MULTIPLEXED, FLOATING AUTOSTEREOSCOPEC 3D DISPLAY

Abstract

A multiview campfire display comprises a light source configured to emit a beam of light and a spatial light modulator (SLM) positioned to receive the beam emitted by the light source. The holographic display also includes a user tracker configured to track the head and eyes of vehicle occupants. The display also includes a control unit that communicates with the user tracker, the light source, and the SLM. The control unit is programmed to receive the eye-tracking signal from the user tracker and to control a polarizing optic of the light beam emitted by the light source and modulated by the SLM. This optic redirects the image encoded by the SLM to the multitude of vehicle occupants based on the eye-tracking signal, thus enabling each of the vehicle occupants to see the image.

Description

INTRODUCTION

[0001] The present disclosure relates to displays, and more particularly to multiplexed floating autostereoscopic displays.

[0002] This introduction generally presents the context of the disclosure. Works by the presently named inventors, to the extent described in this introduction, as well as aspects of the description that may not otherwise be considered prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against this disclosure.

[0003] In vehicles with campfire seats, it is desirable to display a hologram that is visible to all passengers. In this case, the display should be capable of displaying the hologram for multiple passenger seats with minimal hardware. SUMMARY

[0004] The present disclosure describes multiplexed, floating autostereoscopic displays. According to one aspect of the present disclosure, the multiview campfire display includes a light source configured to emit a light beam and a spatial light modulator (SLM) positioned to receive the light beam emitted by the light source. The SLM is configured to encode an image. The holographic display also includes a user tracker (e.g., eye tracker) configured to track the head and eyes of vehicle occupants. The user tracker is configured to generate an eye tracking signal. The eye tracking signal is an indicator of a position of the eyes of each of the plurality of vehicle occupants. The display also includes a controller in communication with the user tracker, the light source, and the SLM.The controller is programmed to: receive the eye-tracking signal from the user tracker; and control a polarizing optic of the light beam emitted by the light source and modulated by the SLM to redirect the SLM-encoded image to the plurality of vehicle occupants based on the eye-tracking signal, thereby allowing each of the plurality of vehicle occupants to view the image. The image is redirected to multiple users using one of the three techniques described below (e.g., SLM grating, digital micromirror device (DMD), or liquid crystal (LC) polarization rotator). The SLM and the redirection device (e.g., SLM grating, digital micromirror device (DMD), or liquid crystal (LC) polarization rotator) are synchronized to send the same or different images to multiple vehicle occupants. This is a temporal sequencing of images.

[0005] In another aspect of the present disclosure, the user tracker includes at least one camera. The display may include a plurality of reflectors and a plurality of movable mounts, each coupled to one of the plurality of reflectors to allow each of the plurality of reflectors to move. The controller is in communication with the plurality of movable mounts. The controller is programmed to instruct each of the plurality of movable mounts to align the image with the eyes of each of the plurality of vehicle occupants. Each of the plurality of reflectors may be a galvanized metal mirror. Each of the plurality of movable mounts may be a gimbal. The controller is programmed to control the light source and the SLM to use a holographic grating to redirect the image encoded by the SLM.

[0006] In another aspect of the present disclosure, the multiview campfire display may include a digital micromirror device (DMD) positioned to receive the image encoded by the SLM. The DMD is configured to redirect the image encoded by the SLM for the plurality of vehicle occupants. The DMD is in communication with the controller. The controller is programmed to control the DMD to redirect the image encoded by the SLM for the plurality of vehicle occupants based on the eye-tracking signal, thereby allowing each of the plurality of vehicle occupants to view the image.

[0007] In another aspect of the present disclosure, the display includes a tunable liquid crystal (LC) polarization rotator positioned to receive the image encoded by the SLM. The controller is programmed to control the tunable LC polarization rotator to redirect the image encoded by the SLM for the plurality of vehicle occupants based on the eye tracking signal, thereby allowing each of the plurality of vehicle occupants to view the image. The tunable LC polarization rotator is positioned to receive the image encoded by the SLM. The controller is programmed to control the tunable LC polarization rotator to redirect the image encoded by the SLM for the plurality of vehicle occupants based on the eye tracking signal, thereby allowing each of the plurality of vehicle occupants to view the image.The multiview campfire display may include a polarized beam splitter (PBS) downstream of the tunable LC polarization rotator, and the PBS is configured to redirect the image encoded by the SLM.

