Polarized light conversion element, light combination system and projection equipment

Abstract

The invention relates to the technical field of display, and discloses a polarized light conversion element, a light combination system and projection equipment, in the embodiment, light guide layers and phase conversion layers with different characteristics are arranged in all areas of the polarized light conversion element, all area spaces of the polarized light conversion element are fully utilized, and the light utilization rate is improved; therefore, the polarization conversion element provided by the embodiment can improve the brightness of the projection equipment.

Description

Technical Field

[0001] The present application relates to the field of projection display technology, and in particular to a polarization conversion element, a light combining system and a projection device. Background Art

[0002] In the light combining system of the projection device, the polarization conversion element is located between the light source device and the spatial light modulation component. After converting the light generated by the light source device into s-wave or p-wave polarized light, it acts on the spatial light modulation component to generate a projection image. However, in the current light combining system based on the polarization conversion element, there is a lot of idle space between the areas used for polarization light conversion in the polarization conversion element, resulting in low light utilization. Summary of the invention

[0003] The present application provides a polarization conversion element for a light combining system. The light combining system can be used in a projection device, can improve the brightness of the projection device, and can improve the color gamut of the projection device due to the addition of at least one second light source.

[0004] In a first aspect, the present application provides a polarization conversion element, the polarization conversion element includes at least one conversion zone, the target conversion zone includes at least one light guide layer and at least one phase conversion layer, and the target conversion zone is any one of the at least one conversion zone;

[0005] The first polarized light in the first light incident on the target conversion area is guided by at least one light guide layer and then emitted from the polarization conversion element, and the second polarized light in the first light is converted into the first polarized light by at least one phase conversion layer after passing through at least one light guide layer and at least one phase conversion layer and then emitted;

[0006] At least one second light incident on the target conversion zone is guided by at least one light guiding layer and then emitted from the polarization conversion element; or, the first polarized light among at least one second light incident on the target conversion zone is guided by at least one light guiding layer and then emitted from the polarization conversion element, and the second polarized light among at least one second light passes through at least one light guiding layer and at least one phase conversion layer, is converted into the first polarized light by at least one phase conversion layer and then emitted.

[0007] In some embodiments, at least one light guiding layer includes a first polarization splitting layer and a first light guiding layer, and at least one phase conversion layer includes a first phase conversion layer;

[0008] The target light is incident on the first polarization splitting layer;

[0009] The first polarized light in the target light is transmitted through the first polarization splitting layer and then emitted, the second polarized light in the target light is reflected by the first polarization splitting layer to the first light guiding layer, guided to the first phase conversion layer by the first light guiding layer, converted to the first polarized light by the first phase conversion layer and then emitted;

[0010] Alternatively, the first polarized light in the target light is reflected by the first polarization splitting layer to the first light guiding layer, and is guided by the first light guiding layer before being emitted; the second polarized light in the target light is transmitted through the first polarization splitting layer and then incident on the first phase conversion layer, and is converted into the first polarized light by the first phase conversion layer before being emitted;

[0011] Alternatively, the first polarized light in the target light is emitted after passing through the first polarization splitting layer, and the second polarized light in the target light is reflected to the first phase conversion layer, converted into the first polarized light by the first phase conversion layer, and then incident on the first light guiding layer, and then emitted after being guided by the first light guiding layer;

[0012] The target light is the first light, or the first light and at least one second light, or the first light and the target second light, and the target second light is any one of the at least one second light.

[0013] In some embodiments, when only the first light is incident on the first polarization splitting layer, the first light guiding layer is a reflective layer or a dichroic layer, and at least one light guiding layer further includes a second light guiding layer;

[0014] The target second light is incident on the reflective layer or the dichroic layer, reflected by the reflective layer or the dichroic layer to the second light guiding layer, and then emitted after being guided by the second light guiding layer.

[0015] In some embodiments, when only the first light is incident on the first polarization splitting layer, the first light guiding layer includes a polarization splitting sublayer and a dichroic sublayer, and the dichroic sublayer reflects the first light and transmits the target second light; at least one light guiding layer also includes a second light guiding layer, and at least one phase conversion layer includes a second phase conversion layer;

[0016] The target second light is incident on the first light guiding layer, the first polarized light in the target second light is transmitted through the polarization photonic layer and the dichroic layer and is emitted from the polarization conversion element, the second polarized light in the target second light is reflected by the polarization photonic layer to the second phase conversion layer, is converted into the first polarized light by the second phase conversion layer, and is incident on the second light guiding layer, and is emitted after being guided by the second light guiding layer.

[0017] In some embodiments, when only the first light is incident on the first polarization splitting layer, the first light guiding layer reflects the first light and transmits the target second light, and at least one light guiding layer includes a second polarization splitting layer, a second light guiding layer, and a second phase conversion layer;

[0018] The first polarized light in the target second light is reflected by the second polarization splitting layer to the second light guiding layer, and is emitted after being guided by the second light guiding layer; the second polarized light in the target second light passes through the polarization splitting layer and enters the second phase conversion layer, is converted into the first polarized light by the second phase conversion layer, and then enters the first light guiding layer, and is emitted after passing through the first light guiding layer.

[0019] In some embodiments, a light combining element is respectively provided corresponding to the first light emitted from the polarization conversion element and the at least one second light, and the first light emitted from the polarization conversion element is combined into a beam of light and then emitted, and various second lights among the at least one second light emitted from the polarization conversion element are respectively combined into a beam of light and then emitted.

[0020] In some embodiments, when the polarization conversion element includes two or more conversion regions, the second light guiding layer is used to reflect the target second light and transmit the first light.

[0021] In some embodiments, the second light is supplementary light for the first light, and a wavelength band belonging to the target primary color light exists in the wavelength band of the first light and the wavelength band of the supplementary light.

[0022] In some embodiments, at least one light guiding layer includes a first light guiding layer, a second light guiding layer, and a phase conversion layer;

[0023] The first light is incident on the first light guiding layer from the first side of the polarization conversion element, and the first polarized light in the first light is reflected by the first light guiding layer and then emitted from the polarization conversion element; the second polarized light in the first light is incident on the phase conversion layer after passing through the first light guiding layer, and after being converted into the first polarized light by the phase conversion layer, it is incident on the second light guiding layer, and then emitted after being guided by the second light guiding layer; at least one kind of supplementary light is incident on the first light guiding layer from the second side of the polarization conversion element, and is emitted through the first light guiding layer, the phase conversion layer, and the second light guiding layer;

[0024] Alternatively, the first light is incident on the first light guiding layer from the second side of the polarization conversion element, and the first polarized light in the first light is transmitted through the first light guiding layer and then emitted from the polarization conversion element; the second polarized light in the first light is reflected by the first light guiding layer and then incident on the phase conversion layer, and after being converted into the first polarized light by the phase conversion layer, it is incident on the second light guiding layer, and then emitted after being guided by the second light guiding layer; at least one kind of supplementary light is incident on the first light guiding layer from the first side of the polarization conversion element, and then emitted after being reflected by the first light guiding layer;

[0025] Alternatively, at least one light guiding layer also includes a third guiding layer, the first light is incident on the third light guiding layer from the second side of the polarization conversion element, the first polarized light in the first light is reflected by the third light guiding layer to the second light guiding layer, and is emitted after being guided by the second light guiding layer; the second polarized light in the target light is incident on the phase conversion layer after passing through the third guiding layer, and is converted into the first polarized light by the phase conversion layer and is emitted after passing through the first light guiding layer; at least one supplementary light is incident on the first light guiding layer from the first side of the polarization conversion element, and is emitted after being reflected by the first light guiding layer.

