Heads up display and vehicle

Abstract

A heads up display (HUD) includes an adjustable polarizing reflector and different first and second displays to form and emit respective first and second polarized emitted image lights toward the adjustable polarizing reflector. The first and second polarized emitted image lights have substantially respective first and second polarization states and includes respective first and second polarized emitted images. The HUD forms respective first and second polarized displayed images of the first and second polarized emitted images for viewing by an eye of an occupant of the vehicle. The adjustable polarizing reflector receives and adjustably transmits T1% and adjustably reflects R2% of the first and second polarized emitted image lights as respective first transmitted and second reflected polarized image lights. The HUD includes an optical mirror to receive and reflect at least 10% of the first transmitted and second reflected polarized image lights toward the eye of the occupant.

Description

[0001] HEADS UP DISPLAY AND VEHICLE

[0002] Technical Field

[0003] The present disclosure relates to a heads up display (HUD) and a vehicle including the HUD.

[0004] Background

[0005] A heads up display (HUD) may be used in a vehicle to present various information to one or more occupants on a windshield of the vehicle. A typical HUD may include one or more displays and several components for reflecting and directing emitted lights from the one or more displays to present the various information to the one or more occupants.

[0006] Summary

[0007] In a first aspect, the present disclosure provides a heads up display (HUD) for use in a vehicle. The HUD includes an adjustable polarizing reflector, different first and second displays, and an optical mirror. The adjustable polarizing reflector has adjustable reflectance and transmittance for each of mutually orthogonal first and second polarization states and for at least one same first visible wavelength in a visible wavelength range extending from about 420 nanometers (nm) to about 680 nm. The different first and second displays are configured to form and emit respective first and second polarized emitted image lights toward the adjustable polarizing reflector. The first and second polarized emitted image lights have substantially the respective first and second polarization states and include respective first and second polarized emitted images. The HUD is configured to form respective first and second polarized displayed images of the first and second polarized emitted images for viewing by an eye of a same first occupant of the vehicle. The adjustable polarizing reflector is configured to receive and adjustably transmit Tl% and adjustably reflect R2% of the first and second polarized emitted image lights as respective first transmitted and second reflected polarized image lights, where 30 < R2+T1 < 100. The optical mirror is configured to receive and reflect at least 10% of the first transmitted and second reflected polarized image lights toward the eye of the same first occupant.

[0008] In a second aspect, the present disclosure provides a vehicle. The vehicle includes the HUD of the first aspect.

[0009] In a third aspect, the present disclosure provides a heads up display (HUD) for use in a vehicle. The HUD includes a housing, an adjustable polarizing reflector, and first and second displays. The housing has a top side defining an opening. The adjustable polarizing reflector is at least partially disposed inside the housing and includes an adjustable polarization rotator disposed between first and second reflective polarizers. The adjustable polarization rotator is configured to rotate a polarization of an incident light by a substantially continuously adjustable number of degrees across a continuous range extending from about zero degree up to at least 30 degrees for each of mutually orthogonal first and second polarization states and for at least one same first visible wavelength in a visible wavelength range extending from about 420 nm to about 680 nm. The first and second displays are at least partially disposed inside the housing and are configured to form and emit respective first and second polarized emitted images. The HUD is configured to form respective first and second polarized displayed images of the first and second polarized emitted images for viewing by one or more viewers after the first and second polarized emitted images are respectively transmitted and reflected by the adjustable polarizing reflector.

[0010] 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.

[0011] Brief Description of the Drawings

[0012] 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.

[0013] FIGS. 1A-1B show schematic views of exemplary vehicles;

[0014] FIG. 2 shows a schematic view of a heads up display (HUD), according to an embodiment of the present disclosure;

[0015] FIG. 3 shows a schematic view of a HUD, according to another embodiment of the present disclosure;

[0016] FIG. 4 shows a schematic view of a HUD, according to yet another embodiment of the present disclosure;

[0017] FIG. 5 shows a schematic diagram illustrating a relative placement of first and second displays of the HUD, according to an embodiment of the present disclosure;

[0018] FIGS. 6A-6C show different schematic views of different positionings of first and second polarized displayed images, according to an embodiment of the present disclosure;

[0019] FIG. 7 shows a schematic top view of a display of the HUD, according to an embodiment of the present disclosure;

[0020] FIG. 8 shows a schematic view of an adjustable polarizing reflector of the HUD, according to an embodiment of the present disclosure;

[0021] FIG. 9A-9B show schematic sectional views of the adjustable polarizing reflector of the HUD, according to an embodiment of the present disclosure;

[0022] FIG. 10 shows a schematic detailed sectional view of reflective polarizers of the HUD, according to an embodiment of the present disclosure; and

[0023] FIG. 11 shows a schematic diagram of transmitted and reflected polarized image lights from the adjustable polarizing reflector, according to an embodiment of the present disclosure. Detailed Description

[0024] 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 be understood 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.

[0025] In the following disclosure, the following definitions are adopted.

[0026] 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.

[0027] 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).

[0028] 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.

[0029] 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.

[0030] As used herein, the terms “first” and “second” are used as identifiers. Therefore, such terms should not be constmed 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.

[0031] As used herein, “at least one of A and B” should be understood to mean “only A, only B, or both A and B”.

[0032] A heads up display (HUD) may be used in a vehicle to present various information to one or more occupants on a windshield of the vehicle. A typical HUD may include one or more displays and several components for reflecting and directing emitted lights from the one or more displays to present the various information to the one or more occupants.

