CN118169834A - Long-focus lens, camera module and electronic equipment - Google Patents

Long-focus lens, camera module and electronic equipment Download PDF

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Publication number
CN118169834A
CN118169834A CN202211580791.0A CN202211580791A CN118169834A CN 118169834 A CN118169834 A CN 118169834A CN 202211580791 A CN202211580791 A CN 202211580791A CN 118169834 A CN118169834 A CN 118169834A
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China
Prior art keywords
lens
equal
tele
light
less
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CN202211580791.0A
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Chinese (zh)
Inventor
周勇
陈柏宏
许坚强
陈洪福
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Huawei Technologies Co Ltd
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Huawei Technologies Co Ltd
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Priority to CN202211580791.0A priority Critical patent/CN118169834A/en
Priority to PCT/CN2023/137377 priority patent/WO2024120514A1/en
Publication of CN118169834A publication Critical patent/CN118169834A/en
Pending legal-status Critical Current

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    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B13/00—Optical objectives specially designed for the purposes specified below
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B13/00—Optical objectives specially designed for the purposes specified below
    • G02B13/18—Optical objectives specially designed for the purposes specified below with lenses having one or more non-spherical faces, e.g. for reducing geometrical aberration
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B17/00—Systems with reflecting surfaces, with or without refracting elements
    • G02B17/08—Catadioptric systems

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Lenses (AREA)

Abstract

A tele lens, a camera module and an electronic device. The lens comprises a lens and a lens group, wherein the object side surface of the lens is provided with a first transmission surface and a first reflection surface positioned in a paraxial region, the first transmission surface is arranged around the first reflection surface, the lens is provided with a groove, an opening of the groove is positioned in the paraxial region of the image side surface of the lens, the image side surface of the lens is provided with a second reflection surface arranged around the opening of the groove, and the wall of the groove is provided with a second transmission surface which is arranged opposite to the opening of the groove; the lens group is positioned on the image side of the lens and at least part of the lens group is positioned in the groove, and the curvature radius R1 of the second reflecting surface and the interval W between the first reflecting surface and the second transmitting surface on the optical axis are as follows: 2< |R1/W| <10. The long-focus lens has small optical total length while considering large aperture, large target surface and long focal length, so that the height of a camera module comprising the long-focus lens is small, and the application requirements of the electronic equipment on the thinning and folding machine are met.

Description

Long-focus lens, camera module and electronic equipment
Technical Field
The present application relates to the field of photographing devices, and in particular, to a telephoto lens, a camera module, and an electronic device.
Background
Along with the increasing demands of users for long-distance shooting, long-focus lenses are needed to be adopted in terminal camera modules to realize long-distance shooting. In addition, the height of the camera module is an important reason for restraining the whole thickness of the terminal, and the small height of the camera module can meet the application requirements of the terminal for thinning and the folding machine. However, the existing long-focus lens cannot meet the requirements of large aperture and large target surface while meeting the requirement of small height of the camera module, so that the imaging quality of the camera module is poor.
Disclosure of Invention
The application provides a long-focus lens, a camera module and electronic equipment, wherein the long-focus lens has smaller optical total length while taking a large aperture, a large target surface and a long focal length into account, so that the height of the camera module comprising the long-focus lens is small, and the application requirements of the electronic equipment on the thinning and folding machine are met.
In a first aspect, the present application provides a tele lens. The lens comprises a lens and a lens group, wherein the object side surface of the lens is provided with a first transmission surface and a first reflection surface, the first reflection surface is positioned in a paraxial region, the first transmission surface is arranged around the first reflection surface, the lens is provided with a groove, an opening of the groove is positioned in a paraxial region of the image side surface of the lens, the image side surface of the lens is provided with a second reflection surface, the second reflection surface is arranged around the opening of the groove, the wall of the groove is provided with a second transmission surface, and the second transmission surface is opposite to the opening of the groove; the lens group is positioned on the image side of the lens and at least part of the lens group is positioned in the groove; the curvature radius R1 of the second reflecting surface and the distance W between the first reflecting surface and the second transmitting surface on the optical axis satisfy the following conditions: 2< |R1/W| <10.
In the application, light reflected by a shot scene is emitted from a first transmission surface, propagates to a second reflection surface, is reflected to the first reflection surface through the second reflection surface, is reflected to a second transmission surface through the first reflection surface, and is emitted into a lens group through the second transmission surface. The first reflecting surface and the second reflecting surface can axially fold the light reflected by the shot scenery, so that the long-focus lens can have a longer focal length to realize long-range shooting, the total optical length TTL of the long-focus lens can be reduced, the thickness of the camera module is smaller, and the thinning requirement of electronic equipment and the application requirement of the folding machine are met.
In addition, at least part of the lens group is positioned in the groove, so that the lens and the lens group can realize space multiplexing in the thickness direction, the thickness of the long-focus lens is reduced, the thickness of the camera module is smaller, the occupied space is small, and the thinning requirement of electronic equipment and the application requirement of the folding machine are met.
In addition, by setting 2< |R1/W| <10, the imaging quality of the tele lens can be improved while ensuring the light incoming quantity and having smaller aberration.
In some implementations, the distance L between the first reflecting surface and the second reflecting surface on the optical axis and the distance W between the first reflecting surface and the second transmitting surface on the optical axis satisfy: the W/L is more than or equal to 0.1 and less than or equal to 0.9.
In the implementation mode, the setting of the W/L is less than or equal to 0.1 and less than or equal to 0.9, so that the blocking effect of the shading surface on direct stray light can be ensured while the molding difficulty of the lens is reduced, and the imaging quality of the tele lens is improved.
In some implementations, the radius of curvature R1 of the second reflective surface and the radius of curvature R2 of the first reflective surface satisfy: R1/R2 is more than or equal to 0.5 and less than or equal to 10.
In the implementation mode, the total optical length TTL of the tele lens can be improved while the tele lens is ensured to have smaller aberration by setting the R1/R2 to be less than or equal to 0.5 and less than or equal to 10, so that the imaging effect is improved.
In some implementations, the radius of curvature R2 of the first reflective surface and the radius of curvature R3 of the second transmissive surface satisfy: R2/R3 is more than or equal to 0.1 and less than or equal to 10.
In the implementation mode, the total optical length TTL of the tele lens can be improved while the tele lens is ensured to have smaller aberration by setting the R2/R3 to be more than or equal to 0.1 and less than or equal to 10 so as to improve the imaging effect.
In some implementations, the outer diameter D1 of the first transmissive surface and the outer diameter D2 of the first reflective surface satisfy: D2/D1 is less than or equal to 0.7, or D2/D1 is less than or equal to 0.2 and less than or equal to 0.7.
In the implementation mode, the D2/D1 is less than or equal to 0.7, so that the light inlet quantity of the lens group can be ensured. The ratio of effective light rays can be increased while the light quantity of the lens group is ensured, and the imaging quality is improved by setting the ratio of D2/D1 to be more than or equal to 0.2 and less than or equal to 0.7.
In some implementations, the outer diameter D4 of the second transmissive surface and the outer diameter D2 of the first reflective surface satisfy: D4/D2 is less than or equal to 1, or D4/D2 is less than or equal to 0.2 and less than or equal to 1.
In the implementation mode, D4/D2 is not more than 1, namely D4 is not more than D2, and through shielding of the first reflecting surface, direct incidence of light rays incident from the first transmitting surface into the second transmitting surface can be avoided as far as possible, direct stray light is reduced, and imaging quality is improved. The setting of D4/D2 is less than or equal to 0.2 and less than or equal to 1, and the light quantity can be increased while the direct stray light is reduced, so that the imaging quality is further improved.
In some implementations, a light shielding surface is disposed on a wall of the groove, and the light shielding surface surrounds the second transmission surface and is connected between the second transmission surface and an opening of the groove.
In this implementation manner, the light shielding surface is arranged on the groove, so that the direct stray light generated by directly injecting the light rays injected from the first transmission surface into the lens group from the side wall of the groove without being reflected by the second reflection surface and the first reflection surface can be avoided, and the imaging quality is influenced.
In some implementations, the light shielding surface is a conical surface, and the cone angle θ of the light shielding surface satisfies: θ is more than or equal to 0 and less than or equal to 30 degrees.
In the implementation mode, the theta is more than or equal to 0 degree and less than or equal to 30 degrees, so that the direct stray light can be effectively blocked while the molding difficulty of the lens is reduced, and the imaging quality of the long-focus lens is improved.
In some implementations, the light-blocking surface has a light transmittance of less than or equal to 10-2.
In the implementation mode, the light transmittance of the light shielding surface is smaller than or equal to 10 < -2 >, so that the blocking effect of the light shielding surface on direct stray light is ensured, and the imaging quality of the long-focus lens is improved.
In some implementations, the lens group includes a first lens proximate the object side, the first lens having a negative optical power.
In this implementation manner, the first lens L1 has negative focal power, and can diverge light rays of the feature lens through the first lens L1 to correct aberration of the feature lens and sign imaging quality of the camera module.
In some implementations, the lens group includes four lenses.
In this implementation manner, the lens group includes four lenses, so as to improve the specification of the tele lens and improve the imaging quality.
In some implementations, the total optical length TTL of the tele lens and the effective focal length EFL of the tele lens satisfy: TTL/EFL is more than or equal to 0.2 and less than or equal to 0.6.
In the implementation mode, through setting 0.2-0.6, the long-focus lens has long focal length, and has smaller total optical length TTL while long-distance shooting is satisfied, so that the height of a camera module comprising the long-focus lens is small, and the application requirements of the thin type electronic equipment and the folding machine are met.
In some implementations, the effective focal length EFL of the tele lens and the image height ImgH of the tele lens satisfy: imgH/EFL is more than or equal to 0.1 and less than or equal to 0.5.
In the implementation mode, the ImgH/EFL is not more than 0.1 and not more than 0.5, so that the long-focus lens has long focal length while realizing large field angle and large target surface, and has higher imaging quality and better long-distance shooting performance.
In a second aspect, the present application further provides a camera module, including a photosensitive element and a telephoto lens, where the photosensitive element is located on an image side of the telephoto lens.
The long-focus lens of the camera module provided by the application has smaller optical total length while taking large aperture, large target surface and long focal length into account, so that the height of the camera module comprising the long-focus lens is small, and the application requirements of the electronic equipment on the thinning and folding machine are met.
In a third aspect, the present application further provides an electronic device, including an image processor and a camera module, where the image processor is communicatively connected to the camera module, and the image processor is configured to obtain an image signal from the camera module and process the image signal.
The long-focus lens of the electronic equipment provided by the application has small optical total length while taking the large aperture, the large target surface and the long focal length into account, so that the height of a camera module comprising the long-focus lens is small, and the application requirements of the thin type electronic equipment and a folding machine are met.
Drawings
FIG. 1 is a schematic diagram of an electronic device according to some embodiments of the present application;
FIG. 2 is a schematic diagram of the camera module of FIG. 1 in some embodiments;
FIG. 3 is a schematic diagram of the internal structure of the electronic device shown in FIG. 1;
FIG. 4 is a schematic view of the lens of FIG. 2;
FIG. 5 is a schematic view of the optical path of the camera module of FIG. 2 in some embodiments;
FIG. 6 is a schematic diagram of a light path of direct stray light of the camera module of FIG. 2 in some embodiments;
FIG. 7 is a simulation effect diagram of the tele lens of FIG. 5;
FIG. 8 is a schematic diagram of an optical path of a camera module according to another embodiment of the present application;
FIG. 9 is a simulation effect diagram of the tele lens of FIG. 8;
fig. 10 is a schematic view of an optical path of a camera module according to another embodiment of the present application;
Fig. 11 is a simulation effect diagram of the tele lens shown in fig. 10.
