KR20230060436A - Lens assembly, imaging apparatus and electronic apparatus employing the same - Google Patents

Abstract

A lens assembly, and an imaging device and an electronic device including the same are disclosed. The disclosed lens assembly includes, arranged from a subject side to an image side, a first refractive lens; a second refractive lens; and a meta-lens disposed between the second refractive lens and the image side. Thus, the present invention can provide the lens assembly, and the imaging device and electronic device including the same that can implement telephoto cameras of various magnifications.

Description

Lens assembly, imaging apparatus and electronic apparatus including the same {Lens assembly, imaging apparatus and electronic apparatus employing the same}

It relates to a lens assembly including a meta lens, and an imaging device and an electronic device including the same.

An imaging device having an image sensor such as a charge coupled device (CCD) or a complementary metal-oxide semiconductor (CMOS), for example, a camera, is used as an optical device for capturing images or moving pictures. A lens assembly composed of a combination of a plurality of lenses may be used in a camera to obtain high quality images and/or moving pictures. A camera including such a lens assembly and an image sensor may be mounted in various electronic devices, such as augmented reality or virtual reality devices and small electronic devices such as portable wireless terminals.

In order to obtain high-quality images and / or videos, at least some of the plurality of lenses constituting the lens assembly are configured to remove various aberrations that degrade image quality, and such a configuration increases the total length of the lens assembly, so that the camera It is difficult to miniaturize. In addition, in a portable wireless terminal such as a smart phone, it is difficult to implement a camera having a lens assembly with high performance and various magnifications due to limitations in mounting space and lens material.

A lens assembly capable of realizing a telephoto camera with various magnifications, and an imaging device and electronic device to which the same is applied are provided.

A lens assembly according to one type is arranged from the subject side to the image side, the first refractive lens; a second refractive lens; and a meta lens disposed between the second refractive lens and the image surface, wherein the meta lens includes: a first meta lens; and a second meta-lens spaced apart from the first meta-lens.

The first refractive lens may have a positive refractive power and be formed of a low-dispersion material, and the second refractive lens may have a negative refractive power and be formed of a high-dispersion material.

The first refractive lens may be formed of a plastic material having an Abbe number of 45 or more and 65 or less.

The second refractive lens may be formed of a plastic material having an Abbe number of 25 or more and 45 or less.

The second refractive lens may be formed of a plastic material having an Abbe number of 25 or more and 45 or less.

The first refractive lens may be mainly provided to focus light, and at least one of the second refractive lens and the meta lens may be mainly provided to correct chromatic aberration.

The meta lens mainly contributes to correcting basic chromatic aberration, and the second refractive lens may mainly contribute to correcting secondary chromatic aberration.

It may further include an optical element that bends in the traveling direction of light at any one place between the second refractive lens and the meta lens and between the meta lens and the image surface.

The optical element may be a prism.

Between the meta lens and the image surface, at least one refracting lens for focusing light incident at a high incident angle onto the image surface may be further included.

A spacer may be further included between the first meta-lens and the second meta-lens.

The first and second meta-lenses may include an array of a plurality of nanostructures having a shape dimension smaller than an operating wavelength and having a width that varies depending on a position.

The plurality of nanostructures may be prepared to have a refractive index higher than or lower than 0.5 of surrounding materials.

The plurality of nanostructures are formed of at least one of c-Si, p-Si, a-Si, III-V compound semiconductors (GaP, GaN, GaAs, etc.), SiC, TiO ₂ , TiSiOx, and SiN, It may be provided to have a higher refractive index than surrounding materials.

The plurality of nanostructures may be formed of any one of SiO2 and air to have a lower refractive index than surrounding materials.

At least one of the first and second meta-lenses may include a plurality of nanostructures and a surrounding material surrounding them, and an effective refractive index of the nanostructure may be greater than or less than an effective refractive index of the surrounding material.

In at least one of the first and second meta-lenses, layers including a plurality of nanostructures and peripheral materials surrounding them may be arranged in a single layer or in two or more layers.

An imaging device according to one type includes a lens assembly; and an image sensor for converting an optical image formed by the lens assembly into an electrical signal, wherein the lens assembly is arranged from a subject side to an image side, and includes a first refractive lens; a second refractive lens; And a meta lens disposed between the second refractive lens and the image surface,

The meta lens may include a first meta lens; and a second meta-lens spaced apart from the first meta-lens.

An electronic device according to one type includes a camera module, wherein the camera module is arranged from a subject side to an image side, and is disposed between a first refractive lens, a second refractive lens, and the second refractive lens and the image surface. A lens assembly including a meta lens to be; and an image sensor that converts an optical image formed by the lens assembly into an electrical signal, wherein the meta lens includes: a first meta lens; and a second meta-lens spaced apart from the first meta-lens.

The lens assembly according to the embodiment may implement a telephoto lens by including a first refractive lens, a second refractive lens, and a meta lens.

By applying the lens assembly according to this embodiment, it is possible to implement a telephoto camera with various magnifications. In addition, by applying a meta lens prepared to serve as a chromatic dispersion compensation based on an optical path difference between wavelengths, it is possible to overcome the limitations of mounting space and lens material.

1 schematically shows an optical configuration of a lens assembly according to an embodiment and an imaging device to which the same is applied.
2 and 3 schematically show modified examples of an optical configuration of a lens assembly and an imaging device to which the same is applied according to the embodiment.
4 schematically shows an optical configuration of a lens assembly and an imaging device to which the same is applied according to another embodiment.
5 is a cross-sectional view schematically showing a configuration of a meta lens applied to a lens assembly according to an embodiment.
6 is a cross-sectional view schematically showing another configuration example of a meta lens applied to a lens assembly according to an embodiment.
7 is a cross-sectional view schematically showing another configuration example of a meta lens applied to a lens assembly according to various embodiments described above.
8A is a plan view showing a schematic structure of a meta lens applied to a lens assembly according to an embodiment.
FIG. 8B exemplarily shows a phase profile implemented for each area of FIG. 8A.
9 and 10 show exemplary cross-sectional views of the meta lens of FIG. 8 .
11 shows focusing of light according to an incident direction when a lens assembly according to an embodiment is designed according to the design data of Tables 1 to 6.
12 shows Modulus of the OTF (MTF) performance of the lens assembly according to the embodiment when designed as shown in Tables 1 to 6 and FIG. 11 .
13 is a conceptual diagram illustrating an example of applying an imaging device including a lens assembly according to an embodiment to a mobile device as a telephoto camera.
14 shows an example of disposing a folded telephoto camera to which a lens assembly according to an embodiment is applied inside a mobile device.
15 is a block diagram showing a schematic configuration of an electronic device according to an embodiment.
16 is a block diagram showing a schematic configuration of a camera module provided in the electronic device of FIG. 15 as an example.

Hereinafter, exemplary embodiments will be described in detail with reference to the accompanying drawings. In the following drawings, the same reference numerals denote the same components, and the size of each component in the drawings may be exaggerated for clarity and convenience of description. On the other hand, the embodiments described below are merely illustrative, and various modifications are possible from these embodiments.

Hereinafter, what is described as “upper” or “upper” may include not only what is directly above, below, left, and right in contact, but also what is above, below, left, and right in non-contact. Singular expressions include plural expressions unless the context clearly dictates otherwise. In addition, when a certain component is said to "include", this means that it may further include other components without excluding other components unless otherwise stated.

The use of the term “above” and similar denoting terms may correspond to both singular and plural. Unless the order of steps constituting the method is explicitly stated or stated to the contrary, these steps may be performed in any suitable order, and are not necessarily limited to the order described.

In addition, terms such as "...unit" and "module" described in the specification mean a unit that processes at least one function or operation, which may be implemented as hardware or software or a combination of hardware and software. .

Connections of lines or connecting members between components shown in the drawings are examples of functional connections and / or physical or circuit connections, which can be replaced in actual devices or additional various functional connections, physical connections, or as circuit connections.

The use of all examples or exemplary terms is simply for explaining technical ideas in detail, and the scope is not limited due to these examples or exemplary terms unless limited by the claims.

The lens assembly according to the embodiment is composed of a combination of a plurality of refracting lenses and a meta lens, and may implement a telephoto lens assembly and a telephoto camera module with various magnifications. When the lens assembly according to the embodiment is applied, for example, while implementing a telephoto camera and an electronic device including the same, it is possible to overcome the limitation of mounting space and lens material of a portable wireless terminal such as a smart phone or various electronic devices.