[0033] The present disclosure relates to a heads up display (HUD) for use in a vehicle. The HUD includes an adjustable polarizing reflector, different first and second displays, and an optical mirror. The adjustable polarizing reflector has adjustable reflectance and transmittance for each of mutually orthogonal first and second polarization states and for at least one same first visible wavelength in a visible wavelength range extending from about 420 nanometers (nm) to about 680 nm. The different first and second displays are configured to form and emit respective first and second polarized emitted image lights toward the adjustable polarizing reflector. The first and second polarized emitted image lights have substantially the respective first and second polarization states and include respective first and second polarized emitted images. The HUD is configured to form respective first and second polarized displayed images of the first and second polarized emitted images for viewing by an eye of a same first occupant of the vehicle. The adjustable polarizing reflector is configured to receive and adjustably transmit Tl% and adjustably reflect R2% of the first and second polarized emitted image lights as respective first transmitted and second reflected polarized image lights, where 30 < R2+T1 < 100. The optical mirror is configured to receive and reflect at least 10% of the first transmitted and second reflected polarized image lights toward the eye of the same first occupant.

[0034] Therefore, the HUD may enable a dynamic control over a transmission ratio of the first transmitted and second reflected polarized image lights. Specifically, since the adjustable polarizing reflector is configured to receive and adjustably transmit Tl% and adjustably reflect R2% of the first and second polarized emitted image lights as respective first transmitted and second reflected polarized image lights, the HUD may provide up to 100% efficiency for each of the two overlaid images (e.g., the first and second polarized displayed images) with the same polarization state.

[0035] Further, the HUD may provide a depth perception of the first and second polarized displayed images and / or a perception of a three-dimensional single real image by one or more occupants of the vehicle. Thus, the HUD may provide a more immersive information environment and differentiation between information displayed on the first and second polarized displayed images. This may provide a unique experience in terms of how the one or more occupants may receive and interact with the information.

[0036] Referring now to figures, FIGS. 1 A-1B show schematic views of exemplary vehicles 310. The vehicle 310 includes a windshield 50. In some embodiments, the vehicle 310 may have a first occupant. In some embodiments, the first occupant of the vehicle 310 is a driver 320 of the vehicle 310. In some embodiments, the first occupant of the vehicle 310 is a passenger 325 of the vehicle 310.

[0037] In some embodiments, the vehicle 310 is a car as shown in FIG. 1 A, a truck 310a, a bus 310b, a train 310c, a ship 3 lOd, a boat 3 lOe, an airplane 3 lOf, or a helicopter 310g.

[0038] FIG. 2 is a schematic view of a heads up display (HUD) 300 for use in the vehicle 310 shown in FIGS. 1A-1B, according to an embodiment of the present disclosure. In some embodiments, the vehicle 310 includes the HUD 300.

[0039] The HUD 300 includes an adjustable polarizing reflector 10, different first and second displays 20, 30, and an optical mirror 40.

[0040] The adjustable polarizing reflector 10 has adjustable reflectance and transmittance for each of mutually orthogonal first and second polarization states and for at least one same first visible wavelength in a visible wavelength range extending from about 420 nm to about 680 nm.

[0041] In some embodiments, the at least one same first visible wavelength includes at least one same blue wavelength in a blue wavelength range extending from about 420 nm to about 480 nm, at least one same green wavelength in a green wavelength range extending from about 490 nm to about 560 nm, and at least one same red wavelength in a red wavelength range extending from about 590 nm to about 670 nm. In some embodiments, the first polarization state may correspond to an s-polarization state and the second polarization state may correspond to a p-polarization state. The adjustable polarizing reflector 10 includes opposite first and second major sides 11, 12. In the illustrated embodiment of FIG. 2, the first and second displays 20, 30 are disposed on the opposite respective first and second major sides 11, 12 of the adjustable polarizing reflector 10. Specifically, the first display 20 is disposed on the first major side 11 of the adjustable polarizing reflector 10 and the second display 30 is disposed on the second major side 12 of the adjustable polarizing reflector 10.

[0042] In some embodiments, the adjustable polarizing reflector 10 is closer to one of the first and second displays 20, 30 and farther from the other one of the first and second displays 20, 30. In the illustrated embodiment of FIG. 2, the adjustable polarizing reflector 10 is closer to the first display 20 and farther from the second display 30.

[0043] In some embodiments, at least one of the first and second displays 20, 30 includes an organic light emitting diode (OLED) display. In some embodiments, at least one of the first and second displays 20, 30 includes a liquid crystal display (LCD) panel.

[0044] The first and second displays 20, 30 are configured to form and emit respective first and second polarized emitted image lights 21, 31 toward the adjustable polarizing reflector 10. Specifically, the first display 20 is configured to form and emit the first polarized emitted image light 21 toward the adjustable polarizing reflector 10, and the second display 30 is configured to form and emit the second polarized emitted image light 31 toward the adjustable polarizing reflector 10.

[0045] The first and second polarized emitted image lights 21, 31 have substantially the respective first and second polarization states. Further, the first and second polarized emitted image lights 21, 31 include respective first and second polarized emitted images 22, 32. Specifically, the first polarized emitted image light 21 has the first polarization state and includes the first polarized emitted image 22, and the second polarized emitted image light 31 has the second polarization state and includes the second polarized emitted image 32.

[0046] In some embodiments, the first and second displays 20, 30 are configured to emit temporally altematingly the respective first and second polarized emitted images 22, 32. In other words, in some embodiments, the first and second displays 20, 30 are configured to emit the respective first and second polarized emitted images 22, 32 timely sequentially in an alternating manner.

[0047] In some embodiments, at least one of the first and second polarized emitted images 22, 32 includes one or more of a letter, a number, a symbol, a logo, a text, an alphanumeric, a movie, and a picture.

