New structure telephoto lens and electronic equipment

Abstract

The utility model discloses a novel structure telephoto lens and electronic equipment. The novel structure telephoto lens comprises a lens group, a prism, a filter and an imaging chip from the object side to the image side; the lens group comprises a plurality of lenses arranged in sequence; the prism comprises an incident surface, a first reflection surface, a second reflection surface, a third reflection surface, a fourth reflection surface, a fifth reflection surface and an exit surface, wherein the incident surface, the second reflection surface, the fourth reflection surface and the exit surface are the same surface; the light emitted by the lens group enters the prism from the incident surface, is reflected by the first reflection surface to the fifth reflection surface, is emitted by the exit surface, and is projected to the imaging surface of the imaging chip after passing through the filter; wherein the system focal length f' of the novel structure telephoto lens, the length X and the width Y of the effective area of ​​the imaging chip satisfy: the novel structure telephoto lens and the electronic equipment of the utility model have miniaturization, a large target surface, a large aperture and good resolution.

Description

Technical Field

[0001] The utility model relates to the technical field of optical imaging, in particular to a new-structure telephoto lens and electronic equipment. Background Art

[0002] With the development of multifunctionality of various electronic products, the camera function has become a necessary function of many electronic products, such as smart phones and tablet computers with camera functions. Therefore, the lens assembly has also become a necessary component of various electronic devices.

[0003] However, in order to achieve photography of more distant objects, the lens needs to have a longer focal length. A longer focal length means a longer optical path, which results in a larger lens and makes it difficult to use on thin and light imaging devices such as smartphones. Utility Model Content

[0004] In view of the above problems, the purpose of the present invention is to provide a new type of telephoto lens and electronic equipment, which have miniaturization, large target surface, large aperture and good resolution.

[0005] The utility model provides a novel structure telephoto lens, which comprises a lens group, a prism, a filter and an imaging chip from the object side to the image side; the lens group comprises a plurality of lenses arranged in sequence; the prism comprises an incident surface, a first reflection surface, a second reflection surface, a third reflection surface, a fourth reflection surface, a fifth reflection surface and an exit surface, wherein the incident surface, the second reflection surface, the fourth reflection surface and the exit surface are the same surface; the light emitted by the lens group enters the prism from the incident surface, is reflected by the first reflection surface, the second reflection surface, the third reflection surface, the fourth reflection surface and the fifth reflection surface, is emitted by the exit surface, and is projected to the imaging surface of the imaging chip after passing through the filter; wherein the system focal length f' of the novel structure telephoto lens, the length X and the width Y of the effective area of ​​the imaging chip satisfy:

[0006] Optionally, an angle α between the incident surface and the first reflecting surface satisfies: 21°≤α≤34°.

[0007] Optionally, the prism is a trapezoidal prism.

[0008] Optionally, the first reflecting surface and the fifth reflecting surface are provided with a reflecting film.

[0009] Optionally, the system focal length f' of the novel structure telephoto lens and the equivalent thickness H11 of the prism satisfy: 0.5≤H11 / f'≤1.2.

[0010] Optionally, the lens group includes a first lens, a second lens, a third lens and a fourth lens in sequence, the first lens has positive optical power, the second lens has negative optical power, the third lens has positive optical power, and the fourth lens has negative optical power.

[0011] Optionally, the object side surface of the first lens is a convex surface, and the second lens to the fourth lens are all meniscus lenses.

[0012] Optionally, the sag height SAG7 of the object side surface of the third lens and the sag height SAG8 of the image side surface of the third lens satisfy: 0≤SAG7≤2; 0≤SAG8≤2.

[0013] Optionally, the optical power φ3 of the third lens satisfies: |φ3|≤0.01.

[0014] The utility model also provides an electronic device, comprising the above-mentioned novel structure telephoto lens.

