Optical imaging system

Abstract

The present invention provides an optical imaging system, comprising: a first lens having a refractive power, a second lens having a refractive power, a third lens having a refractive power, a fourth lens having a refractive power, and a fifth lens having a refractive power. Here, the first lens, the third lens, and the fifth lens may all have a refractive index of about 1.6 or greater, and the full field angle of the optical imaging system may be about 120° or greater.

Description

[0001] This application claims priority to and the benefit of Korean Patent Application No. 10-2018-0008289 filed on January 23, 2018, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety for all purposes by reference. Technical Field

[0002] The following description relates to an optical imaging system, for example, an optical imaging system including five or more lenses. Background Art

[0003] A compact camera module may be installed in a mobile communication terminal. For example, the compact camera module may be installed in a thin device such as a mobile phone. A compact camera module such as this includes an optical imaging system including a small number of lenses so that it may be thin. For example, the optical imaging system of the compact camera module may include four or fewer lenses. However, it may be difficult to achieve a low F number and a wide field angle in the optical imaging system. Summary of the invention

[0004] This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

[0005] In one general aspect, an optical imaging system includes: a first lens, a second lens, a third lens, a fourth lens, and a fifth lens arranged sequentially from an object side, wherein the first lens, the third lens, and the fifth lens each have a refractive index of 1.6 or greater, and a field of view of the optical imaging system is 100° or greater.

[0006] The object-side surface of the first lens may be convex.

[0007] The object-side surface of the second lens may be convex.

[0008] An object-side surface of the third lens may be convex.

[0009] An object-side surface of the fourth lens may be convex.

[0010] An object-side surface of the fifth lens may be convex.

[0011] The optical imaging system may have an F-number less than 2.3.

[0012] In another general aspect, an optical imaging system includes: a first lens, a second lens, a third lens, a fourth lens and a fifth lens arranged sequentially from an object side, wherein the first lens, the third lens and the fifth lens each have a refractive index of 1.6 or greater, and an object-side surface of the fourth lens is convex.

[0013] One or more of the refractive indices of the first lens, the third lens, and the fifth lens may be 1.66 or greater.

[0014] The optical imaging system may have an F-number less than about 2.3.

[0015] The optical imaging system may satisfy TTL / ImgHT<2.0, wherein TTL is the distance from the object surface of the first lens to the imaging plane of the optical imaging system along the optical axis of the lens, and ImgHT is half of the diagonal length of the imaging plane.

[0016] The optical imaging system may satisfy f≤1.76 mm, wherein f is the total focal length of the optical imaging system.

[0017] The optical imaging system may have a field of view of 120° or greater.

[0018] The optical imaging system may satisfy 2.86≤CT4 / ET4, wherein CT4 is the thickness of the optical axis portion of the fourth lens, and ET4 is the minimum thickness of the edge portion of the fourth lens.

[0019] The optical imaging system may satisfy 0.51≤CT5 / sag5, wherein CT5 is the thickness of the optical axis portion of the fifth lens, and sag5 is the arc height SAG at the edge of the image-side surface of the fifth lens.

[0020] The optical imaging system may satisfy |f1 / f|<4.0, wherein f is the total focal length of the optical imaging system, and f1 is the focal length of the first lens.

[0021] An electronic device may include an optical imaging system, which includes: a first lens, a second lens, a third lens, a fourth lens, and a fifth lens arranged sequentially from an object side, wherein the first lens, the third lens, and the fifth lens each have a refractive index of approximately 1.6 or greater, and the field of view of the optical imaging system is approximately 100° or greater.

[0022] The electronic device may be a mobile communication terminal.

[0023] The mobile communication terminal may have an F number less than about 2.3.

[0024] The mobile communication terminal may have a viewing angle of about 100° or more, for example, may have a viewing angle of about 100° to about 120°.

[0025] In various aspects, the optical imaging system can have a low F-number of about 2.3 or less, or a low F-number of about 2.0 to about 2.3, and a field of view of about 100° or more, or a field of view of about 100° to about 120°.

[0026] Other features and aspects will be apparent from the following detailed description and accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a diagram showing an optical imaging system according to a first embodiment.

[0028] Figure 2 It shows that Figure 1 Graph of aberration curves of the optical imaging system shown.

[0029] Figure 3 is a diagram showing an optical imaging system according to a second embodiment.

[0030] Figure 4 It shows that Figure 3 Graph of aberration curves of the optical imaging system shown.

[0031] Figure 5 is a diagram showing an optical imaging system according to a third embodiment.

[0032] Figure 6 It shows that Figure 5 Graph of aberration curves of the optical imaging system shown.

[0033] Figure 7 is a diagram showing an optical imaging system according to a fourth embodiment.

