Color mixing device, its method and lighting system

Abstract

A color combining device, method, and lighting system. The color combining device includes: a second prism for totally reflecting a second path of monochromatic light; a third prism for totally reflecting a third path of monochromatic light; a first film system for reflecting the second path of monochromatic light and transmitting the first path of monochromatic light and the third path of monochromatic light; and a second film system for reflecting the third path of monochromatic light and transmitting the first path of monochromatic light. The first film system is located between the second prism and the third prism, and is used to reflect the second path of monochromatic light that has been totally reflected by the second prism back to the second prism for propagation along a combined color light path. The third prism is located between the second film system and the first film system, wherein the second film system is used to reflect the third path of monochromatic light that has been totally reflected by the third prism back to the third prism for propagation along the combined color light path, and the second film system is also used to transmit the first path of monochromatic light for propagation along the combined color light path.

Description

Technical Field

[0001] The present invention relates to the field of projection technology, and in particular to a color combining device and method thereof, and an illumination system. Background Art

[0002] In recent years, the emergence of microdisplay chip technology has made miniaturized and high-resolution projection displays possible. With the continuous development of projection display technology and market demand, microprojection light engines with large fields of view, high image quality, compact size, and wearable features are gaining increasing attention, especially in the hotly developing fields of augmented reality (AR), near-eye display (NED), and wearables.

[0003] However, in order to achieve color display, the existing micro-projection light engine usually uses a color combining device such as an X-Cube to combine the three primary color polarized lights from three light paths into the same light path. Figure 1 As shown, the X color-combining prism is usually composed of four right-angle prisms 11P glued together along the right-angle surfaces, and the right-angle surfaces of the right-angle prisms 11P are coated with corresponding first and second film systems 12P and 13P; the oblique surfaces of the four right-angle prisms 11P serve as the input surface and output surface of light respectively, and the red, green and blue primary color polarized light sources 21P, 22P and 23P correspond to the oblique surfaces of three right-angle prisms 11P respectively, and the oblique surface of the remaining right-angle prism 11P serves as the output surface after the three primary colors of light are combined into white light.

[0004] However, although the X-color combining prism can combine three primary color polarized lights into one white light, it is limited by the structure of the X-color combining prism itself. Its structure is relatively loose and bulky, resulting in a lighting system equipped with the X-color combining prism being relatively large in size and weight, which cannot meet the market demand for small size and light weight.

[0005] In addition, if Figure 1 As shown, the first film system 12P of the X-color combining prism is a short-wavelength pass dichroic filter that reflects red light and transmits blue and green light. The second film system 13P is a long-wavelength pass dichroic filter that reflects blue light and transmits red and green light. This places high demands on the film system design. Furthermore, the manufacturing of the X-color combining prism is relatively complex. This is due to the high degree of consistency required for the first and second film systems 12P and 13P coated on the right-angled surfaces of the right-angle prism 11P. Furthermore, the X-shaped intersection lines between the four right-angle prisms 11P are prone to misalignment when the right-angled surfaces of the right-angle prisms 11P are glued together. Summary of the Invention

[0006] An advantage of the present invention is that it provides a color combining device, a method thereof, and a lighting system, which can replace three paths of monochromatic light into one path of light to achieve a corresponding color combining effect.

[0007] Another advantage of the present invention is to provide a color combining device, a method thereof, and a lighting system. In one embodiment of the present invention, the color combining device has a compact structure, which helps to reduce the size and volume of the lighting system.

[0008] Another advantage of the present invention is to provide a color combining device, method thereof, and lighting system. In one embodiment of the present invention, the color combining device can adopt common coating and gluing processes, and there is no problem of difficult alignment, which is conducive to reducing costs.

[0009] Another advantage of the present invention is to provide a color combining device, method thereof, and lighting system. In one embodiment of the present invention, the color combining device has high color combining efficiency and is applicable to various types of projection display systems.

[0010] Another advantage of the present invention is to provide a color combining device, method, and lighting system. In one embodiment of the present invention, the color combining device can ensure that the optical paths of the three image lights in the color combining device are equal during the process of combining the three image lights, which helps to reduce aberrations and improve image quality.

[0011] Another advantage of the present invention is to provide a color combining device, method thereof, and lighting system. In one embodiment of the present invention, the color combining device can reduce the size or volume of the color combining device by folding back while ensuring that a sufficient optical path is provided for image light.

[0012] Another advantage of the present invention is providing a color combining device, method, and lighting system that achieve the aforementioned objectives without requiring expensive materials or complex structures. Thus, the present invention successfully and effectively provides a solution that not only provides a simple color combining device, method, and lighting system, but also increases the practicality and reliability of the color combining device, method, and lighting system.

[0013] To achieve at least one of the above advantages or other advantages and purposes, the present invention provides a color combining device for combining a first path of monochromatic light, a second path of monochromatic light, and a third path of monochromatic light into one path of light, wherein the color combining device has a combined light path and includes:

[0014] a second prism, configured to totally reflect the second monochromatic light incident on the second prism;

[0015] a third prism, configured to totally reflect the third path of monochromatic light incident upon the third prism;

[0016] a first film system, wherein the first film system is configured to reflect the second monochromatic light and transmit the first monochromatic light and the third monochromatic light, wherein the first film system is located between the second prism and the third prism, and the first film system is configured to reflect the second monochromatic light totally reflected by the second prism back to the second prism, so that the second monochromatic light propagates along the combined color light path after passing through the second prism; and

[0017] A second film system, wherein the second film system is used to reflect the third monochromatic light and transmit the first monochromatic light, wherein the third prism is located between the second film system and the first film system, wherein the second film system is used to reflect the third monochromatic light that is totally reflected by the third prism back to the third prism, so that the third monochromatic light propagates along the combined light path after passing through the third prism, the first film system and the second prism in sequence, and the second film system is also used to transmit the first monochromatic light to the third prism, so that the first monochromatic light propagates along the combined light path after passing through the second film system, the third prism, the first film system and the second prism in sequence.

[0018] In one embodiment of the present invention, the color combining device further includes a first prism, wherein the second film system is located between the first prism and the third prism, and is used to allow the first path of monochromatic light to propagate along the color combining light path after passing through the first prism, the second film system, the third prism, the first film system and the second prism in sequence.

[0019] In one embodiment of the present invention, the first prism has a first incident surface and a first exit surface, and the first exit surface of the first prism faces the second film system, so that the first path of monochromatic light incident from the first incident surface is emitted from the first exit surface after passing through the first prism to be emitted toward the second film system.

[0020] In one embodiment of the present invention, the first prism further has a first functional surface, wherein the first functional surface of the first prism serves as a total reflection surface for totally reflecting the first path of monochromatic light incident from the first incident surface, so that the first path of monochromatic light after total reflection is emitted from the first exit surface.

