Patent ID: 12196919

Throughout the drawings and the detailed description, the same reference numerals refer to the same elements. The drawings may not be to scale, and the relative size, proportions, and depiction of elements in the drawings may be exaggerated for clarity, illustration, and convenience.

DETAILED DESCRIPTION

The following detailed description is provided to assist the reader in gaining a comprehensive understanding of the methods, apparatuses, and/or systems described herein. However, various changes, modifications, and equivalents of the methods, apparatuses, and/or systems described herein will be apparent to one of ordinary skill in the art. The sequences of operations described herein are merely examples, and are not limited to those set forth herein, but may be changed as will be apparent to one of ordinary skill in the art, with the exception of operations necessarily occurring in a certain order. Also, descriptions of functions and constructions that are well known to one of ordinary skill in the art may be omitted for increased clarity and conciseness.

The features described herein may be embodied in different forms, and are not to be construed as being limited to the examples described herein. Rather, the examples described herein have been provided so that this disclosure will be thorough and complete, and will convey the full scope of the disclosure to one of ordinary skill in the art.

Throughout the specification, it is to be understood that when an element, such as a layer, region or wafer (substrate), is referred to as being “on,” “connected to,” or “coupled to” another element, it may be directly “on,” “connected to,” or “coupled to” the other element or other elements intervening between the elements may be present. In contrast, when an element is referred to as being “directly on,” “directly connected to,” or “directly coupled to” another element, there are no elements or layers intervening between the elements. Like numerals refer to like elements throughout. Also, as used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.

It is intended to be apparent that although the terms first, second, third, etc. are used herein to describe various members, components, regions, layers and/or sections, these members, components, regions, layers and/or sections are not to be limited by these terms. These terms are only used to distinguish one member, component, region, layer or section from another region, layer or section. Thus, a first member, component, region, layer or section discussed below could also be termed a second member, component, region, layer or section or otherwise identified in a similar manner without departing from the embodiments.

Spatially relative terms, such as “above,” “upper,” “below,” and “lower” and the like, are used herein for ease of description to describe one element's relationship to another element(s) as shown in the figures. It is to be understood that the spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “above,” or “upper” other elements would then be oriented “below,” or “lower” the other elements or features, as appropriate. Thus, the term “above” encompasses both the above and below orientations, depending on a particular direction of the figures. The device is also possibly otherwise oriented, such as being rotated 90 degrees or at other arbitrary orientations and the spatially relative descriptors used herein are to be interpreted accordingly.

The terminology used herein is for describing particular embodiments only and is not intended to be limiting of the present embodiments. As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It is to be further understood that the terms “comprises,” and/or “comprising” when used in this specification, specify the presence of stated features, integers, steps, operations, members, elements, and/or groups thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, members, elements, and/or groups thereof.

Hereinafter, embodiments are described with reference to schematic views illustrating aspects of the embodiments. However, in the drawings, for example, due to manufacturing techniques and/or tolerances, modifications of the shape shown may be estimated. Thus, embodiments are not to be construed as being limited to the particular shapes of regions shown herein, for example, to include a change in shape results in manufacturing. The following embodiments may also be constituted by having features illustrated in one or a combination of the drawings.

The contents of the present embodiments described below may have a variety of configurations. The present descriptions describe only certain aspects of a possible configuration of the embodiments, but the embodiments are not to be limited thereto.

An aspect of the present embodiments provides an optical imaging system that has a high level of resolution.

In addition, in the present specification, a first lens refers to a lens closest to an object or a subject that is to be photographed, while a sixth lens refers to a lens closest to an imaging plane or an image sensor that measures light incident upon it to generate the data for the photograph.

