CN111929847B - High-pixel large-aperture lens - Google Patents

Abstract

The invention relates to a high-pixel large-aperture lens, which is technically characterized by comprising the following components in sequence from an object side to an image side along an optical axis: a first lens having positive refractive power and a convex object-side surface; a second lens having refractive power; a third lens having refractive power; a fourth lens element having positive refractive power and having convex object-side and image-side surfaces; a fifth lens having a negative refractive power and a concave image-side surface; the diaphragm is arranged on the object side or the image side of the first lens, and the object side and the image side of each lens are aspheric. The lens has reasonable configuration and reliable use, adopts five lenses, and simultaneously meets the requirements of high pixels and large apertures and low cost.

Description

High-pixel large-aperture lens

Technical Field

The invention relates to an optical system, in particular to a high-pixel large-aperture lens which is used for a rear lens of a mobile phone.

Background

With the development of mobile phones, the lens of the mobile phone gradually develops towards the direction of high pixel and large aperture, in order to meet the requirement of high pixel, the number of lenses required by the lens is gradually increased, and the number of lenses is increased from five to six or even seven, so that the increase in cost is inevitably brought.

Disclosure of Invention

The invention aims to provide a high-pixel large-aperture lens which is reasonable in configuration and reliable in use, adopts five lenses and meets the requirements of high-pixel large aperture and low cost.

The technical point of the high-pixel large-aperture lens is that the lens sequentially comprises from an object side to an image side along an optical axis:

a first lens having positive refractive power and a convex object-side surface;

a second lens having refractive power;

A third lens having refractive power;

a fourth lens element having positive refractive power and having convex object-side and image-side surfaces;

a fifth lens having a negative refractive power and a concave image-side surface;

the diaphragm is arranged on the object side or the image side of the first lens, the object side and the image side of each lens are aspheric, and the following conditional expressions are satisfied:

TTL/ImgH＜2.0

(T3+T4)/TTL>0.21

∣R7/R8∣>35

wherein, TTL is the total optical length of the lens, imagH is half of the diagonal length of the imaging chip of the lens, T3 is the air space between the third lens and the fourth lens on the optical axis, T4 is the air space between the fourth lens and the fifth lens on the optical axis, R7 is the radius of curvature of the object side of the fourth lens, and R8 is the radius of curvature of the image side of the fourth lens.

The high-pixel large-aperture lens also meets the following conditional expression:

∣YC52/F5∣≥0.45

Wherein YC52 is the vertical distance from the inflection point of the fifth lens image-side surface off-axis to the optical axis; f5 is the focal length of the fifth lens. This condition is advantageous in reducing the thickness ratio of the fifth lens, and thus easier processing.

The high-pixel large-aperture lens also meets the following conditional expression:

∣F3/F5∣≥7.4

wherein F3 is the focal length of the third lens, and F5 is the focal length of the fifth lens. This condition is advantageous for correcting astigmatism of a lens with a large aperture.

In the above high-pixel large-aperture lens, the first lens, the second lens, the third lens, the fourth lens and the fifth lens all adopt even-order aspheric plastic lenses, and the aspheric coefficients satisfy the following equation:

Z＝cy²/[1+{1－(1+k)c²y²}^+1/2]+A₄y⁴+A₆y⁶+A₈y⁸+A₁₀y¹⁰+A₁₂y¹²+A₁₄y¹⁴+A₁₆y¹⁶

Wherein Z is aspheric sagittal, c is aspheric paraxial curvature, y is lens aperture, k is conic coefficient, A ₄ is 4 th order aspheric coefficient, A ₆ is 6 th order aspheric coefficient, A ₈ is 8 th order aspheric coefficient, A ₁₀ is 10 th order aspheric coefficient, A ₁₂ is 12 th order aspheric coefficient, A ₁₄ is 14 th order aspheric coefficient, A ₁₆ is 16 th order aspheric coefficient, A ₁₈ is 18 th order aspheric coefficient, A ₂₀ is 20 th order aspheric coefficient.

The beneficial effects of the invention are as follows:

the five lenses with reasonable configuration are adopted, and the five lenses with reasonable position relation and parameter relation are arranged, so that the requirements of high pixels and large apertures are met, and the production cost is reduced.