[0021] In one embodiment of the present invention, the color combining device further includes a third film system, wherein the third film system is used to reflect the first monochromatic light, and the third film system is correspondingly arranged on the first prism to reflect the first monochromatic light incident from the first incident surface, so that the reflected first monochromatic light is emitted from the first exit surface.

[0022] In one embodiment of the present invention, the second prism has a second incident surface and a second exit surface, wherein the second exit surface of the second prism serves as a total reflection surface for totally reflecting the second monochromatic light incident from the second incident surface, so that the second monochromatic light after total reflection is emitted toward the first film system.

[0023] In one embodiment of the present invention, the second prism further has a second functional surface, wherein the second functional surface of the second prism faces the third prism, and the first film is coated on the second functional surface of the second prism.

[0024] In one embodiment of the present invention, the third prism has a third incident surface and a third exit surface, wherein the third exit surface of the third prism serves as a total reflection surface, and the third exit surface of the third prism corresponds to the second functional surface of the second prism, and is used to totally reflect the third monochromatic light incident from the third incident surface, so that the third monochromatic light after total reflection is emitted toward the second film system.

[0025] In one embodiment of the present invention, the third prism further has a third functional surface, wherein the third functional surface of the third prism corresponds to the first exit surface of the first prism, and the second film is coated on the third functional surface of the third prism.

[0026] In one embodiment of the present invention, the color combining device further comprises an air gap, wherein the air gap is located between the third exit surface of the third prism and the first film system.

[0027] In one embodiment of the present invention, the color combining device further includes an anti-reflection film, wherein the anti-reflection film is respectively arranged on the first incident surface and the first exit surface of the first prism, the second incident surface of the second prism, and the third incident surface of the third prism.

[0028] In one embodiment of the present invention, the first film is a red light reflecting film or a blue light reflecting film, and the second film is correspondingly the blue light reflecting film or the red light reflecting film.

[0029] According to another aspect of the present invention, the present invention further provides a lighting system, comprising:

[0030] A light source unit, wherein the light source unit comprises:

[0031] a first light-emitting element, configured to emit a first path of monochromatic light;

[0032] a second light-emitting element, configured to emit a second path of monochromatic light; and

[0033] a third light-emitting element, configured to emit a third path of monochromatic light; and

[0034] A color combining device, wherein the color combining device has a color combining light path and comprises:

[0035] a second prism, wherein the second prism corresponds to the second light-emitting element, and the second prism has a total reflection structure for totally reflecting the second path of monochromatic light from the second light-emitting element;

[0036] a third prism, wherein the third prism corresponds to the third light-emitting element and has a total reflection structure for totally reflecting the third path of monochromatic light from the third light-emitting element;

[0037] a first film system, wherein the first film system is configured to reflect the second monochromatic light and transmit the first monochromatic light and the third monochromatic light, wherein the first film system is located between the second prism and the third prism, and the first film system is configured to reflect the second monochromatic light totally reflected by the second prism back to the second prism, so that the second monochromatic light propagates along the combined color light path after passing through the second prism; and

[0038] A second film system, wherein the second film system is used to reflect the third monochromatic light and transmit the first monochromatic light, wherein the third prism is located between the second film system and the first film system, wherein the second film system is used to reflect the third monochromatic light that is totally reflected by the third prism back to the third prism, so that the third monochromatic light propagates along the combined light path after passing through the third prism, the first film system and the second prism in sequence, and the second film system is also used to transmit the first monochromatic light from the first light-emitting element to the third prism, so that the first monochromatic light propagates along the combined light path after passing through the second film system, the third prism, the first film system and the second prism in sequence.

[0039] In one embodiment of the present invention, the color combining device further includes a first prism, wherein the second film system is located between the first prism and the third prism, and the first prism corresponds to the first light-emitting element, and is used to allow the first path of monochromatic light from the first light-emitting element to propagate along the color combining light path after passing through the first prism, the second film system, the third prism, the first film system and the second prism in sequence.

[0040] In one embodiment of the present invention, the sizes of the first prism, the second prism and the third prism of the color combining device match each other, so as to make the optical paths of the first monochromatic light, the second monochromatic light and the third monochromatic light in the color combining device the same.

[0041] In one embodiment of the present invention, the first light-emitting element, the second light-emitting element, and the third light-emitting element are monochromatic MicroLEDs of different colors.

[0042] According to another aspect of the present invention, the present invention further provides a color combination method, comprising the steps of:

[0043] Totally reflecting the second monochromatic light and the third monochromatic light respectively to change the propagation directions of the second monochromatic light and the third monochromatic light; and

[0044] The second monochromatic light and the third monochromatic light that have been totally reflected are respectively reflected to change the propagation directions of the second monochromatic light and the third monochromatic light again, so that the second monochromatic light and the third monochromatic light propagate along the same optical path as the first monochromatic light at the same time after being turned twice.

[0045] In one embodiment of the present invention, the color combining method further comprises the steps of:

[0046] The first monochromatic light is reflected to change the propagation direction of the first monochromatic light, so that the second monochromatic light and the third monochromatic light propagate along the same optical path as the reflected first monochromatic light after being turned twice.

[0047] Further objects and advantages of the present invention will be fully apparent from an understanding of the following description and accompanying drawings.

[0048] These and other objects, features and advantages of the present invention will be more fully understood from the following detailed description, accompanying drawings and claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 A schematic diagram of the color combining principle of an illumination system equipped with an X color combining prism in the prior art is shown.

[0050] Figure 2 FIG. 1 is a schematic structural diagram of a lighting system according to an embodiment of the present invention.

[0051] Figure 3 A schematic diagram of the color combination principle of the lighting system according to the above embodiment of the present invention is shown.

[0052] Figure 4A and Figure 4B A first modified implementation of the lighting system according to the above embodiment of the present invention is shown.

[0053] Figure 5 A second variant implementation of the lighting system according to the above embodiment of the present invention is shown.

[0054] Figure 6A third modified implementation of the lighting system according to the above embodiment of the present invention is shown.

[0055] Figure 7 2 is a flow chart of a color combining method according to an embodiment of the present invention. DETAILED DESCRIPTION

[0056] The following description is intended to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments described below are for illustrative purposes only, and those skilled in the art will readily appreciate other obvious variations. The basic principles of the present invention defined in the following description may be applied to other embodiments, variations, improvements, equivalents, and other technical solutions that do not depart from the spirit and scope of the present invention.

[0057] Those skilled in the art should understand that, in the disclosure of the present invention, the terms "longitudinal", "transverse", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like to indicate orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply 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 understood as limiting the present invention.

