Optical system and camera device including the same

Abstract

An optical system according to an embodiment of the present invention includes a first lens having a positive refractive power, a second lens having a negative refractive power, a third lens having a positive refractive power, a fourth lens having a negative refractive power, a fifth lens having a negative refractive power, and a sixth lens disposed in order from an object side to an image side, the fifth lens has a positive refractive power, and the sixth lens has a negative refractive power. An object-side surface of the sixth lens is recessed toward the object side; an image-side surface of the fifth lens protrudes toward the image side; an object-side surface of the fifth lens and an image-side surface of the sixth lens include a critical point with an inclination angle of 0, and the object-side surface of the sixth lens has a maximum inclination angle in a range of 0.8 to 1.2 times a vertical distance from the optical axis to the critical point of the image-side surface of the sixth lens.

Description

Technical Field

[0001] Embodiments of the present invention relate to an optical system and a camera device including the optical system. Background Art

[0002] As the performance of camera devices built into mobile terminals increases, the demand for higher resolution of camera devices in mobile terminals is also increasing. In order to improve the performance of camera devices, high performance of optical systems and image sensors is required. However, due to the small space in mobile terminals, high performance of optical systems and image sensors is not easy.

[0003] Specifically, the demand for miniaturization of camera devices is further increasing. As camera devices become smaller, the amount of light reaching an image sensor through an optical system may decrease. Therefore, the F number that determines the brightness of an image will increase, and the amount of light reaching a peripheral area of ​​the image sensor may decrease compared to the amount of light reaching a central area of ​​the image sensor. Summary of the invention

[0004] Technical issues

[0005] The technical problem to be solved by the present invention is to obtain a camera module with a small F number, a large field of view and a high relative illumination while being realized in a small size.

[0006] The problems to be solved in the embodiments are not limited thereto, and it can be said that purposes or effects that can be understood from the specific contents of the solutions or inventions for achieving the problems described below are also included.

[0007] Technical Solutions

[0008] An 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 and a sixth lens arranged in sequence from the object side to the image side, wherein the first lens has a positive refractive power, the second lens has a negative refractive power, the third lens has a positive refractive power, the fourth lens has a negative refractive power, the fifth lens has a positive refractive power, and the sixth lens has a negative refractive power, the object side surface of the sixth lens is concave toward the object side, and the image side surface of the fifth lens is convex toward the image side, the object side surface of the fifth lens and the image side surface of the sixth lens include a critical point with an inclination angle of 0, and the object side surface of the sixth lens has a maximum inclination angle in the range of 0.8 times to 1.2 times the vertical distance from the optical axis to the critical point of the image side surface of the sixth lens.

[0009] The object-side surface of the sixth lens may have a maximum inclination angle within a range of 0.8 times to 1 times a perpendicular distance from the optical axis to a critical point of the image-side surface of the sixth lens.

[0010] The image-side surface of the fifth lens may have a maximum inclination angle within a range of 0.8 times to 1.2 times a perpendicular distance from the optical axis to a critical point of the object-side surface of the fifth lens.

[0011] The maximum inclination angle of the image side surface of the fifth lens may be 20 to 30 degrees within a range of 0.8 to 1.2 times the vertical distance from the optical axis to the critical point of the surface on the object side of the fifth lens, and the maximum inclination angle of the object side surface of the sixth lens may be 35 to 45 degrees within a range of 0.8 to 1.2 times the vertical distance from the optical axis to the critical point of the surface on the image side of the sixth lens.

[0012] An absolute value of a radius of curvature of an object-side surface of the sixth lens may be 1.2 to 1.5 times an absolute value of a radius of curvature of an image-side surface of the fifth lens.

[0013] The image-side surface of the fourth lens may include a critical point, and a vertical distance from the optical axis to the critical point of the image-side surface of the fourth lens may be 0.9 to 1.1 times a vertical distance from the optical axis to the critical point of the object-side surface of the fifth lens.

[0014] A vertical distance from the optical axis to a critical point of the image-side surface of the sixth lens may be 1.2 to 1.6 times a vertical distance from the optical axis to a critical point of the image-side surface of the fourth lens or a vertical distance from the optical axis to a critical point of the object-side surface of the fifth lens.

[0015] A center thickness of the fifth lens may be greater than a thickness of the fifth lens at a critical point of an object-side surface of the fifth lens.

[0016] A center thickness of the sixth lens may be smaller than a thickness of the sixth lens at a critical point of an image-side surface of the sixth lens.

[0017] An aperture may be provided at an edge of the object-side surface of the first lens.

[0018] Each of the image-side surface of the fifth lens and the object-side surface of the sixth lens may not include a critical point.

[0019] The F number may be 2.1 or less, the field of view (FOV) may be 90 degrees or more, and the relative illumination (RI) may be 19% or more.

[0020] According to one embodiment of the present invention, a camera device includes: an image sensor; a filter arranged on the image sensor; and an optical system arranged on the filter, wherein the optical system includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens arranged in sequence from the object side to the image side, the first lens has a positive refractive power, the second lens has a negative refractive power, the third lens has a positive refractive power, the fourth lens has a negative refractive power, the fifth lens has a positive refractive power, and the sixth lens has a negative refractive power, the object side surface of the sixth lens is concave toward the object side, and the image side surface of the fifth lens is convex toward the image side, the object side surface of the fifth lens and the image side surface of the sixth lens include a critical point with an inclination angle of 0, and the object side surface of the sixth lens has a maximum inclination angle in the range of 0.8 times to 1.2 times the vertical distance from the optical axis to the critical point of the image side surface of the sixth lens.

[0021] Beneficial Effects

[0022] According to an embodiment of the present invention, a camera device having a small F number, a large field of view (FOV), and a high relative illumination (RI) ratio can be obtained while being implemented in a small size.

[0023] According to an embodiment of the present invention, a camera device having an F number of 2.1 or less, a FOV of 90 degrees or more, and an RI of 19% or more in the full field of view (1 field) can be obtained while being implemented in a small size.

[0024] According to an embodiment of the present invention, a camera device can be obtained that minimizes the size of the head exposed to the outside while providing a bright image with a high RI. That is, in order to minimize the size of the head exposed to the outside, a camera device can be obtained that provides a bright image with a high RI around the sensor while designing the diameter of the lens disposed on the side closest to the object, that is, the first lens, to be small. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 An optical system according to an embodiment of the present invention is shown.

[0026] Figure 2 The relationship between the first lens and the aperture in the optical system according to the embodiment of the present invention is shown.

[0027] Figure 3 and Figure 4 It is a view used to describe relative illumination.

[0028] Figure 5 1 is design data showing the distance between lens surfaces according to the distance from the optical axis in the Y direction in the optical system according to the embodiment of the present invention.

[0029] Figure 6 1 is design data showing a sag value of a lens surface according to a distance from the optical axis in the Y direction in the optical system according to an embodiment of the present invention.

[0030] Figure 7 1 is design data showing the inclination angle of the lens surface according to the distance from the optical axis in the Y direction in the optical system according to the embodiment of the present invention.

[0031] Figure 8 The modulation transfer function (MTF) of an optical system using one embodiment of the present invention is shown.

[0032] Fig. 9 A distortion grid using an optical system according to one embodiment of the present invention is shown.

[0033] Fig.10 An optical system according to another embodiment of the present invention is shown.

[0034] Fig.11 1 is design data showing the distance between lens surfaces according to the distance from the optical axis in the Y direction in an optical system according to another embodiment of the present invention.

[0035] Fig.12 1 is design data showing a concavity value of a lens surface according to a distance from the optical axis in the Y direction in an optical system according to another embodiment of the present invention.

[0036] Fig.13 1 is design data showing the inclination angle of the lens surface according to the distance from the optical axis in the Y direction in the optical system according to another embodiment of the present invention.

[0037] Fig.14 A modulation transfer function (MTF) using an optical system according to another embodiment of the present invention is shown.

[0038] Fig.15 A distortion grid using an optical system according to another embodiment of the present invention is shown.

[0039] Fig.16 is a view showing a portion of a mobile terminal to which a camera device according to an embodiment of the present invention is applied. DETAILED DESCRIPTION

[0040] Hereinafter, exemplary embodiments according to the present invention will be described in detail with reference to the accompanying drawings.

[0041] However, the technical spirit of the present invention is not limited to some embodiments to be described, but can be implemented in various different forms, and one or more of the components between the embodiments can be selectively combined and substituted within the technical spirit of the present invention.

[0042] In addition, unless explicitly and specifically defined and described, the terms (including technical terms and scientific terms) used in the embodiments of the present invention may be interpreted as the meanings that may be generally understood by those skilled in the art, and the meanings of commonly used terms such as those defined in dictionaries may be understood considering the contextual meanings in the relevant technology.

[0043] Furthermore, the terms used in the embodiments of the present invention are provided not to limit the present invention but to describe the embodiments.

[0044] In this specification, unless otherwise specified in the phrase, the singular form may also include the plural form, and when disclosed as at least one (or one or more) of "A, B, and C", it may include one or more of all possible combinations of A, B, and C.

[0045] Furthermore, terms such as first, second, A, B, (a), (b), etc. may be used to describe components of embodiments of the present invention.

[0046] These terms are provided only to distinguish one component from another, and the nature, sequence, order, etc. of the elements are not limited by these terms.

[0047] Furthermore, when a particular component is disclosed as being “connected” to another component, “coupled” to another component, or “linked” to another component, this may include not only a case where the component is directly connected, coupled, or linked to another component, but also a case where the component is connected, coupled, or linked to another component via another component between the element and the other components.

[0048] In addition, when one component is disclosed as being formed "above or below" another component, the term "above or below" includes both a case where the two components are in direct contact with each other and a case where at least another component is (indirectly) disposed between the two components. In addition, when expressing the term "above or below", not only a meaning based on an upward direction of one component but also a meaning based on a downward direction of one component can be included.

[0049] Figure 1 An optical system according to an embodiment of the present invention is shown.

[0050] Reference Figure 1, an optical system 100 according to an 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 , and a sixth lens 160 which are sequentially arranged from an object side to an image side.

[0051] Although not shown, a right angle prism may be further disposed in front of the first lens 110 .

[0052] At least one of the first lens 110, the second lens 120, the third lens 130, the fourth lens 140, the fifth lens 150, and the sixth lens 160 may include an effective area and an ineffective area. The effective area may be an area through which light incident on the lens passes, i.e., an area through which the incident light is refracted to achieve optical characteristics. In this specification, the effective diameter may refer to the diameter of the effective area on each surface of each lens through which effective light is incident. In this specification, the value of the effective diameter may have a certain error range. For example, a range of ±0.4 mm may be considered as an effective area for the value of the effective diameter provided in this specification. The range of ±0.4 mm may be interpreted as an effective diameter for the value of the effective diameter presented in this specification. The ineffective area is set at the periphery of the effective area and may be an area where light is not incident, i.e., an area that is not related to optical characteristics. The ineffective area may be an area fixed to a lens barrel or the like that houses the lens.

[0053] According to an embodiment of the present invention, the filter 170 and the image sensor 180 may be sequentially arranged behind the sixth lens 160. In this case, the filter 170 may be an infrared (IR) filter. Therefore, the filter 170 may block near infrared rays in the light incident on the camera module, for example, light having a wavelength of 700nm to 1100nm. Alternatively, the filter 170 may be a filter that transmits IR, rather than a filter that blocks IR. In addition, the image sensor 180 may be connected to a printed circuit board.

