Lens, projection apparatus, vehicle lamp apparatus, and vehicle

Abstract

Embodiments of the present application belong to the technical field of optics, and provide a lens, a projection apparatus, a vehicle lamp apparatus, and a vehicle. The lens comprises a lens group and a diaphragm. The lens group comprises at least five lenses arranged from an image side to an object side, at least five lenses in the lens group having focal power, and at least one lens in the lens group having negative focal power. The diaphragm comprises a first side and a second side that are disposed opposite one another in the direction from the image side to the object side, and at least one of the first side and the second side is provided with a lens. When the lens is provided on the first side, the lens located on the first side and closest to the diaphragm has negative focal power; and / or, when the lens is provided on the second side, the lens located on the second side and closest to the diaphragm has negative focal power. In this way, the lens can cooperate with a direct display chip such as a micro light-emitting diode display chip to form a small-sized projection apparatus, thereby reducing the size of the vehicle lamp apparatus.

Description

Lens, projection device, vehicle lamp device and vehicle

[0001] The present application claims priority to the Chinese patent application No. 202410893097.7, filed on July 03, 2024, and entitled "Lens, projection device, vehicle lamp device and vehicle", the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0002] Embodiments of the present application relate to the field of optical technology, in particular to a lens, a projection device, a vehicle lamp device and a vehicle. BACKGROUND

[0003] With the development of intelligent vehicle technology, it is required that the vehicle-mounted headlamp has a traditional lighting function and a projectable pattern to meet more and more needs of welcoming, information interaction, automatic driving and the like. In the related art, the vehicle lamp device includes a lens, a modulating device, a light source and a curved mirror. The curved mirror is configured to reflect a light beam emitted by the light source to the modulating device. The modulating device is a liquid crystal on silicon (LCOS). The modulating device modulates an imaging light beam according to the light beam from the curved mirror and emits the imaging light beam to the lens. However, in order to meet the arrangement requirements of the modulating device, the light source and the curved mirror and the like, the back focal length of the lens is relatively long, which leads to a large volume of the vehicle lamp device, thereby increasing the difficulty of arranging the vehicle lamp device in the vehicle. SUMMARY

[0004] Embodiments of the present application provide a lens, a projection device, a vehicle lamp device and a vehicle. The lens has a small back focal length, can be matched with a direct display chip such as a micro light emitting diode display chip to form a projection device with a small volume, thereby reducing the volume of the vehicle lamp device, and further reducing the difficulty of arranging the vehicle lamp device in the vehicle.

[0005] A first aspect of the present application provides a lens. The lens includes a lens group and a diaphragm. The lens group includes at least five lenses arranged from an image side to an object side. The number of lenses with optical power in the lens group is at least five. The number of lenses with negative optical power in the lens group is at least one. The diaphragm includes a first side and a second side oppositely arranged along a direction from the image side to the object side. The first side is close to the image side, and the second side is close to the object side. At least one of the first side and the second side is provided with a lens. When the first side is provided with a lens, the lens located on the first side and closest to the diaphragm has negative optical power. And / or, when the second side is provided with a lens, the lens located on the second side and closest to the diaphragm has negative optical power.

[0006] The rear focal length of the lens provided by the embodiment of the present application is small, so that the lens can be matched with a direct display chip such as a micro light emitting diode display chip to form a projection device with small volume. The projection device is applied to a vehicle lamp device, so that the volume of the vehicle lamp device can be reduced, and the difficulty of arranging the vehicle lamp device in a vehicle is reduced. In addition, the lens can have the characteristics of a large aperture and a large field of view, the imaging range of the lens can be increased, the lens can be matched with a direct display chip with a large target surface, for example, a direct display chip with a million pixels, that is, the large target surface design of the lens can be realized, the increase of the light emitting area is beneficial, so that the light emitting power of the projection device can be improved, and the brightness of the projection device can be improved. In addition, the optical performance of the lens can be improved, so that the imaging quality is improved, and the distortion is reduced.

[0007] In a possible implementation, the lens satisfies the relationship: 4.5mm < BFL < 10mm, where BFL is the rear focal length of the lens.

[0008] In this way, by controlling the rear focal length of the lens to be between 4.5mm and 10mm, the distance between the lens and the direct display chip such as the micro light emitting diode display chip can be further reduced, and the volume of the projection device can be further reduced. In addition, the lens can also have the characteristics of a large aperture and a large field of view.

[0009] In a possible implementation, the lens satisfies the relationship: 30.02mm < R1 < 100mm, where R1 is the radius of curvature of the image side surface of the lens closest to the image side in the lens group.

[0010] In this way, by making the lens satisfy the relationship: 30.02mm < R1 < 100mm, the manufacturing difficulty of the lens closest to the image side in the lens group can be reduced under the premise of realizing a large aperture and a large field of view at the same time, the yield is improved, and the economy is improved. In addition, the correction of aberration can be facilitated, and the optical performance of the lens is improved. In addition, the image side surface of the lens closest to the image side can be prevented from being too protruding or too flat, and the optical performance and the vehicle lamp modeling of the lens are effectively balanced.

[0011] In a possible implementation, the lens satisfies the relationship: 15mm < R2 < 30mm, where R2 is the radius of curvature of the object side surface of the lens closest to the object side in the lens group.

[0012] In this way, by making the lens satisfy the relationship: 15mm < R2 < 30mm, the manufacturing difficulty of the lens closest to the object side in the lens group can be reduced under the premise of realizing a large aperture and a large field of view at the same time, the yield is improved, and the economy is improved. In addition, the object side surface of the lens closest to the object side can be prevented from being too protruding or too concave, and the optical performance and the vehicle lamp modeling of the lens are effectively balanced.

[0013] In a possible implementation, the first side and the second side are each provided with a lens.

[0014] In this way, the diaphragm is arranged between the lens closest to the image side in the lens group and the lens closest to the object side in the lens group, which can further reduce the volume of the lens and improve the economy of the lens.

[0015] In a possible implementation, at least one lens in the lens group is an aspherical lens with optical power.

[0016] In this way, the aspherical lens capable of correcting aberration is arranged in the lens group, which can further improve the optical performance of the lens and improve the imaging quality.

[0017] In a possible implementation, all lenses with optical power in the lens group are spherical lenses.

[0018] In this way, while the lens has the characteristics of a large aperture and a large field of view, the manufacturing difficulty of each lens can be reduced, thereby reducing the cost of the lens and further improving the economy of the lens.

[0019] In a possible implementation, the number of lenses with negative optical power in the lens group is one.

[0020] In this way, while the lens has the characteristics of a large aperture and a large field of view, the influence of the lens with negative optical power on the optical power of the lens can be reduced, thereby further improving the comprehensive performance of the lens.

[0021] The second aspect of the present application provides a projection device, which comprises a display unit and the lens according to any one of the first aspect. The display surface of the display unit is opposite to the lens closest to the object side in the lens, and the display unit is configured to form a display image and transmit the display image to the lens through the display surface.

