Miniature lens

Abstract

The utility model relates to the technical field of optical lenses, in particular to a miniature lens, which sequentially comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens from an object side to an image side along an optical axis, the second lens has negative focal power; the third lens has negative focal power, and the object side surface of a paraxial region of the third lens is a concave surface; the fourth lens has positive focal power; the fifth lens has negative focal power, and the object side surface of a paraxial region of the fifth lens is a convex surface; the lens satisfies the conditional expression: 0.8 lt; cT1 * tan (FOV / 2) lt; 1.2; wherein CT1 is the center thickness of the first lens, and FOV is the maximum field angle of the lens. By reasonably matching the focal power, the surface type and the distribution parameters of each lens, the miniaturization of the lens is realized under the condition of ensuring the imaging quality, the area occupied by a camera in a screen is effectively reduced, the screen-to-body ratio of a full screen is improved, and the requirements of miniaturization, large aperture and high imaging quality are met.

Description

Technical Field

[0001] The utility model relates to the technical field of optical lenses, in particular to a miniature lens. Background Art

[0002] In recent years, with the market demand, mobile phone cameras have also shown a new development trend. They are not limited to requiring lenses to have high pixels and large apertures. Recently, full-screen smartphones have set off a craze in the market. The full-screen makes the installation space of the camera even smaller. Therefore, in order to adapt to the increasingly narrow installation space, the miniaturization of optical lenses is also a future development trend. Utility Model Content

[0003] In view of the above-mentioned shortcomings and deficiencies of the prior art, the utility model provides a miniature lens, which realizes the miniaturization of the lens while ensuring the imaging quality by reasonably matching the optical focal length, surface shape and distribution parameters of each lens, thereby meeting the requirements of miniaturization, large aperture and high imaging quality.

[0004] In order to achieve the above-mentioned purpose, the main technical solutions adopted by the utility model include:

[0005] The micro lens is composed of the following components from the object side to the image side along the optical axis:

[0006] The first lens has positive power and its object side surface in the paraxial region is convex;

[0007] A second lens having negative optical power;

[0008] The third lens has negative power and its object side surface in the paraxial region is concave;

[0009] a fourth lens having positive refractive power;

[0010] The fifth lens has negative power and its object side surface in the paraxial region is convex;

[0011] The lens satisfies the following conditional formula:

[0012] 0.8 <CT1*tan(FOV / 2)<1.2

[0013] Wherein, CT1 is the center thickness of the first lens, and FOV is the maximum field of view of the lens.

[0014] By satisfying the above conditional formula, the center thickness of the first lens is large, the volume distribution of the object side end of the optical lens can be adjusted, which helps to compress the outer diameter of the object side end of the optical lens for photography, so that the lens has the characteristics of a small head and a large field of view, thereby realizing the miniaturization of the lens.

[0015] Furthermore, the lens satisfies the following conditional formula:

[0016] 0.55 <R1 / F<1.0

[0017] Wherein, R1 is the radius of curvature of the object side of the first lens, and F is the focal length of the lens.

[0018] By satisfying the above conditional expressions, the sensitivity of the lens can be reduced and the processing yield can be improved.

[0019] Furthermore, the lens satisfies the following conditional formula:

[0020] 1.5 <MT5 / CT5<2

[0021] Among them, MT5 is the thickest thickness of the fifth lens, and CT5 is the center thickness of the fifth lens.

[0022] By satisfying the above conditional formula, the thickness ratio of the fifth lens can be reasonably controlled, and the difficulty of molding processing can be reduced while ensuring the performance.

[0023] Furthermore, the lens satisfies the following conditional formula:

[0024] 0.55 <F4 / F<0.8

[0025] Among them, F4 is the focal length of the fourth lens, and F is the focal length of the lens.

[0026] By satisfying the above conditional expression and reasonably selecting the focal length of the fourth lens, the lens can be better capable of correcting astigmatism and field curvature.

[0027] Furthermore, the lens satisfies the following conditional formula:

[0028] -3.5 <F2 / F<-2

[0029] Among them, F2 is the focal length of the second lens, and F is the focal length of the lens.

[0030] By satisfying the above conditional formula and reasonably selecting the focal length of the second lens, the lens can have a better ability to correct chromatic aberration.

