KR20210157753A - Cemented lens, lens optical system and Imaging Apparatus - Google Patents

Abstract

A bonding lens, a lens optical system, and an imaging device are disclosed. The disclosed lens optical system comprises first to eighth lenses arranged in order from an object side to an image plane side. The first lens, the third lens, and the fifth lens are formed of plastic, the second lens and the fourth lens are formed of an optical bonding material, and the optical bonding material of the second lens and the optical bonding material of the fourth lens are filled in the space between the first lens and the third lens and the space between the third lens and the fifth lens, respectively, so that a first group of junction lenses in which the first lens, third lens, and fifth lens are bonded by the bonding force of the second lens and fourth lens is formed. The refractive index of the second lens and the refractive index of the fourth lens are different from the refractive index of the first lens, the refractive index of the third lens, and the refractive index of the fifth lens. At least one of the incident surface of the first lens, a first interface between the first and second lenses, a second interface between the second lens and the third lens, a third interface between the third lens and the fourth lens, and a fourth interface between the fourth lens and the fifth lens, and an exit surface of the fifth lens is an aspherical surface. The first interface and the second interface have different shapes, and the third interface and the fourth interface have different shapes. The present invention can implement the ultra-slim bonding lens and lens optical system while securing optical performance.

Description

Cemented lens, lens optical system and Imaging Apparatus

The present disclosure relates to a bonding lens, a lens optical system, and an imaging device.

Recently, the field of dissemination and use of a camera (imaging device) using a solid-state imaging device such as a complementary metal oxide semiconductor image sensor (CMOS image sensor) or a charge coupled device (CCD) is rapidly expanding. is becoming

In order to increase the resolution of a camera, the pixel integration degree of a solid-state image sensor is increasing. At the same time, the miniaturization and weight reduction of the camera is progressing by improving the performance of the lens optical system built into the camera. Since these cameras are suitable for miniaturization, they are being applied to mobile devices such as mobile phones. Cameras used in mobile devices such as mobile phones require ultra-small size and high performance comparable to digital single-lens reflex cameras (DSL cameras). Accordingly, a lens optical system for a camera used in a mobile device uses an aspherical lens to realize compact and high performance. Recently, as the thickness of a mobile device is getting thinner, an optical system for a camera lens applied to a mobile device is also required to be ultra-slim in a high pixel. However, there is a limitation in realizing compact optical performance by applying the conventional method of assembling the aspherical lenses to the barrel, for example, by applying to an ultra-high-pixel sensor of 64M or more pixels.

An object to be solved is to provide a junction lens and a lens optical system that can secure optical performance while being ultra-slim.

An object to be solved is to provide an ultra-thin imaging device by implementing an optical system in a compact manner.

The technical problem to be solved is not limited to the technical problems as described above, and other technical problems may exist.

In one aspect, the lens optical system includes first to eighth lenses arranged in order from the object side to the image plane side, the first lens, the third lens, and the fifth lens are made of plastic, and the second lens and the fourth lens are made of plastic. The lens is formed of an optical bonding material, and the optical bonding material of the second lens and the optical bonding material of the fourth lens are filled in the space between the first lens and the third lens and the space between the third lens and the fifth lens, respectively. The first lens, the third lens, and the fifth lens form a group of bonded lenses joined by the bonding force of the second and fourth lenses, and the refractive index of the second lens and the refractive index of the fourth lens are the refractive index of the first lens. , different from the refractive index of the third lens and the refractive index of the fifth lens, the incident surface of the first lens, the first interface between the first lens and the second lens, the second interface between the second lens and the third lens, the third At least one of the third interface between the lens and the fourth lens, the fourth interface between the fourth lens and the fifth lens, and the exit surface of the fifth lens is an aspherical surface, and the first interface and the second interface have different shapes , and the third boundary surface and the fourth boundary surface may have different shapes.

In example embodiments, the lens optical system may satisfy at least one of the following conditional expressions:

Conditional Expression (1): 0.01 ≤ ThiL2 ≤ 0.1

Conditional Expression (2): 0.01 ≤ ThiL4 ≤ 0.1

Here, ThilL2 represents the thickness of the second lens, and ThilL4 represents the thickness of the fourth lens.

In example embodiments, the lens optical system may satisfy at least one of the following conditional expressions:

Conditional Expression (3): 1.4 ≤ Ind2 ≤ 1.8

Conditional Expression (4): 1.4 ≤ Ind4 ≤ 1.8

Here, Ind2 represents the refractive index of the second lens, and Ind4 represents the refractive index of the fourth lens.

In example embodiments, the lens optical system may satisfy at least one of the following conditional expressions:

Conditional Expression (5): 0.15 ≤ OAL_L1toL5/OAL ≤ 0.25

Conditional expression (6): 0.1 ≤ OAL_L1toL5/IH ≤ 0.2

Here, OAL_L1toL5 (unit: mm) represents the distance between the center of the incident surface of the first lens and the center of the exit surface of the fifth lens, and OAL (unit: mm) is the center of the incident surface of the first lens and the eighth lens. represents the distance between the centers of the exit surfaces of , and IH (unit: mm) represents the height of the effective diameter.

In example embodiments, the lens optical system may satisfy at least one of the following conditional expressions:

Conditional expression (7): 0.55 ≤ TTL/IH ≤ 0.8

Conditional expression (8): 70 ≤ Fov ≤ 90

Here, TTL (unit: mm) indicates the distance from the center of the incident surface of the first lens to the image surface, and FOV (unit: °) indicates the angle of view of the lens optical system.

In exemplary embodiments, the junction lens has positive refractive power, the sixth lens has negative refractive power, the seventh lens has negative refractive power, and the eighth lens has negative refractive power. It can have a refractive power of (-).

In exemplary embodiments, the bonding lens may be an aspherical lens having an incident surface convex toward the object.

In example embodiments, the sixth lens may be an aspherical lens.

In example embodiments, at least one of the seventh lens and the eighth lens may be an aspherical lens having two or more inflection points.

In another aspect, the lens optical system is arranged in order from the object side to the image plane side, has a positive (+) refractive power, and consists of a focusing lens consisting of first to fifth lenses; a sixth lens having negative (-) refractive power; a seventh lens having a negative refractive power; and an eighth lens having negative (-) refractive power, wherein the second lens and the fourth lens are formed of an optical bonding material, and the optical bonding material of the second lens and the optical bonding material of the fourth lens include the first A group of groups filled in the space between the lens and the third lens and the space between the third lens and the fifth lens, respectively, in which the first lens, the third lens, and the fifth lens are joined by the bonding force of the second lens and the fourth lens forming a junction lens, wherein the refractive index of the second lens and the refractive index of the fourth lens are different from the refractive index of the first lens, the refractive index of the third lens, and the refractive index of the fifth lens It may be a lens.

