Light source system and projection device
By setting a first grating and a second grating in the light source system, unpolarized light is converted into two beams with the same polarization direction, and their emission direction is adjusted, thus solving the problem of low beam energy utilization and achieving efficient beam energy utilization and improved projection display effect.
Patent Information
- Application Number
- CN202422753009.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-12
- Publication Date
- 2025-11-04
- Estimated Expiration
- 2034-11-12
AI Technical Summary
Traditional light source systems have low beam energy utilization when converting unpolarized light into usable polarized light, which affects the display effect and cost of projection devices.
A first grating and a second grating are set in the light source system. The first grating converts the initial beam into two beams with the same polarization direction, and the second grating adjusts the exit direction of one of the beams to make it an incident aperture, thereby improving the beam energy utilization rate.
With the optical extension remaining constant or changing only slightly, the beam energy utilization rate is greatly improved, the purity of the projected image is enhanced, and the manufacturing cost is reduced.
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Figure CN223513398U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the field of optical technology, in particular to a light source system and a projection device. BACKGROUND
[0002] An augmented reality (AR) display device can capture real-world information in real time and combine virtual information, images, etc. with the real world. The augmented reality (AR) display device generally includes a projection device for generating image light and an optical combiner capable of combining actual ambient light and image light so that the human eye can simultaneously observe the environment and image information generated by the light machine. When a passive light-emitting display chip is used as an image source in the projection device, the passive light-emitting display chip needs to work under the condition of polarized light as a polarization modulation device, and a polarized light source needs to be used for illumination. However, the light beam energy utilization rate is low when the non-polarized light is converted into usable polarized light in the traditional light source system. CONTENT OF THE UTILITY MODEL
[0003] In a first aspect, the present application provides a light source system, which comprises: a light source configured to emit an initial light beam; a first grating disposed in the emission direction of the initial light beam, the first grating being configured to adjust the polarization direction of the received initial light beam and emit a first light beam and a second light beam having the same polarization direction, the emission directions of the first light beam and the second light beam being different; and a diaphragm disposed in the light emission direction of the first grating, the diaphragm comprising a first light entry region and a second light entry region provided with a second grating, the diaphragm being configured to transmit a light beam incident on the diaphragm in the emission direction of the first light beam, wherein the light beam in the first light beam having a divergence angle within a preset angle range is projected onto the first light entry region, and a target light beam in the second light beam having a divergence angle within the preset angle range is projected onto the second grating; and the second grating is configured to adjust the emission direction of the received target light beam so that the adjusted target light beam is incident on the diaphragm in the emission direction of the first light beam.
[0004] Optionally, the initial light beam comprises first polarized light and second polarized light; the first grating is configured to transmit the first polarized light incident in a first direction and emit the first light beam emitted in the first direction to the diaphragm; and the first grating is configured to adjust the emission direction and polarization direction of the second polarized light incident in the first direction and emit the second light beam emitted in a second direction to the diaphragm.
[0005] Optionally, the first grating comprises a liquid crystal polarization volume holographic grating, the first polarized light has a first spiral direction, the second polarized light has a second spiral direction, the first spiral direction is opposite to the second spiral direction, and the first spiral direction is the same as a liquid crystal spiral direction of the liquid crystal polarization volume holographic grating; the liquid crystal polarization volume holographic grating is used for transmitting the first polarized light with the same liquid crystal spiral direction to obtain the first light beam with the first spiral direction; the liquid crystal polarization volume holographic grating is used for adjusting the polarization direction of the second polarized light with the opposite liquid crystal spiral direction, and diffracting the second polarized light to obtain the second light beam with the first spiral direction and the second direction.
[0006] Optionally, the second grating is used for adjusting the exit direction of the target light beam received and incident in the second direction, so that the adjusted target light beam is incident on the diaphragm in the first direction.
[0007] Optionally, the second grating comprises a volume holographic grating, and the target light beam incident in the second direction satisfies a Bragg condition of the volume holographic grating.