[0022] Since the lens has a small back focal length and a large target surface design, the lens can be matched with a display unit with at least a million pixels, which not only can reduce the volume of the projection device, but also can improve the brightness of the projection device. In addition, the structure of the projection device can be simplified, and the performance of the projection device can be improved.

[0023] In a possible implementation, the display unit is a micro light-emitting diode display chip, a sub-millimeter light-emitting diode display chip, or a thin film field effect transistor display chip.

[0024] In this way, the display unit adopts the display chip integrated with the array light source of the micro light-emitting diode, the sub-millimeter light-emitting diode, etc., which simplifies the structure of the projection device and can also reduce the volume of the projection device.

[0025] The third aspect of the present application provides a vehicle lamp device, which comprises a housing and the projection device according to any one of the second aspect, and at least part of the projection device is arranged inside the housing.

[0026] The fourth aspect of the present application provides a vehicle, which comprises the vehicle lamp device according to the third aspect. BRIEF DESCRIPTION OF DRAWINGS

[0027] Fig. 1 is a structural schematic diagram of a vehicle lamp device provided in the related art;

[0028] Fig. 2 is a structural schematic diagram of a vehicle lamp device provided in an embodiment of the present application;

[0029] Fig. 3 is a structural schematic diagram of a lens provided in an embodiment of the present application;

[0030] Fig. 4 is a structural schematic diagram of a projection device provided in an embodiment of the present application;

[0031] Fig. 5 is a spherical aberration diagram of the lens in Fig. 4;

[0032] Fig. 6 is a field curvature diagram of astigmatism of the lens in Fig. 4;

[0033] Fig. 7 is a distortion diagram of the lens in Fig. 4;

[0034] Fig. 8 is a structural schematic diagram of a projection device provided in an embodiment of the present application;

[0035] Fig. 9 is a spherical aberration diagram of the lens in Fig. 8;

[0036] Fig. 10 is a field curvature diagram of astigmatism of the lens in Fig. 8;

[0037] Fig. 11 is a distortion diagram of the lens in Fig. 8;

[0038] Fig. 12 is a structural schematic diagram of a projection device provided in an embodiment of the present application;

[0039] Fig. 13 is a spherical aberration diagram of the lens in Fig. 12;

[0040] Fig. 14 is a field curvature diagram of astigmatism of the lens in Fig. 12;

[0041] Fig. 15 is a distortion diagram of the lens in Fig. 12;

[0042] Fig. 16 is a structural schematic diagram of a projection device provided in an embodiment of the present application;

[0043] Fig. 17 is a spherical aberration diagram of the lens in Fig. 16;

[0044] Fig. 18 is a field curvature diagram of astigmatism of the lens in Fig. 16;

[0045] Fig. 19 is a distortion diagram of the lens in Fig. 16.

[0046] Explanation of reference signs: 100, vehicle lamp device; 110, housing; 120, projection device; 130, preset position; 10, lens; 101, lens group; 102, diaphragm; 103, cover glass; 20, display unit; 11, first lens; 12, second lens; 13, third lens; 14, fourth lens; 15, fifth lens. DETAILED DESCRIPTION

[0047] The terms used in the embodiment part of the present application are only used to explain the specific embodiments of the present application, and are not intended to limit the present application.

[0048] For the convenience of understanding, first, the related technical terms involved in the embodiments of the present application are explained and described.

[0049] Focal length, also known as focal length, is a way to measure the convergence or divergence of light in an optical system, which refers to the vertical distance from the optical center of the lens or lens group to the focal plane when the infinite scene through the lens or lens group forms a clear image on the focal plane.

[0050] Image side, with 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.

[0051] Object side, the side where the display unit is located is the object side, and the side of the lens facing the object side is the object side.

[0052] Total length (total track length, abbreviated as TTL), which refers to the total length from the vertex of the first lens adjacent to the object side in the lens to the imaging surface of the lens, also known as the total optical length.

[0053] Back focal length (abbreviated as BFL), defined as the distance from the lens closest to the imaging surface in the lens to the display unit.

[0054] Optical power, which represents the refractive ability of the lens to incident parallel light beams.

[0055] Positive optical power, which indicates that the lens has a positive focal length and has the effect of converging light rays.

[0056] Negative optical power, which indicates that the lens has a negative focal length and has the effect of diverging light rays.

[0057] Aperture, which is a device used to control the amount of light passing through the lens into the internal part of the electronic device, usually in the lens, and the size of the aperture is expressed by F# (F-number) value.

[0058] F-number, is the relative value (the reciprocal of the relative aperture) of the focal length of the lens / the diameter of the lens, the smaller the F-number, the more light in the same unit of time.

[0059] Cover glass (CG) is used to protect the display chip.

[0060] Target surface refers to the imaging part of the image sensor, in the embodiments of the present application, refers to the light emitting surface of the display image (such as the display surface of the display unit), the larger the target surface, the larger the light emitting area available for the display image, and the higher the brightness of the display image.

[0061] Field of view (FOV) is the angle formed by the two edges of the maximum range of the image passing through the lens with the lens as the vertex, which is called the field of view. The size of the field of view determines the field of view of the lens, the larger the field of view, the larger the field of view.

[0062] Axial chromatic aberration, also known as longitudinal chromatic aberration or position chromatic aberration, a bundle of parallel light rays along the optical axis will converge at different positions before and after the lens, which is called position chromatic aberration or axial chromatic aberration. This is because the lens images different wavelengths of light at different positions, so that the images of different colors of light cannot completely coincide on the imaging plane, and the dispersion of the composite color light is formed.

[0063] Distortion, also known as distortion, is the distortion degree of the image formed by the optical system relative to the object itself. Distortion is caused by the influence of diaphragm aberration, and the intersection height of the chief ray of different fields of view through the optical system is not equal to the ideal image height, and the difference between the two is the distortion. Therefore, distortion only changes the imaging position of the object point on the ideal plane, which causes the shape of the image to be distorted, but does not affect the clarity of the image.

[0064] FIG. 1 is a structural schematic diagram of a vehicle lamp device provided in the related art.

[0065] In the related art, referring to FIG. 1, the vehicle lamp device includes a lens 210, a modulation device 220, a light source 230, and a curved mirror 240, the curved mirror 240 is configured to reflect the light beam emitted by the light source 230 to the modulation device 220, the modulation device 220 is a liquid crystal on silicon (LCOS), and the modulation device 220 modulates the imaging light beam according to the light beam from the curved mirror 240 and emits the imaging light beam to the lens 210.

[0066] However, in order to meet the arrangement requirements of the modulation device 220, the light source 230, the curved mirror 240 and other devices, the back focal length of the lens 210 is long, which leads to a large volume of the vehicle lamp device, thereby increasing the difficulty of arranging the vehicle lamp device in the vehicle. In addition, the vehicle lamp device has a large number of parts, which leads to a complex structure of the vehicle lamp device. In addition, the light path in the vehicle lamp device is complex, which leads to a low illumination efficiency.

