CN201037873Y - High-image-quality miniature zoom optical system - Google Patents

Abstract

The utility model relates to a high image quality micro zoom optical system applied to a micro optical lens of a high pixel mobile phone and a high image quality camera; the utility model aims to overcome the defects of the prior art and provides a high-image quality micro zoom optical system which can be used for an ultrathin zoom digital camera and a mobile phone; it is including the first group, the second group, the third group that set gradually from the front to the back, is equipped with sensitization chip in this third group below, is provided with first lens in first group, has set gradually second lens, third lens and fourth lens in the second group, is provided with the fifth lens in the third group, first lens be biconcave plastic aspheric lens, two surfaces of second lens are biconvex glass spherical shape, the third lens are the plastic aspheric surface of falcate shape, the fourth lens are the plastic aspheric surface of falcate shape, the fifth lens be the glass aspheric surface of biconvex shape.

Description

A High Image Quality Micro Zoom Optical System

【Technical field】

The utility model relates to an optical lens, in particular to a high-image-quality miniature zoom optical system applied to the miniature optical lens of a high-pixel mobile phone and a high-image-quality camera.

【Background technique】

The currently used cameras and mobile phone digital lenses generally have such shortcomings: relatively low pixels, large dimensions, fixed focal length, and cannot zoom, which cannot guarantee clearness when shooting objects at different distances. The optical system capable of zooming is complex in structure, and the lens composition generally consists of 7-8 lenses. While the cost is high, the volume is relatively large compared to a fashionable ultra-thin mobile phone. Moreover, the current mainstream camera phones on the market are mainly fixed focal length lenses below 1.3 million. Clear camera, which has great limitations in use, cannot meet the needs of consumers for location photography.

【Content of utility model】

The utility model overcomes the deficiencies of the prior art, and provides a high-pixel, small-volume, high-image-quality micro-zoom optical system that can be used in ultra-thin zoom digital cameras and mobile phones.

In order to solve the above-mentioned technical problems, the utility model adopts the following technical solutions:

A high-quality micro-zoom optical system, including a first group, a second group, and a third group arranged in sequence from front to back, and a photosensitive chip is arranged below the third group, and it is characterized in that: The first lens is arranged in the first group, the second lens, the third lens and the fourth lens are arranged in sequence in the second group, the fifth lens is arranged in the third group, and the first lens It is a double-concave plastic aspheric lens, the two surfaces of the second lens are double-convex glass spherical shapes, the third lens is a plastic aspheric surface with a meniscus shape, the fourth lens is a plastic aspheric surface with a meniscus shape, and the fifth lens is a plastic aspheric surface with a meniscus shape. The lens is a biconvex glass aspheric surface.

A high-quality micro-zoom optical system as described above is characterized in that: the distance between the first group and the second group is between 2 mm and 8 mm, and the distance between the second group and the third group The distance between the groups is between 1.2 mm and 10 mm, and the distance between the third group and the photosensitive chip is between 2.4 mm and 4 mm.

A high image quality micro-zoom optical system as described above is characterized in that: the shape of the first aspheric surface of the first lens is elliptical, the shape of the second aspherical surface is an oblate ellipsoid, and the first aspheric surface of the third lens is aspheric. Both the spherical surface and the second aspheric surface are hyperbolic, the first aspheric surface of the fourth lens is hyperbolic, the second aspheric surface is oblate ellipsoid, and the fifth lens is hyperbolic on the first aspheric surface shape, the shape of the second aspherical surface is an ellipsoidal shape.

A high-quality micro-zoom optical system as described above is characterized in that: the surface shapes of the aspheric surfaces of the first lens, the third lens, the fourth lens, and the fifth lens satisfy the following equation: Z=cy ² /{1+√[1-(1+k)c ² y ² ]}+α ₁ y ² +α ₂ y ⁴ +α ₃ y ⁶ +α ₄ y ⁸ +α ₅ y ¹⁰ +α ₆ y ¹² + α ₇ y ¹⁴ +α ₈ y ¹⁶ .

