Projection device, display equipment and vehicle

Abstract

The utility model provides a projection device, display equipment and a vehicle, and relates to the technical field of display. The projection apparatus includes an image generation unit for generating image light. The diffusion screen is located on the light emitting side of the image generation unit and used for diffusing the image light projected by the image generation unit, the light incident surface of the diffusion screen is a curved surface, and the curvature of the light incident surface of the diffusion screen is not equal to zero. Therefore, the size of the projection device can be reduced while the display performance is improved.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of display technologies, and particularly to a projection device, a display device, and a vehicle. Background Art

[0002] With the development of intelligent vehicle technologies, in order to improve driving safety, a head-up display (HUD) is provided on a vehicle. The head-up display generally consists of an image generation unit (picture generation unit, PGU) and an optical system (mainly composed of various optical path components, such as a diffuser and a light reflection element). The image generation unit is used to generate image light for forming an image and project the image light outward. The optical system is used to perform operations such as folding and magnifying the image light projected by the image generation unit. Among them, the diffuser is used to diffuse the image light projected by the image generation unit, increase the diffusion angle of the image light, and achieve the purpose of expanding the eyebox. However, in order to ensure the display effect of the head-up display, the volume of the diffuser is relatively large, making it difficult to reduce the volume of the head-up display. Summary of the Utility Model

[0003] The embodiments of the present application provide a projection device, a display device, and a vehicle, which can improve the display performance while reducing the volume of the projection device.

[0004] In a first aspect of the embodiments of the present application, a projection device is provided. The projection device includes: an image generation unit for generating image light; and a diffuser located on the light-emitting side of the image generation unit and used for diffusing the image light projected by the image generation unit. The incident light surface of the diffuser is a curved surface with a non-zero curvature.

[0005] In the projection device provided by the embodiments of the present application, the incident light surface of the diffuser is set as a curved surface with a non-zero curvature, which can improve the display performance. At the same time, the volume of the diffuser is small, having little impact on the volume of the projection device. Therefore, setting the incident light surface of the diffuser as a curved surface can improve the display performance while reducing the volume of the projection device, which helps to miniaturize the projection device.

[0006] In some possible implementation manners, the incident light surface of the diffuser is a positive curved surface concave toward the light-emitting side of the diffuser.

[0007] In some possible implementation manners, the diffuser satisfies: 80mm < R < ∞, where R is the radius of curvature of the incident light surface of the diffuser, to avoid the incident light surface of the diffuser being too concave and help improve the imaging quality.

[0008] In some possible implementation manners, the incident light surface of the diffuser is a negative curved surface convex toward the image generation unit.

[0009] In some possible implementation manners, the diffuser screen satisfies: -80 mm < R < ∞, where R is the radius of curvature of the light incident surface of the diffuser screen, avoiding the light incident surface of the diffuser screen from being too convex, which helps to improve the imaging quality.

[0010] In some possible implementation manners, the light incident surface of the diffuser screen is a spherical surface, an aspherical surface, a cylindrical surface or a free-form surface.

[0011] In some possible implementation manners, the light incident surface of the diffuser screen is a positive cylindrical surface concave toward the light exit side of the diffuser screen, and the diffuser screen satisfies: 80 mm < R < ∞, where R is the radius of curvature of the light incident surface of the diffuser screen.

[0012] In some possible implementation manners, the light incident surface of the diffuser screen is a negative cylindrical surface convex toward the image generation unit, and the diffuser screen satisfies: -80 mm < R < ∞, where R is the radius of curvature of the light incident surface of the diffuser screen.

[0013] In some possible implementation manners, the image generation unit includes: an image source for generating image light; and a projection lens located on the light exit side of the image source and on the light incident side of the diffuser screen, and configured to project the image light generated by the image source onto the light incident surface of the diffuser screen.

[0014] In some possible implementation manners, the image source includes: a light source and a modulation device, where the modulation device is configured to modulate the light emitted by the light source to obtain image light including image information.

[0015] In some possible implementation manners, the modulation device is any one of a liquid crystal display, a liquid crystal on silicon, a digital micromirror device or a thin film transistor.

[0016] In some possible implementation manners, the projection lens satisfies: BFL ≥ 20 mm, where BFL is the back focal length of the projection lens. In this way, it is possible to avoid the optical path of the projection lens from being too short, which is beneficial to the setting of the rear optical path.

[0017] In some possible implementation manners, the projection lens satisfies: BFL / R ≥ 0.25, where BFL is the back focal length of the projection lens and R is the radius of curvature of the light incident surface of the diffuser screen. In this way, it is possible to effectively balance the imaging quality and the volume of the projection device.

[0018] In some possible implementation manners, the projection lens includes at least five lenses arranged along the optical axis from the object side to the image side. In this way, the imaging quality meets the requirements.

[0019] In some possible implementation manners, the number of lenses of the projection lens is less than or equal to ten. In this way, it is possible to reduce the optical path of the projection lens, which helps to reduce the volume of the projection lens.

[0020] A second aspect of an embodiment of the present application provides a display device, which includes a processor and a projection device as described in any one of the first aspects, wherein the processor is used to send image data to an image generating unit so that the image generating unit generates image light.

[0021] In some possible implementations, the display device further includes: a reflective device, which is used to reflect and image the image light projected by the projection device to form an image.

[0022] A third aspect of an embodiment of the present application provides a vehicle, which includes a display device as described in the second aspect.

[0023] In some possible implementations, the vehicle further includes a dashboard, and the display device is installed in the dashboard.

[0024] In some possible implementations, the vehicle further includes a windshield, and the image light emitted by the display device is incident on the windshield to form an image. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 A schematic diagram of an application scenario of a display device provided in an embodiment of the present application;

[0026] Figure 2 It is a structural schematic diagram of a display device in the related art;

[0027] Figure 3 for Figure 1 A schematic diagram of the structure of the projection device in FIG.

