Light control film, display system, and method of making optical construction

Abstract

A light control film (LCF) includes a light input surface and a light output surface opposite the light input surface. The LCF further includes alternating light transmissive regions and light absorbing regions disposed between the light input surface and the light output surface. The light absorbing regions extend along a same in-plane first direction and are arranged along an in-plane orthogonal second direction. Each of the light absorbing regions has opposite top and bottom surfaces and first and second sidewalls extending between the top and bottom surfaces. The first sidewall is inclined at a first inclination angle with respect to a normal from the bottom surface along the second direction. Further, the second sidewall is inclined at a second inclination angle with respect to the normal along the second direction. The second inclination angle is greater than the first inclination angle.

Description

PA103050W002LIGHT CONTROL FILM, DISPLAY SYSTEM, AND METHOD OF MAKING OPTICAL CONSTRUCTIONTechnical Field

[0001] The present disclosure relates to a light control film, a display system, and a method of making an optical construction.Background

[0002] Light control films (LCF) are configured to regulate transmission of light. LCFs typically include a light transmissive film having a plurality of light absorbing regions that include a lightabsorbing material. The LCFs can be placed proximate a surface, such as a display surface, an image surface, or any other surface including an image to be viewed. Typically, the LCFs provide a symmetric light output with a maximum optical transmission such as a peak brightness at a center or on-axis (i.e., near a central viewing angle) and falls off gradually at wider angles. The aforesaid LCFs can provide privacy (e.g., for laptops, ATM) or safety (e.g., for windshield light reflection mitigation in cars).

[0003] However, in certain applications such as in displays of a vehicle, the LCFs may be required to provide and regulate the maximum optical transmission at off-axis / away from the center. In such applications, control on the visibility of information appearing in the display towards occupants that are positioned away from the center, for example, to provide desired visual information to a driver or a passenger in the vehicle, or to avoid distraction of the driver, is desired.Summary

[0004] In a first aspect, the present disclosure provides a light control film (LCF). The LCF includes a light input surface and a light output surface opposite the light input surface. The LCF further includes alternating light transmissive regions and light absorbing regions disposed between the light input surface and the light output surface. The light absorbing regions extend along a same in-plane first direction and are arranged along an in-plane orthogonal second direction. Each of the light absorbing regions has opposite top and bottom surfaces and first and second sidewalls extending between the top and bottom surfaces. The first sidewall is inclined at a first inclination angle with respect to a normal from the bottom surface along the second direction. Further, the second sidewall is inclined at a second inclination angle with respect to the normal along the second direction. The second inclination angle is greater than the first inclination angle.

[0005] In a second aspect, the present disclosure provides a display system for use in a vehicle. The display system includes a display configured to form and emit an image light for viewing by an eye of one or more occupants of the vehicle. The display system further includes a light control film (LCF). The LCF includes a light input surface and a light output surface opposite the light inputsurface. The LCF further includes alternating light transmissive regions and light absorbing regions disposed between the light input surface and the light output surface. The light absorbing regions extend along a same in-plane first direction and are arranged along an in-plane orthogonal second direction, such that the light input surface faces the display and the light output surface faces the eye of one or more occupants of the vehicle. The eye of one or more occupants of the vehicle is disposed in a first incident plane extending along the second direction. The LCF is configured to receive the emitted image light and transmit the image light toward the one or more occupants. For a substantially collimated incident light propagating in the first incident plane extending along the second direction, the LCF transmits greater than or equal to about 50% of the incident light. For a substantially collimated incident light propagating in a second incident plane extending along the first direction, the LCF transmits less than or equal to about 30% of the incident light. The display system further includes a light diffuser disposed on the LCF opposite to the display. The light diffuser is less diffusive along the second direction than along the first direction.

[0006] In a third aspect, the present disclosure provides a method of making an optical construction. The method includes providing a first substrate having opposite first and second major surfaces. The method further includes micro-replicating elongated structures on the first major surface of the first substrate to obtain a light diffuser. Further, the method includes micro-replicating a microstructured film including light transmissive regions alternated with channels on the second major surface of the first substrate. Further, the method includes filling the channels of the microstructured film with a light absorbing material to obtain a light control film.

[0007] The details of one or more examples of the disclosure are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the disclosure will be apparent from the description and drawings, and from the claims.Brief Description of the Drawings

[0008] Exemplary embodiments disclosed herein may be more completely understood in consideration of the following detailed description in connection with the following figures. The figures are not necessarily drawn to scale. Like numbers used in the figures refer to like components. However, it will be understood that the use of a number to refer to a component in a given figure is not intended to limit the component in another figure labeled with the same number.

[0009] FIG. 1 shows a schematic sectional view of a light control film (LCF), according to an embodiment of the present disclosure;

[0010] FIG. 2A shows an exemplary graph depicting an axial transmission versus aperture ratio in different samples of an LCF with symmetrical light absorbing regions;

[0011] FIG. 2B shows an exemplary graph depicting a relative luminance at 25 degrees versus cut-off angle in the different samples of the LCF with the symmetrical light absorbing regions;

[0012] FIG. 2C shows an exemplary graph depicting a full width at half max (FWHM) versus viewing angle in the different samples of the LCF with the symmetrical light absorbing regions;

[0013] FIG. 2D shows an exemplary graph depicting an axial transmission versus relative luminance at 25 degrees in the different samples of the LCF with the symmetrical light absorbing regions;

[0014] FIG. 3 A shows an exemplary graph depicting the axial transmission versus aperture ratio in different samples of an LCF with asymmetrical light absorbing regions;

[0015] FIG. 3B shows an exemplary graph depicting the relative luminance at 25 degrees versus cut-off angle in the different samples of the LCF with the asymmetrical light absorbing regions;

[0016] FIG. 3C shows an exemplary graph depicting the FWHM versus viewing angle in the different samples of the LCF with the asymmetrical light absorbing regions;

[0017] FIG. 3D shows an exemplary graph depicting the axial transmission versus relative luminance at 25 degrees in the different samples of the LCF with the asymmetrical light absorbing regions;

[0018] FIGS. 4A and 4B show schematic views of exemplary vehicles;

[0019] FIG. 5 A shows a schematic sectional view of an optical construction, according to an embodiment of the present disclosure;

[0020] FIG. 5B shows a schematic sectional view of the LCF and a substantially collimated substantially normally incident light and a substantially collimated incident light, according to an embodiment of the present disclosure;

[0021] FIG. 6 shows a schematic perspective view of the display system, according to an embodiment of the present disclosure;

[0022] FIG. 7 A shows an exemplary graph depicting an optical transmission versus viewing angle of the display system including a light diffuser, without a light diffuser, and including a conventional light diffuser;

[0023] FIG. 7B shows an exemplary magnified graph depicting a normalized transmission versus viewing angle of the display system including the light diffuser, without the light diffuser, and including the conventional light diffuser;

[0024] FIG. 7C shows an exemplary magnified view of elongated structures of the light diffuser;

[0025] FIG. 8 shows a flowchart for a method for making the optical construction, according to an embodiment of the present disclosure; and

[0026] FIG. 9 shows a schematic view depicting steps of the method, according to an embodiment of the present disclosure.Detailed Description

[0027] In the following description, reference is made to the accompanying figures that form a part thereof and in which various embodiments are shown by way of illustration. It is to beunderstood that other embodiments are contemplated and may be made without departing from the scope or spirit of the present disclosure. The following detailed description, therefore, is not to be taken in a limiting sense.