A high-quality micro-zoom optical system as described above is characterized in that: the second lens, the third lens and the fourth lens arranged in the second group are combined to form a negative group zoom and a positive group compensation for light refraction.

A high image quality micro-zoom optical system as described above is characterized in that: the system element characteristics satisfy the following expression: the focal length of the first lens: the combined focal length of the second, third and fourth lenses: the focal length of the fifth lens Approximately equal to -2:1:2, the dispersion coefficient of the positive lens in the first, third, fourth, and fifth lens groups minus the dispersion of the negative lens in the first, third, fourth, and fifth lens groups The coefficient is greater than 25.

The above-mentioned high-quality micro-zoom optical system is characterized in that: a filter is provided between the fifth lens and the photosensitive chip.

The above-mentioned high-quality micro-zoom optical system is characterized in that: in the second group, a diaphragm is provided below the second lens, and a shutter is provided below the diaphragm.

A high-quality micro-zoom optical system as described above is characterized in that: the first group, the second group, and the third group are sequentially arranged in the seat, and a cam cylinder is arranged on the seat , a limited linear groove is opened on the bearing, and a curved groove that acts as a guide rail is opened on the inner wall of the cam cylinder, and the guide shafts on the first group and the second group respectively pass through the linear groove and enter the cam cylinder In the curved groove inside, the end of the third group is arranged in the seat, and the other end stretches out from the seat to be connected with the focus motor, and the gear on the zoom motor is meshed with the ring gear on the outside of the cam cylinder.

Compared with the prior art, the utility model has the following advantages: 1. Due to the ingenious combination of several lenses of the utility model, its digital lens can reach more than 3 million pixels, while the existing miniature digital lens is generally below 1.3 million pixels ; 2, the illuminance image surface of the utility model is uniform and bright as a whole, while most of the existing miniature digital lenses are bright in the center and dark around; 3, the utility model has high sharpness, distinct colors, and good color reproduction; 4, the utility model The new model can be used for CMOS photosensitive film with 3 million pixels, but not for other general digital lenses; 6. The most important thing is that this utility model solves the problem that the fixed focal length lens cannot form clear images for objects at different distances at the same time. An optical system can take clear photos of objects at different distances at the same time.

【Description of drawings】

Fig. 1 is the figure of the utility model in the prospect state;

Fig. 2 is the figure of the utility model in close-range state;

Fig. 3 is the figure of the utility model in closed state;

Fig. 4 is a sectional view of the assembly drawing of the present utility model;

Fig. 5 is an exploded view of the assembly drawing of the present invention.

【Detailed ways】

Below in conjunction with accompanying drawing and specific embodiment the utility model is described in further detail:

A high-quality micro-zoom optical system includes a first group 1, a second group 2, and a third group 3 arranged in sequence from front to back, and a photosensitive chip is arranged below the third group 3 (Fig. not shown in), a first lens 6 is arranged in the first group 1, a second lens 7, a third lens 8 and a fourth lens 9 are arranged in sequence in the second group 2, and in the third group 3 is provided with a fifth lens 10, the first lens 6 is a double-concave plastic aspheric lens, the two surfaces of the second lens 7 are double-convex glass spherical shapes, and the third lens 8 is a meniscus-shaped plastic Aspheric surface, the fourth lens 9 is a plastic aspheric surface in the shape of a meniscus, and the fifth lens 10 is a biconvex glass aspheric surface; the distance between the first group 1 and the second group 2 is 2mm ～8mm, the distance between the second group 2 and the third group 3 is between 1.2mm～10mm, and the distance between the third group 3 and the photosensitive chip (not shown in the figure) is between 1.2mm～10mm. Between 2.4mm and 4mm.

