Projection device and projection equipment

Abstract

The utility model discloses a projection device and projection equipment, the projection device comprises an illumination module, an optical waveguide module, a light guide module and a light modulator, and the illumination module is used for generating illumination light with a polarization state being a first linear polarization state. The optical waveguide module comprises an optical waveguide and a coupling-in grating, and the coupling-in grating is arranged on the optical waveguide and located on an optical path where the illumination light is located. The light guiding module and the light modulator are arranged on the second side of the optical waveguide, the light guiding module is used for guiding the illumination light to the light modulator, and the light guiding module is used for generating image light with the polarization state being a second linear polarization state. The light guide module and the coupling-in grating are further arranged on a light path where the image light is located, and the light guide module is further used for guiding the image light to the coupling-in grating; the coupling-in grating is also used for deflecting the propagation direction of the light in the second linear polarization state. The light guide module realizes multiplexing of an illumination light path corresponding to the illumination light and an imaging light path corresponding to the image light, and the overall size of the projection device can be reduced.

Description

Technical Field

[0001] The present application relates to the field of optical imaging technology, and more specifically, to a projection device and a projection equipment. Background Art

[0002] With the rapid development of augmented reality (AR) technology, head-mounted AR devices (e.g., smart glasses) have become a hot research and development target. In AR devices, the optical-mechanical system is one of the key components of AR devices.

[0003] The optical-mechanical system may generally include a display chip and an optical coupler, wherein the display chip is used to generate image light carrying image information, and the optical coupler is used to couple the image light into the user's eyes so that the user can see the image information generated by the AR device.

[0004] In related technologies, display chips typically use non-self-luminous display chips, such as Liquid Crystal on Silicon (LCoS) chips. Therefore, AR devices require additional lighting modules to provide illumination. Consequently, the illumination light path and imaging light path occupy a significant portion of the AR device's space, increasing the overall size of the AR device and reducing its wearing comfort. Utility Model Content

[0005] Embodiments of the present application provide a projection device and a projection equipment.

[0006] According to the first aspect of the present application, an embodiment of the present application provides a projection device, which includes an illumination module, an optical waveguide module, a light guiding module and an optical modulator. The illumination module is used to generate an illumination light with a polarization state of a first linear polarization state. The optical waveguide module includes an optical waveguide and an in-coupling grating, the optical waveguide having a first side and a second side opposite to each other, and the illumination light is incident on the optical waveguide via the first side of the optical waveguide; the in-coupling grating is arranged on the optical waveguide and is located on the optical path where the illumination light is located, and is used to transmit the light with the first linear polarization state. The light guiding module is arranged on the second side of the optical waveguide, and is used to guide the illumination light transmitted through the in-coupling grating and the optical waveguide to the optical modulator. The optical modulator is arranged on the second side of the optical waveguide, and is used to modulate the illumination light to generate image light with a polarization state of a second linear polarization state; the second linear polarization state is orthogonal to the first linear polarization state. The light guiding module and the coupling grating are also arranged on the optical path where the image light is located. The light guiding module is also used to guide the image light to the coupling grating; the coupling grating is also used to deflect the propagation direction of the light in the second linear polarization state so that the image light propagates in the optical waveguide.

[0007] In some possible embodiments, the lighting module is disposed on the first side of the optical waveguide.

[0008] In some possible embodiments, the light guiding module includes a polarization beam splitter, which is arranged on the second side of the optical waveguide, and the polarization beam splitter and the light modulator are arranged opposite to each other; the polarization beam splitter is arranged on the optical path where the illumination light and the image light are located, and is used to guide the illumination light to the light modulator and guide the image light to the optical waveguide.

[0009] In some possible embodiments, the light guiding module includes a first polarization unit and a second polarization unit; the first polarization unit is arranged on the second side of the optical waveguide, and the image light emitted by the optical modulator is guided by the polarization beam splitter and then incident on the first polarization unit; the first polarization unit is used to convert the polarization state of the image light into a first linear polarization state, and reflect the image light in the first linear polarization state to the polarization beam splitter; the second polarization unit is arranged on the second side of the optical waveguide, and the image light emitted by the first polarization unit is guided by the polarization beam splitter and then incident on the second polarization unit; the second polarization unit is used to convert the polarization state of the image light into a second linear polarization state, and reflect the image light in the second linear polarization state to the polarization beam splitter; the polarization beam splitter is also used to guide the image light emitted by the second polarization unit to the optical waveguide.

[0010] In some possible embodiments, the first polarization unit includes a first quarter-wave plate and a first reflector; the first reflector is located on the optical path where the image light is located, and is used to reflect the image light; the first quarter-wave plate is arranged between the polarization beam splitter and the first reflector, and is located on the optical path where the image light is located.

[0011] In some possible embodiments, the second polarization unit includes a second quarter-wave plate and a second reflector; the second reflector is located on the optical path where the image light is located, and is used to reflect the image light; the second quarter-wave plate is arranged between the polarization beam splitter and the second reflector, and is located on the optical path where the image light is located.

