Relay color combining device, micro-projection optical engine, method thereof and electronic device

Abstract

A relay color combining device, a micro-projection optical engine, its method and an electronic device. The relay color combining device is used to be assembled with an illumination component, a digital micromirror device and an imaging component to form a micro-projection optical engine. The relay color combining device has: a total reflection illumination optical path, which is adapted to be formed between the illumination component and the digital micromirror device, and is used to synthesize at least two monochromatic illumination lights from the illumination component into a combined color illumination light during the process of totally reflecting and transmitting the lights along the total reflection illumination optical path to the digital micromirror device, so as to be modulated into corresponding image light by the digital micromirror device; and a total reflection imaging optical path, which is adapted to be formed between the digital micromirror device and the imaging component, and is used to totally reflect and transmit the image light from the digital micromirror device along the total reflection imaging optical path to the imaging component, so as to be projected and imaged by the imaging component.

Description

Technical Field

[0001] The present invention relates to the technical field of micro-projection, and in particular to a relay color combining device, a micro-projection optical engine, a method thereof, and an electronic device. Background Art

[0002] In recent years, with the increasing maturity of micro-projector technology, micro-projectors have officially stepped out of the concept stage and gradually entered the stage of commercial practical application. More and more small portable projection media players, projection mobile phones, wearable display devices (such as AR glasses, etc.) have come into the market, making the application modes of micro-projection more diversified and the development prospects more promising.

[0003] Micro-projection display methods are usually developed based on projection display chips. Currently, the mainstream micro-projection display chips are TFI-LCD chips, LCoS chips, and DMD chips (i.e., digital micromirror devices). However, among these three display chips, the optical engine based on the TFI-LCD chip has low contrast, low light energy utilization rate, low brightness, and low resolution; the optical engine based on the LCoS chip has high contrast, high light energy utilization rate, high brightness, and low resolution; the optical engine based on the DMD chip has the highest contrast, high light energy utilization rate, high brightness, and high resolution. In addition, the digital micromirror device (DMD chip) also has advantages such as natural light illumination, no need for light of a specific polarization state, and no need for digital-to-analog conversion of signals, which makes the digital light processing (DLP) technology based on the digital micromirror device develop rapidly and be widely applied.

[0004] However, the main challenges currently faced by micro-projection optical engines still lie in the volume and weight of the optical engine. In particular, in order to achieve color projection, the existing optical engines based on DLP technology usually consist of a traditional optical path formed by components such as a light source, a collimating lens, a color combining system, a light homogenizing device, a relay lens, and an imaging lens. Among them, as a relatively independent unit device, the color combining system usually needs to be designed separately for parameters and then matched and connected between the collimating lens and the relay lens. In this way, although the design of the color combining system is relatively free, the introduction of such a color combining system makes the structure of the optical system of the entire optical engine not compact enough, resulting in a large volume and heavy weight of the existing optical engines based on DLP technology, which cannot meet the requirements of small volume and light weight of the optical engine for wearable display devices such as AR glasses and VR glasses, and even less can meet the development trend of miniaturization of electronic devices. Summary of the Invention

[0005] One advantage of the present invention is to provide a relay color combining device, a micro-projection optical engine, its method and an electronic device, which can meet the development trend of miniaturization and light weight of electronic devices, and is particularly suitable for applications in electronic devices such as AR glasses and VR glasses.

[0006] Another advantage of the present invention is to provide a relay color combining device, a micro-projection optical engine, its method and an electronic device. In one embodiment of the present invention, the micro-projection optical engine adopts an innovative optical path design, which is beneficial to meet the requirements of small volume, light weight, high brightness, high uniformity and high resolution.

[0007] Another advantage of the present invention is to provide a relay color combining device, a micro-projection optical engine, its method and an electronic device. In one embodiment of the present invention, the relay color combining device, as a compact device, has both relay and color combining functions, so that the relay color combining device can replace the independent color combining system and relay system in the traditional optical engine, which helps to reduce the volume and size of the micro-projection optical engine.

[0008] Another advantage of the present invention is to provide a relay color combining device, a micro-projection optical engine, its method and an electronic device. In one embodiment of the present invention, the micro-projection optical engine can utilize the difference in the critical total reflection angles of different color lights to flexibly nest the color combining system into the relay system to form a structurally compact relay color combining device, thereby effectively simplifying the system and reducing the volume of the optical engine.

[0009] Another advantage of the present invention is to provide a relay color combining device, a micro-projection optical engine, its method and an electronic device. In one embodiment of the present invention, the light source in the illumination component of the micro-projection optical engine adopts RGB three-in-one packaging and does not require an additional independent color combining device, which helps to greatly reduce the volume of the optical engine.

[0010] Another advantage of the present invention is to provide a relay color combining device, a micro-projection optical engine, its method and an electronic device. In one embodiment of the present invention, the micro-projection optical engine is innovative not only in the wearable field but also applicable to the traditional projection field and has excellent portability.

[0011] Another advantage of the present invention is to provide a relay color combining device, a micro-projection optical engine, its method and an electronic device. In one embodiment of the present invention, the micro-projection optical engine has a linear structure, which helps to reduce the volume of the micro-projection optical engine.

[0012] Another advantage of the present invention lies in providing a relay color combining device, a micro projection optical engine, and its method and electronic device. To achieve the above object, in the present invention, expensive materials or complex structures are not required. Therefore, the present invention successfully and effectively provides a solution that not only provides a simple relay color combining device, a micro projection optical engine, and its method and electronic device, but also increases the practicability and reliability of the relay color combining device, the micro projection optical engine, and its method and electronic device.

[0013] To achieve at least one of the above advantages or other advantages and objects, the present invention provides a relay color combining device for assembling with an illumination component, a digital micromirror device, and an imaging component into a micro projection optical engine. The relay color combining device has:

[0014] A total reflection illumination optical path, which is adapted to be formed between the illumination component and the digital micromirror device for synthesizing at least two monochromatic illumination lights from the illumination component into a combined color illumination light during the process of totally reflecting and transmitting the at least two monochromatic illumination lights along the total reflection illumination optical path to the digital micromirror device, so as to be modulated by the digital micromirror device into corresponding image light; and

[0015] A total reflection imaging optical path, which is adapted to be formed between the digital micromirror device and the imaging component for totally reflecting and transmitting the image light from the digital micromirror device along the total reflection imaging optical path to the imaging component, so as to be projected and imaged by the imaging component.

[0016] According to an embodiment of the present invention, the relay color combining device further has an incident surface corresponding to the illumination component, at least two monochromatic total reflection surfaces, a reflection surface, a display surface corresponding to the digital micromirror device, a combined color total reflection surface, and an exit surface corresponding to the imaging component. The at least two monochromatic total reflection surfaces and the combined color total reflection surface are arranged at intervals in sequence to respectively form at least two gaps between the at least two monochromatic total reflection surfaces and the combined color total reflection surface. The reflection surface and the display surface are arranged opposite to each other, and the incident surface and the exit surface are arranged opposite to each other. The total reflection illumination optical path first passes through the incident surface and then is bent by total reflection at the at least two monochromatic total reflection surfaces, and the total reflection imaging optical path first is bent by total reflection at the combined color total reflection surface and then passes through the exit surface.

[0017] According to an embodiment of the present invention, the relay color combining device includes a first prism, a second prism, and at least one optical element, wherein the first prism and the second prism are arranged with their inclined surfaces facing each other, and the at least one optical element is disposed therebetween at intervals, wherein a first inclined surface of the first prism and an optical surface of the at least one optical element respectively serve as the monochromatic total reflection surfaces, and a second inclined surface of the second prism serves as the color combining total reflection surface.