[0008] Another aspect of the present disclosure is that a vehicle includes a vehicle body. The vehicle body defines a passenger compartment. The vehicle further includes the above-described multiview campfire display in the passenger compartment.

[0009] The present disclosure also describes a method for displaying a hologram. The method includes activating a light source to emit a light beam; modulating the light beam using a spatial light modulator (SLM) to encode an image; and controlling polarizing optics of the light beam to redirect the image encoded by the SLM to a plurality of vehicle occupants, thereby allowing each of the plurality of vehicle occupants to view the image.

[0010] Further areas of applicability of the present disclosure will become apparent from the detailed description provided below. It should be understood that the detailed description and specific examples are for purposes of illustration only and are not intended to limit the scope of the disclosure.

[0011] The foregoing features and advantages, as well as other features and advantages of the presently disclosed system and method, are readily apparent from the detailed description, including the claims and exemplary embodiments, taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The present disclosure will be more fully understood from the detailed description and the accompanying drawings, in which: Fig. Figure 1 is a block diagram showing a vehicle incorporating a display; Fig. 2 is a schematic isometric side view of a passenger compartment of the vehicle of Fig. 1 is; Fig. 3 is a schematic isometric side view of a passenger compartment of the vehicle of Fig. 1, which shows a three-dimensional (3D) hologram; Fig. Figure 4 is a schematic diagram of a holographic display with holographic gratings; Fig. Figure 5 is a schematic diagram of a holographic display with a digital micromirror device; Fig. Figure 6 is a schematic diagram of a holographic display with a tunable LC polarization rotator; and Fig. 7 is a flowchart for a method of displaying a hologram. DETAILED DESCRIPTION

[0013] Reference will now be made in detail to several examples of the disclosure, which are illustrated in the accompanying drawings. Wherever possible, like or similar reference characters are used throughout the drawings and the description to refer to like or similar parts or steps.

[0014] With reference to Fig. 1, a vehicle 10 generally includes a chassis 12, a body 14, front and rear wheels 17, and may be referred to as a vehicle system. In the illustrated embodiment, the vehicle 10 includes two front wheels 17a and two rear wheels 17b. The body 14 is disposed on the chassis 12 and substantially encloses the components of the vehicle 10. The body 14 and the chassis 12 may together form a frame. The wheels 17 are each rotatably coupled to the chassis 12 near a corner of the body 14. The vehicle 10 includes a front axle 19 coupled to the front wheels 17a and a rear axle 25 coupled to the rear wheels 17b.

[0015] In various embodiments, the vehicle 10 may be an autonomous vehicle, and a control system 98 is integrated into the vehicle 10. The control system 98 may be referred to as the system or the system for user interaction with one or more holographic displays 29. The vehicle 10 is, for example, a vehicle that is automatically controlled to transport passengers from one location to another. The vehicle 10 may be embodied as a truck, sedan, coupe, sport utility vehicle (SUV), recreational vehicle (RV), etc. In one embodiment, the vehicle 10 may be a so-called level two, level three, level four, or level five automation system.A Level 4 system indicates a "high degree of automation" and refers to the driving mode-specific execution of aspects of the dynamic driving task by an automated driving system, even if a human driver does not respond appropriately to a request for intervention. A Level 5 system indicates "full automation," which refers to the automated driving system fully executing all aspects of the dynamic driving task under a range of road and environmental conditions that can be handled by a human driver. In Level 3 vehicles, the vehicle systems perform the entire dynamic driving task (DDT) within the range for which they were designed.The vehicle operator is only expected to be responsible for the DDT recall if the vehicle 10 is essentially "requesting" the driver to take over operation if something is not working correctly or the vehicle is about to leave the range in which it can operate. On Level 2 vehicles, the systems assist steering, braking / acceleration, lane centering, and adaptive cruise control. But even with these systems activated, the driver must remain behind the wheel and constantly monitor the automatic features.