[0034] Figure 8 It shows that Figure 7 Graph of aberration curves of the optical imaging system shown.

[0035] Throughout the drawings and detailed description, the same reference numerals refer to the same elements. For clarity, illustration, and convenience, the drawings may not be drawn to scale, and the relative sizes, proportions, and depictions of the elements in the drawings may be exaggerated. DETAILED DESCRIPTION

[0036] The following specific embodiments are provided to help the reader obtain a comprehensive understanding of the methods, devices and / or systems described herein. However, after understanding the disclosure of the present application, various changes, modifications and equivalents of the methods, devices and / or systems described herein will be apparent. For example, the order of operations described herein is merely an example and is not limited to those order of operations set forth herein, but in addition to the operations that must occur in a particular order, changes that will be apparent after understanding the disclosure of the present application may be made. In addition, in order to improve clarity and brevity, the description of features known in the art may be omitted.

[0037] The features described herein may be implemented in different forms and should not be interpreted as being limited to the examples described herein. Rather, the examples described herein are provided only to illustrate some of the many possible ways of implementing the methods, devices and / or systems described herein that will be apparent after understanding the disclosure of the present application.

[0038] Throughout the specification, when an element (such as a layer, a region, or a substrate) is described as being “on”, “connected to”, or “coupled to” another element, the element may be directly “on”, “connected to”, or “coupled to” the other element, or other elements interposed therebetween may exist. In contrast, when an element is described as being “directly on”, “directly connected to”, or “directly coupled to” another element, other elements interposed therebetween may not exist.

[0039] As used herein, the term "and / or" includes any one of the associated listed items and any combination of any two or more.

[0040] Although terms such as "first", "second", and "third" may be used herein to describe various members, components, regions, layers, or portions, these members, components, regions, layers, or portions should not be limited by these terms. Rather, these terms are only used to distinguish one member, component, region, layer, or portion from another member, component, region, layer, or portion. Therefore, without departing from the teachings of the examples described herein, the first member, first component, first region, first layer, or first portion referred to in the examples described herein may be referred to as the second member, second component, second region, second layer, or second portion.

[0041] For ease of description, spatially relative terms (such as "above", "above", "below", and "below") may be used herein to describe the relationship of one element to another element shown in the drawings. Such spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation depicted in the drawings. For example, if the device in the drawings is turned over, an element described as being "above" or "above" relative to another element will subsequently be "below" or "below" relative to the other element. Therefore, the term "above" may include both "above" and "below" orientations depending on the spatial orientation of the device. The device may be positioned in other ways (e.g., rotated 90 degrees or in other orientations), and the spatially relative terms used herein may be interpreted accordingly.

[0042] The terms used herein are only for describing various examples and are not intended to limit the present disclosure. Unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. The terms "comprise", "include" and "have" list the existence of the stated features, quantities, operations, components, elements and / or their combinations, but do not exclude the existence or addition of one or more other features, quantities, operations, components, elements and / or their combinations.

[0043] Variations in the shapes shown in the drawings may occur due to manufacturing techniques and / or tolerances. Therefore, the examples described herein are not limited to the specific shapes shown in the drawings but include variations in shapes that occur during manufacturing.

[0044] The features of the examples described herein may be combined in various ways as will be apparent after understanding the disclosure of the present application. In addition, although the examples described herein have various configurations, other configurations as will be apparent after understanding the disclosure of the present application are feasible.

[0045] In addition, in this specification, the first lens refers to the lens closest to the object (or subject), and the fifth lens refers to the lens closest to the imaging plane (or image sensor). In addition, the radius of curvature and thickness of the lens, TTL (the distance from the object surface of the first lens to the imaging plane of the optical imaging system along the optical axis of the lens), ImgHT (image height) and focal length are all expressed in millimeters (mm). In addition, the thickness of the lens, the spacing between lenses and TTL are the distances along the optical axis of the lens. In addition, in the description of the shape of the lens, the meaning of one surface of the lens being convex is that the optical axis portion of the corresponding surface is convex, and the meaning of one surface of the lens being concave is that the optical axis portion of the corresponding surface is concave. Therefore, although one surface of the lens can be described as convex, the edge portion of the one surface of the lens may be concave. Similarly, although one surface of the lens can be described as concave, the edge portion of the one surface of the lens may be convex.

[0046] The optical imaging system may include five lenses arranged sequentially from the object side toward the imaging surface. For example, the optical imaging system may include a first lens, a second lens, a third lens, a fourth lens, and a fifth lens arranged sequentially. The first lens to the fifth lens may be arranged with a predetermined interval therebetween. For example, a predetermined interval may be formed between the image-side surface of the first lens and the object-side surface of the second lens. It should be noted here that the use of the term "may" with respect to examples or embodiments (for example, with respect to what an example or embodiment may include or implement) means that there is at least one example or embodiment that includes or implements such a feature, and all examples and embodiments are not limited thereto.

