Projection system and method of manufacturing the same

Abstract

The application provides a projection system and a manufacturing method thereof. The projection system comprises: a projection image generator generating a projection image; an imaging lens group comprising at least one lens with optical power; and a projection adjuster comprising at least one lens with optical power. The projection image is projected on an imaging surface of the projection system through the imaging lens group and the projection adjuster. The projection system satisfies: f Ax ≠ f Ay , wherein f Ax is the overall effective focal length of the projection adjuster in the x-axis direction, and f Ay is the overall effective focal length of the projection adjuster in the y-axis direction different from the x-axis direction.

Description

Technical Field

[0001] This application relates to the field of optical elements, and more specifically, to projection systems comprising multiple lenses. Background Technology

[0002] With the development of science and technology, more and more fields require optical lenses to act as "eyes," such as automotive, surveillance, projection, and industrial applications. As demand grows and technology advances, the requirements for optical lens performance are becoming increasingly diverse. For example, projection display systems are used in vehicles to improve driving safety and convenience.

[0003] In automotive projection systems, the optical lenses typically project directly onto a diffuser surface. However, the aspect ratio of the image projected onto the imaging surface is usually determined directly by the image sensor chip, typically 2:1. Therefore, there may be situations where the aspect ratio of the diffuser imaging surface does not match the aspect ratio of the chip.

[0004] To address this issue, related technologies, when the image size is fixed, can only employ either a compressed lens solution or a combination of compressed lenses and pixel cropping. However, both solutions have drawbacks. For example, with the compressed lens solution, to ensure overall image quality, the performance of the imaging lens is typically optimized by adding more freeform mirrors; however, freeform mirrors are difficult to manufacture, leading to increased processing costs. With the pixel cropping solution, the pixels of the image generation unit cannot be fully utilized, resulting in a loss of light efficiency. Summary of the Invention

[0005] According to one aspect of this application, a projection system is provided. The projection system includes: a projection image generator for generating a projection image; an imaging lens group including at least one lens having optical power; and a projection adjuster including at least one lens having optical power. The projection image is projected onto the imaging surface of the projection system via the imaging lens group and the projection adjuster. The projection system satisfies: f Ax ≠f Ay , where f Ax It is the overall effective focal length of the projection adjuster along the x-axis, f Ay It is the overall effective focal length of the projection adjuster in the y-axis direction, which is different from the x-axis direction.

[0006] In one implementation, 0 < f Ax / f Ay <1, where f Ax It is the overall effective focal length of the projection adjuster along the x-axis, f AyIt is the overall effective focal length of the projection adjuster in the y-axis direction, which is different from the x-axis direction.

[0007] In one embodiment, at least one lens included in the projection adjuster may be a cylindrical mirror or a freeform mirror.

[0008] In one embodiment, the projection adjuster may be disposed between the imaging lens group and the imaging surface of the projection system.

[0009] In one embodiment, the overall effective focal length f of the projection adjuster in the x-axis direction is... Ax It can satisfy -500mm≤f Ax ≤-50mm, and the overall effective focal length f of the projection adjuster in the y-axis direction. Ay It can satisfy -500mm≤f Ay ≤-50mm.

[0010] In one implementation, the projection system can satisfy: 4≤|f Ax / f S |≤10 and 4≤|f Ay / f S |≤10, where f S It is the overall effective focal length of the imaging lens group.

[0011] In one implementation, the projection system can satisfy: -15 ≤ f Ax / D S ≤-5 and -15≤f Ay / D S ≤-5, where D S It is the maximum aperture of the lens that is closest to the projection adjuster in the imaging lens group.

[0012] In one embodiment, the projection adjuster may be positioned between the imaging lens group and the projection image generator.

[0013] In one embodiment, the effective focal length f of the projection adjuster in the x-axis direction is... Ax It can satisfy 10mm≤f Ax ≤100mm, and the effective focal length f of the projection adjuster in the y-axis direction. Ay It can satisfy 10mm≤f Ay ≤100mm.

[0014] In one implementation, the projection system can satisfy: 0.5 ≤ |f Ax / f S |≤5 and 0.5≤|f Ay / f S |≤5, where f SIt is the overall effective focal length of the imaging lens group.

[0015] In one implementation, the projection system can satisfy: 1.5 ≤ f Ax / D S ≤3.5 and 1.5≤f Ay / D S ≤3.5, where D S It is the maximum aperture of the lens that is closest to the projection adjuster in the imaging lens group.

[0016] In one implementation, the projection system can satisfy: 1.6 ≤ D A / L AS ≤4.7, where D A It is the maximum light-transmitting full aperture of the projector regulator, L AS It is the on-axis distance between the projection adjuster and the imaging lens group.

[0017] In one embodiment, the projection adjuster includes a first sub-projection adjuster and a second sub-projection adjuster, wherein the first sub-projection adjuster is disposed between the imaging lens group and the imaging surface of the projection system, and the second sub-projection adjuster is disposed between the imaging lens group and the projection image generator.

[0018] In one implementation, the overall effective focal length f of the first sub-projection adjuster in the x-axis direction is... A1x Satisfy -500mm≤f A1x ≤-50mm, the overall effective focal length f of the first sub-projection adjuster in the y-axis direction A1y Satisfy -500mm≤f A1y ≤-50mm; and the effective focal length f of the second sub-projection adjuster in the x-axis direction. A2x Satisfying 10mm≤f A2x ≤100mm, the effective focal length f of the second sub-projection adjuster in the y-axis direction A2y Satisfying 10mm≤f A2y ≤100mm.

[0019] In one implementation, the first sub-projection adjuster satisfies: -15 ≤ f A1x / D S1 ≤-5 and -15≤f A1y / D S1 ≤-5, where D S1 It is the maximum aperture of the lens in the imaging lens group that is closest to the first sub-projector adjuster, f A1x It is the overall effective focal length of the first sub-projection adjuster in the x-axis direction, f A1yIt is the overall effective focal length of the first sub-projection adjuster in the y-axis direction; and the second sub-projection adjuster satisfies: 1.5 ≤ f A2x / D S2 ≤3.5 and 1.5≤f A2y / D S2 ≤3.5, where D S2 It is the maximum aperture of the lens in the imaging lens group that is closest to the second sub-projector, f. A2x It is the overall effective focal length of the second sub-projection adjuster in the x-axis direction, f A2y It is the overall effective focal length of the second sub-projection adjuster in the y-axis direction.

[0020] According to another aspect of this application, a head-up display system is provided. This head-up display system includes the projection system provided in this application.

[0021] According to another aspect of this application, an intelligent headlight projection system is provided. This intelligent headlight projection system includes the projection system provided in this application.

[0022] According to another aspect of this application, a method for manufacturing a projection system is provided. The method includes: preparing a projection image generator configured to generate a projected image; preparing an imaging lens group including at least one lens having optical power; preparing a projection adjuster including at least one lens having optical power; and assembling the projection image generator, the imaging lens group, and the projection adjuster together. The projection adjuster is assembled between the imaging lens group and the projection image generator and / or between the imaging lens group and the imaging surface of the projection system. Preparing the projection adjuster includes: forming the overall effective focal length of the projection adjuster in the x-axis direction and the overall effective focal length in the y-axis direction, which is different from the x-axis direction, so that they are different from each other.

