WO2021168802A1

WO2021168802A1 - Cover lens and imaging device

Info

Publication number: WO2021168802A1
Application number: PCT/CN2020/077215
Authority: WO
Inventors: Daigo Katsuragi
Original assignee: Guangdong Oppo Mobile Telecommunications Corp., Ltd.
Priority date: 2020-02-28
Filing date: 2020-02-28
Publication date: 2021-09-02
Also published as: CN219349242U

Abstract

A cover lens(L1) is provided on a housing(12) of an imaging device(1) so as to cover the inside of the housing(12), and includes a first surface(S1) on the object side and a second surface(S2) on the imaging surface side, at least one of the first surface(S1) and the second surface(S2) being a convex surface or a concave surface so as to take in light from the object side to the imaging surface side.

Description

COVER LENS AND IMAGING DEVICE

FIELD

The present disclosure relates to a cover lens and an imaging device and, more particularly, to a cover lens and an imaging device that are small and enable good optical performance.

BACKGROUND

Conventionally, optical systems composed of, in order from an object side, a front group optical system having a negative refractive power and a rear group optical system having a positive refractive power are well known as imaging optical systems used in imaging devices such as in-vehicle cameras, surveillance cameras, video cameras, and electronic still cameras.

In recent years, portable imaging devices such as mobile phones and digital cameras are being widely used. With the recent miniaturization of imaging devices, imaging lenses mounted on the imaging devices also require downsizing.

Conventionally, in an imaging device, a cover glass may be disposed on the object side of the imaging lens in order to prevent foreign matter from entering the imaging lens while taking in light from the object side.

However, in a conventional imaging device in which a cover glass is arranged on the object side of the imaging lens, the cover glass does not function effectively as an optical system, and thus it is difficult to obtain good optical characteristics with a small configuration.

SUMMARY

The present disclosure aims to solve at least one of the technical problems mentioned above. Accordingly, the present disclosure needs to provide a cover lens and an imaging device.

In accordance with the present disclosure, a cover lens is provided on a housing of an imaging device so as to cover an inside of the housing and the cover lens includes: a first surface on an object side; and a second surface on an imaging surface side, wherein at least one of the first surface and the second surface is a convex surface or a concave surface so as to take in light from the object side to the imaging surface side.

In an example, a through-hole may be provided on the housing and the cover lens may be disposed inside of the through-hole, so as to fill the through-hole.

In an example, a through-hole may be provided on the housing and the cover lens may be disposed inside of the through-hole together with a barrel in a state of being accommodated in the barrel, so as to fill the through-hole.

In an example, a through-hole may be provided on the housing and the cover lens may be disposed on the object side with respect to the through-hole, so as to cover the through-hole.

In an example, a through-hole may be provided on the housing and the cover lens may be disposed on the imaging surface side with respect to the through-hole, so as to cover the through-hole.

In an example, the cover lens and at least one lens which are disposed on the imaging surface side with respect to the cover lens, have an optical axis in common.

In an example, the cover lens may have a positive refractive power.

In an example, the cover lens may have a negative refractive power.

In an example, the first surface may be a flat surface and the second surface may be a convex surface facing the imaging surface side.

In an example, the first surface may be a convex surface facing the object side and the second surface may be a flat surface.

In an example, the first surface may be a convex surface facing the object side and the second surface may be a convex surface facing the imaging surface side.

In an example, the first surface may be a convex surface facing the object side and the second surface may be a concave surface facing the imaging surface side, the second surface having a central radius of curvature larger than a central radius of curvature of the first surface.

In an example, the first surface may be a concave surface facing the object side and the second surface may be a convex surface facing the imaging surface side, the second surface having a central radius of curvature smaller than a central radius of curvature of the first surface.

In an example, the first surface may be a flat surface and the second surface may be a concave surface facing the imaging surface side.

In an example, the first surface may be a concave surface facing the object side and the second surface may be a flat surface.

In an example, the first surface may be a concave surface facing the object side and the second surface may be a concave surface facing the imaging surface side.