Detailed Description
For convenience of understanding, the following explains and describes english abbreviations and related technical terms related to the embodiments of the application.
Optical power (foca l power), equal to the difference between the convergence of image Fang Guangshu and the convergence of the object beam, characterizes the ability of the optical system to deflect light.
A lens or group of lenses having positive optical power, the lens or group of lenses having a positive focal length, has the effect of converging light.
A lens or group of lenses having negative optical power, the lens or group of lenses having a negative focal length, has the effect of diverging light.
Focal length (foca l length), also known as focal length, is a measure of the concentration or divergence of light in an optical system, meaning the perpendicular distance from the optical center of a lens or lens group to the focal plane of an image when an infinitely distant scene is brought into clear images at the focal plane of the image by the lens or lens group. From a practical point of view it is understood that the distance from the centre of the lens to the plane is at infinity. The focal length of the lens assembly is the effective focal length (EFFECT IVE foca l length, EFL), which refers to the distance from the center of the lens to the focal point where the light is concentrated. The longer the effective focal length EFL, the stronger the resolution of the lens to the remote target; the shorter the effective focal length EFL, the larger the field of view of the lens.
The object side surface is defined by a lens, the object side surface is defined by the side where the object is located, and the surface of the lens close to the object side is called the object side surface.
The image side surface is defined by a lens, the image side surface is defined by the side of the image of the object, and the surface of the lens close to the image side is called the image side surface.
The object distance is the distance from the object to the object side of the lens.
An aperture stop (apertured i aphragm) is a device for controlling the amount of light transmitted through the lens and entering the photosensitive surface of the body, and is usually in the lens.
The aperture value, also called F-number (Fno), is the relative value (inverse of the relative aperture) derived from the focal length of the lens/the lens entrance pupil diameter. The smaller the aperture value, the more the amount of light is entered in the same unit time. The larger the aperture value is, the smaller the depth of field is, and the photographed background content will be virtual, similar to the effect of a tele lens.
Total length (tota L TRACK LENGTH, TTL), which refers to the total length from the surface of the lens closest to the object side to the imaging plane, TT L is the main factor in forming the camera height.
Back focus (backfoca l length, BFL), the distance of the lens closest to the image side in the lens to the imaging plane of the lens.
The imaging surface is positioned at the image side of all lenses in the long-focus lens, and light rays sequentially pass through all lenses in the long-focus lens to form an image carrier surface.
The field angle (fie l d of view, FOV), also known as field of view. In the optical apparatus, a lens of the optical apparatus is taken as a vertex, and an included angle formed by two edges of a maximum range of an object image of a subject passing through the lens is called a field angle.
The optical axis is an axis passing perpendicularly through the center of the lens. The lens optical axis is an axis passing through the center of each lens of the lens. When light parallel to the optical axis enters the convex lens, the ideal convex lens is a point where all light is converged behind the lens, and the point where all light is converged is a focal point.
Abbe number (Abbe), the Abbe's coefficient, is the ratio of the difference in refractive index of an optical material at different wavelengths, and represents the magnitude of the material's dispersion.
Aberration: the paraxial region of the optical system has the property of an ideal optical system, a paraxial ray emitted by a point on an object intersects with an image plane at a point (namely a paraxial image point), but rays actually passing through different apertures of a lens are difficult to perfectly intersect at a point, and have a certain deviation from the position of the paraxial image point, and the differences are generally called aberration.
Axial chromatic aberration (longitud INA L SPHER ICA L aber), also known as longitudinal chromatic aberration or positional chromatic aberration or axial chromatic aberration, a bundle of rays parallel to the optical axis, after passing through the lens, converges at different positions back and forth, this aberration being known as positional chromatic aberration or axial chromatic aberration. This is because the lens images light of each wavelength at different positions, so that the focal planes of the light of different colors cannot coincide when the light is finally imaged, and the light of multiple colors is scattered to form dispersion.
The image height (IMAGE HIGHT, IMGH) represents half the diagonal length of the effective pixel area on the photosensitive chip, namely the image height of the imaging plane.
The technical scheme in the embodiment of the application will be described below with reference to the accompanying drawings. Wherein, in the description of the embodiments of the present application, unless otherwise indicated, "/" means or, for example, a/B may represent a or B; the text "and/or" is merely an association relation describing the associated object, and indicates that three relations may exist, for example, a and/or B may indicate: the three cases where a exists alone, a and B exist together, and B exists alone, and furthermore, in the description of the embodiments of the present application, "plural" means two or more than two.
In the following, the terms "first," "second," and the like are used for descriptive purposes only and are not to be construed as implying or implying relative importance or as implying a number of such features. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature.
In describing embodiments of the present application, it should be noted that, unless explicitly stated and limited otherwise, the terms "mounted," "connected," and "connected" should be construed broadly, and for example, the terms "connected" may be removably connected or non-removably connected; may be directly connected or indirectly connected through an intermediate medium. Further, "fixed" as used herein is also to be understood broadly, e.g., as a direct fixation or as an indirect fixation via an intermediary. Wherein, "fixedly connected" means that the relative positional relationship is unchanged after being connected with each other. References to orientation terms, such as "near", "image side", "object side", etc., in embodiments of the present application are merely with reference to the orientation of the drawings, and thus the use of orientation terms is intended to better and more clearly illustrate and understand embodiments of the present application, rather than to indicate or imply that the apparatus or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore should not be construed as limiting embodiments of the present application.
In embodiments of the present application, the terms "first," "second," and the like 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 defining "a first" or "a second" may explicitly or implicitly include one or more such feature.
In embodiments of the present application, the term "plurality" refers to two or more than two. Furthermore, the term "and/or" is merely an association relation describing the association object, and means that three kinds of relations may exist, for example, a and/or B may mean: a exists alone, A and B exist together, and B exists alone. In addition, the character "/" herein generally indicates that the front and rear associated objects are an "or" relationship.
Reference in the specification to "one embodiment" or "some embodiments" or the like means that a particular feature, structure, or characteristic described in connection with the embodiment is included in one or more embodiments of the application. Thus, appearances of the phrases "in one embodiment," "in some embodiments," "in other embodiments," and the like in the specification are not necessarily all referring to the same embodiment, but mean "one or more but not all embodiments" unless expressly specified otherwise. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless expressly specified otherwise.
It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting of the invention. It should be noted that, for convenience of description, only the portions related to the invention are shown in the drawings.
The embodiment of the application provides electronic equipment. The electronic device may be an electronic product with a photographing or camera shooting function, such as a mobile phone, a tablet, a notebook computer, a television, a vehicle-mounted device, a wearable device, a video monitoring device, and the like. The wearable device may be a smart bracelet, a smart watch, a wireless headset, augmented reality technology (augmented rea l ity, AR) glasses, an augmented reality technology helmet, virtual reality technology (vi rtua l rea l ity, VR) glasses, a virtual reality technology helmet, and the like. The embodiment of the application is illustrated by taking the example that the electronic equipment is a mobile phone.
Referring to fig. 1, fig. 1 is a schematic diagram of an electronic device 100 according to an embodiment of the application.
As shown in fig. 1, in some embodiments, the electronic device 100 includes a camera module 10 and an image processor 20. The camera module 10 and the image processor 20 are accommodated in the electronic device 100, and the camera module 10 is used for collecting optical information outside the electronic device 100 and forming corresponding image signals. The image processor 20 is in communication connection with the camera module 10, and the image processor 20 is used for acquiring image signals from the camera module 10 and processing the image signals. The communication connection between the camera module 10 and the image processor 20 may include data transmission through electrical connection such as wiring, or may also realize data transmission through coupling. It will be appreciated that the camera module 10 and the image processor 20 may be communicatively connected by other means capable of data transmission.
In this embodiment, the electronic device 100 may be provided with a camera hole 30, the camera module 10 collects light through the camera hole 30, and the camera module 10 may be used as a rear camera of the electronic device 100. Illustratively, the camera hole 30 is fitted with a light-transmitting lens that allows light to pass therethrough and is dust-proof and waterproof.
In some embodiments, the camera module 10 may be used as a rear camera of the electronic device 100, and the camera hole 30 may be disposed on a rear cover of the electronic device 100. In other embodiments, the camera module 10 may also be used as a front camera of the electronic device 100. The image pickup hole 30 may be provided in a display screen of the electronic device 100.
For example, as shown in fig. 1, the camera module 10 of the electronic device 100 may be mounted on an upper portion of the electronic device 100. In addition, the installation position of the camera module 10 of the electronic device 100 in the embodiment shown in fig. 1 is merely illustrative, and the installation position of the camera module 10 is not strictly limited in the present application. In some other embodiments, the camera module 10 may be mounted at other locations of the electronic device 100, for example, the camera module 10 may be mounted at a middle or lower portion of the electronic device 100.
In some other embodiments, the electronic device 100 may also include a terminal body and an auxiliary component capable of rotating, moving, or detaching with respect to the terminal body, and the camera module 10 may also be disposed on the auxiliary component.
In some embodiments, the electronic device 100 may also include an analog-to-digital converter (also referred to as an A/D converter, not shown). The analog-to-digital converter is connected between the camera module 10 and the image processor 20. The analog-to-digital converter is used for converting an analog image signal generated by the camera module 10 into a digital image signal and transmitting the digital image signal to the image processor 20, and then the digital image signal is processed by the image processor 20 to obtain a processed image signal, and the processed image signal can be displayed through a display screen.
In some embodiments, the electronic device 100 may further include a memory (not shown) in communication with the image processor 20, and the image processor 20 may transmit the processed image signals to the memory, so that the processed image signals may be retrieved from the memory and displayed on the display screen at any time when the image is to be viewed later. In some embodiments, the image processor 20 further compresses the processed image signal and stores the compressed image signal in the memory to save the memory space.
Referring to fig. 1 and fig. 2 in combination, fig. 2 is a schematic structural diagram of the camera module 10 shown in fig. 1 in some embodiments.
As shown in fig. 2, in some embodiments, the camera module 10 includes a telephoto lens 1, a photosensitive element 2, and an optical filter 3.
Wherein the photosensitive element 2 is located at the image side of the tele lens 1. The camera module 10 may further include a circuit board (not shown), and the photosensitive element 2 may be fixed to the circuit board. Light can be irradiated to the photosensitive element 2 through the tele lens 1. In which fig. 2 illustrates the structure of the tele lens 1 in some embodiments, the tele lens 1 in the present application may have other structures, and the drawing cannot be regarded as a limitation of the structure of the tele lens 1.
The working principle of the camera module 10 is as follows: the light reflected by the photographed subject passes through the tele lens 1 to generate an optical image, which is projected onto the photosensitive element 2, and the photosensitive element 2 converts the optical image into an electrical signal, i.e., an analog image signal, and transmits the analog image signal to the analog-to-digital converter, so as to be converted into a digital image signal by the analog-to-digital converter to the image processor 20.
The photosensitive element 2 (also referred to as an image sensor) is a semiconductor chip, and has a surface including several hundred thousand to several million photodiodes, which generate electric charges when irradiated with light. The photosensitive element 2 may be a Charge Coupled Device (CCD) or a complementary metal oxide conductor device (comp LEMENTARY META L-oxide sem iconductor, CMOS). The charge coupled device is made of a semiconductor material with high photosensitivity and can convert light into electric charges. Charge-coupled devices are composed of a number of photosensitive units, typically in megapixels. When the surface of the charge coupling device is irradiated by light, each photosensitive unit reflects the charge on the component, and signals generated by all the photosensitive units are added together to form a complete picture. The complementary metal oxide semiconductor device is mainly made of two elements of silicon and germanium, so that N (negatively charged) and P (positively charged) level semiconductors coexist on the complementary metal oxide semiconductor device, and the currents generated by the two complementary effects can be recorded and interpreted into images by a processing chip.
