KR20230078466A - Optical imaging system - Google Patents

Abstract

An imaging optical system according to an embodiment of the present invention includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, and an eighth lens sequentially disposed from the object side; Including, the first lens has a positive refractive power, the second lens has a negative refractive power, at least three of the first lens to the eighth lens have a refractive index of 1.61 or more, (TTL / (2 ×IMG HT)) ×(TTL/f) < 0.64 may be satisfied. Here, TTL is the distance on the optical axis from the object-side surface of the first lens to the imaging surface, IMG HT is half of the diagonal length of the imaging surface, and f is the total focal length of the first lens to the eighth lens.

Description

Imaging optical system {Optical imaging system}

The present invention relates to an imaging optical system.

Recent portable terminals are equipped with a camera including an imaging optical system composed of a plurality of lenses to enable video calls and photo taking.

In addition, as the function occupied by a camera in a portable terminal gradually increases, the demand for a camera for a portable terminal having a high resolution is increasing.

In particular, in recent years, an image sensor having high pixels (eg, 13 million to 100 million pixels, etc.) has been employed in a camera for a portable terminal in order to implement a clearer picture quality.

That is, the size of the image sensor is gradually increasing, and accordingly, the total track length of the imaging optical system is also increased, resulting in a problem in that the camera protrudes from the portable terminal.

Since portable terminals are gradually miniaturized and slimmer cameras for portable terminals are required, development of an imaging optical system capable of realizing high resolution while being slim is required.

An object according to an embodiment of the present invention is to provide an imaging optical system capable of implementing high resolution and having a small length of the entire optical system.

An imaging optical system according to an embodiment of the present invention includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, and an eighth lens sequentially disposed from the object side; Including, the first lens has a positive refractive power, the second lens has a negative refractive power, at least three of the first lens to the eighth lens have a refractive index of 1.61 or more, (TTL / (2 ×IMG HT)) ×(TTL/f) < 0.64 may be satisfied. Here, TTL is the distance on the optical axis from the object-side surface of the first lens to the imaging surface, IMG HT is half of the diagonal length of the imaging surface, and f is the total focal length of the first lens to the eighth lens.

According to the imaging optical system according to an embodiment of the present invention, the size can be reduced while implementing high resolution.

1 is a configuration diagram of an imaging optical system according to a first embodiment of the present invention.
FIG. 2 is a diagram showing aberration characteristics of the imaging optical system shown in FIG. 1 .
3 is a configuration diagram of an imaging optical system according to a second embodiment of the present invention.
FIG. 4 is a diagram showing aberration characteristics of the imaging optical system shown in FIG. 3 .
5 is a configuration diagram of an imaging optical system according to a third embodiment of the present invention.
6 is a diagram showing aberration characteristics of the imaging optical system shown in FIG. 5;
7 is a configuration diagram of an imaging optical system according to a fourth embodiment of the present invention.
FIG. 8 is a diagram showing aberration characteristics of the imaging optical system shown in FIG. 7 .
9 is a configuration diagram of an imaging optical system according to a fifth embodiment of the present invention.
FIG. 10 is a diagram showing aberration characteristics of the imaging optical system shown in FIG. 9 .
11 is a configuration diagram of an imaging optical system according to a sixth embodiment of the present invention.
FIG. 12 is a diagram showing aberration characteristics of the imaging optical system shown in FIG. 11;
13 is a configuration diagram of an imaging optical system according to a seventh embodiment of the present invention.
14 is a diagram showing aberration characteristics of the imaging optical system shown in FIG. 13;
15 is a configuration diagram of an imaging optical system according to an eighth embodiment of the present invention.
16 is a diagram showing aberration characteristics of the imaging optical system shown in FIG. 15;
17 is a configuration diagram of an imaging optical system according to a ninth embodiment of the present invention.
18 is a diagram showing aberration characteristics of the imaging optical system shown in FIG. 17;
19 is a configuration diagram of an imaging optical system according to a tenth embodiment of the present invention.
20 is a diagram showing aberration characteristics of the imaging optical system shown in FIG. 19;

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, the spirit of the present invention is not limited to the presented examples.

For example, those skilled in the art who understand the spirit of the present invention may easily suggest other embodiments included in the scope of the spirit of the present invention by adding, changing, or deleting components, but this is also the spirit of the present invention. will be said to be within the scope of

In addition, throughout the specification, 'including' a certain element means that other elements may be further included, rather than excluding other elements unless otherwise stated.

In the following lens configuration diagram, the thickness, size, and shape of the lens are somewhat exaggerated for description, and in particular, the spherical or aspherical shape presented in the lens configuration diagram is only presented as an example and is not limited thereto.

The first lens means a lens closest to the object side, and the eighth lens means a lens closest to the imaging plane (or image sensor).

Further, in each lens, the first surface means a surface close to the object side (or object-side surface), and the second surface means a surface close to the image side (or image side surface). In addition, in this specification, the values for the radius of curvature, thickness, distance, and focal length of the lens are all units of mm, and the unit of the angle of view (FOV) is degree.

In addition, in the description of the shape of each lens, the meaning that one side is convex means that the paraxial region portion of the corresponding side is convex, and the meaning that one side is concave means that the paraxial region portion of the corresponding side is concave. The plane means that the paraxial region portion of the plane is plane. Therefore, even if one surface of the lens is described as having a convex shape, the edge portion of the lens may be concave. Likewise, even if one surface of the lens is described as having a concave shape, the edge portion of the lens may be convex. Also, even if one surface of the lens is described as being flat, an edge portion of the lens may be convex or concave.

Meanwhile, the paraxial region means a very narrow region near an optical axis.

The imaging plane may refer to a virtual plane on which a focus is formed by an imaging optical system. Alternatively, the imaging surface may refer to one surface of an image sensor through which light is received.

An imaging optical system according to an embodiment of the present invention includes 8 lenses.

For example, an imaging optical system according to an embodiment of the present invention includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, and An eighth lens is included. The first to eighth lenses are spaced apart from each other by a predetermined distance along the optical axis.

However, the imaging optical system according to an embodiment of the present invention is not composed of only 8 lenses and may further include other components as needed.

For example, the imaging optical system may further include an image sensor for converting an incident image of a subject into an electrical signal.

In addition, the imaging optical system may further include an infrared filter (hereinafter referred to as 'filter') for blocking infrared rays. A filter is disposed between the eighth lens and the image sensor.

In addition, the imaging optical system may further include a diaphragm for adjusting the amount of light.

The first to eighth lenses constituting the imaging optical system according to an embodiment of the present invention may be made of a plastic material.

In addition, at least one of the first to eighth lenses has an aspheric surface. Also, each of the first to eighth lenses may have at least one aspherical surface.

That is, at least one of the first and second surfaces of the first to eighth lenses may be an aspherical surface. Here, the aspheric surfaces of the first to eighth lenses are expressed by Equation 1.

In Equation 1, c is the curvature of the lens (the reciprocal of the radius of curvature), K is the conic constant, and Y represents the distance from an arbitrary point on the aspheric surface of the lens to the optical axis. In addition, the constants A to P mean aspherical surface coefficients. And Z represents the distance from an arbitrary point on the aspheric surface of the lens to the apex of the aspherical surface.

An imaging optical system according to an embodiment of the present invention may satisfy at least one of the following conditional expressions.

[Conditional Expression 1] 0 < f1/f < 1.4

[Conditional expression 2] 25 < v1-v2 < 40

[Conditional expression 3] 15 < v1-v4 < 40

[Conditional Expression 4] 15 < v1-(v6+v7)/2 < 30

[Conditional Expression 5] -3 < f2/f < 0

[Conditional Expression 6] 1 < f3/f < 6

[Conditional Expression 7] 0 < f7/(10×f) < 5

[Conditional Expression 8] -3 < f8/f < 0

[Conditional Expression 9] BFL/f < 0.3

[Conditional Expression 10] 70° < FOV×(IMG HT/f) < 100°

[Conditional Expression 11] -0.2 < SAG52/TTL < 0

[Conditional Expression 12] -0.2 < SAG62/TTL < 0

[Conditional Expression 13] -0.3 < SAG72/TTL < 0

[Conditional Expression 14] -0.3 < SAG82/TTL < 0

[Conditional Expression 15] 5 < |Y72/Z72| < 100

[Conditional Expression 16] 5 < |Y82/Z82| < 30

[Conditional Expression 17] (TTL/(2×IMG HT))×(TTL/f) < 0.64

In the conditional expressions, f is the total focal length of the imaging optical system, f1 is the focal length of the first lens, f2 is the focal length of the second lens, f3 is the focal length of the third lens, and f7 is the focal length of the seventh lens distance, and f8 is the focal length of the eighth lens.

v1 is the Abbe number of the first lens, v2 is the Abbe number of the second lens, v4 is the Abbe number of the fourth lens, v6 is the Abbe number of the sixth lens, and v7 is the Abbe number of the seventh lens.

TTL is the distance on the optical axis from the object-side surface of the first lens to the imaging surface, and BFL is the distance on the optical axis from the image-side surface of the eighth lens to the imaging surface.

IMG HT is half of the diagonal length of the imaging surface, and FOV is the angle of view of the imaging optical system.

SAG52 is the SAG value at the tip of the effective mirror on the image side of the fifth lens, SAG62 is the SAG value at the tip of the effective mirror on the image side of the sixth lens, SAG72 is the SAG value at the tip of the effective mirror on the image side of the seventh lens, , SAG82 is the SAG value at the tip of the effective mirror of the image side surface of the eighth lens.

If the SAG value has a negative value, it means that the tip of the effective mirror of the corresponding lens surface is located closer to the object side than the apex of the corresponding lens surface.

When the SAG value has a positive value, it means that the tip of the effective mirror of the corresponding lens surface is located closer to the upper side than the apex of the corresponding lens surface.

Y72 is the vertical height between the optical axis and the first inflection point on the image side of the seventh lens, and Y82 is the vertical height between the optical axis and the first inflection point on the image side of the eighth lens.

Z72 is the Sag value at the first inflection point on the image side of the seventh lens, and Z82 is the Sag value at the first inflection point on the image side of the eighth lens.

First to eighth lenses constituting an imaging optical system according to an embodiment of the present invention will be described.

The first lens has a positive refractive power. In addition, the first lens may have a meniscus shape convex toward the object side. In other words, the first surface of the first lens may be convex, and the second surface of the first lens may be concave.

At least one of the first surface and the second surface of the first lens may be an aspherical surface. For example, both surfaces of the first lens may be aspherical.

The second lens has negative refractive power. In addition, the second lens may have a meniscus shape convex toward the object side. In other words, the first surface of the second lens may be convex, and the second surface of the second lens may be concave.

At least one surface of the first surface and the second surface of the second lens may be an aspheric surface. For example, both surfaces of the second lens may be aspherical.

The third lens has positive refractive power. In addition, the third lens may have a meniscus shape convex toward the object side. In other words, the first surface of the third lens may be convex, and the second surface of the third lens may be concave.

At least one surface of the first surface and the second surface of the third lens may be aspheric. For example, both surfaces of the third lens may be aspherical.

The fourth lens has positive refractive power. In addition, the fourth lens may have a meniscus shape convex toward the object side. In other words, the first surface of the fourth lens may be convex, and the second surface of the fourth lens may be concave.

Alternatively, the fourth lens may have a convex shape on both sides. In other words, the first and second surfaces of the fourth lens may have convex shapes.

At least one surface of the first surface and the second surface of the fourth lens may be an aspheric surface. For example, both surfaces of the fourth lens may be aspherical.

The fifth lens has negative refractive power. In addition, the fifth lens may have a meniscus shape convex toward the object side. In other words, the first surface of the fifth lens may be convex in the paraxial region, and the second surface of the fifth lens may be concave in the paraxial region.

Alternatively, the fifth lens may have a meniscus shape convex upward. In other words, the first surface of the fifth lens may be concave, and the second surface of the fifth lens may be convex.

At least one surface of the first surface and the second surface of the fifth lens may be aspheric. For example, both surfaces of the fifth lens may be aspheric.

The sixth lens has positive or negative refractive power. In addition, the sixth lens may have a meniscus shape convex toward the object side. In other words, the first surface of the sixth lens may be convex in the paraxial region, and the second surface of the sixth lens may be concave in the paraxial region.

At least one surface of the first surface and the second surface of the sixth lens may be an aspherical surface. For example, both surfaces of the sixth lens may be aspherical.

At least one inflection point may be formed on at least one of the first surface and the second surface of the sixth lens. For example, the first surface of the sixth lens may be convex in the paraxial region and concave in parts other than the paraxial region. The second surface of the sixth lens may be concave in the paraxial region and convex in parts other than the paraxial region.

The seventh lens has positive refractive power. In addition, the seventh lens may have a meniscus shape convex toward the object side. In other words, the first surface of the seventh lens may be convex in the paraxial region, and the second surface of the seventh lens may be concave in the paraxial region.

Alternatively, the seventh lens may have a convex shape on both sides. In other words, the first and second surfaces of the seventh lens may have convex shapes.

At least one surface of the first surface and the second surface of the seventh lens may be an aspheric surface. For example, both surfaces of the seventh lens may be aspherical.

In addition, at least one inflection point may be formed on at least one of the first surface and the second surface of the seventh lens. For example, the first surface of the seventh lens may be convex in the paraxial region and concave in portions other than the paraxial region. The second surface of the seventh lens may be convex in the paraxial region and concave in a portion other than the paraxial region.

The eighth lens has negative refractive power. In addition, the eighth lens may have a meniscus shape convex toward the object side. In other words, the first surface of the eighth lens may be convex in the paraxial region, and the second surface of the eighth lens may be concave in the paraxial region.

Alternatively, the eighth lens may have a concave shape on both sides. In other words, the first and second surfaces of the eighth lens may have concave shapes.

At least one surface of the first surface and the second surface of the eighth lens may be an aspheric surface. For example, both surfaces of the eighth lens may be aspheric.

In addition, at least one inflection point may be formed on at least one of the first surface and the second surface of the eighth lens. For example, the first surface of the eighth lens may be convex in the paraxial region and concave in parts other than the paraxial region. The second surface of the eighth lens may be concave in the paraxial region and convex in parts other than the paraxial region.

Each of the first to eighth lenses may be formed of a plastic material having optical characteristics different from those of adjacent lenses.