[0008] Optionally, a relative distance between the first grating and the second grating is a set distance D:
[0009] D=A / B*d;
[0010] Wherein, A is an included angle between a line connecting a center of the first grating and a center of the diaphragm and an optical axis of the diaphragm, B is an included angle between exit directions of the first light beam and the second light beam, and d is a spot radius of an initial light beam projected to the first grating.
[0011] Optionally, the light source system further comprises a collimating lens, the collimating lens is arranged between the light source and the first grating, and the collimating lens is used for collimating processing the initial light beam and projecting the collimated initial light beam to the first grating.
[0012] In a second aspect, the application provides a projection device, the projection device comprising a housing and a light source system as described above, and the light source system is arranged in the housing.
[0013] The light source system provided in the application comprises a first grating arranged in the emission direction of the light source, the first grating is used to convert the initial light beam without polarization into two light beams with the same polarization direction and different emission directions, and a second grating is arranged to adjust the emission direction of one of the two light beams, so that the light beams with the divergence angle within the preset angle range in the two light beams are finally output after being incident on the diaphragm in the same direction, thereby greatly improving the light beam energy utilization rate in the light source system without changing or with small changes in the optical extension of the light source system.
[0014] These aspects or other aspects of the application will be more apparent in the following description of the embodiments. BRIEF DESCRIPTION OF DRAWINGS
[0015] In order to more clearly illustrate the technical solutions in the embodiments of the application, the following will briefly introduce the drawings needed to be used in the embodiment description. Obviously, the drawings in the following description are only some embodiments of the application, and for those skilled in the art, other drawings can also be obtained without creative labor.
[0016] Figure 1 The structure schematic diagram of the light source system provided by an embodiment of the application is shown.
[0017] Figure 2 The structure schematic diagram of the light source system provided by another embodiment of the application is shown.
[0018] Figure 3 The structure schematic diagram of the projection device provided by an embodiment of the application is shown. DETAILED DESCRIPTION
[0019] In order to make the personnel in the technical field better understand the application scheme, the technical solutions in the embodiments of the application will be clearly and completely described below in combination with the drawings in the embodiments of the application. Obviously, the described embodiments are only some of the embodiments of the application, not all. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the application.
[0020] The terms "first", "second", etc. in the application are used to distinguish different objects, not to describe a specific order. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device including a series of steps or units is not limited to the listed steps or units, but can optionally include steps or units not listed, or can optionally include other steps or units inherent to the process, method, product or device.
[0021] Reference to“an embodiment” herein means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearances of the phrase“in
[0022] Reference is made to Figure 1 , Figure 1 A structure schematic diagram of a light source system 1 provided by an embodiment of the application is shown. The light source system 1 provided by the embodiment of the application will be described in detail below. As shown in Figure 1 The light source system 1 provided by the embodiment of the application will be described in detail below. As shown in Figure 1 The light source system 1 provided by the embodiment of the application will be described in detail below. As shown in
[0023] Optionally, the light source 10 in the light source system 1 is configured to emit an initial light beam. In some application scenarios, the light source system 1 is configured to provide illumination for a passive light-emitting display chip in a projection device, and the light source 10 in the light source system 1 can be a light-emitting diode or a laser. If a plurality of monochromatic lasers are used to superimpose as a polarized light source, the projection display has the problem of low purity. Compared with the laser, the light-emitting diode can improve the purity of the projection display when it is used to provide illumination for the projection device. However, since the light-emitting diode is a non-polarized light source with a large divergence angle and a large optical etendue, and is limited by the optical etendue of the passive light-emitting display chip as a rear-end optical element, the energy utilization rate of the light beam is low in the process of converting the light beam emitted by the light-emitting diode into polarized light that can be received by the passive light-emitting display chip.