In addition, as discussed subsequently, all of radii of curvature and thicknesses of lenses, a through-the lens (TTL) aspect, an Img HT, such as ½ of a diagonal length of the imaging plane, and focal lengths are represented by millimeters (mm). In an embodiment, a TTL aspect refers to a feature of cameras whereby light levels are measured through the lens that captures the picture, as opposed to a separate metering window. Further, thicknesses of the lenses, gaps between the lenses, and the TTL are distances with respect to optical axes of the lenses. Further, in a description for shapes of the lenses, the meaning referred to that one surface of a lens is convex is that an optical axis portion of a corresponding surface is convex, and the meaning referred to that one surface of a lens is concave is that an optical axis portion of a corresponding surface is concave. Therefore, although it is described that one surface of a lens is convex, an edge portion of the lens is possibly concave. Likewise, although it is described that one surface of a lens is concave, an edge portion of the lens is possibly convex.

In an embodiment, an optical imaging system includes six lenses sequentially disposed from an object side toward an imaging plane. Next, respective lenses are described in further detail.

In this embodiment, the first lens has a refractive power. For example, the first lens has a positive refractive power.

The first lens may include a planar region. For example, a paraxial region of an object-side surface of the first lens may be a planar region. For example, the paraxial region refers to the hypothetical cylindrical narrow space surrounding the optical axis within which rays of light are still considered paraxial, or parallel to the axis. The first lens formed as described above is potentially easily processed.

In an embodiment, the first lens has an aspherical surface. For example, both surfaces of the first lens are aspherical. The first lens may be formed of a material that has a high light transmissivity and an excellent workability. For example, the first lens is possibly formed of plastic. For example, a variety of plastics are appropriate materials for use in the first lens. However, a material of the first lens is not to be limited to plastic. For example, the first lens is instead possibly formed of glass. In other embodiments, other appropriate materials that conform to the above characteristics with respect to desirable features of lens materials are used instead of plastic or glass.

In an embodiment, the second lens has a refractive power. For example, the second lens has a positive refractive power.

In such an embodiment, at least one surface of the second lens is convex. For example, an object-side surface of the second lens is convex.

The second lens may have an aspherical surface. For example, an object-side surface of the second lens is aspherical. The second lens may also be formed of a material having high light transmissivity and excellent workability, such as discussed above with respect to the first lens. For example, the second lens is formed of the same material as the first lens, or another material such as an appropriate plastic or glass material, or another material with appropriate attributes.

In an embodiment, the third lens has a refractive power. For example, the third lens has a negative refractive power.

In such an embodiment, at least one surface of the third lens is convex. For example, both surfaces of the third lens are convex.

The third lens may have an aspherical surface. For example, an image-side surface of the third lens is aspherical. The third lens may also be formed of a material having high light transmissivity and excellent workability. For example, the third lens is formed of the same material as the other lenses, or another material such as an appropriate plastic or glass material, or another material with appropriate attributes.

In an embodiment, the fourth lens has a refractive power. For example, the fourth lens has a negative refractive power.

In such an embodiment, one surface of the fourth lens is convex. For example, an object-side surface of the fourth lens is convex. Also, in such an embodiment, the fourth lens has an inflection point. For example, one or more inflection points are formed on an object-side surface and the image-side surface of the fourth lens.

The fourth lens may have an aspherical surface. For example, both surfaces of the fourth lens are aspherical. The fourth lens may also be formed of a material having high light transmissivity and excellent workability. For example, the fourth lens is formed of the same material as the other lenses, or another material such as an appropriate plastic or glass material, or another material with appropriate attributes.

In an embodiment, the fifth lens has a refractive power. For example, the fifth lens has a positive refractive power.

In such an embodiment, one surface of the fifth lens is concave. For example, an object-side surface of the fifth lens is concave.

The fifth lens may have an aspherical surface. For example, both surfaces of the fifth lens are aspherical. The fifth lens may also be formed of a material having high light transmissivity and excellent workability. For example, the fifth lens is formed of the same material as the other lenses, or another material such as an appropriate plastic or glass material, or another material with appropriate attributes.

In an embodiment, the sixth lens has a refractive power. For example, the sixth lens has a negative refractive power.

In such an embodiment, one surface of the sixth lens may be convex. For example, an object-side surface of the sixth lens is convex. Also, in such an embodiment, the sixth lens has inflection points. For example, one or more inflection points are formed on both surfaces of the sixth lens.

