A projection system and head-mounted device

Abstract

The present application discloses a projection system and a head-mounted device. The projection system includes: a light source assembly, a polarization element, a beam adjustment module and a reflective component; the beam adjustment module has an optical axis, and the light source assembly is located on a first side of the optical axis; the light emitted by the light source assembly is transmitted to the beam adjustment module through the polarization element and is shaped, and at least the central light of the light is incident on the beam adjustment module from the first side of the optical axis; the light incident on the beam adjustment module is reflected by the reflective component to the beam adjustment module and is imaged, and at least the central light of the reflected light is emitted from the second side of the optical axis, and then is reflected by the polarization element and output.

Description

Technical Field

[0001] The present application relates to the technical field of optical devices, and more specifically, to a projection system and a head-mounted device. Background Art

[0002] With the advancement of imaging technology, people's demand for immersive experience is getting higher and higher. The development of VR / AR technology in recent years has gradually met people's pursuit of visual experience. Head-mounted devices can free people's hands, reduce dependence on screens, and create better visual effects.

[0003] The architecture of the traditional LCOS AR optical machine includes an illumination part and an imaging part. The illumination part includes a collimating component and a shaping component. The illumination part collimates and shapes the light emitted by the light source so that the light spot matches the LCOS chip. The function of the imaging part is to propagate the image on the LCOS chip into the waveguide. In the traditional LCOS AR optical machine, a separate shaping component is required to shape the light, and a separate imaging component is required for the final imaging, which directly leads to the inability to further reduce the size of the projection system. Summary of the invention

[0004] One purpose of the present application is to provide a new technical solution for a projection system and a head-mounted device.

[0005] According to a first aspect of an embodiment of the present application, a projection system is provided. The projection system comprises: a light source assembly, a polarization element, a beam adjustment module and a reflection component;

[0006] The beam adjustment module has an optical axis, and the light source assembly is located on a first side of the optical axis;

[0007] The light emitted by the light source assembly is transmitted to the light beam adjustment module through the polarization element, and at least the central light of the light is incident on the light beam adjustment module from the first side of the optical axis to be shaped;

[0008] The light incident on the beam adjustment module is reflected back to the beam adjustment module by the reflective component, and at least the central light of the reflected light is emitted from the second side of the optical axis and formed into an image, and then is reflected by the polarization element and output.

[0009] Optionally, the light beam adjustment module includes a lens assembly, which shapes the light incident to the light beam adjustment module and images the light reflected to the light beam adjustment module.

[0010] Optionally, the beam adjustment module further includes a first phase delay plate, and the first phase delay plate is located between the polarization element and the reflective component.

[0011] Optionally, the beam adjustment module further includes a brightness adjuster, and the brightness adjuster is located between the polarization element and the reflective component.

[0012] Optionally, the beam adjustment module comprises a lens assembly, a first phase delay plate and a brightness adjuster, and the first phase delay plate, the lens assembly and the brightness adjuster are arranged between the polarization element and the reflective component.

[0013] Optionally, the brightness adjuster comprises a second phase delay plate and a third phase delay plate, the second phase delay plate is fixedly arranged, and the third phase delay plate is movable;

[0014] The second phase retarder has a first fast axis, the third phase retarder has a second fast axis, and the third phase retarder rotates relative to the second phase retarder to adjust the angle between the first fast axis and the second fast axis.

[0015] Optionally, the light source assembly includes a light source and a reflective bowl. After the light emitted by the light source is reflected by the reflective bowl, the light is transmitted parallel to the optical axis and then transmitted to the beam adjustment module through the polarization element.

[0016] Optionally, the projection system further comprises an optical waveguide plate, the optical waveguide plate comprising an incoupling region and an outcoupling region; the light reflected by the polarization element is transmitted to the incoupling region, and then transmitted to the outcoupling region through the optical waveguide plate, and finally the light is output through the outcoupling region.