The surface shapes of the aspheric surfaces of the first lens 6, the third lens 8, the fourth lens 9 and the fifth lens 10 satisfy the following equation: Z=cy ² /{1+√[1-1+kc ² y ² ]}+α ₁ y ² +α ₂ y ⁴ +α ₃ y ⁶ +α ₄ y ⁸ +α ₅ y ¹⁰ +α ₆ y ¹² +α ₇ y ¹⁴ +α ₈ y ¹⁶ ; in this formula, the parameter c is the curvature corresponding to the radius, y is the radial coordinate, and its unit is the same as that of the lens length, and k is the coefficient of the conic quadratic curve. When the k coefficient is less than -1, the surface curve is a hyperbola, when it is equal to -1, it is a parabola, when it is between -1 and 0, it is an ellipse, when it is equal to 0, it is a circle, and when it is greater than 0, it is a flat ellipse. α ₁ to α ₈ respectively represent the coefficients corresponding to the radial coordinates. Through the above parameters, the shape and size of the aspheric surfaces on the front and rear sides of the lens can be precisely set. According to the design requirements of the present utility model, the shape of the first aspheric surface of the first lens 6 is elliptical, and its k coefficient is required to be between -1 and 0, and the shape of the second aspheric surface is an oblate ellipsoid, which The k-factor is greater than 1. Both the first aspherical surface and the second aspheric surface of the third lens 8 are hyperbolic, and their k coefficients are both smaller than -1. The first aspherical surface of the fourth lens 9 is hyperbolic, and its k coefficients are all less than -1, and the second aspheric surface is oblate ellipsoidal, and its k coefficients are all greater than 0. The first aspheric surface of the fifth lens 10 is hyperbolic, and its k coefficients are all less than -1, and the second aspherical surface is in the shape of an ellipsoid, and its k coefficients are all greater than 0.

The utility model needs to reduce the distance between the second lens 7 and the third lens 8 as far as possible in structure in order to reduce the refraction change angle of light between each lens and control the imaging distortion; at the same time, the third lens 8 and the fourth lens The distance between 9 also needs to be as small as possible; in order to improve the field curvature aberration, the second surface of the fifth lens 10 is designed as a hyperbolic aspheric surface; in order to reduce the diameter of the first lens 6, the first surface of the lens is designed Concave, the first lens 6 is designed as a negative lens; in order to achieve fast and clear autofocus when shooting, the fifth lens 10 of the present utility model adopts glass aspheric surface technology, and the focusing time of the system can reach within 1 second; In order to achieve fast zooming (Z0OM) when shooting, the second lens 7, the third lens 8 and the fourth lens 9 arranged in the second group 2 are combined to form the negative group zoom and positive group compensation technology of light refraction, from the close-up When the zoom end is changed to the telephoto end, the longest zoom time can reach less than 2 seconds, which is very fast.

The system component characteristic of the present utility model satisfies following expression: the focal length fl of the first lens 6: the second, the 3rd, the combined focal length f234 of the 4th lens 7,8,9: the focal length f5 of the 5th lens 10 is approximately equal to-2 : 1: 2, this ratio is to consider that the system maintains a good aberration correction state in the entire focal length range between the near view and the distant view, and realizes continuous zoom instead of segmental zoom; the first lens 6, the second The dispersion coefficient vd1345P of the positive lens in the three lenses 8, the fourth lens 9, and the fifth lens 10 group minus the dispersion of the negative lens in the first lens 6, the third lens 8, the fourth lens 9, and the fifth lens 10 group The coefficient vd1345N is greater than 25, that is, vd1345P-vd1345N>25.

In order to achieve the best color reproducibility, a filter 11 is arranged below the fifth lens 10, and the light enters from the filter 11. The filter 11 has a certain protective effect on the CMOS photosensitive chip, and at the same time It also selectively filters part of the light, making the image bright and sharp while having good color reproduction.