[0031] The beneficial effects of the utility model are:

[0032] The utility model provides a miniature lens, which compresses the outer diameter of the object side end of the optical lens for photography by reasonably matching the optical focal length, surface shape and distribution parameters of each lens, realizes the miniaturization of the lens while ensuring the imaging quality, effectively reduces the area occupied by the camera in the screen, improves the screen-to-body ratio of the full screen, and meets the needs of miniaturization, large aperture and high imaging quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of the present utility model;

[0034] Figure 2The vertical axis chromatic aberration curve diagram of Example 1 of the utility model;

[0035] Figure 3 is an astigmatism curve diagram of Example 1 of the utility model;

[0036] Figure 4 This is a distortion curve diagram of Example 1 of the utility model;

[0037] Figure 5 This is a schematic diagram of the structure of Embodiment 2 of the present utility model;

[0038] Figure 6 The vertical axis chromatic aberration curve diagram of Example 2 of the utility model;

[0039] Figure 7 is an astigmatism curve diagram of Example 2 of the utility model;

[0040] Figure 8 This is a distortion curve diagram of Example 2 of the utility model;

[0041] Fig. 9 This is a schematic diagram of the structure of Embodiment 3 of the present utility model;

[0042] Fig.10 The vertical axis chromatic aberration curve diagram of Example 3 of the utility model;

[0043] Fig.11 is an astigmatism curve diagram of Example 3 of the utility model;

[0044] Fig.12 This is a distortion curve diagram of Example 3 of the present utility model.

[0045] In the figure: 1, first lens; 2, second lens; 3, third lens; 4, fourth lens; 5, fifth lens; 6, aperture; 7, filter. DETAILED DESCRIPTION

[0046] In order to better explain the present invention and facilitate understanding, the present invention is described in detail below through specific implementation modes in conjunction with the accompanying drawings.

[0047] 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.

[0048] 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 closest to the object in each lens is called the object side surface, and the surface closest to the imaging plane in each lens is called the image side surface.

[0049] The micro lens provided in the embodiment of the utility model is composed of the following components in sequence from the object side to the image side along the optical axis:

[0050] The first lens 1 has positive power, and its object side surface in the paraxial region is convex;

[0051] The second lens 2 has negative optical power;

[0052] The third lens 3 has negative optical power, and its object side surface in the paraxial region is concave;

[0053] The fourth lens 4 has positive refractive power;

[0054] The fifth lens 5 has negative optical power, and its object side surface in the paraxial region is convex;

[0055] The lens satisfies the following conditional formula:

[0056] 0.8 <CT1*tan(FOV / 2)<1.2

[0057] Wherein, CT1 is the center thickness of the first lens 1, and FOV is the maximum field of view angle of the lens.

[0058] By satisfying the above conditional formula, the center thickness of the first lens is large, the volume distribution of the object side end of the optical lens can be adjusted, which helps to compress the outer diameter of the object side end of the optical lens for photography, so that the lens has the characteristics of a small head and a large field of view, thereby realizing the miniaturization of the lens.

[0059] Specifically, the lens satisfies the following conditional formula:

[0060] 0.55 <R1 / F<1.0

[0061] Wherein, R1 is the curvature radius of the object side of the first lens 1, and F is the focal length of the lens.

[0062] By satisfying the above conditional expressions, the sensitivity of the lens can be reduced and the processing yield can be improved.

[0063] Specifically, the lens satisfies the following conditional formula:

[0064] 1.5 <MT5 / CT5<2

[0065] Among them, MT5 is the thickest thickness of the fifth lens 5, and CT5 is the center thickness of the fifth lens 5.

[0066] By satisfying the above conditional expression, the thickness ratio of the fifth lens 5 is reasonably controlled, and the difficulty of molding processing is reduced while ensuring the performance.

[0067] Specifically, the lens satisfies the following conditional formula:

[0068] 0.55 <F4 / F<0.8

[0069] Among them, F4 is the focal length of the fourth lens, and F is the focal length of the lens.

[0070] By satisfying the above conditional expression and reasonably selecting the focal length of the fourth lens 4, the lens can be better capable of correcting astigmatism and field curvature.

[0071] Specifically, the lens satisfies the following conditional formula:

[0072] -3.5 <F2 / F<-2

[0073] Wherein, F2 is the focal length of the second lens 2, and F is the focal length of the lens.

[0074] By satisfying the above conditional expression and reasonably selecting the focal length of the second lens 2, the lens can have a better ability to correct chromatic aberration.

