CN112904529A

CN112904529A - Optical lens, lens module and electronic equipment

Info

Publication number: CN112904529A
Application number: CN201911221600.XA
Authority: CN
Inventors: 叶海水; 蔡家豪; 牛亚军
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2019-12-03
Filing date: 2019-12-03
Publication date: 2021-06-04

Abstract

The application provides an optical lens, a lens module and an electronic device, wherein the optical lens comprises a first lens group, an aperture diaphragm and a second lens group, wherein the first lens group has positive focal power and is used for receiving light and converging the light, the first lens group comprises a reflecting element, and the reflecting element is used for reflecting the light so as to transmit the light to the second lens group; the aperture diaphragm is positioned on the object side of the reflecting element; the second lens group comprises a plurality of lenses, is arranged at the image side of the first lens group, and is used for imaging the light rays on a focusing plane. The application provides an optical lens can set up bigger aperture diaphragm to can increase the light ring and the diffraction limit value of camera lens, be favorable to improving the imaging quality of camera lens.

Description

Optical lens, lens module and electronic equipment

Technical Field

The present application relates to the field of optical lenses, and more particularly, to an optical lens, a lens module, and an electronic apparatus.

Background

High power optical zooming is always the development trend of smart phone camera shooting, and is limited by the trend of smart phone lightness and thinness, and the traditional lens module structure cannot meet the requirement of high power optical zooming, so that the periscopic lens moves to the stage of a mobile phone camera, and the possibility of remote zooming is realized.

Fig. 1 is a schematic structural diagram of a conventional periscopic lens module, which includes a rectangular prism 1, a telephoto lens set 2, an infrared filter 3, an electronic photoreceptor 4, and the like along an optical axis S3. The light from the object side enters the prism 1 along the Y direction (i.e. the thickness direction of the mobile phone), is refracted by 90 ° by the total reflection surface of the prism 1, and is focused by the telephoto lens group 2 and filtered by the infrared filter element 3 along the Z direction (i.e. the length direction of the mobile phone), and then is imaged on the electronic photosensitive device 4.

As shown in fig. 1, the aperture stop 5 of the conventional periscopic lens module is usually disposed on the image side of the prism and along the thickness direction of the mobile phone. Because the size of the aperture diaphragm is limited by the thickness of the mobile phone, the current periscopic lens module cannot meet the requirements of consumers on large apertures and high imaging quality.

Disclosure of Invention

The application provides an optical lens, lens module and electronic equipment can set up bigger aperture diaphragm to can increase the light ring and the diffraction limit value of camera lens, be favorable to improving the image quality of camera lens.

In a first aspect, an optical lens is provided, which includes a first lens group, an aperture stop, and a second lens group, where the first lens group has a positive focal power and is configured to receive and converge light, and the first lens group includes a reflective element configured to reflect light to transmit the light to the second lens group; an aperture stop located on an object side of the reflective element; the second lens group comprises a plurality of lenses, is arranged at the image side of the first lens group and is used for imaging light rays on a focusing plane.

This application aperture stop sets up in the thing side of reflective element, that is to say, aperture stop sets up on the light path before the turn, and the plane that aperture stop place at this moment is mutually perpendicular with cell-phone thickness direction, and the thickness of aperture stop can not receive the restriction of cell-phone thickness, makes this application embodiment can set up the aperture stop of bigger size from this.

On this basis, because the size of a plurality of lenses in the second lens group still can receive the restriction of cell-phone thickness, the size of lens can't be set up bigger, consequently, the first lens group of this application has positive focal power, can reflect to the second lens group in after converging the focus with light to be favorable to dwindling the effective path of optics of a plurality of lenses in the second lens group.

The application provides an optical lens can set up the aperture diaphragm of bigger size, and then can obtain bigger entrance pupil diameter, under the certain circumstances of camera lens focus, can obtain littleer light ring F value, can obtain bigger light ring and diffraction limit value promptly to be favorable to improving periscopic optical lens's imaging quality.

In one possible design, the reflective element has positive optical power. The advantage of above setting is, can reduce the quantity that sets up the lens, reduces the complexity of camera lens design to and practice thrift the cost.

In one possible design, the reflective element includes a reflective surface that is any one of spherical, aspherical, or free-form, the reflective surface having positive optical power.

In one possible design, the reflecting element is a prism, the prism includes the reflecting surface, and an incident surface and an exit surface, the incident surface is a spherical surface or an aspherical surface, and the exit surface is a spherical surface or an aspherical surface.

In the embodiment of the application, the reflecting surface, the incident surface and the emergent surface are all curved surfaces and all have certain focal power, and the focal power of the three surfaces is reasonably distributed, so that the whole prism has positive focal power. In addition, the optical power of the reflecting surface and the incident surface can be reasonably distributed to compress the optical width and control the outer diameter of the emergent surface, so that the height of the prism in the thickness direction of the mobile phone can be controlled.

In one possible design, the reflective element is a curved mirror. Compared with the prism, the curved surface reflector only has one reflecting surface without an incident surface and an emergent surface, so that the reduction of the reflection ghost among the surfaces of the optical lens is facilitated, the light transmittance of the lens is improved, and the imaging quality of the lens can be improved. In addition, for the prism, curved surface speculum weight is lighter to can reduce the degree of difficulty that actuator design and manufacturing among the lens module.

In one possible design, the plurality of lenses includes, in order from the object side to the image side, a first lens having negative optical power, a second lens having positive optical power, a third lens having negative optical power, and a fourth lens having positive optical power.

