Lens, projection device, display device and vehicle

Abstract

The embodiment of the invention provides a lens, a projection device, a display device and a vehicle, and belongs to the technical field of optics. The lens comprises a first lens group, a diaphragm and a second lens group which are arranged from an image side to an object side. The first lens group comprises at least three lenses, along the direction from the image side to the object side, the first lens closest to the image side in the first lens group has negative focal power, the second lens has positive focal power, and the third lens has negative focal power. The second lens group comprises at least three lenses, and along the direction from the image side to the object side, the second lens closest to the diaphragm in the second lens group has positive focal power, and the third lens has positive focal power. The lens provided by the embodiment of the invention can meet the projection requirements of high definition and high reliability.

Description

Technical Field

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

[0002] With the development of intelligent vehicle technologies, augmented reality head-up displays (AR-HUDs) have gradually become the mainstream configuration of automotive intelligent cockpits. Through an augmented reality head-up display, an image to be displayed can be fused with the real-time road surface, so that a driver can see information such as the running speed, navigation, and signal lights of the vehicle while looking at the road surface, thus eliminating the need to look down at the instrument panel or the central control display below the steering wheel, and further greatly improving the braking reaction time in case of an emergency and enhancing driving safety. In related technologies, an in-vehicle head-up display includes a projection optical machine and a projection lens. The projection optical machine modulates information such as navigation and instruments to be displayed into a light beam and projects it onto the projection lens, and the projection lens projects the image light beam onto a projection surface, so that the real-time road surface is fused with the information to be displayed. However, existing projection lenses have the problem of low clarity. Summary of the Invention

[0003] The embodiments of the present application provide a lens, a projection device, a display device, and a vehicle, which can improve the clarity of the lens to meet the high-definition projection requirements.

[0004] In a first aspect of the present application, a lens is provided, which includes a first lens group, a diaphragm, and a second lens group arranged from the image side to the object side. The first lens group includes at least three lenses. Along the direction from the image side to the object side, the first lens closest to the image side in the first lens group has a negative focal power, the second lens has a positive focal power, and the third lens has a negative focal power. The second lens group includes at least three lenses. Along the direction from the image side to the object side, the second lens closest to the diaphragm in the second lens group has a positive focal power, and the third lens has a positive focal power.

[0005] Since the focal power structure of the three lenses closest to the image side in the first lens group is a negative-positive-negative structure, and the focal powers of the second lens and the third lens closest to the diaphragm in the second lens group are both positive, the imaging ability of the lens can be improved, and further the clarity of the lens can be improved to meet the high-definition lens requirements. In addition, the reliability of the lens can also be improved to meet the high-reliability lens requirements.

[0006] In a possible implementation, the lens satisfies the relationship: 100 mm ≤ L ≤ 150 mm, where L is the distance between the image side surface of the lens closest to the image side and the projection image surface.

[0007] When the distance between the lens closest to the image side in the lens and the projection image plane is between 100 mm and 150 mm, the clarity can be further improved to meet the requirements of a high-definition lens.

[0008] In a possible implementation, the lens satisfies the relationship: 12.5 mm ≤ EFL ≤ 14.5 mm, where EFL is the focal length of the lens.

[0009] When the focal length of the lens is between 12.5 mm and 14.5 mm, the imaging ability of the lens can be further improved, and the clarity of the lens can be further improved.

[0010] In a possible implementation, the lens satisfies the relationship: -94 mm ≤ R1 ≤ 367 mm, where R1 refers to the radius of curvature of the image side of the lens closest to the image side in the lens.

[0011] When the radius of curvature of the image side of the lens closest to the image side in the lens is between -94 mm and 367 mm, it is possible to avoid the image side of the lens closest to the image side in the lens from being too flat, which is beneficial to aberration correction. In addition, it is also possible to avoid the image side of the lens closest to the image side in the lens from being too convex, which is beneficial to packaging, transportation or assembly.

[0012] In a possible implementation, the lens satisfies the relationship: -113 mm ≤ R2 ≤ 30 mm, where R2 refers to the radius of curvature of the object side of the lens closest to the object side in the lens.

[0013] When the radius of curvature of the object side of the lens closest to the object side in the lens is between -113 mm and 30 mm, it is possible to avoid the object side of the lens closest to the object side in the lens from being too flat, which is beneficial to aberration correction. In addition, it is also possible to avoid the object side of the lens closest to the object side in the lens from being too convex, which is beneficial to packaging, transportation or assembly.

[0014] In a possible implementation, the lens satisfies the relationship: -7 ≤ R1 / EFL ≤ 27, where R1 refers to the radius of curvature of the image side of the lens closest to the image side in the lens, and EFL is the focal length of the lens.

[0015] When the ratio of the radius of curvature of the image side of the lens closest to the image side in the lens to the focal length of the lens is between -7 and 27, it is possible to avoid the image side of the lens closest to the image side in the lens from being too flat, which is beneficial to aberration correction. In addition, it is also possible to avoid the image side of the lens closest to the image side in the lens from being too convex, which is beneficial to packaging, transportation or assembly.

[0016] In a possible implementation, the lens satisfies the relationship: -8.5 ≤ R2 / EFL ≤ -0.15, where R2 refers to the radius of curvature of the object side of the lens closest to the object side in the lens, and EFL is the focal length of the lens.

[0017] When the ratio of the curvature radius of the object side surface of the lens closest to the object side in the lens to the focal length of the lens is between -8.5 and -0.15, it is possible to avoid the object side surface of the lens closest to the object side from being too flat, which is beneficial to aberration correction. In addition, it is also possible to avoid the object side surface of the lens closest to the object side from being too convex, which is beneficial to packaging, transportation or assembly.

[0018] In a possible implementation, the lens satisfies the relationship: 25 mm ≤ BFL ≤ 30 mm, where BFL is the back focal length of the lens.

[0019] When the back focal length of the lens is between 25 mm and 30 mm, it is possible to avoid the optical path of the lens from being too long or too short, and the application range of the lens can be improved. Among them, if the optical path of the lens is too long, it is not conducive to design. If the optical path of the lens is too short, it is not conducive to the setting of the rear optical path.

[0020] In a possible implementation, the first lens group satisfies the relationship: -18 mm ≤ EFL1 ≤ 9 mm, where EFL1 refers to the focal length of the first lens group.

[0021] When the focal length of the first lens group is between -18 mm and 9 mm, the imaging ability of the lens can be further improved, and the clarity can be further improved. In addition, the compactness of the lens can also be improved.

[0022] In a possible implementation, the second lens group satisfies the relationship: 12.58 mm ≤ EFL2 ≤ 15.98 mm, where EFL2 refers to the focal length of the second lens group.

[0023] When the focal length of the second lens group is between 12.58 mm and 15.98 mm, the imaging ability of the lens can be further improved, and the clarity can be further improved. In addition, the compactness of the lens can also be improved. In addition, the matching degree of the chief ray angle of the rear-end chip (such as a digital micromirror array) and the chief ray angle of the lens can be improved to improve the optical efficiency.

[0024] In a possible implementation, along the direction from the image side to the object side, the first lens closest to the aperture in the second lens group has a positive or negative optical power.

[0025] When the first lens closest to the aperture in the second lens group has a positive or negative optical power, the imaging ability of the lens can be further improved.

[0026] In a possible implementation, the first lens group includes a first lens with a negative focal power, a second lens with a positive focal power, and a third lens with a negative focal power arranged from the image side to the object side. The first lens is closest to the image side, and the third lens is closest to the aperture stop. The second lens group includes a fourth lens, a fifth lens with a positive focal power, and a sixth lens with a positive focal power arranged from the image side to the object side. The fourth lens is closest to the aperture stop, and the sixth lens is closest to the object side.

[0027] When the first lens group is composed of a first lens with a negative focal power, a second lens with a positive focal power, and a third lens with a negative focal power, and the second lens group is composed of a fourth lens, a fifth lens with a positive focal power, and a sixth lens with a positive focal power, the imaging ability of the lens can be improved to meet the requirements of high-definition and high-reliability lenses. In addition, the number of lenses can be reduced to reduce the cost of the lens.

[0028] The second aspect of the present application provides a projection device, including a display unit and a lens as described in any one of the first aspects. The second lens group of the lens is close to the display unit. Among them, the display unit is used to emit image light to the lens.

[0029] The third aspect of the present application provides a display device, including an imaging module and a projection device as described in the second aspect. Among them, the imaging module generates a target image based on the image light emitted by the projection device.

[0030] The fourth aspect of the present application provides a vehicle, including a display device as described in the third aspect.

[0031] In a possible implementation, the display device is installed in the instrument panel of the vehicle.