[0058] In the present invention, the term "a" or "an" in the claims and the specification should be understood as "one or more." That is, in one embodiment, the number of an element may be one, while in another embodiment, the number of the element may be multiple. Unless the disclosure of the present invention clearly indicates that the number of the element is only one, the term "a" or "an" should not be understood as a unique or singular element, and the term "a" or "an" should not be understood as a limitation on the quantity.

[0059] In the description of the present invention, it should be understood that the terms "first", "second", etc. are used for descriptive purposes only and should not be understood 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 "connected" 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.

[0060] In the description of this specification, the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction 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 any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0061] Refer to the attached figure Figure 2 and Figure 3 FIG. 1 illustrates an illumination system according to an embodiment of the present invention. Specifically, the illumination system 1 includes a light source unit 10 and a color combining device 20, wherein the light source unit 10 is correspondingly disposed on the light incident side of the color combining device 20, and the light source unit 10 is configured to provide three paths of monochromatic light to the color combining device 20. The color combining device 20 has a combined light path (not shown) for combining the three paths of monochromatic light provided by the light source unit 10 into one path of light propagating along the combined light path.

[0062] More specifically, if Figure 2 and Figure 3 As shown, the light source unit 10 may include a first light-emitting element 11, a second light-emitting element 12, and a third light-emitting element 13, wherein the first light-emitting element 11 is configured to emit a first monochromatic light 101; the second light-emitting element 12 is configured to emit a second monochromatic light 102; and the third light-emitting element 13 is configured to emit a third monochromatic light 103. It is worth noting that the first light-emitting element 11, the second light-emitting element 12, and the third light-emitting element 13 are preferably implemented as a green light-emitting element, a red light-emitting element, and a blue light-emitting element, respectively, so that the first monochromatic light 101, the second monochromatic light 102, and the third monochromatic light 103 are implemented as three primary colors of green, red, and blue (i.e., RGB) light, respectively. It is understood that in other examples of the present invention, the first light-emitting element 11, the second light-emitting element 12, and the third light-emitting element 13 may also be implemented as light-emitting elements of other colors to emit corresponding monochromatic lights.

[0063] In the above embodiment of the present invention, the color combining device 20 is used to combine the first monochromatic light 101 from the first light-emitting element 11, the second monochromatic light 102 from the second light-emitting element 12, and the third monochromatic light 103 from the third light-emitting element 13 into a combined light that propagates along the combined light path. It is understood that in order to ensure that the drawings can clearly illustrate the color combining process and principle of the color combining device 20, for example, Figure 3 In the accompanying drawings, the three monochromatic lights propagating along the combined light path after color combination are drawn separately.

[0064] In particular, Figure 2 and Figure 3 As shown, the color combining device 20 of the present invention may include a first prism 21, a second prism 22, a third prism 23, a first film system 24, and a second film system 25, wherein the third prism 23 is disposed between the first prism 21 and the second prism 22, the first film system 24 is disposed between the second prism 22 and the third prism 23, and the second film system 25 is disposed between the first prism 21 and the third prism 23. The first light-emitting element 11, the second light-emitting element 12, and the third light-emitting element 13 in the light source unit 10 are disposed to correspond to the first prism 21, the second prism 22, and the third prism 23 in the color combining device 20, respectively, so that the first monochromatic light 101, the second monochromatic light 102, and the third monochromatic light 103 emitted by the first light-emitting element 11, the second light-emitting element 12, and the third light-emitting element 13 are incident on the first prism 21, the second prism 22, and the third prism 23, respectively.

[0065] It is worth noting that in the above embodiments of the present invention, Figure 3 As shown, the structures of the second prism 22 and the third prism 23 can ensure that the light angles of the second monochromatic light 102 and the third monochromatic light 103 after respectively entering the second prism 22 and the third prism 23 meet the total reflection condition, so as to cause the second monochromatic light 102 and the third monochromatic light 103 to be totally reflected in the second prism 22 and the third prism 23 respectively, so as to change the propagation direction of the second monochromatic light 102 and the third monochromatic light 103, so that the second monochromatic light 102 and the third monochromatic light 103 propagate toward the first film system 24 and the second film system 25 respectively.

[0066] like Figure 3As shown, the first film system 24 is preferably used to reflect the second monochromatic light 102 and transmit the first monochromatic light 101 and the third monochromatic light 103; the second film system 25 is preferably used to reflect the third monochromatic light 103 and transmit the first monochromatic light 101. More preferably, the second film system 25 is used to reflect the third monochromatic light 103 and transmit the first monochromatic light 101 and the second monochromatic light.

[0067] In this way, Figure 3 As shown, the first monochromatic light 101 from the first light-emitting element 11 can sequentially pass through the first prism 21, the second film system 25, the third prism 23, the first film system 24, and the second prism 24 and then propagate along the combined color light path of the color combining device 20; the second monochromatic light 102 from the second light-emitting element 12 first undergoes total reflection in the second prism 22 to propagate to the first film system 24, and after being reflected back to the second prism 22 by the first film system 24, it then passes through the second prism 22 and then propagates along the combined color light path of the color combining device 20; the third monochromatic light 103 from the third light-emitting element 13 first undergoes total reflection in the third prism 23 to propagate to the second film system 25, and after being reflected back to the third prism 23 by the second film system 24, it then sequentially passes through the third prism 23, the first film system 24, and the second prism 24 and then propagates along the combined color light path of the color combining device 20. In this way, the first monochromatic light 101, the second monochromatic light 102 and the third monochromatic light 103 emitted from the color combining device 20 are all propagated along the combined light path of the color combining device 20, so that the first monochromatic light 101 from the first light-emitting element 11, the second monochromatic light 102 from the second light-emitting element 12 and the third monochromatic light 103 from the third light-emitting element 13 are combined into a combined color light (such as colored light) in the color combining device 20.

[0068] For example, in the above embodiments of the present invention, Figure 3 As shown, the first prism 21 has a first incident surface 211 and a first exit surface 212, wherein the first incident surface 211 of the first prism 21 faces the first light-emitting element 11, and the first exit surface 212 of the first prism 21 faces the second film system 25, so that the first path of monochromatic light 101 from the first light-emitting element 11 can be incident from the first incident surface 211 of the first prism 21, and after being emitted from the first exit surface 212 of the first prism 21, it is emitted toward the second film system 25.

[0069] like Figure 3As shown, the second prism 22 has a second incident surface 221 and a second exit surface 222, wherein the second exit surface 222 of the second prism 22 is a total reflection surface, and the second incident surface 221 of the second prism 22 faces the second light-emitting element 12, so that the second path of monochromatic light 102 from the second light-emitting element 12 can be incident from the second incident surface 221 of the second prism 22, and after being totally reflected at the second exit surface 222 of the second prism 22, it is emitted toward the first film system 24.

