Vehicle display system and method with multifunctional holographic rlad device

Abstract

A holographic projection display system includes a cluster of lighting elements arranged in a fixed lighting array. The cluster of lighting elements includes a first set of light emitting diodes emitting light of a first wavelength and each having a respective emission angle toward the reflective surface, and a second set of light emitting diodes emitting light of a second wavelength. The second set of light emitting diodes emits light of a second wavelength and each light emitting diode has a respective emission angle toward the reflective surface. A multi-layer holographic optical element (HOE) assembly is attached to the illumination cluster in front of the two light emitting diode groups. The multi-layer HOE assembly includes a pair of stacked mutually parallel holographic panels including a first holographic panel recorded with a plurality of holographic patterns each optically configured to diffract a wavelength of light emitted by a first light emitting diode and a second holographic panel recorded with a plurality of holographic patterns each optically configured to diffract a wavelength of light emitted by a second light emitting diode. Each second holographic pattern is optically configured to diffract the wavelength of light emitted by the second light emitting diode.

Description

TECHNICAL FIELD

[0001] The present disclosure relates generally to display systems for motor vehicles. More particularly, aspects of the present disclosure relate to digital projection display devices for presenting vehicle information and driving alerts to automotive occupants. BACKGROUND

[0002] Most currently produced motor vehicles, such as modern automobiles, are fitted with a rigid bodyshell (either as a body-on-frame or monocoque structure) having an interior passenger compartment for seating and protecting vehicle occupants. Mounted between the front A-pillars of the bodyshell is a windshield (or “windscreen” in some countries) that prevents the unwanted ingress of wind, rain, and debris while providing an aerodynamically formed window through which the driver views the road. An instrument panel (commonly referred to as the “cluster” or “IP”) is located below the windshield and in front of the driver’s seat, and contains various digital and electromechanical dials, gauges, meters, and indicators for relaying information about the vehicle to the driver. Vehicle telematics and information (“telematics”) units can be inserted within the centerstack portion of the instrument panel to provide occupants with an in-vehicle computing device that offers a mix of services including feedback and control over various vehicle subsystems.

[0003] To improve the driver’s awareness of vehicle system operation and environmental driving conditions, some modern vehicles supplement telematics units and IPs with heads-up display (HUD) devices having transparent (“see-through”) display panels that display information within the viewing envelope of the windshield. Automotive HUDs are designed to present information within the operator’s forward driving field of view, and thus reduce redundant eye scanning and saccadic behavior at the instrument panel and centerstack. Due to the inherent cost and complexity of integrating a separate transparent display panel for the HUD, some vehicles instead use a reflective light-emitting diode (LED) alert display (RLAD) to present warnings and notifications to the driver by projecting LED source light onto the interior surface of the vehicle windshield. However, current RLAD systems are generally only capable of projecting basic geometric shapes in a fixed color, and are thus limited in the type of information that can be displayed to the driver. SUMMARY

[0004] Provided below are vehicle display systems with multi-functional holographic RLAD devices, methods of manufacturing and operating such vehicle display systems, and motor vehicles equipped with such display systems. As a non-limiting example, the holographic RLAD device includes a fixed set of illumination elements, such as a mixed series of red and green LEDs or laser diodes arranged in a one-dimensional (ID) or two-dimensional (2D) array. For a given color, each illumination element is set at a different emission angle, which can be achieved using light-redirecting prisms on top of the LEDs or angled reflectors behind the LEDs. A multi-layer holographic optical element (HOE) is mounted in front of the set of illumination elements such that the reference light beams emitted by each LED / laser diode pass through the multi-layer HOE. In an example, the HOE consists essentially of two stacked and mutually parallel holographic panels, where one layer is optically configured to diffract light of only a first wavelength (e.g., green), and the other layer is optically configured to diffract light of only a second wavelength (e.g., red). Each holographic layer has recorded therein one or more holographic patterns that each generate a predefined warning icon when illuminated with the corresponding wavelength at a respective incidence angle. Additional or alternative icons / patterns can be added to the holographic RLAD device module by replacing or adding new holographic layers instead of having to replace the entire module.

[0005] Aspects of the present disclosure relate to digital projection display devices having a multi-layer holographic panel structure for projecting complex and irregular geometric icons. In an example, a holographic projection display system is presented for projecting an image onto a reflective surface, such as an interior side surface of a windshield of an automobile. The holographic projection display system includes a cluster of illumination elements arranged in a predetermined pattern and attached to a multi-layer HOE assembly. The cluster of illumination elements includes at least two groups of light emitting diodes: a first group of light emitting diodes that emit light of a first wavelength and each has a respective emission angle toward the reflective surface, and a second group of light emitting diodes that emit light of a second wavelength and each has a respective emission angle toward the reflective surface. The multi-layer HOE assembly is positioned in front of the cluster of light emitting diodes and includes at least two holographic layers: a first holographic panel having recorded therein a plurality of holographic patterns each optically configured to diffract the wavelength of light emitted by the first group of light emitting diodes, and a second holographic panel attached to the first holographic panel and having recorded therein a plurality of holographic patterns each optically configured to diffract the wavelength of light emitted by the second group of light emitting diodes.

