Projection module and vehicle

Abstract

The invention discloses a projection module which can be applied to a lighting system of a vehicle, other projection scenes with limited space / light source / chip and the like. The projection module comprises a light source device, a lens group and a cylindrical lens group which are sequentially arranged on a light path transmission path, emergent light of the light source device forms a light beam after passing through the lens group, and the light beam is projected to the outside of the vehicle through the cylindrical mirror group; the cylindrical mirror group is used for adjusting the magnification of the light beam on the first axis and the second axis so as to change the picture proportion of the light beam projected to the outside, and the first axis, the second axis and the optical axis are perpendicular to one another. And the amplification factors of the light beams on the first axis and the second axis are adjusted to be different through the cylindrical mirror group. Compared with the prior art, the magnification ratios of the projection module in the transverse direction and the longitudinal direction are the same.

Description

Technical Field

[0001] The present application relates to the field of display, and in particular to a projection module and a vehicle. Background Art

[0002] With the booming development of fields such as autonomous driving and human-vehicle interaction, car lights are also evolving towards intelligence and pixelation. Smart pixelated smart car lights can realize two basic functions: lighting and projection.

[0003] At present, the optical system of smart car lights includes two parts: a luminous image source and a projection lens. The projection lens often adopts a rotationally symmetrical design. Since the lens with a rotationally symmetrical design has the same magnification in the horizontal and vertical directions, the aspect ratio of the projection FOV of the car lights ultimately depends on the length-to-width ratio of the light source or display chip.

[0004] However, when the aspect ratio requirement of the projection field of view (FOV) of the headlight is inconsistent with the aspect ratio of the light source or the chip, a compromise can only be made in one direction of the FOV, and the optimal aspect ratio cannot be achieved. Summary of the invention

[0005] The present application provides a projection module and a vehicle, by adding a cylindrical lens group in the projection module, and adjusting the magnification of the light beam on the first axis and the second axis through the cylindrical lens group. The projection module can have different magnifications in the horizontal and vertical directions, and the projected image is compressed in the vertical direction, thereby increasing the energy density in the vertical direction and the FOV in the horizontal direction. Compared with the prior art in which the magnification ratios in the horizontal and vertical directions are the same, the projection module provided by the present application can break through the constraints of the aspect ratio of the image source through the cylindrical lens group and achieve an ideal frame ratio.

[0006] The first aspect of the embodiment of the present application provides a projection module, which can be applied to the lighting system of a vehicle, other projection scenes with limited space / light source / chip, etc. The projection module includes: a light source device, a lens group and a cylindrical lens group arranged in sequence on the optical transmission path; the output light of the light source device forms a light beam after passing through the lens group, and the light beam is projected to the outside of the vehicle through the cylindrical lens group; the cylindrical lens group is used to adjust the magnification of the light beam on the first axis and the second axis, thereby changing the aspect ratio of the light beam projected to the outside, and the first axis, the second axis and the optical axis are perpendicular to each other. For example, in the scenario of road projection, the first axis is the road width direction, and the second axis is perpendicular to the road direction. For another example, the second axis can also be the road width direction, and the first axis is perpendicular to the road direction.

[0007] In the embodiment of the present application, a cylindrical lens group is added to the projection module, and the magnification of the light beam on the first axis and the second axis is adjusted differently by the cylindrical lens group. The projection module can have different magnifications in the horizontal and vertical directions, and the projected image is compressed in the vertical direction, thereby increasing the energy density in the vertical direction and the FOV in the horizontal direction. Compared with the prior art in which the magnification ratios in the horizontal and vertical directions are the same, the projection module provided by the present application can break through the constraints of the aspect ratio of the image source through the cylindrical lens group and achieve an ideal frame ratio.

[0008] Optionally, in a possible implementation of the first aspect, a modulation transfer function (MTF) of the above-mentioned projection module is greater than or equal to a first preset threshold, and / or an aperture coefficient (Fnumber, FNO) of the projection module is less than or equal to a second preset threshold.

[0009] In this possible implementation, the projection module takes imaging issues into consideration while adjusting the magnification through MTF and FNO, so that the projection effect of the projection module is better.

[0010] Optionally, in a possible implementation manner of the first aspect, the first preset threshold is greater than or equal to 0.5, and the second preset threshold is less than or equal to 1.5.

[0011] In this possible implementation, two preset thresholds are defined, which can make the projection effect of the projection module better.

[0012] Optionally, in a possible implementation manner of the first aspect, the parameters of the above-mentioned cylindrical lens group are related to the magnification, and the parameters include at least one of the following: a distance between at least two cylindrical lenses in the cylindrical lens group, and an optical focal length of the cylindrical lenses in the cylindrical lens group.

[0013] In this possible implementation, the horizontal and vertical ratios of the projection image can be flexibly adjusted by parameters such as the distance between cylindrical mirrors and the optical focal length.

[0014] Optionally, in a possible implementation manner of the first aspect, the above-mentioned cylindrical mirror group includes a first cylindrical mirror and a second cylindrical mirror arranged in sequence on the optical path, the first cylindrical mirror has a negative optical focal length, and the second cylindrical mirror has a positive optical focal length.