[0018] According to an embodiment of the present invention, the at least one optical element includes a first wedge prism and a second wedge prism, wherein the first wedge prism and the second wedge prism are sequentially stacked at intervals between the first inclined surface of the first prism and the second inclined surface of the second prism, so as to form a first gap between an upper surface of the first wedge prism and the first inclined surface of the first prism, a second gap between a lower surface of the first wedge prism and an upper surface of the second wedge prism, and a third gap between a lower surface of the second wedge prism and the second inclined surface of the second prism, wherein the first inclined surface of the first prism, the lower surface of the first wedge prism, and the lower surface of the second wedge prism sequentially serve as a first monochromatic total reflection surface, a second monochromatic total reflection surface, and a third monochromatic total reflection surface among the at least two monochromatic total reflection surfaces.

[0019] According to an embodiment of the present invention, the relay color combining device further includes a high reflection film, wherein the high reflection film is correspondingly disposed on the reflection surface of the relay color combining device for reflecting the at least two monochromatic illumination lights at the reflection surface.

[0020] According to an embodiment of the present invention, the at least one optical element includes a wedge prism, wherein the wedge prism is disposed at intervals between the first inclined surface of the first prism and the second inclined surface of the second prism, so as to form a first gap between an upper surface of the wedge prism and the first inclined surface of the first prism, and a second gap between a lower surface of the wedge prism and the second inclined surface of the second prism, wherein the first inclined surface of the first prism and the lower surface of the wedge prism respectively serve as a first monochromatic total reflection surface and a second monochromatic total reflection surface among the at least two monochromatic total reflection surfaces.

[0021] According to an embodiment of the present invention, the relay color combining device further includes a selective reflection film, wherein the selective reflection film is correspondingly disposed on the reflection surface of the relay color combining device for selectively reflecting a part of the at least two monochromatic illumination lights and transmitting another part of the at least two monochromatic illumination lights.

[0022] According to an embodiment of the present invention, the second prism is a right-angle prism, and the first prism is a curved-surface prism, wherein a curved side surface of the curved-surface prism serves as the reflecting surface of the relay color-combining device.

[0023] According to an embodiment of the present invention, the second prism is a right-angle prism, and the first prism is a triangular prism, wherein the relay color-combining device further includes a curved mirror, and the curved mirror is correspondingly disposed on a flat side surface of the triangular prism to provide the reflecting surface of the relay color-combining device through the curved surface of the curved mirror.

[0024] According to another aspect of the present invention, the present invention further provides a micro-projection optical engine, including:

[0025] An illumination assembly, wherein the illumination assembly is configured to provide at least two paths of monochromatic illumination light;

[0026] A digital micromirror device, wherein the digital micromirror device is configured to modulate the color-combined illumination light into corresponding image light;

[0027] An imaging assembly, wherein the imaging assembly is configured to project and image the image light; and

[0028] A relay color-combining device, wherein the relay color-combining device is disposed between the illumination assembly, the digital micromirror device, and the imaging assembly to form a total-reflection illumination optical path between the illumination assembly and the digital micromirror device through the relay color-combining device, and to form a total-reflection imaging optical path between the digital micromirror device and the imaging assembly through the relay color-combining device, wherein the relay color-combining device is configured to combine the at least two paths of monochromatic illumination light from the illumination assembly into one path of color-combined illumination light during the process of total-reflection transmission to the digital micromirror device along the total-reflection illumination optical path, and to transmit the image light from the digital micromirror device to the imaging assembly along the total-reflection imaging optical path.

[0029] According to an embodiment of the present invention, the relay color combining device has an incident surface corresponding to the lighting assembly, at least two monochromatic total reflection surfaces, a reflection surface, a display surface corresponding to the digital micromirror device, a color combining total reflection surface, and an exit surface corresponding to the imaging assembly, wherein the at least two monochromatic total reflection surfaces and the color combining total reflection surface are arranged at intervals in sequence to respectively form at least two gaps between the at least two monochromatic total reflection surfaces and the color combining total reflection surface, wherein the reflection surface and the display surface are arranged opposite to each other, and the incident surface and the exit surface are arranged opposite to each other, wherein the total reflection illumination light path first passes through the incident surface, and then is bent by total reflection at the at least two monochromatic total reflection surfaces, and the total reflection imaging light path first is bent by total reflection at the color combining total reflection surface, and then passes through the exit surface.

[0030] According to an embodiment of the present invention, the lighting assembly includes a lighting light source, wherein the lighting light source includes a first monochromatic light emitting unit for emitting a first path of monochromatic illumination light, a second monochromatic light emitting unit for emitting a second path of monochromatic illumination light, and a third monochromatic light emitting unit for emitting a third path of monochromatic illumination light.

[0031] According to an embodiment of the present invention, the lighting light source is an RGB triad light source, and the RGB triad light source is correspondingly arranged at the incident surface of the relay color combining device.

[0032] According to an embodiment of the present invention, the lighting light source includes an RB dyad light source and a G light source, wherein the RB dyad light source is correspondingly arranged at the incident surface of the relay color combining device, and the G light source is correspondingly arranged at the reflection surface of the relay color combining device.

[0033] According to an embodiment of the present invention, the lighting assembly further includes a condenser lens group, wherein the condenser lens group is correspondingly arranged between the lighting light source and the relay color combining device for collecting the at least two paths of monochromatic illumination light emitted by the lighting light source.

[0034] According to an embodiment of the present invention, the lighting assembly further includes a light homogenizing and shaping device, wherein the light homogenizing and shaping device is correspondingly arranged between the condenser lens group and the relay color combining device for shaping and homogenizing the at least two paths of monochromatic illumination light collimated by the condenser lens group.

[0035] According to an embodiment of the present invention, the imaging assembly is one of an imaging lens group, a catadioptric lens, a super lens, and a diffractive lens.

[0036] On the other hand of the present invention, the present invention further provides an electronic device, including:

[0037] a waveguide; and

[0038] a micro projection optical engine, wherein the micro projection optical engine is configured to project image light onto the waveguide to project the image light into a human eye for display through the waveguide; wherein the micro projection optical engine comprises:

[0039] an illumination component, wherein the illumination component is configured to provide at least two paths of monochromatic illumination light;

[0040] a digital micromirror device, wherein the digital micromirror device is configured to modulate the combined color illumination light into the image light;

[0041] an imaging component, wherein the imaging component is configured to project the image light onto the waveguide; and

[0042] a relay color combining device, wherein the relay color combining device is disposed between the illumination component, the digital micromirror device and the imaging component to form a total reflection illumination optical path between the illumination component and the digital micromirror device through the relay color combining device, and to form a total reflection imaging optical path between the digital micromirror device and the imaging component through the relay color combining device, wherein the relay color combining device is configured to combine the at least two paths of monochromatic illumination light from the illumination component into one path of combined color illumination light during the process of totally reflecting and transmitting the at least two paths of monochromatic illumination light to the digital micromirror device along the total reflection illumination optical path, and is configured to totally reflect and transmit the image light from the digital micromirror device to the imaging component along the total reflection imaging optical path.

[0043] According to another aspect of the present invention, the present invention further provides a color combining projection method for a micro projection optical engine, comprising the steps of:

[0044] providing at least two paths of monochromatic illumination light via an illumination component;

[0045] combining the at least two paths of monochromatic illumination light into one path of combined color illumination light during the process of totally reflecting and transmitting the at least two paths of monochromatic illumination light to a digital micromirror device along a total reflection illumination optical path of a relay color combining device;

[0046] modulating the combined color illumination light into corresponding image light via the digital micromirror device;

[0047] totally reflecting and transmitting the image light to an imaging component along a total reflection imaging optical path of the relay color combining device; and

[0048] projecting the image light via the imaging component for imaging.