[0006] Additional aspects of the present disclosure relate to a motor vehicle equipped with a multi-functional holographic RLAD device. As used herein, the terms "vehicle" and "motor vehicle" can be used interchangeably and synonymously to include any relevant vehicle platform, such as passenger cars, commercial vehicles, industrial vehicles, off-road and all-terrain vehicles (ATVs), motorcycles, farm equipment, aircraft, spacecraft, watercraft, etc. In an example, the motor vehicle includes a vehicle body having a passenger cabin, a plurality of wheels attached to the vehicle body (e.g., via corner modules coupled to an integrated or frame-on body chassis), and other standard original equipment. A prime mover, which can be an electric traction motor and / or an internal combustion engine (ICE) assembly in nature, is located inside the vehicle body and drives the wheels to propel the vehicle. It is contemplated that the disclosed display designs and features can be used equally in vehicle and non-vehicle applications.

[0007] Continuing the discussion of the preceding example, the vehicle is also equipped with a holographic projection display system mounted within the passenger cabin (e.g., on or in the instrument panel, rearview mirror, or headliner). The holographic projection display system includes a cluster of illumination elements arranged in a fixed light array and attached to a multi-layer HOE assembly. The cluster of illumination elements includes a plurality of groups of light emitting diodes, such as a first group of light emitting diodes that emit a first wavelength of light and each has a respective emission angle toward a vehicle windshield, and a second group of light emitting diodes that emit a second wavelength of light different from the first wavelength and each has a respective second emission angle toward the windshield. The emission angles of the first light emitting diodes are different from one another, and the emission angles of the second light emitting diodes are different from one another.

[0008] The multi-layer HOE assembly is located in front of the groups of light emitting diodes and includes a plurality of holographic layers, such as a first holographic panel stacked and mounted on a second holographic panel. The first holographic panel is recorded with a plurality of holographic patterns each optically configured to diffract only the wavelength of light emitted by the first light emitting diodes at their respective emission angles. Likewise, the second holographic panel is recorded with a plurality of holographic patterns each optically configured to diffract only the wavelength of light emitted by the second light emitting diodes at their respective emission angles.

[0009] Aspects of the present disclosure also relate to methods for manufacturing any of the holographic projection display apparatuses, vehicle display systems, and motor vehicles described herein and methods for operating any of the holographic projection display apparatuses, vehicle display systems, and motor vehicles described herein. In an example, a method for assembling a holographic projection display system for projecting an image onto a reflective surface is presented. The representative method includes, in any order and in any combination with any of the above and below disclosed options and features: arranging a cluster of illumination elements in a predefined pattern, the cluster of illumination elements including: a plurality of first light emitting diodes of a first light wavelength, and each first light emitting diode having a respective first emission angle toward the reflective surface, and a plurality of second light emitting diodes of a second light wavelength, and each second light emitting diode having a respective second emission angle toward the reflective surface; and attaching a multi-layer holographic optical element assembly to the cluster of illumination elements in front of the plurality of first and second light emitting diodes, the multi-layer HOE assembly including: a first holographic panel having one or more first holographic patterns recorded therein, each first holographic pattern being optically configured to diffract the first light wavelength of the first light emitting diodes emitted at one or more respective first emission angles, and a second holographic panel attached to the first holographic panel, the second holographic panel having one or more second holographic patterns recorded therein, each second holographic pattern being optically configured to diffract the second light wavelength of the second light emitting diodes emitted at one or more respective second emission angles.

[0010] For any of the disclosed vehicles, systems, and methods, at least one of the holographic patterns recorded in the first holographic panel can be optically configured to diffract light of the first wavelength emitted at only a respective emission angle of a single one of the first light emitting diodes. Likewise, at least one of the holographic patterns recorded in the second holographic panel can be optically configured to diffract light of the second wavelength emitted at only a respective emission angle of a single one of the second light emitting diodes. As another option, at least one of the holographic patterns recorded in the first holographic panel can be optically configured to diffract light of the first wavelength emitted at respective emission angles of two of the first light emitting diodes. Likewise, at least one of the holographic patterns recorded in the second holographic panel can be optically configured to diffract light of the second wavelength emitted at respective emission angles of two of the second light emitting diodes. In this example, the respective emission angles of the two first light emitting diodes are different from each other, and the respective emission angles of the two second light emitting diodes are different from each other.

[0011] For any of the disclosed vehicles, systems, and methods, the second holographic panel can include one or more optically transparent regions that lack a holographic pattern; each optically transparent region can overlap with one of the holographic patterns recorded in the first holographic panel. As another option, one of the first holographic patterns can diffract only light wavelengths emitted at a respective emission angle of a respective first light emitting diode, and one of the second holographic patterns can diffract only light wavelengths emitted at a respective emission angle of a respective second light emitting diode. In this example, the first holographic patterns overlap with the second holographic patterns such that light diffracted by the overlapping holographic patterns combine to project a combined image of a third light wavelength (e.g., yellow) different from the first and second wavelengths (e.g., red and green). Moreover, the respective emission angles of the respective first light emitting diodes can be different from the respective emission angles of the respective second light emitting diodes.

[0012] For any of the disclosed vehicles, systems, and methods, the first holographic panel can be mounted to the second holographic panel using an optically transparent adhesive layer, a mounting bracket, and / or a set of fasteners. As another option, the holographic projection display system can employ a plurality of optical prisms or reflectors, each optical prism or reflector located proximate a respective one of the light emitting diodes to direct a reference light beam emitted from the light emitting diode at a respective emission angle of the diode. As yet another option, the plurality of sets of light emitting diodes can be mounted in a fixed light array that contains a single row (ID) of diodes or multiple rows (2D) of diodes. The set of light emitting diodes can be implemented as light emitting diodes, laser diodes, or a combination of both. As another option, the first holographic panel can be mounted to the second holographic panel and substantially parallel to the second holographic panel. Each holographic panel can be a substantially planar and optically transparent single piece panel structure.

