An autofocus optical lens with a fish-eye large field of view and a large relative aperture

Abstract

The present invention discloses a fish-eye large field of view and large relative aperture autofocus optical lens, which is composed of a negative refractive power transmission group G1, a positive refractive power transmission group G2, an aperture stop, a negative refractive power transmission group G3, a positive refractive power transmission group G4, and an image plane in sequence from the object side to the image side; the transmission group G1 is composed of a first negative lens, a second negative lens, a first positive lens, and a third negative lens; the transmission group G2 is composed of a second positive lens; the transmission group G3 is composed of a third positive lens, a fourth negative lens, a fourth positive lens, and a fifth negative lens; the transmission group G4 is composed of a fifth positive lens and a sixth positive lens; its working wavelength is in the visible light band, the object-side working distance is 0.2 m to infinity, the field of view is 150 degrees, and the relative aperture is 1 / 1.6. The fish-eye large field of view and large relative aperture autofocus optical lens has the advantages of a large field of view, a large relative aperture, fast focusing, and good imaging quality.

Description

Technical Field

[0001] The present invention belongs to the technical field of optical lenses, and particularly relates to a fish-eye large field of view and large relative aperture autofocus optical lens. Background Art

[0002] In recent years, the demand for mirrorless cameras in the photography market has been expanding rapidly. Along with the continuous update and development of the mature high-precision CMOS process device technology, mirrorless cameras also have good high-quality imaging quality. Therefore, the customer group using them is also increasing continuously, and various different requirements for various shooting scenarios have also emerged. There are still gaps in the focal length range of the original factory supporting lenses. Especially for the autofocus optical lens with a fish-eye large field of view and large relative aperture, not only the price is high, resulting in low acceptance by consumers, but also its shooting distance and focusing stroke are relatively long, resulting in a slow focusing time. Therefore, it is necessary to design a fish-eye lens with rapid focusing and a wide shooting distance range. Summary of the Invention

[0003] In order to overcome the above-mentioned deficiencies, a fish-eye large field of view and large relative aperture autofocus optical lens is proposed. Its working wavelength is in the visible light band, the object-side working distance is 0.2m - infinity, the field of view is 150 degrees, and the relative aperture is 1 / 1.6. The fish-eye large field of view and large relative aperture autofocus optical lens has the advantages of a large field of view, a large relative aperture, rapid focusing, and good imaging quality.

[0004] The technical solution adopted by the present invention to achieve the above purpose is: to provide a fish-eye large field of view and large relative aperture autofocus optical lens, which is composed of a transmission group G1, a transmission group G2, a transmission group G3, a transmission group G4, and an image plane in sequence from the object side to the image side;

[0005] The transmission group G1 has a negative optical power, the transmission group G2 has a positive optical power, the transmission group G3 has a negative optical power, and the transmission group G4 has a positive optical power;

[0006] The transmission group G1 is composed of 4 lenses. The transmission group G1 includes a first negative lens made of flint glass, a second negative lens made of crown glass, a first positive lens made of flint glass, and a third negative lens made of crown glass;

[0007] The transmission group G2 is composed of 1 lens. The transmission group G2 includes a second positive lens made of optical plastic;

[0008] The transmission group G3 is composed of 4 lenses. The transmission group G3 includes a third positive lens made of crown glass, a fourth negative lens made of flint glass, a fourth positive lens made of flint glass, and a fifth negative lens made of crown glass;

[0009] The transmission group G4 consists of two lenses, including a fifth positive lens made of crown glass and a sixth positive lens made of crown glass;

[0010] The aperture stop is located between the transmission group G2 and the transmission group G3.

[0011] For a fish-eye large field of view and large relative aperture autofocus optical lens according to the present invention, a further preferred technical solution is that the ratio range of the focal length of the transmission group G1 to the focal length of the entire optical system when the object distance is infinity is (-2.96, -2.18);

[0012] The ratio range of the focal length of the transmission group G2 to the focal length of the entire optical system when the object distance is infinity is (2.47, 3.88);

[0013] The ratio range of the focal length of the transmission group G3 to the focal length of the entire optical system when the object distance is infinity is (-9.26, -8.11);

[0014] The ratio range of the focal length of the transmission group G4 to the focal length of the entire optical system when the object distance is infinity is (2.68, 4.08);

[0015] For a fish-eye large field of view and large relative aperture autofocus optical lens according to the present invention, a further preferred technical solution is that the transmission group G2 is a moving component, and the transmission groups G1, G3, and G4 are fixed components.

