Optical system and camera apparatus 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 arranged in order from an object side to an image side, the fifth lens has a positive refractive power, the sixth lens has a negative refractive power, and a diameter of the first lens is 90% to 110% of an entrance pupil diameter (EPD).

Description

Technical Field

[0001] Embodiments of the present invention relate to an optical system and a camera apparatus 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 has further increased. 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 may 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 having 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] The 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 sequentially arranged 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 diameter of the first lens is 90% to 110% of the entrance pupil diameter (EPD).

[0009] The aperture may be provided at an edge of the object-side surface of the first lens.

[0010] The image side surface of the fifth lens may be convex toward the image side, the object side surface of the sixth lens may be concave toward the object side, and the distance between the image side surface of the fifth lens and the object side surface of the sixth lens may decrease as they move away from the optical axis to a specific distance.

[0011] The image side surface of the fifth lens may be convex toward the image side, the object side surface of the sixth lens may be concave toward the object side, and a maximum inclination angle of the object side surface of the sixth lens may be greater than a maximum inclination angle of the image side surface of the fifth lens from the optical axis to a specific distance.

[0012] A ratio of an absolute value of a radius of curvature of the object-side surface of the sixth lens to an absolute value of a radius of curvature of the image-side surface of the fifth lens may be 2 to 3.

[0013] At least one of the object-side surface of the second lens, the image-side surface of the third lens, the object-side surface of the fourth lens, the image-side surface of the fourth lens, the object-side surface of the fifth lens, and the image-side surface of the sixth lens may include a critical point.

[0014] An object-side surface of the fourth lens and an image-side surface of the fourth lens may each include a critical point.

[0015] The object-side surface of the fifth lens may include a critical point.

[0016] A vertical distance from the optical axis to a critical point of the object-side surface of the fourth lens may be 0.9 to 1.1 times a vertical distance from the optical axis to a critical point of the image-side surface of the fourth lens, and may be 0.9 to 1.1 times a vertical distance from the optical axis to a critical point of the object-side surface of the fifth lens.

[0017] The specific distance may be a perpendicular distance between at least one of a critical point of an object-side surface of the fourth lens, a critical point of an image-side surface of the fourth lens, and a critical point of an object-side surface of the fifth lens and the optical axis.

[0018] The F number may be 2 or less, the field of view (FOV) may be 84 degrees or more, and the relative illumination (RI) may be 25% or more.

[0019] According to another embodiment of the present invention, an optical system includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens which are sequentially arranged 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 first lens has the smallest diameter among the first to sixth lenses, the object side surface of the fourth lens, the image side surface of the fourth lens and the object side surface of the fifth lens all include a critical point, the image side surface of the fifth lens is convex toward the image side, the object side surface of the sixth lens is concave toward the object side, and the absolute value of the radius of curvature of the image side surface of the fifth lens is greater than the absolute value of the radius of curvature of the object side surface of the sixth lens.

[0020] A vertical distance from the optical axis to a critical point of the object-side surface of the fourth lens may be 0.9 to 1.1 times a vertical distance from the optical axis to a critical point of the image-side surface of the fourth lens, and may be 0.9 to 1.1 times a vertical distance from the optical axis to a critical point of the object-side surface of the fifth lens.

[0021] For the vertical distance between at least one of the critical point of the object side surface of the fourth lens, the critical point of the image side surface of the fourth lens and the object side surface of the fifth lens and the optical axis, the maximum inclination angle with respect to the object side surface of the sixth lens can be greater than the maximum inclination angle with respect to the image side surface of the fifth lens.

[0022] A camera device according to an embodiment of the present invention 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 sequentially from an object side to an 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, and a diameter of the first lens is 90% to 110% of an entrance pupil diameter (EPD).

[0023] Beneficial Effects

[0024] 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 while being implemented in a compact size can be obtained.

[0025] According to an embodiment of the present invention, a camera device having an F number of 2 or less, a FOV of 84 degrees or more, and an RI in 1 field of 25% or more while being implemented in a small size can be obtained.

[0026] 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 at the periphery of the sensor while designing the diameter of the first lens (i.e., the lens disposed closest to the object side) to be small. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 An optical system according to an embodiment of the present invention is shown.

[0028] 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.

[0029] Figure 3 and Figure 4 It is a view used to describe relative illumination.

[0030] 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.

[0031] Figure 6 1 is design data showing the sag 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.

[0032] 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.

[0033] Figure 8 The modulation transfer function (MTF) of an optical system using one embodiment of the present invention is shown.

[0034] Fig. 9 A distortion grid using an optical system according to one embodiment of the present invention is shown.

[0035] Fig.10 is a view showing a portion of a mobile terminal to which a camera device according to one embodiment of the present invention is applied. DETAILED DESCRIPTION

[0036] Hereinafter, exemplary embodiments according to the present invention will be described in detail with reference to the accompanying drawings.