[0026] In some embodiments, when the polarization conversion element includes an even number of conversion regions, each conversion region is symmetrical with respect to the central axis of the polarization conversion element.

[0027] In some embodiments, a quadrangular prism and / or a triangular prism is disposed between at least one light guiding layer and at least one phase conversion layer, between at least one light guiding layer, and between at least one phase conversion layer;

[0028] Alternatively, at least one light guiding layer and at least one phase conversion layer are fixed by a fixing member.

[0029] In a second aspect, the present application also provides a light combining system, which includes a light source device, a collimating element, a polarization conversion element of any one of the first aspects, a uniform light element and a spatial light modulation component, and the light source device is used to generate a first light and at least one second light.

[0030] In some embodiments, if the first light includes a first color light, a second color light, and a third color light, the spatial light modulation component includes a first liquid crystal modulation element corresponding to the first color light, a second liquid crystal modulation element corresponding to the second color light, and a third liquid crystal modulation element corresponding to the third color light;

[0031] The light combining system includes at least one of a polarization conversion element corresponding to the first liquid crystal modulation element, a polarization conversion element corresponding to the second liquid crystal modulation element, and a polarization conversion element corresponding to the third liquid crystal modulation element.

[0032] In some embodiments, the light source device includes at least one light emitting unit, a substrate, and a reflective dam, wherein the reflective dam is disposed on a side surface of the at least one light emitting unit.

[0033] In some embodiments, the light source device includes a light emitting unit array including a plurality of light emitting units, and the reflective dam is disposed around the periphery of the light emitting unit array.

[0034] In a third aspect, the present application provides a projection device, comprising a light combining system as described in any one of the second aspect and possible implementations of the second aspect.

[0035] In the present application, by setting light guiding layers and phase conversion layers with different characteristics in each area of ​​the polarization conversion element, all regional spaces of the polarization conversion element are fully utilized to improve the utilization rate of light, thereby improving the brightness of the projection device; and supplementary light can be injected into certain areas to make the color gamut better; therefore, the polarization conversion element provided in the present application can improve the brightness and color gamut of the projection device. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The above and other purposes, features and advantages of the present application will become more apparent by describing the embodiments of the present application in more detail in conjunction with the accompanying drawings. The accompanying drawings are used to provide a further understanding of the embodiments of the present application and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the present application and do not constitute a limitation of the present application. In the accompanying drawings, the same reference numerals generally represent the same components or steps. Among them:

[0037] Figure 1 is a schematic structural diagram of a polarization conversion element in one embodiment of the present application;

[0038] Figure 2 is a schematic structural diagram of a polarization conversion element in another embodiment of the present application;

[0039] Figure 3 is a schematic structural diagram of a polarization conversion element in another embodiment of the present application;

[0040] Figure 4 is a schematic structural diagram of a polarization conversion element in another embodiment of the present application;

[0041] Figure 5 is a schematic structural diagram of a polarization conversion element in another embodiment of the present application;

[0042] Figure 6 is a schematic structural diagram of a polarization conversion element in another embodiment of the present application;

[0043] Figure 7 is a schematic structural diagram of a polarization conversion element in another embodiment of the present application;

[0044] Figure 8 is a schematic structural diagram of a polarization conversion element in another embodiment of the present application;

[0045] Fig. 9 is a schematic structural diagram of a light combining system in one embodiment of the present application;

[0046] Fig.10 is a schematic structural diagram of a light combining system in another embodiment of the present application;

[0047] Fig.11 It is a schematic diagram of the structure of a projection device in one embodiment of the present application. DETAILED DESCRIPTION

[0048] In order to make those skilled in the art better understand the technical solutions in the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without making creative work should belong to the scope of protection of the present application. In addition, although the disclosure in the present application is introduced according to one or several exemplary examples, it should be understood that each aspect of these disclosures can also constitute a complete technical solution separately. In the absence of conflict, the following embodiments and the features in the embodiments can be combined with each other.

[0049] In the embodiments of the present application, words such as "exemplarily" and "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary" in the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of the word "exemplary" is intended to present concepts in a concrete way.

[0050] Unless otherwise defined, the technical terms or scientific terms used in this application should be understood by people with ordinary skills in the field to which this application belongs. "First", "second" and similar words used in this application do not indicate any order, quantity or importance, but are only used to distinguish descriptions. "Include" or "comprising" and similar words mean that the elements or objects appearing before the word cover the elements or objects listed after the word and their equivalents, without excluding other elements or objects. The term "and / or" includes any and all combinations of one or more associated listed items.

[0051] In order to thoroughly understand the present application, a detailed description will be provided below to illustrate the technical solution of the present application. The preferred embodiments of the present application are described in detail below, but in addition to these detailed descriptions, the present application may also have other implementation methods.

[0052] This embodiment provides a polarization conversion element, the polarization conversion element includes at least one conversion area, the target conversion area includes at least one light guide layer and at least one phase conversion layer, and the target conversion area is any one of the at least one conversion area;

[0053] The first polarized light in the first light incident on the target conversion area is guided by at least one light guide layer and then emitted from the polarization conversion element, and the second polarized light in the first light is converted into the first polarized light by at least one phase conversion layer after passing through at least one light guide layer and at least one phase conversion layer and then emitted;

[0054] At least one second light incident on the target conversion zone is guided by at least one light guiding layer and then emitted from the polarization conversion element; or, the first polarized light among at least one second light incident on the target conversion zone is guided by at least one light guiding layer and then emitted from the polarization conversion element, and the second polarized light among at least one second light passes through at least one light guiding layer and at least one phase conversion layer, is converted into the first polarized light by at least one phase conversion layer and then emitted.