[0032] In a possible implementation, the vehicle further includes a windshield. The image light emitted by the display device is incident on the windshield, and the windshield reflects the image light to the human eye. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1A It is a schematic structural diagram of the usage scenario of the display device provided by the embodiment of the present application;

[0034] Figure 1B It is a schematic structural diagram of a display device installed on a vehicle provided by the embodiment of the present application;

[0035] Figure 2 It is a schematic structural diagram of a lens provided by the embodiment of the present application;

[0036] Figure 3 It is a schematic structural diagram of a second projection device provided by Embodiment 1 of the present application;

[0037] Figure 4 ForFigure 3 Spherical aberration chromaticity diagram of the lens in

[0038] Figure 5 is Figure 3 Astigmatism field curvature diagram of the lens in

[0039] Figure 6 is Figure 4 Distortion diagram of the lens in

[0040] Figure 7 Schematic structural diagram of the third projection device provided in the second embodiment of the present application;

[0041] Figure 8 is Figure 7 Spherical aberration chromaticity diagram of the lens in

[0042] Figure 9 is Figure 7 Astigmatism field curvature diagram of the lens in

[0043] Figure 10 is Figure 7 Distortion diagram of the lens in

[0044] Figure 11 Schematic structural diagram of the fourth projection device provided in the third embodiment of the present application;

[0045] Figure 12 is Figure 11 Spherical aberration chromaticity diagram of the lens in

[0046] Figure 13 is Figure 11 Astigmatism field curvature diagram of the lens in

[0047] Figure 14 is Figure 11 Distortion diagram of the lens in

[0048] Figure 15 Schematic structural diagram of the fifth projection device provided in the fourth embodiment of the present application;

[0049] Figure 16 is Figure 15 Spherical aberration chromaticity diagram of the lens in

[0050] Figure 17 is Figure 15 Astigmatism field curvature diagram of the lens in

[0051] Figure 18 is Figure 15 Distortion diagram of the lens in

[0052] Figure 19 Schematic structural diagram of the sixth projection device provided in the fifth embodiment of the present application;

[0053] Figure 20 is Figure 19 the spherical aberration chromatic aberration diagram of the lens in

[0054] Figure 21 is Figure 19 the astigmatism field curvature diagram of the lens in

[0055] Figure 22 is Figure 19 the distortion diagram of the lens in

[0056] Description of the reference numerals in the drawings:

[0057] 100, lens;

[0058] 10, first lens group; 11, first lens; 12, second lens; 13, third lens;

[0059] 20, aperture stop;

[0060] 30, second lens group; 31, fourth lens; 32, fifth lens; 33, sixth lens;

[0061] 200, modulation unit;

[0062] 300, cover glass;

[0063] 400, projection device;

[0064] 500, display device;

[0065] 600, imaging module;

[0066] 700, display unit; 710, light source. Detailed implementation manners

[0067] The terms used in the implementation manners part of this application are only used to explain the specific embodiments of this application, and are not intended to limit this application.

[0068] For ease of understanding, first, relevant technical terms involved in the embodiments of this application are explained and described.

[0069] The focal length, also known as the focal length, is a measure of the aggregation or divergence of light in an optical system. It refers to the perpendicular 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 the lens or lens group.

[0070] Image side: Taking the lens as the boundary, the side where the image is located is the image side, and the side of the lens facing the image side is the image side of the lens.

[0071] Object side: The side where the modulation unit (such as DMD) is located is the object side, and the side of the lens facing the object side is the object side of the lens.

[0072] The back focal length (BFL) is defined as the distance from the lens closest to the imaging plane to the modulation unit (such as a DMD).

[0073] The optical power characterizes the refractive ability of a lens for an incident parallel light beam.

[0074] A positive optical power indicates that the lens has a positive focal length and has the effect of converging light rays.

[0075] A negative optical power indicates that the lens has a negative focal length and has the effect of diverging light rays.

[0076] The aperture is a device used to control the amount of light passing through the lens and entering the interior of the electronic device. It is usually inside the lens, and the aperture size is expressed by the F# (F-number) value.

[0077] The aperture number F# is the relative value obtained by dividing the focal length of the lens by the clear aperture diameter of the lens (the reciprocal of the relative aperture). The smaller the F# value of the aperture number, the more light enters in the same unit time.

[0078] The cover glass (CG) is used to protect the modulation unit (such as a DMD).

[0079] The modulation unit is used to modulate the light beam emitted by the light source to generate the image light directed towards the lens.

[0080] The projection chip is used to modulate the light beam emitted by the light source to generate the image light directed towards the lens.

[0081] The digital micromirror device (DMD) is used to reflect light to form an image.

[0082] Liquid crystal on silicon (LCOS) is used to reflect light to form an image.

[0083] Axial chromatic aberration, also known as longitudinal chromatic aberration or position chromatic aberration, is a phenomenon where a parallel light beam along the optical axis 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 lens forms images of light of different wavelengths at different positions, resulting in the imaging planes of different colors of light not completely coinciding during the final imaging, and the polychromatic light spreads to form chromatic dispersion.

[0084] Distortion, also known as aberration, refers to the degree of distortion of the image formed by an optical system with respect to the object itself. Distortion is caused by the influence of diaphragm aberration. The height of the chief ray of different fields of view passing through the optical system and intersecting with the Gaussian image plane is not equal to the ideal image height. The difference between the two is the distortion. Therefore, distortion only changes the imaging position of off-axis object points on the ideal plane, causing the shape of the image to be distorted, but does not affect the clarity of the image.

[0085] In recent years, an augmented reality (AR) head-up display (AR-HUD) has been proposed, which can fuse the AR effect projected and displayed by the HUD with real road surface information, enhancing the driver's acquisition of road surface information and realizing functions such as AR navigation and AR warning. In related technologies, the enhanced display head-up display includes a projection optical machine and a projection lens. The projection optical machine is used to modulate information such as navigation and instruments to be displayed into imaging light beams and project them onto the projection lens. The projection lens projects the imaging light beams onto the projection surface to form an image, enabling the real-time road surface to be fused with the information to be displayed. However, existing projection lenses have problems such as low clarity and low reliability, resulting in poor imaging quality and being unable to meet the projection requirements of high clarity and high reliability.

[0086] In view of this, embodiments of the present application provide a lens 100, a projection device 400, a display device 500, and a vehicle. The lens 100 has strong imaging ability, can improve the clarity of the image, and meet the projection requirements of high clarity. In addition, the lens 100 has high reliability and can meet the projection requirements of high reliability.

[0087] The vehicle provided by the embodiments of the present application may include, but is not limited to, cars, trucks, motorcycles, buses, ships, airplanes, helicopters, lawn mowers, recreational vehicles, amusement park vehicles, construction equipment, trams, golf carts, trains, or handcarts, etc. For example, in the embodiments of the present application, a car is used as an example of the above vehicle for illustration. Therefore, the vehicle may include components such as a windshield and an instrument panel.

[0088] The display device 500 provided by the embodiments of the present application may be a display, a television, a head-up display, etc. For example, in the embodiments of the present application, a head-up display is used as an example of the above display device 500 for illustration, as Figure 1A shown, Figure 1AThis is a schematic structural diagram of the usage scenario of the display device provided by the embodiments of the present application. Among them, a head-up display (hereinafter referred to as HUD) can project navigation information, instrument information, etc. within the driver's forward field of view, avoiding the driver from looking down at this information and thus affecting driving safety. After the image projected by the HUD is reflected by the windshield, a virtual image is formed outside the vehicle, and these virtual images can be superimposed on the real environment outside the vehicle, enabling the driver to obtain the visual effect of augmented reality (AR), thereby realizing functions such as AR navigation, adaptive cruise control, and lane departure warning. Among them, the types of HUD include but are not limited to windshield (W)-HUD, augmented reality head-up display (AR-HUD), etc.

[0089] Figure 1B This is a schematic structural diagram of a display device provided by the embodiments of the present application installed on a vehicle.

[0090] See Figure 1B As shown, the display device 500 can be installed in the instrument panel of the vehicle to achieve hidden installation. In addition, the image light emitted by the display device 500 can be incident on the windshield, and the windshield can reflect the image light to the human eye, enabling the human eye to see the virtual image located outside the windshield.

[0091] Continue to see Figure 1B As shown, the display device 500 can include a projection device 400 and an imaging module 600. Among them, the imaging module 600 can generate a target image based on the image light emitted by the projection device 400.

[0092] Among them, the imaging module 600 can reflect the image light emitted by the projection device 400 to the windshield, and the windshield reflects the image light to the human eye to form a target image.

[0093] Regarding the specific structure of the imaging module 600, there is no limitation here. Exemplarily, as Figure 2 shown, the imaging module 600 can include a curved mirror, and the curved mirror is used to reflect the image light emitted by the projection device 400 to the windshield, and the windshield can reflect the image light to the human eye. In addition, since the concave surface of the curved mirror can reflect the imaging light, the image generated by the projection device 400 can be magnified by the curved mirror, and the user can see the magnified virtual image.