[0047] The first lens may have a refractive power. For example, the first lens may have a negative refractive power.

[0048] One surface of the first lens may be convex. For example, the object-side surface of the first lens may be convex. The first lens may have an aspherical surface. For example, both surfaces of the first lens may be aspherical. The first lens may be formed using a material having high light transmittance and good processability. For example, the first lens may be formed using plastic. However, the material of the first lens is not limited to plastic. For example, the first lens may be formed using glass.

[0049] The first lens may have a predetermined refractive index. For example, the refractive index of the first lens may be about 1.6 or greater, preferably, about 1.6 to about 1.7. The first lens may have a predetermined Abbe number. For example, the Abbe number of the first lens may be less than about 22, preferably, between about 20 and 22.

[0050] The second lens may have refractive power. For example, the second lens may have positive refractive power.

[0051] One surface of the second lens may be convex. For example, the object-side surface of the second lens may be convex. The second lens may include an aspherical surface. For example, both surfaces of the second lens may be aspherical. The second lens may be formed using a material having high light transmittance and good processability. For example, the second lens may be formed using plastic. However, the material of the second lens is not limited to plastic. For example, the second lens may also be formed using glass.

[0052] The refractive index of the second lens may be less than the refractive index of the other lenses. For example, the refractive index of the second lens may be less than 1.6, preferably, between about 1.5 and about 1.6. The second lens may have a predetermined Abbe number. For example, the Abbe number of the second lens may be about 50 or more, preferably, between about 50 and 57.

[0053] The third lens may have refractive power. For example, the third lens may have negative refractive power.

[0054] One surface of the third lens may be convex. For example, the object-side surface of the third lens may be convex. The third lens may have an aspherical surface. For example, both surfaces of the third lens may be aspherical. The third lens may have an inflection point. For example, one or more inflection points may be formed on the object-side surface or the image-side surface of the third lens.

[0055] The third lens may be formed using a material having high light transmittance and good processability. For example, the third lens may be formed using plastic. However, the material of the third lens is not limited to plastic. For example, the third lens may be formed using glass.

[0056] The refractive index of the third lens may be substantially similar or substantially the same as the refractive index of the first lens. For example, the refractive index of the third lens may be about 1.6 or greater, preferably, between about 1.6 and about 1.7. The Abbe number of the third lens may be similar to the Abbe number of the first lens. For example, the Abbe number of the third lens may be less than about 22, preferably, between about 20 and about 22.

[0057] The fourth lens may have refractive power. For example, the fourth lens may have positive refractive power.

[0058] One surface of the fourth lens may be convex. For example, the object-side surface of the fourth lens may be convex. The fourth lens may include an aspherical surface. For example, both surfaces of the fourth lens may be aspherical. The fourth lens may be formed using a material having high light transmittance and good processability. For example, the fourth lens may be formed using plastic. However, the material of the fourth lens is not limited to plastic. For example, the fourth lens may be formed using glass.

[0059] The refractive index of the fourth lens may be substantially similar to or substantially the same as the refractive index of the second lens. For example, the refractive index of the fourth lens may be less than about 1.6, preferably, between about 1.5 and 1.6. The Abbe number of the fourth lens may be greater than the Abbe number of the fifth lens. For example, the Abbe number of the fourth lens may be about 50 or greater, preferably, between about 50 and 57.

[0060] The fifth lens may have refractive power. For example, the fifth lens may have negative refractive power.

[0061] One surface of the fifth lens may be convex. For example, the object-side surface of the fifth lens may be convex. The fifth lens may include an aspherical surface. For example, both surfaces of the fifth lens may be aspherical. The fifth lens may have an inflection point. For example, one or more inflection points may be formed on the object-side surface or the image-side surface of the fifth lens.

[0062] The fifth lens may be formed using a material having high light transmittance and good processability. For example, the fifth lens may be formed using plastic. However, the material of the fifth lens is not limited to plastic. For example, the fifth lens may be formed using glass.

[0063] The refractive index of the fifth lens may be substantially similar to or substantially the same as the refractive index of the first lens. For example, the refractive index of the fifth lens may be about 1.6 or greater, preferably, between about 1.6 and 1.7. The fifth lens may have a predetermined Abbe number. For example, the Abbe number of the fifth lens may be less than about 22, preferably, between about 20 and 22.