[0049] Through the understanding of the subsequent description and the drawings, further objects and advantages of the present invention will be fully embodied.

[0050] These and other objects, features, and advantages of the present invention will be fully embodied in the following detailed description, the accompanying drawings, and the claims. Description of the Drawings

[0051] Figure 1 is a system schematic diagram of a micro-projection optical engine according to an embodiment of the present invention.

[0052] Figure 2 shows a structural schematic diagram of a relay color combining device of the micro-projection optical engine according to the above embodiment of the present invention.

[0053] Figure 3 shows an optical path schematic diagram of the micro-projection optical engine according to the above embodiment of the present invention.

[0054] Figure 4 shows a first variant embodiment of the micro-projection optical engine according to the above embodiment of the present invention.

[0055] Figure 5 shows a second variant embodiment of the micro-projection optical engine according to the above embodiment of the present invention.

[0056] Figure 6 shows a third variant embodiment of the micro-projection optical engine according to the above embodiment of the present invention.

[0057] Figure 7A is a schematic diagram of an electronic device according to the present invention.

[0058] Figure 7B is a schematic diagram of another electronic device according to the present invention.

[0059] Figure 8 shows a flowchart of a color combining projection method of a micro-projection optical engine according to an embodiment of the present invention. Detailed Embodiments

[0060] The following description is used to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments in the following description are only examples, and those skilled in the art can think of other obvious variants. The basic principles defined in the following description can be applied to other implementation schemes, variant schemes, improvement schemes, equivalent schemes, and other technical schemes that do not depart from the spirit and scope of the present invention.

[0061] Those skilled in the art should understand that in the disclosure of the present invention, the orientation or positional relationship indicated by terms such as "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the above terms should not be construed as limitations on the present invention.

[0062] In the present invention, the term "a" in the claims and the specification should be understood as "one or more". That is, in one embodiment, the number of an element can be one, while in other embodiments, the number of the element can be multiple. Unless it is clearly indicated in the disclosure of the present invention that the number of the element is only one, the term "a" should not be understood as being unique or single, and the term "a" should not be construed as a limitation on the number.

[0063] In the description of the present invention, it should be understood that terms such as "first", "second", etc. are only used for descriptive purposes and cannot be construed as indicating or implying relative importance. In the description of the present invention, it should be noted that unless otherwise clearly specified and limited, the terms "connected" and "coupled" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through a medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0064] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0065] Digital Light Procession (DLP) technology means that the image signal is first digitally processed and then the modulated light is projected to form the original image. The core of the DLP technology system is the optical engine, whose heart is the Digital Micromirror Device (DMD). That is to say, it uses the Digital Micromirror Device (referred to as the DMD chip) to achieve the final link of displaying digital image information. Currently, since the existing optical engines based on DLP technology use natural light illumination and do not require light of a specific polarization state, compared with the optical engines based on LCoS chips, the existing optical engines based on DLP technology have the advantages of high light energy utilization rate, high brightness, and high contrast of the presented images. However, the existing optical engines based on DLP technology have a large size and heavy weight due to the use of an independent color combining system, and cannot meet the application requirements of small size and light weight.

[0066] To solve the above problems, referring to the attached Figures 1 to 3 As shown, a micro-projection optical engine according to an embodiment of the present invention is illustrated, wherein the micro-projection optical engine 1 includes an illumination component 10, a digital micromirror device 20, an imaging component 30, and a relay color combining device 40. The illumination component 10 is used to provide at least two paths of monochromatic illumination light. The relay color combining device 40 is disposed between the illumination component 10, the digital micromirror device 20, and the imaging component 30 to form a total reflection illumination optical path 100 between the illumination component 10 and the digital micromirror device 20 through the relay color combining device 40, and form a total reflection imaging optical path 300 between the digital micromirror device 20 and the imaging component 30 through the relay color combining device 40. The relay color combining device 40 is used to synthesize the at least two paths of monochromatic illumination light from the illumination component 10 into a combined color illumination light during the total reflection transmission along the total reflection illumination optical path 100 to the digital micromirror device 20. The digital micromirror device 20 is used to modulate the combined color illumination light into image light, and the relay color combining device 30 is also used to transmit the image light modulated by the digital micromirror device 20 along the total reflection imaging optical path 300 to the imaging component 30 for projection and imaging by the imaging component 30.

[0067] It should be noted that when at least two paths of monochromatic illumination light from the illumination component 10 propagate along the total reflection illumination optical path 100, the at least two paths of monochromatic illumination light will respectively undergo total reflection within the relay color combining device 40 to change their propagation directions and be combined into one path of color combined illumination light. In other words, the micro-projection light engine 1 of the present invention does not require an additional independent color combining device. Only through the relay color combining device 40 can one path of color combined illumination light be synthesized during the process of transmitting the at least two paths of monochromatic illumination light from the illumination component 10 to the digital micromirror device 20, making the structure of the micro-projection light engine 1 more compact and helping to reduce the volume and size of the micro-projection light engine 1.

[0068] In addition, when the image light from the digital micromirror device 20 propagates along the total reflection imaging optical path 300, the image light will undergo total reflection within the relay color combining device 40 to change its propagation direction, which helps to extend the optical path of the image light. In this way, the micro-projection light engine 1 can provide a sufficiently long imaging optical path within a limited space, so as to further reduce the volume and weight of the micro-projection light engine 1.

[0069] In summary, the micro-projection light engine 1 of the present invention adopts an innovative optical path design, enabling total reflection to occur simultaneously in the total reflection illumination optical path 100 and the total reflection imaging optical path 300 within the relay color combining device 40, and integrating the color combining process into the total reflection illumination optical path 100 of the relay color combining device 40, which is beneficial to meeting the requirements of small volume, light weight, high brightness, high uniformity, and high resolution.

[0070] Specifically, as Figure 2 and Figure 3 shown, the relay color combining device 40 of the micro-projection light engine 1 has an incident surface 401 corresponding to the illumination component 10, at least two monochromatic total reflection surfaces 402, a reflection surface 403, a display surface 404 corresponding to the digital micromirror device 20, a color combining total reflection surface 405, and an exit surface 406 corresponding to the imaging component 30. Among them, the at least two monochromatic total reflection surfaces 402 and the color combining total reflection surface 405 are arranged at intervals in sequence to form at least two gaps 400 between the at least two monochromatic total reflection surfaces 402 and the color combining total reflection surface 405. The reflection surface 403 and the display surface 404 are arranged opposite to each other, and the incident surface 401 and the exit surface 406 are arranged opposite to each other. The total reflection illumination optical path 100 first passes through the incident surface 401 and then bends with total reflection at the at least two monochromatic total reflection surfaces 402, and the total reflection imaging optical path 300 first bends with total reflection at the color combining total reflection surface 405 and then passes through the exit surface 406.

[0071] In this way, as Figure 2 shown, the total reflection illumination optical path 100 of the micro projection optical engine 1 first extends from the illumination component 10, and after passing through the incident surface 401 of the relay color combining device 40, extends to at least two monochromatic total reflection surfaces 402 of the relay color combining device 40; then, after total reflection by the at least two monochromatic total reflection surfaces 402, the total reflection illumination optical path 100 extends from the at least two monochromatic total reflection surfaces 402 to the reflection surface 403; after that, after reflection by the reflection surface 403, the total reflection illumination optical path 100 starts to extend from the reflection surface 403, and after passing through the at least two monochromatic total reflection surfaces 402, the at least two gaps 400, the color combining total reflection surface 405, and the display surface 404, extends to the digital micromirror device 20. Correspondingly, the total reflection imaging optical path 300 of the micro projection optical engine 1 first extends from the digital micromirror device 20, and after passing through the display surface 404, extends to the color combining total reflection surface 405; finally, after total reflection by the color combining total reflection surface 405, the total reflection imaging optical path 300 starts to extend from the color combining total reflection surface 405, and after passing through the exit surface 406, extends to the imaging component 30.