[0024] In the embodiment, the light source 10 can be a light-emitting diode. When the light-emitting diode is used to provide illumination for the projection device, the initial light beam emitted by the light source 10 is a non-polarized white light beam, which can improve the purity of the final projection display. In addition, the light-emitting diode has the advantage of low price, thereby reducing the manufacturing cost of the projection device in which the light source system 1 is located.
[0025] Optionally, the first grating 20 is arranged in the emission direction of the initial light beam emitted by the light source 10, and the first grating 20 is configured to adjust the polarization direction of the received initial light beam emitted by the light source 10, and emit the first light beam and the second light beam with the same polarization direction, and the emission directions of the first light beam and the second light beam are inconsistent. Based on this, in order to obtain polarized light, compared with the traditional selective transmission of the initial light beam with the same polarization direction by the polarizer, the polarizer causes the loss of the polarized light with the opposite polarization direction, in the embodiment of the present application, the first grating 20 is arranged in the emission direction of the light source 10, and the sub-beams with different polarization directions in the initial light beam can be converted into the same polarization direction for output, thereby greatly improving the utilization rate of the initial light beam emitted by the light source 10.
[0026] Further, the light source system 1 provided by the embodiment of the present application further comprises a diaphragm 30 and a second grating 40, and the diaphragm 30 limits the size of the light beam finally emitted by the light source system 1. The diaphragm 30 is arranged in the light emission direction of the first grating 20, and the diaphragm 30 comprises a first light entry area and a second light entry area provided with the second grating 40. Among them, after the first grating 20 converts the non-polarized initial light beam emitted by the light source 10 into the first light beam and the second light beam with different emission directions, for the diaphragm 30 arranged in the light emission direction of the first grating 20, the diaphragm 30 is configured to transmit the light beam incident into the diaphragm 30 with the emission direction of the first light beam.
[0027] Optionally, when the light source 10 is a light-emitting diode, the light emission of the light source 10 has the characteristics of a Lambert light source, and the first light beam and the second light beam with inconsistent emission directions formed after the initial light beam passes through the first grating 20 have a certain divergence angle. Since the optical expansion of the first grating 20 is greater than the optical expansion of the diaphragm 30, the first light beam and the second light beam emitted by the first grating 20 cannot all pass through the diaphragm 30.
[0028] In the embodiment, the planes where the first grating 20, the second grating 40 and the diaphragm 30 are located are parallel to each other, the first light beam emitted by the first grating 20 propagates forward in the light source system 1, and the incident direction of the first light beam projected to the diaphragm 30 is parallel to the optical axis direction of the diaphragm 30. The first light beam incident into the diaphragm 30 has a certain divergence angle, and when the light beam with the divergence angle within the preset angle range in the first light beam emitted by the first grating 20 is projected to the first light entry area of the diaphragm 30, the diaphragm 30 is configured to transmit the light beam with the divergence angle within the preset angle range in the first light beam.
[0029] Optionally, since the emission direction of the second beam emitted from the first grating 20 has a certain angle with the emission direction of the first beam, that is, the second beam emitted from the first grating 20 propagates obliquely in the light source system 1, the incident direction of the second beam projected to the aperture 30 has a certain angle with the optical axis direction of the aperture 30, making it difficult for the second beam to pass through the aperture 30.
[0030] Based on this, if the second incident area of the aperture 30 is located in the propagation direction of the second beam when it propagates obliquely in the light source system 1, a second grating 40 is provided at the second incident area of the aperture 30. The second grating 40 is used to adjust the exit direction of the received beam. Specifically, when a target beam with a divergence angle within a preset angle range is projected onto the second grating 40 at the second incident area of the aperture 30, the second grating 40 adjusts the exit direction of the received target beam so that the adjusted exit direction matches the exit direction of the first beam. This allows the target beam incident at the second incident area of the aperture 30 to enter the aperture 30 with the exit direction of the first beam. At this time, the aperture 30 is used to transmit the target beam with the adjusted exit direction. Thus, by setting the second grating 40 at the aperture 30 to adjust the exit direction of the obliquely emitted second beam, the adjusted second beam can be utilized through the aperture 30, greatly improving the beam energy utilization rate in the light source system 1.