[0015] The utility model provides a novel structure telephoto lens and electronic equipment, wherein the light emitted from the lens group enters the prism from the incident surface, is reflected by the first reflection surface, the second reflection surface, the third reflection surface, the fourth reflection surface and the fifth reflection surface, is emitted from the exit surface, and is projected to the imaging surface of the imaging chip after passing through the filter; wherein the system focal length f' of the novel structure telephoto lens, the length X and the width Y of the effective area of ​​the imaging chip satisfy: By controlling the size of the effective area of ​​the imaging chip and the focal length of the system, the desired focal length can be achieved, so that the lens has miniaturization, a large target area, a large aperture and good resolution. At the same time, the lens structure is simple, fewer optical elements are required, the lens tolerance sensitivity is low, the lens is easy to process, and the lens is easy to assemble. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the utility model and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 The optical structure diagram of the novel structure telephoto lens according to Example 1 of the present application is shown;

[0018] Figures 2 to 5 The light aberration diagram, distortion diagram, relative illumination and Y field angle diagram and MTF curve diagram of the novel structure telephoto lens of Example 1 are respectively shown;

[0019] Figure 6A schematic diagram of the optical structure of a novel structure telephoto lens according to Example 2 of the present application is shown;

[0020] Figures 7 to 10 The light aberration diagram, distortion diagram, relative illumination and Y field angle diagram and MTF curve diagram of the novel structure telephoto lens of Example 2 are respectively shown;

[0021] Fig.11 The optical structure diagram of the novel structure telephoto lens according to Example 3 of the present application is shown;

[0022] Figures 12 to 15 The light aberration diagram, distortion diagram, relative illumination and Y field angle diagram and MTF curve diagram of the novel structure telephoto lens of Example 3 are respectively shown;

[0023] Fig.16 A schematic diagram of the optical structure of a novel telephoto lens according to Example 4 of the present application is shown;

[0024] Figures 17 to 20 The light aberration diagram, distortion diagram, relative illumination and Y field angle diagram and MTF curve diagram of the novel structure telephoto lens of Example 4 are respectively shown. DETAILED DESCRIPTION

[0025] The aforementioned and other technical contents, features and effects of the utility model will be clearly presented in the following detailed description of the preferred embodiments with reference to the drawings. Through the description of the specific implementation methods, the technical means and effects adopted by the utility model to achieve the intended purpose can be more deeply and specifically understood. However, the attached drawings are only for reference and illustration purposes, and are not used to limit the utility model. Some well-known parts may not be shown. In each of the drawings, the same elements are represented by similar reference numerals. For the sake of clarity, the various parts in the drawings are not necessarily drawn strictly in accordance with the actual proportions.

[0026] It should be understood that the terms "first", "second", "third", "fourth", etc. are only used to distinguish components or circuits with similar properties, rather than indicating or implying relative importance or a specific order. The terms "include", "comprises", or any other variation thereof, are intended to cover non-exclusive inclusion, and may include other elements not explicitly listed in addition to those listed elements.

[0027] In the drawings, the thickness, size and shape of the lenses have been slightly exaggerated for ease of explanation. Specifically, the shapes of the spherical or aspherical surfaces shown in the drawings are shown by way of example. That is, the shapes of the spherical or aspherical surfaces are not limited to the shapes of the spherical or aspherical surfaces shown in the drawings. The drawings are only examples and are not drawn strictly to scale.

[0028] In this article, the paraxial region refers to the region near the optical axis. If the lens surface is convex and the position of the convex surface 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 position of the concave surface 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 object is called the object side of the lens, and the surface of each lens closest to the imaging chip is called the image side of the lens.

[0029] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0030] The features, principles and other aspects of the present application are described in detail below.