[0015] In this possible implementation, when a parallel light beam is incident, after being diverged by a first cylindrical mirror with negative optical focal length, the divergence angle entering a second cylindrical mirror with positive optical focal length becomes smaller, thereby compressing the field of view angle of one axis (for example, the axis perpendicular to the road), thereby achieving the purpose of adjusting the frame ratio (i.e., the projection ratio of one axis relative to another axis).

[0016] Optionally, in a possible implementation of the first aspect, a surface of the first cylindrical mirror close to the light source device is a concave surface, and a surface of the first cylindrical mirror away from the light source device is a plane; a surface of the second cylindrical mirror close to the first cylindrical mirror is a plane, and a surface of the second cylindrical mirror away from the first cylindrical mirror is a convex surface.

[0017] In this possible implementation, a relatively economical surface setting is proposed. Of course, in practical applications, the first cylindrical mirror may also be a biconcave surface, and the second cylindrical mirror may be a biconvex surface.

[0018] Optionally, in a possible implementation of the first aspect, the focal length of the first cylindrical mirror on the optical axis is f1, the focal length of the second cylindrical mirror on the optical axis is f2, and the equivalent focal length of the projection module on the optical axis is f x , and f x <|f1|-|f2|<2f x .

[0019] In this possible implementation, by limiting the focal length of the cylindrical mirror, the imaging clarity and the total optical length of the projection lens group can meet actual requirements, and the space of the projection lens group can be reduced.

[0020] Optionally, in a possible implementation of the first aspect, the center thickness of the first cylindrical mirror is the first thickness, the center thickness of the second cylindrical mirror is the second thickness, and the ratio of the second thickness to the first thickness is less than 4.5 mm and greater than 2 mm.

[0021] In this possible implementation, by limiting the center thickness, the cylindrical lens group takes both strength and cost into consideration.

[0022] Optionally, in a possible implementation manner of the first aspect, the cylindrical lens group and the lens group are detachably connected.

[0023] In this possible implementation, the cylindrical lens group is a detachable component, and the cylindrical lens group can be directly added on the basis of the structure of the existing lens group, and then the magnification of the light beam on the first axis and the second axis can be adjusted by the cylindrical lens group. The projection module can have different magnifications in the horizontal and vertical directions, and the projected image is compressed in the vertical direction, which improves the energy density in the vertical direction and the FOV in the horizontal direction. Compared with the prior art in which the magnification ratios in the horizontal and vertical directions are the same, the projection module provided by the present application can break through the constraints of the aspect ratio of the image source through the cylindrical lens group and achieve an ideal frame ratio.

[0024] Optionally, in a possible implementation manner of the first aspect, the light source device and the lens group are rotationally symmetric structures.

[0025] In this possible implementation, when the cylindrical lens group is a detachable component, after the cylindrical lens group is removed, the entire projection lens has a rotationally symmetrical structure and still has good imaging performance.

[0026] Optionally, in a possible implementation manner of the first aspect, a cross-section of the lens group and the cylindrical lens group along the optical axis is circular or polygonal.

[0027] In this possible implementation, when the interface is circular, the projection of the projection module under different fields of view can be better controlled.

[0028] Optionally, in a possible implementation manner of the first aspect, the magnifications of the above-mentioned light beam on the first axis and the second axis include: a ratio of the magnification of the light beam on the first axis to the magnification of the light beam on the second axis is in a first interval, and the first interval includes 1.2 to 1.7.

[0029] In this possible implementation, when the ratio of the magnification of the light beam on the first axis to the magnification of the light beam on the second axis is in the first interval, the aspect ratio of the projected image can be increased by the first interval times compared with the image source. For example, when the ratio of the magnification of the light beam on the first axis to the magnification of the light beam on the second axis is 1:1.25, that is, the aspect ratio of the projected image is increased by 1.25 times compared with the image source, when the aspect ratio of the light source is 4:1, the aspect ratio of the final projected image is 5:1.

[0030] Optionally, in a possible implementation of the first aspect, the above-mentioned light source device includes a light source and a projection element, the light source includes at least one of the following: light emitting diode (LED), laser diode (LD), micro light emitting diode display (MicroLED), etc., and the projection element includes at least one of the following: liquid crystal display (LCD), liquid crystal on silicon (LCOS), digital micro-mirror device (DMD), etc.

[0031] In this possible implementation, when the light source device includes a light source and a projection element, the projection module is also used to perform imaging outside the vehicle, and the horizontal and vertical ratios of the projection frame are adjusted through the parameters of the cylindrical lens group.

[0032] The second aspect of the present application provides a vehicle, wherein the vehicle comprises a projection module as described in the first aspect or any optional manner of the first aspect, and the projection module is installed on the vehicle.

[0033] Optionally, in a possible implementation of the second aspect, the above-mentioned vehicle also includes a processor, which is used to send a control signal to the projection module, and the control signal is used to adjust the magnification of the light beam on the first axis and the second axis, thereby changing the aspect ratio of the light beam projected to the outside, and the first axis, the second axis and the optical axis are perpendicular to each other.