[0013] The above summary of the present disclosure does not represent each and every embodiment or aspect of the present disclosure. To the contrary, the foregoing summary merely provides a concise explanation of some of the novel concepts and features set forth throughout the present disclosure. Such novel concepts and features will become apparent to those skilled in the art upon reviewing the following detailed description of the illustrated examples and representative modes for carrying out the present disclosure as well as the appended claims in conjunction with the accompanying drawings. Moreover, it is to be understood that both the foregoing summary and the following detailed description are merely exemplary of the aspects and features of the present disclosure, and are intended to provide additional descriptions of the methods and systems of the present disclosure as defined by the appended claims. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 is a front perspective view illustration of a portion of a passenger cabin of a representative motor vehicle having a multi-mode information display system with a multi-functional holographic RLAD device in accordance with aspects of the present disclosure.

[0015] Figure 2 is a schematic illustration of a representative holographic projection display system in accordance with aspects of the present disclosure.

[0016] Figure 3 is a schematic diagram of another representative holographic projection display system in accordance with aspects of the present disclosure.

[0017] Figure 4 is a flowchart showing a representative display system control protocol for operating a multi-functional holographic RLAD device in accordance with aspects of the disclosed concept, which can correspond to non-transitory memory stored instructions executable by a resident or remote microprocessor, control module, logic circuit, central controller, or other integrated circuit (IC) device or network of circuitry / modules / microprocessors / controllers / IC devices (collectively, “controller”).

[0018] The present disclosure is susceptible to various modifications and alternative forms, and some representative embodiments thereof have been shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that the novel aspects of the present disclosure are not limited to the particular forms shown in the attached drawings. Rather, the present disclosure is to cover all modifications, equivalents, combinations, substitutions, improvements, and alternatives falling within the scope of the disclosure as encompassed by the appended claims. DETAILED DESCRIPTION

[0019] The present disclosure allows for a great variety of embodiments. Representative embodiments of the present disclosure are shown in the drawings and will be described in detail herein, it being understood that these embodiments are provided by way of example only and not by way of limitation to the broad aspects of the present disclosure. To this end, elements described, for example, in the Abstract, Background, Summary, Brief Description of Drawings and Detailed Description sections, but not expressly set forth in the claims, should not be incorporated by reference into the claims, by implication, inference or otherwise. Further, recitations in the specification or claims of “first,” “second,” “third,” etc. are not to be construed as establishing a series or numerical limitation unless specifically so stated; unless otherwise specifically stated, such designations can be used to facilitate reference to like features in the specification and drawings, and to divide between like elements in the claims.

[0020] For purposes of this disclosure, unless specifically denied: singular includes plural, and vice versa (e.g., the indefinite articles “a” and “an” should generally be interpreted to mean “one or more”); the words “and” and “or” shall be both conjunctive and disjunctive; the words “any” and “all” mean “any and all”; and the words “including,” “containing,” “comprising,” “having,” and the like shall each mean “including, without limitation.” Furthermore, words of approximation, such as “about,” “nearly,” “substantially,” “generally,” “approximately,” and the like, can each be used herein to mean, for example, “within 0-5% of,” or “within acceptable manufacturing tolerances,” or any logical combination thereof. Finally, directional adjectives and adverbs, such as front, rear, inboard, outboard, starboard, port, vertical, horizontal, upward, downward, forward, aft, left, right, and the like, can be relative to a motor vehicle, such as the forward driving direction of a motor vehicle when the vehicle is operably oriented on a horizontal driving surface.

[0021] Reference is now made to the drawings wherein like reference numerals designate the same features in several views, and wherein Figure 1 A representative motor vehicle is shown in FIG. 1 and is generally designated 10, and is depicted herein for purposes of discussion as a sedan-type passenger car. The illustrated automobile 10 (also referred to herein simply as a “motor vehicle” or “vehicle”) is merely an exemplary application in which aspects of the present disclosure can be practiced. Likewise, the projection of information onto the front windshield of an automobile using the present concepts should be understood as a non-limiting implementation of the disclosed features. Accordingly, it should be understood that aspects and features of the present disclosure can be implemented to project information onto other vehicle surfaces (e.g., rear windows and rear glass, side door windows, etc.), for any logically relevant type of motor vehicle, and implemented for both automotive and non-automotive applications. Moreover, only select components of the motor vehicle and vehicle display system are shown and described in detail herein. However, the vehicle and system discussed below can include many additional and alternative features for performing the various methods and functions of the present disclosure, as well as other available peripheral hardware.