[0023] The projection system provided in this application may include a projection adjuster to adjust the aspect ratio of the image projected onto the imaging surface to adapt it to the imaging surface (e.g., a diffuser surface). The projection adjuster may include a cylindrical mirror or a freeform mirror to allow the projection system to have different magnifications in the meridional and sagittal directions.

[0024] The projection system according to this application can be independently installed outside the imaging lens group included in the projection system, for example, installed as an external device at the front end of the optical path and / or at the rear end of the optical path of the imaging lens group. Therefore, different projection adjusters can be selected specifically according to the aspect ratio of the imaging surface to meet the needs of projection surfaces with different aspect ratios.

[0025] The projection adjuster according to this application can scale a projected image with an aspect ratio of 2:1 to one with an aspect ratio ranging from 1:1 to 4:1. This allows for changing the projection size while avoiding high costs and pixel loss, achieving specific imaging surface size matching. Attached Figure Description

[0026] Other features, objects, and advantages of this utility application will become more apparent from the following detailed description of the embodiments, taken in conjunction with the accompanying drawings. In the drawings:

[0027] Figure 1 A schematic diagram of the projection system according to a comparative embodiment is shown;

[0028] Figure 2 An example diagram of a projected image projected onto an imaging plane according to a comparative embodiment is shown;

[0029] Figure 3 A schematic diagram of the projection system according to the first embodiment of this application is shown;

[0030] Figure 4 A schematic structural diagram of a projection adjuster according to a first embodiment of this application is shown;

[0031] Figure 5 An example diagram of a projected image projected onto an imaging plane according to a first embodiment of this application is shown;

[0032] Figure 6 A schematic diagram of the projection system according to a second embodiment of this application is shown;

[0033] Figure 7 A schematic structural diagram of a projection adjuster according to a second embodiment of this application is shown;

[0034] Figure 8 A schematic diagram of the projection system according to a third embodiment of this application is shown; and

[0035] Figure 9 A schematic structural diagram of a projection adjuster according to a third embodiment of this application is shown. Detailed Implementation

[0036] To better understand this application, various aspects of this application will be described in more detail with reference to the accompanying drawings. It should be understood that these detailed descriptions are merely illustrative of exemplary embodiments of this application and are not intended to limit the scope of this application in any way. Throughout the specification, the same reference numerals refer to the same elements. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

[0037] It should be noted that in this specification, the terms "first," "second," "third," etc., are used only to distinguish one feature from another and do not imply any limitation on the features. Therefore, without departing from the teachings of this application, the first lens discussed below may also be referred to as the second lens or the third lens.

[0038] In the accompanying drawings, the thickness, size, and shape of the lenses have been slightly exaggerated for ease of illustration. Specifically, the shapes of the spherical or aspherical surfaces shown in the drawings are illustrated by way of example. That is, the shapes of the spherical or aspherical surfaces are not limited to those shown in the drawings. The drawings are for illustrative purposes only and are not strictly to scale.

[0039] In this document, the paraxial region refers to the region near the optical axis. If the lens surface is convex and the location of the convexity is not defined, it means that the lens surface is convex at least in the paraxial region; if the lens surface is concave and the location of the concaveness is not defined, it means that the lens surface is concave at least in the paraxial region. The surface of each lens closest to the first side is called the first side surface of the lens, and the surface of each lens closest to the second side is called the second side surface of the lens. For example, in the projection system of this application, the first side may be the imaging side, and the second side may be the image source side.

[0040] In this paper, the direction parallel to the optical axis is defined as the z-axis direction, the direction perpendicular to the z-axis and located in the meridional plane is defined as the y-axis direction, and the direction perpendicular to the z-axis and located in the sagittal plane is defined as the x-axis direction.

[0041] It should also be understood that the terms "comprising," "including," "having," "containing," and / or "comprising" as used in this specification indicate the presence of the stated features, elements, and / or components, but do not exclude the presence or addition of one or more other features, elements, components, and / or combinations thereof. Furthermore, when describing embodiments of this application, the word "may" is used to mean "one or more embodiments of this application." And the term "exemplary" is intended to refer to an example or illustration.

[0042] Unless otherwise specified, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. It should also be understood that terms (e.g., those defined in common dictionaries) shall be interpreted as having the meaning consistent with their meaning in the context of the relevant art and shall not be interpreted in an idealized or overly formal sense unless expressly so specified herein.

[0043] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0044] The features, principles and other aspects of this application are described in detail below.

[0045] In an exemplary embodiment, the projection system according to this application may include: a projection image generator for generating a projection image; an imaging lens group including at least one lens having optical power; and a projection adjuster including at least one lens having optical power.

[0046] According to an exemplary embodiment of this application, the lens included in the projection adjuster may be a cylindrical lens or a freeform lens. The cylindrical lens or freeform lens may include a cylinder or freeform surface that may have different radii of curvature and / or focal lengths in the x-axis and y-axis directions, so that the image projected therethrough has different magnifications in the x-axis and y-axis directions, thereby changing the aspect ratio of the image projected onto the imaging surface (e.g., a diffuser surface).

[0047] As those skilled in the art will understand, a freeform surface can be, for example, a non-rotationally symmetric aspheric surface, which, based on a rotationally symmetric aspheric surface, adds a non-rotationally symmetric component. Therefore, its parameters such as radius of curvature and focal length in the meridional and sagittal directions can be different. Introducing a non-rotationally symmetric aspheric surface into a conventional imaging lens system is beneficial for effectively correcting off-axis meridional and sagittal aberrations, greatly improving the performance of the optical system. In the projection adjuster of this application, this asymmetric freeform surface is introduced to change the aspect ratio of the image projected by the existing imaging lens group, so as to adapt it to the aspect ratio of the imaging surface (e.g., a diffuser surface).

[0048] According to an exemplary embodiment of this application, the projection adjuster may be mounted at the front end and / or the rear end of the optical path of the imaging lens assembly. In this document, "front end of optical path" means in front of the element along the direction of light travel, while "rear end of optical path" means behind the element along the direction of light travel.

[0049] According to an exemplary embodiment of this application, the projection adjuster can be installed without changing the inherent layout of the imaging lens group used for projection imaging, and the assembly process is simple and convenient to operate. In addition, different aspect ratio scaling effects can be achieved by replacing different projection adjusters, thereby allowing for the targeted selection of a matching projection adjuster for different imaging surface (e.g., diffuser surface) sizes.

[0050] According to an exemplary embodiment of this application, the lens included in the projection adjuster can be configured to have different focal lengths in the x-axis and y-axis directions. Exemplarily, the projection system satisfies: f Ax ≠f Ay , where f AxIt is the overall effective focal length of the projection adjuster along the x-axis, f Ay This is the overall effective focal length of the projection adjuster in the y-axis direction. Therefore, the projected image has different magnifications in the x-axis and y-axis directions, thus allowing the aspect ratio of the image projected onto the imaging surface (e.g., a diffuser surface) to be changed.