[0048] The first and second polarized emitted images 22, 32 are used to generate respective first and second polarized displayed images 23, 33. Specifically, the first polarized emitted image 22 is used to generate the first polarized displayed image 23 and the second polarized emitted image 32 is used to generate the second polarized displayed image 33. More specifically, the HUD 300 is configured to form the respective first and second polarized displayed images 23, 33 of the first and second polarized emitted images 22, 32 for viewing by an eye 315 of the same first occupant (e.g., the driver 320 or the passenger 325 as shown in FIG. 1 A) of the vehicle 310 (shown in FIG. 1 A). In some embodiments, at least one of the first and second polarized displayed images 23, 33 is a real polarized image. In some embodiments, the real polarized image has substantially a same size as the polarized emitted image 22, 32 in the first and second polarized emitted images 22, 32 that corresponds to the real polarized image. For example, if the first polarized displayed image 23 is the real polarized image, the real polarized image has substantially the same size as the first polarized emitted image 22. Similarly, if the second polarized displayed image 33 is the real polarized image, the real polarized image has substantially the same size as the second polarized emitted image 32.

[0049] The adjustable polarizing reflector 10 is configured to receive the first and second polarized emitted image lights 21, 31 and adjustably transmit and adjustably reflect the first and second polarized emitted image lights 21, 31 as respective first transmitted and second reflected polarized image lights 24, 34. Specifically, the adjustable polarizing reflector 10 is configured to receive the first polarized emitted image light 21 and adjustably transmit the first polarized emitted image light 21 as the first transmitted polarized image light 24. Similarly, the adjustable polarizing reflector 10 is configured to receive the second polarized emitted image light 31 and adjustably reflect the second polarized emitted image light 31 as the second reflected polarized image light 34.

[0050] In the embodiments, the HUD 300 is configured to form the respective first and second polarized displayed images 23, 33 of the first and second polarized emitted images 22, 32 for viewing by one or more viewers (e.g., the driver 320 and / or the passenger 325 as shown in FIG. 1A) after the first and second polarized emitted images 22, 32 are respectively transmitted and reflected by the adjustable polarizing reflector 10.

[0051] In some embodiments, the optical mirror 40 is disposed on the windshield 50 of the vehicle 310 shown in FIG. 1 A. In some embodiments, the windshield 50 includes the optical mirror 40.

[0052] The optical mirror 40 is configured to receive and reflect at least 10% of the first transmitted and second reflected polarized image lights 24, 34 toward the eye 315 of the same first occupant (e.g., the driver 320 or the passenger 325 as shown in FIG. 1 A). In some embodiments, the optical mirror 40 is configured to receive and reflect at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, or at least 95% of the first transmitted and second reflected polarized image lights 24, 34 toward the eye 315 of the same first occupant.

[0053] In some embodiments, the optical mirror 40 is configured to receive the first transmitted and second reflected polarized image lights 24, 34 and reflect at least portions 25, 35 of the first transmitted and second reflected polarized image lights 24, 34. Specifically, the optical mirror 40 is configured to receive the first transmitted polarized image light 24 and reflect at least the portion 25 of the first transmitted polarized image light 24 toward the eye 315 of the same first occupant. Similarly, the optical mirror 40 is configured to receive the second reflected polarized image light 34 and reflect at least the portion 35 of the second reflected polarized image light 34 toward the eye 315 of the same first occupant.

[0054] In some embodiments, the optical mirror 40 is at least a partially opaque optical mirror, and hence, may be interchangeably referred to as “the opaque optical mirror 40”. In some embodiments, the opaque optical mirror 40 includes a reflector 41 and an absorber 42. In some embodiments, the reflector 41 is disposed on the absorber 42. In some embodiments, the reflector 41 is disposed between the absorber 42, and the first and second displays 20, 30.

[0055] In some embodiments, for a substantially normally incident light, each of the first and second polarization states, and each of at least one blue wavelength in the blue wavelength range, at least one green wavelength in the green wavelength range, and at least one red wavelength in the red wavelength range, the reflector 41 reflects at least 10% of the incident light and the absorber 42 absorbs at least 40% of the incident light.

[0056] In some embodiments, for the substantially normally incident light, each of the first and second polarization states, and each of the at least one blue wavelength, the at least one green wavelength, and the at least one red wavelength, the reflector 41 reflects at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, or at least 95% of the incident light and the absorber 42 absorbs at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, or at least 95% of the incident light.

[0057] In some embodiments, the opaque optical mirror 40 has an optical transmittance of less than about 30% for the at least one same first visible wavelength. In some embodiments, the opaque optical mirror 40 has the optical transmittance of less than about 25%, less than about 20%, less than about 15%, less than about 10%, less than about 8%, less than about 6%, less than about 4%, less than about 2%, less than about 1%, less than about 0.5%, or less than about 0.1% for the at least one same first visible wavelength.

[0058] In some embodiments, at least one of the first and second displays 20, 30 is coupled to a positioner 100, 101 configured to change at least one or more of an axial position, a lateral position, a tilt, and an orientation of the display relative to the optical mirror 40. In the illustrated embodiment of FIG. 2, the first display 20 is coupled to the positioner 100 to adjust the first display 20 relative to the optical mirror 40, and the second display 30 is coupled to the positioner 101 to adjust the second display 30 relative to the optical mirror 40.

[0059] In some embodiments, the first and second displays 20, 30 are so positioned and oriented, and the first and second polarized emitted images 22, 32 having intensities and contents, so as to generate a depth perception of the first and second polarized displayed images 23, 33 by the first occupant.

