Polarized light source device

Abstract

The polarization light source device includes a transparent wavelength conversion sheet (10, 101, 201, 301, 401), a collimator lens group (20, 103, 203, 303, 403), a quarter-wave plate (30, 104, 204, 304, 404), and a reflective polarization beam splitter (40, 105, 205, 305, 405) along an optical path. The transparent wavelength conversion sheet (10, 101, 201, 301, 401) emits excited light (12, 113, 213, 313, 413) after receiving the excitation light (11A, 11B, 112, 212, 312, 412). The slow axis of the quarter-wave plate (30, 104, 204, 304, 404) and the transmission axis of the reflective polarization beam splitter (40, 105, 205, 305, 405) are at an angle of about 45 DEG. The excitation light (11A, 11B, 112, 212, 312, 412) can be irradiated onto the transparent wavelength conversion sheet (10, 101, 201, 301, 401) from the side close to or away from the collimator lens group (20, 103, 203, 303, 403). The device further comprises a reflective film layer (50, 101a, 201a) and a dichroic mirror (107, 207) in the close-in case, or comprises a dichroic film layer (311a, 411a) in the away-from case. The transparent wavelength conversion sheet (10, 101, 201, 301, 401) optionally comprises at least two portions (201M, 201N) which are adjustably movable to be alternately arranged in the optical path such that the device is able to alternately produce different output light.

Description

Technical Field

[0001] The present disclosure generally relates to the field of projection display technology, and more particularly to polarized light sources and projection systems. Background Art

[0002] The three main existing types of projection display systems include liquid crystal display (LCD) projection display systems, liquid crystal on silicon (LCOS) projection display systems, and digital light processing (DLP) projection display systems. Both LCD and LCOS projection display systems achieve image formation by modulating the polarization state of the light beam emitted from a light source, thereby requiring the light beam incident on their display chips to be linearly polarized light.

[0003] Typical light sources for projection display systems can include ultra-high performance (UHP) lamps, xenon lamps, light-emitting diodes (LEDs), laser-excited fluorescence light sources, or laser diodes, etc.

[0004] Among them, the light emitted by UHP lamps, xenon lamps, LEDs, and laser-excited fluorescence light sources is all unpolarized light. Therefore, in order to apply these unpolarized light sources to LCD and / or LCOS projection display systems, it is necessary to convert the unpolarized light emitted from them into polarized light, otherwise only 50% of the light energy can be utilized. However, when converting the emitted light beam from unpolarized light to polarized light, the prior art usually expands the optical extent (i.e., the angular diffusion area) of the light beam to twice the original, resulting in an increase in the volume of the projection system, an increase in manufacturing costs, and energy loss during the conversion process.

[0005] Laser diodes are polarized light sources, and they have high energy utilization efficiency when applied to LCD and LCOS projection display systems, but currently the price of laser diode light sources is expensive.

[0006] Therefore, in LCD and LCOS projection display systems, there is an urgent need for a polarized light source with relatively high brightness and a suitable price, or a polarized light source with a polarization conversion method that does not increase optical expansion. Summary of the Invention

[0007] To solve the problems related to existing projection display systems, the present disclosure provides a polarized light source device.

[0008] The polarization light source device includes a transparent wavelength conversion sheet, a collimating lens group, a quarter-wave plate, and a reflective polarization beam splitter arranged in sequence along an optical path. The transparent wavelength conversion sheet is approximately arranged at the focal plane of the collimating lens group and is configured to emit excited light when receiving excitation light. The collimating lens group is configured to collimate the excited light to generate collimated excited light. The quarter-wave plate is configured such that the angle between its slow axis and the transmission axis of the reflective polarization beam splitter is approximately 45°. Herein, the angle between the direction of the excitation light and the optical path can be less than approximately 35°, preferably less than approximately 10°, more preferably less than approximately 5°, and most preferably approximately 0°. The term "optical path" as used herein refers to the path that the excited light travels in the polarization light source device after being generated in the transparent wavelength conversion sheet, and this path extends substantially along the axis parallel to the transmission path of the collimated excited light.

[0009] According to the direction of the excitation light irradiating on the transparent wavelength conversion sheet, for the polarization light source device according to different embodiments of the present disclosure, there can be two different situations.

[0010] In the first case for the polarization light source device, the excitation light irradiates on the transparent wavelength conversion sheet from the side of the transparent wavelength conversion sheet close to the collimating lens group. Correspondingly, the polarization light source device is further provided with a reflective film layer on the side of the transparent wavelength conversion sheet away from the collimating lens group, and the reflective film layer has a reflective surface facing the transparent wavelength conversion sheet. Herein, the reflective film layer is configured to reflect at least a part of the excited light from the transparent wavelength conversion sheet back to the collimating lens group.

[0011] To facilitate the dissipation of the heat generated in the transparent wavelength conversion sheet during the operation of the polarization light source device, the polarization light source device is optionally further provided with a heat dissipation substrate on the side of the reflective film layer away from the transparent wavelength conversion sheet.

[0012] Optionally herein, the reflective film layer can be coated on the surface of the transparent wavelength conversion sheet close to the heat dissipation substrate, and the heat dissipation substrate is further configured to be attached to the transparent wavelength conversion sheet coated with the reflective film layer for heat dissipation.

[0013] Alternatively, the reflective film layer can be coated on the surface of the heat dissipation substrate close to the transparent wavelength conversion sheet. The reflective film layer has a reflective surface facing the transparent wavelength conversion sheet, and the heat dissipation substrate coated with the reflective film layer is also configured to be attached to the transparent wavelength conversion sheet for heat dissipation. Optionally herein, the reflective film layer can be integrated with the heat dissipation substrate to form a single entity. In other words, the heat dissipation substrate is configured to be directly attached to the transparent wavelength conversion sheet for heat dissipation, and the surface of the heat dissipation substrate facing the transparent wavelength conversion sheet is configured to be reflective.

[0014] In the first case, further, the excitation light source may be the first incident light that passes through the collimating lens group from the side of the collimating lens group away from the transparent wavelength conversion sheet and transmits toward the transparent wavelength conversion sheet. Therefore, in order to separate the input light and the output light, the polarization light source device further includes a dichroic mirror arranged on the side of the collimating lens group away from the transparent wavelength conversion sheet, and the dichroic mirror is designed to have two different configurations. In the first configuration, the dichroic mirror is configured to allow the first input light entering the polarization light source device to be reflected on the dichroic mirror, thereby providing the first incident light, and is also configured to allow the laser light or any derivative thereof (i.e., the light originating from the laser light passing through any of the following optical components (including the collimating lens group, the quarter-wave plate, or the reflective polarization beam splitter)) to transmit through the dichroic mirror and thus become the first output light emitted from the polarization light source device. In the second configuration, the dichroic mirror is configured to allow the second input light entering the polarization light source device to transmit through the dichroic mirror, thereby providing the first incident light, and is also configured to allow the laser light or any derivative thereof (i.e., the light originating from the laser light passing through any of the following optical components (including the collimating lens group, the quarter-wave plate, or the reflective polarization beam splitter)) to be reflected thereon and thus become the second output light emitted from the polarization light source device.

[0015] Regardless of the configuration herein, the dichroic mirror can be arranged at any one of the following three positions in the optical path: (1) between the collimating lens group and the quarter-wave plate; (2) between the quarter-wave plate and the reflective polarization beam splitter; or (3) on the side of the reflective polarization beam splitter away from the quarter-wave plate. Optionally, the dichroic mirror can also be arranged at an angle of about 30 - 60° with the optical path, and optionally about 45°.

[0016] In a first scenario, the polarization light source device further includes a first housing that houses the above optical components, including the transparent wavelength conversion sheet, the collimating lens group, the quarter-wave plate, the reflective polarization beam splitter, and the dichroic mirror. The first housing is provided with an entrance and an exit. The entrance allows input light to enter the polarization light source device through the entrance, and the exit allows output light to be emitted from the polarization light source device through the exit. In an embodiment where the dichroic mirror has a first configuration, the entrance allows the first input light to enter the polarization light source device through the entrance, and the first input light is then reflected on the dichroic mirror to provide the first incident light; and the exit allows the first output light to be emitted from the polarization light source device through the exit. In an embodiment where the dichroic mirror has a second configuration, the entrance allows the second input light to enter through the entrance to provide the first incident light; and the exit allows the second output light to be emitted from the polarization light source device through the exit. Herein, the first housing can optionally provide a reflective inner surface.

