Patent Application
20210396960
The present disclosure relates to the technical field of optical imaging, and in particular to an optical system, a lens module, and an electronic device.
In recent years, with the development of manufacturing technologies for electronic devices such as smart phones and tablets and the emergence of diversified user requirements, the demand for miniaturized camera lenses in the market is gradually increasing. At present, an electronic device is usually equipped with multiple cameras with different characteristics and suitable for different application environments. As the size and thickness of electronic devices are maintained or even reduced, more stringent requirements on the miniaturization of the lenses of the electronic devices have emerged. In addition, with the advancement of semiconductor process technology, the pixel size of photosensitive elements has also been reduced, and miniaturized lenses with good imaging quality have become the mainstream of the market.
In order to provide users with a better imaging experience, imaging devices are usually equipped with large photosensitive elements. In addition, in order to achieve high imaging quality and large aperture, more lenses need to be installed in the imaging device, which makes it difficult to realize the miniaturization of the camera lens of the imaging device. Therefore, the existing lens cannot satisfy the requirements of large aperture, high resolution, and miniaturization at the same time.
The present disclosure aims to provide an optical system, a lens module, and an electronic device to solve the above technical problems.
An optical system is provided in the present disclosure. The optical system includes, in order from an object side to an image side along an optical axis: a first lens with a positive refractive power, where the first lens has an object-side surface which is convex near the optical axis and an image-side surface which is concave near the optical axis; a second lens with a negative refractive power, where the second lens has an object-side surface which is convex near the optical axis and an image-side surface which is concave near the optical axis; a third lens with a refractive power; a fourth lens with a positive refractive power; a fifth lens with a refractive power; a sixth lens with a refractive power, where the sixth lens has an object-side surface which is concave near the optical axis; and a seventh lens with a negative refractive power, where the seventh lens has an object-side surface which is convex near the optical axis and an image-side surface which is concave near the optical axis. Each of the first lens to the seventh lens has an aspherical object-side surface and an aspherical image-side surface. The optical system satisfies the following expression: TTL/Imgh<1.32, where TTL represents a distance from the object-side surface of the first lens to an imaging surface of the optical system along the optical axis, and Imgh represents half of a length of a diagonal of an effective pixel area of the imaging surface. According to the present disclosure, the first lens to the seventh lens are configured with appropriate surface profiles and refractive powers, so that the optical system can satisfy the requirements of high resolution, large aperture, and good imaging quality as well as maintain a compact structure and miniaturized. When the optical system satisfies the above expression and the imaging surface is fixed, the total length of the optical system can be small, and the miniaturization requirement for the optical system can be realized.
In some implementations, the optical system satisfies the following expression: 2<f/R14<3.5, where f represents an effective focal length of the optical system, and R14 represents a radius of curvature of the image-side surface of the seventh lens at the optical axis. When the optical system satisfies the above expression, R14 is assigned with an appropriate value, and the chief ray angle of the internal field of view of the chip can be better matched.
In some implementations, the optical system satisfies the following expression: FNO≤2, where FNO represents an F-number of the optical system. When the optical system satisfies the above expression and the effective focal length of the optical system is fixed, a large aperture can be ensured with FNO≤2, so that the amount of light entering the optical system can be large enough. Therefore, an image captured can be clearer, and the imaging quality of scenes with low brightness, such as night scenes, starry sky can be improved.
In some implementations, the optical system satisfies the following expression: TTL/f<1.35, where TTL represents the distance from the object-side surface of the first lens to the imaging surface of the optical system along the optical axis, and f represents an effective focal length of the optical system. When the optical system satisfies the above expression and the effective focal length of the optical system is fixed, the miniaturization requirement for the optical system can be satisfied.
In some implementations, the optical system satisfies the following expression: f1/f2>−0.15, where f1 represents an effective focal length of the first lens, and f2 represents an effective focal length of the second lens. When the optical system satisfies the above expression, among the effective focal length of the first lens and the effective focal length of the second lens, one is positive and the other is negative, which effectively helps to balance the chromatic aberration of the optical system. The above focal length ratio can be assigned with an appropriate value, thereby reducing the sensitivity of the optical system to a certain extent.