The sixth lens may have an aspherical surface. For example, both surfaces of the sixth lens are aspherical. The sixth lens may also be formed of a material having high light transmissivity and excellent workability. For example, the sixth lens is formed of the same material as the other lenses, or another material such as an appropriate plastic or glass material, or another material with appropriate attributes.

In an embodiment, the first to sixth lenses are formed of materials having a refractive index different from that of air. For example, the first to sixth lenses, as discussed, may be formed of plastic or glass. However, plastic and glass are only examples and other materials that have an appropriate refractive index may be used in an embodiment. In an embodiment, at least one of the first to sixth lenses has an aspherical shape. As an example, all of the first to sixth lenses may have the aspherical shape. For example, an aspherical surface of each lens is represented by the following Equation 1:

z=c⁢r21+1-(1+k)⁢c2⁢r2+Ar4+Br6+C⁢r8+D⁢r1⁢0+Er1⁢2+Fr14+Gr16+Hr18+Jr20.Equation⁢1

For example, in Equation 1, c is an inverse of a radius of curvature of the lens, k is a conic constant, r is a distance from a certain point on an aspherical surface of the lens to an optical axis of the lens, A to J are aspherical constants, and Z or SAG is a distance between the certain point on the aspherical surface of the lens at the distance Y and a tangential plane that meets the apex of the aspherical surface of the lens.

In an embodiment, the optical imaging system includes a stop. The stop may be disposed between the second and third lenses. For example, a stop is a limiting diameter that determines the amount of light which reaches the imaging area, and may be and possibly takes the form of an adjustable diaphragm near the front of the lens.

In an embodiment, the optical imaging system includes a filter. Such a filter controls the wavelengths of light that are imaged by the optical imaging system. The filter filters a partial wavelength from light passing through the first to sixth lenses. For example, the filter filters an infrared wavelength of the incident light. In such an example, the filter is manufactured to have a reduced thickness. To this end, the filter is formed of plastic.

Also, in an embodiment, the optical imaging system includes an image sensor. The image sensor provides an imaging plane upon which light refracted by the lenses is imaged. For example, a surface of the image sensor forms the imaging plane. In this embodiment, the image sensor is configured to realize a high resolution. For example, a unit size of pixels comprising the image sensor may be 1.12 μm or less.

The optical imaging system may satisfy the following Conditional Expressions, with respect to the characteristics of the system:
0.015<(TTL/f)/FOV<0.025  Conditional Expression 1
BL/f<0.5  Conditional Expression 2
R3/f<0.5  Conditional Expression 3
V1−V2<−25  Conditional Expression 4
0.2<(R7−R8)/(R7+R8)<0.8  Conditional Expression 5
0.4<(R9−R10)/(R9+R10)<0.6  Conditional Expression 6
SL/TTL<0.85  Conditional Expression 7
D12/TTL<0.03  Conditional Expression 8
D56/TTL<0.85  Conditional Expression 9

In an embodiment, TTL denotes a distance from the object-side surface of the first lens to the imaging plane, BL denotes a distance from an image-side surface of the sixth lens to the imaging plane, f denotes an overall focal length of the optical imaging system, R3 denotes a radius of curvature of the object-side surface of the second lens, V1 denotes an Abbe number of the first lens, V2 denotes an Abbe number of the second lens, R7 denotes a radius of curvature of the object-side surface of the fourth lens, R8 denotes a radius of curvature of the image-side surface of the fourth lens, R9 denotes a radius of curvature of the object-side surface of the fifth lens, R10 denotes a radius of curvature of an image-side surface of the fifth lens, SL denotes a distance from the stop to the imaging plane, D12 denotes a distance from an image-side surface of the first lens to the object-side surface of the second lens, and D56 denotes a distance from the image-side surface of the fifth lens to the object-side surface of the sixth lens. For instance, an Abbe number is a measure of the dispersion of the material of a lens, with respect to variation of refractive index versus wavelength. The optical imaging system satisfying the above Conditional Expressions, according to an embodiment, is miniaturized, and realizes a relatively high resolution.

Next, optical imaging systems according to several embodiments are described.

First, an optical imaging system according to a first embodiment is described further with reference toFIG.1.