The lens assembly according to the embodiment may be mounted in various electronic devices requiring a telephoto camera. Electronic devices according to this embodiment include smart phones, foldable phones, wearable devices, Internet of Things (IoT) devices, home appliances, tablet PCs (Personal Computers), desktop PCs, laptop PCs, game consoles, PDAs ( Personal Digital Assistant), PMP (portable multimedia player), medical devices, cameras, navigation, drones, robots, unmanned vehicles, autonomous vehicles, Advanced Drivers Assistance Systems (ADAS), etc. can include In addition, the electronic device according to the embodiment may include various devices to which a telephoto camera is applied.

Hereinafter, for convenience, an imaging device including a lens assembly and an image sensor according to an embodiment is expressed as a telephoto camera or the like as needed, but the embodiment is not limited thereto. For example, an imaging device including a lens assembly and an image sensor according to an embodiment may be implemented as not only a telephoto camera but also various types of cameras, and may be applied to various electronic devices requiring a camera module.

1 schematically shows an optical configuration of a lens assembly 20 and an imaging device 10 to which the lens assembly 20 according to the embodiment is applied.

Referring to FIG. 1 , an imaging device 10 converts a lens assembly 20 constituting an imaging lens and an optical image of an object OBJ formed by the lens assembly 20 into an electrical image signal. It may include an image sensor 50 that converts. An optical filter 40 such as an infrared cut filter may be further provided between the lens assembly 20 and the image sensor 50 . The optical filter 40 such as an infrared cut filter positioned in front of the image sensor 50 may or may not be considered as a component of the lens assembly 20 .

The lens assembly 20 according to the embodiment may include a first refractive lens 21, a second refractive lens 25, and a meta lens 100 arranged from the subject side O to the image side I. . The lens assembly 20 according to the embodiment may further include a refractive lens. An optical image of the object OBJ may be formed on the image surface by the lens assembly 20 . In the imaging device 10 including the lens assembly 20 according to the embodiment, the image sensor 50 may be disposed on an upper surface.

The first refractive lens 21 is provided to mainly focus light, has a positive refractive power, and may be formed of a low-dispersion material, for example, a low-dispersion plastic material. For example, the first refractive lens 21 may be formed of a plastic material having an Abbe number of about 45 or more and about 65 or less. The first refractive lens 21 may have a lens surface 21a facing the subject side O so as to have a relatively strong positive refractive power. When the first refractive lens 21 has strong positive refractive power, long-wavelength light may generate a positive chromatic aberration compared to short-wavelength light having a longer focal length.

The second refractive lens 25 has negative refractive power and may be formed of a high dispersion material, for example, a high dispersion plastic material. For example, the second refractive lens 25 may be formed of a plastic material having an Abbe number of about 25 or more and about 45 or less. The second refractive lens 25 is provided to have negative refractive power so as to correct chromatic aberration and/or curvature of field caused by other lenses, for example, the first refractive lens 21. can be provided.

For example, when the meta lens 100 is provided to mainly contribute to correcting primary chromatic aberration, the second refractive lens 25 may be provided to correct secondary chromatic aberration. In addition, the second refractive lens 25 may have an aspheric surface facing the subject side O and/or an aspheric surface facing the image side I. Distortion when passing through the marginal portion of the first refractive lens 21 and/or the second refractive lens 25 can be alleviated. In addition, the second refractive lens 25 is formed of a meniscus lens in which the lens surface 25a facing the image side (I) is formed concavely, so that the lens, for example, the first refractive lens 21 and/or Alternatively, it may be provided to improve coma aberration and astigmatism, which are phenomena in which light passing through the marginal portion of the second refractive lens 25 does not form a clear image.

Here, the lens having positive refractive power is a lens based on the principle of a convex lens having a positive focal length, and can condense light by passing light incident in parallel to the optical axis O-I. On the other hand, a lens having negative refractive power is a lens based on the principle of a concave lens, and can pass and disperse parallel incident light.

In the lens assembly 10 according to the embodiment, the meta lens 100 may be provided to correct chromatic aberration. The meta lens 100 may be provided to have negative chromatic aberration, and may correct some or all of the chromatic aberration generated by the first refractive lens 21 .

In general, a lens having negative refractive power, such as a Flint lens, is used to correct chromatic aberration. In this case, problems of refractive power loss and increase in the thickness of the lens assembly 20 may occur. When the meta lens 100 is applied to mainly contribute to primary chromatic aberration correction like the lens assembly 20 according to the embodiment, a loss of refractive power and a thickness of the lens assembly 20 can be reduced.

In the lens assembly 20 according to the embodiment, the meta lens 100 may be provided to mainly contribute to primary chromatic aberration correction. The meta lens 100 may include a first meta lens ML1 and a second meta lens ML2 as shown exemplarily in FIG. 5 to be described later.

For example, the first meta-lens ML1 has a first shape of the plurality of first nanostructures NS1 to have a predetermined phase delay function φ ₁ (r) representing positive refractive power. distribution can be determined. The second shape distribution of the plurality of second nanostructures NS2 is determined so that the second meta-lens ML2 has a predetermined phase delay function φ ₂ (r) representing negative refractive power. can

In this way, according to the lens assembly 20 according to the embodiment, the first refractive lens 21 is formed of a low-dispersion material to have a positive refractive power, and the second refractive lens 25 is formed of a high-dispersion material to have a negative refractive power. It may be formed of a material, and a meta lens 100 may be provided to correct chromatic aberration. In this case, the first refractive lens 21 may serve as a focusing mainly for imaging light. At least one of the second refractive lens 25 and the meta lens 100 may mainly serve to correct chromatic aberration. For example, the meta lens 100 may be provided to mainly contribute to correcting primary chromatic aberration, and the second refractive lens 25 may be provided to correct secondary chromatic aberration.

For example, the lens assembly 20 according to the embodiment includes a first refractive lens 21, a second refractive lens 25 and a meta lens 100, mainly by the first refractive lens 21. It may be provided to focus light, correct primary chromatic aberration by the meta lens 100, and correct secondary chromatic aberration by the second refractive lens 25.

The lens assembly 20 according to this embodiment may implement a telephoto lens as a hybrid lens assembly in which a refracting lens and a meta lens are combined, and may implement a hybrid telephoto camera when applied as an imaging optical system to an imaging device. When having an optical configuration as shown in FIG. 1, the lens assembly 20 according to the embodiment may be designed to have a magnification corresponding to a telephoto lens, for example, 2 or more and 20 or less, or 20 or more, The imaging device 10 to which the lens assembly 20 is applied may implement, for example, a telephoto camera.

On the other hand, FIG. 1 shows an example in which the lens assembly 20 according to the embodiment forms a vertical optical module structure, and may further include an optical element that bends a traveling path of light to have a folded optical module structure.

As shown exemplarily in FIGS. 2 to 4 , the lens assembly 20 according to the embodiment includes an additional lens and/or optical element between, before, or after the second refractive lens 25 and the meta lens 100 can be further provided.

2 and 3 schematically show modifications of the optical configuration of the lens assembly 20 according to the embodiment and the imaging device 10 to which the same is applied, when compared to the lens assembly 20 according to the embodiment of FIG. 1 , shows an example further comprising an optical element 30 that forms a folded optical system by bending the traveling direction of light.

For example, the lens assembly 20 according to the embodiment, as in the embodiment of FIGS. 2 and 3, an optical element 30 that bends the light path in the middle of the lens assembly 20, for example, a prism or reflection It may further include members. Here, it is described that the optical element 30 for bending the traveling path of light is included in the lens assembly 20, but is not limited thereto. The optical element 30 that bends the traveling path of light may or may not be considered as a component of the lens assembly 20 according to the embodiment.

As shown in FIG. 2 , the optical element 30 may be disposed between the meta lens 100 and the image surface. Also, as shown in FIG. 3 , the optical element 30 may be disposed between the second refractive lens 25 and the meta lens 100 .

2 and 3, when the optical element 30 is disposed between the meta lens 100 and the image surface or between the second refractive lens 25 and the meta lens 100, a fold-type optical system can be configured Therefore, it is possible to implement a folded telescopic camera (or a folded telescopic camera module) in the form of a periscope.