[0016] As illustrated, the vehicle 10 generally includes a propulsion system 20, a transmission system 22, a steering system 24, a braking system 26, a sensor system 28, an actuator system 30, at least one data storage device 32, at least one controller 34, and a communication system 36. The propulsion system 20, in various embodiments, may include an electric machine, such as a traction motor and / or a fuel cell propulsion system. The vehicle 10 may further include a battery (or battery pack) 21 electrically connected to the propulsion system 20. Accordingly, the battery 21 is configured to store electrical energy and provide electrical energy to the propulsion system 20. In certain embodiments, the propulsion system 20 may include an internal combustion engine. The transmission system 22 is configured to transfer power from the propulsion system 20 to the wheels 17 according to selectable gear ratios.According to various embodiments, the transmission system 22 may include a stepped-ratio automatic transmission, a continuously variable transmission, or other suitable transmission. The braking system 26 is configured to provide braking torque to the vehicle wheels 17. The braking system 26 may, in various embodiments, include friction brakes, wire-based brakes, a regenerative braking system such as an electric machine, and / or other suitable braking systems. The steering system 24 influences a position of the vehicle wheels 17 and may include a steering wheel 33. Although shown as including a steering wheel 33 for illustrative purposes, the steering system 24 may not include a steering wheel 33 in some embodiments contemplated within the scope of the present disclosure.

[0017] The sensor system 28 includes one or more sensors 40 (i.e., measuring devices) that sense observable conditions of the external environment and / or the internal environment of the vehicle 10. The sensors 40 are in communication with the controller 34 and may include, but are not limited to, one or more radars, one or more Lidar (Light Detection and Ranging) sensors, one or more proximity sensors, one or more odometers, one or more GPR (Ground Penetrating Radar) sensors, one or more steering angle sensors, global navigation satellite system (GNSS) transceivers (e.g.,one or more global positioning system (GPS) transceivers, one or more tire pressure sensors, one or more cameras 31, one or more gyroscopes, one or more accelerometers, one or more inclinometers, one or more speed sensors, one or more three-dimensional (3D) depth sensors 45, one or more ultrasonic sensors, one or more inertial measurement units (IMUs), thermal imaging sensors, one or more microphones 31, and / or other sensors. Each sensor 40 is configured to generate a signal indicative of the sensed observable conditions (i.e., sensor data) of the external environment and / or the internal environment of the vehicle 10. Because the sensor system 28 provides sensor data to the controller 34, the sensor system 28 and its sensors 40 are considered sources of information (or simply sources).

[0018] The 3D depth sensors 45 are configured to capture multi-point distance information across a field of view (FoV) and measure the distance from the 3D depth sensors 45 to an object, such as a hand 15, within the FoV of the 3D depth sensor 45. Therefore, the 3D depth sensors 45 can output a matrix of multiple distance measurements across the FoV to obtain an accurate image with full 3D depth perception. The 3D depth sensors 45 can be, for example, time-of-flight sensors and stereo depth cameras. Stereo depth cameras can use the principle of time-of-flight and infrared light to determine the depth of a scene and create a 3D model, spatially mapping the interior of the passenger compartment 54 in space, as well as the position of the body 13 of the vehicle occupant 11 and the position of the hand 15 of the vehicle occupant 11. The body 14 of the vehicle 10 defines the passenger compartment 54.

[0019] The actuator system 30 includes one or more actuator devices 42 that control one or more vehicle functions, such as, but not limited to, the drive system 20, the transmission system 22, the steering system 24, and the braking system 26. In various embodiments, the vehicle features may further include interior and / or exterior features of the vehicle, such as doors, a trunk, and interior features such as air, music, and lighting, etc.

[0020] One or more of the actuator devices 42 are configured as a haptic actuator 47. The haptic actuator 47 is configured to provide haptic feedback to the vehicle user 11. In other words, the haptic actuator 47 is configured to create a tactile experience by applying forces, vibrations, or movements to the vehicle user 11 within the passenger compartment 54. The haptic actuator 47 may be, for example, a piezoelectric actuator, an eccentric rotating mass (ERM) actuator, a linear resonant actuator (LRA), ultrasonic actuators, and / or a non-contact haptic actuator, such as air swirl ring actuators. The air swirl ring actuator may provide an air pulse to the vehicle user 11.The haptic actuator 47 is in communication with the control unit 34, and the control unit 34 is programmed to control the operation of the haptic actuator 47.

[0021] The data storage device 32 stores data used in automatically controlling the vehicle 10. In various embodiments, the data storage device 32 stores defined maps of the navigable environment. In various embodiments, the defined maps may be predefined and obtained from a remote system. For example, the defined maps may be compiled by the remote system and transmitted to the vehicle 10 (wirelessly and / or wired), and stored in the data storage device 32. The data storage device 32 may be part of the controller 34, redirected from the controller 34, or part of the controller 34 and part of a redirection system.