[0055] The first light may be red light, green light, blue light, etc. Optionally, the second light may be supplementary light for the first light, and there is a band belonging to the target primary color light in the band of the first light and the band of the supplementary light; for example, the target primary color light may be red light, green light, and blue light, the red light band is 625-740nm, the green light band is 490-580nm, and the blue light band is 440-475nm; the supplementary light band may be any one of 430-680um, such as 450-680um or 570-640um. Optionally, the first light and at least one second light include at least red light, green light, and blue light.

[0056] There is no limitation on the first polarized light and the second polarized light. For example, the first polarized light may be P light and the second polarized light may be S light.

[0057] Optionally, a prism and / or a prism are arranged between at least one light guiding layer and at least one phase conversion layer, between at least one light guiding layer, and between at least one phase conversion layer; wherein, the number of prisms and prisms is not limited; the light guiding layer can be a reflective film, a dichroic film, a polarization splitting film, etc., which are directly coated on the prism and / or the prism, or a reflective film, a dichroic film, a polarization splitting film, etc. are coated on a transparent substrate and then combined with the prism and / or the prism; the phase conversion layer can be a half-wave plate.

[0058] Optionally, at least one light guide layer and at least one phase conversion layer are fixed by a fixing member; the light guide layer can be a reflective film, a dichroic film, a polarization splitter film, etc. plated on a transparent substrate, and the phase conversion layer can be a half-wave plate; for example, one end of each light guide layer and each phase conversion layer can be embedded in a recessed portion of a fixing member (not shown). The following description is only based on the example of a quadrangular prism and / or a triangular prism.

[0059] In some embodiments, at least one light guiding layer includes a first polarization splitting layer and a first light guiding layer, and at least one phase conversion layer includes a first phase conversion layer; the target light is incident on the first polarization splitting layer; the first polarization light in the target light is transmitted through the first polarization splitting layer and then emitted, the second polarization light in the target light is reflected by the first polarization splitting layer to the first light guiding layer, guided to the first phase conversion layer via the first light guiding layer, converted into the first polarization light via the first phase conversion layer and then emitted; wherein the target light is the first light and at least one second light, or the first light and the target second light, and the target second light is any one of the at least one second light.

[0060] In some embodiments, at least one light guiding layer includes a first polarization splitting layer and a first light guiding layer, and at least one phase conversion layer includes a first phase conversion layer; the first polarized light in the target light is reflected by the first polarization splitting layer to the first light guiding layer, and is emitted after being guided by the first light guiding layer; the second polarized light in the target light is transmitted through the first polarization splitting layer and then incident on the first phase conversion layer, and is converted into the first polarized light by the first phase conversion layer and then emitted; wherein the target light is the first light and at least one second light, or the first light and the target second light.

[0061] In some embodiments, at least one light guiding layer includes a first polarization splitting layer and a first light guiding layer, and at least one phase conversion layer includes a first phase conversion layer; the first polarized light in the target light is emitted after passing through the first polarization splitting layer, and the second polarized light in the target light is reflected to the first phase conversion layer, converted into the first polarized light by the first phase conversion layer, and then incident on the first light guiding layer, and then emitted after being guided by the first light guiding layer; wherein the target light is the first light and at least one second light, or the first light and the target second light.

[0062] In some embodiments, when only the first light is incident on the first polarization beam splitting layer, the first light guiding layer is a reflective layer or a dichroic layer, and at least one light guiding layer also includes a second light guiding layer; the target second light is incident on the reflective layer or the dichroic layer, and is reflected by the reflective layer or the dichroic layer to the second light guiding layer, and is guided by the second light guiding layer before being emitted. The reflective layer may be a reflective film or a double-sided reflective mirror; or the dichroic layer may reflect the first light and at least one second light.

[0063] Optionally, the first light is incident on the polarization splitting layer; the first polarized light in the first light is emitted after passing through the polarization splitting layer, the second polarized light in the first light is reflected by the polarization splitting layer to the first light guiding layer, guided to the first phase conversion layer via the first light guiding layer, converted into the first polarized light via the first phase conversion layer, and then emitted.

[0064] For example, Figure 1 FIG. 1 is a schematic diagram of the structure of a polarization conversion element provided in this embodiment. Figure 1As shown, a target conversion area of ​​the polarization conversion element 10 includes a first polarization splitting layer 10, a first phase conversion layer 20, a first light guiding layer 30, and a second light guiding layer 40; Figure 1 The number of the four prisms and three prisms is only for example. Assume that the first light is red light R(p,s), and the at least one second light includes only one supplementary light, which is yellow light Y(p,s); the first polarization beam splitting layer 10 can transmit P light and reflect S light; the first light guiding layer 30 is a reflective film or a dichroic film, which is used to reflect red light and yellow light, and the two do not include the same wavelength band; the second light guiding layer 40 is a dichroic film, which is used to transmit red light and reflect yellow light.

[0065] The red light R(p, s) is incident on the first polarization beam splitting layer 10; the first polarization light R(p) in the red light R(p, s) is transmitted through the first polarization beam splitting layer 10 and then emitted; the second polarization light R(s) in the red light R(p, s) is reflected by the first polarization beam splitting layer 10 to the first light guiding layer 30, reflected by the first light guiding layer 30 to the first phase conversion layer 20, and then emitted after being converted into the first polarization light R(p) by the first phase conversion layer 20. The yellow light Y(p, s) is incident on the first light guiding layer 30, reflected by the first light guiding layer 30 to the second light guiding layer 40, and then emitted after being guided by the second light guiding layer 40.

[0066] Optionally, the first light is incident on the polarization splitting layer; the first polarized light in the first light is reflected by the polarization splitting layer to the first light guiding layer, and is emitted after being guided by the first light guiding layer; the second polarized light in the first light is incident on the first phase conversion layer after passing through the polarization splitting layer, and is converted into the first polarized light by the first phase conversion layer and is emitted.

[0067] For example, Figure 2 A schematic diagram of the structure of a polarization conversion element provided in this embodiment. Figure 1 Compared with the polarization conversion element shown, Figure 2 The polarization conversion element shown changes the position of the first phase conversion layer 20, setting it in a position parallel to the first polarization splitting layer 10, and the rest remains unchanged.

[0068] Among them, the red light R(p, s) is incident on the first polarization splitting layer 10; the first polarized light R(p) in the red light R(p, s) is reflected by the first polarization splitting layer 10 to the first light guiding layer 30, and is emitted after being reflected by the first light guiding layer 30; the second polarized light R(s) in the red light R(p, s) is transmitted through the first polarization splitting layer 10 and then incident on the first phase conversion layer 20, and is converted into the first polarized light R(p) by the first phase conversion layer 20 and then emitted.

[0069] Optionally, the first light is incident on the polarization splitting layer; the first polarized light in the first light is emitted after passing through the polarization splitting layer, the second polarized light in the first light is reflected to the first phase conversion layer, converted into the first polarized light by the first phase conversion layer, and then incident on the first light guiding layer, and then emitted after being guided by the first light guiding layer.