[0072] In other words, as Figure 2 and Figure 3 shown, when the micro projection optical engine 1 works, at least two monochromatic illumination lights from the illumination component 10 first pass through the incident surface 401 of the relay color combining device 40, and then propagate to at least two monochromatic total reflection surfaces 402 of the relay color combining device 40 to respectively perform total reflection at the at least two monochromatic total reflection surfaces 402; then, the at least two monochromatic illumination lights totally reflected by the at least two monochromatic total reflection surfaces 402 will propagate to the reflection surface 403 to perform reflection at the reflection surface 403; after that, the combined color illumination light reflected from the reflection surface 403 will pass through the at least two total reflection surfaces 402, the at least two gaps 400, the color combining total reflection surface 405, and the display surface 404, and synthesize a combined color illumination light at the display surface 404, and then propagate to the digital micromirror device 20 to modulate the combined color illumination light into image light through the digital micromirror device; then, the image light modulated by the digital micromirror device 20 first passes through the display surface 404, and then propagates to the color combining total reflection surface 405 to perform total reflection at the color combining total reflection surface 405; finally, the image light totally reflected by the color combining total reflection surface 405 will first pass through the exit surface 406, and then propagate to the imaging component 30 to project the image light through the imaging component 30 for imaging.

[0073] More specifically, in the above embodiments of the present invention, as Figure 2 shown, the relay color combining device 40 includes a first prism 41, a second prism 42, and at least one optical element 43. The first prism 41 and the second prism 42 are arranged with their inclined surfaces facing each other, and the at least one optical element 43 is disposed between the first prism 41 and the second prism 42 at intervals. The first inclined surface 411 of the first prism 41 and the optical surface of the at least one optical element 43 respectively serve as the monochromatic total reflection surfaces 402, and the second inclined surface 421 of the second prism 42 serves as the color combining total reflection surface 405.

[0074] Preferably, as Figure 2 shown, the optical element 43 is implemented as a wedge prism 430, which helps to adjust and control the angle between the at least two monochromatic total reflection surfaces 402 and the color combining total reflection surface 405 or their respective inclination angles to meet the required total reflection conditions. Of course, in other examples of the present invention, the optical element 43 can also be implemented as a light-transmitting element that can provide the monochromatic total reflection surface 402, and the present invention will not elaborate on this.

[0075] Exemplarily, as Figure 2 shown, the at least one optical element 43 of the relay color combining device 40 may include a first wedge prism 430a and a second wedge prism 430b. The first wedge prism 430a and the second wedge prism 430b are sequentially stacked at intervals between the first inclined surface 411 of the first prism 41 and the second inclined surface 421 of the second prism 42 to form a first gap 400a among the at least two gaps 400 between the upper surface of the first wedge prism 430a and the first inclined surface 411 of the first prism 41, a second gap 400b among the at least two gaps 400 between the lower surface of the first wedge prism 430a and the upper surface of the second wedge prism 430b, and a third gap 400c among the at least two gaps 400 between the lower surface of the second wedge prism 430b and the second inclined surface 421 of the second prism 42. The first inclined surface 411 of the first prism 41, the lower surface of the first wedge prism 430a, and the lower surface of the second wedge prism 430b sequentially serve as a first monochromatic total reflection surface 402a, a second monochromatic total reflection surface 402b, and a third monochromatic total reflection surface 403c among the at least two monochromatic total reflection surfaces 402, and the second inclined surface 421 of the second prism 42 serves as the color combining total reflection surface 405.

[0076] It can be understood that the first prism 41, the first wedge prism 430a, the second wedge prism 430b, and the second prism 42 can be, but are not limited to, stacked at intervals by gluing to assemble the relay color combining device 40. In addition, in this embodiment of the present invention, the gap 400 in the relay color combining device 40 can be, but is not limited to, implemented as an air gap so that the light beam can undergo total internal reflection at the monochromatic total reflection surface 402 and the color combining total reflection surface 405. Of course, in other examples of the present invention, other transparent media with a lower refractive index, such as glue, etc., can also be provided between the first prism 41, the first wedge prism 430a, the second wedge prism 430b, and the second prism 42, so that the gap 400 in the relay color combining device 40 is implemented as a non-air gap, as long as it is ensured that the light beam can still undergo total internal reflection at the monochromatic total reflection surface 402 and the color combining total reflection surface 405 respectively, and the present invention will not elaborate on this anymore.

[0077] It is worth mentioning that, in this example of the present invention, as Figures 1 to 3As shown, the lighting assembly 10 may include a lighting light source 11, wherein the lighting light source 11 may include a first monochromatic light emitting unit 111 for emitting a first path of monochromatic lighting light 1101, a second monochromatic light emitting unit 112 for emitting a second path of monochromatic lighting light 1102, and a third monochromatic light emitting unit 113 for emitting a third path of monochromatic lighting light 1103. Moreover, the first monochromatic light emitting unit 111, the second monochromatic light emitting unit 112, and the third monochromatic light emitting unit 113 of the lighting light source 11 all correspond to the incident surface 401 of the relay color combining device 40, such that the first path of monochromatic lighting light 1101 from the first monochromatic light emitting unit 111 undergoes total internal reflection at the first monochromatic total reflection surface 402a after passing through the incident surface 401, the second path of monochromatic lighting light 1102 from the second monochromatic light emitting unit 112 undergoes total internal reflection at the second monochromatic total reflection surface 402b after passing through the incident surface 401 and the first monochromatic total reflection surface 402a, and the third path of monochromatic lighting light 1103 from the third monochromatic light emitting unit 113 undergoes total internal reflection at the third monochromatic total reflection surface 402c after passing through the incident surface 401, the first monochromatic total reflection surface 402a, and the second monochromatic total reflection surface 402b. Subsequently, the first path of monochromatic lighting light 1101 totally reflected from the first monochromatic total reflection surface 402a, the second path of monochromatic lighting light 1102 totally reflected from the second monochromatic total reflection surface 402b, and the third path of monochromatic lighting light 1103 totally reflected from the third monochromatic total reflection surface 402c will continue to propagate along the total internal reflection lighting optical path 100 to converge at the display surface 404 to form a combined color lighting light (i.e., the principal ray angles of the central field of view are the same when the first path of monochromatic lighting light 1101, the second path of monochromatic lighting light 1102, and the third path of monochromatic lighting light 1103 are emitted from the display surface 404 to achieve the color combining effect). Then, the combined color lighting light is propagated to the digital micromirror device 20 to be modulated into combined color image light, and further, the combined color image light is projected by the imaging assembly 30 to form a color image.

[0078] It should be noted that the first monochromatic light-emitting unit 111, the second monochromatic light-emitting unit 112, and the third monochromatic light-emitting unit 113 of the present invention are used to emit monochromatic illumination lights of different colors, so that the relay color-combining device 40 of the micro-projection light engine 1 of the present invention can achieve corresponding color-combining effects according to the different critical total reflection conditions corresponding to different angular distributions of monochromatic illumination lights of different colors. In other words, compared with the color-combining principle of a traditional dichroic mirror (i.e., a traditional dichroic mirror achieves the color-combining function through a color separation film), the relay color-combining device 40 of the present application achieves the color-combining function through the different critical total reflection conditions corresponding to different angular distributions of monochromatic illumination lights of different colors. That is to say, the relay color-combining device 40 of the present invention does not need to be additionally configured with a color separation film and can achieve corresponding color-combining effects only by using its own total reflection characteristics, which helps to simplify the complexity of the structure and reduce the volume and cost of the light engine.