[0031] According to the novel structure telephoto lens of the exemplary embodiment of the present application, from the object side to the image side, it includes a lens group, a prism P1, a filter IR and an imaging chip; the lens group includes a plurality of lenses arranged in sequence; the prism P1 includes an incident surface, a first reflection surface, a second reflection surface, a third reflection surface, a fourth reflection surface, a fifth reflection surface and an exit surface, wherein the incident surface, the second reflection surface, the fourth reflection surface and the exit surface are the same surface; the light emitted by the lens group enters the prism P1 from the incident surface, is reflected by the first reflection surface, the second reflection surface, the third reflection surface, the fourth reflection surface and the fifth reflection surface, is emitted by the exit surface, and is projected to the imaging surface IMG of the imaging chip after passing through the filter IR; wherein the system focal length f' of the novel structure telephoto lens, the length X and the width Y of the effective area of ​​the imaging chip satisfy: Thus, the original straight direction of the light can be changed by the prism P1, and the light is emitted after being reflected five times inside the prism P1. The incident surface, the second reflection surface, the fourth reflection surface and the exit surface are the same surface. After the light enters the prism P1 in the thickness direction of the electronic device, it is reflected five times by the prism P1 and changes to bend forward in the length direction or height direction of the body, and is emitted from the prism P1 at the exit surface in the direction of the thickness of the body facing away from the electronic device, that is, the incident surface and the exit surface of the light are on the same side of the prism P1. The light is then projected to the imaging surface IMG of the imaging chip after passing through the filter IR, wherein the back focus optical path of the lens is folded inside the prism P1, so that the light emitted from the prism P1 can reach the imaging chip after a shorter optical path, which correspondingly shortens the back focus length of the lens and realizes the miniaturization of the lens. At the same time, the system focal length f' of the new structure telephoto lens and the length X and width Y of the effective area of ​​the imaging chip are controlled to meet The relationship between the two can prevent the imaging chip from receiving too much light and increasing the aberration and distortion of the image, and also prevent the imaging chip from receiving too little light and causing the image to become dark or blurred, which can be beneficial to achieving the required focal length, so that the lens also has a large target surface, a large aperture and good resolving power. At the same time, the lens structure is simple and requires fewer optical elements, so the lens has low tolerance sensitivity, is easy to process, and is easy to assemble.

[0032] In an exemplary embodiment, according to the novel structure telephoto lens of the present application, the angle α between the incident surface and the first reflection surface satisfies: 21°≤α≤34°. By controlling the angle α between the incident surface and the first reflection surface, the prism P1 can be ensured to have a smaller thickness and length, and the volume of the camera module can be reduced. The smaller the angle α, the shorter the length of the prism P1, and the larger the angle α, the longer the length of the prism P1. If the angle α is less than 21°, it will cause the light to overflow the prism P1 easily, and the light will be randomly reflected inside the prism P1, resulting in serious stray light ghosting inside the module.

[0033] In an exemplary embodiment, according to the novel structure telephoto lens of the present application, the angle α2 between the exit surface and the fifth reflection surface satisfies: 21°≤α2≤34°. By controlling the angle α2 between the exit surface and the fifth reflection surface, the prism P1 can be ensured to have a smaller thickness and length, and the volume of the camera module can be reduced. The smaller the angle α2, the shorter the length of the prism P1, and the larger the angle α2, the longer the length of the prism P1. If the angle α2 is less than 21°, the light will easily overflow the prism P1, and the light will be randomly reflected inside the prism P1, resulting in serious stray light ghosting inside the module.

[0034] In an exemplary embodiment, according to the novel structure telephoto lens of the present application, the prism P1 may be a trapezoidal prism, that is, the incident surface and the third reflection surface are the upper and lower bases of the trapezoidal prism, and the first reflection surface and the fifth reflection surface are the waists of the trapezoidal prism. However, the present invention is not limited thereto, and the prism P1 may also be other structures, such as a quadrilateral in which the incident surface and the third reflection surface are not parallel.

[0035] In an exemplary embodiment, according to the novel structure telephoto lens of the present application, the first reflection surface and the fifth reflection surface are provided with a reflection film. Thus, when the light is reflected by the first reflection surface or the fifth reflection surface, it can be ensured that the light can be completely reflected, reducing the risk of the light being refracted out of the prism P1 when passing through the first reflection surface or the fifth reflection surface.

[0036] In an exemplary embodiment, according to the novel structure telephoto lens of the present application, the system focal length f' of the novel structure telephoto lens and the equivalent thickness H11 of the prism P1 satisfy: 0.5≤H11 / f'≤1.2. By controlling the system focal length f' of the novel structure telephoto lens and the equivalent thickness H11 of the prism P1, the reflection of light in the prism P1 can be controlled to satisfy the optical path of light in the prism P1.

