A vibrating micro-prism waveguide display system

Abstract

The present invention relates to a vibrating micro-prism waveguide display system, comprising a light source module, a collimating eyepiece, a waveguide element, and a vibration device; the waveguide element comprises an optical waveguide lens, a coupling input optical element, and a coupling output optical element, wherein the coupling input optical element is embedded inside the optical waveguide lens, and the coupling output optical element is located on the surface of the optical waveguide lens; the light source module is used to provide an input light beam; the collimating eyepiece is used to change the width and direction of the input light beam; the waveguide element is used to achieve pupil expansion after the light beam is fully reflected; and the vibration device is used to control the waveguide element to continuously vibrate back and forth along the propagation direction of the light beam. The present invention uses a micro-prism array as a coupling output optical element to construct a waveguide display system, and builds a complete geometric waveguide head-up display system, providing a theoretical reference for a high-performance, low-cost vehicle-mounted HUD solution, and generating significant social and economic benefits in the airborne and vehicle-mounted fields.

Description

Technical Field

[0001] The present invention relates to the field of optical technology, and in particular to a vibrating micro-prism waveguide display system. Background Art

[0002] The Head-Up Display (HUD) system is a type of airborne or vehicle-mounted instrument equipment with augmented reality functions. It projects driving parameters, navigation information, etc. in the form of images and characters directly in front of the driver through an optical system, allowing the driver to obtain various information from the aircraft and car while observing the driving environment.

[0003] With the rapid development of the automobile industry, the requirements for the integration of vehicle internal systems have been greatly increased, and the requirements for lightweight, miniaturized and display effects of HUD systems are getting higher and higher. The traditional vehicle-mounted HUD system is mainly designed according to the off-axis catadioptric structure. The image displayed by the image source is first projected onto the windshield or auxiliary display screen through the off-axis reflector system, and then reflected into the human eye. If this design scheme is used to achieve a large eye movement range and a large field of view, the volume of the reflector and the overall volume and weight of the system will be very large, and the system cannot be miniaturized and lightweight, and the vehicle cannot provide enough assembly space. Applying optical waveguide technology to the vehicle-mounted head-up display system can effectively reduce the volume of the vehicle-mounted head-up display system by compressing the optical path propagation.

[0004] Waveguide display systems are divided into geometric waveguides and diffraction waveguides. The diffraction waveguide HUD system uses a grating with a period of several hundred nanometers as a coupling output optical element. Since the period of the grating is close to the size of the wavelength of light, a diffraction effect will occur when the light beam passes through the grating, generating multi-order diffraction light beams with different diffraction angles. Light beams of different wavelengths will produce different diffraction orders, so the diffraction waveguide is selective to the wavelength of light and can only realize monochrome imaging applications.

[0005] Because the geometric waveguide HUD system can achieve system miniaturization and full-color display, it has received widespread attention in the application market. Waveguide display technology abandons the complex optical system and large-size reflectors required in traditional design solutions, and completes image transmission and final imaging display through flat waveguides and embedded coupled input optical elements and coupled output optical elements. It has important application potential in achieving lightweight and miniaturized HUD systems. At the same time, it has no selectivity for the wavelength of light and is easy to achieve full-color display.

[0006] Geometric waveguides can be divided into transflective film waveguides and microprism waveguides according to the different coupling output optical elements. Among them, the transflective film waveguide uses multiple partially reflective mirrors (Partially Reflective Mirror, PRM) to control the coupling output of the light beam. Due to the reflectivity gradient change of multiple partial reflectors, the illumination uniformity during imaging is poor; at the same time, each partial reflector must be embedded in the waveguide plate, the processing cost is high and it is difficult to produce in batches. The microprism waveguide controls the coupling output of the light beam through a microprism array, where the microprism array is on the surface of the waveguide plate. Since the microprism array is easy to mass produce, the microprism waveguide can reduce the cost of mass production; at the same time, by controlling the arrangement density of prisms in the microprism array, the illumination uniformity during imaging can be effectively improved. However, when the microprisms are arranged too loosely, image intervals will appear during imaging. Summary of the invention