1 and 2, the design data of the first refractive lens 21, the second refractive lens 25, and the meta lens 100 are for bending the traveling direction of light between the meta lens 100 and the image surface. When the optical element 30 is provided with, for example, a prism, it may be different, and thus the magnification may be different.

In addition, referring to FIGS. 2 and 3, the design data of the first refractive lens 21, the second refractive lens 25, and the meta lens 100 is an optical element 30 for bending the traveling direction of light, for example, It may vary according to the position where the prism is disposed, and thus the magnification may vary.

When the lens assembly 20 has the optical configuration exemplarily shown in FIG. 2 , for example, an imaging device such as a folded telephoto camera having a magnification of about 3 to 7 times may be implemented. In addition, when the lens assembly 20 has the optical configuration exemplarily shown in FIG. 3 , for example, an imaging device such as a folded telephoto camera having a magnification of about 4 to 15 times may be implemented.

4 schematically shows an optical configuration of a lens assembly 120 and an imaging device 110 to which the lens assembly 120 according to another embodiment is applied. Compared to the lens assembly 20 according to the exemplary embodiment of FIGS. 1 to 3 , the lens assembly 120 of FIG. 4 shows an example in which an additional refracting lens is further provided between the meta lens 100 and the image surface. The number of additional refractive lenses may vary.

Referring to FIG. 4 , the lens assembly 120 according to the embodiment may further include at least one refracting lens between the meta lens 100 and the image surface for focusing light incident at a high incident angle on the image surface. . 4 shows an example in which third to fifth refractive lenses 121, 123, and 125 are further provided as additional refractive lenses between the meta lens 100 and the image surface. The number of additional refractive lenses may vary.

As exemplarily shown in FIG. 4, when at least one refractive lens, for example, the third to fifth refractive lenses 121, 123, and 125 is further provided between the meta lens 100 and the image surface, A telescopic imaging device such as a direct type telescopic camera may be implemented, and the imaging device such as a direct type telescopic camera may be provided to have a magnification of about 2 to 4 times, for example.

As shown in FIGS. 2 and 3, the lens assembly 120 of FIG. 4 is an optical element that bends the path of light between the meta lens 100 and the image surface or between the second refractive lens 25 and the meta lens 100 (30) For example, a prism or a reflective member may be further included. For example, the optical element 30 is further provided between the meta lens 100 and the third refractive lens 121, or the optical element 30 is provided between the second refractive lens 25 and the meta lens 100. more can be provided. As in the lens assembly 120 of FIG. 4, even when at least one refracting lens is further included between the meta lens 100 and the image surface, an optical element 30 for bending the traveling path of light is further provided, An imaging device such as a folded telescopic camera may be implemented.

5 is a cross-sectional view schematically showing the configuration of the meta lens 100 applied to the lens assemblies 20 and 120 according to various embodiments described above. 5 shows an example of the meta lens 100 applied to the lens assembly 20 or 120 according to the embodiment, but the embodiment is not limited thereto.

Referring to FIG. 5 , the meta-lens 100 according to the embodiment may include a first meta-lens ML1 and a second meta-lens ML2. The first meta-lens ML1 may include a plurality of first nanostructures NS1 , and the second meta-lens ML2 may include a plurality of second nanostructures NS2 . The meta-lens 100 may include a spacer 101 between the first meta-lens ML1 and the second meta-lens ML2.

The meta lens 100 may include only one of the first meta lens ML1 and the second meta lens ML2. In addition, the meta lens 100 includes a first meta lens ML1 and a second meta lens ML2, and the first meta lens ML1 and the second meta lens ML2 are provided in a form separated from each other. may be Hereinafter, the provision of the first meta-lens ML1 on one surface of the spacer 101 and the provision of the second meta-lens ML2 on the other surface will be described as an example, but the embodiment is not limited thereto.

The first meta-lens ML1 may include an arrangement of a plurality of first nanostructures NS1 having a shape dimension smaller than an operating wavelength and having a width that varies depending on positions. The second meta-lens ML2 may have a shape smaller than the operating wavelength and may include an arrangement of a plurality of second nanostructures NS2 whose width varies depending on positions.

In this way, the plurality of first nanostructures NS1 have a first shape distribution and form a first meta lens ML1, and the plurality of second nanostructures NS2 have a second shape distribution and form a second meta lens (ML1). ML2). The first shape distribution and the second shape distribution may be determined according to the phase delay functions φ ₁ (r) and φ ₂ (r) intended to be represented by the first meta-lens ML1 and the second meta-lens ML2. The phase delay functions φ ₁ (r) and φ ₂ (r) can be determined in consideration of the optical performance to be implemented by the first meta-lens ML1, the second meta-lens ML2, and the meta-lens 100 composed of a combination thereof. can

For example, the first meta-lens ML1 has a first shape of the plurality of first nanostructures NS1 to have a predetermined phase delay function φ ₁ (r) representing positive refractive power. distribution can be determined. For example, the second meta-lens ML2 has a second shape of the plurality of second nanostructures NS2 to have a predetermined phase delay function φ ₂ (r) representing negative refractive power. distribution can be determined.

The first nanostructure NS1 has a width W1 and a height H1, and these values may vary depending on the position of the first nanostructure NS1. The second nanostructure NS2 has a width W2 and a height H2, and these values may vary depending on the position of the second nanostructure NS2.

Although the heights of the first nanostructures NS1 and the second nanostructures NS2 are shown to be the same, they are not limited thereto and may vary according to positions. The plurality of first nanostructures NS1 may all have the same height, and the plurality of second nanostructures NS2 may all have the same height.

Meanwhile, the first meta-lens ML1 may further include a first surrounding material EN1 surrounding the first nanostructure NS1. The second meta-lens ML2 may further include a second surrounding material EN2 surrounding the second nanostructure NS2.

Each of the first and second nanostructures NS1 and NS2 may have a refractive index higher or lower than that of the first and second surrounding materials EN1 122 by 0.5 or more. That is, the difference in refractive index between the first surrounding material EN1 and the first nanostructure NS1 may be 0.5 or more, and the difference in refractive index between the second surrounding material EN2 and the second nanostructure NS2 may be 0.5 or more.

For example, the first nanostructure NS1 is formed of a high refractive index material, the first peripheral material EN1 is formed of a low refractive index material, or the first nanostructure NS1 is formed of a low refractive index material, and the first nanostructure NS1 is formed of a low refractive index material. The surrounding material EN1 may be formed of a high refractive index material. In addition, the second nanostructure NS2 is formed of a high refractive index material, and the second peripheral material EN2 is formed of a low refractive index material, or the second nanostructure NS2 is formed of a low refractive index material and the second peripheral material EN2 is formed of a low refractive index material. (EN2) may be formed of a high refractive index material.

As such, two of the first nanostructure (NS1), the second nanostructure (NS2), the first surrounding material (EN1), and the second surrounding material (EN2) are formed of a high refractive index material, and the other two are formed of a low refractive index material. can be formed as

In this case, the high refractive index material may include, for example, c-Si, p-Si, a-Si, III-V compound semiconductors (GaP, GaN, GaAs, etc.), SiC, TiO ₂ , TiSiOx, SiN, and the like. In addition, the low refractive index material may include, for example, polymer materials such as SU-8 and PMMA, SiO ₂ , SOG, or air.

The spacer 101 supports the first meta-lens ML1 and the second meta-lens ML2, and the difference in refractive index between the spacer 101 and the first nanostructure NS1 and the second nanostructure NS2 is an example. For example, it may be 0.5 or more. The refractive index of the first nanostructure NS1 and/or the second nanostructure NS2 may be higher or lower than that of the spacer 101 .

The spacer 101 may be formed of a relatively low refractive index material other than air. The spacer 101 may be formed of the same material as the first surrounding material EN1 and/or the second surrounding material EN2 or may be formed of a different material. The spacer 101 is a transparent substrate with respect to the operating wavelength of the meta lens 100, for example, any one of glass (fused silica, BK7, etc.), quartz, polymer (PMMA, SU-8, etc.) and plastic. It may be made of one or may be a semiconductor substrate.

The thickness of the spacer 101 may be determined to have a set distance d between the first meta-lens 100 and the second meta-lens 100 .

In the meta-lens 100 according to the present embodiment, the spacer 101 may correspond to a substrate on which the first meta-lens ML1 and the second meta-lens ML2 are formed on both surfaces, respectively.