[0037] 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.

[0038] 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.

[0039] Furthermore, the terms used in the embodiments of the present invention are provided not to limit the present invention but to describe the embodiments.

[0040] 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.

[0041] Furthermore, terms such as first, second, A, B, (a), (b), etc. may be used to describe components of embodiments of the present invention.

[0042] 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.

[0043] 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 the case where the component is directly connected, coupled, or linked to another component, but also the case where the component is connected, coupled, or linked to another component via another component between the element and the other components.

[0044] 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.

[0045] Figure 1 An optical system according to an embodiment of the present invention is shown.

[0046] 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 disposed from an object side to an image side.

[0047] Although not shown, a right angle prism may be further disposed in front of the first lens 110 .

[0048] 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, that is, an area through which the incident light is refracted to achieve optical characteristics. In this specification, the effective diameter may mean the diameter of the effective area through which the effective light is incident on each surface of each lens. In this specification, the value of the effective diameter may have a certain error range. For example, for the value of the effective diameter presented in this specification, the range of ±0.4mm may be considered as the effective area. For the value of the effective diameter presented in this specification, the range of ±0.4mm may be interpreted as the effective diameter. The ineffective area is set at the periphery of the effective area and may be an area where light is not incident, that is, an area that is not related to the optical characteristics. The ineffective area may be an area fixed to a lens barrel or the like that houses the lens.

[0049] 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 with 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.

[0050] 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 which are sequentially arranged 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 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 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 be made of plastic or glass.

[0051] 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 toward the object side, and the image side surface 114 may be concave toward the image side. Here, the case where the lens surface is convex may mean 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 mean 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 mean an optical axis region or a paraxial region. In addition, the case where the surface of the lens is convex toward the object side may mean that the surface of the lens is concave toward the image side, and the case where the surface of the lens is convex toward the image side may mean that the surface of the lens is concave toward the object side.

[0052] 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 toward the object side, and the image-side surface 124 may be concave toward the image side.

[0053] 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 toward the object side, and the image-side surface 134 may be convex toward the image side.

[0054] 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 toward the object side, and the image-side surface 144 may be concave toward the image side.

[0055] 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 toward the object side, and the image-side surface 154 is convex toward the image side.

[0056] 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 toward the object side, and the image-side surface 164 may be concave toward the image side.

[0057] 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.

[0058] 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.

[0059] 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 an 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%.

[0060] 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.

[0061] Refer again Figure 1 , the object-side surface 112 or the image-side surface 114 of the first lens 110 has the smallest effective diameter among the first to sixth lenses 110, . . . and 160. For example, the effective diameter (ED L1S1 ) may be 1.62 mm to 1.98 mm, and preferably 1.7 mm to 1.9 mm. 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 170. 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 170, preferably 50% or less, more preferably 40% or less, and more preferably 30% or less. Therefore, while the first lens 110 can be manufactured, the head size of the optical system 100 can be reduced. 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 1.62 mm to 1.98 mm, and preferably 1.7 mm to 1.9 mm. In the case where the aperture ST is set at the edge of the object-side surface 112 of the first lens 110, since the amount of light incident on the first lens 110 can be maximized while minimizing the area where the optical system 100 is 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, a camera device including the optical system 100 according to the embodiment of the present invention may be implemented so as to be set in front of a mobile terminal. For example, a camera device including the optical system 100 according to the embodiment of the present invention may be implemented so as to be set below a display.

[0062] 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 a condition 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, that is, relative illumination (RI).

[0063] Here, the central portion of the image sensor means an area close to the 0 field of the image sensor, and the periphery of the image sensor means an area close to the 1 field of the image sensor.

[0064] Figure 3 and Figure 4 It is a view used to describe relative illumination.

[0065] Reference Figure 3 , it can be seen that the area reaching the image sensor changes depending on the incident angle of light incident from the object side. That is, the image sensor is divided into: the 0 field area which is the central part of the image sensor and the 1 field 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 light increases, the light arrives closer to the 1 field area (periphery) of the image sensor, and as the incident angle of light decreases, the light arrives closer to the 0 field area (central part).

[0066] 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.

[0067] 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.

[0068] 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.

[0069] [Table 1]

[0070]

[0071] [Table 2]

[0072]

[0073]

[0074] [Table 3]

[0075]

[0076] [Table 4]

[0077]

[0078]

[0079] 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 112 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.

[0080] 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 the center of curvature of the image-side surface 114 of the first lens 110 and the center of curvature of the object-side surface 122 of the second lens 120. For ease of description, the thickness disclosed for the image-side surface of each lens may refer to a distance between two lenses disposed adjacent to each other on the optical axis.

[0081] 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 .