[0017] According to a second aspect of the embodiments of the present application, a head mounted device is provided, wherein the head mounted device comprises the projection system as described in the first aspect.

[0018] In an embodiment of the present application, a projection system is provided, which achieves the purpose of reducing the size of the projection system.

[0019] Other features and advantages of the present application will become apparent from the following detailed description of exemplary embodiments of the present application with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings, which constitute a part of the specification, illustrate embodiments of the present application and, together with the description, serve to explain the principles of the present application.

[0021] Figure 1 Shown is a schematic structural diagram of the projection system of the present application.

[0022] Figure 2 Shown is the optical path structure diagram of the projection system of the present application.

[0023] Figure 3 Shown is a schematic structural diagram of the light source assembly.

[0024] Description of reference numerals:

[0025] 1. Light source assembly; 11. Light source; 12. Reflection bowl; 2. Polarization element; 3. Beam adjustment module; 31. First phase delay plate; 32. Lens assembly; 321. First lens; 322. Second lens; 323. Third lens; 324. Fourth lens; 33. Brightness adjuster; 331. Second phase delay plate; 332. Third phase delay plate; 4. Reflection component; 5. Optical waveguide plate; 51. Incoupling region; 52. Outcoupling region; 6. Human eye. DETAILED DESCRIPTION

[0026] Various exemplary embodiments of the present application will now be described in detail with reference to the accompanying drawings. It should be noted that unless otherwise specifically stated, the relative arrangement of components and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present application.

[0027] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the present application, its application, or uses.

[0028] Techniques and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the techniques and equipment should be considered part of the specification.

[0029] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0030] It should be noted that like reference numerals and letters refer to similar items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0031] The existing AR optical machine architecture includes an illumination part and an imaging part, wherein the illumination part includes a shaping component that shapes the light emitted by the light source, and the imaging part includes an imaging component that realizes image formation. Therefore, in the existing AR optical machine architecture, a separate shaping component and a separate imaging component are required to process the light accordingly. After such a setting, the volume of the existing AR optical machine architecture cannot be further reduced.

[0032] Based on the above technical problems, the present application provides a projection system. Figure 1-Figure 3As shown, the projection system includes: a light source assembly 1, a polarizing element 2, a beam adjustment module 3 and a reflective component 4. The beam adjustment module 3 has an optical axis, and the light source assembly 1 is located on a first side of the optical axis. The light emitted by the light source assembly 1 is transmitted to the beam adjustment module 3 through the polarizing element 2, and at least the central light of the light is incident on the beam adjustment module 3 from the first side of the optical axis to be shaped. The light incident on the beam adjustment module 3 is reflected back to the beam adjustment module 3 by the reflective component 4, and at least the central light of the reflected light is emitted from the second side of the optical axis and imaged, and then reflected by the polarizing element 2 and output.

[0033] In this embodiment, Figure 1 Shown is a schematic diagram of the structure of the projection system. Figure 2 The figure shows the light schematic diagram of the projection system. Figure 2 The thick black line in the middle shows the light transmission path diagram. Figure 2 The dotted line indicates the optical axis of the beam adjustment module 3 .

[0034] Reference Figure 1 and Figure 2 As shown, the light emitted by the light source assembly 1 is transmitted through the polarization element 2 to the beam adjustment module 3, and the beam adjustment module 3 performs shaping processing on the incident light; the shaped light is reflected by the reflection component 4, and the reflected light carries the image information, so that the shaped light returns to the beam adjustment module 3 for transmission and emission. Therefore, in this embodiment, no shaping component is separately provided in the light source assembly 1, but the same set of beam adjustment modules 3 is used for the components for light shaping and the components for image formation (that is, the beam adjustment module 3 has both light shaping and image formation functions), which reduces the volume of the projection system.