[0016] For a fish-eye large field of view and large relative aperture autofocus optical lens according to the present invention, a further preferred technical solution is that the second positive lens is an aspherical lens, and the first positive lens, the third to sixth positive lenses, and the first to fifth negative lenses are all spherical lenses.

[0017] For a fish-eye large field of view and large relative aperture autofocus optical lens according to the present invention, a further preferred technical solution is that in the transmission group G1, the first positive lens and the third negative lens form a doublet lens, the first negative lens and the second negative lens are single lenses, and the transmission group G2 consists of a group of single lenses; in the transmission group G3, the third positive lens and the fourth negative lens form a doublet lens, and the fourth positive lens and the fifth negative lens form a doublet lens; the transmission group G2 consists of two groups of single lenses.

[0018] Compared with the prior art, the technical solution of the present invention has the following advantages / beneficial effects:

[0019] 1. The working wavelength of the fish-eye large field of view and large relative aperture autofocus optical lens of the present invention is 430 - 656 nm, the telephoto distance is infinity, the close-up distance is 0.2 m, the field of view is 150 degrees, and the relative aperture is 1 / 1.6, having advantages such as a large field of view and a large relative aperture.

[0020] 2. The fish-eye large field of view and large relative aperture autofocus optical lens of the present invention is composed of an object plane, a transmission group G1, a transmission group G2, a transmission group G3, and a transmission group G4. Except for the second positive lens, all other lenses are spherical surfaces, with low manufacturing costs, which can significantly reduce its selling price, making it easily acceptable to consumers and having good sales prospects.

[0021] 3. The fish-eye large field of view and large relative aperture autofocus optical lens of the present invention has good imaging characteristics, and the entire system has good transfer functions and image points.

[0022] 4. When the object distance of the fish-eye large field of view and large relative aperture autofocus optical lens of the present invention changes from infinity to the close-up distance, the focusing stroke is short, only 0.12 mm, having the advantage of fast focusing. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the embodiments. It should be understood that the following drawings only show some embodiments of the present invention, and thus should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can also be obtained based on these drawings without creative efforts.

[0024] Figure 1 It is a schematic structural diagram of the fish-eye large field of view and large relative aperture autofocus optical lens of the present invention.

[0025] Figure 2 It is the modulation transfer function curve of the fish-eye large field of view and large relative aperture autofocus optical lens of the present invention at infinity.

[0026] Figure 3 It is the modulation transfer function curve of the fish-eye large field of view and large relative aperture autofocus optical lens of the present invention at the close-up distance.

[0027] Figure 4 It is the fan diagram of the fish-eye large field of view and large relative aperture autofocus optical lens of the present invention at infinity.

[0028] Figure 5 It is the fan diagram of the fish-eye large field of view and large relative aperture autofocus optical lens of the present invention at the close-up distance.

[0029] Figure 6 It is the spot diagram of the fish-eye large field of view and large relative aperture autofocus optical lens of the present invention at infinity.

[0030] Figure 7 It is the spot diagram of the fish-eye large field of view and large relative aperture autofocus optical lens of the present invention at the close-up distance.

[0031] Figure 8This is the relative illumination curve of the fish-eye large field of view and large relative aperture autofocus optical lens of the present invention.

[0032] The markings in the figure are respectively: 1. First negative lens, 2. Second negative lens, 3. First positive lens, 4. Third negative lens, 5. Second positive lens, 6. Third positive lens, 7. Fourth negative lens, 8. Fourth positive lens, 9. Fifth negative lens, 10. Fifth positive lens, 11. Sixth positive lens, 12. Image plane. Detailed implementation manners

[0033] To make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention. Therefore, the detailed description of the embodiments of the present invention provided below is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention.

[0034] It should be noted that: similar reference numerals and letters denote similar items in the following drawings. Therefore, once an item is defined in one drawing, it may not be further defined and explained in subsequent drawings.

[0035] Embodiment:

[0036] Figure 1 This is a schematic layout diagram of the fish-eye large field of view and large relative aperture autofocus optical lens of the present invention. From the object side to the image side in sequence, 11 optical elements form transmission groups G1, G2, G3, and G4.

[0037] The ratio range of the focal length of transmission group G1 to the focal length of the entire optical system when the object distance is infinite is (-2.96, -2.18);

[0038] The ratio range of the focal length of transmission group G2 to the focal length of the entire optical system when the object distance is infinite is (2.47, 3.88);

[0039] The ratio range of the focal length of transmission group G3 to the focal length of the entire optical system when the object distance is infinite is (-9.26, -8.11);

[0040] The ratio range of the focal length of transmission group G4 to the focal length of the entire optical system when the object distance is infinite is (2.68, 4.08).