Meanwhile, at least three of the first to eighth lenses may have a refractive index greater than 1.61. For example, the second lens, the fifth lens, and the sixth lens may have a refractive index greater than 1.61. Alternatively, the refractive index of the second lens, the fourth lens, and the sixth lens may be greater than 1.61.

An imaging optical system 100 according to a first embodiment of the present invention will be described with reference to FIGS. 1 and 2 .

The imaging optical system 100 according to the first embodiment of the present invention includes a first lens 110, a second lens 120, a third lens 130, a fourth lens 140, a fifth lens 150, It includes an optical system including the sixth lens 160, the seventh lens 170, and the eighth lens 180, and may further include a filter 190 and an image sensor IS.

The imaging optical system 100 according to the first embodiment of the present invention may form a focus on the imaging surface 191 . The imaging surface 191 may refer to a surface on which a focus is formed by an imaging optical system. For example, the imaging surface 191 may refer to one surface of the image sensor IS through which light is received.

Table 1 shows the lens characteristics of each lens (radius of curvature, thickness of the lens or distance between the lenses, index of refraction, Abbe number, focal length).

side number note radius of curvature thickness or distance refractive index Abe number focal length S1 1st lens 2.569 0.787 1.544 56.0 7.09 S2 6.791 0.025 S3 2nd lens 5.789 0.220 1.680 18.2 -16.44 S4 3.772 0.167 S5 3rd lens 4.858 0.562 1.535 55.7 17.92 S6 9.410 0.251 S7 4th lens 19.735 0.250 1.567 37.4 372.07 S8 21.657 0.512 S9 5th lens 52.749 0.321 1.680 18.2 -37.18 S10 17.204 0.487 S11 6th lens 18.041 0.340 1.635 24.0 263.04 S12 20.054 0.580 S13 7th lens 4.823 0.477 1.567 37.4 15.86 S14 9.955 1.202 S15 8th lens 10.211 0.477 1.544 56.0 -5.51 S16 2.285 0.302 S17 filter Infinity 0.110 1.517 64.2 S18 Infinity 0.770 S19 imaging plane Infinity

Meanwhile, the total focal length f of the imaging optical system 100 according to the first embodiment of the present invention is 7.46 mm, IMG HT is 7.145 mm, FOV is 85.4 °, SAG52 is -0.399 mm, and SAG62 is -0.896 mm, SAG72 is -1.473 mm, and SAG82 is -1.750 mm.

In the first embodiment of the present invention, the first lens 110 has positive refractive power, the first surface of the first lens 110 has a convex shape, and the second surface of the first lens 110 has a concave shape. .

The second lens 120 has negative refractive power, the first surface of the second lens 120 is convex, and the second surface of the second lens 120 is concave.

The third lens 130 has positive refractive power, the first surface of the third lens 130 is convex, and the second surface of the third lens 130 is concave.

The fourth lens 140 has positive refractive power, a first surface of the fourth lens 140 is convex, and a second surface of the fourth lens 140 is concave.

The fifth lens 150 has negative refractive power, the first surface of the fifth lens 150 is convex, and the second surface of the fifth lens 150 is concave.

The sixth lens 160 has positive refractive power, a first surface of the sixth lens 160 is convex in the paraxial region, and a second surface of the sixth lens 160 is concave in the paraxial region.

In addition, at least one inflection point is formed on at least one of the first surface and the second surface of the sixth lens 160 . For example, the first surface of the sixth lens 160 may be convex in the paraxial region and concave in parts other than the paraxial region. Also, the second surface of the sixth lens 160 may be concave in the paraxial region and convex in parts other than the paraxial region.

The seventh lens 170 has positive refractive power, a first surface of the seventh lens 170 is convex, and a second surface of the seventh lens 170 is concave.

In addition, at least one inflection point is formed on at least one of the first and second surfaces of the seventh lens 170 . For example, the first surface of the seventh lens 170 may be convex in the paraxial region and concave in parts other than the paraxial region. Also, the second surface of the seventh lens 170 may be concave in the paraxial region and convex in parts other than the paraxial region.

The eighth lens 180 has negative refractive power, a first surface of the eighth lens 180 is convex in the paraxial region, and a second surface of the eighth lens 180 is concave in the paraxial region.

In addition, at least one inflection point is formed on at least one of the first and second surfaces of the eighth lens 180 . For example, the first surface of the eighth lens 180 may be convex in the paraxial region and concave in parts other than the paraxial region. Also, the second surface of the eighth lens 180 may be concave in the paraxial region and convex in parts other than the paraxial region.

Meanwhile, each surface of the first lens 110 to the eighth lens 180 has an aspherical surface coefficient as shown in Table 2. For example, both the object-side surface and the image-side surface of the first lens 110 to the eighth lens 180 are aspheric surfaces.

S1 S2 S3 S4 S5 S6 S7 S8 Conic constant (K) -1.385 10.590 -10.876 -4.272 0.417 -8.163 -57.077 -51.784 4th order coefficient (A) 5.851E-02 6.883E-02 2.584E-02 1.172E-02 -2.280E-02 -2.888E-02 -1.086E-02 -2.414E-02 6th order coefficient (B) -4.243E-01 -5.432E-01 -1.737E-01 7.702E-02 2.323E-01 1.083E-01 -7.230E-02 -1.928E-01 8th order coefficient (C) 1.643E+00 1.898E+00 5.327E-01 -6.617E-01 -1.154E+00 -3.260E-01 3.430E-01 1.770E+00 Tenth order coefficient (D) -3.720E+00 -3.851E+00 -8.263E-01 2.233E+00 3.293E+00 6.649E-01 -1.036E+00 -7.188E+00 12th order coefficient (E) 5.475E+00 5.052E+00 6.181E-01 -4.462E+00 -6.055E+00 -9.328E-01 2.180E+00 1.752E+01 14th order coefficient (F) -5.538E+00 -4.560E+00 -2.351E-02 5.896E+00 7.634E+00 9.292E-01 -3.240E+00 -2.821E+01 16th order coefficient (G) 3.976E+00 2.935E+00 -3.984E-01 -5.410E+00 -6.818E+00 -6.622E-01 3.460E+00 3.148E+01 18th order coefficient (H) -2.058E+00 -1.371E+00 4.106E-01 3.531E+00 4.387E+00 3.327E-01 -2.682E+00 -2.491E+01 20th order coefficient (J) 7.709E-01 4.676E-01 -2.266E-01 -1.652E+00 -2.041E+00 -1.116E-01 1.510E+00 1.408E+01 22nd Coefficient (L) -2.071E-01 -1.155E-01 7.958E-02 5.503E-01 6.806E-01 2.091E-02 -6.119E-01 -5.650E+00 24th order coefficient (M) 3.888E-02 2.015E-02 -1.833E-02 -1.275E-01 -1.585E-01 -1.730E-04 1.737E-01 1.570E+00 26th Coefficient (N) -4.844E-03 -2.363E-03 2.692E-03 1.952E-02 2.448E-02 -9.184E-04 -3.281E-02 -2.873E-01 28th order coefficient (O) 3.598E-04 1.677E-04 -2.294E-04 -1.775E-03 -2.252E-03 1.998E-04 3.700E-03 3.107E-02 30th order coefficient (P) -1.205E-05 -5.468E-06 8.647E-06 7.263E-05 9.335E-05 -1.461E-05 -1.884E-04 -1.504E-03 S9 S10 S11 S12 S13 S14 S15 S16 Conic constant (K) 99.000 -16.070 -99.000 -27.356 1.180 -1.687 0.203 -13.875 4th order coefficient (A) -8.324E-02 -7.458E-02 -6.552E-02 -7.397E-02 -6.641E-02 -3.768E-02 -1.600E-01 -6.932E-02 6th order coefficient (B) 5.047E-01 2.371E-01 1.110E-01 5.267E-02 1.657E-02 1.836E-03 7.913E-02 2.770E-02 8th order coefficient (C) -2.750E+00 -8.973E-01 -2.847E-01 -2.526E-02 1.451E-02 1.443E-02 -2.862E-02 -7.877E-03 Tenth order coefficient (D) 9.016E+00 2.213E+00 5.482E-01 -2.997E-02 -4.215E-02 -2.062E-02 7.391E-03 1.611E-03 12th order coefficient (E) -1.939E+01 -3.671E+00 -7.581E-01 7.328E-02 4.336E-02 1.482E-02 -1.343E-03 -2.376E-04 14th order coefficient (F) 2.880E+01 4.237E+00 7.525E-01 -7.312E-02 -2.656E-02 -6.730E-03 1.739E-04 2.524E-05 16th order coefficient (G) -3.040E+01 -3.478E+00 -5.394E-01 4.478E-02 1.084E-02 2.088E-03 -1.631E-05 -1.919E-06 18th order coefficient (H) 2.315E+01 2.055E+00 2.798E-01 -1.846E-02 -3.072E-03 -4.572E-04 1.117E-06 1.022E-07 20th order coefficient (J) -1.277E+01 -8.751E-01 -1.047E-01 5.285E-03 6.125E-04 7.134E-05 -5.586E-08 -3.629E-09 22nd Coefficient (L) 5.050E+00 2.658E-01 2.786E-02 -1.054E-03 -8.557E-05 -7.876E-06 2.016E-09 7.485E-11 24th order coefficient (M) -1.396E+00 -5.608E-02 -5.131E-03 1.436E-04 8.188E-06 5.999E-07 -5.111E-11 -3.939E-13 26th Coefficient (N) 2.562E-01 7.805E-03 6.201E-04 -1.276E-05 -5.106E-07 -2.995E-08 8.631E-13 -2.003E-14 28th order coefficient (O) -2.804E-02 -6.434E-04 -4.415E-05 6.656E-07 1.869E-08 8.811E-10 -8.717E-15 4.816E-16 30th order coefficient (P) 1.385E-03 2.377E-05 1.401E-06 -1.546E-08 -3.043E-10 -1.156E-11 3.982E-17 -3.499E-18

In addition, the imaging optical system configured as described above may have aberration characteristics shown in FIG. 2 .

An imaging optical system 200 according to a second embodiment of the present invention will be described with reference to FIGS. 3 and 4 .

An imaging optical system 200 according to a second embodiment of the present invention includes a first lens 210, a second lens 220, a third lens 230, a fourth lens 240, a fifth lens 250, It includes an optical system including a sixth lens 260, a seventh lens 270, and an eighth lens 280, and may further include a filter 290 and an image sensor IS.

The imaging optical system 200 according to the second embodiment of the present invention may form a focus on the imaging surface 291 . The imaging surface 291 may refer to a surface on which a focus is formed by an imaging optical system. For example, the imaging surface 291 may refer to one surface of the image sensor IS through which light is received.

Table 3 shows the lens characteristics of each lens (radius of curvature, thickness of the lens or distance between lenses, index of refraction, Abbe number, focal length).

side number note radius of curvature thickness or distance refractive index Abe number focal length S1 1st lens 2.565 0.780 1.544 56.0 7.1 S2 6.769 0.025 S3 2nd lens 5.379 0.220 1.680 18.2 -17.64 S4 3.667 0.165 S5 3rd lens 4.913 0.556 1.535 55.7 18.01 S6 9.586 0.253 S7 4th lens 23.383 0.250 1.567 37.4 439.35 S8 25.688 0.499 S9 5th lens 82.493 0.324 1.680 18.2 -27.31 S10 15.298 0.473 S11 6th lens 16.814 0.340 1.635 24.0 122.74 S12 21.214 0.617 S13 7th lens 4.800 0.492 1.567 37.4 16.07 S14 9.698 1.166 S15 8th lens 10.313 0.501 1.544 56.0 -5.8 S16 2.383 0.299 S17 filter Infinity 0.110 1.517 64.2 S18 Infinity 0.770 S19 imaging plane Infinity

Meanwhile, the total focal length f of the imaging optical system 200 according to the second embodiment of the present invention is 7.43 mm, IMG HT is 7.145 mm, FOV is 85.6 °, SAG52 is -0.464 mm, and SAG62 is -0.936 mm, SAG72 is -1.547 mm, and SAG82 is -1.750 mm.

In the second embodiment of the present invention, the first lens 210 has a positive refractive power, the first surface of the first lens 210 is convex, and the second surface of the first lens 210 is concave. .

The second lens 220 has negative refractive power, the first surface of the second lens 220 is convex, and the second surface of the second lens 220 is concave.

The third lens 230 has positive refractive power, a first surface of the third lens 230 is convex, and a second surface of the third lens 230 is concave.

The fourth lens 240 has positive refractive power, a first surface of the fourth lens 240 is convex, and a second surface of the fourth lens 240 is concave.

The fifth lens 250 has negative refractive power, a first surface of the fifth lens 250 is convex, and a second surface of the fifth lens 250 is concave.

The sixth lens 260 has positive refractive power, a first surface of the sixth lens 260 is convex in the paraxial region, and a second surface of the sixth lens 260 is concave in the paraxial region.

In addition, at least one inflection point is formed on at least one of the first surface and the second surface of the sixth lens 260 . For example, the first surface of the sixth lens 260 may be convex in the paraxial region and concave in parts other than the paraxial region. Also, the second surface of the sixth lens 260 may be concave in the paraxial region and convex in parts other than the paraxial region.

The seventh lens 270 has positive refractive power, a first surface of the seventh lens 270 is convex, and a second surface of the seventh lens 270 is concave.

In addition, at least one inflection point is formed on at least one of the first and second surfaces of the seventh lens 270 . For example, the first surface of the seventh lens 270 may be convex in the paraxial region and concave in parts other than the paraxial region. The second surface of the seventh lens 270 may be concave in the paraxial region and convex in parts other than the paraxial region.

The eighth lens 280 has negative refractive power, a first surface of the eighth lens 280 is convex in the paraxial region, and a second surface of the eighth lens 280 is concave in the paraxial region.

In addition, at least one inflection point is formed on at least one of the first and second surfaces of the eighth lens 280 . For example, the first surface of the eighth lens 280 may be convex in the paraxial region and concave in parts other than the paraxial region. The second surface of the eighth lens 280 may be concave in the paraxial region and convex in parts other than the paraxial region.

Meanwhile, each surface of the first lens 210 to the eighth lens 280 has an aspherical surface coefficient as shown in Table 4. For example, both the object-side surface and the image-side surface of the first lens 210 to the eighth lens 280 are aspheric surfaces.