In an example, the first surface may be a convex surface facing the object side and the second surface may be a concave surface facing the imaging surface side, the second surface having a central radius of curvature smaller than a central radius of curvature of the first surface.

In an example, the first surface may be a concave surface facing the object side and the second surface may be a convex surface facing the imaging surface side, the second surface having a central radius of curvature larger than a central radius of curvature of the first surface.

In an example, the cover lens may be movable in an optical axis direction.

In accordance with the present disclosure, an imaging device includes a housing, a cover lens provided on the housing and at least one another lens disposed on an imaging surface side with respect to the cover lens in the housing.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other aspects and advantages of embodiments of the present disclosure will become apparent and more readily appreciated from the following descriptions made with reference to the drawings, in which:

FIG. 1 is a configuration diagram of a cover lens according to a first example of the present disclosure;

FIG. 2 is a schematic sectional view of an imaging device provided with the cover lens of FIG. 1;

FIG. 3 is a schematic sectional view of an image device provided with a conventional cover glass;

FIG. 4 is a front view showing a specific example of an imaging device including the cover lens of FIG. 1;

FIG. 5 is a rear view of FIG. 4;

FIG. 6 is a configuration diagram of a cover lens according to a second example of the present disclosure;

FIG. 7 is a configuration diagram of a cover lens according to a third example of the present disclosure;

FIG. 8 is a configuration diagram of a cover lens according to a fourth example of the present disclosure;

FIG. 9 is a view showing a modification of the cover lens;

FIG. 10 is a view showing a modification of the cover lens;

FIG. 11 is a view showing a modification of the cover lens;

FIG. 12 is a view showing a modification of the cover lens;

FIG. 13 is a view showing a modification of the cover lens;

FIG. 14 is a view showing a modification of the cover lens;

FIG. 15 is a view showing a modification of the cover lens;

FIG. 16 is a view showing a modification of the cover lens, and

FIG. 17 is a view showing a modification of the cover lens.

DETAILED DESCRIPTION

Embodiments of the present disclosure will be described in detail and examples of the embodiments will be illustrated in the accompanying drawings. The same or similar elements and elements having same or similar functions are denoted by like reference numerals throughout the descriptions. The embodiments described herein with reference to the drawings are explanatory and aim to illustrate the present disclosure, but shall not be construed to limit the present disclosure.

First, an outline of the present disclosure will be presented. A cover lens to which the present disclosure is applied is configured as shown in FIGS. 1, 6, 7 and 8, for example. In the figures, dash –dot lines represent optical axes of the camera modules.

The cover lens L1 is provided on a housing 12 of an imaging device 1 so as to cover the inside of the housing 12. The imaging device 1 is, for example, a compact digital device such as a mobile phone, a wearable camera and a surveillance camera. The imaging device 1 includes the cover lens L1 and the housing 12. More specifically, as shown in FIG. 2, the imaging device 1 includes a camera module 11 and the housing 12 that houses the camera module 11. As shown in FIGS. 2 and 3, the camera module 11 includes an imaging lens 21, an optical filter 22, and an image sensor 23. The imaging lens 21 includes the cover lens L1 and at least one other lens L2 which is disposed on an imaging surface S side with respect to the cover lens L1 in the housing 12. The cover lens L1 functions as a lens protection filter with respect to the other lens L2.

The cover lens L1 has a first surface S1 on an object side and a second surface S2 on the imaging surface S side. At least one of the first surface S1 and the second surface S2 is a convex surface or a concave surface so as to take in light from the object side to the imaging surface S side. The convex surface and the concave surface may be spherical surfaces or aspheric surfaces.

The cover lens L1 and the other lens L2 have an optical axis in common. The cover lens L1 is, for example, a lens whose position is fixed in the housing 12. The cover lens L1 may be movable in the optical axis direction within the housing 12 by an actuator. At least some of the other lenses L2 may be movable in the optical axis direction within the housing 12 by an actuator. The lenses movable in the optical axis direction can be used during a focusing operation for adjusting the focus of the imaging lens 21 to a subject.

