CN218158507U

CN218158507U - Optical lens, optical imaging module and electronic equipment

Info

Publication number: CN218158507U
Application number: CN202221309984.8U
Authority: CN
Inventors: 张�林
Original assignee: Beijing Jihao Technology Co Ltd
Current assignee: TIANJIN JIHAO TECHNOLOGY CO LTD
Priority date: 2022-05-25
Filing date: 2022-05-25
Publication date: 2022-12-27
Anticipated expiration: 2032-05-25

Abstract

The present application relates to the field of optics, and in particular, to an optical lens, an optical imaging module, and an electronic device. The optical lens includes a lens for being disposed between a screen and an image plane, the lens having a positive power, an object side surface and an image side surface of the lens being convex along an optical axis, and at least one side surface of the lens being an even-order aspherical surface. According to the optical lens, the miniaturization of the optical lens can be realized under the condition of ensuring the imaging performance, and the cost is reduced.

Description

Optical lens, optical imaging module and electronic equipment

Technical Field

The present application relates to the field of optics, and in particular, to an optical lens, an optical imaging module, and an electronic device.

Background

In recent years, with the rapid development of electronic equipment with a full screen, a screen fingerprint identification device is carried on the electronic equipment, and the technical trend is that especially optical fingerprint identification has good anti-interference capability and identification capability, so that the electronic equipment has a powerful development prospect; however, the existing optical lens for fingerprint identification is generally formed by combining three plastic lenses, and has a complex structure and high manufacturing cost.

The above information disclosed in this background section is only for enhancement of understanding of the background of the disclosure and therefore it may contain information that does not form any part of the prior art nor form prior art that may be taught to a person of ordinary skill in the art.

SUMMERY OF THE UTILITY MODEL

The present disclosure is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

The utility model provides an optical lens, optical imaging module and electronic equipment, it can be in the condition of guaranteeing the imaging performance, simplifies optical lens's structure to reduce cost.

A first aspect of the present invention provides an optical lens, including a lens; the lens is used for being arranged between the screen and the imaging surface; the lens has a positive optical power; an object side surface of the lens is convex along an optical axis of the optical lens, and an image side surface of the lens is convex along the optical axis.

Further, the object side surface and/or the image side surface of the lens are even aspheric surfaces.

Further, the optical lens further comprises a diaphragm, and the diaphragm is used for being arranged between the lens and the screen.

Further, the optical lens further comprises an optical filter, and the optical filter is arranged between the lens and the imaging surface.

Further, the number of the lenses is one.

Further, the optical lens satisfies: TTL/f is more than or equal to 5 and less than or equal to 7;

wherein, TTL is a distance from a surface of a side of the screen facing the lens to an imaging surface of the optical lens on the optical axis, and f is an effective focal length of the optical lens.

Further, the optical lens satisfies: fov is more than or equal to 100 degrees and less than or equal to 120 degrees;

wherein, fov is the angle of view of the optical lens.

Further, the optical lens satisfies: BFL/f is more than or equal to 1.1 and less than or equal to 1.5;

BFL is the distance from the image side surface of the lens to the imaging surface of the optical lens on the optical axis, and f is the effective focal length of the optical lens.

Further, the optical lens satisfies: ND is more than or equal to 1.4 and less than or equal to 1.8;

wherein ND is the refractive index of the lens.

Further, the optical lens satisfies: VD is more than or equal to 20 and less than or equal to 70;

wherein VD is the Abbe number of the lens.

A second aspect of the present invention provides an optical imaging module, including the optical lens and the image sensor as described above; the image sensor is arranged on the image side of the optical lens.

A third aspect of the present invention provides an electronic device, including the optical imaging module and the screen as described above; the screen is arranged on the object side of the optical lens.

Compared with the prior art, the beneficial effects of the utility model are that:

the utility model provides an optical lens is including being used for setting up a slice lens between screen and imaging surface, and this lens has positive focal power, and its object space surface and image space surface all are convex along the optical axis, and at least one side surface of lens is the aspheric surface of even order. According to the optical lens, the miniaturization of the optical lens can be realized under the condition of ensuring the imaging performance, and the cost is reduced.