[0034] It can be seen from the above technical solutions that the present application has the following advantages: by adding a cylindrical lens group to the projection module, and adjusting the magnification of the light beam on the first axis and the second axis to be different through the cylindrical lens group, the projection module can have different magnifications in the horizontal and vertical directions, and the projected image is compressed in the vertical direction, thereby increasing the energy density in the vertical direction and the FOV in the horizontal direction. Compared with the prior art in which the magnification ratios in the horizontal and vertical directions are the same, the projection module provided by the present application can break through the constraints of the aspect ratio of the image source through the cylindrical lens group and achieve an ideal frame ratio. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 A schematic diagram of the structure of a projection module provided in an embodiment of the present application;

[0036] Figure 2 and Figure 3 Schematic diagram of several optical performance simulation results of the projection module provided in the embodiment of the present application;

[0037] Figure 4 A schematic diagram of the structure of a lens group in a projection module provided in an embodiment of the present application;

[0038] Figure 5 Another structural schematic diagram of the projection module provided in the embodiment of the present application;

[0039] Figure 6 A schematic diagram of a projection module installed in a vehicle is provided for an embodiment of the present application;

[0040] Figure 7 A schematic diagram of the relationship between the projection image and the road after the projection module is installed in a vehicle is provided for the embodiment of the present application;

[0041] Figure 8 A schematic diagram of a possible functional framework of a vehicle provided in an embodiment of the present application. DETAILED DESCRIPTION

[0042] The present application provides a projection module and a vehicle, by adding a cylindrical lens group in the projection module, and adjusting the magnification of the light beam on the first axis and the second axis through the cylindrical lens group. The projection module can have different magnifications in the horizontal and vertical directions, and the projected image is compressed in the vertical direction, thereby increasing the energy density in the vertical direction and the FOV in the horizontal direction. Compared with the prior art in which the magnification ratios in the horizontal and vertical directions are the same, the projection module provided by the present application can break through the constraints of the aspect ratio of the image source through the cylindrical lens group and achieve an ideal frame ratio.

[0043] At present, the optical system of smart car lights includes two parts: a luminous image source and a projection lens. The projection lens often adopts a rotationally symmetrical design. Since the lens with a rotationally symmetrical design has the same magnification in the horizontal and vertical directions, the aspect ratio of the projection FOV of the car lights ultimately depends on the length-to-width ratio of the light source or display chip.

[0044] However, when the aspect ratio requirement of the projection field of view (FOV) of the headlight is inconsistent with the aspect ratio of the light source or the chip, a compromise can only be made in one direction of the FOV, and the optimal aspect ratio cannot be achieved.

[0045] To this end, the present application provides a projection module. It can be applied to the lighting system of a vehicle, other projection scenes with limited space / light source / chip, and other scenes. The embodiment of the present application is only described by taking the headlights of a car applied to a vehicle as an example, and of course it can also be applied to the taillights, brake lights, head-up displays, etc. of the vehicle. The projection module includes: a light source device, a lens group, and a cylindrical lens group arranged in sequence on the optical transmission path; the output light of the light source device forms a light beam after passing through the lens group, and the light beam is projected to the outside of the vehicle through the cylindrical lens group; the cylindrical lens group is used to adjust the magnification of the light beam on the first axis and the second axis, thereby changing the frame ratio of the light beam projected to the outside, and the first axis, the second axis, and the optical axis are perpendicular to each other. For example, in the scene of road projection, the first axis is the road width direction, and the second axis is the perpendicular road direction. It can be understood that the second axis can also be the road width direction, and the first axis is the perpendicular road direction. By adding a cylindrical lens group to the projection module and adjusting the magnification of the light beam on the first axis and the second axis through the cylindrical lens group, the projection module can have different magnifications in the horizontal and vertical directions, and the projected image is compressed in the vertical direction, thereby achieving the aspect ratio on the horizontal and vertical lines of the road. The energy density in the vertical direction and the FOV in the horizontal direction are improved. Compared with the prior art in which the magnification ratio in the horizontal and vertical directions is the same, the projection module provided by the present application can break through the constraints of the aspect ratio of the image source through the cylindrical lens group and achieve an ideal aspect ratio.

[0046] Of course, in order to make the projection module better applied to projection scenes with limited scenes, the modulation transfer function (MTF) of the projection module can be set to be greater than or equal to the first preset threshold, and / or the aperture factor (Fnumber, FNO) of the projection module can be set to be less than or equal to the second preset threshold. In this possible implementation, by setting the value of MTF and / or FNO, the projection module considers the imaging problem while adjusting the magnification, so that the projection effect of the projection module is better.

[0047] Optionally, the MTF of the projection module is set to be greater than or equal to a first preset threshold, and the FNO of the projection module is set to be less than or equal to a second preset threshold. The first preset threshold is greater than or equal to 0.5, and the second preset threshold is less than or equal to 1.5. That is, the value range of the first preset threshold can be 0.5 to 1, for example, the first preset threshold is 0.5, 0.55, 0.6, 0.7, 0.8, etc., and the second preset threshold is 1.5, 1.4, 1.3, 1.2, 1.1, 0.8, etc.

