Long-focus lens, long-focus camera module and electronic device

Abstract

The application discloses a long-focus lens, a long-focus camera module and an electronic device. The long-focus lens comprises, in order from the object side to the image side, a first lens with positive refractive power, a second lens with negative refractive power, a third lens with refractive power and a fourth lens with refractive power. The object side surface of the first lens is a convex surface. The object side surface and the image side surface of the second lens are both concave surfaces. The object side surface of the third lens is a concave surface. The long-focus lens satisfies the following relationship: TTL / f<0.96; wherein TTL is the distance from the object side surface of the first lens to the imaging surface of the long-focus lens on the optical axis, and f is the effective focal length of the long-focus lens. The long-focus lens has a short TTL through reasonable TTL configuration, thereby shortening the length of the lens barrel of the long-focus lens.

Description

Technical Field

[0001] The present invention relates to optical imaging technology, and in particular to a telephoto lens, a telephoto camera module and an electronic device. Background Art

[0002] A telephoto lens has a long focal length and a narrow angle of view, resulting in a larger image on film. Therefore, it produces a larger image than a standard lens at the same distance, making it suitable for photographing distant subjects. Because its depth of field is narrower than a standard lens, it can more effectively blur the background and highlight the in-focus subject. Furthermore, since the subject is generally farther away from the camera, perspective distortion is minimized, resulting in more vivid portraits. Therefore, telephoto lenses are often called portrait lenses. However, telephoto lenses generally have longer barrels. Summary of the Invention

[0003] In view of this, embodiments of the present invention provide a telephoto lens, a telephoto camera module, and an electronic device.

[0004] A telephoto lens according to an embodiment of the present invention includes, from the object side to the image side, a first lens having positive refractive power, a second lens having negative refractive power, a third lens having refractive power, and a fourth lens having refractive power. The object-side surface of the first lens is convex. Both the object-side and image-side surfaces of the second lens are concave. The object-side surface of the third lens is concave. The telephoto lens satisfies the following relationship: TTL / f<0.96; where TTL is the distance on the optical axis from the object-side surface of the first lens to the imaging plane of the telephoto lens, and f is the effective focal length of the telephoto lens.

[0005] The telephoto lens of the embodiment of the present invention has a shorter TTL through reasonable TTL configuration, thereby shortening the lens barrel length of the telephoto lens.

[0006] In some embodiments, the telephoto lens satisfies the following relationship: f1 / f<0.51; where f1 is the focal length of the first lens.

[0007] When the above relationship is satisfied, the first lens has a suitable focal length, which is conducive to achieving a balance between expanding the field of view of the telephoto lens and shortening the total optical length of the telephoto lens, and the depth of field is large, making it easier to focus.

[0008] In some embodiments, the telephoto lens satisfies the following relationship: SD / TTL<0.75; wherein SD is the distance from the object side surface of the first lens to the image side surface of the fourth lens on the optical axis.

[0009] When the above relationship is satisfied, the length of the device (lens barrel) for fixing all lenses can be shortened, which is beneficial to production and improves yield.

[0010] In some embodiments, the telephoto lens satisfies the following relationship: OA / IMA < 0.4; where OA is the maximum effective radius of the lens among the first lens to the fourth lens, and IMA is the length of the diagonal of the photosensitive element on the imaging surface.

[0011] When the above relationship is satisfied, it is beneficial to the miniaturization of the telephoto lens and meets the requirements of high pixel.

[0012] In some embodiments, the telephoto lens satisfies the following relationship: -5 < R4 / R5 < 0; where R4 is the curvature radius of the image side of the second lens, and R5 is the curvature radius of the object side of the third lens.

[0013] When the above relationship is satisfied, the shapes of the second lens and the third lens can be well coordinated, which is not only beneficial to the processing and manufacturing of the second lens and the third lens and the assembly of the telephoto lens, improving the product yield, but also beneficial to correcting aberrations.

[0014] In some embodiments, the telephoto lens further includes an aperture, and the telephoto lens satisfies the following relationship: 0.2 < SL / TTL < 0.9; where SL is the distance from the aperture to the imaging surface on the optical axis.

[0015] When the above relationship is satisfied, the exit pupil of the telephoto lens can be far from the imaging surface, so the light will enter the photosensitive element in a way close to perpendicular incidence, which is beneficial to achieving the telecentric characteristic on the image side, thereby improving the photosensitive sensitivity of the photosensitive element and reducing the possibility of vignetting in the system.