[0028] Figure 4 A schematic diagram of the structure of another projection device provided in an embodiment of the present application;

[0029] Figure 5 A schematic diagram of the structure of a projection device provided in Embodiment 1 of the present application;

[0030] Figure 6 for Figure 5 Spherical chromatic aberration diagram of the projection lens in;

[0031] Figure 7 for Figure 5 Astigmatism field curvature diagram of the projection lens in;

[0032] Figure 8 for Figure 5 Distortion diagram of the projection lens in ;

[0033] Fig. 9 A schematic diagram of the structure of a projection device provided in Embodiment 2 of the present application;

[0034] Fig.10 for Fig. 9Spherical chromatic aberration diagram of the projection lens in;

[0035] Fig.11 for Fig. 9 Astigmatism field curvature diagram of the projection lens in;

[0036] Fig.12 for Fig. 9 Distortion diagram of the projection lens in ;

[0037] Fig.13 A first structural schematic diagram of a projection device provided in Embodiment 3 of the present application;

[0038] Fig.14 for Fig.13 A second structural schematic diagram of the projection device shown;

[0039] Fig.15 for Fig.13 Spherical chromatic aberration diagram of the projection lens in;

[0040] Fig.16 for Fig.13 Astigmatism field curvature diagram of the projection lens in;

[0041] Fig.17 for Fig.13 Distortion diagram of the projection lens in ;

[0042] Fig.18 A first structural schematic diagram of a projection device provided in Embodiment 4 of the present application;

[0043] Fig.19 for Fig.18 A second structural schematic diagram of the projection device shown;

[0044] Fig. 20 for Fig.18 Spherical chromatic aberration diagram of the projection lens in;

[0045] Fig.21 for Fig.18 Astigmatism field curvature diagram of the projection lens in;

[0046] Fig. 22 for Fig.18 Distortion diagram of the projection lens in .

[0047] Description of reference numerals:

[0048] 100. Display device;

[0049] 110. Projection device;

[0050] 120. Reflection device;

[0051] 10. Diffuser screen; 111. Light incident surface; 112. Light exit surface;

[0052] 20. Image generating unit; 21. Image source; 211. Light source; 212. Modulation device; 213. Cover glass; 22. Projection lens; 221. Aperture;

[0053] G1, first lens; G2, second lens; G3, third lens; G4, fourth lens; G5, fifth lens; G6, sixth lens; G7, seventh lens; G8, eighth lens. DETAILED DESCRIPTION

[0054] The terms used in the implementation section of this application are only used to explain the specific embodiments of this application and are not intended to limit this application.

[0055] To facilitate understanding, the relevant technical terms involved in the embodiments of the present application are first explained and illustrated.

[0056] Focal length, also known as focal length, is a measure of the concentration or dispersion of light in an optical system. It refers to the vertical distance from the optical center of a lens or lens group to the focal plane when an infinitely distant scene forms a clear image on the focal plane through a lens or lens group.

[0057] The image side is the side where the image is located, with the lens as the boundary, and the side of the lens facing the image side is the image side of the lens.

[0058] Object side: the side where the modulation device (such as DMD) is located is the object side, and the side of the lens facing the object side is the object side surface.

[0059] The back focal length (BFL) is defined as the distance from the lens closest to the imaging surface to the modulation unit (such as DMD).

[0060] Optical power represents the ability of a lens to refract an incident parallel light beam.

[0061] Positive optical power means that the lens has a positive focal length and has the effect of converging light.

[0062] Negative optical power means that the lens has a negative focal length and has the effect of diverging light.

[0063] The aperture is a device used to control the amount of light that passes through the lens into an electronic device. It is usually inside the lens, and the aperture size is expressed in F# (F-number).

[0064] The aperture number F# is a relative value obtained by dividing the focal length of the lens by the diameter of the lens (the inverse of the relative aperture). The smaller the aperture number F#, the more light enters in the same unit time.

[0065] Axial chromatic aberration, also known as longitudinal chromatic aberration or position chromatic aberration, is a beam of light parallel to the optical axis that converges at different positions before and after passing through the lens. This aberration is called position chromatic aberration or axial chromatic aberration. This is because the positions of the images of different wavelengths of light are different, so that the imaging planes of the images of different colors of light cannot completely overlap when the final image is formed, and the complex light spreads out to form dispersion.

[0066] Distortion, also known as distortion, is the degree of distortion of the image formed by the optical system relative to the object itself. Distortion is due to the influence of aperture aberration. The height of the intersection of the main light of different fields of view with the Gaussian image plane after passing through the optical system is not equal to the ideal image height. The difference between the two is the distortion. Therefore, distortion only changes the imaging position of the off-axis object point on the ideal plane, causing the shape of the image to be distorted, but does not affect the clarity of the image.

[0067] The embodiment of the present application provides a display device 100 and a means of transportation, which may be a car, truck, motorcycle, bus, ship, airplane, helicopter, lawn mower, recreational vehicle, amusement park vehicle, construction equipment, tram, golf cart, train or cart, etc., and is not particularly limited in the embodiment of the present application.

[0068] The display device 100 may be a head up display (HUD), a projector, etc. The head up display may be a windshield (W)-HUD, an augmented reality head up display (AR-HUD), etc. The following description takes the display device 100 as a head up display as an example, and the display device 100 is set on a vehicle, for example Figure 1 As shown. Among them, Figure 1 A schematic diagram of an application scenario of the display device 100 provided in an embodiment of the present application.

[0069] The display device 100 is used to project the vehicle status information, external object indication information and navigation information into the driver's field of vision, so as to prevent the driver from looking down to view the information and improve driving safety. The status information includes but is not limited to information such as driving speed, mileage, fuel level, water temperature and light status. The external object indication information includes but is not limited to safe vehicle distance, surrounding obstacles and reversing images. The navigation information includes but is not limited to direction arrows, distance and driving time.

[0070] Exemplarily, the vehicle includes a dashboard, and in this case, the display device 100 can be installed in the dashboard to achieve hidden installation. Of course, the display device 100 can also be installed at other locations of the vehicle.

[0071] like Figure 1As shown, the vehicle also includes a windshield, and the image light emitted by the display device 100 is incident on the windshield to form an image. For example, the windshield reflects the image light emitted by the display device 100 to the front of the vehicle, forming a virtual image superimposed on the real environment outside the vehicle, thereby realizing enhanced display.

[0072] Figure 2 It is a structural schematic diagram of a display device in the related art.

[0073] In related technologies, such as Figure 2 As shown, the display device 200 includes an image generation unit 210 (picture generation unit, PGU) and a diffusion screen 220. The image generation unit 210 is used to generate image light that forms an image and project the image light outward. The diffusion screen 220 is used to diffuse the image light projected by the image generation unit, increase the diffusion angle of the image light, and achieve the purpose of expanding the eyebox. The diffusion screen 220 is a flat structure, and the light incident surface 230 of the diffusion screen 220 is a plane. In order to reduce the volume of the display device 200, the volume of the diffusion screen 220 is small, resulting in a small area of ​​the light incident surface 230 of the diffusion screen 220, which reduces the display effect. In addition, in order to ensure the display effect of the display device 200, the image generation unit 210 and the diffusion screen 220 are arranged at an angle, resulting in limited spatial layout of the display device 200 and difficulty in reducing the volume.