[0022] To protect the vehicle occupants from inclement weather and road debris, a front windshield 18 is located between two A-pillars 24 at the front end of a passenger cabin 14 of a body 12 of the automobile 10. According to the illustrated example, the front windshield 18 is sealingly fastened to a front window frame 16, e.g., via adhesives and window gaskets or polymeric weatherstrips. The lower edge of the front window frame 16 is delineated by an instrument panel cowl 20, while the upper edge is delineated by a roof rail 22, and the two side edges of the frame 16 are delineated by a pair of A-pillars 24 (only one of which is visible, with a second, mirror-image counterpart located on the opposite side of the window frame 16). Also present within the vehicle passenger cabin 14 is a load-bearing center console 26, which houses a vehicle telematics unit, which in turn is in communication with a vehicle head unit, which is in communication with a vehicle infotainment system, which is in communication with a vehicle display screen 28, which is in communication with a vehicle driver and passengers. Figure 1The center is represented by an interactive touchscreen video display device 28 and a user input button panel 30. The touchscreen video display 28 is operable to receive user input via soft touch controls and simultaneously display images, text, and video-based content. A digital instrument panel (IP) 32 is housed within a front dashboard 34 forward of a steering wheel 36 and displays gauges, instruments, and controls for monitoring and adjusting selected operations of the vehicle 10 (e.g., speedometer, tachometer, odometer, fuel gauge, engine temperature gauge, warning lights, etc.). It should be understood that the disclosed display devices and accompanying features are not limited to Figure 1 The particular passenger cabin layout presented in the center.

[0023] A multi-functional holographic RLAD device 150 is recessed into the top surface of the front dashboard 34, which is part of an in-vehicle augmented display system (EDS) for dynamically presenting information to the vehicle occupants to enhance the operation of the automobile 10. For example, the holographic RLAD device 150 is operable to selectively project graphical images and data onto the front windshield 18 to present various forms of vehicle-related and non-vehicle-related information, including real-time vehicle system operations, environmental driving conditions, infotainment features, personalized occupant-specific data, etc. The holographic RLAD device 150, electronic touchscreen video display 28, button panel 30, and digital IP 32 are in wired or wireless communication with a programmable electronic control unit (ECU) 38. The vehicle ECU 38 can systematically monitor various sensors, system components, and / or other related inputs that are manual and automatic, and based on these monitored inputs, identify information to be relayed to the vehicle occupants or passing pedestrians, vehicles, etc., and determine graphical representations of the selected information. This ECU 38 can be in direct communication with various systems, subsystems, and components, or the ECU 38 can alternatively or additionally communicate over a distributed computing network, such as a LAN / CAN system, satellite system, the Internet, etc. Various vehicle sensors can be prompted to monitor vehicle speed, engine speed, transmission status, engine coolant temperature, fuel level and economy, oil level, tire pressure, wheel slip, battery state of charge (SOC), battery range, mileage, navigation information, and / or any other parameters indicative of vehicle operation.

[0024] The front windshield unit 18 serves as an aerodynamic deflector and a reflective display surface onto which the holographic RLAD device 150 projects alerts, icons, and other data. Specifically, the RLAD display device 150 is capable of dynamically displaying images on the front windshield 18 that are superimposed within the occupant’s forward field of view through the windshield 18. The EDS graphics engine (implemented as a dedicated software application within the ECU 38 or a discrete control module) includes, for example, display software stored as processor-executable code by memory that converts data and user requests into graphical representations of the desired information. To provide a “see-through” function, the front windshield 18 remains sufficiently transparent to allow the occupants of the vehicle 10 to clearly see objects outside the passenger cabin 14 through the front windshield 18 while selected images are displayed by the RLAD display device 150 within one or more embedded viewing areas. As non-limiting examples, Figure 1 The front windshield unit 18 of FIG. 1 includes a transparent display area Al onto which images and data are projected within the driver’s field of view. It is of course within the scope and spirit of the present disclosure for the front windshield unit 18 to provide additional or alternative transparent display areas, any or all of which can include shapes, sizes, and / or locations that differ from those shown in the figures.

[0025] Figure 2 and Figure 3 Two representative examples of holographic projection display systems 250 and 350 are presented that can be implemented as a multi-functional holographic RLAD device 150 for dynamically displaying information to the driver of the vehicle 10 of FIG. 1. Although the appearances differ, it is contemplated that any of the options and features described herein with reference to the display system 250 of FIG. 2 can be incorporated individually or collectively into the display system 350 of FIG. 3. Figure 1 The display system 250 of FIG. 2 is implemented as a multi-functional holographic RLAD device 150 for dynamically displaying information to the driver of the vehicle 10 of FIG. 1. Although the appearances differ, it is contemplated that any of the options and features described herein with reference to the display system 250 of FIG. 2 can be incorporated individually or collectively into the display system 350 of FIG. 3. Figure 2 The display system 250 of FIG. 2 is implemented as a multi-functional holographic RLAD device 150 for dynamically displaying information to the driver of the vehicle 10 of FIG. 1. Although the appearances differ, it is contemplated that any of the options and features described herein with reference to the display system 250 of FIG. 2 can be incorporated individually or collectively into the display system 350 of FIG. 3. Figure 3In display system 350, the opposite is also true. By way of example, and without limitation, both display systems 250, 350 can be represented by two interoperable subsystems: (1) a cluster of hybrid lighting elements 252 and 352 arranged in a preset light pattern; and (2) a multi-layer holographic optical element (HOE) assembly 254 and 354 fixedly attached to the light cluster 252, 352 and positioned in front of the light emitting diodes 256A, 256B, 356A, and 356B in the light cluster 252, 352. The lighting elements 252, 352 of each cluster include at least two different groups of light emitting diodes: (1) a primary color (first) group (first) light emitting diodes 256A, 356A sharing a common (first) light wavelength (e.g., green); and (2) a secondary color (second) group light emitting diodes 256B, 356B sharing another common (second) light wavelength (e.g., red). It can be desirable to mount the light emitting diodes 256A, 256B, 356A, 356B in a given light cluster 252, 352 in a fixed light array having a single straight line of diodes (1D) Figure 3 ) or multiple straight lines and columns of diodes (2D) Figure 2 ). Alternatively, the lighting elements 252, 352 of the cluster can be arranged in a 3D array of diodes and / or arranged in a pivotable / translateable array of diodes. It is also contemplated that each of the light emitting diodes 256A, 256B, 356A, and 356B can take any suitable lighting element form factor, including single color LEDs, RGB LEDs, SMD LEDs, semiconductor laser diodes, fiber optic lasers, and the like.