[0016] In some embodiments, the telephoto lens satisfies the following relationship: 0.5 < CT1 / D < 1; where CT1 is the central thickness of the first lens, and D is the Y radius of the first lens.

[0017] When the above relationship is satisfied, the first lens has a more appropriate size, which is beneficial to improving the imaging quality of the telephoto lens and shortening the height of the telephoto lens, and can also reduce the molding difficulty, improve the yield, and reduce the cost.

[0018] In some embodiments, the first lens to the fourth lens are plastic lenses or glass lenses, and the telephoto lens satisfies the following relationship: 0 ≤ N ≤ 4; where N is the number of glass lenses among the first lens to the fourth lens.

[0019] In this way, by reasonably configuring the materials of the lenses, the telephoto lens is beneficial to correcting aberrations and solving the problem of temperature drift. In addition, the four lenses are lighter in weight, and through reasonable power distribution, the production cost can be reduced and satisfactory optical performance can be achieved.

[0020] In some embodiments, at least one surface of the first to fourth lenses is aspherical.

[0021] In this way, the telephoto lens can reduce the number of lenses by adjusting the curvature radius and aspheric coefficient of the lens surface, effectively shortening the total length of the telephoto lens. The use of diversified surface shapes can effectively correct the aberration of the telephoto lens and improve the imaging quality.

[0022] The telephoto camera module according to an embodiment of the present invention comprises a photosensitive element and a telephoto lens according to any one of the above embodiments, wherein the photosensitive element is arranged on the image side of the telephoto lens.

[0023] The telephoto camera module according to the embodiment of the present invention has a shorter TTL due to a reasonable TTL configuration, thereby shortening the lens barrel length of the telephoto lens.

[0024] An electronic device according to an embodiment of the present invention includes a housing and the telephoto camera module according to the above embodiment, wherein the telephoto camera module is mounted on the housing.

[0025] The electronic device according to the embodiment of the present invention has a shorter TTL through reasonable TTL configuration, thereby shortening the barrel length of the telephoto lens.

[0026] In some embodiments, the electronic device further includes a wide-angle camera module, wherein the wide-angle camera is mounted on the housing, and the electronic device is capable of acquiring telephoto images through the telephoto camera module and wide-angle images through the wide-angle camera module.

[0027] In this way, the electronic device can be used in conjunction with a wide-angle camera module with a short system effective focal length and a wider viewing angle installed on the housing. When capturing images, the electronic device will allow the user to select between different camera functions (telephoto or wide angle), and can also be used in conjunction with an algorithm to achieve the effect of optical zoom, thereby improving the imaging effect.

[0028] Additional aspects and advantages of the embodiments of the present invention will be given in part in the following description and in part will be obvious from the following description or learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments with reference to the following drawings, in which:

[0030] Figure 1 is a schematic structural diagram of a telephoto lens according to a first embodiment of the present invention;

[0031] Figure 2 is a longitudinal aberration diagram of the telephoto lens in the first embodiment (mm);

[0032] Figure 3 is the field curvature diagram (mm) of the telephoto lens in the first embodiment;

[0033] Figure 4 is a distortion diagram (%) of the telephoto lens in the first embodiment;

[0034] Figure 5 is a schematic structural diagram of a telephoto lens according to a second embodiment of the present invention;

[0035] Figure 6 is a longitudinal aberration diagram of the telephoto lens in the second embodiment (mm);

[0036] Figure 7 is the field curvature diagram (mm) of the telephoto lens in the second embodiment;

[0037] Figure 8 is a distortion diagram (%) of the telephoto lens in the second embodiment;

[0038] Figure 9 is a schematic structural diagram of a telephoto lens according to a third embodiment of the present invention;

[0039] Figure 10 is a longitudinal aberration diagram of the telephoto lens in the third embodiment (mm);

[0040] Figure 11 is the field curvature diagram (mm) of the telephoto lens in the third embodiment;

[0041] Figure 12 is a distortion diagram (%) of the telephoto lens in the third embodiment;

[0042] Figure 13 is a schematic structural diagram of a telephoto lens according to a fourth embodiment of the present invention;

[0043] Figure 14 is a longitudinal aberration diagram of the telephoto lens in the fourth embodiment (mm);

[0044] Figure 15 is a graph of field curvature of the telephoto lens in the fourth embodiment (mm);

[0045] Figure 16 is a diagram showing the distortion (%) of the telephoto lens in the fourth embodiment;

[0046] Figure 17 is a schematic structural diagram of a telephoto camera module according to an embodiment of the present invention;

[0047] Figure 18 is a schematic structural diagram of an electronic device according to an embodiment of the present invention; and

[0048] Figure 19 It is a schematic structural diagram of an electronic device according to another embodiment of the present invention. DETAILED DESCRIPTION

[0049] The embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and are not to be construed as limiting the present invention.