[0070] like Figure 3 As shown, the third prism 23 has a third incident surface 231 and a third exit surface 232, and the third exit surface 232 is a total reflection surface, wherein the third light-emitting element 13 corresponds to the third incident surface 231 of the third prism 23, so that the third monochromatic light 103 from the third light-emitting element 13 can be incident from the third incident surface 231 of the third prism 23, and after total reflection at the third exit surface 232 of the third prism 23, it is emitted toward the second film system 25. The third prism 23 is arranged between the first prism 21 and the second prism 22, wherein the third exit surface 232 of the third prism 23 faces the second prism 22, and the first exit surface 212 of the first prism 21 faces the third prism 23, so that the first monochromatic light 101 emitted from the first exit surface 212 of the first prism 21 first passes through the third prism 23 to be emitted from the third exit surface 232, and then passes through the second prism 22 to be emitted from the second exit surface 222 of the color combining device 20.

[0071] like Figure 3As shown, the first film system 24, which is used to reflect the second monochromatic light 102, is disposed between the third exit surface 232 of the third prism 23 and the second prism 22, so that the second monochromatic light 102, which is totally reflected by the second exit surface 222 of the second prism 22, can be reflected by the first film system 24 back to the second prism 22 and emitted from the color combining device 20 through the second exit surface 222 of the second prism 22. In other words, the second monochromatic light 102 is first totally reflected when it first propagates to the second exit surface 222 of the second prism 22 and propagates toward the first film system 24, then is reflected when it propagates to the first film system 24 and is reflected back to the second prism 22, and finally is transmitted when it second propagates to the second exit surface 222 of the second prism 22 and is emitted from the second prism 22. That is, the first film system 24 and the second prism 22 cooperate with each other to form a return light path within the second prism 22, so that the second monochromatic light 102 propagates in a return manner within the second prism 22, thereby ensuring that the second monochromatic light 102 has a sufficiently long propagation path within the color combining device 20.

[0072] like Figure 3 As shown, the second film system 25, which is used to reflect the third monochromatic light 103, is disposed between the first exit surface 212 of the first prism 21 and the third prism 23, so that the third monochromatic light 103, which is totally reflected by the third exit surface 232 of the third prism 23, can be reflected by the second film system 25 back to the third prism 23. After emitting from the third exit surface 232 of the third prism 23, the third monochromatic light 103 passes through the second prism 22 and is emitted from the second exit surface 222 of the second prism 22. In other words, the third monochromatic light 103 is first totally reflected when it first propagates to the third exit surface 232 of the third prism 23, and then propagates toward the second film system 25. Then, it is reflected when it propagates to the second film system 25 and is reflected back to the third prism 23. Finally, it is transmitted when it second propagates to the third exit surface 232 of the third prism 23, and then is emitted from the third prism 23. That is to say, the second film system 25 and the third prism 23 cooperate with each other to form a return light path in the third prism 23, so that the third monochromatic light 103 propagates in a return manner in the third prism 23, thereby ensuring that the third monochromatic light 103 has a sufficiently long propagation path in the color combining device 20.

[0073] In summary, if Figure 3As shown, the color combining device 20 can be used to: make the first path of monochromatic light 101 coming from the first light-emitting element 11 and incident from the first incident surface 211 of the first prism 21 pass through the first prism 21, the second film system 25, the third prism 23, the first film system 24 and the second prism 22 in sequence, so as to be emitted from the second exit surface 222 of the second prism 22; make the second path of monochromatic light 102 coming from the second light-emitting element 12 and incident from the second incident surface 221 of the second prism 22 pass through the second prism 22 after being totally reflected by the second exit surface 222 of the second prism 22 and reflected by the first film system 24 in sequence, so as to be emitted from the second exit surface 222 of the second prism 22; and make the second path of monochromatic light 102 coming from the second light-emitting element 12 and incident from the second incident surface 221 of the second prism 22 pass through the second prism 22 after being totally reflected by the second exit surface 222 of the second prism 22 and reflected by the first film system 24 in sequence, so as to be emitted from the second exit surface 222 of the second prism 22; The third monochromatic light 103 that is incident from the third incident surface 231 of the third prism 23 passes through the third prism 23, the second film system 24 and the second prism 22 in sequence after total reflection from the third exit surface 232 of the third prism 23 and reflection from the second film system 25, so as to be emitted from the second exit surface 222 of the second prism 22, and the first monochromatic light 101, the second monochromatic light 102 and the third monochromatic light 103 emitted from the second exit surface 222 of the second prism 22 propagate along the same optical path, so that the first monochromatic light 101, the second monochromatic light 102 and the third monochromatic light 103 emitted from the second exit surface 222 of the second prism 22 are synthesized into one light.

[0074] It is worth noting that in the above examples of the present invention, the first film system 24 can be implemented as, but is not limited to, a red-reflecting film for reflecting red light and transmitting blue and green light. The second film system 25 can be implemented as, but is not limited to, a blue-reflecting film for reflecting blue light and transmitting red and green light. Of course, in other examples of the present invention, the second film system 25 can also be implemented as other types of film systems, such as a green-transmitting film, as long as it can ensure that blue light is reflected and green light is transmitted. Alternatively, the first film system 24 can also be implemented as the blue-reflecting film; accordingly, the second film system 25 is implemented as the red-reflecting film.

[0075] In addition, the angle between the second incident surface 221 and the second exit surface 222 of the second prism 22 is preferably greater than a first critical angle, so that when the second monochromatic light 102 from the second light-emitting element 12 is perpendicularly incident to the second prism 22, that is, the second monochromatic light 102 perpendicularly incident from the second incident surface 221 can undergo total internal reflection at the second exit surface 222 of the second prism 22. It can be understood that it is precisely because the second monochromatic light 102 is perpendicularly incident to the second prism 22 from the second incident surface 221 that the second monochromatic light 102 can propagate in a straight line to the second exit surface 222 of the second prism 22. Therefore, the second monochromatic light 102 is not reflected or refracted at the second incident surface 221 of the second prism 22, which helps to reduce light loss and improve the light energy utilization efficiency of the color combining device 20. In addition, the first critical angle of the present invention is implemented as the minimum incident angle when the light is totally reflected at the second exit surface 222 of the second prism 22 .

[0076] Similarly, the angle between the third incident surface 231 and the third exit surface 222 of the third prism 23 is preferably greater than a second critical angle, so that when the third monochromatic light 103 from the third light-emitting element 13 is perpendicularly incident to the third prism 23, that is, when the third monochromatic light 103 is perpendicular to the third incident surface 231, the third monochromatic light 103 perpendicularly incident from the third incident surface 231 can undergo total internal reflection at the third exit surface 232 of the third prism 23, which helps to reduce the light loss of the third monochromatic light 103 when it enters the third prism 23, thereby improving the light energy utilization efficiency of the color combining device 20. It is understandable that the second critical angle of the present invention is implemented as the minimum incident angle at which light undergoes total internal reflection at the third exit surface 232 of the third prism 23.

