CN111830674B - Lens barrel - Google Patents
Lens barrel Download PDFInfo
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- CN111830674B CN111830674B CN201910817171.6A CN201910817171A CN111830674B CN 111830674 B CN111830674 B CN 111830674B CN 201910817171 A CN201910817171 A CN 201910817171A CN 111830674 B CN111830674 B CN 111830674B
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- lens
- lens barrel
- diameter portion
- optical axis
- barrel
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- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B13/00—Optical objectives specially designed for the purposes specified below
- G02B13/001—Miniaturised objectives for electronic devices, e.g. portable telephones, webcams, PDAs, small digital cameras
- G02B13/0015—Miniaturised objectives for electronic devices, e.g. portable telephones, webcams, PDAs, small digital cameras characterised by the lens design
- G02B13/002—Miniaturised objectives for electronic devices, e.g. portable telephones, webcams, PDAs, small digital cameras characterised by the lens design having at least one aspherical surface
- G02B13/004—Miniaturised objectives for electronic devices, e.g. portable telephones, webcams, PDAs, small digital cameras characterised by the lens design having at least one aspherical surface having four lenses
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B13/00—Optical objectives specially designed for the purposes specified below
- G02B13/06—Panoramic objectives; So-called "sky lenses" including panoramic objectives having reflecting surfaces
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B13/00—Optical objectives specially designed for the purposes specified below
- G02B13/18—Optical objectives specially designed for the purposes specified below with lenses having one or more non-spherical faces, e.g. for reducing geometrical aberration
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- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
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Abstract
The present invention relates to a lens barrel, including: a lens chamber including a lens barrel; and a plurality of lenses fixed in the lens chamber in order along the optical axis from the object side to the image side, wherein the first lens is a lens closest to the object side, an object side surface of the first lens is convex outward along the optical axis, a cross section along the optical axis is convex, the first lens comprises a first portion with a small diameter close to the object side and a second portion with a large diameter close to the image side, and a step difference is formed between the first portion and the second portion; the lens comprises a small lens diameter part close to the object side and a large lens diameter part close to the image side, the diameters of the small lens diameter part and the large lens diameter part are different, and the lens meets the following conditions: A/B is less than or equal to 0.28. Where a is the maximum outer diameter of the small-diameter first portion of the first lens L1, and B is the maximum outer diameter of the lens large-diameter portion.
Description
Technical Field
The invention relates to the field of optics, in particular to a lens.
Background
At present, a plurality of electronic devices such as mobile phones and tablet computers are equipped with front lenses. Fig. 1 is a schematic structural diagram of a lens 100 in the prior art, and fig. 2 is a partial sectional view of the lens 100 in the prior art. As shown in fig. 1 and 2, the lens barrel 100 includes a mirror chamber 101 and a plurality of lenses disposed in the mirror chamber 101, and a lens closest to the object side is a first lens 102. The first lens 102 is entirely contained inside the lens chamber 101, and the highest point of the optical effective diameter thereof is lower than the end surface of the lens chamber 101 facing the object side. In such a lens barrel, the first lens 102 occupies more space in the lens chamber 101, the viewing angle is limited, and the lens chamber 101 integrally accommodates the first lens 102 therein, resulting in a thicker lens barrel.
Disclosure of Invention
The present invention is directed to a lens, which has a relatively wide viewing angle and good optical performance, and can further reduce the thickness of the lens.
The technical scheme adopted by the invention for solving the technical problems is as follows: a lens barrel is constructed, including:
a lens chamber including a lens barrel; and
a first lens, a second lens, a third lens, and a fourth lens fixed in the lens chamber in this order from an object side to an image side along an optical axis, wherein the first lens is a lens closest to the object side, an object side surface of which is convex outward along the optical axis and a cross section along the optical axis is a convex shape, and includes a first portion having a small diameter close to the object side and a second portion having a large diameter close to the image side, and a step difference is formed between the first portion and the second portion;
the lens comprises a small lens diameter part close to the object side and a large lens diameter part close to the image side, the diameters of the small lens diameter part and the large lens diameter part are different, and the lens meets the following conditions:
A/B≤0.28
where A is the maximum outer diameter of the small-diameter first portion of the first lens, and B is the maximum outer diameter of the large-diameter lens portion.
According to the lens barrel of the present invention, the first lens includes an optically effective diameter portion and a peripheral portion for bearing against and fixing, and a thickness of the first lens on the optical axis is 1.4 times or more a thickness of the other lens on the optical axis.
According to the lens barrel of the present invention, the lens barrel includes a large diameter portion near an image side and a small diameter portion near an object side with a stepped surface formed therebetween, the lens small diameter portion is formed by the small diameter portion of the lens barrel, and the lens large diameter portion is formed by the large diameter portion of the lens barrel;
the peripheral part of the first lens is fixed in the large-diameter part of the lens barrel, and part of the optical effective diameter part is positioned in the small-diameter part of the lens barrel;
the lens barrel further comprises a cover connected to the object side end of the lens barrel, the cover is provided with an opening, and an aperture structure is formed in front of the object side face of the first lens.
According to the lens barrel of the present invention, the object-side surface of the first lens is flush with or slightly lower than the object-side surface of the cover, the lens barrel and the cover are integrally formed, and the opening of the cover is circular or polygonal.
According to the lens barrel of the present invention, the lens barrel includes an end surface facing the object side, the end surface is provided with a first lens fixing hole, a peripheral portion of the lens is fixed in the lens barrel, and a part of an optically effective diameter portion of the lens protrudes from the first lens fixing hole;
the lens small diameter portion is formed by a part of an optical effective diameter portion of the first lens, the lens large diameter portion is formed by the lens barrel, and an edge of an object side surface of the first lens forms an aperture structure of the lens.
The present invention also provides a lens barrel, including: a lens chamber including a lens barrel; and the following lenses arranged in order from the object side to the image side along the optical axis:
the first lens has positive refractive power, and the object side surface of the first lens is a convex surface;
a second lens having a negative refractive power;
a third lens having a positive refractive power;
a fourth lens having negative refractive power;
the lens satisfies at least one of the following conditions:
0.8<L1D/L1T<1.7
0<f1/L1T<5
1<EFL/L1T<4
1.9<EFL/L1D<2.6
2mm<(L1D+L1T)<5mm
3<(EFL+TTL)/L1T<9
1.5<ALT/L1T<3.5
2.5mm 2 <G1xf1<8mm 2
wherein L1D is an optical effective diameter of an object-side surface of the first lens element, L1T is a distance on an optical axis from the object-side surface to an image-side surface of the first lens element, f1 is a focal length of the first lens element, EFL is an effective focal length of the lens barrel, TTL is a total length of the lens barrel, ALT is a sum of thicknesses of the respective lens elements, and G1 is a protrusion length of the first lens element;
the lens comprises a lens small diameter part close to the object side and a lens large diameter part close to the image side, and the diameters of the lens small diameter part and the lens large diameter part are different.
According to the lens barrel of the present invention, the shape of the lens small diameter portion is circular or polygonal, and the shape of the lens large diameter portion is circular or polygonal, the lens barrel satisfying at least one of the following conditions:
A≤2.2mm
h≥0.8mm
h/H≥0.22
S1/S2<0.25
h is the thickness of the small diameter part of the lens on the optical axis, and H is the thickness of the whole lens on the optical axis; s1 is a cross-sectional area of the lens small diameter portion, and S2 is a cross-sectional area of the lens large diameter portion.
According to the lens barrel of the present invention, the lens barrel further satisfies the following conditions:
C/B≤0.38
wherein C is a maximum outer diameter of the small diameter portion of the lens barrel.
According to the lens barrel of the present invention, the lens barrel further includes:
the fifth lens is provided with positive refractive power, the image side surface of the fifth lens is a convex surface, and the fifth lens is positioned between the first lens and the second lens.
According to the lens barrel, the image side surface of the third lens is a convex surface; the image side surface of the fourth lens is a concave surface.