[0017] In any of the above embodiments of the polarization light source device, the first incident light optionally includes linearly polarized light having a polarization direction substantially parallel to the transmission axis of the reflective polarization beam splitter, and further optionally, the linearly polarized light is substantially collimated. Thus, the first incident light can be the input light provided by a laser diode light source.

[0018] In a second scenario for the polarization light source device, the excitation light can be incident on the transparent wavelength conversion sheet from a side of the transparent wavelength conversion sheet away from the collimating lens group. Herein, according to some embodiments, the excitation light may be sourced from a second incident light that is transmitted from a side of the transparent wavelength conversion sheet away from the collimating lens group toward the reflective polarization beam splitter. The polarization light source device can further include a dichroic film layer disposed on a side of the transparent wavelength conversion sheet away from the collimating lens group, wherein the dichroic film layer is configured to allow the second incident light to be transmitted through the dichroic film layer to provide the excitation light, and to reflect at least a portion of the laser light from the transparent wavelength conversion sheet back to the reflective polarization beam splitter along an optical path.

[0019] Herein, optionally, the polarization light source device can further include a transparent substrate on a side of the dichroic film layer away from the transparent wavelength conversion sheet, which is configured to allow the second incident light to be transmitted through the transparent substrate.

[0020] Similar to the embodiment of the polarization light source device described in the first case above, in the second case, the polarization light source device may further include a second housing. The transparent wavelength conversion sheet, the collimating lens group, the quarter-wave plate, and the reflective polarization beam splitter are arranged in the second housing. The second housing is also provided with an entrance that allows the second incident light to enter the polarization light source device through the entrance. Optionally, the second housing can be configured to have a reflective inner surface.

[0021] In the embodiment of the polarization light source device described in the second case above, the second incident light can include unpolarized light, and the second incident light can be provided by a light-emitting diode (LED) light source. Optionally, according to a specific embodiment, the second incident light can include polarized light.

[0022] In the polarization light source device in any of the above embodiments, the transparent wavelength conversion sheet can optionally be configured to be static, but can also optionally be configured to move adjustably in a plane perpendicular to the optical path.

[0023] In this document, according to some embodiments, the transparent wavelength conversion sheet can include at least two parts, each part including a different material, and the material can be selected from one of a reflective material, a transparent material, or a transparent wavelength conversion material. Therefore, the transparent wavelength conversion sheet is configured to move adjustably such that the at least two parts of the transparent wavelength conversion sheet are alternately arranged in the optical path, so that the polarization light source device alternately generates different output lights.

[0024] Optionally in this document, the at least two parts of the transparent wavelength conversion sheet can be arranged in different sector regions of a circle or different segments of a ring, and the transparent wavelength conversion sheet is configured to rotate adjustably around an axis, and the rotation axis of the axis is substantially located at the center of the circle or the center of the ring. The transparent wavelength conversion sheet can be configured to rotate at a speed of at least 2400 revolutions per minute (such as 2400 revolutions per minute, 3600 revolutions per minute, 7200 revolutions per minute, 14400 revolutions per minute, etc.).

[0025] In this document, when a specific portion of the transparent wavelength conversion sheet including a specific transparent wavelength conversion material is disposed in the optical path, corresponding stimulated light is excited, and specific output light is generated by the polarization light source device. When another portion of the transparent wavelength conversion sheet including a different transparent wavelength conversion material is disposed in the optical path, different stimulated light is excited, and different output light is generated by the polarization light source device. When yet another portion of the transparent wavelength conversion sheet, which includes a reflective material for the polarization light source device (such as a ceramic reflective material having a rough surface capable of scattering incident light) in the first case above or a transparent material for the polarization light source device in the second case above, is disposed in the optical path, the output light generated thereby by the polarization light source device is substantially the excitation light.

[0026] In this document, according to some embodiments, the transparent wavelength conversion sheet can include three portions configured such that the polarization light source device alternately generates three different output lights having three different primary colors, such as RGB colors, which include red (R), green (G), and blue (B). There can be different situations.

[0027] In the first situation, the three portions may respectively include three different transparent wavelength conversion materials configured to respectively excite three lights having three different primary colors when receiving the excitation light.

[0028] In the second situation, two of the three portions can respectively include two different transparent wavelength conversion materials configured to respectively stimulate two kinds of stimulated light having two different colors when receiving the excitation light; and the last portion of the third portion includes a transparent material that allows the excitation light to transmit therethrough or a reflective material that allows the excitation light to be reflected back therefrom.

[0029] In this second situation, optionally, the excitation light is blue light, and the two kinds of stimulated light are composed of green light and red light. For example, referring to Table 1 below, the excitation light can be blue light with a wavelength of 455 nm, and the two different transparent wavelength conversion materials respectively include: a first green light excitation component selected from LuAG:Ce 3+ or MgAlON∶Mn, and a second red light excitation component selected from YAG:Mn / Mg, CaAlSiN3:Eu 2+ 、Sr2Si5N8:Eu 2+ or CaAlSiN3:Eu 2+A second red light-exciting component selected therefrom. In a specific embodiment, the excitation light input into the device is blue light with a wavelength of 455 nm, and the transparent wavelength conversion sheet includes a first part, which includes a ceramic reflective material or a transparent material that allows the device to output blue (B) light when arranged in the optical path. The second part of the transparent wavelength conversion sheet includes a transparent ceramic material containing Sr2Si5N8:Eu 2+ such that the transparent ceramic material can emit red light with a wavelength in the range of 590 - 620 mm when excited by the blue light. Thus, when the second part is arranged in the optical path, the polarized light source device emits red (R) light. The third part of the transparent wavelength conversion sheet can include a transparent ceramic material containing LuAG:Ce 3+ (Lu3Al5O 12 :Ce 3+ ) such that the transparent ceramic material can emit green light with a wavelength within 480 to 620 nm when excited by the blue light. Thus, when the third part is arranged in the optical path, the polarized light source device emits green (G) light.

[0030] Also in the second case above, the excitation light is blue light, the two laser-excited lights consist of yellow light and red light, and the polarized light source device is further provided with a color filter configured to generate green light from the yellow light. In a specific embodiment of the above-described polarized light source device by way of example, the third part of the transparent wavelength conversion sheet alternatively includes a transparent ceramic material containing YAG:Ce 3+ (Y3Al5O 12 :Ce 3+ ) which can emit yellow light with a wavelength of 510 to 630 nm when excited by the blue light (445 nm), and a color filter can be additionally arranged in the optical path of the polarized light source device to allow the device to filter the excited green light, thereby outputting green (G) light.

[0031] Therefore, by controllably adjusting the alternating arrangement of these three parts in the optical path of the polarized light source device, the output of full-color light can be achieved.

[0032] In any of the embodiments of the above-described polarized light source device, the collimating lens group can optionally include a single convex lens (i.e., a double-sided convex lens), two plano-convex lenses opposite to each other, or a plurality of convex lenses arranged in an array in a plane perpendicular to the optical path. Optionally, the divergence angle of the collimated laser-excited light emitted from the collimating lens group towards the reflective polarization beam splitter with respect to the optical path is less than about 20°. Description of the Drawings

[0033] Figure 1Shows the schematic structure of the polarization light source device provided in the present disclosure;

[0034] Figure 2 Shows the schematic structure of the polarization light source device according to the first embodiment of the present disclosure;

[0035] Figure 3A and Figure 3B respectively show the schematic structure of the polarization light source device according to the second embodiment of the present disclosure, and the annular transparent wavelength conversion sheet;

[0036] Figure 4 Shows the schematic structure of the polarization light source device according to the third embodiment of the present disclosure; and

[0037] Figure 5 Shows the schematic structure of the polarization light source device according to the fourth embodiment of the present disclosure. Detailed Description of the Invention

[0038] Hereinafter, with reference to the accompanying drawings of the present disclosure, the technical solutions provided in various embodiments of the disclosure are described in more detail. It should be noted that the embodiments listed in the present disclosure should be regarded as only a part of the embodiments covered by the present disclosure, rather than all of them, and therefore should not be regarded as imposing any limitation on the protection scope of the present disclosure. Based on the embodiments provided in the present invention, other embodiments with other minor design changes, as long as they do not deviate from the key points disclosed in the present invention and can be easily obtained by those of ordinary skill in the art without involving any creative work, should be regarded as belonging to the protection scope covered by the present disclosure.