In other embodiments, the first lens, the second lens, the third lens and the fourth lens may also be distributed with optical powers in other manners, which is not limited in this application. For example, the first lens may have a negative optical power, the second lens may have a negative optical power, the third lens may have a positive optical power, and the fourth lens may have a positive optical power.

Optionally, each surface of the first lens, the second lens, the third lens and the fourth lens may be an aspheric surface, and the aspheric surface has a better curvature radius characteristic, and has the advantages of improving distortion aberration and astigmatic aberration, so that the imaging quality can be improved. In other embodiments, each lens may have another surface type as needed, which is not limited in the present application.

The first lens element, the second lens element, the third lens element and the fourth lens element may be made of the same material or different materials, which is not limited in the present application.

For example, the first lens, the second lens, the third lens and the fourth lens may be made of the same material, so that the optical properties of the respective lenses are close to each other, thereby helping to reduce the difficulty of engineering implementation of the optical lens.

Alternatively, the material of each lens may be any one of resin, plastic, glass, and the like.

In one possible embodiment, the first mirror group further comprises a fifth lens, which is located on the object side of the reflective element and has a positive or negative optical power. The first mirror group comprises a fifth lens and a reflecting element, the first mirror group has positive focal power, namely, the total focal power of the fifth lens and the prism is positive, and under the combined action of the fifth lens and the reflecting element, the incident light can be converged and reflected into the second mirror group.

In one possible embodiment, an aperture stop is arranged on the object side of the fifth lens, or an aperture stop is arranged between the fifth lens and the reflective element, or an aperture stop is arranged on the fifth lens.

In one possible design, the fifth lens and the reflective element are connected by an optical glue.

In one possible design, a highly reflective film layer is disposed on the reflective surface. In order to improve the imaging quality, a high-reflection film layer can be arranged on the reflecting surface. Specifically, the reflecting surface can adopt a high-reflection film layer design, the thickness of the film layer is usually above the layer, and the reflecting surface can be expanded to more film layers according to the reflectivity requirement defined by the system design.

Alternatively, the reflectivity of the reflective surface may be required to be above 95% within the visible bandwidth, without reflectivity constraints for ultraviolet and near infrared.

Alternatively, in consideration of the near infrared and ultraviolet light cut-off capability of the optical system, the film layer of the reflecting surface can be designed to have the characteristics of high reflection of visible light (380 nm-780 nm) and high transmission of ultraviolet wave band (380nm below) and near infrared wave band (780nnm above), so that the entering of non-visible light into the image sensor can be reduced, and the imaging quality can be improved.

In one possible design, the reflective element is composed of a resin material. The reflecting element is made of resin materials, so that the weight of the reflecting element can be controlled, and the difficulty in designing and manufacturing the actuator in the lens module is reduced. In addition, according to the process characteristics of injection molding, the resin material can realize the surface shapes of a spherical surface, an aspherical surface, a free-form surface and the like with high precision requirements, and can meet the surface shape requirements of the application on the reflecting element.

In one possible design, the optical lens further includes an infrared filter disposed on the image side of the second lens group. The infrared filter is used to cut off and filter infrared rays, and may be, for example, a white glass filter or a blue glass filter.

In one possible design, the optical lens further includes a lens barrel for disposing the plurality of lenses.

In a second aspect, a lens module is provided, which includes an image sensor and the optical lens provided in any one of the designs of the first aspect, and the optical lens is used for imaging light to the image sensor.

Alternatively, the image sensor 200 may be a complementary metal-oxide semiconductor (CMOS) image sensor or a Charge Coupled Device (CCD) image sensor.

Alternatively, the lens module may further include a holder, an auto focus driving assembly, a circuit board, a connector, and peripheral electronic components.

In a third aspect, an electronic device is provided, and the electronic device includes the lens module provided in the second aspect.

Optionally, the electronic device further comprises a shell and a display screen, the display screen is installed on the shell, an accommodating space is formed in the shell, the lens module can be installed in the accommodating space, and the display screen can be used for displaying pictures or videos shot by the lens module.

Alternatively, the housing may be a metal housing, such as a metal such as magnesium alloy, stainless steel, etc. In addition, the housing may be a plastic housing, a glass housing, a ceramic housing, or the like, but is not limited thereto.

Alternatively, the display screen may be a Light Emitting Diode (LED) display screen, a Liquid Crystal Display (LCD) display screen, an organic light-emitting diode (OLED) display screen, or the like, but is not limited thereto.

Optionally, other devices, such as, but not limited to, a battery, a flashlight, a fingerprint recognition module, an earpiece, a circuit board, a sensor, etc., may also be included in the housing.

Alternatively, the electronic device may be a terminal device with a camera function, such as a mobile phone, a tablet computer, a laptop computer, a video camera, a video recorder, a camera, a smart robot, or other devices with camera function.

Drawings

Fig. 1 is a schematic structural diagram of a conventional periscopic lens module.

Fig. 2 is a schematic structural diagram of an example of an optical lens provided in an embodiment of the present application.

Fig. 3 is a schematic structural diagram of another example of an optical lens provided in the embodiment of the present application.

Fig. 4 is a schematic structural diagram of another example of an optical lens provided in an embodiment of the present application.

Fig. 5 is a schematic structural diagram of another example of an optical lens provided in an embodiment of the present application.

Fig. 6 is a schematic structural diagram of a lens module according to an embodiment of the present application.

Fig. 7 is a schematic structural diagram of an electronic device provided in an embodiment of the present application.