[0012] In some possible embodiments, the first linear polarization state is an S polarization state; the polarization beam splitter has a first side surface and a second side surface in the first direction, and the polarization beam splitter has a third side surface and a fourth side surface in the second direction, and the first direction and the second direction intersect; the optical waveguide is arranged on the first side surface, and the second polarization unit is arranged on the second side surface; the light modulator is arranged on the third side surface, the illumination light is reflected to the light modulator via the polarization beam splitter, and the first polarization unit is arranged on the fourth side surface.

[0013] In some possible embodiments, the first linear polarization state is a P polarization state; the polarization beam splitter has a first side surface and a second side surface in the first direction, and the polarization beam splitter has a third side surface and a fourth side surface in the second direction, and the first direction and the second direction intersect; the optical waveguide is arranged on the first side surface, the light modulator is arranged on the second side surface, and the illumination light is transmitted to the light modulator through the polarization beam splitter; the second polarization unit is arranged on the third side surface, and the first polarization unit is arranged on the fourth side surface.

[0014] In some possible embodiments, the light guiding module further includes a first lens group and a second lens group; the first lens group is arranged between the polarization beam splitter and the optical waveguide, and is located on the optical path where the illumination light and the image light are located; the second lens group is arranged between the polarization beam splitter and the light modulator, and is located on the optical path where the illumination light and the image light are located.

[0015] According to a second aspect of the present application, an embodiment of the present application further provides a projection device, which includes a housing and the above-mentioned projection device, and the projection device is disposed in the housing.

[0016] Embodiments of the present application provide a projection device and projection equipment. The projection device includes an illumination module, an optical waveguide module, a light guiding module, and an optical modulator. The light guiding module is disposed on the optical path of the illumination light generated by the illumination module and is used to guide the illumination light to the optical modulator. The light guiding module is also disposed on the optical path of the image light generated by the optical modulator and is used to guide the image light to the optical waveguide. Therefore, the light guiding module in this embodiment multiplexes the illumination light path corresponding to the illumination light and the imaging light path corresponding to the image light, thereby reducing the overall volume of the projection device and achieving a miniaturized design of the projection equipment equipped with the projection device, thereby improving the wearing comfort and product competitiveness of the projection equipment.

[0017] Furthermore, the projection device in this embodiment is provided with an incoupling grating on the optical waveguide. On the one hand, the incoupling grating transmits light in a first linear polarization state, allowing the illumination light to smoothly pass through the incoupling grating and enter the light guiding module disposed on the second side of the optical waveguide. On the other hand, the incoupling grating deflects the propagation direction of light in a second linear polarization state, allowing the image light to change its propagation direction under the action of the incoupling grating, allowing the image light to propagate smoothly within the optical waveguide, thus ensuring smooth operation of the projection device. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0019] Figure 1 It is a structural schematic diagram of the projection device provided in an embodiment of the present application.

[0020] Figure 2 yes Figure 1 A structural schematic diagram of a projection device in a projection device is shown.

[0021] Figure 3 yes Figure 1 Another structural schematic diagram of the projection device in the projection equipment shown.

[0022] Figure 4 yes Figure 1 Another structural schematic diagram of the projection device in the projection equipment is shown.

[0023] Figure 5 yes Figure 1 FIG. 1 is a schematic diagram of another structure of the projection device in the projection equipment shown. DETAILED DESCRIPTION

[0024] In order to enable those skilled in the art to better understand the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0025] See also Figure 1 , an embodiment of the present application provides a projection device 100 and a projection equipment 200 equipped with the projection device 100. The projection device 200 may include the projection device 100 and a shell 201. The shell 201 serves to fix and protect the projection device 100. The projection device 100 can be used to generate and transmit image light carrying image information. When a user wears the projection device 200, the above-mentioned image light can be incident on the user's eyes, so that the user can see the image information generated by the projection device 200. Specifically, the projection device 200 can be an AR device (for example, AR glasses, AR head display, etc.).

[0026] See also Figure 2The projection device 100 in this embodiment may include an illumination module 10, an optical waveguide module 30, a light guiding module 50, and an optical modulator 70. The illumination module 10 is configured to generate an illumination light E having a first linear polarization state. The optical waveguide module 30 may include an optical waveguide 320 and an incoupling grating 340. The optical waveguide 320 has a first side 3201 and a second side 3203 opposite to each other. The illumination light E enters the optical waveguide 320 via the first side 3201 of the optical waveguide 320. The incoupling grating 340 is disposed in the optical waveguide 320 and is located on the optical path of the illumination light E. The incoupling grating 340 is configured to transmit light having the first linear polarization state. The light guiding module 50 is disposed on the second side 3203 of the optical waveguide 320 and is configured to guide the illumination light E transmitted through the incoupling grating 340 and the optical waveguide 320 to the optical modulator 70.

