Holographic display system for motor vehicles with conjugate image removal

Abstract

A holographic display system for a motor vehicle includes a coherent light source for producing coherent light and a spatial light modulator (SLM) having a two-dimensional array of pixels that are holographically encoded for modulating the phase of the coherent light. The SLM produces a first diffracted light beam associated with a primary image and a second diffracted light beam associated with a conjugate image, where the first and second diffracted light beams are angularly separated from each other at a first angle. The system also includes an optical component for angularly separating the first and second diffracted light beams from each other at a second angle that is greater than the first angle. The system also includes a display surface that receives the first diffracted light beam from the optical component for displaying the primary image, the display surface being free of the second diffracted light beam.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to holographic display systems for motor vehicles, and more particularly, to holographic display systems that angularly separate a primary image from a conjugate image to display only the primary image on a display plane and improve overall image quality. BACKGROUND

[0002] Automotive manufacturers are continually researching ways to improve augmented reality (AR) head-up display systems (HUDs) with spatial light modulators (SLMs). In augmented reality (AR) head-up display systems (HUDs), the phase modulation capability of the SLM is not equal to 2π, and the presence of a conjugate image along with a primary image in the same field of view reduces image quality. Modern luxury or premium automobiles can include an AR HUD with a spatial light modulator (SLM) that removes the conjugate image by finely tuning the red, green, and blue SLMs and providing 2π phase modulation for each color. However, when compared to SLMs that are not modified to provide 2π phase modulation, SLMs that modulate red lasers require a thicker cell gap or a higher index of refraction liquid crystal, which results in a longer reaction time.

[0003] Therefore, while existing holographic display systems achieve their intended purpose, new or improved holographic display systems are needed to address these issues. SUMMARY

[0004] According to several aspects of the present disclosure, a holographic display system for a motor vehicle is provided. The system includes a coherent light source that generates coherent light. The system also includes a spatial light modulator (SLM) with a two-dimensional array of pixels. The two-dimensional array of pixels is holographically encoded to modulate a phase of the coherent light and generate a first diffracted beam associated with a primary image and a second diffracted beam associated with a conjugate image, the first and second diffracted beams angularly separated from each other at a first angle. The system further includes optical components to transmit at least one of the first and second diffracted beams, and the first and second diffracted beams are angularly separated from each other at a second angle that is greater than the first angle. The system also includes a display surface disposed relative to the optical components to receive the diffracted beams from the optical components and display the primary image, the display surface being free of the second diffracted beam. The system also includes a computer having a processor coupled to the coherent light source and the SLM. The computer further has a memory containing instructions that program the processor to control the two-dimensional array of pixels of the SLM to generate the first and second diffracted beams.

[0005] In one aspect, the SLM can generate a phase shift in a range of 0-2π, the actual range of the phase shift not being equal to 2π.

[0006] In another aspect, the coherent light source is a laser.

[0007] On the other hand, this SLM is a liquid crystal on silicon (LCoS) SLM.

[0008] On the other hand, the optical component is a diffraction grating for diffracting at least one of the first and second diffraction beams.

[0009] On the other hand, the optical component is a refracting prism used to refract at least one of the first and second diffracted beams.

[0010] According to several aspects of this disclosure, a motor vehicle includes a main body defining a passenger compartment. The motor vehicle also includes a plurality of reflective surfaces surrounding the passenger compartment, the reflective surfaces including at least one of a mirror, a windshield, a rear windshield, a sunroof, and a plurality of side windows surrounding the passenger compartment. The motor vehicle also includes a holographic display system coupled to the main body. The system includes a coherent light source for generating coherent light. The system also includes a spatial light modulator (SLM) with a two-dimensional pixel array. The two-dimensional pixel array is holographically encoded to modulate the phase of the coherent light and generate a first diffracted beam associated with a main image and a second diffracted beam associated with a conjugate image, the first and second diffracted beams being angularly separated from each other at a first angle. The system also includes optical components for transmitting at least one of the first and second diffracted beams, the first and second diffracted beams being angularly separated from each other at a second angle larger than the first angle. The system also includes a display surface disposed relative to the optical components to receive the diffracted beams from the optical components and display the main image, the display surface having no second diffracted beam. The system also includes a computer having a processor coupled to the coherent light source and the SLM. The computer further has a memory containing instructions that cause the processor to be programmed to control the two-dimensional pixel array of the SLM to generate the first and second diffracted beams.