[0035] Specifically, this embodiment limits the setting position of the light source assembly 1, that is, the light source assembly 1 is offset relative to the optical axis of the light beam adjustment module 3, so that the light emitted by the light source assembly 1 is not straight in and out, but at least the center light of the incident light is incident from the first side of the light beam adjustment module 3, and at least the center light of the reflected light is emitted from the second side of the light beam adjustment module 3, wherein the first side and the second side are located on different sides of the optical axis.

[0036] In the prior art, the incident light enters the beam adjustment module 3 along the direction of the optical axis. If the incident light enters the beam adjustment module 3 along the direction of the optical axis, the incident light is incident along the direction of the optical axis, and after being reflected by the reflective component 4, the reflected light is also emitted along the direction of the optical axis. The incident light and the reflected light are overlapped, so the beam adjustment module 3 can only play a role in imaging the image, but cannot achieve the effect of shaping the light.

[0037] In the embodiment of the present application, the light source assembly 1 is offset relative to the optical axis of the light beam adjustment module 3 so that at least the central light beam in the incident light beam and at least the central light beam in the reflected light beam are not transmitted overlappingly. In this way, the incident light beam is transmitted off-axis relative to the optical axis. The incident light beam can be shaped by means of the first side of the light beam adjustment module 3, and the reflected light beam is transmitted on the second side of the light beam adjustment module 3. The second side of the light beam adjustment module 3 can image the light beam carrying image information.

[0038] Therefore, in the embodiment of the present application, the setting position of the light source assembly 1 is limited so that the shaping of the light and the imaging of the light share a set of light beam adjustment modules 3, avoiding the need to set a separate shaping component in the light source assembly 1 to shape the light beam, thereby reducing the volume of the projection system.

[0039] In this embodiment, the projection system includes a polarizing element 2, and the polarizing element 2 is arranged on the transmission optical path of the light. For example, the polarizing element 2 can be a polarizing reflector. The polarizing reflector can selectively reflect or transmit the light, for example, the polarizing reflector reflects the S light and transmits the P light. Specifically, the light emitted by the light source assembly 1 is natural light, which contains 50% of the P light and 50% of the S light. The polarizing reflector can reflect the S light in the light emitted by the light source assembly 1, and only retain the P light, so that the P light is transmitted by the polarizing reflector, shaped in the light beam adjustment module 3, and can continue to propagate in the projection system. And the polarizing reflector is arranged between the light source assembly 1 and the light beam adjustment module 3, and the light emitted from the second side of the light beam adjustment module 3 is reflected by the polarizing reflector, and then the reflected light is output, and the output light is received by the human eye 6.

[0040] In this embodiment, the reflective component 4 reflects the light. For example, the reflective component 4 may be a light valve component. For example, the light valve component is a polarization splitting component. For example, the light valve component includes but is not limited to an LCOS display screen, and may also be an LCD display screen.

[0041] It should be noted that the optical axis is the central axis of the beam adjustment module 3 .

[0042] In an alternative embodiment, referring to Figure 2 As shown, there is an angle between the light incident from the first side of the optical axis and the optical axis, and the angle ranges from 10° to 15°.

[0043] In this embodiment, the light is incident from the first side of the optical axis, that is, the light is incident from the first side of the beam adjustment module 3. There is an angle between the light incident from the first side of the beam adjustment module 3 and the optical axis of the beam adjustment module 3, and the angle range is 10° to 15°.

[0044] Specifically, the light source assembly 1 is offset relative to the optical axis, so the light emitted by the light source assembly 1 does not vertically impinge on the reflective component 4 (LCOS chip), but at a certain angle of about 10° to 15°. This embodiment limits the angle between the light incident from the first side of the beam adjustment module 3 and the optical axis of the beam adjustment module 3, so that the first side of the beam adjustment module 3 can shape the incident light. If the angle is too large or too small, the first side of the beam adjustment module 3 will affect the shaping effect of the incident light, that is, if the angle is too large or too small, the incident light cannot be shaped according to the structure of the first side of the beam adjustment module 3 (specifically, the lens structure).