[0077] In addition, in this example of the present invention, the angle between the first incident surface 211 and the first exit surface 212 of the first prism 21 is less than a third critical angle to prevent the first path of monochromatic light 101 from the first light-emitting element 11 from vertically incident on the first prism 21, that is, when the first path of monochromatic light 101 is perpendicular to the first incident surface 211, the first path of monochromatic light 101 vertically incident from the first incident surface 211 will not undergo total internal reflection at the first exit surface 212 of the first prism 21, so as to ensure that the first path of monochromatic light 101 can be emitted from the first exit surface 212.

[0078] Preferably, the first incident surface 211 of the first prism 21 is parallel to the second exit surface 222 of the second prism 22, so as to ensure that the first path of monochromatic light 101 perpendicularly incident from the first incident surface 211 can be vertically emitted from the second exit surface 222. In other words, the combined light path defined by the first prism 21 in the color combining device 20 is preferably perpendicular to the second exit surface 222 of the second prism 22, so as to ensure that the first path of monochromatic light 101 propagating along the combined light path is vertically emitted from the second exit surface 222, thereby reducing light energy loss caused by reflection when emitting from the second prism 22.

[0079] It is worth mentioning that in some examples of the present invention, in order to reduce light energy loss caused by reflection, the color combining device 20 of the present invention may further include an anti-reflection film (not shown in the figure), wherein the anti-reflection film can be respectively disposed on the first incident surface 211 of the first prism 21, the second incident surface 221 of the second prism 22, and the third incident surface 231 of the third prism 23, so as to reduce reflection of the first, second, and third monochromatic lights 101, 102, 103 at the corresponding incident surfaces, thereby helping to improve the light energy utilization efficiency of the color combining device 20. Of course, in other examples of the present invention, the anti-reflection film can be selectively disposed on the first exit surface 212 of the first prism 21, the second exit surface 222 of the second prism 22, and the third exit surface 232 of the third prism 23, so as to further reduce light energy loss caused by unnecessary reflection of the first, second, and third monochromatic lights 101, 102, 103.

[0080] According to the above embodiments of the present invention, Figure 3 As shown, the second prism 22 of the color combining device 20 of the present invention further has a second functional surface 223, wherein the second functional surface 223 of the second prism 22 corresponds to the third exit surface 232 of the third prism 23, and the first film system 24 is preferably coated on the second functional surface 223 of the second prism 22, so that the second functional surface 223 of the second prism 22 serves as a partially reflecting surface for reflecting the second monochromatic light 102 at the second functional surface 223 of the second prism 22 and transmitting the first monochromatic light 101 and the third monochromatic light 103 at the second functional surface 223 of the second prism 22. It is understood that in other examples of the present invention, the first film system 24 can also be provided on the second functional surface 223 of the second prism 22 by means such as attachment, and this invention will not be repeated here.

[0081] Preferably, the angle between the second functional surface 223 of the second prism 22 and the second exit surface 222 is equal to half the angle between the second incident surface 221 of the second prism 22 and the second exit surface 22, so that the second monochromatic light 102 perpendicularly incident from the second incident surface 221 can be perpendicularly emitted from the second exit surface 222 after being reflected (via total internal reflection from the second exit surface 222 and reflection from the first film system 24 coated on the second functional surface 223). In other words, the combined light path defined by the second prism 22 in the color combining device 20 is preferably perpendicular to the second exit surface 222 of the second prism 22, to ensure that the second monochromatic light 102 propagating along the combined light path is perpendicularly emitted from the second exit surface 222, thereby reducing light energy loss caused by reflection when exiting the second prism 22.

[0082] Similarly, if Figure 3 As shown, the third prism 23 of the color combining device 20 of the present invention further has a third functional surface 233, wherein the third functional surface 233 of the third prism 23 corresponds to the first exit surface 212 of the first prism 21, and the second film system 25 is preferably coated on the third functional surface 233 of the third prism 23, so that the third functional surface 233 of the third prism 23 serves as a partially reflective surface for reflecting the third monochromatic light 103 at the third functional surface 233 of the third prism 23 and transmitting the first monochromatic light 101 at the third functional surface 233 of the third prism 23. It is understood that in other examples of the present invention, the second film system 25 can also be fixed to the third functional surface 233 of the third prism 23 by methods such as attachment or bonding, which will not be further described in the present invention. Of course, in another example of the present invention, the second film system 25 can also be fixed to the first exit surface 212 of the first prism 21 by methods such as coating or attachment.

[0083] Preferably, the third exit surface 232 of the third prism 23 is parallel to the second functional surface 233 of the second prism 22, and the third path of monochromatic light 103 perpendicularly incident from the third incident surface 231 can be vertically emitted from the second exit surface 222 after being reflected (via total internal reflection from the third exit surface 232 and reflection from the second film system 25 coated on the third functional surface 233). In other words, the combined light path defined by the third prism 23 in the color combining device 20 is preferably perpendicular to the second exit surface 222 of the second prism 22, to ensure that the third path of monochromatic light 103 propagating along the combined light path is vertically emitted from the second exit surface 222, thereby reducing light energy loss caused by reflection when emitting from the second prism 22.

[0084] Furthermore, in one example of the present invention, the second functional surface 223 of the second prism 22 can be superimposed on the third exit surface 232 of the third prism 23 by gluing, so that the first film system 24 is located between the third exit surface 232 of the third prism 23 and the second functional surface 223 of the second prism 22.

[0085] It is worth noting that, since the third emission surface 232 of the third prism 23 faces the first film system 24, and the second functional surface 223 of the second prism 22 and the first film system 24 are sequentially stacked on the third emission surface 232 of the third prism 23, Figure 3 As shown, the color combining device 20 of the present invention preferably further comprises an air gap 230, wherein the air gap 230 is disposed between the third exit surface 232 of the third prism 23 and the first film system 24, so as to ensure that the third path of monochromatic light 103 incident from the third incident surface 231 of the third prism 23 is totally reflected at the third exit surface 232 of the third prism 23. In addition, since the second exit surface 222 of the second prism 22 does not need to be provided with any object, the second exit surface 222 of the second prism 22 can directly face outward. Therefore, the color combining device 20 of the present invention does not need to specifically reserve space outside the second exit surface 222 of the second prism 22, thereby ensuring that the second exit surface 222 of the second prism 22 is implemented as a total reflection surface.