Drawings

FIG. 1 is a schematic view of a lens barrel according to embodiment 1 of the present invention;

FIG. 2 is an MTF curve of the lens of example 1 of the present invention;

FIG. 3 is an astigmatism curve of the lens of example 1 of the present invention;

FIG. 4 is a schematic view of a lens barrel according to embodiment 2 of the present invention;

FIG. 5 is an MTF curve of the lens of example 2 of the present invention;

FIG. 6 is an astigmatism curve of the lens of example 2 of the present invention;

FIG. 7 is a schematic view showing the structure of a lens barrel according to embodiment 3 of the present invention;

FIG. 8 is an MTF curve of the lens of example 3 of the present invention;

FIG. 9 is an astigmatism curve of the lens of example 3 of the present invention;

In the figure: p1. a first lens, p2. A second lens, p3. A third lens, p4. A fourth lens, P5. a fifth lens, stop, ima imaging plane, IR-cut filter;

1. The lens system comprises a first lens object side surface, a first lens image side surface, a second lens object side surface, a second lens image side surface, a third lens object side surface, a third lens image side surface, a fourth lens object side surface, a fourth lens image side surface, a fifth lens object side surface, a fifth lens image side surface and a fifth lens image side surface.

Detailed Description

Example 1

As shown in fig. 1, the high-pixel large-aperture lens includes, in order from an object side to an image side along an optical axis: a first lens element P1 with positive refractive power having a convex object-side surface and a concave image-side surface; a second lens element P2 with refractive power having a convex object-side surface and a concave image-side surface; a third lens element P3 with refractive power having a concave object-side surface and a convex image-side surface; a fourth lens P4 having positive refractive power, and having convex object-side and image-side surfaces; and a fifth lens P5 with negative refractive power, which has concave object-side and image-side surfaces. The STOP is disposed on the object side of the first lens P1, and the object side and the image side of each lens are aspheric.

In this embodiment, the high-pixel large-aperture lens satisfies the following conditions simultaneously:

TTL/ImgH＜2.0

(T3+T4)/TTL>0.21

∣R7/R8∣>35

∣YC52/F5∣≥0.45

∣F3/F5∣≥7.4

Wherein TTL is the total optical length of the lens, imagH is half of the diagonal length of the imaging chip of the lens, T3 is the air space between the third lens and the fourth lens on the optical axis, T4 is the air space between the fourth lens and the fifth lens on the optical axis, R7 is the radius of curvature of the object side of the fourth lens, R8 is the radius of curvature of the image side of the fourth lens, YC52 is the vertical distance from the inflection point of the image side off-axis of the fifth lens to the optical axis, F5 is the focal length of the fifth lens, F3 is the focal length of the third lens, and F5 is the focal length of the fifth lens.

The first lens, the second lens, the third lens, the fourth lens and the fifth lens are all even-order aspheric plastic lenses, and the aspheric coefficients meet the following equation:

Z＝cy²/[1+{1－(1+k)c²y²}^+1/2]+A₄y⁴+A₆y⁶+A₈y⁸+A₁₀y¹⁰+A₁₂y¹²+A₁₄y¹⁴+A₁₆y¹⁶

Wherein Z is aspheric sagittal, c is aspheric paraxial curvature, y is lens aperture, k is conic coefficient, A ₄ is 4 th order aspheric coefficient, A ₆ is 6 th order aspheric coefficient, A ₈ is 8 th order aspheric coefficient, A ₁₀ is 10 th order aspheric coefficient, A ₁₂ is 12 th order aspheric coefficient, A ₁₄ is 14 th order aspheric coefficient, A ₁₆ is 16 th order aspheric coefficient, A ₁₈ is 18 th order aspheric coefficient, A ₂₀ is 20 th order aspheric coefficient.

In this embodiment, the design parameters of the lens assembly are shown in the following table: table A shows the surface type, radius of curvature, thickness and material of each lens in example 1, the radius of curvature and thickness being in millimeters (mm)

Watch 1 (a)

Table (b) shows the aspherical coefficients of the lenses of example 1.