[0051] According to an exemplary embodiment of this application, the projection system satisfies: 0 ≤ f Ax / f Ay ≤1, where f Ax It is the overall effective focal length of the projection adjuster along the x-axis, f Ay It is the overall effective focal length of the projection adjuster along the y-axis. It satisfies the condition 0 ≤ f. Ax / f Ay A value of ≤1 allows the projection system to control the magnification in the x-axis direction to be less than that in the y-axis direction. This allows the projected image to be further stretched in the y-axis direction and further compressed in the x-axis direction, thereby further increasing the aspect ratio of the projected image.

[0052] For example, when the projection adjuster is installed at the front end of the optical path of the imaging lens group, the projection system can satisfy: -500mm≤f Ax ≤-50mm and -500mm≤f Ay ≤-50mm, where f Ax It is the overall effective focal length of the projection adjuster along the x-axis, f Ay This is the overall effective focal length of the projection adjuster along the y-axis. In this case, with the imaging lens group remaining constant, the smaller the focal length of the projection adjuster, the larger the overall effective focal length of the projection system can be, and the smaller the change in the aspect ratio of the projected image.

[0053] For example, when the projection adjuster is installed at the rear end of the optical path of the imaging lens group, the projection system can satisfy: 10mm ≤ f Ax ≤100mm, and 10mm≤f Ay ≤100mm, where f Ax It is the overall effective focal length of the projection adjuster along the x-axis, f Ay This refers to the overall effective focal length of the projection adjuster along the y-axis. In this case, with the imaging lens group remaining constant, the smaller the focal length of the projection adjuster, the smaller the overall effective focal length of the projection system can be, and the greater the change in the aspect ratio of the projected image. Furthermore, the projection system can satisfy: 10mm ≤ f Ax ≤40mm, and 10mm≤f Ay ≤40mm.

[0054] According to an exemplary embodiment, the projection system can satisfy: 10mm≤f≤80mm, where f is the total effective focal length of the projection system.

[0055] According to an exemplary embodiment, when the projection adjuster is installed at the front end of the optical path of the imaging lens group, the projection system can satisfy: 4≤|f Ax / f S |≤10 and 4≤|f Ay / f S |≤10, where f Ax It is the overall effective focal length of the projection adjuster along the x-axis, f Ay It is the overall effective focal length of the projection adjuster in the y-axis direction, f S This is the overall effective focal length of the imaging lens group. If the projection system satisfies this condition, it can guarantee the focal length variation in the x-axis and y-axis directions, thereby improving the overall compression or expansion ratio to achieve a projected image with a suitable aspect ratio.

[0056] According to an exemplary embodiment, when the projection adjuster is installed at the front end of the optical path of the imaging lens group, the projection system can satisfy: -15≤f Ax / D S ≤-5 and -15≤f Ay / D S ≤-5, where f Ax It is the overall effective focal length of the projection adjuster along the x-axis, f Ay D is the overall effective focal length of the projection adjuster in the y-axis direction. S This is the maximum aperture of the lens in the imaging lens group that is closest to the projection regulator. When the projection regulator is installed at the front end of the optical path of the imaging lens group, the projection system satisfies this condition, which allows the focal length of the projection regulator to be controlled to be negative and its absolute value to be greater than the maximum aperture of the lens in the imaging lens group that is closest to the projection regulator. This is beneficial for the coordination between the imaging lens group and the projection regulator.

[0057] According to an exemplary embodiment, when the projection adjuster is installed at the rear end of the optical path of the imaging lens group, the projection system can satisfy: 0.5 ≤ |f Ax / f S |≤5 and 0.5≤|f Ay / f S |≤5, where f Ax It is the overall effective focal length of the projection adjuster along the x-axis, f Ay It is the overall effective focal length of the projection adjuster in the y-axis direction, f SThis is the overall effective focal length of the imaging lens group. If the projection system satisfies this condition, it can guarantee the focal length variation in the x-axis and y-axis directions, thereby improving the overall compression or expansion ratio to achieve a projected image with a suitable aspect ratio.

[0058] According to an exemplary embodiment, when the projection adjuster is installed at the rear end of the optical path of the imaging lens group, the projection system can satisfy: 1.5 ≤ f Ax / D S ≤3.5 and 1.5≤f Ay / D S ≤3.5, where f Ax It is the overall effective focal length of the projection adjuster along the x-axis, f Ay D is the overall effective focal length of the projection adjuster in the y-axis direction. S This is the maximum aperture of the lens in the imaging lens group that is closest to the projection regulator. When the projection regulator is installed at the rear end of the optical path of the imaging lens group, the projection system satisfies this condition, which allows the focal length of the projection regulator to be controlled to be positive and its absolute value to be less than the maximum aperture of the lens in the imaging lens group that is closest to the projection regulator. This is beneficial for the matching between the imaging lens group and the projection regulator.

[0059] According to an exemplary embodiment, the projection system can satisfy: 1.6 ≤ D A / L AS ≤4.7, where D A It is the maximum light-transmitting full aperture of the projector regulator, L AS D is the on-axis distance between the projection adjuster and the imaging lens group. A / L AS This can represent the tangent of the angle of the light rays emitted from the imaging lens group, and the projection system satisfies 1.6 ≤ D. A / L AS A value ≤4.7 is beneficial for controlling the exit angle of the imaging lens group between 0° and 100°, ensuring the matching between the projection adjuster and the imaging lens group. For example, compared to the case where the projection adjuster is installed at the rear end of the optical path of the imaging lens group, when the projection adjuster is installed at the front end of the optical path of the imaging lens group, the aperture of the projection adjuster can be set to be larger.

[0060] According to the embodiments of this application, both cylindrical mirrors and freeform mirrors can be used to change the aspect ratio of the projected image. When the aspect ratio magnification requirement is low, only the dimension in the x-axis and y-axis directions needs to be changed, in which case the aspect ratio of the projected image can be in the range of 1.5:1 to 3:1. When the aspect ratio magnification requirement is high, the dimensions in both the x-axis and y-axis directions can be changed simultaneously, in which case the aspect ratio of the projected image can be in the range of 1:1 to 4:1.

[0061] The following provides a conventional projection system including a common imaging lens group as a comparative embodiment, and based on this comparative embodiment, the effect of the projection adjuster according to this application on the aspect ratio of the projected image is explained.

[0062] Comparative Examples

[0063] First, refer to Figure 1 and Figure 2 A projection system according to a comparative embodiment will be described. Figure 1 A schematic diagram of the projection system according to a comparative embodiment is shown. Figure 2 An example diagram of a projected image projected onto an imaging plane according to a comparative embodiment is shown.