The optical imaging system100according to the first embodiment includes a plurality of lenses, each having a refractive power. For example, the optical imaging system100includes a first lens110, a second lens120, a third lens130, a fourth lens140, a fifth lens150, and a sixth lens160.

In the embodiment ofFIG.1, the first lens110has a positive refractive power, where a paraxial region of an object-side surface of the first lens110is a plane and an image-side surface of the first lens110is convex. The second lens120has a positive refractive power, and an object-side surface of the second lens120is convex and an image-side surface of the second lens120is concave. The third lens130has a positive refractive power, and an object-side surface of the third lens130is convex and an image-side surface of the third lens130is convex. The fourth lens140has a negative refractive power, and an object-side surface of the fourth lens140is convex and an image-side surface of the fourth lens140is concave. In addition, an inflection point is formed on the fourth lens140. For example, the image-side surface of the fourth lens140is concave in a paraxial region of the fourth lens140, and is convex in the vicinity of the paraxial region of the fourth lens140. The fifth lens150has a positive refractive power, and an object-side surface of the fifth lens150is concave and an image-side surface of the fifth lens150is convex. The sixth lens160has a negative refractive power, and an object-side surface of the sixth lens160is convex and an image-side surface of the sixth lens160is concave. In addition, inflection points are formed on both surfaces of the sixth lens160. For example, the object-side surface of the sixth lens160is convex in a paraxial region of the sixth lens160, and is concave in the vicinity of the paraxial region of the sixth lens160. Similarly, the image-side surface of the sixth lens160is concave in a paraxial region of the sixth lens160, and is convex in the vicinity of the paraxial region of the sixth lens160.

In the embodiment ofFIG.1, the optical imaging system100includes a stop ST, as explained further, above. For example, the stop ST is located between the second lens120and the third lens130. The stop ST located as described above adjusts an amount of light incident to an imaging plane180.

Also, in the embodiment ofFIG.1, the optical imaging system100includes a filter170. For example, the filter170is located between the sixth lens160and the imaging plane180. The filter170located as described above filters infrared rays incident onto the imaging plane180. However, other frequencies of light are filtered in other embodiments, as appropriate.

The optical imaging system100includes an image sensor. The image sensor provides the imaging plane180upon which light refracted through the lenses is imaged. In addition, the image sensor converts an optical signal imaged on the imaging plane180into an electrical signal for use by a computer or another appropriate electronic device.

The optical imaging system configured as described above provides representative aberration characteristics and modulation transfer function (MTF) characteristics as illustrated in the graphs presented inFIGS.2and3.FIGS.4and5are tables representing characteristics of lenses and aspherical characteristics of the optical imaging system according to the embodiment ofFIG.1.

An optical imaging system according to a second embodiment is described with reference toFIG.6.

The optical imaging system200according to the second embodiment illustrated inFIG.6includes a plurality of lenses, each having a refractive power. For example, the optical imaging system200includes a first lens210, a second lens220, a third lens230, a fourth lens240, a fifth lens250, and a sixth lens260.

In the embodiment ofFIG.6, the first lens210has a positive refractive power, and a paraxial region of an object-side surface of the first lens210is a plane and an image-side surface of the first lens210is convex. The second lens220has a positive refractive power, and an object-side surface of the second lens220is convex and an image-side surface of the second lens220is concave. The third lens230has a positive refractive power, and an object-side surface of the third lens230is convex and an image-side surface of the third lens230is convex. The fourth lens240has a negative refractive power, and an object-side surface of the fourth lens240is convex and an image-side surface of the fourth lens240is concave. In addition, an inflection point is formed on the fourth lens240. For example, the image-side surface of the fourth lens240is concave in a paraxial region of the fourth lens240, and is convex in the vicinity of the paraxial region of the fourth lens240. The fifth lens250has a positive refractive power, and an object-side surface of the fifth lens250is concave and an image-side surface of the fifth lens is convex. The sixth lens260has a negative refractive power, and an object-side surface of the sixth lens is convex and an image-side surface of the sixth lens260is concave. In addition, inflection points are formed on both surfaces of the sixth lens260. For example, the object-side surface of the sixth lens is convex in a paraxial region of the sixth lens260, and is concave in the vicinity of the paraxial region of the sixth lens260. Similarly, the image-side surface of the sixth lens260is concave in a paraxial region of the sixth lens260, and is convex in the vicinity of the paraxial region of the sixth lens260.

