KR20200128616A - Optical Imaging System - Google Patents

Abstract

According to the present invention, an optical imaging system comprises: a first lens having a refractive force; and an upper surface forming an image formation surface of incident light of the first lens. An effective diameter of the first lens is larger than a diagonal length (2Y) of the upper surface, and a distance (TTL) between an object side surface of the first lens and the upper surface is less than or equal to 6.5 mm. The optical imaging system can be easily manufactured while having high resolution.

Description

Optical Imaging System {Optical Imaging System}

The present invention relates to an optical system that can be mounted on a portable terminal.

The portable terminal includes a small camera and an imaging optical system constituting the small camera. The optical system for a portable terminal has a large spatial limitation, so it is difficult to implement a high resolution and bright F-number.

In order to minimize these problems, an optical system including four or more lenses is used. However, an optical system comprising a plurality of lenses is not easy to manufacture, and many defects occur during the manufacturing process.

An object of the present invention is to provide an imaging optical system that is easy to manufacture while implementing a high resolution.

The optical system according to the present invention includes a first lens having refractive power; And an image surface constituting an imaging surface of light incident by the first lens, wherein the effective diameter of the first lens is greater than the diagonal length (2Y) of the first lens, The distance to the upper surface (TTL) is 6.5 mm or less.

In the optical system according to the present invention, the first lens has a positive refractive power.

In the optical system according to the present invention, at least one of the object side and the image side of the first lens has an aspherical shape.

In the optical system according to the present invention, the first lens has a convex object side.

The optical system according to the present invention satisfies the conditional expression 0.7 <TTL/f <1.2 (in the conditional expression, f is the focal length of the optical system).

In the optical system according to the present invention, the focal length f1 of the first lens satisfies the conditional expression 0.8 <f1/f <1.1.

The optical system according to the present invention further includes a second lens having refractive power.

In the optical system according to the present invention, the radius of curvature (R2) of the image side of the first lens and the radius of curvature (R3) of the side of the object of the second lens are the conditional expression -1.0 <(R2-R3)/(R2+R3) <1.0 is satisfied.

The optical system according to the present invention is easily miniaturized and manufactured.

1 is a configuration diagram of an optical system according to a first embodiment of the present invention
2 is a configuration diagram of an optical system according to a second embodiment of the present invention
3 is a configuration diagram of an optical system according to a third embodiment of the present invention
4 is a configuration diagram of an optical system according to a fourth embodiment of the present invention
5 is a configuration diagram of an optical system according to a fifth embodiment of the present invention
6 is a configuration diagram of an optical system according to a sixth embodiment of the present invention
7 is a configuration diagram of an optical system according to a seventh embodiment of the present invention
8 is a configuration diagram of an optical system according to an eighth embodiment of the present invention

Hereinafter, a preferred embodiment of the present invention will be described in detail on the basis of the accompanying drawings.

In the following description of the present invention, terms referring to the constituent elements of the present invention are named in consideration of the functions of the respective constituent elements, so they should not be understood as limiting the technical constituents of the present invention.

The optical system according to the present invention is composed of three or less lenses to simplify the manufacturing process. In addition, the optical system has an effective diameter of the lens disposed closest to the object side than the diagonal length of the image surface so as to implement a low f-number. In addition, the optical system has a distance TTL of 6.5 mm or less from the object side to the image surface of the lens disposed closest to the object side so that it can be easily mounted on the portable terminal.

The imaging optical system includes one or more lenses. For example, the optical system may include a first lens having positive refractive power. In addition, the optical system may include a filter for blocking infrared rays and an image sensor for forming an imaging surface.

The optical system according to the present invention satisfies at least one of the following conditional expressions.

[Conditional Expression 1] 0.7 <TTL/f <1.2

[Conditional Expression 2] 0.8 <f1/f <1.1

[Conditional Expression 3] -1.0 <(R2-R3)/(R2+R3) <1.0

In the above conditional equation, TTL is the distance from the object side to the image surface of the lens (first lens) arranged closest to the object side, f is the focal length of the imaging optical system, f1 is the focal length of the first lens, and R2 is the first lens. 1 is the radius of curvature of the image side of the lens, and R3 is the radius of curvature of the object side of the second lens.