[0074] In view of this, the display device 100 provided in the embodiment of the present application sets the light incident surface 111 of the diffuser screen 10 as a curved surface with a non-zero curvature, which can improve the display performance and reduce the volume of the display device 100, thereby contributing to the miniaturization of the display device 100. In addition, when the image generation unit 20 is arranged at an angle to the diffuser screen 10, the volume of the display device 100 can also be reduced.

[0075] In the embodiment of the present application, the display device 100 includes a processor and a projection device 110 (eg Figure 1 As shown), the processor is used to send image data to the image generating unit 20 so that the image generating unit 20 generates image light.

[0076] The processor may be referred to as a front-end processor. The processor includes one or more processing units, for example, the processor may include an application processor (AP), a modem processor, a graphics processor (GPU), an image signal processor (ISP), a controller, a video codec, a digital signal processor (DSP), a baseband processor, and / or a neural-network processing unit (NPU). Different processing units may be independent devices or integrated into one or more processors.

[0077] In some possible implementations, see Figure 1 As shown, the display device 100 may further include: a reflective device 120, which is used to reflect the image light projected by the projection device 110 to form an image. Figure 1 As shown, the reflective device 120 is used to reflect the image light projected by the projection device 110 to the windshield, and the windshield reflects the image light to the outside of the vehicle to form a virtual image located in front of the vehicle.

[0078] The number of the reflective device 120 may be one (eg Figure 1 For example, the number of the reflective devices 120 may be two. Of course, the number of the reflective devices 120 may be more or less than two. When the number of the reflective devices 120 is multiple, the types of the multiple reflective devices 120 may be the same or different, or may be partially the same.

[0079] Exemplarily, the reflective device 120 may be a reflector, such as Figure 1 As shown, the reflective device 120 is a curved reflector.

[0080] It should be noted that the display device 100 may include other components in addition to the above-mentioned projection device 110, processor, and reflective device 120. For example, the display device 100 may also include a power module, a wireless communication module, an I / O interface, and the like.

[0081] Figure 3 for Figure 1 Schematic diagram of the structure of the projection device.

[0082] like Figure 3As shown, the projection device 110 includes an image generation unit 20 (picture generation unit, PGU) and a diffuser 10 (diffuser). The image generation unit 20 is used to generate image light and project the image light to the diffuser 10. The diffuser 10 is located on the light exit side of the image generation unit 20, and the diffuser 10 is used to diffuse the image light projected by the image generation unit 20 to increase the diffusion angle (divergence angle) of the image light.

[0083] It should be noted that, in addition to the PGU and the diffuser screen 10 , the projection device 110 may also include other optical elements. For example, a reflective element (not shown in the figure) may be arranged between the diffuser screen 10 and the PGU, and the reflective element is used to reflect the image light projected by the PGU to the diffuser screen 10 .

[0084] The image generation unit 20 is also called an optical machine. Figure 1 As shown, the image generation unit 20 includes an image source 21 and a projection lens 22. The image source 21 is used to generate image light. The projection lens 22 is located at the light exit side of the image source 21 and at the light entrance side of the diffuser screen 10. The projection lens 22 is used to project the image light generated by the image source 21 onto the light entrance surface 111 of the diffuser screen 10.

[0085] In one embodiment, Figure 1 As shown, the image source 21 includes a light source 211 and a modulation device 212, and the modulation device 212 is used to modulate the light emitted by the light source 211 to obtain image light including image information. The modulation device 212 includes but is not limited to a liquid crystal display (LCD), liquid crystal on silicon (LCOS), a digital micro-mirror device (DMD), and a thin film transistor (TFT).

[0086] In addition to the light source 211 and the modulation device 212, in some embodiments, the image source 21 may further include a cover glass 213 (CG), which is located on the light-emitting side of the modulation device 212 to protect the modulation device 212. The number of the cover glass 213 may be one or more, and is not limited here.

[0087] The diffuser 10 is also called a diffuser sheet, a light diffuser element, a diffuser plate or a diffuser element. The diffuser 10 may be made of polymethyl methacrylate (PMMA), polycarbonate (PC), optical glass, etc., which is not limited in the present application.

[0088] As shown Figure 3 in FIG. 1, the diffuser screen 10 has opposite incident light surface 111 and emergent light surface 112. Among them, the projection lens 22 projects the image light emitted from the image source 21 onto the incident light surface 111 of the diffuser screen 10, and the image light enters the interior of the diffuser screen 10 through the incident light surface 111 and exits from the emergent light surface 112 of the diffuser screen 10.

[0089] In the embodiment of the present application, as Figure 3 shown in FIG. 2, the incident light surface 111 of the diffuser screen 10 is a curved surface with a non-zero curvature, that is, the incident light surface 111 of the diffuser screen 10 is not a plane. When the volume of the diffuser screen 10 is fixed, the area of the incident light surface 111 with a curved surface structure is larger than the area of the incident light surface 111 with a plane structure. The larger the area of the incident light surface 111 of the diffuser screen 10, the greater the improvement in the display effect. Therefore, setting the incident light surface 111 of the diffuser screen 10 as a curved surface can improve the display performance, and at the same time, the volume of the diffuser screen 10 is small, which has little impact on the volume of the projection device 110 and helps to miniaturize the projection device 110. In addition, when the diffuser screen 10 and the image generation unit 20 are arranged at an angle, the volume of the projection device 110 can also be reduced.

[0090] Among them, the incident light surface 111 of the diffuser screen 10 can be a curved surface such as a spherical surface, an aspherical surface, a cylindrical surface or a free form surface.

[0091] In some possible implementation manners, the incident light surface 111 of the diffuser screen 10 is a positive curved surface concave toward the emergent light side of the diffuser screen 10, that is to say, the positive curved surface is a concave surface structure that is recessed inward from the incident light side to the emergent light side of the diffuser screen 10 (as Figure 3 shown in FIG. 3).

[0092] Since the curved surface can be a spherical surface, an aspherical surface, a cylindrical surface or a free form surface, etc., the incident light surface 111 of the diffuser screen 10 can be a positive curved surface such as a positive spherical surface, a positive aspherical surface, a positive cylindrical surface or a positive free form surface.

[0093] In one implementation manner, when the incident light surface 111 of the diffuser screen 10 is a positive curved surface, the diffuser screen 10 can satisfy: 80mm < R < ∞, where R is the radius of curvature of the incident light surface 111 of the diffuser screen 10, to avoid the incident light surface 111 of the diffuser screen 10 being too concave and help to improve the imaging quality.

[0094] Among them, the specific value of the radius of curvature of the incident light surface 111 of the diffuser screen 10 is not limited here. For example, the radius of curvature of the diffuser screen 10 can be 81mm, 50mm, 90mm, 100mm, etc.