The application also provides an optical imaging module, which comprises an image sensor and the optical lens, wherein the image sensor is arranged on the image side of the optical lens; the optical imaging module comprises the optical lens, so that the optical imaging module also has the beneficial effect of the optical lens.

The application also provides electronic equipment, which comprises a display screen and the optical imaging module, wherein the display screen is arranged on the object side of the optical lens; the electronic equipment comprises the optical imaging module provided with the optical lens, so that the electronic equipment also has the beneficial effect of the optical lens.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments or the prior art descriptions will be briefly described below, it is obvious that the drawings in the following descriptions are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

Fig. 1 is a diagram illustrating a first example of an electronic apparatus having an optical lens.

Fig. 2 presents MTF curves of the optical lens shown in fig. 1.

Fig. 3 shows astigmatism curves of the optical lens shown in fig. 1.

Fig. 4 shows distortion curves of the optical lens shown in fig. 1.

Fig. 5 is a diagram illustrating a second example of an electronic apparatus having an optical lens.

Fig. 6 presents MTF curves of the optical lens shown in fig. 5.

Fig. 7 shows astigmatism curves of the optical lens shown in fig. 5.

Fig. 8 shows a distortion curve of the optical lens shown in fig. 5.

Fig. 9 is a diagram illustrating a third example of an electronic apparatus having an optical lens.

Fig. 10 presents MTF curves of the optical lens shown in fig. 9.

Fig. 11 shows astigmatism curves of the optical lens shown in fig. 9.

Fig. 12 shows a distortion curve of the optical lens shown in fig. 9.

Reference numerals are as follows:

in fig. 1: 100-screen, stop-diaphragm, 110-lens, 120-optical filter, 130-image sensor;

in fig. 5: 200-screen, stop-diaphragm, 210-lens, 220-optical filter, 230-image sensor;

in fig. 9: 300-screen, stop-diaphragm, 310-lens, 320-filter, 330-image sensor.

Detailed Description

The following detailed description is provided to assist the reader in obtaining a thorough understanding of the methods, devices, and/or systems described herein. However, various alternatives, modifications, and equivalents of the methods, apparatus, and/or systems described herein will be apparent to those skilled in the art in view of this disclosure. For example, the order of operations described herein is merely an example, which is not limited to the order set forth herein, but rather, variations may be made in addition to operations which must occur in a particular order, which will be apparent upon understanding the disclosure of the present application. Moreover, descriptions of features known in the art may be omitted for the sake of clarity and conciseness.

The features described herein may be embodied in different forms and should not be construed as limited to the examples described herein. Rather, the examples described herein have been provided merely to illustrate some of the many possible ways to implement the methods, devices, and/or systems described herein that will be apparent after understanding the disclosure of the present application.

A first aspect of the present application provides an optical lens of one piece type.

The optical lens provided by the application comprises a lens, wherein the lens can be arranged between a screen and an imaging surface (or an image sensor), namely, the surface of one side of the lens, which faces the screen, is the object side surface of the lens, and the surface of one side of the lens, which faces the imaging surface, is the image side surface of the lens.

The lens has an optical power. For example, the lens has a positive optical power.

The object side surface of the lens is convex along the optical axis of the optical lens, and the image side surface of the lens is convex along the optical axis of the optical lens.

It should be noted that, in the description of the shape of the lens, the fact that one surface of the lens is convex when it is along the optical axis means that the paraxial region of the corresponding surface is convex; therefore, even when one surface of the lens is described as convex, an edge portion of the one surface of the lens may be concave or convex.

The lens has an aspheric surface. For example, at least one of the object side surface and the image side surface of the lens is an even-order aspheric surface.

The even-order aspheric surface of the lens can be expressed by equation 1:

wherein Z is the rise of the aspheric surface, C is the paraxial curvature of the aspheric surface, r is the effective radius value of the corresponding surface of the lens, k is the cone coefficient, and a2-a6 are the high order term coefficients of the aspheric surface.

In some embodiments, the optical lens may further comprise a diaphragm arranged to control the amount of light incident on the lens. The diaphragm can set up the object side at lens, and the diaphragm sets up between lens and screen promptly, sets up the diaphragm in this position and can the low power dissipation control light inlet volume, does benefit to and improves the imaging.