[0079] For example, in an example of the present invention, the first monochromatic light-emitting unit 111, the second monochromatic light-emitting unit 112, and the third monochromatic light-emitting unit 113 of the illumination light source 11 may be successively implemented as a red light-emitting unit, a green light-emitting unit, and a blue light-emitting unit, and the first path of monochromatic illumination light 1101, the second path of monochromatic illumination light 1102, and the third path of monochromatic illumination light 1103 may be implemented as red light, green light, and blue light. Of course, in other examples of the present invention, the first path of monochromatic illumination light 1101, the second path of monochromatic illumination light 1102, and the third path of monochromatic illumination light 1103 may also be implemented as blue light, green light, or red light, or may also be implemented as monochromatic lights of other colors.

[0080] Preferably, the illumination light source 11 is implemented as an RGB tri-color light source, that is to say, the first monochromatic light-emitting unit 111, the second monochromatic light-emitting unit 112, and the third monochromatic light-emitting unit 113 are made by tri-color packaging, which helps to reduce the volume of the illumination light source 11 and further reduce the volume of the micro-projection light engine 1. It can be understood that in other examples of the present invention, the light-emitting module may also be implemented as other types of light sources such as an RGBW light source.

[0081] In addition, in the embodiment of the present invention, as Figure 1 and Figure 3As shown, the lighting assembly 10 of the micro projection optical engine 1 may further include a condenser lens group 12, where the condenser lens group 12 is correspondingly disposed between the lighting light source 11 and the relay color combining device 40 for collecting the at least two paths of monochromatic lighting light emitted by the lighting light source 11, so that the collimated at least two paths of monochromatic lighting light are incident on the relay color combining device 40. It can be understood that the condenser lens group 12 may include, but is not limited to, traditional spherical lenses, aspherical lenses, cylindrical lenses (with optical power in the Y-axis direction and no optical power in the X-axis direction), or Biconic lenses (with different optical powers in the X-axis and Y-axis directions), etc.

[0082] According to the above embodiments of the present invention, the reflecting surface 403 of the relay color combining device 40 is preferably implemented as a curved reflecting surface for shaping the at least two paths of monochromatic lighting light while reflecting it, so that the shaped lighting light meets the requirements of the digital micromirror device 20, which helps to improve the lighting beam quality of the micro projection optical engine 1.

[0083] Exemplarily, as Figure 2 and Figure 3 shown, the first prism 41 of the relay color combining device 40 is implemented as a curved prism 410, where the curved prism 410 has a flat side 412 and a curved side 413. The curved side 413 of the curved prism 410 serves as the reflecting surface 403 of the relay color combining device 40, and the flat side 412 of the curved prism 410 serves as the incident surface 401 of the relay color combining device 40. It can be understood that the curved prism 410 further has a flat inclined surface, where the flat inclined surface of the curved prism 410 corresponds to the first inclined surface 411 of the first prism 41 to serve as the first monochromatic total reflection surface 402a of the relay color combining device 40.

[0084] It should be noted that in the above example of the present invention, the curved side 413 of the curved prism 410 may be implemented as, but is not limited to, other types of curved surfaces such as spherical, aspherical, or cylindrical surfaces. Of course, in other examples of the present invention, the flat side 412 of the curved prism 410 (i.e., the incident surface 401 of the relay color combining device 40) is not limited to being implemented as a plane, and may also be implemented as, but is not limited to, curved surfaces such as spherical, aspherical, or cylindrical surfaces, which will not be elaborated herein.

[0085] Correspondingly, as Figure 2As shown, the second prism 42 of the relay color combining device 40 is implemented as a right-angle prism 420. The inclined surface of the right-angle prism 420 serves as the color combining total reflection surface 405 of the relay color combining device 40. One right-angle plane of the right-angle prism 420 serves as the display surface 404 of the relay color combining device 40, and the other right-angle plane of the right-angle prism 420 serves as the exit surface 406 of the relay color combining device 40. It can be understood that the first prism 41 of the present invention can also but is not limited to be implemented as other types of prisms with a curved side surface, as long as the relay color combining function of the relay color combining device 40 can be achieved. In addition, the right-angle prism 420 can but is not limited to be implemented as a total reflection prism, that is, the cross-section of the right-angle prism 420 can but is not limited to be an isosceles right triangle.

[0086] Preferably, the ineffective area of the curved surface prism 410 can be cut off. For example, the edge where the flat side surface 412 and the first inclined surface 411 of the curved surface prism 410 intersect is cut off, which helps to reduce the volume and weight of the curved surface prism 410, and further reduces the overall volume and weight of the micro-projection optical engine 1. Of course, in other examples of the present invention, as long as the total reflection illumination optical path 100 and the total reflection imaging optical path 300 are not affected, the edges of the first prism 41 of the relay color combining device 40 in the ineffective area can all be cut off to significantly reduce the overall volume and weight of the micro-projection optical engine 1, and the present invention will not elaborate here.

[0087] Furthermore, as Figure 2 and Figure 3 shown, the relay color combining device 40 of the present invention can also include a high-reflection film 44, where the high-reflection film 44 is disposed on the reflection surface 403 of the relay color combining device 40 for reflecting the at least two-way monochromatic illumination light at the reflection surface 403 of the relay color combining device 40, so as to enhance the reflection efficiency of the at least two-way monochromatic illumination light by the relay color combining device 40 at the reflection surface 403. It should be noted that the high-reflection film 44 of the relay color combining device 40 can but is not limited to be implemented as a silver film or a total reflection film to reduce the light energy loss of the illumination light at the reflection surface 403 of the relay color combining device 40, which helps to improve the light energy utilization rate of the micro-projection optical engine 1.

[0088] In addition, the relay color combining device 40 of the present invention can also include two anti-reflection films (not shown in the figure), where the anti-reflection films are respectively disposed on the total reflection surfaces 402 and 405 of the relay color combining device 40, which is beneficial to enhancing the transmission ability of the light beam at the total reflection surfaces 402 and 405 of the relay color combining device 40 to improve the light energy utilization rate of the entire system.

[0089] It is worth mentioning that, as Figure 3 shown, the imaging component 30 of the micro-projection optical engine 1 of the present invention can be, but is not limited to, implemented as an imaging lens group 31 for shaping the image light from the relay color combining device 40 to project an image with high imaging quality. It should be noted that since the illumination component 10 and the imaging component 30 are respectively located on opposite sides of the relay color combining device 40, that is, the propagation direction of the image light emitted from the relay color combining device 40 is the same as the propagation direction of the monochromatic illumination light incident on the relay color combining device 40, the micro-projection optical engine 1 has a linear structure, so as to reduce the volume or size of the micro-projection optical engine 1 and help meet the market demand for micro-projection optical engines with small volume.

[0090] Of course, in other examples of the present invention, the imaging component 30 of the micro-projection optical engine 1 can also be implemented as any other type of imaging system such as a catadioptric lens, a meta-lens, and a diffractive lens, as long as it can ensure that the imaging component 30 can project the image light from the relay color combining device 40, and the present invention does not further limit this.

[0091] It should be noted that since the refractive indices and surface inclination angles of the first prism 41 and the optical elements 43 (such as the first wedge prism 430a and the second wedge prism 430b) are different, it is necessary to reasonably select the refractive indices and surface inclination angles of the first prism 41 and the optical elements 43 to ensure that the first monochromatic illumination light 1101, the second monochromatic illumination light 1102, and the third monochromatic illumination light 1103 can propagate along the total reflection illumination optical path 100 to complete color combination.

