KR101898547B1 - Imaging lens - Google Patents

Abstract

The present invention relates to an imaging lens.
That is, the imaging lens of the present invention comprises: a first lens having positive refractive power and arranged in order from the object side; A second lens having a negative refractive power; A third lens having positive refractive power; And a fourth lens having positive refractive power; And a fifth lens having negative refracting power. When the total focal length of the imaging lens is f and the image height of the image is H, a conditional expression of H / f < 1.5 is satisfied.

Description

[0001] IMAGING LENS [0002]

The present invention relates to an imaging lens.

Recently, a camera module for a communication terminal, a digital still camera (DSC), a camcorder, a PC camera (an image pickup device attached to a personal computer), and the like have been studied in connection with an image pick-up system . The most important component for obtaining an image of a camera module related to such an image pickup system is an imaging lens for imaging an image.

An attempt has been made to construct a high-resolution imaging lens using five conventional lenses. Each of the five lenses is composed of a lens having a positive refractive power and a lens having a negative refractive power. For example, an imaging lens is constructed in the structure of PNNPN (+ - + -), PNPNN (+ - + -), or PPNPN (++ - + -) in this order from the object side. However, the imaging module having the above structure does not exhibit satisfactory optical characteristics or aberration characteristics in some cases, and a high-resolution imaging lens having a new power structure is required.

The present invention is capable of increasing the height of an image formed on a light receiving element even if shift of an image to be formed is allowed by motion of a lens barrel due to the correction of camera shake by an OIS (Optical Image Stabilizer) To solve the problem that a small imaging lens optical system for preventing camera shake which can enhance the resolving power of the lens and improve the aberration characteristic can be realized.

According to the present invention,

A method of manufacturing an image pickup device, comprising:

A first lens having positive refractive power;

A second lens having a negative refractive power;

A third lens having positive refractive power; And

A fourth lens having positive refractive power; And

And a fifth lens having negative refractive power,

When the total focal length of the imaging lens is f and the image height of the image is H,

H / f < 1.5

Is satisfied. &Lt; / RTI &gt;

The first lens is formed so that the object side surface is convex.

The second lens is concave on the upper side.

Further, the fifth lens includes at least one inflection point.

In addition, when the distance from the object side surface of the first lens to the imaging surface is? T, a conditional expression of? T / H < 0.8 is satisfied.

Further, when the total focal length of the imaging lens is f and the focal length of the first lens is f1, a conditional expression of 0.5 < f1 / f < 1.5 is satisfied.

Further, when the focal length of the first lens is f1 and the focal length of the second lens is f2, the conditional expression 1 <f2 / f1 | <2 is satisfied.

When the total focal length of the imaging lens is f and the distance from the object side surface of the first lens to the imaging surface is? T, the conditional expression of 0.5 <? T / f <1.5 is satisfied.

In addition, when the radius of curvature of the first lens object side is R11 and the radius of curvature of the first lens surface side is R12, the following conditional expression 1 <| R11 / R12 | <3 is satisfied.

delete

delete

The imaging lens of the present invention is made up of five lenses, which can correct aberrations, realize a clear image, raise the height of the image formed on the light receiving element, and realize a compact imaging lens optical system for preventing camera shake It is effective.

1 is a block diagram of a camera lens module according to an embodiment of the present invention.
FIGS. 2A to 2C are graphs showing coma aberration according to an embodiment of the present invention. FIG.
3 is a graph showing aberration diagrams according to an embodiment of the present invention

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

1 is a block diagram of a camera lens module according to an embodiment of the present invention.

An image pickup lens made up of a plurality of lenses is arranged around the optical axis Z0. In the configuration diagram of Fig. 1, the thickness, size and shape of the lens are shown somewhat exaggerated for explanatory purposes, and spherical or aspherical But is not limited to this shape.

 1, a camera lens module according to the present invention includes a first lens 10, a second lens 20, a third lens 30, a fourth lens 40, a fifth lens 40, 50, a filter 60 and a light receiving element 70 are disposed.

The light corresponding to the image information of the object is passed through the first lens 10, the second lens 20, the third lens 30, the fourth lens 40, the fifth lens 50, and the filter 60 And is incident on the light receiving element 70.