S1 S2 S3 S4 S5 S6 S7 S8 Conic constant (K) -1.387 10.587 -11.112 -4.254 0.417 -8.321 -31.832 -99.000 4th order coefficient (A) 4.221E-02 6.594E-02 6.826E-03 1.747E-02 -2.503E-02 -3.581E-02 -7.228E-03 -5.515E-02 6th order coefficient (B) -2.770E-01 -5.057E-01 -1.251E-01 -1.310E-01 1.612E-01 1.952E-01 -8.709E-02 2.588E-01 8th order coefficient (C) 1.039E+00 1.828E+00 5.442E-01 4.690E-01 -6.958E-01 -7.817E-01 3.711E-01 -1.014E+00 Tenth order coefficient (D) -2.281E+00 -3.983E+00 -1.174E+00 -8.960E-01 1.961E+00 2.064E+00 -1.071E+00 2.600E+00 12th order coefficient (E) 3.262E+00 5.793E+00 1.589E+00 1.006E+00 -3.690E+00 -3.726E+00 2.213E+00 -4.609E+00 14th order coefficient (F) -3.219E+00 -5.949E+00 -1.503E+00 -6.391E-01 4.818E+00 4.766E+00 -3.272E+00 5.964E+00 16th order coefficient (G) 2.262E+00 4.438E+00 1.049E+00 1.338E-01 -4.478E+00 -4.410E+00 3.493E+00 -5.830E+00 18th order coefficient (H) -1.151E+00 -2.434E+00 -5.524E-01 1.352E-01 3.006E+00 2.976E+00 -2.712E+00 4.373E+00 20th order coefficient (J) 4.253E-01 9.794E-01 2.197E-01 -1.451E-01 -1.461E+00 -1.463E+00 1.532E+00 -2.508E+00 22nd Coefficient (L) -1.131E-01 -2.855E-01 -6.475E-02 7.051E-02 5.093E-01 5.167E-01 -6.230E-01 1.077E+00 24th order coefficient (M) 2.107E-02 5.856E-02 1.364E-02 -2.064E-02 -1.241E-01 -1.273E-01 1.776E-01 -3.329E-01 26th Coefficient (N) -2.613E-03 -8.004E-03 -1.933E-03 3.731E-03 2.006E-02 2.072E-02 -3.370E-02 6.960E-02 28th order coefficient (O) 1.937E-04 6.538E-04 1.643E-04 -3.854E-04 -1.932E-03 -1.993E-03 3.820E-03 -8.764E-03 30th order coefficient (P) -6.492E-06 -2.412E-05 -6.304E-06 1.750E-05 8.386E-05 8.551E-05 -1.957E-04 5.003E-04 S9 S10 S11 S12 S13 S14 S15 S16 Conic constant (K) 99.000 -31.896 -99.000 -5.551 1.139 -1.563 -0.003 -12.855 4th order coefficient (A) -3.267E-02 -1.244E-01 -8.547E-02 -7.443E-02 -8.655E-02 -4.982E-02 -1.641E-01 -8.139E-02 6th order coefficient (B) 2.705E-02 5.244E-01 2.460E-01 2.695E-02 7.363E-02 1.835E-02 9.402E-02 4.215E-02 8th order coefficient (C) -4.764E-01 -1.825E+00 -7.978E-01 7.136E-02 -8.519E-02 1.658E-03 -3.756E-02 -1.426E-02 Tenth order coefficient (D) 2.468E+00 4.099E+00 1.730E+00 -1.951E-01 7.239E-02 -1.274E-02 1.004E-02 3.212E-03 12th order coefficient (E) -6.969E+00 -6.245E+00 -2.507E+00 2.455E-01 -4.400E-02 1.081E-02 -1.825E-03 -5.005E-04 14th order coefficient (F) 1.250E+01 6.688E+00 2.502E+00 -1.938E-01 1.898E-02 -5.178E-03 2.328E-04 5.545E-05 16th order coefficient (G) -1.521E+01 -5.147E+00 -1.764E+00 1.041E-01 -5.825E-03 1.649E-03 -2.138E-05 -4.430E-06 18th order coefficient (H) 1.296E+01 2.876E+00 8.907E-01 -3.934E-02 1.276E-03 -3.679E-04 1.430E-06 2.559E-07 20th order coefficient (J) -7.832E+00 -1.168E+00 -3.230E-01 1.058E-02 -1.995E-04 5.833E-05 -6.986E-08 -1.059E-08 22nd Coefficient (L) 3.345E+00 3.403E-01 8.332E-02 -2.011E-03 2.207E-05 -6.539E-06 2.465E-09 3.062E-10 24th order coefficient (M) -9.880E-01 -6.930E-02 -1.490E-02 2.641E-04 -1.692E-06 5.059E-07 -6.121E-11 -5.914E-12 26th Coefficient (N) 1.920E-01 9.352E-03 1.754E-03 -2.277E-05 8.575E-08 -2.566E-08 1.014E-12 6.980E-14 28th order coefficient (O) -2.209E-02 -7.506E-04 -1.221E-04 1.159E-06 -2.592E-09 7.671E-10 -1.007E-14 -4.138E-16 30th order coefficient (P) 1.140E-03 2.710E-05 3.799E-06 -2.638E-08 3.550E-11 -1.023E-11 4.530E-17 6.262E-19

Also, the imaging optical system configured as described above may have aberration characteristics shown in FIG. 4 .

An imaging optical system 300 according to a third embodiment of the present invention will be described with reference to FIGS. 5 and 6 .

An imaging optical system 300 according to a third embodiment of the present invention includes a first lens 310, a second lens 320, a third lens 330, a fourth lens 340, a fifth lens 350, It includes an optical system including a sixth lens 360, a seventh lens 370, and an eighth lens 380, and may further include a filter 390 and an image sensor IS.

The imaging optical system 300 according to the third embodiment of the present invention may form a focus on the imaging surface 391 . The imaging surface 391 may mean a surface on which a focus is formed by an imaging optical system. For example, the imaging surface 391 may refer to one surface of the image sensor IS through which light is received.

The lens characteristics of each lens (radius of curvature, thickness of the lens or distance between lenses, index of refraction, Abbe number, focal length) are shown in Table 5.

side number note radius of curvature thickness or distance refractive index Abe number focal length S1 1st lens 2.566 0.827 1.544 56.0 7.07 S2 6.783 0.025 S3 2nd lens 4.797 0.220 1.680 18.2 -15.68 S4 3.260 0.186 S5 3rd lens 5.257 0.538 1.535 55.7 17.12 S6 11.835 0.248 S7 4th lens 36.796 0.250 1.567 37.4 182.29 S8 56.791 0.478 S9 5th lens 204.930 0.336 1.680 18.2 -38.42 S10 23.431 0.460 S11 6th lens 21.471 0.340 1.635 24.0 -648.94 S12 20.291 0.552 S13 7th lens 4.816 0.467 1.567 37.4 15.1 S14 10.530 1.276 S15 8th lens 10.655 0.525 1.544 56.0 -5.19 S16 2.201 0.231 S17 filter Infinity 0.110 1.517 64.2 S18 Infinity 0.770 S19 imaging plane Infinity

Meanwhile, the total focal length f of the imaging optical system 300 according to the third embodiment of the present invention is 7.41 mm, IMG HT is 7.145 mm, FOV is 85.8 °, SAG52 is -0.484 mm, and SAG62 is -0.925 mm, SAG72 is -1.469 mm, and SAG82 is -1.839 mm.

In the third embodiment of the present invention, the first lens 310 has positive refractive power, the first surface of the first lens 310 is convex, and the second surface of the first lens 310 is concave. .

The second lens 320 has negative refractive power, the first surface of the second lens 320 is convex, and the second surface of the second lens 320 is concave.

The third lens 330 has positive refractive power, a first surface of the third lens 330 is convex, and a second surface of the third lens 330 is concave.

The fourth lens 340 has a positive refractive power, a first surface of the fourth lens 340 is convex, and a second surface of the fourth lens 340 is concave.

The fifth lens 350 has negative refractive power, a first surface of the fifth lens 350 is convex, and a second surface of the fifth lens 350 is concave.

The sixth lens 360 has negative refractive power, a first surface of the sixth lens 360 is convex, and a second surface of the sixth lens 360 is concave in the paraxial region.

In addition, at least one inflection point is formed on at least one of the first surface and the second surface of the sixth lens 360 . For example, the first surface of the sixth lens 360 may be convex in the paraxial region and concave in parts other than the paraxial region. The second surface of the sixth lens 360 may be concave in the paraxial region and convex in parts other than the paraxial region.

The seventh lens 370 has a positive refractive power, a first surface of the seventh lens 370 is convex, and a second surface of the seventh lens 370 is concave.

In addition, at least one inflection point is formed on at least one of the first and second surfaces of the seventh lens 370 . For example, the first surface of the seventh lens 370 may be convex in the paraxial region and concave in parts other than the paraxial region. The second surface of the seventh lens 370 may be concave in the paraxial region and convex in parts other than the paraxial region.

The eighth lens 380 has negative refractive power, the first surface of the eighth lens 380 is convex, and the second surface of the eighth lens 380 is concave.

In addition, at least one inflection point is formed on at least one of the first and second surfaces of the eighth lens 380 . For example, the first surface of the eighth lens 380 may be convex in the paraxial region and concave in parts other than the paraxial region. The second surface of the eighth lens 380 may be concave in the paraxial region and convex in parts other than the paraxial region.

Meanwhile, each surface of the first lens 310 to the eighth lens 380 has an aspherical surface coefficient as shown in Table 6. For example, both the object-side surface and the image-side surface of the first lens 310 to the eighth lens 380 are aspheric surfaces.

S1 S2 S3 S4 S5 S6 S7 S8 Conic constant (K) -1.288 10.570 -11.037 -4.305 0.405 -7.916 58.220 23.748 4th order coefficient (A) 9.266E-03 5.296E-03 3.368E-03 -2.282E-03 -3.014E-03 -1.278E-02 -1.360E-02 -2.612E-02 6th order coefficient (B) -4.772E-03 -1.532E-02 1.487E-02 1.331E-02 -4.251E-03 2.758E-02 -6.621E-02 6.579E-02 8th order coefficient (C) 1.890E-02 1.848E-02 -7.623E-02 -1.948E-02 5.253E-02 -7.613E-02 3.454E-01 -2.855E-01 Tenth order coefficient (D) -4.189E-02 -1.988E-02 1.975E-01 -5.069E-03 -2.155E-01 1.219E-01 -1.069E+00 8.597E-01 12th order coefficient (E) 5.915E-02 1.869E-02 -3.290E-01 1.076E-01 5.646E-01 -4.919E-02 2.247E+00 -1.767E+00 14th order coefficient (F) -5.666E-02 -1.933E-02 3.747E-01 -2.644E-01 -9.771E-01 -1.831E-01 -3.327E+00 2.582E+00 16th order coefficient (G) 3.807E-02 2.133E-02 -3.001E-01 3.604E-01 1.159E+00 4.231E-01 3.546E+00 -2.742E+00 18th order coefficient (H) -1.823E-02 -1.869E-02 1.717E-01 -3.191E-01 -9.649E-01 -4.757E-01 -2.753E+00 2.140E+00 20th order coefficient (J) 6.231E-03 1.133E-02 -7.039E-02 1.929E-01 5.685E-01 3.380E-01 1.557E+00 -1.228E+00 22nd Coefficient (L) -1.503E-03 -4.608E-03 2.053E-02 -8.054E-02 -2.360E-01 -1.607E-01 -6.348E-01 5.125E-01 24th order coefficient (M) 2.480E-04 1.234E-03 -4.162E-03 2.287E-02 6.752E-02 5.126E-02 1.816E-01 -1.514E-01 26th Coefficient (N) -2.639E-05 -2.088E-04 5.583E-04 -4.222E-03 -1.267E-02 -1.055E-02 -3.461E-02 3.003E-02 28th order coefficient (O) 1.604E-06 2.024E-05 -4.465E-05 4.568E-04 1.404E-03 1.267E-03 3.942E-03 -3.591E-03 30th order coefficient (P) -4.107E-08 -8.560E-07 1.618E-06 -2.199E-05 -6.962E-05 -6.752E-05 -2.030E-04 1.958E-04 S9 S10 S11 S12 S13 S14 S15 S16 Conic constant (K) -69.025 0.219 -89.401 -39.771 1.178 0.458 0.022 -10.273 4th order coefficient (A) -6.178E-02 -5.557E-02 -6.206E-02 -7.707E-02 -7.109E-02 -4.085E-02 -1.352E-01 -5.964E-02 6th order coefficient (B) 2.122E-01 1.125E-01 6.254E-02 5.434E-02 3.190E-02 1.083E-02 5.645E-02 2.059E-02 8th order coefficient (C) -1.071E+00 -3.704E-01 -7.415E-02 -2.560E-02 -2.461E-02 -8.717E-04 -1.761E-02 -5.002E-03 Tenth order coefficient (D) 3.521E+00 8.331E-01 5.546E-02 -1.515E-02 1.376E-02 -5.097E-03 4.068E-03 8.245E-04 12th order coefficient (E) -7.822E+00 -1.291E+00 -9.287E-03 4.049E-02 -4.741E-03 5.044E-03 -6.787E-04 -8.827E-05 14th order coefficient (F) 1.212E+01 1.406E+00 -3.470E-02 -3.909E-02 4.823E-04 -2.661E-03 8.232E-05 5.412E-06 16th order coefficient (G) -1.340E+01 -1.096E+00 4.757E-02 2.330E-02 3.777E-04 9.144E-04 -7.342E-06 -5.944E-08 18th order coefficient (H) 1.070E+01 6.174E-01 -3.398E-02 -9.434E-03 -2.165E-04 -2.167E-04 4.841E-07 -2.138E-08 20th order coefficient (J) -6.177E+00 -2.513E-01 1.575E-02 2.672E-03 5.912E-05 3.614E-05 -2.352E-08 2.165E-09 22nd Coefficient (L) 2.553E+00 7.306E-02 -4.976E-03 -5.297E-04 -9.983E-06 -4.234E-06 8.303E-10 -1.132E-10 24th order coefficient (M) -7.364E-01 -1.478E-02 1.068E-03 7.204E-05 1.089E-06 3.410E-07 -2.070E-11 3.676E-12 26th Coefficient (N) 1.407E-01 1.972E-03 -1.495E-04 -6.398E-06 -7.510E-08 -1.797E-08 3.449E-13 -7.447E-14 28th order coefficient (O) -1.599E-02 -1.558E-04 1.233E-05 3.340E-07 2.983E-09 5.577E-10 -3.446E-15 8.657E-16 30th order coefficient (P) 8.187E-04 5.511E-06 -4.536E-07 -7.772E-09 -5.216E-11 -7.719E-12 1.560E-17 -4.419E-18

Also, the imaging optical system configured as described above may have aberration characteristics shown in FIG. 6 .