The image sensor 23 is, for example, a solid-state image sensor such as CMOS (Complementary Metal Oxide Semiconductor) or CCD (Charge Coupled Device) . The image sensor 23 has the imaging surface S which is an imaging plane of the imaging lens 21. The image sensor 23 receives light incident from the subject (object side) via the imaging lens 21 and the optical filter 22, photoelectrically converts the light, and outputs an image data obtained by the photoelectric conversion of the light to a subsequent stage.

In order to obtain an imaging device 1 having an imaging lens of a small size and good optical performance, it is necessary to appropriately correct various aberrations by utilizing a limited space in the optical axis direction of the imaging device 1.

Therefore, in the imaging device 1, the cover lens L1 which one of the first surface S1 and the second surface S2 is a convex surface or a concave surface, is disposed on the housing 12 so as to cover the inside of the housing 12.

With this configuration, the imaging device 1 can make an area A in the optical axis direction, which functions effectively as an optical system (see FIG. 2) , be larger than that of a conventional imaging device which includes a cover glass G disposed on an object side of imaging lens L2 (see FIG. 3) . Since the area A of the imaging device 1 is larger than that of the conventional imaging device, various aberrations can be favorably corrected by appropriately adjusting the number of lenses and the refractive power in the area A of the imaging device 1. As a result, good optical characteristics can be obtained even when a configuration is small.

Furthermore, in view of the lens molding, it is preferable that an aspheric lens constituting the imaging lens 21, in particular, an aspheric lens of aspheric shape having an inflection point is formed of plastic material (glass material) . In addition, among the lenses which constitute the imaging lens 21, a lens having a size equal to or smaller than a specific size may be a lens formed of a plastic material, and a lens larger than the specific size may be a lens formed of a glass material. This is because it is difficult to form an aspheric lens or a relatively small lens using a glass material rather than plastic.

[First example]

Next, a specific example in which the present disclosure is applied will be described. First, a first example in which the cover lens L1 shown in FIG. 1 is described in detail will be described.

In the first example, a through-hole 121 is provided on the housing 12 and the cover lens L1 is disposed inside of the through-hole 121 so as to fill the through-hole 121.

In the first example, the cover lens L1 has a negative refractive power. More specifically, the first surface S1 is a plane surface orthogonal to the optical axis direction, and the second surface S2 is a concave surface facing the imaging surface S side.

According to the first example, the cover lens L1 disposed inside of the through-hole 121 which is provided on the housing 12 can make the area in the optical axis direction which functions effectively as an optical system, be larger than that of the conventional imaging device having the cover glass G. As a result, good optical characteristics can be obtained even when a configuration is small. Further, since the cover lens L1 is disposed inside of the through-hole 121 so as not to protrude toward the object side from the housing 12, the size, that is, the thickness of the imaging device 1 in the optical axis direction can be suppressed.

Further, in a conventional configuration having a cover glass G, "vignetting" , in which light from the object incident on the peripheral side of the imaging lens at a large incident angle is blocked by the cover glass G or a lens barrel, may occur. For this reason, in the conventional configuration, it has been difficult to realize a sufficiently wide angle. In contrast, according to the configuration of the first example, a sufficiently wide angle lens in which "vignetting" is sufficiently suppressed can be realized by including a cover lens L1 having a negative refractive power instead of a conventional cover glass.

The cover lens L1 of the first example can be applied to, for example, the mobile phone 10 shown in FIG. 4 and FIG. 5. The mobile phone 10 includes a substantially rectangular housing 12. On a front side of the housing 12, a display unit 101 and a front camera unit 102 which is an example of the camera module 11, are provided (see FIG. 4) . On a back side of the housing 12, a main camera unit 103 which is an example of the camera module 11, and a camera flash 104, are provided (see FIG. 5) .