[0027] The light modulator 70 is disposed on the second side 3203 of the optical waveguide 320 and is configured to modulate the illumination light E to generate image light O having a second linear polarization state; the second linear polarization state is orthogonal to the first linear polarization state. The light guiding module 50 and the coupling grating 340 are also disposed in the optical path of the image light O. The light guiding module 50 is further configured to guide the image light O to the coupling grating 340. The coupling grating 340 is further configured to deflect the propagation direction of the light having the second linear polarization state, thereby allowing the image light O to propagate within the optical waveguide 320.

[0028] It is readily apparent that the light guiding module 50 in this embodiment is not only disposed on the optical path of the illumination light E generated by the illumination module 10, for guiding the illumination light E to the light modulator 70; it is also disposed on the optical path of the image light O generated by the light modulator 70, for guiding the image light O to the optical waveguide 320. Therefore, the light guiding module 50 in this embodiment multiplexes the illumination optical path corresponding to the illumination light E and the imaging optical path corresponding to the image light O, thereby reducing the overall volume of the projection apparatus 100 and achieving a compact design for the projection device 200 equipped with the projection apparatus 100, thereby enhancing the wearing comfort and product competitiveness of the projection device 200.

[0029] Furthermore, the projection device 100 in this embodiment is provided with an incoupling grating 340 on the optical waveguide 320. On the one hand, the incoupling grating 340 can transmit light in the first linear polarization state, so that the illumination light E can smoothly pass through the incoupling grating 340 and be incident on the light guiding module 50 disposed on the second side 3203 of the optical waveguide 320. On the other hand, the incoupling grating 340 can deflect the propagation direction of light in the second linear polarization state, so that the image light O can change its propagation direction under the action of the incoupling grating 340, allowing the image light O to propagate smoothly within the optical waveguide, thereby ensuring smooth operation of the projection device 100.

[0030] The following is an introduction to the various components in the projection device 100.

[0031] In this embodiment, the illumination module 10 is used to generate illumination light E, wherein the illumination light E may be laser light, and the polarization state of the illumination light E is a first linear polarization state. Exemplarily, the first linear polarization state may be a P polarization state or an S polarization state.

[0032] In some possible embodiments, the illumination module 10 may include a laser generator and a scattering unit (neither of which is shown in the figure). The laser generator is used to generate illumination light E, and the scattering unit is disposed on the optical path of the illumination light E to scatter the illumination light E to eliminate speckle in the illumination light E, thereby improving the imaging quality of the projection device 100. Specifically, the scattering unit may be a scattering sheet.

[0033] In some possible embodiments, such as Figure 2 As shown, the lighting module 10 can be arranged on the first side 3201 of the optical waveguide 320, so that the illumination light E generated by the lighting module 10 can be directly incident on the optical waveguide 320 through the first side 3201 of the optical waveguide 320, making the overall optical path of the projection device 100 simpler and more compact, and reducing the hardware cost of the projection device 100.

[0034] In some other possible embodiments, see Figure 3 The illumination module 10 can be disposed on the second side 3203 of the optical waveguide 320. The projection device 100 can further include a plurality of reflectors 120, which are sequentially disposed on the optical path of the illumination light E. The reflectors 120 are configured to reflect the illumination light E so that the reflected illumination light E can enter the optical waveguide 320 via the first side 3201 of the optical waveguide 320. In this embodiment, the illumination module 10 is disposed on the second side 3203 of the optical waveguide 320, i.e., the side where the light guiding module 50 and the light modulator 70 are located. This facilitates centralized heat dissipation of the illumination module 10, the light guiding module 50, and the light modulator 70, thereby improving the overall heat dissipation efficiency of the projection device 100.

[0035] In this embodiment, the optical waveguide module 30 guides and transmits the illumination light E and the image light O. The optical waveguide module 30 may include an optical waveguide 320, an incoupling grating 340, and an outcoupling grating 360. The optical waveguide 320 is generally sheet-shaped and may have a first side 3201 and a second side 3203 that are opposite to each other.

[0036] Specifically, the optical waveguide 320 can be a guiding structure composed of an optically transparent medium (e.g., quartz glass) that transmits optical-frequency electromagnetic waves. It can guide the image light O to continuously refract and propagate within it, thereby transmitting the image light O to the user's eyes. In this embodiment, the optical waveguide 320 is configured to transmit light of a first polarization state and reflect light of a second polarization state. In some possible embodiments, the optical waveguide 320 can be provided with an incoupling region 301, through which the illumination light E is coupled into the optical waveguide 320. The incoupling region 301 is located on a first side 3201 of the optical waveguide 320.