[0039] To solve the above problems related to the prior art, the present disclosure provides a light source device. According to different embodiments, the light source device provided herein can effectively convert unpolarized light into polarized light (see, for example, Examples 3 and 4 below), or can effectively convert the first polarized light into the second polarized light (see, for example, Examples 1 and 2 below), thereby significantly improving the utilization rate of the light source used in the LCD projection display system and / or the LCOS projection display system.

[0040] Specifically, the polarization light source device provided in the present disclosure is configured to emit an output stimulated light that is linearly polarized once an input excitation light is received.

[0041] According to Figure 1As shown in the schematic diagram of the polarization light source device, the polarization light source device includes a transparent wavelength conversion sheet 10, a collimating lens group 20, a quarter-wave plate 30, and a reflective polarization beam splitter 40, which are arranged in sequence along the optical path of the polarization light source device, as shown by the arrows from bottom to top in the figure. Among them, the optical path is substantially along the optical axis (i.e., its axis of rotational symmetry) of the collimating lens group 20.

[0042] The transparent wavelength conversion sheet 10 includes a transparent wavelength conversion material. As used herein, the term "transparent wavelength conversion material" refers to a material that, when excited by an excitation light (i.e., a stimulating light, such as Figure 1 the excitation light beams 11A and / or 11B shown), can emit a laser light (i.e., a stimulated light, such as Figure 1 the laser light beam 12 shown), and is transparent to the laser light. Optionally herein, non-limiting examples of the components of the transparent wavelength conversion material that can be used as the transparent wavelength conversion sheet 10 include YAG:Ce 3+ (Y3Al5O 12 :Ce 3+ ), LuAG:Ce 3+ (Lu3Al5O 12 :Ce 3+ ), YAG:Mn / Mg, MgAlON∶Mn, CaAlSiN3:Eu 2+ , Sr2Si5N8:Eu 2+ and CaAlSiN3:Eu 2+ etc. (for more details, please refer to Table 1). Any one or any combination of the above components can optionally be processed into a transparent fluorescent ceramic, a fluorescent crystal, or a fluorescent glass, etc., which can also optionally be in the form of a sheet with a thickness less than 1 mm. Herein, the term "fluorescent ceramic" refers to a ceramic material obtained by sintering any one of the fluorescent components; the term "fluorescent crystal" refers to a single crystal material obtained by crystallization or other methods from any one of the fluorescent components; and the term "fluorescent glass" refers to a glass material obtained by sintering any one of the fluorescent components together with a transparent glass material.

[0043] To improve the utilization rate of the laser light of the polarization light source device, a reflective film layer 50 can be arranged on the surface of the transparent wavelength conversion sheet 10 opposite to the collimating lens group 20 (i.e., on Figure 1 the bottom surface 10A shown), and the reflective film layer is configured to reflect a part of the laser light 12 excited by the transparent wavelength conversion material in the transparent wavelength conversion sheet 10, and a part of the laser light 12 is directed towards the reflective surface of the reflective film layer 50 (i.e., Figure 1propagates on the bottom surface of the reflective film layer 50 and touches the reflective surface of the reflective film layer 50. As used herein, the term "reflective film layer" refers to a layer or film capable of reflecting light (such as, Figure 1 the irradiated laser light 12 shown).

[0044] According to some embodiments, the reflective film layer 50 can be configured such that it can only reflect and not transmit the irradiated laser light, such as the reflective film layer 101a in Example 1 and the reflective film layer 201a in Example 2 described below. Therefore, the reflective film layer 50 can be an ordinary reflective film layer (i.e., a film layer having a metal (e.g., copper, aluminum, silver, gold, etc.) component, an alloy (e.g., copper-aluminum alloy, etc.) component, or a component having other reflective materials (e.g., a multilayer dielectric high-reflection film)).

[0045] According to some other embodiments, the reflective film layer 50 can be specifically configured as a dichroic film layer, which can reflect the irradiated laser light but can also transmit the excitation light, such as the dichroic film layer 311a in Example 3 and the dichroic film layer 411a in Example 4 described below. According to some embodiments, the dichroic film layer is configured to transmit blue light and reflect green light. According to some other embodiments, the dichroic film layer is configured to transmit blue light and reflect yellow light. According to some other embodiments, the dichroic film layer is configured to transmit blue light and reflect red light. There may also be other embodiments. The materials, structures, and manufacturing methods for the dichroic film layer have been disclosed in patent documents WO2014158802A1, WO1999036814A1, WO1999036805A1, US8927070B2, US3190178A, and US5066098A, the disclosures of which are incorporated herein by reference in their entirety.

[0046] In this document, the reflective film layer 50 can optionally be coated on the surface of the transparent wavelength conversion sheet 10 opposite to the collimating lens group 20 (i.e., Figure 1 the bottom surface 10A shown), but can also optionally be coated on the top surface of the substrate arranged below the transparent wavelength conversion sheet 10 (the substrate is not Figure 1 shown in).

[0047] In this document, according to different embodiments of the polarized light source device, the excitation light can enter or be incident on the transparent wavelength conversion sheet 10 from different directions.

[0048] According to some embodiments described in more detail in Example 1 and Example 2, the excitation light 11A enters or is incident on the transparent wavelength conversion sheet 10 in a direction opposite to the optical path direction of the collimated stimulated light 13 (as shown by the straight arrow from top to bottom in the figure), and it substantially originates from the incident light 15 that passes through the collimating lens group 20 from the side of the collimating lens group 20 farther from the transparent wavelength conversion sheet 10 and is transmitted to the transparent wavelength conversion sheet 10. In order to separate the excitation light 11A from the collimated stimulated light 13, a dichroic mirror ( Figure 1 not shown in Figure 2 but shown as 107 in Figure 3A and shown as 207 in Figure 2 and Figure 3A ) can be arranged on the side of the reflective polarization beam splitter 40 opposite to the quarter-wave plate 30, and the dichroic mirror is configured to have an appropriate angle relative to other optical components of the polarization light source device (i.e., the collimating lens group 20, the quarter-wave plate 30, the reflective polarization beam splitter 40, etc.), so that the excitation light 11A incident on the polarization light source device can pass through each optical component (i.e., the reflective polarization beam splitter 40, the quarter-wave plate 30, and the collimating lens group 20) in a direction opposite to the optical path of the collimated stimulated light 13 and enter the transparent wavelength conversion sheet 10. The term "dichroic mirror" as used herein refers to a color filter that can selectively reflect specific light and transmit other light according to the wavelength of the light incident thereon. In Example 1 and Example 2 below, the dichroic mirror is arranged at an angle of about 45° with respect to the optical path of the stimulated light (or with respect to other optical components), so that the input light (i.e., the excitation light) incident on the polarization light source device and the output light emitted from the polarization light source device are configured to be at an angle of about 90° to each other, as shown in

[0049] Note that the angle between the dichroic mirror and other optical components does not necessarily need to be set to about 45°, but can optionally be any angle greater than 0° but less than 90° according to actual needs.

[0049] In this article, the dichroic mirror can have different arrangements. It can be located on the side of the reflective polarization beam splitter 40 opposite to or away from the quarter-wave plate 30, or alternatively between the quarter-wave plate 30 and the reflective polarization beam splitter 40, or alternatively between the collimating lens group 20 and the quarter-wave plate 30. In addition, the input light and the output light can have different configurations: Optionally, the output light can be configured to follow the optical path (i.e., Figure 1The upward arrow shown in [figure number] and the input light is configured to be perpendicular to the optical path such that the dichroic mirror is configured to reflect the input light and transmit the output light; alternatively, the input light can be configured to be along the opposite direction of the optical path and the output light is configured to be perpendicular to the optical path such that the dichroic mirror is configured to transmit the input light and reflect the output light. It should be noted that regardless of the configuration, the input light in these embodiments of the polarization light source device is configured to be collimated and linearly polarized light (whose polarization direction is substantially parallel to the transmission axis of the reflective polarization beam splitter 40), which can optionally be provided by a collimated light source of a laser diode or can optionally be the output light from other optical devices.