[0075] The above-mentioned lens may further include a filter 7 for correcting color deviation and / or a protective glass for protecting the photosensitive element located on the imaging surface according to the specific needs of the embodiment. In the absence of specific requirements, the filter 7 or the protective glass may not be used.

[0076] In order to better understand the above technical solution, exemplary embodiments of the present invention will be described in more detail with reference to the accompanying drawings. Although exemplary embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to enable a clearer and more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.

[0077] Example 1

[0078] The present embodiment provides a micro lens, which is composed of an aperture 6, a first lens 1, a second lens 2, a third lens 3, a fourth lens 4, a fifth lens 5 and a filter 7 in sequence from the object side to the image side along the optical axis. The incident light passes through the above components in sequence and finally forms an image on the image plane. The first lens 1 has a positive focal power, and the object side surface of its paraxial region is a convex surface, and the image side surface is a convex surface. The second lens 2 has a negative focal power, and the object side surface of its paraxial region is a convex surface, and the image side surface is a concave surface. The third lens 3 has a negative focal power, and the object side surface of its paraxial region is a concave surface, and the image side surface is a concave surface. The fourth lens 4 has a positive focal power, and the object side surface of its paraxial region is a convex surface, and the image side surface is a convex surface. The fifth lens 5 has a negative focal power, and the object side surface of its paraxial region is a convex surface, and the image side surface is a concave surface. The filter 7 is arranged between the fifth lens 5 and the image plane.

[0079] Table 1 shows the surface type, radius of curvature, thickness and material properties of each lens in Example 1. The units of the radius of curvature, thickness and focal length are all millimeters (mm).

[0080] Table 1 is a table of lens parameters of the lens of Example 1.

[0081]

[0082]

[0083] In this embodiment, the surface shape x of each aspheric lens can be defined by, but not limited to, the following aspheric surface formula:

[0084]

[0085] 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; A i The following Table 2 shows the high-order coefficients A4, A6, A8, A10, A12, A14, A16, and A18 of the aspheric mirror surfaces S2-S11 that can be used in Example 1.

[0086] Table 2 is a table of high-order coefficients of various aspherical mirror surfaces in Example 1.

[0087]

[0088]

[0089] Table 3 below shows important parameters in Example 1.

[0090] Table 3 is a table of important parameters of Example 1.

[0091]

[0092] The specific lens structure of this embodiment is as follows Figure 1 As shown in Table 1-3 and Figure 1-4 The lens shape and various properties of the lens of the current embodiment are shown. By reasonably matching the optical focal length, surface shape and allocation parameters of each lens, the outer diameter of the object side end of the optical lens for photography is compressed, and the miniaturization of the lens is achieved while ensuring the imaging quality. The area occupied by the camera in the screen is effectively reduced, the screen-to-body ratio of the full screen is improved, and the requirements of miniaturization, large aperture and high imaging quality are met.

[0093] Example 2

[0094] The present embodiment provides a micro lens, which is composed of an aperture 6, a first lens 1, a second lens 2, a third lens 3, a fourth lens 4, a fifth lens 5 and a filter 7 in sequence from the object side to the image side along the optical axis. The incident light passes through the above components in sequence and finally forms an image on the image plane. The first lens 1 has a positive focal power, and the object side surface of its paraxial region is a convex surface, and the image side surface is a convex surface. The second lens 2 has a negative focal power, and the object side surface of its paraxial region is a concave surface, and the image side surface is a concave surface. The third lens 3 has a negative focal power, and the object side surface of its paraxial region is a concave surface, and the image side surface is a concave surface. The fourth lens 4 has a positive focal power, and the object side surface of its paraxial region is a convex surface, and the image side surface is a convex surface. The fifth lens 5 has a negative focal power, and the object side surface of its paraxial region is a convex surface, and the image side surface is a concave surface. The filter 7 is arranged between the fifth lens 5 and the image plane.

[0095] Table 4 shows the surface type, radius of curvature, thickness and material properties of each lens in Example 2. The units of the radius of curvature, thickness and focal length are all millimeters (mm).

[0096] Table 4 is a table of lens parameters of Example 2.

[0097]

[0098] In this embodiment, the surface shape of each aspheric surface can be defined by the formula (1) in the above-mentioned embodiment 1.

[0099] Table 5 below shows the high-order coefficients that can be used for each aspherical mirror surface in Example 2.

[0100] Table 5 is a table of high-order coefficients of various aspherical mirror surfaces in Example 2

[0101]

[0102]

[0103] Table 6 below shows important parameters in Example 2.