[0064] In an optical imaging system, the aspheric surface of each lens can be expressed by the following equation 1:

[0065] Formula 1

[0066]

[0067] Here, c is the inverse of the radius of curvature of the lens, k is the cone constant, r is the distance from a point on the aspherical surface of the lens to the optical axis in a direction perpendicular to the optical axis of the lens, A to H and J are aspherical constants, and Z (or sagitta SAG) is the distance between a point on the aspherical surface of the lens at a distance r from the optical axis and a tangent plane intersecting the vertex of the aspherical surface of the lens.

[0068] The optical imaging system may also include filters, image sensors and / or apertures.

[0069] The filter may be disposed between the rearmost lens and the image sensor. The filter may be configured to block light of infrared wavelengths. The image sensor may form an imaging surface. A stop may be provided to control the amount of light incident on the lens. The stop may be provided between the first lens and the second lens. However, the stop is not limited to being provided between the first lens and the second lens.

[0070] The optical imaging system may satisfy one or more of the following conditional expressions:

[0071] Conditional expression 1F number < 2.3

[0072] Conditional expression 2TTL / ImgHT<2.0

[0073] Conditional expression 3f≤1.76mm

[0074] Conditional Expression 4 100°≤FOV

[0075] Conditional expression 5 120°≤FOV

[0076] Conditional expression 6 2.86≤CT4 / ET4

[0077] Conditional Expressions 7-36 <V1-V2

[0078] Conditional expression 8V4-V5<36

[0079] Conditional expression 9 0.51≤CT5 / sag5

[0080] Conditional Expression 10 1.60 <Nd1

[0081] Conditional Expression 11 1.60 <Nd3

[0082] Conditional Expression 12 1.60 <Nd5

[0083] Conditional expression 13|f1 / f|<4.0

[0084] Conditional expression 14 4.0<|f3 / f|

[0085] Here, TTL is the distance from the object surface of the first lens to the imaging surface of the optical imaging system along the optical axis of the lens, ImgHT is half the diagonal length of the imaging surface, f is the total focal length of the optical imaging system, FOV is the full field angle of the optical imaging system, CT4 is the thickness of the optical axis portion of the fourth lens, ET4 is the minimum thickness of the edge portion of the fourth lens, CT5 is the thickness of the optical axis portion of the fifth lens, sag5 is the SAG (arc height) at the edge of the image surface of the fifth lens, Nd1 is the refractive index of the first lens, Nd3 is the refractive index of the third lens, Nd5 is the refractive index of the fifth lens, f1 is the focal length of the first lens, f3 is the focal length of the third lens, V1 is the Abbe number of the first lens, V2 is the Abbe number of the second lens, V4 is the Abbe number of the fourth lens, and V5 is the Abbe number of the fifth lens.

[0086] Next, an optical imaging system according to several embodiments will be described.

[0087] Will refer to Figure 1 An optical imaging system according to a first embodiment is described.

[0088] The first lens 110 may have a negative refractive power, and its object-side surface may be convex, and its image-side surface may be concave. The second lens 120 may have a positive refractive power, and its object-side surface may be convex, and its image-side surface may be convex. The third lens 130 may have a negative refractive power, and its object-side surface may be convex, and its image-side surface may be concave. In addition, an inflection point may be formed on the object-side surface and the image-side surface of the third lens 130. As an example, the object-side surface of the third lens 130 may be convex at its paraxial portion and concave at its edge portion, and the image-side surface of the third lens 130 may be concave at its paraxial portion and convex at its edge portion. The fourth lens 140 may have a positive refractive power, and its object-side surface may be convex, and its image-side surface may be convex. The fifth lens 150 may have a negative refractive power, and its object-side surface may be convex, and its image-side surface may be concave. In addition, an inflection point may be formed on the object-side surface and the image-side surface of the fifth lens 150. As an example, the object-side surface of the fifth lens 150 may be convex at a paraxial portion thereof and concave at an edge portion thereof, and the image-side surface of the fifth lens 150 may be concave at a paraxial portion thereof and convex at an edge portion thereof.

[0089] The optical imaging system 100 may include an image sensor 170 forming an imaging surface. The optical imaging system 100 may include an optical filter 160. The optical filter 160 may be disposed between the fifth lens 150 and the image sensor 170. The optical imaging system 100 may include a stop ST. The stop ST may be disposed between the first lens 110 and the second lens 120.

[0090] In the optical imaging system 100, the refractive indexes of the first lens 110, the third lens 130, and the fifth lens 150 may be greater than the refractive indexes of other lenses. Specifically, the first lens 110, the third lens 130, and the fifth lens 150 may have a refractive index of about 1.661, and the second lens 120 and the fourth lens 140 may have a refractive index of about 1.544, and the refractive indexes of the second lens 120 and the fourth lens 140 are less than the refractive indexes of the first lens 110, the third lens 130, and the fifth lens 150.