[0054] Reference Figure 1 , the optical system 100 according to an 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, and a sixth lens 160 arranged in sequence from the object side to the image side. The first lens 110, the second lens 120, the third lens 130, the fourth lens 140, the fifth lens 150, and the sixth lens 160 may be arranged in sequence along the optical axis. The first lens 110, the second lens 120, the third lens 130, the fourth lens 140, the fifth lens 150, and the sixth lens 160 may be aspherical lenses. The first lens 110, the second lens 120, the third lens 130, the fourth lens 140, the fifth lens 150, and the sixth lens 160 may each be made of plastic or glass.

[0055] The first lens 110 has a positive refractive power and includes an object side surface 112 and an image side surface 114, and the object side surface 112 of the first lens 110 may be convex with respect to the object side, and the image side surface 114 may be concave with respect to the image side. Here, the case where the lens surface is convex may refer to that the surface of the lens in the region corresponding to the optical axis has a convex shape, and the case where the lens surface is concave may refer to that the surface of the lens in the region corresponding to the optical axis has a concave shape. Here, the region corresponding to the optical axis may refer to the optical axis region or the paraxial region. In addition, the case where the surface of the lens is convex with respect to the object side may refer to that the surface of the lens is concave with respect to the image side, and the case where the surface of the lens is convex with respect to the image side may refer to that the surface of the lens is concave with respect to the object side.

[0056] The second lens 120 has negative refractive power and includes an object-side surface 122 and an image-side surface 124 , and the object-side surface 122 of the second lens 120 may be convex to the object side, and the image-side surface 124 may be concave to the image side.

[0057] The third lens 130 has positive refractive power and includes an object-side surface 132 and an image-side surface 134 , and the object-side surface 132 of the third lens 130 may be convex to the object side and the image-side surface 134 may be concave to the image side.

[0058] The fourth lens 140 has negative refractive power and includes an object-side surface 142 and an image-side surface 144 , and the object-side surface 142 of the fourth lens 140 may be convex to the object side and the image-side surface 144 may be concave to the image side.

[0059] The fifth lens 150 may have positive refractive power and include an object-side surface 152 and an image-side surface 154 , and the object-side surface 152 of the fifth lens 150 is convex to the object side, and the image-side surface 154 is convex to the image side.

[0060] The sixth lens 160 has negative refractive power and includes an object-side surface 162 and an image-side surface 164 , and the object-side surface 162 of the sixth lens 160 may be concave with respect to the object side, and the image-side surface 164 may be concave with respect to the image side.

[0061] In an embodiment of the present invention, when the first lens 110 has positive refractive power, the second lens 120 has negative refractive power, the third lens 130 has positive refractive power, the fourth lens 140 has negative refractive power, the fifth lens 150 has positive refractive power, and the sixth lens 160 has negative refractive power, chromatic aberration can be corrected.

[0062] Figure 2The relationship between the first lens and the aperture in the optical system according to the embodiment of the present invention is shown.

[0063] Reference Figure 2 , an aperture ST is provided on the first lens 110. The aperture ST may adjust the amount of light incident on the optical system 100. For example, the aperture ST may be provided at the edge of the object-side surface 112 of the first lens 110. For example, the aperture ST may be provided to contact the edge of the object-side surface 112 of the first lens 110. Therefore, the effective diameter (ED) of the first lens 110 L1S1 ) may be 90% to 110% of an entrance pupil diameter (EPD) of the optical system 100, preferably 95% to 110%, more preferably 97% to 110%, and more preferably 100% to 110%.

[0064] Therefore, since the area where the object-side surface 112 of the first lens 110 is exposed to the outside can be minimized, the head size of the optical system 100 can be minimized. In addition, light can also be incident on the edge of the object-side surface 112 of the first lens 110. The entire first lens 110 can be an effective area.

[0065] Refer again Figure 1 , among the first to sixth lenses, the object-side surface 112 of the first lens 110 has the smallest effective diameter. According to an embodiment of the present invention, the effective diameter of the object-side surface 112 of the first lens 110 may be smaller than the length in the diagonal direction of the image sensor 180. For example, the effective diameter of the object-side surface 112 of the first lens 110 may be 70% or less of the length in the diagonal direction of the image sensor 180, preferably 50% or less, more preferably 40% or less, and more preferably 30% or less. For example, the effective diameter (ED) of the object-side surface 112 of the first lens 110 L1S1 ) can be 1.422mm to 1.738mm, preferably 1.501mm to 1.659mm, and more preferably 1.55mm to 1.61mm. Figure 2As shown in FIG. 1 , since the aperture ST is set at the edge of the object side surface 112 of the first lens 110, the EPD of the optical system 100 according to the embodiment of the present invention may be 1.422 mm to 1.738 mm, preferably 1.501 mm to 1.659 mm, and more preferably 1.55 mm to 1.61 mm. In the case where the aperture ST is set at the edge of the object side surface 122 of the first lens 110, since the amount of light incident on the first lens 110 can be maximized while minimizing the area of ​​the optical system 100 exposed to the outside, the optical system 100 can be implemented in a compact size. For example, a camera device including the optical system 100 according to the embodiment of the present invention may be implemented so as not to be exposed to the naked eye of the user. For example, the camera device including the optical system 100 according to the embodiment of the present invention may be implemented to be arranged in front of a mobile terminal. For example, the camera device including the optical system 100 according to the embodiment of the present invention may be implemented to be arranged below a display.

[0066] Meanwhile, as the effective diameter of the first lens 110 becomes smaller, the size of the head exposed to the outside can be minimized. However, as the effective diameter of the first lens 110 becomes smaller, the amount of light incident on the optical system 100 may be insufficient. Therefore, when designing an optical system including the first lens 110, it is necessary to consider conditions for brightening an image by reducing the F number and increasing the ratio of the amount of light incident on the periphery of the image sensor to the amount of light incident on the central portion of the image sensor (i.e., relative illumination (RI)).

[0067] Here, the central portion of the image sensor refers to an area close to a zero field of view (0field) of the image sensor, and the periphery of the image sensor refers to an area close to a full field of view (1field) of the image sensor.

[0068] Figure 3 and Figure 4 It is a view used to describe relative illumination.

[0069] Reference Figure 3 , it can be seen that the area reaching the image sensor depends on the incident angle of the light incident from the object side. That is, the image sensor is divided into: a zero field of view area which is the central part of the image sensor and a full field of view area which is the position farthest from the central part of the image sensor, and it can be seen that as the incident angle of the light increases, the light reaches the full field of view area (periphery) closer to the image sensor, and as the incident angle of the light decreases, the light reaches the zero field of view area (central area) closer.

[0070] Reference Figure 4, assuming that the first light ray A is a light ray parallel to the field of view (FOV) of the optical system 100. The first light ray A may be incident on the object-side surface 112 of the first lens 110 to have an angle α relative to the optical axis OA of the first lens 110. In this case, an angle formed by the first light ray A and a normal line (line c) at a point P where the first light ray A and the object-side surface 112 of the first lens 110 contact each other may be defined as an incident angle θ.

[0071] According to an embodiment of the present invention, the lenses forming the optical system 100 are designed to reduce the F number and improve the RI.

[0072] The following Tables 1 and 2 show optical characteristics of lenses included in the optical system according to an embodiment of the present invention, and Tables 3 and 4 show aspherical coefficients of lenses included in the optical system according to an embodiment of the present invention.

[0073] [Table 1]

[0074]

[0075]

[0076] [Table 2]

[0077]

[0078] [Table 3]

[0079]

[0080]

[0081] [Table 4]

[0082]

[0083] In Table 1, the thickness (mm) indicates the distance from each lens surface to the next lens surface. For example, the thickness disclosed for the object side surface 112 of the first lens 110 indicates the distance from the object side surface 122 of the first lens 110 to the image side surface 114. Here, the thickness in Table 1 may refer to the center thickness. The center thickness may refer to the thickness on the optical axis. Specifically, the thickness disclosed for the object side surface 112 of the first lens 110 may indicate the distance between the center of curvature of the object side surface 112 of the first lens 110 and the center of curvature of the image side surface 114. For ease of description, the thickness disclosed for the object side surface of each lens may refer to the center thickness of each lens.

[0084] The thickness disclosed for the image-side surface 114 of the first lens 110 indicates a distance from the image-side surface 114 of the first lens 110 to the object-side surface 122 of the second lens 120. Specifically, the thickness disclosed for the image-side surface 114 of the first lens 110 represents a distance between a center of curvature of the image-side surface 114 of the first lens 110 and a center of curvature of the object-side surface 122 of the second lens 120. For ease of description, the thickness disclosed for the object-side surface of each lens may refer to a distance between two lenses disposed adjacent to each other on the optical axis.

[0085] In the optical system 100 according to an embodiment of the present invention, the first lens 110 , the second lens 120 , and the third lens 130 may be referred to as a first lens group G1 , and the fourth lens 140 , the fifth lens 150 , and the sixth lens 160 may be referred to as a second lens group G2 .

[0086] According to an embodiment of the present invention, among the first to sixth lenses, the fifth lens 150 may have the largest center thickness. The sum of the center thickness of the fourth lens 140 belonging to the second lens group G2 and the center thickness of the sixth lens 160 belonging to the second lens group G2 may be less than the center thickness of the fifth lens 150. According to an embodiment of the present invention, the center thickness of the fifth lens 150 may be 2 times or more, preferably 2.5 times or more, of the center thickness of the fourth lens 140. The center thickness of the fifth lens 150 may be 1.5 times or more, preferably 2 times or more, of the center thickness of the sixth lens 160. According to an embodiment of the present invention, among the first to sixth lenses, the second lens 120 or the fourth lens 140 may have the smallest center thickness.

[0087] According to an embodiment of the present invention, among the first to sixth lenses, the distance between the second lens 120 and the third lens 130 on the optical axis may have the shortest inter-lens distance. According to an embodiment of the present invention, among the first to sixth lenses, the distance between the fifth lens 150 and the sixth lens 160 on the optical axis may have the longest inter-lens distance. According to an embodiment of the present invention, the distance between the second lens 120 and the third lens 130 on the optical axis, the distance between the fourth lens 140 and the fifth lens 150 on the optical axis, the distance between the third lens 130 and the fourth lens 140 on the optical axis, the distance between the first lens and the second lens on the optical axis, and the distance between the fifth lens 150 and the sixth lens 160 on the optical axis may increase in this order. The distance between the fifth lens 150 and the sixth lens 160 on the optical axis may be 1.2 to 2 times, preferably 1.4 to 1.8 times, of the distance between the first lens 110 and the second lens 120 on the optical axis; may be 5 to 6.5 times, preferably 5.5 to 6 times, of the distance between the second lens 120 and the third lens 130 on the optical axis; may be 1.5 to 2.5 times, preferably 1.6 to 2 times, of the distance between the third lens 130 and the fourth lens 140 on the optical axis; and may be 1.5 to 3.5 times, preferably 2 to 3 times, of the distance between the fourth lens 140 and the fifth lens 150 on the optical axis.

[0088] When at least one of the power of the first to sixth lenses, the shape of the lens surface, the center thickness of the lens, and the distance between the lenses satisfies the conditions described above, the first lens group G1 can be used to collect light and correct chromatic aberration, and the second lens group G2 can be used to uniformly diffuse light to each peripheral pixel of the image sensor. That is, according to an embodiment of the present invention, the effective diameter of the object-side surface 112 of the first lens 110 is designed to be smaller than the image sensor 180 to reduce the head size of the optical system 100. When the distance between the lenses in the first lens group G1 satisfies the above conditions, light can be collected without distortion even when the effective diameter of the object-side surface 112 of the first lens 110 is sufficiently small. In addition, when the distance between the first lens group G1 and the second lens group G2 and the distance between the lenses in the second lens group G2 satisfy the above conditions, that is, when the distance between the first lens group G1 and the second lens group G2 and the distance between the lenses in the second lens group G2 are set farther than the distance between the lenses in the first lens group G1, the light collected by the first lens group G1 can pass through the second lens group G2 and uniformly reach each pixel of the image sensor 180 without distortion.