In some embodiments, the photosensitive element 2 may move on a plane perpendicular to the thickness direction of the camera module 10 or be inclined with respect to the thickness direction of the camera module 10 to achieve anti-shake. At this time, the photosensitive element 2 does not have a motion capability in a thickness direction parallel to the camera module 10, or has a weak stroke much smaller than a focusing stroke to reduce the module thickness. In other embodiments, the photosensitive element 2 may also be a fixed member.
In some embodiments, the optical filter 3 may be located between the telephoto lens 1 and the photosensitive element 2, for filtering out unwanted bands of light, so as to prevent the photosensitive element 2 from generating false colors or ripples, so as to improve the effective resolution and color reduction thereof. The filter 3 may be an infrared filter 3, for example. In this embodiment, the optical filter 3 is a separate component, and in other embodiments, the optical filter 3 may be omitted, and the optical filter may be implemented by performing surface treatment or material treatment on at least one optical element of the telephoto lens 1. The application is not limited to the specific embodiment of the structure or structure used to achieve the filtering.
The tele lens 1 mainly uses the refraction principle of the lens to image, i.e. the light of the scenery passes through the tele lens 1 to form a clear image on the imaging plane, and the photosensitive element 2 on the imaging plane records the image of the scenery. Illustratively, the focal length of the tele lens 1 is > 8mm, for example: 10 mm, 20 mm, 35 mm, etc. The larger the focal length of the tele lens 1, the stronger the resolution capability to a tele target and the stronger the capability of long-range shooting. Further, the image height ImgH of the telephoto lens 1 >1/3 inch, for example: 1/2 inch, 1 inch, etc. In the present application, the telephoto lens 1 has a long focal length and a large panel size to have a strong telephoto shooting capability, and the imaging quality in the telephoto shooting is high.
The tele lens 1 may be a vertical lens or a periscope lens. The periscope type lenses are placed in parallel, a reflecting prism is introduced into the front end of the optical system, and long focal length is achieved through reflection of the reflecting prism. In the embodiment of the present application, the placement parallel to the screen is "parallel placement", and the placement perpendicular to the screen is "perpendicular placement". The dimension of the structure in the direction perpendicular to the screen is the thickness of the structure. Because periscope type lens parallel arrangement, a plurality of lenses and photosensitive element 2 of periscope type lens are arranged in proper order in the direction that is on a parallel with the screen, and photosensitive element 2 is placed perpendicularly to the screen for the size of photosensitive element 2 receives the restriction of cell-phone thickness, leads to the unable size of photosensitive element 2 to be done greatly, and periscope type lens's target surface size is less, and the imaging quality is poor.
Referring to fig. 3, fig. 3 is a schematic diagram illustrating an internal structure of the electronic device 100 shown in fig. 1 in some embodiments thereof. Fig. 3 schematically illustrates a structure of a screen 40, a camera module 10 and a rear cover 50 of the electronic device 100, where the screen 40 and the rear cover 50 are disposed opposite to each other, and the light hole 30 is disposed in the screen 40, and the camera module 10 is disposed between the screen 40 and the rear cover 50 and is disposed on the english light hole 30. In other embodiments, the electronic device 100 may also include other structures not illustrated in fig. 3.
The tele lens 1 of the camera module 10 provided by the embodiment of the application is a vertical lens, and a plurality of lenses, the optical filters 3 and the photosensitive elements 2 of the vertical lens are sequentially arranged in a direction perpendicular to the screen 40, and the photosensitive elements 2 are placed parallel to the screen 40, so that a larger space is provided. Therefore, the photosensitive element 2 of the vertical lens can be made large, has a large target surface size, and has high imaging quality.
However, due to the demand for the thin electronic device 100, the height of the upright lens is limited by the thickness h of the electronic device 100. In addition, the folding machine has two or more flat plate structures, and the plurality of flat plate structures of the folding machine can be in a folding state, so that the thickness of the flat plate structures of the folding machine is smaller, and the height requirement on the camera module 10 is higher.
The long focal lens 1 provided by the embodiment of the application is a vertical lens, has smaller optical total length while considering large aperture, large target surface and long focal length, so that the height of the camera module 10 comprising the long focal lens 1 is small, and the application requirements of the electronic equipment 100 on the thinning and folding machine are met. The tele lens 1 provided in the embodiment of the present application is described below.
Referring to fig. 2, fig. 4 and fig. 5 in combination, fig. 4 is a schematic structural diagram of the lens L0 shown in fig. 2, and fig. 5 is a schematic optical path diagram of the camera module 10 shown in fig. 2 in some embodiments. The structure within the dashed line in fig. 5 is a schematic structure of the lens group G in some embodiments, and the lens group G in the present application may have other structures, and the drawing should not be construed as limiting the structure of the lens group G.
The telephoto lens 1 includes a lens L0 and a lens group G, where the lens group G is located at an image side of the lens L0. Light reflected by the photographed subject is incident on the lens group G through the lens L0, and an optical image is generated by the lens group G. The structure within the dashed lines in fig. 2, 5,6, 8 and 10 is a schematic structure of the lens group G in some embodiments, and the lens group G in the present application may have other structures, and the drawing should not be construed as limiting the structure of the lens group G.
As shown in fig. 4, the object side surface of the lens L0 has a first transmitting surface 11 and a first reflecting surface 12. The first reflecting surface 12 is located in a paraxial region, the first transmitting surface 11 is disposed around the first reflecting surface 12, the lens L0 is provided with a groove 15, an opening of the groove 15 is located in the paraxial region of the image side of the lens L0, as shown in fig. 2, the lens group G is located on the image side of the lens L0, and at least part of the lens group G is located in the groove 15. The image side surface of the lens L0 is provided with a second reflecting surface 13, and the second reflecting surface 13 is arranged around the opening of the groove 15. The walls of the recess 15 have a second transmissive surface 14, the second transmissive surface 14 being arranged opposite the opening of the recess 15.
In the embodiment of the present application, as shown in fig. 5, the light reflected by the photographed object is incident from the first transmission surface 11, propagates to the second reflection surface 13, is reflected by the second reflection surface 13 to the first reflection surface 12, is reflected by the first reflection surface 12 to the second transmission surface 14, and is incident into the lens group G through the second transmission surface 14. The first reflecting surface 12 and the second reflecting surface 13 can axially fold the light reflected by the shot scenery, so that the tele lens 1 can have a longer focal length to realize tele shooting, and the total optical length TTL of the tele lens 1 can be reduced, so that the thickness of the camera module 10 is smaller, and the thin requirement of the electronic equipment 100 and the application requirement of the folding machine are met.
In addition, at least part of the lens group G is located in the groove 15, so that the lens L0 and the lens group G can realize spatial multiplexing in the thickness direction, so as to reduce the thickness of the telephoto lens 1, make the thickness of the camera module 10 smaller, occupy small space, and meet the requirements of thinning the electronic device 100 and the application of the folder.
Wherein the radius of curvature R1 of the second reflective surface 13, the on-axis distance W between the first reflective surface 12 and the second transmissive surface 14 satisfy: 2< |R1/W| <10.
On the other hand, the larger the R1/W, the larger the size of the spot formed by the light reflected by the second reflecting surface 13 to the first reflecting surface 12. In order to match the size of the light spot, it is necessary to increase the size of the first reflecting surface 12 to reflect the light reflected by the second reflecting surface 13 to the second transmitting surface 14 as much as possible. However, increasing the size of the first reflecting surface 12 reduces the range of the first transmitting surface 11, affecting the amount of light entering the lens group G. On the other hand, the smaller the R1/W, the greater the degree of deflection of the light reflected by the second reflecting surface 13, resulting in the larger the aberration caused by the second reflecting surface 13, and further affecting the contrast of the optical image formed by the telephoto lens 1, resulting in poor imaging quality.
In the embodiment of the present application, by setting |r1/w| <10, the spot size formed by the light reflected to the first reflecting surface 12 via the second reflecting surface 13 is made moderate, so that the sizes of the first reflecting surface 12 and the first transmitting surface 11 are made moderate to ensure the light entering amount of the lens group G. By setting 2< |r1/w|, aberration caused by the second reflecting surface 13 is made smaller, and higher imaging quality is obtained. Thus, by setting 2< |r1/w| <10, it is possible to have less aberration while securing the amount of light intake, improving the imaging quality of the tele lens 1.
Illustratively, the radius of curvature R1 of the second reflective surface 13, the on-axis distance W between the first reflective surface 12 and the second transparent surface may satisfy: 2< |R1/W| is less than or equal to 2.5, or 2.5< |R1/W| is less than or equal to 3, or 3< |R1/W| is less than or equal to 5. The range of |r1/w| can be adjusted according to the amount of light intake and the requirements of aberration.
Illustratively, the radius of curvature R1 of the second reflective surface 13, the on-axis distance L between the first reflective surface 12 and the second reflective surface 13 may satisfy: R1/L <20. In the embodiment of the present application, the axial distance L between the first reflecting surface 12 and the second reflecting surface 13 is the axial distance between the vertices of the first reflecting surface 12 and the second reflecting surface 13. The vertex of the second reflecting surface 13 is the closest point of the second reflecting surface 13 to the imaging surface.
In the embodiment of the present application, by setting |r1/l| <20, the spot size formed by the light reflected to the first reflecting surface 12 via the second reflecting surface 13 is made moderate, so that the sizes of the first reflecting surface 12 and the first transmitting surface 11 are made moderate to ensure the light entering amount of the lens group G.
In some embodiments, the radius of curvature R1 of the second reflective surface 13, the on-axis distance L between the first reflective surface 12 and the second reflective surface 13 may satisfy: 0< |R1/L| is less than or equal to 1. In the present embodiment, |r1/l| is smaller, the amount of light entering the lens group G is larger, but the aberration generated by the second reflection surface 13 is larger. The parameters of the lenses of the lens group G can be designed to eliminate the aberration generated by the second reflecting surface 13, so that the light entering amount of the lens group G is increased, and meanwhile, the aberration is smaller, and the imaging quality is improved.
For example, the radius of curvature R0 of the first transmission surface 11 may be smaller than zero or infinite, i.e., the first transmission surface 11 is convex toward the image side or planar. The first transmission surface 11 is convex toward the image side, so that light reflected by a larger-caliber photographed object can enter the tele lens 1 through the first transmission surface 11, and the light entering amount of the lens group G is increased.
The first transmissive surface 11 may be planar, spherical or aspherical, for example.
For example, the radius of curvature R1 of the second reflecting surface 13 may be smaller than zero, that is, the second reflecting surface 13 is convex toward the image side, so that the second reflecting surface 13 can gather light rays incident from the first transmitting surface 11 and reflect to the first reflecting surface 12.
For example, the radius of curvature R2 of the first reflecting surface 12 may be smaller than zero, that is, the first reflecting surface 12 is convex toward the image side, so that the first reflecting surface 12 can collect the light reflected by the second reflecting surface 13 to form a light cone, thereby better realizing the folding of the light path and further reducing the total optical length TTL.
For example, the radius of curvature R3 of the second transmission surface 14 may be smaller than zero or infinite, i.e. the second transmission surface 14 is convex or planar towards the image side. The second transmission surface 14 protrudes toward the image side, so that light can be further converged, which is beneficial to further reducing the total optical length TTL.