Hereinafter, an optical system according to various embodiments of the present disclosure will be described.

First, an optical system according to a first embodiment will be described with reference to FIG. 1.

The optical system 10 according to the present embodiment includes a first lens 101, a filter 301, and an image sensor 401.

The first lens 101 has positive refractive power. The first lens 101 has a convex object side and a convex image side. The first lens 101 may be made of plastic or glass. In addition, one surface of the first lens 101 may be an aspherical surface. However, one surface of the first lens 101 does not necessarily have to be an aspherical surface. The first lens 101 is made of a material having a high Abbe number. For example, the Abbe number of the first lens 101 may be 50 or more.

The F-number of the imaging optical system 10 according to the present embodiment is 1.06, the focal length f of the imaging optical system is 5.109 mm, the total length TTL of the imaging optical system is 5.10 mm, and the diagonal length of the image surface (2Y) ) Is 3.5 mm.

Table 1 shows the lens properties of the optical system in this embodiment.

Remark Radius of curvature Thickness/distance Refractive index Abbesu Focal length First lens 5.250 2.5 1.546 56.11 5.109 -4.950 2.0 filter infinity 0.1 1.519 64.20 infinity 0.5 Top infinity

An optical system according to a second embodiment will be described with reference to FIG. 2.

The optical system 20 according to the present embodiment includes a first lens 102, a filter 302, and an image sensor 402.

The first lens 102 has positive refractive power. The first lens 102 has a convex object side and a convex image side. The first lens 102 may be made of plastic or glass. In addition, one surface of the first lens 102 may be an aspherical surface. However, one surface of the first lens 102 does not necessarily have to be an aspherical surface. The first lens 102 is made of a material having a high Abbe number. For example, the Abbe number of the first lens 102 may be 50 or more.

The F-number of the imaging optical system 20 according to the present embodiment is 1.08, the focal length f of the imaging optical system is 5.198 mm, the total length TTL of the imaging optical system is 5.20 mm, and the diagonal length of the image surface (2Y) ) Is 3.5 mm.

Table 2 shows the lens properties of the optical system in this embodiment.

Remark Radius of curvature Thickness/distance Refractive index Abbesu Focal length First lens 5.20 2.7 1.546 56.11 5.198 -5.10 1.9 filter infinity 0.1 1.519 64.20 infinity 0.5 Top infinity

An optical system according to a third embodiment will be described with reference to FIG. 3.

The optical system 30 according to the present embodiment includes a first lens 103, a filter 303, and an image sensor 403.

The first lens 103 has positive refractive power. The first lens 103 has a convex object side and a convex image side. The first lens 103 may be made of plastic or glass. In addition, one surface of the first lens 103 may be an aspherical surface. However, one surface of the first lens 103 does not necessarily have to be an aspherical surface. The first lens 103 is made of a material having a high Abbe number. For example, the Abbe number of the first lens 103 may be 50 or more.

The F-number of the imaging optical system 30 according to the present embodiment is 1.12, the focal length f of the imaging optical system is 5.391 mm, the total length TTL of the imaging optical system is 5.40 mm, and the diagonal length of the image plane (2Y ) Is 3.5 mm.

Table 3 shows the lens properties of the optical system in this embodiment.

Remark Radius of curvature Thickness/distance Refractive index Abbesu Focal length First lens 5.40 3.0 1.546 56.11 5.391 -5.20 1.8 filter infinity 0.1 1.519 64.20 infinity 0.5 Top infinity

An optical system according to a fourth embodiment will be described with reference to FIG. 4.

The optical system 40 according to the present embodiment includes a first lens 104, a filter 304, and an image sensor 404.

The first lens 104 has positive refractive power. The first lens 104 has a convex object side and a convex image side. The first lens 104 may be made of plastic or glass. In addition, one surface of the first lens 104 may be an aspherical surface. However, one surface of the first lens 104 does not necessarily have to be an aspherical surface. The first lens 104 is made of a material having a high Abbe number. For example, the Abbe number of the first lens 104 may be 50 or more.