[0060] In some embodiments, the first and second displays 20, 30 are so positioned and oriented, the first and second polarized emitted images 22, 32 having intensities and contents, and the first and second polarized displayed images 23, 33 are so spaced from each other, so as to generate a perception of a three-dimensional single image by the first occupant.

[0061] In some embodiments, the vehicle 310 (shown in FIG. 1A) includes a dashboard 80. The dashboard 80 includes a top portion 81 and a dashboard opening 82. The top portion 81 faces the optical mirror 40 and defines the dashboard opening 82. In some embodiments, the first and second displays 20, 30 are at least partially disposed inside the dashboard 80 of the vehicle 310. In addition, in some embodiments, the optical mirror 40 is at least partially disposed outside the dashboard 80.

[0062] In some embodiments, the first transmitted and the second reflected polarized image lights 24, 34 exit the dashboard 80 through the dashboard opening 82 before being received and reflected by the optical mirror 40.

[0063] Therefore, the first and second displays 20, 30 may be shielded from direct view by one or more occupants (i.e., the driver 320 and / or the passenger 325), such that only the first and second polarized displayed images 23, 33 may be seen by the one or more occupants.

[0064] In some embodiments, the dashboard 80 may be a part of the HUD 300 and may be referred to as “the housing 80” of the HUD 300. In such cases, the top portion 81 of the dashboard 80 may be interchangeably referred to as “the top side 81”, and the dashboard opening 82 may be interchangeably referred to as “the opening 82”. In some embodiments, the housing 80 has the top side 81 defining the opening 82.

[0065] In the embodiments, the adjustable polarizing reflector 10 is at least partially disposed inside the housing 80. In some embodiments, the first and second displays 20, 30 are at least partially disposed inside the housing 80.

[0066] FIG. 3 is a schematic view of a HUD 300a, according to another embodiment of the present disclosure. The HUD 300a is substantially similar to the HUD 300 illustrated in FIG. 2, with like elements designated by like reference characters.

[0067] However, the HUD 300a additionally includes a first magnifying mirror 90 for magnifying the second polarized emitted image light 31 and reflecting the second polarized emitted image light 31 as a reflected second magnified polarized emitted image light 38.

[0068] The optical mirror 40 is configured to receive and reflect the second polarized emitted image light 31 after the second polarized emitted image light 31 is received and reflected by the first magnifying mirror 90.

[0069] As shown in FIG. 3, the optical mirror 40 is configured to receive a second reflected magnified polarized emitted image light 34’ after the second polarized emitted image light 31 is received and reflected by the first magnifying mirror 90 and reflect at least a portion 35’ of the second reflected magnified polarized emitted image light 34’. Specifically, the illustrated embodiment of FIG. 3, the optical mirror 40 is configured to receive the second reflected magnified polarized emitted image light 34’ after the reflected second magnified polarized emitted image light 38 is received and reflected by the adjustable polarizing reflector 10 and reflect at least the portion 35’ of the second reflected magnified polarized emitted image light 34’ towards the eye 315.

[0070] In some embodiments, at least one of the first and second polarized displayed images 23, 33 is a virtual image. In the illustrated embodiment of FIG. 3, the first polarized display image 23 is a first real polarized image and the second polarized display image 33 is a second virtual polarized image 33 a. In some embodiments, a maximum lateral dimension of the second virtual polarized image 33a is greater than a maximum lateral dimension of the first real polarized image 23 by at least a factor of 2. In some embodiments, the maximum lateral dimension of the second virtual polarized image 33a is greater than the maximum lateral dimension of the first real polarized image 23 by at least a factor of 5, at least a factor of 10, at least a factor of 20, at least a factor of 30, at least a factor of 40, at least a factor of 50, at least a factor of 100, at least a factor of 500, or at least a factor of 1000.

[0071] FIG. 4 is a schematic view of a HUD 300b, according to another embodiment of the present disclosure. The HUD 300b is substantially similar to the HUD 300a as illustrated in FIG. 3, with like elements designated by like reference characters. However, the HUD 300b includes a second display 30’. The second display 30’ is substantially similar to the second display 30 shown in FIG. 3, however, the second display 30’ has a different position in the HUD 300b.

[0072] As shown in FIG. 4, in some embodiments, the first and second displays 20, 30’ are disposed on a same major side of the adjustable polarizing reflector 10. In the illustrated embodiment of FIG. 4, the first and second displays 20, 30’ are disposed on the first major side 11 of the adjustable polarizing reflector 10.

[0073] FIG. 5 is a schematic diagram showing a relative placement of the first and second displays 20, 30 of the HUD 300 shown in FIG. 2, according to an embodiment of the present disclosure.

[0074] As shown in FIG. 5, the first and second displays 20, 30 include respective first and second display surfaces 26, 36. Specifically, the first display 20 includes the first display surface 26 and the second display 30 includes the second display surface 36. In some embodiments, the first and second display surfaces 26, 36 make an oblique angle al therebetween.

[0075] In some embodiments, the first and second polarized emitted images 22, 32 (shown in FIG. 2) are formed and displayed on the respective first and second display surfaces 26, 36 of the respective first and second displays 20, 30. Specifically, the first polarized emitted image 22 is formed and displayed on the first display surface 26 of the first display 20 and the second polarized emitted image 32 is formed and displayed on the second display surface 36 of the second display 30.

[0076] FIGS. 6A-6C are schematic views of different positionings of the first and second polarized displayed images 23, 33, according to an embodiment of the present disclosure.

[0077] As shown in FIGS. 6A and 6B, in some embodiments, the first and second polarized displayed images 23, 33 are not co-planar.