Meanwhile, in the first meta-lens ML1 and the second meta-lens ML2, the first and second nanostructures NS1 and NS2 are formed on the meta-atom forming the meta-lens 100. may apply. That is, the meta-lens 100 according to the embodiment may be formed of an array of meta-elements having a width smaller than the operating wavelength. Meta elements can be arranged on either a hexagonal lattice or a rectangular lattice. The interval of the lattice of meta elements may be, for example, about 2/3 or less of the minimum wavelength of imaging light. Also, the height of the meta elements may be equal to or greater than about 1/2 of the minimum wavelength of imaging light.

In order to implement such a meta-element, the first and second nanostructures NS1 and NS2 are, as described above, a high refractive material having a higher refractive index or a lower refractive index material than the first and second surrounding materials EN1 and EN2. can include In addition, cross-sections of the first and second nanostructures NS1 and NS2 may have various shapes such as symmetrical shapes such as circular and square or asymmetrical shapes such as elliptical, rectangular, and L-shaped, cross-shaped, or two or more separate sub-sections. -May have a nanostructured structure. Also, the first and second nanostructures NS1 and NS2 may have a length of about 1/2 or more, for example, about 8 times or less of the minimum wavelength of imaging light.

That is, the first meta-lens ML1 may include a plurality of first nanostructures NS1 having a first shape distribution so as to implement the phase delay function φ ₁ (r), and the second meta-lens ML2 may include a plurality of second nanostructures NS2 having a second shape distribution to implement a phase delay function φ ₂ (r).

The first nanostructure NS1 and the second nanostructure NS2 are sub-wavelengths smaller than the operating wavelengths of the first meta-lens ML1 and the second meta-lens ML2, that is, the shortest wavelength among a plurality of spaced apart wavelength bands. It can have a shape dimension of a wavelength. The operating wavelength band may be, for example, a visible light band. The heights of the first nanostructure NS1 and the second nanostructure NS2 are the operating wavelengths of the first meta-lens ML1 and the second meta-lens ML2, that is, the shortest wavelength (λ) among a plurality of spaced apart wavelength bands. _m ) can be greater than The height range may be, for example, 0.5 to 6 times (0.5λ _m to 6.0λ _m , etc.) of the wavelength (λ _m ).

Meanwhile, the surfaces of the first and second surrounding materials EN1 and EN2 are flat to have the same thickness as the first nanostructure NS1 and the second nanostructure NS2, as exemplarily shown in FIG. 5 . It may be formed, however, the embodiment is not limited thereto. For example, the first surrounding material EN1 and the second surrounding material EN2 may be formed to completely cover the first nanostructure NS1 and the second nanostructure NS2. In this case, the first surrounding material EN2 may be formed. The surfaces of (EN1) and the second surrounding material (EN2) may be formed flat or provided to have a curved shape. For example, the first meta-lens ML1 exhibits positive refractive power, the surface of the first surrounding material EN1 may have a convex shape, and the second meta-lens ML2 exhibits negative refractive power. In this regard, the surface of the second surrounding material EN2 may have a concave shape. Also, one of the surfaces of the first and second surrounding materials EN1 and EN2 may be a concave or convex curved surface, and the other surface may be flat.

6 is a cross-sectional view schematically showing another configuration example of the meta lens 100 applied to the lens assemblies 20 and 120 according to various embodiments described above.

Referring to FIG. 6 , in the meta-lens 100 according to the embodiment, the first meta-lens ML1 and the second meta-lens ML2 may be formed on each of the support layers 101a and 101b, for example, a substrate. In addition, the rear surface of the surface of the first meta-lens ML1 on which the first nanostructure NS1 is disposed and the rear surface of the surface of the second meta-lens ML2 on which the second nanostructure NS2 is disposed may be bonded to each other. there is. The support layers 101a and 101b on which the first meta-lens ML1 and the second meta-lens ML2 are respectively formed may be formed of a relatively low refractive index material other than air, like the spacer 101 in FIG. 5 . there is. The support layer 101a or 101b may be formed of the same material as the first surrounding material EN1 and/or the second surrounding material EN2 or may be formed of a different material. The supporting layers 101a and 101b are substrates that are transparent to the operating wavelength of the meta lens 100, for example, among glass (fused silica, BK7, etc.), quartz, polymer (PMMA, SU-8, etc.) and plastic. It may be made of any one of materials, and may be a semiconductor substrate.

At this time, the sum of the thickness of the support layer 101a on which the first meta-lens ML1 is formed and the thickness of the support layer 101b on which the second meta-lens ML2 is formed is, for example, the first meta-lens ML1 in FIG. 5 . It may be determined to have a set distance d between the and the second meta-lens ML2, that is, the thickness of the spacer 101.

7 is a cross-sectional view schematically showing another configuration example of the meta lens 100 applied to the lens assemblies 20 and 120 according to various embodiments described above.

Referring to FIG. 7 , in the meta-lens 100 according to the embodiment, for example, the first nanostructure NS1 of the first meta-lens ML1 is formed on the support layer 102, and the first meta-lens A first peripheral material EN1 surrounding the first nanostructure NS1 of ML1 is formed, a spacer 101 is formed on the first meta lens ML1, and a second peripheral material EN1 is formed on the spacer 101. The second nanostructure NS2 of the meta lens ML2 and the second surrounding material EN2 surrounding the second nanostructure NS2 may be formed. At this time, the thickness of the spacer 101 from the top of the first nanostructure NS1 to the second nanostructure NS2 satisfies the set distance d between the first metalens ML1 and the second metalens ML2. can be formed Here, instead of the spacer 101 , for example, the first surrounding material EN1 may be formed to cover the first nanostructure NS1. Even in this case, the thickness at which the first surrounding material EN1 covers the first nanostructure NS1, that is, the thickness from the upper end of the first nanostructure NS1 to the second nanostructure NS2 is the first meta lens. It may be formed to satisfy the set distance d between (ML1) and the second meta-lens (ML2).

5 to 7 show an example in which the first nanostructure NS1 of the first meta-lens ML1 and the second nanostructure NS2 of the second meta-lens ML2 are arranged in a single layer, respectively. Examples are not limited thereto. For example, at least one of the first nanostructure NS1 of the first meta-lens ML1 and the second nanostructure NS2 of the second meta-lens ML2 has a two-layer structure or a multi-layer structure of three or more layers. may be arranged.

As described above, the lens assembly 20 or 120 according to the embodiment and the imaging device 10 or 110 including the lens assembly include at least one meta lens 100, for example, the first meta lens ML1. , and a second meta-lens ML2, and each of the first meta-lens ML1 and the second meta-lens ML2 is provided to implement a predetermined phase profile. Hereinafter, an exemplary structure of the meta lens ML applicable to the first meta lens ML1 or the second meta lens ML2 will be described with reference to FIGS. 8A to 10 .

8A is a plan view showing a schematic structure of a meta lens ML applied to a lens assembly 20 or 120 according to an embodiment. FIG. 8B exemplarily shows a phase profile implemented for each area of FIG. 8A. The meta lens ML of FIG. 8A may correspond to a plan view of the first meta lens ML1 or the second meta lens ML2 described above.

Referring to FIGS. 8A and 8B , the meta lens ML according to the embodiment includes a plurality of nanostructures NS to exhibit a predetermined phase delay profile with respect to incident light. The nanostructures NS may be disposed on the supporting layer SP. The nanostructure NS may correspond to the first nanostructure NS1 of the first meta-lens ML1 and the second nanostructure NS2 of the second meta-lens ML2 shown in FIGS. 5 to 7 . can The support layer SP may correspond to the spacer 101 shown in FIG. 5 , the support layers 101a and 101b shown in FIG. 6 , and the support layer 102 or spacer 101 shown in FIG. 7 . The nanostructure NS may have a shape dimension smaller than the central wavelength λ ₀ of the operating wavelength band. The nanostructure NS may have a shape dimension of a sub-wavelength smaller than a minimum wavelength λ _m of an operating wavelength band. The operating wavelength band may be a visible light band. The nanostructure NS may have a refractive index different from that of the support layer SP and other surrounding materials. The meta lens ML may implement various phase profiles for incident light according to the arrangement of the nanostructures NS, and may be applied as the first meta lens ML1 and the second meta lens ML2 as described above. .