The implementation of the lens of the invention has the following beneficial effects: the thickness can be further reduced while having a wide viewing angle and good optical properties.
Drawings
The invention will be further described with reference to the following drawings and examples, in which:
fig. 1 is a schematic structural diagram of a lens in the prior art;
fig. 2 is a partial sectional view of a lens barrel in the related art;
fig. 3 is a schematic structural view of a lens barrel according to the present invention;
fig. 4A is a partial sectional view of a lens barrel according to the present invention;
fig. 4B is another structural diagram of a lens barrel according to the present invention;
fig. 5 is a schematic structural diagram of another embodiment of a lens barrel according to the present invention;
FIG. 6 is a partial cross-sectional view of another embodiment of a lens barrel according to the present invention;
fig. 7 is a lens configuration schematic diagram of a first embodiment of a lens barrel according to the present invention;
FIG. 8A is a field curvature diagram of the lens of FIG. 7;
FIG. 8B is a distortion diagram of the lens of FIG. 7;
fig. 9 is a lens configuration schematic diagram of a second embodiment of a lens barrel according to the present invention;
FIG. 10A is a field curvature diagram of the lens of FIG. 9;
fig. 10B is a distortion diagram of the lens barrel of fig. 9;
fig. 11 is a schematic view of a lens arrangement and an optical path of a lens barrel according to a third embodiment of the present invention;
FIG. 12A is a field curvature diagram of the lens of FIG. 11;
fig. 12B is a distortion diagram of the lens barrel of fig. 11.
Fig. 13 is a schematic view of a lens arrangement and an optical path of a fourth embodiment of a lens barrel according to the present invention;
fig. 14A is a curvature of field diagram of the lens of fig. 13;
fig. 14B is a distortion diagram of the lens barrel of fig. 13.
Fig. 15 is a lens configuration and optical path schematic diagram of a fifth embodiment of a lens barrel according to the present invention;
FIG. 16A is a field curvature diagram of the lens of FIG. 15;
fig. 16B is a distortion diagram of the lens barrel of fig. 15.
Fig. 17 is a schematic view of a lens arrangement and an optical path of a sixth embodiment of a lens barrel according to the present invention;
fig. 18A is a curvature of field diagram of the lens of fig. 17;
fig. 18B is a distortion diagram of the lens of fig. 17.
Fig. 19 is a lens configuration and optical path schematic diagram of a seventh embodiment of a lens barrel according to the present invention;
FIG. 20A is a field curvature diagram of the lens of FIG. 19;
fig. 20B is a distortion diagram of the lens barrel of fig. 19.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and do not limit the invention.
Fig. 3 is a schematic structural view of the lens barrel 20 according to the present invention; fig. 4A is a partial sectional view of the lens barrel 20 according to the present invention. In the first embodiment of the present invention, as shown in fig. 3 and 4A, the lens barrel 20 includes a lens chamber 21 and a plurality of lenses sequentially fixed in the lens chamber 21 along an optical axis OA from an object side to an image side. The first lens L1 is a lens closest to the object side, and the thickness of the first lens L1 on the optical axis is the thickest of the plurality of lenses, and the lens thickness is the distance between the object side surface and the image side surface of the lens on the optical axis, that is, the thickness of the first lens L1 on the optical axis is 1.4 times or more the thickness of the other lenses on the optical axis.
The lens chamber 21 includes a lens barrel 211 and an annular cover 212 connected to an object side end of the lens barrel 211, and the cover 212 is provided with a circular opening 212a. The lens barrel 211 may be integrally formed with the cover 212. The opening 212a may be polygonal instead of circular, as shown in fig. 4B.
The lens barrel 211 may have a cylindrical shape, or may have another shape such as a polygonal shape as shown in the drawing, and includes a large diameter portion 211a close to the image side and a small diameter portion 211b close to the object side, which are connected to each other with a stepped surface 211c formed therebetween.
The first lens L1 is disposed in the lens barrel 211 and near an object-side end of the lens barrel 211, and is fixed in the lens barrel 211 by interference fit or an adhesive. In the illustrated embodiment, the first lens L1 is of a convex type in cross section along the optical axis, including a first portion of a small diameter near the object side and a second portion of a large diameter near the image side, in which the maximum outer diameter of the first portion is significantly smaller than that of the second portion, thereby forming a significant step difference between the first portion and the second portion. Preferably, the maximum outer diameter of the second portion is more than 1.3 times the maximum outer diameter of the first portion. The first lens L1 includes an optically effective diameter portion L1-a, and a peripheral portion L1-b for bearing against fixation. One part of the optically effective diameter portion L1-a is located at the first portion of the small diameter, and the other part is located at the second portion of the large diameter. The peripheral portion L1-b is located in the second large-diameter portion and fixed in the large-diameter portion 211a of the lens barrel 211, the image-side portion of the optically effective diameter portion L1-a is located in the large-diameter portion 211a of the lens barrel 211, and the object-side portion of the optically effective diameter portion L1-a is located in the small-diameter portion 211 b.
The object-side surface of the first lens L1 protrudes outward along the optical axis OA, and is flush with or slightly lower than the object-side surface of the cover 212. The diameter of the opening 212a in the cover 212 is slightly smaller than or equal to the outer diameter of the first lens L1. This structure forms an aperture stop structure in front of the object side surface of the first lens L1.
In this embodiment, the lens 20 is also formed entirely with two portions having different diameters, i.e., a small-diameter portion near the object side formed by the small-diameter portion 211b of the lens barrel 211 and a large-diameter portion near the image side formed by the large-diameter portion 211a of the lens barrel 211. The shape of the lens small diameter portion 211b may be circular or polygonal, and the shape of the lens large diameter portion 211a may be circular or polygonal.
In this embodiment, the lens 20 satisfies at least one of the following conditional expressions:
A/B≤0.28 (1)
A≤2.2mm (2)
h≥0.8mm (3)
h/H≥0.22 (4)
S1/S2<0.25 (5)
in the above conditional expressions, a is the maximum outer diameter of the small-diameter first portion of the first lens L1; b is the maximum outer diameter of the large-diameter portion of the lens, that is, the outer diameter of the large-diameter portion 211a of the mirror chamber 21 in this embodiment; h is the thickness of the small diameter portion of the lens, i.e. the thickness of the small diameter portion 211b of the mirror chamber 21 on the optical axis OA, i.e. the distance from the object side end surface of the small diameter portion to the step surface 211c on the optical axis OA in this embodiment; h is the thickness of the entire lens 20 on the optical axis OA, i.e., the distance from the object-side end surface of the small diameter portion to the image-side end surface of the large diameter portion on the optical axis OA. S1 is a cross-sectional area of the lens small diameter portion, and S2 is a cross-sectional area of the lens large diameter portion.
Preferably, S1/S2 is 0.19 or less.
In this embodiment, the lens 20 also satisfies the following condition:
C/B≤0.38 (6)
where C is the maximum outer diameter of the small diameter portion 211b of the lens barrel 211 on the object side, in other words, the numerical value of the diameter length of C is the maximum outer diameter a of the first portion including the small diameter of the first lens L1 and the wall thickness of the cover 212.
In the lens 20, when the above conditions are satisfied, the first lens L1 can achieve a small effective diameter, a high pixel, and a high resolution.
Fig. 5 is another structural schematic diagram of the lens barrel 30 according to the present invention; fig. 6 is another partial cross-sectional view of lens barrel 30 according to the present invention. In this embodiment, the same portions as those in the above embodiment will not be described again. In another embodiment of the present invention, as shown in fig. 5 and 6, the lens barrel 30 includes a lens chamber 31 and a plurality of lenses sequentially fixed in the lens chamber 31 along an optical axis OA from an object side to an image side. The first lens L1 is the lens closest to the object side.