[0022] The vehicle 10 may further include one or more airbags 35 in communication with the controller 34 or another controller of the vehicle 10. The airbag 35 includes an inflatable bladder and is configured to transition between a stowed and a deployed configuration to cushion the effects of an external force applied to the vehicle 10. The sensors 40 may include an airbag sensor, such as an IMU, configured to detect an external force and generate a signal indicative of the magnitude of that external force. The controller 34 is configured to command deployment of the airbag 35 based on the signal from one or more sensors 40, such as the airbag sensor. Accordingly, the controller 34 is configured to determine when the airbag 35 has deployed.

[0023] The controller 34 includes at least one processor 44 and a non-transitory storage device or media 46. The processor 44 may be any custom or off-the-shelf processor, a central processing unit (CPU), a graphics processing unit (GPU), an auxiliary processor among multiple processors associated with the controller 34, a semiconductor-based microprocessor (in the form of a microchip or chipset), a macroprocessor, a combination thereof, or generally a device for executing instructions. The computer-readable storage device or media 46 may include volatile and non-volatile memory, such as read-only memory (ROM), random access memory (RAM), and keep-alive memory (KAM). KAM is persistent or non-volatile memory that can be used to store various operating variables while the processor 44 is powered off.The computer-readable storage device or media may be implemented using a number of storage devices, such as PROMs (programmable read-only memories), EPROMs (erasable PROMs), EEPROMs (electrically erasable PROMs), flash memory, or other electrical, magnetic, optical, or combination storage devices capable of storing data, some of which may be executable instructions used by the controller 34 in controlling the vehicle 10. The controller 34 of the vehicle 10 may be referred to as a vehicle controller and may be programmed to implement a method 100 (. Fig. 16), which is described in detail below.

[0024] The instructions may include one or more redirection programs, each of which comprises an ordered list of executable instructions for implementing logical functions. The instructions, when executed by processor 44, receive and process signals from sensor system 28, perform logic, calculations, methods, and / or algorithms to automatically control the components of vehicle 10, and generate control signals for actuator system 30 to automatically control one or more components of vehicle 10 based on the logic, calculations, methods, and / or algorithms. Although a single controller 34 in Fig. 1, embodiments of the vehicle 10 may include a plurality of controllers 34 that communicate and cooperate via a suitable communication medium or combination of communication media to process the sensor signals, perform logic, calculations, methods, and / or algorithms, and generate control signals to automatically control functions of the vehicle 10. In various embodiments, one or more instructions of the controller 34 are embodied in the control system 98.

[0025] The vehicle 10 includes a user interface 23, which may be a touchscreen in the instrument panel. The user interface 23 may include, but is not limited to, an alarm, such as one or more speakers 27 for providing an audible tone, haptic feedback on a vehicle seat or other object, one or more displays 29, one or more microphones 31 (e.g., a microphone array), and / or other devices suitable for providing notification to the vehicle user of the vehicle 10. The user interface 23 is in electronic communication with the controller 34 and is configured to receive inputs from a user (e.g., a vehicle driver or a vehicle occupant). For example, the user interface 23 may include a touchscreen and / or buttons configured to receive inputs from a vehicle user 11 (e.g.,the vehicle driver). Accordingly, the control unit 34 is configured to receive user inputs via the user interface 23. Although the microphone 31 in . Fig. 1 as part of the user interface 23, other microphones 31 may be part of the sensor system 28. The microphones 31 may be directly coupled to a headliner 52 of the vehicle 10 to capture voice commands from one or more passengers 11 in the passenger compartment 54 of the vehicle 10. However, it is envisioned that the microphones 31 may be coupled to other parts of the vehicle 10. Regardless of its precise location, the microphone 31 is in communication with the control unit 34. Accordingly, the microphone 31 may send sensor data (e.g., voice commands) to the control unit 34.

[0026] The vehicle 10 may include one or more holographic displays 29 configured to display a 3D hologram 50 to one or more vehicle occupants 11. The holographic display 29 is configured to present one or more 3D holograms 50 to the vehicle occupants 11 in the passenger compartment 54. Although the holographic display 29 in Fig. 1 as part of the user interface 23, the holographic display 29 may be directly coupled to the headliner 52 of the vehicle 10 to present one or more 3D holograms 50 to the vehicle occupants 11 in the passenger compartment 54. However, it is conceivable that the holographic display 29 may be attached to another part of the vehicle 10. Regardless of its precise location, the holographic display 29 is in communication with the control unit 34. Accordingly, the control unit 34 is configured to control the operation of the holographic display 29.