[0064] like Figure 1 As shown, the projection system 1000 according to the comparative embodiment may include a projection image generator (not shown) disposed at the image source plane SS, and an imaging lens group 100 disposed between the image source plane SS and the imaging plane SI. Further, the projection system 1000 may also include a prism 200 and a protective member or filter 300 disposed between the imaging lens group 100 and the image source plane SS. In the comparative embodiment, an image generated from the projection image generator can be projected onto the imaging plane SI sequentially through the protective member or filter 300, the prism 200, and the imaging lens group 100.

[0065] According to one example of a comparative embodiment, the imaging lens group 100 may sequentially include a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, and a sixth lens L6 along the optical axis (e.g., the z-axis) from the imaging plane SI to the image source plane SS.

[0066] According to one example of a comparative embodiment, each of the first lens L1, second lens L2, third lens L3, fourth lens L4, fifth lens L5, and sixth lens L6 of the imaging lens group 100 may comprise a glass material. However, this is only an example, and the individual lenses of the imaging lens group 100 may also be made of other materials.

[0067] According to one example of a comparative embodiment, each of the first lens L1, second lens L2, third lens L3, fourth lens L4, fifth lens L5, and sixth lens L6 of the imaging lens group 100 may be a rotationally symmetric lens. Exemplarily, each surface of each lens included in the imaging lens group 100 may be a rotationally symmetric spherical or aspherical surface, and this application is not limited thereto.

[0068] According to the comparative embodiment, the imaging lens group 100 can satisfy: 30mm ≤ f S ≤80mm, where fS This is the overall effective focal length of the imaging lens group 100. For example, the overall effective focal length f of the imaging lens group 100... S It is approximately 37mm.

[0069] According to comparative embodiments, such as Figure 2 As shown, the image IMG projected onto the imaging plane SI can have a length Wy in the y-axis direction and a width Wx in the x-axis direction. For example, the length Wy can be about 107 mm, the width Wx can be about 53 mm, and the aspect ratio of the image IMG can be about Wy:Wx = 2:1.

[0070] According to a comparative embodiment, the light emission angle βy in the y-axis direction can be approximately 20°, and the light emission angle βx in the x-axis direction can be approximately 10°.

[0071] Example 1

[0072] The following is for reference Figures 3 to 5 A projection system according to a first embodiment of this application is described. Figure 3 A schematic diagram of the projection system 1000_1 according to the first embodiment of this application is shown.

[0073] like Figure 3 As shown, the projection system 1000_1 according to an exemplary embodiment of this application may sequentially include, from the image source plane SS to the imaging plane SI, a projection image generator (not shown), an imaging lens group 100, and a projection adjuster 400. Further, the projection system 1000_1 may also include a prism 200 and a protective member or filter 300 disposed between the imaging lens group 100 and the image source plane SS.

[0074] According to the first embodiment of this application, the image generated from the projection image generator can be projected onto the imaging surface SI in sequence through the protective member or filter 300, prism 200, imaging lens group 100 and projection adjuster 400.

[0075] According to a first embodiment of this application, a projection image generator can be disposed at the image source plane SS and can be configured to generate a projection image. Exemplarily, the projection image generator may include an illumination unit and a DMD chip.

[0076] According to a first embodiment of this application, the imaging lens group 100 may be the same imaging lens group 100 described according to the comparative embodiment, which may include at least one lens with optical power, for example, it may include six lenses (i.e., first lens L1, second lens L2, third lens L3, fourth lens L4, fifth lens L5, and sixth lens L6). For ease of description, the imaging lens group 100 is described with the case of including six lenses; however, it should be understood that this is only an example, and the projection system 1000_1 may include any other number of lenses as the imaging lens group 100. This is not the focus of this application, and for the sake of brevity, it will not be elaborated upon.

[0077] The difference between the projection system 1000_1 according to the first embodiment of this application and the projection system 1000 according to the comparative embodiment is that the projection system 1000_1 further includes a projection adjuster 400, which can adjust the aspect ratio of the projected image projected on the imaging surface SI according to its own lens configuration, so as to match the size of the imaging surface SI (e.g., a diffuser surface).

[0078] According to the first embodiment of this application, the projection adjuster 400 can be installed between the imaging lens group 100 and the imaging surface SI. In this case, the projection adjuster 400 can be regarded as an external device installed outside the projection system 1000 according to the comparative example. Thus, the aspect ratio of the projected image projected by the projection system 1000 onto the imaging surface SI can be adjusted without changing the inherent projection structure.

[0079] The following will be referenced Figure 4 The specific structure and configuration of the projection adjuster 400 according to the first embodiment will be described in detail. Figure 4 A schematic structural diagram of a projection adjuster 400 according to a first embodiment of this application is shown.

[0080] According to the first embodiment of this application, the projection adjuster 400 may sequentially include a first lens E1, a second lens E2, a third lens E3, and a fourth lens E4 from the imaging surface S1 to the image source surface SS. Specifically, the first lens E1 is a biconvex lens with positive optical power, its first side surface S1 is convex, and its second side surface S2 is convex. The second lens E2 is a biconcave lens with negative optical power, its first side surface S2 is concave, and its second side surface S3 is concave. The third lens E3 is a biconcave lens with negative optical power, its first side surface S4 is concave, and its second side surface S5 is concave. The fourth lens E4 is a biconvex lens with positive optical power, its first side surface S5 is convex, and its second side surface S6 is convex. Light from the projection image generator (or the image source surface SS) sequentially passes from the second side surface S6 of the fourth lens E4 through the first side surface S1 of the first lens E1, and is finally imaged on the imaging surface S1.

[0081] Optionally, the first lens E1 and the second lens E2 are cemented together to form a first cemented lens, as are the third lens E3 and the fourth lens E4. The first and second cemented lenses form a symmetrical structure, which is beneficial for correcting spherical aberration, chromatic aberration, and other problems generated by the individual lenses included in the projection adjuster. Using cemented lenses in optical lenses can improve image quality and reduce light energy reflection loss, thereby achieving high resolution and improving the sharpness of the image. Furthermore, the use of the first and second cemented lenses can simplify the assembly process in the manufacturing of the projection system.

[0082] According to the first embodiment of this application, each of the first lens E1, the second lens E2, the third lens E3 and the fourth lens E4 can be a cylindrical mirror, and its effective focal length and radius of curvature in the x-axis direction and y-axis direction can be different, so that the projection system 1000_1 including the projection adjuster 400 can have different magnifications in the x-axis direction and y-axis direction, thereby changing the aspect ratio of the image projected on the imaging surface.

[0083] Table 1 shows the radius of curvature R of each lens in the y-axis direction of the projection adjuster 400 of the first embodiment. y Thickness / distance d, refractive index Nd, and Abbe number Vd. It should be understood that, taking the first lens L1 as an example, the thickness / distance d of the row where S1 is located is the center thickness d1 of the first lens E1, the thickness / distance d of the row where S2 is located is the distance between the first lens E1 and the second lens E2 on the optical axis, and so on.