[0048] It is understandable that the above threshold values ​​are only examples. Generally, the larger the MTF, the better, and the smaller the FNO, the better. However, in actual applications, in order to make the FNO smaller, the MTF may be smaller (even less than 0.5). It is also possible to make the MTF larger and the FNO larger (even greater than 1.5). That is, the above first preset threshold and the second preset threshold can be flexibly adjusted as needed, and the specifics are not limited here.

[0049] In the embodiment of the present application, the light source device may include at least one of the following: a light source and a projection element. The light source includes at least one of a light emitting diode (LED), a laser diode (LD), a micro light emitting diode display (MicroLED), etc. The projection element includes at least one of a liquid crystal display (LCD), a liquid crystal on silicon (LCOS), a digital micro-mirror device (DMD), etc.

[0050] The lens group may include at least one of the following: a lens (e.g., a convex lens, a concave lens, etc.), a reflector, a prism or a Fresnel mirror, etc. In addition, the number of lenses in the lens group may be one or more, which is not specifically limited here. The reflector may be a curved surface with a certain curvature (e.g., a curved surface radius between 1000 mm and 100,000 mm), or a free curved surface, or a spherical surface, etc. When the reflector has a curved surface with curvature, the optical focal length can be corrected to enhance the projection effect. The function of the lens group is mainly to clearly display the light source, and the ratio of the lens group and the ratio of the light source may be the same or different.

[0051] The cylindrical lens group includes at least two cylindrical lenses. For the convenience of description, the embodiment of the present application only takes the cylindrical lens group including the first cylindrical lens and the second cylindrical lens as an example for exemplary description. It can be understood that in actual applications, the number of cylindrical lenses in the cylindrical lens group can be more, which is not specifically limited here.

[0052] In addition, the cylindrical lens group is used to adjust the magnification of the light beam on the first axis and the second axis, which can be understood as: the parameters of the cylindrical lens group can adjust the magnification of the light beam on the first axis and the second axis, that is, the parameters of the cylindrical lens group are related to the magnification. The parameters of the cylindrical lens group include at least one of the following: the distance between at least two cylindrical lenses in the cylindrical lens group, the optical power of the cylindrical lenses in the cylindrical lens group, etc. Among them, the adjustment of the optical power can be adjusted by parameters such as radius, thickness, and material.

[0053] Exemplarily, the cylindrical lens group includes a first cylindrical lens and a second cylindrical lens arranged in sequence on the optical transmission path, the first cylindrical lens has a negative optical power, and the second cylindrical lens has a positive optical power.

[0054] In this example, when a parallel light beam is incident, it is diverged by the first cylindrical mirror with negative optical power and then imaged on the focal plane by the second cylindrical mirror. The principal surface of this optical system is removed from the objective lens, so a working distance longer than the focal length is obtained, and an off-axis light beam with a large field of view is diverged by the first cylindrical mirror with negative optical power, and the divergence angle of the beam entering the second cylindrical mirror with positive optical power becomes smaller, thereby achieving the purpose of wide angle.

[0055] Optionally, a surface of the first cylindrical mirror close to the light source device is a concave surface, and a surface of the first cylindrical mirror far from the light source device is a flat surface, or both surfaces of the first cylindrical mirror are concave surfaces.

[0056] Optionally, a surface of the second cylindrical mirror close to the first cylindrical mirror is a plane, and a surface of the second cylindrical mirror far from the first cylindrical mirror is a convex surface, or both surfaces of the second cylindrical mirror are convex surfaces.

[0057] Optionally, the cylindrical lens group may be a detachable component, and after the cylindrical lens group is detached, the light source device and the lens group are rotationally symmetrical structures and still have good imaging performance.

[0058] Of course, in order to adjust the intensity of the light beam passing through the projection module, improve the imaging quality of the off-axis point or the imaging beam aperture and other factors, the projection module may also include an aperture. Specifically, the aperture may be set in the lens group.

[0059] It can be understood that the material of the lens / cylindrical mirror involved in the embodiments of the present application can be light-transmissive, for example, it can be plastic or glass, etc., and the specifics are not limited here.

[0060] In order to conveniently describe the structure of the projection module, the following takes a cylindrical lens group including a first cylindrical lens and a second cylindrical lens as an example to describe the projection module through views under different axes.

[0061] See also Figure 1 , a coordinate system of a projection module and a schematic diagram of the structure in different views provided in an embodiment of the present application. The coordinate system includes an X-axis, a Y-axis and a Z-axis. The X-axis, the Y-axis and the Z-axis are perpendicular to each other, and the X-axis is the optical axis of the projection module.

[0062] The projection module includes a light source device 101, a lens group 102, and a cylindrical lens group 103, which are sequentially arranged on the optical transmission path. The cylindrical lens group includes a first cylindrical lens 1031 and a second cylindrical lens 1032, which are sequentially arranged on the optical transmission path. The first cylindrical lens 1031 has a negative optical focal length, and the second cylindrical lens 1032 has a positive optical focal length. When a parallel light beam is incident, after being diverged by the first cylindrical lens with a negative optical focal length, the divergence angle entering the second cylindrical lens with a positive optical focal length becomes smaller, thereby compressing the field angle of one axis (for example, an axis perpendicular to the road), and achieving the purpose of adjusting the frame ratio (that is, the projection ratio of one axis relative to another axis).