[0095] Since the positive curved surface can be a positive spherical surface, a positive aspherical surface, a positive cylindrical surface, a positive free-form surface, etc., the radius of curvature of any one of the positive spherical surface, the positive aspherical surface, the positive cylindrical surface, and the positive free-form surface can satisfy: 80 mm < R < ∞.

[0096] Of course, in another embodiment, when the light incident surface 111 of the diffusion screen 10 is a positive curved surface, the radius of curvature of the light incident surface 111 of the diffusion screen 10 can also be less than or equal to 80 mm.

[0097] Figure 4 FIG. is a schematic structural diagram of another projection device provided by an embodiment of the present application.

[0098] In some other possible implementation manners, the light incident surface 111 of the diffusion screen 10 is a negative curved surface convex toward the image generation unit 20, that is to say, the negative curved surface is a convex surface structure protruding outward from the light exit side to the light incident side of the diffusion screen 10 (as Figure 4 shown).

[0099] Since the curved surface can be a spherical surface, an aspherical surface, a cylindrical surface, a free-form surface, etc., the light incident surface 111 of the diffusion screen 10 can be a negative curved surface such as a negative spherical surface, a negative aspherical surface, a negative cylindrical surface, or a negative free-form surface.

[0100] In one embodiment, when the light incident surface 111 of the diffusion screen 10 is a negative curved surface, the diffusion screen 10 can satisfy: -80 mm < R < ∞, where R is the radius of curvature of the light incident surface 111 of the diffusion screen 10, which can avoid the light incident surface 111 of the diffusion screen 10 from being overly convex and help improve the imaging quality.

[0101] Among them, no specific limitation is imposed on the specific value of the radius of curvature of the light incident surface 111 of the diffusion screen 10. For example, the radius of curvature of the diffusion screen 10 can be -78 mm, -50 mm, -40 mm, -30 mm, etc.

[0102] Since the negative curved surface can be a negative spherical surface, a negative aspherical surface, a negative cylindrical surface, a negative free-form surface, etc., the radius of curvature of any one of the negative spherical surface, the negative aspherical surface, the negative cylindrical surface, and the negative free-form surface can satisfy: -80 mm < R < ∞.

[0103] Of course, in another embodiment, when the light incident surface 111 of the diffusion screen 10 is a negative curved surface, the diffusion screen 10 can also satisfy: R < -80 mm.

[0104] In the embodiment of the present application, there is no limitation on the structure of the light emitting surface 112 of the diffuser screen 10. In one embodiment, the light emitting surface 112 of the diffuser screen 10 may be a curved surface, and the curvature of the light emitting surface 112 of the diffuser screen 10 is not equal to zero. Among them, the light emitting surface 112 of the diffuser screen 10 may be a negative curved surface convex outward from the light incident side to the light emitting side of the diffuser screen 10, or the light emitting surface 112 of the diffuser screen 10 may be a positive curved surface concave inward from the light incident side to the light incident side of the diffuser screen 10. In addition, the specific type of the light emitting surface 112 of the diffuser screen 10 may be a spherical surface, an aspherical surface, a cylindrical surface, a free-form surface, or the like. In another embodiment, the light emitting surface 112 of the diffuser screen 10 may also be a plane (such as Figure 3 or Figure 4 as shown).

[0105] When the light incident surface 111 and the light emitting surface 112 of the diffuser 10 are both curved surfaces, the light incident surface 111 and the light emitting surface 112 may be of the same type, for example, the light incident surface 111 and the light emitting surface 112 may both be cylindrical or spherical.

[0106] In order to match the projection lens 22 with the light incident surface 111 of the diffusion screen 10 to ensure the display effect, in some possible implementations, the projection lens 22 includes at least five lenses arranged along the optical axis from the object side to the image side. For example, the projection lens 22 may include 8 lenses (such as Figure 5 ), of course, the number of lenses can be more or less than 8.

[0107] In some embodiments, the number of lenses of the projection lens 22 may be less than or equal to ten. In this way, the optical path of the projection lens 22 can be reduced, which helps to reduce the volume of the projection lens 22.

[0108] In some embodiments, the projection lens may further include a stop 221 (eg, Figure 5 ), from the image side to the object side, the aperture 221 is located between the fourth lens and the fifth lens. Of course, the aperture 221 can also be set at other positions, for example, from the image side to the object side, the aperture 221 is set between the fifth lens and the sixth lens.

[0109] In some possible implementations, the projection lens 22 may satisfy: BFL≥20 mm, where BFL is the back focal length of the projection lens 22. In this way, it is possible to avoid the optical path of the projection lens 22 being too short, which is beneficial to the setting of the rear optical path.

[0110] Among them, the specific value of the back focal length BFL can be 20mm, 21mm, 25mm, 28mm, etc.

[0111] In some possible implementations, the projection lens 22 may satisfy: BFL / R≥0.25, where BFL is the back focal length of the projection lens 22 and R is the radius of curvature of the light incident surface 111 of the diffusion screen 10. In this way, the imaging quality and the volume of the projection device 110 can be effectively balanced.

[0112] Among them, the ratio of BFL / R can be 0.25, 0.3, 0.5, 0.7, etc.

[0113] The specific structure of the projection device 110 provided in the embodiment of the present application is described below in conjunction with specific embodiments.

[0114] Embodiment 1

[0115] Figure 5 This is a schematic diagram of the structure of a projection device 110 provided in Embodiment 1 of the present application.

[0116] The projection device 110 of the first embodiment of the present application includes an image generating unit 20 and a diffusion screen 10. Figure 5 As shown, the image generation unit 20 includes a projection lens 22, a cover glass 213 and a modulation device 212. The cover glass 213 is located at the light exit side of the modulation device 212 and at the light entrance side of the projection lens 22. The projection lens 22 includes a first lens G1, a second lens G2, a third lens G3, a fourth lens G4, an aperture 221, a fifth lens G5, a sixth lens G6, a seventh lens G7 and an eighth lens G8 arranged in sequence from the image side to the object side along the optical axis. The first lens G1 is closest to the light entrance surface 111 of the diffusion screen 10, and the eighth lens G8 is closest to the cover glass 213. The diffusion screen 10 is located at the light exit side of the projection lens 22, and the light entrance surface 111 of the diffusion screen 10 is a positive curved surface. Among them, the light entrance surface 111 of the diffusion screen 10 is a spherical surface, and the curvature radius R of the light entrance surface 111 of the diffusion screen 10 is 100 mm.

[0117] The first lens G1 has positive refractive power, and a focal length f1 of the first lens G1 is 34.702 mm.