Detailed Description

The technical solution in the present application will be described below with reference to the accompanying drawings. It is to be understood that the embodiments described are only a few embodiments of the present application and not all embodiments.

In the following, the terms "first", "second", etc. are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first," "second," etc. may explicitly or implicitly include one or more of that feature.

It should be noted that the same reference numerals are used to denote the same components or parts in the embodiments of the present application, and for the same parts in the embodiments of the present application, only one of the parts or parts may be given the reference numeral, and it should be understood that the reference numerals are also applicable to the other same parts or parts.

For convenience of understanding, technical terms related to the present application are explained and described below.

Lens: the device is a component which makes the scenery light pass through the lens by utilizing the refraction principle of the lens and forms a clear image on a focusing plane.

Optical axis: the chief ray of the central field of view is referenced as the direction in which the optical system conducts the ray. For a symmetric transmission system, it is generally coincident with the optical system rotation centerline. For off-axis and reflective systems, the optical axis will also appear as a polyline.

Object-side, image-side: the surface of the lens close to the object side can be called an object side surface; the side of the lens on which the image of the object is located is the image side, and the surface of the lens close to the image side can be referred to as the image side surface.

Focal length (focal length): also referred to as focal length, is a measure of the concentration or divergence of light in an optical system, and refers to the distance from the optical center of a lens or a lens group to the focal point when an infinite scene is focused on a focal plane through the lens or the lens group, and can also be understood as the perpendicular distance from the optical center of the lens or the lens group to the focal plane. From a practical point of view it can be understood as the distance of the lens center to the imaging plane.

Optical power (focal power): equal to the difference between the convergence of the image-side beam and the convergence of the object-side beam, and is characteristic of the ability of the optical system to deflect light. Common letter of focal power

Express, refractive spherical power

Wherein n 'is the image-side refractive index, n is the object-side refractive index, r is the spherical radius, f' is the image focal length, and f is the object focal length. The power is generally expressed as the inverse of the image focal length (approximately, the refractive index of air is considered to be 1). The above lightThe power equation is generic to any optical system (no paraxial component).

The optical power characterizes the refractive power of the optical system for an incident parallel light beam.

The larger the value of (A), the more the parallel beam is folded;

when, the flexion is convergent;

when this occurs, the flexion is divergent.

When it is, it corresponds to, i.e., plane refraction. At this time, the axially parallel light beams are still axially parallel after being refracted, and the refraction phenomenon does not occur.

Diaphragm (diaphragm): refers to the edge, frame or specially provided perforated barrier of the optical elements in the optical train assembly used to limit the imaging beam size or imaging spatial unit.

Aperture Stop (STO): is the diaphragm that limits the maximum inclination of the marginal ray in the on-axis point image beam, i.e. the diaphragm with the smallest entrance aperture angle.

Entrance pupil: the entrance pupil is the effective aperture that confines the incident beam and is the image of the aperture stop onto the front optical system. The entrance pupil corresponds to the exit pupil, and the conjugate image of the aperture stop in object space is called the "entrance pupil", whose position and diameter represent the position and aperture of the incident light beam.

Aperture (aperture): the device is used for controlling the light quantity of light which penetrates through the lens and enters a light sensing surface in the machine body, and is usually arranged in the lens. The expressed aperture size is expressed in F/number.

Aperture F value: equal to the lens focal length divided by the entrance pupil diameter. Under the condition that the focal length of the lens is not changed, the larger the diameter of the entrance pupil is, the larger the aperture is, the smaller the F value of the aperture is, the more the light incoming quantity is, the brighter the picture is, and the larger the blurring of the main body background is; conversely, the smaller the entrance pupil diameter, the smaller the aperture, the larger the F value of the aperture, the smaller the amount of light entering, the darker the screen, and the sharper the front and rear of the subject.

Total Track Length (TTL): the total length from the lens barrel head to the imaging surface is a major factor in forming the height of the camera.

Diffraction limit (diffraction limit): the method means that an ideal object point is imaged by an optical system, and an ideal image point cannot be obtained due to the diffraction limit, but a Freund and Fischer diffraction image is obtained. Since the aperture of a general optical system is circular, the images of Freund and Fischer diffraction are called Airy spots. Therefore, each object point is like a diffuse spot, two diffuse spots are not well distinguished after being close to each other, the resolution ratio of the system is limited, and the larger the spot is, the lower the resolution ratio is.

In an optical system, a lens influences the imaging quality, and a key index of the lens is an aperture F value, which directly influences the core functions of a camera, such as night scene, snapshot, background blurring, video and the like. The large aperture/super large aperture can be the main trend of the mobile phone camera because the virtual background of the picture can be increased and the main body can be highlighted when the large aperture (the aperture F value is smaller) lens is used for shooting, the shutter speed and the focusing speed can be improved, and the imaging quality is better.

To obtain a larger aperture for better image quality, a larger size aperture stop is required, however, as described in the background art, the aperture stop of the existing periscopic lens is usually disposed along the thickness direction of the mobile phone (i.e., along the Y direction in fig. 1), which is contrary to the consumer demand for an ultra-thin mobile phone.

In other words, the conventional periscopic lens is limited by the thickness of the mobile phone, and cannot be provided with an aperture stop with a larger size, so that the size of the aperture is limited, and the imaging quality of the lens is affected.

The embodiment of the application provides an optical lens, lens module and electronic equipment, can solve the limited problem of aperture diaphragm in the current periscopic camera lens for the camera lens that this application provided can have bigger aperture diaphragm, thereby can increase the light ring and the diffraction limit value of camera lens, is favorable to improving the image quality of camera lens.

