Manufacturing method of prism, prism and optical lens

Abstract

The invention discloses a prism manufacturing method, a prism and an optical lens. The manufacturing method of the prism comprises the steps that an initial prism is constructed, the initial prism comprises a first initial surface, a second initial surface and a third initial surface, the second initial surface and the third initial surface are connected with the first initial surface, and the side, away from the first initial surface, of the second initial surface is connected with the side, away from the first initial surface, of the third initial surface; the end part, far away from the first initial surface, of the reflecting region of the second initial surface and the end part, far away from the first initial surface, of the reflecting region of the third initial surface are symmetrical relative to the central axis of the initial prism; trimming the second initial surface and the third initial surface according to the end parts, far away from the first initial surface, of the two reflection regions so as to form a fourth initial surface parallel to the first initial surface; and a concave structure is arranged on the fourth initial surface according to the stray light state of a light spot formed after the light is emitted from the trimmed initial prism.

Description

Technical Field

[0001] This application relates to the field of optical devices, specifically to a method for manufacturing a prism, the prism itself, and an optical lens. Background Technology

[0002] With the rapid development of portable devices such as smartphones, telephoto lenses have been widely used due to their advantages such as clear imaging of distant objects, large magnification, and ability to present detailed features of objects.

[0003] Telephoto lenses typically employ prisms as optical path deflection elements to achieve their telephoto capabilities while reducing overall length, thus enabling miniaturization. Current prisms are usually triangular prisms. If the prism's reflection height is too high, its size becomes excessive, hindering miniaturization; conversely, if the reflection height is too low, it negatively impacts image quality. Furthermore, as the number of reflections within the prism increases, the risk of stray light also increases, significantly affecting the telephoto lens's image quality. Summary of the Invention

[0004] The first aspect of this application provides a method for manufacturing a prism, comprising: constructing an initial prism, wherein the initial prism includes a first initial surface and a second initial surface and a third initial surface connected to the first initial surface, the side of the second initial surface away from the first initial surface being connected to the side of the third initial surface away from the first initial surface; in response to determining that the ends of the reflection areas of the second initial surface away from the first initial surface and the ends of the reflection areas of the third initial surface away from the first initial surface are symmetrical with respect to the central axis of the initial prism, cutting the second initial surface and the third initial surface according to the ends of the two reflection areas away from the first initial surface to form a fourth initial surface parallel to the first initial surface; and providing a recessed structure on the fourth initial surface according to the stray light state of the light spot formed after the light is emitted from the initial prism after cutting the edges.

[0005] According to an exemplary embodiment of this application, constructing an initial prism includes: determining the structural parameters of the initial prism based on the thickness of the equivalent plate corresponding to the initial prism, the angle between the first initial surface and the second initial surface, the angle between the first initial surface and the third initial surface, and the incident position of the light on the first initial surface, wherein the incident position is a quarter position of the first initial surface, and the structural parameters include the distance from the intersection of the first optical axis and the first initial surface to the first end of the first initial surface, the distance from the intersection of the second optical axis and the first initial surface to the second end of the first initial surface, and the distance between the first optical axis and the second optical axis, wherein the first optical axis is the principal optical axis of the light incident on the initial prism, and the second optical axis is the principal optical axis of the light emitted from the initial prism; and forming the initial prism based on the angle between the first initial surface and the second initial surface, the angle between the first initial surface and the third initial surface, and the structural parameters of the initial prism.

[0006] According to an exemplary embodiment of this application, trimming the second and third initial surfaces based on the ends of the two reflective regions away from the first initial surface includes trimming the second and third initial surfaces based on a line drawn between the ends of the two reflective regions away from the first initial surface, wherein a fourth initial surface is parallel to the line drawn between them.

[0007] According to an exemplary embodiment of this application, the manufacturing method further includes: in response to determining that the end of the reflection region of the second initial surface away from the first initial surface and the end of the reflection region of the third initial surface away from the first initial surface are symmetrical with respect to the central axis of the initial prism, removing at least a portion of the portion where the first initial surface is connected to the second initial surface, and removing at least a portion of the portion where the first initial surface is connected to the third initial surface.

[0008] According to an exemplary embodiment of this application, setting a recessed structure on a fourth initial surface based on the stray light state of the light spot formed after the light is emitted from the initial prism after the prism is cut includes: determining the position, size, and shape of the recessed structure based on the stray light state of the light spot; and setting the recessed structure on the fourth initial surface based on the position, size, and shape of the recessed structure.

[0009] According to an exemplary embodiment of this application, setting a recessed structure on a fourth initial surface according to the position, size, and shape of the recessed structure includes: in response to determining that d0 / h0≤γ, γ≤0.55, setting a recessed structure on the fourth initial surface according to the position, size, and shape of the recessed structure, wherein d0 is the size of the recessed structure in a direction perpendicular to the fourth initial surface, and h0 is the distance from the fourth initial surface to the first initial surface.

[0010] According to an exemplary embodiment of this application, setting a recessed structure on a fourth initial surface according to the location, size, and shape of the recessed structure includes: adjusting the angle between the first initial surface and the second initial surface and the angle between the first initial surface and the third initial surface in response to determining that d0 / h0 > γ, γ ≤ 0.55.

[0011] According to an exemplary embodiment of this application, setting a recessed structure on a fourth initial surface according to the location, size, and shape of the recessed structure includes: in response to determining |ΔRI H1 -ΔRI H2 |<δ,δ≤3,The recessed structure is set on the fourth initial surface according to the position, size and shape of the recessed structure, where ΔRI H1 ΔRI is the difference between the relative illumination of the light spot corresponding to the initial prism with the concave structure at a position with an image height of H1 and the relative illumination of the light spot corresponding to the initial prism after shaving at a position with an image height of H1. H2 H1 = -H2 is the difference between the relative illumination of the light spot corresponding to the initial prism with the concave structure at the position of image height H2 and the relative illumination of the light spot corresponding to the initial prism after the edge is cut at the position of image height H2.

[0012] According to an exemplary embodiment of this application, setting a recessed structure on a fourth initial surface according to the location, size, and shape of the recessed structure includes: in response to determining |ΔRI H1 -ΔRI H2 |≥δ,δ≤3,Adjust the position and / or shape of the concave structure, where ΔRI H1 ΔRI is the difference between the relative illumination of the light spot corresponding to the initial prism with the concave structure at a position with an image height of H1 and the relative illumination of the light spot corresponding to the initial prism after shaving at a position with an image height of H1. H2 H1 = -H2 is the difference between the relative illumination of the light spot corresponding to the initial prism with the concave structure at the position of image height H2 and the relative illumination of the light spot corresponding to the initial prism after the edge is cut at the position of image height H2.

[0013] According to an exemplary embodiment of this application, the recessed structure has a dimension greater than 0.8 mm and less than 1.2 mm in the direction parallel to the fourth initial surface.

[0014] According to an exemplary embodiment of this application, the end of the recessed structure near the first initial surface is arc-shaped, with a radius greater than 0.2 mm and less than 0.5 mm.

[0015] According to an exemplary embodiment of the present application, the end of the concave structure near the first initial surface includes a first part and a second part. The first part is arc-shaped, and the included angle between the second part and the central axis of the initial prism is greater than 30° and less than 40°.

[0016] A second aspect of the present application provides such a prism, which is manufactured by the manufacturing method described in the first aspect of the present application.

[0017] A third aspect of the present application provides such an optical lens, which includes an imaging lens group, a prism as described in the second aspect of the present application, and an imaging surface. The imaging lens group and the imaging surface are located on the same side of the prism. The imaging lens group sequentially includes a first lens, a second lens, a third lens, and a fourth lens along the first optical axis from the object side to the image side. The first lens has a positive optical power, its object side surface is convex, and its image side surface is convex. The second lens has a positive optical power, its object side surface is convex, and its image side surface is concave. The third lens has a negative optical power, its object side surface is convex, and its image side surface is concave. The fourth lens has a negative optical power, its object side surface is convex, and its image side surface is concave. The number of lenses with optical power in the optical lens is four. The prism has a first surface and a second surface that are parallel to each other, and a concave structure is provided on the first surface of the prism. The size d of the concave structure in the direction perpendicular to the first surface and the distance h between the first surface and the second surface of the prism satisfy: 0.3 < d / h ≤ 0.55.

[0018] According to an exemplary embodiment of the present application, the total effective focal length f of the optical lens, the effective focal length f1 of the first lens, and the refractive index N1 of the first lens satisfy: 0.85 < f1×N1 / f < 0.95.

[0019] According to an exemplary embodiment of the present application, the effective focal length f2 of the second lens, the central thickness CT2 of the second lens on the first optical axis, and the spacing distance T23 between the second lens and the third lens on the first optical axis satisfy: 70.75 < f2 / CT2 + f2 / T23 < 110.35; and the effective focal length f2 of the second lens and the spacing distance T23 between the second lens and the third lens on the first optical axis satisfy: 53.2 < f2 / T23 ≤ 93.2.

[0020] According to an exemplary embodiment of the present application, the total effective focal length f of the optical lens and the radius of curvature R3 of the object side surface of the second lens satisfy: 3.8 < f / R3 ≤ 4.2; and the total effective focal length f of the optical lens, the radius of curvature R3 of the object side surface of the second lens, and the radius of curvature R4 of the image side surface of the second lens satisfy: 5.4 < f / R4 + f / R3 < 5.95.

[0021] According to an exemplary embodiment of this application, the combined focal length f12 of the first lens and the second lens, the center thickness CT1 of the first lens on the first optical axis, and the center thickness CT2 of the second lens on the first optical axis satisfy: 2.7 <f12 / (CT1+CT2)<2.95。

[0022] According to an exemplary embodiment of this application, the effective focal length f3 of the third lens, the refractive index N3 of the third lens, and the radius of curvature R5 of the object-side surface of the third lens satisfy: -3.4 <f3×N3 / R5<-2.25。

[0023] According to an exemplary embodiment of this application, the center thickness CT3 of the third lens on the first optical axis and the spacing T34 between the third lens and the fourth lens on the first optical axis satisfy: 1.9≤T34 / CT3<2.2.