[0037] In this embodiment, the coupling-in grating 340 is disposed on the optical waveguide 320 and is located on the optical path of the illumination light E. Specifically, the coupling-in grating 340 can transmit light in a first linear polarization state, allowing the illumination light E to smoothly pass through the coupling-in grating 340 and enter the light guiding module 50 disposed on the second side 3203 of the optical waveguide 320. The coupling-in grating 340 can also deflect the propagation direction of light in a second linear polarization state, so that the image light O can change its propagation direction under the action of the coupling-in grating 340, allowing the image light O to propagate smoothly within the optical waveguide, thereby ensuring smooth operation of the projection device 100.

[0038] exist Figure 2 In the illustrated embodiment, the coupling grating 340 can be disposed on the first side 3201 of the optical waveguide 320, so that the illumination light E sequentially passes through the coupling grating 340 and the optical waveguide 320 before entering the light guiding module 50. In this case, after exiting the light guiding module 50, the image light O is incident on the location of the coupling grating 340 from the second side 3203 of the optical waveguide 320. The coupling grating 340 then changes the propagation direction of the image light O, causing the image light O to re-enter the optical waveguide 320 at a certain angle and be continuously reflected within the optical waveguide 320 under the action of the optical waveguide 320. Specifically, the coupling grating 340 can be attached to the first side 3201 of the optical waveguide 320, or embedded in the first side 3201 of the optical waveguide 320, to ensure a more secure and reliable connection between the coupling grating 340 and the optical waveguide 320.

[0039] Here, "changing the propagation direction of the image light O" can be understood as the "reflective diffraction" of the image light O on the surface of the coupling grating 340, so that the incident angle of the image light O is not equal to the exit angle. Therefore, when the image light O is roughly perpendicular to the coupling grating 340, the image light O can be reflected from the coupling grating 340 at a certain angle and then enter the optical waveguide 320, so as to ensure that the image light O can propagate smoothly in the optical waveguide 320. Figure 2In the embodiment shown, the coupling-in grating 340 may be a reflective diffraction grating, and more specifically, a holographic optical elements (HOE) grating.

[0040] exist Figure 3 In the illustrated embodiment, the coupling-in grating 340 can be disposed on the second side 3203 of the optical waveguide 320, so that the illumination light E sequentially passes through the optical waveguide 320 and the coupling-in grating 340 before entering the light guiding module 50. In this case, after exiting the light guiding module 50, the image light O directly enters the location of the coupling-in grating 340. The coupling-in grating 340 then changes the propagation direction of the image light O, causing the image light O to enter the optical waveguide 320 at a specific angle and be continuously reflected within the optical waveguide 320 under the action of the optical waveguide 320. Specifically, the coupling-in grating 340 can be attached to the second side 3203 of the optical waveguide 320, or embedded in the second side 3203 of the optical waveguide 320, to ensure a more secure and reliable connection between the coupling-in grating 340 and the optical waveguide 320.

[0041] Here, "changing the propagation direction of the image light O" can be understood as the "transmission diffraction" of the image light O on the surface of the coupling grating 340, so that the incident angle of the image light O is not equal to the exit angle. Therefore, when the image light O is roughly perpendicular to the coupling grating 340, the image light O can be transmitted from the coupling grating 340 at a certain angle and enter the optical waveguide 320 to ensure that the image light O can propagate smoothly in the optical waveguide 320. Figure 3 In the embodiment shown, the coupling-in grating 340 may be a transmissive diffraction grating, and more specifically, a holographic optical elements (HOE) grating.

[0042] In this embodiment, the optical waveguide 320 may further include an outcoupling region 303, through which the image light O is coupled out to the outside world. The outcoupling region 303 may be located at the second side 3203 of the optical waveguide 320, and the outcoupling grating 360 may be located at the first side 3201 of the optical waveguide 320. Figure 2 In the embodiment shown, the coupling-in grating 340 and the coupling-out grating 360 are arranged on the same side of the optical waveguide 320. Figure 3 In the illustrated embodiment, the incoupling grating 340 and the outcoupling grating 360 are disposed on different sides of the optical waveguide 320 .

[0043] Specifically, the outcoupling grating 360 is located on the optical path of the image light O and is configured to deflect the propagation direction of the image light O so that the deflected image light O is coupled out to the outside world via the outcoupling region 303. Specifically, the outcoupling grating 360 may be an HOE grating. When the image light O propagates to the location of the outcoupling grating 360, the outcoupling grating 360 diffracts the image light O to change the reflection direction of the image light O. This allows the image light O to be smoothly coupled out of the optical waveguide 320 under the action of the outcoupling grating 360, thereby ensuring smooth operation of the projection device 100.

[0044] In this embodiment, the light modulator 70 is arranged on the optical path of the illumination light E after being guided by the light guiding module 50, and is used to modulate the illumination light E to generate image light O with a polarization state of a second linear polarization state. The second linear polarization state is orthogonal to the first linear polarization state. For example, when the first linear polarization state is a P polarization state, the second linear polarization state is an S polarization state; when the first linear polarization state is an S polarization state, the second linear polarization state is a P polarization state. Specifically, the light modulator 70 can be a liquid crystal on silicon (LCoS) chip. Of course, the light modulator 70 can also be other non-self-luminous display chips that use polarized light as illumination light, which is not specifically limited in this embodiment.