In some implementations, the optical system satisfies the following expression: sag1/sag2<15, where sag1 represents a saggital depth at an effective aperture of the object-side surface of the first lens, and sag2 represents a saggital depth at an effective aperture of the image-side surface of the first lens. When the optical system satisfies the above expression, the ratio of sag1/sag2 can be assigned with an appropriate value, thereby ensuring the manufacturability of the first lens, which is beneficial to manufacturing. In addition, the sensitivity of the entire optical system can be reduced.
In some implementations, the optical system satisfies the following expression: (R2+R1)/(R2−R1)<5, where R1 represents a radius of curvature of the object-side surface of the first lens, and R2 represents a radius of curvature of the image-side surface of the first lens. When the optical system satisfies the above expression, the ratio of (R2+R1)/(R2−R1) can be assigned with an appropriate value, thereby enhancing the refractive power of the first lens. The chromatic spherical aberration can be well corrected even with a large aperture, and the overall performance can be improved.
In some implementations, the optical system satisfies the following expression: f1234/f567>−0.5, where f1234 represents a combined focal length of the first lens to the fourth lens, and f567 represents a combined focal length of the fifth lens to the seventh lens. The optical system of the present disclosure can be regarded as composed of two groups of lenses. The first group of lenses includes the first lens to the fourth lens and has a positive focal length, and the second group of lenses includes the fifth lens to the seventh lens and has a negative focal length, which helps to correct the chromatic aberration of the entire optical system and improve the performance of the optical system. When the optical system satisfies the above expression, the absolute value of the focal length of the first group of lenses is smaller than the absolute value of the focal length of the second group of lenses, thereby reducing the sensitivity of the second group of lenses and improving the yield rate in the actual production process.
A lens module is provided. The lens includes a lens barrel, an electronic photosensitive element, and the above optical system. The first lens to the seventh lens of the optical system are disposed in the lens barrel, and the electronic photosensitive element is disposed on the image side of the optical system and configured to convert light passing through the first lens to the seventh lens and incident on the electronic photosensitive element into an electrical signal of an image. According to the present disclosure, the first lens to the seventh lens of the optical system are installed in the lens module and are configured with appropriate surface profiles and refractive powers. In this way, the lens module can satisfy the requirements of high resolution, large aperture, and good imaging quality as well as maintain a compact structure, and the miniaturization of the lens module can be achieved.
An electronic device is provided. The electronic device includes a housing and the above lens module received in the housing. According to the present disclosure, the above lens module is disposed in the electronic device, so that the electronic device can satisfy the requirements of high resolution, large aperture, and good imaging quality as well as maintain a compact structure, and the miniaturization of the electronic device can be achieved.
In order to more clearly describe the technical solutions in the implementations of the present disclosure or the related art, the following will briefly introduce the drawings that need to be used in the description of the implementations or the related art. Obviously, the drawings in the following description illustrate only some implementations of the present disclosure. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative work.
Technical solutions in the implementations of the present disclosure will be described clearly and completely hereinafter with reference to the accompanying drawings in the implementations of the present disclosure. Apparently, the described implementations are merely some rather than all implementations of the present disclosure. All other implementations obtained by those of ordinary skill in the art based on the implementations of the present disclosure without creative efforts shall fall within the protection scope of the present disclosure.
A lens module is provided. The lens includes a lens barrel, an electronic photosensitive element, and an optical system according to some implementations of the present disclosure. The first lens to the seventh lens of the optical system are disposed in the lens barrel, and the electronic photosensitive element is disposed on the image side of the optical system and configured to convert light passing through the first lens to the seventh lens and incident on the electronic photosensitive element into an electrical signal of an image. The electronic photosensitive element may be a complementary metal oxide semiconductor (CMOS) or a charge-coupled device (CCD). The lens module can be an independent lens of a digital camera, or an imaging module integrated on an electronic device such as a smart phone. According to the present disclosure, the first lens to the seventh lens of the optical system are installed in the lens module and are configured with appropriate surface profiles and refractive powers. In this way, the lens module can satisfy the requirements of high resolution, large aperture, and good imaging quality as well as maintain a compact structure, and the miniaturization of the lens module can be achieved.