The display unit 101 is, for example, a touch panel which enables various operations by detecting a state of contact with a surface of the display unit 101. Accordingly, the display unit 101 has a display function of displaying various information and an input function of allowing a user to perform various input operations. The display unit 101 displays various data such as an operation state and an image captured by the front camera unit 102 or the main camera unit 103.

For example, the cover lens L1 may be used as a lens of the main camera unit 103 as shown in FIG. 5. The cover lens L1 may also be used as a lens of the front camera unit 102.

The front camera unit 102 may be disposed on a back of the display unit 101 so as not to be exposed from a front of the housing 12.

Main camera unit 103 may include a plurality of camera modules 11. In this case, the plurality of camera modules 11 may be arranged side by side along the back surface of the housing 12, and one cover lens L1 may be shared between the plurality of camera modules 11. In the case of sharing one cover lens L1 between the plurality of camera modules 11, the surface of the cover lens L1 may be formed in a shape fitting that of each of the plurality of camera modules 11. Alternatively, a cover lens L1 may be provided for each camera module 11.

[Second example]

Next, a second example in which the cover lens L1 shown in FIG. 6 is described in detail will be described.

In the second example, the through-hole 121 is provided on the housing 12 and the cover lens L1 is disposed inside of the through-hole 121 together with a barrel 13 in a state of being accommodated in the barrel 13 so as to fill the through-hole 121. Another lens L2 may be housed in the barrel 13 in addition to the cover lens L1.

Further, in the second example, the cover lens L1 has a negative refractive power, the first surface S1 is a plane surface, and the second surface S2 is a concave surface facing the imaging surface S side.

Similarly to the first example, the cover lens L1 of the second example can be applied to the main camera unit 103 or the front camera unit 102 in the mobile phone 10.

According to the second example, the cover lens L1 being disposed inside of the through-hole 121 together with the barrel 13 in a state of being accommodated in the barrel 13, the through-hole 121 being provided on the housing 12, can make the area in the optical axis direction, the area functioning effectively as an optical system, be larger than that of the conventional imaging device having the cover glass G. As a result, good optical characteristics can be obtained even when a configuration is small. Further, by housing another lens L2 together with the cover lens L1 in the barrel 13, it is possible to avoid aligning the accommodated lenses L1 and L2. Further, if the barrel 13 is formed of a light shielding material, it is possible to prevent the deterioration of the optical characteristics due to the incidence of light from the side surface of the cover lens L1.

[Third example]

Next, a third example in which the cover lens L1 shown in FIG. 7 is described in detail will be described.

In the third example, the through-hole 121 is provided on the housing 12 and the cover lens L1 is disposed on the object side with respect to the through-hole 121 so as to cover the through-hole 121. As in the second example, the cover lens L1 may be housed in the barrel 13.

Further, in the third example, the cover lens L1 has a negative refractive power, the first surface S1 is a plane surface, and the second surface S2 has a concave surface facing the imaging surface S side.

Similarly to the first example, the cover lens L1 of the third example can also be applied to the main camera unit 103 or the front camera unit 102 in the mobile phone 10.

According to the third example, the cover lens L1 being disposed on the object side with respect to the through-hole 121 which is provided on the housing 12 so as to cover the through-hole 121, can make the area in the optical axis direction, the area functioning effectively as an optical system, be larger than that of the conventional imaging device having the cover glass G. As a result, good optical characteristics can be obtained even when a configuration is small.

[Fourth example]

Next, a fourth example in which the cover lens L1 shown in FIG. 8 is described in detail will be described.

In the fourth example, the through-hole is provided on the housing 12 and the cover lens L1 is disposed on the imaging surface S side with respect to the through-hole 121 so as to cover the through-hole 121. As in the second example, the cover lens L1 may be housed in the barrel 13.

In the fourth example, the cover lens L1 has a negative refractive power, the first surface S1 is a flat surface, and the second surface S2 is a concave surface facing the imaging surface S side.