[0028] In the following disclosure, the following definitions are adopted.

[0029] As used herein, all numbers should be considered modified by the term “about”. As used herein, “a,” “an,” “the,” “at least one,” and “one or more” are used interchangeably.

[0030] As used herein as a modifier to a property or attribute, the term “generally”, unless otherwise specifically defined, means that the property or attribute would be readily recognizable by a person of ordinary skill but without requiring absolute precision or a perfect match (e.g., within + / -20% for quantifiable properties).

[0031] The term “substantially”, unless otherwise specifically defined, means to a high degree of approximation (e.g., within + / - 10% for quantifiable properties) but again without requiring absolute precision or a perfect match.

[0032] The term “about”, unless otherwise specifically defined, means to a high degree of approximation (e.g., within + / - 5% for quantifiable properties) but again without requiring absolute precision or a perfect match.

[0033] As used herein, the terms “first” and “second” are used as identifiers. Therefore, such terms should not be construed as limiting of this disclosure. The terms “first” and “second” when used in conjunction with a feature or an element can be interchanged throughout the embodiments of this disclosure.

[0034] As used herein, “at least one of A and B” should be understood to mean “only A, only B, or both A and B”.

[0035] Light control films (LCF) are configured to regulate transmission of light. LCFs typically include a light transmissive film having a plurality of light absorbing regions that include a lightabsorbing material. The LCFs can be placed proximate a surface, such as a display surface, an image surface, or any other surface including an image to be viewed. Typically, the LCFs provide a symmetric light output with a maximum optical transmission such as a peak brightness at a center or on-axis (i.e., near a central viewing angle) and falls off gradually at wider angles. The aforesaid LCFs can provide privacy (e.g., for laptops, ATM) or safety (e.g., for windshield light reflection mitigation in cars).

[0036] However, in certain applications such as in displays of a vehicle, the LCFs may be required to provide and regulate the maximum optical transmission at off-axis / away from the center. In such applications, control on the visibility of information appearing in the display towards occupants that are positioned away from the center, for example, to provide desired visual information to a driver or a passenger in the vehicle, or to avoid distraction of the driver, is desired.

[0037] The present disclosure relates to a light control film (LCF). The LCF includes a light input surface and a light output surface opposite the light input surface. The LCF further includesalternating light transmissive regions and light absorbing regions disposed between the light input surface and the light output surface. The light absorbing regions extend along a same in-plane first direction and arranged along an in-plane orthogonal second direction. Each of the light absorbing regions have opposite top and bottom surfaces and first and second sidewalls extending between the top and bottom surfaces. The first sidewall is inclined at a first inclination angle with respect to a normal from the bottom surface along the second direction. Further, the second sidewall is inclined at a second inclination angle with respect to the normal along the second direction. The second inclination angle is greater than the first inclination angle.

[0038] The light control film of the present disclosure may provide a maximum optical transmission or a peak transmission towards one side of the LCF at an off-axis location (i.e., towards one side of an on-axis location), which may be desired in display systems of vehicles. Specifically, the first sidewall inclined at the first inclination angle and the second sidewall inclined at the second inclination angle different from the first inclination angle may provide the maximum optical transmission toward the one side of the on-axis location and reduce an optical transmission towards the on-axis location and the other side of the on-axis location. Therefore, the LCF may be suitable for applications in which an intended viewer sitting in front or at the one side of the on-axis location, such as in the display systems of the vehicles.

[0039] Referring now to figures, FIG. 1 shows a schematic sectional view of a light control film (LCF) 100, according to an embodiment of the present disclosure.

[0040] A coordinate system including mutually perpendicular x, y, and z-axes is also illustrated in FIG. 1. The x and y-axes are in-plane axes of the LCF 100, while the z-axis is a transverse axis disposed along a thickness of the LCF 100. In other words, the x and y-axes are along a plane of the LCF 100 defining a x-y plane, and the z-axis is perpendicular to the x-y plane of the LCF 100.

[0041] The LCF 100 includes a light input surface 102 and a light output surface 104 opposite the light input surface 102. The LCF 100 further includes alternating light transmissive regions 134 and light absorbing regions 136 disposed between the light input surface 102 and the light output surface 104. The light absorbing regions 136 extend along a same in-plane first direction and arranged along an in-plane orthogonal second direction SD. In some embodiments, the same in-plane first direction may extend substantially along the y-axis and the in-plane orthogonal second direction SD may extend substantially along the x-axis.

[0042] Each of the light absorbing regions 136 have opposite top and bottom surfaces 140, 142 and first and second sidewalls 144, 146 extending between the top and bottom surfaces 140, 142. In the illustrated embodiment of FIG. 1, the first sidewall 144 is inclined at a first inclination angle 91 with respect to a normal N from the bottom surface 142 along the second direction SD and the second sidewall 146 is inclined at a second inclination angle 92 with respect to the normal N along the second direction SD.

[0043] As is apparent from FIG. 1, the second inclination angle 92 and the first inclination angle 91 are different. Specifically, the second inclination angle 92 is greater than the first inclination angle 91. In some embodiments, the second inclination angle 92 is greater than the first inclination angle 91 by about 0.5 degrees, about 1 degree, about 1.5 degrees, about 2 degrees, about 2.5 degrees, about 3 degrees, about 3.5 degrees, about 4 degrees, about 4.5 degrees, or about 5 degrees.

[0044] In some embodiments, the light absorbing regions 136 have a pitch P extending between the first sidewalls 144 of adjacent light absorbing regions 136. Further, the light transmissive regions 134 have a minimum channel width C defined between the first and second sidewalls 144, 146 of the adjacent light absorbing regions 136.