The lens chamber 31 includes a lens barrel 311, the lens barrel 311 is cylindrical, and a first lens fixing hole 311a is disposed on an end surface of the lens barrel 311 facing the object side. The first lens L1 is fixed in the lens barrel 311 and protrudes out of the first lens fixing hole 311a, and an object-side surface thereof protrudes outward along the optical axis OA, that is, a part of the object-side surface of the first lens L1 protrudes out of the object-side end surface of the lens barrel 311. In the illustrated embodiment, the first lens L1 has a convex cross-section along the optical axis OA and includes an optically effective diameter portion L1-a and a peripheral portion L1-b for seating. Wherein the peripheral portion L1-b is fixed within the lens barrel 311, the image side portion of the optically effective diameter portion L1-a is located within the lens barrel 311, and the object side portion of the optically effective diameter portion L1-a is projected inward from the first lens fixing hole 311a. It is understood that the shape of the first lens fixing hole 311a may be circular, but is not limited to circular, and may be other shapes such as polygonal.
In this embodiment, the edge of the object-side surface of the first lens L1 forms an aperture stop structure of the lens barrel 30. It is preferable that a peripheral surface of a portion of the first lens L1 protruding out of the lens barrel 311 is printed, blackened or atomized, and a light blocking layer structure is formed on the peripheral surface to reduce interference caused by light incident therefrom.
In this embodiment, the lens 30 is also formed integrally with two portions having different diameters, i.e., a lens small diameter portion near the object side formed by a first portion of the first lens L1 having a small diameter near the object side and a lens large diameter portion near the image side formed by the lens barrel 311. The shape of the lens small diameter portion may be circular or polygonal, and the shape of the lens large diameter portion may be circular or polygonal.
In this embodiment, the lens 30 satisfies at least one of the above conditional expressions (1) to (5):
A/B≤0.28； (1)
A≤1.385mm； (2)
h≥0.8mm (3)
h/H≥0.22 (4)
S1/S2<0.25 (5)
in the above conditional expressions, a is the maximum outer diameter of the small-diameter first portion of the first lens L1; b is the maximum outer diameter of the lens large-diameter portion, that is, the outer diameter of the lens barrel 311 in this embodiment; h is the thickness of the lens small diameter portion, i.e. the thickness of the lens barrel 311 from the first lens L1 on the optical axis OA, i.e. the distance from the object side surface of the first lens L1 to the first lens fixing hole 311a on the optical axis OA, and H is the thickness of the entire lens 30 on the optical axis OA, i.e. the distance from the object side surface of the first lens L1 to the image side end surface of the lens barrel 311 on the optical axis OA. S1 is a cross-sectional area of the lens small diameter portion, and S2 is a cross-sectional area of the lens large diameter portion.
Preferably, S1/S2 is 0.19 or less.
When the lens barrel 30 satisfies the above conditions, a wide angle of view, a small effective diameter of the first lens L1, a high pixel, and a high resolution can be realized.
In the above embodiments, the protrusion amount of the first lens L1 protruding from the large diameter portion of the lens is greater than or equal to 0.8mm, and the outer diameter of the small diameter portion of the lens is less than 2.2mm. In order to achieve this size and maintain the desired optical performance, several examples are described below.
In the following embodiments, the first lens L1 is of a convex type in cross section, but for the sake of brevity, in the optical systems of fig. 7, 9, 11, 13, 15, 17, 19, only the optically effective diameter portion thereof is shown, and the peripheral portion thereof is not shown.
Fig. 7 is a lens configuration diagram of the first embodiment of the lens barrel according to the present invention. As shown in fig. 7, the lens assembly 40 includes, in order from an object side to an image side along an optical axis OA, an aperture stop ST1, a first lens element L11, a second lens element L12, a third lens element L13, a fourth lens element L14, a filter OF1, and an image plane IMA1.
The first lens L11 has positive refractive power. The first lens element L11 is a biconvex lens, and has a convex object-side surface S2 and a convex image-side surface S3. The first lens L11 may be made of glass.
The second lens L12 has negative refractive power. The second lens element L12 is a meniscus lens element with a convex object-side surface S4 and a concave image-side surface S5. The second lens L12 may be made of plastic.
The third lens L13 has positive refractive power. The third lens element L13 is a meniscus lens element with a concave object-side surface S6 and a convex image-side surface S7. The third lens L13 may be made of plastic.
The fourth lens L14 has negative refractive power. The fourth lens element L14 is a biconcave lens element with a concave object-side surface S8 having an inflection point, and a concave image-side surface S9 having an inflection point. The fourth lens L14 may be made of plastic.
The filter OF1 has a planar object-side surface S12 and an image-side surface S13.
At least one of the first to fourth lenses L11 to L14 may have an aspherical surface, and the sag z of the aspherical surface is obtained by the following equation:
z＝ch 2 /{1+[1-(k+1)c 2 h 2 ] 1/2 }+Ah 4 +Bh 6 +Ch 8 +Dh 10 +Eh 12 +Fh 14 +Gh 16
wherein c is curvature; h is the vertical distance from any point on the lens surface to the optical axis; k is a conic coefficient; a to G are aspheric coefficients.
The lens 40 satisfies at least one of the following conditional expressions:
0.8<L1D/L1T<1.7 (7)
0<f1/L1T<5 (8)
1<EFL/L1T<4 (9)
1.9<EFL/L1D<2.6 (10)
2mm<(L1D+L1T)<5mm (11)
3<(EFL+TTL)/L1T<9 (12)
1.5<ALT/L1T<3.5 (13)
2.5mm 2 <G1xf1<8mm 2 (14)
wherein L1D is the optically effective diameter of the object-side surface S2 of the first lens L11; L1T is the core thickness of the first lens L11 on the optical axis OA, i.e., the distance from the object-side surface S2 to the image-side surface S3 of the first lens L11 on the optical axis OA. f1 is the focal length of the first lens element L11, and EFL is the effective focal length of the lens element 40. TTL is the total lens length of the lens assembly 40, i.e. the distance from the object side surface S2 of the first lens element L11 to the image plane IMA1 on the optical axis OA. ALT is the sum of thicknesses of the lenses on the optical axis, i.e., the sum of distances from the object-side surface to the image-side surface of each lens on the optical axis OA, and G1 is the protrusion length of the first lens L11, i.e., the distance from the central vertex of the object-side surface S2 of the first lens L11 to the effective radial edge of the image-side surface S3 of the first lens L11 on the optical axis OA.
In the case where the lens 40 satisfies at least one of the above conditional expressions, it can be ensured that the outer diameter of the lens small-diameter portion and the optical effective diameter of the first lens L11 are less than 2.2mm, and the entire lens 40 can maintain good optical performance.
It is understood that the cross section of the first lens L11 is not limited to a circular shape, and may have other shapes such as non-circular shape.
Table one is a table of relevant parameters of each lens of the lens 40 in fig. 7. An effective focal length EFL of the lens 40 is equal to 2.55mm, an aperture value is equal to 2, a total lens length TTL is equal to 3.92mm, a field of view is equal to 78 degrees, an optical effective diameter L1D of an object side surface S2 of the first lens L11 is equal to 1.28mm, a core thickness L1T of the first lens L11 on an optical axis is equal to 1.10mm, a total thickness ALT of the lenses is equal to 2.25mm, a focal length of the first lens L11 is 2.94mm, a focal length of the second lens L12 is-5.43 mm, a focal length of the third lens L13 is 0.87mm, and a focal length of the fourth lens L14 is-0.93 mm. The projection length G1 of the first lens L11 is equal to 1mm. The maximum outer diameter B of the large-diameter portion of the lens is equal to 6.6mm.
Watch 1
The second table is a table of relevant parameters of the aspheric surface of each lens of the lens 40 in fig. 7, where k is a Conic coefficient (Conic Constant) and a to G are aspheric coefficients.