[0045] Specifically, the light incident on the reflective component 4 (LCOS chip) is P light (because the light emitted by the light source component 1 passes through the polarization element 2 for the first time and transmits the P light), and the light generated by the reflective component 4 (LCOS chip) is modulated to generate the image as S light. The polarization element 2 will output the S light generated by the reflective component 4 (LCOS chip).

[0046] The light reflected by the reflective component 4 (LCOS chip) also has the same angle. After the reflected light is imaged by the beam adjustment module 3, it will reach the polarization element 2; if the angle between the light incident from the first side of the beam adjustment module 3 and the optical axis of the beam adjustment module 3 is too large or too small, the angle between the reflected light and the optical axis will also be too small or too large. If the angle is too small or too large, the reflected light cannot accurately reach the polarization element 2.

[0047] In one embodiment, referring to Figure 1 and Figure 2 As shown, the light beam adjustment module 3 includes a lens assembly 32 , and the lens assembly 32 shapes the light incident to the light beam adjustment module 3 , and the lens assembly 32 images the light reflected to the light beam adjustment module 3 .

[0048] In this embodiment, the beam adjustment module 3 includes a lens assembly 32 (i.e., a lens module), wherein the lens assembly 32 has two functions: one is to shape the light emitted by the light source assembly 1, and to shape the circular light spot emitted by the light source assembly 1 into a rectangular light spot to adapt to the effective area of ​​the reflective component 4 (LCOS chip); the other is to complete the imaging effect and clearly transmit the image generated on the reflective component 4 (LCOS chip).

[0049] Specifically, the light source assembly 1 is offset relative to the optical axis of the lens assembly 32. The light emitted by the light source assembly 1 is transmitted through the polarization element 2 and then incident on the first side of the lens assembly 32. The first side of the lens assembly 32 shapes the light emitted by the light source assembly 1. The shaped light is reflected by the reflective component 4, and the reflected light is transmitted through the second side of the lens assembly 32, so that the image generated on the reflective component 4 (LCOS chip) is clearly transmitted.

[0050] In an alternative embodiment, referring to Figure 1 and Figure 2 As shown, the lens assembly 32 includes a first lens 321, a second lens 322, a third lens 323 and a fourth lens 324 which are sequentially arranged along the optical axis, and the fourth lens 324 is arranged close to the reflective component 4. In this embodiment, four lenses are arranged to shape the light and clearly transmit the image generated on the reflective component 4 (LCOS chip), thereby reducing the volume of the projection system.

[0051] In an optional embodiment, along the optical axis direction, the first surface of the first lens 321 is a convex surface, the second surface of the first lens 321 is a plane, and the optical power of the first lens 321 is positive; the first surface of the second lens 322 is a convex surface, the second surface of the second lens 322 is a plane, and the optical power of the second lens 322 is positive; the first surface of the third lens 323 is a plane, the second surface of the third lens 323 is a convex surface, and the optical power of the third lens 323 is positive; the first surface of the fourth lens 324 is a convex surface, the second surface of the fourth lens 324 is a convex surface, and the optical power of the fourth lens 324 is positive. The second surfaces of the above lenses are all surfaces close to the reflecting component 4.

[0052] In this embodiment, the first lens 321, the second lens 322 and the third lens 323 are convex cylindrical lenses, specifically, the first lens 321, the second lens 322 and the third lens 323 are shaping convex cylindrical lenses. The fourth lens 324 is a biconvex lens, which is mainly used to converge the light after shaping, and in the imaging process, the biconvex lens and other lenses transmit the image.

[0053] In an optional embodiment, the focal length range of the first lens 321 is: 7mm-10mm; the focal length range of the second lens 322 is: -9mm to -6mm; the focal length range of the third lens 323 is: 3mm-5mm; the focal length range of the fourth lens 324 is: 6mm-8mm.