[0024] According to an exemplary embodiment of this application, the effective focal length f4 of the fourth lens and the radius of curvature R7 of the object-side surface of the fourth lens satisfy: -3.15 <R7 / f4<-1.5。

[0025] According to an exemplary embodiment of this application, the radius of curvature R8 of the image-side surface of the fourth lens and the center thickness CT4 of the fourth lens on the first optical axis satisfy: 11.45 <R8 / CT4<12.2。

[0026] According to an exemplary embodiment of this application, the center thickness CT2 of the second lens on the first optical axis and the spacing T23 between the second and third lenses on the first optical axis satisfy: 3.0 <CT2 / T23<5.45。

[0027] According to an exemplary embodiment of this application, the effective focal length f1 of the first lens, the Abbe number V1 of the first lens, and the radius of curvature R1 of the object surface of the first lens satisfy: 142.9 <f1×V1 / R1<161.55。

[0028] According to an exemplary embodiment of this application, the combined focal length f23 of the second lens and the third lens and the spacing T23 of the second lens and the third lens on the first optical axis satisfy: 130.85 <f23 / T23<236.65。

[0029] According to an exemplary embodiment of this application, the total effective focal length f of the optical lens and the effective focal length f2 of the second lens satisfy: 1.25 <f / f2<1.45。

[0030] According to an exemplary embodiment of this application, the effective focal length f1 of the first lens and the effective focal length f2 of the second lens satisfy: 0.7 <f1 / f2<0.85。

[0031] According to an exemplary embodiment of this application, the on-axis distance from the image side of the fourth lens to the first surface of the prism is greater than the on-axis distance from the image side of the fourth lens to the second surface of the prism.

[0032] According to an exemplary embodiment of this application, the dimension of the first surface in the direction perpendicular to the first optical axis is smaller than the dimension of the second surface in the direction perpendicular to the first optical axis.

[0033] According to an exemplary embodiment of this application, the prism further includes a third surface and a fourth surface, wherein the angle between the plane containing the second surface and the plane containing the third surface is the same as the angle between the plane containing the second surface and the plane containing the fourth surface.

[0034] In some embodiments of this application, when it is determined that the ends of the reflection areas of the second initial surface away from the first initial surface and the ends of the reflection areas of the third initial surface away from the first initial surface are symmetrical with respect to the central axis of the initial prism, the second and third initial surfaces are trimmed according to the ends of the two reflection areas away from the first initial surface. This ensures that the trimmed initial prism has a minimum thickness, which is beneficial for miniaturizing the prism and the optical lens including the prism. Then, based on the stray light state of the light spot formed after the light rays exit from the trimmed initial prism, a recessed structure is provided on the fourth initial surface of the trimmed initial prism. This allows most of the stray light to be blocked by the recessed structure, reducing the stray light risk of the prism and the optical lens including the prism, and improving the imaging quality of the prism and the optical lens including the prism. Attached Figure Description

[0035] Other features, objects, and advantages of this application will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings. Wherein:

[0036] Figure 1 A schematic flowchart of a method for manufacturing a prism according to an exemplary embodiment of this application is shown;

[0037] Figure 2 A schematic diagram of the structure of an initial prism according to an exemplary embodiment of this application is shown;

[0038] Figure 3 A schematic diagram of the structure of an initial prism according to an exemplary embodiment of this application is shown;

[0039] Figure 4 A schematic diagram of the structure of the initial prism after trimming is shown according to an exemplary embodiment of this application;

[0040] Figure 5 A schematic diagram of an initial prism with a recessed structure according to an exemplary embodiment of this application is shown;

[0041] Figure 6 A schematic diagram of an initial prism with a recessed structure according to an exemplary embodiment of this application is shown;

[0042] Figure 7 A schematic flowchart of a method for manufacturing a prism according to an exemplary embodiment of this application is shown;

[0043] Figure 8 A schematic diagram of the structure of a prism according to an exemplary embodiment of this application is shown;

[0044] Figure 9 A schematic diagram of the structure of a prism according to an exemplary embodiment of this application is shown;

[0045] Figure 10 A schematic diagram of the structure of an optical lens according to Embodiment 1 of this application is shown;

[0046] Figure 11A , Figure 11B , Figure 11C The on-axis chromatic aberration curve, astigmatism curve, and magnification chromatic aberration curve of the optical lens according to Embodiment 1 of this application are shown respectively.

[0047] Figure 12A A stray light simulation diagram is shown for the optical lens according to Embodiment 1 of this application when d / h = 0;

[0048] Figure 12B A stray light simulation diagram is shown for the optical lens according to Embodiment 1 of this application when d / h = 0.22;

[0049] Figure 12C A stray light simulation diagram of the optical lens according to Embodiment 1 of this application is shown when the optical lens satisfies d / h = 0.50;

[0050] Figure 12D A stray light simulation diagram of the optical lens according to Embodiment 1 of this application is shown when the optical lens satisfies d / h = 0.60;

[0051] Figure 13 The relative illumination of the optical lens according to Embodiment 1 of this application at different d / h is shown;

[0052] Figure 14 A schematic diagram of the structure of an optical lens according to Embodiment 2 of this application is shown;

[0053] Figure 15A , Figure 15B , Figure 15C The on-axis chromatic aberration curve, astigmatism curve, and magnification chromatic aberration curve of the optical lens according to Embodiment 2 of this application are shown respectively.

[0054] Figure 16A A stray light simulation diagram is shown for an optical lens according to Embodiment 2 of this application that satisfies d / h = 0;

[0055] Figure 16B A stray light simulation diagram is shown for the optical lens according to Embodiment 2 of this application when d / h = 0.52;

[0056] Figure 17 A schematic diagram of the structure of an optical lens according to Embodiment 3 of this application is shown;

[0057] Figure 18A , Figure 18B , Figure 18C The on-axis chromatic aberration curve, astigmatism curve, and magnification chromatic aberration curve of the optical lens according to Embodiment 3 of this application are shown respectively.

[0058] Figure 19A A stray light simulation diagram is shown for an optical lens according to Embodiment 3 of this application that satisfies α = 34.0° and d / h = 0;

[0059] Figure 19B An optical lens according to Embodiment 3 of this application is shown to satisfy... α Simulated stray light pattern at 34.0° and d / h = 0.51;

[0060] Figure 20A A stray light simulation diagram is shown for an optical lens according to Embodiment 3 of this application that satisfies α = 32.0° and d / h = 0;

[0061] Figure 20B A stray light simulation diagram is shown for the optical lens according to Embodiment 3 of this application when α = 32.0° and d / h = 0.33;

[0062] Figure 21A A stray light simulation diagram is shown for an optical lens according to Embodiment 3 of this application satisfying α = 36.0° and d / h = 0; and

[0063] Figure 21B A stray light simulation diagram is shown for the optical lens according to Embodiment 3 of this application when α = 36.0° and d / h = 0.55. Detailed Implementation

[0064] 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.

[0065] 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.

[0066] 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 drawn strictly to scale.

[0067] In this article, 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 subject is called the object-side surface of the lens, and the surface of each lens closest to the image plane is called the image-side surface of the lens.

[0068] It should also be understood that the terms "comprising" and / or "having," when 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.

[0069] 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 formalized sense, unless expressly so specified herein.

[0070] 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.

[0071] To achieve the telephoto capability of an optical lens, a prism can be incorporated into the lens. The prism increases the total effective focal length of the optical lens by folding the light path, thereby reducing the overall length of the optical lens while still satisfying its telephoto characteristics, thus achieving miniaturization of the optical lens.

[0072] However, current optical lenses still have some shortcomings. For example, current prisms are typically triangular prisms, consisting of a base and a first and a second reflecting surface connected to the base. The side of the first reflecting surface furthest from the base is connected to the side of the second reflecting surface furthest from the base. The reflection height of the prism can be related to the angle between the base and the first reflecting surface, the angle between the base and the second reflecting surface, and the size of the base. When the reflection height of the prism is too high, the prism becomes too large, hindering the miniaturization of telephoto lenses. When the reflection height of the prism is too low, it affects the image quality of the telephoto lens. Furthermore, as the number of reflections inside the prism increases, the risk of stray light in the optical lens also increases, which significantly affects the image quality. Moreover, treatments such as applying ink or fogging to the prism surface are insufficient to effectively remove the impact of stray light on the optical lens.

[0073] In order to at least partially solve one or more of the above-mentioned problems and other potential problems, the first aspect of this application provides a method 1000 for manufacturing a prism.

[0074] Figure 1 A schematic flowchart of a prism manufacturing method 1000 according to an exemplary embodiment of this application is shown. The prism manufactured using this prism manufacturing method 1000 can be applied, for example, to an optical lens, which can be, for example, a telephoto lens.

[0075] refer to Figure 1 The method 1000 for manufacturing the prism may include the following steps:

[0076] S10. Construct an initial prism, wherein the initial prism includes a first initial surface and a second initial surface and a third initial surface connected to the first initial surface, and the side of the second initial surface away from the first initial surface is connected to the side of the third initial surface away from the first initial surface.

[0077] S20. In response to determining that the ends of the reflection areas of the second initial surface away from the first initial surface and the ends of the reflection areas of the third initial surface away from the first initial surface are symmetrical with respect to the central axis of the initial prism, the second initial surface and the third initial surface are trimmed according to the ends of the two reflection areas away from the first initial surface to form a fourth initial surface parallel to the first initial surface.

[0078] S30. Based on the stray light state of the light spot formed after the light rays exit from the initial prism after the tangent edge, a recessed structure is set on the fourth initial surface.

[0079] When it is determined that the ends of the reflection areas of the second initial surface away from the first initial surface and the ends of the reflection areas of the third initial surface away from the first initial surface are symmetrical with respect to the central axis of the initial prism, the second and third initial surfaces are truncated according to the ends of the two reflection areas away from the first initial surface. This ensures that the truncated initial prism has a minimum thickness, which is beneficial for miniaturizing the prism and the optical lens including the prism. Then, based on the stray light state of the light spot formed after the light is emitted from the truncated initial prism, a recessed structure is set on the fourth initial surface of the truncated initial prism. This allows most of the stray light to be blocked by the recessed structure, reducing the stray light risk of the prism and the optical lens including the prism, and improving the imaging quality of the prism and the optical lens including the prism.

[0080] Steps S10, S20, and S30 of the exemplary embodiments of this application are described below.

[0081] In step S10, an initial prism 100a is constructed. The initial prism 100a may include a first initial surface 101 and a second initial surface 102 and a third initial surface 103 connected to the first initial surface 101. The side of the second initial surface 102 away from the first initial surface 101 is connected to the side of the third initial surface 103 away from the first initial surface 101. The initial prism 100a may be a glass prism.

