KR101892299B1 - Imaging lens - Google Patents

Abstract

The present invention relates to an imaging lens.
That is, the imaging lens of the present invention comprises, in order from the object side, a first lens having negative (-) refractive power and capable of moving in two axes of an X axis and a Y axis; A second lens having positive refractive power; A third lens having negative refractive power; A fourth lens having positive refractive power; And a fifth lens having a negative refracting power, and the effective focal length of the first lens is f1, the conditional expression f1 > 800mm | 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 a lens for imaging an image.

Recently, a lens optical system is composed of five lenses composed of a lens having a positive refractive power and a lens having a negative refractive power.

For example, Korean Patent Laid-Open Publication No. 2009-0048298 discloses an image pickup lens suitable for mounting a small information terminal using five lenses.

These five lenses must have satisfactory optical characteristics or aberration characteristics, and it is required to realize an optical system having high performance and high resolution.

An object of the present invention is to solve the problem that the deterioration of the image quality due to the shaking of the user can be corrected.

According to the present invention,

In order from the object side,

A first lens having a negative refractive power and capable of moving in two axes of an X axis and a Y axis;

A second lens having positive refractive power;

A third lens having negative refractive power;

A fourth lens having positive refractive power;

And a fifth lens having negative refractive power,

And an effective focal length of the effective focal length of the first lens is f1,

an imaging lens satisfying a conditional expression of f1 > 800mm | is provided.

In one embodiment of the present invention, the first lens and the second lens are meniscus shapes having both sides convex on the object side.

The third lens has a concave shape on both sides, and the fourth lens has a meniscus shape convex upward.

Further, the fifth lens has a meniscus shape convex upward in the optical axis region.

In addition, the first lens has a mejerk shape convex to the object side.

The first lens to the fifth lens are aspherical surfaces in which both the object side surface and the image surface are spherical.

In addition, when the amount of movement of the first lens in the X and Y axes is X and Y, the conditional expression of X < 0.1 mm and Y < 0.1 mm is satisfied.

1.50 <n2 <1.65, 1.50 <n3 <1.65, 1.50 <n4 <1.65, and 1.50 <n1 <1.65, where n1, 1.50 < n5 < 1.65.

The present invention has an effect of correcting resolution degradation of an image due to camera shake of a user by correcting the first lens by moving the resolution.

1 is a block diagram of a camera lens module according to the present invention;
2 is a graph showing aberration diagrams of 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 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 Of the lens.

Here, the first lens 10 may be configured to move in two axes, that is, an X-axis and a Y-axis, so as to correct a shake of a light image of an object incident on the first lens 10.

Therefore, the imaging lens of the present invention has an advantage that the resolution of the image due to the camera shake of the user can be corrected by moving the first lens 10 to correct the resolution.

At this time, the moving distance of the first lens 10 is within ± 0.1 mm in both the X and Y directions.

The focal length of the first lens 10 is relatively longer than that of the second lens 20 to the fifth lens 50.

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 negative or positive refractive power and is movable in two axes of an X axis and a Y axis and has a meniscus shape having both sides convex on the object side surface S1.

The second lens 20 has a positive refractive power and has a meniscus shape having both sides convex on the object side surface S3.

Further, the third lens 30 has a negative refractive power and has a concave shape on both sides.

In addition, the fourth lens 40 has a positive refractive power and a meniscus shape convex upward.

The fifth lens 50 has a negative refractive power and has a meniscus shape convex upward in the optical axis region.

The first lens 10 to the fifth lens 50 are aspherical surfaces in which both the object side surface and the image surface are spherical.

1 'is the upper side of the first lens 10,' S4 'is the upper side of the second lens 20,' S5 'and' S6 'are the upper side of the third lens 30, 'S7' and 'S8' are the object side and upper side of the fourth lens 40, 'S9' and 'S10' are the object side and upper side of the fifth lens 50, 'S11' and 'S12' are the object side and the upper side of the filter 60.

The filter 60 is at least one of an infrared filter, an optical filter such as a cover glass, and the like. When the infrared filter is applied as the filter 60, infrared rays emitted from the external light are 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] 1.50 <n1 <1.65, 1.50 <n2 <1.65, 1.50 <n3 <1.65, 1.50 <n4 <1.65, 1.50 <n5 <1.65

[Conditional expression 2] f1 &gt; 800mm

[Conditional expression 3] X <| 0.1 mm |, Y <| 0.1 mm

Here, n1, n2, n3, n4, and n5: the refractive indexes of the first lens to the fifth lens

f1: Effective focal length of the first lens

X, Y: Movement amount of the first lens moving in the X-axis and Y-axis

Conditional expression 1 defines the refractive index of the first to fifth lenses 10, 20, 30, 40, The first through fifth lenses 10, 20, 30, 40, and 50 have a refractive index with a proper chromatic aberration and correction of appropriate spherical aberration according to the conditional expression (1).

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]

Table 1 below shows an embodiment of the imaging lens of the present invention.