Similarly to the first example, the cover lens L1 of the fourth example can also be applied to the main camera unit 103 or the front camera unit 102 in the mobile phone 10.

According to the fourth example, the cover lens L1 being disposed on the imaging surface S side with respect to the through-hole 121 which is provided on the housing 12 so as to cover the through-hole 121, can make the area in the optical axis direction, the area functioning as an optical system, be larger than that of the conventional imaging device having the cover glass G. As a result, good optical characteristics can be obtained even when a configuration is small. Further, it is also possible to position an optical member such as an optical filter inside the through-hole 121 or on the object side of the through-hole 121 to adjust the optical characteristics.

[Modification]

Next, a modification of the surface shape of the cover lens L1 will be described. The cover lens L1 in which the first surface S1 is a flat surface and the second surface S2 is a concave surface facing the imaging surface S has been described. However, the surface shapes of the first surface S1 and the second surface S2 are not limited to this.

For example, as shown in FIG. 9, the first surface S1 may be a concave surface facing the object side, and the second surface S2 may be a flat surface.

Further, as shown in FIG. 10, the first surface S1 may be a convex surface facing the object side, and the second surface S2 may be a concave surface facing the imaging surface S side, the second surface S2 having a central radius of curvature smaller than a central radius of curvature of the first surface S1.

As shown in FIG. 11, the first surface S1 may be a concave surface facing the object side, and the second surface S2 may be a convex surface facing the imaging surface S side, the second surface S2 having a central radius of curvature larger than a central radius of curvature of the first surface S1.

Further, as shown in FIG. 12, the first surface S1 may be a concave surface facing the object side, and the second surface S2 may be a concave surface facing the imaging surface S side.

Although the cover lens L1 having the surface shape described above has a negative refractive power, the present disclosure can also be applied to the cover lens L1 having a positive refractive power.

In this case, as shown in FIG. 13, the first surface S1 may be a flat surface, and the second surface S2 may be a convex surface facing the imaging surface S side.

Further, as shown in FIG. 14, the first surface S1 may be a convex surface facing the object side, and the second surface S2 may be a flat surface.

As shown in FIG. 15, the first surface S1 may be a convex surface facing the object side, and the second surface S2 may be a concave surface facing the imaging surface S side, the second surface S2 having a central radius of curvature larger than a central radius of curvature of the first surface S1.

As shown in FIG. 16, the first surface S1 may be a concave surface facing the object side, and the second surface S2 may be a convex surface facing the imaging surface S side, the second surface S2 having a central radius of curvature smaller than a central radius of curvature of the first surface S1.

Further, as shown in FIG. 17, the first surface S1 may be a convex surface facing the object side, and the second surface S2 may be a convex surface facing the imaging surface S side.

In the description of embodiments of the present disclosure, it is to be understood that terms such as "central" , "longitudinal" , "transverse" , "length" , "width" , "thickness" , "upper" , "lower" , "front" , "rear" , "back" , "left" , "right" , "vertical" , "horizontal" , "top" , "bottom" , "inner" , "outer" , "clockwise" and "counterclockwise" should be construed to refer to the orientation or the position as described or as shown in the drawings in discussion. These relative terms are only used to simplify the description of the present disclosure, and do not indicate or imply that the device or element referred to must have a particular orientation, or must be constructed or operated in a particular orientation. Thus, these terms cannot be constructed to limit the present disclosure.

In addition, terms such as "first" and "second" are used herein for purposes of description and are not intended to indicate or imply relative importance or significance or to imply the number of indicated technical features. Thus, a feature defined as "first" and "second" may comprise one or more of this feature. In the description of the present disclosure, "a plurality of" means “two or more than two” , unless otherwise specified.

In the description of embodiments of the present disclosure, unless specified or limited otherwise, the terms "mounted" , "connected" , "coupled" and the like are used broadly, and may be, for example, fixed connections, detachable connections, or integral connections; may also be mechanical or electrical connections; may also be direct connections or indirect connections via intervening structures; may also be inner communications of two elements which can be understood by those skilled in the art according to specific situations.