An electronic device is provided. The electronic device includes a housing and a lens module according to some implementations of the present disclosure received in the housing. The electronic device can be a smart phone, a personal digital assistant (PDA), a tablet computer, a smart watch, a drone, an e-book reader, a driving recorder, a wearable device, or the like. According to the present disclosure, the above lens module is provided in the electronic device, so that the electronic device can satisfy the requirements of high resolution, large aperture, and good imaging quality as well as maintain a compact structure, and the miniaturization of the electronic device can be achieved.
An optical system is provided. The optical system includes, in order from an object side to an image side along an optical axis: a first lens, a second lens, a third lens, a fourth lens, a fifth lens, and a seventh lens. In the first to sixth lenses, there is an air gap between any two adjacent lenses.
The first lens has a positive refractive power and an object-side surface which is convex near the optical axis and an image-side surface which is concave near the optical axis. The second lens has a negative refractive power and an object-side surface which is convex near the optical axis and an image-side surface which is concave near the optical axis. The third lens has a refractive power. The fourth lens has a positive refractive power. The fifth lens has a refractive power. The sixth lens has a refractive power and an object-side surface which is concave near the optical axis. The seventh lens has a negative refractive power and an object-side surface which is convex near the optical axis and an image-side surface which is concave near the optical axis. Each of the first lens to the seventh lens has an aspherical object-side surface and an aspherical image-side surface. The optical system satisfies the following expression: TTL/Imgh<1.32, where TTL represents a distance from the object-side surface of the first lens to an imaging surface of the optical system along the optical axis, and Imgh represents half of a length of a diagonal of an effective pixel area of the imaging surface. According to the present disclosure, the first lens to the seventh lens are configured with appropriate surface profiles and refractive powers, so that the optical system can satisfy the requirements of high resolution, large aperture, and good imaging quality as well as maintain a compact structure and miniaturized. When the optical system satisfies the above expression and the imaging surface is fixed, the total length of the optical system can be small, and the miniaturization requirement for the optical system can be realized.
In some implementations, the optical system satisfies the following expression: 2<f/R14<3.5, where f represents an effective focal length of the optical system, and R14 represents a radius of curvature of the image-side surface of the seventh lens at the optical axis. When the optical system satisfies the above expression, R14 is assigned with an appropriate value, and the chief ray angle of the internal field of view of the chip can be better matched.
In some implementations, the optical system satisfies the following expression: FNO≤2, where FNO represents an F-number of the optical system. When the optical system satisfies the above expression and the effective focal length of the optical system is fixed, a large aperture can be ensured with FNO≤2, so that the amount of light entering the optical system can be large enough. Therefore, an image captured can be clearer, and the imaging quality of scenes with low brightness, such as night scenes, starry sky can be improved.
In some implementations, the optical system satisfies the following expression: TTL/f<1.35, where TTL represents the distance from the object-side surface of the first lens to the imaging surface of the optical system along the optical axis, and f represents an effective focal length of the optical system. When the optical system satisfies the above expression and the effective focal length of the optical system is fixed, the miniaturization requirement for the optical system can be satisfied. An upper limit of TTL can be set, for example, to 7 mm.
In some implementations, the optical system satisfies the following expression: f1/f2>−0.15, where f1 represents an effective focal length of the first lens, and f2 represents an effective focal length of the second lens. When the optical system satisfies the above expression, among the effective focal length of the first lens and the effective focal length of the second lens, one is positive and the other is negative, which effectively helps to balance the chromatic aberration of the optical system. The above focal length ratio can be assigned with an appropriate value, thereby reducing the sensitivity of the optical system to a certain extent.
In some implementations, the optical system satisfies the following expression: sag1/sag2<15, where sag1 represents a saggital depth at an effective aperture of the object-side surface of the first lens, and sag2 represents a saggital depth at an effective aperture of the image-side surface of the first lens. When the optical system satisfies the above expression, the ratio of sag1/sag2 can be assigned with an appropriate value, thereby ensuring the manufacturability of the first lens, which is beneficial to manufacturing. In addition, the sensitivity of the entire optical system can be reduced.