[0041] The transmissive group G1 is a transmissive group with a negative focal power. The transmissive group G1 includes a first negative lens 1 made of flint glass, a second negative lens 2 made of crown glass, a first positive lens 3 made of flint glass, and a third negative lens 4 made of crown glass. The light entering the transmissive group G1 is diverged by the transmissive group G1 and then enters the transmissive group G2.

[0042] The transmissive group G2 is a transmissive group with a positive focal power. The transmissive group G2 includes a second positive lens 5 made of optical plastic. The light emerging from the transmissive group G1 is converged by the transmissive group G2 and then enters the transmissive group G3.

[0043] The transmissive group G3 is a transmissive group with a negative focal power. The transmissive group G3 includes a third positive lens 6 made of crown glass, a fourth negative lens 7 made of flint glass, a fourth positive lens 8 made of crown glass, and a fifth negative lens 9 made of flint glass. The light emerging from the transmissive group G2 is diverged by the transmissive group G3 and then enters the transmissive group G4.

[0044] The transmissive group G4 is a transmissive group with a positive focal power. The transmissive group G4 includes a fifth positive lens 10 made of crown glass and a sixth positive lens 11 made of crown glass. The light emerging from the transmissive group G3 is converged by the transmissive group G4 and then reaches the image plane.

[0045] And the aperture stop is located between the transmissive group G2 and the transmissive group G3. The transmissive group G2 is a moving component, and the transmissive groups G1, G3, and G4 are fixed components. The change of the focal length is adjusted by the movement of the transmissive group G2.

[0046] The second positive lens is an aspherical lens, and the first positive lens, the third to sixth positive lenses, and the first to fifth negative lenses are all spherical lenses. That is, among the overall 11 lenses, only the second positive lens is an aspherical lens, and the rest are spherical lenses. The manufacturing cost is low, the selling price can be significantly reduced, it is easy for consumers to accept, and the sales prospect is good.

[0047] In the transmissive group G1, the first positive lens and the third negative lens form a doublet lens, the first negative lens and the second negative lens are singlet lenses, and the transmissive group G2 consists of a set of singlet lenses; in the transmissive group G3, the third positive lens and the fourth negative lens form a doublet lens, and the fourth positive lens and the fifth negative lens form a doublet lens; the transmissive group G2 consists of two sets of singlet lenses.

[0048] The physical parameters of each lens in this embodiment meet the data requirements shown in Table 1:

[0049] Table 1 Physical parameters of each lens in this embodiment

[0050]

[0051] The equation of the aspherical surface is as follows:

[0052]

[0053] Regarding the definition of the aspherical shape, the aspherical shape is defined as follows:

[0054] y: The radial coordinate starting from the optical axis.

[0055] z: The offset in the optical axis direction starting from the intersection point of the aspherical surface and the optical axis.

[0056] r: The radius of curvature of the reference spherical surface of the aspherical surface.

[0057] k is the conic constant.

[0058] A4, A6, A8, A10, A12,... are the aspherical coefficients of the 4th, 6th, 8th, 10th, 12th,... orders.

[0059] Surfaces 8 and 9 of lens 5 are aspherical surfaces. In Table 2, the 4th, 6th, 8th, 10th, and 12th order aspherical coefficients A4, A6, A8, A10 of the aspherical surface and the conic constant k are shown together.

[0060] Table 2 Aspherical parameters of this embodiment

[0061]

[0062] This embodiment is achieved through the following technical measures: The working wavelength of the optical lens is 430 - 656 nm, the telephoto distance is infinity, the close-focus distance is 0.2 m, the field of view is 150 degrees, and the relative aperture is 1 / 1.6. Light rays are emitted from the object surface and imaged onto the image surface after passing through transmission group G1, transmission group G2, transmission group G3, and transmission group G4. The present invention has the advantages of a large field of view, a large relative aperture, rapid focusing, and good imaging quality.

[0063] Figure 2 、 Figure 3 The modulation transfer function curves of the fish-eye large field of view and large relative aperture autofocus optical lens designed in this embodiment at infinity and close-focus distance are given. In the figure, the vertical coordinate OTF coefficient is the fast Fourier transform modulation transfer function, and the horizontal coordinate is the spatial frequency: line pairs per millimeter. It can be seen that the contrast of the fish-eye large field of view and large relative aperture autofocus optical lens at infinity and close-focus distance is relatively high, reaching 120 lp / mm.