[0050] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like, indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the said features. In the description of the present invention, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0051] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; mechanical connections, electrical connections, or mutual communication; direct connections or indirect connections through an intermediate medium; and internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0052] The disclosure below provides many different embodiments or examples for realizing different structures of the present invention. In order to simplify the disclosure of the present invention, the components and settings of specific examples are described below. Of course, they are merely examples and are not intended to limit the present invention. In addition, the present invention may repeat reference numbers and / or reference letters in different examples. Such repetition is for the purpose of simplicity and clarity and does not in itself indicate the relationship between the various embodiments and / or settings discussed. In addition, the present invention provides examples of various specific processes and materials, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0053] Please also refer to Figure 1 、 Figure 5 、 Figure 9 and Figure 13 The telephoto lens 10 of the embodiment of the present invention includes, from the object side to the image side, a first lens L1 with positive refractive power, a second lens L2 with negative refractive power, a third lens L3 with refractive power, and a fourth lens L4 with refractive power.

[0054] The first lens L1 has an object-side surface S1 and an image-side surface S2, with the object-side surface S1 of the first lens L1 being convex. The second lens L2 has an object-side surface S3 and an image-side surface S4, with both the object-side surface S3 and the image-side surface S4 of the second lens L2 being concave. The third lens L3 has an object-side surface S5 and an image-side surface S6, with the object-side surface S5 of the third lens L3 being concave. The fourth lens L4 has an object-side surface S7 and an image-side surface S8.

[0055] The telephoto lens 10 satisfies the following relationship: TTL / f<0.96; wherein TTL is the distance from the object side S1 of the first lens L1 to the imaging surface S11 of the telephoto lens 10 (i.e. Figure 17 where TTL / f is the distance between the photosensitive element 20 and the telephoto lens 10 on the optical axis, and f is the effective focal length of the telephoto lens 10. In other words, TTL / f can be any value less than 0.96, for example, 0.1, 0.15, 0.754, 0.825, 0.917, 0.937, 0.941, 0.95, 0.956, 0.958, 0.959, etc.

[0056] When the telephoto lens 10 is used for imaging, light emitted or reflected by the object OBJ enters the telephoto lens 10 from the object side, and passes through the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, and the infrared filter L5 having an object side S9 and an image side surface S10, and finally converges on the imaging surface S11.

[0057] The telephoto lens 10 according to the embodiment of the present invention has a shorter TTL due to a reasonable TTL configuration, thereby shortening the lens barrel length of the telephoto lens 10 .

[0058] In some embodiments, the telephoto lens 10 further includes a stop STO. The stop STO may be an aperture stop or a field stop. The embodiments of the present invention are described by taking the stop STO as an example. The stop STO may be provided on the surface of any lens, or before the first lens L1, or between any two lenses, or between the fourth lens L4 and the infrared filter L5. For example, in the first embodiment, the second embodiment, and the fourth embodiment, as shown in FIG. Figure 1 、 Figure 5 、 Figure 13 As shown, the aperture STO is provided between the first lens L1 and the second lens L2; ​​in the third embodiment, as shown Figure 9 As shown, the aperture stop STO is arranged between the second lens L2 and the third lens L3.

[0059] In some embodiments, the telephoto lens 10 satisfies the following relationship: f1 / f<0.51, where f1 is the focal length of the first lens element L1. In other words, f1 / f can be any value less than 0.51, such as -100, -50, -40, -30, 0.44, 0.457, 0.5, 0.504, 0.505, 0.508, and so on.

[0060] When the above relationship is satisfied, the first lens L1 has a suitable focal length, which is conducive to achieving a balance between expanding the field of view of the telephoto lens 10 and shortening the total optical length of the telephoto lens 10, and has a larger depth of field, making it easier to focus.