[0089] According to an embodiment of the present invention, the first lens 110, the second lens 120, and the third lens 130 have positive composite power, and the sixth lens 160 disposed closest to the image sensor 180 has negative power. Therefore, the first lens 110, the second lens 120, and the third lens 130 may be used to collect light incident on the object-side surface of the first lens 110, and the sixth lens 160 may be used to diffuse the light so that the light reaches each pixel of the image sensor 180.

[0090] In this case, the first lens 110, the second lens 120, and the third lens 130 may have positive composite power, and the fourth lens 140, the fifth lens 150, and the sixth lens 160 may also have positive composite power. That is, the composite power of the first lens 110, the second lens 120, and the third lens 130 may be 4.72, and the composite power of the fourth lens 140, the fifth lens 150, and the sixth lens 160 may be 16.11. The positive power of the fifth lens 150 may be designed to be strong, so that the composite power of the fourth lens 140, the fifth lens 150, and the sixth lens 160 has positive power while the sixth lens has negative power. For example, the absolute value of the power of the fifth lens 150 having positive power may be set to be greater than the absolute value of the power of the sixth lens 160 having negative power. In the case of the same image sensor, the stronger the positive focal length, that is, the shorter the effective focal length, the wider the FOV may be. As in the embodiment of the present invention, when the first lens 110, the second lens 120, and the third lens 130 have positive compound power, and the fourth lens 140, the fifth lens 150, and the sixth lens 160 have positive compound power, since the power of the first lens group G1 and the second lens group G2 are balanced, a FOV of 90 degrees or more can be obtained while having stable optical performance. Specifically, as in the embodiment of the present invention, when the first lens 110, the second lens 120, and the third lens 130 have positive compound power, the fourth lens 140, the fifth lens 150, and the sixth lens 160 have positive compound power, and the sixth lens 160 has negative power, since the power of the first lens group G1 and the power of the second lens group G2 are balanced, light can uniformly reach each pixel of the image sensor 180 while obtaining a stable FOV of 90 degrees or more. In order to allow the sixth lens 160 to uniformly disperse light to each pixel of the image sensor 180 when the composite power of the second lens group G2 has positive power, the absolute value of the power of the sixth lens 160 having negative power can be designed to be greater than the absolute value of the power of the remaining lenses except the fifth lens 150.

[0091] Specifically, as in an embodiment of the present invention, when the first lens 110 has positive power, the second lens 120 has negative power, the absolute value of the power P1 of the first lens 110 is 2 times or more than the absolute value of the power P2 of the second lens 120, and the center thickness CT1 of the first lens 110 is 1.5 times or more than the center thickness CT2 of the second lens, the first lens 110 can collect light incident on the optical system 100, and the second lens 120 can correct chromatic aberration.

[0092] In addition, when, among the first to sixth lenses, the distance on the optical axis between the fifth lens 150 and the sixth lens 160 included in the second lens group G1 has the longest inter-lens distance and, among the first to sixth lenses, the center thickness of the fifth lens 150 included in the second lens group G1 is the largest, the second lens group G2 can be used to diffuse light more uniformly to the periphery of the image sensor.

[0093] According to an embodiment of the present invention, the total track length (TTL) of the distance from the object side surface 112 of the first lens 110 to the image sensor 180 is 4 mm to 4.5 mm, preferably 4.35 mm, the distance from the object side surface 122 of the second lens 120 to the image sensor 180 is 3.7225 mm, the distance from the object side surface 132 of the third lens 130 to the image sensor 180 is 3.4258 mm, the distance from the object side surface 142 of the fourth lens 140 to the image sensor 180 is 2.8423 mm, the distance from the object side surface 152 of the fifth lens 150 to the image sensor 180 is 2.4197 mm, and the distance from the object side surface 162 of the sixth lens 160 to the image sensor 180 is 1.3016 mm. The diagonal length (2*H) of the image sensor 180 imageD ) is 6.538 mm. In addition, the back focal length (BFL) of the distance from the image side surface 164 of the sixth lens 160 to the image sensor 180 is 0.6 mm or greater. From the perspective of those skilled in the art, when considering assembly performance, the BFL should be implemented as 0.6 mm or greater. For example, in the case where the camera device has an autofocus function, the BFL should be implemented as 0.7 mm or greater for assembly of the optical system and the image sensor, and when the optical system includes a circularly asymmetric lens, the BFL should be implemented as 0.7 mm or greater. Therefore, the optical system 100 can be implemented in a compact size and can be built into the front side as well as the rear side of a mobile terminal.

[0094] According to an embodiment of the present invention, the maximum effective diameter of the lens included in the first lens group G1 may be smaller than the minimum effective diameter of the lens included in the second lens group G2. Here, the effective diameter may refer to the diameter of an effective area of ​​the object side surface or the image side surface on which light is incident.

[0095] In this case, the maximum effective diameter (ED G1_max ) may be the minimum effective diameter (EDG1_ min ) is 1.2 to 2 times, preferably 1.2 to 1.6 times. Since the minimum effective diameter (EDG1_ min ) is the effective diameter of the object side surface 112 of the first lens 110, and therefore, the effective diameters of the image side surface 114 of the first lens 110, the object side surface 122 and the image side surface 124 of the second lens 120, and the object side surface 132 and the image side surface 134 of the third lens 130 may be 1.2 to 2 times the effective diameter of the object side surface 112 of the first lens 110.

[0096] In addition, the effective diameters of the fourth lens 140, the fifth lens 150, and the sixth lens 160 may gradually increase from the object side to the image side. For example, the effective diameter (ED L4S2 ) may be larger than the effective diameter of the object-side surface 142 of the fourth lens 140, and the effective diameter (ED L5S1 ) may be larger than the effective diameter (ED L4S2 ), the effective diameter (ED L5S2 ) may be larger than the effective diameter (ED L5S1 ), the effective diameter (ED L6S1 ) may be larger than the effective diameter (ED L5S2 ), and the effective diameter (ED L6S2 ) may be larger than the effective diameter (ED L6S1 ).

[0097] In addition, the maximum effective diameter (ED G1_max ) may be the effective diameter (ED ) of the image-side surface 164 of the sixth lens 160 L6S2) is 0.7 times or less, preferably 0.6 times or less, and more preferably 0.5 times or less.

[0098] Therefore, the first lens group G1 is used to collect light incident on the optical system 100 to adjust the incident angle of light incident on the second lens group G2. In addition, the second lens group G2 can be used to disperse the light incident on the second lens group G2 after passing through the first lens group G1 to increase the amount of light reaching the periphery of the image sensor 180.

[0099] Figure 5 is design data showing the distance between lens surfaces according to the distance from the optical axis in the Y direction in the optical system according to the embodiment of the present invention, Figure 6 1 is design data showing the concavity value of the lens surface according to the distance from the optical axis in the Y direction in the optical system according to the embodiment of the present invention. Figure 7 is design data showing the inclination angle of the lens surface according to the distance from the optical axis in the Y direction in the optical system according to the embodiment of the present invention. Figures 5 to 7 , L1, L2, L3, L4, L5 and L6 respectively refer to the first lens 110, the second lens 120, the third lens 130, the fourth lens 140, the fifth lens 150 and the sixth lens 160, and L1S1, L1S2, L2S1, L2S2, L3S1, L3S2, L4S1, L4S2, L5S1, L5S2, L6S1 and L6S2 respectively refer to the object side surface 112 and the image side surface 114 of the first lens 110, the object side surface 122 and the image side surface 124 of the second lens 120, the object side surface 132 and the image side surface 134 of the third lens 130, the object side surface 142 and the image side surface 144 of the fourth lens 140, the object side surface 152 and the image side surface 154 of the fifth lens 150, and the object side surface 162 and the image side surface 164 of the sixth lens 160. The air between L1 and L2 represents the distance between the first lens 110 and the second lens 120, the air between L2 and L3 represents the distance between the second lens 120 and the third lens 130, the air between L3 and L4 represents the distance between the third lens 130 and the fourth lens 140, the air between L4 and L5 represents the distance between the fourth lens 140 and the fifth lens 150, and the air between L5 and L6 represents the distance between the fifth lens 150 and the sixth lens 160.

[0100] Reference Figure 5, from the optical axis to the end of the image side surface 114 of the first lens 110, the distance between the image side surface 114 of the first lens 110 and the object side surface 122 of the second lens 120 can be uniformly maintained. Here, the end of the surface of the lens may refer to the end of the effective area of ​​the surface of the lens. Here, the optical axis may refer to a point where the distance along the Y direction is 0. Here, in the case where the ratio of the maximum distance from the optical axis to the end of the surface of the lens between the opposite surfaces of different lenses to the minimum distance is 3 times or less, it can be interpreted that: the distance between the opposite surfaces of different lenses is uniformly maintained.

[0101] That is, the maximum distance (T12 max ) and the minimum distance (T12 min ) can be 3 times or less, and preferably 2 times or less.

[0102] Similarly, the distance between the image side surface 124 of the second lens 120 and the object side surface 132 of the third lens 130 can be uniformly maintained from the optical axis to the end of the image side surface 124 of the first lens 120. That is, the maximum distance (T23 max ) and the minimum distance (T23 min ) can be 3 times or less.

[0103] Similarly, from the optical axis to the end of the image-side surface 134 of the third lens 130, the distance between the image-side surface 134 of the third lens 130 and the object-side surface 142 of the fourth lens 140 can be uniformly maintained. That is, from the optical axis to the end of the image-side surface 134 of the third lens 130, the maximum distance (T34 max ) and the minimum distance (T34 min ) can be 3 times or less, preferably 2 times or less, and more preferably 1.5 times or less.

[0104] Similarly, from the optical axis to the end of the image-side surface 144 of the fourth lens 140, the distance between the image-side surface 144 of the fourth lens 140 and the object-side surface 152 of the fifth lens 150 can be uniformly maintained. That is, from the optical axis to the end of the image-side surface 144 of the fourth lens 140, the maximum distance (T45 max) and minimum distance (T45 min ) can be 3 times or less, preferably 2 times or less.

[0105] At the same time, refer to Figure 6 and Figure 7 According to an embodiment of the present invention, at least one surface of at least one of the first to sixth lenses forming the optical system 100 includes a critical point. The critical point may be located at a point where the trend of the concave value changes. The concave value refers to the distance on the optical axis between any point on the lens surface and a point on the optical axis. Figure 6 In, a positive concave value refers to a shape protruding to the right from the optical axis, and a negative concave value refers to a shape protruding to the left from the optical axis. It is obvious to those skilled in the art that the sign of the concave value can be defined in reverse. For example, a negative concave value may also refer to a shape protruding to the right from the optical axis, and a positive concave value may also refer to a shape protruding to the left from the optical axis. The point at which the trend of the concave value changes may be a point at which the concave value increases and then decreases, or a point at which the concave value decreases and then increases. The critical point may refer to a point at which the tilt angle becomes 0. The tilt angle may be defined as the angle formed by the normal of the tangent to the lens surface and the optical axis.