[0118] The second lens G2 has negative power, and the focal length of the second lens G2 is f2=-16.242 mm.

[0119] The third lens G3 has negative power, and the focal length of the third lens G3 is f3=-52.068 mm.

[0120] The fourth lens element G4 has positive refractive power, and the focal length f4 of the fourth lens element G4 is 57.277 mm.

[0121] The fifth lens G5 and the sixth lens G6 form a cemented lens having positive refractive power, and the cemented lens has f56=128.384 mm.

[0122] The seventh lens G7 has positive refractive power, and the focal length of the seventh lens G7 is f7=78.874 mm.

[0123] The eighth lens G8 has positive refractive power, and the focal length f8 of the eighth lens G8 is 41.143 mm.

[0124] The back focal length BFL of the projection lens 22 is 27.51 mm, which is greater than 20 mm and meets the requirement. In addition, BFL / R is 0.2751, which is greater than 0.25 and meets the requirement.

[0125] Table 1 shows the optical parameters of the optical elements of the projection device 110 according to the first embodiment of the present application.

[0126]

[0127] Among them, S1 is the image side surface of the first lens G1, S2 is the object side surface of the first lens G1, S3 is the image side surface of the second lens G2, S4 is the object side surface of the second lens G2, S5 is the image side surface of the third lens G3, S6 is the object side surface of the third lens G3, S7 is the image side surface of the fourth lens G4, S8 is the object side surface of the fourth lens G4, S9 is the aperture 221, S10 is the image side surface of the fifth lens G5, and S11 is the image side surface of the fifth lens G5 and the sixth lens G 6, S12 is the image side surface of the sixth lens G6, S13 is the image side surface of the seventh lens G7, S14 is the object side surface of the seventh lens G7, S15 is the image side surface of the eighth lens G8, S16 is the object side surface of the eighth lens G8, S17 is the image side surface of the cover glass 213, S18 is the object side surface of the cover glass 213, S19 to S23 are the modulation device 212, OBJ is the light incident surface 111 of the diffusion screen 10, and ImgH is the imaging surface.

[0128] Wherein, R is the radius of curvature of the optical element (such as a lens or cover glass 213) at the position corresponding to the optical axis, TH is the surface thickness of the optical element along the optical axis, Nd is the refractive index of the d-line irradiated to each optical element, and Vd is the Abbe number of the optical element.

[0129] Table 2 shows Figure 5 Optical parameters of the projection lens 22 in .

[0130]

[0131] Wherein, f1 is the focal length of the first lens G1. f2 is the focal length of the second lens G2. f3 is the focal length of the third lens G3. f4 is the focal length of the fourth lens G4. f56 is the combined focal length of the fifth lens G5 and the sixth lens G6. f7 is the focal length of the seventh lens G7. f8 is the focal length of the eighth lens G8. EFL is the focal length of the projection lens 22. EFL(1-4) is the combined focal length of the front group consisting of the first lens G1 to the fourth lens G4. EFL(5-6) is the combined focal length of the front group consisting of the fifth lens G5 to the eighth lens G8. Fno is the aperture of the projection lens 22. BFL is the back focal length of the projection lens 22.

[0132] Figure 6 for Figure 5 Spherical chromatic aberration diagram of the projection lens 22 in FIG. Figure 6 In the figure, the ordinate represents the normalized pupil coordinate, and the abscissa represents the aberration in the axial direction, in millimeters. Figure 6 In FIG. 1 , the three curves correspond to the axial aberration curves of light with a wavelength of 625 nm, light with a wavelength of 550 nm, and light with a wavelength of 455 nm after passing through the projection lens 22 of this embodiment. Figure 6 It can be seen that in this embodiment, the axial aberration is controlled within a very small range and is well corrected.

[0133] Figure 7 for Figure 5 The astigmatism field curvature diagram of the projection lens 22 in FIG. Figure 8 for Figure 5 Distortion diagram of the projection lens 22 in FIG. Figure 7 In , S represents the field curvature value of the light with a wavelength of 550nm on the meridional image plane, and T represents the field curvature value of the light with a wavelength of 550nm on the sagittal image plane. Figure 8 In FIG. 1 , the solid line represents the distortion value of light having a central wavelength of 550 nm passing through the projection lens 22 of this embodiment. Figure 7 and Figure 8 It can be seen that the projection lens 22 provided in this embodiment controls the field curvature and distortion within a corresponding range, and can meet the use requirements.

[0134] Embodiment 2

[0135] Fig. 9 This is a schematic diagram of the structure of a projection device 110 provided in Embodiment 2 of the present application.

[0136] The projection device 110 of the second embodiment of the present application includes an image generating unit 20 and a diffusion screen 10. Fig. 9As shown, the image generation unit 20 includes a projection lens 22, a cover glass 213 and a modulation device 212. The cover glass 213 is located at the light exit side of the modulation device 212 and at the light entrance side of the projection lens 22. The projection lens 22 includes a first lens G1, a second lens G2, a third lens G3, a fourth lens G4, an aperture 221, a fifth lens G5, a sixth lens G6, a seventh lens G7 and an eighth lens G8 arranged in sequence from the image side to the object side along the optical axis. The first lens G1 is closest to the light entrance surface 111 of the diffusion screen 10, and the eighth lens G8 is closest to the cover glass 213. The diffusion screen 10 is located at the light exit side of the projection lens 22, and the light entrance surface 111 of the diffusion screen 10 is a negative curved surface. Among them, the light entrance surface 111 of the diffusion screen 10 is a spherical surface, and the curvature radius R of the light entrance surface 111 of the diffusion screen 10 is -100 mm.

[0137] The first lens G1 has positive refractive power, and a focal length f1 of the first lens G1 is 35.591 mm.

[0138] The second lens G2 has negative power, and the focal length of the second lens G2 is f2=-16.482 mm.

[0139] The third lens G3 has negative power, and the focal length of the third lens G3 is f3=-50.897 mm.

[0140] The fourth lens G4 has positive refractive power, and the focal length f4 of the fourth lens G4 is 50.176 mm.

[0141] The fifth lens G5 and the sixth lens G6 constitute a cemented lens having positive refractive power, and the cemented lens has f56=115.227 mm.

[0142] The seventh lens G7 has positive refractive power, and the focal length of the seventh lens G7 is f7=86.44 mm.

[0143] The eighth lens G8 has positive refractive power, and the focal length f8 of the eighth lens G8 is 40.864 mm.

[0144] The back focal length BFL of the projection lens 22 is 27.726 mm, which is greater than 20 mm and meets the requirement. In addition, BFL / R is 0.27726, which is greater than 0.25 and meets the requirement.