[0037] In an exemplary embodiment, according to the novel structure telephoto lens of the present application, the lens group includes the first lens L1, the second lens L2, the third lens L3 and the fourth lens L4 in sequence, the first lens L1 has positive focal power, the second lens L2 has negative focal power, the third lens L3 has positive focal power, and the fourth lens L4 has negative focal power. Through the combination of the convex or concave surfaces of the first lens L1 to the fourth lens L4, various aberrations can be balanced to obtain clear imaging. Among them, the first lens L1 can play a role in focusing light, and the second lens L2, the third lens L3 and the fourth lens L4 can play a role in aberration correction.

[0038] In an exemplary embodiment, according to the novel structure telephoto lens of the present application, the object side surface of the first lens L1 is a convex surface, and the second lens L2 to the fourth lens L4 are all meniscus lenses, which can produce smaller distortion and phase aberration for imaging.

[0039] In an exemplary embodiment, according to the novel structure telephoto lens of the present application, the sag height SAG7 of the object side surface of the third lens L3 and the sag height SAG8 of the image side surface of the third lens L3 satisfy: 0≤SAG7≤2; 0≤SAG8≤2. Then, by controlling the sag height SAG7 of the object side surface of the third lens L3 and the sag height SAG8 of the image side surface of the third lens L3, it is helpful to meet the focal length index and shrink the light aperture to achieve the ideal image plane height.

[0040] In an exemplary embodiment, according to the novel structure telephoto lens of the present application, the optical focal length φ3 of the third lens L3 satisfies: |φ3|≤0.01. Then, by controlling the optical focal length φ3 of the third lens L3 to be a smaller optical focal length, it is beneficial to reduce aberrations, and the combination with an aspherical surface is beneficial to aberration correction.

[0041] Based on the same utility model concept, according to the electronic device of the exemplary embodiment of the present application, the electronic device includes the above-mentioned novel structure telephoto lens. The electronic device includes but is not limited to a smart phone, a tablet computer, a laptop computer, a pan-tilt camera device, a surveillance camera, and other imaging devices. The implementation of the electronic device can refer to the embodiment of the novel structure telephoto lens, and the repeated parts will not be repeated.

[0042] However, those skilled in the art should understand that, without departing from the technical solution claimed in the present application, the number of lenses constituting the optical imaging lens can be changed to obtain the various results and advantages described in this specification. For example, although four lenses are described as an example in the embodiments, the optical imaging lens is not limited to including four lenses. If necessary, the optical imaging lens may also include other numbers of lenses.

[0043] Specific embodiments of the novel structure telephoto lens applicable to the above-mentioned embodiments are further described below with reference to the accompanying drawings.

[0044] Example 1

[0045] The following reference Figure 1 A new structure telephoto lens according to Example 1 of the present application is described.

[0046] like Figure 1 As shown, the new structure telephoto lens includes an object plane, a lens group, a prism P1, a filter IR and an imaging surface IMG of an imaging chip from the object side to the image side. The lens group includes a first lens L1, a second lens L2, a third lens L3 and a fourth lens L4. The aperture STO can be set between the second lens L2 and the third lens L3. Among them, the angle α between the incident surface of the prism P1 and the first reflection surface is 25°.

[0047] The first lens L1 has positive optical power, and its object side surface is convex, and its image side surface is convex. The second lens L2 has negative optical power, and its object side surface is convex, and its image side surface is concave. The third lens L3 has positive optical power, and its object side surface is convex, and its image side surface is concave. The fourth lens L4 has negative optical power, and its object side surface is convex, and its image side surface is concave. The prism P1 includes an incident surface, a first reflection surface, a second reflection surface, a third reflection surface, a fourth reflection surface, a fifth reflection surface, and an exit surface, wherein the incident surface, the second reflection surface, the fourth reflection surface, and the exit surface are the same surface. The light from the object passes through the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the prism P1, and the filter IR in sequence, and is reflected five times inside the prism P1, and is finally imaged on the imaging surface IMG of the imaging chip.

[0048] Table 1 shows the basic parameters of the novel structure telephoto lens of Example 1, wherein the units of the curvature radius, thickness and sagittal height are all millimeters (mm).