[0104] Table 6 is a table of important parameters of Example 2.

[0105]

[0106] The specific lens structure of this embodiment is as follows Figure 5 Table 4-6 and Figure 5-8 The lens shape and various properties of the lens of the current embodiment are shown. By reasonably matching the optical focal length, surface shape and allocation parameters of each lens, the outer diameter of the object side end of the optical lens for photography is compressed, and the miniaturization of the lens is achieved while ensuring the imaging quality. The area occupied by the camera in the screen is effectively reduced, the screen-to-body ratio of the full screen is improved, and the requirements of miniaturization, large aperture and high imaging quality are met.

[0107] Example 3

[0108] The present embodiment provides a micro lens, which is composed of an aperture 6, a first lens 1, a second lens 2, a third lens 3, a fourth lens 4, a fifth lens 5 and a filter 7 in sequence from the object side to the image side along the optical axis. The incident light passes through the above components in sequence and finally forms an image on the image plane. The first lens 1 has a positive focal power, and the object side surface of its paraxial region is a convex surface, and the image side surface is a convex surface. The second lens 2 has a negative focal power, and the object side surface of its paraxial region is a convex surface, and the image side surface is a concave surface. The third lens 3 has a negative focal power, and the object side surface of its paraxial region is a concave surface, and the image side surface is a concave surface. The fourth lens 4 has a positive focal power, and the object side surface of its paraxial region is a convex surface, and the image side surface is a convex surface. The fifth lens 5 has a negative focal power, and the object side surface of its paraxial region is a convex surface, and the image side surface is a concave surface. The filter 7 is arranged between the fifth lens 5 and the image plane.

[0109] Table 7 shows the surface type, radius of curvature, thickness and material properties of each lens in Example 3. The units of the radius of curvature, thickness and focal length are all millimeters (mm).

[0110] Table 7 is a table of lens parameters of Example 3.

[0111]

[0112] In this embodiment, the surface shape of each aspheric surface can be defined by the formula (1) in the above-mentioned embodiment 1.

[0113] Table 8 below shows the high-order coefficients that can be used for each aspherical mirror surface in Example 3.

[0114] Table 8 is a table of high-order coefficients of each aspherical mirror surface in Example 3.

[0115]

[0116]

[0117] Table 9 below shows important parameters in Example 3.

[0118] Table 9 is a table of important parameters of Example 3.

[0119]

[0120] The specific lens structure of this embodiment is as follows Fig. 9 Table 7-9 and Figure 9-12 The lens shape and various properties of the lens of the current embodiment are shown. By reasonably matching the optical focal length, surface shape and allocation parameters of each lens, the outer diameter of the object side end of the optical lens for photography is compressed, and the miniaturization of the lens is achieved while ensuring the imaging quality. The area occupied by the camera in the screen is effectively reduced, the screen-to-body ratio of the full screen is improved, and the requirements of miniaturization, large aperture and high imaging quality are met.

[0121] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are illustrative and cannot be understood as limitations of the present invention. Ordinary technicians in the field can change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A micro lens, characterized in that: Along the optical axis from the object side to the image side, it is composed of: The first lens has positive power and its object side surface in the paraxial region is convex; A second lens having negative optical power; The third lens has negative power and its object side surface in the paraxial region is concave; a fourth lens having positive refractive power; The fifth lens has negative power and its object side surface in the paraxial region is convex; The lens satisfies the following conditional formula: 0.8 <CT1*tan(FOV / 2)<1.2 Wherein, CT1 is the center thickness of the first lens, and FOV is the maximum field of view of the lens.

2. The micro lens according to claim 1, characterized in that: The lens satisfies the following conditional formula: 0.55 <R1 / F<1.0 Wherein, R1 is the radius of curvature of the object side of the first lens, and F is the focal length of the lens.

3. The micro lens according to claim 1, characterized in that: The lens satisfies the following conditional formula: 1.5 <MT5 / CT5<2 Among them, MT5 is the thickest thickness of the fifth lens, and CT5 is the center thickness of the fifth lens.

4. The micro lens according to claim 1, wherein: The lens satisfies the following conditional formula: 0.55 <F4 / F<0.8 Among them, F4 is the focal length of the fourth lens, and F is the focal length of the lens.

5. The micro lens according to claim 1, wherein: The lens satisfies the following conditional formula: -3.5 <F2 / F<-2 Among them, F2 is the focal length of the second lens, and F is the focal length of the lens.

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