[0082] According to an embodiment of the present invention, the second lens 120 or the fourth lens 140 may have the smallest center thickness among the first to sixth lenses. The fifth lens 150 may have the largest center thickness among the first to sixth lenses. According to an embodiment of the present invention, the center thickness of the fifth lens 150 may be 2 times or more, and preferably 2 times to 3 times, that of the fourth lens 140. Therefore, assembly and alignment of the first to sixth lenses are easy.

[0083] According to an embodiment of the present invention, the distance on the optical axis between the second lens 120 and the third lens 130 may have the shortest inter-lens distance among the first lens to the sixth lens. According to an embodiment of the present invention, the distance on the optical axis between the fifth lens 150 and the sixth lens 160 may have the longest inter-lens distance among the first lens to the sixth lens. According to an embodiment of the present invention, the distance on the optical axis between the second lens 120 and the third lens 130, the distance on the optical axis between the first lens 110 and the second lens 120, the distance on the optical axis between the fourth lens 140 and the fifth lens 150, the distance on the optical axis between the third lens 130 and the fourth lens 140, and the distance on the optical axis between the fifth lens 150 and the sixth lens 160 may increase in this order. The distance between the fifth lens 150 and the sixth lens 160 on the optical axis may be 1.6 to 2.6 times, and preferably 1.9 to 2.3 times, of the distance between the first lens 110 and the second lens 120 on the optical axis, may be 8 to 12 times, and preferably 9 to 11 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, and 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 2.5 times, and preferably 1.6 to 2 times, of the distance between the fourth lens 140 and the fifth lens 150 on the optical axis.

[0084] 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 G 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 G 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.

[0085] 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 fourth lens 140, the fifth lens 150, and the sixth lens 160 have negative composite power. That is, the composite power of the first lens 110, the second lens 120, and the third lens 130 may be 0.23, and the composite power of the fourth lens 140, the fifth lens 150, and the sixth lens 160 may be -0.06. 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 fourth lens 140, the fifth lens 150, and the sixth lens 160 may be used to diffuse light from the object side surface 142 of the fourth lens 140 to the image side surface 164 of the sixth lens 160 so that the light reaches each pixel of the image sensor 180.

[0086] 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.

[0087] In addition, when 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 among the first lens to the sixth lens, and the center thickness of the fifth lens 150 included in the second lens group G1 is the largest among the first lens to the sixth lens, the second lens group G2 can be used to diffuse light more uniformly to the periphery of the image sensor.

[0088] According to an embodiment of the present invention, a total track length (TTL) which is a distance from an object-side surface 112 of the first lens 110 to the image sensor 180 is 4 mm to 4.5 mm, a distance from an object-side surface 122 of the second lens 120 to the image sensor 180 is 3.6424 mm, a distance from an object-side surface 132 of the third lens 130 to the image sensor 180 is 3.3554 mm, a distance from an object-side surface 142 of the fourth lens 140 to the image sensor 180 is 2.6227 mm, a distance from an object-side surface 152 of the fifth lens 150 to the image sensor 180 is 2.0716 mm, and a distance from an object-side surface 162 of the sixth lens 160 to the image sensor 180 is 1.0032 mm. In addition, a back focal length (BFL) which is a distance from an image-side surface 164 of the sixth lens 160 to the image sensor 180 is 0.6 mm or more. The diagonal length of the image sensor 180 (2*H imageD ) is 6.538mm. From the perspective of those skilled in the art, when considering assembly performance, BFL should be implemented as 0.6mm or larger. For example, in the case where a camera device has an autofocus function, BFL should be implemented as 0.7mm or larger for assembly of the optical system and the image sensor, and when the optical system includes a circular asymmetric lens, BFL should be implemented as 0.7mm or larger. 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.

[0089] 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 mean the diameter of an effective area of ​​an object side surface or an image side surface on which light is incident.

[0090] The distances on the optical axis between the lenses included in the first lens group G1, for example, the distance on the optical axis between the image-side surface 114 of the first lens 110 and the object-side surface 122 of the second lens 120 (0.262 mm) and the distance on the optical axis between the image-side surface 124 of the second lens 120 and the object-side surface 132 of the third lens 130 (0.057 mm) are smaller than the distance on the optical axis between the first lens group G1 and the second lens group G2 (i.e., the distance on the optical axis between the image-side surface 134 of the third lens 130 and the object-side surface 142 of the fourth lens 140), and smaller than the distances on the optical axis between the lenses included in the second lens group G2, for example, smaller than the distance on the optical axis between the image-side surface 144 of the fourth lens 140 and the object-side surface 152 of the fifth lens 150 and the distance on the optical axis between the image-side surface 154 of the fifth lens 150 and the object-side surface 162 of the sixth lens.

[0091] In this case, 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 (ED L4S1 ), 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 ).

[0092] 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.

[0093] 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.

[0094] 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 is design data showing the sag 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, and Figure 7 is design data showing the tilt 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 mean 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, respectively, and L1S1, L1S2, L2S1, L2S2, L3S1, L3S2, L4S1, L4S2, L5S1, L5S2, L6S1 and L6S2 respectively represent 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.