[0078] Further, as shown in FIG. 6A, the first and second polarized displayed images 23, 33 include respective first and second polarized displayed images 23’, 33’. In some embodiments, the first and second polarized displayed images 23’, 33’ make an oblique angle a2 with each other.

[0079] In some embodiments, the first and second polarized displayed images 23’, 33’ make the oblique angle a2 of less than about 80 degrees with each other. In some embodiments, the first and second polarized displayed images 23’, 33’ make the oblique angle a2 of less than about 70 degrees, less than about 60 degrees, less than about 50 degrees, less than about 40 degrees, less than about 30 degrees, less than about 20 degrees, or less than about 10 degrees with each other. As shown in FIG. 6B, the first and second polarized displayed images 23, 33 include respective first and second polarized displayed images 23”, 33”. In some embodiments, the first and second polarized displayed images 23 ”, 33 ” are substantially parallel with each other.

[0080] As shown in FIG. 6C, the first and second polarized displayed images 23, 33 include respective first and second polarized displayed images 23”’, 33 ” ’. In some embodiments, the first and second polarized displayed images 23 ’”, 33 ’” are substantially co-planar. In some embodiments, the first and second polarized displayed images 23’”, 33’” at least partially overlap one another.

[0081] Referring to FIGS. 6A-6C, the different positionings of the first and second polarized emitted images 22, 32 may generate a depth perception of the first and second polarized displayed images 23, 33 and / or a perception of a three-dimensional single real image, as per desired application attributes.

[0082] Therefore, the HUD 300 may provide a more immersive information environment and differentiation between information displayed on the first and second polarized displayed images 23, 33. This may provide a unique experience in terms of how the occupants (i.e., the driver 320 and / or the passenger 325) may receive and interact with the information.

[0083] FIG. 7 is a schematic top view of a display, according to an embodiment of the present disclosure.

[0084] The display may be the first display 20 or the second display 30. The first and second displays 20, 30 may have a corresponding maximum lateral dimension dl. In some embodiments, at least one of the first and second displays 20, 30 has the maximum lateral dimension dl of at least 15 centimeters (cm). In some embodiments, at least one of the first and second displays 20, 30 has the maximum lateral dimension dl of at least 20 cm, at least 25 cm, at least 30 cm, at least 35 cm, at least 40 cm, or at least 50 cm.

[0085] In some embodiments, the first and second displays 20, 30 have substantially a same size. However, in some other embodiments, the first and second displays 20, 30 have different sizes. In some embodiments, the second display 30 is smaller than the first display 20 by at least 10%. In some embodiments, the second display 30 is smaller than the first display 20 by at least 20%, at least 30%, at least 40%, or at least 50%.

[0086] In some embodiments, sizes of the first and second polarized displayed images 23, 33 (as shown in FIG. 2) are substantially equal to sizes of the respective first and second displays 20, 30. In other words, the size of the first polarized displayed image 23 is substantially equal to the size of the first display 20 and the size of the second polarized displayed image 33 is substantially equal to the size of the second display 30.

[0087] In some embodiments, a lateral dimension of the second virtual polarized image 33a (as shown in FIG. 3) is greater than a corresponding lateral dimension of the second display 30 by at least a factor of 10. In some embodiments, the lateral dimension of the second virtual polarized image 33a is greater than the corresponding lateral dimension of the second display 30 by at least a factor of 50, at least a factor of 100, at least a factor of 500, or at least a factor of 1000. In some embodiments, the first and second displays 20, 30 have substantially a same shape. However, in some other embodiments, the first and second displays 20, 30 have different shapes.

[0088] FIG. 8 is a schematic view of the adjustable polarizing reflector 10 of the HUD 300, 300a, 300b, according to an embodiment of the present disclosure.

[0089] In some embodiments, the adjustable polarizing reflector 10 includes an adjustable polarization rotator 130, a first reflective polarizer 140, and a second reflective polarizer 141. In some embodiments, the adjustable polarization rotator 130 is disposed between the first and second reflective polarizers 140, 141.

[0090] As shown in FIG. 8, the adjustable polarizing reflector 10 is configured to receive and adjustably transmit Tl% and adjustably reflect R2% of the respective first and second polarized emitted image lights 21, 31 as the respective first transmitted and second reflected polarized image lights 24, 34. Specifically, the adjustable polarizing reflector 10 is configured to receive the first polarized emitted image light 21 and adjustably transmit Tl% of the first polarized emitted image light 21 as the first transmitted polarized image lights 24. Similarly, the adjustable polarizing reflector 10 is configured to receive the second polarized emitted image light 31 and adjustably reflect R2% of the second polarized emitted image light 31 as the second reflected polarized image light 34.

[0091] A sum of R2 and T1 is greater than or equal to about 30 and less than or equal to about 100, i.e., 30 < R2+T1 < 100. In some embodiments, 40 < R2+T1 < 100, 50 < R2+T1 < 100, 60 < R2+T1 < 100, 70 < R2+T1 < 100, 80 < R2+T1 < 100, 80 < R2+T1 < 95, 90 < R2+T1 < 100, or 90 < R2+T1 < 98.

[0092] In some embodiments, the adjustable polarizing reflector 10 is configured to receive and adjustably reflect Rl% and adjustably transmit T2% of the first and second polarized emitted image lights 21, 31 as respective first reflected and second transmitted polarized image lights 27, 37. Specifically, the adjustable polarizing reflector 10 is configured to receive and adjustably reflect Rl% of the first polarized emitted image light 21 as the first reflected polarized image light 27 and the adjustable polarizing reflector 10 is configured to receive and adjustably transmit T2% of the second polarized emitted image light 31 as the second transmitted polarized image light 37.