In another aspect, the bonding lens includes a first lens, a second lens, a third lens, a fourth lens, and a fifth lens, wherein the first lens, the third lens, and the fifth lens are formed of plastic, The second lens and the fourth lens are formed of an optical bonding material, and the optical bonding material of the second lens and the optical bonding material of the fourth lens are formed in a space between the first lens and the third lens and between the third lens and the fifth lens. Each space is filled to form a group of junction lenses in which the first lens, the third lens, and the fifth lens are joined by the adhesive force of the second and fourth lenses, and the refractive index of the second lens and the refractive index of the fourth lens are The refractive index of the first lens, the refractive index of the third lens, and the refractive index of the fifth lens are different, the incident surface of the first lens, the first interface between the first lens and the second lens, the second lens between the second lens and the third lens At least one of the second interface, the third interface between the third lens and the fourth lens, the fourth interface between the fourth lens and the fifth lens, and the exit surface of the fifth lens is an aspherical surface, and the first interface and the second The boundary surface has different shapes, and the third boundary surface and the fourth boundary surface have different shapes, and the following conditions may be satisfied:

Conditional Expression (1): 0.01 ≤ ThiL2 ≤ 0.1

In another aspect, the imaging device includes a lens optical system and a solid-state imaging device for imaging an image formed by the lens optical system, wherein the lens optical system includes first to eighth lenses arranged in order from the object side to the image plane side. The first lens, the third lens, and the fifth lens are formed of plastic, the second lens and the fourth lens are formed of an optical bonding material, the optical bonding material of the second lens and the optical bonding material of the fourth lens The space between the first lens and the third lens and the space between the third lens and the fifth lens are respectively filled so that the first lens, the third lens, and the fifth lens are joined by the bonding force of the second lens and the fourth lens. A group of junction lenses is formed, wherein the refractive index of the second lens and the refractive index of the fourth lens are different from the refractive index of the first lens, the refractive index of the third lens, and the refractive index of the fifth lens, and the incident surface of the first lens, the first a first interface between the lens and the second lens, a second interface between the second lens and the third lens, a third interface between the third lens and the fourth lens, a fourth interface between the fourth lens and the fifth lens, and at least one of the exit surfaces of the fifth lens may be an aspherical surface, the first interface surface and the second interface surface may have different shapes, and the third interface surface and the fourth interface surface may have different shapes.

In another aspect, the imaging device includes a lens optical system and a solid-state imaging device for imaging an image formed by the lens optical system, the lens optical system being sequentially arranged from the object side to the image plane side, positive (+) a focusing lens having refractive power and consisting of first to fifth lenses; a sixth lens having negative (-) refractive power; a seventh lens having a negative refractive power; and an eighth lens having negative (-) refractive power, wherein the second lens and the fourth lens are formed of an optical bonding material, and the optical bonding material of the second lens and the optical bonding material of the fourth lens include the first A group of groups filled in the space between the lens and the third lens and the space between the third lens and the fifth lens, respectively, in which the first lens, the third lens, and the fifth lens are joined by the bonding force of the second lens and the fourth lens forming a junction lens, wherein the refractive index of the second lens and the refractive index of the fourth lens are different from the refractive index of the first lens, the refractive index of the third lens, and the refractive index of the fifth lens It may be a lens.

The bonding lens and lens optical system according to the present disclosure implement one group of bonding lenses by bonding two or more lenses, thereby maintaining high performance, and achieving ultra-small size and ultra-thin.

The lens optical system according to the present disclosure can be designed with low sensitivity while realizing high performance by dispersing power arrangement, so that mass productivity can be secured.

1 is a cross-sectional view schematically showing the arrangement of major components of a lens optical system according to a first embodiment.
FIG. 2 is a cross-sectional view schematically illustrating the bonding lens of FIG. 1 .
3A and 3E are views showing other examples of the lens end.
4 is a numerical diagram showing spherical aberration, field curvature, and distortion of the lens optical system according to the first embodiment.
5 is a cross-sectional view schematically showing the arrangement of major components of the lens optical system according to the second embodiment.
6 is a numerical diagram showing spherical aberration, field curvature, and distortion of the lens optical system according to the second embodiment.
7 is a cross-sectional view schematically showing the arrangement of major components of the lens optical system according to the third embodiment.
8 is a numerical diagram showing spherical aberration, field curvature, and distortion of the lens optical system according to the third embodiment.
9 is a perspective view schematically illustrating an imaging device including a lens optical system according to the present invention.

Hereinafter, a lens optical system and an imaging device according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. Like reference numerals refer to like (or similar) elements throughout the detailed description.

In the following description, the expression “image plane (IP)” refers to a plane on which an image is formed after passing through the lens optical system, and “image plane side” refers to an imaging device such as an image sensor, etc. direction can be indicated. Based on the lens optical system, “object side” and “image side” may mean opposite directions. In addition, a surface on the object side of the two surfaces of the lens may be referred to as an incident surface, and a surface on the image surface side may be referred to as an exit surface.

1 is a cross-sectional view schematically showing the arrangement of major components of the lens optical system according to the first embodiment, and FIG. 2 is a cross-sectional view schematically showing the bonding lens in FIG.

1 and 2 , the lens optical system includes first to eighth lenses L1 to L8 that are sequentially arranged from the object OBJ side to the image plane IP side.

The first lens L1 , the second lens L2 , the third lens L3 , the fourth lens L4 , and the fifth lens L5 form the junction lens CL. The first lens L1 , the third lens L3 , and the fifth lens L5 may be formed of plastic, and the second lens L2 and the fourth lens L4 may be formed of an optical bonding material. The optical bonding material 20 of the second lens L2 is filled in the space between the first lens L1 and the third lens L3 so that the first lens L1 and the third lens L3 are connected to the second lens ( It is bonded by the bonding force of L2 , and the optical bonding material 40 of the fourth lens L4 is filled in the space between the third lens L3 and the fifth lens L5 to form the third lens L3 and the fifth lens L5 . Since the lenses L5 are bonded by the bonding force of the fourth lens L4, a group of bonding lenses can be formed.

The bonding lens CL may be an aspherical lens having a positive (+) refractive power and having the incident surface 1 convex toward the object OBJ.

The first lens L1 and the third lens L3 may be spaced apart from each other by a predetermined interval. A predetermined distance between the first lens L1 and the third lens L3 becomes the thickness of the second lens L2. Similarly, the third lens L3 and the fifth lens L5 may be spaced apart from each other by a predetermined interval, and the predetermined interval between the third lens L3 and the fifth lens L5 is the fourth lens L4. is the thickness of That is, the thickness ThilL2 of the second lens L2 may be defined as a distance between the apex of the exit surface of the first lens L1 and the apex of the incident surface of the third lens L3, and the fourth lens L4 The thickness ThilL4 of may be defined as a distance between the apex of the exit surface of the third lens L3 and the vertex of the incident surface of the fifth lens L5. The thickness ThilL2 (unit: mm) of the second lens L2 and the thickness ThilL4 (unit: mm) of the fourth lens L4 may satisfy the following conditional expressions (1) and (2), respectively.