In this embodiment, the first lens L11 is circular in cross section, and the optical effective diameter L1D of the object-side surface S2 thereof is equal to the maximum outer diameter a of the small-diameter first portion of the first lens L11. According to the calculation, a/B =1.28/6.6=0.1939 is obtained, and the conditional expression (1) is satisfied. As can be seen from tables one and two, in the lens 40, L1D/L1T =1.28/1.10=1.16, f1/L1T =2.94/1.10=2.67, EFL/L1T =2.55/1.10=2.32, EFL/L1D =2.55/1.28=1.99, l1d + l1t =1.28+1.10=2.38mm, (EFL + TTL)/L1T = (2.55 + 3.92)/1.10 =5.88, alt/L1T =2.25/1.10=2.05, gxf 1 1x2.94=2.94mm 2 . The requirements of conditional expressions (7) to (14) can be satisfied.
In addition, the optical performance of the lens 40 can also be achieved, as can be seen from fig. 8A to 8B. Fig. 8A is a curvature of field diagram of the lens 40 of fig. 7; fig. 8B is a distortion diagram of the lens 40 of fig. 7; as can be seen from fig. 8A, the curvature of field of the lens 40 is between-0.14 mm and 0.02 mm. As can be seen from fig. 8B, the distortion of the lens 40 is between-0.2% and 1.6%. In addition, the modulation transfer function value of the lens 40 is between 0.17 and 1.0 through experiments. It is obvious that the curvature of field and distortion of the lens 40 can be effectively corrected, and the Resolution (Resolution) of the lens can also meet the requirement, so as to obtain better optical performance.
Fig. 9 is a lens configuration diagram of a second embodiment of the lens barrel according to the present invention. As shown in fig. 9, the lens barrel 50 includes, in order from an object side to an image side along an optical axis OA, an aperture stop ST2, a first lens element L21, a second lens element L22, a third lens element L23, a fourth lens element L24, a filter OF2, and an image plane IMA2.
The first lens L21 has positive refractive power. The first lens element L21 is a biconvex lens element, and has a convex object-side surface S2 and a convex image-side surface S3. The first lens L21 may be made of glass.
The second lens L22 has a negative refractive power. The second lens element L22 is a meniscus lens element with a convex object-side surface S4 and a concave image-side surface S5. The second lens L22 may be made of plastic.
The third lens L23 has positive refractive power. The third lens element L23 is a meniscus lens element with a concave object-side surface S6 and a convex image-side surface S7. The third lens L23 may be made of plastic.
The fourth lens L24 has negative refractive power. The fourth lens element L24 is a biconcave lens element, and has a concave image-side surface S9 and an inflection point. The fourth lens L24 may be made of plastic.
The filter OF2 has a planar object-side surface S22 and an image-side surface S23.
It is understood that the cross section of the first lens L21 is not limited to a circular shape, and may have other shapes such as non-circular shape.
At least one of the first to fourth lenses L21 to L24 may have an aspherical surface, and the aspherical surface sag z is obtained by the following equation:
z＝ch 2 /{1+[1-(k+1)c 2 h 2 ] 1/2 }+Ah 4 +Bh 6 +Ch 8 +Dh 10 +Eh 12 +Fh 14 +Gh 16
wherein c is curvature; h is the vertical distance from any point on the lens surface to the optical axis; k is a conic coefficient; a to G are aspheric coefficients.
In the case where the lens 50 satisfies at least one of the conditional expressions (7) to (14), the outer diameter of the lens small-diameter portion and the optical effective diameter of the first lens L21 can be ensured to be less than 2.2mm, and the entire lens 50 can maintain good optical performance.
Table three is a table of parameters related to each lens of the lens 50 in fig. 9. An effective focal length EFL of the lens 50 is equal to 2.63mm, an aperture value is equal to 2, a total lens length TTL is equal to 3.95mm, a field of view is equal to 75 °, an optical effective diameter L1D of an object-side surface S2 of the first lens L21 is equal to 1.32mm, a core thickness L1T of the first lens L21 on an optical axis is equal to 1.09mm, a total thickness ALT of the respective lenses is equal to 2.44mm, a focal length of the first lens L21 is 3.08mm, a focal length of the second lens L22 is-9.04 mm, a focal length of the third lens L23 is 0.99mm, and a focal length of the fourth lens L24 is-0.96 mm. The projection length G1 of the first lens L21 is equal to 1mm. The maximum outer diameter B of the large diameter portion of the lens is equal to 6.6mm.
Watch III
Table four is a table of relevant parameters of the aspherical surface of each lens of the lens 50 in fig. 9, where k is a conical coefficient (Conic Constant) and a to G are aspherical coefficients.
In this embodiment, the first lens L21 is circular in cross section, and the optical effective diameter L1D of the object-side surface S2 thereof is equal to the maximum outer diameter a of the small-diameter first portion of the first lens L21. According to the calculation, a/B =1.32/6.6=0.2 is obtained, and the conditional expression (1) is satisfied. As can be seen from table three and table four, in the lens 50, L1D/L1T =1.32/1.09=1.21, f1/L1T =3.08/1.09=2.83, EFL/L1T =2.63/1.09=2.41, EFL/L1D =2.63/1.32=1.99, l1d + l1t =1.32+1.09=2.41mm, (EFL + TTL)/L1T = (2.63 + 3.95)/1.09 =6.04, alt/L1T =2.44/1.09=2.24, g1xf1=1 × 3.08=3.08mm 2 The requirements of conditional expressions (7) to (14) can be satisfied.
In addition, the optical performance of the lens 50 can also be achieved, as can be seen from fig. 10A to 10B. Fig. 10A is a field curvature diagram of the lens 50 of fig. 9; fig. 10B is a distortion diagram of the lens 50 of fig. 9; as can be seen from FIG. 10A, the curvature of field of the lens 50 is between-0.02 mm and 0.06 mm. As can be seen from fig. 10B, the distortion of the lens 50 is between-0.5% and 1.8%. In addition, the modulation transfer function value of the lens 50 is between 0.36 and 1.0 through experiments. It is obvious that the curvature of field and distortion of the lens 50 can be effectively corrected, and the Resolution (Resolution) of the lens can also meet the requirement, so as to obtain better optical performance.
Fig. 11 is a lens configuration diagram of a third embodiment of the lens barrel according to the present invention. As shown in fig. 11, the lens element 60 includes, in order from an object side to an image side along an optical axis OA, an aperture stop ST3, a first lens element L31, a fifth lens element L35, a second lens element L32, a third lens element L33, a fourth lens element L34, a filter OF3, and an image plane IMA3.
The first lens L31 has positive refractive power. The first lens element L31 is a biconvex lens, and has a convex object-side surface S2 and a convex image-side surface S3. The first lens L31 may be made of glass.
The fifth lens L35 has positive refractive power. The fifth lens element L35 is a meniscus lens element with a concave object-side surface S10 and a convex image-side surface S11. The fifth lens L35 may be made of plastic.
The second lens L32 has a negative refractive power. The second lens element L32 is a meniscus lens element with a concave object-side surface S4 and a convex image-side surface S5. The second lens L32 may be made of plastic.
The third lens L33 has positive refractive power. The third lens element L33 is a biconvex lens element, and has a convex object-side surface S6 and a convex image-side surface S7. The third lens L33 may be made of plastic.
The fourth lens L34 has negative refractive power. The fourth lens element L34 is a meniscus lens element with a convex object-side surface S8 having an inflection point, and a concave image-side surface S9 having an inflection point. The fourth lens L34 may be made of plastic.
The filter OF3 has a planar object-side surface S12 and an image-side surface S13.
It is understood that the cross section of the first lens L31 is not limited to be circular, and may be other shapes such as non-circular.
At least one of the first, fifth, second, third, and fourth lenses L31, L35, L32, L33, L34, and L35 may have an aspheric surface, and the sag z of the aspheric surface is obtained by the following formula:
z＝ch 2 /{1+[1-(k+1)c 2 h 2 ] 1/2 }+Ah 4 +Bh 6 +Ch 8 +Dh 10 +Eh 12 +Fh 14 +Gh 16
wherein c is curvature; h is the vertical distance from any point on the lens surface to the optical axis; k is a conic coefficient; a to G are aspheric coefficients.