[0007] In order to achieve the above-mentioned purpose and other advantages of the present invention, the purpose of the present invention is to provide a vibrating micro-prism waveguide display system, including a light source module, a collimating eyepiece, a waveguide element, and a vibrating device; the waveguide element includes an optical waveguide lens, a coupling input optical element, and a coupling output optical element, wherein the coupling input optical element is embedded in the optical waveguide lens, the coupling output optical element is located on the surface of the optical waveguide lens, and the coupling output optical element adopts a micro-prism array;

[0008] The light source module is used to provide an input light beam;

[0009] The collimating eyepiece is used to change the width and direction of the input light beam;

[0010] The waveguide element is used to achieve exit pupil expansion after the light beam is totally reflected;

[0011] The vibration device is used to control the waveguide element to continuously vibrate back and forth along the propagation direction of the light beam.

[0012] Furthermore, the characteristic size of each micro-prism structure in the micro-prism array is 0.5-2 mm.

[0013] Furthermore, the microprisms in the microprism array are arranged from sparse to dense along the light beam propagation direction.

[0014] Furthermore, the microprism array is divided into a plurality of microprism regions, and the reflectivity of the plurality of microprism regions increases gradiently along the propagation direction of the light beam.

[0015] Furthermore, the coupling-in optical element is a partial reflective mirror.

[0016] Furthermore, the inclination angle of the partial reflector is the same as the inclination angle of the microprisms in the microprism array.

[0017] Furthermore, the vibration device includes a shell, an electromagnet wound with a coil, and an electrode. The shell is used to install the waveguide element. The electromagnet is connected to the electrode. The electromagnet is used to drive the waveguide element to vibrate back and forth continuously along the propagation direction of the light beam through the shell.

[0018] Furthermore, the vibration frequency of the electromagnet in the vibration device is above 120 Hz after being energized.

[0019] Furthermore, the reflectivity calculation formula of the microprism area is:

[0020]

[0021] Wherein, i=0, 1, 2, ..., N-1; N is the total number of micro-prism regions; i is the i-th micro-prism region.

[0022] Furthermore, the reflectivity calculation formula of the partial reflector is:

[0023]

[0024] Among them, L T is the incident light width, L W is the width of the microprism area.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] The present invention uses microprism arrays as coupling output optical elements to construct waveguide display systems, studies the preparation methods of miniaturized, integrated and multifunctional micro-optical elements, and builds a complete geometric waveguide head-up display system, providing theoretical reference for high-performance, low-cost vehicle-mounted HUD solutions, and generating significant social and economic benefits in the airborne and vehicle-mounted fields.

[0027] The geometric optical waveguide uses a microprism array to achieve total reflection propagation of the light beam. The microprism array is composed of periodically arranged microprisms. By adjusting the density of the microprism arrangement, the reflectivity of the microprism array can be optimized, thereby improving the illumination uniformity of the waveguide display system.

[0028] In a micro-prismatic geometric optical waveguide, imaging intervals will occur when the micro-prisms are arranged too loosely. The present invention adds a left-right vibration device to the waveguide plate. Since the waveguide can continuously move left-right during imaging, the waveguide output light beam continuously moves left-right, thereby eliminating the image interval during imaging.

[0029] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the following is a detailed description of the preferred embodiments of the present invention in conjunction with the accompanying drawings. The specific implementation of the present invention is given in detail by the following embodiments and their accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0031] Figure 1 This is a working principle diagram of the vibrating micro-prism waveguide display system of Example 1;

[0032] Figure 2 Schematic diagram of reflectivity and uniformity of microprisms in Example 1;

[0033] Figure 3 It is a top view of the waveguide element and the vibration device of Example 1.

[0034] In the figure: 1. light source module; 2. collimating eyepiece; 3. waveguide element; 31. optical waveguide lens; 32. coupling input optical element; 33. coupling output optical element; 4. vibration device; 41. shell; 42. electromagnet; 43. coil; 44. electrode; 5. pupil box. DETAILED DESCRIPTION

[0035] The present invention is further described below in conjunction with the accompanying drawings and specific implementation methods. It should be noted that, under the premise of no conflict, the various embodiments or technical features described below can be arbitrarily combined to form a new embodiment.