Conditional Expression (1): 0.01 ≤ ThiL2 ≤ 0.1

Conditional Expression (2): 0.01 ≤ ThiL4 ≤ 0.1

As the optical bonding material 20 of the second lens L2 is filled between the first lens L1 and the third lens L3, the exit surface of the first lens L1 is the The incident surface is the same, and the exit surface of the second lens (L2) is the same as the incident surface of the third lens (L3). Similarly, as the optical bonding material 40 of the fourth lens L4 is filled between the third lens L3 and the fifth lens L5, the exit surface of the third lens L3 is formed by the fourth lens L4 ), and the exit surface of the fourth lens L4 is the same as the incidence surface of the fifth lens L5. Hereinafter, the exit surface of the first lens L1 (ie, the incidence surface of the second lens L2) is the first interface 2, and the incidence surface of the third lens L3 (ie, the second lens L3) The exit surface of L2) is the second boundary surface 3, the exit surface of the third lens L3 (that is, the incidence surface of the fourth lens L4) is the third boundary surface 4, and the fifth lens ( The incident surface of L5 (that is, the exit surface of the fourth lens L4) will be described as the fourth boundary surface 5 . The mechanical structure of the bonding of the first to fifth lenses L1 to L5 will be described later.

As the first lens L1 and the third lens L3 are spaced apart, the first interface 2 and the second interface 3 may have different shapes. As the third lens L3 and the fifth lens L5 are spaced apart, the third interface 4 and the fourth interface 5 may also have different shapes. At least one of the first boundary surface 2, the second boundary surface 3, the third boundary surface 4, and the fourth boundary surface 5 may be an aspherical surface. For example, the first boundary surface 2 is an aspherical surface convex toward the object OBJ, and the second boundary surface 3 is also an aspherical surface convex toward the object OBJ, and the radius of curvature of the first boundary surface 2 And, the radius of curvature of the second interface 3 may be different from each other.

In addition, at least one of the incident surface 1 of the first lens L1 and the exit surface 6 of the fifth lens L5 may be an aspherical surface.

In one embodiment, the incident surface 1 of the first lens L1, the first interface 2, the second interface 3, the third interface 4, the fourth interface 5, and the fifth lens ( All of the exit surfaces 6 of L5) may be aspherical.

The refractive index of the second lens L2 is different from the refractive index of the first lens L1 and the refractive index of the third lens L2. Similarly, the refractive index of the fourth lens L4 is different from the refractive index of the third lens L3 and the refractive index of the fifth lens L5 .

The optical bonding material may be a material having excellent optical properties and having adhesive properties. The optical bonding material may be a UV curable or thermally curable material, taking into account the manufacturing process. The refractive index Ind2 of the second lens L2 and the refractive index Ind4 of the fourth lens L4 made of the optical bonding material may satisfy the following conditional expressions (3) and (4), respectively.

Conditional Expression (3): 1.4 ≤ Ind2 ≤ 1.8

Conditional Expression (4): 1.4 ≤ Ind4 ≤ 1.8

The bonding lens CL may satisfy the following conditional expression (5).

Conditional Expression (5): 0.15 ≤ OAL_L1toL5/OAL ≤ 0.25

Here, OAL_L1toL5 (unit: mm) represents the distance between the center of the incident surface 1 of the first lens L1 and the center of the exit surface 6 of the fifth lens L5, and the thickness of the junction lens CL corresponds to OAL (unit: mm) represents a distance between the center of the incident surface 1 of the first lens L1 and the center of the exit surface 12 of the eighth lens L8.

Conditional expression (5) shows the relationship between the thickness of the first to fifth lenses L1 to L5 and the thickness of the entire lens optical system, and as the thickness of the first to fifth lenses L1 to L5 is reduced, the lens It is possible to realize the lens optical system in an ultra-slim while maintaining the high performance of the optical system.

In addition, the bonding lens CL may satisfy the following conditional expression (6).

Conditional expression (6): 0.1 ≤ OAL_L1toL5/IH ≤ 0.2

Here, IH (unit: mm) represents the height of the image of the effective diameter (ie, the diameter of the image on the upper surface IP).

Conditional expression (6) shows the relationship between the thickness of the first to fifth lenses L1 to L5 and the size of the image plane IP, and as the thickness of the first to fifth lenses L1 to L5 is reduced, the image plane ( IP) compared to the size of the lens optical system can be implemented as ultra-slim.

As described above, the bonding lens CL may be a bonding lens of three optical lenses in a conventional sense, but an optical bonding material functioning as an adhesive therebetween is applied to the second lens L2 and the fourth lens L4. By making it possible to function as a junction lens consisting of a group of 5 elements, it is possible to make the entire length of the lens optical system ultra-slim. In addition, since the first to fifth lenses L1 to L5 are joined in a state in which air is not interposed, chromatic aberration may be corrected at a high level.

The sixth lens L6 has a negative refractive power and may be an aspherical lens. The sixth lens L6 may have, for example, a meniscus shape in which the image surface IP side is convex.

The seventh lens L7 may have a negative refractive power and may be an aspherical lens having two or more inflection points. The inflection point may indicate a point at which the sign of the radius of curvature changes from (+) to (-) or changes from (-) to (+). Alternatively, the inflection point may indicate a point at which the shape of the lens changes from convex to concave or from concave to convex. The seventh lens L7 may have, for example, a meniscus shape convex toward the object OBJ from the center of the lens surface (within a predetermined radius from the optical axis). For example, the exit surface 10 of the seventh lens L7 may have a concave shape toward the image plane IP near the optical axis OA, and a convex shape toward the periphery from the optical axis OA. For example, the incident surface 9 of the seventh lens L7 may have a convex shape toward the object side OBJ near the optical axis OA, and may have a concave shape toward the periphery from the optical axis OA.

The eighth lens L8 may have a negative refractive power and may be an aspherical lens having two or more inflection points. The eighth lens L8 may have, for example, a meniscus shape convex toward the object OBJ from the center (within a predetermined radius from the optical axis) of the lens surface. For example, the exit surface 12 of the eighth lens L8 may have a concave shape toward the image plane IP near the optical axis OA and may have a convex shape toward the periphery from the optical axis OA. For example, the incident surface 11 of the eighth lens L8 may have a convex shape toward the object side OBJ near the optical axis OA, and may have a concave shape toward the periphery from the optical axis OA.

At least one optical filter (OF) may be provided between the eighth lens L8 and the image surface IP. The optical filter OF may include, for example, at least one of a low pass filter, an infrared cut filter, and a cover glass. For example, when an infrared cut filter is provided as the optical filter OF, visible light is transmitted and infrared is emitted to the outside, so that infrared rays are not transmitted to the upper surface. However, it is also possible to configure the photographing lens without the optical filter OF.

The lens optical system may satisfy the following conditional expression (7).

Conditional expression (5): 0.55 ≤ TTL/IH ≤ 0.8

Here, TTL (unit: mm) represents a distance from the center of the incident surface 1 of the first lens L1 to the image surface IP.