[0106] According to an embodiment of the present invention, at least one of the six surfaces of the first lens 110, the second lens 120, and the third lens 130 includes a critical point. According to an embodiment of the present invention, the object-side surface 122 of the second lens 120, the image-side surface 124 of the second lens, and the image-side surface 134 of the third lens 130 include a critical point. Light is more effectively refracted near the critical point. That is, light passing through the lens surface including the critical point can be more effectively refracted than light passing through the lens surface not including the critical point. Therefore, when at least one of the six surfaces of the first lens 110, the second lens 120, and the third lens 130 includes a critical point, and in the case where the effective diameter of the object-side surface 112 of the first lens 110 is designed to be small to minimize the head size, or even in the case where the maximum effective diameter of the first lens group G1 is designed to be smaller than the minimum effective diameter of the second lens group G2 to minimize the head size, light incident through the effective diameter of the object-side surface 112 of the first lens 110 can be refracted in as wide a range as possible between the first to third lenses, the light can uniformly reach the peripheral pixels of the image sensor 180, and the performance of the optical system 100 can be improved.

[0107] In addition, according to an embodiment of the present invention, at least two of the six surfaces of the fourth lens 140, the fifth lens 150, and the sixth lens 160 include a critical point. According to an embodiment of the present invention, the object side surface 142 and the image side surface 144 of the fourth lens 140, the object side surface 152 of the fifth lens 150, and the image side surface 164 of the sixth lens 160 may include a critical point. According to an embodiment of the present invention, the image side surface 154 of the fifth lens 150 and the object side surface 162 of the sixth lens 160 may not include a critical point. Light is more effectively refracted near the critical point. In the case where the critical point exists at the periphery of the image side surface 164 of the sixth lens 160, which is the lens surface closest to the image sensor 180, light effectively refracted at the periphery of the image side surface 164 of the sixth lens 160 can easily and uniformly reach the peripheral pixels of the image sensor 180. The periphery may be an area closer to the effective diameter area than the optical axis. Specifically, in the case where the critical point exists on the image-side surface 164 of the sixth lens 160 which is the lens surface closest to the image sensor 180, the assembly performance of the optical system 100 can be improved compared to the case where the critical point exists on the image-side surface or the object-side surface of the first lens 110 which is the lens surface farthest from the image sensor 180. Even when the sixth lens 160 is slightly tilted during assembly, since the assembly of the first lens to the fifth lens of the optical system 100 is not affected and thus the optical performance is not significantly affected, the assembly performance of the optical system 100 can be improved. In the case where the critical point exists on the image-side surface or the object-side surface of the first lens 110 which is the lens surface farthest from the image sensor 180 and the first lens is tilted and assembled during assembly, since the tilt of the assembly has an influence on the second lens and the fifth lens which are the remaining lenses, the performance of the optical system is significantly reduced.

[0108] More specifically, according to an embodiment of the present invention, the critical point of the object-side surface 122 of the second lens 120 may be a point having a vertical distance of 0.6 mm to 0.7 mm from the optical axis. For example, when the optical axis is the starting point and the end of the object-side surface 122 of the second lens 120 is the end point, the critical point of the object-side surface 122 of the second lens 120 may be set at a position of about 68% to 82%. Here, the end of the surface of the lens may refer to the end of the effective area of ​​the surface of the lens, and the position of the critical point may be at a position set based on a direction perpendicular to the optical axis.

[0109] According to an embodiment of the present invention, the critical point of the image side surface 124 of the second lens 120 may be a point having a vertical distance of 0.8 mm to 0.9 mm from the optical axis. For example, when the optical axis is the starting point and the end of the image side surface 124 of the second lens 120 is the end point, the critical point of the image side surface 124 of the second lens 120 may be set at a position of about 80% to 94%.

[0110] According to an embodiment of the present invention, the critical point of the image side surface 134 of the third lens 130 may be a point having a vertical distance of 0.5 mm to 0.6 mm from the optical axis. For example, when the optical axis is the starting point and the end of the image side surface 134 of the third lens 130 is the end point, the critical point of the image side surface 134 of the third lens 130 may be set at a position of about 44% to 56%. According to an embodiment of the present invention, the image side surface 134 of the third lens 130 may also include other critical points. For example, when the optical axis is the starting point and the end of the image side surface 134 of the third lens 130 is the end point, the image side surface 134 of the third lens 130 may also be set in a region of 0.7 mm to 0.8 mm from the optical axis, that is, set at a position of about 62% to 74%.

[0111] According to an embodiment of the present invention, the critical point of the object-side surface 142 of the fourth lens 140 may be a point having a vertical distance of 0.8 mm to 0.9 mm from the optical axis. For example, in a case where the optical axis is the starting point and the end of the object-side surface 142 of the fourth lens 140 is the end point, the critical point of the object-side surface 142 of the fourth lens 140 may be set at a position of about 68% to 78%.

[0112] According to an embodiment of the present invention, the critical point of the image-side surface 144 of the fourth lens 140 may be a point having a vertical distance of 0.9 mm to 1 mm from the optical axis. For example, with the optical axis as the starting point and the end of the image-side surface 144 of the fourth lens 140 as the end point, the critical point of the image-side surface 144 of the fourth lens 140 may be set at a position of about 64% to 72%.

[0113] According to an embodiment of the present invention, the critical point of the object-side surface 152 of the fifth lens 150 may be a point having a vertical distance of 0.9 mm to 1 mm from the optical axis. For example, in a case where the optical axis is the starting point and the end of the object-side surface 152 of the fifth lens 150 is the end point, the critical point of the object-side surface 152 of the fifth lens 150 may be set at a position of about 60% to 68%.

[0114] According to an embodiment of the present invention, the critical point of the image side surface 164 of the sixth lens 160 may be a point having a vertical distance of 1.3 mm to 1.4 mm from the optical axis. For example, with the optical axis as the starting point and the end of the image side surface 164 of the sixth lens 160 as the end point, the critical point of the image side surface 164 of the sixth lens 160 may be set at a position of about 52% to 60%.

[0115] Therefore, when there are critical points on three of the six surfaces of the first to third lenses included in the first lens group G1, light may be uniformly diffused in the first lens group G1, output through the image-side surface 134 of the third lens 130 of the first lens group G1, and incident on the object-side surface 142 of the fourth lens 140. Specifically, when there are two or more critical points on the image-side surface 134 of the third lens 130, light output through the image-side surface 134 of the third lens 130 of the first lens group G1 may be more uniformly incident on the object-side surface 142 of the fourth lens 140.

[0116] According to an embodiment of the present invention, the image side surface 144 of the fourth lens 140 and the object side surface 152 of the fifth lens 150 each include a critical point, the image side surface 154 of the fifth lens 150 and the object side surface 162 of the sixth lens 160 both do not include a critical point, and the image side surface 164 of the sixth lens 160 includes a critical point.

[0117] In this case, the vertical distance from the optical axis to the critical point of the image-side surface 144 of the fourth lens 140 may be 0.9 to 1.1 times, preferably 0.95 to 1.05 times, more preferably 0.97 to 1.3 times, and more preferably 0.99 to 1.01 times, of the vertical distance from the optical axis to the critical point of the object-side surface 152 of the fifth lens 140. In addition, the vertical distance from the optical axis to the critical point of the image-side surface 164 of the sixth lens 160 may be 1.2 to 1.6 times, preferably 1.3 to 1.5 times, and more preferably 1.35 to 1.45 times, of the vertical distance from the optical axis to the critical point of the image-side surface 144 of the fourth lens 140 or the vertical distance from the optical axis to the critical point of the object-side surface 152 of the fifth lens 140.

[0118] In addition, the image-side surface 154 of the fifth lens 150 not including the critical point is convex to the image side, and the object-side surface 162 of the sixth lens 160 not including the critical point is concave to the object side. In addition, the curvature radius (R L6S1 ) may be the absolute value of the curvature radius (R L5S2) is 1.2 to 1.7 times, preferably 1.3 to 1.6 times, more preferably 1.4 to 1.5 times the absolute value of ).

[0119] When the fourth lens 140, the fifth lens 150, and the sixth lens 160 included in the second lens group G2 satisfy the above conditions, light that is uniformly diffused in the first lens group G1 and output through the image-side surface 134 of the third lens 130 of the first lens group G1 and then incident on the object-side surface 142 of the fourth lens 140 can be uniformly diffused in the second lens group G2 and can be uniformly dispersed, and can then be incident on the image sensor from the center to the periphery.

[0120] According to an embodiment of the present invention, the image-side surface 154 of the fifth lens 150 may have a maximum tilt angle in a range of 0.8 to 1.2 times of a vertical distance from the optical axis to a critical point of the object-side surface 152 of the fifth lens 150. That is, the vertical distance of a point having a maximum tilt angle on the image-side surface 154 of the fifth lens 150 from the optical axis may be 0.8 to 1.2 times of a vertical distance from the optical axis to a critical point of the object-side surface 152 of the fifth lens 140. For example, when the vertical distance from the optical axis to the critical point of the object-side surface 152 of the fifth lens 150 is 0.95 mm, the image-side surface 154 of the fifth lens 150 may have a maximum tilt angle at a point having a vertical distance of 0.76 mm to 1.14 mm from the optical axis. Alternatively, according to an embodiment of the present invention, the image-side surface 154 of the fifth lens 150 may have a maximum tilt angle in a range of 0.8 to 1 times of a vertical distance from the optical axis to a critical point of the object-side surface 152 of the fifth lens 140. In this case, the maximum tilt angle of the image-side surface 154 of the fifth lens 150 may be 20 to 30 degrees, preferably 22 to 28 degrees, and more preferably 24 to 26 degrees.

[0121] When the relationship between the critical point and the tilt angle of the fifth lens 150 satisfies the above conditions, light may be more uniformly dispersed in the fifth lens 150 .

[0122] According to an embodiment of the present invention, the object-side surface 162 of the sixth lens 160 may have a maximum inclination angle within a range of 0.8 to 1.2 times of a vertical distance from the optical axis to a critical point of the image-side surface 164 of the sixth lens 160. Alternatively, the object-side surface 162 of the sixth lens 160 may have a maximum inclination angle within a range of 0.8 to 1 times of a vertical distance from the optical axis to a critical point of the image-side surface 164 of the sixth lens 160. In this case, the maximum inclination angle of the object-side surface 162 of the sixth lens 160 may be 35 to 45 degrees, preferably 37 to 42 degrees, and more preferably 38 to 41 degrees.

[0123] When the relationship between the critical point and the tilt angle of the sixth lens 160 satisfies the above conditions, light can be more uniformly dispersed in the sixth lens 160. In this case, the maximum tilt angle may be 65 degrees or less within a range of 60% to 90% of the effective diameter of the image side surface 164 of the sixth lens 160. Therefore, manufacturing performance can be improved while satisfying optical performance.

[0124] According to an embodiment of the present invention, a maximum inclination angle of an image-side surface 144 of the fourth lens 140 may be greater than a maximum inclination angle of an object-side surface 142 of the fourth lens 140, a maximum inclination angle of an object-side surface 152 of the fifth lens 150 may be greater than a maximum inclination angle of an object-side surface 144 of the fourth lens 140, a maximum inclination angle of an image-side surface 154 of the fifth lens 150 may be greater than a maximum inclination angle of an object-side surface 152 of the fifth lens 150, a maximum inclination angle of an object-side surface 162 of the sixth lens 160 may be greater than a maximum inclination angle of an image-side surface 154 of the fifth lens 150, and a maximum inclination angle of an image-side surface 164 of the sixth lens 160 may be greater than a maximum inclination angle of an object-side surface 162 of the sixth lens 160. In this case, a maximum inclination angle of an image-side surface 164 of the sixth lens 160 may be 65 degrees or less. Therefore, manufacturing and assembling of the lens are easy, and light passing through the second lens group G2 may be uniformly dispersed in an effective area of ​​each lens surface.