[0045] In some embodiments, a ratio between the minimum channel width C and the pitch P is greater than or equal to about 0.5, i.e., C / P > 0.5. In some embodiments, C / P > 0.55, C / P > 0.6, C / P > 0.65, C / P > 0.7, or C / P > 0.75. In some embodiments, the ratio between the minimum channel width C and the pitch P is interchangeably referred to as “the aperture ratio 106” of the LCF 100 herein.

[0046] In some embodiments, the light absorbing regions 136 have a cut-off angle 9c defined between the normal N extending from a first point 150 on a first light absorbing region 136-1 in the light absorbing regions 136 to a second point 152 on an adjacent second light absorbing region 136-2 in the light absorbing regions 136 facing the second sidewall 146 of the first light absorbing region 136-1. The first point 150 is an intersection between the second sidewall 146 and the bottom surface 142 of the first light absorbing region 136-1. Further, the second point 152 is an intersection between the first sidewall 144 and the top surface 140 of the second light absorbing region 136-2.

[0047] In some embodiments, the cut-off angle 9c is less than or equal to about 15 degrees. In some embodiments, the cut-off angle 9c is less than or equal to about 14 degrees, less than or equal to about 12 degrees, less than or equal to about 10 degrees, or less than or equal to about 8 degrees.

[0048] In some embodiments, the light absorbing regions 136 have an angle 9w defined between the normal N extending from a third point 154 on the first light absorbing region 136-1 in the light absorbing regions 136 to a fourth point 156 on an adjacent third light absorbing region 136-3 in the light absorbing regions 136 facing the first sidewall 144 of the first light absorbing region 136-1. The third point 154 is an intersection between the first sidewall 144 and the bottom surface 142 of the first light absorbing region 136-1. Further, the fourth point 156 is an intersection between the second sidewall 146 and the top surface 140 of the third light absorbing region 136-3.

[0049] In some embodiments, a sum of the cut-off angle 9c and the angle 9w defines a viewing angle 9v. In some embodiments, the viewing angle 9v is greater than or equal to about 20 degrees and less than or equal to about 30 degrees. In some embodiments, the viewing angle 9v about 25 degrees.

[0050] In some embodiments, a line 135 joining centers of the top and bottom surfaces 140, 142 is inclined at a tilt angle 9t of about greater than or equal to about 1 degree. In some embodiments, the line 135 joining the centers of the top and bottom surfaces 140, 142 is inclined at the tilt angle 9tof about greater than or equal to about 1.5 degrees, greater than or equal to about 2 degrees, greater than or equal to about 2.5 degrees, or greater than or equal to about 3 degrees.

[0051] In the illustrated embodiment of FIG. 1, each of the light absorbing regions 136 has a minimum tip width T of at least about 5 micrometers (um). In some embodiments, the minimum tip width T is at least about 5.5 um, at least about 6 um, at least about 6.5, um at least about 7 um, at least about 7.5, um at least about 8 um, at least about 8.5 um, at least about 9 um, at least about 9.5 um, or at least about 10 um.

[0052] In some embodiments, each of the light absorbing regions 136 has a height H of at least about 100 um. In some embodiments, the height H is at least about 110 um, at least about 120 um, at least about 130 um, at least about 140 um, or at least about 150 um.

[0053] In some embodiments, each of the light absorbing regions 136 has a base width B of at least about 10 um. In some embodiments, the base width B is at least about 12 um, at least about 14 um, at least about 16 um, at least about 18 um, or at least about 20 um.

[0054] In some embodiments, the first sidewall 144 of the light absorbing regions 136 extends from the minimum tip width T to a first base width B 1 of at least about 1 um, at least about 2 um, at least about 3 um, or at least about 4 um. Further, the second sidewall 146 of the light absorbing regions 136 extends from the minimum tip width T to a second base width B2 of at least about 2 um, at least about 4 um, at least about 6 um, at least about 8 um, or at least about 10 um.

[0055] Table 1 provided below includes different metrics and actual performance of different samples SI, S2, S3, S4, and S5 of a light control film with symmetrical light absorbing regions.Table 1

[0057] Table 2 provided below includes different metrics and actual performance of different samples S21, S22, S23, S24, and S25 of a light control film (e.g., the LCF 100) with asymmetrical light absorbing regions (e.g., the light absorbing regions 136).Table 2

[0058] Table 3 provided below includes different metrics and actual performance of a sample S31 of a light control film (e.g., the LCF 100) with asymmetrical light absorbing regions (e.g., the light absorbing regions 136).Table 3

[0059] FIG. 2A shows an exemplary graph 500 depicting an axial transmission versus aperture ratio in the samples SI, S2, S3, S4, S5 provided in Table 1 and the sample S21 provided in Table 2.

[0060] The aperture ratio 106 is expressed in percentage (%) in the abscissa. The axial transmission is also expressed in percentage (%) in the ordinate.

[0061] The graph 500 includes a point 501 depicting the axial transmission versus the aperture ratio 106 for the sample SI. The aperture ratio 106 of the sample SI is about 69.9%. The axial transmission of the sample SI is about 74%.

[0062] The graph 500 further includes a point 502 depicting the axial transmission versus the aperture ratio 106 for the sample S2. The aperture ratio 106 of the sample S2 is about 68.6%. The axial transmission of the sample S2 is about 74%.

[0063] The graph 500 further includes a point 503 depicting the axial transmission versus the aperture ratio 106 for the sample S3. The aperture ratio 106 of the sample S3 is about 63.9%. The axial transmission of the sample S3 is about 66%.

[0064] The graph 500 further includes a point 504 depicting the axial transmission versus the aperture ratio 106 for the sample S4. The aperture ratio 106 of the sample S4 is about 56.0%. The axial transmission of the sample S4 is about 63%.

[0065] The graph 500 further includes a point 505 depicting the axial transmission versus the aperture ratio 106 for the sample S5. The aperture ratio 106 of the sample S5 is about 67.2%. The axial transmission of the sample S5 is about 74%.

[0066] Furthermore, for comparison purposes, the graph 500 includes a point 506 depicting the axial transmission versus the aperture ratio 106 for the sample S21. The aperture ratio 106 of the sample S21 is about 59%. The axial transmission of the sample S21 is about 63%.

[0067] As is apparent from the graph 500, the axial transmission may increase as the aperture ratio 106 (shown in FIG. 1) increases. Further, as is apparent from the points 501, 502, 505, the axial transmission may not always increase as the aperture ratio 106 increases.