[0050] In these embodiments of the polarization light source device, a substrate (not shown in this figure) can be provided and the substrate is arranged below the transparent wavelength conversion sheet 10 (i.e., on the side of the transparent wavelength conversion sheet 10 opposite to the collimating lens group 20 and other optical components such as the quarter-wave plate 30, the reflective polarization beam splitter 40, etc.), and the reflective film layer 50 can be sandwiched between the substrate and the transparent wavelength conversion sheet 10. Preferably, the substrate can be a heat dissipation substrate (as shown in Example 1 and Example 2).

[0051] According to some other embodiments described in more detail in Example 3 and Example 4, the excitation light 11B enters or is incident on the transparent wavelength conversion sheet 10 in a direction parallel to the optical path direction of the collimated stimulated light 13 (as shown by the arrow from bottom to top in the figure). In these embodiments, there is no need to use a dichroic mirror, and the reflective film layer 50 can also be configured to transmit the excitation light 11B in addition to reflecting the stimulated light 12. It should be noted that in these embodiments, the reflective film layer 50 is substantially a dichroic film layer, and non-limiting examples can include a film layer that transmits blue light but reflects green light, a film layer that transmits blue light but reflects yellow light, or a film layer that transmits blue light but reflects red light, etc. In these embodiments of the polarization light source device, a transparent substrate (not shown in the figure) can be provided and the transparent substrate is arranged below the transparent wavelength conversion sheet 10 (i.e., on the side of the transparent wavelength conversion sheet 10 opposite to the collimating lens group 20 and other optical components such as the quarter-wave plate 30, the reflective polarization beam splitter 40, etc.), and the reflective film layer 50 can be sandwiched between the substrate and the transparent wavelength conversion sheet 10 (as shown in Example 3 and Example 4).

[0052] The stimulated light 12 emitted from the transparent wavelength conversion sheet 10 is unpolarized light. With the help of the reflective film layer 50 and the collimating lens group 20, the unpolarized stimulated light 12 can be collected and collimated so that the divergence angle of the collimated stimulated light 13 is less than about 20° (in this article, the divergence angle is defined with respect to the optical axis (Y axis) and can be ±20°), and then the collimated stimulated light 13 sequentially passes through the quarter-wave plate 30 and the reflective polarization beam splitter 40, thereby becoming the output stimulated light of the polarization light source device.

[0053] As used herein, the term "collimating lens group" refers to an optical lens group that can collimate or converge a light beam. The collimating lens group used herein can include one lens or a plurality of lenses arranged in an array. In addition, the transparent wavelength conversion sheet 10 can be substantially arranged at the focal plane of the collimating lens group 20.

[0054] In the polarization light source device, it is also configured such that the angle between the slow axis of the quarter-wave plate 30 and the transmission axis of the reflective polarization beam splitter 40 is configured to be about 45°.

[0055] As used herein, the term "quarter-wave plate" refers to a wave plate that is a quarter-wave with respect to the wavelength of the stimulated light. A quarter-wave plate can convert a linearly polarized light beam into a circularly polarized light beam and vice versa. In this article, an initial linearly polarized light beam can become a circularly polarized light beam after passing through a quarter-wave plate whose slow axis is arranged at an angle of about 45° with respect to the polarization direction of the linearly polarized light beam; and the circularly polarized light beam that is reflected back and allowed to pass through the quarter-wave plate again can become a linearly polarized light beam whose polarization direction is rotated by substantially 90° compared to the original linearly polarized light beam.

[0056] The term "reflective polarization beam splitter" refers to a polarizer that allows a specific component of a light beam having a polarization direction substantially parallel to the transmission axis (i.e., the optical axis) of the polarizer to pass through while reflecting other components of the light beam. Therefore, when unpolarized light passes through the polarizer (i.e., the reflective polarization beam splitter), it is decomposed or split into transmitted light and reflected light: the transmitted light has a polarization direction substantially parallel to the transmission axis of the polarizer, and the reflected light has a polarization direction substantially perpendicular to the transmission axis of the polarizer.

[0057] The polarization state of an unpolarized light beam such as the collimated stimulated light 13 passing through the collimating lens group 20 remains unchanged after passing through the quarter-wave plate.

[0058] A first portion of the light beam 13, whose polarization direction is substantially the same or substantially parallel to the transmission axis of the reflective polarization beam splitter 40 (i.e., the "polarizer"), passes through the reflective polarization beam splitter 40 and becomes the first output light.

[0059] A second portion of the light beam 13, whose polarization direction is substantially perpendicular to the transmission axis of the reflective polarization beam splitter 40, is reflected back to the quarter-wave plate 30 and also becomes a circularly polarized light beam after passing through the quarter-wave plate 30. The circularly polarized light beam continues to pass through the collimating lens group 20 and the transparent wavelength conversion plate 10, is reflected by the reflective film layer 50, and then returns to the quarter-wave plate 30 in the initial optical path. After passing through the quarter-wave plate 30, the circularly polarized light beam becomes a linearly polarized light beam whose polarization direction is rotated by substantially 90° with respect to the initial linearly polarized light beam (i.e., the second portion of the light beam 13). Since the polarization direction of the linearly polarized light beam is substantially parallel to the transmission axis of the polarizer 40, it can pass through the polarizer 40 and become the second output light. Subsequently, the second output light is combined with the first output light to become the output light 14 of the polarized light source.

[0060] Therefore, by means of the polarized light source provided in the present invention, the unpolarized light emitted by the light source is substantially converted into polarized light, and the light emitting area of the light source does not increase.

[0061] Hereinafter, a total of four specific examples will be provided in more detail, which represent four different embodiments of the polarized light source.

[0062] Example 1:

[0063] In this specific example, a first embodiment of the polarized light source device is provided as follows, as Figure 2 shown.

[0064] As shown in the figure, the polarized light source device 001 according to the first embodiment basically includes a transparent wavelength conversion plate 101, a collimating lens group 103, a quarter-wave plate 104, a reflective polarization beam splitter 105, and a dichroic mirror 107 arranged in a housing 108 for the polarized light source device 001.

[0065] The housing 108 is provided with two openings (i.e., the first opening 106 and the second opening 109 shown in the figure), which are respectively configured as an entrance for incident light (i.e., incident excitation light 112) and an exit for outgoing light (i.e., output light 114). In Figure 2 the specific embodiment of the polarized light source device 001 shown, the first opening 106 is configured as an entrance for incident light 112 (i.e., the light source device entrance), and the second opening 109 is configured as an exit for outgoing light 114 (i.e., the light source device exit). It should be noted that according to another embodiment of the polarized light source device 001 (not shown), the second opening 109 is configured as an entrance for incident light (i.e., the light source device entrance), and the first opening 106 is configured as an exit for outgoing light (i.e., the light source device exit).

[0066] Hereinafter, only for Figure 2The embodiments described in detail the specific configurations and working mechanisms of various optical components in the polarization light source device. That is, the first opening 106 and the second opening 109 are respectively configured as an entrance for light to enter (i.e., the entrance of the light source device) and an exit for light to exit (i.e., the exit of the light source device).

[0067] Specifically, within the housing 108 of the polarization light source device 001, the transparent wavelength conversion sheet 101, the collimating lens group 103, the quarter-wave plate 104, the reflective polarization beam splitter 105, and the dichroic mirror 107 are arranged in sequence towards the second opening 109 of the housing 108, as shown by the Y axis that is substantially parallel to the direction of the emitted light exiting through the second opening 109.

