CN114609763A - Miniaturized optical lens, imaging device and portable terminal - Google Patents

Abstract

The invention relates to an optical instrument, in particular to a miniaturized optical lens, an imaging device and a portable terminal, which solves the problem that the optical lens of the existing miniaturized imaging device is difficult to adapt to a larger detector target surface under the condition of small volume, and at the same time The technical problem that it is difficult to have a higher optical modulation transfer function at a higher spatial frequency; the miniaturized optical lens includes a lens diaphragm, a first lens, a second lens, a first lens, a second lens, a lens diaphragm, a first lens, a second lens, a Three lenses, the fourth lens, the fifth lens and the focal plane; the refractive power ranges of the first lens and the fifth lens are both 0.002 < absolute value of refractive power <0.003; the refractive power range of the second lens is 0.3 < focus Absolute value of degree <0.4; the refractive power range of the third lens and the fourth lens are both 0.25 < absolute value of optical power <0.3; the imaging device including the miniaturized optical lens has the characteristics of small size, light weight and large aperture , especially suitable for portable terminal applications.

Description

A miniaturized optical lens, imaging device and portable terminal

technical field

The invention relates to an optical lens and an optical instrument, in particular to a miniaturized optical lens, an imaging device and a portable terminal.

Background technique

With the development of mobile phone, security and automotive imaging technology, the demand for miniaturized camera devices is increasing. The requirements for the optical lens of the miniaturization of the camera are usually considered from two aspects. On the one hand, the pixels of the detector of the miniaturized camera are getting smaller and smaller, and on the other hand, the number of pixels of the detector of the miniaturized camera is increasing The more, so that the optical lens of the miniaturized camera device needs to be compatible with a larger detector target surface while having a small volume, and has a higher optical modulation transfer function at a higher spatial frequency. However, it is difficult for miniaturized optical lenses to meet the above requirements.

SUMMARY OF THE INVENTION

The purpose of the present invention is to solve the problem that the optical lens of the existing miniaturized camera device is difficult to adapt to a larger detector target surface under the condition of small volume, and it is difficult to have a higher optical modulation transfer function at a higher spatial frequency. Therefore, a miniaturized optical lens, an imaging device and a portable terminal are provided, which are small in size, light in weight and large in aperture, and are especially suitable for mobile phone applications.

In order to solve the above-mentioned technical problems, the technical scheme adopted in the present invention is:

A miniaturized optical lens of the present invention is special in that it comprises a lens diaphragm, a first lens, a second lens, a third lens, a fourth lens, a fifth lens and focal plane;

The first lens, the second lens, the third lens, the fourth lens and the fifth lens are all double-sided aspheric surfaces, and their diameters are all ≤5mm;

The refractive power ranges of the first lens and the fifth lens are both 0.002<absolute value of refractive power<0.003;

The refractive power range of the second lens is 0.3 < absolute value of refractive power < 0.4;

The refractive power ranges of the third lens and the fourth lens are both 0.25<absolute value of refractive power<0.3.

Further, the first aspheric surface of the first lens is concave.

Further, the aspheric coefficients of the first lens, the second lens, the third lens, the fourth lens and the fifth lens all satisfy the aspheric formula;

The aspheric coefficients of the first surface of the first lens are A1, B1, C1, and D1, respectively, where A1, B1, C1, and D1 satisfy the following conditions:

0.015＜A1＜0.02, 0.009＜B1＜0.01, -0.004＜C1＜-0.003, 0.0008＜D1＜0.0009;

The aspheric coefficients of the second surface of the first lens are respectively a1, b1, c1, d1, and e1, where a1, b1, c1, d1, and e1 satisfy the following conditions:

0.02＜a1＜0.03, 0.001＜b1＜0.002, 0.0003＜c1＜0.0004, -0.0007＜d1＜-0.0006, 0.0002＜e1＜0.0003;

The aspheric coefficients of the first surface of the second lens are A2, B2, C2, and D2, respectively, where A2, B2, C2, and D2 satisfy the following conditions:

0.0025＜A2＜0.003,-0.002＜B2＜-0.0015,-0.00025＜C2＜-0.002,-0.00025＜D2＜-0.002;

The aspheric coefficients of the second surface of the second lens are a2, b2, c2, d2, and e2, respectively, where a2, b2, c2, d2, and e2 satisfy the following conditions:

0.003＜a2＜0.0035, -0.0015＜b2＜-0.001, 0.00015＜c2＜0.0002, -0.00045＜d2＜-0.0004, 4.5× ^10-5 ＜e2＜5× ^10-5 ;

The aspheric coefficients of the first surface of the third lens are A3, B3, C3, and D3, respectively, where A3, B3, C3, and D3 satisfy the following conditions:

-0.009＜A3＜-0.008, -0.003＜B3＜-0.0027, 0.0006＜C3＜0.0007, 7.7× ^10-5 ＜D3＜8× ^10-5 ;

The aspheric coefficients of the second surface of the third lens are a3, b3, c3, d3, and e3, respectively, where a3, b3, c3, d3, and e3 satisfy the following conditions:

-0.04＜a3＜-0.035, 0.004＜b3＜0.0045, -0.0045＜c3＜-0.004, 0.0015＜d3＜0.002, -0.00035＜e3＜-0.0003;

The aspheric coefficients of the first surface of the fourth lens are A4, B4, C4, and D4, respectively, wherein A4, B4, C4, and D4 satisfy the following conditions:

0.004＜A4＜0.004, 0.006＜B4＜0.0065, -0.0015＜C4＜-0.001, 7.7× ^10-5 ＜D4＜8× ^10-5 ;

The aspheric coefficients of the second surface of the fourth lens are respectively a4, b4, c4, d4, e4, f4, and g4, wherein a4, b4, c4, d4, e4, f4, and g4 satisfy the following conditions:

0.025＜a4＜0.03, -0.001＜b4＜-0.00095, 0.002＜c4＜0.0025, -0.00045＜d4＜-0.0004, 1.95× ^10-5 ＜e4＜2× ^10-5 ,-1.45× ^10-6 ＜f4 <-1.4× ^10-6 , 4.25× ^10-7 <g4<4.3× ^10-7 ;

The aspheric coefficients of the first surface of the fifth lens are respectively A5, B5, and C5, wherein A5, B5, and C5 satisfy the following conditions:

-0.07＜A＜-0.065, 0.02＜B＜0.025, -0.0025＜C＜-0.002;

The aspherical coefficients of the second surface of the fifth lens are a4, b4, c4, and d4, where a4, b4, c4, and d4 satisfy the following conditions:

-0.095<a4<-0.09, 0.02<b4<0.025, -0.003<c4<-0.0025, 9×10 ⁻⁵ <d4<9.5×10 ⁻⁵ .

Further, the materials of the first lens and the third lens are zf series high refractive index and low dispersion glass;

The material of the second lens is lak series high refractive index and high dispersion glass;

The material of the fourth lens is zlaf series high refractive index and high dispersion glass;

The material of the fifth lens is zf series low refractive index and low dispersion glass.

Further, the diameter of the first lens is less than or equal to 2.7mm;

The diameters of the second lens, the third lens and the third lens are all less than or equal to 3.8mm;

The diameter of the fourth lens is less than or equal to 4.5mm;

The diameter of the fifth lens is less than or equal to 4.8mm.

Further, the diameter of the lens stop is 2mm; the diagonal of the focal plane is 5.64mm.

Further, the distance between the lens diaphragm and the focal plane is 7.6 mm; the focal length f is 4.4 mm; and the relative aperture 1/F is 1/2.2.

The present invention also provides an imaging device, which is special in that it includes the above-mentioned miniaturized optical lens.

In addition, the present invention also provides a portable terminal, which is special in that it includes the above-mentioned imaging device.