In some implementations, the optical system satisfies the following expression: (R2+R1)/(R2−R1)<5, where R1 represents a radius of curvature of the object-side surface of the first lens, and R2 represents a radius of curvature of the image-side surface of the first lens. When the optical system satisfies the above expression, the ratio of (R2+R1)/(R2−R1) can be assigned with an appropriate value, thereby enhancing the refractive power of the first lens. The chromatic spherical aberration can be well corrected even with a large aperture, and the overall performance can be improved.
In some implementations, the optical system satisfies the following expression: f1234/f567>−0.5, where f1234 represents a combined focal length of the first lens to the fourth lens, and f567 represents a combined focal length of the fifth lens to the seventh lens. The optical system of the present disclosure can be regarded as composed of two groups of lenses. The first group of lenses includes the first lens to the fourth lens and has a positive focal length, and the second group of lenses includes the fifth lens to the seventh lens and has a negative focal length, which helps to correct the chromatic aberration of the entire optical system and improve the performance of the optical system. When the optical system satisfies the above expression, the absolute value of the focal length of the first group of lenses is smaller than the absolute value of the focal length of the second group of lenses, thereby reducing the sensitivity of the second group of lenses and improving the yield rate in the actual production process.
Referring to
The first lens L1 has a positive refractive power. The object-side surface S1 of the first lens is convex near the optical axis, and the image-side surface S2 of the first lens is concave near the optical axis. The object-side surface S1 of the first lens is concave at the periphery, and the image-side surface S2 of the first lens is concave at the periphery. The second lens L2 has a negative refractive power. The object-side surface S3 of the second lens is convex near the optical axis, and the image-side surface S4 of the second lens is concave near the optical axis. The object-side surface S3 of the second lens is convex at the periphery, and the image-side surface S4 of the second lens is concave at the periphery. The third lens L3 has a negative refractive power. The object-side surface S5 of the third lens is convex near the optical axis, and the image-side surface S6 of the third lens is concave near the optical axis. The object-side surface S5 of the third lens is concave at the periphery, and the image-side surface S6 of the third lens is concave at the periphery. The fourth lens L4 has a positive refractive power. The object-side surface S7 of the fourth lens is convex near the optical axis, and the image-side surface S8 of the fourth lens is concave near the optical axis. The object-side surface S7 of the fourth lens is convex at the periphery, and the image-side surface S8 is a concave surface at the periphery. The fifth lens L5 has a negative refractive power. The object-side surface S9 of the fifth lens is concave near the optical axis, and the image-side surface S10 of the fifth lens is convex near the optical axis. The object-side surface S9 of the fifth lens is convex at the periphery, and the image-side surface S10 is convex at the periphery. The sixth lens L6 has a positive refractive power. The object-side surface S11 of the sixth lens is convex near the optical axis, and the image-side surface S12 of the sixth lens is concave near the optical axis. The object-side surface S11 of the sixth lens is convex at the periphery, and the image-side surface S12 is concave at the periphery. The seventh lens L7 has a negative refractive power. The object-side surface S13 of the seventh lens is convex near the optical axis, and the image-side surface S14 of the seventh lens is concave near the optical axis. The object-side surface S13 of the seventh lens is concave at the periphery, and the image-side surface S14 is convex at the periphery. The first lens L1 to the seventh lens L7 are all made of plastic.
In addition, the optical system also includes a stop (STO), an infrared filter L8, and an imaging surface S17. The stop is disposed on one side of the first lens L1 away from the second lens L2 for controlling the amount of light entering the optical system. In some implementations, the stop can also be disposed between two adjacent lenses or on other lenses. The infrared filter L8 is disposed on the image side of the seventh lens L7 and includes the object-side surface S15 and the image-side surface S16. The infrared filter L8 is used to filter out infrared light so that the light incident on the imaging surface S17 only contains visible light. The wavelength of the visible light is 380 nm-780 nm. The infrared filter L8 is made of glass and can be coated thereon. The imaging surface S17 is the surface on which an image formed after the light from an object passes through the optical system.
Table 1a shows characteristics of the optical system in this implementation. Data in Table 1a is obtained based on light of a wavelength of 587 nm. Y radius, thickness, and focal length are all in millimeters (mm).