[0061] In some embodiments, the telephoto lens 10 satisfies the following relationship: SD / TTL<0.75, where SD is the distance along the optical axis from the object-side surface S1 of the first lens element L1 to the image-side surface S8 of the fourth lens element L4. In other words, SD / TTL can be any value less than 0.75, such as 0.1, 0.152, 0.2, 0.242, 0.265, 0.659, 0.65, 0.7, 0.717, 0.74, and so on.

[0062] When the above relationship is satisfied, the length of the device (lens barrel) for fixing all lenses can be shortened, which is beneficial to production and improves yield.

[0063] In some embodiments, the telephoto lens 10 satisfies the following relationship: OA / IMA<0.4; wherein OA is the maximum effective radius of the lenses from the first lens L1 to the fourth lens L4 (i.e., the effective radius of the lens with the largest effective radius from the first lens L1 to the fourth lens L4 is taken as the maximum effective radius), and IMA is Figure 17 The photosensitive element 20 is shown on the imaging surface S11 (ie Figure 17 In other words, OA / IMA can be any value less than 0.4, for example, 0.112, 0.155, 0.212, 0.243, 0.265, 0.285, 0.34, 0.343, 0.355, 0.365, 0.386, 0.392, etc.

[0064] When the above relationship is satisfied, it is beneficial to miniaturize the telephoto lens 10 and meet the high pixel requirement.

[0065] In some embodiments, the telephoto lens 10 satisfies the following relational expression: -5 < R4 / R5 < 0; where R4 is the radius of curvature of the image side S4 of the second lens L2, and R5 is the radius of curvature of the object side S5 of the third lens L3. That is to say, R4 / R5 can be any value within the interval (-5, 0). For example, this value can be -4.81, -4.58, -4, -3.52, -3, -0.6, -0.4, -0.221, -0.105, -0.081, -0.018, -0.01, etc.

[0066] When the above relational expression is satisfied, the shapes of the second lens L2 and the third lens L3 can be well coordinated, which is not only beneficial to the processing and manufacturing of the second lens L2 and the third lens L3 and the assembly of the telephoto lens 10, improving the product yield, but also beneficial to correcting aberrations.

[0067] In some embodiments, the telephoto lens 10 satisfies the following relational expression: 0.2 < SL / TTL < 0.9; where SL is the distance on the optical axis from the aperture STO to the imaging surface S11 (i.e., Figure 17 the photosensitive element 20 shown).

[0068] That is to say, SL / TTL can be any value within the interval (0.2, 0.9). For example, this value can be 0.25, 0.28, 0.82, 0.84, 0.85, 0.89, etc.

[0069] When the above relational expression is satisfied, the exit pupil of the telephoto lens 10 can be far from the imaging surface S11. Therefore, light rays will be incident on the Figure 17 photosensitive element 20 shown in a manner close to perpendicular incidence, which is beneficial to achieving the telecentric characteristic on the image side, thereby Figure 17 increasing the photosensitive sensitivity of the photosensitive element 20 shown and reducing the possibility of vignetting of the telephoto lens 10.

[0070] In some embodiments, the telephoto lens 10 satisfies the following relational expression: 0.5 < CT1 / D < 1; where CT1 is the central thickness of the first lens L1, and D is the Y radius of the first lens L1. That is to say, CT1 / D can be any value within the interval (0.5, 1). For example, this value can be 0.51, 0.55, 0.6, 0.65, 0.82, 0.85, 0.89, 0.9, 0.95, 0.98, etc.

[0071] When the above relational expression is satisfied, the first lens L1 has a more appropriate size, which is beneficial to improving the imaging quality of the telephoto lens 10 and shortening the height of the telephoto lens 10. It can also reduce the molding difficulty, improve the yield, and reduce the cost.

[0072] In certain embodiments, the first through fourth lenses L1 through L4 are plastic lenses or glass lenses, and the telephoto lens 10 satisfies the following relationship: 0 ≤ N ≤ 4, where N is the number of glass lenses used in the first through fourth lenses L1 through L4. In other words, N can be any integer between [0, 4], for example, 0, 1, 2, 3, or 4. For example, in the first embodiment, the first through fourth lenses L1 through L4 are all plastic lenses; in the second embodiment, the first and second lenses L1 and L2 are glass lenses, and the third and fourth lenses L3 and L4 are plastic lenses; in the third and fourth embodiments, the first and third lenses L1 and L3 are glass lenses, and the second and fourth lenses L2 and L4 are plastic lenses.