An imaging optical system 400 according to a fourth embodiment of the present invention will be described with reference to FIGS. 7 and 8 .

An imaging optical system 400 according to a fourth embodiment of the present invention includes a first lens 410, a second lens 420, a third lens 430, a fourth lens 440, a fifth lens 450, It includes an optical system including a sixth lens 460, a seventh lens 470, and an eighth lens 480, and may further include a filter 490 and an image sensor IS.

The imaging optical system 400 according to the fourth embodiment of the present invention may form a focus on the imaging surface 491 . The imaging surface 491 may mean a surface on which a focus is formed by an imaging optical system. For example, the imaging surface 491 may refer to one surface of the image sensor IS through which light is received.

Table 7 shows the lens characteristics of each lens (radius of curvature, thickness of the lens or distance between the lenses, index of refraction, Abbe number, focal length).

side number note radius of curvature thickness or distance refractive index Abe number focal length S1 1st lens 2.566 0.819 1.544 56.0 7.07 S2 6.782 0.025 S3 2nd lens 4.841 0.220 1.680 18.2 -15.65 S4 3.279 0.189 S5 3rd lens 5.265 0.533 1.535 55.7 17.19 S6 11.819 0.248 S7 4th lens 38.407 0.250 1.567 37.4 174.08 S8 62.461 0.474 S9 5th lens 190.903 0.341 1.680 18.2 -39.17 S10 23.634 0.457 S11 6th lens 21.495 0.340 1.635 24.0 -500.09 S12 20.020 0.553 S13 7th lens 4.815 0.474 1.567 37.4 15.07 S14 10.552 1.281 S15 8th lens 10.678 0.525 1.544 56.0 -5.42 S16 2.276 0.229 S17 filter Infinity 0.110 1.517 64.2 S18 Infinity 0.770 S19 imaging plane Infinity

Meanwhile, the total focal length f of the imaging optical system 400 according to the fourth embodiment of the present invention is 7.35 mm, IMG HT is 7.145 mm, FOV is 86.2°, SAG52 is -0.488 mm, and SAG62 is -0.927 mm, SAG72 is -1.477 mm, and SAG82 is -1.850 mm.

In the fourth embodiment of the present invention, the first lens 410 has positive refractive power, the first surface of the first lens 410 is convex, and the second surface of the first lens 410 is concave. .

The second lens 420 has negative refractive power, the first surface of the second lens 420 is convex, and the second surface of the second lens 420 is concave.

The third lens 430 has positive refractive power, a first surface of the third lens 430 is convex, and a second surface of the third lens 430 is concave.

The fourth lens 440 has positive refractive power, a first surface of the fourth lens 440 is convex, and a second surface of the fourth lens 440 is concave.

The fifth lens 450 has negative refractive power, a first surface of the fifth lens 450 is convex, and a second surface of the fifth lens 450 is concave.

The sixth lens 460 has negative refractive power, a first surface of the sixth lens 460 is convex in the paraxial region, and a second surface of the sixth lens 460 is concave in the paraxial region.

In addition, at least one inflection point is formed on at least one of the first surface and the second surface of the sixth lens 460 . For example, the first surface of the sixth lens 460 may be convex in the paraxial region and concave in parts other than the paraxial region. The second surface of the sixth lens 460 may be concave in the paraxial region and convex in parts other than the paraxial region.

The seventh lens 470 has positive refractive power, a first surface of the seventh lens 470 is convex, and a second surface of the seventh lens 470 is concave.

In addition, at least one inflection point is formed on at least one of the first and second surfaces of the seventh lens 470 . For example, the first surface of the seventh lens 470 may be convex in the paraxial region and concave in parts other than the paraxial region. The second surface of the seventh lens 470 may be concave in the paraxial region and convex in parts other than the paraxial region.

The eighth lens 480 has negative refractive power, a first surface of the eighth lens 480 is convex in the paraxial region, and a second surface of the eighth lens 480 is concave in the paraxial region.

In addition, at least one inflection point is formed on at least one of the first and second surfaces of the eighth lens 480 . For example, the first surface of the eighth lens 480 may be convex in the paraxial region and concave in parts other than the paraxial region. The second surface of the eighth lens 480 may be concave in the paraxial region and convex in parts other than the paraxial region.

Meanwhile, each surface of the first lens 410 to the eighth lens 480 has an aspherical surface coefficient as shown in Table 8. For example, both the object-side surface and the image-side surface of the first lens 410 to the eighth lens 480 are aspheric surfaces.

S1 S2 S3 S4 S5 S6 S7 S8 Conic constant (K) -1.291 10.572 -11.034 -4.308 0.413 -8.205 61.581 3.924 4th order coefficient (A) 8.795E-03 5.771E-03 5.234E-03 -2.066E-03 -3.813E-03 -1.312E-02 -1.364E-02 -2.560E-02 6th order coefficient (B) -1.274E-04 -1.771E-02 1.639E-03 9.401E-03 1.552E-03 3.161E-02 -6.659E-02 6.573E-02 8th order coefficient (C) -3.352E-04 2.394E-02 -3.705E-02 -1.264E-02 1.389E-02 -9.871E-02 3.489E-01 -3.041E-01 Tenth order coefficient (D) 4.128E-03 -2.743E-02 1.336E-01 1.732E-02 -5.926E-02 1.982E-01 -1.084E+00 9.592E-01 12th order coefficient (E) -1.147E-02 2.775E-02 -2.674E-01 -5.686E-03 1.797E-01 -2.202E-01 2.288E+00 -2.034E+00 14th order coefficient (F) 1.695E-02 -3.155E-02 3.420E-01 -3.818E-02 -3.581E-01 8.357E-02 -3.401E+00 3.024E+00 16th order coefficient (G) -1.587E-02 3.621E-02 -2.964E-01 8.952E-02 4.778E-01 1.257E-01 3.642E+00 -3.228E+00 18th order coefficient (H) 1.009E-02 -3.183E-02 1.793E-01 -1.035E-01 -4.372E-01 -2.354E-01 -2.840E+00 2.504E+00 20th order coefficient (J) -4.479E-03 1.927E-02 -7.664E-02 7.461E-02 2.784E-01 1.973E-01 1.615E+00 -1.415E+00 22nd Coefficient (L) 1.396E-03 -7.857E-03 2.306E-02 -3.546E-02 -1.233E-01 -1.017E-01 -6.621E-01 5.763E-01 24th order coefficient (M) -2.996E-04 2.120E-03 -4.782E-03 1.115E-02 3.724E-02 3.400E-02 1.907E-01 -1.651E-01 26th Coefficient (N) 4.225E-05 -3.630E-04 6.515E-04 -2.236E-03 -7.325E-03 -7.206E-03 -3.657E-02 3.161E-02 28th order coefficient (O) -3.526E-06 3.574E-05 -5.256E-05 2.592E-04 8.457E-04 8.831E-04 4.196E-03 -3.636E-03 30th order coefficient (P) 1.320E-07 -1.541E-06 1.907E-06 -1.323E-05 -4.351E-05 -4.771E-05 -2.178E-04 1.904E-04 S9 S10 S11 S12 S13 S14 S15 S16 Conic constant (K) 99.000 -1.999 -88.686 -43.159 1.176 0.330 -0.054 -10.582 4th order coefficient (A) -6.001E-02 -5.664E-02 -6.090E-02 -7.805E-02 -6.886E-02 -4.072E-02 -1.342E-01 -6.145E-02 6th order coefficient (B) 1.966E-01 1.184E-01 5.342E-02 5.856E-02 2.108E-02 7.607E-03 5.571E-02 2.260E-02 8th order coefficient (C) -1.004E+00 -3.892E-01 -4.242E-02 -3.305E-02 -3.590E-03 4.796E-03 -1.735E-02 -6.075E-03 Tenth order coefficient (D) 3.349E+00 8.705E-01 -7.074E-03 -7.269E-03 -8.798E-03 -1.005E-02 4.013E-03 1.166E-03 12th order coefficient (E) -7.521E+00 -1.340E+00 6.855E-02 3.478E-02 1.054E-02 7.698E-03 -6.718E-04 -1.588E-04 14th order coefficient (F) 1.175E+01 1.451E+00 -9.999E-02 -3.604E-02 -6.495E-03 -3.607E-03 8.183E-05 1.539E-05 16th order coefficient (G) -1.307E+01 -1.125E+00 8.587E-02 2.205E-02 2.604E-03 1.148E-03 -7.332E-06 -1.056E-06 18th order coefficient (H) 1.047E+01 6.303E-01 -5.000E-02 -9.044E-03 -7.221E-04 -2.574E-04 4.859E-07 5.012E-08 20th order coefficient (J) -6.063E+00 -2.553E-01 2.054E-02 2.578E-03 1.412E-04 4.118E-05 -2.373E-08 -1.529E-09 22nd Coefficient (L) 2.511E+00 7.394E-02 -5.989E-03 -5.129E-04 -1.942E-05 -4.673E-06 8.423E-10 2.294E-11 24th order coefficient (M) -7.250E-01 -1.490E-02 1.215E-03 6.988E-05 1.840E-06 3.674E-07 -2.110E-11 1.829E-13 26th Coefficient (N) 1.386E-01 1.982E-03 -1.633E-04 -6.211E-06 -1.142E-07 -1.901E-08 3.536E-13 -1.530E-14 28th order coefficient (O) -1.576E-02 -1.561E-04 1.307E-05 3.244E-07 4.181E-09 5.815E-10 -3.551E-15 2.710E-16 30th order coefficient (P) 8.067E-04 5.507E-06 -4.706E-07 -7.546E-09 -6.851E-11 -7.961E-12 1.616E-17 -1.735E-18

In addition, the imaging optical system configured as described above may have aberration characteristics shown in FIG. 8 .

An imaging optical system 500 according to a fifth embodiment of the present invention will be described with reference to FIGS. 9 and 10 .

An imaging optical system 500 according to a fifth embodiment of the present invention includes a first lens 510, a second lens 520, a third lens 530, a fourth lens 540, a fifth lens 550, It includes an optical system including a sixth lens 560, a seventh lens 570, and an eighth lens 580, and may further include a filter 590 and an image sensor IS.

The imaging optical system 500 according to the fifth embodiment of the present invention may form a focus on the imaging surface 591 . The imaging surface 591 may mean a surface on which a focus is formed by an imaging optical system. For example, the imaging surface 591 may refer to one surface of the image sensor IS through which light is received.

Table 9 shows the lens characteristics of each lens (radius of curvature, thickness of the lens or distance between the lenses, index of refraction, Abbe number, focal length).

side number note radius of curvature thickness or distance refractive index Abe number focal length S1 1st lens 2.626 0.873 1.544 56.0 6.51 S2 8.871 0.027 S3 2nd lens 4.527 0.220 1.680 18.2 -16.55 S4 3.176 0.259 S5 3rd lens 7.225 0.454 1.535 55.7 24.21 S6 15.902 0.460 S7 4th lens 87.672 0.275 1.680 18.2 3953.4 S8 90.471 0.095 S9 5th lens -9.099 0.305 1.567 37.4 -102.84 S10 -10.899 0.595 S11 6th lens 11.730 0.342 1.614 25.9 -28.86 S12 7.006 0.346 S13 7th lens 6.009 0.455 1.567 37.4 9.18 S14 -39.843 1.363 S15 8th lens -34.685 0.515 1.535 55.7 -5.52 S16 3.258 0.300 S17 filter Infinity 0.110 1.517 64.2 S18 Infinity 0.826 S19 imaging plane Infinity

Meanwhile, the total focal length f of the imaging optical system 500 according to the fifth embodiment of the present invention is 7.24 mm, IMG HT is 7.145 mm, FOV is 87.2 °, SAG52 is -0.277 mm, and SAG62 is -0.794 mm, SAG72 is -1.130 mm, and SAG82 is -1.546 mm.

In the fifth embodiment of the present invention, the first lens 510 has a positive refractive power, the first surface of the first lens 510 is convex, and the second surface of the first lens 510 is concave. .

The second lens 520 has negative refractive power, the first surface of the second lens 520 is convex, and the second surface of the second lens 520 is concave.

The third lens 530 has positive refractive power, a first surface of the third lens 530 is convex, and a second surface of the third lens 530 is concave.

The fourth lens 540 has positive refractive power, a first surface of the fourth lens 540 is convex, and a second surface of the fourth lens 540 is concave.

The fifth lens 550 has negative refractive power, a first surface of the fifth lens 550 is concave, and a second surface of the fifth lens 550 is convex.

The sixth lens 560 has negative refractive power, a first surface of the sixth lens 560 is convex, and a second surface of the sixth lens 560 is concave.

In addition, at least one inflection point is formed on at least one of the first and second surfaces of the sixth lens 560 . For example, the first surface of the sixth lens 560 may be convex in the paraxial region and concave in parts other than the paraxial region. The second surface of the sixth lens 560 may be concave in the paraxial region and convex in parts other than the paraxial region.

The seventh lens 570 has positive refractive power, and the first and second surfaces of the seventh lens 570 are convex in the paraxial region.

In addition, at least one inflection point is formed on at least one of the first and second surfaces of the seventh lens 570 . For example, the first surface of the seventh lens 570 may be convex in the paraxial region and concave in parts other than the paraxial region. The second surface of the seventh lens 570 may be convex in the paraxial region and concave in parts other than the paraxial region.

The eighth lens 580 has negative refractive power, and the first and second surfaces of the eighth lens 580 are concave in the paraxial region.

In addition, at least one inflection point is formed on at least one of the first and second surfaces of the eighth lens 580 . For example, the first surface of the eighth lens 580 may be concave in the paraxial region and convex in parts other than the paraxial region. The second surface of the eighth lens 580 may be concave in the paraxial region and convex in parts other than the paraxial region.

Meanwhile, each surface of the first lens 510 to the eighth lens 580 has an aspherical surface coefficient as shown in Table 10. For example, both the object-side surface and the image-side surface of the first lens 510 to the eighth lens 580 are aspheric surfaces.