In the embodiment ofFIG.6, the optical imaging system200includes a stop ST. For example, the stop ST is located between the second lens220and the third lens230. The stop ST located as described above adjusts an amount of light incident onto an imaging plane280.

In this embodiment, the optical imaging system200includes a filter270. For example, the filter270is located between the sixth lens260and the imaging plane280. The filter270located as described above filters infrared rays incident onto the imaging plane280. However, other frequencies of light are filtered in other embodiments, as appropriate.

The optical imaging system200includes an image sensor. The image sensor may provide the imaging plane280on which light refracted through the lenses is imaged. In addition, the image sensor may convert an optical signal imaged on the imaging plane280into an electrical signal for use by a computer or another appropriate electronic device.

The optical imaging system configured as described above provides representative aberration characteristics and MTF characteristics as illustrated inFIGS.7and8.FIGS.9and10are tables representing characteristics of lenses and aspherical characteristics of the optical imaging system according to the embodiment ofFIG.6.

An optical imaging system according to a third embodiment is described with reference toFIG.11.

The optical imaging system300according to the third embodiment illustrated inFIG.11includes a plurality of lenses, each having a refractive power. For example, the optical imaging system300includes a first lens310, a second lens320, a third lens330, a fourth lens340, a fifth lens350, and a sixth lens360.

The first lens310has a positive refractive power, and a paraxial region of an object-side surface of the first lens310is a plane and an image-side surface of the first lens310is convex. The second lens320has a positive refractive power, and an object-side surface of the second lens320is convex and an image-side surface of the second lens is concave. The third lens330has a positive refractive power, and an object-side surface of the third lens330is convex and an image-side surface of the third lens330is convex. The fourth lens340has a negative refractive power, and an object-side surface of the fourth lens340is convex and an image-side surface of the fourth lens340is concave. In addition, an inflection point is formed on the fourth lens340. For example, the image-side surface of the fourth lens340is concave in a paraxial region of the fourth lens340, and is convex in the vicinity of the paraxial region of the fourth lens340. The fifth lens350has a positive refractive power, and an object-side surface of the fifth lens350is concave and an image-side surface of the fifth lens350is convex. The sixth lens360has a negative refractive power, and an object-side surface of the sixth lens360is convex and an image-side surface of the sixth lens360is concave. In addition, inflection points are formed on both surfaces of the sixth lens360. For example, the object-side surface of the sixth lens may be convex in a paraxial region of the sixth lens360, and is concave in the vicinity of the paraxial region of the sixth lens360. Similarly, the image-side surface of the sixth lens360is concave in a paraxial region of the sixth lens360, and is convex in the vicinity of the paraxial region of the sixth lens360.

In the embodiment ofFIG.11, the optical imaging system300includes a stop ST. For example, the stop ST is located between the second lens320and the third lens330. The stop ST located as described above may adjust an amount of light incident onto an imaging plane380.

In this embodiment, the optical imaging system300includes a filter370. For example, the filter370is located between the sixth lens360and the imaging plane380. The filter370disposed as described above filters infrared rays incident onto the imaging plane380. However, other frequencies of light are filtered in other embodiments, as appropriate.

The optical imaging system300includes an image sensor. The image sensor provides the imaging plane380on which light refracted through the lenses is imaged. In addition, the image sensor converts an optical signal imaged on the imaging plane380into an electrical signal for use by a computer or another appropriate electronic device.

The optical imaging system configured as described above provides representative aberration characteristics and MTF characteristics as illustrated inFIGS.12and13.FIGS.14and15are tables representing characteristics of lenses and aspherical characteristics of the optical imaging system according to the embodiment ofFIG.11.

An optical imaging system according to a fourth embodiment is described with reference toFIG.16.