The lens optical system satisfying condition (7) reduces the overall length of the lens optical system compared to the size of the image plane IP, thereby realizing an ultra-slim optical system.

Since the lens optical system can satisfy the following conditional expression (8), a high-resolution wide-angle lens can be implemented.

Conditional expression (8): 70 ≤ Fov ≤ 90

Here, FOV (unit: °) represents the angle of view of the lens optical system.

Meanwhile, in the lens optical system having the above configuration, at least one of the first to eighth lenses L1 to L8 may be made of a plastic material. The first lens L1, the third lens, and the fifth lens L5 to the eighth lenses L3 to L8 may all be made of a plastic material. If such a plastic lens is used, it may be lighter than the case of using a glass and advantageous for mass production. Further, as described above, the optical bonding material 20 of the second lens L2 fills the space between the first lens L1 and the third lens L3, and the optical bonding material of the fourth lens L4 As 40 fills the space between the third lens L3 and the fifth lens L5, the first to fifth lenses L1 to L5 may constitute a group of junction lenses, and thus The thickness of the first to fifth lenses L1 to L5 can be made very thin, and accordingly, the lens optical system can achieve ultra-small and ultra-slim while maintaining high performance.

In the present application, the material of the first lens L1, the third lens L3, and the fifth to eighth lenses L5 to L8 is not limited to plastic. If necessary, some of the first lens L1, the third lens L3, and the fifth to eighth lenses L5 to L8 may be made of glass. For example, the first lens L1, the third lens L3, and the fifth lens L5 are made of plastic, and at least one of the sixth to eighth lenses L6 to L8 is made of glass. You may. When a glass lens is used, higher reliability can be secured than when a plastic lens is used.

Meanwhile, in FIG. 1 , the stoppers (Stop, ST) are illustratively, but is not limited thereto. The stop ST may be disposed at another position in the lens optical system, or there may be no stop ST.

Next, the mechanical structure of the bonding of the bonding lens CL will be described.

The first lens L1 includes a first lens body 10 defined by an incident surface 1 and an exit surface (that is, the first interface 2), and a first lens body 10 extending outside the first lens body 10. 1 includes a lens end (11).

Similarly, the third lens L3 includes a third lens body 30 defined by an incident surface (ie, the second interface surface 3) and an exit surface (ie, the third interface surface 4), and the third lens body and a third lens end 31 extending from the periphery of 30 . The fifth lens L5 includes a fifth lens body 50 defined by an incident surface (that is, the fourth boundary surface 5) and an exit surface 6, and a fifth lens body 50 extending from the outside of the fifth lens body 50. 5 lens end 51 .

Concave grooves are provided on both sides of the third lens end 31 so that the first lens L1 and the fifth lens L5 can be fitted thereinto. Specifically, a part of the first lens end 11 of the first lens L1 is inserted into one side of the third lens end 31 and is stepped in a shape that can be in contact, and the fifth lens L5 is at the other side of the third lens end 31 . A portion of the fifth lens end 51 is inserted and stepped in a shape that can be abutted. In other words, the mechanical outer diameter of the third lens L3 is greater than the mechanical outer diameter of the first and fifth lenses L1 and L5, and the third lens end 31 has the first and fifth ends 11 and 51 ) is configured to be surrounded by the outside.

On the other hand, the exit surface (ie, the first interface surface 2) of the first lens (L1) and the incident surface (ie, the second interface surface (3)) of the third lens (L3) are spaced apart by a predetermined interval, The space between them is filled with an optical bonding material 20 . The optical bonding material 20 may also be positioned between the abutting surfaces of the first lens end 11 and the third lens end 31 . The optical bonding material 20 may be, for example, a UV curable material or a thermally curable material, and as the optical bonding material 20 filled in the space between the first lens L1 and the third lens L3 is cured, the second The first lens L1 and the third lens L3 are bonded together.

Similarly, the exit surface (ie, the third boundary surface 4) of the third lens L3 and the incidence surface (ie, the fourth boundary surface 5) of the fifth lens L5 are spaced apart by a predetermined interval, The space between them is filled with an optical bonding material 40 . The optical bonding material 40 may also be positioned between the contact surfaces of the third lens end 31 and the fifth lens end 51 . The optical bonding material 40 may be, for example, a UV curable material or a thermally curable material, and as the optical bonding material 40 filled in the space between the third lens L3 and the fifth lens L5 is cured, the first The third lens L3 and the fifth lens L5 are joined together.

The optical bonding materials 20 and 40, when cured, may have refractive power satisfying the above-described conditional expressions (3) and (4), and thus serve as the second and fourth lenses L2 and L4. will do

As described above, by manufacturing the first to fifth lenses L1 to L5 as an integral bonding lens CL, it is possible to facilitate alignment of the spacing and optical axes between the first to fifth lenses L1 to L5. In addition, by assembling the first to fifth lenses L1 to L5 with other lenses (that is, the sixth to eighth lenses L6 to L8) in the form of an integral junction lens CL, excellent performance is realized and It is possible to implement an optical system that can increase production productivity.

In FIG. 2 , the third lens end 31 of the third lens L3 has only a step defining a concave groove, but is not limited thereto. On one of the surfaces where the first lens end 11 and the third lens end 31 face each other, a protrusion or a chin to keep the distance between the first lens L1 and the third lens L3 more stable. , a step difference, etc. may be additionally provided. Similarly, on one of the surfaces where the third lens end 31 and the fifth lens end 51 face each other, there is a protrusion or , a chin, a step, etc. may be additionally provided.

In FIG. 2 , a case in which a concave groove is formed in the third lens end 31 of the third lens L3 is described as an example, but the present invention is not limited thereto.

3A to 3E are views illustrating other examples of an end of a lens. In the following description, except for the end shapes of the first, third, and fifth lens ends 11, 31, and 51, the mechanical bonding of the first to fifth lenses L1 to L5 described with reference to FIG. 2 is omitted. Since the structure is substantially the same, the overlapping description will be omitted.

Referring to FIG. 3A , a concave groove is provided in the first lens end 11 of the first lens L1 so that one side of the third lens end 31 of the third lens L3 can be inserted. Similarly, a concave groove is provided in the fifth lens end 51 of the fifth lens L5 so that the other side of the third lens end 31 of the third lens L3 can be inserted. Specifically, one side of the third lens end 31 is inserted into one surface of the first lens end 11 and is stepped in a shape that can be in contact with, and the third lens end is formed on one surface of the fifth lens end 51 . (51) The other side is inserted and stepped in a shape that can be abutted. In other words, the outer mechanical diameter of the third lens L3 is smaller than the mechanical outer diameter of the first and fifth lenses L1 and L5, and the outer edge of the third lens end 31 is formed at the first and fifth ends ( 11, 51). In addition, from the viewpoint of manufacturing the bonding lens CL, the third lens end 31 has a thickness (that is, the separation distance between the first lens L1 and the third lens L3) by appropriately selecting the thickness thereof. The thickness ThilL2 of the second lens L2 or the separation distance between the third lens L3 and the fifth lens L5 (ie, the thickness ThilL4 of the fourth lens L4) can be more stably secured. .