[0086] Preferably, when manufacturing the color combining device 20, adhesive can be applied to the edge of the third exit surface 232 of the third prism 23 to form an adhesive layer located between the third exit surface 232 of the third prism 23 and the first film system 24 and at the edge of the third exit surface 232 after the adhesive is cured, and the air gap 230 located between the third exit surface 232 of the third prism 23 and the first film system 24 and at the middle of the third exit surface 232 is formed, so that the air gap 230 can be reserved between the third exit surface 232 of the third prism 23 and the first film system 24 while the third prism 23 and the first film system 24 are fixedly glued.

[0087] It is understood that in other examples of the present invention, a light-reducing medium may be applied to the third exit surface 232 of the third prism 23, wherein the refractive index of the light-reducing medium is only slightly lower than the refractive index of the third prism 23 (i.e., the light-dense medium), thereby ensuring that the third exit surface 232 of the third prism 23 is implemented as a total internal reflection surface. For example, when the refractive index of the first film system 24 is lower than the refractive index of the third prism 23, the first film system 24 may be coated on the third exit surface 232 of the third prism 23, thereby ensuring that the third path of monochromatic light 103 is totally reflected at the third exit surface 232 of the third prism 23.

[0088] It's worth noting that the emergence of MicroLED display technology has made it possible to miniaturize projection systems and near-eye display devices. First, MicroLEDs are micronized traditional LEDs to form micron-pitch LED arrays, achieving ultra-high pixel density. In other words, MicroLEDs are densely integrated micron-pitch LED arrays, where each LED pixel can be independently addressed and illuminated. In other words, each LED pixel in a MicroLED is self-luminous, and precise control of the intensity of each LED enables image display. In other words, MicroLEDs can directly emit image light. Secondly, in addition to achieving high brightness, ultra-high resolution, color saturation, and high luminous efficiency, MicroLEDs are more importantly unaffected by moisture, oxygen, or high temperatures, offering significant advantages in stability, lifespan, and operating temperature. Furthermore, MicroLEDs consume approximately 10% of the power of LCDs and 50% of the power of OLEDs. Compared to OLEDs, achieving the same display brightness requires only about 10% of the coating area. These advantages of MicroLEDs promise widespread application in micro-projection, particularly near-eye displays, and augmented reality.

[0089] However, the full-colorization of MicroLED has always been a bottleneck hindering its development, because arrays such as RGB require the assembly of red, blue, and green color chips in batches, and hundreds of thousands of LED chips need to be embedded. This places higher demands on the luminous efficiency, wavelength consistency, and yield of LED chips. In addition, the cost of color difference caused by LEDs is also a bottleneck hindering the technology. However, for monochrome MicroLEDs, there will not be many such problems, because the monochrome MicroLEDs can be assembled through flip-chip packaging and driver IC bonding. Therefore, in order to achieve color display of the micro-projection light engine, it is necessary to use a color combining device to combine the image light emitted by monochrome MicroLEDs of different colors.

[0090] According to the above embodiment of the present invention, the first, second, and third light-emitting elements 11, 12, and 13 of the light source unit 10 of the lighting system 1 are preferably implemented as monochrome MicroLEDs of different colors. Of course, in other examples of the present invention, the first, second, and third light-emitting elements 11, 12, and 13 may also be implemented as, but not limited to, various types of arrayed light-emitting elements such as monochrome LCOS, monochrome LCD, monochrome DMD, and monochrome OLED.

[0091] It is worth noting that when the first, second and third light-emitting elements 11, 12, 13 are implemented as green MicroLED, red MicroLED and blue MicroLED respectively, the first, second and third monochromatic lights 101, 102, 103 are implemented as green image light, red image light and blue image light respectively.

[0092] In the above-described embodiment of the present invention, preferably, based on the return light path in the color combining device 20, the sizes of the first prism 21, the second prism 22, and the third prism 23 in the color combining device 20 are matched to each other, so that the optical paths of the first, second, and third monochromatic lights 101, 102, 103 in the color combining device 20 are equal, thereby minimizing aberrations and facilitating improving the projection quality of a projection system equipped with the illumination system 1. It will be understood that the optical path referred to in the present invention is equal to the product of the physical path length of the light and the refractive index of the current propagation medium (e.g., the first, second, and third prisms 21, 22, 23).

[0093] In addition, the positions of the first, second and third light-emitting elements 11, 12, 13 in the light source unit 1 relative to the color combining device 20 can be calibrated so that the first, second and third monochromatic lights 101, 102, 103 can be emitted from the same position and along the same direction on the second exit surface 222 of the second prism 22. That is, the first monochromatic light 101, the second monochromatic light 102 and the third monochromatic light 103 emitted from the second exit surface 222 of the second prism 22 propagate along the same optical path to achieve uniform color, which helps to improve the color projection quality of the projection system equipped with the illumination system 1.

[0094] It is worth mentioning that in the above-mentioned embodiment according to the present invention, since the first monochromatic light 101 propagates in an approximately straight line within the color combining device 20, and the second and third monochromatic lights 102 and 103 propagate in a roundabout way within the color combining device 20, in order to make the optical path lengths of the first, second and third monochromatic lights 101, 102, 103 in the color combining device 20 equal, the size of the first prism 21 of the present invention in the propagation direction of the first monochromatic light 101 is relatively large.

[0095] In order to reduce the size of the first prism 21, Figure 4A and Figure 4B A first variant embodiment of the color combining device 20 of the illumination system 1 according to the above-described embodiment of the present invention is shown, wherein the first prism 21 of the color combining device 20 further has a first functional surface 213. The first functional surface 213 of the first prism 21 is configured to reflect the first monochromatic light 101, such that the first monochromatic light 101 incident from the first incident surface 211 of the first prism 21 is first reflected at the first functional surface 213 and propagates in a folded manner before being emitted from the first exit surface 212 of the first prism 21. In this manner, the first monochromatic light 101 propagates in a folded manner within the color combining device 20, thereby reducing the size of the first prism 21 while ensuring that the optical path of the first monochromatic light 101 in the color combining device 20 remains unchanged, thereby reducing the volume and size of the color combining device 20 and the illumination system 1.

[0096] More specifically, in this variant embodiment of the present invention, as Figure 4BAs shown, the first functional surface 213 of the first prism 21 is a total reflection surface, so that the first path of monochromatic light 101 from the first light-emitting element 11 can first enter from the first incident surface 211 of the first prism 21, and after total reflection at the first functional surface 213 of the first prism 21, it can be emitted from the first exit surface 212 of the first prism 21, so as to realize the return propagation of the first path of monochromatic light 101 in the color combining device 20 by total reflection, thereby ensuring that a sufficiently long optical path is provided for the first path of monochromatic light 101 in the smaller volume of the first prism 21.