[0091] In the optical imaging system 100 , the third lens 130 may have a focal length having the largest absolute value. In an embodiment, the focal length of the third lens 130 may be about −21.40 mm, and the focal lengths of the other lenses may be greater than the focal length of the third lens 130 .

[0092] The optical imaging system according to the first embodiment may have the following features: Figure 2 Table 1 shows the characteristics of the lens of the optical imaging system according to the first embodiment, and Table 2 shows the aspherical surface characteristics of the optical imaging system according to the first embodiment.

[0093] Table 1

[0094]

[0095] Table 2

[0096] First embodiment S1 S2 S3 S4 S5 S6 S7 S8 S9 S10 Radius of curvature 1.827225 0.914142 3.910097 -1.781266 1.571183 1.358865 11.842302 -0.707278 1.188851 0.521628 K 0.000000 0.000000 -8.401287 2.972624 0.000000 -10.250335 99.000000 -0.809139 0.000000 -3.335920 A 0.227844 0.590747 -0.121427 -0.732900 -1.329561 -0.293090 0.338870 0.713044 -1.010705 -0.419523 B -0.117480 0.250121 1.263999 1.897575 1.583851 -0.872037 -0.966386 -1.652933 0.875290 0.382958 C 0.065547 -0.354051 -27.117707 -9.329856 -4.108482 3.597064 1.644401 3.111453 -1.815142 -0.252569 D 0.186975 11.152435 231.208787 31.252425 14.537892 -5.191226 -1.611421 -3.391064 3.289688 0.104104 E -0.315675 -14.942084 -1016.812218 -63.404808 -26.675815 3.300072 0.874709 1.948480 -3.781265 -0.026347 F 0.103098 0.079450 1720.364702 47.165852 17.388764 -0.766556 -0.200940 -0.430857 2.219282 0.003823 G 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 -0.515963 -0.000251 H 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 J 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000

[0097] Will refer to Figure 3 An optical imaging system according to a second embodiment is described.

[0098] The first lens 210 may have a negative refractive power, and its object-side surface may be convex, and its image-side surface may be concave. The second lens 220 may have a positive refractive power, and its object-side surface may be convex, and its image-side surface may be convex. The third lens 230 may have a negative refractive power, and its object-side surface may be convex, and its image-side surface may be concave. In addition, an inflection point may be formed on the object-side surface and the image-side surface of the third lens 230. As an example, the object-side surface of the third lens 230 may be convex at its paraxial portion and concave at its edge portion, and the image-side surface of the third lens 230 may be concave at its paraxial portion and convex at its edge portion. The fourth lens 240 may have a positive refractive power, and its object-side surface may be convex, and its image-side surface may be convex. The fifth lens 250 may have a negative refractive power, and its object-side surface may be convex, and its image-side surface may be concave. In addition, an inflection point may be formed on the object-side surface and the image-side surface of the fifth lens 250. As an example, the object-side surface of the fifth lens 250 may be convex at a paraxial portion thereof and concave at an edge portion thereof, and the image-side surface of the fifth lens 250 may be concave at a paraxial portion thereof and convex at an edge portion thereof.

[0099] The optical imaging system 200 may include an image sensor 270 forming an imaging surface. The optical imaging system 200 may include an optical filter 260. The optical filter 260 may be disposed between the fifth lens 250 and the image sensor 270. The optical imaging system 200 may include a stop ST. The stop ST may be disposed between the first lens 210 and the second lens 220.

[0100] In the optical imaging system 200, the refractive indexes of the first lens 210, the third lens 230, and the fifth lens 250 may be greater than the refractive indexes of other lenses. Specifically, the first lens 210, the third lens 230, and the fifth lens 250 may have a refractive index of about 1.661, and the second lens 220 and the fourth lens 240 may have a refractive index of about 1.544, and the refractive indexes of the second lens 220 and the fourth lens 240 are less than the refractive indexes of the first lens 210, the third lens 230, and the fifth lens 250.

[0101] In the optical imaging system 200 , the third lens 230 may have a focal length having the largest absolute value. In an embodiment, the focal length of the third lens 230 may be about −35.10 mm, and the focal lengths of the other lenses may be greater than the focal length of the third lens 230 .

[0102] The optical imaging system according to the second embodiment may have the following features: Figure 4 Table 3 shows the characteristics of the lens of the optical imaging system according to the second embodiment, and Table 4 shows the aspherical surface characteristics of the optical imaging system according to the second embodiment.