S1 S2 S3 S4 S5 S6 S7 S8 Conic constant (K) -0.895 21.148 -19.749 -5.002 4.823 -52.841 -99.000 -90.482 4th order coefficient (A) 2.170E-02 1.487E-02 -1.366E-02 7.491E-04 -1.298E-02 -5.756E-03 3.866E-02 1.738E-02 6th order coefficient (B) -1.014E-01 -2.277E-01 1.435E-02 -6.562E-02 8.776E-02 6.276E-02 -5.587E-01 -1.235E-01 8th order coefficient (C) 3.488E-01 9.573E-01 2.980E-02 3.269E-01 -3.606E-01 -3.187E-01 2.912E+00 3.137E-01 Tenth order coefficient (D) -7.332E-01 -2.283E+00 -3.391E-02 -8.594E-01 1.013E+00 1.131E+00 -1.000E+01 -6.306E-01 12th order coefficient (E) 1.026E+00 3.598E+00 -8.203E-02 1.501E+00 -1.940E+00 -2.828E+00 2.345E+01 9.128E-01 14th order coefficient (F) -1.001E+00 -3.983E+00 2.438E-01 -1.852E+00 2.635E+00 5.083E+00 -3.874E+01 -9.402E-01 16th order coefficient (G) 7.000E-01 3.191E+00 -3.011E-01 1.656E+00 -2.597E+00 -6.595E+00 4.599E+01 6.842E-01 18th order coefficient (H) -3.553E-01 -1.873E+00 2.264E-01 -1.086E+00 1.877E+00 6.185E+00 -3.964E+01 -3.460E-01 20th order coefficient (J) 1.311E-01 8.058E-01 -1.136E-01 5.218E-01 -9.947E-01 -4.176E+00 2.481E+01 1.172E-01 22nd Coefficient (L) -3.481E-02 -2.510E-01 3.898E-02 -1.813E-01 3.821E-01 2.005E+00 -1.116E+01 -2.427E-02 24th order coefficient (M) 6.472E-03 5.509E-02 -9.070E-03 4.432E-02 -1.035E-01 -6.665E-01 3.508E+00 2.176E-03 26th Coefficient (N) -7.991E-04 -8.073E-03 1.370E-03 -7.219E-03 1.873E-02 1.457E-01 -7.318E-01 1.992E-04 28th order coefficient (O) 5.884E-05 7.089E-04 -1.212E-04 7.029E-04 -2.033E-03 -1.880E-02 9.097E-02 -6.671E-05 30th order coefficient (P) -1.954E-06 -2.820E-05 4.766E-06 -3.092E-05 1.000E-04 1.086E-03 -5.098E-03 4.707E-06 S9 S10 S11 S12 S13 S14 S15 S16 Conic constant (K) 3.924 9.132 -6.150 2.180 2.311 -99.000 7.851 -12.311 4th order coefficient (A) 2.487E-02 -1.359E-02 -1.933E-02 -5.545E-02 -3.181E-02 -1.619E-03 -9.858E-02 -6.582E-02 6th order coefficient (B) -4.490E-02 4.159E-02 -6.914E-02 -3.500E-03 7.627E-03 7.334E-03 5.306E-02 3.441E-02 8th order coefficient (C) 5.471E-02 -1.281E-01 1.916E-01 4.333E-02 -3.057E-03 -8.380E-03 -2.157E-02 -1.272E-02 Tenth order coefficient (D) -9.463E-02 2.132E-01 -3.163E-01 -7.184E-02 -5.230E-03 2.577E-03 6.054E-03 3.231E-03 12th order coefficient (E) 1.763E-01 -2.243E-01 3.512E-01 7.034E-02 6.504E-03 4.377E-05 -1.155E-03 -5.794E-04 14th order coefficient (F) -2.442E-01 1.596E-01 -2.742E-01 -4.607E-02 -3.628E-03 -2.407E-04 1.538E-04 7.508E-05 16th Coefficient (G) 2.303E-01 -7.913E-02 1.536E-01 2.101E-02 1.272E-03 7.824E-05 -1.467E-05 -7.124E-06 18th order coefficient (H) -1.477E-01 2.768E-02 -6.223E-02 -6.793E-03 -3.062E-04 -1.406E-05 1.017E-06 4.972E-07 20th order coefficient (J) 6.493E-02 -6.842E-03 1.823E-02 1.564E-03 5.197E-05 1.664E-06 -5.139E-08 -2.541E-08 22nd Coefficient (L) -1.957E-02 1.184E-03 -3.817E-03 -2.543E-04 -6.201E-06 -1.364E-07 1.875E-09 9.376E-10 24th order coefficient (M) 3.973E-03 -1.400E-04 5.558E-04 2.844E-05 5.080E-07 7.778E-09 -4.812E-11 -2.427E-11 26th Coefficient (N) -5.197E-04 1.073E-05 -5.337E-05 -2.081E-06 -2.715E-08 -2.969E-10 8.251E-13 4.175E-13 28th order coefficient (O) 3.955E-05 -4.798E-07 3.036E-06 8.959E-08 8.520E-10 6.859E-12 -8.486E-15 -4.284E-15 30th order coefficient (P) -1.331E-06 9.480E-09 -7.736E-08 -1.720E-09 -1.190E-11 -7.264E-14 3.961E-17 1.984E-17

In addition, the imaging optical system configured as described above may have aberration characteristics shown in FIG. 10 .

An imaging optical system 600 according to a sixth embodiment of the present invention will be described with reference to FIGS. 11 and 12 .

An imaging optical system 600 according to a sixth embodiment of the present invention includes a first lens 610, a second lens 620, a third lens 630, a fourth lens 640, a fifth lens 650, It includes an optical system including a sixth lens 660, a seventh lens 670, and an eighth lens 680, and may further include a filter 690 and an image sensor IS.

The imaging optical system 600 according to the sixth embodiment of the present invention may form a focus on the imaging surface 691 . The imaging surface 691 may mean a surface on which a focus is formed by an imaging optical system. For example, the imaging surface 691 may refer to one surface of the image sensor IS through which light is received.

Table 11 shows the lens characteristics of each lens (radius of curvature, thickness of the lens or distance between lenses, index of refraction, Abbe number, focal length).

side number note radius of curvature thickness or distance refractive index Abe number focal length S1 1st lens 2.635 0.878 1.544 56.0 6.5 S2 9.007 0.025 S3 2nd lens 4.490 0.220 1.680 18.2 -15.55 S4 3.101 0.232 S5 3rd lens 6.974 0.477 1.535 55.7 22.03 S6 16.576 0.463 S7 4th lens 662.033 0.281 1.680 18.2 321.19 S8 -332.471 0.131 S9 5th lens -7.659 0.309 1.535 55.7 -110.18 S10 -8.922 0.554 S11 6th lens 12.649 0.340 1.614 25.9 -25.9 S12 7.003 0.320 S13 7th lens 6.009 0.453 1.567 37.4 9.27 S14 -43.227 1.406 S15 8th lens -27.274 0.550 1.535 55.7 -5.38 S16 3.252 0.300 S17 filter Infinity 0.110 1.517 64.2 S18 Infinity 0.770 S19 imaging plane Infinity

Meanwhile, the total focal length f of the imaging optical system 600 according to the sixth embodiment of the present invention is 7.23 mm, IMG HT is 7.145 mm, FOV is 87.2 °, SAG52 is -0.322 mm, and SAG62 is -0.770 mm, SAG72 is -1.098 mm, and SAG82 is -1.702 mm.

In the sixth embodiment of the present invention, the first lens 610 has a positive refractive power, the first surface of the first lens 610 is convex, and the second surface of the first lens 610 is concave. .

The second lens 620 has negative refractive power, a first surface of the second lens 620 is convex, and a second surface of the second lens 620 is concave.

The third lens 630 has positive refractive power, a first surface of the third lens 630 is convex, and a second surface of the third lens 630 is concave.

The fourth lens 640 has positive refractive power, and the first and second surfaces of the fourth lens 640 are convex.

The fifth lens 650 has negative refractive power, a first surface of the fifth lens 650 is concave, and a second surface of the fifth lens 650 is convex.

The sixth lens 660 has negative refractive power, a first surface of the sixth lens 660 is convex, and a second surface of the sixth lens 660 is concave.

In addition, at least one inflection point is formed on at least one of the first and second surfaces of the sixth lens 660 . For example, the first surface of the sixth lens 660 may be convex in the paraxial region and concave in parts other than the paraxial region. The second surface of the sixth lens 660 may be concave in the paraxial region and convex in parts other than the paraxial region.

The seventh lens 670 has positive refractive power, and the first and second surfaces of the seventh lens 670 are convex in the paraxial region.

In addition, at least one inflection point is formed on at least one of the first and second surfaces of the seventh lens 670 . For example, the first surface of the seventh lens 670 may be convex in the paraxial region and concave in parts other than the paraxial region. The second surface of the seventh lens 670 may be convex in the paraxial region and concave in parts other than the paraxial region.

The eighth lens 680 has negative refractive power, and the first and second surfaces of the eighth lens 680 are concave in the paraxial region.

In addition, at least one inflection point is formed on at least one of the first and second surfaces of the eighth lens 680 . For example, the first surface of the eighth lens 680 may be concave in the paraxial region and convex in parts other than the paraxial region. The second surface of the eighth lens 680 may be concave in the paraxial region and convex in parts other than the paraxial region.

Meanwhile, each surface of the first lens 610 to the eighth lens 680 has an aspherical surface coefficient as shown in Table 12. For example, both the object-side surface and the image-side surface of the first lens 610 to the eighth lens 680 are aspheric surfaces.

S1 S2 S3 S4 S5 S6 S7 S8 Conic constant (K) -0.943 21.060 -20.580 -5.410 4.340 -24.920 -99.000 -99.000 4th order coefficient (A) 1.758E-02 -7.350E-04 -2.142E-03 7.856E-04 -1.601E-02 3.244E-03 5.825E-03 2.691E-03 6th order coefficient (B) -6.172E-02 -7.034E-02 -1.760E-02 -5.626E-02 1.067E-01 -6.199E-03 -2.787E-01 -4.795E-02 8th order coefficient (C) 1.956E-01 3.503E-01 1.163E-01 2.485E-01 -4.237E-01 -3.835E-02 1.583E+00 4.444E-02 Tenth order coefficient (D) -3.893E-01 -9.227E-01 -2.873E-01 -5.783E-01 1.139E+00 3.692E-01 -6.055E+00 -1.239E-02 12th order coefficient (E) 5.236E-01 1.570E+00 4.415E-01 8.652E-01 -2.123E+00 -1.311E+00 1.558E+01 -4.270E-02 14th order coefficient (F) -4.961E-01 -1.845E+00 -4.678E-01 -8.672E-01 2.872E+00 2.805E+00 -2.780E+01 8.203E-02 16th order coefficient (G) 3.394E-01 1.547E+00 3.573E-01 5.861E-01 -2.878E+00 -4.012E+00 3.518E+01 -8.533E-02 18th order coefficient (H) -1.696E-01 -9.397E-01 -2.012E-01 -2.591E-01 2.148E+00 3.991E+00 -3.201E+01 6.520E-02 20th order coefficient (J) 6.186E-02 4.147E-01 8.419E-02 6.617E-02 -1.187E+00 -2.800E+00 2.099E+01 -3.866E-02 22nd Coefficient (L) -1.628E-02 -1.316E-01 -2.597E-02 -3.858E-03 4.777E-01 1.381E+00 -9.830E+00 1.709E-02 24th order coefficient (M) 3.009E-03 2.926E-02 5.755E-03 -3.408E-03 -1.357E-01 -4.679E-01 3.206E+00 -5.283E-03 26th Coefficient (N) -3.700E-04 -4.324E-03 -8.667E-04 1.212E-03 2.574E-02 1.037E-01 -6.913E-01 1.061E-03 28th order coefficient (O) 2.714E-05 3.815E-04 7.930E-05 -1.780E-04 -2.920E-03 -1.354E-02 8.860E-02 -1.233E-04 30th order coefficient (P) -8.982E-07 -1.520E-05 -3.318E-06 1.035E-05 1.497E-04 7.881E-04 -5.109E-03 6.271E-06 S9 S10 S11 S12 S13 S14 S15 S16 Conic constant (K) 4.744 9.055 -8.064 2.753 2.315 96.850 2.795 -12.391 4th order coefficient (A) 2.296E-02 -2.946E-03 -2.230E-02 -5.333E-02 -1.955E-02 6.421E-03 -9.791E-02 -6.704E-02 6th order coefficient (B) -3.313E-02 2.048E-02 -8.473E-02 -3.706E-02 -2.156E-02 -3.342E-03 5.528E-02 3.529E-02 8th order coefficient (C) 5.044E-02 -9.243E-02 2.299E-01 1.203E-01 3.689E-02 2.098E-03 -2.310E-02 -1.279E-02 Tenth order coefficient (D) -1.307E-01 1.800E-01 -3.522E-01 -1.764E-01 -4.344E-02 -6.081E-03 6.504E-03 3.147E-03 12th order coefficient (E) 2.654E-01 -2.118E-01 3.559E-01 1.649E-01 3.131E-02 4.994E-03 -1.235E-03 -5.450E-04 14th order coefficient (F) -3.648E-01 1.643E-01 -2.513E-01 -1.053E-01 -1.463E-02 -2.119E-03 1.637E-04 6.830E-05 16th order coefficient (G) 3.410E-01 -8.722E-02 1.273E-01 4.735E-02 4.699E-03 5.632E-04 -1.556E-05 -6.290E-06 18th order coefficient (H) -2.193E-01 3.230E-02 -4.675E-02 -1.522E-02 -1.071E-03 -1.014E-04 1.078E-06 4.281E-07 20th order coefficient (J) 9.772E-02 -8.402E-03 1.247E-02 3.505E-03 1.751E-04 1.279E-05 -5.461E-08 -2.145E-08 22nd Coefficient (L) -3.008E-02 1.525E-03 -2.386E-03 -5.730E-04 -2.041E-05 -1.136E-06 2.002E-09 7.801E-10 24th order coefficient (M) 6.282E-03 -1.890E-04 3.186E-04 6.477E-05 1.654E-06 6.990E-08 -5.174E-11 -2.000E-11 26th Coefficient (N) -8.503E-04 1.521E-05 -2.814E-05 -4.808E-06 -8.846E-08 -2.837E-09 8.948E-13 3.425E-13 28th order coefficient (O) 6.746E-05 -7.164E-07 1.473E-06 2.108E-07 2.805E-09 6.842E-11 -9.297E-15 -3.513E-15 30th order coefficient (P) -2.387E-06 1.497E-08 -3.452E-08 -4.132E-09 -3.992E-11 -7.428E-13 4.389E-17 1.633E-17

Also, the imaging optical system configured as above may have aberration characteristics shown in FIG. 12 .