[0097] Preferably, the angle between the first incident surface 211 and the first functional surface 213 of the first prism 21 is greater than a third critical angle, so that when the first monochromatic light 101 from the first light-emitting element 11 is incident perpendicularly to the first incident surface 211, the first monochromatic light 101 incident perpendicularly from the first incident surface 211 can undergo total internal reflection at the first functional surface 213 of the first prism 21. It is understood that precisely because the first monochromatic light 101 enters the first prism 21 perpendicularly from the first incident surface 211, the first monochromatic light 101 can propagate in a straight line to the first functional surface 213 of the first prism 21. Therefore, the first monochromatic light 101 does not undergo reflection or refraction at the first incident surface 211 of the first prism 21, which helps reduce light loss and improves the light energy utilization efficiency of the color combining device 20. In addition, the third critical angle of the present invention is implemented as the minimum incident angle when light is totally reflected at the first functional surface 213 of the first prism 21 .

[0098] More preferably, the first prism 21 can be implemented as a total reflection prism, that is, the angle between the first incident surface 211 and the first functional surface 213 of the first prism 21 is equal to 45°, and the first incident surface 211 of the first prism 21 is perpendicular to the first exit surface 212, so that the first path of monochromatic light 101 vertically incident from the first incident surface 211 is emitted vertically from the first exit surface 212 after total reflection through the first functional surface 213, so as to minimize the light energy loss caused by the reflection of the first path of monochromatic light 101 at the first incident surface 211 and the first exit surface 212.

[0099] It is worth noting that the Figure 5A second variant embodiment of the color combining device of the illumination system according to the above embodiment of the present invention is shown. Specifically, compared to the first variant embodiment, the color combining device 20 of the second variant embodiment of the present invention differs in that the color combining device 20 further includes a third film system 26 for reflecting the first monochromatic light 101. The third film system 26 is correspondingly disposed on the first prism 21, so that the first monochromatic light 101 incident from the first incident surface 211 is reflected by the third film system 26 and then emitted from the first exit surface 212.

[0100] In other words, if Figure 5 As shown, the first functional surface 213 of the first prism 21 is not a total internal reflection surface, and the third film system 26 is preferably coated on the first functional surface 213 of the first prism 21, so that the first monochromatic light 101 is not subjected to total internal reflection at the first functional surface 213 of the first prism 21, but is instead subjected to specular reflection. It is understood that in other examples of the present invention, the third film system 26 can also be attached to the first functional surface 213 of the first prism 21 by bonding, attaching, or the like.

[0101] More preferably, the third film system 26 is implemented as a specular reflective film, configured to simultaneously reflect all light, such as the first, second, and third monochromatic lights 101, 102, 103, etc., thereby preventing external light from affecting the color combination of the color combining device 20. Of course, in other examples of the present invention, the third film system 26 may also be implemented as a partial reflective film, such as a green-reflecting film (reflecting green light and transmitting red and blue light), as long as it can reflect the first monochromatic light 101. This will not be further described in the present invention.

[0102] It is worth mentioning that in order to further reduce the volume and weight of the color combining device 20, the attached Figure 6 A third variant embodiment of the color combining device of the lighting system according to the above embodiment of the present invention is shown, wherein the color combining device 20 omits the first prism 21, and the first light-emitting element 11 directly corresponds to the second film system 25. That is, the second film system 25 is located between the first light-emitting element 11 and the third prism 23, so that the first monochromatic light 101 from the first light-emitting element 11 passes through the second film system 25, the third prism 23, the first film system 24 and the second prism 21 in sequence to be emitted from the color combining device 20. Similarly, the first, second and third monochromatic lights 101, 102, 103 of different paths can be combined into one light.

[0103] In other words, if Figure 6As shown, the first film system 24 is located between the second prism 22 and the third prism 23, and the third prism 23 is located between the second film system 25 and the first film system 24, wherein the first light-emitting element 11, the second light-emitting element 12 and the third light-emitting element 13 correspond to the second film system 25, the second prism 22 and the third prism 23 respectively.

[0104] In this way, Figure 6 As shown, the first monochromatic light 101 from the first light-emitting element 11 can sequentially pass through the second film system 25, the third prism 23, the first film system 24, and the second prism 24 to be emitted from the color combining device 20; the second monochromatic light 102 from the second light-emitting element 12 first undergoes total reflection in the second prism 22 to propagate to the first film system 24, and after being reflected back to the second prism 22 by the first film system 24, it then passes through the second prism 22 to be emitted from the color combining device 20; the third monochromatic light 103 from the third light-emitting element 13 first undergoes total reflection in the third prism 23 to propagate to the second film system 25, and after being reflected back to the third prism 23 by the second film system 24, it passes through the third prism 23, the first film system 24 and the second prism 24 in sequence and is emitted from the color combining device 20, and the first path of monochromatic light 101, the second path of monochromatic light 102 and the third path of monochromatic light 103 emitted from the color combining device 20 are propagated along the same optical path, so that the first path of monochromatic light 101 from the first light-emitting element 11, the second path of monochromatic light 102 from the second light-emitting element 12 and the third path of monochromatic light 103 from the third light-emitting element 13 are combined into a path of combined color light (such as colored light) in the color combining device 20.

[0105] It can be understood that in this variant embodiment of the present invention, although the weight and volume of the color combining device 20 are greatly reduced because the color combining device 20 does not include the first prism 21, the optical path of the first monochromatic light 101 propagating in the color combining device 20 is also reduced. Therefore, compared with the above-mentioned embodiment of the present invention, in the lighting system 1 according to the third variant embodiment of the present invention: the straight-line distance between the first light-emitting element 11 and the third prism 23 has to be increased to ensure that the optical paths of the first, second and third monochromatic lights 101, 102, 103 in the lighting system 1 remain consistent.

[0106] It is worth noting that in other variations of the present invention, the color combining device 20 may also use a reflector instead of the first prism 21 in the color combining device 20 according to the first variation of the present invention. The reflector is used to reflect the first monochromatic light 101 from the first light-emitting element 11, so that the reflected first monochromatic light 101 propagates toward the second film system 25 and sequentially passes through the second film system 25, the third prism 23, the first film system 24, and the second prism 24 before exiting the color combining device 20. Similarly, the first monochromatic light 101, the second monochromatic light 102, and the third monochromatic light 103 exiting the color combining device 20 can propagate along the same optical path. It will be appreciated that in this example of the present invention, the color combining device 20 uses the reflector to change the propagation direction of the first monochromatic light 101, thereby shortening the straight-line distance between the first light-emitting element 11 and the third prism 23, thereby helping to reduce the overall volume of the lighting system 1.