[0094] See Figure 1B As shown, the projection device 400 can include a display unit 700 and a lens 100. The display unit 700 is used to emit image light to the lens 100, and the lens transmits the image light to the imaging module 600.

[0095] Among them, the display unit 700 may include a light source 710 and a modulation unit 200. The light source 710 is used to generate a light beam carrying the image data of the input image. The modulation unit 200 is used to modulate the light beam according to the image data and generate image light.

[0096] Regarding the specific structure of the modulation unit 200, no limitation is imposed here. Exemplarily, the modulation unit 200 may be a projection chip. Among them, the projection chip may be a reflective spatial light modulator and has the function of changing the polarization direction of the incident linearly polarized light, such as an LCoS. Or, the projection chip may also be a reflective spatial light modulator and does not have the function of changing the polarization direction of the incident linearly polarized light, such as a MEMS or a DMD. Or, the projection chip may also be a transmissive spatial light modulator, such as an LCD, etc.

[0097] In some possible implementation manners, the projection device 400 may further include a cover glass 300. Along the direction from the image side to the object side, the cover glass 300 is disposed between the lens 100 and the modulation unit 200, and the cover glass 300 can protect the modulation unit 200. The number of the cover glasses 300 may be one or more, and no limitation is imposed here. When the number of the cover glasses 300 is multiple, all the cover glasses 300 are disposed between the modulation unit 200 and the lens 100.

[0098] Next, the lens 100 provided by the embodiments of the present application will be described in detail with reference to the accompanying drawings.

[0099] Figure 2 It is a schematic structural diagram of a lens provided by the embodiments of the present application.

[0100] Combined with Figure 2 It can be seen that the lens 100 of the embodiments of the present application includes a first lens group 10, a diaphragm 20, and a second lens group 30 arranged from the image side to the object side. Among them, the first lens group 10 includes at least three lenses. For example, Figure 2 as shown, the first lens group 10 may include three lenses. Of course, the number of lenses in the first lens group 10 may also be more or less than three. Along the direction from the image side to the object side, the first lens closest to the image side in the first lens group 10 has a negative optical power, the second lens has a positive optical power, and the third lens has a negative optical power. The second lens group 30 includes at least three lenses. For example, Figure 2 as shown, the second lens group 30 may include three lenses. Of course, the number of lenses in the second lens group 30 may also be more or less than three. Along the direction from the image side to the object side, the second lens closest to the diaphragm 20 in the second lens group 30 has a positive optical power and the third lens has a positive optical power.

[0101] Combined with Figure 2It can be known that, since the optical power structure of the three lenses closest to the image side in the first lens group 10 is a negative-positive-negative structure, and the optical powers of the second lens and the third lens closest to the aperture 20 in the second lens group 30 are both positive optical powers, the imaging ability of the lens 100 can be improved, and further the clarity of the lens 100 can be improved to meet the requirements of a high-definition lens 100. In addition, the reliability of the lens 100 can also be improved to meet the requirements of a high-reliability lens 100.

[0102] There is no limitation on the number of lenses in the first lens group 10 and the number of lenses in the second lens group 30. Exemplarily, for example Figure 2 As shown, both the first lens group 10 and the second lens group 30 are composed of three lenses. Among them, as Figure 2 shown, the first lens group 10 may include a first lens 11 with a negative optical power, a second lens 12 with a positive optical power, and a third lens 13 with a negative optical power arranged from the image side to the object side. The first lens 11 is closest to the image side, and the third lens 13 is closest to the aperture 20. For example Figure 2 shown, the second lens group 30 may include a fourth lens 31, a fifth lens 32 with a positive optical power, and a sixth lens 33 with a positive optical power arranged from the image side to the object side. The fourth lens 31 is closest to the aperture 20, and the sixth lens 33 is closest to the object side.

[0103] When the first lens group 10 is composed of a first lens 11 with a negative optical power, a second lens 12 with a positive optical power, and a third lens 13 with a negative optical power, and the second lens group 30 is composed of a fourth lens 31, a fifth lens 32 with a positive optical power, and a sixth lens 33 with a positive optical power, the imaging ability of the lens 100 can be improved to meet the requirements of a high-definition and high-reliability lens 100. In addition, the number of lenses can also be reduced to reduce the cost of the lens 100.

[0104] It should be noted that when the number of lenses in the first lens group 10 is at least four, the lenses in the first lens group 10 except for the three lenses closest to the image side are arranged between the third lens closest to the image side and the aperture 20, that is, between the third lens 13 and the aperture 20. Similarly, when the number of lenses in the second lens group 30 is at least four, the lenses in the second lens group 30 except for the three lenses closest to the aperture 20 are arranged between the third lens closest to the aperture 20 and the object side (or the modulation unit 200), that is, between the third lens 13 and the object side (or the modulation unit 200).

[0105] In some possible implementation manners, the lens 100 may further satisfy the relational expression: 100mm ≤ L ≤ 150mm, where L is the distance between the image side surface of the lens closest to the image side in the lens 100 and the projection image plane (as Figure 2 L shown in

[0106] Correspondingly, when the distance between the lens closest to the image side in the lens 100 and the projection image plane is between 100 mm and 150 mm, the clarity can be further improved to meet the requirements of the high-definition lens 100.

[0107] There is no limitation on the specific value of L here. Among them, L can be 100 mm, 105 mm, 110 mm, 115 mm, 120 mm, 121 mm, 125 mm, 128 mm, 130 mm, 131.5 mm, 135 mm, 139 mm, 140 mm, 143 mm, 145.5 mm, 148 mm or 150 mm, etc.

[0108] In some possible implementation manners, the lens 100 can further satisfy the relational expression: 12.5 mm ≤ EFL ≤ 14.5 mm, where EFL is the focal length of the lens 100.

[0109] Correspondingly, when the focal length of the lens 100 is between 12.5 mm and 14.5 mm, the imaging ability of the lens 100 can be further improved, and the clarity of the lens 100 can be further improved.

[0110] There is no limitation on the specific value of the focal length of the lens 100 here. Among them, the focal length of the lens 100 can be 12.5 mm, 12.6165 mm, 13 mm, 13.325 mm, 13.5 mm, 13.6 mm, 13.99 mm, 14.0 mm, 14.1 mm, 14.2 mm, 14.3 mm, 14.4 mm or 14.5 mm, etc.

[0111] In some possible implementation manners, the lens 100 can further satisfy the relational expression: -94 mm ≤ R1 ≤ 367 mm, where R1 refers to the radius of curvature of the image side of the lens closest to the image side in the lens 100.

[0112] Correspondingly, when the radius of curvature of the image side of the lens closest to the image side in the lens 100 is between -94 mm and 367 mm, it is possible to avoid the image side of the lens closest to the image side in the lens 100 from being too flat, which is beneficial to aberration correction. In addition, it is also possible to avoid the image side of the lens closest to the image side in the lens 100 from being too convex, which is beneficial to packaging, transportation or assembly.

[0113] There is no restriction on the specific value of R1. Among them, the value of R1 can be -94mm, -90mm, -60mm, -30mm, -10mm, 10mm, 40.1mm, 40.5mm, 45mm, 49mm, 50mm, 55mm, 59mm, 65mm, 66mm, 69.698mm, 100mm, 150mm, 200mm, 250mm, 260mm, 300mm, 350mm, 360mm, 365mm or 366.985mm, etc.

[0114] In some possible implementation manners, the lens 100 can further satisfy the relational expression: -113mm ≤ R2 ≤ 30mm, where R2 refers to the radius of curvature of the object side surface of the lens closest to the object side in the lens 100.

[0115] Correspondingly, when the radius of curvature of the object side surface of the lens closest to the object side in the lens 100 is between -113mm and 30mm, it is possible to avoid the object side surface of the lens closest to the object side in the lens 100 from being too flat, which is beneficial to aberration correction. In addition, it is also possible to avoid the object side surface of the lens closest to the object side in the lens 100 from being too convex, which is beneficial to packaging, transportation or assembly.

[0116] There is no restriction on the specific value of R2. Among them, the value of R2 can be -113mm, -90mm, -50mm, -30mm, -10mm, 10mm, 17.5mm, 17.95mm, 18mm, 18.5mm, 19mm, 19.5mm, 20mm, 25mm, 28mm, 29mm or 30mm, etc.

[0117] In some possible implementation manners, the lens 100 can further satisfy the relational expression: -7 ≤ R1 / EFL ≤ 27, where R1 refers to the radius of curvature of the image side surface of the lens closest to the image side in the lens 100, and EFL is the focal length of the lens 100.

[0118] Correspondingly, when the ratio of the radius of curvature of the image side surface of the lens closest to the image side in the lens 100 to the focal length of the lens 100 is between -7 and 27, it is possible to avoid the image side surface of the lens closest to the image side in the lens 100 from being too flat, which is beneficial to aberration correction. In addition, it is also possible to avoid the image side surface of the lens closest to the image side in the lens 100 from being too convex, which is beneficial to packaging, transportation or assembly.