[0054] In this embodiment, the focal length ranges of the first lens 321, the second lens 322, the third lens 323 and the fourth lens 324 are limited so that the light incident to the lens assembly 32 forms uniform light and the incident light is shaped; and the focal length ranges of the first lens 321, the second lens 322, the third lens 323 and the fourth lens 324 are limited so that the image generated on the reflective component 4 (LCOS chip) is clearly transmitted.

[0055] In a specific embodiment, the lens parameters of the first lens 321 , the second lens 322 , the third lens 323 and the fourth lens 324 may refer to Table 1 to Table 3.

[0056] Table 1:

[0057]

[0058] Table 2:

[0059]

[0060] Table 3:

[0061]

[0062] In this embodiment, the surface structures of the first lens 321, the second lens 322, the third lens 323 and the fourth lens 324 are limited so that the light incident to the lens assembly 32 forms uniform light and the incident light is shaped; and the surface structures of the first lens 321, the second lens 322, the third lens 323 and the fourth lens 324 are limited so that the image generated on the reflective component 4 (LCOS chip) is clearly transmitted.

[0063] In one embodiment, referring to Figure 1 and Figure 2 As shown, the beam adjustment module 3 further includes a first phase delay plate 31 , and the first phase delay plate 31 is located between the polarization element 2 and the reflective component 4 .

[0064] In this embodiment, a first phase retarder 31 is arranged between the polarizing element 2 and the reflecting component 4. For example, the first phase retarder 31 may be a quarter wave plate. The first phase retarder 31 is arranged between the polarizing element 2 and the reflecting component 4 to improve the contrast of the projection system.

[0065] Specifically, the reflective component 4 (LCOS chip) acts as an image source. The reflective component 4 (LCOS chip) converts the incident P light into S light through phase modulation. However, due to the differences in the production processes of different reflective components 4 (LCOS chips), the P light cannot be converted into S light 100%, which will cause the brightness of the dark field of the picture to increase and the contrast to decrease.

[0066] In order to improve the contrast of the projection system, a first phase retarder 31 is arranged between the polarization element 2 and the reflective component 4. By fine-tuning the angle between the fast axis (the direction of the light vector with a slow propagation speed in the phase retarder is called the slow axis. The direction of the light vector with a fast propagation speed in the phase retarder is called the fast axis) of the first phase retarder 31 and the P light, the P light can be modulated in advance to ensure that the modulated P light will become 100% S light after reflection by the reflective component 4 (LCOS chip), so as to improve the optical-mechanical contrast.

[0067] In a specific embodiment, the beam adjustment module 3 includes a lens assembly 32 and a first phase delay plate 31, and the first phase delay plate 31 can be located between the lens assembly 32 and the polarization element 2, or the first phase delay plate 31 can be located between the lens assembly 32 and the reflective component 4. This embodiment does not specifically limit the first phase delay plate 31 and the lens assembly 32, as long as the two are arranged along the optical axis of the beam adjustment module 3 (i.e., the optical axis of the lens assembly 32).

[0068] In one embodiment, referring to Figure 1 and Figure 2 As shown, the beam adjustment module 3 further includes a brightness adjuster 33 , and the brightness adjuster 33 is located between the polarization element 2 and the reflective component 4 .

[0069] In this embodiment, the beam adjustment module 3 also includes a brightness adjuster 33. The projection system detects the brightness of the external ambient light in real time. When located in a bright outdoor environment, the brightness adjuster 33 adjusts the brightness to maximize the eye-level brightness. When located in a dark indoor environment or at night, the brightness adjuster 33 adjusts the brightness to appropriately reduce the eye-level brightness, thereby improving the comfort of the projection system.

[0070] In a specific embodiment, the beam adjustment module 3 includes a lens assembly 32 and a brightness adjuster 33. The brightness adjuster 33 may be located between the lens assembly 32 and the polarization element 2, or the brightness adjuster 33 may be located between the lens assembly 32 and the reflective component 4. This embodiment does not specifically limit the brightness adjuster 33 and the lens assembly 32, as long as the two are arranged along the optical axis of the beam adjustment module 3 (i.e., the optical axis of the lens assembly 32).