[0068] In this document, optionally, each of the above optical elements (i.e., the transparent wavelength conversion sheet 101, the collimating lens group 103, the quarter-wave plate 104, the reflective polarization beam splitter 105, and the dichroic mirror 107) can be fixedly arranged in the housing 108. This fixed configuration can be achieved in various ways. For example, as Figure 2 shown, each optical element is fixedly attached to the housing 108 through a connector 110 installed at a fixed position on the inner wall of the housing 108. In another example, each optical element can be fixedly attached to the inner wall of the housing 108 through an adhesive. In yet another example, each optical element can also be fixedly installed in a groove in the inner wall of the housing 108. Other connection methods are also possible.

[0069] In this document, the transparent wavelength conversion sheet 101 includes a transparent wavelength conversion material. In this specific example, the transparent wavelength conversion material used in the transparent wavelength conversion sheet 101 is the transparent fluorescent ceramic YAG:Ce 3+ (Y3Al5O 12 :Ce 3+ ), and the thickness of the transparent wavelength conversion sheet 101 is about 0.5 mm, the length is about 4 mm, and the width is about 4 mm (i.e., 4 mm × 4 mm × 0.5 mm). However, it should be noted that the transparent wavelength conversion material can optionally include another component (i.e., another transparent fluorescent ceramic, fluorescent glass, or fluorescent crystal), and the transparent wavelength conversion sheet 101 can have different dimensions or sizes. Non-limiting examples of materials that can be used as the transparent wavelength conversion material can optionally be selected from any of the components listed in Table 1.

[0070] Table 1: Examples of transparent wavelength conversion materials and their specific properties

[0071]

[0072] The lower surface of the transparent wavelength conversion sheet 101 (i.e., the surface of the transparent wavelength conversion sheet 101 opposite to the second opening 109 of the housing 108) is coated with a reflective film layer 101a, which is configured such that the reflective surface of the reflective film layer faces the second opening 109. Herein, the reflective film layer 101a can preferably have a high reflectivity to light in the wavelength range of about 420 nm to 660 nm. The term "high reflectivity" used herein is defined as not less than 90% (i.e., ≥90%).

[0073] The transparent wavelength conversion sheet 101 can optionally be configured to be attached to the heat dissipation substrate 102, which can be achieved by means such as heat-resistant adhesives, high-temperature welding, or clamping. Therefore, the heat generated during the operation of the polarized light source device 001 can be effectively dissipated through the heat dissipation substrate 102, which is beneficial to extending the service life of the polarized light source device 001. The heat dissipation substrate 102 can be made of materials with high thermal conductivity, such as metallic copper, aluminum, steel, etc., but can also be made of other materials, such as alloys (e.g., copper-aluminum alloy, etc.). In this specific example, the size of the heat dissipation substrate 102 is about 20 mm × 20 mm × 4 mm (length × width × thickness), but it can also have different sizes.

[0074] The transparent wavelength conversion sheet 101 is arranged substantially in the focal plane of the collimating lens group 103 such that the laser-excited light 113 emitted by the wavelength conversion material contained in the transparent wavelength conversion sheet 101 can be effectively collimated by the collimating lens group 103. In this specific example, the collimating lens group 103 includes a single convex lens (i.e., a double-sided convex lens), but can also optionally include two plano-convex lenses opposite to each other, or include a plurality of convex lenses arranged in an array in a plane perpendicular to the optical path of the light.

[0075] The quarter-wave plate 104 and the reflective polarization beam splitter 105 can be arranged such that the angle between the slow axis of the quarter-wave plate 104 and the transmission axis of the reflective polarization beam splitter 105 is about 45°.

[0076] The dichroic mirror 107 is configured to reflect the incident / entering light (i.e., the excitation light) 112 incident from the first opening 106 (i.e., the light source device entrance), and transmit the laser-excited light 113 passing through the dichroic mirror. In this specific example of the polarized light source device 001, the dichroic mirror 107 is arranged at an angle of about 45° with respect to other optical elements (i.e., the collimating lens group 103, the quarter-wave plate 104, the reflective polarization beam splitter 105, etc.), and this arrangement allows the incident excitation light 112 to enter the polarized light source device 001 in a direction perpendicular to the optical path of the laser-excited light 114 (i.e., the optical axis of the collimating lens group 103). It should be noted that the dichroic mirror 107 can optionally be arranged at an angle other than 45° with respect to other optical elements.

[0077] In this text, the incident excitation light 112 is configured as a collimated light beam and is also configured as linearly polarized light, the polarization direction of which is substantially parallel to the transmission axis of the reflective polarization beam splitter 105. Therefore, the incident excitation light 112 can optionally be provided by a light source collimated by a laser diode, or can optionally be the output light from other optical devices. The fluorescence 113 is unpolarized light. The emitted / output light 114 emitted from the polarization light source device 001 is linearly polarized light, and the polarization direction of which is substantially parallel to the transmission axis of the reflective polarization beam splitter 105. In this specific example, the excitation light 112 is blue light with a wavelength of about 420 nm to 470 nm, and the fluorescence 113 is yellow light with a wavelength of about 500 nm to 660 nm. However, according to other embodiments of the polarization light source device, the excitation light 112 and the fluorescence 113 can have different wavelengths.

[0078] The working principle of the above embodiment of the polarization light source device 001 is as follows:

[0079] The incident excitation light 112 enters the interior of the polarization light source device 001 from the light source device entrance (i.e., the first opening 106), and changes its propagation direction by 90° after being reflected by the dichroic mirror 107. Then, the excitation light 112 sequentially passes through the reflective polarization beam splitter 105 and the quarter-wave plate 104, and is also focused on the transparent wavelength conversion sheet 101 through the collimating lens group 103. During the excitation process, the excitation wavelength conversion material contained in the transparent wavelength conversion sheet 101 emits the fluorescence 113.

[0080] The fluorescence 113 is unpolarized light. A part of the fluorescence 113 can travel upward (i.e., in the direction of the light source device exit or the second opening 109), reach the collimating lens group 103, and a part of the fluorescence 113 can travel downward (i.e., in the direction opposite to the light source device exit or the second opening 109), reach the reflective film layer 101a arranged on the lower surface of the transparent wavelength conversion sheet 101, and thus be reflected upward again (i.e., in the direction of the second opening 109) and reach the collimating lens group 103 again.

[0081] After being collimated by the collimating lens group 103, the pump laser 113 passes through the quarter-wave plate 104, and the unpolarized light remains unpolarized after passing through the quarter-wave plate 104. The first part of the unpolarized light, whose polarization direction is substantially parallel to the transmission axis of the reflective polarization beam splitter 105, can pass through the reflective polarization beam splitter 105 and the dichroic mirror 107, and then be emitted from the light source device exit 109 to become the first output beam. The second part of the unpolarized light, whose polarization direction is perpendicular to the transmission axis of the reflective polarization beam splitter 105, is reflected back to the quarter-wave plate 104, passes through the collimating lens group 103 and the transparent wavelength conversion sheet 101 in sequence, and then is reflected by the reflective film layer 101a. The reflected light beam then returns along the original optical path and direction (i.e., upward toward the second opening 109), and after passing through the quarter-wave plate 104, the polarization direction of the reflected light beam rotates by 90°. At this time, since the polarization direction of the reflected light beam is substantially parallel to the transmission axis of the reflective polarization beam splitter 105, the reflected light beam will pass through the reflective polarization beam splitter 105, and then after passing through the reflective polarization beam splitter 105 and the dichroic mirror 107, it will be emitted from the light source exit 109 to become the second output beam, and the second output beam is substantially combined with the first output beam to form the light source output beam 114.

[0082] In addition to the specific embodiments of the polarization light source device as Figure 2 illustrated and described above, there can be other variations according to different embodiments.