[0119] There is no limitation on the specific ratio of R1 / EFL. Among them, the ratio of R1 / EFL can be -7, -6.982, -5, -3, -1, -0.49, -0.45, -0.40, -0.35, -0.30, -0.25, -0.2, -0.15, -0.10, 0.1, 0.5, 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.7, 1.8, 1.9, 5, 10, 15, 20, 25 or 26.658, etc.

[0120] In some possible implementation manners, the lens 100 can further satisfy the relational expression: -8.5 ≤ R2 / EFL ≤ -0.15, where R2 refers to the radius of curvature of the object side surface of the lens closest to the object side in the lens 100, and EFL is the focal length of the lens 100.

[0121] Correspondingly, when the ratio of the radius of curvature of the object side surface of the lens closest to the object side in the lens 100 to the focal length of the lens 100 is between -8.5 and -0.15, it is possible to avoid the object side surface of the lens closest to the object side in the lens 100 from being too flat, which is beneficial to aberration correction. In addition, it is also possible to avoid the object side surface of the lens closest to the object side in the lens 100 from being too convex, which is beneficial to packaging, transportation or assembly.

[0122] There is no limitation on the specific ratio of R2 / EFL. Among them, the ratio of R2 / EFL can be -8.5, -8, -7, -6, -5, -3, -1, -0.69, -0.60, -0.50, -0.49, -0.45, -0.40, -0.35, -0.30, -0.25, -0.2 or -0.15, etc.

[0123] In some possible implementation manners, the lens 100 can further satisfy the relational expression: 25mm ≤ BFL ≤ 30mm, where BFL is the back focal length of the lens 100.

[0124] Correspondingly, when the back focal length of the lens 100 is between 25mm and 30mm, it is possible to avoid the optical path of the lens 100 from being too long or too short, and the application range of the lens 100 can be improved. Among them, if the optical path of the lens 100 is too long, it is not conducive to design. If the optical path of the lens 100 is too short, it is not conducive to the setting of the rear optical path.

[0125] There is no limitation on the specific value of BFL. Among them, the value of BFL can be 25mm, 25.5mm, 26mm, 26.5mm, 27mm, 27.5mm, 28mm, 28.5mm, 29mm, 29.5mm or 30mm, etc.

[0126] In some possible implementation manners, the first lens group 10 may further satisfy the relational expression: -18 mm ≤ EFL1 ≤ 9 mm, where EFL1 refers to the focal length of the first lens group 10.

[0127] Correspondingly, when the focal length of the first lens group 10 is between -18 mm and 9 mm, the imaging capability of the lens 100 can be further improved, and the clarity can be further enhanced. Additionally, the compactness of the lens 100 can also be improved.

[0128] There is no limitation on the specific value of EFL1. Among them, the value of EFL1 can be -18 mm, -17.5 mm, -17 mm, -16 mm, -15 mm, -13 mm, -10 mm, -5 mm, 1 mm, 5 mm, 7 mm, 8.5 mm, 9 mm, etc.

[0129] In some possible implementation manners, the second lens group 30 may further satisfy the relational expression: 12.58 mm ≤ EFL2 ≤ 15.98 mm, where EFL2 refers to the focal length of the second lens group 30.

[0130] Correspondingly, when the focal length of the second lens group 30 is between 12.58 mm and 15.98 mm, the imaging capability of the lens 100 can be further improved, and the clarity can be further enhanced. Additionally, the compactness of the lens 100 can also be improved. Moreover, the matching degree between the chief ray angle of the rear-end chip (such as a digital micromirror array) and the chief ray angle of the lens 100 can be improved to enhance the optical efficiency.

[0131] There is no limitation on the specific value of EFL2. Among them, the value of EFL2 can be 12.58 mm, 12.985 mm, 13 mm, 13.564 mm, 13.987 mm, 14 mm, 14.105 mm, 14.5 mm, 15 mm, 15.5 mm, 15.98 mm, etc.

[0132] In some possible implementation manners, along the direction from the image side to the object side, the first lens closest to the aperture 20 in the second lens group 30 may have a positive or negative optical power. For example Figure 2 as shown, the fourth lens 31 in the second lens group 30 may have a positive optical power. Of course, the fourth lens 31 may also have a negative optical power.

[0133] Correspondingly, when the first lens closest to the aperture 20 in the second lens group 30 has a positive or negative optical power, the imaging capability of the lens 100 can be further improved.

[0134] It should be noted that the first lens closest to the aperture 20 in the second lens group 30 may also have no optical power. Under the limitations that the three lenses closest to the image side in the first lens group 10 have a negative-positive-negative optical power structure and the second and third lenses closest to the aperture 20 in the second lens group 30 have positive optical power, the lens 100 can also have high definition and high reliability.

[0135] The lens 100 and the projection device 400 provided by the embodiments of the present application will be described in detail below with reference to specific embodiments.

[0136] Figure 3 It is a schematic structural diagram of the second projection device provided in Embodiment 1 of the present application.

[0137] Combined with Figure 3 It can be seen that the projection device 400 provided in Embodiment 1 may include a modulation unit 200, a cover glass 300, and a lens 100. Among them, the lens 100 includes a first lens group 10, an aperture 20, and a second lens group 30 arranged from the image side to the object side. Along the direction from the image side to the object side, the second lens group 30 is disposed between the aperture 20 and the modulation unit 200, and the cover glass 300 is disposed between the modulation unit 200 and the lens 100.

[0138] Combined with Figure 3 It can be seen that the first lens group 10 may include a first lens 11, a second lens 12, and a third lens 13 arranged in sequence from the image side to the object side. The first lens 11 is closest to the image side, and the third lens 13 is closest to the aperture 20. Among them, the first lens 11 has a negative optical power, and the focal length f1 of the first lens 11 = -25.72. The second lens 12 has a positive optical power, and the focal length f2 of the second lens 12 = 21.33. The third lens 13 has a negative optical power, and the focal length f3 of the third lens 13 = -9.66.

[0139] Combined with Figure 3 It can be seen that the second lens group 30 may include a fourth lens 31, a fifth lens 32, and a sixth lens 33 arranged in sequence from the image side to the object side. The fourth lens 31 is closest to the aperture 20, and the sixth lens 33 is closest to the modulation unit 200. Among them, the fourth lens 31 has a positive optical power, and the focal length f4 of the fourth lens 31 = 24.862. The fifth lens 32 has a positive optical power, and the focal length f5 of the fifth lens 32 = 38.19. The sixth lens 33 has a positive optical power, and the focal length f6 of the sixth lens 33 = 43.24.

[0140] The lens closest to the image side in the lens 100 is the first lens 11. The radius of curvature of the image side of the first lens 11 is 115.17 mm, which is greater than -94 mm and less than 367 mm, meeting the requirements. The ratio of the radius of curvature R1 of the image side of the first lens 11 to the focal length EFL of the lens 100 is R1 / EFL = 8.383, which is greater than -7 and less than 27, meeting the requirements. The focal length EFL1 of the first lens group 10 is -10.721 mm, which is greater than -18 mm and less than 9 mm, meeting the requirements.

[0141] The lens closest to the object side in the lens 100 is the sixth lens 33. The radius of curvature of the object side of the sixth lens 33 is -112.15 mm, which is greater than -113 mm and less than 30 mm, meeting the requirements. The ratio of the radius of curvature R2 of the object side of the sixth lens 33 to the focal length EFL of the lens 100 is R2 / EFL = -8.164, which is greater than -8.5 and less than -0.15, meeting the requirements. The focal length EFL2 of the second lens group 30 is 15.260 mm, which is greater than 12.58 mm and less than 15.98 mm, meeting the requirements.

[0142] In the direction from the image side to the object side, the distance between the object side of the sixth lens 33 and the modulation unit 200 is 27.4 mm, that is, the back focal length BFL of the lens 100 is 27.4 mm, which is greater than 25 mm and less than 30 mm, meeting the requirements.

[0143] The focal length EFL of the lens 100 is 13.738 mm, which is greater than 12.5 mm and less than 14.5 mm, meeting the requirements.

[0144] Table 1 shows the optical parameters of each optical element in the second projection device 400 provided in the first embodiment of the present application.

[0145]

[0146]

[0147] Among them, S1 is the image side of the first lens 11, S2 is the object side of the first lens 11, S3 is the image side of the second lens 12, S4 is the object side of the second lens 12, S5 is the image side of the third lens 13, S6 is the object side of the third lens 13, S7 is the aperture stop 20, S8 is the image side of the fourth lens 31, S9 is the object side of the fourth lens 31, S10 is the image side of the fifth lens 32, S11 is the object side of the fifth lens 32, S12 is the image side of the sixth lens 33, S13 is the object side of the sixth lens 33, S14 is the image side of the cover glass 300, S15 is the object side of the cover glass 300, S16 to S18 are the modulation unit 200, OBJ is the projection plane (object plane), and ImgH is the imaging plane.