[0107] According to another aspect of the present invention, the present invention further provides a color combining method for combining three monochromatic lights into one light. Specifically, Figure 7 As shown, the color combining method comprises the steps of:

[0108] S100: Totally reflecting the second monochromatic light 102 and the third monochromatic light 103 respectively to change the propagation directions of the second monochromatic light 102 and the third monochromatic light 103; and

[0109] S200: Reflecting the second monochromatic light 102 and the third monochromatic light 103 after being totally reflected respectively to change the propagation directions of the second monochromatic light 102 and the third monochromatic light 103 again, so that the second monochromatic light 102 and the third monochromatic light 103 propagate along the same optical path as the first monochromatic light 101 at the same time after being turned twice.

[0110] It is worth noting that Figure 7 As shown, in another example of the present invention, the color combining method further comprises the steps of:

[0111] S300: Reflecting the first monochromatic light 101 to change the propagation direction of the first monochromatic light 101 so that the second monochromatic light 102 and the third monochromatic light 103 propagate along the same optical path as the reflected first monochromatic light 101 after being turned twice.

[0112] Those skilled in the art will appreciate that the embodiments of the present invention described above and shown in the accompanying drawings are intended to be illustrative only and are not intended to limit the present invention. The objectives of the present invention have been fully and effectively achieved. The functional and structural principles of the present invention have been demonstrated and illustrated in the embodiments. Any variations or modifications may be made to the embodiments of the present invention without departing from the principles described.

Claims

1. A color combining device for combining a first monochromatic light, a second monochromatic light and a third monochromatic light into a single light, characterized in that: The color combining device has a color combining light path and includes: a second prism, configured to totally reflect the second monochromatic light incident on the second prism; a third prism, configured to totally reflect the third path of monochromatic light incident upon the third prism; a first film system, wherein the first film system is configured to reflect the second monochromatic light and transmit the first monochromatic light and the third monochromatic light, wherein the first film system is located between the second prism and the third prism, and the first film system is configured to reflect the second monochromatic light totally reflected by the second prism back to the second prism, so that the second monochromatic light propagates along the combined color light path after passing through the second prism; and a second film system, wherein the second film system is configured to reflect the third monochromatic light and transmit the first monochromatic light, wherein the third prism is located between the second film system and the first film system, wherein the second film system is configured to reflect the third monochromatic light that has been totally reflected by the third prism back to the third prism, so that the third monochromatic light propagates along the combined color light path after sequentially passing through the third prism, the first film system, and the second prism, and the second film system is further configured to transmit the first monochromatic light to the third prism, so that the first monochromatic light propagates along the combined color light path after sequentially passing through the second film system, the third prism, the first film system, and the second prism; The color combining device further includes a first prism, wherein the second film system is located between the first prism and the third prism, and is configured to allow the first path of monochromatic light to propagate along the color combining light path after sequentially passing through the first prism, the second film system, the third prism, the first film system, and the second prism; The first prism has a first incident surface and a first exit surface, and the first exit surface of the first prism faces the second film system, so that the first path of monochromatic light incident from the first incident surface is emitted from the first exit surface after passing through the first prism to be emitted to the second film system; In which, the color combining device further includes a third film system, wherein the third film system is used to reflect the first monochromatic light, and the third film system is correspondingly arranged on the first prism, for reflecting the first monochromatic light incident from the first incident surface, so that the reflected first monochromatic light is emitted from the first exit surface; the third film system is a mirror reflection film arranged on the first functional surface of the first prism.

2. The color combining device according to claim 1, wherein: The second prism has a second incident surface and a second exit surface, wherein the second exit surface of the second prism serves as a total reflection surface for totally reflecting the second monochromatic light incident from the second incident surface, so that the second monochromatic light after total reflection is emitted toward the first film system.

3. The color combining device according to claim 2, wherein: The second prism further has a second functional surface, wherein the second functional surface of the second prism faces the third prism, and the first film is coated on the second functional surface of the second prism.

4. The color combining device according to claim 3, wherein: The third prism has a third incident surface and a third exit surface, wherein the third exit surface of the third prism serves as a total reflection surface, and the third exit surface of the third prism corresponds to the second functional surface of the second prism, and is used to totally reflect the third monochromatic light incident from the third incident surface, so that the third monochromatic light after total reflection is emitted toward the second film system.

5. The color combining device according to claim 4, wherein: The third prism further has a third functional surface, wherein the third functional surface of the third prism corresponds to the first emission surface of the first prism, and the second film is coated on the third functional surface of the third prism. 6 . The color combining device as claimed in claim 4 , further comprising an air gap, wherein the air gap is located between the third exit surface of the third prism and the first film system.

7. The color combining device as claimed in claim 6, further comprising an anti-reflection film, wherein the anti-reflection film is respectively provided on the first incident surface and the first exit surface of the first prism, the second incident surface of the second prism, and the third incident surface of the third prism.

8. The color combining device according to claim 1, wherein: The first film is a red light reflecting film or a blue light reflecting film, and the second film is correspondingly the blue light reflecting film or the red light reflecting film.

9. A lighting system, characterized in that include: A light source unit, wherein the light source unit comprises: a first light-emitting element, configured to emit a first path of monochromatic light; a second light-emitting element, configured to emit a second path of monochromatic light; and a third light-emitting element, configured to emit a third path of monochromatic light; and The color combining device according to any one of claims 1 to 8, wherein the light source unit is correspondingly arranged on the light incident side of the color combining device, and the color combining device has a color combining light path for combining three paths of monochromatic light provided by the light source unit into one path of light propagating along the color combining light path.

10. The lighting system according to claim 9, wherein The sizes of the first prism, the second prism and the third prism in the color combining device match each other so as to make the optical paths of the first monochromatic light, the second monochromatic light and the third monochromatic light in the color combining device the same.

11. The lighting system according to claim 9, wherein The first light-emitting element, the second light-emitting element, and the third light-emitting element are respectively single-color MicroLEDs of different colors.

12. A color combining method, characterized in that: The color combining device according to any one of claims 1 to 8 comprises the steps of: Totally reflecting the second monochromatic light and the third monochromatic light respectively to change the propagation directions of the second monochromatic light and the third monochromatic light; Respectively reflecting the second monochromatic light and the third monochromatic light after being totally reflected, so as to change the propagation directions of the second monochromatic light and the third monochromatic light again, so that the second monochromatic light and the third monochromatic light propagate along the same optical path as the first monochromatic light at the same time after being turned twice; and The first monochromatic light is reflected by the mirror reflection film in the color combining device to change the propagation direction of the first monochromatic light, so that the second monochromatic light and the third monochromatic light are propagated along the same optical path as the reflected first monochromatic light after being turned twice.

Images