[0011] On the one hand, the display surface is part of at least one of the reflector, the windshield, the rear windshield, the sunroof, and the side window.

[0012] On the other hand, the system also includes a combination glass installed in the cabin, and the display surface is part of the combination glass.

[0013] On the other hand, this SLM can produce a phase shift in the range of 0-2π, although the actual range of the phase shift is not equal to 2π.

[0014] On the other hand, the coherent light source is a laser.

[0015] On the other hand, this SLM is a liquid crystal on silicon (LCoS) SLM.

[0016] On the other hand, the optical component is a diffraction grating for diffracting at least one of the first or second diffracted beams.

[0017] On the other hand, the optical component is a refracting prism used to refract at least one of the first or second diffracted beams.

[0018] According to several aspects of this disclosure, a method for operating a holographic display system for a motor vehicle is provided. The system includes a coherent light source, a spatial light modulator (SLM) having a two-dimensional pixel array, the SLM having optical components, a display plane, and a computer having a processor and memory. The method includes the coherent light source generating coherent light. The method further includes the spatial light modulator modulating the phase of the coherent light, which generates a first diffracted beam and a second diffracted beam, the first diffracted beam being associated with a main image and the second diffracted beam being associated with a conjugate image, wherein the first and second diffracted beams are angularly separated from each other at a first angle. The method further includes the optical components angularly separating the first and second diffracted beams from each other at a second angle greater than the first angle. The method further includes the processor controlling the two-dimensional pixel array of the SLM to generate the first and second diffracted beams.

[0019] On the one hand, the method also includes the phase shift of the coherent light generated by the SLM, the actual range of which is not equal to 2π.

[0020] On the other hand, the method also includes a laser that generates the coherent light beam.

[0021] On the other hand, the method also includes using a liquid crystal on silicon (LCoS) SLM to modulate the phase of the coherent light to generate first and second diffracted beams.

[0022] On the other hand, the method also includes diffraction of at least one of the first or second diffraction beams by a diffraction grating.

[0023] On the other hand, the method also includes refracting at least one of the first or second diffracted beams using a refracting prism.

[0024] The further applicability will become apparent from the description provided herein. It should be understood that the descriptions and specific examples are for illustrative purposes only and are not intended to limit the scope of this disclosure. Attached Figure Description

[0025] The accompanying drawings described herein are for illustrative purposes only and are not intended to limit the scope of this disclosure.

[0026] Figure 1 This is a schematic diagram of an example of a motor vehicle equipped with a holographic display system.

[0027] Figure 2 yes Figure 1 The diagram shows a cabin layout of the system, illustrating an example of a system with a front windshield and display plane.

[0028] Figure 3 yes Figure 2 A schematic diagram of an example of the system shown illustrates a system including a diffraction grating that separates the first and second diffraction beams at an angle.

[0029] Figure 4 yes Figure 2 A schematic diagram of another example of the system shown illustrates a system including a refractive prism that angles to separate the first and second diffracted beams.

[0030] Figure 5 yes Figure 1 The schematic diagram of the passenger cabin of the motor vehicle shown illustrates another example of a system with a combined glass panel featuring a display plane.

[0031] Figure 6 It is one Figure 1 A flowchart illustrating an exemplary method of the holographic display system. Detailed Implementation

[0032] The following description is merely exemplary in nature and is not intended to limit this disclosure, its application, or its uses.