[0082] First, the structural parameters of the initial prism 100a are determined based on the thickness l of the equivalent plate corresponding to the initial prism 100a, the angle θ1 between the first initial surface 101 and the second initial surface 102, the angle θ2 between the first initial surface 101 and the third initial surface 103, and the incident position of the light on the first initial surface 101. The incident position can be a quarter position of the first initial surface 101. The structural parameters can include the distance c1 from the intersection of the first optical axis A and the first initial surface 101 to the first end of the first initial surface (e.g., the first end is the end of the first initial surface 101 near the second initial surface 102), the distance c2 from the intersection of the second optical axis B and the first initial surface 101 to the second end of the first initial surface (e.g., the second end is the end of the first initial surface 101 near the third initial surface 103), and the distance t between the first optical axis A and the second optical axis B. Finally, based on the included angle θ1 between the first initial surface 101 and the second initial surface 102, the included angle θ2 between the first initial surface 101 and the third initial surface 103, and the structural parameters of the initial prism, an initial prism 100a can be formed. The structure of the initial prism 100a can be referenced. Figure 2 The terms θ1, θ2, c1, c2, and t in this article can be found in [reference needed]. Figure 2The marking method shown is used. In this paper, the first optical axis A can be the principal optical axis of the light rays incident on the initial prism (e.g., 100a, 100b, 100c), and the second optical axis B can be the principal optical axis of the light rays exiting from the initial prism (e.g., 100a, 100b, 100c). The angle θ1 between the first initial surface 101 and the second initial surface 102 can be the same as the angle θ2 between the first initial surface 101 and the third initial surface 103, for example, both being α. α can be greater than or equal to 30° and less than or equal to 40°.

[0083] Specifically, the material of the equivalent plate is the same as that of the initial prism, and the optical path of the light in the equivalent plate is the same as that of the initial prism. Assuming the light enters the initial prism from a quarter-length position on the first initial surface 101, then c1 is 1 / 4 of the total length of the first initial surface 101, and the incident position of the light on the first initial surface 101 is also a quarter-length position. Given α, l, and the incident position of the light on the first initial surface 101, the values ​​of c1, c2, and t can be calculated using the following formulas (1), (2), (3), and (4). Here, M can be the distance from the side of the second initial surface 102 away from the first initial surface 101 to the first initial surface 101.

[0084]

[0085]

[0086] l = 4M * cos 2 Formula (3)

[0087]

[0088] After calculating the values ​​of c1, c2, and t, an initial prism 100a can be formed based on α, c1, c2, and t.

[0089] After forming the initial prism 100a, in step S20, in response to determining that the ends of the reflection areas of the second initial surface 102 and the third initial surface 103 away from the first initial surface 101 are symmetrical with respect to the central axis I of the initial prism, the second initial surface 102 and the third initial surface 103 are trimmed according to the ends of the two reflection areas away from the first initial surface 101, and the initial prism 100b can be formed after trimming. The structure of the initial prism 100b can be referred to Figure 4 The initial prism 100b may include a fourth initial surface 104, which may be parallel to the first initial surface 101.

[0090] refer to Figure 2 and Figure 3 Light rays can be incident along the first optical axis A via the first initial surface 101 onto the second initial surface 102, then reflected by the second initial surface 102 back to the first initial surface 101, and then reflected by the first initial surface 101 back to the third initial surface 103. Finally, the light rays are reflected by the third initial surface 103 back to the first initial surface 101 and exit along the second optical axis B via the first initial surface 101. Both the second initial surface 102 and the third initial surface 103 have a reflection area. For example, the area of ​​the second initial surface 102 used to receive light rays can be called the first reflection area 1021, and the area of ​​the third initial surface 103 used to receive light rays can be called the second reflection area 1031.

[0091] Adjust the incident position of the light at the initial prism 100a, and determine whether the end C of the first reflecting area 1021 away from the first initial surface 101 and the end D of the second reflecting area 1031 away from the first initial surface 101 are symmetrical with respect to the central axis I of the initial prism. If it is determined that the end C of the first reflecting area 1021 away from the first initial surface 101 and the end D of the second reflecting area 1031 away from the first initial surface 101 are symmetrical with respect to the central axis I of the initial prism (e.g., ... Figure 3 Then, the second initial surface 102 and the third initial surface 103 can be trimmed according to the end C of the first reflective area 1021 that is far away from the first initial surface 101 and the end D of the second reflective area 1031 that is far away from the first initial surface 101.

[0092] In an exemplary embodiment, the second initial surface 102 and the third initial surface 103 are trimmed by a line drawn between the end C of the first reflective region 1021 away from the first initial surface 101 and the end D of the second reflective region 1031 away from the first initial surface 101. For example, the portion of the second initial surface 102 and the third initial surface 103 located on the side away from the first initial surface 101 of the line is removed. The remaining portion of the initial prism 100a can then serve as the initial prism 100b (e.g., Figure 4 The fourth initial surface 104 of the initial prism 100b can be parallel to the first initial surface 101. The fourth initial surface 104 can be spaced a certain distance from the connecting line. Alternatively, the fourth initial surface 104 can be the plane containing the connecting line.

[0093] When the end C of the first reflective region 1021 away from the first initial surface 101 and the end D of the second reflective region 1031 away from the first initial surface 101 are symmetrical with respect to the central axis I of the initial prism, the second initial surface 102 and the third initial surface 103 are trimmed by the line connecting the end C of the first reflective region 1021 away from the first initial surface 101 and the end D of the second reflective region 1031 away from the first initial surface 101. This can remove as much of the ineffective area of ​​the initial prism 100a as possible, ensuring that the trimmed initial prism (e.g., 100b) has a minimum thickness. This is beneficial for miniaturizing the prism manufactured by this method, improving the manufacturing efficiency and yield of the prism, and avoiding the waste of manpower, resources, and time caused by insufficient trimming.

[0094] In an exemplary embodiment, if the end C of the first reflective region 1021 away from the first initial surface 101 and the end D of the second reflective region 1031 away from the first initial surface 101 are asymmetrical with respect to the central axis I of the initial prism, the incident position of the light on the initial prism 100a can be adjusted until the end C of the first reflective region 1021 away from the first initial surface 101 and the end D of the second reflective region 1031 away from the first initial surface 101 are symmetrical with respect to the central axis I of the initial prism. Alternatively, α can be adjusted, and c1, c2, and t can be redefined based on α, l, and the incident position of the light on the first initial surface 101, and the initial prism 100a can be constructed based on the redefined α, c1, c2, and t.

[0095] In an exemplary embodiment, by removing at least a portion of the first initial surface 101 that connects to the second initial surface 102, and at least a portion of the first initial surface 101 that connects to the third initial surface 103, the remaining portion of the initial prism 100a can serve as the initial prism 100b (e.g., Figure 4 Removing at least a portion of the first initial surface 101 that connects to the second initial surface 102 and the third initial surface 103 can further reduce the size of the initial prism (e.g., 100b) after edge trimming in the direction parallel to the first initial surface 101. This facilitates the miniaturization and module assembly of the prism manufactured using this method, and avoids stray light formed by multiple reflections of light at the sharp corners of the prism (e.g., the portion where the first initial surface 101 connects to the second initial surface 102 and the third initial surface 103).

[0096] After forming the initial prism 100b, in step S30, a recessed structure 105 is formed on the fourth initial surface 104 according to the stray light state of the light spot formed after the light rays exit from the initial prism (e.g., 100b) after the prism is truncated. The initial prism (e.g., 100c) after the recessed structure 105 is formed can be the final prism. The structure of the initial prism (e.g., 100c) after the recessed structure 105 is formed can be referred to Figure 5 and Figure 6 .

[0097] The light reflected from the second initial surface 102 to the first initial surface 101 interferes with the light reflected from the first initial surface 101 to the third initial surface 103. This causes significant stray light in the initial prism 100b, resulting in stray light in the light spot formed by the light emitted from the initial prism 100b, thus affecting the final image quality. To avoid this stray light problem, the position, size, and shape of the recessed structure 105 can be determined based on the stray light state of the light spot. Then, the recessed structure 105 is set on the fourth initial surface 104 according to the position, size, and shape of the recessed structure 105.

[0098] In an exemplary embodiment, after determining the position, size, and shape of the recessed structure 105, it is determined whether d0 / h0 is less than or equal to γ, where γ ≤ 0.55, where d0 is the size of the recessed structure 105 in the direction perpendicular to the fourth initial surface 104, and h0 is the distance from the fourth initial surface 104 to the first initial surface 101. If it is determined that d0 / h0 ≤ γ, the recessed structure 105 can be set on the fourth initial surface 104 according to its position, size, and shape. By making the recessed structure 105 have a reasonable depth, stray light can be blocked by the recessed structure 105 as much as possible. If d0 / h0 > γ, then adjust the angle between the first initial surface 101 and the second initial surface 102, as well as the angle between the first initial surface 101 and the third initial surface 103. For example, adjust α, redetermine c1, c2 and t based on α, l and the incident position of the light on the first initial surface 101, and construct the initial prism 100a based on the redetermined α, c1, c2 and t.

[0099] In an exemplary embodiment, after determining the position, size, and shape of the recessed structure 105, |ΔRI is determined. H1 -ΔRI H2 | Whether it is less than δ, δ≤3, where ΔRI H1 ΔRI is the difference between the relative illumination of the light spot corresponding to the initial prism with a concave structure (e.g., 100c) at a position with an image height of H1 and the relative illumination of the light spot corresponding to the initial prism after shaving (e.g., 100b) at a position with an image height of H1. H2H1 is the difference between the relative illumination of the light spot corresponding to the initial prism with the concave structure (e.g., 100c) at a position with an image height of H2 and the relative illumination of the light spot corresponding to the initial prism after shaving (e.g., 100b) at a position with an image height of H2, where H1 = -H2. For example, when d0 / h0 ≤ γ, determine |ΔRI H1 -ΔRI H2 Is it less than δ?

[0100] If |ΔRI H1 -ΔRI H2 |<δ, the recessed structure 105 is set on the fourth initial surface 104 according to the position, size and shape of the recessed structure 105. By making |ΔRI H1 -ΔRI H2 |<δ can avoid vignetting in the final image, which helps improve image quality.

[0101] If |ΔRI H1 -ΔRI H2 If |≥δ, then continue to adjust the position and / or shape of the recessed structure 105. For example, if H1 is greater than or equal to 0 mm, H2 is less than or equal to 0 mm, |ΔRI H1 |less than|ΔRI H2 | and |ΔRI H1 -ΔRI H2 If |≥δ, then the position of the recessed structure 105 will be moved towards the direction of the third initial surface 103.

[0102] In an exemplary embodiment, the dimension of the recessed structure 105 in the direction parallel to the fourth initial surface 104 can be greater than 0.8 mm and less than 1.2 mm. By appropriately configuring the dimension of the recessed structure in the direction parallel to the fourth initial surface, the reliability of the prism manufactured using this method can be ensured, while also allowing the recessed structure 105 to have sufficient width, thereby reserving enough space for the matting process on the inner wall of the recessed structure 105.