[0070] For example, Figure 3 A schematic diagram of the structure of a polarization conversion element provided in this embodiment. Figure 1 Compared with the polarization conversion element shown, Figure 3 The polarization conversion element shown changes the position of the first phase conversion layer 20, which is set at a position 30 between the first polarization splitting layer 10 and the first light guiding layer, and the rest remains unchanged.

[0071] Among them, the red light R(p, s) is incident on the first polarization splitting layer 10; the first polarized light R(p) in the red light R(p, s) is emitted after passing through the first polarization splitting layer 10, and the second polarized light R(s) in the red light R(p, s) is reflected to the first phase conversion layer 20, converted into the first polarized light R(p) by the first phase conversion layer 20, and then incident on the first light guiding layer 30, and then emitted after being guided by the first light guiding layer 30.

[0072] In some embodiments, when only the first light is incident on the first polarization splitting layer, the first light guiding layer includes a polarization splitting sublayer and a dichroic sublayer, and the dichroic sublayer reflects the first light and transmits the target second light; at least one light guiding layer also includes a second light guiding layer, and at least one phase conversion layer includes a second phase conversion layer;

[0073] The target second light is incident on the first light guiding layer, the first polarized light in the target second light is transmitted through the polarization photonic layer and the dichroic layer and is emitted from the polarization conversion element, the second polarized light in the target second light is reflected by the polarization photonic layer to the second phase conversion layer, is converted into the first polarized light by the second phase conversion layer, and is incident on the second light guiding layer, and is emitted after being guided by the second light guiding layer.

[0074] Optionally, the first light is incident on the polarization splitting layer; the first polarized light in the first light is reflected by the polarization splitting layer to the first light guiding layer, and is emitted after being guided by the first light guiding layer; the second polarized light in the first light is incident on the first phase conversion layer after passing through the polarization splitting layer, and is converted into the first polarized light by the first phase conversion layer and is emitted.

[0075] Optionally, the first light is incident on the polarization splitting layer; the first polarized light in the first light is emitted after passing through the polarization splitting layer, the second polarized light in the first light is reflected to the first phase conversion layer, converted into the first polarized light by the first phase conversion layer, and then incident on the first light guiding layer, and then emitted after being guided by the first light guiding layer.

[0076] For example, Figure 4FIG. 1 is a schematic diagram of the structure of a polarization conversion element provided in this embodiment. Figure 4 As shown, a target conversion area of ​​the polarization conversion element 10 includes a first polarization splitting layer 10, a first phase conversion layer 20, a first light guiding layer 30, and a second light guiding layer 40; Figure 4 The number of the four prisms and three prisms is only for example. Assume that the first light is red light R(p, s), the at least one second light includes only one supplementary light, which is yellow light Y(p, s); the first polarization splitting layer 10 can transmit P light and reflect S light; the first light guiding layer 30 includes a polarization splitting sublayer and a dichroic sublayer, and the dichroic sublayer is used to reflect red light and transmit yellow light; the second light guiding layer 40 is a dichroic film, and the dichroic film is used to transmit red light and reflect yellow light.

[0077] The red light R(p, s) is incident on the first polarization splitting layer 10; the first polarized light R(p) in the red light R(p, s) is reflected by the first polarization splitting layer 10 to the first light guiding layer 30, and is emitted after being reflected by the first light guiding layer 30; the second polarized light R(s) in the red light R(p, s) is transmitted through the first polarization splitting layer 10 and then incident on the first phase conversion layer 20, and is converted into the first polarized light R(p) by the first phase conversion layer 20 and then is emitted.

[0078] The yellow light Y(p, s) is incident on the first optical guiding layer, the first polarized light Y(p) in the yellow light Y(p, s) is transmitted through the polarization photonic layer and the dichroic layer and is emitted from the polarization conversion element, the second polarized light Y(s) in the yellow light Y(p, s) is reflected by the polarization photonic layer 120 to the second phase conversion layer 50, is converted into the first polarized light Y(p) by the second phase conversion layer 50, and is incident on the second optical guiding layer 40, and is emitted after being reflected by the second optical guiding layer 40.

[0079] Figure 4 The polarization conversion element 10 shown is also applicable to a scenario where the first light is red light R(p, s) and the at least one second light includes blue light B(p, s) and green light G(p, s).

[0080] In some embodiments, when only the first light is incident on the first polarization splitting layer, the first light guiding layer reflects the first light and transmits the target second light, and at least one light guiding layer includes a second polarization splitting layer, a second light guiding layer, and a second phase conversion layer;

[0081] The first polarized light in the target second light is reflected by the second polarization splitting layer to the second light guiding layer, and is emitted after being guided by the second light guiding layer; the second polarized light in the target second light passes through the polarization splitting layer and enters the second phase conversion layer, is converted into the first polarized light by the second phase conversion layer, and then enters the first light guiding layer, and is emitted after passing through the first light guiding layer.

[0082] Optionally, the first light is incident on the polarization splitting layer; the first polarized light in the first light is emitted after passing through the polarization splitting layer, the second polarized light in the first light is reflected to the first phase conversion layer, converted into the first polarized light by the first phase conversion layer, and then incident on the first light guiding layer, and then emitted after being guided by the first light guiding layer.

[0083] Optionally, the first light is incident on the polarization splitting layer; the first polarized light in the first light is reflected by the polarization splitting layer to the first light guiding layer, and is emitted after being guided by the first light guiding layer; the second polarized light in the first light is incident on the first phase conversion layer after passing through the polarization splitting layer, and is converted into the first polarized light by the first phase conversion layer and is emitted.

[0084] For example, Figure 5 FIG. 1 is a schematic diagram of the structure of a polarization conversion element provided in this embodiment. Figure 5 As shown, a target conversion area of ​​the polarization conversion element 10 includes a first polarization splitting layer 10, a first phase conversion layer 20, a first optical guide layer 30, a second polarization splitting layer 40, a second optical guide layer 50, a second phase conversion layer 60, a second polarization splitting layer 80, a second optical guide layer 90, and a second phase conversion layer 70. Assuming that the first light is red light R (p, s), at least one second light includes blue light B (p, s) and green light G (p, s); the first polarization splitting layer 10, the second polarization splitting layer 40 and the second polarization splitting layer 80 can transmit P light and reflect S light; the first optical guide layer 30 is used to reflect red light and transmit green light; the second optical guide layer 50 is used to reflect green light and transmit blue light, and the second optical guide layer 90 is used to reflect blue light, or reflect blue light and transmit red light.