[0027] The communication system 36 is in communication with the controller 34 and is configured to wirelessly transmit information to and from other remote vehicles 48, such as, but not limited to, other vehicles ("V2V" communication), infrastructure ("V2I" communication), remote systems at a remote call center (e.g., ON-STAR from GENERAL MOTORS), and / or personal devices such as a cellular phone. In the present disclosure, the term "remote vehicle" refers to a vehicle, such as a car, that is configured to send one or more signals to the vehicle 10 without being physically connected to the vehicle 10.

[0028] In certain embodiments, the communication system 36 is a wireless communication system configured to communicate over a wireless local area network (WLAN) using IEEE 802.11 standards or via cellular data communication. However, additional or alternative communication methods, such as a Dedicated Short Range Communication (DSRC) channel, are also contemplated within the scope of the present disclosure. DSRC channels refer to one-way or two-way, short- to medium-range wireless communication channels specifically designed for use in vehicles, as well as a corresponding set of protocols and standards. Accordingly, the communication system 36 may include one or more antennas and / or communication transceivers 37 for receiving and / or transmitting signals, such as Cooperative Sensing Messages (CSMs).The communication transceivers 37 can be considered sensors 40. The communication system 36 is configured to wirelessly transmit information between the vehicle 10 and another vehicle. Furthermore, the communication system 36 is configured to wirelessly transmit information between the vehicle 10 and the infrastructure or other vehicles.

[0029] With reference to Fig. 2 and Fig. 3, the vehicle 10 includes a passenger compartment 54 shaped and sized to accommodate a plurality of passengers (i.e., vehicle occupants 11). Furthermore, the vehicle 10 includes a plurality of seats 56 within the passenger compartment 54. The seats 56 are arranged in a campfire seating configuration. In other words, some groups of seats 56 face another group of seats 56, similar to how people sit around a campfire. The passenger compartment 54 is defined by the headliner 52 and a vehicle floor 58 of the vehicle 10.

[0030] With continued reference to Fig. 2 and Fig. 3, the haptic actuators 47 may be directly coupled to some or all of the seats 56 to provide haptic feedback to the vehicle occupants 11 seated in the seats 56. However, it is contemplated that the haptic actuators 47 may be coupled to other parts of the vehicle 10 within the passenger compartment 54. At least some of the sensors 40 may be directly coupled to the headliner 52 of the vehicle to facilitate detecting movements of the vehicle occupants 11 and voice commands from the vehicle occupants 11 within the passenger compartment 54. For example, the microphones 31 may be directly coupled to the headliner 52 of the vehicle 10 to detect voice commands from one or more vehicle occupants 11 (e.g., passengers) in the passenger compartment 54 of the vehicle 10.The 3D depth sensors 45 may be directly coupled to the headliner 52 of the vehicle 10 to facilitate sensing the 3D position of each vehicle occupant 11 within the passenger compartment 54 of the vehicle 10. The cameras 31 may be directly coupled to the headliner 52 of the vehicle 10 to facilitate sensing images of the vehicle occupants 11 within the passenger compartment 54. The user trackers 43 may include one or more cameras 31 to track the movements of the head 69 and / or eyes 66 of the vehicle occupant 11 within the passenger compartment 54. The user trackers 43 may also be referred to as eye trackers. The user trackers 43 may be directly coupled to the headliner 52 of the vehicle 10 to facilitate tracking of the head 69 and / or eyes 66 of the vehicle occupants 11 within the passenger compartment 54.

[0031] With further reference to Fig. 2 and Fig. 3, the holographic display 29 may be directly coupled to the headliner 52 of the vehicle 10 to present one or more 3D holograms 50 to the vehicle occupants 11 in the passenger compartment 54. However, it is conceivable that the holographic display 29 may be attached to another part of the vehicle 10. As shown in Fig. 3, the vehicle occupants 11 may sit around a shared 360-degree display (i.e., the holographic display 29). Each vehicle user 11 has a different personal view of the shared hologram 50 from their perspective. Each vehicle user 11 may use their hands 15, their eyes 66, and / or their voice to interact with and manipulate the hologram 50. Multiple vehicle occupants 11 may cooperate in manipulating the shared hologram 50 by simultaneously manipulating different parts of the hologram 50 (e.g., by virtually touching, bending, stretching, folding, twisting, etc.). In doing so, the perspective (i.e., the viewing angle) of the other users of the shared hologram is changed accordingly. The haptic actuator 47 may provide haptic feedback to the vehicle user 11 manipulating the hologram 50.The 3D hologram 50 extends 360 degrees around the holographic display 29 and may include, but is not limited to, an upcoming destination (e.g., stadium), the vehicle route and progress, information about vehicle technologies, internet research on any topic, information shared live by other people at another location outside the vehicle 10, etc.