[0103] Table 3

[0104]

[0105] Table 4

[0106] Second embodiment S1 S2 S3 S4 S5 S6 S7 S8 S9 S10 Radius of curvature 2.19279196 1.089398458 5.436956125 -2.168731914 1.961950655 1.724601419 13.13899039 -0.716566637 1.322344757 0.554389232 K 0.00000 0.00000 -96.80463 4.42124 0.00000 -4.50605 99.00000 -0.77609 0.00000 -3.66851 A 0.198276 0.455134 -0.107547 -0.739839 -0.953608 -0.293012 0.255193 0.665143 -0.735327 -0.273636 B 0.011249 0.093926 0.692716 1.762464 1.311834 -0.109564 -0.636615 -1.325737 0.594517 0.204665 C -0.215004 1.868629 -15.616812 -7.798244 -4.049826 0.730042 1.097542 2.282118 -0.918076 -0.111688 D 0.460664 -10.560375 103.040539 23.000245 10.440480 -0.913554 -1.112725 -2.416037 1.201210 0.039079 E -0.363833 37.640371 -358.854999 -40.355988 -14.946486 0.316668 0.632429 1.503664 -1.031307 -0.008461 F 0.084883 -45.802151 477.321032 26.791611 8.525191 0.029463 -0.154086 -0.380997 0.479508 0.001002 G 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 -0.091447 -0.000049 H 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 J 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000

[0107] Will refer to Figure 5 An optical imaging system according to a third embodiment is described.

[0108] The first lens 310 may have a negative refractive power, and its object-side surface may be convex, and its image-side surface may be concave. The second lens 320 may have a positive refractive power, and its object-side surface may be convex, and its image-side surface may be convex. The third lens 330 may have a negative refractive power, and its object-side surface may be convex, and its image-side surface may be concave. In addition, an inflection point may be formed on the object-side surface and the image-side surface of the third lens 330. As an example, the object-side surface of the third lens 330 may be convex in its paraxial portion and concave in its edge portion, and the image-side surface of the third lens 330 may be concave in its paraxial portion and convex in its edge portion. The fourth lens 340 may have a positive refractive power, and its object-side surface may be convex, and its image-side surface may be convex. The fifth lens 350 may have a negative refractive power, and its object-side surface may be convex, and its image-side surface may be concave. In addition, an inflection point may be formed on the object-side surface and the image-side surface of the fifth lens 350. As an example, the object-side surface of the fifth lens 350 may be convex at a paraxial portion thereof and may be concave at an edge portion thereof, and the image-side surface of the fifth lens 350 may be concave at a paraxial portion thereof and may be convex at an edge portion thereof.

[0109] The optical imaging system 300 may include an image sensor 370 forming an imaging surface. The optical imaging system 300 may include an optical filter 360. The optical filter 360 may be disposed between the fifth lens 350 and the image sensor 370. The optical imaging system 300 may include a stop ST. The stop ST may be disposed between the first lens 310 and the second lens 320.

[0110] In the optical imaging system 300, the refractive indexes of the first lens 310, the third lens 330, and the fifth lens 350 may be greater than the refractive indexes of other lenses. Specifically, the first lens 310, the third lens 330, and the fifth lens 350 may have a refractive index of about 1.661, and the second lens 320 and the fourth lens 340 may have a refractive index of about 1.544, and the refractive indexes of the second lens 320 and the fourth lens 340 are less than the refractive indexes of the first lens 310, the third lens 330, and the fifth lens 350.

[0111] In the optical imaging system 300 , the third lens 330 may have a focal length having the largest absolute value. In an embodiment, the focal length of the third lens 330 may be about −8.23 mm, and the focal lengths of the other lenses may be greater than the focal length of the third lens 330 .

[0112] The optical imaging system according to the third embodiment may have the following features: Figure 6 Table 5 shows the characteristics of the lens of the optical imaging system according to the third embodiment, and Table 6 shows the aspherical surface characteristics of the optical imaging system according to the third embodiment.

[0113] Table 5

[0114]

[0115] Table 6

[0116] Third embodiment S1 S2 S3 S4 S5 S6 S7 S8 S9 S10 Radius of curvature 3.870058073 1.546550711 10.28321709 -1.418375059 2.862675543 1.815368291 74.05948473 -0.722186702 1.31051937 0.552533338 K 0.00000 0.00000 -96.80463 1.91204 0.00000 -1.55644 99.00000 -0.77008 0.00000 -3.63303 A 0.246228 0.477183 -0.214778 -0.618360 -0.894138 -0.375929 0.283148 0.662606 -0.738227 -0.271495 B -0.091476 0.126439 0.013129 2.565187 2.419177 0.618328 -0.613361 -1.302372 0.587993 0.191432 C -0.027202 0.318774 -4.923829 -9.702558 -5.702367 -0.829356 1.057966 2.207116 -0.951832 -0.098564 D 0.156316 -3.522727 21.048482 23.019022 9.507106 0.798591 -1.108043 -2.301321 1.279264 0.031833 E -0.112267 14.846437 42.363160 -31.387772 -9.089895 -0.497980 0.658226 1.410241 -1.108475 -0.006221 F 0.021039 -16.241587 -9.824457 15.776506 3.671254 0.134589 -0.167942 -0.352595 0.522214 0.000645 G 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 -0.102222 -0.000027 H 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 J 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000

[0117] Will refer to Figure 7 An optical imaging system according to a fourth embodiment is described.