Referring to FIG. 3B , a concave groove is provided on one side of the third lens end 31 of the third lens L3, so that a part of the first lens end 11 of the first lens L1 can be fitted, A concave groove may be provided on one side of the fifth lens end 51 of the fifth lens L5 so that a part of the third lens end 31 of the third lens L3 may be fitted thereinto. At this time, the mechanical outer diameter of the third lens (L3) is larger than the mechanical outer diameter of the first lens (L1), the mechanical outer diameter of the fifth lens (L5) is larger than the mechanical outer diameter of the third lens (L3) can be configured. In addition, as illustrated in the drawings, the first lens L1 and the third lens L3 are on the third lens end 31 side of the surfaces where the first lens end 11 and the third lens end 31 face each other. ) is additionally provided to maintain the distance, similarly, the third lens L3 and the fifth lens L5 on one of the surfaces where the third lens end 31 and the fifth lens end 51 face each other. ) may be additionally provided with a protrusion, a chin, a step, etc. to keep the spacing more stable.

Referring to FIG. 3C , a concave groove is provided on one side of the first lens end 11 of the first lens L1 , and the first lens is provided on one side of the third lens end 31 of the third lens L3 . A first protrusion corresponding to the concave groove of the end 11 may be formed so that the first protrusion of the third lens end 31 can be fitted into the concave groove of the first lens end 11 . Similarly, a concave groove is provided on one side of the fifth lens end 51 of the fifth lens L5, and the fifth lens end 51 is provided on the other side of the third lens end 31 of the third lens L3. A second protrusion is formed corresponding to the concave groove of , so that the second protrusion of the third lens end 31 can be fitted into the concave groove of the fifth lens end 51 . In this case, the mechanical outer diameters of the first, third, and fifth lenses L1 , L3 , and L5 may be configured to be the same.

Referring to FIG. 3D , a concave groove is provided on one side of the third lens end 31 of the third lens L3 , and the third lens is provided on one side of the first lens end 11 of the first lens L1 . A first protrusion corresponding to the concave groove of the end 31 may be formed so that the first protrusion of the first lens end 11 can be fitted into the concave groove of the third lens end 31 . Similarly, a concave groove is provided on one side of the fifth lens end 51 of the fifth lens L5, and the fifth lens end 51 is provided on the other side of the third lens end 31 of the third lens L3. A second protrusion is formed corresponding to the concave groove of , so that the second protrusion of the third lens end 31 can be fitted into the concave groove of the fifth lens end 51 . In this case, the mechanical outer diameters of the first, third, and fifth lenses L1 , L3 , and L5 may be configured to be the same.

Referring to FIG. 3E , a concave groove is provided on one side of the third lens end 31 of the third lens L3 , and the third lens is provided on one side of the first lens end 11 of the first lens L1 . A first protrusion corresponding to the concave groove of the end 31 may be formed so that the first protrusion of the first lens end 11 can be fitted into the concave groove of the third lens end 31 . Similarly, a concave groove is provided on the other side of the third lens end 31 of the third lens L3, and the third lens end 31 is provided on the other side of the fifth lens end 51 of the fifth lens L5. A second protrusion is formed corresponding to the concave groove of , so that the fifth protrusion of the fifth lens end 51 can be fitted into the concave groove of the third lens end 31 . In this case, the mechanical outer diameters of the first, third, and fifth lenses L1 , L3 , and L5 may be configured to be the same.

The mechanical structure of the bonding of the first to fifth lenses (L1 to L5) is variously modified as disclosed in Korean Patent Application No. 10-2020-0039437 (filed date: March 31, 2020) previously filed by the present applicant This is possible.

Furthermore, in the present embodiment, although the structure in which the first, third, and fifth lens ends 11 , 31 , and 51 are fitted to each other is mainly described, the present embodiment is not limited thereto. Since the optical bonding material itself of the second lens L2 and the fourth lens L4 has adhesive properties, the first, third, and fifth lens ends 11, 31, and 51 all have a flat simple structure. Even so, the first lens L1 and the third lens L3 may be bonded, and the third lens L3 and the fifth lens L5 may be bonded. However, since the first lens L1 and the third lens L3 must maintain a predetermined distance and the third lens L3 and the fifth lens L5 must maintain a predetermined distance, the manufacturing of the junction lens CL In the curing step of the optical bonding material during the process, a device for supporting the first, third, and fifth lenses L1 , L3 , and L5 to maintain a predetermined distance may be additionally required.

In the present invention, a lens optical system can be implemented through numerical embodiments according to various designs as follows.

In each numerical embodiment, lens surface numbers (1, 2, 3, ..., n; n is a natural number) are sequentially arranged from the object OBJ side to the image surface IP side, and the drawing shows the signs of the lens surfaces. And, OBJ is the object, EFL is the focal length of each lens, F-no is the F number, FOV is the angle of view, R is the radius of curvature, Dn is the thickness of the lens or the air gap between the lens and the lens, Nd represents the refractive index, and Vd represents the Abbe's number. ST stands for aperture.

Meanwhile, the definition of the aspherical surface used in the lens optical system according to the embodiment of the present invention is as follows.

The aspherical shape can be expressed by the following formula with the direction of the optical axis as the x-axis and the direction perpendicular to the direction of the optical axis as the y-axis as the propagation direction of the light beam being positive. where x is the distance from the vertex of the lens in the direction of the optical axis, y is the distance in the direction perpendicular to the optical axis, K is the conic constant, and A, B, C, D, E and F are In the aspherical coefficient, c denotes the reciprocal (1/R) of the radius of curvature at the apex of the lens, respectively.

< Aspheric Equation >

<First Numerical Example>

1 shows a lens optical system according to a first numerical embodiment, and Table 1 below shows design data of the first numerical embodiment.

noodle Radius Thickness Nd Vd One 1.96174 0.47531 1.53349 55.85588 2 11.41168 0.05000 1.56112 46.01898 3 4.72274 0.22000 1.66709 20.35619 4 2.94904 0.05000 1.56112 46.01898 5 2.86790 0.37143 1.53349 55.85588 6 6.05413 0.57445 7 -5.80693 0.58268 1.66709 20.35619 8 -8.28243 0.70662 9 18.58276 0.68321 1.61927 25.95994 10 16.75499 0.40458 11 2.13378 0.83617 1.53349 55.85588 12 1.61735 0.45000 13 Infinity 0.11000 1.51827 64.19733 14 Infinity 0.99554 Image Infinity -0.01000

Tables 2 and 3 below show the aspheric coefficients of the first numerical example.