[0073] Thus, by rationally configuring lens materials, telephoto lens 10 achieves ultra-thinness and low cost while correcting for aberrations and addressing thermal drift. Furthermore, the use of four lens elements results in a lightweight design. By rationally combining optical powers, production costs can be reduced while still achieving satisfactory optical performance.

[0074] In some embodiments, at least one surface of at least one lens in the telephoto lens 10 is aspherical. For example, in the first embodiment, the object-side surface and the image-side surface of the first lens L1, the third lens L3, and the fourth lens L4 are all aspherical surfaces.

[0075] In some embodiments, the first lens L1, the second lens L2, the third lens L3, and the fourth lens L4 are all aspherical lenses. The shape of the aspherical surface is determined by the following formula: Where Z is the longitudinal distance from any point on the aspheric surface to the vertex of the surface, r is the distance from any point on the aspheric surface to the optical axis, c is the vertex curvature (the inverse of the curvature radius), k is the cone constant, and Ai is the correction coefficient of the i-th order aspheric surface.

[0076] In this way, the telephoto lens 10 can effectively shorten the total length of the telephoto lens 10 by adjusting the curvature radius and aspheric coefficient of each lens surface, and can effectively correct aberrations and improve imaging quality.

[0077] First embodiment:

[0078] See also Figures 1 to 4 In the infrared lens 10 of the first embodiment, from the object side to the image side, it includes a first lens L1, a second lens L2, a third lens L3, a fourth lens L4 and an infrared filter L5.

[0079] The first lens L1 has positive refractive power and is made of plastic. Its object-side surface S1 is convex, and its image-side surface S2 is convex at the optical axis and flat at the circumference, and both are aspherical. The second lens L2 has negative refractive power and is made of plastic. Its object-side surface S3 is concave at the optical axis and flat at the circumference, and its image-side surface S4 is concave. The object-side surface S3 is spherical, and the image-side surface S4 is aspherical. The third lens L3 has positive refractive power and is made of plastic. Its object-side surface S5 is concave, and the image-side surface S6 is convex, and both are aspherical. The fourth lens L4 has negative refractive power and is made of plastic. Its object-side surface S7 is concave, and the image-side surface S8 is convex, and both are aspherical.

[0080] The aperture STO is provided between the first lens L1 and the second lens L2. The aperture number FNO of the infrared lens 10 is 2.6.

[0081] The infrared filter L5 is made of glass and is disposed between the fourth lens L4 and the imaging surface S11 without affecting the focal length of the infrared lens 10 .

[0082] In the first embodiment, the effective focal length of the infrared lens 10 is f=9.6, the aperture number of the infrared lens 10 is FNO=2.6, and the field of view of the infrared lens 10 is FOV=31 degrees. The infrared lens 10 meets the following conditions: TTL / f=0.958; f1 / f=0.457; SD / TTL=0.597; OA / IMA=0.343; R4 / R5=-0.81; SL / TTL=0.81; and CT1 / D=0.9.

[0083] The telephoto lens 10 meets the conditions in the following table:

[0084] Table 1

[0085]

[0086]

[0087] Table 2

[0088]

[0089] Second embodiment

[0090] See also Figures 5 to 8 In the infrared lens 10 of the second embodiment, from the object side to the image side, it includes a first lens L1, a second lens L2, a third lens L3, a fourth lens L4 and an infrared filter L5.

[0091] The first lens L1 has positive refractive power and is made of glass. Its object-side surface S1 is convex, and its image-side surface S2 is convex, both of which are aspherical. The second lens L2 has negative refractive power and is made of glass. Its object-side surface S3 is concave at the optical axis and flat at the circumference. Its image-side surface S4 is concave. The object-side surface S3 is spherical, and the image-side surface S4 is aspherical. The third lens L3 has positive refractive power and is made of plastic. Its object-side surface S5 is concave, and the image-side surface S6 is convex, both of which are aspherical. The fourth lens L4 has negative refractive power and is made of plastic. Its object-side surface S7 is concave, and the image-side surface S8 is concave at the optical axis and convex at the circumference. Both of which are aspherical.

[0092] The aperture STO is provided between the first lens L1 and the second lens L2. The aperture number FNO of the infrared lens 10 is 2.6.

[0093] The infrared filter L5 is made of glass and is disposed between the fourth lens L4 and the imaging surface S11 without affecting the focal length of the infrared lens 10 .