In some embodiments, the optical lens may further include a filter, which may be disposed on the image side of the lens, i.e., between the lens and an image sensor as described below. The optical filter is used for intercepting part of the wavelength light, so that the imaging is clearer. For example, the filter is an infrared filter for blocking light of an infrared wavelength.

A second aspect of the present disclosure further relates to an optical imaging module, wherein the optical imaging module includes the optical lens of the first aspect and an image sensor, and the image sensor is disposed on an image side of the optical lens. The image sensor may form an imaging plane. For example, the surface of the photosensitive pixel array of the image sensor may form an imaging plane.

Preferably, the optical imaging module can be applied to one or more of fingerprint identification, heart rate detection and oxyhemoglobin saturation detection.

A third aspect of the present disclosure also relates to an electronic apparatus, wherein the electronic apparatus includes a screen and the optical imaging module as described above, and the screen is disposed on an object side of the optical lens. Here, the electronic device may be a portable or mobile terminal such as a mobile phone, a tablet computer, a game device, and the like. In electronic equipment, the optical imaging module sets up in the below of screen for receive the light beam that carries fingerprint information, optical lens among the optical imaging module is used for leading the incident light beam to image sensor, image sensor converts the light beam into fingerprint signal and obtains the fingerprint image based on the fingerprint signal. In an embodiment, the screen may provide a light source for the finger that illuminates the finger and reflects a light beam carrying the light signal.

In an optical lens, an optical imaging module, and an electronic apparatus according to the present disclosure, the following conditional expressions may be satisfied:

in some embodiments, 5 ≦ TTL/f ≦ 7 is satisfied;

in some embodiments, 100 ≦ fov ≦ 120 is satisfied;

in some embodiments, 1.1 ≦ BFL/f ≦ 1.5 is satisfied;

in some embodiments, 1.4. Ltoreq. ND.ltoreq.1.8;

in some embodiments, VD 70 is satisfied at 20 ≦.

In the above expression, TTL is the distance from the surface of the screen facing the lens to the imaging plane of the optical lens on the optical axis, f is the effective focal length of the optical lens, fov is the field angle of the optical lens, BFL is the distance from the image space surface of the lens to the imaging plane of the optical lens on the optical axis, ND is the refractive index of the lens, and VD is the abbe number of the lens.

According to the above conditional expressions, at least the following technical effects can be achieved:

according to TTL/f 5 ≦ 7 and BFL/f 1.1 ≦ 1.5, miniaturization of the optical lens can be achieved at least while ensuring imaging performance, and for example, the longitudinal size of an optical imaging module using the optical lens or the installation space in electronic equipment can be reduced. In addition, according to the fov of more than or equal to 100 degrees and less than or equal to 120 degrees, the ultra-wide angle of the optical lens can be at least realized, and the imaging range of the optical lens and the fingerprint identification capability are improved. In addition, according to ND being more than or equal to 1.4 and less than or equal to 1.8 and VD being more than or equal to 20 and less than or equal to 70, the central thickness of the optical lens can be effectively controlled at least, the processing difficulty of the lens is reduced, and the chromatic aberration of the imaging lens is favorably eliminated, so that the imaging quality of the optical lens is improved.

It should be noted that, in the embodiment of the present application, the radius of curvature of the lens, the thickness of the lens, the diagonal length (ImgH) of the effective imaging area of the optical lens on the imaging plane, the focal length, the distance (TTL) from the side surface of the screen facing the lens to the imaging plane, and the distance (BFL) from the image side surface of the lens to the imaging plane are all expressed in units of millimeters (mm).

Next, an electronic device according to several examples will be described.

First, an electronic apparatus according to a first example will be described with reference to fig. 1. The electronic device comprises a screen 100 and an optical imaging module, wherein the screen 100 is arranged on the object side of the optical imaging module. The optical imaging module includes an optical lens and an image sensor 130, and the image sensor 130 is disposed on an image side of the optical lens.

The optical lens according to the first example includes a sheet of lens 110.

The lens 110 has a positive optical power; the lens 110 is a biconvex lens, i.e., both the object-side surface and the image-side surface of the lens 110 are convex along the optical axis.

The optical lens further includes a stop disposed between the lens 110 and the screen 100, and an optical filter 120 disposed between the lens 110 and the image sensor 130.