[0125] According to an embodiment of the present invention, the center thickness CT5 of the fifth lens 150 may be greater than the thickness of the fifth lens 150 at the end of the object-side surface 152 of the fifth lens 150, that is, the distance between the object-side surface 152 of the fifth lens 150 and the image-side surface 154 of the fifth lens 150. According to an embodiment of the present invention, the center thickness CT5 of the fifth lens 150 may be 2.2 to 3 times, preferably 2.2 to 2.8 times, of the thickness of the fifth lens 150 at the end of the object-side surface 152 of the fifth lens 150.

[0126] According to an embodiment of the present invention, the center thickness CT5 of the fifth lens 150 may be greater than the thickness of the fifth lens 150 at a critical point of the object-side surface 152 of the fifth lens 150, that is, the distance between the object-side surface 152 and the image-side surface 154 of the fifth lens 150 at the critical point of the object-side surface 152 of the fifth lens 150. According to an embodiment of the present invention, the center thickness CT5 of the fifth lens 150 may be 1.3 to 1.9 times, preferably 1.5 to 1.8 times, of the thickness of the fifth lens 150 at the critical point of the object-side surface 152 of the fifth lens 150.

[0127] According to an embodiment of the present invention, the center thickness CT6 of the sixth lens 160 may be smaller than the thickness of the sixth lens 160 at the end of the object-side surface 162 of the sixth lens 160, that is, the distance between the object-side surface 162 and the image-side surface 164 of the sixth lens 160 at the end of the object-side surface 162 of the sixth lens 160. According to an embodiment of the present invention, the center thickness CT6 of the sixth lens 160 may be 0.2 to 0.4 times, preferably 0.25 to 0.35 times, of the thickness of the sixth lens 150 at the end of the object-side surface 162 of the sixth lens 160.

[0128] According to an embodiment of the present invention, the center thickness CT6 of the sixth lens 160 may be greater than the thickness of the sixth lens 160 at the critical point of the image-side surface 164 of the sixth lens 160, that is, the distance between the object-side surface 162 and the image-side surface 164 of the sixth lens 160 at the critical point of the image-side surface 164 of the sixth lens 160. According to an embodiment of the present invention, the center thickness CT6 of the sixth lens 160 may be 0.25 to 0.45 times, preferably 0.3 to 0.4 times, of the thickness of the sixth lens 160 at the critical point of the image-side surface 164 of the sixth lens 160.

[0129] Therefore, manufacturing and assembling of the lens are easy, and light passing through the second lens group G2 can be uniformly dispersed in an effective area of ​​each lens surface.

[0130] The optical system 100 according to the embodiment of the present invention may satisfy at least one of the conditional expressions described below. Therefore, the optical system 100 according to the embodiment of the present invention may have an optical enhancement effect. Specifically, at the half value (H imageD ) is 3.2690 mm, the optical system 100 according to an embodiment of the present invention can obtain optical performance of an effective focal length (EFL) of 3.185 mm, an F number of 2.1 or less, a FOV of 90 degrees or more in the diagonal direction, and an RI of 19% or more in the full field of view.

[0131] [Formula 1]

[0132] 0.9≤ED L1S1 / EPD≤1.1

[0133] Here, ED L1S1is the effective diameter of the object side surface 112 of the first lens 110, and the entrance pupil diameter (EPD) is the diameter of the entrance pupil. Therefore, since the area of ​​the object side surface 112 of the first lens 110 exposed to the outside can be minimized, the head size of the optical system 100 can be minimized. In addition, light can also be incident on the edge of the object side surface 112 of the first lens 110. The entire first lens 110 can be an effective area. Preferably, the ED L1S1 / EPD may be 1 or more and 1.1 or less.

[0134] [Formula 2]

[0135] 1.422mm≤ED L1S1 ≤1.738mm

[0136] Therefore, the head size of the optical system 100 can be minimized.

[0137] [Formula 3]

[0138] 1.422mm≤EPD≤1.738mm

[0139] Therefore, the head size of the optical system 100 can be minimized.

[0140] [Formula 4]

[0141] CT4+CT6 <CT5

[0142] Here, CT4 is the center thickness of the fourth lens 140, CT5 is the center thickness of the fifth lens 150, and CT6 is the center thickness of the sixth lens 160. Therefore, assembly and alignment of the optical system are easy.

[0143] [Formula 5]

[0144] 2CT4≤CT5

[0145] Therefore, assembly and alignment of the optical system are easy, and light collected by the first lens group G1 may pass through the second lens group G2 and uniformly reach each pixel of the image sensor 180 without distortion.

[0146] [Formula 6]

[0147] 1.5CT6≤CT5

[0148] Therefore, assembly and alignment of the optical system are easy, and light collected by the first lens group G1 may pass through the second lens group G2 and uniformly reach each pixel of the image sensor 180 without distortion.

[0149] [Formula 7]

[0150] T23 <T45<T34<T12<T56

[0151] Here, T23 is a distance between the second lens 120 and the third lens 130, T12 is a distance between the first lens 110 and the second lens 120, T45 is a distance between the fourth lens 140 and the fifth lens 150, T34 is a distance between the third lens 130 and the fourth lens 140, and T56 is a distance between the fifth lens 150 and the sixth lens 160. Therefore, even when the effective diameter of the object-side surface 112 of the first lens 110 is sufficiently small, light can be collected by the first lens group G1 without distortion, and the light collected by the first lens group G1 can pass through the second lens group G2 and uniformly reach each pixel of the image sensor 180 without distortion.

[0152] [Formula 8]

[0153] 1.2≤T56 / T12≤2

[0154] Therefore, assembly and alignment of the optical system are easy, light can be collected by the first lens group G1 without distortion even when the effective diameter of the object-side surface 112 of the first lens 110 is sufficiently small, and the light collected by the first lens group G1 can pass through the second lens group G2 and uniformly reach each pixel of the image sensor 180 without distortion. Preferably, T56 / T12 may be 1.4 or more and 1.8 or less.

[0155] [Formula 9]

[0156] 5≤T56 / T23≤6.5

[0157] Therefore, assembly and alignment of the optical system are easy, light can be collected by the first lens group G1 without distortion even when the effective diameter of the object-side surface 112 of the first lens 110 is sufficiently small, and the light collected by the first lens group G1 can pass through the second lens group G2 and uniformly reach each pixel of the image sensor 180 without distortion. Preferably, T56 / T23 may be 5.5 or more and 6 or less.

[0158] [Formula 10]

[0159] 1.5≤T56 / T34≤2.5

[0160] Therefore, assembly and alignment of the optical system are easy, and light collected by the first lens group G1 can pass through the second lens group G2 and uniformly reach each pixel of the image sensor 180 without distortion. Preferably, T56 / T34 may be 1.6 or more and 2 or less.

[0161] [Formula 11]

[0162] 1.5≤T56 / T45≤3.5

[0163] Therefore, assembly and alignment of the optical system are easy, and light passing through the second lens group G2 can uniformly reach each pixel of the image sensor 180 without distortion. Preferably, T56 / T45 may be 1.6 or more and 2 or less.

[0164] [Formula 12]

[0165] 2≤|P1| / |P2|

[0166] Therefore, the first lens 110 collects light incident on the optical system 100, and the second lens 120 may correct chromatic aberration.

[0167] [Formula 13]

[0168] 1.5≤CT1 / CT2

[0169] Therefore, the first lens 110 collects light incident on the optical system 100, and the second lens 120 may correct chromatic aberration.

[0170] [Formula 14]

[0171] 4mm≤TTL≤4.5mm

[0172] Here, TTL is a distance from the object-side surface 112 of the first lens 110 to the image sensor 180. In the case where TTL is less than 4 mm, manufacturability is poor and it may be difficult to achieve a preferred effective focal length, and in the case where TTL exceeds 4.5 mm, the size of the camera device increases, and thus it may be difficult to implement the camera device in a compact size in a mobile terminal.

[0173] [Formula 15]

[0174] 0.6mm≤BFL

[0175] Here, BFL is a distance from the image-side surface 164 of the sixth lens 160 to the image sensor 180. Therefore, assembly of the optical system can be enhanced.

[0176] [Formula 16]

[0177] 1.25≤TTL / EFL≤1.42

[0178] Here, EFL is the effective focal length. Therefore, high-resolution images can be acquired even in a narrow space.

[0179] [Formula 17]

[0180] 1.22≤TTL / H imageD ≤1.38

[0181] Therefore, high-resolution images can be acquired even in a narrow space.

[0182] [Formula 18]

[0183] 2.53≤TTL / EPD≤2.85

[0184] Therefore, the head size of the optical system 100 and the overall size of the camera device can be miniaturized.

[0185] [Formula 19]

[0186] ED G1_max <ED G2_min

[0187] Here, ED G1_max is the maximum effective diameter of the first lens group, and ED G2_min is the minimum effective diameter in the second lens group. Therefore, the first lens group G1 can be used to collect light incident on the optical system 100 to adjust the incident angle of light incident on the second lens group G2. In addition, the second lens group G2 can be used to disperse the light incident on the second lens group G2 after passing through the first lens group G1 to increase the amount of light reaching the periphery of the image sensor 180.

[0188] [Formula 20]

[0189] 1.2≤ED G1_max / ED G1_min ≤1.6

[0190] Here, ED G1_min is the minimum effective diameter in the first lens group. Therefore, the first lens group G1 can be used to collect light incident on the optical system 100 to adjust the incident angle of light incident on the second lens group G2. In addition, the second lens group G2 can also be used to disperse the light incident on the second lens group G2 after passing through the first lens group G1 to increase the amount of light reaching the periphery of the image sensor 180.

[0191] [Formula 21]

[0192] ED L4S1 <ED L4S2 <ED L5S1 <ED L5S2 <ED L6S1 <ED L6S2

[0193] Here, ED L4S1 is the effective diameter of the object-side surface 142 of the fourth lens 140, ED L4S2 is the effective diameter of the image-side surface 144 of the fourth lens 140, ED L5S1is the effective diameter of the object-side surface 152 of the fifth lens 150, ED L5S2 is the effective diameter of the image-side surface 154 of the fifth lens 150, ED L6S1 is the effective diameter of the object-side surface 162 of the sixth lens 160, and ED L6S2 is an effective diameter of the image-side surface 164 of the sixth lens 160. Therefore, the second lens group G2 may be used to disperse light incident on the second lens group G2 after passing through the first lens group G1 to increase the amount of light reaching the periphery of the image sensor 180.

[0194] [Formula 22]

[0195] ED G1_max / ED L6S2 ≤0.7

[0196] Therefore, the first lens group G1 can be used to collect light incident on the optical system 100 to adjust the incident angle of light incident on the second lens group G2. In addition, the second lens group G2 can be used to disperse the light incident on the second lens group G2 after passing through the first lens group G1 to increase the amount of light reaching the periphery of the image sensor 180. Preferably, ED G1_max / ED L6S2 Can be 0.6 or less.

[0197] [Formula 23]

[0198] T12 max / T12 min ≤3

[0199] Here, T12 max is the maximum distance between the image-side surface 114 of the first lens 110 and the object-side surface 122 of the second lens 120, and T12 min is the minimum distance between the image-side surface 114 of the first lens 110 and the object-side surface 122 of the second lens 120. Therefore, light can reach the object-side surface 122 of the second lens 120 from the image-side surface 114 of the first lens 110 without being diffused, and assembly of the optical system is easy.

[0200] [Formula 24]

[0201] T23 max / T23 min ≤3

[0202] Here, T23 max is the maximum distance between the image-side surface 124 of the second lens 120 and the object-side surface 132 of the third lens 130, and T23 minis the minimum distance between the image-side surface 124 of the second lens 120 and the object-side surface 132 of the third lens 130. Therefore, light can reach the object-side surface 132 of the third lens 130 from the image-side surface 124 of the second lens 120 without being diffused, and assembly of the optical system is easy.