In a first aspect, an embodiment of the present application first provides an optical lens. Fig. 2 is a schematic structural diagram of an optical lens 100 according to an embodiment of the present disclosure.

As shown in fig. 2, an optical lens 100 provided in the embodiment of the present application includes an aperture stop 10, a first mirror group 20, and a second mirror group 30.

The first mirror group 20 has positive power and is configured to receive and collect light, and the first mirror group 20 includes a reflective element (e.g., a prism 21 in fig. 1) configured to reflect light to transmit the light to the second mirror group 30.

The aperture stop 10 is located on the object side of the reflective element;

the second lens group 30 includes a plurality of lenses, the second lens group 30 is disposed on the image side of the first lens group 20, and the second lens group 30 is used for imaging light on a focal plane.

In the embodiment of the present application, the first mirror group 20 is capable of converging light and reflecting the light into the imaging lens group 30, and the shape, number, etc. of the lenses included in the first mirror group 20 are not limited, as long as one lens or a combination of lenses capable of achieving the above functions is within the scope of the present application, that is, in the present application, the first mirror group 20 may include only one lens. Here, the mirror includes at least a lens and a mirror.

It will be readily understood that the first mirror group 20 should include at least one lens having positive optical power in addition to at least one reflective element, and in some embodiments, the reflective element and the lens having positive optical power may be the same optical lens, such as a prism 21 having positive optical power in fig. 2, which will be described in detail later, and the prism 21 can reflect light and can also converge light. The advantage of above setting is, can reduce the quantity that sets up the lens, reduces the complexity of camera lens design to and practice thrift the cost.

In the embodiment of the present application, the aperture stop 10 is disposed on the object side of the reflective element, that is, the aperture stop 10 is disposed on the light path before the turning, and the plane of the aperture stop 10 is perpendicular to the thickness direction of the mobile phone (i.e., perpendicular to the Y direction in fig. 2), and the thickness of the aperture stop 10 is not limited by the thickness of the mobile phone, so that the aperture stop 10 with a larger size can be disposed in the embodiment of the present application.

On this basis, since the sizes of the lenses in the second lens group 30 are still limited by the thickness of the mobile phone, and the sizes of the lenses cannot be set to be larger, the first lens group 20 of the present application has positive focal power, and can converge and focus light and then reflect the light into the second lens group 30, thereby being beneficial to reducing the optical effective diameters of the lenses in the second lens group 30.

The optical lens that this application embodiment provided can set up aperture diaphragm 10 of bigger size, and then can obtain bigger entrance pupil diameter, under the certain circumstances of camera lens focus, can obtain littleer diaphragm F value, can obtain bigger diaphragm and diffraction limit value promptly to be favorable to improving periscopic optical lens 100's imaging quality.

The optical lens 100 provided in the embodiment of the present application is described in detail below with reference to fig. 2.

In the embodiment of the present application, the first mirror group 20 includes a reflective element, which is a prism 21. Further, the prism 21 has positive power, and can condense and reflect light into the imaging lens group 30.

Specifically, as shown in fig. 2, the optical lens 100 includes an aperture stop 10, a prism 21, and a second mirror group 30, which are disposed in order from the object side S1 to the image side S2 along the optical axis S3.

The shape of the effective light passage opening of the aperture stop 10 may be circular, the face of the effective light passage opening may be perpendicular to the optical axis S3, and the center of the effective light passage opening may be located on the optical axis S3. The aperture stop 10 may be made of any one of aluminum alloy, beryllium-aluminum alloy, titanium alloy, aluminum, beryllium, and the like.

In the present embodiment, the prism 21 may be disposed at any desired angle to bend the optical path. The prism 21 may be arranged to deflect the incident light path by a predetermined number of degrees (e.g., without limitation, 90 degrees), for example, such that the incident light is routed from propagating along a vertical optical axis (e.g., Y-direction in fig. 1) to propagating along a horizontal optical axis (e.g., Z-direction in fig. 1).

The prism 21 also has positive power, and can converge and focus incident light and then deflect the light into the imaging lens group 30.

As shown in fig. 2, in the embodiment of the present application, the prism 21 includes a reflection surface 21a capable of reflecting light, an incident surface (i.e., an object side surface) 21b facing the object side, and an exit surface (i.e., an image side surface) 21c facing the image side.

Alternatively, at least one of the reflection surface 21a, the incidence surface 21b, and the exit surface 21c should have positive optical power so that the requirement that the prism 21 has positive optical power can be satisfied.

In the embodiment of the present application, the surface shapes of the three side surfaces of the prism 21 are not limited as long as the prism 21 as a whole has positive refractive power.

For example, at least one of the reflection surface 21a, the incident surface 21b, and the emission surface 21c is a curved surface.

For another example, the reflecting surface 21a may be a curved surface, and the incident surface 21b and the exit surface 21c may be flat surfaces.

For another example, the reflection surface 21a may be a flat surface, and at least one of the incident surface 21b and the exit surface 21c may be a curved surface.

In the embodiment of the present application, the reflecting surface 21a, the incident surface 21b, and the exit surface 21c are all curved surfaces, and all have a certain focal power, and the focal powers of the three surfaces are reasonably distributed, so that the prism 21 as a whole can have a positive focal power.

In addition, in the embodiment of the present application, the optical power of the reflecting surface 21a and the incident surface 21b can be reasonably distributed to compress the optical width, so as to control the outer diameter of the emergent surface 21c, and further control the height of the prism 21 in the thickness direction of the mobile phone.