The meta lens ML includes a plurality of phase modulation regions R _k including a plurality of nanostructures NS whose shape, size, and arrangement are determined according to design conditions, and the plurality of phase modulation regions R _k are It can be arranged in the form of concentric circles, so as to exhibit refractive power serving as a lens.

The plurality of phase modulation regions (R _k ) are disposed along the radial direction (R) from the center (C) of the meta lens (ML), and the width (W _K ) of the plurality of phase modulation regions (R _k ) is far from the center. The smaller it gets, the smaller it can be. Each of the plurality of phase modulation regions R _k is a region representing a phase modulation pattern within a predetermined range. A plurality of phase modulation regions (R _k ) are sequentially arranged along the radial direction (R) from the center (C) of the meta lens (ML), a first region (R ₁ ), a second region (R ₂ ), . ..Including the Nth region (R _N ) and the like. As shown, the first region R ₁ may be circular, and the second region R ₂ to N th region R _N may be annular regions. The first region R ₁ to the Nth region R _N are regions representing a phase delay within a predetermined range, and the phase modulation range may be, for example, 2π. However, this is exemplary and is not limited thereto. The total number of phase modulation regions (N) and the widths (W ₁ , ...W _k , ... W _N ) of each region may be determined according to refractive power (focal length) and lens diameter.

The distribution of the number and width of the phase modulation region (R _k ) is related to the effective diameter of the meta lens (ML) and the size (absolute value) of the refractive power, and the sign of the refractive power is determined according to a rule within each region (R _k ). can be determined For example, the larger the refractive power, the narrower width area (R _k ) can be used more, and the array of rules in which the size of the nanostructure (NS) decreases along the radial direction in each area (R _k ) A positive refractive power can be implemented by a decreasing arrangement), and a negative refractive power can be implemented by a rule arrangement in which the size of the nanostructures NS increases along the radial direction (a phase increasing arrangement). negative refractive power) can be implemented.

9 and 10 show exemplary cross-sectional views of the meta lens ML of FIG. 8 .

The meta lens ML may include a support layer SP and a plurality of nanostructures NS disposed on the support layer SP. A surrounding material EN made of a material having a different refractive index from the nanostructure NS may be formed between the plurality of nanostructures NS. Unlike the illustration, the surrounding material EN may be formed at a height higher than the nanostructure NS, that is, to cover the top of the nanostructure NS. The nanostructures (NS) may be arranged in a single layer as shown in FIG. 9, or as two layers as in FIG. 10, or as three or more layers.

The supporting layer (SP) has a property of being transparent to light in the operating wavelength band of the meta lens (ML), and is made of glass (fused silica, BK7, etc.), quartz, polymer (PMMA, SU-8, etc.) and other transparent plastics. Any one of them can be made.

The nanostructure NS is made of a material having a refractive index difference from surrounding materials such as the surrounding material EN and the support layer SP. For example, the nanostructure NS may have a high refractive index with a difference of 0.5 or more from the refractive index of the surrounding materials EN, or a low refractive index with a difference of 0.5 or more from the refractive index of the surrounding materials. The refractive index difference may be 0.5 or less, for example, 0.2 or more and 0.5 or less.

When the nanostructure (NS) is made of a material having a higher refractive index than the surrounding material (EN), the nanostructure (NS) is c-Si, p-Si, a-Si, III-V compound semiconductor (GaP, GaN, GaAs, etc. ), SiC, TiO ₂ , TiSiOx, and SiN, and the low refractive index surrounding material (EN) may include a polymer material such as SU-8 or PMMA, SiO ₂ , SOG, or air.

When the nanostructure (NS) is made of a material having a lower refractive index than the surrounding material (EN), the nanostructure (NS) may include at least one of SiO ₂ and air, and the high refractive index surrounding material (EN) is c- At least one of Si, p-Si, a-Si, III-V compound semiconductor (GaP, GaN, GaAs, etc.), SiC, TiO ₂ , TiSiOx, and SiN may be included.

The nanostructure (NS) is the operating wavelength of the imaging device 10 (110) to which the lens assembly 20 (120) according to the various embodiments described above is applied and an electronic device including the same, that is, the imaging device 10 (110). ) may have a shape dimension smaller than the minimum wavelength (λ _m ) of the imaging light formed at For example, the width of the nanostructure NS may be 1/2 or more and 2/3 or less of the minimum wavelength (λ _m ). The height of the nanostructure NS may be in the range of 0.5λ _m to 8λ _m .

The nanostructure NS may have a cylindrical shape, and other shapes such as various polygonal columns and elliptical columns. For example, the cross section of the nanostructure (NS) may have various shapes such as a symmetrical shape such as a circle or a square or an asymmetrical shape such as an elliptical shape, a rectangular shape, or an L shape, and may have a cross shape or a structure of two or more separate sub-nanostructures. may be

In the lens assembly 20 or 120 according to the embodiment, the first meta-lens ML1 may have a meta-lens ML structure as described with reference to FIGS. 8A to 10 , and the first meta-lens ML1 The first shape distribution of the plurality of first nanostructures NS1 in each phase modulation region R _{k of} ) is, for example, a predetermined phase delay function (φ ₁ ) representing positive refractive power. (r)) can be determined to have. In addition, the second meta-lens ML2 may have a meta-lens ML structure as described with reference to FIGS. 8A to 10 , and may have a plurality of phase modulation regions R _k of the second meta-lens ML2 . The second shape distribution of the second nanostructures NS2 of may be determined to have, for example, a predetermined phase delay function φ ₂ (r) representing negative refractive power.

Hereinafter, a design example of the lens assembly according to the embodiment will be described with an example of an optical configuration of the lens assembly 20 shown in FIG. 2 .

Table 1/Table 2, Table 3/Table 4, and Table 5/Table 6 exemplarily show design data of the lens assembly 20 according to the embodiment. 11 shows the focusing of light according to the incident direction when the lens assembly 20 according to the embodiment is designed according to the design data of Tables 1 to 6. 12 shows Modulus of the OTF (MTF) performance of the lens assembly 20 according to the embodiment when designed as shown in Tables 1 to 6 and FIG. 11 . In FIG. 12, the horizontal axis represents the spatial frequency, and the vertical axis represents the MTF value. In FIG. 12, 'Diff.Limit' indicates Diffraction Limit (diffraction limit) and means a theoretical MTF limit. Also, for example, '2.5000mm - Sagittal' means an image height of 2.5mm, which means the distance from the center of the image sensor.

noodle Radius (mm) Thickness (mm) texture Conic Norm. Radius S1 3.2819 1.5115 A551425 0.2899 0.9824 S2 41.2487 0.0500 65.8977 2.3211

noodle A0 A1 A2 A3 A4 A5 A6 S1 -3.25E-03 8.86E-05 -7.81E-06 5.40E-07 -2.63E-08 -6.16E-10 3.93E-11 S2 -2.00E-02 -1.61E-02 -2.63E-02 7.19E-03 -9.07E-03 9.03E-03 -3.62E-03

noodle Radius (mm) Thickness (mm) texture Conic Norm. Radius S3 2.3126 0.4000 EP700025 -12.7988 0.8268 S4 1.4493 0.8065 -1.6497 0.7429

noodle A0 A1 A2 A3 A4 A5 A6 S1 2.71E-02 -1.16E-03 5.80E-05 -1.91E-06 -1.20E-07 6.33E-09 5.27E-10 S2 -1.53E-03 1.08E-03 -9.02E-05 -3.10E-06 1.84E-06 -1.84E-07 2.94E-09

Radius (mm) Thickness (mm) texture Conic Type Norm. Radius ML1 Infinity 0.6000 SILICA 0.0000 1.0000 One ML2 Infinity 0.0500 0.0000 1.0000 One

Coeff. on ^2 Coeff. on ^4 Coeff. on ^6 Coeff. on ^8 Coeff. on ^10 Coeff. on ^12 Coeff. on ^14 Coeff. on ^16 Coeff. on ^18 Coeff. on ^20 ML1 -226.8228 62.1423 -139.
2577 94.9498 -23.8132 0.2070 0.4804 -6.47
E-01 4.79
E-01 -8.85
E-02 ML2 233.8962 0.8835 20.8284 34.0985 -60.6878 23.0255 6.1855 -4.45
E+00 -3.41
E-01 3.31
E-01

Tables 1 and 2 show examples of design data of the first refractive lens 21, and Tables 3 and 4 show examples of design data of the second refractive lens 25.