Compared with the prior art, the beneficial effects of the technical solution of the present invention are:

1. The miniaturized optical lens of the present invention adopts the design of five double-sided aspherical lenses, the distance between the lens diaphragm and the focal plane is 7.6mm, and the diameter of the largest lens among the five double-sided aspherical lenses is Φ5mm, and the focal point is Φ5mm. The plane size can reach 5.67mm, making the optical lens small in size, its weight is estimated to be less than or equal to 0.2g, the focal length is 4.4mm, and the F number is 2.2; at the same time, it has a higher optical modulation transfer function at a higher spatial frequency, The optical modulation transfer function of the full field of view is better than 0.3 at 200lp/mm, and the distortion of the full field of view is within 5%. It is suitable for detectors below 1/2.84 inches, and the resolution can reach more than 200lp/mm, which makes the spherical aberration of the optical lens. And astigmatism correction is better, the image quality is good.

2. The first lens of the miniaturized optical lens of the present invention is concave toward the object to be measured, and the front end is not easily bumped after adjustment.

3. The structure distribution of the miniaturized optical lens of the present invention is reasonable, there is no lens interference, and it is easy to process and assemble.

4. The miniaturized optical lens of the present invention is small in size, light in weight, and large in aperture, and is especially suitable for applications in portable terminals such as mobile phones.

Description of drawings

1 is a schematic structural diagram of an embodiment of a miniaturized optical lens according to the present invention;

2 is a schematic diagram of an optical modulation transfer function of an embodiment of a miniaturized optical lens of the present invention;

3 is a schematic diagram of a distortion curve of an embodiment of a miniaturized optical lens of the present invention;

4 is a schematic diagram of a spherical aberration curve of an embodiment of a miniaturized optical lens of the present invention;

FIG. 5 is a schematic diagram of an astigmatism curve of an embodiment of a miniaturized optical lens of the present invention.

The reference numbers in the figure are:

1-first lens, 2-second lens, 3-third lens, 4-fourth lens, 5-fifth lens, 6-focal plane, 7-lens diaphragm.

Detailed ways

The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are a part of the embodiments of the present invention, but not all of the embodiments. Based on the technical solutions in the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present invention.

As shown in FIG. 1, a miniaturized optical lens includes a lens diaphragm 7, a first lens 1, a second lens 2, a third lens 3, a fourth lens 4, a lens stop 7, a first lens 1, a second lens 2, a third lens 3, a fourth lens 4, and a Five lenses 5 and a focal plane 6; the lens stop 7 is located in front of the first lens 1, and is arranged coaxially with the first lens 1; the focal plane 6 is located after the fifth lens 5, and is arranged coaxially with the fifth lens 5; The incident light passes through the lens diaphragm 7 , the first lens 1 , the second lens 2 , the third lens 3 , the fourth lens 4 , and the fifth lens 5 in sequence to reach the focal plane 6 .

Among them, the first lens 1, the second lens 2, the third lens 3, the fourth lens 4, and the fifth lens 5 all adopt double-sided aspheric surfaces, and the types of materials are different.

The front lens diaphragm 7 reduces the exposed size of the optical lens and the outer diameter of the lens of the entire optical lens, and at the same time effectively reduces the volume and weight of the optical lens. The length between the lens stop 7 and the focal plane 6 is 7.6 mm, and the largest diameter among the first lens 1 , the second lens 2 , the third lens 3 , the fourth lens 4 , and the fifth lens 5 is Φ5 mm. The focal length f of the optical lens is 4.4mm, the F-number of the optical lens is 2.2, and its full field of view distortion is within 5%. It is suitable for detectors below 1/2.84 inches, and the resolution can reach more than 200lp/mm. The estimated weight is less than Equal to 0.2g.