[0045] In this embodiment, the light guiding module 50 is disposed on the optical path of the illumination light E generated by the illumination module 10 and is used to guide the illumination light E to the light modulator 70. The light guiding module 50 is also disposed on the optical path of the image light O generated by the light modulator 70 and is used to guide the image light O to the optical waveguide 320. Therefore, the light guiding module 50 in this embodiment multiplexes the illumination optical path corresponding to the illumination light E and the imaging optical path corresponding to the image light O, thereby reducing the overall volume of the projection device 100.

[0046] See also Figure 4 The light guiding module 50 may include a polarization beam splitter 520 (PBS), which is disposed on the second side 3203 of the optical waveguide 320. The polarization beam splitter 520 and the light modulator 70 are spaced apart. The polarization beam splitter 520 is disposed on the optical path of the illumination light E and the image light O, and is used to guide the illumination light E to the light modulator 70 and guide the image light O to the optical waveguide 320. Therefore, the polarization beam splitter 520 in this embodiment multiplexes the illumination light path corresponding to the illumination light E and the imaging light path corresponding to the image light O. The term "guiding" here can be understood as reflecting or transmitting light.

[0047] In this embodiment, the polarization beam splitter 520 has a first side surface 5201 and a second side surface 5203 in a first direction X, and has a third side surface 5205 and a fourth side surface 5207 in a second direction Y. The first direction X and the second direction Y intersect. The first side surface 5201, the fourth side surface 5207, the second side surface 5203, and the third side surface 5205 may be sequentially connected to define the outer periphery of the polarization beam splitter 520. In some possible embodiments, the first direction X and the second direction Y are perpendicular.

[0048] As an embodiment, the polarization beam splitter 520 may include a first prism, a second prism, and a polarization beam splitter film (all not shown in the figure). The first prism and the second prism may be isosceles right-angled triangular prisms, respectively, and the two oblique surfaces corresponding to the first prism and the second prism are aligned. Specifically, the first side surface 5201 and the third side surface 5205 may be the two right-angled surfaces corresponding to the first prism, respectively, and the second side surface 5203 and the fourth side surface 5207 may be the two right-angled surfaces corresponding to the second prism, respectively. The polarization beam splitter film is disposed between the oblique surfaces corresponding to the first prism and the second prism, and is used to transmit P-polarized light and reflect S-polarized light.

[0049] In this embodiment, the light guiding module 50 further includes a first polarization unit 540 and a second polarization unit 560. The first polarization unit 540 is disposed on the second side 3203 of the optical waveguide 320. The image light O emitted by the light modulator 70 is guided by the polarization beam splitter 520 and then incident on the first polarization unit 540. The first polarization unit 540 is configured to convert the polarization state of the image light O into a first linear polarization state and reflect the image light O in the first linear polarization state back to the polarization beam splitter 520.

[0050] Specifically, the first polarization unit 540 may include a first quarter-wave plate 5410 and a first reflector 5430. The first reflector 5430 and the polarization beam splitter 520 are spaced apart and located on the optical path of the image light O, and is used to reflect the image light O. The first quarter-wave plate 5410 is disposed between the polarization beam splitter 520 and the first reflector 5430 and located on the optical path of the image light O.

[0051] Since the image light O passes through the first quarter-wave plate 5410 twice during the process of propagating to the first reflector 5430 and being reflected by the first reflector 5430 to the polarization beam splitter 520, when the image light O is incident on the polarization beam splitter 520 again, the polarization state of the image light O is converted from the second linear polarization state to the first linear polarization state.

[0052] The second polarization unit 560 is disposed on the second side 3203 of the optical waveguide 320. The image light O emitted by the first polarization unit 540 is guided by the polarization beam splitter 520 and then incident on the second polarization unit 560. The second polarization unit 560 is configured to convert the polarization state of the image light O into a second linear polarization state and reflect the image light O in the second linear polarization state back to the polarization beam splitter 520.

[0053] Specifically, the second polarization unit 560 may include a second quarter-wave plate 5610 and a second reflector 5630. The second reflector 5630 is spaced apart from the polarization beam splitter 520 and is located on the optical path of the image light O, and is used to reflect the image light O. The second quarter-wave plate 5610 is disposed between the polarization beam splitter 520 and the second reflector 5630 and is located on the optical path of the image light O.

[0054] Since the image light O passes through the second quarter-wave plate 5610 twice during the process of propagating to the second reflector 5630 and being reflected by the second reflector 5630 to the polarization beam splitter 520, when the image light O is incident on the polarization beam splitter 520 again, the polarization state of the image light O is converted from the first linear polarization state to the second linear polarization state.