[0148] Wherein, R is the radius of curvature at the corresponding position of the optical element (such as a lens or a cover glass 300, etc.) on the optical axis, TH is the surface thickness of the optical element in the optical axis direction, Nd is the refractive index of the d-line irradiated on each optical element, and Vd is the Abbe number of the optical element.

[0149] Table 2 shows Figure 3 the optical parameters of the lens 100 in

[0150] f1 (mm) -25.716 R1 / EFL 8.383 f2 (mm) 21.328 R2 / EFL -8.164 f3 (mm) -9.659 EFL1 -10.721 f4 (mm) 24.862 EFL2 15.260 f5 (mm) 38.190 EFL (mm) 13.738 f6 (mm) 43.242 BFL (mm) 27.400

[0151] Wherein, EFL is the focal length of the lens 100, EFL1 is the focal length of the first lens group 10, EFL2 is the focal length of the second lens group 30, BFL is the back focal length of the lens 100, R1 is the radius of curvature of the image side surface of the lens closest to the image side in the lens 100, R2 is the radius of curvature of the object side surface of the lens closest to the object side in the lens 100, f1 is the focal length of the first lens 11, f2 is the focal length of the second lens 12, f3 is the focal length of the third lens 13, f4 is the focal length of the fourth lens 31, f5 is the focal length of the fifth lens 32, and f6 is the focal length of the sixth lens 33.

[0152] Figure 4 is Figure 3 the spherical aberration diagram of the lens in Figure 4 In Figure 4 the vertical coordinate represents the normalized pupil coordinate, and the horizontal coordinate represents the aberration in the axial direction, with the unit of millimeter. In Figure 4 it can be seen that in this embodiment, the axial aberration is controlled within a very small range, obtaining better correction.

[0153] Figure 5 is Figure 3 the astigmatism field curvature diagram of the lens in Figure 6 is Figure 4 the distortion diagram of the lens in Figure 5 In Figure 6 S represents the field curvature value of the light with a wavelength of 550 nm in the meridional image plane, and T represents the field curvature value of the light with a wavelength of 550 nm in the sagittal image plane. In Figure 5 and Figure 6 it can be known that the lens 100 provided in this embodiment controls the field curvature and distortion within the corresponding ranges, and can meet the usage requirements.

[0154] Figure 7 This is a schematic structural diagram of the third projection device provided in the second embodiment of the present application.

[0155] Combined with Figure 7 It can be seen that the projection device 400 provided in the second embodiment may include a modulation unit 200, a cover glass 300, and a lens 100. Among them, the lens 100 includes a first lens group 10, a diaphragm 20, and a second lens group 30 arranged from the image side to the object side. Along the direction from the image side to the object side, the second lens group 30 is disposed between the diaphragm 20 and the modulation unit 200, and the cover glass 300 is disposed between the modulation unit 200 and the lens 100.

[0156] Combined with Figure 7 It can be seen that the first lens group 10 may include a first lens 11, a second lens 12, and a third lens 13 arranged in sequence from the image side to the object side. The first lens 11 is closest to the image side, and the third lens 13 is closest to the diaphragm 20. Among them, the first lens 11 has a negative focal power, and the focal length f1 of the first lens 11 = -25.99. The second lens 12 has a positive focal power, and the focal length f2 of the second lens 12 = 21.16. The third lens 13 has a negative focal power, and the focal length f3 of the third lens 13 = -9.52.

[0157] Combined with Figure 7 It can be seen that the second lens group 30 may include a fourth lens 31, a fifth lens 32, and a sixth lens 33 arranged in sequence from the image side to the object side. The fourth lens 31 is closest to the diaphragm 20, and the sixth lens 33 is closest to the modulation unit 200. Among them, the fourth lens 31 has a positive focal power, and the focal length f4 of the fourth lens 31 = 23.253. The fifth lens 32 has a positive focal power, and the focal length f5 of the fifth lens 32 = 38.216. The sixth lens 33 has a positive focal power, and the focal length f6 of the sixth lens 33 = 43.221.

[0158] The lens in the lens 100 closest to the image side is the first lens 11. The radius of curvature of the image side of the first lens 11 is 366.49 mm, which is greater than -94 mm and less than 367 mm, meeting the requirements. The ratio R1 / EFL of the radius of curvature R1 of the image side of the first lens 11 to the focal length EFL of the lens 100 = 26.260, which is greater than -7 and less than 27, meeting the requirements. The focal length EFL1 of the first lens group 10 = -10.432 mm, which is greater than -18 mm and less than 9 mm, meeting the requirements.

[0159] The lens closest to the object side in the lens 100 is the sixth lens 33. The curvature radius of the object side surface of the sixth lens 33 is -112.93 mm, which is greater than -113 mm and less than 30 mm, meeting the requirements. The ratio of the curvature radius R2 of the object side surface of the sixth lens 33 to the focal length EFL of the lens 100, R2 / EFL = -8.092, is greater than -8.5 and less than -0.15, meeting the requirements. The focal length EFL2 of the second lens group 30 is 15.218 mm, which is greater than 12.58 mm and less than 15.98 mm, meeting the requirements.

[0160] In the direction from the image side to the object side, the distance between the object side surface of the sixth lens 33 and the modulation unit 200 is 27.4 mm, that is, the back focal length BFL of the lens 100 is 27.4 mm, which is greater than 25 mm and less than 30 mm, meeting the requirements.

[0161] The focal length EFL of the lens 100 is 13.956 mm, which is greater than 12.5 mm and less than 14.5 mm, meeting the requirements.

[0162] Table 3 shows the optical parameters of each optical element in the third projection device 400 provided in the second embodiment of the present application.

[0163] Face number Surface type R (mm) TH (mm) Nd Vd OBJ Spherical surface Infinity 130.000 S1 Spherical surface 366.490 1.200 1.59 68.3 S2 Spherical surface 14.814 3.932 S3 Spherical surface 51.972 2.973 1.96 17.5 S4 Spherical surface -35.666 7.310 S5 Spherical surface -14.631 4.764 1.96 17.5 S6 Spherical surface 29.027 0.536 S7 Spherical surface Infinity 0.352 S8 Spherical surface -67.883 5.461 1.73 54.7 S9 Spherical surface -14.072 9.986 S10 Spherical surface -119.154 4.425 1.59 68.3 S11 Spherical surface -19.350 0.100 S12 Spherical surface 32.818 4.060 1.59 68.3 S13 Spherical surface -112.932 2.500 S14 Spherical surface Infinity 1.000 1.52 64.2 S15 Spherical surface Infinity 22.500 S16 Spherical surface Infinity 0.700 1.48 65 S17 Spherical surface Infinity 0.700 1.51 62 S18 Spherical surface Infinity 0.000 ImgH Spherical surface Infinity 0.000

[0164] Among them, S1 is the image side surface of the first lens 11, S2 is the object side surface of the first lens 11, S3 is the image side surface of the second lens 12, S4 is the object side surface of the second lens 12, S5 is the image side surface of the third lens 13, S6 is the object side surface of the third lens 13, S7 is the aperture stop 20, S8 is the image side surface of the fourth lens 31, S9 is the object side surface of the fourth lens 31, S10 is the image side surface of the fifth lens 32, S11 is the object side surface of the fifth lens 32, S12 is the image side surface of the sixth lens 33, S13 is the object side surface of the sixth lens 33, S14 is the image side surface of the cover glass 300, S15 is the object side surface of the cover glass 300, S16 to S18 are the modulation unit 200, OBJ is the projection surface (object surface), and ImgH is the imaging surface.

[0165] Among them, R is the curvature radius of the optical element (such as a lens or the cover glass 300, etc.) at the corresponding position on the optical axis, TH is the surface thickness of the optical element in the direction 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.

[0166] Table 4 shows Figure 7 the optical parameters of the lens 100 in

[0167] f1 (mm) -25.994 R1 / EFL 26.260 f2 (mm) 22.164 R2 / EFL -8.092 f3 (mm) -9.512 EFL1 -10.432 f4 (mm) 23.253 EFL2 15.218 f5 (mm) 38.216 EFL (mm) 13.956 f6 (mm) 43.211 BFL (mm) 27.400

[0168] Wherein, EFL is the focal length of the lens 100, EFL1 is the focal length of the first lens group 10, EFL2 is the focal length of the second lens group 30, BFL is the back focal length of the lens 100, R1 is the radius of curvature of the image side surface of the lens closest to the image side in the lens 100, R2 is the radius of curvature of the object side surface of the lens closest to the object side in the lens 100, f1 is the focal length of the first lens 11, f2 is the focal length of the second lens 12, f3 is the focal length of the third lens 13, f4 is the focal length of the fourth lens 31, f5 is the focal length of the fifth lens 32, and f6 is the focal length of the sixth lens 33.