[0092] Exemplarily, the refractive indices n 41 、n 430a 、n 430b of the first prism 41, the first wedge prism 430a, and the second wedge prism 430b need to simultaneously satisfy the following two conditions:

[0093] Condition 1:

[0094]

[0095]

[0096]

[0097] where: θ R1 、θ G1 and θ B1They are the incident angles of the first monochromatic illumination light 1101, the second monochromatic illumination light 1102, and the third monochromatic illumination light 1103 when they first enter the at least two monochromatic total reflection surfaces 402 respectively.

[0098] Condition 2:

[0099]

[0100]

[0101]

[0102] Where: θ R2 , θ G2 and θ B2 are the incident angles of the first monochromatic illumination light 1101, the second monochromatic illumination light 1102, and the third monochromatic illumination light 1103 when they secondarily enter the at least two monochromatic total reflection surfaces 402 respectively. It can be understood that (θ 41 ) max is the maximum value of the angles at which the first monochromatic illumination light 1101, the second monochromatic illumination light 1102, and the third monochromatic illumination light 1103 secondarily enter the first monochromatic total reflection surface 402a; (θ 430a ) max is the maximum value of the angles at which the first monochromatic illumination light 1101, the second monochromatic illumination light 1102, and the third monochromatic illumination light 1103 secondarily enter the second monochromatic total reflection surface 402b; (θ 430b ) max is the maximum value of the angles at which the first monochromatic illumination light 1101, the second monochromatic illumination light 1102, and the third monochromatic illumination light 1103 secondarily enter the third monochromatic total reflection surface 402c.

[0103] In summary, in the above embodiments of the present invention, the total reflection illumination optical path 100 of the micro projection optical engine 1 actually constitutes a Köhler illumination optical path. In other words, the micro projection optical engine 1 of the present invention mainly integrates the color mixing system and the Köhler illumination system to achieve the color mixing effect through the different critical total reflection conditions corresponding to the different angular distributions of different color lights, which helps to make the structure of the micro projection optical engine 1 more compact to meet the development trend of miniaturization and light weight.

[0104] Appendix Figure 4A first modified embodiment of the micro-projection optical engine 1 according to the above-described embodiment of the present invention is shown. Compared with the above-described embodiment of the present invention, the micro-projection optical engine 1 according to the first modified embodiment of the present invention is different in that: the first prism 41 of the relay color combining device 40 can be implemented as a triangular prism 410', where the triangular prism 410' has a first flat side 412' and a second flat side 413'; in addition, the relay color combining device 40 further includes a curved mirror 45, and the curved mirror 45 is correspondingly disposed on the second flat side 413' of the triangular prism 410' to provide the reflecting surface 403 of the relay color combining device 40 through the curved surface of the curved mirror 45. Accordingly, the first flat side 412' of the triangular prism 410' serves as the incident surface 401 of the relay color combining device 40, and the triangular prism 410' has a flat inclined surface corresponding to the first inclined surface 411 of the first prism 41 to serve as the first total reflection surface 402 of the relay color combining device 40. It can be understood that in this modified embodiment of the present invention, the first prism 41 of the relay color combining device 40 of the micro-projection optical engine 1 is easy to manufacture, which helps to reduce the manufacturing cost of the micro-projection optical engine 1.

[0105] It should be noted that in this modified embodiment of the present invention, the curved mirror 45 can be glued to the second flat side 413' of the triangular prism 410' to form a glued lens group for easy processing. Of course, in other examples of the present invention, a curved lens can also be glued to the first flat side 412' of the triangular prism 410' so that the incident surface 401 of the relay color combining device 40 can be implemented as a curved surface such as a spherical surface, an aspherical surface, and a cylindrical surface, etc., but not limited thereto.

[0106] Preferably, in this modified embodiment of the present invention, the relay color combining device 40 can further include the high-reflection film 44, where the high-reflection film 44 is disposed on the curved surface of the curved mirror 45 for reflecting the at least two-way monochromatic illumination light so as to enhance the reflection efficiency of the curved mirror 45 of the relay color combining device 40 for the at least two-way monochromatic illumination light.

[0107] Appendix Figure 5Shows a second variant embodiment of the micro projection optical engine 1 according to the above preferred embodiment of the present invention. Compared with the above first variant embodiment according to the present invention, the difference of the micro projection optical engine 1 according to the second variant embodiment of the present invention lies in that: the at least two monochromatic reflecting surfaces 402 of the relay color combining device 40 only include the first monochromatic total reflecting surface 402a and the second monochromatic total reflecting surface 402b. Correspondingly, the at least one optical element 43 of the relay color combining device 40 only includes one wedge prism 430, wherein the wedge prism 430 is disposed between the first prism 41 and the second prism 42 at intervals, and a first gap 400a is formed between the upper surface of the wedge prism 430 and the first inclined surface 411 of the first prism 41, and a second gap 400b is formed between the lower surface of the wedge prism 430 and the second inclined surface 421 of the second prism 42, so as to provide the first monochromatic total reflecting surface 402a and the second monochromatic total reflecting surface 402b through the first inclined surface 411 of the first prism 41 and the lower surface of the wedge prism 430 respectively.

[0108] It should be noted that in this variant embodiment of the present invention, as Figure 5As shown, the first monochromatic light-emitting unit 111 and the third monochromatic light-emitting unit 113 of the lighting light source 11 of the lighting assembly 10 are both arranged to correspond to the incident surface 401 of the relay color-combining device 40, and the second monochromatic light-emitting unit 112 of the lighting light source 11 is arranged to correspond to the reflection surface 403 of the relay color-combining device 40, such that the first monochromatic illumination light 1101 from the first monochromatic light-emitting unit 111 undergoes total internal reflection at the first monochromatic total reflection surface 402a after passing through the incident surface 401, and then is reflected at the reflection surface 403; the third monochromatic illumination light 1103 from the third monochromatic light-emitting unit 113 undergoes total internal reflection at the second monochromatic total reflection surface 402b after passing through the incident surface 401 and the first monochromatic total reflection surface 402a, and then is reflected at the reflection surface 403. And the second monochromatic illumination light 1102 from the second monochromatic light-emitting unit 112, after passing through the reflection surface 403, continues to propagate along the total internal reflection illumination optical path 100 together with the first monochromatic illumination light 1101 and the third monochromatic illumination light 1103 reflected from the reflection surface 403 to sequentially pass through the first monochromatic total reflection surface 402a, the second monochromatic total reflection surface 402b, and the display surface 404, and converge into a combined color illumination light at the display surface 404 (that is, the main ray angles of the first monochromatic illumination light 1101, the second monochromatic illumination light 1102, and the third monochromatic illumination light 1103 are the same when exiting from the display surface 404 to achieve a color-combining effect). After that, the combined color illumination light is propagated to the digital micromirror device 20 to be modulated into combined color image light, and then the combined color image light is projected into a color image through the imaging assembly 30.

[0109] Preferably, as Figure 5 shown, the relay color-combining device 40 further includes a selective reflection film 44', wherein the selective reflection film 44' is correspondingly arranged on the reflection surface 403 of the relay color-combining device 40 for selectively reflecting a part of the at least two monochromatic illumination lights and transmitting another part of the at least two monochromatic illumination lights. For example, the selective reflection film 44' can be used to reflect the first monochromatic illumination light 1101 and the third monochromatic illumination light 1103 and transmit the second monochromatic illumination light 1102.

[0110] It should be noted that the selective reflection film 44' can be, but is not limited to, implemented as a spectral splitting film that transmits and filters light and reflects red and blue light, for emitting red illumination light (R light) and blue illumination light (B light) and transmitting green illumination light (G light).