[0064] Figure 4 、 Figure 5The Ray Fan diagrams of the fish-eye large field of view and large relative aperture autofocus optical lens designed in this embodiment at infinity and close shooting distances are given. In the figure, ex: x-component of ray aberration, ey: y-component of ray aberration, px: x entrance pupil coordinate, py: y entrance pupil coordinate. It can be seen that the aberrations of the fish-eye large field of view and large relative aperture autofocus optical lens at infinity and close shooting distances are both small.

[0065] Figure 6 、 Figure 7 The Spot Diagram of the fish-eye large field of view and large relative aperture autofocus optical lens designed in this embodiment at infinity and close shooting distances is given. The unit of the legend in the figure is μm. It can be seen that the image point spots of the fish-eye large field of view and large relative aperture autofocus optical lens at infinity and close shooting distances are small and have good consistency.

[0066] Figure 8 The relative illumination curve of the fish-eye large field of view and large relative aperture autofocus optical lens designed in this embodiment is given. It can be seen that the relative illuminations of the fish-eye large field of view and large relative aperture autofocus optical lens are all better than 0.9.

[0067] In the description of the present invention, it should be understood that the orientation or positional relationships indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. are based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0068] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed", etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral body; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0069] The above are only the preferred embodiments of the present invention. It should be noted that the above preferred embodiments should not be regarded as a limitation to the present invention, and the protection scope of the present invention should be subject to the scope defined by the claims. For those of ordinary skill in the art in this technical field, without departing from the spirit and scope of the present invention, several improvements and retouches can also be made, and these improvements and retouches should also be regarded as the protection scope of the present invention.

Claims

1. A fisheye large field of view large relative aperture autofocus optical lens, characterized in that: It is composed of transmission group G1, transmission group G2, transmission group G3, transmission group G4 and image plane from the object side to the image side in sequence; The transmission group G1 has a negative optical power, the transmission group G2 has a positive optical power, the transmission group G3 has a negative optical power, and the transmission group G4 has a positive optical power; The transmission group G1 is composed of 4 lenses, including a first negative lens made of flint glass, a second negative lens made of crown glass, a first positive lens made of flint glass, and a third negative lens made of crown glass; The transmission group G2 is composed of one lens, and the transmission group G2 includes a second positive lens made of optical plastic; The transmission group G3 is composed of 4 lenses, including a third positive lens made of crown glass, a fourth negative lens made of flint glass, a fourth positive lens made of flint glass, and a fifth negative lens made of crown glass; The transmission group G4 is composed of two lenses, including a fifth positive lens made of crown glass and a sixth positive lens made of crown glass; A first negative lens, a second negative lens, a first positive lens, a third negative lens, a second positive lens, a third positive lens, a fourth negative lens, a fourth positive lens, a fifth negative lens, a fifth positive lens and a sixth positive lens are arranged in sequence from the object side to the image side along the optical axis; The aperture stop is located between the transmission group G2 and the transmission group G3.

2. The fisheye large-field-of-view large-relative-aperture autofocus optical lens according to claim 1, characterized in that: The ratio of the focal length of the transmission group G1 to the focal length of the entire optical system when the object distance is infinite is in the range of (-2.96, -2.18); The ratio of the focal length of the transmission group G2 to the focal length of the entire optical system when the object distance is infinite is in the range of (2.47, 3.88); The ratio range of the focal length of the transmission group G3 and the focal length of the entire optical system when the object distance is infinite is (-9.26, -8.11); The ratio range of the focal length of the transmission group G4 to the focal length of the entire optical system when the object distance is infinite is (2.68, 4.08).

3. The fisheye large-field-of-view large-relative-aperture autofocus optical lens according to claim 1, characterized in that: The transmission group G2 is a moving component, and the transmission groups G1, G3 and G4 are fixed components.

4. The fisheye large-field-of-view large-relative-aperture autofocus optical lens according to claim 1, characterized in that: The second positive lens is an aspherical lens, and the first positive lens, the third to sixth positive lenses, and the first to fifth negative lenses are spherical lenses.

5. The fisheye large-field-of-view large-relative-aperture autofocus optical lens according to claim 1, characterized in that: In the transmission group G1, the first positive lens and the third negative lens form a doublet lens, and the first negative lens and the second negative lens are single lenses; the transmission group G2 consists of a single lens; in the transmission group G3, the third positive lens and the fourth negative lens form a doublet lens, and the fourth positive lens and the fifth negative lens form a doublet lens; the transmission group G4 consists of two single lenses.

Images