[0118] The first lens 410 may have a negative refractive power, and its object-side surface may be convex, and its image-side surface may be concave. The second lens 420 may have a positive refractive power, and its object-side surface may be convex, and its image-side surface may be convex. The third lens 430 may have a negative refractive power, and its object-side surface may be convex, and its image-side surface may be concave. In addition, an inflection point may be formed on the object-side surface and the image-side surface of the third lens 430. As an example, the object-side surface of the third lens 430 may be convex at its paraxial portion and concave at its edge portion, and the image-side surface of the third lens 430 may be concave at its paraxial portion and convex at its edge portion. The fourth lens 440 may have a positive refractive power, and its object-side surface may be convex, and its image-side surface may be convex. The fifth lens 450 may have a negative refractive power, and its object-side surface may be convex, and its image-side surface may be concave. In addition, an inflection point may be formed on the object-side surface and the image-side surface of the fifth lens 450. As an example, the object-side surface of the fifth lens 450 may be convex at a paraxial portion thereof and concave at an edge portion thereof, and the image-side surface of the fifth lens 450 may be concave at a paraxial portion thereof and convex at an edge portion thereof.

[0119] The optical imaging system 400 may include an image sensor 470 forming an imaging surface. The optical imaging system 400 may include an optical filter 460. The optical filter 460 may be disposed between the fifth lens 450 and the image sensor 470. The optical imaging system 400 may include a stop ST. The stop ST may be disposed between the first lens 410 and the second lens 420.

[0120] In the optical imaging system 400, the refractive indexes of the first lens 410, the third lens 430, and the fifth lens 450 may be greater than the refractive indexes of other lenses. Specifically, the first lens 410, the third lens 430, and the fifth lens 450 may have a refractive index of about 1.661, and the second lens 420 and the fourth lens 440 may have a refractive index of about 1.544, and the refractive indexes of the second lens 420 and the fourth lens 440 are less than the refractive indexes of the first lens 410, the third lens 430, and the fifth lens 450.

[0121] In the optical imaging system 400 , the third lens 430 may have a focal length having the largest absolute value. In an embodiment, the focal length of the third lens 430 may be about −8.85 mm, and the focal lengths of the other lenses may be greater than the focal length of the third lens 430 .

[0122] The optical imaging system according to the fourth embodiment may have the following features: Figure 8 Table 7 shows the characteristics of the lens of the optical imaging system according to the fourth embodiment, and Table 8 shows the aspherical surface characteristics of the optical imaging system according to the fourth embodiment.

[0123] Table 7

[0124]

[0125] Table 8

[0126] Fourth embodiment S1 S2 S3 S4 S5 S6 S7 S8 S9 S10 Radius of curvature 4.060203826 1.592987031 8.836278242 -1.514104128 2.504749709 1.689866781 37.36016822 -0.7191191 1.311154543 0.555075821 K 0.00000 0.00000 -96.80463 1.85760 0.00000 -1.83097 99.00000 -0.77126 0.00000 -3.78121 A 0.242382 0.466606 -0.171925 -0.604529 -0.886692 -0.381078 0.285630 0.703664 -0.739670 -0.254505 B -0.062039 0.206024 0.092698 2.469228 2.268378 0.589971 -0.582260 -1.409937 0.664995 0.177839 C -0.088683 0.424040 4.927126 -9.356664 -5.237799 -0.775827 0.942664 2.444889 -1.135120 -0.093895 D 0.222032 -5.068666 24.940776 21.688561 8.608267 0.777208 -0.956880 -2.584995 1.535753 0.030426 E -0.147657 18.481333 -74.903367 -28.037262 -8.043410 -0.519579 0.562125 1.559771 -1.356597 -0.005865 F 0.027293 -18.736071 79.648860 13.103807 3.140271 0.148324 -0.143887 -0.380011 0.647281 0.000596 G 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 -0.125703 -0.000024 H 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 J 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000

[0127] Table 9 shows values ​​of conditional expressions of the optical imaging systems according to the first to fourth embodiments.