[0111] More preferably, the illumination light source 11 is implemented to include an RB two-in-one light source and a G light source. That is to say, the first single-color light-emitting unit 111 and the third single-color light-emitting unit 113 are made by two-in-one packaging, and the second single-color light-emitting unit 112 is separately packaged. In this way, since the critical total reflection condition of green illumination light (G light) is between the critical total reflection conditions of red illumination light (R light) and blue illumination light (B light), that is, the difference in the critical total reflection conditions between red illumination light (R light) and blue illumination light (B light) is relatively large. Therefore, in this variant embodiment of the present invention, the G light source and the RB two-in-one light source are arranged separately, so that when the relay color combining device 40 is designed, only the total reflection of R light and B light needs to be performed, and there is no need to perform total reflection on G light, which helps to reduce the design difficulty of the relay color combining device 40, and helps to reduce the packaging difficulty and manufacturing cost of the micro-projection light engine 1.

[0112] Exemplarily, in this variant embodiment of the present invention, the refractive indices n 41 , n 430 of the first prism 41 and the wedge prism 430 need to simultaneously satisfy the following two conditions:

[0113] Condition 1:

[0114]

[0115]

[0116] Where: θ R1 , θ G1 and θ B1 are the incident angles of the first path of single-color illumination light 1101, the second path of single-color illumination light 1102, and the third path of single-color illumination light 1103 when they first enter the at least two single-color total reflection surfaces 402, respectively.

[0117] Condition 2:

[0118]

[0119]

[0120] Where: θ R2 and θ B2 are the incident angles of the first path of single-color illumination light 1101 and the third path of single-color illumination light 1103 when they secondarily enter the at least two single-color total reflection surfaces 402, respectively; θ G1 is the incident angle of the second path of single-color illumination light 1102 when it first enters the at least two single-color total reflection surfaces 402.

[0121] Appendix Figure 6A third variant embodiment of the micro projection optical engine 1 according to the above-described embodiment of the present invention is shown. Compared with the above-described embodiment of the present invention, the micro projection optical engine 1 according to the third variant embodiment of the present invention is different in that: the illumination assembly 10 may further include a light homogenizing and shaping device 13, wherein the light homogenizing and shaping device 13 is disposed between the condenser lens group 12 and the incident surface 401 of the relay color combining device 40 for shaping and homogenizing the at least two monochromatic illumination lights collimated by the condenser lens group 12. It can be understood that the light homogenizing and shaping device 13 of the present invention may be implemented as, but not limited to, a compound eye or a micro-lens array group (Micro-lens array, abbreviated as MLA).

[0122] It should be noted that, since the total reflection illumination optical path 100 of the relay color combining device 40 in the above-described embodiment of the present invention is in the Köhler illumination form, the combined color illumination light synthesized along the total reflection illumination optical path 100 usually forms a circular spot or an elliptical spot on the digital micromirror device 20. However, the receiving surface of the digital micromirror device 20 is usually rectangular, which requires that the circular spot formed by the combined color illumination light cover the entire effective receiving surface of the digital micromirror device 20 to ensure the normal modulation operation of the digital micromirror device 20, thereby causing a certain sacrifice in the light energy utilization rate of the micro projection optical engine 1. In the third variant embodiment of the present invention, the light homogenizing and shaping device 13 breaks the original structure of the Köhler illumination. While homogenizing the at least two monochromatic illumination lights collimated by the condenser lens group 12, it can also shape the illumination combined spot to adjust the spot shape, so that the finally synthesized combined color illumination light can form a required rectangular spot on the digital micromirror device 20, thereby improving the light energy utilization rate of the micro projection optical engine 1.

[0123] According to another aspect of the present invention, the present invention further provides an electronic device configured with the micro projection optical engine 1. Specifically, as Figure 7A shown, the electronic device includes a waveguide 500 and any one of the above-described micro projection optical engines 1, wherein the micro projection optical engine 1 is used to project image light onto the waveguide 500 to project the image light into the human eye through the waveguide 500.

[0124] It should be noted that in the appendix Figure 7A the micro projection optical engine 1 and the human eye are located on the same side of the waveguide 500. Of course, as Figure 7BAs shown, in another example of the present invention, the micro-projection light engine 1 and the human eye may also be located on opposite sides (i.e., different sides) of the waveguide 500, and it is also possible to project the image light into the human eye. The present invention does not limit this, as long as it is ensured that the image light from the micro-projection light engine 1 is projected into the human eye through the waveguide 500. In addition, those skilled in the art can understand that the type of the electronic device is not limited. For example, the electronic device may be a near-eye display device such as an AR glasses or the like.

[0125] According to another aspect of the present invention, as Figure 8 shown, the present invention further provides a color-combining projection method for a micro-projection light engine, including the following steps:

[0126] S100: Provide at least two paths of monochromatic illumination light via an illumination component 10;

[0127] S200: Synthesize the at least two paths of monochromatic illumination light into a path of color-combined illumination light during the process of totally reflecting and transmitting the light along a total reflection illumination optical path 100 of a relay color combiner 40 to a digital micromirror device 20;

[0128] S300: Modulate the color-combined illumination light into corresponding image light via the digital micromirror device 20;

[0129] S400: Totally reflect and transmit the image light along a total reflection imaging optical path 300 of the relay color combining device 40 to an imaging component 30; and

[0130] S500: Project the image light via the imaging component 30 for imaging.

[0131] Those skilled in the art should understand that the embodiments of the present invention described above and shown in the drawings are only examples and do not limit the present invention. The object of the present invention has been completely and effectively achieved. The function and structural principle of the present invention have been shown and described in the embodiments. Without departing from the principle, the embodiments of the present invention may have any deformation or modification.

Claims

1. A relay color combining device, for assembling with an illumination component, a digital micromirror device, and an imaging component to form a micro-projection optical engine, characterized in that The relay color combining device has: A total reflection illumination optical path, which is adapted to be formed between the illumination component and the digital micromirror device, for combining at least two monochromatic illumination lights from the illumination component into a combined color illumination light during the process of totally reflecting and transmitting the lights along the total reflection illumination optical path to the digital micromirror device, so as to be modulated by the digital micromirror device into corresponding image light; And A total reflection imaging optical path, which is adapted to be formed between the digital micromirror device and the imaging component, for totally reflecting and transmitting the image light from the digital micromirror device along the total reflection imaging optical path to the imaging component, so as to be projected and imaged by the imaging component.

2. The relay color combining device according to claim 1, wherein, The relay color combining device further has an incident surface corresponding to the illumination component, at least two monochromatic total reflection surfaces, a reflection surface, a display surface corresponding to the digital micromirror device, a combined color total reflection surface, and an exit surface corresponding to the imaging component. The at least two monochromatic total reflection surfaces and the combined color total reflection surface are arranged at intervals in sequence, so as to respectively form at least two gaps between the at least two monochromatic total reflection surfaces and the combined color total reflection surface. The reflection surface and the display surface are arranged opposite to each other, and the incident surface and the exit surface are arranged opposite to each other. The total reflection illumination optical path first passes through the incident surface, and then is totally reflected and bent at the at least two monochromatic total reflection surfaces, and the total reflection imaging optical path is first totally reflected and bent at the combined color total reflection surface, and then passes through the exit surface.

3. The relay color combining device according to claim 2, wherein The relay color combining device includes a first prism, a second prism, and at least one optical element. The first prism and the second prism are arranged with their inclined surfaces facing each other, and the at least one optical element is disposed at intervals between the first prism and the second prism. The first inclined surface of the first prism and the optical surface of the at least one optical element respectively serve as the monochromatic total reflection surfaces, and the second inclined surface of the second prism serves as the combined color total reflection surface.