[0085] The red light R(p, s) is incident on the first polarization splitting layer 10; the first polarized light R(p) in the red light R(p, s) is emitted after passing through the first polarization splitting layer 10, and the second polarized light R(s) in the red light R(p, s) is reflected to the first phase conversion layer 20, converted into the first polarized light R(p) by the first phase conversion layer 20, and then incident on the first light guiding layer 30, and then emitted after being guided by the first light guiding layer 30.

[0086] The first polarized light G(p) in the green light G(p,s) is reflected by the second polarization splitting layer 40 to the second optical guiding layer 50, and is emitted after being guided by the second optical guiding layer 50; the second polarized light G(s) in the green light G(p,s) passes through the second polarization splitting layer 40 and enters the second phase conversion layer 60, is converted into the first polarized light G(p) by the second phase conversion layer 60, and then enters the first optical guiding layer 30, and is emitted after passing through the first optical guiding layer 30.

[0087] The processing of the blue light B(p, s) and the green light G(p, s) optical paths is similar. The first polarized light B(p) in the blue light B(p, s) is reflected by the second polarization splitting layer 80 to the second optical guiding layer 90, and is emitted after being guided by the second optical guiding layer 90; the second polarized light B(s) in the blue light B(p, s) passes through the second polarization splitting layer 80 and enters the second phase conversion layer 70, is converted into the first polarized light B(p) by the second phase conversion layer 70, and then enters the second optical guiding layer 50, and is emitted after passing through the second optical guiding layer 50.

[0088] Optionally, a light combining element is respectively provided for the first light and at least one second light emitted from the polarization conversion element, and the first light emitted from the polarization conversion element is combined into a beam of light and then emitted, and various second lights in the at least one second light emitted from the polarization conversion element are respectively combined into a beam of light and then emitted. Figure 5 In the polarization conversion element shown, a corresponding light combining element can be set to combine the red light, blue light and green light emitted from the polarization conversion element into one beam of light and then emit them. That is, after passing through the light combining element, the red light is one beam of light, the green light is one beam of light, and the blue light is one beam of light, which can be more evenly emitted into the subsequent spatial light modulation component, thereby making the final projection picture more uniform.

[0089] In some embodiments, at least one light guiding layer includes a first light guiding layer, a second light guiding layer and a phase conversion layer. The first light is incident on the first light guiding layer from the first side of the polarization conversion element. The first polarized light in the first light is reflected by the first light guiding layer and then emitted from the polarization conversion element. The second polarized light in the first light is incident on the phase conversion layer after passing through the first light guiding layer, and after being converted into the first polarized light by the phase conversion layer, it is incident on the second light guiding layer, and then emitted after being guided by the second light guiding layer. At least one supplementary light is incident on the first light guiding layer from the second side of the polarization conversion element, and then emitted through the first light guiding layer, the phase conversion layer and the second light guiding layer. The first side and the second side are not limited. For example, the first side can be the side of the polarization conversion element that is perpendicular to the light emitting side, and the second side can be the side of the polarization conversion element that is opposite to the light emitting side.

[0090] For example, Figure 6 FIG. 1 is a schematic diagram of the structure of a polarization conversion element provided in this embodiment. Figure 6 As shown, a target conversion area of ​​the polarization conversion element includes a first light guiding layer 10, a phase conversion element 20, and a second light guiding layer 30; assuming that the first light is red light R(p, s), at least one second light includes a supplementary light, which is yellow light Y(p, s); the first light guiding layer 10 includes a polarization splitter layer and a dichroic sublayer, the polarization splitter layer can transmit red S light and reflect red P light, and the dichroic sublayer can reflect yellow light Y(p, s) and transmit red S light.

[0091] The red light R(p, s) is incident on the first optical guide layer 10 from the first side of the polarization conversion element, and the first polarized light R(p) in the red light R(p, s) is reflected by the polarization splitter layer in the first optical guide layer 10 and then emitted from the polarization conversion element; the second polarized light R(s) in the red light R(p, s) is incident on the phase conversion layer 20 after passing through the polarization splitter layer and the dichroic sublayer of the first optical guide layer, and then is converted into the first polarized light R(p) by the phase conversion layer 20, and then is incident on the second optical guide layer 30, and then is emitted after being reflected by the second optical guide layer 30; the yellow light Y(p, s) is incident on the first optical guide layer 10 from the second side of the polarization conversion element, and then is reflected by the dichroic sublayer of the first optical guide layer 10 and then emitted through the phase conversion layer 20 and the second optical guide layer 30.

[0092] like Figure 6 The phase conversion layer 30 in the polarization conversion element shown can also be located at the light output port; that is, the second polarized light R(s) can be reflected from the second light guiding layer 30 to the phase conversion layer 20, and then converted into the first polarized light R(p) by the phase conversion layer 20 and then output; the yellow light Y(p,s) can be reflected from the second light guiding layer 30 and then output after passing through the phase conversion layer 20.

[0093] In some embodiments, at least one light guiding layer includes a first light guiding layer, a second light guiding layer and a phase conversion layer. The first light is incident on the first light guiding layer from the second side of the polarization conversion element, and the first polarized light in the first light is transmitted through the first light guiding layer and then emitted from the polarization conversion element; the second polarized light in the first light is reflected by the first light guiding layer and then incident on the phase conversion layer, and after being converted into the first polarized light by the phase conversion layer, it is incident on the second light guiding layer, and then emitted after being guided by the second light guiding layer; at least one supplementary light is incident on the first light guiding layer from the first side of the polarization conversion element, and then emitted after being reflected by the first light guiding layer.

[0094] For example, Figure 7 FIG. 1 is a schematic diagram of the structure of a polarization conversion element provided in this embodiment. Figure 7 As shown, a target conversion area of ​​the polarization conversion element includes a first light guiding layer 10, a phase conversion element 20, and a second light guiding layer 30; assuming that the first light is red light R (p, s), at least one second light includes a supplementary light, which is yellow light Y (p, s); the first light guiding layer 10 includes a dichroic sublayer and a polarization splitter sublayer, the polarization splitter sublayer can reflect red S light and transmit red P light, and the dichroic sublayer can reflect yellow light Y (p, s) and transmit red P light.

[0095] The red light R(p, s) is incident on the first optical guide layer 10 from the second side of the polarization conversion element, and the first polarized light red light R(p) in the red light R(p, s) is emitted from the polarization conversion element after passing through the polarization photonic layer and the dichroic sublayer of the first optical guide layer 10; the second polarized light red light R(s) in the red light R(p, s) is reflected by the polarization photonic layer of the first optical guide layer and then incident on the phase conversion layer 20, and after being converted into the first polarized light by the phase conversion layer 20, it is incident on the second optical guide layer 30, and is emitted after being guided by the second optical guide layer 30; the yellow light Y(p, s) is incident on the first optical guide layer 10 from the first side of the polarization conversion element, and is emitted after being reflected by the dichroic sublayer of the first optical guide layer 10.