The two surfaces of the first lens 6 need to adopt a hyperbolic aspheric lens, which has a relatively high refractive index and a moderate dispersion ability, and the power distribution is negative, which makes the optical system with a relatively simple structure realize a large The zoom range becomes possible; the two surfaces of the second lens 7 need to adopt double-convex spherical lenses, which have high refractive power, and can effectively correct them due to their position in the optical system, low dispersion, and high refractive index. Stop position chromatic aberration and spherical aberration; the first surface of the third lens 8 is a hyperbolic aspheric surface, and the second surface must adopt a hyperbolic aspheric surface, which can effectively reduce the field curvature; The first aspheric surface of the four-lens 9 is hyperbolic, and its k coefficients are all less than -1, and the second aspherical shape is oblate ellipsoidal, and its k coefficients are all greater than 0, which can further contribute to reducing field curvature ; The first surface of the fifth lens 10 is an aspherical surface of hyperbolic shape, while the second surface adopts an ellipsoidal shape, and it has a high refractive index and a moderate degree of dispersion, and it can move a small range while To achieve better image plane motion compensation.

In the second group 2, an aperture 16 is arranged below the second lens 7, and a shutter 17 is also arranged below the aperture 16. Since the shutter 17 is arranged in the middle of the second group 2, it can reduce the The volume of the entire lens is small, but if it is not considered well, it may occur that the processing of the shutter 17 cannot be realized. In this utility model, the aberration generated by the position of the diaphragm 16 (the opening of the shutter 17) is very reasonable. , so that the aberrations are distributed reasonably and the design of the shutter 17 can be mass-produced.

In order to achieve the purpose of changing the focal length, the applicant applied for a patent on January 20, 2007 entitled: A Mechanical System for Optical Focusing and Autofocusing. The application number is: 200720047751.4, which describes in detail the realization of optical focusing and automatic focusing A mechanical system, this mechanical system can realize the distance between the first group 1 and the second group 2, the distance between the second group 2 and the third group 3, the distance between the third group 3 and CMOS The distance between the photosensitive chips may change at any time. Its structure is: a limited linear groove 41 is opened on the seat 4, and a guide rail curved groove 51 is opened on the inner wall of the cam cylinder 5. The first group 1 and the second group The guide shafts 12 and 13 on the second group 2 respectively pass through the linear groove 41 and enter the curved groove 51 in the cam cylinder 5. One end of the third group 3 is arranged in the seat 4, and the other end extends out of the seat 4 and The focus motor 14 is connected and driven by the focus motor 14 to move up and down. The gear 16 on the zoom motor 15 meshes with the ring gear 17 on the outside of the cam barrel 5 and drives the cam barrel 5 to rotate and cause the first and second groups 1, 1 and 2 to rotate. 2 for relative up and down movement.

The utility model finally uses only 5 lenses to achieve triple optical zoom and 3 million pixel optical system. Pixels, the smallest optical system.

Here is a design case of this optical system:

Group lens data record:

Profile data summary:

noodle type Radius thickness Glass diameter Conic factor Object ABCD light bar FGHIJKLM image Standard surface Aspheric surface Aspheric surface Standard surface Standard surface Aspheric surface Aspheric surface Aspherical surface Aspherical surface Aspheric surface Aspherical surface infinity-1593.2 infinity infinity 61.723-1.5-5 infinity infinity infinity 100000015.6820.380.12510.110.7561.50.20.752.197343 1.580000, 25.0000001.808000, 53.0000001.788000.29.9091851.560000, 65.0000001.500000.65.000000K9 11133266.76.123.622.641.9422.142.22.326.366.265.3411095.8845638.529702 0-0.056000-3.5-10.070.2-16-0.3000

Surface data details:

Noodles: Standard Noodles

Surface A : Aspheric surface

Coefficient of ^r2 : 0

Coefficient of ^r4 : -0.003269

Coefficient of ^r6 : -0.000459

Coefficient of ^r8 : -3.165e-005

Coefficient of r ¹⁰ : 1e-007

Coefficient of r ¹² : 0

Coefficient of r ¹⁴ : 0

Coefficient of r ¹⁶ : 0

Aperture: Variable Aperture

Maximum Radius: 3.35

Surface B : Aspherical

Coefficient of ^r2 : 0

Coefficient of ^r4 : -0.0048466

Coefficient of ^r6 : -0.0004554

Coefficient of r ⁸ : -1e-005

Coefficient of r ¹⁰ : 1.822e-007

Coefficient of r ¹² : 0

Coefficient of r ¹⁴ : 0

Coefficient of r ¹⁶ : 0

Aperture : Variable Aperture

Maximum Radius: 3.06

Noodle C : Standard Noodle

Aperture : Variable Aperture

Maximum Radius: 1.81

Noodle D : Standard Noodle

Aperture : Variable Aperture

Maximum Radius : 1.32

Surface Light Bar : Standard Surface

Surface F : Aspherical

Coefficient of ^r2 : 0

Coefficient of ^r4 : -0.02798

Coefficient of ^r6 : 0.00316

Coefficient of ^r8 : 0.000461

Coefficient of r ¹⁰ : -0.000183

Coefficient of r ¹² : 0

Coefficient of r ¹⁴ : 0

Coefficient of r ¹⁶ : 0

Aperture: Variable Aperture

Maximum Radius : 1

Surface G : Aspheric

Coefficient of ^r2 : 0

Coefficient of ^r4 : 0.007245

Coefficient of ^r6 : -0.014551

Coefficient of ^r8 : 0.01

Coefficient of ^r10 : -0.009702

Coefficient of r ¹² : 0

Coefficient of r ¹⁴ : 0

Coefficient of r ¹⁶ : 0

Aperture: Variable Aperture

Maximum Radius : 1.07

Surface H : Aspheric

Coefficient of ^r2 : 0

Coefficient of ^r4 : 0.00036

Coefficient of ^r6 : -0.0280416

Coefficient of ^r8 : 0.01

Coefficient of ^r10 : -0.0057928

Coefficient of r ¹² : 0

Coefficient of r ¹⁴ : 0

Coefficient of r ¹⁶ : 0

Aperture: Variable Aperture

Maximum Radius : 1.1

Surface I : Aspheric

Coefficient of ^r2 : 0

Coefficient of ^r4 : -0.006111

Coefficient of ^r6 : 0.0003664

Coefficient of ^r8 : -0.002902

Coefficient of ^r10 : 0.0026

Coefficient of r ¹² : 0

Coefficient of r ¹⁴ : 0

Coefficient of r ¹⁶ : 0

Aperture: variable aperture

Maximum Radius : 1.16

Surface J : Aspheric

Coefficient of ^r2 : 0

Coefficient of ^r4 : 0.0054224

Coefficient of ^r6 : -0.0004238

Coefficient of ^r8 : 2.02e-005

Coefficient of r ¹⁰ : 8.54e-007

Coefficient of r ¹² : 0

Coefficient of r ¹⁴ : 0

Coefficient of r ¹⁶ : 0

Aperture: variable aperture

Maximum Radius : 3.18

Surface K : Aspheric

Coefficient of ^r2 : 0

Coefficient of ^r4 : 0.005676

Coefficient of ^r6 : -0.0002217

Coefficient of r ⁸ : -8e-005

Coefficient of r ¹⁰ : 4.44e-006

Coefficient of r ¹² : 0

Coefficient of r ¹⁴ : 0

Coefficient of r ¹⁶ : 0

Aperture: variable aperture

Maximum Radius : 3.13

Noodles L : Standard Noodles

Noodles M : Standard Noodles

Noodles Like: Standard Noodles

Group focus moving range:

1st, 2nd group interval: 2mm-8mm

2nd, 3rd group interval: 1.2mm-10mm

3rd, photosensitive chip spacing: 2.4mm-4mm

Claims (9)