When the lens 60 satisfies at least one of the conditional expressions (7) to (14), it is ensured that the outer diameter of the lens small diameter portion and the optical effective diameter of the first lens L31 are less than 2.2mm, the amount of projection of the first lens L31 from the lens barrel large diameter portion or the amount of projection from the lens barrel is greater than or equal to 0.8mm, and the entire lens 60 can maintain good optical performance.
Table five is a table of relevant parameters of each lens of the lens 60 in fig. 11. The effective focal length EFL of the lens 60 is equal to 3.175mm, the aperture value is equal to 2.25, the total lens length TTL is equal to 4.327mm, the field of view is equal to 76.7 degrees, the optical effective diameter L1D of the object-side surface S2 of the first lens L31 is equal to 1.436mm, the core thickness L1T of the first lens L31 on the optical axis is equal to 1.41mm, the total thickness ALT of the respective lenses is equal to 2.96mm, the focal length of the first lens L31 is 2.48mm, the focal length of the fifth lens L35 is 17.17mm, the focal length of the second lens L32 is-3.07 mm, the focal length of the third lens L33 is 2.20mm, and the focal length of the fourth lens L34 is-1.83 mm. The projection length G1 of the first lens L31 is equal to 1.324mm. The maximum outer diameter B of the large diameter portion of the lens is equal to 5.9mm, the maximum outer diameter C of the small diameter portion 211B of the lens barrel 211 close to the object side is equal to 2.2mm, and the single-side wall thickness of the cover 212 is 0.25mm.
Watch five
Table six is a table of relevant parameters of the aspherical surface of each lens of the lens 60 in fig. 11, where k is a Conic coefficient (Conic Constant) and a to G are aspherical coefficients.
Watch six
In this embodiment, the first lens L31 is circular in cross section, and the optical effective diameter L1D of the object-side surface S2 thereof is equal to the maximum outer diameter a of the small-diameter first portion of the first lens L31. According to the calculation, a/B =1.436/5.9=0.2434 is obtained, the conditional expression (1) is satisfied, C/B =2.2/5.9=0.3728 is satisfied, and the conditional expression is satisfied(6). As can be seen from table five and table six, in the lens 60, L1D/L1T =1.436/1.41=1.018, f1/L1T =2.48/1.41=1.76, EFL/L1T =3.175/1.41=2.25, EFL/L1D =3.175/1.436=2.21, l1d + l1t =1.436+1.41=2.846mm, (EFL + TTL)/L1T = (3.175 + 4.327)/1.41 =5.32, alt/L1T =2.96/1.41=2.10, g1xf1=1.32x2.48=3.27mm 2 The requirements of conditional expressions (7) to (14) can be satisfied.
In addition, the optical performance of the lens 60 can also be achieved, as can be seen from fig. 12A to 12B. Fig. 12A is a curvature of field diagram of the lens 60 of fig. 11; fig. 12B is a distortion diagram of the lens 60 of fig. 11; as can be seen in fig. 12A, the curvature of field of the lens 60 is between-0.05 mm and 0.05 mm. As can be seen from fig. 12B, the distortion of the lens 60 is between 0 and 2.2%. In addition, the modulation transfer function value of the lens 60 is between 0.17 and 1.0 through experiments. It is obvious that the curvature of field and distortion of the lens 60 can be effectively corrected, and the Resolution (Resolution) of the lens can also meet the requirement, so as to obtain better optical performance.
Fig. 13 is a lens configuration diagram of a fourth embodiment of the lens barrel according to the present invention. As shown in fig. 13, the lens 70 includes, in order from an object side to an image side along an optical axis OA, an aperture stop ST4, a first lens element L41, a fifth lens element L45, a second lens element L42, a third lens element L43, a fourth lens element L44, a filter OF4, and an image plane IMA4.
The first lens L41 has positive refractive power. The first lens element L41 is a meniscus lens element with a convex object-side surface S2 and a concave image-side surface S3. The first lens L41 may be made of glass.
The fifth lens L45 has positive refractive power. The fifth lens element L45 is a meniscus lens element with a concave object-side surface S10 and a convex image-side surface S11. The fifth lens L45 may be made of plastic.
The second lens L42 has negative refractive power. The second lens element L42 is a meniscus lens element with a convex object-side surface S4 and a concave image-side surface S5. The second lens L42 may be made of plastic.
The third lens L43 has positive refractive power. The third lens element L43 is a meniscus lens element with a concave object-side surface S6 and a convex image-side surface S7. The third lens L43 may be made of plastic.
The fourth lens L44 has negative refractive power. The fourth lens element L44 is a biconcave lens element with a concave object-side surface S8 and a concave image-side surface S9. The fourth lens L44 may be made of plastic.
The filter OF4 has a planar object-side surface S12 and an image-side surface S13.
It is understood that the cross section of the first lens L41 is not limited to be circular, and may be other shapes such as non-circular.
At least one of the first, fifth, second, third and fourth lenses L41, L45, L42, L43, L44 and L45 may have an aspheric surface, and the definition of the aspheric surface sag z is the same as that of the aspheric surface sag z of each lens in the first embodiment, and therefore, the description thereof is omitted here.
In the case where the lens 70 satisfies at least one of the above conditional expressions (7) to (14), it is possible to ensure that the outer diameter of the lens small diameter portion and the optical effective diameter of the first lens L41 are less than 2.2mm, the amount of projection of the first lens L2 from the lens barrel large diameter portion or the amount of projection from the lens barrel is greater than or equal to 0.8mm, and the entire lens 70 can maintain good optical performance.
Table seven is a table of relevant parameters of each lens of the lens 70 in fig. 13. The effective focal length EFL of the lens 70 is equal to 4.02mm, the aperture value is equal to 2.2, the total lens length is equal to 5.6mm, the field of view is equal to 76.3 degrees, the optical effective diameter L1D of the object-side surface S2 of the first lens L41 is equal to 1.83mm, the core thickness L1T of the first lens L41 on the optical axis is equal to 1.4mm, the total thickness ALT of the respective lenses is equal to 3.767mm, the focal length of the first lens L41 is 5.59mm, the focal length of the fifth lens L45 is 3.53mm, the focal length of the second lens L42 is-4.33 mm, the focal length of the third lens L43 is 3.08mm, and the focal length of the fourth lens L44 is-2.02 mm. The projection length G1 of the first lens L41 is equal to 1.41mm. The maximum outer diameter B of the large diameter portion of the lens is equal to 6.6mm, the maximum outer diameter C of the small diameter portion 211B of the lens barrel 211 close to the object side is equal to 2.0mm, and the single-side wall thickness of the cover 212 is 0.09mm.
Watch seven
Table eight is a table of relevant parameters of the aspherical surface of each lens of the lens 70 in fig. 9, where k is a Conic coefficient (Conic Constant) and a to G are aspherical coefficients.
Table eight
In this embodiment, the first lens L41 has a circular cross section, and the optical effective diameter L1D of the object-side surface S2 thereof is equal to the maximum outer diameter a of the small-diameter first portion of the first lens L41. According to the calculation, a/B =1.83/6.6=0.2772 is obtained, and the conditional expression (1) is satisfied, and C/B =2.0/6.6=0.3030 is obtained, and the conditional expression (6) is satisfied. As can be seen from table seven and table eight, in the lens 70, L1D/L1T =1.83/1.4=1.307, f1/L1T =5.59/1.4=3.99, EFL/L1T =4.02/1.4=2.87, EFL/L1D =4.02/1.83=2.20, l1d + l1t =1.83+1.4=3.23mm, (EFL + TTL)/L1T = (4.02 + 5.6)/1.4 =6, alt/L1T =3.767/1.4=2.69, g1xf1=1.41x5.59=7.88mm 2 The requirements of conditional expressions (7) to (14) can be satisfied.