noodle K 4th 6th 8th 10th One -0.07972 -0.00015 0.00429 -0.01400 0.02737 2 0.00000 -0.06540 0.14632 -0.04210 0.00000 3 10.02857 0.07303 -0.09024 0.08243 -0.32166 4 4.47931 0.04453 -0.06475 0.00000 0.00000 5 -13.41692 0.11145 0.06114 -0.18674 0.08642 6 -1.70660 -0.00472 -0.02092 0.12335 -0.41705 7 24.11368 -0.02838 -0.02694 0.03964 -0.04896 8 -69.21226 -0.03994 -0.01979 0.04087 -0.05449 9 24.93742 0.01611 -0.03592 0.03406 -0.02895 10 -3.85552 -0.04238 0.04013 -0.02287 0.00728 11 -4.56344 -0.11855 0.04097 -0.00899 0.00142 12 -1.00000 -0.13985 0.04643 -0.01213 0.00221 13 14 Image

noodle 12th 14th 16th 18th 20th One -0.03107 0.01939 -0.00656 0.00113 -0.00008 2 0.00000 0.00000 0.00000 0.00000 0.00000 3 0.85761 -1.37089 1.29738 -0.66009 0.13774 4 0.00000 0.00000 0.00000 0.00000 0.00000 5 -0.01180 0.00000 0.00000 0.00000 0.00000 6 0.76925 -0.81170 0.47846 -0.14700 0.01837 7 0.07092 -0.10960 0.10485 -0.04864 0.00815 8 0.05219 -0.03240 0.01251 -0.00261 0.00022 9 0.01524 -0.00502 0.00100 -0.00011 0.00000 10 -0.00151 0.00021 -0.00002 0.00000 0.00000 11 -0.00016 0.00001 0.00000 0.00000 0.00000 12 -0.00027 0.00002 0.00000 0.00000 0.00000 13 14 Image

4 shows longitudinal spherical aberration, astigmatic field curves, and distortion of the lens optical system according to the first numerical embodiment. As field curvature, it shows meridional field curvature (T: tangential field curvature) and sagittal field curvature (S: sagittal field curvature).

<Second Numerical Example>

5 shows a lens optical system according to a second numerical embodiment, and Table 4 below shows design data of the second numerical embodiment.

noodle Radius Thickness Nd Vd One 1.96064 0.48279 1.53605 55.65625 2 13.42281 0.03095 1.52147 64.99902 3 5.09883 0.27267 1.66692 20.35322 4 3.04855 0.04000 1.52147 64.99902 5 2.70724 0.47359 1.66692 20.35322 6 6.03183 0.56665 7 -5.83731 0.56011 1.66692 20.35322 8 -7.98034 0.73130 9 20.51644 0.69448 1.61927 25.95994 10 15.32438 0.32288 11 2.08179 0.79842 1.53605 55.65625 12 1.60285 0.45000 13 Infinity 0.11000 1.51827 64.19733 14 Infinity 0.76358 Image Infinity 0.00258

Tables 5 and 6 below show the aspheric coefficients of the second numerical example.

noodle K 4th 6th 8th 10th One -0.05644 0.00023 0.00490 -0.01351 0.02772 2 0.00000 0.08948 -0.01136 -0.00334 0.00000 3 7.57542 0.01520 0.11616 -0.90572 3.13918 4 4.54126 0.02390 -0.05162 0.00000 0.00000 5 -13.58218 0.11827 -0.11707 0.03598 -0.00422 6 -0.42373 -0.00224 -0.02925 0.14018 -0.38258 7 23.93373 -0.03191 -0.03235 0.07260 -0.13180 8 -51.17913 -0.03936 -0.02956 0.06011 -0.07563 9 9.02639 0.01998 -0.04109 0.03666 -0.03060 10 19.09866 -0.04233 0.03955 -0.02417 0.00844 11 -4.80634 -0.11884 0.04141 -0.00924 0.00150 12 -1.00000 -0.13989 0.04646 -0.01214 0.00221 13 14 Image

noodle 12th 14th 16th 18th 20th One -0.03092 0.01935 -0.00656 0.00113 -0.00008 2 0.00000 0.00000 0.00000 0.00000 0.00000 3 -6.48395 8.17566 -6.15883 2.54410 -0.44316 4 0.00000 0.00000 0.00000 0.00000 0.00000 5 0.00013 0.00000 0.00000 0.00000 0.00000 6 0.61094 -0.58635 0.32305 -0.09402 0.01120 7 0.18912 -0.21014 0.15628 -0.06351 0.01000 8 0.06593 -0.03763 0.01359 -0.00271 0.00022 9 0.01660 -0.00569 0.00117 -0.00013 0.00001 10 -0.00191 0.00029 -0.00003 0.00000 0.00000 11 -0.00017 0.00001 0.00000 0.00000 0.00000 12 -0.00027 0.00002 0.00000 0.00000 0.00000 13 14 Image

6 illustrates longitudinal spherical aberration, astigmatic field curves, and distortion of the lens optical system according to the second numerical embodiment.

<Third Numerical Example>

7 shows a lens optical system according to a third numerical embodiment, and Table 7 below shows design data of the third numerical embodiment.

noodle Radius Thickness Nd Vd One 1.87873 0.36348 1.53605 55.65625 2 6.08624 0.02500 1.58171 61.99905 3 4.28008 0.23132 1.66692 20.35322 4 2.74063 0.02494 1.58171 61.99905 5 6.17645 0.30527 1.66692 20.35322 6 5.36972 0.60596 7 -5.80265 0.64254 1.66692 20.35322 8 -7.71569 0.73318 9 17.07813 0.69396 1.61927 25.95994 10 15.46005 0.41468 11 1.99964 0.76116 1.53605 55.65625 12 1.53101 0.45000 13 Infinity 0.11000 1.51827 64.19733 14 Infinity 0.83667 Image Infinity 0.00183

Tables 8 and 9 below show the aspheric coefficients of the third numerical example.

noodle K 4th 6th 8th 10th One 0.00171 0.00186 0.00608 -0.01290 0.02804 2 0.00000 0.07230 -0.02127 0.00077 0.00000 3 7.22331 0.03101 0.03575 -0.56296 2.03399 4 4.89855 0.02619 -0.07370 0.00000 0.00000 5 8.47539 0.18967 -0.04762 -0.02752 0.01254 6 0.62876 -0.01035 0.01382 -0.02285 0.02414 7 23.02677 -0.03762 0.02508 -0.16135 0.48215 8 -50.56390 -0.04637 -0.01052 0.02616 -0.03934 9 -186.53162 0.01491 -0.03501 0.03422 -0.03474 10 31.48392 -0.03728 0.04403 -0.03139 0.01219 11 -4.87302 -0.10060 0.03422 -0.00791 0.00132 12 -1.00000 -0.14092 0.04645 -0.01213 0.00221 13 14 Image

noodle 12th 14th 16th 18th 20th One -0.03093 0.01899 -0.00656 0.00113 -0.00008 2 0.00000 0.00000 0.00000 0.00000 0.00000 3 -4.33609 5.58171 -4.22735 1.74176 -0.30222 4 0.00000 0.00000 0.00000 0.00000 0.00000 5 -0.00131 0.00000 0.00000 0.00000 0.00000 6 0.00909 -0.04011 0.02994 -0.00925 0.00106 7 -0.82401 0.82882 -0.47695 0.14457 -0.01816 8 0.04277 -0.02930 0.01222 -0.00270 0.00024 9 0.02119 -0.00784 0.00170 -0.00019 0.00001 10 -0.00300 0.00048 -0.00005 0.00000 0.00000 11 -0.00015 0.00001 0.00000 0.00000 0.00000 12 -0.00027 0.00002 0.00000 0.00000 0.00000 13 14 Image

8 shows longitudinal spherical aberration, astigmatic field curves, and distortion of the lens optical system according to the third numerical embodiment.