[0071] In one embodiment, the beam adjustment module 3 includes a lens assembly 32, a first phase delay plate 31 and a brightness adjuster 33. Along the optical axis direction, the first phase delay plate 31, the lens assembly 32 and the brightness adjuster 33 are arranged between the polarization element 2 and the reflective component 4.

[0072] In this embodiment, the beam adjustment module 3 includes a first phase delay plate 31, a brightness adjuster 33, and a lens assembly 32, wherein the first phase delay plate 31, the brightness adjuster 33, and the lens assembly 32 are arranged along the optical axis of the lens assembly 32, and the position order of the three can be interchanged, and it is not necessary to Figure 1 and Figure 2 Arranged in the order shown.

[0073] In one embodiment, referring to Figure 1 and Figure 2 As shown, the brightness adjuster 33 includes a second phase delay plate 331 and a third phase delay plate 332, the second phase delay plate 331 is fixedly arranged, and the third phase delay plate 332 is movable;

[0074] The second phase retarder 331 has a first fast axis, the third phase retarder 332 has a second fast axis, and the third phase retarder 332 rotates relative to the second phase retarder 331 to adjust the angle between the first fast axis and the second fast axis.

[0075] In this embodiment, the brightness adjuster 33 is composed of two circular phase retarders, each of which has a fast axis. Among the two phase retarders, one phase retarder is fixed and the other phase retarder can rotate around the center of the circle. When the other phase retarder rotates so that the fast axes of the two phase retarders coincide, all light can pass through. When the other phase retarder rotates so that the fast axes of the two phase retarders are 90° perpendicular, all light cannot pass through.

[0076] Therefore, the brightness of the light is adjusted by the angle between the fast axes of the two phase delay plates. Specifically, the projection system detects the brightness of the external environment in real time. When it is located in a bright outdoor environment, the fast axes of the two phase delay plates coincide, making the eye brightness the highest; when it is located in a dark environment indoors or at night, one of the phase delay plates rotates around the center of the circle, so that the fast axes of the two phase delay plates have a certain angle, which is less than 90°, appropriately reducing the eye brightness and improving the comfort of the AR machine.

[0077] In one embodiment, referring to Figure 1 and Figure 3As shown, the light source assembly 1 includes a light source 11 and a reflective bowl 12 . After the light emitted by the light source 11 is reflected by the reflective bowl 12 , the light is transmitted parallel to the optical axis and then transmitted to the beam adjustment module 3 through the polarization element 2 .

[0078] Specifically, the light source 11 includes three light sources 11, wherein the three light sources 11 include a first light source 11, a second light source 11 and a third light source 11, wherein the first light source 11, the second light source 11 and the third light source 11 are all LED light sources, emitting red, green and blue light respectively. The light source 11 emits light, and the light source 11 itself has a large light-emitting angle, so a collimating device is required to narrow the light angle. In this embodiment, a CPC (compound parabolic concentrator) reflective bowl 12 is arranged above the light source 11.

[0079] When the reflective bowl 12 is arranged on the light source 11, the large-angle light emitted by the LED light source will irradiate the inner wall of the reflective bowl 12, and after being reflected by the reflective bowl 12, it will propagate vertically downward, thereby achieving the effect of light collimation.

[0080] In one embodiment, the projection system further includes a light waveguide plate 5, which includes an in-coupling area 51 and an out-coupling area 52; the light reflected by the polarization element 2 is transmitted to the in-coupling area 51, and then transmitted to the out-coupling area 52 through the light waveguide plate 5, and finally the light is output through the out-coupling area 52.