[0083] According to a specific variant embodiment (not shown), the arrangement of each component (i.e., the transparent wavelength conversion sheet 101, the collimating lens group 103, the quarter-wave plate 104, the reflective polarization beam splitter 105, the dichroic mirror 107, and the housing 108) of the polarization light source device is substantially the same as the arrangement in the above-described embodiment of the polarization light source device as Figure 2 illustrated. However, on the contrary, the first opening 106 and the second opening 109 in the housing 108 are respectively configured as an exit for emitting light (i.e., the light source device exit) and an entrance for incident pump light (i.e., the light source device entrance). Accordingly, the dichroic mirror 107 in this embodiment of the polarization light source device is configured to transmit the incident / incident light (i.e., the pump light) incident from the second opening 109 (i.e., the light source device entrance) through the dichroic mirror, and reflect the pump laser on the dichroic mirror to allow it to exit through the first opening 106 (i.e., the light source device exit). It should also be noted that in the same way as Figure 2In the same manner as the illustrated embodiment, the incident excitation light in this embodiment is similarly configured as collimated and linearly polarized light (the polarization direction of which is substantially parallel to the transmission axis of the reflective polarization beam splitter 105), which can optionally be provided by a laser diode-collimated light source, or can optionally be the output light from other optical devices.

[0084] According to a specific other variant embodiment (not shown), the polarization light source device further includes each of the components in the above-described embodiment of the polarization light source device as Figure 2 shown (i.e., the transparent wavelength conversion sheet 101, the collimating lens group 103, the quarter-wave plate 104, the reflective polarization beam splitter 105, the dichroic mirror 107, and the housing 108), and has a similar configuration for these components, but the arrangement of the dichroic mirror 107 and its corresponding first opening 106 is different from that of the Figure 2 illustrated embodiment, and it can alternatively be arranged between the collimating lens group 103 and the quarter-wave plate 104, or can alternatively be arranged between the quarter-wave plate 104 and the reflective polarization beam splitter 105. It should be noted that in these embodiments, the first opening 106 and the second opening 107 can optionally be the entrance and exit of the polarization light source device respectively, or can optionally be the exit and entrance of the polarization light source device respectively.

[0085] Example 2:

[0086] Example 2 describes a second embodiment of the polarization light source device. As Figure 3A shown in the schematic diagram, this second embodiment of the polarization light source device is basically a variant of the first embodiment (i.e., Example 1) of the above-described polarization light source device.

[0087] In a configuration similar to that of the polarization light source device 001 of the first embodiment shown in Figure 2 and described in Example 1, as Figure 3A shown, the polarization light source device 002 of the second embodiment basically also includes a transparent wavelength conversion sheet 201, a collimating lens group 203, a quarter-wave plate 204, a reflective polarization beam splitter 205, and a dichroic mirror 207, which are sequentially arranged toward the second opening 209 of the housing 208, as shown by the Y axis substantially parallel to the direction of the outgoing light emitted through the second opening 209. The housing 208 is also provided with a first opening 206 for the entrance of the light source device of the incident excitation light 212, and is also provided with a second opening 209 for the exit of the output / emergent light 214 of the light source device. The angle between the slow axis of the quarter-wave plate 204 and the transmission axis of the reflective polarization beam splitter 205 is about 45°. The configuration of each of the above optical components and the working mechanism of the light source device are similar to those described in Example 1 above, and therefore, reference can be made to the description of Example 1, which will not be elaborated here.

[0088] The difference between the first embodiment 001 and the second embodiment 002 of the polarized light source device is that the transparent wavelength conversion sheet 201 in the second embodiment 002 has a wheel shape (or an annular shape) and can include more than one transparent wavelength conversion material. As in Figure 3B one illustrative example shown, the transparent wavelength conversion sheet 201 basically includes two parts: a first part 201M and a second part 201N, which include a first transparent wavelength conversion material and a second transparent wavelength conversion material, respectively. In other examples, the transparent wavelength conversion sheet 201 can optionally include more than two parts, each part including a different transparent wavelength conversion material. Herein, each different transparent wavelength conversion material is configured to be able to emit different stimulated light (i.e., having different wavelengths) when excited by the same excitation light. In a specific example, the thickness of the transparent wavelength conversion sheet 201 is 0.5 mm, and the inner diameter of the annular shape of the transparent wavelength conversion sheet 201 is 16 mm and the outer diameter is 20 mm. In addition, the first part 201M of the transparent wavelength conversion sheet 201 has a first transparent fluorescent ceramic LuAG:Ce 3+ composition, which can emit green light when excited by incident blue light; the second part 201N of the transparent wavelength conversion sheet 201 has a second transparent fluorescent ceramic YAG:Mn / Mg composition, which can emit red light when excited by incident blue light. However, it should be noted that the above only represents an illustrative example and does not mean any limitation on the size and / or composition of the transparent wavelength conversion sheet 201.

[0089] As Figure 3A shown, the lower surface of the transparent wavelength conversion sheet 201 (i.e., the surface of the transparent wavelength conversion sheet 201 opposite to the second opening 209 of the housing 208) is similarly coated with a reflective film layer 201a, configured such that the reflective surface of the reflective film layer faces the second opening 209. In addition, the annular transparent wavelength conversion sheet 201 is fixedly attached to the heat dissipation substrate 202, and the heat dissipation substrate is mounted on the rotating shaft 210. The rotating shaft 210 is operably connected to a drive motor (not shown) fixedly attached to the light source housing 208 and is configured to rotate about a rotation axis substantially parallel to the direction of the emitted light emitted through the light source device outlet (i.e., the second opening 209), as shown by the Y axis. When the light source device is operating, the rotating shaft 210 drives the heat dissipation substrate 202 and the transparent wavelength conversion sheet 201 to rotate at a preset speed.

[0090] Similar to Example 1, according to different embodiments of the polarized light source device, Example 2 can have similar variations. For example, the first opening 206 and the second opening 209 in the housing 208 can be respectively configured as the light source device outlet and the light source device inlet; and correspondingly, the dichroic mirror 207 is configured to transmit the incident excitation light incident through the second opening 209 through the dichroic mirror and reflect the laser light on the dichroic mirror to allow it to exit through the first opening 106. In addition, the dichroic mirror 207 and the corresponding first opening 206 can be alternatively arranged between the collimating lens group 203 and the quarter-wave plate 204, or can be alternatively arranged between the quarter-wave plate 204 and the reflective polarization beam splitter 205. Regardless of the various different embodiments described above, the incident excitation light can be configured as collimated and linearly polarized light (whose polarization direction is substantially parallel to the transmission axis of the reflective polarization beam splitter 205), which can optionally be provided by a light source collimated by a laser diode, or can optionally be the output light from other optical devices.

[0091] Compared with the polarized light source device 001 of the first embodiment shown in Example 1, the polarized light source device 002 of the second embodiment can emit polarized light of different wavelengths in chronological order (i.e., in the order of time), and the heat dissipation performance is also improved.

[0092] Example 3:

[0093] In this example, Figure 4 a schematic diagram of the third embodiment of the polarized light source device is shown.

[0094] As shown in the figure, the polarized light source device 003 according to this third embodiment basically includes a transparent wavelength conversion sheet 301, a collimating lens group 303, a quarter-wave plate 304, and a reflective polarization beam splitter 305 arranged in a housing 308. The housing 308 is provided with a first opening 306 and a second opening 309, and the first opening 306 and the second opening 309 are respectively used as the inlet for the incident excitation light 312 of the light source device 003 and the outlet for the output / emergent light 314 of the light source device 003. More specifically, the transparent wavelength conversion sheet 301, the collimating lens group 303, the quarter-wave plate 304, and the reflective polarization beam splitter 305 are sequentially arranged in the direction from the first opening 306 to the second opening 309 of the housing 308 (as shown by the Y axis substantially parallel to the direction of the optical path of the light). The angle between the slow axis of the quarter-wave plate 304 and the transmission axis of the reflective polarization beam splitter 305 is arranged to be about 45°.

[0095] Compared with the polarization light source device 001 of the first embodiment described in the above Example 1, in the polarization light source device 003 of this third embodiment, both the top surface and the bottom surface of the transparent wavelength conversion sheet 301 are light-transmitting surfaces, and thus no reflective film layer is arranged in the polarization light source device 003 of the third embodiment.

[0096] As Figure 4 shown, the polarization light source device 003 of this third embodiment further includes a transparent substrate 311 located below the transparent wavelength conversion sheet 301 (i.e., on the surface of the transparent wavelength conversion sheet 301 facing the first opening 306). The transparent substrate 311 includes a transparent material such as optical glass, quartz glass, and other materials, which allows the excitation light incident from the first opening 306 (i.e., the light source device entrance) to pass through and irradiate the transparent wavelength conversion sheet 301.