[0128] Table 9

[0129]

[0130] In the optical imaging system, the focal length of the first lens may be in the range of about -5.0 mm to about -2.5 mm. In the optical imaging system, the focal length of the second lens may be in the range of about 2.0 mm to about 4.0 mm. In the optical imaging system, the focal length of the third lens may be substantially determined in the range of about -50 mm to about -6.0 mm. In the optical imaging system, the focal length of the fourth lens may be in the range of about 1.0 mm to about 3.0 mm. In the optical imaging system, the focal length of the fifth lens may be in the range of about -3.0 mm to about -1.0 mm. The total focal length of the optical imaging system may be substantially determined in the range of about 1.0 mm to about 1.8 mm. The total length (TTL) of the optical imaging system may be in the range of about 3.8 mm to about 4.8 mm.

[0131] As described above, according to the embodiments, an optical imaging system having a low F number (F No.) and a wide angle of view may be realized.

[0132] The optical imaging system of the above-described embodiment may be applied to an electronic device, for example, an electronic device such as a mobile communication terminal or a camera, etc. The electronic device may have an F number less than about 2.3 and may have a field of view of about 100° or more, for example, may have a field of view of about 100° to about 120°.

[0133] Although the present disclosure includes specific examples, it will be apparent after understanding the disclosure of the present application that various changes in form and detail may be made in these examples without departing from the spirit and scope of the claims and their equivalents. The examples described herein will be considered as descriptive meanings only, and not for limiting purposes. The description of the features or aspects in each example will be considered to be applicable to similar features or aspects in other examples. If the described techniques are performed in a different order, and / or if the components in the described system, architecture, device or circuit are combined in a different manner and / or replaced or supplemented with other components or their equivalents, suitable results may be obtained. Therefore, the scope of the present disclosure is not limited by specific embodiments, but by the claims and their equivalents, and all variations within the scope of the claims and their equivalents will be interpreted as included in the present disclosure.

Claims

1. An optical imaging system, characterized in that: The optical imaging system comprises: a first lens including a negative refractive power; A second lens element including a positive refractive power and a convex image-side surface; a third lens including a negative refractive power; a fourth lens element including a positive refractive power and a convex object-side surface; and The fifth lens element includes a negative refractive power, Wherein, the first lens to the fifth lens are arranged in sequence from the object side, Wherein, the optical imaging system has a total of five lenses with refractive power, Wherein, 4.0<|f3 / f|, wherein f is the total focal length of the optical imaging system, and f3 is the focal length of the third lens, Among them, f≤1.76mm, wherein the first lens has a focal length in the range of -5.0 mm to -2.5 mm, and Wherein, the field of view of the optical imaging system is 120° or larger.

2. The optical imaging system according to claim 1, characterized in that: The first lens has a concave image-side surface.

3. The optical imaging system according to claim 1, characterized in that: The second lens has a convex object-side surface.

4. The optical imaging system according to claim 1, characterized in that: The third lens has a convex object-side surface.

5. The optical imaging system according to claim 1, characterized in that: The third lens has a concave image-side surface.

6. The optical imaging system according to claim 1, characterized in that: The fourth lens has a convex image-side surface.

7. The optical imaging system according to claim 1, characterized in that: The fifth lens has a convex object-side surface.

8. The optical imaging system according to claim 1, characterized in that: The fifth lens has a concave image-side surface.

9. The optical imaging system according to claim 1, characterized in that: The third lens has a refractive index of 1.6 or greater.

10. The optical imaging system according to claim 1, characterized in that: The fifth lens has a refractive index of 1.6 or greater.

11. The optical imaging system according to claim 1, characterized in that: TTL / ImgHT<2.0, wherein TTL is the distance from the object surface of the first lens to the imaging plane, and ImgHT is half of the diagonal length of the imaging plane.

12. An optical imaging system, characterized in that: The optical imaging system comprises: a first lens including a negative refractive power; A second lens element including a positive refractive power and a convex image-side surface; A third lens including a negative refractive power and a convex object-side surface; a fourth lens element including a positive refractive power and a convex object-side surface; and The fifth lens element includes a negative refractive power, Wherein, the first lens to the fifth lens are arranged in sequence from the object side, Wherein, the optical imaging system has a total of five lenses with refractive power, Wherein, the F number of the optical imaging system is less than 2.3, Wherein, the field of view of the optical imaging system is 120° or greater, Where f≤1.76mm, and Wherein, the first lens has a focal length in the range of -5.0 mm to -2.5 mm.

13. The optical imaging system according to claim 12, characterized in that: The first lens has a concave image-side surface.

14. The optical imaging system according to claim 12, characterized in that: The fifth lens has a convex object-side surface.

15. The optical imaging system according to claim 12, characterized in that: The fifth lens has a concave image-side surface.

16. The optical imaging system according to claim 12, characterized in that: |f1 / f|<4.0, wherein f is the total focal length of the optical imaging system, and f1 is the focal length of the first lens.

17. The optical imaging system according to claim 12, characterized in that: The focal length of the fifth lens is in the range of -3.0 mm to -1.5 mm.

Images