[0145] Table 3 shows the optical parameters of the optical elements of the projection device 110 according to the second embodiment of the present application.

[0146]

[0147] Among them, S1 is the image side surface of the first lens G1, S2 is the object side surface of the first lens G1, S3 is the image side surface of the second lens G2, S4 is the object side surface of the second lens G2, S5 is the image side surface of the third lens G3, S6 is the object side surface of the third lens G3, S7 is the image side surface of the fourth lens G4, S8 is the object side surface of the fourth lens G4, S9 is the aperture 221, S10 is the image side surface of the fifth lens G5, and S11 is the image side surface of the fifth lens G5 and the sixth lens G 6, S12 is the image side surface of the sixth lens G6, S13 is the image side surface of the seventh lens G7, S14 is the object side surface of the seventh lens G7, S15 is the image side surface of the eighth lens G8, S16 is the object side surface of the eighth lens G8, S17 is the image side surface of the cover glass 213, S18 is the object side surface of the cover glass 213, S19 to S23 are the modulation device 212, OBJ is the light incident surface 111 of the diffusion screen 10, and ImgH is the imaging surface.

[0148] Wherein, R is the radius of curvature of the optical element (such as a lens or cover glass 213) at the position corresponding to the optical axis, TH is the surface thickness of the optical element along the optical axis, Nd is the refractive index of the d-line irradiated to each optical element, and Vd is the Abbe number of the optical element.

[0149] Table 4 shows Fig. 9 Optical parameters of the projection lens 22 in .

[0150]

[0151] Wherein, f1 is the focal length of the first lens G1. f2 is the focal length of the second lens G2. f3 is the focal length of the third lens G3. f4 is the focal length of the fourth lens G4. f56 is the combined focal length of the fifth lens G5 and the sixth lens G6. f7 is the focal length of the seventh lens G7. f8 is the focal length of the eighth lens G8. EFL is the focal length of the projection lens 22. EFL(1-4) is the combined focal length of the front group consisting of the first lens G1 to the fourth lens G4. EFL(5-6) is the combined focal length of the front group consisting of the fifth lens G5 to the eighth lens G8. Fno is the aperture of the projection lens 22. BFL is the back focal length of the projection lens 22.

[0152] Fig.10 for Fig. 9 Spherical chromatic aberration diagram of the projection lens 22 in FIG. Fig.10 In the figure, the ordinate represents the normalized pupil coordinate, and the abscissa represents the aberration in the axial direction, in millimeters. Fig.10 In FIG. 1 , the three curves correspond to the axial aberration curves of light with a wavelength of 625 nm, light with a wavelength of 550 nm, and light with a wavelength of 455 nm after passing through the projection lens 22 of this embodiment. Fig.10It can be seen that in this embodiment, the axial aberration is controlled within a very small range and is well corrected.

[0153] Fig.11 for Fig. 9 The astigmatism field curvature diagram of the projection lens 22 in FIG. Fig.12 for Fig. 9 Distortion diagram of the projection lens 22 in FIG. Fig.11 In , S represents the field curvature value of the light with a wavelength of 550nm on the meridional image plane, and T represents the field curvature value of the light with a wavelength of 550nm on the sagittal image plane. Fig.12 In FIG. 1 , the solid line represents the distortion value of light having a central wavelength of 550 nm passing through the projection lens 22 of this embodiment. Fig.10 and Fig.11 It can be seen that the projection lens 22 provided in this embodiment controls the field curvature and distortion within a corresponding range, and can meet the use requirements.

[0154] Embodiment 3

[0155] Fig.13 This is a first structural schematic diagram of a projection device 110 provided in Embodiment 3 of the present application. Fig.14 for Fig.13 The second structural diagram of the projection device 110 is shown. Fig.13 is a schematic diagram of the structure of the projection device 110 in the vertical direction, Fig.13 1 is a schematic diagram of the structure of the projection device 110 in the horizontal direction. The horizontal direction, the vertical direction and the optical axis direction of the projection lens 22 are perpendicular to each other.

[0156] The projection device 110 of the third embodiment of the present application includes an image generation unit 20 and a diffusion screen 10. The image generation unit 20 includes a projection lens 22, a cover glass 213 and a modulation device 212. Fig.13 As shown, the cover glass 213 is located at the light exiting side of the modulation device 212 and at the light entering side of the projection lens 22. The projection lens 22 includes a first lens G1, a second lens G2, a third lens G3, a fourth lens G4, an aperture 221, a fifth lens G5, a sixth lens G6, a seventh lens G7 and an eighth lens G8 arranged in sequence from the image side to the object side along the optical axis. The first lens G1 is closest to the light incident surface 111 of the diffusion screen 10, and the eighth lens G8 is closest to the cover glass 213. The diffusion screen 10 is located at the light exiting side of the projection lens 22, and the light incident surface 111 of the diffusion screen 10 is a positive curved surface. Among them, the light incident surface 111 of the diffusion screen 10 is a cylindrical surface, and the curvature radius Ry of the light incident surface 111 of the diffusion screen 10 in the vertical direction is 100 mm, and the curvature radius Rx of the light incident surface 111 of the diffusion screen 10 in the horizontal direction is infinite, that is, the curvature of the light incident surface 111 of the diffusion screen 10 in the horizontal direction is 0.

[0157] The first lens G1 has positive refractive power, and a focal length f1 of the first lens G1 = 340.283 mm.

[0158] The second lens G2 has negative power, and the focal length of the second lens G2 is f2=-34.226 mm.

[0159] The third lens G3 has negative power, and the focal length of the third lens G3 is f3=-19.827 mm.

[0160] The fourth lens G4 has positive refractive power, and the focal length f4 of the fourth lens G4 is 36.255 mm.

[0161] The fifth lens G5 and the sixth lens G6 constitute a cemented lens having negative refractive power, and the cemented lens has f56=-314.912 mm.

[0162] The seventh lens G7 has positive refractive power, and the focal length of the seventh lens G7 is f7=47.444 mm.

[0163] The eighth lens G8 has positive refractive power, and the focal length f8 of the eighth lens G8 is 37.630 mm.

[0164] The back focal length BFL of the projection lens 22 is 27.85 mm, which is greater than 20 mm and meets the requirement. In addition, BFL / R is 0.2785, which is greater than 0.25 and meets the requirement.

[0165] Table 5 shows the optical parameters of each optical element of the projection device 110 according to the third embodiment of the present application.