[0096] In some embodiments, at least one light guiding layer includes a first light guiding layer, a second light guiding layer, a phase conversion layer and a third guiding layer. The first light is incident on the third light guiding layer from the second side of the polarization conversion element, and the first polarized light in the first light is reflected by the third light guiding layer to the second light guiding layer, and is emitted after being guided by the second light guiding layer; the second polarized light in the target light is incident on the phase conversion layer after passing through the third guiding layer, and is converted into the first polarized light by the phase conversion layer and is emitted after passing through the first light guiding layer; at least one supplementary light is incident on the first light guiding layer from the first side of the polarization conversion element, and is emitted after being reflected by the first light guiding layer.

[0097] For example, Figure 8 FIG. 1 is a schematic diagram of the structure of a polarization conversion element provided in this embodiment. Figure 8 As shown, a target conversion area of ​​the polarization conversion element includes a first light guide layer 10, a second light guide layer 40, a phase conversion layer 20 and a third guide layer 30. Assuming that the first light is red light R (p, s), at least one second light includes a supplementary light, which is yellow light Y (p, s); the first light guide layer 10 is a dichroic layer that can reflect yellow light and transmit red light; the third light guide layer 30 is a polarization splitting layer that can transmit S light and reflect P light.

[0098] The red light R(p, s) is incident on the third light guiding layer 30 from the second side of the polarization conversion element, and the first polarized light red light R(p) in the red light R(p, s) is reflected by the third light guiding layer to the second light guiding layer 40, and is emitted after being reflected by the second light guiding layer 40; the second polarized light red light R(s) in the red light R(p, s) is incident on the phase conversion layer 20 after passing through the third guiding layer 30, and is converted into the first polarized light red light R(p) by the phase conversion layer 20, and is emitted after passing through the first light guiding layer 10; the yellow light Y(p, s) is incident on the first light guiding layer 10 from the first side of the polarization conversion element, and is emitted after being reflected by the first light guiding layer 10.

[0099] In some embodiments, the conversion zones in the polarization conversion element are not completely the same. Optionally, when the polarization conversion element includes two or more conversion zones, the second light guide layer can be used to reflect the target second light and transmit the first light; for example, Figure 1 In the polarization conversion element shown, the second light guide layer 40 can be used to transmit red light and reflect yellow light; for example, Figure 5 The second light guiding layer 90 shown can be used to reflect blue light and transmit red light. Optionally, the conversion zone at the edge of the polarization conversion element can be different from the conversion zone in the middle part; for example, when the polarization conversion element includes two or more conversion zones, the conversion zone at the edge of the polarization conversion element only includes the polarization splitting layer, the first light guiding layer and the first phase conversion layer, for example, Figure 1 As shown in FIG. 1 , assuming that only two beams of red light and one beam of yellow light are incident on the polarization conversion element, the conversion zone at the edge only includes the polarization splitting layer, the first light guiding layer and the first phase conversion layer; if the polarization conversion element includes two or more conversion zones, the conversion zone in the middle only includes the area for processing the first light, such as Figure 7 As shown, except for the conversion zone at the edge that processes yellow light, the conversion zone in the middle can only process red light.

[0100] Optionally, when the polarization conversion element includes an even number of conversion regions, each conversion region is symmetrical with respect to the central axis of the polarization conversion element; for example, Figure 7 As shown, the polarization conversion element provided is that each conversion area is symmetrical with respect to the central axis of the polarization conversion element.

[0101] In this embodiment, by setting light guiding layers and phase conversion layers with different characteristics in each area of ​​the polarization conversion element, all regional spaces of the polarization conversion element are fully utilized to improve the utilization rate of light, thereby improving the brightness of the projection device; and supplementary light can be injected into certain areas to make the color gamut better; therefore, the polarization conversion element provided in this embodiment can improve the brightness and color gamut of the projection device.

[0102] This embodiment also provides a light combining system. Fig. 9 A schematic diagram of the structure of a light combining system provided in this embodiment is as follows: Fig. 9 As shown, the light combining system includes a light source device 101, a collimating element 102, a polarization conversion element 103 described in any of the above embodiments, a light homogenizing element 105 and a spatial light modulation component 106. The light source device 101 is used to generate a first light and at least one second light.

[0103] Optionally, the light source device includes at least one light-emitting unit, a substrate and a reflective dam, and the reflective dam is arranged on the side of at least one light-emitting unit. Optionally, the light source device includes a light-emitting unit array including a plurality of light-emitting units, and the reflective dam is arranged on the periphery of the light-emitting unit array. The light-emitting unit is not limited, for example, it can be an LED chip; the reflective dam can reflect the large-angle part and / or part of the edge light of the light beam for utilization. Optionally, the reflective dam can be a thermally conductive material to further improve the heat dissipation efficiency of the light source device.

[0104] Optionally, when the first light includes the first color light, and at least one second light includes the second color light and the third color light, the light source device includes at least one first light-emitting unit that generates the first color light, at least one second light-emitting unit that generates the second color light, and at least one third light-emitting unit that generates the third color light, and at least one first light-emitting unit, at least one second light-emitting unit, and at least one third light-emitting unit can be arranged alternately; thereby, the light incident on the spatial light modulation component can be made more uniform. There is no limitation on the first color light, the second color light, and the third color light, for example, they can be red light, green light, and blue light, respectively. Then, the light combining system correspondingly adopts a polarization conversion element without supplementary light described in any of the above embodiments, and a spatial light modulation component.

[0105] Optionally, the collimating element 102 may be a collimating lens array; for example, the collimating element 102 includes a plurality of collimating lenses corresponding to each light emitting unit in the light source device 101 , and is used to collimate and collect the light generated by the light emitting unit.

[0106] Optionally, the spatial light modulation component 106 is not limited, for example, it can include a liquid crystal modulation element, a polarizer and a half-wave plate, and the liquid crystal modulation element can be a transmissive liquid crystal panel. The light homogenization element 105 can include any one or more of a diffuser, a diffuser wheel, a reflector, a light rod, and a compound eye.

[0107] Optionally, the light combining system may further include a light combining component and a projection lens.

[0108] In some embodiments, if the first light includes a first color light, a second color light, and a third color light, and the spatial light modulation component includes a first liquid crystal modulation element corresponding to the first color light, a second liquid crystal modulation element corresponding to the second color light, and a third liquid crystal modulation element corresponding to the third color light; then the light combining system includes at least one of a polarization conversion element corresponding to the first liquid crystal modulation element, a polarization conversion element corresponding to the second liquid crystal modulation element, and a polarization conversion element corresponding to the third liquid crystal modulation element.