Alternatively, the reflecting surface 21a may be any one of surface types such as a spherical surface, an aspherical surface, and a free-form surface.

Alternatively, the incident surface 21b may be a spherical surface or an aspherical surface type.

Alternatively, the exit surface 21c may be a spherical surface or an aspherical surface type.

In the embodiment of the present application, the aspheric surface equation of each surface may be:

wherein z is the point on the aspheric surface with distance r from the optical axis, and the relative distance between the point and the intersection tangent plane tangent to the aspheric surface optical axis; r is the perpendicular distance between a point on the aspheric curve and the optical axis; c is the curvature; k is the conic coefficient; a to J are aspherical coefficients.

In the embodiment of the present application, the free-form surface equation of each surface may be:

wherein: z is the rise of the optical surface; k is a conic coefficient; c is the curvature; r is the height of radius in the direction of the optical axis, and is²＝x²+y²X and y are coordinates; c. C_jIs a monomial formula x^myⁿThe coefficient of (a).

In the embodiment of the present application, in order to improve the imaging quality, a highly reflective film layer may be provided on the reflective surface 21 a. Specifically, the reflective surface 21a may be designed to have a high reflective film layer, the thickness of the film layer is usually 4 or more, and the reflective surface can be extended to more film layers according to the reflective requirement defined by the system design.

Alternatively, the reflectivity of the reflective surface 21a may be required to be 95% or more in the visible light bandwidth, and no reflectivity constraint is imposed on the ultraviolet and near infrared.

Alternatively, in consideration of the near infrared and ultraviolet light blocking capability of the optical system, the film layer of the reflective surface 21a may be designed to have the characteristics of high reflection of visible light (380nm to 780nm) and high transmission of ultraviolet band (380nm or less) and near infrared band (780nnm or more), so that the entry of non-visible light into the image sensor can be reduced, and the imaging quality can be improved.

Further, when the aperture stop is enlarged, the size of the prism 21 is also enlarged, resulting in an increase in the weight of the prism 21, requiring a larger thrust actuator (activator), thereby increasing the difficulty in designing the actuator. To solve this problem, the embodiment of the present application uses a resin material instead of a conventional glass material to fabricate the prism 21.

The prism 21 that this application embodiment provided comprises resin material, can control prism 21's weight from this, reduces the degree of difficulty of actuator design and manufacturing in the lens module. In addition, according to the process characteristics of injection molding, the resin material can realize the surface shapes of a spherical surface, an aspherical surface, a free-form surface and the like with high precision requirements, and can meet the surface shape requirements of the prism 21 of the present application.

In the embodiment of the present application, after receiving the light, the prism 21 converges and reflects the light into the second mirror group 30, and the second mirror group 30 can image the incoming light on the focal plane of the image sensor.

The number of lenses of the second lens group 30, and the related configuration parameters of each lens are not limited in the present application.

As shown in fig. 2, in the embodiment of the present application, the second lens group 30 of the embodiment of the present application includes four lenses, namely, a first lens 31, a second lens 32, a third lens 33 and a fourth lens 34, which are disposed along the optical axis S3 from the object side S1 to the image side S2 in sequence. Wherein the center of each lens may be located on the optical axis S3, and each adjacent lens may have an air space therebetween. It will be readily appreciated that in other embodiments, the second mirror cluster 30 may include more or fewer lenses as desired.

In the present embodiment, the first lens 31 may have a negative power, the second lens 32 may have a positive power, the third lens 33 may have a negative power, and the fourth lens 34 may have a positive power.

In other embodiments, the first lens 31, the second lens 32, the third lens 33, and the fourth lens 34 may also distribute optical power in other manners, which is not limited in this application. For example, the first lens 31 may have a negative power, the second lens 32 may have a negative power, the third lens 33 may have a positive power, and the fourth lens 34 may have a positive power.

In the embodiment of the present application, each surface of the first lens element 31, the second lens element 32, the third lens element 33, and the fourth lens element 34 may be an aspheric surface, and the aspheric surface has a better curvature radius characteristic, and has the advantages of improving distortion aberration and improving astigmatism aberration, thereby improving imaging quality. In other embodiments, each lens may have other surface types according to needs, which is not limited in the present application.

The first lens 31, the second lens 32, the third lens 33, and the fourth lens 34 may be made of the same material or different materials, which is not limited in the present application.

For example, the first lens 31, the second lens 32, the third lens 33, and the fourth lens 34 may be made of the same material, so that the optical properties of the respective lenses are close to each other, thereby helping to reduce the difficulty of implementing the optical lens 100 in engineering.

It should be noted that the shape, size, thickness, and degree of concave-convex of the object side surface and the image side surface of the lens in fig. 2 are only schematic, and do not limit the embodiment of the present application at all.

As shown in fig. 2, in the embodiment of the present application, the optical lens 100 further includes a lens barrel 40, and the lens barrel 40 can be used to dispose four lenses of the second lens group 30.

As shown in fig. 2, in order to improve the imaging quality, an infrared filter 50 is further disposed on the image side of the second mirror group 30 to cut off, filter, and the like the infrared rays, and the infrared filter 50 may be, for example, a white glass filter, a blue glass filter, or the like.