[0055] In this embodiment, the polarization beam splitter 520 is further configured to guide the image light O emitted from the second polarization unit 560 to the optical waveguide 320 .

[0056] The following combination Figure 4 and Figure 5 The specific arrangement positions and specific optical paths of the first polarization unit 540 and the second polarization unit 560 are described.

[0057] exist Figure 4 In the illustrated embodiment, the first linear polarization state is an S polarization state, that is, the illumination light E is S-polarized light. Specifically, the optical waveguide 320 is disposed on the first side 5201, and the second polarization unit 560 is disposed on the second side 5203. The light modulator 70 is disposed on the third side 5205, and the illumination light E is reflected by the polarization beam splitter 520 to the light modulator 70. The first polarization unit 540 is disposed on the fourth side 5207.

[0058] Therefore, when the illumination light E is incident from the first side surface 5201, it is reflected by the polarization beam splitter 520 and emitted to the light modulator 70 through the third side surface 5205 to generate image light O under the modulation of the light modulator 70. At this time, the image light O is P polarized light.

[0059] Image light O generated by the light modulator 70 is incident from the third side 5205 and, after being transmitted by the polarization beam splitter 520, is emitted through the fourth side 5207 to the first polarization unit 540. The first polarization unit 540 again reflects the image light O back to the polarization beam splitter 520. Here, due to the presence of the first quarter-wave plate 5410, the image light O is converted from P-polarized light to S-polarized light. When the image light O is incident from the fourth side 5207, it is reflected by the polarization beam splitter 520 and emitted through the second side 5203 to the second polarization unit 560.

[0060] The second polarization unit 560 reflects the image light O again toward the polarization beam splitter 520. Here, the image light O is converted from S-polarized light to P-polarized light due to the presence of the second quarter-wave plate 5610. Finally, when the image light O enters the second side surface 5203, it is transmitted through the polarization beam splitter 520 and exits the optical waveguide 320 through the first side surface 5201.

[0061] exist Figure 5 In the illustrated embodiment, the first linear polarization state is a P polarization state, that is, the illumination light E is P polarized light. Specifically, the optical waveguide 320 is disposed on the first side 5201, and the optical modulator 70 is disposed on the second side 5203. The illumination light E is transmitted to the optical modulator 70 via the polarization beam splitter 520. The second polarization unit 560 is disposed on the third side 5205, and the first polarization unit 540 is disposed on the fourth side 5207.

[0062] Therefore, when the illumination light E is incident from the first side 5201, it is transmitted by the polarization beam splitter 520 and emitted to the light modulator 70 through the second side 5203 to generate the image light O under the modulation of the light modulator 70. At this time, the image light O is S-polarized light.

[0063] The image light O generated by the light modulator 70 is incident from the second side 5203 and, after being reflected by the polarization beam splitter 520, is emitted from the fourth side 5207 to the first polarization unit 540. The first polarization unit 540 again reflects the image light O back to the polarization beam splitter 520. Here, due to the presence of the first quarter-wave plate 5410, the image light O is converted from S-polarized light to P-polarized light. When the image light O is incident from the fourth side 5207, it is transmitted by the polarization beam splitter 520 and emitted from the third side 5205 to the second polarization unit 560.

[0064] The second polarization unit 560 reflects the image light O again toward the polarization beam splitter 520. Here, the image light O is converted from P-polarized light to S-polarized light due to the presence of the second quarter-wave plate 5610. Finally, when the image light O enters from the third side 5205, it is reflected by the polarization beam splitter 520 and emitted from the first side 5201 to the optical waveguide 320.

[0065] Therefore, in Figure 4 and Figure 5 In the illustrated embodiment, by placing different optical devices (e.g., quarter-wave plates, reflectors, etc.) on the four sides of the polarization beam splitter 520 to fold the light path and perform polarization conversion, the illumination light path corresponding to the illumination light E and the imaging light path corresponding to the image light O can be reused, thereby reducing the overall volume of the projection device 100. Furthermore, the polarization beam splitter 520 in this embodiment also folds the light path, lengthening the light path within a limited space, making the illumination light path and the imaging light path more compact, thereby facilitating a miniaturized design of the projection device 200 equipped with the projection device 100.

[0066] In some possible embodiments, the light guiding module 50 may further include a first lens group 570 and a second lens group 580. The first lens group 570 is disposed between the polarization beam splitter 520 and the optical waveguide 320, and is located on the optical path of the illumination light E and the image light O. The second lens group 580 is disposed between the polarization beam splitter 520 and the light modulator 70, and is located on the optical path of the illumination light E and the image light O.

[0067] On the one hand, the illumination light E passes through the first lens group 570 and the second lens group 580 in sequence before being incident on the light modulator 70. The first lens group 570 and the second lens group 580 can perform light homogenization and shaping on the illumination light E to improve the uniformity of the corresponding light spot of the illumination light E, thereby improving the light quality of the illumination light E. On the other hand, the image light O passes through the second lens group 580 and the first lens group 570 in sequence before being incident on the optical waveguide 320. The second lens group 580 and the first lens group 570 can form an image of the image light O to improve the imaging quality of the image light O.