[0026] Unlike conventional RLAD and HUD system configurations, each light emitting diode 256A, 356A in the primary light emitting diode group can have a respective (first) light emission angle (e.g., first and second primary beam angles θ A1 and θ A2 ) that is different from the light emission angles of the other light emitting diodes 256A, 356A in the group and that is directed toward the reflective surface 218. For example, Figure 2 all four green light emitting diodes 256A in have respective beam angles that are different from one another, and Figure 2 all four red light emitting diodes 256B in have respective beam angles that are different from one another. Likewise, each light emitting diode 256B, 356B in the secondary light emitting diode group has a respective (second) light emission angle (e.g., first and second secondary beam angles θ B1 and θ B2 ) that is different from the light emission angles of the other light emitting diodes 256B, 356B in the group. Although in Figure 2The diagram shows a total of eight (8) diodes—four green LEDs 256A and four red LEDs 256B—and in Figure 3 The diagram shows a total of four (4) diodes—one green LED 356A and three red LEDs 356B—but the cluster of mixed lighting elements 252, 352 may include any number and combination of LEDs to suit the intended application.

[0027] Each lighting element can be positioned at its different emission angle using, for example, a light-directing prism mounted in front of the lighting element or an angled light reflector mounted behind the lighting element. Figure 2 For example, the main (first) group of light reflectors 258A, together with the illumination element cluster 252 and the HOE component 254, is encapsulated within a protective display system housing 260. Each of these light reflectors 258A is located directly behind or external to a corresponding light-emitting diode 256A, and reflects the reference beam emitted from it at the corresponding emission angle of that diode 256A. An auxiliary (second) group of light reflectors 258B is also encapsulated within the display system housing 260; each light reflector 258B is located directly behind or external to a corresponding light-emitting diode 256B, and reflects the reference beam emitted from it at the corresponding emission angle of that diode 256B.

[0028] In comparison, Figure 3 A primary (first) group of optical prisms 358A is shown, which, along with the illumination element cluster 352 and HOE assembly 354, is encapsulated within a protective display system housing 360. Each of these optical prisms 358A is located directly in front of or at a desired lateral offset from a corresponding light-emitting diode 356A, and refracts a reference beam emitted from it at a corresponding emission angle of that diode 356A. An auxiliary (second) group of optical prisms 358B is also encapsulated within the display system housing 360; each optical prism 358B is located directly in front of or at a desired lateral offset from a corresponding light-emitting diode 356B, and refracts a reference beam emitted from it at a corresponding emission angle of that diode 356B. It is also conceivable that display systems 250, 350 may omit some or all of the prisms and deflectors shown, instead individually orienting each illumination element at different beam angles.

[0029] Multilayer HOE components 254, 354 are shown inserted between the illumination element clusters 252, 352 and the reflective surfaces 218, 318, such that a reference beam emitted by each light-emitting diode 256A, 256B, 356A, 356B passes through the HOE components 254, 354 and projects one or more alarm icons 220A-220C and 320A-320C onto the reflective surfaces 218, 318. Each HOE component 254, 354 includes at least two holographic layers: primary (first) holographic panels 262A and 362A recording one or more primary (first) holographic patterns 264A, 364A; and (2) secondary (secondary) holographic panels 262B and 362B, which are adjacent to the primary holographic panels 262A, 362A and recording one or more secondary (secondary) holographic patterns 264B, 364B. According to the example shown, each of the holographic panels 262A, 262B, 362A, and 362B can be manufactured as a substantially flat and optically transparent monolithic panel structure from a recordable photosensitive material (e.g., a photopolymerizable monomer and glass). Alternatively, the main holographic panels 262A and 362A can be physically attached to the auxiliary holographic panels 262B and 362B, for example, via an optically transparent adhesive layer 266, a mounting bracket, a set of fasteners, etc. Figure 2 The main holographic panel 262A is shown as being directly mounted on the auxiliary holographic panel 262B and is substantially parallel to the auxiliary holographic panel 262B.

[0030] Continue to refer to Figure 2 and 3 Each of the holographic patterns 264A and 364A recorded on the main holographic panels 262A and 362A is optically configured to diffract a shared wavelength of light (e.g., green) emitted by the main light-emitting diodes 256A and 356A at their respective emission angles. Similarly, each of the auxiliary holographic patterns 264B and 364B is optically configured to diffract a shared wavelength of light (e.g., red) emitted by the auxiliary light-emitting diodes 256B and 356B at their respective emission angles. The holographic panels 262A, 362A, 262B, and 362B may be formed wholly or partially of a photosensitive material that locally alters its internal refractive index and / or light absorption coefficient according to the intensity of the incident light. An interference pattern formed by the interference between coherent or partially coherent light from a reference beam and light from an object can illuminate the photosensitive material and produce a change in refractive index / absorbance on the panel. The interference pattern can be different for different combinations of reference beams, and therefore, the distribution of the refractive index or absorbance change on the panel can be different.