For example, the radius of curvature R2 of the first reflecting surface 12 and the radius of curvature R1 of the second reflecting surface 13 may satisfy: R1/R2 is more than or equal to 0.5 and less than or equal to 10.
In the embodiment of the application, by setting the ratio of R1/R2 to be more than or equal to 0.5 to be more than or equal to 10, the optical total length TTL of the tele lens 1 can be increased while ensuring that the tele lens 1 has smaller aberration, so that the imaging effect is improved.
For example, the radius of curvature R2 of the first reflective surface 12 and the radius of curvature R3 of the second transmissive surface 14 may satisfy: R2/R3 is more than or equal to 0.1 and less than or equal to 10.
In the embodiment of the application, by setting 0.1-10 and R2/R3-10, the optical total length TTL of the tele lens 1 can be improved while ensuring that the tele lens 1 has smaller aberration, so as to improve the imaging effect.
Referring to fig. 4 and 6 in combination, fig. 6 is a schematic diagram of the optical path of the direct stray light of the camera module 10 shown in fig. 2 in some embodiments, and fig. 6 is a straight line with an arrow in the middle to illustrate the optical path of the direct stray light in some embodiments. Fig. 6 illustrates only the optical path of the direct stray light in some embodiments and is not to be construed as limiting the optical path of the direct stray light. In other embodiments, direct stray light may also enter the lens group G through other paths. The structure within the dashed line in fig. 6 is a schematic structure of the lens group G in some embodiments, and the lens group G in the present application may have other structures, and the drawing should not be construed as limiting the structure of the lens group G.
For example, the outer diameter D1 of the first transmissive surface 11 and the outer diameter D2 of the first reflective surface 12 may satisfy: D2/D1 is less than or equal to 0.7. For example: the D2/D1 may be 0.32, 0.4, 0.5, etc.
In the embodiment of the present application, as shown in fig. 4, the outer contour of the projection of the first transmission surface 11 on the plane perpendicular to the optical axis O may be circular, and the outer diameter D1 of the first transmission surface 11 is the maximum diameter of the outer contour of the projection of the first transmission surface 11 on the plane perpendicular to the optical axis O. The outer contour of the projection of the first reflecting surface 12 on the plane perpendicular to the optical axis O may be circular, and the outer diameter D2 of the first reflecting surface 12 is the maximum diameter of the outer contour of the projection of the first reflecting surface 12 on the plane perpendicular to the optical axis O. The outer contour of the projection of the second reflecting surface 13 on the plane perpendicular to the optical axis O may be circular, and the outer diameter D3 of the second reflecting surface 13 is the maximum diameter of the outer contour of the projection of the second reflecting surface 13 on the plane perpendicular to the optical axis O. The outer contour of the projection of the second transmission surface 14 on the plane perpendicular to the optical axis O may be circular, and the outer diameter D4 of the second transmission surface 14 is the maximum diameter of the outer contour of the projection of the second transmission surface 14 on the plane perpendicular to the optical axis O.
As shown in fig. 5, the light incident from the first transmitting surface 11, reflected by the second reflecting surface 13 and the first reflecting surface 12, and entering the lens group G is effective light, and the optical image of the telephoto lens 1 in the embodiment of the present application is formed by the effective light. The light rays entering from the first transmission surface 11, reflected by the second reflection surface 13 or the first reflection surface 12 or not reflected by the second reflection surface 13 and the first reflection surface 12 are stray light, and the stray light can reduce the contrast of the optical image of the telephoto lens 1, thereby influencing the imaging quality.
The maximum range of the light rays that can be received by the second reflecting surface 13 and that are incident from the first transmitting surface 11 is an incident aperture, and the outer diameter D1 of the first transmitting surface 11 is greater than or equal to the incident aperture. The first reflecting surface 12 occupies a paraxial region of the incident aperture, and reduces the area into which light can enter. The smaller the outer diameter D2 of the first reflecting surface 12 is, the larger the area into which light can be incident is, thereby increasing the amount of light entering the lens group G. In the embodiment of the application, the D2/D1 is less than or equal to 0.7, so that the light entering quantity of the lens group G can be ensured.
In other embodiments, the outer diameter D1 of the first transmissive surface 11 and the outer diameter D2 of the first reflective surface 12 may also satisfy: D2/D1 is more than or equal to 0.2 and less than or equal to 0.7. The larger the outer diameter D2 of the first reflecting surface 12 is, the more light can be reflected to the second transmitting surface 14 as much as possible, and the better the reflecting effect of the first reflecting surface 12 on the light is, the larger the proportion of the effective light is. In the embodiment of the application, the D2/D1 is more than or equal to 0.2 and less than or equal to 0.7, so that the proportion of effective light rays can be increased while the light entering quantity of the lens group G is ensured, and the imaging quality is improved.
For example, the outer diameter D4 of the second transmissive surface 14 and the outer diameter D2 of the first reflective surface 12 may satisfy: D4/D2 is less than or equal to 1. For example: the D4/D2 may be 0.73, 0.8, etc.
In the embodiment of the application, D4/D2 is less than or equal to 1, namely D4 is less than or equal to D2, and the light rays emitted from the first transmission surface 11 can be prevented from directly emitting into the second transmission surface 14 as far as possible through the shielding of the first reflection surface 12, so that direct stray light is reduced, and the imaging quality is improved.
In other embodiments, the outer diameter D4 of the second transmissive surface 14 and the outer diameter D2 of the first reflective surface 12 may also satisfy: D4/D2 is more than or equal to 0.2 and less than or equal to 1.
The larger the outer diameter D4 of the second transmission surface 14 is, the more light rays are incident on the lens group G through the second transmission surface 14, and the amount of incident light of the lens group G can be increased. In the embodiment of the application, the D4/D2 is more than or equal to 0.2 and less than or equal to 1, so that the direct stray light is reduced, the light inlet quantity is increased, and the imaging quality is further improved.
Illustratively, the outer diameter D3 of the second reflecting surface 13 may be larger than the outer diameter D1 of the first transmitting surface 11, so that the second reflecting surface 13 can reflect as much light rays incident from the first transmitting surface 11 as possible, increasing the light-incident amount of the tele lens 1.
Illustratively, the lens L0 may be of unitary construction. By the two parts being of an integral construction is meant that during the formation of one of the two parts, the part is joined to the other part without the need to join the two parts together by re-working (e.g. gluing, welding, snap-in connection, screw connection).
For example: the lens L0 may be integrally formed by injection molding. In other embodiments, lens L0 may be molded using a molding and/or polishing process.
In the embodiment of the application, the lens L0 can be of an integrally formed structure, and the manufacturing difficulty is low so as to reduce the cost.
For example, the lens L0 may be made of plastic, and is integrally formed by injection molding, so that the manufacturing difficulty is low.
For example, the wall of the groove 15 may be provided with a light shielding surface 16, and the light shielding surface 16 surrounds the second transmission surface 14 and is connected between the second transmission surface 14 and the opening of the groove 15.
In the embodiment of the present application, the light shielding surface 16 is disposed in the groove 15, so that the light incident from the first transmission surface 11 is prevented from directly entering the lens group G from the side wall of the groove 15 without being reflected by the second reflection surface 13 and the first reflection surface 12, and direct stray light is prevented from affecting the imaging quality.
For example, referring to fig. 4, the light shielding surface 16 is a conical surface. In the embodiment of the application, the light shielding surface 16 is provided as a conical surface, so that the forming and processing of the groove 15 are facilitated, the forming difficulty of the lens L0 is reduced, and the manufacturing cost of the camera module 10 is reduced. In other embodiments, the light shielding surface 16 may be a surface with other shapes, such as a cylindrical surface, a prismatic surface, etc., which is not limited in the present application.
Illustratively, the cone angle θ of the light-shielding surface 16 may satisfy: θ is more than or equal to 0 and less than or equal to 30 degrees. For example: the taper angle θ may be 12 °, 18 °, or the like.
In the embodiment of the present application, the light shielding surface 16 is formed by rotating the bus bar around the optical axis O, and the taper angle θ of the light shielding surface 16 is the included angle between the bus bar of the light shielding surface 16 and the optical axis O.
On the other hand, the larger the taper angle θ of the light shielding surface 16 is, the lower the difficulty in forming the structure of the groove 15 of the lens L0 is. Specifically, the lens L0 may be integrally formed by injecting the injection molding liquid into the mold, the surface of the sidewall of the formed groove 15 is affected by the flow of the injection molding liquid and deviates from the designed ideal surface shape, and the larger the taper angle θ of the light shielding surface 16 is, the smaller the influence of the flow of the injection molding liquid is, and the smaller the deviation between the surface of the sidewall of the formed groove 15 and the ideal surface shape is. Furthermore, the wall of the groove 15 includes the second transmission surface 14, and the deviation between the surface of the sidewall of the formed groove 15 and the ideal surface shape is small, so that the second transmission surface 14 has better optical performance, so as to ensure the contrast ratio of the optical image and have higher imaging quality.
On the other hand, please refer to fig. 4 and 6 in combination. The smaller the taper angle θ of the light shielding surface 16 is, the better the blocking effect against direct stray light is. Specifically, in the case where the area of the opening of the groove 15 is unchanged, the smaller the taper angle θ of the light shielding surface 16, the larger the area of the second transmission surface 14 relative to the area of the opening of the groove 15, the amount of light entering the lens group G from the light reflected from the first reflection surface 12 can be increased. In addition, the smaller the taper angle θ is, the lower the reflectance of the light shielding surface 16 to the direct stray light is, so that the probability that the direct stray light is reflected to the second reflecting surface 13 through the light shielding surface 16 is reduced, and the blocking effect to the direct stray light is better. In addition, the smaller the taper angle θ, the smaller the opening of the groove 15, the larger the area of the corresponding second reflecting surface 13, so that more light rays entering from the first transmitting surface 11 can be contacted and reflected to the first reflecting surface 12, thereby improving the light entering amount of the lens group G and improving the imaging quality.
In the embodiment of the application, through setting the angle theta to be more than or equal to 0 DEG and less than or equal to 30 DEG, the direct stray light can be effectively blocked while the molding difficulty of the lens L0 is reduced, and the imaging quality of the tele lens 1 is improved.
Illustratively, the light-blocking surface 16 has a light transmittance of less than or equal to 10-2.
In the embodiment of the application, the light transmittance of the light shielding surface 16 is less than or equal to 10-2, so as to ensure the blocking effect of the light shielding surface 16 on direct stray light and improve the imaging quality of the tele lens 1.
Illustratively, the on-axis distance L between the first reflective surface 12 and the second reflective surface 13, and the on-axis distance W between the first reflective surface 12 and the second transmissive surface 14 may satisfy: the W/L is more than or equal to 0.1 and less than or equal to 0.9. For example: the W/L may be 0.42, 0.5, 0.6, etc. In the embodiment of the present application, the distance between the intersection points of the first reflective surface 12 and the second transmissive surface 14 and the optical axis O is the on-axis distance W between the first reflective surface 12 and the second transmissive surface 14.
In the embodiment of the present application, the magnitude of W/L affects the blocking effect of the light shielding surface 16 of the groove 15 on the direct stray light and the molding difficulty of the lens L0.
On the one hand, the smaller the |w/l| is, the smaller W is relative to L, and accordingly, the larger the proportion of L occupied by the light-shielding surface 16 of the groove 15 on the optical axis O is. The larger the range of the light shielding surface 16 is, the better the blocking effect on the direct stray light is, and the stray light entering at a large angle can be effectively shielded. In the embodiment of the present application, the included angle between the optical path of the stray light and the optical axis O is the incidence angle of the stray light, and the stray light with an incidence angle greater than 60 ° may be regarded as "the stray light is incident at a large angle".