[0068] certainly, Figure 4 and Figure 5 The first reflector 5430 and the second reflector 5630 in the lens 580 also form an image of the image light O. Specifically, the image light O is formed by the second lens group 580, the first reflector 5430, the second reflector 5630 and the first lens group 570 in sequence. Figure 4 In the embodiment shown, the first reflector 5430 and the second reflector 5630 may be plane reflectors. Figure 5 In the illustrated embodiment, the first reflector 5430 and the second reflector 5630 may be curved reflectors, which may have the effect of shaping the image light O.

[0069] Therefore, the first lens group 570 and the second lens group 580 in this embodiment also realize the reuse of the illumination light path corresponding to the illumination light E and the imaging light path corresponding to the image light O. Specifically, the first lens group 570 may include one or more first lenses (not shown in the figure), wherein the first lens may be a positive lens or a negative lens, and the first lens may be a spherical lens or an aspherical lens. The second lens group 580 may include one or more second lenses (not shown in the figure), wherein the second lens may be a positive lens or a negative lens, and the second lens may be a spherical lens or an aspherical lens. This embodiment does not limit the specific implementation of the first lens group 570 and the second lens group 580.

[0070] The present invention provides a projection device 100 and a projection apparatus 200 equipped with the projection device 100. The projection device 100 may include an illumination module 10, an optical waveguide module 30, a light guiding module 50, and an optical modulator 70. The illumination module 10 is configured to generate illumination light E having a first linear polarization state. The optical waveguide module 30 may include an optical waveguide 320 and an incoupling grating 340. The optical waveguide 320 has a first side 3201 and a second side 3203 opposite to each other. The illumination light E enters the optical waveguide 320 via the first side 3201 of the optical waveguide 320. The incoupling grating 340 is disposed on the optical waveguide 320 and is located on the optical path of the illumination light E. The incoupling grating 340 is configured to transmit light having the first linear polarization state. The light guiding module 50 is disposed on the second side 3203 of the optical waveguide 320 and is configured to guide the illumination light E transmitted through the incoupling grating 340 and the optical waveguide 320 to the optical modulator 70.

[0071] The light modulator 70 is disposed on the second side 3203 of the optical waveguide 320 and is configured to modulate the illumination light E to generate image light O having a second linear polarization state; the second linear polarization state is orthogonal to the first linear polarization state. The light guiding module 50 and the coupling grating 340 are also disposed in the optical path of the image light O. The light guiding module 50 is further configured to guide the image light O to the coupling grating 340. The coupling grating 340 is further configured to deflect the propagation direction of the light having the second linear polarization state, thereby allowing the image light O to propagate within the optical waveguide 320.

[0072] It is readily apparent that the light guiding module 50 in this embodiment is not only disposed on the optical path of the illumination light E generated by the illumination module 10, for guiding the illumination light E to the light modulator 70; it is also disposed on the optical path of the image light O generated by the light modulator 70, for guiding the image light O to the optical waveguide 320. Therefore, the light guiding module 50 in this embodiment multiplexes the illumination optical path corresponding to the illumination light E and the imaging optical path corresponding to the image light O, thereby reducing the overall volume of the projection apparatus 100 and achieving a compact design for the projection device 200 equipped with the projection apparatus 100, thereby enhancing the wearing comfort and product competitiveness of the projection device 200.

[0073] Furthermore, the projection device 100 in this embodiment is provided with an incoupling grating 340 on the optical waveguide 320. On the one hand, the incoupling grating 340 can transmit light in the first linear polarization state, so that the illumination light E can smoothly pass through the incoupling grating 340 and be incident on the light guiding module 50 disposed on the second side 3203 of the optical waveguide 320. On the other hand, the incoupling grating 340 can deflect the propagation direction of light in the second linear polarization state, so that the image light O can change its propagation direction under the action of the incoupling grating 340, allowing the image light O to propagate smoothly within the optical waveguide, thereby ensuring smooth operation of the projection device 100.

[0074] In the specification of this application, certain words are used to refer to specific components in the specification and claims. Those skilled in the art should understand that hardware manufacturers may use different terms to refer to the same component. The specification and claims do not use the difference in name as a way to distinguish components, but use the difference in function of the components as the criterion for distinction. For example, "including" mentioned throughout the specification and claims is an open term and should be interpreted as "including but not limited to"; "substantially" means that those skilled in the art can solve the technical problem within a certain error range and basically achieve the technical effect.

[0075] In the description of this application, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "inside", etc. indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings. They are only used to simplify the description for the convenience of describing this application, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they should not be understood as limitations on this application.