[0084]

[0085]

[0086] Table 1

[0087] As shown in Table 1, in the first embodiment, the first and second side surfaces of any one of the first lens E1, the second lens E2, the third lens E3, and the fourth lens E4 are cylindrical surfaces. The shape of the cylindrical surface can be defined using, but is not limited to, the following formula:

[0088]

[0089] Where z is the sag of the surface parallel to the z-axis; c x c y Let be the curvature of the paraxial region along the x-axis and y-axis, respectively (=1 / radius of curvature); k x k y These are the conic coefficients in the x-axis and y-axis directions, respectively; x represents the maximum aperture in the x-axis direction; and y represents the maximum aperture in the y-axis direction.

[0090] Cylindrical lenses can have different radii of curvature in the x-axis and y-axis directions. In this application, to ensure image quality, the cylindrical lens has a valid radius of curvature only in one of the meridional and sagittal directions, while the radius of curvature in the other direction is set to infinity. For example, in this first embodiment, only the radius of curvature in the y-axis direction is set to a valid value, while the radius of curvature in the x-axis direction is set to infinity. It should be understood that having an infinite radius of curvature in one direction means that the curvature in that direction is 0.

[0091] In the first embodiment, the first lens E1 of the projection adjuster 400 may comprise a material having a high refractive index and a low Abbe number. Specifically, the refractive index Nd1 of the first lens E1 may satisfy 1.7 ≤ Nd1 ≤ 1.9, for example, Nd1 = 1.72. Specifically, the Abbe number Vd1 of the first lens E1 may satisfy 25 ≤ Vd1 ≤ 40, for example, Vd1 = 29.5.

[0092] In the first embodiment, the second lens E2 of the projection adjuster 400 may comprise a material with a low refractive index and a high Abbe number. Specifically, the refractive index Nd2 of the second lens E2 may satisfy 1.4 ≤ Nd2 ≤ 1.7, for example, Nd2 = 1.5. Specifically, the Abbe number Vd2 of the second lens E2 may satisfy 40 ≤ Vd2 ≤ 70, for example, Vd2 = 67.

[0093] In the first embodiment, the third lens E3 of the projection adjuster 400 may comprise a material with a high refractive index and a low Abbe number. Specifically, the refractive index Nd3 of the third lens E3 may satisfy 1.7 ≤ Nd3 ≤ 1.9, for example, Nd3 = 1.67. Specifically, the Abbe number Vd3 of the third lens E3 may satisfy 25 ≤ Vd3 ≤ 40, for example, Vd3 = 32.2.

[0094] In the first embodiment, the fourth lens E4 of the projection adjuster 400 may comprise a material having a low refractive index and a high Abbe number. Specifically, the refractive index Nd4 of the fourth lens E4 may satisfy 1.4 ≤ Nd4 ≤ 1.7, for example, Nd4 = 1.59. Specifically, the Abbe number Vd4 of the fourth lens E4 may satisfy 40 ≤ Vd4 ≤ 70, for example, Vd4 = 61.3.

[0095] According to the first embodiment, the projection system 1000_1 can satisfy: -200mm≤f12≤-50mm, where f12 is the combined focal length of the first lens E1 and the second lens E2 of the projection adjuster 400 in the y-axis direction.

[0096] The projection system 1000_1 according to the first embodiment can satisfy: 50mm≤f34≤250mm, where f34 is the combined focal length of the third lens E3 and the fourth lens E4 of the projection adjuster 400 in the y-axis direction.

[0097] According to the projection system 1000_1 of the first embodiment, the following condition can be met: 0≤|f34 / f12|≤5, where f12 is the combined focal length of the first lens E1 and the second lens E2 of the projection adjuster 400 in the y-axis direction, and f34 is the combined focal length of the third lens E3 and the fourth lens E4 of the projection adjuster 400 in the y-axis direction.

[0098] The projection system 1000_1 according to the first embodiment can satisfy: f Ay ≤-200mm, where f Ay It is the overall effective focal length of the projection adjuster 400 in the y-axis direction.

[0099] According to the projection system 1000_1 of the first embodiment, the following condition can be satisfied: 4≤|f Ay / f S |≤10, where f Ay It is the overall effective focal length of the projection adjuster 400 in the y-axis direction, f S It is the overall effective focal length of the imaging lens group 100.

[0100] Compared to the comparative embodiments, the image projected onto the imaging plane SI by the projection system 1000_1 according to the first embodiment of this application can be stretched in the y-axis direction while remaining unchanged in the x-axis direction.

[0101] Figure 5 An example diagram of a projected image projected onto an imaging surface according to a first embodiment of this application is shown.

[0102] According to the first embodiment of this application, as Figure 5 As shown, the image IMG_1 projected onto the imaging plane SI can have a length Wy_1 in the y-axis direction and a width Wx_1 in the x-axis direction. For example, the length Wy_1 can be about 140 mm, the width Wx_1 can be about 53 mm, and the aspect ratio of the image IMG_1 can be about Wy:Wx = 2.65:1.

[0103] According to the first embodiment of this application, the light emission angle βy in the y-axis direction can be about 26.5°, and the light emission angle βx in the x-axis direction can be about 10°.

[0104] For example, such as Figure 5 The image stretching shown can be corrected and restored through post-processing algorithms, thus ensuring that the image ratio can be changed without pixel loss.

[0105] In this first embodiment, for ease of description, only an example is shown where the radius of curvature in the y-axis direction is set to a valid value so that the projected image can be stretched in the y-axis direction relative to the comparative embodiment. However, it should be understood that in other embodiments, the radius of curvature in the y-axis direction can also be adjusted to compress the projected image in the y-axis direction relative to the comparative embodiment. Similarly, in other embodiments, the radius of curvature in the x-axis direction can be set to a valid value so that the projected image can be stretched or compressed in the x-axis direction relative to the comparative embodiment, or the radii of curvature in the x-axis and y-axis directions can be set to different valid values ​​so that the projected image can be stretched or compressed in both the x-axis and y-axis directions relative to the comparative embodiment.

[0106] Example 2

[0107] The following is for reference Figures 6 to 7 A projection system according to a second embodiment of this application is described. Figure 6 A schematic diagram of the projection system 1000_2 according to a second embodiment of this application is shown.

[0108] like Figure 6 As shown, the projection system 1000_2 according to an exemplary embodiment of this application may sequentially include, from the image source plane SS to the imaging plane SI: a projection image generator (not shown), a projection adjuster 400_1, and an imaging lens group 100. Similar to Embodiment 1, the projection system 1000_2 may further include a prism 200 and a protective member or filter 300 disposed between the imaging lens group 100 and the image source plane SS.

[0109] According to the second embodiment of this application, the image generated from the projection image generator can be projected onto the imaging surface SI in sequence through the protective member or filter 300, prism 200, projection adjuster 400_1 and imaging lens group 100.

[0110] The configuration of the projection image generator and imaging lens group 100 according to the second embodiment is the same as that according to the first embodiment and the comparative embodiment. For the sake of simplicity, redundant descriptions will not be provided here, and the focus will be on describing the differences.