[0103] In an exemplary implementation, reference Figure 5 The end of the recessed structure 105 near the first initial surface 101 can be arc-shaped, and the radius of the arc can be greater than 0.2 mm and less than 0.5 mm. By controlling the bottom of the recessed structure 105 to be arc-shaped and making the arc have a reasonable radius, it is beneficial to reduce the diffraction stray light at the bottom of the recessed structure 105.

[0104] In an exemplary implementation, reference Figure 6The end of the recessed structure 105 near the first initial surface 101 may include a first portion 1051 and a second portion 1052. The first portion 1051 may be arc-shaped, and the second portion 1052 may be a slope. The angle β between the second portion 1052 and the central axis I of the initial prism may be greater than 30° and less than 40°. Reasonably configuring the shape of the end of the recessed structure 105 near the first initial surface 101, and ensuring that the angle β between the second portion 1052 and the central axis I of the initial prism is within a certain range, helps to reduce the amount of light blocked by the recessed structure 105 from the second initial surface 102 to the first initial surface 101, ensuring the symmetry of the relative illuminance of the light spot, and resulting in uniform illuminance variation and good image quality in the final image.

[0105] By setting a recessed structure 105 on the initial prism after edge trimming, and ensuring that the recessed structure 105 has a reasonable position, size and shape, most of the stray light is blocked by the recessed structure 105, while the relative illumination of the light spot has good symmetry, avoiding dark corners in the final image and improving the image quality.

[0106] The following is combined Figure 7 The specific steps of the prism manufacturing method 1000 are illustrated with examples.

[0107] refer to Figure 7 The light enters the initial prism from a quarter position of the first initial surface 101. c1, c2 and t are determined according to α, the thickness l of the equivalent plate and the incident position of the light on the first initial surface 101. Then, the initial prism 100a is constructed based on α, c1, c2 and t.

[0108] Adjust the incident position of the light at the initial prism 100a, and determine whether the end C of the first reflection area 1021 away from the first initial surface 101 and the end D of the second reflection area 1031 away from the first initial surface 101 are symmetrical with respect to the central axis I of the initial prism. If the end C of the first reflection area 1021 away from the first initial surface 101 and the end D of the second reflection area 1031 away from the first initial surface 101 are symmetrical with respect to the central axis I of the initial prism, then cut the second initial surface 102 and the third initial surface 103 according to the end C of the first reflection area 1021 away from the first initial surface 101 and the end D of the second reflection area 1031 away from the first initial surface 101. If the end C of the first reflective region 1021 away from the first initial surface 101 and the end D of the second reflective region 1031 away from the first initial surface 101 are not symmetrical with respect to the central axis I of the initial prism, then the incident position of the light on the initial prism 100a is adjusted until the end C of the first reflective region 1021 away from the first initial surface 101 and the end D of the second reflective region 1031 away from the first initial surface 101 are symmetrical with respect to the central axis I of the initial prism; or, α is adjusted, and c1, c2 and t are re-determined based on α, l and the incident position of the light on the first initial surface 101, and the initial prism 100a is constructed based on the re-determined α, c1, c2 and t.

[0109] The position, size, and shape of the recessed structure 105 are determined based on the stray light state of the light spot formed after the light rays exit from the initial prism (e.g., 100b) after cleaving, and it is determined whether d0 / h0 is less than or equal to γ, where γ ≤ 0.55. If d0 / h0 > γ, then α is adjusted, and c1, c2, and t are re-determined based on α, l, and the incident position of the light rays on the first initial surface 101, and the initial prism 100a is constructed based on the re-determined α, c1, c2, and t. If d0 / h0 ≤ γ, then |ΔRI| is determined. H1 -ΔRI H2 |Is it less than δ, where δ≤3? If |ΔRI H1 -ΔRI H2 If |<δ, then the recessed structure 105 is set on the initial prism (e.g., the fourth initial surface 104) after edge trimming, according to the position, size, and shape of the recessed structure 105. The initial prism (e.g., 100c) after setting the recessed structure 105 can be the final prism. If |ΔRI H1 -ΔRI H2 If |≥δ, then continue to adjust the position and / or shape of the recessed structure 105.

[0110] A second aspect of this application provides a prism 200. Figure 8 and Figure 9Schematic diagrams of the structure of a prism 200 according to an exemplary embodiment of this application are shown. The prism 200 can be manufactured using the prism manufacturing method 1000 described in the first aspect of this application. The prism 200 can be applied, for example, to an optical lens, which can be, for example, a telephoto lens.

[0111] refer to Figure 8 and Figure 9 The prism 200 may include a first surface 201 and a second surface 202 that are parallel to each other. The prism 200 may also include a third surface 203 and a fourth surface 204, which can be used to connect the first surface 201 and the second surface 202. The first surface 201 of the prism 200 may be provided with a recessed structure 205. By providing the recessed structure 205 on the first surface of the prism, most of the stray light can be blocked by the recessed structure 205, reducing the stray light risk of the prism and the optical lens including the prism, and improving the imaging quality of the prism and the optical lens including the prism.

[0112] The second surface 202 of the prism may include an incident area and an exit area spaced apart. Light enters the prism along the first optical axis A through the incident area of ​​the second surface of the prism, is reflected by the third surface 203 of the prism to the second surface 202, is then reflected by the second surface 202 to the fourth surface 204 of the prism, and is finally reflected by the fourth surface 204 to the exit area of ​​the second surface of the prism and exits along the second optical axis B through the exit area.

[0113] In an exemplary implementation, reference Figure 8 and Figure 9 At least a portion of the second surface 202 may be spaced apart from the third surface 203 and the fourth surface 204. That is, at least a portion of the second surface 202 is not connected to the third surface 203 and the fourth surface 204. By making at least a portion of the second surface 202 spaced apart from the third surface 203 and the fourth surface 204, the size of the prism in the direction parallel to the second surface 202 can be further reduced, which is beneficial for miniaturizing the prism and assembling modules, and avoids stray light formed by multiple reflections of light at the sharp corners of the prism (e.g., the ends of the second surface 202).

[0114] In an exemplary implementation, reference Figure 8 and Figure 9 The angle ε1 between the plane containing the second surface 202 and the plane containing the third surface 203 can be the same as the angle ε2 between the plane containing the second surface 202 and the plane containing the fourth surface 204. For example, ε1 = ε2 = α, where α can be greater than or equal to 30° and less than or equal to 40°.

[0115] In an exemplary embodiment, the prism 200 can be a trapezoidal prism. The size of the first surface 201 in the direction perpendicular to the first optical axis A is smaller than the size of the second surface 202 in the direction perpendicular to the first optical axis A.

[0116] In an exemplary embodiment, the ratio of the size d of the recessed structure 205 in the direction perpendicular to the first surface 201 to the distance h from the first surface 201 to the second surface 202 can be less than or equal to 0.55. In an example, 0.3 < d / h ≤ 0.55. By making the recessed structure 205 have a reasonable depth, it is possible to ensure as much as possible that stray light is blocked by the recessed structure 205.

[0117] In an exemplary embodiment, the size of the recessed structure 205 in the direction parallel to the first surface 201 can be greater than 0.8 mm and less than 1.2 mm. By reasonably configuring the size of the recessed structure 205 in the direction parallel to the first surface 201, while ensuring the reliability of the prism, it is possible to make the recessed structure 205 have a sufficient width, thereby reserving sufficient space for the light extinction process on the inner wall of the recessed structure 205.

[0118] In an exemplary embodiment, the light spot formed after the light exits the prism can satisfy: |ΔRI H1 -ΔRI H2 | < δ, δ ≤ 3, where ΔRI H1 is the difference between the relative illuminance of the light spot corresponding to the prism 200 at the position where the image height is H1 and the relative illuminance of the light spot corresponding to the prism without the recessed structure at the position where the image height is H1, and ΔRI H2 is the difference between the relative illuminance of the light spot corresponding to the prism 200 at the position where the image height is H2 and the relative illuminance of the light spot corresponding to the prism without the recessed structure at the position where the image height is H2, and H1 = -H2.

[0119] In an exemplary embodiment, referring to Figure 8 , the end of the recessed structure 205 close to the second surface 202 can be arc-shaped, and the radius of the arc can be greater than 0.2 mm and less than 0.5 mm. By controlling the bottom of the recessed structure 205 to be arc-shaped and making the arc have a reasonable radius, it is beneficial to reduce the diffracted stray light at the bottom of the recessed structure 205.

[0120] In an exemplary embodiment, referring to Figure 9The end of the recessed structure 205 near the second surface 202 may include a first portion 2051 and a second portion 2052. The first portion 2051 may be arc-shaped, and the second portion 2052 may be a slope. The angle β between the second portion 2052 and the central axis of the prism may be greater than 30° and less than 40°. By rationally configuring the shape of the end of the recessed structure 205 near the second surface 202, and ensuring that the angle β between the second portion 2052 and the central axis of the prism is within a certain range, it is beneficial to reduce the amount of light blocked by the recessed structure 205 from the light reflected from the third surface 203 to the second surface 202, ensuring the symmetry of the relative illuminance of the light spot, and resulting in uniform illuminance variation and good image quality in the final image.

[0121] In an exemplary embodiment, the prism 200 may be made of glass.

[0122] This application provides a recessed structure 205 on the first surface 201 of the prism, and makes the recessed structure 205 have a reasonable position, size and shape. While ensuring that stray light is blocked by the recessed structure 205, it can make the relative illumination of the light spot formed after the light exits from the prism have good symmetry, avoid the dark corner of the final image, and help improve the image quality.

[0123] refer to Figure 10 , Figure 14 and Figure 17 A third aspect of this application provides an optical lens that may include an imaging lens group G1, a prism P, and an imaging plane IMA. The imaging lens group G1 and the imaging plane IMA may be located on the same side of the prism P and spaced apart from each other. The prism P may be, for example, the prism described in the second aspect of this application; that is, the prism P may include a first surface and a second surface that are parallel to each other, as well as a third surface and a fourth surface for connecting the first surface and the second surface. The first surface of the prism P may have a recessed structure. The imaging lens group G1 and the imaging plane IMA may be located on the side of the prism P away from its first surface and spaced apart from each other.

[0124] In an exemplary embodiment, the imaging lens group G1 includes, sequentially from the object side to the image side along the first optical axis A, a first lens E1, a second lens E2, a third lens E3, and a fourth lens E4. Among the first lens E1 to the fourth lens E4, any two adjacent lenses may have a gap distance, which may be, for example, an air gap.