[0067] Therefore, the embodiments of the present application provide a lens, a projection device, a vehicle lamp device and a vehicle. The back focal length of the lens is small, so that the lens can be matched with a direct display chip such as a micro light emitting diode display chip to form a projection device with a small volume. The projection device is applied to the vehicle lamp device, so that the volume of the vehicle lamp device can be reduced, thereby reducing the difficulty of arranging the vehicle lamp device in the vehicle. In addition, the lens can have the characteristics of a large aperture and a large field of view, so that the imaging range of the lens can be increased. Therefore, the lens can be matched with a direct display chip with a large target surface, such as a direct display chip with a million pixels, that is, the large target surface design of the lens can be realized, which is beneficial to the increase of the light emitting area, so that the light emitting power of the projection device can be improved, thereby the brightness of the projection device can be improved. In addition, the optical performance of the lens can be improved, so that the imaging quality can be improved and the distortion can be reduced.

[0068] The vehicle provided by the embodiments of the present application can include but is not limited to a car, a truck, a motorcycle, a ship, an airplane, a helicopter, a mower, an entertainment vehicle, an amusement park vehicle, a construction equipment, a trolley, a golf cart, a train or a handcart. In addition, the vehicle provided by the embodiments of the present application can also be a new vehicle in the future.

[0069] The car can be an electric car, a fuel car or a hybrid car, for example, a pure electric car, a range-extended electric car, a new energy car, a fuel cell car, a hybrid electric car and the like. Exemplarily, the car is taken as the above vehicle for example in the following description.

[0070] Exemplarily, the vehicle can include a vehicle lamp device 100 and a vehicle body. The vehicle body can include a seat, an instrument panel, a vehicle body and other parts that complete the structure or function of the vehicle, such as a braking system, a driving system, a sensor and the like. The vehicle lamp device 100 has illumination function and projection function, and can perform illumination or meet projection requirements.

[0071] The vehicle lamp device 100 can include but is not limited to a pixel display car lamp, a near-field welcome car lamp, a pedestrian or interactive car lamp, a car headlamp and the like. Exemplarily, the car headlamp is taken as the above vehicle lamp device 100 for example in the embodiments of the present application. The car headlamp can be installed at the front or rear of the car, so that the car headlamp can realize illumination requirements and display requirements at the same time.

[0072] FIG. 2 is a structural schematic diagram of a vehicle lamp device 100 provided by an embodiment of the present application.

[0073] Referring to FIG. 2, the vehicle lamp device 100 can include a housing 110 and a projection device 120. At least part of the projection device 120 is arranged inside the housing 110, for example, as shown in FIG. 2, the projection device 120 is arranged inside the housing 110. Of course, the projection device 120 can also be partially arranged inside the housing 110 and partially arranged outside the housing 110. The projection device 120 is used to realize the lighting and other display requirements of the vehicle lamp device 100.

[0074] It should be noted that the projection device 120 provided by the embodiment of the present application can be applied not only to the vehicle lamp device 100 but also to projectors, head up display (HUD) devices, augmented reality (AR) glasses and other devices to realize display requirements.

[0075] Exemplarily, continuing to refer to FIG. 2, the projection device 120 can include a display unit 20 and a lens 10. The display surface of the display unit 20 is opposite to the lens closest to the object side in the lens 10, that is, the display unit 20 is arranged at the object side of the lens 10 and opposite to the display surface of the display unit 20 along the optical axis direction of the lens 10. The display unit 20 is configured to form a display image and transmit the display image to the lens 10 through the display surface. The lens 10 can magnify, focus, focus and the like on the display image, and the display image is irradiated to a preset position 130 after passing through the lens 10, realizing the projection display of the display image.

[0076] The preset position 130 can be understood as a structure for carrying the display image projected by the projection device 120 to realize the display of the display image. The preset position 130 can be a projection screen, a vehicle window, glass, a wall surface, a ground surface or any structure capable of carrying a display image, for example, the projection device 120 can project the display image onto the ground in front of the vehicle, so that the passengers can see the display image while watching the ground.

[0077] The display unit 20 can be a micro light-emitting diode (Micro LED) display chip, a sub-millimeter light-emitting diode (Mini LED) display chip or a thin film transistor (TFT) display chip or other direct display chip. By using the array light source such as micro light-emitting diode and sub-millimeter light-emitting diode and the display chip integrated with the chip, the structure of the display unit 20 is simplified, thereby simplifying the structure of the projection device 120, and the volume of the projection device 120 can also be reduced.

[0078] Since the rear focal length of the lens 10 provided by the embodiment of the present application is small and the lens 10 has a large target surface design, the lens 10 can support a large target surface direct display chip, for example, can be matched with a direct display chip of at least ten thousand pixels, which not only can reduce the volume of the projection device 120, but also can improve the brightness of the projection device 120.

[0079] The lens 10 provided by the embodiment of the present application will be described below in combination with the accompanying drawings.

[0080] FIG. 3 is a structural schematic diagram of a lens 10 provided by the embodiment of the present application.

[0081] Referring to FIG. 3, the lens 10 can include a lens group 101 and a stop 102. The lens group 101 includes at least five lenses arranged from an image side to an object side, for example, as shown in FIG. 3, the lens group 101 includes five lenses, which are a first lens 11, a second lens 12, a third lens 13, a fourth lens 14 and a fifth lens 15 arranged from the image side to the object side. Of course, the number of lenses of the lens group 101 can also be more than five. The number of lenses with optical power in the lens group 101 is at least five, for example, as shown in FIG. 3, the number of lenses with optical power in the lens group 101 is five. Of course, the number of lenses with optical power in the lens group 101 can also be more than five. The number of lenses with negative optical power in the lens group 101 is at least one, for example, as shown in FIG. 3, the number of lenses with negative optical power in the lens group 101 is one. Of course, the number of lenses with negative optical power in the lens group 101 can also be more than one.

[0082] Continuing to refer to FIG. 3, the stop 102 includes a first side and a second side oppositely arranged along the direction from the image side to the object side, the first side is close to the image side, and the second side is close to the object side. At least one of the first side and the second side is provided with a lens. When the lens is provided on the first side, the lens located on the first side and closest to the stop 102 has negative optical power. And / or, when the lens is provided on the second side, the lens located on the second side and closest to the stop 102 has negative optical power. That is, when the number of lenses with negative optical power is one, the lens with negative optical power can be located on the first side or the second side and closest to the stop 102, that is, the stop 102 is adjacent to the lens with negative optical power. Or, when the number of lenses with negative optical power is more than two, two lenses with negative optical power are respectively located on the first side and the second side and are respectively closest to the stop 102, that is, the stop 102 is located between the two lenses with negative optical power.