The image lens of the present invention includes five lenses including the first lens 10, the second lens 20, the third lens 30, the fourth lens 40 and the fifth lens 50 As described later, a clear image can be realized while correcting the aberration, height of the image formed on the light receiving element 70 can be raised, and a compact imaging lens optical system for preventing camera shake can be realized There is an advantage.

That is, in the imaging lens of the present invention, the height of the image formed on the light receiving element 70 is relatively large, and movement of the lens barrel is caused by the correction of the shaking motion by the OIS (Optical Image Stabilizer) (Hereinafter referred to as &quot; OIS shift &quot;) is permitted, the resolution of the lens can be improved and the aberration characteristic can be improved.

As shown in FIG. 1, five lenses including the first lens 10, the second lens 20, the third lens 30, the fourth lens 40 and the fifth lens 50, The height of the image formed on the light receiving element 70 can be enlarged to the edge of the light receiving element 70 and the height of the image formed by the OIS shift tolerance A according to the movement of the lens barrel . &Lt; / RTI &gt;

Hereinafter, the term " object side " refers to a surface of the lens that faces the object side with respect to the optical axis, and " upper side " refers to a lens that faces the imaging surface with respect to the optical axis, .

The first lens 10 has a positive refractive power and the object side surface S1 can be formed convexly.

The second lens 20 has a negative refractive power, and the upper surface S4 may be concave.

The third lens 30 and the fourth lens 40 have a positive refractive power and the fifth lens 50 has a negative refractive power and include at least one inflection point.

Further, the diaphragm may be located on the object side of the front end of the first lens 10.

In FIG. 1, 'S2' is the upper side of the first lens 10, 'S3' is the object side of the second lens 20, 'S5' is the object side of the third lens 30 S7 'is the upper surface of the fourth lens 30, S8 is the object side surface of the fourth lens 40, and S9' and S8 ' 'S10' is the object side and upper side of the fifth lens 50, 'S11' and 'S12' are the object side and upper side of the filter 60, 'S13' to be.

The filter 60 is at least one of an infrared filter, an optical filter such as a cover glass, and the like. As the filter 60, when an infrared filter is applied, the radiation heat emitted from the external light is blocked from being transmitted to the light receiving element 70. In addition, the infrared ray filter transmits visible light, and the infrared ray reflects the infrared ray to the outside.

The light receiving element 70 is an image sensor such as a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor).

It will be apparent to those skilled in the art that the conditional expressions and embodiments described below are preferred embodiments for increasing the operating effect, and that the present invention is not necessarily constituted by the following conditions. For example, the lens configuration of the present invention may have an elevated action effect even if only the conditional formulas of some of the conditional expressions described below are satisfied.

[Conditional expression 1] H / f < 1.5

[Conditional expression 2]? T / H < 0.8

[Conditional expression 3] 0.5 <f1 / f <1.5

[Conditional expression 4] 1 <f 2 / f 1 | <2

[Conditional expression 5] 0.5 < T / f < 1.5

[Conditional expression 6] 1 <R11 / R12 <3

delete

delete

Here, H: Image height to be imaged

f: total focal length of the imaging lens

f1 and f2: the focal lengths of the first and second lenses

? T: the distance from the object side surface of the first lens to the image plane

R11: Radius of curvature of the first lens object side

R12: the first lens-side curvature radius

delete

Conditional expressions 1 and 2 specify the image height. Further, in the conditional expression 1, the image height can be defined in more detail by satisfying the condition of 1.0 < H / f < 1.47.

That is, the image height 'H' of the five imaging lenses of the present invention should be designed to be larger than the entire focal distance 'f' of the imaging lens and smaller than 1.47 times the focal length 'f' of the imaging lens .

The conditional expression (3) defines the refractive power of the first lens (10). The first lens 10 has a refractive power having a proper chromatic aberration and correcting the spherical aberration according to the conditional expression (3).

The conditional expression 4 defines the refractive power of the first lens 10 and the second lens 20 and the conditional expression 5 defines the dimension in the optical axis direction of the entire optical system and is a condition for the aberration lens and a condition for proper aberration correction .