[0032] With reference to Fig. 4, the holographic display 29 may be referred to as a floating autostereoscopic 3D display or a multiview campfire display. The configuration of the holographic display 29 allows for a reduction in the number of displays or optical complexity used to create a 3D campfire hologram. As such, the holographic display 29 is considered a true, floating-in-space holographic autostereoscopic 3D display. Accordingly, the vehicle 10 may include fewer holographic displays 29 than seats 56. The holographic display 29 controls the polarization optics to redirect the images for two or more viewers (i.e., vehicle occupants 11). The holographic display 29 may also enable sequential imaging for multiple users (i.e., vehicle occupants 11) with high illumination requirements. The holographic display 29 is in electronic communication with the controller 34.The controller 34 is also in communication with one or more user trackers 43. As discussed above, one or more cameras 31 can be configured as user trackers 43 to track the movements of the head 69 and / or eyes 66 of the vehicle user 11 within the passenger compartment 54. The user tracker 43 is configured to track the head and eyes of the vehicle occupants 11. For example, the user tracker 43 is configured to generate an eye tracking signal. The eye tracking signal is an indicator of the position of the eyes of each vehicle occupant 11.

[0033] With further reference to Fig. 4, the holographic display 29 includes one or more light sources 60 in communication with the controller 34. Accordingly, the controller 34 can control the operation of the light source 60. The light source 60 is configured to emit one or more light beams 62. The holographic display 29 further includes a spatial light modulator (SLM) 64 positioned to receive the light beam 62 emitted by the light source 60. Accordingly, the SLM 64 is in optical communication with the light source 60. The SLM 64 is an object that imposes some form of spatially varying modulation on a light beam. Accordingly, the SLM 64 is configured to modulate the light beam 62 and encode an image using the light beam 62.

[0034] With further reference to Fig. 4, the controller 34 is in communication with the user tracker 43, the light source 60, and the SLM 64 and is programmed to receive the eye-tracking signal. The controller 34 is further programmed to control the light source 60 and the SLM 64 to control the polarization optics control of the light beam 62 emitted by the light source 60 and modulated by the SLM 64 to redirect the image encoded by the SLM 64 to the vehicle occupants 11 based on the eye-tracking signal, thereby allowing each of the vehicle occupants 11 to view the image, as discussed in detail below. At least two reflectors 68 are positioned in optical communication with the SLM 64 to receive the modulated light by the SLM 64. The reflectors 68 serve as mirrors and are configured to reflect the light modulated by the SLM 64.As a non-limiting example, the reflectors 68 may be made of galvanized metal and are therefore galvanized metal mirrors. The reflectors 68 may be coated with a variety of reflective coatings with or without polarization-dependent properties. Movable mounts 70 are coupled to all or some of the reflectors 70 to allow the reflectors 70 to move. As a non-limiting example, the movable mounts 70 may be gimbal mounts to facilitate movement of the reflectors 68. The controller 34 is in communication with the movable mounts 70 and is programmed to instruct each of the movable mounts 70 to align the image with the eyes of each vehicle occupant 11 based on the eye tracking signals received from the user trackers 43.Thus, the movable mounts 70 cooperate with the user trackers 43 to align the images to the position of the eyes 66 of the vehicle occupants 11.

[0035] With further reference to Fig. 4, the controller 34 is programmed to control the light source 60 and the SLM 64 to use a holographic grating 72 to redirect the image encoded by the SLM 64. The holographic grating 72 is a type of diffraction grating formed by an interference fringe field of two laser beams whose standing wave pattern impinges on a series of light-sensitive materials. The holographic grating 72 is in optical communication with the light source 60 and the SLM 64 to redirect the image so that all vehicle occupants 11 can see the image. The holographic gratings 72 can be described by the frequency of grating lines, where: f=106Λ where: f is the grating frequency in lines / mm Λ, where the grating period is in nm.

[0036] The lattice equation can be expressed as follows: sinθm=sinθ+mλΛ where: θ is the angle of the incident light relative to the grating normal; θ m is the diffraction angle of the m-th order relative to the grating normal; m is the diffraction order number; λ is the illumination wavelength; and Λ, where the grating period is in nm.

