. wherein the first microstructures are arranged along a first direction and extend substantially uniformly along a second direction orthogonal to the first direction, the light absorbing regions of the light control film extending along the width direction of the light control film, the width direction making an angle with the second direction of less than about 30 degrees.

8. The light control film of claim 6 or 7, wherein the oblique angle defined between the optical facet and the sidewall of at least one of the first microstructures of the first microstructured portion closer to the second portion of the light control film is greater than the oblique angle defined between the optical facet and the sidewall of at least one other of the first microstructures of the first microstructured portion farther from the second portion of the light control film.

9. The light control film of any one of claims 1 to 5, wherein the light control film further comprises a third portion extending along the length direction of the light control film and having a third length along the length direction of the light control film, the second portion disposed between the first and third portions, the third portion comprising alternating second light absorbing and second light transmissive regions disposed between, and substantially perpendicular to, the major first and second surfaces, each second light absorbing region having a height along the thickness direction of the light control film, wherein the height of the second light absorbing regions varies along the third length, such that a viewing angle range of the third portion varies along the third length.

10. The light control film of claim 9, wherein the height of at least one of the second light absorbing regions closer to the second portion is less than the height of at least one other of the second light absorbing regions farther from the second portion.

11. The light control film of claim 9 or 10, further comprising first and second microstructured portions disposed adjacent to the major first surface of the light control film opposite the major second surface and being at least partially coextensive in length and width with the respective first and third portions of the light control film, each of the first and second microstructured portions comprising a plurality of microstructures, each microstructure comprising an optical facet and a sidewall meeting the optical facet at a ridge of the microstructure, the optical facet and the sidewall defining an oblique angle therebetween.

12. The light control film of claim 11, wherein the oblique angle defined between the optical facet and the sidewall of at least one of the microstructures of the first microstructured portion closer to the second microstructured portion is greater than the oblique angle defined between the optical facet and the side wall of at least one other of the microstructures of the first microstructured portion farther from the second microstructured portion, and wherein the oblique angle defined between the optical facet and thesidewall of at least one of the microstructures of the second microstructured portion closer to the first microstructured portion is greater than the oblique angle defined between the optical facet and the side wall of at least one other of the microstructures of the second microstructured portion farther from the first microstructured portion.

13. The light control film of claim 11, wherein the optical facets of microstructures of the first microstructured portion are inclined towards the second microstructured portion, such that the first microstructured portion shifts the viewing angle range of the first portion of the light control film towards the second microstructured portion, and wherein the optical facets of the microstructures of the second microstructured portion are inclined towards the first microstructured portion, such that the second microstructured portion shifts the viewing angle range of the third portion of the light control film towards the first microstructured portion.

14. A display system for use in a vehicle, the display system comprising: a display comprising first, second, and third display portions configured to form and emit respective first, second, and third images; and the light control film of any one of claims 11 to 13 disposed to receive the emitted first, second, and third images and to transmit each of the first, second, and third images to each of first and second viewers at respective first and second locations spaced apart along the length direction, the first, second, and third display portions being at least partially coextensive in lengths and widths with the respective first, second, and third portions of the light control film, wherein the oblique angles of the microstructures of the first and second microstructured portions vary along the length direction so that when the emitted first, second, and third images have a same emitted luminance, the variation of the oblique angles reduces a variation in luminance between the transmitted first, second, and third images at each of the first and second locations.

15. A display system for use in a vehicle, the display system comprising: a display comprising first, second, and third display portions configured to form and emit respective first, second, and third images; and the light control film of any one of claims 11 to 13 disposed to receive the emitted first, second, and third images and to transmit each of the first and second images to each of first and second viewers at respective first and second locations spaced apart along the length direction and to transmit the third image to the second viewer, the first, second, and third display portions being at least partially coextensive in lengths and widths with the respective first, second, and third portions of the light control film, wherein the oblique angles of the microstructures of the first and second microstructured portions vary along the length direction so that when the emitted first, second, and third images have a sameemited luminance, the variation of the oblique angles reduces a variation in luminance between the transmited first and second images at each of the first and second locations and reduces a variation in luminance between the transmited first, second, and third images at the second location.

Images