Meanwhile, the F-number (Fno), focal length (f), and angle of view (FOV) of the lens optical system according to the first to third numerical embodiments of the present invention are summarized in Table 10 below.

Terms Example 1 Example 2 Example 3 Fov 76.52 75.85 75.45 f 5.77 5.47 5.37 Fno 2.50 2.50 2.62

The following shows that the lens optical systems according to the first to third numerical embodiments satisfy Conditional Expressions 1 to 8. In Table 11, the unit of FOV (angle of view) is °.

Terms Justice Example 1 Example 2 Example 3 conditional expression 1 0.01 ≤ ThiL2 ≤ 0.1 0.02 0.08 0.05 conditional expression 2 1.4 ≤ Ind2 ≤ 1.8 1.56 1.60 1.67 conditional expression 3 0.15 ≤ OAL_L1L2L3/OAL ≤ 0.25 0.20 0.23 0.22 condition 4 0.1 ≤ OAL_L1L2L3/IH ≤ 0.2 0.12 0.14 0.15 conditional expression 5 0.55 ≤ TTL/IH ≤ 0.8 0.64 0.63 0.69 conditional expression 6 70 ≤ Fov ≤ 90 79.49 78.96 70.96 conditional expression 7 0.55 ≤ TTL/IH ≤ 0.8 0.68 0.66 0.65 conditional expression 8 70 ≤ Fov ≤ 90 76.52 75.85 75.45

Table 12 summarizes the values of variables required to obtain Table 11. In Table 12, Semi IH is half of the effective image height, BFL is the distance from the center of the exit surface of the seventh lens L7 to the image plane IP (sensor surface of the image sensor), Ind1, Ind2, Ind3, Ind4, and Ind5 are The refractive index of the first lens L1, the refractive index of the second lens L2, the refractive index of the third lens L3, the refractive index of the fourth lens L4 and the refractive index of the fifth lens L5, Abv1, Abv2, Abv3, Abv4 and Abv5 are the Abv number of the first lens L1, the Abbe number of the second lens L2, the Abbe number of the third lens L3, the Abbe number of the fourth lens L4, and the fifth lens, respectively. The Abbe number of (L5) is shown. The units of TTL, IH, Semi IH, OAL, OAL_L1L2L3, B.F.L, and ThiL2 values are in millimeters.

Terms Example 1 Example 2 Example 3 IH 9.50 9.50 9.50 Semi IH 4.75 4.75 4.75 TTL 6.50 6.30 6.20 OAL 4.95 4.97 4.80 OAL_L1toL5 1.17 1.30 0.95 B.F.L. 1.55 1.33 1.40 ThiL2 0.050 0.031 0.025 ThiL4 0.050 0.040 0.025 Ind1 1.533 1.536 1.536 Ind2 1.561 1.521 1.582 Ind3 1.667 1.667 1.667 Ind4 1.561 1.521 1.582 Ind5 1.533 1.667 1.667 Abv1 55.86 55.66 55.66 Abv2 46.02 65.00 62.00 Abv3 20.36 20.35 20.35 Abv4 46.02 65.00 62.00 Abv5 55.86 20.35 20.35

Fig. 9 shows an example of an imaging device (mobile phone) 100 having a lens optical system according to an exemplary embodiment. The imaging device 100 includes a lens optical system 110 and an image sensor 120 that receives an image formed by the lens optical system 110 and converts the light into an electrical image signal. The lens optical system described with reference to FIGS. 1 to 8 may be employed as the lens optical system 110 . By applying the lens optical system according to the exemplary embodiment to an imaging device such as a small digital camera, a camera for a mobile phone, or a camera for a vehicle, an imaging device capable of taking pictures can be implemented.

The imaging device shown in FIG. 9 is only a general example and is applicable to more various optical devices. For example, the lens optical system according to the present embodiment may be applied to a lens system of a vehicle camera. In addition, the lens optical system may be applied to a virtual reality device, an augmented reality device, and the like. For example, in the virtual reality device, the lens optical systems according to the above-described embodiment may be provided to face in opposite directions. For example, the lens optical system according to an embodiment of the present invention may be applied to various vehicle devices such as a black box, an around view monitoring (AVM) system, or a rear view camera. In addition, the lens optical system may be applied to various action cams such as drones or camcorders for leisure sports. In addition, the lens optical system may be applied to various surveillance cameras.

In addition, although many matters are specifically described in the above description, they should be construed as examples of preferred embodiments rather than limiting the scope of the invention. For example, those of ordinary skill in the art to which the present invention pertains, even if the shape of the lenses in the lens optical system according to the embodiment of the present invention is slightly deformed, at least one of the above conditional expressions (1) to (6) If satisfied, it can be seen that the effect as described above can be obtained. In addition, even if at least some of the conditional expressions (1) to (6) are not satisfied, it can be seen that when the power arrangement, shape condition, and other conditions of the lenses are satisfied, the effect as described above can be obtained. In addition, it will be appreciated that various modifications are possible. Therefore, the scope of the present invention should not be determined by the described embodiments, but should be determined by the technical idea described in the claims.

CL: junction lens L1: first lens
L2: second lens L3: third lens
L4: fourth lens L5: fifth lens
L6 : 6th lens L7 : 7th lens
L8: 8th lens OA: Optical axis
OF : optical filter OBJ : object
ST: Aperture IP: Top
10, 30, 50: lens body 11, 31, 51: lens end
20, 40: optical bonding material

Claims (21)