[0063] Depend on Figure 1 It can be seen that in the XZ view, the side of the first cylindrical mirror 1031 close to the light source device 101 is a concave surface, and the side of the first cylindrical mirror 1031 far from the light source device 101 is a flat surface. The side of the second cylindrical mirror 1032 close to the first cylindrical mirror 1031 is a flat surface, and the side of the second cylindrical mirror 1032 far from the first cylindrical mirror 1031 is a convex surface. The projections of the first cylindrical mirror 1031 and the second cylindrical mirror 1032 in the XY view are rectangles.

[0064] Understandably, Figure 1 The structures of the first cylindrical mirror and the second cylindrical mirror are only examples. In practical applications, the first cylindrical mirror and the second cylindrical mirror may have other configurations. For example, both surfaces of the first cylindrical mirror may be concave. For another example, both surfaces of the second cylindrical mirror may be convex.

[0065] In addition, the projections of the first cylindrical mirror and the second cylindrical mirror in the YZ view may be circular. It is understandable that in practical applications, the projections of the first cylindrical mirror and the second cylindrical mirror in the YZ view may also be polygonal (such as a rectangle), etc., which is not specifically limited here.

[0066] Optionally, the focal length of the first cylindrical mirror on the optical axis is f1, the focal length of the second cylindrical mirror on the optical axis is f2, and the equivalent focal length of the projection module on the optical axis is f x , and f x <|f1|-|f2|<2f x The imaging clarity and the total optical length of the projection lens group can meet actual needs, and the space of the projection lens group can be reduced.

[0067] Optionally, the center thickness of the first cylindrical mirror is the first thickness, the center thickness of the second cylindrical mirror is the second thickness, and the ratio of the second thickness to the first thickness is less than 4.5 mm and greater than 2 mm, so that the cylindrical mirror assembly can take both strength and cost into consideration.

[0068] Optionally, the magnification of the light beam on the first axis and the second axis includes: the ratio of the magnification of the light beam on the first axis to the magnification of the light beam on the second axis is in a first interval, and the first interval includes 1.2 to 1.7. The following is an example:

[0069] It is understandable that the aperture factor (Fnumber, FNO) can be set according to actual needs, thereby achieving the requirements of illumination and / or projection clarity. For example, if FNO=1.1 is set, the various parameters of the projection module can be determined according to the corresponding optical formula. The following is an example of each parameter.

[0070] In one possible implementation, the ratio of the magnification of the projection module in the Y and Z directions is 1:1.25. That is, the aspect ratio of the projected image is increased by 1.25 times compared to the image source. When the aspect ratio of the light source is 4:1, the aspect ratio of the final projected image is 5:1. While the vertical FOV meets the demand, the horizontal FOV of the headlight is expanded to achieve lighting with a larger field of view.

[0071] In this case, the optical parameters of each surface of the first cylindrical mirror and the second cylindrical mirror may be as shown in Table 1:

[0072] Table 1

[0073] surface Face type Radius of curvature (R) Center thickness (T) Refractive index(Nd) Abbe number (Vd) S1 cylinder 82.283 12.17 1.49 53.31 S2 cylinder ∞ 23.30 - - S3 cylinder ∞ 3.00 1.53 55.98 S4 cylinder 70.401 4.00 - -

[0074] The cylindrical mirror groups are arranged in order from the light emitting direction to the light source direction, and the optical surface distribution is recorded as S1-S4. For example, S2 is 23.3, which means that the distance value between the second cylindrical mirror and the first cylindrical mirror is 23.3.

[0075] The optical performance simulation results in this case can be shown as Figure 2 As shown, Figure 2 The horizontal axis is the spatial frequency, which mainly refers to the number of grid bars that perform sinusoidal modulation of the brightness of the image or stimulus pattern within each degree of viewing angle, and the unit is line pairs / mm. The vertical axis is the modulation transfer function (MTF). It can be seen that the MTF at different viewing angles is greater than 0.6, and the imaging performance is good.

[0076] In another possible implementation, the ratio of the magnification of the projection module in the Y and Z directions is 1:1.6. That is, the aspect ratio of the projected image is increased by 1.6 times compared with the image source (it can also be understood as the focal length is enlarged by 1.6 times, or the field of view is compressed by a corresponding value, which has a correlation with 1.6, such as a tangent relationship), and the final projection frame aspect ratio is 6.4:1.

[0077] In this case, the optical parameters of each surface of the first cylindrical mirror and the second cylindrical mirror may be as shown in Table 2:

[0078] Table 2

[0079] surface Face type Radius of curvature (R) Center thickness (T) Refractive index(Nd) Abbe number (Vd) S1 cylinder 84.703 10.92 1.49 55.31 S2 cylinder ∞ 50.05 - - S3 cylinder ∞ 5.00 1.53 55.98 S4 cylinder 59.809 4.00 - -

[0080] The cylindrical mirror groups are arranged in order from the light emitting direction to the light source direction, and the optical surface distribution is recorded as S1-S4.