The optical lens may be configured to realize a bright optical system. For example, the F number of the optical lens is 1.8, and the field angle (fov) of the optical lens is 109.5 °

In the optical lens according to the first example, the focal length f of the lens is 0.476mm, the TTL of the optical lens is 2.875mm, the bfl is 0.616mm, the diagonal length ImgH of the effective imaging area of the optical lens on the imaging plane is 1.18mm, the refractive index ND of the lens is 1.49, and the abbe number VD of the lens is 57.4.

TABLE 1

Surface of	Radius of curvature	Thickness (interval)	ND	VD	Coefficient of cone
						1	Unlimited in size	1.2	1.52	64.2
2	Infinite number of elements	1.818
						stop	Infinite number of elements	0.001
3	1.678	0.44	1.49	57.4	0
						4	-0.25	0.09			-23.447
5	Infinite number of elements	0.175	1.52	64.2
						6	Infinite number of elements	0.35

Here, the conic coefficient is a higher-order term coefficient of the above formula.

Where surfaces 1 and 2 represent, for example, the upper and lower surfaces of a screen, respectively, stop represents a diaphragm, surfaces 3 and 4 represent, respectively, the object-side and image-side surfaces of a lens, and surfaces 5 and 6 represent, respectively, the object-side and image-side surfaces of a filter.

Fig. 2 presents MTF curves of the optical lens of the first example; fig. 3 presents astigmatism curves of the optical lens of the first example, and fig. 4 presents distortion curves of the optical lens of the first example; table 1 presents characteristics of lenses of the optical lens according to the first example.

An electronic apparatus according to a second example will be described with reference to fig. 5, the electronic apparatus including a screen 200 and an optical imaging module, the screen 200 being disposed on an object side of the optical imaging module. The optical imaging module includes an optical lens and an image sensor 230, and the image sensor 230 is disposed on an image side of the optical lens.

The optical lens according to the first example includes a sheet of lens 210.

The lens 210 has positive optical power; the lens 210 is a biconvex lens, i.e., both the object-side surface and the image-side surface of the lens 210 are convex along the optical axis.

The optical lens further includes a stop disposed between the lens 210 and the screen 200, and an optical filter 220 disposed between the lens 210 and the image sensor 230.

The optical lens may be configured to realize a bright optical system. For example, the F number of the optical lens is 1.77, and the angle of view (fov) of the optical lens is 109.9 °

In the optical lens according to the first example, the focal length f of the lens is 0.444mm, the TTL of the optical lens is 2.72mm, the bfl is 0.648mm, the diagonal length ImgH of the effective imaging area of the optical lens on the imaging plane is 1.18mm, the refractive index ND of the lens is 1.59, and the abbe number VD of the lens is 29.9.

TABLE 2

Surface of	Radius of curvature	Thickness (interval)	ND	VD	Coefficient of cone
						1	Unlimited in size	1.2	1.52	64.2
2	Unlimited in size	1.818
						stop	Infinite number of elements	0.001
3	2.504	0.438	1.59	29.9	0
						4	-0.275	0.123			-47.409
5	Unlimited in size	0.175	1.52	64.2
						6	Infinite number of elements	0.35

Where surface 1 and surface 2 represent, for example, the upper and lower surfaces of a screen, respectively, stop represents a diaphragm, surface 3 and surface 4 represent, respectively, the object and image surfaces of a lens, and surface 5 and surface 6 represent, respectively, the object and image surfaces of a filter.

Fig. 6 presents MTF curves of the optical lens of the second example; fig. 7 presents astigmatism curves and fig. 8 presents distortion curves of the optical lens of the second example; table 2 presents characteristics of lenses of the optical lens according to the second example.

An electronic apparatus according to a second example will be described with reference to fig. 9, the electronic apparatus including a screen 300 and an optical imaging module, the screen 300 being disposed on an object side of the optical imaging module. The optical imaging module includes an optical lens and an image sensor 330, and the image sensor 330 is disposed on an image side of the optical lens.

The optical lens according to the first example includes a sheet of lens 310.

The lens 310 has positive optical power; the lens 310 is a biconvex lens, i.e., both the object-side surface and the image-side surface of the lens 310 are convex along the optical axis.