4. The relay color combination device according to claim 3, wherein, The at least one optical element includes a first wedge prism and a second wedge prism. The first wedge prism and the second wedge prism are stacked at intervals in sequence between the first inclined surface of the first prism and the second inclined surface of the second prism, so as to form a first gap between the upper surface of the first wedge prism and the first inclined surface of the first prism, a second gap between the lower surface of the first wedge prism and the upper surface of the second wedge prism, and a third gap between the lower surface of the second wedge prism and the second inclined surface of the second prism. The first inclined surface of the first prism, the lower surface of the first wedge prism, and the lower surface of the second wedge prism respectively serve as a first monochromatic total reflection surface, a second monochromatic total reflection surface, and a third monochromatic total reflection surface among the at least two monochromatic total reflection surfaces.

5. The relay color combining device according to claim 4, wherein, The relay color combining device further includes a high reflection film, wherein the high reflection film is correspondingly disposed on the reflection surface of the relay color combining device for reflecting the at least two monochromatic illumination lights at the reflection surface.

6. The relay color combining device according to claim 3, wherein, The at least one optical element includes a wedge prism, wherein the wedge prism is disposed at intervals between the first inclined surface of the first prism and the second inclined surface of the second prism to form a first gap between the upper surface of the wedge prism and the first inclined surface of the first prism, and a second gap between the lower surface of the wedge prism and the second inclined surface of the second prism, wherein the first inclined surface of the first prism and the lower surface of the wedge prism respectively serve as a first monochromatic total reflection surface and a second monochromatic total reflection surface among the at least two monochromatic total reflection surfaces.

7. The relay color combination device according to claim 6, wherein, The relay color combining device further includes a selective reflection film, wherein the selective reflection film is correspondingly disposed on the reflection surface of the relay color combining device for selectively reflecting a part of the at least two monochromatic illumination lights and transmitting another part of the at least two monochromatic illumination lights.

8. The relay color combining device according to any one of claims 3 to 7, wherein, The second prism is a right-angle prism, and the first prism is a curved surface prism, wherein a curved surface side of the curved surface prism serves as the reflection surface of the relay color combining device.

9. The relay color combining device according to any one of claims 3 to 7, wherein, The second prism is a right-angle prism, and the first prism is a triangular prism. The relay color combining device further includes a curved surface mirror, and the curved surface mirror is correspondingly disposed on a flat side of the triangular prism to provide the reflection surface of the relay color combining device through the curved surface of the curved surface mirror.

10. Miniature projection optical engine, characterized in that, Comprising: An illumination assembly, wherein the illumination assembly is used for providing at least two monochromatic illumination lights; A digital micromirror device, wherein the digital micromirror device is used for modulating the combined color illumination light into corresponding image light; An imaging assembly, wherein the imaging assembly is used for projecting the image light to form an image; and A relay color combining device, wherein the relay color combining device is disposed between the illumination assembly, the digital micromirror device and the imaging assembly to form a total reflection illumination optical path between the illumination assembly and the digital micromirror device through the relay color combining device, and form a total reflection imaging optical path between the digital micromirror device and the imaging assembly through the relay color combining device, wherein the relay color combining device is used for combining the at least two monochromatic illumination lights from the illumination assembly into one combined color illumination light during the process of totally reflecting and transmitting the lights to the digital micromirror device along the total reflection illumination optical path, and for totally reflecting and transmitting the image light from the digital micromirror device to the imaging assembly along the total reflection imaging optical path.

11. The micro-projection optical engine according to claim 10, wherein, The relay color combining device has an incident surface corresponding to the lighting component, at least two monochromatic total reflection surfaces, a reflection surface, a display surface corresponding to the digital micromirror device, a color combining total reflection surface, and an exit surface corresponding to the imaging component. The at least two monochromatic total reflection surfaces and the color combining total reflection surface are arranged at intervals in sequence to respectively form at least two gaps between the at least two monochromatic total reflection surfaces and the color combining total reflection surface. The reflection surface and the display surface are arranged opposite to each other, and the incident surface and the exit surface are arranged opposite to each other. The total reflection illumination optical path first passes through the incident surface, and then is bent by total reflection at the at least two monochromatic total reflection surfaces. The total reflection imaging optical path first is bent by total reflection at the color combining total reflection surface, and then passes through the exit surface.

12. The micro-projection optical engine according to claim 11, wherein, The lighting component includes a lighting light source, and the lighting light source includes a first monochromatic light emitting unit for emitting a first path of monochromatic illumination light, a second monochromatic light emitting unit for emitting a second path of monochromatic illumination light, and a third monochromatic light emitting unit for emitting a third path of monochromatic illumination light.

13. The micro-projection optical engine according to claim 12, wherein, The lighting light source is an RGB three-in-one light source, and the RGB three-in-one light source is correspondingly arranged on the incident surface of the relay color combining device.

14. The micro projection optical engine according to claim 12, wherein, The lighting light source includes an RB two-in-one light source and a G light source. The RB two-in-one light source is correspondingly arranged on the incident surface of the relay color combining device, and the G light source is correspondingly arranged on the reflection surface of the relay color combining device.

15. The micro-projection optical engine according to any one of claims 12 to 14, wherein, The lighting component further includes a condenser lens group, and the condenser lens group is correspondingly arranged between the lighting light source and the relay color combining device for collecting the at least two paths of monochromatic illumination light emitted by the lighting light source.

16. The micro projection optical engine according to claim 15, wherein The lighting component further includes a light homogenizing and shaping device, and the light homogenizing and shaping device is correspondingly arranged between the condenser lens group and the relay color combining device for shaping and homogenizing the at least two paths of monochromatic illumination light collimated by the condenser lens group.

17. The micro-projection optical engine according to any one of claims 10 to 14, wherein The imaging component is one of an imaging lens group, a catadioptric lens, a meta-lens, and a diffractive lens.

18. An electronic device, characterized in that, Including: A waveguide; And A micro-projection optical engine, where the micro-projection optical engine is used to project image light onto the waveguide to project the image light onto the human eye for display through the waveguide. The micro-projection optical engine includes: A lighting component, where the lighting component is used to provide at least two paths of monochromatic illumination light; A digital micromirror device, where the digital micromirror device is used to modulate the combined color illumination light into the image light; An imaging component, where the imaging component is used to project the image light onto the waveguide; and A relay color combining device, wherein the relay color combining device is disposed between the lighting component, the digital micromirror device, and the imaging component, so as to form a total reflection illumination optical path between the lighting component and the digital micromirror device through the relay color combining device, and form a total reflection imaging optical path between the digital micromirror device and the imaging component through the relay color combining device, wherein the relay color combining device is configured to combine at least two monochromatic illumination lights from the lighting component into a combined color illumination light during the process of totally reflecting and transmitting the at least two monochromatic illumination lights along the total reflection illumination optical path to the digital micromirror device, and is configured to totally reflect and transmit the image light from the digital micromirror device along the total reflection imaging optical path to the imaging component.

19. Color-combined projection method of a micro-projection optical engine, characterized in that, Including the steps of: Providing at least two monochromatic illumination lights via a lighting component; Combining the at least two monochromatic illumination lights into a combined color illumination light during the process of totally reflecting and transmitting the at least two monochromatic illumination lights along a total reflection illumination optical path of a relay color combining device to a digital micromirror device; Modulating the combined color illumination light into a corresponding image light via the digital micromirror device; Totally reflecting and transmitting the image light along a total reflection imaging optical path of the relay color combining device to an imaging component; and Projecting the image light via the imaging component for imaging.

Images