In the embodiments of the present disclosure, unless specified or limited otherwise, a structure in which a first feature is "on" or "below" a second feature may include an embodiment in which the first feature is in direct contact with the second feature, and may also include an embodiment in which the first feature and the second feature are not in direct contact with each other, but are in contact via an additional feature formed therebetween. Furthermore, a first feature "on" , "above" or "on top of" a second feature may include an embodiment in which the first feature is orthogonally or obliquely "on" , "above" or "on top of" the second feature, or just means that the first feature is at a height higher than that of the second feature; while a first feature "below" , "under" or "on bottom of" a second feature may include an embodiment in which the first feature is orthogonally or obliquely "below" , "under" or "on bottom of" the second feature, or just means that the first feature is at a height lower than that of the second feature.

Various embodiments and examples are provided in the above description to implement different structures of the present disclosure. In order to simplify the present disclosure, certain elements and settings are described in the above. However, these elements and settings are only by way of example and are not intended to limit the present disclosure. In addition, reference numbers and/or reference letters may be repeated in different examples in the present disclosure. This repetition is for the purpose of simplification and clarity and does not refer to relations between different embodiments and/or settings. Furthermore, examples of different processes and materials are provided in the present disclosure. However, it would be appreciated by those skilled in the art that other processes and/or materials may also be applied.

Reference throughout this specification to "an embodiment" , "some embodiments" , "an exemplary embodiment" , "an example" , "a specific example" or "some examples" means that a particular feature, structure, material, or characteristics described in connection with the embodiment or example is included in at least one embodiment or example of the present disclosure. Thus, the appearances of the above phrases throughout this specification are not necessarily referring to the same embodiment or example of the present disclosure. Furthermore, the particular features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

Any process or method described in a flow chart or described herein in other ways may be understood to include one or more modules, segments or portions of codes of executable instructions for achieving specific logical functions or steps in the process, and the scope of a preferred embodiment of the present disclosure includes other implementations, in which it should be understood by those skilled in the art that functions may be implemented in a sequence other than the sequences shown or discussed, including in a substantially identical sequence or in an opposite sequence.

The logic and/or step described in other manners herein or shown in the flow chart, for example, a particular sequence table of executable instructions for realizing the logical function, may be specifically achieved in any computer readable medium to be used by the instructions execution system, device or equipment (such as a system based on computers, a system comprising processors or other systems capable of obtaining instructions from the instructions execution system, device and equipment executing the instructions) , or to be used in combination with the instructions execution system, device and equipment. As to the specification, "the computer readable medium" may be any device adaptive for including, storing, communicating, propagating or transferring programs to be used by or in combination with the instruction execution system, device or equipment. More specific examples of the computer readable medium comprise but are not limited to: an electronic connection (an electronic device) with one or more wires, a portable computer enclosure (a magnetic device) , a random access memory (RAM) , a read only memory (ROM) , an erasable programmable read-only memory (EPROM or a flash memory) , an optical fiber device and a portable compact disk read-only memory (CDROM) . In addition, the computer readable medium may even be a paper or other appropriate medium capable of printing programs thereon, this is because, for example, the paper or other appropriate medium may be optically scanned and then edited, decrypted or processed with other appropriate methods when necessary to obtain the programs in an electric manner, and then the programs may be stored in the computer memories.

It should be understood that each part of the present disclosure may be realized by the hardware, software, firmware or their combination. In the above embodiments, a plurality of steps or methods may be realized by the software or firmware stored in the memory and executed by the appropriate instructions execution system. For example, if it is realized by the hardware, likewise in another embodiment, the steps or methods may be realized by one or a combination of the following techniques known in the art: a discrete logic circuit having a logic gate circuit for realizing a logic function of a data signal, an application-specific integrated circuit having an appropriate combination logic gate circuit, a programmable gate array (PGA) , a field programmable gate array (FPGA) , etc.