An imaging optical system 700 according to a seventh embodiment of the present invention will be described with reference to FIGS. 13 and 14 .

An imaging optical system 700 according to a seventh embodiment of the present invention includes a first lens 710, a second lens 720, a third lens 730, a fourth lens 740, a fifth lens 750, It includes an optical system including a sixth lens 760, a seventh lens 770, and an eighth lens 780, and may further include a filter 790 and an image sensor IS.

The imaging optical system 700 according to the seventh embodiment of the present invention may form a focus on the imaging surface 791 . The imaging surface 791 may mean a surface on which a focus is formed by an imaging optical system. For example, the imaging surface 791 may refer to one surface of the image sensor IS through which light is received.

Table 13 shows the lens characteristics of each lens (radius of curvature, thickness of the lens or distance between the lenses, index of refraction, Abbe number, focal length).

side number note radius of curvature thickness or distance refractive index Abe number focal length S1 1st lens 2.637 0.888 1.544 56.0 6.5 S2 9.026 0.025 S3 2nd lens 4.387 0.220 1.680 18.2 -15.17 S4 3.027 0.231 S5 3rd lens 6.457 0.476 1.535 55.7 21.34 S6 14.404 0.469 S7 4th lens 171.706 0.279 1.680 18.2 689.79 S8 268.619 0.124 S9 5th lens -8.033 0.300 1.535 55.7 -124.32 S10 -9.250 0.528 S11 6th lens 12.712 0.340 1.614 25.9 -25.87 S12 7.018 0.335 S13 7th lens 6.037 0.450 1.567 37.4 9.23 S14 -40.147 1.376 S15 8th lens -26.801 0.592 1.535 55.7 -5.43 S16 3.295 0.300 S17 filter Infinity 0.110 1.517 64.2 S18 Infinity 0.778 S19 imaging plane Infinity

Meanwhile, the total focal length f of the imaging optical system 700 according to the seventh embodiment of the present invention is 7.23 mm, IMG HT is 7.145 mm, FOV is 87.2°, SAG52 is -0.297 mm, and SAG62 is -0.758 mm, SAG72 is -1.071 mm, and SAG82 is -1.716 mm.

In the seventh embodiment of the present invention, the first lens 710 has a positive refractive power, the first surface of the first lens 710 is convex, and the second surface of the first lens 710 is concave. .

The second lens 720 has negative refractive power, a first surface of the second lens 720 is convex, and a second surface of the second lens 720 is concave.

The third lens 730 has a positive refractive power, a first surface of the third lens 730 is convex, and a second surface of the third lens 730 is concave.

The fourth lens 740 has positive refractive power, a first surface of the fourth lens 740 is convex, and a second surface of the fourth lens 740 is concave.

The fifth lens 750 has negative refractive power, a first surface of the fifth lens 750 is concave, and a second surface of the fifth lens 750 is convex.

The sixth lens 760 has negative refractive power, a first surface of the sixth lens 760 is convex, and a second surface of the sixth lens 760 is concave.

In addition, at least one inflection point is formed on at least one of the first and second surfaces of the sixth lens 760 . For example, the first surface of the sixth lens 760 may be convex in the paraxial region and concave in parts other than the paraxial region. The second surface of the sixth lens 760 may be concave in the paraxial region and convex in parts other than the paraxial region.

The seventh lens 770 has positive refractive power, and the first and second surfaces of the seventh lens 770 are convex in the paraxial region.

In addition, at least one inflection point is formed on at least one of the first and second surfaces of the seventh lens 770 . For example, the first surface of the seventh lens 770 may be convex in the paraxial region and concave in parts other than the paraxial region. The second surface of the seventh lens 770 may be convex in the paraxial region and concave in parts other than the paraxial region.

The eighth lens 780 has negative refractive power, and the first and second surfaces of the eighth lens 780 are concave in the paraxial region.

In addition, at least one inflection point is formed on at least one of the first and second surfaces of the eighth lens 780 . For example, the first surface of the eighth lens 780 may be concave in the paraxial region and convex in parts other than the paraxial region. The second surface of the eighth lens 780 may be concave in the paraxial region and convex in parts other than the paraxial region.

Meanwhile, each surface of the first lens 710 to the eighth lens 780 has an aspherical surface coefficient as shown in Table 14. For example, both the object side surface and the image side surface of the first lens 710 to the eighth lens 780 are aspheric surfaces.

S1 S2 S3 S4 S5 S6 S7 S8 Conic constant (K) -0.949 20.988 -20.519 -5.487 4.218 -1.339 -86.054 -99.000 4th order coefficient (A) 1.594E-02 -2.623E-03 -1.160E-03 -3.004E-03 -1.615E-02 8.864E-03 7.941E-03 6.929E-03 6th order coefficient (B) -5.401E-02 -5.272E-02 -2.205E-02 -3.842E-02 1.097E-01 -2.314E-02 -3.115E-01 -9.079E-02 8th order coefficient (C) 1.748E-01 2.730E-01 1.237E-01 2.037E-01 -4.327E-01 -7.615E-02 1.746E+00 2.040E-01 Tenth order coefficient (D) -3.525E-01 -7.088E-01 -2.739E-01 -5.267E-01 1.154E+00 8.740E-01 -6.578E+00 -4.053E-01 12th order coefficient (E) 4.789E-01 1.176E+00 3.608E-01 8.802E-01 -2.139E+00 -3.259E+00 1.681E+01 6.445E-01 14th order coefficient (F) -4.585E-01 -1.343E+00 -3.013E-01 -1.010E+00 2.887E+00 7.146E+00 -2.993E+01 -7.777E-01 16th order coefficient (G) 3.176E-01 1.092E+00 1.546E-01 8.211E-01 -2.893E+00 -1.038E+01 3.792E+01 6.884E-01 18th order coefficient (H) -1.611E-01 -6.434E-01 -3.837E-02 -4.817E-01 2.162E+00 1.045E+01 -3.458E+01 -4.380E-01 20th order coefficient (J) 5.980E-02 2.754E-01 -5.495E-03 2.057E-01 -1.198E+00 -7.420E+00 2.274E+01 1.976E-01 22nd Coefficient (L) -1.606E-02 -8.487E-02 8.155E-03 -6.381E-02 4.834E-01 3.703E+00 -1.068E+01 -6.212E-02 24th order coefficient (M) 3.031E-03 1.835E-02 -3.082E-03 1.413E-02 -1.376E-01 -1.272E+00 3.494E+00 1.318E-02 26th Coefficient (N) -3.810E-04 -2.643E-03 6.208E-04 -2.138E-03 2.615E-02 2.866E-01 -7.555E-01 -1.780E-03 28th order coefficient (O) 2.861E-05 2.277E-04 -6.757E-05 1.995E-04 -2.971E-03 -3.809E-02 9.706E-02 1.355E-04 30th order coefficient (P) -9.699E-07 -8.875E-06 3.139E-06 -8.688E-06 1.524E-04 2.264E-03 -5.609E-03 -4.297E-06 S9 S10 S11 S12 S13 S14 S15 S16 Conic constant (K) 4.264 9.184 -11.870 2.834 2.319 83.418 2.941 -11.316 4th order coefficient (A) 3.749E-02 4.177E-03 -2.364E-02 -5.703E-02 -2.272E-02 3.968E-03 -9.212E-02 -6.560E-02 6th order coefficient (B) -1.025E-01 -1.901E-03 -8.963E-02 -1.635E-02 -2.443E-03 4.768E-03 4.983E-02 3.409E-02 8th order coefficient (C) 2.278E-01 -4.981E-02 2.721E-01 7.419E-02 7.677E-03 -7.204E-03 -2.066E-02 -1.252E-02 Tenth order coefficient (D) -4.386E-01 1.250E-01 -4.770E-01 -1.212E-01 -1.798E-02 2.347E-04 5.839E-03 3.148E-03 12th order coefficient (E) 6.430E-01 -1.614E-01 5.524E-01 1.228E-01 1.686E-02 2.149E-03 -1.112E-03 -5.592E-04 14th order coefficient (F) -6.891E-01 1.310E-01 -4.445E-01 -8.350E-02 -9.047E-03 -1.238E-03 1.476E-04 7.190E-05 16th order coefficient (G) 5.317E-01 -7.149E-02 2.550E-01 3.944E-02 3.190E-03 3.725E-04 -1.403E-05 -6.788E-06 18th order coefficient (H) -2.922E-01 2.700E-02 -1.057E-01 -1.320E-02 -7.834E-04 -7.245E-05 9.696E-07 4.727E-07 20th order coefficient (J) 1.132E-01 -7.135E-03 3.169E-02 3.146E-03 1.367E-04 9.725E-06 -4.886E-08 -2.418E-08 22nd Coefficient (L) -3.032E-02 1.314E-03 -6.808E-03 -5.298E-04 -1.688E-05 -9.163E-07 1.779E-09 8.951E-10 24th order coefficient (M) 5.430E-03 -1.649E-04 1.020E-03 6.150E-05 1.441E-06 5.979E-08 -4.556E-11 -2.331E-11 26th Coefficient (N) -6.094E-04 1.345E-05 -1.011E-04 -4.678E-06 -8.084E-08 -2.580E-09 7.794E-13 4.048E-13 28th order coefficient (O) 3.755E-05 -6.411E-07 5.954E-06 2.098E-07 2.679E-09 6.629E-11 -7.994E-15 -4.204E-15 30th order coefficient (P) -9.066E-07 1.357E-08 -1.575E-07 -4.202E-09 -3.973E-11 -7.686E-13 3.719E-17 1.975E-17

Also, the imaging optical system configured as above may have aberration characteristics shown in FIG. 14 .

An imaging optical system 800 according to an eighth embodiment of the present invention will be described with reference to FIGS. 15 and 16 .

An imaging optical system 800 according to an eighth embodiment of the present invention includes a first lens 810, a second lens 820, a third lens 830, a fourth lens 840, a fifth lens 850, It includes an optical system including a sixth lens 860, a seventh lens 870, and an eighth lens 880, and may further include a filter 890 and an image sensor IS.

The imaging optical system 800 according to the eighth embodiment of the present invention may form a focus on the imaging surface 891 . The imaging surface 891 may mean a surface on which a focus is formed by an imaging optical system. For example, the imaging surface 891 may refer to one surface of the image sensor IS through which light is received.

Table 15 shows the lens characteristics of each lens (radius of curvature, thickness of the lens or distance between lenses, index of refraction, Abbe number, focal length).

side number note radius of curvature thickness or distance refractive index Abe number focal length S1 1st lens 2.588 0.808 1.544 56.0 7.08 S2 6.966 0.025 S3 2nd lens 5.731 0.220 1.680 18.2 -16.19 S4 3.727 0.177 S5 3rd lens 5.321 0.495 1.535 55.7 19.24 S6 10.608 0.275 S7 4th lens 64.629 0.263 1.567 37.4 82.36 S8 -172.166 0.475 S9 5th lens 48.453 0.304 1.680 18.2 -32.82 S10 15.380 0.440 S11 6th lens 24.823 0.343 1.635 24.0 -455.55 S12 22.754 0.595 S13 7th lens 4.765 0.555 1.567 37.4 13.54 S14 11.898 1.237 S15 8th lens 10.129 0.450 1.544 56.0 -6.02 S16 2.444 0.272 S17 filter Infinity 0.110 1.517 64.2 S18 Infinity 0.795 S19 imaging plane Infinity

Meanwhile, the total focal length f of the imaging optical system 800 according to the eighth embodiment of the present invention is 7.24 mm, IMG HT is 7.145 mm, FOV is 87.2 °, SAG52 is -0.465 mm, and SAG62 is -0.907 mm, SAG72 is -1.555 mm, and SAG82 is -1.713 mm.

In the eighth embodiment of the present invention, the first lens 810 has a positive refractive power, the first surface of the first lens 810 is convex, and the second surface of the first lens 810 is concave. .

The second lens 820 has negative refractive power, the first surface of the second lens 820 is convex, and the second surface of the second lens 820 is concave.

The third lens 830 has positive refractive power, a first surface of the third lens 830 is convex, and a second surface of the third lens 830 is concave.

The fourth lens 840 has positive refractive power, and the first and second surfaces of the fourth lens 840 are convex.

The fifth lens 850 has negative refractive power, a first surface of the fifth lens 850 is convex, and a second surface of the fifth lens 850 is concave.

The sixth lens 860 has negative refractive power, a first surface of the sixth lens 860 is convex, and a second surface of the sixth lens 860 is concave.

In addition, at least one inflection point is formed on at least one of the first and second surfaces of the sixth lens 860 . For example, the first surface of the sixth lens 860 may be convex in the paraxial region and concave in parts other than the paraxial region. The second surface of the sixth lens 860 may be concave in the paraxial region and convex in parts other than the paraxial region.

The seventh lens 870 has positive refractive power, a first surface of the seventh lens 870 is convex in the paraxial region, and a second surface of the seventh lens 870 is concave in the paraxial region.

In addition, at least one inflection point is formed on at least one of the first and second surfaces of the seventh lens 870 . For example, the first surface of the seventh lens 870 may be convex in the paraxial region and concave in parts other than the paraxial region. The second surface of the seventh lens 870 may be concave in the paraxial region and convex in parts other than the paraxial region.

The eighth lens 880 has negative refractive power, a first surface of the eighth lens 880 is convex in the paraxial region, and a second surface of the eighth lens 880 is concave in the paraxial region.

In addition, at least one inflection point is formed on at least one of the first and second surfaces of the eighth lens 880 . For example, the first surface of the eighth lens 880 may be convex in the paraxial region and concave in parts other than the paraxial region. The second surface of the eighth lens 880 may be concave in the paraxial region and convex in parts other than the paraxial region.

Meanwhile, each surface of the first lens 810 to the eighth lens 880 has an aspherical surface coefficient as shown in Table 16. For example, both the object-side surface and the image-side surface of the first lens 810 to the eighth lens 880 are aspheric surfaces.