[0049] Table 1:

[0050]

[0051]

[0052] Among them, L1 R1 represents the object side surface of the first lens L1, L1 R2 represents the image side surface of the first lens L1, L2 R1 represents the object side surface of the second lens L2, L2 R2 represents the image side surface of the second lens L2, L3 R1 represents the object side surface of the third lens L3, L3 R2 represents the image side surface of the third lens L3, L4 R1 represents the object side surface of the fourth lens L4, L4 R2 represents the image side surface of the fourth lens L4, IR R1 represents the object side surface of the filter IR, and IR R2 represents the image side surface of the filter IR.

[0053] In Embodiment 1, the object side surface and the image side surface of any lens among the first lens L111 to the fourth lens L414 are both even-order aspherical surfaces, and the surface shape x of each aspherical lens can be defined by, but not limited to, the following aspherical surface formula:

[0054]

[0055] Wherein, x is the distance vector height from the vertex of the aspheric surface when the aspheric surface is at a height of h along the optical axis; c is the paraxial curvature of the aspheric surface, c=1 / R (i.e., the paraxial curvature c is the reciprocal of the curvature radius R in Table 1 above); k is the cone coefficient; Ai is the correction coefficient of the i-th order of the aspheric surface. Table 2 shows the high-order coefficients A2, A4, A6, A8, A10, A12, A14 and A16 that can be used for each aspheric surface in Example 1.

[0056] Table 2:

[0057]

[0058]

[0059] In Example 1, the focal length of the new structure telephoto lens is 33mm, the aperture of the new structure telephoto lens is 4, the imaging circle diameter of the new structure telephoto lens is 9mm, and the angle α between the incident surface and the first reflection surface of the prism P1 is 25°. In the lens group, the vector height SAG7 of the object side of the third lens L3 is 1.23mm, the vector height SAG8 of the image side of the third lens L3 is 1.18mm, and the optical power φ3 of the third lens L3 has the relationship |φ3|=0.004. The system focal length f' of the new structure telephoto lens and the equivalent thickness H11 of the prism P1 are H11 / f'=0.84. The system focal length f' of the new structure telephoto lens and the length X and width Y of the effective area of ​​the imaging chip are

[0060] Figure 2 The light aberration diagram of the novel structure telephoto lens of Example 1 is shown, the graph scale is ±20um, and the aberration correction is good. Figure 3 The distortion diagram of the novel structure telephoto lens of Example 1 is shown, and the distortion is less than 1%, which means the correction is very good. Figure 4 The relative illumination and Y field angle diagram of the novel structure telephoto lens of Example 1 is shown. The relative illumination is greater than 0.9, and the illumination of the picture is uniform. Figure 5 The MTF curve of the novel structure telephoto lens of Example 1 is shown. The MTF curve shows the transmission of image details (i.e., image contrast) of the imaging system at different spatial frequencies. Its OTF modulus is greater than 0.1 at a spatial frequency of 250lp / mm, indicating good resolution. Figures 2 to 5 It can be seen that the new structure telephoto lens provided in Example 1 can achieve good imaging quality.

[0061] Example 2

[0062] The following reference Figure 6 A novel structure telephoto lens according to Embodiment 2 of the present application is described. In this embodiment, for the sake of brevity, some descriptions similar to Embodiment 1 are omitted. Figure 6 A schematic structural diagram of a novel structure telephoto lens according to Example 2 of the present application is shown.

[0063] like Figure 6 As shown, the new structure telephoto lens includes an object plane, a lens group, a prism P1, a filter IR and an imaging surface IMG of an imaging chip from the object side to the image side. The lens group includes a first lens L1, a second lens L2, a third lens L3 and a fourth lens L4. The aperture STO can be set between the second lens L2 and the third lens L3. Among them, the angle α between the incident surface of the prism P1 and the first reflection surface is 25°.

[0064] The first lens L1 has positive optical power, and its object side surface is convex, and its image side surface is convex. The second lens L2 has negative optical power, and its object side surface is convex, and its image side surface is concave. The third lens L3 has positive optical power, and its object side surface is convex, and its image side surface is concave. The fourth lens L4 has negative optical power, and its object side surface is convex, and its image side surface is concave. The prism P1 includes an incident surface, a first reflection surface, a second reflection surface, a third reflection surface, a fourth reflection surface, a fifth reflection surface, and an exit surface, wherein the incident surface, the second reflection surface, the fourth reflection surface, and the exit surface are the same surface. The light from the object passes through the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the prism P1, and the filter IR in sequence, and is reflected five times inside the prism P1, and is finally imaged on the imaging surface IMG of the imaging chip.