On the other hand, the larger the |w/l| is, the larger W is relative to L, and the depth of the groove 15 is smaller. And the larger the |w/l| the smaller the size of the spot formed by the light reflected by the first reflective surface 12 to the second transmissive surface 14. The size of the second transmissive surface 14 needs to match the size of the spot, and the size of the second transmissive surface 14 is smaller. Because the depth of the groove 15 is smaller and the size of the second transmitting surface 14 is smaller, the molding difficulty of the lens L0 is lower.
In the embodiment of the application, the setting of the ratio of W/L is less than or equal to 0.1 and less than or equal to 0.9, so that the blocking effect of the light shielding surface 16 on direct stray light can be ensured while the molding difficulty of the lens L0 is reduced, and the imaging quality of the tele lens 1 is improved.
Illustratively, the on-axis distance L between the first reflective surface 12 and the second reflective surface 13, and the on-axis distance W between the first reflective surface 12 and the second transmissive surface 14 may satisfy: 0.4. Ltoreq.W/L. Ltoreq.0.45, for example: the W/L may be 0.4, 0.404, 0.42, etc.
It is to be understood that the above-mentioned definition of the parameters of the first transmissive surface 11, the first reflective surface 12, the second transmissive surface 14 and the second reflective surface 13 of the lens L0 may exist independently of each other or may be combined with each other. When the above ratio ranges are combined with each other, the tele lens 1 can obtain a smaller height and better imaging quality.
In some embodiments, referring to fig. 2, the lens group G may include four lenses arranged from an object side to an image side. The lens group G includes at least two lenses arranged along an object side to an image side to improve the specification of the telephoto lens 1 and improve imaging quality.
For example: the lens group G may include a first lens L1, a second lens L2, a third lens L3, and a fourth lens L4 arranged along an object side to an image side. In addition, the imaging picture has more balanced image quality by the design of the focal power of the plurality of lenses.
In the present embodiment, the lens group G includes a first lens L1 near the object side, and three lenses located at the image side of the first lens L1: the second lens L2, the third lens L3, and the fourth lens L4.
Illustratively, the first lens L1 has a negative optical power. The first lens L1 has negative focal power, and can diverge light rays of the feature lens through the first lens L1 to correct aberration of the feature lens, and sign imaging quality of the camera module 10.
Illustratively, the center of the vertex of the second lens L2 of the lens group G is located between the vertex of the second reflecting surface 13 and the vertex of the first reflecting surface 12 of the feature lens, so that the lens group G can extend into the groove 15 of the feature lens, and further, the optical total length TTL of the telephoto lens 1 is reduced by using space.
In other embodiments, the lens group G may also include three, five, or other numbers of lenses. The lens group G includes a first lens L1 near the object side, the first lens L1 having negative optical power. The lens group G may further include a plurality of lenses located on the image side of the first lens L1, for example: two, four, etc.
For example, the plurality of lenses of the lens group G may be made of the same material, such as glass, resin, or the like. Among them, glass has high refractive index and low expansion characteristics, so that the tele lens 1 has better imaging quality and low-temperature drift characteristics. The density of the resin is low, the weight of the lens group G can be reduced, the movement is convenient, and the focusing capability of the tele lens 1 is improved. In other embodiments, at least one lens of the plurality of lenses of the lens group G may be different from other lenses in material, which is not limited in the present application.
For example, some lenses of the lens group G may be glass, and other lenses may be resin, so that not only the imaging quality and the low-temperature drift characteristic of the telephoto lens 1 can be ensured, but also the weight of the lens group G can be reduced, and the focusing capability of the telephoto lens 1 can be improved.
Illustratively, the multiple lenses of lens group G may be molded using injection molding, compression molding, and/or finish grinding processes.
Illustratively, the optical total length TTL of the telephoto lens 1 and the effective focal length EFL of the telephoto lens 1 satisfy: TTL/EFL is more than or equal to 0.2 and less than or equal to 0.6. For example: TTL/E may be 0.33, 0.4, etc.
In the embodiment of the application, by setting 0.2-0.6 of TTL/EFL, the tele lens 1 has a long focal length, and has a smaller total optical length TTL while long-distance shooting is satisfied, so that the height of the camera module 10 comprising the tele lens 1 is small, and the application requirements of the electronic equipment 100 for thinning and a folding machine are satisfied.
Illustratively, the effective focal length EFL of the telephoto lens 1 and the image height ImgH of the telephoto lens 1 satisfy: imgH/EFL is more than or equal to 0.1 and less than or equal to 0.5.
On the other hand, the larger the ImgH/EFL is, the larger the field angle FOV of the telephoto lens 1 is, the larger the target surface is, and the higher the pixels of the optical image formed by the telephoto lens 1 are, and the imaging quality is good. On the other hand, the smaller the ImgH/EFL is, the larger the effective focal length EFL of the telephoto lens 1 is, so that an object having a longer distance can be photographed, the resolution capability on a remote target is strong, and the remote photographing performance is good.
In the embodiment of the application, the long-focus lens 1 has long focal length while realizing large field angle and large target surface by setting the ImgH/EFL to be more than or equal to 0.1 and less than or equal to 0.5, and simultaneously has higher imaging quality and better long-distance shooting performance.
Illustratively, the lens group G may be moved relative to the optic L0 to change the focal length of the tele lens 1. So that the tele lens 1 can adapt to shooting scenes with different object distances,
In other embodiments, the lens group G may be moved relative to the optic L0 to achieve focus.
In some embodiments, the camera module 10 may also include a drive mechanism. The driving mechanism may employ a focusing motor such as a voice coil motor, a memory metal motor, a ceramic motor, a stepping motor, or the like. In addition, the driving mechanism may have other structures, which are not limited in the present application.
In some embodiments, the camera module 10 may further include an anti-shake motor (not shown). The anti-shake motor is used for driving the tele lens 1 to move in a direction perpendicular to the optical axis O or to tilt and rotate relative to the optical axis O. The anti-shake motor may be a memory metal (shape memory a l loy) motor, a suspension motor, a ball motor, or the like.
In some embodiments, the tele lens 1 may further include an aperture stop (not shown), which may be mounted to the lens group G. At this time, the aperture stop has a better aperture adjustment effect, and the imaging quality of the telephoto lens 1 can be improved. The position of the aperture diaphragm can be fixed or variable. For example, the position of the aperture stop is variable, and the aperture stop can be adjusted to position between different lenses depending on the focus condition.
The aperture diaphragm can be a space ring structure or a variable fan blade structure; alternatively, the aperture stop may be implemented by a surface spray process, for example by spraying a light shielding material over the lens to form the aperture stop.
In some embodiments, the optical surface of at least one lens of the tele lens 1 is aspheric, and the aspheric optical surface has different powers from paraxial region to external view field region, so that the imaged picture has more uniform image quality. And/or the optical surface of at least one lens of the tele lens 1 may be a free-form surface to correct aberrations. Wherein the aspheric surface is a surface rotationally symmetrical around the optical axis O; the free-form surface may have no symmetry axis, may be symmetrical in a certain direction, or may be symmetrical in both directions.
In some embodiments, the multiple lenses of the tele lens 1 are assembled by an active calibration (ACT IVE A L IGNMENT, AA) process to ensure the assembly accuracy.
In some embodiments, the optical surface of at least one lens of the tele lens 1 may form a diffraction grating structure. In the present embodiment, by reasonably disposing the diffraction grating structure, chromatic aberration can be reduced, and the volume of the telephoto lens 1 can also be reduced.
In some embodiments, the tele lens 1 may further include a liquid lens (not shown), which may be located between the optic L0 and the lens group G, or between the lens group G and the filter 3. In the present embodiment, the focusing effect can be enhanced by the liquid lens to realize ultra-close-range shooting. The liquid lens is a structural member which uses liquid as a lens and changes the focal length by changing the curvature of the liquid.
In some embodiments, at least one lens of the telephoto lens 1 may adopt a special-shaped technology to reduce the size of the telephoto lens 1, so that the telephoto lens 1 can be better suitable for the miniaturized electronic device 100, and the application range of the telephoto lens 1 is increased. The incision may be accomplished by an I-CUT process. In addition, the height of the lens is reduced by a notch mode, so that the lens can be provided with a larger light-transmitting aperture, the light-transmitting quantity of the tele lens 1 is improved, and the imaging quality of the tele lens 1 is better. The special-shaped technology can be adopted on structural supports of lenses such as a lens barrel, a spacer and the like, so that the size of the tele lens 1 can be reduced.
In some embodiments, the peripheral side surface or the supporting surface of at least one lens of the telephoto lens 1 may be subjected to blackening treatment or roughening treatment to eliminate stray light and improve imaging quality. The blackening treatment may be a matting material such as black ink, or may be a film. Roughening is mainly used to increase roughness. Of course, in other embodiments, the telephoto lens 1 may also eliminate stray light in other manners, which is not strictly limited in the embodiments of the present application.
The implementation scheme of the tele lens 1 shown in fig. 5 in one possible embodiment is presented below in combination with data and simulation results.
Please refer to table 1a to table 1b, wherein table 1a is the radius of curvature, thickness, refractive index (Nd), abbe number of each lens and filter 3 when focusing on a long-focus lens 1 shown in fig. 5 in one possible embodiment. Wherein the thickness includes the thickness of the lenses themselves, as well as the distance between the lenses. Table 1b is the aspherical coefficients of each lens of the tele lens 1 shown in fig. 5 in one possible embodiment.
TABLE 1a
TABLE 1b
Face number Cone coefficient K A2 A4 A6 A8 A10 A12 A14
S11 0 0 0 0 0 0 0 0
S12 2.49E-01 0 1.83E-03 1.34E-03 -1.25E-03 6.47E-04 -2.08E-04 4.22E-05
S21 -2.27E-02 0.00E+00 5.35E-05 3.13E-07 -1.03E-08 3.95E-10 -9.97E-12 1.63E-13
S22 2.56E+00 0.00E+00 1.45E-03 -5.02E-04 6.62E-05 -8.11E-06 -5.69E-10 2.76E-11
S3 8.62E+00 0.00E+00 -6.80E-02 2.40E-01 -8.91E-01 2.29E+00 -3.79E+00 4.16E+00
S4 1.36E-01 0.00E+00 -1.39E-01 4.92E-01 -2.21E+00 6.58E+00 -1.27E+01 1.62E+01
S5 -7.02E+01 0.00E+00 -3.52E-03 -4.79E-01 3.29E+00 -1.59E+01 5.22E+01 -1.19E+02
S6 3.27E+01 0.00E+00 -3.44E-02 2.05E-01 -1.84E+00 8.05E+00 -2.13E+01 3.51E+01
S7 -9.80E+01 0.00E+00 2.35E-02 -1.96E-01 7.46E-01 -2.15E+00 4.17E+00 -5.47E+00
S8 1.04E+00 0.00E+00 -2.74E-02 -1.25E-01 4.31E-01 -1.01E+00 1.66E+00 -1.90E+00
S9 -9.65E+01 0.00E+00 -1.01E-01 2.54E-02 -7.12E-02 1.24E-01 -1.07E-01 5.56E-02
S10 -1.00E+00 0.00E+00 -3.62E-01 5.22E-01 -8.35E-01 9.74E-01 -7.94E-01 4.61E-01
A16 A18 A20 A22 A24 A26 A28 A30
S11 0 0 0 0 0 0 0 0
S12 -5.26E-06 3.67E-07 -1.10E-08 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00
S21 -1.53E-15 6.71E-18 -6.54E-21 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00
S22 -9.11E-13 2.44E-14 -8.03E-16 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00
S3 -3.06E+00 1.49E+00 -4.63E-01 8.27E-02 -6.48E-03 0.00E+00 0.00E+00 0.00E+00
S4 -1.39E+01 7.95E+00 -2.88E+00 6.01E-01 -5.48E-02 0.00E+00 0.00E+00 0.00E+00
S5 1.92E+02 -2.20E+02 1.77E+02 -9.82E+01 3.57E+01 -7.65E+00 7.33E-01 0.00E+00
S6 -3.29E+01 7.63E+00 2.20E+01 -3.22E+01 2.24E+01 -8.94E+00 1.98E+00 -1.88E-01
S7 4.96E+00 -3.16E+00 1.42E+00 -4.50E-01 9.73E-02 -1.37E-02 1.12E-03 -4.04E-05
S8 1.52E+00 -8.68E-01 3.52E-01 -1.00E-01 1.96E-02 -2.52E-03 1.89E-04 -6.34E-06
S9 -1.89E-02 4.23E-03 -6.12E-04 5.00E-05 -9.32E-07 -2.25E-07 2.08E-08 -5.94E-10
S10 -1.94E-01 5.94E-02 -1.33E-02 2.13E-03 -2.39E-04 1.78E-05 -7.90E-07 1.58E-08
In table 1a, the meanings of the symbols in the table are as follows.