[0033] This disclosure describes an example of a motor vehicle having a holographic display system (system) 100, wherein, in order to display a main image only on a display surface, the holographic display system angularly separates a conjugate image from the main image. A non-limiting example of system 100 includes an augmented reality (AR) head-up display (HUD) system that can blend holographic display elements with other display elements or environmental features, such that a holographic image is presented in the physical world. To describe this non-limiting example in detail below, system 100 includes a spatial light modulator (SLM) 102 with a two-dimensional pixel matrix 104. System 100 also includes a computer for controlling the SLM 102 to display the main image and the conjugate image, which have an inherent angle between them, and the system also includes diffractive or refractive optics for amplifying the angular separation between the main image and the conjugate image. The system can be used as part of any land, sea, or air vehicle. In other non-limiting examples, the system can be used as part of a fixed or mobile power plant, robot, or platform. For the sake of consistency, the application of the system as an integral part of a motor vehicle will be described below, but this disclosure is not limited to this embodiment.

[0034] refer to Figure 1 An example of motor vehicle 106 includes a limited passenger cabin 110. Figure 2 The cabin 110 has a main body 108 and multiple reflective surfaces 112 surrounding the cabin 110. The reflective surfaces 112 may include at least one of a windshield 114, a rear windshield 116, a sunroof 118, and multiple side windows 120 surrounding the cabin 110.

[0035] like Figure 2 , 3 As shown, the motor vehicle 106 also includes a holographic display system 100 (system) coupled to the main body 108. System 100 includes a display surface 122. One non-limiting example of the display surface may be the entire portion of the windshield 114. In other non-limiting examples, the display surface 122 may be the rear windshield 116. Figure 1 ), sunroof 118, side window or other suitable part of a vehicle.

[0036] See again Figure 1 The system 100 also includes a coherent light source 124 for generating a coherent beam of light. A non-limiting example of the light source 124 may include a laser 126. Although in Figure 1 The image depicts a single laser 126, but it is anticipated that the system may include two or more lasers, such as separate red, green, and blue lasers.

[0037] System 100 also includes a spatial light modulator (SLM) 102 with a two-dimensional pixel array 104. In this non-limiting example, the SLM can produce a phase shift in the range of 0-2π, where the actual range of the phase shift is not equal to 2π. However, other instances of the SLM are contemplated to produce a phase shift equal to 2π. The two-dimensional pixel array 104 is holographically encoded to modulate the phase of coherent light and produces a first diffracted beam 128 associated with the main image and a second diffracted beam 130 associated with the conjugate image, wherein the first and second diffracted beams 128, 130 are angularly separated from each other by a first angle α. The SLM is a fast-switching high pixel density spatial light modulator (SLM) with driving circuitry to provide a high frame rate. The high frame rate can be a 60 Hz frame rate, at which the SLM displays a series of subframes in chronological order, and the human eye does not perceive flicker when viewing the entire field of view. However, it is contemplated that the frame rate can exceed or fall below 60 Hz. In one non-limiting example, the two-dimensional pixel array 104 is a liquid crystal on silicon (LCoS) two-dimensional pixel array 104, which provides diffraction phase elements to support holographic projection. In other examples, the spatial light modulator can be a MEMS shutter display or a DLP DMD array. The spatial light modulator can be independently controlled to form, transmit, or reflect different rays at high resolution.

[0038] like Figure 3As shown, system 100 also includes an optical component 132 for transmitting one of the first and second diffracted beams 128, 130 and separating the first and second diffracted beams 128, 130 at an angle of a second angle θ, which is smaller than the first angle α. The second angle θ and the inherent angular distance generated by the SLM 102 are angled apart from the second diffracted beam 130. A non-limiting example of the optical component 132 is a diffraction grating 134 for diffracting one of the first and second diffracted beams 128, 130. The diffraction grating 134 transmits and diffracts only the first diffracted beam 128, such that the first diffracted beam 128 is angled apart from the second diffracted beam 130 at the second angle θ, and the inherent angular distance generated by the SLM 102 is further extended. The diffraction grating 134 can be fabricated by holographic methods such as photopolymers, liquid crystal reactive monomers, or glass forming techniques that induce periodic refractive index modulation.