[0093] In some embodiments, a sum of R1 and T2 is greater than or equal to about 30 and less than or equal to about 100, i.e., 30 < R1+T2 < 100. In some embodiments, 40 < R1+T2 < 100, 50 < R1+T2 < 100, 60 < R1+T2 < 100, 70 < R1+T2 < 100, 80 < R1+T2 < 100, 80 < R1+T2 < 95, 90 < R1+T2 < 100, or 90 < R1+T2 < 98.

[0094] In some embodiments, the adjustable reflectance of the adjustable polarizing reflector 10 can be continuously adjusted at least between about 30% and about 70%. In some embodiments, the adjustable reflectance of the adjustable polarizing reflector 10 can be continuously adjusted at least between about 20% and about 80%, at least between about 15% and about 85%, at least between about 10% and about 90%, at least between about 5% and about 95%, at least between about 2% and about 98%, or at least between about 1% and about 99%.

[0095] In some embodiments, the adjustable transmittance of the adjustable polarizing reflector 10 can be continuously adjusted at least between about 30% and about 70%. In some embodiments, the adjustable transmittance of the adjustable polarizing reflector 10 can be continuously adjusted at least between about 20% and about 80%, at least between about 15% and about 85%, at least between about 10% and about 90%, at least between about 5% and about 95%, at least between about 2% and about 98%, or at least between about 1% and about 99%.

[0096] FIGS. 9A-9B are schematic sectional views of the adjustable polarizing reflector 10 of the HUD 300, according to an embodiment of the present disclosure.

[0097] The adjustable polarizing reflector 10 defines mutually orthogonal x, y, and z-axes. The x and y-axes are in-plane axes of the adjustable polarizing reflector 10, while the z-axis is a transverse axis disposed along a thickness of the adjustable polarizing reflector 10. In other words, the x and y-axes are disposed along a plane of the adjustable polarizing reflector 10, while the z-axis is perpendicular to the plane of the adjustable polarizing reflector 10. As discussed in FIG. 8, the adjustable polarizing reflector 10 includes the adjustable polarization rotator 130 disposed between the first and second reflective polarizers 140, 141.

[0098] In some embodiments, the adjustable polarization rotator 130 includes a liquid crystal (LC) composition having an orientation that is adjustable by an applied signal VI. In some embodiments, the applied signal VI is an electrical signal. In some embodiments, the applied signal VI is a voltage signal.

[0099] In some embodiments, the adjustable polarization rotator 130 is configured to rotate a polarization of an incident light by a substantially continuously adjustable number of degrees across a continuous range extending from about zero degree up to at least 30 degrees for each of the mutually orthogonal first and second polarization states and for the at least one same first visible wavelength in the visible wavelength range extending from about 420 nm to about 680 nm.

[0100] In some embodiments, the adjustable polarization rotator 130 is configured to rotate the polarization of the incident light by the substantially continuously adjustable number of degrees across the continuous range extending from about zero degree up to at least 40 degrees, at least 50 degrees, at least 60 degrees, at least 70 degrees, at least 80 degrees, or at least 90 degrees for each of the first and second polarization states and for the at least one same first visible wavelength in the visible wavelength range. As discussed above, in some embodiments, the first polarization state may correspond to the s- polarization state, and the second polarization state may correspond to the p-polarization state.

[0101] In some embodiments, for a substantially normally incident polarized light 71 having the at least one same first visible wavelength, the adjustable polarization rotator 130 is configured to rotate the polarization of the incident light 71 by an adjustable number of degrees. In some embodiments, the adjustable number of degrees can be adjusted continuously by at least up to about 30 degrees. In some embodiments, the adjustable number of degrees can be adjusted continuously by at least up to about 40 degrees, at least up to about 50 degrees, at least up to about 60 degrees, at least up to about 70 degrees, at least up to about 80 degrees, or at least up to about 90 degrees.

[0102] Further, as can be seen from FIG. 9A, in some embodiments, each of the first and second reflective polarizers 140, 141 has an in-plane pass-axis 140p, 141s and an in-plane orthogonal reflect- axis 140s, 14 Ip. Specifically, the first reflective polarizer 140 has the in-plane pass axis 140p and the in-plane orthogonal reflect-axis 140s. Similarly, the second reflective polarizer 141 has the in-plane pass axis 141s and the in-plane orthogonal reflect-axis 14 Ip.

[0103] In some embodiments, the pass-axes 140p, 141s of the first and second reflective polarizers 140, 141 are substantially orthogonal to one another. For instance, in the illustrated embodiment of FIG. 9A, the pass-axis 140p of the first reflective polarizer 140 is substantially orthogonal to the inplane pass-axis 141s of the second reflective polarizer 141. Similarly, in some embodiments, the inplane reflect axis 140s of the first reflective polarizer 140 is substantially orthogonal to the in-plane reflect axis 141p of the second reflective polarizer 141.

[0104] In the illustrated embodiment of FIG. 9 A, the pass-axis 140p is along the x-axis, while the reflect axis 140s is along the y-axis. Further, the pass-axis 141s is along the y-axis, while the reflect- axis 14 Ip is along the x-axis.

[0105] In some embodiments, for the substantially normally incident light 71 having the at least one same first visible wavelength, each of the first and second reflective polarizers 140, 141 transmits at least 40% of the incident light 71 polarized along the pass-axis 140p, 141s and reflects at least 40% of the incident light 71 polarized along the reflect-axis 140s, 141p. Specifically, in some embodiments, for the substantially normally incident light 71 having the at least one same first visible wavelength, the first reflective polarizer 140 transmits at least 40% of the incident light 71 polarized along the pass-axis 140p and reflects at least 40% of the incident light 71 polarized along the reflect-axis 140s. Further, in some embodiments, for the substantially normally incident light 71 having the at least one same first visible wavelength, the second reflective polarizer 141 transmits at least 40% of the incident light 71 polarized along the pass-axis 141s and reflects at least 40% of the incident light 71 polarized along the reflect-axis 14 Ip.