[0109] There is no limitation on the first color light, the second color light and the third color light; for example, they can be red light, green light and blue light respectively. When the first color light is red light and the second color light is green light, the second light can be supplementary light, the supplementary light is yellow light, and the red light and the green light correspond to a liquid crystal modulation element and any one of the polarization conversion elements with supplementary light described in the above embodiments respectively; when the third color light is blue light, the second light can be supplementary light, the supplementary light is cyan light, and any one of the polarization conversion elements with supplementary light described in the above embodiments is used; or there can be no supplementary light, and any one of the polarization conversion elements without supplementary light described in the above embodiments can be used. For example, Fig.10 , which is a schematic diagram of the structure of a light combining system, including a component 100 corresponding to a first color light (a first liquid crystal modulation element and a corresponding polarization conversion element, etc.), a component 200 corresponding to a second color light (a second liquid crystal modulation element and a corresponding polarization conversion element, etc.), a component 300 corresponding to a third color light (a third liquid crystal modulation element and a corresponding polarization conversion element, etc.), a light combining component 400 and a projection lens 500; the light combining component 400 can be used to guide the light beams emitted by the components corresponding to each color light to the projection lens. The specific structural diagrams of the components 100-300 can be referred to Fig. 9 shown.

[0110] In this embodiment, the polarization conversion element and the light source device in the light combining system are designed to cooperate with each other to improve the utilization rate of light; and the light source device also improves the utilization rate of light by reflecting the large-angle part and / or part of the edge light of the light beam through a reflective dam; therefore, the brightness and color gamut of the projection device can be improved.

[0111] Fig.11 This is a schematic diagram of the functional modules of a projection device provided in this application. Fig.11 As shown, the projection device includes an image processor 201 and a projection optical engine 202. Among them:

[0112] The image processor 201 may be a microcontroller, a dedicated image processing chip, etc. The microcontroller may be an ARM chip, a microcontroller unit (MCU), etc. The dedicated image processing chip may be an image signal processor (ISP), a graphics processing unit (GPU), an embedded neural network processor (NPU), etc. The image processor 201 may be used for video decoding, image quality processing, etc.

[0113] The projection optical machine 202 may include a driver chip and the light combining system described in the above embodiment. The spatial light modulation component in the light combining system may be a digital micromirror device (DMD), a liquid crystal display (LCD), a liquid crystal on silicon (LCOS), etc. The driver chip corresponds to the spatial light modulation component, for example, the digital micromirror device may be driven by a digital light processing element (DLP). The projection optical machine 202 is used to project the image to be projected into a projection screen.

[0114] In some embodiments, the projection device further includes a central controller 203 with one or more processing cores, which may be a CPU, ARM, MCU or other controller. The central controller 203 is the control center of the projection device, and uses various interfaces and lines to connect various parts of the entire projection device, and can run or execute software programs and / or operating systems stored in the memory 204, and call data stored in the memory 204. Optionally, the image processor 202 and the central controller 203 may be integrated into one processor.

[0115] In some embodiments, the projection device further includes a memory 204 of one or more computer-readable storage media, an input module 205, a communication module 206, a power supply 207 and other components. Those skilled in the art will appreciate that Figure 2 The structure of the projection device shown in the figure does not constitute a limitation on the projection device, and may include more or fewer components than shown in the figure, or combine certain components, or arrange the components differently.

[0116] The memory 204 can be used to store software programs and operating systems. The central controller 203 executes various functional applications and data processing by running the software programs and operating systems stored in the memory 204. The memory 204 can mainly include a program storage area and a data storage area, wherein the program storage area can store an operating system, an application required for at least one function (such as a sound playback function, an image playback function, etc.), etc.; the data storage area can store data created according to the use of the projection device, etc. In addition, the memory 204 can include a high-speed random access memory, and can also include a non-volatile memory, such as at least one disk storage device, a flash memory device, or other volatile solid-state storage devices. Accordingly, the memory 204 can also include a memory controller to provide the central controller 203 with access to the memory 204.

[0117] The projection device may further include an input module 205, which may be used to receive input digital or character information and generate remote control, keyboard, mouse, joystick, optical or trackball signal input related to user settings and function control.

[0118] The projection device may further include a communication module 206. In some embodiments, the communication module 206 may include a wireless module. The projection device may perform short-distance wireless transmission through the wireless module of the communication module 206, thereby providing the user with wireless broadband Internet access. For example, the communication module 206 may be used to help the user access streaming media, etc.

[0119] The projection device also includes a power supply 207 for supplying power to various components. In some embodiments, the power supply 207 can be logically connected to the central controller 203 through a power management system, so as to manage charging, discharging, and power consumption through the power management system. The power supply 207 can also include any components such as one or more DC or AC power supplies, recharging systems, power failure detection circuits, power converters or inverters, and power status indicators.

[0120] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the present application. The singular forms of "a", "said" and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings. It should also be understood that the term "and / or" used in this article refers to and includes any or all possible combinations of one or more associated listed items. The character " / " herein generally indicates that the objects associated before and after are a kind of "or" relationship.

[0121] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A polarization conversion element, characterized in that: The polarization conversion element includes at least one conversion zone, the target conversion zone includes at least one light guide layer and at least one phase conversion layer, and the target conversion zone is any one of the at least one conversion zone; A first polarized light in the first light incident on the target conversion area is guided by the at least one light guide layer and then emitted from the polarization conversion element, and a second polarized light in the first light is converted by the at least one phase conversion layer into the first polarized light through the at least one light guide layer and the at least one phase conversion layer and then emitted; At least one type of second light incident on the target conversion zone is guided by the at least one light guiding layer and then emitted from the polarization conversion element; or, a first polarized light among the at least one type of second light incident on the target conversion zone is guided by the at least one light guiding layer and then emitted from the polarization conversion element, and the second polarized light among the at least one type of second light passes through the at least one light guiding layer and the at least one phase conversion layer, is converted into the first polarized light by the at least one phase conversion layer and then emitted.

2. The polarization conversion element according to claim 1, characterized in that: The at least one optical guiding layer includes a first polarization splitting layer and a first optical guiding layer, and the at least one phase conversion layer includes a first phase conversion layer; The target light is incident on the first polarization splitting layer; The first polarized light in the target light is transmitted through the first polarization splitting layer and then emitted; the second polarized light in the target light is reflected by the first polarization splitting layer to the first light guiding layer, guided to the first phase conversion layer by the first light guiding layer, converted to the first polarized light by the first phase conversion layer and then emitted; Alternatively, the first polarized light in the target light is reflected by the first polarization splitting layer to the first light guiding layer, and is emitted after being guided by the first light guiding layer; the second polarized light in the target light is incident on the first phase conversion layer after passing through the first polarization splitting layer, and is emitted after being converted into the first polarized light by the first phase conversion layer; Alternatively, the first polarized light in the target light is emitted after passing through the first polarization splitting layer, and the second polarized light in the target light is reflected to the first phase conversion layer, converted into the first polarized light by the first phase conversion layer, and then incident on the first light guiding layer, and then emitted after being guided by the first light guiding layer; The target light is the first light, or the first light and the at least one second light, or the first light and the target second light, and the target second light is any one of the at least one second light.