[0111] According to a second embodiment of this application, the projection system 1000_2 may include a projection adjuster 400_1 installed between the imaging lens group 100 and the image source plane SS. Further, the projection adjuster 400_1 may be installed between the imaging lens group 100 and the prism 200. In this case, the projection adjuster 400_1 can be considered to be installed at the rear end of the optical path of the imaging lens group 100.

[0112] The projection adjuster 400_1 can adjust the aspect ratio of the projected image projected onto the imaging surface SI according to its own lens configuration, so as to match the size of the imaging surface SI (e.g., the diffuser surface).

[0113] The following will be referenced Figure 7 The specific structure and configuration of the projection adjuster 400_1 according to the second embodiment will be described in detail. Figure 7 A schematic structural diagram of a projection adjuster 400_1 according to a second embodiment of this application is shown.

[0114] According to a second embodiment of this application, the projection adjuster 400_1 may include a first lens E1 and a second lens E2 sequentially from the imaging surface SI to the image source surface SS. Specifically, the first lens E1 is a convex-concave lens with positive optical power, wherein its first side surface S1 is convex and its second side surface S2 is concave. The second lens E2 is a biconvex lens with positive optical power, wherein its first side surface S2 is convex and its second side surface S3 is convex.

[0115] Optionally, the first lens E1 and the second lens E2 are cemented together to form a cemented lens.

[0116] According to the second embodiment of this application, each of the first lens E1 and the second lens E2 may be a cylindrical lens, and its effective focal length and radius of curvature in the x-axis and y-axis directions may be different, so that the projection system including the projection adjuster 400_1 can have different magnifications in the x-axis and y-axis directions, thereby changing the aspect ratio of the image projected on the imaging surface.

[0117] Table 2 shows the radius of curvature R of each lens in the x-axis direction of the projection adjuster 400_1 in the second embodiment. x Thickness / distance d, refractive index Nd, and Abbe number Vd.

[0118]

[0119]

[0120] As shown in Table 1, in the second embodiment, the first side surface and the second side surface of any one of the first lens E1 and the second lens E2 are cylindrical surfaces, and the surface shape of the cylindrical surface can be defined by the formula (1) given in the first embodiment above.

[0121] As mentioned above, in this application, to ensure image quality, the cylindrical lens is configured with a valid radius of curvature only in one of the meridional and sagittal directions, while the radius of curvature in the other direction is set to infinity. For example, in this second embodiment, only the radius of curvature in the x-axis direction is configured with a valid value, while the radius of curvature in the y-axis direction is set to infinity. It should be understood that a radius of curvature of infinity in one direction means that the curvature in that direction is 0. Thus, the cylindrical lens can have different radii of curvature in the x-axis and y-axis directions.

[0122] In the second embodiment, the first lens E1 of the projection adjuster 400_1 may include a material with a low refractive index and a high Abbe number. Specifically, the refractive index Nd1 of the first lens E1 may satisfy 1.4 ≤ Nd1 ≤ 1.7, for example, Nd1 = 1.52. Specifically, the Abbe number Vd1 of the first lens E1 may satisfy 40 ≤ Vd1 ≤ 70, for example, Vd1 = 64.2.

[0123] In the second embodiment, the second lens E2 of the projection adjuster 400_1 may include a material with a high refractive index and a low Abbe number. Specifically, the refractive index Nd2 of the second lens E2 can satisfy 1.6 ≤ Nd2 ≤ 1.9, for example, Nd2 = 1.67. Specifically, the Abbe number Vd2 of the second lens E2 can satisfy 25 ≤ Vd2 ≤ 40, for example, Vd2 = 32.2.

[0124] The projection system 1000_2 according to the second embodiment satisfies: 10mm ≤ f Ax ≤100mm, where f Ax It is the overall effective focal length of the projection adjuster 400_1 in the x-axis direction.

[0125] The projection system 1000_2 according to the second embodiment satisfies: 0.5 ≤ |f Ax / f S |≤5, where f Ax It is the overall effective focal length of the projection adjuster 400_1 in the x-axis direction, f S It is the overall effective focal length of the imaging lens group 100.

[0126] Compared to the first embodiment, the projection adjuster 400_1 disposed in the rear optical path of the imaging lens group 100 can have a smaller aperture.

[0127] Compared to the comparative embodiments, the image projected onto the imaging plane SI by the projection system 1000_2 according to the second embodiment of this application can be stretched in the x-axis direction while remaining unchanged in the y-axis direction.

[0128] According to a second embodiment of this application, the image projected onto the imaging surface SI can have a length in the y-axis direction and a width in the x-axis direction. For example, the length can be about 107 mm, the width can be about 73 mm, and the aspect ratio of the image can be about 1.48:1.

[0129] According to the second embodiment of this application, the light emission angle βy in the y-axis direction can be about 16.6°, and the light emission angle βx in the x-axis direction can be about 11.2°.

[0130] For example, the image stretching caused by the projection adjuster 400_1 in the second embodiment can be corrected and restored by a post-processing algorithm, thereby ensuring that the image ratio can be changed without pixel loss.

[0131] In this second embodiment, for ease of description, only an example is shown where the radius of curvature in the x-axis direction is set to a valid value so that the projected image can be stretched in the x-axis direction relative to the comparative embodiment. However, it should be understood that in other embodiments, the radius of curvature in the x-axis direction can also be adjusted to compress the projected image in the x-axis direction relative to the comparative embodiment. Similarly, in other embodiments, the radius of curvature in the y-axis direction can be set to a valid value only so that the projected image can be stretched or compressed in the y-axis direction relative to the comparative embodiment, or the radii of curvature in the x-axis and y-axis directions can be set to different valid values ​​so that the projected image can be stretched or compressed in both the x-axis and y-axis directions relative to the comparative embodiment.

[0132] Example 3

[0133] The following is for reference Figures 8 to 9 A projection system according to a third embodiment of this application is described. Figure 8 A schematic diagram of the projection system 1000_3 according to a third embodiment of this application is shown.

[0134] like Figure 8 As shown, the projection system 1000_3 according to an exemplary embodiment of this application may include a plurality of projection adjusters 400_2 that set the front end and rear end of the optical path of the imaging lens group 100. For example, the projection adjuster 400_2 may include a first projection adjuster 410_2 set at the front end of the optical path of the imaging lens group 100 and a second projection adjuster 420_2 set at the rear end of the optical path of the imaging lens group 100.

[0135] The projection adjuster 400_2 can adjust the aspect ratio of the projected image projected onto the imaging surface SI differently by using the lens configuration of multiple sub-projection adjusters set at different positions, so as to match the size of the imaging surface SI (e.g., the diffuser surface).

[0136] Reference Figure 8 The projection system 1000_3 may sequentially include, from the image source plane SS to the imaging plane SI, a projection image generator (not shown), a second sub-projection adjuster 420_2, an imaging lens group 100, and a first sub-projection adjuster 410_2. Similar to Embodiment 1, the projection system 1000_3 may also include a prism 200 and a protective member or filter 300 disposed between the second sub-projection adjuster 420_2 and the image source plane SS.