[0094] The telephoto lens 10 meets the conditions in the following table:

[0095] Table 3

[0096]

[0097] Table 4

[0098]

[0099]

[0100] According to Table 3 and Table 4, the following data can be obtained:

[0101] f(mm) 9.8 SD / TTL 0.717 FNO 2.6 OA / IMA 0.343 FOV(degree) 30.6 R4 / R5 -1.07 TTL / f 0.937 SL / TTL 0.84 f1 / f 0.416 CT1 / D 0.76

[0102] Third embodiment

[0103] See also Figures 9 to 12 In the infrared lens 10 of the third embodiment, from the object side to the image side, it includes a first lens L1, a second lens L2, a third lens L3, a fourth lens L4 and an infrared filter L5.

[0104] The first lens L1 has positive refractive power and is made of glass. Its object-side surface S1 is convex, and its image-side surface S2 is convex, both of which are aspherical. The second lens L2 has negative refractive power and is made of plastic. Its object-side surface S3 is concave, and its image-side surface S4 is concave at the optical axis and flat at the circumference. The object-side surface S3 is spherical, and the image-side surface S4 is aspherical. The third lens L3 has negative refractive power and is made of glass. Its object-side surface S5 is concave, and its image-side surface S6 is concave at the optical axis and convex at the circumference. Both of which are aspherical. The fourth lens L4 has positive refractive power and is made of plastic. Its object-side surface S7 is convex, and its image-side surface S8 is convex, both of which are aspherical.

[0105] The aperture STO is provided between the second lens L2 and the third lens L3. The aperture number FNO of the infrared lens 10 is 2.6.

[0106] The infrared filter L5 is made of glass and is disposed between the fourth lens L4 and the imaging surface S11 without affecting the focal length of the infrared lens 10 .

[0107] The telephoto lens 10 meets the conditions in the following table:

[0108] Table 5

[0109]

[0110]

[0111] Table 6

[0112]

[0113] According to Table 5 and Table 6, the following data can be obtained:

[0114] f(mm) 9.77 SD / TTL 0.659 FNO 2.6 OA / IMA 0.343 FOV(degree) 30.6 R4 / R5 -4.81 TTL / f 0.941 SL / TTL 0.296 f1 / f 0.421 CT1 / D 0.74

[0115] Fourth embodiment

[0116] See also Figures 13 to 16 In the infrared lens 10 of the fourth embodiment, from the object side to the image side, it includes a first lens L1, a second lens L2, a third lens L3, a fourth lens L4 and an infrared filter L5.

[0117] The first lens L1 has positive refractive power and is made of glass. Its object-side surface S1 is convex, and its image-side surface S2 is concave at the optical axis and flat at the circumference, and both are aspherical. The second lens L2 has negative refractive power and is made of plastic. Its object-side surface S3 is concave, and its image-side surface S4 is concave, and both are aspherical. The third lens L3 has positive refractive power and is made of glass. Its object-side surface S5 is concave at the optical axis and convex at the circumference, and its image-side surface S6 is convex, and both are aspherical. The fourth lens L4 has negative refractive power and is made of plastic. Its object-side surface S7 is concave, and its image-side surface S8 is convex, and both are aspherical.

[0118] The aperture STO is provided between the first lens L1 and the second lens L2. The aperture number FNO of the infrared lens 10 is 2.6.

[0119] The infrared filter L5 is made of glass and is disposed between the fourth lens L4 and the imaging surface S11 without affecting the focal length of the infrared lens 10 .

[0120] The telephoto lens 10 meets the conditions in the following table:

[0121] Table 7

[0122]

[0123] Table 8

[0124]

[0125]

[0126] According to Table 7 and Table 8, the following data can be obtained:

[0127] f(mm) 9.6 SD / TTL 0.643 FNO 2.6 OA / IMA 0.343 FOV(degree) 31 R4 / R5 -0.018 TTL / f 0.956 SL / TTL 0.8 f1 / f 0.504 CT1 / D 0.82

[0128] See also Figure 17 The telephoto camera module 100 according to the embodiment of the present invention includes a photosensitive element 20 and the telephoto lens 10 according to any of the above embodiments. The photosensitive element 20 is disposed on the image side of the telephoto lens 10.

[0129] The photosensitive element 20 may be a complementary metal oxide semiconductor (CMOS) photosensitive element or a charge-coupled device (CCD) photosensitive element.