[0065] Table 3 shows the basic parameters of the novel structure telephoto lens of Example 2, wherein the units of the curvature radius, thickness and sagittal height are all millimeters (mm).

[0066] Table 3:

[0067]

[0068]

[0069] Table 4 shows the high-order coefficients of each aspherical mirror surface that can be used in Example 2, wherein each aspherical surface shape can be defined by the formula (1) given in the above-mentioned Example 1.

[0070] Table 4:

[0071]

[0072] In Example 2, the focal length of the new structure telephoto lens is 33mm, the aperture of the new structure telephoto lens is 4, the imaging circle diameter of the new structure telephoto lens is 9mm, and the angle α between the incident surface and the first reflection surface of the prism P1 is 25°. In the lens group, the vector height SAG7 of the object side of the third lens L3 is 0.69mm, the vector height SAG8 of the image side of the third lens L3 is 0.68mm, and the optical power φ3 of the third lens L3 has the relationship |φ3|=0.003. The system focal length f' of the new structure telephoto lens and the equivalent thickness H11 of the prism P1 are H11 / f'=0.84. The system focal length f' of the new structure telephoto lens and the length X and width Y of the effective area of ​​the imaging chip are

[0073] Figure 7 The light aberration diagram of the novel structure telephoto lens of Example 2 is shown, the graph scale is ±20um, and the aberration correction is good. Figure 8 The distortion diagram of the novel structure telephoto lens of Example 2 is shown, and the distortion is less than 1%, which means the correction is very good. Fig. 9 The relative illumination and Y field angle diagram of the novel structure telephoto lens of Example 2 is shown. The relative illumination is greater than 0.9, and the illumination of the picture is uniform. Fig.10 The MTF curve of the novel structure telephoto lens of Example 2 is shown. The MTF curve shows the transmission of image details (i.e., image contrast) of the imaging system at different spatial frequencies. Its OTF modulus is greater than 0.1 at a spatial frequency of 250lp / mm, indicating good resolution. Figures 7 to 10 It can be seen that the new structure telephoto lens provided in Example 2 can achieve good imaging quality.

[0074] Example 3

[0075] The following reference Fig.11 A novel structure telephoto lens according to Embodiment 3 of the present application is described. In this embodiment, for the sake of brevity, some descriptions similar to Embodiment 1 are omitted. Fig.11 A schematic structural diagram of a novel structure telephoto lens according to Example 3 of the present application is shown.

[0076] like Fig.11 As shown, the new structure telephoto lens includes an object plane, a lens group, a prism P1, a filter IR and an imaging surface IMG of an imaging chip from the object side to the image side. The lens group includes a first lens L1, a second lens L2, a third lens L3 and a fourth lens L4. The aperture STO can be set between the second lens L2 and the third lens L3. Among them, the angle α between the incident surface of the prism P1 and the first reflection surface is 25°.

[0077] The first lens L1 has positive optical power, and its object side surface is convex, and its image side surface is convex. The second lens L2 has negative optical power, and its object side surface is convex, and its image side surface is concave. The third lens L3 has positive optical power, and its object side surface is convex, and its image side surface is concave. The fourth lens L4 has negative optical power, and its object side surface is convex, and its image side surface is concave. The prism P1 includes an incident surface, a first reflection surface, a second reflection surface, a third reflection surface, a fourth reflection surface, a fifth reflection surface, and an exit surface, wherein the incident surface, the second reflection surface, the fourth reflection surface, and the exit surface are the same surface. The light from the object passes through the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the prism P1, and the filter IR in sequence, and is reflected five times inside the prism P1, and is finally imaged on the imaging surface IMG of the imaging chip.

[0078] Table 5 shows the basic parameters of the novel structure telephoto lens of Example 3, wherein the units of the curvature radius, thickness and sagittal height are all millimeters (mm).