[0068] FIG. 2B shows an exemplary graph 510 depicting a relative luminance at 25 degrees versus the cut-off angle 9c in the samples SI, S2, S3, S4, S5 provided in Table 1 and the sample S21 provided in Table 2.

[0069] The cut-off angle 9c is expressed in degrees in the abscissa. The relative luminance at 25 degrees is expressed in percentage (%) in the ordinate.

[0070] The graph 510 includes a point 511 depicting the relative luminance at 25 degrees versus the cut-off angle 9c for the sample SI. The cut-off angle 9c of the sample SI is about 13.97 degrees. The relative luminance at 25 degrees of the sample SI is about 3.7%.

[0071] The graph 510 includes a point 512 depicting the relative luminance at 25 degrees versus the cut-off angle 9c for the sample S2. The cut-off angle 9c of the sample S2 is about 12.83 degrees. The relative luminance at 25 degrees of the sample S2 is about 3.9%.

[0072] The graph 510 includes a point 513 depicting the relative luminance at 25 degrees versus the cut-off angle 9c for the sample S3. The cut-off angle 9c of the sample S3 is about 12.07 degrees. The relative luminance at 25 degrees of the sample S3 is about 3.0%.

[0073] The graph 510 includes a point 514 depicting the relative luminance at 25 degrees versus the cut-off angle 9c for the sample S4. The cut-off angle 9c of the sample S4 is about 10.80 degrees. The relative luminance at 25 degrees of the sample S4 is about 1.6%.

[0074] The graph 510 includes a point 515 depicting the relative luminance at 25 degrees versus the cut-off angle 9c for the sample S5. The cut-off angle 9c of the sample S5 is about 11.83 degrees. The relative luminance at 25 degrees of the sample S5 is about 2.8%.

[0075] Furthermore, for comparison purposes, the graph 510 includes a point 516 depicting the relative luminance at 25 degrees versus the cut-off angle 9c for the sample S21. The cut-off angle 9c of the sample S21 is about 11.11 degrees. The relative luminance at 25 degrees of the sample S21 is about 1.1%.

[0076] As is apparent from the graph 510, the relative luminance at 25 degrees may decrease as the cut-off angle 9c decreases. Further, as is apparent from the points 511 and 516, the relative luminance at 25 degrees may decrease when the light control film (e.g., the LCF 100 shown in FIG. 1) has the asymmetrical light absorbing regions (e.g., the light absorbing regions 136 shown in FIG. 1). A lower relative luminance at 25 degrees may be desired in applications where an optical transmission from a display (e.g., in a vehicle) toward one side of an on-axis location (e.g., at 25 degrees) is not desired (e.g., toward a driver of the vehicle) and an intended viewer (e.g., a passenger of the vehicle) is sitting in front or at the other side of the on-axis location.

[0077] FIG. 2C shows an exemplary graph 520 depicting a full width at half max (FWHM) versus the viewing angle 9v in the samples SI, S2, S3, S4, S5 provided in Table 1 and the sample S21 provided in Table 2.

[0078] The viewing angle 9v is expressed in degrees in the abscissa. The FWHM is expressed in percentage (%) in the ordinate.

[0079] The graph 520 includes a point 521 depicting the FWHM versus the viewing angle 9v for the sample SI. The viewing angle 9v of the sample SI is about 27.94 degrees. The FWHM of the sample SI is about 24.89%.

[0080] The graph 520 includes a point 522 depicting the FWHM versus the viewing angle 9v for the sample S2. The viewing angle 9v of the sample S2 is about 25.65 degrees. The FWHM of the sample S2 is about 23.58%.

[0081] The graph 520 includes a point 523 depicting the FWHM versus the viewing angle 9v for the sample S3. The viewing angle 9v of the sample S3 is about 24.14 degrees. The FWHM of the sample S3 is about 21.95%.

[0082] The graph 520 includes a point 524 depicting the FWHM versus the viewing angle 9v for the sample S4. The viewing angle 9v of the sample S4 is about 21.60 degrees. The FWHM of the sample S4 is about 20.40%.

[0083] The graph 520 includes a point 525 depicting the FWHM versus the viewing angle 9v for the sample S5. The viewing angle 9v of the sample S5 is about 23.67 degrees. The FWHM of the sample S5 is about 21.31%.

[0084] Furthermore, for comparison purposes, the graph 520 includes a point 526 depicting the FWHM versus the viewing angle 9v for the sample S21. The viewing angle 9v of the sample S21 is about 26.02 degrees. The FWHM of the sample S21 is about 23%.

[0085] As is apparent from the graph 520, the FWHM may increase as the viewing angle 9v increases.

[0086] FIG. 2D shows an exemplary graph 530 depicting the axial transmission versus the relative luminance at 25 degrees in the samples SI, S2, S3, S4, S5 provided in Table 1 and the sample S21 provided in Table 2.

[0087] The relative luminance at 25 degrees is expressed in percentage (%) in the abscissa. The axial transmission is also expressed in percentage (%) in the ordinate.

[0088] The graph 530 includes a point 531 depicting the axial transmission versus the relative luminance at 25 degrees for the sample S 1. The relative luminance at 25 degrees of the sample S 1 is about 3.7%. The axial transmission of the sample SI is about 74%.

[0089] The graph 530 includes a point 532 depicting the axial transmission versus the relative luminance at 25 degrees for the sample S2. The relative luminance at 25 degrees of the sample S2 is about 3.9%. The axial transmission of the sample S2 is about 74%.

[0090] The graph 530 includes a point 533 depicting the axial transmission versus the relative luminance at 25 degrees for the sample S3. The relative luminance at 25 degrees of the sample S3 is about 3.0%. The axial transmission of the sample S3 is about 66%.

[0091] The graph 530 includes a point 534 depicting the axial transmission versus the relative luminance at 25 degrees for the sample S4. The relative luminance at 25 degrees of the sample S4 is about 1.6%. The axial transmission of the sample S4 is about 63%.

[0092] The graph 530 includes a point 535 depicting the axial transmission versus the relative luminance at 25 degrees for the sample S5. The relative luminance at 25 degrees of the sample S5 is about 2.8%. The axial transmission of the sample S5 is about 74%.

[0093] Furthermore, for comparison purposes, the graph 530 includes a point 536 depicting the axial transmission versus the relative luminance at 25 degrees for the sample S21. The relative luminance at 25 degrees of the sample S21 is about 1.1%. The axial transmission of the sample S21 is about 63%.