S1 S2 S3 S4 S5 S6 S7 S8 Conic constant (K) -1.405 10.710 -10.030 -4.131 0.046 -2.522 -99.000 -1.654 4th order coefficient (A) 1.033E-02 3.152E-02 2.769E-02 6.383E-03 -1.273E-02 -6.531E-03 -7.438E-03 -2.400E-02 6th order coefficient (B) -9.338E-03 -2.107E-01 -1.693E-01 -5.834E-02 4.066E-02 8.877E-03 -9.261E-02 9.506E-02 8th order coefficient (C) 3.460E-02 7.022E-01 5.827E-01 2.525E-01 -1.314E-01 -1.151E-01 4.761E-01 -4.943E-01 Tenth order coefficient (D) -7.979E-02 -1.535E+00 -1.292E+00 -6.345E-01 2.800E-01 5.649E-01 -1.449E+00 1.607E+00 12th order coefficient (E) 1.200E-01 2.315E+00 1.980E+00 1.079E+00 -3.443E-01 -1.572E+00 2.908E+00 -3.442E+00 14th order coefficient (F) -1.237E-01 -2.483E+00 -2.166E+00 -1.301E+00 1.969E-01 2.861E+00 -4.033E+00 5.113E+00 16th order coefficient (G) 9.010E-02 1.932E+00 1.721E+00 1.140E+00 6.994E-02 -3.593E+00 3.970E+00 -5.432E+00 18th order coefficient (H) -4.708E-02 -1.100E+00 -1.002E+00 -7.347E-01 -2.322E-01 3.194E+00 -2.812E+00 4.192E+00 20th order coefficient (J) 1.772E-02 4.585E-01 4.271E-01 3.487E-01 2.121E-01 -2.027E+00 1.435E+00 -2.358E+00 22nd Coefficient (L) -4.757E-03 -1.381E-01 -1.316E-01 -1.206E-01 -1.123E-01 9.121E-01 -5.221E-01 9.581E-01 24th order coefficient (M) 8.883E-04 2.928E-02 2.855E-02 2.958E-02 3.782E-02 -2.843E-01 1.317E-01 -2.741E-01 26th Coefficient (N) -1.095E-04 -4.141E-03 -4.132E-03 -4.877E-03 -8.010E-03 5.836E-02 -2.186E-02 5.239E-02 28th order coefficient (O) 8.008E-06 3.505E-04 3.579E-04 4.845E-04 9.773E-04 -7.094E-03 2.140E-03 -6.012E-03 30th order coefficient (P) -2.627E-07 -1.343E-05 -1.403E-05 -2.190E-05 -5.258E-05 3.866E-04 -9.343E-05 3.133E-04 S9 S10 S11 S12 S13 S14 S15 S16 Conic constant (K) -91.947 -8.094 -62.550 -24.666 1.134 -0.257 0.000 -7.956 4th order coefficient (A) -5.332E-02 -6.037E-02 -5.156E-02 -8.572E-02 -6.041E-02 -3.600E-02 -1.394E-01 -8.865E-02 6th order coefficient (B) 1.227E-01 1.347E-01 -2.055E-02 7.248E-02 1.267E-02 1.135E-02 6.304E-02 4.238E-02 8th order coefficient (C) -5.699E-01 -4.495E-01 1.887E-01 -6.796E-02 -1.973E-05 -7.236E-03 -2.108E-02 -1.379E-02 Tenth order coefficient (D) 1.780E+00 1.034E+00 -4.415E-01 5.593E-02 -4.776E-03 4.636E-03 5.005E-03 3.088E-03 12th order coefficient (E) -3.794E+00 -1.640E+00 6.199E-01 -3.693E-02 4.730E-03 -2.399E-03 -8.318E-04 -4.879E-04 14th order coefficient (F) 5.678E+00 1.830E+00 -5.914E-01 1.780E-02 -3.021E-03 8.616E-04 9.856E-05 5.548E-05 16th order coefficient (G) -6.092E+00 -1.462E+00 3.988E-01 -5.912E-03 1.358E-03 -2.053E-04 -8.483E-06 -4.602E-06 18th order coefficient (H) 4.737E+00 8.442E-01 -1.932E-01 1.252E-03 -4.278E-04 3.165E-05 5.357E-07 2.798E-07 20th order coefficient (J) -2.673E+00 -3.525E-01 6.744E-02 -1.328E-04 9.353E-05 -2.956E-06 -2.482E-08 -1.242E-08 22nd Coefficient (L) 1.083E+00 1.052E-01 -1.678E-02 -5.391E-06 -1.404E-05 1.272E-07 8.340E-10 3.964E-10 24th order coefficient (M) -3.065E-01 -2.187E-02 2.904E-03 3.884E-06 1.416E-06 3.535E-09 -1.977E-11 -8.832E-12 26th Coefficient (N) 5.754E-02 3.002E-03 -3.316E-04 -5.493E-07 -9.155E-08 -7.331E-10 3.134E-13 1.300E-13 28th order coefficient (O) -6.433E-03 -2.443E-04 2.247E-05 3.645E-08 3.430E-09 3.503E-11 -2.981E-15 -1.132E-15 30th order coefficient (P) 3.241E-04 8.915E-06 -6.844E-07 -9.807E-10 -5.663E-11 -6.022E-13 1.286E-17 4.396E-18

In addition, the imaging optical system configured as described above may have aberration characteristics shown in FIG. 16 .

An imaging optical system 900 according to a ninth embodiment of the present invention will be described with reference to FIGS. 17 and 18 .

An imaging optical system 900 according to a ninth embodiment of the present invention includes a first lens 910, a second lens 920, a third lens 930, a fourth lens 940, a fifth lens 950, It includes an optical system including a sixth lens 960, a seventh lens 970, and an eighth lens 980, and may further include a filter 990 and an image sensor IS.

The imaging optical system 900 according to the ninth embodiment of the present invention may form a focus on the imaging surface 991 . The imaging surface 991 may mean a surface on which a focus is formed by an imaging optical system. For example, the imaging surface 991 may refer to one surface of the image sensor IS through which light is received.

Table 17 shows the lens characteristics of each lens (radius of curvature, thickness of the lens or distance between the lenses, index of refraction, Abbe number, focal length).

side number note radius of curvature thickness or distance refractive index Abe number focal length S1 1st lens 2.574 0.790 1.544 56.0 7.09 S2 6.851 0.025 S3 2nd lens 5.666 0.220 1.680 18.2 -16.4 S4 3.714 0.178 S5 3rd lens 5.493 0.510 1.535 55.7 18.53 S6 11.862 0.277 S7 4th lens 249.628 0.253 1.567 37.4 108.63 S8 -82.455 0.469 S9 5th lens 68.058 0.305 1.680 18.2 -31.39 S10 16.384 0.440 S11 6th lens 17.841 0.340 1.635 24.0 -6283.41 S12 17.630 0.614 S13 7th lens 4.769 0.549 1.567 37.4 13.41 S14 12.115 1.216 S15 8th lens 10.670 0.450 1.544 56.0 -6.1 S16 2.500 0.272 S17 filter Infinity 0.110 1.517 64.2 S18 Infinity 0.822 S19 imaging plane Infinity

Meanwhile, the total focal length f of the imaging optical system 900 according to the ninth embodiment of the present invention is 7.24 mm, IMG HT is 7.145 mm, FOV is 87.2°, SAG52 is -0.464 mm, and SAG62 is -0.903 mm, SAG72 is -1.562 mm, and SAG82 is -1.769 mm.

In the ninth embodiment of the present invention, the first lens 910 has a positive refractive power, the first surface of the first lens 910 is convex, and the second surface of the first lens 910 is concave. .

The second lens 920 has negative refractive power, the first surface of the second lens 920 is convex, and the second surface of the second lens 920 is concave.

The third lens 930 has positive refractive power, a first surface of the third lens 930 is convex, and a second surface of the third lens 930 is concave.

The fourth lens 940 has positive refractive power, and the first and second surfaces of the fourth lens 940 are convex.

The fifth lens 950 has negative refractive power, a first surface of the fifth lens 950 is convex, and a second surface of the fifth lens 950 is concave.

The sixth lens 960 has negative refractive power, a first surface of the sixth lens 960 is convex, and a second surface of the sixth lens 960 is concave.

In addition, at least one inflection point is formed on at least one of the first and second surfaces of the sixth lens 960 . For example, the first surface of the sixth lens 960 may be convex in the paraxial region and concave in parts other than the paraxial region. The second surface of the sixth lens 960 may be concave in the paraxial region and convex in parts other than the paraxial region.

The seventh lens 970 has positive refractive power, a first surface of the seventh lens 970 is convex in the paraxial region, and a second surface of the seventh lens 970 is concave in the paraxial region.

In addition, at least one inflection point is formed on at least one of the first and second surfaces of the seventh lens 970 . For example, the first surface of the seventh lens 970 may be convex in the paraxial region and concave in parts other than the paraxial region. The second surface of the seventh lens 970 may be concave in the paraxial region and convex in parts other than the paraxial region.

The eighth lens 980 has negative refractive power, a first surface of the eighth lens 980 is convex in the paraxial region, and a second surface of the eighth lens 980 is concave in the paraxial region.

In addition, at least one inflection point is formed on at least one of the first and second surfaces of the eighth lens 980 . For example, the first surface of the eighth lens 980 may be convex in the paraxial region and concave in parts other than the paraxial region. The second surface of the eighth lens 980 may be concave in the paraxial region and convex in parts other than the paraxial region.

Meanwhile, each surface of the first lens 910 to the eighth lens 980 has an aspherical surface coefficient as shown in Table 18. For example, both the object-side surface and the image-side surface of the first lens 910 to the eighth lens 980 are aspheric surfaces.

S1 S2 S3 S4 S5 S6 S7 S8 Conic constant (K) -1.409 10.628 -10.223 -4.310 0.269 -6.764 -99.000 99.000 4th order coefficient (A) 4.785E-03 1.137E-03 -4.263E-04 -5.237E-03 -1.003E-02 -1.560E-02 -1.226E-02 -2.778E-02 6th order coefficient (B) 1.987E-02 -1.686E-02 2.781E-02 4.740E-02 3.698E-02 8.897E-02 -5.725E-02 1.251E-01 8th order coefficient (C) -6.572E-02 7.589E-02 -9.975E-02 -1.780E-01 -1.336E-01 -4.343E-01 3.047E-01 -6.939E-01 Tenth order coefficient (D) 1.480E-01 -2.068E-01 2.694E-01 4.786E-01 3.556E-01 1.251E+00 -9.669E-01 2.372E+00 12th order coefficient (E) -2.299E-01 3.495E-01 -5.189E-01 -8.836E-01 -6.276E-01 -2.329E+00 2.052E+00 -5.292E+00 14th order coefficient (F) 2.502E-01 -4.149E-01 6.759E-01 1.126E+00 7.400E-01 2.986E+00 -3.025E+00 8.151E+00 16th order coefficient (G) -1.937E-01 3.666E-01 -5.995E-01 -1.005E+00 -5.795E-01 -2.727E+00 3.181E+00 -8.947E+00 18th order coefficient (H) 1.079E-01 -2.435E-01 3.687E-01 6.379E-01 2.904E-01 1.808E+00 -2.421E+00 7.114E+00 20th order coefficient (J) -4.330E-02 1.201E-01 -1.586E-01 -2.883E-01 -8.013E-02 -8.752E-01 1.337E+00 -4.113E+00 22nd Coefficient (L) 1.241E-02 -4.296E-02 4.746E-02 9.192E-02 1.976E-03 3.071E-01 -5.306E-01 1.713E+00 24th order coefficient (M) -2.478E-03 1.077E-02 -9.635E-03 -2.014E-02 7.022E-03 -7.634E-02 1.475E-01 -5.006E-01 26th Coefficient (N) 3.276E-04 -1.786E-03 1.257E-03 2.873E-03 -2.548E-03 1.279E-02 -2.730E-02 9.749E-02 28th order coefficient (O) -2.577E-05 1.756E-04 -9.397E-05 -2.388E-04 4.025E-04 -1.300E-03 3.018E-03 -1.136E-02 30th order coefficient (P) 9.134E-07 -7.742E-06 3.003E-06 8.694E-06 -2.532E-05 6.078E-05 -1.510E-04 5.997E-04 S9 S10 S11 S12 S13 S14 S15 S16 Conic constant (K) -9.120 -8.890 -99.000 -25.258 1.124 -1.114 -0.028 -9.532 4th order coefficient (A) -4.552E-02 -5.969E-02 -6.151E-02 -8.588E-02 -6.004E-02 -3.723E-02 -1.412E-01 -8.214E-02 6th order coefficient (B) 4.112E-02 1.273E-01 2.919E-02 6.123E-02 6.548E-03 1.165E-02 6.995E-02 4.074E-02 8th order coefficient (C) -1.818E-01 -4.419E-01 4.086E-02 -2.208E-02 1.787E-02 -4.492E-03 -2.601E-02 -1.361E-02 Tenth order coefficient (D) 6.655E-01 1.060E+00 -1.524E-01 -3.612E-02 -3.157E-02 -3.394E-04 6.729E-03 3.052E-03 12th order coefficient (E) -1.712E+00 -1.741E+00 2.314E-01 7.624E-02 2.853E-02 1.654E-03 -1.195E-03 -4.718E-04 14th order coefficient (F) 3.031E+00 1.998E+00 -2.211E-01 -7.431E-02 -1.672E-02 -1.120E-03 1.493E-04 5.151E-05 16th order coefficient (G) -3.745E+00 -1.631E+00 1.444E-01 4.571E-02 6.722E-03 4.344E-04 -1.341E-05 -4.028E-06 18th order coefficient (H) 3.272E+00 9.580E-01 -6.641E-02 -1.909E-02 -1.893E-03 -1.103E-04 8.765E-07 2.264E-07 20th order coefficient (J) -2.032E+00 -4.053E-01 2.176E-02 5.546E-03 3.754E-04 1.904E-05 -4.180E-08 -9.054E-09 22nd Coefficient (L) 8.907E-01 1.222E-01 -5.069E-03 -1.121E-03 -5.204E-05 -2.251E-06 1.440E-09 2.512E-10 24th order coefficient (M) -2.693E-01 -2.560E-02 8.259E-04 1.545E-04 4.927E-06 1.794E-07 -3.487E-11 -4.594E-12 26th Coefficient (N) 5.345E-02 3.535E-03 -9.036E-05 -1.386E-05 -3.032E-07 -9.212E-09 5.636E-13 4.979E-14 28th order coefficient (O) -6.263E-03 -2.889E-04 6.037E-06 7.280E-07 1.093E-08 2.752E-10 -5.459E-15 -2.438E-16 30th order coefficient (P) 3.285E-04 1.057E-05 -1.882E-07 -1.701E-08 -1.750E-10 -3.635E-12 2.396E-17 2.995E-20

In addition, the imaging optical system configured in this way may have aberration characteristics shown in FIG. 18 .