Those skilled in the art shall understand that all or parts of the steps in the above exemplifying method of the present disclosure may be achieved by commanding the related hardware with programs. The programs may be stored in a computer readable storage medium, and the programs comprise one or a combination of the steps in the method embodiments of the present disclosure when run on a computer.

In addition, each function cell of the embodiments of the present disclosure may be integrated in a processing module, or these cells may be separate physical existence, or two or more cells are integrated in a processing module. The integrated module may be realized in a form of hardware or in a form of software function modules. When the integrated module is realized in a form of software function module and is sold or used as a standalone product, the integrated module may be stored in a computer readable storage medium.

The storage medium mentioned above may be read-only memories, magnetic disks, CD, etc.

Although embodiments of the present disclosure have been shown and described, it would be appreciated by those skilled in the art that the embodiments are explanatory and cannot be construed to limit the present disclosure, and changes, modifications, alternatives and variations can be made in the embodiments without departing from the scope of the present disclosure.

Claims

A cover lens provided on a housing of an imaging device so as to cover an inside of the housing, the cover lens comprising:

a first surface on an object side; and

a second surface on an imaging surface side, wherein

at least one of the first surface and the second surface is a convex surface or a concave surface so as to take in light from the object side to the imaging surface side.
The cover lens according to claim 1, wherein a through-hole is provided on the housing and the cover lens is disposed inside of the through-hole so as to fill the through-hole.
The cover lens according to claim 1, wherein a through-hole is provided on the housing and the cover lens is disposed inside of the through-hole together with a barrel in a state of being accommodated in the barrel so as to fill the through-hole.
The cover lens according to claim 1, wherein a through-hole is provided on the housing and the cover lens is disposed on the object side with respect to the through-hole so as to cover the through-hole.
The cover lens according to claim 1, wherein a through-hole is provided on the housing and the cover lens is disposed on the imaging surface side with respect to the through-hole so as to cover the through-hole.
The cover lens according to claim 1, wherein the cover lens and at least one lens which is disposed on the imaging surface side with respect to the cover lens have an optical axis in common.
The cover lens according to claim 1, wherein the cover lens has a positive refractive power.
The cover lens according to claim 1, wherein the cover lens has a negative refractive power.
The cover lens according to claim 7, wherein the first surface is a flat surface and the second surface is a convex surface facing the imaging surface side.
The cover lens according to claim 7, wherein the first surface is a convex surface facing the object side and the second surface is a flat surface.
The cover lens according to claim 7, wherein the first surface is a convex surface facing the object side and the second surface is a convex surface facing the imaging surface side.
The cover lens according to claim 7, wherein the first surface is a convex surface facing the object side and the second surface is a concave surface facing the imaging surface side, the second surface having a central radius of curvature larger than a central radius of curvature of the first surface.
The cover lens according to claim 7, wherein the first surface is a concave surface facing the object side and the second surface is a convex surface facing the imaging surface side, the second surface having a central radius of curvature smaller than a central radius of curvature of the first surface.
The cover lens according to claim 8, wherein the first surface is a flat surface and the second surface is a concave surface facing the imaging surface side.
The cover lens according to claim 8, wherein the first surface is a concave surface facing the object side and the second surface is a flat surface.
The cover lens according to claim 8, wherein the first surface is a concave surface facing the object side and the second surface is a concave surface facing the imaging surface side.
The cover lens according to claim 8, wherein the first surface is a convex surface facing the object side and the second surface is a concave surface facing the imaging surface side, the second surface having a central radius of curvature smaller than a central radius of curvature of the first surface.
The cover lens according to claim 8, wherein the first surface is a concave surface facing the object side and the second surface is a convex surface facing the imaging surface side, the second surface having a central radius of curvature larger than a central radius of curvature of the first surface.
The cover lens according to any one of claims 1-18, wherein the cover lens is movable in an optical axis direction.
An imaging device comprising:

a housing,

a cover lens according to any one of claims 1-19, and

at least one another lens disposed on an imaging surface side with respect to the cover lens in the housing.