In this embodiment, the aspheric coefficients of the first lens 1, the second lens 2, the third lens 3, the fourth lens 4 and the fifth lens 5 all satisfy the aspheric formula;

The diameter of the first lens 1 is less than or equal to 2.7mm, the material of the first lens 1 is zf series high-refractive index and low-dispersion glass, the optical power is 0.002<absolute value of the optical power<0.003, and the aspheric coefficient of the first surface of the first lens 1 They are A1, B1, C1, and D1, respectively, where A1, B1, C1, and D1 satisfy the following conditions: 0.015<A1<0.02, 0.009<B1<0.01, -0.004<C1<-0.003, 0.0008<D1<0.0009; The aspheric coefficients of the second surface of a lens 1 are a1, b1, c1, d1, and e1, respectively, where a1, b1, c1, d1, and e1 satisfy the following conditions: 0.02<a1<0.03, 0.001<b1<0.002, 0.0003 ＜c1＜0.0004, -0.0007＜d1＜-0.0006, 0.0002＜e1＜0.0003;

The diameter of the second lens 2 is less than or equal to 3.8mm, the material of the second lens 2 is lak series high refractive index and high dispersion glass, the optical power is 0.3<absolute value of the optical power<0.4, the aspheric coefficient of the first surface of the second lens 2 They are A2, B2, C2, and D2, respectively, among which A2, B2, C2, and D2 satisfy the following conditions: 0.0025＜A2＜0.003, -0.002＜B2＜-0.0015, -0.00025＜C2＜-0.002, -0.00025＜D2＜ -0.002; the aspheric coefficients of the second surface of the second lens 2 are a2, b2, c2, d2, and e2, respectively, where a2, b2, c2, d2, and e2 satisfy the following conditions: 0.003<a2<0.0035, -0.0015< b2＜-0.001, 0.00015＜c2＜0.0002,-0.00045＜d2＜-0.0004, 4.5× ^10-5 ＜e2＜5× ^10-5 ;

The diameter of the third lens 3 is less than or equal to 3.8mm, the material of the third lens 3 is zf series high refractive index and low dispersion glass, the optical power is 0.25<absolute value of the optical power<0.3, the aspheric coefficient of the first surface of the third lens 3 They are A3, B3, C3, and D3, respectively, among which A3, B3, C3, and D3 satisfy the following conditions: -0.009＜A3＜-0.008, -0.003＜B3＜-0.0027, 0.0006＜C3＜0.0007, 7.7×10 ^-5 <D3<8×10 ⁻⁵ ; the aspheric coefficients of the second surface of the third lens 3 are respectively a3, b3, c3, d3, and e3, where a3, b3, c3, d3, and e3 satisfy the following conditions: −0.04< a3＜-0.035, 0.004＜b3＜0.0045, -0.0045＜c3＜-0.004, 0.0015＜d3＜0.002, -0.00035＜e3＜-0.0003;

The diameter of the fourth lens 4 is less than or equal to 4.5mm, the material of the fourth lens 4 is zlaf series high refractive index and high dispersion glass, the optical power is 0.25<absolute value of the optical power<0.3, the aspheric coefficient of the first surface of the fourth lens 4 They are A4, B4, C4, and D4, respectively, among which A4, B4, C4, and D4 satisfy the following conditions: 0.004＜A4＜0.004, 0.006＜B4＜0.0065, -0.0015＜C4＜-0.001, 7.7×10 ^-5 ＜D4 <8×10 ⁻⁵ ; the aspheric coefficients of the second surface of the fourth lens 4 are respectively a4, b4, c4, d4, e4, f4, and g4, wherein a4, b4, c4, d4, e4, f4, and g4 satisfy the following Conditions: 0.025＜a4＜0.03, -0.001＜b4＜-0.00095, 0.002＜c4＜0.0025, -0.00045＜d4＜-0.0004, 1.95× ^10-5 ＜e4＜2× ^10-5 ,-1.45× ^10-6 <f4<-1.4× ^10-6 , 4.25× ^10-7 <g4<4.3× ^10-7 ;