An imaging optical system 1000 according to a tenth embodiment of the present invention will be described with reference to FIGS. 19 and 20 .

An imaging optical system 1000 according to a tenth embodiment of the present invention includes a first lens 910, a second lens 920, a third lens 930, a fourth lens 940, a fifth lens 950, It includes an optical system including a sixth lens 960, a seventh lens 970, and an eighth lens 980, and may further include a filter 990 and an image sensor IS.

The imaging optical system 1000 according to the tenth embodiment of the present invention may form a focus on the imaging surface 991 . The imaging surface 991 may mean a surface on which a focus is formed by an imaging optical system. For example, the imaging surface 991 may refer to one surface of the image sensor IS through which light is received.

Table 19 shows the lens characteristics of each lens (radius of curvature, thickness of the lens or distance between lenses, index of refraction, Abbe number, focal length).

side number note radius of curvature thickness or distance refractive index Abe number focal length S1 1st lens 2.572 0.784 1.544 56.0 7.1 S2 6.812 0.025 S3 2nd lens 5.290 0.220 1.680 18.2 -16.3 S4 3.535 0.188 S5 3rd lens 5.385 0.516 1.535 55.7 18.2 S6 11.583 0.267 S7 4th lens 76.309 0.250 1.567 37.4 124.58 S8 -1041.521 0.461 S9 5th lens 83.881 0.317 1.680 18.2 -32.83 S10 17.793 0.445 S11 6th lens 16.668 0.340 1.635 24.0 2934.33 S12 16.683 0.600 S13 7th lens 4.783 0.551 1.567 37.4 13.81 S14 11.662 1.177 S15 8th lens 10.464 0.481 1.544 56.0 -6.16 S16 2.504 0.337 S17 filter Infinity 0.110 1.517 64.2 S18 Infinity 0.770 S19 imaging plane Infinity

Meanwhile, the total focal length f of the imaging optical system 1000 according to the tenth embodiment of the present invention is 7.24 mm, IMG HT is 7.145 mm, FOV is 87.2 °, SAG52 is -0.460 mm, and SAG62 is -0.904 mm, SAG72 is -1.550 mm, and SAG82 is -1.762 mm.

In the tenth embodiment of the present invention, the first lens 1010 has positive refractive power, the first surface of the first lens 1010 is convex, and the second surface of the first lens 1010 is concave. .

The second lens 1020 has negative refractive power, the first surface of the second lens 1020 is convex, and the second surface of the second lens 1020 is concave.

The third lens 1030 has positive refractive power, a first surface of the third lens 1030 is convex, and a second surface of the third lens 1030 is concave.

The fourth lens 1040 has a positive refractive power, and the first and second surfaces of the fourth lens 1040 are convex.

The fifth lens 1050 has negative refractive power, a first surface of the fifth lens 1050 is convex, and a second surface of the fifth lens 1050 is concave.

The sixth lens 1060 has positive refractive power, a first surface of the sixth lens 1060 is convex, and a second surface of the sixth lens 1060 is concave.

In addition, at least one inflection point is formed on at least one of the first surface and the second surface of the sixth lens 1060 . For example, the first surface of the sixth lens 1060 may be convex in the paraxial region and concave in parts other than the paraxial region. The second surface of the sixth lens 1060 may be concave in the paraxial region and convex in parts other than the paraxial region.

The seventh lens 1070 has positive refractive power, a first surface of the seventh lens 1070 is convex in the paraxial region, and a second surface of the seventh lens 1070 is concave in the paraxial region.

In addition, at least one inflection point is formed on at least one of the first and second surfaces of the seventh lens 1070 . For example, the first surface of the seventh lens 1070 may be convex in the paraxial region and concave in parts other than the paraxial region. The second surface of the seventh lens 1070 may be concave in the paraxial region and convex in parts other than the paraxial region.

The eighth lens 1080 has negative refractive power, a first surface of the eighth lens 1080 is convex in the paraxial region, and a second surface of the eighth lens 1080 is concave in the paraxial region.

In addition, at least one inflection point is formed on at least one of the first and second surfaces of the eighth lens 1080 . For example, the first surface of the eighth lens 1080 may be convex in the paraxial region and concave in parts other than the paraxial region. The second surface of the eighth lens 1080 may be concave in the paraxial region and convex in parts other than the paraxial region.

Meanwhile, each surface of the first lens 1010 to the eighth lens 1080 has an aspherical surface coefficient as shown in Table 20. For example, both the object-side surface and the image-side surface of the first lens 1010 to the eighth lens 1080 are aspheric surfaces.

S1 S2 S3 S4 S5 S6 S7 S8 Conic constant (K) -1.390 10.550 -10.251 -4.372 0.395 -9.947 -98.568 99.000 4th order coefficient (A) 7.335E-03 -5.012E-03 -2.603E-03 -3.761E-03 -9.013E-03 -1.748E-02 -1.374E-02 -2.254E-02 6th order coefficient (B) 5.061E-03 1.771E-02 3.239E-02 3.364E-02 3.613E-02 8.713E-02 -6.288E-02 5.776E-02 8th order coefficient (C) -1.224E-02 -3.259E-02 -8.758E-02 -1.195E-01 -1.281E-01 -4.156E-01 3.488E-01 -3.103E-01 Tenth order coefficient (D) 2.714E-02 7.002E-02 2.231E-01 3.332E-01 3.204E-01 1.254E+00 -1.150E+00 1.049E+00 12th order coefficient (E) -4.819E-02 -1.942E-01 -4.808E-01 -6.615E-01 -5.185E-01 -2.522E+00 2.539E+00 -2.291E+00 14th order coefficient (F) 6.113E-02 3.513E-01 7.204E-01 9.098E-01 5.478E-01 3.553E+00 -3.906E+00 3.439E+00 16th order coefficient (G) -5.435E-02 -3.955E-01 -7.304E-01 -8.736E-01 -3.643E-01 -3.600E+00 4.301E+00 -3.676E+00 18th order coefficient (H) 3.414E-02 2.935E-01 5.110E-01 5.922E-01 1.279E-01 2.656E+00 -3.436E+00 2.851E+00 20th order coefficient (J) -1.523E-02 -1.489E-01 -2.502E-01 -2.843E-01 5.213E-03 -1.428E+00 1.997E+00 -1.612E+00 22nd Coefficient (L) 4.803E-03 5.214E-02 8.572E-02 9.575E-02 -2.949E-02 5.533E-01 -8.365E-01 6.600E-01 24th order coefficient (M) -1.047E-03 -1.245E-02 -2.017E-02 -2.203E-02 1.506E-02 -1.503E-01 2.460E-01 -1.906E-01 26th Coefficient (N) 1.501E-04 1.938E-03 3.111E-03 3.283E-03 -3.910E-03 2.713E-02 -4.822E-02 3.691E-02 28th order coefficient (O) -1.274E-05 -1.777E-04 -2.833E-04 -2.835E-04 5.409E-04 -2.922E-03 5.657E-03 -4.304E-03 30th order coefficient (P) 4.850E-07 7.288E-06 1.156E-05 1.066E-05 -3.173E-05 1.420E-04 -3.003E-04 2.287E-04 S9 S10 S11 S12 S13 S14 S15 S16 Conic constant (K) 99.000 1.255 -97.029 -29.474 1.130 -0.838 -0.016 -10.831 4th order coefficient (A) -5.052E-02 -5.610E-02 -6.227E-02 -8.311E-02 -6.392E-02 -4.241E-02 -1.304E-01 -6.624E-02 6th order coefficient (B) 7.639E-02 1.068E-01 5.049E-02 6.226E-02 1.147E-02 1.720E-02 5.537E-02 2.741E-02 8th order coefficient (C) -3.391E-01 -3.792E-01 -3.971E-02 -3.401E-02 9.115E-03 -1.332E-02 -1.814E-02 -8.175E-03 Tenth order coefficient (D) 1.116E+00 9.310E-01 2.390E-02 -9.904E-03 -2.166E-02 8.466E-03 4.358E-03 1.732E-03 12th order coefficient (E) -2.595E+00 -1.555E+00 -2.405E-02 4.373E-02 2.136E-02 -3.870E-03 -7.407E-04 -2.623E-04 14th order coefficient (F) 4.270E+00 1.805E+00 3.493E-02 -4.832E-02 -1.320E-02 1.218E-03 9.004E-05 2.866E-05 16th order coefficient (G) -5.021E+00 -1.486E+00 -3.776E-02 3.159E-02 5.521E-03 -2.566E-04 -7.955E-06 -2.274E-06 18th order coefficient (H) 4.248E+00 8.775E-01 2.674E-02 -1.375E-02 -1.607E-03 3.434E-05 5.158E-07 1.310E-07 20th order coefficient (J) -2.587E+00 -3.727E-01 -1.255E-02 4.124E-03 3.283E-04 -2.441E-06 -2.454E-08 -5.415E-09 22nd Coefficient (L) 1.122E+00 1.127E-01 3.946E-03 -8.562E-04 -4.674E-05 -6.507E-09 8.463E-10 1.566E-10 24th order coefficient (M) -3.377E-01 -2.365E-02 -8.204E-04 1.208E-04 4.536E-06 1.832E-08 -2.059E-11 -3.022E-12 26th Coefficient (N) 6.702E-02 3.269E-03 1.079E-04 -1.106E-05 -2.856E-07 -1.660E-09 3.349E-13 3.543E-14 28th order coefficient (O) -7.881E-03 -2.674E-04 -8.115E-06 5.917E-07 1.051E-08 6.706E-11 -3.269E-15 -2.044E-16 30th order coefficient (P) 4.158E-04 9.789E-06 2.645E-07 -1.405E-08 -1.717E-10 -1.078E-12 1.447E-17 2.552E-19

Also, the imaging optical system configured as described above may have aberration characteristics shown in FIG. 20 .

In the above, the configuration and characteristics of the present invention have been described based on the embodiments according to the present invention, but the present invention is not limited thereto, and various changes or modifications can be made within the spirit and scope of the present invention. It will be apparent to those skilled in the art, and therefore such changes or modifications are intended to fall within the scope of the appended claims.

110, 210, 310, 410, 510, 610, 710, 810, 910, 1010: first lens
120, 220, 320, 420, 520, 620, 720, 820, 920, 1020: second lens
130, 230, 330, 430, 530, 630, 730, 830, 930, 1030: third lens
140, 240, 340, 440, 540, 640, 740, 840, 940, 1040: 4th lens
150, 250, 350, 450, 550, 650, 750, 850, 950, 1050: 5th lens
160, 260, 360, 460, 560, 660, 760, 860, 960, 1060: sixth lens
170, 270, 370, 470, 570, 670, 770, 870, 970, 1070: 7th lens
180, 280, 380, 480, 580, 680, 780, 880, 980, 1080: 8th lens
190, 290, 390, 490, 590, 690, 790, 890, 990, 1090: filter

Claims (16)

A first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, and an eighth lens arranged in order from the object side;
The first lens has a positive refractive power, the second lens has a negative refractive power,
At least three of the first to eighth lenses have a refractive index of 1.61 or more;
Satisfies (TTL/(2×IMG HT))×(TTL/f) < 0.64,
TTL is the distance on the optical axis from the object side surface of the first lens to the imaging surface, IMG HT is half of the diagonal length of the imaging surface, and f is the total focal length of the first lens to the eighth lens.
According to claim 1,
The second lens has a refractive index of 1.61 or more,
Among the at least three lenses having the refractive index of 1.61 or more, the second lens has the smallest absolute value of the focal length.
According to claim 1,
25 < v1-v2 <45; 15 < v1-v4 <40; and 15 < v1-(v6 + v7) / 2 < 30,
v1 is the Abbe number of the first lens, v2 is the Abbe number of the second lens, v4 is the Abbe number of the fourth lens, v6 is the Abbe number of the sixth lens, and v7 is the Abbe number of the seventh lens Abesuin imaging optics in .
According to claim 1,
0 < f1/f < 1.4, and f1 is the focal length of the first lens.
According to claim 1,
-3<f2/f<0, where f2 is the focal length of the second lens.
According to claim 1,
1 < f3/f < 6, and f3 is the focal length of the third lens.
According to claim 1,
0 < f7/(10×f) < 5, and f7 is the focal length of the seventh lens.
According to claim 1,
-3 < f8/f < 0, and f8 is the focal length of the eighth lens.
According to claim 1,
TTL/f <1.2; and BFL/f <0.3;
BFL is the distance on the optical axis from the image side surface of the eighth lens to the imaging surface.
According to claim 1,
The imaging optical system satisfies 70°<FOV×(IMG HT/f)<100°, and FOV is an angle of view of the imaging optical system.
According to claim 1,
-0.2 < SAG52/TTL < 0 is satisfied, and SAG52 is a SAG value at an end of an effective mirror on an image side surface of the fifth lens.
According to claim 1,
-0.2 < SAG62/TTL < 0, and SAG62 is a SAG value at an end of an effective mirror on the image side surface of the sixth lens.
According to claim 1,
-0.3 < SAG72/TTL < 0, and SAG72 is the SAG value at the end of the effective mirror of the image side surface of the seventh lens.
According to claim 1,
-0.3 < SAG82/TTL < 0, and SAG82 is a SAG value at an end of an effective mirror on the image side surface of the eighth lens.

According to claim 1,
5 < |Y72/Z72| <100; and 5 < |Y82/Z82| <30; satisfies at least one of
Y72 is the vertical height between the optical axis and the first inflection point of the image side of the seventh lens, Y82 is the vertical height between the optical axis and the first inflection point of the image side of the eighth lens, and Z72 is the vertical height of the image side of the seventh lens. a Sag value at a first inflection point of the surface, and Z82 is a Sag value at a first inflection point of the image side surface of the eighth lens.
According to claim 1,
The third lens has positive refractive power, the fourth lens has positive refractive power, the fifth lens has negative refractive power, the seventh lens has positive refractive power, and the eighth lens has negative refractive power. optics.

Images