[0037] With reference to Fig. 5, instead of holographic gratings 72, the holographic display 29 includes a digital micromirror device (DMD) 74 that is in optical communication with the reflectors 68. The DMD 74 can encode images and is a digitally controlled spatial light modulator (SLM) of a micro-opto-electromechanical system (MOEMS) and can modulate the amplitude and direction of the light beam 62. The DMD 74 includes an array of mirrors and can generate light patterns with speed, precision, and efficiency. Accordingly, the DMD 74 is positioned to receive the image encoded by the SLM 64 after the light has been reflected from the reflectors 68. The DMD 74 is configured to redirect the image encoded by the SLM 64 to the vehicle occupants 11. The DMD 74 is in communication with the control unit 34.The controller 64 is programmed to control the DMD 74 to redirect the image encoded by the SLM 64 to the vehicle occupants 11 based on the eye tracking signal generated by the user trackers 43, thereby allowing each of the vehicle occupants 11 to view the image.

[0038] With reference to Fig. 6, instead of the DMD 74 or the holographic gratings 72, the holographic display 29 includes a tunable liquid crystal (LC) polarization rotator 76 in communication with the controller 34. The tunable LC polarization rotator 76 is positioned to receive the image encoded by the SLM 64. The controller 34 is programmed to control the tunable LC polarization rotator 76 to redirect the image encoded by the SLM 64 to the vehicle occupants 11 based on the eye-tracking signal, thereby allowing each of the vehicle occupants 11 to view the image. The LC polarization rotator 76 comprises a variable liquid crystal retarder and a zero-order quartz quarter-waveplate, with the fast axes of the LC retarder and the waveplate aligned at 45° to each other. When a voltage is applied to the tunable liquid crystal (LC) polarization rotator 76, the image is redirected.However, if no voltage is applied to the tunable liquid crystal (LC) polarization rotator 76, the image changes path and is redirected. A polarized beam splitter (PBS) 78 is positioned downstream of the tunable LC polarization rotator 76. The PBS 78 is configured to redirect the image encoded by the SLM 64. Linear polarizers 80 are positioned downstream of the PBS 78 to minimize polarization loss. The wavelength of polarization rotation is wavelength-dependent. This rotates the polarization of the R, G, and B beams differently, resulting in some polarization scattering by the linear polarizers 80 after the PBS 78 is aligned to the appropriate polarization states to help reduce or eliminate scattering.

[0039] Fig.7 is a flowchart of a method 100 for displaying a hologram to multiple vehicle occupants 11 within the vehicle 10. The method 100 begins at block 102. At block 102, the controller 34 activates the light source 60 to emit the light beam 60. The method 100 then proceeds to block 104. At block 104, the light beam 62 is modulated by the SLM 64 to encode an image. The method 100 then proceeds to block 106. At block 106, the polarization optics of the light beam 62 are controlled, as described in detail above, to redirect the image encoded by the SLM 64 so that each vehicle occupant 11 can view the image.

[0040] Although exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms encompassed by the claims. The words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the disclosure. As previously described, the features of various embodiments may be combined to form other embodiments of the presently disclosed system and method that may not be explicitly described or illustrated.Although various embodiments may have been described as providing advantages or being preferred over other prior art embodiments or designs with respect to one or more desired characteristics, those of ordinary skill in the art will recognize that one or more features or properties may be compromised to achieve desired overall system attributes depending on the specific application and design. These attributes may include, but are not limited to, cost, strength, durability, life cycle cost, marketability, appearance, packaging, size, usability, weight, manufacturability, ease of assembly, etc.As such, embodiments that are described as less desirable than other embodiments or prior art embodiments with respect to one or more characteristics are not outside the scope of the disclosure and may be desirable for certain applications.

[0041] The drawings are presented in simplified form and are not to scale. For convenience and clarity, and for these reasons only, directional terms such as top, bottom, left, right, upward, above, above, below, below, back, and front may be used with reference to the drawings. These and similar directional terms should not be construed to limit the scope of the disclosure in any way.

[0042] Embodiments of the present disclosure are described herein. However, it should be understood that the disclosed embodiments are merely examples, and other embodiments may take various and alternative forms. The figures are not necessarily to scale; some features may be larger or smaller to show details of particular components. Therefore, the specific structural and functional details disclosed herein are not to be considered limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the presently disclosed system and method.As one of ordinary skill in the art will understand, various features illustrated and described with reference to one of the figures may be combined with features illustrated in one or more of the other figures to produce embodiments not explicitly illustrated or described. The illustrated feature combinations provide representative embodiments for typical applications. However, various combinations and modifications of the features consistent with the teachings of this disclosure may be desired for particular applications or implementations.