[0039] See again Figure 1 The system also includes a computer with a processor 138 coupled to the light source 124 and the SLM 102. The processor 138 can be used to calculate image data in real time and output it to the two-dimensional pixel array 104 in the SLM 102. The processor 138 may include processing circuitry, which may include application-specific integrated circuits (ASICs), electronic circuitry, and processors (shared, dedicated, or grouped). The computer 136 may also include a memory 140 for executing one or more software or firmware programs, combinational logic circuitry, and / or other suitable components that provide the aforementioned functionality. The processor 138 may include an input / output interface 142 for communicating with various components such as the input frame source 144 and the SLM 102. When the system 100 is integrated into a vehicle, the input frame source 144 may be a vehicle control unit, for example, to display instrument values, trip information, entertainment content, or other such image-based data.

[0040] For example, via a vehicle communication module, processor 138 can be communicatively coupled to more than one local processor, such as an electronic processor unit (ECU) or a similar unit included in vehicle 100, for monitoring and / or controlling various vehicle components. Processor 138 is typically configured to communicate on the vehicle communication module via an internal wired and / or wireless network, for example, via a bus in vehicle 106 (such as a controller area network (CAN) and / or other wired and / or wireless mechanisms). Through the vehicle communication module, processor 138 can transmit messages to and / or receive messages from various devices in vehicle 106 (e.g., vehicle sensors, actuators, vehicle components, human-machine interfaces (HMIs), etc.). Alternatively or additionally, where the processor comprises multiple devices, the vehicle communication network can be used for communication between the devices represented by computer 136 in this disclosure. Further, as described below, various processors and / or vehicle sensors can provide data to computer 136. Processor 138 can receive and analyze data from sensors substantially continuously and / or periodically. For example, in processor 138, based on data from lidar sensors, camera sensors, etc., object classification or recognition technologies can be further used to identify lane markings, objects such as vehicles, people, rocks, culverts, bicycles, motorcycles, etc., as well as the physical characteristics of various objects.

[0041] The memory 140 includes one or more forms of computer-readable medium and is used to store instructions executable by the processor 138 to perform various operations including those disclosed herein. The memory 140 also includes instructions to cause the processor 138 to be programmed to control the two-dimensional pixel array of the SLM 102 to modulate a coherent beam and generate first and second diffracted beams 128, 130.

[0042] refer to Figure 4 According to another example, the holographic display system 200 is similar to Figure 3 System 100, the same parts are identified by the same number plus 100. However, although Figure 3 System 100 includes an optical component 132 in the form of a diffraction grating 134, and system 200 includes an optical component in the form of a refractive prism 248, which transmits and refracts one of the first and second diffraction beams 228, 230.

[0043] refer to Figure 5 According to another example, the holographic display system 300 is similar to Figure 2 The system is 100, and the same parts are identified by the same number plus 200. However, although Figure 2System 100 includes a display surface 122 in the form of a windshield 114 facing the cabin surface, and system 300 includes a combination glass 346 separate from the windshield 314 and disposed in the cabin 310, and the display surface 322 is part of the combination glass 346.

[0044] refer to Figure 6 A method 400 is provided for operating a holographic display system 100 of a motor vehicle 106. Method 400 begins at block 402, whereby a processor generates a first actuation signal, and in response to receiving the first actuation signal from a processor 138, a light source 124 generates an coded beam. In this non-limiting example, a laser 126 generates a coherent beam. However, it is contemplated that the system may include two or more lasers, such as separate red, green, and blue lasers.

[0045] In block 404, processor 138 generates a second actuation signal for controlling the two-dimensional pixel array of SLM 102. In response to the second actuation signal received from processor 138, SLM 102 generates first and second diffracted beams 128 and 130. More specifically, SLM 102 is a liquid crystal on silicon (LsoS) SLM that modulates the phase of coherent light to generate a first diffracted beam 128 associated with the main image and a second diffracted beam 130 associated with the conjugate image, wherein the first and second diffracted beams 128 and 130 are angularly separated from each other by a first angle α. In this non-limiting example, SLM 102 generates a phase shift of the coherent light, the actual range of which is not equal to 2π. However, in other examples, the SLM produces a phase shift equal to 2π.