R0: the radius of curvature at the paraxial of the first transmissive surface 11 of the object side of lens L0, where infinity means that the radius of curvature is infinity, i.e., the first transmissive surface 11 of the object side of lens L0 is planar. In the embodiment of the present application, the curvature radius at the paraxial of a certain surface means the curvature radius of a certain surface when the caliber thereof approaches zero.
R1: the radius of curvature at the paraxial of the second reflecting surface 13 of the image side surface of the lens L0.
R2: the radius of curvature at the paraxial of the first reflective surface 12 of the object side surface of the lens L0.
R3: the radius of curvature at the paraxial of the second transmission surface 14 of the image side of lens L0.
L: an on-axis distance between the second reflecting surface 13 on the image side of the lens L0 and the first reflecting surface 12 on the object side of the lens L0 (see fig. 4).
W: the on-axis distance between the first reflective surface 12 of the object side surface of the lens L0 and the second transmissive surface 14 of the image side surface of the lens L0 (see FIG. 4).
In the present application, the meaning of each symbol is the same as that of the symbol when the symbol is reappeared in the following unless otherwise stated, and the description thereof will not be repeated.
The positive and negative of the radius of curvature means that the optical surface is convex toward the object side or convex toward the image side, and when the optical surface (including the object side or the image side) is convex toward the object side, the radius of curvature of the optical surface is positive; when the optical surface (including the object side surface or the image side surface) is convex toward the image side, the optical surface is concave toward the object side surface, and the radius of curvature of the optical surface is negative.
The aspherical surface of the tele lens 1 of table 1a may be defined by, but not limited to, the following aspherical curve equation:
Wherein z is the relative distance between the point on the aspheric surface, which is at a distance r from the optical axis O, and the tangent plane of the intersection point on the aspheric surface optical axis O; r is the perpendicular distance between the point on the aspherical curve and the optical axis O; c is the curvature; k is a conical surface coefficient; ai is the i-th order aspheric coefficient, see table 1b.
According to the design parameters of table 1a and table 1b, the tele lens 1 with the basic parameters shown in table 1c and table 1d is designed, so that the tele lens 1 has a small optical total length while taking into consideration a large aperture, a large target surface and a long focal length, so that the height of the camera module 10 comprising the tele lens 1 is small, and the requirements of thinning the electronic device 100 and application of a folder are met.
Better imaging quality, and has the requirements of long focal length and small total optical length TTL. Referring to tables 1c and 1d in combination, tables 1c and 1d are basic parameters of the tele lens 1 shown in fig. 5 in one possible embodiment.
TABLE 1c
Parameters (parameters) Effective focal length EFL Aperture value Image height ImgH Total optical length TTL Half angle of view
Numerical value 34 Mm 2.6 6 Mm 9.1 Mm 6°
TABLE 1d
In the present embodiment, the radius of curvature R1 of the second reflective surface 13 is-13.5 mm, the distance W between the first reflective surface 12 and the second transmissive surface 14 on the optical axis O is 1.90 mm, and |r1/w| is 7.11, and in the range of 2< |r2/w| <10, the telephoto lens 1 can have smaller aberration while guaranteeing the light incoming amount, and the imaging quality of the camera module 10 is improved.
In the present embodiment, the distance L between the first reflecting surface 12 and the second reflecting surface 13 on the optical axis O is-4.70 mm, and the |w/l| is 0.40, and in the range of 0.1+|w/l|+| 0.9, the blocking effect of the light shielding surface 16 on the direct stray light can be ensured while the molding difficulty of the lens L0 is reduced, and the imaging quality of the camera module 10 is improved.
In the present embodiment, the radius of curvature R1 of the second reflecting surface 13 is-13.5 mm, the radius of curvature R2 of the first reflecting surface 12 is-5.27 mm, and |r1/r2| is 2.56, and in the range of 0.5+|r1/r2|+.10, the optical total length TTL of the telephoto lens 1 can be increased while ensuring that the telephoto lens 1 has less aberration, so as to increase the imaging effect.
In the present embodiment, the radius of curvature R3 of the second transmission surface 14 is-25.9 mm, and |r2/r3| is 0.20, in the range of 0.1+|r2/r3|+.10, the optical total length TTL of the telephoto lens 1 can be increased while ensuring that the telephoto lens 1 has less aberration, so as to increase the imaging effect.
In the present embodiment, the outer diameter D1 of the first transmissive surface 11 and the outer diameter D2 of the first reflective surface 12 satisfy d2/d1=0.3, and in the range of 0.2+.d2/d1+.0.7, the proportion of effective light can be increased while the light entering amount of the lens group G is ensured, and the imaging quality is improved.
In the present embodiment, the outer diameter D4 of the second transmitting surface 14 and the outer diameter D2 of the first reflecting surface 12 satisfy d4/d2=0.78, and in the range of 0.2+.d4/d2+.1, the amount of light entering can be increased while reducing direct stray light, and the imaging quality can be further improved.
In the present embodiment, the taper angle θ of the groove 15 of the lens L0 is 17 °, which satisfies: θ is more than or equal to 0 and less than or equal to 30 degrees, so that the direct stray light can be effectively blocked while the molding difficulty of the lens L0 is reduced, and the imaging quality of the tele lens 1 is improved.
In this embodiment, the optical power of the first lens L1 is-7.0 millimeters. The first lens L1 has negative focal power, and can diverge light rays of the feature lens through the first lens L1 to correct aberration of the feature lens, and sign imaging quality of the camera module 10.
In the present embodiment, the second lens L2 has an optical power of 46.5 millimeters and has a positive optical power; the third lens L3 has an optical power of-17.3 mm and has negative optical power; the focal power of the fourth lens L4 is-8.7 mm, the second lens L2 has negative focal power, the converging of light rays is facilitated, the miniaturization of the lens group G is realized, and the design of a large aperture is facilitated. In addition, the imaging picture has more balanced image quality by the design of the focal power of the plurality of lenses.
In the present embodiment, the total optical length TTL of the telephoto lens 1 is 9.1 mm, and the effective focal length EFL of the telephoto lens 1 is 34 mm, so that the TTL/EFL is 0.27, and in the range of 0.2-0.6, the telephoto lens 1 has a long focal length, and has a smaller total optical length TTL while satisfying long-distance shooting, so that the height of the camera module 10 including the telephoto lens 1 is small, and the application requirements of the folder and the thinning of the electronic device 100 are satisfied.
In the embodiment, the image height ImgH of the telephoto lens 1 is 6 mm, so that the ImgH/EFL is 0.18, and in the range of 0.1-0.5, the telephoto lens 1 has a long focal length while realizing a large field angle and a large target surface, and has higher imaging quality and better long-distance shooting performance.
In the embodiment, the aperture value F of the tele lens 1 is 2.6, and is in the range of 1.0-4.4, and the aperture value F is smaller, so that the light incoming amount of the lens is large, and the tele lens is suitable for a shooting environment with weak illumination.
Referring to fig. 7 in combination, fig. 7 is a simulation effect diagram of the telephoto lens 1 shown in fig. 5.
Fig. 7 is an axial chromatic aberration chart of the telephoto lens 1. Wherein the axial chromatic aberration curve comprises spherical aberration curves corresponding to different wave bands (the illustrations comprise 650nm, 610nm, 555nm, 510nm and 470 nm) of the system; the abscissa is the deviation value along the optical axis O, and the ordinate is the normalized coordinate at the pupil, i.e. the normalized aperture. The physical meaning of the axial chromatic aberration curve graph is that the light with corresponding wavelength emitted from the 0-degree view field deviates from an ideal image point after passing through an optical system; the smaller the absolute value of the deviation value, the better the aberration correction effect of the optical system, and the higher the imaging quality of the telephoto lens 1. As can be seen from fig. 7, the deviation values are smaller than or equal to 0.04 mm in the ranges of different wave bands and full aperture bands, that is, the spherical aberration of the camera module 10 is smaller than or equal to 0.04 mm, which means that the on-axis aberration (spherical aberration, chromatic aberration, etc.) of the telephoto lens 1 is better corrected.
Referring to fig. 8 in combination, fig. 8 is a schematic view illustrating an optical path of a camera module 10 according to another embodiment of the application. The structure within the dashed line in fig. 8 is a schematic structure of the lens group G in some embodiments, and the lens group G in the present application may have other structures, and the drawing should not be construed as limiting the structure of the lens group G.
In some embodiments, the camera module 10 includes a telephoto lens 1, an optical filter 3, and a photosensitive element 2, where the telephoto lens 1 includes a lens L0 and a lens group G, and the lens group G is located on an image side of the lens L0. The object side surface of the lens L0 has a first transmitting surface 11 and a first reflecting surface 12. The first reflecting surface 12 is located in a paraxial region, the first transmitting surface 11 is disposed around the first reflecting surface 12, the lens L0 is provided with a groove 15, an opening of the groove 15 is located in the paraxial region of the image side surface of the lens L0, and at least part of the lens group G is located in the groove 15. The image side surface of the lens L0 is provided with a second reflecting surface 13, and the second reflecting surface 13 is arranged around the opening of the groove 15. The walls of the recess 15 have a second transmissive surface 14, the second transmissive surface 14 being arranged opposite the opening of the recess 15.
In the present embodiment, the lens group G includes a first lens L1, a second lens L2, a third lens L3, and a fourth lens L4 arranged along the object side to the image side. Along the direction of the optical axis O, the light passes through the lens L0, the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, and the optical filter 3 in order, and finally reaches the photosensitive element 2.
In the embodiment of the present application, the light reflected by the photographed object is incident from the first transmission surface 11, propagates to the second reflection surface 13, is reflected by the second reflection surface 13 to the first reflection surface 12, is reflected by the first reflection surface 12 to the second transmission surface 14, and is incident into the lens group G through the second transmission surface 14. The first reflecting surface 12 and the second reflecting surface 13 can axially fold the light reflected by the shot scenery, so that the tele lens 1 can have a longer focal length to realize tele shooting, and the total optical length TTL of the tele lens 1 can be reduced, so that the thickness of the camera module 10 is smaller, and the thin requirement of the electronic equipment 100 and the application requirement of the folding machine are met.