[0169] Figure 8 is Figure 7 the spherical aberration diagram of the lens in. In Figure 8 , the ordinate represents the normalized pupil coordinate, and the abscissa represents the aberration in the axial direction, with the unit of millimeter. In Figure 8 , the three curves respectively correspond to the axial aberration curves of the light with a wavelength of 625 nm, the light with a wavelength of 550 nm, and the light with a wavelength of 455 nm passing through the lens 100 of this embodiment. From Figure 8 , it can be seen that in this embodiment, the axial aberration is controlled within a very small range, and good correction is obtained.

[0170] Figure 9 is Figure 7 the astigmatism field curvature diagram of the lens in Figure 10 is Figure 7 the distortion diagram of the lens in. In Figure 9 , S represents the field curvature value of the light with a wavelength of 550 nm in the meridional image plane, and T represents the field curvature value of the light with a wavelength of 550 nm in the sagittal image plane. In Figure 10 , the solid line represents the distortion value of the light with a central wavelength of 550 nm passing through the lens 100 of this embodiment. Combining Figure 9 and Figure 10 , it can be known that the lens 100 provided in this embodiment controls the field curvature and distortion within the corresponding ranges and can meet the usage requirements.

[0171] Figure 11 is the structural schematic diagram of the fourth projection device provided in Embodiment III of the present application.

[0172] Combining Figure 11 , it can be known that the projection device 400 provided in Embodiment III may include a modulation unit 200, a cover glass 300, and a lens 100. Among them, the lens 100 includes a first lens group 10, a diaphragm 20, and a second lens group 30 arranged from the image side to the object side. Along the direction from the image side to the object side, the second lens group 30 is disposed between the diaphragm 20 and the modulation unit 200, and the cover glass 300 is disposed between the modulation unit 200 and the lens 100.

[0173] Combining Figure 11It can be known that the first lens group 10 may include a first lens 11, a second lens 12, and a third lens 13 arranged in sequence from the image side to the object side. The first lens 11 is closest to the image side, and the third lens 13 is closest to the aperture stop 20. Among them, the first lens 11 has a negative focal power, and the focal length f1 of the first lens 11 is -29.537. The second lens 12 has a positive focal power, and the focal length f2 of the second lens 12 is 29.005. The third lens 13 has a negative focal power, and the focal length f3 of the third lens 13 is -10.332.

[0174] Combined with Figure 11 It can be known that the second lens group 30 may include a fourth lens 31, a fifth lens 32, and a sixth lens 33 arranged in sequence from the image side to the object side. The fourth lens 31 is closest to the aperture stop 20, and the sixth lens 33 is closest to the modulation unit 200. Among them, the fourth lens 31 has a positive focal power, and the focal length f4 of the fourth lens 31 is 22.265. The fifth lens 32 has a positive focal power, and the focal length f5 of the fifth lens 32 is 38.6. The sixth lens 33 has a positive focal power, and the focal length f6 of the sixth lens 33 is 39.723.

[0175] The lens closest to the image side in the lens 100 is the first lens 11. The radius of curvature of the image side surface of the first lens 11 is -62.971 mm, which is greater than -94 mm and less than 367 mm, meeting the requirements. The ratio R1 / EFL of the radius of curvature R1 of the image side surface of the first lens 11 to the focal length EFL of the lens 100 is -4.585, which is greater than -7 and less than 27, meeting the requirements. The focal length EFL1 of the first lens group 10 is -10.083 mm, which is greater than -18 mm and less than 9 mm, meeting the requirements.

[0176] The lens closest to the object side in the lens 100 is the sixth lens 33. The radius of curvature of the object side surface of the sixth lens 33 is -55.467 mm, which is greater than -113 mm and less than 30 mm, meeting the requirements. The ratio R2 / EFL of the radius of curvature R2 of the object side surface of the sixth lens 33 to the focal length EFL of the lens 100 is -4.039, which is greater than -8.5 and less than -0.15, meeting the requirements. The focal length EFL2 of the second lens group 30 is 14.232 mm, which is greater than 12.58 mm and less than 15.98 mm, meeting the requirements.

[0177] Along the direction from the image side to the object side, the distance between the object side surface of the sixth lens 33 and the modulation unit 200 is 27.4 mm, that is, the back focal length BFL of the lens 100 is 27.4 mm, which is greater than 25 mm and less than 30 mm, meeting the requirements.

[0178] The focal length EFL of the lens 100 is 13.734 mm, which is greater than 12.5 mm and less than 14.5 mm, meeting the requirements.

[0179] Table 5 shows the optical parameters of each optical element in the fourth projection device 400 provided in the third embodiment of the present application.

[0180] Face number Surface type R (mm) TH (mm) Nd Vd OBJ Spherical surface Infinity 130.000 S1 Spherical surface -62.971 1.200 1.59 68.3 S2 Spherical surface 24.532 3.649 S3 Spherical surface 126.181 2.932 1.96 17.5 S4 Spherical surface -35.818 11.604 S5 Spherical surface -13.724 1.200 1.96 17.5 S6 Spherical surface 38.828 0.423 S7 Spherical surface Infinity 0.330 S8 Spherical surface -76.365 6.000 1.73 54.7 S9 Spherical surface -13.877 6.232 S10 Spherical surface -39.170 7.000 1.59 68.3 S11 Spherical surface -15.437 0.100 S12 Spherical surface 39.918 4.430 1.59 68.3 S13 Spherical surface -55.467 2.500 S14 Spherical surface Infinity 1.000 1.52 64.2 S15 Spherical surface Infinity 22.500 S16 Spherical surface Infinity 0.700 1.48 65 S17 Spherical surface Infinity 0.700 1.51 62 S18 Spherical surface Infinity 0.000 ImgH Spherical surface Infinity 0.000

[0181] Among them, S1 is the image side of the first lens 11, S2 is the object side of the first lens 11, S3 is the image side of the second lens 12, S4 is the object side of the second lens 12, S5 is the image side of the third lens 13, S6 is the object side of the third lens 13, S7 is the aperture stop 20, S8 is the image side of the fourth lens 31, S9 is the object side of the fourth lens 31, S10 is the image side of the fifth lens 32, S11 is the object side of the fifth lens 32, S12 is the image side of the sixth lens 33, S13 is the object side of the sixth lens 33, S14 is the image side of the cover glass 300, S15 is the object side of the cover glass 300, S16 to S18 are the modulation unit 200, OBJ is the projection surface (object surface), and ImgH is the imaging surface.

[0182] Among them, R is the radius of curvature of the optical element (such as a lens or the cover glass 300, etc.) at the corresponding position on the optical axis, TH is the surface thickness of the optical element in the direction of the optical axis, Nd is the refractive index of the d-line irradiating each optical element, and Vd is the Abbe number of the optical element.

[0183] Table 6 shows Figure 11 the optical parameters of the lens 100 in

[0184]

[0185]

[0186] Among them, EFL is the focal length of the lens 100, EFL1 is the focal length of the first lens group 10, EFL2 is the focal length of the second lens group 30, BFL is the back focal length of the lens 100, R1 is the radius of curvature of the image side of the lens closest to the image side in the lens 100, R2 is the radius of curvature of the object side of the lens closest to the object side in the lens 100, f1 is the focal length of the first lens 11, f2 is the focal length of the second lens 12, f3 is the focal length of the third lens 13, f4 is the focal length of the fourth lens 31, f5 is the focal length of the fifth lens 32, and f6 is the focal length of the sixth lens 33.

[0187] Figure 12 is Figure 11 the spherical aberration diagram of the lens in Figure 12 In Figure 12Among them, the three curves respectively 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 lens 100 of this embodiment. From Figure 12 It can be seen that in this embodiment, the axial aberration is controlled within a very small range, and good correction is obtained.

[0188] Figure 13 For Figure 11 the astigmatism field curvature diagram of the lens in Figure 14 For Figure 11 the distortion diagram of the lens in Figure 13 In Figure 14 S represents the field curvature value of light with a wavelength of 550 nm in the meridional image plane, and T represents the field curvature value of light with a wavelength of 550 nm in the sagittal image plane. In Figure 13 and Figure 14 it can be known that the lens 100 provided in this embodiment controls the field curvature and distortion within the corresponding ranges and can meet the usage requirements.

[0189] Figure 15 This is a schematic structural diagram of the fifth projection device provided in Embodiment 4 of the present application.

[0190] Combined with Figure 15 it can be known that the projection device 400 provided in Embodiment 4 may include a modulation unit 200, a cover glass 300, and a lens 100. Among them, the lens 100 includes a first lens group 10, a diaphragm 20, and a second lens group 30 arranged from the image side to the object side. Along the direction from the image side to the object side, the second lens group 30 is disposed between the diaphragm 20 and the modulation unit 200, and the cover glass 300 is disposed between the modulation unit 200 and the lens 100.