[0106] In some embodiments, for the substantially normally incident light 71, each of the first and second reflective polarizers 140, 141 transmits at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, or at least 95% of the incident light 71 polarized along the pass-axis 140p, 141s and reflects at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, or at least 95% of the incident light 71 polarized along the reflect-axis 140s, 14 Ip.

[0107] Referring to FIG. 9B, for a substantially normally incident light 150, 151, for each of the first and second polarization states, and for the at least the same first visible wavelength, the adjustable polarizing reflector 10 is configured to adjustably transmit T’% and adjustably reflect R’% of the incident light 150, 151. Specifically, as shown in FIG. 9B, for the substantially normally incident light 150, the adjustable polarizing reflector 10 is configured to adjustably transmit T’% of a transmitted light 150t having the second polarization state and adjustably reflect R’% of a reflected light 150r having the first polarization state. Similarly, for the substantially normally incident light 151, the adjustable polarizing reflector 10 is configured to adjustably transmit T’% of a transmit light 15 It having the first polarization state and adjustably reflect R’% of a reflected light 151 r having the second polarization state. In some embodiments, a sum of R’ and T’ is greater than or equal to about 30 and less than or equal to about 100, i.e., 30 < R’+T’ < 100. In some embodiments, 40 < R’+T’ < 100, 50 < R’+T’ < 100, 60 < R’+T’ < 100, 70 < R’+T’ < 100, 80 < R’+T’ < 100, 80 < R’+T’ < 95, 90 < R’+T’ < 100, or 90 < R’+T’ < 98.

[0108] In some embodiments, the adjustable polarization rotator 130 is configured to continuously adjust R’% and T’% of the incident lights 150, 151. In other words, in some embodiments, the adjustable polarization rotator 130 is configured to continuously tune a ratio of R’% and T’% of the incident lights 150, 151.

[0109] FIG. 10 is a schematic detailed sectional view of a reflective polarizer of the HUD 300, according to an embodiment of the present disclosure. The reflective polarizer may be the first reflective polarizer 140 or the second reflective polarizer 141. FIG. 10 also shows the substantially normally incident light 71 incident on the first and / or second reflective polarizer 140, 141 of the adjustable polarizing reflector 10 (shown in FIG. 9A).

[0110] In some embodiments, each of the first and second reflective polarizers 140, 141 includes a plurality of polymeric layers 14, 15. In some embodiments, the plurality of polymeric layers 14, 15 includes a plurality of alternating polymeric first and polymeric second layers 14, 15. In some embodiments, the polymeric first layers 14 have a different composition than the polymeric second layers 15.

[0111] In some embodiments, the plurality of polymeric layers 14, 15 numbers at least 10 in total. In some embodiments, the plurality of polymeric layers 14, 15 numbers at least 20, at least 50, at least 75, at least 100, at least 150, at least 200, at least 250, or at least 300 in total.

[0112] In some embodiments, each of the polymeric layers 14, 15 has an average thickness t of less than about 500 nm. The term “the average thickness t”, as used herein, refers to an average of thicknesses measured at multiple points across a plane (i.e., the x-y plane) of each of the plurality of polymeric layers 14, 15. In some embodiments, each of the polymeric layers 14, 15 has the average thickness t of less than about 400 nm, less than about 300 nm, or less than about 200 nm.

[0113] In some embodiments, each of the first and second reflective polarizers 140, 141 further includes at least one skin layer 16 disposed on the plurality of polymeric layers 14, 15. The at least one skin layer 16 has an average thickness st of greater than about 500 nm. The term “the average thickness st”, as used herein, refers to an average of thicknesses measured at multiple points across a plane (i.e., the x-y plane) of each of the at least one skin layer 16. In some embodiments, the at least one skin layer 16 has the average thickness st of greater than about 750 nm, greater than about 1000 nm, greater than about 1500 nm, or greater than about 2000 nm.

[0114] In the illustrated embodiment of FIG. 10, the at least one skin layer 16 includes a pair of skin layers 16, and the plurality of polymeric layers 14, 15 is disposed between the pair of skin layers 16. The at least one skin layer 16 may protect the plurality of polymeric layers 14, 15 and may also provide mechanical stability to each of the first and second reflective polarizers 140, 141. In some cases, the at least one skin layer 16 may act as a protective boundary layer (PBL). FIG. 11 is a schematic diagram showing the first transmitted and second reflected polarized image lights 24, 34 from the adjustable polarizing reflector 10 of the HUD 300, 300a, 300b according to an embodiment of the present disclosure.

[0115] Referring to FIGS. 2-4 and 11, the first display 20 is configured to form and emit the first polarized emitted image 22, and the second display 30 is configured to form and emit the second polarized emitted image 32. As can be seen in FIG. 11, in some embodiments, the first and second displays 20, 30 are configured to emit temporally altematingly the respective first and second polarized emitted images 22, 32. In some embodiments, the first and second displays 20, 30 are configured to emit temporally altematingly the respective first and second polarized emitted images 22, 32 at a cycle rate, such that the one or more occupants perceive each of the first transmitted and second reflected polarized image lights 24, 34 and consequently each of the first and second polarized displayed images 23, 33 as a constant, flicker-free image. In some embodiments, the adjustable polarization reflector 10 is timed to alternate between the first polarization state to the second polarization state synchronously with the respective first display and second displays 20, 30 to achieve a temporal interleaving of the respective first and second polarized emitted images 22, 32. In some embodiments, the first and second polarized displayed images 23, 33 have a same polarization state at a high efficiency because the first and second polarized emitted image lights 21, 31 from the respective first display and second displays 20, 30 is substantially entirely reflected or transmitted by the adjustable polarizing reflector 10 with the same polarization state.