[0095] Reference Figure 5, the distance between the image-side surface 114 of the first lens 110 and the object-side surface 122 of the second lens 120 may be uniformly maintained from the optical axis to the end of the image-side surface 114 of the first lens 110. Here, the end of the surface of the lens may mean the end of the effective area of ​​the surface of the lens. Here, the optical axis may mean a point where the distance along the Y direction is 0. Here, in the case where the ratio of the maximum distance to the minimum distance between the relative surfaces of different lenses from the optical axis to the end of the surface of the lens is 3 times or less, it can be interpreted that: the distance between the relative surfaces of different lenses is uniformly maintained.

[0096] 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.

[0097] 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 ) between the image side surface 124 of the second lens 120 and the object side surface 132 of the third lens 130 from the optical axis to the end of the image side surface 124 of the second lens 120 is max ) and the minimum distance (T23 min ) can be 3 times or less.

[0098] Similarly, 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 from the optical axis to the end of the image-side surface 134 of the third lens 130. That is, 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 from the optical axis to the end of the image-side surface 134 of the third lens 130 is 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.

[0099] At the same time, refer to Figure 6 and Figure 7According 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 refer to a point at which a trend of a sag value changes. The sag value means a distance on the optical axis between any point on the lens surface and a point on the optical axis. The point at which a trend of a sag value changes may be a point at which the sag value increases and then decreases, or may be a point at which the sag value decreases and then increases. The critical point may refer to a point at which a tilt angle becomes 0. The tilt angle may be defined as an angle formed by a normal line of a tangent line of a lens surface and the optical axis.

[0100] 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 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 a lens surface including a critical point can be more effectively refracted than light passing through a lens surface that does not include a 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 in the first lens group G1 is designed to be smaller than the minimum effective diameter in 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 lens to the third lens, the light can uniformly reach the peripheral pixels of the image sensor 180, and the performance of the optical system 100 can be improved.

[0101] 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 at a vertical distance of 0.5 mm to 0.6 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 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 55% to 67%. 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 a position set based on a direction perpendicular to the optical axis.

[0102] 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 at a distance of 1 mm to 1.1 mm from the optical axis. For example, in a case where 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 90% to 100%.

[0103] Therefore, in the case where at least one of the six surfaces of the first lens 110, the second lens 120, and the third lens 130, specifically, the image-side surface 134 of the third lens 130 includes a critical point, light output from the first lens group G1 can be uniformly dispersed. In the case where the image-side surface 134 of the third lens 130 includes a critical point, even in the case where the third lens 130 is tilted, since the optical performance of the optical system 100 is not significantly affected, the assembly performance of the optical system 100 can be improved. Specifically, in the case where 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, and in the case where the critical point of the image-side surface 134 of the third lens 130 is located at a position of about 90% to 100%, light near the edge of the image-side surface 134 of the third lens 130 can be more uniformly diffused.

[0104] In addition, according to an embodiment of the present invention, at least three 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. Light is more effectively refracted near the critical point. In the case where the critical point exists on the periphery of the image-side surface 164 of the sixth lens 160, which is the lens surface closest to the image sensor 180, it may be easy for the light effectively refracted at the image-side surface 164 of the sixth lens 160 to uniformly reach the peripheral pixels of the image sensor 180. 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 may 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 assembly of the first to fifth lenses of the optical system 100 is not affected and thus optical performance is not significantly affected, assembly performance of the optical system 100 can be improved. In the case where a critical point exists on the image-side surface or the object-side surface of the first lens 110, which is a 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 sixth lens, which are remaining lenses, performance of the optical system is significantly reduced.

[0105] 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.

[0106] According to an embodiment of the present invention, both the object side surface 142 and the image side surface 144 of the fourth lens 140 may have a critical point. The critical point of the object side surface 142 of the fourth lens 140 may be a point at a 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 64% to 72%. The critical point of the image side surface 144 of the fourth lens 140 may be a point at a 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 image side surface 144 of the fourth lens 140 is 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 56% to 64%. According to an embodiment of the present invention, the distance from the optical axis to the critical point of the object-side surface 142 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 most preferably 0.99 to 1.01 times, of the distance from the optical axis to the critical point of the image-side surface 144 of the fourth lens 140. Here, the distance from the optical axis to the critical point may mean a distance perpendicular to the optical axis.

[0107] 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 at a 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 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 53% to 60%. According to an embodiment of the present invention, the distance from the optical axis to the critical point of the object side surface 142 of the fourth lens 140 may be 0.9 times to 1.1 times the distance from the optical axis to the critical point of the object side surface 152 of the fifth lens 150, preferably 0.95 times to 1.05 times, more preferably 0.97 times to 1.3 times, and more preferably 0.99 times to 1.01 times. When the critical point of the object-side surface 142 of the fourth lens 140, the critical point of the image-side surface 144 of the fourth lens 140, and the critical point of the object-side surface 152 of the fifth lens 150 meet the above conditions, the second lens group G2 can be used to disperse the light that passes through the first lens group G1 and is incident on the second lens group G2 to increase the amount of light reaching the periphery of the image sensor 180.