The F-number of the imaging optical system 40 according to the present embodiment is 1.15, the focal length f of the imaging optical system is 5.981 mm, the total length TTL of the imaging optical system is 6.00 mm, and the diagonal length of the image plane (2Y ) Is 3.5 mm.

Table 4 shows the lens properties of the optical system in this embodiment.

Remark Radius of curvature Thickness/distance Refractive index Abbesu Focal length First lens 6.350 3.0 1.546 56.11 5.981 -5.600 2.4 filter infinity 0.1 1.519 64.20 infinity 0.5 Top infinity

An optical system according to a fifth embodiment will be described with reference to FIG. 5.

The optical system 50 according to the present embodiment includes a first lens 105, a second lens 206, a filter 305, and an image sensor 405.

The first lens 105 has positive refractive power. The first lens 105 has a convex object side and a convex image side. The first lens 105 may be made of plastic or glass. In addition, one surface of the first lens 105 may be an aspherical surface. However, one surface of the first lens 105 does not necessarily have to be an aspherical surface. The first lens 105 is made of a material having a high Abbe number. For example, the Abbe number of the first lens 105 may be 50 or more.

The second lens 205 has positive refractive power. The second lens 105 has a concave object side surface and a convex image side surface. The second lens 205 may be made of plastic or glass. In addition, one surface of the second lens 205 may be an aspherical surface. However, one surface of the second lens 205 does not necessarily have to be an aspherical surface. The second lens 205 is made of a material having a lower Abbe number than the first lens. For example, the Abbe number of the second lens 205 may be 30 or less.

The F-number of the imaging optical system 50 according to the present embodiment is 1.22, the focal length f of the imaging optical system is 5.84 mm, the total length TTL of the imaging optical system is 5.90 mm, and the diagonal length of the image surface (2Y) ) Is 3.5 mm.

Table 5 shows the lens properties of the optical system in this embodiment.

Remark Radius of curvature Thickness/distance Refractive index Abbesu Focal length First lens
5.20 2.5 1.55 56.1 5.615 -6.20 0.5 Second lens -8.20 2.0 1.67 20.4 61.253 -7.50 0.8 filter infinity 0.1 1.52 64.2 infinity 0.5 Top infinity

An optical system according to a sixth embodiment will be described with reference to FIG. 6.

The first lens 106 has positive refractive power. The first lens 106 has a convex object side and a convex image side. The first lens 106 may be made of plastic or glass. In addition, one surface of the first lens 106 may be an aspherical surface. However, one surface of the first lens 106 does not necessarily have to be an aspherical surface. The first lens 106 is made of a material having a high Abbe number. For example, the Abbe number of the first lens 106 may be 50 or more.

The second lens 206 has positive refractive power. The second lens 106 has a concave object side and a convex image side. The second lens 206 may be made of plastic or glass. In addition, one surface of the second lens 206 may be an aspherical surface. However, one surface of the second lens 206 does not necessarily have to be an aspherical surface. The second lens 206 is made of a material having a lower Abbe number than the first lens. For example, the Abbe number of the second lens 206 may be 30 or less.

The F-number of the imaging optical system 60 according to the present embodiment is 1.17, the focal length f of the imaging optical system is 5.87 mm, the total length TTL of the imaging optical system is 5.90 mm, and the diagonal length of the image surface (2Y) ) Is 3.5 mm.

Table 6 shows the lens properties of the optical system in this embodiment.

Remark Radius of curvature Thickness/distance Refractive index Abbesu Focal length First lens
5.10 2.5 1.55 56.1 5.892 -7.20 0.5 Second lens -8.10 1.6 1.67 20.4 45.395 -6.90 1.2 filter infinity 0.1 1.52 64.2 infinity 0.5 Top infinity

An optical system according to a seventh embodiment will be described with reference to FIG. 7.

The first lens 107 has positive refractive power. The first lens 107 has a convex object side and a convex image side. The first lens 107 may be made of plastic or glass. In addition, one surface of the first lens 107 may be an aspherical surface. However, one surface of the first lens 107 does not necessarily have to be an aspherical surface. The first lens 107 is made of a material having a high Abbe number. For example, the Abbe number of the first lens 107 may be 50 or more.