The effective focal length of the optical system is represented as f, the F-number of the optical system is represented as FNO, the angle of view of the optical system is represented as FOV, and the distance from the object-side surface of the first lens to the imaging surface of the optical system along the optical axis is represented as TTL.
In this implementation, the object-side surface and the image-side surface of any one of the first lens L1 to the seventh lens L5 are aspherical. The surface profile x of each aspherical lens can be defined by but not limited to the following aspherical formula:
where x represents a distance (saggital depth) along the optical axis from a vertex of the aspherical surface to a position on the aspherical surface at a height h, c represents the paraxial curvature of the aspherical surface, which is the inverse of the Y radius (that is, c=1/R, where R represents the Y radius in the Table 1a), k represents the conic coefficient, Ai represents the i-th order correction coefficient of the aspherical surface. Table 1b shows higher-order coefficients A4, A6, A8, A10, A12, A14, A16, A18, and A20 of each of aspherical lens surfaces S1 to S16 in the optical system of
Referring to
The first lens L1 has a positive refractive power. The object-side surface S1 of the first lens is convex near the optical axis, and the image-side surface S2 of the first lens is concave near the optical axis. The object-side surface S1 of the first lens is concave at the periphery, and the image-side surface S2 of the first lens is convex at the periphery. The second lens L2 has a negative refractive power. The object-side surface S3 of the second lens is convex near the optical axis, and the image-side surface S4 of the second lens is concave near the optical axis. The object-side surface S3 of the second lens is convex at the periphery, and the image-side surface S4 of the second lens is convex at the periphery. The third lens L3 has a positive refractive power. The object-side surface S5 of the third lens is concave near the optical axis, and the image-side surface S6 of the third lens is convex near the optical axis. The object-side surface S5 of the third lens is concave at the periphery, and the image-side surface S6 of the third lens is concave at the periphery. The fourth lens L4 has a positive refractive power. The object-side surface S7 of the fourth lens is convex near the optical axis, and the image-side surface S8 of the fourth lens is convex near the optical axis. The object-side surface S7 of the fourth lens is convex at the periphery, and the image-side surface S8 is a concave surface at the periphery. The fifth lens L5 has a negative refractive power. The object-side surface S9 of the fifth lens is concave near the optical axis, and the image-side surface S10 of the fifth lens is convex near the optical axis. The object-side surface S9 of the fifth lens is convex at the periphery, and the image-side surface S10 is concave at the periphery. The sixth lens L6 has a positive refractive power. The object-side surface S11 of the sixth lens is convex near the optical axis, and the image-side surface S12 of the sixth lens is concave near the optical axis. The object-side surface S11 of the sixth lens is convex at the periphery, and the image-side surface S12 is concave at the periphery. The seventh lens L7 has a negative refractive power. The object-side surface S13 of the seventh lens is convex near the optical axis, and the image-side surface S14 of the seventh lens is concave near the optical axis. The object-side surface S13 of the seventh lens is concave at the periphery, and the image-side surface S14 is convex at the periphery.
The other structures of the optical system of
Table 2a shows characteristics of the optical system in this implementation. Data in Table 2a is obtained based on light of a wavelength of 587 nm. Y radius, thickness, and focal length are all in millimeters (mm).