In the assembling process of the optical lens 100 provided in the embodiment of the present application, the prism 21 and the second lens group 30 form an imaging group of a system, and the assembling yield needs to be ensured by a precise assembling process. The opto-mechanical structure may adopt a separate structure, that is, the four lenses of the second mirror group 30 are designed as a group G2, and the prism 21 and the aperture stop 10 are designed as a group G1. Considering that the optical performance of the system is sensitive to the relative eccentricity, inclination and air space of the G1 and G2 groups, an Active Alignment (AA) process needs to be introduced to complete the assembly of the groups G1 and G2, and then perform a secondary active alignment with the ir filter 50, the image sensor, etc.

Other sequences can be adopted in the assembly process, the group G2 can be assembled with the infrared filter 50 and the image sensor, and the group G2 has no independent optical performance, so that the assembly result between the two groups cannot detect the optical performance. Group G1 was added on the basis of the above, an active alignment process was performed, and the overall optical performance was examined.

Fig. 3 shows a schematic diagram of an optical lens 100 according to yet another embodiment of the present application. Referring to fig. 3, the present embodiment is substantially the same as the embodiment shown in fig. 2, except that the first mirror group 20 provided in the present embodiment includes a reflective element, and the reflective element is a curved mirror 22.

Specifically, compared to the foregoing embodiment shown in fig. 2, the reflecting element in this embodiment is a curved reflecting mirror 22, and the curved reflecting mirror 22 has positive optical power, and can also converge and reflect the incident light into the second mirror group 30.

Alternatively, the curved surface mirror 22 may be any one of a spherical surface mirror, an aspherical surface mirror, a free-form surface mirror, or the like. The curved surface reflector 22 includes a reflecting surface 22a, i.e., the surface of the reflecting surface 22a may be any one of a spherical surface, an aspherical surface, and a free-form surface.

Compared with the embodiment shown in fig. 2, the reflecting element of the present embodiment is a curved surface reflector 22, and compared with the prism 21, the present embodiment has only one reflecting surface 22a, and has no incident surface and no exit surface, so as to be beneficial to reducing the inter-surface reflection ghost of the optical lens 100, improve the light transmittance of the lens, and improve the imaging quality of the lens. In addition, the curved surface reflecting mirror 22 is lighter in weight than the prism 21, so that the difficulty in designing and manufacturing the actuator in the lens module can be reduced.

Alternatively, in order to further reduce the weight of the curved mirror 22, the curved mirror 22 may be formed of a resin material, and in order to meet the high accuracy requirement of the reflecting surface type, the curved mirror 22 may be formed by an injection molding process.

Alternatively, in order to improve the imaging quality, a highly reflective film layer may be provided on the reflective surface 22 a.

In the assembling process of the optical lens 100 provided in the embodiment of the present application, the curved reflector 22 and the second mirror group 30 form an imaging group of a system, and the precise grouping assembly is required. The separate structure design is performed on the optical machine structure, and the curved surface reflector 22 needs to be assembled separately because the curved surface reflector 22 is in a non-rotational symmetry shape. If the system architecture can be divided into three groups, i.e. aperture stop designed as group G1, curved mirror 22 designed as group G2, and second mirror group 30 designed as group G3. The group G3 is assembled with the near-infrared filter and the image sensor, and then is assembled into the group G2, and the temporary lens in this state does not have independent optical performance, and cannot detect the optical performance of the system. On the basis of the above, adding the group G1 requires introducing an active alignment process to complete the precise assembly of the group G1 and the groups G2 and G3, and mainly solves the assembly problems of relative eccentricity, inclination, spatial separation, and the like.

Fig. 4 shows a schematic diagram of an optical lens 100 according to still another embodiment of the present application. Referring to fig. 4, the present embodiment is substantially the same as the embodiment shown in fig. 2 and 3, except that the first mirror group 20 provided in the present embodiment includes a reflective element and a fifth lens, and the reflective element is a prism 21.

Specifically, compared with the foregoing embodiments shown in fig. 2 and 3, in this embodiment, the first mirror group 20 includes the fifth lens 23 and the prism 21, the first mirror group 20 has positive optical power, that is, the total optical power of the fifth lens 23 and the prism 21 is positive, and under the combined action of the fifth lens 23 and the prism 21, the incident light can be converged and reflected into the second mirror group 30.

In the present embodiment, it is only necessary to satisfy that the total power of the fifth lens 23 and the prism 21 is positive, and it is not necessary to limit whether the power of each of the fifth lens 23 and the prism 21 is positive or negative.

For example, the prism 21 has a positive power, and the fifth lens 23 has a negative power.

For another example, the prism 21 has positive refractive power, and the fifth lens 23 also has positive refractive power.

For another example, the prism 21 has a negative refractive power, and the fifth lens 23 has a positive refractive power.

Alternatively, the fifth lens 23 may be disposed on the object side of the prism 21, or may be disposed on the image side of the prism 21.

As shown in fig. 4, in the present embodiment, the fifth lens 23 is disposed on the object side of the prism 21. When the fifth lens 23 is disposed on the object side of the prism 21, the present application does not limit the front-rear order of the fifth lens 23 and the aperture stop 10 on the optical axis.

Alternatively, as shown in fig. 4, in the present embodiment, the aperture stop 10 is disposed on the object side of the fifth lens 23. In other embodiments, the aperture stop 10 may also be disposed between the fifth lens 23 and the prism 21, or the aperture stop 10 may also be disposed on the fifth lens 23, i.e., they may be disposed side by side.

Compared with the previous embodiment, the first lens group 20 of the present embodiment further includes a fifth lens 23 capable of providing optical power, so that the flexibility of the optical design of the prism 23 can be increased, the difficulty of designing the prism 23 can be reduced, and the surfaces of the prism 23 can be more flexibly selected to have the appropriate surface type and outer diameter.