[0083] The lens with negative focal power has a negative contribution to the focal power of the lens 10. The lens with negative focal power is arranged beside the diaphragm 102, so that the influence of the lens with negative focal power on the focal power of the lens 10 is reduced, the comprehensive performance of the lens is exerted, and thus the comprehensive performance of the lens 10 can be improved.

[0084] By controlling the arrangement of the focal power of each lens in the lens group 101 and the positions of the diaphragm 102 and the lens with negative focal power, the back focal length of the lens 10 can be reduced, the back focal length of the lens 10 is controlled within a reasonable range, so that the lens 10 can be matched with a direct display chip such as a micro light emitting diode display chip to form a projection device 120 with small volume. The projection device 120 is applied to the vehicle lamp device 100, so that the volume of the vehicle lamp device 100 can be reduced, and thus the difficulty of arranging the vehicle lamp device 100 in a vehicle is reduced.

[0085] In addition, the lens 10 can also have the characteristics of large aperture and large field of view, and the imaging range of the lens 10 can be increased, so that the lens 10 can be matched with a direct display chip such as a micro light emitting diode display chip with a large target surface, for example, a direct display chip with ten million pixels, that is, the large target surface design of the lens 10 can be realized, which is beneficial to the increase of the light emitting area, so that the light emitting power of the projection device 120 can be improved, and thus the brightness of the projection device 120 can be improved. In addition, the optical performance of the lens 10 can be improved, so that the imaging quality is improved and the distortion is reduced.

[0086] It should be noted that, in addition to being composed of at least five lenses with focal power (for example, the lens 10 in FIG. 3 is composed of five lenses with focal power), the lens 10 can also be composed of a part of lenses with focal power and a part of lenses without focal power. For example, the lens 10 can include five lenses with focal power and two lenses without focal power.

[0087] Exemplarily, referring to FIG. 3, the first side and the second side can each be provided with lenses, that is, the diaphragm 102 is arranged between the lens closest to the image side in the lens group 101 and the lens closest to the object side in the lens group 101, so that the volume of the lens 10 can be further reduced, and the economy of the lens 10 can be improved.

[0088] Referring to FIG. 3, the first side is provided with a first lens 11 and a second lens 12, and the second side is provided with a third lens 13, a fourth lens 14 and a fifth lens 15. As can be seen, the number of lenses arranged on the first side is different from the number of lenses arranged on the second side. However, in some embodiments, the number of lenses arranged on the first side can also be the same as the number of lenses arranged on the second side.

[0089] Exemplarily, the number of the lens with negative optical power in the lens group 101 can be one, for example, as shown in FIG. 3, the number of the lens with negative optical power is one, at this time, the lens with negative optical power can be located at the first side or the second side and is closest to the diaphragm 102.

[0090] In view of the negative contribution of the lens with negative optical power to the optical power of the lens 10, setting the number of the lens with negative optical power to one can further reduce the influence of the lens with negative optical power on the optical power of the lens 10, and help to further improve the comprehensive performance of the lens 10.

[0091] In some possible implementation manners, the lens 10 can also satisfy the relationship: 4.5mm < BFL < 10mm, where BFL is the back focal length of the lens 10.

[0092] In this way, by controlling the back focal length of the lens 10 to be between 4.5mm and 10mm, the distance between the lens 10 and the direct display chip such as a micro light-emitting diode display chip can be further reduced, and the volume of the projection device 120 can be further reduced. In addition, it can also ensure that the lens 10 has the characteristics of a large aperture and a large field of view, so that the lens 10 can cooperate with a direct display chip with a large target surface to improve the brightness of the projection device 120. In addition, the imaging quality of the lens 10 can also be ensured.

[0093] The specific value of the back focal length BFL of the lens 10 is not limited here. The back focal length BFL of the lens 10 can be 4.55mm, 4.8mm, 5mm, 5.35mm, 5.55mm, 6mm, 6.55mm, 7mm, 7.698mm, 8mm, 8.556mm, 9mm, 9.355mm, 9.55mm, etc.

[0094] In some possible implementation manners, the lens 10 can also satisfy the relationship: 30.02mm < R1 < 100mm, where R1 is the radius of curvature of the image side surface of the lens closest to the image side in the lens group 101.

[0095] In this way, by letting the lens 10 satisfy the relationship: 30.02mm < R1 < 100mm, the manufacturing difficulty of the lens closest to the image side in the lens 10 can be reduced while realizing a large aperture and a large field of view, and the yield can be improved to improve the economy. In addition, the correction of aberration can be facilitated, and the optical performance of the lens 10 can be improved. In addition, the image side surface of the lens closest to the image side in the lens 10 can also be prevented from being too prominent or too flat, effectively balancing the optical performance and the lamp modeling of the lens 10.

[0096] The specific value of R1 is not limited herein. R1 can be 30.5 mm, 31 mm, 35 mm, 40 mm, 45.55 mm, 50.6 mm, 56.55 mm, 60 mm, 67.698 mm, 70 mm, 75.654 mm, 80 mm, 855 mm, 90 mm, etc.

[0097] In some possible implementation manners, the lens 10 satisfies a relationship: 15 mm < R2 < 30 mm, where R2 is the radius of curvature of the object side surface of the lens closest to the object side in the lens group 101.

[0098] In this way, by making the lens 10 satisfy the relationship: 15 mm < R2 < 30 mm, the manufacturing difficulty of the lens closest to the object side in the lens 10 can be reduced, the yield can be improved, and the economy can be improved on the premise of simultaneously realizing a large aperture and a large field of view. In addition, it can also avoid that the object side surface of the lens closest to the object side in the lens 10 is too prominent or too concave, and effectively balance the optical performance and the lamp modeling of the lens 10.

[0099] The specific value of R2 is not limited herein. R2 can be 15.315 mm, 16 mm, 16.5 mm, 17 mm, 17.55 mm, 18 mm, 19 mm, 20 mm, 21 mm, 23.65 mm, 25 mm, 25.98 mm, 28 mm, 29.5 mm, etc.

[0100] In some possible implementation manners, at least one lens in the lens group 101 can be an aspherical lens with optical power, for example, as shown in FIG. 3, the number of aspherical lenses in the lens group 101 can be one, and of course, the number of aspherical lenses can also be more than one.

[0101] In this way, by arranging the aspherical lens capable of correcting aberration in the lens group 101, the optical performance of the lens 10 can be further improved, and the imaging quality can be improved. In addition, the more the number of aspherical lenses, the greater the improvement of the optical performance of the lens 10.

[0102] It should be noted that at least one of the image side surface and the object side surface of the aspherical lens can be aspherical, and the more the number of aspherical surfaces of the aspherical lens, the greater the improvement of the optical performance of the lens 10.