[0203] [Formula 25]

[0204] T34 max / T34 min ≤3

[0205] Here, T34 max is the maximum distance between the image-side surface 134 of the third lens 130 and the object-side surface 142 of the fourth lens 140, and T34 min is the minimum distance between the image-side surface 134 of the third lens 130 and the object-side surface 142 of the fourth lens 140. Therefore, light can reach the object-side surface 142 of the fourth lens 140 from the image-side surface 134 of the third lens 130 without being diffused. Preferably, T34 max / T34 min Can be 2 or less.

[0206] [Equation 26]

[0207] T45 max / T45 min ≤3

[0208] Here, T45 max is the maximum distance between the image-side surface 144 of the fourth lens 140 and the object-side surface 152 of the fifth lens 150, and T45 min is the minimum distance between the image-side surface 144 of the fourth lens 140 and the object-side surface 152 of the fifth lens 150. Therefore, light can reach the object-side surface 152 of the fifth lens 150 from the image-side surface 144 of the fourth lens 140 without being diffused. Preferably, T34 max / T34 min Can be 2 or less.

[0209] [Formula 27]

[0210] 0.9≤T_CP L4S2 / T_CP L5S1 ≤1.1

[0211] Here, T_CP L4S2 is the distance from the optical axis to the critical point of the image side surface 144 of the fourth lens 140, T_CP L5S1is the distance from the optical axis to the critical point of the object-side surface 152 of the fifth lens 150. Therefore, the second lens group G2 can be used to effectively refract and disperse the light incident on the second lens group G2 after passing through the first lens group G1, so as to increase the amount of light reaching the periphery of the image sensor 180. In addition, since the light effectively refracted at the critical point of the image-side surface 144 of the fourth lens 140 is effectively refracted again at the critical point of the object-side surface 152 of the fifth lens 150, the effective refraction effect of the light can be maximized. Preferably, T_CP L4S2 / T_CP L5S1 It may be 0.95 or more and 1.05 or less.

[0212] [Equation 28]

[0213] 1.2≤T_CP L6S2 / T_CP L4S2 ≤1.6

[0214] Here, T_CP L6S2 is the distance from the optical axis to the critical point of the image side surface 164 of the sixth lens 160. Therefore, the second lens group G2 can be used to effectively refract and disperse the light incident on the second lens group G2 after passing through the first lens group G1, so as to increase the amount of light reaching the periphery of the image sensor 180. Specifically, since the light effectively refracted at the critical point of the image side surface 144 of the fourth lens 140 is effectively refracted again at the critical point of the image side surface 164 of the sixth lens 160, the effective refraction effect of the light can be maximized.

[0215] [Formula 29]

[0216] 1.2≤T_CP L6S2 / T_CP L5S1 ≤1.6

[0217] Here, T_CP L6S2 is the distance from the optical axis to the critical point of the image-side surface 164 of the sixth lens 160. Since the light effectively refracted at the critical point of the object-side surface 162 of the sixth lens 160 is effectively refracted again at the critical point of the image-side surface 164 of the sixth lens 160, the effective refraction effect of the light can be maximized.

[0218] [Formula 30]

[0219] 1.2≤|R L6S1 | / |R L5S2 |≤1.7

[0220] Here, R L6S1 is the radius of curvature of the object-side surface 162 of the sixth lens 160, R L5S2is the radius of curvature of the image-side surface 154 of the fifth lens 150. Therefore, light incident on the fifth lens 150 can be effectively dispersed by the fifth lens 150 and the sixth lens 160, and alignment of the fifth lens 150 and the sixth lens 160 is easy.

[0221] [Equation 31]

[0222] 0.8≤T_SA L5S2_max / T_CP L5S1 ≤1.2

[0223] Here, T_SA L5S2_max is the vertical distance between the point with the maximum tilt angle on the image-side surface 154 of the fifth lens 150 and the optical axis, and T_CP L5S1 is a vertical distance between a critical point of the object-side surface 152 of the fifth lens 150 and the optical axis. Therefore, light may be more efficiently refracted in the fifth lens 150 and uniformly dispersed to reach each pixel of the image sensor 180.

[0224] [Formula 32]

[0225] 0.8≤T_SA L5S2_max / T_CP L5S1 ≤1

[0226] Here, T_SA L5S2_max is the vertical distance between the point with the maximum tilt angle on the image-side surface 154 of the fifth lens 150 and the optical axis, and T_CP L5S1 is a vertical distance between a critical point of the object-side surface 152 of the fifth lens 150 and the optical axis. Therefore, light may be more efficiently refracted in the fifth lens 150 and uniformly dispersed to reach each pixel of the image sensor 180.

[0227] [Formula 33]

[0228] 20 degrees <SA L5S2_max <30 degrees

[0229] Here, SA L5S2_max is the maximum inclination angle of the image-side surface 154 of the fifth lens 150. This can be satisfied under the conditions of Equation 31 or Equation 32. Therefore, light can be more efficiently refracted in the fifth lens 150 and uniformly dispersed to reach each pixel of the image sensor 180, and manufacturing, assembly, and alignment of the optical system are easy.

[0230] [Equation 34]

[0231] 0.8≤T_SA L6S1_max / T_CP L6S2 ≤1.2

[0232] Here, T_SA L6S1_max is the vertical distance between the point with the maximum inclination angle on the object-side surface 162 of the sixth lens 160 and the optical axis, T_CP L6S2 is a vertical distance between a critical point of the image-side surface 164 of the sixth lens 160 and the optical axis. Therefore, light may be more efficiently refracted in the sixth lens 160 and uniformly dispersed to reach each pixel of the image sensor 180.

[0233] [Formula 35]

[0234] 0.8≤T_SA L6S1_max / T_CP L6S2 ≤1

[0235] Therefore, light may be more efficiently refracted in the sixth lens 160 and uniformly dispersed to reach each pixel of the image sensor 180 .

[0236] [Equation 36]

[0237] 35 degrees <SA L6S1_max <40 degrees

[0238] Here, SA L6S1_max is the maximum inclination angle of the object-side surface 162 of the sixth lens 160. This can be satisfied under the conditions of Equation 34 or Equation 35. Therefore, light can be more efficiently refracted in the sixth lens 160 and uniformly dispersed to reach each pixel of the image sensor 180, and manufacturing, assembly, and alignment of the optical system are easy.

[0239] [Equation 37]

[0240] SA L4S1_max <SA L4S2_max <SA L5S1_max <SA L5S2_max <SA L6S1_max <SA L6S2_max

[0241] Here, SA L4S1_max is the maximum inclination angle of the object-side surface 142 of the fourth lens 140, SA L4S2_max is the maximum tilt angle of the image-side surface 144 of the fourth lens 140, SA L5S1_max is the maximum inclination angle of the object-side surface 152 of the fifth lens 150, SA L5S2_max is the maximum tilt angle of the image-side surface 154 of the fifth lens 150, SA L6S1_max is the maximum inclination angle of the object-side surface 162 of the sixth lens 160, and SA L6S2_maxis the maximum inclination angle of the image-side surface 164 of the sixth lens 160. Therefore, light can be uniformly dispersed by the second lens group G2 and can reach each pixel disposed in the periphery of the image sensor 180, and manufacturing, assembling, and aligning of the optical system are easy.

[0242] [Equation 38]

[0243] SA L6S2_max ≤5 degrees

[0244] Therefore, manufacturing performance can be improved while satisfying optical system performance.

[0245] [Equation 39]

[0246] ET5 <CT5

[0247] Here, ET5 is the thickness of the lens at the end of the fifth lens 150. Therefore, light may be more effectively refracted at the periphery of the fifth lens 150 and uniformly dispersed to uniformly reach each pixel of the periphery of the image sensor 180.

[0248] [Formula 40]

[0249] 2≤CT5 / ET5≤3

[0250] Therefore, light may be more efficiently refracted at the periphery of the fifth lens 150 and uniformly dispersed to uniformly reach each pixel at the periphery of the image sensor 180 .

[0251] [Formula 41]

[0252] 1.3≤CT5 / CPT5≤1.9

[0253] Here, CPT5 is the thickness of the fifth lens 150 at the critical point of the object-side surface 152 of the fifth lens 150. Therefore, light can be more effectively refracted near the critical point of the fifth lens 150 and uniformly dispersed to uniformly reach each pixel of the periphery of the image sensor 180.

[0254] [Formula 42]

[0255] CT6 <ET6

[0256] Here, ET6 is the thickness of the lens at the end of the sixth lens 160. Therefore, light may be more effectively refracted at the periphery of the sixth lens 160 and uniformly dispersed to uniformly reach each pixel at the periphery of the image sensor 180.

[0257] [Formula 43]

[0258] 0.2≤CT6 / ET6≤0.4

[0259] Therefore, light may be more effectively refracted at the periphery of the sixth lens 160 and uniformly dispersed to uniformly reach each pixel at the periphery of the image sensor 180 .

[0260] [Formula 44]

[0261] 0.25≤CPT6 / CPT6≤0.45

[0262] Here, CPT6 is the thickness of the sixth lens 160 at the critical point of the object-side surface 162 of the sixth lens 160. Therefore, light can be more effectively refracted near the critical point of the sixth lens 160 and uniformly dispersed to uniformly reach each pixel of the periphery of the image sensor 180.

[0263] [Formula 45]

[0264] ED L1S1 <2H imageD

[0265] Here, H imageD It is half the diagonal length of the pixel area of ​​the image sensor 170. Therefore, a small head size can be achieved.

[0266] Table 5 shows chief ray angle (CRA) data and RI values, by field, that can be obtained using an optical system according to an embodiment of the present invention, Figure 8 shows the modulation transfer function (MTF) of an optical system using an embodiment of the present invention, and Fig. 9 A distortion grid using an optical system according to an embodiment of the present invention is shown.

[0267] [Table 5]

[0268] Field of view CRA RI(%) 0 0 100.0％ 0.1 7.16987 97.5％ 0.2 14.285 90.9％ 0.3 20.9738 82.1％ 0.4 26.7311 73.2％ 0.5 30.9906 64.6％ 0.6 33.4092 56.1％ 0.7 34.2921 47.0％ 0.8 34.2122 37.2％ 0.9 34.3699 27.4％ 1 34.3861 19.3％

[0269] Referring to Table 5, in the optical system according to the embodiment of the present invention, it can be seen that when the chief ray angle (CRA) is 7 degrees or more, for example, in the range of 7 degrees to 35 degrees, the amount of light at the periphery (full field of view) of the image sensor except for the zero field of view is 19% or more, and the amount of light at the central part (zero field of view) of the image sensor is 100%. Figure 8 , an image can be obtained based on the sharpness of a pixel at a spatial frequency, the pixel can be obtained from an optical system according to an embodiment of the present invention, and reference Fig. 9 , the distortion of the image can be obtained, and the image can be obtained from the optical system according to an embodiment of the present invention.

[0270] Fig.10 FIG. 2 shows an optical system according to another embodiment of the present invention. Figures 1 to 9The descriptions of the same content overlap.

[0271] Reference Fig.10 , an optical system 100 according to an 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 , and a sixth lens 160 which are sequentially arranged from an object side to an image side.

[0272] According to an embodiment of the present invention, the filter 170 and the image sensor 180 may be sequentially disposed after the sixth lens 160 .

[0273] The first lens 110, the second lens 120, the third lens 130, the fourth lens 140, the fifth lens 150 and the sixth lens 160 may be sequentially arranged along the optical axis. The first lens 110, the second lens 120, the third lens 130, the fourth lens 140, the fifth lens 150 and the sixth lens 160 may be circular symmetrical lenses. The first lens 110, the second lens 120, the third lens 130, the fourth lens 140, the fifth lens 150 and the sixth lens 160 may be aspherical lenses. The first lens 110, the second lens 120, the third lens 130, the fourth lens 140, the fifth lens 150 and the sixth lens 160 may each be made of plastic or glass.