[0116] Referring to FIGS. 8, 9A-9B, and 11, in some embodiments, the adjustable polarization rotator 130 is configured to rotate the polarization of the first polarized emitted image 22 from the first polarization state to the second polarization state, for example, from the s-polarization state to the p- polarization state, and transmit the first transmitted polarized image light 24 therethrough. Further, the adjustable polarization rotator 130 is configured to receive the second polarized emitted image 32 and reflect the second polarized emitted image 32 having the second polarization state, for example the p- polarization state, as the second reflected polarized image light 34.

[0117] Referring to FIGS. 2-11, as the adjustable polarization rotator 130 of the adjustable polarizing reflector 10 is configured to rotate the polarization of the incident light by the substantially continuously adjustable number of degrees across the continuous range extending from about zero degree up to at least 30 degrees for each of the first and second polarization states and for the at least one same first visible wavelength in the visible wavelength range, the HUD 300, 300a, 300b may provide up to 100% efficiency for each of the two overlaid images (e.g., the first and second polarized displayed images 23, 33 shown in FIG. 2) with the same polarization state as shown in FIG. 11.

[0118] The HUDs 300, 300a, 300b may also provide a dynamic control over a transmission ratio of the first transmitted and second reflected polarized image lights 24, 34 as the adjustable polarization rotator 130 may enable a continuous tuning between the first and second polarization states for the first transmitted and second reflected polarized image lights 24, 34. Further, the HUD 300, 300a, 300b may provide the depth perception of the first and second polarized displayed images 23, 33 and / or the perception of the three-dimensional single real image by the one or more occupants. Thus, the HUD 300, 300a, 300b may provide a more immersive information environment and differentiation between information displayed on the first and second polarized displayed images 23, 33. This may provide a unique experience in terms of how the one or more occupants may receive and interact with the information.

[0119] 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.

[0120] 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 heads up display (HUD) for use in a vehicle, comprising: an adjustable polarizing reflector having adjustable reflectance and transmittance for each of mutually orthogonal first and second polarization states and for at least one same first visible wavelength in a visible wavelength range extending from about 420 mu to about 680 nm; different first and second displays configured to form and emit respective first and second polarized emitted image lights toward the adjustable polarizing reflector, the first and second polarized emitted image lights having substantially the respective first and second polarization states and comprising respective first and second polarized emitted images, the HUD configured to form respective first and second polarized displayed images of the first and second polarized emitted images for viewing by an eye of a same first occupant of the vehicle, the adjustable polarizing reflector configured to receive and adjustably transmit Tl% and adjustably reflect R2% of the first and second polarized emitted image lights as respective first transmitted and second reflected polarized image lights, 30 < R2+T1 < 100; and an optical mirror configured to receive and reflect at least 10% of the first transmitted and second reflected polarized image lights toward the eye of the same first occupant.

2. The HUD of claim 1, wherein the first and second displays are disposed on opposite respective first and second major sides of the adjustable polarizing reflector.

3. The HUD of claim 1, wherein at least one of the first and second polarized displayed images is a virtual polarized image.

4. The HUD of claim 1, wherein the first polarized display image is a first real polarized image and the second polarized display image is a second virtual polarized image.

5. The HUD of claim 1, wherein the first and second displays are so positioned and oriented, and the first and second polarized emitted images having intensities and contents, so as to generate a depth perception of the first and second polarized displayed images by the first occupant.

6. The HUD of claim 1, wherein the adjustable polarizing reflector is closer to one of the first and second displays and farther from the other one of the first and second displays.

7. The HUD of claim 1, wherein the first and second polarized displayed images are substantially co-planar, and wherein the first and second polarized displayed images at least partially overlap one another.

8. The HUD of claim 1, wherein the optical mirror is at least a partially opaque optical mirror having an optical transmittance of less than about 30% for the at least one same first visible wavelength.

9. The HUD of claim 8, wherein the opaque optical mirror comprises a reflector disposed on an absorber, such that for a substantially normally incident light, each of the first and second polarization states, and each of at least one blue wavelength in a blue wavelength range extending from about 420 nm to about 480 nm, at least one green wavelength in a green wavelength range extending from about 490 nm to about 560 nm, and at least one red wavelength in a red wavelength range extending from about 590 nm to about 670 nm, the reflector reflects at least 10% of the incident light and the absorber absorbs at least 40% of the incident light.

10. A heads up display (HUD) for use in a vehicle, comprising: a housing having a top side defining an opening; an adjustable polarizing reflector at least partially disposed inside the housing and comprising an adjustable polarization rotator disposed between first and second reflective polarizers, the adjustable polarization rotator configured to rotate a polarization of an incident light by a substantially continuously adjustable number of degrees across a continuous range extending from about zero degree up to at least 30 degrees for each of mutually orthogonal first and second polarization states and for at least one same first visible wavelength in a visible wavelength range extending from about 420 nm to about 680 nm; and first and second displays at least partially disposed inside the housing and configured to form and emit respective first and second polarized emitted images, the HUD configured to form respective first and second polarized displayed images of the first and second polarized emitted images for viewing by one or more viewers after the first and second polarized emitted images are respectively transmitted and reflected by the adjustable polarizing reflector.

Images