[0081] The optical performance simulation results in this case can be shown as Figure 3 As shown, it can be seen that the MTF at different field angles is greater than 0.5, and the imaging performance is good.

[0082] The lens group 102 has been roughly described above. Figure 4 The specific structure of the lens group 102 is described by taking as an example.

[0083] Take the case where the lens group of the projection lens group is a plurality of circles in the YZ view as an example, Figure 4 As shown, the lens group 102 includes a first lens 1021 , a second lens 1022 , a third lens 1023 and a fourth lens 1024 .

[0084] The first lens 1021 has positive optical power, the second lens 1022 has positive optical power, the third lens 1023 has negative optical power, and the fourth lens 1024 has positive optical power.

[0085] Optionally, it can be seen from the XZ view and the XY view that the first lens 1021 is a concave-convex lens, with a side close to the light source device 101 being a concave surface, and a side away from the light source device 101 being a convex surface. The second lens 1022 is a double convex lens. The third lens 1023 is an aspherical mirror, with a side close to the light source device 101 being a concave surface, and a side away from the light source device 101 being a convex surface. The fourth lens 1024 is an aspherical mirror, with a side close to the light source device 101 being a convex surface, and a side away from the light source device 101 being a convex surface.

[0086] For example, the first lens 1021 is a meniscus-shaped glass spherical mirror, the second lens 1022 is a double-convex glass spherical mirror, the third lens 1023 is a meniscus-shaped plastic aspherical mirror, and the fourth lens 1024 is a double-convex aspherical mirror.

[0087] In addition, when the projection module includes an aperture, the aperture can be set on the surface of the third lens 1023 close to the light source device 101.

[0088] Exemplarily, the optical parameters of each lens in the lens group may be as shown in Table 3 and Table 4:

[0089] Table 3

[0090] surface Face type Radius of curvature (R) Center thickness (T) Refractive index(Nd) Abbe number (Vd) S5 Aspheric 102.598 12.09 1.53 55.98 S6 Aspheric -15.372 1.24 - - S7 Aspheric 15.010 5.44 1.64 23.53 S8 Aspheric 5.485 5.73 - - S9 Spherical 28.465 8.31 1.75 52.34 S10 Spherical -34.707 0.71 - - S11 Spherical 21.415 11.50 1.75 52.34 S12 Spherical 25.737 5.00 - -

[0091] Among them, the lens groups are sorted according to the light emitting direction to the light source direction, and the optical surface distribution is recorded as S5-S12.

[0092] In addition, the expression of the lens aspheric surface is as follows:

[0093]

[0094] Among them, z is the vector height at position r on the aspherical surface, c is the paraxial curvature of the aspherical surface, c=1 / r, r is the radius of curvature, k is the cone coefficient, A~F are high-order coefficients, and the surface coefficients are shown in Table 4 below:

[0095] Table 4

[0096] surface Cone coefficient k A B C D S5 0 -2.4067E-007 -6.3300E-008 3.8495E-011 0 S6 -8.299 -1.9730E-006 -2.9405E-008 2.5255E-011 4.2302E-014 S7 -1.342 -1.2281E-004 3.4554E-007 -4.1012E-010 -1.3888E-013 S8 -2.020 -9.1348E-006 -1.0660E-007 1.1694E-009 -3.1784E-012

[0097] Below Figure 1 The lens group in Figure 4 Take the structure of the projection module as an example to introduce the structure of the projection module. Figure 5 As shown, the projection module includes a light source device 101, a first lens 1021, a second lens 1022, a third lens 1023, a fourth lens 1024, a first cylindrical mirror 1031 and a second cylindrical mirror 1032 which are arranged in sequence on the optical transmission path.

[0098] For the description of each lens and each cylindrical mirror, please refer to the above Figures 1 to 4 The relevant description will not be repeated here.

[0099] The embodiment of the present application also provides a vehicle, which is equipped with any of the above-mentioned projection modules or projection systems. The projection module or projection system includes: a light source device, a lens group, and a cylindrical lens group arranged in sequence on the optical transmission path; the light emitted by the light source device forms a light beam after passing through the lens group, and the light beam is projected to the outside of the vehicle through the cylindrical lens group; the cylindrical lens group is used to adjust the magnification of the light beam on the first axis and the second axis, thereby changing the frame ratio of the light beam projected to the outside, and the first axis, the second axis and the optical axis are perpendicular to each other.

[0100] The embodiment of the present application also provides a vehicle, which is equipped with the above-mentioned Figures 1 to 5 Any kind of projection module. Figure 6 The embodiment of the present application provides a schematic diagram of a projection module installed in a vehicle. Alternatively, it can be understood that the projection module is a part of the vehicle headlight. The vehicle controls the parameters of the cylindrical lens group in the projection module to achieve different image ratios of the light beam projected to the outside. For example, Figure 7 The image ratio on the Y-axis and the Z-axis is shown. It is understandable that the vehicle can project on the wall or the ground through the projection module. Accordingly, the optical axis of the projection module can be parallel to the driving direction of the vehicle (for example, Figure 7 Alternatively, the optical axis of the projection module may be at a certain angle to the direction of travel of the vehicle (i.e. the projection lens group is tilted downward), so that projection display can be performed on the ground area close to the vehicle.