[0166]

[0167] Among them, S1 is the image side surface of the first lens G1, S2 is the object side surface of the first lens G1, S3 is the image side surface of the second lens G2, S4 is the object side surface of the second lens G2, S5 is the image side surface of the third lens G3, S6 is the object side surface of the third lens G3, S7 is the image side surface of the fourth lens G4, S8 is the object side surface of the fourth lens G4, S9 is the aperture 221, S10 is the image side surface of the fifth lens G5, and S11 is the image side surface of the fifth lens G5 and the sixth lens G 6, S12 is the image side surface of the sixth lens G6, S13 is the image side surface of the seventh lens G7, S14 is the object side surface of the seventh lens G7, S15 is the image side surface of the eighth lens G8, S16 is the object side surface of the eighth lens G8, S17 is the image side surface of the cover glass 213, S18 is the object side surface of the cover glass 213, S19 to S23 are the modulation device 212, OBJ is the light incident surface 111 of the diffusion screen 10, and ImgH is the imaging surface.

[0168] Wherein, R is the radius of curvature of the optical element (such as a lens or cover glass 213) at the position corresponding to the optical axis, TH is the surface thickness of the optical element along the optical axis, Nd is the refractive index of the d-line irradiated to each optical element, and Vd is the Abbe number of the optical element.

[0169] Table 6 shows Fig.13 Optical parameters of the projection lens 22 in .

[0170]

[0171] Wherein, f1 is the focal length of the first lens G1. f2 is the focal length of the second lens G2. f3 is the focal length of the third lens G3. f4 is the focal length of the fourth lens G4. f56 is the combined focal length of the fifth lens G5 and the sixth lens G6. f7 is the focal length of the seventh lens G7. f8 is the focal length of the eighth lens G8. EFL is the focal length of the projection lens 22. EFL(1-4) is the combined focal length of the front group consisting of the first lens G1 to the fourth lens G4. EFL(5-6) is the combined focal length of the front group consisting of the fifth lens G5 to the eighth lens G8. Fno is the aperture of the projection lens 22. BFL is the back focal length of the projection lens 22.

[0172] Fig.15 for Fig.13 Spherical chromatic aberration diagram of the projection lens 22 in FIG. Fig.15 In the figure, the ordinate represents the normalized pupil coordinate, and the abscissa represents the aberration in the axial direction, in millimeters. Fig.15 In FIG. 1 , the three curves correspond to the axial aberration curves of light with a wavelength of 625 nm, light with a wavelength of 550 nm, and light with a wavelength of 455 nm after passing through the projection lens 22 of this embodiment. Fig.15 It can be seen that in this embodiment, the axial aberration is controlled within a very small range and is well corrected.

[0173] Fig.16 for Fig.13 The astigmatism field curvature diagram of the projection lens 22 in FIG. Fig.17 for Fig.13 Distortion diagram of the projection lens 22 in FIG. Fig.16 In , S represents the field curvature value of the light with a wavelength of 550nm on the meridional image plane, and T represents the field curvature value of the light with a wavelength of 550nm on the sagittal image plane. Fig.17 In FIG. 1 , the solid line represents the distortion value of light having a central wavelength of 550 nm passing through the projection lens 22 of this embodiment. Fig.16 and Fig.17 It can be seen that the projection lens 22 provided in this embodiment controls the field curvature and distortion within a corresponding range, and can meet the use requirements.

[0174] Embodiment 4

[0175] Fig.18 This is a first structural schematic diagram of a projection device 110 provided in Embodiment 4 of the present application. Fig.19 for Fig.18 The second structural diagram of the projection device 110 is shown. Fig.18 is a schematic diagram of the structure of the projection device 110 in the vertical direction, Fig.19 1 is a schematic diagram of the structure of the projection device 110 in the horizontal direction. The horizontal direction, the vertical direction and the optical axis direction of the projection lens 22 are perpendicular to each other.

[0176] The projection device 110 of the fourth embodiment of the present application includes an image generation unit 20 and a diffusion screen 10. The image generation unit 20 includes a projection lens 22, a cover glass 213 and a modulation device 212. Fig.18 As shown, the cover glass 213 is located at the light exiting side of the modulation device 212 and at the light entering side of the projection lens 22. The projection lens 22 includes a first lens G1, a second lens G2, a third lens G3, a fourth lens G4, an aperture 221, a fifth lens G5, a sixth lens G6, a seventh lens G7 and an eighth lens G8 arranged in sequence from the image side to the object side along the optical axis. The first lens G1 is closest to the light incident surface 111 of the diffusion screen 10, and the eighth lens G8 is closest to the cover glass 213. The diffusion screen 10 is located at the light exiting side of the projection lens 22, and the light incident surface 111 of the diffusion screen 10 is a negative curved surface. Among them, the light incident surface 111 of the diffusion screen 10 is a negative cylindrical surface, and the curvature radius Ry of the light incident surface 111 of the diffusion screen 10 in the vertical direction is -100 mm, and the curvature radius Rx of the light incident surface 111 of the diffusion screen 10 in the horizontal direction is infinite, that is, the curvature of the light incident surface 111 of the diffusion screen 10 in the horizontal direction is 0.

[0177] The first lens G1 has positive refractive power, and a focal length f1 of the first lens G1 is 52.349 mm.

[0178] The second lens G2 has positive refractive power, and the focal length f2 of the second lens G2 is 52.075 mm.

[0179] The third lens G3 has negative power, and the focal length of the third lens G3 is f3=-9.369 mm.

[0180] The fourth lens element G4 has positive refractive power, and a focal length f4 of the fourth lens element G4 is 37.962 mm.

[0181] The fifth lens G5 and the sixth lens G6 form a cemented lens having positive refractive power, and the cemented lens has f56=245.521 mm.

[0182] The seventh lens G7 has positive refractive power, and the focal length of the seventh lens G7 is f7=54.013 mm.

[0183] The eighth lens G8 has positive refractive power, and the focal length f8 of the eighth lens G8 is 45.555 mm.

[0184] The back focal length BFL of the projection lens 22 is 27.850 mm, which is greater than 20 mm and meets the requirement. In addition, BFL / R is 0.2785, which is greater than 0.25 and meets the requirement.

[0185] Table 7 shows the optical parameters of each optical element of the projection device 110 according to the third embodiment of the present application.

[0186]

[0187] Among them, S1 is the image side surface of the first lens G1, S2 is the object side surface of the first lens G1, S3 is the image side surface of the second lens G2, S4 is the object side surface of the second lens G2, S5 is the image side surface of the third lens G3, S6 is the object side surface of the third lens G3, S7 is the image side surface of the fourth lens G4, S8 is the object side surface of the fourth lens G4, S9 is the aperture 221, S10 is the image side surface of the fifth lens G5, and S11 is the image side surface of the fifth lens G5 and the sixth lens G 6, S12 is the image side surface of the sixth lens G6, S13 is the image side surface of the seventh lens G7, S14 is the object side surface of the seventh lens G7, S15 is the image side surface of the eighth lens G8, S16 is the object side surface of the eighth lens G8, S17 is the image side surface of the cover glass 213, S18 is the object side surface of the cover glass 213, S19 to S23 are the modulation device 212, OBJ is the light incident surface 111 of the diffusion screen 10, and ImgH is the imaging surface.