In Tables 1 and 3, 'conic' means conic constant, and Norm. Radius means a value obtained by normalizing the radius.

The aspherical surface data for the first to fourth lens surfaces S1, S2, S3, and S4 in Tables 1 to 4 are obtained by applying the aspheric surface expression of the Q-polynomials (Qbfs) method. In Tables 2 and 4, A1, A2, A3, A4, A5, and A6 denote aspheric coefficients of the first to fourth lens surfaces S1, S2, S3, and S4. The first lens surface S1 represents the lens surface 21a located on the entrance ipsilateral side of the first refractive lens 21, and the second lens surface S2 represents the opposite lens surface. The third lens surface S3 represents a lens surface located on the side of the second refractive lens 25 facing the first refractive lens 21, and the fourth lens surface S4 represents the opposite lens surface 25a. .

Tables 1 and 2, and Tables 3 and 4 show examples in which each of the first to fourth lens surfaces S1, S2, S3, and S4 is designed as an aspherical lens surface. As shown in Table 1 and FIG. 11, the first refractive lens 21 may be formed of a low-dispersion material, for example, A551425. As shown in Table 3 and FIG. 11, the second refractive lens 25 may be formed of a high dispersion material, for example EP700025.

Tables 5 and 6 show examples of design data of the first meta-lens ML1 and the second meta-lens ML2. Table 5 shows an example in which the spacer 101 between the first meta-lens ML1 and the second meta-lens ML2 is made of silica and has a distance d of about 0.6000 mm. In Table 6, 'Coeff. on ^ 2i' represents the Ai value in the polynomial expansion (φ) of Equation 1.

The first meta-lens ML1 and the second meta-lens ML2 are provided to add phases to light rays according to the polynomial expansion of Equation 1. In Equation 1, N represents the number of polynomial coefficients. Ai is the polynomial coefficient at the 2i power of the radial distance ρ, and M is the diffraction order. Tables 5 and 6 show examples in which the number of polynomial coefficients is N=10 and the number of diffraction orders is M=1.

In addition, as exemplarily shown in FIG. 11 , the entrance pupil corresponding to the lens aperture of the first refractive lens 21 may be formed to be about 5.06 mm, and the distance from the entrance pupil to the exit pupil of the lens assembly 20 is 5.06 mm. The distance is designed to be about 6.13 mm and the width of the optical element 30 is about 2.71 mm, and the first refractive lens 21, the second refractive lens 25, and the first meta lens (with the data in Tables 1 to 6) When the ML1) and the second meta lens ML2 are designed, the total focal length of the lens assembly 20 may be, for example, about 11.64 mm, and the image plane extends from the central axis to about 2.5 mm. A phase may form.

When the lens assemblies 20 and 120 according to various embodiments as described above are applied, a telephoto camera of various magnifications can be implemented, and a meta lens prepared to serve as a chromatic dispersion compensation based on an optical path difference between wavelengths ( 100), it is possible to overcome the limitations of mounting space and lens material.

13 is a conceptual diagram illustrating an example in which an imaging device including a lens assembly according to an embodiment is applied to a mobile device 1000 as a telephoto camera.

Referring to FIG. 13 , a plurality of cameras 1200 are mounted in the mobile device 1000, and at least one of the plurality of cameras 1200 may be a telephoto camera. For example, the mobile device 1000 may have first to third cameras 1201, 1203, and 1205 on a rear surface, and at least one of the first to third cameras 1201, 1203, and 1205 may be provided. However, for example, the third camera 1205 may be a telephoto camera. One of the first camera 1201 and the second camera 1203 may be, for example, a wide-angle camera, and the other may be, for example, an ultra-wide-angle camera, but the embodiment is not limited thereto. In this case, the third camera 1205 may include any one of the lens assemblies according to various embodiments described above. Also, the first and/or second cameras 1201 and 1203 may include any one of the lens assemblies according to various embodiments described above.

13 shows an example in which triple cameras are provided on the back of the mobile device 1000 and one of the triple cameras is a telephoto camera, but the embodiment is not limited thereto. For example, the mobile device 1000 may include two or more cameras, for example, dual, triple, quad, penta, or more cameras, and one or more of them may be telephoto cameras. In this case, one or more telephoto cameras may include the lens assembly according to the above-described embodiment. In addition, the lens assembly according to the embodiment described above may be applied to the remaining cameras.

14 shows an example of disposing a folded telephoto camera 1210 to which the lens assembly 20 according to the embodiment is applied inside the mobile device 1000. As shown exemplarily in FIG. 13 , the mobile device 1000 includes first to third cameras 1201, 1203, and 1205 on the rear side, and the third camera 1205 is a telephoto camera. In the case of , the folded telephoto camera 1210 may correspond to, for example, the third camera 1205 . Also, the folded telephoto camera 1210 may be the first camera 1201 or the second camera 1203 . When the mobile device 1000 includes four or more cameras, the folded telephoto camera 1210 may correspond to at least one of the four or more cameras. 14 shows an example in which the lens assembly 20 of FIG. 2 is applied, which is exemplary, and any one of the lens assemblies of FIGS. 1, 3, and 4 or a modified example thereof may be applied.

As shown in FIG. 14, a folded optical system may be implemented by applying an optical element that bends an optical path, for example, a prism 30'. The prism 30' may be disposed so that the internal reflection surface forms an angle of about 45 degrees or another inclined angle with the inner bottom of the mobile device 1000. Light reflected from the subject may be incident into the mobile device 1000 through the transparent window 1001 . The transparent window 1001 may be omitted, may be positioned on the same plane as the cover 1000a of the mobile device 1000, or may be protruded or depressed from the cover 1000a.

In addition, the imaging device 10 (110) including the lens assembly 20 (120) according to the embodiment may be applied to various electronic devices requiring a telephoto camera.

15 is a block diagram showing a schematic configuration of an electronic device 2201 according to an embodiment.

Referring to FIG. 15 , in a network environment 2200, an electronic device 2201 communicates with another electronic device 2202 through a first network 2298 (such as a short-distance wireless communication network) or through a second network 2299. It may communicate with another electronic device 2204 and/or server 2208 via (eg, a long-distance wireless communication network). The electronic device 2201 may communicate with the electronic device 2204 through the server 2208 . The electronic device 2201 includes a processor 2220, a memory 2230, an input device 2250, an audio output device 2255, a display device 2260, an audio module 2270, a sensor module 2210, and an interface 2277. ), haptic module 2279, camera module 2280, power management module 2288, battery 2289, communication module 2290, subscriber identification module 2296, and/or antenna module 2297. can In the electronic device 2201, some of these components (such as the display device 2260) may be omitted or other components may be added. Some of these components can be implemented as a single integrated circuit. For example, the fingerprint sensor 2211 of the sensor module 2210, an iris sensor, or an illumination sensor may be implemented by being embedded in the display device 2260 (display, etc.). In addition, the camera module 2280, the haptic module 2279, and the sensor module 2210 may each include a processor 2220 and a part of the memory 2230 by itself.

The processor 2220 may execute software (program 2240, etc.) to control one or a plurality of other components (hardware, software components, etc.) of the electronic device 2201 connected to the processor 2220, and , various data processing or calculations can be performed. As part of data processing or computation, processor 2220 loads commands and/or data received from other components (sensor module 2210, communication module 2290, etc.) into volatile memory 2232 and Commands and/or data stored in 2232 may be processed, and resulting data may be stored in non-volatile memory 2234. The processor 2220 includes a main processor 2221 (central processing unit, application processor, etc.) and a secondary processor 2223 (graphics processing unit, image signal processor, sensor hub processor, communication processor, etc.) can include The auxiliary processor 2223 may use less power than the main processor 2221 and perform specialized functions.

The secondary processor 2223 may take the place of the main processor 2221 while the main processor 2221 is in an inactive state (sleep state), or the main processor 2221 while the main processor 2221 is in an active state (application execution state). Together with the processor 2221, functions and/or states related to some of the components (display device 2260, sensor module 2210, communication module 2290, etc.) of the electronic device 2201 may be controlled. can The auxiliary processor 2223 (image signal processor, communication processor, etc.) may be implemented as a part of other functionally related components (camera module 2280, communication module 2290, etc.).