[0097] In addition, a dichroic film layer 311a is arranged between the transparent wavelength conversion sheet 301 and the transparent substrate 311, and the dichroic film layer can be coated on the bottom surface of the transparent wavelength conversion sheet 301 or the upper surface of the transparent substrate 311. The dichroic film layer 311a is configured to be able to transmit the incident excitation light 312 to pass through the dichroic film layer and reflect the stimulated emission light 313 on the dichroic film layer. It should be noted that there is no dichroic mirror in the polarization light source device 003 of this third embodiment.

[0098] The working mechanism of the polarization light source device 003 of the third embodiment is as follows:

[0099] The incident excitation light 312 enters the interior of the light source device 003 from the light source device entrance (i.e., the first opening 306). After passing through the transparent substrate 311 and the dichroic film layer 311a, the excitation light 312 irradiates on the transparent wavelength conversion sheet 301, and then the excitation wavelength conversion material contained in the transparent wavelength conversion sheet 301 emits the stimulated emission light 313.

[0100] The stimulated emission light 313 is unpolarized light. A part of the stimulated emission light 313 can travel upward (i.e., in the direction of the light source device exit or the second opening 309) to reach the collimating lens group 303, and a part of the stimulated emission light 313 can travel downward (i.e., in the direction of the light source device entrance or the first opening 306) to reach the dichroic film layer 311a, where it is reflected upward again (i.e., in the direction of the second opening 309), and thus further reaches the collimating lens group 303.

[0101] After being collimated by the collimating lens group 303, the pumping laser 313 passes through the quarter-wave plate 304, and the non-polarized light remains non-polarized after passing through the quarter-wave plate 304. The first part of the non-polarized light, whose polarization direction is substantially parallel to the transmission axis of the reflective polarization beam splitter 305, can pass through the reflective polarization beam splitter 305 and then be emitted from the light source device outlet 309 to become the first output beam. The second part of the non-polarized light, whose polarization direction is perpendicular to the transmission axis of the reflective polarization beam splitter 305, is reflected back to the quarter-wave plate 304, passes through the collimating lens group 303 and the transparent wavelength conversion sheet 301 in sequence, and then is reflected by the dichroic film layer 311a. The reflected light beam then returns along the original optical path, and after passing through the quarter-wave plate 304, the polarization direction of the reflected light beam rotates by 90°. At this time, since the polarization direction of the reflected light beam is substantially parallel to the transmission axis of the reflective polarization beam splitter 305, it will pass through the reflective polarization beam splitter 305, and then after passing through the reflective polarization beam splitter 305, it will be emitted from the light source outlet 309 to become the second output beam, and then the second output beam is combined with the first output beam to thus become the light source output beam 314.

[0102] Compared with the polarization light source device 001 of the first embodiment, the volume of the polarization light source device 003 of the third embodiment is reduced, and the pumping light 312 can be non-polarized light, such as the light emitted by an LED light source. It should be noted that for Example 3, according to some other embodiments, the pumping light 312 can optionally be polarized light or a combination of polarized light and non-polarized light.

[0103] Example 4:

[0104] Example 4 describes the polarization light source device of the fourth embodiment. As Figure 5 shown in the schematic diagram, the polarization light source device 004 of the fourth embodiment is substantially a variant of the polarization light source device (i.e., Example 3) of the above third embodiment.

[0105] In Figure 4In a configuration similar to the polarization light source device 003 of the third embodiment shown, the polarization light source device 004 of this fourth embodiment also basically includes a transparent substrate, a transparent wavelength conversion sheet 401, a collimating lens group 403, a quarter-wave plate 404, and a reflective polarization beam splitter 405 arranged in sequence in the direction from the first opening 406 to the second opening 409 of the housing 408, as shown by the Y axis that is substantially parallel to the optical path direction of the light incident from the first opening 406 (i.e., the light source entrance for the incident excitation light 412) and exiting from the second opening 409 (i.e., the light source exit for the output / emitted light 414). The angle between the slow axis of the quarter-wave plate 404 and the transmission axis of the reflective polarization beam splitter 405 is arranged to be approximately 45°. The configuration of each of the above optical components and the working mechanism of the light source device are similar to those described in the above Example 3, and therefore, reference can be made to the description of Example 3, which will not be repeated here.

[0106] Similar to the polarization light source device 003 of the third embodiment, both surfaces (i.e., the top surface and the bottom surface) of the transparent wavelength conversion sheet 401 are light-transmissive surfaces. The main difference between the third embodiment 003 and the fourth embodiment 004 of the polarization light source device is that the transparent wavelength conversion sheet 401 in the fourth embodiment 004 has a wheel shape (or an annular shape) and can include more than one transparent wavelength conversion material, with each material arranged in an annular sub-region. The configuration of the annular transparent wavelength conversion sheet 401 in the fourth embodiment 004 is similar to Figure 2 the annular transparent wavelength conversion sheet 201 of the polarization light source device 002 of the second embodiment shown in B.

[0107] As Figure 5 shown, the annular transparent wavelength conversion sheet 401 is fixedly attached to the transparent substrate 411, and the transparent substrate is mounted on the rotating shaft 410. Similar to the polarization light source device 003 of the third embodiment, a dichroic film layer 411a that can transmit the excitation light 412 but reflect the laser light is similarly arranged between the transparent wavelength conversion sheet 401 and the transparent substrate 411. The rotating shaft 410 is operably connected to a drive motor (not shown) fixedly attached to the light source housing 408 and is configured to rotate about a rotation axis that is substantially parallel to the direction of the emitted light emitted through the light source device exit (i.e., the first opening) 409, as shown by the Y axis. When the light source device operates, the rotating shaft 410 drives the transparent substrate 411 and the transparent wavelength conversion sheet 401 to rotate at a preset speed.

[0108] Compared with the polarization light source device 002 of the second embodiment, the volume of the polarization light source device 004 of this third embodiment is reduced, and the excitation light 412 can be non-polarized light, such as the light emitted by an LED light source. It should also be noted that in Example 4, according to some other embodiments, the excitation light 312 can optionally be polarized light or a combination of polarized light and non-polarized light.

Claims

1. A polarized light source device, comprising a transparent wavelength conversion sheet, a collimating lens group, a quarter-wave plate, and a reflective polarization beam splitter arranged in sequence along an optical path, wherein: The transparent wavelength conversion sheet is arranged at approximately the focal plane of the collimating lens group and is configured to emit stimulated light when receiving excitation light; The collimating lens group is configured to collimate the stimulated light, thereby generating collimated stimulated light; And The quarter-wave plate is configured such that the angle between its slow axis and the transmission axis of the reflective polarization beam splitter is approximately 45°.

2. The polarization light source device according to claim 1, wherein, The angle between the direction of the excitation light and the optical path is less than approximately 35°.

3. The polarization light source device according to claim 2, wherein The angle between the direction of the excitation light and the optical path is approximately 0°.

4. The polarized light source device according to any one of claims 1 to 3, wherein: The excitation light irradiates the transparent wavelength conversion sheet from a side of the transparent wavelength conversion sheet close to the collimating lens group; and The polarized light source device further comprises a reflective film layer on a side of the transparent wavelength conversion sheet away from the collimating lens group, the reflective film layer having a reflective surface facing the transparent wavelength conversion sheet, wherein the reflective film layer is configured to reflect at least a part of the stimulated light from the transparent wavelength conversion sheet back to the collimating lens group.

5. The polarized light source device according to claim 4, wherein: The excitation light source is the first incident light that transmits through the collimating lens group from a side of the collimating lens group away from the transparent wavelength conversion sheet towards the transparent wavelength conversion sheet, and The polarized light source device further comprises a dichroic mirror arranged on a side of the collimating lens group away from the transparent wavelength conversion sheet, wherein the dichroic mirror is configured to: Allow the first input light entering the polarized light source device to be reflected on the dichroic mirror, thereby providing the first incident light; Or Allow the second input light entering the polarized light source device to transmit through the dichroic mirror, thereby providing the first incident light.