[0274] The first lens 110 has a positive refractive power and includes an object-side surface 112 and an image-side surface 114 , and the object-side surface 112 of the first lens 110 may be convex to the object side, and the image-side surface 114 may be concave to the image side.

[0275] The second lens 120 has a negative refractive power and includes an object-side surface 122 and an image-side surface 124 , and the object-side surface 122 of the second lens 120 may be convex to the object side, and the image-side surface 124 may be concave to the image side.

[0276] The third lens 130 has a positive refractive power and includes an object-side surface 132 and an image-side surface 134 , and the object surface 132 of the third lens 130 may be convex to the object side, and the image-side surface 134 may be convex to the image side.

[0277] The fourth lens 140 has a negative refractive power and includes an object-side surface 142 and an image-side surface 144 , and the object-side surface 142 of the fourth lens 140 may be convex with respect to the object side, and the image-side surface 144 may be concave with respect to the image side.

[0278] The fifth lens 150 may have a positive refractive power and include an object-side surface 152 and an image-side surface 154 , and the object-side surface 152 of the fifth lens 150 is convex to the object side, and the image-side surface 154 is convex to the image side.

[0279] The sixth lens 160 has negative refractive power and includes an object-side surface 162 and an image-side surface 164 , and the object-side surface 162 of the sixth lens 160 may be concave with respect to the object side, and the image-side surface 164 may be concave with respect to the image side.

[0280] In an embodiment of the present invention, when the first lens 110 has a positive refractive power, the second lens 120 has a negative refractive power, the third lens 130 has a positive refractive power, the fourth lens 140 has a negative refractive power, the fifth lens 150 has a positive refractive power, and the sixth lens 160 has a negative refractive power, chromatic aberration can be corrected. Although not shown, in another embodiment of the present invention, an aperture ST may be further provided at an edge of the object-side surface 112 of the first lens 110.

[0281] According to an embodiment of the present invention, among the first to sixth lenses, the object-side surface 112 of the first lens 110 has the smallest effective diameter. For example, the effective diameter (ED L1S1 ) may be 1.422 mm to 1.738 mm, preferably 1.501 mm to 1.659 mm, and more preferably 1.55 mm to 1.61 mm. Since the aperture ST is provided at the edge of the object-side surface 112 of the first lens 110, the EPD of the optical system 100 according to the embodiment of the present invention may be 1.422 mm to 1.738 mm, preferably 1.501 mm to 1.659 mm, and more preferably 1.55 mm to 1.61 mm.

[0282] The following Tables 6 and 7 show optical characteristics of lenses included in the optical system according to another embodiment of the present invention, and Tables 8 and 9 show Qcon coefficients of lenses included in the optical system according to another embodiment of the present invention.

[0283] Table 6

[0284]

[0285]

[0286] Table 7

[0287]

[0288] Table 8

[0289]

[0290] Table 9

[0291]

[0292]

[0293] In the optical system 100 according to an embodiment of the present invention, the first lens 110, the second lens 120, and the third lens 130 may be referred to as a first lens group G1, and the fourth lens 140, the fifth lens 150, and the sixth lens 160 may be referred to as a second lens group G2. According to an embodiment of the present invention, among the first to sixth lenses, the fifth lens 150 may have the largest center thickness. The sum of the center thickness of the fourth lens 140 belonging to the second lens group G2 and the center thickness of the sixth lens 160 belonging to the second lens group may be less than the center thickness of the fifth lens 150. According to an embodiment of the present invention, the center thickness of the fifth lens 150 may be 2 times or more of the center thickness of the fourth lens 140. The center thickness of the fifth lens 150 may be 1.5 times or more of the center thickness of the sixth lens 160. According to an embodiment of the present invention, among the first to sixth lenses, the second lens 120 or the fourth lens 140 may have the smallest center thickness.

[0294] According to an embodiment of the present invention, among the first to sixth lenses, the distance on the optical axis between the second lens 120 and the third lens 130 may have the shortest inter-lens distance. According to an embodiment of the present invention, among the first to sixth lenses, the distance on the optical axis between the third lens 130 and the fourth lens 140 or between the fifth lens 150 and the sixth lens 160 may have the longest inter-lens distance. The distance between the fifth lens 150 and the sixth lens 160 on the optical axis may be 1.2 to 2 times, and preferably 1.4 to 1.8 times, of the distance between the first lens 110 and the second lens 120 on the optical axis; the distance between the fifth lens 150 and the sixth lens 160 on the optical axis may be 2.5 to 4.5 times, and preferably 3 to 4 times, of the distance between the second lens 120 and the third lens 130 on the optical axis; the distance between the fifth lens 150 and the sixth lens 160 on the optical axis may be 0.9 to 1.1 times, and preferably 0.95 to 1.05 times, of the distance between the third lens 130 and the fourth lens 140 on the optical axis; and the distance between the fifth lens 150 and the sixth lens 160 on the optical axis may be 1 to 1.5 times, and preferably 1.1 to 1.3 times, of the distance between the fourth lens 140 and the fifth lens 150 on the optical axis.

[0295] When at least one of the power of the first to sixth lenses, the shape of the lens surface, the center thickness of the lens, and the distance between the lenses satisfies the conditions described above, the first lens group G1 can be used to correct chromatic aberration, and the second lens group G2 can be used to uniformly diffuse light to each peripheral pixel of the image sensor.

[0296] According to an embodiment of the present invention, a distance TTL from an object-side surface 112 of the first lens 110 to the image sensor 180 is 4 mm to 4.5 mm, preferably 4.32 mm, a distance from an object-side surface 122 of the second lens 120 to the image sensor 180 is 3.733 mm, a distance from an object-side surface 132 of the third lens 130 to the image sensor 180 is 3.4148 mm, a distance from an object-side surface 142 of the fourth lens 140 to the image sensor 180 is 2.714 mm, a distance from an object-side surface 152 of the fifth lens 150 to the image sensor 180 is 2.2304 mm, and a distance from an object-side surface 162 of the sixth lens 160 to the image sensor 180 is 1.3019 mm. In addition, a distance BFL from an image-side surface 164 of the sixth lens 160 to the image sensor 180 is 0.6 mm or more.

[0297] According to an embodiment of the present invention, the maximum effective diameter of the lens included in the first lens group G1 may be smaller than the minimum effective diameter of the lens included in the second lens group G2. Here, the effective diameter may refer to the diameter of an effective area of ​​the object side surface or the image side surface on which light is incident.

[0298] In this case, the maximum effective diameter (ED G1_max ) may be the minimum effective diameter (ED) of the lenses included in the first lens group G1. G1_min ) is 1.2 to 1.6 times, and preferably 1.3 to 1.5 times.

[0299] In addition, effective diameters of the fourth lens 140 , the fifth lens 150 , and the sixth lens 160 may gradually increase from the object side to the image side.

[0300] In addition, the maximum effective diameter (ED G1_max ) may be the effective diameter (ED ) of the image-side surface 164 of the sixth lens 160 L6S2 ) or less.

[0301] Therefore, the first lens group G1 can be used to collect light incident on the optical system 100 to adjust the incident angle of light incident on the second lens group G2. In addition, the second lens group G2 can be used to disperse the light incident on the second lens group G2 after passing through the first lens group G1 to increase the amount of light reaching the periphery of the image sensor 180.

[0302] Fig.11 is design data showing the distance between lens surfaces according to the distance from the optical axis in the Y direction in the optical system according to another embodiment of the present invention; Fig.12is design data showing concave values ​​according to distances from the optical axis in the Y direction in an optical system according to another embodiment of the present invention; Fig.13 1 is design data showing the inclination angle of the lens surface according to the distance from the optical axis in the Y direction in the optical system according to another embodiment of the present invention.

[0303] Reference Figures 11 to 13 , from the optical axis to the end of the image side surface 114 of the first lens 110, the distance between the image side surface 114 of the first lens 110 and the object side surface 122 of the second lens 120 can be uniformly maintained. That is, from the optical axis to the end of the image side surface 114 of the first lens 110, the maximum distance (T12 max ) and the minimum distance (T12 min ) can be 3 times or less.

[0304] Similarly, the maximum distance (T23 ) between the image-side surface 124 of the second lens 120 and the object-side surface 132 of the third lens 130 is from the optical axis to the end of the image-side surface 124 of the second lens 120. max ) and the minimum distance (T23 min ) can be 3 times or less.

[0305] Similarly, the maximum distance (T34 ) between the image-side surface 134 of the third lens 130 and the object-side surface 142 of the fourth lens 140 is from the optical axis to the end of the image-side surface 134 of the third lens 130. max ) and the minimum distance (T34 min ) can be 3 times or less, preferably 2 times or less, and more preferably 1.5 times or less.

[0306] Similarly, the maximum distance (T45 ) between the image-side surface 144 of the fourth lens 140 and the object-side surface 152 of the fifth lens 150 is from the optical axis to the end of the image-side surface 144 of the fourth lens 140. max ) and minimum distance (T45 min ) can be 3 times or less, and preferably 2 times or less.

[0307] Meanwhile, according to an embodiment of the present invention, at least one surface of at least one of the first to sixth lenses forming the optical system 100 includes a critical point. At least one of the six surfaces of the first lens 110, the second lens 120, and the third lens 130 includes a critical point. According to an embodiment of the present invention, the object-side surface 122 of the second lens 120, the image-side surface 124 of the second lens 120, and the image-side surface 134 of the third lens 130 include a critical point.

[0308] In addition, according to an embodiment of the present invention, at least two of the six surfaces of the fourth lens 140, the fifth lens 150, and the sixth lens 160 include a critical point. According to an embodiment of the present invention, the object-side surface 142 and the image-side surface 144 of the fourth lens 140, the object-side surface 152 of the fifth lens 150, and the image-side surface 164 of the sixth lens 160 may include a critical point. According to an embodiment of the present invention, the image-side surface 154 of the fifth lens 150 and the object-side surface 162 of the sixth lens 160 may not include a critical point.

[0309] More specifically, according to an embodiment of the present invention, the critical point of the object-side surface 122 of the second lens 120 may be a point having a vertical distance of 0.5 mm to 0.6 mm from the optical axis.

[0310] According to an embodiment of the present invention, the critical point of the image-side surface 124 of the second lens 120 may be a point having a vertical distance of 0.8 mm to 0.9 mm from the optical axis.

[0311] According to an embodiment of the present invention, the critical point of the image-side surface 134 of the third lens 130 may be a point having a vertical distance of 0.8 mm to 0.9 mm from the optical axis.

[0312] According to an embodiment of the present invention, the critical point of the object-side surface 142 of the fourth lens 140 may be a point having a vertical distance of 0.7 mm to 0.8 mm from the optical axis.

[0313] According to an embodiment of the present invention, the critical point of the image-side surface 144 of the fourth lens 140 may be a point having a vertical distance of 0.8 mm to 0.9 mm from the optical axis.

[0314] According to an embodiment of the present invention, the critical point of the object-side surface 152 of the fifth lens 150 may be a point having a vertical distance of 0.6 mm to 0.7 mm from the optical axis.

[0315] According to an embodiment of the present invention, the critical point of the image-side surface 164 of the sixth lens 160 may be a point having a vertical distance of 1.3 mm to 1.4 mm from the optical axis.