[0031] In this embodiment, a first grating 20 is provided in the emission direction of the light source 10. The first grating 20 converts the unpolarized initial beam into two beams with the same polarization direction but different emission directions. The emission direction of one of the beams is adjusted by setting a second grating 40, so that the beams with divergence angles within a preset angle range are finally emitted after entering the aperture 30 in the same direction. Thus, the beam energy utilization rate in the light source system 1 is greatly improved when the optical expansion of the light source system 1 remains unchanged or changes only slightly.
[0032] Please refer to Figure 2 , Figure 2 A schematic diagram of a light source system according to another embodiment of this application is shown. The following will be combined with… Figure 2 The light source system provided in the embodiments of this application will be described in detail. For example... Figure 2 As shown, the light source system of this embodiment includes a light source 10, a first grating 20, an aperture 30, and a second grating 40.
[0033] In this embodiment, the light source 10 is used to emit an initial beam, and the initial beam emitted by the light source 10 includes a first polarized light and a second polarized light, wherein both the first polarized light and the second polarized light are circularly polarized light.
[0034] Optionally, the light source system further comprises a collimating lens 50, which is arranged between the light source 10 and the first grating 20, and is configured to collimate the initial light beam and project the collimated initial light beam to the first grating 20. After the collimating lens 50 collimates the initial light beam, the divergence angle of the initial light beam projected to the first grating 20 is reduced, and the collection effect of the initial light beam on the subsequent optical elements is improved, thereby improving the energy utilization of the light source system on the initial light beam emitted by the light source 10.
[0035] In the embodiment, the first grating 20 is arranged in the direction of the initial light beam, and is configured to adjust the polarization direction of the received initial light beam, and emit the first light beam and the second light beam with the same polarization direction. For the first polarized light in the initial light beam incident on the first grating 20 in the first direction, the first grating 20 is configured to transmit the first polarized light incident in the first direction, and emit the first light beam in the first direction to the diaphragm 30, and the polarization direction of the first light beam is the polarization direction of the first polarized light. For the second polarized light in the initial light beam incident on the first grating 20 in the first direction, the first grating 20 is configured to adjust the emission direction and the polarization direction of the second polarized light incident in the first direction, and emit the second light beam in the second direction to the diaphragm 30, and the polarization direction of the adjusted second light beam matches the polarization direction of the first polarized light.
[0036] In some embodiments, the first grating 20 comprises a liquid crystal polarization volume holographic grating, the first polarized light has a first spiral direction, the second polarized light has a second spiral direction, the first spiral direction is opposite to the second spiral direction, and the first spiral direction is the same as the liquid crystal spiral direction of the liquid crystal polarization volume holographic grating. The diffraction angle of the liquid crystal polarization volume holographic grating is determined by the inclination angle of its own refractive index plane, different liquid crystal polarization volume holographic gratings can be selected to achieve different diffraction angle sizes, and the liquid crystal polarization volume holographic grating can be dynamically adjusted under an applied voltage, so that the adjustment of the diffraction angle of the liquid crystal polarization volume holographic grating can be realized by adjusting the size of the applied voltage.
[0037] Specifically, the liquid crystal polarization volume holographic grating is used to transmit first polarized light with the same liquid crystal helical direction as the liquid crystal helical direction of the liquid crystal polarization volume holographic grating, so as to obtain first light beams with a first helical direction and exit in a first direction; the liquid crystal polarization volume holographic grating is also used to adjust the polarization direction of second polarized light with the opposite liquid crystal helical direction, and diffract the second polarized light, so as to obtain second light beams with the first helical direction and exit in a second direction, and the diffraction angle of the second polarized light used to form the second light beams, that is, the included angle between the exit directions of the first light beams and the second light beams of the liquid crystal polarization volume holographic grating. By using the liquid crystal polarization volume holographic grating in the first grating 20, the first polarized light and the second polarized light with different polarization directions in the initial light beams can be converted into polarized light output with the same polarization direction, avoiding the loss of the light beams in the process of obtaining the polarized light, thereby greatly improving the utilization rate of the initial light beams emitted by the light source 10.