[0036] Example 1

[0037] A vibrating microprism waveguide display system, such as Figure 1 , Figure 3 As shown, it includes a light source module 1, a collimating eyepiece 2, a waveguide element 3, and a vibration device 4; the waveguide element 3 includes a light waveguide lens 31, a coupling input optical element 32, and a coupling output optical element 33, the coupling input optical element 32 is embedded in the light waveguide lens 31, and the coupling output optical element 33 is located on the surface of the light waveguide lens 31, and a microprism array can be embossed on the surface of the light waveguide lens 31;

[0038] The light source module 1 is used to provide an input light beam;

[0039] The collimating eyepiece 2 is used to change the width and direction of the input light beam;

[0040] The waveguide element 3 is used to realize the exit pupil expansion after the light beam is totally reflected;

[0041] The vibration device 4 is used to control the waveguide element 3 to continuously vibrate back and forth along the propagation direction of the light beam. In this embodiment, the vibration device 4 controls the waveguide element 3 to continuously move left and right.

[0042] In this embodiment, the coupling output optical element 33 is a microprism array, and the characteristic size of each microprism structure in the microprism array is 0.5-2 mm. The microprisms in the microprism array are arranged from sparse to dense along the propagation direction of the light beam. The microprism array is divided into a plurality of microprism areas, and the reflectivity of the plurality of microprism areas increases along the propagation direction of the light beam, thereby ensuring a high uniformity of illumination during imaging.

[0043] The micro-prism waveguide uses a micro-prism array as the coupling output optical element 33. The advantage is that the micro-prism array is easy to process and produce in batches, and the reflectivity of different areas can be changed by adjusting the density of the micro-prism arrangement, thereby improving the energy uniformity of the expanded light beam. Figure 2 As shown, Figure 2 (a) The reflectivity of the microprism array remains unchanged. Figure 2 In (b), the microprism array is divided into multiple regions with different reflectivity, namely, microprism regions. The reflectivity calculation formula of the microprism region is:

[0044]

[0045] Wherein, i=0, 1, 2, ..., N-1; N is the total number of micro-prism regions; i is the i-th micro-prism region.

[0046] The waveguide element 3 uses a micro-prism array to achieve total reflection propagation of the light beam. The micro-prism array of this embodiment is composed of a periodic arrangement of triangular prisms. The reflectivity of the micro-prism array can be optimized by adjusting the density of the triangular prism arrangement, thereby improving the illumination uniformity of the waveguide display system. It should be noted that the coupling output optical element 33 is not limited to a triangular pyramid structure, and the coupling output optical element 33 can be any microstructure that can reflect the light beam.

[0047] In order to ensure that the reflectivity of each area of ​​the microprism array is distributed as designed above, the spacing of the prisms in some areas will be larger, resulting in the spacing of the imaging beam exceeding the pupil diameter of the human eye (4mm), which will cause image spacing during imaging. When the triangular prisms are arranged too loosely, imaging spacing will occur. By adding a vibration device 4 to the waveguide element 3, the waveguide element 3 is continuously vibrated left and right during operation, so that the output beam of the waveguide element 3 continuously moves left and right, thereby eliminating the imaging spacing.

[0048] In this embodiment, the coupling input optical element 32 is a partial reflector, which reflects the light beam into the waveguide element 3 on the one hand, and transmits a part of the light beam on the other hand, and participates in the expansion of the light beam, thereby reducing the volume of the waveguide element 3. The inclination angle of the partial reflector is the same as the inclination angle of the microprism in the microprism array, ensuring that the expanded light beam is directly above the waveguide. The reflectivity calculation formula of the partial reflector is:

[0049]

[0050] Among them, L T is the incident light width, L W is the width of the microprism area.