[0191] Combined with Figure 15 it can be known that the first lens group 10 may include a first lens 11, a second lens 12, and a third lens 13 arranged in sequence from the image side to the object side. The first lens 11 is closest to the image side, and the third lens 13 is closest to the diaphragm 20. Among them, the first lens 11 has a negative optical power, and the focal length f1 of the first lens 11 = -31.088. The second lens 12 has a positive optical power, and the focal length f2 of the second lens 12 = 29.916. The third lens 13 has a negative optical power, and the focal length f3 of the third lens 13 = -10.235.

[0192] Combined with Figure 15It can be known that the second lens group 30 may include a fourth lens 31, a fifth lens 32, and a sixth lens 33 arranged in sequence from the image side to the object side. The fourth lens 31 is closest to the aperture stop 20, and the sixth lens 33 is closest to the modulation unit 200. Among them, the fourth lens 31 has a positive optical power, and the focal length f4 of the fourth lens 31 is 24.836. The fifth lens 32 has a positive optical power, and the focal length f5 of the fifth lens 32 is 35.738. The sixth lens 33 has a positive optical power, and the focal length f6 of the sixth lens 33 is 36.589.

[0193] The lens closest to the image side in the lens 100 is the first lens 11. The radius of curvature of the image side surface of the first lens 11 is -85.63 mm, which is greater than -94 mm and less than 367 mm, meeting the requirements. The ratio R1 / EFL of the radius of curvature R1 of the image side surface of the first lens 11 to the focal length EFL of the lens 100 is -6.243, which is greater than -7 and less than 27, meeting the requirements. The focal length EFL1 of the first lens group 10 is -10.196 mm, which is greater than -18 mm and less than 9 mm, meeting the requirements.

[0194] The lens closest to the object side in the lens 100 is the sixth lens 33. The radius of curvature of the object side surface of the sixth lens 33 is -49.33 mm, which is greater than -113 mm and less than 30 mm, meeting the requirements. The ratio R2 / EFL of the radius of curvature R2 of the object side surface of the sixth lens 33 to the focal length EFL of the lens 100 is -3.596, which is greater than -8.5 and less than -0.15, meeting the requirements. The focal length EFL2 of the second lens group 30 is 13.950 mm, which is greater than 12.58 mm and less than 15.98 mm, meeting the requirements.

[0195] Along the direction from the image side to the object side, the distance between the object side surface of the sixth lens 33 and the modulation unit 200 is 27.4 mm, that is, the back focal length BFL of the lens 100 is 27.4 mm, which is greater than 25 mm and less than 30 mm, meeting the requirements.

[0196] The focal length EFL of the lens 100 is 13.716 mm, which is greater than 12.5 mm and less than 14.5 mm, meeting the requirements.

[0197] Table 7 shows the optical parameters of each optical element in the fifth projection device 400 provided in the fourth embodiment of the present application.

[0198]

[0199]

[0200] Among them, S1 is the image side of the first lens 11, S2 is the object side of the first lens 11, S3 is the image side of the second lens 12, S4 is the object side of the second lens 12, S5 is the image side of the third lens 13, S6 is the object side of the third lens 13, S7 is the aperture stop 20, S8 is the image side of the fourth lens 31, S9 is the object side of the fourth lens 31, S10 is the image side of the fifth lens 32, S11 is the object side of the fifth lens 32, S12 is the image side of the sixth lens 33, S13 is the object side of the sixth lens 33, S14 is the image side of the cover glass 300, S15 is the object side of the cover glass 300, S16 to S18 are the modulation units 200, OBJ is the projection plane (object plane), and ImgH is the imaging plane.

[0201] Among them, R is the radius of curvature of the optical element (such as a lens or the cover glass 300, etc.) at the corresponding position on the optical axis, TH is the surface thickness of the optical element in the optical axis direction, Nd is the refractive index of the d-line irradiating each optical element, and Vd is the Abbe number of the optical element.

[0202] Table 8 shows Figure 15 the optical parameters of the lens 100 in

[0203] f1 (mm) -31.088 R1 / EFL -6.243 f2 (mm) 29.916 R2 / EFL -3.596 f3 (mm) -10.235 EFL1 -10.196 f4 (mm) 24.836 EFL2 13.950 f5 (mm) 35.738 EFL (mm) 13.716 f6 (mm) 36.589 BFL (mm) 27.400

[0204] Among them, EFL is the focal length of the lens 100, EFL1 is the focal length of the first lens group 10, EFL2 is the focal length of the second lens group 30, BFL is the back focal length of the lens 100, R1 is the radius of curvature of the image side of the lens closest to the image side in the lens 100, R2 is the radius of curvature of the object side of the lens closest to the object side in the lens 100, f1 is the focal length of the first lens 11, f2 is the focal length of the second lens 12, f3 is the focal length of the third lens 13, f4 is the focal length of the fourth lens 31, f5 is the focal length of the fifth lens 32, and f6 is the focal length of the sixth lens 33.

[0205] Figure 16 is Figure 15 the spherical aberration diagram of the lens in Figure 16 In Figure 16 the vertical coordinate represents the normalized pupil coordinate, and the horizontal coordinate represents the aberration in the axial direction, with the unit of millimeter. In Figure 16 it can be seen that in this embodiment, the axial aberration is controlled within a very small range, achieving better correction.

[0206] Figure 17 is Figure 15 the astigmatism field curvature diagram of the lens in Figure 18 isFigure 15 The distortion diagram of the lens in Figure 17 , S represents the field curvature value of light with a wavelength of 550 nm in the meridional image plane, and T represents the field curvature value of light with a wavelength of 550 nm in the sagittal image plane. In Figure 18 , the solid line represents the distortion value of light with a central wavelength of 550 nm passing through the lens 100 of this embodiment. Combining Figure 17 and Figure 18 , it can be seen that the lens 100 provided in this embodiment controls the field curvature and distortion within the corresponding ranges and can meet the usage requirements.

[0207] Figure 19 FIG. 13 is a schematic structural diagram of a sixth projection device provided in Embodiment 5 of the present application.

[0208] Combining Figure 19 , it can be seen that the projection device 400 provided in Embodiment 5 may include a modulation unit 200, a cover glass 300, and a lens 100. Among them, the lens 100 includes a first lens group 10, a diaphragm 20, and a second lens group 30 arranged from the image side to the object side. Along the direction from the image side to the object side, the second lens group 30 is disposed between the diaphragm 20 and the modulation unit 200, and the cover glass 300 is disposed between the modulation unit 200 and the lens 100.

[0209] Combining Figure 19 , it can be seen that the first lens group 10 may include a first lens 11, a second lens 12, and a third lens 13 arranged in sequence from the image side to the object side. The first lens 11 is closest to the image side, and the third lens 13 is closest to the diaphragm 20. Among them, the first lens 11 has a negative optical power, and the focal length f1 of the first lens 11 = -23.94. The second lens 12 has a positive optical power, and the focal length f2 of the second lens 12 = 19.70. The third lens 13 has a negative optical power, and the focal length f3 of the third lens 13 = -13.24.

[0210] Combining Figure 19 , it can be seen that the second lens group 30 may include a fourth lens 31, a fifth lens 32, and a sixth lens 33 arranged in sequence from the image side to the object side. The fourth lens 31 is closest to the diaphragm 20, and the sixth lens 33 is closest to the modulation unit 200. Among them, the fourth lens 31 has a positive optical power, and the focal length f4 of the fourth lens 31 = 269.41. The fifth lens 32 has a positive optical power, and the focal length f5 of the fifth lens 32 = 30.72. The sixth lens 33 has a positive optical power, and the focal length f6 of the sixth lens 33 = 37.63.

[0211] The lens closest to the image side in the lens 100 is the first lens 11. The radius of curvature of the image side of the first lens 11 is -93.74 mm, which is greater than -94 mm and less than 367 mm, meeting the requirements. The ratio of the radius of curvature R1 of the image side of the first lens 11 to the focal length EFL of the lens 100, R1 / EFL = -6.853, is greater than -7 and less than 27, meeting the requirements. The focal length EFL1 of the first lens group 10 is -17.138 mm, which is greater than -18 mm and less than 9 mm, meeting the requirements.

[0212] The lens closest to the object side in the lens 100 is the sixth lens 33. The radius of curvature of the object side of the sixth lens 33 is -32.42 mm, which is greater than -113 mm and less than 30 mm, meeting the requirements. The ratio of the radius of curvature R2 of the object side of the sixth lens 33 to the focal length EFL of the lens 100, R2 / EFL = -2.370, is greater than -8.5 and less than -0.15, meeting the requirements. The focal length EFL2 of the second lens group 30 is 15.109 mm, which is greater than 12.58 mm and less than 15.98 mm, meeting the requirements.