[0038] For example, when the liquid crystal helical direction of the first grating 20 is right-handed, if the first polarized light in the initial light beams is right-handed circularly polarized light and the second polarized light is left-handed circularly polarized light: when the right-handed circularly polarized light is incident on the first grating 20 in the first direction, the first grating 20 is used to transmit the right-handed circularly polarized light with the same liquid crystal helical direction as that of the first grating 20, and emit the right-handed circularly polarized light to the light barrier 30 in the first direction; when the left-handed circularly polarized light is incident on the first grating 20 in the first direction, the first grating 20 is used to adjust the polarization direction of the left-handed circularly polarized light with the opposite liquid crystal helical direction, and diffract the left-handed circularly polarized light, so as to emit the left-handed circularly polarized light to the light barrier 30 in the second direction.
[0039] In this embodiment, the light barrier 30 is arranged on the light exit direction of the first grating 20. Since the initial light beams form the first light beams and the second light beams with the same polarization direction after passing through the first grating 20, and the exit directions of the first light beams and the second light beams are different. Based on the optical etendue of the light barrier 30 itself, by arranging the second grating 40 at the light barrier 30 to adjust the exit direction of the second light beams, the adjusted second light beams can be transmitted through the light barrier 30 and utilized, thereby further improving the light beam energy utilization rate of the light source system.
[0040] Specifically, when the light beams with the divergence angle in the preset angle range in the first light beams emitted by the first grating 20 are projected to the first light entry area of the light barrier 30, the light barrier 30 is used to transmit the light beams with the divergence angle in the preset angle range in the first light beams.
[0041] Further, the second light entrance area of the diaphragm 30 is located in the propagation direction of the second light beam when the second light beam is obliquely propagated in the light source system, and the second grating 40 arranged at the second light entrance area of the diaphragm 30 is configured to adjust the exit direction of the target light beam received in the second direction when the target light beam having a divergence angle within a preset angle range in the second light beam is received, so that the adjusted target light beam is incident on the diaphragm 30 in a first direction matching the exit direction of the first light beam, and the diaphragm 30 is configured to transmit the target light beam having the adjusted exit direction in the second light beam, thereby improving the light beam energy utilization of the light source system.
[0042] Optionally, the second grating 40 includes a volume holographic grating, and the incident light beam can be diffracted by the volume holographic grating when the incident light beam satisfies the Bragg condition of the volume holographic grating. In the embodiment of the present application, the target light beam incident on the volume holographic grating in the second direction satisfies the Bragg condition of the volume holographic grating, so that the target light beam can be diffracted by the volume holographic grating when passing through the volume holographic grating. The diffraction angle of the second grating 40 matches the diffraction angle of the first grating 20, that is, the second polarized light in the initial light beam incident on the first grating 20 in the first direction is diffracted by the first grating 20 to form the second light beam exiting in the second direction, and the second light beam incident on the second grating 40 in the second direction is diffracted by the second grating 40 to exit in the first direction again, so that the diffracted second light beam can be transmitted through the diaphragm 30 and utilized again. In the process of converting the non-polarized initial light beam exiting from the light source 10 into a polarized light beam, the first grating 20 and the second grating 40 in the optical path have a very high diffraction efficiency for the received light beam and a very small light beam loss, thereby effectively improving the light beam energy utilization in the light source system, and the first grating 20 and the second grating 40 are flat panel optical elements, so that the overall volume of the light source system is relatively small.
[0043] In the embodiment, the relative distance between the first grating 20 and the second grating 40 is a set distance D:
[0044] D=A / B*d;
[0045] Wherein, A is the included angle between the line connecting the center of the first grating 20 and the center of the diaphragm 30 and the optical axis of the diaphragm 30, B is the included angle between the exit directions of the first light beam and the second light beam, and d is the spot radius of the initial light beam projected to the first grating 20.