Factor data Factor data Factor data f1 -871.1784 f1 / TTL -163.4519 n1 / TTL 0.2873 f2 3.5870 f2 / TTL 0.6730 n2 / TTL 0.2873 f3 -7.2741 f3 / TTL -1.3648 n1 / TTL 0.3066 f4 3.3291 f4 / TTL 0.6246 n4 / TTL 0.2873 f5 -3.1962 f5 / TTL -0.5997 n5 / TTL 0.2873

Here, TTL is the distance from the first lens to the image plane '5.33 mm'.

The following Table 2 shows a more specific embodiment in comparison with the embodiment of Table 1. [

Face number The radius of curvature (R) Thickness or distance (d) Refractive index (N) OBJ. Infinity Infinity One* 28.75347 0.330 1.53 2* 26.96364 0.104 Stop 1.56818 0.763 1.53 4* 7.36555 0.190 5 * -50.10000 0.345 1.63 6 * 5.09460 0.520 7 * -9.42606 0.901 1.53 8* -1.53844 0.260 9 * 3.36944 0.568 1.53 10 * 1.06297 0.458 11 * Infinity 0.300 1.523 12 * Infinity Image Infinity 0

In Table 2 and Table 3 below, an asterisk (*) next to the surface number indicates an aspherical surface.

Table 3 below shows values of aspherical surface coefficients of the respective lenses in the embodiment of Table 2 above.

if
number k A B C D E F One* 0.000000 0.000000 0.000000 0.000000 0.000000 2* 0.000000 0.000000 0.000000 0.000000 0.000000 3 * -0.886561 0.38212
E-01 E-01 E-01 0.000000 4* 0.000000 -0.374930
E-01 0.000000 0.000000 0.000000 5 * 0.000000 -0.987476
E-01 -0.178474
E-01 0.431209
E-01 0.269395
E-01 -0.468864
E-01 6 * -6.510237 -0.10742
E-02 -0.167956
E-01 0.946027
E-01 -0.560504
E-01 0.221972
E-01 7 * 47.169117 0.500050
E-01 -0.921564
E-01 0.778317
E-01 -0.301769
E-01 0.550097
E-02 8* -0.719022 0.283638
E-01 0.500686
E-01 -0.656807
E-01 0.390135
E-01 -0.746835
E-02 9 * -98.506938 -0.192149
E + 00 0.660919
E-01 -0.629577
E-02 -0.848849
E-03 0.301428
E-03 -0.359279
E-04 10 * -5.850789 -0.884689
E-01 0.309357
E-01 -0.737980
E-02 0.102150
E-02 -0.783655
E-04 0.259534
E-05

FIG. 2 is a graph showing aberration diagrams of 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. 2, the Y axis means the size of the image, and the X side means the focal length (in mm) and the distortion degree (in%). In FIG. 2, as the curves approach the Y-axis, the aberration correction function is considered to be better. In the illustrated aberration diagrams, since the values of the images are adjacent to the Y axis in almost all fields, spherical aberration, astigmatism, and distortion aberration are all excellent values.

That is, since the range of the decentering aberration is -0.029 mm to +0.019 mm, the range of the astigmatism is -0.01 mm to +0.04 mm, and the range of the distortion aberration is -0.00 mm to +0.5 mm, Can correct the characteristics of the spherical aberration, the astigmatism, and the distortion aberration, and it can be seen that it has excellent lens characteristics.

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 (8)

In order from the object side,
A first lens having a negative refractive power and capable of moving in two axes of an X axis and a Y axis;
A second lens having positive refractive power;
A third lens having negative refractive power;
A fourth lens having positive refractive power;
And a fifth lens having negative refractive power,
And an effective focal length of the effective focal length of the first lens is f1,
f1 &gt; 800mm &lt;
The third lens has a concave shape in both the object side and the image side,
Wherein the first lens has a convex meniscus shape toward the object side.
The method according to claim 1,
And the second lens comprises:
Wherein the imaging lens has a convex meniscus shape toward the object side.
The method according to claim 1,
And the fourth lens has a meniscus shape that is convex upward.
The method according to claim 1,
The fifth lens includes:
Wherein the imaging lens has a convex meniscus shape upward.
The method according to claim 1,
Wherein the first lens comprises:
Wherein the imaging lens has a mejerk shape convex to the object side.
The method according to claim 1,
Wherein the first lens and the fifth lens are arranged such that,
Wherein the object side surface and the image side surface are spherical surfaces.
The method according to claim 1,
When the amounts of movement of the first lens in the X and Y axes are X and Y,
X < 0.1 mm, and Y < 0.1 mm |.
The method according to claim 1,
And n1, n2, n3, n4, and n5 denote the refractive indexes of the first lens to the fifth lens,
Wherein 1.50 <n1 <1.65, 1.50 <n2 <1.65, 1.50 <n3 <1.65, 1.50 <n4 <1.65, 1.50 <n5 <1.65.

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