The memory 2230 may store various data required by components of the electronic device 2201 (processor 2220, sensor module 2276, etc.). Data may include, for example, input data and/or output data for software (such as program 2240) and instructions related thereto. The memory 2230 may include a volatile memory 2232 and/or a non-volatile memory 2234 .

The program 2240 may be stored as software in the memory 2230 and may include an operating system 2242 , middleware 2244 , and/or applications 2246 .

The input device 2250 may receive a command and/or data to be used by a component (such as the processor 2220) of the electronic device 2201 from the outside of the electronic device 2201 (such as a user). The input device 2250 may include a microphone, mouse, keyboard, and/or digital pen (such as a stylus pen).

The sound output device 2255 may output sound signals to the outside of the electronic device 2201 . The audio output device 2255 may include a speaker and/or a receiver. The speaker can be used for general purposes such as multimedia playback or recording playback, and the receiver can be used to receive an incoming call. The receiver may be incorporated as a part of the speaker or implemented as an independent separate device.

The display device 2260 can visually provide information to the outside of the electronic device 2201 . The display device 2260 may include a display, a hologram device, or a projector and a control circuit for controlling the device. The display device 2260 may include a touch circuitry set to sense a touch and/or a sensor circuit (such as a pressure sensor) set to measure the strength of a force generated by a touch.

The audio module 2270 may convert sound into an electrical signal or vice versa. The audio module 2270 obtains sound through the input device 2250, the sound output device 2255, and/or another electronic device connected directly or wirelessly to the electronic device 2201 (such as the electronic device 2102). ) may output sound through a speaker and/or a headphone.

The sensor module 2210 detects an operating state (power, temperature, etc.) of the electronic device 2201 or an external environmental state (user state, etc.), and generates an electrical signal and/or data value corresponding to the detected state. can do. The sensor module 2210 may include a fingerprint sensor 2211, an acceleration sensor 2212, a position sensor 2213, a 3D sensor 2214, and the like, in addition to an iris sensor, a gyro sensor, an air pressure sensor, and a magnetic sensor. , a grip sensor, a proximity sensor, a color sensor, an IR (Infrared) sensor, a biological sensor, a temperature sensor, a humidity sensor, and/or an illuminance sensor.

The 3D sensor 2214 irradiates a predetermined light to an object and analyzes the light reflected from the object to sense the shape and motion of the object. For example, the lens assembly 20 according to the above-described embodiment and the same An imaging device 10 including may be applied.

The interface 2277 may support one or more specified protocols that may be used to directly or wirelessly connect the electronic device 2201 to another electronic device (e.g., the electronic device 2102). The interface 2277 may include a high definition multimedia interface (HDMI), a universal serial bus (USB) interface, an SD card interface, and/or an audio interface.

The connection terminal 2278 may include a connector through which the electronic device 2201 may be physically connected to another electronic device (e.g., the electronic device 2102). The connection terminal 2278 may include an HDMI connector, a USB connector, an SD card connector, and/or an audio connector (such as a headphone connector).

The haptic module 2279 may convert electrical signals into mechanical stimuli (vibration, movement, etc.) or electrical stimuli that the user can perceive through tactile or kinesthetic senses. The haptic module 2279 may include a motor, a piezoelectric element, and/or an electrical stimulation device.

The camera module 2280 may capture still images and moving images. The camera module 2280 may include, for example, lens assemblies, image sensors, image signal processors, and/or flashes. A plurality of camera modules 2280 may be provided, and each camera module 2280 includes, for example, a lens assembly, an image sensor, an image signal processor, and/or a flash, or includes a lens assembly and an image sensor, The image signal processor and/or flash may be commonly applied to the plurality of camera modules 2280. The lens assembly 2310 included in the camera module 2280 may collect light emitted from a subject that is an object of image capture, and the lens assembly 2310 includes the lens assemblies 20, 120 or Structures modified therefrom may be included. An exemplary structure of the camera module 2280 will be described later with reference to FIG. 16 .

The power management module 2288 may manage power supplied to the electronic device 2201 . The power management module 388 may be implemented as part of a Power Management Integrated Circuit (PMIC).

The battery 2289 may supply power to components of the electronic device 2201 . The battery 2289 may include a non-rechargeable primary cell, a rechargeable secondary cell, and/or a fuel cell.

The communication module 2290 establishes a direct (wired) communication channel and / or wireless communication channel between the electronic device 2201 and other electronic devices (electronic device 2102, electronic device 2104, server 2108, etc.), And it can support communication through the established communication channel. The communication module 2290 may include one or more communication processors that operate independently of the processor 2220 (application processor, etc.) and support direct communication and/or wireless communication. The communication module 2290 includes a wireless communication module 2292 (cellular communication module, short-range wireless communication module, GNSS (Global Navigation Satellite System, etc.) communication module) and/or wired communication module 2294 (Local Area Network (LAN) communication). module, power line communication module, etc.). Among these communication modules, the corresponding communication module is a first network 2298 (a local area communication network such as Bluetooth, WiFi Direct, or IrDA (Infrared Data Association)) or a second network 2299 (cellular network, Internet, or computer network (LAN). , WAN, etc.) to communicate with other electronic devices. These various types of communication modules may be integrated into one component (single chip, etc.) or implemented as a plurality of separate components (multiple chips). The wireless communication module 2292 uses the subscriber information (International Mobile Subscriber Identifier (IMSI), etc.) stored in the subscriber identification module 2296 within a communication network such as the first network 2298 and/or the second network 2299. The electronic device 2201 can be identified and authenticated.

The antenna module 2297 may transmit or receive signals and/or power to the outside (other electronic devices, etc.). The antenna may include a radiator made of a conductive pattern formed on a substrate (PCB, etc.). The antenna module 2297 may include one or a plurality of antennas. When a plurality of antennas are included, an antenna suitable for a communication method used in a communication network such as the first network 2298 and/or the second network 2299 is selected from among the plurality of antennas by the communication module 2290. can Signals and/or power may be transmitted or received between the communication module 2290 and other electronic devices through the selected antenna. In addition to the antenna, other parts (RFIC, etc.) may be included as part of the antenna module 2297.

Some of the components are connected to each other through communication methods (bus, GPIO (General Purpose Input and Output), SPI (Serial Peripheral Interface), MIPI (Mobile Industry Processor Interface), etc.) and signal (command, data, etc.) ) are interchangeable.

Commands or data may be transmitted or received between the electronic device 2201 and the external electronic device 2204 through the server 2108 connected to the second network 2299 . The other electronic devices 2202 and 2204 may be the same as the electronic device 2201 or different types of devices. All or part of the operations executed in the electronic device 2201 may be executed in one or more of the other electronic devices 2202 , 2204 , and 2208 . For example, when the electronic device 2201 needs to perform a function or service, it requests one or more other electronic devices to perform some or all of the function or service instead of executing the function or service by itself. can One or more other electronic devices receiving the request may execute an additional function or service related to the request and deliver the result of the execution to the electronic device 2201 . To this end, cloud computing, distributed computing, and/or client-server computing technologies may be used.

FIG. 16 is a block diagram showing a schematic configuration of a camera module 2280 included in the electronic device 2201 of FIG. 15 by way of example.

Referring to FIG. 16, a camera module 2280 includes a lens assembly 2310, a flash 2320, an image sensor 50 and 2330, an image stabilizer 2340, a memory 2350 (buffer memory, etc.), and/or Alternatively, an image signal processor 2360 may be included. The lens assembly 2310 may collect light emitted from a subject, which is an image capturing target, and form a formed image on the image sensor 2330.

The camera module 2280 may further include actuators. For example, the actuator may drive positions of lens elements constituting the lens assembly 2310 for zooming and/or autofocus (AF) and may adjust a separation distance between the lens elements.

The camera module 2280 may include the lens assembly 20 and 120 according to various embodiments described above as the lens assembly 2310, and the camera module 2280 may be a telephoto camera module. In addition, the camera module 2280 may include a plurality of lens assemblies 2310 and a plurality of image sensors 2330 corresponding thereto, and at least one of the plurality of lens assemblies 2310 is suitable for various embodiments described above. lens assemblies 20 and 120 according to the present invention, and thus the camera module 2280 may include at least one telephoto camera module. For example, the plurality of lens assemblies 2310 may include a telephoto lens assembly and a wide-angle and/or ultra-wide-angle lens assembly, to which the lens assemblies 20 and 120 according to various embodiments described above are applied as the telephoto lens assembly. can Some of the plurality of lens assemblies 2310 may have the same lens properties (angle of view, focal length, auto focus, F number, optical zoom, etc.) or different lens properties.