[0103] The specific position of the aspherical lens is not limited herein. In some embodiments, the number of aspherical lenses can be two, and the two aspherical lenses can be located on the second side and closest to the diaphragm 102, that is, the two aspherical lenses are located between the diaphragm 102 and the display unit 20, and the two aspherical lenses are the two lenses closest to the diaphragm 102 among the lenses on the second side. In other embodiments, the number of aspherical lenses can also be one, and the aspherical lens can also be the lens closest to the image side among the lenses of the lens group 101.

[0104] In some possible implementation manners, all the lenses with optical power in the lens group 101 can be spherical lenses.

[0105] In this way, while the lens 10 has the characteristics of a large aperture and a large field of view, the manufacturing difficulty of each lens can be reduced, thereby reducing the cost of the lens 10, and further improving the economy of the lens 10. In addition, the back focal length of the lens 10 can be reduced, so that the lens 10 can be matched with a direct display chip and a large target design can be implemented.

[0106] In some possible implementation manners, the materials of all the lenses in the lens group 101 can be the same, for example, the materials of all the lenses in the lens group 101 can be optical glass or plastic.

[0107] In some possible implementation manners, the lens group 101 can also be composed of lenses made of at least two different materials, for example, the materials of some lenses in the lens group 101 can be optical glass, and the materials of other lenses can be plastic.

[0108] In some possible implementation manners, referring to FIG. 3, the lens 10 can further include a cover glass 103. The cover glass 103 is configured to be arranged between the lens group 101 and the display unit 20, and the cover glass 103 is configured to protect the display unit 20.

[0109] In some possible implementation manners, the lens 10 can further include a filter (not shown in the figure) for correcting color deviation. The filter is configured to be arranged between the lens group 101 and the display unit 20.

[0110] It should be noted that the lens 10 can include one of the cover glass 103 and the filter, or the lens 10 can include both the cover glass 103 and the filter.

[0111] The projection device 120 provided by the embodiments of the present application will be described below in combination with specific embodiments.

[0112] Embodiment One

[0113] FIG. 4 is a structural schematic diagram of the projection device 120 provided by the first embodiment of the present application.

[0114] Referring to FIG. 4, the projection device 120 can include a lens 10 and a display unit 20. The lens 10 includes a lens group 101, a diaphragm 102, and a cover glass 103. The lens group 101 includes a first lens 11, a second lens 12, a third lens 13, a fourth lens 14, and a fifth lens 15 arranged in order from an image side to an object side. The first lens 11 is closest to the image side, and the fifth lens 15 is closest to the object side. The diaphragm 102 is disposed between the second lens 12 and the third lens 13, and the cover glass 103 is disposed between the fifth lens 15 and the display unit 20. The five lenses of the first lens 11 to the fifth lens 15 can each be made of optical glass or plastic. The display unit 20 can be a direct display chip such as a Micro LED display chip, a Mini LED display chip, or a TFT display chip.

[0115] The first lens 11 has a positive refractive power, and a focal length f1 of the first lens 11 is 77.326 mm.

[0116] The second lens 12 has a negative refractive power, and a focal length f2 of the second lens 12 is -37.669 mm.

[0117] The third lens 13 has a positive refractive power, and a focal length f3 of the third lens 13 is 71.737 mm.

[0118] The fourth lens 14 has a positive refractive power, and a focal length f4 of the fourth lens 14 is 34.732 mm.

[0119] The fifth lens 15 has a positive refractive power, and a focal length f5 of the fifth lens 15 is 1520.703 mm.

[0120] As such, the number of lenses having a refractive power in the lens group 101 is five, which satisfies the requirement. In addition, the second lens 12 has a negative refractive power, and as shown in FIG. 4, the second lens 12 is located on the first side and is closest to the diaphragm 102, which satisfies the requirement.

[0121] The lens closest to the image side in the lens 10 is the first lens 11, and a radius of curvature R1 of the image side surface of the first lens 11 is 82.5151 mm, which is greater than 30.02 mm and less than 100 mm, satisfying the requirement.

[0122] The lens closest to the object side in the lens 10 is the fifth lens 15, and a radius of curvature R2 of the object side surface of the fifth lens 15 is 15.87 mm, which is greater than 15 mm and less than 30 mm, satisfying the requirement.

[0123] A back focal length BFL of the lens 10 is 7.25 mm, which is greater than 4.5 mm and less than 10 mm, satisfying the requirement.

[0124] Table 1 shows optical parameters of each optical element in the projection device 120 provided in this embodiment.

[0125] Wherein, 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 diaphragm 102. S6 is the image side surface of the third lens 13, S7 is the object side surface of the third lens 13. S8 is the image side surface of the fourth lens 14, S9 is the object side surface of the fourth lens 14. S10 is the image side surface of the fifth lens 15, S11 is the object side surface of the fifth lens 15. S12 is the image side surface of the cover glass 103, S13 is the object side surface of the cover glass 103. OBJ is the projection surface, and ImgH is the imaging surface.

[0126] R is the radius of curvature of the optical element (such as a lens or a glass cover plate) at the corresponding position of 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 illumination to each optical element, and Vd is the Abbe number of the optical element.

[0127] Table 2 shows the aspherical surface coefficients of each order in this embodiment.

[0128] As can be seen from Table 2, the third lens 13 and the fourth lens 14 in the lens 10 are both aspherical surfaces, that is, the lens 10 includes four aspherical surfaces, and the aspherical surface profile z of each aspherical surface can be calculated by the following aspherical surface formula:

[0129] Wherein, z is the sag of the aspherical surface, r is the radial coordinate of the aspherical surface, c is the spherical curvature at the vertex of the aspherical surface, k is the quadratic surface constant, and A4, A6, A8, … A30 are aspherical surface coefficients. In addition, Ai corresponds to the i-th order coefficient in Table 2, for example, A4 corresponds to the 4-th order coefficient in Table 2.

[0130] It should be noted that the aspherical surface profile z of the spherical lens can also be calculated by other aspherical surface formulas, which will not be described here.

[0131] Table 3 shows the optical parameters of the lens 10 provided in this embodiment.

[0132] As can be seen from Table 3, the lens 10 provided in this embodiment has the characteristics of large aperture and large field of view, and has a small back focal length.

[0133] Wherein, Fno is the aperture of the lens 10, BFL is the back focal length of the lens 10, TTL is the total track length of the lens 10, R1 is the radius of curvature of the image side surface of the lens closest to the image side in the lens 10, R2 is the radius of curvature of the object side surface of the lens closest to the object side in the lens 10, 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 14, and f5 is the focal length of the fifth lens 15.

[0134] Figure 5 is the spherical aberration diagram of the lens 10 in Figure 4. In Figure 5, the ordinate represents the normalized pupil coordinate, and the abscissa represents the axial aberration in millimeters. In Figure 5, 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 10 of the present embodiment. As can be seen from Figure 5, in the present embodiment, the axial aberration is controlled within a very small range, and better correction is obtained.