Watch one (b)

In this embodiment, constraint terms of each conditional expression are shown in table one (c):

watch one (c)

According to table one (a), table one (b) and fig. 1, the lens shape and various properties of the lens of the current embodiment are clearly shown, which illustrates that the current embodiment realizes the high-pixel and large-aperture characteristics of the lens by adjusting the shape and the interval of the lens.

According to table one (c) and the clear MTF curve in fig. 2, the lens has high pixel characteristics after meeting the requirements of the claims, and the astigmatism curve in fig. 3 shows that the lens has good astigmatism concentration, which is beneficial to improving the image quality of the lens.

Example 2

As shown in fig. 3, the high-pixel large-aperture lens includes, in order from an object side to an image side along an optical axis: a first lens element with positive refractive power having a convex object-side surface and a concave image-side surface; a second lens element with refractive power having a convex object-side surface and a concave image-side surface; a third lens element with refractive power having convex object-side and image-side surfaces; a fourth lens element having positive refractive power and having convex object-side and image-side surfaces; and a fifth lens with negative refractive power, wherein the object side surface and the image side surface are concave. The diaphragm is arranged on the image side of the first lens, and the object side surface and the image side surface of each lens are aspheric.

In this embodiment, the design parameters of the lens assembly are shown in the following table: table two (a) shows the surface type, radius of curvature, thickness, and material of each lens of example 2. Wherein, the unit of curvature radius and thickness is millimeter (mm).

The design parameters of the lens assembly of the present embodiment are shown in the following table:

watch II (a)

Lens	Surface serial number	Surface type	Radius of curvature	Thickness of (L)	Material Properties (Nd: vd)
							OBJ	Spherical surface	inf	Infinity
P1	1	Aspherical surface	1.91194	0.6804187	1.5445.55.987
							2	Aspherical surface	9.58954	0.04870594
Diaphragm	Stop	Spherical surface	Infinity	0.05
						P2	3	Aspherical surface	14.41942	0.4095057	1.6612.20.354
	4	Aspherical surface	4.605003	0.4090797
						P3	5	Aspherical surface	31.7796	0.4511049	1.5445.55.987
	6	Aspherical surface	-22.95768	0.6085319
						P4	7	Aspherical surface	110.005	0.5844163	1.5445.55.987
	8	Aspherical surface	-2.768539	0.7024277
						P5	9	Aspherical surface	-6.332499	0.5352935	1.5445.55.987
	10	Aspherical surface	2.353129	0.4261727
						BK7	11	Spherical surface	Infinity	0.21	BK7
	12	Spherical surface	Infinity	0.3743431
						IMA			Infinity

Table two (b) shows the aspherical coefficients of the lenses of example 2.

Watch II (b)

In this embodiment, constraint terms of each conditional expression are shown in table two (c):

Watch II (c)

According to table two (a), table two (b) and fig. 4, the lens shape and various properties of the lens of the current embodiment are shown more clearly, which illustrates that the current embodiment realizes the high pixel and large aperture characteristics by adjusting the shape and interval of the lens.

According to table two (c) and the clear MTF curve in FIG. 5, after meeting the requirements of the right claim, the lens has the characteristic of meeting high pixels; the astigmatic curve of fig. 6 shows that the lens has good astigmatic concentration, which is beneficial for improving the image quality of the lens.

Example 3

As shown in fig. 7, the high-pixel large-aperture lens includes, in order from an object side to an image side along an optical axis: a first lens element with positive refractive power having a convex object-side surface and a concave image-side surface; a second lens element with refractive power having a convex object-side surface and a concave image-side surface; a third lens element with refractive power having a concave object-side surface and a convex image-side surface; a fourth lens element having positive refractive power and having convex object-side and image-side surfaces; and a fifth lens with negative refractive power, wherein the object side surface and the image side surface are concave. The diaphragm is arranged on the image side of the first lens, and the object side surface and the image side surface of each lens are aspheric.

In this embodiment, the design parameters of the lens assembly are shown in the following table: table three (a) shows the surface type, radius of curvature, thickness, and material of each lens of example 3. Wherein, the unit of curvature radius and thickness is millimeter (mm).