In addition, the optical performance of the lens 70 can also be achieved, as can be seen from fig. 14A to 14B. FIG. 14A is a field curvature diagram of lens 70 of FIG. 9; fig. 14B is a distortion diagram of the lens 70 of fig. 9; as can be seen from fig. 14A, the curvature of field of the lens 70 is between-0.03 mm and 0.07 mm. As can be seen from fig. 14B, the distortion of the lens 70 is between 0 and 2.1%. In addition, the value of the modulation transfer function of the lens 70 is between 0.29 and 1.0 through experiments. It is obvious that the curvature of field and distortion of the lens 70 can be effectively corrected, and the Resolution (Resolution) of the lens can also meet the requirement, thereby obtaining better optical performance.
Fig. 15 is a schematic view of a lens configuration and an optical path of a fifth embodiment of the lens barrel according to the present invention. As shown in fig. 15, the lens 80 includes, in order from an object side to an image side along an optical axis OA, an aperture stop ST5, a first lens element L51, a fifth lens element L55, a second lens element L52, a third lens element L53, a fourth lens element L54, a filter OF5, and an image plane IMA5.
The first lens L51 has positive refractive power. The first lens element L51 is a meniscus lens element with a convex object-side surface S2 and a concave image-side surface S3. The first lens L51 may be made of glass.
The fifth lens L55 has positive refractive power. The fifth lens element L55 is a meniscus lens element with a concave object-side surface S10 and a convex image-side surface S11. The fifth lens L55 may be made of plastic.
The second lens L52 has negative refractive power. The second lens element L52 is a biconcave lens element with a concave object-side surface S4 and a concave image-side surface S5. The second lens L52 may be made of plastic.
The third lens L53 has a positive refractive power. The third lens element L53 is a biconvex lens, and has a convex object-side surface S6 and a convex image-side surface S7. The third lens L53 may be made of plastic.
The fourth lens L54 has negative refractive power. The fourth lens element L54 is a biconcave lens element with a concave object-side surface S8 and a concave image-side surface S9. The fourth lens L54 may be made of plastic.
The filter OF5 has a planar object-side surface S12 and an image-side surface S13.
It is understood that the cross section of the first lens L51 is not limited to be circular, and may be other shapes such as non-circular.
At least one of the first, fifth, second, third and fourth lenses L51, L55, L52, L53, L54 and L55 may have an aspheric surface, and the definition of the aspheric surface sag z is the same as that of the aspheric surface sag z of each lens in the first embodiment, which is not repeated herein.
In the case where the lens 80 satisfies at least one of the above conditional expressions (7) to (14), it is possible to ensure that the outer diameter of the lens small diameter portion and the optical effective diameter of the first lens L51 are less than 2.2mm, the amount of projection of the first lens L3 from the lens barrel large diameter portion or the amount of projection from the lens barrel is greater than or equal to 0.8mm, and the entire lens 80 can maintain good optical performance.
Table nine is a table of relevant parameters of each lens of the lens 80 in fig. 15. The effective focal length EFL of the lens 80 is equal to 3.983mm, the aperture value is equal to 2.25, the total lens length is equal to 5mm, the field of view is equal to 77 degrees, and the optical effective diameter L1D of the object side surface S2 of the first lens L51 is equal to 1.784mm. The core thickness L1T of the first lens L51 on the optical axis is equal to 1.385mm, the total thickness ALT of the respective lenses is equal to 3.388mm, the focal length of the first lens L51 is 4.01mm, the focal length of the fifth lens L55 is 6.71mm, the focal length of the second lens L52 is-3.64 mm, the focal length of the third lens L53 is 2.69mm, and the focal length of the fourth lens L54 is-2.06 mm. The projection length G1 of the first lens L51 is equal to 1.48mm. The maximum outer diameter B of the large diameter portion of the lens is equal to 6.6mm, the maximum outer diameter C of the small diameter portion 211B of the lens barrel 211 close to the object side is equal to 2.0mm, and the single-side wall thickness of the cover 212 is 0.1mm.
Watch nine
Table ten is a table of relevant parameters of the aspherical surface of each lens of the lens 80 in fig. 15, where k is a conical coefficient (Conic Constant) and a to G are aspherical coefficients.
Watch ten
In this embodiment, the first lens L51 has a circular cross section, and the optical effective diameter L1D of the object-side surface S2 thereof is equal to the maximum outer diameter a of the small-diameter first portion of the first lens L51. According to the calculation, a/B =1.784/6.6=0.2703 satisfying the conditional expression (1), and C/B =2.0/6.6=0.3030 satisfying the conditional expression (6) are obtained. As can be seen from tables nine and ten, in the lens 80, L1D/L1T =1.784/1.385=1.288, f1/L1T =4.01/1.385=2.90, EFL/L1T =3.983/1.385=2.88, EFL/L1D =3.983/1.784=2.23, l1d l1t =1.784+1.385=3.169, (EFL + TTL)/L1T = (3.983 + 5)/1.385 =6.49, alt/L1T =3.388/1.385=2.45, g1xf1=1.48x4.01=5.93, and the requirements of conditional expressions (7) - (14) can be satisfied. In addition, the optical performance of the lens 80 can also be achieved, as can be seen from fig. 16A to 16B. Fig. 16A is a field curvature diagram of the lens 80 of fig. 15; fig. 16B is a distortion diagram of the lens 80 of fig. 15; as can be seen from fig. 16A, the curvature of field of the lens 80 is between-0.04 mm and 0.07 mm. As can be seen from fig. 16B, the distortion of the lens 80 is between 0 and 2.1%. In addition, experiments show that the modulation transfer function value of the lens 80 is between 0.18 and 1.0. It is obvious that the curvature of field and distortion of the lens 80 can be effectively corrected, and the Resolution (Resolution) of the lens can also meet the requirement, so as to obtain better optical performance.
Compared with the prior art, the lens can further reduce the thickness, and has a wider visual angle and good optical performance.
Fig. 17 is a schematic view of a lens arrangement and an optical path of a lens barrel according to a sixth embodiment of the present invention. As shown in fig. 17, the lens 90 includes, in order from an object side to an image side along an optical axis OA, an aperture stop ST6, a first lens element L61, a fifth lens element L65, a second lens element L62, a third lens element L63, a fourth lens element L64, a filter OF6, and an image plane IMA6.
The first lens L61 has a positive refractive power. The first lens element L61 is a meniscus lens element with a convex object-side surface S2 and a concave image-side surface S3. The first lens L61 may be made of glass.
The fifth lens L65 has positive refractive power. The fifth lens element L65 is a biconvex lens element, and has a convex object-side surface S10 and a convex image-side surface S11. The fifth lens L65 may be made of plastic.
The second lens L62 has a negative refractive power. The second lens element L62 is a biconcave lens element having a concave object-side surface S4 and a concave image-side surface S5. The second lens L62 may be made of plastic.
The third lens L63 has a positive refractive power. The third lens element L63 is a biconvex lens element, and has a convex object-side surface S6 and a convex image-side surface S7. The third lens L63 may be made of plastic.
The fourth lens L64 has a negative refractive power. The fourth lens element L64 is a biconcave lens element with a concave object-side surface S8 and a concave image-side surface S9. The fourth lens L64 may be made of plastic.
The filter OF6 has a planar object-side surface S12 and an image-side surface S13.
It is understood that the cross section of the first lens L61 is not limited to a circular shape, and may have other shapes such as non-circular shape.
At least one of the first, fifth, second, third and fourth lenses L61, L65, L62, L63, L64 and L65 may have an aspheric surface, and the definition of the aspheric surface sag z is the same as that of the aspheric surface sag z of each lens in the first embodiment, which is not repeated herein.
In the case where the lens 90 satisfies at least one of the above conditional expressions (7) to (14), it is possible to ensure that the outer diameter of the lens small diameter portion and the optical effective diameter of the first lens L61 are less than 2.2mm, the amount of projection of the first lens L3 from the lens barrel large diameter portion or the amount of projection from the lens barrel is greater than or equal to 0.8mm, and the entire lens 90 can maintain good optical performance.