The conditional expression (6) defines the radius of curvature of the first lens (10).

Hereinafter, the operation and effect of the present invention will be described with reference to specific examples. The aspherical surface referred to in the following embodiments is obtained from the known equation (1), and the 'E and the following number' used for the conic constant k and the aspherical coefficients A, B, C, D, Lt; / RTI &gt; For example, E + 01 represents 10 ¹ and E-02 represents 10 ^-2 .

Where z is the distance from the apex of the lens in the direction of the optical axis

c: The basic curvature of the lens

Y: Distance in the direction perpendicular to the optical axis

K: Conic constant

A, B, C, D, E, F: aspheric coefficient

[Example]

The following Table 1 shows the radius of curvature, thickness or distance, and refractive index of the imaging lens.

Face number The radius of curvature (R) Thickness or distance (d) Refractive index (N) One* 1.9 0.734842 1.53 2* -7.42188 0.1 3 * 8.746922 0.3 1.64 4* 2.14769 0.323715 5 * 8.595553 0.43 1.53 6 * 18.65393 0.302485 7 * -4.35814 0.569904 1.53 8* -1.25659 0.24691 9 * 4.709432 0.53 1.53 10 * 1.031567 0.723021

In Table 1 and Table 2 below, an asterisk (*) next to the face number indicates an aspherical surface.

The following Table 2 shows values of aspherical surface coefficients of each lens in the embodiment of Table 1 above.

Face number R k A B C D E One* 1.9 -1.09977 0.008177 -0.01094 -0.01357 0.013687 -0.0222 2* -7.42188 0 -0.0108 -0.04843 0.018101 -0.01985 -0.00268 3 * 8.746922 0 -0.06194 0.049413 -0.07738 0.04949 -0.01089 4* 2.14769 -12.1299 0.052652 -0.00283 -0.01311 0.008003 -0.00214 5 * 8.595553 0 -0.12494 0.039129 -0.00085 0.026728 -0.01038 6 * 18.65393 0 -0.08339 -0.03226 0.023182 -0.00652 0.012993 7 * -4.35814 -29.8775 0.036326 -0.03624 -0.02104 0.022842 -0.00549 8* -1.25659 -1.05868 0.123477 -0.02247 0.002187 0.002866 -0.00095 9 * 4.709432 -307.723 -0.21554 0.11921 -0.04611 0.011225 -0.00111

FIGS. 2A to 2C are graphs illustrating coma aberration according to an exemplary embodiment of the present invention. The tangential aberration of each wavelength and the sagittal aberration of each wavelength depend on the field height. .

As shown in FIGS. 2A to 2C, the graph showing the experimental results is close to the X axis on the positive axis and the negative axis, respectively, so that the coma aberration correction function is good.

FIG. 3 is a graph showing aberration diagrams according to an embodiment of the present invention, and is a graph measuring longitudinal spherical aberration, astigmatic field curves, and distortion in order from the left.

In Fig. 3, the Y axis represents the size of the image, and the X side represents the focal length (in mm) and distortion (in%). In FIG. 3, as the curves approach the Y-axis, it is interpreted that the aberration correction function is better. In the illustrated aberration diagrams, since the values of the images are adjacent to the Y axis in almost all fields, the values of the pitch, the astigmatism and the distortion aberration are relatively good.

That is, since the range of the pupil plane difference is -0.020 mm to +0.019 mm, the range of the astigmatism is -0.005 mm to +0.030 mm, and the range of the distortion aberration is 0.00 mm to + 2.50 mm, The spherical aberration, the astigmatism, and the distortion aberration can be corrected, and the lens characteristic is excellent.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (14)