The optical imaging system400according to the fourth embodiment includes a plurality of lenses, each having a refractive power. For example, the optical imaging system400includes a first lens410, a second lens420, a third lens430, a fourth lens440, a fifth lens450, and a sixth lens460.

The first lens410has a positive refractive power, and a paraxial region of an object-side surface of the first lens410is a plane and an image-side surface of the first lens410is convex. The second lens420has a positive refractive power, and an object-side surface of the second lens420is convex and an image-side surface of the second lens420is concave. The third lens430has a positive refractive power, and an object-side surface of the third lens430is convex and an image-side surface of the third lens430is convex. The fourth lens440has a negative refractive power, and an object-side surface of the fourth lens440is convex and an image-side surface of the fourth lens440is concave. In addition, an inflection point is formed on the fourth lens440. For example, the image-side surface of the fourth lens440is concave in a paraxial region of the fourth lens440, and is convex in the vicinity of the paraxial region. The fifth lens450has a positive refractive power, and an object-side surface of the fifth lens450is concave and an image-side surface of the fifth lens450is convex. The sixth lens460has a negative refractive power, and an object-side surface of the sixth lens460is convex and an image-side surface of the sixth lens460is concave. In addition, inflection points are formed on both surfaces of the sixth lens460. For example, the object-side surface of the sixth lens is convex in a paraxial region of the sixth lens460, and is concave in the vicinity of the paraxial region of the sixth lens460. Similarly, the image-side surface of the sixth lens is concave in a paraxial region of the sixth lens460, and is convex in the vicinity of the paraxial region of the sixth lens460.

In the embodiment ofFIG.16, the optical imaging system400includes a stop ST. For example, the stop ST is located between the second lens420and the third lens430. The stop ST disposed as described above adjusts an amount of light incident onto an imaging plane480.

In this embodiment, the optical imaging system400includes a filter470. For example, the filter470is disposed between the sixth lens460and the imaging plane480. The filter470disposed as described above filters infrared rays incident onto the imaging plane480. However, other frequencies of light are filtered in other embodiments, as appropriate.

The optical imaging system400includes an image sensor. The image sensor provides the imaging plane480on which light refracted through the lenses is imaged. In addition, the image sensor may convert an optical signal imaged on the imaging plane480into an electrical signal for use by a computer or another appropriate electronic device.

The optical imaging system configured as described above provides aberration characteristics and MTF characteristics as illustrated inFIGS.17and18.FIGS.19and20are tables representing characteristics of lenses and aspherical characteristics of the optical imaging system according to the embodiment ofFIG.16.

Table 1 represents values of Conditional Expressions of the optical imaging systems according to the first to fourth embodiments presented as examples. As seen in Table 1, the optical imaging systems according to the first to fourth exemplary embodiments each satisfy all numerical ranges according to Conditional Expressions described above, in the present disclosure.

TABLE 1ConditionalFirstSecondThirdFourthExpressionEmbodimentEmbodimentEmbodimentEmbodiment(TTL/f)/FOV0.02000.02000.01800.0200BL/f0.45370.48470.41980.4413R3/f0.55770.63670.58340.5444V1 − V2−30.512−30.512−30.512−30.512(R7 − R8)/0.47600.72880.33500.2643(R7 + R8)(R9 − R10)/0.54400.55690.48220.5315(R9 + R10)SL/TTL0.79140.77890.79030.7817D1/TTL0.01210.01390.01350.0121D11/TTL0.01210.01210.04580.121

While this disclosure includes specific examples, it will be apparent to one of ordinary skill in the art that various changes in form and details may be made in these examples without departing from the spirit and scope of the claims and their equivalents. The examples described herein are to be considered in a descriptive sense only, and not for purposes of limitation. Descriptions of features or aspects in each example are to be considered as being applicable to similar features or aspects in other examples. Suitable results may be achieved if the described techniques are performed in a different order, and/or if components in a described system, architecture, device, or circuit are combined in a different manner, and/or replaced or supplemented by other components or their equivalents. Therefore, the scope of the disclosure is defined not by the detailed description, but by the claims and their equivalents, and all variations within the scope of the claims and their equivalents are to be construed as being included in the disclosure.