[0316] Therefore, in the case where critical points exist on three of the six surfaces of the first lens to the third lens included in the first lens group G1, light can be uniformly dispersed in the first lens group G1, output through the image-side surface 134 of the third lens 130 of the first lens group G1, and incident on the object-side surface 142 of the fourth lens 140.

[0317] According to an embodiment of the present invention, the image side surface 144 of the fourth lens 140 and the object side surface 152 of the fifth lens 150 each include a critical point, the image side surface 154 of the fifth lens 150 and the object side surface 162 of the sixth lens 160 both do not include a critical point, and the image side surface 164 of the sixth lens 160 includes a critical point.

[0318] In addition, the image-side surface 154 of the fifth lens 150 not including the critical point is convex to the image side, and the object-side surface 162 of the sixth lens 160 not including the critical point is concave to the object side. In addition, the curvature radius (R L6S1 ) may be the absolute value of the curvature radius (R L5S2 ) is 1.2 to 1.7 times, and preferably 1.3 to 1.6 times, the absolute value of ).

[0319] When the fourth lens 140, the fifth lens 150, and the sixth lens 160 included in the second lens group G2 satisfy the above conditions, light that is uniformly dispersed in the first lens group G1 and output through the image-side surface 134 of the third lens 130 of the first lens group G1 and then incident on the object-side surface 142 of the fourth lens 140 can be uniformly diffused and uniformly dispersed in the second lens group G2, and can then be incident on the image sensor from the center to the periphery.

[0320] According to an embodiment of the present invention, the maximum tilt angle of the image side surface 154 of the fifth lens 150 may be 20 to 30 degrees, preferably 22 to 28 degrees, and more preferably 24 to 26 degrees. The maximum tilt angle of the image side surface 154 of the fifth lens 150 may occur at a distance of 0.9 mm to 1.1 mm relative to the optical axis. That is, the maximum tilt angle of the image side surface 154 of the fifth lens 150 may occur at a distance between 51% and 63% from the optical axis to the end of the image side surface 154 of the fifth lens 150.

[0321] According to an embodiment of the present invention, the object-side surface 162 of the sixth lens 160 may have a maximum inclination angle within a range of 0.8 to 1.2 times of a vertical distance from the optical axis to a critical point of the image-side surface 164 of the sixth lens 160. Alternatively, the object-side surface 162 of the sixth lens 160 may have a maximum inclination angle within a range of 0.8 to 1 times of a vertical distance from the optical axis to a critical point of the image-side surface 164 of the sixth lens 160. In this case, the maximum inclination angle of the object-side surface 162 of the sixth lens 160 may be 35 to 45 degrees, and preferably 37 to 42 degrees.

[0322] When the relationship between the critical point and the tilt angle of the sixth lens 160 satisfies the above conditions, light may be more uniformly dispersed in the sixth lens 160 .

[0323] According to an embodiment of the present invention, the maximum inclination angle of the image side surface 164 of the sixth lens 160 may be 65 degrees or less. Therefore, the manufacture and assembly of the lens are easy, and the light passing through the second lens group G2 may be uniformly dispersed in the effective area of ​​each lens surface.

[0324] According to an embodiment of the present invention, the center thickness CT5 of the fifth lens 150 may be greater than the thickness of the fifth lens 150 at an end of the object-side surface 152 of the fifth lens 150, that is, the distance between the object-side surface 152 and the image-side surface 154 of the fifth lens 150 at the end of the object-side surface 152 of the fifth lens 150. According to an embodiment of the present invention, the center thickness CT5 of the fifth lens 150 may be 1.5 to 3 times the thickness of the fifth lens 150 at the end of the object-side surface 152 of the fifth lens 150.

[0325] According to an embodiment of the present invention, the center thickness CT5 of the fifth lens 150 may be greater than the thickness of the fifth lens 150 at a critical point of the object-side surface 152 of the fifth lens 150, that is, the distance between the object-side surface 152 and the image-side surface 154 of the fifth lens 150 at the critical point of the object-side surface 152 of the fifth lens 150. According to an embodiment of the present invention, the center thickness CT5 of the fifth lens 150 may be 1.2 to 1.4 times the thickness of the fifth lens 150 at the critical point of the object-side surface 152 of the fifth lens 150.

[0326] According to an embodiment of the present invention, the center thickness CT6 of the sixth lens 160 may be smaller than the thickness of the sixth lens 160 at the end of the object-side surface 162 of the sixth lens 160, that is, the distance between the object-side surface 162 of the sixth lens 160 and the image-side surface 164 at the end of the object-side surface 162 of the sixth lens 160. According to an embodiment of the present invention, the center thickness CT6 of the sixth lens 160 may be 0.2 to 0.4 times, and preferably 0.25 to 0.35 times, of the thickness of the sixth lens 160 at the end of the object-side surface 162 of the sixth lens 160.

[0327] According to an embodiment of the present invention, the center thickness CT6 of the sixth lens 160 may be greater than the thickness of the sixth lens 160 at the critical point of the image-side surface 164 of the sixth lens 160, that is, the distance between the object-side surface 162 and the image-side surface 164 of the sixth lens 160 at the critical point of the image-side surface 164 of the sixth lens 160. According to an embodiment of the present invention, the center thickness CT6 of the sixth lens 160 may be 0.25 to 0.45 times, and preferably 0.3 to 0.4 times, of the thickness of the sixth lens 160 at the critical point of the image-side surface 164 of the sixth lens 160.

[0328] Therefore, manufacturing and assembling of the lens are easy, and light passing through the second lens group G2 can be uniformly dispersed in effective areas of respective lens surfaces.

[0329] Referring to Table 10, chief ray angle (CRA) data and RI values ​​that can be obtained using an optical system according to another embodiment of the present invention are shown by field of view; Fig.14 shows a modulation transfer function (MTF) of an optical system using another embodiment of the present invention; and Fig.15 A distortion grid using an optical system according to another embodiment of the present invention is shown.

[0330] [Table 10]

[0331]

[0332]

[0333] Referring to Table 5, it can be seen that in the optical system according to the embodiment of the present invention, when the chief ray angle (CRA) is 7 degrees or more, for example, in the range of 7 degrees to 37 degrees, the amount of light at the peripheral portion of the image sensor (full field of view) excluding the zero field of view is 19% or more, and the amount of light at the central portion of the image sensor (zero field of view) is 100%. Fig.14, the sharpness of the image in the spatial frequency according to the pixel can be obtained, and the pixel can be obtained from the optical system according to another embodiment of the present invention; and referring to Fig.15 , the degree of distortion of an image can be obtained, and the image can be obtained from an optical system according to another embodiment of the present invention.

[0334] The optical system 100 according to another embodiment of the present invention can obtain optical performance, wherein: the effective focal length (EFL) is 3.478 mm; the F number is 2.3 or less; the FOV in the diagonal direction is 86 degrees or more; and the diagonal length (H) of the pixel area of ​​the image sensor 180 is 1.367 mm. imageD ) is 3.2690 mm, and the RI in the full field of view is 19% or greater.

[0335] Fig.16 is a view showing a portion of a mobile terminal to which a camera device according to an embodiment of the present invention is applied.

[0336] Meanwhile, the optical system 100 according to an embodiment of the present invention may be applied to a camera device 1000. The camera device 1000 including the optical system 100 according to an embodiment of the present invention may be built into a mobile terminal and applied together with a main camera module. The camera device 1000 according to an embodiment of the present invention may include an image sensor, an optical filter disposed on the image sensor, and an optical system 100 disposed on the optical filter, and the optical system 100 according to an embodiment of the present invention may include the first lens 110, the second lens 120, the third lens 130, the fourth lens 140, and the fifth lens 150 described above. The mobile terminal having a built-in camera device including the optical system according to an embodiment of the present invention may be a smart phone, a tablet personal computer (PC), a laptop computer, a personal digital assistant (PDA), etc.

[0337] The optical system 100 according to the embodiment of the present invention may be disposed at the front side or the rear side of the mobile terminal, or may be disposed under the display of the mobile terminal.

[0338] Due to the thickness limitation of the mobile terminal, the optical system 100 according to the embodiment of the present invention may be sequentially arranged in the lateral direction of the mobile terminal. To this end, as described above, a right angle prism may be further arranged at the front end of the first lens 110.

[0339] The mobile terminal may be a smart phone, a tablet PC, a laptop computer, a PDA, or the like.

[0340] Although the above mainly describes the embodiments, these are only examples and are not intended to limit the present invention, and it can be seen that those skilled in the art can make various modifications and applications not illustrated herein without departing from the essential features of the present invention. For example, each component in the components specifically shown in the embodiments can be modified and implemented. In addition, it should be understood that the differences related to the modifications and applications are included in the scope of the present invention defined by the appended claims.

[0341] [reference numerals]

[0342] 100: Optical system

[0343] 110: First lens

[0344] 120: Second lens

[0345] 130: The third lens

[0346] 140: The fourth lens

[0347] 150: Fifth lens

[0348] 160: Sixth lens

[0349] 170: Filter

[0350] 180: Image sensor

Claims

1. An optical system comprising a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens arranged in sequence from an object side to an image side, in, the first lens has positive refractive power, the second lens has negative refractive power, the third lens has positive refractive power, the fourth lens has negative refractive power, the fifth lens has positive refractive power, and the sixth lens has negative refractive power, an object-side surface of the sixth lens is concave toward the object side, and an image-side surface of the fifth lens is convex toward the image side, The object-side surface of the fifth lens and the image-side surface of the sixth lens include a critical point where the inclination angle is 0, and The object-side surface of the sixth lens has a maximum inclination angle within a range of 0.8 times to 1.2 times a perpendicular distance from an optical axis to the critical point of the image-side surface of the sixth lens.

2. The optical system according to claim 1, wherein: The image-side surface of the fifth lens has a maximum inclination angle within a range of 0.8 times to 1.2 times a perpendicular distance from the optical axis to the critical point of the object-side surface of the fifth lens.

3. The optical system of claim 2, wherein: The maximum inclination angle of the image-side surface of the fifth lens is 20 degrees to 30 degrees within a range of 0.8 times to 1.2 times a vertical distance from the optical axis to the critical point of the object-side surface of the fifth lens; and The maximum inclination angle of the object-side surface of the sixth lens is 35 degrees to 45 degrees within a range of 0.8 times to 1.2 times a perpendicular distance from the optical axis to the critical point of the image-side surface of the sixth lens.

4. The optical system according to claim 1, wherein: An absolute value of a radius of curvature of the object-side surface of the sixth lens is 1.2 to 1.5 times an absolute value of a radius of curvature of the image-side surface of the fifth lens.

5. The optical system of claim 1, wherein: The image-side surface of the fourth lens includes the critical point; and A vertical distance from the optical axis to a critical point of the image-side surface of the fourth lens is 0.9 to 1.1 times a vertical distance from the optical axis to the critical point of the object-side surface of the fifth lens.

6. The optical system according to claim 5, wherein: A vertical distance from the optical axis to the critical point of the image-side surface of the sixth lens is 1.2 to 1.6 times a vertical distance from the optical axis to the critical point of the image-side surface of the fourth lens or a vertical distance from the optical axis to the critical point of the object-side surface of the fifth lens.

7. The optical system according to claim 1, wherein: A center thickness of the fifth lens is greater than a thickness of the fifth lens at the critical point of the object-side surface of the fifth lens.

8. The optical system according to claim 7, wherein: A center thickness of the sixth lens is smaller than a thickness of the sixth lens at the critical point of the image-side surface of the sixth lens.

9. The optical system according to claim 1, wherein: An aperture is provided at an edge of an object-side surface of the first lens.

10. The optical system according to claim 1, wherein: The F number is 2.1 or less, the field of view (FOV) is 90 degrees or more, and the relative illumination (RI) is 19% or more.

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