[0137] According to the third embodiment of this application, the image generated from the projection image generator can be projected onto the imaging surface SI in sequence through the protective member or filter 300, prism 200, second sub-projection adjuster 420_2, imaging lens group 100 and first sub-projection adjuster 410_2.

[0138] The configuration of the projection image generator and imaging lens group 100 according to the third embodiment is the same as that according to the first embodiment, the second embodiment and the comparative embodiment. For the sake of simplicity, redundant descriptions will not be given here, and the focus will be on describing the differences.

[0139] The following will be referenced Figure 9 The specific structure and configuration of the projection adjuster 400_2 according to the third embodiment will be described in detail. Figure 9 A schematic structural diagram of a projection adjuster 400_2 according to a third embodiment of this application is shown.

[0140] According to the third embodiment, the first sub-projection adjuster 410_2 may include at least one lens with optical power, for example... Figure 9 The lens shown is the first lens E1. The first lens E1 is a convex-concave lens with negative optical power, its first side surface S1 is convex, and its second side surface S2 is concave.

[0141] According to the third embodiment, the second sub-projection adjuster 420_2 may include at least one lens with optical power, for example... Figure 9 The lens shown is the second lens E2. The second lens E2 is a biconvex lens with positive optical power, and its first side surface S3 is convex, and its second side surface S4 is convex.

[0142] According to the third embodiment of this application, each of the first lens E1 and the second lens E2 included in the projection adjuster 400_2 can be a freeform mirror, and its effective focal length and radius of curvature in the x-axis direction and y-axis direction can be different, so that the projection system including the projection adjuster 400_2 can have different magnifications in the x-axis direction and y-axis direction, thereby changing the aspect ratio of the image projected on the imaging surface.

[0143] Table 3 shows the radius of curvature R, thickness / distance d, refractive index Nd, and Abbe number Vd of each lens of the projection adjuster 400_2 in the third embodiment.

[0144]

[0145]

[0146] Table 3

[0147] As shown in Table 1, in the third embodiment, the first side surface S1 of the first lens E1 is an even-order aspherical surface, and its second side surface S2 is a freeform surface, such as a non-rotationally symmetric aspherical surface. The first side surface S3 of the second lens E2 is a freeform surface, such as a non-rotationally symmetric aspherical surface, and its second side surface S4 is an even-order aspherical surface. The use of even-order aspherical surfaces can effectively correct distortion and improve image resolution, etc.

[0148] In this embodiment, the surface shape x of each aspherical lens can be defined using, but is not limited to, the following aspherical formula:

[0149]

[0150] Where x is the distance vector from the vertex of the aspherical surface along the optical axis at a height of h; c is the paraxial curvature of the aspherical surface, c = 1 / R (i.e., the paraxial curvature c is the reciprocal of the radius of curvature R); k is the conic coefficient; Ai is the i-th order correction coefficient of the aspherical surface.

[0151] Furthermore, the surface shape of a non-rotationally symmetric freeform surface can be defined using, but is not limited to, the following formulas:

[0152]

[0153] Where z is the sag of the surface parallel to the z-axis; c x c y Let be the curvature of the paraxial region along the x-axis and y-axis, respectively (=1 / radius of curvature); k x k y, respectively, are the conic coefficients in the x-axis and y-axis directions; x represents the maximum aperture in the x-axis direction; y represents the maximum aperture in the y-axis direction; Ai is the i-th order correction coefficient for the aspherical surface.

[0154] In the third embodiment, the first lens E1 and the second lens E2 of the projection adjusters 410_2 and 420_2 can have the same lens material, but this is only an example. In other embodiments, they can have different lens materials.

[0155] In the third embodiment, each of the first lens E1 and the second lens E2 of the projection adjusters 410_2 and 420_2 may comprise a material with a low refractive index and a high Abbe number. Specifically, the refractive indices Nd1 and Nd2 of the first lens E1 and the second lens E2 may satisfy 1.4 ≤ Nd1 ≤ 1.7 and 1.4 ≤ Nd2 ≤ 1.7. Specifically, the Abbe numbers Vd1 and Vd2 of the first lens E1 and the second lens E2 may satisfy 40 ≤ Vd1 ≤ 70 and 40 ≤ Vd2 ≤ 70.

[0156] The projection system 1000_3 according to the third embodiment satisfies: |f A1x |<|f A1y |, where f A1x It is the overall effective focal length of the first sub-projection adjuster 410_2 in the x-axis direction, f A1y It is the overall effective focal length of the first sub-projection adjuster 410_2 in the y-axis direction. It satisfies |f A1x |<|f A1y The projection system can be controlled to have a magnification ratio in the x-axis direction that is less than that in the y-axis direction. This allows the projected image to be further stretched in the y-axis direction and further compressed in the x-axis direction compared to the comparative embodiment, thereby further increasing the aspect ratio of the projected image.

[0157] The projection system 1000_3 according to the third embodiment satisfies: -50mm≤f A1x ≤-200mm, and -100mm≤f A1y ≤-400mm, where f A1x It is the overall effective focal length of the first sub-projection adjuster 410_2 in the x-axis direction, f A1y It is the overall effective focal length of the first sub-projection adjuster 410_2 in the y-axis direction.

[0158] The projection system 1000_3 according to the third embodiment satisfies: |f A2x |≤|f A2y |, where f A2xIt is the overall effective focal length of the second sub-projection adjuster 420_2 in the x-axis direction, f A2y It is the overall effective focal length of the second sub-projection adjuster 420_2 in the y-axis direction. Similar to the first sub-projection adjuster 410_2, it satisfies |f A2x |≤|f A2y This can help to further increase the aspect ratio of the projected image.

[0159] The projection system 1000_3 according to the third embodiment satisfies: 10mm ≤ f A2x ≤40mm, and 10mm≤f A2y ≤50mm, where f A2x It is the overall effective focal length of the second sub-projection adjuster 420_2 in the x-axis direction, f A2y It is the overall effective focal length of the second sub-projection adjuster 420_2 in the y-axis direction.

[0160] According to the projection system 1000_3 of the third embodiment, the following condition can be satisfied: -15≤f A1x / D S1 ≤-5 and -15≤f A1y / D S1 ≤-5, where D S1 It is the maximum aperture of the lens in the imaging lens group 100 that is closest to the first sub-projection adjuster 410_2, f A1x It is the overall effective focal length of the first sub-projection adjuster 410_2 in the x-axis direction, f A1y It is the overall effective focal length of the first sub-projection adjuster 410_2 in the y-axis direction.

[0161] The projection system 1000_3 according to the third embodiment satisfies: 1.5 ≤ f A2x / D S2 ≤3.5 and 1.5≤f A2y / D S2 ≤3.5, where D S2 It is the maximum aperture of the lens in the imaging lens group 100 that is closest to the second sub-projection adjuster 420_2, f A2x It is the overall effective focal length of the second sub-projection adjuster 420_2 in the x-axis direction, f A2y It is the overall effective focal length of the second sub-projection adjuster 420_2 in the y-axis direction.