[0094] As is apparent from the points 532, 533, 534, the relative luminance at 25 degrees may decrease when the minimum tip width T (shown in FIG. 1) of the light absorbing regions 136 (shown in FIG. 1) is increased. Further, as is apparent from the points 532, 535, the relative luminance at 25 degrees may decrease when the height H (shown in FIG. 1) of the light absorbing regions 136 is increased. However, an LCF including light absorbing regions with large height maybe difficult to manufacture using traditional tools or manufacturing processes. Further, increasing the minimum tip width T may negatively impact the axial transmission and the FWHM. A lower axial luminance and the FWHM may negatively impact a viewing experience of the intended viewer. Specifically, the lower axial luminance and the FWHM may negatively impact a brightness and a uniformity of the display.

[0095] Further, as is apparent from the points 531, 536 for the respective samples SI and S21 having a same value of the minimum tip width T and the height H, the relative luminance at 25 degrees may decrease when the LCF includes the asymmetrical light absorbing regions.

[0096] FIG. 3 A shows an exemplary graph 600 depicting the axial transmission versus the aperture ratio 106 in the samples S21, S22, S23, S24, S25 provided in Table 2.

[0097] The aperture ratio 106 is expressed in percentage (%) in the abscissa. The axial transmission is also expressed in percentage (%) in the ordinate.

[0098] The graph 600 includes a point 601 depicting the axial transmission versus the aperture ratio 106 for the sample S21. The aperture ratio 106 of the sample S21 is about 59%. The axial transmission of the sample S21 is about 63%.

[0099] The graph 600 includes a point 602 depicting the axial transmission versus the aperture ratio 106 for the sample S22. The aperture ratio 106 of the sample S22 is about 57%. The axial transmission of the sample S22 is about 63%.

[0100] The graph 600 includes a point 603 depicting the axial transmission versus the aperture ratio 106 for the sample S23. The aperture ratio 106 of the sample S23 is about 60%. The axial transmission of the sample S23 is about 63%.

[0101] The graph 600 includes a point 604 depicting the axial transmission versus the aperture ratio 106 for the sample S24. The aperture ratio 106 of the sample S24 is about 52%. The axial transmission of the sample S24 is about 56%.

[0102] The graph 600 includes a point 605 depicting the axial transmission versus the aperture ratio 106 for the sample S25. The aperture ratio 106 of the sample S25 is about 64%. The axial transmission of the sample S25 is about 69%.

[0103] FIG. 3B shows an exemplary graph 610 depicting the relative luminance at 25 degrees versus the cut-off angle 9c in the samples S21, S22, S23, S24, S25 provided in Table 2.

[0104] The cut-off angle 9c is expressed in degrees in the abscissa. The relative luminance at 25 degrees is expressed in percentage (%) in the ordinate.

[0105] The graph 610 includes a point 611 depicting the relative luminance at 25 degrees versus the cut-off angle 9c for the sample S21. The cut-off angle 9c of the sample S21 is about 11.11 degrees. The relative luminance at 25 degrees of the sample S21 is about 1.1%.

[0106] The graph 610 includes a point 612 depicting the relative luminance at 25 degrees versus the cut-off angle 9c for the sample S22. The cut-off angle 9c of the sample S22 is about 9.93 degrees. The relative luminance at 25 degrees of the sample S22 is about 0.9%.

[0107] The graph 610 includes a point 613 depicting the relative luminance at 25 degrees versus the cut-off angle 9c for the sample S23. The cut-off angle 9c of the sample S23 is about 9.93 degrees. The relative luminance at 25 degrees of the sample S23 is about 0.9%.

[0108] The graph 610 includes a point 614 depicting the relative luminance at 25 degrees versus the cut-off angle 9c for the sample S24. The cut-off angle 9c of the sample S24 is about 9.16 degrees. The relative luminance at 25 degrees of the sample S24 is about 0.6%.

[0109] The graph 610 includes a point 615 depicting the relative luminance at 25 degrees versus the cut-off angle 9c for the sample S25. The cut-off angle 9c of the sample S25 is about 11.11 degrees. The relative luminance at 25 degrees of the sample S25 is about 1.2%.

[0110] FIG. 3C shows an exemplary graph 620 depicting the FWHM versus the viewing angle 9v in the samples S21, S22, S23, S24, S25 provided in Table 2.

[0111] The viewing angle 9v is expressed in degrees in the abscissa. The FWHM is expressed in percentage (%) in the ordinate.

[0112] The graph 620 includes a point 621 depicting the FWHM versus the viewing angle 9v for sample S21. The viewing angle 9v of the sample S21 is about 26.02 degrees. The FWHM of the sample S21 is about 23%.

[0113] The graph 620 includes a point 622 depicting the FWHM versus the viewing angle 9v for sample S22. The viewing angle 9v of the sample S22 is about 23.71 degrees. The FWHM of the sample S22 is about 21%.

[0114] The graph 620 includes a point 623 depicting the FWHM versus the viewing angle 9v for sample S23. The viewing angle 9v of the sample S23 is about 24.18 degrees. The FWHM of the sample S23 is about 22%.

[0115] The graph 620 includes a point 624 depicting the FWHM versus the viewing angle 9v for sample S24. The viewing angle 9v of the sample S24 is about 22.18 degrees. The FWHM of the sample S24 is about 22%.

[0116] The graph 620 includes a point 625 depicting the FWHM versus the viewing angle 9v for sample S25. The viewing angle 9v of the sample S25 is about 24.13 degrees. The FWHM of the sample S25 is about 21%.

[0117] FIG. 3D shows an exemplary graph 630 depicting the axial transmission versus the relative luminance at 25 degrees in the samples S21, S22, S23, S24, S25 provided in Table 2.

[0118] The relative luminance at 25 degrees is expressed in percentage (%) in the abscissa. The axial transmission is also expressed in percentage (%) in the ordinate.

[0119] The graph 630 includes a point 631 depicting the axial transmission versus the relative luminance at 25 degrees for the sample S21. The relative luminance at 25 degrees of the sample S21 is about 1.1%. The axial transmission of the sample S21 is about 63%.

[0120] The graph 630 includes a point 632 depicting the axial transmission versus the relative luminance at 25 degrees for the sample S22. The relative luminance at 25 degrees of the sample S22 is about 0.9%. The axial transmission of the sample S22 is about 63%.

[0121] The graph 630 includes a point 633 depicting the axial transmission versus the relative luminance at 25 degrees for the sample S23. The relative luminance at 25 degrees of the sample S23 is about 0.9% degrees. The axial transmission of the sample S23 is about 63%.