Table eleven is a table of relevant parameters of each lens of the lens 90 in fig. 17. The effective focal length EFL of the lens 90 is equal to 3.45mm, the aperture value is equal to 2.25, the total lens length TTL is equal to 4.546mm, the field of view is equal to 78 degrees, and the optical effective diameter L1D of the object-side surface S2 of the first lens L61 is equal to 1.55mm. The core thickness L1T of the first lens L61 on the optical axis is equal to 1.065mm, the total thickness ALT of the respective lenses is equal to 2.90mm, the focal length of the first lens L61 is 4.09mm, the focal length of the fifth lens L65 is 4.48mm, the focal length of the second lens L62 is-2.77 mm, the focal length of the third lens L63 is 1.83mm, and the focal length of the fourth lens L64 is-1.66 mm. The projection length G1 of the first lens L61 is equal to 1.105mm. The maximum outer diameter B of the large diameter portion of the lens is equal to 5.9mm.
Watch eleven
Table thirteen is a table of relevant parameters of the aspheric surface of each lens of the lens 90 in fig. 17, where k is a conical coefficient (Conic Constant) and a to G are aspheric coefficients.
Watch twelve
In this embodiment, the first lens L61 is circular in cross section, and the optical effective diameter L1D of the object-side surface S2 thereof is equal to the maximum outer diameter a of the small-diameter first portion of the first lens L61. According to the calculation, a/B =1.55/5.9=0.2627 is obtained, and the conditional expression (1) is satisfied. As can be seen from table eleven and table twelve, in the lens 90, L1D/L1T =1.55/1.065=1.46, f1/L1T =4.09/1.065=3.84, EFL/L1T =3.45/1.065=3.24, EFL/L1D =3.45/1.55=2.23, l1d l1t =1.55+1.065=2.615, (EFL + TTL)/L1T = (3.45 + 4.546)/1.065 =7.51, alt/L1T =2.90/1.065=2.72, g1xf1=1.105x4.09=4.52, and the requirements of the conditional expressions (7) - (14) can be satisfied. In addition, the optical performance of the lens 90 can also be achieved, as can be seen from fig. 18A to 18B. Fig. 18A is a curvature of field diagram of the lens 90 of fig. 17; fig. 18B is a distortion diagram of the lens 90 of fig. 17; as can be seen in FIG. 18A, the curvature of field of the lens 90 is between-0.035 mm and 0.05 mm. As can be seen from fig. 18B, the distortion of the lens 90 is between 0 and 2.2%. In addition, through experiments, the modulation transfer function value of the lens 90 is between 0.40 and 1.0. It is obvious that the curvature of field and distortion of the lens 90 can be effectively corrected, and the Resolution (Resolution) of the lens can also meet the requirement, so as to obtain better optical performance.
Fig. 19 is a schematic view of a lens arrangement and an optical path of a lens barrel according to a seventh embodiment of the present invention. As shown in fig. 19, the lens 100 includes, in order from an object side to an image side along an optical axis OA, an aperture stop ST7, a first lens element L71, a fifth lens element L75, a second lens element L72, a third lens element L73, a fourth lens element L74, a filter OF7, and an image plane IMA7.
The first lens L71 has a positive refractive power. The first lens element L71 is a meniscus lens element with a convex object-side surface S2 and a concave image-side surface S3. The first lens L71 may be made of glass.
The fifth lens L75 has positive refractive power. The fifth lens element L75 is a biconvex lens element, and has a convex object-side surface S10 and a convex image-side surface S11. The fifth lens L75 may be made of plastic.
The second lens L72 has a negative refractive power. The second lens element L72 is a biconcave lens element having a concave object-side surface S4 and a concave image-side surface S5. The second lens L72 may be made of plastic.
The third lens L73 has positive refractive power. The third lens element L73 is a biconvex lens element, and has a convex object-side surface S6 and a convex image-side surface S7. The third lens L73 may be made of plastic.
The fourth lens L74 has a negative refractive power. The fourth lens element L74 is a biconcave lens element with a concave object-side surface S8 and a concave image-side surface S9. The fourth lens L74 may be made of plastic.
The filter OF7 has a planar object-side surface S12 and an image-side surface S13.
It is understood that the cross section of the first lens L71 is not limited to be circular, and may be other shapes such as non-circular.
At least one of the first, fifth, second, third and fourth lenses L71, L75, L72, L73, L74 and L75 may have an aspheric surface, and the definition of the aspheric surface sag z is the same as that of the aspheric surface sag z of each lens in the first embodiment, which is not repeated herein.
When the lens 100 satisfies at least one of the above conditional expressions (7) to (14), it is possible to ensure that the outer diameter of the lens small diameter portion and the optical effective diameter of the first lens L71 are less than 2.2mm, the amount of projection of the first lens L3 from the lens barrel large diameter portion or the amount of projection from the lens barrel is greater than or equal to 0.8mm, and the entire lens 100 can maintain good optical performance.
Table thirteen is a table of relevant parameters for each lens of the lens 100 in fig. 19. The effective focal length EFL of the lens 100 is equal to 3.45mm, the aperture value is equal to 2.25, the total lens length TTL is equal to 4.57mm, the field of view is equal to 78.38 degrees, and the optical effective diameter L1D of the object side surface S2 of the first lens L71 is equal to 1.55mm. The core thickness L1T of the first lens L71 on the optical axis is equal to 1.275mm, the sum ALT of the thicknesses of the respective lenses is equal to 3.05mm, the focal length of the first lens L71 is 4.343mm, the focal length of the fifth lens L75 is 4.434mm, the focal length of the second lens L72 is-3.182 mm, the focal length of the third lens L73 is 2.155mm, and the focal length of the fourth lens L74 is-1.829 mm. The first lens L71 has a projection length G1 equal to 1.3428mm. The maximum outer diameter B of the large-diameter portion of the lens is equal to 5.9mm.
Watch thirteen
The following table fourteen is a table of relevant parameters of the aspheric surface of each lens of the lens 100 in fig. 19, where k is a conical coefficient (Conic Constant) and a to G are aspheric coefficients.
Table fourteen
In this embodiment, the first lens L71 is circular in cross section, and the optical effective diameter L1D of the object side surface S2 thereof is equal to the maximum outer diameter a of the small-diameter first portion of the first lens L71. According to the calculation, a/B =1.55/5.9=0.2627 is obtained, and the conditional expression (1) is satisfied. As can be seen from table thirteen and table fourteen, in the lens 100, L1D/L1T =1.55/1.275=1.22, f1/L1T =4.343/1.275=3.41, EFL/L1T =3.45/1.275=2.71, EFL/L1D =3.45/1.55=2.23, l1d + l1t =1.55+1.274=2.825, (EFL + TTL)/L1T = (3.45 + 4.57)/1.274 =6.30, alt/L1T =3.05/1.274=2.39, g1xf1 =1.34x4.343, 5.83 can satisfy the requirements of conditional expressions (7) - (14). In addition, the optical performance of the lens 100 can also meet the requirements, which can be seen from fig. 20A to 20B. Fig. 20A is a field curvature diagram of the lens 100 of fig. 19; fig. 20B is a distortion diagram of the lens barrel 100 of fig. 19; as can be seen from fig. 20A, the curvature of field of the lens 100 is between-0.05 mm and 0.04 mm. As can be seen from fig. 20B, the distortion of the lens 100 is between 0 and 2.5%. In addition, through experiments, the modulation transfer function value of the lens 100 is between 0.45 and 1.0. It is obvious that the curvature of field and distortion of the lens 100 can be effectively corrected, and the Resolution (Resolution) of the lens can also meet the requirement, so as to obtain better optical performance.
Compared with the prior art, the lens disclosed by the invention can further reduce the thickness, and has a wider viewing angle and good optical performance.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.