[0031] Each recorded holographic pattern can diffract the wavelengths of light emitted by individual illumination elements in the illumination element. For example, Figure 3The rightmost holographic pattern 364B can only diffract the (red) light wavelength emitted by the rightmost auxiliary light-emitting diode 356B at its corresponding light emission angle (e.g., +5° from the vertical direction), while Figure 3 The central holographic pattern 364B diffracts only the (red) light wavelength emitted by the central auxiliary light-emitting diode 356B at its corresponding emission angle (e.g., -15° from the vertical direction). In other words, none of these holographic patterns 364B are optically configured to diffract light of different wavelengths or at different angles. For comparison, Figure 3 The leftmost main holographic pattern 364A can diffract only the (green) light wavelength emitted by the leftmost main light-emitting diode 356A at its corresponding light emission angle (e.g., approximately -25° from vertical), without diffracting the (red) light wavelength emitted by the leftmost auxiliary light-emitting diode 356B. Conversely, Figure 3 The leftmost auxiliary holographic pattern 364B can only diffract the (red) light wavelength emitted by the leftmost auxiliary light-emitting diode 356B at its corresponding light emission angle (e.g., +10° from the vertical direction), without diffracting the (green) light wavelength emitted by the leftmost main light-emitting diode 356A.

[0032] Each recorded holographic pattern can diffract light wavelengths emitted by a selected combination of illumination elements. For example, Figure 2 The leftmost holographic pattern 264A can diffract only the (green) light wavelength emitted by the two left main light-emitting diodes 256A at their respective light emission angles (e.g., projecting a larger and brighter animal alarm icon 220A). The holographic pattern 264A does not diffract light of different wavelengths (red) or light at different angles (regardless of color). On the other hand, Figure 2 The rightmost holographic pattern 264B can diffract only the (red) light wavelength emitted by the two right auxiliary light-emitting diodes 256B at their respective light emission angles (e.g., projecting a larger and brighter production warning icon 220C). The holographic pattern 264B does not diffract light of different wavelengths (green) or light at different angles (regardless of color). Alternatively, one or both of the holographic layers can contain one or more optically transparent regions, such as... Figure 3 The transparent window 368A of the main holographic panel 362A in the middle lacks a holographic pattern and overlaps with one or more of the holographic patterns of the adjacent holographic panels, which enables a brighter projected icon.

[0033] The holographic patterns selected for recording can be optically aligned with each other to combine their diffracted light, thereby producing icons of different wavelengths. As mentioned above, Figure 3 The leftmost main holographic icon 364A can only diffract the (green) light wavelength emitted by the leftmost main light-emitting diode 356A at its corresponding light emission angle, and Figure 3The leftmost auxiliary holographic icon 364B can only diffract the (red) light wavelength emitted by the leftmost auxiliary light-emitting diode 356B at its corresponding emission angle. However, Figure 3 The two leftmost holographic patterns 364A and 364B are optically aligned, for example, with an auxiliary icon 364B inserted between the main icon 364A and the two paired light-emitting diodes 356A and 356B, such that a reference beam emitted from it passes through both the leftmost holographic patterns 364A and 364B. In doing so, the light diffracted by these optically overlapping holographic patterns 364A and 364B combines to emit a magnified alarm icon 320A with a new (yellow) light wavelength different from the wavelengths of the two paired light-emitting diodes 356A and 356B.

[0034] An accompanying advantage of the disclosed holographic projection display system over existing RLAD devices is the ability to display complex icons and text, not just basic geometric shapes (e.g., reflections of flashlights in shapes such as dots, triangles, octagons, etc.). Accompanying advantages of the disclosed holographic projection display system over existing HUD devices may include reduced component costs and packaging space. Current vendor solutions using masking methods to provide static alarms have low light efficiency; the disclosed holographic projection display system achieves increased light efficiency and thus can provide enhanced icon brightness (e.g., at least about 4800 nits). The use of angle and wavelength multiplexing of the hologram can enable the disclosed holographic projection display system to implement multiple alarms. Multiple alarms can also be implemented by partitioning the HOE with separate light sources.

[0035] Next reference Figure 4 The flowchart, in accordance with various aspects of this disclosure, describes in general 400 places the method for operating a holographic RLAD device (such as... Figure 2 and Figure 3 The display systems of 250 and 350) are used in motor vehicles (such as Figure 1 Improved methods or control protocols for the in-cabin display system of automobiles (10). Figure 4 Some or all of the operations shown and further described in detail below can represent algorithms corresponding to non-transitory processor-executable instructions stored in, for example, main memory or secondary memory or remote memory (e.g., resident vehicle memory devices and / or remote cloud computing service databases). These instructions can be generated, for example, by a microprocessor, central controller, dedicated control module, logic circuit or other module or device or network of controller / module / device (e.g., Figure 1The ECU 38 of the vehicle (and / or a remote server-type cloud computing terminal) is used to perform any or all of the functions described above and below associated with the disclosed concept. It should be understood that the execution order of the illustrated operation boxes can be changed, additional operation boxes can be added, and some operations described herein can be modified, combined, or eliminated.