[0108] According to an embodiment of the present invention, the critical point of the object side surface 142 of the fourth lens 140, the critical point of the image side surface 144 of the fourth lens 140, and the critical point of the object side surface 152 of the fifth lens 150 are sequentially positioned, there is no critical point on the image side surface 154 of the fifth lens 150 and the object side surface 162 of the sixth lens 160, and there is a critical point on the image side surface 164 of the sixth lens 160. The critical point of the image side surface 164 of the sixth lens 160 may be a point at a distance of 0.6 mm to 0.7 mm from the optical axis. For example, in the case where the optical axis is the starting point and the end of the image side surface 164 of the sixth lens 160 is 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 24% to 29%.

[0109] Meanwhile, according to an embodiment of the present invention, a distance T45 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 from the optical axis OA to the end of the image-side surface 144 of the fourth lens 140. That is, from the optical axis to the end of the image-side surface 144 of the fourth lens 140, 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 max ) and minimum distance (T45 min ) can be 3 times or less, preferably 2 times or less.

[0110] In contrast, the distance T56 between the image side surface 154 of the fifth lens 150 and the object side surface 162 of the sixth lens 160 may change rapidly from the optical axis to the end of the image side surface 154 of the fifth lens 150. According to an embodiment of the present invention, the distance T56 between the image side surface 154 of the fifth lens 150 and the object side surface 162 of the sixth lens 160 may decrease as the distance from the optical axis becomes farther and farther until the end of the image side surface 154 of the fifth lens 150. As described above, the end of the lens surface may refer to the end of the effective diameter. According to an embodiment of the present invention, the maximum distance (T56) between the image side surface 154 of the fifth lens 150 and the object side surface 162 of the sixth lens 160 max ) and the minimum distance (T56 min ) may be more than 3 times, preferably 4 times or more, more preferably 5 times or more, and more preferably 10 times or more. According to an embodiment of the present invention, there is a minimum distance (T56 ) between the image-side surface 154 of the fifth lens 150 and the object-side surface 162 of the sixth lens 160. min) may be the end of the image side surface 154 of the fifth lens 150, that is, the end of the effective diameter of the image side surface 154 of the fifth lens 150, or a point within a specific distance from the end of the effective diameter, where the specific distance may be ±0.4 mm.

[0111] To this end, an aspect in which the tilt angle of the image-side surface 154 of the fifth lens 150 varies and an aspect in which the tilt angle of the object-side surface 162 of the sixth lens 160 varies may be different.

[0112] As described above, according to an embodiment of the present invention, all of the critical points of the object-side surface 142 of the fourth lens 140, the critical points of the image-side surface 144 of the fourth lens 140, and the critical points of the object-side surface 152 of the fifth lens 150 may be set to have similar vertical distances from the optical axis. That is, the distance from the optical axis to the critical point of the object-side surface 142 of the fourth lens 140 may be 0.9 times to 1.1 times, preferably 0.95 times to 1.05 times, more preferably 0.97 times to 1.3 times, and most preferably 0.99 times to 1.01 times the distance from the optical axis to the critical point of the image-side surface 144 of the fourth lens 140, and may be 0.9 times to 1.1 times, preferably 0.95 times to 1.05 times, more preferably 0.97 times to 1.3 times, and most preferably 0.99 times to 1.01 times the distance from the optical axis to the critical point of the object-side surface 152 of the fifth lens 150.

[0113] According to an embodiment of the present invention, within a vertical distance between at least one of a critical point of the object-side surface 142 of the fourth lens 140, a critical point of the image-side surface 144 of the fourth lens 140, and a critical point of the object-side surface 152 of the fifth lens 150 and the optical axis, for example, a tilt angle on the object-side surface 162 of the sixth lens 160 may change faster than a tilt angle on the image-side surface 154 of the fifth lens 150. For example, up to a point having a vertical distance between the optical axis and the critical point of the object-side surface 152 of the fifth lens 150, a maximum tilt angle with respect to the object-side surface 162 of the sixth lens 160 may be greater than a maximum tilt angle with respect to the image-side surface 154 of the fifth lens 150. For example, in the case where the inclination angle on the optical axis of the image-side surface 154 of the fifth lens 150 is 0 and the inclination angle on the optical axis of the object-side surface 162 of the sixth lens 160 is zero, the maximum inclination angle with respect to the object-side surface 162 of the sixth lens 160 may be 2 times or more, and preferably 2.5 times or more, to a point having a vertical distance between the optical axis and a critical point of the object-side surface 152 of the fifth lens 150. For example, the inclination angle with respect to the object-side surface 162 of the sixth lens 160 may have a range of 0 to 35 degrees, and the inclination angle with respect to the image-side surface 154 of the fifth lens 150 may have a range of 0 to 17.5 degrees, to a point having a vertical distance between the optical axis and a critical point of the object-side surface 152 of the fifth lens 150. In the case where the image-side surface 154 of the fifth lens 150 and the object-side surface 162 of the sixth lens 160 have a tilt angle, light refracted by the object-side surface 142 and the image-side surface 144 of the fourth lens 140 and the object-side surface 152 of the fifth lens 150 may be uniformly dispersed on the image-side surface 154 of the fifth lens 150 and the object-side surface 162 of 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 may be improved while satisfying optical performance.