The implementation scheme of the tele lens 1 shown in fig. 8 in one possible embodiment is presented below in combination with data and simulation results.
Please refer to table 2a to table 2b, wherein table 2a is the radius of curvature, thickness, refractive index (Nd), abbe number of each lens and the optical filter 3 when focusing on the long-focus lens 1 shown in fig. 8 in one possible embodiment. Wherein the thickness includes the thickness of the lenses themselves, as well as the distance between the lenses. Table 2b is the aspherical coefficients of each lens of the tele lens 1 shown in fig. 8 in one possible embodiment.
TABLE 2a
TABLE 2b
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The aspherical surface of the tele lens 1 of table 2a can be defined by, but not limited to, the following aspherical curve equation:
Wherein z is the relative distance between the point on the aspheric surface, which is at a distance r from the optical axis O, and the tangent plane of the intersection point on the aspheric surface optical axis O; r is the perpendicular distance between the point on the aspherical curve and the optical axis O; c is the curvature; k is a conical surface coefficient; ai is the i-th order aspheric coefficient, see table 2b.
According to the design parameters of table 2a and table 2b, the tele lens 1 with the basic parameters shown in table 2c and table 2d is designed, so that the tele lens 1 has a small optical total length while taking into consideration a large aperture, a large target surface and a long focal length, so that the height of the camera module 10 comprising the tele lens 1 is small, and the requirements of thinning the electronic device 100 and application of a folder are met.
Better imaging quality, and has the requirements of long focal length and small total optical length TTL. Referring to tables 2c and 2d in combination, tables 2c and 2d are basic parameters of the tele lens 1 shown in fig. 8 in one possible embodiment.
TABLE 2c
Parameters (parameters) Effective focal length EFL Aperture value Image height ImgH Total optical length TTL Half angle of view
Numerical value 23 Mm 2.5 5 Mm 7.5 Mm 6°
TABLE 2d
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In the present embodiment, the radius of curvature R1 of the second reflective surface 13 is-8.98 mm, the distance W between the first reflective surface 12 and the second transmissive surface 14 on the optical axis O is 1.30 mm, and the |r1/w| is 6.91, and in the range of 2< |r1/w| <10, the telephoto lens 1 can have smaller aberration while guaranteeing the light incoming amount, and the imaging quality of the camera module 10 is improved.
In the present embodiment, the distance L between the first reflecting surface 12 and the second reflecting surface 13 on the optical axis O is-3.10 mm, and the |w/l| is 0.42, and in the range of 0.1+|w/l|+| 0.9, the blocking effect of the light shielding surface 16 on the direct stray light can be ensured while the molding difficulty of the lens L0 is reduced, and the imaging quality of the camera module 10 is improved.
In the present embodiment, the radius of curvature R1 of the second reflecting surface 13 is-8.98 mm, the radius of curvature R2 of the first reflecting surface 12 is-3.34 mm, and |r1/r2| is 2.69, and in the range of 0.5+|r1/r2|+.10, the optical total length TTL of the telephoto lens 1 can be increased while ensuring that the telephoto lens 1 has less aberration, so as to increase the imaging effect.
In the present embodiment, the radius of curvature R3 of the second transmission surface 14 is-12.4 mm, and |r2/r3| is 0.27, in the range of 0.1+|r2/r3|+.10, the optical total length TTL of the telephoto lens 1 can be increased while ensuring that the telephoto lens 1 has less aberration, to increase the imaging effect.
In the present embodiment, the outer diameter D1 of the first transmissive surface 11 and the outer diameter D2 of the first reflective surface 12 satisfy d2/d1=0.32, and in the range of 0.2+.d2/d1+.0.7, the proportion of effective light can be increased while the light entering amount of the lens group G is ensured, and the imaging quality is improved.
In the present embodiment, the outer diameter D4 of the second transmitting surface 14 and the outer diameter D2 of the first reflecting surface 12 satisfy d4/d2=0.73, and in the range of 0.2+.d4/d2+.1, the amount of light entering can be increased while reducing direct stray light, and the imaging quality can be further improved.
In the present embodiment, the taper angle θ of the groove 15 of the lens L0 is 12 °, which satisfies: θ is more than or equal to 0 and less than or equal to 30 degrees, so that the direct stray light can be effectively blocked while the molding difficulty of the lens L0 is reduced, and the imaging quality of the tele lens 1 is improved.
In this embodiment, the optical power of the first lens L1 is-4.5 mm. The first lens L1 has negative focal power, and can diverge light rays of the feature lens through the first lens L1 to correct aberration of the feature lens, and sign imaging quality of the camera module 10.
In this embodiment, the second lens L2 has an optical power of-36.4 mm and has a negative optical power; the third lens L3 has an optical power of 14.5 mm and has positive optical power; the fourth lens L4 has negative focal power of-17.4 mm. The imaging picture has more balanced image quality by the design of the focal power of the plurality of lenses.
In the present embodiment, the total optical length TTL of the telephoto lens 1 is 7.5 mm, and the effective focal length EFL of the telephoto lens 1 is 23 mm, so that the TTL/EFL is 0.33, and in the range of 0.2-0.6, the telephoto lens 1 has a long focal length, and has a smaller total optical length TTL while satisfying long-distance shooting, so that the height of the camera module 10 including the telephoto lens 1 is small, and the application requirements of the folder and the thinning of the electronic device 100 are satisfied.
In the embodiment, the image height ImgH of the telephoto lens 1 is 5mm, so that the ImgH/EFL is 0.22, and in the range of 0.1-0.5, the telephoto lens 1 has a long focal length while realizing a large field angle and a large target surface, and has higher imaging quality and better long-distance shooting performance.
In the embodiment, the aperture value F of the tele lens 1 is 2.5, and is in the range of 1.0-4.4, and the aperture value F is smaller, so that the light incoming amount of the lens is large, and the tele lens is suitable for a shooting environment with weak illumination.
Referring to fig. 9 in combination, fig. 9 is a simulation effect diagram of the telephoto lens 1 shown in fig. 8.
Fig. 9 is an axial chromatic aberration chart of the telephoto lens 1. Wherein the axial chromatic aberration curve comprises spherical aberration curves corresponding to different wave bands (the illustrations comprise 650nm, 610nm, 555nm, 510nm and 470 nm) of the system; the abscissa is the deviation value along the optical axis O, and the ordinate is the normalized coordinate at the pupil, i.e. the normalized aperture. The physical meaning of the axial chromatic aberration curve graph is that the light with corresponding wavelength emitted from the 0-degree view field deviates from an ideal image point after passing through an optical system; the smaller the absolute value of the deviation value, the better the aberration correction effect of the optical system, and the higher the imaging quality of the telephoto lens 1. As can be seen from fig. 9, the deviation values are smaller than or equal to 0.04 mm in the ranges of different wave bands and full aperture bands, that is, the spherical aberration of the camera module 10 is smaller than or equal to 0.04 mm, which means that the on-axis aberration (spherical aberration, chromatic aberration, etc.) of the telephoto lens 1 is better corrected.
Referring to fig. 10 in combination, fig. 10 is a schematic view illustrating an optical path of a camera module 10 according to another embodiment of the application. The structure within the dashed line in fig. 10 is a schematic structure of the lens group G in some embodiments, and the lens group G in the present application may have other structures, and the drawing should not be construed as limiting the structure of the lens group G.
In some embodiments, the camera module 10 includes a telephoto lens 1, an optical filter 3, and a photosensitive element 2, where the telephoto lens 1 includes a lens L0 and a lens group G, and the lens group G is located on an image side of the lens L0. The object side surface of the lens L0 has a first transmitting surface 11 and a first reflecting surface 12. The first reflecting surface 12 is located in a paraxial region, the first transmitting surface 11 is disposed around the first reflecting surface 12, the lens L0 is provided with a groove 15, an opening of the groove 15 is located in the paraxial region of the image side surface of the lens L0, and at least part of the lens group G is located in the groove 15. The image side surface of the lens L0 is provided with a second reflecting surface 13, and the second reflecting surface 13 is arranged around the opening of the groove 15. The walls of the recess 15 have a second transmissive surface 14, the second transmissive surface 14 being arranged opposite the opening of the recess 15.
In the present embodiment, the lens group G includes a first lens L1, a second lens L2, a third lens L3, and a fourth lens L4 arranged along the object side to the image side. Along the direction of the optical axis O, the light passes through the lens L0, the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, and the optical filter 3 in order, and finally reaches the photosensitive element 2.
In the embodiment of the present application, the light reflected by the photographed object is incident from the first transmission surface 11, propagates to the second reflection surface 13, is reflected by the second reflection surface 13 to the first reflection surface 12, is reflected by the first reflection surface 12 to the second transmission surface 14, and is incident into the lens group G through the second transmission surface 14. The first reflecting surface 12 and the second reflecting surface 13 can axially fold the light reflected by the shot scenery, so that the tele lens 1 can have a longer focal length to realize tele shooting, and the total optical length TTL of the tele lens 1 can be reduced, so that the thickness of the camera module 10 is smaller, and the thin requirement of the electronic equipment 100 and the application requirement of the folding machine are met.
The implementation scheme of the tele lens 1 shown in fig. 10 in one possible embodiment is presented below in combination with data and simulation results.
Please refer to tables 3a to 3b together, wherein table 3a is the radius of curvature, thickness, refractive index (Nd), abbe number of each lens and filter 3 when the tele lens 1 shown in fig. 10 is focused in one possible embodiment. Wherein the thickness includes the thickness of the lenses themselves, as well as the distance between the lenses. Table 3b is the aspherical coefficients of each lens of the tele lens 1 shown in fig. 10 in one possible embodiment.
TABLE 3a
TABLE 3b
Face number Cone coefficient K A2 A4 A6 A8 A10 A12 A14
S12 -8.95E-02 0 5.32E-05 3.47E-07 -1.01E-08 3.25E-10 -6.62E-12 9.24E-14
S21 -1.32E-01 0.00E+00 2.29E-03 9.66E-04 -9.37E-04 4.52E-04 -1.34E-04 2.52E-05
S22 1.01E+01 0.00E+00 -7.55E-03 2.24E-03 -3.25E-04 1.78E-05 -3.67E-10 0.00E+00
S3 0.00E+00 0.00E+00 3.94E-01 -3.20E-01 2.18E-01 -7.94E-03 -1.36E-01 1.28E-01
S4 0.00E+00 0.00E+00 2.38E-01 -2.52E-01 6.79E-01 -1.65E+00 2.51E+00 -2.31E+00
S5 0.00E+00 0.00E+00 -1.90E-01 3.21E-01 -8.58E-01 2.03E+00 -3.15E+00 3.06E+00
S6 -1.00E+00 0.00E+00 -1.30E-01 4.39E-01 -1.63E+00 4.44E+00 -7.64E+00 8.26E+00
S7 -1.00E+00 0.00E+00 -1.53E-01 7.09E-02 -1.02E-02 -1.72E-02 1.65E-02 -7.06E-03
S8 -1.00E+00 0.00E+00 -1.80E-01 1.13E-01 -6.13E-02 2.45E-02 -6.91E-03 1.37E-03
S9 0.00E+00 0.00E+00 -1.49E-02 2.94E-03 1.07E-02 -1.17E-02 5.66E-03 -1.51E-03
S10 0.00E+00 0.00E+00 -1.31E-02 -6.41E-04 7.43E-03 -5.93E-03 2.36E-03 -5.40E-04
A16 A18 A20 A22 A24 A26 A28 A30
S12 -8.30E-16 4.29E-18 -9.62E-21 0 0 0 0 0
S21 -2.89E-06 1.86E-07 -5.14E-09 0 0 0 0 0
S22 0.00E+00 0.00E+00 0.00E+00 0 0 0 0 0
S3 -5.62E-02 1.24E-02 -1.10E-03 0 0 0 0 0
S4 1.25E+00 -3.71E-01 4.57E-02 0 0 0 0 0
S5 -1.81E+00 5.94E-01 -8.32E-02 0 0 0 0 0
S6 -5.45E+00 2.00E+00 -3.13E-01 0 0 0 0 0
S7 1.62E-03 -1.93E-04 9.27E-06 0 0 0 0 0
S8 -1.91E-04 1.73E-05 -7.47E-07 0 0 0 0 0
S9 2.31E-04 -1.87E-05 6.19E-07 0 0 0 0 0
S10 7.16E-05 -5.08E-06 1.49E-07 0 0 0 0 0
The aspherical surface of the tele lens 1 of table 3a can be defined by, but not limited to, the following aspherical curve equation:
wherein z is the relative distance between the point on the aspheric surface, which is at a distance r from the optical axis O, and the tangent plane of the intersection point on the aspheric surface optical axis O; r is the perpendicular distance between the point on the aspherical curve and the optical axis O; c is the curvature; k is a conical surface coefficient; ai is the i-th order aspheric coefficient, see table 3b.