Claims (10)
1. A lens barrel characterized by comprising:
a lens chamber including a lens barrel; and
a first lens, a second lens, a third lens, and a fourth lens fixed in the lens chamber in this order from an object side to an image side along an optical axis, wherein the first lens is a lens closest to the object side, an object side surface of which is convex outward along the optical axis and a cross section along the optical axis is a convex shape, and includes a first portion having a small diameter close to the object side and a second portion having a large diameter close to the image side, and a step difference is formed between the first portion and the second portion;
the lens comprises a small lens diameter part close to the object side and a large lens diameter part close to the image side, the diameters of the small lens diameter part and the large lens diameter part are different, and the lens meets the following conditions:
A/B≤0.28；
1.5<ALT/L1T<3.5；
wherein a is a maximum outer diameter of the first small-diameter portion of the first lens element, B is a maximum outer diameter of the large-diameter portion of the lens barrel, L1T is a distance from an object-side surface to an image-side surface of the first lens element on the optical axis, and ALT is a sum of thicknesses of the respective lens elements on the optical axis.
2. The lens barrel according to claim 1, wherein the first lens includes an optically effective diameter portion and a peripheral portion for bearing against fixation, and a thickness of the first lens on the optical axis is 1.4 times or more a thickness of the other lens on the optical axis.
3. The lens barrel according to claim 2, wherein the lens barrel includes a large diameter portion near an image side and a small diameter portion near an object side with a stepped surface formed therebetween, the lens small diameter portion is formed by the small diameter portion of the lens barrel, and the lens large diameter portion is formed by the large diameter portion of the lens barrel;
the peripheral part of the first lens is fixed in the large-diameter part of the lens barrel, and part of the optical effective diameter part is positioned in the small-diameter part of the lens barrel;
the lens barrel further includes a cover connected to an object side end of the lens barrel, the cover having an opening, the cover forming an aperture structure in front of an object side surface of the first lens.
4. The lens barrel according to claim 3, wherein an object-side surface of the first lens is flush with or slightly lower than an object-side surface of the cover, the lens barrel is integrally formed with the cover, and an opening of the cover is circular or polygonal.
5. The lens barrel according to claim 2, wherein the lens barrel includes an end surface facing the object side, the end surface being provided with a first lens fixing hole, a peripheral portion of the lens being fixed in the lens barrel, a part of the optically effective diameter portion of the lens projecting from the first lens fixing hole;
the lens small diameter portion is formed by a part of an optically effective diameter portion of the first lens, the lens large diameter portion is formed by the lens barrel, and an edge of an object side surface of the first lens forms an aperture structure of the lens.
6. A lens barrel, characterized in that the lens barrel comprises:
a lens chamber including a lens barrel, four or five lenses; the lenses are arranged in order from an object side to an image side along an optical axis:
a first lens element having positive refractive power and having a convex object-side surface;
a second lens having a negative refractive power;
a third lens having positive refractive power;
a fourth lens having a negative refractive power;
the lens satisfies the following conditions:
A/B≤0.28；
1.5<ALT/L1T<3.5；
wherein a is a maximum outer diameter of the first small-diameter portion of the first lens element, B is a maximum outer diameter of the large-diameter portion of the lens barrel, L1T is a distance from an object-side surface to an image-side surface of the first lens element on the optical axis, and ALT is a sum of thicknesses of the respective lens elements on the optical axis;
the lens comprises a lens small diameter part close to the object side and a lens large diameter part close to the image side, and the diameters of the lens small diameter part and the lens large diameter part are different.
7. The lens barrel according to claim 1 or 6, wherein the shape of the lens small diameter portion is a circle or a polygon, and the shape of the lens large diameter portion is a circle or a polygon, and the lens barrel satisfies at least one of the following conditions:
A≤2.2mm；
h≥0.8mm；
h/H≥0.22；
S1/S2<0.25；
0.8<L1D/L1T<1.7；
0<f1/L1T<5；
1<EFL/L1T<4；
1.9<EFL/L1D<2.6；
2<(L1D+L1T)<5；
3<(EFL+TTL)/L1T<9；
2.5-woven fabric (G1xf1) woven fabric (8); h is the thickness of the small diameter part of the lens on the optical axis, and H is the thickness of the whole lens on the optical axis; s1 is a cross-sectional area of the lens minor diameter portion, S2 is a cross-sectional area of the lens major diameter portion, L1D is an optically effective diameter of an object side surface of the first lens element, f1 is a focal length of the first lens element, EFL is an effective focal length of the lens element, TTL is a distance on the optical axis from the object side surface of the first lens element to an image plane, and G1 is a distance on the optical axis from a central vertex of the object side surface of the first lens element to an effective diameter edge of the image side surface of the first lens element.
8. The lens barrel according to claim 1 or 6, characterized in that the lens barrel further satisfies the following condition:
C/B≤0.38；
wherein C is the maximum outer diameter of the small diameter portion of the lens barrel.
9. The lens barrel according to claim 1 or 6, characterized in that the lens barrel further comprises:
the fifth lens is provided with positive refractive power, the image side surface of the fifth lens is a convex surface, and the fifth lens is positioned between the first lens and the second lens.
10. The lens barrel according to claim 1 or 6, wherein an image side surface of the third lens is a convex surface; the image side surface of the fourth lens is a concave surface.
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| Application Number | Priority Date | Filing Date | Title |
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| TW108148410A TWI709778B (en) | 2019-04-18 | 2019-12-30 | Lens assembly |
| US16/834,099 US11480760B2 (en) | 2019-04-18 | 2020-03-30 | Lens assembly |
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| TWI769536B (en) * | 2020-09-28 | 2022-07-01 | 大立光電股份有限公司 | Image lens assembly, imaging apparatus and electronic device |
| TWI804305B (en) * | 2022-05-06 | 2023-06-01 | 大立光電股份有限公司 | Imaging lens assembly, camera module and electronic device |
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| JP2010191417A (en) * | 2009-02-16 | 2010-09-02 | Samsung Techwin Co Ltd | Lens system |
| CN102959448A (en) * | 2010-06-28 | 2013-03-06 | 索尼公司 | Image capture lens and image capture device |
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| KR100703469B1 (en) * | 2005-07-07 | 2007-04-03 | 삼성전자주식회사 | Optical image forming lens system |
| JP4879600B2 (en) * | 2006-02-15 | 2012-02-22 | 富士フイルム株式会社 | Imaging lens |
| JP4924141B2 (en) * | 2007-03-28 | 2012-04-25 | コニカミノルタオプト株式会社 | Imaging lens, imaging device, and portable terminal |
| JP2015111174A (en) * | 2012-03-28 | 2015-06-18 | 富士フイルム株式会社 | Imaging lens |
| TWI459026B (en) * | 2013-05-17 | 2014-11-01 | Largan Precision Co Ltd | Image capturing lens system |
| CN103543514B (en) * | 2013-06-28 | 2016-08-10 | 玉晶光电(厦门)有限公司 | Portable electronic devices and its optical imaging lens |
| JP6171184B2 (en) * | 2013-08-09 | 2017-08-02 | カンタツ株式会社 | Imaging lens |
| CN104503064B (en) * | 2014-11-19 | 2016-11-23 | 南京联河讯光电科技有限责任公司 | Comprise the micro combined optical system of 5 pieces of eyeglasses |
| JP2018146878A (en) * | 2017-03-08 | 2018-09-20 | カンタツ株式会社 | Lens element and image capturing lens unit |
| TWI626487B (en) * | 2017-03-31 | 2018-06-11 | 大立光電股份有限公司 | Optical imaging lens system, image capturing unit and electronic device |
| TWI698672B (en) * | 2017-08-11 | 2020-07-11 | 大立光電股份有限公司 | Imaging lens assembly, camera module and electronic device |
| CN108802969B (en) * | 2018-05-30 | 2021-03-16 | 广东旭业光电科技股份有限公司 | Optical imaging lens group |
| CN208399783U (en) * | 2018-07-20 | 2019-01-18 | 信泰光学(深圳)有限公司 | Lens assembly |
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| JP2010191417A (en) * | 2009-02-16 | 2010-09-02 | Samsung Techwin Co Ltd | Lens system |
| CN102959448A (en) * | 2010-06-28 | 2013-03-06 | 索尼公司 | Image capture lens and image capture device |
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| TW202040199A (en) | 2020-11-01 |
| TWI709778B (en) | 2020-11-11 |
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