Each parameter in Table 2a represents the same meaning as that in the optical system of
Table 2b shows higher-order coefficients that can be used for each aspherical lens surface in the optical system of
Referring to
The first lens L1 has a positive refractive power. The object-side surface S1 of the first lens is convex near the optical axis, and the image-side surface S2 of the first lens is concave near the optical axis. The object-side surface S1 of the first lens is concave at the periphery, and the image-side surface S2 of the first lens is convex at the periphery. The second lens L2 has a negative refractive power. The object-side surface S3 of the second lens is convex near the optical axis, and the image-side surface S4 of the second lens is concave near the optical axis. The object-side surface S3 of the second lens is convex at the periphery, and the image-side surface S4 of the second lens is convex at the periphery. The third lens L3 has a negative refractive power. The object-side surface S5 of the third lens is convex near the optical axis, and the image-side surface S6 of the third lens is concave near the optical axis. The object-side surface S5 of the third lens is concave at the periphery, and the image-side surface S6 of the third lens is concave at the periphery. The fourth lens L4 has a positive refractive power. The object-side surface S7 of the fourth lens is convex near the optical axis, and the image-side surface S8 of the fourth lens is concave near the optical axis. The object-side surface S7 of the fourth lens is convex at the periphery, and the image-side surface S8 is a concave surface at the periphery. The fifth lens L5 has a positive refractive power. The object-side surface S9 of the fifth lens is convex near the optical axis, and the image-side surface S10 of the fifth lens is concave near the optical axis. The object-side surface S9 of the fifth lens is convex at the periphery, and the image-side surface S10 is convex at the periphery. The sixth lens L6 has a positive refractive power. The object-side surface S11 of the sixth lens is convex near the optical axis, and the image-side surface S12 of the sixth lens is concave near the optical axis. The object-side surface S11 of the sixth lens is convex at the periphery, and the image-side surface S12 is concave at the periphery. The seventh lens L7 has a negative refractive power. The object-side surface S13 of the seventh lens is convex near the optical axis, and the image-side surface S14 of the seventh lens is concave near the optical axis. The object-side surface S13 of the seventh lens is concave at the periphery, and the image-side surface S14 is convex at the periphery.
The other structures of the optical system of
Table 3a shows characteristics of the optical system in this implementation. Data in Table 3a is obtained based on light of a wavelength of 587 nm. Y radius, thickness, and focal length are all in millimeters (mm).
Each parameter in Table 3a represents the same meaning as that in the optical system of
Table 3b shows higher-order coefficients that can be used for each aspherical lens surface in the optical system of
Referring to
The first lens L1 has a positive refractive power. The object-side surface S1 of the first lens is convex near the optical axis, and the image-side surface S2 of the first lens is concave near the optical axis. The object-side surface S1 of the first lens is concave at the periphery, and the image-side surface S2 of the first lens is convex at the periphery. The second lens L2 has a negative refractive power. The object-side surface S3 of the second lens is convex near the optical axis, and the image-side surface S4 of the second lens is concave near the optical axis. The object-side surface S3 of the second lens is convex at the periphery, and the image-side surface S4 of the second lens is convex at the periphery. The third lens L3 has a negative refractive power. The object-side surface S5 of the third lens is convex near the optical axis, and the image-side surface S6 of the third lens is concave near the optical axis. The object-side surface S5 of the third lens is concave at the periphery, and the image-side surface S6 of the third lens is concave at the periphery. The fourth lens L4 has a positive refractive power. The object-side surface S7 of the fourth lens is convex near the optical axis, and the image-side surface S8 of the fourth lens is concave near the optical axis. The object-side surface S7 of the fourth lens is convex at the periphery, and the image-side surface S8 is a concave surface at the periphery. The fifth lens L5 has a positive refractive power. The object-side surface S9 of the fifth lens is convex near the optical axis, and the image-side surface S10 of the fifth lens is concave near the optical axis. The object-side surface S9 of the fifth lens is concave at the periphery, and the image-side surface S10 is convex at the periphery. The sixth lens L6 has a negative refractive power. The object-side surface S11 of the sixth lens is concave near the optical axis, and the image-side surface S12 of the sixth lens is concave near the optical axis. The object-side surface S11 of the sixth lens is convex at the periphery, and the image-side surface S12 is concave at the periphery. The seventh lens L7 has a negative refractive power. The object-side surface S13 of the seventh lens is convex near the optical axis, and the image-side surface S14 of the seventh lens is concave near the optical axis. The object-side surface S13 of the seventh lens is concave at the periphery, and the image-side surface S14 is convex at the periphery.
The other structures of the optical system of
Table 4a shows characteristics of the optical system in this implementation. Data in Table 4a is obtained based on light of a wavelength of 587 nm. Y radius, thickness, and focal length are all in millimeters (mm).