[0043] Embodiments of the present disclosure may be described herein in terms of functional and / or logical block components and various processing steps. It should be understood that such block components may be implemented by a number of hardware, software, and / or firmware components configured to perform the specified functions. For example, an embodiment of the present disclosure may utilize various integrated circuit components, e.g., memory elements, digital signal processing elements, logic elements, lookup tables, or the like, capable of performing a plurality of functions under the control of one or more microprocessors or other control devices.Furthermore, those skilled in the art will recognize that embodiments of the present disclosure may be used in connection with a number of systems and that the systems described herein are merely embodiments of the present disclosure.

[0044] For the sake of brevity, a detailed description of techniques for signal processing, data fusion, signaling, control, and other functional aspects of the systems (and the individual operating components of the systems) is omitted. Furthermore, the connecting lines depicted in the various figures included herein are intended to represent exemplary functional relationships and / or physical connections between the various elements. It should be noted that alternative or additional functional relationships or physical connections may be present in an embodiment of the present disclosure.

[0045] This description is merely illustrative and is not intended to limit the disclosure, its application, or uses in any way. The broad teachings of the disclosure may be embodied in a variety of forms. Therefore, while this disclosure includes specific examples, the true scope of the disclosure should not be limited thereto, since other modifications will become apparent upon study of the drawings, the patent specification, and the following claims.

Claims

[1] Multiview Campfire display, including: a light source configured to emit a beam of light; a spatial light modulator (SLM) positioned to receive the light beam emitted by the light source, the SLM configured to encode an image; a user tracker configured to track the head and eyes of a plurality of vehicle occupants, the user tracker configured to generate an eye tracking signal, the eye tracking signal indicative of a position of the eyes of each of the plurality of vehicle occupants; and a control unit in communication with the user tracker, the light source and the SLM, the control unit being programmed to: receives the eye tracking signal from the user tracker; and controls a polarization optics of the light beam emitted by the light source and modulated by the SLM to redirect the image encoded by the SLM for the plurality of vehicle occupants based on the eye tracking signal; The Multiview Campfire display allows a large number of vehicle occupants to see the image due to multiplexing. [2] The multiview campfire display of claim 1, wherein the user tracker comprises at least one camera. [3] The multi-view campfire display of claim 2, further comprising a plurality of reflectors and a plurality of movable mounts each coupled to one of the plurality of reflectors to allow each of the plurality of reflectors to move, the controller being in communication with the plurality of movable mounts, the controller being programmed to instruct each of the plurality of movable mounts to align the image with the eyes of each of the plurality of vehicle occupants. [4] The multiview campfire display of claim 3, wherein each of the plurality of reflectors is a galvanized metal mirror. [5] The multiview campfire display of claim 4, wherein each of the plurality of movable mounts is a gimbal mount. [6] The multiview campfire display of claim 5, wherein the controller is programmed to control the light source and the SLM to use a holographic grating to redirect the image encoded by the SLM. [7] The multiview campfire display of claim 5, further comprising a digital micromirror device (DMD) positioned to receive the image encoded by the SLM, the DMD also being configured to redirect the image encoded by the SLM for the plurality of vehicle occupants, the DMD being in communication with the controller, the controller being programmed to control the DMD to redirect the image encoded by the SLM for the plurality of vehicle occupants based on the eye tracking signal, thereby enabling each of the plurality of vehicle occupants to view the image. [8] The multiview campfire display of claim 5, further comprising a tunable liquid crystal (LC) polarization rotator in communication with the controller, the tunable LC polarization rotator positioned to receive the SLM encoded image, the controller programmed to control the tunable LC polarization rotator to redirect the SLM encoded image for the plurality of vehicle occupants based on the eye tracking signal, thereby enabling each of the plurality of vehicle occupants to view the image. [9] The multiview campfire display of claim 8, further comprising a polarized beam splitter (PBS) downstream of the tunable LC polarization rotator, the PBS configured to redirect the image encoded by the SLM. [10] The multiview campfire display of claim 9, wherein each of the plurality of reflectors is disposed downstream of the PBS to direct the image toward the eyes of each of the plurality of vehicle occupants.

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