For example, the width of light can be reduced by a combination of the object-side surface and the image-side surface of the fifth lens 23, and the radii of curvature of the total four surfaces, i.e., the reflection surface 23a and the incidence surface 23b of the prism 23, to control the outer diameter of the emission surface 23c of the prism 23, and further, the height of the prism 23 in the thickness direction of the mobile phone (i.e., the Y direction in fig. 4) can be controlled.

Optionally, the fifth lens 23 and the prism 21 may be connected by an Optical Clear Adhesive (OCA), so as to improve chromatic aberration of the optical lens 100. The optical adhesive is a double-sided adhesive tape without a base material, has the characteristics of no color, transparency, high light transmittance (total light transmittance is more than 99%), high adhesive force, high temperature resistance, ultraviolet resistance and the like, has controlled thickness, can provide uniform spacing, and does not cause the problems of yellowing, peeling and deterioration after long-term use.

It should be understood that the present application does not limit the number of the mirror plates included in the first mirror group 20, and the first mirror group 20 of the embodiment shown in fig. 2 and fig. 3 includes one reflective element, the first mirror group 20 of the present embodiment includes one reflective element and one lens, and in other embodiments, the first mirror group 20 may include more mirror plates, for example, may include one reflective element and a plurality of lenses.

In the assembling process of the optical lens 100 provided in the embodiment of the present application, the fifth lens 23, the prism 21 and the second lens group 30 form an imaging group of the lens, and the group-dividing precision assembly is required. The split structure design is performed on the optical machine structure, the prism 21 and the fifth lens 23 are optically cemented to form a group G1, and the second lens group 30 is designed as a group G2. The optical gluing process of the prism 21 and the fifth lens 23 needs to accurately control the optical eccentricity, inclination and other indexes of the two elements, and the requirement on the precision of the optical gluing process is high. The group G2 and the group G1 at the front end are actively aligned and assembled, and parameters such as relative eccentricity, inclination and space interval between the two groups are optimized to form the optical lens with optical performance. The optical lens is secondarily actively calibrated with the infrared filter 50, the image sensor, and the like, thereby completing the assembly of the optical lens.

The assembly process may be performed in another order, the group G2 may be assembled with the infrared filter 50 and the image sensor, and the temporary lens does not have independent optical performance, so that the optical performance cannot be detected as an assembly result. On the basis of the above, the optical adhesive assembly group G1 of the fifth lens 23 and the prism 21 is added to perform an active alignment process, so as to obtain complete optical performance.

Fig. 5 shows a schematic diagram of an optical lens 100 according to still another embodiment of the present application. Referring to fig. 5, the present embodiment is substantially the same as the embodiment shown in fig. 2 to 4, except that the first mirror group 20 provided in the present embodiment includes a reflective element and a fifth lens, and the reflective element is a curved mirror 22.

Specifically, compared with the foregoing embodiments shown in fig. 2 to 4, in this embodiment, the first mirror group 20 includes the fifth lens 23 and the curved reflector 22, the first mirror group 20 has positive optical power, that is, the total optical power of the fifth lens 23 and the curved reflector 22 is positive, and under the combined action of the fifth lens 23 and the curved reflector 22, the incident light can be converged and reflected into the second mirror group 30.

In the present embodiment, it is only necessary to satisfy that the total power of the fifth lens 23 and the curved surface reflecting mirror 22 is positive, and it is not necessary to limit whether the respective powers of the fifth lens 23 and the curved surface reflecting mirror 22 are positive or negative.

For example, the curved mirror 22 has a positive power, and the fifth lens 23 has a negative power.

For another example, the curved mirror 22 has a positive refractive power, and the fifth lens 23 also has a positive refractive power.

For another example, the curved mirror 22 has a negative refractive power, and the fifth lens 23 has a positive refractive power.

Alternatively, the fifth lens 23 may be disposed on the object side of the curved mirror 22, or may be disposed on the image side of the curved mirror 22.

As shown in fig. 5, in the present embodiment, the fifth lens 23 is disposed on the object side of the curved mirror 22, and the aperture stop 10 is disposed on the object side of the fifth lens 23. In other embodiments, the aperture stop 10 may be disposed between the fifth lens 23 and the curved mirror 22, or the aperture stop 10 may be disposed on the fifth lens 23, that is, they may be disposed side by side.

In the assembling process of the optical lens 100 provided in the embodiment of the present application, the fifth lens element 23, the curved reflector 22 and the second lens group 30 form an imaging group of the lens, and the group-dividing precision assembling is required. In the optical machine structure, a separate structure design is performed, and since the curved surface reflecting mirror 22 is located between the fifth lens 23 and the second mirror group 30, and the shape of the curved surface reflecting mirror 22 is non-rotationally symmetrical, the curved surface reflecting mirror 22 needs to be separately assembled. If the system structure can be divided into three groups, i.e. the fifth lens 23 and the aperture stop 10 are designed as group G1, the curved mirror 22 is designed as group G2, and the second mirror group 30 is designed as group G3. The group G3 is assembled with the infrared filter 50 and the image sensor, and then assembled into the group G2, and the temporary lens in this state does not have independent optical performance and cannot detect the optical performance of the system. On the basis, the addition of the group G1 requires the introduction of an active calibration process to complete the precise assembly of the group G1 and the temporary lens, and mainly solves the assembly problems of relative eccentricity, inclination, spatial separation and the like.