[0101] Optionally, the above-mentioned vehicle further includes a processor, the processor is used to send a control signal to the projection module, and the control signal is used to adjust the cylindrical lens group to achieve the magnification of the light beam on the first axis and the second axis. The projection module can have different magnifications in the horizontal and vertical directions, and the projected image is compressed in the vertical direction, thereby increasing the energy density in the vertical direction and the FOV in the horizontal direction. Compared with the prior art in which the magnification ratios in the horizontal and vertical directions are the same, the projection module provided by the present application can break through the constraints of the aspect ratio of the image source through the cylindrical lens group and achieve an ideal frame ratio. Among them, the processor can be at least one of a processor / controller such as an electronic control unit (ECU) and a body control module (BCM).

[0102] For example, the vehicle may be a car, truck, motorcycle, bus, ship, airplane, helicopter, lawn mower, recreational vehicle, amusement park vehicle, construction equipment, tram, golf cart, train, and cart, etc., which are not particularly limited in the embodiments of the present application. The projection module can be installed on the lighting system of the vehicle (such as car headlights, taillights, brake lights, etc.). It can be used for high and low beam switching and welcoming projection.

[0103] Figure 8 A schematic diagram of a possible functional framework of a vehicle provided in an embodiment of the present application.

[0104] like Figure 8 As shown, the functional framework of the vehicle may include various subsystems, for example, the control system 15, the sensor system 12, one or more peripheral devices 16 (one is shown as an example), the power supply 18, the computer system 20, and the display system 32. Optionally, the vehicle may also include other functional systems, for example, an engine system that provides power for the vehicle, etc., which is not limited in this application.

[0105] The sensor system 12 may include a number of detection devices, which can sense the measured information and convert the sensed information into electrical signals or other required forms of information output according to a certain rule. As shown in the figure, these detection devices may include a global positioning system (GPS), a vehicle speed sensor, an inertial measurement unit (IMU), a radar unit, a laser rangefinder, a camera device, a wheel speed sensor, a steering sensor, a gear position sensor, or other components for automatic detection, etc., and the present application does not limit them.

[0106] The control system 15 may include several components, such as the steering unit, brake unit, lighting system, automatic driving system, map navigation system, network timing system and obstacle avoidance system shown in the figure. Optionally, the control system 15 may also include components such as a throttle processor and an engine processor for controlling the vehicle's speed, which are not limited in this application.

[0107] The peripheral device 16 may include several components, such as the communication system, touch screen, user interface, microphone, and speaker shown in the figure. The communication system is used to realize network communication between the vehicle and other devices other than the vehicle. In practical applications, the communication system may use wireless communication technology or wired communication technology to realize network communication between the vehicle and other devices. The wired communication technology may refer to communication between the vehicle and other devices through network cables or optical fibers.

[0108] The power source 18 represents a system that provides power or energy for the vehicle, which may include but is not limited to a rechargeable lithium battery or a lead-acid battery, etc. In practical applications, one or more battery components in the power source are used to provide power or energy for starting the vehicle, and the type and material of the power source are not limited in this application.

[0109] Several functions of the vehicle are controlled and implemented by the computer system 20. The computer system 20 may include one or more processors 2001 (one processor is shown as an example in the figure) and a memory 2002 (also referred to as a storage device). In actual applications, the memory 2002 is also inside the computer system 20, or it may be outside the computer system 20, for example, as a cache in the vehicle, etc., which is not limited in this application.

[0110] in,

[0111] For the description of the processor 2001, reference may be made to the description of the aforementioned processor 1301. The processor 2001 may include one or more general-purpose processors, such as a graphics processing unit (GPU). The processor 2001 may be used to run the relevant programs or instructions corresponding to the programs stored in the memory 2002 to implement the corresponding functions of the vehicle.

[0112] The memory 2002 may include a volatile memory, such as a RAM; the memory may also include a non-volatile memory, such as a ROM, a flash memory, or a solid state drive (SSD); the memory 2002 may also include a combination of the above-mentioned types of memory. The memory 2002 may be used to store a set of program codes or instructions corresponding to the program codes, so that the processor 2001 calls the program codes or instructions stored in the memory 2002 to implement the corresponding functions of the vehicle. This function includes but is not limited to Figure 8 Some or all of the functions in the vehicle functional framework diagram shown. In this application, the memory 2002 may store a set of program codes for vehicle control, and the processor 2001 calls the program code to control the safe driving of the vehicle. How to achieve safe driving of the vehicle is described in detail below in this application.

[0113] Optionally, in addition to storing program codes or instructions, the memory 2002 may also store information such as road maps, driving routes, sensor data, etc. The computer system 20 may be combined with other elements in the vehicle functional framework diagram, such as sensors in the sensor system, GPS, etc., to implement relevant functions of the vehicle. For example, the computer system 20 may control the driving direction or driving speed of the vehicle based on the data input from the sensor system 12, which is not limited in this application.