3. The polarization conversion element according to claim 2, characterized in that: When only the first light is incident on the first polarization splitting layer, the first light guiding layer is a reflective layer or a dichroic layer, and the at least one light guiding layer further includes a second light guiding layer; The target second light is incident on the reflective layer or the dichroic layer, reflected by the reflective layer or the dichroic layer to the second light guiding layer, and then emitted after being guided by the second light guiding layer.

4. The polarization conversion element according to claim 2, characterized in that: When only the first light is incident on the first polarization splitting layer, the first light guiding layer includes a polarization splitting sublayer and a dichroic sublayer, and the dichroic sublayer reflects the first light and transmits the target second light; the at least one light guiding layer also includes a second light guiding layer, and the at least one phase conversion layer includes a second phase conversion layer; The target second light is incident on the first light guiding layer, the first polarized light in the target second light is transmitted through the polarization photonic layer and the dichroic layer and is emitted from the polarization conversion element, the second polarized light in the target second light is reflected by the polarization photonic layer to the second phase conversion layer, is converted into the first polarized light by the second phase conversion layer, and is incident on the second light guiding layer, and is emitted after being guided by the second light guiding layer.

5. The polarization conversion element according to claim 2, characterized in that: When only the first light is incident on the first polarization splitting layer, the first light guiding layer reflects the first light and transmits the target second light, and the at least one light guiding layer includes a second polarization splitting layer, a second light guiding layer, and a second phase conversion layer; The first polarized light in the target second light is reflected by the second polarization splitting layer to the second light guiding layer, and is emitted after being guided by the second light guiding layer; the second polarized light in the target second light passes through the polarization splitting layer and enters the second phase conversion layer, is converted into the first polarized light by the second phase conversion layer, and enters the first light guiding layer, and is emitted after passing through the first light guiding layer.

6. The polarization conversion element according to claim 4 or 5, characterized in that: A light combining element is respectively provided corresponding to the first light and at least one second light emitted from the polarization conversion element, and the first light emitted from the polarization conversion element is combined into a beam of light and then emitted, and various second lights in the at least one second light emitted from the polarization conversion element are respectively combined into a beam of light and then emitted.

7. The polarization conversion element according to any one of claims 2 to 5, characterized in that: When the polarization conversion element includes two or more conversion regions, the second light guiding layer is used to reflect the target second light and transmit the first light.

8. The polarization conversion element according to claim 1, characterized in that: The second light is supplementary light for the first light, and a wavelength band of the first light and a wavelength band of the supplementary light include a wavelength band belonging to the target primary color light.

9. The polarization conversion element according to claim 8, characterized in that: The at least one optical guiding layer comprises a first optical guiding layer, a second optical guiding layer and a phase conversion layer; The first light is incident on the first light guiding layer from the first side of the polarization conversion element, and the first polarized light in the first light is reflected by the first light guiding layer and then emitted from the polarization conversion element; the second polarized light in the first light is incident on the phase conversion layer after passing through the first light guiding layer, and after being converted into the first polarized light by the phase conversion layer, it is incident on the second light guiding layer, and then emitted after being guided by the second light guiding layer; the at least one supplementary light is incident on the first light guiding layer from the second side of the polarization conversion element, and is emitted through the first light guiding layer, the phase conversion layer and the second light guiding layer; Alternatively, the first light is incident on the first light guiding layer from the second side of the polarization conversion element, and the first polarized light in the first light is transmitted through the first light guiding layer and then emitted from the polarization conversion element; the second polarized light in the first light is reflected by the first light guiding layer and then incident on the phase conversion layer, and after being converted into the first polarized light by the phase conversion layer, it is incident on the second light guiding layer, and then emitted after being guided by the second light guiding layer; the at least one supplementary light is incident on the first light guiding layer from the first side of the polarization conversion element, and then emitted after being reflected by the first light guiding layer; Alternatively, the at least one light guiding layer also includes a third guiding layer, the first light is incident on the third light guiding layer from the second side of the polarization conversion element, the first polarized light in the first light is reflected by the third light guiding layer to the second light guiding layer, and is emitted after being guided by the second light guiding layer; the second polarized light in the target light is incident on the phase conversion layer after passing through the third guiding layer, and is converted into the first polarized light by the phase conversion layer and is emitted after passing through the first light guiding layer; the at least one supplementary light is incident on the first light guiding layer from the first side of the polarization conversion element, and is emitted after being reflected by the first light guiding layer.

10. The polarization conversion element according to claim 1, characterized in that: When the polarization conversion element includes an even number of conversion regions, each conversion region is symmetrical with respect to the central axis of the polarization conversion element.

11. The polarization conversion element according to claim 1, characterized in that: A quadrangular prism and / or a triangular prism is disposed between the at least one light guiding layer and the at least one phase conversion layer, between the at least one light guiding layer, and between the at least one phase conversion layer; Alternatively, the at least one light guiding layer and the at least one phase conversion layer are fixed by a fixing member.

12. A light combining system, characterized in that: The light combining system includes a light source device, a collimating element, the polarization conversion element described in any one of claims 1 to 10, a light homogenizing element and a spatial light modulation component, and the light source device is used to generate the first light and the at least one second light.

13. The light combining system according to claim 12, characterized in that: If the first light includes a first color light, a second color light and a third color light, the spatial light modulation component includes a first liquid crystal modulation element corresponding to the first color light, a second liquid crystal modulation element corresponding to the second color light and a third liquid crystal modulation element corresponding to the third color light; The light combining system includes at least one of a polarization conversion element corresponding to the first liquid crystal modulation element, a polarization conversion element corresponding to the second liquid crystal modulation element, and a polarization conversion element corresponding to the third liquid crystal modulation element.

14. The light combining system according to claim 12, characterized in that: The light source device comprises at least one light emitting unit, a substrate and a reflective dam, wherein the reflective dam is arranged on a side surface of the at least one light emitting unit.

15. The light combining system according to claim 14, characterized in that: The light source device includes a light emitting unit array including a plurality of light emitting units, and the reflective dam is arranged around the periphery of the light emitting unit array.

16. A projection device, characterized in that: A light combining system comprising any one of claims 12-15.

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