[0051] like Figure 3 As shown, the vibration device 4 includes a shell 41, an electromagnet 42 wound with a coil 43, and an electrode 44. The shell 41 is used to install the waveguide element 3, that is, the vibration device 4 is connected to the waveguide element 3 through the shell 41, and the electromagnet 42 is connected to the electrode 44. The electromagnet 42 is used to drive the waveguide element 3 to vibrate continuously back and forth along the propagation direction of the light beam through the shell 41. After power is turned on, the electromagnet 42 drives the shell 41 to vibrate continuously left and right at a frequency of 120Hz, thereby driving the waveguide element 3 to output the image to vibrate continuously left and right, which can eliminate the image interval during imaging. It should be noted that the vibration frequency of the electromagnet 42 in the vibration device 4 is 120Hz or above after power is turned on, so that the waveguide element 3 moves quickly without causing visual impact. It should be noted that the vibration device 4 is not limited to being driven by the electromagnet 42, and other driving devices such as motors can also be used.

[0052] The light beam emitted by the light source module 1 is collimated by the collimating eyepiece 2 and then enters the waveguide element 3. When passing through the partial reflector (PRM), part of the light is transmitted out and participates in the exit pupil expansion, which also reduces the system volume to a certain extent; the other part of the light continues to propagate in the waveguide element 3 by total reflection. In the microprism area, the light beam propagating to the hypotenuse of the prism is reflected out of the waveguide, and the other light beams continue to propagate backward, thereby realizing the exit pupil expansion. The area above the waveguide element 3 where all field angle light beams can be observed is the pupil box 5 (eyebox).

[0053] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0054] The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referenced to each other, and each embodiment focuses on the differences from other embodiments.

[0055] The above are only embodiments of this specification and are not intended to limit one or more embodiments of this specification. For those skilled in the art, one or more embodiments of this specification may have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of one or more embodiments of this specification shall be included in the scope of the claims of one or more embodiments of this specification.

Claims

1. A vibrating microprism waveguide display system, characterized in that: It includes a light source module, a collimating eyepiece, a waveguide element, and a vibration device; the waveguide element includes a light waveguide lens, a coupling input optical element, and a coupling output optical element, the coupling input optical element is embedded in the light waveguide lens, the coupling output optical element is located on the surface of the light waveguide lens, and the coupling output optical element adopts a micro prism array; The light source module is used to provide an input light beam; The collimating eyepiece is used to change the width and direction of the input light beam; The waveguide element is used to achieve exit pupil expansion after the light beam is totally reflected; The vibration device is used to control the waveguide element to continuously vibrate back and forth along the propagation direction of the light beam, and the vibration frequency is above 120 Hz.

2. A vibrating microprism waveguide display system as claimed in claim 1, characterized in that: The characteristic size of each micro-prism structure in the micro-prism array is 0.5-2 mm.

3. A vibrating microprism waveguide display system as claimed in claim 1, characterized in that: The microprisms in the microprism array are arranged from sparse to dense along the propagation direction of the light beam.

4. A vibrating microprism waveguide display system as claimed in claim 3, characterized in that: The micro-prism array is divided into a plurality of micro-prism regions, and the reflectivity of the plurality of micro-prism regions increases gradiently along the propagation direction of the light beam.

5. A vibrating microprism waveguide display system as claimed in claim 1, characterized in that: The coupling-in optical element is a partial reflective mirror.

6. A vibrating microprism waveguide display system as claimed in claim 5, characterized in that: The inclination angle of the partial reflector is the same as the inclination angle of the microprisms in the microprism array.

7. A vibrating microprism waveguide display system as claimed in claim 1, characterized in that: The vibration device includes a shell, an electromagnet wound with a coil, and an electrode. The shell is used to install the waveguide element. The electromagnet is connected to the electrode. The electromagnet is used to drive the waveguide element to vibrate back and forth continuously along the propagation direction of the light beam through the shell.

8. A vibrating microprism waveguide display system as claimed in claim 4, characterized in that: The reflectivity calculation formula of the microprism area is: ， Where, i = 0, 1, 2, …, N−1; N is the total number of microprism regions; i is the i-th microprism region.

9. A vibrating microprismatic waveguide display system as claimed in claim 8, characterized in that: The reflectivity calculation formula of the partial reflector is: ， in, is the incident light width, is the width of the microprism area.

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