A method of manufacturing an image pickup device, comprising:
A first lens having positive refractive power;
A second lens having a negative refractive power;
A third lens having positive refractive power;
A fourth lens having positive refractive power;
A fifth lens having a negative refractive power; And
And a diaphragm positioned at the front end of the object side of the first lens,
When the total focal length of the imaging lens is f and the image height of the image is H,
1.0 <H / f <1.47
Satisfy the conditional expression of &quot;
The object side surface of the third lens includes at least one inflection point,
Wherein the magnitude of the absolute value of the curvature radius of the object side surface of the first lens is smaller than the magnitude of the absolute value of the curvature radius of the image side surface of the first lens,
The object side surface of the fifth lens includes at least three inflection points,
Wherein the object side surface of the fifth lens has a first convex surface, a first concave surface extending downward from the first convex surface, a second convex surface extending downward from the first concave surface, A second concave surface extending downward from the first concave surface and a third convex surface extending downward from the second concave surface, the second convex surface being disposed on the optical axis,
An imaginary line extending in the optical axis direction at an inflection point formed between the first convex surface and the first concave surface and an inflection point formed between the second concave surface and the third convex surface passes through the fourth lens Imaging lens. The method according to claim 1,
Wherein the first lens comprises:
Wherein the object side surface is convex. 3. The method of claim 2,
And the second lens comprises:
An imaging lens having an upper surface concave. delete delete The method of claim 3,
The focal length of the imaging lens is f, and the focal length of the first lens is f1,
0.5 < f1 / f < 1.5
Satisfies the following conditional expression. The method according to claim 6,
When the focal length of the first lens is f1 and the focal length of the second lens is f2,
1 < f2 / f1 < 2
Satisfies the following conditional expression. 8. The method of claim 7,
F is a total focal distance of the imaging lens, and? T is a distance from the object side surface of the first lens to the imaging surface,
0.5 < T / f < 1.5
Satisfies the following conditional expression. delete delete delete The method according to claim 1,
The second lens has a refractive index of 1.61,
And the central region of the fourth lens is formed thicker than the other region. An imaging lens including a plurality of lenses and an image sensor positioned below the imaging lens and converting the optical image into an electrical signal,
Wherein the imaging lens includes, in order from the object side,
A first lens having positive refractive power;
A second lens having a negative refractive power;
A third lens having positive refractive power;
A fourth lens having positive refractive power;
A fifth lens having a negative refractive power; And
And a diaphragm positioned at the front end of the object side of the first lens,
When the total focal length of the imaging lens is f and the image height of the image is H,
1.0 <H / f <1.47
Satisfy the conditional expression of &quot;
The object side surface of the third lens includes at least one inflection point,
Wherein the magnitude of the absolute value of the curvature radius of the object side surface of the first lens is smaller than the magnitude of the absolute value of the curvature radius of the image side surface of the first lens,
The object side surface of the fifth lens includes at least three inflection points,
Wherein the object side surface of the fifth lens has a first convex surface, a first concave surface extending downward from the first convex surface, a second convex surface extending downward from the first concave surface, A second concave surface extending downward from the first concave surface and a third convex surface extending downward from the second concave surface, the second convex surface being disposed on the optical axis,
An imaginary line extending in the optical axis direction at an inflection point formed between the first convex surface and the first concave surface and an inflection point formed between the second concave surface and the third convex surface passes through the fourth lens Camera module. A camera module including an imaging lens including a plurality of lenses and an image sensor positioned below the imaging lens and converting an optical image into an electrical signal,
Wherein the imaging lens includes, in order from the object side,
A first lens having positive refractive power;
A second lens having a negative refractive power;
A third lens having positive refractive power;
A fourth lens having positive refractive power;
A fifth lens having a negative refractive power; And
And a diaphragm positioned at the front end of the object side of the first lens,
When the total focal length of the imaging lens is f and the image height of the image is H,
1.0 <H / f <1.47
Satisfy the conditional expression of &quot;
The object side surface of the third lens includes at least one inflection point,
Wherein the magnitude of the absolute value of the curvature radius of the object side surface of the first lens is smaller than the magnitude of the absolute value of the curvature radius of the image side surface of the first lens,
The object side surface of the fifth lens includes at least three inflection points,
Wherein the object side surface of the fifth lens has a first convex surface, a first concave surface extending downward from the first convex surface, a second convex surface extending downward from the first concave surface, A second concave surface extending downward from the first concave surface and a third convex surface extending downward from the second concave surface, the second convex surface being disposed on the optical axis,
An imaginary line extending in the optical axis direction at an inflection point formed between the first convex surface and the first concave surface and an inflection point formed between the second concave surface and the third convex surface passes through the fourth lens Image pickup system.

Images