The second lens 207 has negative refractive power. The second lens 107 has a concave object side surface and a convex image side surface. The second lens 207 may be made of plastic or glass. In addition, one surface of the second lens 207 may be an aspherical surface. However, one surface of the second lens 207 does not necessarily have to be an aspherical surface. The second lens 207 is made of a material having a lower Abbe number than the first lens. For example, the Abbe number of the second lens 207 may be 30 or less.

The F-number of the imaging optical system 70 according to the present embodiment is 1.16, the focal length f of the imaging optical system is 5.82 mm, the total length TTL of the imaging optical system is 6.00 mm, and the diagonal length of the image surface (2Y) ) Is 3.5 mm.

Table 7 shows the lens properties of the optical system in this embodiment.

Remark Radius of curvature Thickness/distance Refractive index Abbesu Focal length First lens
5.0 2.6 1.55 56.1 5.298 -5.6 0.5 Second lens -5.8 1.4 1.67 20.4 -1424.2 -6.4 1.4 filter infinity 0.1 1.52 64.2 infinity 0.5 Top infinity

An optical system according to an eighth embodiment will be described with reference to FIG. 8.

The first lens 108 has positive refractive power. The first lens 108 has a convex object side and a concave image side. The first lens 108 may be made of plastic or glass. In addition, one surface of the first lens 108 may be an aspherical surface. However, one surface of the first lens 108 does not necessarily have to be an aspherical surface. The first lens 108 is made of a material having a high Abbe number. For example, the Abbe number of the first lens 108 may be 50 or more.

The second lens 208 has negative refractive power. The second lens 108 has a convex object side and a concave image side. The second lens 208 may be made of plastic or glass. In addition, one surface of the second lens 208 may be an aspherical surface. However, one surface of the second lens 208 does not necessarily have to be an aspherical surface. The second lens 208 is made of a material having a lower Abbe number than the first lens. For example, the Abbe number of the second lens 208 may be 30 or less.

The F-number of the imaging optical system 80 according to the present embodiment is 1.17, the focal length f of the imaging optical system is 5.76 mm, the total length TTL of the imaging optical system is 5.60 mm, and the diagonal length of the image surface (2Y) ) Is 3.5 mm.

Table 8 shows the lens properties of the optical system in this embodiment.

Remark Radius of curvature Thickness/distance Refractive index Abbesu Focal length First lens
2.8 2.4 1.55 56.1 5.462 32.0 0.5 Second lens 14.2 1.2 1.67 20.4 -29.7 8.0 1.4 filter infinity 0.1 1.52 64.2 infinity 0.5 Top infinity

The present invention is not limited only to the embodiments described above, and those of ordinary skill in the art to which the present invention pertains, within the scope not departing from the spirit of the technical idea of the present invention described in the following claims. It can be implemented with various changes.

10, 20, 30, 40, 50, 60, 70, 80 optical system
101, 102, 103, 104, 105, 106, 107, 108 first lens
205, 206, 207, 208 second lens
301, 302, 303, 304, 305, 306, 307, 308 filter
401, 402, 403, 404, 405, 406, 407, 408 image sensor

Claims (8)

A first lens having refractive power; And
An image surface constituting an imaging surface of light incident by the first lens;
Including,
The effective diameter of the first lens is larger than the diagonal length (2Y) of the image surface,
An optical system having a distance TTL of 6.5 mm or less from the object side of the first lens to the image surface. The method of claim 1,
The first lens is an optical system having a positive refractive power. The method of claim 1,
The first lens is an optical system in which at least one of an object side and an image side has an aspherical shape. The method of claim 1,
The first lens is an optical system having a convex object side. The method of claim 1,
An imaging optical system that satisfies the following conditional expression.
0.7 <TTL/f <1.2
(In the above conditional formula, f is the focal length of the optical system) The method of claim 5,
The focal length f1 of the first lens satisfies the following conditional expression.
0.8 <f1/f <1.1 The method of claim 1,
An optical system further comprising a second lens having refractive power. The method of claim 6,
An optical system in which a radius of curvature R2 of an image side of the first lens and a radius of curvature R3 of an object side of the second lens satisfy the following conditional expression.
-1.0 <(R2-R3)/(R2+R3) <1.0

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