[0135] Figure 6 is the astigmatism field curvature diagram of the lens 10 in Figure 4, and Figure 7 is the distortion diagram of the lens 10 in Figure 4. In Figure 6, S represents the field curvature value of light with a wavelength of 525 nm on the meridional image surface, and T represents the field curvature value of light with a wavelength of 525 nm on the sagittal image surface. In Figure 7, the solid line represents the distortion value of light with a central wavelength of 525 nm passing through the lens 10 of the present embodiment. In the present embodiment, as can be seen from Figures 6 and 7, the lens 10 provided by the present embodiment controls the field curvature and distortion within the corresponding range, and has high imaging quality.

[0136] Embodiment Two:

[0137] Figure 8 is a structural schematic diagram of a projection device 120 provided by Embodiment Two of the present application.

[0138] Referring to Figure 8, the projection device 120 can include a lens 10 and a display unit 20. The lens 10 includes a lens group 101, a diaphragm 102, and a cover glass 103. The lens group 101 includes, arranged in order from the image side to the object side, a first lens 11, a second lens 12, a third lens 13, a fourth lens 14, and a fifth lens 15. The first lens 11 is closest to the image side, and the fifth lens 15 is closest to the object side. The diaphragm 102 is arranged between the second lens 12 and the third lens 13, and the cover glass 103 is arranged between the fifth lens 15 and the display unit 20. The materials of the five lenses from the first lens 11 to the fifth lens 15 can be optical glass or plastic. The display unit 20 can be a Micro LED display chip, a Mini LED display chip, or a TFT display chip, etc.

[0139] The first lens 11 has positive refractive power, and the focal length f1 of the first lens 11 is 46.801 mm.

[0140] The second lens 12 has a negative optical power, and the focal length f2 of the second lens 12 is -40.389 mm.

[0141] The third lens 13 has a positive optical power, and the focal length f3 of the third lens 13 is 41.173 mm.

[0142] The fourth lens 14 has a positive optical power, and the focal length f4 of the fourth lens 14 is 45.964 mm.

[0143] The fifth lens 15 has a positive optical power, and the focal length f5 of the fifth lens 15 is 357.239 mm.

[0144] Therefore, the number of lenses with optical power in the lens set 101 is five, which meets the requirement. In addition, the second lens 12 has a negative optical power, and as shown in FIG. 8, the second lens 12 is located on the first side and closest to the diaphragm 102, which meets the requirement.

[0145] The lens closest to the image side in the lens 10 is the first lens 11, and the radius of curvature R1 of the image side surface of the first lens 11 is 40.865 mm, which is greater than 30.02 mm and less than 100 mm, meeting the requirement.

[0146] The lens closest to the object side in the lens 10 is the fifth lens 15, and the radius of curvature R2 of the object side surface of the fifth lens 15 is 15.391 mm, which is greater than 15 mm and less than 30 mm, meeting the requirement.

[0147] The back focal length BFL of the lens 10 is 5.620 mm, which is greater than 4.5 mm and less than 10 mm, meeting the requirement.

[0148] Table 4 shows the optical parameters of each optical element in the projection device 120 provided in the second embodiment.

[0149] Wherein, 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 diaphragm 102. S6 is the image side surface of the third lens 13, S7 is the object side surface of the third lens 13. S8 is the image side surface of the fourth lens 14, S9 is the object side surface of the fourth lens 14. S10 is the image side surface of the fifth lens 15, S11 is the object side surface of the fifth lens 15. S12 is the image side surface of the cover glass 103, S13 is the object side surface of the cover glass 103. OBJ is the projection surface, and ImgH is the imaging surface.

[0150] R is the radius of curvature of the optical element (such as a lens or a glass cover plate) at the position corresponding to the optical axis, Th is the face thickness of the optical element in the direction of the optical axis, Nd is the refractive index of the d-line illumination to each optical element, and Vd is the Abbe number of the optical element.

[0151] Table 5 shows the aspherical surface coefficients of each order in the second embodiment.

[0152] As shown in Table 5, the first lens 11 in the lens 10 is an aspherical surface, that is, the lens 10 includes two aspherical surfaces, and the aspherical surface profile z of the first lens 11 can be calculated by the following aspherical surface formula:

[0153] wherein z is the sag of the aspherical surface, r is the radial coordinate of the aspherical surface, c is the vertex spherical curvature of the aspherical surface, k is the quadratic surface constant, A4, A6, A8, … A30 are aspherical surface coefficients. In addition, Ai corresponds to the i-th order coefficient in Table 2, for example, A4 corresponds to the 4-th order coefficient in Table 2.

[0154] It should be noted that the aspherical surface profile z of the spherical lens can also be calculated by other aspherical surface formulas, which will not be described here.

[0155] Table 6 shows the optical parameters of the lens 10 provided in the second embodiment.

[0156] As shown in Table 6, the lens 10 provided in the second embodiment has the characteristics of large aperture and large field of view, and has a small back focal length.

[0157] wherein Fno is the aperture of the lens 10, BFL is the back focal length of the lens 10, TTL is the total optical length of the lens 10, R1 is the radius of curvature of the image side surface of the lens closest to the image side in the lens 10, R2 is the radius of curvature of the object side surface of the lens closest to the object side in the lens 10, 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 14, and f5 is the focal length of the fifth lens 15.

[0158] FIG. 9 is a spherical aberration diagram of the lens 10 in FIG. 8. In FIG. 9, the vertical coordinate represents the normalized pupil coordinate, and the horizontal coordinate represents the axial aberration in the axial direction, with the unit being millimeters. In FIG. 9, 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 after passing through the lens 10 of the present embodiment. As can be seen from FIG. 9, in the present embodiment, the axial aberration is controlled within a very small range, and a good correction is obtained.

[0159] FIG. 10 is a field curvature graph of the lens 10 in FIG. 8, and FIG. 11 is a distortion graph of the lens 10 in FIG. 8. In FIG. 10, S represents the field curvature value of light with a wavelength of 525 nm on the meridional image surface, and T represents the field curvature value of light with a wavelength of 525 nm on the sagittal image surface. In FIG. 11, the solid line represents the distortion value of light with a central wavelength of 525 nm passing through the lens 10 of the present embodiment. In the present embodiment, it can be known from FIG. 10 and FIG. 11 that the lens 10 provided by the present embodiment controls the field curvature and the distortion within the corresponding ranges, and has high imaging quality.

[0160] Embodiment Three

[0161] FIG. 12 is a structural schematic diagram of a projection device 120 provided by Embodiment Three of the present application.

[0162] Referring to FIG. 12, the projection device 120 can include a lens 10 and a display unit 20. The lens 10 includes a lens group 101, a diaphragm 102, and a cover glass 103. The lens group 101 includes, arranged in order from the image side to the object side, a first lens 11, a second lens 12, a third lens 13, a fourth lens 14, and a fifth lens 15. The first lens 11 is closest to the image side, and the fifth lens 15 is closest to the image side. The diaphragm 102 is arranged between the second lens 12 and the third lens 13, and the cover glass 103 is arranged between the fifth lens 15 and the display unit 20. The materials of the five lenses from the first lens 11 to the fifth lens 15 can be optical glass or plastic. The display unit 20 can be a Micro LED display chip, a Mini LED display chip, or a TFT display chip, etc.