[0162] Compared to the comparative embodiments, the image projected onto the imaging plane SI by the projection system 1000_1 according to the third embodiment of this application can be stretched in the y-axis direction and compressed in the x-axis direction. Therefore, compared to the first and second embodiments, the aspect ratio of the projected image can be further increased.

[0163] According to a third embodiment of this application, the image projected onto the imaging plane SI can have a length in the y-axis direction and a width in the x-axis direction. For example, the aspect ratio of the image can be approximately 3.95:1.

[0164] According to the third embodiment of this application, the light emission angle βy in the y-axis direction can be about 30°, and the light emission angle βx in the x-axis direction can be about 7.6°.

[0165] For example, the image distortion caused by the projection adjuster 400_2 in the third embodiment can be corrected and restored by a post-processing algorithm, thereby ensuring that the image ratio can be changed without pixel loss.

[0166] In this third embodiment, for the sake of clarity, only an example is shown of further increasing the aspect ratio of the projected image by compressing its width in the x-axis direction and stretching its length in the y-axis direction relative to the comparative embodiment. However, it should be understood that in other embodiments, parameters such as the radius of curvature and focal length in the x-axis and y-axis directions can be adjusted so that the projected image is compressed in the y-axis direction and stretched in the x-axis direction relative to the comparative embodiment, thereby further reducing the aspect ratio of the projected image.

[0167] It should be understood that, for ease of description, this application uses an imaging lens group comprising six lenses according to a comparative embodiment as a comparison to visually illustrate the effect of the projection adjuster on the aspect ratio of the projected image of the projection system.

[0168] However, this is for illustrative purposes only and does not imply that the projection adjusters according to the various embodiments of this application can only use the described imaging lens groups. On the contrary, the projection adjusters according to the various embodiments of this application can be used with various types of imaging lens groups to adjust the aspect ratio of the projected image. Of course, the number of lenses in the imaging lens group is not limited to the six listed in this application.

[0169] This application also provides a head-up display system, which includes the projection system described in the above embodiments of this application.

[0170] This application also provides an intelligent headlight projection system, which includes the projection system described in the above embodiments of this application.

[0171] This application also provides a method for manufacturing a projection system, comprising: preparing a projection image generator configured to generate a projected image; preparing an imaging lens group including at least one lens having optical power; preparing a projection adjuster including at least one lens having optical power; and assembling the projection image generator, the imaging lens group, and the projection adjuster together.

[0172] The projection adjuster is assembled between the imaging lens group and the projection image generator and / or between the imaging lens group and the imaging surface of the projection system, and the preparation of the projection adjuster includes forming the overall effective focal length of the projection adjuster in the x-axis direction and the overall effective focal length in the y-axis direction, which is different from the x-axis direction, to be different from each other.

[0173] The above description is merely a preferred embodiment of this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention involved in this application is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions disclosed in this application.

Claims

1. Projection system, characterized in that The projection system comprises: a projection image generator configured to generate a projection image; an imaging lens group comprising at least one lens having optical power; and a projection adjuster comprising at least one lens having optical power, wherein the projection image is projected on an imaging plane of the projection system via the imaging lens group and the projection adjuster, and wherein the projection adjuster comprises, in order from a first side to a second side, a first lens having positive optical power, a second lens having negative optical power, a third lens having negative optical power, and a fourth lens having positive optical power, the first side being an imaging side and the second side being an image source side. Wherein the projection system satisfies: f Ax ≠ f Ay Wherein f Ax is the overall effective focal length of the projection adjuster in the x-axis direction, f Ay is the overall effective focal length of the projection adjuster in the y-axis direction different from the x-axis direction, wherein the projection adjuster is disposed between the imaging lens group and an imaging plane of the projection system, the projection system satisfying: -15 Ax / D S ≤ -5 and -15 ≤ f Ay / D S ≤ -5, wherein D S is a maximum clear aperture of a lens of the imaging lens group closest to the projection adjuster, At least one of the lenses comprised in the projection adjuster is a cylindrical lens or a freeform lens.

2. The projection system of claim 1, wherein, 7. The projection system of claim 1, wherein:

3. The projection system of claim 1, wherein, The projection system satisfies: 0 < f Ax / f Ay < 1, wherein f Ax is the overall effective focal length of the projection adjuster in an x-axis direction, and f Ay is the overall effective focal length of the projection adjuster in a y-axis direction different from the x-axis direction.

4. The projection system of claim 1, wherein, The overall effective focal length f of the projection modulator in the x-axis direction Ax satisfies -500mm ≤ f Ax ≤ -50mm, and The overall effective focal length f of the projection modulator in the y-axis direction Ay satisfies -500mm ≤ f Ay ≤ -50mm.

5. The projection system of claim 1, wherein, The projection system satisfies: 4≤|f Ax / f S |≤10 and 4≤|f Ay / f S |≤10, where f S is the overall effective focal length of the imaging lens group.

6. The projection system of claim 1, wherein, The projection system satisfies: 1.6≤D A / L AS ≤4.7, wherein D A is the maximum total aperture of the projection adjuster, and L AS is the on-axis distance between the projection adjuster and the imaging lens group. a first side surface of the first lens is convex, and a second side surface of the first lens is convex; a first side surface of the second lens is concave, and a second side surface of the second lens is concave; a first side surface of the third lens is concave, and a second side surface of the third lens is concave; and a first side surface of the fourth lens is convex, and a second side surface of the fourth lens is convex. The projection system of any one of claims 1-7.

8. A heads-up display system characterized by, The projection system of any one of claims 1-7.

9. An intelligent headlamp projection system, characterized by, The projection system comprises:

10. A method of manufacturing a projection system, characterized by, preparing a projection image generator configured to generate a projection image; preparing an imaging lens group comprising at least one lens having optical power; preparing a projection adjuster comprising at least one lens having optical power; and assembling the projection image generator, the imaging lens group, and the projection adjuster together, wherein the projection adjuster is assembled between the imaging lens group and an imaging plane of the projection system, and wherein preparing the projection adjuster comprises forming an overall effective focal length of the projection adjuster in an x-axis direction and an overall effective focal length of the projection adjuster in a y-axis direction different from the x-axis direction to be different from each other, wherein the projection adjuster comprises, in order from a first side to a second side, a first lens having positive optical power, a second lens having negative optical power, a third lens having negative optical power, and a fourth lens having positive optical power, the first side being an imaging side and the second side being an image source side.

11. The method of claim 10, wherein: wherein the projection system satisfies: -15 < f Ax / D S ≤ -5 and -15 < f Ay / D S ≤ -5, wherein D S is the maximum clear aperture of the lens of the imaging lens group closest to the projection adjuster. a first side surface of the first lens is convex, and a second side surface of the first lens is convex; a first side surface of the second lens is concave, and a second side surface of the second lens is concave; a first side surface of the third lens is concave, and a second side surface of the third lens is concave; and a first side surface of the fourth lens is convex, and a second side surface of the fourth lens is convex. ​ ​

Images