1. A micro-zoom optical system with high image quality, comprising a first group (1), a second group (2), and a third group (3) arranged in sequence from front to back, in the third group (3) A photosensitive chip is arranged below, and it is characterized in that: a first lens (6) is arranged in the first group (1), and a second lens (7) is arranged in sequence in the second group (2), The third lens (8) and the fourth lens (9), the fifth lens (10) is arranged in the third group (3), the first lens (6) is a double-concave plastic aspheric lens, the second The two surfaces of the second lens (7) are double-convex glass spherical surfaces, the third lens (8) is a plastic aspheric surface with a meniscus shape, and the fourth lens (9) is a plastic aspheric surface with a meniscus shape. The lens (10) is a biconvex glass aspherical surface. 2. A high-quality micro-zoom optical system according to claim 1, characterized in that: the distance between the first group (1) and the second group (2) is between 2 mm and 8 mm , the distance between the second group (2) and the third group (3) is between 1.2 mm and 10 mm, and the distance between the third group (3) and the photosensitive chip is between 2.4 mm and 4 mm between. 3. A kind of high image quality miniature zoom optical system according to claim 2, is characterized in that: the shape of the aspherical surface of the first lens (6) is ellipse, and the aspheric surface of the second surface is oblate ellipsoid in shape , the shape of the first aspherical surface and the second aspheric surface of the third lens (8) are both hyperbolic, the fourth lens (9) the first aspherical surface is hyperbolic, and the second aspherical surface is oblate ellipse Spherical shape, the first aspheric surface of the fifth lens (10) is hyperbolic, and the second aspheric surface is ellipsoidal. 4. A high image quality micro zoom optical system according to claim 1, 2 or 3, characterized in that: the first lens (6), the third lens (8) and the fourth lens (9) And the surface shape of the aspheric surface of the fifth lens (10) satisfies the following equation: Z=cy ² /{1+√[1-(1+k)c ² y ² ]}+α ₁ y ² +α ₂ y ⁴ +α ₃ y ⁶ +α ₄ y ⁸ +α ₅ y ¹⁰ +α ₆ y ¹² +α ₇ y ¹⁴ +α ₈ y ¹⁶ . 5. according to claim 1 or 2 or 3 described a kind of high image quality miniature zoom optical system, it is characterized in that: the second lens (7), the 3rd lens (8) that are arranged in the second group (2) ) and the fourth lens (9) are combined to form negative group zoom and positive group compensation of light refraction. 6. according to claim 1 or 2 or 3 described a kind of high image quality miniature zoom optical system, it is characterized in that: system element characteristic satisfies following expression: the focal length f1 of the first lens (6): the second, the third , the combined focal length f234 of the fourth lens (7), (8), (9): the focal length f5 of the fifth lens (10) is approximately equal to -2:1:2, the first, the third, the fourth, the fifth lens (6), (8), (9), (10) the dispersion coefficient vd1345P of the positive lens in the group minus the first, the third, the fourth, the fifth lens (7), (8), (9), (10) The dispersion coefficient vd1345N of the negative lens in the group is greater than 25. 7. A kind of high-quality micro-zoom optical system according to claim 1, characterized in that: a filter (11) is arranged between the fifth lens (10) and the photosensitive chip (18) . 8. A high-quality micro-zoom optical system according to claim 1, characterized in that: in the second group (2), an aperture (16) is provided below the second lens (7) , a shutter (17) is also provided below the diaphragm (16). 9. A high-quality micro-zoom optical system according to claim 1, characterized in that: the first group (1), the second group (2), and the third group (3) are successively Set in the seat (4), a cam cylinder (5) is provided on the seat (4), a limited linear groove (41) is opened on the seat (4), and the inner wall of the cam cylinder (5) There are curved grooves (51) that act as guide rails, and the guide shafts (12) and (13) on the first group (1) and the second group (2) respectively pass through the linear grooves (41) and enter the cam In the curved groove (51) in the barrel (5), the end of the third group (3) is set in the seat (4), and the other end protrudes from the seat (4) to connect with the focusing motor (14). The gear (16) on the zoom motor (15) meshes with the ring gear (17) on the outside of the cam barrel (5).

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