6. The polarization light source device according to claim 5, wherein The dichroic mirror is arranged at: Between the collimating lens group and the quarter-wave plate; Between the quarter-wave plate and the reflective polarization beam splitter; or On a side of the reflective polarization beam splitter away from the quarter-wave plate.

7. The polarization light source device according to claim 5 or claim 6, wherein, The dichroic mirror is arranged at an angle of approximately 30° to 60° with respect to the optical path.

8. The polarization light source device according to claim 7, wherein, The dichroic mirror is arranged at an angle of approximately 45° with respect to the optical path.

9. The polarization light source device according to any one of claims 5 to 8, wherein, The dichroic mirror is arranged on a side of the reflective polarization beam splitter away from the quarter-wave plate and is configured to allow the first input light to be reflected thereon, thereby providing the first incident light, wherein the dichroic mirror is further configured to allow the derivative light of the stimulated light to transmit through the dichroic mirror to become the first output light emitted from the polarized light source device.

10. The polarization light source device according to any one of claims 5 to 8, wherein, The dichroic mirror is disposed on a side of the reflective polarization beam splitter away from the quarter-wave plate, and is configured to allow the second input light to transmit through the dichroic mirror, thereby providing the first incident light, wherein the dichroic mirror is further configured to allow the derivative light of the lasing light to be reflected on the dichroic mirror, so as to thereby become the second output light emitted from the polarization light source device.

11. The polarization light source device according to any one of claims 5 to 10, further comprising a first housing, wherein: The transparent wavelength conversion sheet, the collimating lens group, the quarter-wave plate, the reflective polarization beam splitter, and the dichroic mirror are all disposed in the first housing; And The first housing is provided with: An inlet that allows input light to enter the polarization light source device through the inlet; And An outlet that allows output light to be emitted from the polarization light source device through the outlet.

12. The polarization light source device according to claim 11, wherein, The first housing is provided with a reflective inner surface.

13. The polarization light source device according to any one of claims 5 to 12 further includes a heat dissipation substrate on a side of the reflective film layer away from the transparent wavelength conversion sheet, wherein, The heat dissipation substrate is attached to the transparent wavelength conversion sheet and is configured to dissipate the heat released from the transparent wavelength conversion sheet when the polarization light source device is operating.

14. The polarization light source device according to claim 13, wherein, The reflective film layer is integrated with the heat dissipation substrate, and a side surface of the heat dissipation substrate facing the transparent wavelength conversion sheet is configured to be reflective.

15. The polarization light source device according to any one of claims 5 to 14, wherein, The first incident light includes linearly polarized light, and a polarization direction of the linearly polarized light is substantially parallel to a transmission axis of the reflective polarization beam splitter.

16. The polarization light source device according to claim 15, wherein, The linearly polarized light is substantially collimated.

17. The polarization light source device according to claim 15 or claim 16, wherein, The first incident light source is the input light provided by a free laser diode light source.

18. The polarization light source device according to any one of claims 1 to 3, wherein, The excitation light irradiates the transparent wavelength conversion sheet from a side of the transparent wavelength conversion sheet away from the collimating lens group.

19. The polarization light source device according to claim 18, wherein: The excitation light source is the second incident light transmitted from a side of the transparent wavelength conversion sheet away from the collimating lens group toward the reflective polarization beam splitter; and The polarization light source device further comprises a dichroic film layer disposed on a side of the transparent wavelength conversion sheet away from the collimating lens group, wherein the dichroic film layer is configured to allow the second incident light to transmit through the dichroic film layer to thereby provide the excitation light, and reflect at least a part of the lasing light from the transparent wavelength conversion sheet back to the reflective polarization beam splitter along the optical path.

20. The polarization light source device according to claim 19, further comprising a transparent substrate on a side of the dichroic film layer away from the transparent wavelength conversion sheet, and the transparent substrate is configured to allow the second incident light to transmit through the transparent substrate.

21. The polarization light source device according to any one of claims 19 to 20, further comprising a second housing, wherein: The transparent wavelength conversion sheet, the collimating lens group, the quarter-wave plate, and the reflective polarization beam splitter are all disposed in the second housing; and The second housing is provided with an inlet that allows the second incident light to enter the polarization light source device through the inlet.

22. The polarization light source device according to claim 21, wherein, The second housing is provided with a reflective inner surface.

23. The polarization light source device according to any one of claims 19 to 22, wherein, The second incident light includes unpolarized light or polarized light.

24. The polarization light source device according to claim 23, wherein, The second incident light includes unpolarized light provided by a light-emitting diode (LED) light source.

25. The polarization light source device according to any one of claims 1 to 24, wherein, The transparent wavelength conversion sheet is configured to be adjustably movable in a plane perpendicular to the optical path.

26. The polarization light source device according to claim 25, wherein, The transparent wavelength conversion sheet includes at least two portions, each portion including a different material selected from a reflective material, a transparent material, or a transparent wavelength conversion material. The transparent wavelength conversion sheet is configured to be adjustably movable such that the at least two portions of the transparent wavelength conversion sheet are alternately arranged in the optical path, so that the polarization light source device alternately generates different output lights.

27. The polarization light source device according to claim 26, wherein, The transparent wavelength conversion sheet is composed of three portions configured to cause the polarization light source device to alternately generate three different output lights having three different primary colors.

28. The polarization light source device according to claim 27, wherein, The three portions respectively include three different transparent wavelength conversion materials configured to respectively stimulate three lights having three different primary colors when receiving the excitation light.

29. The polarization light source device according to claim 27, wherein: Two of the three portions respectively include two different transparent wavelength conversion materials configured to respectively stimulate two stimulated lights having two different colors when receiving the excitation light; and The last one of the three portions includes one of a transparent material or a reflective material. The transparent material allows the excitation light to transmit through the transparent material, and the reflective material allows the excitation light to be reflected back from the reflective material.

30. The polarization light source device according to claim 29, wherein, The excitation light is blue light, and the two stimulated lights are composed of green light and red light.

31. The polarization light source device according to claim 30, wherein: The excitation light is blue light having a wavelength of 455 nm; and The two different transparent wavelength conversion materials respectively include: Selected from LuAG:Ce 3+ or a first green light-stimulating component of MgAlON:Mn; and Selected from YAG:Mn / Mg, CaAlSiN3:Eu 2+ , Sr2Si5N8:Eu 2+ or CaAlSiN3:Eu 2+ The second red light stimulating component.

32. The polarization light source device according to claim 29, wherein, The excitation light is blue light, and the two stimulated lights are composed of yellow light and red light. The polarization light source device further includes a color filter configured to generate green light from the yellow light.

33. The polarization light source device according to claim 32, wherein: The excitation light is blue light having a wavelength of 455 nm; and The two different transparent wavelength conversion materials respectively include: YAG:Ce 3+ (Y3Al5O 12 :Ce 3+ )'s first yellow light stimulation component; and Selected from YAG:Mn / Mg, CaAlSiN3:Eu 2+ , Sr2Si5N8:Eu 2+ or CaAlSiN3:Eu 2+ The second red light stimulating component.

34. The polarization light source device according to any one of claims 25 to 33, wherein, At least two portions of the transparent wavelength conversion sheet are arranged at different sector regions of a circle or different segments of a ring, and the transparent wavelength conversion sheet is configured to be adjustably rotated around an axis, and the rotation axis of the axis is substantially located at the center of the circle or the center of the ring.

35. The polarization light source device according to claim 34, wherein The transparent wavelength conversion sheet is configured to rotate at a speed of at least 2400 revolutions per minute.

36. The polarization light source device according to any one of claims 1 to 35, wherein, The collimating lens group includes a single convex lens (i.e., a double-sided convex lens), two plano-convex lenses opposite to each other, or a plurality of convex lenses arranged in an array in a plane perpendicular to the optical path.

37. The polarization light source device according to any one of claims 1 to 36, wherein The collimated stimulated light emitted from the collimating lens group toward the reflective polarization beam splitter has a divergence angle with respect to the optical path of less than about 20°.

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