[0213] In the direction from the image side to the object side, the distance between the object side of the sixth lens 33 and the modulation unit 200 is 27.4 mm, that is, the back focal length BFL of the lens 100 is 27.4 mm, which is greater than 25 mm and less than 30 mm, meeting the requirements.

[0214] The focal length EFL of the lens 100 is 13.678 mm, which is greater than 12.5 mm and less than 14.5 mm, meeting the requirements.

[0215] Table 9 shows the optical parameters of each optical element in the sixth projection device 400 provided in the fifth embodiment of the present application.

[0216]

[0217]

[0218] Among them, S1 is the image side of the first lens 11, S2 is the object side of the first lens 11, S3 is the image side of the second lens 12, S4 is the object side of the second lens 12, S5 is the image side of the third lens 13, S6 is the object side of the third lens 13, S7 is the aperture stop 20, S8 is the image side of the fourth lens 31, S9 is the object side of the fourth lens 31, S10 is the image side of the fifth lens 32, S11 is the object side of the fifth lens 32, S12 is the image side of the sixth lens 33, S13 is the object side of the sixth lens 33, S14 is the image side of the cover glass 300, S15 is the object side of the cover glass 300, S16 to S18 are the modulation unit 200, OBJ is the projection plane (object plane), and ImgH is the imaging plane.

[0219] Wherein, R is the radius of curvature at the position corresponding to the optical axis of the optical element (such as a lens or a cover glass 300, etc.), TH is the surface thickness of the optical element in the direction of the optical axis, Nd is the refractive index of the d-line irradiating each optical element, and Vd is the Abbe number of the optical element.

[0220] Table 10 shows Figure 19 the optical parameters of the lens 100 in

[0221] f1 (mm) -23.935 R1 / EFL -6.853 f2 (mm) 19.694 R2 / EFL -2.370 f3 (mm) -13.244 EFL1 -17.138 f4 (mm) 269.411 EFL2 15.109 f5 (mm) 30.718 EFL (mm) 13.678 f6 (mm) 37.632 BFL (mm) 27.400

[0222] Wherein, EFL is the focal length of the lens 100, EFL1 is the focal length of the first lens group 10, EFL2 is the focal length of the second lens group 30, BFL is the back focal length of the lens 100, R1 is the radius of curvature of the image side surface of the lens closest to the image side in the lens 100, R2 is the radius of curvature of the object side surface of the lens closest to the object side in the lens 100, f1 is the focal length of the first lens 11, f2 is the focal length of the second lens 12, f3 is the focal length of the third lens 13, f4 is the focal length of the fourth lens 31, f5 is the focal length of the fifth lens 32, and f6 is the focal length of the sixth lens 33.

[0223] Figure 20 is Figure 19 the spherical aberration diagram of the lens in Figure 20 . In Figure 20 , the ordinate represents the normalized pupil coordinate, and the abscissa represents the aberration in the axial direction, with the unit of millimeter. In Figure 20 , the three curves respectively correspond to the axial aberration curves of the light with a wavelength of 625 nm, the light with a wavelength of 550 nm, and the light with a wavelength of 455 nm passing through the lens 100 of this embodiment. It can be seen from

[0224] Figure 21 that in this embodiment, the axial aberration is controlled within a very small range, and good correction is obtained. Figure 19 is the astigmatism field curvature diagram of the lens in Figure 22 is Figure 19 the distortion diagram of the lens in Figure 21 . In Figure 22 , S represents the field curvature value of the light with a wavelength of 550 nm in the meridional image plane, and T represents the field curvature value of the light with a wavelength of 550 nm in the sagittal image plane. In Figure 21 and Figure 22 , it can be known that the lens 100 provided in this embodiment controls the field curvature and distortion within the corresponding ranges and can meet the usage requirements.

[0225] In the description of the embodiments of the present application, it should be noted that unless otherwise clearly specified and limited, the terms "installation", "connection", and "coupling" should be understood in a broad sense. For example, it may be a fixed connection, or an indirect connection through an intermediate medium, or it may be the internal communication between two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to specific circumstances.

[0226] The device or component referred to in the embodiments of the present application or implied must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present application. In the description of the embodiments of the present application, the meaning of "a plurality" is two or more, unless otherwise specifically and precisely defined.

[0227] The terms "first", "second", "third", "fourth", etc. (if any) in the description and claims of the embodiments of the present application and the above-mentioned drawings are used to distinguish similar objects and do not necessarily describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products, or devices.

[0228] The term "a plurality" herein refers to two or more. The term "and / or" herein merely describes the association relationship of associated objects and indicates that three relationships may exist. For example, A and / or B may represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " herein generally represents an "or" relationship between the associated objects before and after; in a formula, the character " / " represents a "division" relationship between the associated objects before and after.

[0229] It can be understood that the various numerical numbers involved in the embodiments of the present application are only for the convenience of description and do not limit the scope of the embodiments of the present application.

[0230] It can be understood that in the embodiments of the present application, the magnitude of the serial numbers of the above processes does not mean the order of execution. The order of execution of each process should be determined by its function and internal logic and should not constitute any limitation on the implementation process of the embodiments of the present application.

Claims

1. A lens, characterized in that, it comprises a first lens group, a diaphragm, and a second lens group arranged from the image side to the object side; the first lens group comprises at least three lenses. Along the direction from the image side to the object side, the first lens closest to the image side in the first lens group has a negative focal power, the second lens has a positive focal power, and the third lens has a negative focal power; the second lens group comprises at least three lenses. Along the direction from the image side to the object side, the second lens closest to the diaphragm in the second lens group has a positive focal power, and the third lens has a positive focal power.

2. The lens according to claim 1, characterized in that, the lens satisfies the relation: 100mm ≤ L ≤ 150mm, where L is the distance between the image side surface of the lens closest to the image side in the lens and the projection image plane.

3. The lens according to claim 1 or 2, characterized in that, the lens satisfies the relation: 12.5mm ≤ EFL ≤ 14.5mm, where EFL is the focal length of the lens.

4. The lens according to any one of claims 1 to 3, characterized in that, the lens satisfies the relation: -94mm ≤ R1 ≤ 367mm, where R1 refers to the curvature radius of the image side surface of the lens closest to the image side in the lens.

5. The lens according to any one of claims 1 to 4, characterized in that, the lens satisfies the relation: -113mm ≤ R2 ≤ 30mm, where R2 refers to the curvature radius of the object side surface of the lens closest to the object side in the lens.

6. The lens according to any one of claims 1 to 5, characterized in that, the lens satisfies the relation: -7 ≤ R1 / EFL ≤ 27, where R1 refers to the curvature radius of the image side surface of the lens closest to the image side in the lens, and EFL is the focal length of the lens.

7. The lens according to any one of claims 1 to 6, characterized in that, the lens satisfies the relation: -8.5 ≤ R2 / EFL ≤ -0.15, where R2 refers to the curvature radius of the object side surface of the lens closest to the object side in the lens, and EFL is the focal length of the lens.

8. The lens according to any one of claims 1 to 7, characterized in that, the lens satisfies the relation: 25mm ≤ BFL ≤ 30mm, where BFL is the back focal length of the lens.

9. The lens according to any one of claims 1 to 8, characterized in that, the first lens group satisfies the relation: -18mm ≤ EFL1 ≤ 9mm, where EFL1 refers to the focal length of the first lens group.

10. The lens according to any one of claims 1 to 9, characterized in that, the second lens group satisfies the relation: 12.58mm ≤ EFL2 ≤ 15.98mm, where EFL2 refers to the focal length of the second lens group.

11. The lens according to any one of claims 1 to 10, characterized in that, In the direction from the image side to the object side, the first lens closest to the aperture in the second lens group has a positive or negative optical power.

12. The lens according to any one of claims 1 to 11, wherein, the first lens group includes a first lens with a negative optical power, a second lens with a positive optical power, and a third lens with a negative optical power arranged from the image side to the object side. The first lens is closest to the image side, and the third lens is closest to the aperture; the second lens group includes a fourth lens, a fifth lens with a positive optical power, and a sixth lens with a positive optical power arranged from the image side to the object side. The fourth lens is closest to the aperture, and the sixth lens is closest to the object side.

13. A projection device, wherein, it includes a display unit and the lens according to any one of claims 1 to 12, and the second lens group of the lens is close to the display unit; the display unit is configured to emit image light to the lens.

14. A display device, wherein, it includes an imaging module and the projection device according to claim 13; the imaging module is configured to generate a target image based on the image light emitted by the projection device.

15. A vehicle, wherein, it includes the display device according to claim 14.

16. The vehicle according to claim 15, wherein, the display device is installed in the instrument panel of the vehicle.

17. The vehicle according to claim 15 or 16, the vehicle further includes a windshield, the image light emitted by the display device is incident on the windshield, and the windshield reflects the image light to the human eye.

Images