[0079] Table 5:

[0080]

[0081] Table 6 shows the high-order coefficients of each aspherical mirror surface that can be used in Example 3, wherein each aspherical surface shape can be defined by the formula (1) given in the above Example 1.

[0082] Table 6:

[0083]

[0084]

[0085] In Example 3, the focal length of the new structure telephoto lens is 33mm, the aperture of the new structure telephoto lens is 4, the imaging circle diameter of the new structure telephoto lens is 8.8mm, and the angle α between the incident surface and the first reflection surface of the prism P1 is 25°. In the lens group, the vector height SAG7 of the object side of the third lens L3 is 1.16mm, the vector height SAG8 of the image side of the third lens L3 is 0.93mm, and the optical power φ3 of the third lens L3 has the relationship |φ3|=0.001. The system focal length f' of the new structure telephoto lens and the equivalent thickness H11 of the prism P1 are H11 / f'=0.84. The system focal length f' of the new structure telephoto lens and the length X and width Y of the effective area of ​​the imaging chip are

[0086] Fig.12 The light aberration diagram of the novel structure telephoto lens of Example 3 is shown, the graph scale is ±20um, and the aberration correction is good. Fig.13The distortion diagram of the novel structure telephoto lens of Example 3 is shown, and the distortion is less than 1%, which means the correction is very good. Fig.14 The relative illumination and Y field angle diagram of the novel structure telephoto lens of Example 3 is shown. The relative illumination is greater than 0.9, and the illumination of the picture is uniform. Fig.15 The MTF curve of the novel structure telephoto lens of Example 3 is shown. The MTF curve shows the transmission of image details (i.e., image contrast) of the imaging system at different spatial frequencies. Its OTF modulus is greater than 0.1 at a spatial frequency of 250lp / mm, indicating good resolution. Figures 12 to 15 It can be seen that the new structure telephoto lens provided in Example 3 can achieve good imaging quality.

[0087] Example 4

[0088] The following reference Fig.16 A novel structure telephoto lens according to Embodiment 4 of the present application is described. In this embodiment, for the sake of brevity, some descriptions similar to Embodiment 1 are omitted. Fig.16 A schematic structural diagram of a novel structure telephoto lens according to Example 4 of the present application is shown.

[0089] like Fig.16 As shown, the new structure telephoto lens includes an object plane, a lens group, a prism P1, a filter IR and an imaging surface IMG of an imaging chip from the object side to the image side. The lens group includes a first lens L1, a second lens L2, a third lens L3 and a fourth lens L4. The aperture STO can be set between the second lens L2 and the third lens L3. Among them, the angle α between the incident surface of the prism P1 and the first reflection surface is 23°.

[0090] The first lens L1 has positive optical power, and its object side surface is convex, and its image side surface is concave. The second lens L2 has negative optical power, and its object side surface is convex, and its image side surface is concave. The third lens L3 has positive optical power, and its object side surface is convex, and its image side surface is concave. The fourth lens L4 has negative optical power, and its object side surface is convex, and its image side surface is concave. The prism P1 includes an incident surface, a first reflection surface, a second reflection surface, a third reflection surface, a fourth reflection surface, a fifth reflection surface, and an exit surface, wherein the incident surface, the second reflection surface, the fourth reflection surface, and the exit surface are the same surface. The light from the object passes through the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the prism P1, and the filter IR in sequence, and is reflected five times inside the prism P1, and is finally imaged on the imaging surface IMG of the imaging chip.

[0091] Table 7 shows the basic parameters of the novel structure telephoto lens of Example 4, wherein the units of the curvature radius, thickness and sagittal height are all millimeters (mm).

[0092] Table 7:

[0093]

[0094] Table 8 shows the high-order coefficients of each aspherical mirror surface that can be used in Example 4, wherein each aspherical surface shape can be defined by the formula (1) given in the above-mentioned Example 1.