As such, the camera module 2280 may include a telephoto camera module including a telephoto lens assembly, and may further include a wide-angle camera module and/or an ultra-wide-angle camera module. In this case, the camera module 2280 may be, for example, a dual camera, a triple camera, a quad camera, a penta camera, a 360-degree camera, or a spherical camera.

The flash 2320 may emit light used to enhance light emitted or reflected from a subject. The flash 2320 may include one or more light emitting diodes (Red-Green-Blue (RGB) LED, White LED, Infrared LED, Ultraviolet LED, etc.), and/or a Xenon Lamp.

The image sensor 2330 may obtain an image corresponding to the subject by converting light emitted or reflected from the subject and transmitted through the lens assembly 2310 into an electrical signal. The image sensor 2330 may include one or a plurality of sensors selected from among image sensors having different properties, such as an RGB sensor, a black and white (BW) sensor, an IR sensor, or a UV sensor. Each of the sensors included in the image sensor 2330 may be implemented as a Charged Coupled Device (CCD) sensor and/or a Complementary Metal Oxide Semiconductor (CMOS) sensor. As described above, the camera module 2280 may include a plurality of lens assemblies 2310, and correspondingly, a plurality of image sensors 2330 may be provided.

The image stabilizer 2340 moves one or a plurality of lenses or image sensors 2330 included in the lens assembly 2310 in a specific direction in response to movement of the camera module 2280 or the electronic device 2301 including the same. Alternatively, the operation characteristics of the image sensor 2330 may be controlled (adjustment of read-out timing, etc.) so that negative effects caused by motion may be compensated for. The image stabilizer 2340 detects the movement of the camera module 2280 or the electronic device 2301 using a gyro sensor (not shown) or an acceleration sensor (not shown) disposed inside or outside the camera module 2280. can The image stabilizer 2340 may be implemented optically.

The memory 2350 may store some or all data of an image acquired through the image sensor 2330 for a next image processing task. For example, when a plurality of images are acquired at high speed, the acquired original data (Bayer-patterned data, high-resolution data, etc.) is stored in the memory 2350, only low-resolution images are displayed, and then selected (user selection, etc.) It can be used to cause the original data of the image to be passed to the image signal processor 2360. The memory 2350 may be integrated into the memory 2230 of the electronic device 2201 or may be configured as a separate memory operated independently.

The image signal processor 2360 may perform one or more image processes on an image acquired through the image sensor 2330 or image data stored in the memory 2350 . One or more image processing may include depth map generation, 3D modeling, panorama generation, feature point extraction, image synthesis, and/or image compensation (noise reduction, resolution adjustment, brightness adjustment, blurring, sharpening ( sharpening, softening, etc.). The image signal processor 2360 may perform control (exposure time control, read-out timing control, etc.) for elements included in the camera module 2280 (such as the image sensor 2330). Images processed by the image signal processor 2360 are stored again in the memory 2350 for further processing or are stored in the external components of the camera module 2280 (memory 2230, display device 2260, electronic device 2202). , the electronic device 2204, the server 2208, etc.). The image signal processor 2360 may be integrated into the processor 2220 or may be configured as a separate processor that operates independently of the processor 2220. When the image signal processor 2360 is configured as a separate processor from the processor 2220, the image processed by the image signal processor 2360 undergoes additional image processing by the processor 2220, and then displays the display device 2260. can be displayed through

Meanwhile, the electronic device 2201 may include a plurality of camera modules 2280 each having different properties or functions. In this case, at least one of the plurality of camera modules 2280 may be a telephoto camera, and the others may be wide-angle cameras and/or ultra-wide-angle cameras. The plurality of camera modules 2280 may be implemented as a rear camera and/or a front camera.

The camera module 2280 described above may be mounted in various electronic devices. For example, smart phone, wearable device, Internet of Things (IoT) device, home appliance, tablet PC (Personal Computer), PDA (Personal Digital Assistant), PMP (Portable Multimedia Player), navigation , drones, and advanced driver assistance systems (ADAS).

In the above, although the lens assembly according to the embodiment and the imaging device and electronic device including the same have been described with reference to the embodiment shown in the drawings, this is only an example, and those having ordinary knowledge in the art can find various It will be appreciated that other embodiments that are equivalent and modified are possible. Therefore, the disclosed embodiments should be considered from an illustrative rather than a limiting point of view. The scope of rights is shown in the claims rather than the foregoing description, and all differences within an equivalent scope should be construed as being included in the scope of rights.

Reference Numerals 10,110: imaging device 20,120: lens assembly 21: first refractive lens
25: second refractive lens 30: optical element (prism) 50: image sensor
100,ML,ML1,ML2: meta lens 101: spacer
NS,NS1,NS2: Nano structures EN,NE1,EN2: Surrounding materials

Claims (19)

Arranged from the subject side to the upper side,
a first refractive lens; a second refractive lens; And a meta lens disposed between the second refractive lens and the image surface,
The meta lens may include a first meta lens; and a second meta-lens spaced apart from the first meta-lens. The method of claim 1, wherein the first refractive lens has a positive refractive power and is formed of a low dispersion material,
The second refractive lens has a negative refractive power and is formed of a highly dispersed material. The lens assembly of claim 2, wherein the first refractive lens is formed of a plastic material having an Abbe number of 45 or more and 65 or less. The lens assembly of claim 3, wherein the second refractive lens is formed of a plastic material having an Abbe number of 25 or more and 45 or less. The lens assembly of claim 2, wherein the second refractive lens is formed of a plastic material having an Abbe number of 25 or more and 45 or less. The lens assembly of claim 1, wherein the first refractive lens is provided to mainly focus light, and at least one of the second refractive lens and the meta lens is mainly provided to correct chromatic aberration. 7. The lens assembly of claim 6, wherein the meta lens mainly contributes to correcting basic chromatic aberration, and the second refractive lens mainly contributes to correcting secondary chromatic aberration. The lens assembly of claim 1 , further comprising: an optical element that bends in a traveling direction of light between the second refractive lens and the meta lens and between the meta lens and the image surface. 9. The lens assembly of claim 8, wherein the optical element is a prism. The lens assembly of claim 1 , further comprising at least one refracting lens between the meta lens and the image surface to focus light incident at a high incident angle onto the image surface. The lens assembly of claim 1 , further comprising a spacer between the first meta-lens and the second meta-lens. The lens assembly of claim 1 , wherein the first and second meta-lenses include an array of a plurality of nanostructures having a shape dimension smaller than an operating wavelength and having a width varying according to a position. 13. The lens assembly of claim 12, wherein the plurality of nanostructures have a refractive index greater than or equal to 0.5 or lower than surrounding materials. The method of claim 13, wherein the plurality of nanostructures is at least one of c-Si, p-Si, a-Si, III-V compound semiconductor (GaP, GaN, GaAs, etc.), SiC, TiO ₂ , TiSiOx, SiN A lens assembly formed of a material having a higher refractive index than surrounding materials. 14. The lens assembly of claim 13, wherein the plurality of nanostructures are formed of any one of SiO2 and air to have a lower refractive index than surrounding materials. The method of claim 12, wherein at least one of the first and second meta lenses,
Including a plurality of nanostructures and surrounding materials surrounding them,
A lens assembly in which the effective refractive index of the nanostructure is greater than or less than the effective refractive index of surrounding materials. The method of claim 12, wherein at least one of the first and second meta lenses,
A lens assembly in which a plurality of nanostructures and a layer including a surrounding material surrounding them are arranged in a single layer or in two or more layers. lens assembly; and
An image sensor converting an optical image formed by the lens assembly into an electrical signal;
The lens assembly,
Arranged from the subject side to the image side, the first refractive lens; a second refractive lens; and
It includes a meta lens disposed between the second refractive lens and the image surface,
The meta lens,
a first meta lens; and a second meta-lens spaced apart from the first meta-lens. Including; camera module;
The camera module,
a lens assembly arranged from the subject side to the image side, including a first refractive lens, a second refractive lens, and a meta lens disposed between the second refractive lens and the image surface; and
An image sensor converting an optical image formed by the lens assembly into an electrical signal;
The meta lens may include a first meta lens; and a second meta-lens spaced apart from the first meta-lens.

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