[0122] The graph 630 includes a point 634 depicting the axial transmission versus the relative luminance at 25 degrees for the sample S24. The relative luminance at 25 degrees of the sample S24 is about 0.6%. The axial transmission of the sample S24 is about 56%.

[0123] The graph 630 includes a point 635 depicting the axial transmission versus the relative luminance at 25 degrees for the sample S25. The relative luminance at 25 degrees of the sample S25 is about 1.2%. The axial transmission of the sample S25 is about 69%.

[0124] Furthermore, the graph 630 includes a point 636 depicting the axial transmission versus the relative luminance at 25 degrees for the sample S31. The relative luminance at 25 degrees of the sample S31 is about 0.75%. The axial transmission of the sample S31 is about 60%.

[0125] Further, the graph 630 includes the points 531, 532, 533, 534, 535 of the graph 530 of FIG. 2D for comparison purposes.

[0126] As is apparent from the graph 630, the samples S21, S22, S23, S24, S25 with the asymmetrical light absorbing regions have a lower relative luminance at 25 degrees than the samples SI, S2, S3, S4, S5 with the symmetrical light absorbing regions. Further, as is apparent from the points 634 and 635, the relative luminance at 25 degrees may decrease as the tilt angle 9t (shown in FIG. 1) increases.

[0127] Further, as is apparent from the point 636, the LCF 100 may be designed as per desired application attributes by varying the tilt angle 9t (e.g., by varying the first inclination angle 91 and thesecond inclination angle 92 shown in FIG. 1), while keeping the minimum tip width T and the height H within reasonable limits.

[0128] FIGS. 4A and 4B show schematic views of exemplary vehicles 400. In some embodiments, the vehicle 400 may have first and second occupants 402, 404. In some embodiments, the first occupant 402 of the vehicle 400 is a driver of the vehicle 400 and the second occupant 404 of the vehicle 400 is a passenger of the vehicle 400.

[0129] In some embodiments, the vehicle 400 is a car 410 as shown in FIG. 4 A. In some embodiments, the vehicle 400 is a truck 410a, a bus 410b, a train 410c, a ship 410d, a boat 410e, an airplane 410f, or a helicopter 410g.

[0130] FIG. 5 A shows a schematic sectional view of an optical construction 300, according to an embodiment of the present disclosure. In the illustrated embodiment of FIG. 5 A, the optical construction 300 includes a display system 200 for use in the vehicle 400 shown in FIGS. 4A and 4B.

[0131] The display system 200 includes a display 10 configured to form and emit an image light 11 for viewing by an eye 402e, 404e of the one or more occupants i.e., the first and / or second occupants 402, 404 of the vehicle 400.

[0132] In some embodiments, the display 10 includes an organic light emitting diode (OLED) display. In some embodiments, the display 10 includes a liquid crystal display (LCD) panel.

[0133] In some embodiments, the one of the one or more occupants of the vehicle 400 is the driver of the vehicle 400. In some embodiments, the one of the one or more occupants of the vehicle 400 is the passenger of the vehicle 400.

[0134] The LCF 100 is disposed on the display 10, such that the light input surface 102 faces the display 10 and the light output surface 104 faces the eye 402e, 404e of the one or more occupants of the vehicle 400. Further, the eye 402e, 404e of the one or more occupants of the vehicle 400 is disposed in a first incident plane 160 (shown in FIG. 5B) extending along the second direction SD. Furthermore, the LCF 100 is configured to receive the emitted image light 11 and transmit the image light 11 toward the one or more occupants. As shown, the first incident plane 160 is a x-z plane.

[0135] In some embodiments, in the first incident plane 160, the display system 200 has a relative luminance at an angle greater than about 20 degrees from the display 10 of less than about 5 percent. In some embodiments, in the first incident plane 160, the display system 200 has the relative luminance at the angle greater than about 20 degrees from the display 10 of less than about 4 percent, less than about 3 percent, less than about 2 percent, less than about 1 percent, less than about 0.8 percent, less than about 0.6 percent, or less than about 0.5 percent.

[0136] In some embodiments, the eye 402e of the first occupant 402 of the one or more occupants of the vehicle 400 is positioned in a first viewing space 210 in the first incident plane 160 disposed at the angle of greater than about 20 degrees from the display 10 allowing the first occupant 402 to view the image light 11 having a first relative luminance of less than about 5 percent.

[0137] In some embodiments, the eye 402e of the first occupant 402 of the one or more occupants of the vehicle 400 is positioned in the first viewing space 210 in the first incident plane 160 disposed at the angle of greater than about 20 degrees from the display 10 allowing the first occupant 402 to view the image light 11 having the first relative luminance of less than about 4 percent, less than about 3 percent, less than about 2 percent, less than about 1 percent, less than about 0.8 percent, less than about 0.6 percent, or less than about 0.5 percent.

[0138] Further, in some embodiments, the eye 404e of the second occupant 404 of the one or more occupants of the vehicle 400 is positioned in a non-overlapping second viewing space 220 in the first incident plane 160 that is at least partially in front of the display 10 allowing the second occupant 404 to view the image light 11 having a second relative luminance greater than about 50 percent.

[0139] Further, in some embodiments, the eye 404e of the second occupant 404 of the one or more occupants of the vehicle 400 is positioned in the non-overlapping second viewing space 220 in the first incident plane 160 that is at least partially in front of the display 10 allowing the second occupant 404 to view the image light 11 having the second relative luminance greater than about 50 percent, greater than about 55 percent, greater than about 60 percent, greater than about 65 percent, greater than about 70 percent, greater than about 75 percent, or greater than about 80 percent.

[0140] In some embodiments, the display system 200 further includes a light diffuser 120 disposed on the LCF 100 opposite to the display 10. The light diffuser 120 may add haze to the display system 200 which may avoid wet-out and may reduce an effect of optical artifacts due to one or more defects in one or more components of the display system 200.

[0141] In some embodiments, the display system 200 further includes a first substrate 110 disposed between the LCF 100 and the light diffuser 120. In some embodiments, the display system 200 further includes a second substrate 112 disposed on the LCF 100 opposite to the first substrate 110.

[0142] FIG. 5B shows a schematic view of the LCF 100 and a substantially collimated substantially normally incident light 90 and a substantially collimated incident light 91, according to an embodiment of the present disclosure.

[0143] Referring to FIGS. 1 and 5B, in some embodiments, for the substantially normally incident light 90 propagating in the first incident plane 160 extending along the second direction SD, the LCF 100 transmits greater than or equal to about 50% of the incident light 90 (also shown as an axial transmission AT in FIG. 5A). In some embodiments, for the substantially normally incident light 90 propagating in the first incident plane 160 extending along the second direction SD, the LCF 100 transmits greater than or equal to about 60%, greater than or equal to about 70%, greater than or equal to about 80% of the incident light 90.