[0163] The first lens 11 has positive refractive power, and the focal length f1 of the first lens 11 is 53.949 mm.

[0164] The second lens 12 has negative refractive power, and the focal length f2 of the second lens 12 is -30.622 mm.

[0165] The third lens 13 has positive refractive power, and the focal length f3 of the third lens 13 is 46.543 mm.

[0166] The fourth lens 14 has positive refractive power, and the focal length f4 of the fourth lens 14 is 46.857 mm.

[0167] The fifth lens 15 has positive refractive power, and the focal length f5 of the fifth lens 15 is 181.938 mm.

[0168] Therefore, the number of lenses with refractive power in the lens group 101 is five, which meets the requirements. In addition, the second lens 12 has negative refractive power, and referring to FIG. 12, the second lens 12 is located on the first side and closest to the diaphragm 102, which meets the requirements.

[0169] The first lens 11 closest to the image side in the lens 10 has a radius of curvature R1 of the image side surface of 45.505 mm, which is greater than 30.02 mm and less than 100 mm, meeting the requirement.

[0170] The fifth lens 15 closest to the object side in the lens 10 has a radius of curvature R2 of the object side surface of 21.501 mm, which is greater than 15 mm and less than 30 mm, meeting the requirement.

[0171] The back focal length BFL of the lens 10 is 8.869 mm, which is greater than 4.5 mm and less than 10 mm, meeting the requirement.

[0172] Table 7 shows the optical parameters of each optical element in the projection device 120 provided in this embodiment three.

[0173] Wherein, 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 diaphragm 102. S6 is the image side surface of the third lens 13, S7 is the object side surface of the third lens 13. S8 is the image side surface of the fourth lens 14, S9 is the object side surface of the fourth lens 14. S10 is the image side surface of the fifth lens 15, S11 is the object side surface of the fifth lens 15. S12 is the image side surface of the cover glass 103, S13 is the object side surface of the cover glass 103. OBJ is the projection surface, and ImgH is the imaging surface.

[0174] R is the radius of curvature of an optical element (such as a lens or a glass cover plate) at a position corresponding to 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 illumination to each optical element, and Vd is the Abbe number of the optical element.

[0175] Table 8 shows the aspheric surface coefficients of each order in this embodiment three.

[0176] As can be seen from Table 8, the first lens 11 in the lens 10 is an aspheric lens, that is, the lens 10 includes two aspheric surfaces, and the aspheric surface of the first lens 11 can be calculated by the following aspheric surface formula:

[0177] Wherein, z is the sag of the aspheric surface, r is the radial coordinate of the aspheric surface, c is the vertex spherical curvature of the aspheric surface, k is the quadratic surface constant, and A4, A6, A8, … A30 are the aspheric surface coefficients. In addition, Ai corresponds to the i-th order coefficient in Table 2, for example, A4 corresponds to the 4-th order coefficient in Table 2. The conic coefficient refers to k, that is, the quadratic surface constant.

[0178] It should be noted that the aspheric surface shape z of the spherical mirror can also be calculated by other aspheric formulas, which will not be described here.

[0179] Table 9 shows the optical parameters of the lens 10 provided in this embodiment.

[0180] As can be seen from Table 9, the lens 10 provided in this embodiment has the characteristics of large aperture and large field of view, and has a small back focal length.

[0181] Wherein, Fno is the aperture of the lens 10, BFL is the back focal length of the lens 10, TTL is the total optical length of the lens 10, R1 is the radius of curvature of the image side surface of the lens closest to the image side in the lens 10, R2 is the radius of curvature of the object side surface of the lens closest to the object side in the lens 10, 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 14, and f5 is the focal length of the fifth lens 15.

[0182] Figure 13 is the spherical aberration diagram of the lens 10 in Figure 12. In Figure 13, the ordinate represents the normalized pupil coordinate, and the abscissa represents the axial aberration in millimeters. In Figure 13, 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 10 of the present embodiment. As can be seen from Figure 13, in the present embodiment, the axial aberration is controlled within a very small range, and better correction is obtained.

[0183] Figure 14 is the astigmatism field curve diagram of the lens 10 in Figure 12, and Figure 15 is the distortion diagram of the lens 10 in Figure 12. In Figure 14, S represents the field curvature value of light with a wavelength of 525 nm on the meridional image surface, and T represents the field curvature value of light with a wavelength of 525 nm on the sagittal image surface. In Figure 15, the solid line represents the distortion value of light with a central wavelength of 525 nm passing through the lens 10 of the present embodiment. In the present embodiment, as can be seen from Figures 14 and 15, the lens 10 provided in the present embodiment controls the field curvature and distortion within the corresponding range, and has high imaging quality.

[0184] Embodiment Four:

[0185] Figure 16 is a structural schematic diagram of a projection device 120 provided in the present embodiment.

[0186] Referring to FIG. 16, the projection device 120 can include a lens 10 and a display unit 20. The lens 10 includes a lens group 101, a diaphragm 102, and a cover glass 103. The lens group 101 includes a first lens 11, a second lens 12, a third lens 13, a fourth lens 14, and a fifth lens 15 arranged in order from an image side to an object side. The first lens 11 is closest to the image side, and the fifth lens 15 is closest to the image side. The diaphragm 102 is disposed between the second lens 12 and the third lens 13. The cover glass 103 is disposed between the fifth lens 15 and the display unit 20. The five lenses of the first lens 11 to the fifth lens 15 can be made of optical glass or plastic. The display unit 20 can be a direct display chip such as a Micro LED display chip, a Mini LED display chip, or a TFT display chip.

[0187] The first lens 11 has a positive focal power, and a focal length f1 of the first lens 11 is 46.620 mm.

[0188] The second lens 12 has a negative focal power, and a focal length f2 of the second lens 12 is -39.654 mm.

[0189] The third lens 13 has a positive focal power, and a focal length f3 of the third lens 13 is 62.501 mm.

[0190] The fourth lens 14 has a positive focal power, and a focal length f4 of the fourth lens 14 is 64.770 mm.

[0191] The fifth lens 15 has a positive focal power, and a focal length f5 of the fifth lens 15 is 58.035 mm.

[0192] Therefore, the number of lenses with focal power in the lens group 101 is five, which meets the requirement. In addition, the second lens 12 has a negative focal power, and the second lens 12 is located on the first side and closest to the diaphragm 102, as shown in FIG. 16, which meets the requirement.

[0193] The lens closest to the image side in the lens 10 is the first lens 11, and a radius of curvature R1 of the image side surface of the first lens 11 is 49.097 mm, which is greater than 30.02 mm and less than 100 mm, meeting the requirement.