[0125] In an exemplary embodiment, the first lens E1 may have positive optical power, and its object-side surface may be convex, as may its image-side surface. By configuring the first lens E1 with the above-described structure, light rays can be converged, reducing the aperture of the rear lens (e.g., the second lens E2), thereby reducing the overall vertical height of the optical lens. The vertical height may be the height in a direction perpendicular to the first optical axis A.

[0126] In an exemplary embodiment, the second lens E2 may have positive optical power, with its object-side surface being convex and its image-side surface being concave. By configuring the second lens E2 with the above-described structure, light can be further converged, reducing the aperture of the rear lens (e.g., the third lens E3), thereby reducing the overall longitudinal height of the optical lens. The longitudinal height may be the height in a direction perpendicular to the first optical axis A.

[0127] In an exemplary embodiment, the third lens E3 may have negative optical power, with its object-side surface being convex and its image-side surface being concave. By configuring the third lens E3 with the above-described structure, it is beneficial to reduce chromatic aberration and improve the imaging quality of the optical lens.

[0128] In an exemplary embodiment, the fourth lens E4 may have negative optical power, with its object-side surface being convex and its image-side surface being concave. By configuring the fourth lens E4 in the above-described structure, it is beneficial to reduce chromatic aberration and improve the imaging quality of the optical lens.

[0129] In an exemplary embodiment, the on-axis distance from the image-side surface of the fourth lens E4 to the first surface of the prism P can be greater than the on-axis distance from the image-side surface of the fourth lens E4 to the second surface of the prism P.

[0130] In an exemplary embodiment, prism P can be a trapezoidal prism. The dimension of the first surface of prism P in the direction perpendicular to the first optical axis A can be smaller than the dimension of the second surface of prism P in the direction perpendicular to the first optical axis A.

[0131] In an exemplary embodiment, the angle between the plane containing the second surface of prism P and the plane containing the third surface of prism P can be the same as the angle between the plane containing the second surface of prism P and the plane containing the fourth surface of prism P. For example, the angle can be greater than or equal to 30° and less than or equal to 40°.

[0132] In an exemplary embodiment, light rays emitted from the fourth lens E4 can enter prism P along the first optical axis A via the incident area of ​​the second surface of the prism, and undergo multiple reflections inside prism P. The reflected light then exits along the second optical axis B via the exit area of ​​the second surface of the prism. The number of reflections inside the prism is related to the aperture sizes of the first and second surfaces of prism P and the distance between the first and second surfaces of prism P.

[0133] In an exemplary embodiment, the light rays emitted from the fourth lens E4 can enter the prism P through the incident area of the second surface of the prism along the first optical axis A, and are reflected by the third surface of the prism P to the second surface of the prism P, then reflected by the second surface of the prism P to the fourth surface of the prism P, and finally reflected by the fourth surface to the exit area of the second surface of the prism and exit along the second optical axis B through the exit area. It should be understood that the number of reflections of the light rays inside the prism being 3 is only exemplary, and the present application does not make specific limitations thereto.

[0134] In an exemplary embodiment, the optical lens may further include an aperture stop. The aperture stop can be disposed between the object side and the first lens E1.

[0135] In an exemplary embodiment, the optical lens may further include an optical element E5. The optical element E5 may be, for example, a filter, and the optical element E5 can be disposed between the prism P and the imaging surface IMA.

[0136] In an exemplary embodiment, the total effective focal length f of the optical lens can satisfy: 20 mm < f < 28 mm.

[0137] In an exemplary embodiment, the number of lenses having a refractive power in the optical lens can be four.

[0138] In an exemplary embodiment, the dimension d of the recessed structure of the prism P in the direction perpendicular to the first surface and the distance h between the first surface and the second surface of the prism P can satisfy: 0.3 < d / h ≤ 0.55. By controlling the above conditional formula, it is possible to make the recessed structure on the prism have a reasonable depth, while ensuring the reliability of the prism, as much as possible ensuring that stray light is blocked by the recessed structure, thereby improving the imaging quality of the optical lens. If d / h ≤ 0.3, the depth of the recessed structure is too small to effectively remove the stray light inside the prism, and the imaging quality of the optical lens is poor. If d / h > 0.55, the proportion of the depth of the recessed structure in the thickness of the prism is too large, and the recessed structure will block part of the effective light rays, and the relative illuminance of the optical lens drops more, and there is vignetting when the optical lens finally forms an image, affecting the imaging quality of the optical lens. At the same time, the prism is fragile in the drop test, and the reliability of the prism is poor.

[0139] In an exemplary embodiment, the total effective focal length f of the optical lens, the effective focal length f1 of the first lens E1, and the refractive index N1 of the first lens E1 may satisfy: 0.85 < f1×N1 / f < 0.95. By controlling the above conditional formula, it is beneficial to reasonably allocate the optical power of the optical lens and the first lens and the refractive index of the first lens, avoid the problem of large tolerance sensitivity of the optical lens caused by excessive concentration of the optical power of the optical lens, and avoid the problem of difficult processing and forming of the first lens caused by the refractive index of the first lens being too extreme.

[0140] In an exemplary embodiment, the effective focal length f2 of the second lens E2, the central thickness CT2 of the second lens E2 on the first optical axis, and the spacing distance T23 between the second lens E2 and the third lens E3 on the first optical axis may satisfy: 70.75 < f2 / CT2 + f2 / T23 < 110.35; and the effective focal length f2 of the second lens E2 and the spacing distance T23 between the second lens E2 and the third lens E3 on the first optical axis may satisfy: 53.2 < f2 / T23 ≤ 93.2. Reasonably configuring the ratio of the effective focal length of the second lens to the spacing distance between the second lens and the third lens and the ratio of the effective focal length of the second lens to the sum of the central thickness of the second lens and its spacing distance is beneficial to restricting the contribution of the second lens to the coma of the optical lens, and effectively balancing the coma generated by the first lens, thereby improving the imaging quality of the optical lens.

[0141] In an exemplary embodiment, the total effective focal length f of the optical lens and the curvature radius R3 of the object side surface of the second lens E2 may satisfy: 3.8 < f / R3 ≤ 4.2; and the total effective focal length f of the optical lens, the curvature radius R3 of the object side surface of the second lens E2, and the curvature radius R4 of the image side surface of the second lens E2 may satisfy: 5.4 < f / R4 + f / R3 < 5.95. Reasonably configuring the ratio of the total effective focal length of the optical lens to the curvature radius of the object side surface of the second lens and the ratio of the total effective focal length of the optical lens to the sum of the curvature radii of the object side surface and the image side surface of the second lens is beneficial to restricting the contribution of the second lens to the spherical aberration of the optical lens, reducing the aberration of the optical lens, and improving the imaging quality of the optical lens.

[0142] In an exemplary embodiment, the combined focal length f12 of the first lens E1 and the second lens E2, the central thickness CT1 of the first lens E1 on the first optical axis, and the central thickness CT2 of the second lens E2 on the first optical axis satisfy: 2.7 < f12 / (CT1 + CT2) < 2.95. Reasonably configuring the ratio of the combined focal length of the first lens and the second lens to the sum of the central thicknesses of the first lens and the second lens can improve the processability of the first lens, and restrict the contribution of the second lens to the spherical aberration of the optical lens, ensuring good imaging quality of the optical lens on the axis.

[0143] In an exemplary embodiment, the effective focal length f3 of the third lens E3, the refractive index N3 of the third lens E3, and the radius of curvature R5 of the object side surface of the third lens E3 may satisfy: -3.4 < f3×N3 / R5 < -2.25. By controlling the above conditional formula, it is beneficial to constrain the deflection angle of the marginal field at the third lens and effectively reduce the sensitivity of the optical lens.

[0144] In an exemplary embodiment, the central thickness CT3 of the third lens E3 on the first optical axis and the spacing distance T34 between the third lens E3 and the fourth lens E4 on the first optical axis may satisfy: 1.9 ≤ T34 / CT3 < 2.2. Reasonably configuring the ratio of the spacing distance between the third lens and the fourth lens to the central thickness of the third lens is beneficial for the uniform distribution of the lens sizes, improving the assembly stability of the optical lens, reducing the aberration of the optical lens, shortening the total length of the optical lens, and achieving miniaturization of the optical lens.

[0145] In an exemplary embodiment, the effective focal length f 4 of the fourth lens E4 and the radius of curvature R7 of the object side surface of the fourth lens E4 may satisfy: -3.15 < R7 / f4 < -1.5. Reasonably configuring the ratio of the radius of curvature of the object side surface of the fourth lens to the effective focal length of the fourth lens can effectively balance the astigmatism of the optical lens, ensure that the optical lens has good imaging quality, and at the same time avoid the problem of difficult processing and forming of the fourth lens caused by excessive bending of the object side surface of the fourth lens.

[0146] In an exemplary embodiment, the radius of curvature R8 of the image side surface of the fourth lens E4 and the central thickness CT4 of the fourth lens E4 on the first optical axis may satisfy: 11.45 < R8 / CT4 < 12.2. Reasonably configuring the ratio of the radius of curvature of the image side surface of the fourth lens to the central thickness of the fourth lens is beneficial for constraining the principal ray incident angle of the optical lens within an appropriate range and ensuring that the optical lens achieves a large imaging height.

[0147] In an exemplary embodiment, the central thickness CT2 of the second lens E2 on the first optical axis and the spacing distance T23 between the second lens E2 and the third lens E3 on the first optical axis may satisfy: 3.0 < CT2 / T23 < 5.45. Reasonably configuring the ratio of the central thickness of the second lens to the spacing distance between the second lens and the third lens can effectively constrain the field curvature and distortion range of the optical lens and improve the imaging quality of the optical lens.

[0148] In an exemplary embodiment, the effective focal length f1 of the first lens E1, the Abbe number V1 of the first lens E1, and the curvature radius R11 of the object side surface of the first lens E1 may satisfy: 142.9 < f1×V1 / R1 < 161.55. By controlling the above conditional formula, it is beneficial to correct the lateral chromatic aberration of the optical lens, improve the imaging quality of the optical lens, and at the same time, it can effectively constrain the surface shape of the first lens, making the first lens have good processing and forming properties.

[0149] In an exemplary embodiment, the combined focal length f23 of the second lens E2 and the third lens E3 and the interval distance T23 between the second lens E2 and the third lens E3 on the first optical axis may satisfy: 130.85 < f23 / T23 < 236.65. Reasonably configuring the ratio of the combined focal length of the second lens and the third lens to the interval distance between the second lens and the third lens is beneficial to shortening the total length of the optical lens. While the optical lens satisfies the telephoto characteristics, it ensures that the optical lens meets the requirements of miniaturization, and at the same time, it is beneficial to adjust the structure of the optical lens and reduce the processing and assembly difficulty of the lens.