[0144] For the substantially collimated incident light 91 propagating in the first incident plane 160 extending along the second direction SD, the LCF 100 transmits greater than or equal to about 50% of the incident light 91. For the substantially collimated incident light 91 propagating in the firstincident plane 160 extending along the second direction SD, the LCF 100 transmits greater than or equal to about 60%, greater than or equal to about 70%, greater than or equal to about 80% of the incident light 91.

[0145] In some embodiments, for the substantially collimated incident light 91 propagating in the first incident plane 160 extending along the second direction SD and incident on the LCF 100 at a peak angle Op (shown in FIG. 5B) of greater than or equal to about 5 degrees and less than or equal to about 10 degrees, the LCF 100 transmits greater than or equal to about 60% of the incident light 91 (also shown as a peak transmission PT in FIG. 5A).

[0146] In some embodiments, for the substantially collimated incident light 91 propagating in the first incident plane 160 extending along the second direction SD and incident on the LCF 100 at the peak angle Op of greater than or equal to about 5 degrees and less than or equal to about 10 degrees, the LCF 100 transmits greater than or equal to about 70%, greater than or equal to about 80%, or greater than or equal to about 90% of the incident light 91.

[0147] For a substantially collimated incident light (not shown) propagating in a second incident plane 170 extending along the first direction, the LCF 100 transmits less than or equal to about 30% of the incident light. In some embodiments, for the substantially collimated incident light propagating in the second incident plane 170 extending along the first direction, the LCF 100 transmits less than or equal to about 25%, or less than or equal to about 20% of the incident light. As shown, the second incident plane 170 is a y-z plane.

[0148] FIG. 6 shows a schematic perspective view of the display system 200, according to an embodiment of the present disclosure. As shown in FIG. 6, the light diffuser 120 includes elongated structures 30 extending substantially along the second direction SD. FIG. 6 further illustrates a light diffusion DI along the first direction and a light diffusion D2 along the second direction SD.

[0149] In some embodiments, the light diffuser 120 is less diffusive along the second direction SD (i.e., substantially along the x-axis) than along the first direction (i.e., substantially along the y-axis). In some embodiments, the light diffuser 120 is at least 30% less diffusive along the second direction SD than along the first direction. In other words, the light diffusion D2 along the second direction SD is at least 30% less than the light diffusion DI along the first direction.

[0150] In some embodiments, the light diffuser 120 is at least 35%, at least 40%, at least 45%, or at least 50% less diffusive along the second direction SD than along the first direction.

[0151] FIG. 7 A shows an exemplary graph 700 depicting an optical transmission versus viewing angle 9v of the display system 200 including the light diffuser 120, without the light diffuser 120, and including a conventional light diffuser.

[0152] The graph 700 includes a curve 702 depicting the optical transmission versus viewing angle 9v of the display system 200 including the LCF 100 and the light diffuser 120.

[0153] The graph 700 includes a curve 704 depicting optical transmission of the display system 200 without the light diffuser 120.

[0154] The graph 700 includes a curve 706 depicting the optical transmission versus viewing angle 9v of the display system 200 including the LCF 100 and the conventional light diffuser.

[0155] FIG. 7B shows an exemplary magnified graph 710 depicting a normalized transmission versus viewing angle 9v of the display system 200 including the light diffuser 120, without the light diffuser 120, and including the conventional light diffuser.

[0156] The graph 710 includes a curve 712 depicting the normalized transmission versus viewing angle 9v of the display system 200 including the conventional light diffuser.

[0157] The graph 710 includes a curve 714 depicting the normalized transmission of the display system 200 including the light diffuser 120.

[0158] The graph 710 includes a curve 716 depicting the normalized transmission of the display system 200 without the light diffuser 120.

[0159] Referring to FIGS. 5B, 6, and 7A-7B, as is apparent from the curves 702 and 704, in some embodiments, for the substantially collimated incident light 91 propagating in the first incident plane 160 extending along the second direction SD, an effective transmission of the display system 200 is no more than about 1% as compared to a display system (not shown) that has the same construction except for not including the light diffuser 120.

[0160] FIG. 7C shows an exemplary magnified view 720 of the elongated structures 30 of the light diffuser 120. As shown, the elongated structures 30 are long and have a low slope along one direction and short and having a higher slope along another direction substantially orthogonal to the one direction. Specifically, the elongated structures 30 are long and have the low slope along the second direction SD (shown in FIG. 6) and short and having the higher slope along the first direction (i.e., along the y-axis). Therefore, the elongated structures 30 may scatter light substantially along the first direction which may add a desired haze but may not substantially impact the relative luminance at the angle greater than about 20 degrees.

[0161] Referring to FIGS. 7A to 7C, the light diffuser 120 may add the desired haze to the display system 200 which may avoid the wet-out and may reduce the effect of the optical artifacts due to the one or more defects in the one or more components of the display system 200 shown in FIG.5A, while keeping the optical transmission of the display system 200 at the angle greater than about 20 degrees substantially unchanged. In other words, adding the light diffuser 120 in the display system 200 may not substantially increase the optical transmission of the display system 200 at the angle greater than about 20 degrees while providing the desired haze.

[0162] Further, the light diffuser 120 may have a lower impact on the of the display system 200 at the angle greater than about 20 degrees the conventional light diffuser. This may be because the conventional light diffuser may have a similar light diffusion along the first and second directions. The light diffusion along the second direction SD from the conventional light diffuser may increase the optical transmission of the display system 200 at the angle greater than about 20 degrees, which may not be desired in some applications.

[0163] FIG. 8 shows a flowchart for a method 800 for making the optical construction 300 shown in FIG. 5A, according to an embodiment of the present disclosure. FIG. 9 shows a schematic view depicting steps of the method 800, according to an embodiment of the present disclosure.

[0164] Referring to FIGS. 8 and 9, at step 802, the method 800 includes providing a first substrate (e.g., the first substrate 110) having opposite first and second major surfaces 114, 116.

[0165] At step 804, the method 800 includes micro-replicating elongated structures (e.g., the elongated structures 30) on the first major surface 114 of the first substrate 110 to obtain a light diffuser (e.g., the light diffuser 120).

[0166] At step 806, the method 800 includes micro-replicating a microstructured film 130 including light transmissive regions (e.g., the light transmissive regions 134) alternated with channels 132 on the second major surface 116 of the first substrate 110.