[0046] In block 406, optical component 132 separates the first and second diffracted beams 128 and 130 at an angle of a second angle θ greater than the first angle α. In a non-limiting example, optical component 132 is a diffraction grating 134 that diffracts at least one of the first and second diffracted beams 128 and 130. In another non-limiting example ( Figure 4 In the optical component 232, the optical component 232 is a refracting prism that refracts at least one of the first and second diffracted beams 228 and 230.

[0047] As described in this disclosure, computers and computing devices typically include computer-executable instructions, which can be executed by one or more computing devices such as those listed above. Computer-executable instructions can be compiled or interpreted from computer programs created using various programming languages ​​and / or technologies, including but not limited to JAVA, C, C++, MATLAB, SIMULINK, STATEFLOW, VISUAL BASIC, JAVA SCRIPT, PERL, HTML, TENSORFLOW, PYTORCH, KERAS, etc., individually or in combination. Some of these applications can be compiled and executed on virtual machines, such as JAVA VIRTUALMACHINE, DALVIK Virtual Machine, etc. Typically, a processor (e.g., a microprocessor) receives instructions from memory, computer-readable media, etc., and executes those instructions to perform one or more processes, including one or more processes described herein. Such instructions and other data can be stored and transferred using various computer-readable media. Files in computing devices are typically collections of data stored on computer-readable media, such as storage media, random access memory, etc.

[0048] Memory can include computer-readable media (also known as processor-readable media), which includes any non-transitory (e.g., tangible) medium involved in providing data (e.g., instructions) that can be read by a computer (e.g., a computer's processor). Such media can take many forms, including but not limited to non-volatile and volatile media. Non-volatile media can include, for example, optical discs or magnetic disks, and other persistent storage. Volatile media can include, for example, dynamic random access memory (DRAM), which typically constitutes main memory. Such instructions can be transmitted via one or more transmission media, including coaxial cables, copper wires, and optical fibers, including lines that constitute a system bus coupled to the processor of an ECU. Common forms of computer-readable media include, for example, floppy disks, floppy disks, hard disks, magnetic tape, any other magnetic media, CD-ROMs, DVDs, any other optical media, punched cards, paper tape, any other physical media with a perforated pattern, RAM, PROM, EPROM, FLASH EEPROM, any other memory chips or cassette tapes, or any other media that a computer can read.

[0049] The databases, data repositories, or other data stores described in this article can include various mechanisms for storing, accessing, and retrieving a wide range of data, including hierarchical databases, a set of files in a file system, application databases in proprietary formats, relational database management systems (RDBMS), and so on. Each such data store is typically contained on a computing device employing a computer operating system, such as one of those mentioned above, and can be accessed via a network in any or more ways. File systems are accessible through a computer operating system and can include files stored in various formats. In addition to languages ​​used for creating, storing, editing, and executing stored procedures (such as the PL / SQL language mentioned above), RDBMS typically also use Structured Query Language (SQL).

[0050] In some instances, system elements may be implemented as computer-readable instructions (e.g., software) on one or more computing devices (e.g., servers, personal computers, etc.) stored on an associated computer-readable medium (e.g., disks, storage, etc.). A computer program product may include instructions stored on a computer-readable medium for performing the functions described herein.

[0051] Regarding the media, processes, systems, methods, heuristics, etc., described herein, it should be understood that although the steps of these processes, etc., have been described as occurring in a certain ordered order, such processes can be practiced by performing the described steps in a different order than that described herein. It should also be understood that some steps may be performed simultaneously, other steps may be added, or some steps described herein may be omitted. In other words, the description of processes herein is provided for the purpose of illustrating certain embodiments and should in no way be construed as limiting the claims.