The diameter of the fifth lens 5 is less than or equal to 4.8mm, the material of the fifth lens 5 is zf series low-refractive index and low-dispersion glass, the optical power is 0.002<absolute value of the optical power<0.003, and the aspheric coefficient of the first surface of the fifth lens 5 They are A5, B5, and C5, respectively, where A5, B5, and C5 satisfy the following conditions: -0.07<A<-0.065, 0.02<B<0.025, -0.0025<C<-0.002; the second surface of the fifth lens 5 is aspherical The coefficients are a4, b4, c4, and d4, respectively, where a4, b4, c4, and d4 satisfy the following conditions: -0.095＜a4＜-0.09, 0.02＜b4＜0.025, -0.003＜c4＜-0.0025, 9×10 ^{- 5} < d4 < 9.5×10 ⁻⁵ .

In this embodiment, the aspherical surface of the first surface of the first lens 1 is concave, and the diagonal of the focal plane 6 is 5.64 mm, which can satisfy the imaging of cameras below 1/2.84 inch; the lens diaphragm 7 is located at the front, and its diameter is 2mm.

As shown in Figure 2, it can be seen from the optical modulation transfer function diagram of the optical lens that the optical modulation transfer function of the central field of view can reach 0.65@200lp/mm, and the optical modulation transfer function of the full field of view can reach 0.3@200lp/mm. Better imaging results can be achieved.

As shown in FIG. 3 , it is the distortion curve of the optical lens provided by the present invention. It can be seen from the figure that the distortion is well controlled, and the full field of view distortion can be controlled within 5%.

As shown in FIG. 4 and FIG. 5 , it is the spherical aberration curve and the astigmatism curve provided by the present invention. It can be seen from the figures that the spherical aberration and astigmatism of the lens are well corrected.

The miniaturized optical lens of the present invention can be applied to an imaging device; the imaging device can also be applied to a portable terminal, where the terminal device can be a detection device such as a computer, a notebook, a handheld computer, a mobile phone, and various cloud servers.

Claims (9)

1. A miniaturized optical lens characterized by: the optical lens comprises a lens diaphragm (7), a first lens (1), a second lens (2), a third lens (3), a fourth lens (4), a fifth lens (5) and a focal plane (6), which are coaxially arranged in sequence along the light incidence direction;

the first lens (1), the second lens (2), the third lens (3), the fourth lens (4) and the fifth lens (5) are both double-sided aspheric surfaces, and the diameters of the double-sided aspheric surfaces are less than or equal to 5 mm;

the focal power ranges of the first lens (1) and the fifth lens (5) are both more than 0.002 and less than 0.003;

the focal power range of the second lens (2) is more than 0.3 and less than 0.4;

the focal power ranges of the third lens (3) and the fourth lens (4) are respectively more than 0.25 and less than 0.3.

2. The miniaturized optical lens of claim 1, wherein: the first aspheric surface of the first lens (1) is a concave surface.

3. The miniaturized optical lens of claim 2, wherein: the aspheric coefficients of the first lens (1), the second lens (2), the third lens (3), the fourth lens (4) and the fifth lens (5) all satisfy an aspheric formula;

the first surface aspheric surface coefficients of the first lens (1) are A1, B1, C1 and D1 respectively, wherein A1, B1, C1 and D1 meet the following conditions:

0.015＜A1＜0.02，0.009＜B1＜0.01，-0.004＜C1＜-0.003，0.0008＜D1＜0.0009；

the aspheric coefficients of the second surface of the first lens (1) are a1, b1, c1, d1 and e1 respectively, wherein a1, b1, c1, d1 and e1 meet the following conditions:

0.02＜a1＜0.03，0.001＜b1＜0.002，0.0003＜c1＜0.0004，-0.0007＜d1＜-0.0006，0.0002＜e1＜0.0003；

the first surface aspheric surface coefficients of the second lens (2) are A2, B2, C2 and D2 respectively, wherein A2, B2, C2 and D2 meet the following conditions:

0.0025＜A2＜0.003，-0.002＜B2＜-0.0015，-0.00025＜C2＜-0.002，-0.00025＜D2＜-0.002；

the aspheric coefficients of the second surface of the second lens (2) are a2, b2, c2, d2 and e2 respectively, wherein a2, b2, c2, d2 and e2 meet the following conditions:

0.003＜a2＜0.0035，-0.0015＜b2＜-0.001，0.00015＜c2＜0.0002，-0.00045＜d2＜-0.0004，4.5×10^-5＜e2＜5×10^-5；

the first-surface aspheric coefficients of the third lens (3) are A3, B3, C3 and D3 respectively, wherein A3, B3, C3 and D3 meet the following conditions:

-0.009＜A3＜-0.008，-0.003＜B3＜-0.0027，0.0006＜C3＜0.0007，7.7×10^-5＜D3＜8×10^-5；

the aspheric coefficients of the second surface of the third lens (3) are a3, b3, c3, d3 and e3 respectively, wherein a3, b3, c3, d3 and e3 meet the following conditions:

-0.04＜a3＜-0.035，0.004＜b3＜0.0045，-0.0045＜c3＜-0.004，0.0015＜d3＜0.002，-0.00035＜e3＜-0.0003；

the first-surface aspheric coefficients of the fourth lens (4) are A4, B4, C4 and D4 respectively, wherein A4, B4, C4 and D4 meet the following conditions:

0.004＜A4＜0.004，0.006＜B4＜0.0065，-0.0015＜C4＜-0.001，7.7×10^-5＜D4＜8×10^-5；

the aspheric coefficients of the second surface of the fourth lens (4) are a4, b4, c4, d4, e4, f4 and g4 respectively, wherein a4, b4, c4, d4, e4, f4 and g4 meet the following conditions:

0.025＜a4＜0.03，-0.001＜b4＜-0.00095，0.002＜c4＜0.0025，-0.00045＜d4＜-0.0004，1.95×10^-5＜e4＜2×10^-5，-1.45×10^-6＜f4＜-1.4×10^-6，4.25×10^-7＜g4＜4.3×10^-7；

the first surface aspheric surface coefficients of the fifth lens (5) are A5, B5 and C5 respectively, wherein A5, B5 and C5 meet the following conditions:

-0.07＜A＜-0.065，0.02＜B＜0.025，-0.0025＜C＜-0.002；

the aspheric coefficients of the second surface of the fifth lens (5) are a4, b4, c4 and d4 respectively, wherein a4, b4, c4 and d4 meet the following conditions:

-0.095＜a4＜-0.09，0.02＜b4＜0.025，-0.003＜c4＜-0.0025，9×10^-5＜d4＜9.5×10^-5。

4. the miniaturized optical lens of claim 3, wherein: the materials of the first lens (1) and the third lens (3) are zf series high-refractive-index low-dispersion glass;

the second lens (2) is made of lak series high-refractive-index high-dispersion glass;

the fourth lens (4) is made of zlaf series high-refractive-index high-dispersion glass;

the material of the fifth lens (5) is zf series low-refractive-index low-dispersion glass.

5. The miniaturized optical lens of claim 4, wherein: the diameter of the first lens (1) is less than or equal to 2.7 mm;

the diameters of the second lens (2), the third lens (3) and the third lens (3) are less than or equal to 3.8 mm;

the diameter of the fourth lens (4) is less than or equal to 4.5 mm;

the diameter of the fifth lens (5) is less than or equal to 4.8 mm.

6. The miniaturized optical lens of claim 5, wherein: the diameter of the lens diaphragm (7) is 2 mm;

the diagonal of the focal plane (6) is 5.64 mm.

7. The miniaturized optical lens of claim 6, wherein: the distance between the lens diaphragm (7) and the focal plane (6) is 7.6 mm; the focal length f is 4.4 mm; the relative pore diameter 1/F is 1/2.2.

8. An image forming apparatus characterized by: comprising a miniature optical lens as claimed in any of claims 1-7.

9. A portable terminal characterized by: comprising the imaging device of claim 8.

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