[0095] Table 8:

[0096]

[0097] In Example 4, the focal length of the new structure telephoto lens is 27mm, the aperture of the new structure telephoto lens is 4, the imaging circle diameter of the new structure telephoto lens is 6mm, and the angle α between the incident surface and the first reflection surface of the prism P1 is 23°. In the lens group, the vector height SAG7 of the object side of the third lens L3 is 0.96mm, the vector height SAG8 of the image side of the third lens L3 is 0.75mm, and the optical power φ3 of the third lens L3 has the relationship |φ3|=0.007. The system focal length f' of the new structure telephoto lens and the equivalent thickness H11 of the prism P1 are H11 / f'=0.96. The system focal length f' of the new structure telephoto lens and the length X and width Y of the effective area of ​​the imaging chip are

[0098] Fig.17 The light aberration diagram of the novel structure telephoto lens of Example 4 is shown, the graph scale is ±20um, and the aberration correction is good. Fig.18 The distortion diagram of the novel structure telephoto lens of Example 4 is shown, and the distortion is less than 1%, which is very well corrected. Fig.19 The relative illumination and Y field angle diagram of the novel structure telephoto lens of Example 4 is shown. The relative illumination is greater than 0.9, and the illumination of the picture is uniform. Fig. 20 The MTF curve of the novel structure telephoto lens of Example 4 is shown. The MTF curve shows the transmission of image details (i.e., image contrast) of the imaging system at different spatial frequencies. Its OTF modulus is greater than 0.05 at a spatial frequency of 250lp / mm, indicating good resolution. Figures 17 to 20 It can be seen that the new structure telephoto lens provided in Example 4 can achieve good imaging quality.

[0099] In summary, Example 1, Example 2, Example 3 and Example 4 respectively satisfy the relationship shown in Table 9.

[0100] Table 9:

[0101]

[0102] The above description is only a preferred embodiment of the present application and an explanation of the technical principles used. Those skilled in the art should understand that the scope of the utility model involved in the present application is not limited to the technical solution formed by a specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the concept of the utility model. For example, the above features are replaced with the technical features with similar functions disclosed in the present application (but not limited to) by each other to form a technical solution.

Claims

1. A new type of telephoto lens, characterized in that: From the object side to the image side, it includes a lens group, a prism, a filter and an imaging chip; The lens group includes a plurality of lenses arranged in sequence; The prism comprises an incident surface, a first reflecting surface, a second reflecting surface, a third reflecting surface, a fourth reflecting surface, a fifth reflecting surface and an exiting surface, wherein the incident surface, the second reflecting surface, the fourth reflecting surface and the exiting surface are the same surface; The light emitted by the lens group enters the prism from the incident surface, is reflected by the first reflection surface, the second reflection surface, the third reflection surface, the fourth reflection surface and the fifth reflection surface, is emitted from the exit surface, and is projected onto the imaging surface of the imaging chip after passing through the filter; The system focal length f' of the novel structure telephoto lens and the length X and width Y of the effective area of ​​the imaging chip satisfy:

2. The novel structure telephoto lens according to claim 1, characterized in that: An included angle α between the incident surface and the first reflecting surface satisfies: 21°≤α≤34°.

3. The novel structure telephoto lens according to claim 1, characterized in that: The prism is a trapezoidal prism.

4. The novel structure telephoto lens according to claim 1, characterized in that: The first reflecting surface and the fifth reflecting surface are provided with reflecting films.

5. The novel structure telephoto lens according to claim 1, characterized in that: The system focal length f' of the novel structure telephoto lens and the equivalent thickness H11 of the prism satisfy: 0.5≤H11 / f'≤1.

2.

6. The novel structure telephoto lens according to claim 1, characterized in that: The lens group includes a first lens, a second lens, a third lens and a fourth lens in sequence, the first lens has positive optical power, the second lens has negative optical power, the third lens has positive optical power, and the fourth lens has negative optical power.

7. The novel structure telephoto lens according to claim 6, characterized in that: The object side surface of the first lens is a convex surface, and the second lens to the fourth lens are all meniscus lenses.

8. The novel structure telephoto lens according to claim 6, characterized in that: The sag height SAG7 of the object side surface of the third lens and the sag height SAG8 of the image side surface of the third lens satisfy: 0≤SAG7≤2; 0≤SAG8≤2.

9. The novel structure telephoto lens according to claim 6, characterized in that: The optical power φ3 of the third lens satisfies: |φ3|≤0.

01.

10. An electronic device, characterized in that: A telephoto lens having a novel structure as claimed in any one of claims 1 to 9.

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