[0130] See also Figure 18 and Figure 19The electronic device 1000 according to the embodiment of the present invention includes a housing 400 and the telephoto camera module 100 according to the above embodiment. The telephoto camera module 100 is mounted on the housing 400. The housing 400 can protect the telephoto camera module.

[0131] In some embodiments, the electronic device 1000 further includes a wide-angle camera module 200 , which is mounted on the housing 400 . The electronic device 100 can obtain telephoto images through the telephoto camera module 100 and wide-angle images through the wide-angle camera module 200 .

[0132] In this way, the electronic device 1000 can be used in conjunction with the wide-angle camera module 200 with a short system effective focal length and a wider viewing angle installed on the housing 400. When capturing images, the electronic device will allow the user to choose between different camera functions (telephoto or wide angle), and can also be used in conjunction with an algorithm to achieve the effect of optical zoom, thereby improving the imaging effect.

[0133] The electronic device 1000 of the embodiment of the present invention includes but is not limited to a smart phone (such as Figure 18 shown), mobile phones, personal digital assistants (PDAs), game consoles, personal computers (PCs), cameras, smart watches, tablet computers ( Figure 19 information terminal devices such as those shown in the figure) or household appliances with camera functions.

[0134] Throughout this specification, reference to terms such as "certain embodiments," "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with the embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the exemplary descriptions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0135] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0136] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are exemplary and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention. The scope of the present invention is defined by the claims and their equivalents.

Claims

1. A telephoto lens, characterized in that: The number of lenses with refractive power is four, and the telephoto lens includes, from the object side to the image side, the following: a first lens having positive refractive power, wherein the object-side surface of the first lens is convex; a second lens having negative refractive power, wherein both the object-side surface and the image-side surface of the second lens are concave; a third lens having refractive power, wherein the object-side surface of the third lens is concave; and a fourth lens having refractive power; The telephoto lens satisfies the following relationship: TTL / f<0.96; OA / IMA<0.4; Wherein, TTL is the distance from the object side of the first lens to the imaging plane of the telephoto lens on the optical axis, f is the effective focal length of the telephoto lens, OA is the maximum effective radius of the lens from the first lens to the fourth lens, and IMA is the diagonal length of the photosensitive element on the imaging plane.

2. The telephoto lens according to claim 1, wherein: The telephoto lens satisfies the following relationship: f1 / f<0.51; Wherein, f1 is the focal length of the first lens.

3. The telephoto lens according to claim 1, wherein: The telephoto lens satisfies the following relationship: 0.597≤SD / TTL<0.717; Wherein, SD is the distance on the optical axis from the object side surface of the first lens to the image side surface of the fourth lens.

4. The telephoto lens according to claim 1, wherein: The telephoto lens satisfies the following relationship: -5 <R4 / R5<0; Wherein, R4 is the curvature radius of the image side surface of the second lens, and R5 is the curvature radius of the object side surface of the third lens.

5. The telephoto lens according to claim 1, wherein: The telephoto lens further includes an aperture, and the telephoto lens satisfies the following relationship: 0.2 <SL / TTL<0.9; Wherein, SL is the distance from the aperture to the imaging surface on the optical axis.

6. The telephoto lens according to claim 1, wherein: The telephoto lens satisfies the following relationship: 0.5 <CT1 / D<1; Wherein, CT1 is the center thickness of the first lens, and D is the Y radius of the first lens.

7. The telephoto lens according to claim 1, wherein: The first to fourth lenses are plastic lenses or glass lenses, and the telephoto lens satisfies the following relationship: 0≤N≤4； Wherein, N is the number of glass lenses used in the first lens to the fourth lens.

8. The telephoto lens according to claim 1, wherein: At least one surface of the first to fourth lenses is aspherical.

9. A telephoto camera module, characterized in that: The telephoto camera module includes: The telephoto lens according to any one of claims 1 to 8; and A photosensitive element is arranged on the image side of the telephoto lens.

10. An electronic device, characterized in that: The electronic device comprises: housing; and The telephoto camera module according to claim 9, wherein the telephoto camera module is mounted on the housing.

11. The electronic device according to claim 10, wherein: The electronic device further includes a wide-angle camera module, wherein the wide-angle camera is mounted on the housing. The electronic device can obtain a telephoto image through the telephoto camera module and a wide-angle image through the wide-angle camera module.

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