[0150] In an exemplary embodiment, the total effective focal length f of the optical lens and the effective focal length f2 of the second lens E2 may satisfy: 1.25 < f / f2 < 1.45. Reasonably configuring the ratio of the total effective focal length of the optical lens to the effective focal length of the second lens can constrain the optical power of the second lens within an appropriate range, thereby increasing the total effective focal length of the optical lens and at the same time balancing the field curvature of the optical lens.

[0151] In an exemplary embodiment, the effective focal length f1 of the first lens E1 and the effective focal length f2 of the second lens E2 may satisfy: 0.7 < f1 / f2 < 0.85. Reasonably configuring the ratio of the effective focal length of the first lens to the effective focal length of the second lens can make the object-side end lens of the optical lens have sufficient converging ability, and the light rays are focused at an appropriate focusing position, thereby shortening the total length of the optical lens and ensuring that the optical lens meets the requirements of miniaturization.

[0152] The optical lens according to the above embodiment of the present application may employ four lenses and a prism. By reasonably allocating parameters such as each lens and the prism, the light rays can be reflected multiple times inside the prism, achieving the telephoto characteristics of the optical lens while ensuring the miniaturization of the optical lens, and at the same time, improving the imaging quality of the optical lens.

[0153] In an embodiment of the present application, at least one of the surfaces of each lens among the second lens to the fourth lens is an aspherical surface. The characteristic of an aspherical lens is that the curvature continuously changes from the center of the lens to the periphery of the lens. Different from a spherical lens with a constant curvature from the center of the lens to the periphery, an aspherical lens has better curvature radius characteristics and has the advantages of improving distortion aberration and improving astigmatism aberration. After using an aspherical lens, it is possible to eliminate the aberration that appears during imaging as much as possible, thereby improving the imaging quality.

[0154] Reference Figure 10 、 Figure 14 and Figure 17 According to

[0155] the fourth aspect of the present application provides an optical lens, which may include an imaging lens group G1, a prism P, and an imaging surface IMA. The imaging lens group G1 and the imaging surface IMA may be located on the same side of the prism P. The prism P may be, for example, the prism described in the second aspect of the present application. The imaging lens group G1 sequentially includes a first lens E1, a second lens E2, a third lens E3, and a fourth lens E4 along the first optical axis A from the object side to the image side. The first lens E1 has a positive optical power, its object side surface is convex, and its image side surface is convex. The second lens E2 has a positive optical power, its object side surface is convex, and its image side surface is concave. The third lens E3 has a negative optical power, its object side surface is convex, and its image side surface is concave. The fourth lens E4 has a negative optical power, its object side surface is convex, and its image side surface is concave. The number of lenses having optical power in the optical lens may be four.

[0156] Reference Figure 10 、 Figure 14 and Figure 17, a fifth aspect of the present application provides an optical lens, which may include an imaging lens group G1, a prism P, and an imaging surface IMA. The imaging lens group G1 and the imaging surface IMA may be located on the same side of the prism P. The prism P may be, for example, the prism described in the second aspect of the present application. The imaging lens group G1 sequentially includes a first lens E1, a second lens E2, a third lens E3, and a fourth lens E4 along the first optical axis A from the object side to the image side. The first lens E1 has a positive optical power, its object side surface is convex, and its image side surface is convex. The second lens E2 has a positive optical power, its object side surface is convex, and its image side surface is concave. The third lens E3 has a negative optical power, its object side surface is convex, and its image side surface is concave. The fourth lens E4 has a negative optical power, its object side surface is convex, and its image side surface is concave. The number of lenses with optical power in the optical lens may be four.

[0157] The total effective focal length f of the optical lens and the effective focal length f2 of the second lens E2 may satisfy: 1.25 < f / f2 < 1.45. The first lens and the second lens of the present application have positive optical powers, and both of their object side surfaces are convex, which can converge light rays, reduce the aperture of the rear lenses, and thus reduce the longitudinal height of the entire optical lens; the third lens and the fourth lens have negative optical powers, and both the third lens and the fourth lens are convex-concave, which is beneficial to reducing chromatic aberration and improving the imaging quality of the optical lens. At the same time, by reasonably configuring the ratio of the total effective focal length of the optical lens to the effective focal length of the second lens, the optical power of the second lens can be constrained within an appropriate range, thereby increasing the total effective focal length of the optical lens and also balancing the field curvature of the optical lens.

[0158] Reference Figure 10 , Figure 14 and Figure 17 , a sixth aspect of the present application provides an optical lens, which may include an imaging lens group G1, a prism P, and an imaging surface IMA. The imaging lens group G1 and the imaging surface IMA may be located on the same side of the prism P. The prism P may be, for example, the prism described in the second aspect of the present application. The imaging lens group G1 sequentially includes a first lens E1, a second lens E2, a third lens E3, and a fourth lens E4 along the first optical axis A from the object side to the image side. The first lens E1 has a positive optical power, its object side surface is convex, and its image side surface is convex. The second lens E2 has a positive optical power, its object side surface is convex, and its image side surface is concave. The third lens E3 has a negative optical power, its object side surface is convex, and its image side surface is concave. The fourth lens E4 has a negative optical power, its object side surface is convex, and its image side surface is concave. The number of lenses with optical power in the optical lens may be four.

[0159] The effective focal length f1 of the first lens E1 and the effective focal length f2 of the second lens E2 may satisfy: 0.7 < f1 / f2 < 0.85. The first lens and the second lens of the present application have positive optical powers, and the object sides thereof are convex surfaces, which can converge light rays, reduce the aperture of the rear lens, and further reduce the longitudinal height of the entire optical lens; the third lens and the fourth lens have negative optical powers, and both the third lens and the fourth lens are convex-concave, which is beneficial to reducing chromatic aberration and improving the imaging quality of the optical lens. At the same time, by reasonably configuring the ratio of the effective focal length of the first lens to the effective focal length of the second lens, the object-side end lens of the optical lens can have sufficient converging ability, and the light rays are focused at an appropriate focusing position, thereby shortening the total length of the optical lens and ensuring that the optical lens meets the requirements of miniaturization.

[0160] Those skilled in the art should understand that without departing from the technical solutions claimed in the present application, the number of lenses constituting the optical lens can be changed to obtain the various results and advantages described in this specification.

[0161] The specific embodiments of the optical lens applicable to the above embodiments will be further described below with reference to the accompanying drawings.

[0162] Example 1

[0163] The following refers to Figure 10 、 Figure 11A 、 Figure 11B 、 Figure 11C 、 Figure 12A 、 Figure 12B 、 Figure 12C 、 Figure 12D and Figure 13 describe the optical lens according to Embodiment 1 of the present application.

[0164] As Figure 10 shown, the optical lens may include an imaging lens group G1, a prism P, and an imaging surface IMA. The imaging lens group G1 and the imaging surface IMA may be located on the same side of the prism P. The imaging lens group G1 may sequentially include a first lens E1, a second lens E2, a third lens E3, and a fourth lens E4 along the first optical axis A from the object side to the image side. The aperture stop STO may be disposed on the object side of the first lens E1.

[0165] The first lens E1 has a positive optical power, its object side S1 is a convex surface, and its image side S2 is a convex surface. The second lens E2 has a positive optical power, its object side S3 is a convex surface, and its image side S4 is a concave surface. The third lens E3 has a negative optical power, its object side S5 is a convex surface, and its image side S6 is a concave surface. The fourth lens E4 has a negative optical power, its object side S7 is a convex surface, and its image side S8 is a concave surface.

[0166] In the example, light rays exiting from the fourth lens E4 enter the prism P along the first optical axis A, and after multiple reflections (e.g., 3 times) inside the prism P, exit along the second optical axis B. An optical element E5, which may be, for example, a filter, may also be included between the prism P and the imaging surface IMA. Light from the object passes sequentially through the first lens E1, the second lens E2, the third lens E3, and the fourth lens E4, and after multiple reflections (e.g., 3 times) inside the prism P, passes through the optical element E5 and is imaged onto the imaging surface IMA.

[0167] Table 1 shows the basic parameters of the optical lens of Example 1, where the units for radius of curvature and thickness / distance are millimeters (mm).

[0168]

[0169]

[0170] Table 1

[0171] In this embodiment, the object-side surface and image-side surface of any one of the second lens E2 to the fourth lens E4 are aspherical surfaces, and the surface shape x of each aspherical lens can be defined using, but is not limited to, the following aspherical formula:

[0172]

[0173] Where x is the distance vector from the vertex of the aspherical surface at a height h along the optical axis; 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 in Table 1 above); k is the conic coefficient; Ai is the i-th order correction coefficient of the aspherical surface. Table 2 gives the higher-order coefficients A4, A6, A8, A10, A12, A14, A16, A18, A20, A22, A24, A26, A28 and A30 that can be used for the aspherical surfaces S3-S8 in Example 1.

[0174] Face number A4 A6 A8 A10 A12 A14 A16 S3 1.65E-01 1.06E-02 -1.27E-02 -1.01E-02 -5.24E-03 -1.84E-03 -4.82E-04 S4 2.05E-01 .2.88E-02 -1.47E-02 .8.46E-03 -4.74E-03 -1.05E-03 2.79E-04 S5 3.83E-02 -9.29E-04 2.22E-02 .7.93E-05 -3.04E-03 -4.52E-04 2.26E-04 S6 2.79E-02 .7.90E-03 1.99E-02 2.88E-03 -9.14E-04 1.13E-04 5.17E-04 S7 9.63E-02 -4.90E-02 9.65E-03 -1.20E-03 .2.07E-04 -9.83E-05 2.13E-04 S8 3.40E-02 .2.96E-02 4.81E-03 .8.65E-04 .2.24E-05 -1.88E-05 6.60E-05 Face number A18 A20 A22 A24 A26 A28 A30 S3 1.88E-04 2.15E-04 1.56E-04 2.62E-05 0.00E+00 0.00E+00 0.00E+00 S4 6.36E-04 8.68E-05 .2.44E-05 -1.37E-04 .6.65E-06 1.88E-05 1.71E-05 S5 -3.09E-04 -1.61E-04 -3.37E-05 -4.58E-05 .2.44E-05 1.99E-05 -2.27E-06 S6 .2.11E-04 -1.08E-04 .3.02E-05 2.97E-06 -4.01E-05 0.00E+00 0.00E+00 S7 -8.06E-05 .2.46E-05 7.68E-06 8.35E-06 -1.31E-05 5.42E-06 .5.27E-08 S8 .6.56E-06 .2.25E-05 1.16E-05 .2.45E-06 0.00E+00 0.00E+00 0.00E+00

[0175] Table 2

[0176] Figure 11A The on-axis chromatic aberration curve of the optical lens of Embodiment 1 is shown, which indicates the deviation of the focal point of light of different wavelengths after passing through the optical lens. Figure 11B The astigmatism curve of the optical lens of Embodiment 1 is shown, which represents the meridional image plane curvature and sagittal image plane curvature corresponding to different image heights. Figure 11C The magnification chromatic aberration curve of the optical lens of Embodiment 1 is shown, which represents the deviation of different image heights on the imaging plane after light passes through the lens. According to Figures 11A to 11CIt can be seen that the optical lens of Embodiment 1 can achieve good imaging quality.