On the other hand, an embodiment of the present application further provides a lens module 500, and fig. 6 is a schematic structural diagram of the lens module 500 provided in the embodiment of the present application.

As shown in fig. 6, the lens module 500 includes an image sensor 200 and the optical lens 100 provided in any of the foregoing embodiments, and the optical lens 100 is used for imaging light to the image sensor 200.

Specifically, the lens 100 is used to form an optical signal of an object and reflect the optical signal to the image sensor 200, and the image sensor 200 converts the optical signal corresponding to the object into an image signal. The image sensor 200 may be a complementary metal-oxide semiconductor (CMOS) image sensor or a Charge Coupled Device (CCD) image sensor, and the image sensor 200 is mainly used for performing photoelectric conversion and Analog/Digital (a/D) conversion on an optical signal of light, thereby outputting image data for display on a display unit such as a display screen.

Since the lens module 500 adopts the optical lens 100 of any of the above embodiments, the lens module 500 also has the technical effect corresponding to the optical lens 100, and the details are not repeated herein.

Optionally, the lens module 500 may further include some or all of a holder (holder), an auto focus driving assembly, a circuit board, a connector, and peripheral electronic components (not shown). The holder may be used to hold the lens, and the auto-focus driving assembly may include a voice coil motor, a driving ic, and the like, for auto-focusing or optical anti-shake of the lens. The circuit board may be a Flexible Printed Circuit (FPC) or a Printed Circuit Board (PCB) for transmitting an electrical signal, wherein the FPC may be a single-sided flexible board, a double-sided flexible board, a multi-layer flexible board, a rigid flexible board, a hybrid-structured flexible circuit board, or the like. Other components that may be included in the lens module 500 are not described in detail herein.

On the other hand, an embodiment of the present application further provides an electronic device, and fig. 7 is a schematic structural diagram of the electronic device provided in the embodiment of the present application.

Parts (a) and (b) in fig. 7 are respectively a front view and a back view of an electronic device, as shown in fig. 7, the electronic device includes the lens module 500 provided in the foregoing embodiment, and further includes a housing 600 and a display screen 700, the display screen 700 is mounted on the housing 600, an accommodating space is formed in the housing 600, the lens module 500 can be mounted in the accommodating space, and the display screen 700 can be used for displaying pictures or videos shot by the lens module 500.

Alternatively, the housing 600 may be a metal housing, such as a metal of magnesium alloy, stainless steel, etc. In addition, the housing may be a plastic housing, a glass housing, a ceramic housing, or the like, but is not limited thereto.

Alternatively, the display screen 700 may be a Light Emitting Diode (LED) display screen, a Liquid Crystal Display (LCD) display screen, an organic light-emitting diode (OLED) display screen, or the like, but is not limited thereto.

Optionally, other devices such as, but not limited to, a battery, a flashlight, a fingerprint recognition module, an earpiece, a circuit board, a sensor, etc. may also be included in the housing 600.

The above description is only for the specific embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present application, and shall be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. An optical lens includes a first lens group, an aperture stop, and a second lens group,

the first mirror group has positive focal power and is used for receiving light rays and converging the light rays, and the first mirror group comprises a reflecting element which is used for reflecting the light rays so as to transmit the light rays to the second mirror group;

the aperture diaphragm is positioned on the object side of the reflecting element;

the second lens group comprises a plurality of lenses, is arranged at the image side of the first lens group, and is used for imaging the light rays on a focusing plane.

2. An optical lens according to claim 1, characterized in that the reflective element has positive optical power.

3. An optical lens according to claim 1 or 2, characterized in that the reflecting element comprises a reflecting surface, the reflecting surface being any one of a spherical surface, an aspherical surface or a free-form surface, the reflecting surface having positive optical power.

4. An optical lens according to claim 3, wherein the reflecting element is a prism, the prism comprising the reflecting surface, and an incident surface and an exit surface, the incident surface being spherical or aspherical, and the exit surface being spherical or aspherical.

5. An optical lens according to any of claims 1 to 3, characterized in that the reflecting element is a curved mirror.

6. The optical lens according to any one of claims 1 to 5, wherein the plurality of lenses includes a first lens having a negative optical power, a second lens having a positive optical power, a third lens having a negative optical power, and a fourth lens having a positive optical power, which are arranged in order from an object side to an image side.

7. An optical lens barrel according to any one of claims 1 to 6, wherein the first mirror group further includes a fifth lens on the object side of the reflective element, the fifth lens having a positive power or a negative power.

8. An optical lens according to claim 7, wherein the aperture stop is disposed on an object side of the fifth lens, or wherein the aperture stop is disposed between the fifth lens and the reflective element, or wherein the aperture stop is disposed on the fifth lens.

9. An optical lens barrel according to claim 7 or 8, wherein the fifth lens and the reflecting element are connected by an optical glue.

10. An optical lens according to any of claims 1 to 9, characterized in that a highly reflective film layer is provided on the reflective surface.

11. An optical lens according to any of claims 1 to 10, characterized in that the reflective element is composed of a resin material.

12. An optical lens according to any one of claims 1 to 11, further comprising an infrared filter disposed on the image side of the second lens group.

13. An optical lens according to any one of claims 1 to 12, characterized in that the optical lens further comprises a lens barrel for disposing the plurality of lenses.

14. A lens module comprising an image sensor and an optical lens according to any one of claims 1 to 13 for imaging light onto the image sensor.

15. An electronic apparatus, characterized in that the electronic apparatus comprises the lens module according to claim 14.