[0114] The display system 32 may include several components, such as a processor and the aforementioned Figures 1 to 8 Any one of the projection modules described in . The processor is used to generate an image according to a user instruction and send the image content to the projection module. By adding a cylindrical lens group in the projection module, and adjusting the magnification of the light beam on the first axis and the second axis through the cylindrical lens group. The projection module can have different magnifications in the horizontal and vertical directions, and the projected image is compressed in the vertical direction, thereby improving the longitudinal energy density and the horizontal FOV. Compared with the prior art in which the horizontal and vertical magnification ratios are the same, the projection module provided by the present application can break through the constraints of the aspect ratio of the image source through the cylindrical lens group and achieve an ideal frame ratio. It should be noted that the functions of some components in the display system 32 can also be implemented by other subsystems of the vehicle. For example, the processor can also be a component in the control system 15.

[0115] It is understandable that the projection module may also be located in the lighting system to implement high and low beam lighting and / or projection of the vehicle.

[0116] Among them, this application Figure 8 The four subsystems shown in the figure, sensor system 12, control system 15, computer system 20 and display system 32 are only examples and do not constitute a limitation. In practical applications, vehicles can combine several components in the vehicle according to different functions to obtain subsystems with corresponding different functions. In practical applications, vehicles can include more or fewer systems or components, which is not limited in this application.

[0117] In the description of this specification, specific features, structures, materials or characteristics may be combined in an appropriate manner in any one or more embodiments or examples.

[0118] The above are only specific implementations of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A projection module, characterized in that: The projection module is applied to a vehicle, and comprises: a light source device, a lens group and a cylindrical lens group arranged in sequence on an optical transmission path; The light emitted by the light source device forms a light beam after passing through the lens group, and the light beam is projected to the outside of the vehicle through the cylindrical lens group; The cylindrical lens group is used to adjust the magnification of the light beam on the first axis and the second axis, so as to change the frame ratio of the light beam projected to the outside. The first axis, the second axis and the optical axis are perpendicular to each other.

2. The projection module according to claim 1, characterized in that: The modulation transfer function MTF of the projection module is greater than or equal to a first preset threshold, and / or the aperture coefficient FNO of the projection module is less than or equal to a second preset threshold.

3. The projection module according to claim 2, characterized in that: The first preset threshold is greater than or equal to 0.5, and the second preset threshold is less than or equal to 1.

5.

4. The projection module according to any one of claims 1 to 3, characterized in that: The parameters of the cylindrical lens group are related to the magnification, and the parameters include at least one of the following: a distance between at least two cylindrical lenses in the cylindrical lens group, and an optical power of the cylindrical lenses in the cylindrical lens group.

5. The projection module according to any one of claims 1 to 4, characterized in that: The cylindrical mirror group includes a first cylindrical mirror and a second cylindrical mirror arranged in sequence on the optical transmission path, the first cylindrical mirror has a negative optical focal length, and the second cylindrical mirror has a positive optical focal length.

6. The projection module according to claim 5, characterized in that: The side of the first cylindrical mirror close to the light source device is a concave surface, and the side of the first cylindrical mirror away from the light source device is a flat surface; the side of the second cylindrical mirror close to the first cylindrical mirror is a flat surface, and the side of the second cylindrical mirror away from the first cylindrical mirror is a convex surface.

7. The projection module according to claim 5 or 6, characterized in that: The focal length of the first cylindrical mirror on the optical axis is f1, the focal length of the second cylindrical mirror on the optical axis is f2, and the equivalent focal length of the projection module on the optical axis is f x , and f x <f1-f2<2f x .

8. The projection module according to any one of claims 1 to 7, characterized in that: The center thickness of the first cylindrical mirror is a first thickness, the center thickness of the second cylindrical mirror is a second thickness, and the ratio of the second thickness to the first thickness is less than 4.5 mm and greater than 2 mm.

9. The projection module according to any one of claims 1 to 8, characterized in that: The cylindrical lens group is detachably connected to the lens group.

10. The projection module according to any one of claims 1 to 9, characterized in that: The light source device and the lens group are rotationally symmetrical structures.

11. The projection module according to any one of claims 1 to 10, characterized in that: The cross-sections of the lens group and the cylindrical lens group along the optical axis are circular or polygonal.

12. The projection module according to any one of claims 1 to 11, characterized in that: A ratio of the magnification of the light beam on the first axis to the magnification of the light beam on the second axis is in a first interval, and the first interval includes 1.2 to 1.

7.

13. The projection module according to any one of claims 1 to 12, characterized in that: The light source device includes a light source and a projection element. The light source includes at least one of the following: a light emitting diode (LED), a laser diode (LD), and a micro light emitting diode display (MicroLED). The projection element includes at least one of the following: a liquid crystal display (LCD), a liquid crystal on silicon (LCOS), and a digital micromirror device (DMD).

14. A means of transport, characterized in that: The projection module comprises the projection module according to any one of claims 1 to 13, wherein the projection module is installed on the vehicle.

15. The vehicle according to claim 14, characterized in that: The vehicle also includes a processor, which is used to send a control signal to the projection module. The control signal is used to adjust the magnification of the light beam on the first axis and the second axis, thereby changing the frame ratio of the light beam projected to the outside. The first axis, the second axis and the optical axis are perpendicular to each other.

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