The optical lens further includes a stop disposed between the lens 310 and the screen 300, and an optical filter 320 disposed between the lens 310 and the image sensor 330.

The optical lens may be configured to realize a bright optical system. For example, the F number of the optical lens is 1.83, and the angle of view (fov) of the optical lens is 110.5 °

In the optical lens according to the first example, the focal length f of the lens is 0.457mm, TTL of the optical lens is 2.7mm, bfl is 0.635mm, the diagonal length ImgH of the effective imaging region of the optical lens on the imaging plane is 1.18mm, the refractive index ND of the lens is 1.54, and the abbe number VD of the lens is 55.8.

TABLE 3

Surface of	Radius of curvature	Thickness (interval)	ND	VD	Coefficient of cone
						1	Unlimited in size	1.2	1.52	64.2
2	Infinite number of elements	1.615
						stop	Infinite number of elements	0.001
3	2.062	0.44	1.54	55.8	0
						4	-0.263	0.11			-32.77
5	Infinite number of elements	0.175	1.52	64.2
						6	Infinite number of elements	0.35

Fig. 10 presents MTF curves of the optical lens of the third example; fig. 11 presents astigmatism curves of the optical lens of the third example, and fig. 12 presents distortion curves of the optical lens of the third example; table 3 presents characteristics of the lenses of the optical lens according to the third example.

Table 4 presents values of the conditional expressions of the optical lenses according to the first to third examples.

TABLE 4

According to the above examples, it is possible to achieve miniaturization of an optical lens and reduction in cost while ensuring imaging performance.

While the present disclosure includes particular examples, it will be apparent, after understanding the disclosure of the present application, that various changes in form and detail may be made in these examples without departing from the spirit and scope of the claims and their equivalents. The examples described herein are to be considered in a descriptive sense only and not for purposes of limitation. The description of features or aspects in each example will be considered applicable to similar features or aspects in other examples. Suitable results may be achieved if the described techniques were performed in a different order and/or if components in the described systems, architectures, devices, or circuits were combined in a different manner and/or replaced or supplemented by other components or their equivalents. Therefore, the scope of the present disclosure is defined not by the detailed description but by the claims and their equivalents, and all changes within the scope of the claims and their equivalents are to be construed as being included in the present disclosure.

Claims

1. An optical lens is characterized by comprising lenses, wherein the number of the lenses is one;

the lens is used for being arranged between the screen and the imaging surface;

the lens has a positive optical power;

an object side surface of the lens is convex along an optical axis of the optical lens, and an image side surface of the lens is convex along the optical axis.

2. An optical lens according to claim 1, characterized in that the object side surface and/or the image side surface of the lens is an even-aspheric surface.

3. An optical lens according to claim 1, further comprising an optical stop for being disposed between the lens and the screen.

4. An optical lens according to claim 1, further comprising a filter disposed between the lens and the imaging surface.

5. An optical lens according to any one of claims 1 to 4, characterized in that the optical lens satisfies: TTL/f is more than or equal to 5 and less than or equal to 7;

wherein, TTL is the distance from the surface of the screen facing the lens to the imaging plane of the optical lens on the optical axis, and f is the effective focal length of the optical lens.

6. An optical lens according to any one of claims 1 to 4, characterized in that the optical lens satisfies: fov is more than or equal to 100 degrees and less than or equal to 120 degrees;

wherein, fov is the angle of view of the optical lens.

7. An optical lens according to any one of claims 1 to 4, characterized in that the optical lens satisfies: BFL/f is more than or equal to 1.1 and less than or equal to 1.5;

8. An optical lens according to any one of claims 1 to 4, characterized in that the optical lens satisfies: ND is more than or equal to 1.4 and less than or equal to 1.8;

where ND is the refractive index of the lens.

9. An optical lens according to any one of claims 1 to 4, characterized in that the optical lens satisfies: VD is more than or equal to 20 and less than or equal to 70;

wherein VD is the Abbe number of the lens.

10. An optical imaging module comprising the optical lens of any one of claims 1 to 9 and an image sensor;

the image sensor is arranged on the image side of the optical lens.

11. An electronic device comprising the optical imaging module of claim 10 and a screen;

the screen is arranged on the object side of the optical lens.