[0114] According to an embodiment of the present invention, the image-side surface 154 of the fifth lens 150 is convex toward the image side, the object-side surface 162 of the sixth lens 160 is concave toward the object side, and the absolute value of the radius of curvature of the image-side surface 154 of the fifth lens 150 may be greater than the absolute value of the radius of curvature of the object-side surface 162 of the sixth lens 160. Preferably, the absolute value of the radius of curvature of the image-side surface 154 of the fifth lens 150 may be 2 times or more the absolute value of the radius of curvature of the object-side surface 162 of the sixth lens 160. More preferably, the absolute value of the radius of curvature of the image-side surface 154 of the fifth lens 150 may be 2 times to 3 times the absolute value of the radius of curvature of the object-side surface 162 of the sixth lens 160.

[0115] When the image side surface 154 of the fifth lens 150 and the object side surface 162 of the sixth lens 160 are designed to satisfy the above conditions, light incident on the fifth lens 150 can be dispersed by the fifth lens 150 and the sixth lens 160, and the amount of light reaching the periphery of the image sensor 180 can be increased.

[0116] 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 a 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 3.5950 mm, an F number of 2 or less, a FOV of 84 degrees or more in the diagonal direction, and an RI of 25% or more in 1 field.

[0117] [Formula 1]

[0118] 0.9≤ED L1S1 / EPD≤1.1

[0119] Here, ED L1S1 is 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.

[0120] [Formula 2]

[0121] ED L1S1 <2H imageD

[0122] Here, H imageD is a value half the diagonal length of the pixel area of ​​the image sensor 170. 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.

[0123] [Formula 3]

[0124] 1.62mm≤ED L1S1 ≤1.98mm

[0125] Therefore, the head size of the optical system 100 can be minimized.

[0126] [Formula 4]

[0127] 1.62mm≤EPD≤1.98mm

[0128] Therefore, the head size of the optical system 100 can be minimized.

[0129] [Formula 5]

[0130] 2≤CT5 / CT4

[0131] Here, CT5 is the center thickness of the fifth lens 150, and CT4 is the center thickness of the fourth lens 140. Therefore, assembling and aligning of the optical system are easy.

[0132] [Formula 6]

[0133] T23 <T12<T45<T34<T56

[0134] Here, T23 is the distance between the second lens 120 and the third lens 130, T12 is the distance between the first lens 110 and the second lens 120, T45 is the distance between the fourth lens 140 and the fifth lens 150, T34 is the distance between the third lens 130 and the fourth lens 140, and T56 is the distance between the fifth lens 150 and the sixth lens 160. Therefore, assembly and alignment of the optical system are easy, and even in the case where 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.

[0135] [Formula 7]

[0136] 1.6≤T56 / T12≤2.6

[0137] Therefore, the assembly and alignment of the optical system are easy, and even if 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. Preferably, T56 / T12 may be 1.9 or more and 2.3 or less.

[0138] [Formula 8]

[0139] 8≤T56 / T23≤12

[0140] Therefore, the assembly and alignment of the optical system are easy, and even if 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. Preferably, T56 / T23 may be 9 or more and 11 or less.

[0141] [Formula 9]

[0142] 1.5≤T56 / T34≤2.5

[0143] Therefore, assembly and alignment of the optical system are easy, and light incident on the second lens group G2 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.

[0144] [Formula 10]

[0145] 1.5≤T56 / T45≤2.5

[0146] Therefore, assembly and alignment of the optical system are easy, and light incident on the second lens group G2 can pass through the second lens group G2 and uniformly reach each pixel of the image sensor 180 without distortion. Preferably, T56 / T45 may be 1.6 or more and 2 or less.

[0147] [Formula 11]

[0148] 2≤|P1| / |P2|

[0149] Therefore, the first lens 110 collects light incident on the optical system 100, and the second lens 120 may correct chromatic aberration.

[0150] [Formula 12]

[0151] 1.5≤CT1 / CT2

[0152] Therefore, the first lens 110 collects light incident on the optical system 100, and the second lens 120 may correct chromatic aberration.

[0153] [Formula 13]

[0154] 4mm≤TTL≤4.5mm

[0155] 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.