[0076] In this application, unless otherwise expressly specified or limited, terms such as "mounted," "connected," "connect," and "fixed" should be interpreted broadly. For example, these terms may refer to fixed, removable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediary; internal communication between two components; or mere surface contact. Those skilled in the art will understand the specific meanings of these terms in this application based on the specific circumstances.

[0077] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0078] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of such features. Throughout the description of this application, "plurality" means at least two, for example, two, three, etc., unless otherwise specifically defined.

[0079] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not cause 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 projection device, characterized in that: The invention comprises an illumination module, an optical waveguide module, an optical guiding module and an optical modulator; the illumination module is used to generate illumination light with a polarization state of a first linear polarization state; The optical waveguide module includes an optical waveguide and an incoupling grating, wherein the optical waveguide has a first side and a second side opposite to each other, and the illumination light is incident on the optical waveguide via the first side of the optical waveguide; the incoupling grating is arranged in the optical waveguide and is located on the optical path of the illumination light, and is used to transmit the light of the first linear polarization state; The light guiding module is arranged on the second side of the optical waveguide, and is used to guide the illumination light transmitted through the coupling grating and the optical waveguide to the light modulator; The light modulator is disposed on the second side of the optical waveguide, and is used to modulate the illumination light to generate image light with a polarization state of a second linear polarization state; the second linear polarization state is orthogonal to the first linear polarization state; The light guiding module and the coupling grating are also arranged on the optical path where the image light is located, and the light guiding module is also used to guide the image light to the coupling grating; the coupling grating is also used to deflect the propagation direction of the light in the second linear polarization state so that the image light propagates in the optical waveguide.

2. The projection device according to claim 1, wherein: The lighting module is arranged on the first side of the optical waveguide.

3. The projection device according to claim 1, wherein: The light guiding module includes a polarization beam splitter, and the polarization beam splitter is arranged on the second side of the optical waveguide; The polarization beam splitter is arranged on the optical path of the illumination light and the image light, and is used to guide the illumination light to the light modulator and guide the image light to the optical waveguide.

4. The projection device according to claim 3, wherein: The light guiding module includes a first polarizing unit and a second polarizing unit; The first polarization unit is disposed on the second side of the optical waveguide, and the image light emitted by the light modulator is guided by the polarization beam splitter and then incident on the first polarization unit; the first polarization unit is used to convert the polarization state of the image light into a first linear polarization state, and reflect the image light in the first linear polarization state to the polarization beam splitter; The second polarization unit is arranged on the second side of the optical waveguide, and the image light emitted by the first polarization unit is guided by the polarization beam splitter and then incident on the second polarization unit; the second polarization unit is used to convert the polarization state of the image light into a second linear polarization state, and reflect the image light in the second linear polarization state to the polarization beam splitter; The polarization beam splitter is further used to guide the image light emitted by the second polarization unit to the optical waveguide.

5. The projection device according to claim 4, wherein: The first polarization unit includes a first quarter wave plate and a first reflector; The first reflector is located on the optical path where the image light is located, and is used to reflect the image light; the first quarter-wave plate is arranged between the polarization beam splitter and the first reflector, and is located on the optical path where the image light is located.

6. The projection device according to claim 4, wherein: The second polarization unit includes a second quarter wave plate and a second reflector; The second reflector is located on the optical path where the image light is located, and is used to reflect the image light; the second quarter-wave plate is arranged between the polarization beam splitter and the second reflector, and is located on the optical path where the image light is located.

7. The projection device according to any one of claims 4 to 6, characterized in that: The first linear polarization state is an S polarization state; the polarization beam splitter has a first side surface and a second side surface in a first direction, and the polarization beam splitter has a third side surface and a fourth side surface in a second direction, and the first direction and the second direction intersect; The optical waveguide is arranged on the first side surface, and the second polarization unit is arranged on the second side surface; The light modulator is disposed on the third side surface, the illumination light is reflected to the light modulator via the polarization beam splitter, and the first polarization unit is disposed on the fourth side surface.

8. The projection device according to any one of claims 4 to 6, characterized in that: The first linear polarization state is a P polarization state; the polarization beam splitter has a first side surface and a second side surface in a first direction, and the polarization beam splitter has a third side surface and a fourth side surface in a second direction, and the first direction and the second direction intersect; The optical waveguide is arranged on the first side surface, the optical modulator is arranged on the second side surface, and the illumination light is transmitted to the optical modulator via the polarization beam splitter; The second polarization unit is disposed on the third side surface, and the first polarization unit is disposed on the fourth side surface.

9. The projection device according to any one of claims 3 to 6, characterized in that: The light guiding module further comprises a first lens group and a second lens group; The first lens group is arranged between the polarization beam splitter and the optical waveguide, and is located on the optical path of the illumination light and the image light; The second lens group is arranged between the polarization beam splitter and the light modulator, and is located on the optical path of the illumination light and the image light.

10. A projection device, characterized in that: include: case; as well as The projection device according to any one of claims 1 to 9, wherein the projection device is arranged in the housing.

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