Each parameter in Table 4a represents the same meaning as that in the optical system of
Table 4b shows higher-order coefficients that can be used for each aspherical lens surface in the optical system of
Referring to
The first lens L1 has a positive refractive power. The object-side surface S1 of the first lens is convex near the optical axis, and the image-side surface S2 of the first lens is concave near the optical axis. The object-side surface S1 of the first lens is concave at the periphery, and the image-side surface S2 of the first lens is convex at the periphery. The second lens L2 has a negative refractive power. The object-side surface S3 of the second lens is convex near the optical axis, and the image-side surface S4 of the second lens is concave near the optical axis. The object-side surface S3 of the second lens is convex at the periphery, and the image-side surface S4 of the second lens is convex at the periphery. The third lens L3 has a negative refractive power. The object-side surface S5 of the third lens is convex near the optical axis, and the image-side surface S6 of the third lens is concave near the optical axis. The object-side surface S5 of the third lens is concave at the periphery, and the image-side surface S6 of the third lens is concave at the periphery. The fourth lens L4 has a positive refractive power. The object-side surface S7 of the fourth lens is convex near the optical axis, and the image-side surface S8 of the fourth lens is convex near the optical axis. The object-side surface S7 of the fourth lens is convex at the periphery, and the image-side surface S8 is a concave surface at the periphery. The fifth lens L5 has a negative refractive power. The object-side surface S9 of the fifth lens is concave near the optical axis, and the image-side surface S10 of the fifth lens is convex near the optical axis. The object-side surface S9 of the fifth lens is convex at the periphery, and the image-side surface S10 is concave at the periphery. The sixth lens L6 has a positive refractive power. The object-side surface S11 of the sixth lens is convex near the optical axis, and the image-side surface S12 of the sixth lens is convex near the optical axis. The object-side surface S11 of the sixth lens is convex at the periphery, and the image-side surface S12 is concave at the periphery. The seventh lens L7 has a negative refractive power. The object-side surface S13 of the seventh lens is convex near the optical axis, and the image-side surface S14 of the seventh lens is concave near the optical axis. The object-side surface S13 of the seventh lens is concave at the periphery, and the image-side surface S14 is convex at the periphery.
The other structures of the optical system of
Table 5a shows characteristics of the optical system in this implementation. Data in Table 5a is obtained based on light of a wavelength of 587 nm. Y radius, thickness, and focal length are all in millimeters (mm).
Each parameter in Table 5a represents the same meaning as that in the optical system of
Table 5b shows higher-order coefficients that can be used for each aspherical lens surface in the optical system of
Referring to
The first lens L1 has a positive refractive power. The object-side surface S1 of the first lens is convex near the optical axis, and the image-side surface S2 of the first lens is concave near the optical axis. The object-side surface S1 of the first lens is concave at the periphery, and the image-side surface S2 of the first lens is concave at the periphery. The second lens L2 has a negative refractive power. The object-side surface S3 of the second lens is convex near the optical axis, and the image-side surface S4 of the second lens is concave near the optical axis. The object-side surface S3 of the second lens is convex at the periphery, and the image-side surface S4 of the second lens is convex at the periphery. The third lens L3 has a positive refractive power. The object-side surface S5 of the third lens is convex near the optical axis, and the image-side surface S6 of the third lens is concave near the optical axis. The object-side surface S5 of the third lens is concave at the periphery, and the image-side surface S6 of the third lens is concave at the periphery. The fourth lens L4 has a positive refractive power. The object-side surface S7 of the fourth lens is concave near the optical axis, and the image-side surface S8 of the fourth lens is convex near the optical axis. The object-side surface S7 of the fourth lens is convex at the periphery, and the image-side surface S8 is a concave surface at the periphery. The fifth lens L5 has a negative refractive power. The object-side surface S9 of the fifth lens is concave near the optical axis, and the image-side surface S10 of the fifth lens is convex near the optical axis. The object-side surface S9 of the fifth lens is convex at the periphery, and the image-side surface S10 is convex at the periphery. The sixth lens L6 has a positive refractive power. The object-side surface S11 of the sixth lens is convex near the optical axis, and the image-side surface S12 of the sixth lens is concave near the optical axis. The object-side surface S11 of the sixth lens is convex at the periphery, and the image-side surface S12 is concave at the periphery. The seventh lens L7 has a negative refractive power. The object-side surface S13 of the seventh lens is convex near the optical axis, and the image-side surface S14 of the seventh lens is concave near the optical axis. The object-side surface S13 of the seventh lens is concave at the periphery, and the image-side surface S14 is convex at the periphery.