[0156] [Formula 14]

[0157] 0.6mm≤BFL

[0158] Here, the 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.

[0159] [Formula 15]

[0160] 1.11≤TTL / EFL≤1.26

[0161] Here, EFL is the effective focal length. Therefore, high-resolution images can be acquired even in a narrow space.

[0162] [Formula 16]

[0163] 1.22≤TTL / H imageD ≤1.38

[0164] Therefore, high-resolution images can be acquired even in a narrow space.

[0165] [Formula 17]

[0166] 2.2≤TTL / EPD≤2.5

[0167] Therefore, the head size of the optical system 100 and the overall size of the camera apparatus can be miniaturized.

[0168] [Formula 18]

[0169] ED G1_max <ED G2_min

[0170] 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.

[0171] [Formula 19]

[0172] ED L4S1 <ED L4S2 <ED L5S1 <ED L5S2 <ED L6S1 <ED L6S2

[0173] 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 L5S1 is 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 the 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.

[0174] [Formula 20]

[0175] ED G1_max / ED L6S2 ≤0.7

[0176] 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.

[0177] [Formula 21]

[0178] T12 max / T12 min ≤3

[0179] 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 minis 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.

[0180] [Formula 22]

[0181] T23 max / T23 min ≤3

[0182] 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 min is 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.

[0183] [Formula 23]

[0184] T34 max / T34 min ≤3

[0185] 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, 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.

[0186] [Equation 24]

[0187] 0.9≤T_CP L4S1 / T_CP L4S2 ≤1.1

[0188] Here, T_CP L4S1 is the distance from the optical axis to the critical point of the object-side surface 142 of the fourth lens 140, and T_CP L4S2is the distance from the optical axis to the critical point of the image side surface 144 of the fourth lens 40. Therefore, 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, 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 object side surface 142 of the fourth lens 140 is effectively refracted again at the critical point of the image side surface 144 of the fourth lens 140, the effective refraction effect of the light can be maximized. Preferably, T_CP L4S1 / T_CP L4S2 It may be 0.95 or more and 1.05 or less.

[0189] [Formula 25]

[0190] 0.9≤T_CP L4S1 / T_CP L5S1 ≤1.1

[0191] Here, T_CP L5S1 is 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 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 object-side surface 142 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 L4S1 / T_CP L5S1 It may be 0.95 or more and 1.05 or less.

[0192] [Equation 26]

[0193] T45 max / T45 min ≤3

[0194] 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, 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, assembling and alignment of the optical system are easy.

[0195] [Formula 27]

[0196] 3 <T56 max / T56 min

[0197] Here, T56max is the maximum distance between the image-side surface 154 of the fifth lens 150 and the object-side surface 162 of the sixth lens 160, T56 min is the minimum distance between the image-side surface 154 of the fifth lens 150 and the object-side surface 162 of the sixth lens 160. Therefore, light incident on the fifth lens 150 can be dispersed by the fifth lens 150 and the sixth lens 160, and the amount of light reaching the periphery of the image sensor 180 can be increased. Preferably, T56 max / T56 min Can be more than 4.

[0198] [Equation 28]

[0199] S L5S2_max <SA L6S1_max

[0200] Here, SA L5S2_max may be the maximum tilt angle of the image-side surface 154 of the fifth lens 150, and SA L6S1_max may be the maximum tilt angle of the object-side surface 162 of the sixth lens 160. At a vertical distance from the optical axis at T_CP L1S1 、T_CP L4S2 or T_CP L5S1 Therefore, the light incident on the fifth lens 150 can be dispersed by the fifth lens 150 and the sixth lens 160, the amount of light reaching the periphery of the image sensor 180 can be increased, and the manufacturing performance can be improved while satisfying the optical performance.

[0201] [Formula 29]

[0202] 2≤SA L6S1_max / SA L5S2_max

[0203] Here, at a vertical distance from the optical axis at T_CP L4S1 、T_CP L4S2 or T_CP L5S1 Therefore, the light incident on the fifth lens 150 can be dispersed by the fifth lens 150 and the sixth lens 160, the amount of light reaching the periphery of the image sensor 180 can be increased, and the manufacturing performance can be improved while satisfying the optical performance.

[0204] [Formula 30]

[0205] 0 degrees ≤ SA L6S1 ≤35 degrees

[0206] Here, SA L6S1is the inclination angle of the object-side surface 162 of the sixth lens 160, and is at a vertical distance from the optical axis at T_CP L4S1 、T_CP L4S2 or T_CP L5S1 Therefore, the light incident on the fifth lens 150 can be dispersed by the fifth lens 150 and the sixth lens 160, the amount of light reaching the periphery of the image sensor 180 can be increased, and the manufacturing performance can be improved while satisfying the optical performance.