[0177] Figure 12A Fig. shows the stray light simulation diagram of the optical lens of Embodiment 1 when d / h = 0. Figure 12B Fig. shows the stray light simulation diagram of the optical lens of Embodiment 1 when d / h = 0.22. Figure 12C Fig. shows the stray light simulation diagram of the optical lens of Embodiment 1 when d / h = 0.50. Figure 12D Fig. shows the stray light simulation diagram of the optical lens of Embodiment 1 when d / h = 0.60. Figure 13 Fig. shows the relative illuminance of the optical lens of Embodiment 1 of the present application under different d / h. According to Figures 12A to 12D and Figure 13 It can be seen that by controlling the optical lens to satisfy 0.3 < d / h ≤ 0.55, the stray light of the optical lens can be significantly improved, and the depression structure can be avoided from blocking part of the effective light, that is, the relative illuminance drop of the optical lens can be avoided, and the imaging quality of the optical lens can be improved.

[0178] Example 2

[0179] The following refers to Figure 14 , Figure 15A , Figure 15B , Figure 15C , Figure 16A and Figure 16B describe the optical lens according to Embodiment 2 of the present application.

[0180] As Figure 14 shown, the optical lens may include an imaging lens group G1, a prism P, and an imaging surface IMA. The imaging lens group G1 and the imaging surface IMA may be located on the same side of the prism P. The imaging lens group G1 may sequentially include a first lens E1, a second lens E2, a third lens E3, and a fourth lens E4 along the first optical axis A from the object side to the image side. The aperture stop STO may be disposed on the object side of the first lens E1.

[0181] The first lens E1 has a positive optical power, its object side surface S1 is a convex surface, and its image side surface S2 is a convex surface. The second lens E2 has a positive optical power, its object side surface S3 is a convex surface, and its image side surface S4 is a concave surface. The third lens E3 has a negative optical power, its object side surface S5 is a convex surface, and its image side surface S6 is a concave surface. The fourth lens E4 has a negative optical power, its object side surface S7 is a convex surface, and its image side surface S8 is a concave surface.

[0182] In the example, the light rays emitted from the fourth lens E4 enter the prism P along the first optical axis A, and after being reflected multiple times (e.g., 3 times) inside the prism P, they are emitted along the second optical axis B. An optical element E5 disposed on the second optical axis B may also be included between the prism P and the imaging surface IMA. The optical element E5 may be, for example, a filter. The light from the object sequentially passes through the first lens E1, the second lens E2, the third lens E3, and the fourth lens E4, and after being reflected multiple times (e.g., 3 times) inside the prism P, it passes through the optical element E5 and is imaged on the imaging surface IMA.

[0183] Table 3 shows the basic parameter table of the optical lens of Example 2, where the units of the radius of curvature and the thickness / distance are both millimeters (mm).

[0184]

[0185] Table 3

[0186] In this embodiment, the object side and the image side of any one of the second lens E2 to the fourth lens E4 are both aspherical surfaces. Table 4 gives the higher-order term coefficients A4, A6, A8, A10, A12, A14, A16, A18, A20, A22, A24, A26, A28, and A30 of the aspherical surfaces S3 - S8 that can be used in Example 2.

[0187]

[0188]

[0189] Table 4

[0190] Figure 15A Shows the axial chromatic aberration curve of the optical lens of Example 2, which represents the deviation of the convergence points of light rays of different wavelengths after passing through the optical lens. Figure 15B Shows the astigmatism curve of the optical lens of Example 2, which represents the meridional image plane curvature and the sagittal image plane curvature corresponding to different image heights. Figure 15C Shows the longitudinal chromatic aberration curve of the optical lens of Example 2, which represents the deviation of different image heights on the imaging surface after the light rays pass through the lens. According to Figures 15A to 15C It can be seen that the optical lens of Example 2 can achieve good imaging quality.

[0191] Figure 12A Shows the stray light simulation diagram of the optical lens of Example 2 when d / h = 0, Figure 12B Shows the stray light simulation diagram of the optical lens of Example 2 when d / h = 0.52. According to Figure 12A and Figure 12B It can be seen that by controlling the optical lens to satisfy 0.3 < d / h ≤ 0.55, the stray light of the optical lens can be significantly improved.

[0192] Example 3

[0193] The following is for reference Figure 17 , Figure 18A , Figure 18B , Figure 18C , Figure 19A , Figure 19B , Figure 20A , Figure 20B , Figure 21A and Figure 21B The optical lens according to Embodiment 3 of this application is described.

[0194] like Figure 17 As shown, the optical lens may include an imaging lens group G1, a prism P, and an imaging plane IMA. The imaging lens group G1 and the imaging plane IMA may be located on the same side of the prism P. The imaging lens group G1 may include a first lens E1, a second lens E2, a third lens E3, and a fourth lens E4 sequentially from the object side to the image side along the first optical axis A. The aperture stop STO may be disposed on the object side of the first lens E1.

[0195] The first lens E1 has positive optical power, with its object-side surface S1 being convex and its image-side surface S2 being convex. The second lens E2 has positive optical power, with its object-side surface S3 being convex and its image-side surface S4 being concave. The third lens E3 has negative optical power, with its object-side surface S5 being convex and its image-side surface S6 being concave. The fourth lens E4 has negative optical power, with its object-side surface S7 being convex and its image-side surface S8 being concave.

[0196] In the example, light rays exiting from the fourth lens E4 enter the prism P along the first optical axis A, and after multiple reflections (e.g., 3 times) inside the prism P, exit along the second optical axis B. An optical element E5, which may be, for example, a filter, may also be included between the prism P and the imaging surface IMA. Light from the object passes sequentially through the first lens E1, the second lens E2, the third lens E3, and the fourth lens E4, and after multiple reflections (e.g., 3 times) inside the prism P, passes through the optical element E5 and is imaged onto the imaging surface IMA.

[0197] Table 5 shows the basic parameters of the optical lens of Example 3, where the units for radius of curvature and thickness / distance are millimeters (mm).

[0198]

[0199]

[0200] Table 5

[0201] In this embodiment, the object side and the image side of any one of the second lens E2 to the fourth lens E4 are aspherical surfaces. Table 6 shows the higher-order coefficients A4, A6, A8, A10, A12, A14, A16, A18, A20, A22, A24, A26, A28, and A30 of the aspherical surfaces S3 - S8 in Embodiment 3.

[0202] Face number A4 A6 A8 A10 A12 A14 A16 S3 1.50E-01 2.18E-02 1.51E-04 -1.74E-03 -1.14E-03 .3.77E-04 -2.82E-04 S4 1.66E-01 -9.25E-03 -1.46E-03 -2.71E-04 .8.43E-04 .3.70E-04 -3.66E-04 S5 2.40E-02 -1.32E-02 1.37E-02 2.28E-03 -1.13E-03 -4.45E-04 2.59E-04 S6 2.65E-02 -1.62E-02 1.17E-02 2.82E-03 -3.90E-04 .5.41E-04 4.20E-04 S7 6.88E-02 .3.95E-02 6.87E-03 -4.42E-05 -1.56E-04 .3.01E-04 2.13E-04 S8 4.57E-02 .2.05E-02 3.62E-03 .3.85E-04 9.82E-06 -1.28E-04 9.04E-05 Face number A18 A20 A22 A24 A26 A28 A30 S3 -5.37E-05 -5.59E-05 -4.17E-06 -4.25E-06 0.00E+00 0.00E+00 0.00E+00 S4 1.17E-04 -3.38E-05 7.91E-05 3.09E-05 -1.48E-05 -6.31E-06 -1.68E-05 S5 2.94E-05 1.76E-05 3.89E-05 2.75E-05 -3.17E-05 -1.74E-06 -7.36E-06 S6 .5.45E-05 6.33E-05 -1.54E-05 3.17E-05 -1.07E-05 0.00E+00 0.00E+00 S7 -6.09E-05 3.33E-05 -1.56E-05 9.00E-06 .6.58E-07 -3.75E-06 2.07E-06 S8 -3.48E-05 1.52E-05 -9.76E-06 4.80E-06 0.00E+00 0.00E+00 0.00E+00

[0203] Table 6

[0204] Figure 18A shows the axial chromatic aberration curve of the optical lens in Embodiment 3, which represents the deviation of the convergence points of light rays with different wavelengths after passing through the optical lens. Figure 18B shows the astigmatism curve of the optical lens in Embodiment 3, which represents the meridional image plane curvature and the sagittal image plane curvature corresponding to different image heights. Figure 18C shows the lateral chromatic aberration curve of the optical lens in Embodiment 3, which represents the deviation of different image heights on the imaging plane after the light rays pass through the lens. According to Figures 18A to 18C it can be seen that the optical lens in Embodiment 3 can achieve good imaging quality.

[0205] The angle between the plane of the second surface and the plane of the third surface of the prism P is the same as the angle between the plane of the second surface and the plane of the fourth surface of the prism P, and both are α. When α is different, the values of D1, D2, D3, and D4 in Table 5 are also different. α can be 34.0°, 32.0°, or 36.0°. Table 7 shows the values of D1, D2, D3, and D4 at different α values.

[0206] α(°) 34.0 32.0 36.0 D1 3.6374 3.4761 3.8197 D2 -9.7099 .7.9297 -12.3606 D3 4.8397 5.9749 2.9180 D4 -1.8130 .2.6192 -0.9017

[0207] Table 7

[0208] Figure 19A shows the stray light simulation diagram of the optical lens in Embodiment 3 when α = 34.0° and d / h = 0, Figure 19B shows the stray light simulation diagram of the optical lens in Embodiment 3 when α = 34.0° and d / h = 0.51. According to Figure 19A and Figure 19B it can be seen that when α = 34.0°, by controlling the optical lens to satisfy 0.3 < d / h ≤ 0.55, the stray light of the optical lens can be significantly improved.