[0046] For example, if the light source 10 is a square Lambert non-polarized light source with a side length of 1 mm, and the diaphragm 30 receives the light beam having an energy in the exit direction of the light source 10 and having a divergence angle within ±80°, the light beam energy utilization of the light source system is about 96.5%. In the traditional scheme, in order to obtain a polarized light beam, a polarizer is arranged in the light exit direction of the light source 10, and the polarizer will cause a loss of polarized light opposite to the polarization direction, so that the light beam energy utilization of the light source system is only about 48.3%.
[0047] In the embodiment, if the diffraction angle of the first grating 20 is 40°, and the initial light beam propagating in the forward direction (the direction of the outgoing light is parallel to the optical axis of the first grating 20) forms a first light beam propagating in the forward direction and a second light beam with a propagation direction of 40° to the optical axis of the first grating 20 after passing through the first grating 20, and the first light beam (50% of the initial light beam) and the second light beam (50% of the initial light beam) have the same polarization direction.
[0048] Optionally, the first light inlet area of the diaphragm 30 is used to transmit the light beam with a divergence angle within ±40° in the forward direction in the first light beam. Since the light intensity of the light beam emitted by the light source 10 presents a cosine distribution, that is, the energy of the light beam in the region with a smaller divergence angle is higher, and the energy of the light beam at a large divergence angle is much smaller than that of the light beam at a small divergence angle. At this time, the light beam passing through the first light inlet area of the diaphragm 30 and transmitted by the diaphragm 30 is about 70% of the first light beam (50% of the initial light beam), that is, the energy of the light beam at the first light inlet area is about 35% of the energy of the initial light beam. The second light beam propagating obliquely is propagated in the forward direction after being diffracted by 40° by the second grating 40 at the second light inlet area of the diaphragm 30. At this time, the light beam passing through the second light inlet area of the diaphragm 30 and transmitted by the diaphragm 30 is about 70% of the second light beam (50% of the initial light beam), that is, the energy of the light beam at the second light inlet area is about 35% of the energy of the initial light beam. In this way, compared with the conventional scheme using a polarizer, the energy utilization rate of the light source system as a whole in the embodiment of the present application reaches 70%, which greatly improves the light beam energy utilization rate in the light source system under the condition that the optical etendue of the light source system is unchanged or changes little.
[0049] In the embodiment, in the process of converting the non-polarized initial light beam emitted by the light source 10 into a polarized light beam, the first grating 20 and the second grating 40 are arranged in the optical path of the light source system to diffract the received light beam, so that the non-polarized initial light beam is converted into two light beams with the same polarization direction and different outgoing directions. Then, the outgoing direction of one of the two light beams is adjusted by the second grating 40, so that the light beams with a divergence angle within a preset angle range in the two light beams finally enter the diaphragm 30 in the same direction. Under the condition that the optical etendue of the light source system is unchanged or changes little, the light beam loss in the polarization conversion process is greatly reduced, the light beam energy utilization rate in the light source system is effectively improved, and the first grating 20 and the second grating 40 are plate-type optical elements, so that the overall volume of the light source system is relatively small.
[0050] Please refer to Figure 3 , Figure 3 The structure schematic diagram of the projection device 2 provided by an embodiment of the present application is shown. The following will be described in combination withFigure 3 The projection device 2 provided by the embodiment of the present application is described in detail. As shown in the figure, the projection device 2 of the embodiment comprises a housing 2 and the light source system 1 as described in the above embodiment. Figure 3
[0051] Optionally, the light source system 1 is arranged in the housing 2, and the light source system 1 is used to emit a polarized light beam. The projection device 2 further comprises at least a display chip, which is a passive light-emitting display chip, including but not limited to a Liquid Crystal Display (LCD) chip and a Liquid Crystal on Silicon (LCOS) chip. When the display chip is used as a polarization modulation device, it needs to work under the condition of polarized light. Therefore, after the display chip is illuminated by the light source system 1 used to emit a polarized light beam, the display chip forms a to-be-displayed image based on the received polarized light beam and emits the to-be-displayed image. In the light source system 1, a light-emitting diode can be used as the light source 10 to provide a non-polarized white light beam, so as to improve the purity of the projected image and reduce the manufacturing cost of the projection device 2.