[0081] In this embodiment, the light reflected by the polarization element 2 is not directly transmitted to the human eye 6 , but an optical waveguide plate 5 is arranged on the transmission optical path of the light, and the light reflected by the polarization element 2 is transmitted to the human eye 6 after passing through the output of the optical waveguide plate 5 .

[0082] According to a second aspect of the embodiment of the present application, a head mounted device is provided. The head mounted device includes the projection system as described in the first aspect. For example, the head mounted device is an AR head mounted device. For example, the head mounted device is an AR optical machine.

[0083] The above embodiments focus on the differences between the various embodiments. As long as the different optimization features between the various embodiments are not contradictory, they can be combined to form a better embodiment. Considering the simplicity of the text, they will not be repeated here.

[0084] Although some specific embodiments of the present application have been described in detail by way of example, it should be understood by those skilled in the art that the above examples are only for illustration, not for limiting the scope of the present application. It should be understood by those skilled in the art that the above embodiments may be modified without departing from the scope and spirit of the present application. The scope of the present application is defined by the appended claims.

Claims

1. A projection system, characterized in that: include: A light source assembly (1), a polarization element (2), a light beam adjustment module (3) and a reflection component (4); The light beam adjustment module (3) has an optical axis, the light source assembly (1) is located on a first side of the optical axis, and the light beam adjustment module (3) comprises a lens assembly (32). The light emitted by the light source assembly (1) is transmitted to the lens assembly (32) through the polarizing element (2), and at least the central light of the light is incident on the lens assembly from the first side of the optical axis to be shaped; The light incident on the lens assembly (32) is reflected by the reflective component (4) back to the lens assembly (32), and at least the central light of the reflected light is emitted from the second side of the optical axis and forms an image, and then is reflected by the polarizing element (2) and output; The lens assembly (32) comprises a first lens (321), a second lens (322), a third lens (323) and a fourth lens (324) which are arranged in sequence along the optical axis. The lens assembly (32) is used to shape the light incident on the light beam adjustment module (3) and to image the light reflected to the light beam adjustment module (3).

2. The projection system according to claim 1, characterized in that: The light beam adjustment module (3) further comprises a first phase delay plate (31), wherein the first phase delay plate (31) is located between the polarization element (2) and the reflection component (4).

3. The projection system according to claim 1, characterized in that: The light beam adjustment module (3) further comprises a brightness adjuster (33), wherein the brightness adjuster (33) is located between the polarization element (2) and the reflection component (4).

4. The projection system according to claim 1, characterized in that: The light beam adjustment module (3) comprises a lens assembly (32), a first phase delay plate (31) and a brightness adjuster (33); the first phase delay plate (31), the lens assembly (32) and the brightness adjuster (33) are arranged between the polarization element (2) and the reflective component (4).

5. The projection system according to claim 4, characterized in that: The brightness adjuster (33) comprises a second phase delay plate (331) and a third phase delay plate (332), wherein the second phase delay plate (331) is fixedly arranged and the third phase delay plate (332) is movably arranged; The second phase retarder (331) has a first fast axis, the third phase retarder (332) has a second fast axis, and the third phase retarder (332) rotates relative to the second phase retarder (331) to adjust the angle between the first fast axis and the second fast axis.

6. The projection system according to claim 1, characterized in that: The light source assembly (1) comprises a light source (11) and a reflection bowl (12); after the light emitted by the light source (11) is reflected by the reflection bowl (12), the light is transmitted parallel to the optical axis and then transmitted through the polarization element (2) to the light beam adjustment module (3).

7. The projection system according to claim 1, characterized in that: The projection system further comprises an optical waveguide plate (5), wherein the optical waveguide plate (5) comprises an incoupling region (51) and an outcoupling region (52); the light reflected by the polarization element (2) is transmitted to the incoupling region (51), and then transmitted to the outcoupling region (52) through the optical waveguide plate (5), and finally the light is output through the outcoupling region (52).

8. A head mounted device, characterized in that: The head mounted device comprises the projection system as described in any one of claims 1-7.

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