The other structures of the optical system of
Table 6a shows characteristics of the optical system in this implementation. Data in Table 6a is obtained based on light of a wavelength of 587 nm. Y radius, thickness, and focal length are all in millimeters (mm).
Each parameter in Table 6a represents the same meaning as that in the optical system of
Table 6b shows higher-order coefficients that can be used for each aspherical lens surface in the optical system of
Referring to
The first lens L1 has a positive refractive power. The object-side surface S1 of the first lens is convex near the optical axis, and the image-side surface S2 of the first lens is concave near the optical axis. The object-side surface S1 of the first lens is convex at the periphery, and the image-side surface S2 of the first lens is concave at the periphery. The second lens L2 has a negative refractive power. The object-side surface S3 of the second lens is convex near the optical axis, and the image-side surface S4 of the second lens is concave near the optical axis. The object-side surface S3 of the second lens is convex at the periphery, and the image-side surface S4 of the second lens is convex at the periphery. The third lens L3 has a negative refractive power. The object-side surface S5 of the third lens is concave near the optical axis, and the image-side surface S6 of the third lens is concave near the optical axis. The object-side surface S5 of the third lens is concave at the periphery, and the image-side surface S6 of the third lens is concave at the periphery. The fourth lens L4 has a positive refractive power. The object-side surface S7 of the fourth lens is convex near the optical axis, and the image-side surface S8 of the fourth lens is concave near the optical axis. The object-side surface S7 of the fourth lens is convex at the periphery, and the image-side surface S8 is a concave surface at the periphery. The fifth lens L5 has a negative refractive power. The object-side surface S9 of the fifth lens is concave near the optical axis, and the image-side surface S10 of the fifth lens is concave near the optical axis. The object-side surface S9 of the fifth lens is concave at the periphery, and the image-side surface S10 is convex at the periphery. The sixth lens L6 has a positive refractive power. The object-side surface S11 of the sixth lens is convex near the optical axis, and the image-side surface S12 of the sixth lens is concave near the optical axis. The object-side surface S11 of the sixth lens is convex at the periphery, and the image-side surface S12 is concave at the periphery. The seventh lens L7 has a negative refractive power. The object-side surface S13 of the seventh lens is convex near the optical axis, and the image-side surface S14 of the seventh lens is concave near the optical axis. The object-side surface S13 of the seventh lens is concave at the periphery, and the image-side surface S14 is convex at the periphery.
The other structures of the optical system of
Table 7a shows characteristics of the optical system in this implementation. Data in Table 7a is obtained based on light of a wavelength of 587 nm. Y radius, thickness, and focal length are all in millimeters (mm).
Each parameter in Table 7a represents the same meaning as that in the optical system of
Table 7b shows higher-order coefficients that can be used for each aspherical lens surface in the optical system of
Table 8 shows values of TTL/Imgh, f/R14, FNO, TTL/f, f1/f2, sag1/sag2, (R2+R1)/(R2−R1), f1234/f567 of the optical systems of
It can be seen from table 8 that each optical systems according to each implementation satisfies the following expressions: TTL/Imgh<1.32, 2<f/R14<3.5, FNO≤2, TTL/f<1.35, f1/f2>−0.15, sag1/sag2<15, (R2+R1)/(R2−R1)<5, f1234/f567>−0.5.
The technical features of the implementations of the present disclosure can be combined. For brief description, not all possible combinations of the various technical features in the implementations of the present disclosure are described herein. However, as long as there is no conflict in the combination of these technical features, such combination should be considered within the scope of the present disclosure.
Only some implementations of the present disclosure are described in detail herein, which should not be understood as a limitation on the scope of the present disclosure. It should be noted that, for those of ordinary skill in the art, without departing from the concept of the present disclosure, modifications and improvements can be made and should be considered within the scope of the present disclosure. Therefore, the scope of the present disclosure should be subject to the appended claims.
The present application is a continuation of International Application No. PCT/CN2020/088513, filed on Apr. 30, 2020, the disclosure of which is hereby incorporated by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/CN2020/088513 | Apr 2020 | US |
| Child | 17462798 | US |