[0209] Figure 20A shows the stray light simulation diagram of the optical lens in Embodiment 3 when α = 32.0° and d / h = 0, Figure 20B shows the stray light simulation diagram of the optical lens in Embodiment 3 when α = 32.0° and d / h = 0.33. According to Figure 20A and Figure 20B It can be seen that when α = 32.0°, by controlling the optical lens to satisfy 0.3 < d / h ≤ 0.55, the stray light of the optical lens can be significantly improved.

[0210] Figure 21A The simulation diagram of the stray light when the optical lens of Embodiment 3 satisfies α = 36.0° and d / h = 0 is shown. Figure 21B The simulation diagram of the stray light of the optical lens when the optical lens of Embodiment 3 satisfies α = 36.0° and d / h = 0.55 is shown. According to Figure 21A and Figure 21B It can be seen that when α = 36.0°, by controlling the optical lens to satisfy 0.3 < d / h ≤ 0.55, the stray light of the optical lens can be significantly improved.

[0211] Table 8 shows RI0, RI1 and ΔRI at different image heights in the Y direction for different lenses (e.g., Lens 1, Lens 2, Lens 3), where RI0 is the relative illuminance when the lens does not have a concave structure, RI1 is the relative illuminance when the lens has a concave structure, and ΔRI = RI1 - RI0. Lenses 1 and 2 satisfy α = 34.0°. When both Lenses 1 and 2 have a concave structure, the position of the concave structure of Lens 2 is offset by 0.2 mm in the direction closer to the fourth surface of the prism P compared to Lens 1. Lens 3 satisfies α = 32.0°.

[0212]

[0213] Table 8

[0214] Table 9 shows RI0, RI1 and ΔRI at different image heights in the X direction for different lenses (e.g., Lens 1, Lens 2, Lens 3), where RI0 is the relative illuminance when the lens does not have a concave structure, RI1 is the relative illuminance when the lens has a concave structure, and ΔRI = RI1 - RI0. Lenses 1 and 2 satisfy α = 34.0°. When both Lenses 1 and 2 have a concave structure, the position of the concave structure of Lens 2 is offset by 0.2 mm in the direction closer to the fourth surface of the prism P compared to Lens 1. Lens 3 satisfies α = 32.0°.

[0215]

[0216]

[0217] Table 9

[0218] Table 10 shows the image heights RI0, RI1, and ΔRI at different diagonal directions of the imaging plane for different lenses (e.g., lens 1, lens 2, and lens 3), where RI0 is the relative illumination without the concave structure, RI1 is the relative illumination with the concave structure, and ΔRI = RI1 - RI0. Lenses 1 and 2 satisfy α = 34.0°. When both lenses 1 and 2 have concave structures, the position of the concave structure in lens 2 is offset by 0.2 mm relative to the fourth surface of prism P in lens 1. Lens 3 satisfies α = 32.0°.

[0219]

[0220] Table 10

[0221] Table 11 shows the image heights RI0, RI1, and ΔRI in the Y direction for different lenses (e.g., lens 4 and lens 5), where RI0 is the relative illumination without the concave structure, RI1 is the relative illumination with the concave structure, and ΔRI = RI1 - RI0. Lenses 4 and 5 satisfy α = 36.0°. When both lenses 4 and 5 have concave structures, the position of the concave structure in lens 5 is offset by 0.25 mm relative to the fourth surface of prism P in lens 4.

[0222]

[0223] Table 11

[0224] Table 12 shows the image heights RI0, RI1, and ΔRI in the X direction for different lenses (e.g., lens 4 and lens 5), where RI0 is the relative illumination without the concave structure, RI1 is the relative illumination with the concave structure, and ΔRI = RI1 - RI0. Lenses 4 and 5 satisfy α = 36.0°. When both lenses 4 and 5 have concave structures, the position of the concave structure in lens 5 is offset by 0.25 mm relative to the fourth surface of lens 4, closer to the prism P.

[0225]

[0226] Table 12

[0227] Table 13 shows the image heights RI0, RI1, and ΔRI at different diagonal directions of the imaging surface for different lenses (e.g., lens 4 and lens 5), where RI0 is the relative illumination when the lens does not have a concave structure, RI1 is the relative illumination when the lens has a concave structure, and ΔRI = RI1 - RI0. Lenses 4 and 5 satisfy α = 36.0°. When both lenses 4 and 5 have concave structures, the position of the concave structure of lens 5 is offset by 0.25 mm relative to the direction of lens 4 towards the fourth surface of prism P.

[0228]

[0229] Table 13

[0230] The X direction mentioned above can be, for example, a direction perpendicular to the optical axis and located in the sagittal plane, and the Y direction can be, for example, a direction perpendicular to the optical axis and located in the meridional plane. As shown in Tables 8 to 13, the recessed structures of lenses 1 and 4 intercept some of the effective light rays, which leads to poor symmetry in the relative illumination of lenses 1 and 4. By shifting the position of the recessed structure a certain distance closer to the fourth surface of prism P (for example, lenses 2 and 5), the symmetry of the relative illumination of the lenses can be improved, and vignetting can be avoided in the images formed by the lenses.

[0231] Furthermore, when the lens has a concave structure, the relative illumination drop increases with increasing α, i.e., the relative illumination drop of lens 5 > the relative illumination drop of lens 2 > the relative illumination drop of lens 3. However, the distance h between the first and second surfaces of the prism in lens 3 is relatively large, meaning the prism of lens 3 is thicker, which is detrimental to the miniaturization of optical lenses. Therefore, lens 2 has a smaller prism thickness and a smaller relative illumination drop, allowing it to achieve good image quality while maintaining miniaturization.

[0232] Table 14 shows the values ​​of parameters f, f1, f2, f3, f4, f12, f23, f34, α, h, d, etc. for each embodiment in Examples 1-3.

[0233]

[0234] Table 14

[0235] Table 15 shows the values ​​of the conditional expressions for each of the embodiments in Examples 1-3.

[0236]

[0237] Table 15

[0238] This application also provides an imaging device, whose electronic photosensitive element can be a photocoupled device (CCD) or a complementary metal oxide semiconductor device (CMOS). The imaging device can be a stand-alone imaging device such as a digital camera, or an imaging module integrated into a mobile electronic device such as a mobile phone. The imaging device is equipped with the optical lens described above.

[0239] 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. A method for manufacturing a prism, characterized in that, include: Construct an initial prism, wherein the initial prism includes a first initial surface and a second initial surface and a third initial surface connected to the first initial surface, and the side of the second initial surface away from the first initial surface is connected to the side of the third initial surface away from the first initial surface; In response to determining that the ends of the reflection regions of the second initial surface away from the first initial surface and the ends of the reflection regions of the third initial surface away from the first initial surface are symmetrical with respect to the central axis of the initial prism, the second initial surface and the third initial surface are truncated according to the ends of the two reflection regions away from the first initial surface to form a fourth initial surface parallel to the first initial surface; and Based on the stray light state of the light spot formed after the light is emitted from the initial prism after the light is cut off, a recessed structure is set on the fourth initial surface.

2. The manufacturing method according to claim 1, wherein, The construction of the initial prism includes: The structural parameters of the initial prism are determined based on the thickness of the equivalent plate corresponding to the initial prism, the angle between the first and second initial surfaces, the angle between the first and third initial surfaces, and the incident position of the light ray on the first initial surface. The incident position is one-quarter of the distance from the first initial surface. The structural parameters include the distance from the intersection of the first optical axis and the first initial surface to the first end of the first initial surface, the distance from the intersection of the second optical axis and the first initial surface to the second end of the first initial surface, and the distance between the first and second optical axes. The first optical axis is the principal optical axis of the light ray incident on the initial prism, and the second optical axis is the principal optical axis of the light ray exiting the initial prism. The initial prism is formed based on the angle between the first initial surface and the second initial surface, the angle between the first initial surface and the third initial surface, and the structural parameters of the initial prism.

3. The manufacturing method according to claim 1, wherein, The step of trimming the second initial surface and the third initial surface according to the ends of the two reflection zones away from the first initial surface includes: The second initial surface and the third initial surface are cut along a line drawn from the ends of the two reflective regions away from the first initial surface, and the fourth initial surface is parallel to the line drawn.

4. The manufacturing method according to claim 1, wherein, Also includes: Remove at least a portion of the first initial surface that is connected to the second initial surface, and remove at least a portion of the first initial surface that is connected to the third initial surface.

5. The manufacturing method according to claim 3, wherein, The step of setting a recessed structure on the fourth initial surface based on the stray light state of the light spot formed after the light rays exit from the initial prism after slicing includes: The location, size, and shape of the recessed structure are determined based on the stray light state of the light spot; and The recessed structure is disposed on the fourth initial surface according to the position, size and shape of the recessed structure.

6. A prism, characterized in that, The prism is manufactured using the manufacturing method described in any one of claims 1-5.

7. An optical lens, characterized in that, Comprising an imaging lens group, a prism as described in claim 6, and an imaging surface, wherein the imaging lens group and the imaging surface are located on the same side of the prism; wherein, The imaging lens group sequentially includes, from the object side to the image side along the first optical axis: A first lens with positive optical power, having a convex object surface and a convex image surface; A second lens with positive optical power, having a convex object surface and a concave image surface; A third lens with negative optical power, having a convex object surface and a concave image surface; and A fourth lens with negative optical power, having a convex object surface and a concave image surface; The number of lenses with optical power in the optical lens is four; The prism has a first surface and a second surface that are parallel to each other, and a recessed structure is provided on the first surface of the prism; Wherein, the dimension d of the recessed structure in the direction perpendicular to the first surface and the distance h between the first surface and the second surface of the prism satisfy: 0.3 < d / h ≤ 0.

55.

8. The optical lens according to claim 7, wherein, The total effective focal length f of the optical lens, the effective focal length f1 of the first lens, and the refractive index N1 of the first lens satisfy: 0.85 < f1×N1 / f < 0.

95.

9. The optical lens according to claim 7, wherein, The effective focal length f2 of the second lens, the central thickness CT2 of the second lens on the first optical axis, and the spacing distance T23 between the second lens and the third lens on the first optical axis satisfy: 70.75 < f2 / CT2 + f2 / T23 < 110.35; and the effective focal length f2 of the second lens and the spacing distance T23 between the second lens and the third lens on the first optical axis satisfy: 53.2 < f2 / T23 ≤ 93.

2.

10. The optical lens according to claim 7, wherein, The total effective focal length f of the optical lens and the radius of curvature R3 of the object side of the second lens satisfy: 3.8 < f / R3 ≤ 4.2; and the total effective focal length f of the optical lens, the radius of curvature R3 of the object side of the second lens, and the radius of curvature R4 of the image side of the second lens satisfy: 5.4 < f / R4 + f / R3 < 5.95.

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