[0194] The lens closest to the object side in the lens 10 is the fifth lens 15, and a radius of curvature R2 of the object side surface of the fifth lens 15 is 39.260 mm, which is greater than 15 mm and less than 30 mm, meeting the requirement.

[0195] A back focal length BFL of the lens 10 is 5.190 mm, which is greater than 4.5 mm and less than 10 mm, meeting the requirement.

[0196] Table 10 shows optical parameters of each optical element in the projection device 120 provided in the fourth embodiment.

[0197] As shown in Table 10, each lens in the lens 10 is a spherical lens.

[0198] S1 is the image side surface of the first lens 11, and S2 is the object side surface of the first lens 11. S3 is the image side surface of the second lens 12, and S4 is the object side surface of the second lens 12. S5 is the diaphragm 102. S6 is the image side surface of the third lens 13, and S7 is the object side surface of the third lens 13. S8 is the image side surface of the fourth lens 14, and S9 is the object side surface of the fourth lens 14. S10 is the image side surface of the fifth lens 15, and S11 is the object side surface of the fifth lens 15. S12 is the image side surface of the cover glass 103, and S13 is the object side surface of the cover glass 103. OBJ is the projection surface, and ImgH is the imaging surface.

[0199] R is the radius of curvature of the optical element (such as a lens or a glass cover plate) at the position corresponding to 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 illumination to each optical element, and Vd is the Abbe number of the optical element.

[0200] Table 11 shows the optical parameters of the lens 10 provided in the fourth embodiment.

[0201] As shown in Table 11, the lens 10 provided in the fourth embodiment has the characteristics of large aperture and large field of view, and has a small back focal length.

[0202] In the formula, Fno is the aperture of the lens 10, BFL is the back focal length of the lens 10, TTL is the total optical length of the lens 10, R1 is the radius of curvature of the image side surface of the lens closest to the image side in the lens 10, R2 is the radius of curvature of the object side surface of the lens closest to the object side in the lens 10, 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 14, and f5 is the focal length of the fifth lens 15.

[0203] FIG. 17 is a spherical aberration diagram of the lens 10 in FIG. 16. In FIG. 17, the vertical coordinate represents the normalized pupil coordinate, and the horizontal coordinate represents the axial aberration in the axial direction, in millimeters. In FIG. 17, 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 after passing through the lens 10 of the present embodiment. As can be seen from FIG. 17, in the present embodiment, the axial aberration is controlled within a very small range, and a good correction is obtained.

[0204] FIG. 18 is a field curvature graph of the lens 10 in FIG. 16, and FIG. 19 is a distortion graph of the lens 10 in FIG. 16. In FIG. 18, S represents the field curvature value of light with a wavelength of 525 nm on the tangential image plane, and T represents the field curvature value of light with a wavelength of 525 nm on the sagittal image plane. In FIG. 19, the solid line represents the distortion value of light with a center wavelength of 525 nm passing through the lens 10 of the present embodiment. In the present embodiment, as can be seen from FIG. 18 and FIG. 19, the lens 10 provided by the present embodiment controls the field curvature and the distortion within the corresponding ranges, and has high imaging quality.

[0205] In the description of the embodiments of the present application, it should be noted that unless specifically defined and limited otherwise, the terms "mount", "connected", "connection" should be understood broadly, for example, can be fixedly connected, can be indirectly connected through an intermediate medium, can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0206] In the embodiments of the present application or the devices or elements implied by the present application must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the embodiments of the present application. In the description of the embodiments of the present application, the meaning of "a plurality of" is two or more, unless otherwise specified.

[0207] The terms "first", "second", "third", "fourth" and the like (if any) in the description of the embodiments of the present application and the above drawings are used to distinguish similar objects, and do not necessarily have to describe a specific order or sequence. It should be understood that the data thus used 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 including a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0208] The term "a plurality of" herein refers to two or more. The term "and / or" herein is only a description of the association relationship between the associated objects, which means that there can be three relationships, for example, A and / or B can represent the three cases of A alone, A and B together, and B alone. In addition, the character " / " herein generally represents that the front and rear associated objects have an "or" relationship; in the formula, the character " / " represents that the front and rear associated objects have a "division" relationship.

[0209] It can be understood that various numerical numbers involved in the embodiments of the present application are only distinguished for convenience of description, and are not used to limit the scope of the embodiments of the present application.

[0210] It can be understood that the size of the serial numbers of the above processes in the embodiments of the present application does not mean the order of execution, and the execution order of the processes should be determined according to their functions and inherent logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

Claims

1. A lens characterized by comprising: The lens group and the diaphragm are included. The lens group includes at least five lenses arranged from an image side to an object side, the number of lenses with optical power in the lens group is at least five, and the number of lenses with negative optical power in the lens group is at least one. The diaphragm includes a first side and a second side oppositely arranged in an image side to an object side direction, the first side is close to the image side, the second side is close to the object side, and at least one of the first side and the second side is provided with the lenses, wherein: When the lenses are provided on the first side, the lens located on the first side and closest to the diaphragm has negative optical power; and / or, When the lenses are provided on the second side, the lens located on the second side and closest to the diaphragm has negative optical power.

2. The lens according to claim 1, characterized in that, The lens satisfies the relationship: 4.5mm < BFL < 10mm, wherein the BFL is the back focal length of the lens.

3. The lens according to claim 1 or 2, characterized in that, The lens satisfies the relationship: 30.02mm < R1 < 100mm, wherein the R1 is the radius of curvature of the image side surface of the lens closest to the image side in the lens group.

4. The lens according to any one of claims 1 to 3, characterized in that, The lens satisfies the relationship: 15mm < R2 < 30mm, wherein the R2 is the radius of curvature of the object side surface of the lens closest to the object side in the lens group.

5. The lens according to any one of claims 1 to 4, characterized in that, The first side and the second side are both provided with the lenses.

6. The lens according to any one of claims 1 to 5, characterized in that, At least one of the lenses in the lens group is an aspheric lens with optical power.

7. The lens according to any one of claims 1 to 5, characterized in that All of the lenses with optical power in the lens group are spherical lenses.

8. The lens according to any one of claims 1 to 7, characterized in that The number of lenses with negative optical power in the lens group is one.

9. A projection apparatus, characterized by comprising: The lens is included in a display unit and any one of claims 1 to 8. The display surface of the display unit is opposite to the lens closest to the object side in the lens, and the display unit is configured to form a display image and transmit the display image through the display surface to the lens.

10. The projection apparatus according to claim 9, wherein, The display unit is a micro light emitting diode display chip, a sub-millimeter light emitting diode display chip or a thin film field effect transistor display chip.

11. A vehicle lamp device characterized by comprising: The projection device is included in a housing and any one of claims 9 or 10, and at least part of the projection device is arranged inside the housing.

12. A vehicle, characterized by The vehicle lamp device is included in claim 11.

Images