[0052] In the embodiment, by using the light source system 1 provided by the above embodiment, the light beam energy utilization rate of the projection device 2 is greatly improved under the condition that the optical etendue of each optical component in the projection device 2 is unchanged or changes little, and the setting of the light source system 1 improves the purity of the projected image and reduces the manufacturing cost of the projection device 2.
[0053] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, but not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part of the technical features; and these modifications or replacements do not drive the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present application.
Claims
1. A light source system, characterized by, The light source system comprises: a light source for emitting an initial light beam; a first grating arranged in the emission direction of the initial light beam, the first grating being configured to adjust the polarization direction of the received initial light beam and emit a first light beam and a second light beam having the same polarization direction, the emission directions of the first light beam and the second light beam being different; a diaphragm arranged in the light emission direction of the first grating, the diaphragm comprising a first light entry region and a second light entry region provided with a second grating, the diaphragm being configured to transmit a light beam incident on the diaphragm in the emission direction of the first light beam, wherein the light beam in the first light beam having a divergence angle within a preset angle range is projected to the first light entry region, and a target light beam in the second light beam having a divergence angle within the preset angle range is projected to the second grating; the second grating being configured to adjust the emission direction of the received target light beam so that the adjusted target light beam is incident on the diaphragm in the emission direction of the first light beam.
2. The light source system of claim 1, wherein The initial light beam comprises first polarized light and second polarized light; the first grating being configured to transmit the first polarized light incident in a first direction and emit the first light beam in the first direction to the diaphragm; the first grating being configured to adjust the emission direction and polarization direction of the second polarized light incident in the first direction and emit the second light beam in a second direction to the diaphragm.
3. The light source system of claim 2, wherein The first grating comprises a liquid crystal polarization volume holographic grating, the first polarized light has a first spiral direction, the second polarized light has a second spiral direction, the first spiral direction is opposite to the second spiral direction, and the first spiral direction is the same as the liquid crystal spiral direction of the liquid crystal polarization volume holographic grating; the liquid crystal polarization volume holographic grating is configured to transmit the first polarized light having the same liquid crystal spiral direction as the liquid crystal polarization volume holographic grating to emit the first light beam having the first spiral direction; the liquid crystal polarization volume holographic grating is configured to adjust the polarization direction of the second polarized light having the opposite liquid crystal spiral direction and diffract the second polarized light to emit the second light beam having the first spiral direction in the second direction.
4. The light source system of claim 2, wherein The second grating is configured to adjust the emission direction of the received target light beam incident in the second direction so that the adjusted target light beam is incident on the diaphragm in the first direction.
5. The light source system of claim 4, wherein, The second grating comprises a volume holographic grating, and the target light beam incident in the second direction satisfies the Bragg condition of the volume holographic grating.
6. The light source system according to any one of claims 1 to 5, characterized in that, The relative distance between the first grating and the second grating is a set distance D: D = A / B*d; wherein A is the included angle between the line connecting the center of the first grating and the center of the diaphragm and the optical axis of the diaphragm, B is the included angle between the emission directions of the first light beam and the second light beam, and d is the spot radius of the initial light beam projected to the first grating.
7. The light source system according to any one of claims 1 to 5, characterized in that, The light source system further comprises a collimating lens arranged between the light source and the first grating, the collimating lens being configured to collimate the initial light beam and project the collimated initial light beam to the first grating.
8. A projection apparatus, characterized by comprising: The projection device comprises a housing and the light source system as claimed in any one of claims 1 to 7, the light source system being arranged in the housing.