[0167] At step 808, the method 800 includes filling the channels 132 of the microstructured film 130 with a light absorbing material 118 to obtain an LCF (e.g., the LCF 100).

[0168] In some embodiments, the method 800 further includes providing a second substrate (e.g., the second substrate 112) on the LCF opposite to the first substrate.

[0169] In some embodiments, the optical construction 300 may include a hard coat 119.Specifically, in some embodiments, the hard coat 119 may be disposed on the second substrate opposite to the LCF 100.

[0170] Unless otherwise indicated, all numbers expressing feature sizes, amounts, and physical properties used in the specification and claims are to be understood as being modified by the term “about.” Accordingly, unless indicated to the contrary, the numerical parameters set forth in the foregoing specification and attached claims are approximations that can vary depending upon the desired properties sought to be obtained by those skilled in the art utilizing the teachings disclosed herein.

[0171] 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 of the specific embodiments discussed herein. Therefore, it is intended that this disclosure be limited only by the claims and the equivalents thereof.

Claims

CLAIMS1. A light control film (LCF) comprising:a light input surface and a light output surface opposite the light input surface; and alternating light transmissive regions and light absorbing regions disposed between the light input surface and the light output surface, wherein the light absorbing regions extend along a same inplane first direction and arranged along an in-plane orthogonal second direction, each of the light absorbing regions having opposite top and bottom surfaces and first and second sidewalls extending between the top and bottom surfaces, wherein the first sidewall is inclined at a first inclination angle with respect to a normal from the bottom surface along the second direction and the second sidewall is inclined at a second inclination angle with respect to the normal along the second direction, and wherein the second inclination angle is greater than the first inclination angle.

2. The LCF of claim 1, wherein the light absorbing regions have a pitch P extending between the first sidewalls of adjacent light absorbing regions and the light transmissive regions have a minimum channel width C defined between the first and second sidewalls of adjacent light absorbing regions, and wherein C / P is greater than or equal to about 0.5.

3. The LCF of claim 1, wherein for a substantially collimated incident light propagating in a first incident plane extending along the second direction and incident on the LCF at a peak angle of greater than or equal to about 5 degrees and less than or equal to about 10 degrees, the LCF transmits greater than or equal to about 60% of the incident light.

4. The LCF of claim 1, wherein the light absorbing regions have a cutoff angle defined between a normal extending from a first point on a first light absorbing region in the light absorbing regions to a second point on an adjacent second light absorbing region in the light absorbing regions facing the second sidewall of the first light absorbing region, wherein the first point is an intersection between the second sidewall and the bottom surface of the first light absorbing region, and wherein the second point is an intersection between the first sidewall and the top surface of the second light absorbing region.

5. The LCF of claim 4, wherein the cutoff angle is less than or equal to about 15 degrees.

6. A display system for use in a vehicle comprising:a display configured to form and emit an image light for viewing by an eye of one or more occupants of the vehicle; andthe LCF of claim 1 disposed on the display, such that the light input surface faces the display and the light output surface faces the eye of one or more occupants of the vehicle, the eye of one ormore occupants of the vehicle disposed in a first incident plane extending along the second direction, the LCF configured to receive the emitted image light transmit the image light toward the one or more occupants.

7. The display system of claim 6, wherein one of the one or more occupants of the vehicle is a passenger of the vehicle.

8. The display system of claim 6, wherein the eye of a first occupant of the one or more occupants of the vehicle is positioned in a first viewing space in the first incident plane disposed at an angle of greater than about 20 degrees from the display and allowing the first occupant to view the image light having a first relative luminance of less than about 3 percent, and wherein the eye of a second occupant of the one or more occupants of the vehicle is positioned in a non-overlapping second viewing space in the first incident plane that is at least partially in front of the display allowing the second occupant to view the image light having a second relative luminance greater than about 50 percent.

9. A display system for use in a vehicle comprising:a display configured to form and emit an image light for viewing by an eye of one or more occupants of the vehicle; anda light control film (LCF) comprising:a light input surface and a light output surface opposite the light input surface; and alternating light transmissive regions and light absorbing regions disposed between the light input surface and the light output surface, wherein the light absorbing regions extend along a same in-plane first direction and arranged along an in-plane orthogonal second direction, such that the light input surface faces the display and the light output surface faces the eye of one or more occupants of the vehicle, the eye of one or more occupants of the vehicle disposed in a first incident plane extending along the second direction, the LCF configured to receive the emitted image light and transmit the image light toward the one or more occupants, for a substantially collimated incident light propagating in the first incident plane extending along the second direction, the LCF transmits greater than or equal to about 50% of the incident light, andfor a substantially collimated incident light propagating in a second incident plane extending along the first direction, the LCF transmits less than or equal to about 30% of the incident light; anda light diffuser disposed on the LCF opposite to the display, the light diffuser being less diffusive along the second direction than along the first direction.

10. The display system of claim 9, wherein the light diffuser is at least 30% less diffusive along the second direction than along the first direction.

11. The display system of claim 9, wherein for a substantially collimated incident light propagating in a first incident plane extending along the second direction, an effective transmission of the display system is no more than about 1 % as compared to a display system that has the same construction except for not comprising the light diffuser.

12. The display system of claim 9, wherein the eye of a first occupant of the one or more occupants of the vehicle is positioned in a first viewing space in the first incident plane disposed at an angle of greater than about 20 degrees from the display and allowing the first occupant to view the image light having a first relative luminance of less than about 5 percent, and wherein the eye of a second occupant of the one or more occupants of the vehicle is positioned in a non-overlapping second viewing space in the first incident plane that is at least partially in front of the display allowing the second occupant to view the image light having a second relative luminance greater than about 50 percent.

13. The display system of claim 12, wherein the first occupant of the vehicle is a driver of the vehicle.

14. The display system of claim 9, each of the light absorbing regions having opposite top and bottom surfaces, wherein a line joining centers of the top and bottom surfaces is inclined at a tilt angle of about greater than or equal to about 1 degree.

15. The display system of claim 14, wherein the eye of a first occupant of the one or more occupants of the vehicle is positioned in a first viewing space in the first incident plane disposed at an angle of greater than about 20 degrees from the display and allowing the first occupant to view the image light having a first relative luminance of less than about 3 percent, and wherein the eye of a second occupant of the one or more occupants of the vehicle is positioned in a non-overlapping second viewing space in the first incident plane that is at least partially in front of the display allowing the second occupant to view the image light having a second relative luminance greater than about 50 percent.

Images