[0036] Method 400 in Figure 4 The start terminal block 401 begins with processor-executable instructions stored in memory for initializing the holographic projection display control protocol for the motor vehicle. This routine can be initialized in real-time, near real-time, continuously, systematically, intermittently, and / or at predefined time intervals (e.g., every 10 or 100 milliseconds) during operation of the motor vehicle 10. Alternatively, terminal block 401 can be initialized in response to user command prompts (e.g., via telematics input controls 28, 30), vehicle controller prompts (e.g., from ECU 38), or broadcast prompts received from a centralized back-end (BO) vehicle service system (e.g., from a cloud host service). In one example, method 400 can be automatically initialized in response to a key-on event, in which the driver of vehicle 10 presses the ignition button and shifts vehicle 10 to drive (D) or low gear (L1 / L2) sequentially. Figure 4 When some or all of the control operations presented in the method are interrupted, method 400 may proceed to the end terminal box 417 and temporarily terminate, or alternatively, it may cycle back to terminal box 401 and run in a continuous loop (e.g., until vehicle 10 is switched back to park (P) and / or off).

[0037] Proceeding from terminal box 401 to object detection process box 403, method 400 uses any one or more of a networked array of onboard sensing devices (e.g., cameras, radar arrays, lidar detectors, capacitive sensors, etc.) to detect target objects, such as vehicles, pedestrians, road obstacles, hazards, or animals in front of vehicle 10. In response to the detection of a target object, method 400 automatically executes object recognition process box 405 to classify and track the detected object. Thereafter, method 400 proceeds to threshold distance decision box 407 to determine whether the target distance to the target object is less than a predefined threshold distance (e.g., 100 feet for pedestrians or 30 feet for vehicles) to trigger an alarm for that type of target object. If not (box 407 = No), then method 400 may loop back to process box 403 and continue scanning for oncoming target objects.

[0038] When it is determined that the target distance to the target object is less than the threshold alarm distance (box 407 = Yes), method 400 may responsively execute threshold speed decision box 409 to determine whether the current vehicle speed of the primary vehicle meets or exceeds a predefined threshold alarm speed (e.g., ≥25 miles per hour (MPH)) to trigger the alarm. If not (box 409 = No), then method 400 may loop back to process box 405 and continue tracking the detected target object. When it is determined that the current speed of the primary vehicle is equal to or greater than the threshold alarm speed (box 409 = Yes), method 400 may responsively execute holographic alarm process box 411 and activate the holographic projection display system (e.g., Figure 1 The RLAD device 150 includes one or more corresponding LEDs that are illuminated and associated with a holographic alarm icon corresponding to a detected target object.

[0039] After activating the holographic projection display system, method 400 can proceed to the Continuing Hazard Decision box 413 to determine whether the detected target object is no longer a potential hazard. For example, method 400 can determine whether the speed of the main vehicle has decreased below a threshold alarm speed and / or whether the target distance to the target object is now greater than the threshold alarm distance and / or the target object is no longer detected. When it is determined that the target object continues to be a potential hazard (box 413 = Yes), method 400 can cycle back to process box 411 and continue displaying the holographic alarm icon corresponding to the detected target object (which can then be enlarged, brightened, flashed, or accompanied by an audible or tactile alarm). When the target object is no longer a potential hazard (box 413 = Yes), method 400 can responsively execute the Disable Holographic Alarm process box 415 and deactivate one or more LEDs corresponding to the holographic alarm icon of the detected target object. Thereafter, method 400 can cycle back to processing box 403, or it can proceed to terminal box 417 and temporarily terminate.

[0040] To create projected warning icons with colors different from the individual light-emitting elements (e.g., yellow icons from green and red LEDs), the desired warning icon patterns are recorded separately in each HOE film assigned to each layer. The film layers are laminated together, the recorded icon patterns are optically overlapped, and each layer is illuminated with a corresponding reconstructed beam identical to the reference beam. It is conceivable that the projected icons can be configured as a simulated display of speeds, such as a row of horizontally aligned blocks, each block corresponding to a specific vehicle speed (e.g., leftmost block = 5 mph, second from left = 10 mph, third from left = 15 mph, etc.). As another example implementation, the projected icons can be configured as a simulated display of increments from a set speed (e.g., leftmost block = +1 to 5 mph, second from left = +6 to 10 mph, third from left = +11 to 15 mph, etc.). In another exemplary implementation, the projected icons can be configured as a simulated display of fuel levels (e.g., the leftmost block = 2 gallons remaining, the second block from the left = 4 gallons remaining, the third block from the left = 4 gallons remaining, etc.) or a battery level alert 220D (e.g., the leftmost block = 60 miles (mi) range (R) remaining, the second block from the left = 100 mi R remaining, the third block from the left = 150 mi R remaining, etc.).

[0041] In some embodiments, aspects of this disclosure may be implemented by a computer-executable program of instructions, such as a program module, typically referred to as a software application or application executed by any of the controllers or controller variants described herein. In non-limiting examples, the software may include routines, programs, objects, components, and data structures that perform specific tasks or implement specific data types. The software may form an interface that allows a computer to respond to an input source. The software may also cooperate with other code segments to initiate various tasks in response to data received in conjunction with a source of received data. The software may be stored on any of a variety of storage media, such as CD-ROM, magnetic disk, and semiconductor memory (e.g., various types of RAM or ROM).