The design parameters of the lens assembly of the present embodiment are shown in the following table:

Watch III (a)

Lens	Surface serial number	Surface type	Radius of curvature	Thickness of (L)	Material Properties (Nd: vd)
							OBJ	Spherical surface	inf	inf
Diaphragm	Stop	Spherical surface	inf	-0.377477
						P1	1	Aspherical surface	1.844143	0.6863608	1.5445.55.987
	2	Aspherical surface	8.637877	0.0855723
						P2	3	Aspherical surface	9.060788	0.3	1.6612.20.354
	4	Aspherical surface	3.850704	0.438631
						P3	5	Aspherical surface	-16.20873	0.5916108	1.5445.55.987
	6	Aspherical surface	-6.828716	0.7001226
						P4	7	Aspherical surface	91	0.5798867	1.5445.55.987
	8	Aspherical surface	-2.573844	0.4901743
						P5	9	Aspherical surface	-6.82568	0.5590948	1.5162.5703
	10	Aspherical surface	1.939617	0.5811196
						IR	13	Spherical surface	Infinity	0.21	BK7
	14	Spherical surface	Infinity	0.2644271
						IMA

Table three (b) shows the aspherical coefficients of the lenses of example 1.

In this embodiment, constraint terms of each conditional expression are shown in table three (c):

Watch III (c)

According to table three (a), table three (b) and fig. 7, the lens shape and various properties of the lens of the current embodiment are shown more clearly, which illustrates that the current embodiment realizes high pixel and large aperture characteristics by adjusting the shape and interval of the lens.

According to table three (c) and the clear MTF curve in FIG. 8, after the lens meets the requirement of the right claim, the lens has the characteristic of meeting high pixels; the astigmatic curve of fig. 9 shows that the lens has good astigmatic concentration, which is beneficial for improving the image quality of the lens.

Claims (2)

1. A high-pixel large-aperture lens, comprising, in order from an object side to an image side along an optical axis:

a first lens having positive refractive power and a convex object-side surface;

a second lens having refractive power;

A third lens having refractive power;

a fourth lens element having positive refractive power and having convex object-side and image-side surfaces;

a fifth lens having a negative refractive power and a concave image-side surface;

the diaphragm is arranged on the object side or the image side of the first lens, the object side and the image side of each lens are aspheric, and the following conditional expressions are satisfied:

TTL/ImgH ＜ 2.0

(T3+T4)/TTL > 0.21

∣R7/R8∣ > 35

∣YC52/F5∣≥ 0.45

∣F3/F5∣≥7.4

Wherein, TTL is the total optical length of the lens, imagH is half of the diagonal length of an imaging chip of the lens, T3 is the air space of the third lens and the fourth lens on the optical axis, T4 is the air space of the fourth lens and the fifth lens on the optical axis, R7 is the curvature radius of the object side surface of the fourth lens, and R8 is the curvature radius of the image side surface of the fourth lens; YC52 is the vertical distance from the inflection point of the fifth lens element at the image-side surface off-axis to the optical axis; f5 is the focal length of the fifth lens; f3 is the focal length of the third lens and F5 is the focal length of the fifth lens.

2. The high pixel large aperture lens of claim 1, wherein the first lens, the second lens, the third lens, the fourth lens and the fifth lens each adopt an even-order aspherical plastic lens, and wherein the aspherical coefficients satisfy the following equation:

Z ＝ cy²／[1+ {1－(1+k)c² y²}^＋1/2]＋A₄y⁴+A₆y⁶＋A₈y⁸＋A₁₀y¹⁰+ A₁₂y¹²+ A₁₄y¹⁴+ A₁₆y¹⁶

Wherein Z is aspheric sagittal, c is aspheric paraxial curvature, y is lens aperture, k is conic coefficient, A ₄ is 4 th order aspheric coefficient, A ₆ is 6 th order aspheric coefficient, A ₈ is 8 th order aspheric coefficient, A ₁₀ is 10 th order aspheric coefficient, A ₁₂ is 12 th order aspheric coefficient, A ₁₄ is 14 th order aspheric coefficient, A ₁₆ is 16 th order aspheric coefficient, A ₁₈ is 18 th order aspheric coefficient, A ₂₀ is 20 th order aspheric coefficient.