[0188] Wherein, R is the radius of curvature of the optical element (such as a lens or cover glass 213) at the position corresponding to the optical axis, TH is the surface thickness of the optical element along the optical axis, Nd is the refractive index of the d-line irradiated to each optical element, and Vd is the Abbe number of the optical element.

[0189] Table 8 shows Fig.18 Optical parameters of the projection lens 22 in .

[0190]

[0191] Wherein, f1 is the focal length of the first lens G1. f2 is the focal length of the second lens G2. f3 is the focal length of the third lens G3. f4 is the focal length of the fourth lens G4. f56 is the combined focal length of the fifth lens G5 and the sixth lens G6. f7 is the focal length of the seventh lens G7. f8 is the focal length of the eighth lens G8. EFL is the focal length of the projection lens 22. EFL(1-4) is the combined focal length of the front group consisting of the first lens G1 to the fourth lens G4. EFL(5-6) is the combined focal length of the front group consisting of the fifth lens G5 to the eighth lens G8. Fno is the aperture of the projection lens 22. BFL is the back focal length of the projection lens 22.

[0192] Fig. 20 for Fig.18 Spherical chromatic aberration diagram of the projection lens 22 in FIG. Fig. 20 In the figure, the ordinate represents the normalized pupil coordinate, and the abscissa represents the aberration in the axial direction, in millimeters. Fig. 20 In FIG. 1 , the three curves correspond to the axial aberration curves of light with a wavelength of 625 nm, light with a wavelength of 550 nm, and light with a wavelength of 455 nm after passing through the projection lens 22 of this embodiment. Fig. 20 It can be seen that in this embodiment, the axial aberration is controlled within a very small range and is well corrected.

[0193] Fig.21 for Fig.18 The astigmatism field curvature diagram of the projection lens 22 in FIG. Fig. 22 for Fig.18 Distortion diagram of the projection lens 22 in FIG. Fig.21 In , S represents the field curvature value of the light with a wavelength of 550nm on the meridional image plane, and T represents the field curvature value of the light with a wavelength of 550nm on the sagittal image plane. Fig. 22 In FIG. 1 , the solid line represents the distortion value of light having a central wavelength of 550 nm passing through the projection lens 22 of this embodiment. Fig.21 and Fig. 22 It can be seen that the projection lens 22 provided in this embodiment controls the field curvature and distortion within a corresponding range, and can meet the use requirements.

[0194] In the description of the embodiments of the present application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, or it can be an indirect connection through an intermediate medium, it can be the internal connection of two components or the interaction relationship between two components. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances. The terms "first", "second", "third", "fourth", etc. (if any) are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence.

[0195] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the embodiments of the present application, rather than to limit them. Although the embodiments of the present application have 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 replace some or all of the technical features therein by equivalents. These modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A projection device, characterized in that: Comprising: An image generation unit for generating image light; A diffusing screen located on the light-emitting side of the image generation unit and used for diffusing the image light projected by the image generation unit, wherein the incident light surface of the diffusing screen is a curved surface with a non-zero curvature; Wherein, the image generation unit includes: An image source for generating the image light; A projection lens located on the light-emitting side of the image source and on the light-incident side of the diffusing screen, and used for projecting the image light generated by the image source onto the incident light surface of the diffusing screen, the projection lens including at least five lenses arranged along the optical axis from the object side to the image side.

2. The projection device according to claim 1, characterized in that: The incident light surface of the diffusing screen is a positive curved surface concave towards the light-emitting side of the diffusing screen.

3. The projection device according to claim 2, characterized in that: The diffusing screen satisfies: 80mm < R < ∞, where R is the radius of curvature of the incident light surface of the diffusing screen.

4. The projection device according to claim 1, characterized in that: The incident light surface of the diffusing screen is a negative curved surface convex towards the image generation unit.

5. The projection device according to claim 4, characterized in that: The diffusing screen satisfies: -80mm < R < ∞, where R is the radius of curvature of the incident light surface of the diffusing screen.

6. The projection device according to claim 1, characterized in that: The incident light surface of the diffusing screen is a spherical surface, an aspherical surface, a cylindrical surface or a free-form surface.

7. The projection device according to claim 6, characterized in that: The incident light surface of the diffusing screen is a positive cylindrical surface concave towards the light-emitting side of the diffusing screen, and the diffusing screen satisfies: 80mm < R < ∞, where R is the radius of curvature of the incident light surface of the diffusing screen.

8. The projection device according to claim 6, characterized in that: The incident light surface of the diffusing screen is a negative cylindrical surface convex towards the image generation unit, and the diffusing screen satisfies: -80mm < R < ∞, where R is the radius of curvature of the incident light surface of the diffusing screen.

9. The projection device according to any one of claims 1 to 8, characterized in that: The image source includes: A light source; A modulation device for modulating the light emitted by the light source to obtain the image light including image information.

10. The projection device according to claim 9, characterized in that: The modulation device is any one of a liquid crystal display, liquid crystal on silicon, digital micromirror device or thin film transistor.

11. The projection device according to any one of claims 1 to 8, characterized in that: The projection lens satisfies: BFL ≥ 20mm, where BFL is the back focal length of the projection lens.

12. The projection device according to any one of claims 1 to 8, characterized in that: The projection lens satisfies: BFL / R ≥ 0.25, where BFL is the back focal length of the projection lens and R is the radius of curvature of the incident light surface of the diffusing screen.

13. The projection device according to any one of claims 1 to 8, characterized in that: The number of lenses of the projection lens is less than or equal to ten.

14. A display device, characterized in that: Including a processor and a projection device according to any one of claims 1-13, the processor being configured to send image data to the image generation unit so that the image generation unit generates the image light.

15. The display device according to claim 14, characterized in that: The display device further includes: a reflection device for reflecting and imaging the image light projected by the projection device to form an image.

16. A means of transport, characterized in that: Including a display device according to claim 14 or 15.

17. The vehicle according to claim 16, characterized in that: The vehicle further includes an instrument panel, and the display device is installed in the instrument panel.

18. The vehicle according to claim 17, characterized in that: The vehicle further includes a windshield, and the image light emitted by the display device is incident on the windshield to form an image.

Images