[0042] Furthermore, aspects of this disclosure can be practiced with various computer systems and computer network configurations, including multiprocessor systems, microprocessor-based or programmable consumer electronics, minicomputers, mainframes, etc. Additionally, aspects of this disclosure can be practiced in distributed computing environments, where tasks are performed by resident and remote processing devices linked via communication networks. In distributed computing environments, program modules can reside on both local and remote computer storage media, including memory storage devices. Therefore, aspects of this disclosure can be implemented in combination with various hardware, software, or combinations thereof in computer systems or other processing systems.

[0043] Any method described herein may include machine-readable instructions for execution by: (a) a processor, (b) a controller, and / or (c) any other suitable processing device. Any algorithm, software, control logic, protocol, or method disclosed herein may be implemented as software stored on a tangible medium such as, for example, flash memory, solid-state drive (SSD) memory, hard disk drive (HDD) memory, CD-ROM, digital versatile disc (DVD), or other storage devices. The entire algorithm, control logic, protocol, or method and / or portions thereof may alternatively be executed by a device other than a controller and / or implemented in firmware or dedicated hardware (e.g., implemented by application-specific integrated circuits (ASICs), programmable logic devices (PLDs), field-programmable logic devices (FPLDs), discrete logic, etc.). Furthermore, while a particular algorithm may be described with reference to the flowcharts and / or workflow diagrams depicted herein, many other methods for implementing the example machine-readable instructions may be used alternatively.

[0044] Various aspects of this disclosure have been described in detail with reference to the illustrated embodiments; however, those skilled in the art will recognize that many modifications can be made thereto without departing from the scope of this disclosure. This disclosure is not limited to the precise construction and composition disclosed herein; any and all modifications, alterations, and variations apparent from the foregoing description are within the scope of this disclosure as defined by the appended claims. Furthermore, this concept expressly includes any and all combinations and sub-combinations of the foregoing elements and features.

Claims

1. A holographic projection display system for projecting an image onto a reflective surface, the holographic projection display system comprising: a cluster of illumination elements arranged in a predefined pattern, the cluster of illumination elements comprising: a plurality of first light emitting diodes having a first light wavelength and each first light emitting diode having a respective first emission angle toward the reflective surface, and a plurality of second light emitting diodes having a second light wavelength and each second light emitting diode having a respective second emission angle toward the reflective surface; and a multi-layer holographic optical element (HOE) assembly attached to the cluster of illumination elements in front of the plurality of first and second light emitting diodes, the multi-layer HOE assembly comprising: a first holographic panel having recorded therein a plurality of first holographic patterns, each first holographic pattern being optically configured to diffract the first light wavelength of the first light emitting diode emitted at one or more of the respective first emission angles, and a second holographic panel attached to the first holographic panel, the second holographic panel having recorded therein a plurality of second holographic patterns, each second holographic pattern being optically configured to diffract the second light wavelength of the second light emitting diode emitted at one or more of the respective second emission angles.

2. The holographic projection display system of claim 1, wherein one of the first holographic patterns diffracts only the first light wavelength emitted at the respective first emission angle of a respective one of the first light emitting diodes, and one of the second holographic patterns diffracts only the second light wavelength emitted at the respective second emission angle of a respective one of the second light emitting diodes.

3. The holographic projection display system of claim 1, wherein the second holographic panel includes an optically transparent region that is free of any holographic patterns and overlaps one of the first holographic patterns of the first holographic panel.

4. The holographic projection display system of claim 1, wherein one of the first holographic patterns diffracts only the first light wavelength emitted at the respective first emission angles of two of the first light emitting diodes, and one of the second holographic patterns diffracts only the second light wavelength emitted at the respective second emission angles of two of the second light emitting diodes.

5. The holographic projection display system of claim 4, wherein the respective first emission angles of the two of the first light emitting diodes are different from each other, and the respective second emission angles of the two of the second light emitting diodes are different from each other.

6. The holographic projection display system of claim 1, wherein: one of the first holographic patterns diffracts only the first light wavelength emitted at the respective first emission angle of a respective one of the first light emitting diodes, one of the second holographic patterns diffracts only the second light wavelength emitted at the respective second emission angle of a respective one of the second light emitting diodes, and one of the first holographic patterns overlaps one of the second holographic patterns such that light diffracted by the overlapping holographic patterns combine to emit an image of a third light wavelength different from the first and second wavelengths.

7. The holographic projection display system of claim 5, wherein a respective first emission angle of a respective one of the first light emitting diodes is different from a respective second emission angle of a respective one of the second light emitting diodes.

8. The holographic projection display system of claim 1, further comprising an optically transparent adhesive layer mounting the first holographic panel to the second holographic panel.

9. The holographic projection display system of claim 1, further comprising: a plurality of first light prisms or reflectors, each first light prism or reflector located proximate a respective one of the first light emitting diodes and configured to direct a first reference light beam emitted therefrom at a respective first emission angle; and a plurality of second light prisms or reflectors, each second light prism or reflector located proximate a respective one of the second light emitting diodes and configured to direct a second reference light beam emitted therefrom at a respective second emission angle.

10. The holographic projection display system of claim 1, wherein the predefined pattern comprises a plurality of first and second light emitting diodes mounted in a fixed light array having a single row or multiple rows of diodes. ​

Images