According to the design parameters of table 3a and table 3b, the tele lens 1 with the basic parameters shown in table 3c and table 3d is designed, so that the tele lens 1 has a small optical total length while taking into consideration a large aperture, a large target surface and a long focal length, so that the height of the camera module 10 comprising the tele lens 1 is small, and the requirements of thinning the electronic device 100 and application of the folding machine are met.
Better imaging quality, and has the requirements of long focal length and small total optical length TTL. Referring to tables 3c and 3d in combination, tables 3c and 3d are basic parameters of the tele lens 1 shown in fig. 10 in one possible embodiment.
TABLE 3c
Parameters (parameters) Effective focal length EFL Aperture value Image height ImgH Total optical length TTL Half angle of view
Numerical value 34.5 Mm 2.0 6 Mm 8.8 Mm 6°
TABLE 3d
In the present embodiment, the radius of curvature R1 of the second reflective surface 13 is-12.87 mm, the distance W between the first reflective surface 12 and the second transmissive surface 14 on the optical axis O is 1.90 mm, and the |r1/w| is 6.77, and is in the range of 2< |r1/w| <10, so that the telephoto lens 1 can have smaller aberration while guaranteeing the light input amount, and the imaging quality of the camera module 10 is improved.
In the present embodiment, the distance L between the first reflecting surface 12 and the second reflecting surface 13 on the optical axis O is-4.71 mm, and the |w/l| is 0.40, and in the range of 0.1+|w/l|+| 0.9, the blocking effect of the light shielding surface 16 on the direct stray light can be ensured while the molding difficulty of the lens L0 is reduced, and the imaging quality of the camera module 10 is improved.
In the present embodiment, the radius of curvature R1 of the second reflecting surface 13 is-12.87 mm, the radius of curvature R2 of the first reflecting surface 12 is-4.53 mm, and |r1/r2| is 2.84, and in the range of 0.5+|r1/r2|+.10, the optical total length TTL of the telephoto lens 1 can be increased while ensuring that the telephoto lens 1 has less aberration, so as to increase the imaging effect.
In the present embodiment, the radius of curvature R3 of the second transmission surface 14 is-13.7 mm, and |r2/r3| is 0.33, in the range of 0.1+|r2/r3|+.10, the optical total length TTL of the telephoto lens 1 can be increased while ensuring that the telephoto lens 1 has less aberration, to increase the imaging effect.
In the present embodiment, the outer diameter D1 of the first transmissive surface 11 and the outer diameter D2 of the first reflective surface 12 satisfy d2/d1=0.26, and in the range of 0.2+.d2/d1+.0.7, the proportion of effective light can be increased while the light entering amount of the lens group G is ensured, and the imaging quality is improved.
In the present embodiment, the outer diameter D4 of the second transmitting surface 14 and the outer diameter D2 of the first reflecting surface 12 satisfy d4/d2=0.80, and in the range of 0.2+.d4/d2+.1, the amount of light entering can be increased while reducing direct stray light, and the imaging quality can be further improved.
In the present embodiment, the taper angle θ of the groove 15 of the lens L0 is 8 °, which satisfies: θ is more than or equal to 0 and less than or equal to 30 degrees, so that the direct stray light can be effectively blocked while the molding difficulty of the lens L0 is reduced, and the imaging quality of the tele lens 1 is improved.
In the present embodiment, the optical power of the first lens L1 is-4.0 mm. The first lens L1 has negative focal power, and can diverge light rays of the feature lens through the first lens L1 to correct aberration of the feature lens, and sign imaging quality of the camera module 10.
In the present embodiment, the second lens L2 has an optical power of 20.8 mm and has a positive optical power; the third lens L3 has an optical power of-6.6 mm and has negative optical power; the focal power of the fourth lens L4 is 15.1 millimeters, the positive focal power is provided, the second lens L2 has the positive focal power, light rays are converged, miniaturization of the lens group G is achieved, and large aperture design is facilitated. In addition, the imaging picture has more balanced image quality by the design of the focal power of the plurality of lenses.
In the present embodiment, the total optical length TTL of the telephoto lens 1 is 8.8 mm, and the effective focal length EFL of the telephoto lens 1 is 34.5 mm, so that the TTL/EFL is 0.26, and in the range of 0.2-0.6, the telephoto lens 1 has a long focal length, and has a smaller total optical length TTL while satisfying long-distance shooting, so that the height of the camera module 10 including the telephoto lens 1 is small, and the application requirements of the folder and the thinning of the electronic device 100 are satisfied.
In the embodiment, the image height ImgH of the telephoto lens 1 is 6 mm, so that the ImgH/EFL is 0.17, and in the range of 0.1-0.5, the telephoto lens 1 has a long focal length while realizing a large field angle and a large target surface, and has higher imaging quality and better long-distance shooting performance.
In the embodiment, the aperture value F of the tele lens 1 is 2.0, and is in the range of 1.0-4.4, and the aperture value F is smaller, so that the light incoming amount of the lens is large, and the tele lens is suitable for a shooting environment with weak illumination.
Referring to fig. 11 in combination, fig. 11 is a simulation effect diagram of the telephoto lens 1 shown in fig. 10.
Fig. 11 is an axial chromatic aberration chart of the telephoto lens 1. Wherein the axial chromatic aberration curve comprises spherical aberration curves corresponding to different wave bands (the illustrations comprise 650nm, 610nm, 555nm, 510nm and 470 nm) of the system; the abscissa is the deviation value along the optical axis O, and the ordinate is the normalized coordinate at the pupil, i.e. the normalized aperture. The physical meaning of the axial chromatic aberration curve graph is that the light with corresponding wavelength emitted from the 0-degree view field deviates from an ideal image point after passing through an optical system; the smaller the absolute value of the deviation value, the better the aberration correction effect of the optical system, and the higher the imaging quality of the telephoto lens 1. As can be seen from fig. 11, the deviation value is less than or equal to 0.04 mm in the range of different wave bands and full aperture bands, that is, the spherical aberration of the camera module 10 is less than or equal to 0.04 mm, which means that the on-axis aberration (chromatic aberration, etc.) of the telephoto lens 1 is better corrected.
The above embodiments are only for illustrating the technical solution of the present application, and not for limiting the same; although the application has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit of the application. Embodiments of the application and features of the embodiments may be combined with each other without conflict.

Claims (15)

1. The long-focus lens is characterized by comprising a lens and a lens group, wherein the object side surface of the lens is provided with a first transmission surface and a first reflection surface, the first reflection surface is positioned in a paraxial region, the first transmission surface is arranged around the first reflection surface, the lens is provided with a groove, an opening of the groove is positioned in the paraxial region of the image side surface of the lens, the image side surface of the lens is provided with a second reflection surface, the second reflection surface is arranged around the opening of the groove, the wall of the groove is provided with a second transmission surface, and the second transmission surface is opposite to the opening of the groove; the lens group is positioned on the image side of the lens and at least part of the lens group is positioned in the groove;
The curvature radius R1 of the second reflecting surface and the distance W between the first reflecting surface and the second transmitting surface on the optical axis satisfy the following conditions: 2< |R1/W| <10.
2. The tele lens according to claim 1, wherein a distance L between the first reflecting surface and the second reflecting surface on the optical axis and a distance W between the first reflecting surface and the second transmitting surface on the optical axis satisfy: the W/L is more than or equal to 0.1 and less than or equal to 0.9.
3. The tele lens according to claim 1 or 2, wherein the radius of curvature R1 of the second reflecting surface and the radius of curvature R2 of the first reflecting surface satisfy: R1/R2 is more than or equal to 0.5 and less than or equal to 10.
4. A telephoto lens according to any of claims 1 to 3, wherein the radius of curvature R2 of the first reflective surface and the radius of curvature R3 of the second transmissive surface satisfy: R2/R3 is more than or equal to 0.1 and less than or equal to 10.
5. The tele lens according to any one of claims 1 to 4, wherein the outer diameter D1 of the first transmissive surface and the outer diameter D2 of the first reflective surface satisfy: D2/D1 is less than or equal to 0.7, or D2/D1 is less than or equal to 0.2 and less than or equal to 0.7.
6. The tele lens according to any one of claims 1 to 5, wherein the outer diameter D4 of the second transmissive surface and the outer diameter D2 of the first reflective surface satisfy: D4/D2 is less than or equal to 1, or D4/D2 is less than or equal to 0.2 and less than or equal to 1.
7. The telephoto lens according to any of claims 1 to 6, wherein a wall of the recess is provided with a light shielding surface surrounding the second transmissive surface and connected between the second transmissive surface and an opening of the recess.
8. The tele lens of claim 7, wherein the light-shielding surface is a conical surface, and the cone angle θ of the light-shielding surface satisfies: θ is more than or equal to 0 and less than or equal to 30 degrees.
9. The tele lens of claim 7 or 8, wherein the light-blocking surface has a light transmittance of less than or equal to 10-2.
10. The tele lens of any one of claims 1 to 9, wherein the lens group comprises a first lens near the object side, the first lens having negative optical power.
11. The tele lens of claim 10, wherein the lens group comprises four lenses.
12. The tele lens of any one of claims 1 to 11, wherein the total optical length TTL of the tele lens and the effective focal length EFL of the tele lens satisfy: TTL/EFL is more than or equal to 0.2 and less than or equal to 0.6.
13. The telephoto lens according to any of claims 1 to 12, wherein the effective focal length EFL of the telephoto lens and the image height ImgH of the telephoto lens satisfy: imgH/EFL is more than or equal to 0.1 and less than or equal to 0.5.
14. A camera module comprising a photosensitive element and the tele lens of any one of claims 1 to 13, the photosensitive element being located on an image side of the tele lens.
15. An electronic device comprising an image processor and the camera module of claim 14, the image processor communicatively coupled to the camera module, the image processor configured to obtain an image signal from the camera module and process the image signal.
CN202211580791.0A 2022-12-09 2022-12-09 Long-focus lens, camera module and electronic equipment Pending CN118169834A (en)

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US4834515A (en) * 1984-11-29 1989-05-30 Lockheed Missiles & Space Company, Inc. Catadioptric imaging system with dioptric assembly of the petzval type
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