[0052] Therefore, it should be understood that the above description is intended to be illustrative rather than restrictive. Many embodiments and applications beyond the examples provided will be apparent to those skilled in the art upon reading the above description. The scope of the invention should not be determined by reference to the above description, but rather by reference to the appended claims and the full scope of their equivalents. Future developments are anticipated and intended in the art discussed herein, and the disclosed systems and methods will be incorporated into such future embodiments. In summary, it should be understood that modifications and variations are possible with respect to the invention, and it is limited only by the following claims.

[0053] All terms used in the claims are intended to be given the simple and common meaning as understood by those skilled in the art, unless expressly indicated otherwise herein. In particular, the use of singular articles such as “a,” “the,” “the,” etc., should be interpreted as listing one or more of the indicated elements, unless the claims set forth an express limitation to the contrary.

[0054] The description in this disclosure is exemplary in nature only, and any changes that do not depart from the spirit of this disclosure are intended to fall within its scope. Such changes should not be considered as departing from the scheme and scope of this disclosure.

Claims

1. A holographic display system for motor vehicles, the holographic display system comprising: A coherent light source is used to generate coherent light; A spatial light modulator includes a two-dimensional pixel array for modulating the phase of the coherent light and generating a first diffracted beam associated with a main image and a second diffracted beam associated with a conjugate image, wherein the first diffracted beam and the second diffracted beam are angularly separated from each other at a first angle. An optical component for transmitting at least one of the first diffracted beam and the second diffracted beam, and for separating the first diffracted beam and the second diffracted beam from each other at a second angle larger than the first angle. A display surface, disposed relative to the optical component, is configured to receive a first diffracted beam from the optical component and display the main image, wherein the display surface does not receive a second diffracted beam. Computers, including: The processor is coupled to the coherent light source and the spatial light modulator; and A memory containing instructions that allows the processor to be programmed to control the two-dimensional pixel array of the spatial light modulator to generate the first diffracted beam and the second diffracted beam; The optical component includes a diffraction grating for diffracting at least one of the first diffraction beam and the second diffraction beam; The spatial light modulator described therein is capable of generating a phase shift in the range of 0-2π, wherein the actual range of the phase shift is not equal to 2π.

2. The holographic display system according to claim 1, wherein the coherent light source is a laser.

3. The holographic display system according to claim 2, wherein the spatial light modulator is a silicon-based liquid crystal spatial light modulator.

4. A motor vehicle, comprising: Define the main body of the passenger cabin; A plurality of reflective surfaces surrounding the passenger cabin, the reflective surfaces including at least one of a reflector, a front windshield, a rear windshield, a sunroof, and a plurality of side windows surrounding the passenger cabin; and A holographic display system coupled to the main body includes: A coherent light source used to generate coherent light; A spatial light modulator includes a two-dimensional pixel array for modulating the phase of the coherent light and generating a first diffracted beam associated with a main image and a second diffracted beam associated with a conjugate image, wherein the first diffracted beam and the second diffracted beam are angularly separated from each other at a first angle. An optical component for transmitting at least one of the first diffracted beam and the second diffracted beam and separating the first diffracted beam and the second diffracted beam from each other at a second angle greater than the first angle. A display surface, disposed relative to the optical component, is configured to receive the first diffracted beam from the optical component and display the main image, wherein the display surface does not receive the second diffracted beam; and Computer, the computer comprising: The processor is coupled to the coherent light source and the spatial light modulator; and A memory containing instructions that allows the processor to be programmed to control a two-dimensional pixel array of the spatial light modulator to generate the first diffracted beam and the second diffracted beam. The optical component includes a diffraction grating for diffracting at least one of the first diffraction beam and the second diffraction beam; The spatial light modulator described therein is capable of generating a phase shift in the range of 0-2π, wherein the actual range of the phase shift is not equal to 2π.

5. The motor vehicle of claim 4, wherein the display surface comprises a portion of at least one of the front windshield, the rear windshield, the sunroof, and the side windows.

6. The motor vehicle according to claim 5, wherein the holographic display system further comprises a combination glass disposed within the passenger cabin, and the display surface is part of the combination glass.

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