[0207] [Equation 31]

[0208] 0 degrees ≤ SA L5S1 ≤17.5 degrees

[0209] Here, SA L5S2 is the inclination angle of the image side surface 154 of the fifth lens 150, and is at a vertical distance from the optical axis at T_CP L4S1 、T_CP L4S2 or T_CP L5S1 Therefore, the light incident on the fifth lens 150 can be dispersed by the fifth lens 150 and the sixth lens 160, the amount of light reaching the periphery of the image sensor 180 can be increased, and the manufacturing performance can be improved while satisfying the optical performance.

[0210] [Formula 32]

[0211] |R L6S1 |≤|R L5S2 |

[0212] Here, R L6S1 is the radius of curvature of the object-side surface 162 of the sixth lens 160, R L5S2 is the radius of curvature of the image-side surface 154 of the fifth lens 150. Therefore, light incident on the fifth lens 150 may be effectively dispersed by the fifth lens 150 and the sixth lens 160.

[0213] [Formula 33]

[0214] 2≤|R L5S2 | / |R L6S1 |

[0215] Therefore, light incident on the fifth lens 150 may be effectively dispersed by the fifth lens 150 and the sixth lens 160 .

[0216] 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 8shows 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 one embodiment of the present invention is shown.

[0217] [Table 5]

[0218]

[0219]

[0220] 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 8 degrees or more, for example, in the range of 8 degrees to 37 degrees, the amount of light at the periphery (1 field) of the image sensor is 25% or more, and the amount of light at the central part (0 field) of the image sensor is 100%. Figure 8 , the sharpness of the image according to the pixel at the spatial frequency can be obtained, which can be obtained from the optical system according to one embodiment of the present invention, and refer to Fig. 9 , the distortion of the image can be obtained, which can be obtained from an optical system according to an embodiment of the present invention.

[0221] Fig.10 is a view showing a portion of a mobile terminal to which a camera device according to one embodiment of the present invention is applied.

[0222] 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.

[0223] 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.

[0224] 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.

[0225] The mobile terminal may be a smart phone, a tablet PC, a laptop computer, a PDA, or the like.

[0226] 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 of 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 as defined by the appended claims.

[0227] [reference numerals]

[0228] 100: Optical system

[0229] 110: First lens

[0230] 120: Second lens

[0231] 130: The third lens

[0232] 140: The fourth lens

[0233] 150: Fifth lens

[0234] 160: Sixth lens

[0235] 170: Filter

[0236] 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 order 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, and The diameter of the first lens is 90% to 110% of an entrance pupil diameter (EPD).

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

3. The optical system of claim 1, wherein: The image side surface of the fifth lens is convex toward the image side; The object-side surface of the sixth lens is concave toward the object side; and From the optical axis to a certain distance, the distance between the image-side surface of the fifth lens and the object-side surface of the sixth lens decreases as being away from the optical axis.

4. The optical system of claim 1, wherein: The image side surface of the fifth lens is convex toward the image side; The object-side surface of the sixth lens is concave toward the object side; and A maximum tilt angle with respect to an object-side surface of the sixth lens is greater than a maximum tilt angle with respect to an image-side surface of the fifth lens to a certain distance from the optical axis.

5. The optical system according to claim 4, wherein: A ratio of an absolute value of a radius of curvature of an object-side surface of the sixth lens to an absolute value of a radius of curvature of an image-side surface of the fifth lens is 2 to 3.

6. The optical system according to claim 4, wherein: At least one of the object-side surface of the second lens, the image-side surface of the third lens, the object-side surface of the fourth lens, the image-side surface of the fourth lens, the object-side surface of the fifth lens, and the image-side surface of the sixth lens includes a critical point.

7. The optical system according to claim 6, wherein: A vertical distance from the optical axis to a critical point of the object side surface of the fourth lens is 0.9 to 1.1 times a vertical distance from the optical axis to a critical point of the image side surface of the fourth lens, and a vertical distance from the optical axis to a critical point of the object side surface of the fourth lens is 0.9 to 1.1 times a vertical distance from the optical axis to a critical point of the object side surface of the fifth lens.

8. The optical system according to claim 7, wherein: The specific distance is a perpendicular distance between at least one of a critical point of an object-side surface of the fourth lens, a critical point of an image-side surface of the fourth lens, and a critical point of an object-side surface of the fifth lens and the optical axis.

9. The optical system according to claim 1, wherein: The F value is 2 or less, the field of view (FOV) is 84 degrees or more, and the relative illumination (RI) is 25% or more.

10. 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, The first lens has the smallest diameter among the first to sixth lenses, The object-side surface of the fourth lens, the image-side surface of the fourth lens, and the object-side surface of the fifth lens all include a critical point, The image side surface of the fifth lens is convex toward the image side, An object-side surface of the sixth lens is concave toward the object side, and An absolute value of a radius of curvature of an image-side surface of the fifth lens is greater than an absolute value of a radius of curvature of an object-side surface of the sixth lens.

Images