It includes first to eighth lenses arranged in order from the object side to the image plane side,
The first lens, the third lens, and the fifth lens are formed of plastic,
The second lens and the fourth lens are formed of an optical bonding material,
The optical bonding material of the second lens and the optical bonding material of the fourth lens are respectively filled in the space between the first lens and the third lens and the space between the third lens and the fifth lens, and the first lens , forming a group of bonding lenses in which the third lens and the fifth lens are bonded by the bonding force of the second lens and the fourth lens,
The refractive index of the second lens and the refractive index of the fourth lens are different from the refractive index of the first lens, the refractive index of the third lens, and the refractive index of the fifth lens,
an incident surface of the first lens, a first interface between the first lens and the second lens, a second interface between the second lens and the third lens, and a second interface between the third lens and the fourth lens At least one of the 3 interface, the fourth interface between the fourth lens and the fifth lens, and the exit surface of the fifth lens is an aspherical surface,
The first interface and the second interface have different shapes,
The third interface and the fourth interface have different shapes from each other. According to claim 1,
A lens optical system that satisfies at least one of the following conditional expressions.
Conditional Expression (1): 0.01 ≤ ThiL2 ≤ 0.1
Conditional Expression (2): 0.01 ≤ ThiL4 ≤ 0.1
Here, ThilL2 represents the thickness of the second lens, and ThilL4 represents the thickness of the fourth lens. According to claim 1,
A lens optical system that satisfies at least one of the following conditional expressions.
Conditional Expression (3): 1.4 ≤ Ind2 ≤ 1.8
Conditional Expression (4): 1.4 ≤ Ind4 ≤ 1.8
Here, Ind2 represents the refractive index of the second lens, and Ind4 represents the refractive index of the fourth lens. According to claim 1,
A lens optical system that satisfies at least one of the following conditional expressions.
Conditional Expression (5): 0.15 ≤ OAL_L1toL5/OAL ≤ 0.25
Conditional expression (6): 0.1 ≤ OAL_L1toL5/IH ≤ 0.2
Here, OAL_L1toL5 (unit: mm) represents the distance between the center of the incident surface of the first lens and the center of the exit surface of the fifth lens, and OAL (unit: mm) is the center of the incident surface of the first lens and the eighth lens represents the distance between the centers of the exit surfaces of , and IH (unit: mm) represents the height of the effective diameter. According to claim 1,
A lens optical system that satisfies at least one of the following conditional expressions.
Conditional expression (7): 0.55 ≤ TTL/IH ≤ 0.8
Conditional expression (8): 70 ≤ Fov ≤ 90
Here, TTL (unit: mm) represents the distance from the center of the incident surface of the first lens to the image plane, and FOV (unit: °) represents the angle of view of the lens optical system. According to claim 1,
The junction lens has a positive (+) refractive power,
The sixth lens has a negative (-) refractive power,
The seventh lens has a negative (-) refractive power,
The eighth lens is a lens optical system having negative (-) refractive power. According to claim 1,
The junction lens is an aspherical lens with an incident surface convex toward the object side of the lens optical system. According to claim 1,
The sixth lens is a lens optical system that is an aspherical lens. According to claim 1,
At least one of the seventh and eighth lenses is an aspherical lens having two or more inflection points. Arranged in order from the object side to the upper surface side,
a junction lens having positive (+) refractive power and comprising first to fifth lenses;
a sixth lens having negative (-) refractive power;
a seventh lens having a negative refractive power; and
Including; an eighth lens having a negative refractive power;
The second lens and the fourth lens are formed of an optical bonding material,
The optical bonding material of the second lens and the optical bonding material of the fourth lens are respectively filled in the space between the first lens and the third lens and the space between the third lens and the fifth lens. The 3rd lens and the 5th lens form a group of bonding lenses which are bonded by the bonding force of the second lens and the fourth lens,
The refractive index of the second lens and the refractive index of the fourth lens are different from the refractive index of the first lens, the refractive index of the third lens, and the refractive index of the fifth lens,
The junction lens is an aspherical lens in which the incident surface is convex toward the object side of the lens optical system. 20. The method of claim 19,
A lens optical system that satisfies at least one of the following conditional expressions.
Conditional Expression (1): 0.01 ≤ ThiL2 ≤ 0.1
Conditional Expression (2): 0.01 ≤ ThiL4 ≤ 0.1
Here, ThilL2 represents the thickness of the second lens, and ThilL4 represents the thickness of the fourth lens. 11. The method of claim 10,
A lens optical system that satisfies at least one of the following conditional expressions.
Conditional Expression (3): 1.4 ≤ Ind2 ≤ 1.8
Conditional Expression (4): 1.4 ≤ Ind4 ≤ 1.8
Here, Ind2 represents the refractive index of the second lens, and Ind4 represents the refractive index of the fourth lens. 11. The method of claim 10,
A lens optical system that satisfies at least one of the following conditional expressions.
Conditional expression (5): 0.15 ≤ OAL_L1toL5/OAL ≤ 0.25
Conditional expression (6): 0.1 ≤ OAL_L1toL5/IH ≤ 0.2
Here, OAL_L1toL5 (unit: mm) represents the distance between the center of the incident surface of the first lens and the center of the exit surface of the fifth lens, and OAL (unit: mm) is the center of the incident surface of the first lens and the eighth lens represents the distance between the centers of the exit planes, and IH (unit: mm) represents the height of the effective diameter. 11. The method of claim 10,
A lens optical system that satisfies at least one of the following conditional expressions.
Conditional expression (7): 0.55 ≤ TTL/IH ≤ 0.8
Conditional expression (8): 70 ≤ Fov ≤ 90
Here, TTL (unit: mm) represents the distance from the center of the incident surface of the first lens to the image plane, and FOV (unit: °) represents the angle of view of the lens optical system. 11. The method of claim 10,
The sixth lens is an aspherical lens optical system. 11. The method of claim 10,
At least one of the seventh lens and the eighth lens is an aspherical lens having two or more inflection points. 11. The method of claim 10,
The first lens, the third lens, and the fifth lens are made of plastic. 11. The method of claim 10,
A first interface between the first lens and the second lens and a second interface between the second lens and the third lens have different shapes,
A third interface between the third lens and the fourth lens and a fourth interface between the fourth lens and the fifth lens have different shapes from each other. a first lens, a second lens, a third lens, a fourth lens and a fifth lens,
The first lens, the third lens, and the fifth lens are formed of plastic,
The second lens and the fourth lens are formed of an optical bonding material,
The optical bonding material of the second lens and the optical bonding material of the fourth lens are respectively filled in the space between the first lens and the third lens and the space between the third lens and the fifth lens, and the first lens , forming a group of bonding lenses in which the third lens and the fifth lens are bonded by the bonding force of the second lens and the fourth lens,
The refractive index of the second lens and the refractive index of the fourth lens are different from the refractive index of the first lens, the refractive index of the third lens, and the refractive index of the fifth lens,
an incident surface of the first lens, a first interface between the first lens and the second lens, a second interface between the second lens and the third lens, and a second interface between the third lens and the fourth lens At least one of the 3 interface, the fourth interface between the fourth lens and the fifth lens, and the exit surface of the fifth lens is an aspherical surface,
The first interface and the second interface have different shapes,
The third interface and the fourth interface have different shapes,
A bonding lens that satisfies the following conditions.
Conditional Expression (1): 0.01 ≤ ThiL2 ≤ 0.1 20. The method of claim 19,
A lens optical system that satisfies at least one of the following conditional expressions.
Conditional Expression (1): 0.01 ≤ ThiL2 ≤ 0.1
Conditional Expression (2): 0.01 ≤ ThiL4 ≤ 0.1
Here, ThilL2 represents the thickness of the second lens, and ThilL4 represents the thickness of the fourth lens. The lens optical system according to any one of claims 1 to 18,
and a solid-state imaging device for imaging an image formed by the lens optical system.

Images